LiCoO 2 cathode material coated with nano-crystallized ZnO for Li-ion batteries

Abstract

LiCoO 2 is the most widely used cathode material for Li-ion batteries. However, the structural changes and cobalt dissolution into the electrolyte during cycling will lead to rapid capacity fading. Recently, surface modification of the cathode material with metal oxides is found to be a potential approach to improve the electrochemical properties. In this study, nano-crystallized ZnO was coated on the surface of LiCoO 2 powders via a wet chemical method. The influence of the amount of coated ZnO on cycling behavior of surface-treated LiCoO 2 powders was discussed. Moreover, the effect of the pristine-modified powders on the structural properties was also evaluated. The surface morphology characterization was achieved by scanning electron microscope (SEM). Nano-crystallined ZnO was clearly observed on the surfaces of LiCoO 2 particles. The phase and structural changes of the cathode materials before and after coating were revealed by X-ray diffraction (XRD). It was discovered that LiCoO 2 cathodes deposited with different amount of ZnO exhibited distinct surface morphology and lattice constants. From the correlation between these characteristics of bare and coated LiCoO 2 powders, the role of ZnO coating played on the electrochemical performance of LiCoO 2 was probed.