Electrochemical performance of carbon nanotube-modified LiFePO_4 cathodes for Li-ion batteries  

作　　者：陈召勇 朱华丽 朱伟 张建利 李奇峰 

机构地区：[1]College of Physics and Electronic Science,Changsha University of Science and Technology

出　　处：《Transactions of Nonferrous Metals Society of China》2010年第4期614-618,共5页中国有色金属学报（英文版）

基　　金：Project(06B002)supported by Scientific Research Fund of Hunan Provincial Education Department of China;Project(09JJ3092)supported by Hunan Provincial Natural Science Foundation of China;Project(2008FJ3008)supported by the Planned Science and Technology Project of Hunan Province of China

摘　　要：Carbon nanotubes (CNTs) and acetylene black (AB) were dispersed synchronously or separately between LiFePO4 (LFP) particles as conducting agents during the course of manufacture of LiFePO4 cathodes. The morphology and electrochemical performances of as-prepared LiFePO4 were evaluated by means of transmission electron microscopy (TEM), charge-discharge test, electrochemical impedance spectroscope (EIS) and cyclic voltammetry (CV). CNTs contribute to the interconnection of the isolated LiFePO4 or carbon particles. For the CNTs-modified LiFePO4, it exhibits excellent performance in terms of both specific capacity and cycle life. The initial discharge capacity is 147.9 mA·h/g at 0.2C rate and 134.2 mA·h/g at 1C rate, keeping a capacity retention ratio of 97% after 50 cycles. The results from EIS indicate that the impedance value of the solid electrolyte interface decreases. The cyclic voltammetric peak profiles is more symmetric and spiculate and there are fewer peaks. CNTs are promising conductive additives candidate for high-power Li-ion batteries.Carbon nanotubes (CNTs) and acetylene black (AB) were dispersed synchronously or separately between LiFePO4 (LFP) particles as conducting agents during the course of manufacture of LiFePO4 cathodes. The morphology and electrochemical performances of as-prepared LiFePO4 were evaluated by means of transmission electron microscopy (TEM), charge-discharge test, electrochemical impedance spectroscope (EIS) and cyclic voltammetry (CV). CNTs contribute to the interconnection of the isolated LiFePO4 or carbon particles. For the CNTs-modified LiFePO4, it exhibits excellent performance in terms of both specific capacity and cycle life. The initial discharge capacity is 147.9 mA·h/g at 0.2C rate and 134.2 mA·h/g at 1C rate, keeping a capacity retention ratio of 97% after 50 cycles. The results from EIS indicate that the impedance value of the solid electrolyte interface decreases. The cyclic voltammetric peak profiles is more symmetric and spiculate and there are fewer peaks. CNTs are promising conductive additives candidate for high-power Li-ion batteries.

关 键 词：LIFEPO4 carbon NANOTUBES cyclic VOLTAMMETRY (CV) electrochemical impedance spectroscopy (EIS) LI-ION batteries 

分 类 号：TM912[电气工程—电力电子与电力传动]