High Energy Storage and Excellent Thermal Stability in Ternary (1−x)[0.94(Bi0.5Na0.5)TiO3‐0.06BaTiO3]‐xCa(Mg1/3Nb2/3)O3 Lead‐Free Ferroelectric Ceramics

Abstract In this work, a new type of ternary lead‐free ferroelectric ceramics (1− x )[0.94(Bi 0.5 Na 0.5 )TiO 3 ‐0.06BaTiO 3 ]‐ x Ca(Mg 1/3 Nb 2/3 )O 3 is synthesized by traditional solid‐state reaction method ( x = 0.02, 0.04, 0.06, 0.07, 0.08, 0.10, and 0.15). No phase transition is detected and all ceramics exhibited the perovskite structure consisting of the rhombohedral ( R3c ) and tetragonal ( P4bm ) phases. By increasing the Ca(Mg 1/3 Nb 2/3 )O 3 (CMN) content, the average grain size shows a slight change. More specifically, the grain size is 1.00 µm when x < 0.10 and then increases to 1.20 µm in x = 0.10 and 0.15. When x = 0.07, an optimum energy storage performance with recoverable energy density ( W rec ) of 4.13 J cm −3 is achieved under an electric field of 340 kV cm −1 . At the same time, it exhibits excellent pulse performance at 25 °C, with an effective discharging time ( t 0.9 ) of 3.2 ns and a discharge energy density ( W D ) of 0.61 J cm −3 , suggesting a fast charging–discharging rate. In addition, the current density ( C D ) and power density ( P D ) are 92.31 A cm −2 and 6.46 MW cm −3 , respectively. Overall, the 0.93[0.94(Bi 0.5 Na 0.5 )TiO 3 ‐0.06BaTiO 3 ]‐0.07Ca(Mg 1/3 Nb 2/3 )O 3 ceramics is considered a competitive candidate for the development of high‐energy storage capacitors and pulse‐power devices.