Preparation of Mesoporous Carbon/Sulfur Composite Loaded with ZnS and Its Property for Lithium-sulfur Batteries

With the aim to obtain high performance cathode materials for lithium-sulfur batteries,composite of mesoporous carbon(MC) loaded with ZnS(ZnS/MC) was prepared through ultrasonic dispersion and heat treatment.The as-prepared composite was blended with elemental sulfur by heating,then cathode materials(ZnS/MC/S) was obtained.The ZnS/MC composite was characterized by XRD,SEM,EDS and N2 adsorption-desorption isotherms.The results showed that ZnS particle was uniformly loaded to the surface of MC through ultrasonic dispersion when content of ZnS was less than 17wt%.ZnS nanoparticles aggregated to form sphalerite ZnS by heat treatment or increasing content of ZnS.Cyclic voltammetry test showed that ZnS accelerated the oxidation process of polysulfides.Charge/ discharge tests indicated that the initial discharge specific capacity was 1354.6 mAh/g,while the coulombic efficiency of the first charge and discharge was 98.7%.The capacity still remained 650 mAh/g after 50 cycles.