Interface-engineered electrolyte-electrode design with lithium nitrate for durable aqueous zinc-ion batteries in sustainable energy applications

Aqueous zinc-ion batteries (AZIBs) are promising candidates for next-generation large-scale renewable energy storage systems owing to their intrinsic safety, cost-effectiveness, and environmental compatibility. However, their practical deployment is limited by dendritic zinc growth, hydrogen evolution, and unstable electrolyte-electrode interfaces, which reduce cycle life and operational reliability. In this work, we present an interface-engineered electrolyte-electrode composite approach utilizing lithium nitrate (LiNO₃) as a multifunctional additive to regulate Zn²⁺ solvation and promote controlled deposition. Through competitive ligand coordination, NO₃⁻ anions partially replace H₂O and SO₄²⁻ ligands in the Zn²⁺ solvation shell, enabling enhanced ionic mobility, uniform metal deposition, and suppressed ZnSO₄ aggregate formation. Optimized LiNO₃ concentration (0.075 wt.%) yields Zn||Ti half-cells with over 500 stable cycles and an average Coulombic efficiency of 99.7%, while Zn||Zn symmetric cells exhibit dendrite-free operation exceeding 1300 h even under high current densities. Complementary molecular dynamics simulations and experimental characterization reveal preferential deposition along the Zn (002) crystal plane and the formation of a robust, Li₃N-containing solid-electrolyte interphase, improving interfacial conductivity and corrosion resistance. Full-cell tests with MnO₂ cathodes demonstrate an initial specific capacity of 263 mAh g⁻¹, retaining 65% after 300 cycles at 1 A g⁻¹, with Coulombic efficiency consistently above 99.7%. This composite interface design strategy provides a scalable pathway for engineering durable zinc-based batteries, directly supporting the development of high-performance, long-life energy storage modules for grid-level renewable integration and other engineering applications.