Electrochemical behavior of carbon-nanotube/cobalt oxyhydroxide nanoflake multilayer films

A new type of multilayer films consisting of multi-walled carbon nanotubes (MWCNTs) and cobalt oxyhydroxide nanoflakes (CoOOHNFs) are developed by alternately electrostatic self-assembly and electrodeposition technique, respectively. The successful growth of multilayer films composed of MWCNT and CoOOHNF are confirmed by scanning electron microscopy and X-ray photoelectron spectra. The multilayer film electrode is investigated for use in a supercapacitor with cyclic voltammograms and galvanostatic charge-discharge experiments. Experimental studies reveal that coatings of MWCNT/CoOOHNF on ITO glass present excellent electrochemical capacitance with specific capacitance being 389 F g−1. The overall improved electrochemical behavior is accounted for the unique structure design in the multilayer films in terms of effective micro-porous nanostructure, large specific surface-area and good electrical conductance.