TiO₂-B fibres derived from K₂Ti₄O₉ as fast lithium intercalation negative material

TiO₂-B fibers were obtained by heat treatment of the precursor of tetratitanate(H₂Ti₄O₉· xH₂O), which was derived from potassium tetratitanate(K₂Ti₄O₉)via ion exchange. Structure characterization showed that TiO₂-B fibers sintered at 600°C still maintained pure phase and high crystallinity. Lithium insertion performance indicated that the capacity performance of this TiO₂-B material sintered at 600°C was up to 225 mA·h·g^-1, and was 50 mA·h·g^-1(i. e. 22.5%)higher than that of the anatase material with similar structure. The TiO₂-B fibers exhibited excellent rate performance mainly because the open structure of the TiO₂-B fibers led to fast lithium-ion diffusion coefficient of 1.92×10^-7 cm²·s^-1, which was nearly 8 times higher than that of anatase material. 1 C stability test showed that the capacity of TiO₂-B fiber was 159 mA·h·g^-1 after 80 cycles, which was about 1.5 times higher than the capacity of anatase material(64 mA·h·g^-1).