Reduced graphene oxide-silver nanoparticles/nitrogen-doped carbon nanofiber composites with meso-microporous structure for high-performance symmetric supercapacitor application

Abstract

The electrochemical performance of carbon nanofibers (CNFs) as the electrode material of the supercapacitor should be improved to meet requirements of renewable energy systems. We report here the synthesis of nitrogen-doped carbon nanofibers (RGO-AgNP/N-CNF) with a meso-microporous structure by the supplement of reduced graphene oxide–silver nanoparticles (RGO-AgNPs) into N-CNFs. The usage of polyacrylonitrile (PAN) is aimed to supply nitrogen doped in carbon bulk, which can enhance fast migration of electrolyte ions during the electrochemical process. Decoration of AgNPs on RGO surface improves electrical conductivity of RGO-AgNP/N-CNF composites and alleviates the aggregation of AgNPs. The addition of RGO-AgNPs elevates the specific surface area and mesoporous content of CNFs. The assembled RGO-AgNP/N-CNF symmetric supercapacitor possesses high specific capacitance of 188.0 F g−1 at a current density of 0.5 A g−1, delivers an ultrahigh energy density of 26.1 Wh kg−1 and displays an excellent cycling performance (97.5% retention after 5000 cycles), which suggest its big potential as energy storage devices.