Synergistic Regulation of Hydrogen‐Bond Dynamics and Interfacial Structure by Engineering Additives Toward Stable Aqueous Zinc‐Ion Batteries

Aqueous Zn‐ion batteries (AZIBs) are promising candidates for large‐scale energy storage owing to their intrinsic safety and low cost. However, their practical deployment is severely hindered by Zn anode instability arising from parasitic H 2 evolution, interfacial corrosion, dendrite growth, and by‐product accumulation. Herein, we propose a low‐cost yet multifunctional electrolyte additive, triethylenetetraminehexaacetic acid (TTHA), to regulate Zn ion solvation chemistry and interfacial deposition behavior. In situ/ex situ characterizations combined with theoretical simulations reveal that TTHA partially replaces coordinated H 2 O in the Zn 2+ solvation sheath, suppressing H 2 O activity and mitigating H 2 evolution. Meanwhile, TTHA adsorbs preferentially on the Zn surface, homogenizing interfacial charge distribution, and promoting preferential Zn (002) plane growth. Importantly, TTHA establishes a buffered interfacial environment that effectively retards local alkalization during cycling, thereby inhibiting interfacial corrosion and the formation of basic zinc sulfate. Benefiting from these synergistic effects, Zn||Zn symmetric cells exhibit an ultralong cycling lifespan exceeding 6000 h at 1 mA·cm −2 , while Zn||V 2 O 5 full cells retain 89.2% of their initial capacity after 1000 cycles at 1 A·g −1 and deliver improved rate capability and Coulombic efficiency. This work demonstrates a simple yet highly effective electrolyte engineering strategy and provides new mechanistic insights and a practical pathway toward durable, high‐performance AZIBs.