Porous TiO₂ nanowire microsphere constructed by spray drying and its electrochemical lithium storage properties

Porous TiO2 nanowire microspheres with greatly decreasing agglomeration were successfully prepared by spray drying of hydrothermal reaction suspension, followed by calcination at 350°C. The as-obtained nanowire microspheres with TiO2-B structure reach an initial discharge capacity 210 mAh g(-1) with an irreversible capacity 25 mAh g(-1) at a current density of 20 mA g(-1). For the 450°C-calcined one with anatase TiO2 crystal structure, the initial discharge capacity is 245 mAh g(-1) but with a much higher irreversible capacity of 80 mAh g(-1). The hierarchical porous structure in the 350°C-calcined TiO2 nanowire microspheres collapsed at 450°C, annihilating the main benefit of nanostructuring.