Improved Energy Density Obtained in Trilayered Poly(vinylidene fluoride)-Based Composites by Introducing Two-Dimensional BN and TiO₂ Nanosheets

Abstract

Dielectric capacitors with an ultrahigh power density have received extensive attention due to their potential applications in advanced electronic devices. However, their inherent low energy density restricts their application for miniaturization and integration of advanced dielectric capacitors. Herein, a novel composite entirely incorporated with two-dimensional (2D) nanosheets with a topological trilayered construction is prepared by a solution casting and hot-pressing method. The 2D boron nitride nanosheets (BNNS) with a wide band gap that are oriented in a poly(vinylidene fluoride) (PVDF) matrix to form the upper and bottom outer layers would efficiently suppress the leakage current in composites, thus significantly improving the overall breakdown strength. Meanwhile, the 2D anatase-type TiO 2 nanosheets (TONS) uniformly distributed in the middle layer can enhance their interfacial compatibility and polarization with the PVDF matrix, leading to a synergistic improvement in both the breakdown strength and dielectric constant of the composite. In particular, a significantly improved dielectric constant of ∼11.42, a reduced dielectric loss of 0.03 at 100 Hz, and a maximum discharge energy density (U dis ) of 10.17 J cm −3 at an electric field of 370.1 MV m −1 can be obtained from the trilayered composite containing 3 wt % 2D TONS in the middle layer and 2 wt % 2D BNNS on the outer layer. The finding of this research offers an effective strategy for the preparation of advanced polymer-based composites with an outstanding discharge energy density performance.

Achieving Higher Dielectric and Energy Storage Performances of Methyl Methacrylate-co-glycidyl Methacrylate Films through the Nanocomposite Strategy

“…Therefore, the increase of the modulus is beneficial for improving the breakdown strength and energy storage capacity. As shown in Figure c, with the addition of OMMT, the modulus of the nanocomposite films is gradually increased from 2210 MPa of pure MG to 2840 MPa of 1.2 MG/OMMT, which has a positive contribution to improving the breakdown strength of the MG/OMMT films. − ,− …”

Improved energy storage properties of polypropylene-based composite dielectrics by introducing surface-charged BaTiO3@chitisan ultrafine constructions

“…Additionally, under a common electric field, the composites filled with more BaTiO 3 @CS could achieve higher U e values, which is mainly due to the synergetic effect of enhanced E b , D max and D max À D r values. 50 The neat PP shows its highest U e of 1.77 J cm À3 at an E b of 451 MV m À1 . However, under the same electric field, the 0.2 vol% BaTiO 3 @CS/PP composite displays a significantly enhanced U e of 2.93 J cm À3 .…”

Synergistic Effect of Al2O3@BaTiO3–BNNSs Hybrid Fillers for Improved Energy Storage and Thermal Conductivity Properties of PVDF-Based Composites

“…21−23 Moreover, the large bandgap of BNNSs would help to reduce conduction loss, which benefits the insulation properties of the composites. 24,25 Wang et al introduced BNNSs into PVDF matrix, and a U d of 18.5 J/cm 3 at 540 kV/mm was obtained at 3 vol % BNNSs, approximately 2.5 times over the value of pristine PVDF. Also, the thermal conductivity increases to 0.49 W/(m•K), but the dielectric constant at 100 Hz decreases from ∼11 of PVDF to 9 of 3 vol % BNNSs/PVDF.…”

“…Hexagonal boron nitride nanosheets (BNNSs) have high thermal conductivity and two-dimensional structures, making them promising fillers for constructing a high-efficiency thermal conductive network inside the composites. − Moreover, the large bandgap of BNNSs would help to reduce conduction loss, which benefits the insulation properties of the composites. , Wang et al introduced BNNSs into PVDF matrix, and a U d of 18.5 J/cm 3 at 540 kV/mm was obtained at 3 vol % BNNSs, approximately 2.5 times over the value of pristine PVDF. Also, the thermal conductivity increases to 0.49 W/(m·K), but the dielectric constant at 100 Hz decreases from ∼11 of PVDF to 9 of 3 vol % BNNSs/PVDF …”