Preparation and electrochemical performance of cellular structure Ni(OH)2 thin film

• Ni(OH)2 thin film with multilayer cellular structure was obtained.
• Stable three-dimension pores facilitated electrolyte to permeate into thin film.
• Ni(OH)2 thin film capacitor shows better reversibility and stability.

Cellular structure Nickel Hydroxide Ni(OH)2 thin film grown on indium-tin oxide (ITO) substrate was synthesized by a two-step hydrothermal method. The crystal structure and morphology of Ni(OH)2 thin film was investigated by means of X-ray diffraction (XRD) and scanning electron microscopy (SEM), respectively. The electrochemical performance was investigated by a cyclic voltammetry (CV) method. The results indicated that the thin film consisted of plate-like β-Ni(OH)2 grains growing on the substrate vertically and connecting each other to form a kind of multilayer cellular structure, which formed a large number of stable three-dimension pores and facilitated electrolyte diffusion and penetration to the inside of thin film. Thus, the specific capacitance of Ni(OH)2 thin film capacitor was 980 F/g at a low scan rate of 10 mV/s; and the better reversibility and stability indicated that the cellular structure Ni(OH)2 thin film should be a kind of promising capacitor electrode material.