Self-supported MoO2/MoS2 nano-sheets embedded in a carbon cloth as a binder-free substrate for high-energy lithium–sulfur batteries

Abstract

As one of the most prospective candidates for next-generation rechargeable batteries, lithium-sulfur (Li-S) batteries currently still encounter great challenges associated with the low conductivity, severe shuttle effects, and sluggish redox kinetics. Herein, a self-supported sulfur host is fabricated by an in-situ growth of MoO2/MoS2 nano-sheets on a carbon cloth (CC). First, carbon cloth serves as a good template for the morphology-controlled synthesis of nanostructured materials, which not only alleviates the agglomeration of MoO2/MoS2, but also enhances the flexibility and mechanical strengthen of the hybrid architecture as a free-standing host. Second, the polysulfide-trapping ability can be greatly enhanced by both physical and chemical adsorption from the MoO2/MoS2-anchored carbon cloth. Moreover, the partially sulfurized MoO2/MoS2 nano-sheets integrate the benefits of conductive MoO2 and sulfiphilic MoS2, thus facilitating fast charge transfer and redox kinetics of polysulfide conversion. As a result, these attributes enable the host to hold a high sulfur loading (up to 7.6 mg cm−2), which exceeds most of the reported carbon cloth-related cathode work in the literature. Additionally, the Li-S cells can achieve a high peak capacity of 1350 mA h g−1, excellent rate capability (C/20 - 2C rate), impressive areal capacity (up to 6.3 mA h cm−2), and a high capacity retention of 85% after 100 cycles.