Anchoring and Catalytic Effects of rGO Supported VS2 Nanosheets Enable High-Performance Li-Organosulfur Battery.

Abstract

As a high-energy-density cathode material, organosulfur has great potential for lithium batteries. However, their practical application is plagued by electronic/ionic insulation and sluggish redox kinetics. Hence,ourstrategy is to design a self-weaving, freestanding host material by introducing reduced graphene oxide-supported VS2 nanosheets (VS2 -rGO) and carbon nanotubes (CNTs) for lithium-phenyl tetrasulfide (Li-PTS) batteries. Unique host materials not only provide physicochemical confinement of active materials to boost the utilization but also catalyze the conversion of active materials to accelerate redox kinetics. Therefore, Li-PTS cell based on the 3D VS2 -rGO-CNTs (VSGC) host material shows excellent cyclability, with a slow capacity decay rate of 0.08% per cycle over 500 cycles at 0.5 C, and a high areal capacity of 3.1 mAh cm-2 with the PTS loading of 7.2 mg cm-2 . More importantly, the potential for practical applications is highlighted by the flexible pouch cell with a high areal capacity (4.1 mAh cm-2 ) and a low electrolyte/PTS ratio (3.5µLmg-1 ). This work sheds light on elevating the electrochemical performance of Li-organosulfur batteries through the effective catalytic and adsorbed host material.