Stabilization of a 4.7 V High‐Voltage Nickel‐Rich Layered Oxide Cathode for Lithium‐Ion Batteries through Boron‐Based Surface Residual Lithium‐Tuned Interface Modification Engineering

Abstract Residual lithium on the surface and the resulting side reactions for high‐energy‐density Ni‐rich layered oxide cathodes principally impede their industrial application and trigger safety concerns. Herein, the successful construction of LiBO 2 −B 2 O 3 co‐modified single‐crystal LiNi 0.6 Co 0.2 Mn 0.2 O 2 (SC‐NCM) as a lithium‐ion battery (LIB) cathode is reported. Boric acid reacts with the surface residual lithium species to form such uniform coating on the SC‐NCM particles, which presents advanced rate and cycling capabilities. As the cathode materials for LIBs, LiBO 2 −B 2 O 3 co‐modified SC‐NCM delivers a 141.9 mAh g −1 discharge specific capacity at 5 C between 3.0 and 4.5 V versus Li + /Li with 61.4 % capacity retention after 500 cycles, superior to the 20.8 % retention for the pristine SC‐NCM cathode. Besides, the LiBO 2 ‐B 2 O 3 protective layer substantially inhibits the unexpected phase transformation, effectively alleviates the mechanical microcracks, and stabilizes the cathode‐electrolyte interface, even at an extended operational potential window. The proposed microstructure‐modified SC‐NCM cathode provides an affordable and feasible design strategy for Ni‐rich SC‐NCM cathodes towards stable electrochemical performance and prolonged service life at high potential.