STUDY OF THIN-FILMS OF NAXC60 - ELECTROCHEMICAL INTERCALATION AND PHYSICAL-PROPERTIES

Electrochemical intercalation of Na into C-60 has been carried out in all solid-state cells in order to probe the phase diagram from the pot ential-composition curve. Experiments are performed in potentiodynamic mode on thin films deposited on Na-beta Al2O3 pellets at 350 K. Inter calation becomes noticeable below 1.305(5) V versus Na+-Na-0 and evide nce is given for a large two-phase domain characterized by an equilibr ium voltage plateau at 1.190(5) V, a smaller intercalation event near 0.95(5) V, and a solid solution domain at about 0.15<V<0.35 V. Na+ dif fusion coefficients have been determined and films have been character ized by X-ray diffraction and Raman spectroscopy.