LiAlO2包覆LiNi0.8Co0.1Mn0.1O2的电化学性能

Electrochemical performance of LiNi0.8Co0.1Mn0.1O2 coated with LiAlO2

采用高温固相法在LiMi0.8Co0.1Mn0.1O2表面包覆一层LiAl02。XRD和SEM分析结果表明:包覆前后的材料均为具有R-3m空间群的α-NaFeO2层状结构;包覆量为1%的样品颗粒表面形成了一层均匀的絮状包覆物LiAl02。电化学性能测试结果表明:包覆量为1%的样品性能较好,以20 mA/g的电流在2.5 -4.3 V充放电,首次放电比容量为165.47 mAh/g,较未包覆材料低17.33 mAh/g,但循环稳定性得到提高,循环30次的容量保持率达90. 88%,高于未包覆材料的59. 71%。

A layer of LiAlO2 was coated on the surface of LiMi0.8Co0.1Mn0.1O2 by high temperature solid phase method. XRD and SEM analysis showed that the materials before and after coating were a-NaFeO2 layered structures with R-3m space group. A uniform floc-like coati ng of LiAlO2 was formed on the surface of the sample particles with 1 % coating amount. The electrochemical performance test showed that the sample with a coating amount of 1 % had better performance ,the first discharge specific capacity at a voltage range of 2.5 to 4.3 V and at a current 20 mA/g was 148.29 mAh/g, which was 17.33 mAh/g lower than the uncoated material, but the cycle stability was improved. The capacity retention rate after the 30 cycles of 2.5 to 4.3 V at a current 20 mA/g was 90.88%, which was higher than 59.71% of the uncoated material.