Abstract: LaF3 coated LiNi1/3Co1/3Mn1/3O2 cathode material was prepared by coprecipitation method. The synthesized material was characterized by means of X-ray diffraction (XRD), scanning electron microscope (SEM) and galvanostatic charge/discharge cycling. The XRD data of the product show that they are single phases and retain the layered LiNi1/3Co1/3Mn1/3O2 structure. The synthesized the photocatalytic activity of 0.59% LaF3 coated LiNi1/3Co1/3Mn1/3O2 exhibits a good overcharge tolerance property with initial discharge specific capacity of 172.7 mAh/g and the discharge specific capacity of 163.5 mAh/g after 50 cycles in the voltage range 2.75~4.50 V at a constant current density of 0.3 mA/cm2.

Key words: Lithium-ion batteries , Cathode material , Surface modification

摘要：  以ＬｉＮｉ_１／３Ｃｏ_１／３Ｍｎ_１／３Ｏ_２为正极材料，采用共沉淀合成方法制备ＬａＦ_３表面修饰ＬｉＮｉ_１／３Ｃｏ_１／３Ｍｎ_１／３Ｏ_２正极材料，利用Ｘ射线衍射（ＸＲＤ）、扫描电镜（ＳＥＭ）和电化学测试等方法对合成材料的结构、形貌以及电化学性能进行表征。结果表明：经过ＬａＦ３表面修饰的ＬｉＮｉ_１／３Ｃｏ_１／３Ｍｎ_１／３Ｏ_２材料保持了ＬｉＮｉ_１／３Ｃｏ_１／３Ｍｎ_１／３Ｏ_２层状结构，其中ＬａＦ_３表面修饰量为０．５９％时，在电压为２．７５～４．５０Ｖ范围内，以０．３ｍＡ／ｃｍ２ 电流密度下经恒电流充放电测试，其首次放电比容量为１７２．７ｍＡｈ／ｇ，经过５０周充放电循环后放电比容量为１６３．５ｍＡｈ／ｇ，表现出较高的初始放电比容量和良好的抗过充电性能。

关键词: 　锂离子电池 , 　正极材料 , 　表面修饰