Recent advances in lead-free dielectric materials for energy storage

Energy storage materials and their applications have attracted attention among both academic and industrial communities. Over the past few decades, extensive efforts have been put on the development of lead-free high-performance dielectric capacitors. In this review, we comprehensively summarize the research progress of lead-free dielectric ceramics for energy storage, including ferroelectric ceramics, composite ceramics, and multilayer capacitors. The results indicate that dielectric capacitors with both high energy density and high efficiency are feasible using the materials providing high breakdown electric field and a slim hysteresis loop. This article also lists the factors affecting the fabrication cost of dielectric capacitors, such as sintering temperature, raw material costs, and types of internal electrodes, to promote the industrial application of ceramic energy storage capacitors.

A review on the development of lead-free ferroelectric energy-storage ceramics and multilayer capacitors

The explosive process of 5G communication evokes the urgent demand of miniaturized and integrated dielectric ceramics filter. It is a pressing need to advance the development of dielectric ceramics utilization of emerging technology to design new materials and understand the polarization mechanism. This review provides the summary of the study of microwave dielectric ceramics (MWDCs) sintered higher than 1000 from 2010 up to now, °C with the purpose of taking a broad and historical view of these ceramics and illustrating research directions. To date, researchers endeavor to explain the structure-property relationship of ceramics with multitude of approaches and design a new formula or strategy to obtain excellent microwave dielectric properties. There are variety of factors that impact the permittivity, dielectric loss, and temperature stability of dielectric materials, covering intrinsic and extrinsic factors. Many of these factors are often intertwined, which can complicate new dielectric material discovery and the mechanism investigation. Because of the various ceramics systems, pseudo phase diagram was used to classify the dielectric materials based on the composition. In this review, the ceramics were firstly divided into ternary systems, and then brief description of the experimental probes and complementary theoretical methods that have been used to discern the intrinsic polarization mechanisms and the origin of intrinsic loss was mentioned. Finally, some perspectives on the future outlook for high-temperature MWDCs were offered based on the synthesis method, characterization techniques, and significant theory developments.

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The latest process and challenges of microwave dielectric ceramics based on pseudo phase diagrams

(1 − x)Pb(Mg1/3Nb2/3)O3−xPbTiO3 (x = 0, 5, and 10 mol%) ceramics were prepared using a conventional mixed oxide solid state reaction method. The low-temperature relaxor behavior of (1 − x)Pb(Mg1/3Nb2/3)O3–xPbTiO3 ceramics were examined in the temperature range from 120 to 523 K. A broad dielectric maximum that shifted to higher temperatures with increasing frequency, signified the relaxor-type behavior of these ceramics. The value of the relaxation parameter γ = 1.61–1.94 estimated from the linear fit of the modified Curie–Weiss law indicated the relaxor nature. High-temperature dielectric relaxation phenomena were found in the temperature region 600–850 K. Energy-storage properties were also analyzed, and the energy-storage density calculated from hysteresis loops reached about 0.47 J cm−3 at room temperature.

https://iopscience.iop.org/article/10.1088/0022-3727/49/9/095302/pdf

Energy-storage properties and high-temperature dielectric relaxation behaviors of relaxor ferroelectric Pb(Mg1/3Nb2/3)O3–PbTiO3 ceramics

The unique properties and great variety of relaxer ferroelectrics make them highly attractive in energy-storage and solid-state refrigeration technologies. In this work, lanthanum modified lead titanate ceramics are prepared and studied. The giant electrocaloric effect in lanthanum modified lead titanate ceramics is revealed for the first time. Large refrigeration efficiency (27.4) and high adiabatic temperature change (1.67 K) are achieved by indirect analysis. Direct measurements of electrocaloric effect show that reversible adiabatic temperature change is also about 1.67 K, which exceeds many electrocaloric effect values in current direct measured electrocaloric studies. Both theoretical calculated and direct measured electrocaloric effects are in good agreements in high temperatures. Temperature and electric field related energy storage properties are also analyzed, maximum energy-storage density and energy-storage efficiency are about 0.31 J/cm3 and 91.2%, respectively.

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Enhanced electrocaloric analysis and energy-storage performance of lanthanum modified lead titanate ceramics for potential solid-state refrigeration applications.

Optical and electrical properties of ferroelectric Bi0.5Na0.5TiO3-NiTiO3 semiconductor ceramics

Mn-doped 0.97Bi0.47Na0.47Ba0.06TiO3–0.03K0.5Na0.5NbO3 (BNBT–KNN) lead-free energy storage ceramics were prepared by the conventional solid-state reaction methods. Effects of Mn addition on the microstructures and energy storage properties of the ceramics were investigated. XRD analysis revealed that all the ceramics possessed a single perovskite structure. As the Mn content arose from 0 to 3 mol. %, the average grain size of the BNBT–KNN ceramics increased by nearly 4 times (from ~1.6 to ~6.2 µm). The energy storage density of the BNBT–KNN ceramics firstly increased and then decreased with increment of Mn addition. With the rise of external electric field loaded on the ceramics, the energy storage density increased drastically, and a maximum value of 0.938 J/cm3 at 79 kV/cm was achieved by the BNBT–KNN samples with 1.0 mol. % Mn content.

Microstructures and energy storage properties of Mn-doped 0.97Bi0.47Na0.47Ba0.06TiO3–0.03K0.5Na0.5NbO3 lead-free antiferroelectric ceramics

In this work, the (1−x)Bi0.5Na0.5TiO3-xBaNi0.5Nb0.5O3 (BNT-BNN; 0.00 ⩽ x ⩽ 0.20) ceramics were prepared via a high-temperature solid-state method. The crystalline structures, photovoltaic effect, and electrical properties of the ceramics were investigated. According to X-ray diffraction, the system shows a single perovskite structure. The samples show the normal ferroelectric loops. With the increase of BNN content, the remnant polarization (Pr) and coercive field (Ec) decrease gradually. The optical band gap of the samples narrows from 3.10 to 2.27 eV. The conductive species of grains and grain boundaries in the ceramics are ascribed to the double ionized oxygen vacancies. The open-circuit voltage (Voc) of ∼15.7 V and short-circuit current (Jsc) of ∼1450 nA/cm2 are obtained in the 0.95BNT-0.05BNN ceramic under 1 sun illumination (AM1.5G, 100 mW/cm2). A larger Voc of 23 V and a higher Jsc of 5500 nA/cm2 are achieved at the poling field of 60 kV/cm under the same light conditions. The study shows this system has great application prospects in the photovoltaic field.

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Liufang Meng

Papers

Optical and electrical properties of ferroelectric Bi0.5Na0.5TiO3-NiTiO3 semiconductor ceramics

Microstructures and energy storage properties of Mn-doped 0.97Bi0.47Na0.47Ba0.06TiO3–0.03K0.5Na0.5NbO3 lead-free antiferroelectric ceramics

Photocurrent density and electrical properties of Bi0.5Na0.5TiO3-BaNi0.5Nb0.5O3 ceramics

Electrical microstructures of CaTiO3-Bi0.5Na0.5TiO3 microwave ceramics with high permittivity (εrmax ∼487)

High photocurrent densities in Bi0.5Na0.5TiO3 ferroelectric semiconductors