Improved electrochemical performance of high voltage LiCoO2 with Al doping and ZrO2 coating

Surface coating and element doping are the key strategies in LIBs development to achieve a high and stable battery performance. In this paper, ZrO2 is directly sputtered on the Al-doped LiCoO2 (Al-LCO) composite electrodes, enabling a controllable oxide coating on the surface of the electrode. With a sputtered coating layer of ~6 nm, the discharging capacity of the Al doped LCO coated with ZrO2 (Al-LCO-ZrO2) is 141.04 mAh g-1 at the 100th cycle within 3.0-4.7 V at 1 C, while the Al-LCO (without coating layer) is 126.66 mAh g-1. After 100 cycles of charging-discharging at high voltage region, the capacity retention of the Al-LCO-ZrO2-3 (90.7%) is also higher than the Al-LCO (75.57%). It is worth noting that, in this paper, due to the Al doping and the ZrO2 coating, we increase the operation voltage up to 4.7 V, in which the batteries can obtain a higher energy density.