Comparative studies on ZnO-coated and uncoated LiCoO2 cycled at various rates and temperatures

Abstract

Modification by surface coating of cathode materials is one of the preferred methods to achieve improved electrochemical performance, especially at a high-charge cut-off voltage. In this study, ZnO-coated LiCoO2 powders were prepared by plasma-enhanced chemical vapor deposition (PE-CVD). In our previous work [1], the roles of ZnO coating in the capacity retention of LiCoO2 during high-voltage cycling in the range of 3.0 V-4.5 V and the thermal stability of the charged LiCoO2 electrode were investigated as a function of the coating amount. This study confirms the positive effect of ZnO coating on cyclic performances of LiCoO2, in particular at various C-rates and operating temperatures. In addition, the structural stability of the LiCoO2 materials coated with different amount of ZnO during cycling was investigated using cyclic voltammetry. (C) 2010 Published by Elsevier B.V.