Owing to the merits of giant power density and ultrafast charge–discharge time, dielectric capacitors including ceramics and films have inspired increasing interest lately. Nevertheless, the energy storage density of dielectric ceramics should be further optimized to cater to the boosting demand for the compact and portable electronic devices. Herein, an ultrahigh recoverable energy storage density W rec of 13.44 J/cm3 and a high efficiency η of 90.14% are simultaneously realized in BiFeO3–BaTiO3–NaTaO3 relaxor ferroelectric ceramics with high polarization P max, reduced remanent polarization P r, and optimized electric breakdown strength E b. High P max originates from the genes of BiFeO3-based ceramics, and reduced P r is induced by enhanced relaxor behavior. Particularly, a large E b is achieved by the synergic contributions from complicated internal and external factors, such as decreased grain size and improved resistivity and electrical homogeneity. Furthermore, the ceramics also exhibit satisfactory frequency, cycling and thermal reliability, and decent charge–discharge property. This work not only indicates that the BiFeO3-based relaxor ferroelectric materials are promising choices for the next-generation electrostatic capacitors but also paves a potential approach to exploit novel high-performance dielectric ceramics.
Ceramic capacitors with high electrostatic energy storage performances have captured much research interest in latest years. Sodium bismuth titanate (Na0.5Bi0.5TiO3)‐based ferroelectric ceramics show great potential due to their environment‐friendly composition, high polarization, and excellent relaxor properties. However, the nonergodic relaxor state of Na0.5Bi0.5TiO3‐based ceramics hampers the decrement of remanent polarization, leading to poor energy storage performance. Herein, the (1 − x)Na0.5Bi0.5TiO3–xLa(Ni2/3Ta1/3)O3 ceramics were designed to generate the transformation between nonergodic and ergodic relaxor state. As a result, the ceramics exhibit improved dielectric relaxation, slim polarization–electric field loops, and flattened current–electric field curves due to highly dynamic polar nanoregions. Particularly, the 0.85Na0.5Bi0.5TiO3–0.15La(Ni2/3Ta1/3)O3 ceramics show large breakdown electric field Eb (345 kV/cm), high recoverable energy density Wrec (3.6 J/cm3), and efficiency η (80.6%), revealing potential applications in electrostatic energy storage.
Dielectric capacitors have become an important component in current pulsed power devices and thus have attracted great research interest in recent years. Among all kinds of dielectric materials, the bismuth ferrite (BiFeO 3 )-based ceramic capacitors show possible applications in dielectric energy storage because of their large polarization. However, the relatively high conductivity badly limits the improvement of electric breakdown strength, thus leading to low energy density. Herein, the perovskite end-member La(Mg 2/3 Nb 1/3 )O 3 and sintering aid MnO 2 were simultaneously introduced into BiFeO 3 −SrTiO 3 solid solutions to improve the relaxation features and electric breakdown strength. Accordingly, a high recoverable energy density of 6.3 J/cm 3 and an acceptable efficiency of 74.3% were realized under 450 kV/cm. In addition, the good frequency/thermal stability and superior charge−discharge performances were also realized. This work provides feasible approaches to modify the capacitive energy storage of BiFeO 3 -based relaxor ferroelectric ceramics.
Ceramic-based dielectric capacitors have become an attractive issue due to their wide applications in current pulsed-/high-power electronic devices. Antiferroelectric ceramics generally exhibit ultrahigh energy density owing to their giant polarization activated by antiferroelectric–ferroelectric phase transition under a high electric field but suffer from large hysteresis, meanwhile giving rise to low efficiency. Herein, by introducing perovskite compound Sr(Fe0.5Ta0.5)O3 into an antiferroelectric NaNbO3 matrix, a stabilized antiferroelectric phase and an improved relaxor behavior are observed. That is, relaxor antiferroelectric ceramics are constructed. Accordingly, a double polarization–electric field ( P–E) loop becomes slimmer with increasing incorporation of dopants, leading to an ultrahigh recoverable energy density of 11.5 J/cm3, an energy storage efficiency of 86.2%, outstanding frequency/cycling/thermal reliability, and charge–discharge properties in 0.90NaNbO3-0.10Sr(Fe0.5Ta0.5)O3 ceramics. This work reveals that inducing the relaxor behavior in antiferroelectric materials is an effective route to improve their capacitive energy storage.
Antiferroelectric ceramics are recently, a research hotspot for electrostatic energy storage because of their large electric‐field induced polarization. Lead‐free sodium niobate (NaNbO3)‐based ceramics are one of the emerging antiferroelectric counterparts. However, the unstable antiferroelectric phase seriously restricts the further improvement of energy density and efficiency. In this work, by introducing binary perovskite end‐member BiFeO3–BaTiO3 with lower tolerance factor and average electronegativity into NaNbO3 ceramics, the stablized antiferroelectric phase with improved relaxation characteristic is identified by slim double‐like polarization‐electric field (P–E) loops and four‐peak current–electric field (I–E) curves. Meanwhile, the antiferroelectric P to R phase transition is verified through Raman spectra, X‐ray diffraction (XRD) patterns, and dielectric performance. In particular, the enhanced electric breakdown strength Eb is achieved by synergic contributions from ultralow dielectric loss, reduced grain size, and so on. Consequently, the sample with optimized composition displays ultrahigh recoverable energy storage density (Wrec) of 14.5 J cm−3 and satisfied efficiency (η) of 83.9%, which shows the superiority in the state‐of‐the‐art dielectric ceramics. These results provide a feasible route by regulating the relationship between antiferroelectric structure and properties to explore high‐performance dielectrics for electrostatic energy storage applications.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.