Electrochemical performances of Si/TiO2 composite synthesized by hydrothermal method

Si/TiO2 composites as anode material for lithium ion batteries are synthesized by a simple hydrothermal method. X-ray diffraction, inductively coupled plasma and field-emission scanning electron microscopy are used to determine their phase structures, components and surface morphologies. The electrochemical properties of Si, TiO2 and Si/TiO2 composites are investigated and compared by galvanostatic cycling measurements, which exhibits the discharge capacities of 4, 121 and 395 mA h g−1 at 0.1 C after 50 cycles, respectively. Cyclic voltammogram measurements are carried out to further clarify the origin of excellent electrochemical performances of the Si/TiO2 composite. Surface morphologies of electrode plates after 10 cycles show that the Si/TiO2 composite electrode has more structural retention compared with its Si counterpart. All the experimental observations indicate that the performance improvement of Si/TiO2 composites could be attributed to TiO2 which suppresses the volume change of Si particles. On the other hand, TiO2 also contributes electrochemical activity in repeated cycling with relatively stable structure.