Positive electrode active material and preparation method thereof, positive electrode plate, secondary battery, battery module, battery pack, and electric apparatus
US-2024429384-A1 · Dec 26, 2024 · US
HIGH BREAKDOWN STRENGTH FERROELECTRIC SrHf03 MATERIALS
US2019229258A1 · US · A1
| Field | Value |
|---|---|
| Publication number | US-2019229258-A1 |
| Application number | US-201916255069-A |
| Country | US |
| Kind code | A1 |
| Filing date | Jan 23, 2019 |
| Priority date | Jan 23, 2018 |
| Publication date | Jul 25, 2019 |
| Grant date | — |
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Abstract
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Methods for making metastable lead-free piezoelectric materials are presented herein.
First claim
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What is claimed is: 1 . A lead-free piezoelectric material capable of maintaining a piezoelectric response (d 33 ) of greater than about 5.2 pm V −1 when subjected to an electric field of about 25 MV/cm. 2 . The material of claim 1 that is capable of a piezoelectric response (e 33 ) of at least 8.8 C m −2 . 3 . The material of claim 1 having an average coercive field of about 83 kVcm −1 and a remnant polarization of about 1.2 μCcm −2 . 4 . The material of claim 1 comprising a metastable polymorph of SrHfO 3 . 5 . The material of claim 4 wherein the polymorph comprises a P4mm phase. 6 . The material of claim 4 having a e ij max of greater than 3 C m −2 . 7 . The material of claim 4 which is ferroelectric. 8 . A ferroelectric induced piezoelectric material having a piezoelectric response (d 33 ) of greater than about 5.2 pm V −1 wherein the piezoelectric material comprises a metastable SrHfO 3 polymorph with a P4mm structure. 9 . The material of claim 8 wherein the polymorph has a breakdown strength of greater than about 25 MV/cm. 10 . The material of claim 8 wherein the polymorph is capable of a piezoelectric response (e 33 ) of at least 8.8 C m −2 . 11 . The material of claim 8 wherein the polymorph is grown on a substrate suitable for epitaxial growth of the polymorph. 12 . The material of claim 8 having an average coercive field of about 83 kVcm −1 and a remnant polarization of about 1.2 μCcm −2 . 13 . The material of claim 8 wherein the polymorph is epitaxially stabilized by a substrate upon which the polymorph is grown. 14 . The polymorph of claim 11 wherein the substrate is SrTiO 3 . 15 . A method for making a lead-free piezoelectric material comprising the steps of identifying a lead-free piezoelectric material having a piezoelectric tensor (e ij max ) of greater than 3 C m −2 by using density functional theory (DFT); and identifying a substrate that is capable of epitaxially stabilizing the piezoelectric material. 16 . The method of claim 15 comprising using pulsed laser deposition to grow epitaxial films from a SrHfO 3 target on a SrTiO 3 substrate. 17 . The method of claim 16 wherein the growth takes place at a temperature of greater than about 450° C. 18 . The method of claim 16 wherein the growth takes place at a total pressure of about 100 mTorr oxygen. 19 . The method of claim 16 wherein the growth takes place by using a pulse rate of the laser of between about 10 and about 40 Hz. 20 . The method of claim 16 wherein the lead-free piezoelectric material has a breakdown strength of greater than about 25 MV/cm. 21 . The method of claim 16 wherein the lead-free piezoelectric material is a film that is capable of a ferroelectric-induced large signal effective converse piezoelectric response of 5.2 pm V −1 . 22 . The method of claim 16 wherein the lead-free piezoelectric material has a response of 5.2 pm V −1 for a 35 nm film, wherein the film comprises a metastable SrHfO 3 polymorph with a P4mm structure. 23 . The method of claim 16 wherein the lead-free piezoelectric material has an average coercive field of about 83 kVcm −1 and a remnant polarization of about 1.2 μCcm −2 .
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Heating of the material to be evaporated · CPC title
defined by measured X-ray, neutron or electron diffraction data · CPC title
Compounds of hafnium · CPC title
characterised by the substrate · CPC title
Other crystal-structural characteristics not specified above · CPC title
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- What does patent US2019229258A1 cover?
- Methods for making metastable lead-free piezoelectric materials are presented herein.
- Who is the assignee on this patent?
- Alliance Sustainable Energy, Lawrence Berkeley Nat Laboratory, Penn State Res Found
- What technology area does this patent fall under?
- Primary CPC classification C30B29/22. Mapped technology areas include Chemistry & Metallurgy.
- When was this patent published?
- Publication date Thu Jul 25 2019 00:00:00 GMT+0000 (Coordinated Universal Time) (A1). Legal status and post-grant events are not shown on this page.
- What related patents are in patentsdb?
- We list 8 related publications on this page (citations in our corpus or others sharing the same primary CPC).