Molecular-Anion Interfacial Engineering for Solid Electrolyte Interphase to Obtain High-Performance Aqueous Zinc-Ion...

Uncontrolled Zn dendrite growth and parasitic interfacial reactions severely undermine the long-term cyclability of aqueous zinc-ion batteries (AZIBs). Herein, an organic-inorganic hybrid multicomponent solid electrolyte interphase (SEI) was constructed on the Zn anode via interfacial engineering, by introducing citric acid (CA) and Zn(OTf)₂ into baseline ZnSO₄ electrolyte. CA preferentially adsorbs and decomposes in the inner Helmholtz layer (IHL) to form a gradient organic outer layer, whereas OTf^- and SO₄ ^2- are reduced and deposited to generate a multicomponent inorganic inner layer (ZnF₂, ZnO, ZnS). This hybrid SEI stabilizes the Zn/electrolyte interface, suppresses corrosion, accelerates interfacial kinetics, and guides uniform Zn²⁺ deposition. Consequently, Zn||Cu cells deliver 99.9% average Coulombic efficiency (CE) over 5500 cycles at 5 mA cm^-2, 1 mAh cm^-2; Zn||Zn symmetric cells cycle stably for over 2438 h at 10 mA cm^-2, 1 mAh cm^-2; Zn||MnO₂ full cells with 149 mAh g^-1 initial capacity retain 88% capacity after 1414 cycles at 1 A g^-1. This work provides an effective strategy to robust interphases for high-performance durable AZIBs.