A flexible, fireproof, composite polymer electrolyte reinforced by electrospun polyimide for room-temperature solid-state batteries

Solid-state batteries (SSBs) have attracted considerable attention for high-energy-density and high-safety energy storage devices. Many efforts have focused on the thin solid-state-electrolyte (SSE) films with high room-temperature ionic conductivity, flexibility, and mechanical strength. Here, we report a composite polymer electrolyte (CPE) reinforced by electrospun PI nanofiber film, combining with succinonitrile-based solid composite electrolyte. In situ photo-polymerization method is used for the preparation of the CPE. This CPE, with a thickness around 32.5 µm, shows a high ionic conductivity of 2.64 × 10⁻⁴ S cm⁻¹ at room temperature. It is also fireproof and mechanically strong, showing great promise for an SSB device with high energy density and high safety.