Cell for a metal-air battery

• US 5,366,822 A
• Filed: 03/15/1994
• Issued: 11/22/1994
• Est. Priority Date: 03/15/1994
• Status: Expired due to Fees

• Current Assignee: Electric Fuel Ltd.
• Original Assignee: Electric Fuel Ltd.
• Inventors: Korall, Menachem, Harats, Yehuda
• Primary Examiner(s): Skapars, Anthony
• Application Number:
  US08/213,674
• Time in Patent Office: 252 Days
• Field of Search: 429/27, 429/72, 429/82, 429/96, 429/99, 429/100, 429/157, 429/159, 429/162, 429/163
• US Class Current: 429/407
• CPC Class Codes: H01M 12/065 with plate-like electrodes or stacks of plate-like electrodes
• CPC Class Codes: H01M 50/50 Current conducting connections for cells or batteries
• CPC Class Codes: Y02E 60/10 Energy storage using batteries

Abstract

A modular cell for a multi-cell metal-air battery system, comprises a relatively flat cell housing having two major surfaces and accommodating a pair of oppositely disposed, spaced-apart, air-permeable, liquid-impermeable cathodes in the form of air electrodes defining between themselves a space open towards the upper edges of the cell housing and closed at the lateral edges and the bottom of the cell housing, the space being configured to accommodate an anode of said battery, substantial portions of the major surfaces of the housing being removed, thus exposing major portions of the air electrodes. The two major surfaces of the housing are partly recessed in such a way as to form, in conjunction with a similarly recessed outer surface of a major wall of an adjacent cell housing, an air space with air access and exits, and the exposed portions of the air electrodes are supported and reinforced by ribbing constituted at least by a plurality of slender rails, which rails define ducts for guiding a flow of air across the portions of the air electrodes from the air access toward the exits.

Claims

1. A modular cell for a multi-cell metal-air battery system, comprising a relatively flat cell housing having two major surfaces and accommodating a pair of oppositely disposed, spaced-apart, air-permeable, liquid-impermeable cathodes in the form of air electrodes defining between themselves a space open towards the upper edges of said cell housing and closed at the lateral edges and the bottom of said cell housing, said space being configured to accommodate an anode of said battery, substantial portions of the major surfaces of said housing being removed, thus exposing major portions of said air electrodes, characterized in that said two major surfaces are partly recessed in such a way as to form, in conjunction with a similarly recessed outer surface of a major wall of an adjacent cell housing, an air space with air access and exits, and that the exposed portions of said air electrodes are supported and reinforced by ribbing constituted at least by a plurality of slender rails, which rails define ducts for guiding a flow of air across said portions of said air electrodes from said air access toward said exits.

2. The cell as claimed in claim 1, comprising a relatively flat cell housing constituted of two housing halves, said housing having two major surfaces and accommodating a pair of oppositely disposed, spaced-apart, air-permeable, liquid-impermeable cathodes in the form of air electrodes defining between themselves a space open towards the upper edges of said cell housing and closed at the lateral edges and the bottom of said cell housing, said space being configured to accommodate an anode of said battery, substantial portions of the major surfaces of said housing being removed, thus exposing major portions of said air electrodes, characterized in that said two major surfaces are partly recessed in such a way as to form, in conjunction with a similarly recessed outer surface of a major wall of an adjacent cell housing, an air space with air access at the lower edge of said cell housing and exits at least at the upper regions of the lateral edges thereof, and that the exposed portions of said air electrodes are supported and reinforced by ribbing constituted at least by a plurality of generally upwardly-extending rails, which rails define ducts for air entering said air space from below and exiting it at said upper regions.

3. The cell as claimed in claim 2, further comprising registering means provided along mating edges of said housing halves to facilitate the accurate joining thereof.

4. The cell as claimed in claim 1, wherein said air exits are in the form of narrowed slots.

5. The cell as claimed in claim 1, wherein said housing is a split housing.

6. The cell as claimed in claim 1, wherein said ducts are defined by said rails in conjunction with similar rails of adjacent cell housings.

7. The cell as claimed in claim 1, wherein said rails extend in a substantially vertical direction.

8. The cell as claimed in claim 7, further comprising a plurality of webs extending in a substantially horizontal direction and interlinking and reinforcing said rails, and further supporting and reinforcing said air electrodes.

9. The cell as claimed in claim 8, wherein, closer to the bottom of said cell, spacing between said webs is reduced to provide more support where hydrostatic pressure is greater.

10. The cell as claimed in claim 1, further comprising first and second terminal means connected to said anode and said cathodes respectively, to facilitate a breakable series connection between the anode of one cell and the cathodes of a directly adjacent cell.

11. The cell as claimed in claim 10, wherein said second terminal means are provided with shaped springs to ensure adequate electrical contact between said first and said second terminals.

12. The cell as claimed in claim 1, further comprising registering means provided along the major outer surfaces of said housing, facilitating a well-defined and mechanically strengthened juxtaposition, major surface to major surface, of a plurality of said cell housings.

13. The cell as claimed in claim 1, wherein said air electrodes consist of an electrochemically-active material compressed upon a conductive metal screen.

14. The cell as claimed in claim 1, further comprising a partial, three-sided frame extending along the inner vertical edges and the inner bottom edge of said cell housing and having an H-shaped cross-section, one of the grooves forming said H-shape accommodating a rod-like current collector connecting at least one of said metal screens to said second terminals, the second one of said grooves forming said H-shape serving as guide and positioning groove for said anode.

15. The cell as claimed in claim 14, wherein the outer surfaces of said partial frame serve as spacers to said air electrodes, to which outer surfaces the marginal portions of the inner surfaces of said air electrodes are fixedly joined.

16. The cell as claimed in claim 14, wherein said three-sided frame has a U-shaped cross-section, the inside surfaces of which serve as guide and positioning surfaces for said anode.

17. The cell as claimed in claim 16, further comprising a current collector in the form of an elongated metal bar connecting at least one of said metal screens to said second terminals, said collector being located in a space formed between a lateral inside wall of said cell and a lateral member of said three-sided frame.

18. The cell as claimed in claim 1, wherein the upper edges of each cell are designed with half of each edge protruding in the form of a lip that, in any cell of a string of said modular cells, overlaps the non-protruding edge half of any directly adjacent cell, with the lip of said adjacent cell overlapping the non-protruding edge of the first cell.

19. The cell as claimed in claim 1, further comprising a plurality of projections disposed on portions of said recessed surfaces forming said air space for the purpose of preventing deformation of said recessed surfaces liable to impede air passage through said space.