Construct a Quasi‐High‐Entropy Interphase for Advanced Low‐Temperature Aqueous Zinc‐Ion Battery

Abstract The advancement of aqueous zinc‐ion batteries (AZIBs) faces significant obstacles due to the typically loose and unstable solid electrolyte interphase (SEI), which fosters dendrite formation and undermines cycling performance, especially in cold environments. Here, a quasi‐high‐entropy solid electrolyte interphase (QHE‐SEI) formulated is introduced with diverse and functional inorganic compounds, achieved through the incorporation of dual salts and a blend of solvents. Shielded by the QHE‐SEI, AZIBs exhibit uniform zinc deposition and attain remarkable cycling stability, enduring for 1300 h in Zn||Zn symmetric cells under conditions of 3 mA cm −2 and 3 mAh cm −2 at room temperature. Furthermore, the full cell maintains over 4300 cycles at −20 °C with nearly full capacity retention. Notably, the pouch cell maintains a high capacity of ≈25 mAh across 50 cycles, even at −20 °C. This study offers a novel approach to designing a stable SEI and elevates the performance of AZIBs.