Improved energy storage performances of P(VDF-HFP)/BNNSs composite: Role of nanosecond electric pulse

Polymer-based dielectric films with excellent physicochemical and electrical properties are widely designed for energy storage applications of electrostatic capacitors. In this work, the energy storage capabilities of the poly(vinylidene fluoride-co-hexafluoropropylene)/boron nitride nanosheets (P(VDF-HFP)/BNNSs) composites were manipulated via a self-made nanosecond electric pulse (nsEP) assisted solution-casting platform. The nsEP induces dipole interactions and dielectrophoretic forces, achieving a high horizontal orientation degree (∼78 %) of BNNSs within the composite. Experimental and simulation results demonstrate that this reorientation of BNNSs alleviates electric field distortion at the BNNSs/polymer matrix interface, suppresses the electron propagation path, and significantly improves dielectric properties, breakdown field, and energy density. Specifically, under the nsEP of 80 V/mm, the P(VDF-HFP)/BNNSs composite presents an elevated breakdown field of 521 MV/m and an improved energy density of 10.3 J/cm ³, which are 9.5 % and 40.1 % enhancement in comparison to the untreated samples. This work introduces an innovative approach to fabricate P(VDF-HFP)/BNNSs composites, and provides a new route on the improvement of high-energy-density PVDF-based films.