EP0454924A1
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EP
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Method of forming a thin layer of doped lanthanum chromite particles in a tape
Assignee: Westinghouse Electric Corp
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Filing: 1990-12-14
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Granted: —
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Expires: 2010-12-14
Abstract
Abstract A combustible polymer film, useful for application of an interconnection on an electrode is made by: (1) providing doped LaCrO₃ particles; (2) dispersing doped LaCrO₃ particles in a solvent, to provide a dispersion; (3) screening the dispersion to provide particles in the range of from 30 micrometers to 80 micrometers; (4) admixing a fugitive polymer with the particles; (5) casting the dispersion to provide a film; (6) drying the film; and (7) stripping the film. The film can then be applied to a porous, preheated electrode top surface, and then electrochemical vapor depositing a dense skeletal LaCrO₃ structure, between and around the doped LaCrO₃ particles. Additional solid oxide electrolyte and fuel electrode layers can then be added to provide a fuel cell.
Inventors
- 👤 Von Lee Richards
- 👤 Subhash Chandra Singhal
- 👤 Uday Bhanu C/O Dept. Of Materials Science & Pal
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-01 06:15
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/02; H01M8/0202; H01M8/0204; H01M8/0223; H01M8/0228; H01M8/0247; H01M8/0252; H01M8/10; H01M8/12; H01M2008/1293; H01M2300/00; H01M2300/0017; H01M2300/0065; H01M2300/0068; H01M2300/0071; H01M2300/0074; H01M8/0215; H01M8/0217; H01M8/0219; 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: 15
Claim 1
Independent Claim
151 words
A method of forming a combustible polymer film containing a thin layer of doped LaCrO₃ particles, characterized by the steps: (1) providing LaCrO₃ particles doped with an element selected from the group consisting of Ca, Sr, Co, Ba, Mg, and mixtures thereof; (2) uniformly dispersing the particles in a solvent to provide a homogeneous dispersion; (3) wet screening the dispersion to provide particles in the range of from 30 micrometers to 80 micrometers; (4) admixing a fugitive polymer with the particles in an amount to provide homogeneous dispersion with a volume ratio of polymer plus particles:solvent of between 50:50 and 30:70 and a volume ratio of polymer:particles between 65:35 and 50:50; (5) casting the dispersion onto a substrate, to provide a film having a wet thickness of from 80 micrometers to 150 micrometers; (6) drying the film; and (7) stripping the film from the substrate, to provide a particle-fugitive polymer film.
Claim 2
Dependent Claim
25 words
The method of claim 1, characterized in that the fugitive polymer is in all cases a thermoplastic polymer which will vaporize at less than 1,100°C.
Claim 3
Dependent Claim
25 words
The method of claim 1, characterized in that the fugitive polymer is selected from the group consisting of acrylic polymers, polyvinyl chloride polymers, and polystyrenepolymers.
Claim 4
Dependent Claim
57 words
The method of claim 1, characterized in that the solvent in step (2) contains an effective amount of a dispersing aid, where, between steps (3) and (4), the particles are rinsed with solvent and dried, and where the particles screened in step (3) are within a narrow size range within the 30 micrometer to 80 micrometer range.
Claim 5
Dependent Claim
32 words
The method of claim 1, characterized in that the stripped film is flexible and has a thickness of from 30 micrometers to 80 micrometers, and the particles are essentially in a monolayer.
Claim 6
Dependent Claim
28 words
The method of claim 1, characterized in that the particles are LaCrO₃ doped with dopants selected from the group consisting of Co plus Sr, and Co plus Ba.
Claim 7
Dependent Claim
40 words
The method of claim 1, characterized in that the particles are selected from the group having the approximate chemical formulas of La 0.89 Sr 0.1 Co 0.1 Cr 0.9 O₃ and La 0.94 Ba 0.05 Co 0.1 Cr 0.9 O₃.
Claim 8
Dependent Claim
81 words
The method of claim 1, characterized in that the combustible polymer film is applied on a porous portion of a first surface of an electrode structure which is preheated to from 30°C to 80°C above the glass transition temperature of the fugitive polymer, while applying a vacuum on the opposite surface of the electrode structure, and then electrochemical vapor depositing a dense skeletal structure comprising LaCrO₃, between and around the doped LaCrO₃ particles, where, during initial heating the fugitive binder volatilizes.
Claim 9
Dependent Claim
50 words
The method of claim 8, characterized in that the electrode structure is a porous, tubular cathode of doped LaMnO₃, and where a protective fugitive polymer film is applied on top of the particle-fugitive polymer film before electrochemical vapor deposition, which top fugitive polymer film is also volatilized during initial heating.
Claim 10
Dependent Claim
37 words
The method of claim 8, characterized in that solid oxide electrolyte is applied over the remaining portion of the air electrode surface and a cermet fuel electrode is applied over the electrolyte, to provide an electrochemical cell.
Claim 11
Independent Claim
155 words
A method of bonding a dense, high temperature electronically conductive layer on an electrode structure characterized by the steps: (A) applying a thin particle-fugitive polymer film, having essentially a monolayer of LaCrO₃ particles doped with an element selected from the group consisting of Ca, Sr, Co, Ba, Mg, and mixtures thereof, on a porous portion of a first surface of an electrode structure which is preheated to from 30°C to 80°C above the glass transition temperature of the fugitive polymer, while applying a vacuum on the opposite surface of the electrode structure, and then (B) electrochemical vapor depositing a dense skeletal structure comprising LaCrO₃, between and around the doped LaCrO₃ particles, where, during initial heating to vapor deposit, the fugitive polymer volatilizes, and where the particles get incorporated into the lanthanum chromium oxide structure as it grows thicker with time, to provide a dense, high temperature electronically conductive interconnection layer on the porous electrode structure.
Claim 12
Dependent Claim
50 words
The method of claim 11, characterized in that the electrode structure is a porous, tubular cathode of doped LaMnO₃, and where a protective fugitive polymer film is applied on top of the particle-fugitive polymer film before electrochemical vapor deposition, which top fugitive polymer film is also volatilized during initial heating.
Claim 13
Dependent Claim
69 words
The method of claim 11, characterized in that the fugitive polymer is in all cases a thermoplastic polymer which will vaporize at less than 1,100°C, the particle-fugitive binder film has a thickness of from 30 micrometers to 80 micrometers with the particles essentially in a monolayer, and the particles are LaCrO₃ doped with an element selected from the group consisting of Ca, Sr, Co, Ba, Mg, and mixtures thereof.
Claim 14
Dependent Claim
37 words
The method of claim 11, characterized in that solid oxide electrolyte is applied over the remaining portion of the air electrode surface and a cermet fuel electrode is applied over the electrolyte, to provide an electrochemical cell.
Claim 15
Dependent Claim
47 words
The method of claim 11, characterized in that by appropriately choosing the dopant concentration in the particles and the amount of particles to be incorporated in the interconnection, the thermal expansion of the final interconnection can be tailored to match all other components of the electrochemical cell.
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