Tailoring dielectric performance via dipole density and hydrogen bonding interaction towards high-temperature capacitive energy storage polymers

Abstract

In addressing the critical demand for high-performance dielectric materials in advanced energy storage systems at elevated temperatures, this study introduces a molecular engineering strategy integrating copolymerization and polymer blending to optimize dipolar polarization in polyurea-based dielectrics. By systematically modulating the intrinsic molar polarizability through controlled incorporation of small molar volume m-phenylenediamine, here we constructed a novel high dipole density co-polyurea with an enhanced dielectric constant. Blending this co-polyurea with polyetherimide disrupted intermolecular hydrogen bonding partially, enhancing free volume and dipole mobility and thus increasing orientational polarizability. Experimental characterization revealed that the 1 : 1 blend exhibited a remarkably increase in the dielectric constant (7.13), more than twice that of PEI, alongside low dielectric loss (0.0084), high breakdown strength (550 MV m−1) and exceptional dielectric thermal stability up to 150 °C. In addition, the polymer blend demonstrated a higher breakdown strength and a lower leakage current density compared to PEI. These properties enabled a discharged energy density of 4.6 J cm−3 with over 90% charge–discharge efficiency at 150 °C and 400 MV m−1, surpassing conventional high-temperature dielectrics. This work establishes a scalable approach to balance dipolar density and dipolar mobility in polar polymers through copolymerization and blending, offering transformative insights for next-generation dielectric capacitors in high-temperature environments.

Graphical abstract: Tailoring dielectric performance via dipole density and hydrogen bonding interaction towards high-temperature capacitive energy storage polymers

Supplementary files

Article information

Article type
Paper
Submitted
22 May 2025
Accepted
23 Jun 2025
First published
25 Jun 2025

J. Mater. Chem. A, 2025, Advance Article

Tailoring dielectric performance via dipole density and hydrogen bonding interaction towards high-temperature capacitive energy storage polymers

F. Zhou, C. Tian, L. Huang, Y. Jiang, F. Zhao, N. Yang, D. Yuan and X. Cai, J. Mater. Chem. A, 2025, Advance Article , DOI: 10.1039/D5TA04136H

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