Ion transport in poly(3,4-ethylenedioxythiophene)-poly(styrene-4-sulfonate) composites

The ion transport properties and electrochemistry of both chemically prepared and electrochemically prepared poly(3,4-ethylenedioxythiophene)-poly(styrene-4-sulfonate) composites have been investigated by cyclic voltammetry and impedance spectroscopy in a variety of electrolyte solutions. The polymers exhibited facile electrochemistry, fast ion transport, and good electrochemical stability. The ionic conductivities of the polymers are strongly dependent on the concentration and conductivity of the electrolyte solution used. At low electrolyte concentrations, the ionic conductivities of these polymers also show some potential dependence. Ion transport in chemically prepared layers was found to be much faster than in electrochemically prepared films. The high ionic conductivities of the polymers are shown to be due to their very porous structure and electrolytes in pores.