Facile synthesis of Sn/TiO2 nanowire array composites as superior lithium-ion battery anodes

A novel material of Sn/TiO2 nanowire array (TNA) composite has been designed and fabricated to be used as anode material for lithium-ion batteries. Firstly, highly ordered, vertically oriented rutile TiO2 nanowire array is synthesized directly on titanium substrate by solvothermal procedure without any template. Subsequently, tin metal is chemically deposited into the interspace of the film, forming a TNA/Sn composite. By calcinations in atmosphere, the skin-deep Sn is oxidized to SnO2, and further turns to Li2O in Li-ion insertion process. The field-emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM) images indicate that the dimensions of TiO2 nanowires and Sn particles are 10 ± 2 nm and 8 ± 1 nm wide, respectively. The energy-dispersive X-ray spectroscopy (EDX) result reveals that the weight ratio of tin to TiO2 is 0.22. The first charge capacity reaches as high as 1610 mA h cm−3, and the capacity retention is 62.3% after 300 cycles.

► A novel material of TiO2 nanowire array/Sn composite has been fabricated. ► The TNA–Li2O framework ensures excellent cycling stability of the composites. ► Tin component brings high capacity and outstanding rate capability.