Polyaniline-Modified\nOriented Graphene Hydrogel Film as the Free-Standing Electrode for\nFlexible Solid-State Supercapacitors

Abstract

In\nthis study, we report polyaniline (PANI)-modified oriented graphene\nhydrogel (OGH) films as the free-standing electrode for flexible solid-state\nsupercapacitors (SCs). The OGH films are prepared by a facile filtration\nmethod using chemically converted graphene sheets and then introduced\nto PANI on the surface of OGH films by in situ chemical polymerization.\nThe PANI-modified OGH films possess high flexibility, high electrical\nconductivity, and mechanical robustness. The flexible solid-state\nSCs based on the PANI-modified OGH films exhibit a specific capacitance\nof 530 F/g, keeping 80% of its original value up to 10 000\ncharge–discharge cycles at the current density of 10 A/g. Remarkably,\nthe flexible solid-state SCs maintain ∼100% capacitance retention\nbent at 180° for 250 cycles. Moreover, the flexible solid-state\nSCs are further demonstrated to be able to light up a red-light-emitting\ndiode. These results indicate that the flexible solid-state SCs based\non PANI-modified OGH films as the free-standing electrode have potential\napplications as energy-storage devices.