Flower-like Ni–Co hydroxides on Ni foam for high-performance supercapacitor applications

Abstract

In this paper, interconnected and flower-like Ni–Co hydroxides on Ni foam (Ni–Co hydroxide/NF) are synthesized through chemical treatment. The synthesis method and structure design enhance the mass loading of the active material (up to 10.10 mg cm⁻²) and its capacity. For the sample Ni–Co hydroxide/NF, the interconnected and porous structure facilitates ion diffusion and charge transfer, maximizes the use of electroactive species and improves the reaction kinetics. Its freestanding structure could anchor and immobilize the Ni–Co hydroxide electrode material on Ni foam to restrict self-aggregation, thus producing an integrated hybrid architecture. Accordingly, the as-prepared Ni–Co hydroxide/NF sample exhibits high electrochemical properties with an areal capacity of 1441.5 μA h cm⁻² at 10 mA cm⁻² and 70.1% capacity retained after 5000 cycles at 25 mA cm⁻².