Pyrrolidinium-based Gel Composites for Reprocessable, Flame-Retardant Electrolytes

Abstract

Flame retardant and reprocessable gel composites composed of a pyrrolidinium-based poly(ionic liquid) were successfully prepared by incorporating surface-modified nanoparticles functionalized with ionic liquids or ureidopyrimidinone groups. Covalent functionalization was verified through CP-MAS 29Si NMR, FT-IR, and thermogravimetric analysis. Surface modified NPs significantly improved the dynamic characteristics of synthesized gel composites, yielding composites with enhanced reprocessability and remarkable mechanical flexibility, reaching elongation at break up to 460%, solely through reversible dynamic interactions without the need for permanent covalent crosslinking. Upon reprocessing the ionic conductivity of gels was efficiently restored, reaching values of 2.2 × 10–4 S·cm⁻¹ at room temperature. The composites further exhibited excellent thermal stability up to 330 °C, and an inherently flame-retardant nature classified as UL 94 V-0 grade. These combined features underscore the potential of the developed PIL-based gel composites for safe, durable, and high-performance applications in electrochemical and flexible devices