Morphology-dependent electrochemical performances of nickel hydroxide nanostructures

摘要

Electrochemical capacitors form part of the developing technologies in the field of alternative energy sources. In the present work, nickel hydroxide (Ni(OH)2) 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 417 Fg~(-1) at a scan rate of 5 mV s~(-1) for Ni(OH)2 nanosheets and microflowers, respectively. The higher specific capacitances for Ni(OH)2 microflowers could be attributed to the higher specific surface area, morphology, electronic conductivity and porosity. Both Ni(OH)2 nanostructures exhibited good capacitance retention for 1500 cycles.