Electrochemical properties of Li-Fe-S ternary metal sulfide (lithium iron sulfide) synthesized via the molten salt method

Abstract

Li-Fe-S ternary metal sulfide (lithium iron sulfide) powder was synthesized by the molten salt method. The physical and electrochemical properties of synthesized lithium iron sulfide were also investigated. From the results of XRD analysis, the chemical composition of synthesized lithium iron sulfide powder was Li(1.7)Fe(1.17)S(2) with a hexagonal crystal structure. The Li/Li(1.7)Fe(1.17)S(2) cell showed a first charge capacity of 153 mAh g(-1)-Li(1.7)Fe(1.17)S(2), corresponding to 48% of theoretical capacity. To understand the charge/discharge reaction behaviors of the Li/Li(1.7)Fe(1.17)S(2) cell, Li/FeS(2), Li/Fe and Li/AB cells were tested. From these results, the charge/discharge mechanism of the Li/Li(1.7)Fe(1.17)S(2) cell was suggested.