Real‐Time Dilation Observation of Si‐Alloy Electrode Using Thermally Treated Poly (Amide‐Imide) as a Binder for Lithium Ion Battery

Real time dilation behaviors of a Si‐Ti‐Fe‐Al alloy electrode adopting a poly (amide‐imide) binder were investigated to understand the effects of thermal treatment temperature for PAI binder on the electrochemical performance of the Si‐alloy electrode using an in‐situ electrochemical dilatometer. In situ measurement of the electrode thickness showed that the changes in the volume of the Si electrode was suppressed by heat treatment greater than 300 °C, which well agreed with the improved cycle performance of the Si‐alloy electrode thermally treated at the same temperature. Differential dilation plots of the Si‐alloy electrodes were found to reveal more detailed changes in the volume of the Si‐alloy electrode, thus showing that the enhanced mechanical strength of thermally treated PAI effectively could control the expansion and contraction of the Si‐alloy electrode and ensuring a more stable cycle performance of the Si‐alloy electrode.