Uniform generation of NiCo2S4 with 3D honeycomb-like network structure on carbon cloth as advanced electrode materials for flexible supercapacitors

J Colloid Interface Sci. 2019 Nov 15:556:743-752. doi: 10.1016/j.jcis.2019.08.094. Epub 2019 Aug 26.

Abstract

Direct generation of active materials on carbon cloth (CC) is regarded as an efficient and convenient means to obtain flexible electrodes with high supercapacitor performance. However, uniform generation of active materials on the both sides of CC remains a great challenge. Herein, a facile hanging-hydrothermal method was used to directly generate uniform NiCo2S4 nanosheet arrays on carbon cloth (NiCo2S4/CC), which was then utilized as the positive electrode for flexible supercapacitors. Taking advantage of the unique and uniform honeycomb-like structure of NiCo2S4 nanosheets, the obtained NiCo2S4/CC electrode can deliver an excellent specific capacitance (1638 F g-1 at 1 A g-1), which is significantly higher than NiCo2O4/CC electrode (657.4 F g-1 at 1 A g-1). A two-electrode flexible supercapacitor was assembled using NiCo2S4/CC as positive electrode and carbon cloth coated with activated carbon as negative electrode and revealed a high energy density of 25.2 Wh kg-1 at a power density of 799.6 W kg-1, highlighting its great potential for flexible supercapacitor applications.

Keywords: Carbon cloth; Flexible supercapacitor; Hanging-hydrothermal method; NiCo(2)S(4) nanosheet arrays.