Ab initio study on the topological Li insertion in titanium oxide

Lithium insertion into anatase was studied by XRD, XPS and ab initio calculations. Lithium insertion in anatase was carried out by n-butyllithium and the product was analyzed by XRD and XPS. A distortion of anatase cell by the lithium insertion and removal was estimated by the ab initio periodic pseudo-potential calculations. As a result, a crystallographic transition from tetragonal to orthorhombic along with a considerable hysteretic change of the cell volume were estimated, which is well consistent with the previously reported XRD cell dimensions. In the lithium-removal process, the wide plateau in calculated cell volume was observed for LixTiO2 where lithium uptake x ranges from 0.25 to 1.