摘要
层状三元材料LiNixCoyMn1-x-yO2(以下简称NCM)具有较高的比容量和工作电压平台及良好的倍率性能,在电动汽车领域占据重要地位。为满足电动汽车续航里程的需求,提高工作电压被视为提升三元锂离子电池能量密度的一种有效手段。然而现存电解液电化学窗口窄,无法实现高电压下的稳定循环。本综述对高工作电压下的NCM电池电解质进行探讨,从电解液在高工作电压下分解相关的前线轨道理论及电极与电解液界面反应出发,指出了提高三元正极材料锂离子电池高压工作性能的关键,总结了近年来高工作电压下三元正极材料锂离子电池非水系电解质在溶剂、锂盐、添加剂等方面的设计进展以及固态电解质和离子液体在高工作电压下NCM电池中的应用。最后对电解液在高工作电压下的实际应用提出改进方案,对未来固态电解质的发展趋势提出展望。
LiNixCoyMn1-x-yO2(NCM) cathodes have large reversible capacity, high operating voltage,and good rate capability, which are essential in the field of electric vehicles(EVs). The requirements of endurance mileage of electric vehicles can be met by increasing the energy density of lithium-ion batteries for which the cut-off working voltage must be increased. However, the narrow electrochemical window of current electrolytes could result in poor cycle performance at high voltage. This review focuses on NCM battery electrolytes under high working voltage. Starting from the frontier orbital theory related to the decomposition of electrolytes and the interface reactions between electrodes and electrolytes, this review identifies approaches to improve the high-voltage working performance of lithium-ion batteries with ternary positive materials. Moreover, the design progress of non-aqueous electrolytes in solvents, Li salts, additives and other aspects and the application of solid electrolytes and ionic liquids in NCM batteries at high working voltages are summarized. Finally, improvement strategies are proposed for the practical application of electrolytes under high working voltage and the development trend of solid electrolyte in the future is prospected.
作者
毛舒岚
武倩
王卓雅
陆盈盈
MAO Shulan;WU Qian;WANG Zhuoya;LU Yingying(School of Chemical and Biological Engineering,Zhejiang University,Hangzhou 310027,Zhejiang,China)
出处
《储能科学与技术》
CAS
CSCD
2020年第2期538-550,共13页
Energy Storage Science and Technology
关键词
锂离子电池
镍-钴-锰三元正极材料
高电压电解质
正极-电解质界面
lithium ion batteries
nickel-cobalt-manganese ternary cathode materials
high voltage electrolytes
cathode-electrolyte interface
