Hydrothermally synthesised nickel oxide nanostructures on nickel foam and nickel foil for supercapacitor application

Abstract

Nickle-based oxides exhibit seamless redox activity and show undisputed parameter optimization flexibility, which makes them a candidate of choice for various scientific analysis and multipurpose execution. The communique addresses the domain of energy storage of hydrothermally fabricated nickel oxide nanostructures by analysing the capacitive behaviour of the sample. The crystal geometry, chemical composition and bonding state of the material were carried out through XRD and XPS analysis, respectively. Electron microscopy showed systematically aligned nano-needles, which in aggregate represent an urchin. A comparative study of specific capacitance (Cs) at a scan rate of 1 mVs−1 showed an enhanced Cs of nickel oxide embedded Ni-foam (1125 Fg-1) against nickel oxide deposited Ni-foil (454 Fg-1). At a current density of 8 mAcm −2, the nickel oxide based Ni-foam electrode exhibited an energy density of 23 Whkg−1 and a power density of 259 Wkg-1 which makes it instrumental in electrochemical devices. The Ni-foam electrode also showed less ‘cycle fatigue’ as its charge/discharge stability dipped by just 12% even after 5000 cycles. The novel supercapacitor electrode developed in this study exhibits excellent specific capacitance, high stability, high power density, and low impedance, demonstrating its promising practical functionality.