Facile hydrothermal preparation, characterization and multifunction of rock salt-type LiTiO2

Abstract

Disordered rock salt-type LiTiO2 was successfully synthesized by a simple hydrothermal method. The crystal structure and morphology of samples obtained under different alkali concentrations were characterized. The alkaline solution affected the crystal morphology and growth process. LiTiO2 synthesized at 180 °С with [OH−] = 0.4–3.0 M for 12 h owned high crystallinity and uniform octahedral shape with an axial length of less than 100 nm. TiO2 underwent hydrolysis into TiO68− octahedral units, which rearranged the cubic intermediate TiO with shared edges. Then, Li ions infiltrated into the TiO lattice to randomly replace Ti ions to generate the cubic LiTiO2 target. And the moderate alkali concentration could heighten the content of LiTiO2 and enhance the photodegradative ability of LiTiO2 to methylene blue. LiTiO2 was a direct gap semiconductor with a band gap of 3.75 eV. The results of electrochemical properties showed that LiTiO2 as a lithium-ion battery anode material had high discharge specific capacity, excellent rate performance, good cycle stability and durability. At the current density of 100 mA/g, the largest initial discharge specific capacity of LiTiO2 was up to 479.9 mA h/g with the initial Coulombic efficiency of 55.7%. These results illustrated that LiTiO2 is a good multifunctional material.