US4087905A
Expired / Lapsed
US
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Method of preparing a powdered, electrically insulative separator for use in an electrochemical cell
Assignee: United States Department of Energy
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Filing: 1977-03-30
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Granted: 1978-05-09
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Expires: 1997-03-30
Abstract
Abstract A secondary electrochemical cell includes electrodes separated by a layer of electrically insulative powder. The powder includes refractory materials selected from the oxides and nitrides of metals and metaloids. The powdered refractory material, blended with electrolyte particles, is compacted as layers onto an electrode to form an integral electrode structure and assembled into the cell. The assembled cell is heated to its operating temperature leaving porous layers of electrically insulative, refractory particles, containing molten electrolyte between the electrodes.
Inventors
- 👤 Tom O. Cooper
- 👤 William E. Miller
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-26 22:49
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/36; H01M10/39; H01M10/399; Y; Y02; Y02E; Y02E60/00; Y02E60/10; Y02P; Y02P70/00; Y02P70/50; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49002; Y10T29/49108
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
135 words
A method of preparing an electrode structure for use in a secondary, electrochemical cell comprising disposing a layer of a particulate mixture of powdered, refractory, electrically insulative material blended with a binder of powdered, electrolytic salt selected from alkali metal halides, alkaline earth metal halides, and mixtures thereof within a die suitable for pressing powders; centrally placing an electrode compact onto said particulate mixture layer within said die to define an annular volume around said electrode compact within the die walls; filling said annular volume and covering the upper surface of said electrode compact with additional amounts of said particulate mixture including powdered, refractory, electrically insulative material; and pressing said layers and electrode compact and particulate mixture to form an integral structure having a compacted layer including refractory, electrically insulative particles at all outer surfaces.
Claim 2
Independent Claim
135 words
A method of preparing an electrode structure for use in a secondary, electrochemical cell comprising disposing a layer of a particulate mixture of powdered, refractory, electrically insulative material blended with a binder of powdered, electrolytic salt selected from alkali metal halides, alkaline earth metal halides, and mixtures thereof within a die suitable for pressing powders; centrally placing an electrode compact onto said particulate mixture layer within said die to define an annular volume around said electrode compact within the die walls; filling said annular volume and covering the upper surface of said electrode compact with additional amounts of said particulate mixture including powdered, refractory, electrically insulative material; and pressing said layers and electrode compact and particulate mixture to form an integral structure having a compacted layer including refractory, electrically insulative particles at all outer surfaces.
Claim 3
Dependent Claim
72 words
The method of claim 1 wherein said integral electrode structure is assembled within an electrochemical cell with electrodes of opposite polarity facing opposite surfaces of said electrode structure enclosed within said layers of electrolytic salt and refractory, electrically insulative material; and said electrochemical cell is heated to a temperature at which said electrolytic salt becomes molten leaving a porous separator of discrete particles of refractory, electrically insulative material enclosing said electrode compact.
Claim 4
Dependent Claim
28 words
The method of claim 1 wherein said refractory, electrically insulative material is boron nitride, magnesium oxide, calcium oxide, yttria, lithium aluminate, silicon nitride, aluminum nitride or mixtures thereof.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein said layers and electrode compact are pressed at about 70-80 MPa.
Claim 6
Dependent Claim
17 words
The method of claim 1 wherein said particulate mixture includes about 30 to 50 volume percent electrolyte.
Claim 7
Dependent Claim
50 words
The method of claim 1 wherein screens having apertures smaller than the particle size in a major fraction of the refractory material powder are disposed above and below the upper and lower layers of refractory, electrically insulative material prior to pressing to incorporate said screens into said integral electrode structure.
Claim 8
Dependent Claim
29 words
The method of claim 6 wherein said major fraction of refractory particles are of about 150-250 micrometers particle size and said screens are about 325 U.S. sieve series mesh.
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) | 1981-05-08 | 1981-11-07 | 1982-05-09 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1985-05-08 | 1985-11-07 | 1986-05-09 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1989-05-08 | 1989-11-07 | 1990-05-09 | $7700.00 | Window Closed / Lapsed |