Energy storage in polymer films with high dielectric constant fillers

Although a polymer filled with high dielectric constant particles is appealing because of greater dielectric constant and energy density, it also has its setbacks. For instance, only a small amount of electric field resides in the filler at low-volume fractions of high dielectric contrast filler. A majority of the increase in effective dielectric constant results from an increase of electric field in the polymer matrix. As such, researchers studied other geometries with spherical filler volume fractions of 9%, 27%, 31%, 34%, 40% and 44% and for spheroidal filler volume the fractions are 9.3%, 13.7%, 18%, and 26.1% for dielectric constraints ranging from 3-3000. It was found that relatively high dielectric contrast is desirable to achieve a large effective dielectric constant and energy density. On the one hand, a threshold volume fraction of filler exists for high-dielectric contrast.