US5399443A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fuel cells
Assignee: Electric Power Research Institute
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Filing: 1994-04-22
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Granted: 1995-03-21
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Expires: 2014-04-22
Abstract
Abstract Electrolyte matrix structures for molten carbonate fuel cells which: have a fine, uniform, and controlled porosity; are stable under operating conditions; and readily meet acceptable performance levels. These structures or matrices are easily manufactured by a simple and scalable technique from a slip containing particulate LiAlO2 dispersed in an organic vehicle and an acrylic-based binder. The solvent is evaporated, leaving a flat, flexible, green structure. The green-structure is heated in a non-oxidizing atmosphere to thermally decompose and thereby remove the binder. This leaves a porous structure which is impregnated with molten carbonate by capillary action.
Inventors
- 👤 Estela T. Ong
- 👤 Elias H. Camara
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 17:53
CPC Classifications
H; H01; H01M; H01M8/00; H01M8/02; H01M8/0289; H01M8/0295; H01M8/14; H01M2008/147; H01M2300/00; H01M2300/0017; H01M2300/0048; H01M2300/0051; Y; Y02; Y02E; Y02E60/00; Y02E60/30; Y02E60/50; Y02P; Y02P70/00; Y02P70/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
121 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte; said LiAlO 2 particles being produced by heat treating an equimolar mixture of Li 2 CO 3 and Al 2 O 3 .
Claim 2
Independent Claim
121 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte; said LiAlO 2 particles being produced by heat treating an equimolar mixture of Li 2 CO 3 and Al 2 O 3 .
Claim 3
Independent Claim
146 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing uncoated particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte; said LiAlO 2 particles being produced by spray drying an aqueous slurry containing LiOH and Al 2 O 3 to produce β-LiAlO 2 particles and then heat treating those particles to transform the particles to the gamma phase and to reduce the surface area of the particles.
Claim 4
Independent Claim
146 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing uncoated particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte; said LiAlO 2 particles being produced by spray drying an aqueous slurry containing LiOH and Al 2 O 3 to produce β-LiAlO 2 particles and then heat treating those particles to transform the particles to the gamma phase and to reduce the surface area of the particles.
Claim 5
Independent Claim
130 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: preparing a castable, non-aqueous slip comprising particles of LiAlO 2 , a binder, and a solvent; subjecting said slip to vibratory milling to break up any agglomerates of LiAlO 2 particles that may be present and to uniformly disperse the particles in the solvent; so casting said slip as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte.
Claim 6
Independent Claim
130 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: preparing a castable, non-aqueous slip comprising particles of LiAlO 2 , a binder, and a solvent; subjecting said slip to vibratory milling to break up any agglomerates of LiAlO 2 particles that may be present and to uniformly disperse the particles in the solvent; so casting said slip as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte.
Claim 7
Independent Claim
142 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte by placing said matrix in face-to-face relationship with a carbonate tape and so heating the resulting assemblage to a temperature above the melting point of the carbonate that said carbonate will be melted and wicked into the pores of the matrix by capillary action.
Claim 8
Independent Claim
142 words
A method for preparing an electrolyte structure for a molten carbonate fuel cell, said method comprising the steps of: so casting a non-aqueous slip containing particles of LiAlO 2 , a binder, and a solvent as to form a flexible cast tape of selected thickness; removing the solvent from the cast tape to produce a green tape having LiAlO 2 particles held together by the binder; subsequently so treating the green tape as to remove the binder therefrom and create a porous matrix consisting essentially of LiAlO 2 ; and impregnating the porous matrix with a carbonate electrolyte by placing said matrix in face-to-face relationship with a carbonate tape and so heating the resulting assemblage to a temperature above the melting point of the carbonate that said carbonate will be melted and wicked into the pores of the matrix by capillary action.
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) | 1998-03-20 | 1998-09-19 | 1999-03-21 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2002-03-20 | 2002-09-19 | 2003-03-21 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2006-03-20 | 2006-09-19 | 2007-03-21 | $7700.00 | Window Closed / Lapsed |