Electrochemical and structural properties of radio frequency sputtered cobalt oxide electrodes for thin-film supercapacitors

The electrochemical and structural properties of cobalt oxide films which a re deposited at different sputtering gas-ratios Of O-2/(Ar + O-2) are inves tigated. In order to examine the electrochemical properties of the as-depos ited films, all solid-state thin-film. supercapacitors (TFSCs) are fabricat ed. There Consist Of Co3O4 electrodes and an amorphous LiPON thin-film elec trolyte. It is shown that the capacitance behaviour of the Co3O4/LiPON/Co3O 4 TFSCs is similar to bulk-type supercapacitor behaviour. It is further sho wn that the electrochemical behaviour of the TFSCs is dependent on the sput tering gas-ratios. The gas-ratio dependence of the capacitance of the oxide electrode films is discussed based on X-ray diffraction (XRD) and electric al results for the Co3O4 films. (C) 2001 Published by Elsevier Science B.V.