Defect Detection in Fuel Cell Gas Diffusion Electrodes Using Infrared Thermography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ulsh, Michael; Porter, Jason M.; Bittinat, Daniel C.

2016-04-01

Polymer electrolyte membrane fuel cells are energy conversion devices that offer high power densities and high efficiencies for mobile and other applications. Successful introduction into the marketplace requires addressing cost barriers such as production volumes and platinum loading. For cost reduction, it is vital to minimize waste and maximize quality during the manufacturing of platinum-containing electrodes, including gas diffusion electrodes (GDEs). In this work, we report on developing a quality control diagnostic for GDEs, involving creating an ex situ exothermic reaction on the electrode surface and using infrared thermography to measure the resulting temperature profile. Experiments with a moving GDEmore » containing created defects were conducted to demonstrate the applicability of the diagnostic for real-time web-line inspection.« less

Reducing electrocoagulation harvesting costs for practical microalgal biodiesel production.

PubMed

Dassey, Adam J; Theegala, Chandra S

2014-01-01

Electrocoagulation has shown potential to be a primary microalgae harvesting technique for biodiesel production. However, methods to reduce energy and electrode costs are still necessary for practical application. Electrocoagulation tests were conducted on Nannochloris sp. and Dunaliella sp. using perforated aluminium and iron electrodes under various charge densities. Aluminium electrodes were shown to be more efficient than iron electrodes when harvesting both algal species. Despite the lower harvesting efficiency, however, the iron electrodes were more energy and cost efficient. Operational costs of less than $0.03/L oil were achieved when harvesting Nannochloris sp. with iron electrodes at 35% harvest efficiency, whereas aluminium electrodes cost $0.75/L oil with 42% harvesting efficiency. Increasing the harvesting efficiencies for both aluminium and iron electrodes also increased the overall cost per litre of oil, therefore lower harvesting efficiencies with lower energy inputs was recommended. Also, increasing the culturing salinity to 2 ppt sodium chloride for freshwater Nannochloris sp. was determined practical to improve the electrocoagulation energy efficiency despite a 25% reduction in cell growth.

Innovative manufacturing and materials for low cost lithium ion batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, Steven

2015-12-29

This project demonstrated entirely new manufacturing process options for lithium ion batteries with major potential for improved cost and performance. These new manufacturing approaches are based on the use of the new electrode-coated separators instead of the conventional electrode-coated metal current collector foils. The key enabler to making these electrode-coated separators is a new and unique all-ceramic separator with no conventional porous plastic separator present. A simple, low cost, and high speed manufacturing process of a single coating of a ceramic pigment and polymer binder onto a re-usable release film, followed by a subsequent delamination of the all-ceramic separator andmore » any layers coated over it, such as electrodes and metal current collectors, was utilized. A suitable all-ceramic separator was developed that demonstrated the following required features needed for making electrode-coated separators: (1) no pores greater than 100 nanometer (nm) in diameter to prevent any penetration of the electrode pigments into the separator; (2) no shrinkage of the separator when heated to the high oven heats needed for drying of the electrode layer; and (3) no significant compression of the separator layer by the high pressure calendering step needed to densify the electrodes by about 30%. In addition, this nanoporous all-ceramic separator can be very thin at 8 microns thick for increased energy density, while providing all of the performance features provided by the current ceramic-coated plastic separators used in vehicle batteries: improved safety, longer cycle life, and stability to operate at voltages up to 5.0 V in order to obtain even more energy density. The thin all-ceramic separator provides a cost savings of at least 50% for the separator component and by itself meets the overall goal of this project to reduce the cell inactive component cost by at least 20%. The all-ceramic separator also enables further cost savings by its excellent heat stability with no shrinkage at up to 220oC. This allows vacuum drying of the dry cell just before filling with the electrolyte and thereby can reduce the size of the cell assembly dry room by 50%. Once the electrode-coated separator is produced, there are many different approaches for adding the metal current collector layers and making and connecting the tabs of the cells. These approaches include: (1) laminating the electrode side of the electrode-coated separator to both sides of a metal current collector; and (2) making a full coated electrode stack by coating or depositing a current collector layer on the electrode side and then coating a second electrode layer onto the current collector. Further cost savings are available from using lower cost and/or thinner and lighter current collectors and from using a separator coating manufacturing process at widths of 1.5 meters (m) or more and at high production line speeds of up to 125 meters per minute (mpm), both of which are well above the conventional coating widths and line speeds presently used in manufacturing electrodes for lithium ion batteries.« less

Vertically aligned single-walled carbon nanotubes as low-cost and high electrocatalytic counter electrode for dye-sensitized solar cells.

PubMed

Dong, Pei; Pint, Cary L; Hainey, Mel; Mirri, Francesca; Zhan, Yongjie; Zhang, Jing; Pasquali, Matteo; Hauge, Robert H; Verduzco, Rafael; Jiang, Mian; Lin, Hong; Lou, Jun

2011-08-01

A novel dye-sensitized solar cell (DSSC) structure using vertically aligned single-walled carbon nanotubes (VASWCNTs) as the counter electrode has been developed. In this design, the VASWCNTs serve as a stable high surface area and highly active electrocatalytic counter-electrode that could be a promising alternative to the conventional Pt analogue. Utilizing a scalable dry transfer approach to form a VASWCNTs conductive electrode, the DSSCs with various lengths of VASWCNTs were studied. VASWCNTs-DSSC with 34 μm original length was found to be the optimal choice in the present study. The highest conversion efficiencies of VASWCNTs-DSSC achieved 5.5%, which rivals that of the reference Pt DSSC. From the electrochemical impedance spectroscopy analysis, it shows that the new DSSC offers lower interface resistance between the electrolyte and the counter electrode. This reproducible work emphasizes the promise of VASWCNTs as efficient and stable counter electrode materials in DSSC device design, especially taking into account the low-cost merit of this promising material.

Spraying Techniques for Large Scale Manufacturing of PEM-FC Electrodes

NASA Astrophysics Data System (ADS)

Hoffman, Casey J.

Fuel cells are highly efficient energy conversion devices that represent one part of the solution to the world's current energy crisis in the midst of global climate change. When supplied with the necessary reactant gasses, fuel cells produce only electricity, heat, and water. The fuel used, namely hydrogen, is available from many sources including natural gas and the electrolysis of water. If the electricity for electrolysis is generated by renewable energy (e.g., solar and wind power), fuel cells represent a completely 'green' method of producing electricity. The thought of being able to produce electricity to power homes, vehicles, and other portable or stationary equipment with essentially zero environmentally harmful emissions has been driving academic and industrial fuel cell research and development with the goal of successfully commercializing this technology. Unfortunately, fuel cells cannot achieve any appreciable market penetration at their current costs. The author's hypothesis is that: the development of automated, non-contact deposition methods for electrode manufacturing will improve performance and process flexibility, thereby helping to accelerate the commercialization of PEMFC technology. The overarching motivation for this research was to lower the cost of manufacturing fuel cell electrodes and bring the technology one step closer to commercial viability. The author has proven this hypothesis through a detailed study of two non-contact spraying methods. These scalable deposition systems were incorporated into an automated electrode manufacturing system that was designed and built by the author for this research. The electrode manufacturing techniques developed by the author have been shown to produce electrodes that outperform a common lab-scale contact method that was studied as a baseline, as well as several commercially available electrodes. In addition, these scalable, large scale electrode manufacturing processes developed by the author are also flexible and can be used to fabricate almost any fuel cell electrodes on the market today. This dissertation provides a description of the entire electrode manufacturing process as well as an analysis of the accuracy, performance and repeatability of the methods.

Efficient charge injection in p-type polymer field-effect transistors with low-cost molybdenum electrodes through V2O5 interlayer.

PubMed

Baeg, Kang-Jun; Bae, Gwang-Tae; Noh, Yong-Young

2013-06-26

Here we report high-performance polymer OFETs with a low-cost Mo source/drain electrode by efficient charge injection through the formation of a thermally deposited V2O5 thin film interlayer. A thermally deposited V2O5 interlayer is formed between a regioregular poly(3-hexylthiophene) (rr-P3HT) or a p-type polymer semiconductor containing dodecyl-substituted thienylenevinylene (TV) and dodecylthiophene (PC12TV12T) and the Mo source/drain electrode. The P3HT or PC12TV12T OFETs with the bare Mo electrode exhibited lower charge carrier mobility than those with Au owing to a large barrier height for hole injection (0.5-1.0 eV). By forming the V2O5 layer, the P3HT or PC12TV12T OFETs with V2O5 on the Mo electrode exhibited charge carrier mobility comparable to that of a pristine Au electrode. Best P3HT or PC12TV12T OFETs with 5 nm thick V2O5 on Mo electrode show the charge carrier mobility of 0.12 and 0.38 cm(2)/(V s), respectively. Ultraviolet photoelectron spectroscopy results exhibited the work-function of the Mo electrode progressively changed from 4.3 to 4.9 eV with an increase in V2O5 thickness from 0 to 5 nm, respectively. Interestingly, the V2O5-deposited Mo exhibits comparable Rc to Au, which mainly results from the decreased barrier height for hole carrier injection from the low-cost metal electrode to the frontier molecular orbital of the p-type polymer semiconductor after the incorporation of the transition metal oxide hole injection layer, such as V2O5. This enables the development of large-area, low-cost electronics with the Mo electrodes and V2O5 interlayer.

Process optimization via response surface methodology in the treatment of metal working industry wastewater with electrocoagulation.

PubMed

Guvenc, Senem Yazici; Okut, Yusuf; Ozak, Mert; Haktanir, Birsu; Bilgili, Mehmet Sinan

2017-02-01

In this study, process parameters in chemical oxygen demand (COD) and turbidity removal from metal working industry (MWI) wastewater were optimized by electrocoagulation (EC) using aluminum, iron and steel electrodes. The effects of process variables on COD and turbidity were investigated by developing a mathematical model using central composite design method, which is one of the response surface methodologies. Variance analysis was conducted to identify the interaction between process variables and model responses and the optimum conditions for the COD and turbidity removal. Second-order regression models were developed via the Statgraphics Centurion XVI.I software program to predict COD and turbidity removal efficiencies. Under the optimum conditions, removal efficiencies obtained from aluminum electrodes were found to be 76.72% for COD and 99.97% for turbidity, while the removal efficiencies obtained from iron electrodes were found to be 76.55% for COD and 99.9% for turbidity and the removal efficiencies obtained from steel electrodes were found to be 65.75% for COD and 99.25% for turbidity. Operational costs at optimum conditions were found to be 4.83, 1.91 and 2.91 €/m 3 for aluminum, iron and steel electrodes, respectively. Iron electrode was found to be more suitable for MWI wastewater treatment in terms of operational cost and treatment efficiency.

Technical and economic analysis of solvent-based lithium-ion electrode drying with water and NMP

DOE PAGES

Wood, David L.; Quass, Jeffrey D.; Li, Jianlin; ...

2017-05-16

Processing lithium-ion battery (LIB) electrode dispersions with water as the solvent during primary drying offers many advantages over N-methylpyrrolidone (NMP). An in-depth analysis of the comparative drying costs of LIB electrodes is discussed for both NMP- and water-based dispersion processing in terms of battery pack $/kWh. Electrode coating manufacturing and capital equipment cost savings are compared for water vs. conventional NMP organic solvent processing. A major finding of this work is that the total electrode manufacturing costs, whether water- or NMP-based, contribute about 8–9% of the total pack cost. However, it was found that up to a 2 × reductionmore » in electrode processing (drying and solvent recovery) cost can be expected along with a $3–6 M savings in associated plant capital equipment (for a plant producing 100,000 10-kWh Plug-in Hybrid Electric Vehicle (PHEV) batteries) using water as the electrode solvent. This paper shows a different perspective in that the most important benefits of aqueous electrode processing actually revolve around capital equipment savings and environmental stewardship and not processing cost savings.« less

Metal-free supercapacitor with aqueous electrolyte and low-cost carbon materials

NASA Astrophysics Data System (ADS)

Blomquist, Nicklas; Wells, Thomas; Andres, Britta; Bäckström, Joakim; Forsberg, Sven; Olin, Håkan

2017-01-01

Electric double-layer capacitors (EDLCs) or supercapacitors (SCs) are fast energy storage devices with high pulse efficiency and superior cyclability, which makes them useful in various applications including electronics, vehicles and grids. Aqueous SCs are considered to be more environmentally friendly than those based on organic electrolytes. Because of the corrosive nature of the aqueous environment, however, expensive electrochemically stable materials are needed for the current collectors and electrodes in aqueous SCs. This results in high costs for a given energy-storage capacity. To address this, we developed a novel low-cost aqueous SC using graphite foil as the current collector and a mix of graphene, nanographite, simple water-purification carbons and nanocellulose as electrodes. The electrodes were coated directly onto the graphite foil by using casting frames and the SCs were assembled in a pouch cell design. With this approach, we achieved a material cost reduction of greater than 90% while maintaining approximately one-half of the specific capacitance of a commercial unit, thus demonstrating that the proposed SC can be an environmentally friendly, low-cost alternative to conventional SCs.

ElectroCat: DOE's approach to PGM-free catalyst and electrode R&D

DOE PAGES

Thompson, Simon T.; Wilson, Adria R.; Zelenay, Piotr; ...

2018-02-03

The successful development of high-performance, durable platinum group metal-free (PGM-free) electrocatalysts and electrodes for polymer electrolyte membrane fuel cells (PEMFCs) will ultimately improve the cost-competiveness of fuel cells in a wide range of applications. This is considered to be a critical development especially for automotive fuel cell applications in order to bring the system cost of an automotive fuel cell system down to the $30/kW cost target set by the U.S. Department of Energy (DOE). The platinum group metal (PGM) electrocatalysts are a major contributor to the system cost. Addressing the technical challenges to PGM-free electrocatalyst and electrode development, therefore,more » represents one of DOE's most pressing research and development (R&D) priorities. ElectroCat was formed by the DOE as part of the Energy Materials Network (EMN) in early 2016, and shares with other EMN consortia the goal of decreasing the time to market for advanced materials related to clean energy technologies, in the context of increasing U.S. fuel cell electric vehicle (FCEV) manufacturing competitiveness. To accomplish this, the consortium performs core research and development and provides universities and companies streamlined access to the unique, world-class set of tools and expertise relevant to early-stage applied PGM-free catalyst R&D of the member national laboratories. Moreover, ElectroCat fosters a systematic methodology by which prospective catalysts and electrodes are prepared and analyzed rapidly and comprehensively using high-throughput, combinatorial methods. Catalyst discovery is augmented by theory as well as foundational electrocatalysis and materials knowledge at the participating national laboratories. Furthermore, ElectroCat has developed a data sharing framework, requisite of all EMN consortia, for disseminating its findings to the public via a searchable database, to further expedite incorporation of PGM-free electrocatalysts into next-generation fuel cells by advancing the general understanding of the PGM-free electrocatalyst field.« less

ElectroCat: DOE's approach to PGM-free catalyst and electrode R&D

DOE Office of Scientific and Technical Information (OSTI.GOV)

Thompson, Simon T.; Wilson, Adria R.; Zelenay, Piotr

The successful development of high-performance, durable platinum group metal-free (PGM-free) electrocatalysts and electrodes for polymer electrolyte membrane fuel cells (PEMFCs) will ultimately improve the cost-competiveness of fuel cells in a wide range of applications. This is considered to be a critical development especially for automotive fuel cell applications in order to bring the system cost of an automotive fuel cell system down to the $30/kW cost target set by the U.S. Department of Energy (DOE). The platinum group metal (PGM) electrocatalysts are a major contributor to the system cost. Addressing the technical challenges to PGM-free electrocatalyst and electrode development, therefore,more » represents one of DOE's most pressing research and development (R&D) priorities. ElectroCat was formed by the DOE as part of the Energy Materials Network (EMN) in early 2016, and shares with other EMN consortia the goal of decreasing the time to market for advanced materials related to clean energy technologies, in the context of increasing U.S. fuel cell electric vehicle (FCEV) manufacturing competitiveness. To accomplish this, the consortium performs core research and development and provides universities and companies streamlined access to the unique, world-class set of tools and expertise relevant to early-stage applied PGM-free catalyst R&D of the member national laboratories. Moreover, ElectroCat fosters a systematic methodology by which prospective catalysts and electrodes are prepared and analyzed rapidly and comprehensively using high-throughput, combinatorial methods. Catalyst discovery is augmented by theory as well as foundational electrocatalysis and materials knowledge at the participating national laboratories. Furthermore, ElectroCat has developed a data sharing framework, requisite of all EMN consortia, for disseminating its findings to the public via a searchable database, to further expedite incorporation of PGM-free electrocatalysts into next-generation fuel cells by advancing the general understanding of the PGM-free electrocatalyst field.« less

Understanding Fundamentals and Reaction Mechanisms of Electrode Materials for Na-Ion Batteries.

PubMed

Yu, Linghui; Wang, Luyuan Paul; Liao, Hanbin; Wang, Jingxian; Feng, Zhenxing; Lev, Ovadia; Loo, Joachim S C; Sougrati, Moulay Tahar; Xu, Zhichuan J

2018-04-01

Development of efficient, affordable, and sustainable energy storage technologies has become an area of interest due to the worsening environmental issues and rising technological dependence on Li-ion batteries. Na-ion batteries (NIBs) have been receiving intensive research efforts during the last few years. Owing to their potentially low cost and relatively high energy density, NIBs are promising energy storage devices, especially for stationary applications. A fundamental understanding of electrode properties during electrochemical reactions is important for the development of low cost, high-energy density, and long shelf life NIBs. This Review aims to summarize and discuss reaction mechanisms of the major types of NIB electrode materials reported. By appreciating how the material works and the fundamental flaws it possesses, it is hoped that this Review will assist readers in coming up with innovative solutions for designing better materials for NIBs. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preparation and properties of low-cost graphene counter electrodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Wu, Qishuang; Shen, Yue; Wang, Qiandi; Gu, Feng; Cao, Meng; Wang, Linjun

2013-12-01

With the advantages of excellent electrical properties, high catalytic activity and low-cost preparation, Graphene is one of the most expected carbon materials to replace the expensive Pt as counter electrodes for dye-sensitized solar cells (DSSCs). In this paper, graphene counter electrodes were obtained by simple doctor-blade coating method on fluorine tin oxides (FTOs). The samples were investigated by X-ray diffraction (XRD), Raman spectroscopy and scanning electron microscope (SEM). Then the low-cost graphene electrodes were applied in typical sandwich-type DSSCs with TiO2 or ZnO as photoanodes, and their photoelectric conversion efficiency (η) were about 4.34% and 2.28%, respectively, which were a little lower than those of Pt electrodes but much higher than those of graphite electrodes. This law was consistent with the test results of electrochemical impedance spectroscopy (EIS). Low-cost graphene electrodes can be applied in DSSCs by process optimization.

Counter electrodes in dye-sensitized solar cells.

PubMed

Wu, Jihuai; Lan, Zhang; Lin, Jianming; Huang, Miaoliang; Huang, Yunfang; Fan, Leqing; Luo, Genggeng; Lin, Yu; Xie, Yimin; Wei, Yuelin

2017-10-02

Dye-sensitized solar cells (DSSCs) are regarded as prospective solar cells for the next generation of photovoltaic technologies and have become research hotspots in the PV field. The counter electrode, as a crucial component of DSSCs, collects electrons from the external circuit and catalyzes the redox reduction in the electrolyte, which has a significant influence on the photovoltaic performance, long-term stability and cost of the devices. Solar cells, dye-sensitized solar cells, as well as the structure, principle, preparation and characterization of counter electrodes are mentioned in the introduction section. The next six sections discuss the counter electrodes based on transparency and flexibility, metals and alloys, carbon materials, conductive polymers, transition metal compounds, and hybrids, respectively. The special features and performance, advantages and disadvantages, preparation, characterization, mechanisms, important events and development histories of various counter electrodes are presented. In the eighth section, the development of counter electrodes is summarized with an outlook. This article panoramically reviews the counter electrodes in DSSCs, which is of great significance for enhancing the development levels of DSSCs and other photoelectrochemical devices.

Soft and wrinkled carbon membranes derived from petals for flexible supercapacitors

PubMed Central

Yu, Xiuxiu; Wang, Ying; Li, Li; Li, Hongbian; Shang, Yuanyuan

2017-01-01

Biomass materials are promising precursors for the production of carbonaceous materials due to their abundance, low cost and renewability. Here, a freestanding wrinkled carbon membrane (WCM) electrode material for flexible supercapacitors (SCs) was obtained from flower petal. The carbon membrane was fabricated by a simple thermal pyrolysis process and further activated by heating the sample in air. As a binder and current collector-free electrode, the activated wrinkled carbon membrane (AWCM) exhibited a high specific capacitance of 332.7 F/g and excellent cycling performance with 92.3% capacitance retention over 10000 cycles. Moreover, a flexible all-solid supercapacitor with AWCM electrode was fabricated and showed a maximum specific capacitance of 154 F/g and great bending stability. The development of this flower petal based carbon membrane provides a promising cost-effective and environmental benign electrode material for flexible energy storage. PMID:28361914

Ni-MH battery electrodes made by a dry powder process

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ye, Z.; Sakai, T.; Noreus, D.

1995-12-01

A dry powder roller pressing process, once developed for making both of the electrodes in low cost Ni-Cd consumer batteries, has been utilized to make electrodes for Ni-MH batteries. The process was evaluated by manually making a series of sub-C type cells that were characterized with respect to specific capacity, cycle life, and self-discharge. The performance was comparable in several respects with that of cells made by more complex Ni-foam technologies.

High Speed, Low Cost Fabrication of Gas Diffusion Electrodes for Membrane Electrode Assemblies

DOE Office of Scientific and Technical Information (OSTI.GOV)

DeCastro, Emory S.; Tsou, Yu-Min; Liu, Zhenyu

Fabrication of membrane electrode assemblies (MEAs) depends on creating inks or pastes of catalyst and binder, and applying this suspension to either the membrane (catalyst coated membrane) or gas diffusion media (gas diffusion electrode) and respectively laminating either gas diffusion media or gas diffusion electrodes (GDEs) to the membrane. One barrier to cost effective fabrication for either of these approaches is the development of stable and consistent suspensions. This program investigated the fundamental forces that destabilize the suspensions and developed innovative approaches to create new, highly stable formulations. These more concentrated formulations needed fewer application passes, could be coated overmore » longer and wider substrates, and resulted in significantly lower coating defects. In March of 2012 BASF Fuel Cell released a new high temperature product based on these advances, whereby our customers received higher performing, more uniform MEAs resulting in higher stack build yields. Furthermore, these new materials resulted in an “instant” increase in capacity due to higher product yields and material throughput. Although not part of the original scope of this program, these new formulations have also led us to materials that demonstrate equivalent performance with 30% less precious metal in the anode. This program has achieved two key milestones in DOE’s Manufacturing R&D program: demonstration of processes for direct coating of electrodes and continuous in-line measurement for component fabrication.« less

All solution-processed micro-structured flexible electrodes for low-cost light-emitting pressure sensors fabrication.

PubMed

Shimotsu, Rie; Takumi, Takahiro; Vohra, Varun

2017-07-31

Recent studies have demonstrated the advantage of developing pressure-sensitive devices with light-emitting properties for direct visualization of pressure distribution, potential application to next generation touch panels and human-machine interfaces. To ensure that this technology is available to everyone, its production cost should be kept as low as possible. Here, simple device concepts, namely, pressure sensitive flexible hybrid electrodes and OLED architecture, are used to produce low-cost resistive or light-emitting pressure sensors. Additionally, integrating solution-processed self-assembled micro-structures into the flexible hybrid electrodes composed of an elastomer and conductive materials results in enhanced device performances either in terms of pressure or spatial distribution sensitivity. For instance, based on the pressure applied, the measured values for the resistances of pressure sensors range from a few MΩ down to 500 Ω. On the other hand, unlike their evaporated equivalents, the combination of solution-processed flexible electrodes with an inverted OLED architectures display bright green emission when a pressure over 200 kPa is applied. At a bias of 3 V, their luminance can be tuned by applying a higher pressure of 500 kPa. Consequently, features such as fingernails and fingertips can be clearly distinguished from one another in these long-lasting low-cost devices.

Enhancing capacitive deionization technology as an effective method for water treatment using commercially available graphene.

PubMed

Dursun, Derya; Ozkul, Selin; Yuksel, Recep; Unalan, Husnu Emrah

2017-02-01

In recent years, capacitive deionization (CDI) has been reported as one of the emerging technologies developed with the purpose of water desalination. This work is aimed at the integration of supercapacitor electrodes for efficient removal of ions from water, and thus to achieve an energy efficient, and cost-effective water treatment process. Our objective is to transfer the vast knowledge of supercapacitors and advanced materials in area of water treatment to enhance the knowledge of the CDI process. Towards the main purpose, graphene-based supercapacitor electrodes were developed from commercially available, cost-effective graphene and the use of these new materials for deionization was explored in detail. The porosity, morphology and electrochemical characteristics of the active materials were confirmed by Brunauer-Emmett-Teller method, scanning electron microscopy, Raman spectroscopy and chronoamperometry. Furthermore, the deionization performances of the graphene electrodes were evaluated by a laboratory scale CDI unit. The ion sorption behavior of the electrode was analyzed at different electrical potentials and flow rates. Impact of operating parameters on the sorption capacity was determined. At 20 mL/min flow rate and 2.0 V potential, the electrosorptive capacity of commercially available graphene electrodes could reach 12.5 μmol/g. Our results indicated the ability to use commercially available graphene for deionization purpose.

Gold leaf: From gilding to the fabrication of disposable, wearable and low-cost electrodes.

PubMed

Santos, Mauro Sérgio Ferreira; Ameku, Wilson Akira; Gutz, Ivano Gebhardt Rolf; Paixão, Thiago Regis Longo Cesar

2018-03-01

Gold is among the most used materials in electrocatalysis. Despite this, this noble metal is still too expensive to be used in the fabrication of low cost and disposable devices. In the present work, gold-leaf sheets, usually employed in decorative crafts and wedding candies, is introduced as an inexpensive source of gold. Planar-disc and nanoband gold electrodes were simply and easily manufactured by combining gold leaf and polyimide tape. The planar disc electrode exhibited electrochemical behavior similar to that of a commercial gold electrode in 0.2molL -1 H 2 SO 4 ; cyclic voltammetry of a 1mmolL -1 solution of potassium ferricyanide (K 3 [Fe(CN) 6 ]) in 0.2molL -1 KNO 3 , using this novel electrode, displayed an 80mV difference between the oxidation and reduction peak potentials. The electrode also delivers promising prospects for the development of wearable devices. When submitted to severe mechanical deformation, this electrode exhibited neither loss of electrical contact nor significant variation in electrode response, even after fifteen bending and/or folding cycles. The thickness of the gold-leaf sheet facilitates the production of nanoband electrodes with behavior similar to that of ultramicroelectrodes. The electrode surface is easily renewed by cutting a thin slice off its end with a razor blade; this process led to limiting currents that were reproducible, presenting a relative standard deviation (RSD) of 3.8% (n = 5). Copyright © 2017 Elsevier B.V. All rights reserved.

A thermally regenerative ammonia battery with carbon-silver electrodes for converting low-grade waste heat to electricity

NASA Astrophysics Data System (ADS)

Rahimi, Mohammad; Kim, Taeyoung; Gorski, Christopher A.; Logan, Bruce E.

2018-01-01

Thermally regenerative ammonia batteries (TRABs) have shown great promise as a method to convert low-grade waste heat into electrical power, with power densities an order of magnitude higher than other approaches. However, previous TRABs based on copper electrodes suffered from unbalanced anode dissolution and cathode deposition rates during discharging cycles, limiting practical applications. To produce a TRAB with stable and reversible electrode reactions over many cycles, inert carbon electrodes were used with silver salts. In continuous flow tests, power production was stable over 100 discharging cycles, demonstrating excellent reversibility. Power densities were 23 W m-2-electrode area in batch tests, which was 64% higher than that produced in parallel tests using copper electrodes, and 30 W m-2 (net energy density of 490 Wh m-3-anolyte) in continuous flow tests. While this battery requires the use a precious metal, an initial economic analysis of the system showed that the cost of the materials relative to energy production was 220 per MWh, which is competitive with energy production from other non-fossil fuel sources. A substantial reduction in costs could be obtained by developing less expensive anion exchange membranes.

RuO2 pH Sensor with Super-Glue-Inspired Reference Electrode

PubMed Central

Wajrak, Magdalena; Alameh, Kamal

2017-01-01

A pH-sensitive RuO2 electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO2 working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO2 pH-sensitive working electrode and a SiO2-PVB junction-modified RuO2 reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices. PMID:28878182

RuO₂ pH Sensor with Super-Glue-Inspired Reference Electrode.

PubMed

Lonsdale, Wade; Wajrak, Magdalena; Alameh, Kamal

2017-09-06

A pH-sensitive RuO₂ electrode coated in a commercial cyanoacrylate adhesive typically exhibits very low pH sensitivity, and could be paired with a RuO₂ working electrode as a differential type pH sensor. However, such sensors display poor performance in real sample matrices. A pH sensor employing a RuO₂ pH-sensitive working electrode and a SiO₂-PVB junction-modified RuO₂ reference electrode is developed as an alternative high-performance solution. This sensor exhibits a performance similar to that of a commercial glass pH sensor in some common sample matrices, particularly, an excellent pH sensitivity of 55.7 mV/pH, a hysteresis as low as 2.7 mV, and a drift below 2.2 mV/h. The developed sensor structure opens the way towards the development of a simple, cost effective, and robust pH sensor for pH analysis in various sample matrices.

Hysteroscopic Endometrial Polypectomy: Clinical and Economic Data in Decision Making.

PubMed

Franchini, Mario; Lippi, Giuseppe; Calzolari, Stefano; Giarrè, Giovanna; Gubbini, Giampietro; Catena, Ursula; Di Spiezio Sardo, Attilio; Florio, Pasquale

To compare the costs of hysteroscopic polypectomy using mechanical and electrosurgical systems in the hospital operating room and an office-based setting. Retrospective cohort study (Canadian Task Force classification II-2). Tertiary referral hospital and center for gynecologic care. Seven hundred and fifty-four women who underwent endometrial polypectomy between January 20, 2015, and April 27, 2016. Hysteroscopic endometrial polypectomy performed in the same-day hospital setting or office setting using one of the following: bipolar electrode, loop electrode, mechanical device, or hysteroscopic tissue removal system. The various costs associated with the 2 clinical settings at Palagi Hospital, Florence, Italy were compiled, and a direct cost comparison was made using an activity-based cost-management system. The costs for using reusable loop electrode resection-16 or loop electrode resection-26 were significantly less expensive than using disposable loop electrode resection-27, the tissue removal system, or bipolar electrode resection (p = .0002). Total hospital costs for polypectomy with all systems were significantly less expensive in an office setting compared with same-day surgery in the hospital setting (p = .0001). Office-based hysteroscopic tissue removal was associated with shorter operative time compared with the other procedures (p = .0002) CONCLUSION: The total cost of hysteroscopic polypectomy is markedly higher when using disposable equipment compared with reusable equipment, both in the hospital operating room and the office setting. Same-day hospital or office-based surgery with reusable loop electrode resection is the most cost-effective approach in each settings, but requires experienced surgeons. Finally, the shorter surgical time should be taken into consideration for patients undergoing vaginal polypectomy in the office setting, owing more to patient comfort than to cost savings. Copyright © 2017 American Association of Gynecologic Laparoscopists. Published by Elsevier Inc. All rights reserved.

A review of laser electrode processing for development and manufacturing of lithium-ion batteries

NASA Astrophysics Data System (ADS)

Pfleging, Wilhelm

2018-02-01

Laser processes for cutting, annealing, structuring, and printing of battery materials have a great potential in order to minimize the fabrication costs and to increase the electrochemical performance and operational lifetime of lithium-ion cells. Hereby, a broad range of applications can be covered such as micro-batteries, mobile applications, electric vehicles, and stand-alone electric energy storage devices. Cost-efficient nanosecond (ns)-laser cutting of electrodes was one of the first laser technologies which were successfully transferred to industrial high-energy battery production. A defined thermal impact can be useful in electrode manufacturing which was demonstrated by laser annealing of thin-film electrodes for adjusting of battery active crystalline phases or by laser-based drying of composite thick-film electrodes for high-energy batteries. Ultrafast or ns-laser direct structuring or printing of electrode materials is a rather new technical approach in order to realize three-dimensional (3D) electrode architectures. Three-dimensional electrode configurations lead to a better electrochemical performance in comparison to conventional 2D one, due to an increased active surface area, reduced mechanical tensions during electrochemical cycling, and an overall reduced cell impedance. Furthermore, it was shown that for thick-film composite electrodes an increase of electrolyte wetting could be achieved by introducing 3D micro-/nano-structures. Laser structuring can turn electrodes into superwicking. This has a positive impact regarding an increased battery lifetime and a reliable battery production. Finally, laser processes can be up-scaled in order to transfer the 3D battery concept to high-energy and high-power lithium-ion cells.

Preparation and Application of Electrodes in Capacitive Deionization (CDI): a State-of-Art Review.

PubMed

Jia, Baoping; Zhang, Wei

2016-12-01

As a promising desalination technology, capacitive deionization (CDI) have shown practicality and cost-effectiveness in brackish water treatment. Developing more efficient electrode materials is the key to improving salt removal performance. This work reviewed current progress on electrode fabrication in application of CDI. Fundamental principal (e.g. EDL theory and adsorption isotherms) and process factors (e.g. pore distribution, potential, salt type and concentration) of CDI performance were presented first. It was then followed by in-depth discussion and comparison on properties and fabrication technique of different electrodes, including carbon aerogel, activated carbon, carbon nanotubes, graphene and ordered mesoporous carbon. Finally, polyaniline as conductive polymer and its potential application as CDI electrode-enhancing materials were also discussed.

A novel method of fabricating carbon nanotubes-polydimethylsiloxane composite electrodes for electrocardiography.

PubMed

Liu, Benyan; Chen, Yingmin; Luo, Zhangyuan; Zhang, Wenzan; Tu, Quan; Jin, Xun

2015-01-01

Polymer-based flexible electrodes are receiving much attention in medical applications due to their good wearing comfort. The current fabrication methods of such electrodes are not widely applied. In this study, polydimethylsiloxane (PDMS) and conductive additives of carbon nanotubes (CNTs) were employed to fabricate composite electrodes for electrocardiography (ECG). A three-step dispersion process consisting of ultrasonication, stirring, and in situ polymerization was developed to yield homogenous CNTs-PDMS mixtures. The CNTs-PDMS mixtures were used to fabricate CNTs-PDMS composite electrodes by replica technology. The influence of ultrasonication time and CNT concentration on polymer electrode performance was evaluated by impedance and ECG measurements. The signal amplitude of the electrodes prepared using an ultrasonication time of 12 h and CNT content of 5 wt% was comparable to that of commercial Ag/AgCl electrodes. The polymer electrodes were easily fabricated by conventional manufacturing techniques, indicating a potential advantage of reduced cost for mass production.

Prospects for reducing the processing cost of lithium ion batteries

DOE PAGES

Wood III, David L.; Li, Jianlin; Daniel, Claus

2014-11-06

A detailed processing cost breakdown is given for lithium-ion battery (LIB) electrodes, which focuses on: elimination of toxic, costly N-methylpyrrolidone (NMP) dispersion chemistry; doubling the thicknesses of the anode and cathode to raise energy density; and, reduction of the anode electrolyte wetting and SEI-layer formation time. These processing cost reduction technologies generically adaptable to any anode or cathode cell chemistry and are being implemented at ORNL. This paper shows step by step how these cost savings can be realized in existing or new LIB manufacturing plants using a baseline case of thin (power) electrodes produced with NMP processing and amore » standard 10-14-day wetting and formation process. In particular, it is shown that aqueous electrode processing can cut the electrode processing cost and energy consumption by an order of magnitude. Doubling the thickness of the electrodes allows for using half of the inactive current collectors and separators, contributing even further to the processing cost savings. Finally wetting and SEI-layer formation cost savings are discussed in the context of a protocol with significantly reduced time. These three benefits collectively offer the possibility of reducing LIB pack cost from $502.8 kWh-1-usable to $370.3 kWh-1-usable, a savings of $132.5/kWh (or 26.4%).« less

Inkjet printing of nanoporous gold electrode arrays on cellulose membranes for high-sensitive paper-like electrochemical oxygen sensors using ionic liquid electrolytes.

PubMed

Hu, Chengguo; Bai, Xiaoyun; Wang, Yingkai; Jin, Wei; Zhang, Xuan; Hu, Shengshui

2012-04-17

A simple approach to the mass production of nanoporous gold electrode arrays on cellulose membranes for electrochemical sensing of oxygen using ionic liquid (IL) electrolytes was established. The approach, combining the inkjet printing of gold nanoparticle (GNP) patterns with the self-catalytic growth of these patterns into conducting layers, can fabricate hundreds of self-designed gold arrays on cellulose membranes within several hours using an inexpensive inkjet printer. The resulting paper-based gold electrode arrays (PGEAs) had several unique properties as thin-film sensor platforms, including good conductivity, excellent flexibility, high integration, and low cost. The porous nature of PGEAs also allowed the addition of electrolytes from the back cellulose membrane side and controllably produced large three-phase electrolyte/electrode/gas interfaces at the front electrode side. A novel paper-based solid-state electrochemical oxygen (O(2)) sensor was therefore developed using an IL electrolyte, 1-butyl-3-methylimidazolium hexafluorophosphate (BMIMPF(6)). The sensor looked like a piece of paper but possessed high sensitivity for O(2) in a linear range from 0.054 to 0.177 v/v %, along with a low detection limit of 0.0075% and a short response time of less than 10 s, foreseeing its promising applications in developing cost-effective and environment-friendly paper-based electrochemical gas sensors.

Nanostructured manganese oxide thin films as electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Xia, Hui; Lai, Man On; Lu, Li

2011-01-01

Electrochemical capacitors, also called supercapacitors, are alternative energy storage devices, particularly for applications requiring high power densities. Recently, manganese oxides have been extensively evaluated as electrode materials for supercapacitors due to their low cost, environmental benignity, and promising supercapacitive performance. In order to maximize the utilization of manganese oxides as the electrode material for the supercapacitors and improve their supercapacitive performance, the nanostructured manganese oxides have therefore been developed. This paper reviews the synthesis of the nanostructured manganese oxide thin films by different methods and the supercapacitive performance of different nanostructures.

Development of an All-Metal Thick Film Cost Effective Metallization System for Solar Cells

NASA Technical Reports Server (NTRS)

Ross, B.

1980-01-01

Materials including copper powders, silver-fluoride, and silicon wafers were procured and copper pastes were prepared. Electrodes made with copper pastes were analyzed and compared with the raw materials. A needle-like structure was observed on the electroded solar cells, and was identified as eutectic copper-silicon by electron probe X-ray spectroscopy. The existence of this phase was thought to benefit electrical and metallurgical properties of the contact. Subsequently electrodes made from new material were also shown to contain this phase while simultaneously having poor adhesion.

Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

DOEpatents

Kuo, L.J.H.; Singh, P.; Ruka, R.J.; Vasilow, T.R.; Bratton, R.J.

1997-11-11

A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators. 4 figs.

Low cost stable air electrode material for high temperature solid oxide electrolyte electrochemical cells

DOEpatents

Kuo, Lewis J. H.; Singh, Prabhakar; Ruka, Roswell J.; Vasilow, Theodore R.; Bratton, Raymond J.

1997-01-01

A low cost, lanthanide-substituted, dimensionally and thermally stable, gas permeable, electrically conductive, porous ceramic air electrode composition of lanthanide-substituted doped lanthanum manganite is provided which is used as the cathode in high temperature, solid oxide electrolyte fuel cells and generators. The air electrode composition of this invention has a much lower fabrication cost as a result of using a lower cost lanthanide mixture, either a natural mixture or an unfinished lanthanide concentrate obtained from a natural mixture subjected to incomplete purification, as the raw material in place of part or all of the higher cost individual lanthanum. The mixed lanthanide primarily contains a mixture of at least La, Ce, Pr, and Nd, or at least La, Ce, Pr, Nd and Sm in its lanthanide content, but can also include minor amounts of other lanthanides and trace impurities. The use of lanthanides in place of some or all of the lanthanum also increases the dimensional stability of the air electrode. This low cost air electrode can be fabricated as a cathode for use in high temperature, solid oxide fuel cells and generators.

High-performance flexible electrode based on electrodeposition of polypyrrole/MnO2 on carbon cloth for supercapacitors

NASA Astrophysics Data System (ADS)

Fan, Xingye; Wang, Xiaolei; Li, Ge; Yu, Aiping; Chen, Zhongwei

2016-09-01

A highly flexible electrodes based on electrodeposited MnO2 and polypyrrole composite on carbon cloth is designed and developed by a facile in-situ electrodeposition technique. Such flexible composite electrodes with multiply layered structure possess a high specific capacitance of 325 F g-1 at a current density of 0.2 A g-1, and an excellent rate capability with a capacitance retention of 70% at a high current density of 5.0 A g-1. The superior electrochemical performance is mainly due to the unique electrode with improved ion- and electron-transportation pathways as well as the efficient utilization of active materials and electrode robustness. The excellent electrochemical performance and the low cost property endow this flexible nanocomposite electrode with great promise in applications of flexible supercapacitors.

A multi-pad electrode based functional electrical stimulation system for restoration of grasp

PubMed Central

2012-01-01

Background Functional electrical stimulation (FES) applied via transcutaneous electrodes is a common rehabilitation technique for assisting grasp in patients with central nervous system lesions. To improve the stimulation effectiveness of conventional FES, we introduce multi-pad electrodes and a new stimulation paradigm. Methods The new FES system comprises an electrode composed of small pads that can be activated individually. This electrode allows the targeting of motoneurons that activate synergistic muscles and produce a functional movement. The new stimulation paradigm allows asynchronous activation of motoneurons and provides controlled spatial distribution of the electrical charge that is delivered to the motoneurons. We developed an automated technique for the determination of the preferred electrode based on a cost function that considers the required movement of the fingers and the stabilization of the wrist joint. The data used within the cost function come from a sensorized garment that is easy to implement and does not require calibration. The design of the system also includes the possibility for fine-tuning and adaptation with a manually controllable interface. Results The device was tested on three stroke patients. The results show that the multi-pad electrodes provide the desired level of selectivity and can be used for generating a functional grasp. The results also show that the procedure, when performed on a specific user, results in the preferred electrode configuration characteristics for that patient. The findings from this study are of importance for the application of transcutaneous stimulation in the clinical and home environments. PMID:23009589

Symmetric Electrodes for Electrochemical Energy-Storage Devices.

PubMed

Zhang, Lei; Dou, Shi Xue; Liu, Hua Kun; Huang, Yunhui; Hu, Xianluo

2016-12-01

Increasing environmental problems and energy challenges have so far attracted urgent demand for developing green and efficient energy-storage systems. Among various energy-storage technologies, sodium-ion batteries (SIBs), electrochemical capacitors (ECs) and especially the already commercialized lithium-ion batteries (LIBs) are playing very important roles in the portable electronic devices or the next-generation electric vehicles. Therefore, the research for finding new electrode materials with reduced cost, improved safety, and high-energy density in these energy storage systems has been an important way to satisfy the ever-growing demands. Symmetric electrodes have recently become a research focus because they employ the same active materials as both the cathode and anode in the same energy-storage system, leading to the reduced manufacturing cost and simplified fabrication process. Most importantly, this feature also endows the symmetric energy-storage system with improved safety, longer lifetime, and ability of charging in both directions. In this Progress Report, we provide the comprehensive summary and comment on different symmetric electrodes and focus on the research about the applications of symmetric electrodes in different energy-storage systems, such as the above mentioned SIBs, ECs and LIBs. Further considerations on the possibility of mass production have also been presented.

A single camera photogrammetry system for multi-angle fast localization of EEG electrodes.

PubMed

Qian, Shuo; Sheng, Yang

2011-11-01

Photogrammetry has become an effective method for the determination of electroencephalography (EEG) electrode positions in three dimensions (3D). Capturing multi-angle images of the electrodes on the head is a fundamental objective in the design of photogrammetry system for EEG localization. Methods in previous studies are all based on the use of either a rotating camera or multiple cameras, which are time-consuming or not cost-effective. This study aims to present a novel photogrammetry system that can realize simultaneous acquisition of multi-angle head images in a single camera position. Aligning two planar mirrors with the angle of 51.4°, seven views of the head with 25 electrodes are captured simultaneously by the digital camera placed in front of them. A complete set of algorithms for electrode recognition, matching, and 3D reconstruction is developed. It is found that the elapsed time of the whole localization procedure is about 3 min, and camera calibration computation takes about 1 min, after the measurement of calibration points. The positioning accuracy with the maximum error of 1.19 mm is acceptable. Experimental results demonstrate that the proposed system provides a fast and cost-effective method for the EEG positioning.

Three-dimensional paper-based electrochemiluminescence immunodevice for multiplexed measurement of biomarkers and point-of-care testing.

PubMed

Ge, Lei; Yan, Jixian; Song, Xianrang; Yan, Mei; Ge, Shenguang; Yu, Jinghua

2012-02-01

In this work, electrochemiluminescence (ECL) immunoassay was introduced into the recently proposed microfluidic paper-based analytical device (μPADs) based on directly screen-printed electrodes on paper for the very first time. The screen-printed paper-electrodes will be more important for further development of this paper-based ECL device in simple, low-cost and disposable application than commercialized ones. To further perform high-performance, high-throughput, simple and inexpensive ECL immunoassay on μPAD for point-of-care testing, a wax-patterned three-dimensional (3D) paper-based ECL device was demonstrated for the very first time. In this 3D paper-based ECL device, eight carbon working electrodes including their conductive pads were screen-printed on a piece of square paper and shared the same Ag/AgCl reference and carbon counter electrodes on another piece of square paper after stacking. Using typical tris-(bipyridine)-ruthenium (Ⅱ) - tri-n-propylamine ECL system, the application test of this 3D paper-based ECL device was performed through the diagnosis of four tumor markers in real clinical serum samples. With the aid of a facile device-holder and a section-switch assembled on the analyzer, eight working electrodes were sequentially placed into the circuit to trigger the ECL reaction in the sweeping range from 0.5 to 1.1 V at room temperature. In addition, this 3D paper-based ECL device can be easily integrated and combined with the recently emerging paper electronics to further develop simple, sensitive, low-cost, disposable and portable μPAD for point-of-care testing, public health and environmental monitoring in remote regions, developing or developed countries. Copyright © 2011 Elsevier Ltd. All rights reserved.

Development of an all-metal thick film cost effective metallization system for solar cells

NASA Technical Reports Server (NTRS)

Ross, B.; Parker, J.

1982-01-01

Electrodes made with pastes produced under the previous contract were analyzed and compared with raw materials. A needle-like structure observed on the electroded solar cell was identified as eutectic copper-silicon, a phase considered to benefit the electrical and metallurgical properties of the contact. Electrodes made from copper fluorocarbon and copper silver fluoride also contained this phase but had poor adhesion. A liquid medium, intended to provide transport during carbon fluoride decomposition was incorporated into the paste resulting in better adhesion. The product survived preliminary environmental tests. A 2 cm by 2 cm solar cell made with fluorocarbon activated copper electrodes and gave 7% AMI efficiency (without AR coating). Both silver fluoride and fluorocarbon screened paste electrodes can be produced for approximately $0.04 per watt.

Direct writing electrodes using a ball pen for paper-based point-of-care testing.

PubMed

Li, Zedong; Li, Fei; Hu, Jie; Wee, Wei Hong; Han, Yu Long; Pingguan-Murphy, Belinda; Lu, Tian Jian; Xu, Feng

2015-08-21

The integration of paper with an electrochemical device has attracted growing attention for point-of-care testing, where it is of great importance to fabricate electrodes on paper in a low-cost, easy and versatile way. In this work, we report a simple strategy for directly writing electrodes on paper using a pressure-assisted ball pen to form a paper-based electrochemical device (PED). This method is demonstrated to be capable of fabricating electrodes on paper with good electrical conductivity and electrochemical performance, holding great potential to be employed in point-of-care applications, such as in human health diagnostics and food safety detection. As examples, the PEDs fabricated using the developed method are applied for detection of glucose in artificial urine and melamine in sample solutions. Furthermore, our developed strategy is also extended to fabricate PEDs with multi-electrode arrays and write electrodes on non-planar surfaces (e.g., paper cup, human skin), indicating the potential application of our method in other fields, such as fabricating biosensors, paper electronics etc.

Rubber-based carbon electrode materials derived from dumped tires for efficient sodium-ion storage.

PubMed

Wu, Zhen-Yue; Ma, Chao; Bai, Yu-Lin; Liu, Yu-Si; Wang, Shi-Feng; Wei, Xiao; Wang, Kai-Xue; Chen, Jie-Sheng

2018-04-03

The development of sustainable and low cost electrode materials for sodium-ion batteries has attracted considerable attention. In this work, a carbon composite material decorated with in situ generated ZnS nanoparticles has been prepared via a simple pyrolysis of the rubber powder from dumped tires. Upon being used as an anode material for sodium-ion batteries, the carbon composite shows a high reversible capacity and rate capability. A capacity as high as 267 mA h g-1 is still retained after 100 cycles at a current density of 50 mA g-1. The well dispersed ZnS nanoparticles in carbon significantly enhance the electrochemical performance. The carbon composites derived from the rubber powder are proposed as promising electrode materials for low-cost, large-scale energy storage devices. This work provides a new and effective method for the reuse of dumped tires, contributing to the recycling of valuable waste resources.

Microbial fuel cells: recent developments in design and materials

NASA Astrophysics Data System (ADS)

Bhargavi, G.; Venu, V.; Renganathan, S.

2018-03-01

Microbial Fuel Cells (MFCs) are the promising devices which can produce electricity by anaerobic fermentation of organic / inorganic matter from easily metabolized biomass to complex wastewater using microbes as biocatalysts. MFC technology has been found as a potential technology for electricity generation and concomitant wastewater treatment. However, the high cost of the components and low efficiency are barricading the commercialization of MFC when compared with other energy generating systems. The performance of an MFC is largely relying on the reactor design and electrode materials. On the way to improve the efficiency of an MFC, tremendous exercises have been carried out to explore new electrode materials and reactor designs in recent decades. The current review is excogitated to amass the progress in design and electrode materials, which could bolster further investigations on MFCs to improve their performance, mitigate the cost and successful implementation of technology in field applications as well.

Bipolar Nickel-Metal Hydride Battery Development Project

NASA Technical Reports Server (NTRS)

Cole, John H.

1999-01-01

This paper reviews the development of the Electro Energy, Inc.'s bipolar nickel metal hydride battery. The advantages of the design are that each cell is individually sealed, and that there are no external cell terminals, no electrode current collectors, it is compatible with plastic bonded electrodes, adaptable to heat transfer fins, scalable to large area, capacity and high voltage. The design will allow for automated flexible manufacturing, improved energy and power density and lower cost. The development and testing of the battery's component are described. Graphic presentation of the results of many of the tests are included.

Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels

PubMed Central

Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

2015-01-01

We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1 Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs. PMID:26582471

Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels.

PubMed

Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

2015-11-19

We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1 Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs.

Indium-free, highly transparent, flexible Cu2O/Cu/Cu2O mesh electrodes for flexible touch screen panels

NASA Astrophysics Data System (ADS)

Kim, Dong-Ju; Kim, Hyo-Joong; Seo, Ki-Won; Kim, Ki-Hyun; Kim, Tae-Wong; Kim, Han-Ki

2015-11-01

We report on an indium-free and cost-effective Cu2O/Cu/Cu2O multilayer mesh electrode grown by room temperature roll-to-roll sputtering as a viable alternative to ITO electrodes for the cost-effective production of large-area flexible touch screen panels (TSPs). By using a low resistivity metallic Cu interlayer and a patterned mesh structure, we obtained Cu2O/Cu/Cu2O multilayer mesh electrodes with a low sheet resistance of 15.1 Ohm/square and high optical transmittance of 89% as well as good mechanical flexibility. Outer/inner bending test results showed that the Cu2O/Cu/Cu2O mesh electrode had a mechanical flexibility superior to that of conventional ITO films. Using the diamond-patterned Cu2O/Cu/Cu2O multilayer mesh electrodes, we successfully demonstrated TSPS of the flexible film-film type and rigid glass-film-film type TSPs. The TSPs with Cu2O/Cu/Cu2O mesh electrode were used to perform zoom in/out functions and multi-touch writing, indicating that these electrodes are promising cost-efficient transparent electrodes to substitute for conventional ITO electrodes in large-area flexible TSPs.

Toward highly efficient electrocatalyst for Li–O 2 batteries using biphasic N-doping cobalt@graphene multiple-capsule heterostructures

DOE PAGES

Tan, Guoqiang; Chong, Lina; Amine, Rachid; ...

2017-04-12

To promote lithium-oxygen batteries available for practical applications, the development of advanced cathode catalysts with low-cost, high activity and stable structural properties is demanded. Such development is rooted on certain intelligent catalyst-electrode design that fundamentally facilitates electronic and ionic transport, and improves oxygen diffusivity in a porous environment. Here we design a biphasic nitrogen-doped cobalt@graphene multiple-capsule heterostructure, combined with a flexible, stable porous electrode architecture, and apply it as promising cathodes for lithium-oxygen cells. The biphasic nitrogen-doping feature improves the electric conductivity and catalytic activity; the multiple-nanocapsule configuration makes high/uniform electro-active zones possible; furthermore, the colander-like porous electrode facilitates themore » oxygen diffusion, catalytic reaction, and stable deposition of discharge products. Finally, the electrode exhibits much improved electrocatalytic properties associated with unique morphologies of electrochemically grown lithium peroxides.« less

Toward highly efficient electrocatalyst for Li–O 2 batteries using biphasic N-doping cobalt@graphene multiple-capsule heterostructures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tan, Guoqiang; Chong, Lina; Amine, Rachid

To promote lithium-oxygen batteries available for practical applications, the development of advanced cathode catalysts with low-cost, high activity and stable structural properties is demanded. Such development is rooted on certain intelligent catalyst-electrode design that fundamentally facilitates electronic and ionic transport, and improves oxygen diffusivity in a porous environment. Here we design a biphasic nitrogen-doped cobalt@graphene multiple-capsule heterostructure, combined with a flexible, stable porous electrode architecture, and apply it as promising cathodes for lithium-oxygen cells. The biphasic nitrogen-doping feature improves the electric conductivity and catalytic activity; the multiple-nanocapsule configuration makes high/uniform electro-active zones possible; furthermore, the colander-like porous electrode facilitates themore » oxygen diffusion, catalytic reaction, and stable deposition of discharge products. Finally, the electrode exhibits much improved electrocatalytic properties associated with unique morphologies of electrochemically grown lithium peroxides.« less

Toward Highly Efficient Electrocatalyst for Li-O2 Batteries Using Biphasic N-Doping Cobalt@Graphene Multiple-Capsule Heterostructures.

PubMed

Tan, Guoqiang; Chong, Lina; Amine, Rachid; Lu, Jun; Liu, Cong; Yuan, Yifei; Wen, Jianguo; He, Kun; Bi, Xuanxuan; Guo, Yuanyuan; Wang, Hsien-Hau; Shahbazian-Yassar, Reza; Al Hallaj, Said; Miller, Dean J; Liu, Dijia; Amine, Khalil

2017-05-10

For the promotion of lithium-oxygen batteries available for practical applications, the development of advanced cathode catalysts with low-cost, high activity, and stable structural properties is demanded. Such development is rooted on certain intelligent catalyst-electrode design that fundamentally facilitates electronic and ionic transport and improves oxygen diffusivity in a porous environment. Here we design a biphasic nitrogen-doped cobalt@graphene multiple-capsule heterostructure, combined with a flexible, stable porous electrode architecture, and apply it as promising cathodes for lithium-oxygen cells. The biphasic nitrogen-doping feature improves the electric conductivity and catalytic activity; the multiple-nanocapsule configuration makes high/uniform electroactive zones possible; furthermore, the colander-like porous electrode facilitates the oxygen diffusion, catalytic reaction, and stable deposition of discharge products. As a result, the electrode exhibits much improved electrocatalytic properties associated with unique morphologies of electrochemically grown lithium peroxides.

A new disposable electrode for electrochemical study of leukemia K562 cells and anticancer drug sensitivity test.

PubMed

Yu, Chunmei; Zhu, Zhenkun; Wang, Li; Wang, Qiuhong; Bao, Ning; Gu, Haiying

2014-03-15

Developing cost-effective and simple analysis tools is of vital importance for practical applications in bioanalysis. In this work, a new disposable electrochemical cell sensor with low cost and simple fabrication was proposed to study the electrochemical behavior of leukemia K562 cells and the effect of anticancer drugs on cell viability. The analytical device was integrated by using ITO glass as the substrate of working electrodes and paper as the electrolytic cell. The cyclic voltammetry of the K562 cells at the disposable electrode exhibited an irreversible anodic peak and the peak current is proportional to the cell number. This anodic peak is attributed to the oxidation of guanine in cells involving two protons per transfer of two electrons. For the drug sensitivity tests, arsenic trioxide and cyclophosphamide were added to cell culture media. As a result, the electrochemical responses of the K562 cells decreased significantly. The cytotoxicity curves and results obtained corresponded well with the results of CCK-8 assays. In comparison to conventional methods, the proposed method is simple, rapid and inexpensive. More importantly, the developed sensor is supposed to be a single-use disposable device and electrodes were prepared "as new" for each experiment. We think that such disposable electrodes with these characteristics are suitable for experimental study with cancer cells or other types of pathogens for disease diagnosis, drug selection and on-site monitoring. © 2013 Elsevier B.V. All rights reserved.

Surface Electrochemical Modification of a Nickel Substrate to Prepare a NiFe-based Electrode for Water Oxidation.

PubMed

Guo, Dingyi; Qi, Jing; Zhang, Wei; Cao, Rui

2017-01-20

The slow kinetics of water oxidation greatly jeopardizes the efficiency of water electrolysis for H 2 production. Developing highly active water oxidation electrodes with affordable fabrication costs is thus of great importance. Herein, a Ni II Fe III surface species on Ni metal substrate was generated by electrochemical modification of Ni in a ferrous solution by a fast, simple, and cost-effective procedure. In the prepared Ni II Fe III catalyst film, Fe III was incorporated uniformly through controlled oxidation of Fe II cations on the electrode surface. The catalytically active Ni II originated from the Ni foam substrate, which ensured the close contact between the catalyst and the support toward improved charge-transfer efficiency. The as-prepared electrode exhibited high activity and long-term stability for electrocatalytic water oxidation. The overpotentials required to reach water oxidation current densities of 50, 100, and 500 mA cm -2 are 276, 290, and 329 mV, respectively. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Final Report - Advanced Cathode Catalysts and Supports for PEM Fuel Cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

Debe, Mark

2012-09-28

The principal objectives of the program were development of a durable, low cost, high performance cathode electrode (catalyst and support), that is fully integrated into a fuel cell membrane electrode assembly with gas diffusion media, fabricated by high volume capable processes, and is able to meet or exceed the 2015 DOE targets. Work completed in this contract was an extension of the developments under three preceding cooperative agreements/grants Nos. DE-FC-02-97EE50473, DE-FC-99EE50582 and DE-FC36- 02AL67621 which investigated catalyzed membrane electrode assemblies for PEM fuel cells based on a fundamentally new, nanostructured thin film catalyst and support system, and demonstrated the feasibilitymore » for high volume manufacturability.« less

Inkjet-Printed Electrodes on A4 Paper Substrates for Low-Cost, Disposable, and Flexible Asymmetric Supercapacitors.

PubMed

Sundriyal, Poonam; Bhattacharya, Shantanu

2017-11-08

Printed electronics is widely gaining much attention for compact and high-performance energy-storage devices because of the advancement of flexible electronics. The development of a low-cost current collector, selection, and utilization of the proper material deposition tool and improvement of the device energy density are major challenges for the existing flexible supercapacitors. In this paper, we have reported an inkjet-printed solid-state asymmetric supercapacitor on commercial A4 paper using a low-cost desktop printer (EPSON L130). The physical properties of all inks have been carefully optimized so that the developed inks are within the printable range, i.e., Fromm number of 4 < Z < 14 for all inks. The paper substrate is made conducting (sheet resistance ∼ 1.6 Ω/sq) by printing 40 layers of conducting graphene oxide (GO) ink on its surface. The developed conducting patterns on paper are further printed with a GO-MnO 2 nanocomposite ink to make a positive electrode, and another such structure is printed with activated carbon ink to form a negative electrode. A combination of both of these electrodes is outlaid by fabricating an asymmetric supercapacitor. The assembled asymmetric supercapacitor with poly(vinyl alcohol) (PVA)-LiCl gel electrolyte shows a stable potential window of 0-2.0 V and exhibits outstanding flexibility, good cyclic stability, high rate capability, and high energy density. The fabricated paper-substrate-based flexible asymmetric supercapacitor also displays an excellent electrochemical performances, e.g., a maximum areal capacitance of 1.586 F/cm 2 (1023 F/g) at a current density of 4 mA/cm 2 , highest energy density of 22 mWh/cm 3 at a power density of 0.099 W/cm 3 , a capacity retention of 89.6% even after 9000 charge-discharge cycles, and a low charge-transfer resistance of 2.3 Ω. So, utilization of inkjet printing for the development of paper-based flexible electronics has a strong potential for embedding into the next generation low-cost, compact, and wearable energy-storage devices and other printed electronic applications.

Comparative analysis for various redox flow batteries chemistries using a cost performance model

NASA Astrophysics Data System (ADS)

Crawford, Alasdair; Viswanathan, Vilayanur; Stephenson, David; Wang, Wei; Thomsen, Edwin; Reed, David; Li, Bin; Balducci, Patrick; Kintner-Meyer, Michael; Sprenkle, Vincent

2015-10-01

The total energy storage system cost is determined by means of a robust performance-based cost model for multiple flow battery chemistries. Systems aspects such as shunt current losses, pumping losses and various flow patterns through electrodes are accounted for. The system cost minimizing objective function determines stack design by optimizing the state of charge operating range, along with current density and current-normalized flow. The model cost estimates are validated using 2-kW stack performance data for the same size electrodes and operating conditions. Using our validated tool, it has been demonstrated that an optimized all-vanadium system has an estimated system cost of < 350 kWh-1 for 4-h application. With an anticipated decrease in component costs facilitated by economies of scale from larger production volumes, coupled with performance improvements enabled by technology development, the system cost is expected to decrease to 160 kWh-1 for a 4-h application, and to 100 kWh-1 for a 10-h application. This tool has been shared with the redox flow battery community to enable cost estimation using their stack data and guide future direction.

Vertically aligned carbon nanofiber electrode arrays for nucleic acid detection

NASA Astrophysics Data System (ADS)

Arumugam, Prabhu U.; Yu, Edmond; Riviere, Roger; Meyyappan, M.

2010-10-01

We present electrochemical detection of DNA targets that corresponds to Escherichia coli O157:H7 16S rRNA gene using a nanoelectrode array consisting of vertically aligned carbon nanofiber (VACNF) electrodes. Parylene C is used as gap filling 'matrix' material to avoid high temperature processing in electrode construction. This easy to deposit film of several micron heights provides a conformal coating between the high aspect ratio VACNFs with negligible pin-holes. The low background currents show the potential of this approach for ultra-sensitive detection. Consistent and reproducible electrochemical-signals are achieved using a simple electrode preparation. This simple, reliable and low-cost approach is a forward step in developing practical sensors for applications like pathogen detection, early cancer diagnosis and environmental monitoring.

Low-temperature solution processing of palladium/palladium oxide films and their pH sensing performance.

PubMed

Qin, Yiheng; Alam, Arif U; Pan, Si; Howlader, Matiar M R; Ghosh, Raja; Selvaganapathy, P Ravi; Wu, Yiliang; Deen, M Jamal

2016-01-01

Highly sensitive, easy-to-fabricate, and low-cost pH sensors with small dimensions are required to monitor human bodily fluids, drinking water quality and chemical/biological processes. In this study, a low-temperature, solution-based process is developed to prepare palladium/palladium oxide (Pd/PdO) thin films for pH sensing. A precursor solution for Pd is spin coated onto pre-cleaned glass substrates and annealed at low temperature to generate Pd and PdO. The percentages of PdO at the surface and in the bulk of the electrodes are correlated to their sensing performance, which was studied by using the X-ray photoelectron spectroscope. Large amounts of PdO introduced by prolonged annealing improve the electrode's sensitivity and long-term stability. Atomic force microscopy study showed that the low-temperature annealing results in a smooth electrode surface, which contributes to a fast response. Nano-voids at the electrode surfaces were observed by scanning electron microscope, indicating a reason for the long-term degradation of the pH sensitivity. Using the optimized annealing parameters of 200°C for 48 h, a linear pH response with sensitivity of 64.71±0.56 mV/pH is obtained for pH between 2 and 12. These electrodes show a response time shorter than 18 s, hysteresis less than 8 mV and stability over 60 days. High reproducibility in the sensing performance is achieved. This low-temperature solution-processed sensing electrode shows the potential for the development of pH sensing systems on flexible substrates over a large area at low cost without using vacuum equipment. Copyright © 2015 Elsevier B.V. All rights reserved.

Commercial aerospace and terrestrial applications of nickel-hydrogen batteries

NASA Astrophysics Data System (ADS)

Caldwell, Dwight B.; Coates, Dwaine K.; Fox, Chris L.; Miller, Lee E.

1996-03-01

The nickel-hydrogen battery system, used extensively in the aerospace industry to supply electrical power to earth-orbital satellites for communications, observation, and military applications, is being developed for commercial, terrestrial applications. Low-cost components, electrodes, cell designs, and battery designs are currently being tested. Catalytic hydrogen electrodes have been developed which are compatible with commercial nickel battery cost. Prismatic and spiral-wound cell designs have been built and tested. Common pressure vessel and dependent pressure vessel battery designs are also being evaluated. The nickel-hydrogen battery offers potential cycle life unequaled by any other battery system. This makes the battery ideal for many commercial and terrestrial energy storage applications such as telecommunication, remote stand-alone power systems, utility load-leveling, and other applications which require long life and a truly maintenance-free and abuse-tolerant battery system.

A Comparative evaluation of Graphene oxide based materials for Electrochemical non-enzymatic sensing of Curcumin

NASA Astrophysics Data System (ADS)

Dey, Nibedita; Devasena, T.; Sivalingam, Tamilarasu

2018-02-01

This work reports a comparative study on the development of a sensitive voltammetric method for the assay of diferuloylmethane which is fabricated using cost-effective sensing material graphene oxide (GO modified electrode) and reduced graphene oxide (rGO modified electrode) modified on glassy carbon electrode respectively. The prepared materials were characterized using SEM, XRD, FTIR, and Raman techniques to understand the formation. Between the both modified electrodes, rGO modified electrode demonstrated a lower limit detection of 0.9 pM and good signal quality. But, the better linear dynamic range for detection was found to be 1 nm to 100 nM for GO and 0.1 nM to 10 nM for rGO modified electrodes respectively. The repeatability is checked for seven cycles and interference studies were also performed for checking the sensors’ selectivity to curcumin. rGO modified electrode and GO modified electrode both shows specific signals for Diferuloylmethane under conditions similar to physiology. But, with better properties over GO modified electrode, rGO modified electrode is suggested a better candidate for real-time usability in sensing. The detection limit reported is the lowest till date for the given plant drug using any sensing assay.

Recent Advances in Polymeric Materials Used as Electron Mediators and Immobilizing Matrices in Developing Enzyme Electrodes

PubMed Central

Moyo, Mambo; Okonkwo, Jonathan O.; Agyei, Nana M.

2012-01-01

Different classes of polymeric materials such as nanomaterials, sol-gel materials, conducting polymers, functional polymers and biomaterials have been used in the design of sensors and biosensors. Various methods have been used, for example from direct adsorption, covalent bonding, crossing-linking with glutaraldehyde on composites to mixing the enzymes or use of functionalized beads for the design of sensors and biosensors using these polymeric materials in recent years. It is widely acknowledged that analytical sensing at electrodes modified with polymeric materials results in low detection limits, high sensitivities, lower applied potential, good stability, efficient electron transfer and easier immobilization of enzymes on electrodes such that sensing and biosensing of environmental pollutants is made easier. However, there are a number of challenges to be addressed in order to fulfill the applications of polymeric based polymers such as cost and shortening the long laboratory synthetic pathways involved in sensor preparation. Furthermore, the toxicological effects on flora and fauna of some of these polymeric materials have not been well studied. Given these disadvantages, efforts are now geared towards introducing low cost biomaterials that can serve as alternatives for the development of novel electrochemical sensors and biosensors. This review highlights recent contributions in the development of the electrochemical sensors and biosensors based on different polymeric material. The synergistic action of some of these polymeric materials and nanocomposites imposed when combined on electrode during sensing is discussed. PMID:22368503

Transparent Ti-In-Sn-O multicomponent anodes for highly efficient phosphorescent organic light emitting diodes

NASA Astrophysics Data System (ADS)

Lim, Jong-Wook; Jun Kang, Seong; Lee, Sunghun; Kim, Jang-Joo; Kim, Han-Ki

2012-07-01

We report on transparent Ti-In-Sn-O (TITO) multicomponent anodes prepared by co-sputtering anatase TiO2-x and ITO targets to produce highly efficient phosphorescent organic light emitting diodes (OLEDs). In spite of the incorporation of low cost TiO2, the crystalline TITO electrode annealed at temperature of 600 °C showed a sheet resistance of 18.06 Ω/sq, an optical transmittance of 87.96% at a wavelength of 550 nm, and a work function of 4.71 eV comparable to conventional ITO electrode. Both the quantum (21.69%) and power efficiencies (90.92 lm/W) of the phosphorescent OLED fabricated on the TITO anode were higher than those of the OLED with the reference ITO anode due to the high transparency of the TITO electrodes. This indicates that the TITO electrode is a promising indium-saving electrode that can replace high-cost ITO electrodes in the manufacture of low-cost, highly efficient phosphorescent OLEDs.

A single-electrode electrochemical system for multiplex electrochemiluminescence analysis based on a resistance induced potential difference.

PubMed

Gao, Wenyue; Muzyka, Kateryna; Ma, Xiangui; Lou, Baohua; Xu, Guobao

2018-04-28

Developing low-cost and simple electrochemical systems is becoming increasingly important but still challenged for multiplex experiments. Here we report a single-electrode electrochemical system (SEES) using only one electrode not only for a single experiment but also for multiplex experiments based on a resistance induced potential difference. SEESs for a single experiment and multiplex experiments are fabricated by attaching a self-adhesive label with a hole and multiple holes onto an ITO electrode, respectively. This enables multiplex electrochemiluminescence analysis with high sensitivity at a very low safe voltage using a smartphone as a detector. For the multiplex analysis, the SEES using a single electrode is much simpler, cheaper and more user-friendly than conventional electrochemical systems and bipolar electrochemical systems using electrode arrays. Moreover, SEESs are free from the electrochemiluminescent background problem from driving electrodes in bipolar electrochemical systems. Since numerous electrodes and cover materials can be used to fabricate SEESs readily and electrochemistry is being extensively used, SEESs are very promising for broad applications, such as drug screening and high throughput analysis.

Nickel-metal hydride battery development. Final technical report

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-06-01

Rechargeable batteries are used as the power source for a broad range of portable equipment. Key battery selection criteria typically are weight, volume, first cost, life cycle cost, and environmental impact. Rechargeable batteries are favored from a life cycle cost and environmental impact standpoint over primary batteries. The nickel-metal hydride (Ni-MH) battery system has emerged as the battery of choice for many applications based on its superior characteristics when judged on the above criteria against other battery types. In most cases commercial Ni-MH batteries are constructed with coiled electrodes in cylindrical metal containers. Electro Energy, Inc. (EEI) has been developingmore » a novel flat bipolar configuration of the Ni-MH system that offers weight, volume, and cost advantages when compared to cylindrical cells. The unique bipolar approach consists of fabricating individual flat wafer cells in conductive, carbon-filled, plastic face plates. The individual cells contain a nonconductive plastic border which is heat sealed around the perimeter to make a totally sealed unit cell. Multi-cell batteries are fabricated by stacking the individual wafer cells in such a way that the positive face of one cell contacts the negative face of the adjacent cell. The stack is then contained in an outer housing with end contacts. The purpose of this program was to develop, evaluate, and demonstrate the capabilities of the EEI Ni-MH battery system for consumer applications. The work was directed at the development and evaluation of the compact bipolar construction for its potential advantages of high power and energy density. Experimental investigations were performed on various nickel electrode types, hydride electrode formulations, and alternate separator materials. Studies were also directed at evaluating various oxygen recombination techniques for low pressure operation during charge and overcharge.« less

Polyanion-Type Electrode Materials for Sodium-Ion Batteries.

PubMed

Ni, Qiao; Bai, Ying; Wu, Feng; Wu, Chuan

2017-03-01

Sodium-ion batteries, representative members of the post-lithium-battery club, are very attractive and promising for large-scale energy storage applications. The increasing technological improvements in sodium-ion batteries (Na-ion batteries) are being driven by the demand for Na-based electrode materials that are resource-abundant, cost-effective, and long lasting. Polyanion-type compounds are among the most promising electrode materials for Na-ion batteries due to their stability, safety, and suitable operating voltages. The most representative polyanion-type electrode materials are Na 3 V 2 (PO 4 ) 3 and NaTi 2 (PO 4 ) 3 for Na-based cathode and anode materials, respectively. Both show superior electrochemical properties and attractive prospects in terms of their development and application in Na-ion batteries. Carbonophosphate Na 3 MnCO 3 PO 4 and amorphous FePO 4 have also recently emerged and are contributing to further developing the research scope of polyanion-type Na-ion batteries. However, the typical low conductivity and relatively low capacity performance of such materials still restrict their development. This paper presents a brief review of the research progress of polyanion-type electrode materials for Na-ion batteries, summarizing recent accomplishments, highlighting emerging strategies, and discussing the remaining challenges of such systems.

Preparation of PEMFC Electrodes from Milligram-Amounts of Catalyst Powder

DOE PAGES

Yarlagadda, Venkata; McKinney, Samuel E.; Keary, Cristin L.; ...

2017-06-03

Development of electrocatalysts with higher activity and stability is one of the highest priorities in enabling cost-competitive hydrogen-air fuel cells. Although the rotating disk electrode (RDE) technique is widely used to study new catalyst materials, it has been often shown to be an unreliable predictor of catalyst performance in actual fuel cell operation. Fabrication of membrane electrode assemblies (MEA) for evaluation which are more representative of actual fuel cells generally requires relatively large amounts (>1 g) of catalyst material which are often not readily available in early stages of development. In this study, we present two MEA preparation techniques usingmore » as little as 30 mg of catalyst material, providing methods to conduct more meaningful MEA-based tests using research-level catalysts amounts.« less

Perylene-Based All-Organic Redox Battery with Excellent Cycling Stability.

PubMed

Iordache, Adriana; Delhorbe, Virginie; Bardet, Michel; Dubois, Lionel; Gutel, Thibaut; Picard, Lionel

2016-09-07

Organic materials derived from biomass can constitute a viable option as replacements for inorganic materials in lithium-ion battery electrodes owing to their low production costs, recyclability, and structural diversity. Among them, conjugated carbonyls have become the most promising type of organic electrode material as they present high theoretical capacity, fast reaction kinetics, and quasi-infinite structural diversity. In this letter, we report a new perylene-based all-organic redox battery comprising two aromatic conjugated carbonyl electrode materials, the prelithiated tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi6) as negative electrode material and the poly(N-n-hexyl-3,4,9,10-perylene tetracarboxylic)imide (PTCI) as positive electrode material. The resulting battery shows promising long-term cycling stability up to 200 cycles. In view of the enhanced cycling performances, the two organic materials studied herein are proposed as suitable candidates for the development of new all-organic lithium-ion batteries.

Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode

PubMed Central

Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

2014-01-01

Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode. PMID:24763248

Ultrasmooth, extremely deformable and shape recoverable Ag nanowire embedded transparent electrode.

PubMed

Nam, Sanggil; Song, Myungkwan; Kim, Dong-Ho; Cho, Byungjin; Lee, Hye Moon; Kwon, Jung-Dae; Park, Sung-Gyu; Nam, Kee-Seok; Jeong, Yongsoo; Kwon, Se-Hun; Park, Yun Chang; Jin, Sung-Ho; Kang, Jae-Wook; Jo, Sungjin; Kim, Chang Su

2014-04-25

Transparent electrodes have been widely used in electronic devices such as solar cells, displays, and touch screens. Highly flexible transparent electrodes are especially desired for the development of next generation flexible electronic devices. Although indium tin oxide (ITO) is the most commonly used material for the fabrication of transparent electrodes, its brittleness and growing cost limit its utility for flexible electronic devices. Therefore, the need for new transparent conductive materials with superior mechanical properties is clear and urgent. Ag nanowire (AgNW) has been attracting increasing attention because of its effective combination of electrical and optical properties. However, it still suffers from several drawbacks, including large surface roughness, instability against oxidation and moisture, and poor adhesion to substrates. These issues need to be addressed before wide spread use of metallic NW as transparent electrodes can be realized. In this study, we demonstrated the fabrication of a flexible transparent electrode with superior mechanical, electrical and optical properties by embedding a AgNW film into a transparent polymer matrix. This technique can produce electrodes with an ultrasmooth and extremely deformable transparent electrode that have sheet resistance and transmittance comparable to those of an ITO electrode.

High-performance supercapacitor electrode from cellulose-derived, inter-bonded carbon nanofibers

NASA Astrophysics Data System (ADS)

Cai, Jie; Niu, Haitao; Wang, Hongxia; Shao, Hao; Fang, Jian; He, Jingren; Xiong, Hanguo; Ma, Chengjie; Lin, Tong

2016-08-01

Carbon nanofibers with inter-bonded fibrous structure show high supercapacitor performance when being used as electrode materials. Their preparation is highly desirable from cellulose through a pyrolysis technique, because cellulose is an abundant, low cost natural material and its carbonization does not emit toxic substance. However, interconnected carbon nanofibers prepared from electrospun cellulose nanofibers and their capacitive behaviors have not been reported in the research literature. Here we report a facile one-step strategy to prepare inter-bonded carbon nanofibers from partially hydrolyzed cellulose acetate nanofibers, for making high-performance supercapacitors as electrode materials. The inter-fiber connection shows considerable improvement in electrode electrochemical performances. The supercapacitor electrode has a specific capacitance of ∼241.4 F g-1 at 1 A g-1 current density. It maintains high cycling stability (negligible 0.1% capacitance reduction after 10,000 cycles) with a maximum power density of ∼84.1 kW kg-1. They may find applications in the development of efficient supercapacitor electrodes for energy storage applications.

3D-nanostructured Au electrodes for the event-specific detection of MON810 transgenic maize.

PubMed

Fátima Barroso, M; Freitas, Maria; Oliveira, M Beatriz P P; de-Los-Santos-Álvarez, Noemí; Lobo-Castañón, María Jesús; Delerue-Matos, Cristina

2015-03-01

In the present work, the development of a genosensor for the event-specific detection of MON810 transgenic maize is proposed. Taking advantage of nanostructuration, a cost-effective three dimensional electrode was fabricated and a ternary monolayer containing a dithiol, a monothiol and the thiolated capture probe was optimized to minimize the unspecific signals. A sandwich format assay was selected as a way of precluding inefficient hybridization associated with stable secondary target structures. A comparison between the analytical performance of the Au nanostructured electrodes and commercially available screen-printed electrodes highlighted the superior performance of the nanostructured ones. Finally, the genosensor was effectively applied to detect the transgenic sequence in real samples, showing its potential for future quantitative analysis. Copyright © 2014 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

Fabrication and performance of Li4Ti5O12/C Li-ion battery electrodes using combined double flame spray pyrolysis and pressure-based lamination technique

NASA Astrophysics Data System (ADS)

Gockeln, Michael; Pokhrel, Suman; Meierhofer, Florian; Glenneberg, Jens; Schowalter, Marco; Rosenauer, Andreas; Fritsching, Udo; Busse, Matthias; Mädler, Lutz; Kun, Robert

2018-01-01

Reduction of lithium-ion battery (LIB) production costs is inevitable to make the use of LIB technology more viable for applications such as electric vehicles or stationary storage. To meet the requirements in today's LIB cost efficiency, our current research focuses on an alternative electrode fabrication method, characterized by a combination of double flame spray pyrolysis and lamination technique (DFSP/lamination). In-situ carbon coated nano-Li4Ti5O12 (LTO/C) was synthesized using versatile DFSP. The as-prepared composite powder was then directly laminated onto a conductive substrate avoiding the use of any solvent or binder for electrode preparation. The influence of lamination pressures on the microstructure and electrochemical performance of the electrodes was also investigated. Enhancements in intrinsic electrical conductivity were found for higher lamination pressures. Capacity retention of highest pressurized DFSP/lamination-prepared electrode was 87.4% after 200 dis-/charge cycles at 1C (vs. Li). In addition, LTO/C material prepared from the double flame spray pyrolysis was also used for fabricating electrodes via doctor blading technique. Laminated electrodes obtained higher specific discharge capacities compared to calendered and non-calendered blade-casted electrodes due to superior microstructural properties. Such a fast and industrially compelling integrative DFSP/lamination tool could be a prosperous, next generation technology for low-cost LIB electrode fabrication.

Small-Scale and Low Cost Electrodes for "Standard" Reduction Potential Measurements

ERIC Educational Resources Information Center

Eggen, Per-Odd; Kvittingen, Lise

2007-01-01

The construction of three simple and inexpensive electrodes, hydrogen, and chlorine and copper electrode is described. This simple method will encourage students to construct their own electrode and better help in understanding precipitation and other electrochemistry concepts.

Low-cost and disposable pressure sensor mat for non-invasive sleep and movement monitoring applications.

PubMed

Abraham, Jose K; Sullivan, Shawn; Ranganathan, Sridhar

2011-01-01

Sleep has profound effects on the physical and mental well-being of an individual. The National Institutes of Health (NIH) Sleep Disorder Research Plan gives particular emphasis to non-invasive sleep monitoring methods. Older adults experience sleep fragmentation due to sleep disorders. Unobtrusive non-contact monitoring can be the only realistic solution for long term home-based sleep monitoring. The demand for a low-cost and non-invasive sleep monitoring system for in-home use is more than before due to an increasingly stressful life style. Cost and complexity of current sensor elements hinder the development of low-cost sleep monitoring devices for in-home use. This paper presents the design, development and implementation of a low-cost and disposable pressure sensor mat that could be useful for in-home sleep and movement monitoring applications. The sensor mat design is based on a compressible foam sandwiched between two orthogonal arrays of cPaper capacitance sensors. A low-cost conducting paper has been developed for use as the capacitance sensor electrode. Typical mat design uses a 3 mm thick foam with 5 mm row/column grid array shows that it has a measurement resolution of 0.1 PSI pressure. The resolution can be controlled by both modifying properties of the conducting paper and the foam. Since this pressure mat design is based on low-cost paper, the sensor electrodes are disposable or semi-durable and hence it is ideal for the use in point-of-care physiological monitoring, pervasive healthcare and consumer electronic devices.

Cost-Effectiveness of POC Coagulation Testing Using Multiple Electrode Aggregometry.

PubMed

Straub, Niels; Bauer, Ekaterina; Agarwal, Seema; Meybohm, Patrick; Zacharowski, Kai; Hanke, Alexander A; Weber, Christian F

2016-01-01

The economic effects of Point-of-Care (POC) coagulation testing including Multiple Electrode Aggregometry (MEA) with the Multiplate device have not been examined. A health economic model with associated clinical endpoints was developed to calculate the effectiveness and estimated costs of coagulation analyses based on standard laboratory testing (SLT) or POC testing offering the possibility to assess platelet dysfunction using aggregometric measures. Cost estimates included pre- and perioperative costs of hemotherapy, intra- and post-operative coagulation testing costs, and hospitalization costs, including the costs of transfusion-related complications. Our model calculation using a simulated true-to-life cohort of 10,000 cardiac surgery patients assigned to each testing alternative demonstrated that there were 950 fewer patients in the POC branch who required any transfusion of red blood cells. The subsequent numbers of massive transfusions and patients with transfusion-related complications were reduced with the POC testing by 284 and 126, respectively. The average expected total cost in the POC branch was 288 Euro lower for every treated patient than that in the SLT branch. Incorporating aggregometric analyses using MEA into hemotherapy algorithms improved medical outcomes in cardiac surgery patients in the presented health economic model. There was an overall better economic outcome associated with POC testing compared with SLT testing despite the higher costs of testing.

NASA redox storage system development project

NASA Technical Reports Server (NTRS)

1983-01-01

The operating temperature was raised from 25 C to 65 C, which enhanced the kinetics of the chromium electrode charging reactions. The design of the auxiliary electrochemical cell, which is used to keep both reactants at the same state of charge, was modified, leading to better and more stable performance. Preliminary testing has shown that the four tank mode of operation improves energy efficiency as much as 5 percentage points over the conventional two tank mode. Another variation in operating mode, the use of mixed reactants, potentially offers several very attractive advantages. Preliminary reactant cost studies lend further weight to the feasibility of the mixed reactant concept. Electrode studies show that reproducibility of performance is very dependent on the pyrolysis temperature at which the carbon/graphite felt substrate is formed. Membrane development work continued to concentrate on cost reduction and the enhancement of resistivity and selectivity.

Enhancing Electrode Performance by Exsolved Nanoparticles: A Superior Cobalt-Free Perovskite Electrocatalyst for Solid Oxide Fuel Cells.

PubMed

Yang, Guangming; Zhou, Wei; Liu, Meilin; Shao, Zongping

2016-12-28

The successful development of low-cost, durable electrocatalysts for oxygen reduction reaction (ORR) at intermediate temperatures is critical for broad commercialization of solid oxide fuel cells. Here, we report our findings in design, fabrication, and characterization of a cobalt-free SrFe 0.85 Ti 0.1 Ni 0.05 O 3-δ cathode decorated with NiO nanoparticles. Exsolved from and well bonded to the parent electrode under well-controlled conditions, the NiO nanoparticles uniformly distributed on the surface of the parent electrode greatly enhance cathode performance, demonstrating ORR activity better than that of the benchmark cobalt-based Ba 0.5 Sr 0.5 Co 0.8 Fe 0.2 O 3-δ . Further, a process for regeneration of the NiO nanoparticles was also developed to mitigate potential performance degradation due to coarsening of NiO particles under practical operating conditions. As a general approach, this exsolution-dissolution of electrocatalytically active nanoparticles on an electrode surface may be applicable to the development of other high-performance cobalt-free cathodes for fuel cells and other electrochemical systems.

Spatiotemporal electrochemical measurements across an electric double layer capacitor electrode with application to aqueous sodium hybrid batteries

NASA Astrophysics Data System (ADS)

Tully, Katherine C.; Whitacre, Jay F.; Litster, Shawn

2014-02-01

This paper presents in-situ spatiotemporal measurements of the electrolyte phase potential within an electric double layer capacitor (EDLC) negative electrode as envisaged for use in an aqueous hybrid battery for grid-scale energy storage. The ultra-thick electrodes used in these batteries to reduce non-functional material costs require sufficiently fast through-plane mass and charge transport to attain suitable charging and discharging rates. To better evaluate the through-plane transport, we have developed an electrode scaffold (ES) for making in situ electrolyte potential distribution measurements at discrete known distances across the thickness of an uninterrupted EDLC negative electrode. Using finite difference methods, we calculate local current, volumetric charging current and charge storage distributions from the spatiotemporal electrolyte potential measurements. These potential distributions provide insight into complex phenomena that cannot be directly observed using other existing methods. Herein, we use the distributions to identify areas of the electrode that are underutilized, assess the effects of various parameters on the cumulative charge storage distribution, and evaluate an effectiveness factor for charge storage in EDLC electrodes.

DEVELOPMENT OF A SCALABLE, LOW-COST, ULTRANANOCRYSTALLINE DIAMOND ELECTROCHEMICAL PROCESS FOR THE DESTRUCTION OF CONTAMINANTS OF EMERGING CONCERN (CECS) - PHASE II

EPA Science Inventory

This Small Business Innovation Research (SBIR) Phase II project will employ the large scale; highly reliable boron-doped ultrananocrystalline diamond (BD-UNCD®) electrodes developed during Phase I project to build and test Electrochemical Anodic Oxidation process (EAOP)...

Concept and Development of an Electronic Framework Intended for Electrode and Surrounding Environment Characterization In Vivo

PubMed Central

Rieger, Stefan B.; Pfau, Jennifer; Stieglitz, Thomas; Asplund, Maria; Ordonez, Juan S.

2016-01-01

There has been substantial progress over the last decade towards miniaturizing implantable microelectrodes for use in Active Implantable Medical Devices (AIMD). Compared to the rapid development and complexity of electrode miniaturization, methods to monitor and assess functional integrity and electrical functionality of these electrodes, particularly during long term stimulation, have not progressed to the same extent. Evaluation methods that form the gold standard, such as stimulus pulse testing, cyclic voltammetry and electrochemical impedance spectroscopy, are either still bound to laboratory infrastructure (impractical for long term in vivo experiments) or deliver no comprehensive insight into the material’s behaviour. As there is a lack of cost effective and practical predictive measures to understand long term electrode behaviour in vivo, material investigations need to be performed after explantation of the electrodes. We propose the analysis of the electrode and its environment in situ, to better understand and correlate the effects leading to electrode failure. The derived knowledge shall eventually lead to improved electrode designs, increased electrode functionality and safety in clinical applications. In this paper, the concept, design and prototyping of a sensor framework used to analyse the electrode’s behaviour and to monitor diverse electrode failure mechanisms, even during stimulation pulses, is presented. We focused on the electronic circuitry and data acquisition techniques required for a conceptual multi-sensor system. Functionality of single modules and a prototype framework have been demonstrated, but further work is needed to convert the prototype system into an implantable device. In vitro studies will be conducted first to verify sensor performance and reliability. PMID:28042815

Economically synthesized NiCo2S4/reduced graphene oxide composite as efficient counter electrode in dye-sensitized solar cell

NASA Astrophysics Data System (ADS)

Nan, Hui; Han, Jianhua; Luo, Qiang; Yin, Xuewen; Zhou, Yu; Yao, Zhibo; Zhao, Xiaochong; Li, Xin; Lin, Hong

2018-04-01

Exploiting efficient Pt-free counter-electrode materials with low cost and highly catalytic property is a hot topic in the field of Dye-sensitized solar cells (DSCs). Here, NiCo2S4/reduced graphene oxide (RGO) was prepared via an economical synthesis route, and the as-prepared composite exhibited comparable electrocatalytic property with the conventional Pt electrode as the counter-electrode. Notably, the introduction of RGO into the NiCo2S4 counter-electrode induces a significantly promoted electrocatalytic rate towards the triiodide reduction than that of pristine NiCo2S4 by increasing surface area in the composite electrode, as revealed by electrochemical impedance spectroscopic measurement and Tafel polarization measurement. The easy synthesis, low cost and excellent electrochemical performance of the NiCo2S4/RGO composites enable themselves to serve as promising counter-electrode candidates for efficient DSCs.

Alkali metal ionization detector

DOEpatents

Bauerle, James E.; Reed, William H.; Berkey, Edgar

1978-01-01

Variations in the conventional filament and collector electrodes of an alkali metal ionization detector, including the substitution of helical electrode configurations for either the conventional wire filament or flat plate collector; or, the substitution of a plurality of discrete filament electrodes providing an in situ capability for transferring from an operationally defective filament electrode to a previously unused filament electrode without removing the alkali metal ionization detector from the monitored environment. In particular, the helical collector arrangement which is coaxially disposed about the filament electrode, i.e. the thermal ionizer, provides an improved collection of positive ions developed by the filament electrode. The helical filament design, on the other hand, provides the advantage of an increased surface area for ionization of alkali metal-bearing species in a monitored gas environment as well as providing a relatively strong electric field for collecting the ions at the collector electrode about which the helical filament electrode is coaxially positioned. Alternatively, both the filament and collector electrodes can be helical. Furthermore, the operation of the conventional alkali metal ionization detector as a leak detector can be simplified as to cost and complexity, by operating the detector at a reduced collector potential while maintaining the sensitivity of the alkali metal ionization detector adequate for the relatively low concentration of alkali vapor and aerosol typically encountered in leak detection applications.

Co-Percolating Graphene-Wrapped Silver Nanowire Network for High Performance, Highly Stable, Transparent Conducting Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chen, Ruiyi; Das, Suprem R; Jeong, Changwook

Transparent conducting electrodes (TCEs) require high transparency and low sheet resistance for applications in photovoltaics, photodetectors, flat panel displays, touch screen devices, and imagers. Indium tin oxide (ITO), or other transparent conductive oxides, have been used, and provide a baseline sheet resistance (RS) vs. transparency (T) relationship. Several alternative material systems have been investigated. The development of high-performance hybrid structures provides a route towards robust, scalable and low-cost approaches for realizing high-performance TCE.

Development of easy made low cost bindless monolithic electrodes from biomass with controlled properties to be used as electrochemical capacitors.

PubMed

Nabais, J M Valente; Teixeira, Jorge Ginja; Almeida, I

2011-02-01

The aim of the work now reported is the development of low cost electrodes in the monolithic shape without the need for a pos-production step with potential to be used in supercapacitors. The tested materials were activated carbon fibres prepared and activated carbons made from coffee endocarp. The main functional groups identified were quinone, lactone, Si-H, phenol, hydroxyl, carbonyl and ether for activated carbon samples and amine, amide, pyrone, lactone, carbonyl and hydroxyl for activated carbon fibres samples. The nanostructure of the materials is predominantly microporous but with a significant variety of porosity development with BET surface area and pore volume given by α(s) method range from 89 to 1050 m(2) g(-1) and 0.04 to 0.50 cm(3) g(-1), respectively. The electrochemical properties of the materials were investigated using classic cyclic voltammetry, chronopotentiometry and electrochemical impedance spectroscopy. The higher specific capacitance achieved was 176 F g(-1). Copyright © 2010 Elsevier Ltd. All rights reserved.

An Al-doped ZnO electrode grown by highly efficient cylindrical rotating magnetron sputtering for low cost organic photovoltaics

NASA Astrophysics Data System (ADS)

Park, Jun-Hyuk; Ahn, Kyung-Jun; Park, Kang-Il; Na, Seok-In; Kim, Han-Ki

2010-03-01

We report the characteristics of Al-doped zinc oxide (AZO) films prepared by a highly efficient cylindrical rotating magnetron sputtering (CRMS) system for use as a transparent conducting electrode in cost-efficient bulk hetero-junction organic solar cells (OSCs). Using a rotating cylindrical type cathode with an AZO target, whose usage was above 80%, we were able to obtain a low cost and indium free AZO electrode with a low sheet resistance of ~4.59 Ω/sq, a high transparency of 85% in the visible wavelength region and a work function of 4.9 eV at a substrate temperature of 230 °C. Moreover, the neutral poly(3,4-ethylenedioxythiophene) : poly(styrenesulfonate) based OSC fabricated on the CRMS-grown AZO electrode at 230 °C showed an open circuit voltage of 0.5 V, a short circuit current of 8.94 mA cm-2, a fill factor of 45% and power conversion efficiency of 2.01%, indicating that CRMS is a promising cost-efficient AZO deposition technique for low cost OSCs.

Embedded 32-bit Differential Pulse Voltammetry (DPV) Technique for 3-electrode Cell Sensing

NASA Astrophysics Data System (ADS)

N, Aqmar N. Z.; Abdullah, W. F. H.; Zain, Z. M.; Rani, S.

2018-03-01

This paper addresses the development of differential pulse voltammetry (DPV) embedded algorithm using an ARM cortex processor with new developed potentiostat circuit design for in-situ 3-electrode cell sensing. This project is mainly to design a low cost potentiostat for the researchers in laboratories. It is required to develop an embedded algorithm for analytical technique to be used with the designed potentiostat. DPV is one of the most familiar pulse technique method used with 3-electrode cell sensing in chemical studies. Experiment was conducted on 10mM solution of Ferricyanide using the designed potentiostat and the developed DPV algorithm. As a result, the device can generate an excitation signal of DPV from 0.4V to 1.2V and produced a peaked voltammogram with relatively small error compared to the commercial potentiostat; which is only 6.25% difference in peak potential reading. The design of potentiostat device and its DPV algorithm is verified.

Direct-current nanogenerator driven by ultrasonic waves.

PubMed

Wang, Xudong; Song, Jinhui; Liu, Jin; Wang, Zhong Lin

2007-04-06

We have developed a nanowire nanogenerator that is driven by an ultrasonic wave to produce continuous direct-current output. The nanogenerator was fabricated with vertically aligned zinc oxide nanowire arrays that were placed beneath a zigzag metal electrode with a small gap. The wave drives the electrode up and down to bend and/or vibrate the nanowires. A piezoelectric-semiconducting coupling process converts mechanical energy into electricity. The zigzag electrode acts as an array of parallel integrated metal tips that simultaneously and continuously create, collect, and output electricity from all of the nanowires. The approach presents an adaptable, mobile, and cost-effective technology for harvesting energy from the environment, and it offers a potential solution for powering nanodevices and nanosystems.

Recent Progress in Organic Electrodes for Li and Na Rechargeable Batteries.

PubMed

Lee, Sechan; Kwon, Giyun; Ku, Kyojin; Yoon, Kyungho; Jung, Sung-Kyun; Lim, Hee-Dae; Kang, Kisuk

2018-03-27

Organic rechargeable batteries, which use organics as electrodes, are excellent candidates for next-generation energy storage systems because they offer design flexibility due to the rich chemistry of organics while being eco-friendly and potentially cost efficient. However, their widespread usage is limited by intrinsic problems such as poor electronic conductivity, easy dissolution into liquid electrolytes, and low volumetric energy density. New types of organic electrode materials with various redox centers or molecular structures have been developed over the past few decades. Moreover, research aimed at enhancing electrochemical properties via chemical tuning has been at the forefront of organic rechargeable batteries research in recent years, leading to significant progress in their performance. Here, an overview of the current developments of organic rechargeable batteries is presented, with a brief history of research in this field. Various strategies for improving organic electrode materials are discussed with respect to tuning intrinsic properties of organics using molecular modification and optimizing their properties at the electrode level. A comprehensive understanding of the progress in organic electrode materials is provided along with the fundamental science governing their performance in rechargeable batteries thus a guide is presented to the optimal design strategies to improve the electrochemical performance for next-generation battery systems. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Carbon felt and carbon fiber - A techno-economic assessment of felt electrodes for redox flow battery applications

NASA Astrophysics Data System (ADS)

Minke, Christine; Kunz, Ulrich; Turek, Thomas

2017-02-01

Carbon felt electrodes belong to the key components of redox flow batteries. The purpose of this techno-economic assessment is to uncover the production costs of PAN- and rayon-based carbon felt electrodes. Raw material costs, energy demand and the impact of processability of fiber and felt are considered. This innovative, interdisciplinary approach combines deep insights into technical, ecologic and economic aspects of carbon felt and carbon fiber production. Main results of the calculation model are mass balances, cumulative energy demands (CED) and the production costs of conventional and biogenic carbon felts supplemented by market assessments considering textile and carbon fibers.

Bench-Top Fabrication of an All-PDMS Microfluidic Electrochemical Cell Sensor Integrating Micro/Nanostructured Electrodes.

PubMed

Saem, Sokunthearath; Zhu, Yujie; Luu, Helen; Moran-Mirabal, Jose

2017-03-31

In recent years, efforts in the development of lab-on-a-chip (LoC) devices for point-of-care (PoC) applications have increased to bring affordable, portable, and sensitive diagnostics to the patients' bedside. To reach this goal, research has shifted from using traditional microfabrication methods to more versatile, rapid, and low-cost options. This work focuses on the benchtop fabrication of a highly sensitive, fully transparent, and flexible poly (dimethylsiloxane) (PDMS) microfluidic (μF) electrochemical cell sensor. The μF device encapsulates 3D structured gold and platinum electrodes, fabricated using a shape-memory polymer shrinking method, which are used to set up an on-chip electrochemical cell. The PDMS to PDMS-structured electrode bonding protocol to fabricate the μF chip was optimized and found to have sufficient bond strength to withstand up to 100 mL/min flow rates. The sensing capabilities of the on-chip electrochemical cell were demonstrated by using cyclic voltammetry to monitor the adhesion of murine 3T3 fibroblasts in the presence of a redox reporter. The charge transfer across the working electrode was reduced upon cell adhesion, which was used as the detection mechanism, and allowed the detection of as few as 24 cells. The effective utilization of simple and low cost bench-top fabrication methods could accelerate the prototyping and development of LoC technologies and bring PoC diagnostics and personalized medicine to the patients' bedside.

Bench-Top Fabrication of an All-PDMS Microfluidic Electrochemical Cell Sensor Integrating Micro/Nanostructured Electrodes

PubMed Central

Saem, Sokunthearath; Zhu, Yujie; Luu, Helen; Moran-Mirabal, Jose

2017-01-01

In recent years, efforts in the development of lab-on-a-chip (LoC) devices for point-of-care (PoC) applications have increased to bring affordable, portable, and sensitive diagnostics to the patients’ bedside. To reach this goal, research has shifted from using traditional microfabrication methods to more versatile, rapid, and low-cost options. This work focuses on the benchtop fabrication of a highly sensitive, fully transparent, and flexible poly (dimethylsiloxane) (PDMS) microfluidic (μF) electrochemical cell sensor. The μF device encapsulates 3D structured gold and platinum electrodes, fabricated using a shape-memory polymer shrinking method, which are used to set up an on-chip electrochemical cell. The PDMS to PDMS-structured electrode bonding protocol to fabricate the μF chip was optimized and found to have sufficient bond strength to withstand up to 100 mL/min flow rates. The sensing capabilities of the on-chip electrochemical cell were demonstrated by using cyclic voltammetry to monitor the adhesion of murine 3T3 fibroblasts in the presence of a redox reporter. The charge transfer across the working electrode was reduced upon cell adhesion, which was used as the detection mechanism, and allowed the detection of as few as 24 cells. The effective utilization of simple and low cost bench-top fabrication methods could accelerate the prototyping and development of LoC technologies and bring PoC diagnostics and personalized medicine to the patients’ bedside. PMID:28362329

Inkjet printed multiwall carbon nanotube electrodes for dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Baechler, Curdin; Gardin, Samuele; Abuhimd, Hatem; Kovacs, Gabor

2016-05-01

Dielectric elastomers (DE’s) offer promising applications as soft and light-weight electromechanical actuators. It is known that beside the dielectric material, the electrode properties are of particular importance regarding the DE performance. Therefore, in recent years various studies have focused on the optimization of the electrode in terms of conductivity, stretchability and reliability. However, less attention was given to efficient electrode processing and deposition methods. In the present study, digital inkjet printing was used to deposit highly conductive and stretchable electrodes on silicone. Inkjet printing is a versatile and cost effective deposition method, which allows depositing complex-shaped electrode patterns with high precision. The electrodes were printed using an ink based on industrial low-cost MWCNT. Experiments have shown that the strain-conductivity properties of the printed electrode are strongly depended on the deposition parameters like drop-spacing and substrate temperature. After the optimization of the printing parameters, thin film electrodes could be deposited showing conductivities of up to 30 S cm-1 without the need of any post-treatment. In addition, electromechanical tests with fabricated DE actuators have revealed that the inkjet printed MWCNT electrodes are capable to self-clear in case of a dielectric breakdown.

Environmental Screening of Electrode Materials for a Rechargeable Aluminum Battery with an AlCl₃/EMIMCl Electrolyte.

PubMed

Ellingsen, Linda Ager-Wick; Holland, Alex; Drillet, Jean-Francois; Peters, Willi; Eckert, Martin; Concepcion, Carlos; Ruiz, Oscar; Colin, Jean-François; Knipping, Etienne; Pan, Qiaoyan; Wills, Richard G A; Majeau-Bettez, Guillaume

2018-06-01

Recently, rechargeable aluminum batteries have received much attention due to their low cost, easy operation, and high safety. As the research into rechargeable aluminum batteries with a room-temperature ionic liquid electrolyte is relatively new, research efforts have focused on finding suitable electrode materials. An understanding of the environmental aspects of electrode materials is essential to make informed and conscious decisions in aluminum battery development. The purpose of this study was to evaluate and compare the relative environmental performance of electrode material candidates for rechargeable aluminum batteries with an AlCl₃/EMIMCl (1-ethyl-3-methylimidazolium chloride) room-temperature ionic liquid electrolyte. To this end, we used a lifecycle environmental screening framework to evaluate 12 candidate electrode materials. We found that all of the studied materials are associated with one or more drawbacks and therefore do not represent a "silver bullet" for the aluminum battery. Even so, some materials appeared more promising than others did. We also found that aluminum battery technology is likely to face some of the same environmental challenges as Li-ion technology but also offers an opportunity to avoid others. The insights provided here can aid aluminum battery development in an environmentally sustainable direction.

Resolving Electrode Morphology’s Impact on Platinum Group Metal-Free Cathode Performance Using Nano-CT of 3D Hierarchical Pore and Ionomer Distribution

DOE Office of Scientific and Technical Information (OSTI.GOV)

Komini Babu, Siddharth; Chung, Hoon T.; Zelenay, Piotr

This paper reports on the characterization of polymer electrolyte fuel cell (PEFC) cathodes featuring a platinum group metal-free (PGM-free) catalyst using nano-scale resolution X-ray computed tomography (nano-CT) and morphological analysis. PGM-free PEFC cathodes have gained significant interest in the past decade since they have the potential to dramatically reduce PEFC costs by eliminating the large platinum (Pt) raw material cost. However, several challenges remain before they are commercially viable. Since these catalysts have lower volumetric activity, the PGM-free cathodes are thicker and are subject to increased gas and proton transport resistances that reduce the performance. To better understand the efficacymore » of the catalyst and improve electrode performance, a detailed understanding the correlation between electrode fabrication, morphology, and performance is crucial. In this work, the pore/solid structure and the ionomer distribution was resolved in three dimensions (3D) using nano-CT for three PGM-free electrodes of varying Nafion® loading. The associated transport properties were evaluated from pore/particlescale simulations within the nano-CT imaged structure. These characterizations are then used to elucidate the microstructural origins of the dramatic changes in fuel cell performance with varying Nafion® ionomer loading. We show that this is primarily a result of distinct changes in ionomer’s spatial distribution. The significant impact of electrode morphology on performance highlights the importance of PGM-free electrode development in concert with efforts to improve catalyst activity and durability.« less

Resolving Electrode Morphology’s Impact on Platinum Group Metal-Free Cathode Performance Using Nano-CT of 3D Hierarchical Pore and Ionomer Distribution

DOE PAGES

Komini Babu, Siddharth; Chung, Hoon T.; Zelenay, Piotr; ...

2016-11-02

This paper reports on the characterization of polymer electrolyte fuel cell (PEFC) cathodes featuring a platinum group metal-free (PGM-free) catalyst using nano-scale resolution X-ray computed tomography (nano-CT) and morphological analysis. PGM-free PEFC cathodes have gained significant interest in the past decade since they have the potential to dramatically reduce PEFC costs by eliminating the large platinum (Pt) raw material cost. However, several challenges remain before they are commercially viable. Since these catalysts have lower volumetric activity, the PGM-free cathodes are thicker and are subject to increased gas and proton transport resistances that reduce the performance. To better understand the efficacymore » of the catalyst and improve electrode performance, a detailed understanding the correlation between electrode fabrication, morphology, and performance is crucial. In this work, the pore/solid structure and the ionomer distribution was resolved in three dimensions (3D) using nano-CT for three PGM-free electrodes of varying Nafion® loading. The associated transport properties were evaluated from pore/particlescale simulations within the nano-CT imaged structure. These characterizations are then used to elucidate the microstructural origins of the dramatic changes in fuel cell performance with varying Nafion® ionomer loading. We show that this is primarily a result of distinct changes in ionomer’s spatial distribution. The significant impact of electrode morphology on performance highlights the importance of PGM-free electrode development in concert with efforts to improve catalyst activity and durability.« less

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes.

PubMed

Kawada, Shinichiro; Hayashi, Hiroyuki; Ishii, Hideki; Kimura, Masahiko; Ando, Akira; Omiya, Suetake; Kubodera, Noriyuki

2015-11-03

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain ( S max / E max ) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where S max denotes the maximum strain and E max denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed.

Potassium Sodium Niobate-Based Lead-Free Piezoelectric Multilayer Ceramics Co-Fired with Nickel Electrodes

PubMed Central

Kawada, Shinichiro; Hayashi, Hiroyuki; Ishii, Hideki; Kimura, Masahiko; Ando, Akira; Omiya, Suetake; Kubodera, Noriyuki

2015-01-01

Although lead-free piezoelectric ceramics have been extensively studied, many problems must still be overcome before they are suitable for practical use. One of the main problems is fabricating a multilayer structure, and one solution attracting growing interest is the use of lead-free multilayer piezoelectric ceramics. The paper reviews work that has been done by the authors on lead-free alkali niobate-based multilayer piezoelectric ceramics co-fired with nickel inner electrodes. Nickel inner electrodes have many advantages, such as high electromigration resistance, high interfacial strength with ceramics, and greater cost effectiveness than silver palladium inner electrodes. However, widely used lead zirconate titanate-based ceramics cannot be co-fired with nickel inner electrodes, and silver palladium inner electrodes are usually used for lead zirconate titanate-based piezoelectric ceramics. A possible alternative is lead-free ceramics co-fired with nickel inner electrodes. We have thus been developing lead-free alkali niobate-based multilayer ceramics co-fired with nickel inner electrodes. The normalized electric-field-induced thickness strain (Smax/Emax) of a representative alkali niobate-based multilayer ceramic structure with nickel inner electrodes was 360 pm/V, where Smax denotes the maximum strain and Emax denotes the maximum electric field. This value is about half that for the lead zirconate titanate-based ceramics that are widely used. However, a comparable value can be obtained by stacking more ceramic layers with smaller thicknesses. In the paper, the compositional design and process used to co-fire lead-free ceramics with nickel inner electrodes are introduced, and their piezoelectric properties and reliabilities are shown. Recent advances are introduced, and future development is discussed. PMID:28793646

Potassium-Based Dual Ion Battery with Dual-Graphite Electrode.

PubMed

Fan, Ling; Liu, Qian; Chen, Suhua; Lin, Kairui; Xu, Zhi; Lu, Bingan

2017-08-01

A potassium ion battery has potential applications for large scale electric energy storage systems due to the abundance and low cost of potassium resources. Dual graphite batteries, with graphite as both anode and cathode, eliminate the use of transition metal compounds and greatly lower the overall cost. Herein, combining the merits of the potassium ion battery and dual graphite battery, a potassium-based dual ion battery with dual-graphite electrode is developed. It delivers a reversible capacity of 62 mA h g -1 and medium discharge voltage of ≈3.96 V. The intercalation/deintercalation mechanism of K + and PF 6 - into/from graphite is proposed and discussed in detail, with various characterizations to support. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Gas cluster ion beam surface treatments for reducing field emission and breakdown of electrodes and SRF cavities

NASA Astrophysics Data System (ADS)

Swenson, D. R.; Wu, A. T.; Degenkolb, E.; Insepov, Z.

2007-08-01

Sub-micron-scale surface roughness and contamination cause field emission that can lead to high-voltage breakdown of electrodes, and these are limiting factors in the development of high gradient RF technology. We are studying various Gas Cluster Ion Beam (GCIB) treatments to smooth, clean, etch and/or chemically alter electrode surfaces to allow higher fields and accelerating gradients, and to reduce the time and cost of conditioning high-voltage electrodes. For this paper, we have processed Nb, stainless steel and Ti electrode materials using beams of Ar, O2, or NF3 + O2 clusters with accelerating potentials up to 35 kV. Using a scanning field emission microscope (SFEM), we have repeatedly seen a dramatic reduction in the number of field emission sites on Nb coupons treated with GCIB. Smoothing effects on stainless steel and Ti substrates, evaluated using SEM and AFM imaging, show that 200-nm-wide polishing scratch marks are greatly attenuated. A 150-mm diameter GCIB-treated stainless steel electrode has shown virtually no DC field emission current at gradients over 20 MV/m.

Fabrication of Out-of-Plane Electrodes for ACEO Pumps

NASA Astrophysics Data System (ADS)

Senousy, Yehya; Harnett, Cindy

2012-02-01

This abstract reports the fabrication process of a novel AC Electrosmosis (ACEO) pump with out of plane asymmetric interdigitated electrodes. A self-folding technique is used to fabricate the electrodes, that depends on the strain mismatch between the tensile stressed film (metal layer) and the compressive stress film (oxidized silicon layer). The electrodes roll up with a well-defined radius of curvature in the range of 100-200 microns. Two different electrical signals are connected to alternating electrodes using an insulating silicon nitride barrier that allows circuits to cross over each other without shorting. Electroosmotic micropumps are essential for low-cost, power-efficient microfluidic lab-on-chip devices used in diverse application such as analytical probes, drug delivery systems and surgical tools. ACEO pumps have been developed to address the drawbacks of the DCEO pumps such as the faradic reaction and gas bubbles. The original ACEO microfluidic pump was created with planar arrays of asymmetric interdigitated electrodes at the bottom of the channel. This rolled-up tube design improves on the planar design by including the channel walls and ceiling in the active pumping surface area of the device.

Numerical modelling of needle-grid electrodes for negative surface corona charging system

NASA Astrophysics Data System (ADS)

Zhuang, Y.; Chen, G.; Rotaru, M.

2011-08-01

Surface potential decay measurement is a simple and low cost tool to examine electrical properties of insulation materials. During the corona charging stage, a needle-grid electrodes system is often used to achieve uniform charge distribution on the surface of the sample. In this paper, a model using COMSOL Multiphysics has been developed to simulate the gas discharge. A well-known hydrodynamic drift-diffusion model was used. The model consists of a set of continuity equations accounting for the movement, generation and loss of charge carriers (electrons, positive and negative ions) coupled with Poisson's equation to take into account the effect of space and surface charges on the electric field. Four models with the grid electrode in different positions and several mesh sizes are compared with a model that only has the needle electrode. The results for impulse current and surface charge density on the sample clearly show the effect of the extra grid electrode with various positions.

Determination of the wine preservative sulphur dioxide with cyclic voltammetry using inkjet printed electrodes.

PubMed

Schneider, Marion; Türke, Alexander; Fischer, Wolf-Joachim; Kilmartin, Paul A

2014-09-15

During winemaking sulphur dioxide is added to prevent undesirable reactions. However, concerns over the harmful effects of sulphites have led to legal limits being placed upon such additives. There is thus a need for simple and selective determinations of sulphur dioxide in wine, especially during winemaking. The simultaneous detection of polyphenols and sulphur dioxide, using cyclic voltammetry at inert electrodes is challenging due to close oxidation potentials. In the present study, inkjet printed electrodes were developed with a suitable voltammetric signal on which the polyphenol oxidation is suppressed and the oxidation peak height for sulphur dioxide corresponds linearly to the concentration. Different types of working electrodes were printed. Electrodes consisting of gold nanoparticles mixed with silver showed the highest sensitivity towards sulphur dioxide. Low cost production of the sensor elements and ultra fast determination of sulphur dioxide by cyclic voltammetry makes this technique very promising for the wine industry. Copyright © 2014 Elsevier Ltd. All rights reserved.

Increasing the endurance of electrodes of heating salt tanks

NASA Astrophysics Data System (ADS)

Kulikov, A. I.

1997-05-01

Electrodes used for heating, melting, and sustaining the requisite temperature regime in salt tanks for heat treatment of metals and alloys operate under severe conditions (heating to 1300°C, aggressive medium of the melts of salts of alkali and alkali-earth metals). This causes early failure of the electrodes, and the heat treatment unit is stopped for repair. For example, the design service life of electrodes for SVS 2.3/13I tanks is two months, but as a rule it does not exceed one month of continuous operation. The replacement of conventional low-carbon electrode steel (for example, of grade 10) by a more expensive heat- and corrosion-resistant steel has not proved effective but rather increased the cost of the electrodes and hence the cost of the produced parts. In this connection, it is interesting to get acquainted with works devoted to increasing the service life of salt-tank electrodes for heat treatment shops of machine-building and tool plants. The present paper describes such an attempt.

Recent Progress in Iron-Based Electrode Materials for Grid-Scale Sodium-Ion Batteries.

PubMed

Fang, Yongjin; Chen, Zhongxue; Xiao, Lifen; Ai, Xinping; Cao, Yuliang; Yang, Hanxi

2018-03-01

Grid-scale energy storage batteries with electrode materials made from low-cost, earth-abundant elements are needed to meet the requirements of sustainable energy systems. Sodium-ion batteries (SIBs) with iron-based electrodes offer an attractive combination of low cost, plentiful structural diversity and high stability, making them ideal candidates for grid-scale energy storage systems. Although various iron-based cathode and anode materials have been synthesized and evaluated for sodium storage, further improvements are still required in terms of energy/power density and long cyclic stability for commercialization. In this Review, progress in iron-based electrode materials for SIBs, including oxides, polyanions, ferrocyanides, and sulfides, is briefly summarized. In addition, the reaction mechanisms, electrochemical performance enhancements, structure-composition-performance relationships, merits and drawbacks of iron-based electrode materials for SIBs are discussed. Such iron-based electrode materials will be competitive and attractive electrodes for next-generation energy storage devices. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

3D Printed Dry EEG Electrodes

PubMed Central

Krachunov, Sammy; Casson, Alexander J.

2016-01-01

Electroencephalography (EEG) is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI). A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise. PMID:27706094

3D Printed Dry EEG Electrodes.

PubMed

Krachunov, Sammy; Casson, Alexander J

2016-10-02

Electroencephalography (EEG) is a procedure that records brain activity in a non-invasive manner. The cost and size of EEG devices has decreased in recent years, facilitating a growing interest in wearable EEG that can be used out-of-the-lab for a wide range of applications, from epilepsy diagnosis, to stroke rehabilitation, to Brain-Computer Interfaces (BCI). A major obstacle for these emerging applications is the wet electrodes, which are used as part of the EEG setup. These electrodes are attached to the human scalp using a conductive gel, which can be uncomfortable to the subject, causes skin irritation, and some gels have poor long-term stability. A solution to this problem is to use dry electrodes, which do not require conductive gel, but tend to have a higher noise floor. This paper presents a novel methodology for the design and manufacture of such dry electrodes. We manufacture the electrodes using low cost desktop 3D printers and off-the-shelf components for the first time. This allows quick and inexpensive electrode manufacturing and opens the possibility of creating electrodes that are customized for each individual user. Our 3D printed electrodes are compared against standard wet electrodes, and the performance of the proposed electrodes is suitable for BCI applications, despite the presence of additional noise.

The Li-ion rechargeable battery: a perspective.

PubMed

Goodenough, John B; Park, Kyu-Sung

2013-01-30

Each cell of a battery stores electrical energy as chemical energy in two electrodes, a reductant (anode) and an oxidant (cathode), separated by an electrolyte that transfers the ionic component of the chemical reaction inside the cell and forces the electronic component outside the battery. The output on discharge is an external electronic current I at a voltage V for a time Δt. The chemical reaction of a rechargeable battery must be reversible on the application of a charging I and V. Critical parameters of a rechargeable battery are safety, density of energy that can be stored at a specific power input and retrieved at a specific power output, cycle and shelf life, storage efficiency, and cost of fabrication. Conventional ambient-temperature rechargeable batteries have solid electrodes and a liquid electrolyte. The positive electrode (cathode) consists of a host framework into which the mobile (working) cation is inserted reversibly over a finite solid-solution range. The solid-solution range, which is reduced at higher current by the rate of transfer of the working ion across electrode/electrolyte interfaces and within a host, limits the amount of charge per electrode formula unit that can be transferred over the time Δt = Δt(I). Moreover, the difference between energies of the LUMO and the HOMO of the electrolyte, i.e., electrolyte window, determines the maximum voltage for a long shelf and cycle life. The maximum stable voltage with an aqueous electrolyte is 1.5 V; the Li-ion rechargeable battery uses an organic electrolyte with a larger window, which increase the density of stored energy for a given Δt. Anode or cathode electrochemical potentials outside the electrolyte window can increase V, but they require formation of a passivating surface layer that must be permeable to Li(+) and capable of adapting rapidly to the changing electrode surface area as the electrode changes volume during cycling. A passivating surface layer adds to the impedance of the Li(+) transfer across the electrode/electrolyte interface and lowers the cycle life of a battery cell. Moreover, formation of a passivation layer on the anode robs Li from the cathode irreversibly on an initial charge, further lowering the reversible Δt. These problems plus the cost of quality control of manufacturing plague development of Li-ion rechargeable batteries that can compete with the internal combustion engine for powering electric cars and that can provide the needed low-cost storage of electrical energy generated by renewable wind and/or solar energy. Chemists are contributing to incremental improvements of the conventional strategy by investigating and controlling electrode passivation layers, improving the rate of Li(+) transfer across electrode/electrolyte interfaces, identifying electrolytes with larger windows while retaining a Li(+) conductivity σ(Li) > 10(-3) S cm(-1), synthesizing electrode morphologies that reduce the size of the active particles while pinning them on current collectors of large surface area accessible by the electrolyte, lowering the cost of cell fabrication, designing displacement-reaction anodes of higher capacity that allow a safe, fast charge, and designing alternative cathode hosts. However, new strategies are needed for batteries that go beyond powering hand-held devices, such as using electrode hosts with two-electron redox centers; replacing the cathode hosts by materials that undergo displacement reactions (e.g. sulfur) by liquid cathodes that may contain flow-through redox molecules, or by catalysts for air cathodes; and developing a Li(+) solid electrolyte separator membrane that allows an organic and aqueous liquid electrolyte on the anode and cathode sides, respectively. Opportunities exist for the chemist to bring together oxide and polymer or graphene chemistry in imaginative morphologies.

Development works on nickel/hydrogen cells. [for satellite energy storage

NASA Technical Reports Server (NTRS)

Gutmann, G.

1982-01-01

Experiments were performed to reduce the costs for NI/H2 cells by using nickel oxide electrodes with high capacity per unit area. No maintenance requirements, long cycle life, insensitivity to overcharge and cell reversal, and high power capability were revealed.

Novel flame synthesis of nanostructured α-Fe2O3 electrode as high-performance anode for lithium ion batteries

NASA Astrophysics Data System (ADS)

Wang, Yang; Roller, Justin; Maric, Radenka

2018-02-01

Nanostructured electrodes have significant potential for enhancing the kinetics of lithium storage in secondary batteries. A simple and economical manufacturing approach of these electrodes is crucial to the development and application of the next generation lithium ion (Li-ion) batteries. In this study, nanostructured α-Fe2O3 electrode is fabricated by a novel one-step flame combustion synthesis method, namely Reactive Spray Deposition Technology (RSDT). This process possesses the merits of simplicity and low cost. The structure and morphology of the electrode are investigated with X-ray diffraction, scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Electrochemical performance of the nanostructured α-Fe2O3 electrodes as the anodes for Li-ion batteries is evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy in coin-type half-cells. The as-prepared electrodes demonstrate superior cyclic performance at high current rate, which delivers a high reversible capacity of 1239.2 mAh g-1 at 1 C after 500 cycles. In addition, a discharge capacity of 513.3 mAh g-1 can be achieved at 10 C.

Towards High-Performance Aqueous Sodium-Ion Batteries: Stabilizing the Solid/Liquid Interface for NASICON-Type Na2 VTi(PO4 )3 using Concentrated Electrolytes.

PubMed

Zhang, Huang; Jeong, Sangsik; Qin, Bingsheng; Vieira Carvalho, Diogo; Buchholz, Daniel; Passerini, Stefano

2018-04-25

Aqueous Na-ion batteries may offer a solution to the cost and safety issues of high-energy batteries. However, substantial challenges remain in the development of electrode materials and electrolytes enabling high performance and long cycle life. Herein, we report the characterization of a symmetric Na-ion battery with a NASICON-type Na 2 VTi(PO 4 ) 3 electrode material in conventional aqueous and "water-in-salt" electrolytes. Extremely stable cycling performance for 1000 cycles at a high rate (20 C) is found with the highly concentrated aqueous electrolytes owing to the formation of a resistive but protective interphase between the electrode and electrolyte. These results provide important insight for the development of aqueous Na-ion batteries with stable long-term cycling performance for large-scale energy storage. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Rapid and ultrasensitive flexible palladium nano-thin film biosensing electrode development for cancer antigen HER2 detection

NASA Astrophysics Data System (ADS)

Huang, Yun-Tzu; Chang, Chia-Yu; Chen, Wei; Su, Chien-Hao; Hsu, Guo-Cheng; Chang, Chia-Ching

HER2 (human epidermal growth factor receptor 2) is one of the significant surface antigens of breast cancer Trace amount of HER2 protein in human serum is highly correlated to the tumor progression in breast cancers especially in the cases of recurrence. Therefore, HER2 detection of human serum is significant for early detection of cancer recurrence. Conventional HER2 detection approaches may not be sensitive enough or contain highly false positive rate or time consuming for accurate detection. Therefore, a rapid, highly sensitive and specific sensing is highly desired. By using HER2 specific binding peptide functionalized palladium thin film electrochemical electrode the HER2 protein concentration can be determined at sub-nanogram level by electrochemical impedance spectroscopy (EIS) within 10 mins. The Pd nano-film is sputtered on the flexible plastics substrate and reduces the cost of this electrode. Due to the low cost of the electrode, it is designed as a disposable biosensing probe which may reduce the concern of human sample contamination. The self-management after breast cancer operation may be feasible in the near future. Keywords: Electrochemical impedance spectroscopy(EIS), breast cancer, biosensor Corresponding author: ccchang01@faculty.nctu.edu.tw; Cheeshin Technology Co. Collaboration.

Computational tissue volume reconstruction of a peripheral nerve using high-resolution light-microscopy and reconstruct.

PubMed

Gierthmuehlen, Mortimer; Freiman, Thomas M; Haastert-Talini, Kirsten; Mueller, Alexandra; Kaminsky, Jan; Stieglitz, Thomas; Plachta, Dennis T T

2013-01-01

The development of neural cuff-electrodes requires several in vivo studies and revisions of the electrode design before the electrode is completely adapted to its target nerve. It is therefore favorable to simulate many of the steps involved in this process to reduce costs and animal testing. As the restoration of motor function is one of the most interesting applications of cuff-electrodes, the position and trajectories of myelinated fibers in the simulated nerve are important. In this paper, we investigate a method for building a precise neuroanatomical model of myelinated fibers in a peripheral nerve based on images obtained using high-resolution light microscopy. This anatomical model describes the first aim of our "Virtual workbench" project to establish a method for creating realistic neural simulation models based on image datasets. The imaging, processing, segmentation and technical limitations are described, and the steps involved in the transition into a simulation model are presented. The results showed that the position and trajectories of the myelinated axons were traced and virtualized using our technique, and small nerves could be reliably modeled based on of light microscopy images using low-cost OpenSource software and standard hardware. The anatomical model will be released to the scientific community.

Computational Tissue Volume Reconstruction of a Peripheral Nerve Using High-Resolution Light-Microscopy and Reconstruct

PubMed Central

Gierthmuehlen, Mortimer; Freiman, Thomas M.; Haastert-Talini, Kirsten; Mueller, Alexandra; Kaminsky, Jan; Stieglitz, Thomas; Plachta, Dennis T. T.

2013-01-01

The development of neural cuff-electrodes requires several in vivo studies and revisions of the electrode design before the electrode is completely adapted to its target nerve. It is therefore favorable to simulate many of the steps involved in this process to reduce costs and animal testing. As the restoration of motor function is one of the most interesting applications of cuff-electrodes, the position and trajectories of myelinated fibers in the simulated nerve are important. In this paper, we investigate a method for building a precise neuroanatomical model of myelinated fibers in a peripheral nerve based on images obtained using high-resolution light microscopy. This anatomical model describes the first aim of our “Virtual workbench” project to establish a method for creating realistic neural simulation models based on image datasets. The imaging, processing, segmentation and technical limitations are described, and the steps involved in the transition into a simulation model are presented. The results showed that the position and trajectories of the myelinated axons were traced and virtualized using our technique, and small nerves could be reliably modeled based on of light microscopy images using low-cost OpenSource software and standard hardware. The anatomical model will be released to the scientific community. PMID:23785485

High surface area bio-waste based carbon as a superior electrode for vanadium redox flow battery

NASA Astrophysics Data System (ADS)

Maharjan, Makhan; Bhattarai, Arjun; Ulaganathan, Mani; Wai, Nyunt; Oo, Moe Ohnmar; Wang, Jing-Yuan; Lim, Tuti Mariana

2017-09-01

Activated carbon (AC) with high surface area (1901 m2 g-1) is synthesized from low cost bio-waste orange (Citrus sinensis) peel for vanadium redox flow battery (VRB). The composition, structure and electrochemical properties of orange peel derived AC (OP-AC) are characterized by elemental analyzer, field emission-scanning electron microscopy, X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, cyclic voltammetry (CV), and electrochemical impedance spectroscopy. CV results show that OP-AC coated bipolar plate demonstrates improved electro-catalytic activity in both positive and negative side redox couples than the pristine bipolar plate electrode and this is ascribed to the high surface area of OP-AC which provides effective electrode area and better contact between the porous electrode and bipolar plate. Consequently, the performance of VRB in a static cell shows higher energy efficiency for OP-AC electrode than the pristine electrode at all current densities tested. The results suggest the OP-AC to be a promising electrode for VRB applications and can be incorporated into making conducting plastics electrode to lower the VRB cell stack weight and cost.

Component-cost and performance based comparison of flow and static batteries

NASA Astrophysics Data System (ADS)

Hopkins, Brandon J.; Smith, Kyle C.; Slocum, Alexander H.; Chiang, Yet-Ming

2015-10-01

Flow batteries are a promising grid-storage technology that is scalable, inherently flexible in power/energy ratio, and potentially low cost in comparison to conventional or ;static; battery architectures. Recent advances in flow chemistries are enabling significantly higher energy density flow electrodes. When the same battery chemistry can arguably be used in either a flow or static electrode design, the relative merits of either design choice become of interest. Here, we analyze the costs of the electrochemically active stack for both architectures under the constraint of constant energy efficiency and charge and discharge rates, using as case studies the aqueous vanadium-redox chemistry, widely used in conventional flow batteries, and aqueous lithium-iron-phosphate (LFP)/lithium-titanium-phosphate (LTP) suspensions, an example of a higher energy density suspension-based electrode. It is found that although flow batteries always have a cost advantage (kWh-1) at the stack level modeled, the advantage is a strong function of flow electrode energy density. For the LFP/LTP case, the cost advantages decreases from ∼50% to ∼10% over experimentally reasonable ranges of suspension loading. Such results are important input for design choices when both battery architectures are viable options.

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications.

PubMed

Tucker, Michael C; Phillips, Adam; Weber, Adam Z

2015-12-07

An all-iron redox flow battery is proposed and developed for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. The design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe2 (SO4 )3 active material and 1.2 m NaCl supporting electrolyte. With these materials, an average power density around 20 mW cm(-2) and a maximum energy density of 11.5 Wh L(-1) are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh(-1) , or only US$0.034 per mobile phone charge. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

All-Iron Redox Flow Battery Tailored for Off-Grid Portable Applications

DOE PAGES

Tucker, Michael C.; Phillips, Adam; Weber, Adam Z.

2015-11-20

We proposed and developed an all-iron redox flow battery for end users without access to an electricity grid. The concept is a low-cost battery which the user assembles, discharges, and then disposes of the active materials. Our design goals are: (1) minimize upfront cost, (2) maximize discharge energy, and (3) utilize non-toxic and environmentally benign materials. These are different goals than typically considered for electrochemical battery technology, which provides the opportunity for a novel solution. The selected materials are: low-carbon-steel negative electrode, paper separator, porous-carbon-paper positive electrode, and electrolyte solution containing 0.5 m Fe 2 (SO 4 ) 3 activemore » material and 1.2 m NaCl supporting electrolyte. Furthermore, with these materials, an average power density around 20 mW cm -2 and a maximum energy density of 11.5 Wh L -1 are achieved. A simple cost model indicates the consumable materials cost US$6.45 per kWh -1 , or only US$0.034 per mobile phone charge.« less

In situ prepared transparent polyaniline electrode and its application in bifacial dye-sensitized solar cells.

PubMed

Tai, Qidong; Chen, Bolei; Guo, Feng; Xu, Sheng; Hu, Hao; Sebo, Bobby; Zhao, Xing-Zhong

2011-05-24

Highly uniform and transparent polyaniline (PANI) electrodes that can be used as counter electrodes in dye-sensitized solar cells (DSSCs) were prepared by a facile in situ polymerization method. They were used to fabricate a novel bifacially active transparent DSSC, which showed conversion efficiencies of 6.54 and 4.26% corresponding to front- and rear-side illumination, respectively. Meanwhile, the efficiency of the same photoanode employing a Pt counter electrode was 6.69%. Compared to conventional Pt-based DSSCs, the design of the bifacial DSSC fabricated in this work would help to bring down the cost of energy production due to the lower cost of the materials and the higher power-generating efficiency of such devices for their capabilities of utilizing the light from both sides. These promising results highlight the potential application of PANI in cost-effective, transparent DSSCs.

Graphene oxide - Polyvinyl alcohol nanocomposite based electrode material for supercapacitors

NASA Astrophysics Data System (ADS)

Pawar, Pranav Bhagwan; Shukla, Shobha; Saxena, Sumit

2016-07-01

Supercapacitors are high capacitive energy storage devices and find applications where rapid bursts of power are required. Thus materials offering high specific capacitance are of fundamental interest in development of these electrochemical devices. Graphene oxide based nanocomposites are mechanically robust and have interesting electronic properties. These form potential electrode materials efficient for charge storage in supercapacitors. In this perspective, we investigate low cost graphene oxide based nanocomposites as electrode material for supercapacitor. Nanocomposites of graphene oxide and polyvinyl alcohol were synthesized in solution phase by integrating graphene oxide as filler in polyvinyl alcohol matrix. Structural and optical characterizations suggest the formation of graphene oxide and polyvinyl alcohol nanocomposites. These nanocomposites were found to have high specific capacitance, were cyclable, ecofriendly and economical. Our studies suggest that nanocomposites prepared by adding 0.5% wt/wt of graphene oxide in polyvinyl alcohol can be used an efficient electrode material for supercapacitors.

A lithium ion battery using an aqueous electrolyte solution

PubMed Central

Chang, Zheng; Li, Chunyang; Wang, Yanfang; Chen, Bingwei; Fu, Lijun; Zhu, Yusong; Zhang, Lixin; Wu, Yuping; Huang, Wei

2016-01-01

Energy and environmental pollution have become the two major problems in today’s society. The development of green energy storage devices with good safety, high reliability, high energy density and low cost are urgently demanded. Here we report on a lithium ion battery using an aqueous electrolyte solution. It is built up by using graphite coated with gel polymer membrane and LISICON as the negative electrode, and LiFePO4 in aqueous solution as the positive electrode. Its average discharge voltage is up to 3.1 V and energy density based on the two electrode materials is 258 Wh kg−1. It will be a promising energy storage system with good safety and efficient cooling effects. PMID:27328707

High-performance Ti/Sb-SnO(2)/Pb(3)O(4) electrodes for chlorine evolution: preparation and characteristics.

PubMed

Shao, Dan; Yan, Wei; Cao, Lu; Li, Xiaoliang; Xu, Hao

2014-02-28

Chlorine evolution via electrochemical approach has wide application prospects in drinking water disinfection and wastewater treatment fields. Dimensional stable anodes used for chlorine evolution should have high stability and adequate chlorine evolution efficiency. Thus a novel and cost-effective Ti/Sb-SnO(2)/Pb(3)O(4)electrode was developed. The physicochemical and electrochemical properties as well as the chlorine evolution performances of the electrodes were investigated. The electrocatalytic activity and deactivation course of the electrodes were also explored. Results showed that this novel electrode had strong chlorine evolution ability with high current efficiency ranging from 87.3% to 93.4% depending on the operational conditions. The accelerated service life of Ti/Sb-SnO(2)/Pb(3)O(4) electrode could reach 180 h at a current density of 10,000 A m(-2) in 0.5 molL(-1) H(2)SO(4). During the electrolysis process, it was found that the conversion of Pb(3)O(4) into β-PbO(2) happened gradually on the electrode surface, which not only inhibited the leakage of hazardous Pb(2+) ion but also increased the anti-corrosion capacity of the electrode effectively. Copyright © 2014 Elsevier B.V. All rights reserved.

A top-down approach for fabricating free-standing bio-carbon supercapacitor electrodes with a hierarchical structure.

PubMed

Li, Yingzhi; Zhang, Qinghua; Zhang, Junxian; Jin, Lei; Zhao, Xin; Xu, Ting

2015-09-23

Biomass has delicate hierarchical structures, which inspired us to develop a cost-effective route to prepare electrode materials with rational nanostructures for use in high-performance storage devices. Here, we demonstrate a novel top-down approach for fabricating bio-carbon materials with stable structures and excellent diffusion pathways; this approach is based on carbonization with controlled chemical activation. The developed free-standing bio-carbon electrode exhibits a high specific capacitance of 204 F g(-1) at 1 A g(-1); good rate capability, as indicated by the residual initial capacitance of 85.5% at 10 A g(-1); and a long cycle life. These performance characteristics are attributed to the outstanding hierarchical structures of the electrode material. Appropriate carbonization conditions enable the bio-carbon materials to inherit the inherent hierarchical texture of the original biomass, thereby facilitating effective channels for fast ion transfer. The macropores and mesopores that result from chemical activation significantly increase the specific surface area and also play the role of temporary ion-buffering reservoirs, further shortening the ionic diffusion distance.

Challenges in Improving Cochlear Implant Performance and Accessibility.

PubMed

Zeng, Fan-Gang

2017-08-01

Here I identify two gaps in cochlear implants that have been limiting their performance and acceptance. First, cochlear implant performance has remained largely unchanged, despite the number of publications tripling per decade in the last 30 years. Little has been done so far to address a fundamental limitation in the electrode-to-neuron interface, with the electrode size being a thousand times larger than the neuron diameter while the number of electrodes being a thousand times less. Both the small number and the large size of electrodes produce broad spatial activation and poor frequency resolution that limit current cochlear implant performance. Second, a similarly rapid growth in cochlear implant volume has not produced an expected decrease in unit price in the same period. The high cost contributes to low market penetration rate, which is about 20% in developed countries and less than 1% in developing countries. I will discuss changes needed in both research strategy and business practice to close the gap between prosthetic and normal hearing as well as that between haves and have-nots.

Critical Research for Cost-Effective Photoelectrochemical Production of Hydrogen

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xu, Liwei; Deng, Xunming; Abken, Anka

2014-10-29

The objective of this project is to develop critical technologies required for cost-effective production of hydrogen from sunlight and water using a-Si triple junction solar cell based photo-electrodes. In this project, Midwest Optoelectronics, LLC (MWOE) and its collaborating organizations utilize triple junction a-Si thin film solar cells as the core element to fabricate photoelectrochemical (PEC) cells. Triple junction a-Si/a-SiGe/a-SiGe solar cell is an ideal material for making cost-effective PEC system which uses sun light to split water and generate hydrogen. It has the following key features: 1) It has an open circuit voltage (Voc ) of ~ 2.3V and hasmore » an operating voltage around 1.6V. This is ideal for water splitting. There is no need to add a bias voltage or to inter-connect more than one solar cell. 2) It is made by depositing a-Si/a-SiGe/aSi-Ge thin films on a conducting stainless steel substrate which can serve as an electrode. When we immerse the triple junction solar cells in an electrolyte and illuminate it under sunlight, the voltage is large enough to split the water, generating oxygen at the Si solar cell side (for SS/n-i-p/sunlight structure) and hydrogen at the back, which is stainless steel side. There is no need to use a counter electrode or to make any wire connection. 3) It is being produced in large rolls of 3ft wide and up to 5000 ft long stainless steel web in a 25MW roll-to-roll production machine. Therefore it can be produced at a very low cost. After several years of research with many different kinds of material, we have developed promising transparent, conducting and corrosion resistant (TCCR) coating material; we carried out extensive research on oxygen and hydrogen generation catalysts, developed methods to make PEC electrode from production-grade a-Si solar cells; we have designed and tested various PEC module cases and carried out extensive outdoor testing; we were able to obtain a solar to hydrogen conversion efficiency (STH) about 5.7% and a running time about 480 hrs, which are very promising results; we have also completed a techno-economic analysis of our PEC system, which indicates that a projected hydrogen generation cost of $2/gge is achievable with a 50 Ton-per-day (TPD) scale under certain conditions.« less

Low-cost and reagent-free paper-based device to detect chloride ions in serum and sweat.

PubMed

Cinti, Stefano; Fiore, Luca; Massoud, Renato; Cortese, Claudio; Moscone, Danila; Palleschi, Giuseppe; Arduini, Fabiana

2018-03-01

The recent goal of sustainability in analytical chemistry has boosted the development of eco-designed analytical tools to deliver fast and cost-effective analysis with low economic and environmental impact. Due to the recent focus in sustainability, we report the use of low-cost filter paper as a sustainable material to print silver electrodes and to load reagents for a reagent-free electrochemical detection of chloride in biological samples, namely serum and sweat. The electrochemical detection of chloride ions was carried out by exploiting the reaction of the analyte (i.e. chloride) with the silver working electrode. During the oxidation wave in cyclic voltammetry the silver ions are produced, thus they react with chloride ions to form AgCl, while in the reduction wave, the following reaction occurs: AgCl + e - -->Ag + Cl - . These reactions at the electrode surface resulted in anodic/cathodic peaks directly proportional to the chloride ions in solution. Chloride ions were detected with the addition of only 10μL of the sample on the paper-based electrochemical cell, obtaining linearity up to 200mM with a detection limit equal to 1mM and relative standard deviation lower than 10%. The accuracy of the sensor was evaluated in serum and sweat samples, with percentage recoveries between 93 ± 10 and 108 ± 8%. Moreover, the results achieved with the paper-based device were positively compared with those obtained by using the gold standard method (Ion Selective Electrode) adopted in routine clinical analyses. Copyright © 2017 Elsevier B.V. All rights reserved.

Nanocomposite electrodes for smartphone enabled healthcare garments: e-bra and smart vest

NASA Astrophysics Data System (ADS)

Kumar, Prashanth S.; Rai, Pratyush; Oh, Sechang; Kwon, Hyeokjun; Varadan, Vijay K.

2012-10-01

The financial burden of hospital readmissions and treatment of chronic cardiac diseases are global concerns. Point of Care (POC) has been presented as an elegant solution for healthcare cost reduction. However, large scale adoption of POC systems requires an intuitive, unobtrusive and easy to use health monitoring system from patient's perspective. Healthcare textiles are sensor systems mounted on textile platform that function as wearable unobtrusive health monitoring systems. Although much work has been done in the development and demonstration of textile mounted monitoring systems, material and production costs are still high. Nanomaterials based devices and technology can be employed in these healthcare textiles for improved electrical characteristics of the sensors, lowered cost due to less material consumption and compatibility to varied manufacturing techniques. Carbon nanotube composite ink based printable conductive electrodes is such a textile adaptable nanomaterial technology. Screen printed Nanocomposite electrodes made of carbon nanotubes and an acrylic polymer can be used in undergarments like vests and brassieres, for cardiac biopotential (Electrocardiography, ECG) sensing. A Bluetooth module and a smartphone can then be used to provide cyber-infrastructure connectivity for the healthcare data from these healthcare garments. They can be used to monitor young or elderly recuperating /convalescent patients either in hospital or at home, or they can be used by young athletes to monitor important physiological parameters to better design their training or fitness program. In this study, we evaluate screen printed CNT-acrylic Nanocomposite electrodes for ECG signal quality and any CNT leaching hazard that might lead to skin toxicity.

Low Cost Electrode Assembly for EEG Recordings in Mice

PubMed Central

Vogler, Emily C.; Flynn, Daniel T.; Busciglio, Federico; Bohannan, Ryan C.; Tran, Alison; Mahavongtrakul, Matthew; Busciglio, Jorge A.

2017-01-01

Wireless electroencephalography (EEG) of small animal subjects typically utilizes miniaturized EEG devices which require a robust recording and electrode assembly that remains in place while also being well-tolerated by the animal so as not to impair the ability of the animal to perform normal living activities or experimental tasks. We developed simple and fast electrode assembly and method of electrode implantation using electrode wires and wire-wrap technology that provides both higher survival and success rates in obtaining recordings from the electrodes than methods using screws as electrodes. The new wire method results in a 51% improvement in the number of electrodes that successfully record EEG signal. Also, the electrode assembly remains affixed and provides EEG signal for at least a month after implantation. Screws often serve as recording electrodes, which require either drilling holes into the skull to insert screws or affixing screws to the surface of the skull with adhesive. Drilling holes large enough to insert screws can be invasive and damaging to brain tissue, using adhesives may interfere with conductance and result in a poor signal, and soldering screws to wire leads results in fragile connections. The methods presented in this article provide a robust implant that is minimally invasive and has a significantly higher success rate of electrode implantation. In addition, the implant remains affixed and produces good recordings for over a month, while using economical, easily obtained materials and skills readily available in most animal research laboratories. PMID:29184480

Low Cost Electrode Assembly for EEG Recordings in Mice.

PubMed

Vogler, Emily C; Flynn, Daniel T; Busciglio, Federico; Bohannan, Ryan C; Tran, Alison; Mahavongtrakul, Matthew; Busciglio, Jorge A

2017-01-01

Wireless electroencephalography (EEG) of small animal subjects typically utilizes miniaturized EEG devices which require a robust recording and electrode assembly that remains in place while also being well-tolerated by the animal so as not to impair the ability of the animal to perform normal living activities or experimental tasks. We developed simple and fast electrode assembly and method of electrode implantation using electrode wires and wire-wrap technology that provides both higher survival and success rates in obtaining recordings from the electrodes than methods using screws as electrodes. The new wire method results in a 51% improvement in the number of electrodes that successfully record EEG signal. Also, the electrode assembly remains affixed and provides EEG signal for at least a month after implantation. Screws often serve as recording electrodes, which require either drilling holes into the skull to insert screws or affixing screws to the surface of the skull with adhesive. Drilling holes large enough to insert screws can be invasive and damaging to brain tissue, using adhesives may interfere with conductance and result in a poor signal, and soldering screws to wire leads results in fragile connections. The methods presented in this article provide a robust implant that is minimally invasive and has a significantly higher success rate of electrode implantation. In addition, the implant remains affixed and produces good recordings for over a month, while using economical, easily obtained materials and skills readily available in most animal research laboratories.

Centrifugal Spinning and Its Energy Storage Applications

NASA Astrophysics Data System (ADS)

Yao, Lu

Lithium-ion batteries (LIBs) and supercapacitors are important electrochemical energy storage systems. LIBs have high specific energy density, long cycle life, good thermal stability, low self-discharge, and no memory effect. However, the low abundance of Li in the Earth's crust and the rising cost of LIBs urge the attempts to develop alternative energy storage systems. Recently, sodium-ion batteries (SIBs) have become an attractive alternative to LIBs due to the high abundance and low cost of Na. Although the specific capacity and energy density of SIBs are not as high as LIBs, SIBs can still be promising power sources for certain applications such as large-scale, stationary grids. Supercapacitors are another important class of energy storage devices. Electric double-layer capacitors (EDLCs) are one important type of supercapacitors and they exhibit high power density, long cycle life, excellent rate capability and environmental friendliness. The potential applications of supercapacitors include memory protection in electronic circuitry, consumer portable electronic devices, and electrical hybrid vehicles. The electrochemical performance of SIBs and EDLCs is largely dependent on the electrode materials. Therefore, development of superior electrodes is the key to achieve highperformance alternative energy storage systems. Recently, one-dimensional nano-/micro-fiber based electrodes have become promising candidates in energy storage because they possess a variety of desirable properties including large specific surface area, well-guided ionic/electronic transport, and good electrode-electrolyte contact, which contribute to enhanced electrochemical performance. Currently, most nano-/micro-fiber based electrodes are prepared via electrospinning method. However, the low production rate of this approach hinders its practical application in the production of fibrous electrodes. Thus, it is significantly important to employ a rapid, low-cost and scalable nano-/micro-fiber production method to substitute electrospinning in industrial production. Recently, centrifugal spinning has gained researchers' attention. The centrifugal spinning method avoids the use of high voltage supply and can work with concentrated solutions, and most importantly, it can increase the production rate of nano-/micro-fibers to at least two orders or magnitude higher than that of electrospinning. This novel fiber fabrication approach is mostly used in tissue engineering field, and it can be potentially applied in preparing electrodes for SIBs and EDLCs. In the present work, we firstly study the influence of solution intrinsic properties and operational parameters using polyacrylonitrile as an example, and establish the processing-structure relationships for this spinning technique. We then use this novel spinning method to prepare porous carbon nanofibers (PCNFs), SnO2 microfibers and lithium-substituted sodium layered transition metal oxide fibers and use them as electrodes for EDLCs and SIBs. The as-prepared PCNFs, SnO2 microfibers and lithiumsubstituted sodium layered transition metal oxide fibers exhibit good electrochemical performance. It is therefore demonstrated that centrifugal spinning can be a promising nano- /micro-fiber preparation approach for mass production of electrode materials used in energy storage applications.

Assembly of a Cost-Effective Anode Using Palladium Nanoparticles for Alkaline Fuel Cell Applications

ERIC Educational Resources Information Center

Feliciano-Ramos, Ileana; Casan~as-Montes, Barbara; García-Maldonado, María M.; Menendez, Christian L.; Mayol, Ana R.; Díaz-Vazquez, Liz M.; Cabrera, Carlos R.

2015-01-01

Nanotechnology allows the synthesis of nanoscale catalysts, which offer an efficient alternative for fuel cell applications. In this laboratory experiment, the student selects a cost-effective anode for fuel cells by comparing three different working electrodes. These are commercially available palladium (Pd) and glassy carbon (GC) electrodes, and…

Development of a simple, low cost chronoamperometric assay for fructose based on a commercial graphite-nanoparticle modified screen-printed carbon electrode.

PubMed

Nicholas, Phil; Pittson, Robin; Hart, John P

2018-02-15

This paper describes the development of a simple, low cost chronoamperometric assay, for the measurement of fructose, using a graphite-nanoparticle modified screen-printed electrode (SPCE-G-COOH). Cyclic voltammetry showed that the response of the SPCE-G-COOH enhanced the sensitivity and precision, towards the enzymatically generated ferrocyanide species, over a plain SPCE; therefore the former was employed in subsequent studies. Calibration studies were carried out using chronoamperometry with a 40µl mixture containing fructose, mediator and FDH, deposited onto the SPCE-G-COOH. The response was linear from 0.1mM to 1.0mM. A commercial fruit juice sample was analysed using the developed assay and the fructose concentration was calculated to be 477mM with a precision of 3.03% (n=5). Following fortification (477mM fructose) the mean recovery was found to be 97.12% with a coefficient of variation of 6.42% (n=5); consequently, the method holds promise for the analysis of commercial fruit juices. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional design of electrolytic biosensor

NASA Astrophysics Data System (ADS)

Gamage Preethichandra, D. M.; Mala Ekanayake, E. M. I.; Onoda, M.

2017-11-01

A novel amperometric biosensbased on conjugated polypyrrole (PPy) deposited on a Pt modified ITO (indium tin oxide) conductive glass substrate and their performances are described. We have presented a method of developing a highly sensitive and low-cost nano-biosensor for blood glucose measurements. The fabrication method proposed decreases the cost of production significantly as the amount of noble metals used is minimized. A nano-corrugated PPy substrate was developed through pulsed electrochemical deposition. The sensitivity achieved was 325 mA/(Mcm2) and the linear range of the developed sensor was 50-60 mmol/l. Then the application of the electrophoresis helps the glucose oxidase (GOx) on the PPy substrate. The main reason behind this high enzyme loading is the high electric field applied across the sensor surface (working electrode) and the counter electrode where that pushes the nano-scale enzyme particles floating in the phosphate buffer solution towards the substrate. The novel technique used has provided an extremely high sensitivities and very high linear ranges for enzyme (GOx) and therefore can be concluded that this is a very good technique to load enzyme onto the conducting polymer substrates.

Segmented AC-coupled readout from continuous collection electrodes in semiconductor sensors

DOEpatents

Sadrozinski, Hartmut F. W.; Seiden, Abraham; Cartiglia, Nicolo

2017-04-04

Position sensitive radiation detection is provided using a continuous electrode in a semiconductor radiation detector, as opposed to the conventional use of a segmented electrode. Time constants relating to AC coupling between the continuous electrode and segmented contacts to the electrode are selected to provide position resolution from the resulting configurations. The resulting detectors advantageously have a more uniform electric field than conventional detectors having segmented electrodes, and are expected to have much lower cost of production and of integration with readout electronics.

CHROMIUM ELECTROANALYSIS AT SCREEN PRINTED ELECTRODE MODIFIED BY THIN FILMS OF NICKEL

EPA Science Inventory

A rapid and potentially cost-effective electrochemical method is reported for analysis of chromium (VI) and Chromium(III) using a nickel modified screen printed carbon ink electrode. Electrochemical characteristics of nickel modified electrode as well voltammetric behavior f...

High-Performance Flexible Transparent Electrode with an Embedded Metal Mesh Fabricated by Cost-Effective Solution Process.

PubMed

Khan, Arshad; Lee, Sangeon; Jang, Taehee; Xiong, Ze; Zhang, Cuiping; Tang, Jinyao; Guo, L Jay; Li, Wen-Di

2016-06-01

A new structure of flexible transparent electrodes is reported, featuring a metal mesh fully embedded and mechanically anchored in a flexible substrate, and a cost-effective solution-based fabrication strategy for this new transparent electrode. The embedded nature of the metal-mesh electrodes provides a series of advantages, including surface smoothness that is crucial for device fabrication, mechanical stability under high bending stress, strong adhesion to the substrate with excellent flexibility, and favorable resistance against moisture, oxygen, and chemicals. The novel fabrication process replaces vacuum-based metal deposition with an electrodeposition process and is potentially suitable for high-throughput, large-volume, and low-cost production. In particular, this strategy enables fabrication of a high-aspect-ratio (thickness to linewidth) metal mesh, substantially improving conductivity without considerably sacrificing transparency. Various prototype flexible transparent electrodes are demonstrated with transmittance higher than 90% and sheet resistance below 1 ohm sq(-1) , as well as extremely high figures of merit up to 1.5 × 10(4) , which are among the highest reported values in recent studies. Finally using our embedded metal-mesh electrode, a flexible transparent thin-film heater is demonstrated with a low power density requirement, rapid response time, and a low operating voltage. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

X-ray Absorption Spectroscopy Characterization of Electrochemical Processes in Renewable Energy Storage and Conversion Devices

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farmand, Maryam

2013-05-19

The development of better energy conversion and storage devices, such as fuel cells and batteries, is crucial for reduction of our global carbon footprint and improving the quality of the air we breathe. However, both of these technologies face important challenges. The development of lower cost and better electrode materials, which are more durable and allow more control over the electrochemical reactions occurring at the electrode/electrolyte interface, is perhaps most important for meeting these challenges. Hence, full characterization of the electrochemical processes that occur at the electrodes is vital for intelligent design of more energy efficient electrodes. X-ray absorption spectroscopymore » (XAS) is a short-range order, element specific technique that can be utilized to probe the processes occurring at operating electrode surfaces, as well for studying the amorphous materials and nano-particles making up the electrodes. It has been increasingly used in recent years to study fuel cell catalysts through application of the and #916; and mgr; XANES technique, in combination with the more traditional X-ray Absorption Near Edge Structure (XANES) and Extended X-ray Absorption Fine Structure (EXAFS) techniques. The and #916; and mgr; XANES data analysis technique, previously developed and applied to heterogeneous catalysts and fuel cell electrocatalysts by the GWU group, was extended in this work to provide for the first time space resolved adsorbate coverages on both electrodes of a direct methanol fuel cell. Even more importantly, the and #916; and mgr; technique was applied for the first time to battery relevant materials, where bulk properties such as the oxidation state and local geometry of a cathode are followed.« less

Nonenzymetic glucose sensing using carbon functionalized carbon doped ZnO nanorod arrays

NASA Astrophysics Data System (ADS)

Chakraborty, Pinak; Majumder, Tanmoy; Dhar, Saurab; Mondal, Suvra Prakash

2018-04-01

Fabrication of highly sensitive, long stability and low cost glucose sensors are attractive for biomedical applications and food industries. Most of the commercial glucose sensors are based on enzymatic detection which suffers from problems underlying in enzyme activities. Development of high sensitive, enzyme free sensors is a great challenge for next generation glucose sensing applications. In our study Zinc oxide nanorod sensing electrodes have been grown using low cost hydrothermal route and their nonenzymatic glucose sensing properties have been demonstrated with carbon functionalized, carbon doped ZnO nanorods (C-ZnO NRs) in neutral medium (0.1M PBS, pH 7.4) using cyclic voltammetry and amperometry measurements. The C-ZnO NRs electrodes demonstrated glucose sensitivity˜ 13.66 µAmM-1cm-2 in the concentration range 0.7 - 14 mM.

Dye sensitized solar cell based on environmental friendly eosin Y dye and Al doped titanium dioxide nano particles

NASA Astrophysics Data System (ADS)

Kulkarni, Swati S.; Bodkhe, Gajanan A.; Shirsat, Sumedh M.; Hussaini, S. S.; Shejwal, N. N.; Shirsat, Mahendra D.

2018-03-01

Present communication deals with the development of cost effective dye sensitized solar cell (DSSC) with eco-friendly materials. Eco-friendly Eosin Y dye was used to sensitize photo anode which was fabricated using undoped and Aluminium doped titanium dioxide (TiO2) nanoparticles. Undoped and Aluminium doped TiO2 nanoparticles were synthesized by simple and cost effective sol-gel method. Aluminium doped and undoped TiO2 nanoparticles were characterized using UV-visible, FT-IR spectroscopy, x-ray Diffraction, and Scanning Electron Micrograph with EDX. The photo-voltaic activity of the cell was studied under light irradiation of 100 milliwatt cm-2. Aluminium doped TiO2 nanoparticle photo electrode exhibits more than 60% increase in cell efficiency as compared to the undoped TiO2 nanoparticle photo electrode.

Cheap, High-Performance, and Wearable Mn Oxide Supercapacitors with Urea-LiClO4 Based Gel Electrolytes.

PubMed

Deng, Ming-Jay; Chen, Kai-Wen; Che, Yo-Cheng; Wang, I-Ju; Lin, Chih-Ming; Chen, Jin-Ming; Lu, Kueih-Tzu; Liao, Yen-Fa; Ishii, Hirofumi

2017-01-11

Here we report a simple, scalable, and low-cost method to enhance the electrochemical properties of Mn oxide electrodes for highly efficient and flexible symmetrical supercapacitors. The method involving printing on a printer, pencil-drawing, and electrodeposition is established to fabricate Mn oxide/Ni-nanotube/graphite/paper hybrid electrodes operating with a low-cost, novel urea-LiClO 4 /PVA as gel electrolyte for flexible solid-state supercapacitor (FSSC) devices. The Mn oxide nanofiber/Ni-nanotube/graphite/paper (MNNGP) electrodes in urea-LiClO 4 /PVA gel electrolyte show specific capacitance (C sp ) 960 F/g in voltage region 0.8 V at 5 mV/s and exhibit excellent rates of capacitance retention more than 85% after 5000 cycles. Moreover, the electrochemical behavior of the MNNGP electrodes in urea-LiClO 4 /PVA at operating temperatures 27-110 °C was investigated; the results show that the MNNGP electrodes in urea-LiClO 4 /PVA exhibit outstanding performance (1100 F/g), even at 90 °C. The assembled FSSC devices based on the MNNGP electrodes in urea-LiClO 4 /PVA exhibit great C sp (380 F/g in potential region of 2.0 V at 5 mV/s, exhibiting superior energy density 211.1 W h/kg) and great cycle stability (less than 15% loss after 5000 cycles at 25 mV/s). The oxidation-state change was examined by in situ X-ray absorption spectroscopy. FSSC devices would open new opportunities in developing novel portable, wearable, and roll-up electric devices owing to the cheap, high-performance, wide range of operating temperature, and simple procedures for large-area fabrication.

Research Progress in MnO2 -Carbon Based Supercapacitor Electrode Materials.

PubMed

Zhang, Qun-Zheng; Zhang, Dian; Miao, Zong-Cheng; Zhang, Xun-Li; Chou, Shu-Lei

2018-04-30

With the serious impact of fossil fuels on the environment and the rapid development of the global economy, the development of clean and usable energy storage devices has become one of the most important themes of sustainable development in the world today. Supercapacitors are a new type of green energy storage device, with high power density, long cycle life, wide temperature range, and both economic and environmental advantages. In many industries, they have enormous application prospects. Electrode materials are an important factor affecting the performance of supercapacitors. MnO 2 -based materials are widely investigated for supercapacitors because of their high theoretical capacitance, good chemical stability, low cost, and environmental friendliness. To achieve high specific capacitance and high rate capability, the current best solution is to use MnO 2 and carbon composite materials. Herein, MnO 2 -carbon composite as supercapacitor electrode materials is reviewed including the synthesis method and research status in recent years. Finally, the challenges and future development directions of an MnO 2 -carbon based supercapacitor are summarized. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Recent Progress in the Development of Printed Thin-Film Transistors and Circuits with High-Resolution Printing Technology.

PubMed

Fukuda, Kenjiro; Someya, Takao

2017-07-01

Printed electronics enable the fabrication of large-scale, low-cost electronic devices and systems, and thus offer significant possibilities in terms of developing new electronics/optics applications in various fields. Almost all electronic applications require information processing using logic circuits. Hence, realizing the high-speed operation of logic circuits is also important for printed devices. This report summarizes recent progress in the development of printed thin-film transistors (TFTs) and integrated circuits in terms of materials, printing technologies, and applications. The first part of this report gives an overview of the development of functional inks such as semiconductors, electrodes, and dielectrics. The second part discusses high-resolution printing technologies and strategies to enable high-resolution patterning. The main focus of this report is on obtaining printed electrodes with high-resolution patterning and the electrical performance of printed TFTs using such printed electrodes. In the final part, some applications of printed electronics are introduced to exemplify their potential. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Hybrid approach combining multiple characterization techniques and simulations for microstructural analysis of proton exchange membrane fuel cell electrodes

NASA Astrophysics Data System (ADS)

Cetinbas, Firat C.; Ahluwalia, Rajesh K.; Kariuki, Nancy; De Andrade, Vincent; Fongalland, Dash; Smith, Linda; Sharman, Jonathan; Ferreira, Paulo; Rasouli, Somaye; Myers, Deborah J.

2017-03-01

The cost and performance of proton exchange membrane fuel cells strongly depend on the cathode electrode due to usage of expensive platinum (Pt) group metal catalyst and sluggish reaction kinetics. Development of low Pt content high performance cathodes requires comprehensive understanding of the electrode microstructure. In this study, a new approach is presented to characterize the detailed cathode electrode microstructure from nm to μm length scales by combining information from different experimental techniques. In this context, nano-scale X-ray computed tomography (nano-CT) is performed to extract the secondary pore space of the electrode. Transmission electron microscopy (TEM) is employed to determine primary C particle and Pt particle size distributions. X-ray scattering, with its ability to provide size distributions of orders of magnitude more particles than TEM, is used to confirm the TEM-determined size distributions. The number of primary pores that cannot be resolved by nano-CT is approximated using mercury intrusion porosimetry. An algorithm is developed to incorporate all these experimental data in one geometric representation. Upon validation of pore size distribution against gas adsorption and mercury intrusion porosimetry data, reconstructed ionomer size distribution is reported. In addition, transport related characteristics and effective properties are computed by performing simulations on the hybrid microstructure.

Nonenzymatic glucose sensor based on renewable electrospun Ni nanoparticle-loaded carbon nanofiber paste electrode.

PubMed

Liu, Yang; Teng, Hong; Hou, Haoqing; You, Tianyan

2009-07-15

A novel nonenzymatic glucose sensor was developed based on the renewable Ni nanoparticle-loaded carbon nanofiber paste (NiCFP) electrode. The NiCF nanocomposite was prepared by combination of electrospinning technique with thermal treatment method. The scanning electron microscopy (SEM) and transmission electron microscopy (TEM) images showed that large amounts of spherical nanoparticles were well dispersed on the surface or embedded in the carbon nanofibers. And the nanoparticles were composed of Ni and NiO, as revealed by energy dispersive X-ray spectroscopy (EDX) and X-ray powder diffraction (XRD). In application to nonenzymatic glucose determination, the renewable NiCFP electrodes, which were constructed by simply mixing the electrospun nanocomposite with mineral oil, exhibited strong and fast amperometric response without being poisoned by chloride ions. Low detection limit of 1 microM with wide linear range from 2 microM to 2.5 mM (R=0.9997) could be obtained. The current response of the proposed glucose sensor was highly sensitive and stable, attributing to the electrocatalytic performance of the firmly embedded Ni nanoparticles as well as the chemical inertness of the carbon-based electrode. The good analytical performance, low cost and straightforward preparation method made this novel electrode material promising for the development of effective glucose sensor.

Aqueous-Processed, High-Capacity Electrodes for Membrane Capacitive Deionization.

PubMed

Jain, Amit; Kim, Jun; Owoseni, Oluwaseye M; Weathers, Cierra; Caña, Daniel; Zuo, Kuichang; Walker, W Shane; Li, Qilin; Verduzco, Rafael

2018-05-15

Membrane capacitive deionization (MCDI) is a low-cost technology for desalination. Typically, MCDI electrodes are fabricated using a slurry of nanoparticles in an organic solvent along with polyvinylidene fluoride (PVDF) polymeric binder. Recent studies of the environmental impact of CDI have pointed to the organic solvents used in the fabrication of CDI electrodes as key contributors to the overall environmental impact of the technology. Here, we report a scalable, aqueous processing approach to prepare MCDI electrodes using water-soluble polymer poly(vinyl alcohol) (PVA) as a binder and ion-exchange polymer. Electrodes are prepared by depositing aqueous slurry of activated carbon and PVA binder followed by coating with a thin layer of PVA-based cation- or anion-exchange polymer. When coated with ion-exchange layers, the PVA-bound electrodes exhibit salt adsorption capacities up to 14.4 mg/g and charge efficiencies up to 86.3%, higher than typically achieved for activated carbon electrodes with a hydrophobic polymer binder and ion-exchange membranes (5-13 mg/g). Furthermore, when paired with low-resistance commercial ion-exchange membranes, salt adsorption capacities exceed 18 mg/g. Our overall approach demonstrates a simple, environmentally friendly, cost-effective, and scalable method for the fabrication of high-capacity MCDI electrodes.

13.2% efficiency Si nanowire/PEDOT:PSS hybrid solar cell using a transfer-imprinted Au mesh electrode

PubMed Central

Park, Kwang-Tae; Kim, Han-Jung; Park, Min-Joon; Jeong, Jun-Ho; Lee, Jihye; Choi, Dae-Geun; Lee, Jung-Ho; Choi, Jun-Hyuk

2015-01-01

In recent years, inorganic/organic hybrid solar cell concept has received growing attention for alternative energy solution because of the potential for facile and low-cost fabrication and high efficiency. Here, we report highly efficient hybrid solar cells based on silicon nanowires (SiNWs) and poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) using transfer-imprinted metal mesh front electrodes. Such a structure increases the optical absorption and shortens the carrier transport distance, thus, it greatly increases the charge carrier collection efficiency. Compared with hybrid cells formed using indium tin oxide (ITO) electrodes, we find an increase in power conversion efficiency from 5.95% to 13.2%, which is attributed to improvements in both the electrical and optical properties of the Au mesh electrode. Our fabrication strategy for metal mesh electrode is suitable for the large-scale fabrication of flexible transparent electrodes, paving the way towards low-cost, high-efficiency, flexible solar cells. PMID:26174964

Electrochemical studies on nanometal oxide-activated carbon composite electrodes for aqueous supercapacitors

NASA Astrophysics Data System (ADS)

Ho, Mui Yen; Khiew, Poi Sim; Isa, Dino; Chiu, Wee Siong

2014-11-01

In present study, the electrochemical performance of eco-friendly and cost-effective titanium oxide (TiO2)-based and zinc oxide-based nanocomposite electrodes were studied in neutral aqueous Na2SO3 electrolyte, respectively. The electrochemical properties of these composite electrodes were studied using cyclic voltammetry (CV), galvanostatic charge-discharge (CD) and electrochemical impedance spectroscopy (EIS). The experimental results reveal that these two nanocomposite electrodes achieve the highest specific capacitance at fairly low oxide loading onto activated carbon (AC) electrodes, respectively. Considerable enhancement of the electrochemical properties of TiO2/AC and ZnO/AC nanocomposite electrodes is achieved via synergistic effects contributed from the nanostructured metal oxides and the high surface area mesoporous AC. Cations and anions from metal oxides and aqueous electrolyte such as Ti4+, Zn2+, Na+ and SO32- can occupy some pores within the high-surface-area AC electrodes, forming the electric double layer at the electrode-electrolyte interface. Additionally, both TiO2 and ZnO nanoparticles can provide favourable surface adsorption sites for SO32- anions which subsequently facilitate the faradaic processes for pseudocapacitive effect. These two systems provide the low cost material electrodes and the low environmental impact electrolyte which offer the increased charge storage without compromising charge storage kinetics.

Advanced space propulsion concepts

NASA Technical Reports Server (NTRS)

Lapointe, Michael R.

1993-01-01

The NASA Lewis Research Center has been actively involved in the evaluation and development of advanced spacecraft propulsion. Recent program elements have included high energy density propellants, electrode less plasma thruster concepts, and low power laser propulsion technology. A robust advanced technology program is necessary to develop new, cost-effective methods of spacecraft propulsion, and to continue to push the boundaries of human knowledge and technology.

Room-temperature solution-processed and metal oxide-free nano-composite for the flexible transparent bottom electrode of perovskite solar cells

NASA Astrophysics Data System (ADS)

Lu, Haifei; Sun, Jingsong; Zhang, Hong; Lu, Shunmian; Choy, Wallace C. H.

2016-03-01

The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies.The exploration of low-temperature and solution-processed charge transporting and collecting layers can promote the development of low-cost and large-scale perovskite solar cells (PVSCs) through an all solution process. Here, we propose a room-temperature solution-processed and metal oxide-free nano-composite composed of a silver nano-network and graphene oxide (GO) flawless film for the transparent bottom electrode of a PVSC. Our experimental results show that the amount of GO flakes play a critical role in forming the flawless anti-corrosive barrier in the silver nano-network through a self-assembly approach under ambient atmosphere, which can effectively prevent the penetration of liquid or gaseous halides and their corrosion against the silver nano-network underneath. Importantly, we simultaneously achieve good work function alignment and surface wetting properties for a practical bottom electrode by controlling the degree of reduction of GO flakes. Finally, flexible PVSC adopting the room-temperature and solution-processed nano-composite as the flexible transparent bottom electrode has been demonstrated on a polyethylene terephthalate (PET) substrate. As a consequence, the demonstration of our room-temperature solution-processed and metal oxide-free flexible transparent bottom electrode will contribute to the emerging large-area flexible PVSC technologies. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr00011h

Durable and water-floatable ionic polymer actuator with hydrophobic and asymmetrically laser-scribed reduced graphene oxide paper electrodes.

PubMed

Kim, Jaehwan; Jeon, Jin-Han; Kim, Hyun-Jun; Lim, Hyuneui; Oh, Il-Kwon

2014-03-25

Ionic polymer actuators driven by electrical stimuli have been widely investigated for use in practical applications such as bioinspired robots, sensors, and biomedical devices. However, conventional ionic polymer-metal composite actuators have a serious drawback of poor durability under long-term actuation in open air, mainly because of the leakage of the inner electrolyte and hydrated cations through cracks in the metallic electrodes. Here, we developed a highly durable and water-floatable ionic polymer artificial muscle by employing hydrophobic and asymmetrically laser-scribed reduced graphene oxide paper electrodes (HLrGOP). The highly conductive, flexible, and cost-effective HLrGOP electrodes have asymmetrically smooth hydrophobic outer and rough inner surfaces, resulting in liquid-impermeable and water-floatable functionalities and strong bonding between an ionic polymer and the electrodes. More interestingly, the HLrGOP electrode, which has a unique functionality to prevent the leakage of the vaporized or liquid electrolyte and mobile ions during electrical stimuli, greatly contributes to an exceptionally durable ionic polymer-graphene composite actuator that is a prerequisite for practical applications in active biomedical devices, biomimetic robots, touch-feedback haptic systems, and flexible soft electronics.

Robust solder joint attachment of coaxial cable leads to piezoelectric ceramic electrodes.

PubMed

Vianco, P T

1993-01-01

A technique was developed for the solder attachment of coaxial cable leads to silver-bearing thick-film electrodes on piezoelectric ceramics. Soldering the cable leads directly to the thick film caused bonds with low mechanical strength due to poor solder joint geometry. A barrier coating of 1.5 mum Cu/1.5 mum Ni/1.0 mum Sn deposited on the thick-film layer improved the strength of the solder joints by eliminating the adsorption of Ag from the thick film, which was responsible for the improper solder joint geometry. The procedure does not require special preparation of the electrode surface and is cost effective due to the use of nonprecious metal films and the batch processing capabilities of the electron beam deposition technique.

Buried MoO x/Ag Electrode Enables High-Efficiency Organic/Silicon Heterojunction Solar Cells with a High Fill Factor.

PubMed

Xia, Zhouhui; Gao, Peng; Sun, Teng; Wu, Haihua; Tan, Yeshu; Song, Tao; Lee, Shuit-Tong; Sun, Baoquan

2018-04-25

Silicon (Si)/organic heterojunction solar cells based on poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) and n-type Si have attracted wide interests because they promise cost-effectiveness and high-efficiency. However, the limited conductivity of PEDOT:PSS leads to an inefficient hole transport efficiency for the heterojunction device. Therefore, a high dense top-contact metal grid electrode is required to assure the efficient charge collection efficiency. Unfortunately, the large metal grid coverage ratio electrode would lead to undesirable optical loss. Here, we develop a strategy to balance PEDOT:PSS conductivity and grid optical transmittance via a buried molybdenum oxide/silver grid electrode. In addition, the grid electrode coverage ratio is optimized to reduce its light shading effect. The buried electrode dramatically reduces the device series resistance, which leads to a higher fill factor (FF). With the optimized buried electrode, a record FF of 80% is achieved for flat Si/PEDOT:PSS heterojunction devices. With further enhancement adhesion between the PEDOT:PSS film and Si substrate by a chemical cross-linkable silance, a power conversion efficiency of 16.3% for organic/textured Si heterojunction devices is achieved. Our results provide a path to overcome the inferior organic semiconductor property to enhance the organic/Si heterojunction solar cell.

Harvesting waste thermal energy using a carbon-nanotube-based thermo-electrochemical cell.

PubMed

Hu, Renchong; Cola, Baratunde A; Haram, Nanda; Barisci, Joseph N; Lee, Sergey; Stoughton, Stephanie; Wallace, Gordon; Too, Chee; Thomas, Michael; Gestos, Adrian; Cruz, Marilou E Dela; Ferraris, John P; Zakhidov, Anvar A; Baughman, Ray H

2010-03-10

Low efficiencies and costly electrode materials have limited harvesting of thermal energy as electrical energy using thermo-electrochemical cells (or "thermocells"). We demonstrate thermocells, in practical configurations (from coin cells to cells that can be wrapped around exhaust pipes), that harvest low-grade thermal energy using relatively inexpensive carbon multiwalled nanotube (MWNT) electrodes. These electrodes provide high electrochemically accessible surface areas and fast redox-mediated electron transfer, which significantly enhances thermocell current generation capacity and overall efficiency. Thermocell efficiency is further improved by directly synthesizing MWNTs as vertical forests that reduce electrical and thermal resistance at electrode/substrate junctions. The efficiency of thermocells with MWNT electrodes is shown to be as high as 1.4% of Carnot efficiency, which is 3-fold higher than for previously demonstrated thermocells. With the cost of MWNTs decreasing, MWNT-based thermocells may become commercially viable for harvesting low-grade thermal energy.

Advanced Architectures and Relatives of Air Electrodes in Zn-Air Batteries.

PubMed

Pan, Jing; Xu, Yang Yang; Yang, Huan; Dong, Zehua; Liu, Hongfang; Xia, Bao Yu

2018-04-01

Zn-air batteries are becoming the promising power sources for portable and wearable electronic devices and hybrid/electric vehicles because of their high specific energy density and the low cost for next-generation green and sustainable energy technologies. An air electrode integrated with an oxygen electrocatalyst is the most important component and inevitably determines the performance and cost of a Zn-air battery. This article presents exciting advances and challenges related to air electrodes and their relatives. After a brief introduction of the Zn-air battery, the architectures and oxygen electrocatalysts of air electrodes and relevant electrolytes are highlighted in primary and rechargeable types with different configurations, respectively. Moreover, the individual components and major issues of flexible Zn-air batteries are also highlighted, along with the strategies to enhance the battery performance. Finally, a perspective for design, preparation, and assembly of air electrodes is proposed for the future innovations of Zn-air batteries with high performance.

Low-cost optical fabrication of flexible copper electrode via laser-induced reductive sintering and adhesive transfer

NASA Astrophysics Data System (ADS)

Back, Seunghyun; Kang, Bongchul

2018-02-01

Fabricating copper electrodes on heat-sensitive polymer films in air is highly challenging owing to the need of expensive copper nanoparticles, rapid oxidation of precursor during sintering, and limitation of sintering temperature to prevent the thermal damage of the polymer film. A laser-induced hybrid process of reductive sintering and adhesive transfer is demonstrated to cost-effectively fabricate copper electrode on a polyethylene film with a thermal resistance below 100 °C. A laser-induced reductive sintering process directly fabricates a high-conductive copper electrode onto a glass donor from copper oxide nanoparticle solution via photo-thermochemical reduction and agglomeration of copper oxide nanoparticles. The sintered copper patterns were transferred in parallel to a heat-sensitive polyethylene film through self-selective surface adhesion of the film, which was generated by the selective laser absorption of the copper pattern. The method reported here could become one of the most important manufacturing technologies for fabricating low-cost wearable and disposable electronics.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, Aladsair J.; Viswanathan, Vilayanur V.; Stephenson, David E.

A robust performance-based cost model is developed for all-vanadium, iron-vanadium and iron chromium redox flow batteries. Systems aspects such as shunt current losses, pumping losses and thermal management are accounted for. The objective function, set to minimize system cost, allows determination of stack design and operating parameters such as current density, flow rate and depth of discharge (DOD). Component costs obtained from vendors are used to calculate system costs for various time frames. A 2 kW stack data was used to estimate unit energy costs and compared with model estimates for the same size electrodes. The tool has been sharedmore » with the redox flow battery community to both validate their stack data and guide future direction.« less

A new type of high energy asymmetric capacitor with nanoporous carbon electrodes in aqueous electrolyte

NASA Astrophysics Data System (ADS)

Khomenko, V.; Raymundo-Piñero, E.; Béguin, F.

A new type of low cost and high energy asymmetric capacitor based on only activated carbons for both electrodes has been developed in a safe and environment friendly aqueous electrolyte. In such electrolyte, the charges are stored in the electrical double-layer and through fast faradaic charge transfer processes. By taking profit of different redox reactions occurring in the positive and negative ranges of potential, it is possible to optimize the capacitor either by balancing the mass of the electrodes or by using different optimized carbons for the positive and negative electrodes. The best results are obtained in the latter case, by utilizing different pseudo-faradaic properties of carbons in order to increase the capacitance and to shift the potentials of water decomposition and destructive oxidation of activated carbon to more negative and positive values, respectively. After an additional adjustment of potentials by mass-balancing the two electrodes, the electrochemical capacitor can be reversibly charged/discharged at 1.6 V in aqueous medium, with energy densities close to the values obtained with electrical double-layer capacitors working in organic electrolytes, while avoiding their disadvantages.

Merging of Kirkendall Growth and Ostwald Ripening: CuO@MnO2 Core-shell Architectures for Asymmetric Supercapacitors

PubMed Central

Huang, Ming; Zhang, Yuxin; Li, Fei; Wang, Zhongchang; Alamusi; Hu, Ning; Wen, Zhiyu; Liu, Qing

2014-01-01

Fabricating hierarchical core-shell nanostructures is currently the subject of intensive research in the electrochemical field owing to the hopes it raises for making efficient electrodes for high-performance supercapacitors. Here, we develop a simple and cost-effective approach to prepare CuO@MnO2 core-shell nanostructures without any surfactants and report their applications as electrodes for supercapacitors. An asymmetric supercapacitor with CuO@MnO2 core-shell nanostructure as the positive electrode and activated microwave exfoliated graphite oxide (MEGO) as the negative electrode yields an energy density of 22.1 Wh kg−1 and a maximum power density of 85.6 kW kg−1; the device shows a long-term cycling stability which retains 101.5% of its initial capacitance even after 10000 cycles. Such a facile strategy to fabricate the hierarchical CuO@MnO2 core-shell nanostructure with significantly improved functionalities opens up a novel avenue to design electrode materials on demand for high-performance supercapacitor applications. PMID:24682149

Cost and performance model for redox flow batteries

NASA Astrophysics Data System (ADS)

Viswanathan, Vilayanur; Crawford, Alasdair; Stephenson, David; Kim, Soowhan; Wang, Wei; Li, Bin; Coffey, Greg; Thomsen, Ed; Graff, Gordon; Balducci, Patrick; Kintner-Meyer, Michael; Sprenkle, Vincent

2014-02-01

A cost model is developed for all vanadium and iron-vanadium redox flow batteries. Electrochemical performance modeling is done to estimate stack performance at various power densities as a function of state of charge and operating conditions. This is supplemented with a shunt current model and a pumping loss model to estimate actual system efficiency. The operating parameters such as power density, flow rates and design parameters such as electrode aspect ratio and flow frame channel dimensions are adjusted to maximize efficiency and minimize capital costs. Detailed cost estimates are obtained from various vendors to calculate cost estimates for present, near-term and optimistic scenarios. The most cost-effective chemistries with optimum operating conditions for power or energy intensive applications are determined, providing a roadmap for battery management systems development for redox flow batteries. The main drivers for cost reduction for various chemistries are identified as a function of the energy to power ratio of the storage system. Levelized cost analysis further guide suitability of various chemistries for different applications.

Future materials requirements for the high-energy-intensity production of aluminum

NASA Astrophysics Data System (ADS)

Welch, B. J.; Hyland, M. M.; James, B. J.

2001-02-01

Like all metallurgical industries, aluminum smelting has been under pressure from two fronts—to give maximum return on investment to the shareholders and to comply with environmental regulations by reducing greenhouse emissions. The smelting process has advanced by improving efficiency and productivity while continuing to seek new ways to extend the cell life. Materials selection (particularly the use of more graphitized cathodic electrodes) has enabled lower energy consumption, while optimization of the process and controlling in a narrow band has enabled increases in productivity and operations at higher current densities. These changes have, in turn, severely stressed the materials used for cell construction, and new problems are emerging that are resulting in a reduction of cell life. The target for aluminum electro-winning has been to develop an oxygen-evolving electrode, rather than one that evolves substantial amounts of carbon dioxide. Such an electrode, when combined with suitable wettable cathode material developments, would reduce operating costs by eliminating the need for frequent electrode change and would enable more productive cell designs and reduce plant size. The materials specifications for developing these are, however, an extreme challenge. Those specifications include minimized corrosion rate of any electrode into the electrolyte, maintaining an electronically conducting oxidized surface that is of low electrical resistance, meeting the metal purity targets, and enabling variable operating current densities. Although the materials specifications can readily be written, the processing and production of the materials is the challenge.

Fluid electrodes for submersible robotics based on dielectric elastomer actuators

NASA Astrophysics Data System (ADS)

Christianson, Caleb; Goldberg, Nathaniel; Cai, Shengqiang; Tolley, Michael T.

2017-04-01

Recently, dielectric elastomer actuators (DEAs) have gathered interest for soft robotics due to their low cost, light weight, large strain, low power consumption, and high energy density. However, developing reliable, compliant electrodes for DEAs remains an ongoing challenge due to issues with fabrication, uniformity of the conductive layer, and mechanical stiffening of the actuators caused by conductive materials with large Young's moduli. In this work, we present a method for preparing, patterning, and utilizing conductive fluid electrodes. Further, when we submerse the DEAs in a bath containing a conductive fluid connected to ground, the bath serves as a second electrode, obviating the need for depositing a conductive layer to serve as either of the electrodes required of most DEAs. When we apply a positive electrical potential to the conductive fluid in the actuator with respect to ground, the electric field across the dielectric membrane causes charge carriers in the solution to apply an electrostatic force on the membrane, which compresses the membrane and causes the actuator to deform. We have used this process to develop a tethered submersible robot that can swim in a tank of saltwater at a maximum measured speed of 9.2 mm/s. Since saltwater serves as the electrode, we overcome buoyancy issues that may be a challenge for pneumatically actuated soft robots and traditional, rigid robotics. This research opens the door to low-power underwater robots for search and rescue and environmental monitoring applications.

Nickel-based electrodeposits as potential cathode catalysts for hydrogen production by microbial electrolysis

NASA Astrophysics Data System (ADS)

Mitov, M.; Chorbadzhiyska, E.; Nalbandian, L.; Hubenova, Y.

2017-07-01

The development of cost-effective cathodes, operating at neutral pH and ambient temperatures, is a crucial challenge for the practical application of microbial electrolysis cell (MEC) technology. In this study, NiW and NiMo co-deposits produced by electroplating on Ni-foam are explored as cathodes in MEC. The fabricated electrodes exhibit higher corrosion stability and enhanced electrocatalytic activity towards hydrogen evolution reaction in neutral electrolyte compared to the bare Ni-foam. NiW/Ni-foam electrodes possess six times higher intrinsic catalytic activity, estimated from data obtained by linear voltammetry and chronoamperometry. The newly developed electrodes are applied as cathodes in single-chamber membrane-free MEC reactors, inoculated with wastewater and activated sludge from a municipal wastewater treatment plant. Cathodic hydrogen recovery of 79% and 89% by using NiW and NiMo cathodes, respectively, is achieved at applied voltage of 0.6 V. The obtained results reveal potential for practical application of used catalysts in MEC.

Development of an integrated electrochemical system for in vitro yeast viability testing.

PubMed

Adami, Andrea; Ress, Cristina; Collini, Cristian; Pedrotti, Severino; Lorenzelli, Leandro

2013-02-15

This work describes the development and testing of a microfabricated sensor for rapid cell growth monitoring, especially focused on yeast quality assessment for wine applications. The device consists of a NMOS ISFET sensor with Si(3)N(4) gate, able to indirectly monitor extracellular metabolism through pH variation of the medium, and a solid-state reference electrode implemented with PVC membranes doped with lipophilic salts (tetrabutylammonium-tetrabutylborate (TBA-TBB) and Potassium tetrakis(4-chlorphenyl)borate (KTClpB)). The use of a solid state reference electrode enables the implementation of a large number of cell assays in parallel, without the need of external conventional reference electrodes. Microbial growth testing has been performed both in standard culture conditions and on chip at different concentrations of ethanol in order to carry out a commonly used screening of wine yeast strains. Cell growth tests can be performed in few hours, providing a fast, sensitive and low cost analysis with respect to the conventional procedures. Copyright © 2012 Elsevier B.V. All rights reserved.

Whole Wafer Design and Fabrication for the Alignment of Nanostructures for Chemical Sensor Applications

NASA Technical Reports Server (NTRS)

Biaggi-Labiosa, Azlin M.; Hunter, Gary W.

2013-01-01

A major objective in aerospace sensor development is to produce sensors that are small in size, easy to batch fabricate and low in cost, and have low power consumption The fabrication of chemical sensors involving nanostructured materials can provide these properties as well as the potential for the development of sensor systems with unique properties and improved performance. However, the fabrication and processing of nanostructures for sensor applications currently is limited in the ability to control their location on the sensor. Currently, our group at NASA Glenn Research Center has demonstrated the controlled placement of nanostructures in sensors using a sawtooth patterned electrode design. With this design the nanostructures are aligned between opposing sawtooth electrodes by applying an alternating current.

Electrochemical sensing of heavy metal ions with inorganic, organic and bio-materials.

PubMed

Cui, Lin; Wu, Jie; Ju, Huangxian

2015-01-15

As heavy metal ions severely harm human health, it is important to develop simple, sensitive and accurate methods for their detection in environment and food. Electrochemical detection featured with short analytical time, low power cost, high sensitivity and easy adaptability for in-situ measurement is one of the most developed methods. This review introduces briefly the recent achievements in electrochemical sensing of heavy metal ions with inorganic, organic and bio-materials modified electrodes. In particular, the unique properties of inorganic nanomaterials, organic small molecules or their polymers, enzymes and nucleic acids for detection of heavy metal ions are highlighted. By employing some representative examples, the design and sensing mechanisms of these electrodes are discussed. Copyright © 2014 Elsevier B.V. All rights reserved.

3D resistivity survey for shallow subsurface fault investigations

NASA Astrophysics Data System (ADS)

Petrit, Kraipat; Klamthim, Poonnapa; Duerrast, Helmut

2018-03-01

The shallow subsurface is subject to various human activities, and the place of occurrence of geohazards, e.g. shallow active faults. The identification of the location and orientation of such faults can be vital for infrastructure development. The aim of this study was to develop a low-cost 3D resistivity survey system, with reasonable survey time for shallow fault investigations. The study area in Songkhla Province, Thailand is located in an old quarry where faults could be identified in outcrops. The study area was designed to cover the expected fault with 100 electrodes arranged in a 10×10 square grid with an electrode spacing of 3 meters in x and y axis. Each electrode in turn was used as a current and potential electrode using a dipole-dipole array. Field data have been processed and interpreted using 3DResINV. Results, presented in horizontal depth slices and vertical xz- and yz-cross sections, revealed through differences in resistivity down to 8 m depths a complex structural setting with two shallow faults and dipping sedimentary rock layers. In conclusion, this study has shown that a 3D resistivity survey can imagine complex tectonic structures, thus providing a far more insight into the shallow subsurface.

A highly sensitive and specific capacitive aptasensor for rapid and label-free trace analysis of Bisphenol A (BPA) in canned foods.

PubMed

Mirzajani, Hadi; Cheng, Cheng; Wu, Jayne; Chen, Jiangang; Eda, Shigotoshi; Najafi Aghdam, Esmaeil; Badri Ghavifekr, Habib

2017-03-15

A rapid, highly sensitive, specific and low-cost capacitive affinity biosensor is presented here for label-free and single step detection of Bisphenol A (BPA). The sensor design allows rapid prototyping at low-cost using printed circuit board material by benchtop equipment. High sensitivity detection is achieved through the use of a BPA-specific aptamer as probe molecule and large electrodes to enhance AC-electroelectrothermal effect for long-range transport of BPA molecules toward electrode surface. Capacitive sensing technique is used to determine the bounded BPA level by measuring the sample/electrode interfacial capacitance of the sensor. The developed biosensor can detect BPA level in 20s and exhibits a large linear range from 1 fM to 10 pM, with a limit of detection (LOD) of 152.93 aM. This biosensor was applied to test BPA in canned food samples and could successfully recover the levels of spiked BPA. This sensor technology is demonstrated to be highly promising and reliable for rapid, sensitive and on-site monitoring of BPA in food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Preparation of nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel as a binder-free electrode for high performance supercapacitors

NASA Astrophysics Data System (ADS)

Zhang, Yimei; Wang, Fei; Zhu, Hao; Zhou, Lincheng; Zheng, Xinliang; Li, Xinghua; Chen, Zhuang; Wang, Yue; Zhang, Dandan; Pan, Duo

2017-12-01

Carbon materials derived from various biomasses have aroused forceful interest from scientific community based on their abundant resource, low cost, environment friendly and easy fabrication. Herein, the method has been developed to prepare nitrogen-doped biomass-derived carbon nanofibers/graphene aerogel (NCGA) as the binder-free electrode for supercapacitors. Ethylenediamine (EDA) is select as nitrogen source for its high nitrogen content and strong interaction with graphene oxide (GO) and cellulose nanofibers (CNFs) via hydrothermal self-assembly method to form hybrid hydrogel, and finally converts to NCGA by freeze-drying and carbonization. After carbonization the insulated CNFs converted to high conductivity carbon nanofibers. The NCGA electrode exhibits a high specific capacitance of 289 F g-1 at 5 mV s-1 and high stability of 90.5% capacitance retention ratio after 5000 cycles at 3 A g-1. This novel biomass electrode could be potential candidate for high performance supercapacitors.

A Wearable Hydration Sensor with Conformal Nanowire Electrodes.

PubMed

Yao, Shanshan; Myers, Amanda; Malhotra, Abhishek; Lin, Feiyan; Bozkurt, Alper; Muth, John F; Zhu, Yong

2017-03-01

A wearable skin hydration sensor in the form of a capacitor is demonstrated based on skin impedance measurement. The capacitor consists of two interdigitated or parallel electrodes that are made of silver nanowires (AgNWs) in a polydimethylsiloxane (PDMS) matrix. The flexible and stretchable nature of the AgNW/PDMS electrode allows conformal contact to the skin. The hydration sensor is insensitive to the external humidity change and is calibrated against a commercial skin hydration system on an artificial skin over a wide hydration range. The hydration sensor is packaged into a flexible wristband, together with a network analyzer chip, a button cell battery, and an ultralow power microprocessor with Bluetooth. In addition, a chest patch consisting of a strain sensor, three electrocardiography electrodes, and a skin hydration sensor is developed for multimodal sensing. The wearable wristband and chest patch may be used for low-cost, wireless, and continuous monitoring of skin hydration and other health parameters. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

A Drinking Water Sensor for Lead and Other Heavy Metals.

PubMed

Lin, Wen-Chi; Li, Zhongrui; Burns, Mark A

2017-09-05

Leakage of lead and other heavy metals into drinking water is a significant health risk and one that is not easily detected. We have developed simple sensors containing only platinum electrodes for the detection of heavy metal contamination in drinking water. The two-electrode sensor can identify the existence of a variety of heavy metals in drinking water, and the four-electrode sensor can distinguish lead from other heavy metals in solution. No false-positive response is generated when the sensors are placed in simulated and actual tap water contaminated by heavy metals. Lead detection on the four-electrode sensor is not affected by the presence of common ions in tap water. Experimental results suggest the sensors can be embedded in water service lines for long-time use until lead or other heavy metals are detected. With its low cost (∼$0.10/sensor) and the possibility of long-term operation, the sensors are ideal for heavy metal detection of drinking water.

Research, development and demonstration of nickel-iron batteries for electric-vehicle propulsion

NASA Astrophysics Data System (ADS)

1982-03-01

Full-size, prototype cell, module and battery fabrication and evaluation, aimed at advancing the technical capabilities of the nickel-iron battery, while simultaneously reducing its potential cost in materials and process areas are discussed. Improved electroprecipitation process nickel electrodes of design thickness (2.5 mm) are now being prepared that display stable capacities for the C/3 drain rate with less than 10% capacity decline for greater than 1000 test cycles. Iron electrodes of the composite-type are delivering 24 Ah at the target thickness (1.0 mm). Iron electrodes also are displaying capacity stability for greater than 1000 test cycles in continuing 3-plate cell tests. Finished cells delivered 57 to 63 Wh/kg at C/3, and have demonstrated cyclic stability up to 1200 cycles at 80 percent depth of discharge profiles. Modules exceeded 580 test cycles and remain on test. Reduction in nickel electrode swelling (and concurrent stack starvation), to improve cycling, continues to be an area of major effort to reach the final battery cycle life objectives.

Fabrication of Lab-on-Paper Using Porous Au-Paper Electrode: Application to Tumor Marker Electrochemical Immunoassays.

PubMed

Ge, Shenguang; Zhang, Yan; Yan, Mei; Huang, Jiadong; Yu, Jinghua

2017-01-01

A simple, low-cost, and sensitive electrochemical lab-on-paper assay is developed based on a novel gold nanoparticle modified porous paper working electrode for use in point-of-care testing (POCT). Electrochemical methods are introduced for lab-on-paper based on screen-printed paper electrodes. To further improve specificity, performance, and sensitivity for point-of-care testing, a novel porous Au-paper working electrode (Au-PWE) is designed for lab-on-paper using growth of an interconnected Au nanoparticle (NP) layer on the surface of cellulose fibers in order to enhance the conductivity of the paper sample zone and immobilize the primary antibodies (Ab1). With a sandwich-type immunoassay format, Pd-Au bimetallic nanoparticles possessing peroxidase-like activity are used as a matrix to immobilize secondary antibodies (Ab2) for rapid detection of targets. This lab-on-paper based immunodevice is applied to the diagnosis of a cancer biomarker in clinical serum samples.

Scalable Functionalized Graphene Nano-platelets as Tunable Cathodes for High-performance Lithium Rechargeable Batteries

PubMed Central

Kim, Haegyeom; Lim, Hee-Dae; Kim, Sung-Wook; Hong, Jihyun; Seo, Dong-Hwa; Kim, Dae-chul; Jeon, Seokwoo; Park, Sungjin; Kang, Kisuk

2013-01-01

High-performance and cost-effective rechargeable batteries are key to the success of electric vehicles and large-scale energy storage systems. Extensive research has focused on the development of (i) new high-energy electrodes that can store more lithium or (ii) high-power nano-structured electrodes hybridized with carbonaceous materials. However, the current status of lithium batteries based on redox reactions of heavy transition metals still remains far below the demands required for the proposed applications. Herein, we present a novel approach using tunable functional groups on graphene nano-platelets as redox centers. The electrode can deliver high capacity of ~250 mAh g−1, power of ~20 kW kg−1 in an acceptable cathode voltage range, and provide excellent cyclability up to thousands of repeated charge/discharge cycles. The simple, mass-scalable synthetic route for the functionalized graphene nano-platelets proposed in this work suggests that the graphene cathode can be a promising new class of electrode. PMID:23514953

Synthesis of Ammonia-Assisted Porous Nickel Ferrite (NiFe₂O₄) Nanostructures as an Electrode Material for Supercapacitors.

PubMed

Bhojane, Prateek; Sharma, Alfa; Pusty, Manojit; Kumar, Yogendra; Sen, Somaditya; Shirage, Parasharam

2017-02-01

In this work, we report a low cost, facile synthesis method for Nickel ferrite (NiFe₂O₄) nanostructures obtained by chemical bath deposition method for alternate transition metal oxide electrode material as a solution for clean energy. We developed a template free ammonia assisted method for obtaining porous structure which offering better supercapacitive performance of NiFe₂O₄ electrode material than previously reported for pure NiFe₂O₄. Here we explore the physical characterizations X-ray diffraction, FESEM, HRTEM performed to under-stand its crystal structure and morphology as well as the electrochemical measurements was performed to understand the electrochemical behaviour of the material. Here ammonia plays an important role in governing the structure/morphology of the material and enhances the electrochemical performance. The specific capacitance of 541 Fg⁻¹ is achieved at 2 mVs⁻¹ scan rate which is highest for the pure NiFe₂O₄ electrode material without using any addition of carbon based material, heterostructure or template based method.

Enhanced Discharge Performance in a Ring Cusp Plasma Source

NASA Technical Reports Server (NTRS)

Foster, John E.; Patterson, Michael J.

2000-01-01

There is a need for a lightweight, low power ion thruster for space science missions. Such an ion thruster is under development at NASA Glenn Research Center. In an effort to better understand the discharge performance of this thruster, a thruster discharge chamber with an anode containing electrically isolated electrodes at the cusps was fabricated and tested. Characteristics of this ring cusp ion discharge were measured without ion beam extraction. Discharge current was measured at collection electrodes located at the magnetic cusps and at the anode body itself. Discharge performance and plasma properties were measured as a function of power, which was varied between 20 and 50 W. It was found that ion production costs decreased by as much as 20 percent when the two most downstream cusp electrodes were allowed to float. Floating the electrodes did not give rise to a significant increase in discharge power even though the plasma density increased markedly. The improved performance is attributed to enhanced electron containment.

Internal Plasma Properties and Enhanced Performance of an 8 cm Ion Thruster Discharge

NASA Technical Reports Server (NTRS)

Foster, John E.; Patterson, Michael J.

1999-01-01

There is a need for a lightweight, low power ion thruster for space science missions. Such an ion thruster is under development at NASA Glenn Research Center. In an effort to better understand the discharge performance of this thruster. a version of this thruster with an anode containing electrically isolated electrodes at the cusps was fabricated and tested. Discharge characteristics of this ring cusp ion thruster were measured without ion beam extraction. Discharge current was measured at collection electrodes located at the cusps and at the anode body itself. Discharge performance and plasma properties were measured as a function of discharge power, which was varied between 20 and 50 W. It was found that ion production costs decreased by as much as 20 percent when the two most downstream cusp electrodes were allowed to float. Floating the electrodes did not give rise to a significant increase in discharge power even though the plasma density increased markedly. The improved performance is attributed to enhanced electron containment.

Phosphate Framework Electrode Materials for Sodium Ion Batteries

PubMed Central

Fang, Yongjin; Zhang, Jiexin; Xiao, Lifen; Ai, Xinping; Yang, Hanxi

2017-01-01

Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li‐ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single‐phosphates, pyrophosphates and mixed‐phosphates. We provide the detailed and comprehensive understanding of structure–composition–performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next‐generation of energy storage devices. PMID:28546907

Wearable energy-dense and power-dense supercapacitor yarns enabled by scalable graphene-metallic textile composite electrodes.

PubMed

Liu, Libin; Yu, You; Yan, Casey; Li, Kan; Zheng, Zijian

2015-06-11

One-dimensional flexible supercapacitor yarns are of considerable interest for future wearable electronics. The bottleneck in this field is how to develop devices of high energy and power density, by using economically viable materials and scalable fabrication technologies. Here we report a hierarchical graphene-metallic textile composite electrode concept to address this challenge. The hierarchical composite electrodes consist of low-cost graphene sheets immobilized on the surface of Ni-coated cotton yarns, which are fabricated by highly scalable electroless deposition of Ni and electrochemical deposition of graphene on commercial cotton yarns. Remarkably, the volumetric energy density and power density of the all solid-state supercapacitor yarn made of one pair of these composite electrodes are 6.1 mWh cm(-3) and 1,400 mW cm(-3), respectively. In addition, this SC yarn is lightweight, highly flexible, strong, durable in life cycle and bending fatigue tests, and integratable into various wearable electronic devices.

Phosphate Framework Electrode Materials for Sodium Ion Batteries.

PubMed

Fang, Yongjin; Zhang, Jiexin; Xiao, Lifen; Ai, Xinping; Cao, Yuliang; Yang, Hanxi

2017-05-01

Sodium ion batteries (SIBs) have been considered as a promising alternative for the next generation of electric storage systems due to their similar electrochemistry to Li-ion batteries and the low cost of sodium resources. Exploring appropriate electrode materials with decent electrochemical performance is the key issue for development of sodium ion batteries. Due to the high structural stability, facile reaction mechanism and rich structural diversity, phosphate framework materials have attracted increasing attention as promising electrode materials for sodium ion batteries. Herein, we review the latest advances and progresses in the exploration of phosphate framework materials especially related to single-phosphates, pyrophosphates and mixed-phosphates. We provide the detailed and comprehensive understanding of structure-composition-performance relationship of materials and try to show the advantages and disadvantages of the materials for use in SIBs. In addition, some new perspectives about phosphate framework materials for SIBs are also discussed. Phosphate framework materials will be a competitive and attractive choice for use as electrodes in the next-generation of energy storage devices.

Wearable energy-dense and power-dense supercapacitor yarns enabled by scalable graphene–metallic textile composite electrodes

PubMed Central

Liu, Libin; Yu, You; Yan, Casey; Li, Kan; Zheng, Zijian

2015-01-01

One-dimensional flexible supercapacitor yarns are of considerable interest for future wearable electronics. The bottleneck in this field is how to develop devices of high energy and power density, by using economically viable materials and scalable fabrication technologies. Here we report a hierarchical graphene–metallic textile composite electrode concept to address this challenge. The hierarchical composite electrodes consist of low-cost graphene sheets immobilized on the surface of Ni-coated cotton yarns, which are fabricated by highly scalable electroless deposition of Ni and electrochemical deposition of graphene on commercial cotton yarns. Remarkably, the volumetric energy density and power density of the all solid-state supercapacitor yarn made of one pair of these composite electrodes are 6.1 mWh cm−3 and 1,400 mW cm−3, respectively. In addition, this SC yarn is lightweight, highly flexible, strong, durable in life cycle and bending fatigue tests, and integratable into various wearable electronic devices. PMID:26068809

Sensitive Adsorptive Voltammetric Method for Determination of Bisphenol A by Gold Nanoparticle/Polyvinylpyrrolidone-Modified Pencil Graphite Electrode

PubMed Central

Yaman, Yesim Tugce; Abaci, Serdar

2016-01-01

A novel electrochemical sensor gold nanoparticle (AuNP)/polyvinylpyrrolidone (PVP) modified pencil graphite electrode (PGE) was developed for the ultrasensitive determination of Bisphenol A (BPA). The gold nanoparticles were electrodeposited by constant potential electrolysis and PVP was attached by passive adsorption onto the electrode surface. The electrode surfaces were characterized by electrochemical impedance spectroscopy (EIS) and scanning electron microscopy (SEM). The parameters that affected the experimental conditions were researched and optimized. The AuNP/PVP/PGE sensor provided high sensitivity and selectivity for BPA recognition by using square wave adsorptive stripping voltammetry (SWAdSV). Under optimized conditions, the detection limit was found to be 1.0 nM. This new sensor system offered the advantages of simple fabrication which aided the expeditious replication, low cost, fast response, high sensitivity and low background current for BPA. This new sensor system was successfully tested for the detection of the amount of BPA in bottled drinking water with high reliability. PMID:27231912

High-performance NiO/Ag/NiO transparent electrodes for flexible organic photovoltaic cells.

PubMed

Xue, Zhichao; Liu, Xingyuan; Zhang, Nan; Chen, Hong; Zheng, Xuanming; Wang, Haiyu; Guo, Xiaoyang

2014-09-24

Transparent electrodes with a dielectric-metal-dielectric (DMD) structure can be implemented in a simple manufacturing process and have good optical and electrical properties. In this study, nickel oxide (NiO) is introduced into the DMD structure as a more appropriate dielectric material that has a high conduction band for electron blocking and a low valence band for efficient hole transport. The indium-free NiO/Ag/NiO (NAN) transparent electrode exhibits an adjustable high transmittance of ∼82% combined with a low sheet resistance of ∼7.6 Ω·s·q(-1) and a work function of 5.3 eV after UVO treatment. The NAN electrode shows excellent surface morphology and good thermal, humidity, and environmental stabilities. Only a small change in sheet resistance can be found after NAN electrode is preserved in air for 1 year. The power conversion efficiencies of organic photovoltaic cells with NAN electrodes deposited on glass and polyethylene terephthalate (PET) substrates are 6.07 and 5.55%, respectively, which are competitive with those of indium tin oxide (ITO)-based devices. Good photoelectric properties, the low-cost material, and the room-temperature deposition process imply that NAN electrode is a striking candidate for low-cost and flexible transparent electrode for efficient flexible optoelectronic devices.

Chemical sintering of direct-written silver nanowire flexible electrodes under room temperature.

PubMed

Hui, Zhuang; Liu, Yangai; Guo, Wei; Li, Lihang; Mu, Nan; Jin, Chao; Zhu, Ying; Peng, Peng

2017-07-14

Transparent and flexible electrodes on cost effective plastic substrates for wearable electronics have attract great attention recently. Due to the conductivity and flexibility in network form, metal nanowire is regarded as one of the most promising candidates for flexible electrode fabrication. Prior to application, low temperature joining of nanowire processes are required to reduce the resistance of electrodes and simultaneously maintain the dimensionality and uniformity of those nanowires. In the present work, we presented an innovative, robust and cost effective method to minimize the heat effect to plastic substrate and silver nanowires which allows silver nanowire electrodes been directly written on polycarbonate substrate and sintered by different electrolyte solutions at room temperature or near. It has been rigorously demonstrated that the resistance of silver nanowire electrodes has been reduced by 90% after chemical sintering at room temperature due to the joining of silver nanowires at junction areas. After ∼1000 bending cycles, the measured resistance of silver nanowire electrode was stable during both up-bending and down-bending states. The changes of silver nanowires after sintering were characterized using x-ray photoelectron spectroscopy and transmission electron microscopy and a sintering mechanism was proposed and validated. This direct-written silver nanowire electrode with good performance has broad applications in flexible electronics fabrication and packaging.

A cost-effective nanoporous ultrathin film electrode based on nanoporous gold/IrO2 composite for proton exchange membrane water electrolysis

NASA Astrophysics Data System (ADS)

Zeng, Yachao; Guo, Xiaoqian; Shao, Zhigang; Yu, Hongmei; Song, Wei; Wang, Zhiqiang; Zhang, Hongjie; Yi, Baolian

2017-02-01

A cost-effective nanoporous ultrathin film (NPUF) electrode based on nanoporous gold (NPG)/IrO2 composite has been constructed for proton exchange membrane (PEM) water electrolysis. The electrode was fabricated by integrating IrO2 nanoparticles into NPG through a facile dealloying and thermal decomposition method. The NPUF electrode is featured in its 3D interconnected nanoporosity and ultrathin thickness. The nanoporous ultrathin architecture is binder-free and beneficial for improving electrochemical active surface area, enhancing mass transport and facilitating releasing of oxygen produced during water electrolysis. Serving as anode, a single cell performance of 1.728 V (@ 2 A cm-2) has been achieved by NPUF electrode with a loading of IrO2 and Au at 86.43 and 100.0 μg cm-2 respectively, the electrolysis voltage is 58 mV lower than that of conventional electrode with an Ir loading an order of magnitude higher. The electrolysis voltage kept relatively constant up to 300 h (@250 mA cm-2) during the course of durability test, manifesting that NPUF electrode is promising for gas evolution.

An Ion-Selective Electrode/Flow-Injection Analysis Experiment: Determination of Potassium in Serum.

ERIC Educational Resources Information Center

Meyerhoff, Mark E.; Kovach, Paul M.

1983-01-01

Describes a low-cost, senior-level, instrumental analysis experiment in which a home-made potassium tubular flow-through electrode is constructed and incorporated into a flow injection analysis system (FIA). Also describes experiments for evaluating the electrode's response properties, examining basic FIA concepts, and determining potassium in…

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors

PubMed Central

Ning, Honglong; Chen, Jianqiu; Fang, Zhiqiang; Tao, Ruiqiang; Cai, Wei; Yao, Rihui; Hu, Shiben; Zhu, Zhennan; Zhou, Yicong; Yang, Caigui; Peng, Junbiao

2017-01-01

Printing technologies for thin-film transistors (TFTs) have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium–gallium–zinc–oxide (a-IGZO) TFTs with good electrical performance. In this paper, silver (Ag) source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm2·V−1·s−1 and an on/off current ratio of over 105. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance. PMID:28772410

Direct Inkjet Printing of Silver Source/Drain Electrodes on an Amorphous InGaZnO Layer for Thin-Film Transistors.

PubMed

Ning, Honglong; Chen, Jianqiu; Fang, Zhiqiang; Tao, Ruiqiang; Cai, Wei; Yao, Rihui; Hu, Shiben; Zhu, Zhennan; Zhou, Yicong; Yang, Caigui; Peng, Junbiao

2017-01-10

Printing technologies for thin-film transistors (TFTs) have recently attracted much interest owing to their eco-friendliness, direct patterning, low cost, and roll-to-roll manufacturing processes. Lower production costs could result if electrodes fabricated by vacuum processes could be replaced by inkjet printing. However, poor interfacial contacts and/or serious diffusion between the active layer and the silver electrodes are still problematic for achieving amorphous indium-gallium-zinc-oxide (a-IGZO) TFTs with good electrical performance. In this paper, silver (Ag) source/drain electrodes were directly inkjet-printed on an amorphous a-IGZO layer to fabricate TFTs that exhibited a mobility of 0.29 cm²·V -1 ·s -1 and an on/off current ratio of over 10⁵. To the best of our knowledge, this is a major improvement for bottom-gate top-contact a-IGZO TFTs with directly printed silver electrodes on a substrate with no pretreatment. This study presents a promising alternative method of fabricating electrodes of a-IGZO TFTs with desirable device performance.

High performance polymer chemical hydrogel-based electrode binder materials for direct borohydride fuel cells

NASA Astrophysics Data System (ADS)

Choudhury, Nurul A.; Ma, Jia; Sahai, Yogeshwar; Buchheit, Rudolph G.

Novel, cost-effective, high-performance, and environment-friendly electrode binders, comprising polyvinyl alcohol chemical hydrogel (PCH) and chitosan chemical hydrogel (CCH), are reported for direct borohydride fuel cells (DBFCs). PCH and CCH binders-based electrodes have been fabricated using a novel, simple, cost-effective, time-effective, and environmentally benign technique. Morphologies and electrochemical performance in DBFCs of the chemical hydrogel binder-based electrodes have been compared with those of Nafion ® binder-based electrodes. Relationships between the performance of binders in DBFCs with structural features of the polymers and the polymer-based chemical hydrogels are discussed. The CCH binder exhibited better performance than a Nafion ® binder whereas the PCH binder exhibited comparable performance to Nafion ® in DBFCs operating at elevated cell temperatures. The better performance of CCH binder at higher operating cell temperatures has been ascribed to the hydrophilic nature and water retention characteristics of chitosan. DBFCs employing CCH binder-based electrodes and a Nafion ®-117 membrane as an electrolyte exhibited a maximum peak power density of about 589 mW cm -2 at 70 °C.

Comparison of unusual carbon-based working electrodes for electrochemiluminescence sensors.

PubMed

Noman, Muhammad; Sanginario, Alessandro; Jagadale, Pravin; Demarchi, Danilo; Tagliaferro, Alberto

2017-06-01

In this work, unconventional carbon-based materials were investigated for use in electrochemiluminescence (ECL) working electrodes. Precursors such as bamboo, pistachio shells, kevlar ® fibers and camphor were differently treated and used as working electrodes in ECL experiments. After a proper process they were assembled as electrodes and tested in an electrochemical cell. Comparison among them and with a commercial glassy carbon electrode (GCE) shows a very good response for all of them thus demonstrating their potential use as disposable low-cost electrodes for early detection electrochemical analysis. Copyright © 2017 Elsevier B.V. All rights reserved.

Hybrid system for rechargeable magnesium battery with high energy density

NASA Astrophysics Data System (ADS)

Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

2015-07-01

One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries.

Converting Corncob to Activated Porous Carbon for Supercapacitor Application.

PubMed

Yang, Shaoran; Zhang, Kaili

2018-03-21

Carbon materials derived from biomass are promising electrode materials for supercapacitor application due to their specific porosity, low cost and electrochemical stability. Herein, a hierarchical porous carbon derived from corncob was developed for use as electrodes. Benefitting from its hierarchical porosity, inherited from the natural structure of corncob, high BET surface area (1471.4 m²·g -1 ) and excellent electrical conductivity, the novel carbon material exhibited a specific capacitance of 293 F·g -1 at 1 A·g -1 in 6 M KOH electrolyte and maintained at 195 F·g -1 at 5 A·g -1 . In addition, a two-electrode device was assembled and delivered an energy density of 20.15 Wh·kg -1 at a power density of 500 W·kg -1 and an outstanding stability of 99.9% capacitance retention after 4000 cycles.

Power sources for portable electronics and hybrid cars: lithium batteries and fuel cells.

PubMed

Scrosati, Bruno

2005-01-01

The activities in progress in our laboratory for the development of batteries and fuel cells for portable electronics and hybrid car applications are reviewed and discussed. In the case of lithium batteries, the research has been mainly focused on the characterization of new electrode and electrolyte materials. Results related to disordered carbon anodes and improved, solvent-free, as well as gel-type, polymer electrolytes are particularly stressed. It is shown that the use of proper gel electrolytes, in combination with suitable electrode couples, allows the development of new types of safe, reliable, and low-cost lithium ion batteries which appear to be very promising power sources for hybrid vehicles. Some of the technologies proven to be successful in the lithium battery area are readapted for use in fuel cells. In particular, this approach has been followed for the preparation of low-cost and stable protonic membranes to be proposed as an alternative to the expensive, perfluorosulfonic membranes presently used in polymer electrolyte membrane fuel cells (PEMFCs). Copyright 2005 The Japan Chemical Journal Forum and Wiley Periodicals, Inc

Understanding electrical conduction in lithium ion batteries through multi-scale modeling

NASA Astrophysics Data System (ADS)

Pan, Jie

Silicon (Si) has been considered as a promising negative electrode material for lithium ion batteries (LIBs) because of its high theoretical capacity, low discharge voltage, and low cost. However, the utilization of Si electrode has been hampered by problems such as slow ionic transport, large stress/strain generation, and unstable solid electrolyte interphase (SEI). These problems severely influence the performance and cycle life of Si electrodes. In general, ionic conduction determines the rate performance of the electrode, while electron leakage through the SEI causes electrolyte decomposition and, thus, causes capacity loss. The goal of this thesis research is to design Si electrodes with high current efficiency and durability through a fundamental understanding of the ionic and electronic conduction in Si and its SEI. Multi-scale physical and chemical processes occur in the electrode during charging and discharging. This thesis, thus, focuses on multi-scale modeling, including developing new methods, to help understand these coupled physical and chemical processes. For example, we developed a new method based on ab initio molecular dynamics to study the effects of stress/strain on Li ion transport in amorphous lithiated Si electrodes. This method not only quantitatively shows the effect of stress on ionic transport in amorphous materials, but also uncovers the underlying atomistic mechanisms. However, the origin of ionic conduction in the inorganic components in SEI is different from that in the amorphous Si electrode. To tackle this problem, we developed a model by separating the problem into two scales: 1) atomistic scale: defect physics and transport in individual SEI components with consideration of the environment, e.g., LiF in equilibrium with Si electrode; 2) mesoscopic scale: defect distribution near the heterogeneous interface based on a space charge model. In addition, to help design better artificial SEI, we further demonstrated a theoretical design of multicomponent SEIs by utilizing the synergetic effect found in the natural SEI. We show that the electrical conduction can be optimized by varying the grain size and volume fraction of two phases in the artificial multicomponent SEI.

7Li MRI of Li batteries reveals location of microstructural lithium.

PubMed

Chandrashekar, S; Trease, Nicole M; Chang, Hee Jung; Du, Lin-Shu; Grey, Clare P; Jerschow, Alexej

2012-02-12

There is an ever-increasing need for advanced batteries for portable electronics, to power electric vehicles and to facilitate the distribution and storage of energy derived from renewable energy sources. The increasing demands on batteries and other electrochemical devices have spurred research into the development of new electrode materials that could lead to better performance and lower cost (increased capacity, stability and cycle life, and safety). These developments have, in turn, given rise to a vigorous search for the development of robust and reliable diagnostic tools to monitor and analyse battery performance, where possible, in situ. Yet, a proven, convenient and non-invasive technology, with an ability to image in three dimensions the chemical changes that occur inside a full battery as it cycles, has yet to emerge. Here we demonstrate techniques based on magnetic resonance imaging, which enable a completely non-invasive visualization and characterization of the changes that occur on battery electrodes and in the electrolyte. The current application focuses on lithium-metal batteries and the observation of electrode microstructure build-up as a result of charging. The methods developed here will be highly valuable in the quest for enhanced battery performance and in the evaluation of other electrochemical devices.

7Li MRI of Li batteries reveals location of microstructural lithium

NASA Astrophysics Data System (ADS)

Chandrashekar, S.; Trease, Nicole M.; Chang, Hee Jung; Du, Lin-Shu; Grey, Clare P.; Jerschow, Alexej

2012-04-01

There is an ever-increasing need for advanced batteries for portable electronics, to power electric vehicles and to facilitate the distribution and storage of energy derived from renewable energy sources. The increasing demands on batteries and other electrochemical devices have spurred research into the development of new electrode materials that could lead to better performance and lower cost (increased capacity, stability and cycle life, and safety). These developments have, in turn, given rise to a vigorous search for the development of robust and reliable diagnostic tools to monitor and analyse battery performance, where possible, in situ. Yet, a proven, convenient and non-invasive technology, with an ability to image in three dimensions the chemical changes that occur inside a full battery as it cycles, has yet to emerge. Here we demonstrate techniques based on magnetic resonance imaging, which enable a completely non-invasive visualization and characterization of the changes that occur on battery electrodes and in the electrolyte. The current application focuses on lithium-metal batteries and the observation of electrode microstructure build-up as a result of charging. The methods developed here will be highly valuable in the quest for enhanced battery performance and in the evaluation of other electrochemical devices.

Batteries for storage of wind-generated energy

NASA Technical Reports Server (NTRS)

Schwartz, H. J.

1973-01-01

Cost effectiveness characteristics of conventional-, metal gas-, and high energy alkali metal-batteries for wind generated energy storage are considered. A lead-acid battery with a power density of 20 to 30 watt/hours per pound is good for about 1500 charge-discharge cycles at a cost of about $80 per kilowatt hour. A zinc-chlorine battery that stores chlorine as solid chlorine hydrate at temperatures below 10 C eliminates the need to handle gaseous chlorine; its raw material cost are low and inexpensive carbon can be used for the chlorine electrode. This system has the best chance to replace lead-acid. Exotic alkali metal batteries are deemed too costly at the present stage of development.

Advanced Architectures and Relatives of Air Electrodes in Zn–Air Batteries

PubMed Central

Pan, Jing; Xu, Yang Yang; Yang, Huan; Dong, Zehua; Liu, Hongfang

2018-01-01

Abstract Zn–air batteries are becoming the promising power sources for portable and wearable electronic devices and hybrid/electric vehicles because of their high specific energy density and the low cost for next‐generation green and sustainable energy technologies. An air electrode integrated with an oxygen electrocatalyst is the most important component and inevitably determines the performance and cost of a Zn–air battery. This article presents exciting advances and challenges related to air electrodes and their relatives. After a brief introduction of the Zn–air battery, the architectures and oxygen electrocatalysts of air electrodes and relevant electrolytes are highlighted in primary and rechargeable types with different configurations, respectively. Moreover, the individual components and major issues of flexible Zn–air batteries are also highlighted, along with the strategies to enhance the battery performance. Finally, a perspective for design, preparation, and assembly of air electrodes is proposed for the future innovations of Zn–air batteries with high performance. PMID:29721418

The rise of organic electrode materials for energy storage.

PubMed

Schon, Tyler B; McAllister, Bryony T; Li, Peng-Fei; Seferos, Dwight S

2016-11-07

Organic electrode materials are very attractive for electrochemical energy storage devices because they can be flexible, lightweight, low cost, benign to the environment, and used in a variety of device architectures. They are not mere alternatives to more traditional energy storage materials, rather, they have the potential to lead to disruptive technologies. Although organic electrode materials for energy storage have progressed in recent years, there are still significant challenges to overcome before reaching large-scale commercialization. This review provides an overview of energy storage systems as a whole, the metrics that are used to quantify the performance of electrodes, recent strategies that have been investigated to overcome the challenges associated with organic electrode materials, and the use of computational chemistry to design and study new materials and their properties. Design strategies are examined to overcome issues with capacity/capacitance, device voltage, rate capability, and cycling stability in order to guide future work in the area. The use of low cost materials is highlighted as a direction towards commercial realization.

A Facile Electrophoretic Deposition Route to the Fe3O4/CNTs/rGO Composite Electrode as a Binder-Free Anode for Lithium Ion Battery.

PubMed

Yang, Yang; Li, Jiaqi; Chen, Dingqiong; Zhao, Jinbao

2016-10-12

Fe 3 O 4 is regarded as an attractive anode material for lithium ion batteries (LIBs) due to its high theoretical capacity, natural abundance, and low cost. However, the poor cyclic performance resulting from the low conductivity and huge volume change during cycling impedes its application. Here we have developed a facile electrophoretic deposition route to fabricate the Fe 3 O 4 /CNTs (carbon nanotubes)/rGO (reduced graphene oxide) composite electrode, simultaneously achieving material synthesis and electrode assembling. Even without binders, the adhesion and mechanical firmness of the electrode are strong enough to be used for LIB anode. In this specific structure, Fe 3 O 4 nanoparticles (NPs) interconnected by CNTs are sandwiched by rGO layers to form a robust network with good conductivity. The resulting Fe 3 O 4 /CNTs/rGO composite electrode exhibits much improved electrochemical performance (high reversible capacity of 540 mAh g -1 at a very high current density of 10 A g -1 , and a remarkable capacity of 1080 mAh g -1 can be maintained after 450 cycles at 1 A g -1 ) compared with that of commercial Fe 3 O 4 NPs electrode.

Bioinspired fractal electrodes for solar energy storages.

PubMed

Thekkekara, Litty V; Gu, Min

2017-03-31

Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10 -3  Whcm -3 . In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10 -1  Whcm -3 - more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications.

Bioinspired fractal electrodes for solar energy storages

PubMed Central

Thekkekara, Litty V.; Gu, Min

2017-01-01

Solar energy storage is an emerging technology which can promote the solar energy as the primary source of electricity. Recent development of laser scribed graphene electrodes exhibiting a high electrical conductivity have enabled a green technology platform for supercapacitor-based energy storage, resulting in cost-effective, environment-friendly features, and consequent readiness for on-chip integration. Due to the limitation of the ion-accessible active porous surface area, the energy densities of these supercapacitors are restricted below ~3 × 10−3 Whcm−3. In this paper, we demonstrate a new design of biomimetic laser scribed graphene electrodes for solar energy storage, which embraces the structure of Fern leaves characterized by the geometric family of space filling curves of fractals. This new conceptual design removes the limit of the conventional planar supercapacitors by significantly increasing the ratio of active surface area to volume of the new electrodes and reducing the electrolyte ionic path. The attained energy density is thus significantly increased to ~10−1 Whcm−3- more than 30 times higher than that achievable by the planar electrodes with ~95% coulombic efficiency of the solar energy storage. The energy storages with these novel electrodes open the prospects of efficient self-powered and solar-powered wearable, flexible and portable applications. PMID:28361924

Pin-based electrochemical glucose sensor with multiplexing possibilities.

PubMed

Rama, Estefanía C; Costa-García, Agustín; Fernández-Abedul, M Teresa

2017-02-15

This work describes the use of mass-produced stainless-steel pins as low-cost electrodes to develop simple and portable amperometric glucose biosensors. A potentiostatic three-electrode configuration device is designed using two bare pins as reference and counter electrodes, and a carbon-ink coated pin as working electrode. Conventional transparency film without any pretreatment is used to punch the pins and contain the measurement solution. The interface to the potentiostat is very simple since it is based on a commercial female connection. This electrochemical system is applied to glucose determination using a bienzymatic sensor phase (glucose oxidase/horseradish peroxidase) with ferrocyanide as electron-transfer mediator, achieving a linear range from 0.05 to 1mM. It shows analytical characteristics comparable to glucose sensors previously reported using conventional electrodes, and its application for real food samples provides good results. The easy modification of the position of the pins allows designing different configurations with possibility of performing simultaneous measurements. This is demonstrated through a specific design that includes four pin working-electrodes. Different concentrations of antibody labeled with alkaline phosphatase are immobilized on the pin-heads and after enzymatic conversion of 3-indoxylphosphate and silver nitrate, metallic silver is determined by anodic stripping voltammetry. Copyright © 2016 Elsevier B.V. All rights reserved.

Amorphous Ni(Fe)OxHy-coated nanocone arrays self-supported on stainless steel mesh as a promising oxygen-evolving anode for large scale water splitting

NASA Astrophysics Data System (ADS)

Shen, Junyu; Wang, Mei; Zhao, Liang; Zhang, Peili; Jiang, Jian; Liu, Jinxuan

2018-06-01

The development of highly efficient, robust, and cheap water oxidation electrodes is a major challenge in constructing industrially applicable electrolyzers for large-scale production of hydrogen from water. Herein we report a hierarchical stainless steel mesh electrode which features Ni(Fe)OxHy-coated self-supported nanocone arrays. Through a facile, mild, low-cost and readily scalable two-step fabrication procedure, the electrochemically active area of the optimized electrode is enlarged by a factor of 3.1 and the specific activity is enhanced by a factor of 250 at 265 mV overpotential compared with that of a corresponding pristine stainless steel mesh electrode. Moreover, the charge-transfer resistance is reduced from 4.47 Ω for the stainless steel mesh electrode to 0.13 Ω for the Ni(Fe)OxHy-coated nanocone array stainless steel mesh electrode. As a result, the cheap and easily fabricated electrode displays 280 and 303 mV low overpotentials to achieve high current densities of 500 and 1000 mA cmgeo-2, respectively, for oxygen evolution reaction in 1 M KOH. More importantly, the electrode exhibits a good stability over 340 h of chronopotentiometric test at 50 mA cmgeo-2 and only a slight attenuation (4.2%, ∼15 mV) in catalytic activity over 82 h electrolysis at a constant current density of 500 mA cmgeo-2.

Catalyst and electrode research for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Antoine, A. C.; King, R. B.

1987-01-01

An account is given of the development status of phosphoric acid fuel cells' high performance catalyst and electrode materials. Binary alloys have been identified which outperform the baseline platinum catalyst; it has also become apparent that pressurized operation is required to reach the desired efficiencies, calling in turn for the use of graphitized carbon blacks in the role of catalyst supports. Efforts to improve cell performance and reduce catalyst costs have led to the investigation of a class of organometallic cathode catalysts represented by the tetraazaannulenes, and a mixed catalyst which is a mixture of carbons catalyzed with an organometallic and a noble metal.

A LabVIEW based experiment system for the efficient collection and analysis of cyclic voltametry and electrode charge capacity measurements.

PubMed

Detlefsen, D; Hu, Z; Troyk, P R

2006-01-01

Cyclic voltametry and recording of stimulation electrode voltage excursions are two critical methods of measurement for understanding the performance of implantable electrodes. Because implanted electrodes cannot easily be replaced, it is necessary to have an a-priori understanding of an electrode's implanted performance and capabilities. In-vitro exhaustive tests are often needed to quantify an electrodes performance. Using commonly available equipment, the human labor cost to conduct this work is immense. Presented is an automated experiment system that is highly configurable that can efficiently conduct a battery of repeatable CV and stimulation recording measurements. Results of preparing 96 electrodes prior to an animal implantation are also discussed.

Hand-drawn&written pen-on-paper electrochemiluminescence immunodevice powered by rechargeable battery for low-cost point-of-care testing.

PubMed

Yang, Hongmei; Kong, Qingkun; Wang, Shaowei; Xu, Jinmeng; Bian, Zhaoquan; Zheng, Xiaoxiao; Ma, Chao; Ge, Shenguang; Yu, Jinghua

2014-11-15

In this paper, a pen-on-paper electrochemiluminescence (PoP-ECL) device was entirely hand drawn and written in commercially available crayon and pencil in turn for the first time, and a constant potential-triggered sandwich-type immunosensor was introduced into the PoP-ECL device to form a low-cost ECL immunodevice proof. Each PoP-ECL device contained a hydrophilic paper channel and two PoP electrodes, and the PoP-ECL device was produced as follows: crayon was firstly used to draw hydrophobic regions on pure cellulose paper to create the hydrophilic paper channels followed with a baking treatment, and then a 6B-type black pencil with low resistivity was applied for precision writing, as the PoP electrodes, across the hydrophilic paper channel. For further point-of-care testing, a portable, low-cost rechargeable battery was employed as the power source to provide constant potential to the PoP electrodes to trigger the ECL. Using Carbohydrate antigen 199 as model analyte, this PoP-ECL immunodevice showed a good linear response range from 0.01-200 U mL(-1) with a detection limit of 0.0055 U mL(-1), a high sensitivity and stability. The proposed PoP-ECL immunodevice could be used in point-of-care testing of other tumor markers for remote regions and developing countries. Copyright © 2014 Elsevier B.V. All rights reserved.

Point-of-need simultaneous electrochemical detection of lead and cadmium using low-cost stencil-printed transparency electrodes.

PubMed

Martín-Yerga, Daniel; Álvarez-Martos, Isabel; Blanco-López, M Carmen; Henry, Charles S; Fernández-Abedul, M Teresa

2017-08-15

In this work, we report a simple and yet efficient stencil-printed electrochemical platform that can be integrated into the caps of sample containers and thus, allows in-field quantification of Cd(II) and Pb(II) in river water samples. The device exploits the low-cost features of carbon (as electrode material) and paper/polyester transparency sheets (as substrate). Electrochemical analysis of the working electrodes prepared on different substrates (polyester transparency sheets, chromatographic, tracing and office papers) with hexaammineruthenium(III) showed that their electroactive area and electron transfer kinetics are highly affected by the porosity of the material. Electrodes prepared on transparency substrates showed the best electroanalytical performance for the simultaneous determination of Cd(II) and Pb(II) by square-wave anodic stripping voltammetry. Interestingly, the temperature and time at which the carbon ink was cured had significant effect on the electrochemical response, especially the capacitive current. The amount of Cd and Pb on the electrode surface can be increased about 20% by in situ electrodeposition of bismuth. The electrochemical platform showed a linear range comprised between 1 and 200 μg/L for both metals, sensitivity of analysis of 0.22 and 0.087 μA/ppb and limits of detection of 0.2 and 0.3 μg/L for Cd(II) and Pb(II), respectively. The analysis of river water samples was done directly in the container where the sample was collected, which simplifies the procedure and approaches field analysis. The developed point-of-need detection system allowed simultaneous determination of Cd(II) and Pb(II) in those samples using the standard addition method with precise and accurate results. Copyright © 2017 Elsevier B.V. All rights reserved.

Epitaxial-Growth-Induced Junction Welding of Silver Nanowire Network Electrodes.

PubMed

Kang, Hyungseok; Song, Sol-Ji; Sul, Young Eun; An, Byeong-Seon; Yin, Zhenxing; Choi, Yongsuk; Pu, Lyongsun; Yang, Cheol-Woong; Kim, Youn Sang; Cho, Sung Min; Kim, Jung-Gu; Cho, Jeong Ho

2018-05-22

In this study, we developed a roll-to-roll Ag electroplating process for metallic nanowire electrodes using a galvanostatic mode. Electroplating is a low-cost and facile method for deposition of metal onto a target surface with precise control of both the composition and the thickness. Metallic nanowire networks [silver nanowires (AgNWs) and copper nanowires (CuNWs)] coated onto a polyethylene terephthalate (PET) film were immersed directly in an electroplating bath containing AgNO 3 . Solvated silver ions (Ag + ions) were deposited onto the nanowire surface through application of a constant current via an external circuit between the nanowire networks (cathode) and a Ag plate (anode). The amount of electroplated Ag was systematically controlled by changing both the applied current density and the electroplating time, which enabled precise control of the sheet resistance and optical transmittance of the metallic nanowire networks. The optimized Ag-electroplated AgNW (Ag-AgNW) films exhibited a sheet resistance of ∼19 Ω/sq at an optical transmittance of 90% (550 nm). A transmission electron microscopy study confirmed that Ag grew epitaxially on the AgNW surface, but a polycrystalline Ag structure was formed on the CuNW surface. The Ag-electroplated metallic nanowire electrodes were successfully applied to various electronic devices such as organic light-emitting diodes, triboelectric nanogenerators, and a resistive touch panel. The proposed roll-to-roll Ag electroplating process provides a simple, low-cost, and scalable method for the fabrication of enhanced transparent conductive electrode materials for next-generation electronic devices.

Composite electrodes for advanced electrochemical applications. Quarterly report for the period October 1, - December 31, 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovach, Chris

The electrochemical industry is one of the most highly energy intensive industries today. However, there have been no significant advances in the electrodes that these industries use. The dimensionally stable anode (DSA), which ELTECH introduced under a license agreement, has been the industry standard for the past twenty-five years. But, DSAs are nearing the end of their technological prevalence. The principal problems with DSAs include high capital and operating costs, and the proprietary nature of the technology. In addition, DSAs experience problems that include: contamination of the process solution by anode materials, failure when the electrocatalytic coating peels from underattack,more » generally low anode performance due to inherent limitations in operating current density, and short anode lifetime because of corrosion. The proposed innovation combines the low electrical resistance of copper with the corrosion resistance of electrically conductive diamond to achieve energy efficient, long-lifetime electrodes for electrochemistry. The proposed work will ultimately develop a composite electrode that consists of a copper substrate, a conductive diamond coating, and a catalytic precious metal coating. The scope of the current work includes preparation, testing, and evaluation of diamond-coated titanium electrodes.« less

Composite electrodes for advanced electrochemical applications. Quarterly report for the period July 1 - September 30, 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kovach, Chris

The electrochemical industry is one of the most highly energy-intensive industries today. However, there have been no significant advances in the electrodes that these industries use. The dimensionally stable anode (DSA), which ELTECH introduced under a license agreement, has been the industry standard for the past twenty-five years. But, DSAs are nearing the end of their technological prevalence. The principal problems with DSAs include high capital and operating cost, and the proprietary nature of the technology. In addition, DSAs experience problems that include contamination of the process solution by anode materials, failure when the electrocatalytic coating peels from under attack,more » generally low anode performance due to inherent limitations in operating current density, and short anode lifetime because of corrosion. The proposed innovation combines the low electrical resistance of copper with the corrosion resistance of electrically conductive diamond to achieve energy-efficient, long-lifetime electrodes for electrochemistry. The proposed work will ultimately develop a composite electrode that consists of a copper substrate, a conductive diamond coating, and a catalytic precious metal coating. The scope of the current work includes preparation, testing, and evaluation of diamond-coated titanium electrodes.« less

Direct laser-patterned micro-supercapacitors from paintable MoS2 films.

PubMed

Cao, Liujun; Yang, Shubin; Gao, Wei; Liu, Zheng; Gong, Yongji; Ma, Lulu; Shi, Gang; Lei, Sidong; Zhang, Yunhuai; Zhang, Shengtao; Vajtai, Robert; Ajayan, Pulickel M

2013-09-09

Micrometer-sized electrochemical capacitors have recently attracted attention due to their possible applications in micro-electronic devices. Here, a new approach to large-scale fabrication of high-capacitance, two-dimensional MoS2 film-based micro-supercapacitors is demonstrated via simple and low-cost spray painting of MoS2 nanosheets on Si/SiO2 chip and subsequent laser patterning. The obtained micro-supercapacitors are well defined by ten interdigitated electrodes (five electrodes per polarity) with 4.5 mm length, 820 μm wide for each electrode, 200 μm spacing between two electrodes and the thickness of electrode is ∼0.45 μm. The optimum MoS2 -based micro-supercapacitor exhibits excellent electrochemical performance for energy storage with aqueous electrolytes, with a high area capacitance of 8 mF cm(-2) (volumetric capacitance of 178 F cm(-3) ) and excellent cyclic performance, superior to reported graphene-based micro-supercapacitors. This strategy could provide a good opportunity to develop various micro-/nanosized energy storage devices to satisfy the requirements of portable, flexible, and transparent micro-electronic devices. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Graphene electrodes for lithium-niobate electro-optic devices.

PubMed

Chang, Zeshan; Jin, Wei; Chiang, Kin Seng

2018-04-15

We propose and demonstrate the use of graphene electrodes for lithium-niobate electro-optic (EO) devices to exempt the need of incorporating a buffer layer between the waveguide and the electrodes. Using graphene electrodes, our experimental mode converter, based on an EO-generated long-period grating in a LiNbO 3 waveguide, shows a reduction in the half-π voltage by almost three times, compared with the conventional electrode design using metal. With the buffer layer exempted, the device fabrication process is also significantly simplified. The use of graphene electrodes is an effective approach to enhancing the efficiency of EO devices and, at the same time, reducing their fabrication cost.

Low-Cost Flexible Nano-Sulfide/Carbon Composite Counter Electrode for Quantum-Dot-Sensitized Solar Cell

PubMed Central

2010-01-01

Cu2S nanocrystal particles were in situ deposited on graphite paper to prepare nano-sulfide/carbon composite counter electrode for CdS/CdSe quantum-dot-sensitized solar cell (QDSC). By optimization of deposition time, photovoltaic conversion efficiency up to 3.08% was obtained. In the meantime, this composite counter electrode was superior to the commonly used Pt, Au and carbon counter electrodes. Electrochemical impedance spectra further confirmed that low charge transfer resistance at counter electrode/electrolyte interface was responsible for this, implied the potential application of this composite counter electrode in high-efficiency QDSC. PMID:20672135

A review on cellulose and lignin based binders and electrodes: Small steps towards a sustainable lithium ion battery.

PubMed

Nirmale, Trupti C; Kale, Bharat B; Varma, Anjani J

2017-10-01

Lithium ion batteries (LIB) are the most promising energy storage systems for portable electronics and future electric or hybrid-electric vehicles. However making them safer, cost effective and environment friendly is the key challenge. In this regard, replacing petro-derived materials by introducing renewable biomass derived cellulose derivatives and lignin based materials into the battery system is a promising approach for the development of green materials for LIB. These biomaterials introduce sustainability as well as improved safety in the final disposal of LIB batteries. In this review we introduce LIB materials technology in brief and recent developments in electrodes and binders based on cellulose and their derivatives and lignin for lithium ion batteries. Copyright © 2017 Elsevier B.V. All rights reserved.

Method for intercalating alkali metal ions into carbon electrodes

DOEpatents

Doeff, Marca M.; Ma, Yanping; Visco, Steven J.; DeJonghe, Lutgard

1995-01-01

A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

Method for intercalating alkali metal ions into carbon electrodes

DOEpatents

Doeff, M.M.; Ma, Y.; Visco, S.J.; DeJonghe, L.

1995-08-22

A low cost, relatively flexible, carbon electrode for use in a secondary battery is described. A method is provided for producing same, including intercalating alkali metal salts such as sodium and lithium into carbon.

A low-cost, multiplexed μECoG system for high-density recordings in freely moving rodents

NASA Astrophysics Data System (ADS)

Insanally, Michele; Trumpis, Michael; Wang, Charles; Chiang, Chia-Han; Woods, Virginia; Palopoli-Trojani, Kay; Bossi, Silvia; Froemke, Robert C.; Viventi, Jonathan

2016-04-01

Objective. Micro-electrocorticography (μECoG) offers a minimally invasive neural interface with high spatial resolution over large areas of cortex. However, electrode arrays with many contacts that are individually wired to external recording systems are cumbersome and make recordings in freely behaving rodents challenging. We report a novel high-density 60-electrode system for μECoG recording in freely moving rats. Approach. Multiplexed headstages overcome the problem of wiring complexity by combining signals from many electrodes to a smaller number of connections. We have developed a low-cost, multiplexed recording system with 60 contacts at 406 μm spacing. We characterized the quality of the electrode signals using multiple metrics that tracked spatial variation, evoked-response detectability, and decoding value. Performance of the system was validated both in anesthetized animals and freely moving awake animals. Main results. We recorded μECoG signals over the primary auditory cortex, measuring responses to acoustic stimuli across all channels. Single-trial responses had high signal-to-noise ratios (SNR) (up to 25 dB under anesthesia), and were used to rapidly measure network topography within ˜10 s by constructing all single-channel receptive fields in parallel. We characterized evoked potential amplitudes and spatial correlations across the array in the anesthetized and awake animals. Recording quality in awake animals was stable for at least 30 days. Finally, we used these responses to accurately decode auditory stimuli on single trials. Significance. This study introduces (1) a μECoG recording system based on practical hardware design and (2) a rigorous analytical method for characterizing the signal characteristics of μECoG electrode arrays. This methodology can be applied to evaluate the fidelity and lifetime of any μECoG electrode array. Our μECoG-based recording system is accessible and will be useful for studies of perception and decision-making in rodents, particularly over the entire time course of behavioral training and learning.

MnO2-deposited lignin-based carbon nanofiber mats for application as electrodes in symmetric pseudocapacitors.

PubMed

Youe, Won-Jae; Kim, Seok Ju; Lee, Soo-Min; Chun, Sang-Jin; Kang, Juwon; Kim, Yong Sik

2018-06-01

Low-cost, high-performance electrodes are highly attractive for practical supercapacitor applications. MnO 2 -deposited carbon nanofiber mats (MnO 2 -CNFMs) are prepared for use as binder-free supercapacitor electrodes. MnO 2 is deposited on the mats in situ by hydrothermally decomposing aqueous KMnO 4 , leading to the formation of nanocrystals of MnO 2 . The MnO 2 -CNFM electrode produced with 38.0μmol KMnO 4 (this electrode) shows a high specific capacitance of ~171.6F·g -1 at a scan rate of 5mV·s -1 . Moreover, a symmetric supercapacitor with the electrode exhibits a specific capacitance of 67.0F·g -1 , an energy density of 6.0Wh·kg -1 and a power density of 160W·kg -1 at a special current of 0.1A·g -1 . Further, the symmetric supercapacitor displays excellent cycling stability, retains approximately 99% of the capacitance after 1000cycles. The simplicity and ease of preparation of the MnO 2 -CNFMs as well as their suitability for use in coin-type supercapacitor cells make them ideal for application in cost-effective and high-performance electrodes for supercapacitors. Copyright © 2018 Elsevier B.V. All rights reserved.

Cyanex based uranyl sensitive polymeric membrane electrodes.

PubMed

Badr, Ibrahim H A; Zidan, W I; Akl, Z F

2014-01-01

Novel uranyl selective polymeric membrane electrodes were prepared using three different low-cost and commercially available Cyanex extractants namely, bis(2,4,4-trimethylpentyl) phosphinic acid [L1], bis(2,4,4-trimethylpentyl) monothiophosphinic acid [L2] and bis(2,4,4-trimethylpentyl) dithiophosphinic acid [L3]. Optimization and performance characteristics of the developed Cyanex based polymer membrane electrodes were determined. The influence of membrane composition (e.g., amount and type of ionic sites, as well as type of plasticizer) on potentiometric responses of the prepared membrane electrodes was studied. Optimized Cyanex-based membrane electrodes exhibited Nernstian responses for UO₂(2+) ion over wide concentration ranges with fast response times. The optimized membrane electrodes based on L1, L2 and L3 exhibited Nernstian responses towards uranyl ion with slopes of 29.4, 28.0 and 29.3 mV decade(-1), respectively. The optimized membrane electrodes based on L1-L3 showed detection limits of 8.3 × 10(-5), 3.0 × 10(-5) and 3.3 × 10(-6) mol L(-1), respectively. The selectivity studies showed that the optimized membrane electrodes exhibited high selectivity towards UO₂(2+) ion over large number of other cations. Membrane electrodes based on L3 exhibited superior potentiometric response characteristics compared to those based on L1 and L2 (e.g., widest linear range and lowest detection limit). The analytical utility of uranyl membrane electrodes formulated with Cyanex extractant L3 was demonstrated by the analysis of uranyl ion in different real samples for nuclear safeguards verification purposes. The results obtained using direct potentiometry and flow-injection methods were compared with those measured using the standard UV-visible and inductively coupled plasma spectroscopic methods. © 2013 Published by Elsevier B.V.

Development of Polybenzimidazole-Based High-Temperature Membrane and Electrode Assemblies for Stationary and Automotive Applications

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogel, John A.

The program began on August 1, 2003 and ended on July 31, 2007. The goal of the project was to optimize a high-temperature polybenzimidazole (PBI) membrane to meet the performance, durability, and cost targets required for stationary fuel cell applications. These targets were identified in the Fuel Cell section (3.4) of DOE’s Hydrogen, Fuel Cells and Infrastructure Technologies Program Multi-Year Research, Development and Demonstration Plan. A membrane that operates at high temperatures is important to the fuel cell industry because it is insensitive to carbon monoxide (a poison to low-temperature fuel cells), and does not require complex water management strategies.more » Together, these two benefits greatly simplify the fuel cell system. As a result, the high-temperature fuel cell system realizes a cost benefit as the number of components is reduced by nearly 30%. There is also an inherent reliability benefit as components such as humidifiers and pumps for water management are unnecessary. Furthermore, combined heat and power (CHP) systems may be the best solution for a commercial, grid-connected, stationary product that must offer a cost benefit to the end user. For a low-temperature system, the quality of the heat supplied is insufficient to meet consumer needs and comfort requirements, so peak heaters or supplemental boilers are required. The higher operating temperature of PBI technology allows the fuel cell to meet the heat and comfort demand without the additional equipment. Plug Power, working with the Rensselaer Polytechnic Institute (RPI) Polymer Science Laboratory, made significant advances in optimizing the PBI membrane material for operation at temperatures greater than 160oC with a lifetime of 40,000 hours. Supporting hardware such as flow field plates and a novel sealing concept were explored to yield the lower-cost stack assembly and corresponding manufacturing process. Additional work was conducted on acid loss, flow field design and cathode electrode development. Membranes and MEAs were supplied by team member BASF Fuel Cell (formerly PEMEAS), a manufacturer of polymer and fiber. Additional subcontractors Entegris, the University of South Carolina (USC) Fuel Cell Center, and RPI’s Fuel Cell Center conducted activities with regard to stack sealing, acid modeling, and electrode development.« less

Construction of titanium dioxide nanorod/graphite microfiber hybrid electrodes for a high performance electrochemical glucose biosensor

NASA Astrophysics Data System (ADS)

Zhang, Jian; Yu, Xin; Guo, Weibo; Qiu, Jichuan; Mou, Xiaoning; Li, Aixue; Liu, Hong

2016-04-01

The demand for a highly sensitive and selective glucose biosensor which can be used for implantable or on-time monitoring is constantly increasing. In this work, TiO2 nanorods were synthesized in situ on the surface of graphite microfibers to yield TiO2 nanorod/graphite microfiber hybrid electrodes. The TiO2 nanorods not only retain the high activity of the immobilized glucose molecule, but also promote the direct electron transfer process on the electrode surface. As a working electrode in an electrochemical glucose biosensor in a flowing system, the microfiber hybrid electrodes exhibit high sensitivity, selectivity and stability. Due to its simplicity, low cost, high stability, and unique morphology, the TiO2 nanorod/graphite microfiber hybrid electrode is expected to be an excellent candidate for an implantable biosensor or for in situ flow monitoring.The demand for a highly sensitive and selective glucose biosensor which can be used for implantable or on-time monitoring is constantly increasing. In this work, TiO2 nanorods were synthesized in situ on the surface of graphite microfibers to yield TiO2 nanorod/graphite microfiber hybrid electrodes. The TiO2 nanorods not only retain the high activity of the immobilized glucose molecule, but also promote the direct electron transfer process on the electrode surface. As a working electrode in an electrochemical glucose biosensor in a flowing system, the microfiber hybrid electrodes exhibit high sensitivity, selectivity and stability. Due to its simplicity, low cost, high stability, and unique morphology, the TiO2 nanorod/graphite microfiber hybrid electrode is expected to be an excellent candidate for an implantable biosensor or for in situ flow monitoring. Electronic supplementary information (ESI) available. See DOI: 10.1039/c6nr01360k

Commercial phosphoric acid fuel cell system technology development

NASA Technical Reports Server (NTRS)

Prokopius, P. R.; Warshay, M.; Simons, S. N.; King, R. B.

1979-01-01

Reducing cost and increasing reliability were the technology drivers in both the electric utility and on-site integrated energy system applications. The longstanding barrier to the attainment of these goals was materials. Differences in approaches and their technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection, and system design philosophy were discussed.

Opportunistic use of a Foley catheter to provide a common electrocautery with a water-irrigating channel for hepatic parenchymal transection.

PubMed

Yamamoto, Yuzo; Yoshioka, Masato; Watanabe, Go; Uchinami, Hiroshi

2015-11-01

High-tech surgical energy devices that are used during a single surgery have increased in number and the expense for such disposable units is by no means negligible. We developed a handmade water-irrigating monopolar electrocautery using a Foley catheter to perform liver parenchymal transection. A commonly used 20-24 Fr Foley catheter was cut at a length of about 8 cm. The shaft of the 5 mm ball electrode measuring 13.5 cm in length was then inlaid into the urine drainage channel. The target tissues were cauterized without making an eschar, thereby preventing the adhesion of the electrode to the tissues. A ball electrode with our handmade water irrigation sheath can be made in only a few minutes at a very low cost, using common medical supplies and yielding satisfactory effects comparable to the use of specialized high-tech devices.

Asymmetric Supercapacitor for Long-Duration Power Storage

NASA Technical Reports Server (NTRS)

Rangan, Krishnaswamy K.; Sudarshan, Tirumalai S.

2012-01-01

A document discusses a project in which a series of novel hybrid positive electrode materials was developed and tested in asymmetric capacitors with carbon negative electrodes. The electrochemical performance of the hybrid capacitors was characterized by cyclic voltammetry and a DC charge/discharge test. The hybrid capacitor exhibited ideal capacitor behavior with an extended operating voltage of 1.6 V in aqueous electrolyte, and energy density higher than activated carbon-based supercapacitors. Nanostructured MnO2 is a promising material for electrochemical capacitors (ECS) because of its low cost, environmentally friendly nature, and reasonably high specific capacitance. The charge capacity of the capacitors can be further improved by increasing the specific surface area of the MnO2 electrode material. The power density and space radiation stability of the capacitors can be enhanced by coating the MnO2 nanoparticles with conducting polymers. The conducting polymer coating also helps in radiation-hardening the ECS.

Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes

PubMed Central

Oltean, Viorica-Alina; Renault, Stéven; Valvo, Mario; Brandell, Daniel

2016-01-01

In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested. PMID:28773272

Sustainable Materials for Sustainable Energy Storage: Organic Na Electrodes.

PubMed

Oltean, Viorica-Alina; Renault, Stéven; Valvo, Mario; Brandell, Daniel

2016-03-01

In this review, we summarize research efforts to realize Na-based organic materials for novel battery chemistries. Na is a more abundant element than Li, thereby contributing to less costly materials with limited to no geopolitical constraints while organic electrode materials harvested from biomass resources provide the possibility of achieving renewable battery components with low environmental impact during processing and recycling. Together, this can form the basis for truly sustainable electrochemical energy storage. We explore the efforts made on electrode materials of organic salts, primarily carbonyl compounds but also Schiff bases, unsaturated compounds, nitroxides and polymers. Moreover, sodiated carbonaceous materials derived from biomasses and waste products are surveyed. As a conclusion to the review, some shortcomings of the currently investigated materials are highlighted together with the major limitations for future development in this field. Finally, routes to move forward in this direction are suggested.

Hybrid system for rechargeable magnesium battery with high energy density

PubMed Central

Chang, Zheng; Yang, Yaqiong; Wang, Xiaowei; Li, Minxia; Fu, Zhengwen; Wu, Yuping; Holze, Rudolf

2015-01-01

One of the main challenges of electrical energy storage (EES) is the development of environmentally friendly battery systems with high safety and high energy density. Rechargeable Mg batteries have been long considered as one highly promising system due to the use of low cost and dendrite-free magnesium metal. The bottleneck for traditional Mg batteries is to achieve high energy density since their output voltage is below 2.0 V. Here, we report a magnesium battery using Mg in Grignard reagent-based electrolyte as the negative electrode, a lithium intercalation compound in aqueous solution as the positive electrode, and a solid electrolyte as a separator. Its average discharge voltage is 2.1 V with stable discharge platform and good cycling life. The calculated energy density based on the two electrodes is high. These findings open another door to rechargeable magnesium batteries. PMID:26173624

Solvent-free dry powder coating process for low-cost manufacturing of LiNi1/3Mn1/3Co1/3O2 cathodes in lithium-ion batteries

NASA Astrophysics Data System (ADS)

Al-Shroofy, Mohanad; Zhang, Qinglin; Xu, Jiagang; Chen, Tao; Kaur, Aman Preet; Cheng, Yang-Tse

2017-06-01

We report a solvent-free dry powder coating process for making LiNi1/3Mn1/3Co1/3O2 (NMC) positive electrodes in lithium-ion batteries. This process eliminates volatile organic compound emission and reduces thermal curing time from hours to minutes. A mixture of NMC, carbon black, and poly(vinylidene difluoride) was electrostatically sprayed onto an aluminum current collector, forming a uniformly distributed electrode with controllable thickness and porosity. Charge/discharge cycling of the dry-powder-coated electrodes in lithium-ion half cells yielded a discharge specific capacity of 155 mAh g-1 and capacity retention of 80% for more than 300 cycles when the electrodes were tested between 3.0 and 4.3 V at a rate of C/5. The long-term cycling performance and durability of dry-powder coated electrodes are similar to those made by the conventional wet slurry-based method. This solvent-free dry powder coating process is a potentially lower-cost, higher-throughput, and more environmentally friendly manufacturing process compared with the conventional wet slurry-based electrode manufacturing method.

Vacuum-free laminated top electrode with conductive tapes for scalable manufacturing of efficient perovskite solar cells

DOE PAGES

Shao, Yuchuan; Wang, Qi; Dong, Qingfeng; ...

2015-06-25

The efficiency of organometal trihalide perovskites (OTP) solar cells have reached that parity of single crystal silicon, and its nature abundant raw material and solution-process capability promise a bright future for commercialization. However, the vacuum based techniques for metal electrode deposition and additional encapsulation layer increase the cost of the perovskite solar cells dramatically and impede their commercialization process. Here, we report a vacuum-free low temperature lamination technique to fabricate the top electrode by commercial conductive tapes (C-tape). The simple fabrication method yields good quality contact and high efficiency device of 12.7%. The C-tapes also encapsulated the devices effectively, resultingmore » in greatly improved device stability. As a result, the combination of lamination of electrodes and encapsulation layers into a single step significantly reduce the cost of device fabrication.« less

Examining of the segmented electrode use from the viewpoint of the electrolyte volatilizing in molten carbonate fuel cell

NASA Astrophysics Data System (ADS)

Sugiura, Kimihiko; Yamauchi, Makoto; Soga, Masatsugu; Tanimoto, Kazumi

Molten carbonate fuel cells (MCFCs) have entered the pre-commercialization phase, and have been experimentally demonstrated in real world applications, including beer brewery, etc. However, though MCFCs have a high potential and an enough operating experience as an energy supply system, they are not explosively widespread. One of these reasons is cost of cell components. Because the thickness of both electrodes is 0.8 mm and both electrodes are made of porous plates of 1 m 2 of the electrode area, they are often broken by a thermal stress in the sintering process of an electrode and by a worker's carelessness at the cell assembly process. Generally, because these cracking electrodes can potentially cause electrolyte leakage and gas crossover, they are not used to a MCFC stack and are disposed of. Therefore, it made the cost of MCFC be raised. The performance of a cell that uses a mosaic electrode has been evaluated. However, the causal relation between the cracking of an electrode and an electrolyte-leakage has not been yet confirmed. If this causal relationship is elucidated, a cracking electrode or a mosaic electrode can be used to MCFC, such that the cost of MCFC systems would consequently decrease. Therefore, we studied the causal relation between the cracking of an electrode and electrolyte leakage and gas crossover using a visualization technique. In the case of an anode electrode where the centre section of a cell has crack of about 1 mm, the electrolyte leakage from this crack could not be observed by the visualization technique. Moreover, the gas crossover could not be also observed by the visualization technique, and nitrogen in the anode exhaust gas was not detected by a gas chromatography. However, the electrolyte leakage observed from the wet-seal section though the gap between the separator and the electrode was always 1 mm or less. Therefore, electrolyte leakage hardly occurs, even if a cracked anode electrode is installed into the centre section of the cell. On the other hand, although the volatile substance gushes from the wet seal section, the electrolyte leakage/volatilization phenomenon does not occur at the centre of the cell or at the gap between each segmented cathode. The volatile substance in the cathode gas-distributor-channel is composed of the electrolyte mist and the electrolyte volatile substance, and the rate of release is about 2.5 times that of anode side. Although the segmented electrode can be applied to the anode in a MCFC, it cannot be applied to a cathode from the viewpoint of the electrolyte leakage/volatilization.

Development of a portable analyzer with polymer lab-on-a-chip (LOC) for continuous sampling and monitoring of Pb(II).

PubMed

Jang, A; Zou, Z; MacKnight, E; Wu, P M; Kim, I S; Ahn, C H; Bishop, P L

2009-01-01

A new portable analyzer with polymer lab-on-a-chip (LOC) has been designed, fabricated and fully characterized for continuous sampling and monitoring of lead (Pb(II)) in this work. As the working electrodes of the sensor, bismuth (Bi (III)) which allowed the advantage of being more environmentally friendly than traditional mercury drop electrodes was used, while maintaining similar sensitivity and other desirable characteristics. The size of a portable analyzer was 30 cmx23 cmx7 cm, and the weight was around 3 kg. The small size gives the advantage of being portable for field use while not sacrificing portability for accuracy of measurement. Furthermore, the autonomous system developed in coordination with the development of new polymer LOC integrated with electrochemical sensors can provide an innovative way to monitor surface waters in an efficient, cost-effective and sustainable manner.

Electric Pulse Discharge Activated Carbon Supercapacitors for Transportation Application

NASA Astrophysics Data System (ADS)

Nayak, Subhadarshi; Agrawal, Jyoti

2012-03-01

ScienceTomorrow is developing a high-speed, low-cost process for synthesizing high-porosity electrodes for electrochemical double-layer capacitors. Four types of coal (lignite, subbituminous, bituminous, and anthracite) were used as precursor materials for spark discharge activation with multiscale porous structure. The final porosity and pore distribution depended, among other factors, on precursor type. The high gas content in low-grade carbon resulted in mechanical disintegration, whereas high capacitance was attained in higher-grade coal. The properties, including capacitance, mechanical robustness, and internal conductivity, were excellent when the cost is taken into consideration.

Long life 80Ah standard IPV NiH2 battery cell

NASA Technical Reports Server (NTRS)

Armantrout, Jon D.; Waller, J. S.

1995-01-01

A standard Nickel-Hydrogen (NiH2) Individual Pressure Vessel (IPV) battery cell is needed to meet future low cost, high performance mission requirements for NASA, military, and civil space programs. A common or standard cell design has evolved from the heritage of HST, Milstar, and other Air Force Mantech cell designs with substantial flight experience, while incorporating some of the historical COMSAT cell design features described in a previous NASA publication. Key features include slurry process nickel electrodes having high strength, long life and high yield (lower cost), and dual layer zircar separators for improved KOH retention, uniformality, and longer life. The cell design will have a zirconium oxide wall wick inside the pressure vessel to redistribute electrolyte and extend life. The slurry electrode will be 35 mils thick to take advantage of qualified cell mechanical configurations and proven assembly and activation techniques developed by Eagle Picher Industries (EPI) for the Hubble Space Telescope (HST) RNH-90-3 and 'Generic HST' RNH-90-5 cell designs with back-to-back nickel electrodes produced by the dry sinter process. The 80Ah common cell design can be scaled to meet capacity requirements from 60Ah to 100Ah. Producibility, commonality, and long life performance will be enhanced with the robust cell design described herein.

Evaluation of porous carbon felt as an aerobic biocathode support in terms of hydrogen peroxide

NASA Astrophysics Data System (ADS)

Milner, Edward M.; Scott, Keith; Head, Ian M.; Curtis, Tom; Yu, Eileen Hao

2017-07-01

Aerobic biocathodes provide a low-cost and sustainable substitute for expensive precious metal catalysts at the cathode of Microbial Fuel Cells (MFCs). However, the abiotic formation of peroxide, which is catalyzed by the porous carbon support at certain cathode potentials, may be detrimental to their activity. Two different carbon felt supports, one treated with nitric acid, the other untreated, were characterized electrochemically through a series of chronoamperometry (CA) experiments using a novel 4-electrode electrochemical setup, in order to determine the potential at which peroxide is initially formed. Peroxide was detected at a potential of -0.2 V (all potentials are against Ag/AgCl) for the untreated carbon felt electrode and at a potential of -0.05 V for the nitric acid treated carbon felt. Given these results, two half-cells poised at -0.2 and -0.1 V were setup in order to study biocathode formation. The half-cell poised at -0.2 V did not develop an aerobic biocathode, whereas the half-cell poised at -0.1 V developed an aerobic biocathode. This study shows that to develop aerobic biocathodes on carbon felt, cathode electrode potentials more positive than -0.2 V must be applied.

Graphene Oxide/ Ruthenium Oxide Composites for Supercapacitors Electrodes

NASA Astrophysics Data System (ADS)

Amir, Fatima

Supercapacitors are electrical energy storage devices with high power density, high rate capability, low maintenance cost, and long life cycle. They complement or replace batteries in harvesting applications when high power delivery is needed. An important improvement in performance of supercapacitors has been achieved through recent advances in the development of new nanostructured materials. Here we will discuss the fabrication of graphene oxide/ ruthenium oxide supercacitors electrodes including electrophoretic deposition. The morphology and structure of the fabricated electrodes were investigated and will be discussed. The electrochemical properties were determined using cyclic voltammetry and galvanostatic charge/discharge techniques and the experiments that demonstrate the excellent capacitive properties of the obtained supercapacitors will also be discussed. The fabrication and characterization of the samples were performed at the Center of Functional Nanomaterials at Brookhaven National Lab. The developed approaches in our study represent an exciting direction for designing the next generation of energy storage devices. This work was supported in part by the U.S. Department of Energy through the Visiting Faculty Program and the research used resources of the Center for Functional Nanomaterials at Brookhaven National Laboratory.

Bio-inspired patterned networks (BIPS) for development of wearable/disposable biosensors

NASA Astrophysics Data System (ADS)

McLamore, E. S.; Convertino, M.; Hondred, John; Das, Suprem; Claussen, J. C.; Vanegas, D. C.; Gomes, C.

2016-05-01

Here we demonstrate a novel approach for fabricating point of care (POC) wearable electrochemical biosensors based on 3D patterning of bionanocomposite networks. To create Bio-Inspired Patterned network (BIPS) electrodes, we first generate fractal network in silico models that optimize transport of network fluxes according to an energy function. Network patterns are then inkjet printed onto flexible substrate using conductive graphene ink. We then deposit fractal nanometal structures onto the graphene to create a 3D nanocomposite network. Finally, we biofunctionalize the surface with biorecognition agents using covalent bonding. In this paper, BIPS are used to develop high efficiency, low cost biosensors for measuring glucose as a proof of concept. Our results on the fundamental performance of BIPS sensors show that the biomimetic nanostructures significantly enhance biosensor sensitivity, accuracy, response time, limit of detection, and hysteresis compared to conventional POC non fractal electrodes (serpentine, interdigitated, and screen printed electrodes). BIPs, in particular Apollonian patterned BIPS, represent a new generation of POC biosensors based on nanoscale and microscale fractal networks that significantly improve electrical connectivity, leading to enhanced sensor performance.

Integration of gold-sputtered electrofluidic paper on wire-included analytical platforms for glucose biosensing.

PubMed

Núnez-Bajo, Estefanía; Carmen Blanco-López, M; Costa-García, Agustín; Teresa Fernández-Abedul, M

2017-05-15

This work describes the fabrication and evaluation of an electroanalytical paper-based platform based on the combination of both, reusable and disposable materials in order to generate simple, versatile and low-cost microfluidic devices. With this aim, a holder containing metal wires that act as reusable reference and counter electrodes has been developed. The gold-sputtered paper electrode is disposable and easily interchangeable, meanwhile the platform that includes reference and counter electrodes can be reused. The detection zone in the paper is delimited by drawing a hydrophobic line with an inexpensive permanent marker. The effect of experimental variables such as adding solutions through the face where the gold was sputtered (upwards) or through the opposite one (downwards) as well as of other working parameters were studied by cyclic and differential pulse voltammetry with potassium ferrocyanide as a common redox probe and indicator species for enzymatic, immune and DNA biosensing. Enzymatic determination of glucose in real food samples prove the feasibility of the developed system for the construction of electrochemical biosensors. Copyright © 2017 Elsevier B.V. All rights reserved.

Metal-air battery research and development

NASA Astrophysics Data System (ADS)

Behrin, E.; Cooper, J. F.

1982-05-01

This report summarizes the activities of the Metal-air Battery Program during the calendar year 1981. The principal objective is to develop a refuelable battery as an automotive energy source for general-purpose electric vehicles and to conduct engineering demonstrations of its ability to provide vehicles with the range, acceleration, and rapid refueling capability of current internal-combustion-engine automobiles. The second objective is to develop an electrically-rechargeable battery for specific-mission electric vehicles, such as commuter vehicles, that can provide low-cost transportation. The development progression is to: (1) develop a mechanically rechargeable aluminum-air power cell using model electrodes, (2) develop cost-effective anode and cathode materials and structures as required to achieve reliability and efficiency goals, and to establish the economic competitiveness of this technology, and (3) develop and integrated propulsion system utilizing the power cell.

Durability and performance optimization of cathode materials for fuel cells

NASA Astrophysics Data System (ADS)

Colon-Mercado, Hector Rafael

The primary objective of this dissertation is to develop an accelerated durability test (ADT) for the evaluation of cathode materials for fuel cells. The work has been divided in two main categories, namely high temperature fuel cells with emphasis on the Molten Carbonate Fuel Cell (MCFC) cathode current collector corrosion problems and low temperature fuel cells in particular Polymer Electrolyte Fuel Cell (PEMFC) cathode catalyst corrosion. The high operating temperature of MCFC has given it benefits over other fuel cells. These include higher efficiencies (>50%), faster electrode kinetics, etc. At 650°C, the theoretical open circuit voltage is established, providing low electrode overpotentials without requiring any noble metal catalysts and permitting high electrochemical efficiency. The waste heat is generated at sufficiently high temperatures to make it useful as a co-product. However, in order to commercialize the MCFC, a lifetime of 40,000 hours of operation must be achieved. The major limiting factor in the MCFC is the corrosion of cathode materials, which include cathode electrode and cathode current collector. In the first part of this dissertation the corrosion characteristics of bare, heat-treated and cobalt coated titanium alloys were studied using an ADT and compared with that of state of the art current collector material, SS 316. PEMFCs are the best choice for a wide range of portable, stationary and automotive applications because of their high power density and relatively low-temperature operation. However, a major impediment in the commercialization of the fuel cell technology is the cost involved due to the large amount of platinum electrocatalyst used in the cathode catalyst. In an effort to increase the power and decrease the cathode cost in polymer electrolyte fuel cell (PEMFC) systems, Pt-alloy catalysts were developed to increase its activity and stability. Extensive research has been conducted in the area of new alloy development and understanding the mechanisms of ORR. However, a relatively small number of publications are related to the durability of Pt alloys in the PEMFC environment. In the second part of this dissertation an ADT is developed for the evaluation of PEMFC cathode catalysts in a time and cost effective way.

Disposable sensor based on enzyme-free Ni nanowire array electrode to detect glutamate.

PubMed

Jamal, Mamun; Hasan, Maksudul; Mathewson, Alan; Razeeb, Kafil M

2013-02-15

Enzyme free electrochemical sensor platform based on a vertically aligned nickel nanowire array (NiNAE) and Pt coated nickel nanowire array (Pt/NiNAE) have been developed to detect glutamate. Morphological characterisation of Ni electrodes was carried out using scanning and transmission electron microscopy combined with energy dispersive X-ray (SEM-EDX), X-ray diffraction (XRD) and transmission electron microscopy (TEM). Cyclic voltammetry (CV) and amperometry were used to evaluate the catalytic activity of the NiNAE and the Pt/NiNAE for glutamate. It has been found that both NiNAE and Pt/NiNAE electrodes showed remarkably enhanced electrocatalytic activity towards glutamate compared to planar Ni electrodes, and showed higher catalytic activity when compared to other metallic nanostructure electrodes such as gold nanowire array electrodes (AuNAE) and Pt coated gold nanowire array electrode (Pt/AuNAE). The sensitivity of NiNAE and Pt/NiNAE has been found to be 65 and 96 μA mM(-1) cm(-2), respectively, which is approximately 6 to 9 times higher than the state of the art glutamate sensor. Under optimal detection conditions, the as prepared sensors exhibited linear behaviour for glutamate detection in the concentration up to 8mM for both NiNAE and Pt/NiNAE with a limit of detection of 68 and 83 μM, respectively. Experimental results show that the vertically aligned ordered nickel nanowire array electrode (NiNAE) has significant promise for fabricating cost effective, enzyme-less, sensitive, stable and selective sensor platform. Copyright © 2012 Elsevier B.V. All rights reserved.

Vertically cross-linked and porous CoNi2S4 nanosheets-decorated SiC nanowires with exceptional capacitive performance as a free-standing electrode for asymmetric supercapacitors

NASA Astrophysics Data System (ADS)

Zhao, Jian; Li, Zhenjiang; Zhang, Meng; Meng, Alan; Li, Qingdang

2016-11-01

In this paper, a simple, low-cost and mild hydrothermal technology of growing vertically cross-linked ternary nickel cobalt sulfides nanosheets (CoNi2S4 NSs) with porous characteristics on SiC nanowires (SiC NWs) supporters with outstanding resistances to oxidation and corrosion, good conductivity and large specific surface area deposited directly on carbon cloth (CC) is successfully developed, forming a new family of free-standing advanced hybrid electrode for asymmetric supercapacitors (ASCs). Such integrated electrode (SiC NWs@CoNi2S4 NSs) manifests intriguing electrochemical characteristics such as high specific capacity (231.1 mA h g-1 at 2 A g-1) and rate capability due to the synergistic effect of SiC NWs and CoNi2S4 NSs with unique morphology. Additionally, an asymmetric supercapacitor is also assembled via using this special hybrid architectures as positive electrode and activated carbon (AC) on Ni foam (NF) as negative electrode, and it can yield a high energy density of 57.8 W h kg-1 with a power density of 1.6 kW kg-1 and long cycling lifespan. This study constitutes an emerging attractive strategy to reasonably design and fabricate novel SiC NWs-based nanostructured electrodes with enhanced capacity, which holds great potential to be the candidate of electrode materials for environmentally benign as well as high-performance energy storage devices.

Electrode Induced Removal and Recovery of Uranium (VI) from Acidic Subsurfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gregory, Kelvin

2013-08-12

The overarching objective of this research is to provide an improved understanding of how aqueous geochemical conditions impact the removal of U and Tc from groundwater and how engineering design may be utilized to optimize removal of these radionuclides. Experiments were designed to address the unique conditions in Area 3 of ORNL while also providing broader insight into the geochemical effectors of the removal rates and extent for U and Tc. The specific tasks of this work were to: 1) quantify the impact of common aqueous geochemical and operational conditions on the rate and extent of U removal and recoverymore » from water, 2) investigate the removal of Tc with polarized graphite electrode, and determine the influence of geochemical and operational conditions on Tc removal and recovery, 3) determine whether U and Tc may be treated simultaneous from Area 3 groundwater, and examine the bench-scale performance of electrode-based treatment, and 4) determine the capacity of graphite electrodes for U(VI) removal and develop a mathematical, kinetic model for the removal of U(VI) from aqueous solution. Overall the body of work suggests that an electrode-based approach for the remediation of acidic subsurface environments, such as those observed in Area 3 of ORNL may be successful for the removal for both U(VI) and Tc. Carbonaceous (graphite) electrode materials are likely to be the least costly means to maximize removal rates and efficiency by maximizing the electrode surface area.« less

Optimization of electrode characteristics for the Br₂/H₂ redox flow cell

DOE PAGES

Tucker, Michael C.; Cho, Kyu Taek; Weber, Adam Z.; ...

2014-10-17

The Br₂/H₂ redox flow cell shows promise as a high-power, low-cost energy storage device. The effect of various aspects of material selection, processing, and assembly of electrodes on the operation, performance, and efficiency of the system is determined. In particular, (+) electrode thickness, cell compression, hydrogen pressure, and (–) electrode architecture are investigated. Increasing hydrogen pressure and depositing the (–) catalyst layer on the membrane instead of on the carbon-paper backing layers have a large positive impact on performance, enabling a limiting current density above 2 A cm -2 and a peak power density of 1.4 W cm -2. Maximummore » energy efficiency of 79% is achieved. In addition, the root cause of limiting-current behavior in this system is elucidated, where it is found that Br - reversibly adsorbs at the Pt (–) electrode for potentials exceeding a critical value, and the extent of Br - coverage is potential-dependent. This phenomenon limits maximum cell current density and must be addressed in system modeling and design. These findings are expected to lower system cost and enable higher efficiency.« less

Contamination Study of Micro Pulsed Plasma Thruster

DTIC Science & Technology

2008-03-01

missions ranging from nano -satellites to large spacecrafts requiring precision placement1. As an unfortunate side effect, the exhaust plume induces...the electrodes9. The electrodes have often been arranged coaxially . The system consists of electrodes, capacitors as energy storage units, a spark...increasing interest in the so-called micro- and nano -satellites, which are highly maneuverable and have lower cost. These small satellites are aimed to

Integrating 3D Flower-Like Hierarchical Cu2NiSnS4 with Reduced Graphene Oxide as Advanced Anode Materials for Na-Ion Batteries.

PubMed

Yuan, Shuang; Wang, Sai; Li, Lin; Zhu, Yun-hai; Zhang, Xin-bo; Yan, Jun-min

2016-04-13

Development of an anode material with high performance and low cost is crucial for implementation of next-generation Na-ion batteries (NIBs) electrode, which is proposed to meet the challenges of large scale renewable energy storage. Metal chalcogenides are considered as promising anode materials for NIBs due to their high theoretical capacity, low cost, and abundant sources. Unfortunately, their practical application in NIBs is still hindered because of low conductivity and morphological collapse caused by their volume expansion and shrinkage during Na(+) intercalation/deintercalation. To solve the daunting challenges, herein, we fabricated novel three-dimensional (3D) Cu2NiSnS4 nanoflowers (CNTSNs) as a proof-of-concept experiment using a facile and low-cost method. Furthermore, homogeneous integration with reduced graphene oxide nanosheets (RGNs) endows intrinsically insulated CNTSNs with superior electrochemical performances, including high specific capacity (up to 837 mAh g(-1)), good rate capability, and long cycling stability, which could be attributed to the unique 3D hierarchical structure providing fast ion diffusion pathway and high contact area at the electrode/electrolyte interface.

The research of structure and mechanical properties of superhard electro-spark coatings for hardwearing mining tools

NASA Astrophysics Data System (ADS)

Bajin, P. A.; Chijikov, A. P.; Leybo, D. V.; Chuprunov, K. O.; Yudin, A. G.; Alymov, M. A.; Kuznetsov, D. V.

2016-01-01

The development of low cost and hardwearing mining tools is one of the most important areas in mining industry. It is especially important for technologies of rare and rare earth metals mining due to high hardness of related ores. Coatings for electrodes, produced by extrusion of self-propagating high temperature synthesis (SHS) products from hard-alloyed materials with nanosized structure, for further application in processes of electrospark alloying and deposition were studied in this work. The results of microstructure and properties of deposited layers, interaction of support with SHS produced electrodes, comparison of frictional properties of obtained materials as well as some industrial testing results are presented in this work.

Pt-coated cylindrical micropatterned honeycomb Petri dishes as an efficient TCO-free counter electrode in liquid junction photovoltaic devices

NASA Astrophysics Data System (ADS)

Dao, Van-Duong; Bui, Van-Tien; Choi, Ho-Suk

2018-02-01

The Pt layer deposited on a cylindrical micro cavity patterned Petri dish, which is produced using a one-step solvent-immersion phase separation, is fabricated for the first time as an FTO-free counter electrode (CE) for dye-sensitized solar cells (DSCs). Due to the high specific active surface area of the Pt-deposited honeycomb substrate CE, the efficiency of the DSC using the developed CE substrate is enhanced by 14.5% compared with the device using a Pt-sputtered flat substrate. This design strategy has potential in fabricating highly efficient and low-cost CE materials with FTO-free substrates for DSCs.

Materials Science of Electrodes and Interfaces for High-Performance Organic Photovoltaics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marks, Tobin

The science of organic photovoltaic (OPV) cells has made dramatic advances over the past three years with power conversion efficiencies (PCEs) now reaching ~12%. The upper PCE limit of light-to-electrical power conversion for single-junction OPVs as predicted by theory is ~23%. With further basic research, the vision of such devices, composed of non-toxic, earth-abundant, readily easily processed materials replacing/supplementing current-generation inorganic solar cells may become a reality. Organic cells offer potentially low-cost, roll-to-roll manufacturable, and durable solar power for diverse in-door and out-door applications. Importantly, further gains in efficiency and durability, to that competitive with inorganic PVs, will require fundamental,more » understanding-based advances in transparent electrode and interfacial materials science and engineering. This team-science research effort brought together an experienced and highly collaborative interdisciplinary group with expertise in hard and soft matter materials chemistry, materials electronic structure theory, solar cell fabrication and characterization, microstructure characterization, and low temperature materials processing. We addressed in unconventional ways critical electrode-interfacial issues underlying OPV performance -- controlling band offsets between transparent electrodes and organic active-materials, addressing current loss/leakage phenomena at interfaces, and new techniques in cost-effective low temperature and large area cell fabrication. The research foci were: 1) Theory-guided design and synthesis of advanced crystalline and amorphous transparent conducting oxide (TCO) layers which test our basic understanding of TCO structure-transport property relationships, and have high conductivity, transparency, and tunable work functions but without (or minimizing) the dependence on indium. 2) Development of theory-based understanding of optimum configurations for the interfaces between oxide electrodes/interfacial layers and OPV active layer organic molecules/polymers. 3) Exploration and perfection of new processing strategies and cell architectures for the next-generation, large-area flexible OPVs. The goal has been to develop for the solar energy community the fundamental scientific understanding needed to design, fabricate, prototype, and ultimately test high-efficiency cells incorporating these new concepts. We achieved success in all of these directions.« less

Development and characterization of a rechargeable carbon foam electrode containing nickel oxyhydroxide active mass

NASA Astrophysics Data System (ADS)

Chye, Matthew B.

2011-12-01

Batteries and asymmetric electrochemical capacitors using nickel-based positive electrodes can provide high currents due to their defect structure and low internal resistance. Nickel-based positive electrodes, therefore, are ideal for high current applications such as power tools and electric vehicles (EVs). The positive electrodes prepared in this research are monolithic graphitic foams electrochemically impregnated with nickel oxyhydroxide active mass and select additives that enhance electrode performance. Carbon foam is a good current collector due to its light-weight, porous, and graphitic nature, which give its good electrical properties and the ability to be used as a current collector. Replacing sintered nickel current collectors in nickel-based batteries with a low cost, readily available material, carbon foam, can reduce the mass of a rechargeable battery. The goal of this research has been to contribute to fundamental science through better understanding of optimizing the deposition and formation processes of the active mass onto carbon foams as well as investigating the active mass behavior under deposition, formation, and cycling conditions. Flooded cells and a PFA sealed asymmetric capacitor have been used. The effects of carbon foam surface pretreatments and how they affect the active material/carbon foam performance are demonstrated. Also the feasibility of this positive electrode as a component in nickel-based batteries, a Ni-Zn cells and an asymmetric capacitor pouch cell, is demonstrated.

Carbon nanostructures modified LiFePO4 cathodes for lithium ion battery applications: optimized porosity and composition

NASA Astrophysics Data System (ADS)

Mahmoud, Lama; Singh Lalia, Boor; Hashaikeh, Raed

2016-12-01

Lithium iron phosphate (LiFePO4) battery cathode was fabricated without using any metallic current collector and polymeric binder. Carbon nanostructures (CNS) were used as microbinders for LiFePO4 particles and at the same time as a 3D current collector. A facile and cost effective method of fabricating composite cathodes of CNS and LiFePO4 was developed. Thick electrodes with high loading of active material (20-25 mg cm-2) were obtained that are almost 2-3 folds higher than commercial electrodes. SEM images confirm that the 3D CNS conductive network encapsulated the LiFePO4 particles homogenously facilitating the charge transfer at the electrode-CNS interface. The composition, scan rate and porosity of the paper-like cathode were sequentially varied and their influence was systematically monitored by means of linear sweep cyclic voltammetry and AC electrochemical impedance spectroscopy. Addition of CNS improved the electrode’s bulk electronic conductivity, mechanical integrity, surface area and double layer capacitance, yet compromised the charge transfer resistance at the electrode-electrolyte interface. Based on a range of the tested binder-free electrodes, this study proposes that electrodes with 20 wt% CNS having 49 ± 2.5% porosity had realized best improvements of two folds and four folds in the electronic conductivity and diffusion coefficient, respectively.

Comparison between cylindrical and prismatic lithium-ion cell costs using a process based cost model

NASA Astrophysics Data System (ADS)

Ciez, Rebecca E.; Whitacre, J. F.

2017-02-01

The relative size and age of the US electric vehicle market means that a few vehicles are able to drive market-wide trends in the battery chemistries and cell formats on the road today. Three lithium-ion chemistries account for nearly all of the storage capacity, and half of the cells are cylindrical. However, no specific model exists to examine the costs of manufacturing these cylindrical cells. Here we present a process-based cost model tailored to the cylindrical lithium-ion cells currently used in the EV market. We examine the costs for varied cell dimensions, electrode thicknesses, chemistries, and production volumes. Although cost savings are possible from increasing cell dimensions and electrode thicknesses, economies of scale have already been reached, and future cost reductions from increased production volumes are minimal. Prismatic cells, which are able to further capitalize on the cost reduction from larger formats, can offer further reductions than those possible for cylindrical cells.

Development of a reactor with carbon catalysts for modular-scale, low-cost electrochemical generation of H 2O 2

DOE PAGES

Chen, Zhihua; Chen, Shucheng; Siahrostami, Samira; ...

2017-03-01

The development of small-scale, decentralized reactors for H 2O 2 production that can couple to renewable energy sources would be of great benefit, particularly for water purification in the developing world. Herein, we describe our efforts to develop electrochemical reactors for H 2O 2 generation with high Faradaic efficiencies of >90%, requiring cell voltages of only ~1.6 V. The reactor employs a carbon-based catalyst that demonstrates excellent performance for H 2O 2 production under alkaline conditions, as demonstrated by fundamental studies involving rotating-ring disk electrode methods. Finally, the low-cost, membrane-free reactor design represents a step towards a continuous, modular-scale, de-centralizedmore » production of H 2O 2.« less

Thin film battery/fuel cell power generating system. Final report of the continuation contract (Tasks 1-4), April 1, 1978-March 31, 1980

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1980-06-30

Research on the design, development, and testing of a high-temperature solid electrolyte (HTSOE) fuel cell is described in detail. Task 1 involves the development and refinement of fabrication processes for the porous support tube, fuel electrode, solid electrolyte, air electrode, and interconnection. Task 2 includes the life testing of cell components and the stack; task 3 involves the stack performance evaluation; task 4 includes demonstrating the reproducibility of 10 watt stacks. A cost, design and benefit study to evaluate the nature and worth of an industrial cogeneration application of the HTSOE fuel cell is underway. Here, promisng applications are nowmore » being considered, from which a single application has been selected as a basis for the study - an integrated aluminum production facility. (WHK)« less

Phosphoric Acid Fuel Cell Technology Status

NASA Technical Reports Server (NTRS)

Simons, S. N.; King, R. B.; Prokopius, P. R.

1981-01-01

A review of the current phosphoric acid fuel cell system technology development efforts is presented both for multimegawatt systems for electric utility applications and for multikilowatt systems for on-site integrated energy system applications. Improving fuel cell performance, reducing cost, and increasing durability are the technology drivers at this time. Electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, and fuel selection are discussed.

Development of an all-metal thick-film cost-effective metallization system for solar cells

NASA Technical Reports Server (NTRS)

Ross, B.

1981-01-01

Screened electrodes made from fluorocarbon activated copper paste and silver fluoride activated copper paste, tape adhesion and scratch tests were studied. Experiments were conducted with variations in past parameters, firing conditions, including gas ambients, furnace furniture, silicon surface and others. A liquid medium intended to provide transport during the carbon fluoride decomposition, is incorporated in the paste.

Experimental and Theoretical Studies of Nanostructured Electrodes for Use in Dye-Sensitized Solar Cells

NASA Astrophysics Data System (ADS)

Gong, Jiawei

Among various photovoltaic technologies available in the emerging market, dye-sensitized solar cells (DSSCs) are deemed as an effective, competitive solution to the increasing demand for high-efficiency PV devices. To move towards full commercialization, challenges remain in further improvement of device stability as well as reduction of material and manufacturing costs. This study aims at rational synthesis and photovoltaic characterization of two nanostructured electrode materials (i.e. SnO2 nanofibers and activated graphene nanoplatelets) for use as photoanode and counter electrode in dye-sensitized solar cells. The main objective is to explore the favorable charge transport features of SnO2 nanofiber network and simultaneously replace the high-priced conventional electrocatalytic nanomaterials (e.g. Pt nanoparticles) used in existing counter electrode of DSSCs. To achieve this objective, a multiphysics model of electrode kinetics was developed to optimize various design parameters and cell configurations. The porous hollow SnO2 nanofibers were successfully synthesized via a facile route consisting of electrospinning precursor polymer nanofibers, followed by controlled carbonization. The novel SnO2/TiO2 composite photoanode materials carry advantages of SnO2 nanofiber network (e.g. nanostructural continuity, high electron mobility) and TiO2 nanoparticles (e.g. high specific area), and therefore show excellent photovoltaic properties including improved short-circuit current and fill factors. In addition, hydrothermally activated graphene nanoplatelets (aGNP) were used as a catalytic counter electrode material to substitute for conventionally used platinum nanoparticles. Improved catalytic performance of aGNP electrode was achieved through increased surface area and better control of morphology. Dye-sensitized solar cells using these aGNP electrodes had power conversion efficiencies comparable to those using platinum nanoparticles with I-/I3- redox mediators. Moreover, a multiphysics model at the device level was developed to predict the power output characteristics of DSSC using different electrode materials. The developed model was validated by the experimental data acquired from lab-fabricated DSSCs. Further, parametric simulation was conducted to analyze the effect of series resistance, shunt resistance, interfacial overpotential, as well as difference between the conduction band and formal redox potentials on device performance. This model correlates the maximum power output of DSSC devices to various design and operating parameters, and it also provides insight into the working principles of newly designed devices.

Preparation and evaluation of advanced electrocatalysts for phosphoric acid fuel cells

NASA Technical Reports Server (NTRS)

Stonehart, P.; Baris, J.; Hochmuth, J.; Pagliaro, P.

1981-01-01

Two cooperative phenomena are required the development of highly efficient porous electrocatalysts: (1) is an increase in the electrocatalytic activity of the catalyst particle; and (2) is the availability of that electrocatalyst particle for the electromechanical reaction. The two processes interact with each other so that improvements in the electrochemical activity must be coupled with improvements in the availability of the electrocatalyst for reaction. Cost effective and highly reactive electrocatalysts were developed. The utilization of the electrocatalyst particles in the porous electrode structures was analyzed. It is shown that a large percentage of the electrocatalyst in anode structures is not utilized. This low utilization translates directly into a noble metal cost penalty for the fuel cell.

Electrohydraulic Forming of Near-Net Shape Automotive Panels

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golovaschenko, Sergey F.

2013-09-26

The objective of this project was to develop the electrohydraulic forming (EHF) process as a near-net shape automotive panel manufacturing technology that simultaneously reduces the energy embedded in vehicles and the energy consumed while producing automotive structures. Pulsed pressure is created via a shockwave generated by the discharge of high voltage capacitors through a pair of electrodes in a liquid-filled chamber. The shockwave in the liquid initiated by the expansion of the plasma channel formed between two electrodes propagates towards the blank and causes the blank to be deformed into a one-sided die cavity. The numerical model of the EHFmore » process was validated experimentally and was successfully applied to the design of the electrode system and to a multi-electrode EHF chamber for full scale validation of the process. The numerical model was able to predict stresses in the dies during pulsed forming and was validated by the experimental study of the die insert failure mode for corner filling operations. The electrohydraulic forming process and its major subsystems, including durable electrodes, an EHF chamber, a water/air management system, a pulse generator and integrated process controls, were validated to be capable to operate in a fully automated, computer controlled mode for forming of a portion of a full-scale sheet metal component in laboratory conditions. Additionally, the novel processes of electrohydraulic trimming and electrohydraulic calibration were demonstrated at a reduced-scale component level. Furthermore, a hybrid process combining conventional stamping with EHF was demonstrated as a laboratory process for a full-scale automotive panel formed out of AHSS material. The economic feasibility of the developed EHF processes was defined by developing a cost model of the EHF process in comparison to the conventional stamping process.« less

Demonstration of Next-Generation PEM CHP Systems for Global Markets Using PBI Membrane Technology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vogel, John; Fritz Intwala, Katrina

Plug Power and BASF have conducted eight years of development work prior to this project, demonstrating the potential of PBI membranes to exceed many DOE technical targets. This project consisted of; 1.The development of a worldwide system architecture; 2.Stack and balance of plant module development; 3.Development of an improved, lower cost MEA electrode; 4.Receipt of an improved MEA from the EU consortium; 5.Integration of modules into a system; and 6.Delivery of system to EU consortium for additional integration of technologies and testing.

Advanced Drying Process for Lower Manufacturing Cost of Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmad, Iftikhar; Zhang, Pu

For this Vehicle Technologies Incubator/Energy Storage R&D topic, Lambda Technologies teamed with Navitas Systems and proposed a new advanced drying process that promised a 5X reduction in electrode drying time and significant reduction in the cost of large format lithium batteries used in PEV's. The operating principle of the proposed process was to use penetrating radiant energy source Variable Frequency Microwaves (VFM), that are selectively absorbed by the polar water or solvent molecules instantly in the entire volume of the electrode. The solvent molecules are thus driven out of the electrode thickness making the process more efficient and much fastermore » than convective drying method. To evaluate the Advanced Drying Process (ADP) a hybrid prototype system utilizing VFM and hot air flow was designed and fabricated. While VFM drives the solvent out of the electrode thickness, the hot air flow exhausts the solvent vapors out of the chamber. The drying results from this prototype were very encouraging. For water based anodes there is a 5X drying advantage (time & length of oven) in using ADP over standard drying system and for the NMP based cathodes the reduction in drying time has 3X benefit. For energy savings the power consumption measurements were performed to ADP prototype and compared with the convection standard drying oven. The data collected demonstrated over 40% saving in power consumption with ADP as compared to the convection drying systems. The energy savings are one of the operational cost benefits possible with ADP. To further speed up the drying process, the ADP prototype was explored as a booster module before the convection oven and for the electrode material being evaluated it was possible to increase the drying speed by a factor of 4, which could not be accomplished with the standard dryer without surface defects and cracks. The instantaneous penetration of microwave in the entire slurry thickness showed a major advantage in rapid drying of the electrode materials. For the existing electrode materials, the material analysis and cell characterization data from ADP dried electrodes showed equivalent (or slightly better) performance. However, for high loading and thicker electrode materials (for high energy densities) the ADP advantages are more prominent. There was less binder migration, the resistance was lower hence the current capacities and retention of the battery cells were higher. The success of the project has enabled credible communications with commercial end users as well as battery coating line integrators. Goal is to scale ADP up for high volume manufacturing of Li-ion battery electrodes. The implementation of ADP in high volume manufacturing will reduce a high cost production step to bring the overall price of Li-ion batteries down. This will ultimately have a positive impact on the public by making electric and hybrid vehicles more affordable.« less

Self-grown oxy-hydroxide@ nanoporous metal electrode for high-performance supercapacitors.

PubMed

Kang, JianLi; Hirata, Akihiko; Qiu, H-J; Chen, LuYang; Ge, XingBo; Fujita, Takeshi; Chen, MingWei

2014-01-15

A binder-free self-grown oxy-hydroxide@nanoporous Ni-Mn hybrid electrode with high capacitance and cyclic stability is fabricated by electrochemical polarization of a dealloyed nanoporous Ni-Mn alloy. Combined with the low material costs, high electrochemical stability, and environmentally friendly nature, this novel electrode holds great promise for applications in high-capacity commercial supercapacitors. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Aerosol jet printed p- and n-type electrolyte-gated transistors with a variety of electrode materials: exploring practical routes to printed electronics.

PubMed

Hong, Kihyon; Kim, Se Hyun; Mahajan, Ankit; Frisbie, C Daniel

2014-11-12

Printing electrically functional liquid inks is a promising approach for achieving low-cost, large-area, additive manufacturing of flexible electronic circuits. To print thin-film transistors, a basic building block of thin-film electronics, it is important to have several options for printable electrode materials that exhibit high conductivity, high stability, and low-cost. Here we report completely aerosol jet printed (AJP) p- and n-type electrolyte-gated transistors (EGTs) using a variety of different electrode materials including highly conductive metal nanoparticles (Ag), conducting polymers (polystyrenesulfonate doped poly(3,4-ethylendedioxythiophene, PEDOT:PSS), transparent conducting oxides (indium tin oxide), and carbon-based materials (reduced graphene oxide). Using these source-drain electrode materials and a PEDOT:PSS/ion gel gate stack, we demonstrated all-printed p- and n-type EGTs in combination with poly(3-hexythiophene) and ZnO semiconductors. All transistor components (including electrodes, semiconductors, and gate insulators) were printed by AJP. Both kinds of devices showed typical p- and n-type transistor characteristics, and exhibited both low-threshold voltages (<2 V) and high hole and electron mobilities. Our assessment suggests Ag electrodes may be the best option in terms of overall performance for both types of EGTs.

Scalable Dry Printing Manufacturing to Enable Long-Life and High Energy Lithium-Ion Batteries

DOE PAGES

Liu, Jin; Ludwig, Brandon; Liu, Yangtao; ...

2017-08-22

Slurry casting method dominates the electrode manufacture of lithium-ion batteries. The entire procedure is similar to the newspaper printing that includes premixing of cast materials into solvents homogeneously, and continuously transferring and drying the slurry mixture onto the current collector. As a market approaching US $80 billion by 2024, the optimization of manufacture process is crucial and attractive. However, the organic solvent remains irreplaceable in the wet method for making slurries, even though it is capital-intensive and toxic. In this paper, an advanced powder printing technique is demonstrated that is completely solvent-free and dry. Through removing the solvent and relatedmore » procedures, this method is anticipated to statistically save 20% of the cost at a remarkably shortened production cycle (from hours to minutes). The dry printed electrodes outperform commercial slurry cast ones in 650 cycles (80% capacity retention in 500 cycles), and thick electrodes are successfully fabricated to increase the energy density. Furthermore, microscopy techniques are utilized to characterize the difference of electrode microstructure between dry and wet methods, and distinguish dry printing's advantages on controlling the microstructure. Finally, this study proves a practical fabrication method for lithium-ion electrodes with lowered cost and favorable performance, and allows more advanced electrode designs potentially.« less

Scalable Dry Printing Manufacturing to Enable Long-Life and High Energy Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Jin; Ludwig, Brandon; Liu, Yangtao

Slurry casting method dominates the electrode manufacture of lithium-ion batteries. The entire procedure is similar to the newspaper printing that includes premixing of cast materials into solvents homogeneously, and continuously transferring and drying the slurry mixture onto the current collector. As a market approaching US $80 billion by 2024, the optimization of manufacture process is crucial and attractive. However, the organic solvent remains irreplaceable in the wet method for making slurries, even though it is capital-intensive and toxic. In this paper, an advanced powder printing technique is demonstrated that is completely solvent-free and dry. Through removing the solvent and relatedmore » procedures, this method is anticipated to statistically save 20% of the cost at a remarkably shortened production cycle (from hours to minutes). The dry printed electrodes outperform commercial slurry cast ones in 650 cycles (80% capacity retention in 500 cycles), and thick electrodes are successfully fabricated to increase the energy density. Furthermore, microscopy techniques are utilized to characterize the difference of electrode microstructure between dry and wet methods, and distinguish dry printing's advantages on controlling the microstructure. Finally, this study proves a practical fabrication method for lithium-ion electrodes with lowered cost and favorable performance, and allows more advanced electrode designs potentially.« less

Electro-catalytic biodiesel production from canola oil in methanolic and ethanolic solutions with low cost stainless steel and hybrid ion-exchange resin grafted electrodes

NASA Astrophysics Data System (ADS)

Allioux, Francois-Marie; Holland, Brendan J.; Kong, Lingxue; Dumée, Ludovic F.

2017-07-01

Biodiesel is a growing alternative to petroleum fuels and is produced by the catalysed transesterification of fats in presence of an alcohol base. Transesterification processes using homogeneous catalysts are considered to be amongst the most efficient methods but rely on the feedstock quality and low water content in order to avoid undesirable saponification reactions. In this work, the electro-catalytic conversion of canola oil to biodiesel in a 1% aqueous methanolic and ethanolic reaction mixture was performed without the addition of external catalyst or co-solvent. An inexpensive stainless steel electrode and a hybrid stainless steel electrode coated with an ion-exchange resin catalyst were used as cathode materials while the anode was composed of a plain carbon paper. The cell voltages were varied from 10 to 40 V and the reaction temperature maintained at 20 or 40°C. The canola oil conversion rates were found to be superior at 40°C without saponification reactions for cell voltages below 30 V. The conversion rates were as high as 87% for the hybrid electrode and 81% for the plain stainless steel electrode. This work could inspire new process development for the conversion of high water content feedstock for the production of second-generation biodiesel.

Transparent metal selenide alloy counter electrodes for high-efficiency bifacial dye-sensitized solar cells.

PubMed

Duan, Yanyan; Tang, Qunwei; Liu, Juan; He, Benlin; Yu, Liangmin

2014-12-22

The exploration of cost-effective and transparent counter electrodes (CEs) is a persistent objective in the development of bifacial dye-sensitized solar cells (DSSCs). Transparent counter electrodes based on binary-alloy metal selenides (M-Se; M=Co, Ni, Cu, Fe, Ru) are now obtained by a mild, solution-based method and employed in efficient bifacial DSSCs. Owing to superior charge-transfer ability for the I(-) /I3 (-) redox couple, electrocatalytic activity toward I3 (-) reduction, and optical transparency, the bifacial DSSCs with CEs consisting of a metal selenide alloy yield front and rear efficiencies of 8.30 % and 4.63 % for Co0.85 Se, 7.85 % and 4.37 % for Ni0.85 Se, 6.43 % and 4.24 % for Cu0.50 Se, 7.64 % and 5.05 % for FeSe, and 9.22 % and 5.90 % for Ru0.33 Se in comparison with 6.18 % and 3.56 % for a cell with an electrode based on pristine platinum, respectively. Moreover, fast activity onset, high multiple start/stop capability, and relatively good stability demonstrate that these new electrodes should find applications in solar panels. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Transparent bifacial dye-sensitized solar cells based on organic counter electrodes and iodine-free electrolyte

NASA Astrophysics Data System (ADS)

Ku, Zhiliang; Rong, Yaoguang; Han, Hongwei

2013-10-01

In this study, a novel bifacially active transparent dye-sensitized solar cell (DSSCs) assembled with a transparent poly(3,4-ethylenedioxythiophene) (PEDOT) counter electrode and a colorless iodine-free polymer gel (IFPG) electrolyte was developed. The IFPG electrolyte was prepared by employing an ionic liquid (1,2-dimethyl-3-propylinmidazolium iodide, DMPII) as the charge transfer intermediate and a polymer composite as the gelator without the addition of iodine, exhibiting high conductivity and non-absorption characters. PEDOT electrodes were prepared via a facile electro-polymerization method. By controlling the amount of polymerization charge capacity, we optimized the PEDOT electrodes with high transparency and a favorable activity for catalyzing the IFPG electrolyte. The bifacial DSSCs device fabricated by this kind of transparent PEDOT electrode and colorless IFPG electrolyte showed a power conversion efficiency (PCE) of 6.35% and 4.98% at 100 mW cm-2 AM1.5 illumination corresponding to front- and rear-side illumination. It is notable that the PCE under rear-side illumination approaches 80% that of front-side illumination. Moreover, the device shows excellent stability as confirmed by aging test. These promising results highlight the enormous potential of this transparent PEDOT CE and colorless IFPG electrolyte in scaling up and commercialization of low cost and effective bifacial DSSCs.

Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology

PubMed Central

Ye-Lin, Yiyao; Garcia-Casado, Javier

2018-01-01

Among many of the electrode designs used in electrocardiography (ECG), concentric ring electrodes (CREs) are one of the most promising due to their enhanced spatial resolution. Their development has undergone a great push due to their use in recent years; however, they are not yet widely used in clinical practice. CRE implementation in textiles will lead to a low cost, flexible, comfortable, and robust electrode capable of detecting high spatial resolution ECG signals. A textile CRE set has been designed and developed using screen-printing technology. This is a mature technology in the textile industry and, therefore, does not require heavy investments. Inks employed as conductive elements have been silver and a conducting polymer (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS). Conducting polymers have biocompatibility advantages, they can be used with flexible substrates, and they are available for several printing technologies. CREs implemented with both inks have been compared by analyzing their electric features and their performance in detecting ECG signals. The results reveal that silver CREs present a higher average thickness and slightly lower skin-electrode impedance than PEDOT:PSS CREs. As for ECG recordings with subjects at rest, both CREs allowed the uptake of bipolar concentric ECG signals (BC-ECG) with signal-to-noise ratios similar to that of conventional ECG recordings. Regarding the saturation and alterations of ECGs captured with textile CREs caused by intentional subject movements, silver CREs presented a more stable response (fewer saturations and alterations) than those of PEDOT:PSS. Moreover, BC-ECG signals provided higher spatial resolution compared to conventional ECG. This improved spatial resolution was manifested in the identification of P1 and P2 waves of atrial activity in most of the BC-ECG signals. It can be concluded that textile silver CREs are more suitable than those of PEDOT:PSS for obtaining BC-ECG records. These developed textile electrodes bring the use of CREs closer to the clinical environment. PMID:29361722

Textile Concentric Ring Electrodes for ECG Recording Based on Screen-Printing Technology.

PubMed

Lidón-Roger, José Vicente; Prats-Boluda, Gema; Ye-Lin, Yiyao; Garcia-Casado, Javier; Garcia-Breijo, Eduardo

2018-01-21

Among many of the electrode designs used in electrocardiography (ECG), concentric ring electrodes (CREs) are one of the most promising due to their enhanced spatial resolution. Their development has undergone a great push due to their use in recent years; however, they are not yet widely used in clinical practice. CRE implementation in textiles will lead to a low cost, flexible, comfortable, and robust electrode capable of detecting high spatial resolution ECG signals. A textile CRE set has been designed and developed using screen-printing technology. This is a mature technology in the textile industry and, therefore, does not require heavy investments. Inks employed as conductive elements have been silver and a conducting polymer (poly (3,4-ethylenedioxythiophene) polystyrene sulfonate; PEDOT:PSS). Conducting polymers have biocompatibility advantages, they can be used with flexible substrates, and they are available for several printing technologies. CREs implemented with both inks have been compared by analyzing their electric features and their performance in detecting ECG signals. The results reveal that silver CREs present a higher average thickness and slightly lower skin-electrode impedance than PEDOT:PSS CREs. As for ECG recordings with subjects at rest, both CREs allowed the uptake of bipolar concentric ECG signals (BC-ECG) with signal-to-noise ratios similar to that of conventional ECG recordings. Regarding the saturation and alterations of ECGs captured with textile CREs caused by intentional subject movements, silver CREs presented a more stable response (fewer saturations and alterations) than those of PEDOT:PSS. Moreover, BC-ECG signals provided higher spatial resolution compared to conventional ECG. This improved spatial resolution was manifested in the identification of P1 and P2 waves of atrial activity in most of the BC-ECG signals. It can be concluded that textile silver CREs are more suitable than those of PEDOT:PSS for obtaining BC-ECG records. These developed textile electrodes bring the use of CREs closer to the clinical environment.

Manufacturing of Low Cost, Durable Membrane Electrode Assemblies Engineered for Rapid Conditioning

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busby, Colin

Over the past 20 years significant progress in membrane-electrode assembly (MEA) technology development for polymer electrolyte fuel cells (PEMFCs) has resulted in the PEMFC technology approaching a commercial reality for transportation applications. However, there remain two primary technical challenges to be addressed in the MEA. First and foremost is meeting the automotive cost targets: Producing a fuel cell stack cost competitive with today’s internal combustion engine. In addition to the material cost, MEA (and other components) and stack assembly production methods must be amenable for use in low cost, high speed, automotive assembly line. One impediment to this latter goalmore » is that stack components must currently go through a long and tedious conditioning procedure before they produce optimal power. This so-called “break-in” can take many hours, and can involve quite complex voltage, temperature and/or pressure steps. These break-in procedures must be simplified and the time required reduced if fuel cells are to become a viable automotive engine. The second challenge is to achieve the durability targets in real-world automotive duty cycle operations. Significant improvements in cost, break-in time, and durability for the key component of fuel cell stacks, MEAs were achieved in this project. Advanced modeling was used to guide design of the new MEA to maximize performance and durability. A new, innovative process and manufacturing approach utilizing direct in-line coating using scalable, cost-competitive, continuous high volume 3-layer rolled-good manufacturing processes was developed and validated by single cell and short stack testing. In addition, the direct coating methods employed were shown to reduce the cost for sacrificial films. Furthermore, Gore has demonstrated a 10 µm reinforced membrane that is used in the new low-cost process and can meet automotive power density and durability targets. Across a wide range of operating conditions, the direct-coated MEA outperformed the commercial baseline MEA, and did so through a process that delivers MEAs at $92.35/m2 at a volume of 500,000 systems per year, according to Strategic Analysis (SA) estimates.« less

A techno-economic analysis and optimization of Li-ion batteries for light-duty passenger vehicle electrification

NASA Astrophysics Data System (ADS)

Sakti, Apurba; Michalek, Jeremy J.; Fuchs, Erica R. H.; Whitacre, Jay F.

2015-01-01

We conduct a techno-economic analysis of Li-ion NMC-G prismatic pouch battery and pack designs for electric vehicle applications. We develop models of power capability and manufacturing operations to identify the minimum cost cell and pack designs for a variety of plug-in hybrid electric vehicle (PHEV) and battery electric vehicle (BEV) requirements. We find that economies of scale in battery manufacturing are reached quickly at a production volume of ∼200-300 MWh annually. Increased volume does little to reduce unit costs, except potentially indirectly through factors such as experience, learning, and innovation. We also find that vehicle applications with larger energy requirements are able to utilize cheaper cells due in part to the use of thicker electrodes. The effect on cost can be substantial. In our base case, we estimate pack-level battery production costs of ∼545 kWh-1 for a PHEV with a 10 mile (16 km) all-electric range (PHEV10) and ∼230 kWh-1 for a BEV with a 200 mile (320 km) all-electric range (BEV200). This 58% reduction, from 545 kWh-1 to 230 kWh-1, is a larger effect than the uncertainty represented by our optimistic and pessimistic scenarios. Electrodes thicker than about 100 or 125 microns are not currently used in practice due to manufacturing and durability concerns, but relaxing this constraint could further lower the cost of larger capacity BEV200 packs by up to an additional 8%.

Utilization of UV Curing Technology to Significantly Reduce the Manufacturing Cost of LIB Electrodes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Voelker, Gary; Arnold, John

2015-11-30

Previously identified novel binders and associated UV curing technology have been shown to reduce the time required to apply and finish electrode coatings from tens of minutes to less than one second. This revolutionary approach can result in dramatic increases in process speeds, significantly reduced capital (a factor of 10 to 20) and operating costs, reduced energy requirements, and reduced environmental concerns and costs due to the virtual elimination of harmful volatile organic solvents and associated solvent dryers and recovery systems. The accumulated advantages of higher speed, lower capital and operating costs, reduced footprint, lack of VOC recovery, and reducedmore » energy cost is a reduction of 90% in the manufacturing cost of cathodes. When commercialized, the resulting cost reduction in Lithium batteries will allow storage device manufacturers to expand their sales in the market and thereby accrue the energy savings of broader utilization of HEVs, PHEVs and EVs in the U.S., and a broad technology export market is also envisioned.« less

Fabrication and characterization of microfabricated on-chip microelectrochemical cell for biosensing applications

NASA Astrophysics Data System (ADS)

Said, N. A. Mohd; Twomey, K.; Herzog, G.; Ogurtsov, V. I.

2017-03-01

The fabrication of on-chip microelectrochemical cell on Si wafer by means of photolithography is described here. The single on-chip microelectrochemical cell device has dimensions of 100 × 380 mm with integrated Pt counter electrode (CE), Ag/AgCl reference electrode (RE) and gold microelectrode array of 500 nm recess depth as the working electrode (WE). Two geometries of electrode array were implemented, band and disc, with fixed diameter/width of 10 µm; and varied centre-to-centre spacing (d) and number of electrodes (N) in the array. The on-chip microelectrochemical cell structure has been designed to facilitate further WE biomodifications. Firstly, the developed microelectrochemical cell does not require packaging hence reducing the production cost and time. Secondly, the working electrode (WE) on the microelectrochemical cell is positioned towards the end of the chip enabling modification of the working electrode surface to be carried out for surface bio-functionalisation without affecting both the RE and CE surface conditions. The developed on-chip microelectrochemical cell was examined with scanning electron microscopy (SEM) and characterised by two electrochemical techniques. Both cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) were performed in 1 mM ferrocenecarboxylic acid (FCA) in 0.01 M phosphate buffered saline (PBS) solution at pH7.4. Electrochemical experiments showed that in the case of halving the interspacing distance of the microdisc WE array (50 nm instead of 100 nm), the voltammogram shifted from a steady-state CV (feature of hemispherical diffusion) to an inclined peak-shaped CV (feature of linear diffusion) albeit the arrays had the same surface area. In terms of EIS it was also found that linear diffusion dominates the surface instead of hemispherical diffusion once the interspacing distance was reduced, supporting the fact that closely packed arrays may behave like a macroelectrode

Augmented reality-based electrode guidance system for reliable electroencephalography.

PubMed

Song, Chanho; Jeon, Sangseo; Lee, Seongpung; Ha, Ho-Gun; Kim, Jonghyun; Hong, Jaesung

2018-05-24

In longitudinal electroencephalography (EEG) studies, repeatable electrode positioning is essential for reliable EEG assessment. Conventional methods use anatomical landmarks as fiducial locations for the electrode placement. Since the landmarks are manually identified, the EEG assessment is inevitably unreliable because of individual variations among the subjects and the examiners. To overcome this unreliability, an augmented reality (AR) visualization-based electrode guidance system was proposed. The proposed electrode guidance system is based on AR visualization to replace the manual electrode positioning. After scanning and registration of the facial surface of a subject by an RGB-D camera, the AR of the initial electrode positions as reference positions is overlapped with the current electrode positions in real time. Thus, it can guide the position of the subsequently placed electrodes with high repeatability. The experimental results with the phantom show that the repeatability of the electrode positioning was improved compared to that of the conventional 10-20 positioning system. The proposed AR guidance system improves the electrode positioning performance with a cost-effective system, which uses only RGB-D camera. This system can be used as an alternative to the international 10-20 system.

Optical Breast Shape Capture and Finite Element Mesh Generation for Electrical Impedance Tomography

PubMed Central

Forsyth, J.; Borsic, A.; Halter, R.J.; Hartov, A.; Paulsen, K.D.

2011-01-01

X-Ray mammography is the standard for breast cancer screening. The development of alternative imaging modalities is desirable because Mammograms expose patients to ionizing radiation. Electrical Impedance Tomography (EIT) may be used to determine tissue conductivity, a property which is an indicator of cancer presence. EIT is also a low-cost imaging solution and does not involve ionizing radiation. In breast EIT, impedance measurements are made using electrodes placed on the surface of the patient’s breast. The complex conductivity of the volume of the breast is estimated by a reconstruction algorithm. EIT reconstruction is a severely ill-posed inverse problem. As a result, noisy instrumentation and incorrect modelling of the electrodes and domain shape produce significant image artefacts. In this paper, we propose a method that has the potential to reduce these errors by accurately modelling the patient breast shape. A 3D hand-held optical scanner is used to acquire the breast geometry and electrode positions. We develop methods for processing the data from the scanner and producing volume meshes accurately matching the breast surface and electrode locations, which can be used for image reconstruction. We demonstrate this method for a plaster breast phantom and a human subject. Using this approach will allow patient-specific finite element meshes to be generated which has the potential to improve the clinical value of EIT for breast cancer diagnosis. PMID:21646711

Cellulose nanofibril/reduced graphene oxide/carbon nanotube hybrid aerogels for highly flexible and all-solid-state supercapacitors.

PubMed

Zheng, Qifeng; Cai, Zhiyong; Ma, Zhenqiang; Gong, Shaoqin

2015-02-11

A novel type of highly flexible and all-solid-state supercapacitor that uses cellulose nanofibril (CNF)/reduced graphene oxide (RGO)/carbon nanotube (CNT) hybrid aerogels as electrodes and H2SO4/poly(vinyl alcohol) (PVA) gel as the electrolyte was developed and is reported here. These flexible solid-state supercapacitors were fabricated without any binders, current collectors, or electroactive additives. Because of the porous structure of the CNF/RGO/CNT aerogel electrodes and the excellent electrolyte absorption properties of the CNFs present in the aerogel electrodes, the resulting flexible supercapacitors exhibited a high specific capacitance (i.e., 252 F g(-1) at a discharge current density of 0.5 A g(-1)) and a remarkable cycle stability (i.e., more than 99.5% of the capacitance was retained after 1000 charge-discharge cycles at a current density of 1 A g(-1)). Furthermore, the supercapacitors also showed extremely high areal capacitance, areal power density, and energy density (i.e., 216 mF cm(-2), 9.5 mW cm(-2), and 28.4 μWh cm(-2), respectively). In light of its excellent electrical performance, low cost, ease of large-scale manufacturing, and environmental friendliness, the CNF/RGO/CNT aerogel electrodes may have a promising application in the development of flexible energy-storage devices.

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels

PubMed Central

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-01-01

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30–70 Ohm/square), optical transmittance values (89–90%), and haze (0.5–1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle. PMID:27677410

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels.

PubMed

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-09-28

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30-70 Ohm/square), optical transmittance values (89-90%), and haze (0.5-1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle.

Roll-to-roll slot-die coating of 400 mm wide, flexible, transparent Ag nanowire films for flexible touch screen panels

NASA Astrophysics Data System (ADS)

Kim, Dong-Ju; Shin, Hae-In; Ko, Eun-Hye; Kim, Ki-Hyun; Kim, Tae-Woong; Kim, Han-Ki

2016-09-01

We report fabrication of large area Ag nanowire (NW) film coated using a continuous roll-to-roll (RTR) slot die coater as a viable alternative to conventional ITO electrodes for cost-effective and large-area flexible touch screen panels (TSPs). By controlling the flow rate of shear-thinning Ag NW ink in the slot die, we fabricated Ag NW percolating network films with different sheet resistances (30-70 Ohm/square), optical transmittance values (89-90%), and haze (0.5-1%) percentages. Outer/inner bending, twisting, and rolling tests as well as dynamic fatigue tests demonstrated that the mechanical flexibility of the slot-die coated Ag NW films was superior to that of conventional ITO films. Using diamond-shape patterned Ag NW layer electrodes (50 Ohm/square, 90% optical transmittance), we fabricated 12-inch flexible film-film type and rigid glass-film-film type TSPs. Successful operation of flexible TSPs with Ag NW electrodes indicates that slot-die-coated large-area Ag NW films are promising low cost, high performance, and flexible transparent electrodes for cost-effective large-area flexible TSPs and can be substituted for ITO films, which have high sheet resistance and are brittle.

Membrane-less hybrid flow battery based on low-cost elements

NASA Astrophysics Data System (ADS)

Leung, P. K.; Martin, T.; Shah, A. A.; Mohamed, M. R.; Anderson, M. A.; Palma, J.

2017-02-01

The capital cost of conventional redox flow batteries is relatively high (>USD 200/kWh) due to the use of expensive active materials and ion-exchange membranes. This paper presents a membrane-less hybrid organic-inorganic flow battery based on the low-cost elements zinc (92.7% with the use of carbon felt electrodes. In the presence of a fully oxidized active species close to its solubility limit, dissolution of the deposited anode is relatively slow (<2.37 g h-1 cm-2) with an equivalent corrosion current density of <1.9 mA cm-2. In a parallel plate flow configuration, the resulting battery was charge-discharge cycled at 30 mA cm-2 with average coulombic and energy efficiencies of c.a. 71.8 and c.a. 42.0% over 20 cycles, respectively.

Impact of uniform electrode current distribution on ETF

NASA Technical Reports Server (NTRS)

Bents, D. J.

1982-01-01

The design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution are examined and the alternate consolidation design which occur are presented compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is given for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

An aqueous electrolyte, sodium ion functional, large format energy storage device for stationary applications

NASA Astrophysics Data System (ADS)

Whitacre, J. F.; Wiley, T.; Shanbhag, S.; Wenzhuo, Y.; Mohamed, A.; Chun, S. E.; Weber, E.; Blackwood, D.; Lynch-Bell, E.; Gulakowski, J.; Smith, C.; Humphreys, D.

2012-09-01

An approach to making large format economical energy storage devices based on a sodium-interactive set of electrodes in a neutral pH aqueous electrolyte is described. The economics of materials and manufacturing are examined, followed by a description of an asymmetric/hybrid device that has λ-MnO2 positive electrode material and low cost activated carbon as the negative electrode material. Data presented include materials characterization of the active materials, cyclic voltammetry, galvanostatic charge/discharge cycling, and application-specific performance of an 80 V, 2.4 kW h pack. The results indicate that this set of electrochemical couples is stable, low cost, requires minimal battery management control electronics, and therefore has potential for use in stationary applications where device energy density is not a concern.

Synthesis and characterization of nanostructured electrodes for solid state ionic devices

NASA Astrophysics Data System (ADS)

Zhang, Yuelan

Solid-state electrochemical energy conversion and storage technologies such as fuel cells and lithium ion batteries will influence the way we use energy and the environment we live in. The demands for advanced power sources with high energy efficiency, minimum environmental impact, and low cost have been the impetus for the development of a new generation of batteries and fuel cells. Currently, lithium ion battery technology's greatest disadvantages are long-term cycling stability and high charge/discharge rate capabilities. On the other hand, fuel cell technology's greatest disadvantage is cost. It is found that these problems could be attenuated by the incorporation of nano-structured materials. But, we are still far away from possessing a solid scientific understanding of what goes on at the nanoscale inside these solid state ionic devices, and what is the relationship between nano-structures and their electrochemical properties, especially between the microstructure and electrode polarization and degradation. Electrode polarization represents a voltage loss in an electrochemical energy conversion process. Such understanding is critical for further progress in solid state ionic devices. This thesis focused on the design, fabrication, and characterization of nanostructured porous electrodes with desired composition and microstructure to minimize electrode polarization losses in the application of fuel cells and lithium ion batteries. Various chemical methods such as sol-gel, hydrothermal, surfactant, colloidal and polymer template-assisted processes have been applied in this work. And various characterization techniques have been used to explore the understanding of the microscopic features with electrochemical interfacial properties of the electrodes. Solid-state diffusion often limits the utilization and rate capability of electrode materials in a lithium-ion battery, especially at high charge/discharge rates. When the fluxes of Li+ insertion or extraction exceeds the diffusion-limited rate of Li+ transport within the bulk phase of an electrode, concentration polarization occurs. Further, large volume changes associated with Li+ insertion or extraction could induce stresses in bulk electrodes, potentially leading to mechanical failure. Porous electrodes with high surface-to-volume ratio would increase the electrochemical reaction surface and suppress the mechanical stress. But porous electrodes also increase the tortuosity of mass transport within solid electrodes. Interconnected porous materials would decrease the percolation threshold for porous electrodes. In this work, electrodes with unique architecture for lithium ion batteries have been fabricated to improve the cycleability, rate capability and capacity retention. Spinel LiMn2O4 with interconnected macropores was created using a glycine-nitrate combustion process. Both microstructure and phase crystallinity were optimized by adjusting the fuel/oxidant ratio. This macroporous LiMn2O4 positive electrode exhibited better capacity retention and rate capability than those with larger particle size prepared by solid state reaction. Detailed electrode kinetic studies indicated that the macroporous microstructure promoted lithium diffusion and the overall reaction process was not controlled by lithium diffusion. Nanostructured tin oxide thin films with columnar grains less than 20 nm were deposited on Au/Si substrate using a combustion CVD method. The microstructure was highly porous and open, and thus was easily accessible to liquid electrolyte. In addition, the microstructure with vertical and radial connectivity of active materials led to decreased tortuosity for mass transport within solid electrodes. Nanoparticles accommodated the large volume change during cycling. These thin film electrodes exhibited highly reversible specific capacity and good capacity retention. It is about 93% after 80 cycles at a charge/discharge rate of 0.3 mA/cm2. When discharged at 0.9 mA/cm2, the obtained capacity retention was about 64% of the capacity at 0.3 mA/cm2. Cathodic interfacial polarization represents the predominant loss in a low-temperature SOFC. In this thesis, several porous nanocomposite electrodes of mixed ionic and electronic conductors (MIEC) with high surface areas were designed and fabricated to improve to minimize the polarization resistance. For the first time, regular, homogeneous and dual porous MIEC electrodes were successfully fabricated using breath figure templating, which is self-assembly of the water droplets in polymer solution. The homogeneous macropores promoted rapid mass transport by decreasing the tortuosity. Further, mesoporous microstructure provided more surface areas for gas adsorption and more TPBs for the electrochemical reactions. The interfacial polarization resistances were 0.94 and 0.39 Ocm 2 at 700 and 750°C, respectively. Furthermore, electrodes consisting of strontium doped lanthanum manganite (LSM) and gadolinium doped ceria (GDC) were developed with a modified sol-gel process for honeycomb SOFCs based on stabilized zirconia electrolytes. The sol gel derived cathodes with fine grain size and large specific surface area, showed much lower interfacial polarization resistances than those prepared by other processing methods. And this process developed strong bonding between the electrode and electrolyte even at low temperatures. The interfacial polarization resistances were 0.65 and 0.16 Ocm 2 at 650 and 750°C, respectively. The mesoscopic regime of overlapping space charge effects had a positive effect on the electrode kinetics. Ceria is a very important catalytic material for fuel reforming in SOFCs and CO poisoning in PEM fuel cells. Especially, the design of a new generation SOFC requires the in-situ reforming of hydrocarbon fuels. In this work, nanostructured ceria was developed via a controlled hydrothermal process in a mixed water-ethanol medium. The microstructure, formation mechanism, and their surface catalytic properties were investigated.

3D printed e-tongue

NASA Astrophysics Data System (ADS)

Gaál, Gabriel; da Silva, Tatiana A.; Gaál, Vladimir; Hensel, Rafael C.; Amaral, Lucas R.; Rodrigues, Varlei; Riul, Antonio

2018-05-01

Nowadays, one of the biggest issues addressed to electronic sensor fabrication is the build-up of efficient electrodes as an alternative way to the expensive, complex and multistage processes required by traditional techniques. Printed electronics arises as an interesting alternative to fulfill this task due to the simplicity and speed to stamp electrodes on various surfaces. Within this context, the Fused Deposition Modeling 3D printing is an emerging, cost-effective and alternative technology to fabricate complex structures that potentiates several fields with more creative ideas and new materials for a rapid prototyping of devices. We show here the fabrication of interdigitated electrodes using a standard home-made CoreXY 3D printer using transparent and graphene-based PLA filaments. Macro 3D printed electrodes were easily assembled within 6 minutes with outstanding reproducibility. The electrodes were also functionalized with different nanostructured thin films via dip-coating Layer-by-Layer technique to develop a 3D printed e-tongue setup. As a proof of concept, the printed e-tongue was applied to soil analysis. A control soil sample was enriched with several macro-nutrients to the plants (N, P, K, S, Mg and Ca) and the discrimination was done by electrical impedance spectroscopy of water solution of the soil samples. The data was analyzed by Principal Component Analysis and the 3D printed sensor distinguished clearly all enriched samples despite the complexity of the soil chemical composition. The 3D printed e-tongue successfully used in soil analysis encourages further investments in developing new sensory tools for precision agriculture and other fields exploiting the simplicity and flexibility offered by the 3D printing techniques.

NANOCI-Nanotechnology Based Cochlear Implant With Gapless Interface to Auditory Neurons.

PubMed

Senn, Pascal; Roccio, Marta; Hahnewald, Stefan; Frick, Claudia; Kwiatkowska, Monika; Ishikawa, Masaaki; Bako, Peter; Li, Hao; Edin, Fredrik; Liu, Wei; Rask-Andersen, Helge; Pyykkö, Ilmari; Zou, Jing; Mannerström, Marika; Keppner, Herbert; Homsy, Alexandra; Laux, Edith; Llera, Miguel; Lellouche, Jean-Paul; Ostrovsky, Stella; Banin, Ehud; Gedanken, Aharon; Perkas, Nina; Wank, Ute; Wiesmüller, Karl-Heinz; Mistrík, Pavel; Benav, Heval; Garnham, Carolyn; Jolly, Claude; Gander, Filippo; Ulrich, Peter; Müller, Marcus; Löwenheim, Hubert

2017-09-01

: Cochlear implants (CI) restore functional hearing in the majority of deaf patients. Despite the tremendous success of these devices, some limitations remain. The bottleneck for optimal electrical stimulation with CI is caused by the anatomical gap between the electrode array and the auditory neurons in the inner ear. As a consequence, current devices are limited through 1) low frequency resolution, hence sub-optimal sound quality and 2), large stimulation currents, hence high energy consumption (responsible for significant battery costs and for impeding the development of fully implantable systems). A recently completed, multinational and interdisciplinary project called NANOCI aimed at overcoming current limitations by creating a gapless interface between auditory nerve fibers and the cochlear implant electrode array. This ambitious goal was achieved in vivo by neurotrophin-induced attraction of neurites through an intracochlear gel-nanomatrix onto a modified nanoCI electrode array located in the scala tympani of deafened guinea pigs. Functionally, the gapless interface led to lower stimulation thresholds and a larger dynamic range in vivo, and to reduced stimulation energy requirement (up to fivefold) in an in vitro model using auditory neurons cultured on multi-electrode arrays. In conclusion, the NANOCI project yielded proof of concept that a gapless interface between auditory neurons and cochlear implant electrode arrays is feasible. These findings may be of relevance for the development of future CI systems with better sound quality and performance and lower energy consumption. The present overview/review paper summarizes the NANOCI project history and highlights achievements of the individual work packages.

An inkjet-printed electrowetting valve for paper-fluidic sensors.

PubMed

Koo, Charmaine K W; He, Fei; Nugen, Sam R

2013-09-07

Paper-fluidic devices have become an emerging trend for micro total analysis systems (microTAS) in the bioengineering field due to their ability to maintain the rapid, sensitive and specific attributes of microfluidic devices. Subsequently, paper-fluidic devices are also more portable, have a lower production cost and are easier to use. However, one of the obstacles in developing paper fluidic devices is the limited ability to control the rate of fluid flow during an assay. In our project, we use electrowetting on dielectrics where a dielectric, which is normally hydrophobic, is polarized and becomes hydrophilic. We have fabricated paper-fluidic devices by inkjet printing and spraying conductive hydrophobic electrodes/valves in conjunction with conductive hydrophilic electrodes which are able to stop the fluid front of phosphate buffered saline (PBS). The hydrophobic valves were then actuated by an applied potential which altered the fluorinated monolayer on the electrode. As the applied potential between the electrodes was increased, the amount of time for the fluid front to pass the valve decreased because the monolayer was altered faster. However, we did not observe significant differences in time as we increased the distance between the electrodes. The valves were also incorporated in a lateral flow assay where the device was used to detect Saccharomyces cerevisiae rRNA sequences. With the ability to control the fluid flow in a paper-fluidic device, more complex and intricate assays can be developed, which not only can be applied in the biomedical, food and environmental fields, but also can be used in low resource settings for the detection of diseases.

Synthesis of layered LiMnO2 as an electrode for rechargeable lithium batteries

NASA Astrophysics Data System (ADS)

Armstrong, A. Robert; Bruce, Peter G.

1996-06-01

RECHARGEABLE lithium batteries can store more than twice as much energy per unit weight and volume as other rechargeable batteries1,2. They contain lithium ions in an electrolyte, which shuttle back and forth between, and are intercalated by, the electrode materials. The first commercially successful rechargeable lithium battery3, introduced by the Sony Corporation in 1990, consists of a carbon-based negative electrode, layered LiCoO2 as the positive electrode, and a non-aqueous liquid electrolyte. The high cost and toxicity of cobalt compounds, however, has prompted a search for alternative materials that intercalate lithium ions. One such is LiMn2O4, which has been much studied as a positive electrode material4-7 the cost of manganese is less than 1% of that of cobalt, and it is less toxic. Here we report the synthesis and electrochemical performance of a new material, layered LiMnO2, which is structurally analogous to LiCoO2. The charge capacity of LiMnO2 (~270mAhg-1) compares well with that of both LiCoO2 and LiMn2O4, and preliminary results indicate good stability over repeated charge-discharge cycles.

Lead zirconate titanate thin films directly on copper electrodes for ferroelectric, dielectric and piezoelectric applications

NASA Astrophysics Data System (ADS)

Kingon, Angus I.; Srinivasan, Sudarsan

2005-03-01

Replacement of noble metal electrodes by base metals significantly lowers the cost of ferroelectric, piezoelectric and dielectric devices. Here, we demonstrate that it is possible to process lead zirconate (Pb(Zr0.52Ti0.48)O3, or PZT) thin films directly on base metal copper foils. We explore the impact of the oxygen partial pressure during processing, and demonstrate that high-quality films and interfaces can be achieved through control of the oxygen partial pressure within a narrow window predicted by thermodynamic stability considerations. This demonstration has broad implications, opening up the possibility of the use of low-cost, high-conductivity copper electrodes for a range of Pb-based perovskite materials, including PZT films in embedded printed circuit board applications for capacitors, varactors and sensors; multilayer PZT piezoelectric stacks; and multilayer dielectric and electrostrictive devices based on lead magnesium niobate-lead titanate. We also point out that the capacitors do not fatigue on repeated switching, unlike those with Pt noble metal electrodes. Instead, they appear to be fatigue-resistant, like capacitors with oxide electrodes. This may have implications for ferroelectric non-volatile memories.

NASA Redox Storage System Development Project

NASA Technical Reports Server (NTRS)

Hagedorn, N. H.

1984-01-01

The Redox Storage System Technology Project was jointly supported by the U.S. Department of Energy and NASA. The objectives of the project were to develop the Redox flow battery concept and to probe its technical and economic viability. The iron and chromium redox couples were selected as the reactants. Membranes and electrodes were developed for the original mode of operating at 25 C with the reactants separated by an ion-exchange membrane. Analytical capabilities and system-level operating concepts were developed and verified in a 1-kW, 13-kWh preprototype system. A subsequent change was made in operating mode, going to 65 C and using mixed reactants. New membranes and a new electrode catalyst were developed, resulting in single cell operation as high as 80 mA/sq cm with energy efficiencies greater than 80 percent. Studies indicate a likely system cost of about $75/kWh. Standard Oil of Ohio (Sohio) has undertaken further development of the Redox system. An exclusive patent license was obtained from NASA by Sohio. Transfer of Redox technology to Sohio is supported by the NASA Technology Utilization Office.

Direct-referencing Two-dimensional-array Digital Microfluidics Using Multi-layer Printed Circuit Board

PubMed Central

Gong, Jian; Kim, Chang-Jin “CJ”

2008-01-01

Digital (i.e. droplet-based) microfluidics, by the electrowetting-on-dielectric (EWOD) mechanism, has shown great potential for a wide range of applications, such as lab-on-a-chip. While most reported EWOD chips use a series of electrode pads essentially in one-dimensional line pattern designed for specific tasks, the desired universal chips allowing user-reconfigurable paths would require the electrode pads in two-dimensional pattern. However, to electrically access the electrode pads independently, conductive lines need to be fabricated underneath the pads in multiple layers, raising a cost issue especially for disposable chip applications. In this article, we report the building of digital microfluidic plates based on a printed-circuit-board (PCB), in which multilayer electrical access lines were created inexpensively using mature PCB technology. However, due to its surface topography and roughness and resulting high resistance against droplet movement, as-fabricated PCB surfaces require unacceptably high (~500 V) voltages unless coated with or immersed in oil. Our goal is EWOD operations of aqueous droplets not only on oil-covered but also on dry surfaces. To meet varying levels of performances, three types of gradually complex post-PCB microfabrication processes are developed and evaluated. By introducing land-grid-array (LGA) sockets in the packaging, a scalable digital microfluidics system with reconfigurable and low-cost chip is also demonstrated. PMID:19234613

Accurate pointing of tungsten welding electrodes

NASA Technical Reports Server (NTRS)

Ziegelmeier, P.

1971-01-01

Thoriated-tungsten is pointed accurately and quickly by using sodium nitrite. Point produced is smooth and no effort is necessary to hold the tungsten rod concentric. The chemically produced point can be used several times longer than ground points. This method reduces time and cost of preparing tungsten electrodes.

Electrode materials: a challenge for the exploitation of protonic solid oxide fuel cells

PubMed Central

Fabbri, Emiliana; Pergolesi, Daniele; Traversa, Enrico

2010-01-01

High temperature proton conductor (HTPC) oxides are attracting extensive attention as electrolyte materials alternative to oxygen-ion conductors for use in solid oxide fuel cells (SOFCs) operating at intermediate temperatures (400–700 °C). The need to lower the operating temperature is dictated by cost reduction for SOFC pervasive use. The major stake for the deployment of this technology is the availability of electrodes able to limit polarization losses at the reduced operation temperature. This review aims to comprehensively describe the state-of-the-art anode and cathode materials that have so far been tested with HTPC oxide electrolytes, offering guidelines and possible strategies to speed up the development of protonic SOFCs. PMID:27877342

Iron-Air Rechargeable Battery: A Robust and Inexpensive Iron-Air Rechargeable Battery for Grid-Scale Energy Storage

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

2010-10-01

GRIDS Project: USC is developing an iron-air rechargeable battery for large-scale energy storage that could help integrate renewable energy sources into the electric grid. Iron-air batteries have the potential to store large amounts of energy at low cost—iron is inexpensive and abundant, while oxygen is freely obtained from the air we breathe. However, current iron-air battery technologies have suffered from low efficiency and short life spans. USC is working to dramatically increase the efficiency of the battery by placing chemical additives on the battery’s iron-based electrode and restructuring the catalysts at the molecular level on the battery’s air-based electrode. Thismore » can help the battery resist degradation and increase life span. The goal of the project is to develop a prototype iron-air battery at significantly cost lower than today’s best commercial batteries.« less

First prototypes of hybrid potassium-ion capacitor (KIC): An innovative, cost-effective energy storage technology for transportation applications

NASA Astrophysics Data System (ADS)

Le Comte, Annaïg; Reynier, Yvan; Vincens, Christophe; Leys, Côme; Azaïs, Philippe

2017-09-01

Hybrid supercapacitors, combining capacitive carbon-based positive electrode with a Li-ion battery-type negative electrode have been developed in the pursuit of increasing the energy density of conventional supercapacitor without impacting the power density. However, lithium-ion capacitors yet hardly meet the specifications of automotive sector. Herein we report for the first time the development of new hybrid potassium-ion capacitor (KIC) technology. Compared to lithium-ion capacitor (LIC) all strategic materials (lithium and copper) have been replaced. Excellent electrochemical performance have been achieved at a pouch cell scale, with cyclability superior to 55 000 cycles at high charge/discharge regime. For the same cell scale, the energy density is doubled compared to conventional supercapacitor up to high power regime (>1.5 kW kg-1). Finally, the technology was successfully scaled up to 18650 format leading to very promising prospects for transportation applications.

Contour integral method for obtaining the self-energy matrices of electrodes in electron transport calculations

NASA Astrophysics Data System (ADS)

Iwase, Shigeru; Futamura, Yasunori; Imakura, Akira; Sakurai, Tetsuya; Tsukamoto, Shigeru; Ono, Tomoya

2018-05-01

We propose an efficient computational method for evaluating the self-energy matrices of electrodes to study ballistic electron transport properties in nanoscale systems. To reduce the high computational cost incurred in large systems, a contour integral eigensolver based on the Sakurai-Sugiura method combined with the shifted biconjugate gradient method is developed to solve an exponential-type eigenvalue problem for complex wave vectors. A remarkable feature of the proposed algorithm is that the numerical procedure is very similar to that of conventional band structure calculations. We implement the developed method in the framework of the real-space higher-order finite-difference scheme with nonlocal pseudopotentials. Numerical tests for a wide variety of materials validate the robustness, accuracy, and efficiency of the proposed method. As an illustration of the method, we present the electron transport property of the freestanding silicene with the line defect originating from the reversed buckled phases.

Electrochemical supercapacitors from conducting polyaniline-graphene platforms.

PubMed

Ashok Kumar, Nanjundan; Baek, Jong-Beom

2014-06-18

Energy storage devices such as electrochemical supercapacitors, with high power and energy densities are required to address the colossal energy requirements against the backdrop of global warming and the looming energy crisis. Nanocarbon, particularly two-dimensional graphene and graphene-based conducting polymer composites are promising electrode materials for such energy storage devices. Owing to their environmental stability, the low cost of polymers with high electroactivity and pseudocapacitance, such composite hybrids are expected to have wide implications in next generation clean and efficient energy systems. In this feature article, an overview of current research and important advances over the past four years on the development of conducting polyaniline (PANI)-graphene based composite electrodes for electrochemical supercapacitors are highlighted. Particular emphasis is made on the design, fabrication and assembly of nanostructured electrode architectures comprising PANI and graphene along with metal oxides/hydroxides and carbon nanotubes. Comments on the challenges and perspectives towards rational design and synthesis of graphene-based conducting polymer composites for energy storage are discussed.

Detection of mercury ions using L-cysteine modified electrodes by anodic stripping voltammetric method

NASA Astrophysics Data System (ADS)

Vanitha, M.; Balasubramanian, N.; Joni, I. Made; Panatarani, Camellia

2018-02-01

The detection of contaminants in wastewater is of massive importance in today's situation as they pose a serious threat to the environment as well as humans. One such vital contaminants is mercury and its compound, the reported mercury detectors grieve from low sensitivity, high cost and slow response. In the present work graphene based electrode material is developed for sensing mercury contaminants in wastewater using electrochemical technique. The synthesized material graphene oxide (GO) modified with L-Cysteine in presence of polyvinylpyrrolidone (PVP) as capping agent was characterized using SEM, TEM and Raman Spectroscopic analysis. It is ascertained from the morphological characterization that the nanocomposite exhibits a spherical morphology. The L-cysteine modified graphene oxide electrode is electrochemically characterized using redox couple [Fe(CN)63-/4-] and electrochemical impedance spectroscopic (EIS) analysis. Electrochemical sensing of Hg (II) ions in solution was done using Square wave anodic stripping voltammetry (SWASV). The incorporation of graphene significantly increases the sensitivity and selectivity towards mercury sensing.

Three-dimensional nitrogen doped holey reduced graphene oxide framework as metal-free counter electrodes for high performance dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Yu, Mei; Zhang, Jindan; Li, Songmei; Meng, Yanbing; Liu, Jianhua

2016-03-01

Three-dimensional nitrogen doped holey reduced graphene oxide framework (NHGF) with hierarchical porosity structure was developed as high-performance metal-free counter electrodes (CEs) for dye-sensitized solar cells (DSSCs). With plenty of exposed active sites, efficient electron and ion transport pathways as well as a high surface hydrophilicity, NHGF-CE exhibits good electrocatalytic performances for I- /I3- redox couple and a low charge transfer resistance (Rct). The Rct of NHGF-CE is 1.46 Ω cm2, which is much lower than that of Pt-CE (4.02 Ω cm2). The DSSC with NHGF-CE reaches a power conversion efficiency of 5.56% and a fill factor of 65.5%, while those of the DSSC with Pt-CE are only 5.45% and 62.3%, respectively. The achievement of the highly efficient 3D structure presents a potential way to fabricate low-cost and metal-free counter electrodes with excellent performance.

Sodium vanadium titanium phosphate electrode for symmetric sodium-ion batteries with high power and long lifespan

PubMed Central

Wang, Dongxue; Bie, Xiaofei; Fu, Qiang; Dixon, Ditty; Bramnik, Natalia; Hu, Yong-Sheng; Fauth, Francois; Wei, Yingjin; Ehrenberg, Helmut; Chen, Gang; Du, Fei

2017-01-01

Sodium-ion batteries operating at ambient temperature hold great promise for use in grid energy storage owing to their significant cost advantages. However, challenges remain in the development of suitable electrode materials to enable long lifespan and high rate capability. Here we report a sodium super-ionic conductor structured electrode, sodium vanadium titanium phosphate, which delivers a high specific capacity of 147 mA h g−1 at a rate of 0.1 C and excellent capacity retentions at high rates. A symmetric sodium-ion full cell demonstrates a superior rate capability with a specific capacity of about 49 mA h g−1 at 20 C rate and ultralong lifetime over 10,000 cycles. Furthermore, in situ synchrotron diffraction and X-ray absorption spectroscopy measurement are carried out to unravel the underlying sodium storage mechanism and charge compensation behaviour. Our results suggest the potential application of symmetric batteries for electrochemical energy storage given the superior rate capability and long cycle life. PMID:28660877

High-Performance Sodium Metal Anodes Enabled by a Bifunctional Potassium Salt.

PubMed

Shi, Qiuwei; Zhong, Yiren; Wu, Min; Wang, Hongzhi; Wang, Hailiang

2018-04-12

Developing Na metal anodes that can be deeply cycled with high efficiency for a long time is a prerequisite for rechargeable Na metal batteries to be practically useful despite their notable advantages in theoretical energy density and potential low cost. Their high chemical reactivity with the electrolyte and tendency for dendrite formation are two major issues limiting the reversibility of Na metal electrodes. In this work, we introduce for the first time potassium bis(trifluoromethylsulfonyl)imide (KTFSI) as a bifunctional electrolyte additive to stabilize Na metal electrodes, in which the TFSI - anions decompose into lithium nitride and oxynitrides to render a desirable solid electrolyte interphase layer while the K + cations preferentially adsorb onto Na protrusions and provide electrostatic shielding to suppress dendritic deposition. Through the cooperation of the cations and anions, we have realized Na metal electrodes that can be deeply cycled at a capacity of 10 mAh cm -2 for hundreds of hours. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Application of a Portable Multi-Analyte Biosensor for Organic Acid Determination in Silage.

PubMed

Pilas, Johanna; Yazici, Yasemen; Selmer, Thorsten; Keusgen, Michael; Schöning, Michael J

2018-05-08

Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media.

Application of a Portable Multi-Analyte Biosensor for Organic Acid Determination in Silage

PubMed Central

Pilas, Johanna; Yazici, Yasemen; Selmer, Thorsten; Keusgen, Michael

2018-01-01

Multi-analyte biosensors may offer the opportunity to perform cost-effective and rapid analysis with reduced sample volume, as compared to electrochemical biosensing of each analyte individually. This work describes the development of an enzyme-based biosensor system for multi-parametric determination of four different organic acids. The biosensor array comprises five working electrodes for simultaneous sensing of ethanol, formate, d-lactate, and l-lactate, and an integrated counter electrode. Storage stability of the biosensor was evaluated under different conditions (stored at +4 °C in buffer solution and dry at −21 °C, +4 °C, and room temperature) over a period of 140 days. After repeated and regular application, the individual sensing electrodes exhibited the best stability when stored at −21 °C. Furthermore, measurements in silage samples (maize and sugarcane silage) were conducted with the portable biosensor system. Comparison with a conventional photometric technique demonstrated successful employment for rapid monitoring of complex media. PMID:29738487

Sodium vanadium titanium phosphate electrode for symmetric sodium-ion batteries with high power and long lifespan.

PubMed

Wang, Dongxue; Bie, Xiaofei; Fu, Qiang; Dixon, Ditty; Bramnik, Natalia; Hu, Yong-Sheng; Fauth, Francois; Wei, Yingjin; Ehrenberg, Helmut; Chen, Gang; Du, Fei

2017-06-29

Sodium-ion batteries operating at ambient temperature hold great promise for use in grid energy storage owing to their significant cost advantages. However, challenges remain in the development of suitable electrode materials to enable long lifespan and high rate capability. Here we report a sodium super-ionic conductor structured electrode, sodium vanadium titanium phosphate, which delivers a high specific capacity of 147 mA h g -1 at a rate of 0.1 C and excellent capacity retentions at high rates. A symmetric sodium-ion full cell demonstrates a superior rate capability with a specific capacity of about 49 mA h g -1 at 20 C rate and ultralong lifetime over 10,000 cycles. Furthermore, in situ synchrotron diffraction and X-ray absorption spectroscopy measurement are carried out to unravel the underlying sodium storage mechanism and charge compensation behaviour. Our results suggest the potential application of symmetric batteries for electrochemical energy storage given the superior rate capability and long cycle life.

An improved biosensor for acetaldehyde determination using a bienzymatic strategy at poly(neutral red) modified carbon film electrodes.

PubMed

Ghica, Mariana Emilia; Pauliukaite, Rasa; Marchand, Nicolas; Devic, Eric; Brett, Christopher M A

2007-05-15

Improved biosensors for acetaldehyde determination have been developed using a bienzymatic strategy, based on a mediator-modified carbon film electrode and co-immobilisation of NADH oxidase and aldehyde dehydrogenase. Modification of the carbon film electrode with poly(neutral red) mediator resulted in a sensitive, low-cost and reliable NADH detector. Immobilisation of the enzymes was performed using encapsulation in a sol-gel matrix or cross-linking with glutaraldehyde. The bienzymatic biosensors were characterized by studying the influence of pH, applied potential and co-factors. The sol-gel and glutaraldehyde biosensors showed a linear response up to 60 microM and 100 microM, respectively, with detection limits of 2.6 microM and 3.3 microM and sensitivities were 1.7 microA mM(-1) and 5.6 microA mM(-1). The optimised biosensors showed good stability and good selectivity and have been tested for application for the determination of acetaldehyde in natural samples such as wine.

Direct laser immobilization of photosynthetic material on screen printed electrodes for amperometric biosensor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boutopoulos, Christos; Zergioti, Ioanna; Touloupakis, Eleftherios

This letter demonstrates the direct laser printing of photosynthetic material onto low cost nonfunctionalized screen printed electrodes for the fabrication of photosynthesis-based amperometric biosensors. The high kinetic energy of the transferred material induces direct immobilization of the thylakoids onto the electrodes without the use of linkers. This type of immobilization is able to establish efficient electrochemical contact between proteins and electrode, stabilizing the photosynthetic biomolecule and transporting electrons to the solid state device with high efficiency. The functionality of the laser printed biosensors was evaluated by the detection of a common herbicide such as Linuron.

Oxidized Ni/Au Transparent Electrode in Efficient CH3 NH3 PbI3 Perovskite/Fullerene Planar Heterojunction Hybrid Solar Cells.

PubMed

Lai, Wei-Chih; Lin, Kun-Wei; Wang, Yuan-Ting; Chiang, Tsung-Yu; Chen, Peter; Guo, Tzung-Fang

2016-05-01

The successful application of a Ni/Au transparent electrode for fabricating efficient perovskite-based solar cells is demonstrated. Through interdiffusion of the Ni/Au bilayer, Au forms an interconnected metallic network structure as the transparent electrode. Ni diffuses to the bilayer surface and oxidizes into NiOx becoming an appropriate electrode interlayer. These ITO- and PSS-free devices have potential applications in the design of future cost-effective, low-weight, and stable solar cells. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Emerging Prototype Sodium-Ion Full Cells with Nanostructured Electrode Materials.

PubMed

Ren, Wenhao; Zhu, Zixuan; An, Qinyou; Mai, Liqiang

2017-06-01

Due to steadily increasing energy consumption, the demand of renewable energy sources is more urgent than ever. Sodium-ion batteries (SIBs) have emerged as a cost-effective alternative because of the earth abundance of Na resources and their competitive electrochemical behaviors. Before practical application, it is essential to establish a bridge between the sodium half-cell and the commercial battery from a full cell perspective. An overview of the major challenges, most recent advances, and outlooks of non-aqueous and aqueous sodium-ion full cells (SIFCs) is presented. Considering the intimate relationship between SIFCs and electrode materials, including structure, composition and mutual matching principle, both the advance of various prototype SIFCs and the electrochemistry development of nanostructured electrode materials are reviewed. It is noted that a series of SIFCs combined with layered oxides and hard carbon are capable of providing a high specific gravimetric energy above 200 Wh kg -1 , and an NaCrO 2 //hard carbon full cell is able to deliver a high rate capability over 100 C. To achieve industrialization of SIBs, more systematic work should focus on electrode construction, component compatibility, and battery technologies. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Microwave synthesis of three-dimensional nickel cobalt sulfide nanosheets grown on nickel foam for high-performance asymmetric supercapacitors.

PubMed

Wang, Fangping; Li, Guifang; Zheng, Jinfeng; Ma, Jing; Yang, Caixia; Wang, Qizhao

2018-04-15

A facile and cost-effective microwave method is developed to prepare ternary nickel cobalt sulfide (NiCo 2 S 4 ) interconnected nanosheet arrays on nickel foam (NF). When acting as an electrochemical supercapacitor electrode material, the as-prepared NiCo 2 S 4 /NF shows a high specific capacitance of 1502 F g -1 at a current density of 1 A g -1 , and outstanding cycling stability of 91% capacitance retention after 8000 cycles. In addition, a asymmetric supercapacitor (ASC) is composed of NiCo 2 S 4 /NF as positive electrode and activated carbon as negative electrode, which exhibits a high energy density of 34.7 W h kg -1 at a power density of 750 W kg -1 and long-term cyclic stability (83.7% capacity retention after 8000 cycles). Even at a high power density of 15 kW kg -1 , it still remains an energy density of 17.9 W h kg -1 , which is able to light up a light-emitting diode. These findings provide a new and facile approach to fabricate high-performance electrode for supercapacitors. Copyright © 2018 Elsevier Inc. All rights reserved.

Development of an Arduino-based electrical impedance tomography system with application to dam internal erosion detection

NASA Astrophysics Data System (ADS)

Masi, Matteo; Ferdos, Farzad; Losito, Gabriella; Solari, Luca

2016-04-01

Electrical Impedance Tomography (EIT) is a technique for the imaging of the electrical properties of conductive materials. In EIT, the spatial distribution of the electrical resistivity or electrical conductivity within a domain is reconstructed using measurements made with electrodes placed at the boundaries of the domain. Data acquisition is typically made by applying an electrical current to the object under investigation using a set of electrodes, and measuring the developed voltage between the other electrodes. The tomographic image is then obtained using an inversion algorithm. This work describes the implementation of a simple and low cost 3D EIT measurement system suitable for laboratory-scale studies. The system was specifically developed for the time-lapse imaging of soil samples subjected to erosion processes during laboratory tests. The tests reproduce the process of internal erosion of soil particles by water flow within a granular media; this process is one of the most common causes of failure of earthen levees and embankment dams. The measurements needed strict requirements of speed and accuracy due to the varying time scale and magnitude of these processes. The developed EIT system consists of a PC which controls I/O cards (multiplexers) through the Arduino micro-controller, an external current generator, a digital acquisition device (DAQ), a power supply and the electrodes. The ease of programming of the Arduino interface greatly helped the implementation of custom acquisition software, increasing the overall flexibility of the system and the creation of specific acquisition schemes and configurations. The system works with a multi-electrode configuration of up to 48 channels but it was designed to be upgraded to an arbitrary large number of electrodes by connecting additional multiplexer cards (> 96 electrodes). The acquisition was optimized for multi-channel measurements so that the overall time of acquisition is dramatically reduced compared to the single channel instrumentation. The accuracy and operation were tested under different conditions. The results from preliminary tests show that the system is able to clearly identify objects discriminated by different resistivity. Furthermore, measurements carried out during internal erosion simulations demonstrate that even small variations in the electrical resistivity can be captured and these changes can be related to the erosion processes.

Nanostructured mesoporous materials for lithium-ion battery applications

NASA Astrophysics Data System (ADS)

Balaya, P.; Saravanan, K.; Hariharan, S.; Ramar, V.; Lee, H. S.; Kuezma, M.; Devaraj, S.; Nagaraju, D. H.; Ananthanarayanan, K.; Mason, C. W.

2011-06-01

The Energy crisis happens to be one of the greatest challenges we are facing today. In this view, much effort has been made in developing new, cost effective, environmentally friendly energy conversion and storage devices. The performance of such devices is fundamentally related to material properties. Hence, innovative materials engineering is important in solving the energy crisis problem. One such innovation in materials engineering is porous materials for energy storage. Porous electrode materials for lithium-ion batteries (LIBs) offer a high degree of electrolyte-electrode wettability, thus enhancing the electrochemical activity within the material. Among the porous materials, mesoporous materials draw special attention, owing to shorter diffusion lengths for Li+ and electronic movement. Nanostructured mesoporous materials also offer better packing density compared to their nanostructured counterparts such as nanopowders, nanowires, nanotubes etc., thus opening a window for developing electrode materials with high volumetric energy densities. This would directly translate into a scenario of building batteries which are much lighter than today's commercial LIBs. In this article, the authors present a simple, soft template approach for preparing both cathode and anode materials with high packing density for LIBs. The impact of porosity on the electrochemical storage performance is highlighted.

Phosphate Detection through a Cost-Effective Carbon Black Nanoparticle-Modified Screen-Printed Electrode Embedded in a Continuous Flow System.

PubMed

Talarico, Daria; Cinti, Stefano; Arduini, Fabiana; Amine, Aziz; Moscone, Danila; Palleschi, Giuseppe

2015-07-07

An automatable flow system for the continuous and long-term monitoring of the phosphate level has been developed using an amperometric detection method based on the use of a miniaturized sensor. This method is based on the monitoring of an electroactive complex obtained by the reaction between phosphate and molybdate that is consequently reduced at the electrode surface. The use of a screen-printed electrode modified with carbon black nanoparticles (CBNPs) leads to the quantification of the complex at low potential, because CBNPs are capable of electrocatalitically enhancing the phosphomolybdate complex reduction at +125 mV versus Ag/AgCl without fouling problems. The developed system also incorporates reagents and waste storage and is connected to a portable potentiostat for rapid detection and quantification of phosphate. Main analytical parameters, such as working potential, reagent concentration, type of cell, and flow rate, were evaluated and optimized. This system was characterized by a low detection limit (6 μM). Interference studies were carried out. Good recovery percentages comprised between 89 and 131.5% were achieved in different water sources, highlighting its suitability for field measurements.

Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace

PubMed Central

Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T.

2016-01-01

Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr6+). Elemental manganese, nickel, chromium, iron emissions per unit length of weld and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered and analyzed by inductively-coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr6+. GMAW processes used were Surface Tension Transfer™, Regulated Metal Deposition™, Cold Metal Transfer™, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr6+ ranged from 50 to 7800 μg/min, and Cr6+ generation rates per g electrode ranged from 1 to 270μg/g. Elemental Cr generation rates spanned 13 to 330μg/g. Manganese emission rates ranged from 50 to 300μg/g. Nickel emission rates ranged from 4 to140 μg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as 5 times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this study can substantially reduce fume, Cr6+, manganese and costs relative to SMAW, the most commonly used welding process, and several have exceptional capabilities for reducing emissions. PMID:26267301

Profiling stainless steel welding processes to reduce fume emissions, hexavalent chromium emissions and operating costs in the workplace.

PubMed

Keane, Michael; Siert, Arlen; Stone, Samuel; Chen, Bean T

2016-01-01

Nine gas metal arc welding (GMAW) processes for stainless steel were assessed for fume generation rates, fume generation rates per g of electrode consumed, and emission rates for hexavalent chromium (Cr(6+)). Elemental manganese, nickel, chromium, iron emissions per unit length of weld, and labor plus consumables costs were similarly measured. Flux-cored arc welding and shielded metal arc (SMAW) processes were also studied. The objective was to identify the best welding processes for reducing workplace exposures, and estimate costs for all processes. Using a conical chamber, fumes were collected, weighed, recovered, and analyzed by inductively coupled atomic emission spectroscopy for metals, and by ion chromatography for Cr(6+). GMAW processes used were Surface Tension Transfer, Regulated Metal Deposition, Cold Metal Transfer, short-circuit, axial spray, and pulsed spray modes. Flux-cored welding used gas shielding; SMAW used E308 rods. Costs were estimated as dollars per m length of a ¼ in (6.3 mm) thick horizontal butt weld; equipment costs were estimated as ratios of new equipment costs to a 250 ampere capacity SMAW welding machine. Results indicate a broad range of fume emission factors for the processes studied. Fume emission rates per g of electrode were lowest for GMAW processes such as pulsed-spray mode (0.2 mg/g), and highest for SMAW (8 mg fume/g electrode). Emission rates of Cr(6+) ranged from 50-7800 µg/min, and Cr(6+) generation rates per g electrode ranged from 1-270 µg/g. Elemental Cr generation rates spanned 13-330 µg/g. Manganese emission rates ranged from 50-300 µg/g. Nickel emission rates ranged from 4-140 µg/g. Labor and consumables costs ranged from $3.15 (GMAW pulsed spray) to $7.40 (SMAW) per meter of finished weld, and were measured or estimated for all 11 processes tested. Equipment costs for some processes may be as much as five times the cost of a typical SMAW welding machine. The results show that all of the GMAW processes in this study can substantially reduce fume, Cr(6+), manganese and costs relative to SMAW, the most commonly used welding process, and several have exceptional capabilities for reducing emissions.

A Low-Cost, In Situ Resistivity and Temperature Monitoring System

EPA Science Inventory

We present a low-cost, reliable method for long-term in situ autonomous monitoring of subsurface resistivity and temperature in a shallow, moderately heterogeneous subsurface. Probes, to be left in situ, were constructed at relatively low cost with close electrode spacing. Once i...

AMPEROMETRIC THICK-FILM STRIP ELECTRODES FOR MONITORING ORGANOPHOSPHATE NERVE AGENTS BASED ON IMMOBILIZED ORGANOPHOSPHORUS HYDROLASE. (R823663)

EPA Science Inventory

An amperometric biosensor based on the immobilization of organophosphorus hydrolase
(OPH) onto screen-printed carbon electrodes is shown useful for the rapid, sensitive, and low-cost
detection of organophosphate (OP) nerve agents. The sensor relies upon the sensitive and ra...

Lithium metal doped electrodes for lithium-ion rechargeable chemistry

DOEpatents

Liu, Gao; Battaglia, Vince; Wang, Lei

2016-09-13

An embodiment of the invention combines the superior performance of a polyvinylidene difluoride (PVDF) or polyethyleneoxide (POE) binder, the strong binding force of a styrene-butadiene (SBR) binder, and a source of lithium ions in the form of solid lithium metal powder (SLMP) to form an electrode system that has improved performance as compared to PVDF/SBR binder based electrodes. This invention will provide a new way to achieve improved results at a much reduced cost.

Printed Graphene Electrochemical Biosensors Fabricated by Inkjet Maskless Lithography for Rapid and Sensitive Detection of Organophosphates.

PubMed

Hondred, John A; Breger, Joyce C; Alves, Nathan J; Trammell, Scott A; Walper, Scott A; Medintz, Igor L; Claussen, Jonathan C

2018-04-04

Solution phase printing of graphene-based electrodes has recently become an attractive low-cost, scalable manufacturing technique to create in-field electrochemical biosensors. Here, we report a graphene-based electrode developed via inkjet maskless lithography (IML) for the direct and rapid monitoring of triple-O linked phosphonate organophosphates (OPs); these constitute the active compounds found in chemical warfare agents and pesticides that exhibit acute toxicity as well as long-term pollution to soils and waterways. The IML-printed graphene electrode is nano/microstructured with a 1000 mW benchtop laser engraver and electrochemically deposited platinum nanoparticles (dia. ∼25 nm) to improve its electrical conductivity (sheet resistance decreased from ∼10 000 to 100 Ω/sq), surface area, and electroactive nature for subsequent enzyme functionalization and biosensing. The enzyme phosphotriesterase (PTE) was conjugated to the electrode surface via glutaraldehyde cross-linking. The resulting biosensor was able to rapidly measure (5 s response time) the insecticide paraoxon (a model OP) with a low detection limit (3 nM), and high sensitivity (370 nA/μM) with negligible interference from similar nerve agents. Moreover, the biosensor exhibited high reusability (average of 0.3% decrease in sensitivity per sensing event), stability (90% anodic current signal retention over 1000 s), longevity (70% retained sensitivity after 8 weeks), and the ability to selectively sense OP in actual soil and water samples. Hence, this work presents a scalable printed graphene manufacturing technique that can be used to create OP biosensors that are suitable for in-field applications as well as, more generally, for low-cost biosensor test strips that could be incorporated into wearable or disposable sensing paradigms.

State-of-the-art characterization techniques for advanced lithium-ion batteries

NASA Astrophysics Data System (ADS)

Lu, Jun; Wu, Tianpin; Amine, Khalil

2017-03-01

To meet future needs for industries from personal devices to automobiles, state-of-the-art rechargeable lithium-ion batteries will require both improved durability and lowered costs. To enhance battery performance and lifetime, understanding electrode degradation mechanisms is of critical importance. Various advanced in situ and operando characterization tools developed during the past few years have proven indispensable for optimizing battery materials, understanding cell degradation mechanisms, and ultimately improving the overall battery performance. Here we review recent progress in the development and application of advanced characterization techniques such as in situ transmission electron microscopy for high-performance lithium-ion batteries. Using three representative electrode systems—layered metal oxides, Li-rich layered oxides and Si-based or Sn-based alloys—we discuss how these tools help researchers understand the battery process and design better battery systems. We also summarize the application of the characterization techniques to lithium-sulfur and lithium-air batteries and highlight the importance of those techniques in the development of next-generation batteries.

Recent Progress on Flexible and Wearable Supercapacitors.

PubMed

Xue, Qi; Sun, Jinfeng; Huang, Yan; Zhu, Minshen; Pei, Zengxia; Li, Hongfei; Wang, Yukun; Li, Na; Zhang, Haiyan; Zhi, Chunyi

2017-12-01

Recently, wearable electronic devices including electrical sensors, flexible displays, and health monitors have received considerable attention and experienced rapid progress. Wearable supercapacitors attract tremendous attention mainly due to their high stability, low cost, fast charging/discharging, and high efficiency; properties that render them value for developing fully flexible devices. In this Concept, the recent achievements and advances made in flexible and wearable supercapacitors are presented, especially highlighting the promising performances of yarn/fiber-shaped and planar supercapacitors. On the basis of their working mechanism, electrode materials including carbon-based materials, metal oxide-based materials, and conductive polymers with an emphasis on the performance-optimization method are introduced. The latest representative techniques and active materials of recently developed supercapacitors with superior performance are summarized. Furthermore, the designs of 1D and 2D electrodes are discussed according to their electrically conductive supporting materials. Finally, conclusions, challenges, and perspective in optimizing and developing the electrochemical performance and function of wearable supercapacitors for their practical utility are addressed. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

DOE PAGES

Li, Jianlin; Du, Zhijia; Ruther, Rose E.; ...

2017-06-12

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by ~70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. Here, this article discusses three major aspects formore » cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.« less

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Jianlin; Du, Zhijia; Ruther, Rose E.

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by ~70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. Here, this article discusses three major aspects formore » cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.« less

Toward Low-Cost, High-Energy Density, and High-Power Density Lithium-Ion Batteries

NASA Astrophysics Data System (ADS)

Li, Jianlin; Du, Zhijia; Ruther, Rose E.; AN, Seong Jin; David, Lamuel Abraham; Hays, Kevin; Wood, Marissa; Phillip, Nathan D.; Sheng, Yangping; Mao, Chengyu; Kalnaus, Sergiy; Daniel, Claus; Wood, David L.

2017-09-01

Reducing cost and increasing energy density are two barriers for widespread application of lithium-ion batteries in electric vehicles. Although the cost of electric vehicle batteries has been reduced by 70% from 2008 to 2015, the current battery pack cost (268/kWh in 2015) is still >2 times what the USABC targets (125/kWh). Even though many advancements in cell chemistry have been realized since the lithium-ion battery was first commercialized in 1991, few major breakthroughs have occurred in the past decade. Therefore, future cost reduction will rely on cell manufacturing and broader market acceptance. This article discusses three major aspects for cost reduction: (1) quality control to minimize scrap rate in cell manufacturing; (2) novel electrode processing and engineering to reduce processing cost and increase energy density and throughputs; and (3) material development and optimization for lithium-ion batteries with high-energy density. Insights on increasing energy and power densities of lithium-ion batteries are also addressed.

Modeling and simulation of the fluid flow in wire electrochemical machining with rotating tool (wire ECM)

NASA Astrophysics Data System (ADS)

Klocke, F.; Herrig, T.; Zeis, M.; Klink, A.

2017-10-01

Combining the working principle of electrochemical machining (ECM) with a universal rotating tool, like a wire, could manage lots of challenges of the classical ECM sinking process. Such a wire-ECM process could be able to machine flexible and efficient 2.5-dimensional geometries like fir tree slots in turbine discs. Nowadays, established manufacturing technologies for slotting turbine discs are broaching and wire electrical discharge machining (wire EDM). Nevertheless, high requirements on surface integrity of turbine parts need cost intensive process development and - in case of wire-EDM - trim cuts to reduce the heat affected rim zone. Due to the process specific advantages, ECM is an attractive alternative manufacturing technology and is getting more and more relevant for sinking applications within the last few years. But ECM is also opposed with high costs for process development and complex electrolyte flow devices. In the past, few studies dealt with the development of a wire ECM process to meet these challenges. However, previous concepts of wire ECM were only suitable for micro machining applications. Due to insufficient flushing concepts the application of the process for machining macro geometries failed. Therefore, this paper presents the modeling and simulation of a new flushing approach for process assessment. The suitability of a rotating structured wire electrode in combination with an axial flushing for electrodes with high aspect ratios is investigated and discussed.

Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet.

PubMed

Sohbatzadeh, F; Eshghabadi, M; Mohsenpour, T

2018-06-29

The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

Composite Transparent Electrode of Graphene Nanowalls and Silver Nanowires on Micropyramidal Si for High-Efficiency Schottky Junction Solar Cells.

PubMed

Jiao, Tianpeng; Liu, Jian; Wei, Dapeng; Feng, Yanhui; Song, Xuefen; Shi, Haofei; Jia, Shuming; Sun, Wentao; Du, Chunlei

2015-09-16

The conventional graphene-silicon Schottky junction solar cell inevitably involves the graphene growth and transfer process, which results in complicated technology, loss of quality of the graphene, extra cost, and environmental unfriendliness. Moreover, the conventional transfer method is not well suited to conformationally coat graphene on a three-dimensional (3D) silicon surface. Thus, worse interfacial conditions are inevitable. In this work, we directly grow graphene nanowalls (GNWs) onto the micropyramidal silicon (MP) by the plasma-enhanced chemical vapor deposition method. By controlling growth time, the cell exhibits optimal pristine photovoltaic performance of 3.8%. Furthermore, we improve the conductivity of the GNW electrode by introducing the silver nanowire (AgNW) network, which could achieve lower sheet resistance. An efficiency of 6.6% has been obtained for the AgNWs-GNWs-MP solar cell without any chemical doping. Meanwhile, the cell exhibits excellent stability exposed to air. Our studies show a promising way to develop simple-technology, low-cost, high-efficiency, and stable Schottky junction solar cells.

Controllable synthesizing DLC nano structures as a super hydrophobic layer on cotton fabric using a low-cost ethanol electrospray-assisted atmospheric plasma jet

NASA Astrophysics Data System (ADS)

Sohbatzadeh, F.; Eshghabadi, M.; Mohsenpour, T.

2018-06-01

The surface modification of cotton samples was carried out using a liquid (ethanol) electrospray-assisted atmospheric pressure plasma jet. X-ray photoelectron spectroscopy (XPS) and Raman analysis confirmed the successful deposition of diamond like carbon (DLC) nano structures on the cotton surface. The super hydrophobic state of the samples was probed by contact angle measurements. The water repellency of the layers was tuned by controlling the voltage applied to the electrospray electrode. An investigation of the morphological and chemical structures of the samples by field emission scanning microscopy, atomic force microscopy (AFM) and XPS indicated that the physical shape, distribution and amorphization of the DLC structures were successfully adjusted and improved by applying a voltage to the electrospray electrode. Finally wash durability of the best sample was tested for 35 cycles. In this work, the use of a well-developed atmospheric pressure plasma jet for DLC nano structures deposition can enable a promising environmentally friendly and low-cost approach for modifying cotton fabrics for super water-repellent fabric applications.

Roll-to-roll production of spray coated N-doped carbon nanotube electrodes for supercapacitors

NASA Astrophysics Data System (ADS)

Karakaya, Mehmet; Zhu, Jingyi; Raghavendra, Achyut J.; Podila, Ramakrishna; Parler, Samuel G.; Kaplan, James P.; Rao, Apparao M.

2014-12-01

Although carbon nanomaterials are being increasingly used in energy storage, there has been a lack of inexpensive, continuous, and scalable synthesis methods. Here, we present a scalable roll-to-roll (R2R) spray coating process for synthesizing randomly oriented multi-walled carbon nanotubes electrodes on Al foils. The coin and jellyroll type supercapacitors comprised such electrodes yield high power densities (˜700 mW/cm3) and energy densities (1 mW h/cm3) on par with Li-ion thin film batteries. These devices exhibit excellent cycle stability with no loss in performance over more than a thousand cycles. Our cost analysis shows that the R2R spray coating process can produce supercapacitors with 10 times the energy density of conventional activated carbon devices at ˜17% lower cost.

Organic light-emitting diodes using novel embedded al gird transparent electrodes

NASA Astrophysics Data System (ADS)

Peng, Cuiyun; Chen, Changbo; Guo, Kunping; Tian, Zhenghao; Zhu, Wenqing; Xu, Tao; Wei, Bin

2017-03-01

This work demonstrates a novel transparent electrode using embedded Al grids fabricated by a simple and cost-effective approach using photolithography and wet etching. The optical and electrical properties of Al grids versus grid geometry have been systematically investigated, it was found that Al grids exhibited a low sheet resistance of 70 Ω □-1 and a light transmission of 69% at 550 nm with advantages in terms of processing conditions and material cost as well as potential to large scale fabrication. Indium Tin Oxide-free green organic light-emitting diodes (OLED) based on Al grids transparent electrodes was demonstrated, yielding a power efficiency >15 lm W-1 and current efficiency >39 cd A-1 at a brightness of 2396 cd m-2. Furthermore, a reduced efficiency roll-off and higher brightness have been achieved compared with ITO-base device.

A microfluidic chip platform with electrochemical carbon nanotube electrodes for pre-clinical evaluation of antibiotics nanocapsules.

PubMed

Hong, Chien-Chong; Wang, Chih-Ying; Peng, Kuo-Ti; Chu, I-Ming

2011-04-15

This paper presents a microfluidic chip platform with electrochemical carbon nanotube electrodes for preclinical evaluation of antibiotics nanocapsules. Currently, there has been an increasing interest in the development of nanocapsules for drug delivery applications for localized treatments of diseases. So far, the methods to detect antibiotics are liquid chromatography (LC), high performance liquid chromatography (HPLC), mass spectroscopy (MS). These conventional instruments are bulky, expensive, not ease of access, and talented operator required. In order to help the development of nanocapsules and understand drug release profile before planning the clinical experiments, it is important to set up a biosensing platform which could monitor and evaluate the real-time drug release profile of nanocapsules with high sensitivity and long-term measurement ability. In this work, a microfluidic chip platform with electrochemical carbon nanotube electrodes has been developed and characterized for rapid detection of antibiotics teicoplanin nanocapsules. Multi-walled carbon nanotubes are used to modify the gold electrode surfaces to enhance the performance of the electrochemical biosensors. Experimental results show that the limit of detection of the developed platform using carbon nanotubes electrodes is 0.1 μg/ml with a linear range from 1 μg/ml to 10 μg/ml. The sensitivity of the developed system is 0.023 mA ml/μg at 37°C. The drug release profile of teicoplanin nanocapsules in PBS shows that the antibiotics nanocapsules significantly increased the release of drug on the 4th day, measuring 0.4858 μg/(ml hr). The release of drug from the antibiotics nanocapsules reached 34.98 μg/ml on the 7th day. The results showed a similar trend compared with the measurement result using the HPLC instrument. Compared with the traditional HPLC measurements, the electrochemical sensing platform we developed measures results with increased flexibility in controlling experimental factors for long-term preclinical measurement of nanocapsules in real time and at low cost. Copyright © 2011 Elsevier B.V. All rights reserved.

A Low-Cost Inkjet-Printed Aptamer-Based Electrochemical Biosensor for the Selective Detection of Lysozyme.

PubMed

Khan, Niazul Islam; Maddaus, Alec G; Song, Edward

2018-01-15

Recently, inkjet-printing has gained increased popularity in applications such as flexible electronics and disposable sensors, as well as in wearable sensors because of its multifarious advantages. This work presents a novel, low-cost immobilization technique using inkjet-printing for the development of an aptamer-based biosensor for the detection of lysozyme, an important biomarker in various disease diagnosis. The strong affinity between the carbon nanotube (CNT) and the single-stranded DNA is exploited to immobilize the aptamers onto the working electrode by printing the ink containing the dispersion of CNT-aptamer complex. The inkjet-printing method enables aptamer density control, as well as high resolution patternability. Our developed sensor shows a detection limit of 90 ng/mL with high target selectivity against other proteins. The sensor also demonstrates a shelf-life for a reasonable period. This technology has potential for applications in developing low-cost point-of-care diagnostic testing kits for home healthcare.

Three-Dimensional Hierarchically Mesoporous ZnCo2 O4 Nanowires Grown on Graphene/Sponge Foam for High-Performance, Flexible, All-Solid-State Supercapacitors.

PubMed

Moon, In Kyu; Yoon, Seonno; Oh, Jungwoo

2017-01-12

To achieve high energy storage on three-dimensional (3D) structures at low cost, materials with high power and long cycle life characteristics have to be developed. We synthesized ZnCo 2 O 4 /reduced graphene oxide (rGO) binary composites in commercial sponges. ZnCo 2 O 4 nanosheets were grown on the surface of GO/sponge through a hydrothermal reaction. The resulting flexible, free-standing ZnCo 2 O 4 /rGO/sponge electrodes were used as the electrodes in a symmetric supercapacitor. ZnCo 2 O 4 /rGO/sponge electrodes have a large specific capacitance of 1116.6 F g -1 at a scan rate of 2 mV s -1 in aqueous electrolyte. The all-solid-state flexible supercapacitor is assembled based on ZnCo 2 O 4 /rGO/sponge electrodes, which show excellent electrochemical performances with a specific capacitance of 143 F g -1 at a current density of 1 A g -1 . The as-fabricated supercapacitor also exhibits excellent cycling stability (93.4 % capacitance retention after 5000 cycles) and exceptional mechanical flexibility. These results demonstrate the potential of ZnCo 2 O 4 /rGO/sponge as an electrode in flexible, high-performance supercapacitors. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Nonlinear Conductivities and Electrochemical Performances of LiNi 0.5 Co 0.2 Mn 0.3 O 2 Electrodes

DOE PAGES

Su, Xin; Ha, Seonbaek; Ishwait, Manar B.; ...

2016-01-01

There is increasing research attention on optimizing the carbon black nanoparticles’ structure and loading procedure for improving conductivities and thus, electrochemical performances of cathodes in lithium-ion batteries. Recently, LiNi 0.5Co 0.2Mn 0.3O 2 (NCM523) has been actively investigated due to its larger specific capacity and lower cost compared to conventional cathode materials. Presented here is a high energy density NCM523 cathode obtained by reducing the carbon content using the state-of-the-art carbon nanoparticles developed at Cabot Corporation. It is the first time that the nonlinear conductivity of NCM523 electrodes has been discovered, which is significantly impacted by the dispersion and surface crystalline quality of carbon black nanoparticles, especially when the loading of carbon black is only 1 wt%. The nonlinear conductivity of the cathodes can dramatically affect their electrochemical performances at high rates (more » $$\\geqq$$3C), which is close to the tunneling saturated current. In addition, there is no discernable difference in terms of the rate and cycle performance of the NCM523 electrodes, when reducing the loading of novel carbon black nanoparticles from 5 wt% to 1 wt% in the cathode. Therefore, the energy density of the electrode can be increased by 9% by using existing commercially available electrode materials.« less

All electrochemical process for synthesis of Si coating on TiO2 nanotubes as durable negative electrode material for lithium ion batteries

NASA Astrophysics Data System (ADS)

Nemaga, Abirdu Woreka; Mallet, Jeremy; Michel, Jean; Guery, Claude; Molinari, Michael; Morcrette, Mathieu

2018-07-01

The development of high energy density Li-ion batteries requires to look for electrode materials with high capacity while keeping their stability upon cycling. In this study, amorphous silicon (a-Si) thin film deposited on self-organized TiO2 nanotubes is investigated as negative electrode for Li-ion batteries. Nanostructured composite negative electrodes were fabricated by a two-step cost effective electrochemical process. Firstly, self-organized TiO2 nanotube arrays were synthesised by anodizing of Ti foil. Subsequently, thanks to the use of room temperature ionic liquid, conformal Si layer was electrodeposited on the TiO2 nanotubes to achieve the synthesis of nanostructured a-Si/TiO2 nanotube composite negative electrodes. The influence of the Si loading as well as the crystallinity of the TiO2 nanotubes have been studied in terms of capacity and cyclic stability. For an optimized a-Si loading, it is shown that the amorphous state for the TiO2 nanotubes enables to get stable lithiation and delithiation with a total areal charge capacity of about 0.32 mA h cm-2 with improved capacity retention of about 84% after 50 cycles, while a-Si on crystalline TiO2 nanotubes shows poor cyclic stability independently from the Si loading.

First-principles study of mixed eldfellite compounds Nax(Fe1/2M1/2) (SO4)2 (x=0-2, M = Mn, Co, Ni): A new family of high electrode potential cathodes for the sodium-ion battery

NASA Astrophysics Data System (ADS)

Ri, Gum-Chol; Choe, Song-Hyok; Yu, Chol-Jun

2018-02-01

Natural abundance of sodium and its similar behavior to lithium triggered recent extensive studies of cost-effective sodium-ion batteries (SIBs) for large-scale energy storage systems. A challenge is to develop electrode materials with a high electrode potential, specific capacity and a good rate capability. In this work we propose mixed eldfellite compounds Nax(Fe1/2M1/2) (SO4)2 (x = 0-2, M = Mn, Co, Ni) as a new family of high electrode potential cathodes of SIBs and present their material properties predicted by first-principles calculations. The structural optimizations show that these materials have significantly small volume expansion rates below 5% upon Na insertion/desertion with negative Na binding energies. Through the electronic structure calculations, we find band insulating properties and hole (and/or electron) polaron hoping as a possible mechanism for the charge transfer. Especially we confirm the high electrode voltages over 4 V with reasonably high specific capacities. We also investigate the sodium ion mobility by estimating plausible diffusion pathways and calculating the corresponding activation barriers, demonstrating the reasonably fast migrations of sodium ions during the operation. Our calculation results indicate that these mixed eldfellite compounds can be suitable materials for high performance SIB cathodes.

Turning an environmental problem into an opportunity: potential use of biochar derived from a harmful marine biomass named Cladophora glomerata as anode electrode for Li-ion batteries.

PubMed

Salimi, Pejman; Javadian, Soheila; Norouzi, Omid; Gharibi, Hussein

2017-12-01

The electrochemical performance of lithium ion battery was enhanced by using biochar derived from Cladophora glomerata (C. glomerata) as widespread green macroalgae in most areas of the Iran's Caspian sea coast. By the utilization of the structure of the biochar, micro-/macro-ordered porous carbon with olive-shaped structure was successfully achieved through pyrolysis at 500 °C, which is the optimal temperature for biofuel production, and was activated with HCl. The biochar and HCl treatment biochar (HTB) were applied as anode electrode in lithium ion batteries. Then, electrochemical measurements were conducted on the electrodes via galvanostatic charge-discharge, cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS) analyses. The electrochemical results indicated a higher specific discharge capacity (700 mAh g -1 ) and good cycling stability for HTB at the current density of 0.1 A g -1 as compared to the biochar. The reason that HTB electrode works better than the biochar could be due to the higher surface area, formation functional groups, removal impurities, and formation some micropores after HCl treatment. The biochar derived from marine biomass and treatment process developed here could provide a promising path for the low-cost, renewable, and environmentally friendly electrode materials. Graphical abstract Algal-biochar into Li-ion Battery.

A flexible mesoporous Li4Ti5O12-rGO nanocomposite film as free-standing anode for high rate lithium ion batteries

NASA Astrophysics Data System (ADS)

Zhu, Kunxu; Gao, Hanyang; Hu, Guoxin

2018-01-01

Advanced flexible electrode is crucial in the development of flexible energy storage devices for emerging wearable and portable electronics. Herein, a free-standing flexible mesoporous Li4Ti5O12-rGO (LTO-rGO) nanocomposite film is rationally designed and fabricated for lithium ion batteries (LIBs). This efficient synthesis involves the growth of lithium titanate hydrate (LTH) precursors on the graphene oxide (GO) by a hydrothermal reaction, assembly into LTH-GO film by vacuum filtration with some extra GO added, and subsequent conversion into LTO-rGO nanocomposite film through calcination. When rGO content in the LTO-rGO film is set, the addition sequence of GO is found to affect its textural and mechanical properties. The resultant free-standing LTO-rGO electrode, taking advantages of high Li4Ti5O12 loading of 73.9%, mesoporous layer-stacked channels with good electron/ion conductivity, good mechanical strength, and enlarged electrode/electrolyte contact area, delivers excellent electrochemical performance (e.g., specific capacity of 135.4 mAh g-1 at 40 C) over the electrode of conventional configuration. Moreover, no organic but all inorganic reagents are used in the synthesis, offering an eco-friendly, cost-efficient, and easily scalable way to fabricate binder-free flexible electrode for LIBs.

Impact of uniform electrode current distribution on ETF. [Engineering Test Facility MHD generator

NASA Technical Reports Server (NTRS)

Bents, D. J.

1982-01-01

A basic reason for the complexity and sheer volume of electrode consolidation hardware in the MHD ETF Powertrain system is the channel electrode current distribution, which is non-uniform. If the channel design is altered to provide uniform electrode current distribution, the amount of hardware required decreases considerably, but at the possible expense of degraded channel performance. This paper explains the design impacts on the ETF electrode consolidation network associated with uniform channel electrode current distribution, and presents the alternate consolidation designs which occur. They are compared to the baseline (non-uniform current) design with respect to performance, and hardware requirements. A rational basis is presented for comparing the requirements for the different designs and the savings that result from uniform current distribution. Performance and cost impacts upon the combined cycle plant are discussed.

Gold leaf counter electrodes for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Shimada, Kazuhiro; Toyoda, Takeshi

2018-03-01

In this study, a gold leaf 100 nm thin film is used as the counter electrode in dye-sensitized solar cells. The traditional method of hammering gold foil to obtain a thin gold leaf, which requires only small amounts of gold, was employed. The gold leaf was then attached to the substrate using an adhesive to produce the gold electrode. The proposed approach for fabricating counter electrodes is demonstrated to be facile and cost-effective, as opposed to existing techniques. Compared with electrodes prepared with gold foil and sputtered gold, the gold leaf counter electrode demonstrates higher catalytic activity with a cobalt-complex electrolyte and higher cell efficiency. The origin of the improved performance was investigated by surface morphology examination (scanning electron microscopy), various electrochemical analyses (cyclic voltammetry, linear sweep voltammetry, and electrochemical impedance spectroscopy), and crystalline analysis (X-ray diffractometry).

Self-assembled monolayers of n-alkanethiols suppress hydrogen evolution and increase the efficiency of rechargeable iron battery electrodes.

PubMed

Malkhandi, Souradip; Yang, Bo; Manohar, Aswin K; Prakash, G K Surya; Narayanan, S R

2013-01-09

Iron-based rechargeable batteries, because of their low cost, eco-friendliness, and durability, are extremely attractive for large-scale energy storage. A principal challenge in the deployment of these batteries is their relatively low electrical efficiency. The low efficiency is due to parasitic hydrogen evolution that occurs on the iron electrode during charging and idle stand. In this study, we demonstrate for the first time that linear alkanethiols are very effective in suppressing hydrogen evolution on alkaline iron battery electrodes. The alkanethiols form self-assembled monolayers on the iron electrodes. The degree of suppression of hydrogen evolution by the alkanethiols was found to be greater than 90%, and the effectiveness of the alkanethiol increased with the chain length. Through steady-state potentiostatic polarization studies and impedance measurements on high-purity iron disk electrodes, we show that the self-assembly of alkanethiols suppressed the parasitic reaction by reducing the interfacial area available for the electrochemical reaction. We have modeled the effect of chain length of the alkanethiol on the surface coverage, charge-transfer resistance, and double-layer capacitance of the interface using a simple model that also yields a value for the interchain interaction energy. We have verified the improvement in charging efficiency resulting from the use of the alkanethiols in practical rechargeable iron battery electrodes. The results of battery tests indicate that alkanethiols yield among the highest faradaic efficiencies reported for the rechargeable iron electrodes, enabling the prospect of a large-scale energy storage solution based on low-cost iron-based rechargeable batteries.

Facile synthesis of nitrogen-doped reduced graphene oxide as an efficient counter electrode for dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Wei, Liguo; Wang, Ping; Yang, Yulin; Luo, Ruidong; Li, Jinqi; Gu, Xiaohu; Zhan, Zhaoshun; Dong, Yongli; Song, Weina; Fan, Ruiqing

2018-04-01

A nitrogen-doped reduced graphene oxide (N-RGO) nanosheet was synthesized by a simple hydrothermal method and characterized by X-ray diffraction, Raman spectroscopy, X-ray photoelectron spectroscopy, and scanning electrode microscopy. After being deposited as counter electrode film for dye-sensitized solar cells (DSSCs), it is found that the synthesized N-RGO nanosheet has smaller charge-transfer resistance and better electrocatalytic activity towards reduction of triiodide than the reduced graphene oxide (RGO) nanosheet. Consequently, the DSSCs based on the N-RGO counter electrode achieve an energy conversion efficiency of 4.26%, which is higher than that of the RGO counter electrode (2.85%) prepared under the same conditions, and comparable to the value (5.21%) obtained with the Pt counter electrode as a reference. This N-RGO counter electrode offers the advantages of not only saving the cost of Pt itself but also simplifying the process of counter electrode preparation. Therefore, an inexpensive N-RGO nanosheet is a promising counter electrode material to replace noble metal Pt. [Figure not available: see fulltext.

Thick electrodes for Li-ion batteries: A model based analysis

NASA Astrophysics Data System (ADS)

Danner, Timo; Singh, Madhav; Hein, Simon; Kaiser, Jörg; Hahn, Horst; Latz, Arnulf

2016-12-01

Li-ion batteries are commonly used in portable electronic devices due to their outstanding energy and power density. A remaining issue which hinders the breakthrough e.g. in the automotive sector is the high production cost. For low power applications, such as stationary storage, batteries with electrodes thicker than 300 μm were suggested. High energy densities can be attained with only a few electrode layers which reduces production time and cost. However, mass and charge transport limitations can be severe at already small C-rates due to long transport pathways. In this article we use a detailed 3D micro-structure resolved model to investigate limiting factors for battery performance. The model is parametrized with data from the literature and dedicated experiments and shows good qualitative agreement with experimental discharge curves of thick NMC-graphite Li-ion batteries. The model is used to assess the effect of inhomogeneities in carbon black distribution and gives answers to the possible occurrence of lithium plating during battery charge. Based on our simulations we can predict optimal operation strategies and improved design concepts for future Li-ion batteries employing thick electrodes.

Nano-engineered flexible pH sensor for point-of-care urease detection

NASA Astrophysics Data System (ADS)

Sardarinejad, A.; Maurya, D. K.; Tay, C. Y.; Marshall, B. J.; Alameh, K.

2015-12-01

Accurate pH monitoring is crucial for many applications, such as, water quality monitoring, blood monitoring, chemical and biological analyses, environmental monitoring and clinical diagnostic. The most common technique for pH measurement is based on the use of conventional glass pH electrodes. Glass electrodes have several limitations, such as mechanical fragility, large size, limited shapes and high cost, making them impractical for implementation as Lab-onchips and pH sensor capsules. Various metal oxides, such as RuO2, IrO2, TiO2, SnO2, Ta2O5 and PdO have recently been proposed for the realization of pH sensing electrodes. Specifically, ruthenium oxide exhibits unique properties including thermal stability, excellent corrosion resistance, low hysteresis high sensitivity, and low resistivity. In this paper, we demonstrate the concept of a miniaturized ion selective electrode (ISE) based pH sensor for point-of-care urease monitoring. The sensor comprises a thin film RuO2 on platinum sensing electrode, deposited using E-beam and R.F. magnetron sputtering, in conjunction with an integrated Ag/AgCl reference electrode. The performance and characterization of the developed pH/urea sensors in terms of sensitivity, resolution, reversibility and hysteresis are investigated. Experimental results show a linear potential-versus-urea-concentration response for urea concentrations in the range 0 - 180 mg/ml. Experimental results demonstrate super-Nernstian slopes in the range of 64.33 mV/pH - 73.83 mV/pH for RF sputtered RuO2 on platinum sensing electrode using a 80%:20% Ar:O2 gas ratio. The RuO2 sensor exhibits stable operation and fast dynamic response, making it attractive for in vivo use, wearable and flexible biomedical sensing applications.

Corrosion resistant positive electrode for high-temperature, secondary electrochemical cell

DOEpatents

Otto, Neil C.; Warner, Barry T.; Smaga, John A.; Battles, James E.

1983-01-01

The corrosion rate of low carbon steel within a positive electrode of a high-temperature, secondary electrochemical cell that includes FeS as active material is substantially reduced by incorporating therein finely divided iron powder in stoichiometric excess to the amount required to form FeS in the fully charged electrode. The cell typically includes an alkali metal or alkaline earth metal as negative electrode active material and a molten metal halide salt as electrolyte. The excess iron permits use of inexpensive carbon steel alloys that are substantially free of the costly corrosion resistant elements chromium, nickel and molybdenum while avoiding shorten cell life resulting from high corrosion rates.

Corrosion resistant positive electrode for high-temperature, secondary electrochemical cell

DOEpatents

Otto, N.C.; Warner, B.T.; Smaga, J.A.; Battles, J.E.

1982-07-07

The corrosion rate of low carbon steel within a positive electrode of a high-temperature, secondary electrochemical cell that includes FeS as active material is substantially reduced by incorporating therein finely divided iron powder in stoichiometric excess to the amount required to form FeS in the fully charged electrode. The cell typically includes an alkali metal or alkaline earth metal as negative electrode active material and a molten metal halide salt as electrolyte. The excess iron permits use of inexpensive carbon steel alloys that are substantially free of the costly corrosion resistant elements chromium, nickel and molybdenum while avoiding shorten cell life resulting from high corrosion rates.

Organometal halide perovskite light-emitting diodes with laminated carbon nanotube electrodes

NASA Astrophysics Data System (ADS)

Shan, Xin; Bade, Sri Ganesh R.; Geske, Thomas; Davis, Melissa; Smith, Rachel; Yu, Zhibin

2017-08-01

Organometal halide perovskite light-emitting diodes (LEDs) with laminated carbon nanotube (CNT) electrodes are reported. The LEDs have an indium tin oxide (ITO) bottom electrode, a screen printed methylammonium lead tribromide (MAPbBr3)/polymer composite thin film as the emissive layer, and laminated CNT as the top electrode. The devices can be turned on at 2.2 V, reaching a brightness of 4,960 cd m-2 and a current efficiency of 1.54 cd A-1 at 6.9 V. The greatly simplified fabrication process in this work can potentially lead to the scalable manufacturing of large size and low cost LED panels in the future.

The Investigation and Development of Low Cost Hardware Components for Proton-Exchange Membrane Fuel Cells - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

George A. Marchetti

1999-12-15

Proton exchange membrane (PEM) fuel cell components, which would have a low-cost structure in mass production, were fabricated and tested. A fuel cell electrode structure, comprising a thin layer of graphite (50 microns) and a front-loaded platinum catalyst layer (600 angstroms), was shown to produce significant power densities. In addition, a PEM bipolar plate, comprising flexible graphite, carbon cloth flow-fields and an integrated polymer gasket, was fabricated. Power densities of a two-cell unit using this inexpensive bipolar plate architecture were shown to be comparable to state-of-the-art bipolar plates.

A multiscale simulation technique for molecular electronics: design of a directed self-assembled molecular n-bit shift register memory device.

PubMed

Lambropoulos, Nicholas A; Reimers, Jeffrey R; Crossley, Maxwell J; Hush, Noel S; Silverbrook, Kia

2013-12-20

A general method useful in molecular electronics design is developed that integrates modelling on the nano-scale (using quantum-chemical software) and on the micro-scale (using finite-element methods). It is applied to the design of an n-bit shift register memory that could conceivably be built using accessible technologies. To achieve this, the entire complex structure of the device would be built to atomic precision using feedback-controlled lithography to provide atomic-level control of silicon devices, controlled wet-chemical synthesis of molecular insulating pillars above the silicon, and controlled wet-chemical self-assembly of modular molecular devices to these pillars that connect to external metal electrodes (leads). The shift register consists of n connected cells that read data from an input electrode, pass it sequentially between the cells under the control of two external clock electrodes, and deliver it finally to an output device. The proposed cells are trimeric oligoporphyrin units whose internal states are manipulated to provide functionality, covalently connected to other cells via dipeptide linkages. Signals from the clock electrodes are conveyed by oligoporphyrin molecular wires, and μ-oxo porphyrin insulating columns are used as the supporting pillars. The developed multiscale modelling technique is applied to determine the characteristics of this molecular device, with in particular utilization of the inverted region for molecular electron-transfer processes shown to facilitate latching and control using exceptionally low energy costs per logic operation compared to standard CMOS shift register technology.

A multiscale simulation technique for molecular electronics: design of a directed self-assembled molecular n-bit shift register memory device

NASA Astrophysics Data System (ADS)

Lambropoulos, Nicholas A.; Reimers, Jeffrey R.; Crossley, Maxwell J.; Hush, Noel S.; Silverbrook, Kia

2013-12-01

A general method useful in molecular electronics design is developed that integrates modelling on the nano-scale (using quantum-chemical software) and on the micro-scale (using finite-element methods). It is applied to the design of an n-bit shift register memory that could conceivably be built using accessible technologies. To achieve this, the entire complex structure of the device would be built to atomic precision using feedback-controlled lithography to provide atomic-level control of silicon devices, controlled wet-chemical synthesis of molecular insulating pillars above the silicon, and controlled wet-chemical self-assembly of modular molecular devices to these pillars that connect to external metal electrodes (leads). The shift register consists of n connected cells that read data from an input electrode, pass it sequentially between the cells under the control of two external clock electrodes, and deliver it finally to an output device. The proposed cells are trimeric oligoporphyrin units whose internal states are manipulated to provide functionality, covalently connected to other cells via dipeptide linkages. Signals from the clock electrodes are conveyed by oligoporphyrin molecular wires, and μ-oxo porphyrin insulating columns are used as the supporting pillars. The developed multiscale modelling technique is applied to determine the characteristics of this molecular device, with in particular utilization of the inverted region for molecular electron-transfer processes shown to facilitate latching and control using exceptionally low energy costs per logic operation compared to standard CMOS shift register technology.

Electrochemical Glucose Biosensor Based on Glucose Oxidase Displayed on Yeast Surface.

PubMed

Wang, Hongwei; Lang, Qiaolin; Liang, Bo; Liu, Aihua

2015-01-01

The conventional enzyme-based biosensor requires chemical or physical immobilization of purified enzymes on electrode surface, which often results in loss of enzyme activity and/or fractions immobilized over time. It is also costly. A major advantage of yeast surface display is that it enables the direct utilization of whole cell catalysts with eukaryote-produced proteins being displayed on the cell surface, providing an economic alternative to traditional production of purified enzymes. Herein, we describe the details of the display of glucose oxidase (GOx) on yeast cell surface and its application in the development of electrochemical glucose sensor. In order to achieve a direct electrochemistry of GOx, the entire cell catalyst (yeast-GOx) was immobilized together with multiwalled carbon nanotubes on the electrode, which allowed sensitive and selective glucose detection.

Reactor concepts for bioelectrochemical syntheses and energy conversion.

PubMed

Krieg, Thomas; Sydow, Anne; Schröder, Uwe; Schrader, Jens; Holtmann, Dirk

2014-12-01

In bioelectrochemical systems (BESs) at least one electrode reaction is catalyzed by microorganisms or isolated enzymes. One of the existing challenges for BESs is shifting the technology towards industrial use and engineering reactor systems at adequate scales. Due to the fact that most BESs are usually deployed in the production of large-volume but low-value products (e.g., energy, fuels, and bulk chemicals), investment and operating costs must be minimized. Recent advances in reactor concepts for different BESs, in particular biofuel cells and electrosynthesis, are summarized in this review including electrode development and first applications on a technical scale. A better understanding of the impact of reactor components on the performance of the reaction system is an important step towards commercialization of BESs. Copyright © 2014 Elsevier Ltd. All rights reserved.

Development of electron beam ion source for nanoprocess using highly charged ions

NASA Astrophysics Data System (ADS)

Sakurai, Makoto; Nakajima, Fumiharu; Fukumoto, Takunori; Nakamura, Nobuyuki; Ohtani, Shunsuke; Mashiko, Shinro; Sakaue, Hiroyuki

2005-07-01

Highly charged ion is useful to produce nanostructure on various materials, and is key tool to realize single ion implantation technique. On such demands for the application to nanotechnology, we have designed an electron bean ion source. The design stresses on the volume of drift tubes where highly charged ions are confined and the efficiency of ion extraction from the drift tube through collector electrode in order to obtain intense ion beam as much as possible. The ion source uses a discrete superconducting magnet cooled by a closed-cycle refrigerator in order to reduce the running costs and to simplify the operating procedures. The electrodes of electron gun, drift tubes, and collector are enclosed in ultrahigh vacuum tube that is inserted into the bore of the magnet system.

Efficient Conservative Reformulation Schemes for Lithium Intercalation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Urisanga, PC; Rife, D; De, S

Porous electrode theory coupled with transport and reaction mechanisms is a widely used technique to model Li-ion batteries employing an appropriate discretization or approximation for solid phase diffusion with electrode particles. One of the major difficulties in simulating Li-ion battery models is the need to account for solid phase diffusion in a second radial dimension r, which increases the computation time/cost to a great extent. Various methods that reduce the computational cost have been introduced to treat this phenomenon, but most of them do not guarantee mass conservation. The aim of this paper is to introduce an inherently mass conservingmore » yet computationally efficient method for solid phase diffusion based on Lobatto III A quadrature. This paper also presents coupling of the new solid phase reformulation scheme with a macro-homogeneous porous electrode theory based pseudo 20 model for Li-ion battery. (C) The Author(s) 2015. Published by ECS. All rights reserved.« less

Fabrication of a Miniature Multi-Parameter Sensor Chip for Water Quality Assessment.

PubMed

Zhou, Bo; Bian, Chao; Tong, Jianhua; Xia, Shanhong

2017-01-14

Water contamination is a main inducement of human diseases. It is an important step to monitor the water quality in the water distribution system. Due to the features of large size, high cost, and complicated structure of traditional water determination sensors and devices, it is difficult to realize real-time water monitoring on a large scale. In this paper, we present a multi-parameter sensor chip, which is miniature, low-cost, and robust, to detect the pH, conductivity, and temperature of water simultaneously. The sensor chip was fabricated using micro-electro-mechanical system (MEMS) techniques. Iridium oxide film was electrodeposited as the pH-sensing material. The atomic ratio of Ir(III) to Ir(IV) is about 1.38 according to the X-ray photoelectron spectroscopy (XPS) analysis. The pH sensing electrode showed super-Nernstian response (-67.60 mV/pH) and good linearity (R² = 0.9997), in the range of pH 2.22 to pH 11.81. KCl-agar and epoxy were used as the electrolyte layer and liquid junction for the solid-state reference electrode, respectively, and its potential stability in deionized water was 56 h. The conductivity cell exhibited a linear determination range from 21.43 μ S / cm to 1.99 mS / cm , and the electrode constant was 1.566 cm -1 . Sensitivity of the temperature sensor was 5.46 Ω / ° C . The results indicate that the developed sensor chip has potential application in water quality measurements.

Magnetron sputtered diamond-like carbon microelectrodes for on-chip measurement of quantal catecholamine release from cells

PubMed Central

Gao, Yuanfang; Chen, Xiaohui; Gupta, Sanju; Gillis, Kevin D.; Gangopadhyay, Shubhra

2008-01-01

Carbon electrodes are widely used in electrochemistry due to their low cost, wide potential window, and low and stable background noise. Carbon-fiber electrodes (CFE) are commonly used to electrochemically measure “quantal” catecholamine release via exocytosis from individual cells, but it is difficult to integrate CFEs into lab-on-a-chip devices. Here we report the development of nitrogen doped diamond-like carbon (DLC:N) microelectrodes on a chip to monitor quantal release of catecholamines from cells. Advantages of DLC:N microelectrodes are that they are batch producible at low cost, and are harder and more durable than graphite films. The DLC:N microelectrodes were prepared by a magnetron sputtering process with nitrogen doping. The 30 μm by 40 μm DLC:N microelectrodes were patterned onto microscope glass slides by photolithography and lift-off technology. The properties of the DLC:N microelectrodes were characterized by AFM, Raman spectroscopy and cyclic voltammetry. Quantal catecholamine release was recorded amperometrically from bovine adrenal chromaffin cells on the DLC:N microelectrodes. Amperometric spikes due to quantal release of catecholamines were similar in amplitude and area as those recorded using CFEs and the background current and noise levels of microchip DLC:N electrodes were also comparable to CFEs. Therefore, DLC:N microelectrodes are suitable for microchip-based high-throughput measurement of quantal exocytosis with applications in basic research, drug discovery and cell-based biosensors. PMID:18493856

Exploiting enzyme catalysis in ultra-low ion strength media for impedance biosensing of avian influenza virus using a bare interdigitated electrode.

PubMed

Fu, Yingchun; Callaway, Zachary; Lum, Jacob; Wang, Ronghui; Lin, Jianhan; Li, Yanbin

2014-02-18

Enzyme catalysis is broadly used in various fields but generally applied in media with high ion strength. Here, we propose the exploitation of enzymatic catalysis in ultra-low ion strength media to induce ion strength increase for developing a novel impedance biosensing method. Avian influenza virus H5N1, a serious worldwide threat to poultry and human health, was adopted as the analyte. Magnetic beads were modified with H5N1-specific aptamer to capture the H5N1 virus. This was followed by binding concanavalin A (ConA), glucose oxidase (GOx), and Au nanoparticles (AuNPs) to create bionanocomposites through a ConA-glycan interaction. The yielded sandwich complex was transferred to a glucose solution to trigger an enzymatic reaction to produce gluconic acid, which ionized to increase the ion strength of the solution, thus decreasing the impedance on a screen-printed interdigitated array electrode. This method took advantages of the high efficiency of enzymatic catalysis and the high susceptibility of electrochemical impedance on the ion strength and endowed the biosensor with high sensitivity and a detection limit of 8 × 10(-4) HAU in 200 μL sample, which was magnitudes lower than that of some analogues based on biosensing methods. Furthermore, the proposed method required only a bare electrode for measurements of ion strength change and had negligible change on the surficial properties of the electrode, though some modification of magnetic beads/Au nanoparticles and the construction of a sandwich complex were still needed. This helped to avoid the drawbacks of commonly used electrode immobilization methods. The merit for this method makes it highly useful and promising for applications. The proposed method may create new possibilities in the broad and well-developed enzymatic catalysis fields and find applications in developing sensitive, rapid, low-cost, and easy-to-operate biosensing and biocatalysis devices.

High Electrocatalytic Activity of Vertically Aligned Single-Walled Carbon Nanotubes towards Sulfide Redox Shuttles.

PubMed

Hao, Feng; Dong, Pei; Zhang, Jing; Zhang, Yongchang; Loya, Phillip E; Hauge, Robert H; Li, Jianbao; Lou, Jun; Lin, Hong

2012-01-01

Vertically aligned single-walled carbon nanotubes (VASWCNTs) have been successfully transferred onto transparent conducting oxide glass and implemented as efficient low-cost, platinum-free counter electrode in sulfide -mediated dye-sensitized solar cells (DSCs), featuring notably improved electrocatalytic activity toward thiolate/disulfide redox shuttle over conventional Pt counter electrodes. Impressively, device with VASWCNTs counter electrode demonstrates a high fill factor of 0.68 and power conversion efficiency up to 5.25%, which is significantly higher than 0.56 and 3.49% for that with a conventional Pt electrode. Moreover, VASWCNTs counter electrode produces a charge transfer resistance of only 21.22 Ω towards aqueous polysulfide electrolyte commonly applied in quantum dots-sensitized solar cells (QDSCs), which is several orders of magnitude lower than that of a typical Pt electrode. Therefore, VASWCNTs counter electrodes are believed to be a versatile candidate for further improvement of the power conversion efficiency of other iodine-free redox couple based DSCs and polysulfide electrolyte based QDSCs.

Bifacial Perovskite Solar Cells Featuring Semitransparent Electrodes.

PubMed

Hanmandlu, Chintam; Chen, Chien-Yu; Boopathi, Karunakara Moorthy; Lin, Hao-Wu; Lai, Chao-Sung; Chu, Chih-Wei

2017-09-27

Inorganic-organic hybrid perovskite solar cells (PSCs) are promising devices for providing future clean energy because of their low cost, ease of fabrication, and high efficiencies, similar to those of silicon solar cells. These materials have been investigated for their potential use in bifacial PSCs, which can absorb light from both sides of the electrodes. Here, we fabricated bifacial PSCs featuring transparent BCP/Ag/MoO 3 rear electrodes, which we formed through low-temperature processing using thermal evaporation methods. We employed a comprehensive optical distribution program to calculate the distributions of the optical field intensities with constant thicknesses of the absorbing layer in the top electrode configuration. The best PSC having a transparent BCP/Ag/MoO 3 electrode achieved PCEs of 13.49% and 9.61% when illuminated from the sides of the indium tin oxide and BCP/Ag/MoO 3 electrodes, respectively. We observed significant power enhancement when operating this PSC using mirror reflectors and bifacial light illumination from both sides of the electrodes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Woodford, William

This document is the final technical report from 24M Technologies on the project titled: Low Cost, Structurally Advanced Novel Electrode and Cell Manufacturing. All of the program milestones and deliverables were completed during the performance of the award. Specific accomplishments are 1) 24M demonstrated the processability and electrochemical performance of semi-solid electrodes with active volume contents increased by 10% relative to the program baseline; 2) electrode-level metrics, quality, and yield were demonstrated at an 80 cm 2 electrode footprint; 3) these electrodes were integrated into cells with consistent capacities and impedances, including cells delivered to Argonne National Laboratory for independentmore » testing; 4) those processes were scaled to a large-format (> 260 cm 2) electrode footprint and quality and yield were demonstrated; 5) a high-volume manufacturing approach for large-format electrode fabrication was demonstrated; and 6) large-format cells (> 100 Ah capacity) were prototyped with consistent capacity and impedance, including cells which were delivered to Argonne National Laboratory for independent testing.« less

Evaluation of non-rigid registration parameters for atlas-based segmentation of CT images of human cochlea

NASA Astrophysics Data System (ADS)

Elfarnawany, Mai; Alam, S. Riyahi; Agrawal, Sumit K.; Ladak, Hanif M.

2017-02-01

Cochlear implant surgery is a hearing restoration procedure for patients with profound hearing loss. In this surgery, an electrode is inserted into the cochlea to stimulate the auditory nerve and restore the patient's hearing. Clinical computed tomography (CT) images are used for planning and evaluation of electrode placement, but their low resolution limits the visualization of internal cochlear structures. Therefore, high resolution micro-CT images are used to develop atlas-based segmentation methods to extract these nonvisible anatomical features in clinical CT images. Accurate registration of the high and low resolution CT images is a prerequisite for reliable atlas-based segmentation. In this study, we evaluate and compare different non-rigid B-spline registration parameters using micro-CT and clinical CT images of five cadaveric human cochleae. The varying registration parameters are cost function (normalized correlation (NC), mutual information and mean square error), interpolation method (linear, windowed-sinc and B-spline) and sampling percentage (1%, 10% and 100%). We compare the registration results visually and quantitatively using the Dice similarity coefficient (DSC), Hausdorff distance (HD) and absolute percentage error in cochlear volume. Using MI or MSE cost functions and linear or windowed-sinc interpolation resulted in visually undesirable deformation of internal cochlear structures. Quantitatively, the transforms using 100% sampling percentage yielded the highest DSC and smallest HD (0.828+/-0.021 and 0.25+/-0.09mm respectively). Therefore, B-spline registration with cost function: NC, interpolation: B-spline and sampling percentage: moments 100% can be the foundation of developing an optimized atlas-based segmentation algorithm of intracochlear structures in clinical CT images.

Highly transparent, low-haze, hybrid cellulose nanopaper as electrodes for flexible electronics

Treesearch

Xuezhu Xu; Jian Zhou; Long Jiang; Gilles Lubineau; Tienkhee Ng; Boon S. Ooi; Hsien-Yu Liao; Chao Shen; Long Chen; Junyong Zhu

2016-01-01

Paper is an excellent candidate to replace plastics as a substrate for flexible electronics due to its low cost, renewability and flexibility. Cellulose nanopaper (CNP), a new type of paper made of nanosized cellulose fibers, is a promising substrate material for transparent and flexible electrodes due to its potentially high transparency and high mechanical strength....

Open-Source Low-Cost Wireless Potentiometric Instrument for pH Determination Experiments

ERIC Educational Resources Information Center

Jin, Hao; Qin, Yiheng; Pan, Si; Alam, Arif U.; Dong, Shurong; Ghosh, Raja; Deen, M. Jamal

2018-01-01

pH determination is an essential experiment in many chemistry laboratories. It requires a potentiometric instrument with extremely low input bias current to accurately measure the voltage between a pH sensing electrode and a reference electrode. In this technology report, we propose an open-source potentiometric instrument for pH determination…

Additively Manufactured Pneumatically Driven Skin Electrodes.

PubMed

Schubert, Martin; Schmidt, Martin; Wolter, Paul; Malberg, Hagen; Zaunseder, Sebastian; Bock, Karlheinz

2017-12-23

Telemedicine focuses on improving the quality of health care, particularly in out-of-hospital settings. One of the most important applications is the continuous remote monitoring of vital parameters. Long-term monitoring of biopotentials requires skin-electrodes. State-of-the-art electrodes such as Ag/AgCl wet electrodes lead, especially during long-term application, to complications, e.g., skin irritations. This paper presents a low-cost, on-demand electrode approach for future long-term applications. The fully printed module comprises a polymeric substrate with electrodes on a flexible membrane, which establishes skin contact only for short time in case of measurement. The membranes that produce airtight seals for pressure chambers can be pneumatically dilated and pressed onto the skin to ensure good contact, and subsequently retracted. The dilatation depends on the pressure and membrane thickness, which has been tested up to 150 kPa. The electrodes were fabricated in screen and inkjet printing technology, and compared during exemplary electrodermal activity measurement (EDA). The results show less amplitude compared to conventional EDA electrodes but similar behavior. Because of the manufacturing process the module enables high individuality for future applications.

Multi-Scale Ordered Cell Structure for Cost Effective Production of Hydrogen by HTWS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Elangovan, Elango; Rao, Ranjeet; Colella, Whitney

Production of hydrogen using an electrochemical device provides for large scale, high efficiency conversion and storage of electrical energy. When renewable electricity is used for conversion of steam to hydrogen, a low-cost and low emissions pathway to hydrogen production emerges. This project was intended to demonstrate a high efficiency High Temperature Water Splitting (HTWS) stack for the electrochemical production of low cost H2. The innovations investigated address the limitations of the state of the art through the use of a novel architecture that introduces macro-features to provide mechanical support of a thin electrolyte, and micro-features of the electrodes to lowermore » polarization losses. The approach also utilizes a combination of unique sets of fabrication options that are scalable to achieve manufacturing cost objectives. The development of HTWS process and device is guided by techno-economic and life cycle analyses.« less

Nano-porous electrode systems by colloidal lithography for sensitive electrochemical detection: fabrication technology and properties

NASA Astrophysics Data System (ADS)

Lohmüller, Theobald; Müller, Ulrich; Breisch, Stefanie; Nisch, Wilfried; Rudorf, Ralf; Schuhmann, Wolfgang; Neugebauer, Sebastian; Kaczor, Markus; Linke, Stephan; Lechner, Sebastian; Spatz, Joachim; Stelzle, Martin

2008-11-01

A porous metal-insulator-metal sensor system was developed with the ultimate goal of enhancing the sensitivity of electrochemical sensors by taking advantage of redox cycling of electro active molecules between closely spaced electrodes. The novel fabrication technology is based on thin film deposition in combination with colloidal self-assembly and reactive ion etching to create micro- or nanopores. This cost effective approach is advantageous compared to common interdigitated electrode arrays (IDA) since it does not require high definition lithography technology. Spin-coating and random particle deposition, combined with a new sublimation process are discussed as competing strategies to generate monolayers of colloidal spheres. Metal-insulator-metal layer systems with low leakage currents < 10 pA and an insulator thickness as low as 100 nm were obtained at high yield (typically > 90%). We also discuss possible causes of sensor failure with respect to critical fabrication processes. Short circuits which could occur during or as a result of the pore etching process were investigated in detail. Infrared microscopy in combination with focused ion beam etching/SEM were used to reveal a defect mechanism creating interconnects and increased leakage current between the top and bottom electrodes. Redox cycling provides for amplification factors of >100. A general applicability for electrochemical diagnostic assays is therefore anticipated.

Determination of functionalized gold nanoparticles incorporated in hydrophilic and hydrophobic microenvironments by surface modification of quartz crystal microbalance

NASA Astrophysics Data System (ADS)

Wu, Tsui-Hsun; Liao, Shu-Chuan; Chen, Ying-Fang; Huang, Yi-You; Wei, Yi-Syuan; Tu, Shu-Ju; Chen, Ko-Shao

2013-06-01

In this study, plasma deposition methods were used to immobilize Au electrode of a quartz crystal microbalance (QCM) to create different microenvironments for mass measurement of various modified Au nanoparticles (AuNPs). AuNPs were modified by 11-mercaptoundecanoic acid (MUA) and 1-decanethiol (DCT) for potential applications to drug release, protective coatings, and immunosensors. We aimed to develop a highly sensitive and reliable method to quantify the mass of various modified AuNPs. The surface of AuNPs and Au electrode was coated with polymer films, as determined by Fourier transform infrared spectroscopy and atomic force microscopy. Measurements obtained for various AuNPs and the plasma-treated surface of the Au electrode were compared with those obtained for an untreated Au electrode. According to the resonant frequency shift of QCM, a linear relationship was observed that significantly differed for AuNPs, MUA-AuNPs, and DCT-AuNPs (R2 range, 0.94-0.965, 0.934-0.972, and 0.874-0.9514, respectively). Compared to inductively coupled plasma and micro-computerized tomography, the QCM method with plasma treatment has advantages of real-time monitoring, greater sensitivity, and lower cost. Our results demonstrate that surface modifications measured by a QCM system for various modified AuNPs were reliable.

A sensitive electrochemical immunosensor based on poly(2-aminobenzylamine) film modified screen-printed carbon electrode for label-free detection of human immunoglobulin G.

PubMed

Putnin, Thitirat; Jumpathong, Watthanachai; Laocharoensuk, Rawiwan; Jakmunee, Jaroon; Ounnunkad, Kontad

2018-08-01

This work focuses on fabricating poly(2-aminobenzylamine)-modified screen-printed carbon electrode as an electrochemical immunosensor for the label-free detection of human immunoglobulin G. To selectively detect immunoglobulin G, the anti-immunoglobulin G antibody with high affinity to immunoglobulin G was covalently linked with the amine group of poly(2-aminobenzylamine) film-deposited screen-printed carbon electrode. The selectivity for immunoglobulin G was subsequently assured by being challenged with redox-active interferences and adventitious adsorption did not significantly interfere the analyte signal. To obviate the use of costly secondary antibody, the [Fe(CN) 6 ] 4-/3- redox probe was instead applied to measure the number of human immunoglobulin G through the immunocomplex formation that is quantitatively related to the level of the differential pulse voltammetric current. The resulting immunosensor exhibited good sensitivity with the detection limit of 0.15 ng mL -1 , limit of quantitation of 0.50 ng mL -1 and the linear range from 1.0 to 50 ng mL -1 . Given those striking analytical performances and the affordability arising from using cheap screen-printed carbon electrode with label-free detection, the immunosensor serves as a promising model for the next-step development of a diagnostic tool.

AC electric field for rapid assembly of nanostructured polyaniline onto microsized gap for sensor devices.

PubMed

La Ferrara, Vera; Rametta, Gabriella; De Maria, Antonella

2015-07-01

Interconnected network of nanostructured polyaniline (PANI) is giving strong potential for enhancing device performances than bulk PANI counterparts. For nanostructured device processing, the main challenge is to get prototypes on large area by requiring precision, low cost and high rate assembly. Among processes meeting these requests, the alternate current electric fields are often used for nanostructure assembling. For the first time, we show the assembly of nanostructured PANI onto large electrode gaps (30-60 μm width) by applying alternate current electric fields, at low frequencies, to PANI particles dispersed in acetonitrile (ACN). An important advantage is the short assembly time, limited to 5-10 s, although electrode gaps are microsized. That encouraging result is due to a combination of forces, such as dielectrophoresis (DEP), induced-charge electrokinetic (ICEK) flow and alternate current electroosmotic (ACEO) flow, which speed up the assembly process when low frequencies and large electrode gaps are used. The main achievement of the present study is the development of ammonia sensors created by direct assembling of nanostructured PANI onto electrodes. Sensors exhibit high sensitivity to low gas concentrations as well as excellent reversibility at room temperature, even after storage in air. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Sensitive, selective, disposable electrochemical dopamine sensor based on PEDOT-modified laser scribed graphene.

PubMed

Xu, Guangyuan; Jarjes, Zahraa A; Desprez, Valentin; Kilmartin, Paul A; Travas-Sejdic, Jadranka

2018-06-01

The fabrication of a novel, and highly selective electrochemical sensor based on a poly(3,4-ethylenedioxythiophene) (PEDOT) modified laser scribed graphene (LSG), and detection of dopamine (DA) in the presence of ascorbic acid (AA) and uric acid (UA) is described. LSG electrodes were produced with a 3-dimensional macro-porous network and large electrochemically-active surface area via direct laser writing on polyimide sheets. PEDOT was electrodeposited on the LSG electrode, and the physical properties of the obtained films were characterized by scanning electron microscopy (SEM) and energy dispersive X-ray diffraction microanalysis (EDAX). The modified electrodes were applied for the determination of DA in the presence of AA and UA using cyclic voltammetry (CV), and differential pulse voltammetry (DPV) techniques. The linear range for dopamine detection was found to be 1-150 µM with a sensitivity of 0.220 ± 0.011 µA μM -1 and a detection limit of 0.33 µM; superior values to those obtained without PEDOT. For the first time, PEDOT-modified LSG have been fabricated and assessed for high-performance dopamine sensing using cost-effective, disposable electrodes, with potential for development in further sensing applications. Copyright © 2018 Elsevier B.V. All rights reserved.

Gold nanoparticles/4-aminothiophenol interfaces for direct electron transfer of horseradish peroxidase: Enzymatic orientation and modulation of sensitivity towards hydrogen peroxide detection.

PubMed

Huerta-Miranda, G A; Arrocha-Arcos, A A; Miranda-Hernández, M

2018-08-01

Hydrogen peroxide electrochemical detection by horseradish peroxidase has been widely studied. The use of gold nanoparticles to prepare electrode/enzyme bioconjugates has attracted attention due to their catalytic properties. In this work, it is reported the use of gold nanoparticles and 4-aminothiophenol as a scaffold to obtain a suitable matrix for enzyme bioconjugation with horseradish peroxidase. A critical factor in biosensors design and development is the enzymatic electrochemical activity understanding. Comparison of voltammetric studies of the heme prosthetic group showed a reversible electrochemical behavior when the enzymes were immobilized in a well-dispersed gold deposit; on the other hand, a discrete redox response was observed on a randomly deposited gold electrode. These results show that the distance between enzymes is essential. Hydrogen peroxide catalysis and the enzymatic behavior were analyzed considering two types of nanoparticles dispositions. The catalytic behavior observed in the well-dispersed nanoparticles configuration suggests a preserved enzyme folding, a decrease of steric impediments, and appears to be a better immobilization strategy. In contrast, the randomly electrodeposited gold electrode decreased the enzyme orientation and the electrochemical activity. The advantages of this methodology are the electrode fabrication affordable cost and the enzymatic direct electron transfer response improvement. Copyright © 2018 Elsevier B.V. All rights reserved.

Superwetting and aptamer functionalized shrink-induced high surface area electrochemical sensors.

PubMed

Hauke, A; Kumar, L S Selva; Kim, M Y; Pegan, J; Khine, M; Li, H; Plaxco, K W; Heikenfeld, J

2017-08-15

Electrochemical sensing is moving to the forefront of point-of-care and wearable molecular sensing technologies due to the ability to miniaturize the required equipment, a critical advantage over optical methods in this field. Electrochemical sensors that employ roughness to increase their microscopic surface area offer a strategy to combatting the loss in signal associated with the loss of macroscopic surface area upon miniaturization. A simple, low-cost method of creating such roughness has emerged with the development of shrink-induced high surface area electrodes. Building on this approach, we demonstrate here a greater than 12-fold enhancement in electrochemically active surface area over conventional electrodes of equivalent on-chip footprint areas. This two-fold improvement on previous performance is obtained via the creation of a superwetting surface condition facilitated by a dissolvable polymer coating. As a test bed to illustrate the utility of this approach, we further show that electrochemical aptamer-based sensors exhibit exceptional signal strength (signal-to-noise) and excellent signal gain (relative change in signal upon target binding) when deployed on these shrink electrodes. Indeed, the observed 330% gain we observe for a kanamycin sensor is 2-fold greater than that seen on planar gold electrodes. Copyright © 2017 Elsevier B.V. All rights reserved.

Radiofrequency Lesions through Deep Brain Stimulation Electrodes in Movement Disorders: Case Report and Review of the Literature.

PubMed

Pérez-Suárez, Javier; Torres Díaz, Cristina V; López Manzanares, Lydia; Navas García, Marta; Pastor, Jesús; Barrio Fernández, Patricia; G de Sola, Rafael

2017-01-01

Although there are few reports of radiofrequency lesions performed through deep brain stimulation (DBS) electrodes in patients with movement disorders, experience with this method is scarce. We present 2 patients who had been previously treated with DBS of subthalamic nuclei (STN) and the ventral intermediate (VIM) nucleus of the thalamus for Parkinson's disease and essential tremor, respectively, and underwent a radiofrequency lesion through their DBS electrodes after developing a hardware infection. The authors conduct a review of the literature regarding this method. Both patients had a good clinical outcome after 20 and 8 months, respectively, as assessed by a reduction in Fahn-Tolosa-Marin Scale and Unified Parkinson's Disease Rating Scale scores. The second patient underwent a second DBS system implantation surgery after his radiofrequency treatment to optimize his management, achieving optimal clinical control with lower current and drug requirements than before the radiofrequency intervention. No adverse effects were observed. Radiofrequency lesions through DBS electrodes allow the creation of small and localized lesions. Its effectiveness and low-risk profile, in addition to its low cost, make this procedure suitable and a possible alternative in the therapeutic repertoire for the surgical treatment of movement disorders. © 2017 S. Karger AG, Basel.

Electrode/workpiece combinations

NASA Astrophysics Data System (ADS)

Benedict, J. J.

1989-10-01

Of the many machine tool operations available in the shop today, plunge cut Electrical Discharge Machining (EDM) has become an increasingly useful method of materials fabrication. It is a necessary tool for the research and development type of work performed at the Lawrence Livermore National Laboratory (LLNL). With advancing technology, plunge cut EDMs are more efficient, faster, have greater accuracy and are able to produce better surface finishes. They have been in the past and will continue to be an important part of the production of quality parts in both the Precision and NC Shop. It should be kept in mind that as a non-traditional machining process, EDMing is a time consuming process that can be a very expensive method of producing parts. For this reason, it must be used in the most efficient manner in order to make it a cost-effective means of fabrication, although technology has advanced to the point of state-of-the-art equipment, there is currently a void in available technical information needed for use with this process. The type of information sought after concerns the area of electrode/workpiece combinations. This is in reference to the task of choosing the correct electrode material for the specific workpiece material encountered. A brief description of the EDM process will help in understanding the electrode/workpiece relationship.

Hierarchical Cobalt Hydroxide and B/N Co-Doped Graphene Nanohybrids Derived from Metal-Organic Frameworks for High Energy Density Asymmetric Supercapacitors

PubMed Central

Tabassum, Hassina; Mahmood, Asif; Wang, Qingfei; Xia, Wei; Liang, Zibin; Qiu, Bin; zhao, Ruo; Zou, Ruqiang

2017-01-01

To cater for the demands of electrochemical energy storage system, the development of cost effective, durable and highly efficient electrode materials is desired. Here, a novel electrode material based on redox active β-Co(OH)2 and B, N co-doped graphene nanohybrid is presented for electrochemical supercapacitor by employing a facile metal-organic frameworks (MOFs) route through pyrolysis and hydrothermal treatment. The Co(OH)2 could be firmly stabilized by dual protection of N-doped carbon polyhedron (CP) and B/N co-doped graphene (BCN) nanosheets. Interestingly, the porous carbon and BCN nanosheets greatly improve the charge storage, wettability, and redox activity of electrodes. Thus the hybrid delivers specific capacitance of 1263 F g−1 at a current density of 1A g−1 with 90% capacitance retention over 5000 cycles. Furthermore, the new aqueous asymmetric supercapacitor (ASC) was also designed by using Co(OH)2@CP@BCN nanohybrid and BCN nanosheets as positive and negative electrodes respectively, which leads to high energy density of 20.25 Whkg−1. This device also exhibits excellent rate capability with energy density of 15.55 Whkg−1 at power density of 9331 Wkg−1 coupled long termed stability up to 6000 cycles. PMID:28240224

Hierarchical Cobalt Hydroxide and B/N Co-Doped Graphene Nanohybrids Derived from Metal-Organic Frameworks for High Energy Density Asymmetric Supercapacitors.

PubMed

Tabassum, Hassina; Mahmood, Asif; Wang, Qingfei; Xia, Wei; Liang, Zibin; Qiu, Bin; Zhao, Ruo; Zou, Ruqiang

2017-02-27

To cater for the demands of electrochemical energy storage system, the development of cost effective, durable and highly efficient electrode materials is desired. Here, a novel electrode material based on redox active β-Co(OH) 2 and B, N co-doped graphene nanohybrid is presented for electrochemical supercapacitor by employing a facile metal-organic frameworks (MOFs) route through pyrolysis and hydrothermal treatment. The Co(OH) 2 could be firmly stabilized by dual protection of N-doped carbon polyhedron (CP) and B/N co-doped graphene (BCN) nanosheets. Interestingly, the porous carbon and BCN nanosheets greatly improve the charge storage, wettability, and redox activity of electrodes. Thus the hybrid delivers specific capacitance of 1263 F g -1 at a current density of 1A g -1 with 90% capacitance retention over 5000 cycles. Furthermore, the new aqueous asymmetric supercapacitor (ASC) was also designed by using Co(OH) 2 @CP@BCN nanohybrid and BCN nanosheets as positive and negative electrodes respectively, which leads to high energy density of 20.25 Whkg -1 . This device also exhibits excellent rate capability with energy density of 15.55 Whkg -1 at power density of 9331 Wkg -1 coupled long termed stability up to 6000 cycles.

Ruthenium oxide ion selective thin-film electrodes for engine oil acidity monitoring

NASA Astrophysics Data System (ADS)

Maurya, D. K.; Sardarinejad, A.; Alameh, K.

2015-06-01

We demonstrate the concept of a low-cost, rugged, miniaturized ion selective electrode (ISE) comprising a thin film RuO2 on platinum sensing electrode deposited using RF magnetron sputtered in conjunction with an integrated Ag/AgCl and Ag reference electrodes for engine oil acidity monitoring. Model oil samples are produced by adding nitric acid into fresh fully synthetic engine oil and used for sensor evaluation. Experimental results show a linear potential-versus-acid-concentration response for nitric acid concentration between 0 (fresh oil) to 400 ppm, which demonstrate the accuracy of the RuO2 sensor in real-time operation, making it attractive for use in cars and industrial engines.

Intelligent Medical Garments with Graphene-Functionalized Smart-Cloth ECG Sensors.

PubMed

Yapici, Murat Kaya; Alkhidir, Tamador Elboshra

2017-04-16

Biopotential signals are recorded mostly by using sticky, pre-gelled electrodes, which are not ideal for wearable, point-of-care monitoring where the usability of the personalized medical device depends critically on the level of comfort and wearability of the electrodes. We report a fully-wearable medical garment for mobile monitoring of cardiac biopotentials from the wrists or the neck with minimum restriction to regular clothing habits. The wearable prototype is based on elastic bands with graphene functionalized, textile electrodes and battery-powered, low-cost electronics for signal acquisition and wireless transmission. Comparison of the electrocardiogram (ECG) recordings obtained from the wearable prototype against conventional wet electrodes indicate excellent conformity and spectral coherence among the two signals.

Electrolytic photodissociation of chemical compounds by iron oxide electrodes

DOEpatents

Somorjai, Gabor A.; Leygraf, Christofer H.

1984-01-01

Chemical compounds can be dissociated by contacting the same with a p/n type semi-conductor diode having visible light as its sole source of energy. The diode consists of low cost, readily available materials, specifically polycrystalline iron oxide doped with silicon in the case of the n-type semi-conductor electrode, and polycrystalline iron oxide doped with magnesium in the case of the p-type electrode. So long as the light source has an energy greater than 2.2 electron volts, no added energy source is needed to achieve dissociation.

Novel nanoarchitectures for electrochemical biosensing

NASA Astrophysics Data System (ADS)

Archibald, Michelle M.

Sensitive, real-time detection of biomarkers is of critical importance for rapid and accurate diagnosis of disease for point-of-care (POC) technologies. Current methods, while sensitive, do not adequately allow for POC applications due to several limitations, including complex instrumentation, high reagent consumption, and cost. We have investigated two novel nanoarchitectures, the nanocoax and the nanodendrite, as electrochemical biosensors towards the POC detection of infectious disease biomarkers to overcome these limitations. The nanocoax architecture is composed of vertically-oriented, nanoscale coaxial electrodes, with coax cores and shields serving as integrated working and counter electrodes, respectively. The dendritic structure consists of metallic nanocrystals extending from the working electrode, increasing sensor surface area. Nanocoaxial- and nanodendritic-based electrochemical sensors were fabricated and developed for the detection of bacterial toxins using an electrochemical enzyme-linked immunosorbent assay (ELISA) and differential pulse voltammetry (DPV). Proof-of-concept was demonstrated for the detection of cholera toxin (CT). Both nanoarchitectures exhibited levels of sensitivity that are comparable to the standard optical ELISA used widely in clinical applications. In addition to matching the detection profile of the standard ELISA, these electrochemical nanosensors provide a simple electrochemical readout and a miniaturized platform with multiplexing capabilities toward POC implementation. Further development as suggested in this thesis may lead to increases in sensitivity, enhancing the attractiveness of the architectures for future POC devices.

LiNi 0.8 Co 0.2 O 2 -based high power lithium-ion battery positive electrodes analyzed by x-ray photoelectron spectroscopy: 1. Fresh electrode

DOE Office of Scientific and Technical Information (OSTI.GOV)

Haasch, Richard T.; Abraham, Daniel A.

2016-12-01

High-power lithium-ion batteries are rapidly replacing the nickel metal hydride batteries currently used for energy storage in hybrid electric vehicles. Widespread commercialization of these batteries for vehicular applications is, however, limited by calendar-life performance, thermal abuse characteristics, and cost. The Advanced Technology Development Program was established by the U.S. Department of Energy to address these limitations. An important objective of this program was the development and application of diagnostic tools that provide unique ways to investigate the phenomena that limit lithium-ion cell life, performance, and safety characteristics. This report introduces a set of six Surface Science Spectra xray photoelectron spectroscopymore » (XPS) comparison records of data collected from positive electrodes (cathode) harvested from cylindrically wound, 18650-type, 1 A h capacity cells. The cathodes included in this study are (1) fresh, (2) following three formation cycles, (3) following calendar-life test for 12 weeks at 40 C, 60% state-of-charge (SOC), (4) following calendar-life test for 8 weeks at 50 C, 60% SOC, (5) following calendar-life test for 8 weeks at 60 C, 60% SOC, and (6) following calendar-life test for 2 weeks at 70 C, 60% SOC.« less

Rapid and label-free electrochemical DNA biosensor for detecting hepatitis A virus.

PubMed

Manzano, Marisa; Viezzi, Sara; Mazerat, Sandra; Marks, Robert S; Vidic, Jasmina

2018-02-15

Diagnostic systems that can deliver highly specific and sensitive detection of hepatitis A virus (HAV) in food and water are of particular interest in many fields including food safety, biosecurity and control of outbreaks. Our aim was the development of an electrochemical method based on DNA hybridization to detect HAV. A ssDNA probe specific for HAV (capture probe) was designed and tested on DNAs from various viral and bacterial samples using Nested-Reverse Transcription Polymerase Chain Reaction (nRT-PCR). To develop the electrochemical device, a disposable gold electrode was functionalized with the specific capture probe and tested on complementary ssDNA and on HAV cDNA. The DNA hybridization on the electrode was measured through the monitoring of the oxidative peak potential of the indicator tripropylamine by cyclic voltammetry. To prevent non-specific binding the gold surface was treated with 3% BSA before detection. High resolution atomic force microscopy (AFM) confirmed the efficiency of electrode functionalization and on-electrode hybridization. The proposed device showed a limit of detection of 0.65pM for the complementary ssDNA and 6.94fg/µL for viral cDNA. For a comparison, nRT-PCR quantified the target HAV cDNA with a limit of detection of 6.4fg/µL. The DNA-sensor developed can be adapted to a portable format to be adopted as an easy-to- use and low cost method for screening HAV in contaminated food and water. In addition, it can be useful for rapid control of HAV infections as it takes only a few minutes to provide the results. Copyright © 2017. Published by Elsevier B.V.

Plasma-Based Synthesis of Nanostructured Materials and their Characterization

NASA Astrophysics Data System (ADS)

Chaudhary, Rakesh P.

The aim of this thesis is to explore the novel cost-effective synthesis technique to develop nanostructured materials and investigate their structural and magnetic properties. Nanomaterials were synthesized by a plasma discharge between desired metal electrodes in the cavitation field of an organic solvent. Multifunctional core-shell magnetic nanoparticles of 3d transition elements (Fe, Ni) and bimetallic (FeNi) were synthesized by varying experimental conditions. The phase, crystallinity and the magnetic properties of the materials synthesized were found to be dependent on experimental reaction parameters such as different solvents, electrodes, the spacing between electrodes, applied voltage, experiment time and high-temperature annealing. Fe and Gd-based nanoparticles were developed for high-performance magnetic resonance imaging (MRI) contrast enhancement. Biocompatible hybrid composite of Fe core - C shell nanoparticles evaluated as negative MRI contrast agents display remarkably high transverse relaxivity (r2) of 70 mM-1S-1 at 7T. In addition to 3d transition magnetic materials, magnetism of multilayer graphene nanosheets with only s and p electrons was investigated to understand and explain the intrinsic origin of ferromagnetism in carbon-based material. Apart from magnetic materials, noble metal Pd nanoparticles were developed using one-step process for hydrogen storage. The role of hydrogen on the dilation of Pd lattice was investigated using the experiment and density functional theory (DFT) studies. This method demonstrates that plasma discharge method using appropriate electrodes and solvents can be used to synthesize desired nanoparticles. This potential emphasizes the importance of adopting this methodology, which offers advantages that include a rapid reaction rate and ability to form very small nanoparticles with narrow size distribution.

Efficiency enhancement using voltage biasing for ferroelectric polarization in dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Kim, Sangmo; Song, Myoung Geun; Bark, Chung Wung

2018-01-01

Dye-sensitized solar cells (DSSCs) are one of the most promising third generation solar cells that have been extensively researched over the past decade as alternative to silicon-based solar cells, due to their low production cost and high energy-conversion efficiency. In general, a DSSC consists of a transparent electrode, a counter electrode, and an electrolyte such as dye. To achieve high power-conversion efficiency in cells, many research groups have focused their efforts on developing efficient dyes for liquid electrolytes. In this work, we report on the photovoltaic properties of DSSCs fabricated using a mixture of TiO2 with nanosized Fe-doped bismuth lanthanum titanate (nFe-BLT) powder). Firstly, nFe-BLT powders were prepared using a high-energy ball milling process and then, TiO2 and nFe-BLT powders were stoichiometrically blended. Direct current (DC) bias of 20 MV/m was applied to lab-made DSSCs. With the optimal concentration of nFe-BLT doped in the electrode, their light-to-electricity conversion efficiency could be improved by ∼64% compared with DSSCs where no DC bias was applied.

Bacterial-cellulose-derived interconnected meso-microporous carbon nanofiber networks as binder-free electrodes for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Hao, Xiaodong; Wang, Jie; Ding, Bing; Wang, Ya; Chang, Zhi; Dou, Hui; Zhang, Xiaogang

2017-06-01

Bacterial cellulose (BC), a typical biomass prepared from the microbial fermentation process, has been proved that it can be an ideal platform for design of three-dimensional (3D) multifunctional nanomaterials in energy storage and conversion field. Here we developed a simple and general silica-assisted strategy for fabrication of interconnected 3D meso-microporous carbon nanofiber networks by confine nanospace pyrolysis of sustainable BC, which can be used as binder-free electrodes for high-performance supercapacitors. The synthesized carbon nanofibers exhibited the features of interconnected 3D networks architecture, large surface area (624 m2 g-1), mesopores-dominated hierarchical porosity, and high graphitization degree. The as-prepared electrode (CN-BC) displayed a maximum specific capacitance of 302 F g-1 at a current density of 0.5 A g-1, high-rate capability and good cyclicity in 6 M KOH electrolyte. This work, together with cost-effective preparation strategy to make high-value utilization of cheap biomass, should have significant implications in the green and mass-producible energy storage.

Insertion compounds and composites made by ball milling for advanced sodium-ion batteries

PubMed Central

Zhang, Biao; Dugas, Romain; Rousse, Gwenaelle; Rozier, Patrick; Abakumov, Artem M.; Tarascon, Jean-Marie

2016-01-01

Sodium-ion batteries have been considered as potential candidates for stationary energy storage because of the low cost and wide availability of Na sources. However, their future commercialization depends critically on control over the solid electrolyte interface formation, as well as the degree of sodiation at the positive electrode. Here we report an easily scalable ball milling approach, which relies on the use of metallic sodium, to prepare a variety of sodium-based alloys, insertion layered oxides and polyanionic compounds having sodium in excess such as the Na4V2(PO4)2F3 phase. The practical benefits of preparing sodium-enriched positive electrodes as reservoirs to compensate for sodium loss during solid electrolyte interphase formation are demonstrated by assembling full C/P′2-Na1[Fe0.5Mn0.5]O2 and C/‘Na3+xV2(PO4)2F3' sodium-ion cells that show substantial increases (>10%) in energy storage density. Our findings may offer electrode design principles for accelerating the development of the sodium-ion technology. PMID:26777573

Calcium-selective electrodes based on photo-cured polyurethane-acrylate membranes covalently attached to methacrylate functionalized poly(3,4-ethylenedioxythiophene) as solid-contact.

PubMed

Ocaña, Cristina; Abramova, Natalia; Bratov, Andrey; Lindfors, Tom; Bobacka, Johan

2018-08-15

We report here the fabrication of solid-contact calcium-selective electrodes (Ca 2+ -SCISEs) made of a polyurethane acrylate ion-selective membrane (ISM) that was covalently attached to the underlying ion-to-electron transducer (solid-contact). Methacrylate-functionalized poly(3,4-ethylenedioxythiophene) (Meth-PEDOT) and Meth-PEDOT films containing either multiwalled carbon nanotubes (MWCNT) or carboxylated MWCNT (cMWCNT) were used as solid contacts. The solid contacts were deposited by drop-casting on screen-printed electrodes and characterized by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and potentiometry. Covalent binding between the solid contact and the ISM was obtained via photopolymerization in order to increase the robustness of the Ca 2+ -SCISEs. The performance of the Ca 2+ -SCISEs was studied by measuring their potentiometric response and their sensitivity to light, oxygen and carbon dioxide. Meth-PEDOT was found to be a promising solid-contact material to develop low-cost and easy to prepare ISEs. Copyright © 2018 Elsevier B.V. All rights reserved.

Lipoxygenase-modified Ru-bpy/graphene oxide: Electrochemical biosensor for on-farm monitoring of non-esterified fatty acid.

PubMed

Veerapandian, Murugan; Hunter, Robert; Neethirajan, Suresh

2016-04-15

Elevated concentrations of non-esterified fatty acids (NEFA) in biological fluids are recognized as critical biomarkers for early diagnosis of dairy cow metabolic diseases. Herein, a cost-effective, electrochemically active, and bio-friendly sensor element based on ruthenium bipyridyl complex-modified graphene oxide nanosheets ([Ru(bpy)3](2+)-GO) is proposed as a biosensor platform for NEFA detection. Electrochemical analysis demonstrates that the [Ru(bpy)3](2+)-GO electrodes exhibit superior and durable redox properties compared to the pristine carbon and GO electrodes. Target specificity is accomplished through immobilization of the enzyme, lipoxygenase, which catalyzes the production of redox active species from NEFA. Lipoxygenases retain their catalytic ability upon immobilization and exhibit changes to amperometric signals upon interaction with various concentrations of standard NEFA and serum samples. Our study demonstrates that the [Ru(bpy)3](2+)-GO electrode has the potential to serve as a biosensor platform for developing a field deployable, rapid, and user-friendly detection tool for on-farm monitoring of dairy cow metabolic diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Shi, J.; Xue, X.

A comprehensive 3D CFD model is developed for a bi-electrode supported cell (BSC) SOFC. The model includes complicated transport phenomena of mass/heat transfer, charge (electron and ion) migration, and electrochemical reaction. The uniqueness of the modeling study is that functionally graded porous electrode property is taken into account, including not only linear but nonlinear porosity distributions. Extensive numerical analysis is performed to elucidate the effects of both porous microstructure distributions and operating condition on cell performance. Results indicate that cell performance is strongly dependent on both operating conditions and porous microstructure distributions of electrodes. Using the proposed fuel/gas feeding design,more » the uniform hydrogen distribution within porous anode is achieved; the oxygen distribution within the cathode is dependent on porous microstructure distributions as well as pressure loss conditions. Simulation results show that fairly uniform temperature distribution can be obtained with the proposed fuel/gas feeding design. The modeling results can be employed to guide experimental design of BSC test and provide pre-experimental analysis, as a result, to circumvent high cost associated with try-and-error experimental design and setup.« less

Improved low-cost, non-hazardous, all-iron cell for the developing world

NASA Astrophysics Data System (ADS)

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed; Williams, Benjamin; Wang, Wu-Chieh Jerry; Weber, Adam Z.

2016-11-01

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade after a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm-2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. We anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.

A novel paper-based device coupled with a silver nanoparticle-modified boron-doped diamond electrode for cholesterol detection.

PubMed

Nantaphol, Siriwan; Chailapakul, Orawon; Siangproh, Weena

2015-09-03

A novel paper-based analytical device (PAD) coupled with a silver nanoparticle-modified boron-doped diamond (AgNP/BDD) electrode was first developed as a cholesterol sensor. The AgNP/BDD electrode was used as working electrode after modification by AgNPs using an electrodeposition method. Wax printing was used to define the hydrophilic and hydrophobic areas on filter paper, and then counter and reference electrodes were fabricated on the hydrophilic area by screen-printing in house. For the amperometric detection, cholesterol and cholesterol oxidase (ChOx) were directly drop-cast onto the hydrophilic area, and H2O2 produced from the enzymatic reaction was monitored. The fabricated device demonstrated a good linearity (0.39 mg dL(-1) to 270.69 mg dL(-1)), low detection limit (0.25 mg dL(-1)), and high sensitivity (49.61 μA mM(-1) cm(-2)). The precision value for ten replicates was 3.76% RSD for 1 mM H2O2. In addition, this biosensor exhibited very high selectivity for cholesterol detection and excellent recoveries for bovine serum analysis (in the range of 99.6-100.8%). The results showed that this new sensing platform will be an alternative tool for cholesterol detection in routine diagnosis and offers the advantages of low sample/reagent consumption, low cost, portability, and short analysis time. Copyright © 2015 Elsevier B.V. All rights reserved.

A microfabricated low cost enzyme-free glucose fuel cell for powering low-power implantable devices

NASA Astrophysics Data System (ADS)

Oncescu, Vlad; Erickson, David

In the past decade the scientific community has showed considerable interest in the development of implantable medical devices such as muscle stimulators, neuroprosthetic devices, and biosensors. Those devices have low power requirements and can potentially be operated through fuel cells using reactants present in the body such as glucose and oxygen instead of non-rechargeable lithium batteries. In this paper, we present a thin, enzyme-free fuel cell with high current density and good stability at a current density of 10 μA cm -2. A non-enzymatic approach is preferred because of higher long term stability. The fuel cell uses a stacked electrode design in order to achieve glucose and oxygen separation. An important characteristic of the fuel cell is that it has no membrane separating the electrodes, which results in low ohmic losses and small fuel cell volume. In addition, it uses a porous carbon paper support for the anodic catalyst layer which reduces the amount of platinum or other noble metal catalysts required for fabricating high surface area electrodes with good reactivity. The peak power output of the fuel cell is approximately 2 μW cm -2 and has a sustainable power density of 1.5 μW cm -2 at 10 μA cm -2. An analysis on the effects of electrode thickness and inter electrode gap on the maximum power output of the fuel cell is also performed.

The characterisation and design improvement of a paper-based E.coli impedimetric sensor

NASA Astrophysics Data System (ADS)

Bezuidenhout, P.; Kumar, S.; Wiederoder, M.; Schoeman, J.; Land, K.; Joubert, T.-H.

2016-02-01

This paper describes the development and optimisation of a paper-based E. coli impedimetric biosensor for water quality monitoring. Impedimetric biosensing is advantageous because it is a highly sensitive, label-free, real-time method for the detection of biological species. An impedimetric biosensor measures the change in impedance caused by specific capture of a target on the sensor surface. Each biosensor consists of a pair of photo paper-based inkjet printed electrodes. An impedance analyser was used to measure the impedance at frequencies ranging from 1 kHz to 1 MHz at 1V. The parameters that were investigated to achieve enhanced sensor performance were buffer type, antibody attachment method, measurement frequency, electrode layout, and conductive material. A 0.04M PBS (phosphate buffered saline) solution achieves better results compared to a less conductive 0.04M PB (potassium phosphate dibasic) solution. The direct adsorption of anti-E. coli antibodies onto the sensor surface yielded better results than attaching the sensor to a lateral flow test. The resistive component had a greater impact on the detected impedance, therefore an optimal frequency of 1 MHz was identified. Geometrical electrode designs that maximise the resistive change between the electrodes were utilised. Both lower cost silver and bio-compatible gold ink were validated as electrode materials. The impedance change generated by the selective capture of E. coli K-12, ranging in concentration from 103 to 107 colony forming units per millilitre (cfu/ml), showed a detection limit of 105 cfu/ml.

Profiling mild steel welding processes to reduce fume emissions and costs in the workplace.

PubMed

Keane, Michael J; Siert, Arlen; Chen, Bean T; Stone, Samuel G

2014-05-01

To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g(-1) electrode) and lowest for GMAW processes such as pulsed spray (~1.5mg g(-1)) and CMT (~1mg g(-1)). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g(-1) (SMAW) to 0.08 mg g(-1) (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g(-1) (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g(-1) (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides information to aid in those choices. Suggestions for overcoming barriers to utilizing new and less hazardous welding processes are also discussed.

Profiling Mild Steel Welding Processes to Reduce Fume Emissions and Costs in the Workplace

PubMed Central

Keane, Michael J.; Siert, Arlen; Chen, Bean T.; Stone, Samuel G.

2015-01-01

To provide quantitative information to choose the best welding processes for minimizing workplace emissions, nine gas metal arc welding (GMAW) processes for mild steel were assessed for fume generation rates, normalized fume generation rates (milligram fume per gram of electrode consumed), and normalized generation rates for elemental manganese, nickel, and iron. Shielded metal arc welding (SMAW) and flux-cored arc-welding (FCAW) processes were also profiled. The fumes were collected quantitatively in an American Welding Society-type fume chamber and weighed, recovered, homogenized, and analyzed by inductively coupled atomic emission spectroscopy for total metals. The processes included GMAW with short circuit, globular transfer, axial spray, pulsed spray, Surface Tension Transfer™, Regulated Metal Deposition™, and Cold Metal Transfer™ (CMT) modes. Flux-cored welding was gas shielded, and SMAW was a single rod type. Results indicate a wide range of fume emission factors for the process variations studied. Fume emission rates per gram of electrode consumed were highest for SMAW (~13 mg fume g−1 electrode) and lowest for GMAW processes such as pulsed spray (~1.5 mg g−1) and CMT (~1 mg g−1). Manganese emission rates per gram of electrode consumed ranged from 0.45 mg g−1 (SMAW) to 0.08 mg g−1 (CMT). Nickel emission rates were generally low and ranged from ~0.09 (GMAW short circuit) to 0.004 mg g−1 (CMT). Iron emission rates ranged from 3.7 (spray-mode GMAW) to 0.49 mg g−1 (CMT). The processes studied have significantly different costs, and cost factors are presented based on a case study to allow comparisons between processes in specific cost categories. Costs per linear meter of weld were $31.07 (SMAW), $12.37 (GMAW short circuit), and $10.89 (FCAW). Although no single process is the best for minimizing fume emissions and costs while satisfying the weld requirements, there are several processes that can minimize emissions. This study provides information to aid in those choices. Suggestions for overcoming barriers to utilizing new and less hazardous welding processes are also discussed. PMID:24515891

High Performance, Low Cost Hydrogen Generation from Renewable Energy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ayers, Katherine; Dalton, Luke; Roemer, Andy

Renewable hydrogen from proton exchange membrane (PEM) electrolysis is gaining strong interest in Europe, especially in Germany where wind penetration is already at critical levels for grid stability. For this application as well as biogas conversion and vehicle fueling, megawatt (MW) scale electrolysis is required. Proton has established a technology roadmap to achieve the necessary cost reductions and manufacturing scale up to maintain U.S. competitiveness in these markets. This project represents a highly successful example of the potential for cost reduction in PEM electrolysis, and provides the initial stack design and manufacturing development for Proton’s MW scale product launch. Themore » majority of the program focused on the bipolar assembly, from electrochemical modeling to subscale stack development through prototyping and manufacturing qualification for a large active area cell platform. Feasibility for an advanced membrane electrode assembly (MEA) with 50% reduction in catalyst loading was also demonstrated. Based on the progress in this program and other parallel efforts, H2A analysis shows the status of PEM electrolysis technology dropping below $3.50/kg production costs, exceeding the 2015 target.« less

Advanced Catalysts for Fuel Cells

NASA Technical Reports Server (NTRS)

Narayanan, Sekharipuram R.; Whitacre, Jay; Valdez, T. I.

2006-01-01

This viewgraph presentation reviews the development of catalyst for Fuel Cells. The objectives of the project are to reduce the cost of stack components and reduce the amount of precious metal used in fuel cell construction. A rapid combinatorial screening technique based on multi-electrode thin film array has been developed and validated for identifying catalysts for oxygen reduction; focus shifted from methanol oxidation in FY05 to oxygen reduction in FY06. Multi-electrode arrays of thin film catalysts of Pt-Ni and Pt-Ni-Zr have been deposited. Pt-Ni and have been characterized electrochemically and structurally. Pt-Ni-Zr and Pt-Ni films show higher current density and onset potential compared to Pt. Electrocatalytic activity and onset potential are found to be strong function of the lattice constant. Thin film Pt(59)Ni(39)Zr(2) can provide 10 times the current density of thin film Pt. Thin film Pt(59)Ni(39)Zr(2) also shows 65mV higher onset potential than Pt.

Nanomolar detection of methylparaben by a cost-effective hemoglobin-based biosensor.

PubMed

Hajian, A; Ghodsi, J; Afraz, A; Yurchenko, O; Urban, G

2016-12-01

This work describes the development of a new biosensor for methylparaben determination using electrocatalytic properties of hemoglobin in the presence of hydrogen peroxide. The voltammetric oxidation of methylparaben by the proposed biosensor in phosphate buffer (pH=7.0), a physiological pH, was studied and it was confirmed that methylparaben undergoes a one electron-one proton reaction in a diffusion-controlled process. The biosensor was fabricated by carbon paste electrode modified with hemoglobin and multiwalled carbon nanotube. Based on the excellent electrochemical properties of the modified electrode, a sensitive voltammetric method was used for determination of methylparaben within a linear range from 0.1 to 13μmolL(-1) and detection limit of 25nmolL(-1). The developed biosensor possessed accurate and rapid response to methylparaben and showed good sensitivity, stability, and repeatability. Finally, the applicability of the proposed biosensor was verified by methylparaben evaluation in various real samples. Copyright © 2016 Elsevier B.V. All rights reserved.

Pseudocapacitive Sodium Storage by Ferroelectric Sn2 P2 S6 with Layered Nanostructure.

PubMed

Huang, Sheng; Meng, Chao; Xiao, Min; Ren, Shan; Wang, Shuanjin; Han, Dongmei; Li, Yuning; Meng, Yuezhong

2018-04-19

Sodium ion batteries (SIB) are considered promising alternative candidates for lithium ion batteries (LIB) because of the wide availability and low cost of sodium, therefore the development of alternative sodium storage materials with comparable performance to LIB is urgently desired. The sodium ions with larger sizes resist intercalation or alloying because of slow reaction kinetics. Most pseudocapacitive sodium storage materials are based on subtle nanomaterial engineering, which is difficult for large-scale production. Here, ferroelectric Sn 2 P 2 S 6 with layered nanostructure is developed as sodium ion storage material. The ferroelectricity-enhanced pseudocapacitance of sodium ion in the interlayer spacing makes the electrochemical reaction easier and faster, endowing the Sn 2 P 2 S 6 electrode with excellent rate capability and cycle stability. Furthermore, the facile solid state reaction synthesis and common electrode fabrication make the Sn 2 P 2 S 6 that becomes a promising anode material of SIB. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Macroscale porous carbonized polydopamine-modified cotton textile for application as electrode in microbial fuel cells

NASA Astrophysics Data System (ADS)

Zeng, Lizhen; Zhao, Shaofei; He, Miao

2018-02-01

The anode material is a crucial factor that significantly affects the cost and performance of microbial fuel cells (MFCs). In this study, a novel macroscale porous, biocompatible, highly conductive and low cost electrode, carbonized polydopamine-modified cotton textile (NC@CCT), is fabricated by using normal cheap waste cotton textiles as raw material via a simple in situ polymerization and carbonization treatment as anode of MFCs. The physical and chemical characterizations show that the macroscale porous and biocompatible NC@CCT electrode is coated by nitrogen-doped carbon nanoparticles and offers a large specific surface area (888.67 m2 g-1) for bacterial cells growth, accordingly greatly increases the loading amount of bacterial cells and facilitates extracellular electron transfer (EET). As a result, the MFC equipped with the NC@CCT anode achieves a maximum power density of 931 ± 61 mW m-2, which is 80.5% higher than that of commercial carbon felt (516 ± 27 mW m-2) anode. Moreover, making full use of the normal cheap waste cotton textiles can greatly reduce the cost of MFCs and the environmental pollution problem.

Zeolite-based Impedimetric Gas Sensor Device in Low-cost Technology for Hydrocarbon Gas Detection

PubMed Central

Reiß, Sebastian; Hagen, Gunter; Moos, Ralf

2008-01-01

Due to increasing environmental concerns the need for inexpensive selective gas sensors is increasing. This work deals with transferring a novel zeolite-based impedimetric hydrocarbon gas sensor principle, which has been originally manufactured in a costly combination of photolithography, thin-film processes, and thick-film processes to a low-cost technology comprising only thick-film processes and one electroplating step. The sensing effect is based on a thin chromium oxide layer between the interdigital electrodes and a Pt-loaded ZSM-5 zeolite film. When hydrocarbons are present in the sensor ambient, the electrical sensor impedance increases strongly and selectively. In the present work, the chromium oxide film is electroplated on Au screen-printed interdigital electrodes and then oxidized to Cr2O3. The electrode area is covered with the screen-printed zeolite. The sensor device is self-heated utilizing a planar platinum heater on the backside. The best sensor performance is obtained at a frequency of 3 Hz at around 350 °C. The good selectivity of the original sensor setup could be confirmed, but a strong cross-sensitivity to ammonia occurs, which might prohibit its original intention for use in automotive exhausts. PMID:27873966

Flame oxidation of stainless steel felt enhances anodic biofilm formation and current output in bioelectrochemical systems.

PubMed

Guo, Kun; Donose, Bogdan C; Soeriyadi, Alexander H; Prévoteau, Antonin; Patil, Sunil A; Freguia, Stefano; Gooding, J Justin; Rabaey, Korneel

2014-06-17

Stainless steel (SS) can be an attractive material to create large electrodes for microbial bioelectrochemical systems (BESs), due to its low cost and high conductivity. However, poor biocompatibility limits its successful application today. Here we report a simple and effective method to make SS electrodes biocompatible by means of flame oxidation. Physicochemical characterization of electrode surface indicated that iron oxide nanoparticles (IONPs) were generated in situ on an SS felt surface by flame oxidation. IONPs-coating dramatically enhanced the biocompatibility of SS felt and consequently resulted in a robust electroactive biofilm formation at its surface in BESs. The maximum current densities reached at IONPs-coated SS felt electrodes were 16.5 times and 4.8 times higher than the untreated SS felts and carbon felts, respectively. Furthermore, the maximum current density achieved with the IONPs-coated SS felt (1.92 mA/cm(2), 27.42 mA/cm(3)) is one of the highest current densities reported thus far. These results demonstrate for the first time that flame oxidized SS felts could be a good alternative to carbon-based electrodes for achieving high current densities in BESs. Most importantly, high conductivity, excellent mechanical strength, strong chemical stability, large specific surface area, and comparatively low cost of flame oxidized SS felts offer exciting opportunities for scaling-up of the anodes for BESs.

Hierarchical porous carbon aerogel derived from bagasse for high performance supercapacitor electrode.

PubMed

Hao, Pin; Zhao, Zhenhuan; Tian, Jian; Li, Haidong; Sang, Yuanhua; Yu, Guangwei; Cai, Huaqiang; Liu, Hong; Wong, C P; Umar, Ahmad

2014-10-21

Renewable, cost-effective and eco-friendly electrode materials have attracted much attention in the energy conversion and storage fields. Bagasse, the waste product from sugarcane that mainly contains cellulose derivatives, can be a promising candidate to manufacture supercapacitor electrode materials. This study demonstrates the fabrication and characterization of highly porous carbon aerogels by using bagasse as a raw material. Macro and mesoporous carbon was first prepared by carbonizing the freeze-dried bagasse aerogel; consequently, microporous structure was created on the walls of the mesoporous carbon by chemical activation. Interestingly, it was observed that the specific surface area, the pore size and distribution of the hierarchical porous carbon were affected by the activation temperature. In order to evaluate the ability of the hierarchical porous carbon towards the supercapacitor electrode performance, solid state symmetric supercapacitors were assembled, and a comparable high specific capacitance of 142.1 F g(-1) at a discharge current density of 0.5 A g(-1) was demonstrated. The fabricated solid state supercapacitor displayed excellent capacitance retention of 93.9% over 5000 cycles. The high energy storage ability of the hierarchical porous carbon was attributed to the specially designed pore structures, i.e., co-existence of the micropores and mesopores. This research has demonstrated that utilization of sustainable biopolymers as the raw materials for high performance supercapacitor electrode materials is an effective way to fabricate low-cost energy storage devices.

Study and Fabrication of Super Low-Cost Solar Cell (SLC-SC) Based on Counter Electrode from Animal’s Bone

NASA Astrophysics Data System (ADS)

Fadlilah, D. R.; Fajar, M. N.; Aini, A. N.; Haqqiqi, R. I.; Wirawan, P. R.; Endarko

2018-04-01

The synthesized carbon from bones of chicken, cow, and fish with the calcination temperature at 450 and 600°C have been successfully fabricated for counter electrode in the Super Low-Cost Solar Cell (SLC-LC) based the structure of Dye-Sensitized Solar Cells (DSSC). The main proposed study was to fabricate SLC-SC and investigate the influence of the synthesized carbon from animal’s bone for counter electrode towards to photovoltaic performance of SLC-SC. X-Ray Diffraction and UV-Vis was used to characterize the phase and the optical properties of TiO2 as photoanode in SLC-SC. Meanwhile, the morphology and particle size distribution of the synthesized carbon in counter electrodes were investigated by Scanning Electron Microscopy (SEM) and Particle Size Analyzer (PSA). The results showed that the TiO2 has anatase phase with the absorption wavelength of 300 to 550 nm. The calcination temperature for synthesizing of carbon could affect morphology and particle size distribution. The increasing temperature gave the effect more dense in morphology and increased the particle size of carbon in the counter electrode. Changes in morphology and particle size of carbon give effect to the performance of the SLC-SC where the increased morphology’s compact and particle size make decreased in the performance of the SLC-SC.

Negative electrodes for Na-ion batteries.

PubMed

Dahbi, Mouad; Yabuuchi, Naoaki; Kubota, Kei; Tokiwa, Kazuyasu; Komaba, Shinichi

2014-08-07

Research interest in Na-ion batteries has increased rapidly because of the environmental friendliness of sodium compared to lithium. Throughout this Perspective paper, we report and review recent scientific advances in the field of negative electrode materials used for Na-ion batteries. This paper sheds light on negative electrode materials for Na-ion batteries: carbonaceous materials, oxides/phosphates (as sodium insertion materials), sodium alloy/compounds and so on. These electrode materials have different reaction mechanisms for electrochemical sodiation/desodiation processes. Moreover, not only sodiation-active materials but also binders, current collectors, electrolytes and electrode/electrolyte interphase and its stabilization are essential for long cycle life Na-ion batteries. This paper also addresses the prospect of Na-ion batteries as low-cost and long-life batteries with relatively high-energy density as their potential competitive edge over the commercialized Li-ion batteries.

Flexible polypyrrole/copper sulfide/bacterial cellulose nanofibrous composite membranes as supercapacitor electrodes.

PubMed

Peng, Shuo; Fan, Lingling; Wei, Chengzhuo; Liu, Xiaohong; Zhang, Hongwei; Xu, Weilin; Xu, Jie

2017-02-10

Polypyrrole (PPy) and copper sulfide (CuS) have been successfully deposited on bacterial cellulose (BC) membranes to prepare nanofibrous composite electrodes of PPy/CuS/BC for flexible supercapacitor applications. The introduction of CuS remarkably improves the specific capacitance and cycling stability of BC-based electrodes. The specific capacitance of the supercapacitors based on the PPy/CuS/BC electrodes can reach to about 580Fg -1 at a current density of 0.8mAcm -2 and can retain about 73% of their initial value after 300 cycles, while the PPy/BC-based device could retain only 21.7% after 300 cycles. This work provides a promising approach to fabricate cost-effective and flexible nanofibrous composite membranes for high-performance supercapacitor electrodes. Copyright © 2016 Elsevier Ltd. All rights reserved.

Offset-electrode profile acquisition strategy for electrical resistivity tomography

NASA Astrophysics Data System (ADS)

Robbins, Austin R.; Plattner, Alain

2018-04-01

We present an electrode layout strategy that allows electrical resistivity profiles to image the third dimension close to the profile plane. This "offset-electrode profile" approach involves laterally displacing electrodes away from the profile line in an alternating fashion and then inverting the resulting data using three-dimensional electrical resistivity tomography software. In our synthetic and field surveys, the offset-electrode method succeeds in revealing three-dimensional structures in the vicinity of the profile plane, which we could not achieve using three-dimensional inversions of linear profiles. We confirm and explain the limits of linear electrode profiles through a discussion of the three-dimensional sensitivity patterns: For a homogeneous starting model together with a linear electrode layout, all sensitivities remain symmetric with respect to the profile plane through each inversion step. This limitation can be overcome with offset-electrode layouts by breaking the symmetry pattern among the sensitivities. Thanks to freely available powerful three-dimensional resistivity tomography software and cheap modern computing power, the requirement for full three-dimensional calculations does not create a significant burden and renders the offset-electrode approach a cost-effective method. By offsetting the electrodes in an alternating pattern, as opposed to laying the profile out in a U-shape, we minimize shortening the profile length.

Double-plasma enhanced carbon shield for spatial/interfacial controlled electrodes in lithium ion batteries via micro-sized silicon from wafer waste

NASA Astrophysics Data System (ADS)

Chen, Bing-Hong; Chuang, Shang-I.; Duh, Jenq-Gong

2016-11-01

Using spatial and interfacial control, the micro-sized silicon waste from wafer slurry could greatly increase its retention potential as a green resource for silicon-based anode in lithium ion batteries. Through step by step spatial and interfacial control for electrode, the cyclability of recycled waste gains potential performance from its original poor retention property. In the stages of spatial control, the electrode stabilizers of active, inactive and conductive additives were mixed into slurries for maintaining architecture and conductivity of electrode. In addition, a fusion electrode modification of interfacial control combines electrolyte additive, technique of double-plasma enhanced carbon shield (D-PECS) to convert the chemical bond states and to alter the formation of solid electrolyte interphases (SEIs) in the first cycle. The depth profiles of chemical composition from external into internal electrode illustrate that the fusion electrode modification not only forms a boundary to balance the interface between internal and external electrodes but also stabilizes the SEIs formation and soothe the expansion of micro-sized electrode. Through these effect approaches, the performance of micro-sized Si waste electrode can be boosted from its serious capacity degradation to potential retention (200 cycles, 1100 mAh/g) and better meet the requirements for facile and cost-effective in industrial production.

Agricultural Residues and Other Carbon-Based Resources as Feedstocks for Supercapacitor Electrodes

NASA Astrophysics Data System (ADS)

Wang, Yong

Agricultural residues are generally considered as renewable, economical and environmental-friendly sources to produce carbon-based nanomaterials with many advanced applications. Agricultural residues and by-products generated from the agricultural industry, such as distiller's dried grains with solubles (DDGS), are produced every year on a large scale but lack of proper utilization. As a result, seeking high-value applications based on agricultural residues is essential for the promotion of the economy in agricultural producing states like North Dakota, USA. With the fast development of nanotechnology in recent years, carbon-based nanomaterials have attracted intense research interests in the fields of chemistry, materials science and condensed matter physics due to many unique properties (e.g., chemical and thermal stability, electrical conductivity, mechanical strength, etc.). The development of low-cost nanomaterials using agricultural residues as feedstocks can be a promising route for the sustainable development of the agricultural industry. In this dissertation, the preparation of carbon-based materials from agricultural residues is explored. Many advanced applications are investigated, especially in the field of energy storage devices. The development of porous activate carbons were investigated in detail, and their application as electrode materials of supercapacitors was demonstrated. Hydrothermal carbonization of biomass to produce carbonaceous materials was also covered in this dissertation. In addition to traditional raw materials such as cellulose produced from wood industry, novel material sources such as bacterial cellulose were used to prepare nanocomposites that can be used for the electrodes of supercapacitors. This dissertation contributes to the sustainable development of the agricultural industry in North Dakota.

Invasive Electrical Impedance Tomography for Blood Vessel Detection

PubMed Central

Martinsen, Ørjan G.; Kalvøy, Håvard; Grimnes, Sverre; Nordbotten, Bernt; Hol, Per Kristian; Fosse, Erik; Myklebust, Helge; Becker, Lance B

2010-01-01

We present a novel method for localization of large blood vessels using a bioimpedance based needle positioning system on an array of ten monopolar needle electrodes. The purpose of the study is to develop a portable, low cost tool for rapid vascular access for cooling and controlled reperfusion of cardiac arrest patients. Preliminary results show that localization of blood vessels is feasible with this method, but larger studies are necessary to improve the technology. PMID:21611140

Cellular Structure Fabricated on Ni Wire by a Simple and Cost-Effective Direct-Flame Approach and Its Application in Fiber-Shaped Supercapacitors.

PubMed

Wang, Zhihong; Cao, Fenhui; Chen, Kongfa; Yan, Yingming; Chen, Yifu; Zhang, Yaohui; Zhu, Xingbao; Wei, Bo; Xiong, Yueping; Lv, Zhe

2018-03-09

Cellular metals with the large surface/volume ratios and excellent electrical conductivity are widely applicable and have thus been studied extensively. It is highly desirable to develop a facile and cost-effective process for fabrication of porous metallic structures, and yet more so for micro/nanoporous structures. A direct-flame strategy is developed for in situ fabrication of micron-scale cellular architecture on a Ni metal precursor. The flame provides the required heat and also serves as a fuel reformer, which provides a gas mixture of H 2 , CO, and O 2 for redox treatment of metallic Ni. The redox processes at elevated temperatures allow fast reconstruction of the metal, leading to a cellular structure on Ni wire. This process is simple and clean and avoids the use of sacrificial materials or templates. Furthermore, nanocrystalline MnO 2 is coated on the microporous Ni wire (MPNW) to form a supercapacitor electrode. The MnO 2 /MPNW electrode and the corresponding fiber-shaped supercapacitor exhibit high specific capacitance and excellent cycling stability. Moreover, this work provides a novel strategy for the fabrication of cellular metals and alloys for a variety of applications, including catalysis, energy storage and conversion, and chemical sensing. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

A handy liquid metal based electroosmotic flow pump.

PubMed

Gao, Meng; Gui, Lin

2014-06-07

A room temperature liquid metal based electroosmotic flow (EOF) pump has been proposed in this work. This low-cost EOF pump is convenient for both fabrication and integration. It utilizes polydimethylsiloxane (PDMS) microchannels filled with the liquid-metal as non-contact pump electrodes. The electrode channels are fabricated symmetrically to both sides of the pumping channel, having no contact with the pumping channel. To test the pumping performance of the EOF pump, the mean flow velocities of the fluid (DI water) in the EOF pumps were experimentally measured by tracing the fluorescent microparticles in the flow. To provide guidance for designing a low voltage EOF pump, parametric studies on dimensions of the electrode and pumping channels were performed in this work. According to the experimental results, the pumping speed can reach 5.93 μm s(-1) at a driving voltage of only 1.6 V, when the gap between the electrode and the pumping channel is 20 μm. Injecting a room temperature liquid metal into microchannels can provide a simple, rapid, low-cost but accurately self-aligned way to fabricate microelectrodes for EOF pumps, which is a promising method to achieve the miniaturization and integration of the EOF pump in microfluidic systems. The non-contact liquid electrodes have no influence on the fluid in the pumping channel when pumping, reducing Joule heat generation and preventing gas bubble formation at the surface of electrodes. The pump has great potential to drive a wide range of fluids, such as drug reagents, cell suspensions and biological macromolecule solutions.

All-Nonvacuum-Processed CIGS Solar Cells Using Scalable Ag NWs/AZO-Based Transparent Electrodes.

PubMed

Wang, Mingqing; Choy, Kwang-Leong

2016-07-06

With record cell efficiency of 21.7%, CIGS solar cells have demonstrated to be a very promising photovoltaic (PV) technology. However, their market penetration has been limited due to the inherent high cost of the cells. In this work, to lower the cost of CIGS solar cells, all nonvacuum-processed CIGS solar cells were designed and developed. CIGS absorber was prepared by the annealing of electrodeposited metallic layers in a chalcogen atmosphere. Nonvacuum-deposited Ag nanowires (NWs)/AZO transparent electrodes (TEs) with good transmittance (92.0% at 550 nm) and high conductivity (sheet resistance of 20 Ω/□) were used to replace the vacuum-sputtered window layer. Additional thermal treatment after device preparation was conducted at 220 °C for a few of minutes to improve both the value and the uniformity of the efficiency of CIGS pixel cell on 5 × 5 cm substrate. The best performance of the all-nonvacuum-fabricated CIGS solar cells showed an efficiency of 14.05% with Jsc of 34.82 mA/cm(2), Voc of 0.58 V, and FF of 69.60%, respectively, which is comparable with the efficiency of 14.45% of a reference cell using a sputtered window layer.

Solution-processed highly conductive PEDOT:PSS/AgNW/GO transparent film for efficient organic-Si hybrid solar cells.

PubMed

Xu, Qiaojing; Song, Tao; Cui, Wei; Liu, Yuqiang; Xu, Weidong; Lee, Shuit-Tong; Sun, Baoquan

2015-02-11

Hybrid solar cells based on n-Si/poly(3,4-ethylenedioxythiophene):poly(styrene- sulfonate) (PEDOT:PSS) heterojunction promise to be a low cost photovoltaic technology by using simple device structure and easy fabrication process. However, due to the low conductivity of PEDOT:PSS, a metal grid deposited by vacuum evaporation method is still required to enhance the charge collection efficiency, which complicates the device fabrication process. Here, a solution-processed graphene oxide (GO)-welded silver nanowires (AgNWs) transparent conductive electrode (TCE) was employed to replace the vacuum deposited metal grid. A unique "sandwich" structure was developed by embedding an AgNW network between PEDOT:PSS and GO with a figure-of-merit of 8.6×10(-3) Ω(-1), which was even higher than that of sputtered indium tin oxide electrode (6.6×10(-3) Ω(-1)). A champion power conversion efficiency of 13.3% was achieved, because of the decreased series resistance of the TCEs as well as the enhanced built-in potential (Vbi) in the hybrid solar cells. The TCEs were obtained by facile low-temperature solution process method, which was compatible with cost-effective mass production technology.

Development of Carbon Based optically Transparent Electrodes from Pyrolyzed Photoresist for the Investigation of Phenomena at Electrified Carbon-Solution Interfaces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Donner, Sebastian

2007-01-01

The work presented herein describes a fundamental investigations of carbon as electrode material by using the pyrolysis of photoresist to create an optically transparent material. The development of these carbon-based optically transparent electrodes (C-OTEs) enables investigations of molecular interactions within the electrical double layer, processes that are central to a wide range of important phenomena, including the impact of changes in the surface charge density on adsorption. The electrochemical importance of carbon cannot be understated, having relevance to separations and detection by providing a wide potential window and low background current in addition to being low cost and light weight.more » The interactions that govern the processes at the carbon electrode surface has been studied extensively. A variety of publications from the laboratories of McCreery and Kinoshita provide in depth summaries about carbon and its many applications in electrochemistry. These studies reveal that defects, impurities, oxidation, and a variety of functional groups create adsorption sites on carbon surfaces with different characteristics. The interest in C-OTEs was sparked by the desire to study and understand the behavior of individual molecules at electrified interfaces. It draws on the earlier development of Electrochemically Modulated Liquid Chromatography (EMLC), which uses carbon as the stationary phase. EMLC takes advantage of changing the applied potential to the carbon electrode to influence the retention behavior of analytes. However, perspectives gained from, for example, chromatographic measurements reflect the integrated response of a large ensemble of potentially diverse interactions between the adsorbates and the carbon electrode. Considering the chemically and physically heterogeneous surface of electrode materials such as glassy carbon, the integrated response provides little insight into the interactions at a single molecule level. To investigate individual processes, they have developed C-OTEs in order to couple electrochemistry with single molecule spectroscopy (SMS). Like EMLC, the novel merger of SMS with electrochemistry is a prime example of how a hybrid method can open new and intriguing avenues that are of both fundamental and technological importance. They show that by taking the benefits of total internal reflection fluorescence microscopy (TIRFM) and incorporating carbon as electrode material observations central to the interactions between single DNA molecules and an electrified carbon surface can be delineated. Using TIRFM while applying a positive potential to the electrode, individual molecules can be observed as they reversibly and irreversibly adsorb to the carbon surface. The positive potential attracts the negatively charged DNA molecules to the electrode surface. Dye labels on the DNA within the evanescent wave are excited and their fluorescence is captured by an intensified charge coupled device (ICCD) camera. Results are therefore presented regarding the interactions of λ-DNA, 48,502 base pairs (48.5 kbp), HPV-16, 7.9 kbp, and 1 kbp fraction of pBR322 DNA. In addition to the influence of molecular size on adsorption, the fabrication, characterization, and more conventional spectroelectrochemical applications of these novel C-OTEs are presented.« less

A Comparison of the Effects of Electrode Implantation and Targeting on Pattern Classification Accuracy for Prosthesis Control

PubMed Central

Farrell, Todd R.; Weir, Richard F. ff.

2011-01-01

The use of surface versus intramuscular electrodes as well as the effect of electrode targeting on pattern-recognition-based multifunctional prosthesis control was explored. Surface electrodes are touted for their ability to record activity from relatively large portions of muscle tissue. Intramuscular electromyograms (EMGs) can provide focal recordings from deep muscles of the forearm and independent signals relatively free of crosstalk. However, little work has been done to compare the two. Additionally, while previous investigations have either targeted electrodes to specific muscles or used untargeted (symmetric) electrode arrays, no work has compared these approaches to determine if one is superior. The classification accuracies of pattern-recognition-based classifiers utilizing surface and intramuscular as well as targeted and untargeted electrodes were compared across 11 subjects. A repeated-measures analysis of variance revealed that when only EMG amplitude information was used from all available EMG channels, the targeted surface, targeted intramuscular, and untargeted surface electrodes produced similar classification accuracies while the untargeted intramuscular electrodes produced significantly lower accuracies. However, no statistical differences were observed between any of the electrode conditions when additional features were extracted from the EMG signal. It was concluded that the choice of electrode should be driven by clinical factors, such as signal robustness/stability, cost, etc., instead of by classification accuracy. PMID:18713689

Paper-based maskless enzymatic sensor for glucose determination combining ink and wire electrodes.

PubMed

Amor-Gutiérrez, O; Costa Rama, E; Costa-García, A; Fernández-Abedul, M T

2017-07-15

In this work we have developed an amperometric enzymatic biosensor in a paper-based platform with a mixed electrode configuration: carbon ink for the working electrode (WE) and metal wires (from a low-cost standard electronic connection) for reference (RE) and auxiliary electrodes (AE). A hydrophobic wax-defined paper area was impregnated with diluted carbon ink. Three gold-plated pins of the standard connection are employed, one for connecting the WE and the other two acting as RE and AE. The standard connection works as a clip in order to support the paper in between. As a proof-of-concept, glucose sensing was evaluated. The enzyme cocktail (glucose oxidase, horseradish peroxidase and potassium ferrocyanide as mediator of the electron transfer) was adsorbed on the surface. After drying, glucose solution was added to the paper, on the opposite side of the carbon ink. It wets RE and AE, and flows by capillarity through the paper contacting the carbon WE surface. The reduction current of ferricyanide, product of the enzymatic reaction, is measured chronoamperometrically and correlates to the concentration of glucose. Different parameters related to the bioassay were optimized, adhering the piece of paper onto a conventional screen-printed carbon electrode (SPCE). In this way, the RE and the AE of the commercial card were employed for optimizing the paper-WE. After evaluating the assay system in the hybrid paper-SPCE cell, the three-electrode system consisting of paper-WE, wire-RE and wire-AE, was employed for glucose determination, achieving a linear range between 0.3 and 15mM with good analytical features and being able of quantifying glucose in real food samples. Copyright © 2016 Elsevier B.V. All rights reserved.

A new architecture as transparent electrodes for solar and IR applications based on photonic structures via soft lithography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kuang, Ping

2011-01-01

Transparent conducting electrodes with the combination of high optical transmission and good electrical conductivity are essential for solar energy harvesting and electric lighting devices. Currently, indium tin oxide (ITO) is used because ITO offers relatively high transparency (>80%) to visible light and low sheet resistance (R s = 10 ohms/square (Ω /2)) for electrical conduction. However, ITO is costly due to limited indium reserves, and it is brittle. These disadvantages have motivated the search for other conducting electrodes with similar or better properties. There has been research on a variety of electrode structures involving carbon nanotube networks, graphene films, nanowiremore » and nanopatterned meshes and grids. Due to their novel characteristics in light manipulation and collection, photonic crystal structures show promise for further improvement. Here, we report on a new architecture consisting of nanoscale high aspect ratio metallic photonic structures as transparent electrodes fabricated via a combination of processes. For (Au) and silver (Ag) structures, the visible light transmission can reach as high as 80%, and the sheet resistance of the structure can be as low as 3.2Ω /2. The optical transparency of the high aspect ratio metal structures at visible wavelength range is comparable to that of ITO glass, while their sheet resistance is more than 3 times lower, which indicates a much higher electrical conductivity of the metal structures. Furthermore, the high aspect ratio metal structures have very high infrared (IR) reflection (90%) for the transverse magnetic (TM) mode, which can lead to the development of fabrication of metallic structures as IR filters for heat control applications. Investigations of interdigitated structures based on the high aspect ratio metal electrodes are ongoing to study the feasibility in smart window applications in light transmission modulation.« less

Optimizing Discharge Capacity of Li-O 2 Batteries by Design of Air-Electrode Porous Structure: Multifidelity Modeling and Optimization

DOE PAGES

Pan, Wenxiao; Yang, Xiu; Bao, Jie; ...

2017-01-01

We develop a new mathematical framework to study the optimal design of air electrode microstructures for lithium-oxygen (Li-O2) batteries. It can eectively reduce the number of expensive experiments for testing dierent air-electrodes, thereby minimizing the cost in the design of Li-O2 batteries. The design parameters to characterize an air-electrode microstructure include the porosity, surface-to-volume ratio, and parameters associated with the pore-size distribution. A surrogate model (also known as response surface) for discharge capacity is rst constructed as a function of these design parameters. The surrogate model is accurate and easy to evaluate such that an optimization can be performed basedmore » on it. In particular, a Gaussian process regression method, co-kriging, is employed due to its accuracy and eciency in predicting high-dimensional responses from a combination of multidelity data. Specically, a small amount of data from high-delity simulations are combined with a large number of data obtained from computationally ecient low-delity simulations. The high-delity simulation is based on a multiscale modeling approach that couples the microscale (pore-scale) and macroscale (device-scale) models. Whereas, the low-delity simulation is based on an empirical macroscale model. The constructed response surface provides quantitative understanding and prediction about how air electrode microstructures aect the discharge performance of Li-O2 batteries. The succeeding sensitivity analysis via Sobol indices and optimization via genetic algorithm ultimately oer a reliable guidance on the optimal design of air electrode microstructures. The proposed mathematical framework can be generalized to investigate other new energy storage techniques and materials.« less

Optimizing Discharge Capacity of Li-O 2 Batteries by Design of Air-Electrode Porous Structure: Multifidelity Modeling and Optimization

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pan, Wenxiao; Yang, Xiu; Bao, Jie

We develop a new mathematical framework to study the optimal design of air electrode microstructures for lithium-oxygen (Li-O2) batteries. It can eectively reduce the number of expensive experiments for testing dierent air-electrodes, thereby minimizing the cost in the design of Li-O2 batteries. The design parameters to characterize an air-electrode microstructure include the porosity, surface-to-volume ratio, and parameters associated with the pore-size distribution. A surrogate model (also known as response surface) for discharge capacity is rst constructed as a function of these design parameters. The surrogate model is accurate and easy to evaluate such that an optimization can be performed basedmore » on it. In particular, a Gaussian process regression method, co-kriging, is employed due to its accuracy and eciency in predicting high-dimensional responses from a combination of multidelity data. Specically, a small amount of data from high-delity simulations are combined with a large number of data obtained from computationally ecient low-delity simulations. The high-delity simulation is based on a multiscale modeling approach that couples the microscale (pore-scale) and macroscale (device-scale) models. Whereas, the low-delity simulation is based on an empirical macroscale model. The constructed response surface provides quantitative understanding and prediction about how air electrode microstructures aect the discharge performance of Li-O2 batteries. The succeeding sensitivity analysis via Sobol indices and optimization via genetic algorithm ultimately oer a reliable guidance on the optimal design of air electrode microstructures. The proposed mathematical framework can be generalized to investigate other new energy storage techniques and materials.« less

Post-treatment of molasses wastewater by electrocoagulation and process optimization through response surface analysis.

PubMed

Tsioptsias, C; Petridis, D; Athanasakis, N; Lemonidis, I; Deligiannis, A; Samaras, P

2015-12-01

Molasses wastewater is a high strength effluent of food industry such as distilleries, sugar and yeast production plants etc. It is characterized by a dark brown color and exhibits a high content in substances of recalcitrant nature such as melanoidins. In this study, electrocoagulation (EC) was studied as a post treatment step for biologically treated molasses wastewater with high nitrogen content obtained from a baker's yeast industry. Iron and copper electrodes were used in various forms; the influence and interaction of current density, molasses wastewater dilution, and reaction time, on COD, color, ammonium and nitrate removal rates and operating cost were studied and optimized through Box Behnken's response surface analysis. Reaction time varied from 0.5 to 4 h, current density varied from 5 to 40 mA/cm(2) and dilution from 0 to 90% (v/v expressed as water concentration). pH, conductivity and temperature measurements were also carried out during each experiment. From preliminary experiments, it was concluded that the application of aeration and sample dilution, considerably influenced the kinetics of the process. The obtained results showed that COD removal varied between 10 and 54%, corresponding to an operation cost ranging from 0.2 to 33 euro/kg COD removed. Significant removal rates were obtained for nitrogen as nitrate and ammonium (i.e. 70% ammonium removal). A linear relation of COD and ammonium to the design parameters was observed, while operation cost and nitrate removal responded in a curvilinear function. A low ratio of electrode surface to treated volume was used, associated to a low investment cost; in addition, iron wastes could be utilized as low cost electrodes i.e. iron fillings from lathes, aiming to a low operation cost due to electrodes replacement. In general, electrocoagulation proved to be an effective and low cost process for biologically treated molasses-wastewater treatment for additional removal of COD and nitrogen content and color reduction. Treated effluent samples with good quality were produced by EC, with COD, NH4-N and NO3-N concentrations of 180, 52 and 2 mg/l respectively. Response surface analysis revealed that optimized conditions could be established under moderate molasses wastewater dilution, (e.g. 45%), at 3.5 h treatment time and 33 mA/cm(2) current density. Copyright © 2015 Elsevier Ltd. All rights reserved.

Calcium-bismuth electrodes for large-scale energy storage (liquid metal batteries)

NASA Astrophysics Data System (ADS)

Kim, Hojong; Boysen, Dane A.; Ouchi, Takanari; Sadoway, Donald R.

2013-11-01

Calcium is an attractive electrode material for use in grid-scale electrochemical energy storage due to its low electronegativity, earth abundance, and low cost. The feasibility of combining a liquid Ca-Bi positive electrode with a molten salt electrolyte for use in liquid metal batteries at 500-700 °C was investigated. Exhibiting excellent reversibility up to current densities of 200 mA cm-2, the calcium-bismuth liquid alloy system is a promising positive electrode candidate for liquid metal batteries. The measurement of low self-discharge current suggests that the solubility of calcium metal in molten salt electrolytes can be sufficiently suppressed to yield high coulombic efficiencies >98%. The mechanisms giving rise to Ca-Bi electrode overpotentials were investigated in terms of associated charge transfer and mass transport resistances. The formation of low density Ca11Bi10 intermetallics at the electrode-electrolyte interface limited the calcium deposition rate capability of the electrodes; however, the co-deposition of barium into bismuth from barium-containing molten salts suppressed Ca-Bi intermetallic formation thereby improving the discharge capacity.

Three-phase double-arc plasma for spectrochemical analysis of environmental samples.

PubMed

Mohamed, M M; Ghatass, Z F; Shalaby, E A; Kotb, M M; El-Raey, M

2000-12-01

A new instrument, which uses a three-phase current to support a double-arc argon plasma torch for evaporation, atomization and excitation of solid or powder samples, is described. The sampling arc is ignited between the first and second electrode while the excitation arc is ignited between the second and third electrode. Aerosol generated from the sample (first electrode) is swept by argon gas, through a hole in the second electrode (carbon tubing electrode), into the excitation plasma. A tangential stream of argon gas is introduced through an inlet orifice as a coolant gas for the second electrode. This gas stream forces the excitation arc discharge to rotate reproducibly around the electrode surface. Discharge rotation increases the stability of the excitation plasma. Spectroscopic measurements are made directly in the current-carrying region of the excitation arc. An evaluation of each parameter influencing the device performance was performed. Analytical calibration curves were obtained for Fe, Al, K, and Pb. Finally, the present technique was applied for the analysis of environmental samples. The present method appears to have significant, low cost analytical utility for environmental measurements.

Poly(3,4-ethylenedioxythiophene)/reduced graphene oxide composites as counter electrodes for high efficiency dye-sensitized solar cells

NASA Astrophysics Data System (ADS)

Ma, Jinfu; Yuan, Shenghua; Yang, Shaolin; Lu, Hui; Li, Yingtao

2018-05-01

A facile, low cost, easy-controllable method to prepare Poly(3,4-ethylenedioxythiophene) (PEDOT)/reduced graphene oxide (rGO) composites by electrochemical deposition onto fluorinated tin oxide (FTO) as counter electrodes (CEs) in high performance dye-sensitized solar cells (DSSCs) is reported. The electro-deposition process was accomplished by electro-polymerization of graphene oxide (GO)/PEDOT composites onto FTO substrates followed by electrochemical reduction of the GO component. Electrochemical measurements show that the I-/I3- catalytic activity of the as-prepared PEDOT/rGO CE is improved compared with that of the pure PEDOT and PEDOT/GO electrode. Through the analysis of photoelectric properties, the performance of the electrodes fabricated with different polymerization times are compared, and the optimal preparation condition is determined. The photoelectric conversion efficiency (PCE) of the DSSC assembled with PEDOT/rGO electrode reaches 7.79%, close to 8.33% of the cell with Platinum (Pt) electrode, and increases by 13.2% compared with 6.88% of the device with the PEDOT electrode.

Paper electrodes for bioelectrochemistry: Biosensors and biofuel cells.

PubMed

Desmet, Cloé; Marquette, Christophe A; Blum, Loïc J; Doumèche, Bastien

2016-02-15

Paper-based analytical devices (PAD) emerge in the scientific community since 2007 as low-cost, wearable and disposable devices for point-of-care diagnostic due to the widespread availability, long-time knowledge and easy manufacturing of cellulose. Rapidly, electrodes were introduced in PAD for electrochemical measurements. Together with biological components, a new generation of electrochemical biosensors was born. This review aims to take an inventory of existing electrochemical paper-based biosensors and biofuel cells and to identify, at the light of newly acquired data, suitable methodologies and crucial parameters in this field. Paper selection, electrode material, hydrophobization of cellulose, dedicated electrochemical devices and electrode configuration in biosensors and biofuel cells will be discussed. Copyright © 2015 Elsevier B.V. All rights reserved.

Intelligent Medical Garments with Graphene-Functionalized Smart-Cloth ECG Sensors

PubMed Central

Yapici, Murat Kaya; Alkhidir, Tamador Elboshra

2017-01-01

Biopotential signals are recorded mostly by using sticky, pre-gelled electrodes, which are not ideal for wearable, point-of-care monitoring where the usability of the personalized medical device depends critically on the level of comfort and wearability of the electrodes. We report a fully-wearable medical garment for mobile monitoring of cardiac biopotentials from the wrists or the neck with minimum restriction to regular clothing habits. The wearable prototype is based on elastic bands with graphene functionalized, textile electrodes and battery-powered, low-cost electronics for signal acquisition and wireless transmission. Comparison of the electrocardiogram (ECG) recordings obtained from the wearable prototype against conventional wet electrodes indicate excellent conformity and spectral coherence among the two signals. PMID:28420158

Platinum Group Metal Recycling Technology Development - Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lawrence Shore

BASF Catalysts LLC, formerly Engelhard Corporation, has completed a project to recover Pt from PEM fuel cell membrane electrode assemblies. The project, which began in 2003, has met the project objective of an environmentally-friendly, cost-effective method for recovery of platinum without release of hydrogen fluoride. This has been achieved using a combination of milling, dispersion and acid leaching. 99% recovery of Pt was achieved, and this high yield can be scaled up using one vessel for a single leach and rinse. Leaching was been successfully achieved using a 10% solids level, double the original target. At this solids content, themore » reagent and utility costs represent ~0.35% of the Pt value of a lot, using very conservative assumptions. The main cost of the process is capital depreciation, followed by labor.« less

The development of a multichannel electrode array for retinal prostheses.

PubMed

Terasawa, Yasuo; Tashiro, Hiroyuki; Uehara, Akihiro; Saitoh, Tohru; Ozawa, Motoki; Tokuda, Takashi; Ohta, Jun

2006-01-01

The development of a multielectrode array is the key issue for retinal prostheses. We developed a 10 x 10 platinum electrode array that consists of an 8-microm polyimide layer sandwiched between 5-microm polymonochloro-para-xylylene (parylene-C) layers. Each electrode was formed as a 30-microm-high bump by Pt/Au double-layer electroplating. We estimated the charge delivery capability (CDC) of the electrode by measuring the CDCs of two-channel electrode arrays. The dimensions of each electrode of the two-channel array were the same as those of each electrode formed on the 10 x 10 array. The results suggest that for cathodic-first (CF) pulses, 80% of electrodes surpassed our development target of 318 microC/cm2, which corresponds to the charge density of pulses of 500 micros duration and 200 microA amplitude for a 200-microm-diameter planar electrode.

In-Situ through-Plane Measurements of Ionic Potential Distributions in Non-Precious Metal Catalyst Electrode for PEFC

DOE PAGES

Komini Babu, S.; Chung, H. T.; Zelenay, P.; ...

2015-09-14

This manuscript presents micro-scale experimental diagnostics and nano-scale resolution X-ray imaging applied to the study of proton conduction in non-precious metal catalyst (NPMC) fuel cell cathodes. NPMC’s have the potential to reduce the cost of the fuel cell for multiple applications. But, NPMC electrodes are inherently thick compared to the convention Pt/C electrode due to the lower volumetric activity. Thus, the electric potential drop through the Nafion across the electrode thickness can yield significant performance loss. Ionomer distributions in the NPMC electrodes with different ionomer loading are extracted from morphological data using nanoscale X-ray computed tomography (nano-XCT) imaging of themore » cathode. Microstructured electrode scaffold (MES) diagnostics are used to measure the electrolyte potential at discrete points across the thickness of the catalyst layer. When using that apparatus, the electrolyte potential drop, the through-thickness reaction distribution, and the proton conductivity are measured and correlated with the corresponding Nafion morphology and cell performance.« less

Commercial materials as cathode for hydrogen production in microbial electrolysis cell.

PubMed

Farhangi, Sara; Ebrahimi, Sirous; Niasar, Mojtaba Shariati

2014-10-01

The use of commercial electrodes as cathodes in a single-chamber microbial electrolysis cell has been investigated. The cell was operated in sequencing batch mode and the performance of the electrodes was compared with carbon cloth containing 0.5 mg Pt cm(-2). Overall H2 recovery [Formula: see text] was 66.7 ± 1.4, 58.7 ± 1.1 and 55.5 ± 1.5 % for Pt/CC, Ni and Ti mesh electrodes, respectively. Columbic efficiencies of the three cathodes were in the same range (74.8 ± 1.5, 77.6 ± 1.7 and 75.7 ± 1.2 % for Pt/CC, Ni and Ti mesh electrodes, respectively). A similar performance for the three cathodes under near-neutral pH and ambient temperature was obtained. The commercial electrodes are much cheaper than carbon cloth containing Pt. Low cost and good performance of these electrodes suggest they are suitable cathode materials for large scale application.

Reduction of turbidity and chromium content of tannery wastewater by electrocoagulation process.

PubMed

2018-02-12

The present study is carried out to remove the chromium and turbidity from tannery wastewater by the electrocoagulationprocess with aluminum electrodes. This experimental study is performed using a batch system. The applied pilot comprises a reactor containing two parallel metal electrodes (Al). The latter are connected as mono polar and a different potential is applied between them. Several working parameters, such as applied potential difference, electrolysis time, active electrode surface, inter-electrode distance and pH of the medium have been studied to achieve higher removal efficiency.The treatment achieved a maximum reduction of 99% for the turbidity and 93% for the chromium under the following conditions: a potential difference: 15V; electrodes surface: 45cm2, inter-electrode distance: 1cm; raw water pH (6.1) and a contact time of 90 min. Considering the obtained efficiency in the present study, electrocoagulation process has the potential to be utilized for the cost-effective removal of pollutants from wastewater.

Recycling Carbon Dioxide into Sustainable Hydrocarbon Fuels: Electrolysis of Carbon Dioxide and Water

NASA Astrophysics Data System (ADS)

Graves, Christopher Ronald

Great quantities of hydrocarbon fuels will be needed for the foreseeable future, even if electricity based energy carriers begin to partially replace liquid hydrocarbons in the transportation sector. Fossil fuels and biomass are the most common feedstocks for production of hydrocarbon fuels. However, using renewable or nuclear energy, carbon dioxide and water can be recycled into sustainable hydrocarbon fuels in non-biological processes which remove oxygen from CO2 and H2O (the reverse of fuel combustion). Capture of CO2 from the atmosphere would enable a closed-loop carbon-neutral fuel cycle. The purpose of this work was to develop critical components of a system that recycles CO2 into liquid hydrocarbon fuels. The concept is examined at several scales, beginning with a broad scope analysis of large-scale sustainable energy systems and ultimately studying electrolysis of CO 2 and H2O in high temperature solid oxide cells as the heart of the energy conversion, in the form of three experimental studies. The contributions of these studies include discoveries about electrochemistry and materials that could significantly improve the overall energy use and economics of the CO2-to-fuels system. The broad scale study begins by assessing the sustainability and practicality of the various energy carriers that could replace petroleum-derived hydrocarbon fuels, including other hydrocarbons, hydrogen, and storage of electricity on-board vehicles in batteries, ultracapacitors, and flywheels. Any energy carrier can store the energy of any energy source. This sets the context for CO2 recycling -- sustainable energy sources like solar and wind power can be used to provide the most energy-dense, convenient fuels which can be readily used in the existing infrastructure. The many ways to recycle CO2 into hydrocarbons, based on thermolysis, thermochemical loops, electrolysis, and photoelectrolysis of CO2 and/or H 2O, are critically reviewed. A process based on high temperature co-electrolysis of CO2 and H2O to produce syngas (CO/H2 mixture) is identified as a promising method. High temperature electrolysis makes very efficient use of electricity and heat (near-100% electricity-to-syngas efficiency), provides high reaction rates, and the syngas produced can be catalytically converted to hydrocarbons in well-known fuel synthesis reactors (e.g. Fischer-Tropsch). The experimental studies of high temperature electrolysis are made at different scales -- at the cell level, electrode level, and in materials and microstructure development. The results include cell performance and durability, insight into electrode reaction mechanisms, and new high-performance electrode materials. The experimental studies make extensive use of electrochemical impedance spectroscopy and systematic variation of test conditions to examine the electrochemical phenomena. Variation of the material composition itself within families of related materials was an additional parameter used in the electrode level and materials studies that revealed more information than studying a single material would have. Using full cells, the performance and durability of a solid oxide cell applied for co-electrolysis of CO2 and H2O was investigated. High initial performance was observed but the long-term durability needs to be improved. Based on these results, an analysis of the energy balance and economics of an electrolysis-based synthetic fuel production process, including CO2 air capture and Fischer-Tropsch fuel synthesis, determined that the system can feasibly operate at 70% electricity-to-liquid fuel efficiency (higher heating value basis) and that the price of electricity needed to produce competitive synthetic gasoline (at USD2/gal, or 0.53/L, wholesale) is 2-3 U.S. cents per kWh. For 3/gal (0.78/L) gasoline, 4-5 cents per kWh is needed. Fuel production may already be economical in some regions that have inexpensive renewable electricity, such as Iceland. The dominant costs of the process are the electricity cost and the capital cost of the electrolyzer, and this capital cost is significantly increased when operating intermittently (on renewable power sources such as solar and wind). Low cell internal resistance, low degradation, and low manufacturing cost each contribute to a low electrolyzer capital cost, and can be traded off. One straightforward path to affordability is by improving the durability of the high current density cell operation (≥1 A/cm2) that is already possible with these cells. The negative-electrode, a composite of nickel and yttria-stabilized zirconia (YSZ), is often the major site of cell degradation, including in the co-electrolysis results presented here. To better understand the reaction mechanisms at the negative-electrode that limit performance and durability, different metal electrodes including nickel were studied using a simplified point-contact electrode geometry with a well-defined three-phase boundary (TPB; the electrode/electrolyte/gas interface where the electrochemical reactions take place). The simple geometry is useful for isolating the electrochemical properties without the effects of the complex microstructure of technological porous electrodes. Widely different impedance responses of the different metals to the same changes in test conditions (gas composition, temperature, and polarization) were observed, indicating that the same reaction mechanisms are not shared by the different metals, contrary to some recent studies. Evidence was also found that supports the explanation that impurities segregated to the TPB play a major role and are largely responsible for inconsistencies in the electrode kinetics literature. The significance of microstructure at the TPB was also revealed -- the electrode polarization resistance was reduced by an order of magnitude when subjected to extreme conditions of oxidation-reduction and strong cathodic polarization, which induced the formation of a micro/nanostructured TPB. Possible reaction mechanisms for H2O/CO2 reduction and H2/CO oxidation are discussed. Novel ceramic materials based on molybdates with varying Mo valence were synthesized as possible alternative negative-electrode materials. The phase, stability, microstructure and electrical conductivity were characterized. The electrochemical activity for H2O/CO2 reduction and H2/CO oxidation was studied using simplified geometry electrodes, similar to the metals study. Unique phenomena were observed for some of the molybdate materials -- they decomposed into multiple phases and formed a nanostructured surface upon exposure to operating conditions (in certain reducing atmospheres). The new phases and surface features enhanced the electronic conductivity and electrocatalytic activity. Preparing an electrode by performing controlled decomposition to form multiple desirable phases and a desirable microstructure (which can take place in situ) using these materials is a novel way to produce potentially high-performance electrodes for solid oxide cells. By modifying the composition, it was possible to prevent decomposition. Other members of the molybdate family exhibited similarly high electronic conductivity and electrocatalytic activity but did not decompose. The high activity was the result of a different mechanism, probably related to the defect chemistry of the material. The polarization resistances of the best molybdate materials were two orders of magnitude lower than that of donor-doped strontium titanates. Many of the molybdate materials were significantly activated by cathodic polarization, and they exhibited higher performance for cathodic (electrolysis) polarization than anodic (fuel cell) polarization, which makes them especially interesting for use in electrolysis electrodes. Whereas nearly all of the molybdates showed higher performance for H2O electrolysis than CO2 electrolysis, one with vanadium showed nearly equal performance, and a non-molybdate which exhibits some complementary properties to the best molybdates, Gd-doped ceria in nanoparticle form, was found to be an excellent electrocatalyst for CO2 electrolysis and CO oxidation (moreso than for H2O/H2 for which it is known to be good).

Emerging materials for transparent conductive electrodes and their applications in photovoltaics

NASA Astrophysics Data System (ADS)

Zhu, Zhaozhao

Clean and affordable energy, especially solar energy, is becoming more and more important as our annual total energy consumption keeps rising. However, to make solar energy more affordable and accessible, the cost for fabrication, transportation and assembly of all components need to be reduced. As a crucial component for solar cells, transparent conductive electrode (TCE) can determine the cost and performance. A light weight, easy-to-fabricate and cost-effective new generation TCE is thus needed. While indium-doped tin oxide (ITO) has been the most widely used material for commercial applications as TCEs, its cost has gone up due to the limited global supply of indium. This is not only due to the scarcity of the element itself, but also the massive production of various opto-electronic devices such as TVs, smartphones and tablets. In order to reduce the cost for fabricating large area solar cells, substitute materials for ITO should be developed. These materials should have similar optical transmittance in the visible wavelength range, as well as similar electrical conductivity (sheet resistance) to ITO. This work starts with synthesizing ITO-replacing nano-materials, such as copper nanowires (CuNWs), derivative zinc oxide (ZnO) thin films, reduced graphene oxide (rGO) and so on. Further, we applied various deposition techniques, including spin-coating, spray-coating, Mayer-rod coating, filtration and transferring, to coat transparent substrates with these materials in order to fabricate TCEs. We characterize these materials and analyze their electrical/optical properties as TCEs. Additionally, these fabricated single-material-based TCEs were tested in various lab conditions, and their shortcomings (instability, rigidity, etc.) were highlighted. In order to address these issues, we hybridized the different materials to combine their strengths and compared the properties to single-material based TCEs. The multiple hybridized TCEs have comparable optical/electrical metrics to ITO. The doped-ZnO TCEs exhibit high optical transmittance over 90% in the visible range and low sheet resistance under 200 O/sq. For CuNW-based composite electrodes, ˜ 85% optical transmittance and ˜ 25 O/sq were observed. Meanwhile, the hybridization of materials adds additional features such as flexibility or resistance to corrosion. Finally, as a proof of concept, the CuNW-based composite TCEs were tested in dye-sensitized solar cells (DSSCs), showing similar performance to ITO based samples.

Nanocomposite of polyaniline nanorods grown on graphene nanoribbons for highly capacitive pseudocapacitors.

PubMed

Li, Lei; Raji, Abdul-Rahman O; Fei, Huilong; Yang, Yang; Samuel, Errol L G; Tour, James M

2013-07-24

A facile and cost-effective approach to the fabrication of a nanocomposite material of polyaniline (PANI) and graphene nanoribbons (GNRs) has been developed. The morphology of the composite was characterized by scanning electron microscopy, transmission electron microscopy, X-ray photoelectron microscopy, and X-ray diffraction analysis. The resulting composite has a high specific capacitance of 340 F/g and stable cycling performance with 90% capacitance retention over 4200 cycles. The high performance of the composite results from the synergistic combination of electrically conductive GNRs and highly capacitive PANI. The method developed here is practical for large-scale development of pseudocapacitor electrodes for energy storage.

A low-cost, scalable, current-sensing digital headstage for high channel count μECoG.

PubMed

Trumpis, Michael; Insanally, Michele; Zou, Jialin; Elsharif, Ashraf; Ghomashchi, Ali; Sertac Artan, N; Froemke, Robert C; Viventi, Jonathan

2017-04-01

High channel count electrode arrays allow for the monitoring of large-scale neural activity at high spatial resolution. Implantable arrays featuring many recording sites require compact, high bandwidth front-end electronics. In the present study, we investigated the use of a small, light weight, and low cost digital current-sensing integrated circuit for acquiring cortical surface signals from a 61-channel micro-electrocorticographic (μECoG) array. We recorded both acute and chronic μECoG signal from rat auditory cortex using our novel digital current-sensing headstage. For direct comparison, separate recordings were made in the same anesthetized preparations using an analog voltage headstage. A model of electrode impedance explained the transformation between current- and voltage-sensed signals, and was used to reconstruct cortical potential. We evaluated the digital headstage using several metrics of the baseline and response signals. The digital current headstage recorded neural signal with similar spatiotemporal statistics and auditory frequency tuning compared to the voltage signal. The signal-to-noise ratio of auditory evoked responses (AERs) was significantly stronger in the current signal. Stimulus decoding based on true and reconstructed voltage signals were not significantly different. Recordings from an implanted system showed AERs that were detectable and decodable for 52 d. The reconstruction filter mitigated the thermal current noise of the electrode impedance and enhanced overall SNR. We developed and validated a novel approach to headstage acquisition that used current-input circuits to independently digitize 61 channels of μECoG measurements of the cortical field. These low-cost circuits, intended to measure photo-currents in digital imaging, not only provided a signal representing the local cortical field with virtually the same sensitivity and specificity as a traditional voltage headstage but also resulted in a small, light headstage that can easily be scaled to record from hundreds of channels.

A low-cost, scalable, current-sensing digital headstage for high channel count μECoG

NASA Astrophysics Data System (ADS)

Trumpis, Michael; Insanally, Michele; Zou, Jialin; Elsharif, Ashraf; Ghomashchi, Ali; Sertac Artan, N.; Froemke, Robert C.; Viventi, Jonathan

2017-04-01

Objective. High channel count electrode arrays allow for the monitoring of large-scale neural activity at high spatial resolution. Implantable arrays featuring many recording sites require compact, high bandwidth front-end electronics. In the present study, we investigated the use of a small, light weight, and low cost digital current-sensing integrated circuit for acquiring cortical surface signals from a 61-channel micro-electrocorticographic (μECoG) array. Approach. We recorded both acute and chronic μECoG signal from rat auditory cortex using our novel digital current-sensing headstage. For direct comparison, separate recordings were made in the same anesthetized preparations using an analog voltage headstage. A model of electrode impedance explained the transformation between current- and voltage-sensed signals, and was used to reconstruct cortical potential. We evaluated the digital headstage using several metrics of the baseline and response signals. Main results. The digital current headstage recorded neural signal with similar spatiotemporal statistics and auditory frequency tuning compared to the voltage signal. The signal-to-noise ratio of auditory evoked responses (AERs) was significantly stronger in the current signal. Stimulus decoding based on true and reconstructed voltage signals were not significantly different. Recordings from an implanted system showed AERs that were detectable and decodable for 52 d. The reconstruction filter mitigated the thermal current noise of the electrode impedance and enhanced overall SNR. Significance. We developed and validated a novel approach to headstage acquisition that used current-input circuits to independently digitize 61 channels of μECoG measurements of the cortical field. These low-cost circuits, intended to measure photo-currents in digital imaging, not only provided a signal representing the local cortical field with virtually the same sensitivity and specificity as a traditional voltage headstage but also resulted in a small, light headstage that can easily be scaled to record from hundreds of channels.

A low-cost, scalable, current-sensing digital headstage for high channel count μECoG

PubMed Central

Trumpis, Michael; Insanally, Michele; Zou, Jialin; Elsharif, Ashraf; Ghomashchi, Ali; Artan, N. Sertac; Froemke, Robert C.; Viventi, Jonathan

2017-01-01

Objective High channel count electrode arrays allow for the monitoring of large-scale neural activity at high spatial resolution. Implantable arrays featuring many recording sites require compact, high bandwidth front-end electronics. In the present study, we investigated the use of a small, light weight, and low cost digital current-sensing integrated circuit for acquiring cortical surface signals from a 61-channel micro-electrocorticographic (μECoG) array. Approach We recorded both acute and chronic μECoG signal from rat auditory cortex using our novel digital current-sensing headstage. For direct comparison, separate recordings were made in the same anesthetized preparations using an analog voltage headstage. A model of electrode impedance explained the transformation between current- and voltage-sensed signals, and was used to reconstruct cortical potential. We evaluated the digital headstage using several metrics of the baseline and response signals. Main results The digital current headstage recorded neural signal with similar spatiotemporal statistics and auditory frequency tuning compared to the voltage signal. The signal-to-noise ratio of auditory evoked responses (AERs) was significantly stronger in the current signal. Stimulus decoding based on true and reconstructed voltage signals were not significantly different. Recordings from an implanted system showed AERs that were detectable and decodable for 52 days. The reconstruction filter mitigated the thermal current noise of the electrode impedance and enhanced overall SNR. Significance We developed and validated a novel approach to headstage acquisition that used current-input circuits to independently digitize 61 channels of μECoG measurements of the cortical field. These low-cost circuits, intended to measure photo-currents in digital imaging, not only provided a signal representing the local cortical field with virtually the same sensitivity and specificity as a traditional voltage headstage but also resulted in a small, light headstage that can easily be scaled to record from hundreds of channels. PMID:28102827

Dry Electrodes for ECG and Pulse Transit Time for Blood Pressure: A Wearable Sensor and Smartphone Communication Approach

NASA Astrophysics Data System (ADS)

Shyamkumar, Prashanth

Cardiovascular Diseases (CVDs) have been a major cause for deaths in both men and women in United States. Cerebrovascular Diseases like Strokes are known to have origins in CVDs as well. Moreover, nearly 18 Million Americans have a history of myocardial infarction and are currently undergoing cardiac rehabilitation. Consequently, CVDs are the highest costing disease groups and cost more than all types of cancer combined. However, significant cost reduction is possible through the effective use of the vast advances in embedded and pervasive electronic devices for healthcare. These devices can automate and move a significant portion of disease management to the patient's home through cyber connectivity, a concept known as point-of-care (POC) diagnostics and healthcare services. POC can minimize hospital visits and potentially avoid admission altogether with prognostic tools that give advanced notice of any abnormalities or chronic illnesses so that the treatment can be planned in advance. The POC concept requires continuous remote health monitoring. Therefore, the various sensors needed for comprehensive monitoring need to be worn daily and throughout the day. Moreover, true "roaming" capability is necessary so that it does not restrict the user's travel or his/her quotidian activities. Two biomedical signals namely, Electrocardiogram (ECG) and Blood Pressure are important diagnostic tests in assessing the cardiac health of a person. To that end, the research presented in this thesis: First , describes the development of a remote monitoring solution based on Bluetooth(TM), smartphones and cyber infrastructure for cardiac care called e-nanoflex. Second, Sensors for ECG that are compatible with everyday life style namely, (a) dry, gel-less vertically aligned gold nanowire electrodes, (b) dry textile-based conductive sensor electrodes to address the need for this technology to monitor cardiovascular diseases in women are tested with e-nanoflex and discussed. Third, non-invasive, cuff-less Blood pressure estimation based on Pulse Transit Time with multiple synchronized sensor nodes, is implemented with e-nanoflex and the results are discussed.

Final Technical Report, Oct 2004 - Nov. 2006, High Performance Flexible Reversible Solid Oxide Fuel Cell

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guan, Jie; Minh, Nguyen

This report summarizes the work performed for the program entitled “High Performance Flexible Reversible Solid Oxide Fuel Cell” under Cooperative Agreement DE-FC36-04GO14351 for the U. S. Department of Energy. The overall objective of this project is to demonstrate a single modular stack that generates electricity from a variety of fuels (hydrogen and other fuels such as biomass, distributed natural gas, etc.) and when operated in the reverse mode, produces hydrogen from steam. This project has evaluated and selected baseline cell materials, developed a set of materials for oxygen and hydrogen electrodes, and optimized electrode microstructures for reversible solid oxide fuelmore » cells (RSOFCs); and demonstrated the feasibility and operation of a RSOFC multi-cell stack. A 10-cell reversible SOFC stack was operated over 1000 hours alternating between fuel cell (with hydrogen and methane as fuel) and steam electrolysis modes. The stack ran very successfully with high power density of 480 mW/cm2 at 0.7V and 80% fuel utilization in fuel cell mode and >6 SLPM hydrogen production in steam electrolysis mode using about 1.1 kW electrical power. The hydrogen generation is equivalent to a specific capability of 2.59 Nm3/m2 with electrical energy demand of 3 kWh/Nm3. The performance stability in electrolysis mode was improved vastly during the program with a degradation rate reduction from 8000 to 200 mohm-cm2/1000 hrs. This was accomplished by increasing the activity and improving microstructure of the oxygen electrode. Both cost estimate and technology assessment were conducted. Besides the flexibility running under both fuel cell mode and electrolysis mode, the reversible SOFC system has the potentials for low cost and high efficient hydrogen production through steam electrolysis. The cost for hydrogen production at large scale was estimated at ~$2.7/kg H2, comparing favorably with other electrolysis techology.« less

Cosolvent electrolytes for electrochemical devices

DOEpatents

Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

2018-01-23

A method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

Cosolvent electrolytes for electrochemical devices

DOEpatents

Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

2018-02-13

A system and method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

Cosolvent electrolytes for electrochemical devices

DOEpatents

Wessells, Colin Deane; Firouzi, Ali; Motallebi, Shahrokh; Strohband, Sven

2018-05-15

A system and method for stabilizing electrodes against dissolution and/or hydrolysis including use of cosolvents in liquid electrolyte batteries for three purposes: the extension of the calendar and cycle life time of electrodes that are partially soluble in liquid electrolytes, the purpose of limiting the rate of electrolysis of water into hydrogen and oxygen as a side reaction during battery operation, and for the purpose of cost reduction.

Low-cost and disposable sensors for the simultaneous determination of coenzyme Q10 and α-lipoic acid using manganese (IV) oxide-modified screen-printed graphene electrodes.

PubMed

Charoenkitamorn, Kanokwan; Chaiyo, Sudkate; Chailapakul, Orawon; Siangproh, Weena

2018-04-03

In this work, for the first time, manganese (IV) oxide-modified screen-printed graphene electrodes (MnO 2 /SPGEs) were developed for the simultaneous electrochemical detection of coenzyme Q10 (CoQ10) and α-lipoic acid (ALA). This sensor exhibits attractive benefits such as simplicity, low production costs, and disposability. Cyclic voltammetry (CV) was used to characterize the electrochemical behavior of the analyte and investigate the capacitance and electroactive surface area of the unmodified and modified electrode surfaces. The electrochemical behavior of CoQ10 and ALA on MnO 2 /SPGEs was also discussed. Additionally, square wave anodic stripping voltammetry (SWASV) was used for the quantitative determination of CoQ10 and ALA. Under optimal conditions, the obtained signals are linear in the concentration range from 2.0 to 75.0 μg mL -1 for CoQ10 and 0.3-25.0 μg mL -1 for ALA. The low limits of detection (LODs) were found to be 0.56 μg mL -1 and 0.088 μg mL -1 for CoQ10 and ALA, respectively. Moreover, we demonstrated the utility and applicability of the MnO 2 /SPGE sensor through simultaneous measurements of CoQ10 and ALA in dietary supplements. The sensor provides high accuracy measurements, exhibiting its high potential for practical applications. Copyright © 2017 Elsevier B.V. All rights reserved.

Fabrication of a Miniature Multi-Parameter Sensor Chip for Water Quality Assessment

PubMed Central

Zhou, Bo; Bian, Chao; Tong, Jianhua; Xia, Shanhong

2017-01-01

Water contamination is a main inducement of human diseases. It is an important step to monitor the water quality in the water distribution system. Due to the features of large size, high cost, and complicated structure of traditional water determination sensors and devices, it is difficult to realize real-time water monitoring on a large scale. In this paper, we present a multi-parameter sensor chip, which is miniature, low-cost, and robust, to detect the pH, conductivity, and temperature of water simultaneously. The sensor chip was fabricated using micro-electro-mechanical system (MEMS) techniques. Iridium oxide film was electrodeposited as the pH-sensing material. The atomic ratio of Ir(III) to Ir(IV) is about 1.38 according to the X-ray photoelectron spectroscopy (XPS) analysis. The pH sensing electrode showed super-Nernstian response (−67.60 mV/pH) and good linearity (R2 = 0.9997), in the range of pH 2.22 to pH 11.81. KCl-agar and epoxy were used as the electrolyte layer and liquid junction for the solid-state reference electrode, respectively, and its potential stability in deionized water was 56 h. The conductivity cell exhibited a linear determination range from 21.43 μS/cm to 1.99 mS/cm, and the electrode constant was 1.566 cm−1. Sensitivity of the temperature sensor was 5.46 Ω/°C. The results indicate that the developed sensor chip has potential application in water quality measurements. PMID:28098824

Toward greener lithium-ion batteries: Aqueous binder-based LiNi0.4Co0.2Mn0.4O2 cathode material with superior electrochemical performance

NASA Astrophysics Data System (ADS)

Chen, Zhen; Kim, Guk-Tae; Chao, Dongliang; Loeffler, Nicholas; Copley, Mark; Lin, Jianyi; Shen, Zexiang; Passerini, Stefano

2017-12-01

This work reports the performance of LiNi0.4Co0.2Mn0.4O2 electrodes employing sodium carboxymethyl cellulose as the binder (CMC/NCM). Compared with conventional organic PVDF-based electrodes, the CMC/NCM electrodes display very uniform distribution of NCM and carbon particles together with strong adhesion among the particles and with the current collector, leading to significantly mitigated crack formation and delamination of the electrode upon repeated delithiation/lithiation processes. Additionally, these electrodes offer enhanced Li+ diffusion kinetics, reduced polarization, therefore, excellent high C-rate capability, and extremely stable cycling performance even at elevated temperature (60 °C). Benefiting from the features of low cost, environmentally friendliness, and easy disposability-recyclability, the water-soluble CMC is a promising binder for practical application in energy storage systems.

Detection of Antibiotics and Evaluation of Antibacterial Activity with Screen-Printed Electrodes

PubMed Central

Titoiu, Ana Maria; Marty, Jean-Louis

2018-01-01

This review provides a brief overview of the fabrication and properties of screen-printed electrodes and details the different opportunities to apply them for the detection of antibiotics, detection of bacteria and antibiotic susceptibility. Among the alternative approaches to costly chromatographic or ELISA methods for antibiotics detection and to lengthy culture methods for bacteria detection, electrochemical biosensors based on screen-printed electrodes present some distinctive advantages. Chemical and (bio)sensors for the detection of antibiotics and assays coupling detection with screen-printed electrodes with immunomagnetic separation are described. With regards to detection of bacteria, the emphasis is placed on applications targeting viable bacterial cells. While the electrochemical sensors and biosensors face many challenges before replacing standard analysis methods, the potential of screen-printed electrodes is increasingly exploited and more applications are anticipated to advance towards commercial analytical tools. PMID:29562637

HED-TIE: A wafer-scale approach for fabricating hybrid electronic devices with trench isolated electrodes

NASA Astrophysics Data System (ADS)

Banerjee, Sreetama; Bülz, Daniel; Solonenko, Dmytro; Reuter, Danny; Deibel, Carsten; Hiller, Karla; Zahn, Dietrich R. T.; Salvan, Georgeta

2017-05-01

Organic-inorganic hybrid electronic devices (HEDs) offer opportunities for functionalities that are not easily obtainable with either organic or inorganic materials individually. In the strive for down-scaling the channel length in planar geometry HEDs, the best results were achieved with electron beam lithography or nanoimprint lithography. Their application on the wafer level is, however, cost intensive and time consuming. Here, we propose trench isolated electrode (TIE) technology as a fast, cost effective, wafer-level approach for the fabrication of planar HEDs with electrode gaps in the range of 100 nm. We demonstrate that the formation of the organic channel can be realized by deposition from solution as well as by the thermal evaporation of organic molecules. To underline one key feature of planar HED-TIEs, namely full accessibility of the active area of the devices by external stimuli such as light, 6,13-bis (triisopropylsilylethynyl) (TIPS)-pentacene/Au HED-TIEs are successfully tested for possible application as hybrid photodetectors in the visible spectral range.

Florida Hydrogen Initiative

DOE Office of Scientific and Technical Information (OSTI.GOV)

Block, David L

2013-06-30

The Florida Hydrogen Initiative (FHI) was a research, development and demonstration hydrogen and fuel cell program. The FHI program objectives were to develop Florida?s hydrogen and fuel cell infrastructure and to assist DOE in its hydrogen and fuel cell activities The FHI program funded 12 RD&D projects as follows: Hydrogen Refueling Infrastructure and Rental Car Strategies -- L. Lines, Rollins College This project analyzes strategies for Florida's early stage adaptation of hydrogen-powered public transportation. In particular, the report investigates urban and statewide network of refueling stations and the feasibility of establishing a hydrogen rental-car fleet based in Orlando. Methanol Fuelmore » Cell Vehicle Charging Station at Florida Atlantic University ? M. Fuchs, EnerFuel, Inc. The project objectives were to design, and demonstrate a 10 kWnet proton exchange membrane fuel cell stationary power plant operating on methanol, to achieve an electrical energy efficiency of 32% and to demonstrate transient response time of less than 3 milliseconds. Assessment of Public Understanding of the Hydrogen Economy Through Science Center Exhibits, J. Newman, Orlando Science Center The project objective was to design and build an interactive Science Center exhibit called: ?H2Now: the Great Hydrogen Xchange?. On-site Reformation of Diesel Fuel for Hydrogen Fueling Station Applications ? A. Raissi, Florida Solar Energy Center This project developed an on-demand forecourt hydrogen production technology by catalytically converting high-sulfur hydrocarbon fuels to an essentially sulfur-free gas. The removal of sulfur from reformate is critical since most catalysts used for the steam reformation have limited sulfur tolerance. Chemochromic Hydrogen Leak Detectors for Safety Monitoring ? N. Mohajeri and N. Muradov, Florida Solar Energy Center This project developed and demonstrated a cost-effective and highly selective chemochromic (visual) hydrogen leak detector for safety monitoring at any facility engaged in transport, handling and use of hydrogen. Development of High Efficiency Low Cost Electrocatalysts for Hydrogen Production and PEM Fuel Cell Applications ? M. Rodgers, Florida Solar Energy Center The objective of this project was to decrease platinum usage in fuel cells by conducting experiments to improve catalyst activity while lowering platinum loading through pulse electrodeposition. Optimum values of several variables during electrodeposition were selected to achieve the highest electrode performance, which was related to catalyst morphology. Understanding Mechanical and Chemical Durability of Fuel Cell Membrane Electrode Assemblies ? D. Slattery, Florida Solar Energy Center The objective of this project was to increase the knowledge base of the degradation mechanisms for membranes used in proton exchange membrane fuel cells. The results show the addition of ceria (cerium oxide) has given durability improvements by reducing fluoride emissions by an order of magnitude during an accelerated durability test. Production of Low-Cost Hydrogen from Biowaste (HyBrTec?) ? R. Parker, SRT Group, Inc., Miami, FL This project developed a hydrogen bromide (HyBrTec?) process which produces hydrogen bromide from wet-cellulosic waste and co-produces carbon dioxide. Eelectrolysis dissociates hydrogen bromide producing recyclable bromine and hydrogen. A demonstration reactor and electrolysis vessel was designed, built and operated. Development of a Low-Cost and High-Efficiency 500 W Portable PEMFC System ? J. Zheng, Florida State University, H. Chen, Bing Energy, Inc. The objectives of this project were to develop a new catalyst structures comprised of highly conductive buckypaper and Pt catalyst nanoparticles coated on its surface and to demonstrate fuel cell efficiency improvement and durability and cell cost reductions in the buckypaper based electrodes. Development of an Interdisciplinary Hydrogen and Fuel Cell Technology Academic Program ? J. Politano, Florida Institute of Technology, Melbourne, FL This project developed a hydrogen and fuel cell technology academic program at Florida Institute of Technology in Melbourne, Florida. Design and Development of an Advanced Hydrogen Storage System using Novel Materials ? E. Stefanakos, University of South Florida The goal of this project was to design and develop novel conducting polymeric nanomaterials for on-board hydrogen storage. The project approach was to examine synthesis of polyaniline solid state hydrogen storage materials. Advanced HiFoil ? Bipolar Plates ? J. Braun, M. Fuchs, EnerFuel, Inc. The goal of this project was to provide a durable, low cost bipolar plate for high temperature proton exchange membrane fuel cells. The project results produced a durable, low cost bipolar plate with very high in-plane thermal conductivity.« less

Development of Anode-Supported Single Cells and Small Stacks for Intermediate Temperature Sofc at Kepri

NASA Astrophysics Data System (ADS)

Yoo, Y.-S.; Park, J.-W.; Park, J.-K.; Lim, H.-C.; Oh, J.-M.; Bae, J.-M.

Recent results on intermediate temperature-operating solid oxide fuel cells (IT-SOFC) are mainly focused on getting the higher performance of single cell at lower operating temperature, especially using planar type. We have started a project to develop 1 kW-class SOFC system for Residential Power Generation(RPG) application. For a 1 kW-class SOFC stack that can be operated at intermediate temperatures, we have developed anode-supported, planar type SOFC to have advantages for commercialization of SOFCs considering mass production and using cost-effective interconnects such as ferritic stainless steels. At higher temperature, performance of SOFC can be increased due to higher electrochemical activity of electrodes and lower ohmic losses, but the surface of metallic interconnects at cathode side is rapidly oxidized into resistive oxide scale. For efficient operation of SOFC at reduced temperature at, firstly we have developed alternative cathode materials of LSCF instead of LSM to get higher performance of electrodes, and secondly introduced functional-layered structure at anode side. The I-V and AC impedance characteristics of improved single cells and small stacks were evaluated at intermediate temperatures (650°C and 750°C) using hydrogen gas as a fuel.

Absorptive carbon nanotube electrodes: Consequences of optical interference loss in thin film solar cells

NASA Astrophysics Data System (ADS)

Tait, Jeffrey G.; de Volder, Michaël F. L.; Cheyns, David; Heremans, Paul; Rand, Barry P.

2015-04-01

A current bottleneck in the thin film photovoltaic field is the fabrication of low cost electrodes. We demonstrate ultrasonically spray coated multiwalled carbon nanotube (CNT) layers as opaque and absorptive metal-free electrodes deposited at low temperatures and free of post-deposition treatment. The electrodes show sheet resistance as low as 3.4 Ω □-1, comparable to evaporated metallic contacts deposited in vacuum. Organic photovoltaic devices were optically simulated, showing comparable photocurrent generation between reflective metal and absorptive CNT electrodes for photoactive layer thickness larger than 600 nm when using archetypal poly(3-hexylthiophene) (P3HT) : (6,6)-phenyl C61-butyric acid methyl ester (PCBM) cells. Fabricated devices clearly show that the absorptive CNT electrodes display comparable performance to solution processed and spray coated Ag nanoparticle devices. Additionally, other candidate absorber materials for thin film photovoltaics were simulated with absorptive contacts, elucidating device design in the absence of optical interference and reflection.A current bottleneck in the thin film photovoltaic field is the fabrication of low cost electrodes. We demonstrate ultrasonically spray coated multiwalled carbon nanotube (CNT) layers as opaque and absorptive metal-free electrodes deposited at low temperatures and free of post-deposition treatment. The electrodes show sheet resistance as low as 3.4 Ω □-1, comparable to evaporated metallic contacts deposited in vacuum. Organic photovoltaic devices were optically simulated, showing comparable photocurrent generation between reflective metal and absorptive CNT electrodes for photoactive layer thickness larger than 600 nm when using archetypal poly(3-hexylthiophene) (P3HT) : (6,6)-phenyl C61-butyric acid methyl ester (PCBM) cells. Fabricated devices clearly show that the absorptive CNT electrodes display comparable performance to solution processed and spray coated Ag nanoparticle devices. Additionally, other candidate absorber materials for thin film photovoltaics were simulated with absorptive contacts, elucidating device design in the absence of optical interference and reflection. Electronic supplementary information (ESI) available: An animation of the MWCNT spray coating process, and five figures, including: a photograph of completed devices with MWCNT electrodes, performance metrics for devices with photoactive layer thickness up to 3000 nm, contour plots of simulated devices used to build Fig. 5, simulation data for perovskite devices, and a contour plot of the simplified equation of photoactive layer thickness required to attain a specified photocurrent ratio (x-axis) and absorption coefficient (y-axis). See DOI: 10.1039/c5nr01119a

Virtual electrochemical nitric oxide analyzer using copper, zinc superoxide dismutase immobilized on carbon nanotubes in polypyrrole matrix.

PubMed

Madasamy, Thangamuthu; Pandiaraj, Manickam; Balamurugan, Murugesan; Karnewar, Santosh; Benjamin, Alby Robson; Venkatesh, Krishna Arun; Vairamani, Kanagavel; Kotamraju, Srigiridhar; Karunakaran, Chandran

2012-10-15

In this work, we have designed and developed a novel and cost effective virtual electrochemical analyzer for the measurement of NO in exhaled breath and from hydrogen peroxide stimulated endothelial cells using home-made potentiostat. Here, data acquisition system (NI MyDAQ) was used to acquire the data from the electrochemical oxidation of NO mediated by copper, zinc superoxide dismutase (Cu,ZnSOD). The electrochemical control programs (graphical user-interface software) were developed using LabVIEW 10.0 to sweep the potential, acquire the current response and process the acquired current signal. The Cu,ZnSOD (SOD1) immobilized on the carbon nanotubes in polypyrrole modified platinum electrode was used as the NO biosensor. The electrochemical behavior of the SOD1 modified electrode exhibited the characteristic quasi-reversible redox peak at the potential, +0.06 V vs. Ag/AgCl. The biological interferences were eliminated by nafion coated SOD1 electrode and then NO was measured selectively. Further, this biosensor showed a wide linear range of response over the concentration of NO from 0.1 μM to 1 mM with a detection limit of 0.1 μM and high sensitivity of 1.1 μA μM(-1). The electroanalytical results obtained here using the developed virtual electrochemical instrument were also compared with the standard cyclic voltammetry instrument and found in agreement with each other. Copyright © 2012 Elsevier B.V. All rights reserved.

Poly(dimethylsiloxane) cross-linked carbon paste electrodes for microfluidic electrochemical sensing.

PubMed

Sameenoi, Yupaporn; Mensack, Meghan M; Boonsong, Kanokporn; Ewing, Rebecca; Dungchai, Wijitar; Chailapakul, Orawan; Cropek, Donald M; Henry, Charles S

2011-08-07

Recently, the development of electrochemical biosensors as part of microfluidic devices has garnered a great deal of attention because of the small instrument size and portability afforded by the integration of electrochemistry in microfluidic systems. Electrode fabrication, however, has proven to be a major obstacle in the field. Here, an alternative method to create integrated, low cost, robust, patternable carbon paste electrodes (CPEs) for microfluidic devices is presented. The new CPEs are composed of graphite powder and a binder consisting of a mixture of poly(dimethylsiloxane) (PDMS) and mineral oil. The electrodes are made by filling channels molded in previously cross-linked PDMS using a method analogous to screen printing. The optimal binder composition was investigated to obtain electrodes that were physically robust and performed well electrochemically. After studying the basic electrochemistry, the PDMS-oil CPEs were modified with multi-walled carbon nanotubes (MWCNT) and cobalt phthalocyanine (CoPC) for the detection of catecholamines and thiols, respectively, to demonstrate the ease of electrode chemical modification. Significant improvement of analyte signal detection was observed from both types of modified CPEs. A nearly 2-fold improvement in the electrochemical signal for 100 μM dithiothreitol (DTT) was observed when using a CoPC modified electrode (4.0 ± 0.2 nA (n = 3) versus 2.5 ± 0.2 nA (n = 3)). The improvement in signal was even more pronounced when looking at catecholamines, namely dopamine, using MWCNT modified CPEs. In this case, an order of magnitude improvement in limit of detection was observed for dopamine when using the MWCNT modified CPEs (50 nM versus 500 nM). CoPC modified CPEs were successfully used to detect thiols in red blood cell lysate while MWCNT modified CPEs were used to monitor temporal changes in catecholamine release from PC12 cells following stimulation with potassium.

Electrokinetic In Situ Treatment of Metal-Contaminated Soil

NASA Technical Reports Server (NTRS)

Quinn, Jacqueline; Clausen, Christian A., III; Geiger, Cherie; Reinhart, Debra

2004-01-01

An electrokinetic technique has been developed as a means of in situ remediation of soils, sludges, and sediments that are contaminated with heavy metals. Examples of common metal contaminants that can be removed by this technique include cadmium, chromium, zinc, lead, mercury, and radionuclides. Some organic contaminants can also be removed by this technique. In the electrokinetic technique, a low-intensity direct current is applied between electrodes that have been implanted in the ground on each side of a contaminated soil mass. The electric current causes electro-osmosis and migration of ions, thereby moving aqueous-phase subsurface contaminants from one electrode to the other. The half reaction at the anode yields H+, thereby generating an acid front that travels from the anode toward the cathode. As this acid front passes through a given location, the local increase in acidity increases the solubility of cations that were previously adsorbed on soil particles. Ions are transported towards one electrode or the other which one depending on their respective electric charges. Upon arrival at the electrodes, the ionic contaminants can be allowed to become deposited on the electrodes or can be extracted to a recovery system. Surfactants and other reagents can be introduced at the electrodes to enhance rates of removal of contaminants. Placements of electrodes and concentrations and rates of pumping of reagents can be adjusted to maximize efficiency. The basic concept of electrokinetic treatment of soil is not new. What is new here are some of the details of application and the utilization of this technique as an alternative to other techniques (e.g., flushing or bioremediation) that are not suitable for treating soils of low hydraulic conductivity. Another novel aspect is the use of this technique as a less expensive alternative to excavation: The cost advantage over excavation is especially large in settings in which contaminated soil lies near and/or under industrial buildings and therefore excavation would be made even more expensive by the need to prevent damage to numerous underground pipes and cables.

Status of commercial phosphoric acid fuel cell system development

NASA Technical Reports Server (NTRS)

Warshay, M.; Prokopius, P. R.; Simons, S. N.; King, R. B.

1981-01-01

In both the electric utility and onsite integrated energy system applications, reducing cost and increasing reliability are the main technology drivers. The longstanding barrier to the attainment of these goals, which manifests itself in a number of ways, was materials. The differences in approach among the three major participants (United Technologies Corporation, Westinghouse Electric Corporation/Energy Research Corporation, and Engelhard Industries) and their unique technological features, including electrodes, matrices, intercell cooling, bipolar/separator plates, electrolyte management, fuel selection and system design philosophy are discussed.

Cost and Performance Report: Introduction and Validation of Chromium-Free Consumables for Welding Stainless Steels. Version 2

DTIC Science & Technology

2015-04-01

hexavalent chromium in the welding fume of stainless steel . Welds of both Cr-free consumables met the performance objectives of 70,000 pounds per square...hexavalent chromium (Cr(VI)) in the welding fume of stainless steel . This project was developed in two stages: laboratory demonstration and field...consumables they are designed to replace. The measured Cr(VI) in the fume of the SMAW electrode when welding Type 304 stainless steel is virtually zero

Carbon nanotube/metal-sulfide composite flexible electrodes for high-performance quantum dot-sensitized solar cells and supercapacitors

NASA Astrophysics Data System (ADS)

Muralee Gopi, Chandu V. V.; Ravi, Seenu; Rao, S. Srinivasa; Eswar Reddy, Araveeti; Kim, Hee-Je

2017-04-01

Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg-1 and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices.

Carbon nanotube/metal-sulfide composite flexible electrodes for high-performance quantum dot-sensitized solar cells and supercapacitors.

PubMed

Muralee Gopi, Chandu V V; Ravi, Seenu; Rao, S Srinivasa; Eswar Reddy, Araveeti; Kim, Hee-Je

2017-04-19

Carbon nanotubes (CNT) and metal sulfides have attracted considerable attention owing to their outstanding properties and multiple application areas, such as electrochemical energy conversion and energy storage. Here we describes a cost-effective and facile solution approach to the preparation of metal sulfides (PbS, CuS, CoS, and NiS) grown directly on CNTs, such as CNT/PbS, CNT/CuS, CNT/CoS, and CNT/NiS flexible electrodes for quantum dot-sensitized solar cells (QDSSCs) and supercapacitors (SCs). X-ray photoelectron spectroscopy, X-ray diffraction, and transmission electron microscopy confirmed that the CNT network was covered with high-purity metal sulfide compounds. QDSSCs equipped with the CNT/NiS counter electrode (CE) showed an impressive energy conversion efficiency (η) of 6.41% and remarkable stability. Interestingly, the assembled symmetric CNT/NiS-based polysulfide SC device exhibited a maximal energy density of 35.39 W h kg -1 and superior cycling durability with 98.39% retention after 1,000 cycles compared to the other CNT/metal-sulfides. The elevated performance of the composites was attributed mainly to the good conductivity, high surface area with mesoporous structures and stability of the CNTs and the high electrocatalytic activity of the metal sulfides. Overall, the designed composite CNT/metal-sulfide electrodes offer an important guideline for the development of next level energy conversion and energy storage devices.

Biosensing of glucose in flow injection analysis system based on glucose oxidase-quantum dot modified pencil graphite electrode.

PubMed

Sağlam, Özlem; Kızılkaya, Bayram; Uysal, Hüseyin; Dilgin, Yusuf

2016-01-15

A novel amperometric glucose biosensor was proposed in flow injection analysis (FIA) system using glucose oxidase (GOD) and Quantum dot (ZnS-CdS) modified Pencil Graphite Electrode (PGE). After ZnS-CdS film was electrochemically deposited onto PGE surface, GOD was immobilized on the surface of ZnS-CdS/PGE through crosslinking with chitosan (CT). A pair of well-defined reversible redox peak of GOD was observed at GOD/CT/ZnS-CdS/PGE based on enzyme electrode by direct electron transfer between the protein and electrode. Further, obtained GOD/CT/ZnS-CdS/PGE offers a disposable, low cost, selective and sensitive electrochemical biosensing of glucose in FIA system based on the decrease of the electrocatalytic response of the reduced form of GOD to dissolved oxygen. Under optimum conditions (flow rate, 1.3mL min(-1); transmission tubing length, 10cm; injection volume, 100μL; and constant applied potential, -500mV vs. Ag/AgCl), the proposed method displayed a linear response to glucose in the range of 0.01-1.0mM with detection limit of 3.0µM. The results obtained from this study would provide the basis for further development of the biosensing using PGE based FIA systems. Copyright © 2015 Elsevier B.V. All rights reserved.

A polymeric liquid membrane electrode responsive to 3,3',5,5'-tetramethylbenzidine oxidation for sensitive peroxidase/peroxidase mimetic-based potentiometric biosensing.

PubMed

Wang, Xuewei; Yang, Yangang; Li, Long; Sun, Mingshuang; Yin, Haogen; Qin, Wei

2014-05-06

The oxidation of 3,3',5,5'-tetramethylbenzidine (TMB) has great utility in bioanalysis such as peroxidase/peroxidase mimetic-based biosensing. In this paper, the behaviors of TMB oxidation intermediates/products in liquid/liquid biphasic systems have been investigated for the first time. The free radical, charge transfer complex, and diimine species generated by TMB oxidation are all positively charged under acidic and near-neutral conditions. Electron paramagnetic resonance and visible absorbance spectroscopy data demonstrate that these cationic species can be effectively transferred from an aqueous phase into a water-immiscible liquid phase functionalized by an appropriate cation exchanger. Accordingly, sensitive potential responses of TMB oxidation have been obtained on a cation exchanger-doped polymeric liquid membrane electrode under mildly acidic and near-neutral conditions. By using the membrane electrode responsive to TMB oxidations, two sensitive potentiometric biosensing schemes including the peroxidase-labeled sandwich immunoassay and G-quadruplex DNAzyme-based DNA hybridization assay have been developed. The obtained detection limits for the target antigen and DNA are 0.02 ng/mL and 0.1 nM, respectively. Coupled with other advantages such as low cost, high reliability, and ease of miniaturization and integration, the proposed polymeric liquid membrane electrode holds great promise as a facile and efficient transducer for TMB oxidation and related biosensing applications.

Assembling a supercapacitor electrode with dual metal oxides and activated carbon using a liquid phase plasma.

PubMed

Ki, Seo Jin; Jeon, Ki-Joon; Park, Young-Kwon; Park, Hyunwoong; Jeong, Sangmin; Lee, Heon; Jung, Sang-Chul

2017-12-01

Developing supercapacitor electrodes at an affordable cost while improving their energy and/or power density values is still a challenging task. This study introduced a recipe which assembled a novel electrode composite using a liquid phase plasma that was applied to a reactant solution containing an activated carbon (AC) powder with dual metal precursors of iron and manganese. A comparison was made between the composites doped with single and dual metal components as well as among those synthesized under different precursor concentrations and plasma durations. The results showed that increasing the precursor concentration and plasma duration raised the content of both metal oxides in the composites, whereas the deposition conditions were more favorable to iron oxide than manganese oxide, due to its higher standard potential. The composite treated with the longest plasma duration and highest manganese concentration was superior to the others in terms of cyclic stability and equivalent series resistance. In addition, the new composite selected out of them showed better electrochemical performance than the raw AC material only and even two types of single metal-based composites, owing largely to the synergistic effect of the two metal oxides. Therefore, the proposed methodology can be used to modify existing and future composite electrodes to improve their performance with relatively cheap host and guest materials. Copyright © 2017 Elsevier Ltd. All rights reserved.

Design and synthesis of polymer, carbon and composite electrodes for high energy and high power supercapacitors

NASA Astrophysics Data System (ADS)

Arcila Velez, Margarita Rosa

Supercapacitors (SCs) are promising energy storage devices because they deliver energy faster than Li-ion batteries and store larger amounts of charge compared to dielectric capacitors. SCs are classified in electrical double layer capacitors (EDLCs) and pseudocapacitors, based on their charge storage mechanism. EDLCs store charge electrostatically, i.e. by physical charge separation. This mechanism limits the storable amount of energy to the available surface area of the electrode, typically made of carbon materials, but grants good cycling stability of the SC device. Pseudocapacitor electrodes, commonly made of conducting polymers or metal oxides, store charge faradaically, i.e. through redox reactions throughout the bulk material, which allows them to store significantly larger amounts of energy than EDLCs, but their stability is compromised due to the partial irreversibility of the faradaic processes. To accomplish the commercialization of SCs, devices must show a combination of high charge storage capacities and long-term stability, besides being cost-effective. To tackle the current issues of SCs, this field of study has taken mainly two directions: 1) the development of new architectures and nanostructures of the active materials, which has shown to increase the surface area, enhance stability, and facilitate ion diffusion; and 2) fabrication of composites between non-faradaic (carbon), faradaic materials, and/or redox-active components to achieve a balance between the amount of energy stored and the stability. Following the first approach, a continuous process to grow vertically aligned carbon nanotubes (VACNTs) on cost-effective aluminum foil was developed. The resulting electrodes were analyzed as SC electrodes and in symmetric cells, and the influence of the arrangement of the nanotubes and the synthesis conditions was studied. The performance of the VACNTs produced continuously showed similar performance to the VACNTs produced stationarily and the ordered structure of the VACNTs showed superior performance compared to randomly oriented CNTs. To increase the energy density, the second approach was taken, by combining pre-synthesized conducting polymers (CPs) and carbon nanotubes (CNTs) using a facile scalable dispersion filtration method to produce free-standing electrodes. Composites with the three main CPs were prepared, analyzed in various electrolytes, and their performance was comparable with polymer/ CNT films prepared with more complex techniques such as in-situ polymerization and pellet pressing. Then, based on the idea that the quinone molecules present in lignin store charge by undergoing a 2 proton, 2 electron redox reaction, a composite between polypyrrole, a stable conducting polymer, and the prototypical molecule p-benzoquinone was fabricated by electropolymerization of pyrrole in the presence of the redox molecule. A significant increase in capacitance and capacity was obtained with respect to polypyrrole films. Furthermore, an important obstacle in the application of CPs in SCs is the lack of easily reduced (n-dopable) polymers. Poly(aminoanthraquinone) (PAQ) is a conjugated polymer that shows electroactivity in the negative potential range of 0 to -2 V, due to the redox moieties of the polymer. PAQ was electropolymerized on free-standing CNT films and its performance as anode for SCs was studied. The materials and processing techniques described in this dissertation are useful to further develop high power/high energy electrodes for SCs.

Electrolytic trichloroethene degradation using mixed metal oxide coated titanium mesh electrodes.

PubMed

Petersen, Matthew A; Sale, Thomas C; Reardon, Kenneth F

2007-04-01

Electrochemical systems provide a low cost, versatile, and controllable platform to potentially treat contaminants in water, including chlorinated solvents. Relative to bare metal or noble metal amended materials, dimensionally stable electrode materials such as mixed metal oxide coated titanium (Ti/MMO) have advantages in terms of stability and cost, important factors for sustainable remediation solutions. Here, we report the use of Ti/MMO as an effective cathode substrate for treatment of trichloroethene (TCE). TCE degradation in a batch reactor was measured as the decrease of TCE concentration over time and the corresponding evolution of chloride; notably, this occurred without the formation of commonly encountered chlorinated intermediates. The reaction was initiated when Ti/MMO cathode potentials were less than -0.8 V vs. the standard hydrogen electrode, and the rate of TCE degradation increased linearly with progressively more negative potentials. The maximum pseudo-first-order heterogeneous rate constant was approximately 0.05 cm min(-1), which is comparable to more commonly used cathode materials such as nickel. In laboratory-scale flow-though column reactors designed to simulate permeable reactive barriers (PRBs), TCE concentrations were reduced by 80-90%. The extent of TCE flux reduction increased with the applied potential difference across the electrodes and was largely insensitive to the spacing distance between the electrodes. This is the first report of the electrochemical reduction of a chlorinated organic contaminant at a Ti/MMO cathode, and these results support the use of this material in PRBs as a possible approach to manage TCE plume migration.

Design and Development of Intelligent Electrodes for Future Digital Health Monitoring: A Review

NASA Astrophysics Data System (ADS)

Khairuddin, A. M.; Azir, K. N. F. Ku; Kan, P. Eh

2018-03-01

Electrodes are sensors used in electrocardiography (ECG) monitoring system to diagnose heart diseases. Over the years, diverse types of electrodes have been designed and developed to improve ECG monitoring system. However, more recently, with the technological advances and capabilities from the Internet of Things (IoT), cloud computing and data analytics in personalized healthcare, researchers are attempting to design and develop more effective as well as flexible ECG devices by using intelligent electrodes. This paper reviews previous works on electrodes used in electrocardiography (ECG) monitoring devices to identify the key ftures for designing and developing intelligent electrodes in digital health monitoring devices.

Modeling, design, packing and experimental analysis of liquid-phase shear-horizontal surface acoustic wave sensors

NASA Astrophysics Data System (ADS)

Pollard, Thomas B

Recent advances in microbiology, computational capabilities, and microelectromechanical-system fabrication techniques permit modeling, design, and fabrication of low-cost, miniature, sensitive and selective liquid-phase sensors and lab-on-a-chip systems. Such devices are expected to replace expensive, time-consuming, and bulky laboratory-based testing equipment. Potential applications for devices include: fluid characterization for material science and industry; chemical analysis in medicine and pharmacology; study of biological processes; food analysis; chemical kinetics analysis; and environmental monitoring. When combined with liquid-phase packaging, sensors based on surface-acoustic-wave (SAW) technology are considered strong candidates. For this reason such devices are focused on in this work; emphasis placed on device modeling and packaging for liquid-phase operation. Regarding modeling, topics considered include mode excitation efficiency of transducers; mode sensitivity based on guiding structure materials/geometries; and use of new piezoelectric materials. On packaging, topics considered include package interfacing with SAW devices, and minimization of packaging effects on device performance. In this work novel numerical models are theoretically developed and implemented to study propagation and transduction characteristics of sensor designs using wave/constitutive equations, Green's functions, and boundary/finite element methods. Using developed simulation tools that consider finite-thickness of all device electrodes, transduction efficiency for SAW transducers with neighboring uniform or periodic guiding electrodes is reported for the first time. Results indicate finite electrode thickness strongly affects efficiency. Using dense electrodes, efficiency is shown to approach 92% and 100% for uniform and periodic electrode guiding, respectively; yielding improved sensor detection limits. A numerical sensitivity analysis is presented targeting viscosity using uniform-electrode and shear-horizontal mode configurations on potassium-niobate, langasite, and quartz substrates. Optimum configurations are determined yielding maximum sensitivity. Results show mode propagation-loss and sensitivity to viscosity are correlated by a factor independent of substrate material. The analysis is useful for designing devices meeting sensitivity and signal level requirements. A novel, rapid and precise microfluidic chamber alignment/bonding method was developed for SAW platforms. The package is shown to have little effect on device performance and permits simple macrofluidic interfacing. Lastly, prototypes were designed, fabricated, and tested for viscosity and biosensor applications; results show ability to detect as low as 1% glycerol in water and surface-bound DNA crosslinking.

Silver Nanowire Transparent Conductive Electrodes for High-Efficiency III-Nitride Light-Emitting Diodes

PubMed Central

Oh, Munsik; Jin, Won-Yong; Jun Jeong, Hyeon; Jeong, Mun Seok; Kang, Jae-Wook; Kim, Hyunsoo

2015-01-01

Silver nanowires (AgNWs) have been successfully demonstrated to function as next-generation transparent conductive electrodes (TCEs) in organic semiconductor devices owing to their figures of merit, including high optical transmittance, low sheet resistance, flexibility, and low-cost processing. In this article, high-quality, solution-processed AgNWs with an excellent optical transmittance of 96.5% at 450 nm and a low sheet resistance of 11.7 Ω/sq were demonstrated as TCEs in inorganic III-nitride LEDs. The transmission line model applied to the AgNW contact to p-GaN showed that near ohmic contact with a specific contact resistance of ~10−3 Ωcm2 was obtained. The contact resistance had a strong bias-voltage (or current-density) dependence: namely, field-enhanced ohmic contact. LEDs fabricated with AgNW electrodes exhibited a 56% reduction in series resistance, 56.5% brighter output power, a 67.5% reduction in efficiency droop, and a approximately 30% longer current spreading length compared to LEDs fabricated with reference TCEs. In addition to the cost reduction, the observed improvements in device performance suggest that the AgNWs are promising for application as next-generation TCEs, to realise brighter, larger-area, cost-competitive inorganic III-nitride light emitters. PMID:26333768

Development of a novel and cost-effective redox sensor for voltammetric determination of pantoprazole sodium during pharmacokinetic studies

PubMed Central

Khashaba, Pakinaz Y.; Ali, Hassan Refat H.

2017-01-01

A pencil graphite electrode modified with poly (bromocresol green (BCG)) was prepared by electro-polymerization process for the determination of pantoprazole sodium. The surface morphology and structure of poly (BCG) film were characterized by scanning electron microscopy and Fourier transform infrared spectroscopy. The determination of pantoprazole sodium in Britton–Robinson buffer (pH 7.0) was carried out by square wave adsorptive stripping voltammetric technique. Under optimum conditions, the linear response of the peak with concentration of the cited drug was in the range of 6.6–360 × 10−8 M with limit of detection of 2.2 × 10−8 M. Moreover, the poly (BCG)-modified electrode has been successfully applied to determine pantoprazole sodium in tablets, vials and during pharmacokinetic studies. PMID:28878983

Nanomaterial-based electrochemical sensors for arsenic - A review.

PubMed

Kempahanumakkagari, Sureshkumar; Deep, Akash; Kim, Ki-Hyun; Kumar Kailasa, Suresh; Yoon, Hye-On

2017-09-15

The existence of arsenic in the environment poses severe global health threats. Considering its toxicity, the sensing of arsenic is extremely important. Due to the complexity of environmental and biological samples, many of the available detection methods for arsenic have serious limitations on selectivity and sensitivity. To improve sensitivity and selectivity and to circumvent interferences, different electrode systems have been developed based on surface modification with nanomaterials including carbonaceous nanomaterials, metallic nanoparticles (MNPs), metal nanotubes (MNTs), and even enzymes. Despite the progress made in electrochemical sensing of arsenic, some issues still need to be addressed to realize cost effective, portable, and flow-injection type sensor systems. The present review provides an in-depth evaluation of the nanoparticle-modified electrode (NME) based methods for the electrochemical sensing of arsenic. NME based sensing systems are projected to become an important option for monitoring hazardous pollutants in both environmental and biological media. Copyright © 2017 Elsevier B.V. All rights reserved.

Emerging Semitransparent Solar Cells: Materials and Device Design.

PubMed

Tai, Qidong; Yan, Feng

2017-09-01

Semitransparent solar cells can provide not only efficient power-generation but also appealing images and show promising applications in building integrated photovoltaics, wearable electronics, photovoltaic vehicles and so forth in the future. Such devices have been successfully realized by incorporating transparent electrodes in new generation low-cost solar cells, including organic solar cells (OSCs), dye-sensitized solar cells (DSCs) and organometal halide perovskite solar cells (PSCs). In this review, the advances in the preparation of semitransparent OSCs, DSCs, and PSCs are summarized, focusing on the top transparent electrode materials and device designs, which are all crucial to the performance of these devices. Techniques for optimizing the efficiency, color and transparency of the devices are addressed in detail. Finally, a summary of the research field and an outlook into the future development in this area are provided. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

From Lithium-Ion to Sodium-Ion Batteries: Advantages, Challenges, and Surprises.

PubMed

Nayak, Prasant Kumar; Yang, Liangtao; Brehm, Wolfgang; Adelhelm, Philipp

2018-01-02

Mobile and stationary energy storage by rechargeable batteries is a topic of broad societal and economical relevance. Lithium-ion battery (LIB) technology is at the forefront of the development, but a massively growing market will likely put severe pressure on resources and supply chains. Recently, sodium-ion batteries (SIBs) have been reconsidered with the aim of providing a lower-cost alternative that is less susceptible to resource and supply risks. On paper, the replacement of lithium by sodium in a battery seems straightforward at first, but unpredictable surprises are often found in practice. What happens when replacing lithium by sodium in electrode reactions? This review provides a state-of-the art overview on the redox behavior of materials when used as electrodes in lithium-ion and sodium-ion batteries, respectively. Advantages and challenges related to the use of sodium instead of lithium are discussed. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

PEMFC MEA and System Design Considerations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Knights, Shanna; Bashyam, Rajesh; He, Ping

2011-07-01

Proton exchange membrane fuel cells (PEMFCs) are being developed and sold commercially for multiple near term markets. Ballard Power Systems is focused on the near term markets of backup power, distributed generation, materials handling, and buses. Significant advances have been made in cost and durability of fuel cell products. Improved tolerance to a wide range of system operation and environmental noises will enable increased viability across a broad range of applications. In order to apply the most effective membrane electrode assembly (MEA) design for each market, the system requirements and associated MEA failures must be well understood. The failure modesmore » associated with the electrodes and membrane degradation are discussed with respect to associated system operation and mitigating approaches. A few key system considerations that influence MEA design include expected fuel quality, balance-of-plant materials, time under idle or open circuit operation, and start-up and shut-down conditions.« less

Single-Step Reagentless Laser Scribing Fabrication of Electrochemical Paper-Based Analytical Devices.

PubMed

de Araujo, William R; Frasson, Carolina M R; Ameku, Wilson A; Silva, José R; Angnes, Lúcio; Paixão, Thiago R L C

2017-11-20

A single-step laser scribing process is used to pattern nanostructured electrodes on paper-based devices. The facile and low-cost technique eliminates the need for chemical reagents or controlled conditions. This process involves the use of a CO 2 laser to pyrolyze the surface of the paperboard, producing a conductive porous non-graphitizing carbon material composed of graphene sheets and composites with aluminosilicate nanoparticles. The new electrode material was extensively characterized, and it exhibits high conductivity and an enhanced active/geometric area ratio; it is thus well-suited for electrochemical purposes. As a proof-of-concept, the devices were successfully employed for different analytical applications in the clinical, pharmaceutical, food, and forensic fields. The scalable and green fabrication method associated with the features of the new material is highly promising for the development of portable electrochemical devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Tetra-heteroatom self-doped carbon nanosheets derived from silkworm excrement for high-performance supercapacitors

NASA Astrophysics Data System (ADS)

Lei, Shuijin; Chen, Lianfu; Zhou, Wei; Deng, Peiqin; Liu, Yan; Fei, Linfeng; Lu, Wei; Xiao, Yanhe; Cheng, Baochang

2018-03-01

Carbon materials are deemed to be competitive candidate electrode materials for energy storage systems. It is still a great challenge to explore advanced carbon-based electrode materials for high-performance supercapacitors by a facile, economical and efficient method. In this work, N-, P-, S-, O-self-doped carbon nanosheets with high surface area and well-developed porosity are successfully prepared by pyrolysis carbonization and post KOH activation from silkworm excrement, a novel abundant, low-cost and eco-friendly agricultural waste. Thanks to their unique multi-heteroatom doping and porous structure, the obtained carbon materials exhibit high charge storage capacity with a specific capacitance of 401 F g-1 at a current density of 0.5 A g-1 in 6 M KOH and good cycling stability with a capacitance retention of 93.8% over 10000 cycles. A symmetric supercapacitor device using 1 M Na2SO4 aqueous solution as the electrolyte can deliver a specific capacitance of 41.7 F g-1 at a current density of 0.5 A g-1, and a high energy density of 23.17 Wh kg-1 at a power density of 500 W kg-1 with a wide voltage window of 2.0 V. This work develops a new strategy to produce favorable carbon-based electrode materials for supercapacitors with high electrochemical performances.

Stretchable Lithium-Ion Batteries Enabled by Device-Scaled Wavy Structure and Elastic-Sticky Separator

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liu, Wei; Chen, Jun; Chen, Zheng

Fast developments and substantial achievements have been shaping the field of wearable electronic devices, resulting in the persistent requirement for stretchable lithium-ion batteries (LIBs). Despite recent progress in stretchable electrodes, stretching full batteries, including electrodes, separator, and sealing material, remains a great challenge. Here, a simple design concept for stretchable LIBs via a wavy structure at the full battery device scale is reported. All components including the package are capable of being reversibly stretched by folding the entire pouch cell into a wavy shape with polydimethylsiloxane filled in each valley region. In addition, the stretchable, sticky, and porous polyurethane/poly(vinylidene fluoride)more » membrane is adopted as a separator for the first time, which can maintain intimate contact between electrodes and separator to continuously secure ion pathway under dynamic state. Commercial cathode, anode, and package can be utilized in this rationally designed wavy battery to enable stretchability. The results indicate good electrochemical performances and long-term stability at repeatable release–stretch cycles. A high areal capacity of 3.6 mA h cm -2 and energy density of up to 172 W h L -1 can be achieved for the wavy battery. The promising results of the cost-effective wavy battery with high stretchability shed light on the development of stretchable energy storages.« less

Stretchable Lithium-Ion Batteries Enabled by Device-Scaled Wavy Structure and Elastic-Sticky Separator

DOE PAGES

Liu, Wei; Chen, Jun; Chen, Zheng; ...

2017-07-17

Fast developments and substantial achievements have been shaping the field of wearable electronic devices, resulting in the persistent requirement for stretchable lithium-ion batteries (LIBs). Despite recent progress in stretchable electrodes, stretching full batteries, including electrodes, separator, and sealing material, remains a great challenge. Here, a simple design concept for stretchable LIBs via a wavy structure at the full battery device scale is reported. All components including the package are capable of being reversibly stretched by folding the entire pouch cell into a wavy shape with polydimethylsiloxane filled in each valley region. In addition, the stretchable, sticky, and porous polyurethane/poly(vinylidene fluoride)more » membrane is adopted as a separator for the first time, which can maintain intimate contact between electrodes and separator to continuously secure ion pathway under dynamic state. Commercial cathode, anode, and package can be utilized in this rationally designed wavy battery to enable stretchability. The results indicate good electrochemical performances and long-term stability at repeatable release–stretch cycles. A high areal capacity of 3.6 mA h cm -2 and energy density of up to 172 W h L -1 can be achieved for the wavy battery. The promising results of the cost-effective wavy battery with high stretchability shed light on the development of stretchable energy storages.« less

Synthesizing Porous NaTi2(PO4)3 Nanoparticles Embedded in 3D Graphene Networks for High-Rate and Long Cycle-Life Sodium Electrodes.

PubMed

Wu, Chao; Kopold, Peter; Ding, Yuan-Li; van Aken, Peter A; Maier, Joachim; Yu, Yan

2015-06-23

Sodium ion batteries attract increasing attention for large-scale energy storage as a promising alternative to the lithium counterparts in view of low cost and abundant sodium source. However, the large ion radius of Na brings about a series of challenging thermodynamic and kinetic difficulties to the electrodes for sodium-storage, including low reversible capacity and low ion transport, as well as large volume change. To mitigate or even overcome the kinetic problems, we develop a self-assembly route to a novel architecture consisting of nanosized porous NASICON-type NaTi2(PO4)3 particles embedded in microsized 3D graphene network. Such architecture synergistically combines the advantages of a 3D graphene network and of 0D porous nanoparticles. It greatly increases the electron/ion transport kinetics and assures the electrode structure integrity, leading to attractive electrochemical performance as reflected by a high rate-capability (112 mAh g(-1) at 1C, 105 mAh g(-1) at 5C, 96 mAh g(-1) at 10C, 67 mAh g(-1) at 50C), a long cycle-life (capacity retention of 80% after 1000 cycles at 10C), and a high initial Coulombic efficiency (>79%). This nanostructure design provides a promising pathway for developing high performance NASICON-type materials for sodium storage.

A comparative Study of Aptasensor Vs Immunosensor for Label-Free PSA Cancer Detection on GQDs-AuNRs Modified Screen-Printed Electrodes.

PubMed

Srivastava, Monika; Nirala, Narsingh R; Srivastava, S K; Prakash, Rajiv

2018-01-31

Label-free and sensitive detection of PSA (Prostate Specific Antigen) is still a big challenge in the arena of prostate cancer diagnosis in males. We present a comparative study for label-free PSA aptasensor and PSA immunosensor for the PSA-specific monoclonal antibody, based on graphene quantum dots-gold nanorods (GQDs-AuNRs) modified screen-printed electrodes. GQDs-AuNRs composite has been synthesized and used as an electro-active material, which shows fast electron transfer and catalytic property. Aptamer or anti-PSA has immobilized onto the surface of modified screen printed electrodes. Three techniques are used simultaneously, viz. cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedence spectroscopy (EIS) to investigate the analytical performance of both PSA aptasensor and PSA immunosensor with its corresponding PSA antigen. Under optimum conditions, both sensors show comparable results with an almost same limit of detection (LOD) of 0.14 ng mL -1 . The results developed with aptasensor and anti-PSA is also checked through the detection of PSA in real samples with acceptable results. Our study suggests some advantages of aptasensor in terms of better stability, simplicity and cost effectiveness. Further our present work shows enormous potential of our developed sensors for real application using voltammetric and EIS techniques simultaneous to get reliable detection of the disease.

Improved low-cost, non-hazardous, all-iron cell for the developing world

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated in this paper. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade aftermore » a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm -2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US$0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. Finally, we anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.« less

Improved low-cost, non-hazardous, all-iron cell for the developing world

DOE PAGES

Tucker, Michael C.; Lambelet, David; Oueslati, Mohamed; ...

2016-09-28

A low-cost, non-hazardous personal-power system based on an aqueous all-iron electrochemical cell is demonstrated in this paper. The system is intended to be assembled and operated by developing-world households that lack sufficient access to electricity, thereby enabling LED lighting or mobile phone charging on demand. Lab-scale hardware is used to assess the performance of individual cell components. It is found that coffee filter paper is an effective low-cost separator. Carbon felt is a low-cost electrode material, and its performance and wetting by the electrolyte solution is greatly improved by pre-treatment with sulfuric acid. The carbon felt does not degrade aftermore » a week of daily use. By using these components, performance of the system is significantly improved over the previous baseline, with power density more than doubling to 40 mW cm -2, and iron utilization improving from 78% to 88%. The operating cost is estimated to be less than US$0.03 per mobile phone charge. Based on the lab-scale results, a stand-alone prototype consumer product is designed, fabricated, and tested. It successfully provides 2.5 h of LED illumination while consuming 200 mL of electrolyte solution via gravity feed. Finally, we anticipate these results will enable deployment of this innovative system to energy-impoverished individuals in the developing world.« less

Use of the sulfide mineral pyrite as electrochemical sensor in non-aqueous solutions: potentiometric titration of weak acids in acetonitrile, propionitrile and benzonitrile.

PubMed

Mihajlović, Ljiljana; Nikolić-Mandić, Snezana; Vukanović, Branislav; Mihajlović, Randel

2009-03-01

Natural monocrystalline pyrite as a new indicator electrode for the potentiometric titration of weak acids in acetonitrile, propionitrile and benzonitrile was studied. The investigated electrode showed a linear dynamic response for p-toluenesulfonic acid concentrations in the range from 0.1 to 0.001 M, with a Nernstian slope of 74 mV per decade. Sodium methylate, potassium hydroxide and tetrabutylammonium hydroxide (TBAH) proved to be very suitable titrating agent for this titration. The response time was less than (11 s) and the lifetime of the electrode is long. The advantages of the electrode are log-term stability, fast response, and reproducibility, while the sensor is easy to prepare and of low cost.

Demonstration of organic volatile decomposition and bacterial sterilization by miniature dielectric barrier discharges on low-temperature cofired ceramic electrodes

NASA Astrophysics Data System (ADS)

Kim, Duk-jae; Shim, Yeun-keun; Park, Jeongwon; Kim, Hyung-jun; Han, Jeon-geon

2016-04-01

Nonthermal atmospheric-pressure plasma discharge is designed with low-temperature cofired ceramic (LTCC) electrodes to achieve dielectric barrier surface discharge (DBSD). The environmental requirement (below 0.05 ppm) of the amount of byproducts (ozone and NO x ) produced during the process was met by optimizing the electrode design to produce a high dielectric barrier discharge for low-voltage (∼700 V) operation and minimizing the distance between electrodes to improve the plasma discharging efficiency. The concentrations of volatile organic compounds (VOCs) within interior cabins of commercial vehicles were significantly reduced after 1-h treatment to improve air quality cost-effectively. This atmospheric-pressure plasma process was demonstrated for the sterilization of Escherichia coli to prevent food poisoning during the preservation of food in refrigerators.

High Performance of PEDOT:PSS/n-Si Solar Cells Based on Textured Surface with AgNWs Electrodes

NASA Astrophysics Data System (ADS)

Jiang, Xiangyu; Zhang, Pengbo; Zhang, Juan; Wang, Jilei; Li, Gaofei; Fang, Xiaohong; Yang, Liyou; Chen, Xiaoyuan

2018-02-01

Hybrid heterojunction solar cells (HHSCs) have gained extensive research and attention due to simple device structure and low-cost technological processes. Here, HHSCs are presented based on a highly transparent conductive polymer poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) directly spin-coated on an n-type crystalline silicon with microscale surface textures, which are prepared by traditional chemical etching. We have studied interface properties between PEDOT:PSS and textured n-Si by varying coating conditions. Final power conversion efficiency (PCE) could arrive at 8.54% by these simple solution-based fabrication processes. The high conversion efficiency is attributed to the fully conformal contact between PEDOT:PSS film and textured silicon. Furthermore, the reflectance of the PEDOT:PSS layer on textured surface is analyzed by changing film thickness. In order to improve the performance of the device, silver nanowires were employed as electrodes because of its better optical transmittance and electrical conductivity. The highest PCE of 11.07% was achieved which displayed a 29.6% enhancement compared with traditional silver electrodes. These findings imply that the combination of PEDOT:PSS film and silver nanowire transparent electrodes pave a promising way for realizing high-efficiency and low-cost solar cells.

High Performance of PEDOT:PSS/n-Si Solar Cells Based on Textured Surface with AgNWs Electrodes.

PubMed

Jiang, Xiangyu; Zhang, Pengbo; Zhang, Juan; Wang, Jilei; Li, Gaofei; Fang, Xiaohong; Yang, Liyou; Chen, Xiaoyuan

2018-02-14

Hybrid heterojunction solar cells (HHSCs) have gained extensive research and attention due to simple device structure and low-cost technological processes. Here, HHSCs are presented based on a highly transparent conductive polymer poly(3,4ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) directly spin-coated on an n-type crystalline silicon with microscale surface textures, which are prepared by traditional chemical etching. We have studied interface properties between PEDOT:PSS and textured n-Si by varying coating conditions. Final power conversion efficiency (PCE) could arrive at 8.54% by these simple solution-based fabrication processes. The high conversion efficiency is attributed to the fully conformal contact between PEDOT:PSS film and textured silicon. Furthermore, the reflectance of the PEDOT:PSS layer on textured surface is analyzed by changing film thickness. In order to improve the performance of the device, silver nanowires were employed as electrodes because of its better optical transmittance and electrical conductivity. The highest PCE of 11.07% was achieved which displayed a 29.6% enhancement compared with traditional silver electrodes. These findings imply that the combination of PEDOT:PSS film and silver nanowire transparent electrodes pave a promising way for realizing high-efficiency and low-cost solar cells.

Surface modification of amine-functionalised graphite for preparation of cobalt hexacyanoferrate (CoHCF)-modified electrode: an amperometric sensor for determination of butylated hydroxyanisole (BHA).

PubMed

Prabakar, S J Richard; Narayanan, S Sriman

2006-12-01

A cobalt hexacyanoferrate (CoHCF)-modified graphite paraffin wax composite electrode was prepared by a new approach. An amine-functionalised graphite powder was used for the fabrication of the electrode. A functionalised graphite paraffin wax composite electrode was prepared and the surface of the electrode was modified with a thin film of CoHCF. Various parameters that influence the electrochemical behaviour of the modified electrode were studied by varying the background electrolytes, scan rates and pH. The modified electrode showed good electrocatalytic activity towards the oxidation of butylated hydroxyanisole (BHA) under optimal conditions and showed a linear response over the range from 7.9 x 10(-7) to 1.9 x 10(-4) M of BHA with a correlation coefficient of 0.9988. The limit of detection was 1.9 x 10(-7) M. Electrocatalytic oxidation of BHA was effective at the modified electrode at a significantly reduced potential and at a broader pH range. The utility of the modified electrode as an amperometric sensor for the determination of BHA in flow systems was evaluated by carrying out hydrodynamic and chronoamperometric experiments. The modified electrode showed very good stability and a longer shelf life. The modified electrode was applied for the determination of BHA in spiked samples of chewing gum and edible sunflower oil. The advantage of this method is the ease of electrode fabrication, good stability, longer shelf life, low cost and its diverse application for BHA determination.

A cost- and time-saving strategy of spraying TiO2 self-cleaning coatings in tubular substrates by air cold plasma

NASA Astrophysics Data System (ADS)

Zhang, Lujie; Yu, Shuang; Wang, Kaile; Zhang, Jue; Fang, Jing

2017-11-01

In this study, using an atmospheric pressure air plasma jet generated by a dielectric barrier structure with hollow electrodes (HEDBS), we developed an ultrafast process for spraying TiO2 self-cleaning films inside tubular substrates. Importantly, SEM images showed that the TiO2 particles were dispersed evenly in the tubular substrates. Furthermore, Raman and XRD pattern indicated the anatase structure of the HEDBS-spayed TiO2 coating after heating at 270 °C. Further results of the self cleaning test suggested that the proposed cost- and time-saving HEDBS approach with air working gas could provide a feasible way for synthesizing thin TiO2 nanofilms.