Cooperative Bulk‐Interface Regulation Through Na/F/Al Functional Synergy Enables Structural and Interfacial Stability in Li‐Rich Layered Oxides

ABSTRACT Lithium rich manganese layered oxides (LRMs) are promising cathode materials for high energy lithium‐ion batteries owing to their high capacity and low cost, yet their practical applications are limited by lattice degradation and unstable cathode electrolyte interphase (CEI) evolution during cycling. Herein, a fluorine enriched multifunctional Li 1.2 Mn 0.54 Ni 0.13 Co 0.13 O 2 (LRM) is constructed through Na + , F − , and Al 3+ synergistic regulation to achieve bulk surface stabilization. The introduction of Na + broadens Li interlayer spacing and accelerates Li + transport, while Al‐O bonding stabilizes the local electronic structure, suppresses cation disorder and Jahn‐Teller distortion, and alleviates lattice strain. Furthermore, the preformed fluorine enriched surface region reinforces the outer lattice through the formation of robust F‐TM bonds, promoting the generation of a uniform and stable CEI layer, mitigating electrolyte decomposition and interfacial reactions. The optimized NFA‐LRM delivers a high discharge capacity of 318.7 mAh g −1 at 0.1 C, with reversible capacities of 140.6 and 108.5 mAh g −1 at 5 C and 10 C, respectively, and retains 96.29% capacity after 250 cycles at 2 C. This work provides a bulk and surface synergistic strategy for high energy LRMs with stabilized oxygen chemistry and durable interfacial stability.