Simultaneously achieving ultrahigh energy storage density and energy efficiency in barium titanate based ceramics

Abstract

BaTiO3–BiMeO3 (Me represent trivalent or average trivalent metallic ions) lead-free relaxor ferroelectrics have been demonstrated to be excellent candidates for dielectrics in pulsed power capacitor applications. However, the recoverable energy density (Urec) needs to be further improved to fulfil the demands of miniaturization and integration in electronic devices. In this work, an ultrahigh Urec of 3.282 J/cm3 was obtained in (1-x)BaTiO3-xBi(Mg2/3Ta1/3)O3 (xBMT) (x = 0.12) lead-free ceramics. The significantly enhanced Urec was first reported in BT-based bulk ceramics. Meanwhile, all components exhibit ultrahigh energy storage efficiency (η) of ≥93% under a strong electric field (≥300 kV/cm), which may be attributed to the low leakage current caused by the introduction of Ta ions. In addition, excellent temperature, frequency and fatigue stabilities (variation of Urec < 9% over 25–140 °C, Urec > 2 J/cm3 in 1–100 Hz and Urec < 2% after 104 cycles) can be observed. These results demonstrate that 0.12BMT relaxor ferroelectrics can be considered a promising lead-free material for application in pulsed power systems.