Improved thermal conductivity and breakdown strength of PVDF‐based composites by improving the dispersion of BN

Abstract

In order to adapt to the development of electronic devices, it is necessary to improve the thermal conductivity and breakdown strength of composites. Boron nitride (BN) is an ideal candidate material with high breakdown strength and thermal conductivity. Therefore, the introduction of BN nanosheets into the polyvinylidene fluoride (PVDF) matrix can improve the thermal conductivity and breakdown strength of the composites at the same time. However, BN nanosheets can easily agglomerate in the matrix, which limits the improvement of the properties of the composites. To overcome this difficulty, appropriate water‐bath heating was used to improve the fluidity of PVDF. Therefore, the dispersion of the filler is improved. When the volume fraction of BN nanosheets is 3% and the preparation temperature is 45°C, the energy storage density of the composites reached 18.5 J/cm3 at 540 kV/mm. At this point, the thermal conductivity was 0.49 W/(m⋅K), 3.5 times that of the pure PVDF film.

Energy Storage Capability of PVDF-Based Nanocomposites Significantly Enhanced by BaTiO3@BaxSr1–xTiO3 with Multi-Layer Gradient Core–Shell Structure Nanofillers

“…After studying the ferroelectric properties of nanocomposites, the ability of nanocomposites to withstand electric field was tested and analyzed. According to Formula P ( E ) = 1 − exp [ − ( E E b ) β ] where P (E) is the cumulative breakdown probability, E is the test breakdown strength, and β is a parameter representing the dispersion of breakdown strength values. Figure a gives the Weibull distribution of the breakdown strength of the nanocomposites.…”

Recent progress on dielectric polymers and composites for capacitive energy storage

“…PVDF/0.16 vol.% BNNS/PVDF [86] ~11.5 ~0.02 612 14.3 @ 612 MV/m 0.069 ~70 PVDF-BNNS/PVDF-BST/PVDF-BNNS [120] ~11.5 ~0.022 588 20.5 0.91 ~70 PVDF-BaTiO 3 [117] 12.5 0.03 390 16.5 @ 390 MV/m 65 16-layer P(VDF-HFP)-BaTiO 3 [112] ~1800 ~15 ~0.04 862.5 30.15 @ 782 MV/m 78 Gradient P(VDF-HFP)-BaTiO 3 [118] 1500 ~14 ~0.04 676.3 18.0 @ 670 MV/m 0.295 ~65 PVDF/PVDF-K 0.5 Na 0.5 NbO 3 /PVDF [122] ~11 <0.05 420 14.2 @ 420 MV/m 78.5…”

“…2D nanofillers, represented by boron nitride nanosheets, BNNSs, have been widely used to reduce the leakage current and improve breakdown strength [83][84][85][86][87][88][89] . To improve the dielectric constant, the BNNSs can be used in conjunction with a high-K nanofiller such as BT.…”

Large‐scale plasma grafts voltage stabilizer on hexagonal boron nitride for improving electrical insulation and thermal conductivity of epoxy composite

“…Unfortunately, their typical poor κ (less than 0.25 W/[m·K] [5–7]) has increasingly become a bottleneck towards further integration, so the synchronous improvement of E and κ of epoxy has become an urgent problem [8]. Ceramics, such as hexagonal boron nitride (hBN), generally have higher κ (more than 751 W/[m·K] [9, 10]) and sufficient E , and adding these fillers to the epoxy matrix is a theoretically good method to enhance the κ of epoxy. However, it is noted that the E of the composite attenuates seriously when the κ is obviously enhanced [11–13], which is mainly because the following problems have not been overcome: Doping of inorganic filler may lead to partial electric field distortion and degradation of E [14], which is not acceptable in commercial applications. The inherently high heterogeneous interfacial thermal resistance ( τ ) between nanoparticle fillers and polymer matrix (called Kapitza resistance [15]) makes the κ far less than the calculated value [16].…”