Abstract
A Sn-doped TiO 2 nanocrystallite with the composition of Sn 0.1 Ti 0.9 O 2 was prepared by hydrothermal co-precipitation followed by thermal annealing at 600 °C for 2 hours. Results combining high-resolution transmission electron microscopy, in situ XRD, ex situ XAS, and electrochemical impedance spectroscopy indicate that Sn 0.1 Ti 0.9 O 2 underwent restructuring to give Sn-substituted TiO 2 (Sn to Ti sites) by a lithiation reaction at 0.1C in a lithium-ion battery. The capacity and cyclability of Sn 0.1 Ti 0.9 O 2 were increased by ∼73% (to ∼598 mA h g -1 ) and ∼17.4% compared with those of TiO 2 (∼345 mA h g -1 and ∼22%) at 0.1C until the 250 th cycle. Our results proved that these improvements were caused by the self-aligned formation of Sn-Ti oxide and the subsequent formation of a SnLi x local alloy at Ti sites.