Integrated bulk-interphase synergy strategy for structural integrity and high-rate durability in lithium-rich manganese cathodes

Lithium-rich manganese-based cathodes provide high capacity through coupled cationic and anionic redox; however, their practical utilization is restricted by severe interfacial parasitic reactions, oxygen evolution, voltage fading, and structural deterioration under high-voltage operation. Here, a coordinated integrated bulk-interphase synergy strategy is introduced to concurrently regulate lattice stability and electrolyte reactivity. Surface co-doping with aluminum and phosphate species adjusts the local coordination environment and alters the oxygen electronic structure, while C₆₀ is incorporated as a functional electrolyte additive to scavenge reactive oxygen species and govern interphase evolution. The modified configuration shows suppressed oxygen vacancy generation, moderated lattice fluctuations during high-voltage activation, and decreased gas evolution. Electrochemical measurements demonstrate improved initial reversibility, enhanced high-rate capability, and markedly extended cycling stability. In situ impedance analysis suggests restrained development of interfacial resistance and stabilized charge-transfer kinetics. Post-cycling characterizations verify reduced transition-metal dissolution, alleviated layered-to-spinel transformation, and retention of surface morphology. Simulation analysis further associates improved lithium concentration uniformity with reduced stress accumulation within cathode particles. These findings indicate that coupling bulk structural reinforcement with interphase chemistry regulation offers an effective pathway to mitigate oxygen-related degradation and improve the electrochemical durability of lithium-rich cathodes under demanding operating conditions.