Y包覆及温度对高电压钴酸锂性能影响的研究

Study on the Performance of Y Coating and Temperature on High-voltage Lithium Cobaltate

采用高温固相法合成氧化钇(Y2O3)均匀包覆钴酸锂正极材料,研究Y包覆及不同煅烧工艺条件下对二次颗粒的XRD、SEM、PSD、p H、BET及电化学性能的影响。在25℃,3.0~4.6V测试条件下,960℃的二烧工艺,Y包覆材料的电化学性能达到最佳,放电比容量达到191.8mAh/g,在第50圈的容量保持率为90.6%;45℃,3.0~4.55V的放电比容量达到192.4mAh/g,容量保持率在50圈达到95.8%。

The uniform yttrium oxide(Y2O_(3))coated lithium cobaltate cathode materials were synthesized by high temperature solid phase method.The effects of Y coating and different calcining conditions on the XRD,SEM,PSD,pH,BET and electrochemical properties of the composites were investigated.Under the test conditions of room temperature(25℃),3.0~4.6V,the electrochemical performance of Y coated material which was calcined at 960℃ is the best.The discharge specific capacity of Y coated material reaches 191.8 mAh/g,and the capacity retention rate at the 50th cycle is 90.6%.At high temperature(45℃),the discharge specific capacity of 3.0~4.55V reaches 192.4 mAh/g and the capacity retention rate reaches 95.8%in 50 cycles.