A film of nickel oxide is anodically deposited on a graphite sheet held in osition on an electrochemical cell during application of a positive electrode voltage to the graphite sheet while exposed to an electrolytic nickel oxide solution within a volumetrically variable chamber of the cell. An angularly orientated x-ray beam is admitted into the cell for transmission through the deposited nickel oxide film in order to obtain structural information while the film is subject to electrochemical and in-situ x-ray spectroscopy from which optimum film thickness, may be determined by comparative analysis for capacitor fabrication purposes.
The present invention relates in general to the selection and testing of materials in association with the production of ultracapacitors or the like. Rights to this invention reside in the United States Government as represented by the Secretary of the Navy and the United States Department of Energy pursuant to Contract No. W-31-109-ENG-38 with the University of Chicago representing Argonne National Laboratory.