Preparation of SiOx–TiO2/Si/CNTs composite microspheres as novel anodes for lithium-ion battery with good cycle stability

Si/carbon and SiO_x/carbon composites have been widely studied to meet the increasing demand for high-energy-density lithium-ion batteries. However, it is challenging to seek a balance between high specific capacity and good-mechanical-structure stability. Herein, a micro-level SiO_x–TiO₂/Si/CNTs composite sphere is prepared as a novel anode material. First, the liquid-phase co-deposition method is used to synthesize SiO₂–TiO₂ composite uniformly distributed at the primary particle level. Then, carbon nanotubes (CNTs) and a certain amount of Si nanoparticles are added to conduct high-energy ball milling, during which lithium-inactive SiO₂ phase converts into active SiO_x with partial reduction and oxygen loss. Benefiting from the multi-dimensional electronic and ionic conductive networks provided by cross-linked CNTs and evenly mixed nano-sized TiO₂, as well as an optimized balance between high-specific-capacity nano-Si and good-mechanical-structure-stability SiO_x, the obtained SiO_x–TiO₂/Si/CNTs composite microspheres demonstrate a promising cycle stability when used as a negative material (~ 800 mAh g⁻¹ after 100 cycles at 100 mA g⁻¹). This work offers a facile strategy for large-scale production of novel SiO_x-based composite anode in high-performance lithium-ion batteries.