Controllable growth of TiO2-B nanosheet arrays on carbon nanotubes as a high-rate anode material for lithium-ion batteries

To meet the increasing demands of electrode materials with high capacity and fast charge-discharge capability for next-generation lithium-ion batteries (LIBs), well-designed nanostructures of carbon-supported metal oxides have been extensively investigated. Here we design and fabricate a novel hybrid nanoarchitecture of carbon nanotubes (CNTs) coated with TiO2-B nanosheets (CNTs@TiO2-B NSs) by using an imidazolium-based ionic liquid of [Bmim][BF4] as a guiding agent. The ionic liquid of [Bmim][BF4] interacts with CNTs via cation-π interactions and further guides the in situ growth of TiO2-B nanosheet arrays onto CNTs. The resultant hybrid nanoarchitecture possesses a large specific surface area, porous nature, and abundant electron/lithium pathways. These features combined with the fast pseudocapacitive behavior and the reduced ion-diffusion length of TiO2-B nanosheet arrays, contribute to a high reversible capacity and superior rate capability for LIB applications.