High-temperature polymer nanocomposites with high energy storage density () are promising dielectrics for capacitors used in electric vehicles, aerospace, etc. However, filler agglomeration and interface defects at high filler loadings significantly limit the enhancement of and hamper the large-scale production of the nanocomposites. Here, polyetherimide (PEI) nanocomposites with nanoscale alumina (AO) at ultra-low contents were prepared polymerization from PEI monomers. We compared two composite dielectric preparation methods ( polymerization and ordinary solution blending) under the same conditions. In contrast to the nanocomposites obtained by blending PEI polymers with AO, the nanocomposites exhibit substantially improved filler dispersion, together with largely suppressed conduction loss at high fields and high temperatures, leading to comprehensive enhancements of breakdown strength (), charge-discharge efficiency () and , simultaneously. The 0.3%(in volume) AO filled PEI nanocomposite film exhibits a superior of 4.8 J/cm with of 90% at 150 °C, which is 128% and 218% higher than those of pristine PEI and the PEI/AO nanocomposite film under the same conditions, respectively. This work provides a scalable strategy for the preparation of dielectrics with both good processability and excellent high-temperature energy storage performance.

中文翻译：

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原位聚合聚醚酰亚胺/Al2O3纳米复合材料在高温下显着改善电容储能性能

具有高能量存储密度的高温聚合物纳米复合材料是用于电动汽车、航空航天等领域的电容器的有前景的电介质。然而，高填充量下的填料团聚和界面缺陷严重限制了其增强并阻碍了大规模生产。纳米复合材料。在这里，由PEI单体聚合制备了具有超低含量纳米级氧化铝（AO）的聚醚酰亚胺（PEI）纳米复合材料。我们在相同条件下比较了两种复合电介质的制备方法（聚合法和普通溶液共混法）。与 PEI 聚合物与 AO 共混获得的纳米复合材料相比，纳米复合材料表现出显着改善的填料分散性，同时大大抑制了高场和高温下的传导损耗，从而全面提高了击穿强度 ()、充放电效率 ()和 ，同时。0.3％（体积）AO填充的PEI纳米复合薄膜在150℃下表现出4.8J/cm的优越性和90％的性能，比原始PEI和在150℃下的PEI/AO纳米复合薄膜高128％和218％分别是相同的条件。这项工作为制备具有良好加工性能和优异高温储能性能的电介质提供了一种可扩展的策略。