EP0337036A1
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EP
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A method for bonding a conductive layer on an electrode structure
Assignee: Westinghouse Electric Corp
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Filing: 1988-12-30
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Granted: —
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Expires: 2008-12-30
Abstract
Abstract A dense, electronically conductive interconnection layer (26) is bonded on a porous, tubular, electronically conductive air electrode structure (16), optionally supported by a ceramic support (22), by (A) forming a layer of oxide particles of at least one of the metals Ca, Sr, Co, Ba or Mg on a part (24) of a first surface of the air electrode (16), (B) heating the electrode structure, (C) applying a halide vapor containing at least lanthanum halide and chromium halide to the first surface and applying a source of oxygen to a second opposite surface of the air electrode so that they contact at said first surface, to cause a reaction of the oxygen and halide and cause a dense lanthanum-chromium oxide structure to grow, from the first electrode surface, between and around the oxide particles, where the metal oxide particles get incorporated into the lanthanum-chromium oxide structure as it grows thicker with time, and the metal ions in the oxide particles diffuse into the bulk of the lanthanum-chromium oxide structure, to provide a dense, top, interconnection layer (26) on top of the air electrode (16).
Inventors
- 👤 Uday Bhanu Pal
- 👤 David Murdock Moon
- 👤 Subhash Chandra Singhal
- 👤 George Robert Folser
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-26 10:19
CPC Classifications
H; H01; H01M; H01M4/00; H01M4/86; H01M4/88; C; C23; C23C; C23C16/00; C23C16/06; C23C16/08; H01M8/00; H01M8/10; H01M8/12; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108; Y10T29/49115
Claims Analysis
Total Claims: 11
Claim 1
Independent Claim
210 words
A method of bonding a dense, electronically conductive layer (26) on a porous, electronically conductive electrode structure (16) characterized by the steps: (A) forming a layer of discrete metal oxide particles, where the metal is selected from the group consisting of Ca, Sr, Co, Ba, Mg, and mixtures thereof, on a portion of a first surface of a porous, electronically conductive, metal oxide electrode structure; (B) heating the electrode structure; and (C) applying metal halide vapor, comprising lanthanum halide and chromium halide, to said first surface of the porous electrode structure, and applying a source of oxygen to a second, opposite surface of the porous electrode structure, in a manner effective that oxygen contacts the metal halide vapor at said first surface of the porous electrode structure, to cause a reaction of the oxygen with the metal halide vapor, and cause a dense, lanthanum-chromium oxide structure to grow from the first electrode surface, between and around the metal oxide particles, where metal oxide particles get incorporated into the lanthanum-chromium oxide structure as it grows thicker with time, and the metal ion component of the incorporated metal oxide particles diffuse into the bulk of the lanthanum-chromium oxide structure; to provide a dense, top, electronically conductive layer on the porous electrode structure.
Claim 2
Independent Claim
210 words
A method of bonding a dense, electronically conductive layer (26) on a porous, electronically conductive electrode structure (16) characterized by the steps: (A) forming a layer of discrete metal oxide particles, where the metal is selected from the group consisting of Ca, Sr, Co, Ba, Mg, and mixtures thereof, on a portion of a first surface of a porous, electronically conductive, metal oxide electrode structure; (B) heating the electrode structure; and (C) applying metal halide vapor, comprising lanthanum halide and chromium halide, to said first surface of the porous electrode structure, and applying a source of oxygen to a second, opposite surface of the porous electrode structure, in a manner effective that oxygen contacts the metal halide vapor at said first surface of the porous electrode structure, to cause a reaction of the oxygen with the metal halide vapor, and cause a dense, lanthanum-chromium oxide structure to grow from the first electrode surface, between and around the metal oxide particles, where metal oxide particles get incorporated into the lanthanum-chromium oxide structure as it grows thicker with time, and the metal ion component of the incorporated metal oxide particles diffuse into the bulk of the lanthanum-chromium oxide structure; to provide a dense, top, electronically conductive layer on the porous electrode structure.
Claim 3
Dependent Claim
31 words
A method according to claim 1, characterized in that the metal oxide particles are CaO particles having a diameter of less than about 15 microns, and the electrode structure is tubular.
Claim 4
Dependent Claim
75 words
A method according to claim 1, characterized in that the halides applied in step (C) are lanthanum chloride and chromium chloride, heating in step (B) is over 1,000°C, the porous electrode structure is an air electrode, the electronically conductive layer is an interconnection layer, solid electrolyte is applied to the uncovered portion of the first surface of the air electrode, and a fuel electrode is applied to the solid electrolyte, to provide an electrochemical cell.
Claim 5
Dependent Claim
27 words
A method according to claim 1, characterized in that the metal oxide particles are formed in step (A) by heating the corresponding metal carbonate, sulfate or nitrate.
Claim 6
Dependent Claim
82 words
A method according to of claim 1, characterized in that the coverage of the metal oxide particles on the electrode structure is an amount effective to allow metal halide vapor to contact the first surface of the porous electrode structure and react with oxygen, and where the incorporated metal ions contribute oxygen vacancies in step (C) and enhance oxygen transport, causing an increase of the growth rate, sealing of the electrode structure, and reduction of chromium halide contact with the electrode structure.
Claim 7
Dependent Claim
49 words
A method according to claim 1, characterized in that after step (c) the lanthanum-chromium oxide is heat annealed in air, at a temperature and for a time effective to further cause the metal component of the metal oxide particles to diffuse throughout the bulk of the lanthanum-chromium oxide structure.
Claim 8
Dependent Claim
78 words
A method according to claim 1, characterized in that in step (C), hydrogen gas is used with the halide vapor at from 1,300°C to 1,450°C for ½ hour to 2 hours to grow the lanthanum-chromium oxide structure, and then the structure is annealed in air at 1,100°C to 1,400°C for 1 hour to 12 hours, where the annealing is effective to cause bulk diffusion of the metal component of the metal oxide particles throughout the lanthanum-chromium oxide structure.
Claim 9
Dependent Claim
43 words
A method according to claim 1, characterized in that in step (C) magnesium halide vapor is also applied, so that a magnesium doped lanthanum chromite top conductive layer is formed, and where the porous electrode structure is composed of strontium doped lanthanum manganite.
Claim 10
Dependent Claim
69 words
A method according to claim 7, characterized in that after the lanthanum-chromium oxide structure is grown, and before annealing, a layer of metal oxide particles, where the metal is selected from the group consisting of Ca, Sr, Co, Mg, and mixtures thereof, are formed on top of the grown lanthanum-chromium oxide structure, and the metal ions in the metal oxide diffuse into the bulk of the lanthanum-chromium oxide structure.
Claim 11
Dependent Claim
15 words
A least two electrochemical cells made by the method of claim 1, electronically connected together.
References Cited (Backward Citations)
EP0188056A1
Cited
US4631238A
Cited
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