Modulating the Coordination Environment of Co Single‐Atom Catalysts: Impact on Lithium‐Sulfur Battery Performance

Abstract The coordination environment is crucial to the electrocatalytic activity of single‐atom catalysts (SACs). Although substituting N atoms in traditional transition metal‐nitrogen (TM‐N₄) configuration with other non‐metal atoms has been reported, its specific role in sulfur electrochemical reactions has not been sufficiently investigated. Herein, a Co‐P₂N₂ SACs configuration is fabricated to investigate the mechanistic differences compared to Co‐N₄ in sulfur reduction/oxidation. This configuration enhances the electron transfer with Li₂S₆, where the electrons tend to aggregate between P and Li atoms as two separate parts rather than a single merged zone as observed in symmetric Co‐N₄ SACs. This process facilitates polysulfide decomposition and promotes Li₂S nucleation/oxidation. Furthermore, the CoPNC interlayer effectively suppresses cell self‐discharge and Li anode corrosion due to polysulfide shuttling. Li‐Li symmetrical cell incorporated with the CoPNC interlayer achieves a prolonged lifespan exceeding 1000 h, and Li‐S full cell delivers a discharge capacity of more than 1500 mAh g⁻¹. This research provides insights into how the geometric configuration of SACs influences the performance of conversion‐type batteries.