Frequency, temperature, and strain effects on dielectric tunability and energy storage performance of P(VDF-TrFE-CFE) terpolymer

In this study, the dielectric and ferroelectric responses of P(VDF-TrFE-CFE) terpolymer were systematically investigated under various DC electric fields, frequencies, temperatures, and mechanical strains. The dielectric constant exhibited pronounced decrease at low frequencies under the influence of DC bias. This effect was particularly evident at temperatures where dielectric dispersion was significant. These results indicate that the dynamics of polar nanoregions are of critical importance in both high dielectric tunability (67% at 100 MV/m) and frequency-dependent dielectric behavior. The polarization-electric field hysteresis loops became increasingly slim at elevated temperatures and at high frequencies. These results indicate that the thermal activation and dynamic behavior of polar nanoregions significantly influence the high discharged energy density (3.8 J/cm³ at 200 MV/m) and storage efficiency (65% at 10² Hz and 300 K). Additionally, the inherent mechanical flexibility of the P(VDF-TrFE-CFE) film leads to highly stable dielectric and ferroelectric properties under compressive/tensile strains and after extensive bending cycles. This work demonstrates that the control of polar nanodomains is a key strategy to enhance the dielectric tunability and energy storage performance of P(VDF-TrFE-CFE) terpolymers for portable and wearable electronics applications.