A phytic acid derived LiMn 0.5 Fe 0.5 PO 4 /Carbon composite of high energy density for lithium rechargeable batteries

Abstract

A composite of olivine lithium manganese iron phosphate (LiMn 0.5 Fe 0.5 PO 4 ), external carbon coating and internal embedded carbon flakes, EC-IC-LMFP, is prepared by using phytic acid (PhyA) as phosphorus source via solvothermal process followed by calcination. The composite with improved electronic conductivity and ion diffusivity presents an ultrahigh reversible specific capacity of 193 mAh g −1 at 0.1 C, and an excellent cycling stability of 93% capacity retention after 100 cycles at 1 C when applied as a cathode material for Li-ion batteries (LIBs). Additionally, the composite fine powders exhibit a special microstructure and its volumetric energy density is estimated to reach 1605 Wh L −1 , much larger than the commercial LiFePO 4 .