Advanced functional materials and their coordinated composites for next-generation Li-S batteries: A brief review

The lithium‑sulfur (LiS) batteries are sanctioned as the most efficient energy storage system because of their exceptionally high energy density with economical production than lithium-ion batteries. The commercialization of LiS batteries is still challenging due to the formation and dissolution of polysulfides defined as "polysulfide shuttling", resulting in a high self-discharge rate. Polysulfide shuttling is considered a major concern primarily attributed to the structural instability of cathode materials. The modification of sulfur cathode with advanced functional materials is gaining popularity to address the mentioned issues. In particular, the utilization of functional composites for the battery components such as cathode, separator, and separator-interlayer/membrane were reviewed. The analysis is organized by focusing on advanced materials, namely, transition-metal dichalcogenide, metal-organic framework, MXene, boron nitride, and carbon materials with their composites, respectively. Additionally, the analysis offers a comprehensive insight into tunable morphology, molecular chemistry, and interfacial functionality through the synergy of advanced materials. Further, the effect of these materials on the shuttling inhibition efficiency like polysulfide entrapment, catalytic conversion capability, charge conduction, and their dominance on electrochemical performance were discussed. This review will provide general insight to the researchers and assist them in the proper direction for the future advancement of LiS batteries.