2026/01/01 by Jinglong Hu, Minjiang Liu, Yuxin Xia +2 · 1 voice
Engineering · Materials Science · #Dielectric materials and actuators #High voltage insulation and dielectric phenomena #Synthesis and properties of polymers
paper · doi:10.1515/epoly-2025-0052
openalex publication_date 2026/01/01 · openalex created_date 2026/02/17 · openalex updated_date 2026/06/11
Abstract Polymer dielectric films have extensive applications in power systems, pulse power systems, hybrid vehicles, and clean energy. However, with advancements in energy storage technology and increasingly demanding operating environments, particularly under high-temperature conditions, their utility is constrained by the low dielectric constant and significantly increased leakage current density at high temperatures. Polyimide (PI), an excellent high-temperature-resistant polymer, has gained prominence in high-temperature energy storage. In this work, a high-dielectric polyimide incorporating high-polarity sulfonyl groups was synthesized via an in-situ polymerization approach. Furthermore, alicyclic structures are introduced to reduce leakage current, enhance breakdown strength, and ultimately improve energy storage density. At 150 °C and 600 MV/m, a discharge energy density of 3.25 J/cm 3 is achieved, alongside a breakdown strength of 650 MV/m. This work presents a polymer dielectric for high-temperature capacitors and provides a basis for subsequent modification in the future.