Stretchable all-solid-state supercapacitors based on highly conductive polypyrrole-coated graphene foam

Flexible and stretchable all-solid-state supercapacitors are of considerable interest as promising energy storage devices for wearable electronics. Although considerable effort has been devoted to investigate flexible and stretchable supercapacitors, challenges remain in developing supercapacitors with the combination of flexibility, high stretchability and excellent electrochemical performance. In this study, we fabricate highly stretchable electrodes based on a graphene foam/polypyrrole composite through the chemical vapor deposition method and chemical interfacial polymerization method. Because the tensile strain applied to the polypyrrole network is shared by the structural deformation of the graphene foam, the graphene/polypyrrole composite can effectively accommodate the stretching deformation without a significant decay in conductivity. Benefiting from these superior features, an all-solid-state supercapacitor assembled with graphene/polypyrrole compact film electrodes shows a high areal specific capacitance of 258 mF cm−2, energy density of 22.9 μWh cm−2 at a power density of 0.56 mW cm−2 and excellent flexibility (180°) and stretchability (50% strain).