Improved capacitive energy storage capability of P(VDF-HFP) nanocomposites enabled by cost-effective and ergodic relaxor phase dominant nanofillers

Polymer-based dielectrics with excellent processability are essential for dielectric capacitors applications in modern electronics and electrical power systems. Although significant advances in capacitive storage have been achieved by adding inorganic fillers that are synthesized primarily by liquid-phase technology, this method faces considerable challenges for the industrial production of scalable capacitor films that requires easy process conditions. Herein, P(VDF-HFP) nanocomposites with cost-effective inorganic 0.7[0.955(Bi0.5Na0.5)TiO3-0.045Ba(Al0.5Ta0.5)O3]-0.3CaTiO3 nanoparticles (BNT-BAT-CT nps) that are prepared by a combination of solid phase approach and sieving, are constructed via a scalable and practical mechanical process. Both experimental and simulation results verify that the appropriate BNT-BAT-CT nps can significantly suppress the leakage current density, improve the dielectric constant, and block the penetration of the electrical tree, thus generating substantial enhancements in the breakdown strength and capacitive performance. A large discharge energy density (∼10.82 J/cm3) is realized at 580 MV/m in 3 vol% BNT-BAT-CT/P(VDF-HFP) nanocomposites, which is approximately 2.17 times larger than that of pristine P(VDF-HFP). More significantly, unlike previous polymer nanocomposites incorporated with high-cost nanofillers, the designed nanocomposites contain low preparation cost of nanofillers. Combined with the merits of high energy-storage performance and simple and cost-effective preparation, this work offers a viable method towards the large-scale production of polymer-based high-performance dielectrics.