Hydrothermal synthesis of NiO/NiCo2O4 nanomaterials for applications in electrochemical energy storage

It is well known that the intelligent hybridization of active materials and the controllable recombination of nanostructures can significantly improve the electrochemical performance of pseudocapacitor electrodes. In this work, a NiO/NiCo 2 O 4 needle/sphere nanostructure was synthesized on the hydrochloric acid-activated Nickel foam by a simple hydrothermal method and measured the performance of it as an electrode material for supercapacitors. Field emission scanning electron microscope, transmission electron microscope, X-ray diffraction, and X-ray photoelectron spectroscopy were used to characterize the morphology and composition of the samples. The electrodes display a prominent specific capacitance (2447 F/g at the ampere density of 2 A/g) and remarkable cycling stability (85.2% capacity remained after 3000 cycles), owing to the unique needle/sphere composite architecture and the rational combination of active materials. The results demonstrate that the three-dimensional composite structure of NiO/NiCo 2 O 4 nanomaterials provides a large specific surface area for the electrode, which promotes the penetration of electrolyte ions and the transmission of electrons. This novel structured material will be promising in the application of supercapacitor electrode materials.