Polymer dielectric composites are of considerable interest for film capacitors that are widely used in modern electric devices and electric power systems. However, the adverse coupling between dielectric permittivity (ε_r) and breakdown strength (E_b) makes it difficult to obtain high energy densities in natural materials. With the aim of achieving concurrently improved ε_r and E_b, a class of rationally designed layer-structured composites consisting of pure poly(vinylidene fluoride–hexafluoropropylene) (P(VDF–HFP)) layers and barium titanate/P(VDF–HFP) (BT/P(VDF–HFP)) composite layers were prepared. Interestingly, the layer-structured composites exhibit a concurrent improvement of ε_r and E_b. The 4-layer composite with 15 vol% BT exhibits substantially enhanced ε_r and E_b which are nearly ∼186% and ∼248% of those for its 1-layer counterpart, respectively. Consequently, a high energy density of ∼4 J cm⁻³ along with a satisfactory efficiency of 71% at 240 kV mm⁻¹ is achieved. Meanwhile, a low loss tangent of ∼0.05 at 10 kHz which is comparable to that of pure P(VDF–HFP) is maintained. This work shows that the adverse coupling between ε_r and E_b in dielectric materials could be well addressed by constructing nanocomposites with layered rather than random distribution of fillers.

中文翻译：

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层状结构的BaTiO3 / P（VD​​F–HFP）复合材料，同时提高了介电常数和击穿强度，适用于电容储能

聚合物电介质复合材料对于广泛用于现代电气设备和电力系统中的薄膜电容器具有重大意义。但是，介电常数（之间的不良耦合ε _{- [R} ）和击穿强度（Ë _b）使得它难以得到天然材料的高能量密度。与实现同时提高的目的ε _{- [R}和Ë _b，一类由纯聚的合理设计的层构造的复合材料（偏二氟乙烯-六氟丙烯）（P（VDF-HFP））层和钛酸钡/ P（VDF-HFP ）（BT / P（VD​​F-HFP））复合层已准备好。有趣的是，层状复合材料同时显示出ε _{- [R}和Ë _b。用15体积％BT 4层复合材料表现出显着增强ε _{- [R}和Ë _b分别是近~186％和那些其1层对应的~248％。因此，获得了约4 J cm ^-3的高能量密度以及240 kV mm ^-1时的71％的令人满意的效率。同时，保持了与纯P（VDF-HFP）相当的10 kHz低损耗正切值。这项工作表明，之间的不良耦合ε _{- [R}和Ë _b 通过构建具有分层而不是随机分布的填料的纳米复合材料，可以很好地解决介电材料中的“纳米粒子”问题。