Electrochemical characterization of a carbon nanofiber electrode system hybridized with PEDOT-PSS

In this work, electrochemical properties of a bilayer electrode system prepared from an electrically conducting polymer, poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate), PEDOT-PSS coated carbon nanofibers (CNFs), have been investigated. The CNFs were used as supports for the deposition of PEDOT-PSS by a dip-coating technique to yield a bilayer electrode system. Electrodes prepared by such a method were used in supercapacitors operating in acidic (1 M H2SO4) electrolytes. The capacitance values were estimated by voltammetry and galvanostatic techniques with a three-electrode cell configuration. Due to the CNF's graphitic structure and the presence of exterior walls with numerous edges, a high specific surface area and easily accessible electrode/electrolyte interface were obtained, thus yielding good capacitance in the bilayer active materials. The capacitance for PEDOT-PSS coated CNF bilayer electrodes ranged from 80 to 180 F/g and the fabricated materials showed good cycling performance with high stability in aqueous electrolytes. This was probably due to enhanced access to the CNFs, leading to the generation of a double layer and, ultimately, higher values of the capacitance.