Patent US745079A successfully refreshed from Google Patents.
Patent US4883497A successfully refreshed from Google Patents.
US4883497A
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Formation of thin walled ceramic solid oxide fuel cells
Assignee: Arch Development Corp
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Filing: 1988-03-28
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Granted: 1989-11-28
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Expires: 2008-03-28
Abstract
Abstract To reduce thermal stress and improve bonding in a high temperature monolithic solid oxide fuel cell (SOFC), intermediate layers are provided between the SOFC's electrodes and electrolyte which are of different compositions. The intermediate layers are comprised of a blend of some of the materials used in the electrode and electrolyte compositions. Particle size is controlled to reduce problems involving differential shrinkage rates of the various layers when the entire structure is fired at a single temperature, while pore formers are provided in the electrolyte layers to be removed during firing for the formation of desired pores in the electrode layers. Each layer includes a binder in the form of a thermosetting acrylic which during initial processing is cured to provide a self-supporting structure with the ceramic components in the green state. A self-supporting corrugated structure is thus formed prior to firing, which the organic components of the binder and plasticizer removed during firing to provide a high strength, high temperature resistant ceramic structure of low weight and density.
Inventors
- 👤 Terry D. Claar
- 👤 Donald E. Busch
- 👤 John J. Picciolo
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 07:42
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/24; H01M8/241; H01M8/2425; H01M8/2435; H01M8/2404; 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: 23
Claim 1
Independent Claim
160 words
A method for forming an SOFC comprising the steps of: dispersing each of four ceramic powders into respective ones of a plurality of liquid media to form four slips of an anode, a cathode, an electrolyte and an interconnect; milling a binder and a plasticizer into each of said four slips; casting the four slips into thin layers or tapes; forming a plurality of said tapes into a stacked array including the step of depositing an intermediate bonding layer between adjacent tapes, wherein said intermediate layers are comprised of portions of each of the adjacent layers between which the intermediate layer is disposed; forming a plurality of corrugations in the stacked array of tapes, wherein said corrugated stacked array is self-supporting; and heating the stacked array of tapes at an elevated temperature so as to increase the density of electrolyte and interconnect tapes, form bonds between adjacent tapes, and rigidify and increase the strength of the stacked array of tapes.
Claim 2
Independent Claim
160 words
A method for forming an SOFC comprising the steps of: dispersing each of four ceramic powders into respective ones of a plurality of liquid media to form four slips of an anode, a cathode, an electrolyte and an interconnect; milling a binder and a plasticizer into each of said four slips; casting the four slips into thin layers or tapes; forming a plurality of said tapes into a stacked array including the step of depositing an intermediate bonding layer between adjacent tapes, wherein said intermediate layers are comprised of portions of each of the adjacent layers between which the intermediate layer is disposed; forming a plurality of corrugations in the stacked array of tapes, wherein said corrugated stacked array is self-supporting; and heating the stacked array of tapes at an elevated temperature so as to increase the density of electrolyte and interconnect tapes, form bonds between adjacent tapes, and rigidify and increase the strength of the stacked array of tapes.
Claim 3
Dependent Claim
32 words
The method of claim 1 wherein the anode is selected from one of the class consisting of the combination Ni and yttria stabilized zirconia, and the combination Co and yttria stabilized zirconia.
Claim 4
Dependent Claim
16 words
The method of claim 2 wherein the cathode is comprised of strontium doped LaMnO 3 .
Claim 5
Dependent Claim
14 words
The method of claim 3 wherein the electrolyte is comprised of yttria stabilized zirconia.
Claim 6
Dependent Claim
16 words
The method of claim 4 wherein the interconnect is comprised of magnesium doped LaCrO 3 .
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the binder is selected from one of the class consisting of acrylics, vinyls, cellulosics, and other film-forming binders.
Claim 8
Dependent Claim
22 words
The method of claim 1 wherein the plasticizer is selected from one of the class consisting of phthalates, polyethylene glycol, and glycerol.
Claim 9
Dependent Claim
27 words
The method of claim 1 wherein the liquid medium is selected from one of the class consisting of organic solvents, a mixture of organic solvents, and water.
Claim 10
Dependent Claim
24 words
The method of claim 8 wherein said organic solvent is selected from one of the class consisting of alcohols, ketones, hydrocarbons, and chlorinated hydrocarbons.
Claim 11
Dependent Claim
41 words
The method of claim 1 further comprising the step of milling each slip to a paint-like consistency to break up powder agglomerates, to disperse the ceramic particles uniformly within the slip, and to homogenize the binder, the plasticizer and the dispersant.
Claim 12
Dependent Claim
21 words
The method of claim 10 further comprising the step of de-airing each of the slips prior to deposit onto a substrate.
Claim 13
Dependent Claim
26 words
The method of claim 11 wherein the step of de-airing each of the slips includes the step of ultrasonic agitating the slip in a partial vacuum.
Claim 14
Dependent Claim
38 words
The method of claim 1 wherein the step of forming the layers of anode, electrolyte, cathode, and interconnect includes tape casting with a doctor blade each of the slips into which a respective ceramic powder has been dispersed.
Claim 15
Dependent Claim
27 words
The method of claim 1 wherein the step of forming the layers includes spraying onto a substrate the slips into which a ceramic powder has been dispersed.
Claim 16
Dependent Claim
21 words
The method of claim 1 further comprising the step of adding a pore forming material to the cathode and anode slips.
Claim 17
Dependent Claim
45 words
The method of claim 15 wherein the pore forming material is selected from one of the class consisting of graphite, carbon black, rice starch, cornstarch, or other cellulosic derivative, wherein the pore forming material is removed during subsequent heating of the stacked array of tapes.
Claim 18
Dependent Claim
72 words
The method of claim 1 wherein the anode is comprised of Ni and yttria stabilized zirconia and the electrolyte is comprised of yttria stabilized zirconia, and wherein the intermediate layer disposed between the anode and electrolyte is comprised of 30 vol % Ni/70 vol % yttria stabilized zirconia in contact with the yttria stabilized zirconia electrolyte and a 50 vol % Ni/50 vol % yttria stabilized zirconia in contact with the anode.
Claim 19
Dependent Claim
72 words
The method of claim 1 wherein the anode is comprised of Co and yttria stabilized zirconia and the electrolyte is comprised of yttria stabilized zirconia, and wherein the intermediate layer disposed between the anode and electrolyte is comprised of 30 vol % Co/70 vol % yttria stabilized zirconia in contact with the yttria stabilized zirconia electrolyte and a 50 vol % Co/50 vol % yttria stabilized zirconia in contact with the anode.
Claim 20
Dependent Claim
49 words
The method of claim 1 wherein the cathode is comprised of strontium doped LaMnO 3 and the electrolyte is comprised of yttria stabilized zirconia, and wherein the intermediate layer disposed between the cathode and electrolyte is comprised of 50 vol % LaMnO 3 /50 vol % yttria stabilized zirconia.
Claim 21
Dependent Claim
31 words
The method of claim 19 further comprising the step of spraying the intermediate layer on the interface between the cathode and electrolyte and on the interface between the anode and electrolyte.
Claim 22
Dependent Claim
49 words
The method of claim 1 wherein the anode is comprised of Ni and yttria stabilized zirconia and the interconnection is comprised of LaCrO 3 , and wherein the intermediate layer between the anode and interconnection is comprised of 50 vol % LaCrO 3 /50 vol % yttria stabilized zirconia.
Claim 23
Dependent Claim
49 words
The method of claim 1 wherein the anode is comprised of Co and yttria stabilized zirconia and the interconnection is comprised of LaCrO 3 , and wherein the intermediate layer between the anode and interconnection is comprised of 50 vol % LaCrO 3 /50 vol % yttria stabilized zirconia.
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) | 1992-11-27 | 1993-05-29 | 1993-11-28 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-11-27 | 1997-05-29 | 1997-11-28 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-11-27 | 2001-05-29 | 2001-11-28 | $7700.00 | Window Closed / Lapsed |