| 초록 |
In this work, the energy storage composite electrodes were prepared by mixing activated carbons (ACs) modified with a nanosize semiconducting oxide TiO2 through a means of ultrasonic vibration in ethanol solution for 30 min. The changes of chemical compositions and structures of the composite electrodes were characterized by X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) measurements, respectively. We examined cyclic voltammetry and ac impedance response of composite electrodes in the aqueous electrolyte. Commercially available activated carbon electrodes were also tested in order to compare their specific capacitance. As a result, it was found that the specific capacitance of the composite electrodes measured in the range of 0-0.8 V was increased from 48 to 70 F/g compared to the only activated carbon electrodes. This was attributed to the reduction of polarization of ACs modified by semiconducting nanosize TiO2. Consequently, the semiconducting TiO2 used was proven to be one of alternative electrode materials instead of RuO2 for electrochemical-double-layer capacitors. |
