Preparation of 2% Sulfur Doped Li2FeSiO4/C with High Performance for Lithium Ion Batteries

Wednesday, 4 October 2017
Prince George's Exhibit Hall D/E (Gaylord National Resort and Convention Center)
X. Luo, Q. Lin, W. Guan, C. Zhang, W. Cao, X. Cheng, and Y. Zhang (Xiamen University)
Capability of obtaining high capacity by exchanging more than one lithium ion has made lithium iron silicate (Li2FeSiO4) very attractive to be an ideal cathode material for lithium ion batteries. However, high deintercalation voltage and large deformation of Li2FeSiO4 are expected during the delithiation of the second lithium ion. In this work, the nominal 2% sulfur doped carbon coated Li2FeSiO4 composite was prepared by sol-gel precursor and solid-state reaction method. A well crystallized Pmn21 and P21 mixed phase was formed. The initial discharge capacity of 229.2 mAh/g was obtained at 0.1C and room temperature, which corresponds to 1.38 moles per formula unit. The capacity fluctuated to 185.6 mAh/g after 50 cycles, achieving the capacity retention of 81%.