Sol-gel synthesis of Li2FeSiO4/C

Abstract

Lithium transition-metal orthosilicates with general formula Li2MSiO4 (M = Fe, Mn, Co, etc.) have attracted a lot of interest due to their potentially high theoretical capacities arising from the possibility of the extraction of two Li-ions per formula unit. Li2FeSiO4 takes prominent position among this family of compounds due to its structural stability and natural abundance of iron. In this study, Li2FeSiO4/C composite was synthesized by simple method which involves rapid heating, short high-temperature delay, and subsequent quenching. Starting materials were Li2CO3, Fe(NO3)3·9H2O, Si(OC2H5)4 (TEOS) and water-soluble methylcellulose. Precursor preparation is based on the sol-gel processing and provides homogenous mixing at the molecular level. Structural analysis, morphology examination and electrochemical test of thus obtained powder were performed.