Improving the electrochemical performance of Ni-rich cathode materials using a fast ion conductor coating of Li2O–B2O3–LiBr

Abstract The high-Ni layered metal oxide, LiNi0.8Co0.1Mn0.1O2 (LNCM811), has received widespread attention in the energy field because of its high specific capacity, but its large-scale applications are hindered due to severe capacity fading. Herein, a uniform and thin Li2O–B2O3–LiBr-glass (LBBrO-glass) coating was deposited on LNCM811 by a liquid-phase coating and thermal treatment method. The experimental results suggested that the LBBrO-glass coating acted as a protective layer that inhibited transition metal dissolution and side reactions, which helped improve the electrochemical properties of LNCM811. Remarkably, after 200 cycles, the 2 wt% coating (LBBrO@LNCM-2) delivered a superior capacity retention of 88.9%, while only 71.8% was obtained for the pristine material (LNCM811). The discharge capacity of LBBrO@LNCM-2 was 163.5 mAh g−1 at 5C, while it was only 139 mAh g−1 for the pristine material.