Energy and Power of Supercapacitor Using Carbon Electrode Deposited with Nanoparticles Nickel Oxide

Highly porous activated carbon monoliths (ACMs) supercapacitor electrodes (specific surface area ~1660 m2g-1) were prepared from KOH-treated pre-carbonized biomass fibers by carbonization (N2) and activation (CO2) methods. Nickel oxide nanoparticles were deposited on the surface of the ACMs electrodes for different durations (15, 30, 45, 60 min). The electrodes were characterized by field emission scanning electron microscopy (FESEM), energy dispersive X-ray analysis (EDX), X-ray diffraction (XRD) and N2 adsorption-desorption isotherm techniques. Results from electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV) and galvanostatic charge discharge (GCD) techniques demonstrate that the optimum dipping time range from 15 to 45 min can increase the specific capacitance (Csp) by 30-33 % (138-141 F g-1) with respect to the bare electrode. Correspondingly, the composite electrode with deposition time of 15 min offers the maximum improvement of 39 % in maximum specific energy (4.30 Wh kg-1), but maintaining higher maximum specific power (183 W kg-1).