Coating for improving electrochemical performance of NCM523 cathode for lithium-ion batteries

Abstract

NCM is a promising cathode in lithium-ion battery, but it is suffering from capacity fading during charge and discharge process, especially at elevated temperature. Unstable structure is the main cause. In order to solve the issue, an Al2O3 layer was coated on LiNi0.5Co0.2Mn0.3O2 (NCM523) particle. The X-ray diffraction patterns and scanning electron microscope images show that a nanosized Al2O3 layer is uniformly coated on the surface of NCM523. Electrochemical tests reveal that the optimal coating content is 0.5 wt%, which shows remarkably improved capacity retentions. Al2O3 coating was demonstrated to improve the cycle life of the battery. After long cycling, the Al2O3 layer is still robust enough to prevent NCM particles from the attack of electrolyte.