New Antiferroelectric Perovskite System with Ultrahigh Energy-Storage Performance at Low Electric Field

The development of antiferroelectric (AFE) materials with high recoverable energy-storage density (Wrec) and energy-storage efficiency (η) is of great importance for meeting the requirements of miniaturization and integration for advanced pulse power capacitors. However, the drawbacks of traditional AFE materials, namely, high critical field (Ecr) and low Wrec, make them unsuitable to be utilized in practical applications. To increase Wrec and η, here we report an effective approach using the transient liquid-phase sintering and the softening of antiferroelectric order to decrease the porosity, enhance the dielectric breakdown strength (DBS), and increase the maximum electric-field-induced polarization (Pmax) of the AFE ceramics. On the basis of this concept, a novel solid solution of (1 – x)PbHfO3–xPb(Mg1/2W1/2)O3 [(1 – x)PHf–xPMW] was designed and prepared in the form of ceramics by the solid-state reaction method. Their crystal structures, phase transitions, dielectric properties, and energy-storage properties were investigated systemically. X-ray diffraction analysis indicates the formation of solid solution with a partial order on the B site at room temperature in a broad composition range. Dielectric measurements reveal that the AFE to ferroelectric (FE) phase-transition temperature shifts toward room temperature with the increasing Pb(Mg1/2W1/2)O3 (PMW) content. The optimal energy-storage performance is found for the 0.90PHf–0.10PMW ceramic with the highest Wrec of 3.7 J/cm3 (at a relatively low electric field of 155 kV/cm) and a favorable η of 72.5% among all of the studied compositions, which is much superior to that of the so far reported perovskite ceramics under the similar electric fields. This is the first reported PHf-based solid solution with ultrahigh energy-storage density. The enhanced energy-storage performance can be attributed to the improved DBS and enhanced Pmax (45 μC/cm2) due to the incorporation of PMW that leads to dense microstructure and softens the antiferroelectricity. The results show that the (1 – x)PHf–xPMW ceramics form a new family of promising AFE candidates with significantly enhanced DBS, Wrec, and η. This work also demonstrates the design methodology for developing not only the PbHfO3-based but also other new AFE–AFE solid solution material for high-energy-storage applications.