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The primary challenges in relaxor ferroelectric ceramics are their high energy dissipation, low energy storage density, and reliance on strong electric fields, which hinder their excellent energy storage under low electric fields. Herein, we fabricated the (1−x)(0.75Na0.5Bi0.5TiO3−0.25SrTiO3)−xBi2/3(Nb0.5Al0.5)O3 ((1−x)NBST−xBNA) ceramics using the solid-state reaction method and comprehensively investigated phase structures, microstructure, dielectric properties, relaxation properties, breakdown properties, and energy storage properties through experimental and simulation methods. By utilizing modulable dielectric properties and fine grain size effect, the optimized component (x = 0.05) achieved an improved energy storage density of 2.32 J/cm3 and an outstanding efficiency of 91.7% at the low electric field of 180 kV/cm. Further, the outstanding stability in frequency (1–200 Hz) and temperature (20–140 °C) at 100 kV/cm was achieved in 0.95NBST-0.05BNA ceramics. This indicates that these materials have immense potential for high-power energy storage applications. [ABSTRACT FROM AUTHOR]

Dielectrics with high‐energy‐storage performance are highly desired for increasing compact‐size energy storage, and integration of modern power electronics. However, an ever‐existing challenge is to achieve both high efficiency (η) and high energy density (Ue). Here, a gradient‐layered (five‐layer) polyetherimide (PEI)‐based nanocomposite is presented. Different from traditional layered structures (modulation of filler volume fraction), multistage gradient interfaces are constructed by modulating the particle sizes of barium titanate nanoparticles (BaTiO3 NPs) to decrease sequentially from top to bottom. In this structure, three BaTiO3 NPs/PEI layers are clamped by two boron nitride nanosheets (BNNSs)/PEI layers. It is demonstrated that the gradient structure can suppress breakdown and confer high interfacial polarization, simultaneously. Consequently, the nanocomposite possesses an enhanced Ue of 16.38 J cm−3, and an ultrahigh η of 97.79%, far exceeding previously reported polymer nanocomposites. Furthermore, this nanocomposite also demonstrates satisfactory high‐temperature energy storage performances, achieving a Ue of 7.36 J cm−3 and an η of 83.12% at 150 °C. This gradient layered structure design opens a new way to explore high‐performance dielectric polymer nanocomposite with both ultrahigh Ue and η. [ABSTRACT FROM AUTHOR]

The combustion of fuel with high sulfur concentrations produces a large number of sulfur oxides (SOx), which have a range of negative effects on human health and life. The preparation of catalysts with excellent performance in the oxidative desulfurization (ODS) process is highly effective for reducing SOx production. In this paper, cross-linked polyvinylimidazole (VE) was successfully created using a simple ontology aggregation method, after which a catalyst of polyvinylimidazolyl heteropolyacid clusters (VE-HPA) was prepared by adding heteropolyacid clusters. Polyvinylimidazolyl-phosphotungstic acid (VE-HPW) showed an outstanding desulfurization performance, and the desulfurization efficiency reached 99.68% in 60 min at 50 °C with H2O2 as an oxidant. Additionally, the catalyst exhibited recyclability nine consecutive times and remained stable, with a removal rate of 98.60%. The reaction mechanism was eventually proposed with the assistance of the free radical capture experiment and GC-MS analysis. [ABSTRACT FROM AUTHOR]

Flexible thin film with both good ferroelectric and ferromagnetic properties has more extensive applications in the field of flexible and/or wearable devices and sensors. In this experiment, the flexible Bi0.9Gd0.1Fe0.98Mn0.02O3 (BGFMO) thin film is successfully deposited on fluorophlogopite (F-Mica) single-crystalline substrate by sol–gel method. The flexible BGFMO thin film exhibits a rhombohedrally distorted perovskite structure, uniform grain size, and a relatively smooth surface. It has good ferroelectricity, with a remnant polarization (Pr) value of 74.88 μC/cm2 and ferromagnetism with anisotropic saturation magnetization (in-plane saturation magnetization of about 32.00 emu/cm3, out-of-plane saturation magnetization of about 29.80 emu/cm3). The flexible thin film can maintain good ferroelectric properties at different frequencies and temperatures, and the ferroelectric properties can be adjusted by mechanical bending. Therefore, the flexible BGFMO thin film with excellent ferroelectric and ferromagnetic properties has great application potential in flexible electronic devices. [ABSTRACT FROM AUTHOR]

Wearable devices and flexible electronics have promoted the development of flexible thin film materials. Flexible films with excellent performance and adapted to the operating conditions of flexible electronic devices are required. Here, the flexible BiFe0.97Cr0.03O3/BiFe1−xMnxO3 (x = 0.05–0.09) ferroelectric thin films were successfully prepared on LaNiO3/fluorophlogopite (F-Mica) by the sol–gel method. The flexible BiFe0.97Cr0.03O3/BiFe0.93Mn0.07O3 (BFC0.03O/BFM0.07O) sample shows a best ferroelectricity with a real residual polarization value of 106.59 µC/cm2 was obtained from the Positive Up Negative Down (PUND). The flexible sample maintains true ferroelectric performance at different frequencies and shows excellent bending fatigue resistance after mechanical bending with 10000 cycles. The residual stress generated by mechanical bending increases the polarization of the flexible sample while maintaining the true ferroelectric polarization. The larger residual stress results in the enlargement of the defect. This provides an interesting approach to the ferroelectric regulation of flexible thin films. The flexible BiFe0.97Cr0.03O3/BiFe1−xMnxO3 thin films with excellent ferroelectricity and bending fatigue resistance are promising for the applications in high temperature flexible electronic components and sensors. [ABSTRACT FROM AUTHOR]

Ferroelectric ceramics have low energy storage performance due to their nearly square hysteresis loops and low dielectric breakdown strength, which affects their practical applications for high-power energy storage capacitors. Therefore, we solve this problem by introducing a linear dielectric additive and rare earth oxide into Na0.5Bi0.5TiO3-based ceramics. The (1 − x)(0.94Na0.5Bi0.5TiO3–0.06BaTiO3)–xCa0.7Sm0.2TiO3 [(1 − x)NBBT–xCST] ceramics were designed and prepared by the conventional solid-state reaction method. The results show that the introduction of Ca0.7Sm0.2TiO3 can effectively inhibit the grain growth, optimize the relaxation behavior and improve the band gap, which are conducive to the simultaneous enhancement of energy storage density and efficiency. The reliability of the experimental results is also verified by finite element simulation (COMSOL). A high recoverable energy density (Wrec) of 5.1 J cm−3, a high efficiency (η) of 88% and an ultrafast discharge time of 28 ns were finally achieved in NBBT ceramics with x = 0.35. Notably, the sample exhibits superior thermal stability over a wide temperature range of 20–140 °C. These properties provide a new design approach for energy storage capacitors. [ABSTRACT FROM AUTHOR]

Dielectric capacitors based on antiferroelectric ceramics are promising for applications in advanced high-power electric and electronic devices, for which more efforts should be devoted to enhancing the recoverable energy storage density and energy efficiency. In this work, a record-high recoverable energy storage density Wrec up to 9.0 J cm−3 and energy efficiency η of 90% are achieved in lead-free AgNbO3-based ceramics composed of antiferroelectric and paraelectric phases, which were realized by phase engineering via Bi-doping. Compared with pristine AgNbO3, the enhancement in recoverable energy storage density and energy efficiency reaches 621% and 241%, respectively. In addition, the breakdown strength Eb exceeds 650 kV cm−1 in 12 mol% Bi-doped 0.10 wt% MnO2–AgNbO3 ceramics, which greatly contributes to the exceptionally enhanced energy storage performance. The excellent performance could be retained at elevated temperatures, and various frequencies and cycles. Moreover, the discharge energy density Wd in direct-current charge–discharge performance reaches 8.0 J cm−3, which is also superior to those reported in other lead-free dielectric energy storage ceramics. The strategy can provide an applicable method to optimize energy storage performance and other functionalities of dielectric materials. [ABSTRACT FROM AUTHOR]

Poly(vinylidene fluoride) (PVDF)-based composite materials with high discharge energy density (Ue) represent a compelling option in the quest for high-performance dielectric capacitors. However, the existing PVDF-based composite materials are limited by their low breakdown electric field (Eb) and cannot satisfy the use of capacitors in extreme environments of ultrahigh voltages. Designing multilayer composite structures is a successful strategy to enhance the maximum Eb and Ue of PVDF-based composite films. In contrast to the traditional symmetric laminated structure, this paper innovatively proposes an asymmetric sandwich-structure PVDF-based nanocomposite film fabricated via the casting method, which is composed of a breakdown guiding layer with 0D BT powders, a breakdown buffer layer of P(VDF-HFP), and a breakdown cut-off layer with 2D BN nanosheets. The improved structure has significantly boosted the energy storage characteristics of the nanocomposite film. Specifically, adding 5 vol% 2D BN nanosheets to the breakdown cut-off layer enables the film to achieve an outstanding Ue of 22.72 J cm−3 at an extremely high Eb of 720 MV m−1. Finite element simulation provides support for the breakdown mechanism of the nanocomposite film. Ultimately, this study presents a novel strategy for the preparation of advanced dielectric capacitor materials. [ABSTRACT FROM AUTHOR]