Facile fabrication of flower-like CuCo2S4 on Ni foam for supercapacitor application

Abstract

Electrochemical performance and production cost are the main concerns of electrode materials for the practical supercapacitor applications. Here we use a simple and universally applicable two-step hydrothermal treatment process to prepare the flower-like CuCo2S4 nanosheet arrays directly grown on Ni foam and employ it as binder-free and conductive-agent-free electrode for pseudocapacitors. The electrode at a current density of 5 mA cm−2 exhibits an ultrahigh capacitance of 908.9 F g−1 and at 30 mA cm−2 delivers an outstanding cycling stability with retaining 91.1% after 2000 cycles compared with its initial capacity. Furthermore, the assembled flower-like nanostructured CuCo2S4//active carbon asymmetric supercapacitor displays a specific capacitance of 93.5 F g−1 at 1 mA cm−2, an energy density of 29.2 Wh kg−1 at 127 W kg−1, as well as 126.39% capacitance retention through 2000 cycles at the high current density of 25 mA cm−2, suggesting the flower-like CuCo2S4 nanosheet arrays hold promise for practical application of high-performance supercapacitors.