Preparation of LiFePO_4/C composite cathode materials by a two-step carbothermal reduction method

Olivine-structured LiFePO4 is a promising cathode material for lithium-ion batteries.A two-step carbothermal reduction method was used in synthesizing LiFePO4 cathode materials in this study.Decreasing high-temperature sintering time of the two-step method restrained the growth of the particle.At the same time,carbon was wrapped on the surface of LiFePO4 particle.And a LiFePO4/C composite cathode material was formed.The results showed that the initial discharge capacity of this sample was 149.4mAh/g at 0.1C rate and the discharge efficiency reached 93.5%.On contrary,the one-step carbothermal reduction sample had an initial discharge capacity for 99.1mAh/g.And the discharge efficiency is 81.4%.Then the mechanism of synthesis reaction and electrochemical result was analyzed.