Morphology-dependent electrochemical performances of nickel hydroxide nanostructures

Abstract

Electrochemical capacitors form part of the developing technologies in the field of alternative energy sources. In the present work, nickel hydroxide (Ni(OH) <inf>2</inf>) nanosheets and microflowers are hydrothermally prepared employing different chemical precursors. Structure, morphology and chemical analysis are conducted using powder X-ray diffraction, field emission scanning electron microscopy and energy-dispersive X-ray spectroscopy measurements. Electrochemical performances as supercapacitor electrodes of the synthesized nanostructures are evaluated through cyclic voltammetry and galvanostatic charge–discharge measurements with three-electrode configurations. The results indicated the specific capacitance of 180 and 417Fg-1 at a scan rate of 5mVs-1 for Ni(OH) <inf>2</inf> nanosheets and microflowers, respectively. The higher specific capacitances for Ni(OH) <inf>2</inf> microflowers could be attributed to the higher specific surface area, morphology, electronic conductivity and porosity. Both Ni(OH) <inf>2</inf> nanostructures exhibited good capacitance retention for 1500 cycles. © 2019, Indian Academy of Sciences.