The Li4Ti5O12/activated graphene nanoplatelets (Li4Ti5O12/a-GNPs) composites are prepared via a low-cost, green, one-pot hydrothermal process by using LiOH both as lithium source and activating agent for the first time. The LiOH solution concentration and hydrothermal time are optimized to obtain the pure Li4Ti5O12/a-GNPs. The synergistic effects of the nanosized Li4Ti5O12 and the three-dimensional porous a-GNPs endow the composites with convenient lithium ion diffusion channels and efficiently conductive structures for electron and ion transport. As anticipated, the Li4Ti5O12/a-GNPs deliver an outstanding rate capability of 125 and 113 mA h g−1 at 80 and 100 C, respectively, and an excellent cycling stability with 90.21% capacity retention after 2000 cycles at 10 C. These results are much better than those of the Li4Ti5O12/GNPs and pure Li4Ti5O12, demonstrating Li4Ti5O12/a-GNPs are promising anode materials for lithium-ion batteries of high current density applications.