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

Abstract

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 ≤ Ts ≤ 350 °C. Phase-pure and well-crystallized TiO2 thin films grown at Ts = 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 Ts 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.