Synergistic modulation of ion transport and structural stability for Li-rich Mn-based cathodes in lithium-ion batteries

Li-rich Mn-based layered oxides (LRMOs) are promising high-energy-density cathode materials for lithium-ion batteries due to their unique anionic/cationic redox mechanisms. However, a series of serious issues including irreversible oxygen release, structural degradation and sluggish kinetics significantly hinder their practical applications. Herein, a dual-functional B/Al co-doping strategy was proposed to synergistically address these challenges. It was found that the robust B − O and Al − O bonds can effectively stabilize the structural framework, mitigating irreversible oxygen release and phase transitions. Concurrently, B-doping optimized Li + transport channels while co-doping induced the formation of surface oxygen vacancies, thereby enhancing Li + transport kinetics. Based the synergistic effects, the electrochemical properties of LRMOs have been improved. As a result, Li 1.2 Mn 0.56 Ni 0.2 B 0.02 Al 0.02 O 2 cathode delivered an initial capacity of 256.8 mAh g −1 at 0.1C and retained 85.1 % of capacity after 500 cycles at 1C, which are much better than pristine and single-doped counterparts. Moreover, the voltage decay rate has been minimized to 0.96 mV cycle −1 , demonstrating an exceptional structural reversibility. Thus, such a work highlights the critical role of synergistic cation co-doping in balancing structural stability and ion transport, offering a viable pathway for developing high-energy and long-life Li-rich cathodes.