论文部分内容阅读
The Li-rich layered Li[Li0.2Ni0.2Mn0.6]O2 was prepared by co-precipitation and solid state reaction method,then coated with ZnO (Zn(CH3COO)2·2H2O as coating source).Several characterization techniques were used to investigated the effect of ZnO coating on the crystal structures,morphology and electrochemical performance of Li-rich material Li[Li0.2Ni0.2Mn0.6]O2,and the electrochemical impedance spectroscopy (EIS) was used to discuss the improved mechanism of ZnO coating.The results showed that ZnO particles was homogeneously covered on surface of Li[Li0.2Ni0.2Mn0.6]O2,and the electrochemical performance was remarkably improved after ZnO coating,the 1wt.% ZnO coated sample exhibited superior cycle performance and rate capability among the samples,The 1wt.% ZnO-coated Li[Li0.2Ni0.2Mn0.6]O2 sample delivered initial discharge capacity of 253.2 mAh·g-1 at 20mA·g-1 (0.1 C) in the range of 2.0 to 4.8 V,the discharge capacity maintained 211.6 mAh·g-1 after 40 cycles at 0.2C.