The enhancement of energy storage performance in high-entropy ceramic

Abstract

Dielectric capacitors are used in pulsed power devices due to their high-power density. The energy storage density and efficiency need to be further improved to widen their applications. This work investigates the energy storage of high entropy ceramic (Pb0.25Ba0.25Ca0.25Sr0.25)TiO3 synthesized by the solid-state method. The Bi(Mg2/3Nb1/3)O3 (BMN) is introduced to enhance its energy storage performance. The introduction of BMN from x = 0 to 0.15 reduces the grain size from 5.9 μm to 245 nm, increases the band gap from 2.98 to 3.05 eV, and improves the differences between saturation and remnant polarization from 11.85 to 14.60 μC/cm2. The phase diagram of this system was constructed by dielectric properties analysis to understand the effect of Bi(Mg2/3Nb1/3)O3 in the energy storage performance. The optimal energy density of 5.58 J/cm3 and efficiency of 89.4% was achieved in 0.9PBCST-0.1BMN which can be promising candidates for application in dielectric energy storage.