Facile synthesis of micro-spherical LiMn0.7Fe0.3PO4/C cathodes with advanced cycle life and rate performance for lithium-ion battery

摘要

A series of micro-spherical LiMn0.7Fe0.3PO4/C (LMFP) cathode materials are synthesized via co-precipitation method combining spray drying and solid-state reaction. All as-prepared materials are well-characterized to determine their crystal structure, morphology and electrochemical performance. All as-obtained LMFP materials correspond to orthorhombic olivine structure with Pbnm space group and show uniform porous spherical structure with an average particle size of 3 gm and a carbon coating layer of about 3 nm. In particular, the resulting LMFP material prepared at 600 degrees C exhibits a high discharge capacity of 160 mAh g(-1) at 0.1 C. Even at a high rate of 10 C, it can still deliver 133 mAh g(-1) and maintain capacity retention of 84.9% after 200 cycles. The excellent electrochemical performance is ascribed to the synergetic effect of porous micro-spherical structure and uniform carbon coating layer.