LiCoO2 cathode material coated with nano-crystallized ZnO for Li-ion batteries

LiCoO2 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 LiCoO2 powders via a wet chemical method. The influence of the amount of coated ZnO on cycling behavior of surface-treated LiCoO2 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 LiCoO2 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 LiCoO2 cathodes deposited with different amount of ZnO exhibited distinct surface morphology and lattice constants. From the correlation between these characteristics of bare and coated LiCoO2 powders, the role of ZnO coating played on the electrochemical performance of LiCoO2 was probed. (C) 2004 Elsevier B.V. All rights reserved.