Dai Zhizhan, Jia Jiangheng, Ding Song, Wang Yiwei, Meng Xiangsen, Bao Zhiwei, Yu Shuhong, Shen Shengchun, Yin Yuewei, Li Xiaoguang
Hefei National Research Center for Physical Sciences at the Microscale, Department of Physics, and CAS Key Laboratory of Strongly Coupled Quantum Matter Physics, University of Science and Technology of China, Hefei 230026, China.
Department of Chemistry, Institute of Biomimetic Materials and Chemistry, Anhui Engineering Laboratory of Biomimetic Materials, Hefei National Research Center for Physical Sciences at the Microscale, University of Science and Technology of China, Hefei 230026, China.
ACS Appl Mater Interfaces. 2024 Mar 13;16(10):12865-12872. doi: 10.1021/acsami.3c18237. Epub 2024 Feb 28.
The commercial capacitor using dielectric biaxially oriented polypropylene (BOPP) can work effectively only at low temperatures (less than 105 °C). Polyphenylene oxide (PPO), with better heat resistance and a higher dielectric constant, is promising for capacitors operating at elevated temperatures, but its charge-discharge efficiency (η) degrades greatly under high fields at 125 °C. Here, SiO layers are magnetron sputtered on both sides of the PPO film, forming a composite material of SiO/PPO/SiO. Due to the wide bandgap and high Young's modulus of SiO, the breakdown strength () of this composite material reaches 552 MV/m at 125 °C (PPO: 534 MV/m), and the discharged energy density () under improves to 3.5 J/cm (PPO: 2.5 J/cm), with a significantly enhanced η of 89% (PPO: 70%). Furthermore, SiO/PPO/SiO can discharge a of 0.45 J/cm with an η of 97% at 125 °C under 200 MV/m (working condition in hybrid electric vehicles) for 20,000 cycles, and this value is higher than the energy density (∼0.39 J/cm under 200 MV/m) of BOPP at room temperature. Interestingly, the metalized SiO/PPO/SiO film exhibits valuable self-healing behavior. These results make PPO-based dielectrics promising for high-temperature capacitor applications.
使用双轴取向聚丙烯（BOPP）电介质的商用电容器仅在低温（低于105°C）下才能有效工作。聚苯醚（PPO）具有更好的耐热性和更高的介电常数，有望用于高温下工作的电容器，但其在125°C的高电场下充放电效率（η）会大幅下降。在此，通过磁控溅射在PPO薄膜两侧沉积SiO层，形成SiO/PPO/SiO复合材料。由于SiO的宽带隙和高杨氏模量，该复合材料在125°C时的击穿强度（）达到552 MV/m（PPO：534 MV/m），在 下的放电能量密度（）提高到3.5 J/cm³（PPO：2.5 J/cm³），η显著提高至89%（PPO：70%）。此外，在200 MV/m（混合动力汽车的工作条件）下，SiO/PPO/SiO在125°C时可以进行20000次循环，放电能量密度为0.45 J/cm³，η为97%，该值高于室温下BOPP的能量密度（在200 MV/m下约为0.39 J/cm³）。有趣的是，金属化的SiO/PPO/SiO薄膜表现出有价值的自愈行为。这些结果使得基于PPO的电介质在高温电容器应用方面具有广阔前景。
