Mechanism study of enhanced electrochemical performance of ZrO2-coated LiCoO2 in high voltage region

In this study, the mechanism of enhanced performance of ZrO2-coated LiCoO2 especially at high potential range is systematically investigated. Firstly, when overcharging to 4.5 V (higher than 4.2 V, the normal cutoff charging potential), phase transformation from H1 to H2 takes place with less volume expansion for ZrO2-coated LiCoO2 (1.2% and 2.2% for as-received one). EIS analysis indicates the growth of interfacial impedance during...