富锂正极材料0.5Li_2MnO_3·0.5LiCoO_2的熔盐法合成及改性  

Synthesis and modification of Li-rich cathode material 0.5Li_2MnO_3·0.5LiCoO_2 by molten salt method

作　　者：赵煜娟[1] 任文锋[1] 吴锐[1] 孙玉成[1] 岳影影[1] 

机构地区：[1]北京工业大学环境与能源工程学院,北京100124

出　　处：《现代化工》2013年第8期53-57,59,共6页Modern Chemical Industry

基　　金：北京市教育委员会科技创新平台面上项目(JC005012201101)

摘　　要：通过熔盐法合成富锂正极材料0.5Li2MnO3.0.5LiCoO2,以低熔点盐为原料,低温熔融混合,分别研究了不同热处理方式和锂配比对富锂正极材料0.5Li2MnO3.0.5LiCoO2的结构、形貌和电化学性能的影响。结果表明:采用化学计量比的锂盐,低温200℃预处理后,高温短时间处理,可以得到粒径均一和层状结构良好的材料。为了提高材料的循环性能,通过熔盐法对富锂正极材料0.5Li2MnO3.0.5LiCoO2进行氟离子掺杂。结果表明:氟离子掺杂后,材料的循环性能和倍率性能均得到提高;同时,在大电流下,氟离子掺杂减缓了容量缓升现象,缩短了活化时间。Li-rich cathode material 0.5Li2MnO3·0.5LiCoO2 is prepared by molten salt method,using raw materials with low melting point and mixing at low temperature.The influences of various sintered temperatures and different lithium contents on crystal structure,morphology and electrochemical properties of Li-rich cathode material are performed.Powders with homogenous sizes distribution and well layer structure are obtained when sample sinters at 850℃ for short time after preheated at 200℃ and uses stoichiometric amounts of Li source.In order to improve cycling performance,Li-rich material 0.5Li2MnO3·0.5LiCoO2 is modified by fluorinion-doping using molten salt method.The results show that cycling and rate performance are improved.At the same time,the phenomenon of capacity increasing with cycles is relieved after fluorinion-doping,and the time of activation is shortened at high current density.

关 键 词：锂离子电池 0 5Li2MnO3·0 5LiCoO2 熔盐合成 氟离子掺杂 

分 类 号：O646[理学—物理化学]