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Sample records for carbon anode material

  1. Carbon Cryogel Silicon Composite Anode Materials for Lithium Ion Batteries

    NASA Technical Reports Server (NTRS)

    Woodworth James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 10 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-4,9 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  2. Improved carbon anode materials for lithium-ion cells

    SciTech Connect

    Flynn, J.; Marsh, C.

    1998-07-01

    Several carbon materials have been studied for suitability as anode materials in lithium-ion cells. Carbons that have been included in this evaluation are three grades of commercially available mesophase carbon microbeads (MCMB) 6-28, 10-28 and 25-28, two specially prepared mesophase fibers (Amoco), a foreign mesophase fiber and KS-15 graphite (Lonza). Differences in cycling behavior between the three types of MCMB material are shown. Data of full lithium-ion cells demonstrate the effect that the choice of carbon material has on the cell discharge voltage and capacity. Lithium reference electrode experiments in full cells (3.0--4.0Ah capacity), elucidate the dynamics under several charge/discharge regimes and provide a comparison between the performance of carbon fiber and graphite anode materials. These test results indicate that the fibers can be charged at significantly higher rates than graphite without showing polarization at the anode. Full and half cell data also demonstrates the high coulombic efficiencies of the mesophase materials and first cycle efficiencies as compared to graphite. A comparison of two mesophase materials with different textures in full cells under strenuous cycling conditions shows significant differences in capacity retention. SEM photos of fibers showing the different textures are also presented.

  3. Silicon Composite Anode Materials for Lithium Ion Batteries Based on Carbon Cryogels and Carbon Paper

    NASA Technical Reports Server (NTRS)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nanofoams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  4. Carbon Cryogel and Carbon Paper-Based Silicon Composite Anode Materials for Lithium-Ion Batteries

    NASA Technical Reports Server (NTRS)

    Woodworth, James; Baldwin, Richard; Bennett, William

    2010-01-01

    A variety of materials are under investigation for use as anode materials in lithium-ion batteries, of which, the most promising are those containing silicon. 6 One such material is a composite formed via the dispersion of silicon in a resorcinol-formaldehyde (RF) gel followed by pyrolysis. Two silicon-carbon composite materials, carbon microspheres and nanofoams produced from nano-phase silicon impregnated RF gel precursors have been synthesized and investigated. Carbon microspheres are produced by forming the silicon-containing RF gel into microspheres whereas carbon nano-foams are produced by impregnating carbon fiber paper with the silicon containing RF gel to create a free standing electrode. 1-5 Both materials have demonstrated their ability to function as anodes and utilize the silicon present in the material. Stable reversible capacities above 400 mAh/g for the bulk material and above 1000 mAh/g of Si have been observed.

  5. Carbon Materials Metal/Metal Oxide Nanoparticle Composite and Battery Anode Composed of the Same

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh (Inventor)

    2006-01-01

    A method of forming a composite material for use as an anode for a lithium-ion battery is disclosed. The steps include selecting a carbon material as a constituent part of the composite, chemically treating the selected carbon material to receive nanoparticles, incorporating nanoparticles into the chemically treated carbon material and removing surface nanoparticles from an outside surface of the carbon material with incorporated nanoparticles. A material making up the nanoparticles alloys with lithium.

  6. Superstructured Carbon Nanotube/Porous Silicon Hybrid Materials for Lithium-Ion Battery Anodes

    NASA Astrophysics Data System (ADS)

    Lee, Jun-Ki; Kang, Shin-Hyun; Choi, Sung-Min

    2015-03-01

    High energy Li-ion batteries (LIBs) are in great demand for electronics, electric-vehicles, and grid-scale energy storage. To further increase the energy and power densities of LIBs, Si anodes have been intensively explored due to their high capacity, and high abundance compared with traditional carbon anodes. However, the poor cycle-life caused by large volume expansion during charge/discharge process has been an impediment to its applications. Recently, superstructured Si materials were received attentions to solve above mentioned problem in excellent mechanical properties, large surface area, and fast Li and electron transportation aspects, but applying superstructures to anode is in early stage yet. Here, we synthesized superstructured carbon nanotubes (CNTs)/porous Si hybrid materials and its particular electrochemical properties will be presented. Department of Nuclear and Quantum Engineering

  7. Advanced carbon anode materials for lithium ion cells

    NASA Astrophysics Data System (ADS)

    Azuma, Hideto; Imoto, Hiroshi; Yamada, Shin'ichiro; Sekai, Koji

    Three kinds of carbon have been used for commercial cells: graphite, soft carbon and hard carbon. The difference in the structures of these three kinds of carbon is shown clearly using our new model for soft and hard carbon structure. The lithium-doped state of these three kinds of carbon is discussed using the new structural model and published 7Li NMR data. A large reversible capacity is demonstrated in the hard carbons derived from some vegetable fibers. Two mechanisms—one enhancing the adsorbing force of pseudo-metallic lithium atoms and one reducing the repulsion force between doped lithium atoms—which together produce a high reversible capacity, are explained.

  8. Carbonized textile with free-standing threads as an efficient anode material for bioelectrochemical systems

    NASA Astrophysics Data System (ADS)

    Wang, Zejie; Zheng, Zhiyong; Zheng, Suqi; Chen, Shuiliang; Zhao, Feng

    2015-08-01

    Efficiency of bioelectrochemical systems (BESs) is generally limited by the performance of bioanode, resulted from the nature of microbial electron transfer and the character of the anode substrate. In the present study, a 3D structured anode material is fabricated using a towel as precursor through high-temperature carbonization. The 3D electrode is resulted from freely standing threads, twisted by fibers with diameter at micrometer scale, on a woven textile substrate. The open structure provides easy accesses for microbial to attach on the fiber surface. Furthermore, the prepared materials possess a high capacitive character which is beneficial for electron storage and contributes to the performance of bioanode. When tested in BESs, the prepared material achieves a current density of 0.80 ± 0.06 mA cm-2, larger than conventional anodes, e.g. graphite felt (0.55 ± 0.01 mA cm-2), carbon cloth (0.06 ± 0.01 mA cm-2), and carbon mesh (0.02 ± 0.00 mA cm-2). The present study provides a novel 3D anode substrate that can effectively promote the performance of BESs.

  9. A novel mesoporous carbon-silica-titania nanocomposite as a high performance anode material in lithium ion batteries.

    PubMed

    Zhou, Yuanyuan; Kim, Younghun; Jo, Changshin; Lee, Jinwoo; Lee, Chul Wee; Yoon, Songhun

    2011-05-01

    An ordered mesoporous carbon-silica-titania material was prepared using the tetra-constituents co-assembly method. As regards its anode performance in lithium ion batteries, the composite material anode exhibited a high capacity (875 mAh g(-1)), a higher initial efficiency (56%) and an improved rate. PMID:21424009

  10. Mesoporous carbon -Cr2O3 composite as an anode material for lithium ion batteries

    SciTech Connect

    Guo, Bingkun; Chi, Miaofang; Sun, Xiao-Guang; Dai, Sheng

    2012-01-01

    Mesoporous carbon-Cr2O3 (M-C-Cr2O3) composite was prepared by co-assembly of in-situ formed phenolic resin, chromium precursor, and Pluronic block copolymer under acidic conditions, followed by carbonization at 750oC under Argon. The TEM results confirmed that the Cr2O3 nanoparticles, ranging from 10 to 20 nm, were well dispersed in the matrix of mesoporous carbon. The composite exhibited an initial reversible capacity of 710 mAh g-1 and good cycling stability, which is mainly due to the synergic effects of carbons within the composites, i.e. confining the crystal growth of Cr2O3 during the high temperature treatment step and buffering the volume change of Cr2O3 during the cycling step. This composite material is a promising anode material for lithium ion batteries.

  11. Carbon-Encapsulated Co3O4 Nanoparticles as Anode Materials with Super Lithium Storage Performance

    NASA Astrophysics Data System (ADS)

    Leng, Xuning; Wei, Sufeng; Jiang, Zhonghao; Lian, Jianshe; Wang, Guoyong; Jiang, Qing

    2015-11-01

    A high-performance anode material for lithium storage was successfully synthesized by glucose as carbon source and cobalt nitrate as Co3O4 precursor with the assistance of sodium chloride surface as a template to reduce the carbon sheet thickness. Ultrafine Co3O4 nanoparticles were homogeneously embedded in ultrathin porous graphitic carbon in this material. The carbon sheets, which have large specific surface area, high electronic conductivity, and outstanding mechanical flexibility, are very effective to keep the stability of Co3O4 nanoparticales which has a large capacity. As a consequence, a very high reversible capacity of up to 1413 mA h g-1 at a current density of 0.1 A g-1 after 100 cycles, a high rate capability (845, 560, 461 and 345 mA h g-1 at 5, 10, 15 and 20 C, respectively, 1 C = 1 A g-1), and a superior cycling performance at an ultrahigh rate (760 mA h g-1 at 5 C after 1000 cycles) are achieved by this lithium-ion-battery anode material.

  12. Carbon-Encapsulated Co3O4 Nanoparticles as Anode Materials with Super Lithium Storage Performance

    PubMed Central

    Leng, Xuning; Wei, Sufeng; Jiang, Zhonghao; Lian, Jianshe; Wang, Guoyong; Jiang, Qing

    2015-01-01

    A high-performance anode material for lithium storage was successfully synthesized by glucose as carbon source and cobalt nitrate as Co3O4 precursor with the assistance of sodium chloride surface as a template to reduce the carbon sheet thickness. Ultrafine Co3O4 nanoparticles were homogeneously embedded in ultrathin porous graphitic carbon in this material. The carbon sheets, which have large specific surface area, high electronic conductivity, and outstanding mechanical flexibility, are very effective to keep the stability of Co3O4 nanoparticales which has a large capacity. As a consequence, a very high reversible capacity of up to 1413 mA h g−1 at a current density of 0.1 A g−1 after 100 cycles, a high rate capability (845, 560, 461 and 345 mA h g−1 at 5, 10, 15 and 20 C, respectively, 1 C = 1 A g−1), and a superior cycling performance at an ultrahigh rate (760 mA h g−1 at 5 C after 1000 cycles) are achieved by this lithium-ion-battery anode material. PMID:26564802

  13. Bismuth Nanoparticles Embedded in Carbon Spheres as Anode Materials for Sodium/Lithium-Ion Batteries.

    PubMed

    Yang, Fuhua; Yu, Fan; Zhang, Zhian; Zhang, Kai; Lai, Yanqing; Li, Jie

    2016-02-12

    Sodium-ion batteries (SIBs) are regarded as an attractive alternative to lithium-ion batteries (LIBs) for large-scale commercial applications, because of the abundant terrestrial reserves of sodium. Exporting suitable anode materials is the key to the development of SIBs and LIBs. In this contribution, we report on the fabrication of Bi@C microspheres using aerosol spray pyrolysis technique. When used as SIBs anode materials, the Bi@C microsphere delivered a high capacity of 123.5 mAh g(-1) after 100 cycles at 100 mA g(-1) . The rate performance is also impressive (specific capacities of 299, 252, 192, 141, and 90 mAh g(-1) are obtained under current densities of 0.1, 0.2, 0.5, 1, and 2 A g(-1) , respectively). Furthermore, the Bi@C microsphere also proved to be suitable LIB anode materials. The excellent electrochemical performance for both SIBs and LIBs can attributed to the Bi@C microsphere structure with Bi nanoparticles uniformly dispersed in carbon spheres. PMID:26757402

  14. Carbonate fuel cell anodes

    DOEpatents

    Donado, R.A.; Hrdina, K.E.; Remick, R.J.

    1993-04-27

    A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process is described for production of the lithium ferrite containing anode by slipcasting.

  15. Carbonate fuel cell anodes

    DOEpatents

    Donado, Rafael A.; Hrdina, Kenneth E.; Remick, Robert J.

    1993-01-01

    A molten alkali metal carbonates fuel cell porous anode of lithium ferrite and a metal or metal alloy of nickel, cobalt, nickel/iron, cobalt/iron, nickel/iron/aluminum, cobalt/iron/aluminum and mixtures thereof wherein the total iron content including ferrite and iron of the composite is about 25 to about 80 percent, based upon the total anode, provided aluminum when present is less than about 5 weight percent of the anode. A process for production of the lithium ferrite containing anode by slipcasting.

  16. Electrochemical properties of iron oxides/carbon nanotubes as anode material for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zeng, Zhipeng; Zhao, Hailei; Lv, Pengpeng; Zhang, Zijia; Wang, Jie; Xia, Qing

    2015-01-01

    A composited anode material with combined Fe3O4/FeO nanotube and carbon shell is synthesized by a facile hydrothermal method with subsequent CVD heat treatment. The as-prepared Fe3O4/FeO/C composite shows excellent cycle stability and rate capability as lithium ion battery anode. We study the effect of FeO on the electrochemical performances of the Fe3O4/FeO/C electrode. A capacity climbing phenomenon can be observed for the Fe3O4/FeO/C electrodes, which tends to be more evident with increasing FeO content. The "extra capacity" is correlated with the reversible formation of polymeric gel-like film on the particle surface of active materials, which is electrochemical active towards Li ions. The FeO component presents a certain extent of catalytic role in assisting the formation of the gel-like film. Transmission electron microscope (TEM) and electrochemical impedance spectroscopy (EIS) analytical technique are combined to further confirm the reversible growth of the SEI gel-like film. High temperature promotes the formation of gel-like film, while the resistance from the film decreases remarkably with temperature due to the enhanced lithium ion conductivity. The film contributes little to the whole EIS resistance of Fe3O4/FeO nanotube/carbon electrode. Tentative explanations based on the current experiments and existing literature are made to explain such unusual finding.

  17. Nanostructured Carbon/Antimony Composites as Anode Materials for Lithium-Ion Batteries with Long Life.

    PubMed

    Cheng, Yong; Yi, Zheng; Wang, Chunli; Wang, Lidong; Wu, Yaoming; Wang, Limin

    2016-08-01

    A series of nanostructured carbon/antimony composites have been successfully synthesized by a simple sol-gel, high-temperature carbon thermal reduction process. In the carbon/antimony composites, antimony nanoparticles are homogeneously dispersed in the pyrolyzed nanoporous carbon matrix. As an anode material for lithium-ion batteries, the C/Sb10 composite displays a high initial discharge capacity of 1214.6 mAh g(-1) and a reversible charge capacity of 595.5 mAh g(-1) with a corresponding coulombic efficiency of 49 % in the first cycle. In addition, it exhibits a high reversible discharge capacity of 466.2 mAh g(-1) at a current density of 100 mA g(-1) after 200 cycles and a high rate discharge capacity of 354.4 mAh g(-1) at a current density of 1000 mA g(-1) . The excellent cycling stability and rate discharge performance of the C/Sb10 composite could be due to the uniform dispersion of antimony nanoparticles in the porous carbon matrix, which can buffer the volume expansion and maintain the integrity of the electrode during the charge-discharge cycles. PMID:27310879

  18. Dual-carbon enhanced silicon-based composite as superior anode material for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Jie; Liu, Dai-Huo; Wang, Ying-Ying; Hou, Bao-Hua; Zhang, Jing-Ping; Wang, Rong-Shun; Wu, Xing-Long

    2016-03-01

    Dual-carbon enhanced Si-based composite (Si/C/G) has been prepared via employing the widely distributed, low-cost and environmentally friendly Diatomite mineral as silicon raw material. The preparation processes are very simple, non-toxic and easy to scale up. Electrochemical tests as anode material for lithium ion batteries (LIBs) demonstrate that this Si/C/G composite exhibits much improved Li-storage properties in terms of superior high-rate capabilities and excellent cycle stability compared to the pristine Si material as well as both single-carbon modified composites. Specifically for the Si/C/G composite, it can still deliver a high specific capacity of about 470 mAh g-1 at an ultrahigh current density of 5 A g-1, and exhibit a high capacity of 938 mAh g-1 at 0.1 A g-1 with excellent capacity retention in the following 300 cycles. The significantly enhanced Li-storage properties should be attributed to the co-existence of both highly conductive graphite and amorphous carbon in the Si/C/G composite. While the former can enhance the electrical conductivity of the obtained composite, the latter acts as the adhesives to connect the porous Si particulates and conductive graphite flakes to form robust and stable conductive network.

  19. Potential threshold of anode materials for foldable lithium-ion batteries featuring carbon nanotube current collectors

    NASA Astrophysics Data System (ADS)

    Wang, Qing Hui; Zhong, Sheng Wen; Hu, Jing Wei; Liu, Ting; Zhu, Xian Yan; Chen, Jing; Hong, Yin Yan; Wu, Zi Ping

    2016-04-01

    Flexible carbon nanotube macro-films (CMFs) are perfect current collectors for preparing foldable lithium-ion batteries (LIBs). However, selecting appropriate anodes for electrode is difficult because of the different potentials (vs. Li/Li+) of carbon nanotubes and traditional metallic current collector. This study demonstrated an additional reaction at potential below 0.9 V (vs. Li/Li+) caused by CMF, And Li+ will be constrained, which decreased capacity of anode/CMF electrode. Conversely, results changed when the anode potential exceeded 0.9 V (vs. Li/Li+) because Li+ passed the potential threshold, and the CMF retained its electrochemical inactivity. Consequently, the CMF-based foldable LIBs performed well. The potential threshold mechanism of anode is expected to provide new impetus to both academia and industry for exploring flexible or foldable LIBs.

  20. Surface modifications for carbon lithium intercalation anodes

    DOEpatents

    Tran, Tri D.; Kinoshita, Kimio

    2000-01-01

    A prefabricated carbon anode containing predetermined amounts of passivating film components is assembled into a lithium-ion rechargeable battery. The modified carbon anode enhances the reduction of the irreversible capacity loss during the first discharge of a cathode-loaded cell. The passivating film components, such as Li.sub.2 O and Li.sub.2 CO.sub.3, of a predetermined amount effective for optimal passivation of carbon, are incorporated into carbon anode materials to produce dry anodes that are essentially free of battery electrolyte prior to battery assembly.

  1. Effect of carbon recycle materials on properties of bench scale prebaked anodes for aluminum smelting

    NASA Astrophysics Data System (ADS)

    Belitskus, David

    1981-03-01

    Bench scale aluminum smelting anodes were produced from aggregates having butts contents of 0 to 40 wt pct, from 100 pct mixer scrap or 100 pct green anode scrap, and from aggregates having used potlining contents of 0 to 25 pct to determine effects on important properties. Butts additions increased baked apparent density, decreased electrical resistivity, baking shrinkage, and thermal shock cracking resistance, and had little effect on excess carbon consumption. Use of 100 pct mixer scrap was equivalent to use of freshly blended coke and pitch. Use of 100 pct green anode scrap increased baked apparent density, decreased electrical resistivity, and may have reduced carbon consumption. Additions of used potlining increased carbon consumption, had little effect on electrical resistivity, and had a variable effect on thermal shock cracking resistance.

  2. Electrically exploded silicon/carbon nanocomposite as anode material for lithium-ion batteries.

    PubMed

    Farooq, Umer; Choi, Jeong-Hee; Kim, Doohun; Pervez, Syed Atif; Yaqub, Adnan; Hwang, Min-Ji; Lee, You-Jin; Lee, Won-Jae; Choi, Hae-Young; Lee, Sang-Hoon; You, Ji-Hyun; Ha, Chung-Wan; Doh, Chil-Hoon

    2014-12-01

    In this work, silicon (Si) containing carbon coated core-shell nanostructures were synthesized by electrical explosion of Si wires in ethanol solution followed by high energy mechanical milling (HEMM) process. Material characterization was carried-out using transmission electron microscopy (TEM), field-emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDS), and X-ray diffraction (XRD) analysis. HEMM led to very fine and amorphous Si particles in the presence of carbon and inactive Silicon-Carbide (SiC) matrix. These Si based nanocomposites, obtained through electrical explosion followed by HEMM (milled sample), exhibited enhanced electrochemical performance than unmilled nanocomposites, when evaluated as anode material for lithium-ion batteries (LIBs). On completion of (the) 1st cycle, milled and unmilled sample(s) showed specific discharge capacities around 825 mAh/g and 717 mAh/g, respectively. Interestingly, the coulombic efficiencies of milled and unmilled samples were 98.5% and 97% after 60th cycle respectively. The enhanced electrochemical performance is attributed to fine and amorphous Si based nanocomposite obtained through HEMM process. PMID:25971062

  3. Sulfur tolerant anode materials

    SciTech Connect

    Not Available

    1987-02-01

    The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

  4. Anodic aluminum oxide and carbon nanotube-based nanostructured materials for hydrogen sensors

    NASA Astrophysics Data System (ADS)

    Rumiche, Francisco

    Hydrogen is envisioned as one of the most attractive and sustainable energy systems to power future generations. Because of their particular surface characteristics and distinctive physical properties nanoscale materials are promising candidates for the development of high performance hydrogen sensors, essential components to ensure the safe operation of the infrastructure and to facilitate the public acceptance of hydrogen technologies. This investigation is dedicated to the development of anodic aluminum oxide (AAO) and double wall carbon nanotube (DWNT)-based nanostructured materials for high performance hydrogen sensors. It addresses the controlled synthesis of nanostructures with defined geometries and sizes, study of physical and electronic properties, and the integration into functional hydrogen sensing devices. Compared to current palladium thin film sensors and nanostructured devices the AAO-based nanostructure exhibits faster response times without compromising sensitivity and selectivity. Performance of developed DWNT-based nanostructures is comparable to that for high performance hydrogen sensors fabricated with SWNTs, but with potential improvement in mechanical and thermal resistance associated to the double layer structure.

  5. Investigation of Metal Oxide/Carbon Nano Material as Anode for High Capacity Lithium-ion Cells

    NASA Technical Reports Server (NTRS)

    Wu, James Jianjun; Hong, Haiping

    2014-01-01

    NASA is developing high specific energy and high specific capacity lithium-ion battery (LIB) technology for future NASA missions. Current state-of-art LIBs have issues in terms of safety and thermal stability, and are reaching limits in specific energy capability based on the electrochemical materials selected. For example, the graphite anode has a limited capability to store Li since the theoretical capacity of graphite is 372 mAh/g. To achieve higher specific capacity and energy density, and to improve safety for current LIBs, alternative advanced anode, cathode, and electrolyte materials are pursued under the NASA Advanced Space Power System Project. In this study, the nanostructed metal oxide, such as Fe2O3 on carbon nanotubes (CNT) composite as an LIB anode has been investigated.

  6. Carbon nanofibers derived from cellulose nanofibers as a long-life anode material for rechargeable sodium-ion batteries

    SciTech Connect

    Luo, W; Schardt, J; Bommier, C; Wang, B; Razink, J; Simonsen, J; Ji, XL

    2013-01-01

    A highly reversible anode is indispensable to the future success of sodium-ion batteries (SIBs). Herein, carbon nanofibers (CNFs) derived from cellulose nanofibers are investigated as an anode material for SIBs. The CNFs exhibit very promising electrochemical properties, including a high reversible capacity (255 mA h g(-1) at 40 mA g(-1)), good rate capability (85 mA h g(-1) at 2000 mA g(-1)), and excellent cycling stability (176 mA h g(-1) at 200 mA g(-1) over 600 cycles).

  7. Cellulose-based carbon-A potential anode material for lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Kierzek, Krzysztof; Piotrowska, Aleksandra; Machnikowski, Jacek

    2015-11-01

    A series of hard carbons was produced by the carbonization of microcrystalline cellulose powder in the temperature range of 950-1100 °C. The properties of the carbons were characterized using elemental analysis, X-ray diffraction and N2 and CO2 adsorption. The effect of heat-treatment temperature (HTT), pyrolytic carbon (PC) coating and discharging mode on the lithium insertion/deinsertion behavior of the carbons was assessed in a coin-type half-cell with metal lithium cathode. Increasing cellulose HTT modifies mostly carbon porosity, the surface area (SDFT) decreases from about 500 to 167 m2 g-1. It is associated with lowering the reversible Crev and irreversible Cirr capacities, but without improving relatively low (0.72) 1st cycle coulombic efficiency. Applying constant current (CC)+constant voltage (CV) discharging mode instead of conventional CC enhances the reversible capacity by 15-18%. PC coating is effective in reducing Cirr by ∼20% with a little change of Crev. The best capacity parameters, Crev of 458 mA h g-1 and Cirr of 139 mA h g-1, were measured for PC coated 1000 °C carbon. The prolonged cycling of full-cell assembled with anode of the carbon and commercial cathode revealed that after initial 20 cycles the capacity decay (0.029 mA h/cycle) is comparable to that of commercial cell with graphite-based anode.

  8. Caramel popcorn shaped silicon particle with carbon coating as a high performance anode material for Li-ion batteries.

    PubMed

    He, Meinan; Sa, Qina; Liu, Gao; Wang, Yan

    2013-11-13

    Silicon is a very promising anode material for lithium ion batteries. It has a 4200 mAh/g theoretical capacity, which is ten times higher than that of commercial graphite anodes. However, when lithium ions diffuse to Si anodes, the volume of Si will expand to almost 400% of its initial size and lead to the crack of Si. Such a huge volume change and crack cause significant capacity loss. Meanwhile, with the crack of Si particles, the conductivity between the electrode and the current collector drops. Moreover, the solid electrolyte interphase (SEI), which is generated during the cycling, reduces the discharge capacity. These issues must be addressed for widespread application of this material. In this work, caramel popcorn shaped porous silicon particles with carbon coating are fabricated by a set of simple chemical methods as active anode material. Si particles are etched to form a porous structure. The pores in Si provide space for the volume expansion and liquid electrolyte diffusion. A layer of amorphous carbon is formed inside the pores, which gives an excellent isolation between the Si particle and electrolyte, so that the formation of the SEI layer is stabilized. Meanwhile, this novel structure enhances the mechanical properties of the Si particles, and the crack phenomenon caused by the volume change is significantly restrained. Therefore, an excellent cycle life under a high rate for the novel Si electrode is achieved. PMID:24111737

  9. Three-dimensional silicon/carbon core-shell electrode as an anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Kim, Jung Sub; Pfleging, Wilhelm; Kohler, Robert; Seifert, Hans Jürgen; Kim, Tae Yong; Byun, Dongjin; Jung, Hun-Gi; Choi, Wonchang; Lee, Joong Kee

    2015-04-01

    Practical application of silicon anodes for lithium-ion batteries has been mainly hindered because of their low electrical conductivity and large volume change (ca. 300%) occurring during the lithiation and delithiation processes. Thus, the surface engineering of active particles (material design) and the modification of electrode structure (electrode design) of silicon are necessary to alleviate these critical limiting factors. Silicon/carbon core-shell particles (Si@C, material design) are prepared by the thermal decomposition and subsequent three-dimensional (3D) electrode structures (electrode design) with a channel width of 15 μm are incorporated using the laser ablation process. The electrochemical characteristics of 3D Si@C used as the anode material for lithium-ion batteries are investigated to identify the effects of material and electrode design. By the introduction of a carbon coating and the laser structuring, an enhanced performance of Si anode materials exhibiting high specific capacity (>1200 mAh g-1 over 300 cycles), good rate capability (1170 mAh g-1 at 8 A g-1), and stable cycling is achieved. The morphology of the core-shell active material combined with 3D channel architecture can minimize the volume expansion by utilizing the void space during the repeated cycling.

  10. Antimony nanoparticles anchored on interconnected carbon nanofibers networks as advanced anode material for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Hou, Hongshuai; Jing, Mingjun; Yang, Yingchang; Zhang, Yan; Song, Weixin; Yang, Xuming; Chen, Jun; Chen, Qiyuan; Ji, Xiaobo

    2015-06-01

    Interconnected carbon nanofibers networks (ICNNs) prepared through the carbonization of polypyrrole (PPy) precursor are utilized as conductive pathways and buffer to improve the Na storage performance of antimony (Sb) as anode for sodium-ion batteries (SIBs). The as-obtained Sb/ICNNs composite exhibits excellent cycle stability. The reversible capacity can remain 542.5 mAh g-1 with a high capacity retention of 96.7% after 100 cycles at a current density of 100 mA g-1. And the superior rate performance is also observed, the reversible capacity can still reach 325 mAh g-1 at a high current density of 3200 mA g-1. These great electrochemical performances observed above suggest that this type of composite can be a nice option for advanced SIBs anode materials and may be extended to other active materials/ICNNs composite electrode.

  11. Nitrogen-doped porous carbon nanosheets as low-cost, high-performance anode material for sodium-ion batteries.

    PubMed

    Wang, Heng-guo; Wu, Zhong; Meng, Fan-lu; Ma, De-long; Huang, Xiao-lei; Wang, Li-min; Zhang, Xin-bo

    2013-01-01

    Between the sheets: Sodium-ion batteries are an attractive, low-cost alternative to lithium-ion batteries. Nitrogen-doped porous carbon sheets are prepared by chemical activation of polypyrrole-functionalized graphene sheets. When using the sheets as anode material in sodium-ion batteries, their unique compositional and structural features result in high reversible capacity, good cycling stability, and high rate capability. PMID:23225752

  12. Carbon coated SnO2 nanoparticles anchored on CNT as a superior anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Ma, Chunrong; Zhang, Weimin; He, Yu-Shi; Gong, Qiang; Che, Haiying; Ma, Zi-Feng

    2016-02-01

    Hierarchically structured carbon coated SnO2 nanoparticles well-anchored on the surface of a CNT (C-SnO2/CNT) material were synthesized by a facile hydrothermal process and subsequent carbonization. The as-obtained C-SnO2/CNT hybrid, when applied as an anode material for lithium ion batteries (LIBs), showed a high reversible capacity up to 1572 mA h g-1 at 200 mA g-1 with a superior rate capability (685 mA h g-1 at 4000 mA g-1). Even after 100 charge/discharge cycles at 1000 mA g-1, a specific capacity of 1100 mA h g-1 can still be maintained. Such impressive electrochemical performance can be mainly attributed to the hierarchical sandwiched structure and strong synergistic effects of the ultrafine SnO2 nanoparticles and the carbon coating, and thus presents this material a promising anode material for LIBs.Hierarchically structured carbon coated SnO2 nanoparticles well-anchored on the surface of a CNT (C-SnO2/CNT) material were synthesized by a facile hydrothermal process and subsequent carbonization. The as-obtained C-SnO2/CNT hybrid, when applied as an anode material for lithium ion batteries (LIBs), showed a high reversible capacity up to 1572 mA h g-1 at 200 mA g-1 with a superior rate capability (685 mA h g-1 at 4000 mA g-1). Even after 100 charge/discharge cycles at 1000 mA g-1, a specific capacity of 1100 mA h g-1 can still be maintained. Such impressive electrochemical performance can be mainly attributed to the hierarchical sandwiched structure and strong synergistic effects of the ultrafine SnO2 nanoparticles and the carbon coating, and thus presents this material a promising anode material for LIBs. Electronic supplementary information (ESI) available: The SEM and TEM images of CNT@SnO2, the HRTEM image of C-SnO2/CNT composites, nitrogen adsorption/desorption isotherms and the BJH distribution, TGA analysis, and the cycling test for SnO2 and CNT electrodes. See DOI: 10.1039/c5nr07996a

  13. Fe3O4/carbon core-shell nanotubes as promising anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Xia, Hui; Wan, Yunhai; Yuan, Guoliang; Fu, Yongsheng; Wang, Xin

    2013-11-01

    Magnetite (Fe3O4)/carbon core-shell nanotubes have been successfully synthesized by partial reduction of monodispersed hematite (Fe2O3) nanotubes with carbon coating. Fe2O3 is completely converted to Fe3O4 during the reduction process and a thin carbon layer is continuously coated on the surface of Fe3O4 with the nanotube morphology reserved. The Fe3O4/carbon core-shell nanotubes exhibit superior electrochemical properties as anode material for lithium-ion batteries compared with the Fe2O3 and Fe3O4 nanotubes. The Fe3O4/carbon core-shell nanotubes electrode shows a large reversible capacity up to 938 mAh g-1 as well as improved cycling stability and excellent rate capability. The promising anode performance of the Fe3O4/carbon core-shell nanotubes can be attributed to their tubular morphology and continuous carbon coating, which provide improved structural stability and fast charge transport.

  14. Carbon coated SnO2 nanoparticles anchored on CNT as a superior anode material for lithium-ion batteries.

    PubMed

    Ma, Chunrong; Zhang, Weimin; He, Yu-Shi; Gong, Qiang; Che, Haiying; Ma, Zi-Feng

    2016-02-11

    Hierarchically structured carbon coated SnO2 nanoparticles well-anchored on the surface of a CNT (C-SnO2/CNT) material were synthesized by a facile hydrothermal process and subsequent carbonization. The as-obtained C-SnO2/CNT hybrid, when applied as an anode material for lithium ion batteries (LIBs), showed a high reversible capacity up to 1572 mA h g(-1) at 200 mA g(-1) with a superior rate capability (685 mA h g(-1) at 4000 mA g(-1)). Even after 100 charge/discharge cycles at 1000 mA g(-1), a specific capacity of 1100 mA h g(-1) can still be maintained. Such impressive electrochemical performance can be mainly attributed to the hierarchical sandwiched structure and strong synergistic effects of the ultrafine SnO2 nanoparticles and the carbon coating, and thus presents this material a promising anode material for LIBs. PMID:26866581

  15. Pyrolytic carbon derived from coffee shells as anode materials for lithium batteries

    NASA Astrophysics Data System (ADS)

    Hwang, Yun Ju; Jeong, Soo Kyung; Nahm, Kee Suk; Shin, Jae Sun; Manuel Stephan, A.

    2007-02-01

    Disordered carbonaceous materials have been obtained by pyrolysis of coffee shells at 800 and 900 °C with pore-forming substances such as KOH and ZnCl2. X-ray diffraction studies revealed a carbon structure with a large number of disorganized single layer carbon sheets. The structure and morphology of the materials have been greatly varied upon the addition of porogens. The prepared carbon materials have been subjected to cycling studies. The KOH-treated products offered higher capacity with improved stability than those with untreated and ZnCl2-treated one.

  16. Carbon-coated Mo3Sb7 composite as anode material for sodium ion batteries with long cycle life

    NASA Astrophysics Data System (ADS)

    Li, Wei; Hu, Chen; Zhou, Min; Tao, Hongwei; Wang, Kangli; Cheng, Shijie; Jiang, Kai

    2016-03-01

    Herein, carbon-coated Mo3Sb7 composite (Mo3Sb7@C) is successfully synthesized via a high temperature reaction accompanied by post-milling, and investigated as an anode material for sodium ion batteries. The as-prepared Mo3Sb7@C demonstrates a capacity of 400 mAh g-1 at 0.2C (1C = 494 mA g-1), sustains 180 mAh g-1 at 20C, as well as maintains 338 mAh g-1 at 0.5C even after 800 cycles with a capacity retention of 91.8%, indicating an excellent cycling stability. The high performance of Mo3Sb7@C is expected to be ascribed to the buffer effect of Mo component for Sb associated with carbon coating and refined particle sizes of Mo3Sb7 during the cycling. In addition, a sodium ion full cell composing of Mo3Sb7@C anode and excessive Na3V2(PO4)3@C cathode is constructed to testify the performance and possibility of Mo3Sb7@C used as full cell anode.

  17. Nanostructured Black Phosphorus/Ketjenblack-Multiwalled Carbon Nanotubes Composite as High Performance Anode Material for Sodium-Ion Batteries.

    PubMed

    Xu, Gui-Liang; Chen, Zonghai; Zhong, Gui-Ming; Liu, Yuzi; Yang, Yong; Ma, Tianyuan; Ren, Yang; Zuo, Xiaobing; Wu, Xue-Hang; Zhang, Xiaoyi; Amine, Khalil

    2016-06-01

    Sodium-ion batteries are promising alternatives to lithium-ion batteries for large-scale applications. However, the low capacity and poor rate capability of existing anodes for sodium-ion batteries are bottlenecks for future developments. Here, we report a high performance nanostructured anode material for sodium-ion batteries that is fabricated by high energy ball milling to form black phosphorus/Ketjenblack-multiwalled carbon nanotubes (BPC) composite. With this strategy, the BPC composite with a high phosphorus content (70 wt %) could deliver a very high initial Coulombic efficiency (>90%) and high specific capacity with excellent cyclability at high rate of charge/discharge (∼1700 mAh g(-1) after 100 cycles at 1.3 A g(-1) based on the mass of P). In situ electrochemical impedance spectroscopy, synchrotron high energy X-ray diffraction, ex situ small/wide-angle X-ray scattering, high resolution transmission electronic microscopy, and nuclear magnetic resonance were further used to unravel its superior sodium storage performance. The scientific findings gained in this work are expected to serve as a guide for future design on high performance anode material for sodium-ion batteries. PMID:27222911

  18. Hierarchical SnO2 /Carbon Nanofibrous Composite Derived from Cellulose Substance as Anode Material for Lithium-Ion Batteries.

    PubMed

    Wang, Mengya; Li, Shun; Zhang, Yiming; Huang, Jianguo

    2015-11-01

    A hierarchical fibrous SnO2 /carbon nanocomposite composed of fine SnO2 nanocrystallites immobilized as a thin layer on a carbon nanofiber surface was synthesized employing natural cellulose substance as both scaffold and carbon source. It was achieved by calcination/carbonization of the as-deposited SnO2 -gel/cellulose hybrid in an argon atmosphere. As being employed as an anode material for lithium-ion batteries, the porous structures, small SnO2 crystallite sizes, and the carbon buffering matrix possessed by the nanocomposite facilitate the electrode-electrolyte contact, promote the electron transfer and Li(+) diffusion, and relieve the severe volume change and aggregation of the active particles during the charge/discharge cycles. Hence, the nanocomposite showed high reversible capacity, significant cycling stability, and rate capability that are superior to the nanotubular SnO2 and SnO2 sol-gel powder counter materials. For such a composite with 27.8 wt % SnO2 content and 346.4 m(2)  g(-1) specific surface area, a capacity of 623 mAh g(-1) was delivered after 120 cycles at 0.2 C. Further coating of the SnO2 /carbon nanofibers with an additional carbon layer resulted in an improved cycling stability and rate performance. PMID:26397841

  19. Carbon Materials Embedded with Metal Nanoparticles as Anode in Lithium-Ion Batteries

    NASA Technical Reports Server (NTRS)

    Hung, Ching-cheh

    2002-01-01

    Carbon materials containing metal nanoparticles that can form an alloy with lithium were tested for their capacity and cycle life to store and release lithium electrochemically. Metal nanoparticles may provide the additional lithium storage capacity as well as additional channels to conduct lithium in carbon. The cycle life of this carbon-metal composite can be long because the solid-electrolyte interface (SEI) on the carbon surface may protect both lithium and the metal particles in the carbon interior. In addition, the voids in the carbon interior may accommodate the nanoparticle's volume change, and such volume change may not cause much internal stress due to small sizes of the nanoparticles. This concept of improving carbon's performance to store and release lithium was demonstrated using experimental cells of C(Pd)/0.5M Lil-50/50 (vol.%) EC and DMC/Li, where C(Pd) was graphitized carbon fibers containing palladium nanoparticles, EC was ethylene carbonate, and DMC was dimethyl carbonate. However, such improvement was not observed if the Pd nanoparticles are replaced by aluminum, possibly because the aluminum nanoparticles were oxidized in air during storage, resulting in an inert oxide of aluminum. Further studies are needed to use this concept for practical applications.

  20. Porous carbon nanotubes decorated with nanosized cobalt ferrite as anode materials for high-performance lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Lingyan; Zhuo, Linhai; Cheng, Haiyang; Zhang, Chao; Zhao, Fengyu

    2015-06-01

    Generally, the fast ion/electron transport and structural stability dominate the superiority in lithium-storage applications. In this work, porous carbon nanotubes decorated with nanosized CoFe2O4 particles (p-CNTs@CFO) have been rationally designed and synthesized by the assistance of supercritical carbon dioxide (scCO2). When tested as anode materials for lithium-ion batteries, the p-CNTs@CFO composite exhibits outstanding electrochemical behavior with high lithium-storage capacity (1077 mAh g-1 after 100 cycles) and rate capability (694 mAh g-1 at 3 A g-1). These outstanding electrochemical performances are attributed to the synergistic effect of porous p-CNTs and nanosized CFO. Compared to pristine CNTs, the p-CNTs with substantial pores in the tubes possess largely increased specific surface area and rich oxygen-containing functional groups. The porous structure can not only accommodate the volume change during lithiation/delithiation processes, but also provide bicontinuous electron/ion pathways and large electrode/electrolyte interface, which facilitate the ion diffusion kinetics, improving the rate performance. Moreover, the CFO particles are bonded strongly to the p-CNTs through metal-oxygen bridges, which facilitate the electron fast capture from p-CNTs to CFO, and thus resulting in a high reversible capacity and excellent rate performance. Overall, the porous p-CNTs provide an efficient way for ion diffusion and continuous electron transport as anode materials.

  1. Carbon-Confined SnO2-Electrodeposited Porous Carbon Nanofiber Composite as High-Capacity Sodium-Ion Battery Anode Material.

    PubMed

    Dirican, Mahmut; Lu, Yao; Ge, Yeqian; Yildiz, Ozkan; Zhang, Xiangwu

    2015-08-26

    Sodium resources are inexpensive and abundant, and hence, sodium-ion batteries are promising alternative to lithium-ion batteries. However, lower energy density and poor cycling stability of current sodium-ion batteries prevent their practical implementation for future smart power grid and stationary storage applications. Tin oxides (SnO2) can be potentially used as a high-capacity anode material for future sodium-ion batteries, and they have the advantages of high sodium storage capacity, high abundance, and low toxicity. However, SnO2-based anodes still cannot be used in practical sodium-ion batteries because they experience large volume changes during repetitive charge and discharge cycles. Such large volume changes lead to severe pulverization of the active material and loss of electrical contact between the SnO2 and carbon conductor, which in turn result in rapid capacity loss during cycling. Here, we introduce a new amorphous carbon-coated SnO2-electrodeposited porous carbon nanofiber (PCNF@SnO2@C) composite that not only has high sodium storage capability, but also maintains its structural integrity while ongoing repetitive cycles. Electrochemical results revealed that this SnO2-containing nanofiber composite anode had excellent electrochemical performance including high-capacity (374 mAh g(-1)), good capacity retention (82.7%), and large Coulombic efficiency (98.9% after 100th cycle). PMID:26252051

  2. An Amorphous Carbon Nitride Composite Derived from ZIF-8 as Anode Material for Sodium-Ion Batteries.

    PubMed

    Fan, Jing-Min; Chen, Jia-Jia; Zhang, Qian; Chen, Bin-Bin; Zang, Jun; Zheng, Ming-Sen; Dong, Quan-Feng

    2015-06-01

    An composite comprising amorphous carbon nitride (ACN) and zinc oxide is derived from ZIF-8 by pyrolysis. The composite is a promising anode material for sodium-ion batteries. The nitrogen content of the ACN composite is as high as 20.4 %, and the bonding state of nitrogen is mostly pyridinic, as determined by X-ray photoelectron spectroscopy (XPS). The composite exhibits an excellent Na(+) storage performance with a reversible capacity of 430 mA h g(-1) and 146 mA h g(-1) at current densities of 83 mA g(-1) and 8.33 A g(-1) , respectively. A specific capacity of 175 mA h g(-1) was maintained after 2000 cycles at 1.67 A g(-1) , with only 0.016 % capacity degradation per cycle. Moreover, an accelerating rate calorimetry (ARC) test demonstrates the excellent thermal stability of the composite, with a low self heating rate and high onset temperature (210 °C). These results shows its promise as a candidate material for high-capacity, high-rate anodes for sodium-ion batteries. PMID:25940023

  3. Nano-structured composite of Si/(S-doped-carbon nanowire network) as anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shao, Dan; Tang, Daoping; Yang, Jianwen; Li, Yanwei; Zhang, Lingzhi

    2015-11-01

    Novel nanostructured silicon composites, Si/Poly(3,4-ethylenedioxythiophene) nanowire network (Si/PNW) and Si/(S-doped-carbon nanowire network) (Si/S-CNW), are prepared by a soft-template polymerization of 3,4-ethylenedioxythiophene (EDOT) using sodium dodecyl sulfate (SDS) as surfactant with the presence of Si nanoparticles and a subsequent carbonization of Si/PNW, respectively. The presence of Si nanoparticles in the soft-template polymerization of EDOT plays a critical role in the formation of PEDOT nanowire network instead of 1D nanowire. After the carbonization of PEDOT, the S-doped-carbon nanowire network matrix shows higher electrical conductivity than PNW counterpart, which facilitates to construct robust conductive bridges between Si nanoparticles and provide large electrode/electrolyte interfaces for rapid charge transfer reactions. Thus, Si/S-CNW composite exhibits excellent cycling stability and rate capability as anode material, retaining a specific capacity of 820 mAh g-1 after 400 cycles with a very small capacity fade of 0.09% per cycle.

  4. Interconnected MoO2 nanocrystals with carbon nanocoating as high-capacity anode materials for lithium-ion batteries.

    PubMed

    Zhou, Liang; Wu, Hao Bin; Wang, Zhiyu; Lou, Xiong Wen David

    2011-12-01

    A facile one-pot hydrothermal method has been developed for the preparation of carbon-coated MoO(2) nanocrystals. The annealed MoO(2)-C nanocomposite consists of interconnected MoO(2)@C nanocrystals. When evaluated for lithium storage capabilities, these MoO(2)@C nanocrystals exhibit high specific capacities (~640 mA h g(-1) at 200 mA g(-1) and ~575 mA h g(-1) at 400 mA g(-1)) and excellent cycling stability. In view of the excellent lithium storage properties and the ease in large-scale preparation, the as-synthesized MoO(2)-C nanocomposite might be used as promising anode materials for high-performance lithium-ion batteries. PMID:22077330

  5. Electrochemical characterization of carbon coated bundle-type silicon nanorod for anode material in lithium ion secondary batteries

    NASA Astrophysics Data System (ADS)

    Halim, Martin; Kim, Jung Sub; Choi, Jeong-Gil; Lee, Joong Kee

    2015-04-01

    Nanostructured silicon synthesis by surface modification of commercial micro-powder silicon was investigated in order to reduce the maximum volume change over cycle. The surface of micro-powder silicon was modified using an Ag metal-assisted chemical etching technique to produce nanostructured material in the form of bundle-type silicon nanorods. The volume change of the electrode using the nanostructured silicon during cycle was investigated using an in-situ dilatometer. Our result shows that nanostructured silicon synthesized using this method showed a self-relaxant characteristic as an anode material for lithium ion battery application. Moreover, binder selection plays a role in enhancing self-relaxant properties during delithiation via strong hydrogen interaction on the surface of the silicon material. The nanostructured silicon was then coated with carbon from propylene gas and showed higher capacity retention with the use of polyacrylic acid (PAA) binder. While the nano-size of the pore diameter control may significantly affect the capacity fading of nanostructured silicon, it can be mitigated via carbon coating, probably due to the prevention of Li ion penetration into 10 nano-meter sized pores.

  6. A SnO2@carbon nanocluster anode material with superior cyclability and rate capability for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    He, Min; Yuan, Lixia; Hu, Xianluo; Zhang, Wuxing; Shu, Jie; Huang, Yunhui

    2013-03-01

    A nanocluster composite assembled by interconnected ultrafine SnO2-C core-shell (SnO2@C) nanospheres is successfully synthesized via a simple one-pot hydrothermal method and subsequent carbonization. As an anode material for lithium-ion batteries, the thus-obtained nano-construction can provide a three-dimensional transport access for fast transfer of electrons and lithium ions. With the mixture of sodium carboxyl methyl cellulose and styrene butadiene rubber as a binder, the SnO2@C nanocluster anode exhibits superior cycling stability and rate capability due to a stable electrode structure. Discharge capacity reaches as high as 1215 mA h g-1 after 200 cycles at a current density of 100 mA g-1. Even at 1600 mA g-1, the capacity is still 520 mA h g-1 and can be recovered up to 1232 mA h g-1 if the current density is turned back to 100 mA g-1. The superior performance can be ascribed to the unique core-shell structure. The ultrafine SnO2 core gives a high reactive activity and accommodates volume change during cycling; while the thin carbon shell improves electronic conductivity, suppresses particle aggregation, supplies a continuous interface for electrochemical reaction and alleviates mechanical stress from repeated lithiation of SnO2.A nanocluster composite assembled by interconnected ultrafine SnO2-C core-shell (SnO2@C) nanospheres is successfully synthesized via a simple one-pot hydrothermal method and subsequent carbonization. As an anode material for lithium-ion batteries, the thus-obtained nano-construction can provide a three-dimensional transport access for fast transfer of electrons and lithium ions. With the mixture of sodium carboxyl methyl cellulose and styrene butadiene rubber as a binder, the SnO2@C nanocluster anode exhibits superior cycling stability and rate capability due to a stable electrode structure. Discharge capacity reaches as high as 1215 mA h g-1 after 200 cycles at a current density of 100 mA g-1. Even at 1600 mA g-1, the capacity is

  7. New High-Energy Nanofiber Anode Materials

    SciTech Connect

    Zhang, Xiangwu; Fedkiw, Peter; Khan, Saad; Huang, Alex; Fan, Jiang

    2013-11-15

    The overall goal of the proposed work was to use electrospinning technology to integrate dissimilar materials (lithium alloy and carbon) into novel composite nanofiber anodes, which simultaneously had high energy density, reduced cost, and improved abuse tolerance. The nanofiber structure allowed the anodes to withstand repeated cycles of expansion and contraction. These composite nanofibers were electrospun into nonwoven fabrics with thickness of 50 μm or more, and then directly used as anodes in a lithium-ion battery. This eliminated the presence of non-active materials (e.g., conducting carbon black and polymer binder) and resulted in high energy and power densities. The nonwoven anode structure also provided a large electrode-electrolyte interface and, hence, high rate capacity and good lowtemperature performance capability. Following are detailed objectives for three proposed project periods. • During the first six months: Obtain anodes capable of initial specific capacities of 650 mAh/g and achieve ~50 full charge/discharge cycles in small laboratory scale cells (50 to 100 mAh) at the 1C rate with less than 20 percent capacity fade; • In the middle of project period: Assemble, cycle, and evaluate 18650 cells using proposed anode materials, and demonstrate practical and useful cycle life (750 cycles of ~70% state of charge swing with less than 20% capacity fade) in 18650 cells with at least twice improvement in the specific capacity than that of conventional graphite electrodes; • At the end of project period: Deliver 18650 cells containing proposed anode materials, and achieve specific capacities greater than 1200 mAh/g and cycle life longer than 5000 cycles of ~70% state of charge swing with less than 20% capacity fade.

  8. Carbon-coated Fe-Mn-O composites as promising anode materials for lithium-ion batteries.

    PubMed

    Li, Tao; Wang, Yue-Ya; Tang, Rui; Qi, Yong-Xin; Lun, Ning; Bai, Yu-Jun; Fan, Run-Hua

    2013-10-01

    Fe-Mn-O composite oxides with various Fe/Mn molar ratios were prepared by a simple coprecipitation method followed by calcining at 600 °C, and carbon-coated oxides were obtained by pyrolyzing pyrrole at 550 °C. The cycling and rate performance of the oxides as anode materials are greatly associated with the Fe/Mn molar ratio. The carbon-coated oxides with a molar ratio of 2:1 exhibit a stable reversible capacity of 651.8 mA h g(-1) at a current density of 100 mA g(-1) after 90 cycles, and the capacities of 567.7, 501.3, 390.7, and 203.8 mA h g(-1) at varied densities of 200, 400, 800, and 1600 mA g(-1), respectively. The electrochemical performance is superior to that of single Fe3O4 or MnO prepared under the same conditions. The enhanced performance could be ascribed to the smaller particle size of Fe-Mn-O than the individuals, the mutual segregation of heterogeneous oxides of Fe3O4 and MnO during delithiation, and heterogeneous elements of Fe and Mn during lithiation. PMID:24007324

  9. SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes as high performance anode materials for lithium-ion batteries

    SciTech Connect

    Sun, Hongyu; Ahmad, Mashkoor; Luo, Jun; Shi, Yingying; Shen, Wanci; Zhu, Jing

    2014-01-01

    Graphical abstract: The synthesized SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes hybrid structures exhibit large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS{sub 2} nanoflakes. - Highlights: • Synthesis of SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes hybrid structures. • Simple solution-phase approach. • Morphology feature of SnS{sub 2}. • Enhanced performance as Li-ion batteries. - Abstract: SnS{sub 2} nanoflakes decorated multiwalled carbon nanotubes (MWCNTs) hybrid structures are directly synthesized via a simple solution-phase approach. The as-prepared SnS{sub 2}/MWCNTs structures are investigated as anode materials for Li-ion batteries as compared with SnS{sub 2} nanoflakes. It has been found that the composite structure exhibit excellent lithium storage performance with a large reversible capacity, superior cycling performance, and good rate capability as compared to pure SnS{sub 2} nanoflakes. The first discharge and charge capacities have been found to be 1416 and 518 mA h g{sup −1} for SnS{sub 2}/MWCNTs composite electrodes at a current density of 100 mA g{sup −1} between 5 mV and 1.15 V versus Li/Li{sup +}. A stable reversible capacity of ∼510 mA h g{sup −1} is obtained for 50 cycles. The improved electrochemical performance may be attributed to the flake-morphology feature of SnS{sub 2} and the addition of MWCNTs that can hinder the agglomeration of the active materials and improve the conductivity of the composite electrode simultaneously.

  10. Synthesis and electrochemical performances of amorphous carbon-coated Sn-Sb particles as anode material for lithium-ion batteries

    SciTech Connect

    Wang Zhong; Tian Wenhuai; Liu Xiaohe; Yang Rong; Li Xingguo

    2007-12-15

    The amorphous carbon coating on the Sn-Sb particles was prepared from aqueous glucose solutions using a hydrothermal method. Because the outer layer carbon of composite materials is loose cotton-like and porous-like, it can accommodate the expansion and contraction of active materials to maintain the stability of the structure, and hinder effectively the aggregation of nano-sized alloy particles. The as-prepared composite materials show much improved electrochemical performances as anode materials for lithium-ion batteries compared with Sn-Sb alloy and carbon alone. This amorphous carbon-coated Sn-Sb particle is extremely promising anode materials for lithium secondary batteries and has a high potentiality in the future use. - Graphical abstract: The amorphous carbon coating on the Sn-Sb particles was prepared from aqueous glucose solutions using a hydrothermal method. Because the outer layer carbon of composite materials is loose cotton-like and porous-like, it can accommodate the expansion and contraction of active materials to maintain the stability of the structure, and hinder effectively the aggregation of nano-sized alloy particles.

  11. New Anode Material for Rechargeable Li-ION Cells

    NASA Technical Reports Server (NTRS)

    Huang, C. -K.; Smart, M.; Halpert, G.; Surampudi, S.; Wolfenstine, J.

    1995-01-01

    Carbon materials, such as graphite, cokes, pitch and PAN fibers, are being evaluated in lithium batteries as alternate anode materials with some degree of success. There is an effort to look for other non-carbon anode materials which have larger Li capacity, higher rate capability, smaller first charge capacity loss and better mechanical stability during cycling. A Li-Mg-Si material is evaluated.

  12. Nickel-cobalt oxides/carbon nanoflakes as anode materials for lithium-ion batteries

    SciTech Connect

    NuLi, Yanna Zhang Peng; Guo Zaiping Liu Huakun; Yang Jun; Wang Jiulin

    2009-01-08

    Novel nickel-cobalt oxides/carbon nanoflakes with Ni/Co molar ratio = 1:1 and 1:2 have been synthesized by a convenient hydrothermal method followed by a simple calcination process. X-ray diffraction results showed that the composites were composed of NiO, Co{sub 3}O{sub 4}, and carbon. Scanning electron microscope measurements demonstrated that the composites were flakes less than 100 nm in thickness, and the corresponding energy dispersive spectroscopy mapping showed that the carbon was distributed homogeneously in the composites. The electrochemical results showed that the composite electrodes exhibited low initial coulombic efficiency and excellent charge-discharge cycling stability. Additionally, the effect of different Ni/Co molar ratios on the electrochemical properties of the composites was investigated, and better performance was obtained for the sample with a Ni/Co molar ratio of 1:2.

  13. SnO2 nanocrystals deposited on multiwalled carbon nanotubes with superior stability as anode material for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Ren, Jianguo; Yang, Junbing; Abouimrane, Ali; Wang, Dapeng; Amine, Khalil

    2011-10-01

    We report a novel ethylene glycol-mediated solvothermal-polyol route for synthesis of SnO2-CNT nanocomposites, which consist of highly dispersed 3-5 nm SnO2 nanocrystals on the surface of multiwalled carbon nanotubes (CNTs). As anode materials for Li-ion batteries, the nanocomposites showed high rate capability and superior cycling stability with specific capacity of 500 mAh g-1 for up to 300 cycles. The CNTs served as electron conductors and volume buffers in the nanocomposites. This strategy could be extended to synthesize other metal oxides composites with other carbon materials.

  14. Carbonaceous materials as lithium intercalation anodes

    SciTech Connect

    Tran, T.D.; Feikert, J.H.; Mayer, S.T.; Song, X.; Kinoshita, K.

    1994-10-01

    Commercial and polymer-derived carbonaceous materials were examined as lithium intercalation anodes in propylene carbonate (pyrolysis < 1350C, carbons) and ethylene carbonate/dimethyl carbonate (graphites) electrolytes. The reversible capacity (180--355 mAh/g) and the irreversible capacity loss (15--200 % based on reversible capacity) depend on the type of binder, carbon type, morphology, and phosphorus doping concentration. A carbon-based binder was chosen for electrode fabrication, producing mechanically and chemically stable electrodes and reproducible results. Several types of graphites had capacity approaching LiC{sub 6}. Petroleum fuel green cokes doped with phosphorous gave more than a 20 % increase in capacity compared to undoped samples. Electrochemical characteristics are related to SEM, TEM, XRD and BET measurements.

  15. Carbon nanotube-based glucose oxidase nanocomposite anode materials for bio-fuel cells

    NASA Astrophysics Data System (ADS)

    Dudzik, Jonathan

    The field of nanotechnology has benefited medicine, science, and engineering. The advent of Carbon Nanotubes (CNTs) and protein-inorganic interfacing have received much attention due to their unique nanostructures which can be modified to act as a scaffold to house proteins or create nanowires. The current trend incorporates the robustness and specificity characteristics of proteins to the mechanical strength, enlarged surface area, and conductive capabilities emblematic of their inorganic counterparts. Bio-Fuel Cells (BFCs) and Biosensors remain at the forefront and devices such as implantable glucose monitors are closer to realization than ever before. This research strives to exploit potential energy from the eukaryotic enzyme Glucose Oxidase (GOx) during oxidation of its substrate, glucose. During this process, a two-electron transfer occurs at its two FAD redox centres which can be harnessed via an electrochemical setup involving a Multi-Walled Carbon Nanotube (MWCNTs) modified electrode. The objective is to develop a MWCNT-GOx bionanocomposite capable of producing and sustaining a competitive power output. To help with this aim, investigation into a crosslinked enzyme cluster (CEC) immobilization technique is envisioned to amplify power output due to its highly concentrated, reusable, and thermally stable characteristics. Numerous CEC-GOx-MWCNT composites were fabricated with the highest initial output reaching 170 muW/cm 2. It was hypothesized that the carbohydrate moiety increased tunnelling distance and therefore hindered electron transfer. Efforts to produce a recombinant GOx without the encumbrance were unsuccessful. Two sub-clone constructs were explored and although a recombinant protein was identified, it was not confirmed to be GOx. BFC testing on bionanocomposites integrating non-glycosylated GOx could not be performed although there remains a strong contention that the recombinant would demonstrate superior power densities in comparison to its

  16. Hierarchical Carbon with High Nitrogen Doping Level: A Versatile Anode and Cathode Host Material for Long-Life Lithium-Ion and Lithium-Sulfur Batteries.

    PubMed

    Reitz, Christian; Breitung, Ben; Schneider, Artur; Wang, Di; von der Lehr, Martin; Leichtweiss, Thomas; Janek, Jürgen; Hahn, Horst; Brezesinski, Torsten

    2016-04-27

    Nitrogen-rich carbon with both a turbostratic microstructure and meso/macroporosity was prepared by hard templating through pyrolysis of a tricyanomethanide-based ionic liquid in the voids of a silica monolith template. This multifunctional carbon not only is a promising anode candidate for long-life lithium-ion batteries but also shows favorable properties as anode and cathode host material owing to a high nitrogen content (>8% after carbonization at 900 °C). To demonstrate the latter, the hierarchical carbon was melt-infiltrated with sulfur as well as coated by atomic layer deposition (ALD) of anatase TiO2, both of which led to high-quality nanocomposites. TiO2 ALD increased the specific capacity of the carbon while maintaining high Coulombic efficiency and cycle life: the composite exhibited stable performance in lithium half-cells, with excellent recovery of low rate capacities after thousands of cycles at 5C. Lithium-sulfur batteries using the sulfur/carbon composite also showed good cyclability, with reversible capacities of ∼700 mA·h·g(-1) at C/5 and without obvious decay over several hundred cycles. The present results demonstrate that nitrogen-rich carbon with an interconnected multimodal pore structure is very versatile and can be used as both active and inactive electrode material in high-performance lithium-based batteries. PMID:26867115

  17. Hydrothermal synthesis of manganese oxides/carbon nanotubes composites as anode materials for lithium ion batteries

    SciTech Connect

    Xu, Shou-Dong; Zhu, Ya-Bo; Zhuang, Quan-Chao; Wu, Chao

    2013-09-01

    Graphical abstract: Carbon nanotubes in the composites not only accommodate the volume change during charge/discharge processes, but also provide a good electron conducting network at high power rates, resulting in high reversible capacity of the electrodes. - Highlights: • MnO/CNTs composites are obtained by heating Mn{sub 3}O{sub 4}/CNTs at 500 °C for 3 h in flowing Ar/H{sub 2}. • MnO/CNTs electrode exhibits higher specific capacity at the current density of 100 mAh g{sup −1} and a better cycle performance. • Enhancement of cyclability of MnO/CNTs electrode can be attributed to the presence of CNTs in the composites. - Abstract: Mn{sub 3}O{sub 4} nanoparticles and Mn{sub 3}O{sub 4}/carbon nanotubes (CNTs) composites are prepared via a hydrothermal synthesis method. MnO and MnO/CNTs composites are obtained by heating Mn{sub 3}O{sub 4} and Mn{sub 3}O{sub 4}/CNTs at 500 for 3 h in flowing Ar/H{sub 2}. The phase structure, composition and morphology of the composites are characterized by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM). The electrochemical properties of the composite electrodes are studied by performing cyclic voltammetry (CV), galvanostatic charge and discharge tests. The results reveal that the Mn{sub 3}O{sub 4}/CNTs and MnO/CNTs electrodes exhibit higher specific capacity at the current density of 100 mAh g{sup −1} and a better cycle performance than pure Mn{sub 3}O{sub 4} and MnO electrodes. The excellent electrochemical properties of Mn{sub 3}O{sub 4}/CNTs and MnO/CNTs electrodes can be attributed to the presence of CNTs in the composites offering an electron conducting network and suppressing the volume expansion of Mn{sub 3}O{sub 4} and MnO particles efficiently during the charge and discharge processes.

  18. Improved Carbon Anodes For Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Huang, Chen-Kuo; Surampudi, Subbarao; Attia, Alan; Halpert, Gerald

    1994-01-01

    Carbon anodes for rechargeable lithium cells improved by choosing binder contents and fabrication conditions to achieve maximum porosity, uniform loading, and maximum reversible lithium capacity. Stacking electrodes under pressure during assembly of cells increases cyclability of lithium. Rechargeable, high-energy-density lithium cells containing improved carbon anodes find use in spacecraft, military, communications, automotive, and other demanding applications.

  19. Facile synthesis of α-Fe2O3 nanoparticles on porous human hair-derived carbon as improved anode materials for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Dong, Hui; Zhang, Huang; Xu, Yunlong; Zhao, Chongjun

    2015-12-01

    A hybridized composite material of α-Fe2O3 nanoparticles/human hair-derived carbon (HHC) is prepared using a facile two-step method combined carbonization of human hair with homogeneous precipitation under microwave irradiation. Results show that the uniform α-Fe2O3 nanoparticles were highly dispersed on the surface of porous human hair-derived carbon. As an anode material for Li-ion batteries, it retains a reversible capacity of 1000 mAh g-1after 200 cycles at 0.2 C. A discharge capacity higher than 750 mAh g-1and 550 mAh g-1 is also recorded at 1 C and 2 C after 200 cycles, respectively. Such superior electrochemical performance of α-Fe2O3/HHC composite could be attributed to the favorable structure of HHC, which can improve the electron and lithium ion transport ability as anode. This study provides a cost-effective, highly efficient means to fabricate materials which combine keratin wastes-derived carbon with active nanoparticles for the development of high-performance lithium-ion battery materials.

  20. Synthesis and Application of Si/Carbon Nanofiber Composites Based on Ni and Mo Catalysts for Anode Material of Lithium Secondary Batteries.

    PubMed

    Jang, Eunyi; Park, Heal-Ku; Lee, Chang-Seop

    2016-05-01

    In this paper, carbon nanofibers (CNFs) and Si/carbon nanofiber composites were synthesized for use as the anode material of lithium secondary batteries. Catalysts were prepared based on Ni and Mo metals and CNFs were grown through chemical vapor deposition (CVD). In addition, the grown CNFs were mixed with silicon particles to synthesize Si/carbon nanofibers composites. The physiochemical characteristics of the synthesized CNFs and Si/carbon nanofiber composites were analyzed by SEM, EDS, XRD, Raman, BET and XPS. The electrochemical characteristics were investigated by using cyclic voltammetry and galvanostatic charge-discharge. Using CNFs and Si/carbon nanofiber composites as the anode material, three electrode cells were assembled and the electrochemical characteristics were measured using LiPF6 and LiClO4 as electrolytes. As a result of the galvanostatic charge-discharge of CNFs that were grown through catalysts with Ni and Mo concentration ratio of 6:4, the initial discharge capacity when using LiPF6 as the electrolyte was 570 mAh/g and the retention rate was 15.05%. In the case of using LiClO4 as the electrolyte, the initial discharge capacity was 263 mAh/g and the retention rate was 67.23%. PMID:27483824

  1. Materials characterization of cermet anodes tested in a pilot cell

    SciTech Connect

    Windisch, C.F. Jr.; Strachan, D.M.; Henager, C.H. Jr. ); Alcorn, T.R.; Tabereaux, A.T.; Richards, N.E. . Mfg. Technology Lab.)

    1993-02-01

    Cermet anodes were evaluated as nonconsumable substitutes for carbon anodes using a pilot-scale reduction cell at the Reynolds Manufacturing Technology Laboratory. After pilot cell testing, tile anodes were subjected to extensive materials characterization and physical properties measurements at the Pacific Northwest Laboratory. Significant changes in the composition of the cermet anodes were observed including the growth of a reaction layer and penetration of electrolyte deep into the cermet matrix. Fracture strength and toughness were measured as a function of temperature and the ductile-brittle transition wasreduced by 500C following pilot cell testing. These results imply difficulties with anode material and control of operating conditions in the pilot cell, and suggest that additional development work be performed before the cermet anodes are used in commercial reduction cells. The results also highlight specific fabrication and operational considerations that should be addressed in future testing.

  2. Three-dimensional tin dioxide/carbon composite constructed by hollow nanospheres with quasi-sandwich structures as improved anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Tian, Qinghua; Tian, Yang; Zhang, Zhengxi; Yang, Li; Hirano, Shin-ichi

    2016-02-01

    Tin dioxide (SnO2)-based materials have been considered to be promisingly alternative advanced anode materials for lithium-ion batteries and thus attracted wide attention. So far, the research focus of SnO2-based anode materials is to search and develop effective strategies for overcoming the obstacles, such as rapid capacity fading and poor rate capability, which seriously impede the practical application of SnO2-based electrodes. Herein, we have successfully combined nanoscale SnO2 with 3-dimensional carbon (C) conductivity framework to form a 3-dimensional unparalleled SnO2/C composite constructed by closely interconnected hollow nanospheres with quasi-sandwich structures. When evaluated as anode materials for lithium-ion batteries, the as-prepared SnO2/C composite exhibits improved cycling performance and high rate capability, delivering a high capacity of 576.6 mAh g-1 at 200 mA g-1 even after 500 cycles, and a capacity of 411.7 mAh g-1 even at 5 A g-1 during rate test. The unparalleled 3-dimensional architecture should be responsible for the good electrochemical performance.

  3. Biomass carbon micro/nano-structures derived from ramie fibers and corncobs as anode materials for lithium-ion and sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Jiang, Qiang; Zhang, Zhenghao; Yin, Shengyu; Guo, Zaiping; Wang, Shiquan; Feng, Chuanqi

    2016-08-01

    Three-dimensional (3D) rod-like carbon micro-structures derived from natural ramie fibers and two-dimensional (2D) carbon nanosheets derived from corncobs have been fabricated by heat treatment at 700 °C under argon atomsphere. The structure and morphology of the as-obtained ramie fiber carbon (RFC) and corncob carbon (CC) were characterized by X-ray diffraction (XRD), Raman spectroscopy, scanning electron microscopy (SEM) and transmission electron microscopy (TEM) technique. The electrochemical performances of the biomass carbon-based anode in lithium-ion batteries (LIBs) and sodium-ion batteries (SIBs) were investigated. When tested as anode material for lithium ion batteries, both the RFC microrods and CC nanosheets exhibited high capacity, excellent rate capability, and stable cyclability. The specific capacity were still as high as 489 and 606 mAhg-1 after 180 cycles when cycled at room temperature in a 3.0-0.01 V potential (vs. Li/Li+) window at current density of 100 mAg-1, respectively, which are much higher than that of graphite (375 mAhg-1) under the same current density. Although the anodes in sodium ion batteries showed poorer specific capability than that in lithium-ion batteries, they still achieve a reversible sodium intercalation capacity of 122 and 139 mAhg-1 with similar cycling stability. The feature of stable cycling performance makes the biomass carbon derived from natural ramie fibers and corncobs to be promising candidates as electrodes in rechargeable sodium-ion batteries and lithium-ion batteries.

  4. Anodized Ti3SiC2 As an Anode Material for Li-ion Microbatteries.

    PubMed

    Tesfaye, Alexander T; Mashtalir, Olha; Naguib, Michael; Barsoum, Michel W; Gogotsi, Yury; Djenizian, Thierry

    2016-07-01

    We report on the synthesis of an anode material for Li-ion batteries by anodization of a common MAX phase, Ti3SiC2, in an aqueous electrolyte containing hydrofluoric acid (HF). The anodization led to the formation of a porous film containing anatase, a small quantity of free carbon, and silica. By varying the anodization parameters, various oxide morphologies were produced. The highest areal capacity was achieved by anodization at 60 V in an aqueous electrolyte containing 0.1 v/v HF for 3 h at room temperature. After 140 cycles performed at multiple applied current densities, an areal capacity of 380 μAh·cm(-2) (200 μA·cm(-2)) has been obtained, making this new material, free of additives and binders, a promising candidate as a negative electrode for Li-ion microbatteries. PMID:27282275

  5. Multiwalled carbon nanotube@a-C@Co9S8 nanocomposites: a high-capacity and long-life anode material for advanced lithium ion batteries.

    PubMed

    Zhou, Yanli; Yan, Dong; Xu, Huayun; Liu, Shuo; Yang, Jian; Qian, Yitai

    2015-02-28

    A one-dimensional MWCNT@a-C@Co9S8 nanocomposite has been prepared via a facile solvothermal reaction followed by a calcination process. The amorphous carbon layer between Co9S8 and MWCNT acts as a linker to increase the loading of sulfides on MWCNT. When evaluated as anode materials for lithium ion batteries, the MWCNT@a-C@Co9S8 nanocomposite shows the advantages of high capacity and long life, superior to Co9S8 nanoparticles and MWCNT@Co9S8 nanocomposites. The reversible capacity could be retained at 662 mA h g(-1) after 120 cycles at 1 A g(-1). The efficient synthesis and excellent performances of this nanocomposite offer numerous opportunities for other sulfides as a new anode for lithium ion batteries. PMID:25629465

  6. In Situ Synthesis and Characterization of Ge Embedded Electrospun Carbon Nanostructures as High Performance Anode Material for Lithium-Ion Batteries.

    PubMed

    Lee, Young-Woo; Kim, Da-Mi; Kim, Si-Jin; Kim, Min-Cheol; Choe, Hui-Seon; Lee, Kyu-Ho; Sohn, Jung Inn; Cha, Seung Nam; Kim, Jong Min; Park, Kyung-Won

    2016-03-23

    While active materials based on germanium (Ge) are considered as a promising alternative anodic electrode due to their relatively high reversible capacity and excellent lithium-ion diffusivity, the quite unstable structural/electrochemical stability and severe volume expansion or pulverization problems of Ge electrodes remain a considerable challenge in lithium ion batteries (LIBs). Here, we present the development of Ge embedded in one-dimensional carbon nanostructures (Ge/CNs) synthesized by the modified in situ electrospinning technique using a mixed electrospun solution consisting of a Ge precursor as an active material source and polyacrylonitrile (PAN) as a carbon source. The as-prepared Ge/CNs exhibit superior lithium ion behavior properties, i.e., highly reversible specific capacity, rate performance, Li ion diffusion coefficient, and superior cyclic stability (capacity retention: 85% at 200 mA g(-1)) during Li alloying/dealloying processes. These properties are due to the high electrical conductivity and unique structures containing well-embedded Ge nanoparticles (NPs) and a one-dimensional carbon nanostructure as a buffer medium, which is related to the volume expansion of Ge NPs. Thus, it is expected that the Ge/CNs can be utilized as a promising alternative anodic material in LIBs. PMID:26895137

  7. Characteristics and Electrochemical Performance of Si-Carbon Nanofibers Composite as Anode Material for Binder-Free Lithium Secondary Batteries.

    PubMed

    Hyun, Yura; Park, Heai-Ku; Park, Ho-Seon; Lee, Chang-Seop

    2015-11-01

    The carbon nanofibers (CNFs) and Si-CNFs composite were synthesized using a chemical vapor deposition (CVD) method with an iron-copper catalyst and silicon-covered Ni foam. Acetylene as a carbon source was flowed into the quartz reactor of a tubular furnace heated to 600 degrees C. This temperature was maintained for 10 min to synthesize the CNFs. The morphologies, compositions, and crystal quality of the prepared CNFs were characterized by Scanning electron microscopy (SEM), Energy dispersive spectroscopy (EDS), X-ray Diffraction (XRD), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The electrochemical characteristics of the Si-CNFs composite as an anode of the Li secondary batteries were investigated using a three-electrode cell. The as-deposited Si-CNF composite on the Ni foam was directly employed as an working electrode without any binder, and lithium foil was used as the counter and reference electrode. A glass fiber separator was used as the separator membrane. Two kinds of electrolytes were employed; 1) 1 M LiPF6 was dissolved in a mixture of EC (ethylene carbonate): PC (propylene carbonate): EMC (Ethyl methyl carbonate) in a 1:1:1 volume ratio and 2) 1 M LiClO4 was dissolved in a mixture of propylene carbonate (PC): ethylene carbonate (EC) in a 1:1 volume ratio. The galvanostatic charge-discharge cycling and cyclic voltammetry measurements were carried out at room temperature by using a battery tester. The resulting Si-CNFs composite achieved the large discharge capacity of 613 mAh/g and much improved cycle-ability with the retention rate of 87% after 20 cycles. PMID:26726625

  8. Synthesis of SnO2 pillared carbon using long chain alkylamine grafted graphene oxide: an efficient anode material for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Reddy, M. Jeevan Kumar; Ryu, Sung Hun; Shanmugharaj, A. M.

    2015-12-01

    With the objective of developing new advanced composite materials that can be used as anodes for lithium ion batteries (LIBs), herein we describe the synthesis of SnO2 pillared carbon using various alkylamine (hexylamine; dodecylamine and octadecylamine) grafted graphene oxides and butyl trichlorotin precursors followed by its calcination at 500 °C for 2 h. While the grafted alkylamine induces crystalline growth of SnO2 pillars, thermal annealing of alkylamine grafted graphene oxide results in the formation of amorphous carbon coated graphene. Field emission scanning electron microscopy (FE-SEM) results reveal the successful formation of SnO2 pillared carbon on the graphene surface. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy characterization corroborates the formation of rutile SnO2 crystals on the graphene surface. A significant rise in the BET surface area is observed for SnO2 pillared carbon, when compared to pristine GO. Electrochemical characterization studies of SnO2 pillared carbon based anode materials showed an enhanced lithium storage capacity and fine cyclic performance in comparison with pristine GO. The initial specific capacities of SnO2 pillared carbon are observed to be 1379 mA h g-1, 1255 mA h g-1 and 1360 mA h g-1 that decrease to 750 mA h g-1, 643 mA h g-1 and 560 mA h g-1 depending upon the chain length of grafted alkylamine on the graphene surface respectively. Electrochemical impedance spectral analysis reveals that the exchange current density of SnO2 pillared carbon based electrodes is higher, corroborating its enhanced electrochemical activity in comparison with GO based electrodes.With the objective of developing new advanced composite materials that can be used as anodes for lithium ion batteries (LIBs), herein we describe the synthesis of SnO2 pillared carbon using various alkylamine (hexylamine; dodecylamine and octadecylamine) grafted graphene oxides and butyl trichlorotin precursors

  9. Synthesis of SnO2 pillared carbon using long chain alkylamine grafted graphene oxide: an efficient anode material for lithium ion batteries.

    PubMed

    Reddy, M Jeevan Kumar; Ryu, Sung Hun; Shanmugharaj, A M

    2016-01-01

    With the objective of developing new advanced composite materials that can be used as anodes for lithium ion batteries (LIBs), herein we describe the synthesis of SnO2 pillared carbon using various alkylamine (hexylamine; dodecylamine and octadecylamine) grafted graphene oxides and butyl trichlorotin precursors followed by its calcination at 500 °C for 2 h. While the grafted alkylamine induces crystalline growth of SnO2 pillars, thermal annealing of alkylamine grafted graphene oxide results in the formation of amorphous carbon coated graphene. Field emission scanning electron microscopy (FE-SEM) results reveal the successful formation of SnO2 pillared carbon on the graphene surface. X-ray diffraction (XRD), transmission electron microscopy (TEM) and Raman spectroscopy characterization corroborates the formation of rutile SnO2 crystals on the graphene surface. A significant rise in the BET surface area is observed for SnO2 pillared carbon, when compared to pristine GO. Electrochemical characterization studies of SnO2 pillared carbon based anode materials showed an enhanced lithium storage capacity and fine cyclic performance in comparison with pristine GO. The initial specific capacities of SnO2 pillared carbon are observed to be 1379 mA h g(-1), 1255 mA h g(-1) and 1360 mA h g(-1) that decrease to 750 mA h g(-1), 643 mA h g(-1) and 560 mA h g(-1) depending upon the chain length of grafted alkylamine on the graphene surface respectively. Electrochemical impedance spectral analysis reveals that the exchange current density of SnO2 pillared carbon based electrodes is higher, corroborating its enhanced electrochemical activity in comparison with GO based electrodes. PMID:26628211

  10. Amorphous silicon-carbon nanospheres synthesized by chemical vapor deposition using cheap methyltrichlorosilane as improved anode materials for Li-ion batteries.

    PubMed

    Zhang, Zailei; Zhang, Meiju; Wang, Yanhong; Tan, Qiangqiang; Lv, Xiao; Zhong, Ziyi; Li, Hong; Su, Fabing

    2013-06-21

    We report the preparation and characterization of amorphous silicon-carbon (Si-C) nanospheres as anode materials in Li-ion batteries. These nanospheres were synthesized by a chemical vapor deposition at 900 °C using methyltrichlorosilane (CH3SiCl3) as both the Si and C precursor, which is a cheap byproduct in the organosilane industry. The samples were characterized by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, nitrogen adsorption, thermal gravimetric analysis, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the synthesized Si-C nanospheres composed of amorphous C (about 60 wt%) and Si (about 40 wt%) had a diameter of 400-600 nm and a surface area of 43.8 m(2) g(-1). Their charge capacities were 483.6, 331.7, 298.6, 180.6, and 344.2 mA h g(-1) at 50, 200, 500, 1000, and 50 mA g(-1) after 50 cycles, higher than that of the commercial graphite anode. The Si-C amorphous structure could absorb a large volume change of Si during Li insertion and extraction reactions and hinder the cracking or crumbling of the electrode, thus resulting in the improved reversible capacity and cycling stability. The work opens a new way to fabricate low cost Si-C anode materials for Li-ion batteries. PMID:23652614

  11. Lithium intercalation in porous carbon anodes

    SciTech Connect

    Tran, T.D.; Pekala, R.W.; Mayer, S.T.

    1994-11-23

    Carbon foams derived from the phase separation of polyacrylonitrile/solvent mixtures were investigated as lithium intercalation anodes for rechargeable lithium-ion batteries. The carbon foams have a bulk density of 0.35--0.5 g/cm{sup 3}, low surface area (< 50 m{sup 2}/g), and an average cell size of 5--10 {mu}m. Polyacrylonitrile-based carbon foams doped with phosphoric acid had capacity as high as 450 mAh/g. Carbon capacity increased with increasing phosphoric acid concentration in the doping solution. The doped porous carbon anodes exhibited good cyclability and excellent coulombic efficiency.

  12. Tin nanoparticles encapsulated in porous multichannel carbon microtubes: preparation by single-nozzle electrospinning and application as anode material for high-performance Li-based batteries.

    PubMed

    Yu, Yan; Gu, Lin; Zhu, Changbao; van Aken, Peter A; Maier, Joachim

    2009-11-11

    Tin nanoparticles encapsulated in porous multichannel carbon microtubes (denoted as SPMCTs) were prepared by carbonization of electrospun PAN-PMMA-tin octoate nanofibers fabricated using a single-nozzle electrospinning technique. This material exhibited excellent characteristics for lithium ion battery anode applications in terms of reversible capacities, cycling performance, and rate capability. Undertaking such a production configuration allows the long-existing problem of obtaining a high packing density of tin particles while retaining sufficient spare space to buffer the volume variation during lithium alloying and dealloying processes to be properly addressed. Furthermore, the porous carbon shell preserves both the mechanical and chemical stability of the function-active Sn metal, which also serves as a highly conductive medium allowing Li(+) to access. PMID:19886691

  13. Encapsulation of MnO Nanocrystals in Electrospun Carbon Nanofibers as High-Performance Anode Materials for Lithium-Ion Batteries

    PubMed Central

    Liu, Bin; Hu, Xianluo; Xu, Henghui; Luo, Wei; Sun, Yongming; Huang, Yunhui

    2014-01-01

    A novel and controllable approach is developed for the synthesis of MnO nanocrystals embedded in carbon nanofibers (MnO/CNFs) through an electrospinning process. The as-formed MnO/CNFs have a porous structure with diameters of 100–200 nm and lengths up to several millimeters. When used as an anode material for lithium-ion batteries, the resulting MnO/CNFs exhibit superior electrochemical performances with high specific capacity, good cyclability, and excellent rate capability. The unique porous carbon nanofibers (PCNFs) can not only improve the contact area between the electrode and the electrolyte, but also alleviate the impact of the large volume effect of MnO during the electrochemical cycling. It is expected that the present synthetic strategy can be extended to synthesize other nanostructured oxides encapsulated in carbon nanofibers for extensive energy transfer and storage applications. PMID:24598639

  14. Anode Sheath Switching in a Carbon Nanotube Arc Plasma

    SciTech Connect

    Abe Fetterman, Yevgeny Raitses, and Michael Keidar

    2008-04-08

    The anode ablation rate is investigated as a function of anode diameter for a carbon nanotube arc plasma. It is found that anomalously high ablation occurs for small anode diameters. This result is explained by the formation of a positive anode sheath. The increased ablation rate due to this positive anode sheath could imply greater production rate for carbon nanotubes.

  15. Multiwalled carbon nanotube@a-C@Co9S8 nanocomposites: a high-capacity and long-life anode material for advanced lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zhou, Yanli; Yan, Dong; Xu, Huayun; Liu, Shuo; Yang, Jian; Qian, Yitai

    2015-02-01

    A one-dimensional MWCNT@a-C@Co9S8 nanocomposite has been prepared via a facile solvothermal reaction followed by a calcination process. The amorphous carbon layer between Co9S8 and MWCNT acts as a linker to increase the loading of sulfides on MWCNT. When evaluated as anode materials for lithium ion batteries, the MWCNT@a-C@Co9S8 nanocomposite shows the advantages of high capacity and long life, superior to Co9S8 nanoparticles and MWCNT@Co9S8 nanocomposites. The reversible capacity could be retained at 662 mA h g-1 after 120 cycles at 1 A g-1. The efficient synthesis and excellent performances of this nanocomposite offer numerous opportunities for other sulfides as a new anode for lithium ion batteries.A one-dimensional MWCNT@a-C@Co9S8 nanocomposite has been prepared via a facile solvothermal reaction followed by a calcination process. The amorphous carbon layer between Co9S8 and MWCNT acts as a linker to increase the loading of sulfides on MWCNT. When evaluated as anode materials for lithium ion batteries, the MWCNT@a-C@Co9S8 nanocomposite shows the advantages of high capacity and long life, superior to Co9S8 nanoparticles and MWCNT@Co9S8 nanocomposites. The reversible capacity could be retained at 662 mA h g-1 after 120 cycles at 1 A g-1. The efficient synthesis and excellent performances of this nanocomposite offer numerous opportunities for other sulfides as a new anode for lithium ion batteries. Electronic supplementary information (ESI) available: Infrared spectrogram (IR) of glucose treated MWCNT; TEM images of MWCNT@a-C treated by different concentrations of glucose; SEM and TEM images of the intermediate product obtained from the solvothermal reaction between thiourea and Co(Ac)2; EDS spectrum of MWCNT@a-C@Co9S8 composites; SEM and TEM images of MWCNT@Co9S8 nanocomposites obtained without the hydrothermal treatment by glucose; SEM and TEM images of Co9S8 nanoparticles; Galvanostatic discharge-charge profiles and cycling performance of MWCNT@a-C; TEM images

  16. Silicon Whisker and Carbon Nanofiber Composite Anode

    NASA Technical Reports Server (NTRS)

    Ma, Junqing (Inventor); Newman, Aron (Inventor); Lennhoff, John (Inventor)

    2015-01-01

    A carbon nanofiber can have a surface and include at least one crystalline whisker extending from the surface of the carbon nanofiber. A battery anode composition can be formed from a plurality of carbon nanofibers each including a plurality of crystalline whiskers.

  17. Hard carbon nanoparticles as high-capacity, high-stability anodic materials for Na-ion batteries

    SciTech Connect

    Xiao, Lifen; Cao, Yuliang; Henderson, Wesley A.; Sushko, Maria L.; Shao, Yuyan; Xiao, Jie; Wang, Wei; Engelhard, Mark H.; Nie, Zimin; Liu, Jun

    2016-01-01

    Hard carbon nanoparticles (HCNP) were synthesized by the pyrolysis of a polyaniline precursor. The measured Na+ cation diffusion coefficient (10-13-10-15cm2s-1) in the HCNP obtained at 1150 °C is two orders of magnitude lower than that of Li+ in graphite (10-10-13-15cm2s-1), indicating that reducing the carbon particle size is very important for improving electrochemical performance. These measurements also enable a clear visualization of the stepwise reaction phases and rate changes which occur throughout the insertion/extraction processes in HCNP, The electrochemical measurements also show that the nano-sized HCNP obtained at 1150 °C exhibited higher practical capacity at voltages lower than 1.2 V (vs. Na/Na⁺), as well as a prolonged cycling stability, which is attributed to an optimum spacing of 0.366 nm between the graphitic layers and the nano particular size resulting in a low-barrier Na+ cation insertion. These results suggest that HCNP is a very promising high-capacity/stability anode for low cost sodium-ion batteries (SIBs).

  18. Preparation of a Binder-Free Three-Dimensional Carbon Foam/Silicon Composite as Potential Material for Lithium Ion Battery Anodes.

    PubMed

    Roy, Amit K; Zhong, Mingjie; Schwab, Matthias Georg; Binder, Axel; Venkataraman, Shyam S; Tomović, Željko

    2016-03-23

    We report a novel three-dimensional nitrogen containing carbon foam/silicon (CFS) composite as potential material for lithium ion battery anodes. Carbon foams were prepared by direct carbonization of low cost, commercially available melamine formaldehyde (MF, Basotect) foam precursors. The carbon foams thus obtained display a three-dimensional interconnected macroporous network structure with good electrical conductivity (0.07 S/cm). Binder free CFS composites used for electrodes were prepared by immersing the as-fabricated carbon foam into silicon nanoparticles dispersed in ethanol followed by solvent evaporation and secondary pyrolysis. In order to substantiate this new approach, preliminary electrochemical testing has been done. The first results on CFS electrodes demonstrated initial capacity of 1668 mAh/g with 75% capacity retention after 30 cycles of subsequent charging and discharging. In order to further enhance the electrochemical performance, silicon nanoparticles were additionally coated with a nitrogen containing carbon layer derived from codeposited poly(acrylonitrile). These carbon coated CFS electrodes demonstrated even higher performance with an initial capacity of 2100 mAh/g with 92% capacity retention after 30 cycles of subsequent charging and discharging. PMID:26909748

  19. Encapsulation of α-Fe2O3 nanoparticles in graphitic carbon microspheres as high-performance anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Hongwei; Sun, Xiaoran; Huang, Xiaodan; Zhou, Liang

    2015-02-01

    A novel ``spray drying-carbonization-oxidation'' strategy has been developed for the fabrication of α-Fe2O3-graphitic carbon (α-Fe2O3@GC) composite microspheres, in which α-Fe2O3 nanoparticles with sizes of 30-50 nm are well-encapsulated by onion-like graphitic carbon shells with a thickness of 5-10 nm. In the constructed composite, the α-Fe2O3 nanoparticles act as the primary active material, providing a high capacity. Meanwhile, the graphitic carbon shells serve as the secondary active component, structural stabilizer, interfacial stabilizer, and electron-highway. As a result, the synthesized α-Fe2O3@GC nanocomposite exhibits a superior lithium-ion battery performance with a high reversible capacity (898 mA h g-1 at 400 mA g-1), outstanding rate capability, and excellent cycling stability. Our product, in terms of the facile and scalable preparation process and excellent electrochemical performance, demonstrates its great potential as a high-performance anode material for lithium-ion batteries.A novel ``spray drying-carbonization-oxidation'' strategy has been developed for the fabrication of α-Fe2O3-graphitic carbon (α-Fe2O3@GC) composite microspheres, in which α-Fe2O3 nanoparticles with sizes of 30-50 nm are well-encapsulated by onion-like graphitic carbon shells with a thickness of 5-10 nm. In the constructed composite, the α-Fe2O3 nanoparticles act as the primary active material, providing a high capacity. Meanwhile, the graphitic carbon shells serve as the secondary active component, structural stabilizer, interfacial stabilizer, and electron-highway. As a result, the synthesized α-Fe2O3@GC nanocomposite exhibits a superior lithium-ion battery performance with a high reversible capacity (898 mA h g-1 at 400 mA g-1), outstanding rate capability, and excellent cycling stability. Our product, in terms of the facile and scalable preparation process and excellent electrochemical performance, demonstrates its great potential as a high-performance anode

  20. High capacity anode materials for lithium ion batteries

    SciTech Connect

    Lopez, Herman A.; Anguchamy, Yogesh Kumar; Deng, Haixia; Han, Yongbon; Masarapu, Charan; Venkatachalam, Subramanian; Kumar, Suject

    2015-11-19

    High capacity silicon based anode active materials are described for lithium ion batteries. These materials are shown to be effective in combination with high capacity lithium rich cathode active materials. Supplemental lithium is shown to improve the cycling performance and reduce irreversible capacity loss for at least certain silicon based active materials. In particular silicon based active materials can be formed in composites with electrically conductive coatings, such as pyrolytic carbon coatings or metal coatings, and composites can also be formed with other electrically conductive carbon components, such as carbon nanofibers and carbon nanoparticles. Additional alloys with silicon are explored.

  1. Aerogel and xerogel composites for use as carbon anodes

    DOEpatents

    Cooper, John F.; Tillotson, Thomas M.; Hrubesh, Lawrence W.

    2008-08-12

    Disclosed herein are aerogel and xerogel composite materials suitable for use as anodes in fuel cells and batteries. Precursors to the aerogel and xerogel compounds are infused with inorganic polymeric materials or carbon particles and then gelled. The gels are then pyrolyzed to form composites with internal structural support.

  2. Efficient exfoliation N-doped graphene from N-containing bamboo-like carbon nanotubes for anode materials of Li-ion battery and Na-ion battery

    NASA Astrophysics Data System (ADS)

    Feng, Jian-Min; Dong, Lei; Han, Yan; Li, Xi-Fei; Li, De-Jun

    2015-08-01

    Nanosize N-doped graphene is prepared from N-containing carbon nanotubes (CNTs) by chemical exfoliation. The CNTs adopted for graphene are characterized by a discontinuous wall that consists of nanosize graphite layers, exhibiting a bamboo-like appearance. Take advantage of this characterization, the most time-consuming process of chemical oxidation that involves intercalation in graphene from CNT has been markedly reduced. The reduction in processing time is attributed to the diffusion distance of chemical oxidation intercalation into nanosize graphite composed of a bamboo-like carbon nanotube (BCNT) wall being far less than that of conventional chemical exfoliation into microsize graphite. The as-prepared nanosize N-doped graphene from BCNTs has shown an excellent electrochemical performance for Li-ion battery and Na-ion battery anode materials.

  3. Anode materials for electrochemical waste destruction

    NASA Technical Reports Server (NTRS)

    Molton, Peter M.; Clarke, Clayton

    1990-01-01

    Electrochemical Oxidation (ECO) offers promise as a low-temperature, atmospheric pressure method for safe destruction of hazardous organic chemical wastes in water. Anode materials tend to suffer corrosion in the intensely oxidizing environment of the ECO cell. There is a need for cheaper, more resistant materials. In this experiment, a system is described for testing anode materials, with examples of several common anodes such as stainless steel, graphite, and platinized titanium. The ECO system is simple and safe to operate and the experiment can easily be expanded in scope to study the effects of different solutions, temperatures, and organic materials.

  4. Enhanced electrochemical performance of template-free carbon-coated iron(II, III) oxide hollow nanofibers as anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Im, Mi Eun; Pham-Cong, De; Kim, Ji Yoon; Choi, Hun Seok; Kim, Jae Hyun; Kim, Jong Pil; Kim, Jinwoo; Jeong, Se Young; Cho, Chae Ryong

    2015-06-01

    Carbon-coated Fe3O4 hollow nanofibers (Fe3O4/C hNFs) as a lithium ion battery anode material are prepared through electrospinning, annealing, and hydrothermal processing. At a high current density of 1000 mAg-1, the template-free Fe3O4/C hNFs exhibit high 1st- and 150th-cycle specific capacities of ∼963 and 978 mAhg-1, respectively. Moreover, Fe3O4/C hNFs have excellent and stable rate capability, compared to that of the Fe3O4 hNFs, and a capacity of 704 mAhg-1 at a current density of 2000 mAg-1. Owing to the carbon layer, the Li-ion diffusion coefficient of the Fe3O4/C hNFs, 8.10 × 10-14 cm2 s-1, is 60 times higher than that (1.33 × 10-15 cm2 s-1) of the Fe3O4 hNFs. These results indicate that Fe3O4/C hNFs may have important implications for developing high performance anodes for next-generation lithium ion batteries.

  5. Nitrogen-doped carbon/graphene hybrid anode material for sodium-ion batteries with excellent rate capability

    NASA Astrophysics Data System (ADS)

    Liu, Huan; Jia, Mengqiu; Cao, Bin; Chen, Renjie; Lv, Xinying; Tang, Renjie; Wu, Feng; Xu, Bin

    2016-07-01

    Nitrogen-doped carbon/graphene (NCG) hybrid materials were prepared by an in-situ polymerization and followed pyrolysis for sodium-ion batteries. The NCG has a large interlayer distance (0.360 nm) and a high nitrogen content of 7.54 at%, resulting in a high reversible sodium storage capacity of 336 mAh g-1 at 30 mA g-1. The NCG shows a sandwich-like structure, i.e. nitrogen-doped carbon nanosheets closely coated on both sides of graphene. The carbon nanosheets shorten the ion diffusion distance, while the sandwiched graphene with high electronic conductivity guarantees fast electron transport, making the NCG exhibit excellent rate capability (94 mAh g-1 at 5 A g-1). It also exhibits good cycle stability with a capacity retention of 89% after 200 cycles at 50 mA g-1.

  6. High performance amorphous-Si@SiOx/C composite anode materials for Li-ion batteries derived from ball-milling and in situ carbonization

    NASA Astrophysics Data System (ADS)

    Wang, Dingsheng; Gao, Mingxia; Pan, Hongge; Wang, Junhua; Liu, Yongfeng

    2014-06-01

    Amorphous-Si@SiOx/C composites with amorphous Si particles as core and coated with a double layer of SiOx and carbon are prepared by ball-milling crystal micron-sized silicon powders and carbonization of the citric acid intruded in the ball-milled Si. Different ratios of Si to citric acid are used in order to optimize the electrochemical performance. It is found that SiOx exists naturally at the surfaces of raw Si particles and its content increases to ca. 24 wt.% after ball-milling. With an optimized Si to citric acid weight ratio of 1/2.5, corresponding to 8.4 wt.% C in the composite, a thin carbon layer is coated on the surfaces of a-Si@SiOx particles, moreover, floc-like carbon also forms and connects the carbon coated a-Si@SiOx particles. The composite provides a capacity of 1450 mA h g-1 after 100 cycles at a current density of 100 mA g1, and a capacity of 1230 mA h g-1 after 100 cycles at 500 mA g1 as anode material for lithium-ion batteries. Effects of ball-milling and the addition of citric acid on the microstructure and electrochemical properties of the composites are revealed and the mechanism of the improvement in electrochemical properties is discussed.

  7. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries

    PubMed Central

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen (David)

    2016-01-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g−1 at a current density of 0.1 A g−1, exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage. PMID:27453938

  8. Hierarchical MoS2 tubular structures internally wired by carbon nanotubes as a highly stable anode material for lithium-ion batteries.

    PubMed

    Chen, Yu Ming; Yu, Xin Yao; Li, Zhen; Paik, Ungyu; Lou, Xiong Wen David

    2016-07-01

    Molybdenum disulfide (MoS2), a typical two-dimensional material, is a promising anode material for lithium-ion batteries because it has three times the theoretical capacity of graphite. The main challenges associated with MoS2 anodes are the structural degradation and the low rate capability caused by the low intrinsic electric conductivity and large strain upon cycling. Here, we design hierarchical MoS2 tubular structures internally wired by carbon nanotubes (CNTs) to tackle these problems. These porous MoS2 tubular structures are constructed from building blocks of ultrathin nanosheets, which are believed to benefit the electrochemical reactions. Benefiting from the unique structural and compositional characteristics, these CNT-wired MoS2 tubular structures deliver a very high specific capacity of ~1320 mAh g(-1) at a current density of 0.1 A g(-1), exceptional rate capability, and an ultralong cycle life of up to 1000 cycles. This work may inspire new ideas for constructing high-performance electrodes for electrochemical energy storage. PMID:27453938

  9. Interconnected hollow carbon nanospheres for stable lithium metal anodes.

    PubMed

    Zheng, Guangyuan; Lee, Seok Woo; Liang, Zheng; Lee, Hyun-Wook; Yan, Kai; Yao, Hongbin; Wang, Haotian; Li, Weiyang; Chu, Steven; Cui, Yi

    2014-08-01

    For future applications in portable electronics, electric vehicles and grid storage, batteries with higher energy storage density than existing lithium ion batteries need to be developed. Recent efforts in this direction have focused on high-capacity electrode materials such as lithium metal, silicon and tin as anodes, and sulphur and oxygen as cathodes. Lithium metal would be the optimal choice as an anode material, because it has the highest specific capacity (3,860 mAh g(-1)) and the lowest anode potential of all. However, the lithium anode forms dendritic and mossy metal deposits, leading to serious safety concerns and low Coulombic efficiency during charge/discharge cycles. Although advanced characterization techniques have helped shed light on the lithium growth process, effective strategies to improve lithium metal anode cycling remain elusive. Here, we show that coating the lithium metal anode with a monolayer of interconnected amorphous hollow carbon nanospheres helps isolate the lithium metal depositions and facilitates the formation of a stable solid electrolyte interphase. We show that lithium dendrites do not form up to a practical current density of 1 mA cm(-2). The Coulombic efficiency improves to ∼ 99% for more than 150 cycles. This is significantly better than the bare unmodified samples, which usually show rapid Coulombic efficiency decay in fewer than 100 cycles. Our results indicate that nanoscale interfacial engineering could be a promising strategy to tackle the intrinsic problems of lithium metal anodes. PMID:25064396

  10. Interconnected hollow carbon nanospheres for stable lithium metal anodes

    NASA Astrophysics Data System (ADS)

    Zheng, Guangyuan; Lee, Seok Woo; Liang, Zheng; Lee, Hyun-Wook; Yan, Kai; Yao, Hongbin; Wang, Haotian; Li, Weiyang; Chu, Steven; Cui, Yi

    2014-08-01

    For future applications in portable electronics, electric vehicles and grid storage, batteries with higher energy storage density than existing lithium ion batteries need to be developed. Recent efforts in this direction have focused on high-capacity electrode materials such as lithium metal, silicon and tin as anodes, and sulphur and oxygen as cathodes. Lithium metal would be the optimal choice as an anode material, because it has the highest specific capacity (3,860 mAh g-1) and the lowest anode potential of all. However, the lithium anode forms dendritic and mossy metal deposits, leading to serious safety concerns and low Coulombic efficiency during charge/discharge cycles. Although advanced characterization techniques have helped shed light on the lithium growth process, effective strategies to improve lithium metal anode cycling remain elusive. Here, we show that coating the lithium metal anode with a monolayer of interconnected amorphous hollow carbon nanospheres helps isolate the lithium metal depositions and facilitates the formation of a stable solid electrolyte interphase. We show that lithium dendrites do not form up to a practical current density of 1 mA cm-2. The Coulombic efficiency improves to ˜99% for more than 150 cycles. This is significantly better than the bare unmodified samples, which usually show rapid Coulombic efficiency decay in fewer than 100 cycles. Our results indicate that nanoscale interfacial engineering could be a promising strategy to tackle the intrinsic problems of lithium metal anodes.

  11. Structural micro-porous carbon anode for rechargeable lithium-ion batteries

    DOEpatents

    Delnick, Frank M.; Even, Jr., William R.; Sylwester, Alan P.; Wang, James C. F.; Zifer, Thomas

    1995-01-01

    A secondary battery having a rechargeable lithium-containing anode, a cathode and a separator positioned between the cathode and anode with an organic electrolyte solution absorbed therein is provided. The anode comprises three-dimensional microporous carbon structures synthesized from polymeric high internal phase emulsions or materials derived from this emulsion source, i.e., granules, powders, etc.

  12. Structural micro-porous carbon anode for rechargeable lithium-ion batteries

    DOEpatents

    Delnick, F.M.; Even, W.R. Jr.; Sylwester, A.P.; Wang, J.C.F.; Zifer, T.

    1995-06-20

    A secondary battery having a rechargeable lithium-containing anode, a cathode and a separator positioned between the cathode and anode with an organic electrolyte solution absorbed therein is provided. The anode comprises three-dimensional microporous carbon structures synthesized from polymeric high internal phase emulsions or materials derived from this emulsion source, i.e., granules, powders, etc. 6 figs.

  13. Synthesis and characterization of carbon-coated Fe{sub 3}O{sub 4} nanoflakes as anode material for lithium-ion batteries

    SciTech Connect

    Wan, Yun-hai; Shi, Xiao-qin; Xia, Hui; Xie, Jian

    2013-11-15

    Graphical abstract: - Highlights: • Carbon-coated Fe{sub 3}O{sub 4} nanoflakes have been synthesized by hydrothermal method. • The nanocomposite electrode shows a large reversible capacity up to 740 mAh g{sup −1}. • The nanocomposite electrode shows promising cycling stability and rate capability. - Abstract: The carbon-coated Fe{sub 3}O{sub 4} nanoflakes were synthesized by partial reduction of monodispersed hematite (Fe{sub 2}O{sub 3}) nanoflakes with carbon coating. The carbon-coated Fe{sub 3}O{sub 4} nanoflakes were characterized by X-ray diffraction, Raman spectroscopy, field emission scanning electron microscopy, transmission electron microscopy, and galvanostatic charge/discharge measurements. It has been demonstrated that Fe{sub 2}O{sub 3} can be completely converted to Fe{sub 3}O{sub 4} during the reduction process and carbon can be successfully coated on the surface of Fe{sub 3}O{sub 4} nanoflakes, forming a conductive matrix. As anode material for lithium-ion batteries, the carbon-coated Fe{sub 3}O{sub 4} nanoflakes exhibit a large reversible capacity up to 740 mAh g{sup −1} with significantly improved cycling stability and rate capability compared to the bare Fe{sub 2}O{sub 3} nanoflakes. The superior electrochemical performance of the carbon-coated Fe{sub 3}O{sub 4} nanoflakes can be attributed to the synthetic effects between small particle size and highly conductive carbon matrix.

  14. Multiscale anode materials in lithium ion batteries by combining micro- with nanoparticles: design of mesoporous TiO2 microfibers@nitrogen doped carbon composites

    NASA Astrophysics Data System (ADS)

    Cheng, Wei; Rechberger, Felix; Primc, Darinka; Niederberger, Markus

    2015-08-01

    TiO2 has been considered as a promising anode material for lithium ion batteries. However, its poor rate capability originating from the intrinsically low lithium ion diffusivity and its poor electronic conductivity hampers putting such an application into practice. Both issues can be addressed by nanostructure engineering and conductive surface coating. Herein, we report a template-assisted synthesis of micron sized TiO2 fibers consisting of a mesoporous network of anatase nanoparticles of about 7.5 nm and coated by N doped carbon. In a first step, an amorphous layer of TiO2 was deposited on cobalt silicate nanobelts and subsequently transformed into crystalline anatase nanoparticles by hydrothermal treatment. The N doped carbon coating was realized by in situ polymerization of dopamine on the crystalline TiO2 followed by annealing under N2. After removal of the template, we obtained the final mesoporous TiO2 fibers@N doped carbon composite. Electrochemical tests revealed that the composite electrode exhibited excellent electrochemical properties in terms of specific capacity, rate performance and long term stability.TiO2 has been considered as a promising anode material for lithium ion batteries. However, its poor rate capability originating from the intrinsically low lithium ion diffusivity and its poor electronic conductivity hampers putting such an application into practice. Both issues can be addressed by nanostructure engineering and conductive surface coating. Herein, we report a template-assisted synthesis of micron sized TiO2 fibers consisting of a mesoporous network of anatase nanoparticles of about 7.5 nm and coated by N doped carbon. In a first step, an amorphous layer of TiO2 was deposited on cobalt silicate nanobelts and subsequently transformed into crystalline anatase nanoparticles by hydrothermal treatment. The N doped carbon coating was realized by in situ polymerization of dopamine on the crystalline TiO2 followed by annealing under N2. After

  15. Porous γ-Fe2O3 spheres coated with N-doped carbon from polydopamine as Li-ion battery anode materials.

    PubMed

    Liang, Jin; Xiao, Chunhui; Chen, Xu; Gao, Ruixia; Ding, Shujiang

    2016-05-27

    Nitrogen doping has been demonstrated to play a crucial role in controlling the electronic properties of carbon-based composites. In this paper, nitrogen-doped carbon coated γ-Fe2O3 (NC@γ-Fe2O3) composite was successfully fabricated through a facile and high-yield strategy, including a hydrothermal reaction process for porous γ-Fe2O3 and a subsequent coating of nitrogen-doped carbon by using dopamine as precursor. The resulting composite combines the superior properties of porous Fe2O3 and heteroatom-doped conductive carbon layer derived from polydopamine. When used as the anode material of the lithium-ion battery, the as-prepared NC@γ-Fe2O3 composite exhibits excellent lithium storage properties in terms of high capacity, stable cycling performance (869.6 mAh g(-1) at the current density of 0.5 A g(-1) after 150 cycles) and excellent rate capability. PMID:27095053

  16. Porous γ-Fe2O3 spheres coated with N-doped carbon from polydopamine as Li-ion battery anode materials

    NASA Astrophysics Data System (ADS)

    Liang, Jin; Xiao, Chunhui; Chen, Xu; Gao, Ruixia; Ding, Shujiang

    2016-05-01

    Nitrogen doping has been demonstrated to play a crucial role in controlling the electronic properties of carbon-based composites. In this paper, nitrogen-doped carbon coated γ-Fe2O3 (NC@γ-Fe2O3) composite was successfully fabricated through a facile and high-yield strategy, including a hydrothermal reaction process for porous γ-Fe2O3 and a subsequent coating of nitrogen-doped carbon by using dopamine as precursor. The resulting composite combines the superior properties of porous Fe2O3 and heteroatom-doped conductive carbon layer derived from polydopamine. When used as the anode material of the lithium-ion battery, the as-prepared NC@γ-Fe2O3 composite exhibits excellent lithium storage properties in terms of high capacity, stable cycling performance (869.6 mAh g‑1 at the current density of 0.5 A g‑1 after 150 cycles) and excellent rate capability.

  17. Na-Ion Battery Anodes: Materials and Electrochemistry.

    PubMed

    Luo, Wei; Shen, Fei; Bommier, Clement; Zhu, Hongli; Ji, Xiulei; Hu, Liangbing

    2016-02-16

    The intermittent nature of renewable energy sources, such as solar and wind, calls for sustainable electrical energy storage (EES) technologies for stationary applications. Li will be simply too rare for Li-ion batteries (LIBs) to be used for large-scale storage purposes. In contrast, Na-ion batteries (NIBs) are highly promising to meet the demand of grid-level storage because Na is truly earth abundant and ubiquitous around the globe. Furthermore, NIBs share a similar rocking-chair operation mechanism with LIBs, which potentially provides high reversibility and long cycling life. It would be most efficient to transfer knowledge learned on LIBs during the last three decades to the development of NIBs. Following this logic, rapid progress has been made in NIB cathode materials, where layered metal oxides and polyanionic compounds exhibit encouraging results. On the anode side, pure graphite as the standard anode for LIBs can only form NaC64 in NIBs if solvent co-intercalation does not occur due to the unfavorable thermodynamics. In fact, it was the utilization of a carbon anode in LIBs that enabled the commercial successes. Anodes of metal-ion batteries determine key characteristics, such as safety and cycling life; thus, it is indispensable to identify suitable anode materials for NIBs. In this Account, we review recent development on anode materials for NIBs. Due to the limited space, we will mainly discuss carbon-based and alloy-based anodes and highlight progress made in our groups in this field. We first present what is known about the failure mechanism of graphite anode in NIBs. We then go on to discuss studies on hard carbon anodes, alloy-type anodes, and organic anodes. Especially, the multiple functions of natural cellulose that is used as a low-cost carbon precursor for mass production and as a soft substrate for tin anodes are highlighted. The strategies of minimizing the surface area of carbon anodes for improving the first-cycle Coulombic efficiency are

  18. Bio-Inspired Hierarchical Nanofibrous Fe3O4-TiO2-Carbon Composite as a High-Performance Anode Material for Lithium-Ion Batteries.

    PubMed

    Li, Shun; Wang, Mengya; Luo, Yan; Huang, Jianguo

    2016-07-13

    A bioinspired hierarchical nanofibrous Fe3O4-TiO2-carbon composite was fabricated by employing natural cellulose substance (e.g., filter paper) as both the scaffold and the carbon source and showed improved electrochemical performances when it is employed as an anode material for lithium-ion batteries. FeOOH nanoparticles were first grown uniformly onto the surface of the titania thin-layer precoated cellulose nanofibers, and thereafter, the as-prepared FeOOH-TiO2-cellulose composite was calcined and carbonized in argon atmosphere at 500 °C for 6 h to produce the Fe3O4-TiO2-carbon composite. The resultant composite possesses a hierarchical structure that was faithfully inherited from the initial cellulose substance, which was composed of titania-coated carbon fibers with corncob-like shaped Fe3O4 nanoparticles immobilized on the surfaces. The diameter of the composite nanofiber is ca. 100-200 nm, and the diameter of the Fe3O4 nanoparticle is about 30 nm, which is coated with an ultrathin carbon layer with a thickness about 3 nm. This composite displayed superior lithium-ion storage performance. It showed a first-cycle discharge capacity of 1340 mAh/g, delivering a stable reversible capacity of ca. 525 mAh/g after 100 charge-discharge cycles at a current density of 100 mA/g, and the efficiency is as high as ca. 95% of the theoretical value. This is much higher than those of the commercial Fe3O4 powder (160 mAh/g) and the Fe3O4-carbon counter material (310 mAh/g). It was demonstrated that the thin titania precoating layer (thickness ca. 3-5 nm) is necessary for the high content loading of the Fe3O4 nanoparticles onto the carbon nanofibers. Owing to the unique three-dimensional porous network structure of the carbon-fiber scaffold, together with the ultrathin outer carbon-coating layer, the composite showed significantly improved cycling stability and rate capability. PMID:27328774

  19. Microscopical characterization of carbon materials derived from coal and petroleum and their interaction phenomena in making steel electrodes, anodes and cathode blocks for the Microscopy of Carbon Materials Working Group of the ICCP

    USGS Publications Warehouse

    Predeanu, G.; Panaitescu, C.; Bălănescu, M.; Bieg, G.; Borrego, A.G.; Diez, M. A.; Hackley, Paul C.; Kwiecińska, B.; Marques, M.; Mastalerz, Maria; Misz-Kennan, M.; Pusz, S.; Suarez-Ruiz, I.; Rodrigues, S.; Singh, A. K.; Varma, A. K.; Zdravkov, A.; Zivotić, D.

    2015-01-01

    This paper describes the evaluation of petrographic textures representing the structural organization of the organic matter derived from coal and petroleum and their interaction phenomena in the making of steel electrodes, anodes and cathode blocks.This work represents the results of the Microscopy of Carbon Materials Working Group in Commission III of the International Committee for Coal and Organic Petrology between the years 2009 and 2013. The round robin exercises were run on photomicrograph samples. For textural characterization of carbon materials the existing ASTM classification system for metallurgical coke was applied.These round robin exercises involved 15 active participants from 12 laboratories who were asked to assess the coal and petroleum based carbons and to identify the morphological differences, as optical texture (isotropic/anisotropic), optical type (punctiform, mosaic, fibre, ribbon, domain), and size. Four sets of digital black and white microphotographs comprising 151 photos containing 372 fields of different types of organic matter were examined. Based on the unique ability of carbon to form a wide range of textures, the results showed an increased number of carbon occurrences which have crucial role in the chosen industrial applications.The statistical method used to evaluate the results was based on the “raw agreement indices”. It gave a new and original view on the analysts' opinion by not only counting the correct answers, but also all of the knowledge and experience of the participants. Comparative analyses of the average values of the level of overall agreement performed by each analyst in the exercises during 2009–2013 showed a great homogeneity in the results, the mean value being 90.36%, with a minimum value of 83% and a maximum value of 95%.

  20. Effects of anode material on arcjet performance

    NASA Technical Reports Server (NTRS)

    Sankovic, John M.; Curran, Frank M.; Larson, C. A.

    1992-01-01

    Anodes fabricated from four different materials were tested in a modular arcjet thruster at 1 kW power level on nitrogen/hydrogen mixtures. A two-percent thoriated tungsten anode served as the control. Graphite was chosen for its ease in fabrication, but experienced severe erosion in the constrictor and diverging side. Hafnium carbide and lanthanum hexaboride were chosen for their low work functions but failed due to thermal stress and reacted with the propellant. When compared to the thoriated tungsten nozzle, thruster performance was significantly lower for the lanthanum hexaboride insert and the graphite nozzle, but was slightly higher for the hafnium carbide nozzle. Both the lanthanum hexaboride and hafnium carbide nozzle operated at higher voltages. An attempt was made to duplicate higher performance hafnium carbide results, but repeated attempts at machining a second anode insert were unsuccessful. Graphite, hafnium carbide, and lanthanum hexaboride do not appear viable anode materials for low power arcjet thrusters.

  1. Facile scalable synthesis of Co{sub 3}O{sub 4}/carbon nanotube hybrids as superior anode materials for lithium-ion batteries

    SciTech Connect

    Fang, Zhiguo; Xu, Weiwei; Huang, Tao; Li, Maolin; Wang, Wanren; Liu, Yanping; Mao, Chaochao; Meng, Fanli; Wang, Mengjiao; Cheng, Minghai; Yu, Aishui; Guo, Xiaohui

    2013-10-15

    Graphical abstract: Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via strong ultra-sonication assisted shaking processes. The resultant samples as anode electrode display enhanced cycling performance and rate capability compared with pure Co{sub 3}O{sub 4} particle. - Highlights: • Co{sub 3}O{sub 4}/MWCNT hybrids were synthesized via ultra-sonication assisted shaking process. • The resulting Co{sub 3}O{sub 4} nanoparticles are highly dispersed onto MWCNT network backbone. • Co{sub 3}O{sub 4}/MWCNT hybrid displays highly enhanced lithium storage properties. • The present synthetic approach is facile, controllable, and scalable. - Abstract: In this report, Co{sub 3}O{sub 4}/multiple-wall carbon nanotube (MWCNT) hybrid materials were synthesized via strong ultrasonication-assisted shaking and magnetic stirring processes. The prepared samples were well characterized by utilizing powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy techniques. Results indicated that the resulting Co{sub 3}O{sub 4} nanoparticles were highly dispersed in the MWCNT network backbone and further form Co{sub 3}O{sub 4}/MWCNT hybrid materials. The obtained Co{sub 3}O{sub 4}/MWCNT hybrids can be employed as anode electrode in Lithium-ion batteries and deliver as high as discharge capacity of 1250 mA h g{sup −1} at a current density of 0.2 C, additionally, 81% of the discharge capacity for sample 2 with 20 wt.% MWCNT loading could be retained after 70 cycles, which could be associated with the specific hybrid structure of the electrode as well as the addition of MWCNT. Most importantly, the present synthetic approach is facile, controllable, and scalable, which allowing it more easily adapted to prepare other hybrid materials with specific architectures.

  2. The effect of hydrogenation on the growth of carbon nanospheres and their performance as anode materials for rechargeable lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Shijia; Fan, Yunxia; Zhu, Kai; Zhang, Dong; Zhang, Weiwei; Chen, Shuanglong; Liu, Ran; Yao, Mingguang; Liu, Bingbing

    2015-01-01

    Hydrogenated carbon nanomaterials exhibit many advantages in both mechanical and electrochemical properties, and thus have a wide range of potential applications. However, methods to control the hydrogenation and the effect of hydrogenation on the microstructure and properties of the produced nanomaterials have rarely been studied. Here we report the synthesis of hydrogenated carbon nanospheres (HCNSs) with different degrees of hydrogenation by a facile solvothermal method, in which C2H3Cl3/C2H4Cl2 was used as the carbon precursor and potassium as the reductant. The hydrogenation level of the obtained nanospheres depends on the reaction temperature and higher temperature leads to lower hydrogenation due to the fact that the breaking of C-H bonds requires more external energy. The reaction temperature also affects the diameter of the HCNSs and larger spheres are produced at higher temperatures. More importantly, the size and the degree of hydrogenation are both critical factors for determining the electrochemical properties of the HCNSs. The nanospheres synthesized at 100 °C have a smaller size and a higher hydrogenation degree and show a capacity of 821 mA h g-1 after 50 cycles, which is significantly higher than that of the HCNSs produced at 150 °C (450 mA h g-1). Our study opens a possible way for obtaining high-performance anode materials for rechargeable lithium-ion batteries.

  3. Compositing amorphous TiO2 with N-doped carbon as high-rate anode materials for lithium-ion batteries.

    PubMed

    Xiao, Ying; Hu, Changwen; Cao, Minhua

    2014-01-01

    Compositing amorphous TiO2 with nitrogen-doped carbon through Ti-N bonding to form an amorphous TiO2/N-doped carbon hybrid (denoted a-TiO2/C-N) has been achieved by a two-step hydrothermal-calcining method with hydrazine hydrate as an inhibitor and nitrogen source. The resultant a-TiO2/C-N hybrid has a surface area as high as 108 m(2) g(-1) and, when used as an anode material, exhibits a capacity as high as 290.0 mA h g(-1) at a current rate of 1 C and a reversible capacity over 156 mA h g(-1) at a current rate of 10 C after 100 cycles; these results are better than those found in most reports on crystalline TiO2 . This superior electrochemical performance could be ascribed to a combined effect of several factors, including the amorphous nature, porous structure, high surface area, and N-doped carbon. PMID:24347075

  4. Multiscale anode materials in lithium ion batteries by combining micro- with nanoparticles: design of mesoporous TiO2 microfibers@nitrogen doped carbon composites.

    PubMed

    Cheng, Wei; Rechberger, Felix; Primc, Darinka; Niederberger, Markus

    2015-09-01

    TiO2 has been considered as a promising anode material for lithium ion batteries. However, its poor rate capability originating from the intrinsically low lithium ion diffusivity and its poor electronic conductivity hampers putting such an application into practice. Both issues can be addressed by nanostructure engineering and conductive surface coating. Herein, we report a template-assisted synthesis of micron sized TiO2 fibers consisting of a mesoporous network of anatase nanoparticles of about 7.5 nm and coated by N doped carbon. In a first step, an amorphous layer of TiO2 was deposited on cobalt silicate nanobelts and subsequently transformed into crystalline anatase nanoparticles by hydrothermal treatment. The N doped carbon coating was realized by in situ polymerization of dopamine on the crystalline TiO2 followed by annealing under N2. After removal of the template, we obtained the final mesoporous TiO2 fibers@N doped carbon composite. Electrochemical tests revealed that the composite electrode exhibited excellent electrochemical properties in terms of specific capacity, rate performance and long term stability. PMID:26220269

  5. Preparation of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres as an efficient anode material for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Geng, Hongbo; Zhou, Qun; Pan, Yue; Gu, Hongwei; Zheng, Junwei

    2014-03-01

    Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g-1 at a rate of 0.1 C after 70 cycles, 800 mA h g-1 at a rate of 0.5 C after 120 cycles and 620 mA h g-1 at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications.Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g-1 at a rate of 0.1 C after 70 cycles, 800 mA h g-1 at a rate of 0.5 C after 120 cycles and 620 mA h g-1 at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications. Electronic supplementary information (ESI) available: Additional TGA, SEM, TEM, HRTEM, EDX spectra and elemental mapping, XRD and

  6. Octahedral Tin Dioxide Nanocrystals Anchored on Vertically Aligned Carbon Aerogels as High Capacity Anode Materials for Lithium-Ion Batteries

    PubMed Central

    Liu, Mingkai; Liu, Yuqing; Zhang, Yuting; Li, Yiliao; Zhang, Peng; Yan, Yan; Liu, Tianxi

    2016-01-01

    A novel binder-free graphene - carbon nanotubes - SnO2 (GCNT-SnO2) aerogel with vertically aligned pores was prepared via a simple and efficient directional freezing method. SnO2 octahedrons exposed of {221} high energy facets were uniformly distributed and tightly anchored on multidimensional graphene/carbon nanotube (GCNT) composites. Vertically aligned pores can effectively prevent the emersion of “closed” pores which cannot load the active SnO2 nanoparticles, further ensure quick immersion of electrolyte throughout the aerogel, and can largely shorten the transport distance between lithium ions and active sites of SnO2. Especially, excellent electrical conductivity of GCNT-SnO2 aerogel was achieved as a result of good interconnected networks of graphene and CNTs. Furthermore, meso- and macroporous structures with large surface area created by the vertically aligned pores can provide great benefit to the favorable transport kinetics for both lithium ion and electrons and afford sufficient space for volume expansion of SnO2. Due to the well-designed architecture of GCNT-SnO2 aerogel, a high specific capacity of 1190 mAh/g with good long-term cycling stability up to 1000 times was achieved. This work provides a promising strategy for preparing free-standing and binder-free active electrode materials with high performance for lithium ion batteries and other energy storage devices. PMID:27510357

  7. Octahedral Tin Dioxide Nanocrystals Anchored on Vertically Aligned Carbon Aerogels as High Capacity Anode Materials for Lithium-Ion Batteries.

    PubMed

    Liu, Mingkai; Liu, Yuqing; Zhang, Yuting; Li, Yiliao; Zhang, Peng; Yan, Yan; Liu, Tianxi

    2016-01-01

    A novel binder-free graphene - carbon nanotubes - SnO2 (GCNT-SnO2) aerogel with vertically aligned pores was prepared via a simple and efficient directional freezing method. SnO2 octahedrons exposed of {221} high energy facets were uniformly distributed and tightly anchored on multidimensional graphene/carbon nanotube (GCNT) composites. Vertically aligned pores can effectively prevent the emersion of "closed" pores which cannot load the active SnO2 nanoparticles, further ensure quick immersion of electrolyte throughout the aerogel, and can largely shorten the transport distance between lithium ions and active sites of SnO2. Especially, excellent electrical conductivity of GCNT-SnO2 aerogel was achieved as a result of good interconnected networks of graphene and CNTs. Furthermore, meso- and macroporous structures with large surface area created by the vertically aligned pores can provide great benefit to the favorable transport kinetics for both lithium ion and electrons and afford sufficient space for volume expansion of SnO2. Due to the well-designed architecture of GCNT-SnO2 aerogel, a high specific capacity of 1190 mAh/g with good long-term cycling stability up to 1000 times was achieved. This work provides a promising strategy for preparing free-standing and binder-free active electrode materials with high performance for lithium ion batteries and other energy storage devices. PMID:27510357

  8. Recycled diesel carbon nanoparticles for nanostructured battery anodes

    NASA Astrophysics Data System (ADS)

    Chen, Yuming; Liu, Chang; Sun, Xiaoxuan; Ye, Han; Cheung, Chunshun; Zhou, Limin

    2015-02-01

    Considerable attention has been devoted to using rational nanostructure design to address critical carbonaceous anode material issues for next-generation lithium-ion batteries (LIBs). However, the fabrication of nanostructured carbonaceous anode materials often involves complex processes and expensive starting materials. Diesel engine is an important source of nanostructured carbon particles with diameters ranging 20 nm-60 nm suspended in air, resulting in a serious scourge of global climate and a series of diseases such as lung cancer, asthma, and cardiovascular disease. Here, we show that diesel carbon nanoparticles collected from diesel engines can be chemically activated to create a porous structure. The resulting nanostructured carbon electrodes have a high specific capacity of 936 mAh g-1 after 40 cycles at 0.05 A/g, and excellent cycle stability while retaining a capacity of ∼210 mAh g-1 after 1200 cycles at 5 A/g. As recycled diesel carbon nanoparticles are readily available due to the several billion tons of diesel fuel consumed every year by diesel engines, their use represents an exciting source for nanostructured carbonaceous anode materials for high-performance LIBs and improves our environment and health.

  9. Preparation of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres as an efficient anode material for Li-ion batteries.

    PubMed

    Geng, Hongbo; Zhou, Qun; Pan, Yue; Gu, Hongwei; Zheng, Junwei

    2014-04-01

    Herein we report the design and synthesis of fluorine-doped, carbon-encapsulated hollow Fe3O4 spheres (h-Fe3O4@C/F) through mild heating of polyvinylidene fluoride (PVDF)-coated hollow Fe3O4 spheres. The spheres exhibit enhanced cyclic and rate performances. The as-prepared h-Fe3O4@C/F shows significantly improved electrochemical performance, with high reversible capacities of over 930 mA h g(-1) at a rate of 0.1 C after 70 cycles, 800 mA h g(-1) at a rate of 0.5 C after 120 cycles and 620 mA h g(-1) at a rate of 1 C after 200 cycles. This improved lithium storage performance is mainly ascribed to the encapsulation of the spheres with fluorine-doped carbon, which not only improves the reaction kinetics and stability of the solid electrolyte interface film but also prevents aggregation and drastic volume change of the Fe3O4 particles. These spheres thus represent a promising anode material in lithium-ion battery applications. PMID:24598908

  10. Graphitic Carbon-Coated FeSe2 Hollow Nanosphere-Decorated Reduced Graphene Oxide Hybrid Nanofibers as an Efficient Anode Material for Sodium Ion Batteries

    NASA Astrophysics Data System (ADS)

    Cho, Jung Sang; Lee, Jung-Kul; Kang, Yun Chan

    2016-04-01

    A novel one-dimensional nanohybrid comprised of conductive graphitic carbon (GC)-coated hollow FeSe2 nanospheres decorating reduced graphene oxide (rGO) nanofiber (hollow nanosphere FeSe2@GC–rGO) was designed as an efficient anode material for sodium ion batteries and synthesized by introducing the nanoscale Kirkendall effect into the electrospinning method. The electrospun nanofibers transformed into hollow nanosphere FeSe2@GC–rGO hybrid nanofibers through a Fe@GC–rGO intermediate. The discharge capacities of the bare FeSe2 nanofibers, nanorod FeSe2–rGO–amorphous carbon (AC) hybrid nanofibers, and hollow nanosphere FeSe2@GC–rGO hyrbid nanofibers at a current density of 1 A g‑1 for the 150th cycle were 63, 302, and 412 mA h g‑1, respectively, and their corresponding capacity retentions measured from the 2nd cycle were 11, 73, and 82%, respectively. The hollow nanosphere FeSe2@GC–rGO hybrid nanofibers delivered a high discharge capacity of 352 mA h g‑1 even at an extremely high current density of 10 A g‑1. The enhanced electrochemical properties of the hollow nanosphere FeSe2@GC–rGO composite nanofibers arose from the synergetic effects of the FeSe2 hollow morphology and highly conductive rGO matrix.

  11. Graphitic Carbon-Coated FeSe2 Hollow Nanosphere-Decorated Reduced Graphene Oxide Hybrid Nanofibers as an Efficient Anode Material for Sodium Ion Batteries

    PubMed Central

    Cho, Jung Sang; Lee, Jung-Kul; Kang, Yun Chan

    2016-01-01

    A novel one-dimensional nanohybrid comprised of conductive graphitic carbon (GC)-coated hollow FeSe2 nanospheres decorating reduced graphene oxide (rGO) nanofiber (hollow nanosphere FeSe2@GC–rGO) was designed as an efficient anode material for sodium ion batteries and synthesized by introducing the nanoscale Kirkendall effect into the electrospinning method. The electrospun nanofibers transformed into hollow nanosphere FeSe2@GC–rGO hybrid nanofibers through a Fe@GC–rGO intermediate. The discharge capacities of the bare FeSe2 nanofibers, nanorod FeSe2–rGO–amorphous carbon (AC) hybrid nanofibers, and hollow nanosphere FeSe2@GC–rGO hyrbid nanofibers at a current density of 1 A g−1 for the 150th cycle were 63, 302, and 412 mA h g−1, respectively, and their corresponding capacity retentions measured from the 2nd cycle were 11, 73, and 82%, respectively. The hollow nanosphere FeSe2@GC–rGO hybrid nanofibers delivered a high discharge capacity of 352 mA h g−1 even at an extremely high current density of 10 A g−1. The enhanced electrochemical properties of the hollow nanosphere FeSe2@GC–rGO composite nanofibers arose from the synergetic effects of the FeSe2 hollow morphology and highly conductive rGO matrix. PMID:27033096

  12. Carbon Nanotube Anodes Being Evaluated for Lithium Ion Batteries

    NASA Technical Reports Server (NTRS)

    Raffaelle, Ryne P.; Gennett, Tom; VanderWal, Randy L.; Hepp, Aloysius F.

    2001-01-01

    The NASA Glenn Research Center is evaluating the use of carbon nanotubes as anode materials for thin-film lithium-ion (Li) batteries. The motivation for this work lies in the fact that, in contrast to carbon black, directed structured nanotubes and nanofibers offer a superior intercalation media for Li-ion batteries. Carbon lamellas in carbon blacks are circumferentially oriented and block much of the particle interior, rendering much of the matrix useless as intercalation material. Nanofibers, on the other hand, can be grown so as to provide 100-percent accessibility of the entire carbon structure to intercalation. These tubes can be visualized as "rolled-up" sheets of carbon hexagons (see the following figure). One tube is approximately 1/10,000th the diameter of a human hair. In addition, the high accessibility of the structure confers a high mobility to ion-exchange processes, a fundamental for the batteries to respond dynamically because of intercalation.

  13. Optimizing synthesis of silicon/disordered carbon composites for use as anode materials in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Guo, Z. P.; Jia, D. Z.; Yuan, L.; Liu, H. K.

    Pyrolysis conditions for the production of silicon/disordered carbon (Si-DC) nanocomposites using PVA as the carbon source were optimized in this work. It was found that the optimum sintering temperature for the Si-DC nanocomposites is 800 °C. In order to achieve good cell performance, a high argon gas flow rate and a slow heating rate are preferred in sample preparation. The morphology of the carbon source (PVA) affects the electrochemical performance of the Si-DC nanocomposites as well. The key point to obtain Si-DC nanocomposites with good electrochemical performance is to reduce the chances of pyrolysis gases (especially CO 2) to react with carbon, thereby preventing carbon burnoff during the sintering process.

  14. Anode materials for lithium-ion batteries

    DOEpatents

    Sunkara, Mahendra Kumar; Meduri, Praveen; Sumanasekera, Gamini

    2014-12-30

    An anode material for lithium-ion batteries is provided that comprises an elongated core structure capable of forming an alloy with lithium; and a plurality of nanostructures placed on a surface of the core structure, with each nanostructure being capable of forming an alloy with lithium and spaced at a predetermined distance from adjacent nanostructures.

  15. A novel radial anode layer ion source for inner wall pipe coating and materials modification—Hydrogenated diamond-like carbon coatings from butane gas

    NASA Astrophysics Data System (ADS)

    Murmu, Peter P.; Markwitz, Andreas; Suschke, Konrad; Futter, John

    2014-08-01

    We report a new ion source development for inner wall pipe coating and materials modification. The ion source deposits coatings simultaneously in a 360° radial geometry and can be used to coat inner walls of pipelines by simply moving the ion source in the pipe. Rotating parts are not required, making the source ideal for rough environments and minimizing maintenance and replacements of parts. First results are reported for diamond-like carbon (DLC) coatings on Si and stainless steel substrates deposited using a novel 360° ion source design. The ion source operates with permanent magnets and uses a single power supply for the anode voltage and ion acceleration up to 10 kV. Butane (C4H10) gas is used to coat the inner wall of pipes with smooth and homogeneous DLC coatings with thicknesses up to 5 μm in a short time using a deposition rate of 70 ± 10 nm min-1. Rutherford backscattering spectrometry results showed that DLC coatings contain hydrogen up to 30 ± 3% indicating deposition of hydrogenated DLC (a-C:H) coatings. Coatings with good adhesion are achieved when using a multiple energy implantation regime. Raman spectroscopy results suggest slightly larger disordered DLC layers when using low ion energy, indicating higher sp3 bonds in DLC coatings. The results show that commercially interesting coatings can be achieved in short time.

  16. A novel radial anode layer ion source for inner wall pipe coating and materials modification--hydrogenated diamond-like carbon coatings from butane gas.

    PubMed

    Murmu, Peter P; Markwitz, Andreas; Suschke, Konrad; Futter, John

    2014-08-01

    We report a new ion source development for inner wall pipe coating and materials modification. The ion source deposits coatings simultaneously in a 360° radial geometry and can be used to coat inner walls of pipelines by simply moving the ion source in the pipe. Rotating parts are not required, making the source ideal for rough environments and minimizing maintenance and replacements of parts. First results are reported for diamond-like carbon (DLC) coatings on Si and stainless steel substrates deposited using a novel 360° ion source design. The ion source operates with permanent magnets and uses a single power supply for the anode voltage and ion acceleration up to 10 kV. Butane (C4H10) gas is used to coat the inner wall of pipes with smooth and homogeneous DLC coatings with thicknesses up to 5 μm in a short time using a deposition rate of 70 ± 10 nm min(-1). Rutherford backscattering spectrometry results showed that DLC coatings contain hydrogen up to 30 ± 3% indicating deposition of hydrogenated DLC (a-C:H) coatings. Coatings with good adhesion are achieved when using a multiple energy implantation regime. Raman spectroscopy results suggest slightly larger disordered DLC layers when using low ion energy, indicating higher sp(3) bonds in DLC coatings. The results show that commercially interesting coatings can be achieved in short time. PMID:25173323

  17. One-Pot Fabrication of Hierarchical Nanosheet-Based TiO2 -Carbon Hollow Microspheres for Anode Materials of High-Rate Lithium-Ion Batteries.

    PubMed

    Jin, Zhaokui; Yang, Mu; Wang, Jingjing; Gao, Hongyi; Lu, Yunfeng; Wang, Ge

    2016-04-18

    Hierarchical and hollow nanostructures have recently attracted considerable attention because of their fantastic architectures and tunable property for facile lithium ion insertion and good cycling stability. In this study, a one-pot and unusual carving protocol is demonstrated for engineering hollow structures with a porous shell. Hierarchical TiO2 hollow spheres with nanosheet-assembled shells (TiO2 NHS) were synthesized by the sequestration between the titanium source and 2,2'-bipyridine-5,5'-dicarboxylic acid, and kinetically controlled etching in trifluoroacetic acid medium. In addition, annealing such porous nanostructures presents the advantage of imparting carbon-doped functional performance to its counterpart under different atmospheres. Such highly porous structures endow very large specifics surface area of 404 m(2)  g(-1) and 336 m(2)  g(-1) for the as-prepared and calcination under nitrogen gas. C/TiO2 NHS has high capacity of 204 mA h g(-1) at 1 C and a reversible capacity of 105 mA h g(-1) at a high rate of 20 C, and exhibits good cycling stability and superior rate capability as an anode material for lithium-ion batteries. PMID:26970239

  18. Ultrasonication-assisted ultrafast preparation of multiwalled carbon nanotubes/Au/Co3O4 tubular hybrids as superior anode materials for oxygen evolution reaction

    NASA Astrophysics Data System (ADS)

    Fang, Yiyun; Li, Xinzhe; Hu, Yiping; Li, Feng; Lin, Xiaoqing; Tian, Min; An, Xingcai; Fu, Yan; Jin, Jun; Ma, Jiantai

    2015-12-01

    Efficient and simple operation electrocatalysts for the oxygen evolution reaction (OER) are essential components of renewable energy technologies. Here, a novel, simple, and efficient routine is presented for the first time by constructing a high-efficiency anode catalyst for OER. With the aid of high intensity ultrasound, a uniformly loading, conductive multiwalled carbon nanotubes/metal/transition metal-oxide (CNTs-Au@Co3O4) tubular hybrids is synthesized. In alkaline media, the materials catalyze OER with an onset potential of 1.56 V vs. reversible hydrogen electrode (RHE) and overpotential only of 350 mV to achieve a stable current density of 10 mA cm-2 for at least 25 h. The unusual catalytic activity and stability is due to the following elements. Firstly, the tubular architecture not only provides sufficient active centers for OER, but also improves rapid mass/charge transport. Secondly, Co3O4 layer protects Au nanoparticles (NPs) against detachment. In addition, we also prove that the highest electronegativity metal Au accelerate the formation of catalytic active sites of CoIV species for OER. It is believed that this simple preparation method paves a way to fabricate a range of CNTs/metal/metal-oxide based composites as superior OER catalysts.

  19. Controlled Synthesis of Carbon Nanofibers Anchored with Zn(x)Co(3-x)O4 Nanocubes as Binder-Free Anode Materials for Lithium-Ion Batteries.

    PubMed

    Chen, Renzhong; Hu, Yi; Shen, Zhen; Chen, Yanli; He, Xia; Zhang, Xiangwu; Zhang, Yan

    2016-02-01

    The direct growth of complex ternary metal oxides on three-dimensional conductive substrates is highly desirable for improving the electrochemical performance of lithium-ion batteries (LIBs). We herein report a facile and scalable strategy for the preparation of carbon nanofibers (CNFs) anchored with ZnxCo3-xO4 (ZCO) nanocubes, involving a hydrothermal process and thermal treatment. Moreover, the size of the ZCO nanocubes was adjusted by the quantity of urea used in the hydrothermal process. Serving as a binder-free anode material for LIBs, the ZnCo2O4/CNFs composite prepared using 1.0 mmol of urea (ZCO/CNFs-10) exhibited excellent electrochemical performance with high reversible capacity, excellent cycling stability, and good rate capability. More specifically, a high reversible capacity of ∼600 mAh g(-1) was obtained at a current density of 0.5 C following 300 charge-discharge cycles. The excellent electrochemical performance could be associated with the controllable size of the ZCO nanocubes and synergistic effects between ZCO and the CNFs. PMID:26761129

  20. Synthesis of SiO2/3D porous carbon composite as anode material with enhanced lithium storage performance

    NASA Astrophysics Data System (ADS)

    Yuan, Zhinan; Zhao, Naiqin; Shi, Chunsheng; Liu, Enzuo; He, Chunnian; He, Fang

    2016-05-01

    A SiO2/porous carbon nanocomposite was synthesized by a facile combined heat and acid treatments method. The nanocomposite featured a 3D porous carbon structure with amorphous SiO2 nanoparticles embedded in the wall of the pores. The microstructure improved the electrical conductivity, shortened the diffusion distance of lithium ions, and alleviated the volume expansion of SiO2 during Li intercalation. Accordingly, the SiO2/porous carbon nanocomposite displayed excellent cyclic performance with a high reversible capacity of 434 mAh g-1 after 50 cycles at 0.1 A g-1 and rate capability delivering a capacity of 187.4 mAh g-1 even at 5 A g-1.

  1. Porous carbon-coated silica macroparticles as anode materials for lithium ion batteries: Effect of boric acid

    NASA Astrophysics Data System (ADS)

    Kim, Young-Kuk; Moon, Jong-Woo; Lee, Jung-Goo; Baek, Youn-Kyung; Hong, Seong-Hyun

    2014-12-01

    We report carbon-coated porous silica macroparticles (SiO2@C) prepared using polymeric templates and subsequent carbonization with sucrose for improved electrochemical energy storage in lithium-ion batteries (LIBs). In addition, boron is introduced to improve the stability of electrochemical cells by pyrolyzing mixtures of sucrose and boric acid (SiO2@C + B) under inert atmosphere. The initially large surface area of porous SiO2 (SBET ∼ 658 m2 g-1) is reduced to 102 m2 g-1 after carbonization and introduction of boric acid. Surface of both SiO2@C and SiO2@C + B are covered with amorphous carbon. In particular, SiO2@C + B particles containing borosilicate (Si-O-B) phase and B-O bondings and Si-C-O bondings are also detected from the X-ray photoelectron spectra. The SiO2@C + B macroparticles shows high reversible charge capacity up to 503 mAh g-1 after 103 cycles of Li intercalation/de-intercalation although initial capacity was 200 mAh g-1. The improved charge capacity of SiO2@C + B is attributed to formation of advantageous microstructures induced from boric acid.

  2. Porous carbon-coated silica macroparticles as anode materials for lithium ion batteries: Effect of boric acid

    NASA Astrophysics Data System (ADS)

    Kim, Young-Kuk; Moon, Jong-Woo; Lee, Jung-Goo; Baek, Youn-Kyung; Hong, Seong-Hyun

    2014-12-01

    We report carbon-coated porous silica macroparticles (SiO2@C) prepared using polymeric templates and subsequent carbonization with sucrose for improved electrochemical energy storage in lithium-ion batteries (LIBs). In addition, boron is introduced to improve the stability of electrochemical cells by pyrolyzing mixtures of sucrose and boric acid (SiO2@C + B) under inert atmosphere. The initially large surface area of porous SiO2 (SBET ˜ 658 m2 g-1) is reduced to 102 m2 g-1 after carbonization and introduction of boric acid. Surface of both SiO2@C and SiO2@C + B are covered with amorphous carbon. In particular, SiO2@C + B particles containing borosilicate (Si-O-B) phase and B-O bondings and Si-C-O bondings are also detected from the X-ray photoelectron spectra. The SiO2@C + B macroparticles shows high reversible charge capacity up to 503 mAh g-1 after 103 cycles of Li intercalation/de-intercalation although initial capacity was 200 mAh g-1. The improved charge capacity of SiO2@C + B is attributed to formation of advantageous microstructures induced from boric acid.

  3. Amorphous red phosphorous embedded in carbon nanotubes scaffold as promising anode materials for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Yuan, Demao; Cheng, Jianli; Qu, Guoxing; Li, Xiaodong; Ni, Wei; Wang, Bin; Liu, Heng

    2016-01-01

    Amorphous red phosphorus/carbon nanotubes (ARPC) composites are prepared by planetary ball-milling technique with the pre-milling red phosphorus processes, consisting of uniformly distributing amorphous red phosphorus embedding in a three-dimensional conductive scaffold of interconnected carbon nanotubes (CNTs). Combining the three-dimensional conductive network with the amorphous red phosphorus can not only alleviate the volumetric change in the charging/discharging processes, but also provide conductive network for electron transport and dramatically improve the specific capacity, cycling stability and rate capability of the composite electrode. The ARPC composites deliver a high initial charge capacity of 2133.4 mAh g-1 at a current density of 0.05 C and maintain a reversible capacity of 998.5 mAh g-1 with a high Coulombic efficiency of approximately 99% after 50 cycles. Meanwhile, the composite can maintain high specific capacities of 1993.8 mAh g-1, 1896.9 mAh g-1, 1546.8 mAh g-1 and 816.6 mAh g-1 at 0.01 C, 0.05 C, 0.1 C and 0.5 C, respectively. Compared with that of the ball-milled amorphous red phosphorus with or without CNTs, the pre-milled ARPC composites show much better electrochemical performances.

  4. Single-Wall Carbon Nanotube Anodes for Lithium Cells

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Raffaelle, Ryne; Gennett, Tom; Kumta, Prashant; Maranchi, Jeff; Heben, Mike

    2006-01-01

    In recent experiments, highly purified batches of single-wall carbon nanotubes (SWCNTs) have shown promise as superior alternatives to the graphitic carbon-black anode materials heretofore used in rechargeable thin-film lithium power cells. The basic idea underlying the experiments is that relative to a given mass of graphitic carbon-black anode material, an equal mass of SWCNTs can be expected to have greater lithium-storage and charge/discharge capacities. The reason for this expectation is that whereas the microstructure and nanostructure of a graphitic carbon black is such as to make most of the interior of the material inaccessible for intercalation of lithium, a batch of SWCNTs can be made to have a much more open microstructure and nanostructure, such that most of the interior of the material is accessible for intercalation of lithium. Moreover, the greater accessibility of SWCNT structures can be expected to translate to greater mobilities for ion-exchange processes and, hence, an ability to sustain greater charge and discharge current densities.

  5. Anodic electrosynthesis of some peroxy compounds on glassy carbon electrodes

    SciTech Connect

    Khomutov, N.E.; Zakhodyakina, N.A.; Svirida, L.V.; Nesvat, N.V.

    1987-11-10

    The authors present the results of a study of the anodic electrosynthesis of hydrogen peroxide and its derivatives on glassy carbon in solutions of sodium carbonate and sodium carbonate with sodium borate. We studied the kinetics of anodic processes on glassy carbon with the aid of polarization measurements and a method for determining the concentrations of active oxygen in the anolyte and the current efficiency. The current efficiencies with respect to active oxygen obtained on glassy carbon in the mixed solution of sodium borate and sodium carbonate are close to the current efficiencies which are observed on platinum anodes in the industrial electrosynthesis of perborates.

  6. Catalyzed electrochemical gasification of carbonaceous materials at anode and electrowinning of metals at cathode

    SciTech Connect

    Vaughan, R.J.

    1983-09-20

    The electrochemical gasification reaction of carbonaceous materials by anodic oxidation in an aqueous acidic electrolyte to produce oxides of carbon at the anode and metallic elements at the cathode of an electrolysis cell is catalyzed by the use of an iron catalyst.

  7. Porous graphene for high capacity lithium ion battery anode material

    NASA Astrophysics Data System (ADS)

    Wang, Yusheng; Zhang, Qiaoli; Jia, Min; Yang, Dapeng; Wang, Jianjun; Li, Meng; Zhang, Jing; Sun, Qiang; Jia, Yu

    2016-02-01

    Based on density functional theory calculations, we studied the Li dispersed on porous graphene (PG) for its application as Li ion battery anode material. The hybridization of Li atoms and the carbon atoms enhanced the interaction between Li atoms and the PG. With holes of specific size, the PG can provide excellent mobility with moderate barriers of 0.37-0.39 eV. The highest Li storage composite can be LiC0.75H0.38 which corresponds to a specific capacity of 2857.7 mA h/g. Both specific capacity and binding energy are significantly larger than the corresponding value of graphite, this makes PG a promising candidate for the anode material in battery applications. The interactions between the Li atoms and PG can be easily tuned by an applied strain. Under biaxial strain of 16%, the binding energy of Li to PG is increased by 17% compared to its unstrained state.

  8. Aerogel and xerogel composites for use as carbon anodes

    DOEpatents

    Cooper, John F.; Tillotson, Thomas M.; Hrubesh, Lawrence W.

    2010-10-12

    A method for forming a reinforced rigid anode monolith and fuel and product of such method. The method includes providing a solution of organic aerogel or xerogel precursors including at least one of a phenolic resin, phenol (hydroxybenzene), resorcinol(1,3-dihydroxybenzene), or catechol(1,2-dihydroxybenzene); at least one aldehyde compound selected from the group consisting of formaldehyde, acetaldehyde, and furfuraldehyde; and an alkali carbonate or phosphoric acid catalyst; adding internal reinforcement materials comprising carbon to said precursor solution to form a precursor mixture; gelling said precursor mixture to form a composite gel; drying said composite gel; and pyrolyzing said composite gel to form a wettable aerogel/carbon composite or a wettable xerogel/carbon composite, wherein said composites comprise chars and said internal reinforcement materials, and wherein said composite is suitable for use as an anode with the chars being fuel capable of being combusted in a molten salt electrochemical fuel cell in the range from 500 C to 800 C to produce electrical energy. Additional methods and systems/compositions are also provided.

  9. Scalable synthesis of core-shell structured SiOx/nitrogen-doped carbon composite as a high-performance anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shi, Lu; Wang, Weikun; Wang, Anbang; Yuan, Keguo; Jin, Zhaoqing; Yang, Yusheng

    2016-06-01

    In this work, a novel core-shell structured SiOx/nitrogen-doped carbon composite has been prepared by simply dispersing the SiOx particles, which are synthesized by a thermal evaporation method from an equimolar mixture of Si and SiO2, into the dopamine solution, followed by a carbonization process. The SiOx core is well covered by the conformal and homogeneous nitrogen-doped carbon layer from the pyrolysis of polydopamine. By contrast with the bare SiOx, the electrochemical performance of the as-prepared core-shell structured SiOx/nitrogen-doped carbon composite has been improved significantly. It delivers a reversible capacity of 1514 mA h g-1 after 100 cycles at a current density of 100 mA g-1 and 933 mA h g-1 at 2 A g-1, much higher than those of commercial graphite anodes. The nitrogen-doped carbon layer ensures the excellent electrochemical performance of the SiOx/C composite. In addition, since dopamine can self-polymerize and coat virtually any surface, this versatile, facile and highly efficient coating process may be widely applicable to obtain various composites with uniform nitrogen-doped carbon coating layer.

  10. Sulfur tolerant molten carbonate fuel cell anode and process

    DOEpatents

    Remick, Robert J.

    1990-01-01

    Molten carbonate fuel cell anodes incorporating a sulfur tolerant carbon monoxide to hydrogen water-gas-shift catalyst provide in situ conversion of carbon monoxide to hydrogen for improved fuel cell operation using fuel gas mixtures of over about 10 volume percent carbon monoxide and up to about 10 ppm hydrogen sulfide.

  11. Structural Analysis of Novel Lignin-derived Carbon Composite Anodes

    SciTech Connect

    McNutt, Nicholas W; Rios, Orlando; Feygenson, Mikhail; Proffen, Thomas E; Keffer, David J

    2014-01-01

    The development of novel lignin-based carbon composite anodes consisting of nanocrystalline and amorphous domains motivates the understanding of a relationship of the structural properties characterizing these materials, such as crystallite size, intracrystallite dspacing, crystalline volume fraction and composite density, with their pair distribution functions (PDF), obtained from both molecular dynamics simulation and neutron scattering. A model for these composite materials is developed as a function of experimentally measurable parameters and realized in fifteen composite systems, three of which directly match all parameters of their experimental counterparts. The accurate reproduction of the experimental PDFs using the model systems validates the model. The decomposition of the simulated PDFs provides an understanding of each feature in the PDF and allows for the development of a mapping between the defining characteristics of the PDF and the material properties of interest.

  12. Pack aluminization of nickel anode for molten carbonate fuel cells

    NASA Astrophysics Data System (ADS)

    Chun, H. S.; Park, G. P.; Lim, J. H.; Kim, K.; Lee, J. K.; Moon, K. H.; Youn, J. H.

    1994-04-01

    The aluminum pack cementation (pack aluminization) process on a porous nickel anode for molten carbonate fuel cells has been studied to improve anode creep resistance. The porous nickel substrates used in this study were fabricated by doctor blade equipment followed by sintering (850 C). Packs surrounding the Ni anode were made by mixing Al2O3 powder, Al powder, and NaCl as activator. The pack aluminization was performed at 700 to 850 C for 0.5-5.0 h. After pack aluminization, the principal Ni-Al intermetallic compounds detected were Ni3Al at 700 C, NiAl at 750 C and Ni3Al2 at 800 C. The aluminum content in the aluminized Ni anode was proportional to the square root of pack aluminizing time. With increasing the Al content in the anode, the creep of the anode decreased. It was nearly constant (2.0%) when the Al content was above 5.0%. Although the exchange current density (24 mA/sq cm) for the aluminized (2.5 wt.%) Ni anode was somewhat lower than that of the pure Ni anode (40 mA/sq cm), the performance of a single cell using an aluminized Ni anode was similar to that of the one with pure Ni anode.

  13. Upcycling of Packing-Peanuts into Carbon Microsheet Anodes for Lithium-Ion Batteries.

    PubMed

    Etacheri, Vinodkumar; Hong, Chulgi Nathan; Pol, Vilas G

    2015-09-15

    Porous carbon microsheet anodes with Li-ion storage capacity exceeding the theoretical limit are for the first time derived from waste packing-peanuts. Crystallinity, surface area, and porosity of these 1 μm thick carbon sheets were tuned by varying the processing temperature. Anodes composed of the carbon sheets outperformed the electrochemical properties of commercial graphitic anode in Li-ion batteries. At a current density of 0.1 C, carbon microsheet anodes exhibited a specific capacity of 420 mAh/g, which is slightly higher than the theoretical capacity of graphite (372 mAh/g) in Li-ion half-cell configurations. At a higher rate of 1 C, carbon sheets retained 4-fold higher specific capacity (220 mAh/g) compared to those of commercial graphitic anode. After 100 charge-discharge cycles at current densities of 0.1 and 0.2 C, optimized carbon sheet anodes retained stable specific capacities of 460 and 370 mAh/g, respectively. Spectroscopic and microscopic investigations proved the structural integrity of these high-performance carbon anodes during numerous charge-discharge cycles. Considerably higher electrochemical performance of the porous carbon microsheets are endorsed to their disorderness that facilitate to store more Li-ions than the theoretical limit, and porous 2-D microstructure enabling fast solid-state Li-ion diffusion and superior interfacial kinetics. The work demonstrated here illustrates an inexpensive and environmentally benign method for the upcycling of packaging materials into functional carbon materials for electrochemical energy storage. PMID:26098219

  14. The Anode Challenge for Lithium-Ion Batteries: A Mechanochemically Synthesized Sn-Fe-C Composite Anode Surpasses Graphitic Carbon

    DOE PAGESBeta

    Dong, Zhixin; Zhang, Ruibo; Ji, Dongsheng; Chernova, Natasha A.; Karki, Khim; Sallis, Shawn; Piper, Louis; Whittingham, M. Stanley

    2016-02-04

    Carbon-based anodes are the key limiting factor in increasing the volumetric capacity of lithium-ion batteries. Tin-based composites are one alternative approach. Nanosized Sn–Fe–C anode materials are mechanochemically synthesized by reducing SnO with Ti in the presence of carbon. The optimum synthesis conditions are found to be 1:0.25:10 for initial ratio of SnO, Ti, and graphite with a total grinding time of 8 h. This optimized composite shows excellent extended cycling at the C/10 rate, delivering a first charge capacity as high as 740 mAh g–1 and 60% of which still remained after 170 cycles. The calculated volumetric capacity significantly exceedsmore » that of carbon. In conclusion, it also exhibits excellent rate capability, delivering volumetric capacity higher than 1.6 Ah cc–1 over 140 cycles at the 1 C rate.« less

  15. Direct Synthesis of Carbon-Doped TiO2-Bronze Nanowires as Anode Materials for High Performance Lithium-Ion Batteries.

    PubMed

    Goriparti, Subrahmanyam; Miele, Ermanno; Prato, Mirko; Scarpellini, Alice; Marras, Sergio; Monaco, Simone; Toma, Andrea; Messina, Gabriele C; Alabastri, Alessandro; De Angelis, Francesco; Manna, Liberato; Capiglia, Claudio; Zaccaria, Remo Proietti

    2015-11-18

    Carbon-doped TiO2-bronze nanowires were synthesized via a facile doping mechanism and were exploited as active material for Li-ion batteries. We demonstrate that both the wire geometry and the presence of carbon doping contribute to the high electrochemical performance of these materials. Direct carbon doping for example reduces the Li-ion diffusion length and improves the electrical conductivity of the wires, as demonstrated by cycling experiments, which evidenced remarkably higher capacities and superior rate capability over the undoped nanowires. The as-prepared carbon-doped nanowires, evaluated in lithium half-cells, exhibited lithium storage capacity of ∼306 mA h g(-1) (91% of the theoretical capacity) at the current rate of 0.1C as well as excellent discharge capacity of ∼160 mAh g(-1) even at the current rate of 10 C after 1000 charge/discharge cycles. PMID:26492841

  16. Alternate anode materials for cathodic protection of steel reinforced concrete

    SciTech Connect

    Russell, James H.; Bullard, Sophie J.; Covino, Bernard S., Jr.; Cramer, Stephen D.; Holcomb, Gordon R.; Cryer, Curtis B.

    2001-01-01

    Consumable and non-consumable anodes were evaluated in the laboratory for use in cathodic protection (CP) systems for steel reinforced concrete bridges in coastal environments and in areas where deicing salts are employed. The anode materials included Zn-hydrogel and thermal-sprayed Zn, Zn-15Al, Al-12Zn-0.2In, and cobalt-sprayed Ti. These anodes were evaluated for service in both galvanic (GCP) and impressed current (ICCP) cathodic protection systems. Impressed current CP anodes were electrochemically aged at a current density 15 times as great as that used by the Oregon Department of Transportation in typical coastal ICCP systems (2.2 mA/m2 based on anode area). Increasing moisture at the anode-concrete interface reduced the operating voltage of all the anodes. Bond strength between the anodes and concrete decreased with electrochemical aging. The Zn-15Al and Al-12Zn-0.2In anodes provided adequate protection in GCP but their life was too short in the accelerated ICCP tests. Zinc had an adequate life in ICCP tests but was inadequate as a galvanic anode. Zinc-hydrogel performed well in both tests when the hydrogel was kept moist. Titanium was an excellent anode for ICCP, but is not suitable for GCP.

  17. Ceramic anode catalyst for dry methane type molten carbonate fuel cell

    NASA Astrophysics Data System (ADS)

    Tagawa, T.; Yanase, A.; Goto, S.; Yamaguchi, M.; Kondo, M.

    Oxide catalyst materials for methane oxidation were examined in order to develop the anode electrode for molten carbonate type fuel cell (MCFC). As a primary selection, oxides such as lanthanum (La 2O 3) and samarium (Sm 2O 3) were selected from screening experiments of TPD, TG and tubular reactor. Composite materials of these oxides with titanium fine powder were assembled into a cell unit for MCFC as the anode electrode. Steady-state activities were observed with these anode electrode materials when hydrogen was used as a fuel. When methane was directly charged to anode as a fuel (dry methane operation), a power generation with steady state was observed on both lanthanum and samarium composites after gradual decrease of open circuit electromotive force (OCV) and closed circuit current (CCI). The steady-state activity held as long as 144 h of continuous operation.

  18. Reduced graphene oxide/carbon nanotubes sponge: A new high capacity and long life anode material for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Yan, Dong; Xu, Xingtao; Lu, Ting; Hu, Bingwen; Chua, Daniel H. C.; Pan, Likun

    2016-06-01

    Reduced graphene oxide/carbon nanotubes (CNTs) sponge (GCNTS) is fabricated via a simple freeze drying of graphene oxide/CNTs mixed solution and subsequent thermal treatment in nitrogen atmosphere, and used as anodes for sodium-ion batteries (SIBs) for the first time. The morphology, structure and electrochemical performance of GCNTS are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, nitrogen adsorption-desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The results show that GCNTS with 20 wt % CNTs has a highest charge capacity of 436 mA h g-1 after 100 cycles at a current density of 50 mA g-1 and even at a high current density of 10 A g-1, a capacity of 195 mA h g-1 is maintained after 7440 cycles. The high capacity, excellent rate performance and long life cycling enable the GCNTS to be a promising candidate for practical SIBs.

  19. Reduced graphene oxide/carbon nanotubes sponge: A new high capacity and long life anode material for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Yan, Dong; Xu, Xingtao; Lu, Ting; Hu, Bingwen; Chua, Daniel H. C.; Pan, Likun

    2016-06-01

    Reduced graphene oxide/carbon nanotubes (CNTs) sponge (GCNTS) is fabricated via a simple freeze drying of graphene oxide/CNTs mixed solution and subsequent thermal treatment in nitrogen atmosphere, and used as anodes for sodium-ion batteries (SIBs) for the first time. The morphology, structure and electrochemical performance of GCNTS are characterized by field emission scanning electron microscopy, transmission electron microscopy, X-ray diffraction, X-ray photoelectron spectroscopy, Raman spectroscopy, nitrogen adsorption-desorption isotherms, galvanostatic charge/discharge tests, cyclic voltammetry and electrochemical impedance spectroscopy, respectively. The results show that GCNTS with 20 wt % CNTs has a highest charge capacity of 436 mA h g-1 after 100 cycles at a current density of 50 mA g-1 and even at a high current density of 10 A g-1, a capacity of 195 mA h g-1 is maintained after 7440 cycles. The high capacity, excellent rate performance and long life cycling enable the GCNTS to be a promising candidate for practical SIBs.

  20. A comparative study of graphene-coated stainless steel fiber felt and carbon cloth as anodes in MFCs.

    PubMed

    Hou, Junxian; Liu, Zhongliang; Li, Yanxia; Yang, Siqi; Zhou, Yu

    2015-05-01

    This study investigated the stainless steel-based materials and their potential in microbial fuel cells (MFCs) anode application. Herein, AISI 316L stainless steel fiber felts (SSFFs) were used as anodes in MFCs and their performance was compared with the carbon cloth anode MFCs. The experimental results showed that the unmodified carbon cloth (CC) anode had a better performance than the unmodified SSFF anode. However, after coating a thin layer of graphene (GN) on SSFF and CC, the power density of the MFC equipped with the modified SSFF was 2,143 mW m(-2), much higher than that of the graphene-modified CC-MFC which was only 1,018 mW m(-2). The experimental results proved that the use of durable metallic backbones combined with a thin layer of carbon nanoparticles offers exciting opportunities in the advancement of MFC anode design. PMID:25428842

  1. Development of Carbon Anode for Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Huang, C. -K.; Surampudi, S.; Halpert, G.

    1994-01-01

    Conventionally, rechargeable lithium cells employ a pure lithium anode. To overcome problems associated with the pure lithium electrode, it has been proposed to replace the conventional electrode with an alternative material having a greater stability with respect to the cell electrolytes. For this reason, several graphitic and coke based carbonaceous materials were evaluated as candidate anode materials...In this paper, we summarize the results of the studies on Li-ion cell development.

  2. Developments in carbon materials

    NASA Technical Reports Server (NTRS)

    Burchell, Timothy D.

    1994-01-01

    The following carbon-based materials are reviewed and their applications discussed: fullerenes; graphite (synthetic and manufactured); activated carbon fibers; and carbon-carbon composites. Carbon R&D activities at ORNL are emphasized.

  3. Silicon Whisker and Carbon Nanofiber Composite Anode

    NASA Technical Reports Server (NTRS)

    Lang, Christopher M.

    2015-01-01

    Phase II Objectives: Demonstrate production levels of grams per batch; Achieve full cell anode capacity of greater than 1,000 mAh/g at a charge rate of 10 (C/10) and 0 degree C; Establish a full cell cycle life of over 300 cycles; Display an operating temperature of negative 30 degrees C to plus 30 degrees C; Demonstrate a rate capability of C/5 or higher; Deliver to NASA three 2.5 Ah cells (energy density greater than 220 Wh/kg); Exhibit the safety features of the anode and full cells; Design a 1 kWh prismatic battery pack.

  4. One-pot solvothermal synthesis of graphene wrapped rice-like ferrous carbonate nanoparticles as anode materials for high energy lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Fan; Zhang, Ruihan; Feng, Jinkui; Ci, Lijie; Xiong, Shenglin; Yang, Jian; Qian, Yitai; Li, Lifei

    2014-11-01

    Well dispersed rice-like FeCO3 nanoparticles were produced and combined with reduced graphene oxide (RGO) via a one-pot solvothermal route. SEM characterization shows that rice-like FeCO3 nanoparticles are homogeneously anchored on the surface of the graphene nanosheets; the addition of RGO is helpful to form a uniform morphology and reduce the particle size of FeCO3 to nano-grade. As anode materials for lithium-ion batteries, the FeCO3/RGO nanocomposites exhibit significantly improved lithium storage properties with a large reversible capacity of 1345 mA h g-1 for the first cycle and a capacity retention of 1224 mA h g-1 after 50 cycles with a good rate capability compared with pure FeCO3 particles. The superior electrochemical performance of the FeCO3/RGO nanocomposite electrode compared to the pure FeCO3 electrode can be attributed to the well dispersed RGO which enhances the electronic conductivity and accommodates the volume change during the conversion reactions. Our study shows that the FeCO3/RGO nanocomposite could be a suitable candidate for high capacity lithium-ion batteries.

  5. One-pot solvothermal synthesis of graphene wrapped rice-like ferrous carbonate nanoparticles as anode materials for high energy lithium-ion batteries.

    PubMed

    Zhang, Fan; Zhang, Ruihan; Feng, Jinkui; Ci, Lijie; Xiong, Shenglin; Yang, Jian; Qian, Yitai; Li, Lifei

    2015-01-01

    Well dispersed rice-like FeCO3 nanoparticles were produced and combined with reduced graphene oxide (RGO) via a one-pot solvothermal route. SEM characterization shows that rice-like FeCO3 nanoparticles are homogeneously anchored on the surface of the graphene nanosheets; the addition of RGO is helpful to form a uniform morphology and reduce the particle size of FeCO3 to nano-grade. As anode materials for lithium-ion batteries, the FeCO3/RGO nanocomposites exhibit significantly improved lithium storage properties with a large reversible capacity of 1345 mA h g(-1) for the first cycle and a capacity retention of 1224 mA h g(-1) after 50 cycles with a good rate capability compared with pure FeCO3 particles. The superior electrochemical performance of the FeCO3/RGO nanocomposite electrode compared to the pure FeCO3 electrode can be attributed to the well dispersed RGO which enhances the electronic conductivity and accommodates the volume change during the conversion reactions. Our study shows that the FeCO3/RGO nanocomposite could be a suitable candidate for high capacity lithium-ion batteries. PMID:25406864

  6. Antimony/Graphitic Carbon Composite Anode for High-Performance Sodium-Ion Batteries.

    PubMed

    Zhao, Xin; Vail, Sean A; Lu, Yuhao; Song, Jie; Pan, Wei; Evans, David R; Lee, Jong-Jan

    2016-06-01

    Although the room-temperature rechargeable sodium-ion battery has emerged as an attractive alternative energy storage solution for large-scale deployment, major challenges toward practical sodium-ion battery technology remain including identification and engineering of anode materials that are both technologically feasible and economical. Herein, an antimony-based anode is developed by incorporating antimony into graphitic carbon matrices using low-cost materials and scalable processes. The composite anode exhibits excellent overall performance in terms of packing density, fast charge/discharge capability and cyclability, which is enabled by the conductive and compact graphitic network. A full cell design featuring this composite anode with a hexacyanometallate cathode achieves superior power output and low polarization, which offers the potential for realizing a high-performance, cost-effective sodium-ion battery. PMID:27172376

  7. An activated microporous carbon prepared from phenol-melamine-formaldehyde resin for lithium ion battery anode

    SciTech Connect

    Zhu, Yinhai; Xiang, Xiaoxia; Liu, Enhui; Wu, Yuhu; Xie, Hui; Wu, Zhilian; Tian, Yingying

    2012-08-15

    Highlights: ► Microporous carbon was prepared by chemical activation of phenol-melamine-formaldehyde resin. ► Activation leads to high surface area, well-developed micropores. ► Micropores lead to strong intercalation between carbon and lithium ion. ► Large surface area promotes to improve the lithium storage capacity. -- Abstract: Microporous carbon anode materials were prepared from phenol-melamine-formaldehyde resin by ZnCl{sub 2} and KOH activation. The physicochemical properties of the obtained carbon materials were characterized by scanning electron microscope, X-ray diffraction, Brunauer–Emmett–Teller, and elemental analysis. The electrochemical properties of the microporous carbon as anode materials in lithium ion secondary batteries were evaluated. At a current density of 100 mA g{sup −1}, the carbon without activation shows a first discharge capacity of 515 mAh g{sup −1}. After activation, the capacity improved obviously. The first discharge capacity of the carbon prepared by ZnCl{sub 2} and KOH activation was 1010 and 2085 mAh g{sup −1}, respectively. The reversible capacity of the carbon prepared by KOH activation was still as high as 717 mAh g{sup −1} after 20 cycles, which was much better than that activated by ZnCl{sub 2}. These results demonstrated that it may be a promising candidate as an anode material for lithium ion secondary batteries.

  8. Nanocomposite anode materials for sodium-ion batteries

    DOEpatents

    Manthiram, Arumugam; Kim Il, Tae; Allcorn, Eric

    2016-06-14

    The disclosure relates to an anode material for a sodium-ion battery having the general formula AO.sub.x--C or AC.sub.x--C, where A is aluminum (Al), magnesium (Mg), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), zirconium (Zr), molybdenum (Mo), tungsten (W), niobium (Nb), tantalum (Ta), silicon (Si), or any combinations thereof. The anode material also contains an electrochemically active nanoparticles within the matrix. The nanoparticle may react with sodium ion (Na.sup.+) when placed in the anode of a sodium-ion battery. In more specific embodiments, the anode material may have the general formula M.sub.ySb-M'O.sub.x--C, Sb-MO.sub.x--C, M.sub.ySn-M'C.sub.x--C, or Sn-MC.sub.x--C. The disclosure also relates to rechargeable sodium-ion batteries containing these materials and methods of making these materials.

  9. Foamed mesoporous carbon/silicon composite nanofiber anode for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Yuxin; Wen, Xiufang; Chen, Juan; Wang, Shengnian

    2015-05-01

    A new porous composite nanofiber manufacturing route, combining electrospinning and foaming processes, was developed. In this process, aluminum acetylacetonate (AACA) was introduced as the foaming agent in nanofibers made of polyacrylonitrile (PAN)/silicon (Si) nanoparticles. PAN/Si composite nanofibers were first produced through an electrospinning process and mesopores were then generated by foaming nanofibers via AACA sublimation. After further carbonization, the obtained mesoporous carbon/silicon composite nanofiber mats were tested as the anode material for lithium ion batteries. Within this composite anode, mesopores provide needed buffering space to accommodate the large volume expansion and consequent stress induced inside silicon during lithiation. This effectively mitigates silicon pulverization issue and helps achieve higher reversible capacity and better capacity retention in later battery tests when compared with anodes made of nonporous composites nanofibers and carbon nanofibers alone.

  10. SnO2/carbon nanotube nanocomposites synthesized in supercritical fluids: highly efficient materials for use as a chemical sensor and as the anode of a lithium-ion battery

    NASA Astrophysics Data System (ADS)

    An, Guimin; Na, Na; Zhang, Xinrong; Miao, Zhenjiang; Miao, Shiding; Ding, Kunlun; Liu, Zhimin

    2007-10-01

    SnO2/multi-walled carbon nanotube (MWCNT) nanocomposites were prepared via oxidation of SnCl2 in a supercritical CO2-methanol mixture containing MWCNTs. The as-prepared nanocomposites were characterized by means of x-ray diffraction, x-ray photoelectron spectroscopy, and transmission electron microscopy. It was indicated that SnO2 nanoparticles with size of 3-5 nm were uniformly and tightly decorated on the MWCNTs. The chemiluminescence characteristic to H2S and electrochemical performance of the as-prepared SnO2/MWCNT composites were investigated. The SnO2/MWCNT composites exhibited extremely high efficiency for detecting H2S, and also displayed good electrochemical performance as the anode material in a lithium-ion battery.

  11. Anode Materials for Rechargeable Li-Ion Batteries

    SciTech Connect

    Fultz, B.

    2001-01-12

    This research is on materials for anodes and cathodes in electrochemical cells. The work is a mix of electrochemical measurements and analysis of the materials by transmission electron microscopy and x-ray diffractometry. At present, our experimental work involves only materials for Li storage, but we have been writing papers from our previous work on hydrogen-storage materials.

  12. A facile synthesis of zinc oxide/multiwalled carbon nanotube nanocomposite lithium ion battery anodes by sol-gel method

    NASA Astrophysics Data System (ADS)

    Köse, Hilal; Karaal, Şeyma; Aydın, Ali Osman; Akbulut, Hatem

    2015-11-01

    Free standing zinc oxide (ZnO) and multiwalled carbon nanotube (MWCNT) nanocomposite materials are prepared by a sol gel technique giving a new high capacity anode material for lithium ion batteries. Free-standing ZnO/MWCNT nanocomposite anodes with two different chelating agent additives, triethanolamine (TEA) and glycerin (GLY), yield different electrochemical performances. Field emission gun scanning electron microscopy (FEG-SEM), energy dispersive X-ray spectrometer (EDS), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analyses reveal the produced anode electrodes exhibit a unique structure of ZnO coating on the MWCNT surfaces. Li-ion cell assembly using a ZnO/MWCNT/GLY free-standing anode and Li metal cathode possesses the best discharge capacity, remaining as high as 460 mAh g-1 after 100 cycles. This core-shell structured anode can offer increased energy storage and performance over conventional anodes in Li-ion batteries.

  13. In Situ Carbonized Cellulose-Based Hybrid Film as Flexible Paper Anode for Lithium-Ion Batteries.

    PubMed

    Cao, Shaomei; Feng, Xin; Song, Yuanyuan; Liu, Hongjiang; Miao, Miao; Fang, Jianhui; Shi, Liyi

    2016-01-20

    Flexible free-standing carbonized cellulose-based hybrid film is integrately designed and served both as paper anode and as lightweight current collector for lithium-ion batteries. The well-supported heterogeneous nanoarchitecture is constructed from Li4Ti5O12 (LTO), carbonized cellulose nanofiber (C-CNF) and carbon nanotubes (CNTs) using by a pressured extrusion papermaking method followed by in situ carbonization under argon atmospheres. The in situ carbonization of CNF/CNT hybrid film immobilized with uniform-dispersed LTO results in a dramatic improvement in the electrical conductivity and specific surface area, so that the carbonized paper anode exhibits extraordinary rate and cycling performance compared to the paper anode without carbonization. The flexible, lightweight, single-layer cellulose-based hybrid films after carbonization can be utilized as promising electrode materials for high-performance, low-cost, and environmentally friendly lithium-ion batteries. PMID:26727586

  14. Crystalline structure transformation of carbon anodes during gasification

    SciTech Connect

    Kien N. Tran; Adam J. Berkovich; Alan Tomsett; Suresh K. Bhatia

    2008-05-15

    The crystalline structure transformation of five carbon anodes during gasification in air and carbon dioxide was studied using quantitative X-ray diffraction (XRD) analysis and high-resolution transmission electron microscopy (HRTEM). XRD analysis and HRTEM observations confirmed that anodes have a highly ordered graphitic structure. The examination of partially gasified samples indicated that crystalline structure transformation occurred in two stages during gasification. The first stage involved the consumption of disorganized carbon matter in the initial 15% conversion. Oxygen was found to be more reactive toward disorganized carbon at this stage of the gasification process compared to carbon dioxide. Following this stage, as more carbon was consumed, especially with the removal of smaller crystallites, it was found that the crystalline structure became more ordered with increasing conversion levels. This is due to the merging of neighboring crystallites, required to maintain the minimum energy configuration. In addition, the interaction between the pitch and the coke components was found to be strongly linked to the initial coke structure. 'Stress graphitization' occurred at the pitch-coke interface, which helps to enhance the structural development of the anodes. 26 refs., 9 figs., 3 tabs.

  15. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C. Robles; Okonkwo, Anderson O.; Hobosyan, Mkhitar; Martirosyan, Karen S.

    2014-07-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  16. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries

    PubMed Central

    2014-01-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  17. Low-cost carbon-silicon nanocomposite anodes for lithium ion batteries.

    PubMed

    Badi, Nacer; Erra, Abhinay Reddy; Hernandez, Francisco C Robles; Okonkwo, Anderson O; Hobosyan, Mkhitar; Martirosyan, Karen S

    2014-01-01

    The specific energy of the existing lithium ion battery cells is limited because intercalation electrodes made of activated carbon (AC) materials have limited lithium ion storage capacities. Carbon nanotubes, graphene, and carbon nanofibers are the most sought alternatives to replace AC materials but their synthesis cost makes them highly prohibitive. Silicon has recently emerged as a strong candidate to replace existing graphite anodes due to its inherently large specific capacity and low working potential. However, pure silicon electrodes have shown poor mechanical integrity due to the dramatic expansion of the material during battery operation. This results in high irreversible capacity and short cycle life. We report on the synthesis and use of carbon and hybrid carbon-silicon nanostructures made by a simplified thermo-mechanical milling process to produce low-cost high-energy lithium ion battery anodes. Our work is based on an abundant, cost-effective, and easy-to-launch source of carbon soot having amorphous nature in combination with scrap silicon with crystalline nature. The carbon soot is transformed in situ into graphene and graphitic carbon during mechanical milling leading to superior elastic properties. Micro-Raman mapping shows a well-dispersed microstructure for both carbon and silicon. The fabricated composites are used for battery anodes, and the results are compared with commercial anodes from MTI Corporation. The anodes are integrated in batteries and tested; the results are compared to those seen in commercial batteries. For quick laboratory assessment, all electrochemical cells were fabricated under available environment conditions and they were tested at room temperature. Initial electrochemical analysis results on specific capacity, efficiency, and cyclability in comparison to currently available AC counterpart are promising to advance cost-effective commercial lithium ion battery technology. The electrochemical performance observed for

  18. Measurement of anode surface temperature in carbon nanomaterial production by arc discharge method

    SciTech Connect

    Liang, Feng; Tanaka, Manabu; Choi, Sooseok; Watanabe, Takayuki

    2014-12-15

    Highlights: • We measured the temperature of anode surface by two-color pyrometry combined with a high speed camera successfully. • Growth temperature of pyrolytic graphite, MWNTs, and nano-graphite particles were in ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. • High temperature contributes to form thermodynamically unstable material. - Abstract: Nano-graphite particles, multi-wall carbon nanotube (MWNT), and pyrolytic graphite were prepared at different positions of the anode surface in an arc discharge. Graphite electrodes were employed for the arc discharge under helium environment at atmospheric pressure. Nano-sized carbon products were characterized by scanning electron microscopy and transmission electron microscopy. During the arc discharge, two-color pyrometry combined with a high-speed camera was conducted to measure the temperature distribution of the anode surface. The growth temperature of pyrolytic graphite, MWNT, and nano-graphite particles were in the ranges of 2400–2600 K, 2600–2700 K, and 2700–3500 K, respectively. The local temperature of anode surface is a critical parameter to determine the products with different morphologies. The formation mechanism of these carbon nanomaterials is suggested based on the local temperature of anode surface and their thermodynamic stability.

  19. Graphite coated with manganese oxide/multiwall carbon nanotubes composites as anodes in marine benthic microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Fu, Yubin; Yu, Jian; Zhang, Yelong; Meng, Yao

    2014-10-01

    Improving anode performance is of great significance to scale up benthic microbial fuel cells (BMFCs) for its marine application to drive oceanography instruments. In this study, manganese oxide (MnO2)/multiwall carbon nanotubes (MWCNTs) composites are prepared to be as novel anodes in the BMFCs via a direct redox reaction between permanganate ions (MnO4-) and MWCNTs. The results indicate that the MnO2/MWCNTs anode has a better wettability, greater kinetic activity and higher power density than that of the plain graphite (PG) anode. It is noted that the MnO2 (50% weight percent)/MWCNTs anode shows the highest electrochemical performance among them and will be a promising material for improving bioelectricity production of the BMFCs. Finally, a synergistic mechanism of electron transfer shuttle of Mn ions and their redox reactions in the interface between modified anode and bacteria biofilm are proposed to explain its excellent electrochemical performance.

  20. Three-dimensional porous carbon nanotube sponges for high-performance anodes of microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Erbay, Celal; Yang, Gang; de Figueiredo, Paul; Sadr, Reza; Yu, Choongho; Han, Arum

    2015-12-01

    Highly-porous, light-weight, and inexpensive three-dimensional (3D) sponges consisting of interconnected carbon nanotubes (CNTs) without base materials are synthesized with a facile and scalable one-step chemical vapor deposition process as anode of microbial fuel cells (MFCs). The MFCs generates higher power densities of 2150 W m-3 (per anode volume) or 170 W m-3 (per anode chamber volume), comparable to those of commercial 3D carbon felt electrodes under the same conditions. The high performances are due to excellent charge transfer between CNTs and microbes owing to 13 times lower charge transfer resistance compared to that of carbon felt. The material cost of producing these CNT sponge estimates to be ∼0.1/gCNT, significantly lower than that of other methods. In addition, the high production rate of about 3.6 g h-1 compared to typical production rate of 0.02 g h-1 of other CNT-based materials makes this process economically viable. The one-step synthesis method allowing self-assembly of 3D CNT sponges as they grow is low cost and scalable, making this a promising method for manufacturing high-performance anodes of MFCs, with broad applicability to microbial electrochemical systems in general.

  1. Review on anode material development in solid oxide fuel cells

    NASA Astrophysics Data System (ADS)

    Siong @ Mahmud, Lily; Muchtar, Andanastuti; Somalu, Mahendra Rao

    2015-05-01

    New developments in technology require highly efficient, affordable, and green electrical energy. The materials to be used must also be reusable and environment friendly. These characteristics are among the major factors that may lead to the production of new and highly efficient power generation systems. Solid oxide fuel cells (SOFCs) have become major devices in producing electricity that emphasize the advance usage of material science and technological development. As part of the key elements of SOFCs, anodes have the primary function of stimulating the electrochemical oxidation of fuel. In this review, the progress in developing anode materials for SOFCs is briefly discussed.

  2. Carbon treated commercial aluminium alloys as anodes for aluminium-air batteries in sodium chloride electrolyte

    NASA Astrophysics Data System (ADS)

    Pino, M.; Herranz, D.; Chacón, J.; Fatás, E.; Ocón, P.

    2016-09-01

    An easy treatment based in carbon layer deposition into aluminium alloys is presented to enhance the performance of Al-air primary batteries with neutral pH electrolyte. The jellification of aluminate in the anode surface is described and avoided by the carbon covering. Treated commercial Al alloys namely Al1085 and Al7475 are tested as anodes achieving specific capacities above 1.2 Ah g-1vs 0.5 Ah g-1 without carbon covering. The influence of the binder proportion in the treatment as well as different carbonaceous materials, Carbon Black, Graphene and Pyrolytic Graphite are evaluated as candidates for the covering. Current densities of 1-10 mA cm-2 are measured and the influence of the alloy explored. A final battery design of 4 cells in series is presented for discharges with a voltage plateau of 2 V and 1 Wh g-1 energy density.

  3. Electrochemically Expandable Soft Carbon as Anodes for Na-Ion Batteries

    PubMed Central

    2015-01-01

    Na-ion batteries (NIBs) have attracted great attention for scalable electrical energy storage considering the abundance and wide availability of Na resources. However, it remains elusive whether carbon anodes can achieve the similar scale of successes in Na-ion batteries as in Li-ion batteries. Currently, much attention is focused on hard carbon while soft carbon is generally considered a poor choice. In this study, we discover that soft carbon can be a high-rate anode in NIBs if the preparation conditions are carefully chosen. Furthermore, we discover that the turbostratic lattice of soft carbon is electrochemically expandable, where d-spacing rises from 3.6 to 4.2 Å. Such a scale of lattice expansion only due to the Na-ion insertion was not known for carbon materials. It is further learned that portions of such lattice expansion are highly reversible, resulting in excellent cycling performance. Moreover, soft carbon delivers a good capacity at potentials above 0.2 V, which enables an intrinsically dendrite-free anode for NIBs. PMID:27163016

  4. Surface treated natural graphite as anode material for high-power Li-ion battery applications.

    SciTech Connect

    Liu, J.; Vissers, D. R.; Amine, K.; Barsukov, I. V.; Henry, F.; Doniger, J.; Chemical Engineering; Superior Graphite Co.

    2006-01-01

    High power application of Li-ion battery in hybrid electrical vehicles requires low cost and safe cell materials. Among the various carbon anode materials used in lithium ion batteries, natural graphite shows the most promise with advantages in performance and cost. However, natural graphite is not compatible with propylene carbonate (PC)-based electrolytes, which have a lower melting point and improved safety characteristics. The problem with it is that the molecules of propylene carbonate intercalate with Li+ into graphite, and that frequently leads to the exfoliation of the graphite matrix.

  5. Composit, Nanoparticle-Based Anode material for Li-ion Batteries Applied in Hybrid Electric (HEV's)

    SciTech Connect

    Dr. Malgorzata Gulbinska

    2009-08-24

    Lithium-ion batteries are promising energy storage devices in hybrid and electric vehicles with high specific energy values ({approx}150 Wh/kg), energy density ({approx}400 Wh/L), and long cycle life (>15 years). However, applications in hybrid and electric vehicles require increased energy density and improved low-temperature (<-10 C) performance. Silicon-based anodes are inexpensive, environmentally benign, and offer excellent theoretical capacity values ({approx}4000 mAh/g), leading to significantly less anode material and thus increasing the overall energy density value for the complete battery (>500 Wh/L). However, tremendous volume changes occur during cycling of pure silicon-based anodes. The expansion and contraction of these silicon particles causes them to fracture and lose electrical contact to the current collector ultimately severely limiting their cycle life. In Phase I of this project Yardney Technical Products, Inc. proposed development of a carbon/nano-silicon composite anode material with improved energy density and silicon's cycleability. In the carbon/nano-Si composite, silicon nanoparticles were embedded in a partially-graphitized carbonaceous matrix. The cycle life of anode material would be extended by decreasing the average particle size of active material (silicon) and by encapsulation of silicon nanoparticles in a ductile carbonaceous matrix. Decreasing the average particle size to a nano-region would also shorten Li-ion diffusion path and thus improve rate capability of the silicon-based anodes. Improved chemical inertness towards PC-based, low-temperature electrolytes was expected as an additional benefit of a thin, partially graphitized coating around the active electrode material.

  6. Binder-free graphene and manganese oxide coated carbon felt anode for high-performance microbial fuel cell.

    PubMed

    Zhang, Changyong; Liang, Peng; Yang, Xufei; Jiang, Yong; Bian, Yanhong; Chen, Chengmeng; Zhang, Xiaoyuan; Huang, Xia

    2016-07-15

    A novel anode was developed by coating reduced graphene oxide (rGO) and manganese oxide (MnO2) composite on the carbon felt (CF) surface. With a large surface area and excellent electrical conductivity, this binder-free anode was found to effectively enhance the enrichment and growth of electrochemically active bacteria and facilitate the extracellular electron transfer from the bacteria to the anode. A microbial fuel cell (MFC) equipped with the rGO/MnO2/CF anode delivered a maximum power density of 2065mWm(-2), 154% higher than that with a bare CF anode. The internal resistance of the MFC with this novel anode was 79Ω, 66% lower than the regular one's (234Ω). Cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) analyses affirmed that the rGO/MnO2 composite significantly increased the anodic reaction rates and facilitated the electron transfer from the bacteria to the anode. The findings from this study suggest that the rGO/MnO2/CF anode, fabricated via a simple dip-coating and electro-deposition process, could be a promising anode material for high-performance MFC applications. PMID:26918615

  7. Theoretical Limits of Energy Density in Silicon-Carbon Composite Anode Based Lithium Ion Batteries

    PubMed Central

    Dash, Ranjan; Pannala, Sreekanth

    2016-01-01

    Silicon (Si) is under consideration as a potential next-generation anode material for the lithium ion battery (LIB). Experimental reports of up to 40% increase in energy density of Si anode based LIBs (Si-LIBs) have been reported in literature. However, this increase in energy density is achieved when the Si-LIB is allowed to swell (volumetrically expand) more than graphite based LIB (graphite-LIB) and beyond practical limits. The volume expansion of LIB electrodes should be negligible for applications such as automotive or mobile devices. We determine the theoretical bounds of Si composition in a Si–carbon composite (SCC) based anode to maximize the volumetric energy density of a LIB by constraining the external dimensions of the anode during charging. The porosity of the SCC anode is adjusted to accommodate the volume expansion during lithiation. The calculated threshold value of Si was then used to determine the possible volumetric energy densities of LIBs with SCC anode (SCC-LIBs) and the potential improvement over graphite-LIBs. The level of improvement in volumetric and gravimetric energy density of SCC-LIBs with constrained volume is predicted to be less than 10% to ensure the battery has similar power characteristics of graphite-LIBs. PMID:27311811

  8. Theoretical Limits of Energy Density in Silicon-Carbon Composite Anode Based Lithium Ion Batteries.

    PubMed

    Dash, Ranjan; Pannala, Sreekanth

    2016-01-01

    Silicon (Si) is under consideration as a potential next-generation anode material for the lithium ion battery (LIB). Experimental reports of up to 40% increase in energy density of Si anode based LIBs (Si-LIBs) have been reported in literature. However, this increase in energy density is achieved when the Si-LIB is allowed to swell (volumetrically expand) more than graphite based LIB (graphite-LIB) and beyond practical limits. The volume expansion of LIB electrodes should be negligible for applications such as automotive or mobile devices. We determine the theoretical bounds of Si composition in a Si-carbon composite (SCC) based anode to maximize the volumetric energy density of a LIB by constraining the external dimensions of the anode during charging. The porosity of the SCC anode is adjusted to accommodate the volume expansion during lithiation. The calculated threshold value of Si was then used to determine the possible volumetric energy densities of LIBs with SCC anode (SCC-LIBs) and the potential improvement over graphite-LIBs. The level of improvement in volumetric and gravimetric energy density of SCC-LIBs with constrained volume is predicted to be less than 10% to ensure the battery has similar power characteristics of graphite-LIBs. PMID:27311811

  9. Theoretical Limits of Energy Density in Silicon-Carbon Composite Anode Based Lithium Ion Batteries

    NASA Astrophysics Data System (ADS)

    Dash, Ranjan; Pannala, Sreekanth

    2016-06-01

    Silicon (Si) is under consideration as a potential next-generation anode material for the lithium ion battery (LIB). Experimental reports of up to 40% increase in energy density of Si anode based LIBs (Si-LIBs) have been reported in literature. However, this increase in energy density is achieved when the Si-LIB is allowed to swell (volumetrically expand) more than graphite based LIB (graphite-LIB) and beyond practical limits. The volume expansion of LIB electrodes should be negligible for applications such as automotive or mobile devices. We determine the theoretical bounds of Si composition in a Si–carbon composite (SCC) based anode to maximize the volumetric energy density of a LIB by constraining the external dimensions of the anode during charging. The porosity of the SCC anode is adjusted to accommodate the volume expansion during lithiation. The calculated threshold value of Si was then used to determine the possible volumetric energy densities of LIBs with SCC anode (SCC-LIBs) and the potential improvement over graphite-LIBs. The level of improvement in volumetric and gravimetric energy density of SCC-LIBs with constrained volume is predicted to be less than 10% to ensure the battery has similar power characteristics of graphite-LIBs.

  10. High capacity tin-iron oxide-carbon nanostructured anode for advanced lithium ion battery

    NASA Astrophysics Data System (ADS)

    Verrelli, Roberta; Hassoun, Jusef

    2015-12-01

    A novel nanostructured Sn-Fe2O3-C anode material, prepared by high-energy ball milling, is here originally presented. The anode benefits from a unique morphology consisting in Fe2O3 and Sn active nanoparticles embedded in a conductive buffer carbon matrix of micrometric size. Furthermore, the Sn metal particles, revealed as amorphous according to X-ray diffraction measurement, show a size lower than 10 nm by transmission electron microscopy. The optimal combination of nano-scale active materials and micrometric electrode configuration of the Sn-Fe2O3-C anode reflects into remarkable electrochemical performances in lithium cell, with specific capacity content higher than 900 mAh g-1 at 1C rate (810 mA g-1) and coulombic efficiency approaching 100% for 100 cycles. The anode, based on a combination of lithium conversion, alloying and intercalation reactions, exhibits exceptional rate-capability, stably delivering more than 400 mAh g-1 at the very high current density of 4 A g-1. In order to fully confirm the suitability of the developed Sn-Fe2O3-C material as anode for lithium ion battery, the electrode is preliminarily studied in combination with a high voltage LiNi0.5Mn1.5O4 cathode in a full cell stably and efficiently operating with a 3.7 V working voltage and a capacity exceeding 100 mAh g-1.

  11. Liquid-phase plasma synthesis of silicon quantum dots embedded in carbon matrix for lithium battery anodes

    SciTech Connect

    Wei, Ying; Yu, Hang; Li, Haitao; Ming, Hai; Pan, Keming; Huang, Hui; Liu, Yang; Kang, Zhenhui

    2013-10-15

    Graphical abstract: - Highlights: • Silicon quantum dots embedded in carbon matrix (SiQDs/C) were fabricated. • SiQDs/C exhibits excellent battery performance as anode materials with high specific capacity. • The good performance was attributed to the marriage of small sized SiQDs and carbon. - Abstract: Silicon quantum dots embedded in carbon matrix (SiQDs/C) nanocomposites were prepared by a novel liquid-phase plasma assisted synthetic process. The SiQDs/C nanocomposites were demonstrated to show high specific capacity, good cycling life and high coulmbic efficiency as anode materials for lithium-ion battery.

  12. Color Anodizing of Titanium Coated Rolled Carbon Steel Plate

    SciTech Connect

    Sarajan, Zohair; Mobarakeh, Hooman Nikbakht; Namiranian, Sohrab

    2011-12-26

    As an important kind of structural materials, the titanium cladded steel plates have the advantages of both metals and have been applied in aviation, spaceflight, chemical and nuclear industries. In this study, the specimens which were prepared under soldering mechanism during rolling were anodized by electrochemical process under a given conditions. The color anodizing takes place by physical phenomenon of color interference. Part of incident light on the titanium oxide is reflected and the other part reflects inside coated titanium layer. Major part of the light which reflects from titanium-oxide interface, reflects again inside of the oxide layer.

  13. Modification of carbon nanotubes by CuO-doped NiO nanocomposite for use as an anode material for lithium-ion batteries

    SciTech Connect

    Mustansar Abbas, Syed; Tajammul Hussain, Syed; Ali, Saqib; Ahmad, Nisar; Ali, Nisar; Abbas, Saghir; Ali, Zulfiqar

    2013-06-15

    CuO-doped NiO (CuNiO) with porous hexagonal morphology is fabricated via a modified in-situ co-precipitation method and its nanocomposite is prepared with carbon nanotubes (CNTs). The electrochemical properties of CuNiO/CNT nanocomposite are investigated by cyclic voltammetry (CV), galvanostatic charge–discharge tests and electrochemical impedance spectroscopy (EIS). Since Cu can both act as conductor and a catalyst, the CuNiO/CNT nanocomposite exhibits higher initial coulombic efficiency (82.7% of the 2nd cycle) and better capacity retention (78.6% on 50th cycle) than bare CuNiO (78.9% of the 2nd cycle), CuO/CNT (76.8% of the 2nd cycle) and NiO/CNT (77.7% of the 2nd cycle) at the current density of 100 mA /g. This high capacity and good cycling ability is attributed to the partial substitution of Cu{sup +2} for Ni{sup +2}, resulting in an increase of holes concentration, and therefore improved p-type conductivity along with an intimate interaction with CNTs providing large surface area, excellent conduction, mechanical strength and chemical stability. - Graphical abstract: The porous CuNiO/CNT nanocomposite synthesized via a modified co-precipitation method in combination with subsequent calcination was applied in the negative electrode materials for lithium-ion batteries and exhibited high electrochemical performance. - Highlights: • CuO doped NiO/CNTs nano composite is achieved via a simple co-precipitation method. • Monodispersity, shape and sizes of sample particles is specifically controlled. • Good quality adhesion between CNTs and CuNiO is visible from TEM image. • High electrochemical performance is achieved. • Discharge capacity of 686 mA h/g after 50 cycles with coulombic efficiency (82.5%)

  14. A chronoamperometric study of anodic processes at various types of carbon anode in Al[sub 2]O[sub 3]-Na[sub 3]AlF[sub 6] melts used in the electrolytic production of aluminum

    SciTech Connect

    Djokic, S.S.; Conway, B.E. . Dept. of Chemistry); Belliveau, T.F. . Arvida Research and Development Centre)

    1994-08-01

    The performance of four graphites and glassy carbon as sensor anode materials in chronoamperometry experiments for possible determination of Al[sub 2]O[sub 3] were comparatively examined in alumina-cryolite melts at 1,010 C. With graphite anode materials, the anode process(es) is (are) not fully diffusion controlled nor are the results adequately reproducible. Only at glassy carbon is (are) the anodic process(es) diffusion controlled. Consequently, at glassy-carbon sensor anodes, the dependence of the response current function on Al[sub 2]O[sub 3] concentration is found to be approximately linear. The presence or absence of Al metal, dissolved in the melt, as arises in the practical technology of electrolytic aluminum smelting, has a significant effect on the results due mainly to background current contributions from oxidation of dissolved Al.

  15. One-pot synthesis of carbon-coated nanosized LiTi2(PO4)3 as anode materials for aqueous lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Liu, Zhantao; Qin, Xusong; Xu, Hui; Chen, Guohua

    2015-10-01

    In this study, a one-pot sintering process incorporating sol-gel preparation route and in-situ carbon coating was proposed for the synthesis of carbon-coated nanosized LiTi2(PO4)3. Experimental results show that the prepared LiTi2(PO4)3 particles are of high crystallinity and well-coated by turbostratic carbon. Attributed to nanosized particles and enhanced conductivity provided by turbostratic carbon coating, the carbon-coated LiTi2(PO4)3 showed high rate performance and good cycling life in aqueous electrolyte. Particularly, the carbon-coated LiTi2(PO4)3 exhibited initial specific capacities of 103 and 89 mAh g-1, and retained 80.6% and 97% of the initial capacities after 120 cycles at 1C and 10C in aqueous electrolyte, respectively. The high rate performance and good cycling life of carbon-coated LiTi2(PO4)3 in aqueous electrolyte reveal its potential as negative electrode in aqueous lithium-ion batteries for electric vehicles and industrial-scale energy storage systems.

  16. The superior cycling performance of the hydrothermal synthesized carbon-coated ZnO as anode material for zinc-nickel secondary cells

    NASA Astrophysics Data System (ADS)

    Feng, Zhaobin; Yang, Zhanhong; Huang, Jianhang; Xie, Xiaoe; Zhang, Zheng

    2015-02-01

    Carbon-coated ZnO is synthesized by the hydrothermal method. The X-ray diffraction (XRD), scanning electron microscope (SEM), high resolution transmission electron microscopy (HRTEM) and energy dispersive X-ray analysis (EDX) tests indicate that carbon is uniformly coated on the surface of the ZnO particle. And the crystal form of ZnO isn't changed. The effects of carbon layer on the electrochemical performances of ZnO have also been investigated by the charge/discharge cycling test, cyclic voltammetry (CV), Tafel polarization curves and electrochemical impedance spectroscope (EIS) tests. The CV curves at different scan rates exhibit that carbon-coated ZnO has the superior reversibility at high scan rate. The charge/discharge cycling tests under different charge/discharge rates show, even if at high-rate, the cycling performance and specific discharge capacity of carbon-coated ZnO are also superior to that of bare ZnO. The Tafel polarization curves and electrochemical impedance spectroscope (EIS) verify that the carbon layer can improve the anti-corrosion and charge-transfer performances of ZnO. The different rate experiments indicate that, compared with the increase of the conductivity, the effect of carbon layer on improving the anti-corrosion performance of ZnO plays a more dominating role in improving the electrochemical performances of ZnO at low charge/discharge rate.

  17. One-pot synthesis of silicon nanoparticles trapped in ordered mesoporous carbon for use as an anode material in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Park, Junsu; Kim, Gil-Pyo; Nam, Inho; Park, Soomin; Yi, Jongheop

    2013-01-01

    Silicon nanoparticles trapped in an ordered mesoporous carbon composite were prepared by a one-step self-assembly with solvent evaporation using the triblock copolymer Pluronic F127 and a resorcinol-formaldehyde polymer as the templating agent and carbon precursor respectively. Such a one-pot synthesis of Si/ordered mesoporous carbon nanocomposite is suitable for large-scale synthesis. Characterization confirmed that the Si nanoparticles were trapped in the ordered mesoporous carbon, as evidenced by transmission electron microscopy, x-ray diffraction analysis and nitrogen sorption isotherms. The composite showed a high reversible capacity above 700 mA h g-1 during 50 cycles at 2 A g-1. The improved electrochemical performance of the composite can be ascribed to the buffering effect of spaces formed in the ordered pore channels during the volume expansion of silicon and the rapid movement of lithium ions through the uniform cylindrical pore structure of the mesopores.

  18. Silk-regulated hierarchical hollow magnetite/carbon nanocomposite spheroids for lithium-ion battery anodes.

    PubMed

    Sheng, Weiqin; Zhu, Guobin; Kaplan, David L; Cao, Chuanbao; Zhu, Hesun; Lu, Qiang

    2015-03-20

    Hierarchical olive-like structured carbon-Fe3O4 nanocomposite particles composed of a hollow interior and a carbon coated surface are prepared by a facile, silk protein-assisted hydrothermal method. Silk nanofibers as templates and carbon precursors first regulate the formation of hollow Fe2O3 microspheres and then they are converted into carbon by a reduction process into Fe3O4. This process significantly simplifies the fabrication and carbon coating processes to form complex hollow structures. When tested as anode materials for lithium-ion batteries, these hollow carbon-coated particles exhibit high capacity (900 mAh g(-1)), excellent cycle stability (180 cycles) and rate performance due to their unique hierarchical hollow structure and carbon coating. PMID:25706314

  19. Silk-regulated hierarchical hollow magnetite/carbon nanocomposite spheroids for lithium ion battery anodes

    PubMed Central

    Sheng, Weiqin; Zhu, Guobin; Kaplan, David L; Cao, Chuanbao; Zhu, Hesun

    2015-01-01

    Hierarchical olive-like structured carbon-Fe3O4 nanocomposite particles composed of a hollow interior and a carbon coated surface are prepared by a facile, silk protein-assisted hydrothermal method. Silk nanofibers as templates and carbon precursors first regulate the formation of hollow Fe2O3 microspheres and then they are converted into carbon in a reduction process into Fe3O4. This process significantly simplifies the fabrication and carbon coating processes to form complex hollow structures. When tested as anode materials for lithium-ion batteries, these hollow carbon-coated particles exhibite high capacity (900 mAh g−1), excellent cycle stability (180 cycles) and rate performance due to their unique hierarchical hollow structure and carbon coating. PMID:25706314

  20. Electrochemical properties of bare nickel sulfide and nickel sulfide-carbon composites prepared by one-pot spray pyrolysis as anode materials for lithium secondary batteries

    NASA Astrophysics Data System (ADS)

    Son, Mun Yeong; Choi, Jeong Hoo; Kang, Yun Chan

    2014-04-01

    Spherical bare nickel sulfide and nickel sulfide-carbon composite powders are prepared by a one-step spray pyrolysis. Submicron bare nickel sulfide particles with a dense structure have mixed crystal phases of NiS, Ni7S6, and NixS6. The nickel sulfide-carbon composite powders prepared from a spray solution containing 0.1 M sucrose have a main crystal structure of Ni7S6 phase with small impurity peaks of NixS6 phase. A nickel oxide-carbon composite powder is first formed as an intermediate product in the front part of the reactor at 800 °C. Fast decomposition of thiourea at this high temperature results in the evolution of hydrogen sulfide gas, which then forms the nickel sulfide-carbon composite powders by direct sulfidation of nickel oxide under the reducing atmosphere. Nickel sulfide nanocrystals with a size of a few nanometers are uniformly distributed inside the spherical carbon matrix. The nickel sulfide-carbon composite powders prepared with 0.1 M sucrose have an excellent discharge capacity of 472 mA h g-1 at a high current density of 1000 mA g-1, even after 500 cycles, with the corresponding capacity retention measured after the first cycle being 86%.

  1. Optimization and Domestic Sourcing of Lithium Ion Battery Anode Materials

    SciTech Connect

    Wood, III, D. L.; Yoon, S.

    2012-10-25

    The purpose of this Cooperative Research and Development Agreement (CRADA) between ORNL and A123Systems, Inc. was to develop a low-temperature heat treatment process for natural graphite based anode materials for high-capacity and long-cycle-life lithium ion batteries. Three major problems currently plague state-of-the-art lithium ion battery anode materials. The first is the cost of the artificial graphite, which is heat-treated well in excess of 2000°C. Because of this high-temperature heat treatment, the anode active material significantly contributes to the cost of a lithium ion battery. The second problem is the limited specific capacity of state-of-the-art anodes based on artificial graphites, which is only about 200-350 mAh/g. This value needs to be increased to achieve high energy density when used with the low cell-voltage nanoparticle LiFePO4 cathode. Thirdly, the rate capability under cycling conditions of natural graphite based materials must be improved to match that of the nanoparticle LiFePO4. Natural graphite materials contain inherent crystallinity and lithium intercalation activity. They hold particular appeal, as they offer huge potential for industrial energy savings with the energy costs essentially subsidized by geological processes. Natural graphites have been heat-treated to a substantially lower temperature (as low as 1000-1500°C) and used as anode active materials to address the problems described above. Finally, corresponding graphitization and post-treatment processes were developed that are amenable to scaling to automotive quantities.

  2. Sulfur-tolerant anode materials: Annual report, September 1986-September 1987

    SciTech Connect

    Remick, R.J.; Osif, T,; Lawson, M.

    1987-09-01

    This report summarizes the results of the first year's technical effort performed on a program identifying and evaluating alternative anode materials for use in molten carbonate fuel cells (MCFC) operating with high levels of sulfur contaminants in the fuel. A literature survey was performed on materials for use in the MCFC and on materials exhibiting good electrical conductivity at high temperature. A list candidate materials having a reported electrical conductivity in excess of 0.1 (ohm-cm)/sup -1/ was compiled. 19 candidate materials were selected, and nine have been tested for electrical conductivity and for stability in the molten eletrolyte. To date, only cobalt metal has proved to be stable under all test conditions. Several water-gas shift catalysts were also evaluated for their catalytic activity and sulfur resistance under conditions prevailing in the MCFC anode. 19 refs., 24 figs., 21 tabs

  3. Anode Materials for Rechargeable Li-Ion Batteries

    SciTech Connect

    B. Fultz

    2001-01-12

    This is the annual progress report for the Grant DE-FG03-00ER15035. This research is on materials for anodes and cathodes in electrochemical cells. The work is a mix of electrochemical measurements and analysis of the materials by transmission electron microscopy and x-ray diffractometry. Our materials studies on electrode materials divide into electronic studies of the valence at and around Li atoms, and the crystal structures of these materials. We are addressing the basic questions of how these change with Li concentration, and what long-term changes take place during charge/discharge cycling of the materials.

  4. Carbon nanotube composite materials

    DOEpatents

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2015-03-24

    A material consisting essentially of a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes dissolved in a solvent. Un-functionalized carbon nanotube concentrations up to 30 wt % and hydroxylated carbon nanotube concentrations up to 40 wt % can be used with even small concentrations of each (less than 2 wt %) useful in producing enhanced conductivity properties of formed thin films.

  5. Electrochemical properties of tin oxide flake/reduced graphene oxide/carbon composite powders as anode materials for lithium-ion batteries.

    PubMed

    Lee, Su Min; Choi, Seung Ho; Kang, Yun Chan

    2014-11-10

    Hierarchically structured tin oxide/reduced graphene oxide (RGO)/carbon composite powders are prepared through a one-pot spray pyrolysis process. SnO nanoflakes of several hundred nanometers in diameter and a few nanometers in thickness are uniformly distributed over the micrometer-sized spherical powder particles. The initial discharge and charge capacities of the tin oxide/RGO/carbon composite powders at a current density of 1000 mA g(-1) are 1543 and 1060 mA h g(-1), respectively. The discharge capacity of the tin oxide/RGO/carbon composite powders after 175 cycles is 844 mA h g(-1), and the capacity retention measured from the second cycle is 80%. The transformation during cycling of SnO nanoflakes, uniformly dispersed in the tin oxide/RGO/carbon composite powder, into ultrafine nanocrystals results in hollow nanovoids that act as buffers for the large volume changes that occur during cycling, thereby improving the cycling and rate performances of the tin oxide/RGO/carbon composite powders. PMID:25266199

  6. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries

    NASA Astrophysics Data System (ADS)

    Campbell, Brennan; Ionescu, Robert; Favors, Zachary; Ozkan, Cengiz S.; Ozkan, Mihrimah

    2015-09-01

    Here we explore the electrochemical performance of pyrolyzed skins from the species A. bisporus, also known as the Portobello mushroom, as free-standing, binder-free, and current collector-free Li-ion battery anodes. At temperatures above 900 °C, the biomass-derived carbon nanoribbon-like architectures undergo unique processes to become hierarchically porous. During heat-treatment, the oxygen and heteroatom-rich organics and potassium compounds naturally present in the mushroom skins play a mutual role in creating inner void spaces throughout the resulting carbon nanoribbons, which is a process analogous to KOH-activation of carbon materials seen in literature. The pores formed in the pyrolytic carbon nanoribbons range in size from sub-nanometer to tens of nanometers, making the nanoribbons micro, meso, and macroporous. Detailed studies were conducted on the carbon nanoribbons using SEM and TEM to study morphology, as well as XRD and EDS to study composition. The self-supporting nanoribbon anodes demonstrate significant capacity increase as they undergo additional charge/discharge cycles. After a pyrolysis temperature of 1100 °C, the pristine anodes achieve over 260 mAh/g after 700 cycles and a Coulombic efficiency of 101.1%, without the use of harmful solvents or chemical activation agents.

  7. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries

    PubMed Central

    Campbell, Brennan; Ionescu, Robert; Favors, Zachary; Ozkan, Cengiz S.; Ozkan, Mihrimah

    2015-01-01

    Here we explore the electrochemical performance of pyrolyzed skins from the species A. bisporus, also known as the Portobello mushroom, as free-standing, binder-free, and current collector-free Li-ion battery anodes. At temperatures above 900 °C, the biomass-derived carbon nanoribbon-like architectures undergo unique processes to become hierarchically porous. During heat-treatment, the oxygen and heteroatom-rich organics and potassium compounds naturally present in the mushroom skins play a mutual role in creating inner void spaces throughout the resulting carbon nanoribbons, which is a process analogous to KOH-activation of carbon materials seen in literature. The pores formed in the pyrolytic carbon nanoribbons range in size from sub-nanometer to tens of nanometers, making the nanoribbons micro, meso, and macroporous. Detailed studies were conducted on the carbon nanoribbons using SEM and TEM to study morphology, as well as XRD and EDS to study composition. The self-supporting nanoribbon anodes demonstrate significant capacity increase as they undergo additional charge/discharge cycles. After a pyrolysis temperature of 1100 °C, the pristine anodes achieve over 260 mAh/g after 700 cycles and a Coulombic efficiency of 101.1%, without the use of harmful solvents or chemical activation agents. PMID:26415917

  8. Bio-Derived, Binderless, Hierarchically Porous Carbon Anodes for Li-ion Batteries.

    PubMed

    Campbell, Brennan; Ionescu, Robert; Favors, Zachary; Ozkan, Cengiz S; Ozkan, Mihrimah

    2015-01-01

    Here we explore the electrochemical performance of pyrolyzed skins from the species A. bisporus, also known as the Portobello mushroom, as free-standing, binder-free, and current collector-free Li-ion battery anodes. At temperatures above 900 °C, the biomass-derived carbon nanoribbon-like architectures undergo unique processes to become hierarchically porous. During heat-treatment, the oxygen and heteroatom-rich organics and potassium compounds naturally present in the mushroom skins play a mutual role in creating inner void spaces throughout the resulting carbon nanoribbons, which is a process analogous to KOH-activation of carbon materials seen in literature. The pores formed in the pyrolytic carbon nanoribbons range in size from sub-nanometer to tens of nanometers, making the nanoribbons micro, meso, and macroporous. Detailed studies were conducted on the carbon nanoribbons using SEM and TEM to study morphology, as well as XRD and EDS to study composition. The self-supporting nanoribbon anodes demonstrate significant capacity increase as they undergo additional charge/discharge cycles. After a pyrolysis temperature of 1100 °C, the pristine anodes achieve over 260 mAh/g after 700 cycles and a Coulombic efficiency of 101.1%, without the use of harmful solvents or chemical activation agents. PMID:26415917

  9. Carbon nanotube film anodes for flexible lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Yoon, Sora; Lee, Sehyun; Kim, Soyoung; Park, Kyung-Won; Cho, Daehwan; Jeong, Youngjin

    2015-04-01

    In this study, carbon nanotube (CNT) film anodes are prepared for use in flexible lithium ion batteries, and the electrochemical performance of the CNT film anodes is evaluated. The CNT films are synthesized via chemical vapor deposition and direct spinning. The films are heat-treated under a nitrogen atmosphere at a high temperature to study the effects of heat treatment on the battery performance. The electrodes made with the CNT films are characterized via charge-discharge test, cyclic voltammetry, and impedance measurement. The results indicate that batteries with films heat-treated under a nitrogen atmosphere show a higher capacity, which can be a result of their high crystalline perfection. The impedance analysis shows that a lower resistance at the interface can be obtained by using heat-treated films. The charge-discharge tests are carried out by adjusting the rate from C/2 to 10C, and when the rate slows from 10C to 1C, the capacity of the samples largely recovers. The nitrogen/heat-treated CNT film electrodes present a capacity that is twice as high, such as 2C, 5C, and 10C, than untreated CNT film electrodes. These results indicate that the carbon nanotube film anodes have high potential for use in portable and wearable computers due to their flexibility.

  10. A new anode material for oxygen evolution in molten oxide electrolysis.

    PubMed

    Allanore, Antoine; Yin, Lan; Sadoway, Donald R

    2013-05-16

    Molten oxide electrolysis (MOE) is an electrometallurgical technique that enables the direct production of metal in the liquid state from oxide feedstock, and compared with traditional methods of extractive metallurgy offers both a substantial simplification of the process and a significant reduction in energy consumption. MOE is also considered a promising route for mitigation of CO2 emissions in steelmaking, production of metals free of carbon, and generation of oxygen for extra-terrestrial exploration. Until now, MOE has been demonstrated using anode materials that are consumable (graphite for use with ferro-alloys and titanium) or unaffordable for terrestrial applications (iridium for use with iron). To enable metal production without process carbon, MOE requires an anode material that resists depletion while sustaining oxygen evolution. The challenges for iron production are threefold. First, the process temperature is in excess of 1,538 degrees Celsius (ref. 10). Second, under anodic polarization most metals inevitably corrode in such conditions. Third, iron oxide undergoes spontaneous reduction on contact with most refractory metals and even carbon. Here we show that anodes comprising chromium-based alloys exhibit limited consumption during iron extraction and oxygen evolution by MOE. The anode stability is due to the formation of an electronically conductive solid solution of chromium(iii) and aluminium oxides in the corundum structure. These findings make practicable larger-scale evaluation of MOE for the production of steel, and potentially provide a key material component enabling mitigation of greenhouse-gas emissions while producing metal of superior metallurgical quality. PMID:23657254

  11. Advanced hybrid supercapacitor based on a mesoporous niobium pentoxide/carbon as high-performance anode.

    PubMed

    Lim, Eunho; Kim, Haegyeom; Jo, Changshin; Chun, Jinyoung; Ku, Kyojin; Kim, Seongseop; Lee, Hyung Ik; Nam, In-Sik; Yoon, Songhun; Kang, Kisuk; Lee, Jinwoo

    2014-09-23

    Recently, hybrid supercapacitors (HSCs), which combine the use of battery and supercapacitor, have been extensively studied in order to satisfy increasing demands for large energy density and high power capability in energy-storage devices. For this purpose, the requirement for anode materials that provide enhanced charge storage sites (high capacity) and accommodate fast charge transport (high rate capability) has increased. Herein, therefore, a preparation of nanocomposite as anode material is presented and an advanced HSC using it is thoroughly analyzed. The HSC comprises a mesoporous Nb2O5/carbon (m-Nb2O5-C) nanocomposite anode synthesized by a simple one-pot method using a block copolymer assisted self-assembly and commercial activated carbon (MSP-20) cathode under organic electrolyte. The m-Nb2O5-C anode provides high specific capacity with outstanding rate performance and cyclability, mainly stemming from its enhanced pseudocapacitive behavior through introduction of a carbon-coated mesostructure within a voltage range from 3.0 to 1.1 V (vs Li/Li(+)). The HSC using the m-Nb2O5-C anode and MSP-20 cathode exhibits excellent energy and power densities (74 W h kg(-1) and 18,510 W kg(-1)), with advanced cycle life (capacity retention: ∼90% at 1000 mA g(-1) after 1000 cycles) within potential range from 1.0 to 3.5 V. In particular, we note that the highest power density (18,510 W kg(-1)) of HSC is achieved at 15 W h kg(-1), which is the highest level among similar HSC systems previously reported. With further study, the HSCs developed in this work could be a next-generation energy-storage device, bridging the performance gap between conventional batteries and supercapacitors. PMID:25137384

  12. Tailored Recovery of Carbons from Waste Tires for Enhanced Performance as Anodes in Lithium-ion Batteries

    SciTech Connect

    Naskar, Amit K; Bi,; Saha, Dipendu; Chi, Miaofang; Bridges, Craig A; Paranthaman, Mariappan Parans

    2014-01-01

    Morphologically tailored pyrolysis-recovered carbon black is utilized in lithium-ion batteries as a potential solution for adding value to waste tire-rubber-derived materials. Micronized tire rubber was digested in a hot oleum bath to yield a sulfonated rubber slurry that was then filtered, washed, and compressed into a solid cake. Carbon was recovered from the modified rubber cake by pyrolysis in a nitrogen atmosphere. The chemical pretreatment of rubber produced a carbon monolith with higher yield than that from the control (a fluffy tire-rubber-derived carbon black). The carbon monolith showed a very small volume fraction of pores of widths 3 4 nm, reduced specific surface area, and an ordered assembly of graphitic domains. Electrochemical studies on the recovered-carbon-based anode revealed an improved Li-ion battery performance with higher reversible capacity than that of commercial carbon materials. Anodes made with a sulfonated tire-rubber-derived carbon and a control tire-rubber-derived carbon, respectively, exhibited an initial coulombic efficiency of 80% and 45%, respectively. The reversible capacity of the cell with the sulfonated carbon as anode was 400 mAh/g after 100 cycles, with nearly 100% coulombic efficiency. Our success in producing higher performance carbon material from waste tire rubber for potential use in energy storage applications adds a new avenue to tire rubber recycling.

  13. Electro-oxidation of perfluorooctanoic acid by carbon nanotube sponge anode and the mechanism.

    PubMed

    Xue, An; Yuan, Zi-Wen; Sun, Yan; Cao, An-Yuan; Zhao, Hua-Zhang

    2015-12-01

    As an emerging persistent organic pollutant (POPs), perfluorooctanoic acid (PFOA) exists widely in natural environment. It is of particular significance to develop efficient techniques to remove low-concentration PFOA from the contaminated waters. In this work, we adopted a new material, carbon nanotube (CNT) sponge, as electrode to enhance electro-oxidation and achieve high removal efficiency of low-concentration (100μgL(-1)) PFOA from water. CNT sponge was pretreated by mixed acids to improve the surface morphology, hydrophilicity and the content of carbonyl groups on the surface. The highest removal efficiencies for low-concentration PFOA electrolyzed by acid-treated CNT sponge anode proved higher than 90%. The electro-oxidation mechanism of PFOA on CNT sponge anode was also discussed. PFOA is adsorbed on the CNT sponge rapidly increasing the concentration of PFOA on anode surface. When the potential on the anode is adjusted to more than 3.5V, the adsorbed PFOA undergoes electrochemically oxidation and hydrolysis to produce shorter-chain perfluorocarboxylic acids with less CF2 unit. The efficient electro-oxidation of PFOA by CNT sponge anode is due to the combined effect of adsorption and electrochemical oxidation. These findings provide an efficient method to remove actual concentration PFOA from water. PMID:26172515

  14. Tin nanoparticle-loaded porous carbon nanofiber composite anodes for high current lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Shen, Zhen; Hu, Yi; Chen, Yanli; Zhang, Xiangwu; Wang, Kehao; Chen, Renzhong

    2015-03-01

    Metallic Sn is a promising high-capacity anode material for use in lithium-ion batteries (LIBs), but its huge volume variation during lithium ion insertion/extraction typically results in poor cycling stability. To address this, we demonstrate the fabrication of Sn nanoparticle-loaded porous carbon nanofiber (Sn-PCNF) composites via the electrospinning of Sn(II) acetate/mineral oil/polyacrylonitrile precursors in N,N-dimethylformamide solvent and their subsequent carbonization at 700 °C under an argon atmosphere. This is shown to result in an even distribution of pores on the surface of the nanofibers, allowing the Sn-PCNF composite to be used directly as an anode in lithium-ion batteries without the need to add non-active materials such as polymer binders or electrical conductors. With a discharge capacity of around 774 mA h g-1 achieved at a high current of 0.8 A g-1 over 200 cycles, this material clearly has a high rate capability and excellent cyclic stability, and thanks to its unique structure and properties, is an excellent candidate for use as an anode material in high-current rechargeable lithium-ion batteries.

  15. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-03-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g-1 at a current density of 100 mA g-1 with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g-1, the Cu/CF-800 anode can still deliver a capacity of 300 mAh g-1. This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li+ active positions by Cu nanoinclusion.

  16. An operando surface enhanced Raman spectroscopy (SERS) study of carbon deposition on SOFC anodes.

    PubMed

    Li, Xiaxi; Liu, Mingfei; Lee, Jung-pil; Ding, Dong; Bottomley, Lawrence A; Park, Soojin; Liu, Meilin

    2015-09-01

    Thermally robust and chemically inert Ag@SiO2 nanoprobes are employed to provide the surface enhanced Raman scattering (SERS) effect for an in situ/operando study of the early stage of carbon deposition on nickel-based solid oxide fuel cell (SOFC) anodes. The enhanced sensitivity to carbon enables the detection of different stages of coking, offering insights into intrinsic coking tolerance of material surfaces. Application of a thin coating of gadolinium doped ceria (GDC) enhances the resistance to coking of nickel surfaces. The electrochemically active Ni-YSZ interface appears to be more active for hydrocarbon reforming, resulting in the accumulation of different hydrocarbon molecules, which can be readily removed upon the application of an anodic current. Operando SERS is a powerful tool for the mechanistic study of coking in SOFC systems. It is also applicable to the study of other catalytic and electrochemical processes in a wide range of conditions. PMID:25599129

  17. Use of carbon mesh anodes and the effect of different pretreatment methods on power production in microbial fuel cells.

    PubMed

    Wang, Xin; Cheng, Shaoan; Feng, Yujie; Merrill, Matthew D; Saito, Tomonori; Logan, Bruce E

    2009-09-01

    Flat electrodes are useful in microbial fuel cells (MFCs) as close electrode spacing improves power generation. Carbon cloth and carbon paper materials typically used in hydrogen fuel cells, however, are prohibitively expensive for use in MFCs. An inexpensive carbon mesh material was examined here as a substantially less expensive alternative to these materials for the anode in an MFC. Pretreatment of the carbon mesh was needed to ensure adequate MFC performance. Heating the carbon mesh in a muffle furnace (450 degrees C for 30 min) resulted in a maximum power density of 922 mW/m2 (46 W/m3) with this heat-treated anode, which was 3% more power than that produced using a mesh anode cleaned with acetone (893 mW/ m2; 45 W/m3). This power density with heating was only 7% less than that achieved with carbon cloth treated by a high temperature ammonia gas process (988 mW/m2; 49 W/m3). When the carbon mesh was treated by the ammonia gas process, power increased to 1015 mW/m2(51 W/m3). Analysis of the cleaned or heated surfaces showed these processes decreased atomic O/C ratio, indicating removal of contaminants that interfered with charge transfer. Ammonia gas treatment also increased the atomic N/C ratio, suggesting that this process produced nitrogen related functional groups that facilitated electron transfer. These results show that low cost heat-treated carbon mesh materials can be used as the anode in an MFC, providing good performance and even exceeding performance of carbon cloth anodes. PMID:19764262

  18. The effects of silicon doping on the performance of PMAN carbon anodes in Li-ion cells

    SciTech Connect

    Guidotti, R.A.; Johnson, B.J.; Even, W. Jr.

    1996-05-01

    Carbons derived from polymethylacrylonitrile (PMAN) have been studied for use as intercalation anodes in Li-ion cells. The effect of Si doping upon the electrochemical performance of PMAN carbons was studied using tetravinylsilane (TVS) and tetramethysilane (TMS) as sources of Si during the formation of the PMAN precursors. The carbons were characterized by galvanostatic cycling, cyclic voltammetry, and complex impedance. The presence of 9 to 11 w/o Si in the PMAN lattice greatly increased the irreversible capacity of these materials.

  19. Lignin Based Carbon Materials for Energy Storage Applications

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori; Rios, Orlando; Johs, Alexander

    2014-01-01

    The implementation of Li-ion battery technology into electric and hybrid electric vehicles and portable electronic devices such as smart phones, laptops and tablets, creates a demand for efficient, economic and sustainable materials for energy storage. However, the high cost and long processing time associated with manufacturing battery-grade anode and cathode materials are two big constraints for lowering the total cost of batteries and environmentally friendly electric vehicles. Lignin, a byproduct of the pulp and paper industry and biorefinery, is one of the most abundant and inexpensive natural biopolymers. It can be efficiently converted to low cost carbon fibers with optimal properties for use as anode materials. Recent developments in the preparation of lignin precursors and conversion to carbon fiber-based anode materials have created a new class of anode materials with excellent electrochemical characteristics suitable for immediate use in existing Li- or Na-ion battery technologies.

  20. Mesoporous carbon materials

    SciTech Connect

    Dai, Sheng; Wang, Xiqing

    2012-02-14

    The invention is directed to a method for fabricating a mesoporous carbon material, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic compound or material, (iii) a crosslinkable aldehyde component, and (iv) at least 0.5 M concentration of a strong acid having a pKa of or less than -2, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a mesoporous carbon material. The invention is also directed to a mesoporous carbon material having an improved thermal stability, preferably produced according to the above method.

  1. Mesoporous carbon materials

    DOEpatents

    Dai, Sheng; Wang, Xiqing

    2013-08-20

    The invention is directed to a method for fabricating a mesoporous carbon material, the method comprising subjecting a precursor composition to a curing step followed by a carbonization step, the precursor composition comprising: (i) a templating component comprised of a block copolymer, (ii) a phenolic compound or material, (iii) a crosslinkable aldehyde component, and (iv) at least 0.5 M concentration of a strong acid having a pKa of or less than -2, wherein said carbonization step comprises heating the precursor composition at a carbonizing temperature for sufficient time to convert the precursor composition to a mesoporous carbon material. The invention is also directed to a mesoporous carbon material having an improved thermal stability, preferably produced according to the above method.

  2. Modification of carbon nanotubes by CuO-doped NiO nanocomposite for use as an anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Mustansar Abbas, Syed; Tajammul Hussain, Syed; Ali, Saqib; Ahmad, Nisar; Ali, Nisar; Abbas, Saghir; Ali, Zulfiqar

    2013-06-01

    CuO-doped NiO (CuNiO) with porous hexagonal morphology is fabricated via a modified in-situ co-precipitation method and its nanocomposite is prepared with carbon nanotubes (CNTs). The electrochemical properties of CuNiO/CNT nanocomposite are investigated by cyclic voltammetry (CV), galvanostatic charge-discharge tests and electrochemical impedance spectroscopy (EIS). Since Cu can both act as conductor and a catalyst, the CuNiO/CNT nanocomposite exhibits higher initial coulombic efficiency (82.7% of the 2nd cycle) and better capacity retention (78.6% on 50th cycle) than bare CuNiO (78.9% of the 2nd cycle), CuO/CNT (76.8% of the 2nd cycle) and NiO/CNT (77.7% of the 2nd cycle) at the current density of 100 mA /g. This high capacity and good cycling ability is attributed to the partial substitution of Cu+2 for Ni+2, resulting in an increase of holes concentration, and therefore improved p-type conductivity along with an intimate interaction with CNTs providing large surface area, excellent conduction, mechanical strength and chemical stability.

  3. Metallic carbon materials

    DOEpatents

    Cohen, Marvin Lou; Crespi, Vincent Henry; Louie, Steven Gwon Sheng; Zettl, Alexander Karlwalter

    1999-01-01

    Novel metallic forms of planar carbon are described, as well as methods of designing and making them. Nonhexagonal arrangements of carbon are introduced into a graphite carbon network essentially without destroying the planar structure. Specifically a form of carbon comprising primarily pentagons and heptagons, and having a large density of states at the Fermi level is described. Other arrangements of pentagons and heptagons that include some hexagons, and structures incorporating squares and octagons are additionally disclosed. Reducing the bond angle symmetry associated with a hexagonal arrangement of carbons increases the likelihood that the carbon material will have a metallic electron structure.

  4. Carbon supported tin-based nanocomposites as anodes for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhou, Xiangyang; Zou, Youlan; Yang, Juan

    2013-02-01

    SnO2 (Sn)/C composites as anodes for Li-ion batteries were fabricated by a simple chemical process of hydrothermal synthesis and subsequent heat treatment. The as-prepared materials were characterized by various analytic techniques. Results show that heat treatment temperature has a strong influence on physical and electrochemical performance of these composites. In these composites, irregular SnO2 lamellas arranged like chrysanthemum were dispersed among the elastic carbon matrix for rapid access of lithium ions to the material bulk. SnO2/C anode heat-treated at a temperature of 600 °C exhibits a reversible capacity of 533.4 mAh/g after 50 cycles at the current density of 100 mA/g.

  5. Review on recent progress of nanostructured anode materials for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Goriparti, Subrahmanyam; Miele, Ermanno; De Angelis, Francesco; Di Fabrizio, Enzo; Proietti Zaccaria, Remo; Capiglia, Claudio

    2014-07-01

    This review highlights the recent research advances in active nanostructured anode materials for the next generation of Li-ion batteries (LIBs). In fact, in order to address both energy and power demands of secondary LIBs for future energy storage applications, it is required the development of innovative kinds of electrodes. Nanostructured materials based on carbon, metal/semiconductor, metal oxides and metal phosphides/nitrides/sulfides show a variety of admirable properties for LIBs applications such as high surface area, low diffusion distance, high electrical and ionic conductivity. Therefore, nanosized active materials are extremely promising for bridging the gap towards the realization of the next generation of LIBs with high reversible capacities, increased power capability, long cycling stability and free from safety concerns. In this review, anode materials are classified, depending on their electrochemical reaction with lithium, into three groups: intercalation/de-intercalation, alloy/de-alloy and conversion materials. Furthermore, the effect of nanoscale size and morphology on the electrochemical performance is presented. Synthesis of the nanostructures, lithium battery performance and electrode reaction mechanisms are also discussed. To conclude, the main aim of this review is to provide an organic outline of the wide range of recent research progresses and perspectives on nanosized active anode materials for future LIBs.

  6. Municipal sludge-derived carbon anode with nitrogen- and oxygen-containing functional groups for high-performance microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Ma, Xiaoxiao; Feng, Chunhua; Zhou, Weijia; Yu, Hui

    2016-03-01

    The demand for efficient and cost-effective anode materials in microbial fuel cells (MFCs) provides the impetus to use carbon derived from solid waste to support bacterial growth and proliferation. Here we show that the municipal sludge-derived carbon (SC) with a porous structure and abundant surface functional groups is effective in improving performance of MFCs. The SC is coated on the 3-D graphite felt (GF) surface by pyrrole electropolymerization in order to increase the surface cites that are interacted with bacteria, resulting in the formation of PPy/SC-modified GF anode. The scanning electron microscopy analysis indicates that the PPy/SC-modified GF can substantially increase anode surface area. The X-ray photoelectron spectroscopy (XPS) results suggest that the PPy/SC-modified GF anode possesses higher surface N/C ratio and higher relative contents of Odbnd C-NH2 and Odbnd C-O functional groups than other counterpart anodes. These characteristics are essential for increasing bacterial attachment to the anode surface, electron-transfer rate and thus anode performance and power performance. The maximum power density resulting from the PPy/SC-modified GF anode was 568.5 mW m-2 (13.6 W m-3) increased by 1.9, 2.7 and 3.5 times as compared to the PPy/AC-modified GF anode, the PPy alone-modified GF anode and the unmodified GF anode, respectively.

  7. Electrochemical performance of Si anode modified with carbonized gelatin binder

    NASA Astrophysics Data System (ADS)

    Jiang, Ying; Mu, Daobin; Chen, Shi; Wu, Borong; Cheng, Kailin; Li, Luyu; Wu, Feng

    2016-09-01

    Gelatin is alternatively adopted as the binder to modify Si anode coupling with its carbonization treatment. The binder can provide good bonding and uniform dispersion of the particles besides its environmental benignancy. Importantly, the carbonized binder containing nitrogen will be advantageous to the electrical conductivity of the electrode. In addition, some spaces are formed in the electrode due to the decomposition and shrinkage of the gelatin binder during heat-treatment, which may facilitate electrolyte penetration and accommodate volume change during cycling. All these merits make contribution to the good electrochemical performance of the modified Si electrode. It exhibits a reversible capacity of 990.3 mA h g-1 after 70 cycles at a current density of 100 mA g-1 and 904 mA h g-1 after 100 cycles at 400 mA g-1.

  8. Evaluation of Carbon Anodes for Rechargeable Lithium Cells

    NASA Technical Reports Server (NTRS)

    Huang, C-K.; Surampudi, S.; Attia, A.; Halpert, G.

    1993-01-01

    Both liquid phase intercalation technique and electrochemical intercalation technique were examined for the Li-carbon material preparation. The electrochemical techniques include a intermittent discharge method and a two step method. These two electrochemical techniques can ensure to achieve the maximum reversible Li capacity for common commercially available carbon materials. The carbon materials evaluated by the intercalacation method includes: pitch coke, petroleum cole, PAN fiber and graphite materials. Their reversible Li capacity were determined and compared. In this paper, we also demonstrate the importance of EPDM binder composition in the carbon electrode. Our results indicated that it can impact the Li intercalation and de-intercalation capacity in carbon materials. Finally, two possibilities that may help explain the capacity degradation during practical cell cycling were proposed.

  9. Sustainable carbon materials.

    PubMed

    Titirici, Maria-Magdalena; White, Robin J; Brun, Nicolas; Budarin, Vitaliy L; Su, Dang Sheng; del Monte, Francisco; Clark, James H; MacLachlan, Mark J

    2015-01-01

    Carbon-based structures are the most versatile materials used in the modern field of renewable energy (i.e., in both generation and storage) and environmental science (e.g., purification/remediation). However, there is a need and indeed a desire to develop increasingly more sustainable variants of classical carbon materials (e.g., activated carbons, carbon nanotubes, carbon aerogels, etc.), particularly when the whole life cycle is considered (i.e., from precursor "cradle" to "green" manufacturing and the product end-of-life "grave"). In this regard, and perhaps mimicking in some respects the natural carbon cycles/production, utilization of natural, abundant and more renewable precursors, coupled with simpler, lower energy synthetic processes which can contribute in part to the reduction in greenhouse gas emissions or the use of toxic elements, can be considered as crucial parameters in the development of sustainable materials manufacturing. Therefore, the synthesis and application of sustainable carbon materials are receiving increasing levels of interest, particularly as application benefits in the context of future energy/chemical industry are becoming recognized. This review will introduce to the reader the most recent and important progress regarding the production of sustainable carbon materials, whilst also highlighting their application in important environmental and energy related fields. PMID:25301517

  10. Carbon Encapsulated Tin Oxide Nanocomposites: An Efficient Anode for High Performance Sodium-Ion Batteries.

    PubMed

    Kalubarme, Ramchandra S; Lee, Jae-Young; Park, Chan-Jin

    2015-08-12

    The major obstacle in realizing sodium (Na)-ion batteries (NIBs) is the absence of suitable negative electrodes. This is because graphite, a commercially well known anode material for lithium-ion batteries, cannot be utilized as an insertion host for Na ions due to its large ionic size. In this study, a simple and cost-effective hydrothermal method to prepare carbon coated tin oxide (SnO2) nanostructures as an efficient anode material for NIBs was reported as a function of the solvent used. A single phase SnO2 resulted for the ethanol solvent, while a blend of SnO and SnO2 resulted for the DI water and ethylene glycol solvents. The elemental mapping in the transmission electron microscopy confirmed the presence of carbon coating on the SnO2 nanoparticles. In cell tests, the anodes of carbon coated SnO2 prepared in ethanol solvent exhibited stable cycling performance and attained a capacity of about 514 mAh g(-1) on the first charge. With the help of the conductive carbon coating, the SnO2 delivers more capacity at high rates: 304 mAh g(-1) at the 1 C rate, 213 mAh g(-1) at the 2 C rate and 133 mAh g(-1) at the 5 C rate. The excellent cyclability and high rate capability are the result of the formation of a mixed conducting network and uniform carbon coating on the SnO2 nanoparticles. PMID:26186401

  11. Carbon foam anode modified by urea and its higher electrochemical performance in marine benthic microbial fuel cell

    NASA Astrophysics Data System (ADS)

    Fu, Yubin; Lu, Zhikai; Zai, Xuerong; Wang, Jian

    2015-08-01

    Electrode materials have an important effect on the property of microbial fuel cell (MFC). Carbon foam is utilized as an anode and further modified by urea to improve its performance in marine benthic microbial fuel cell (BMFC) with higher voltage and output power. The electrochemical properties of plain carbon foam (PC) and urea-modified carbon foam (UC) are measured respectively. Results show that the UC obtains better wettability after its modification and higher anti-polarization ability than the PC. A novel phenomenon has been found that the electrical potential of the modified UC anode is nearly 100 mV lower than that of the PC, reaching -570 ±10 mV ( vs. SCE), and that it also has a much higher electron transfer kinetic activity, reaching 9399.4 mW m-2, which is 566.2-fold higher than that from plain graphite anode (PG). The fuel cell containing the UC anode has the maximum power density (256.0 mW m-2) among the three different BMFCs. Urea would enhance the bacteria biofilm formation with a more diverse microbial community and maintain more electrons, leading to a lower anodic redox potential and higher power output. The paper primarily analyzes why the electrical potential of the modified anode becomes much lower than that of others after urea modification. These results can be utilized to construct a novel BMFC with higher output power and to design the conditioner of voltage booster with a higher conversion ratio. Finally, the carbon foam with a bigger pore size would be a potential anodic material in conventional MFC.

  12. MoS2 coated hollow carbon spheres for anodes of lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zhang, Yufei; Wang, Ye; Yang, Jun; Shi, Wenhui; Yang, Huiying; Huang, Wei; Dong, Xiaochen

    2016-06-01

    With the assistance of resorcinol-formaldehyde, MoS2 coated hollow carbon spheres (C@MoS2) were synthesized through a facile hydrothermal route followed by heat and alkali treatments. The measurements indicate that the hollow carbon spheres with an average diameter of 300 nm and shell thickness of 20 nm. And the hollow core are uniformly covered by ultrathin MoS2 nanosheets with a length increased to 400 nm. The unique hollow structure and the synergistic effect between carbon layer and MoS2 nanosheets significantly enhance the rate capability and electrochemical stability of C@MoS2 spheres as anode material of lithium-ion battery. The synthesized C@MoS2 delivered a capacity of 750 mAh g-1 at a current density of 100 mA g-1. More importantly, the C@MoS2 maintained a reversible capacity of 533 mAh g-1 even at a high current density of 1000 mA g-1. The study indicated that MoS2 coated hollow carbon spheres can be promising anode material for next generation high-performance lithium-ion batteries.

  13. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, Stephen E.; Moses, William W.

    1991-01-01

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses.

  14. Anodic WO3 mesosponge @ carbon: a novel binder-less electrode for advanced energy storage devices.

    PubMed

    Pervez, Syed Atif; Kim, Doohun; Doh, Chil-Hoon; Farooq, Umer; Choi, Hae-Young; Choi, Jung-Hee

    2015-04-15

    A novel design for an anodic WO3 mesosponge @ carbon has been introduced as a highly stable and long cyclic life Li-ion battery electrode. The nanocomposite was successfully synthesized via single-step electrochemical anodization and subsequent heat treatment in an acetylene and argon gas environment. Morphological and compositional characterization of the resultant materials revealed that the composite consisted of a three-dimensional interconnected network of WO3 mesosponge layers conformally coated with a 5 nm thick carbon layer and grown directly on top of tungsten metal. The results demonstrated that the carbon-coated mesosponge WO3 layers exhibit a capacity retention of 87% after completion of 100 charge/discharge cycles, which is significantly higher than the values of 25% for the crystalline (without carbon coating) or 40% for the as-prepared mesosponge WO3 layers. The improved electrochemical response was attributed to the higher stability and enhanced electrical conductivity offered by the carbon coating layer. PMID:25794310

  15. A theoretical study of a carbon lattice system for lithium intercalated carbon anodes

    SciTech Connect

    Scanlon, L.G.; Storch, D.M.; Newton, J.H.; Sandi, G.

    1997-09-01

    A theoretical study was performed using computational chemistry to describe the intermolecular forces between graphite layers as well as spacing and conformation. It was found that electron correlation and a diffuse basis set were important for this calculation. In addition, the high reactivity of edge sites in lithium intercalated carbon anodes was also investigated. In this case, the reactive sites appear to strongly correlate with the relative distribution of the total atomic spin densities as well as total atomic charges. The spacing of graphite layers and lithium ion separation within an {open_quotes}approximated{close_quotes} lithium intercalated carbon anode was also investigated. The spacing of the carbon layers used in this investigation agrees most closely for that found in disordered carbon lattices.

  16. Revisiting Surface Modification of Graphite: Dual-Layer Coating for High-Performance Lithium Battery Anode Materials.

    PubMed

    Song, Gyujin; Ryu, Jaegeon; Ko, Seunghee; Bang, Byoung Man; Choi, Sinho; Shin, Myoungsoo; Lee, Sang-Young; Park, Soojin

    2016-06-01

    Surface modification of electrode active materials has garnered considerable attention as a facile way to meet stringent requirements of advanced lithium-ion batteries. Here, we demonstrated a new coating strategy based on dual layers comprising antimony-doped tin oxide (ATO) nanoparticles and carbon. The ATO nanoparticles are synthesized via a hydrothermal method and act as electronically conductive/electrochemically active materials. The as-synthesized ATO nanoparticles are introduced on natural graphite along with citric acid used as a carbon precursor. After carbonization, the carbon/ATO-decorated natural graphite (c/ATO-NG) is produced. In the (carbon/ATO) dual-layer coating, the ATO nanoparticles coupled with the carbon layer exhibit unprecedented synergistic effects. The resultant c/ATO-NG anode materials display significant improvements in capacity (530 mA h g(-1) ), cycling retention (capacity retention of 98.1 % after 50 cycles at a rate of C/5), and low electrode swelling (volume expansion of 38 % after 100 cycles) which outperform that of typical graphite materials. Furthermore, a full-cell consisting of a c/ATO-NG anode and an LiNi0.5 Mn1.5 O4 cathode presents excellent cycle retention (capacity retention of >80 % after 100 cycles). We envision that the dual-layer coating concept proposed herein opens a new route toward high-performance anode materials for lithium-ion batteries. PMID:27027583

  17. A Direct Carbon Fuel Cell with a Molten Antimony Anode

    SciTech Connect

    Jayakumar, Abhimanyu; Kungas, Rainer; Roy, Sounak; Javadekar, Ashay; Buttrey, Douglas J.; Vohs, John M.; Gorte, Raymond J.

    2011-01-01

    The direct utilization of carbonaceous fuels is examined in a solid oxide fuel cell (SOFC) with a molten Sb anode at 973 K. It is demonstrated that the anode operates by oxidation of metallic Sb at the electrolyte interface, with the resulting Sb₂O₃ being reduced by the fuel in a separate step. Although the Nernst Potential for the Sb-Sb₂O₃ mixture is only 0.75 V, the electrode resistance associated with molten Sb is very low, approximately 0.06 Ωcm², so that power densities greater than 350 mW cm⁻² were achieved with an electrolyte-supported cell made from Sc-stabilized zirconia (ScSZ). Temperature programmed reaction measurements of Sb₂O₃ with sugar char, rice starch, carbon black, and graphite showed that the Sb₂O₃ is readily reduced by a range of carbonaceous solids at typical SOFC operating conditions. Finally, stable operation with a power density of 300 mW cm⁻² at a potential of 0.5 V is demonstrated for operation on sugar char.

  18. Novel forms of carbon as potential anodes for lithium batteries

    SciTech Connect

    Winans, R.E.; Carrado, K.A.

    1994-06-01

    The objective of this study is to design and synthesize novel carbons as potential electrode materials for lithium rechargeable batteries. A synthetic approach which utilizes inorganic templates is described and initial characterization results are discussed. The templates also act as a catalyst enabling carbon formation at low temperatures. This synthetic approach should make it easier to control the surface and bulk characteristics of these carbons.

  19. Activated carbon material

    DOEpatents

    Evans, A. Gary

    1978-01-01

    Activated carbon particles for use as iodine trapping material are impregnated with a mixture of selected iodine and potassium compounds to improve the iodine retention properties of the carbon. The I/K ratio is maintained at less than about 1 and the pH is maintained at above about 8.0. The iodine retention of activated carbon previously treated with or coimpregnated with triethylenediamine can also be improved by this technique. Suitable flame retardants can be added to raise the ignition temperature of the carbon to acceptable standards.

  20. Low-surface-area hard carbon anode for Na-ion batteries via graphene oxide as a dehydration agent

    SciTech Connect

    Luo, Wei; Bommier, Clement; Jian, Zelang; Li, Xin; Carter, Rich; Vail, Sean; Lu, Yuhao; Lee, Jong -Jan; Ji, Xiulei

    2015-02-04

    Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m²/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burn-off of sucrose caramel over a wider temperature range. Thus, the obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.

  1. Low-Surface-Area Hard Carbon Anode for Na-Ion Batteries via Graphene Oxide as a Dehydration Agent

    SciTech Connect

    Luo, W; Bommier, C; Jian, ZL; Li, X; Carter, R; Vail, S; Lu, YH; Lee, JJ; Ji, XL

    2015-02-04

    Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m(2)/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burnoff of sucrose caramel over a wider temperature range. The obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.

  2. Low-surface-area hard carbon anode for na-ion batteries via graphene oxide as a dehydration agent.

    PubMed

    Luo, Wei; Bommier, Clement; Jian, Zelang; Li, Xin; Carter, Rich; Vail, Sean; Lu, Yuhao; Lee, Jong-Jan; Ji, Xiulei

    2015-02-01

    Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m(2)/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burnoff of sucrose caramel over a wider temperature range. The obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles. PMID:25562593

  3. Low-surface-area hard carbon anode for Na-ion batteries via graphene oxide as a dehydration agent

    DOE PAGESBeta

    Luo, Wei; Bommier, Clement; Jian, Zelang; Li, Xin; Carter, Rich; Vail, Sean; Lu, Yuhao; Lee, Jong -Jan; Ji, Xiulei

    2015-02-04

    Na-ion batteries are emerging as one of the most promising energy storage technologies, particularly for grid-level applications. Among anode candidate materials, hard carbon is very attractive due to its high capacity and low cost. However, hard carbon anodes often suffer a low first-cycle Coulombic efficiency and fast capacity fading. In this study, we discover that doping graphene oxide into sucrose, the precursor for hard carbon, can effectively reduce the specific surface area of hard carbon to as low as 5.4 m²/g. We further reveal that such doping can effectively prevent foaming during caramelization of sucrose and extend the pyrolysis burn-offmore » of sucrose caramel over a wider temperature range. Thus, the obtained low-surface-area hard carbon greatly improves the first-cycle Coulombic efficiency from 74% to 83% and delivers a very stable cyclic life with 95% of capacity retention after 200 cycles.« less

  4. Porous Si spheres encapsulated in carbon shells with enhanced anodic performance in lithium-ion batteries

    SciTech Connect

    Wang, Hui; Wu, Ping Shi, Huimin; Lou, Feijian; Tang, Yawen; Zhou, Tongge; Zhou, Yiming Lu, Tianhong

    2014-07-01

    Highlights: • In situ magnesiothermic reduction route for the formation of porous Si@C spheres. • Unique microstructural characteristics of both porous sphere and carbon matrix. • Enhanced anodic performance in term of cycling stability for lithium-ion batteries. - Abstract: A novel type of porous Si–C micro/nano-hybrids, i.e., porous Si spheres encapsulated in carbon shells (porous Si@C spheres), has been constructed through the pyrolysis of polyvinylidene fluoride (PVDF) and subsequent magnesiothermic reduction methodology by using SiO{sub 2} spheres as precursors. The as-synthesized porous Si@C spheres have been applied as anode materials for lithium-ion batteries (LIBs), and exhibit enhanced anodic performance in term of cycling stability compared with bare Si spheres. For example, the porous Si@C spheres are able to exhibit a high reversible capacity of 900.0 mA h g{sup −1} after 20 cycles at a current density of 0.05 C (1 C = 4200 mA g{sup −1}), which is much higher than that of bare Si spheres (430.7 mA h g{sup −1})

  5. Harvesting energy from the marine sediment-water interface. III. Kinetic activity of quinone- and antimony-based anode materials

    NASA Astrophysics Data System (ADS)

    Lowy, Daniel A.; Tender, Leonard M.

    Benthic microbial fuel cells (BMFCs) consist of an anode imbedded in marine sediment, connected by an external circuit to a cathode in overlying water. Long-term power density of BMFCs is limited by mass transport of the anode reactants, the transport being attributed to natural processes, including diffusion, convention, and tidal pumping. In order to increase short-term power density of BMFCs and long-term power density of a more recently reported BMFC, which artificially augments mass transport of the anode reactants, new anode materials are reported here with faster kinetics for microbial reduction as compared to commonly used G10 graphite. Results indicate that the kinetic activities (KAs) of glassy carbon graphite with surface-confined anthraquinone-1,6-disulfonic acid (AQDS), graphite paste with an incorporated Sb(V) complex, and oxidized graphite, and oxidized graphite subsequently modified with AQDS is 1.9-218 times greater than the KA of plain G10 graphite.

  6. Hollow silica-copper-carbon anodes using copper metal-organic frameworks as skeletons

    NASA Astrophysics Data System (ADS)

    Sun, Zixu; Xin, Fengxia; Cao, Can; Zhao, Chongchong; Shen, Cai; Han, Wei-Qiang

    2015-12-01

    Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and cushion the volume change. In consequence, the resulting material as an anode for lithium-ion batteries (LIBs) delivers a reversible capacity of 495 mA h g-1 after 400 cycles at a current density of 500 mA g-1. The synthetic method presented in this paper provides a facile and low-cost strategy for the large-scale production of hollow silica/copper/carbon nanocomposites as an anode in LIBs.Hollow silica-copper-carbon (H-SCC) nanocomposites are first synthesized using copper metal-organic frameworks as skeletons to form Cu-MOF@SiO2 and then subjected to heat treatment. In the composites, the hollow structure and the void space from the collapse of the MOF skeleton can accommodate the huge volume change, buffer the mechanical stress caused by lithium ion insertion/extraction and maintain the structural integrity of the electrode and a long cycling stability. The ultrafine copper with a uniform size of around 5 nm and carbon with homogeneous distribution from the decomposition of the MOF skeleton can not only enhance the electrical conductivity of the composite and preserve the structural and interfacial stabilization, but also suppress the aggregation of silica nanoparticles and

  7. Development of SOFC anodes resistant to sulfur poisoning and carbon deposition

    NASA Astrophysics Data System (ADS)

    Choi, Song Ho

    The advantages of solid oxide fuel cells (SOFCs) over other types of fuel cells include high energy efficiency and excellent fuel flexibility. In particular, the possibility of direct utilization of fossil fuels and renewable fuels (e.g., bio-fuels) may significantly reduce the cost of SOFC technologies. However, it is known that these types of fuels contain many contaminants that may be detrimental to SOFC performance. Among the contaminants commonly encountered in readily available fuels, sulfur-containing compounds could dramatically reduce the catalytic activity of Ni-based anodes under SOFC operating conditions. While various desulphurization processes have been developed for the removal of sulfur species to different levels, the process becomes another source of high cost and system complexity in order to achieve low concentration of sulfur species. Thus, the design of sulfur tolerant anode materials is essential to durability and commercialization of SOFCs. Another technical challenge to overcome for direct utilization of hydrocarbon fuels is carbon deposition. Carbon formation on Ni significantly degrades fuel cell performance by covering the electrochemically active sites at the anode. Therefore, the prevention of the carbon deposition is a key technical issue for the direct use of hydrocarbon fuels in a SOFC. In this research, the surface of a dense Ni-YSZ anode was modified with a thin-film coating of niobium oxide (Nb2O5) in order to understand the mechanism of sulfur tolerance and the behavior of carbon deposition. Results suggest that the niobium oxide was reduced to NbO 2 under operating conditions, which has high electrical conductivity. The NbOx coated dense Ni-YSZ showed sulfur tolerance when exposed to 50 ppm H2S at 700°C over 12 h. Raman spectroscopy and XRD analysis suggest that different phases of NbSx formed on the surface. Further, the DOS (density of state) analysis of NbO2, NbS, and NbS2 indicates that niobium sulfides can be considered

  8. Anodes for glucose fuel cells made of carbonized nanofibers with embedded carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Prilutsky, Sabina; Cohen, Yachin; Zussman, Eyal; Makarov, Vadim; Bubis, Eugenia; Schechner, Pinchas

    2010-03-01

    Electrodes made of carbonized polyacrylonitryle nanofibers, with and without embedded multiwall carbon nanotubes (MWCNT) were fabricated by the electrospinning (ES) process and evaluated as anodes in a glucose fuel cell (FC). The effect of several processing and structural characteristics, such as the presence of MWCNTs, polymer concentration in the ES solution and silver electroless plating, on FC performance were measured The carbon electrodes were successful as anodes showing significant activity even without additional silver catalyst, with noticeable improvement by incorporation of MWCNTs. The orientation of graphitic layers along the fiber axis and the coherence of layer packing were shown to be important for enhanced electrode activity. The maximal values of open circuit voltage (OCV) and peak of power density (PPD) of unmetallized electrodes, 0.4 V and 30 μW/cm^2, were found for composite carbon nanofiber electrode. Electroless silver metallization leads to enhanced performance. Maximal values of OCV and PPD of silvered electrodes were measured to be about 0.9 V and 400 μW/cm^2. Thus, carbonized nanofibers with embedded MWCNTs may form a good basis for glucose FC anodes, but better metallization and cell-configuration allowing proper mixing are required.

  9. Enhanced electrochemical performance and carbon anti-coking ability of solid oxide fuel cells with silver modified nickel-yttrium stabilized zirconia anode by electroless plating

    NASA Astrophysics Data System (ADS)

    Wu, Xiaoyan; Tian, Yu; Zhang, Jun; Zuo, Wei; Kong, Xiaowei; Wang, Jinghui; Sun, Kening; Zhou, Xiaoliang

    2016-01-01

    In this paper, silver (Ag) particles are introduced into the conventional Ni/YSZ anode by utilizing electroless plating method to improve its carbon anti-coking ability in hydrocarbons. The experimental results show that electrochemical performances of the decorated cells in H2, CH4 and C2H6 are all increased as compared to the cell with unmodified Ni/YSZ anode, which are verified by impedance spectrums as well. The durability experiment is carried out for as long as 24 h at the current density of 0.33 A/cm2 where the modified anode is subjected to dry C2H6 indicating the anti-coking ability of the anode is greatly improved. Scanning electron microscope shows that the slight decreasing in the cell terminal voltage can be attributed to the minimized carbon deposition which maybe resulted from the aggregation of silver particles at high temperature. Energy-dispersive X-ray spectroscopy line scanning results after long-term stability operation of the anode suggest that the carbon deposition can be depressed effectively both inside the anode and on the surface of the anode. Therefore, the results show that silver is a promising candidate material for modifying the Ni/YSZ anode with regard to improving electrochemical performance and suppressing the carbon deposition when taking the hydrocarbons as fuels.

  10. Reduction Mechanism of Fluoroethylene Carbonate for Stable Solid–Electrolyte Interphase Film on Silicon Anode

    SciTech Connect

    Chen, Xilin; Li, Xiaolin; Mei, Donghai; Feng, Ju; Hu, Mary Y.; Hu, Jian Z.; Engelhard, Mark H.; Zheng, Jianming; Xu, Wu; Xiao, Jie; Liu, Jun; Zhang, Jiguang

    2014-02-01

    Fluoroethylene Carbonate (FEC) is an effective electrolyte additive which can significantly improve the cyclability of Si and other anode materials. However, the fundamental mechanism on this improvement is still not well understood. Based on the results obtained from 6Li Nuclear Magnetic Resonance and X-ray Photoelectron Scanning study, we propose a molecular level mechanism on how FEC affects the formation of solid electrolyte interphase (SEI) film: 1) FEC is reduced through the opening of the five member ring leading to the formation of lithium poly (vinyl carbonate), LiF and some dimmers; 2) The high tensile strength of the FEC-derived lithium poly (vinyl carbonate) enhances the stability of the SEI film. This mechanism has been verified by the results of electrochemical tests.

  11. Hard Carbon Fibers Pyrolyzed from Wool as High-Performance Anode for Sodium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Zhu, Xiaoming; Li, Qian; Qiu, Shen; Liu, Xiaoling; Xiao, Lifen; Ai, Xinping; Yang, Hanxi; Cao, Yuliang

    2016-08-01

    In this paper, we first demonstrate that the wool from worn-out clothes can serve as a low-cost and easy-to-collect precursor to preparing high-performance hard carbons for Na-ion batteries. Morphological characterizations demonstrate that this wool-derived hard carbon presents well-defined and homogeneously dispersed fiber networks. X-ray diffraction results combined with high-resolution transmission electron microscopy analysis reveal that the interlayer space (d(002)) of the graphitic layers is 0.376 nm, sufficient for Na insertion into the stacked graphene layers. Electrochemical results show that the wool-derived hard carbon can deliver a high capacity of 303 mAh g-1 and excellent cycle stability over 80 cycles. This satisfactory electrochemical performance and easy synthetic procedure make it a promising anode material for practical SIBs.

  12. Graphene composites as anode materials in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Mazar Atabaki, M.; Kovacevic, R.

    2013-03-01

    Since the world of mobile phones and laptops has significantly altered by a big designer named Steve Jobs, the electronic industries have strived to prepare smaller, thinner and lower weight products. The giant electronic companies, therefore, compete in developing more efficient hardware such as batteries used inside the small metallic or polymeric frame. One of the most important materials in the production lines is the lithium-based batteries which is so famous for its ability in recharging as many times as a user needs. However, this is not an indication of being long lasted, as many of the electronic devices are frequently being used for a long time. The performance, chemistry, safety and above all cost of the lithium ion batteries should be considered when the design of the compounds are at the top concern of the engineers. To increase the efficiency of the batteries a combination of graphene and nanoparticles is recently introduced and it has shown to have enormous technological effect in enhancing the durability of the batteries. However, due to very high electronic conductivity, these materials can be thought of as preparing the anode electrode in the lithiumion battery. In this paper, the various approaches to characterize different types of graphene/nanoparticles and the process of preparing the anode for the lithium-ion batteries as well as their electrical properties are discussed.

  13. Copper Nanoparticle-Incorporated Carbon Fibers as Free-Standing Anodes for Lithium-Ion Batteries.

    PubMed

    Han, Pan; Yuan, Tao; Yao, Long; Han, Zhuo; Yang, Junhe; Zheng, Shiyou

    2016-12-01

    Copper-incorporated carbon fibers (Cu/CF) as free-standing anodes for lithium-ion batteries are prepared by electrospinning technique following with calcination at 600, 700, and 800 °C. The structural properties of materials are characterized by X-ray diffraction (XRD), Raman, thermogravimetry (TGA), scanning electron microscopy (SEM), transmission electron microscope (TEM), and energy dispersive X-ray spectrometry (EDS). It is found that the Cu/CF composites have smooth, regular, and long fibrous morphologies with Cu nanoparticles uniformly dispersed in the carbon fibers. As free-standing anodes, the unique structural Cu/CF composites show stable and high reversible capacities, together with remarkable rate and cycling capabilities in Li-ion batteries. The Cu/CF calcined at 800 °C (Cu/CF-800) has the highest charge/discharge capacities, long-term stable cycling performance, and excellent rate performance; for instance, the Cu/CF-800 anode shows reversible charge/discharge capacities of around 800 mAh g(-1) at a current density of 100 mA g(-1) with stable cycling performance for more than 250 cycles; even when the current density increases to 2 A g(-1), the Cu/CF-800 anode can still deliver a capacity of 300 mAh g(-1). This excellent electrochemical performance is attributed to the special 1D structure of Cu/CF composites, the enhanced electrical conductivity, and more Li(+) active positions by Cu nanoinclusion. PMID:27033848

  14. Lead carbonate scintillator materials

    DOEpatents

    Derenzo, S.E.; Moses, W.W.

    1991-05-14

    Improved radiation detectors containing lead carbonate or basic lead carbonate as the scintillator element are disclosed. Both of these scintillators have been found to provide a balance of good stopping power, high light yield and short decay constant that is superior to other known scintillator materials. The radiation detectors disclosed are favorably suited for use in general purpose detection and in medical uses. 3 figures.

  15. Effect of carbon on stress corrosion cracking and anodic oxidation of iron in NaOH solutions

    SciTech Connect

    Flis, J.; Ziomek-Moroz, Margaret

    2008-06-01

    Anodic behaviour of decarburised iron and of quenched Fe–C materials with up to 0.875 wt% C was examined in 8.5 M NaOH at 100 °C to explain the role of carbon in caustic stress corrosion cracking (SCC) of plain steels. Removal of carbon from Armco iron strongly reduced its intergranular SCC. Slip steps on grains did not initiate cracks. It has been shown that carbon at low contents deteriorates the passivation of iron, whereas at high contents it promotes the formation of magnetite. High resistance to SCC of high carbon steels can be explained by an intense formation of magnetite on these steels.

  16. Predicting capacity of hard carbon anodes in sodium-ion batteries using porosity measurements

    SciTech Connect

    Bommier, C; Luo, W; Gao, WY; Greaney, A; Ma, SQ; Ji, X

    2014-09-01

    We report an inverse relationship between measurable porosity values and reversible capacity from sucrose-derived hard carbon as an anode for sodium-ion batteries (SIBs). Materials with low measureable pore volumes and surface areas obtained through N-2 sorption yield higher reversible capacities. Conversely, increasing measurable porosity and specific surface area leads to sharp decreases in reversible capacity. Utilizing a low porosity material, we thus are able to obtain a reversible capacity of 335 mAh g(-1). These findings suggest that sodium-ion storage is highly dependent on the absence of pores detectable through N-2 sorption in sucrose-derived carbon. (C) 2014 Elsevier Ltd. All rights reserved.

  17. Development of high-energy silicon-based anode materials for lithium-ion storage

    NASA Astrophysics Data System (ADS)

    Yi, Ran

    The emerging markets of electric vehicles (EV) and hybrid electric vehicles (HEV) generate a tremendous demand for low-cost lithium-ion batteries (LIBs) with high energy and power densities, and long cycling life. The development of such LIBs requires development of low cost, high-energy-density cathode and anode materials. Conventional anode materials in commercial LIBs are primarily synthetic graphite-based materials with a capacity of ˜370 mAh/g. Improvements in anode performance, particularly in anode capacity, are essential to achieving high energy densities in LIBs for EV and HEV applications. This dissertation focuses on development of micro-sized silicon-carbon (Si-C) composites as anode materials for high energy and power densities LIBs. First, a new, low-cost, large-scale approach was developed to prepare a micro-sized Si-C composite with excellent performance as an anode material for LIBs. The composite shows a reversible capacity of 1459 mAh/g after 200 cycles at 1 A/g (97.8% capacity retention) and excellent high rate performance of 700 mAh/g at 12.8 A/g, and also has a high tap density of 0.78 g/cm3. The structure of the composite, micro-sized as a whole, features the interconnected nanoscale size of the Si building blocks and the uniform carbon filling, which enables the maximum utilization of silicon even when the micro-sized particles break into small pieces upon cycling. To understand the effects of key parameters in designing the micro-sized Si-C composites on their electrochemical performance and explore how to optimize them, the influence of Si nanoscale building block size and carbon coating on the electrochemical performance of the micro-sized Si-C composites were investigated. It has been found that the critical Si building block size is 15 nm, which enables a high capacity without compromising the cycling stability, and that carbon coating at higher temperature improves the 1st cycle coulombic efficiency (CE) and the rate capability

  18. Cerium oxide coated anodes for aluminum electrowinning: Topical report, October 1, 1986-June 30, 1987

    SciTech Connect

    Walker, J. K.

    1987-12-01

    Because of the cost of building and maintaining a carbon anode plant and the energy penalties associated with the use of carbon anodes in the production of aluminum, the use of inert anodes has long been proposed. Various cermet anodes have been investigated. In this paper, tests on a material, cerium oxyfluoride (CEROX), deposited in situ as an anode, are reported. (JDH)

  19. Material and Energy Flows in the Production of Cathode and Anode Materials for Lithium Ion Batteries

    SciTech Connect

    Dunn, Jennifer B.; James, Christine; Gaines, Linda; Gallagher, Kevin; Dai, Qiang; Kelly, Jarod C.

    2015-09-01

    The Greenhouse gases, Regulated Emissions and Energy use in Transportation (GREET) model has been expanded to include four new cathode materials that can be used in the analysis of battery-powered vehicles: lithium nickel cobalt manganese oxide (LiNi0.4Co0.2Mn0.4O2 [NMC]), lithium iron phosphate (LiFePO4 [LFP]), lithium cobalt oxide (LiCoO2 [LCO]), and an advanced lithium cathode (0.5Li2MnO3∙0.5LiNi0.44Co0.25Mn0.31O2 [LMR-NMC]). In GREET, these cathode materials are incorporated into batteries with graphite anodes. In the case of the LMR-NMC cathode, the anode is either graphite or a graphite-silicon blend. Lithium metal is also an emerging anode material. This report documents the material and energy flows of producing each of these cathode and anode materials from raw material extraction through the preparation stage. For some cathode materials, we considered solid state and hydrothermal preparation methods. Further, we used Argonne National Laboratory’s Battery Performance and Cost (BatPaC) model to determine battery composition (e.g., masses of cathode, anode, electrolyte, housing materials) when different cathode materials were used in the battery. Our analysis concluded that cobalt- and nickel-containing compounds are the most energy intensive to produce.

  20. Polyaniline-Coated Carbon Nanotube Ultrafiltration Membranes: Enhanced Anodic Stability for In Situ Cleaning and Electro-Oxidation Processes.

    PubMed

    Duan, Wenyan; Ronen, Avner; Walker, Sharon; Jassby, David

    2016-08-31

    Electrically conducting membranes (ECMs) have been reported to be efficient in fouling prevention and destruction of aqueous chemical compounds. In the current study, highly conductive and anodically stable composite polyaniline-carbon nanotube (PANI-CNT) ultrafiltration (UF) ECMs were fabricated through a process of electropolymerization of aniline on a CNT substrate under acidic conditions. The resulting PANI-CNT UF ECMs were characterized by scanning electron microscopy, atomic force microscopy, a four-point conductivity probe, cyclic voltammetry, and contact angle goniometry. The utilization of the PANI-CNT material led to significant advantages, including: (1) increased electrical conductivity by nearly an order of magnitude; (2) increased surface hydrophilicity while not impacting membrane selectivity or permeability; and (3) greatly improved stability under anodic conditions. The membrane's anodic stability was evaluated in a pH-controlled aqueous environment under a wide range of anodic potentials using a three-electrode cell. Results indicate a significantly reduced degradation rate in comparison to a CNT-poly(vinyl alcohol) ECM under high anodic potentials. Fouling experiments conducted with bovine serum albumin demonstrated the capacity of the PANI-CNT ECMs for in situ oxidative cleaning, with membrane flux restored to its initial value under an applied potential of 3 V. Additionally, a model organic compound (methylene blue) was electrochemically transformed at high efficiency (90%) in a single pass through the anodically charged ECM. PMID:27525344

  1. Tire-derived carbon composite anodes for sodium-ion batteries

    DOE PAGESBeta

    Li, Yunchao; Paranthaman, M. Parans; Akato, Kokouvi; Naskar, Amit K.; Levine, Alan M.; Lee, Richard J.; Kim, Sang-Ok; Zhang, Jinshui; Dai, Sheng; Manthiram, Arumugam

    2016-04-04

    We report that hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). The tire-derived carbons obtained by pyrolyzing the acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateaumore » is beneficial to enhance the energy density of the full cell. However, this plateau suffers rapid capacity fade at higher current densities. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.« less

  2. Tire-derived carbon composite anodes for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Li, Yunchao; Paranthaman, M. Parans; Akato, Kokouvi; Naskar, Amit K.; Levine, Alan M.; Lee, Richard J.; Kim, Sang-Ok; Zhang, Jinshui; Dai, Sheng; Manthiram, Arumugam

    2016-06-01

    Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). Tire-derived carbons obtained by pyrolyzing acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.

  3. Tire-derived Carbon Composite Anodes for Sodium-ion Batteries

    SciTech Connect

    Li, Yunchao; Paranthaman, M Parans; Naskar, Amit K; Levine, Alan M; Lee, Richard J; Kim, Sang Ok; Dai, Sheng; Manthiram, Arumugam

    2016-01-01

    Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). The tire-derived carbons obtained by pyrolyzing the acid-treated tire at 1100 C, 1400 C and 1600 C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. However, this plateau suffers rapid capacity fade at higher current densities. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.

  4. Tire-derived carbon composite anodes for sodium-ion batteries

    NASA Astrophysics Data System (ADS)

    Li, Yunchao; Paranthaman, M. Parans; Akato, Kokouvi; Naskar, Amit K.; Levine, Alan M.; Lee, Richard J.; Kim, Sang-Ok; Zhang, Jinshui; Dai, Sheng; Manthiram, Arumugam

    2016-06-01

    Hard-carbon materials are considered as one of the most promising anodes for the emerging sodium-ion batteries. Here, we report a low-cost, scalable waste tire-derived carbon as an anode for sodium-ion batteries (SIBs). Tire-derived carbons obtained by pyrolyzing acid-treated tire at 1100 °C, 1400 °C and 1600 °C show capacities of 179, 185 and 203 mAh g-1, respectively, after 100 cycles at a current density of 20 mA g-1 in sodium-ion batteries with good electrochemical stability. The portion of the low-voltage plateau region in the charge-discharge curves increases as the heat-treatment temperature increases. The low-voltage plateau is beneficial to enhance the energy density of the full cell. This study provides a new pathway for inexpensive, environmentally benign and value-added waste tire-derived products towards large-scale energy storage applications.

  5. Greater osteoblast functions on multiwalled carbon nanotubes grown from anodized nanotubular titanium for orthopedic applications

    NASA Astrophysics Data System (ADS)

    Sirivisoot, Sirinrath; Yao, Chang; Xiao, Xingcheng; Sheldon, Brian W.; Webster, Thomas J.

    2007-09-01

    Titanium (Ti) is the most widely implanted orthopedic material. However, current formulations of Ti have an average orthopedic implant functional lifetime of only 10-15 years. While there are many reasons why orthopedic implants fail, one is a lack of initial and sustained integration into juxtaposed bone. To improve the cytocompatibility properties of Ti for orthopedic applications, parallel multiwalled carbon nanotubes (CNTs) were grown from the pores of anodized nanotubular Ti by a chemical vapor deposition process in the present study. The results of this study provided evidence, for the first time, that osteoblast (bone forming cell) functions (specifically, alkaline phosphatase activity and calcium deposition) were significantly greater on CNTs grown from anodized Ti than on anodized Ti without CNTs and currently-used Ti in orthopedics for up to 21 days. In summary, this study showed that bone growth could possibly be enhanced on currently-used Ti implants with protruding CNTs and, thus, they should be further studied for orthopedic applications.

  6. A novel graphene-polysulfide anode material for high-performance lithium-ion batteries.

    PubMed

    Ai, Wei; Xie, Linghai; Du, Zhuzhu; Zeng, Zhiyuan; Liu, Juqing; Zhang, Hua; Huang, Yunhui; Huang, Wei; Yu, Ting

    2013-01-01

    We report a simple and efficient approach for fabrication of novel graphene-polysulfide (GPS) anode materials, which consists of conducting graphene network and homogeneously distributed polysulfide in between and chemically bonded with graphene sheets. Such unique architecture not only possesses fast electron transport channels, shortens the Li-ion diffusion length but also provides very efficient Li-ion reservoirs. As a consequence, the GPS materials exhibit an ultrahigh reversible capacity, excellent rate capability and superior long-term cycling performance in terms of 1600, 550, 380 mAh g(-1) after 500, 1300, 1900 cycles with a rate of 1, 5 and 10 A g(-1) respectively. This novel and simple strategy is believed to work broadly for other carbon-based materials. Additionally, the competitive cost and low environment impact may promise such materials and technique a promising future for the development of high-performance energy storage devices for diverse applications. PMID:23903017

  7. The effects of petroleum coke properties on carbon anode quality

    SciTech Connect

    Belitskus, D. ); Danka, D.J. )

    1988-11-01

    Comprehensive bench-scale testing of the effects of calcined coke on the properties of prebaked anodes for aluminum smelting cells has revealed correlations between coke and anode properties. Extensive measurements of the physical properties of coke as well as impurities, determinations of performance-indicative anode properties, and correlation by regression analyses provided statistically significant relationships which can generally be explained in terms of reasonable chemical and physical interactions.

  8. Modified natural graphite as anode material for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wu, Y. P.; Jiang, C.; Wan, C.; Holze, R.

    A concentrated nitric acid solution was used as an oxidant to modify the electrochemical performance of natural graphite as anode material for lithium ion batteries. Results of X-ray photoelectron spectroscopy, electron paramagnetic resonance, thermogravimmetry, differential thermal analysis, high resolution electron microscopy, and measurement of the reversible capacity suggest that the surface structure of natural graphite was changed, a fresh dense layer of oxides was formed. Some structural imperfections were removed, and the stability of the graphite structure increased. These changes impede decomposition of electrolyte solvent molecules, co-intercalation of solvated lithium ions and movement of graphene planes along the a-axis direction. Concomitantly, more micropores were introduced, and thus, lithium intercalation and deintercalation were favored and more sites were provided for lithium storage. Consequently, the reversible capacity and the cycling behavior of the modified natural graphite were much improved by the oxidation. Obviously, the liquid-solid oxidation is advantageous in controlling the uniformity of the products.

  9. Carbon Nanofibers Modified Graphite Felt for High Performance Anode in High Substrate Concentration Microbial Fuel Cells

    PubMed Central

    Shen, Youliang; Zhou, Yan; Chen, Shuiliang; Yang, Fangfang; Zheng, Suqi; Hou, Haoqing

    2014-01-01

    Carbon nanofibers modified graphite fibers (CNFs/GF) composite electrode was prepared for anode in high substrate concentration microbial fuel cells. Electrochemical tests showed that the CNFs/GF anode generated a peak current density of 2.42 mA cm−2 at a low acetate concentration of 20 mM, which was 54% higher than that from bare GF. Increase of the acetate concentration to 80 mM, in which the peak current density of the CNFs/GF anode greatly increased and was up to 3.57 mA cm−2, was seven times as that of GF anode. Morphology characterization revealed that the biofilms in the CNFs/GF anode were much denser than those in the bare GF. This result revealed that the nanostructure in the anode not only enhanced current generation but also could tolerate high substrate concentration. PMID:24883348

  10. [Hardened anodized aluminum as a replacement material for bracket manufacture].

    PubMed

    Fischer-Brandies, H; Bönhoff, M

    1994-12-01

    Attention has been repeatedly drawn to the problem of corrosion and the risk of allergic reaction to nickel resulting from the use of stainless steel brackets. In the search for a suitable alternative, manufacturers have turned to thin coating technology using hardened anodized aluminium. Applying resistance to corrosion and abrasion as the criteria to be met, they have selected aluminium alloy type 6082 as the material of choice. Purpose of this study is to examine the physical suitability of this material. Using the above noted alloy, 60 prototype brackets were made with a hardened anodized surface. They were then subjected to the following 3 stress tests: first an abrasion test using a tooth polishing machine, second, a deformation test using a device designed to simulate torque movement, and, third, a corrosion test. The effects on the brackets resulting from the three types of stress were evaluated by light microscopy. A quantitative analysis of the corrosion test was performed by ICP spectrometry. The control group consisted of conventional stainless steel brackets. The light microscopic analysis revealed no evidence of surface damage or signs of deformation in the prototype brackets. The steel brackets, on the other hand, showed clear signs of wear and corrosion. The quantitative analysis of the corrosion solution revealed metallic ion wear of 1.75 ng x mm-2 x h-1 for the prototypes subjected to abrasion. The steel brackets showed at a factor of around 104.6 metallic ion wear of 183 ng x mm-2 x h-1. In addition to this, no Ni ions were found in the corrosion solution of the prototype brackets.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7851828

  11. Formation of stable phosphorus-carbon bond for enhanced performance in black phosphorus nanoparticle-graphite composite battery anodes.

    PubMed

    Sun, Jie; Zheng, Guangyuan; Lee, Hyun-Wook; Liu, Nian; Wang, Haotian; Yao, Hongbin; Yang, Wensheng; Cui, Yi

    2014-08-13

    High specific capacity battery electrode materials have attracted great research attention. Phosphorus as a low-cost abundant material has a high theoretical specific capacity of 2596 mAh/g with most of its capacity at the discharge potential range of 0.4-1.2 V, suitable as anodes. Although numerous research progress have shown other high capacity anodes such as Si, Ge, Sn, and SnO2, there are only a few studies on phosphorus anodes despite its high theoretical capacity. Successful applications of phosphorus anodes have been impeded by rapid capacity fading, mainly caused by large volume change (around 300%) upon lithiation and thus loss of electrical contact. Using the conducting allotrope of phosphorus, "black phosphorus" as starting materials, here we fabricated composites of black phosphorus nanoparticle-graphite by mechanochemical reaction in a high energy mechanical milling process. This process produces phosphorus-carbon bonds, which are stable during lithium insertion/extraction, maintaining excellent electrical connection between phosphorus and carbon. We demonstrated high initial discharge capacity of 2786 mAh·g(-1) at 0.2 C and an excellent cycle life of 100 cycles with 80% capacity retention. High specific discharge capacities are maintained at fast C rates (2270, 1750, 1500, and 1240 mAh·g(-1) at C/5, 1, 2, and 4.5 C, respectively). PMID:25019417

  12. Electron beam modification of anode materials for high-rate lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Park, Yiseul; Park, Jung Soo; Baek, Seong-Ho; Kim, Jae Hyun

    2015-11-01

    The rate capability of a Li4Ti5O12 (LTO)-based anode in a lithium ion battery can be easily improved by electron beam (EB) irradiation without the need for complicated synthetic procedures. The electrode prepared with EB-irradiated LTO at a 50 kGy dose has an enhanced rate capability while retaining a discharge capacity of 100 mAh g-1, even at the 20 C-rate. The effect of EB irradiation on the properties of the anode materials (i.e., LTO, poly(vinylidene fluoride) (PVDF), super P carbon) is examined in detail through systematic experiments. Both LTO and PVDF are affected by EB irradiation and dependent on the exposed electron dose, but super P is affected negligibly. EB irradiation partially reduces LTO with forming Tix+ (2 < x < 4) which is attributed to the enhanced electrical conductivity. EB irradiation causes dehydrofluorination and cross-linking in PVDF, resulting in the formation of carbon-carbon double bonds. The conjugated structure of PVDF is formed by the further dehydrofluorination during mixing with LTO via ball-milling, and this is accelerated in the presence of EB-PVDF. This conjugated structure enhances the electrical conductivity and is responsible for the improved rate capability.

  13. Monodisperse Porous Silicon Spheres as Anode Materials for Lithium Ion Batteries

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Favors, Zachary; Ionescu, Robert; Ye, Rachel; Bay, Hamed Hosseini; Ozkan, Mihrimah; Ozkan, Cengiz S.

    2015-03-01

    Highly monodisperse porous silicon nanospheres (MPSSs) are synthesized via a simple and scalable hydrolysis process with subsequent surface-protected magnesiothermic reduction. The spherical nature of the MPSSs allows for a homogenous stress-strain distribution within the structure during lithiation and delithiation, which dramatically improves the electrochemical stability. To fully extract the real performance of the MPSSs, carbon nanotubes (CNTs) were added to enhance the electronic conductivity within the composite electrode structure, which has been verified to be an effective way to improve the rate and cycling performance of anodes based on nano-Si. The Li-ion battery (LIB) anodes based on MPSSs demonstrate a high reversible capacity of 3105 mAh g-1. In particular, reversible Li storage capacities above 1500 mAh g-1 were maintained after 500 cycles at a high rate of C/2. We believe this innovative approach for synthesizing porous Si-based LIB anode materials by using surface-protected magnesiothermic reduction can be readily applied to other types of SiOx nano/microstructures.

  14. Monodisperse porous silicon spheres as anode materials for lithium ion batteries.

    PubMed

    Wang, Wei; Favors, Zachary; Ionescu, Robert; Ye, Rachel; Bay, Hamed Hosseini; Ozkan, Mihrimah; Ozkan, Cengiz S

    2015-01-01

    Highly monodisperse porous silicon nanospheres (MPSSs) are synthesized via a simple and scalable hydrolysis process with subsequent surface-protected magnesiothermic reduction. The spherical nature of the MPSSs allows for a homogenous stress-strain distribution within the structure during lithiation and delithiation, which dramatically improves the electrochemical stability. To fully extract the real performance of the MPSSs, carbon nanotubes (CNTs) were added to enhance the electronic conductivity within the composite electrode structure, which has been verified to be an effective way to improve the rate and cycling performance of anodes based on nano-Si. The Li-ion battery (LIB) anodes based on MPSSs demonstrate a high reversible capacity of 3105 mAh g(-1). In particular, reversible Li storage capacities above 1500 mAh g(-1) were maintained after 500 cycles at a high rate of C/2. We believe this innovative approach for synthesizing porous Si-based LIB anode materials by using surface-protected magnesiothermic reduction can be readily applied to other types of SiOx nano/microstructures. PMID:25740298

  15. Monodisperse Porous Silicon Spheres as Anode Materials for Lithium Ion Batteries

    PubMed Central

    Wang, Wei; Favors, Zachary; Ionescu, Robert; Ye, Rachel; Bay, Hamed Hosseini; Ozkan, Mihrimah; Ozkan, Cengiz S.

    2015-01-01

    Highly monodisperse porous silicon nanospheres (MPSSs) are synthesized via a simple and scalable hydrolysis process with subsequent surface-protected magnesiothermic reduction. The spherical nature of the MPSSs allows for a homogenous stress-strain distribution within the structure during lithiation and delithiation, which dramatically improves the electrochemical stability. To fully extract the real performance of the MPSSs, carbon nanotubes (CNTs) were added to enhance the electronic conductivity within the composite electrode structure, which has been verified to be an effective way to improve the rate and cycling performance of anodes based on nano-Si. The Li-ion battery (LIB) anodes based on MPSSs demonstrate a high reversible capacity of 3105 mAh g−1. In particular, reversible Li storage capacities above 1500 mAh g−1 were maintained after 500 cycles at a high rate of C/2. We believe this innovative approach for synthesizing porous Si-based LIB anode materials by using surface-protected magnesiothermic reduction can be readily applied to other types of SiOx nano/microstructures. PMID:25740298

  16. Graphitic carbon anode temperature excursions reflect crystallographic phase transitions in lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Srinivasan, Rengaswamy; Srinivasan, Lakshminarayan

    2015-10-01

    Surface temperature measurement of lithium-ion cells provides a limited view of internal physical processes during charging. Using a recently developed non-invasive battery internal temperature sensor, we now demonstrate that anode temperature reflects physically-based dynamics at the anode that were previously obscured by cell-surface measurements. First, using automated segmentation with a maximum-likelihood piecewise-linear statistical model, we show that features in the anode temperature reproducibly coincide with phase transitions into Stages IVd, IV and I of graphitic carbon lithiation at various charging rates. Second, we show that anode temperature peaks around 61% state of charge, intermediate between Stages II and I of the lithiated graphitic carbon. Third, we demonstrate a sharp and sustained increase in anode temperature at variable state of charge above 85%. These findings open the possibility for improved state-of-charge estimation and adaptive charging profiles that safely reduce charging time.

  17. Analysis of Cadmium in Undissolved Anode Materials of Mark-IV Electrorefiner

    SciTech Connect

    Tae-Sic Yoo; Guy L. Fredrickson; DeeEarl Vaden; Brian R. Westphal

    2013-10-01

    The Mark-IV electrorefiner (Mk-IV ER) contains an electrolyte/molten cadmium system for refining uranium electrochemically. Typically, the anode of the Mk-IV ER consists of the chopped sodium-bonded metallic driver fuels, which have been primarily U-10Zr binary fuels. Chemical analysis of the residual anode materials after electrorefining indicates that a small amount of cadmium is removed from the Mk-IV ER along with the undissolved anode materials. Investigation of chemical analysis data indicates that the amount of cadmium in the undissolved anode materials is strongly correlated with the anode rotation speeds and the residence time of the anode in the Mk-IV ER. Discussions are given to explain the prescribed correlation.

  18. Analysis of cadmium in undissolved anode materials of Mark-IV electro-refiner

    SciTech Connect

    Yoo, Tae-Sic; Fredrickson, G.L.; Vaden, D.; Westphal, B.

    2013-07-01

    The Mark-IV electro-refiner (Mk-IV ER) is a unit process in the FCF (Fuel Conditioning Facility), which is primarily assigned to treating the used driver fuels. Mk-IV ER contains an electrolyte/molten cadmium system for refining uranium electrochemically. Typically, the anode of the Mk-IV ER consists of the chopped sodium-bonded metallic driver fuels, which have been primarily U-10Zr binary fuels. Chemical analysis of the residual anode materials after electrorefining indicates that a small amount of cadmium is removed from the Mk-IV ER along with the undissolved anode materials. Investigation of chemical analysis data indicates that the amount of cadmium in the undissolved anode materials is strongly correlated with the anode rotation speeds and the residence time of the anode in the Mk-IV ER. Discussions are given to explain the prescribed correlation. (authors)

  19. Composite anodes for improved performance of a direct carbon fuel cell

    NASA Astrophysics Data System (ADS)

    Giddey, S.; Kulkarni, A.; Munnings, C.; Badwal, S. P. S.

    2015-06-01

    Direct carbon fuel cell (DCFC) technology has the potential to double the electric efficiency and halve the CO2 emissions compared with conventional coal fired power plants. The anode performance, long term stability and cell scalability, in addition to fuel feed mechanism, are the major issues for the development of this technology. In this study, lanthanum strontium cobalt ferrite (LSCF) - silver composite anode was evaluated in a scalable version of the DCFC tubular cell in a bed of carbon powder. Ag was added to increase lateral conductivity of the anode and reduce ohmic losses. The cell was operated for 100 h during which it was twice thermally cycled. The performance degradation was studied by employing electrochemical and structural characterisation techniques. The composite anode, in comparison to LSCF anode, produced a 60% improvement in the power density. The sources of performance degradation of the cell were found to be the partial decomposition of the perovskite phase and anode microstructure changes as revealed by XRD and SEM analysis in addition to the loss of carbon contact to the anode resulting from the continuous carbon consumption in the cell.

  20. Lithium-Ion-Battery Anode Materials with Improved Capacity from a Metal-Organic Framework.

    PubMed

    Lin, Xiao-Ming; Niu, Ji-Liang; Lin, Jia; Wei, Lei-Ming; Hu, Lei; Zhang, Gang; Cai, Yue-Peng

    2016-09-01

    We present a porous metal-organic framework (MOF) with remarkable thermal stability that exhibits a discharge capacity of 300 mAh g(-1) as an anode material for a lithium-ion battery. Pyrolysis of the obtained MOF gives an anode material with improved capacity (741 mAh g(-1)) and superior cyclic stability. PMID:27548622

  1. Carbon-coated silicon nanotube arrays on carbon cloth as a hybrid anode for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Gu, Lin; Qian, Haolei; Zhao, Ming; Ding, Xi; Peng, Xinsheng; Sha, Jian; Wang, Yewu

    2016-03-01

    Silicon hollow nanostructure has been considered as one of the most promising material for commercial application in lithium-ion batteries due to its significant improvement of cycling stability. The fabricated hybrid structures, carbon-coated silicon nanotube arrays on carbon cloth substrate, with a high surface area and short electron collection pathway have been directly used as anode electrodes without any additional binder. The electrodes exhibit high capacity, excellent rate capability and good cycling stability. The discharge capacity of the hybrid electrode (the deposition time of silicon shell: 5 min) keeps stable, and after 100 cycles, the discharge capacities still remain 3654 mAh g-1 at the rate of 0.5 C.

  2. Li-ion capacitors with carbon cathode and hard carbon/stabilized lithium metal powder anode electrodes

    NASA Astrophysics Data System (ADS)

    Cao, W. J.; Zheng, J. P.

    2012-09-01

    A lithium-ion capacitor was developed using a mixture of stabilized lithium metal powder and hard carbon as the anode electrode, while activated carbon was used as the cathode. A specific energy of approximately 82 Wh kg-1 was obtained based on the weight of electrode materials; however, when the electrolyte, separator, and current collectors were included, the specific energy of an assembled Li-ion capacitor was about 25 Wh kg-1. The capacitor was able to deliver over 60% of the maximum energy at a discharge C-rate of 44C. Through continuous galvanostatic charge/discharge cycling, the capacitance of the Li-ion capacitor degraded less than 3% over 600 cycles.

  3. Improving microstructure of silicon/carbon nanofiber composites as a Li battery anode

    SciTech Connect

    Howe, Jane Y; Meyer III, Harry M; Burton, David J.; Qi, Dr. Yue; Nazri, Maryam; Nazri, G. Abbas; Palmer, Andrew C.; Lake, Patrick D.

    2013-01-01

    We report the interfacial study of a silicon/carbon nanofiber (Si/CNF) nanocomposite material as a potentially high performance anode for rechargeable lithium ion batteries. The carbon nanofiber is hollow, with a graphitic interior and turbostratic exterior. Amorphous silicon layers were uniformly coated via chemical vapor deposition on both the exterior and interior surfaces of the CNF. The resulting Si/CNF composites were tested as anodes for Li ion batteries and exhibited capacities near 800 mAh g1 for 100 cycles. After cycling, we found that more Si had fallen off from the outer wall than from the innerwall of CNF. Theoretical calculations confirmed that this is due to a higher interfacial strength at the Si/Cedge interface at the inner wall than that of the Si/C-basal interface at the outer wall. Based upon the experimental analysis and theoretical calculation, we have proposed several interfacial engineering approaches to improve the performance of the electrodes by optimizing the microstructure of this nanocomposite.

  4. Hierarchical Graphene-Containing Carbon Nanofibers for Lithium-Ion Battery Anodes.

    PubMed

    Dufficy, Martin K; Khan, Saad A; Fedkiw, Peter S

    2016-01-20

    We present a method to produce composite anodes consisting of thermally reduced graphene oxide-containing carbon nanofibers (TRGO/CNFs) via electrospinning a dispersion of polyacrylonitrile (PAN) and graphene oxide (GO) sheets in dimethylformamide followed by heat treatment at 650 °C. A range of GO (1-20 wt % GO relative to polymer concentration) was added to the polymer solution, with each sample comprising similar polymer chain packing and subsequent CNF microstructure, as assessed by X-ray diffraction. An increase from 0 to 20 wt % GO in the fibers led to carbonized nonwovens with enhanced electronic conductivity, as TRGO sheets conductively connected the CNFs. Galvanostatic half-cell cycling revealed that TRGO addition enhanced the specific discharge capacity of the fibers. The optimal GO concentration of 5 wt % GO enhanced first-cycle discharge capacities at C/24 rates (15.6 mA g(-1)) 150% compared to CNFs, with a 400% capacity increase at 2-C rates (750 mA g(-1)). We attribute the capacity enhancement to a high degree of GO exfoliation. The TRGO/CNFs also experienced no capacity fade after 200 cycles at 2-C rates. Impedance spectroscopy of the composite anodes demonstrated that charge-transfer resistances decreased as GO content increased, implying that high GO loadings result in more electrochemically active material. PMID:26704705

  5. Improving Microstructure of Silicon/Carbon Nanofiber Composites as A Li Battery Anode

    SciTech Connect

    Howe, Jane Y; Burton, David J.; Meyer III, Harry M; Nazri, Maryam; Nazri, G. Abbas; Palmer, Andrew C.; Lake, Patrick D.

    2013-01-01

    We report the interfacial study of a silicon/carbon nanofiber (Si/CNF) nanocomposite material as a potentially high performance anode for rechargeable lithium ion batteries. The carbon nanofiber is hollow, with a graphitic interior and turbostratic exterior. Amorphous silicon layers were uniformly coated via chemical vapor deposition on both the exterior and interior surfaces of the CNF. The resulting Si/CNF composites were tested as anodes for Li ion batteries and exhibited capacities near 800 mAh g{sup -1} for 100 cycles. After cycling, we found that more Si had fallen off from the outer wall than from the inner wall of CNF. Theoretical calculations confirmed that this is due to a higher interfacial strength at the Si/C-edge interface at the inner wall than that of the Si/C-basal interface at the outer wall. Based upon the experimental analysis and theoretical calculation, we have proposed several interfacial engineering approaches to improve the performance of the electrodes by optimizing the microstructure of this nanocomposite.

  6. Light-weight free-standing carbon nanotube-silicon films for anodes of lithium ion batteries.

    PubMed

    Cui, Li-Feng; Hu, Liangbing; Choi, Jang Wook; Cui, Yi

    2010-07-27

    Silicon is an attractive alloy-type anode material because of its highest known capacity (4200 mAh/g). However, lithium insertion into and extraction from silicon are accompanied by a huge volume change, up to 300%, which induces a strong strain on silicon and causes pulverization and rapid capacity fading due to the loss of the electrical contact between part of silicon and current collector. Si nanostructures such as nanowires, which are chemically and electrically bonded to the current collector, can overcome the pulverization problem, however, the heavy metal current collectors in these systems are larger in weight than Si active material. Herein we report a novel anode structure free of heavy metal current collectors by integrating a flexible, conductive carbon nanotube (CNT) network into a Si anode. The composite film is free-standing and has a structure similar to the steel bar reinforced concrete, where the infiltrated CNT network functions as both mechanical support and electrical conductor and Si as a high capacity anode material for Li-ion battery. Such free-standing film has a low sheet resistance of approximately 30 Ohm/sq. It shows a high specific charge storage capacity (approximately 2000 mAh/g) and a good cycling life, superior to pure sputtered-on silicon films with similar thicknesses. Scanning electron micrographs show that Si is still connected by the CNT network even when small breaking or cracks appear in the film after cycling. The film can also "ripple up" to release the strain of a large volume change during lithium intercalation. The conductive composite film can function as both anode active material and current collector. It offers approximately 10 times improvement in specific capacity compared with widely used graphite/copper anode sheets. PMID:20518567

  7. Nitrogen doped carbon nanoparticles enhanced extracellular electron transfer for high-performance microbial fuel cells anode.

    PubMed

    Yu, Yang-Yang; Guo, Chun Xian; Yong, Yang-Chun; Li, Chang Ming; Song, Hao

    2015-12-01

    Nitrogen doped carbon nanoparticles (NDCN) were applied to modify the carbon cloth anodes of microbial fuel cells (MFCs) inoculated with Shewanella oneidensis MR-1, one of the most well-studied exoelectrogens. Experimental results demonstrated that the use of NDCN increased anodic absorption of flavins (i.e., the soluble electron mediator secreted by S. oneidensis MR-1), facilitating shuttle-mediated extracellular electron transfer. In addition, we also found that NDCN enabled enhanced contact-based direct electron transfer via outer-membrane c-type cytochromes. Taken together, the performance of MFCs with the NDCN-modified anode was enormously enhanced, delivering a maximum power density 3.5 times' higher than that of the MFCs without the modification of carbon cloth anodes. PMID:25439129

  8. Hydrogenotrophic denitrification process efficiency and the number of denitrifying bacteria (MPN) in the sequencing batch biofilm reactor (SBBR) with platinum and carbon anodes.

    PubMed

    Kłodowska, Izabella; Rodziewicz, Joanna; Janczukowicz, Wojciech; Gotkowska-Płachta, Anna; Cydzik-Kwiatkowska, Agnieszka

    2016-04-15

    This work reports on the effect of electric current density and anode material (platinum, carbon) on the concentration of oxidized and mineral forms of nitrogen, on physical parameters (pH, redox potential, electrical conductivity) and the number of denitrifying bacteria in the biofilm (MPN). Experiments were conducted under anaerobic conditions without and with the flow of electric current (with density of 79 mA·m(-2) and 132 mA·m(-2)). Results obtained in the study enabled concluding that increasing density of electric current caused a decreasing concentration of nitrate in the reactor with platinum anode (R1) and carbon anode (R2). Its concentration depended on anode material. The highest hydrogenotrophic denitrification efficiency was achieved in R2 in which the process was aided by inorganic carbon (CO2) that originated from carbon anode oxidation and the electrical conductivity of wastewater increased as a result of the presence of HCO3(-) and CO3(2-) ions. Strong oxidizing properties of the platinum anode (R1) prevented the accumulation of adverse forms of nitrogen, including nitrite and ammonia. The increase in electric current density affected also a lower number of denitrifying bacteria (MPN) in the biofilm in both reactors (R1 and R2). Metal oxides accumulated on the surface of the cathode had a toxic effect upon microorganisms and impaired the production of a hydrogen donor. PMID:26809836

  9. Effects of Coke Calcination Level on Pore Structure in Carbon Anodes

    NASA Astrophysics Data System (ADS)

    Fang, Ning; Xue, Jilai; Lang, Guanghui; Bao, Chongai; Gao, Shoulei

    2016-02-01

    Effects of coke calcination levels on pore structure of carbon anodes have been investigated. Bench anodes were prepared by 3 types of cokes with 4 calcination temperatures (800°C, 900°C, 1000°C and 1100°C). The cokes and anodes were characterized using hydrostatic method, air permeability determination, mercury porosimetry, image analysis and confocal microscopy (CSLM). The cokes with different calcination levels are almost the same in LC values (19-20 Å) and real density (1.967-1.985 g/cm3), while the anode containing coke calcined at 900°C has the lowest open porosity and air permeability. Pore size distribution (represented by Anode H sample) can be roughly divided into two ranges: small and medium pores in diameter of 10-400 μm and large pores of 400-580 μm. For the anode containing coke calcined at 800°C, a number of long, narrow pores in the pore size range of 400-580 μm are presented among cokes particles. Formation of these elongated pores may be attributed to coke shrinkages during the anode baking process, which may develop cracking in the anode under cell operations. More small or medium rounded pores with pore size range of 10-400 μm emerge in the anodes with coke calcination temperatures of 900°C, 1000°C and 1100°C, which may be generated due to release of volatiles from the carbon anode during baking. For the anode containing coke calcined at 1100°C, it is found that many rounded pores often closely surround large coke particles, which have potential to form elongated, narrow pores.

  10. Confined Porous Graphene/SnOx Frameworks within Polyaniline-Derived Carbon as Highly Stable Lithium-Ion Battery Anodes.

    PubMed

    Zhou, Dan; Song, Wei-Li; Li, Xiaogang; Fan, Li-Zhen

    2016-06-01

    Tin oxides are promising anode materials for their high theoretical capacities in rechargeable lithium-ion batteries (LIBs). However, poor stability usually limits the practical application owing to the large volume variation during the cycling process. Herein, a novel carbon confined porous graphene/SnOx framework was designed using a silica template assisted nanocasting method followed by a polyaniline-derived carbon coating process. In this process, silica served as a template to anchor SnOx nanoparticles on porous framework and polyaniline was used as the carbon source for coating on the porous graphene/SnOx framework. The synthesized carbon confined porous graphene/SnOx frameworks demonstrate substantially improved rate capacities and enhanced cycling stability as the anode materials in LIBs, showing a high reversible capacity of 907 mAh g(-1) after 100 cycles at 100 mA g(-1) and 555 mAh g(-1) after 400 cycles at 1000 mA g(-1). The remarkably improved electrochemical performance could be assigned to the unique porous architecture, which effectively solves the drawbacks of SnOx including poor electrical conductivity and undesirable volume expansion during cycling process. Consequently, such design concept for promoting SnOx performance could provide a novel stage for improving anode stability in LIBs. PMID:27169479

  11. Assessing the improved performance of freestanding, flexible graphene and carbon nanotube hybrid foams for lithium ion battery anodes.

    PubMed

    Cohn, Adam P; Oakes, Landon; Carter, Rachel; Chatterjee, Shahana; Westover, Andrew S; Share, Keith; Pint, Cary L

    2014-05-01

    We demonstrate the fabrication of three-dimensional freestanding foams of hybrid graphene-single-walled carbon nanotube nanomanufactured materials with reversible capacities of 2640 mA h g(-1) at 0.186 A g(-1) and 236 mA h g(-1) at 27.9 A g(-1). The Li storage behavior of this material is compared against other nanostructures in similar flexible foam platforms including graphene, ultra-thin graphite, and single-walled carbon nanotubes (SWNTs), and we elucidate the improved hybrid material performance due to the decoupling of lithium storage reaction energetics dictated by the SWNTs from the total storage capacity of the hybrid material. This work demonstrates a route to develop mechanically robust all-carbon electrodes with the potential for reversible Li-ion storage capacity approaching silicon, power capability of the best supercapacitors, and based on a material simultaneously usable as a charge collector and anode. PMID:24647668

  12. Studies of electrolyte penetration in carbon anodes by NMR techniques.

    SciTech Connect

    Sandi, G.

    1998-12-09

    A toroid cavity nuclear magnetic resonance (NMR) detector capable of recording radial concentration profiles, diffusion constants, and displacements of charge carriers was employed to investigate the lithium ion distribution in an electrochemical cell containing a carbonaceous material synthesized from pyrene and pillared clays as inorganic templates. A carbon rod was used in a control experiment to assign the Li{sup +} spectrum and to calibrate the one dimensional radial images.

  13. Green synthesis of boron doped graphene and its application as high performance anode material in Li ion battery

    SciTech Connect

    Sahoo, Madhumita; Sreena, K.P.; Vinayan, B.P.; Ramaprabhu, S.

    2015-01-15

    Graphical abstract: Boron doped graphene (B-G), synthesized by simple hydrogen induced reduction technique using boric acid as boron precursor, have more uneven surface as a result of smaller bonding distance of boron compared to carbon, showed high capacity and high rate capability compared to pristine graphene as an anode material for Li ion battery application. - Abstract: The present work demonstrates a facile route for the large-scale, catalyst free, and green synthesis approach of boron doped graphene (B-G) and its use as high performance anode material for Li ion battery (LIB) application. Boron atoms were doped into graphene framework with an atomic percentage of 5.93% via hydrogen induced thermal reduction technique using graphite oxide and boric acid as precursors. Various characterization techniques were used to confirm the boron doping in graphene sheets. B-G as anode material shows a discharge capacity of 548 mAh g{sup −1} at 100 mA g{sup −1} after 30th cycles. At high current density value of 1 A g{sup −1}, B-G as anode material enhances the specific capacity by about 1.7 times compared to pristine graphene. The present study shows a simplistic way of boron doping in graphene leading to an enhanced Li ion adsorption due to the change in electronic states.

  14. Numerical simulation of the baking of porous anode carbon in a vertical flue ring furnace

    SciTech Connect

    Jacobsen, M.; Melaaen, M.C.

    1998-11-13

    The interaction of pitch pyrolysis in porous anode carbon during heating and volatiles combustion in the flue gas channel has been analyzed to gain insight in the anode baking process. A two-dimensional geometry of a flue gas channel adjacent to a porous flue gas wall, packing coke, and an anode was used for studying the effect of heating rate on temperature gradients and internal gas pressure in the anodes. The mathematical model included porous heat and mass transfer, pitch pyrolysis, combustion of volatiles, radiation, and turbulent channel flow. The mathematical model was developed through source code modification of the computational fluid dynamics code FLUENT. The model was useful for studying the effects of heating rate, geometry, and anode properties.

  15. Effects of anode materials on resistive characteristics of NiO thin films

    SciTech Connect

    Jia, Ze; Wang, Linkai; Zhang, Naiwen; Ren, Tianling; Liou, Juin J.

    2013-01-28

    This letter shows that the NiO-based structure with different anodes has different resistive switching properties. A conical conductive filament (CF) model is proposed for oxygen vacancies distributed in NiO films. Modeling analysis reveals much larger dissolution velocity of CF near anodes than near cathodes during the reset process. Different interfaces shown in Auger electron spectroscopy can be bound with the model to reveal that CF is dissolved in the structure with Pt or Au as anodes, while CF remains constant if the anode material is Ti or Al, which can explain whether switching properties occur in the specific NiO-based structures.

  16. Post oxygen treatment characteristics of coke as an anode material for Li-ion batteries.

    PubMed

    Kim, Jae-Hun; Park, Min-Sik; Jo, Yong Nam; Yu, Ji-Sang; Jeong, Goojin; Kim, Young-Jun

    2013-05-01

    The effect of a oxygen treatment on the electrochemical characteristics of a soft carbon anode material for Li-ion batteries was investigated. After a coke carbonization process at 1000 degrees C in an argon atmosphere, the samples were treated under a flow of oxygen gas to obtain a mild oxidation effect. After this oxygen treatment, the coke samples exhibited an improved initial coulombic efficiency and cycle performance as compared to the carbonized sample. High-resolution transmission electron microscopy revealed that the carbonized cokes consisted of disordered and nanosized graphene layers and the surface of the modified carbon was significantly changed after the treatment. The chemical state of the cokes was analyzed using X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The enhanced electrochemical properties of the surface modified cokes could be attributed to the mild oxidation effect induced by the oxygen treatment. The mild oxidation process could have led to the elimination of surface imperfections and the reinforcement of a solid electrolyte interphase film, which resulted in the improved electrochemical characteristics. PMID:23858847

  17. Porous silicon based anode material formed using metal reduction

    SciTech Connect

    Anguchamy, Yogesh Kumar; Masarapu, Charan; Deng, Haixia; Han, Yongbong; Venkatachalam, Subramanian; Kumar, Sujeet; Lopez, Herman A.

    2015-09-22

    A porous silicon based material comprising porous crystalline elemental silicon formed by reducing silicon dioxide with a reducing metal in a heating process followed by acid etching is used to construct negative electrode used in lithium ion batteries. Gradual temperature heating ramp(s) with optional temperature steps can be used to perform the heating process. The porous silicon formed has a high surface area from about 10 m.sup.2/g to about 200 m.sup.2/g and is substantially free of carbon. The negative electrode formed can have a discharge specific capacity of at least 1800 mAh/g at rate of C/3 discharged from 1.5V to 0.005V against lithium with in some embodiments loading levels ranging from about 1.4 mg/cm.sup.2 to about 3.5 mg/cm.sup.2. In some embodiments, the porous silicon can be coated with a carbon coating or blended with carbon nanofibers or other conductive carbon material.

  18. Effect of electrolyte water content on the anodic passivation of lithium in IM LiC104-propylene carbonate

    NASA Astrophysics Data System (ADS)

    James, S. D.; Nagao, A. R.

    1982-06-01

    This work deals with the effect of aqueous contamination on the anode passivation of Li in 1M LiC10 4-propylene carbonate. Passivation occurs more readily with increasing electrolyte water content. Preliminary evidence suggests that anodic passivation may be due to anodic enrichment and eventual precipitation of LiC10 4 in the superficial anolyte layer.

  19. Three-dimensional carbon nanotube-textile anode for high-performance microbial fuel cells.

    PubMed

    Xie, Xing; Hu, Liangbing; Pasta, Mauro; Wells, George F; Kong, Desheng; Criddle, Craig S; Cui, Yi

    2011-01-12

    Microbial fuel cells (MFCs) harness the metabolism of microorganisms, converting chemical energy into electrical energy. Anode performance is an important factor limiting the power density of MFCs for practical application. Improving the anode design is thus important for enhancing the MFC performance, but only a little development has been reported. Here, we describe a biocompatible, highly conductive, two-scale porous anode fabricated from a carbon nanotube-textile (CNT-textile) composite for high-performance MFCs. The macroscale porous structure of the intertwined CNT-textile fibers creates an open 3D space for efficient substrate transport and internal colonization by a diverse microflora, resulting in a 10-fold-larger anolyte-biofilm-anode interfacial area than the projective surface area of the CNT-textile. The conformally coated microscale porous CNT layer displays strong interaction with the microbial biofilm, facilitating electron transfer from exoelectrogens to the CNT-textile anode. An MFC equipped with a CNT-textile anode has a 10-fold-lower charge-transfer resistance and achieves considerably better performance than one equipped with a traditional carbon cloth anode: the maximum current density is 157% higher, the maximum power density is 68% higher, and the energy recovery is 141% greater. PMID:21158405

  20. Inorganic arsenic speciation by differential pulse anodic stripping voltammetry using thoria nanoparticles-carbon paste electrodes.

    PubMed

    Pereira, F J; Vázquez, M D; Debán, L; Aller, A J

    2016-05-15

    Two novel thoria (ThO2) nanoparticles-carbon paste electrodes were used to evaluate an anodic stripping voltammetric method for the direct determination of arsenite and total inorganic arsenic (arsenite plus arsenate) in water samples. The effect of Ag((I)), Cu((II)), Hg((II)), Sb((III)) and Se((IV)) ions on the electrochemical response of arsenic was assayed. The developed electroanalytical method offers a rapid procedure with improved analytical characteristics including good repeatability (3.4%) at low As((III)) concentrations, high selectivity, lower detection limit (0.1 μg L(-1)) and high sensitivity (0.54 μA μg(-1) L). The analytical capability of the optimized method was demonstrated by the determination of arsenic in certified reference materials (trace elements in natural water, trace elements in water and coal fly ash). PMID:26992513

  1. Automotive assessment of carbon-silicon composite anodes and methods of fabrication

    NASA Astrophysics Data System (ADS)

    Karulkar, Mohan; Blaser, Rachel; Kudla, Bob

    2015-01-01

    To assess the potential of carbon silicon composite anodes for automotive applications, C-Si anodes were fabricated and certain improvements employed. The use of a PVDF buffer layer is demonstrated for the first time with a C-Si composite material. The buffer layer increases adhesion by 89%, and increases capacity by 50-80%. Also, a limited capacity range is employed to improve cycle life by up to 200%, and enable currents as high as 2 mA cm-1. The combined use of a buffer layer and limited capacity range has not been reported before. A model is also presented for comparing C-Si performance with real-world automotive targets from USABC, including energy density, power density, specific energy, and specific power. The analysis reveals a capacity penalty that arises from pairing C-Si with a traditional cathode (NCA), and which prevents the cell from meeting all targets. Scenarios are presented in which a higher-capacity cathode (250 mAh g-1) allows all targets to be hypothetically met.

  2. Carbon supported tin-based nanocomposites as anodes for Li-ion batteries

    SciTech Connect

    Zhou, Xiangyang; Zou, Youlan; Yang, Juan

    2013-02-15

    SnO{sub 2} (Sn)/C composites as anodes for Li-ion batteries were fabricated by a simple chemical process of hydrothermal synthesis and subsequent heat treatment. The as-prepared materials were characterized by various analytic techniques. Results show that heat treatment temperature has a strong influence on physical and electrochemical performance of these composites. In these composites, irregular SnO{sub 2} lamellas arranged like chrysanthemum were dispersed among the elastic carbon matrix for rapid access of lithium ions to the material bulk. SnO{sub 2}/C anode heat-treated at a temperature of 600 Degree-Sign C exhibits a reversible capacity of 533.4 mAh/g after 50 cycles at the current density of 100 mA/g. - Graphical abstract: Chrysanthemum-like microstructures SnO{sub 2} grains expand along two-dimensional direction during cycling. The intervals among adjacent SnO{sub 2} lamellas provide the sites for lithium insertion and the space for volume expansion. After long cycling, SnO{sub 2} lamellas adhere together to form compact layers, which preserved the integrity of the structure. Highlights: Black-Right-Pointing-Pointer Carbon supported SnO{sub 2} (Sn)/C composites have been synthesized. Black-Right-Pointing-Pointer Temperature control affects the physical and electrochemical performance. Black-Right-Pointing-Pointer Clusters of chrysanthemum-like microstructures were observed. Black-Right-Pointing-Pointer Intervals exist between SnO{sub 2} layers. Black-Right-Pointing-Pointer Integrity structure of SnO{sub 2}/C composites was preserved.

  3. Sodium Titanium Phosphate as Anode Materials for Aqueous Sodium-ion Batteries

    NASA Astrophysics Data System (ADS)

    Wu, Wei

    Renewable energy technology has become one of the promising energy solutions in the future. However, limited by their cyclic behavior, large scale energy storage devices are needed to boost their adoptions in the market. The existing energy storage technologies have limitations that inhibit their adoptions for large scale applications. Our group suggests that one reasonable technology that might overcome these issues is the neutral pH aqueous electrolyte sodium-ion battery. One potential anode material is NaTi2(PO4)3, which has a relatively flexible NASICON skeleton structure and is known in general to have stable performance characteristics in extreme environments. In this work, there are four objectives to study this potential anode material: 1) Develop a rapid method to synthesize electrochemically functional NaTi2(PO4)3. In this case "Electrochemically functional" means the material can store usable capacity for practical application in a composite electrode. 2) Quantify the effect of intimate carbon on NaTi2(PO4)3 electrochemical functionality. (Electrochemical functionality regards the capacity and rate capability of electrode materials) 3) Investigate the stability of NaTi2(PO 4)3 in pH and thermal extremes and the mechanism of capacity fading under different cycling conditions. 4) Examine the performance of NaTi 2(PO4)3 in high salt concentration electrolyte and Li+ electrolyte. NaTi2(PO4)3 has been successfully synthesized via a rapid microwave method. The highest specific capacity is around 85mAh/g has been demonstrated. The effect of different carbon materials (namely graphite and carbon nanotubes) and different processes of adding them (pre and post- synthesis) on the electrochemical performance for sodium titanium phosphate has been extensively studied. Graphite coated NaTi2(PO4) 3 with carbon nanotubes composite electrode has demonstrated a specific capacity of 130mAh/g around theoretical value at 0.1C rate. The effect of the electrolyte (with

  4. Influence of Binder Adhesion Ability on the Performance of Silicon/Carbon Composite as Li-Ion Battery Anode

    NASA Astrophysics Data System (ADS)

    Kierzek, Krzysztof

    2016-04-01

    A series of anodes for Li-ion battery was prepared by conventional homogenization of active material, percolator, and Na-CMC or several kinds of PVDF as a binder. Si/C composite was synthesized by embedding micro-sized silicon and synthetic battery-grade graphite in a pitch-derived carbon matrix and taken as active material. Adhesion strength of anodic film to a current collector was determined by peeling test. Thermal relaxation (120-180 °C) after calendering of PVDF-based anode slightly increases the adhesion of the film to the collector. The highest peeling strength was recorded for ultrahigh molecular weight PVDF (~0.05 N cm-1) but without advantage for cycling stability of the cell. An initial reversible capacity of 512 mAh g-1, with average capacity decay only of 0.5% per cycle, was achieved for CMC-based anode of moderate peeling strength (~0.035 N cm-1). Such good performance was attributed to a specific Si/C composite structure as well as profitable physicochemical properties of the binder.

  5. Influence of Binder Adhesion Ability on the Performance of Silicon/Carbon Composite as Li-Ion Battery Anode

    NASA Astrophysics Data System (ADS)

    Kierzek, Krzysztof

    2016-06-01

    A series of anodes for Li-ion battery was prepared by conventional homogenization of active material, percolator, and Na-CMC or several kinds of PVDF as a binder. Si/C composite was synthesized by embedding micro-sized silicon and synthetic battery-grade graphite in a pitch-derived carbon matrix and taken as active material. Adhesion strength of anodic film to a current collector was determined by peeling test. Thermal relaxation (120-180 °C) after calendering of PVDF-based anode slightly increases the adhesion of the film to the collector. The highest peeling strength was recorded for ultrahigh molecular weight PVDF (~0.05 N cm-1) but without advantage for cycling stability of the cell. An initial reversible capacity of 512 mAh g-1, with average capacity decay only of 0.5% per cycle, was achieved for CMC-based anode of moderate peeling strength (~0.035 N cm-1). Such good performance was attributed to a specific Si/C composite structure as well as profitable physicochemical properties of the binder.

  6. Controlled modification of carbon nanotubes and polyaniline on macroporous graphite felt for high-performance microbial fuel cell anode

    NASA Astrophysics Data System (ADS)

    Cui, Hui-Fang; Du, Lin; Guo, Peng-Bo; Zhu, Bao; Luong, John H. T.

    2015-06-01

    Polyaniline (PANI) was electropolymerized on the surface of macroporous graphite felt (GF) followed by the electrophoretic deposition of carbon nanotubes (CNTs). The as-prepared macroporous material was characterized by scanning electron microscopy, water contact angle goniometry and electrochemical techniques. Upon the modification of PANI, a rough and nano-cilia containing film is coated on the surface of the graphite fibers, transforming the surface from hydrophobic to hydrophilic. The subsequent modification by CNTs increases the effective surface area and electrical conductivity of the resulting material. The power output of a mediator-free dual-chamber microbial fuel cell (MFC) constructed from the GF anode and an exoelectrogen Shewanella putrefaciens increases drastically with the CNT modification. The CNT/PANI/GF MFC attains an output voltage of 342 mV across an external resistor of 1.96 kΩ constant load, and a maximum power density of 257 mW m-2, increased by 343% and 186%, compared to that of the pristine GF MFC and the PANI/GF MFC, respectively. More bacteria are attached on the CNT/PANI/GF anode than on the PANI/GF anode during the working of the MFC. This strategy provides an easy scale-up, simple and controllable method for the preparation of high-performance and low-cost MFC anodes.

  7. Pyrolytic carbon-coated silicon/carbon nanofiber composite anodes for high-performance lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Chen, Yanli; Hu, Yi; Shao, Jianzhong; Shen, Zhen; Chen, Renzhong; Zhang, Xiangwu; He, Xia; Song, Yuanze; Xing, Xiuli

    2015-12-01

    Pyrolytic carbon-coated Si/C nanofibers (Si/C-CNFs) composites have been prepared through the sucrose coating and secondary thermal treatment of Si/CNFs composites produced via electrospinning and carbonization. This results in a structure in which Si nanoparticles are distributed along the fibers, with the fiber surface being coated with an amorphous carbon layer through pyrolysis of the sucrose. This carbon coating not only limits the volume expansion of the exposed Si nanoparticles, preventing their direct contact with the electrolyte, but also creates a connection between the fibers that is beneficial to Li+ ion transport, structural integrity, and electrochemical conductivity. Consequently, the Si/C-CNFs composite exhibits a more stable cycle performance, better rate performance, and higher conductivity than Si/CNFs alone. The optimal level of performance was attained with a 20:200 mass ratio of sucrose to deionized water, with a high retained capacity of 1215.2 mAh g-1 after 50 cycles, thus indicating that it is a suitable anode material for Li-ion batteries.

  8. Ultra strong silicon-coated carbon nanotube nonwoven fabric as a multifunctional lithium-ion battery anode.

    PubMed

    Evanoff, Kara; Benson, Jim; Schauer, Mark; Kovalenko, Igor; Lashmore, David; Ready, W Jud; Yushin, Gleb

    2012-11-27

    Materials that can perform simultaneous functions allow for reductions in the total system mass and volume. Developing technologies to produce flexible batteries with good performance in combination with high specific strength is strongly desired for weight- and power-sensitive applications such as unmanned or aerospace vehicles, high-performance ground vehicles, robotics, and smart textiles. State of the art battery electrode fabrication techniques are not conducive to the development of multifunctional materials due to their inherently low strength and conductivities. Here, we present a scalable method utilizing carbon nanotube (CNT) nonwoven fabric-based technology to develop flexible, electrochemically stable (∼494 mAh·g(-1) for 150 cycles) battery anodes that can be produced on an industrial scale and demonstrate specific strength higher than that of titanium, copper, and even a structural steel. Similar methods can be utilized for the formation of various cathode and anode composites with tunable strength and energy and power densities. PMID:23075213

  9. Pyrene-Anderson-Modified CNTs as Anode Materials for Lithium-Ion Batteries.

    PubMed

    Huang, Lujiang; Hu, Jun; Ji, Yuanchun; Streb, Carsten; Song, Yu-Fei

    2015-12-14

    An organo-functionalized polyoxometalate (POM)-pyrene hybrid (Py-Anderson) has been used for noncovalent functionalization of carbon nanotubes (CNTs) to give a Py-Anderson-CNT nanocomposite through π-π interactions. The as-synthesized nanocomposite was used as the anode material for lithium-ion batteries, and shows higher discharge capacities and better rate capacity and cycling stability than the individual components. When the current density was 0.5 mA cm(-2), the nanocomposite exhibited an initial discharge capacity of 1898.5 mA h g(-1) and a high discharge capacity of 665.3 mA h g(-1) for up to 100 cycles. AC impedance spectroscopy provides insight into the electrochemical properties and the charge-transfer mechanism of the Py-Anderson-CNTs electrode. PMID:26538031

  10. Application of infiltrated LSCM-GDC oxide anode in direct carbon/coal fuel cells.

    PubMed

    Yue, Xiangling; Arenillas, Ana; Irvine, John T S

    2016-08-15

    Hybrid direct carbon/coal fuel cells (HDCFCs) utilise an anode based upon a molten carbonate salt with an oxide conducting solid electrolyte for direct carbon/coal conversion. They can be fuelled by a wide range of carbon sources, and offer higher potential chemical to electrical energy conversion efficiency and have the potential to decrease CO2 emissions compared to coal-fired power plants. In this study, the application of (La, Sr)(Cr, Mn)O3 (LSCM) and (Gd, Ce)O2 (GDC) oxide anodes was explored in a HDCFC system running with two different carbon fuels, an organic xerogel and a raw bituminous coal. The electrochemical performance of the HDCFC based on a 1-2 mm thick 8 mol% yttria stabilised zirconia (YSZ) electrolyte and the GDC-LSCM anode fabricated by wet impregnation procedures was characterized and discussed. The infiltrated oxide anode showed a significantly higher performance than the conventional Ni-YSZ anode, without suffering from impurity formation under HDCFC operation conditions. Total polarisation resistance (Rp) reached 0.8-0.9 Ω cm(2) from DCFC with an oxide anode on xerogel and bituminous coal at 750 °C, with open circuit voltage (OCV) values in the range 1.1-1.2 V on both carbon forms. These indicated the potential application of LSCM-GDC oxide anode in HDCFCs. The chemical compatibility of LSCM/GDC with carbon/carbonate investigation revealed the emergence of an A2BO4 type oxide in place of an ABO3 perovskite structure in the LSCM in a reducing environment, due to Li attack as a result of intimate contact between the LSCM and Li2CO3, with GDC being stable under identical conditions. Such reaction between LSCM and Li2CO3 was not observed on a LSCM-YSZ pellet treated with Li-K carbonate in 5% H2/Ar at 700 °C, nor on a GDC-LSCM anode after HDCFC operation. The HDCFC durability tests of GDC-LSCM oxide on a xerogel and on raw bituminous coal were performed under potentiostatic operation at 0.7 V at 750 °C. The degradation mechanisms were

  11. Energy Storage Materials from Nature through Nanotechnology: A Sustainable Route from Reed Plants to a Silicon Anode for Lithium-Ion Batteries.

    PubMed

    Liu, Jun; Kopold, Peter; van Aken, Peter A; Maier, Joachim; Yu, Yan

    2015-08-10

    Silicon is an attractive anode material in energy storage devices, as it has a ten times higher theoretical capacity than its state-of-art carbonaceous counterpart. However, the common process to synthesize silicon nanostructured electrodes is complex, costly, and energy-intensive. Three-dimensional (3D) porous silicon-based anode materials have been fabricated from natural reed leaves by calcination and magnesiothermic reduction. This sustainable and highly abundant silica source allows for facile production of 3D porous silicon with very good electrochemical performance. The obtained silicon anode retains the 3D hierarchical architecture of the reed leaf. Impurity leaching and gas release during the fabrication process leads to an interconnected porosity and the reductive treatment to an inside carbon coating. Such anodes show a remarkable Li-ion storage performance: even after 4000 cycles and at a rate of 10 C, a specific capacity of 420 mA h g(-1) is achieved. PMID:26119499

  12. Bone Cell–materials Interactions and Ni Ion Release of Anodized Equiatomic NiTi Alloy

    PubMed Central

    Bernard, Sheldon A.; Balla, Vamsi Krishna; Davies, Neal M.; Bose, Susmita; Bandyopadhyay, Amit

    2011-01-01

    Laser processed NiTi alloy was anodized for different durations in H2SO4 electrolyte with varying pH to create biocompatible surfaces with low Ni ion release as well as bioactive surfaces to enhance biocompatibility and bone cell-materials interactions. The anodized surfaces were assessed for their in vitro cell-materials interactions using human fetal osteoblast (hFOB) cells for 3, 7 and 11 days, and Ni ion release up to 8 weeks in simulated body fluids. The results were correlated with surface morphologies of anodized surfaces characterized using field-emission scanning electron microscopy (FESEM). The results show that the anodization creates a surface with nano/micro roughness depending on anodization conditions. The hydrophilicity of NiTi surface was found to improve after anodization due to lower contact angles in cell media, which dropped from 32° to < 5°. The improved wettability of anodized surfaces is further corroborated by their high surface energy comparable to that of cp Ti. Relatively high surface energy, especially polar component, and nano/micro surface features of anodized surfaces significantly increased the number of living cells and their adherence and growth on these surfaces. Finally, a significant drop in Ni ion release from 268 ± 11 to 136 ± 15 ppb was observed for NiTi surfaces after anodization. This work indicates that anodization of NiTi alloy has a positive influence on the surface energy and surface morphology, which in turn improve bone cell-materials interactions and reduce Ni ion release in vitro. PMID:21232641

  13. Mesoporous carbon materials

    DOEpatents

    Dai, Sheng; Fulvio, Pasquale Fernando; Mayes, Richard T.; Wang, Xiqing; Sun, Xiao-Guang; Guo, Bingkun

    2014-09-09

    A conductive mesoporous carbon composite comprising conductive carbon nanoparticles contained within a mesoporous carbon matrix, wherein the conductive mesoporous carbon composite possesses at least a portion of mesopores having a pore size of at least 10 nm and up to 50 nm, and wherein the mesopores are either within the mesoporous carbon matrix, or are spacings delineated by surfaces of said conductive carbon nanoparticles when said conductive carbon nanoparticles are fused with each other, or both. Methods for producing the above-described composite, devices incorporating them (e.g., lithium batteries), and methods of using them, are also described.

  14. High-Capacity Te Anode Confined in Microporous Carbon for Long-Life Na-Ion Batteries.

    PubMed

    Zhang, Juan; Yin, Ya-Xia; Guo, Yu-Guo

    2015-12-23

    Sodium-ion batteries (SIBs) have attracted considerable attention as an alternative energy-storage technology in recent years. Developing advanced sodium storage anode materials with appropriate working potential, high capacity, and good cycling performance is very important. Herein, we demonstrate a nanostructured tellurium@carbon (nano-Te@C) composite by confining nano-Te molecules in the space of carbon micropores as an attractive anode material for SIBs. The nano-Te@C anode presents an appropriate redox potential in the range of 1.05-1.35 V (vs Na(+)/Na), which avoids the Na dendrite problem and achieves a high reversible capacity of 410 mA h g(-1) on the basis of a two-electron redox reaction mechanism. Notably, the nano-Te@C exhibits an admirable long-term cycling stability with a high capacity retention of 90% for 1000 cycles (i.e., ultralow capacity decay of 0.01% per cycle). The excellent electrochemical property of nano-Te@C benefits from the high electroactivity from the nanostructure design and the effective confinement of the microporous carbon host. In addition, a Na-ion full cell by using nano-Te@C as anode and Na2/3Ni1/3Mn2/3O2 as cathode is demonstrated for the first time and exhibits a remarkable capacity retention up to 95% after 150 cycles. The results put new insights for the development of advanced SIBs with long-cycle lifespan. PMID:26618232

  15. Facile synthesis of reduced graphene oxide-porous silicon composite as superior anode material for lithium-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Jiao, Lian-Sheng; Liu, Jin-Yu; Li, Hong-Yan; Wu, Tong-Shun; Li, Fenghua; Wang, Hao-Yu; Niu, Li

    2016-05-01

    We report a new method for synthesizing reduced graphene oxide (rGO)-porous silicon composite for lithium-ion battery anodes. Rice husks were used as a as a raw material source for the synthesis of porous Si through magnesiothermic reduction process. The as-obtained composite exhibits good rate and cycling performance taking advantage of the porous structure of silicon inheriting from rice husks and the outstanding characteristic of graphene. A considerably high delithiation capacity of 907 mA h g-1 can be retained even at a rate of 16 A g-1. A discharge capacity of 830 mA h g-1 at a current density of 1 A g-1 was delivered after 200 cycles. This may contribute to the further advancement of Si-based composite anode design.

  16. Facile synthesis of reduced graphene oxide-porous silicon composite as superior anode material for lithium-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Jiao, Lian-Sheng; Liu, Jin-Yu; Li, Hong-Yan; Wu, Tong-Shun; Li, Fenghua; Wang, Hao-Yu; Niu, Li

    2016-05-01

    We report a new method for synthesizing reduced graphene oxide (rGO)-porous silicon composite for lithium-ion battery anodes. Rice husks were used as a as a raw material source for the synthesis of porous Si through magnesiothermic reduction process. The as-obtained composite exhibits good rate and cycling performance taking advantage of the porous structure of silicon inheriting from rice husks and the outstanding characteristic of graphene. A considerably high delithiation capacity of 907 mA h g-1 can be retained even at a rate of 16 A g-1. A discharge capacity of 830 mA h g-1 at a current density of 1 A g-1 was delivered after 200 cycles. This may contribute to the further advancement of Si-based composite anode design.

  17. Antimony nanoparticles anchored in three-dimensional carbon network as promising sodium-ion battery anode

    NASA Astrophysics Data System (ADS)

    Luo, Wen; Zhang, Pengfei; Wang, Xuanpeng; Li, Qidong; Dong, Yifan; Hua, Jingchen; Zhou, Liang; Mai, Liqiang

    2016-02-01

    A novel composite with antimony (Sb) nanoparticles anchored in three-dimensional carbon network (denoted as SbNPs@3D-C) is successfully synthesized via a NaCl template-assisted self-assembly strategy, followed by freeze-drying and one-step in-situ carbonization. The three-dimensional interconnected macroporous carbon framework can not only stabilize the architecture and buffer the volume expansion for Sb nanoparticles, but also provide high electrical conductivity for the whole electrode. Consequently, as a sodium-ion battery anode, the SbNPs@3D-C delivers a high reversible capacity (456 mAh g-1 at 100 mA g-1), stable cycling performance (94.3% capacity retention after 500 cycles at 100 mA g-1) as well as superior rate capability (270 mAh g-1 at 2000 mA g-1). When compared with commercial Sb particles, the SbNPs@3D-C exhibits dramatically enhanced electrochemical performance. Free from expensive template sources and complex manipulation, this work might shed some light on the synthesis of low-cost and high-performance materials for the next "beyond lithium" battery generation.

  18. Anodic polymerization of vinyl ethylene carbonate in Li-Ion battery electrolyte

    SciTech Connect

    Chen, Guoying; Zhuang, Guorong V.; Richardson, Thomas J.; Gao, Liu; Ross Jr., Philip N.

    2005-02-28

    A study of the anodic oxidation of vinyl ethylene carbonate (VEC) was conducted with post-mortem analysis of reaction products by ATR-FTIR and gel permeation chromatography (GPC). The half-wave potential (E1/2) for oxidation of VEC is ca. 3.6 V producing a resistive film on the electrode surface. GPC analysis of the film on a gold electrode produced by anodization of a commercial Li-ion battery electrolyte containing 2 percent VEC at 4.1 V showed the presence of a high molecular weight polymer. IR analysis indicated polycarbonate with alkyl carbonate rings linked by aliphatic methylene and methyl branches.

  19. Binder-free carbon black/stainless steel mesh composite electrode for high-performance anode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Zheng, Suqi; Yang, Fangfang; Chen, Shuiliang; Liu, Lang; Xiong, Qi; Yu, Ting; Zhao, Feng; Schröder, Uwe; Hou, Haoqing

    2015-06-01

    Carbon black/stainless steel mesh (CB/SSM) composite electrodes were developed as high-performance anodes of microbial fuel cell (MFC) by using a binder-free dipping/drying method. The acid-treatment and thin layer of CB coating greatly improved the microbial adhesion of the electrode surface and facilitated the electron transfer between the bacteria and the electrode surface. As a result, a single-layer CB/SSM anode with thickness of 0.3 mm could generate a projected current density of about 1.53 ± 0.15 mA cm-2 and volumetic current density of 51.0 ± 5.0 mA cm-3, which was much higher than that of the bare SSM anode and conventional carbon felt anode with thickness of 2 mm. Moreover, three-dimensional (3D) CB/SSM electrode could be prepared by simple folding the singe-layer SSM, and produced a projected current density to 10.07 ± 0.88 mA cm-2 and a volumetric current density of 18.66 ± 1.63 mA cm-3. The MFC equipped with the 3D-CB/SSM anode produced a high maximum power density of 3215 ± 80 mW m-2. The CB/SSM electrodes showed good mechanical and electrical properties, excellent microbial adhesion; it represented a high-performance, low-cost electrode material that is easy to fabricate and scale-up.

  20. In-line inspection of carbon anodes for use in aluminum production

    SciTech Connect

    Emad, F.; Haldemann, P.; Nispel, A.; Logan, L.

    1996-10-01

    In this paper, methods of measuring the quality of carbon anodes which are produced and continually consumed in the commercial production of aluminum are discussed. The electrical and mechanical qualities of these anodes are very important for the economic operation of the aluminum plant. At least six different ways of checking some of the most important anode characteristics were investigated, and those methods selected as the most suitable for testing the quality of the anodes are elaborated. Results from tests made at an aluminum reduction plant are included. Future work planned in this area is also discussed. The methods considered include: (1) direct resistivity measurement using core samples; (2) ultrasonic measurement; (3) hammer method; (4) Hall effect; (5) 4-probe method; (6) magnetic coils (various arrangements). It will be shown that some of these methods give inaccurate results while others are not practical due to operating conditions and/or production parameters.

  1. High-performance flexible nanoporous Si-carbon nanotube paper anodes for micro-battery applications

    NASA Astrophysics Data System (ADS)

    Biserni, Erika; Scarpellini, Alice; Li Bassi, Andrea; Bruno, Paola; Zhou, Yun; Xie, Ming

    2016-06-01

    Nanoporous Si has been grown by pulsed laser deposition on a free-standing carbon nanotube (CNT) paper sheet for micro-battery anodes. The Si deposition shows conformal coverage on the CNT paper, and the Si-CNT paper anodes demonstrate high areal capacity of ∼1000 μAh cm‑2 at a current density of 54 μA cm‑2, while 69% of its initial capacity is preserved when the current density is increased by a factor 10. Excellent stability without capacity decay up to 1000 cycles at a current density of 1080 μA cm‑2 is also demonstrated. After bending along the diameter of the circular paper disc many times, the Si-CNT paper anodes preserve the same morphology and show promising electrochemical performance, indicating that nanoporous Si-CNT paper anodes can find application for flexible micro-batteries.

  2. An investigation of anode and cathode materials in photomicrobial fuel cells.

    PubMed

    Schneider, Kenneth; Thorne, Rebecca J; Cameron, Petra J

    2016-02-28

    Photomicrobial fuel cells (p-MFCs) are devices that use photosynthetic organisms (such as cyanobacteria or algae) to turn light energy into electrical energy. In a p-MFC, the anode accepts electrons from microorganisms that are either growing directly on the anode surface (biofilm) or are free floating in solution (planktonic). The nature of both the anode and cathode material is critical for device efficiency. An ideal anode is biocompatible and facilitates direct electron transfer from the microorganisms, with no need for an electron mediator. For a p-MFC, there is the additional requirement that the anode should not prevent light from perfusing through the photosynthetic cells. The cathode should facilitate the rapid reaction of protons and oxygen to form water so as not to rate limit the device. In this paper, we first review the range of anode and cathode materials currently used in p-MFCs. We then present our own data comparing cathode materials in a p-MFC and our first results using porous ceramic anodes in a mediator-free p-MFC. PMID:26755764

  3. A hierarchical Zn2Mo3O8 nanodots-porous carbon composite as a superior anode for lithium-ion batteries.

    PubMed

    Zhu, Yanping; Zhong, Yijun; Chen, Gao; Deng, Xiang; Cai, Rui; Li, Li; Shao, Zongping

    2016-08-01

    A hierarchical Zn2Mo3O8 nanodots-porous carbon composite has been successfully synthesized via the ingenious combination of ion exchange and molten salt strategies, and the composite exhibits remarkable performance as an anode material for lithium-ion batteries. PMID:27374699

  4. Scalable synthesis of interconnected porous silicon/carbon composites by the Rochow reaction as high-performance anodes of lithium ion batteries.

    PubMed

    Zhang, Zailei; Wang, Yanhong; Ren, Wenfeng; Tan, Qiangqiang; Chen, Yunfa; Li, Hong; Zhong, Ziyi; Su, Fabing

    2014-05-12

    Despite the promising application of porous Si-based anodes in future Li ion batteries, the large-scale synthesis of these materials is still a great challenge. A scalable synthesis of porous Si materials is presented by the Rochow reaction, which is commonly used to produce organosilane monomers for synthesizing organosilane products in chemical industry. Commercial Si microparticles reacted with gas CH3 Cl over various Cu-based catalyst particles to substantially create macropores within the unreacted Si accompanying with carbon deposition to generate porous Si/C composites. Taking advantage of the interconnected porous structure and conductive carbon-coated layer after simple post treatment, these composites as anodes exhibit high reversible capacity and long cycle life. It is expected that by integrating the organosilane synthesis process and controlling reaction conditions, the manufacture of porous Si-based anodes on an industrial scale is highly possible. PMID:24700513

  5. TiO2 anode materials for lithium-ion batteries with different morphology and additives

    NASA Astrophysics Data System (ADS)

    Liu, Xiang; Ng, Yip Hang; Leung, Yu Hang; Liu, Fangzhou; Djurišic, Aleksandra B.; Xie, Mao Hai; Chan, Wai Kin

    2014-03-01

    Electrochemical performances of different TiO2 nanostructures, TiO2/CNT composite and TiO2 with titanium isopropoxide (TTIP) treatment anode were investigated. For different TiO2 nanostructures, we investigated vertically aligned TiO2 nanotubes on Ti foil and TiO2 nanotube-powders fabricated by rapid breakdown anodization technique. The morphology of the prepared samples was characterized by scanning probe microscopy (SEM). The electrochemical lithium storage abilities were studied by galvanostatic method. In addition, carbon nanotubes (CNT) additives and solution treatment process of TiO2 anode were investigated, and the results show that the additives and treatment could enhance the cycling performance of the TiO2 anode on lithium ion batteries.

  6. Additive-free thick graphene film as an anode material for flexible lithium-ion batteries.

    PubMed

    Rana, Kuldeep; Kim, Seong Dae; Ahn, Jong-Hyun

    2015-04-28

    This work demonstrates a simple route to develop mechanically flexible electrodes for Li-ion batteries (LIBs) that are usable as lightweight effective conducting networks for both cathodes and anodes. Removing electrochemically dead elements, such as binders, conducting agents and metallic current collectors, from the battery components will allow remarkable progress in this area. To investigate the feasibility of using thick, additive-free graphene films as anodes for flexible LIBs, we have synthesized and tested thick, additive-free, freestanding graphene films as anodes, first in a coin cell and further in a flexible full cell. As an anode material in a half cell, it showed a discharge capacity of about 350 mA h g(-1) and maintained nearly this capacity over 50 cycles at various current rates. This film was also tested as an anode material in a full cell with a LiCoO2 cathode and showed good electrochemical performance. Because the graphene-based flexible film showed good performance in half- and full coin cells, we used this film as a flexible anode for flexible LIBs. No conducting agent or binder was used in the anode side, which helped in realizing the flexible LIBs. Using this, we demonstrate a thin, lightweight and flexible lithium ion battery with good electrochemical performance in both its flat and bent states. PMID:25587843

  7. Inert anodes for aluminum smelting

    SciTech Connect

    Weyand, J.D.; Ray, S.P.; Baker, F.W.; DeYoung, D.H.; Tarcy, G.P.

    1986-02-01

    The use of nonconsumable or inert anodes for replacement of consumable carbon anodes in Hall electrolysis cells for the production of aluminum has been a technical and commercial goal of the aluminum industry for many decades. This report summarizes the technical success realized in the development of an inert anode that can be used to produce aluminum of acceptable metal purity in small scale Hall electrolysis cells. The inert anode material developed consists of a cermet composition containing the phases: copper, nickel ferrite and nickel oxide. This anode material has an electrical conductivity comparable to anode carbon used in Hall cells, i.e., 150 ohm {sup {minus}1}cm{sup {minus}1}. Metal purity of 99.5 percent aluminum has been produced using this material. The copper metal alloy present in the anode is not removed by anodic dissolution as does occur with cermet anodes containing a metallic nickel alloy. Solubility of the oxide phases in the cryolite electrolyte is reduced by: (1) saturated concentration of alumina, (2) high nickel oxide content in the NiO-NiFe{sub 2}O{sub 4} composition, (3) lowest possible cell operating temperature, (4) additions of alkaline or alkaline earth fluorides to the bath to reduce solubilities of the anode components, and (5) avoiding bath contaminants such as silica. Dissolution rate measurements indicate first-order kinetics and that the rate limiting step for dissolution is mass transport controlled. 105 refs., 234 figs., 73 tabs.

  8. Anode sheath transition in an anodic arc for synthesis of nanomaterials

    NASA Astrophysics Data System (ADS)

    Nemchinsky, V. A.; Raitses, Y.

    2016-06-01

    The arc discharge with ablating anode or so-called anodic arc is widely used for synthesis of nanomaterials, including carbon nanotubes and fullerens, metal nanoparticles etc. We present the model of this arc, which confirms the existence of the two different modes of the arc operation with two different anode sheath regimes, namely, with negative anode sheath and with positive anode sheath. It was previously suggested that these regimes are associated with two different anode ablating modes—low ablation mode with constant ablation rate and the enhanced ablation mode (Fetterman et al 2008 Carbon 46 1322). The transition of the arc operation from low ablation mode to high ablation mode is determined by the current density at the anode. The model can be used to self-consistently determine the distribution of the electric field, electron density and electron temperature in the near-anode region of the arc discharge. Simulations of the carbon arc predict that for low arc ablating modes, the current is driven mainly by the electron diffusion to the anode. For positive anode sheath, the anode voltage is close to the ionization potential of anode material, while for negative anode sheath, the anode voltage is an order of magnitude smaller. It is also shown that the near-anode plasma, is far from the ionization equilibrium.

  9. Results from a 100-hour electrolysis test of cermet anode: Materials aspects

    SciTech Connect

    Strachan, D.M.; Koski, O.H.; Morgan, L.G.; Westerman, R.E. ); Peterson, R.D.; Richards, N.E.; Tabereaux, A.T. . Mfg. Technology Lab.)

    1990-02-01

    Extensive materials examination were conducted following testing of a 15-cm-diameter prototype cermet anode. The anode was cut in half and samples were taken that were above, at, and below the electrolyte. The microstructure and phases were found to be different in each of these areas. For instance, the copper oxidized to CuO above the electrolyte, but Cu{sub 2}O appeared to be the favored oxidation product in the anode sample in the electrolyte. 9 refs., 14 figs.

  10. Carbon deposition thresholds on nickel-based solid oxide fuel cell anodes II. Steam:carbon ratio and current density

    NASA Astrophysics Data System (ADS)

    Kuhn, J.; Kesler, O.

    2015-03-01

    For the second part of a two part publication, coking thresholds with respect to molar steam:carbon ratio (SC) and current density in nickel-based solid oxide fuel cells were determined. Anode-supported button cell samples were exposed to 2-component and 5-component gas mixtures with 1 ≤ SC ≤ 2 and zero fuel utilization for 10 h, followed by measurement of the resulting carbon mass. The effect of current density was explored by measuring carbon mass under conditions known to be prone to coking while increasing the current density until the cell was carbon-free. The SC coking thresholds were measured to be ∼1.04 and ∼1.18 at 600 and 700 °C, respectively. Current density experiments validated the thresholds measured with respect to fuel utilization and steam:carbon ratio. Coking thresholds at 600 °C could be predicted with thermodynamic equilibrium calculations when the Gibbs free energy of carbon was appropriately modified. Here, the Gibbs free energy of carbon on nickel-based anode support cermets was measured to be -6.91 ± 0.08 kJ mol-1. The results of this two part publication show that thermodynamic equilibrium calculations with appropriate modification to the Gibbs free energy of solid-phase carbon can be used to predict coking thresholds on nickel-based anodes at 600-700 °C.

  11. Development of Low Cost Carbonaceous Materials for Anodes in Lithium-Ion Batteries for Electric and Hybrid Electric Vehicles

    SciTech Connect

    Barsukov, Igor V.

    2002-12-10

    Final report on the US DOE CARAT program describes innovative R & D conducted by Superior Graphite Co., Chicago, IL, USA in cooperation with researchers from the Illinois Institute of Technology, and defines the proper type of carbon and a cost effective method for its production, as well as establishes a US based manufacturer for the application of anodes of the Lithium-Ion, Lithium polymer batteries of the Hybrid Electric and Pure Electric Vehicles. The three materials each representing a separate class of graphitic carbon, have been developed and released for field trials. They include natural purified flake graphite, purified vein graphite and a graphitized synthetic carbon. Screening of the available on the market materials, which will help fully utilize the graphite, has been carried out.

  12. Amine-terminated ionic liquid functionalized carbon nanotubes for enhanced interfacial electron transfer of Shewanella putrefaciens anode in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Wei, Huan; Wu, Xiao-Shuai; Zou, Long; Wen, Guo-Yun; Liu, Ding-Yu; Qiao, Yan

    2016-05-01

    An amine-terminated ionic liquid (IL-NH2) is applied to functionalize carbon nanotubes (CNTs) for improving the interfacial electron transfer of Shewanella putrefaciens (S. putrefaciens) anode in Microbial fuel cells (MFCs). The introduction of thin layer of ILs does not change the morphology of CNTs a lot but increases surface positive charges as well as nitrogen functional groups of the CNTs based anode. The CNT-IL composite not only improves the adhesion of S. putrefaciens cells but also promotes both of the flavin-mediated and the direct electron transfer between the S. putrefaciens cells and the anode. It is interesting that the CNT-IL is more favorable for the mediated electron transfer than for the direct electron transfer. The CNT-IL/carbon cloth anode delivers 3-fold higher power density than that of CNT anode and shows great long-term stability in the batch-mode S. putrefaciens MFCs. This CNT-IL could be a promising anode material for high performance MFCs.

  13. The influence of carbon dioxide on PEM fuel cell anodes

    NASA Astrophysics Data System (ADS)

    de Bruijn, F. A.; Papageorgopoulos, D. C.; Sitters, E. F.; Janssen, G. J. M.

    The influence of CO 2 on the performance of PEM fuel cells was investigated by means of fuel cell experiments and cyclic voltammetry. Depending on the composition and microstructure of the fuel cell anode, the effect varies from small to significant. Adsorbed hydrogen plays a dominant role in the formation of CO-like species via the reverse water-gas shift reaction. Platinum sites which are not utilized in the electrochemical oxidation of hydrogen are thought to catalyze this reverse-shift reaction. Alloying with ruthenium suppresses the reverse-shift reaction.

  14. Electrochemical properties of carbon-coated Si/B composite anode for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Kim, Hyung Sun; Chung, Kyung Yoon; Cho, Byung Won

    Carbon-coated Si and Si/B composite powders prepared by hydrocarbon gas (argon + 10 mol% propylene) pyrolysis were investigated as the anodes for lithium-ion batteries. Carbon-coated silicon anode demonstrated the first discharge and charge capacity as 1568 mAh g -1 and 1242 mAh g -1, respectively, with good capacity retention for 10 cycles. The capacity fading rate of carbon-coated Si/B composite anode decreased as the amounts of boron increased. In addition, the cycle life of carbon-coated Si/B/graphite composite anode has been significantly improved by using sodium carboxymethyl cellulose (NaCMC) and styrene butadiene rubber (SBR)/NaCMC mixture binders compared to the poly(vinylidene fluoride, PVdF) binder. A reversible capacity of about 550 mAh g -1 has been achieved at 0.05 mAm g -1 rate and its capacity could be maintained up to 450 mAh g -1 at high rate of 0.2 mAm g -1 even after 30 cycles. The improvement of the cycling performance is attributed to the lower interfacial resistance due to good electric contact between silicon particles and copper substrate.

  15. Anodization of carbon fibers on interfacial mechanical properties of epoxy matrix composites.

    PubMed

    Park, Soo-Jin; Chang, Yong-Hwan; Kim, Yeong-Cheol; Rhee, Kyong-Yop

    2010-01-01

    The influence of anodic oxidation on the mechanical interfacial properties of carbon-fiber-reinforced epoxy resin composites was investigated. The surface properties of the anodized carbon fibers were studied through the measurement of contact angles and through SEM, XPS, and FT-IR analyses. The mechanical interfacial properties of the composites were studied through measurements of interlaminar shear strength (ILSS), critical stress intensity factor (K(IC)), and critical strain energy release rate (G(IC)). It was shown that the surface functional groups containing oxygen on the anodized carbon fibers exert great effects on the surface energetics of fibers and the mechanical interfacial properties, e.g., ILSS, of the resulting composites. Contact angle measurements based on the wicking rate of a test liquid showed that anodic oxidation lead to an increase in the surface free energy of the carbon fibers, mainly in its specific (or polar) component. In terms of surface energetics, it was found that wetting played an important role in increasing the degree of adhesion at interfaces between the fibers and the resin matrices of the composites. PMID:20352820

  16. A lithium air battery with a lithiated Al-carbon anode.

    PubMed

    Guo, Ziyang; Dong, XiaoLi; Wang, Yonggang; Xia, Yongyao

    2015-01-14

    A lithiated Al-carbon composite electrode with a uniform SEI film was prepared by an electrochemical method, and was then coupled with an O2 catalytic electrode to form a rechargeable Li-O2 (or air) battery with a LixAl-C anode. PMID:25415761

  17. Sustainable design of high-performance microsized microbial fuel cell with carbon nanotube anode and air cathode.

    PubMed

    Mink, Justine E; Hussain, Muhammad Mustafa

    2013-08-27

    Microbial fuel cells (MFCs) are a promising alternative energy source that both generates electricity and cleans water. Fueled by liquid wastes such as wastewater or industrial wastes, the microbial fuel cell converts waste into energy. Microsized MFCs are essentially miniature energy harvesters that can be used to power on-chip electronics, lab-on-a-chip devices, and/or sensors. As MFCs are a relatively new technology, microsized MFCs are also an important rapid testing platform for the comparison and introduction of new conditions or materials into macroscale MFCs, especially nanoscale materials that have high potential for enhanced power production. Here we report a 75 μL microsized MFC on silicon using CMOS-compatible processes and employ a novel nanomaterial with exceptional electrochemical properties, multiwalled carbon nanotubes (MWCNTs), as the on-chip anode. We used this device to compare the usage of the more commonly used but highly expensive anode material gold, as well as a more inexpensive substitute, nickel. This is the first anode material study done using the most sustainably designed microsized MFC to date, which utilizes ambient oxygen as the electron acceptor with an air cathode instead of the chemical ferricyanide and without a membrane. Ferricyanide is unsustainable, as the chemical must be continuously refilled, while using oxygen, naturally found in air, makes the device mobile and is a key step in commercializing this for portable technology such as lab-on-a-chip for point-of-care diagnostics. At 880 mA/m(2) and 19 mW/m(2) the MWCNT anode outperformed the others in both current and power densities with between 6 and 20 times better performance. All devices were run for over 15 days, indicating a stable and high-endurance energy harvester already capable of producing enough power for ultra-low-power electronics and able to consistently power them over time. PMID:23899322

  18. Nanoparticle Cookies Derived from Metal-Organic Frameworks: Controlled Synthesis and Application in Anode Materials for Lithium-Ion Batteries.

    PubMed

    Wang, Shuhai; Chen, Minqi; Xie, Yanyu; Fan, Yanan; Wang, Dawei; Jiang, Ji-Jun; Li, Yongguang; Grützmacher, Hansjörg; Su, Cheng-Yong

    2016-05-01

    The capacity of anode materials plays a critical role in the performance of lithium-ion batteries. Using the nanocrystals of oxygen-free metal-organic framework ZIF-67 as precursor, a one-step calcination approach toward the controlled synthesis of CoO nanoparticle cookies with excellent anodic performances is developed in this work. The CoO nanoparticle cookies feature highly porous structure composed of small CoO nanoparticles (≈12 nm in diameter) and nitrogen-rich graphitic carbon matrix (≈18 at% in nitrogen content). Benefiting from such unique structure, the CoO nanoparticle cookies are capable of delivering superior specific capacity and cycling stability (1383 mA h g(-1) after 200 runs at 100 mA g(-1) ) over those of CoO and graphite. PMID:26948965

  19. High-capacity carbon-coated titanium dioxide core-shell nanoparticles modified three dimensional anodes for improved energy output in microbial fuel cells

    NASA Astrophysics Data System (ADS)

    Tang, Jiahuan; Yuan, Yong; Liu, Ting; Zhou, Shungui

    2015-01-01

    Three-dimensional (3D) electrodes have been intensively investigated as alternatives to conventional plate electrodes in the development of high-performance microbial fuel cells (MFCs). However, the energy output of the MFCs with the 3D anodes is still limited for practical applications. In this study, a 3D anode modified with a nano-structured capacitive layer is prepared to improve the performance of an microbial fuel cell (MFC). The capacitive layer composes of titanium dioxide (TiO2) and egg white protein (EWP)-derived carbon assembled core-shell nanoparticles, which are integrated into loofah sponge carbon (LSC) to obtain a high-capacitive 3D electrode. The as-prepared 3D anode produces a power density of 2.59 ± 0.12 W m-2, which is 63% and 201% higher than that of the original LSC and graphite anodes, respectively. The increased energy output is contributed to the enhanced electrochemical capacitance of the 3D anodes as well as the synergetic effects between TiO2 and EWP-derived carbon due to their unique properties, such as relatively high surface area, good biocompatibility, and favorable surface functionalization for interfacial microbial electron transfer. The results obtained in this study will benefit the optimized design of new 3D materials to achieve enhanced performance in MFCs.

  20. Effects of Surface Oxygen on the Performance of Carbon as an Anode in Lithium-Ion Batteries

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh; Clark, Gregory W.

    2001-01-01

    Carbon materials with similar bulk structure but different surface oxygen were compared for their performance as anodes in lithium-ion battery. The bulk structure was such that the graphene planes were perpendicular to the surface. Three types of surfaces were examined: surface containing C=O type oxygen. surface containing -O-C type oxygen, and surface containing high concentration of active sites. The test involved cycles of lithium insertion into and release from the carbon materials, which was in the half cells of carbon/saturated LiI-50/50 (vol %) EC and DMC/lithium. During the first cycle of lithium insertion, the presence of adsorbed oxygen, -O-C type oxygen, active carbon sites, and C=O type oxygen resulted in the formation of solid-electrolyte interface (SEI) when the carbon's voltage relative to lithium metal was >1.35, 1 to 1.35, 0.5 to 1, and 0.67 to 0.7 V, respectively. An optimum -O-C type oxygen and a minimum C=O type oxygen was found to increase the reversible and decrease the irreversible capacity of carbon. Active sites on the carbon surface result in a large irreversible capacity and a second lithium insertion-release mechanism. However, this new mechanism has a short cycle life.

  1. In situ growth of carbon nanotube wrapped Si composites as anodes for high performance lithium ion batteries.

    PubMed

    Zhou, Jianbin; Lan, Yang; Zhang, Kailong; Xia, Guoliang; Du, Jin; Zhu, Yongchun; Qian, Yitai

    2016-03-01

    The composites of carbon nanotube wrapped Si particles (CNTWS) were synthesized in situ by using the catalytic chemical vapor deposition (CCVD) method. In this process, carbon nanotubes were produced in situ to wrap Si by the catalysis action of nascent Cu* under an acetylene atmosphere at a relatively low temperature of 400 °C, in which nascent Cu* was created by the reaction between Si particles and CuCl synchronously. The weight ratio of Si/C in CNTWS is 0.76/0.24. As anode materials for lithium ion batteries, the CNTWS composites exhibit a reversible discharge capacity of 1031.1 mA h g(-1) at 1.8 A g(-1) after 500 cycles, and 868.2 mA h g(-1) at 10.0 A g(-1). The high electrochemical performance of CNTWS composites is associated with the in situ formed carbon nanotubes. PMID:26875542

  2. Study of tin-sulphur-carbon nanocomposites based on electrically exploded tin as anode for sodium battery

    NASA Astrophysics Data System (ADS)

    Pervez, S. A.; Kim, D.; Lee, S.-M.; Doh, C.-H.; Lee, S.; Farooq, U.; Saleem, M.

    2016-05-01

    An electrochemical study of tin-sulphur-carbon nano-composites, based on electrically exploded tin-carbon nanoparticles as anode for sodium-ion battery (NIB), is carried out in electrolytes with and without fluoroethylene carbonate (FEC). The composites are synthesized through high energy mechanical milling (HEMM) of electrical exploded tin, sulphur nanoparticles and grinded carbon. The final product consists of tin sulfide nanoparticles embedded in amorphous carbon matrix. The results demonstrate an excellent response for the electrode materials in terms of initial discharge capacity (>425 mAhg-1) and cyclic performance (415 mAhg-1 after 50 cycles). Even more remarkably, at high current densities of 400, 600, and 800 mAg-1, electrodes still offer specific capacities of about 375, 355, and 315 mAhg-1, respectively, suggesting good rate capability of the materials. Furthermore, it is observed that the material response is much better when electrolyte has FEC as an additive which helped in the formation of an optimized SEI layer. Such an improved electrochemical performance of the electrode materials highlights their suitability for the recently emerging Na-ion battery technology.

  3. Assessing the improved performance of freestanding, flexible graphene and carbon nanotube hybrid foams for lithium ion battery anodes

    NASA Astrophysics Data System (ADS)

    Cohn, Adam P.; Oakes, Landon; Carter, Rachel; Chatterjee, Shahana; Westover, Andrew S.; Share, Keith; Pint, Cary L.

    2014-04-01

    We demonstrate the fabrication of three-dimensional freestanding foams of hybrid graphene-single-walled carbon nanotube nanomanufactured materials with reversible capacities of 2640 mA h g-1 at 0.186 A g-1 and 236 mA h g-1 at 27.9 A g-1. The Li storage behavior of this material is compared against other nanostructures in similar flexible foam platforms including graphene, ultra-thin graphite, and single-walled carbon nanotubes (SWNTs), and we elucidate the improved hybrid material performance due to the decoupling of lithium storage reaction energetics dictated by the SWNTs from the total storage capacity of the hybrid material. This work demonstrates a route to develop mechanically robust all-carbon electrodes with the potential for reversible Li-ion storage capacity approaching silicon, power capability of the best supercapacitors, and based on a material simultaneously usable as a charge collector and anode.We demonstrate the fabrication of three-dimensional freestanding foams of hybrid graphene-single-walled carbon nanotube nanomanufactured materials with reversible capacities of 2640 mA h g-1 at 0.186 A g-1 and 236 mA h g-1 at 27.9 A g-1. The Li storage behavior of this material is compared against other nanostructures in similar flexible foam platforms including graphene, ultra-thin graphite, and single-walled carbon nanotubes (SWNTs), and we elucidate the improved hybrid material performance due to the decoupling of lithium storage reaction energetics dictated by the SWNTs from the total storage capacity of the hybrid material. This work demonstrates a route to develop mechanically robust all-carbon electrodes with the potential for reversible Li-ion storage capacity approaching silicon, power capability of the best supercapacitors, and based on a material simultaneously usable as a charge collector and anode. Electronic supplementary information (ESI) available: ESI is available that includes (i) SEM and photographs of ultra-thin graphite foams, (ii) Raman

  4. In situ growth of carbon nanotube wrapped Si composites as anodes for high performance lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zhou, Jianbin; Lan, Yang; Zhang, Kailong; Xia, Guoliang; Du, Jin; Zhu, Yongchun; Qian, Yitai

    2016-02-01

    The composites of carbon nanotube wrapped Si particles (CNTWS) were synthesized in situ by using the catalytic chemical vapor deposition (CCVD) method. In this process, carbon nanotubes were produced in situ to wrap Si by the catalysis action of nascent Cu* under an acetylene atmosphere at a relatively low temperature of 400 °C, in which nascent Cu* was created by the reaction between Si particles and CuCl synchronously. The weight ratio of Si/C in CNTWS is 0.76/0.24. As anode materials for lithium ion batteries, the CNTWS composites exhibit a reversible discharge capacity of 1031.1 mA h g-1 at 1.8 A g-1 after 500 cycles, and 868.2 mA h g-1 at 10.0 A g-1. The high electrochemical performance of CNTWS composites is associated with the in situ formed carbon nanotubes.The composites of carbon nanotube wrapped Si particles (CNTWS) were synthesized in situ by using the catalytic chemical vapor deposition (CCVD) method. In this process, carbon nanotubes were produced in situ to wrap Si by the catalysis action of nascent Cu* under an acetylene atmosphere at a relatively low temperature of 400 °C, in which nascent Cu* was created by the reaction between Si particles and CuCl synchronously. The weight ratio of Si/C in CNTWS is 0.76/0.24. As anode materials for lithium ion batteries, the CNTWS composites exhibit a reversible discharge capacity of 1031.1 mA h g-1 at 1.8 A g-1 after 500 cycles, and 868.2 mA h g-1 at 10.0 A g-1. The high electrochemical performance of CNTWS composites is associated with the in situ formed carbon nanotubes. Electronic supplementary information (ESI) available. See DOI: 10.1039/c5nr08961a

  5. Nitrogen-Doped Carbon Embedded MoS2 Microspheres as Advanced Anodes for Lithium- and Sodium-Ion Batteries.

    PubMed

    Xie, Dong; Xia, Xinhui; Wang, Yadong; Wang, Donghuang; Zhong, Yu; Tang, Wangjia; Wang, Xiuli; Tu, Jiangping

    2016-08-01

    Rational design and synthesis of advanced anode materials are extremely important for high-performance lithium-ion and sodium-ion batteries. Herein, a simple one-step hydrothermal method is developed for fabrication of N-C@MoS2 microspheres with the help of polyurethane as carbon and nitrogen sources. The MoS2 microspheres are composed of MoS2 nanoflakes, which are wrapped by an N-doped carbon layer. Owing to its unique structural features, the N-C@MoS2 microspheres exhibit greatly enhanced lithium- and sodium-storage performances including a high specific capacity, high rate capability, and excellent capacity retention. Additionally, the developed polyurethane-assisted hydrothermal method could be useful for the construction of many other high-capacity metal oxide/sulfide composite electrode materials for energy storage. PMID:27355199

  6. Well-constructed silicon-based materials as high-performance lithium-ion battery anodes.

    PubMed

    Liu, Lehao; Lyu, Jing; Li, Tiehu; Zhao, Tingkai

    2016-01-14

    Silicon has been considered as one of the most promising anode material alternates for next-generation lithium-ion batteries, because of its high theoretical capacity, environmental friendliness, high safety, low cost, etc. Nevertheless, silicon-based anode materials (especially bulk silicon) suffer from severe capacity fading resulting from their low intrinsic electrical conductivity and great volume variation during lithiation/delithiation processes. To address this challenge, a few special constructions from nanostructures to anchored, flexible, sandwich, core-shell, porous and even integrated structures, have been well designed and fabricated to effectively improve the cycling performance of silicon-based anodes. In view of the fast development of silicon-based anode materials, we summarize their recent progress in structural design principles, preparation methods, morphological characteristics and electrochemical performance by highlighting the material structure. We also point out the associated problems and challenges faced by these anodes and introduce some feasible strategies to further boost their electrochemical performance. Furthermore, we give a few suggestions relating to the developing trends to better mature their practical applications in next-generation lithium-ion batteries. PMID:26666682

  7. Well-constructed silicon-based materials as high-performance lithium-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Liu, Lehao; Lyu, Jing; Li, Tiehu; Zhao, Tingkai

    2015-12-01

    Silicon has been considered as one of the most promising anode material alternates for next-generation lithium-ion batteries, because of its high theoretical capacity, environmental friendliness, high safety, low cost, etc. Nevertheless, silicon-based anode materials (especially bulk silicon) suffer from severe capacity fading resulting from their low intrinsic electrical conductivity and great volume variation during lithiation/delithiation processes. To address this challenge, a few special constructions from nanostructures to anchored, flexible, sandwich, core-shell, porous and even integrated structures, have been well designed and fabricated to effectively improve the cycling performance of silicon-based anodes. In view of the fast development of silicon-based anode materials, we summarize their recent progress in structural design principles, preparation methods, morphological characteristics and electrochemical performance by highlighting the material structure. We also point out the associated problems and challenges faced by these anodes and introduce some feasible strategies to further boost their electrochemical performance. Furthermore, we give a few suggestions relating to the developing trends to better mature their practical applications in next-generation lithium-ion batteries.

  8. Functional Carbon Materials for Electrochemical Energy Storage

    NASA Astrophysics Data System (ADS)

    Zhou, Huihui

    create uniformly distributed nanopores with large surface area, leading to high-performance electrodes with high capacitance, excellent rate performance and stable cycling, even under a high working voltage of 1.6V. The second part of this dissertation work further improved the capacitance of the carbon electrodes by fluorine doping. This doping process enhances the affinity of the carbon surface with organic electrolytes, leading to further improved capacitance and energy density. In the third part, carbon materials were synthesized with high surface area, capacitance and working voltage of 4V in organic electrolyte, leading to the construction of prototyped devices with energy density comparable to those of the current lead-acid batteries. Besides the abovementioned research, hierarchical graphitic carbons were also explored for lithium ion batteries and supercapacitors. Overall, through rational design of carbons with optimized pore configuration and surface chemistry, carbon electrodes with improved energy density and rate performance were improved significantly. Collectively, this thesis work systematically unveils simple yet effective strategies to achieve high performance carbon-based supercapacitors with high power density and high energy density, including the following aspects: 1) Constructed electrodes with high capacitance through building favorable ion/electron transportation pathways, tuning pore structure and pore size. 2) Improved the capacitance through enhancing the affinity between the carbon electrodes and electrolytes by doping the carbons with heteroatoms. 3) Explored and understand the roles of heteroatom doping in the capacitive behavior by both experimental measurement and computational modeling. 4) Improved energy density of carbon electrodes by enlarging their working voltage in aqueous and organic electrolyte. 5) Scalable and effective production of hierarchically porous graphite particles through aerosol process for use as the anode materials

  9. Sulfur tolerant anode materials. Quarterly report, October 1--December 31, 1986

    SciTech Connect

    Not Available

    1987-02-01

    The goal of this program is the development of a molten carbonate fuel cell (MCFC) anode which is more tolerant of sulfur contaminants in the fuel than the current state-of-the-art nickel-based anode structures. This program addresses two different but related aspects of the sulfur contamination problem. The primary aspect is concerned with the development of a sulfur tolerant electrocatalyst for the fuel oxidation reaction. A secondary issue is the development of a sulfur tolerant water-gas-shift reaction catalyst and an investigation of potential steam reforming catalysts which also have some sulfur tolerant capabilities. These two aspects are being addressed as two separate tasks.

  10. Titania-carbon nanocomposite anodes for lithium ion batteries--effects of confined growth and phase synergism.

    PubMed

    Petkovich, Nicholas D; Wilson, Benjamin E; Rudisill, Stephen G; Stein, Andreas

    2014-10-22

    As lithium-ion batteries (LIB) see increasing use in areas beyond consumer electronics, such as the transportation sector, research has been directed at improving LIBs to better suit these applications. Of particular interest are materials and methods to increase Li(+) capacity at various charge/discharge rates, to improve retention of Li(+) capacity from cycle-to-cycle, and to enhance various safety aspects of electrode synthesis, cell construction, and end use. This work focuses on the synthesis and testing of three-dimensionally ordered macroporous (3DOM) TiO2/C LIB anode materials prepared using low toxicity precursors, including ammonium citratoperoxotitanate(IV) and sucrose, which provide high capacities for reversible Li(+) insertion/extraction. When the composites are pyrolyzed at 700 °C, the carbon phase restricts sintering of TiO2 crystallites and keeps the size of these crystallites below 5 nm. Slightly larger crystallites are produced at higher temperatures, alongside a titanium oxycarbide phase. The composites exhibit excellent capacities as LIB anodes at low to moderate charge/discharge rates (in the window from 1 to 3 V vs Li/Li(+)). Composites pyrolyzed at 700 °C retain over 200 mAh/g TiO2 of capacity after 100 cycles at a C/2 rate (C = 335 mA/g), and do not suffer from extensive cycle-to-cycle capacity fading. A substantial improvement of overall capacities, especially at high rates, is attained by cycling the composite anodes in a wider voltage window (0.05 to 3 V vs Li/Li(+)), which allows for Li(+) intercalation into carbon. At currents of 1500 mA/g of active material, over 200 mAh/g of capacity is retained. Other structural aspects of the composites are discussed, including how rutile TiO2 is found in these composites at sizes below the thermodynamic stability limit in the pure phase. PMID:25249184

  11. Synthesis and Electrochemical Properties of CNFs-Si Composites as an Anode Material for Li Secondary Batteries.

    PubMed

    Park, Eun-Sil; Park, Heai-Ku; Park, Ho-Seon; Lee, Chang-Seop

    2015-11-01

    We have performed a study on the electrochemical and structural characteristics of CNFs-Si composites which are active anode material for lithium secondary batteries. Carbon nanofibers (CNFs) have been synthesized by Chemical Vapor Deposition (CVD) using Co and Cu catalysts. The CNFs on the surface of the Si particle can provide a flexible space to relieve the volumetric expansion during a charge. Therefore, the CNFs composites on Si particles were prepared on the basis of the following two processes: (1) CNFs were grown on the simple mechanical mixture of Si particles and catalysts (CNFs/Si); (2) CNFs were grown on the surface of a pyrolytic carbon that was coated with Si particles (CNFs/PC/Si). The morphology and composition of CNFs-Si composites were analyzed by SEM and EDS measurements. Crystallinity and amorphicity were investigated using XRD and Raman spectroscopy. The characteristics of the synthesized CNFs-Si composites were analyzed through XPS, TGA, and BET. The two different CNFs-Si composite materials were evaluated as the anodic material in three different electrode cells. We found that the initial capacity of the CNFs/PC/Si composite electrode was 1,361 mAh/g with retention rate of 28.4%, which was better than the retention rate of 4.9% with the CNFs/Si electrode. PMID:26726626

  12. Lignin-based active anode materials synthesized from low-cost renewable resources

    DOEpatents

    Rios, Orlando; Tenhaeff, Wyatt Evan; Daniel, Claus; Dudney, Nancy Johnston; Johs, Alexander; Nunnery, Grady Alexander; Baker, Frederick Stanley

    2016-06-07

    A method of making an anode includes the steps of providing fibers from a carbonaceous precursor, the carbon fibers having a glass transition temperature T.sub.g. In one aspect the carbonaceous precursor is lignin. The carbonaceous fibers are placed into a layered fiber mat. The fiber mat is fused by heating the fiber mat in the presence of oxygen to above the T.sub.g but no more than 20% above the T.sub.g to fuse fibers together at fiber to fiber contact points and without melting the bulk fiber mat to create a fused fiber mat through oxidative stabilization. The fused fiber mat is carbonized by heating the fused fiber mat to at least 650.degree. C. under an inert atmosphere to create a carbonized fused fiber mat. A battery anode formed from carbonaceous precursor fibers is also disclosed.

  13. Graphdiyne as a high-capacity lithium ion battery anode material

    NASA Astrophysics Data System (ADS)

    Jang, Byungryul; Koo, Jahyun; Park, Minwoo; Lee, Hosik; Nam, Jaewook; Kwon, Yongkyung; Lee, Hoonkyung

    2013-12-01

    Using the first-principles calculations, we explored the feasibility of using graphdiyne, a 2D layer of sp and sp2 hybrid carbon networks, as lithium ion battery anodes. We found that the composite of the Li-intercalated multilayer α-graphdiyne was C6Li7.31 and that the calculated voltage was suitable for the anode. The practical specific/volumetric capacities can reach up to 2719 mAh g-1/2032 mAh cm-3, much greater than the values of ˜372 mAh g-1/˜818 mAh cm-3, ˜1117 mAh g-1/˜1589 mAh cm-3, and ˜744 mAh g-1 for graphite, graphynes, and γ-graphdiyne, respectively. Our calculations suggest that multilayer α-graphdiyne can serve as a promising high-capacity lithium ion battery anode.

  14. The influence of carbon support porosity on the activity of PtRu/Sibunit anode catalysts for methanol oxidation

    NASA Astrophysics Data System (ADS)

    Rao, V.; Simonov, P. A.; Savinova, E. R.; Plaksin, G. V.; Cherepanova, S. V.; Kryukova, G. N.; Stimming, U.

    In this paper we analyse the promises of homemade carbon materials of Sibunit family prepared through pyrolysis of natural gases on carbon black surfaces as supports for the anode catalysts of direct methanol fuel cells. Specific surface area ( SBET) of the support is varied in the wide range from 6 to 415 m 2 g -1 and the implications on the electrocatalytic activity are scrutinized. Sibunit supported PtRu (1:1) catalysts are prepared via chemical route and the preparation conditions are adjusted in such a way that the particle size is constant within ±1 nm in order to separate the influence of support on the (i) catalyst preparation and (ii) fuel cell performance. Comparison of the metal surface area measured by gas phase CO chemisorption and electrochemical CO stripping indicates close to 100% utilisation of nanoparticle surfaces for catalysts supported on low (22-72 m 2 g -1) surface area Sibunit carbons. Mass activity and specific activity of PtRu anode catalysts change dramatically with SBET of the support, increasing with the decrease of the latter. 10%PtRu catalyst supported on Sibunit with specific surface area of 72 m 2 g -1 shows mass specific activity exceeding that of commercial 20%PtRu/Vulcan XC-72 by nearly a factor of 3.

  15. Fabrication of carbon microcapsules containing silicon nanoparticles-carbon nanotubes nanocomposite by sol-gel method for anode in lithium ion battery

    NASA Astrophysics Data System (ADS)

    Bae, Joonwon

    2011-07-01

    Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT@C) have been fabricated by a surfactant mediated sol-gel method followed by a carbonization process. Silicon nanoparticles-carbon nanotubes (Si-CNT) nanohybrids were produced by a wet-type beadsmill method. To obtain Si-CNT nanocomposites with spherical morphologies, a silica precursor (tetraethylorthosilicate, TEOS) and polymer (PMMA) mixture was employed as a structure-directing medium. Thus the Si-CNT/Silica-Polymer microspheres were prepared by an acid catalyzed sol-gel method. Then a carbon precursor such as polypyrrole (PPy) was incorporated onto the surfaces of pre-existing Si-CNT/silica-polymer to generate Si-CNT/Silica-Polymer@PPy microspheres. Subsequent thermal treatment of the precursor followed by wet etching of silica produced Si-CNT@C microcapsules. The intermediate silica/polymer must disappear during the carbonization and etching process resulting in the formation of an internal free space. The carbon precursor polymer should transform to carbon shell to encapsulate remaining Si-CNT nanocomposites. Therefore, hollow carbon microcapsules containing Si-CNT nanocomposites could be obtained (Si-CNT@C). The successful fabrication was confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). These final materials were employed for anode performance improvement in lithium ion battery. The cyclic performances of these Si-CNT@C microcapsules were measured with a lithium battery half cell tests.

  16. Three-dimensional SnO2/carbon on Cu foam for high-performance lithium ion battery anodes.

    PubMed

    Chen, Weimin; Maloney, Scott; Wang, Wenyong

    2016-10-14

    SnO2 is an attractive anode material for lithium-ion batteries (LIBs) due to its high theoretical specific capacity (1491 mAh g(-1)), low cost, and environmental benignity. The main challenges for SnO2 anodes are their low intrinsic conductivity and poor cycling stability associated with their large volume changes during the charge and discharge process. Here, we present a simple chemical vapor deposition method to fabricate three-dimensional SnO2/carbon on Cu foam electrodes for LIBs. Such a three-dimensional electrode combines multiple advantages, including a continuous electrically conductive network, short pathways for electron transport and ion diffusion, and porous space to allow for the volume expansion of SnO2 nanoparticles. With this anode, superior electrochemical performance is achieved with a high reversible specific capacity of 1171 mAh g(-1) at a current density of 100 mA g(-1). A stable cycling performance as well as an excellent rate capability is also achieved. These outstanding lithium-storage properties suggest the strategy is a reliable approach for fabricating high-performance LIB electrodes. PMID:27587237

  17. Bundled and densified carbon nanotubes (CNT) fabrics as flexible ultra-light weight Li-ion battery anode current collectors

    NASA Astrophysics Data System (ADS)

    Yehezkel, Shani; Auinat, Mahmud; Sezin, Nina; Starosvetsky, David; Ein-Eli, Yair

    2016-04-01

    Carbon nanotubes (CNT) fabrics were studied and evaluated as anode current collectors, replacing the traditional copper foil current collector in Li-ion batteries. Glavanostatic measurements reveal high values of irreversible capacities (as high as 28%), resulted mainly from the formation of the solid electrolyte interphase (SEI) layer at the CNT fabric surface. Various pre-treatments to the CNT fabric prior to active anode material loading have shown that the lowest irreversible capacity is achieved by immersing and washing the CNT fabric with iso-propanol (IPA), which dramatically modified the fabric surface. Additionally, the use of very thin CNT fabrics (5 μm) results in a substantial irreversible capacity minimization. A combination of IPA rinse action and utilization of the thinnest CNT fabric provides the lowest irreversible capacity of 13%. The paper describes innovative and rather simple techniques towards a complete implementation of CNT fabric as an anode current collector in Li-ion batteries, instead of the relatively heavy and expensive copper foil, enabling an improvement in the gravimetric and volumetric energy densities of such advanced batteries.

  18. Additive-free thick graphene film as an anode material for flexible lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Rana, Kuldeep; Kim, Seong Dae; Ahn, Jong-Hyun

    2015-04-01

    This work demonstrates a simple route to develop mechanically flexible electrodes for Li-ion batteries (LIBs) that are usable as lightweight effective conducting networks for both cathodes and anodes. Removing electrochemically dead elements, such as binders, conducting agents and metallic current collectors, from the battery components will allow remarkable progress in this area. To investigate the feasibility of using thick, additive-free graphene films as anodes for flexible LIBs, we have synthesized and tested thick, additive-free, freestanding graphene films as anodes, first in a coin cell and further in a flexible full cell. As an anode material in a half cell, it showed a discharge capacity of about 350 mA h g-1 and maintained nearly this capacity over 50 cycles at various current rates. This film was also tested as an anode material in a full cell with a LiCoO2 cathode and showed good electrochemical performance. Because the graphene-based flexible film showed good performance in half- and full coin cells, we used this film as a flexible anode for flexible LIBs. No conducting agent or binder was used in the anode side, which helped in realizing the flexible LIBs. Using this, we demonstrate a thin, lightweight and flexible lithium ion battery with good electrochemical performance in both its flat and bent states.This work demonstrates a simple route to develop mechanically flexible electrodes for Li-ion batteries (LIBs) that are usable as lightweight effective conducting networks for both cathodes and anodes. Removing electrochemically dead elements, such as binders, conducting agents and metallic current collectors, from the battery components will allow remarkable progress in this area. To investigate the feasibility of using thick, additive-free graphene films as anodes for flexible LIBs, we have synthesized and tested thick, additive-free, freestanding graphene films as anodes, first in a coin cell and further in a flexible full cell. As an anode

  19. Bioinspired Carbon/SnO2 Composite Anodes Prepared from a Photonic Hierarchical Structure for Lithium Batteries.

    PubMed

    Li, Yao; Meng, Qing; Ma, Jun; Zhu, Chengling; Cui, Jingru; Chen, Zhixin; Guo, Zaiping; Zhang, Tao; Zhu, Shenmin; Zhang, Di

    2015-06-01

    A carbon/SnO2 composite (C-SnO2) with hierarchical photonic structure was fabricated from the templates of butterfly wings. We have investigated for the first time its application as the anode material for lithium-ion batteries. It was demonstrated to have high reversible capacities, good cycling stability, and excellent high-rate discharge performance, as shown by a capacitance of ∼572 mAh g(-1) after 100 cycles, 4.18 times that of commercial SnO2 powder (137 mAh g(-1)); a far better recovery capability of 94.3% was observed after a step-increase and sudden-recovery current. An obvious synergistic effect was found between the porous, hierarchically photonic microstructure and the presence of carbon; the synergy guarantees an effective flow of electrolyte and a short diffusion length of lithium ions, provides considerable buffering room, and prevents aggregation of SnO2 particles in the discharge/charge processes. This nature-inspired strategy points out a new direction for the fabrication of alternative anode materials. PMID:25939407

  20. Hierarchical porous nitrogen-doped carbon nanosheets derived from silk for ultrahigh-capacity battery anodes and supercapacitors.

    PubMed

    Hou, Jianhua; Cao, Chuanbao; Idrees, Faryal; Ma, Xilan

    2015-03-24

    Hierarchical porous nitrogen-doped carbon (HPNC) nanosheets (NS) have been prepared via simultaneous activation and graphitization of biomass-derived natural silk. The as-obtained HPNC-NS show favorable features for electrochemical energy storage such as high specific surface area (SBET: 2494 m(2)/g), high volume of hierarchical pores (2.28 cm(3)/g), nanosheet structures, rich N-doping (4.7%), and defects. With respect to the multiple synergistic effects of these features, a lithium-ion battery anode and a two-electrode-based supercapacitor have been prepared. A reversible lithium storage capacity of 1865 mA h/g has been reported, which is the highest for N-doped carbon anode materials to the best of our knowledge. The HPNC-NS supercapacitor's electrode in ionic liquid electrolytes exhibit a capacitance of 242 F/g and energy density of 102 W h/kg (48 W h/L), with high cycling life stability (9% loss after 10,000 cycles). Thus, a high-performance Li-ion battery and supercapacitors were successfully assembled for the same electrode material, which was obtained through a one-step and facile large-scale synthesis route. It is promising for next-generation hybrid energy storage and renewable delivery devices. PMID:25703427

  1. Physical separation of carbon and bath constituents of spent anode residues

    SciTech Connect

    Plumpton, A.J.; Cotnoir, D.

    1996-10-01

    The constituent mineral and metallic phases contained within certain waste products and by-products of aluminum smelting are observed to be sufficiently liberated, permitting their separation and recovery using physical techniques. CRM studied both dry and wet mineral processing methods for the recovery of pure carbon and so-called bath products from spent anode shot-peening wastes. The experiments were undertaken on composite samples of fine and coarse residues, combined in proportion to their production rates. The composite samples analyzed 30% C and 70% electrolysis bath (cryolite, alumina, aluminum fluoride) and possessed an average particle size of 143 {micro}m with a 16 weight % {minus}45 {micro}m fraction. Test results are presented for two dry processing methods of high tension/electrostatic separation and pneumatic tabling, as well as two wet methods of gravity tabling and froth flotation. Each wet mineral separation method yielded two clean products following a limited number of cleaning and scavenging operations; one product graded 95 to 98% C, the other, 97 to 99% bath. Although similar high purity products could be obtained using dry separation approaches, their yields were significantly lower and the feed material required desliming or division into narrow particle size fractions prior to separation. After dry processing including multiple scavenging and cleaning steps, an important middling fraction remained, corresponding to about 40--50 weight % of the feed. Predesign cost estimation was undertaken for the most efficient processing scheme.

  2. Si nanoparticles encapsulated in elastic hollow carbon fibres for Li-ion battery anodes with high structural stability.

    PubMed

    Fang, Shan; Shen, Laifa; Tong, Zhenkun; Zheng, Hao; Zhang, Fang; Zhang, Xiaogang

    2015-04-28

    Silicon has a large specific capacity which is an order of magnitude beyond that of conventional graphite, making it a promising anode material for lithium ion batteries. However, the large volume changes (∼ 300%) during cycling caused material pulverization and instability of the solid-electrolyte interphase resulting in poor cyclability which prevented its commercial application. Here, we have prepared a novel one-dimensional core-shell nanostructure in which the Si nanoparticles have been confined within hollow carbon nanofibres. Such a unique nanostructure exhibits high conductivity and facile ion transport, and the uniform pores within the particles which are generated during magnesiothermic reduction can serve as a buffer zone to accommodate the large volume changes of Si during electrochemical lithiation. Owing to these advantages, the composite shows high rate performance and good cycling stability. The optimum design of the core-shell nanostructure shows promise for the synthesis of a variety of high-performance electrode materials. PMID:25826238

  3. Synthesis, Characterization and Testing of Novel Anode and Cathode Materials for Li-Ion Batteries

    SciTech Connect

    White, Ralph E.; Popov, Branko N.

    2002-10-31

    During this program we have synthesized and characterized several novel cathode and anode materials for application in Li-ion batteries. Novel synthesis routes like chemical doping, electroless deposition and sol-gel method have been used and techniques like impedance, cyclic voltammetry and charge-discharge cycling have been used to characterize these materials. Mathematical models have also been developed to fit the experimental result, thus helping in understanding the mechanisms of these materials.

  4. Efficient 3D conducting networks built by graphene sheets and carbon nanoparticles for high-performance silicon anode.

    PubMed

    Zhou, Xiaosi; Yin, Ya-Xia; Cao, An-Min; Wan, Li-Jun; Guo, Yu-Guo

    2012-05-01

    The utilization of silicon particles as anode materials for lithium-ion batteries is hindered by their low intrinsic electric conductivity and large volume changes during cycling. Here we report a novel Si nanoparticle-carbon nanoparticle/graphene composite, in which the addition of carbon nanoparticles can effectively alleviate the aggregation of Si nanoparticles by separating them from each other, and help graphene sheets build efficient 3D conducting networks for Si nanoparticles. Such Si-C/G composite shows much improved electrochemical properties in terms of specific capacity and cycling performance (ca. 1521 mA h g(-1) at 0.2 C after 200 cycles), as well as a favorable high-rate capability. PMID:22563769

  5. Octahedral core–shell cuprous oxide/carbon with enhanced electrochemical activity and stability as anode for lithium ion batteries

    SciTech Connect

    Xiang, Jiayuan; Chen, Zhewei; Wang, Jianming

    2015-10-15

    Highlights: • Core–shell octahedral Cu{sub 2}O/C is prepared by a one-step method. • Carbon shell is amorphous and uniformly decorated at the Cu{sub 2}O octahedral core. • Core–shell Cu{sub 2}O/C exhibits markedly enhanced capability and reversibility. • Carbon shell provides fast ion/electron transfer channel. • Core–shell structure is stable during cycling. - Abstract: Core–shell Cu{sub 2}O/C octahedrons are synthesized by a simple hydrothermal method with the help of carbonization of glucose, which reduces Cu(II) to Cu(I) at low temperature and further forms carbon shell coating at high temperature. SEM and TEM images indicate that the carbon shell is amorphous with thickness of ∼20 nm wrapping the Cu{sub 2}O octahedral core perfectly. As anode of lithium ion batteries, the core–shell Cu{sub 2}O/C composite exhibits high and stable columbic efficiency (98%) as well as a reversible capacity of 400 mAh g{sup −1} after 80 cycles. The improved electrochemical performance is attributed to the novel core–shell structure, in which the carbon shell reduces the electrode polarization and promotes the charge transfer at active material/electrolyte interface, and also acts as a stabilizer to keep the octahedral structure integrity during discharge–charge processes.

  6. Effect of the electric field of the anode sheath on the growth of aligned carbon nanotubes in a glow discharge

    SciTech Connect

    Pal', A. F.; Rakhimova, T. V.; Suetin, N. V.; Timofeev, M. A.; Filippov, A. V.

    2007-01-15

    Arrays of aligned carbon nanotubes on silicon substrates were grown in the anode sheath of a dc glow discharge. In order to clarify the role of the electric field in the growth of nanotubes, numerical simulations of charged particle transport in the anode sheath were carried out in the drift-diffusion approximation. The distributions of the charged particle density and electric field are obtained. Possible mechanisms whereby the electric field influences the growth of aligned carbon nanotubes are analyzed. It is found that the nanotubes grow in the region in which the electric field is enhanced due to the depletion of positive ions in the anode sheath.

  7. Hierarchical silicon nanowires-carbon textiles matrix as a binder-free anode for high-performance advanced lithium-ion batteries.

    PubMed

    Liu, Bin; Wang, Xianfu; Chen, Haitian; Wang, Zhuoran; Chen, Di; Cheng, Yi-Bing; Zhou, Chongwu; Shen, Guozhen

    2013-01-01

    Toward the increasing demands of portable energy storage and electric vehicle applications, the widely used graphite anodes with significant drawbacks become more and more unsuitable. Herein, we report a novel scaffold of hierarchical silicon nanowires-carbon textiles anodes fabricated via a facile method. Further, complete lithium-ion batteries based on Si and commercial LiCoO2 materials were assembled to investigate their corresponding across-the-aboard performances, demonstrating their enhanced specific capacity (2950 mAh g(-1) at 0.2 C), good repeatability/rate capability (even >900 mAh g(-1) at high rate of 5 C), long cycling life, and excellent stability in various external conditions (curvature, temperature, and humidity). Above results light the way to principally replacing graphite anodes with silicon-based electrodes which was confirmed to have better comprehensive performances. PMID:23572030

  8. Hierarchical silicon nanowires-carbon textiles matrix as a binder-free anode for high-performance advanced lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Liu, Bin; Wang, Xianfu; Chen, Haitian; Wang, Zhuoran; Chen, Di; Cheng, Yi-Bing; Zhou, Chongwu; Shen, Guozhen

    2013-04-01

    Toward the increasing demands of portable energy storage and electric vehicle applications, the widely used graphite anodes with significant drawbacks become more and more unsuitable. Herein, we report a novel scaffold of hierarchical silicon nanowires-carbon textiles anodes fabricated via a facile method. Further, complete lithium-ion batteries based on Si and commercial LiCoO2 materials were assembled to investigate their corresponding across-the-aboard performances, demonstrating their enhanced specific capacity (2950 mAh g-1 at 0.2 C), good repeatability/rate capability (even >900 mAh g-1 at high rate of 5 C), long cycling life, and excellent stability in various external conditions (curvature, temperature, and humidity). Above results light the way to principally replacing graphite anodes with silicon-based electrodes which was confirmed to have better comprehensive performances.

  9. Natural materials for carbon capture.

    SciTech Connect

    Myshakin, Evgeniy M.; Romanov, Vyacheslav N.; Cygan, Randall Timothy

    2010-11-01

    Naturally occurring clay minerals provide a distinctive material for carbon capture and carbon dioxide sequestration. Swelling clay minerals, such as the smectite variety, possess an aluminosilicate structure that is controlled by low-charge layers that readily expand to accommodate water molecules and, potentially, carbon dioxide. Recent experimental studies have demonstrated the efficacy of intercalating carbon dioxide in the interlayer of layered clays but little is known about the molecular mechanisms of the process and the extent of carbon capture as a function of clay charge and structure. A series of molecular dynamics simulations and vibrational analyses have been completed to assess the molecular interactions associated with incorporation of CO2 in the interlayer of montmorillonite clay and to help validate the models with experimental observation.

  10. Growth control of carbon nanotubes using by anodic aluminum oxide nano templates.

    PubMed

    Park, Yong Seob; Choi, Won Seek; Yi, Junsin; Lee, Jaehyeong

    2014-05-01

    Anodic Aluminum Oxide (AAO) template prepared in acid electrolyte possess regular and highly anisotropic porous structure with pore diameter range from five to several hundred nanometers, and with a density of pores ranging from 10(9) to 10(11) cm(-2). AAO can be used as microfilters and templates for the growth of CNTs and metal or semiconductor nanowires. Varying anodizing conditions such as temperature, electrolyte, applied voltage, anodizing and widening time, one can control the diameter, the length, and the density of pores. In this work, we deposited Al thin film by radio frequency magnetron sputtering method to fabricate AAO nano template and synthesized multi-well carbon nanotubes on a glass substrate by microwave plasma-enhanced chemical vapor deposition (MPECVD). AAO nano-porous templates with various pore sizes and depths were introduced to control the dimension and density of CNT arrays. The AAO nano template was synthesize on glass by two-step anodization technique. The average diameter and interpore distance of AAO nano template are about 65 nm and 82 nm. The pore density and AAO nano template thickness are about 2.1 x 10(10) pores/cm2 and 1 microm, respectively. Aligned CNTs on the AAO nano template were synthesized by MPECVD at 650 degrees C with the Ni catalyst layer. The length and diameter of CNTs were grown 2 microm and 50 nm, respectively. PMID:24734654

  11. Silicon-based materials as high capacity anodes for next generation lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Liang, Bo; Liu, Yanping; Xu, Yunhua

    2014-12-01

    Silicon (Si)-based materials have the highest capacity among the investigated anode materials and have been recognized as one of the most promising materials for lithium-ion batteries. However, it is still a significant challenge to obtain good performance for practical applications due to the huge volume change during the electrochemical process. To date, the most successful strategy is to introduce other components into Si to form composite or alloy materials. In this review, the recent progress in Si-based materials utilized in lithium-ion batteries is reviewed in terms of composite systems, nano-structure designs, material synthesis methods, and electrochemical performances. The merits and disadvantages of different Si-based materials, the understanding of the mechanisms behind the performance enhancement as well as the challenges faced in Si anodes are also discussed. We are trying to present a full scope of the Si-based materials, and help understand and design future structures of Si anodes in lithium-ion batteries.

  12. Evaluation of anode (electro)catalytic materials for the direct borohydride fuel cell: Methods and benchmarks

    NASA Astrophysics Data System (ADS)

    Olu, Pierre-Yves; Job, Nathalie; Chatenet, Marian

    2016-09-01

    In this paper, different methods are discussed for the evaluation of the potential of a given catalyst, in view of an application as a direct borohydride fuel cell DBFC anode material. Characterizations results in DBFC configuration are notably analyzed at the light of important experimental variables which influence the performances of the DBFC. However, in many practical DBFC-oriented studies, these various experimental variables prevent one to isolate the influence of the anode catalyst on the cell performances. Thus, the electrochemical three-electrode cell is a widely-employed and useful tool to isolate the DBFC anode catalyst and to investigate its electrocatalytic activity towards the borohydride oxidation reaction (BOR) in the absence of other limitations. This article reviews selected results for different types of catalysts in electrochemical cell containing a sodium borohydride alkaline electrolyte. In particular, propositions of common experimental conditions and benchmarks are given for practical evaluation of the electrocatalytic activity towards the BOR in three-electrode cell configuration. The major issue of gaseous hydrogen generation and escape upon DBFC operation is also addressed through a comprehensive review of various results depending on the anode composition. At last, preliminary concerns are raised about the stability of potential anode catalysts upon DBFC operation.

  13. Sulfur-tolerant redox-reversible anode material for direct hydrocarbon solid oxide fuel cells.

    PubMed

    Yang, Chenghao; Yang, Zhibin; Jin, Chao; Xiao, Guoliang; Chen, Fanglin; Han, Minfang

    2012-03-15

    A novel composite anode material consisting of K(2) NiF(4) -type structured Pr(0.8) Sr(1.2) (Co,Fe)(0.8) Nb(0.2) O(4+δ) (K-PSCFN) matrix with homogenously dispersed nano-sized Co-Fe alloy (CFA) has been obtained by annealing perovskite Pr(0.4) Sr(0.6) Co(0.2) Fe(0.7) Nb(0.1) O(3-δ) (P-PSCFN) in H(2) at 900 °C. The K-PSCFN-CFA composite anode is redox-reversible and has demonstrated similar catalytic activity to Ni-based cermet anode, excellent sulfur tolerance, remarkable coking resistance and robust redox cyclability. PMID:22318883

  14. Assessing carbon-based anodes for lithium-ion batteries: a universal description of charge-transfer binding.

    PubMed

    Liu, Yuanyue; Wang, Y Morris; Yakobson, Boris I; Wood, Brandon C

    2014-07-11

    Many key performance characteristics of carbon-based lithium-ion battery anodes are largely determined by the strength of binding between lithium (Li) and sp(2) carbon (C), which can vary significantly with subtle changes in substrate structure, chemistry, and morphology. Here, we use density functional theory calculations to investigate the interactions of Li with a wide variety of sp(2) C substrates, including pristine, defective, and strained graphene, planar C clusters, nanotubes, C edges, and multilayer stacks. In almost all cases, we find a universal linear relation between the Li-C binding energy and the work required to fill previously unoccupied electronic states within the substrate. This suggests that Li capacity is predominantly determined by two key factors-namely, intrinsic quantum capacitance limitations and the absolute placement of the Fermi level. This simple descriptor allows for straightforward prediction of the Li-C binding energy and related battery characteristics in candidate C materials based solely on the substrate electronic structure. It further suggests specific guidelines for designing more effective C-based anodes. The method should be broadly applicable to charge-transfer adsorption on planar substrates, and provides a phenomenological connection to established principles in supercapacitor and catalyst design. PMID:25062244

  15. Fabrication of carbon microcapsules containing silicon nanoparticles-carbon nanotubes nanocomposite by sol-gel method for anode in lithium ion battery

    SciTech Connect

    Bae, Joonwon

    2011-07-15

    Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT-C) have been fabricated by a surfactant mediated sol-gel method followed by a carbonization process. Silicon nanoparticles-carbon nanotubes (Si-CNT) nanohybrids were produced by a wet-type beadsmill method. To obtain Si-CNT nanocomposites with spherical morphologies, a silica precursor (tetraethylorthosilicate, TEOS) and polymer (PMMA) mixture was employed as a structure-directing medium. Thus the Si-CNT/Silica-Polymer microspheres were prepared by an acid catalyzed sol-gel method. Then a carbon precursor such as polypyrrole (PPy) was incorporated onto the surfaces of pre-existing Si-CNT/silica-polymer to generate Si-CNT/Silica-Polymer-PPy microspheres. Subsequent thermal treatment of the precursor followed by wet etching of silica produced Si-CNT-C microcapsules. The intermediate silica/polymer must disappear during the carbonization and etching process resulting in the formation of an internal free space. The carbon precursor polymer should transform to carbon shell to encapsulate remaining Si-CNT nanocomposites. Therefore, hollow carbon microcapsules containing Si-CNT nanocomposites could be obtained (Si-CNT-C). The successful fabrication was confirmed by scanning electron microscopy (SEM) and X-ray diffraction (XRD). These final materials were employed for anode performance improvement in lithium ion battery. The cyclic performances of these Si-CNT-C microcapsules were measured with a lithium battery half cell tests. - Graphical Abstract: Carbon microcapsules containing silicon nanoparticles (Si NPs)-carbon nanotubes (CNTs) nanocomposite (Si-CNT-C) have been fabricated by a surfactant mediated sol-gel method. Highlights: > Polymeric microcapsules containing Si-CNT transformed to carbon microcapsules. > Accommodate volume changes of Si NPs during Li ion charge/discharge. > Sizes of microcapsules were controlled by experimental parameters. > Lithium

  16. Facile synthesis of a MoO2-Mo2C-C composite and its application as favorable anode material for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Zhu, Yanping; Wang, Shaofeng; Zhong, Yijun; Cai, Rui; Li, Li; Shao, Zongping

    2016-03-01

    A composite of MoO2-Mo2C-C is fabricated through a facile ion-exchange route for the first time as an alternative anode material for lithium-ion batteries (LIBs). A macroporous cinnamic anion-exchange resin interacts with ammonium molybdate tetrahydrate in aqueous solution, and the product is then calcined under an inert gas atmosphere. The interaction between the resin and ammonium molybdate tetrahydrate results in an atomic level dispersion of the molybdenum over the organic carbon precursor (resin), while the calcination process allows the formation of MoO2 and Mo2C as well as the pyrolysis of resin to solid carbon. According to field-emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM) measurements, ultrafine MoO2 and Mo2C nanoparticles are uniformly dispersed but firmly attached within an amorphous carbon framework. When evaluated as an anode material, the as-synthesized sample exhibits superior electrochemical performance. The specific discharge capacity is as high as 1491 mA h g-1 in the first cycle and 724 mA h g-1 over 50 cycles at a current density of 0.2 A g-1. This simple, environmentally friendly, low-cost and easily scaled up method, has significant potential for mass industrial production of MoO2-based material as next-generation anode material of LIBs with wide application capability.

  17. In situ tem study on anode materials in lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Liang, Wentao

    The growing demand for light-weight, high-capacity lithium-ion batteries (LIBs) for portable electronics, plug-in hybrid electric vehicles, and stationary energy storage systems has led to intensive research on developing new electrode materials with higher energy density, higher power density, and longer lifetime. However, a major issue with the high-capacity materials such as silicon (Si) is the rapid, irreversible capacity decay and poor cyclability due to the lithiation/delithiation induced mechanical degradation. A fundamental understanding of coupled electro-chemo-mechanical effects on the lithiation/delithiation of anode materials in LIBs is critical important for the development of advanced LIBs. In this thesis, we constructed solid cell and liquid cell nanobatteries inside highresolution transmission electron microscopy (HRTEM) for electrochemical tests and mechanical degradation study of anode materials in LIBs. (Abstract shortened by UMI.).

  18. Anode regeneration following carbon depositions in an industrial-sized anode supported solid oxide fuel cell operating on synthetic diesel reformate

    NASA Astrophysics Data System (ADS)

    Subotić, Vanja; Schluckner, Christoph; Mathe, Jörg; Rechberger, Jürgen; Schroettner, Hartmuth; Hochenauer, Christoph

    2015-11-01

    Carbon deposition is a primary concern during operation of solid oxide fuel cells (SOFCs) fueled with carbon-containing fuels. It leads to cell degradation and thus reduces SOFC sustained operation and durability. This paper reports on an experimental investigation of carbon formation on the nickel/yttria-stabilized zirconia (Ni/YSZ) anode of an anode-supported SOFC and its regeneration. The cell was fueled with a synthetically produced diesel reformate to investigate and simulate the cell behavior under real operating conditions. For this purpose the cell was operated under load to determine the critical operating time. Rapid carbon generation, such as at open circuit voltage (OCV), can be prevented when the cell is under load. Carbon depositions were detected using scanning electron microscopy (SEM) and further analyzed by Raman spectroscopy. Industrial-size cells suitable for commercial applications were studied. This study proves the reversibility of carbon formation and the reproducibility of the regeneration process. It shows that carbon formations can be recognized and effectively, fully and cell-protecting regenerated. It indicates the excellent possibility of using SOFCs in the automotive industry as an auxiliary power unit (APU) or combined power-heat unit, operated with diesel reformate, without danger from cell degradation caused by carbon-containing fuels.

  19. Coaxial carbon/metal oxide/aligned carbon nanotube arrays as high-performance anodes for lithium ion batteries.

    PubMed

    Lou, Fengliu; Zhou, Haitao; Tran, Trung Dung; Melandsø Buan, Marthe Emelie; Vullum-Bruer, Fride; Rønning, Magnus; Walmsley, John Charles; Chen, De

    2014-05-01

    Coaxial carbon/metal oxide/aligned carbon nanotube (ACNT) arrays over stainless-steel foil are reported as high-performance binder-free anodes for lithium ion batteries. The coaxial arrays were prepared by growth of ACNTs over stainless-steel foil followed by coating with metal oxide and carbon. The carbon/manganese oxide/ACNT arrays can deliver an initial capacity of 738 mAh g(-1) with 99.9 % capacity retention up to 100 cycles and a capacity of 374 mAh g(-1) at a high current density of 6000 mA g(-1). The external carbon layer was recognized as a key component for high performance, and the mechanism of performance enhancement was investigated by electrochemical impedance spectroscopy, electron microscopy, and X-ray diffraction analysis. The layer increases rate capability by enhancing electrical conductivity and maintaining a low mass-transfer resistance and also improves cyclic stability by avoiding aggregation of metal-oxide particles and stabilizing the solid electrolyte interface. The resultant principle of rational electrode design was applied to an iron oxide-based system, and similar improvements were found. These coaxial nanotube arrays present a promising strategy for the rational design of high-performance binder-free anodes for lithium ion batteries. PMID:24578068

  20. Micro-nanostructured CuO/C spheres as high-performance anode materials for Na-ion batteries.

    PubMed

    Lu, Yanying; Zhang, Ning; Zhao, Qing; Liang, Jing; Chen, Jun

    2015-02-14

    In this paper, we report on the synthesis of micro-nanostructured CuO/C spheres by aerosol spray pyrolysis and their application as high-performance anodes in sodium-ion batteries. Micro-nanostructured CuO/C spheres with different CuO contents were synthesized through aerosol spray pyrolysis by adjusting the ratio of reactants and heat-treated by an oxidation process. The as-prepared CuO/C spheres show uniformly spherical morphology, in which CuO nanoparticles (∼10 nm) are homogeneously embedded in the carbon matrix (denoted as 10-CuO/C). The electrochemical performance of 10-CuO/C with a carbon weight of 44% was evaluated as the anode material for Na-ion batteries. It can deliver a capacity of 402 mA h g(-1) after 600 cycles at a current density of 200 mA g(-1). Furthermore, a capacity of 304 mA h g(-1) was obtained at a high current density of 2000 mA g(-1). The superior electrochemical performance of the micro-nanostructured CuO/C spheres leads to the enhancement of the electronic conductivity of the nanocomposite and the accommodation of the volume variation of CuO/C during charge/discharge cycling. PMID:25584745

  1. Synthesis and tribological properties of diamond-like carbon films by electrochemical anode deposition

    NASA Astrophysics Data System (ADS)

    Li, Yang; Zhang, GuiFeng; Hou, XiaoDuo; Deng, DeWei

    2012-06-01

    Diamond-like carbon films (DLC) are deposited on Ti substrate by electrochemical anodic deposition at room temperature in pure methanol solution using a pulsed DC voltage at a range from 200 V to 2000 V. Raman spectroscopy analysis of the films reveals two broaden characteristic absorption peaks centred at ˜1350 cm-1 and 1580 cm-1, relating to D- and G-band of typical DLC films, respectively. A broad peak centred at 1325-1330 cm-1 is observed when an applied potential is 1200 V, which can confirm that the deposited films contained diamond structure phase. Tribological properties of the coated Ti substrates have been measured by means of a ball-on-plate wear test machine. A related growth mechanism of DLC films by the anodic deposition mode has also been discussed.

  2. Vertical single- and double-walled carbon nanotubes grown from modified porous anodic alumina templates

    NASA Astrophysics Data System (ADS)

    Maschmann, Matthew R.; Franklin, Aaron D.; Amama, Placidus B.; Zakharov, Dmitri N.; Stach, Eric A.; Sands, Timothy D.; Fisher, Timothy S.

    2006-08-01

    Vertical single-walled and double-walled carbon nanotube (SWNT and DWNT) arrays have been grown using a catalyst embedded within the pore walls of a porous anodic alumina (PAA) template. The initial film structure consisted of a SiOx adhesion layer, a Ti layer, a bottom Al layer, a Fe layer, and a top Al layer deposited on a Si wafer. The Al and Fe layers were subsequently anodized to create a vertically oriented pore structure through the film stack. CNTs were synthesized from the catalyst layer by plasma-enhanced chemical vapour deposition (PECVD). The resulting structure is expected to form the basis for development of vertically oriented CNT-based electronics and sensors.

  3. Supercritical Carbon Dioxide-Assisted Process for Well-Dispersed Silicon/Graphene Composite as a Li ion Battery Anode

    PubMed Central

    Lee, Sang Ha; Park, Sengyoen; Kim, Min; Yoon, Dohyeon; Chanthad, Chalathorn; Cho, Misuk; Kim, Jaehoon; Park, Jong Hyeok; Lee, Youngkwan

    2016-01-01

    The silicon (Si)/graphene composite has been touted as one of the most promising anode materials for lithium ion batteries. However, the optimal fabrication method for this composite remains a challenge. Here, we developed a novel method using supercritical carbon dioxide (scCO2) to intercalate Si nanoparticles into graphene nanosheets. Silicon was modified with a thin layer of polyaniline, which assisted the dispersion of graphene sheets by introducing π-π interaction. Using scCO2, well-dispersed Si/graphene composite was successfully obtained in a short time under mild temperature. The composite showed high cycle performance (1,789 mAh/g after 250 cycles) and rate capability (1,690 mAh/g at a current density of 4,000 mA/g). This study provides a new approach for cost-effective and scalable preparation of a Si/graphene composite using scCO2 for a highly stable lithium battery anode material. PMID:27535108

  4. Supercritical Carbon Dioxide-Assisted Process for Well-Dispersed Silicon/Graphene Composite as a Li ion Battery Anode.

    PubMed

    Lee, Sang Ha; Park, Sengyoen; Kim, Min; Yoon, Dohyeon; Chanthad, Chalathorn; Cho, Misuk; Kim, Jaehoon; Park, Jong Hyeok; Lee, Youngkwan

    2016-01-01

    The silicon (Si)/graphene composite has been touted as one of the most promising anode materials for lithium ion batteries. However, the optimal fabrication method for this composite remains a challenge. Here, we developed a novel method using supercritical carbon dioxide (scCO2) to intercalate Si nanoparticles into graphene nanosheets. Silicon was modified with a thin layer of polyaniline, which assisted the dispersion of graphene sheets by introducing π-π interaction. Using scCO2, well-dispersed Si/graphene composite was successfully obtained in a short time under mild temperature. The composite showed high cycle performance (1,789 mAh/g after 250 cycles) and rate capability (1,690 mAh/g at a current density of 4,000 mA/g). This study provides a new approach for cost-effective and scalable preparation of a Si/graphene composite using scCO2 for a highly stable lithium battery anode material. PMID:27535108

  5. Phosphorus-doped tin oxides/carbon nanofibers webs as lithium-ion battery anodes with enhanced reversible capacity

    NASA Astrophysics Data System (ADS)

    Liu, Xiaowei; Teng, Donghua; Li, Ting; Yu, Yunhua; Shao, Xiaohong; Yang, Xiaoping

    2014-12-01

    Phosphorus-doped tin oxides/carbon nanofibers (P-SnOx/CNFs) composite materials are prepared via electrospinning of a mixed solution composed of polyacrylonitrile (PAN), N,N-dimethyl formamide (DMF), tin tetrachloride, ethylene glycol and phosphoric acid as well as subsequent thermal treatments. The P-SnOx/CNFs samples with tunable P-doping contents are directly used as anodes for lithium-ion batteries without any binders and conductors, exhibiting enhanced reversible capacities and cycling stabilities in comparison with pristine undoped SnOx/CNFs (0P-SnOx/CNFs). In a controlled experiment, the 0.25P-SnOx/CNFs anode with the atomic ratio of P:Sn = 0.25:1 shows the highest specific reversible capacity of 676 mA h g-1 at 200 mA g-1 after 100 cycles. Even at a higher current density of 2000 mA g-1, it still maintains a superior specific reversible capacity of 288 mA h g-1. The improved electrochemical performances are attributed to the P-doping effects such as inducement of a stable structural protection for tin particles, and enhancement of lithium ion diffusion coefficient and electron kinetics of electrode materials.

  6. Investigation of residual anode material after electrorefining uranium in molten chloride salt

    NASA Astrophysics Data System (ADS)

    Rose, M. A.; Williamson, M. A.; Willit, J.

    2015-12-01

    A buildup of material at uranium anodes during uranium electrorefining in molten chloride salts has been observed. Potentiodynamic testing has been conducted using a three electrode cell, with a uranium working electrode in both LiCl/KCl eutectic and LiCl each containing ∼5 mol% UCl3. The anodic current response was observed at 50° intervals between 450 °C and 650 °C in the eutectic salt. These tests revealed a buildup of material at the anode in LiCl/KCl salt, which was sampled at room temperature, and analyzed using ICP-MS, XRD and SEM techniques. Examination of the analytical data, current response curves and published phase diagrams has established that as the uranium anode dissolves, the U3+ ion concentration in the diffusion layer surrounding the electrode rises precipitously to levels, which may at low temperatures exceed the solubility limit for UCl3 or in the case of the eutectic salt for K2UCl5. The reduction in current response observed at low temperature in eutectic salt is eliminated at 650 °C, where K2UCl5 is absent due to its congruent melting and only simple concentration polarization effects are seen. In LiCl similar concentration effects are seen though significantly longer time at applied potential is required to effect a reduction in the current response as compared to the eutectic salt.

  7. Dopamine as the coating agent and carbon precursor for the fabrication of N-doped carbon coated Fe3O4 composites as superior lithium ion anodes

    NASA Astrophysics Data System (ADS)

    Lei, Cheng; Han, Fei; Li, Duo; Li, Wen-Cui; Sun, Qiang; Zhang, Xiang-Qian; Lu, An-Hui

    2013-01-01

    Dopamine is an excellent and flexible agent for surface coating of inorganic nanoparticles and contains unusually high concentrations of amine groups. In this study, we demonstrate that through a controlled coating of a thin layer of polydopamine on the surface of α-Fe2O3 in the dopamine aqueous solution, followed by subsequent carbonization, N-doped carbon-encapsulated magnetite has been synthesized and shows excellent electrochemical performance as anode material for lithium-ion batteries. Due to the strong binding affinity to iron oxide and excellent coating capability of this new carbon precursor, the conformal polydopamine derived carbon is continuous and uniform, and its thickness can be tailored. Moreover, due to the high percentage of nitrogen content in the precursor, the resulting carbon layer contains a moderate amount of N species, which can substantially improve the electrochemical performance. The composites synthesized by this facile method exhibit superior electrochemical performance, including remarkably high specific capacity (>800 mA h g-1 at a current of 500 mA g-1), high rate capability (595 and 396 mA h g-1 at a current of 1000 and 2000 mA g-1, respectively) and excellent cycle performance (200 cycles with 99% capacity retention), which adds to the potential as promising anodes for the application in lithium-ion batteries.Dopamine is an excellent and flexible agent for surface coating of inorganic nanoparticles and contains unusually high concentrations of amine groups. In this study, we demonstrate that through a controlled coating of a thin layer of polydopamine on the surface of α-Fe2O3 in the dopamine aqueous solution, followed by subsequent carbonization, N-doped carbon-encapsulated magnetite has been synthesized and shows excellent electrochemical performance as anode material for lithium-ion batteries. Due to the strong binding affinity to iron oxide and excellent coating capability of this new carbon precursor, the conformal

  8. Recent developments in anode materials for lithium batteries

    NASA Astrophysics Data System (ADS)

    Thackeray, M. M.; Vaughey, J. T.; Fransson, L. M. L.

    2002-03-01

    Lithium-ion batteries, preferred for their high energy and power, also present several challenges. Of particular concern are unsafe conditions that can arise in lithium-ion cells that operate with a fully lithiated graphite electrode. If the cells in those batteries are overcharged, especially in large-scale applications, thermal runaway, venting, fire, and explosion could result. This paper examines research into alternative, intermetallic electrode materials.

  9. A Designed TiO2 /Carbon Nanocomposite as a High-Efficiency Lithium-Ion Battery Anode and Photocatalyst.

    PubMed

    Peng, Liang; Zhang, Huijuan; Bai, Yuanjuan; Feng, Yangyang; Wang, Yu

    2015-10-12

    Herein, a peapod-like TiO2 /carbon nanocomposite has successfully been synthesized by a rational method for the first time. The novel nanostructure exhibits a distinct feature of TiO2 nanoparticles encapsulated inside and the carbon fiber coating outside. In the synthetic process, H2 Ti3 O7 nanotubes serve as precursors and templates, and glucose molecules act as the green carbon source. With the alliciency of hydrogen bonding between H2 Ti3 O7 and glucose, a thin polymer layer is hydrothermally assembled and subsequently converted into carbon fibers through calcinations under an inert atmosphere. Meanwhile, the precursors of H2 Ti3 O7 nanotubes are transformed into the TiO2 nanoparticles encapsulated in carbon fibers. The achieved unique nanocomposites can be used as excellent anode materials in lithium-ion batteries (LIBs) and photocatalytic reagents in the degradation of rhodamine B. Due to the synergistic effect derived from TiO2 nanoparticles and carbon fibers, the obtained peapod-like TiO2 /carbon cannot only deliver a high specific capacity of 160 mAh g(-1) over 500 cycles in LIBs, but also perform a much faster photodegradation rate than bare TiO2 and P25. Furthermore, owing to the low cost, environmental friendliness as well as abundant source, this novel TiO2 /carbon nanocomposite will have a great potential to be extended to other application fields, such as specific catalysis, gas sensing, and photovoltaics. PMID:26310518

  10. Anodized titania: Processing and characterization to improve cell-materials interactions for load bearing implants

    NASA Astrophysics Data System (ADS)

    Das, Kakoli

    The objective of this study is to investigate in vitro cell-materials interactions using human osteoblast cells on anodized titanium. Titanium is a bioinert material and, therefore, gets encapsulated after implantation into the living body by a fibrous tissue that isolates them from the surrounding tissues. In this work, bioactive nonporous and nanoporous TiO2 layers were grown on commercially pure titanium substrate by anodization process using different electrolyte solutions namely (1) H3PO 4, (2) HF and (3) H2SO4, (4) aqueous solution of citric acid, sodium fluoride and sulfuric acid. The first three electrolytes produced bioactive TiO2 films with a nonporous structure showing three distinctive surface morphologies. Nanoporous morphology was obtained on Ti-surfaces from the fourth electrolyte at 20V for 4h. Cross-sectional view of the nanoporous surface reveals titania nanotubes of length 600 nm. It was found that increasing anodization time initially increased the height of the nanotubes while maintaining the tubular array structure, but beyond 4h, growth of nanotubes decreased with a collapsed array structure. Human osteoblast (HOB) cell attachment and growth behavior were studied using an osteoprecursor cell line (OPC 1) for 3, 7 and 11 days. Colonization of the cells was noticed with distinctive cell-to-cell attachment on HF anodized surfaces. TiO2 layer grown in H2SO4 electrolyte did not show significant cell growth on the surface, and some cell death was also noticed. Good cellular adherence with extracellular matrix extensions in between the cells was noticed for samples anodized with H3PO 4 electrolyte and nanotube surface. Cell proliferation was excellent on anodized nanotube surfaces. An abundant amount of extracellular matrix (ECM) between the neighboring cells was also noticed on nanotube surfaces with filopodia extensions coming out from cells to grasp the nanoporous surface for anchorage. To better understand and compare cell-materials interactions

  11. Carbon materials for supercapacitor application.

    PubMed

    Frackowiak, Elzbieta

    2007-04-21

    The most commonly used electrode materials for electrochemical capacitors are activated carbons, because they are commercially available and cheap, and they can be produced with large specific surface area. However, only the electrochemically available surface area is useful for charging the electrical double layer (EDL). The EDL formation is especially efficient in carbon pores of size below 1 nm because of the lack of space charge and a good attraction of ions along the pore walls. The pore size should ideally match the size of the ions. However, for good dynamic charge propagation, some small mesopores are useful. An asymmetric configuration, where the positive and negative electrodes are constructed from different materials, e.g., activated carbon, transition metal oxide or conducting polymer, is of great interest because of an important extension of the operating voltage. In such a case, the energy as well as power is greatly increased. It appears that nanotubes are a perfect conducting additive and/or support for materials with pseudocapacitance properties, e.g. MnO(2), conducting polymers. Substitutional heteroatoms in the carbon network (nitrogen, oxygen) are a promising way to enhance the capacitance. Carbons obtained by one-step pyrolysis of organic precursors rich in heteroatoms (nitrogen and/or oxygen) are very interesting, because they are denser than activated carbons. The application of a novel type of electrolyte with a broad voltage window (ionic liquids) is considered, but the stability of this new generation of electrolyte during long term cycling of capacitors is not yet confirmed. PMID:17415488

  12. Hierarchical Nanocomposite of Hollow N-Doped Carbon Spheres Decorated with Ultrathin WS2 Nanosheets for High-Performance Lithium-Ion Battery Anode.

    PubMed

    Zeng, Xiaohui; Ding, Zhengping; Ma, Cheng; Wu, Laidi; Liu, Jiatu; Chen, Libao; Ivey, Douglas G; Wei, Weifeng

    2016-07-27

    Hierarchical nanocomposite of ultrathin WS2 nanosheets uniformly attached on the surface of hollow nitrogen-doped carbon spheres (WS2@HNCSs) were successfully fabricated via a facile synthesis strategy. When evaluated as an anode material for LIBs, the hierarchical WS2@HNCSs exhibit a high specific capacity of 801.4 mA h g(-1) at 0.1 A g(-1), excellent rate capability (545.6 mA h g(-1) at a high current density of 2 A g(-1)), and great cycling stability with a capacity retention of 95.8% after 150 cycles at 0.5 A g(-1). The Li-ion storage properties of our WS2@HNCSs nanocomposite are much better than those of the previously most reported WS2-based anode materials. The impressive electrochemical performance is attributed to the robust nanostructure and the favorable synergistic effect between the ultrathin (3-5 layers) WS2 nanosheets and the highly conductive hollow N-doped carbon spheres. The hierarchical hybrid can simultaneously facilitate fast electron/ion transfer, effectively accommodate mechanical stress from cycling, restrain agglomeration, and enable full utilization of the active materials. These characteristics make WS2@HNCSs a promising anode material for high-performance LIBs. PMID:27381381

  13. Methods for purifying carbon materials

    DOEpatents

    Dailly, Anne; Ahn, Channing; Yazami, Rachid; Fultz, Brent T.

    2009-05-26

    Methods of purifying samples are provided that are capable of removing carbonaceous and noncarbonaceous impurities from a sample containing a carbon material having a selected structure. Purification methods are provided for removing residual metal catalyst particles enclosed in multilayer carbonaceous impurities in samples generate by catalytic synthesis methods. Purification methods are provided wherein carbonaceous impurities in a sample are at least partially exfoliated, thereby facilitating subsequent removal of carbonaceous and noncarbonaceous impurities from the sample. Methods of purifying carbon nanotube-containing samples are provided wherein an intercalant is added to the sample and subsequently reacted with an exfoliation initiator to achieve exfoliation of carbonaceous impurities.

  14. Finding out the optimal boron concentration in BCx sheets for high capacity anode material in Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Das, Deya; Hardikar, Rahul; Han, Sang Soo; Lee, Kwang Ryeol; Singh, Abhishek Kumar

    Boron doped graphene shows better adsorption of Li compared to pristine graphene and has been investigated as a potential anode material for Li-ion batteries. Using first principles density functional theory calculations, we investigate the effect of increasing boron concentration on the gravimetric capacity of mono-layered boron doped graphene sheets, BCx (x = 7, 5, 3, 2 and 1). Li storage capacity increases with the increase in boron concentration giving highest capacity for monolayer BC2 (~ 1400 mAh/g), and is about 1.6 times higher than previously reported capacity of BC3. This is due to the more number of available empty states above the Fermi level in BC2 compared to other sheets. Moreover, owing to a very low Li diffusion barrier, the Li kinetics in BC2 is also found to be better among all the layered boron doped carbon sheets. Further enhancement of B concentration, as in BC, leads to strong binding of Li, thereby hindering the delithiation processes. Hence, BC2 with optimal concentration of B among the BCx phases, emerges as a promising choice for anode material in rechargeable Li ion battery.

  15. Suitability of new anode materials in mammography: Dose and subject contrast considerations using Monte Carlo simulation

    SciTech Connect

    Delis, H.; Spyrou, G.; Costaridou, L.; Tzanakos, G.; Panayiotakis, G.

    2006-11-15

    Mammography is the technique with the highest sensitivity and specificity, for the early detection of nonpalpable lesions associated with breast cancer. As screening mammography refers to asymptomatic women, the task of optimization between the image quality and the radiation dose is critical. A way toward optimization could be the introduction of new anode materials. A method for producing the x-ray spectra of different anode/filter combinations is proposed. The performance of several mammographic spectra, produced by both existing and theoretical anode materials, is evaluated, with respect to their dose and subject contrast characteristics, using a Monte Carlo simulation.The mammographic performance is evaluated utilizing a properly designed mathematical phantom with embedded inhomogeneities, irradiated with different spectra, based on combinations of conventional and new (Ru, Ag) anode materials, with several filters (Mo, Rh, Ru, Ag, Nb, Al). An earlier developed and validated Monte Carlo model, for deriving both image and dose characteristics in mammography, was utilized and overall performance results were derived in terms of subject contrast to dose ratio and squared subject contrast to dose ratio. Results demonstrate that soft spectra, mainly produced from Mo, Rh, and Ru anodes and filtered with k-edge filters, provide increased subject contrast for inhomogeneities of both small size, simulating microcalcifications and low density, simulating masses. The harder spectra (W and Ag anode) come short in the discrimination task but demonstrate improved performance when considering the dose delivered to the breast tissue. As far as the overall performance is concerned, new theoretical spectra demonstrate a noticeable good performance that is similar, and in some cases better compared to commonly used systems, stressing the possibility of introducing new materials in mammographic practice as a possible contribution to its optimization task. In the overall

  16. Laboratory-scale testing of non-consumable anode materials: Inert Electrodes Program

    SciTech Connect

    Marschman, S.C.

    1989-03-01

    Development of inert anode materials for use in the electrolytic production of aluminum is one of the major goals of the Inert Electrodes Program sponsored by the US Department of Energy, Office of Industrial Programs, at Pacific Northwest Laboratory. The objectives of the Materials Development and Testing Task include the selection, fabrication, and evaluation of candidate non-consumable anode materials. Research performed in FY 1987 focused primarily on the development and evaluation of cermets that are based on the two-phase oxide system NiO/endash/NiFe/sub 2/O/sub 4/ and contain a third, electrically conductive metal phase composed primarily of copper and nickel. The efforts of this task were focused on three areas: materials fabrication, small-scale materials testing, and laboratory-scale testing. This report summarizes the development and testing results of the laboratory-scale testing effort during FY 1987. The laboratory-scale electrolysis testing effort was instrumental in partially determining electrolysis cell operating parameters. Although not optimized, NiO/endash/NiFe/sub 2/O/sub 4//endash/Cu-based cermets were successfully operated for 20 h in cryolite-based electrolytes ranging in bath ratios from 1.1 to 1.35, in electrolytes that contained 1.5 wt % LiF, and at conditions slightly less than Al/sub 2/O/sub 3/ saturation. The operating conditions that lead to anode degradation have been partly identified, and rudimentary control methods have been developed to ensure proper operation of small electrolysis cells using nonconsumable anodes. 11 figs., 1 tab.

  17. Investigation of carbon supported Pd-Cu nanoparticles as anode catalysts for direct borohydride fuel cell

    NASA Astrophysics Data System (ADS)

    Behmenyar, Gamze; Akın, Ayşe Nilgün

    2014-03-01

    Carbon supported Pd and bimetallic Pd-Cu nanoparticles with different compositions are prepared by a modified polyol method and used as anode catalysts for direct borohydride fuel cell (DBFC). The physical and electrochemical properties of the as-prepared electrocatalysts are investigated by transmission electron microscopy (TEM), X-ray diffraction (XRD), ICP-AES, cyclic voltammetry (CV), chronoamperometry (CA), and fuel cell experiments. The results show that the carbon supported Pd-Cu bimetallic catalysts have much higher catalytic activity for the direct oxidation of BH4- than the carbon supported pure nanosized Pd catalyst, especially the Pd50Cu50/C catalyst presents the highest catalytic activity among all as-prepared catalysts, and the DBFC using Pd50Cu50/C as anode catalyst and Pt/C as cathode catalyst gives the best performance, and the maximum power density is 98 mW cm-2 at a current density of 223 mA cm-2 at 60 °C.

  18. Sequestration of CO2 discharged from anode by algal cathode in microbial carbon capture cells (MCCs).

    PubMed

    Wang, Xin; Feng, Yujie; Liu, Jia; Lee, He; Li, Chao; Li, Nan; Ren, Nanqi

    2010-08-15

    Due to increased discharge of CO(2) is incurring problems, CO(2) sequestration technologies require substantial development. By introducing anodic off gas into an algae grown cathode (Chlorella vulgaris), new microbial carbon capture cells (MCCs) were constructed and demonstrated here to be an effective technology for CO(2) emission reduction with simultaneous voltage output without aeration (610+/-50 mV, 1000 Omega). Maximum power densities increased from 4.1 to 5.6 W/m(3) when the optical density (OD) of cathodic algae suspension increased from 0.21 to 0.85 (658 nm). Compared to a stable voltage of 706+/-21 mV (1000 Omega) obtained with cathodic dissolved oxygen (DO) of 6.6+/-1.0 mg/L in MCC, voltage outputs decreased from 654 to 189 mV over 70 h in the control reactor (no algae) accompanied with a decrease in DO from 7.6 to 0.9 mg/L, indicating that cathode electron acceptor was oxygen. Gas analysis showed that all the CO(2) generated from anode was completely eliminated by catholyte, and the soluble inorganic carbon was further converted into algal biomass. These results showed the possibility of a new method for simultaneous carbon fixing, power generation and biodiesel production during wastewater treatment without aeration. PMID:20547055

  19. ON THE ANODIC POLARIZATION BEHAVIOR OF CARBON STEEL IN HANFORD NUCLEAR WASTES

    SciTech Connect

    BOOMER, K.D.

    2007-01-31

    The effect of the important chemical constituents in the Hanford nuclear waste simulant on the anodic behavior of carbon steel was studied. Specifically, the effect of pH, nitrite concentration, nitrite/nitrate concentration ratios, total organic carbon and the chloride concentration on the open circuit potential, pitting potential and repassivation potential was evaluated. It was found that pH adjusting, although capable of returning the tank chemistry back to specification, did not significantly reduce the corrosivity of the stimulant compared to the present condition. Nitrite was found to be a potent inhibitor for carbon steel. A critical concentration of approximately 1.2M appeared to be beneficial to increase the difference of repassivation potential and open circuit potential considerably and thus prevent pitting corrosion from occurring. No further benefit was gained when increasing nitrite concentration to a higher level. The organic compounds were found to be weak inhibitors in the absence of nitrite and the change of chloride from 0.05M to 0.2M did not alter the anodic behavior dramatically.

  20. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon---carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  1. Pistons and Cylinders Made of Carbon-Carbon Composite Materials

    NASA Technical Reports Server (NTRS)

    Rivers, H. Kevin (Inventor); Ransone, Philip O. (Inventor); Northam, G. Burton (Inventor); Schwind, Francis A. (Inventor)

    2000-01-01

    An improved reciprocating internal combustion engine has a plurality of engine pistons, which are fabricated from carbon-carbon composite materials, in operative association with an engine cylinder block, or an engine cylinder tube, or an engine cylinder jug, all of which are also fabricated from carbon-carbon composite materials.

  2. Bacterial nanometric amorphous Fe-based oxide: a potential lithium-ion battery anode material.

    PubMed

    Hashimoto, Hideki; Kobayashi, Genki; Sakuma, Ryo; Fujii, Tatsuo; Hayashi, Naoaki; Suzuki, Tomoko; Kanno, Ryoji; Takano, Mikio; Takada, Jun

    2014-04-23

    Amorphous Fe(3+)-based oxide nanoparticles produced by Leptothrix ochracea, aquatic bacteria living worldwide, show a potential as an Fe(3+)/Fe(0) conversion anode material for lithium-ion batteries. The presence of minor components, Si and P, in the original nanoparticles leads to a specific electrode architecture with Fe-based electrochemical centers embedded in a Si, P-based amorphous matrix. PMID:24689687

  3. Exploration of a calcium-organic framework as an anode material for sodium-ion batteries.

    PubMed

    Zhang, Yan; Niu, Yubin; Wang, Min-Qiang; Yang, Jingang; Lu, Shiyu; Han, Jin; Bao, Shu-Juan; Xu, Maowen

    2016-08-01

    In this communication, we designed and synthesized a novel calcium-organic framework and presented it as an anode material for sodium-ion batteries. The results show that it delivers a reversible capacity of higher than 140 mA h g(-1) even after 300 cycles. The remarkable performance is attributed to the high structural stability and extremely low solubility of the calcium-organic framework in electrolytes. PMID:27440582

  4. Preparation of porous nickel-titania cermets and their application to anode materials

    SciTech Connect

    Taimatsu, H.; Kudo, K.; Kaneko, H.; Matsukaze, N.; Iwata, T.

    1995-12-31

    Porous nickel-titania cermets have been prepared as new-type anode materials for solid oxide fuel cells using the solid-state displacement reaction method. The microstructures of the cermets were interwoven aggregate-type, differently from those of conventional nickel-YSZ cermets: nickel and titania phases three-dimensionally entangled each other. These cermets revealed good properties in compatibility of thermal expansion with YSZ, strength, gas permeation and electrical conduction.

  5. Carbon Nanotube Material Quality Assessment

    NASA Technical Reports Server (NTRS)

    Yowell, Leonard; Arepalli, Sivaram; Sosa, Edward; Niolaev, Pavel; Gorelik, Olga

    2006-01-01

    The nanomaterial activities at NASA Johnson Space Center focus on carbon nanotube production, characterization and their applications for aerospace systems. Single wall carbon nanotubes are produced by arc and laser methods. Characterization of the nanotube material is performed using the NASA JSC protocol developed by combining analytical techniques of SEM, TEM, UV-VIS-NIR absorption, Raman, and TGA. A possible addition of other techniques such as XPS, and ICP to the existing protocol will be discussed. Changes in the quality of the material collected in different regions of the arc and laser production chambers is assessed using the original JSC protocol. The observed variations indicate different growth conditions in different regions of the production chambers.

  6. Flexible, Freestanding, and Binder-free SnOx-ZnO/Carbon Nanofiber Composites for Lithium Ion Battery Anodes.

    PubMed

    Joshi, Bhavana N; An, Seongpil; Jo, Hong Seok; Song, Kyo Yong; Park, Hyun Goo; Hwang, Sunwoo; Al-Deyab, Salem S; Yoon, Woo Young; Yoon, Sam S

    2016-04-13

    Here, we demonstrate the production of electrospun SnOx-ZnO polyacrylonitrile (PAN) nanofibers (NFs) that are flexible, freestanding, and binder-free. This NF fabric is flexible and thus can be readily tailored into a coin for further cell fabrication. These properties allow volume expansion of the oxide materials and provide shortened diffusion pathways for Li ions than those achieved using the nanoparticle approach. Amorphous SnOx-ZnO particles were uniformly dispersed in the carbon NF (CNF). The SnOx-ZnO CNFs with a Sn:Zn ratio of 3:1 exhibited a superior reversible capacity of 963 mA·h·g(-1) after 55 cycles at a current density of 100 mA·g(-1), which is three times higher than the capacity of graphite-based anodes. The amorphous NFs facilitated Li2O decomposition, thereby enhancing the reversible capacity. ZnO prevented the aggregation of Sn, which, in turn, conferred stable and high discharge capacity to the cell. Overall, the SnOx-ZnO CNFs were shown to exhibit remarkably high capacity retention and high reversible and rate capacities as Li ion battery anodes. PMID:26999581

  7. Multidimensional Germanium-Based Materials as Anodes for Lithium-Ion Batteries.

    PubMed

    Qin, Jinwen; Cao, Minhua

    2016-04-20

    Metallic germanium is an ideal anode for lithium-ion batteries (LIBs), owing to its high theoretical capacity (1624 mA h g(-1) ) and low operating voltage. Herein, we highlight recent advances in the development of Ge-based anodes in LIBs, although improvements in their coulombic efficiency (CE), capacity retention, and rate performance are still required. One of the major concerns facing the development of Ge anodes is the controlled formation of microstructures. In this Focus Review, we summarize Ge-based materials with different structural dimensions, that is, zero-dimensional (0D), one-dimensional (1D), two-dimensional (2D), three-dimensional (3D), and even monolithic and macroscale structures. Moreover, the design of Ge-based oxide materials, as an effective route for achieving higher Li-storage capacities and cycling performance, is also discussed. Finally, we briefly summarize new types of Ge-based materials, such as ternary germanium oxides, germanium sulfides, and germanium phosphides, and predict that they will bring about a reformation in the field of LIBs. PMID:26990878

  8. Lignin-Derived Advanced Carbon Materials.

    PubMed

    Chatterjee, Sabornie; Saito, Tomonori

    2015-12-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure-property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon, are discussed. PMID:26568373

  9. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templated carbon.

  10. From Dispersed Microspheres to Interconnected Nanospheres: Carbon-Sandwiched Monolayered MoS2 as High-Performance Anode of Li-Ion Batteries.

    PubMed

    Shao, Jie; Qu, Qunting; Wan, Zhongming; Gao, Tian; Zuo, Zhichen; Zheng, Honghe

    2015-10-21

    Hierarchical structured carbon@MoS2 (C@MoS2) microspheres and nanospheres composed of carbon-sandwiched monolayered MoS2 building blocks are synthesized through a facile one-pot polyvinylpyrrolidone (PVP) micelle-assisted hydrothermal route. The dimension and carbon content of C@MoS2 spheres are effectively controlled by singly adjusting the concentration of PVP, which plays the dual functions of soft-template and carbon source. As the anode materials of Li-ion batteries, C@MoS2 nanospheres present considerably higher capacity, better rate behavior and cycling stability than C@MoS2 microspheres. The reasons are attributed to the unique interconnected nanospherical morphology and the internal hierarchical construction of C@MoS2 nanospheres with expanded MoS2/carbon interlayer spacing. PMID:26426361

  11. Graphitic Carbon Conformal Coating of Mesoporous TiO2 Hollow Spheres for High-Performance Lithium Ion Battery Anodes.

    PubMed

    Liu, Hao; Li, Wei; Shen, Dengke; Zhao, Dongyuan; Wang, Guoxiu

    2015-10-14

    Rational design and controllable synthesis of TiO2 based materials with unique microstructure, high reactivity, and excellent electrochemical performance for lithium ion batteries are crucially desired. In this paper, we developed a versatile route to synthesize hollow TiO2/graphitic carbon (H-TiO2/GC) spheres with superior electrochemical performance. The as-prepared mesoporous H-TiO2/GC hollow spheres present a high specific surface area (298 m(2) g(-1)), a high pore volume (0.31 cm(3) g(-1)), a large pore size (∼5 nm), well-defined hollow structure (monodispersed size of 600 nm and inner diameter of ∼400 nm, shell thickness of 100 nm), and small nanocrystals of anatase TiO2 (∼8 nm) conformably encapsulated in ultrathin graphitic carbon layers. As a result, the H-TiO2/GC hollow spheres achieve excellent electrochemical reactivity and stability as an anode material for lithium ion batteries. A high specific capacity of 137 mAh g(-1) can be achieved up to 1000 cycles at a current density of 1 A g(-1) (5 C). We believe that the mesoporous H-TiO2/GC hollow spheres are expected to be applied as a high-performance electrode material for next generation lithium ion batteries. PMID:26414170

  12. One-Pot Synthesis of SnO2/C Nanocapsules Composites as Anode Materials for Lithium-Ion Batteries.

    PubMed

    Yang, Lina; Chen, Kexun; Dong, Tao; Wang, Zhao; Li, Guomin; Zhang, Yanling; Zhang, Lipeng

    2016-02-01

    In this work, we demonstrate a facile route for the synthesis of nanostructured SnO2/C composites for lithium-ion batteries. The anode materials were prepared via a one-pot solvothermal approach and then calcination in a highly pure nitrogen atmosphere. The composited was composed of amor- phous carbon and nanocrystalline SnO2 by the X-ray diffraction (XRD) analysis, and the content of carbon was calculated according to the thermogravimetric analysis (TGA). Scanning electron microscopy (SEM) images revealed that the diameter of these as-prepared spheres varied from 50 to 60 nm. A systematic study has been carried out to examine the effect of carbon content upon lithium-ion battery performance. The electrochemical results showed that SnO2/C nanocomposite could achieve 1197.5 mAh/g reversible capacity and 55.11% initial coulombic efficiency, and 190% capacity retention after 50 cycles compared to the SnO2 nanoparticles of 940.6 mAh/g at a current density 0.2 C in the voltage range of 0.01-3.0 V. These improvements can be ascribed to the carbon, which can enhance the conductivity of SnO2, suppress the aggregation of active particles, and increase their structural stability during cycling. PMID:27433668

  13. Polyaniline-assisted synthesis of Si@C/RGO as anode material for rechargeable lithium-ion batteries.

    PubMed

    Lin, Ning; Zhou, Jianbin; Wang, Liangbiao; Zhu, Yongchun; Qian, Yitai

    2015-01-14

    A novel approach to fabricate Si@carbon/reduced graphene oxides composite (Si@C/RGO) assisted by polyaniline (PANI) is developed. Here, PANI not only serves as "glue" to combine Si nanoparticles with graphene oxides through electrostatic attraction but also can be pyrolyzed as carbon layer coated on Si particles during subsequent annealing treatment. The assembled composite delivers high reversible capacity of 1121 mAh g(-1) at a current density of 0.9 A g(-1) over 230 cycles with improved initial Coulombic efficiency of 81.1%, while the bare Si and Si@carbon only retain specific capacity of 50 and 495 mAh g(-1) at 0.3 A g(-1) after 50 cycles, respectively. The enhanced electrochemical performance of Si@C/RGO can be attributed to the dual protection of carbon layer and graphene sheets, which are synergistically capable of overcoming the drawbacks of inner Si particles such as huge volume change and low conductivity and providing protective and conductive matrix to buffer the volume variation, prevent the Si particles from aggregating, enhance the conductivity, and stabilize the solid-electrolyte interface membrane during cycling. Importantly, this method opens a novel, universal graphene coating strategy, which can be extended to other fascinating anode and cathode materials. PMID:25494648

  14. Graphdiyne as a high-capacity lithium ion battery anode material

    SciTech Connect

    Jang, Byungryul; Koo, Jahyun; Park, Minwoo; Kwon, Yongkyung; Lee, Hoonkyung; Lee, Hosik; Nam, Jaewook

    2013-12-23

    Using the first-principles calculations, we explored the feasibility of using graphdiyne, a 2D layer of sp and sp{sup 2} hybrid carbon networks, as lithium ion battery anodes. We found that the composite of the Li-intercalated multilayer α-graphdiyne was C{sub 6}Li{sub 7.31} and that the calculated voltage was suitable for the anode. The practical specific/volumetric capacities can reach up to 2719 mAh g{sup −1}/2032 mAh cm{sup −3}, much greater than the values of ∼372 mAh g{sup −1}/∼818 mAh cm{sup −3}, ∼1117 mAh g{sup −1}/∼1589 mAh cm{sup −3}, and ∼744 mAh g{sup −1} for graphite, graphynes, and γ-graphdiyne, respectively. Our calculations suggest that multilayer α-graphdiyne can serve as a promising high-capacity lithium ion battery anode.

  15. Materials property definition and generation for carbon-carbon and carbon phenolic materials

    NASA Technical Reports Server (NTRS)

    Canfield, A. R.; Mathis, J. R.; Starrett, H. S.; Koenig, J. R.

    1987-01-01

    A data base program to generate statistically significant material-property data for carbon-carbon and carbon phenolic materials to be used in designs of Space Shuttle is described. The program, which will provide data necessary for thermal and stress modeling of Shuttle nozzle and exit cone structures, includes evaluation of tension, compression, shear strength, shear modulus, thermal expansion, thermal conductivity, permeability, and emittance for both materials; the testing of carbon phenolic materials also includes CTE, off-gassing, pyrolysis, and RTG. Materials to be tested will be excised from Space Shuttle inlet, throat, and exit cone billets and modified involute carbon-carbon exit cones; coprocessed blocks, panels, and cylinders will also be tested.

  16. Hydrothermal synthesis and potential applicability of rhombohedral siderite as a high-capacity anode material for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Shiqiang; Yu, Yue; Wei, Shanshan; Wang, Yuxi; Zhao, Chenhao; Liu, Rui; Shen, Qiang

    2014-05-01

    Natural siderite is a valuable iron mineral composed of ferrous carbonate (FeCO3), which is commonly found in hydrothermal veins and contains no sulfur or phosphorus. In this paper, micro-sized FeCO3 crystallites are synthesized via a facile hydrothermal route, and almost all of them possess a rhombohedral shape similar to that of natural products. When applied as an anode material for lithium ion batteries, the synthetic siderite can deliver an initial specific discharge capacity of ∼1587 mAh g-1 with a coulombic efficiency of 68% at 200 mA g-1, remaining a reversible value of 1018 mAh g-1 over 120 cycles. Even at a high current density of 1000 mA g-1, after 120 cycles the residual specific capacity (812 mAh g-1) is still higher than the theoretical capacity of FeCO3 (463 mAh g-1). Moreover, a novel reversible conversion mechanism accounts for the excellent electrochemical performances of rhombohedral FeCO3 to a great extent, implying the potential applicability of synthetic siderite as lithium ion battery anodes.

  17. Monolithic Graphene Trees as Anode Material for Lithium Ion Batteries with High C-Rates.

    PubMed

    Jeong, Seung Yol; Yang, Sunhye; Jeong, Sooyeon; Kim, Ick Jun; Jeong, Hee Jin; Han, Joong Tark; Baeg, Kang-Jun; Lee, Geon-Woong

    2015-06-01

    Monolithically structured reduced graphene oxide (rGO), prepared from a highly concentrated and conductive rGO paste, is introduced as an anode material for lithium ion batteries with high rate capacities. This is achieved by a mixture of rGO paste and the water-soluble polymer sodium carboxymethylcellulose (SCMC) with freeze drying. Unlike previous 3D graphene porous structures, the monolithic graphene resembles densely branched pine trees and has high mechanical stability with strong adhesion to the metal electrodes. The structures contain numerous large surface area open pores that facilitate lithium ion diffusion, while the strong hydrogen bonding between the graphene layers and SCMC provides high conductivity and reduces the volume changes that occur during cycling. Ultrafast charge/discharge rates are obtained with outstanding cycling stability and the capacities are higher than those reported for other anode materials. The fabrication process is simple and straightforward to adjust and is therefore suitable for mass production of anode electrodes for commercial applications. PMID:25656352

  18. Magnetite Nanocrystals as Anode Electrode Materials for Rechargeable Li-Ion Batteries.

    PubMed

    Ma, Xiaoling; Zeng, Guoping; Chen, Gongxuan; Huang, Yuanqiao; Wu, Tian

    2015-09-01

    Monodispersed magnetite (Fe3O4) nanocrystals were synthesized and their electrochemical properties as anode electrode materials for rechargeable lithium ion batteries were measured. The magnetite anodes, in the form of monodispersed nanospheres with average diameters (< 10 nm), show particle size effects. Specifically, the first discharge curves show that the nanocrystals can hold much more Li+ per formula unit than their counterparts in bulk before the reduction begins. The electrolyte decomposition takes place before the reduction reaction is completed. The cycling performance of the Fe3O4 nanocrystals after being heated at 300 degrees C for different lengths of time show that heating can improve the integration of the nanocrystals and increase their capacity retention in consequence. PMID:26716309

  19. Physical characterization of tin composite oxides and related anode materials for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Goward, Gillian Ruth

    2000-10-01

    This thesis addresses the issues concerning the excellent electrochemical performance exhibited by the tin-composite-oxide glass, Sn1.0Al 0.42B0.56P0.40O3.6 as an anode material for rechargeable lithium ion batteries. The debate surrounding this material focuses on the nature of the lithium-tin interaction; whether it is ionic or intermetallic. The TCO anode material has been studied electrochemically, as well as by multinuclear Solid-State-NMR, X-ray Absorption Spectroscopy, and X-ray Scattering including Pair Distribution Function analysis. By examining electrode materials at various stages of discharge, corresponding to various levels of lithium insertion, the interactions between lithium, tin, oxygen, and the other components of the glass have been ascertained. The inserted lithium remains highly ionic throughout the first cycle of the cell, with no evidence for the formation of alloy phases. Extended cycling of the cell results in the formation of alloy-like domains in the parent material, SnO, but not in the case of TCO. This demonstrates that the required structural rearrangements for the formation of Li-Sn phases are kinetically prohibited; and this to a greater extend in TCO than in SnO. Two key factors account for the electrochemical properties of TCO: (1) the participation of the glass framework in sequestering the electrochemically active tin centers and providing a flexible framework for the reversible insertion of lithium; (2) the proximity of oxygen to tin is maintained throughout lithium insertion process, thus oxygen may act as a charge carrier. These factors are developed in the context of several models for the interactions in the electrode, drawing on the data obtained from the physical characterizations implemented here. A comparative study of the anode material NaMoO3 is also described.

  20. Micro-nanostructured CuO/C spheres as high-performance anode materials for Na-ion batteries

    NASA Astrophysics Data System (ADS)

    Lu, Yanying; Zhang, Ning; Zhao, Qing; Liang, Jing; Chen, Jun

    2015-01-01

    In this paper, we report on the synthesis of micro-nanostructured CuO/C spheres by aerosol spray pyrolysis and their application as high-performance anodes in sodium-ion batteries. Micro-nanostructured CuO/C spheres with different CuO contents were synthesized through aerosol spray pyrolysis by adjusting the ratio of reactants and heat-treated by an oxidation process. The as-prepared CuO/C spheres show uniformly spherical morphology, in which CuO nanoparticles (~10 nm) are homogeneously embedded in the carbon matrix (denoted as 10-CuO/C). The electrochemical performance of 10-CuO/C with a carbon weight of 44% was evaluated as the anode material for Na-ion batteries. It can deliver a capacity of 402 mA h g-1 after 600 cycles at a current density of 200 mA g-1. Furthermore, a capacity of 304 mA h g-1 was obtained at a high current density of 2000 mA g-1. The superior electrochemical performance of the micro-nanostructured CuO/C spheres leads to the enhancement of the electronic conductivity of the nanocomposite and the accommodation of the volume variation of CuO/C during charge/discharge cycling.In this paper, we report on the synthesis of micro-nanostructured CuO/C spheres by aerosol spray pyrolysis and their application as high-performance anodes in sodium-ion batteries. Micro-nanostructured CuO/C spheres with different CuO contents were synthesized through aerosol spray pyrolysis by adjusting the ratio of reactants and heat-treated by an oxidation process. The as-prepared CuO/C spheres show uniformly spherical morphology, in which CuO nanoparticles (~10 nm) are homogeneously embedded in the carbon matrix (denoted as 10-CuO/C). The electrochemical performance of 10-CuO/C with a carbon weight of 44% was evaluated as the anode material for Na-ion batteries. It can deliver a capacity of 402 mA h g-1 after 600 cycles at a current density of 200 mA g-1. Furthermore, a capacity of 304 mA h g-1 was obtained at a high current density of 2000 mA g-1. The superior

  1. Analysis of possibilities for carbon removal from porous anode of solid oxide fuel cells after different failure modes

    NASA Astrophysics Data System (ADS)

    Subotić, Vanja; Schluckner, Christoph; Schroettner, Hartmuth; Hochenauer, Christoph

    2016-01-01

    This study focuses on the investigation of possibilities for carbon removal from the fuel electrode of anode supported solid oxide fuel cells (ASC-SOFCs) after different degradation modes. To design the conditions which generally lead the cell in the range of carbon depositions the performed thermodynamic calculations show that the SOFC operating temperature range seems to be appropriate for formation of elemental carbon in various types. Concerning this the loaded large planar single SOFCs are fed with synthetic diesel reformate thus simulating realistic operating conditions and enabling the formation and deposition of carbon on the anode side. A mixture of hydrogen/water vapor/nitrogen is used to remove the detected carbon depositions in a cell-protecting manner. For the purpose of this investigation several failure modes are induced after which determination the already defined regeneration strategy is applied. The cathode degradation is first induced and secondly the fuel supply is interrupted to induce re-oxidation of nickel (Ni) on the anode side. The undertaken investigations determine that carbon can be fully removed from the anode surface after nickel oxidation, while cathode degradation disables the complete cell regeneration.

  2. Vertical devices from single-walled carbon nanotubes templated in porous anodic alumina

    NASA Astrophysics Data System (ADS)

    Franklin, Aaron D.

    Over the past decade, tremendous progress has been realized in the fabrication and characterization of single-walled carbon nanotube (CNT) electronic devices. For example, with advantages such as ballistic transport and the absence of surface states, CNTs have been proposed as an ideal 1D channel material for next generation field-effect transistors (FETs). However, the literature is replete with reports of individual high-performance devices that lack the demonstration or feasibility of being fabricated at a large scale. One of the primary obstacles to fabricating highly integrated CNT devices is the placement of the nanotubes at a defined spacing and in precise locations. Nearly all CNT devices to date have been configured in a planar geometry (with the CNT supported horizontally on a substrate) and have primarily relied on random processes for dispersing/growing and contacting the CNTs. Ideally, a high-performance CNTFET would consist of multiple, densely packed CNTs that are aligned, having surround gates, low-barrier contacts, and a sub-100 nm channel length. Such multi-nanotube CNTFETs should further be fabricated in a manner that can be scaled for high-level integration and that is compatible with modern CMOS processing. This dissertation describes the development of a platform based on vertically aligned CNTs templated in porous anodic alumina (PAA) for the scalable fabrication of multi-nanotube CNTFETs with surround gates as well as several other nanoelectronic devices. PAA is a template consisting of hexagonally ordered pores that result from the anodization of an Al film. By embedding a catalyst layer within PAA, single-walled CNTs are synthesized from the nanoscale vertical pores (pore diameter ≈20 nm, spacing ≈100 nm) at a yield of no more than one nanotube per pore. After synthesis, the CNTs are contacted within the pores by electrodepositing Pd, a known low-barrier contact metal for CNTs, to form nanowires that electrically address the CNTs near

  3. Lignin-Derived Advanced Carbon Materials

    SciTech Connect

    Chatterjee, Sabornie; Saito, Tomonori

    2015-01-01

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By application specific pretreatments and manufacturing method, lignin can be converted to a variety of value added carbon materials. However, the physical and chemical heterogenitites in lignin complicate its use as a feedstock. In this review, lignin manufacturing process, effects of pretreatments and manufacturing methods on the properties of lignin, properties and applications of various lignin derived carbon materials such as carbon fibers, carbon mats, activated carbons, carbon films; are discussed.

  4. Nonfilling carbon coating of porous silicon micrometer-sized particles for high-performance lithium battery anodes.

    PubMed

    Lu, Zhenda; Liu, Nian; Lee, Hyun-Wook; Zhao, Jie; Li, Weiyang; Li, Yuzhang; Cui, Yi

    2015-03-24

    Silicon is widely recognized as one of the most promising anode materials for lithium-ion batteries due to its 10 times higher specific capacity than graphite. Unfortunately, the large volume change of Si materials during their lithiation/delithiation process results in severe pulverization, loss of electrical contact, unstable solid-electrolyte interphase (SEI), and eventual capacity fading. Although there has been tremendous progress to overcome these issues through nanoscale materials design, improved volumetric capacity and reduced cost are still needed for practical application. To address these issues, we design a nonfilling carbon-coated porous silicon microparticle (nC-pSiMP). In this structure, porous silicon microparticles (pSiMPs) consist of many interconnected primary silicon nanoparticles; only the outer surface of the pSiMPs was coated with carbon, leaving the interior pore structures unfilled. Nonfilling carbon coating hinders electrolyte penetration into the nC-pSiMPs, minimizes the electrode-electrolyte contact area, and retains the internal pore space for Si expansion. SEI formation is mostly limited to the outside of the microparticles. As a result, the composite structure demonstrates excellent cycling stability with high reversible specific capacity (∼1500 mAh g(-1), 1000 cycles) at the rate of C/4. The nC-pSiMPs contain accurate void space to accommodate Si expansion while not losing packing density, which allows for a high volumetric capacity (∼1000 mAh cm(-3)). The areal capacity can reach over 3 mAh cm(-2) with the mass loading 2.01 mg cm(-2). Moreover, the production of nC-pSiMP is simple and scalable using a low-cost silicon monoxide microparticle starting material. PMID:25738223

  5. Enhanced capacity and rate capability of carbon nanotube based anodes with titanium contacts for lithium ion batteries.

    PubMed

    DiLeo, Roberta A; Castiglia, Anthony; Ganter, Matthew J; Rogers, Reginald E; Cress, Cory D; Raffaelle, Ryne P; Landi, Brian J

    2010-10-26

    Carbon nanotubes are being considered for adoption in lithium ion batteries as both a current collector support for high-capacity active materials (replacing traditional metal foils) and as free-standing electrodes where they simultaneously store lithium ions. The necessity to establish good electrical contact to these novel electrode designs is critical for success. In this work, application of nickel and titanium as both separable and thin film electrical contacts to free-standing single-wall carbon nanotube (SWCNT) electrodes is shown to dramatically enhance both the reversible lithium ion capacity and rate capability in comparison with stainless steel. Scanning electron microscopy showed that evaporation of Ni and Ti can effectively coat the SWCNT bundles in a bulk electrode which is capable of providing an improved electrical contact. A thin film of titanium emerged as the preferred electrical contact promoting the highest capacity ever measured for a SWCNT free-standing electrode of 1250 mAh/g. In addition, the titanium contacting approach demonstrated a 5-fold improvement in lithium ion capacity at extraction rates greater than 1C for a high-energy density Ge-SWCNT electrode. The overall performance improvement with Ti contacts is attributed to a lower contact resistance, nanoscale "wetting" of SWCNT bundles to improve contact uniformity, and effective electron coupling between Ti and SWCNTs due to work function-energy level alignment. The experimental results provide the basis for a Ragone analysis (power vs energy parameters), whereby Ge-SWCNT-Ti anodes paired with a LiFePO(4) cathode can lead to a 60% improvement over conventional graphite anodes in both power and energy density for a complete battery. PMID:20857949

  6. Scalable Synthesis of Few-Layer MoS2 Incorporated into Hierarchical Porous Carbon Nanosheets for High-Performance Li- and Na-Ion Battery Anodes.

    PubMed

    Park, Seung-Keun; Lee, Jeongyeon; Bong, Sungyool; Jang, Byungchul; Seong, Kwang-Dong; Piao, Yuanzhe

    2016-08-01

    It is still a challenging task to develop a facile and scalable process to synthesize porous hybrid materials with high electrochemical performance. Herein, a scalable strategy is developed for the synthesis of few-layer MoS2 incorporated into hierarchical porous carbon (MHPC) nanosheet composites as anode materials for both Li- (LIB) and Na-ion battery (SIB). An inexpensive oleylamine (OA) is introduced to not only serve as a hinder the stacking of MoS2 nanosheets but also to provide a conductive carbon, allowing large scale production. In addition, a SiO2 template is adopted to direct the growth of both carbon and MoS2 nanosheets, resulting in the formation of hierarchical porous structures with interconnected networks. Due to these unique features, the as-obtained MHPC shows substantial reversible capacity and very long cycling performance when used as an anode material for LIBs and SIBs, even at high current density. Indeed, this material delivers reversible capacities of 732 and 280 mA h g(-1) after 300 cycles at 1 A g(-1) in LIBs and SIBs, respectively. The results suggest that these MHPC composites also have tremendous potential for applications in other fields. PMID:27406553

  7. Wetting properties of molten carbonate fuel cell electrode materials

    SciTech Connect

    Fisher, J.M.; Bennett, P.S.; Pignon, J.F. ); Makkus, R.C.; Weewer, R.; Hemmes, K. )

    1990-05-01

    Molten carbonate fuel cells (MCFC) are of interest for their potentially highly efficient conversion of chemical energy into electrical energy. This paper discusses how the wetting properties of electrode materials by molten carbonate have a high relevance for the performance of the porous electrodes. When internal reforming of the fuel gas at the anode is performed, the wetting properties also influence the efficiency of the reforming process. Distribution of the electrolyte in an MCFC stack is mainly determined by the wetting properties of the porous MCFC materials, such as electrodes and tile in contact with the electrolyte. The quality of the wet seal areas of the separator plates in an MCFC stack to prevent gas leakage also depends on the wetting properties.

  8. Porous carbon particles derived from natural peanut shells as lithium ion battery anode and its electrochemical properties

    NASA Astrophysics Data System (ADS)

    Cao, Xiaoyu; Chen, Shuangqiang; Wang, Guoxiu

    2014-07-01

    Abandoned peanut shells, a common farm waste, have caused tremendous environmental pollution and huge waste deposits through burned and buried disposal approaches. In targeting to enhance the potential value of peanut shells and discover a new alternative candidate for lithium ion batteries, we adopted an easy to scale-up and highly repeated method to treat fresh and dry peanut shells via acid-treatment and pyrolysis, making porous structures on carbonized peanut shells. The pyrolysis process transformed the peanut shells to porous carbon (PC) materials in a quartz tube furnace at a series of temperatures from 500°C to 700°C in N2 under the condition of 40°C gradient temperatures with a heating rate of 2°C min-1. Scanning electron microscopy (SEM) images show that the irregular porous structures and hundreds of micropores are distributed on the PC materials. The cyclic voltammogram (CV) test and particle size analysis are employed to investigate their characteristics of voltammetry and particle size distribution. PC material obtained at 620°C (PC-620) exhibited good particle distribution, porous structure and less agglomerated particles. When applied as anode materials in lithium ion batteries, the PC-620 electrode displayed the high reversible capacity of 608 mAh g-1. Moreover, the cycling performance of PC-620 was the most stable, with a high Coulombic efficiency of 98.9% at the 20th cycle, demonstrating a reversible capacity of 418 mAh g-1, which is higher than the theoretical capacity of graphite. Most importantly, the PC materials harvested from the wastes of natural resources are turned into valuable electrode materials for the high demand energy storage devices, which can significantly reduce severe environmental pollution and alleviate an energy shortage. [Figure not available: see fulltext.

  9. Ultrafast synthesis of MoS2 or WS2-reduced graphene oxide composites via hybrid microwave annealing for anode materials of lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Youn, Duck Hyun; Jo, Changshin; Kim, Jae Young; Lee, Jinwoo; Lee, Jae Sung

    2015-11-01

    An ultrafast and simple strategy to synthesize metal sulfides (MoS2 and WS2) anchored on reduced graphene oxide (RGO) composites is reported as anode materials for lithium ion batteries (LIBs). Metal sulfide nanocrystals with homogeneous dispersion onto conducting RGO sheets are obtained in only 45 s by hybrid microwave annealing (HMA) method. The synthesized materials, especially MoS2/RGO composite, exhibit a high Li capacity, an excellent rate capability, and a stable cycling performance, comparable to the reported best MS2/carbon composite electrodes. The results highlight the effectiveness of HMA method to fabricate the metal sulfide/RGO composites with excellent electric properties.

  10. Thermal decomposition of alkane hydrocarbons inside a porous Ni anode for fuel supply of direct carbon fuel cell: Effects of morphology and crystallinity of carbon

    NASA Astrophysics Data System (ADS)

    Li, Chengguo; Yi, Hakgyu; Jalalabadi, Tahereh; Lee, Donggeun

    2015-10-01

    This study improved the physical contact between anode and fuel in a direct carbon fuel cell (DCFC) by directly generating carbon in a porous Ni anode through thermal decomposition of three kinds of hydrocarbons (CH4, C2H6, C3H8). From electron microscope observations of the carbon particles generated from each hydrocarbon, carbon spheres (CS), carbon nanotubes (CNT) and carbon nanofibers (CNF) were identified with increasing carbon number. Raman scattering analysis was performed to determine the crystallinity of the carbon samples. As a result, the carbon samples (CS, CNT, and CNF) produced from CH4, C2H6 and C3H8 were found to be less crystalline and more flexible with increasing the carbon number. DCFC performance was measured at 700 °C for the anode fueled with the same mass of the carbon sample. It was found that the 1-dimensional CNT and CNF were more active to produce 148% and 210% times higher power density than the CS. The difference was partly attributed to the finding that the less-crystalline CNT and CNF had much lower charge transfer resistances than the CS. A lifetime test found that the CNT and CNF, which are capable of transporting electrons for much longer periods, maintained the power density much longer, as compared to the CS which can lose their point contacts between the particles shortly at high current density.

  11. Pyrolytic carbon-coated stainless steel felt as a high-performance anode for bioelectrochemical systems.

    PubMed

    Guo, Kun; Hidalgo, Diana; Tommasi, Tonia; Rabaey, Korneel

    2016-07-01

    Scale up of bioelectrochemical systems (BESs) requires highly conductive, biocompatible and stable electrodes. Here we present pyrolytic carbon-coated stainless steel felt (C-SS felt) as a high-performance and scalable anode. The electrode is created by generating a carbon layer on stainless steel felt (SS felt) via a multi-step deposition process involving α-d-glucose impregnation, caramelization, and pyrolysis. Physicochemical characterizations of the surface elucidate that a thin (20±5μm) and homogenous layer of polycrystalline graphitic carbon was obtained on SS felt surface after modification. The carbon coating significantly increases the biocompatibility, enabling robust electroactive biofilm formation. The C-SS felt electrodes reach current densities (jmax) of 3.65±0.14mA/cm(2) within 7days of operation, which is 11 times higher than plain SS felt electrodes (0.30±0.04mA/cm(2)). The excellent biocompatibility, high specific surface area, high conductivity, good mechanical strength, and low cost make C-SS felt a promising electrode for BESs. PMID:27058401

  12. Influence of Treatment Temperature on Microstructure and Properties of YSZ-NiO Anode Materials

    NASA Astrophysics Data System (ADS)

    Podhurska, Viktoriya; Vasyliv, Bogdan; Ostash, Orest; Brodnikovskyi, Yegor; Vasylyev, Oleksandr

    2016-02-01

    The cyclic treatment technique (redox cycling) comprising stages of material exposition in reducing and oxidizing high-temperature environments and intermediate degassing between these stages has been developed to improve the structural integrity of YSZ-NiO ceramic anode substrates for solid oxide fuel cells. A series of specimens were singly reduced in a hydrogenous environment (the Ar-5 vol% H2 mixture or hydrogen of 99.99 vol% H2 purity) under the pressure of 0.15 MPa or subjected to redox cycling at 600 or 800 °C. The influence of redox cycling at the treatment temperatures of 600 and 800 °C on the structure, strength and electrical conductivity of the material has been analysed. Using the treatment temperature 600 °C, a structure providing improved physical and mechanical properties of the material was formed. However, at the treatment temperature 800 °C, an anode structure with an array of microcracks was formed that significantly reduced the strength and electrical conductivity of the material.

  13. Influence of Treatment Temperature on Microstructure and Properties of YSZ-NiO Anode Materials.

    PubMed

    Podhurska, Viktoriya; Vasyliv, Bogdan; Ostash, Orest; Brodnikovskyi, Yegor; Vasylyev, Oleksandr

    2016-12-01

    The cyclic treatment technique (redox cycling) comprising stages of material exposition in reducing and oxidizing high-temperature environments and intermediate degassing between these stages has been developed to improve the structural integrity of YSZ-NiO ceramic anode substrates for solid oxide fuel cells. A series of specimens were singly reduced in a hydrogenous environment (the Ar-5 vol% Н2 mixture or hydrogen of 99.99 vol% H2 purity) under the pressure of 0.15 MPa or subjected to redox cycling at 600 or 800 °C. The influence of redox cycling at the treatment temperatures of 600 and 800 °C on the structure, strength and electrical conductivity of the material has been analysed. Using the treatment temperature 600 °C, a structure providing improved physical and mechanical properties of the material was formed. However, at the treatment temperature 800 °C, an anode structure with an array of microcracks was formed that significantly reduced the strength and electrical conductivity of the material. PMID:26880730

  14. Electrochemical Properties of Chemically Processed SiOx as Coating Material in Lithium-Ion Batteries with Si Anode

    PubMed Central

    Jeong, Hee-June; Yang, Hyeon-Woo; Yun, Kang-Seop; Noh, Eul; Kang, Wooseung

    2014-01-01

    A SiOx coating material for Si anode in lithium-ion battery was processed by using SiCl4 and ethylene glycol. The produced SiOx particles after heat treatment at 725°C for 1 h were porous and irregularly shaped with amorphous structure. Pitch carbon added to SiOx was found to strongly affect solid electrolyte interphase stabilization and cyclic stability. When mixed with an optimal amount of 30 wt% pitch carbon, the SiOx showed a high charge/discharge cyclic stability of about 97% for the 2nd to the 50th cycle. The initial specific capacity of the SiOx was measured to be 1401 mAh/g. On the basis of the evaluation of the SiOx coating material, the process utilized in this study is considered an efficient method to produce SiOx with high performance in an economical way. PMID:25050401

  15. Growth of ultrathin MoS₂ nanosheets with expanded spacing of (002) plane on carbon nanotubes for high-performance sodium-ion battery anodes.

    PubMed

    Zhang, Shen; Yu, Xianbo; Yu, Hailong; Chen, Yujin; Gao, Peng; Li, Chunyan; Zhu, Chunling

    2014-12-24

    A hydrothermal method was developed to grow ultrathin MoS2 nanosheets, with an expanded spacing of the (002) planes, on carbon nanotubes. When used as a sodium-ion battery anode, the composite exhibited a specific capacity of 495.9 mAh g(-1), and 84.8% of the initial capacity was retained after 80 cycles, even at a current density of 200 mA g(-1). X-ray diffraction analyses show that the sodiation/desodiation mechanismis based on a conversion reaction. The high capacity and long-term stability at a high current ate demonstrate that the composite is a very promising candidate for use as an anode material in sodium-ion batteries. PMID:25479568

  16. Improving the microstructure and electrochemical performance of carbon nanofibers containing graphene-wrapped silicon nanoparticles as a Li-ion battery anode

    NASA Astrophysics Data System (ADS)

    Kim, So Yeun; Yang, Kap Seung; Kim, Bo-Hye

    2015-01-01

    A novel anode material for lithium-ion batteries, graphene-wrapped Si nanoparticles (NPs) embedded in carbon composite nanofibers (CCNFs) with G/Si, is fabricated by electrospinning and subsequent thermal treatment. In CCNFs with G/Si, Si NPs are distributed and preserved inside the CNF surface because the graphene wrapping the Si NPs help prevent agglomeration and ensure a good dispersion of Si NPs inside the CNF matrix. 20-GSP prepared from a weight ratio of 20 wt% of G/Si to polyacrylonitrile exhibits stable capacity retention and a reversible capacity of above 600 mAh g-1 up to 100 cycles. The high cycling performance and superior reversible capacity of the 20-GSP anode can be attributed to the one-dimensional nanofibrous structure with non-agglomerated Si NPs in the CNF matrix, which promotes charge transfer, maintains a stable electrical contact, and buffers the Si volume expansion.

  17. Three-dimensional free-standing carbon nanotubes for a flexible lithium-ion battery anode

    NASA Astrophysics Data System (ADS)

    Kang, Chiwon; Cha, Eunho; Baskaran, Rangasamy; Choi, Wonbong

    2016-03-01

    Flexible lithium-ion batteries (LIBs) have received considerable attention as energy sources for wearable electronics. In recent years, much effort has been devoted to study light-weight, robust, and flexible electrodes. However, high areal and volumetric capacities need to be achieved for practical power and energy densities. In this paper, we report the use of three-dimensional (3D) free-standing carbon nanotubes (CNTs) as a current collector-free anode to demonstrate flexible LIBs with enhanced areal and volumetric capacities. High density CNTs grown on copper (Cu) mesh are transferred to a flexible graphene/polyethylene terephthalate film and integrated into a flexible LIB. A fully flexible LIB cell integrated with the 3D CNT anode delivers a high areal capacity of 0.25 mAh cm-2 at 0.1C and shows fairly consistent open circuit voltage under bending. These findings may provide significant advances in the application of flexible LIB based electronic devices.

  18. An improved approach to the construction of air cleaning arrangements for carbon anode plants

    SciTech Connect

    Kuz`min, G.N.; Basov, L.L.; Egorov, S.F.; Post, H.; Sverdlin, V.A.

    1996-10-01

    Carbon anodes for aluminum production are fabricated with coaltar pitch. When pitch is heated up to 200 C volatiles composed of polynuclear aromatic hydrocarbons (PAH) are emitted. Central ventilation with a scrubber at the exit is the usual way of cleaning the air of the working environment.The existing air-cleaning systems are massive, technically complicated, metal consuming and their efficiency is poor. The duct arrangement from the working area to the scrubber cannot guarantee the required reduction of PAH concentration in the working areas and any failure of the system necessitates interruption of the anode production. An improved concept of air cleaning system which includes the same local equipment based on a plasma chemical method is proposed. Experience has shown that air-cleaning efficiency is improved and energy consumption is reduced. This new concept has the following advantages: simplicity, small size and weight and high reliability. Modules can be installed at the source of gas emission with individual air intake system. Due to the high cleaning efficiency of the system, air can be recirculated in working areas or emitted directly to the atmosphere.

  19. An investigation of oxide composite anode materials for lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Liu, Bo

    This thesis is aimed to develop high-capacity, inexpensive, long cycle life and environmentally benign anode for lithium-ion batteries. With those goals in mind, a novel oxide alloy composite materials MO-Sn xCoyCz (MO=GeO2, SnO2, SiO and SiO2) have been proposed and investigated. Mechanical alloying method has been used to synthesize oxide alloy composite anode material. The MO-SnxCo yCz composite has the potential to combine the advantageous properties of both Sn-Co-C (long cycle life) and MO (high capacity) and, thereby, improve the overall electrochemical performance. The as-milled materials were studied by BET, laser particle analyzer, X-ray diffraction (XRD), scanning electron microscope (SEM), pair distribution function (PDF), extended X-ray absorption fine structure (EXAFS). Evaluating from electrochemical performance, tap density, and cost, GeO2 and SiO are the most promising candidates alloyed with Sn-Co-C system. The GeO 2 composite anode shows a reversible capacity over 800 mAh/g with good capacity retention. Furthermore, the 1st cycle coulombic efficiency has been improved up to 80%. Compared with GeO2, SiO has an advantage on the price. A series of composite anode materials of xSiO * (1-x)SnxCoyC z were studied by electrochemical method. The composition of 50 wt.%SiO-50 wt.%Sn30Co30C40 shows the best electrochemical performance. Two different milling methods (ultra high-energy milling and SPEX milling) were employed to prepare the samples. Ultra high-energy milling sample exhibited superior electrochemical performance. Stabilized lithium metallic powder technique is employed on this anode to improve the first cycle coulombic efficiency. Full-cell configuration (Li1.2Ni 0.15Co0.10Mn0.55O2 vs. 50 wt.%SiO-50 wt.% Sn30Co30C40) has been cycled over 200 cycles successfully. The SiO-SnxFeyC z (x : y: z molar ratio) composite has been milled in different compositions. Metallic iron was employed instead of cobalt, which cuts the cost significantly but does not

  20. Improvement of lithium storage performance of Sn-alloy anode materials by a polypyrrole protective layer

    NASA Astrophysics Data System (ADS)

    Peng, Peng; Wen, Zhaoyin; Liu, Yu; Jin, Jun

    2015-01-01

    The SnO2-based anode with improved reversible capacity and cyclability was achieved by employing a protective layer composed of crosslinked polypyrrole nanowires. Scanning electron microscopy measurement was performed to characterize the surface and cross section morphology of electrodes before and after cycling. The crosslinked polypyrrole nanowire protective layer with good elasticity adhered to the SnO2 surface could form a network, leading to buffer the volumetric swelling of active materials during the lithiation/delithiation process. A good cycling stability and an excellent rate capability of the modified electrode were achieved.

  1. Soil as an inexhaustible and high-performance anode material for Li-ion batteries.

    PubMed

    Hu, Xiaofei; Zhang, Kai; Cong, Liang; Cheng, Fangyi; Chen, Jun

    2015-11-11

    Herein, we demonstrate that by a simple treatment of heating and ball-milling, soil is endowed with a 77.2% degree of defects and acts as a high-performance anode material for soil/Li half cells and 18650-type LiNi0.915Co0.075Al0.1O2 (NCA)/soil full batteries that displayed a high and stable capacity of 3200 mA h (corresponding to 176 W h kg(-1) and 522 W h L(-1)) in the 200th cycle at a high current of 4 A. PMID:26372419

  2. Guar gum: Structural and electrochemical characterization of natural polymer based binder for silicon-carbon composite rechargeable Li-ion battery anodes

    NASA Astrophysics Data System (ADS)

    Kuruba, Ramalinga; Datta, Moni Kanchan; Damodaran, Krishnan; Jampani, Prashanth H.; Gattu, Bharat; Patel, Prasad P.; Shanthi, Pavithra M.; Damle, Sameer; Kumta, Prashant N.

    2015-12-01

    Long term cyclability of a composite Li-ion anode electrode comprised of 82 wt.% Si/C lithium ion active material along with 8 wt.% polymeric binder and 10 wt.% Super P conductive carbon black has been studied utilizing polymeric binders exhibiting different elastic/tensile moduli and tensile yield strengths. Accordingly, electrochemically active Si/C composite synthesized by high energy mechanical milling (HEMM), exhibiting reversible specific capacities of ∼780 mAh/g and ∼600 mAh/g at charge/discharge rates of ∼50 mA/g and ∼200 mA/g, respectively were selected as the Li-ion active anode. Polyvinylidene fluoride (PVDF) and purified guar gum (PGG) with reported elastic moduli ∼1000 MPa and ∼3200 MPa, respectively were selected as the binders. Results show that the composite electrode (Si/C + binder + conducting carbon) comprising the higher elastic modulus binder (PGG) exhibits better long term cyclability contrasted with PVDF. 1H-NMR analysis of the polymer before and after cycling shows structural degradation/deformation of the low elastic modulus PVDF, whereas the high elastic modulus PGG binder shows no permanent structural deformation or damage. The results presented herein thus suggest that PGG based polymers exhibiting high elastic modulus are a promising class of binders with the desired mechanical integrity needed for enduring the colossal volume expansion stresses of Si/C based composite anodes.

  3. FeS/C composite as high-performance anode material for alkaline nickel-iron rechargeable batteries

    NASA Astrophysics Data System (ADS)

    Shangguan, Enbo; Li, Fei; Li, Jing; Chang, Zhaorong; Li, Quanmin; Yuan, Xiao-Zi; Wang, Haijiang

    2015-09-01

    FeS and its composite, FeS/C, are synthesized via a simple calcination method followed by a co-precipitation process. The electrochemical properties of the bare FeS and FeS/C composite as anode materials for alkaline nickel-iron batteries are investigated. The results show that the FeS/C-3wt%Bi2O3-mixed electrode delivers a high specific capacity of 325 mAh g-1 at a current density of 300 mA g-1 with a faradaic efficiency of 90.3% and retains 99.2% of the initial capacity after 200 cycles. For the first time, it is demonstrated that even at a discharge rate as high as 1500 mA g-1 (5C) the FeS/C-3wt%Bi2O3-mixed electrode delivers a specific capacity of nearly 230 mAh g-1. SEM results confirm that after 200 discharge-charge cycles, the size of FeS/C particles reduces from 5 to 15 μm to less than 300 nm in diameter and the particles are highly dispersed on the surface of carbon black, which is likely caused by the dissolution-deposition process of Fe(OH)2 and Fe via intermediate iron species. As a result, the FeS/C composite exhibits considerably high charge efficiency, high discharge capacities, excellent rate capability and superior cycling stability. We believe that this composite is a potential candidate of high-performance anode materials for alkaline iron-based rechargeable batteries.

  4. Facile Sol-Gel/Spray-Drying Synthesis of Interweaved Si@TiO2&CNTs Hybrid Microsphere as Superior Anode Materials for Li-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Wang, Jiyun; Hou, Xianhua; Li, Yana; Ru, Qiang; Qin, Haiqing; Hu, Shejun

    2016-07-01

    A unique intertwined structure of silicon-based composite (Si@TiO2&CNTs) has been synthesized by sol-gel and spray drying methods. The Si@TiO2&CNTs is mainly composed of three kinds of materials:the prepared nanosilicon particles, TiO2, and carbon nanotubes (CNTs). A layer of TiO2 particles is found effective for enhancing the electrical conductivity and structure stability of the silicon particles. Additionally, the twisted CNTs are beneficial to build a better conductive network, consequently improving the anode working conditions when the cell is charged or discharged. As a lithium ion battery anode, a specific capacity of approximately 1521 mAh g-1 after 100 cycles is obtained.

  5. Building robust architectures of carbon and metal oxide nanocrystals toward high-performance anodes for lithium-ion batteries.

    PubMed

    Jia, Xilai; Chen, Zheng; Cui, Xia; Peng, Yiting; Wang, Xiaolei; Wang, Ge; Wei, Fei; Lu, Yunfeng

    2012-11-27

    Design and fabrication of effective electrode structure is essential but is still a challenge for current lithium-ion battery technology. Herein we report the design and fabrication of a class of high-performance robust nanocomposites based on iron oxide spheres and carbon nanotubes (CNTs). An efficient aerosol spray process combined with vacuum filtration was used to synthesize such composite architecture, where oxide nanocrystals were assembled into a continuous carbon skeleton and entangled in porous CNT networks. This material architecture offers many critical features that are required for high-performance anodes, including efficient ion transport, high conductivity, and structure durability, therefore enabling an electrode with outstanding lithium storage performance. For example, such an electrode with a thickness of ∼35 μm could deliver a specific capacity of 994 mA h g(-1) (based on total electrode weight) and high recharging rates. This effective strategy can be extended to construct many other composite electrodes for high-performance lithium-ion batteries. PMID:23046380

  6. All-Aqueous Directed Assembly Strategy for Forming High-Capacity, Stable Silicon/Carbon Anodes for Lithium-Ion Batteries.

    PubMed

    Chen, Yanjing; Xu, Mengqing; Zhang, Yuzi; Pan, Yue; Lucht, Brett L; Bose, Arijit

    2015-09-30

    Silicon (Si) particles have emerged as a promising active material for next-generation lithium-ion battery anodes. However, the large volume changes during lithiation/delithiation cycles result in fracture and pulverization of Si, leading to rapid fading of performance. Here, we report a simple, all-aqueous, directed assembly-based strategy to fabricate Si-based anodes that show capacity and capacity retention that are comparable or better than other more complex methods for forming anodes. We use a cationic surfactant, cetyltrimethylammonium bromide (CTAB), to stabilize Si nanoparticles (SiNPs) in water. This suspension is added to an aqueous suspension of para-amino benzoic acid-terminated carbon black (CB), pH 7. Charge interactions cause the well-dispersed SiNP to bind to the CB, allowing most of the SiNP to be available for lithiation and charge transfer. The CB forms a conducting network when the suspension pH is lowered. The dried SiNP/CTAB/CB anode exhibits a capacity of 1580 mAh g(-1) and efficiency of 97.3% after 50 cycles at a rate of 0.1C, and stable performance at cycling rates up to 5C. The directed spatial organization of the SiNP and CB using straightforward colloidal principles allows good contact between the well-dispersed active material and the electrically conducting network. The pore space in the CB network accommodates volume changes in the SiNPs. When CTAB is not used, the SiNPs form aggregates in the suspension, and do not contact the CB effectively. Therefore, the electrochemical performance of the SiNP/CB anode is inferior to that of the SiNP/CTAB/CB anode. This aqueous-based, room temperature, directed assembly technique is a new, but simple, low-cost scalable method to fabricate stable Si-based anodes for lithium-ion batteries with performance characteristics that match those made by other more sophisticated techniques. PMID:26355591

  7. Formation of Diffusion Layers by Anode Plasma Electrolytic Nitrocarburizing of Low-Carbon Steel

    NASA Astrophysics Data System (ADS)

    Kusmanov, S. A.; Kusmanova, Yu. V.; Naumov, A. R.; Belkin, P. N.

    2015-08-01

    The structure of the low-carbon steel after plasma electrolytic nitrocarburizing in the electrolyte containing acetonitrile was investigated. The cross-sectional microstructure, composition, and phase constituents of a modified layer under different processing conditions were characterized. It is shown that the electrolyte that contained ammonium chloride and acetonitrile provides the saturation of steel with nitrogen and carbon and the formation of the Fe4N and FeN0.05 nitrides, Fe4C carbide and other phases. The nitrogen diffusion decreases the austenitization temperature and results in the formation of martensite after the sample cooling in the electrolyte. The formation of a carbon and nitrogen source in a vapor-gas envelope (VGE) is investigated. The proposed mechanism includes evaporation of acetonitrile in the VGE, its adsorption on an anode with the following thermal decomposition, and also the acetonitrile reduction to amine with subsequent hydrolysis to ethanol that is determined with the use of chromatographic method. The aqueous solution that contained 10 wt.% NH4Cl and 10 wt.% CH3CN allows one to obtain the nitrocarburized layer with the thickness of 0.22 mm and microhardness up to 740 HV during 10 min at 850 °C. This treatment regime leads to the decrease in the surface roughness of steel R a from 1.01 μm to 0.17 μm.

  8. Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode

    NASA Astrophysics Data System (ADS)

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; Macfarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g-1 after 50 cycles and with high rate capability, delivering 770 mAh g-1 at 5 A g-1 (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future.

  9. Flagellar filament bio-templated inorganic oxide materials - towards an efficient lithium battery anode.

    PubMed

    Beznosov, Sergei N; Veluri, Pavan S; Pyatibratov, Mikhail G; Chatterjee, Abhijit; MacFarlane, Douglas R; Fedorov, Oleg V; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g(-1) after 50 cycles and with high rate capability, delivering 770 mAh g(-1) at 5 A g(-1) (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future. PMID:25583370

  10. Flagellar filament bio-templated inorganic oxide materials – towards an efficient lithium battery anode

    PubMed Central

    Beznosov, Sergei N.; Veluri, Pavan S.; Pyatibratov, Mikhail G.; Chatterjee, Abhijit; MacFarlane, Douglas R.; Fedorov, Oleg V.; Mitra, Sagar

    2015-01-01

    Designing a new generation of energy-intensive and sustainable electrode materials for batteries to power a variety of applications is an imperative task. The use of biomaterials as a nanosized structural template for these materials has the potential to produce hitherto unachievable structures. In this report, we have used genetically modified flagellar filaments of the extremely halophilic archaea species Halobacterium salinarum to synthesize nanostructured iron oxide composites for use as a lithium-ion battery anode. The electrode demonstrated a superior electrochemical performance compared to existing literature results, with good capacity retention of 1032 mAh g−1 after 50 cycles and with high rate capability, delivering 770 mAh g−1 at 5 A g−1 (~5 C) discharge rate. This unique flagellar filament based template has the potential to provide access to other highly structured advanced energy materials in the future. PMID:25583370

  11. MOF-derived ultrafine MnO nanocrystals embedded in a porous carbon matrix as high-performance anodes for lithium-ion batteries.

    PubMed

    Zheng, Fangcai; Xia, Guoliang; Yang, Yang; Chen, Qianwang

    2015-06-01

    Although MnO has been demonstrated to be a promising anode material for lithium-ion batteries (LIBs) in terms of its high theoretical capacity (755 mA h g(-1)), comparatively low voltage hysteresis (<0.8 V), low cost, and environmental benignity, the application of MnO as a practical electrode material is still hindered by many obstacles, including poor cycling stability and huge volume expansion during the charge/discharge process. Herein, we report a facile and scalable metal-organic framework-derived route for the in situ fabrication of ultrafine MnO nanocrystals encapsulated in a porous carbon matrix, where nanopores increase active sites to store redox ions and enhance ionic diffusivity to encapsulated MnO nanocrystals. As an anode material for lithium-ion batteries (LIBs), these MnO@C composites exhibited a high reversible specific capacity of 1221 mA h g(-1) after 100 cycles at a current density of 100 mA g(-1). The excellent electrochemical performance can be attributed to their unique structure with MnO nanocrystals dispersed uniformly inside a porous carbon matrix, which can largely enhance the electrical conductivity and effectively avoid the aggregation of MnO nanocrystals, and relieve the strain caused by the volumetric change during the charge/discharge process. This facile and economical strategy will extend the scope of metal-organic framework-derived synthesis for other materials in energy storage applications. PMID:25955439

  12. Novel silicon and tin alloy nano-particulate materials via spark erosion for high performance and high capacity anodes in lithium ion batteries

    NASA Astrophysics Data System (ADS)

    White, Emma Marie Hamilton

    The advent and popularity of portable electronics, as well as the need to reduce carbon-based fuel dependence for environmental and economic reasons, has led to the search for higher energy density portable power storage methods. Lithium ion batteries offer the highest energy density of any portable energy storage technology, but their potential is limited by the currently used materials. Theoretical capacities of silicon (3580 mAh/g) and tin (990 mAh/g) are significantly higher than existing graphitic anodes (372 mAh/g). However, silicon and tin must be scaled down to the nano-level to mitigate the pulverization from drastic volume changes in the anode structure during lithium ion insertion/extraction. The available synthesis techniques for silicon and tin nano-particles are complicated and scale-up is costly. A unique one-step process for synthesizing Si-Sn alloy and Sn nano-particles via spark plasma erosion has been developed to achieve the ideal nano-particulate size and carbon coating architecture. Spark erosion produces crystalline and amorphous spherical nano-particles, averaging 5-500nm in diameter. Several tin and silicon alloys have been spark eroded and thoroughly characterized using SEM, TEM, EDS, XPS, Auger spectroscopy, NMR spectroscopy and TGA. The resulting nano-particles show improved performance as anodes over commercialized materials. In particular, pure sparked Sn particles show stable reversible capacity at ˜460 mAh/g with >99.5% coulombic efficiency for over 100 cycles. These particles are drop-in ready for existing commercial anode processing techniques and by only adding 10% of the sparked Sn particles the total current cell capacity will increase by ˜13%.

  13. Pre-lithiation of onion-like carbon/MoS2 nano-urchin anodes for high-performance rechargeable lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Ye; Xing, Guozhong; Han, Zhao Jun; Shi, Yumeng; Wong, Jen It; Huang, Zhi Xiang; Ostrikov, Kostya (Ken); Yang, Hui Ying

    2014-07-01

    Hybrid urchin-like nanostructures composed of a spherical onion-like carbon (OLC) core and MoS2 nanoleaves were synthesized by a simple solvothermal method followed by thermal annealing treatment. Compared to commercial MoS2 powder, MoS2/OLC nanocomposites exhibit enhanced electrochemical performance as anode materials of lithium-ion batteries (LIBs) with a specific capacity of 853 mA h g-1 at a current density of 50 mA g-1 after 60 cycles, and a moderate initial coulombic efficiency of 71.1%. Furthermore, a simple pre-lithiation method based on direct contact of lithium foil with MoS2/OLC nano-urchins was used to achieve a very high coulombic efficiency of 97.6% in the first discharge/charge cycle, which is at least 26% higher compared to that of pristine MoS2/OLC nano-urchins. This pre-lithiation method can be generalized to develop other carbon-metal sulfide nanohybrids for LIB anode materials. These results may open up a new avenue for the development of the next-generation high-performance LIBs.Hybrid urchin-like nanostructures composed of a spherical onion-like carbon (OLC) core and MoS2 nanoleaves were synthesized by a simple solvothermal method followed by thermal annealing treatment. Compared to commercial MoS2 powder, MoS2/OLC nanocomposites exhibit enhanced electrochemical performance as anode materials of lithium-ion batteries (LIBs) with a specific capacity of 853 mA h g-1 at a current density of 50 mA g-1 after 60 cycles, and a moderate initial coulombic efficiency of 71.1%. Furthermore, a simple pre-lithiation method based on direct contact of lithium foil with MoS2/OLC nano-urchins was used to achieve a very high coulombic efficiency of 97.6% in the first discharge/charge cycle, which is at least 26% higher compared to that of pristine MoS2/OLC nano-urchins. This pre-lithiation method can be generalized to develop other carbon-metal sulfide nanohybrids for LIB anode materials. These results may open up a new avenue for the development of the next

  14. Composite of graphite/phosphorus as anode for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Bai, Aojun; Wang, Li; Li, Jiaoyang; He, Xiangming; Wang, Jixian; Wang, Jianlong

    2015-09-01

    Graphite/Phosphorus composite anodes are prepared by mixing graphite and the phosphorus/carbon material, which prepared by heating the mixture of red phosphorus and porous carbon. Their electrochemical performances are evaluated as anodes for Li-ion batteries. A graphite/Phosphorus composite|LiFePO4 full-cell is also attempted. When the phosphorus/carbon content in the composite anode is 28.6 wt.%, the composite anode presents high reversible capacity of 500 mAh g-1 and considerable cycleability comparable to that of graphite anode, showing promising performance.

  15. Core-shell Si/C nanospheres embedded in bubble sheet-like carbon film with enhanced performance as lithium ion battery anodes.

    PubMed

    Li, Wenyue; Tang, Yongbing; Kang, Wenpei; Zhang, Zhenyu; Yang, Xia; Zhu, Yu; Zhang, Wenjun; Lee, Chun-Sing

    2015-03-18

    Due to its high theoretical capacity and low lithium insertion voltage plateau, silicon has been considered one of the most promising anodes for high energy and high power density lithium ion batteries (LIBs). However, its rapid capacity degradation, mainly caused by huge volume changes during lithium insertion/extraction processes, remains a significant challenge to its practical application. Engineering Si anodes with abundant free spaces and stabilizing them by incorporating carbon materials has been found to be effective to address the above problems. Using sodium chloride (NaCl) as a template, bubble sheet-like carbon film supported core-shell Si/C composites are prepared for the first time by a facile magnesium thermal reduction/glucose carbonization process. The capacity retention achieves up to 93.6% (about 1018 mAh g(-1)) after 200 cycles at 1 A g(-1). The good performance is attributed to synergistic effects of the conductive carbon film and the hollow structure of the core-shell nanospheres, which provide an ideal conductive matrix and buffer spaces for respectively electron transfer and Si expansion during lithiation process. This unique structure decreases the charge transfer resistance and suppresses the cracking/pulverization of Si, leading to the enhanced cycling performance of bubble sheet-like composite. PMID:25346141

  16. Uniform carbon layer coated Mn3O4 nanorod anodes with improved reversible capacity and cyclic stability for lithium ion batteries.

    PubMed

    Wang, Changbin; Yin, Longwei; Xiang, Dong; Qi, Yongxin

    2012-03-01

    A facile one-step solvothermal reaction route to large-scale synthesis of carbon homogeneously wrapped manganese oxide (Mn(3)O(4)@C) nanocomposites for anode materials of lithium ion batteries was developed using manganese acetate monohydrate and polyvinylpyrrolidone as precursors and reactants. The synthesized Mn(3)O(4)@C nanocomposites were characterized by X-ray diffraction, field-emission scanning electron microscopy, high resolution transmission electron microscopy, X-ray photoelectron spectroscopy, and Raman spectroscopy. The synthesized tetragonal structured Mn(3)O(4) (space group I41/amd) samples display nanorodlike morphology, with a width of about 200-300 nm and a thickness of about 15-20 nm. It is shown that the carbon layers with a thickness of 5 nm are homogeneously coated on the Mn(3)O(4) nanorods. It is indicated from lithium storage capacity estimation that the Mn(3)O(4)@C samples display enhanced capacity retention on charge/discharge cycling. Even after 50 cycles, the products remains stable capacity of 473 mA h g(-1), which is as much 3.05 times as that of pure Mn(3)O(4) samples. Because of the low-cost, nonpollution, and stable capacity, the carbon homogeneously coated Mn(3)O(4)@C nanocomposites are promising anode material for lithium ion batteries. PMID:22394097

  17. Amorphous Fe2O3 nanoshells coated on carbonized bacterial cellulose nanofibers as a flexible anode for high-performance lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Huang, Yang; Lin, Zixia; Zheng, Mingbo; Wang, Tianhe; Yang, Jiazhi; Yuan, Fanshu; Lu, Xiaoyu; Liu, Lin; Sun, Dongping

    2016-03-01

    A three-dimensional (3D) carbonaceous aerogel derived from biomass bacterial cellulose (BC) is introduced as a flexible framework for iron oxides in Li-ion batteries (LIBs). The 3D carbonized BC (CBC) with highly interconnected nanofibrous structure exhibits good electrical conductivity and mechanical stability. The amorphous Fe2O3 is tightly coated on the nanofibers of CBC through a simple in situ thermal decomposition method. The obtained amorphous Fe2O3 anode (denoted as A-Fe2O3@CBC) exhibits stable cycling performance and high rate capability when assembled into a half-cell, which is supposed to benefit from the well-dispersed Fe2O3 nanoshells and the hierarchical pores in A-Fe2O3@CBC composite. The rational design of the nanostructure could improve the transportation of electrons/ions and effectively alleviate volume changes of Fe2O3 during the electrochemical cycling. Meanwhile, the amorphous nature of the Fe2O3 in anode provides an enhanced capacitive-like lithium storage and flexible structure of the active materials, resulting in much higher specific capacity and longer cycle life when compared with its crystalline counterpart. This work provides a promising approach to design and construct the flexible metal oxide anode materials based on 3D carbonaceous aerogel for high-performance LIBs.

  18. Electrochemical reactions of layered niobate material as novel anode for sodium ion batteries

    NASA Astrophysics Data System (ADS)

    Nakayama, Hideki; Nose, Masafumi; Nakanishi, Shinji; Iba, Hideki

    2015-08-01

    The electrochemical performances of layered niobium oxide materials were investigated for the first time as novel anode active materials for the sodium-ion battery. The layered niobate with the formula KNb3O8 was synthesized by a solid-state reaction and has been evaluated as an anode electrode by a cyclic voltammetry technique and galvanostatic charge/discharge tests. The crystal structure of KNb3O8 contains the NbO6 octahedral units and potassium alkali-metal ions interlayer to form the layered structure. KNb3O8 has a redox reaction around 1 V vs. Na/Na+ and has a reversible capacity of 104 mAh/g corresponding to the 1.7 Na+ insertion/extraction in the KNb3O8 structure. The Nb K-edge X-ray absorption near edge structure (XANES) shows that the Nb oxidation state is converted from Nb5+ to Nb4+ during the Na+ insertion stage, and reversibly recovered to Nb5+ during the Na+ extraction stage. This is the first report that the layered niobate of KNb3O8 reversibly reacts with Na+ at the potential around 1 V vs. Na/Na+ via the Nb5+/4+ redox reaction.

  19. Boron doped defective graphene as a potential anode material for Li-ion batteries.

    PubMed

    Hardikar, Rahul P; Das, Deya; Han, Sang Soo; Lee, Kwang-Ryeol; Singh, Abhishek K

    2014-08-21

    Graphene with large surface area and robust structure has been proposed as a high storage capacity anode material for Li ion batteries. While the inertness of pristine graphene leads to better Li kinetics, poor adsorption leads to Li clustering, significantly affecting the performance of the battery. Here, we show the role of defects and doping in achieving enhanced adsorption without compromising on the high diffusivity of Li. Using first principles density functional theory (DFT) calculations, we carry out a comprehensive study of diffusion kinetics of Li over the plane of the defective structures and calculate the change in the number of Li atoms in the vicinity of defects, with respect to pristine graphene. Our results show that the Li-C interaction, storage capacity and the energy barriers depend sensitively on the type of defects. The un-doped and boron doped mono-vacancy, doped di-vacancy up to two boron, one nitrogen doped di-vacancy, and Stone-Wales defects show low energy barriers that are comparable to pristine graphene. Furthermore, boron doping at mono-vacancy enhances the adsorption of Li. In particular, the two boron doped mono-vacancy graphene shows both a low energy barrier of 0.31 eV and better adsorption, and hence can be considered as a potential candidate for anode material. PMID:24986702

  20. Heat-treated stainless steel felt as scalable anode material for bioelectrochemical systems.

    PubMed

    Guo, Kun; Soeriyadi, Alexander H; Feng, Huajun; Prévoteau, Antonin; Patil, Sunil A; Gooding, J Justin; Rabaey, Korneel

    2015-11-01

    This work reports a simple and scalable method to convert stainless steel (SS) felt into an effective anode for bioelectrochemical systems (BESs) by means of heat treatment. X-ray photoelectron spectroscopy and cyclic voltammetry elucidated that the heat treatment generated an iron oxide rich layer on the SS felt surface. The iron oxide layer dramatically enhanced the electroactive biofilm formation on SS felt surface in BESs. Consequently, the sustained current densities achieved on the treated electrodes (1 cm(2)) were around 1.5±0.13 mA/cm(2), which was seven times higher than the untreated electrodes (0.22±0.04 mA/cm(2)). To test the scalability of this material, the heat-treated SS felt was scaled up to 150 cm(2) and similar current density (1.5 mA/cm(2)) was achieved on the larger electrode. The low cost, straightforwardness of the treatment, high conductivity and high bioelectrocatalytic performance make heat-treated SS felt a scalable anodic material for BESs. PMID:26112346

  1. First-Principles Study of Phosphorene and Graphene Heterostructure as Anode Materials for Rechargeable Li Batteries.

    PubMed

    Guo, Gen-Cai; Wang, Da; Wei, Xiao-Lin; Zhang, Qi; Liu, Hao; Lau, Woon-Ming; Liu, Li-Min

    2015-12-17

    There is a great desire to develop the high-efficient anodes materials for Li batteries, which require not only large capacity but also high stability and mobility. In this work, the phosphorene/graphene heterostructure (P/G) was carefully explored based on first-principles calculations. The binding energy of Li on the pristine phosphorene is relatively weak (within 1.9 eV), whereas the phosphorene/graphene heterostructure (P/G) can greatly improve the binding energy (2.6 eV) without affecting the high mobility of Li within the layers. The electronic structures show that the large Li adsorption energy and fast diffusion ability of the P/G origin from the interfacial synergy effect. Interestingly, the P/G also displays ultrahigh stiffness (Cac = 350 N/m, Czz = 464 N/m), which can effectively avoid the distortion of the pristine phosphorene after the insertion of lithium. Thus, P/G can greatly enhance the cycle life of the battery. Owing to the high capacity, good conductivity, excellent Li mobility, and ultrahigh stiffness, P/G is a very promising anode material in Li-ion batteries (LIBs). PMID:26623923

  2. Prelithiation of silicon-carbon nanotube anodes for lithium ion batteries by stabilized lithium metal powder (SLMP).

    PubMed

    Forney, Michael W; Ganter, Matthew J; Staub, Jason W; Ridgley, Richard D; Landi, Brian J

    2013-09-11

    Stabilized lithium metal powder (SLMP) has been applied during battery assembly to effectively prelithiate high capacity (1500-2500 mAh/g) silicon-carbon nanotube (Si-CNT) anodes, eliminating the 20-40% first cycle irreversible capacity loss. Pressure-activation of SLMP is shown to enhance prelithiation and enable capacity matching between Si-CNT anodes and lithium nickel cobalt aluminum oxide (NCA) cathodes in full batteries with minimal added mass. The prelithiation approach enables high energy density NCA/Si-CNT batteries achieving >1000 cycles at 20% depth-of-discharge. PMID:23902472

  3. Chemical Bonding In Amorphous Si Coated-carbon Nanotube As Anodes For Li ion Batteries: A XANES Study

    SciTech Connect

    Zhou, Jigang; Hu, Yongfeng; Li, Xiaolin; Wang, Chong M.; Zuin, Lucia

    2014-03-11

    The chemical bonding nature and its evolution upon electrochemical cycling in amorphous Si coated-carbon nanotube (Si-CNT) anode has been investigated using comprehensive X-ray absorption spectroscopy (XANES) at Si L- and K-edges along with C and O K-edges. The Si nanolayer on CNT is found to be anchored to CNT via Si-O-C bonding. This bond weakens upon electrochemical cycling accompanied with generation of Li2CO3 on the surface of Si-CNT. Those findings are crucial in designing further improved Si-C composite anode for lithium ion battery.

  4. Anodic composite deposition of RuO2/reduced graphene oxide/carbon nanotube for advanced supercapacitors

    NASA Astrophysics Data System (ADS)

    Hu, Chi-Chang; Wang, Chia-Wei; Chang, Kuo-Hsin; Chen, Ming-Guan

    2015-07-01

    Anodic composite deposition is demonstrated to be a unique method for fabricating a ternary ruthenium dioxide/reduced graphene oxide/carbon nanotube (RuO2 · xH2O/rGO/CNT, denoted as RGC) nanocomposite onto Ti as an advanced electrode material for supercapacitors. The rGO/CNT composite in RGCs acts as a conductive backbone to facilitate the electron transport between current collector and RuO2 · xH2O nanoparticles (NPs), revealed by the high total specific capacitance (CS,T = 808 F g-1) of RGC without annealing. The contact resistance among RuO2 · xH2O NPs is improved by low-temperature annealing at 150 °C (RGC-150), which renders slight sintering and enhances the specific capacitance of RuO2 · xH2O to achieve 1200 F g-1. The desirable nanocomposite microstructure of RGC-150 builds up the smooth pathways of both protons and electrons to access the active oxy-ruthenium species. This nanocomposite exhibits an extremely high CS,T of 973 F g-1 at 25 mV s-1 (much higher than 435 F g-1 of an annealed RuO2 · xH2O deposit) and good capacitance retention (60.5% with scan rate varying from 5 to 500 mV s-1), revealing an advanced electrode material for high-performance supercapacitors.

  5. Lignin-Derived Advanced Carbon Materials

    DOE PAGESBeta

    Chatterjee, Sabornie; Saito, Tomonori

    2015-11-16

    Lignin is a highly abundant source of renewable carbon that can be considered as a valuable sustainable source of biobased materials. By applying specific pretreatments and manufacturing methods, it has been found that lignin can be converted into a variety of value-added carbon materials. However, the physical and chemical heterogeneities of lignin complicate its use as a feedstock. Herein, we discuss the lignin manufacturing process, the effects of pretreatments and manufacturing methods on the properties of product lignin, and structure–property relationships in various applications of lignin-derived carbon materials, such as carbon fibers, carbon mats, activated carbons, carbon films, and templatedmore » carbon.« less

  6. Determination of carbonate carbon in geological materials by coulometric titration

    USGS Publications Warehouse

    Engleman, E.E.; Jackson, L.L.; Norton, D.R.

    1985-01-01

    A coulometric titration is used for the determination of carbonate carbon in geological materials. Carbon dioxide is evolved from the sample by the addition of 2 M perchloric acid, with heating, and is determined by automated coulometric titration. The coulometric titration showed improved speed and precision with comparable accuracy to gravimetric and gasometric techniques. ?? 1985.

  7. Microscopic properties of lithium, sodium, and magnesium battery anode materials related to possible dendrite growth

    SciTech Connect

    Jäckle, Markus; Groß, Axel

    2014-11-07

    Lithium and magnesium exhibit rather different properties as battery anode materials with respect to the phenomenon of dendrite formation which can lead to short-circuits in batteries. Diffusion processes are the key to understanding structure forming processes on surfaces. Therefore, we have determined adsorption energies and barriers for the self-diffusion on Li and Mg using periodic density functional theory calculations and contrasted the results to Na which is also regarded as a promising electrode material in batteries. According to our calculations, magnesium exhibits a tendency towards the growth of smooth surfaces as it exhibits lower diffusion barriers than lithium and sodium, and as an hcp metal it favors higher-coordinated configurations in contrast to the bcc metals Li and Na. These characteristic differences are expected to contribute to the unequal tendencies of these metals with respect to dendrite growth.

  8. Short time proton dynamics in bulk ice and in porous anode solid oxide fuel cell materials

    SciTech Connect

    Basoli, Francesco; Senesi, Roberto; Kolesnikov, Alexander I; Licoccia, Silvia

    2014-01-01

    Oxygen reduction and incorporation into solid electrolytes and the reverse reaction of oxygen evolution play a cru-cial role in Solid Oxide Fuel Cell (SOFC) applications. However a detailed un derstanding of the kinetics of the cor-responding reactions, i.e. on reaction mechanisms, rate limiting steps, reaction paths, electrocatalytic role of materials, is still missing. These include a thorough characterization of the binding potentials experienced by protons in the lattice. We report results of Inelastic Neutron Scattering (INS) measurements of the vibrational state of the protons in Ni- YSZ highly porous composites (75% to 90% ), a ceramic-metal material showing a high electrical conductivity and ther mal stability, which is known to be most effectively used as anodes for solid ox ide fuel cells. The results are compared with INS and Deep Inelastic Neutron Scattering (DINS) experiments on the proton binding states in bulk ice.

  9. 2D Electrides as Promising Anode Materials for Na-Ion Batteries from First-Principles Study.

    PubMed

    Hu, Junping; Xu, Bo; Yang, Shengyuan A; Guan, Shan; Ouyang, Chuying; Yao, Yugui

    2015-11-01

    Searching for suitable anodes with good performance is a key challenge for rechargeable Na-ion batteries (NIBs). Using the first-principles method, we predict that 2D nitrogen electride materials can be served as anode materials for NIBs. Particularly, we show that Ca2N meets almost all the requirements of a good NIB anode. Each formula unit of a monolayer Ca2N sheet can absorb up to four Na atoms, corresponding to a theoretical specific capacity of 1138 mAh·g(-1). The metallic character for both pristine Ca2N and its Na intercalated state NaxCa2N ensures good electronic conduction. Na diffusion along the 2D monolayer plane can be very fast even at room temperature, with a Na migration energy barrier as small as 0.084 eV. These properties are key to the excellent rate performance of an anode material. The average open-circuit voltage is calculated to be 0.18 V vs Na/Na(+) for the chemical stoichiometry of Na2Ca2N and 0.09 V for Na4Ca2N. The relatively low average open-circuit voltage is beneficial to the overall voltage of the cell. In addition, the 2D monolayers have very small lattice change upon Na intercalation, which ensures a good cycling stability. All these results demonstrate that the Ca2N monolayer could be an excellent anode material for NIBs. PMID:26461467

  10. Boosting the local anodic oxidation of silicon through carbon nanofiber atomic force microscopy probes

    PubMed Central

    Lorenzoni, Matteo; Matsui, Soichiro; Tanemura, Masaki; Perez-Murano, Francesc

    2015-01-01

    Summary Many nanofabrication methods based on scanning probe microscopy have been developed during the last decades. Local anodic oxidation (LAO) is one of such methods: Upon application of an electric field between tip and surface under ambient conditions, oxide patterning with nanometer-scale resolution can be performed with good control of dimensions and placement. LAO through the non-contact mode of atomic force microscopy (AFM) has proven to yield a better resolution and tip preservation than the contact mode and it can be effectively performed in the dynamic mode of AFM. The tip plays a crucial role for the LAO-AFM, because it regulates the minimum feature size and the electric field. For instance, the feasibility of carbon nanotube (CNT)-functionalized tips showed great promise for LAO-AFM, yet, the fabrication of CNT tips presents difficulties. Here, we explore the use of a carbon nanofiber (CNF) as the tip apex of AFM probes for the application of LAO on silicon substrates in the AFM amplitude modulation dynamic mode of operation. We show the good performance of CNF-AFM probes in terms of resolution and reproducibility, as well as demonstration that the CNF apex provides enhanced conditions in terms of field-induced, chemical process efficiency. PMID:25671165

  11. Characterization of anode stub corrosion in Hall reduction cells

    SciTech Connect

    Wang, X.; Peterson, R.D.

    1996-10-01

    Mild steel is widely used as a structural material in the aluminum smelting industry. In prebaked-anode reduction cells, the stability of the steel used as an anode stub against high temperature oxidation and corrosion is very important with regard to its full service life and maintaining aluminum purity. This paper deals with the accelerated corrosion of the steel material used as anode stubs in the presence of the sulfur-containing anode gases. Oxidized scale and the interface region of the oxidation reaction zone in a stub from a reduction cell were fully examined using SEM and X-ray diffraction. The sulfur from the bath and the anode carbon, released as SO{sub 2}, plays an important role in accelerating the anode stub corrosion process. A sulfidation-oxidation corrosion mechanism is proposed to support the corrosion phenomena observed on the steel anode pieces.

  12. Pyrite (FeS2) nanocrystals as inexpensive high-performance lithium-ion cathode and sodium-ion anode materials.

    PubMed

    Walter, Marc; Zünd, Tanja; Kovalenko, Maksym V

    2015-05-28

    In light of the impeding depletion of fossil fuels and necessity to lower carbon dioxide emissions, economically viable high-performance batteries are urgently needed for numerous applications ranging from electric cars to stationary large-scale electricity storage. Due to its low raw material cost, non-toxicity and potentially high charge-storage capacity pyrite (FeS2) is a highly promising material for such next-generation batteries. In this work we present the electrochemical performance of FeS2 nanocrystals (NCs) as lithium-ion and sodium-ion storage materials. First, we show that nanoscopic FeS2 is a promising lithium-ion cathode material, delivering a capacity of 715 mA h g(-1) and average energy density of 1237 Wh kg(-1) for 100 cycles, twice higher than for commonly used LiCoO2 cathodes. Then we demonstrate, for the first time, that FeS2 NCs can serve as highly reversible sodium-ion anode material with long cycling life. As sodium-ion anode material, FeS2 NCs provide capacities above 500 mA h g(-1) for 400 cycles at a current rate of 1000 mA g(-1). In all our tests and control experiments, the performance of chemically synthesized nanoscale FeS2 clearly surpasses bulk FeS2 as well as large number of other nanostructured metal sulfides. PMID:25941034

  13. FLUORINE CELL ANODE ASSEMBLY

    DOEpatents

    Cable, R.E.; Goode, W.B. Jr.; Henderson, W.K.; Montillon, G.H.

    1962-06-26

    An improved anode assembly is deslgned for use in electrolytlc cells ln the productlon of hydrogen and fluorlne from a moIten electrolyte. The anode assembly comprises a copper post, a copper hanger supported by the post, a plurality of carbon anode members, and bolt means for clamplng half of the anode members to one slde of the hanger and for clamplng the other half of the anode members to the other slde of the hanger. The heads of the clamplng bolts are recessed withln the anode members and carbon plugs are inserted ln the recesses above the bolt heads to protect the boIts agalnst corroslon. A copper washer is provided under the head of each clamplng boIt such that the anode members can be tightly clamped to the hanger with a resultant low anode jolnt resistance. (AEC)

  14. Could Borophene Be Used as a Promising Anode Material for High-Performance Lithium Ion Battery?

    PubMed

    Zhang, Yang; Wu, Zhi-Feng; Gao, Peng-Fei; Zhang, Sheng-Li; Wen, Yu-Hua

    2016-08-31

    The rapid development of electronic products has inspired scientists to design and explore novel electrode materials with an ultrahigh rate of charging/discharging capability, such as two-dimensional (2-D) nanostructures of graphene and MoS2. In this study, another 2-D nanosheet, that is a borophene layer, has been predicted to be utilized as a promising anode material for high-performance Li ion battery based on density functional theory calculations. Our study has revealed that Li atom can combine strongly with borophene surface strongly and easily, and exist as a pure Li(+) state. A rather small energy barrier (0.007 eV) of Li diffusion leads to an ultrahigh diffusivity along an uncorrugated direction of borophene, which is estimated to be 10(4) (10(5)) times faster than that on MoS2 (graphene) at room temperature. A high Li storage capacity of 1239 mA·h/g can be achieved when Li content reaches 0.5. A low average operating voltage of 0.466 V and metallic properties result in that the borophene can be used as a possible anode material. Moreover, the properties of Li adsorption and diffusion on the borophene affected by Ag (111) substrate have been studied. It has been found that the influence of Ag (111) substrate is very weak. Li atom can still bind on the borophene with a strong binding energy of -2.648 eV. A small energy barrier of 0.033 eV can be retained for Li diffusion along the uncorrugated direction, which can give rise to a high Li diffusivity. Besides, the performances of borophene-based Na ion battery have been explored. Our results suggest that an extremely high rate capability could be expected in borophene-based Li ion battery. PMID:27487298

  15. Spongelike Nanosized Mn3O4 as a High-Capacity Anode Material for Rechargeable Lithium Batteries

    SciTech Connect

    Gao, Jie; Lowe, Michael A.; Abruna, Hector D.

    2011-07-12

    Mn₃O₄ has been investigated as a high-capacity anode material for rechargeable lithium ion batteries. Spongelike nanosized Mn₃O₄ was synthesized by a simple precipitation method and characterized by powder X-ray diffraction, Raman scattering and scanning electron microscopy. Its electrochemical performance, as an anode material, was evaluated by galvanostatic discharge–charge tests. The results indicate that this novel type of nanosized Mn₃O₄ exhibits a high initial reversible capacity (869 mA h/g) and significantly enhanced first Coulomb efficiency with a stabilized reversible capacity of around 800 mA h/g after over 40 charge/discharge cycles.

  16. A high power density miniaturized microbial fuel cell having carbon nanotube anodes

    NASA Astrophysics Data System (ADS)

    Ren, Hao; Pyo, Soonjae; Lee, Jae-Ik; Park, Tae-Jin; Gittleson, Forrest S.; Leung, Frederick C. C.; Kim, Jongbaeg; Taylor, André D.; Lee, Hyung-Sool; Chae, Junseok

    2015-01-01

    Microbial fuel cells (MFCs) are a promising technology capable of directly converting the abundant biomass on the planet into electricity. Prior studies have adopted a variety of nanostructured materials with high surface area to volume ratio (SAV), yet the current and power density of these nanostructured materials do not deliver a significant leap over conventional MFCs. This study presents a novel approach to implement a miniaturized MFC with a high SAV of 4000 m-1 using three different CNT-based electrode materials: Vertically Aligned CNT (VACNT), Randomly Aligned CNT (RACNT), and Spin-Spray Layer-by-Layer (SSLbL) CNT. These CNT-based electrodes show unique biofilm morphology and thickness. The study of performance parameters of miniaturized MFCs with these CNT-electrodes are conducted with respect to a control bare gold electrode. The results show that CNT-based materials attract more exoelectrogens, Geobacter sp., than bare gold, yielding thicker biofilm formation. Among CNT-based electrodes, low sheet resistance electrodes result in thick biofilm generation and high current/power density. The miniaturized MFC having an SSLbL CNT anode exhibits a high volumetric power density of 3320 W m-3. This research may help lay the foundation for future research involving the optimization of MFCS with 2D and 3D nanostructured electrodes.

  17. Harvesting energy from the marine sediment-water interface II. Kinetic activity of anode materials.

    PubMed

    Lowy, Daniel A; Tender, Leonard M; Zeikus, J Gregory; Park, Doo Hyun; Lovley, Derek R

    2006-05-15

    Here, we report a comparative study on the kinetic activity of various anodes of a recently described microbial fuel cell consisting of an anode imbedded in marine sediment and a cathode in overlying seawater. Using plain graphite anodes, it was demonstrated that a significant portion of the anodic current results from oxidation of sediment organic matter catalyzed by microorganisms colonizing the anode and capable of directly reducing the anode without added exogenous electron-transfer mediators. Here, graphite anodes incorporating microbial oxidants are evaluated in the laboratory relative to plain graphite with the goal of increasing power density by increasing current density. Anodes evaluated include graphite modified by adsorption of anthraquinone-1,6-disulfonic acid (AQDS) or 1,4-naphthoquinone (NQ), a graphite-ceramic composite containing Mn2+ and Ni2+, and graphite modified with a graphite paste containing Fe3O4 or Fe3O4 and Ni2+. It was found that these anodes possess between 1.5- and 2.2-fold greater kinetic activity than plain graphite. Fuel cells were deployed in a coastal site near Tuckerton, NJ (USA) that utilized two of these anodes. These fuel cells generated ca. 5-fold greater current density than a previously characterized fuel cell equipped with a plain graphite anode, and operated at the same site. PMID:16574400

  18. Solid oxide fuel cell bi-layer anode with gadolinia-doped ceria for utilization of solid carbon fuel

    NASA Astrophysics Data System (ADS)

    Kellogg, Isaiah D.; Koylu, Umit O.; Dogan, Fatih

    Pyrolytic carbon was used as fuel in a solid oxide fuel cell (SOFC) with a yttria-stabilized zirconia (YSZ) electrolyte and a bi-layer anode composed of nickel oxide gadolinia-doped ceria (NiO-GDC) and NiO-YSZ. The common problems of bulk shrinkage and emergent porosity in the YSZ layer adjacent to the GDC/YSZ interface were avoided by using an interlayer of porous NiO-YSZ as a buffer anode layer between the electrolyte and the NiO-GDC primary anode. Cells were fabricated from commercially available component powders so that unconventional production methods suggested in the literature were avoided, that is, the necessity of glycine-nitrate combustion synthesis, specialty multicomponent oxide powders, sputtering, or chemical vapor deposition. The easily-fabricated cell was successfully utilized with hydrogen and propane fuels as well as carbon deposited on the anode during the cyclic operation with the propane. A cell of similar construction could be used in the exhaust stream of a diesel engine to capture and utilize soot for secondary power generation and decreased particulate pollution without the need for filter regeneration.

  19. A SnO2-samarium doped ceria additional anode layer in a direct carbon fuel cell

    NASA Astrophysics Data System (ADS)

    Yu, Baolong; Zhao, Yicheng; Li, Yongdan

    2016-02-01

    The role of a SnO2-samarium doped ceria (SDC) additional anode layer in a direct carbon fuel cell (DCFC) with SDC-(Li0.67Na0.33)2CO3 composite electrolyte and lithiated NiO-SDC-(Li0.67Na0.33)2CO3 composite cathode is investigated and compared with a NiO-SDC extra anode layer. Catalytic grown carbon fiber mixed with (Li0.67Na0.33)2CO3 is used as a fuel. At 750 °C, the maximum power outputs of 192 and 143 mW cm-2 are obtained by the cells with SnO2-SDC and NiO-SDC layers, respectively. In the SnO2-SDC layer, the reduction of SnO2 and the oxidation of Sn happen simultaneously during the cell operation, and the Sn/SnO2 redox cycle provides an additional route for fuel conversion. The formation of an insulating dense interlayer between the anode and electrolyte layers, which usually happens in DCFCs with metal anodes, is avoided in the cell with the SnO2-SDC layer, and the stability of the cell is improved consequently.

  20. Method of making carbon nanotube composite materials

    DOEpatents

    O'Bryan, Gregory; Skinner, Jack L; Vance, Andrew; Yang, Elaine Lai; Zifer, Thomas

    2014-05-20

    The present invention is a method of making a composite polymeric material by dissolving a vinyl thermoplastic polymer, un-functionalized carbon nanotubes and hydroxylated carbon nanotubes and optionally additives in a solvent to make a solution and removing at least a portion of the solvent after casting onto a substrate to make thin films. The material has enhanced conductivity properties due to the blending of the un-functionalized and hydroxylated carbon nanotubes.

  1. Membranes of MnO Beading in Carbon Nanofibers as Flexible Anodes for High-Performance Lithium-Ion Batteries

    NASA Astrophysics Data System (ADS)

    Zhao, Xin; Du, Yuxuan; Jin, Lei; Yang, Yang; Wu, Shuilin; Li, Weihan; Yu, Yan; Zhu, Yanwu; Zhang, Qinghua

    2015-09-01

    Freestanding yet flexible membranes of MnO/carbon nanofibers are successfully fabricated through incorporating MnO2 nanowires into polymer solution by a facile electrospinning technique. During the stabilization and carbonization processes of the as-spun membranes, MnO2 nanowires are transformed to MnO nanoparticles coincided with a conversion of the polymer from an amorphous state to a graphitic structure of carbon nanofibers. The hybrids consist of isolated MnO nanoparticles beading in the porous carbon and demonstrate superior performance when being used as a binder-free anode for lithium-ion batteries. With an optimized amount of MnO (34.6 wt%), the anode exhibits a reversible capacity of as high as 987.3 mAh g-1 after 150 discharge/charge cycles at 0.1 A g-1, a good rate capability (406.1 mAh g-1 at 3  A g-1) and an excellent cycling performance (655 mAh g-1 over 280 cycles at 0.5 A g-1). Furthermore, the hybrid anode maintains a good electrochemical performance at bending state as a flexible electrode.

  2. Membranes of MnO Beading in Carbon Nanofibers as Flexible Anodes for High-Performance Lithium-Ion Batteries

    PubMed Central

    Zhao, Xin; Du, Yuxuan; Jin, Lei; Yang, Yang; Wu, Shuilin; Li, Weihan; Yu, Yan; Zhu, Yanwu; Zhang, Qinghua

    2015-01-01

    Freestanding yet flexible membranes of MnO/carbon nanofibers are successfully fabricated through incorporating MnO2 nanowires into polymer solution by a facile electrospinning technique. During the stabilization and carbonization processes of the as-spun membranes, MnO2 nanowires are transformed to MnO nanoparticles coincided with a conversion of the polymer from an amorphous state to a graphitic structure of carbon nanofibers. The hybrids consist of isolated MnO nanoparticles beading in the porous carbon and demonstrate superior performance when being used as a binder-free anode for lithium-ion batteries. With an optimized amount of MnO (34.6 wt%), the anode exhibits a reversible capacity of as high as 987.3 mAh g−1 after 150 discharge/charge cycles at 0.1 A g−1, a good rate capability (406.1 mAh g−1 at 3  A g−1) and an excellent cycling performance (655 mAh g−1 over 280 cycles at 0.5 A g−1). Furthermore, the hybrid anode maintains a good electrochemical performance at bending state as a flexible electrode. PMID:26374601

  3. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    NASA Astrophysics Data System (ADS)

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M.; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M.

    2016-06-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm2, a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging.

  4. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability.

    PubMed

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm(2). The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm(2), a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  5. High Area Capacity Lithium-Sulfur Full-cell Battery with Prelitiathed Silicon Nanowire-Carbon Anodes for Long Cycling Stability

    PubMed Central

    Krause, Andreas; Dörfler, Susanne; Piwko, Markus; Wisser, Florian M.; Jaumann, Tony; Ahrens, Eike; Giebeler, Lars; Althues, Holger; Schädlich, Stefan; Grothe, Julia; Jeffery, Andrea; Grube, Matthias; Brückner, Jan; Martin, Jan; Eckert, Jürgen; Kaskel, Stefan; Mikolajick, Thomas; Weber, Walter M.

    2016-01-01

    We show full Li/S cells with the use of balanced and high capacity electrodes to address high power electro-mobile applications. The anode is made of an assembly comprising of silicon nanowires as active material densely and conformally grown on a 3D carbon mesh as a light-weight current collector, offering extremely high areal capacity for reversible Li storage of up to 9 mAh/cm2. The dense growth is guaranteed by a versatile Au precursor developed for homogenous Au layer deposition on 3D substrates. In contrast to metallic Li, the presented system exhibits superior characteristics as an anode in Li/S batteries such as safe operation, long cycle life and easy handling. These anodes are combined with high area density S/C composite cathodes into a Li/S full-cell with an ether- and lithium triflate-based electrolyte for high ionic conductivity. The result is a highly cyclable full-cell with an areal capacity of 2.3 mAh/cm2, a cyclability surpassing 450 cycles and capacity retention of 80% after 150 cycles (capacity loss <0.4% per cycle). A detailed physical and electrochemical investigation of the SiNW Li/S full-cell including in-operando synchrotron X-ray diffraction measurements reveals that the lower degradation is due to a lower self-reduction of polysulfides after continuous charging/discharging. PMID:27319783

  6. Pre-lithiation of onion-like carbon/MoS2 nano-urchin anodes for high-performance rechargeable lithium ion batteries.

    PubMed

    Wang, Ye; Xing, Guozhong; Han, Zhao Jun; Shi, Yumeng; Wong, Jen It; Huang, Zhi Xiang; Ostrikov, Kostya Ken; Yang, Hui Ying

    2014-08-01

    Hybrid urchin-like nanostructures composed of a spherical onion-like carbon (OLC) core and MoS2 nanoleaves were synthesized by a simple solvothermal method followed by thermal annealing treatment. Compared to commercial MoS2 powder, MoS2/OLC nanocomposites exhibit enhanced electrochemical performance as anode materials of lithium-ion batteries (LIBs) with a specific capacity of 853 mA h g(-1) at a current density of 50 mA g(-1) after 60 cycles, and a moderate initial coulombic efficiency of 71.1%. Furthermore, a simple pre-lithiation method based on direct contact of lithium foil with MoS2/OLC nano-urchins was used to achieve a very high coulombic efficiency of 97.6% in the first discharge/charge cycle, which is at least 26% higher compared to that of pristine MoS2/OLC nano-urchins. This pre-lithiation method can be generalized to develop other carbon-metal sulfide nanohybrids for LIB anode materials. These results may open up a new avenue for the development of the next-generation high-performance LIBs. PMID:24962690

  7. Novel Carbon-Encapsulated Porous SnO2 Anode for Lithium-Ion Batteries with Much Improved Cyclic Stability.

    PubMed

    Huang, Bin; Li, Xinhai; Pei, Yi; Li, Shuang; Cao, Xi; Massé, Robert C; Cao, Guozhong

    2016-04-01

    Porous SnO2 submicrocubes (SMCs) are synthesized by annealing and HNO3 etching of CoSn(OH)6 SMCs. Bare SnO2 SMCs, as well as bare commercial SnO2 nanoparticles (NPs), show very high initial discharge capacity when used as anode material for lithium-ion batteries. However, during the following cycles most of the Li ions previously inserted cannot be extracted, resulting in considerable irreversibility. Porous SnO2 cubes have been proven to possess better electrochemical performance than the dense nanoparticles. After being encapsulated by carbon shell, the obtained yolk-shell SnO2 SMCs@C exhibits significantly enhanced reversibility for lithium-ions storage. The reversibility of the conversion between SnO2 and Sn, which is largely responsible for the enhanced capacity, has been discussed. The porous SnO2 SMCs@C shows much increased capacity and cycling stability, demonstrating that the porous SnO2 core is essential for better lithium-ion storage performance. The strategy introduced in this paper can be used as a versatile way to fabrication of various metal-oxide-based composites. PMID:26882498

  8. SiC@Si core-shell nanowires on carbon paper as a hybrid anode for lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Wang, Wei; Wang, Yewu; Gu, Lin; Lu, Ren; Qian, Haolei; Peng, Xinsheng; Sha, Jian

    2015-10-01

    Silicon has been considered as one of the most promising anode materials for the next generation lithium-ion battery due to its high theoretical capacity, but large volume changes during the electrochemical cycling limit its commercial application. In this study, we report the synthesis of silicon carbide @ silicon core-shell nanowires on carbon paper and their application in lithium-ion batteries. The hybrid nano-structures are fabricated via a two-step chemical vapor deposition method and directly used as the working electrode without any additional binder, exhibiting high specific capacity, high coulombic efficiency and good cycling stability. After 50 cycles, the discharge capacities still remain 2837 and 1809 mAh g-1 at the rates of 0.1C and 0.5C, respectively. Furthermore, we also study the influence of the growth time of SiC NWs and the thickness of Si film on the lithium-ion batteries' performance, and propose the possible method to further improve the battery performance.

  9. Hollow carbon nanospheres/silicon/alumina core-shell film as an anode for lithium-ion batteries

    PubMed Central

    Li, Bing; Yao, Fei; Bae, Jung Jun; Chang, Jian; Zamfir, Mihai Robert; Le, Duc Toan; Pham, Duy Tho; Yue, Hongyan; Lee, Young Hee

    2015-01-01

    Hollow carbon nanospheres/silicon/alumina (CNS/Si/Al2O3) core-shell films obtained by the deposition of Si and Al2O3 on hollow CNS interconnected films are used as the anode materials for lithium-ion batteries. The hollow CNS film acts as a three dimensional conductive substrate and provides void space for silicon volume expansion during electrochemical cycling. The Al2O3 thin layer is beneficial to the reduction of solid-electrolyte interphase (SEI) formation. Moreover, as-designed structure holds the robust surface-to-surface contact between Si and CNSs, which facilitates the fast electron transport. As a consequence, the electrode exhibits high specific capacity and remarkable capacity retention simultaneously: 1560 mA h g−1 after 100 cycles at a current density of 1 A g−1 with the capacity retention of 85% and an average decay rate of 0.16% per cycle. The superior battery properties are further confirmed by cyclic voltammetry (CV) and impedance measurement. PMID:25564245

  10. MoO2/multiwalled carbon nanotubes (MWCNT) hybrid for use as a Li-ion battery anode.

    PubMed

    Bhaskar, Akkisetty; Deepa, Melepurath; Narasinga Rao, Tata

    2013-04-10

    A molybdenum dioxide/multiwalled carbon nanotubes (MoO2/MWCNT) hybrid composed of spherical flowerlike nanostructures of MoO2, interconnected by MWCNTs has been prepared by a one-step hydrothermal route. The growth of MoO2 nanoparticles into spherical floral shapes with a monoclinic crystalline structure is steered by the dioctyl sulfosuccinate surfactant. The one-dimensional electron transport pathways provided by MWCNTs, which are in direct contact with MoO2 nanostructures, impart an enhanced reversible lithium storage capacity (1143 mA h g(-1) at a current density of 100 mA g(-1) after 200 cycles), high rate capability (408 mA h g(-1) at a high C-rate of 1000 mA g(-1)) and good cycling stability to the MoO2/MWCNT hybrid relative to neat MoO2. Surface potential mapping of the electrodes by Kelvin probe force microscopy, revealed a lower localized work function for the MoO2/MWCNT hybrid as compared to the neat oxide. This makes the MoO2/MWCNT hybrid more easily oxidizable than neat MoO2. Such a distinctive topology achieved for the MoO2/MWCNT hybrid, wherein the MWCNTs prevent the agglomeration of MoO2 nanostructures and thus preserve good electrical connectivities, makes it different in terms of both morphology and performance from all previously reported MoO2-based anode materials to date. PMID:23480480

  11. Carbon Nanotube-Enhanced Carbon-Phenenolic Ablator Material

    NASA Technical Reports Server (NTRS)

    Kikolaev, P.; Stackpoole, M.; Fan, W.; Cruden, B. A.; Waid, M.; Moloney, P.; Arepalli, S.; Arnold, J.; Partridge, H.; Yowell, L.

    2006-01-01

    This viewgraph presentation reviews the use of PICA (phenolic impregnated carbon ablator) as the selected material for heat shielding for future earth return vehicles. It briefly reviews the manufacturing of PICA and the advantages for the use of heat shielding, and then explains the reason for using Carbon Nanotubes to improve strength of phenolic resin that binds carbon fibers together. It reviews the work being done to create a carbon nanotube enhanced PICA. Also shown are various micrographic images of the various PICA materials.

  12. Efficient Natural Dye-Sensitized Solar Cells Based on Spin-Coated TiO2 Anode Materials

    NASA Astrophysics Data System (ADS)

    Yu, Xiao-Hong; Sun, Zhao-Zong; Lian, Jie; Li, Yi-Tan; Chen, Yan-Xue; Gao, Shang; Wang, Xiao; Wang, Ying-Shun; Zhao, Ming-Lin

    2013-11-01

    TiO2 anode materials are prepared on ITO glass by spin-coated method. Dye-sensitized solar cells are assembled with these anodes and natural dyes extracted from radix ophiopogonis by different solvents. The formation and characterization of anode materials are confirmed by field-emission scanning electron microscopy, x-ray diffraction, UV-visible absorption spectroscopy. Photovoltaic testing results show that energy conversion efficiency could reach 1.67% with fill factor of 0.51, open-circuit voltage of 457 mV, and short-circuit photocurrent density of 7.2 mA/cm2. The short-circuit photocurrent density can reach 7.6 mA/cm2 with efficiency of 1.33.

  13. Facile Synthesis of Nb2O5@Carbon Core-Shell Nanocrystals with Controlled Crystalline Structure for High-Power Anodes in Hybrid Supercapacitors.

    PubMed

    Lim, Eunho; Jo, Changshin; Kim, Haegyeom; Kim, Mok-Hwa; Mun, Yeongdong; Chun, Jinyoung; Ye, Youngjin; Hwang, Jongkook; Ha, Kyoung-Su; Roh, Kwang Chul; Kang, Kisuk; Yoon, Songhun; Lee, Jinwoo

    2015-07-28

    Hybrid supercapacitors (battery-supercapacitor hybrid devices, HSCs) deliver high energy within seconds (excellent rate capability) with stable cyclability. One of the key limitations in developing high-performance HSCs is imbalance in power capability between the sluggish Faradaic lithium-intercalation anode and rapid non-Faradaic capacitive cathode. To solve this problem, we synthesize Nb2O5@carbon core-shell nanocyrstals (Nb2O5@C NCs) as high-power anode materials with controlled crystalline phases (orthorhombic (T) and pseudohexagonal (TT)) via a facile one-pot synthesis method based on a water-in-oil microemulsion system. The synthesis of ideal T-Nb2O5 for fast Li(+) diffusion is simply achieved by controlling the microemulsion parameter (e.g., pH control). The T-Nb2O5@C NCs shows a reversible specific capacity of ∼180 mA h g(-1) at 0.05 A g(-1) (1.1-3.0 V vs Li/Li(+)) with rapid rate capability compared to that of TT-Nb2O5@C and carbon shell-free Nb2O5 NCs, mainly due to synergistic effects of (i) the structural merit of T-Nb2O5 and (ii) the conductive carbon shell for high electron mobility. The highest energy (∼63 W h kg(-1)) and power (16 528 W kg(-1) achieved at ∼5 W h kg(-1)) densities within the voltage range of 1.0-3.5 V of the HSC using T-Nb2O5@C anode and MSP-20 cathode are remarkable. PMID:26095456

  14. Nitrogen-rich graphene from small molecules as high performance anode material

    NASA Astrophysics Data System (ADS)

    Gao, Weiwei; Huang, Hao; Shi, Hongyan; Feng, Xun; Song, Wenbo

    2014-10-01

    Nitrogen-rich graphene sheets were successfully achieved via facile thermal condensation of glucose and dicyandiamide at different temperatures during which dicyandiamide acts both as nitrogen source and sacrifice template. Devoid of surfactants or poisonous organic solvents, this small-molecule synthetic approach is a simple and cost-effective way to obtain nitrogen-rich graphene sheets (NRGS) with high specific surface area and large pore volume. Shown to be a promising anode material, the NRGS displayed high reversible capacity, excellent rate capability, and superior cycle performance. The superior lithium-storage performance is ascribed to the unique features of NRGS, including a large quantity of defects due to the high nitrogen doping level, favorable lithium ion transportation channels by virtue of the large surface area, and ultrahigh pore volume, as well as the crumpled two-dimensional structure.

  15. Mono-layer BC2 a high capacity anode material for Li-ion batteries

    NASA Astrophysics Data System (ADS)

    Hardikar, Rahul; Samanta, Atanu; Han, Sang Soo; Lee, Kwang-Ryeol; Singh, Abhishek

    2015-04-01

    Mono-layer of graphene with high surface area compared to the bulk graphite phase, shows less Li uptake. The Li activity or kinetics can be modified via defects and/or substitutional doping. Boron and Nitrogen are the best known dopants for carbonaceous anode materials. In particular, boron doped graphene shows higher capacity and better Li adsorption compared to Nitrogen doped graphene. Here, using first principles density functional theory calculations, we study the spectrum of boron carbide (BCx) mono-layer phases in order to estimate the maximum gravimetric capacity that can be achieved by substitutional doping in graphene. Our results show that uniformly boron doped BC2 phase shows a high capacity of? 1400 mAh/g, much higher than previously reported capacity of BC3. Supported by Korea Institute of Science and Technology.

  16. Tungsten Trioxide (WO3) Nanoparticles as a New Anode Material for Sodium-Ion Batteries.

    PubMed

    Santhosha, A L; Das, Shyamal K; Bhattacharyya, Aninda J

    2016-04-01

    Tungsten trioxide (WO3) is investigated for the first time as an anode material for sodium-ion batteries. Pristine WO3 displays a discharge potential plateau at 1 V and exhibits a 1st discharge cycle sodium storage capacity of 640 mAh g-1. Electronic wiring of WO3 with graphene oxide (GO, 1% by weight) led to a significant increase in the storage capacity and cyclability of WO3. As a result, the discharge capacity of 1% GO-WO3 is enhanced to 927 mAh g-1 in the 1st discharge cycle. The electrochemical intercalation of Na in to WO3 and (1%) GO-WO3 as obtained from galvanostatic charge/discharge cycling is also supported by cyclic voltammetry. PMID:27451776

  17. Low cost fuel cell diffusion layer configured for optimized anode water management

    DOEpatents

    Owejan, Jon P; Nicotera, Paul D; Mench, Matthew M; Evans, Robert E

    2013-08-27

    A fuel cell comprises a cathode gas diffusion layer, a cathode catalyst layer, an anode gas diffusion layer, an anode catalyst layer and an electrolyte. The diffusion resistance of the anode gas diffusion layer when operated with anode fuel is higher than the diffusion resistance of the cathode gas diffusion layer. The anode gas diffusion layer may comprise filler particles having in-plane platelet geometries and be made of lower cost materials and manufacturing processes than currently available commercial carbon fiber substrates. The diffusion resistance difference between the anode gas diffusion layer and the cathode gas diffusion layer may allow for passive water balance control.

  18. Carbon Materials for Chemical Capacitive Energy Storage

    SciTech Connect

    Zhai, Yunpu; Dou, Yuqian; Zhao, Dongyuan; Fulvio, Pasquale F.; Mayes, Richard T.; Dai, Sheng

    2011-09-26

    Carbon materials have attracted intense interests as electrode materials for electrochemical capacitors, because of their high surface area, electrical conductivity, chemical stability and low cost. Activated carbons produced by different activation processes from various precursors are the most widely used electrodes. Recently, with the rapid growth of nanotechnology, nanostructured electrode materials, such as carbon nanotubes and template-synthesized porous carbons have been developed. Their unique electrical properties and well controlled pore sizes and structures facilitate fast ion and electron transportation. In order to further improve the power and energy densities of the capacitors, carbon-based composites combining electrical double layer capacitors (EDLC)-capacitance and pseudo-capacitance have been explored. They show not only enhanced capacitance, but as well good cyclability. In this review, recent progresses on carbon-based electrode materials are summarized, including activated carbons, carbon nanotubes, and template-synthesized porous carbons, in particular mesoporous carbons. Their advantages and disadvantages as electrochemical capacitors are discussed. At the end of this review, the future trends of electrochemical capacitors with high energy and power are proposed.

  19. Modified carbon black materials for lithium-ion batteries

    DOEpatents

    Kostecki, Robert; Richardson, Thomas; Boesenberg, Ulrike; Pollak, Elad; Lux, Simon

    2016-06-14

    A lithium (Li) ion battery comprising a cathode, a separator, an organic electrolyte, an anode, and a carbon black conductive additive, wherein the carbon black has been heated treated in a CO.sub.2 gas environment at a temperature range of between 875-925 degrees Celsius for a time range of between 50 to 70 minutes to oxidize the carbon black and reduce an electrochemical reactivity of the carbon black towards the organic electrolyte.

  20. Evaluation of Metal Phosphide Nanocrystals as Anode Materials for Na-ion Batteries.

    PubMed

    Walter, Marc; Bodnarchuk, Maryna I; Kravchyk, Kostiantyn V; Kovalenko, Maksym V

    2015-01-01

    Sodium-ion batteries (SIBs) are potential low-cost alternatives to lithium-ion batteries (LIBs) because of the much greater natural abundance of sodium salts. However, developing high-performance electrode materials for SIBs is a challenging task, especially due to the ∼50% larger ionic radius of the Na(+) ion compared to Li(+), leading to vastly different electrochemical behavior. Metal phosphides such as FeP, CoP, NiP(2), and CuP(2) remain unexplored as electrode materials for SIBs, despite their high theoretical charge storage capacities of 900-1300 mAh g(-1). Here we report on the synthesis of metal phosphide nanocrystals (NCs) and discuss their electrochemical properties as anode materials for SIBs, as well as for LIBs. We also compare the electrochemical characteristics of phosphides with their corresponding sulfides, using the environmentally benign iron compounds, FeP and FeS(2), as a case study. We show that despite the appealing initial charge storage capacities of up to 1200 mAh g(-1), enabled by effective nanosizing of the active electrode materials, further work toward optimization of the electrode/electrolyte pair is needed to improve the electrochemical performance upon cycling. PMID:26842319

  1. Valine adsorption and electrooxidation at carbon materials

    SciTech Connect

    Aleksandrova, L.R.; Andreev, V.N.; Bogdanovskaya, V.A.; Safronov, A.Yu.

    1987-08-01

    The authors study the electrochemical behavior of valine (which is contained on most proteins) at electrodes made of carbon materials. The electrochemical behavior of valine at carbon materials was studied potentiodynamically. Adsorption measurements involving radiotracers were performed. The valine with C/sub 1//sup 14/ label was 1% of the total amino acid concentration. Potentiodynamic curves measured at an electrode of BM-4 carbon in base electrolyte solution are presented. The results of measurements made in solutions of different pH and at different electrode materials are given. It is found that the mesoporous BM-4 carbon has the highest adsorption capacity for amino acid, while electrooxidation only occurs in neutral solutions, but at all types of carbon materials.

  2. One-step synthesis of Si@C nanoparticles by laser pyrolysis: high-capacity anode material for lithium-ion batteries.

    PubMed

    Sourice, Julien; Quinsac, Axelle; Leconte, Yann; Sublemontier, Olivier; Porcher, Willy; Haon, Cedric; Bordes, Arnaud; De Vito, Eric; Boulineau, Adrien; Jouanneau Si Larbi, Séverine; Herlin-Boime, Nathalie; Reynaud, Cécile

    2015-04-01

    Carbon-covered silicon nanoparticles (Si@C) were synthesized for the first time by a one-step continuous process in a novel two stages laser pyrolysis reactor. Crystallized silicon cores formed in a first stage were covered in the second stage by a continuous shell mainly consisting in low organized sp(2) carbon. At the Si/C interface silicon carbide is absent. Moreover, the presence of silicon oxide is reduced compared to materials synthesized in several steps, allowing the use of such material as promising anode material in lithium-ion batteries (LIB). Auger Electron Spectroscopy (AES) analysis of the samples at both SiKLL and SiLVV edges proved the uniformity of the carbon coating. Cyclic voltammetry was used to compare the stability of Si and Si@C active materials. In half-cell configuration, Si@C exhibits a high and stable capacity of 2400 mAh g(-1) at C/10 and up to 500 mAh g(-1) over 500 cycles at 2C. The retention of the capacity is attributed to the protective effect of the carbon shell, which avoids direct contact between the silicon surface and the electrolyte. PMID:25761636

  3. Effects of Carbon Structure and Surface Oxygen on the Carbon's Performance as the Anode in Lithium-Ion Battery Determined

    NASA Technical Reports Server (NTRS)

    Hung, Ching-Cheh

    2000-01-01

    Four carbon materials (C1, C2, C3, and C4) were tested electrochemically at the NASA Glenn Research Center at Lewis Field to determine their performance in lithium-ion batteries. They were formed as shown in the figure. This process caused very little carbon loss. Products C1 and C3 contained very little oxygen because of the final overnight heating at 540 C. Products C2 and C4, on the other hand, contained small amounts of basic oxide. The electrochemical test involved cycles of lithium intercalation and deintercalation using C/saturated LiI-50/50 (vol %) ethylene carbonate (EC) and dimethyl carbonate (DMC)/Li half cell. The cycling test, which is summarized in the table, resulted in three major conclusions. The capacity of the carbon with a basic oxide surface converges to a constant 1. value quickly (within 4 cycles), possibly because the oxide prevents solvent from entering the carbon structure and, therefore, prolongs the carbon s cycle life. Under certain conditions, the disordered carbon can store more lithium than its 2. precursor. These samples and their precursor can intercalate at 200 mA/g and deintercalate at 3. a rate of 2000 mA/g without significant capacity loss.

  4. Optical properties of ordered carbon nanotube arrays grown in porous anodic alumina templates.

    PubMed

    Zuidema, John; Ruan, Xiulin; Fisher, Timothy S

    2013-09-23

    We have synthesized ordered carbon nanotube (CNT) arrays in porous anodic alumina (PAA) matrix, and have characterized their total optical reflectance and bi-directional reflectance distribution function after each processing step of the microwave plasma chemical vapor deposition process (MPCVD). For a PAA sample without CNT growth, the reflectance shows an oscillating pattern with wavelength that agrees reasonably with a multilayer model. During the MPCVD process, heating the sample significantly reduces the reflectance by 30-40%, the plasma treatment reduces the reflectance by another 5-10%, and the CNT growth further reduces the reflectance by 2-3%. After an atomic layer deposition (ALD) process, the reflectance increases to the embedded CNT arrays. After etching and exposure of CNT tips, the reflectance almost returns to the original pattern with slightly higher reflectance. Bi-directional reflectance distribution function (BRDF) measurements show that the CNT-PAA surface is quite specular as indicated by a large lobe at the specular angle, while the secondary lobe can be attributed to surface roughness. PMID:24104097

  5. Recent Development on Anodes for Na-Ion Batteries

    SciTech Connect

    Bommier, C; Ji, XL

    2015-01-23

    New discoveries in anode materials for sodium ion batteries (NIBs) are highly necessary to achieve the goals of widespread applications, such as electric vehicles (EVs) and grid-level energy storage. Carbon-based materials are critical for this task as they are inexpensive, abundant, and versatile. They contain a plethora of structures and morphologies, ranging from highly ordered graphite or nanotubes to highly disordered amorphous carbon, thus making them very attractive for electrochemical energy storage. This review attempts to cover past and recent progress in the development of carbon-based anode materials for NIBs. To give a larger context, the article will briefly cover other anode materials for NIBs as well. The aim of this paper is to provide a timely update for researchers currently involved in the respective fields or to serve as a starting point for individuals who would like to gain a greater knowledge of new NIB anode materials.

  6. A facile synthesis of a carbon-encapsulated Fe3O4 nanocomposite and its performance as anode in lithium-ion batteries.

    PubMed

    Prakash, Raju; Fanselau, Katharina; Ren, Shuhua; Kumar Mandal, Tapan; Kübel, Christian; Hahn, Horst; Fichtner, Maximilian

    2013-01-01

    A carbon-encapsulated Fe3O4 nanocomposite was prepared by a simple one-step pyrolysis of iron pentacarbonyl without using any templates, solvents or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer-Emmett-Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The nanocomposite exhibits well constructed core-shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances. PMID:24205466

  7. A facile synthesis of a carbon-encapsulated Fe3O4 nanocomposite and its performance as anode in lithium-ion batteries

    PubMed Central

    Prakash, Raju; Fanselau, Katharina; Ren, Shuhua; Kumar Mandal, Tapan; Kübel, Christian; Hahn, Horst

    2013-01-01

    Summary A carbon-encapsulated Fe3O4 nanocomposite was prepared by a simple one-step pyrolysis of iron pentacarbonyl without using any templates, solvents or surfactants. The structure and morphology of the nanocomposite was investigated by X-ray diffraction, scanning electron microscopy, transmission electron microscopy, Brunauer–Emmett–Teller analysis and Raman spectroscopy. Fe3O4 nanoparticles are dispersed intimately in a carbon framework. The nanocomposite exhibits well constructed core–shell and nanotube structures, with Fe3O4 cores and graphitic shells/tubes. The as-synthesized material could be used directly as anode in a lithium-ion cell and demonstrated a stable capacity, and good cyclic and rate performances. PMID:24205466

  8. Fe-doped SnO2 nanoparticles as new high capacity anode material for secondary lithium-ion batteries

    NASA Astrophysics Data System (ADS)

    Mueller, Franziska; Bresser, Dominic; Chakravadhanula, Venkata Sai Kiran; Passerini, Stefano

    2015-12-01

    Herein, Fe-doped tin oxide is presented for the first time as new high-capacity lithium-ion anode material. Pure SnO2, Fe-doped SnO2 (Sn0.9Fe0.1O2, SFO), and carbon-coated SFO (SFO-C) were synthesized and morphologically and electrochemically characterized by X-ray diffraction, transmission electron microscopy, thermogravimetric analysis, Brunauer-Emmet-Teller method, and galvanostatic (dis-)charge measurements. Doping SnO2 with Fe results in a substantially enhanced reversible specific capacity and coulombic efficiency. After ten cycles the reversible capacity of SFO-C was about 1519 mAh g-1, i.e., almost twice the specific capacity obtained for pure SnO2 (764 mAh g-1). Moreover, limiting the reversible capacity to 600 mAh g-1 shows the great potential of SFO-C for application in lithium-ion batteries.

  9. Electrospun Ni-added SnO2-carbon nanofiber composite anode for high-performance lithium-ion batteries.

    PubMed

    Kim, Dongha; Lee, Daehee; Kim, Joosun; Moon, Jooho

    2012-10-24

    The SnO(2) anode is a promising anode for next-generation Li ion batteries because of its high theoretical capacity. However, it exhibits inherent capacity fading because of the large volume change and pulverization that occur during the charge/discharge cycles. The buffer matrix, such as electrospun carbon nanofibers (CNFs), can alleviate this problem to some extent, but SnO(2) particles are thermodynamically incompatible with the carbon matrix such that large Sn agglomerates form after carbonization upon melting of the Sn. Herein, we introduce well-dispersed nanosized SnO(2) attached to CNFs for high-performance anodes developed by Ni presence. The addition of Ni increases the stability of the SnO(2) such that the morphologies of the dispersed SnO(2) phase are modified as a function of the Ni composition. The optimal adding composition is determined to be Ni:Sn = 10:90 wt % in terms of the crystallite size and the distribution uniformity. A high capacity retention of 447.6 mA h g(-1) after 100 cycles can be obtained for 10 wt % Ni-added SnO(2)-CNFs, whereas Ni-free Sn/SnO(2)-CNFs have a capacity retention of 304.6 mA h g(-1). PMID:22999049

  10. Process and apparatus for recovery of fissionable materials from spent reactor fuel by anodic dissolution

    DOEpatents

    Tomczuk, Zygmunt; Miller, William E.; Wolson, Raymond D.; Gay, Eddie C.

    1991-01-01

    An electrochemical process and apparatus for the recovery of uranium and plutonium from spent metal clad fuel pins is disclosed. The process uses secondary reactions between U.sup.+4 cations and elemental uranium at the anode to increase reaction rates and improve anodic efficiency compared to prior art processes. In another embodiment of the process, secondary reactions between Cd.sup.+2 cations and elemental uranium to form uranium cations and elemental cadmium also assists in oxidizing the uranium at the anode.

  11. Synthesis and electrochemical characterization of Silicon clathrates as anode materials for Lithium ion batteries

    NASA Astrophysics Data System (ADS)

    Raghavan, Rahul

    Novel materials for Li-ion batteries is one of the principle thrust areas for current research in energy storage, more so than most, considering its widespread use in portable electronic gadgets and plug-in electric and hybrid cars. One of the major limiting factors in a Li-ion battery's energy density is the low specific capacities of the active materials in the electrodes. In the search for high-performance anode materials for Li-ion batteries, many alternatives to carbonaceous materials have been studied. Both cubic and amorphous silicon can reversibly alloy with lithium and have a theoretical capacity of 3500 mAh/g, making silicon a potential high density anode material. However, a large volume expansion of 300% occurs due to changes in the structure during lithium insertion, often leading to pulverization of the silicon. To this end, a class of silicon based cage compounds called clathrates are studied for electrochemical reactivity with lithium. Silicon-clathrates consist of silicon covalently bonded in cage structures comprised of face sharing Si20, Si24 and/or Si28 clusters with guest ions occupying the interstitial positions in the polyhedra. Prior to this, silicon clathrates have been studied primarily for their superconducting and thermoelectric properties. In this work, the synthesis and electrochemical characterization of two categories of silicon clathrates - Type-I silicon clathrate with aluminum framework substitution and barium guest ions (Ba8AlxSi46-x) and Type-II silicon clathrate with sodium guest ions (Nax Si136), are explored. The Type-I clathrate, Ba8AlxSi46-x consists of an open framework of aluminium and silicon, with barium (guest) atoms occupying the interstitial positions. X-ray diffraction studies have shown that a crystalline phase of clathrate is obtained from synthesis, which is powdered to a fine particle size to be used as the anode material in a Li-ion battery. Electrochemical measurements of these type of clathrates have shown

  12. Raman Scattering in a New Carbon Material

    NASA Technical Reports Server (NTRS)

    Voronov, O. A.; Street, K. W., Jr.

    2010-01-01

    Samples of a new carbon material, Diamonite-B, were fabricated under high pressure from a commercial carbon black--identified as mixed fullerenes. The new material is neither graphite-like nor diamond-like, but exhibits electrical properties close to graphite and mechanical properties close to diamond. The use of Raman spectroscopy to investigate the vibrational dynamics of this new carbon material and to provide structural characterization of its short-, medium- and long-range order is reported. We also provide the results of investigations of these samples by high-resolution electron microscopy and X-ray diffraction. Hardness, electrical conductivity, thermal conductivity and other properties of this new material are compared with synthetic graphite-like and diamond-like materials, two other phases of synthetic bulk carbon.

  13. Thin flexible intercalation anodes

    SciTech Connect

    Levy, S.C.; Cieslak, W.R.; Klassen, S.E.; Lagasse, R.R.

    1994-10-01

    Poly(acrylonitrile) fibers have been pyrolyzed under various conditions to form flexible carbon yarns capable of intercalating lithium ions. These fibers have also been formed into both woven and non woven cloths. Potentiostatic, potentiodynamic and galvanostatic tests have been conducted with these materials in several electrolytes. In some tests, a potential hold was used after each constant current charge and discharge. These tests have shown some of these flexible materials to reversibly intercalate lithium ions to levels that are suitable for use as a practical battery anode.

  14. The role of oxygen in low-potential Li insertion in metal oxide anode materials

    SciTech Connect

    Leroux, F.; Nazar, L.F.

    2000-07-01

    Transition metal oxides are high-capacity lithium storage materials of interest as possible anode materials in the next generation of Li ion batteries. By using X-ray absorption spectroscopy the authors have obtained an understanding of the process of Li uptake and removal within Na{sub 0.25}MoO{sub 3}. Results show the Li{sub 2}O matrix on reduction is not inert; Mo-O bonds are reversibly consumed on discharge and are regenerated on charge, with the Li{sub 2}O matrix acting as the oxygen reservoir. The migration of oxygen atoms from the matrix to the active centers occurs at a voltage below that expected for the Li{sub 2}O free energy of formation. Polarization on charge is not due only to oxygen migration but also to metal rearrangement within the electrode material. The reversibility of the Mo-O bond formation on repeated cycles is a function of the depth of discharge, with 200 mV being the lower limit.

  15. Hierarchical porous nickel oxide-carbon nanotubes as advanced pseudocapacitor materials for supercapacitors

    NASA Astrophysics Data System (ADS)

    Su, Aldwin D.; Zhang, Xiang; Rinaldi, Ali; Nguyen, Son T.; Liu, Huihui; Lei, Zhibin; Lu, Li; Duong, Hai M.

    2013-03-01

    Hierarchical porous carbon anode and metal oxide cathode are promising for supercapacitor with both high energy density and high power density. This Letter uses NiO and commercial carbon nanotubes (CNTs) as electrode materials for electrochemical capacitors with high energy storage capacities. Experimental results show that the specific capacitance of the electrode materials for 10%, 30% and 50% CNTs are 279, 242 and 112 F/g, respectively in an aqueous 1 M KOH electrolyte at a charge rate of 0.56 A/g. The maximum specific capacitance is 328 F/g at a charge rate of 0.33 A/g.

  16. Hierarchical Sandwich-Like Structure of Ultrafine N-Rich Porous Carbon Nanospheres Grown on Graphene Sheets as Superior Lithium-Ion Battery Anodes.

    PubMed

    Xie, Zhiqiang; He, Ziyang; Feng, Xuhui; Xu, Wangwang; Cui, Xiaodan; Zhang, Jiuhong; Yan, Cheng; Carreon, Moises A; Liu, Zheng; Wang, Ying

    2016-04-27

    A sandwich-like, graphene-based porous nitrogen-doped carbon (PNCs@Gr) has been prepared through facile pyrolysis of zeolitic imidazolate framework nanoparticles in situ grown on graphene oxide (GO) (ZIF-8@GO). Such sandwich-like nanostructure can be used as anode material in lithium ion batteries, exhibiting remarkable capacities, outstanding rate capability, and cycling performances that are some of the best results among carbonaceous electrode materials and exceed most metal oxide-based anode materials derived from metal orgainc frameworks (MOFs). Apart from a high initial capacity of 1378 mAh g(-1) at 100 mA g(-1), this PNCs@Gr electrode can be cycled at high specific currents of 500 and 1000 mA g(-1) with very stable reversible capacities of 1070 and 948 mAh g(-1) to 100 and 200 cycles, respectively. At a higher specific current of 5000 mA g(-1), the electrode still delivers a reversible capacity of over 530 mAh g(-1) after 400 cycles, showing a capacity retention of as high as 84.4%. Such an impressive electrochemical performance is ascribed to the ideal combination of hierarchically porous structure, a highly conductive graphene platform, and high-level nitrogen doping in the sandwich-like PNCs@Gr electrode obtained via in situ synthesis. PMID:27071473

  17. An sp2 and sp3 hybrid nanocrystalline carbon film electrode for anodic stripping voltammetry and its application for electrochemical immunoassay.

    PubMed

    Kurita, Ryoji; Nakamoto, Kohei; Sato, Yuko; Kamata, Tomoyuki; Ueda, Akio; Kato, Dai; Hirono, Shigeru; Niwa, Osamu

    2012-01-01

    A hybridized nanocrystalline carbon film electrode consisting of sp(2) and sp(3) bonds was investigated to reveal the reduction properties of Cd(2+) and for application as a highly sensitive and reliable electrochemical immunoassay. Conductive nanocrystalline carbon film consisting of about 60% sp(2) and 40% sp(3) bonds was fabricated using electron cyclotron resonance (ECR) sputtering equipment, and then the Cd(2+) concentrations were measured with an ECR sputtered carbon (ECR nano-carbon) electrode by employing an anodic stripping voltammetry (ASV) technique. The preconcentrated Cd was analyzed with Kelvin probe force microscopy and energy dispersive X-ray spectroscopy while observing the morphology change with an atomic force microscope and a scanning electron microscope. The preconcentrated Cd on the ECR nano-carbon electrode was revealed to be a thin sheet structure, which was significantly different from the Cd on a conventional carbon material that grows with a coralloid structure. The background current during an ASV measurement maintains a low level equivalent to that found with boron-doped diamond because the surface of the ECR nano-carbon is robust and angstrom-level flat. The carbon-electrode performance for ASV was improved by controlling its structure at a nanometer scale without any metal doping or coating. Finally, the ECR nano-carbon was used for biomolecular determination by electrochemical immunoassay with a CdSe nanoparticle label. Electrochemical immunoassay results were successfully obtained with the ECR nano-carbon, and they correlated well with fluorescence results obtained for CdSe nanoparticles. PMID:22232218

  18. On-demand supply of slurry fuels to a porous anode of a direct carbon fuel cell: Attempts to increase fuel-anode contact and realize long-term operation

    NASA Astrophysics Data System (ADS)

    Li, Chengguo; Yi, Hakgyu; Lee, Donggeun

    2016-03-01

    In this paper, we propose a novel idea that might allow resolution of the two biggest challenges that hinder practical use of direct carbon fuel cells (DCFC). This work involved 1) the use of three types of porous Ni anode with different pore sizes, 2) size matching between the anode pores and solid fuel particles in a molten-carbonate (MC) slurry, and 3) provision of a continuous supply of fuel-MC slurry through the porous Ni anode. As a result, larger numbers of smaller pores in the anode were preferred for extending the triple phase boundary (TPB), as long as the fuel particles were sufficiently small to have full access to the inner pore spaces of the anode. For example, the maximal power density achieved in the case of optimal size matching, reached 645 mW cm-2, which is 14-times greater than that for the case of poorest size-matching and 64-times larger than that for a non-porous anode, and lasted for more than 20 h. After 20 h of steady operation at a fixed current density (700 mA cm-2), the electric potential slightly decreased due to partial consumption of the fuel. The cell performance readily recovered after restarting the supply of MC-fuel slurry.

  19. Unique 1D Co3O4 crystallized nanofibers with (220) oriented facets as high-performance lithium ion battery anode material

    PubMed Central

    Tan, Yanli; Gao, Qiuming; Li, Zeyu; Tian, Weiqian; Qian, Weiwei; Yang, Chunxiao; Zhang, Hang

    2016-01-01

    A novel one-step hydrothermal and calcination strategy was developed to synthesize the unique 1D oriented Co3O4 crystal nanofibers with (220) facets on the carbon matrix derived from the natural, abundant and low cost wool fibers acting as both carbon precursor and template reagent. The resultant W2@Co3O4 nanocomposite exhibited very high specific capacity and favorable high-rate capability when used as anode material of lithium ion battery. The high reversible Li+ ion storage capacity of 986 mAh g−1 was obtained at 100 mA g−1 after 150 cycles, higher than the theoretical capacity of Co3O4 (890 mAh g−1). Even at the higher current density of 1 A g−1, the electrode could still deliver a remarkable discharge capacity of 720 mAh g−1 over 150 cycles. PMID:27217201

  20. Unique 1D Co3O4 crystallized nanofibers with (220) oriented facets as high-performance lithium ion battery anode material.

    PubMed

    Tan, Yanli; Gao, Qiuming; Li, Zeyu; Tian, Weiqian; Qian, Weiwei; Yang, Chunxiao; Zhang, Hang

    2016-01-01

    A novel one-step hydrothermal and calcination strategy was developed to synthesize the unique 1D oriented Co3O4 crystal nanofibers with (220) facets on the carbon matrix derived from the natural, abundant and low cost wool fibers acting as both carbon precursor and template reagent. The resultant W2@Co3O4 nanocomposite exhibited very high specific capacity and favorable high-rate capability when used as anode material of lithium ion battery. The high reversible Li(+) ion storage capacity of 986 mAh g(-1) was obtained at 100 mA g(-1) after 150 cycles, higher than the theoretical capacity of Co3O4 (890 mAh g(-1)). Even at the higher current density of 1 A g(-1), the electrode could still deliver a remarkable discharge capacity of 720 mAh g(-1) over 150 cycles. PMID:27217201