Enhanced breakdown strength and reduced polarization hysteresis in relaxor ferroelectric polymers with increased gamma phase content for energy storage capacitors

Polymer dielectric energy storage capacitors play a vital role in modern electronic and electrical power systems, particularly in high-voltage environments. However, achieving both high energy density and charge–discharge efficiency presents a significant challenge for next-generation applications that demand miniaturization and compact design. In this study, we present relaxor ferroelectric terpolymers with an increased gamma (γ)-phase content, prepared through a facile and scalable interfacial engineering approach that incorporates ultra-low amounts of graphene oxide. The γ-phase crystals in the terpolymer reduce hysteresis losses and generate numerous deep traps, resulting in enhanced performance. These terpolymers achieve a high energy density of up to 15.2 J/cm3 and an improved breakdown strength of 562 MV/m, representing enhancements of 62% and 39.8%, respectively, compared to the pristine terpolymer. The results suggest that tuning the phase structure of relaxor ferroelectric terpolymers offers a pathway to developing ferroelectric polymers with enhanced energy density and charge–discharge efficiency for energy storage capacitors.