Abstract: Layered LiNi0.8Co0.1Mn0.1O2 powder was synthesized by reacting quasi-spherical Ni0.8Co0.1Mn0.1(OH)2 prepared by co-precipitation with LiOH×H2O through high temperature sintering route. The obtained powder was characterized by X-ray diffraction (XRD), scanning electronic microscope (SEM), thermogravimetric-differential thermogravimetric analysis (TG-DTG) and constant current charge-discharge cycling. The results revealed that the optimal preparation condition of the layered LiNi0.8Co0.1Mn0.1O2 was 750℃ under oxygen flowing. The XRD pattern of the sample prepared under the above condition could be identified by a typical structure of hexagonal a-NaFeO2 type. The SEM micrograph of LiNi0.8Co0.1Mn0.1O2 showed that a large number of spherical primary particles with an average size of about 500~800 nm piled loosely to form quasi-spherical secondary particles. Electrochemical measurements showed that it delivered an initial discharge capacity of 168.6 mA×h/g during the first charge and discharge cycle, and the first coulombic efficiency was 90.5%, and the discharge capacity in the 20th cycle was 161.7 mA×h/g. The material would be potential cathode material for Li-ion battery.

Key words: lithium ion battery, cathode material, lithium nickel cobalt manganese oxide, layered structure, co-precipitation

摘要： 采用共沉淀法得到前驱体Ni0.8Co0.1Mn0.1(OH)2，利用前驱体与LiOH×H2O的高温固相反应得到高振实密度的锂离子电池层状正极材料LiNi0.8Co0.1Mn0.1O2 (2.3~2.5 g/cm3). 初步探讨了合成条件对材料电化学性能的影响. 通过X射线衍射(XRD)、扫描电镜(SEM)、热重-差热分析(TG/DTG)以及恒电流充放电测试对合成的样品进行了测试和表征. 结果表明，在750℃、氧气气氛下合成的材料具有较好的电化学性能. 通过XRD分析可知该材料为典型的六方晶系a-NaFeO2结构；SEM测试发现产物粒子是由500~800 nm的一次小晶粒堆积形成的二次类球形粒子. 电化学测试表明，其首次放电容量和库仑效率分别为168.6 mA×h/g和90.5%, 20次循环后容量为161.7 mA×h/g，保持率达到95.9%，是一种具有应用前景的新型锂离子电池正极材料.

关键词: 锂离子电池, 正极材料, 锂镍钴锰复合氧化物, 层状结构, 共沉淀法