Effect of Sintering-method on Electrochemical Performance of LiFePO4/C Cathode Material

Static nitrogen atmospheres (SA), dynamic nitrogen atmosphere (DA) and static vacuum (SV) sintering methods were adopted to synthesize LiFePO4/C cathode material. The crystalline structure, morphology and electrochemical performances of the products were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM) and galvanostatic charge/discharge test. Effects of sintering method on crystallinity, particle size, carbon content, reaction temperature and electrochemical performance of the as-obtained LiFePO4/C cathode material are remarkable. SV-sintered LiFePO4/C have better crystalline, but DA-sintering is helpful to obtain LiFePO4/C particles with smaller particle size and narrower particle size distribution, kinetics of Li+ diffusion is also improved. For the DA-sintered sample, sintering temperature can be reduced to 500 ith excellent electrochemical performance. Specific discharge capacity for the first cycle reaches 163.4 mAh/g at 0.5C rate, and up to 99.02% of discharge capacity can be kept after 50 cycles.