An Orthogonal Investigation of Sulfur Modified Li2FeSiO4 for Lithium Ion Batteries

Different sulfur modified carbon coated lithium iron silicate (Li2FeSiO4/C) composites were prepared by sol-gel precursor and solid-state reaction using 1-dodecanethiol as a sulfur source material. The effects of sucrose amount, sulfur content, sintering temperature and sintering time on crystal structure, surface morphology and electrochemical performance of sulfur modified Li2FeSiO4/C composites were investigated through orthogonal design experiments. The results of the orthogonal investigation indicated that the significance of the influence on the capacity performance followed the decreasing order as sulfur doping content > sucrose content > sintering temperature > sintering time. The optimized conditions were determined to be: sucrose content of 70%, sulfur doping content of 10%, sintering temperature at 600°C for 7 h.