US5342704A
Expired / Lapsed
US
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Method of making an air electrode material having controlled sinterability
Assignee: Siemens Energy Inc
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Filing: 1993-12-02
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Granted: 1994-08-30
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Expires: 2013-12-02
Abstract
Abstract A tubular, porous ceramic electrode structure (3) is made from the sintered admixture of doped lanthanum manganite and an additive containing cerium where a solid electrolyte (4), substantially surrounds the air electrode, and a porous outer fuel electrode (7) substantially surrounds the electrolyte, to form a fuel cell (1).
Inventors
- 👤 Theodore R. Vasilow
- 👤 Lewis J. H. Kuo
- 👤 Roswell J. Ruka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:14
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/90; H01M4/9016; H01M4/9025; H01M4/9033; H01M4/02; H01M4/04; C; C04; C04B; C04B35/00; C04B35/01; C04B35/016; H01M10/00; H01M10/36; H01M4/8605; H01M4/8621; H01M2004/8678; H01M2004/8689; H01M8/00; H01M8/10; H01M8/12; H01M2008/1293; H01M2300/00; H01M2300/0017; H01M2300/0065; H01M2300/0068; H01M2300/0071; H01M2300/0074; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02E60/30; Y02E60/50
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
115 words
A method of making a porous ceramic electrode structure comprising the steps of: A) admixing: 1) lanthanum manganite doped with an element selected from the group consisting of calcium, strontium, chromium, and mixtures thereof, and 2) cerium additive powder selected from the group consisting of cerium oxide, cerium carbonate, cerium nitrate, cerium acetate, cerium oxalate, and mixtures thereof, where cerium is present in the admixture in the range of from 0.02 mole to 0.04 mole per mole of doped lanthanum manganite; B) shaping the admixture into an electrode structure; C) sintering the shaped structure in air to form a porous, solid electrode, where the shaped structure maintains a porosity over 20% through the sintering step.
Claim 2
Independent Claim
115 words
A method of making a porous ceramic electrode structure comprising the steps of: A) admixing: 1) lanthanum manganite doped with an element selected from the group consisting of calcium, strontium, chromium, and mixtures thereof, and 2) cerium additive powder selected from the group consisting of cerium oxide, cerium carbonate, cerium nitrate, cerium acetate, cerium oxalate, and mixtures thereof, where cerium is present in the admixture in the range of from 0.02 mole to 0.04 mole per mole of doped lanthanum manganite; B) shaping the admixture into an electrode structure; C) sintering the shaped structure in air to form a porous, solid electrode, where the shaped structure maintains a porosity over 20% through the sintering step.
Claim 3
Dependent Claim
16 words
The method of claim 1, where the admixture is shaped into a tube in step (B).
Claim 4
Dependent Claim
11 words
The method of claim 1, where the additive is cerium oxide.
Claim 5
Dependent Claim
37 words
The method of claim 1, where the lanthanum manganite is a powder and has particle size diameters from about 0.2 micrometers to 100 micrometers and the additive has particle size diameters from 0.1 micrometer to 2.0 micrometers.
Claim 6
Dependent Claim
62 words
The method of claim 1, where after sintering in step (C), to provide an air electrode of from 20% to 40% porosity, a gas tight solid electrolyte is applied to substantially surround the outer periphery of the air electrode, and then a porous outer fuel electrode is applied to substantially surround the outer periphery of the electrolyte, to form a fuel cell.
Claim 7
Dependent Claim
20 words
The method of claim 1, where the cerium additive is effective during sintering in step (C) to prevent excess densification.
Claim 8
Dependent Claim
16 words
The method of claim 1, where the electrode structure is shaped by extrusion or isostatic pressing.
Claim 9
Dependent Claim
49 words
The method of claim 1, where the doped lanthanum manganite has the formula La 1-x (M) x MnO 3 , where M is at least one of Ca, Sr, and Cr present in a total amount of x=0.2 to 0.4 and where La+M is approximately between 0.960 and 0.995.
References Cited (Backward Citations)
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| 3.5 Years (Year 4) | 1997-08-29 | 1998-02-28 | 1998-08-30 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2001-08-29 | 2002-02-28 | 2002-08-30 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2005-08-29 | 2006-02-28 | 2006-08-30 | $7700.00 | Window Closed / Lapsed |