The electrocaloric effect of PBZ/PVDF flexible composite film near room temperature

Pb_0.8Ba_0.2ZrO₃ (PBZ) nanofibers were prepared through electrospinning and mixed at a volume composite ratio of 0–6% with polyvinylidene fluoride (PVDF) dissolved in an organic solvent, and the PBZ/PVDF composite film was prepared through casting. The nanocomposites with PBZ nanofibers of 3 vol% showed the best ferroelectric performance in this work, and the maximum polarization value and breakdown field strength were 9.69 μC/cm² and 420 MV/m, respectively. The dielectric constant and dielectric loss at a depolarization temperature of 285 K were 6.13 and 0.21, respectively. The performance of the electrocaloric effect was studied using the direct method near room temperature. Under 150 MV/m and − 30 °C, the △T and ΔS of the composite film were 13.99 K and 52.70 J/kg K, respectively. When the temperature increased to 70 °C, △T and ΔS become 5.08 K and 13.56 J/kg K, respectively. The simulation results and experiments indicate that the incorporation of nanofibers can increase the interface polarization with higher polarization value and improve the ferroelectric performance than pure PVDF.