Nb-Doped Rutile TiO₂ Mesocrystals with Enhanced Lithium Storage Properties for Lithium Ion Battery

A homogeneous Nb-doped rutile TiO₂ mesocrystal material was synthesized successfully through a facile hydrothermal route. The incorporation of Nb⁵⁺ not only promotes the crystallization of the building subunits of the rutile TiO₂ mesocrystal, but also improves the electrochemical performance at higher current rates. A capacity of 96.3 mAh g^-1 at a current density as high as 40 C and an excellent long-term cycling stability with a capacity loss of approximately 0.006 % per cycle at 5 C could be achieved when an appropriate amount of Nb⁵⁺ was doped into rutile TiO₂ mesocrystal. The reasons for the improvement of rate capability may be attributed to the enhancement of electronic conductivity, Li-ion diffusion kinetics, and the surface storage property for the Nb-doped rutile TiO₂ mesocrystal.