镍钴锰酸锂的制备及高电压充放电性能

摘要

Lithium nickel cobalt manganate materials coated with nano size aluminum oxide (Al2O3)were prepared by a coprecipitation-ball milling-high temperature sintering method,the electrochemical performance was studied under high voltage charge and discharge conditions.The results of XRD,SEM,differential capacity(dQ)/differential voltage(dU) and electrochemical performance tests indicated that the lithium nickel cobalt manganate uniformly coated with nano size Al2O3 could be obtained via this method,the electrochemical performance of the cathode was improved.When cycled in 3.0 ～ 4.6 V with 0.5 C,the specific discharge capacity of cathode coated with 0.5 ％ Al2O3 in the 50th cycle was increased to 172.7 mAh/g from 155.3mAh/g of the uncoated material.The thermal stability of cathode and the constant charge time at high temperature and high voltage were increased via coating treatment,thereby the safety of batteries at high temperature could be improved.%用共沉淀-机械球磨-高温煅烧法制备纳米三氧化二铝(Al2O3)包覆镍钴锰酸锂材料,研究材料在高电压充放电条件下的电化学性能.XRD、SEM、容量微分(dQ)/电压微分(dU)和电化学性能测试结果表明:在镍钴锰酸锂颗粒表面得到了均匀的纳米级Al2O3包覆层,并提高正极材料的电化学性能.以0.5C在3.0～4.6 V循环,Al2O3包覆量为0.5％材料第50次循环的放电比容量由未包覆材料的155.3 mAh/g上升到172.7 mAh/g.包覆处理可提升正极的热稳定性和高电压高温持续充电的时间,从而提高电池的高温安全性能.