Co(OH)2包覆LiNi0.85Co0.10Mn0.05O2的电化学性能  

Electrochemical performance of Co(OH)2 coated LiNi0.85Co0.10Mn0.05O2

作　　者：高玉仙 龙君君 丁楚雄 李道聪 GAO Yu-xian;LONG Jun-jun;DING Chu-xiong;LI Dao-cong(Hefei Guoxuan High-Tech Power Energy Co.,Ltd.,Hefei,Anhui 230011,China)

机构地区：[1]合肥国轩高科动力能源有限公司,安徽合肥230011

出　　处：《电池》2020年第4期347-351,共5页Battery Bimonthly

基　　金：国家重点研发计划项目(2016YFB0100301);安徽省科技重大专项项目(18030901080)。

摘　　要：用氢氧化亚钴[Co(OH)2]包覆高镍三元正极材料LiNi0.85Co0.10 Mn0.05O 2,控制烧结温度,使Co(OH)2分解为四氧化三钴(Co 3O 4)。半电池测试显示:包覆材料首次循环的放电比容量为202.4 mAh/g、库仑效率为87.7%,均高于未包覆材料。全电池测试显示:包覆材料制备的电池高温(45℃)循环性能更好,以0.50 C充电、1.00 C放电在2.80~4.20 V循环300次,容量保持率为93.3%,而未包覆材料制备的电池为90.2%。电位滴定和SEM分析表明:包覆的Co(OH)2在烧结过程中能与LiNi0.85Co0.10Mn0.05O2的表面残碱(LiOH/Li 2CO3)反应,降低表面残碱含量。XRD测试显示:包覆材料的Ni/Li混排降低,微观应变减小。电化学阻抗谱显示:包覆材料的电荷转移阻抗降低,因此具有更好的电化学性能。Nickel-rich ternary cathode material LiNi0.85Co0.10Mn0.05O2 was coated with cobalt hydroxide[Co(OH)2],Co(OH)2 was decomposed into cobalt oxide(Co 3O 4)by controlling sintering temperature.The half cell test showed that the specific discharge capacity was 204.4 mAh/g and the Coulombic efficiency was 87.7%for the coated material in initial cycle,higher than the uncoated material.The full battery test showed that the performance of the battery prepared with the coated material had better high temperature(45℃)cycle performance,with 0.50 C charge and 1.00 C discharge in 2.80-4.20 V,the capacity retention after 300 cycles was 93.3%,while the capacity retention of the battery prepared with the uncoated material was 90.2%.The potentiometric titration and SEM analyses indicated that the coated Co(OH)2 could react with the surface residual alkali(LiOH/Li 2CO 3)of LiNi0.85Co0.10Mn0.05O2 material during sintering process,which reduced the surface residual alkali content.XRD test showed that Ni/Li mixing and strain G of the coated material decreased.Electrochemical impedance spectroscopy demonstrated that the charge transfer resistance of the coated material was decreased,made the better electrochemical performance.

关 键 词：氢氧化亚钴[Co(OH)2] LiNi0.85Co0.10 Mn0.05O2 包覆 Ni/Li混排 

分 类 号：TM912.9[电气工程—电力电子与电力传动]