Effects of preparation conditions on the supercapacitor performances of MnO2-PANI/titanium foam composite electrodes

Abstract

MnO2-polyaniline (PANI)/titanium foam composite electrodes were prepared by a two-step cyclic voltammetry method with titanium foam as the current collector and aniline and manganese acetate solution as the deposition electrolytes. The effects of monomer concentration, deposition time, and scan rate on the supercapacitor performances of the composite electrodes were studied. The reasons for the change of capacitance were discussed by electrochemical impedance spectroscopy and deposition curves. Results show that nanoscale PANI and MnO2 are uniformly combined in the composite electrode. The redox reversibility and deposition amount of PANI are affected by the concentration and deposition scan rate of aniline. The concentration and deposition scan rate of manganese acetate mainly influence the deposition state of MnO2 and the compactness of the composite film. Under the optimized conditions, the composite electrode has a high capacitance value of 97.38 mF cm−2 (945.44 F g−1) at a current density of 0.2 mA cm−2 and exhibits superior cycling performance.