Designing and simulating of NiO@Graphite asymmetric supercapacitor device using thermally optimized nickel oxide electrode

In this manuscript, we have produced nickel oxide thin films by facetious spray pyrolysis method at different deposition temperatures for the supercapacitor application. The impact of physical properties and chemical compositions of the prepared electrodes is also studied in this manuscript. Among all prepared samples, AT-2 (with deposition temperature 375 °C) is found to be the finest electrode for supercapacitor execution with an excellent specific capacitance of 256.52 Fg⁻¹ at 0.002-V scan rate by cyclic voltammetry. The same electrode shows a specific capacitance of 18.60 Fg⁻¹ by GCD analysis and parades an energy density of 36.47 Whkg⁻¹ with a power density of 9.91 Wkg⁻¹ at 0.001-A current density. The synthesized NiO@AT-2 electrode shows 78% and 71% stability in specific capacitance after 5000 CV and GCD cycles, respectively. The advanced specific capacitance of the AT-2 electrode is credited to its greater superficial expanse, the greater quantity of active positions, and inferior charge transfer resistance. Furthermore, the AT-2 nano-granular electrode is further used to fabricate for asymmetric supercapacitor device with a graphite electrode. The fabricated asymmetric device shows a specific capacitance of 61.37 Fg⁻¹ at 0.002-Vs⁻¹ scan rate and parades a higher energy density of 75.30 Whkg⁻¹ with a power density of 1.16 Wkg⁻¹ at 0.02-mA current density.