Regulating Water Activity for All‐Climate Aqueous Zinc‐Ion Batteries

Abstract

Suppressing the water activity is challenging to achieve high‐performing aqueous zinc ion batteries (AZIBs), especially for its practical climate adaptability. Reconstructing the H‐bond network and repealing the solvation water can effectively reinforce the covalency inside water molecular. Here, a hydrogel electrolyte formula utilizing ClO4− anions and hydrophilic ─NH2 on polyacrylamide chains is shown to bond with water molecules, while the zincophilic glucose preferentially regulate Zn2+ solvation. The multifunctional hydrogel structure can effectively disrupt the intrinsic H‐bond network and inhibit the interface side‐reactions induced by active water. Finally, the delayed freezing point and expanded voltage stability window are realized, which promotes the ZIBs steady operate in a wide temperature range. When operating at 70 and −30 ˚C, the Zn//NVO battery achieves high specific capacity of 488 and 254 mAh g−1, respectively, surpassing most of the previously reported results. Remarkably, the pouch battery delivers the state‐of‐the‐art specific capacity of 438.1 mAh g−1 and realizes a capacity retention of 76.3% after 400 cycles at 200 mA g−1.