Improved dielectric and energy storage properties of polymer composites with BNNSs/AgNPs hybrid nanofiller

The development of polymer nanocomposites with superior dielectric performances is critical for flexible capacitive energy storage applications. However, the common approach to fabricate polymer composites with high-dielectric-constant ceramics as fillers always bring about exaggerate dielectric losses, hence low energy density and energy efficiency of polymer composites. In this work, BNNSs/AgNPs nanohybrids, where Ag nanoparticles were deposited on the surface of boron nitride nanosheets (BNNSs), are employed as fillers for poly(vinylidene fluoride-hexafluoropropylene) (PVDF-HFP) based nanocomposites. The contributions by enhanced interface polarisation and the internal barrier layer capacitor (IBLC) effect generated by the uniform distribution of conductive Ag nanoparticles on the insulative BNNSs, result in a large increase in dielectric constant and electric displacement meanwhile simultaneously suppressed dielectric losses. The BNNSs/AgNPs/PVDF-HFP nanocomposites exhibit much higher energy density and energy efficiency than the pristine PVDF-HFP and the BNNSs/PVDF-HFP composites counterparts, being great potential for dielectric energy storage applications.