Dielectric and energy storage properties of ternary doped barium titanate-based ceramics

In this study, lead-free ceramics (1−x)[0.90BaTiO₃–0.10Bi(Mg_1/2Ti_1/2)O₃]–x(Na_0.5Bi_0.5)_0.7Sr_0.3TiO₃ (abbreviated as (1−x)(BT-BMT)–xBNST, x = 0.00, 0.05, 0.10, 0.15, and 0.20) were prepared using the solid-phase reaction method. The effect of (Na_0.5Bi_0.5)_0.7Sr_0.3TiO₃ (BNST) doping on the dielectric and energy-storage properties of 0.90BaTiO₃–0.10Bi(Mg_1/2Ti_1/2)O₃ (BT-BMT) ceramics was investigated. The maximum polarization strength (P_max) was obtained when x = 0.15 at a breakdown field (E_b) of 480 kV/cm, and the optimal energy-storage performance was W_rec = 4.25 J/cm³ and η = 87.49%. Excellent stability in both frequency and temperature was observed in the frequency conversion range of 1–120 Hz and variable temperature test from 30 to 140 °C. Moreover, the BT-BMT–0.15BNST energy-storage ceramics with rapid discharge (t_0.9 = 4 ~ 47 ns), high power density (P_D = 155.2 MW/cm³), and stable performance have great potential in pulse capacitors. In this study, we successfully developed ternary-doped energy-storage ceramics with outstanding energy-storage capabilities in BNT matrices. We comprehensively examined their crystal structures, microstates, and energy-storage properties. These insights offer new perspectives for research in the field of lead-free barium titanate-based ceramics.