Template‐Sacrificing Synthesis of Asymmetrically Coordinated Zn Single‐Atom Sites for High‐Performance Sodium–Sulfur Batteries

Abstract Metal single‐atom catalysts (SACs) are extensively investigated to accelerate the sulfur redox kinetics in room‐temperature sodium─sulfur (Na─S) batteries. Nevertheless, the influence of the structure symmetry of SACs center on the electrocatalytic mechanism and the precise pathway in which single‐atom active sites facilitate sodium polysulfides (Na₂S_n) conversion remain unknown. To enable controlled construction of highly active single‐atom configuration, herein, Zn SACs with an asymmetrical Zn─N₃O configuration are designed for sodium polysulfides conversion. Both theoretical and experimental explorations reveal that the Zn─N₃O single‐atom center displays higher electrocatalytic activity for polysulfides conversion than the Zn─N₄ single‐atom center. The N/O co‐coordination induces the localized charge at Zn single‐atom center, which strengthens the d‐p hybridization with Na₂S_n and stretches Na─S bond length of Na₂S_n, thus accelerating the sulfur redox reaction kinetics. Consequently, the as‐assembled Na─S batteries achieve a high capacity of 1016 mAh g⁻¹ at 1.0 C with a capacity decay of 0.0186% per cycle over 1000 cycles. This work uncovers the subtle relationship between the electrocatalytic activity of species conversion and the local coordination environment of SACs, and offers a guidance for the design of efficient asymmetrical SACs for different catalysis applications.