Designing metal sulfide-based cathodes and separators for suppressing polysulfide shuttling in lithium-sulfur batteries

Lithium-sulfur (Li-S) batteries, known for their high energy density, are attracting extensive research interest as a promising next-generation energy storage technology. However, their widespread use has been hampered by certain issues, including the dissolution and migration of polysulfides, along with sluggish redox kinetics. Metal sulfides present a promising solution to these obstacles regarding their high electrical conductivity, strong chemical adsorption with polysulfides, and remarkable electrocatalytic capabilities for polysulfide conversion. In this review, the recent progress on the utilization of metal sulfide for suppressing polysulfide shuttling in Li-S batteries is systematically summarized, with a special focus on sulfur hosts and functional separators. The critical roles of metal sulfides in realizing high-performing Li-S batteries have been comprehensively discussed by correlating the materials’ structure and electrochemical performances. Moreover, the remaining issues/challenges and future perspectives are highlighted. By offering a detailed understanding of the crucial roles of metal sulfides, this review dedicates to contributing valuable knowledge for the pursuit of high-efficiency Li-S batteries based on metal sulfides.