Single-step growth of pyramidally textured NiO nanostructures with improved supercapacitive properties

Here, we report the fabrication of one step NiO nanopyramid thin film as a binder-free electrode with improved electrochemical properties using a reactive magnetron sputtering. The crystalline nature, surface morphology and chemical composition of the as deposited NiO thin films were analyzed by X-ray diffraction (XRD), Raman spectroscopy, Field emission scanning electron microscopy (FE-SEM), Atomic force microscopy (AFM) and X-ray Photoluminescence spectroscopy (XPS). The electrochemical measurements were carried out using cyclic voltammetry, electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge (GCD) techniques. NiO nanopyramid nanostructures electrode exhibited high specific capacitance (325 F g−1 at 0.4 mA cm−2 in 1 M KOH), high efficient density (19.66 Wh kg−1) and power density (2.15 kW kg−1) with excellent cycling stability (91.4% retention after 1000 cycles).