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1.
A 3D structured composite of carbon nanofibers@MnO2 on copper foil is reported here as a binder free anode of lithium ion batteries, with high capacity, fast charge/discharge rate and good stability. Carbon nanofiber yarns were synthesized directly over copper foil through a floating catalyst method. The growth of carbon nanofiber yarns was significantly enhanced by mechanical polishing of the copper foils, which can be attributed to the increased surface roughness and surface area of the copper foils. MnO2 was then grown over carbon nanofibers through spontaneous reduction of potassium permanganate by the carbon nanofibers. The obtained composites of carbon nanofibers@MnO2 over copper foil were tested as an anode in lithium ion batteries and they show superior electrochemical performance. The initial reversible capacity of carbon nanofibers@MnO2 reaches up to around 998 mAh g-1 at a rate of 60 mmA g-1 based on the mass of carbon nanofibers and MnO2 . The carbon nanofibers@MnO2 electrodes could deliver a capacity of 630 mAh g-1 at the beginning and maintain a capacity of 440 mmAh g-1 after 105 cycles at a rate of 600 mA g-1 . The high initial capacity can be attributed to the presence of porous carbon nanofiber yarns which have good electrical conductivity and the MnO2 thin film which makes the entire materials electrochemically active. The high cyclic stability of carbon nanofibers@MnO2 can be ascribed to the MnO2 thin film which can accommodate the volume expansion and shrinking during charge and discharge and the good contact of carbon nanofibers with MnO2 and copper foil. 相似文献
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Renzong Hu Wei Sun Meiqin Zeng Min Zhu 《天然气化学杂志》2014,(3):338-345
We demonstrate a facile route for the massive production of SnCb/carbon nanocomposite used as high-capacity anode materials of nextgeneration lithium-ion batteries.The nanocomposite had a unique structure of ultrafine SnO2 nanocrystals(5 nm,80 wt%) homogeneously dispersed in amorphous carbon matrix.This structure design can well accommodate the volume change of Li+ insertion/desertion in SnO2,and prevent the aggregation of the nanosized active materials during cycling,leading to superior cycle performance with stable reversible capacity of 400 mAh/g at a high current rate of 3.3 A/g. 相似文献
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Microporous carbon aerogel prepared through ambient pressure drying route as anode material for lithium ion cells 下载免费PDF全文
Ancy Smitha Alex Ananda Lekshmi M.S. Sekkar V. Bibin John Gouri C. Ilangovan S.A. 《先进技术聚合物》2017,28(12):1945-1950
Carbon aerogel synthesized through a cost‐effective and easy method was evaluated and found to be a promising anode material for lithium ion cells. Carbon aerogel was prepared by carbonizing resorcinol–formaldehyde (RF) aerogel under inert atmosphere. Resorcinol–formaldehyde aerogel in turn was prepared through sol gel polymerization of resorcinol with formaldehyde using sodium carbonate as catalyst adopting ambient pressure drying route. The structure and the morphology of the prepared carbon aerogel are investigated using X‐ray diffraction (XRD), scanning electron microscopy (SEM) and transmission electron microscopy (TEM) and surface area determined using N2–Brunauer–Emmett–Teller (BET) method. The TEM images reveal microporous morphology of the carbon aerogel particles. The evaluation of carbon aerogel as an anode material revealed promising specific capacity synergized with outstanding cyclability. The first cycle specific capacity was 288 mAh/g with an efficiency of 63% at C/10 rate. The material retained a capacity of 96.9% of the initial capacity with about 100% efficiency after 100 cycles, showing the excellent cyclability of the material. Copyright © 2017 John Wiley & Sons, Ltd. 相似文献
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Fangyuan Zhao Xin Zhao Bo Peng Feng Gan Mengyao Yao Wenjun Tan Jie Dong Qinghua Zhang 《中国化学快报》2018,29(11):1692-1697
Heteroatoms-doped carbon nanofiber membranes with flexible features were prepared by electrospinning with heterocyclic polyimide (PI) structures containing biphenyl and pyrimidine rings. The products with optimized treatment could achieve 695 mAh/g at 0.1 A/g and retain 245 mAh/g at 1.5 A/g after 300 cycles when used as anode for Li-ion batteries. 相似文献
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High molecular weight (MW) polyvinyl alcohol (PVA) was synthesized by two-step polymerizations and employed as an anodic binder of lithium ion batteries (LIBs). Numerous hydroxyl groups in PVA formed strong hydrogen bonds with both active materials and the current collector. These strong hydrogen bonds led to an increase in the amount of binder covering the surface of active materials and significantly enhanced the adhesion strength of electrodes. The high MW PVA binder showed much better cyclic performance for silicon/carbon anodes than polyvinylidene fluoride (PVDF) and polyacrylic acid (PAA) binders. 相似文献
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锂离子电池锡基复合氧化物负极材料的研究 总被引:4,自引:1,他引:4
采用共沉淀法制备了SnSbO2.5和SnGeO3两种锡基复合氧化物粉末.XRD分析表明,这两种锡基复合氧化物的共同特点是在27°~28°处有波峰,属无定型结构.将其分别作为锂离子电池负极材料的活性物质,利用恒电流电池测试仪研究它们的电化学性能.实验表明,这两种锡基复合氧化物都有较高的电化学容量,SnSbO2.5的可逆容量为1200mA·h/g,SnGeO3的可逆容量为750mA·h/g.这两种锡基复合氧化物的电化学容量远高于碳材料(石墨的理论容量为372mA·h/g),因此,这两种锡基复合氧化物可以作为锂离子电池负极材料的候选材料. 相似文献
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Lithium ion batteries which are an energy storage system have increasing attention owing to suitability and advantages for many applications. Although it has ideal specifications, the capacity properties still have to be developed. In this study, the electrical conductivity of the anode was increased by using a conductive polymer binder and the active material content of the anode was also enhanced without adding carbon additives. Silicon based anodes were manufactured by using poly(3,4-ethylenedioxythiophene)/polystyrene sulfonate (PEDOT:PSS) and poly(3,4-ethylenedioxythiophene)/polythiophenesulfonyl chloride (PEDOT:PTS) conductive polymer binders. Si/PEDOT:PTS anode showed about 2000 mAh/g specific capacities after 60 cycles with decreasing impedance. 相似文献
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To improve the initial coulombic efficiency and bulk density of ordered mesoporous carbons, active Fe2O3 nanoparticles were introduced into tubular mesopore channels of CMK-5 carbon, which possesses high specific surface area (>1700 m2·g?1) and large pore volume (>1.8 cm3·g?1). Fine Fe2O3 nanoparticles with sizes in the range of 5–7 nm were highly and homogenously encapsulated into CMK-5 matrix through ammonia-treatment and subsequent pyrolysis method. The Fe2O3 loading was carefully tailored and designed to warrant a high Fe2O3 content and adequate buffer space for improving the electrochemical performance. In particular, such Fe2O3 and mesoporous carbon composite with 47 wt% loading exhibits a considerably stable cycle performance (683 mAh·g?1 after 100 cycles, 99% capacity retention against that of the second cycle) as well as good rate capability. The fabrication strategy can effectively solve the drawback of single material, and achieve a high-performance lithium electrode material. 相似文献
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The structural evolution of the Co3O4 fine powders prepared by rheological phase reaction and pyrolysis method upon different temperature has been investigated using X‐ray diffraction (XRD) topography. The electrochemical performance of Co3O4 electrode materials for Li‐ion batteries is studied in the form of Li/Co3O4 cells. The reversible capacity as high as 930 mAh/g for the Co3O4 sample heat‐treated at 600 °C is achieved and sustained over 30 times charge‐discharge cycles at room temperature. The detailed information concerning the reaction mechanism of Co3O4 active material together with lithium ion is obtained through ex‐situ XRD topography, X‐ray photoelectron spectroscopy (XPS) analysis and cyclic voltammetry (CV) technique. And it is revealed that a “two‐step” reaction is involved in the charge and discharge of the Li/Co3O4 cells, in which Co3O4 active material is reversibly reduced into xCoO(3 ‐ x)CoO and then into metallic Co. 相似文献
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《Journal of Energy Chemistry》2014,23(1):105-110
A novel carbon matrix/silicon nanowires (SiNWs) heterogeneous block was successfully produced by dispersing SiNWs into templated carbon matrix via a modified evaporation induced self-assembly method. The heterogeneous block was determined by X-ray diffraction, Raman spectra and scanning electron microscopy. As an anode material for lithium batteries, the block was investigated by cyclic voltammograms (CV), charge/discharge tests, galvanostatic cycling performance and A. C. impedance spectroscopy. We show that the SiNWs disperse into the framework, and are nicely wrapped by the carbon matrix. The heterogeneous block exhibits superior electrochemical reversibility with a high specific capacity of 529.3 mAh/g in comparison with bare SiNWs anode with merely about 52.6 mAh/g capacity retention. The block presents excellent cycle stability and capacity retention which can be attributed to the improvement of conductivity by the existence of carbon matrix and the enhancement of ability to relieve the large volume expansion of SiNWs during the lithium insertion/extraction cycle. The results indicate that the as-prepared carbon matrix/SiNWs heterogeneous block can be an attractive and potential anode material for lithium-ion battery applications. 相似文献
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Nb2O5-carbon nanocomposite is synthesized through a facile one-step hydrothermal reaction from sucrose as the carbon source, and studied as an anode material for high-performance lithium ion battery. The structural characterizations reveal that the nanocomposite possesses a core-shell structure with a thin layer of carbon shell homogeneously coated on the Nb2O5 nanocrystals. Such a unique structure enables the composite electrode with a long cycle life by preventing the Nb2O5 from volume change and pulverization during the charge-discharge process. In addition, the carbon shell efficiently improves the rate capability. Even at a current density of 500 mA·g?1, the composite electrode still exhibits a specific capacity of ~100 mAh·g?1. These results suggest the possibility to utilize the Nb2O5-carbon core-shell composite as a high performance anode material in the practical application of lithium ion battery. 相似文献
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Synthesis strategies, nanostructures, and different electrochemical performances are prominent features of rechargeable batteries. Three types Li2MSiO4 cathode metarials for lithium ion batteries:Li2FeSiO4, Li2MnSiO4, and Li2CoSiO4 are scientifically discussed, and the comprehensive summaries and evaluations are given in this review. 相似文献
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A new SnO_2-Fe_2O_3/SWCNTs(single-walled carbon nanotubes) ternary nanocomposite was first synthesized by a facile hydrothermal approach.SnO_2 and Fe_2O_3 nanoparticles(NPs) were homogeneously located on the surface of SWCNTs,as confirmed by X-ray diffraction(XRD),transmission electron microscope(TEM) and energy dispersive X-ray spectroscopy(EDX).Due to the synergistic effect of different components,the as synthesized SnO_2-Fe_2O_3/SWCNTs composite as an anode material for lithium-ion batteries exhibited excellent electrochemical performance with a high capacity of 692 mAh·g~(-1) which could be maintained after 50 cycles at 200 mA·g~(-1).Even at a high rate of2000 mA·g~(-1),the capacity was still remained at 656 mAh·g~(-1). 相似文献
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L Wang X He J Li W Sun J Gao J Guo C Jiang 《Angewandte Chemie (International ed. in English)》2012,51(36):9034-9037
More than LiP service: The adsorption of red phosphorus into porous carbon provides a composite anode material for lithium-ion batteries. The amorphous nano phosphorus, in the carbon matrix, shows highly reversible lithium storage with high coulombic efficiencies and stable cycling capacity of 750?mAh per gram composite. 相似文献
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L. J. Ning Y. P. Wu L. Z. Wang S. B. Fang R. Holze 《Journal of Solid State Electrochemistry》2005,9(7):520-523
Three kinds of silicon-containing disordered carbons have been prepared by pyrolysis of polysiloxanes with different amounts of phenyl side groups. X-ray powder diffraction, X-ray photoelectron spectroscopy and electrochemical capacity measurements were performed to study their behaviors. Graphite crystallites, micropores, and silicon species affect their electrochemical performances. All of them present high reversible capacities, >372 mAh/g. Since the graphite crystallites are very small, they contribute very little to reversible capacity. The number of micropores produced by gas emission during the heat-treatment process decides whether they exhibit reversible capacity. Si mainly exists in the form C–Si–O and influences the irreversible capacity. There is no evident capacity fading in the first ten cycles, indicating promising properties for these disordered carbons. 相似文献
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B Koo H Kim Y Cho KT Lee NS Choi J Cho 《Angewandte Chemie (International ed. in English)》2012,51(35):8762-8767
A support bandage for electrodes: A cross-linked polymeric binder inhibits mechanical fracture of silicon negative electrodes during cycling. Nanosized silicon powder with a 3D interconnected network of poly(acrylic acid) and sodium carboxymethylcellulose as binder exhibits high reversible capacity of over 2000?mAh?g(-1) after 100 cycles at 30?°C while maintaining a high capacity and high current density. 相似文献