Innovative synergy of BF co-doping and modified HAP@PP separator for high-performance LMFP batteries

LiMn 0.8 Fe 0.2 PO 4 (LMFP) cathode has emerged as a promising candidate for high-energy–density lithium-ion batteries due to its cost-effectiveness, high voltage plateau and intrinsic safety. However, drawbacks such as low electrical conductivity, Jahn–Teller effect and Mn 2+ dissolution severely limit its application potential. Herein, we propose a strategy that couples B-F co-doping with HAP@PP separator modification to simultaneously boost the conductivity of LMFP and mitigate Mn 2+ leaching using a facile solid-phase method. The optimized LiMn 0.8 Fe 0.2 P 0.99 B 0.01 O 3.97 F 0.03 (LMFP-BF1) exhibits superior rate capability and excellent cycle stability, which delivers a discharge capacity of 137.4 mAh g −1 and retains 92.6% of that capacity at 1C after 300 cycles. Moreover, HAP@PP separator exhibits an excellent manganese capture effect, which reduces the precipitation of manganese content from 134.647 to 14.056 mg kg −1 . The LMFP-BF1|HAP@PP cell remains a discharge capacity of 140.6 mAh g −1 at 0.5–45 ℃ after 100 cycles, with a capacity retention rate of 88.31%. This study offers insights into integrating ion doping and separator modification for phosphate-based high-energy–density lithium-ion batteries. Graphical abstract B-F co-doping and modified HAP@PP separator can simultaneously boost the conductivity of LMFP and mitigate Mn 2+ leaching, delivering superior cycling stability.