Enhanced dielectric properties and discharged energy density of composite films using submicron PZT particles

Flexible dielectric composite films are highly desirable materials with potential application in capacitors due to their high energy density and discharged efficiency. However, agglomeration induced by the large surface energy of nanoparticles and their large dielectric losses are unfavorable to the improvement of energy density. Submicron lead zirconate titanate (PZT) particles have shown great potential as filler in achieving a high energy storage capacity because of their excellent dielectric properties and good dispersion. In this work, calcined PZT particles were used to prepare PZT/polyvinylidene fluoride (PVDF) composite films. The results showed that composite films of high quality could be obtained even with high contents of submicron PZT particles. The introduction of PZT particles significantly improved the dielectric performance of composite films compared with that of the pristine PVDF film. The discharged energy density of composite films with 10 vol% PZT particles achieved 6.41 J/cm3 at 250 kV/mm. A high efficiency of 87.25% was obtained at 50 kV/mm. These findings confirm the feasibility of PZT particles as inorganic filler in composite films for energy storage applications.