Electrochemical grown cobalt hydroxide three-dimensional nanostructures on Ni foam as high performance supercapacitor electrode material

Abstract

A macro-porous 3D nanostructure of beta phase of cobalt hydroxide is successfully electrodeposited on nickel foam from 0.005 M cobalt nitrate aqueous bath at constant current (CC) mode without adding any additive. Microstructure, crystal phase and surface morphology of the deposited cobalt hydroxide on Ni foam are physically determined through X-ray diffraction (XRD) analysis and field-emission scanning electron (FE-SEM) microscopy. The results indicate that a pure β-Co(OH)2 phase with interconnected 3D network structure has been fabricated. Application of the fabricated β-Co(OH)2/Ni foam as supercapacitor electrode is studied using electrochemical tests of cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy. A specific capacitance and cycle life of 987 F g−1 and 94.4% were observed for the fabricated electrode. The obtained data confirmed excellent electrochemical performance of the cobalt hydroxide nanostructure deposited onto Ni foam.