Improved electrochemical performance of free standing electrospun graphene incorporated carbon nanofibers for supercapacitor

Abstract

In this paper, we report the fabrication of carbon nanofibers (CNFs) by electrospinning of polyacrylonitrile (PAN) solution in N,N-dimethylformamide (DMF)with different concentrations followed by stabilization and carbonization in a tubular quartz furnace. To improve the electrochemical performance, graphene nanosheets have been used to prepare porous graphene/carbon nanofibers (G-CNFs). The morphology of the porous G-CNFs were characterized by means of scanning electron microscopy (SEM). Diameter of CNFs and G-CNFs were found to be in the range of 400 – 500 nm reveals the fibers in nanoscale with high porosity. The electrochemical performance of as-synthesized CNFs and G-CNFs was studied by cyclic voltammetry (CV), galvanostatic charge discharge (GCD) and electrochemical impedance spectroscopy. The CV curve of the pure CNFs show distorted rectangular shape whereas CV curve of G-CNFs exhibit a nearly rectangle-shaped profile which is the characteristic of an ideal electric double-layer capacitor. The improved electrochemical performance of G-CNFs is due to the improved internal electrical conductivity of G-CNFs via graphene nanosheets interlaying.