高能量密度层状富锂锰基正极材料的改性研究进展  

Progress in the modification of lithium-rich manganese-based layered cathode material

作　　者：李雨 赵慧春 白莹[1] 吴锋[1] 吴川[1] LI Yu;ZHAO Huichun;BAI Ying;WU Feng;WU Chuan(Beijing Key Laboratory of Environmental Science and Engineering,School of Material,Beijing Institute of Technology,Beijing 100081,China)

机构地区：[1]北京理工大学材料学院,环境科学与工程北京市重点实验室,北京100081

出　　处：《储能科学与技术》2018年第3期394-403,共10页Energy Storage Science and Technology

基　　金：国家重点基础研究发展计划项目(973)(2015CB251100)

摘　　要：纯电动汽车以及混合动力汽车的快速发展使得研发高能量密度的锂离子电池正极材料迫在眉睫。层状富锂锰基正极材料比容量可达250 mA·h/g,平均放电电压高于3.5 V,电化学特征明显优于钴酸锂和磷酸铁锂等传统的正极材料,是实现300 W·h/kg动力锂离子电池极具潜力的正极材料。不过,此类材料循环性能不佳,并伴随严重的电压衰退现象,主要原因是随着循环的进行材料表面结构重组,晶体结构发生了由层状结构向尖晶石结构的不可逆转化,导致锂离子迁移阻力增大,进而严重影响其电化学性能。为解决这些问题,近年来研究人员开展了大量工作,本文主要从体相掺杂、表面包覆、材料微观结构设计以及晶面调控4个方面详细评述了锂离子电池富锂锰基正极材料改性技术的研究进展。Developing the high energy density cathode materials for lithium ion batteries is the key to satisfy the demands of rapid development of electric vehicles and hybrid electric vehicles.Compared with traditional cathodes including LiCo02 and LiFeP04,layered Li-rich Mn-based cathode materials are expected to achieve the index requirement of 300 W.h.kg-1 because their specific capacity could reach up to 250 mA.h.g_1 and the average discharge voltage exceeds 3.5 V.However,Li-rich materials have a poor cycle performance and gradual voltage decay during cycling,which is due to the irreversible phase transition from layered to spinel.In recent years,researchers have carries out tremendous works to solve these issues.In this paper,according to modification technology,the current studies including lattice doping,surface coating,designs of microstructure and control of active crystal plane are reviewed.

关 键 词：富锂锰基正极材料 锂离子电池 改性 电压衰退 循环稳定性 

分 类 号：TM911[电气工程—电力电子与电力传动]