Al2O3包覆Li1.2Mn0.54Ni0.13Co0.13O2富锂正极材料的电化学性能

用溶胶凝胶法制备了Li_1.2Mn_0.54Ni_0.13Co_0.13O₂富锂锰基正极材料，用均匀沉淀法对其进行不同比例Al₂O₃的表面包覆改性，并对其进行XRD、TEM表征和电化学性能分析。结果表明，包覆后的材料保持了原来的层状结构，Al₂O₃均匀地包覆在材料颗粒表面形成纳米级包覆层。在0.1C、2.0~4.8 V条件下Al₂O₃包覆量(质量分数)为0.7%的正极材料首次放电容量为251.3 mAh/g，首次库仑效率达到76.1%，100次循环后容量保持率达92.9%。包覆Al₂O₃抑制了循环过程中的电压衰减，适量的Al₂O₃包覆使正极材料的电化学性能提高。

Electrochemical Performance of Li1.2Mn0.54Ni0.13Co0.13O2 Lithium-enriched Cathode Materials Coated with Al2O3

Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ lithium-rich manganese-based cathode materials were prepared by sol-gel method, then coated with Al₂O₃ by uniform precipitation method, which further characterized by means of XRD, TEM and electrochemical properties analysis. Results show that the coated material still has the layered structure as its original status, Al₂O₃ was uniformly coated on the surface of the Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ particles to form a nano-scale coating. The initial discharge capacity of the Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ powder coated with 0.7% Al₂O₃ was 251.3 mAh/g under the condition of 0.1 C and 2.0~4.8 V. The first coulombic efficiency is 76.1%, and the capacity retention rate is 92.9% after 100 cycles., and the coating also effectively suppresses the voltage decay during the cycle. The proper amount of Al₂O₃ coating can effectively improve the electrochemical performance of the cathode material.