One-pot synthesis of nickel oxide–carbon composite microspheres on nickel foam for supercapacitors

Using glucose and Ni(NO3)2 as precursors, the nickel oxide–carbon (NiO–C) composites are directly formed on the nickel foam by a one-pot hydrothermal method. The product presents a spherical morphology with the carbon component in the composite being a non-graphitic phase. The presence of NiO provides additional pseudo-capacitance for the electrode materials and the composites exhibit superior specific capacitance to the pure carbon materials formed on the nickel foam. Apart from that, compared with the nickel sheet substrate, the utilization of the nickel foam benefits for the achievement of higher performance and stability owing to its unique 3D structure. The highest specific capacitance for the NiO–C–nickel foam electrode of 265.3 F g−1 is obtained at a discharge current density of 0.25 A g−1.