Regulation of Proton Vehicle Migration for Synergetic Interfacial Stability Enables Long‐Lasting Ah‐Level Zinc‐Ion Batteries

Abstract

Abstract The practical implementation of aqueous zinc‐ion batteries (AZIBs) is critically constrained by interfacial instabilities caused by parasitic hydrogen evolution reaction (HER) and uncontrolled zinc (Zn) dendrite growth, both of which originate from the facile Grotthuss‐type proton diffusion along hydrogen bond (H‐bond) networks. Here, a molecular‐level strategy to disrupt this diffusion pathway is reported through the incorporation of pyridinium trifluoroacetate (PyF), which is an ionic liquid additive enriched in H‐bond donors and acceptors. This PyF additive reconstructs the H‐bonding landscape in the bulk, thereby slowing proton mobility and inducing a translation to a high‐barrier vehicle‐type mechanism. Thus, a proton‐poor and Zn 2+ ‐rich electric double layer is generated, thereby suppressing the HER and promoting dendrite‐free electrodeposition. Simultaneously, trifluoroacetate ion undergoes preferential reduction to form a hybrid organic/inorganic solid electrolyte interphase, further reinforcing the interfacial stability during dynamic cycling conditions. Expectedly, Zn//Zn symmetric cells achieve an exceptional cycling stability of 3900 h, while the Zn//NaV 3 O 8 pouch cell with a capacity of 1.15 Ah maintains stable operation over 50 cycles at 0.2 A g −1 . This work offers a generalizable and scalable electrolyte engineering approach to address the intrinsic challenges of aqueous Zn metal anodes, paving the way toward high‐performance, low‐cost, and durable aqueous energy storage systems.