Anion‐Tailored Asymmetry Engineering in Doped Molybdenum Dichalcogenide Catalysts for Lithium–Sulfur Batteries

ABSTRACT Lithium–sulfur (Li─S) batteries are hindered by lithium polysulfide (LiPS) shuttling and sluggish redox kinetics, demanding catalysts that both anchor LiPS and accelerate their conversion. Here, we introduce anion‐tailored asymmetry engineering of MoS 2 via controlled Se and Te substitution. The intrinsic size mismatch of S/Se/Te induces lattice and electronic asymmetry, weakening in‐plane covalent bonds and creating localized electronic states. In addition, the dual effects lead to more exposure of additional edge sites and activates inert basal planes, enabling concurrent catalytic activity. Consequently, the optimized MoS 1.75 Te 0.25 –S cathode delivers an initial capacity of 1486.2 mAh g −1 (0.1 C) and 537.6 mAh g −1 (1.0 C) after 3000 cycles and 382.9 mAh g −1 after 3000 cycles at 3.0 C, indicating an ultralow decay rate of 0.012% per cycle. Even at a high sulfur loading, it sustains robust capacity retention, underscoring strong practical promise. These results establish anion‐tailored asymmetry engineering as a generalizable strategy, providing mechanistic insights and design principles for advanced Li─S batteries.