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

Abstract

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.