An interface-integrated hydrogel for all-in-one flexible supercapacitor with excellent wide-temperature and self-healing properties

With the rapid development of flexible energy storage devices, the abilities to withstand various of mechanical deformation and maintain stable electrochemical performance at different temperatures are two decisive factors that stand out in their applications. Herein, aniline containing 2-acrylamido-2methylpropane sulfonic acid sodium is polymerized in-situ on hydrogels with double cross-linked networks constructed by polyacrylamide, polyvinyl alcohol and quaternary ammonium salt of chitosan through electrostatic interaction, so as to obtain the PPHP-Na hydrogels for the construction of the all-in-one flexible supercapacitors. The PPHP-Na hydrogels can withstand a maximum of 544% tensile strain at tensile stress up to 601 kPa, and can maintain stable dissipation during stress-strain tensile cycles and recover quickly after cycling, exhibiting excellent mechanical properties. In addition, the optimal PPHP-Na hydrogel shows a high ionic conductivity of 65.6 mS cm-1. More importantly, as an all-in-one flexible energy storage device, the PPHP-Na supercapacitor shows high area capacitance of 250.75 mF cm-2, and can maintain relatively stable electrochemical performance at -40-80 degrees C and good self-healing property. This interface-integrated strategy of all-in-one flexible supercapacitors with excellent and stable electrochemical performance constructed provides meaningful ideas for the development of flexible electronic devices.