Enhanced Discharged Energy Density in Polyetherimide Composites by Boron Nitride/Aluminum Nitride Hybrid Fillers

Flexible dielectric polymer composites occupy a significant position in electronic devices. However, many investigations focus on complicated synthetic methods to enhance the energy density of dielectrics. Developing simple and feasible strategy is meaningful and urgent for their acceptance to various applications. Herein, we utilize the high thermal conductivity and electrical insulation characteristic of Boron nitride and Aluminum nitride (BN/AIN) as the hybrid fillers for polyetherimide (PEl) matrix to increase dielectric constant and breakdown strength. This combination resulted in a high discharged energy density of 8.39 J/cm
³
at 500 kV/mm with a high efficiency of 90.5% at a low filler fraction. This strategy provides a feasible option for a scalable manufacturing of high performance composite films in the future.