Spatial Extent of Lithium Intercalation in Anatase TiO₂

Citations Over TimeTop 10% of 1999 papers

Abstract

Thin smooth anatase TiO2 films are obtained by electron beam evaporation of reduced TiO2. These films show a preferential (004) orientation when deposited on electron beam evaporated amorphous titanium. Electrochemical lithium insertion into these films is studied with several optical and electrochemical techniques. A coloration efficiency of 13 cm2 C-1 is found, which is twice as high as that reported for TiO2 films grown by chemical vapor deposition (CVD). Potential-dependent capacitance measurements show that after the extraction of lithium ions has taken place a small region at the surface of the electrode has a much higher dielectric constant than that of the bulk of the electrode. This is explained by the presence of irreversibly trapped lithium ions in the region where a (reversible) phase transformation from anatase TiO2 to anatase Li0.5TiO2 has occurred. The extent of this region depends strongly on the intercalation potential; values of 7 and 17 nm are found after 2.5 h of intercalation at −1.0 and −1.2 V vs SCE, respectively. The dielectric constant of the modified surface region is found to range between 500 and 900. A scheme is proposed that describes the mechanism of lithium insertion in terms of a moving TiO2|Li0.5TiO2 phase front.

Related Papers

• → Electrochemical Properties of Hydroxyapatite Crystal Surfaces on Anatase Photocatalysts(2005)13 cited
• → On the synthesis of nanostructured TiO2 anatase phase and the development of the photoelectrochemical solar cell(1999)22 cited
• → Intercalation Compounds of Transition-Metal Dichalcogenides(1994)8 cited
• → A study on the interaction of V2O5/TiO2 (anatase) by high-resolution electron microscopy (hrem)(1986)50 cited
• → GROWTH, SURFACE CHARACTERIZATION, AND REACTIVITY OF TIO2 ANATASE FILMS-EPSCOR(2004)