Synthesis and Electrochemical Properties of LiFe (PO₄)_(1-x/3)F_x/C as a Cathode Material

Abstract

on doping is an effective means to improve the performance of LiFePO4 material. In the present study, composites LiFe (PO4)(1-x/3)Fx/C (x=0.00,0.02,0.04,0.06,0.08,0.10) were synthesized by carbothermal reduction method. The as-synthesized samples were characterized by X-ray diffraction and scanning electron microscope, and their electrochemical performances were investigated by constant current charge-discharge experiment. The results indicated that the low concentration F dopant did not affect the structure of LiFePO4 but considerable improved its electrochemical performances. The LiFe (PO4)0.98F0.06/C materials showed better electrochemical performances than LiFePO4/C. At 0.2 C discharging rate, the LiFe (PO4)0.98F0.06/C materials was capable of delivering reversible specific capacity of 165.1 mAh/g, with fairly stable cycleability. The excellent performance indicates that this mix-doped composite was a very promising cathode material for lithium ion batteries.