聚酰亚胺
材料科学
脂环化合物
电介质
聚合物
复合材料
电容器
介电强度
高分子化学
电压
光电子学
电气工程
图层(电子)
工程类
作者
Wenjie Huang,Baoquan Wan,Xing Yang,Meng Cheng,Yiyi Zhang,Yuchao Li,Chao Wu,Zhi‐Min Dang,Jun‐Wei Zha
标识
DOI:10.1002/adma.202410927
摘要
Abstract Polymer dielectrics with combined thermal stability and self‐healing properties are specifically desired for high‐temperature film capacitors. The high thermal stability of conventional polymers benefits from the abundance of aromatic rings in the molecule backbone, but the high carbon content sacrifices their self‐healing properties. Here, analicyclic polyimide with a high glass transition temperature (256 °C) and wide energy bandgap (4.58 eV) is designed, which exhibits electric conductivity more than an order of magnitude lower than that of classical polyimide at high electric fields and high temperatures. As a result, alicyclic polyimide achieves a discharged energy density of 4.54 J cm −3 and a charge‐discharge efficiency of above 90% at 200 °C, which is superior to existing dielectric polymers and composites. The alicyclic polyimide benefits from a low pyrolytic residual carbon rate, retaining 93% of the dielectric breakdown strength after four electrical breakdown cycles. Distinguishing from the current condensed‐phase self‐healing concept, for the first time, exploring the self‐healing capability of high‐temperature polyimide dielectric is presented based on dual self‐healing mechanisms of gas‐phase and condensed‐phase. The high energy density at high temperatures and the superior self‐healing capability of alicyclic polyimide further indicate the promise of polyimide dielectric film capacitors for extreme conditions.
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