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Lead‐based antiferroelectric (AFE) ceramics have attracted increasing interest in pulse power systems owing to their high‐energy storage and power densities. However, the single AFE–ferroelectric (FE) phase transition in conventional AFE materials usually leads to premature polarization saturation and low breakdown strength, which are disadvantageous to energy storage performance. In this study, high energy storage performance was achieved in Pb0.94−xLa0.04Cax[Nb0.02(Zr0.99Ti0.01)0.975]O3 (PLCNZT) AFE ceramics by constructing electric‐field‐induced multiple phase transitions. A maximum recoverable energy storage density of 12.15 J/cm3 and a high energy efficiency of 85.4% were obtained for the PLCNZT ceramic with x = 0.03 at 420 kV/cm. These excellent properties are attributed to the AFE–FE Ⅰ‐FE Ⅱ multiple phase transitions induced by Ca2+ doping, which effectively enhances the breakdown strength. This result indicates that field‐induced multiple phase transitions significantly improve the energy storage of AFE materials. [ABSTRACT FROM AUTHOR]

• Large recoverable energy storage density of 2.9 J/cm3 is obtained in BNT-BST-CZ ceramic. • The ceramic shows excellent dielectric permittivity stability at 44-483 °C. • The ceramic owns a fast charge-discharge speed of 110 ns. In the 0.9(0.65Bi 0.5 Na 0.5 TiO 3 -0.35Bi 0.2 Sr 0.7 TiO 3)-0.1CaZrO 3 ceramic, superior energy storage performance and excellent dielectric stability have been achieved, along with a higher discharge rate. Our finding suggests that the ceramic has great potential applications in pulsed power systems and high-temperature capacitors. [Display omitted] Novel (1− x)(0.65Bi 0.5 Na 0.5 TiO 3 -0.35Bi 0.2 Sr 0.7 TiO 3)- x CaZrO 3 (BNT-BST- x CZ, x = 0–0.15) ceramics were manufactured through a solid phase sintering process and their structural and electrical performance have been systematically investigated. By doping CaZrO 3 , a higher recoverable energy storage density of 2.9 J/cm3 and energy storage efficiency of 80% at 330 kV/cm can be simultaneously obtained in BNT-BST-0.1CZ ceramic. Further analysis with the aid of finite element simulation indicates that the improvement of energy storage performance lies in the refined grain size and reduced defects, which are both conductive to improve the dielectric breakdown strength. More importantly, incorporating CaZrO 3 gives slimmer hysteresis loops as well as excellent temperature (20–150 °C) and frequency (5–200 Hz) stability of energy storage properties. Moreover, a stable dielectric permittivity of in an ultra-wide range from 44 °C to 483 °C was achieved in BNT-BST-0.10CZ ceramic. Our findings suggest that the BNT-BST-0.1CZ ceramic has great potential applications in pulsed power systems and high-temperature capacitors. [ABSTRACT FROM AUTHOR]

The urgent requirement of environment-friendly materials with excellent energy storage performance for pulse power systems has sparked considerable research on lead-free ceramics. In this work, a new lead-free 0.90(0.80NaNbO3–0.20Sr0.7Bi0.2TiO3)–0.10BaSnO3 ceramic with high recoverable energy storage density (Wr = 3.51 J/cm3) and decent energy storage efficiency (η = 70.85%) has been obtained. In particular, these ceramics exhibit an ultrahigh breakdown strength of 402 kV/cm due to the dense microstructure and small grain size. The impedance analysis also reveals that the incorporation of BaSnO3 is conducive to the enhancement of insulation ability and breakdown strength. Additionally, great thermal stability (ΔWr < 10% over 20–120 °C at 200 kV/cm) and fatigue resistance (ΔWr < 1% after 120,000 electrical cycles at 200 kV/cm) are observed, indicating that the 0.90(0.80NaNbO3–0.20Sr0.7Bi0.2TiO3)–0.10BaSnO3 ceramics have promising application prospect for high-temperature energy storage devices in pulse power applications. [ABSTRACT FROM AUTHOR]

Dielectric energy-storage capacitors are of great importance for modern electronic technology and pulse power systems. However, the energy storage density (W rec) of dielectric capacitors is much lower than lithium batteries or supercapacitors, limiting the development of dielectric materials in cutting-edge energy storage systems. This study presents a single-phase BaTiO 3 -based high-entropy (BT-H) ceramic, which is synthesized using a conventional solid-state reaction method. It is found that the BT-H ceramic exhibits a remarkable energy storage performance, with a W rec of 5.18 J/cm3 and an ultrahigh η of 93.7% at 640 kV/cm electric field. Moreover, it also features wide temperature stability and excellent frequency stability. It is proposed that the introduction of high entropy enhances the random electric field and stress field, leading to lattice distortion and reduction of nanometer domain size, which in turn reduces remnant polarization and increases electric breakdown strength. This research provides a novel approach to improve the energy storage performance of ceramics through the high-entropy strategy. • High-entropy engineering could enhance the energy storage performance of dielectric capacitors. • An ultrahigh W rec of 5.18 J/cm3 and η of 93.7% at 640 kV/cm electric field were achieved in the BT-H (Mg) ceramics. • The BT-H ceramics exhibit remarkable energy storage performance stability. [ABSTRACT FROM AUTHOR]

• High-entropy design strategy was adopted in this work. • The W rec of 7.6 J/cm3 and η of 90% were obtained in fabricated high-entropy ceramic. • The ceramic displayed good thermal/frequency/fatigue-resistance stability. Dielectric capacitors have gained much attention in next-generation advanced pulse power systems owing to their ultrafast charging/discharging rate. However, the early polarization saturation and large hysteresis hinder the enhancement of recoverable energy-storage density (W rec) with increasing electric field. Here, we design (Bi 0.5 Na 0.5)TiO 3 -based high-entropy dielectric capacitors to modulate polarization behavior and maximize the energy storage capacity. An ultrahigh W rec of 7.6 J/cm3, together with a high η of 90% is simultaneously obtained, showing great competitiveness among the (Bi 0.5 Na 0.5)TiO 3 -based energy storage ceramics. On the one hand, the linear-like P - E loops induced by enhanced random field, which is achieved by increasing the atomic configurational entropy, delay the polarization saturation and ensure the rapid enhancement of W rec under higher electric fields. On the other hand, the high efficiency (η) is assured due to the existence of polar nanoregions (PNRs) and the absence of relaxor ferroelectric to ferroelectric transition. Noticeably, the ceramic also exhibits excellent thermal stability (Δ W rec < 4.4%, Δ η < 10.3%, −50–200 °C), cycling stability (Δ W rec < 0.085%, Δ η < 0.12%, 1–105) and frequency stability (Δ W rec < 7.08%, Δ η < 3.79%, 1–200 Hz). This work reveals that regulating the entropy is an effective method to design high-performance dielectric capacitors. [ABSTRACT FROM AUTHOR]

To meet the booming demands for advanced pulse power systems, developing dielectric ceramics with excellent energy storage performance is extremely urgent. In this work, a composition modulation strategy was adopted for designing Bi 0.5 K 0.5 TiO 3 -based ceramics. That is, incorporating Bi(Mg 0.5 Hf 0.5)O 3 into 0.6Bi 0.5 K 0.5 TiO 3 -0.4Sr 0.7 Bi 0.2 TiO 3 matrix (abbreviated as (1- x)(BKT-SBT)- x BMH, x = 0.00, 0.04 and 0.08). The energy storage performance of the (1- x)(BKT-SBT)- x BMH ceramics was enhanced by increasing the breakdown strength. Ultimately, a recoverable energy density (W rec) of 4.25 J/cm3 together with an efficiency (η) of 87 % was achieved for the x = 0.04 ceramic at 360 kV/cm. Furthermore, excellent energy storage properties (W rec ≥ 2.71 J/cm3, η ≥ 85 %) were obtained over a wide range of temperatures (20–200 ℃), frequencies (0.5–100 Hz) and cycle numbers (105) under 260 kV/cm, indicating good thermal stability, frequency-independent character and fatigue-resistance behavior. Our work would open up a new avenue for preparing BKT-based dielectric ceramics. • Composition modulation was adopted to design Bi 0.5 K 0.5 TiO 3 -based ceramics. • An excellent W rec of 4.25 J/cm3 along with η of 87 % at 360 kV/cm was achieved. • The ceramic displayed good thermal, frequency and cycle stability. [ABSTRACT FROM AUTHOR]