Progress and Strategies of MOFs in Catalyzing Conversion Processes in Lithium-Sulfur Batteries

Lithium-sulfur (Li−S) batteries have attracted considerable attention due to their advantages, such as high specific capacity, high energy density, environmental friendliness, and low cost. However, the severe capacity fading caused by shuttle effect of polysulfide needs to be addressed before the practical application of Li−S batteries. Crystalline porous materials including MOFs have generated great interest in energy storage fields especially batteries, because the ordered porous frameworks can offer a fast-ionic transportation. Nevertheless, the intrinsic low conductivity of MOFs limits their rapid development in lithium-sulfur batteries. This review mainly discusses the latest research progress on MOF main materials in Li−S batteries. The working principle of Li−S batteries and the classical “adsorption-catalysis-conversion” strategy are briefly introduced. Specifically, three modification methods (non-metal atom doping, single-atom, and dual-atom doping modifications) applied in MOF-based materials are analyzed and summarized, along with their respective mechanisms and advantages and disadvantages. Ligand doping is an effective strategy that can regulate the structure and properties of MOFs, thereby enhancing their catalytic activity and adsorption capacity towards polysulfides. Through ligand doping, key parameters such as the pore size, surface charge, and active site density of MOFs can be controlled, thereby influencing the adsorption and conversion of polysulfides on MOFs surfaces. Furthermore, crucial insights for the rational design of advanced MOF-based materials for lithium-sulfur batteries and the exploration of the main challenges and future directions for their application were also discussed.