Outstanding Energy Storage Performance of Na_0.5Bi_0.5TiO₃‑BaTiO₃‑(Sr_0.85Bi_0.1)(Mg_1/3Nb_2/3)O₃ Lead-Free Ceramics

Lead-free (1 – x)­(0.94Na0.5Bi0.5TiO3-0.06BaTiO3)-x(Sr0.85Bi0.1)­(Mg1/3Nb2/3)­O3 ((1 – x)­(NBT-BT)-xSBMN) ceramics are synthesized using the traditional solid-state reaction method. The introduction of SBMN leads to a dense microstructure with small mean grain size. The temperature-dependent dielectric spectrum reveals that the sample with x = 0.24 shows the best temperature stability with TS occurring around room temperature. A large recoverable energy storage density value of 3.05 J/cm3, high efficiency of 89%, and excellent temperature (25–140 °C)/frequency (1–100 Hz) stabilities are simultaneously achieved in the ceramic. The variation of recoverable energy storage density is less than 7% in the temperature range of 25–140 °C. The ceramic also has a high power density of 67.86 MW/cm3