PDF《SiO/CNTs：新型锂离子电池负极材料》

1 个高频区半圆和一段低频区斜线构成. 前者对应于 活性物质的电荷转移阻抗, 后者则对应于锂离子在 材料体相中的扩散阻抗. 与SiO 相比, SiO/CNTs 复合 电极高频区半圆直径显著减小, SiO/CNTs 复合材料 电极的电荷转移阻抗明显小于纯 SiO 电极. 由于 CNTs 的包覆, SiO/CNTs 复合电极的导电网络能够保 持其完整性, 电极中活性颗粒与 CNTs 之间、活性颗 粒之间的接触电阻减小, 有利于电化学反应的进行. EIS 结果进一步证明, 使用柔韧性高、导电性好的 CNTs 作缓冲层, 能够改善 SiO 电极的循环性能和导 电性. 图5充放电前 SiO、SiO/CNTs 电极交流阻抗图谱

4 结论 采用具有高理论储锂容量的一氧化硅作基体, 任玉荣等: SiO/CNTs:新型锂离子电池负极材料

1596 价格便宜的甲烷作碳源, 使用镍作催化剂, 通过易于 工业化生产的化学气相沉积方法低温制备了碳纳米 管包覆的 SiO/CNTs 复合材料. CNTs 的包覆作用, 使得SiO/CNTs 保持了良好的导电网络, 用作锂离子电 池负极材料, 表现出优于 SiO 的循环性能, 循环性能 和首次库仑效率还需进一步提高. 致谢 本工作得到中国科学院知识创新工程重要方向项目 (批准号:KJCX2-YW-M01)、国家科学技术部重 大科学研究计划项目课题 (编号: 2006CB932703) 和成都中科来方能源科技有限公司资助, 特此一并 致谢. 参考文献

1 Yamamoto H, Miyachi M, Kawai H S. Abstracts of the Electrochemical Society of Japan

2004 Spring Meeting, Yokohama, 2004:

204 2 Yang J, Takeda Y, Imanishi N, Capiglia C, Xie J Y, Yamamoto O. SiOx-based anodes for secondary lithium batteries. Solid State Ion- ics, 2002, (152-153): 125―129

3 Miyachi M, Yamamoto H, Kawai H, Ohta T, Shirakata M. Analysis of SiO anodes for lithium-ion batteries. J Electrochem Soc, 2005, 152(10): A2089―A2091

4 Beaulieu L Y, Eberman K W, Turner R L, Krause L J, Dahn J R. Colossal reversible volume changes in lithium alloys. Electrochem Solid-State Lett, 2001, 4(9):137―140

5 Guo Z P, Wang J Z, Liu H K, Dou S X. Study of silicon/polypyrrole composite as anode materials for Li-ion batteries. J Power Sources, 2005, 146(1-2): 448―451

6 Kim B C, Uono H, Satou T, Fuse T, Ishihara T, Ue M. Cyclic properties of Si-Cu/carbon nanocomposite anodes for Li-ion secondary batteries. J Electrochem Soc, 2005, 152(3): A523―A526

7 Lee H Y, Lee S M. Carbon-coated nano-Si dispersed oxides/graphite Composites as Anode material forLithium ion Batteries. Elec- trochem Commun, 2004, 6(5): 465―469

8 Morita T, Takami N. Nano Si cluster-SiOX-C composite material as high-capacity anode material for rechargeable lithium batteries. J Electrochem Soc, 2006, 153(2): A425―A430

9 Yang X, Wen Z, Xu X, Lin B, Huang S. Nanosized silicon-based composite derived by in situ mechanochemical reduction for lithium ion batteries. J Power Sources, 2007, 164(2): 880―884

10 Zhang T, Gao J, Zhang H P, Yang L C, Wu Y P, Wu H Q. Preparation and electrochemical properities of core-shell Si/SiO nano- composite as anode material for lithium ion batteries. Electrochem Commun, 2007, 9(5): 886―890

11 Kim J H, Sohn H J, Kim H, Jeong G, Choi W. Enhanced cycle performance of SiO-C composite anode for lithium-ion batteries. J Power Sources, 2007, 170(2): 456―459

12 Shu J, Li H, Yang R Z, Shi Y, Huang X J. Cage-like carbon nanotubes/Si composite as anode material for lithium ion batteries. Elec- trochem Commun, 2006, 8(1): 51―54

13 Kim T, Mo Y H, Nahm K S, M S O. Carbon nanotubes (CNTs) as a buffer layer in silicon/CNTs composite electrodes for lithium secondary batteries. J Power Sources, 2006, 162(2): 1275―1281