Effect of the Doping Anion Replacement on the Polyaniline Electrochemical Behavior

Abstract

Samples of polyaniline synthesized from aniline sulfate were electrochemically cycled in LiCl, LiClO₄, and lithium tetracyanoquinodimethane, with the electrolyte replacement. In all studied cases, the polyaniline is shown to retain its electrochemical activity upon the electrolyte and doping anion replacement. The electrochemical activity with the Cl^– and \({\text{ClO}}_{4}^{ - },\) dopants is reduced in the first cycles upon the electrolyte replacement; however, in the subsequent cycles the reduction decreased. When the electrode under testing has been returned to the native electrolyte, its electrochemical activity and electrochemical capacitance increased, recovering their initial values. When polyaniline has been doped with the tetracyanoquinodimethane anion, each next cycling series revealed an increase in its electrochemical activity, which manifests itself in the cyclic voltammogram area, as well as increase in the electrochemical capacitance from one cycling series to the next one.