In-situ construction of Li₄Ti₅O₁₂/rutile TiO₂ heterostructured nanorods for robust and high-power lithium storage

Li₄Ti₅O₁₂ is considered as a safe and stable anode material for high-power lithium-ion batteries due to its “zero-strain” characteristic during the charge/discharge. However, the intrinsically low electronic conductivity leads to a deterioration in high-rate performance, impeding its intensive application. Herein, the Li₄Ti₅O₁₂/rutile TiO₂ (LTO/RT) heterostructured nanorods with tunable oxide phases have been in-situ fabricated by annealing the electrospun nanofiber precursor. By constructing such a heterostructured interface, the as-prepared sample delivers a high capacity of 160.3 mAh·g^–1 at 1 C after 200 cycles, 125.5 mAh·g^–1 at 10 C after 500 cycles and a superior capacity retention of 90.3% after 1,000 cycles at 30 C, outperforming the heterostructure-free counterparts of pure LTO, RT and the commercial LTO product. Density Functional Theory calculation suggests a possible synergistic effect of the LTO/RT interface that would improve the electronic conductivity and Li-ion diffusion.