Preparation of SiO₂nanowire arrays as anode material with enhanced lithium storage performance

Abstract

SiO₂ nanowire arrays have been prepared by a template-assisted sol gel method and used as a negative electrode material for lithium ion batteries. Amorphous SiO₂ was confirmed by X-ray diffraction and Fourier transform infrared spectroscopy. The results of scanning electron microscopy and transmission electron microscopy confirmed that the SiO₂ nanowire had a diameter of about 100 nm and a length of about 30 μm. Cyclic voltammetry and constant current charge and discharge tests showed the prepared SiO₂ nanowire arrays were electrochemically active at a potential range of 0.05-3.0 V. At a current density of 200 mA g^-1, the first discharge specific capacity was as high as 2252.6 mA h g^-1 with a coulombic efficiency of 60.7%. Even after about 400 cycles, it still maintained 97.5% of the initial specific capacity. Moreover, a high specific capacity of 315 mA h g^-1 was exhibited when the current density was increased to 2500 mA g^-1. SiO₂ nanowire array electrodes with high reversible capacity and good cycle performance provide potential anode materials for future lithium-ion batteries.