Effects of surface modification on the cycling stability of LiNi0.8Co0.2O2 electrodes by CeO2 coating

A high-performance LiNi0.8Co0.2O2 cathode was successfully fabricated by a sol–gel coating of CeO2 to the surface of the LiNi0.8Co0.2O2 powder and subsequent heat treatment at 700 °C for 5 h. The surface-modified and pristine LiNi0.8Co0.2O2 powders were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), slow rate cyclic voltammogram (CV), and differential scanning calorimetry (DSC). Unlike pristine LiNi0.8Co0.2O2, the CeO2-coated LiNi0.8Co0.2O2 cathode exhibits no decrease in its original specific capacity of 182 mAh/g (versus lithium metal) and excellent capacity retention (95% of its initial capacity) between 4.5 and 2.8 V after 55 cycles. The results indicate that the surface treatment should be an effective way to improve the comprehensive properties of the cathode materials for lithium ion batteries.