Facile synthesis of MoS2 confined in yolk-shell hollow mesoporous carbon spheres with enhanced polysulfide binding for high-rate Li-S batteries

Abstract

Lithium-sulfur (Li-S) batteries are one of the most potential energy storage systems because of their high theoretical density, environmental friendliness. However, the practical application of Li-S batteries is currently hampered by several intrinsic problems including the shuttle effects of polysulfides and sluggish electrode reaction kinetics. Herein, a flower-like MoS2 nanosheets confined and in situ grown inside yolk-shell hollow mesoporous carbon spheres (abbreviated as MoS2 @YHMCs) was fabricated as advanced sulfur immobilizer, which can effectively inhibit shuttle effect and conversion of polysulfides. The yolk-shell hollow mesoporous carbon spheres can restrain the volume variation during lithiation-delithiation processes, expose abundant active interfaces and furnish a shortened ion/electron transmission route for facilitated redox reactions. Furthermore, the few layered MoS2 nanosheets have strong LiPS adsorption and catalyzation, thereby achieving rapid redox conversion and enhanced reaction kinetics. Owing to these structural advantages, the delicately-designed MoS2 @S@YHMCs cathode shows good Li-S battery performance, i.e., high initial discharge capacity (1145 mAh g−1), desirable rate capability (770 mAh g−1 at 4 C), and superior cycling performance (583 mAh g−1 after 200 cycles at 1 C), suggesting great application prospects in the development of Li-S batteries.