Modification of natural graphite using pitch through dynamical melt-carbonization  

作　　者：周友元 李新海 郭华军 王志兴 杨勇 谢巧玲 

机构地区：[1]School of Metallurgical Science and Engineering, Central South University

出　　处：《Journal of Central South University of Technology》2007年第5期651-655,共5页中南工业大学学报（英文版）

基　　金：Project(50302016) supported by the National Natural Science Foundation of China

摘　　要：The graphite was modified using pitch through dynamical melt-carbonization, and the effects of modification temperature and the amount of pitch on the characteristics of graphite were investigated. The structure and characteristics of the graphite were determined by X-ray diffractometry(XRD), scanning electron microscopy(SEM), particle size analysis and electrochemical measurements. The results show that the modified graphite has a disordered carbon/graphite composite structure, larger average particle diameter, greater tap density, and better electrochemical characteristics than the untreated graphite. The sample coated with 10% pitch dynamical melt-carbonized at 400 ℃ for 3 h and heat-treated at 850 ℃ for 2 h has better electrochemical performances with a reversible capacity of 360.5 mA·h/g, a irreversible capacity of 41.0 mA·h/g, and an initial coulombic efficiency of 89.8% compared with natural graphite and disordered carbon. The cycling stability of the Li/C cell with modified graphite as anodes is improved, and its capacity retention ratio at the 30th cycle is up to 94.37%.The graphite was modified using pitch through dynamical melt-carbonization, and the effects of modification temperature and the amount of pitch on the characteristics of graphite were investigated. The structure and characteristics of the graphite were determined by X-ray diffractometry（XRD）, scanning electron microscopy（SEM）, particle size analysis and electrochemical measurements. The results show that the modified graphite has a disordered carbon/graphite composite structure, larger average particle diameter, greater tap density, and better electrochemical characteristics than the untreated graphite. The sample coated with 10% pitch dynamical melt-carbonized at 400 ℃ for 3 h and heat-treated at 850 ℃ for 2 h has better electrochemical performances with a reversible capacity of 360.5 mA.h/g, a irreversible capacity of 41.0 mA.h/g, and an initial coulombic efficiency of 89.8% compared with natural graphite and disordered carbon. The cycling stability of the Li/C cell with modified graphite as anodes is improved, and its capacity retention ratio at the 30th cycle is up to 94.37%.

关 键 词：lithium ion battery GRAPHITE dynamical melt-carbonization anode 

分 类 号：TB321[一般工业技术—材料科学与工程]