Charging/discharging behavior of manganese oxide electrodes in aqueous electrolyte prepared by galvanostatic electrodeposition

Energy storage devices with high energy density have been used in many electronic devices in recently years. A supercapacitor is one such device, but lower energy density has limited its applications. In this study, manganese oxide deposited on a titanium substrate at various deposition temperatures using the galvanostatic electrodeposition method as the electrodes of a supercapacitor was investigated. The specific capacitance of a supercapacitor is depended on the deposition temperature and is affected by the surface morphology and roughness of the electrode surface. At a deposition temperature of 15°C, manganese oxide showed a needle-like appearance, a roughness of 60.0 nm, and a maximum specific capacitance of 225.3 Fg^-1. The charging/discharging behavior of a supercapacitor was analyzed in 0.1 M Na ₂SO₄ aqueous electrolyte at various measuring temperatures and operating potential voltage ranges. The supercapacitor achieved a high energy density of 37.70 Whkg^-1 in a 0.1 M Na₂SO ₄ electrolyte at 25°C in an operation range of 0 to 1.3 V.