Modulating the Coordination Environment of Co Single‐Atom Catalysts: Impact on Lithium‐Sulfur Battery Performance
Yi Li, Zhaoyang Chen, Xinyu Zhong, Tiehan Mei, Zhao Li, Yue Liang, Jin‐Lin Yang, Hong Jin Fan, Maowen Xu
Abstract
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‐N 4 ) configuration with other non‐metal atoms has been reported, its specific role in sulfur electrochemical reactions has not been sufficiently investigated. Herein, a Co‐P 2 N 2 SACs configuration is fabricated to investigate the mechanistic differences compared to Co‐N 4 in sulfur reduction/oxidation. This configuration enhances the electron transfer with Li 2 S 6 , 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‐N 4 SACs. This process facilitates polysulfide decomposition and promotes Li 2 S 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.