Aerosol synthesis of trivalent titanium doped titania/carbon composite microspheres with superior sodium storage performance

Trivalent titanium doped titania/carbon (TiO_2–x/C) composite microspheres have been prepared by a facile aerosol method (ultrasonic spray pyrolysis) using titanium (Ⅳ) bis(ammonium lactato)dihydroxide (TiBALDH) as the sole precursor. The obtained TiO_2–x/C microspheres have particle sizes in the range of 400–1, 000 nm. When evaluated as anode material for sodium-ion batteries (SIBs), they provide a high reversible capacity of 286 mA·h·g^–1 with good cycling performance. A capacity of 249 mA·h·g^–1 can be achieved after 180 cycles at 50 mA·g^–1, which is more than three times higher than that of white TiO₂ microspheres (77 mA·h·g^–1). The superior sodium storage performance of these TiO_2–x/C composite microspheres can be attributed to the simultaneous introduction of Ti³⁺ and oxygen vacancies, ultrafine grain size, as well as the conductive carbon matrix. This study provides a facile and effective approach for the production of TiO_2–x/C nanocomposites with superior sodium storage performance.