Li-ion diffusion in amorphous Si films prepared by RF magnetron sputtering: A comparison of using liquid and polymer electrolytes

Amorphous Si films were prepared by radio frequency magnetron sputtering on Cu substrates and were characterized by X-ray diffraction and scanning electron microscopy. The potential dependence of Li-ion chemical diffusion coefficients, image, in the films was determined by electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration technique (PITT) using liquid and polymer electrolytes. The image values obtained using the polymer electrolyte were lower than those using the liquid electrolyte. It was found that the image values of the Si film measured by PITT and EIS using the polymer electrolyte were in the range of 4 × 10−13–2 × 10−13 cm2 s−1 and 4 × 10−13–10−14 cm2 s−1, respectively, at 50 °C.