Dielectric and energy storage performances of PVDF-based composites with colossal permittivitied Nd-doped BaTiO3 nanoparticles as the filler

The energy storage density of pure polymers is usually limited by their low intrinsic dielectric constants (εeff). Integrating polymer matrix with ceramic particles with high εeff values has been one powerful approach to enhance the εeff values of polymer composites and thus their energy storage density. In this study, we report a flexible polymer-based composite by introducing Nd-doped BaTiO3 (NBT) nanoparticles (εeff over 3×105) into the poly(vinylidene fluoride) (PVDF). The phase of PVDF and its dielectric behavior could be adjusted by varying the NBT loadings. Composites including less than 5 vol.% NBT loading exhibited enhanced dielectric constants and maintained high breakdown strength. With a quenching process, the composite delivers a discharged energy density up to 7.91 J/cm3 at an electric field of 350 kV/mm with 2.5 vol.% NBT loading, which is 140% more than that of pure PVDF at the same electric field