Fabrication of nickel-based composite film electrode for supercapacitors by a new method of anodization/GCD

Abstract

Anickel-based composite filmwas fabricated on Ni foil, by two-electrode anodization and galvanostatic charge-discharge (GCD) treatment. The surface morphology, states of chemical species, and crystal structure of the filmwere characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and X-ray diffraction (XRD). The electrochemical performance was tested using an electrochemical workstation and battery program-control test system. The test results indicated that the filmpossessed a nanoflower-like morphology, and consisted of NiO, α-Ni(OH)2 and β-Ni(OH)2. The NiO-α-Ni(OH)2-β-Ni(OH)2 compounds exhibiting a high specific capacitance, superior rate capability, and good cyclability (1509 F·g-1 at 6.7A·g-1, 1120 F·g-1 at 66.7 A·g-1, after 2000 cycles, the capacitance of the filmremained unchanged).