Lattice vibrations of materials for lithium rechargeable batteries I. Lithium manganese oxide spinel

Raman scattering (RS) and Fourier transform infrared (FTIR) spectroscopy have been applied to the study of local structure of lithium manganese oxides. We report the analysis of the vibrational spectra of spinel LiMn2O4 structure using both the classical group factor analysis (Oh7) and a local environment model. The RS and FTIR spectra are analysed on the basis of LiO4 tetrahedra and MnO6 octahedra building the lattice. RS and FTIR line intensities and positions remained in good agreement with the Fd3m space group. Isotopic substitution of 6Li for 7Li leads the conclusion that the spectral features of the LiO4 remains in the 350–400 cm−l and the vibrational modes of the MnO6 expand over 450–650 cm−l. Vibrational spectra of the lithium-rich manganese oxide spinels are also presented for comparison with the λ-LiMn2O4 phase.