Surface Modification Engineering Enabling LiMnxFe1−xPO4 Cathode Against Aggressive Cathode Chemistries for Excellent Performance Lithium‐ion batteries

Abstract As an indispensable cathode material for lithium‐ion batteries, LiMn x Fe 1− x PO 4 (LMFP) has garnered significant attention among scholars due to its considerable energy density and remarkable safety characteristics. However, the further advancement of LMFP is hindered by its poor conductivity and limitations in terms of cycle stability. Herein, LiMn 0.6 Fe 0.4 PO 4 @C@Al 2 O 3 (LMFP64/CA) composite materials with core‐shell structure were prepared through simple solvothermal and liquid phase coating methods. The carbon layer can further bolster the structural robustness of the active material, increase conductivity, and facilitate ion and electron transfer; while the Al 2 O 3 layer can function as a protective interface, effectively mitigating the detrimental electrochemical side effects arising from hydrofluoric acid (HF) generated during electrolyte decomposition within a wide voltage range. Consequently, the LMFP64/CA electrode exhibits impressive electrochemical performance including notable reversible capacity (125.1 mAh g −1 at 0.5 C), exceptional rate performance (111.2 mAh g −1 at 1 C), and remarkable cycle stability at 5 C (0.021 % decay rate over 500 cycles).