Investigation of polyaniline co-doped with Zn2+ and H+ as the electrode material for electrochemical supercapacitors

Polyaniline co-doped with Zn2+ and H+ was synthesized in aqueous HCl solution containing ZnCl2, and tested for its supercapacitive behavior in three-electrode or two-electrode system with 1.0 M H2SO4 as electrolyte by cyclic voltammetry, charge–discharge and electrochemical impedance spectroscopy (EIS). Scanning electron microscopy (SEM) and Fourier transform infrared (FTIR) techniques were employed for characterization of polyaniline co-doped with Zn2+ and H+. Compared with polyaniline doped with H+, it shows a larger specific capacitance of 369 F g−1. Moreover, the specific capacitance remains 90% after 1000 cycles at a current density of 0.5 A g−1, indicating good cycleability.