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

Abstract

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 LiMn 2O 4 structure using both the classical group factor analysis ( O h 7) and a local environment model. The RS and FTIR spectra are analysed on the basis of LiO 4 tetrahedra and MnO 6 octahedra building the lattice. RS and FTIR line intensities and positions remained in good agreement with the Fd3 m space group. Isotopic substitution of 6Li for 7Li leads the conclusion that the spectral features of the LiO 4 remains in the 350–400 cm −l and the vibrational modes of the MnO 6 expand over 450–650 cm −l. Vibrational spectra of the lithium-rich manganese oxide spinels are also presented for comparison with the λ-LiMn 2O 4 phase.