Effects of various molarities of nickel oxide on the aggregate 1D–3D structure and its electrochemical activity

Abstract

The effect of concentration on the charge storage of supercapacitors is one of the crucial parameters. In the current work, we have successfully deposited the 1D–3D aggregate structure of the nickel oxide (NiO) with its various content concentration of the nickel nitrate precursor on stainless steel (SS) via the simplest hydrothermal technique. The influence of the molarities of the NiO on the nanostructures as well as electrochemically charge storage applications has been studied. The X-Ray diffraction (XRD), scanning electron microscopy (SEM), and FTIR were used for structural, and morphological analysis of the nickel oxide. Here, we observed the cubic structure with the Fm-3 m space group of NiO nanomaterials. SEM images depict the 1D-columnar flakes along with aggregate 1D–3D morphology. The flakes like NiO nanomaterials exhibit a highly electrochemically charge storage pseudocapacitive nature. The optimized 0.40 M of NiO nanomaterial electrode shows the highest specific capacitance value is 639.3 Fg−1 at 5 mVsec−1 in aqueous 1 M KOH in an aqueous electrolyte. The observed maximum specific energy (SE) and specific power (SP) are 74.13 Whkg−1 and 2.07 KWkg−1. The optimized NiO//reduced Graphene Oxide (rGO) based asymmetric hybrid supercapacitor device (AsHSD) shows an excellent specific capacitance value is 34.8 Fg−1 with the highest charging-discharging capability of 83 % up to 100 cycles.