Synergistic Design of Long-Life Aqueous Zinc Batteries Through Solvation Sheath Reconstruction and Hydrogen-Bond Network Regulation by 3-Pyridinesulfonic Acid

Aqueous zinc-ion batteries (AZIBs) are emerging as a promising candidate for large-scale energy storage systems due to their inherent safety and cost-effectiveness. However, the vigorous growth of dendritic crystals and severe side reactions caused by the decomposition of a large number of active water molecules in aqueous electrolytes significantly hinder their practical application. In this study, 3-pyridinesulfonic acid (3-PSA) molecules were introduced at an optimized concentration as an electrolyte additive for AZIBs. Through a combination of electrochemical characterization and theoretical calculations, it was found that the directed coordination interaction between the sulfonic acid group (−SO₃H) and Zn²⁺ leads to the restructuring of the solvation shell of (Zn(H₂O)₆)²⁺, which adsorbs onto the Zn metal surface, promoting uniform Zn²⁺ deposition and significantly reducing the number of free H₂O molecules. Additionally, the introduction of 3-PSA disrupts the original hydrogen bond network, adjusts the hydrogen bond bond angles, and suppresses water-induced corrosion and side reactions. The Zn//Zn symmetric cell using the designed 50 mM 3-PSA/2 M ZnSO₄ electrolyte demonstrated excellent cycle life (2700 h) under 1 mA cm^–2/1 mAh cm^–2 conditions, while the Zn//MnO₂ full cell achieved 1500 ultrastable cycles under 2 A g^–1 conditions, significantly outperforming the control group using pure ZnSO₄ electrolyte. This study provides new insights and strategies for the engineering design of high-performance AZIB electrolytes.