Porous TiO2(B)/anatase microspheres with hierarchical nano and microstructures for high-performance lithium-ion batteries

Novel hierarchical porous TiO2(B)/anatase microspheres have been prepared by a facile solvothermal approach and evaluated as anode materials for advanced lithium-ion battery applications. The obtained porous microspheres, with diameters ranging from 2.5 to 5.5 mu m, are assembled by porous TiO2 nanosheets with the lateral size of a few micrometers and thickness of similar to 13 nm; whilst, the nanosheets are formed by aggregations of nanosized primary TiO2 crystallites (similar to 5-7 nm). The hierarchical porous structures are verified by BET test results with a typical type-IV isotherm curve, a high surface area (similar to 186.2 m(2) g(-1)) and two kinds of pores (similar to 4 and 8.3 nm). The hierarchical porous TiO2 microspheres present excellent electrochemical performance with high Li storage capacity and excellent high-rate cycling capability (a specific capacity of 117 mAh g(-1) at the rate of 4000 mA g(-1) after 4500 cycles), which might be attributed to the enhanced Li+ diffusion and electronic conductivity induced by the hierarchical microstructures, the TiO2(B)/anatase heterojunction, and the pseudocapacitance of TiO2(B). Such hierarchical porous materials might be promising for applications in advanced power type lithium-ion batteries. (C) 2013 Elsevier Ltd. All rights reserved.