Improving ZnS Oxidation Kinetics Through Nucleophilic Regulation for High‐Performance Zinc–Sulfur Batteries

Abstract Aqueous zinc–sulfur (Zn─S) batteries represent a promising technology for grid‐scale energy storage because of the advantages of environmental friendliness, low cost, and high theoretical capacity. However, the practical applications of Zn─S batteries are hindered by the sluggish oxidation kinetics of zinc sulfide (ZnS) during the charge process. Herein, a strategy of nucleophilic regulation is proposed to modulate the oxidation kinetics of ZnS by adjusting the Zn─S bonding strength. By screening different nucleophilic groups, it is found that tetramethylene sulfone (TMS) can not only strongly interact with Zn atoms of ZnS through sulfone group to lower the oxidation energy barrier but also effectively suppress the side reactions by shielding ZnS from the active water molecules, thus facilitating the complete conversion from ZnS to sulfur. Benefiting from these advantages, the aqueous Zn─S batteries assembled with TMS as a multifunctional electrolyte additive demonstrate a superior specific capacity of 799 mAh g −1 at a current density of 2.0 A g −1 and 649 mAh g −1 at a current density of 4.0 A g −1 with an enhanced capacity retention after long cycles. This work demonstrates the promise of nucleophilic regulation for modulating the cathode conversion reaction in aqueous Zn─S batteries and beyond.