Electrochemical polymerization of polyaniline doped with Cu2+ as the electrode material for electrochemical supercapacitors

Polyaniline doped with Cu2+ (PANI/Cu2+) was synthesized by cyclic voltammetry on the stainless steel mesh with various concentrations of copper sulfate (CuSO4 center dot 5H(2)O) in an electrolyte. The structure and morphology of PANI and PANI/Cu2+ films were characterized by Fourier transform infrared, X-ray diffraction, scanning electron microscopy, energy dispersive X-ray spectroscopy and X-ray photoelectron spectroscopy. The electrochemical properties of PANI and PANI/Cu2+ films were investigated by cyclic voltammetry, galvanostatic charge-discharge testing and electrochemical impedance spectroscopy (EIS) in a 0.5 mol L-1 H2SO4 electrolyte in a three-electrode system. The specific capacitance of the PANI/0.2 M Cu2+ film shows a larger specific capacitance of 618 F g(-1), lower resistance and better stability compared with the pure PANI film, although it is reduced to 340 F g (1) after the first 100 cycles. Thus the good capacitive performance demonstrates its potential superiority for supercapacitors.