Sodium sulfur battery or cell with improved ampere-hour capacity
An improved secondary battery or cell comprises the following components: (A) One or more anodic reaction zones contain a molten alkali metal reactant-anode in electrical contact with an external circuit. (B) One or more cathodic reaction zones contain (1) a cathodic reactant which, when the battery or cell is at least partially discharged, is selected from the group consisting of a single-phase composition comprising molten polysulfide salts of the anodic reactant and a two-phase composition comprising molten sulfur and molten sulfur saturated polysulfide salts of the anodic reactant and (2) an electrode of porous conductive material which is at least partially filled with the cathodic reactant. (C) A cation-permeable barrier to mass liquid transfer is interposed between and in contact with the anodic and cathodic reaction zones, the porous conductive material being in electrical contact with both the cation-permeable barrier and an external circuit. The improvement comprises the following: employing a porous conductive material which will wick both sulfur and alkali metal polysulfides and which, in different regions of the cathodic reaction zone, exhibits different degrees of wettability by the alkali metal polysulfides, the material in a region adjacent to the cation-permeable barrier being more readily wetted by the polysulfides than is the material in a region further removed from the barrier such that sulfur will boil near the barrier and condense away from it;disposing the porous conductive material within the cathodic reaction zone such that it forms and encloses one or more channels which extend from the region adjacent the cation-permeable barrier outward into the region of the cathodic reaction zone which is further removed from the barrier; and maintaining the amount of molten cathodic reactant within the cathodic reaction zone such that the channels remain free of the molten reactant and are thus adapted to transport sulfur vapor. 3 figures.
- Assignee:
- Ford Motor Co.
- Patent Number(s):
- US 3966492
- OSTI ID:
- 7180693
- Resource Relation:
- Patent File Date: Filed date 20 Aug 1975
- Country of Publication:
- United States
- Language:
- English
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