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Dielectric ceramic capacitors with ultrahigh power densities are fundamental to modern electrical devices. Nonetheless, the poor energy density confined to the low breakdown strength is a long-standing bottleneck in developing desirable dielectric materials for practical applications. In this instance, we present a high-entropy tungsten bronze-type relaxor ferroelectric achieved through an equimolar-ratio element design, which realizes a giant recoverable energy density of 11.0 J·cm−3 and a high efficiency of 81.9%. Moreover, the atomic-scale microstructural study confirms that the excellent comprehensive energy storage performance is attributed to the increased atomic-scale compositional heterogeneity from high configuration entropy, which modulates the relaxor features as well as induces lattice distortion, resulting in reduced polarization hysteresis and enhanced breakdown endurance. This study provides evidence that developing high-entropy relaxor ferroelectric material via equimolar-ratio element design is an effective strategy for achieving ultrahigh energy storage characteristics. Our results also uncover the immense potential of tetragonal tungsten bronze-type materials for advanced energy storage applications. The authors present an equimolar-ratio element high-entropy strategy for designing high-performance dielectric ceramics and uncover the immense potential of tetragonal tungsten bronze-type materials for advanced energy storage applications. [ABSTRACT FROM AUTHOR]

The most promising candidates for energy storage capacitor application are relaxor ferroelectrics, among which, the perovskite structure ferroelectric ceramics have witnessed great development progress. However, less attention has been paid on tetragonal tungsten bronze structure (TTBS) ceramics because of their lower breakdown strength and polarization. Herein, a multiscale regulation strategy is proposed to tune the energy storage performances (ESP) of TTBS ceramics from grain, domain, and macroscopic scale. The enhanced relaxor behavior with dynamic polar nanodomains guarantees low remanent polarization, while the refined grains and enlarged bandgap ensure increased breakdown strength. Hence, excellent ESP is realized in unfilled TTBS Sr0.425La0.1□0.05Ba0.425Nb1.4Ta0.6O6 (SLBNT) ceramics with an ultrahigh recoverable energy density of 5.895 J cm−3 and a high efficiency of 85.37%. This achievement notably surpasses previous studies in TTBS ceramics and is comparable to that of perovskite components. Meanwhile, the energy density exhibits a wide temperature, frequency, and cycling fatigue stability. In addition, high power density (257.89 MW cm−3), especially the ultrafast discharge time (t0.9 = 16.4 ns) are achieved. The multiscale regulation strategy unlocks the energy storage potential of TTBS ceramics and thus highlights TTBS ceramics as promising candidates for energy storage, like perovskite structured ceramics. [ABSTRACT FROM AUTHOR]

The energy storage performance of antiferroelectric ceramic capacitors has always gain much attention. Hysteresis, transition field, and polarization intensity are crucial factors influencing energy storage performance. A‐site doped small radius ions have been shown in numerous investigations to enhance the switching field, minimize hysteresis, but decrease maximum polarization intensity. How to maintain the high polarization while optimizing other parameters is a great challenge, and this problem has received scant attention in the research literature to date. In this work, Pb1‐xSrx(Zr0.54Sn0.46)0.975Nb0.02O3 (x = 0, 0.02, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.20) antiferroelectric ceramics show high polarization stability. When the Sr2+ content is within 12 mol%, the saturation polarization intensity always remains at a large value (> 44μC/cm2), and the rate of change is as low as 6%. Pb0.92Sr0.08(Zr0.54Sn0.46)0.975Nb0.02O3 also displays great polarization temperature stability with a minimal change rate of 8.5% in a wide temperature range from ‐55 to 85°C. Additionally, this ceramic also has a superior energy storage performance that the recoverable energy density and energy storage efficiency and 8.95 J/cm3 and 80.4%, respectively. This work paves the way for practical simultaneous polarization and other parameter optimization. [ABSTRACT FROM AUTHOR]

Ceramic‐based dielectric capacitor are highly suitable for pulsed power applications due to their high power density and excellent reliability. However, the ultrahigh applied electric field limit their applications in integrated electronic devices. In this work, (1−x){0.96(Bi0.5Na0.5)(Ti0.995Mn0.005)O3‐0.04BiAlO3}‐xNaNbO3 (BNT‐BA‐xNN, x = 0, 0.04, 0.08, 0.12, and 0.16) ternary ceramics were designed to achieve excellent energy storage properties. It was found that the introduction of NaNbO3 (NN) effectively increase the difference (ΔP) between Pmax and Pr, resulting in an obvious enhancement of the energy storage properties. High recoverable energy storage density, responsivity, and power density, that is, Wrec = 2.01 J/cm3, ξ = Wrec/E = 130.69 J/(kV⋅m2), and PD = 25.59 MW/cm3, accompanied with superior temperature stability were realized at x = 0.14 composition. In addition, the thermal stable dielectric properties of the sample can be prominently improved with increasing NN content. The temperature coefficient of capacitance (TCC) of x = 0.16 composition is lower than 15% over the temperature range from 49°C to 340°C, with a high dielectric permittivity of 1647 and a low dielectric loss (0.0107) at 150°C. All these features show that the BNT‐BA‐xNN ceramics are promising materials for energy storage application. [ABSTRACT FROM AUTHOR]

PZT95/5 ferroelectric ceramics are widely utilized in pulsed power devices and the remanent polarization Pr of poled PZT95/5 can characterize the shock-driven energy density. However, this remanent polarization is difficult to be measured nondestructively. In this article, a series of pyroelectric tests of poled PZT95/5 ceramics were conducted near room temperature, from 25°C to 20°C. A linear relation between Pr and pyroelectric coefficient p was found, that is, Pr=1190.5( K)× p, which provides an effective way to nondestructively estimate the value of Pr of the poled PZT95/5 ceramics by measuring the pyroelectric coefficient p at room temperature. According to Devonshire's phenomenological theory, this result could be explained by a modified equation: [ABSTRACT FROM AUTHOR]

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]

Barium Strontium Titanate (Ba 1-x Sr x TiO 3 , BST) possesses the advantages of high permittivity, low remnant polarization and dielectric loss, suggesting great potential in the application of power capacitors. However, the low maximum polarization severely restricts the achievement of outstanding energy storage properties (ESP). Herein, we design a lead-free bulk ceramic: (1-x)Ba 0. 55 Sr 0 · 45 TiO 3 -xBi 0.5 Na 0. 5 TiO 3 [(1-x)BST-xBNT] (x = 0.1–0.4), prepared by two-step solid-state reaction method. The introduction of BNT contributes to (1) the boost of maximum polarization (from 21 μC/cm2 up to 32.6 μC/cm2) due to Bi3+ lone pair covalent effect (2) strong relaxor behavior (1.71≪ γ 1.84) derived from weakly coupled nanopolar regions, which can be verified by high activation energy E a = 0.341 eV at x = 0.3, improves the ESP and thermal stability of the ceramics. According to the above strategies, high W rec = 1.73 J/cm3 and η = 84.4% are achieved in the 0.7BST-0.3BNT ceramics at 206 kV/cm, which is preferable to the previous results regarding BST-based bulk ceramics. The excellent thermal stability (20–120 °C), frequency stability (1–500 Hz), as well as anti-fatigue characteristic (cycling number: 105) were obtained in the 0.7BST-0.3BNT. Furthermore, 0.7BST-0.3BNT ceramics exhibit high-power density (P D = 44.9 MW/cm3) and rapid discharge rate (t 0.9 = 99.2 ns) from 20 °C to 120 °C. This work provides a feasible way to achieve good energy storage and charge-discharge properties for pulse power energy storage systems. [ABSTRACT FROM AUTHOR]

In this work, TiO 2 nanowire arrays embedded in PbZrO 3 -based antiferroelectric (AFE) films were fabricated on FTO/glass substrates using a facile two-step method. The energy storage performance was modulated by changing the density and morphology of TiO 2 nanowire arrays. A large recoverable energy density (W re) of 50.6 J/cm3 and efficiency (η) of 61% were achieved, which was attributed to the enhancement of maximum polarization and breakdown strength by constructing TiO 2 nanowire arrays in AFE films. More importantly, the composite films exhibited excellent thermal stability with the variation of energy storage density (<5%) and efficiency (<7%) in a wide temperature range (−120 to 130 °C) at the operating electric field of 1300 kV/cm. The results demonstrate that the composite films have huge potential in the future energy storage applications, whether in cold polar regions or high temperature regions. [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]

The composition dependent dielectric, ferroelectric and energy storage properties of tetragonal lead lanthanum zirconate stannate titanate (PLZST) antiferroelectric ceramics were systematically studied in this paper. Two sets of simple linear scaling relations were established for the forward switching field E AFE-FE , the backward switching field E FE-AFE and recoverable energy density W re . As Zr content increases (Ti fixed), E AFE-FE , E FE-AFE , W re decreases linearly, while the stored energy density W st declines first and then increases. In addition, decreasing Ti content (Zr fixed) leads to linear increments in all of E AFE-FE , E FE-AFE , W re and W st . These results not only reveal the superiority of PLZST with lower Zr and lower Ti contents for energy storage capacitors, but also provide a fast way to design PLZST ceramics with specific energy storage properties. Our work may also be very helpful for better understanding the mechanism of phase transition behaviors of antiferroelectric materials. [ABSTRACT FROM AUTHOR]

• The comprehensive optimization strategy of discharge curve can serve as the paradigm of conceptual materials. • A balance between W re = 5.92 J/cm3 and η = 81.7% is gotten in the BSZT-BMN-0.06 ceramic. • The mechanism of core–shell structure enhancing breakdown strength is clarified. • BSZT-BMN-0.06 ceramics owns a fast charge–discharge speed (44 ns) and a high P D of 144 MW/cm3. The conventional dielectric ceramics are extensively studied for applications in electronics and pulsed power systems owing to the advantages of high voltage and high power density. However, the inferior energy storage performance is difficult to satisfy the development requirements of integration and lightweight of power electronic devices. The main research efforts have been done to improve the energy storage density by enhancing the electric breakdown strength (BDS) or effective dielectric constant (ΔP/ΔE) due to the contradiction between ΔP/ΔE and BDS. Here, it is proposed to use composition design and microstructural core–shell engineering to surmount this contradiction and thus enhance the energy storage density. The heterogeneous microstructures are introduced through a two-step calcination, and the appearance of this microstructure is related to the destruction of the cooperative diffusion effect of multiple ions. Consequently, 0.93Ba 0.55 Sr 0.45- x Zn x TiO 3 -0.07BiMg 2/3 Nb 1/3 O 3 (BSZT-BMN- x) ceramics with core–shell microstructure prepared by traditional solid-state reaction method exhibits an ultrahigh recoverable energy density of 5.92 J/cm3, a superior energy storage efficiency of 81.7% and an outstanding charge–discharge performance (P D = 144 MW/cm3, t 0.9 = 44 ns). The experimental results and numerical simulations reveal that the doping of Zn2+ enhances the potential for off-centering of anions and cations, the core–shell microstructure makes the distribution of electric field to be regulated and the effective path of electric trees is extended to improve the BDS. The present research not only offers a novel paradigm for other material systems to further improve energy storage performance, but also should be generalizable for other functional materials for which a high BDS is required. [ABSTRACT FROM AUTHOR]