An Electrochemical Cell for Study by XPS of Lithium Intercalation in Oxide Films

Abstract: X-ray photoelectron spectroscopy (XPS) is used to determine valence states of thin films. When used to elucidate the effects of electrochemical intercalation of ions in oxide films, the information required is the valence state of multivalence ions. To ensure that this information is not compromised by surface reoxidation, we have developed an in situ electrochemical cell for use with aprotic and anhydrous electrolytes. This cell has been used to study lithium intercalation in thin oxide layers built up on induim tin oxide (ITO)-coated glass slides. Samples can be exposed for intercalation of lithium (or deintercalation), rinsed, dried and transferred within the vacuum of the spectrometer for characterization. The cell is designed to be withdrawn into a nacelle when not in use so as not to interfere with the normal use of the spectrometer. We have shown that the lithium electrode remains in good condition throughout storage periods. The successful use of the prototype cell gives an opportunity to develop the cell for related electrochemical studies in non-aqueous electrolytes. Copyright (C) 2002 John Wiley Sons, Ltd