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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

    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.

  10. 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

  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

    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.

  16. 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

  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. 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.

  10. 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

  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. 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.

  16. 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.

  17. 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

  18. 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

  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. 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

  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. 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.

  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. 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

  5. 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.

  6. 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

  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

    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

  16. 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

  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. 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

  6. 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

  7. 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

  8. 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.

  9. 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.

  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. 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.

  6. 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.

  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. 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

  10. 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

  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. 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

  14. 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.

  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. 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.

  20. 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.

  1. 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

  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. 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})

  4. 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.

  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. 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.

  11. 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.

  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. 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.

  15. 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.

  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. 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

  20. 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

  1. 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.

  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. 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.

  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. 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.

  7. 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

  8. 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

  9. 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.

  10. 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