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US4407912A Expired / Lapsed US ⏱️ 0.0 years remaining

Electrochemical cell utilizing molten alkali metal electrode-reactant

Assignee: Ceramatec Inc
•
Filing: 1981-10-13
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Granted: 1983-10-04
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Expires: 2001-10-13
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Abstract

Abstract An improved electrochemical cell comprising an additive-modified molten alkali metal electrode-reactant and/or electrolyte is disclosed. Various electrochemical cells employing a molten alkali metal, e.g., sodium, electrode in contact with a cationically conductive ceramic membrane experience a lower resistance and a lower temperature coefficient of resistance whenever small amounts of selenium are present at the interface of the electrolyte and the molten alkali metal. Further, cells having small amounts of selenium present at the electrolyte-molten metal interface exhibit less degradation of the electrolyte under long term cycling conditions.

Inventors

  • 👤 Anil V. Virkar
  • 👤 Gerald R. Miller

Bibliographic Details

Application Number —
Jurisdiction US
Data Source google_patents
Last Synchronized 2026-10-27 09:59
CPC Classifications
H; H01; H01M; H01M10/00; H01M10/36; H01M10/39; H01M10/3909; H01M4/00; H01M4/02; H01M4/36; H01M4/38; Y; Y02; Y02E; Y02E60/00; Y02E60/10

Claims Analysis

Total Claims: 16
Claim 1
Independent Claim 92 words
An improved electrochemical cell comprising; a first electrode of a molten alkali metal; a solid, impervious electrolyte containing a mobile alkali metal ion of the same alkali metal as is present in said first electrode, said electrolyte separating said first electrode from a second electrode; a second electrode of a molten material receptive to the mobile alkali metal ion in said electrolyte; and at least sufficient selenium present at the interface between said molten alkali metal of said first electrode and said electrolyte to effect a lowering of the internal cell resistance.
Claim 2
Dependent Claim 92 words
An improved electrochemical cell comprising; a first electrode of a molten alkali metal; a solid, impervious electrolyte containing a mobile alkali metal ion of the same alkali metal as is present in said first electrode, said electrolyte separating said first electrode from a second electrode; a second electrode of a molten material receptive to the mobile alkali metal ion in said electrolyte; and at least sufficient selenium present at the interface between said molten alkali metal of said first electrode and said electrolyte to effect a lowering of the internal cell resistance.
Claim 3
Dependent Claim 21 words
The electrochemical cell of claim 1 wherein said second electrode comprises the same alkali metal as is in said first electrode.
Claim 4
Dependent Claim 27 words
The electrochemical cell of claim 1 wherein said second electrode comprises a material reactive with and substantially displaced from the alkali metal present as the first electrode.
Claim 5
Dependent Claim 12 words
The electrochemical cell of claim 1 wherein said first electrode is sodium.
Claim 6
Dependent Claim 12 words
The electrochemical cell of claim 1 wherein said second electrode is sulfur.
Claim 7
Dependent Claim 12 words
The electrochemical cell of claim 4 wherein the second electrode is sodium.
Claim 8
Dependent Claim 25 words
The electrochemical cell of claim 1 wherein said selenium is present at said interface as an additive to said alkali metal of said first electrode.
Claim 9
Dependent Claim 24 words
The electrochemical cell of claim 7 wherein said selenium is present in an amount of at least 0.01% by weight in said alkali metal.
Claim 10
Dependent Claim 24 words
The electrochemical cell of claim 7 wherein said selenium is present in an amount of at least 0.5% by weight in said alkali metal.
Claim 11
Dependent Claim 25 words
The electrochemical cell of claim 1 wherein said selenium is present at said interface as a material on or near the surface of said electrolyte.
Claim 12
Dependent Claim 11 words
The electrochemical cell of claim 1 wherein said electrolyte is beta"-alumina.
Claim 13
Independent Claim 91 words
A method of lowering the internal resistance of an electrochemical cell having a first electrode of a molten alkali metal; a solid, impervious electrolyte containing a mobile alkali metal ion of the same alkali metal as is present in said first electrode, said electrolyte separating said first electrode from a second electrode; and a second electrode of a molten material receptive to the mobile alkali metal ion in said electrolyte; comprising, introducing sufficient selenium to the first electrode side of said cell to reduce significantly the internal resistance of said cell.
Claim 14
Independent Claim 91 words
A method of lowering the internal resistance of an electrochemical cell having a first electrode of a molten alkali metal; a solid, impervious electrolyte containing a mobile alkali metal ion of the same alkali metal as is present in said first electrode, said electrolyte separating said first electrode from a second electrode; and a second electrode of a molten material receptive to the mobile alkali metal ion in said electrolyte; comprising, introducing sufficient selenium to the first electrode side of said cell to reduce significantly the internal resistance of said cell.
Claim 15
Dependent Claim 27 words
The method of claim 12 wherein a very small amount of selenium is introduced into the first electrode chamber prior to the addition of the alkali metal.
Claim 16
Dependent Claim 26 words
The method of claim 13 wherein said cell containing selenium is heated at a sufficient temperature for a sufficient period of time to dehydrate said cell.

References Cited (Backward Citations)

US3404036A Cited
US3404035A Cited
US3458356A Cited

USPTO Annuity & Maintenance Windows

Annuity Stage Window Opens Payment Deadline Surcharge Period Until Estimated Fee Status
3.5 Years (Year 4) 1986-10-03 1987-04-04 1987-10-04 $2000.00 Window Closed / Lapsed
7.5 Years (Year 8) 1990-10-03 1991-04-04 1991-10-04 $3760.00 Window Closed / Lapsed
11.5 Years (Year 12) 1994-10-03 1995-04-04 1995-10-04 $7700.00 Window Closed / Lapsed

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