Surface Modification of Single‐Crystalline Ni‐Rich Cathode Materials with Gallium Oxide for High‐Voltage Electrochemical Cycling

Elongated lithium diffusion lengths, parasitic interfacial reactions, and rapid capacity fading continue to hinder the practical application of single‐crystalline Ni‐rich Li[Ni x Co y Mn 1− x − y ]O 2 (SC NCM) cathodes. Although existing surface modification strategies enhance electrochemical stability, high charge transfer resistance and low lithium diffusion result in poor cycling performance. In this work, a lithiophilic Ga 2 O 3 surface‐coated SC NCM material with 83% Ni content is synthesized for the first time via a wet chemical and postannealing route. The Ga 2 O 3 ‐coated material delivers 149.54 mAh g −1 with 57.33% retention after 300 cycles at 1 C over a potential window of 3.0–4.5 V. Compared to the uncoated counterpart, the modified material exhibits a 37.50% reduction in charge transfer resistance and a 79.20% increment in lithium diffusion. Moreover, the nonfaradaic electrochemical active surface area shows only a 1.1% reduction after extended cycling, suggesting effective interfacial stabilization and possible mitigation of HF‐induced surface degradation. These findings demonstrate that the surface modification of NCM materials with lithiophilic Ga‐based oxides is an effective strategy to enhance Li transport, suppress interfacial side reactions, which results in much improved electrochemical performance for next‐generation lithium‐ion batteries.