Formation of Nanostructured Li4Ti5O12-Based Composites upon Hydrothermal Treatment of Their Components

— Nanostructured Li 4 Ti 5 O 12 -based composites in the form of microspheres consisting of randomly packed prism-like particles have been prepared via hydrothermal treatment of TiO 2 xerogel in aqueous LiOH solutions, followed by calcination of the reaction products at t ≥ 550°C. The phase composition of the hydrothermally prepared spherical particles has been shown to correspond to α-Li 2 TiO 3 . According to elemental analysis data, the titanium and oxygen were nonuniformly distributed over the microspheres. Sequential calcination of the microspheres at t ≤ 750°C led first to the α-Li 2 TiO 3 → β-Li 2 TiO 3 phase transformation and then to the formation of nanostructured Li 4 Ti 5 O 12 spinel or spinel-based composites (Li 4 Ti 5 O 12 /TiO 2 and Li 4 Ti 5 O 12 /β-Li 2 TiO 3 ). The Li 4 Ti 5 O 12 microspheres calcined at 750°C consisted of not only the major crystalline phase but also X-ray amorphous TiO 2 (anatase) and β-Li 2 TiO 3 as impurity phases, which could not be detected by X-ray diffraction.