Spray pyrolyzed thorn-like nanostructured nickel oxide electrodes for symmetric supercapacitor device

Nickel oxide (NiO) is an appealing electrode for the supercapacitor consequent to its giant capacity, good cyclic stability, and economical feature. Here, we find the significant capacity elevation of nickel oxide thin film electrodes at 350 °C temperature during the variation of precursor concentration. XRD patterns of all electrodes show a face-centered cubic crystal structure. The prepared NiO electrodes are specified by utilizing different characterization techniques, i.e., wettability study, FESEM, TEM, and XPS. It is found that the concentration of the precursor performs a prominent role in increasing the specific capacitance of the electrode. As concentration increases, the specific capacitance increases till a certain value of concentration and then decreases accordingly. The highest value of the specific capacitance is 838.14 Fg−1 at a scan rate of 0.002 Vs−1 obtained for the 0.6 M (NC-3) electrode. The optimized electrode shows 82% retention even after 5000 cyclic voltammetric cycles. The optimized electrodes’ specific power and specific energy at 0.001 Acm−2 are 400.00 Whkg−1 and 9.41 kwkg−1, respectively. Electrochemical characterizations of the fabricated NiO symmetric device are also studied.