Preparation and characterization of nanosized multi-sphere Si-TiO2 based composites for lithium storage

The Si-TiO2 based composites with a nanosized multi-sphere structure have been developed as novel anode for lithium ion cells. The Si spheres are highly embedded within the titanium dioxide nanoparticles via a hydrothermal synthesis route. The as-proposed sphere-stack like morphology achieves a superior cycling stability for lithium storage. The existence of TiO2 is in favor for the mechanical stability of Si during charge-discharge and conversely reduces the obtained capacity of the composite. Furthermore, the Si/TiO2 composite is coated by pyrolysized carbon. The reversible discharge capacity of the Si/TiO2/C composite reaches to 976 mAh g−1after 50 cycles. Carbon coating is beneficial for the rate capability of the Si/TiO2 based composite.