Improved electrochemical performance of Li1.2Mn0.54Ni0.13Co0.13O2 cathode material coated with ultrathin ZnO

Abstract

Ultrathin ZnO coatings with different thicknesses are successfully deposited onto the layered Li-rich oxide Li1.2Mn0.54Ni0.13Co0.13O2 via atomic layer deposition (ALD) technology, followed by annealing in Ar. The influence of ZnO layer on the structural and electrochemical performances of Li1.2Mn0.54Ni0.13Co0.13O2 cathode material is systematically investigated. In comparison with the pristine one, the ultrathin ZnO-coated electrodes exhibit the significantly improved discharge capacity and cycleability, particularly the LMNCO@ALD-ZnO-20 sample. The remarkably improved electrochemical performance of the coated sample is ascribed to the homogeneous ZnO coatings with high-quality, which could improve the electrode/electrolyte interface stability and the structural stability at high voltage, suppress the increasing charge transfer resistance during cycling, and favour the Li+ diffusion.