Metallic MoS2 Nanoflowers Decorated Graphene Nanosheet Catalytically Boosts the Volumetric Capacity and Cycle Life of Lithium-Sulfur Batteries

High sulfur loading is the key to achieve high energy density promised by Li-S batteries. However, serious problems such as poor rate performance and cycle stability are exposed during the scaling up of the sulfur loading. Systematic modification of both the cathode and separator has the potential to address these issues by enhancing the adsorption and catalytic conversion of polysulfides. Herein, sulfur-deficient metallic 1T-MoS2 nanoflowers decorated graphene (FM@G) is proposed to be systematically modified on both cathode and separator. The as-developed cell exhibits superior cyclability with a capacity retention of 71.7% over 500 cycles. Importantly, steady cyclability and high volumetric capacity of 1360 mAh cm(-3) with a high sulfur loading of 5.1 mg cm(-2) are also attained even at high current density of 4.27 mA cm(-2). The electrochemical performance is comparable to or even superior to the state-of-the-art carbon-based sulfur batteries. This work provides valuable guidance for the implementation of high-energy-density Li-S batteries furnished with high sulfur loading.