Strengthened d‐p Orbital‐Hybridization of Single Atoms with Sulfur Species Induced Bidirectional Catalysis for Lithium–Sulfur Batteries

Abstract

AbstractSingle‐atom catalysts (SACs) have been widely explored as additives to improve the performance of lithium–sulfur (Li–S) batteries, however, the design of highly catalytic and in‐depth knowledge of the structure–activity relationship of SACs remains a huge challenge. Herein, electron redistribution of the Co site by introducing the S atom to replace the N atom in the first coordination shell is theoretically predicted to enhance the anchoring capability of lithium polysulfides (LiPSs) and simultaneously facilitate the redox process of Li–S batteries, due to the strengthened d‐p orbital hybridization between sulfur species and SACs compared with the traditional CoN4 architecture. Enlightened by theoretical analysis, asymmetric (N, S) coordinated Co single atoms embedded on N, S‐doped hierarchically porous carbon (S‐Co‐SACs/NSC) is precisely designed and constructed as a high‐efficiency fixity and catalyst for Li–S batteries. Therefore, the battery with S@S‐Co‐SACs/NSC cathode exhibits high areal capacity and cycling stability. This work highlights the vital function of the electronic structures of SACs in promoting the practical application of Li–S batteries.