Spectroscopic and computational study of structural changes in γ-LiV₂O₅ cathodic material induced by lithium intercalation

International audienceStructure, electronic states, and vibrational dynamics of γ-LiV2O5 were studied by combined use of quantum-chemical calculations and Raman spectroscopy. The spin-polarized DFT+U calculations correctly mimic the structural changes induced by the Li intercalation into the V2O5 framework. The analysis of the density of electronic states shows that the electrons of Li atoms are transferred to the Vb atoms and are aligned in ferromagnetic order. The charge distribution in the system reflects the change of valence state of the Vb atoms from 5+ to 4+, and it is in line with changes of Vb-O bond lengths. The calculated Raman spectrum of the γ-LiV2O5 structure is in line with the experimental Raman spectra that allows a reliable assignment of all prominent Raman peaks. Comparison of the spectra of γ-LiV2O5 and γ′-V2O5 indicates spectral signatures of structural changes induced by the Li insertion into the γ′-V2O5 lattice. Results of the study present the opportunity of using Raman spectroscopy for characterization of structural modifications of the vanadate framework upon intercalation of guest species