Samarium oxide coating with enhanced lithium storage of regenerated LiNi0.6Co0.2Mn0.2O2

Abstract

Samarium oxide was successfully coated to improve the lithium storage capacity of the regenerated LiNi0.6Co0.2Mn0.2O2 (NCM622) cathode material. The coating amount of samarium oxide was optimized to be 0.5 wt%, and the obtained NCM displayed the best crystallinity and particle morphologies with a uniform coating layer. Higher cycle stability (88.97 % at 1 C after 200 cycles) and almost undamped discharged specific capacity (167.56 mAh g−1, 2.8–4.3 V, 0.1 C) were achieved for NCM with 0.5 wt% samarium oxide, compared with the pristine regenerated NCM622. It was observed that the optimized NCM622 still owned good crystal structure and particle morphologies upon cycling due that the side reactions between the cathode materials and the electrolyte were effectively inhibited by the samarium oxide coating layer. This work provides a new idea for improving lithium storage performance of the spent cathode materials.