Synthesizing a flower-like NiO and ZnO composite for supercapacitor applications

Abstract

In order to enhance the electrochemical properties of single NiO, we have sought a simple way to synthesize a NiO and ZnO composite and make the composite a pseudocapacitors electrode material. We used a hydrothermal method to generate the composite on the surface of nickel foam, regarding it as the major subject in this experiment. To study the electrochemical performance of this composite, we adopted measurements including cyclic voltammetry, galvanostatic charge–discharge and electrochemical impedance spectroscopy measurements. We prepared samples for 2, 4, 6 and 8 h and compared the electrochemical properties of these different samples, respectively. We found that the as-synthesized NiO and ZnO composite was obtained at 8 h, and the maximum capacitance can reach 1.42 F cm−2 (10 mA cm−2). In addition, the composite also showed good cycle stability and displayed a capacitance of 63.9% after 1000 cycles tested in 6.0 M KOH solution. Thus, it was determined that the composite can offer a great potential for obtaining a supercapacitor electrode material with excellent performance. The experiment can, to some extent, provide a way in which the low electrochemical performance of single oxides can be improved by synthesizing double-oxide electrode material.