Composite Based on Fe3O4@BaTiO3 Particles and Polyvinylidene Fluoride with Excellent Dielectric Properties and High Energy Density

To obtain the dielectric material with high dielectric constant and high breakdown field, here a new composite material based on Fe 3 O 4 @BaTiO 3 shell–core particles and polyvinylidene fluoride (PVDF) has been prepared. It is proved the Fe 3 O 4 @BaTiO 3 particles are good fillers with low conductivity for the percolation effect, which induces high dielectric constant and low dielectric loss in the Fe 3 O 4 @BaTiO 3 /PVDF composite. The maximum dielectric constant is up to 3893, and dielectric loss is suppressed below 0.9. Moreover, the shell layer of Fe 3 O 4 can be the trap and scattering centers to injected charges, so that the polarization saturation can be delayed to higher field. Thus, the released energy density of this composite can be enhanced greatly due to higher breakdown strength and lower energy loss.