TiO₂ thin films on Au/Ti/SiO₂/textured Si substrates as high capacity anode materials for Li-ion batteries

In this paper, we investigate the structural and electrochemical properties of TiO₂ thin films deposited on multilayered Au/Ti/SiO₂/(100) textured-Si substrates by electron-beam evaporation technique at various substrate temperatures in the range 25 ≤ T_s ≤ 350 °C. Phase-pure and well-crystallized TiO₂ thin films grown at T_s = 250 °C exhibit the typical (101) Bragg line of the tetragonal anatase structure with crystallite size of about 30 nm. The surface morphological analysis reveals the uniform growth of prismatic shaped grains (40–120 nm in size) deposited on pyramidal architectures of textured substrates. The electrochemical tests show that TiO₂ thin films electrodes deposited at T_s of 250 °C deliver a specific discharge capacity of 74 μAh cm⁻² μm⁻¹ at a current density of 1 mA cm⁻² with 96% capacity retention after 100 cycles. Hence, the experimental results demonstrate that TiO₂ thin films can be used as anodes of planar solid-state Li-ion microbatteries.