Facile synthesis of new nanocomposite based on cobalt oxide and carbon nanotubes with excellent electrochemical capacitive behavior

A new two-step synthesis of composite electrode based on carbon nanotubes (CNTs) and cobalt oxide (Co3O4) by electrophoretic deposition of CNTs on Ni foam followed by electrodeposition of cobalt hydroxide on CNTs electrode and heat treatment to form Co3O4/CNTs composite electrode was developed. The structure and morphology of the electrodes were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Their electrochemical performances were evaluated by cyclic voltammetry (CV), galvanostatic charge-discharge and electrochemical impedance spectroscopy (EIS). Experimental results indicated that the nanocomposite electrodes exhibitd excellent pseudocapacitive behavior. In the potential range of 0.1-0.45 V(vs SCE), the nanocomposite electrode showed a high specific capacitance of 867 F.g(-1) in 6 M KOH electrolyte and a capacity retention of 90% after 1000 cycles at a current density of 1 A.g(-1).