X-RAY-DIFFRACTION AND X-RAY ABSORPTION STUDIES OF THE STRUCTURAL MODIFICATIONS INDUCED BY ELECTROCHEMICAL LITHIUM INTERCALATION INTO V2O5

XRD and XRA analysis were performed on electroformed LixV2O5 bronzes in order to follow structural evolutions in the V2O5 host lattice along with the occurence of the lithium intercalation. In situ XRD analysis has shown a splitting of the LixV2O5 diffraction peaks in the -0.3 to 0.4 Li per V2O5-insertion range which correlates well with a splitting of the electrochemical process itself. According to the present XRD data, no crystallized phase, besides LiV2O5, is generated when electroreduction proceeds from 1 to 2 Li per V2O5 but a loss of the long range order occurs for the highest lithium contents (2 li per V2O5). Preliminary XRA analysis has shown the appearance of local disorders around the vanadium atom as the electroreduction proceeds: firstly modifications of the VV correlations when electroreduction is performed until 0.9 electron per mole of V2O5 and thereafter modifications of the VO correlations for the deepest electroreduction (≈2.4 electron per mole of V2O5). © 1990.