Improved energy storage properties of Sr(Zr0.8Nb0.16)O3-doped Bi0.47Na0.47Ba0.06TiO3 ceramics with excellent temperature/frequency stability

Lead-free perovskite dielectric materials for capacitors have received wide concern in recent years, but their energy storage density and efficiency still cannot meet the growing application demand for practical applications. In this work, we prepared a lead-free relaxor ferroelectric ceramic of (1-x)Bi0.47Na0.47Ba0.06TiO3-xSr(Zr0.8Nb0.16)O3, which was synthesized via a normal solid-state route. The microstructure, dielectric properties and energy storage behavior of the ceramics were explored. The ceramics can be well sintered and situated in the region where rhombohedral and tetragonal phases coexist. The addition of Sr(Zr0.8Nb0.16)O3 (SZN) significantly extends the dielectric-temperature plateau between Ts and Tm and reduces the remnant polarization Pr, but the large saturation polarization Ps is still maintained. Besides, the doping of SZN enhances the relaxation of the material and increases the dielectric breakdown strength (DBS) from 50 kV/cm (x = 0) to 100 kV/cm (x = 0.04 and 0.06). Therefore, the ceramic with x = 0.06 exhibits a high discharging efficiency (η) of 71.1% and energy density (W) of 1.56 J/cm3 at 100 kV/cm and shows the superior thermal stability with the changes in recoverable energy density (Wrec) and η of less than 10% and 30% at the temperature range of 25–180 °C and the excellent frequency stability with the variations of Wrec and η of less than 1.8% and 1% at the frequency range of 10 Hz–100 Hz.