Electrochemical and chemical (with n-butyllithium) insertion of Li into TiO2 (anatase) is studied by Raman spectroscopy and by in situ Raman spectroelectrochemistry. Four isotopologue combinations in the system, namely (LixTiO2)-Li-6/7-O-16/18 (with x being the insertion coefficient), are prepared and studied.
Spectral assignment is supported by numerical simulations using DFT calculations. The combination of experimental and theoretical Raman frequencies with the corresponding isotopic shifts brings new inputs for several still open questions about the Li-insertion into TiO2 (anatase).