Abstract
Recent study on supercapacitor electrodes focuses on metal oxide/nitride which shows high pseudo-capacitance. Titanium oxide (TiO2) has a potential to be a candidate, because of low production cost, nontoxicity and well electrochemical activity on surfaces. However, most metal oxide are made in powder form, mixing with binder as an electrode, which decreases in conductivity and ionic accessibility of electrode. In this study, carbon nanotubes (CNTs) are introduced to improve above problems. First, nitric acidized CNTs are electrophoretically deposited on nickel mesh and TiO2 is coated onto CNTs following via atomic layer deposition(ALD). The laminar structures(Ni/CNT/TiO2) are characterized by X-ray diffraction (XRD), Raman measurement, Energy dispersive spectrometer(EDS), field emission scanning electron microscopy (FE-SEM) and transition electron microscopy (TEM) . The electrochemical properties of electrode, including capacitance, rate capability, and charge-discharge cycle, are studied by cyclic voltammetry (CV) in Autolab. Result demonstrate that mesoporous structure of carbon nanotubes provide conductive network for charge transport. Specific capacitance reaches 564 F/g and 432 F/g in alkaline solution at scan rate of 10 mV/s for grown using 50 and 100 cycles ALD, respectively.