Recent Progress of Single-Atom Catalysts for High-Performance Metal-Sulfur Batteries.

Metal-sulfur (M-S) batteries have attracted immense attention as promising candidates for next-generation energy storage, owing to their ultrahigh theoretical energy density, natural abundance, and cost-effectiveness. However, practical commercialization remains impeded by inherent bottlenecks, including sluggish sulfur redox kinetics, metal dendrite growth, and the polysulfide shuttle effect. Single-atom catalysts (SACs) have emerged as a frontier solution, offering maximized atomic utilization, tunable coordination environments, and exceptional electrocatalytic activity. This review systematically summarizes recent advances in SAC-enabled M-S batteries. We first delineate the fundamental electrochemistry of diverse M-S systems, establishing a foundation for the rational design principles and state-of-the-art synthetic methodologies of SACs. Particular emphasis is placed on unraveling intrinsic catalytic mechanisms, highlighting the critical role of d-p orbital hybridization between single-atom metal centers and sulfur intermediates in lowering activation barriers and modulating bidirectional redox kinetics. Building on these mechanistic insights, we critically evaluate SAC applications across a broad spectrum-from conventional Li-S to emerging beyond-lithium systems, including Na-S, Al-S, K-S, Zn-S, and Mg-S batteries. Finally, we provide perspectives on current challenges and future directions to guide rational SAC design for high-energy-density, long-lifespan M-S electrochemistry.