Solvothermal approach to nanocrystalline Li-Ti-O insertion hosts-solvent polarity effect

The cubic nanocrystalline Li-Ti-O oxides were prepared by the solvothermal reaction of TiO2 and LiOH at 200 degrees C in water and aliphatic alcohols with different dielectric constants. The reaction in all solvents leads to the formation of white ternary compounds containing Li, Ti, and O. The actual Li content in the prepared materials increases with decreasing polarity of the used solvent. All prepared materials are crystalline, and their structure can be described using a spinel structural model. The structure of materials prepared at a relative dielectric constant (epsilon(r)) value higher than 33 is characterized by Ti disorder when the Ti atoms are distributed between both types of the available octahedral sites with approximately the same probability. The tendency to form phases with Ti disorder decreases with decreasing epsilon(r) of the solvent. All prepared materials are active toward electrochemical Li insertion. The observed specific capacity ranges between 60 and 150 mAh/g.