The ''capacitor'' concept of the current-producing process mechanism in polyaniline-type conducting polymers

The ''capacitor'' conception of a current-producing process in conducting polymers of a polyaniline type has been considered. According to this conception, a current-producing process is bound up with the charge-discharge capacity of the double electric layer. It is abnormally high in the systems under consideration due to the peculiarities of its structure. We suggest theoretical models for a thin polymer film at a micro- and macroscopic levels. The double electric layer capacity has been estimated and the character of galvanostatic and cycling voltammograms has been explained on the basis of these models. In order to prove the validity of the conception, we have conducted special tests in somewhat narrowed potential range. The proposed conception is not in contradiction with the known statement about the formation of cation-radicals in the solid state. At the same time these cation-radicals are formed in charging-discharging double layer capacitor, but not by the electrochemical oxidation-reduction process, because there is no charge transfer through the phase boundary. Copyright (C) 1996 Elsevier Science Ltd