Patent US4820596A successfully refreshed from Google Patents.
US4820596A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Alkali metal-refractory metal biphase electrode for AMTEC
Assignee: California Institute of Technology
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Filing: 1987-08-06
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Granted: 1989-04-11
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Expires: 2007-08-06
Abstract
Abstract An electrode having increased output with slower degradation is formed of a film applied to a beta-alumina solid electrolyte (BASE). The film comprises a refractory first metal M1 such as a platinum group metal, suitably platinum or rhodium, capable of forming a liquid or a strong surface adsorption phase with sodium at the operating temperature of an alkali metal thermoelectric converter (AMTEC) and a second refractory metal insoluble in sodium or the NaM1 liquid phase such as a Group IVB, VB or VIB metal, suitably tungsten, molybdenum, tantalum or niobium. The liquid phase or surface film provides fast transport through the electrode while the insoluble refractory metal provides a structural matrix for the electrode during operation. A trilayer structure that is stable and not subject to deadhesion comprises a first, thin layer of tungsten, an intermediate co-deposited layer of tungsten-platinum and a thin surface layer of platinum.
Inventors
- 👤 Roger M. Williams
- 👤 Clyde P. Bankston
- 👤 Terry Cole
- 👤 Satish K. Khanna
- 👤 Barbara Jeffries-Nakamura
- 👤 Bob L. Wheeler
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 01:00
CPC Classifications
H; H01; H01G; H01G9/00; H01G9/21; H01M; H01M10/00; H01M10/36; H01M10/39; H01M10/3909; Y; Y02; Y02E; Y02E60/00; Y02E60/10
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
124 words
An electrode comprising in combination: a body of solid, microcrystalline, ceramic electrolyte capable of transporting sodium ions from a first surface to a second surface selected from beta-alumina or beta" alumina; an electrode film of porous metal applied to one of said surface, said film being non-volatile at a temperature up to 1300 K and being formed of the composition M 1 M 2 where M 1 and M 2 are refractory metals, M 1 is a platinum group metal capable of forming a liquid phase with sodium and/or exhibiting a strong surface adsorption of sodium atoms, and M 2 a metal selected from Groups IVB, or VB or VIB of the Periodic Table which is insoluble in sodium and in said liquid phase.
Claim 2
Dependent Claim
124 words
An electrode comprising in combination: a body of solid, microcrystalline, ceramic electrolyte capable of transporting sodium ions from a first surface to a second surface selected from beta-alumina or beta" alumina; an electrode film of porous metal applied to one of said surface, said film being non-volatile at a temperature up to 1300 K and being formed of the composition M 1 M 2 where M 1 and M 2 are refractory metals, M 1 is a platinum group metal capable of forming a liquid phase with sodium and/or exhibiting a strong surface adsorption of sodium atoms, and M 2 a metal selected from Groups IVB, or VB or VIB of the Periodic Table which is insoluble in sodium and in said liquid phase.
Claim 3
Dependent Claim
25 words
An electrode according to claim 1 in which the film is formed by applying separate layers of M 1 and M 2 to said surface.
Claim 4
Dependent Claim
22 words
An electrode according to claim 1 in which the film is formed by codepositing M 1 and M 2 on said surface.
Claim 5
Dependent Claim
15 words
An electrode according to claim 2 in which the electrode is formed of three layers.
Claim 6
Dependent Claim
41 words
An electrode according to claim 4 in which the first layer is a thin layer of M 2 metal, the intermediate layer is a mixture of M 1 and M 2 metals and the top layer comprises an M 1 metal.
Claim 7
Dependent Claim
26 words
An electrode according to claim 1 in which the M 1 M 2 film contains from 1 atomic percent to 80 atomic percent M 1 .
Claim 8
Dependent Claim
18 words
An electrode according to claim 6 in which the film has a thickness from 0.1 to 20 micrometers.
Claim 9
Dependent Claim
16 words
An electrode according to claim 1 in which M 1 is selected from platinum or rhodium.
Claim 10
Dependent Claim
18 words
An electrode according to claim 8 in which M 2 is selected from tungsten, molybdenum, niobium or tantalum.
Claim 11
Independent Claim
149 words
A method of converting thermal energy to electrical energy comprising the steps of: placing liquid sodium at a first temperature in contact with a first surface of a solid, microcrystalline, cermic electrolyte selected from beta alumina or beta" alumina; transporting sodium in ionic form through the solid electrolyte to a second surface at lower pressure and lower temperature, said second surface containing a porous metal film that is non-volatile at a temperature up to 1300 K and comprising the composition M 1 M 2 where M 1 is a refractory, platinum group metal capable of forming a liquid phase with sodium and/or exhibiting a strong surface adsorption of sodium atoms, and M 2 is a refractory metal insoluble in sodium and in said liquid phase selected from Groups IVB, VB or VIB of the Periodic Table; and developing an electrical potential between said first surface and said liquid sodium.
Claim 12
Independent Claim
149 words
A method of converting thermal energy to electrical energy comprising the steps of: placing liquid sodium at a first temperature in contact with a first surface of a solid, microcrystalline, cermic electrolyte selected from beta alumina or beta" alumina; transporting sodium in ionic form through the solid electrolyte to a second surface at lower pressure and lower temperature, said second surface containing a porous metal film that is non-volatile at a temperature up to 1300 K and comprising the composition M 1 M 2 where M 1 is a refractory, platinum group metal capable of forming a liquid phase with sodium and/or exhibiting a strong surface adsorption of sodium atoms, and M 2 is a refractory metal insoluble in sodium and in said liquid phase selected from Groups IVB, VB or VIB of the Periodic Table; and developing an electrical potential between said first surface and said liquid sodium.
Claim 13
Dependent Claim
30 words
A method according to claim 10 in which the porous film contains a base layer of M 2 metal and a further codeposited layer of M 1 M 2 metal.
Claim 14
Dependent Claim
19 words
A method according to claim 11 in which the film further contains a top layer of M 1 metal.
Claim 15
Dependent Claim
38 words
A method acording to claim 10 in which the sodium leaves the second surface as a vapor and further including the steps of condensing the vapor to liquid sodium and returning the liquid sodium to said first surface.
Claim 16
Dependent Claim
38 words
A method according to claim 10 further including the steps of heating the sodium to said first temperature by transferring heat from a heat source and condensing said vapor by transferring heat from the vapor to a condenser.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
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| 3.5 Years (Year 4) | 1992-04-10 | 1992-10-10 | 1993-04-11 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-04-10 | 1996-10-10 | 1997-04-11 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-04-10 | 2000-10-10 | 2001-04-11 | $7700.00 | Window Closed / Lapsed |