Stretchable, anti-drying, and self-healing hydrogel electrolytes for thermal adaptive zinc–air batteries with robust electrolyte/electrode interfaces

Abstract

Hydrogel electrolytes possessing excellent elasticity and ionic conductivity have garnered significant attention in the realm of flexible zinc–air batteries (ZABs). Nonetheless, the inherent issue of hydrogel electrolyte dehydration when exposed to air, particularly under high temperatures, poses a significant obstacle to the practical application of hydrogel-based ZABs. To address this challenge, a novel hydrogel electrolyte is fabricated by polymerization of (3-acrylamidopropyl) trimethylammonium chloride (ATAC)/ethylene glycol (EG) solution containing polyacrylic acid (PAA). The hydrogen bonds between poly (ATAC) (PATAC) with EG and PAA chains can supply dynamic network that imparts outstanding self-healing properties to the hydrogel electrolytes. Moreover, the presence of water molecules, firmly bound and confined within the dense hydrogen bond networks, endows the hydrogel electrolytes with a unique anti-drying characteristic even at high temperatures. Additionally, the adhesion capability allows the hydrogel electrolytes to form a tight bond with the electrodes. Consequently, the resulting zinc–air batteries exhibit superior electrochemical stability under various deformations and elevated temperatures of 50 °C. This study introduces a promising avenue for the development of flexible zinc–air batteries that demonstrate superior performance and adaptability to environmental conditions.