The electronic structure and ionic diffusion of nanoscale LiTiO2 anatase

• DOI: 10.1039/b823142g
• Publication Date: 2009-05-11T15:00:15Z
• Authors: W. J. H. Borghols; D. Lützenkirchen-...; U. Haake; E. R. H. van Eck; F. M. Mulder; M. Wagemaker
• Keywords: info:eu-repo/classification/ddc/540; 01 natural sciences; 0104 chemical sciences

Upon lithium insertion in the pristine TiO2 anatase phase theoretical maximum of LiTiO2 can be reached crystallite sizes less than ∼10 nm, whereas bulk compositions appear limited to Lix≈0.6TiO2 at room temperature. Both X-ray absorption spectroscopy (XAS) and ab initio calculations have been applied probe electronic structure newly formed phase. These results indicate that a large majority Li-2s electrons reside Ti-3d(t2g)/4s hybridized site. About 10% these are transferred non-localized states which makes this compound good conductor. Ionic conductivity is probed by nuclear magnetic resonance (NMR) relaxation experiments indicating relatively small hopping rates between Li-ion sites LiTiO2. Formation poor ionic-conducting surface particles explains why micro-anatase LixTiO2 not able reach capacity temperature, nano-sized materials cannot (dis)charged high rates.