Fabrication and electrochemical properties of Si/TiO2 nanowire array composites as lithium ion battery anodes

• A novel material of TiO2 nanowire array/Si composite has been fabricated.
• TiO2 nanowire framework separates Si bulk apart and accommodates Si volume expansion.
• Mass ratio of Si to TiO2 is tuned to achieve the best electrochemical performance.
• Composite with 75% Si owns the highest capacity of 802.3 mA h g−1 after 200 cycles.

A novel material of Si/TiO2 nanowire array (TNA) composite has been designed and fabricated, to be used as anode material for lithium ion batteries. Firstly, Self-assembled and well-aligned rutile TiO2 nanowire arrays are synthesized on pretreated titanium substrate by solvothermal route. Subsequently, Si film is introduced into the interspace of the nanowires, forming a Si/TNA composite. The field-emission scanning electron microscopy (FE-SEM) and transmission electron microscope (TEM) images indicate that the dimension of TiO2 nanowires is 10 ± 2 nm wide. The TEM and Raman results reveal that Si contains amorphous and nanocrystalline phases. The composite with 75% Si content owns the best electrochemical performance, the first charge capacity reaches as high as 1480 mA h g−1, and remains at 802.3 mA h g−1 after 200 cycles.