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Due to the high demand for dielectric materials with high energy density, the energy storage performance of antiferroelectric ceramic capacitors has always gained much attention. Polarization intensity is a key factor that is closely related to the energy storage density. However, thus far, there has been a lack of research studies or successful methods to effectively modulate polarization intensity. The behavior of the polarization process is complex and contains domain nucleation, growth, and flip-flapping. Based on this finding, the introduction of Nb5+ at the B-site was designed to influence the three stages of antiferroelectric polarization by regulating the balance between the ferroelectric and antiferroelectric phases, and eventually realized regulation of the saturation polarization intensity in the (Pb 1-1.5x La x)(Zr 0.5 Sn 0.43 Ti 0.07)O 3 antiferroelectric ceramics. The saturation polarization intensity has increased from 25.56 to 42 μC/cm2 with Nb5+ content increases from 0 to 4 mol% and the hysteresis was kept low, Pb 0.94 La 0.04 (Zr 0.65 Sn 0.35) 0.975 Nb 0.02 O 3 is the optimal component with a high releasable energy density of 8.26 J/cm3 and an energy storage efficiency of 90.31%. This work provides an in-depth explanation of the microscopic mechanism of antiferroelectric ceramic polarization and presents a novel approach for the composition design of high-energy storage density antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]

• An ever-unadoped strategy was employed to design superparaelectric phase in AgNbO 3. • A new simple composition to obtain high ESP ceramic materials is proposed. • High W rec of 7.6 J/cm3 and E b of 522 kV/cm are obtained. Ceramics capacitors, especially featuring antiferroelectric (AFE) structure, are widely used in pulsed power electronic systems due to distinctive high-power density and external field stability. Lead-free AFE material AgNbO 3 has seized substantial research attention owing to its unique temperature driven multi-level phase transitions, and many works have greatly improved the energy storage properties by engineering these temperature-dependent phase boundaries. In this work, an ever-unadopted strategy was proposed to modulate the relaxor structure in AgNbO 3 by designing room-temperature (RT) superparaelectric phase via Bi incorporation into AN lattice matrix. Structural analysis shows M phase (space group Pbcm) evolves into O phase (space group Cmcm) with 12 mol.% Bi-substitution, breaking the long-range AFE order into polar nanoregions. Hence, an ultra-high recoverable energy density (7.6 J/cm3) and a high efficiency (79 %) are simultaneously achieved in the Ag 0.64 Bi 0.12 NbO 3 ceramics under 52.2 kV/mm. Moreover, the excellent energy storage properties are accompanied with good temperature and frequency stability, with the variation of W rec less than ± 15% (over 25–120 °C) and ± 10% (over 1–200 Hz) under 25 kV/mm, respectively. The novel approach reported herein provides a new guidance for designing AgNbO 3 -based and other AFE materials for high-performance energy storage applications. [ABSTRACT FROM AUTHOR]

Recently, the (Pb,La)(Zr,Ti)O 3 antiferroelectric materials with slim-and-slanted double hysteresis loops have been widely drawn in the application of advanced pulsed power capacitors due to its low strain characteristic. In this work, the energy storage properties of (Pb 0.895 La 0.07)(Zr x Ti 1- x)O 3 ceramics with different Zr contents are researched thoroughly because the substitution of Ti4+ by Zr4+ can reduce the tolerance factor t , enhancing the antiferroelectricity. The polarization-electric field hysteresis loops of the PLZT ceramics become slimmer with increasing Zr content. The highest recoverable energy storage density (W re) of 3.38 J/cm3 and ultrahigh energy efficiency (η) of 86.5% are achieved in (Pb 0.895 La 0.07)(Zr 0.9 Ti 0.1)O 3 ceramic. The (Pb 0.895 La 0.07)(Zr 0.9 Ti 0.1)O 3 ceramic also hold fairly thermal stability (relative variation of W re is less than 28% over 30 °C-120 °C), excellent frequency stability (10–1000 Hz) and good fatigue endurance. These results demonstrate that the (Pb 0.895 La 0.07)(Zr 0.9 Ti 0.1)O 3 ceramic can be a desirable material for dielectric energy storage capacitors, especially for pulse power technology. [ABSTRACT FROM AUTHOR]

Abstract Bulk ceramics with high recoverable energy density (W re) and energy efficiency (η) play a critical role in the development of pulsed power systems for miniaturization and lightweight. The orthorhombic phase (Pb,La)(Zr,Ti)O 3 -based antiferroelectric (AFE) ceramics have been regarded as one of the most promising candidates for pulsed power system applications due to their relatively high energy storage density and efficiency. However, the main drawback of orthorhombic phase (Pb,La)(Zr,Ti)O 3 -based AFE ceramics is relatively low dielectric breakdown strengthen (DBS), which has always restricted the improvement of energy storage density. In this study, an effectively method to increase DBS by the introduction of Mn has been proposed. The relative density of orthorhombic phase (Pb 0.91 La 0.06)(Zr 0.96 Ti 0.04)O 3 (PLZT) ceramics was improved by Mn-doping. And the introduction of Mn can decrease the tolerance factor (t) of PLZT ceramics because the radius of Mn2+ is larger than that of B-site Zr4+/Ti4+, and thus enhancing antiferroelectricity. Meanwhile, the effects of Mn-doping on the phase structure, microstructure and dielectric properties of PLZT ceramics have been studied thoroughly in this study. It is found that the highest W re of 7.65 J/cm3 is obtained at 1.0 mol% Mn-doped PLZT ceramic, which is obviously larger than that of undoped PLZT ceramic (5.71 J/cm3). These results suggest that the Mn-doped PLZT ceramics are potential energy storage materials in pulsed power systems. Highlights • Enhanced the dielectric breakdown strengthen of pure antiferroelectric ceramics by Mn-doping. • Obtained a high recoverable energy density of 7.65 J/cm3 and relatively high η of 87% in Mn-doped antiferroelectric ceramics. • Better understanding of the mechanism on energy storage properties of Mn-doped antiferroelectric ceramics. [ABSTRACT FROM AUTHOR]