Lithium diffusion in sputter-deposited Li4Ti5O12 thin films

F. Wunde, F. Berkemeier, G. Schmitz

Zusammenfassung

Li4Ti5012 (LTO) thin films are deposited by dc-ion beam spurtering at different oxygen partial pressures and different substrate temperatures. In order to investigate, how these two parameters influence the atomic structure, the specimens are characterized by X-ray diffraction and transmission electron microscopy. Electrochemical characterization of the films is done by cyclic voltammetry and chrono­ potentiometry. To determine an averaged chemical diffusion coefficient of Iithium, a method is devel­ oped, evaluating c-rate tests. The results obtained by this method are compared to results obtained by the weil established galvanostatic intermittent titration technique (GlTT), which is used to determine a concentration dependent diffusion coefficient of Iithium in LTO.