LAUSR

For the development of advanced flexible and wearable electronic devices, functional electrolytes with excellent conductivity, temperature tolerance, and desirable mechanical properties need to be engineered. Herein, an alkaline double-network hydrogel with high conductivity, superior mechanical and anti-freezing properties is designed, and promisingly utilized as the flexible electrolyte in all-solid-state zinc-air batteries. The conductive hydrogel is comprised of covalently crosslinked polyelectrolyte poly(2-acrylamido-2-methylpropanesulfonic acid potassium salt) (PAMPS-K) and interpenetrating methyl cellulose (MC) in the presence of concentrated alkaline solutions. The covalently crosslinked PAMPS-K skeleton and interpenetrating MC chains endow the hydrogel with good mechanical strength, toughness, extremely rapid self-recovery capability, and outstanding anti-fatigue property. Gratifyingly, the entrapment of concentrated alkaline solution into the hydrogel matrix achieves extremely high ionic conductivity (up to 105 mS·cm-1 at 25 °C) and excellent anti-freezing capacity. The hydrogel retains comparable conductivity and eligible strength to withstand various mechanical deformations at -20 °C. The all-solid-state zinc-air batteries using PAMPS-K/MC hydrogels as flexible alkaline electrolytes exhibit comparable specific capacity (764.7 mAh·g-1), energy capacity (850.2 mWh·g-1), cycling stability and mechanical flexibility. The batteries still possess competitive electrochemical performances even the operating temperature drops to -20 °C.