Bendable graphene/conducting polymer hybrid films for freestanding electrodes with high volumetric capacitances

Bendable freestanding films composed of reduced graphene oxide (RGO) and one dimensional conducting polymers (CPs) including polyaniline (PANI) and polypyrrole (PPy) are successfully fabricated by self-assembly assisted filtration method. The morphology and intrinsic properties of both components are well preserved and the desired synergetic effects are achieved. The intercalated one dimensional CPs act as not only pseudocapacitors to improve the overall capacitances but also an effective framework to open the penetrative channels for the electrolyte. The hybrid freestanding electrodes thus obtained exhibit superior performance in terms of gravimetric capacitance, volumetric capacitance and cycling stability. For example, at the current density of 0.2 A g−1, the RGO/PPy film electrode gives rise to a gravimetric capacitance of 374 F g−1 and a volumetric capacitance of 355 F cm−3; while the RGO/PANI film electrode yields a high gravimetric capacitance of 540 F g−1 and a volumetric capacitance of 616 F cm−3. Both RGO/PANI and RGO/PPy hybrid film electrodes deliver good cycling stabilities with ∼86% of original capacitances being retained after 5000 cycles.