Enabling the Strengthened Structural and Interfacial Stability of High‐Nickel LiNi 0.9 Co 0.05 Mn 0.05 O 2 Cathode by a Coating‐Doping‐Microstructure Regulation Three‐In‐One Strategy

High‐nickel layered cathodes exhibit great promise in advancing high‐energy‐density batteries owing to their significant advantages in high energy capacity and low cost, but they suffer severe structural and interfacial deterioration during cycling, resulting in safety risk and reduced cycle life. Herein, drawing inspiration from the low melting point infusion capability of Sb 2 Se 3 , a three‐pronged strategy aimed at simultaneously achieving coating on primary and secondary particles surface, Sb doping and elongated and slimed primary particle morphology is proposed and developed to fortify the structural and interfacial stability of high‐nickel LiNi 0.9 Co 0.05 Mn 0.05 O 2 (NCM90) cathode. The “melted and infused” Sb 2 Se 3 plays a beneficial role in the defensive effect on primary and secondary particle's surfaces, mitigating the interfacial deterioration. In addition, the enhanced structural stability is achieved by both Sb 5+ doping and regulated primary particle morphology, contributing to the alleviated particle breakage and ultimately reinforced cycling stability. Consequently, the Sb 2 Se 3 ‐NCM90 electrodes significantly improve cycling performance, which maintain higher capacity retentions of 96.6% at 4.3 V after 100 cycles and 80.2% at 1C/5C after 500 cycles. The proposed coating‐doping‐microstructure regulation three‐in‐one strategy for improving the cycling stability of high‐nickel NCM cathodes offers innovative ideas for the design and advancement of high‐energy‐density lithium‐ion batteries.