High efficiency and power density relaxor ferroelectric Sr0.875Pb0.125TiO3- Bi(Mg0.5Zr0.5)O3 ceramics for pulsed power capacitors

Abstract Ferroelectric (1-x)Sr0.875Pb0.125TiO3-xBi(Mg0.5Zr0.5)O3 ( (1-x)SPT-xBMZ, x = 0-0.2) ceramics with high discharge efficiency and power density were synthesized via a conventional solid-state sintering method. The prepared (1-x)SPT-xBMZ ceramics were detected as a pure perovskite structure and a dense microstructure, and a typical relaxor behavior and an excellent temperature stability were also observed. Although there is no direct correlation between the degree of diffuseness and the maximum polarization, the high degree of diffuseness can reduce the remanent polarization and significantly improve energy storage and release characteristics of ferroelectric ceramics. Based on a polarization electric-field loop measurement, a recoverable energy storage density of 0.762 J/cm3 and a very high efficiency of 96.34% are achieved when x = 0.2 under 150 kV/cm. The energy storage properties of 0.8SPT-0.2BMZ ceramic exhibit good temperature stability (25-130 °C) and frequency stability (2-80 Hz). In a practical charge-discharge circuit testing, a short discharge pulse-period about 94 ns, a high discharge energy density of 1.7 J/cm3 and an ultra-high-power density of 62.8 MW/cm3 are obtained for the 0.8SPT-0.2BMZ ceramic at 240 kV/cm. The results indicate that the 0.8SPT-0.2BMZ ceramic is a promising dielectric material for high-power pulse capacitors.