Electrochemical performance of CuCo<inf>2</inf>O<inf>4</inf>/CuS nanocomposite as a novel electrode material for supercapacitor

Abstract

(1−x) CuCo2O4-xCuS (x = 0, 0.1, 0.25, 0.5) nanocomposite samples were prepared using hydrothermal and thermolysis procedures. The crystal structure and the percentages of phases formed in the nanocomposite samples were studied employing Fullprof software. X-ray photoelectron spectroscopy (XPS) was carried out to identify the different ions present in samples and their oxidation states. The specific capacitance is remarkably enhanced after adding CuS emphasizing the synergistic effect between CuCo2O4 and CuS. The optimum performance of 735 Fg−1 was achieved for 25% CuS. At a higher amount of CuS, the electrochemical activities become less compared with a low CuS amount. The supercapacitor electrode of 0.75CuCo2O4/0.25CuS exhibited high stability with a longer discharging time compared with pristine CuCo2O4 and CuS. Also, it maintained 88.9% of its initial Cs and consequently, this material can work as an excellent supercapacitor electrode. Electrochemical impedance spectroscopy (EIS) analysis was also performed.