Enhanced electrochemical and thermal stability of surface-modified LiCoO2 cathode by CeO2 coating

CeO2-coated LiCoO2 particles were successfully synthesized by a sol-gel coating of CeO2 on the surface of the LiCoO2 powder and subsequent heat treatment at 700 C for 5 h. The surface-modified and pristine LiCoO2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Auger electron spectroscopy (AES), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Cyclic voltammetry curves suggested that the CeO2 coating suppressed the phase transitions. Unlike pristine LiCoO2, the CeO2-coated LiCoO2 cathode exhibited better capacity retention than the pristine LiCoO2 electrode in the higher cutoff voltage. Differential scanning calorimetric data revealed the higher thermal stability of the CeO2-coated LiCoO2 electrode. (c) 2005 Published by Elsevier Ltd.