Carbon and Nickel Oxide/Carbon Composites as Electrodes for Supercapacitors

The carbon and nickel oxide/carbon composite electrodes were prepared by plasma jet and magnetron sputtering techniques. The investigations were performed to evaluate the influence of the Ar/C2H2 ratio on the specific capacitance values of carbon and NiO/carbon electrodes. The obtained electrodes were investigated by scanning electron microscopy, Raman scattering spectroscopy (RS), and X-ray diffraction techniques. The surface of the carbon electrodes became less porous and more homogenous with increasing Ar/C2H2. The RS results indicated that the fraction of the sp2 carbon sites increased with increasing Ar/C2H2 ratio. The increase of the Ar/C2H2 ratio increased the capacitance values from 0.73 up to 3.6 F/g. Meanwhile, after the deposition of the nickel oxide on the carbon, the capacitance increased ten and more times and varied in the range of 7.6–86.1 F/g.