In-situ crosslinked polyetherimide/BNNS composites with ultrahigh charged-discharged efficiency at high temperature

High performance dielectric polymer composites for capacitive energy storage have been a hot topic in recent years. However, dielectric materials tend to breakdown at high temperature, and its charged-discharged efficiency is greatly reduced. Therefore, preparing high-efficient high-temperature dielectric material is the main challenge in this field. In this work, based on the synergistic effect of in-situ composite and controlled thermal cross-linking, the thermal conducting nano filler and crosslinking system composite has ultra-high charged-discharged efficiency at high temperature. It is proved that the addition amount of BNNS for the peak performance of this kind of composite is 10 vol% and the discharge energy density is 4.58 J/cm3 and the charged-discharged efficiency reaches 96 % at 150 °C and 500 MV/m. At 200°C and 300 MV/m, these are 1.76 J/cm3 and astonishing 95 %. It is expected to be a candidate for a new generation of high temperature resistant dielectric materials.