Composites of spinel Li 4 Ti 5 O 12 –ramsdellite Li 2 Ti 3 O 7 (Li 4 Ti 5 O 12 –Li 2 Ti 3 O 7 ) were prepared and evaluated for anode materials in lithium-ion batteries. Our experimental results turns out that sintering temperatures and carbon content play important roles in forming these composites. Under vacuum, it is found that Li 4 Ti 5 O 12 –Li 2 Ti 3 O 7 composites can be synthesized at around 600°C under the help of citric acid. According to the XRD patterns, its reaction mechanism is suggested in this study. In addition, electrochemical testing demonstrates that the presence of Li 2 Ti 3 O 7 in the prepared sample modifies the charge/discharge behavior of Li 4 Ti 5 O 12 , which makes it easily to monitor its SOC/SOD according to its voltage profile.