P-E hysteresis loop going slim in Ba0.3Sr0.7TiO3-modified Bi0.5Na0.5TiO3 ceramics for energy storage applications

Abstract

(Ba0.3Sr0.7)x(Bi0.5Na0.5)1-xTiO3 (BSxBNT, x = 0.3–V0.8) ceramics were prepared to investigate their structure, dielectric and ferroelectric properties. BSxBNT ceramics possess pure perovskite structure accompanied from a tetragonal symmetry to pseudo-cubic one with the increase of x value, being confirmed by X-ray diffraction (XRD) and Raman results. The Tm corresponding to a temperature in the vicinity of maximum dielectric constant gradually decreases from 110 °C (x = 0.3) to -45 °C (x = 0.8), across Tm = 36 °C (x = 0.5) with a maximum dielectric constant (ɛr = 5920 @1 kHz) around room temperature. The saturated polarization Ps gradually while the remnant polarization Pr sharply decreases with the increase of x value, making the P-E hysteresis loop of BSxBNT ceramics goes slim. A maximum difference between Ps and Pr (Ps-Pr) is obtained for BSxBNT ceramics with x = 0.5, at which a high recoverable energy density (Wrec = 1.04 J/cm3) is achieved under an applied electric field of 100 kV/cm with an efficiency of η = 77%. Meanwhile, the varied temperature P-E loops, fatigue measurements, and electric breakdown characteristics for the sample with x = 0.5 indicate that it is promising for pulsed power energy storage capacitor candidate materials.