Green Phytic Acid-Assisted Synthesis of LiMn 1-x Fe x PO 4 /C Cathodes for High-Performance Lithium-Ion Batteries.

As a promising cathode material, olivine-structured LiMnPO 4 holds enormous potential for lithium-ion batteries. Herein, we demonstrate a green biomass-derived phytic-acid-assisted method to synthesize a series of LiMn 1-x Fe x PO 4 /C composites. The effect of Fe doping on the crystal structure and morphology of LiMnPO 4 particles is investigated. It is revealed that the optimal Fe doping amount of x = 0.2 enables a substantial enhancement of interfacial charge transfer ability and Li + ion diffusion kinetics. Consequently, a large reversible capacity output of 146 mAh g -1 at 0.05 C and a high rate capacity of 77 mAh g -1 at 2 C were acquired by the as-optimized LiMn 0.8 Fe 0.2 PO 4 /C cathode. Moreover, the LiMn 0.8 Fe 0.2 PO 4 /C delivered a specific capacity of 68 mAh g -1 at 2 C after 500 cycles, with a capacity retention of 88.4%. This work will unveil a green synthesis route for advancing phosphate cathode materials toward practical implementation.