Ultralow Concentration Zwitterionic Additives Enable Rapid Adsorption Equilibrium Promoting Long‐Life Aqueous Zinc‐Ion Battery

Aqueous zinc-ion batteries (AZIBs) face challenges in practical applications due to unstable electrode-electrolyte interfaces and zinc dendrite growth. This study introduces an ultra-low concentration (5 mmol L⁻¹) zwitterionic additive, Pyridinium-1-Propane-3-sulfonate (PPS), to reconstruct the electric double layer (EDL) and regulate zinc surface reactions. Compared with structurally similar ionic additive N-Butylsulfonicpyridinium (BSO₃Py) and imidazole-based zwitterionic additive 3-(1-Methyl-1H-imidazol-3-ium-3-yl) propane-1-sulfonate (MPS), PPS exhibits superior parallel adsorption on zinc. Its dynamic adaptation to Zn²⁺ deposition achieves rapid adsorption equilibrium, optimizing zinc active site utilization. Sulfonic acid groups form a robust interfacial layer through intermolecular interactions, while the hydrophobic pyridine ring blocks water/sulfate contact. Symmetric batteries with PPS achieved 700 hours of cycling at 20 mA cm⁻² and cumulative plating capacity exceeding 7000 mAh, alongside 99.81% Coulombic efficiency at 5 mA cm⁻². Zn-VO₂ full batteries retained 247.46 mAh g⁻¹ after 1200 cycles at 5 A g⁻¹. This interfacial engineering strategy provides a scalable solution for stable AZIBs.