New structural characterization of the LixV2O5 system provided by Raman spectroscopy

The Raman spectra of the is an element of-,delta-, and gamma-LixV2O5 powdered phases are reported. New fingerprints are obtained and discussed in connection with those previously reported for electrochemically and chemically lithiated V2O5. The metastable character of the sigma-phase is explored through the XRD and Raman study of the sigma -> is an element of -> gamma "high temperature" phase transitions and allows explaining the great disparities encountered in the literature spectra. The knowledge of these reference Raman spectra for the LixV2O5 phases constitutes fundamental data for understanding the electrochemical cycling behavior of the Li/V2O5 system.