Orderly integration of porous TiO2(B) nanosheets into bunchy hierarchical structure for high-rate and ultralong-lifespan lithium-ion batteries

Abstract TiO2(B) has stimulated great interests in lithium storage owing to the highest Li-ion mobility and theoretical capacity among all TiO2 polymorphs. However, the low conductivity and metastability of TiO2(B) still impede its practical application in lithium-ion batteries (LIBs). In this context, the porous TiO2(B) nanosheets offering rich lithium-insertion channels are rational appeals to enhancing the transport kinetics. And the firm 1D TiO2 nanowire can serve as a crossgirder to string together these nanosheets, which improves the deformation resistance of TiO2(B) nanosheets during repeated lithiation/delithiation processes. Herein, the motivation was realized by constructing a bunchy hierarchical structure (TiO2(B)-BH) in a facile solvothermal process. As an anode material for LIBs, TiO2(B)-BH exhibits high reversible capacity, long-term cycling stability (186.6 mA h g−1 at 1675 mA g−1 after 1000 cycles) and desirable rate performance. The multiple TiO2(B) nanosheets stringed by 1D nanowire possess fast pseudocapacitive behaviour, effective pathway for ion/electron transfer and high structural stability, leading to the superior electrochemical performance of TiO2(B)-BH. This orderly integration strategy of nanosheets can be extendedly applied to the architectural construction of electrode materials for other energy devices.