Ce-modified LiNi0.5Co0.2Mn0.3O2 cathode with enhanced surface and structural stability for Li ion batteries

The well-established LiNi 0.5 Co 0.2 Mn 0.3 O 2 (NCM523) cathode materials possess a broad prospect for Li-ion batteries. However, the NCM523 still suffers severe capacity fading and structural instability. In this research, Ce-doped and CeO 2 -coated NCM523 cathode materials are synthesized by a smart one-step calcination process. It is found that the CeO 2 coating layer is formed during high-temperature calcination. The CeO 2 coating layers stop the electrode from being exposed to the electrolyte directly and promote the kinetics of lithium deintercalation. Besides, Ce doping could suppress the bulk cation-mixing degree. Electrochemical tests suggest that Ce-modification improves the capacity retention of cathode materials. The optimized Ce-modification cathode material, among 2.7 V and 4.6 V, not only shows the best capacity retention of 76.2%, but also delivers a discharge capacity of 178.2 mAh g −1 at 1 C. This smart modification strategy provides novel ideas for advanced LIBs.