Recent Advances of Metal Groups and Their Heterostructures as Catalytic Materials for Lithium-Sulfur Battery Cathodes

Lithium-sulfur (Li-S) batteries have an extremely high theoretical capacity and energy density and are considered to be among the highly promising energy storage systems for the next generation. However, the slow redox kinetics of sulfur and the "shuttle effect" caused by lithium polysulfides (LiPSs) result in batteries with extremely low coulombic efficiency and poor cycling stability, which severely hinders the commercialization of Li-S batteries. Up to date, numerous works have shown that the introduction of polar catalytic materials into the cathode is an effective strategy to improve battery performance, especially metal-based compounds, which not only strongly anchor LiPSs and suppress the shuttle effect, but also accelerate the redox process of sulfur. Theoretical calculations, especially the most widely applicable density functional theory (DFT) calculation, play an indispensable role in understanding the anchoring and conversion behavior of LiPSs on substrates, and it can predict the potential performance of materials and provide strategies for the rational design of LiPS anchoring materials. Based on this perspective, this paper highlights the DFT work conducted on this topic for metal compound materials, and reviews their recent progress as catalytic materials for Li-S battery cathodes, including metal oxides, metal sulfides, metal selenides, metal carbides, metal nitrides, other metal compounds and the composed heterostructures. Finally, we summarize the research directions and challenges of polar material applications and put forward personal suggestions, aiming to provide guidance for the wider application of metal compounds in the Li-S battery field. Graphic Abstract