H₂O-EG-assisted synthesis of uniform urchinlike rutile TiO ₂ with superior lithium storage properties

A facile green method to synthesize uniform nanostructured urchinlike rutile TiO₂ is demonstrated. Titanium trichloride was selected as the TiO₂ precursor, and a mixed solvent containing H₂O and ethylene glycol was used. By using this binary medium, the nucleation and crystal growth of rutile TiO₂ can be regulated, giving rise to very uniform urchinlike structures with tailorable sizes. As confirmed by the SEM and TEM analysis, large particles with dense aggregation of needle-like building blocks or small ones with loosely packed subunits could be obtained at different reaction conditions. The as-prepared samples were applied as the anode material for lithium-ion batteries, and they were shown to have superior properties with a high reversible capacity of 140 mA h g^-1 at a high current rate of 10 C for up to 300 cycles, which is almost unmatched by other rutile TiO ₂-based electrodes. A stable capacity of 88 mA h g^-1 can also be delivered at an extremely high rate of 50 C, suggesting the great potential of the as-prepared product for high-rate lithium-ion batteries.