Effect of Inorganic Nanoparticles on Energy‐Storage Properties of P(VDF–HFP)‐Based Nanocomposites

Abstract

Polyvinylidene fluoride (PVDF) and its copolymers have been widely used in polymer‐based film capacitors due to their relatively high permittivity and electrical displacement compared with other polymers. Herein, poly(vinylidene fluoride‐hexafluoropropylene) (P(VDF–HFP)) is selected as the polymer matrix, and 0.5 (Bi0.5Na0.5)TiO3–0.5(Sr0.85Sm0.1)TiO3 (BNT–SST) nanoparticles are added as the filler into the polymer to prepare BNT–SST/P(VDF–HFP) nanocomposites. The microstructure, electrical properties, mechanical properties, and energy‐storage properties of the nanocomposites are investigated. The addition of BNT–SST nanoparticles improves the dielectric characteristics and breakdown strength of the nanocomposites. Particularly, when the BNT–SST filler content is 0.7 vol%, the highest breakdown strength reaches 545 MV m−1, which is 1.3 times higher than pure P(VDF–HFP). In addition, the insulation and mechanical properties of BNT–SST/P(VDF–HFP) composite films are improved. The highest direct current resistivity and Young's modulus obtained by 0.7 vol% BNT–SST/P(VDF–HFP) nanocomposites are 6.8 × 1013 Ω cm and 1.94 GPa, respectively. More importantly, at 545 MV m−1, the energy‐storage density and efficiency of 0.7 vol% BNT–SST/P(VDF–HFP) composites are 19.07 J cm−2 and 67.01%, respectively, which are better than other polymer matrix composites. These findings suggest that the addition of inorganic nanoparticles has important research implications for improving the energy‐storage performance of polymer‐based film capacitors.