Preparation of dendritic nanoporous Ni-NiO foam by electrochemical dealloying for use in high-performance supercapacitors

Abstract

This paper compared the applicability of nickel-copper and nickel-nickel oxide metallic foams as current collectors for supercapacitor. A comprehensive characterization of foams was presented and includes the analysis of their structural, chemical, and electrochemical properties. Several techniques such as structural characteristics and electrochemical methods were used to examine the surface morphology and surface chemical composition of these materials. The process was studied under well-defined experimental conditions using cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and galvanostatic charge and discharge (GCD). The outcome of these experiments demonstrated that the Ni-NiO foam had a higher specific capacitance than Ni-Cu foam. The best specific capacitance for Ni-NiO foam was calculated to be 924 F/g at 1 A/g, which was higher than that obtained for Ni-Cu foam (536 F/g at 1 A/g). Ni-NiO foam maintained 81.8% of its specific capacitance at a current density of 20 A/g and after 3000 cycles, without significant loss of supercapacitor activity.