Molecular Engineering of Hydrogel Polymer Electrolytes for Climate‐Resilient Rechargeable Batteries

ABSTRACT Aqueous zinc‐ion batteries (AZIBs) face severe performance degradation due to electrolyte freezing at subzero temperatures and water evaporation at elevated temperatures. Here, we developed a temperature‐adaptive hydrogel electrolyte by fluorosilane‐assisted molecular engineering, which maintains stable ion transport and interfacial integrity across extreme thermal conditions. Trimethoxy(3,3,3‐trifluoropropyl)silane (T3) is incorporated into a polyacrylamide matrix for its dual hydrophobic and zincophilic functionalities, simultaneously enhancing interfacial chemistry and reinforcing the polymer network. Benefiting from one‐step in situ polymerization, the temperature‐adaptive hydrogel can be readily scaled into large‐area flexible films (e.g., 27 cm × 27 cm, 0.05 cm thick). The ─CF 3 groups suppress high‐temperature water‐induced side reactions, while Si─O─Si crosslinks and Si─O─Zn bonds facilitate Zn 2+ transport at low temperatures. This dual regulation broadens the thermal operating window, lowering the freezing point from −12.9°C to below −80°C and suppressing volatilization at 80°C. Consequently, Zn||TZFO||Zn cells show extended cycling lifetime (4500 h at 25°C, 7600 h at −20°C, and 1200 h at 40°C), while Zn||TZFO|| NaV 3 O 8 ·1.5H 2 O full cells operate stably across −20°C to 80°C. This work establishes molecular‐level fluorosilane engineering as an effective and scalable route toward all‐climate zinc‐based energy storage.