High Energy Storage Characteristics of (0.5–<i>x</i>)BiFeO₃-0.5 Bi_0.5Na_0.5TiO₃-<i>x</i>BaTiO₃ Ternary Lead-Free Ferroelectric Ceramics under Low Electric Field

(0.5–x)BiFeO3-0.5 Bi0.5Na0.5TiO3-xBaTiO3 (x = 0.12, 0.14, 0.16, 0.18, 0.20, 0.22, 0.24, and 0.28) ferroelectric ceramics were synthesized using traditional solid-state reaction methods. The elongated P–E hysteresis loops revealed that the ternary system had good energy storage characteristics. A high recoverable energy storage density (Wrec) of 2.1 J/cm3 and a moderate energy storage efficiency of η ∼ 67% were achieved simultaneously for the x = 0.12 composition under a lower electric field of 140 kV/cm. Furthermore, the x = 0.12 composition exhibited good stability in a wide temperature (25–125 °C) and frequency range (0.1–102 Hz) and good fatigue resistance in cycling frequency (1–103). Furthermore, the ceramic also exhibited considerable charging–discharging performance with a fast discharging rate (t90 < 0.05 μs), a moderate current density (158 A/cm2), and a moderate power density (4.738 MW/cm3). Overall, 0.38BiFeO3-0.5Bi0.5Na0.5TiO3-0.12BaTiO3 ceramics are considered a lead-free competitive candidate for the development of high energy storage capacitors.