锂离子电池富锂锰基正极材料的研究进展  

Research Progress in Li-Rich Manganese-Based Cathode Material for Li-Ion Battery

作　　者：刘祥欢 庄卫东[1] 彭敏[1] 王振尧[1] 卢世刚[1] 

机构地区：[1]北京有色金属研究总院国联汽车动力电池研究院有限责任公司,北京101407

出　　处：《稀有金属》2017年第5期534-552,共19页Chinese Journal of Rare Metals

基　　金：国家自然科学基金项目(51302017);科技部国家重点研发计划项目(2016YFB0100401)资助

摘　　要：富锂锰基正极材料x Li2Mn O3-(1-x)Li MO2(M=Ni,Co,Mn,0<x<1)具有放电比容量高(>250 m Ah·g-1)、成本低、对环境友好等特点,是有潜力的下一代锂离子电池用正极材料。但是该材料的首次不可逆容量高、循环和倍率性能较差,尤其是充放电循环过程中放电中压不断降低,阻碍了其实际应用。研究者通过采用表面包覆、表面处理、元素掺杂以及制备特殊的形貌等方法,极大地提升了富锂锰基正极材料的电化学性能。然而,对该材料是固溶体还是两相纳米复合的结构存在争议。另外,对材料中的O元素和Mn元素是否可逆地参与电化学反应尚无定论。本文主要从材料结构、脱嵌锂机制和材料改性(表面包覆、表面处理、掺杂以及特殊形貌的材料制备)等几个方面综述了锂离子电池富锂锰基正极材料的研究进展,并提出了下一步的研究方向。Li-rich manganese-based layered oxide （LLO） xLi2MnO3-（ 1 - x） LiMO2 （ M = Ni, Co, Mn, 0 〈 x 〈 1 ） has the potential to be the cathode material for the next generation Li-ion battery, due to its high discharge specific capacity （ 〉 250 mAh-g-l） , low cost and environment-friendly characteristics. However, it suffers from some problems, such as low initial coulombic efficiency, poor cycle performance, unsatisfactory rate performance and voltage fade during cycling, which hinder its practical application. Until now, the electrochemical performance of LLO have been greatly improved by means of coating, surface treatment, doping and preparation of special structures. The structure of LLO is either a solid solution or a two-phase nanocomposite, which is still controversial. Moreover, it is unclear whether the oxygen and manganese in LLO can be reversibly involved in the electrochemical reaction during its charge-dis- charge cycling. In this paper, the research progress in the structure, charge-discharge mechanism and modification of Li-rich manga- nese-based cathode material was reviewed, and the further research direction was proposed.

关 键 词：富锂锰基正极材料 结构 脱嵌锂机制 改性研究 锂离子电池 

分 类 号：TM912[电气工程—电力电子与电力传动]