Porous NiCoS nanosheets decorated activated carbon cloth for flexible asymmetric supercapacitors

Abstract

Flexible electrodes with advantageous architectures have emerged as an urgent necessity. Herein, we demonstrate a novel approach to designing and fabricating porous nickel cobalt sulfide sheets anchored on thermally activated carbon cloth (NiCoS/ACC) for use as a flexible anode in supercapacitors. The thermally activated carbon cloth with functional groups provides a framework for the growth of the nickel cobalt aluminum layered double hydroxide (NiCoAl LDH) precursor, which provides an excellent rate of utilization for the active material. Through hydrothermal sulfuration, NiCoAl LDH precursor can be transformed into porous NiCoS nanosheets, yielding NiCoS/ACC, which shows excellent electrochemical performance in a three-electrode system. Excellent electrical conductivity and the enriched redox-active site provided by ACC together with the high porosity, abundant active sites, and large electrode-electrolyte contact area provided by thin NiCoS nanosheets are believed to account for the enhanced electrochemical properties. Moreover, the flexible supercapacitor can exhibit high energy density and excellent cycling stability when equipped with a NiCoS/ACC positive electrode and an activated carbon cloth negative electrode.