Preparation and synergistically enhanced supercapacitance properties of MnO2-PANI/Ti foam composite electrodes

MnO₂-PANI/Ti foam composite electrodes were prepared by depositing polyaniline (PANI) and MnO₂ onto the Ti foam through a two-step cyclic voltammetry (CV) method in different monomer solvents. The effects of monomer solvents (water, ethanol, water-ethanol mixture) and test potential window on the electrochemical properties of the composite electrodes were investigated. The capacitance properties of MnO₂-PANI/Ti foam composite electrodes were compared with PANI/Ti foam and MnO₂/Ti foam electrodes. Results show that the sample prepared in water-ethanol mixture exhibits the best performance. The gravimetric capacitance of the active materials in MnO₂-PANI/Ti foam composite electrodes is 945.6 F/g. The areal and volume capacitance values of MnO₂-PANI/Ti foam are up to 97.4 mF/cm² and 1217.5 mF/cm³, respectively. The areal capacitance of MnO₂-PANI/Ti foam is 2.0–3.3 times the sum of PANI/Ti foam and MnO₂/Ti foam. The expanded test potential window can increase the storage capacity and energy density of the samples markedly.