Synergy of In Situ Heterogeneous Interphases with Hydrogen Bond Reconstruction Enabling Highly Reversible Zn Anode at −40 °C

Aqueous Zn²⁺ ion batteries (AZIBs) are considered promising candidates for large-scale energy storage systems. However, the critical technical bottlenecks, including Zn dendrite, corrosion reactions, and poor low-temperature performance, significantly impede their commercialization. Here, γ-valerolactone (γ-GVL), a bioactive polar biomass-based green solvent derived from lignocellulose, is introduced into electrolyte as a co-solvent to improve the electrochemical stability of Zn anode and enhance its low-temperature cycling performance. The non-toxic γ-GVL, serving as a strong hydrogen-bonding ligand, coordinates with H₂O to reconstruct the electrolyte's hydrogen bond network, broadening the electrochemical stability window and enhancing the anti-frost properties of aqueous electrolytes. Moreover, γ-GVL facilitates in situ formation of a heterogeneous solid-electrolyte interphase (SEI) composed of ZnF₂ and ZnS inorganic components. The heterogeneous interphases maintain superior ionic conductivity for Zn²⁺ transportation and hydrophobicity for H₂O repulsion, synergistically enabling highly stable and dendrite-free Zn deposition. Consequently, Zn||Zn cells exhibit improved cycling performance across a wide temperature range, achieving an extended cycle life of 5060 h at 25 °C and 2300 h at −40 °C. Zn||VO₂ full cells show enhanced low-temperature cyclability, retaining 97.0% capacity after 300 cycles at −20 °C, demonstrating substantial potential for advancing the commercialization of low-temperature aqueous electrolytes.