Surfactant-assisted synthesis of plate-like CuS particles for high-performance symmetric capacitor

Abstract

In this research, plate-like CuS particles were synthesized through a hydrothermal method using cetyltrimethylammonium bromide (CTAB) and polyvinylpyrrolidone (PVP) as surfactants. The effects of surfactant type and content on the structural, microstructural, and electrochemical properties were explored by the various characterization techniques. Single-phase CuS powders with a space group of P63/mmc were crystallized by decomposition of the copper-thioacetamide complex during hydrothermal treatment. The spherical morphology transformed into plate-like particles by adding the CTAB surfactant, while the PVP surfactant led to an agglomeration of small spherical nanoparticles. With adding the CTAB surfactant, the specific capacitance increased from 630 to 1806 Fg−1 at a current density of 1 Ag−1, while it increased up to 1575 Fg−1 for the PVP surfactant. A symmetric capacitor was assembled on the base of spherical CuS nanoparticles as the negative electrode and the platelike CuS particles as the positive electrode. The CuS//CuS capacitor exhibited comparable electrochemical performance including an energy density of 25.62 Whkg−1 and a power density of 1488 Wkg−1, respectively.