Chemo-mechanical effect of chlorine modified TiO2 coatings on LMO

Abstract

A thin-film model electrode was used to evaluate the performance of lowly and highly chlorine modified TiO2 coatings. The coatings are applied using ALD on RF sputtered LiMn2O4 thin-films. Careful analysis of the ALD process indicates direct interaction between the precursor and the active material, leading to the formation of an interphase layer containing a high concentration of chlorine. Distinct differences in the performance of the two types of coatings arise dependent on the insertion potential (i.e. 3 V or 4 V insertion region) which was being evaluated. A link to the mechanical properties of the coating materials is hypothesized and evaluated using nanoindentation for mechanical assessment of TiO2 and chlorine modified TiO2.