Effects of Y2O3/ZrO2 Particles on Dielectric Properties and Voltage Resistance of Polyimide Films

With the advancement of energy storage technology, there have been significantly increased demands for the storage performance and operating temperature of capacitor dielectric materials. As a high-temperature resistant polymer, polyimide (PI) shows great potential for application as a dielectric material. In this study, binary PI composite films with various contents of yttria-stabilized zirconia particles (YZPs) were prepared via in situ polymerization. The results demonstrated that the incorporation of YZPs enhanced the breakdown resistance compared to pure PI films. Specifically, at a YZP content of 8 wt%, the breakdown strength (BDS) of the composite films reached 566 kV·mm−1. Although the mechanical strength exhibited a slight reduction, the dielectric properties remained stable, leading to an overall improvement in energy storage performance. Overall, 2 wt% YZPs/PI (with 5 mol% Y2O3, ZPb2) film is optimal in terms of its mechanical and dielectric properties. This research establishes a solid foundation for the engineering development and industrial implementation of high-performance PI-based polymer dielectric materials.