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Abstract: This paper studies the synthesis and electrochemical characterization of novel graphene-beaded carbon nanofibers (G/CNFs) as electrode material for use in supercapacitor. The porous G/CNF films were prepared by electrospinning polyacrylonitrile (PAN)/N,N-dimethylformamide (DMF) solution dispersed with oxidized graphene nanosheets, followed by carbonization at 800 °C in a tubular quartz furnace. The morphology and chemical structure of the porous G/CNF films were characterized by means of scanning electron microscopy (SEM), transmission electron microscopy (TEM), and Raman spectroscopy. The electrochemical behavior of the synthesized G/CNF films as supercapacitor electrodes was characterized by means of cyclic voltammetry (CV), galvanotactic charge/discharge, and electrochemical impedance test in a 6 m KOH aqueous electrolyte. Electrochemical measurements revealed that the maximum specific capacitance of the porous G/CNF electrodes reached up to 263.7 F g− 1 at a discharge current density 100 mA g− 1. Furthermore, the supercapacitor exhibited very good cycling stability of energy storage with the retention ratio of 86.9% after 2000 cycles. The high electrochemical performance of the G/CNF electrodes was attributed to the unique nanostructural configuration, high electrical conductivity, and large specific surface area of the graphene nanosheets. [Copyright &y& Elsevier]

This letter reports the fabrication and electrochemical properties of electrospun carbon nanofibers surface-grafted with vapor-grown carbon nanotubes (CNTs) as hierarchical electrodes for supercapacitors. The specific capacitance of the fabricated electrodes was measured up to 185 F/g at the low discharge current density of 625 mA/g; a decrease of 38% was detected at the high discharge current density of 2.5 A/g. The morphology and microstructure of the electrodes were examined by electron microscopy, and the unique connectivity of the hybrid nanomaterials was responsible for the high specific capacitance and low intrinsic contact electric resistance of the hierarchical electrodes. [ABSTRACT FROM AUTHOR]