Enhancing LiNiO2 cathode materials by concentration-gradient yttrium modification for rechargeable lithium-ion batteries

Lithium nickel oxide (LiNiO2) cathode materials are featured with high capacity and low cost for rechargeable lithium-ion batteries but suffer from severe interface and structure instability. Here we report that rationally designed LiNiO2 via concentration-gradient yttrium modification exhibits alleviative side reactions and improved electrochemical performance. The LiNiO2 cathode with LiYO2-Y2O3 coating layer delivers a discharge capacity of 225 mAh g(-1) with a high initial Coulombic efficiency of 93.4%. These improvements can be attributed to the formation of in-situ modified hybrid LiYO2-Y2O3 coating layer, which suppresses phase transformation, electrolyte oxidation and salt dissociation due to the formation of protective cathode electrolyte interface. The results indicate promising application of concentration-gradient yttrium coating as a facile approach to stabilize nickel-rich cathode materials. (C) 2021 Science Press and Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by ELSEVIER B.V. and Science Press. All rights reserved.

Automated summary

Rationally designed LiNiO2 with concentration-gradient yttrium modification shows alleviative side reactions and improved electrochemical performance, forming a protective cathode electrolyte interface, indicating a promising approach to stabilize nickel-rich cathode materials.