Patent US5122487A successfully refreshed from Google Patents.
US5122487A
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US
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Solid electrolyte of partially stabilized zirconia and method of producing same
Assignee: Niterra Co Ltd
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Filing: 1991-02-04
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Granted: 1992-06-16
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Expires: 2011-02-04
Abstract
Abstract As a solid electrolyte suitable for use in oxygen sensors a partially stabilized zirconia, which essentially consists of 4.5-6.0 mol % of Y 2 O 3 and the balance of ZrO 2 and is constituted of tetragonal and cubic crystals, is produced by using a coprecipitated powder of a solid solution of ZrO 2 and Y 2 O 3 as the raw material and performing sintering of a green body at a temperature not higher than 1500° C. The ZrO 2 -Y 2 O 3 powder has a mean particle size not larger than 1 μm and a specific surface area in the range from 2.5 to 7 m 2 /g and is required to be not more than 0.2 wt % in the content of unwanted SiO 2 so that the sintered solid electrolyte may be as low as possible in the content of SiO 2 . The obtained solid electrolyte has good mechanical properties and exhibits sufficiently high withstand voltage.
Inventors
- 👤 Nobuhiro Hayakawa
- 👤 Hiroyuki Ishiguro
- 👤 Takeshi Kitano
- 👤 Yutaka Adachi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 17:06
CPC Classifications
G; G01; G01N; G01N27/00; G01N27/26; G01N27/403; G01N27/406; G01N27/407; G01N27/4073; C; C04; C04B; C04B35/00; C04B35/01; C04B35/48; C04B35/486; H; H01; H01M; H01M8/00; H01M8/10; H01M8/12; H01M8/124; H01M8/1246; H01M8/1253; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
169 words
A method of producing an oxygen ion conductive solid electrolyte which is a sintered solid solution of ZrO 2 and Y 2 O 3 consisting essentially of 15-60 wt % of tetragonal crystal grains and the balance of cubic crystal grains, wherein the molar ratio of Y 2 O 3 to ZrO 2 is in the range from 4.5:95.5 to 6.0:94.0, the method comprising the steps of: mixing a powder of a solid solution of 4.5 to 6.0 mol % of Y 2 O 3 and the balance of ZrO 2 prepared by a coprecipitation process with a binder and forming the resulting mixture into a green body of a desired shape, said powder having a mean particle size not larger than 1.0 μm and a specific surface area in the range from 2.5 to 7 m 2 /g and not more than 0.2 wt % in the content of SiO 2 as an inevitable impurity; and sintering said green body at a temperature not higher than 1500° C.
Claim 2
Independent Claim
169 words
A method of producing an oxygen ion conductive solid electrolyte which is a sintered solid solution of ZrO 2 and Y 2 O 3 consisting essentially of 15-60 wt % of tetragonal crystal grains and the balance of cubic crystal grains, wherein the molar ratio of Y 2 O 3 to ZrO 2 is in the range from 4.5:95.5 to 6.0:94.0, the method comprising the steps of: mixing a powder of a solid solution of 4.5 to 6.0 mol % of Y 2 O 3 and the balance of ZrO 2 prepared by a coprecipitation process with a binder and forming the resulting mixture into a green body of a desired shape, said powder having a mean particle size not larger than 1.0 μm and a specific surface area in the range from 2.5 to 7 m 2 /g and not more than 0.2 wt % in the content of SiO 2 as an inevitable impurity; and sintering said green body at a temperature not higher than 1500° C.
Claim 3
Dependent Claim
19 words
A method according to claim 1, wherein said content of SiO 2 is not more than 0.1 wt %.
Claim 4
Dependent Claim
22 words
A method as claimed in claim 1, wherein the molar ratio of Y 2 O 3 to ZrO 2 is about 5.5:94.5.
Claim 5
Dependent Claim
19 words
A method as claimed in claim 1, wherein the mean particle size is not larger than about 0.5 μm.
Claim 6
Dependent Claim
17 words
A method as claimed in claim 1, wherein the specific surface is about 3.3 m 2 /g.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1995-06-16 | 1995-12-16 | 1996-06-16 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1999-06-16 | 1999-12-16 | 2000-06-16 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2003-06-16 | 2003-12-16 | 2004-06-16 | $7700.00 | Window Closed / Lapsed |