LAUSR

Electrode materials play a crucial role in determining the comprehensive performance of the constructed flexible supercapacitors. Herein, a simple synthesis method was reported to fabricate soft polypyrrole (PPy) hydrogels with in situ-doped sulfonated graphene quantum dots (sGQD). The sulfonic acid groups rimming the graphene quantum dots (GQD) can protonate the nitrogen groups of PPy and form electrostatic interactions, leading to PPy chains cross-linking to form a three-dimensional network which can be gelated into a hydrogel. It is found that sGQD can form transport channels to facilitate fast solvated ion diffusion during charge and discharge process that can contribute to the performance improvement. Since both electrochemical activity and excellent conductivity are reserved, the as-prepared PPy/sGQD-160 hydrogel electrode exhibits an extremely higher specific capacitance (641 F g −1 at current density of 0.2 A g −1 ) and superior cycle stability compared with PPy hydrogel. In addition, the electrochemical performance of PPy/sGQD hydrogels is gradually improved with the increment of sGQD, which can be ascribed to the high conductivity of sGQD dopant. These results indicate that the obtained PPy/sGQD hydrogels can be considered as a promising electrode material for flexible high-performance supercapacitors.