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Dielectric capacitors can store and release electric energy at ultrafast rates and are extensively studied for applications in electronics and electric power systems. Among various candidates, thin films based on relaxor ferroelectrics, a special kind of ferroelectric with nanometer-sized domains, have attracted special attention because of their high energy densities and efficiencies. We show that high-energy ion bombardment improves the energy storage performance of relaxor ferroelectric thin films. Intrinsic point defects created by ion bombardment reduce leakage, delay low-field polarization saturation, enhance high-field polarizability, and improve breakdown strength. We demonstrate energy storage densities as high as ~133 joules per cubic centimeter with efficiencies exceeding 75%. Deterministic control of defects by means of postsynthesis processing methods such as ion bombardment can be used to overcome the trade-off between high polarizability and breakdown strength.
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Lead-free bismuth pyrochlore-based dielectric films for ultrahigh energy storage capacitors
We developed ultra-high energy storage density capacitors using a new class of lead-free bismuth pyrochlorebased dielectric film material systems with high breakdown strength and reliability. The 2 μm-thick pyrochlore ceramic film capacitors have demonstrated ultra-high energy densities around 90 J/cm3 with very low energy loss below 3%, which is achieved by the combination of high permittivity, pseudo-linear dielectric characteristics, and high breakdown electric field over 4.5 MV/cm. Particularly, these pyrochlore ceramic films can endure voltage strength up to ~900 V. These noteworthy pyrochlore ceramic films are fabricated by the lowcost chemical solution deposition process which allows dielectric films to be processed on standard platinized silicon wafers. This new class of capacitors can satisfy the emergent needs for significant reduction in size and weight of capacitors with high energy storage capability in power electronics, electric vehicles, and energy storage in sustainable energy systems. Our research provides a unique and economical platform for the processing of this useful pyrochlore material in large volume for eco-friendly energy applications.
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- Award ID(s):
- 2044631
- PAR ID:
- 10608157
- Publisher / Repository:
- Elsevier Ltd
- Date Published:
- Journal Name:
- Materials Today Physics
- Volume:
- 33
- Issue:
- C
- ISSN:
- 2542-5293
- Page Range / eLocation ID:
- 101054
- Subject(s) / Keyword(s):
- Lead-free Pyrochlore dielectrics Film capacitor Pseudo-linearity Chemical solution deposition
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1016/j.mtphys.2023.101054
