An intrinsically self-healing and anti-freezing molecular chains induced polyacrylamide-based hydrogel electrolytes for zinc manganese dioxide batteries

The anti-freezing strategy of hydrogels and their self-healing structure are often contradictory, it is vital to break through the molecular structure to design and construct hydrogels with intrinsic anti-freezing/self-healing for meeting the rapid development of flexible and wearable devices in diverse service conditions. Herein, we design a new hydrogel electrolyte (AF/SH-Hydrogel) with intrinsic anti-freezing/self-healing capabilities by introducing ethylene glycol molecules, dynamic chemical bonding (disulfide bond), and supramolecular interaction (multi-hydrogen bond) into the polyacrylamide molecular chain. Thanks to the exceptional freeze resistance (84% capacity retention at −20 °C) and intrinsic self-healing capabilities (95% capacity retention after 5 cutting/self-healing cycles), the obtained AF/SH-Hydrogel makes the zinc||manganese dioxide cell an economically feasible battery for the state-of-the-art applications. The Zn||AF/SH-Hydrogel||MnO2 device offers a near-theoretical specific capacity of 285 mA h g−1 at 0.1 A g−1 (Coulombic efficiency ≈100%), as well as good self-healing capability and mechanical flexibility in an ice bath. This work provides insight that can be utilized to develop multifunctional hydrogel electrolytes for application in next generation of self-healable and freeze-resistance smart aqueous energy storage devices.