Enhanced High‐Temperature Energy Storage Performance of All‐Organic Composite Dielectric via Constructing Fiber‐Reinforced Structure

Optimizing the high-temperature energy storage characteristics of dielectrics is great significance for development pulsed power devices and control systems. Selecting a polymer with higher glass transition temperature (Tg) as matrix one effective ways to increase upper limit operating temperature. However, current high-Tg polymers have limitations, it difficult meet demand only polymer. For example, polyetherimide has high-energy efficiency, but low breakdown strength at high temperatures. Polyimide corona resistance, efficiency. In this work, combining advantages two polymer, novel fiber-reinforced microstructure designed. designed extremely fine fibers distributed in composite dielectric, which will facilitate reduction conductivity loss polyimide. At same time, due resistance polyimide, dielectric enhanced. After polyimide content best determined, molecular semiconductors (ITIC) are blended into further improve Ultimately, excellent properties obtained. The 0.25 vol% ITIC-polyimide/polyetherimide exhibits density discharge efficiency 150 °C (2.9 J cm−3, 90%) 180 (2.16 90%). This work provides scalable design idea high-performance all-organic dielectrics.