LiCo_(0.90)Al_(0.1)O_2的表面包覆及其性能研究

Study of Al_2O_3 coated LiCo_(0.90)Al_(0.1)O_2 as cathode materials for lithium ion batteries

通过化学处理方法在LiCo0.90Al0.1O2的表面包覆后,在300℃下热处理6 h,得到表面包覆Al2O3的LiCo0.90Al0.1O2。SEM分析表明,包覆前表面光滑,包覆后可以明显看到晶粒表面粘有许多小颗粒。当充电到4.5 V时,包覆后的材料具有较好的充放电平台、较高的充放电容量和首次充放电效率,但是包覆后材料的首次充电容量有所下降。

The surface of LiCo0.90Al0. 1O2 was modified with Al2O3 by a chemical processing procedure followed by heat treatment at 300 ℃ in air for 6 h. SEM demonstrated that the surface of uncoated LiCo0.90Al0.1O2 was very smooth, while the surface of coated LiCo0.90Al0.1O2 was not smooth with many particles. The surface modified LiCo0.90Al0. 1O2 samples showed much better charge and discharge capacity as well as the efficiency than the uncoated LiCoO2 cathode to higher cutoff charge voltage of as high as 4.5 V,though the first charge capacities of the surface modified LiCo0.90Al0.1 O2 samples were decreased.