A study at room temperature and 55 °C on the charge–discharge characteristics of Si(100 − x)Alx thin film anode for Li-ion batteries

In this study, Al was added into Si matrix as the buffer (Si90Al10, Si75Al25 and Si55Al45) by co-sputtering to prevent the dramatic volumetric expansion of a pure Si thin film anode during lithiation and delithiation. The electrochemical properties and structural characteristics of Si(100 − x)Alx (at.%) films at room temperature and 55 °C were investigated. At 55 °C, the higher lithiation and delithiation quantity was accompanied by a dramatic volumetric expansion which increased the capacity but degraded the stability. In addition, the resistance against electrochemical reactions was controlled by the diffusion rate of lithium ions at 55 °C. After charge–discharge, the Si–Al thin film had undergone recrystallization and had been affecting the 55 °C charge–discharge characteristics of the thin film anodes.