Flower-like binary cobalt-nickel oxide with high performance for supercapacitor electrode via cathodic electrodeposition

Abstract Flower-like cobalt-nickel binary oxide was prepared as electrode materials for supercapacitors via cathodic electrodeposition. The deposition experiments were performed at the constant potential of −1 V on Ni foam substrate without any surfactant and template. Scanning electron microscopy (SEM) images indicate that the flower-like Co3O4 nano-sheet layers are homogeneously distributed on NiO layer with length of about 200 nm. The as-prepared Co3O4-NiO exhibits a specific capacitance of 687.5 F g−1 at the current density of 0.5 A g−1 (vs. Ag/AgCl). Meanwhile, they show excellent rate performance (94% retained from 0.5 A g−1 to 10 A g−1) and outstanding cycle life (92% retained after 2500 cycles). These results indicate that the flower-like cobalt-nickel binary oxide electrode deposited on Ni foam can be considered as a promising candidate for the supercapacitor electrode materials.