A flexible, autonomous self-healing and high ionic conductivity hydrogel electrolyte for all-in-one supercapacitor

Conventional polyvinyl alcohol-based gel electrolytes are generally limited in ionic conductivity and cannot well meet the requirements of the self-healing and flexible smart device. Herein, we design a highly conductive hydrogel electrolyte (ionic conductivity up to 84 mS cm−1), based on cross-linked aqueous acrylamide (AAm) solution in the presence of poly(N-vinylpyrrolidone) (PVP), with excellent self-healing capability by intermolecular hydrogen bonds between PVP and PAM. The self-healing all-in-one flexible supercapacitor fabrication with the gel electrolyte and in-situ polymerization polypyrrole (PPy) electrode can achieve repeated healable 5 cycles without extra addition, stretch up to 750 % compared with the original lengths and bend different angles with slight performance decay. This work provides new idea for the synthesis of highly conductive, self-healing and flexible hydrogel electrolyte to promote the development of all-in-one supercapacitor with high specific capacitance for practical applications in flexible and wearable electronics.