Nano-crystalline Li4Ti5O12 with an average size of 18nm was in situ grown on graphene sheets using ionic liquid of C12H23ClN2 [Omim]Cl as the exfoliated agent. Such unique nanostructure provides a high electrode/electrolyte area for the electron transport and the nanosized Li4Ti5O12 leads to a short path for the lithium ion transfer. When used as an anode material for lithium-ion battery, the Li4Ti5O12/graphene nanostructure exhibits excellent reversibility (159mAhg−1 at 0.5C after 100 cycles) and high-rate performance (162mAhg−1 at 0.2C, 148.5mAhg−1 at 20C).