Electrochemical Properties of Yolk-Shell-Structured Zn-Fe-S Multicomponent Sulfide Materials with a 1:2 Zn/Fe Molar Ratio

Yolk-shell-structured Zn-Fe-S multicomponent sulfide materials with a 1:2 Zn/Fe molar ratio were prepared applying a sulfidation process to ZnFe2O4 yolk-shell powders. The Zn-Fe-S powders had mixed sphalerite (Zn,Fe)S and hexagonal FeS crystal structures. The discharge capacities of the Zn-Fe-S powders sulfidated at 350 degrees C at a constant current density of 500 mA g(-1) for the first, second, and fiftieth cycles were 1098, 912, and 913 mA h g(-1), respectively. The powders exhibited a high discharge capacity of 602 mA h g(-1) even at the high current density of 10 A g(-1). The synergistic effect of yolk-shell structure and multicomponent composition improved the electrochemical properties of Zn-Fe-S powders.