Silicon Anodes for Lithium‐Ion Batteries Based on a New Polyimide Binder

Silicon is a promising candidate for replacing graphite in anodes for advanced Li‐ion batteries due to its high theoretical gravimetric energy density. However, silicon as an active anode material suffers from significant volume changes upon lithiation/delithiation, causing fast capacity fading. The performance of silicon anodes depends on the polymeric binders used, which form well‐bound Si particles matrices that accommodate the strains developed during their repeated lithiation, thus maintaining their integrity. Silicon anodes in Li‐ion batteries offer high energy density, but significant volume changes lead to fast capacity fading. This study investigates the use of thermal treatment on polyimide P84 binder for metallurgical Si anodes. Treatment of P84 PI binders at 400 °C shows optimal performance, enhances adhesion and integrity, reduces volume change effects, and forms more stable SEI films.