Thermally Crosslinked Polyimide Binders for Si-alloy Anodes in Li-ion Batteries

Abstract

Silicon (Si) has attracted considerable attention due to its high theoretical capacity compared to conventional graphite anode materials. However, Si-based anode materials suffer from rapid capacity loss due to mechanical failure caused by large vol-ume change during cycling. To alleviate this phenomenon, crosslinked polymeric binders with strong interactions are highly desirable to ensure the electrode integrity. In this study, thermally crosslinked polyimide binders were used for Si-alloy anodes in Li-ion batteries. The crosslinked polyimide binder was found to have high adhesion strength, resulting in enhanced electrode integrity during cycling. Therefore, the Si-alloy anodes with crosslinked polyimide binder provide enhanced electrochemical performance, such as Coulombic efficiency, capacity retention, and cycle stability.