Nickel-copper graphene foam prepared by atmospheric pressure chemical vapour deposition for supercapacitor applications

Abstract

This study reports on Ni and NiCu graphene foam prepared by atmospheric pressure chemical vapour deposition. The NiCu foam alloys were prepared using a three-dimensional (3D) scaffold template of polycrystalline nickel foam which is commonly used as a current collector in supercapacitor electrodes. The morphological, composition and structural characterization of as-grown Ni and NiCu graphene foam were carried out using confocal Raman spectroscopy imaging, scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HR-TEM), energy-dispersive X-ray spectrometer (EDS) and X-ray photoelectron spectroscopy (XPS). The results demonstrated that NiCu graphene foam is mainly monolayer and bilayer as compared to Ni graphene foam which is typically a few-layer graphene. The electrochemical performance of Ni and NiCu graphene foam as current collectors were evaluated in a three-electrode electrochemical cell using 1 M NaSO4 aqueous electrolyte and porous activated carbon (AC) produced from lightweight material cork (Quercus suber) as the active electrode material. The AC on NiCu graphene foam current collectors exhibited a high specific capacitance (250–300 F g−1 at 1 A g−1) and good electrochemical stability (94–100% capacitance retention) over 6000 constant charge-discharge cycles at 5 A g−1.