Rigid short-chain cross-linking networks for high energy density and improved charge–discharge efficiency in fluoropolymer ferroelectrics

Abstract

Ferroelectric polymers have emerged as promising dielectric materials for film capacitors in modern electronics and high-power systems, owing to their high dielectric constant. However, their practical applications are limited by significant energy loss caused by ferroelectric hysteresis, which leads to poor charge–discharge efficiency under high electric fields. To overcome this challenge, we developed a ferroelectric polymer incorporating rigid short-chain cross-linked networks that simultaneously facilitate weakly polar γ-phase formation and restrict chain motion to minimize dielectric loss. These networks further introduce deep charge traps that effectively suppress leakage current and conduction loss while significantly enhancing breakdown strength. These optimal characteristics collectively contribute to enhancements in both discharged energy density and charge–discharge efficiency. Notably, the rigid short-chain cross-linked networks are formed through thermally initiated imine bond formation between the ferroelectric polymer and 4,4′-diaminodiphenyl ether (ODA) serving as a rigid diamine crosslinker via a simple heating process. This methodology combines processing simplicity with excellent scalability, positioning it as a highly promising solution for manufacturing high-performance energy storage capacitors.