Nickel hydroxide/polypyrrole composite electrodes were prepared by an electrolytic deposition and their electrochemical behaviors were evaluated by using cyclic voltammetry, electrochemical impedance spectroscopy and galvanostatic chargedischarge cycling techniques. Deposition of composite electrodes were carried out in the potentiostatic mode at -0.85 V versus Ag/AgCl and compared with the nickel hydroxide film electrode. The electrolyte solution for electrodeposition consisted of 0.1M aqueous Ni(NO3)2 (50 mL) and various vol.% of polypyrrole with 0, 0.05, 0.1 and 0.5 ml. The specific capacitance measured at the scan rate of 10 mV s-1 was found to be 1975 (0 ml), 2141 (0.05 ml), 1565 (0.1 ml) and 1171 F g-1 (0.5ml) for deposited weights of 30, 30, 35 and 55 μg cm-2, respectively. The adequate use of polypyrrole improves the dispersion of nickel hydroxide. Therfore, the intercalation and/or absorption of diffusing ions from electrolyte and proton insertion from water may also easily gain access to the available sites reducing the degradation of the electrochemical performance in cyclic redox reactions.

Keywords: Ni(OH)2/polypyrrole composite, Electrodeposition, Pseudo-Capacitor, Electrochemical properties.