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

Abstract

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, D ˜ Li , in the films was determined by electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration technique (PITT) using liquid and polymer electrolytes. The D ˜ Li values obtained using the polymer electrolyte were lower than those using the liquid electrolyte. It was found that the D ˜ Li 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 cm 2 s −1 and 4 × 10 −13–10 −14 cm 2 s −1, respectively, at 50 °C.