Electrochemical characterization of polyaniline electrode in ammonium citrate containing electrolyte

Polyaniline electrode (PANI) was formed electrochemically at graphite electrode. Electrochemical polymerization was performed at constant current density of 2.0 mA cm−2 from aqueous solution of 1.0 mol dm−3 HCl with addition of 0.25 mol dm−3 aniline monomer. Electrochemical characterization of the PANI electrode in chloride and chloride/citrate electrolyte was performed using cyclic voltammetry and galvanostatic measurement in order to study the influence of citrate ions on charge/discharge capability and cycling efficiency. It was observed that, for anodic potential 0.32 V, higher electrode capacity of PANI electrode in chloride/citrate electrolyte was obtained, comparing to chloride electrolyte, indicating positive effect of citrate ions on cycling characteristics. On the other hand, for higher anodic potential limit of 0.50 V, faster decrease of the electrode capacity in chloride/citrate electrolyte was observed. It was suggested that influence of both chloride and citrate anions had exhibited influence on electrochemical behavior of PANI electrode in citrate containing electrolyte.