In battery research, the development of analytical techniques is of key importance for determining intrinsic properties of active materials ultimately dictating the battery performance. We report the application of nano-impact electrochemistry to gain insight into the intrinsic properties of commercial battery materials i.e. TiO2 particles in non-aqueous media. Potentiostatic lithiation measurements do not only provide qualitative information about the rate-limiting step in the lithiation process, but also demonstrate that nano-impact electrochemistry is a suitable technique in non-aqueous media in complete absence of oxygen and water. Our results reveal that the intrinsic lithiation rate of individual TiO2 particles is not – as generally assumed – determined by interfacial ion transfer kinetics, mobility of ion and/or electrons in the bulk of the particle, but by the solid-solid electron transfer. These findings have important implications for future studies of fundamental properties of battery materials considering that charge transfer in battery electrodes does not always obey Butler-Volmer kinetics.