High‐temperature polymer dielectrics are in great demand for harsh‐environment applications. Maintaining high‐energy storage density and low loss at elevated temperatures remains a major challenge for polymer dielectrics. In this work, a new type of polymer dielectric material is designed, which exhibits comparable dielectric properties in the start‐of‐the‐art dielectric nanocomposites and a superior potential for scale up. A soluble, glassy state polymer with a polarizing group is designed by introducing a weakly polar group into the polyaramid (PA) backbone to dilute the hydrogen bonding of the PA parent species. This increases the mobility of the molecular dipole within the polymer in the glassy state, thereby increasing its dielectric constant while maintaining the high‐temperature performance. The result of this design is a polymer with a glass transition temperature of 251 °C, a dielectric constant of up to 4.5, and a dielectric loss of 1%, while maintaining 2.1 J cm⁻³ energy density and 86.8% efficiency at 200 °C. This polymer, with its excellent, intrinsic, electrical‐energy‐storage properties can also be adapted for a roll‐to‐roll capacitor film production. Breaking intermolecular hydrogen bonds to enhance the electrical‐energy‐storage properties of polymers is an excellent path for designing polymer dielectrics with high‐temperature capabilities.

中文翻译：

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高温下高效储能电介质中可溶性聚芳纶的合理设计

高温聚合物电介质对恶劣环境的应用需求很大。在高温下保持高能量存储密度和低损耗仍然是聚合物电介质的主要挑战。在这项工作中，设计了一种新型的聚合物介电材料，该材料在最先进的介电纳米复合材料中显示出可比的介电性能，并且具有极高的放大潜力。通过将弱极性基团引入聚芳酰胺（PA）骨架中以稀释PA母体物种的氢键，可以设计出具有极性基团的可溶性玻璃态聚合物。这增加了处于玻璃态的聚合物中分子偶极子的迁移率，从而在保持高温性能的同时提高了其介电常数。能量密度为^-3，在200°C时效率为86.8％。这种聚合物具有出色的固有的电能存储特性，也可以用于卷对卷电容器膜的生产。断裂分子间氢键以增强聚合物的电能存储特性是设计具有高温性能的聚合物电介质的绝佳途径。