Bioinspired extreme environment adaptive hydrogel enabled by weakening hydrogen bonding

Abstract

Most reported hydrogel electrolytes exhibit incompatible electrolyte-electrode interface, overhigh modulus, extreme environment inadaptation, high costs and toxic residual. Inspired by moisturizing and ductile properties from skin, this study presents a cost-effective, low-toxicity and self-healing hydrogel electrolyte composed of gelatin, lignin sulfonate and LiBr. The hydrogen bonds within hydrogel electrolyte were significantly weakened by LiBr, thereby exhibiting ultra-soft properties under the fracture stress of 8.5 kPa and strain of 1558%, retaining an elongation of 1030% after instantaneous self-healing, and remaining electrolyte-electrode interface stable. Additionally, abundant disordered hydrogen bonds and remarkable hydration capability of the hydrogel electrolyte endowed the ultra-high ionic conductivity (1.26 mS/cm at -50 °C) and adaptability under extreme environment. Notably, the assembled supercapacitor remains effectively electrochemical performance from severe dehydration to ambient environment. This work provides insights for design of flexible hydrogel electrolytes with excellent environmental adaption.