Characterization and electrochemical properties of Cx(VOF3)F as positive material for primary lithium batteries

Vanadium oxide fluoride-graphite intercalation compounds, i.e. Cx(VOF3)F with 17.2 ≤ × ≤ 38.8, have been prepared from V2O5 and graphite in a fluorine atmosphere at 130°C. The structural characteristics of these compounds have been deduced from X-ray diffraction and X-ray photoelectron spectroscopy measurements. Intercalation of VOF3 and fluorine was pointed out. The electrochemical insertion of lithium into C17.7(VOF3)F was investigated by chronopotentiometry and a.c. impedence spectroscopy in propylene carbonate-1 M LiClO4. The chemical diffusion coefficient, DLi, was estimated to be close to 4.0 × 10−10cm2s−1 for all the values of the intercalation ratio of lithium under study (0 < y < 1.5).