Hao Jing, Mutegi Irene, Mukherjee Madhubanti, Sahu Harikrishna, Khomane Ashish, Yassin Omer, Ramprasad Rampi, Sotzing Gregory A, Cao Yang
Electrical Insulation Research Center, Institute of Materials Science, University of Connecticut, Storrs, CT 06269.
Institute of Materials Science, University of Connecticut, Storrs, CT 06269.
Proc Natl Acad Sci U S A. 2024 Dec 10;121(50):e2415388121. doi: 10.1073/pnas.2415388121. Epub 2024 Dec 6.
Polymer film dielectrics are highly favored for capacitive energy storage due to the inherent advantages of high breakdown strength, low dielectric loss, and ease of processing. High-density renewables conversion and harsh-condition electrification further emphasize the need for high-temperature, high-k polymers. A unique design strategy is developed to augment high-temperature polyolefins with improved dielectric constant, via the integration of phenyl pendants hanging off the rigid bicyclic backbone. The impacts of the pendant polarizability and steric positioning on dielectric constant, bandgap, glass-transition temperature (), and high-field, high-temperature dielectric characteristics have been investigated. The orientational polarization of the polar phenyl pendants with rotational degree of freedom imparts cyclic olefins with enhanced dielectric constants, while maintaining the large bandgap, and high glass-transition temperature ( > 170 °C). Among these synthesized polymers, m-PNB-BP stands out with a remarkable dielectric constant of 4 at a high sub- temperature of 150 °C, and a high discharged density of 8.6 J/m at 660 MV/m. This study unveils a different path for designing high-temperature polymers with enhanced dielectric constants, particularly beneficial for capacitive energy storage.
聚合物薄膜电介质因其具有高击穿强度、低介电损耗和易于加工等固有优点，在电容式能量存储方面备受青睐。高密度可再生能源转换和恶劣条件下的电气化进一步凸显了对高温、高介电常数聚合物的需求。通过将悬挂在刚性双环主链上的苯基侧基相结合，开发了一种独特的设计策略来增强高温聚烯烃的介电常数。研究了侧基极化率和空间位置对介电常数、带隙、玻璃化转变温度（）以及高场、高温介电特性的影响。具有旋转自由度的极性苯基侧基的取向极化赋予环烯烃更高的介电常数，同时保持较大的带隙和较高的玻璃化转变温度（>170°C）。在这些合成聚合物中，间位硝基苯并菲基双环戊二烯（m-PNB-BP）表现突出，在150°C的高温下具有4的显著介电常数，在电场强度为660 MV/m时具有8.6 J/m的高放电能量密度。这项研究为设计具有增强介电常数的高温聚合物开辟了一条不同的途径，这对电容式能量存储特别有益。
