Single‐Crystalline BaZr_0.2Ti_0.8O₃ Membranes Enabled High Energy Density in PEI‐Based Composites for High‐Temperature Electrostatic Capacitors

Abstract

Dielectric capacitors are promising for high power energy storage, but their breakdown strength (Eb) and energy density (Ue) usually degrade rapidly at high temperatures. Adding boron nitride (BN) nanosheets can improve the Eb and high‐temperature endurance but with a limited Ue due to its low dielectric constant. Here, freestanding single‐crystalline BaZr0.2Ti0.8O3 (BZT) membranes with high dielectric constant are fabricated, and introduced into BN doped polyetherimide (PEI) to obtain laminated PEI–BN/BZT/PEI–BN composites. At room temperature, the composite shows a maximum Ue of 17.94 J cm−3 at 730 MV m−1, which is more than two times the pure PEI. Particularly, the composites exhibit excellent dielectric‐temperature stability between 25 and 150 °C. An outstanding Ue = 7.90 J cm−3 is obtained at a relatively large electric field of 650 MV m−1 under 150 °C, which is superior to the most high‐temperature dielectric capacitors reported so far. Phase‐field simulation reveals that the depolarization electric field generated at the BZT/PEI–BN interfaces can effectively reduce carrier mobility, leading to the remarkable enhancement of the Eb and Ue over a wide temperature range. This work provides a promising and scalable route to develop sandwich‐structured composites with prominent energy storage performances for high‐temperature capacitive applications.

Multilayer nanocomposites with ultralow loadings of nanofillers exhibiting superb capacitive energy storage performance

“…5b. 9,11–13,17,18,20,22,37–53 Notably, the ultrahigh U d of 25.1 J cm −3 at η > 90% achieved in the 0.2-2-0.2 multilayer nanocomposite film exceeds the state-of-the-art, 1,6,7,23,37,41–43,54–65 e.g. , ferroelectric polymer-based BaTiO 3 @TiO 2 nanofibers/P(VDF-HFP) ( U d of 2.60 J cm −3 at η > 90%), 60 and BaTiO 3 @Al 2 O 3 @SiO 2 -montmorillonite nanosheets/P(VDF-HFP) ( U d of 0.80 J cm −3 at η > 90%), 57 linear polymer-based nanocomposites BNNS/crosslinked divinyltetramethyldisiloxane-bis(benzocyclobutene) ( U d of 2.36 J cm −3 at η > 90%), 1 and polyoxafluoronorbornene ( U d of 6.5 J cm −3 at η > 90%) 64 (Fig.…”

Electrode Effect on Ferroelectricity in Free-Standing Membranes of PbZr0.2Ti0.8O3

“…Unlike epitaxial complex oxide heterostructures, whose preparation imposes stringent requirements for the structural similarity between the constituent layers, ferroelectric oxide membranes can be easily integrated with the mainstream Si platform ,, and two-dimensional (2D) van der Waals materials , for developing flexible nanoelectronics, optics, and energy applications. ,, It also possesses distinct advantages compared with ferroelectric polymers and 2D van der Waals ferroelectrics for its high Curie temperature ( T C ), large polarization ( P ), and scalable synthesis. A wide range of device concepts have been realized based on ferroelectric oxide membranes, including ferroelectric tunnel junctions, ,, ferroelectric field effect transistors (FETs), reconfigurable optical filters, DW memories, and supercapacitors …”

“…A wide range of device concepts have been realized based on ferroelectric oxide membranes, including ferroelectric tunnel junctions, 16,17,24 ferroelectric field effect transistors (FETs), 19 reconfigurable optical filters, 18 DW memories, 25 and supercapacitors. 26 This article is licensed under CC-BY-NC-ND 4 For perovskite oxides, the type of electrode has a significant impact on T C , polarization dynamics, domain formation, and size scaling because the ferroelectric instability depends sensitively on the depolarization field, 27,28 strain, 29 and defect states. 30 These factors are strongly entangled in epitaxial thin films, 31 while free-standing membranes present an ideal platform to decouple the individual contributions of polarization screening, curvature induced flexoelectricity, lattice distortion, and interfacial epitaxy.…”

Improved energy storage performance in flexible (PbLa)ZrO3 thin films via nanocrystalline engineering

“…The technical difficulty of the ''two-step method'' is to select an appropriate sacrificial layer and etching solution. [16][17][18] (iii) Physical stripping method. Mechanical exfoliation after depositing thin films on layered substrates such as mica or laser lift-off is performed.…”