Electrochemical performance of polyaniline-derivated nitrogen-doped carbon nanowires

Abstract

The binder-free all-carbonaceous-component electrode was constructed by directly growing electroactive materials of nitrogen-doped carbon (NDC) on the substrate material of carbon paper (CP). The nitrogen-enriched polyaniline could be converted into NDC nanowires to cover on the surface of CP through electro-polymerization and carbonization processes. The polyaniline-derivated NDC electroactive material exhibits high capacity of 404.0 F g−1 at 1.0 A g−1. The superior capacitance results from the good electron-donor properties of heterocyclic nitrogen distributed in the carbon skeleton and reversible redox reactivity of exocyclic nitrogen-containing functional groups at the edge of carbon skeleton. A low capacity decay of 22% indicates high rate capability when current density increases from 1.0 to 10 A g−1. A high capacity retention ratio of 95.8% after 5000 cycles at 10.0 A g−1 presents good cycling stability. A symmetrical solid-state supercapacitor was constructed using NDC/CP electrode and polyvinyl alcohol-H2SO4 gel electrolyte. The device delivers a specific capacitance of 187.1 F g−1 at 1.0 A g−1, an energy density of 66.54 Wh kg−1 at the power density of 0.8 kW kg−1, the capacity retention ratio of 94.1% after 5000 cycles at 5.0 A g−1 and an output voltage of 1.6 V, which is comparable to the reported state-of-the-art carbon-based supercapacitor. The all-carbonaceous-component electrode presents promising application in electrochemical energy storage devices.