High temperature energy storage properties of Bi0.5Na0.5TiO3 based ceramics modified by NaNbO3

Abstract Bi0.5Na0.5TiO3 based ceramics have attracted many researchers’ attentions due to their versatility. The temperature stability of dielectric properties of BNT-BT ceramics is reported to be improved by NaNbO3 and tungsten bronze-structured Sr0.8Na0.4Nb2O6. But their effects on energy storage properties are still unknown. In this work, NaNbO3 and tungsten bronze-structured compound Sr0.8Na0.4Nb2O6 modified Bi0.5Na0.5TiO3-0.06BaTiO3 ceramics (1-x)(0.98(0.94Bi0.5Na0.5TiO3-0.06BaTiO3)−0.02Sr0.8Na0.4Nb2O6)-xNaNbO3, x = 0.15–0.30, abbreviated as BNT-BT-SNN-xNN) were designed and prepared. It is found that NaNbO3 is conducive to enhance the energy storage properties. BNT-BT-SNN-0.20NN has optimum energy storage properties, with the recoverable energy-storage density (Wrec) of 1.52 J/cm3 and energy-storage efficiency (η) of 82%, under the applied electric field of 140 kV/cm. In addition, the energy-storage properties exhibit good temperature stability, with variances of Wrec and η being less than 8.70% and 1.99% respectively in the temperature range from room temperature (RT) to 160 °C. Furthermore, the overdamped and underdamped discharge energy storage properties were also studied. The energy density Wd, discharge time t0.9, current density CD, and power density PD of BNT-BT-SNN-0.20NN ceramic are very stable from room temperature to 100 °C. These results indicate that NaNbO3 compound is beneficial to improve the energy storage properties and their temperature stability of Bi0.5Na0.5TiO3-based ceramics.