Search

Energy storage capacitors for advanced pulse power systems and high-power electric devices is a kind of important electronic components, the demand continues to grow, specifications are constantly being upgraded, and performance boundaries are continuously being pushed. Multilayer ceramic capacitors (MLCCs) for energy storage applications have received increasing attention due to the advantages of ultralow equivalent series inductance, equivalent series resistance, good frequency characteristics, strong voltage overload ability, and stable operability at high temperatures. However, the relatively low energy storage density significantly limits its broader applications. Here, 0.4Ba 0.55 Sr 0.45 TiO 3 -0.4Bi 0.5 Na 0.5 TiO 3 -0.2SrZrO 3 (0.4BST-0.4BNT-0.2SZ) relaxor ferroelectric MLCCs are prepared at different heating rates. Excellent recoverable energy storage density of 10.3 J cm−3 and high energy efficiency of 93 % are achieved in fast-fired MLCCs under the electric field of 106.3 V μm−1. The impedance spectroscopy and thermally stimulated depolarization current technologies are employed to investigate the conductance mechanism of MLCCs, and the results can explain the effect of heating rate on the performance of MLCCs. In addition, the charge-discharge performances of fast-fired MLCCs are also thoroughly investigated, exhibiting great thermal and fatigue stability. [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]

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]

(Pb, La)(Zr, Sn, Ti)O 3 (PLZST) ceramic is one of the most prospective antiferroelectric (AFE) materials for variety of functional applications including energy storage and converter. Systematic structural investigation of domain structures should be of fundamental importance for understanding the structure-property relationship in AFE ceramics. In this study, the hierarchical domain structures and modulated structures correlated to the compositional variation in (Pb 0.97 La 0.02) (Zr 0.50 Sn x Ti 0.50-x)O 3 (x = 0.375, 0.45 and 0.50) were observed and investigated in details by transmission electron microscopy. The PLZST ceramics show exclusively incommensurate modulated structures (IMS) whose modulation period changed from 9.37 to 6.15 and to 4.04 with increasing of the x value. The hierarchical domain structures include, in decreasing scales, AFE domains, incommensurate domains and nanodomains. The elementary domains in PLZST ceramics are pinstriped nanodomains which were formed based on IMS configuration but by frequent modulation of IMS periodicity and formation of faults. Nanodomains accumulated and then dissociated into incommensurate domains and AFE domains successively. The presently revealed structural characteristics in antiferroelectric PLZST may stimulate future researches on the evolution of IMS-based hierarchical domains under external physical fields, e.g. thermal or electrical, and their correlation to the physical performance. [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]

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]