Enhanced cycling performance and rate capacity of SiO anode material by compositing with monoclinic TiO2 (B)

Silicon monoxide (SiO) is regarded as a great potential anode material for high-energy lithium-ion batteries (LIBs) owing to the high theoretical specific capacity (2650 mAh g−1), low voltage platform, eco-friendly and rich reserves. However, the particle pulverization, induced by large volume change during (de)lithiation, can result in the capacity degrading significantly. As we all know, it is a good strategy that using TiO2 to modify the SiO-based anode. TiO2 can serve as rigid outer layer to keep the structural integrity. In addition, the electrochemical performances of monoclinic TiO2 (B) are better than anatase and rutile TiO2. Therefore, compositing with TiO2 (B) is an admissible method to enhance the electrochemical properties of SiO-based materials. And the pretreated-SiO/TiO2 (B) composites (abbreviated as p-STB) are prepared by hydrothermal treatment at 180 °C for 12 h and then calcined at 325 °C for 2 h. In this paper, p-STB-1 and p-STB-2 are prepared that the weight ratios p-SiO and TiO2 (B) are 4:1 and 3:1, respectively. The structure and components of composites are also performed on X-ray diffraction (XRD), Fourier transform infrared reflectance (FT-IR) spectroscopy, scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). For p-STB, TiO2 (B) is mainly covered on the surface of pretreated SiO (p-SiO). The Li-ion diffusion coefficients of as-prepared materials are calculated by cyclic voltammetry and electrochemical impedance spectroscopy. The electrochemical test results suggest that the p-STB-1 has batter cycling performance (730 mAh g−1 after 100th cycle) and admirable rate capacity (450 mAh g−1 under 3.2 A g−1). The modified method, which was compositing with TiO2 (B), is beneficial to the commercialization of SiO-based materials.