Electrochemical Investigation of Lithium Intercalation in MOCVD Derived Nanostructured Anatase/Rutile TiO2

Abstract

In this paper we report on the lithium reversible storage in titanium dioxide (TiO2) prepared by metal-organic chemical vapor deposition (MOCVD). Electrochemical properties in terms of lithium reversible insertion depend on the deposited microstructure. For thick films deposited on silicon wafer electrochemical activity of the anatase type of TiO2 is registered in the potential range 1.8-2.1 V vs. Li. For thinner films the intercalation reaction takes place in two potential ranges: 1.8-2.1 V vs. Li and below 1.4 V vs. Li. The second electroactivity range is attributed to lithium insertion into rutile. We found that the decrease of the lower potential limit (0.5 V instead of commonly used 1 V) leads to an increase of the recovered capacity. In consequence the investigated MOCVD TiO2 demonstrates high reversible capacity of about 300 mAhg-1.