Abstract Dielectric materials with ultrahigh energy densities are of importance in modern electric industry. However, for dielectric nanocomposites, their ultrahigh energy densities were typically achieved at the expense of low charge-discharge efficiencies (η) of 60%–70% at high electric fields, which is not desirable for practical applications. In this study, a class of newly designed sandwiched polymer nanocomposites based on poly(methyl methacrylate) (PMMA) as the central layer to enhance the breakdown strength and charge-discharge efficiency and poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) loaded BaTiO3 nanoparticles (BT NPs) as the outer layers to boost the polarization. It is found that the sandwiched nanocomposite with 10 wt% BT NPs in the outer layers possesses a largely enhanced energy density of 17.1 J cm−3 with a high η of 82% at the Weibull breakdown strength of 559 MV m−1. To our knowledge, this is one of the highest η achieved at high electric fields among the dielectric nanocomposites reported so far. This work demonstrates the uniqueness of the trilayered structure to incorporate multiple components and display much enhanced collective properties for energy applications.

中文翻译：

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具有聚甲基丙烯酸甲酯层的夹心聚合物纳米复合材料的超高充放电效率和增强的能量密度

摘要 具有超高能量密度的介电材料在现代电气工业中具有重要意义。然而，对于介电纳米复合材料，它们的超高能量密度通常是以在高电场下 60%–70% 的低充放电效率 (η) 为代价来实现的，这对于实际应用来说是不可取的。在这项研究中，一类新设计的夹层聚合物纳米复合材料基于聚（甲基丙烯酸甲酯）（PMMA）作为中心层，以提高击穿强度和充放电效率和聚（偏二氟乙烯-共-六氟丙烯）（PVDF-HFP） ) 加载 BaTiO3 纳米粒子 (BT NPs) 作为外层以增强极化。结果表明，外层含有 10 wt% BT NPs 的夹心纳米复合材料的能量密度大大提高，为 17。1 J cm-3 在威布尔击穿强度为 559 MV m-1 时具有 82% 的高 η。据我们所知，这是迄今为止报道的介电纳米复合材料中在高电场下达到的最高 η 之一。这项工作证明了三层结构的独特性，它结合了多种成分，并为能源应用展示了大大增强的集体特性。