Al_2O_3膜表面包覆LiNi_(1／3)Co_(1／3)Mn_(1／3)O_2的微观结构和电化学特性  

Microstructure and Electrochemical Properties of LiNi_(1/3)CO_(1/3)Mn_(1/3)O_2 Coated with Al_2O_3 Film

作　　者：李新禄[1] 康飞宇[1] 白新德[1] 沈万慈[1] 

机构地区：[1]清华大学材料系,北京100084

出　　处：《无机材料学报》2007年第6期1037-1040,共4页Journal of Inorganic Materials

摘　　要：采用液相浸渍法在球形颗粒LiNi_(1/3)Co_(1/3)Mn_(1/3)O_2的表面包覆上了一层Al_2O_3膜.结构分析表明,表面Al_2O_3膜的厚度约100nm,具有一定的无定形结构,核体材料具有纯六方相结构.实验结果证明,表面Al_2O_3膜能够有效提高正极材料的耐过充能力和循环稳定性.在截止电压为3.0～4.5V,充放电倍率为1C的条件下,Al_2O_3表面包覆膜后正极活性物质50次循环的容量保持率提高了11.5%.LiNi1/3Co1/3Mn1/3O2 is considered as a new-generation cathode material for lithium ion batteries. Al2O3 film was coated on the surface of LiNi1/3Co1/3Mn1/3O2 in order to prevent irreversible reactions between cathode and electrolytes. The structure analysis indicates that the Al2O3 film is amorphous with thickness of about 100nm, the core material has a hexagonal structure. The experiment results show that Al2O3 coating is effective to improve overcharge capability and cycle stability. The capacity retention of the coated LiNi1/3Co1/3Mn1/3O2 is increased by 11.5% compared with that of a blank sample after 50 charge-discharge cycles at the cutoff voltage of 3.0-4.5V and 1C rate.

关 键 词：正极材料 表面包覆 锂离子电池 Al2O3膜 

分 类 号：TM911[电气工程—电力电子与电力传动]