Enhanced Energy Storage Properties of BNT–ST–AN Relaxor Ferroelectric Ceramics Fabrication by the Solid-State Combustion Technique

Abstract

The performance of high energy storage lead free 0.722(Bi0.5Na0.5TiO3)−0.228(SrTiO3)−0.05(AgNbO3) (BNT–ST–AN) ceramics prepared by the solid-state combustion technique, using glycine as fuel is studied here. All samples are investigated for their phase formation, microstructure, dielectric, ferroelectric, and energy storage characteristics. A single perovskite phase of BNT–ST–AN is obtained from the powder calcined at 750 °C for 4 h. The sintered BNT–ST–AN ceramics present a single perovskite structure with coexisting rhombohedral (R) and cubic (C) phases in all samples. The percentage of the R phase increases while the percentage of the C phase decreases when the sintering temperature increases from 1075 to 1125 °C and then shows an opposite trend. A good microstructure, the highest density (5.42 g cm−3), the highest dielectric constant (ε r ≈ 1871 and ε m ≈ 3396), the highest electric breakdown strength (E b ≈ 130 kV cm−1) and excellent total energy storage density (W total ≈ 3.07 J cm−3), recoverable energy storage density (W rec ≈ 2.25 J cm−3) and efficiency (η ≈ 75.88%) with coexisting phases of R (62%) and C (38%) are achieved from the sample sintered at 1125 °C for 2 h. Moreover, this sample exhibits temperature and frequency stability of the energy storage properties in the range from 25 to 150 °C and 1 to 20 Hz, respectively.