Ultra-high power density in poly(arylene ether nitrile)-based composites containing barium titanate and boron nitride nanosheets

Barium titanate (BT) nanoparticles were surface coated by a silane coupling agent (KH550) and core–shell structured nanoparticles (named KH550@BT) were obtained. Similarly, BT nanoparticles coated by polydopamine (PDA) were named as PDA@BT. Meanwhile, boron nitride (BN) nanosheets (BNNS) were successfully unstripped from block BN. Then, two kinds of ternary poly(arylene ether nitrile) (PEN)-based composites are prepared using the solution casting method. Composites with 30 wt% KH550@BT and 12 wt% BNNS were named as KH550@BT/BNNS/PEN. Composites with 30 wt% PDA@BT and 12 wt% BNNS were named as PDA@BT/BNNS/PEN. The microstructure, dielectric properties, and energy storage properties of the ternary composites were studied in detail. PEN embedded with either BNNS or BT were prepared and studied for comparison. As a result, the introduction of BT will improve the dielectric constant ( ε r ) and energy storage density ( W ), but it will reduce the breakdown strength ( E b ) and charge–discharge efficiency ( η ) of composites. BNNS not only improves E b and W but also improves η of composites. Although the introduction of BT and BNNS simultaneously may reduce η , it will improve ε r , E b , and W of composites. Most importantly, the fast discharge speed and high power density demonstrate that the BT/BNNS/PEN composites are potential candidates to be used in high power pulsed capacitors fields. Highlights Boron nitride nanosheets improve the breakdown strength of composites. The composites achieve simultaneous increment of ε r and E b . The power density of the BT/BNNS/PEN composites was higher than 70 MW cm −3 .