Largely enhanced dielectric properties of polymer composites with HfO2 nanoparticles for high-temperature film capacitors

• Published in: Composites science and technology 2021-01, Vol.201, p.108528, Article 108528
• Main Authors: Ren, Lulu, Yang, Lijun, Zhang, Siyu, Li, He, Zhou, Yao, Ai, Ding, Xie, Zongliang, Zhao, Xuetong, Peng, Zongren, Liao, Ruijin, Wang, Qing
• Format: Article
• Language: English
• Subjects: Dielectric properties; Dielectrics; Electric power systems; Energy storage; Flux density; Hafnium oxide; Hafnium oxide nanoparticles; High temperature; Leakage current; Nanocomposites; Nanoparticles; Permittivity; Polyetherimides; Polymer matrix composites; Polymer nanocomposites; Polymers
• ISSN: 0266-3538; 1879-1050
• DOI: 10.1016/j.compscitech.2020.108528

Polymer dielectrics are preferred materials for high-energy-density capacitive energy storage. In particular, high-temperature dielectrics that can withstand harsh conditions, e.g., ≥150 °C, is of crucial importance for advanced electronics and electrical power systems. Herein, high-temperature dielectric polymer composites composed of polyetherimide (PEI) matrix and hafnium oxide (HfO2) nanoparticles are presented. It is found that the incorporation of HfO2 with a moderate dielectric constant and a wide bandgap improves the dielectric constant and simultaneously reduces the high-field leakage current density of the PEI nanocomposites. As a result, the PEI/HfO2 composites exhibit superior energy storage performance to the current high-temperature engineering polymers at elevated temperatures. Specifically, the nanocomposite with 3 vol% HfO2 displays a discharged energy density of 2.82 J/cm3 at 150 °C, which is 77% higher than neat PEI. This work demonstrates the effectiveness of incorporation of the nanofiller with a medium dielectric constant into the polymer on the improvement of high-temperature capacitive properties of the polymer composites. [Display omitted]