Highly adhesive hydrogel electrolytes driven by adenosine monophosphate and Fe3+ for high-voltage asymmetric flexible zinc-air batteries

Flexible zinc-air batteries (ZABs) are a promising power source for wearable electronics, owing to their high energy density and low cost. However, the limited operating voltage of about 1.4 V and the complex external packaging of conventional ZABs hinder their practical application. Herein, a hydrogel electrolyte (PAMA-ANa/Fe3+) is rapidly prepared for flexible ZABs using copolymers of acrylamide and acrylic acidic (PAMA), along with sodium adenosine-5'-monophosphate (AMPNa) and Fe3+. By leveraging the synergistic effects of exceptional mechanical properties, strong adhesion and the acidic-alkaline decoupling of the PAMA-ANa/Fe3+ hydrogel electrolyte, an asymmetric flexible ZAB (AF-ZAB) based on an acidic-alkaline double-layer PAMA-ANa/Fe3+ hydrogel electrolyte is assembled in a simple and rapid manner. This AF-ZAB achieves an excellent operating voltage of 2.15 V and a high power density of 75.86 mW cm−2. This study provides a new method and strategy for the development and assembly of novel high-voltage flexible quasi-solid-state batteries and other energy storage devices.