Energy storage performance of PVDF composites enhanced by two-dimensional Na0.5Bi0.5TiO3 with high polarization

With the increasing consumption of non-renewable energy sources such as fossil fuels, human beings are facing the crisis of energy shortage. Therefore, researchers in most regions and countries in the world are actively committed to designing and developing new dielectric energy storage components with high energy storage density and high energy storage efficiency. In this work, 2-dimensional flaky Na0.5Bi0.5TiO3 (NBT) inorganic powders were prepared by the two-step molten salt method and compounded with polymer polyvinylidene fluoride (PVDF). NBT/PVDF monolayer and 'sandwich' structure composites were prepared by the tape casting method, and the flaky NBT powders were arranged in parallel in the PVDF matrix. The phase and microstructure of the prepared NBT powders were analyzed by X-ray diffractometer and scanning electron microscope. The dielectric, conductivity, ferroelectric, and energy storage properties of the prepared composites were tested. The results show that the critical breakdown field strength of the prepared single-layer NBT/PVDF and 'sandwich' structure composites with a volume fraction of 0.75 vol.% NBT inorganic powder is 380 kV/mm and 540 kV/mm, respectively. The energy storage density reaches 13.78 J/cm3 and 21.57 J/cm3, which is about 1.87 and 3.01 times the volume fraction of 0 vol.%.