Effects of the Particle Size of BaTiO₃ Fillers on Fabrication and Dielectric Properties of BaTiO₃/Polymer/Al Films for Capacitor Energy-Storage Application.

BaTiO₃/polymer/Al (BPA) composite films for energy storage were fabricated by way of a roll coating and thermal curing process. The coating slurry consisted of silicon-containing heat-resistant resin (CYN-01) and BaTiO₃ particles with various particle sizes obtained from commercial BaTiO₃ powders processed at different durations of wet sand grinding in the presence of silane coupling agent (KH550), which not only improves the dielectric performance of the BPA films but also facilitates its production in a large scale. The major influence factors, such as the ratio between BaTiO₃ and resin and the size of BaTiO₃ particles, were investigated and their related mechanisms were discussed. The results show that modifying BaTiO₃ particles ( = 0.83 μm) with the silane coupling agent of KH550 enhances the dielectric properties of the BPA films. The typical BPA films obtained exhibit a high dielectric constant of 32, a high break strength of 20.8 V/μm and a low dielectric loss of 0.014. The present work provides a simple and convenient way to prepare high-quality ceramic/polymer composite films for energy-storage application in a large scale.