Ren Weibin, Tong Hui, Cao Shimo, Zhao Shuo, Yang Minzheng, Li Xin, Pan Jiayu, Sun Nannan, Xiao Yao, Xu Erxiang, Nan Ce-Wen, Shen Yang
State Key Laboratory of New Ceramic Materials, School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
State Key Laboratory of New Ceramic Materials, Beijing Tsinghua Institute for Frontier Interdisciplinary Innovation, Beijing, 102202, China.
Adv Mater. 2025 Jul 30:e05296. doi: 10.1002/adma.202505296.
Ultrahigh-power-density metallized film capacitors at elevated temperatures and electric field extremes are key components in electrical and electronic systems. The miniaturization, integration, and cost-effectiveness of the systems demand high-energy-density, high-efficiency, and reliable dielectrics. A major challenge is to concurrently break multiple paradoxes of bandgap (E) with glass transition temperature (T), dielectric constant (ɛ) with E and self-healing capability with T. In this contribution, a class of semi-alicyclic dipolar glass dielectric polymers (sAl-DG) is developed, with an alternating non-conjugated alicyclic unit and a strong dipolar group aromatic unit. The alicyclic unit synergistically confers a large E and the potential for strong self-healing while the other unit concurrently endows high polarization and thermal stability, effectively decoupling the multiple paradoxes. As a result, sAl-DG delivers large E with 3.99-4.26 eV, high T with 218-387 °C, high ɛ with 3.39-3.71 (200°C, 1 kHz) and simultaneously excellent self-healing ability with self-healing energy of 15.03 mJ. Hence, this molecular decoupling strategy enables a superior discharge energy density with 90% discharge efficiency (U) of up to 6.2 J cm at 200 °C, and state-of-the-art 3.94 J cm at 250 °C. Plus, a stacked sAl-DG capacitor demonstrates 1.06 J cm at 94% efficiency under 250 MV m and 200°C, showcasing operational viability.
在高温和极端电场条件下的超高功率密度金属化薄膜电容器是电气和电子系统中的关键部件。系统的小型化、集成化和成本效益要求有高能量密度、高效率和可靠的电介质。一个主要挑战是要同时打破带隙（E）与玻璃化转变温度（T）、介电常数（ɛ）与E以及自愈能力与T之间的多重矛盾关系。在本研究中，开发了一类半脂环族偶极玻璃电介质聚合物（sAl-DG），其具有交替的非共轭脂环族单元和强偶极基团芳香单元。脂环族单元协同赋予大的E值和强大的自愈潜力，而另一个单元则同时赋予高极化率和热稳定性，有效地解耦了多重矛盾关系。结果，sAl-DG具有3.99 - 4.26 eV的大E值、218 - 387 °C的高T值、3.39 - 3.71（200°C，1 kHz）的高ɛ值，同时具有15.03 mJ自愈能量的优异自愈能力。因此，这种分子解耦策略能够实现高达6.2 J/cm³的卓越放电能量密度，在200 °C时放电效率（U）为90%，在250 °C时达到3.94 J/cm³的先进水平。此外，一个堆叠式sAl-DG电容器在250 MV/m和200°C下以94%的效率展示了1.06 J/cm³的性能，证明了其实际应用的可行性。
