Co-Fe layered double hydroxides nanosheets vertically grown on carbon fiber cloth for electrochemical capacitors

We demonstrate the fabrication of a core-shell structure composite of Co-Fe layered double hydroxides (LDHs) on the surface of carbon fiber cloth (CFC). The Co-Fe LDHs nanoplates are vertically anchored onto the surface of electrical conductive CFC via a simple hydrothermal process followed by an I-2 oxidation process. The hexagonal Co-Fe LDHs nanoplates on the surfaces of carbon fibers form a porous network film. The carbon fibers with high conductivity can act as conductive cores to support a large number of Co-Fe LDHs nanoplates to deliver a high specific capacitance of 774 F g(-1) at the current density of 1 A g(-1). An assembled asymmetric capacitor by using Co-Fe LDHs-CFC as positive electrode material and activated carbon as negative electrode material can deliver an energy density of 16.1 Wh kg(-1) at the power density of 399.7 W kg(-1) with a good cycling stability. This study provides a way to combine CoeFe LDHs with carbon materials to obtain a composite that can deliver an improved performance for electrochemical capacitor application. (C) 2016 Elsevier B.V. All rights reserved.