The role of dielectric permittivity in the energy storage performances of ultrahigh-permittivity (SrxBa1−x)(Ti0.85Sn0.15)O3 ceramics

Abstract

Dielectrics for energy storage devices should commonly achieve the requirement of high permittivity, large breakdown strength, and large polarization when used in harsh working environments. A question is gradually raised about permittivity/polarization/breakdown strength in a dielectric for high voltage applications which one is more conducive to energy storage performances. Here, an attempt has been made to investigate the effect of high permittivity on the energy performances of dielectric materials in order to provide a viable option for high voltage devices. High values of dielectric permittivity (1300–7400) combined with low dielectric loss (< 0.8%) are obtained from single-phase (Sr, Ba)(Ti0.85Sn0.15)O3 ceramics by solid-state sintering method. Although permittivity varies greatly, energy performance is basically limited on the same order of < 1.0J/cm3 if measured at low bias field. An interesting finding is that breakdown strength dominates the energy performances in dielectric materials regardless of the great difference of dielectric permittivity, especially at ultrahigh electric fields.