Raman spectra of the electrochemically lithiated TiO₂ anatase evidence that Li intercalation induces complex spectral features in the high wavenumber range. These modes can be assigned to the stretching vibrations of Li-O valence bonds. Two theoretical approaches are used to describe the vibrations of Li atoms within the TiO₂ lattice. First, the quantum-mechanical calculations of molecular clusters imitating the Li...TiO₂ system, which showed formation of covalent Li-O bonds and allowed an estimation of their force constants. Second, the lattice dynamics simulation which enabled to predict the whole spectrum of Li-phonons and their interaction with TiO₂ lattice vibrations. Complex structure of the observed Raman spectra is explained by multiplicity of the Li positions. This results in multiple Raman bands originated from the Li atom vibrations covering a wide frequency range from 450 up to 950 cm^-1.