Facile synthesis of CuCo2S4 nanoparticles as a faradaic electrode for high performance supercapacitor applications

In this paper, we report the synthesis of spinel CuCo2S4 nanoparticles (NPs) via a one-step hydrothermal method using two kinds of sulfur precursor's thioacetamide-TAA and thiourea-TU separately. The X-ray powder diffraction (XRD) analysis of both samples revealed a cubic phase of spinel CuCo2S4 crystal structure with Fd3m space group. The spherical (19–20 nm) and hexagonal (17–19 nm) shaped NPs were observed by transmission electron microscope (TEM) images. N2 adsorption-desorption results showed the high surface area of TAA-CuCo2S4 (91.03 m2 g-1) than TU-CuCo2S4 (59.82 m2 g-1). XPS spectra exhibited the coexistence of Cu2+ and Cu3+ valence states of spinel cubic CuCo2S4. Electrochemical measurements showed that the TAA based CuCo2S4/Ni foam electrode has high specific capacity (1885 C g−1/523 mA h g−1 at a current density of 2 A g-1 about 5.4 times higher than thiourea based electrodes), ultrahigh capacity retention of 98% after 6000 GCD cycles at high current density of 10 A g-1 and excellent energy density of 41.89 provided with a power density of 318.31 W kg−1. These results suggest that TAA assisted electrode material is suitable for improving electrochemical performance of supercapacitors. •This paper reports the hydrothermal preparation of CuCo2S4 nanoparticles using two different sulfur sources.•They provide a high specific capacity of 523 mAhg−1 at a current density of 2 A g−1 and excellent cyclic stability.•They offer a high energy density of 41.89 W h kg−1 at a power density of 318.31 W kg−1.