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1.
Journal of Solid State Electrochemistry - The morphology of Co-based zeolitic imidazolate framework is affected by the molar ratio of 2-methylimidazole and Co2+ used during the synthesis. In this...  相似文献   

2.
Carbon coated magnetite (Fe3O4) core-shell nanorods were synthesized by a hydrothermal method using Fe2O3 nanorods as the precursor. Transmission electron spectroscopy (TEM) and high resolution TEM (HRTEM) analysis indicated that a carbon layer was coated on the surfaces of the individual Fe3O4 nanorods. The electrochemical properties of Fe3O4/carbon nanorods as anodes in lithium-ion cells were evaluated by cyclic voltammetry, ac impedance spectroscopy, and galvanostatic charge/discharge techniques. The as-prepared Fe3O4/C core-shell nanorods show an initial lithium storage capacity of 1120 mAh/g and a reversible capacity of 394 mAh/g after 100 cycles, demonstrating better performance than that of the commercial graphite anode material.  相似文献   

3.
Mn-based oxide-loaded porous carbon nanofiber anodes, exhibiting large reversible capacity, excellent capacity retention, and good rate capability, are fabricated by carbonizing electrospun polymer/Mn(CH3COO)2 composite nanofibers without adding any polymer binder or electronic conductor. The excellent electrochemical performance of these organic/inorganic nanocomposites is a result of the unique combinative effects of nano-sized Mn-based oxides and carbon matrices as well as the highly-developed porous composite nanofiber structure, which make them promising anode candidates for high-performance rechargeable lithium-ion batteries.  相似文献   

4.
Nano-sized caiboxylales Na2C7H3NO4 and Na2C6H2N2O4 were prepared and investigated as anode materials for lithium-ion batteries.Both carboxylates exhibit high reversible capacities around 190 mAh/g above a cut-off voltage of 0.8 V vs.Li+/Li.potentially improving the safety of the batteries.In addition,good rate performance and long cycle life of these carboxylates make them promising candidates as anode materials for lithium-ion batteries.  相似文献   

5.
Li B  Cao H  Shao J  Li G  Qu M  Yin G 《Inorganic chemistry》2011,50(5):1628-1632
This paper reports on the synthesis of Co(3)O(4)@graphene composites (CGC) and their applications as anode materials in lithium ion batteries (LIBs). Through a chemical deposition method, Co(3)O(4) nanoparticles (NPs) with sizes in the range of 10-30 nm were homogeneously dispersed onto graphene sheets. Due to their high electrical conductivity, the graphene sheets in the CGC improved the electrical conductivity and the structure stability of CGC. CGC displayed a superior performance in LIBs with a large reversible capacity value of 941 mA hg(-1) in the initial cycle with a large current density and an excellent cyclic performance of 740 mA hg(-1) after 60 cycles, corresponding to 88.3% of the theoretical value of CGC, owing to the interactions between graphene sheets and Co(3)O(4) NPs anchored on the graphene sheets. This synthesis approach may find its application in the design and synthesis of novel electrode materials used in LIBs.  相似文献   

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Silicon(Si) is regarded as the potential anode for lithium-ion batteries(LIBs), due to the remarkable theoretical specific capacity and low voltage plateau. However, the rapid capacity decay resulting from volume variation and slow electron/ion transportation of Si limit its practical application. Here, matryoshka-type carbon-stabilized hollow silicon spheres(Si/C/Si/C) are synthesized by an aluminothermic reduction and calcination process. The Si/C/Si/C anode materials prepared at 500 ℃(Si/C/Si...  相似文献   

9.
A low-cost, fast, facile, green method, namely an ultrasound assisted approach, has been developed for the controlled synthesis of Cu(2)O-graphene hybrid nanomaterials. By the protection of graphene nanosheets, the as-obtained anode material exhibited enhanced lithium ion battery performance.  相似文献   

10.
This work introduces an effective, inexpensive, and large-scale production approach to the synthesis of Fe2O3 nanoparticles with a favorable configuration that 5 nm iron oxide domains in diameter assembled into a mesoporous network. The phase structure, morphology, and pore nature were characterized systematically. When used as anode materials for lithium-ion batteries, the mesoporous Fe2O3 nanoparticles exhibit excellent cycling performance (1009 mA h g 1 at 100 mA g 1 up to 230 cycles) and rate capability (reversible charging capacity of 420 mA h g 1 at 1000 mA g 1 during 230 cycles). This research suggests that the mesoporous Fe2O3 nanoparticles could be suitable as a high rate performance anode material for lithium-ion batteries.  相似文献   

11.
The demand for efficient and cheap electrochemical storage devices is very high today. Na-ion batteries are emerging as a promising alternative to Li-ion batteries for large-scale applications because of the much larger abundance of sodium. Among the different negative electrode materials allowing Na insertion at low potentials, hard carbons are the materials with the best electrochemical performances reported so far. Here we investigate the synthesis of hard carbons from tannins, an abundant and cheap bio-sourced carbon precursor made of polyphenolic molecules. We show that by a well-controlled synthesis method and high-temperature pyrolysis (1600°C), a hard carbon with developed ultra-microporosity is obtained. This hard carbon delivers a reversible capacity of 306 mAh g?1 at C/20 with a first-cycle coulombic efficiency of 87%. To our knowledge, these electrochemical performances are among the best ever reported in the literature for biomass-derived hard carbons.  相似文献   

12.
ZnFe(2)O(4)/C hollow spheres have been synthesized via a facile solvothermal route using low cost raw materials. The resulting composite showed a very high specific capacity of 841 mAh g(-1) after 30 cycles and good rate capability.  相似文献   

13.
Journal of Solid State Electrochemistry - The purplish-red rod-like crystal structure of novel bimetallic metal–organic-frameworks (MOF) {CoZn[(4,4′-BDA)(Phen)]2}n has been obtained by...  相似文献   

14.
The decomposition reaction of niobium(V) oxytrichloride ammoniate to the oxynitride of niobium in the 5+ oxidation state was developed in a methodological way. By combining elemental analysis, Rietveld refinements of X-ray and neutron diffraction data, SEM and TEM, the sample compound was identified as approximately 5?nm-diameter particles of NbO(1.3(1))N(0.7(1)) crystallizing with baddeleyite-type structure. The thermal stability of this compound was studied in detail by thermogravimetric/differential thermal analysis and temperature-dependent X-ray diffraction. Moreover, the electrochemical uptake and release by the galvanostatic cycling method of pure and carbon-coated NbO(1.3(1))N(0.7(1)) versus lithium was investigated as an example of an Li-free transition-metal oxynitride. The results showed that reversible capacities as high as 250 and 80?A?h kg(-1) can be reached in voltage ranges of 0.05-3 and 1-3?V, respectively. Furthermore, a plausible mechanism for the charge-discharge reaction is proposed.  相似文献   

15.
Silicon nanoparticles have been successfully inserted into graphene sheets via a novel method combining freeze-drying and thermal reduction. The as-obtained Si/graphene nanocomposite exhibits remarkably enhanced cycling performance and rate performance compared with bare Si nanoparticles for lithium-ion batteries.  相似文献   

16.
Carbon nanosprings (CNSs) with spring diameter of ~140 nm, carbon ring diameter of ~100 nm and pitch distance of ~150 nm, synthesized by using a catalytic chemical vapor deposition technology, have been investigated for potential applicability in lithium batteries as anode materials. The electrochemical results demonstrate that the present CNSs are superior anode materials for rechargeable lithium-ion batteries with high-rate capabilities, as well as long-term cycling life. At a current density as high as 3 A g?1, CNSs can still deliver a reversible capacity of 160 mA h g?1, which is about six times larger than that of graphite and three times larger than that of multi-wall carbon nanotubes under the same current density. After hundreds of cycles, there is no significant capacity loss for CNSs at both low and high current densities. The much improved electrochemical performances could be attributed to the nanometer-sized building blocks as well as the unusual spring-like morphology.  相似文献   

17.
Liu  Yang  Su  Zhiqin  Wang  Yong  Shui  Jiaxin  Jin  Zhengfei  Bai  Bing  Qiu  Linlin  Du  Pingfan 《Journal of Solid State Electrochemistry》2023,27(4):969-976
Journal of Solid State Electrochemistry - Due to its high theoretical specific capacity and lower working potential, silicon is regarded as the most promising anode material for the new generation...  相似文献   

18.
Carbon nanotube/cobalt oxide core-shell one-dimensional nanostructures were prepared via a hydrothermal synthesis method, in which nanosize cobalt oxide crystals were homogeneously coated on the surface of carbon nanotubes. The morphologies and crystal structures of the as-prepared core-shell nanocomposites were analysed by X-ray diffraction, field emission gun scanning electron microscopy, and transmission electron microscopy. When applied as anodes in lithium-ion cells, carbon nanotube/cobalt oxide core-shell nanostructures exhibited an initial lithium storage capacity of 1250 mAh/g and a stable capacity of 530 mAh/g over 100 cycles. The good electrochemical performance could be attributed to the nanocrystalline cobalt oxide and the unique core-shell one-dimensional nanostructures.  相似文献   

19.
A tin oxide-titanium oxide/graphene (SnO2-TiO2/G) ternary nanocomposite as high-performance anode for Li-ion batteries was prepared via a simple reflux method. The graphite oxide (GO) was reduced to graphene nanosheet, and the SnO2-TiO2 nanocomposites were evenly distributed on the graphene matrix in the SnO2-TiO2/G nanocomposite. The as-prepared SnO2-TiO2/G nanocomposites were employed as anode materials for lithium-ion batteries, showing an outstanding performance with high reversible capacity and long cycle life. The composite delivered a superior initial discharge capacity of 1,594.6 mAh g?1 and a reversible specific capacity of 1,500.3 mAh g?1 at a current density of 100 mA g?1. After 100 cycles, the reversible discharge capacity was still maintained at 1,177.4 mAh g?1 at a current density of 100 mA g?1 with a high retained rate of reversible capacity of 73.8 %. The addition of small amount of TiO2 nanoparticles improved the cycling stability and specific capacity of SnO2-TiO2/G nanocomposite, obviously. The results demonstrate that the SnO2-TiO2/G nanocomposite is a promising alternative anode material for practical Li-ion batteries.  相似文献   

20.
Fundamental aspects of solving the problem of how the working capacity of lithium-ion batteries in prolonged cycling can be raised and the basic tendencies in the relationship between the intrinsic parameters of active materials of various brands and the electrochemical behavior of anodes and cathodes fabricated from these materials are considered.  相似文献   

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