The synthesis of dual phase Li₄Ti₅O₁₂/TiO₂(B) composite remains a tremendous challenge due to the easy formation of anatase TiO₂ instead of Li₄Ti₅O₁₂ in the process. In this work, Li₄Ti₅O₁₂/TiO₂(B) heteronanostructures comprising porous TiO₂(B) nanofibers integrated with Li₄Ti₅O₁₂ nanocrystals are synthesized and applied as anode for lithium-ion batteries. Benefiting from the complementary advantages of higher theoretical capacity of TiO₂(B) with favourable pseudocapacitive behaviour and excellent cyclability of Li₄Ti₅O₁₂, this heteronanostructure demonstrates a superior lithium-ion storage performance in terms of high discharge capacity and remarkable long-term stability. As a result, Li₄Ti₅O₁₂/TiO₂(B) heteronanostructures manifest discharge capacity of 130 mAhg⁻¹ and capacity retention of 93 % at high rate of 1.75 Ag^-1, compared to those of TiO₂(B) pristine of 90 mAhg⁻¹ and 75 %. The superior electrochemical performance demonstrated by Li₄Ti₅O₁₂/TiO₂(B) heteronanostructure reveals a new direction of integration of Li₄Ti₅O₁₂ into TiO₂(B) to improve both the capacity performance and cyclability.

Acknowledgements

This project is financially supported by Innovation and Technology Fund (ITS/378/13) and Internship Programme (InP/299/14) from Innovation and Technology Commission, Hong Kong, HKU Strategic Research Theme on Clean Energy, University Development Fund for Initiative for Clean Energy and Environment, and our industry partner – Gold Peak (GP) Batteries Limited.