Effects of heat treatment on the dielectric and energy storage properties of BT‐PVDF nanocomposite films

Abstract Ceramic‐polymer nanocomposites exhibit good dielectric constant, low dielectric loss and excellent storage capacity for energy. A spin‐coating method was used to create 30 vol% BaTiO 3 (BT) nanoparticles and polyvinylidene fluoride (PVDF) nanocomposite films with a homogeneous thickness of around 7 μm. The findings indicated that, with increasing the quenching temperature, the dielectric constant of the nanocomposite films decreased at 100 Hz. The dielectric constant of the BT‐PVDF nanocomposite film was 75.4 after quenched in air at 100°C, which was 21.4% greater than the that of the unquenched film. The breakdown strength of the films increased with increasing quenching temperature and reached the maximum values of 1400 kV/cm and 1600 kV/cm at 160°C, respectively. The breakdown strength of the film quenched in liquid nitrogen reached a maximum of 1600 kV/cm at 140°C. With increasing of quenching temperature, the charging density of BT‐PVDF nanocomposite film increased first and then decreases, reaching the maximum value of 11.165 J/cm 3 at 140°C, which was 146% higher than that of the unquenched film. Heat treatment will be an innovative method for improving the dielectric and energy‐storage capabilities of ceramic‐polymer nanocomposite films. Highlights The uniform thickness of the film prepared by spin‐coating was about 7 μm. The dielectric properties of the composite film after quenching processes were improved. The breakdown voltage and charging density were vastly enhanced after quenching processes.