Active metal fuel cells

• US 7,781,108 B2
• Filed: 12/12/2008
• Issued: 08/24/2010
• Est. Priority Date: 11/10/2003
• Status: Expired due to Fees

• Current Assignee: PolyPlus Battery Company
• Original Assignee: PolyPlus Battery Company
• Inventors: Visco, Steven J., Katz, Bruce D., De Jonghe, Lutgard C., Nimon, Yevgeniy S.
• Primary Examiner(s): Cantelmo; Gregg
• Application Number:
  US12/334,116
• Publication Number:
  US 20090286114A1
• Time in Patent Office: 620 Days
• Field of Search: 429/27, 429/126, 429/137, 429/144
• US Class Current: 429/402
• CPC Class Codes: H01M 12/04 composed of a half-cell of the fuel-cell type and of a half-cell of the primary-cell type
• CPC Class Codes: H01M 12/08 composed of a half-cell of a fuel-cell type and a half-cell of the secondary-cell type
• CPC Class Codes: H01M 16/003 of fuel cells with other electrochemical devices, e.g. capacitors, electrolysers
• CPC Class Codes: H01M 4/40 Alloys based on alkali metals
• CPC Class Codes: H01M 50/431 Inorganic material
• CPC Class Codes: H01M 50/434 Ceramics
• CPC Class Codes: H01M 50/437 Glass
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 90/40 Fuel cell technologies in production processes

Abstract

Active metal fuel cells are provided. An active metal fuel cell has a renewable active metal (e.g., lithium) anode and a cathode structure that includes an electronically conductive component (e.g., a porous metal or alloy), an ionically conductive component (e.g., an electrolyte), and a fluid oxidant (e.g., air, water or a peroxide or other aqueous solution). The pairing of an active metal anode with a cathode oxidant in a fuel cell is enabled by an ionically conductive protective membrane on the surface of the anode facing the cathode.

Claims

1. A lithium fuel cell, comprising:

an anode comprising solid lithium metal as fuel;

a cathode structure comprising a static electronically conductive component, an ionically conductive component, and a fluid oxidant; and

a lithium ion conductive protective membrane adjacent to the lithium anode, the membrane interposed between the anode and the cathode structure, the membrane isolating the anode from components of the cathode structure;

wherein the ionically conductive component comprises a liquid electrolyte and the fluid oxidant comprises oxygen continuously supplied from the air; and

further comprising lithium dissolved in a solvent on the anode side of the membrane;

wherein the anode is configured such that lithium ions electrically migrate through the membrane to the cathode side during discharge of the fuel cell.

2. The cell of claim 1 wherein the anode is renewable and replaceable.

3. The cell of claim 2 wherein subsequent to cell discharge the renewable anode is supplementarily replaced with a fresh lithium anode.

4. The cell of claim 1 wherein the fluid oxidant further comprises a liquid oxidant.

5. The cell of claim 4 wherein the liquid oxidant comprises an aqueous solution.

6. The cell of claim 4 wherein the liquid oxidant is supplemented by flushing fresh liquid oxidant through the cathode structure.

7. The cell of claim 1 wherein the electrolyte comprises water.

8. The cell of claim 1 wherein the electrolyte comprises an aqueous solution.

9. The cell of claim 1 wherein the electrolyte is flushed through the cathode structure.

10. The cell of claim 9 wherein waste products generated during cell discharge are removed by flushing the electrolyte through the cathode structure.

11. A method of providing continuous electrical power, the method comprising:

i) providing a lithium fuel cell comprising;

an anode comprising solid lithium metal as fuel;

a cathode structure comprising a static electronically conductive component, an ionically conductive component, and a fluid oxidant; and

a lithium ion conductive protective membrane adjacent to the lithium anode, the membrane interposed between the anode and the cathode structure, the membrane isolating the anode from components of the cathode structure;

wherein the ionically conductive component is a liquid electrolyte and the fluid oxidant comprises oxygen continuously supplied from the air; and

further comprising lithium dissolved in a solvent on the anode side of the membrane, and wherein lithium ions electrically migrate through the membrane to the cathode side during discharge of the fuel cell;

ii) discharging the fuel cell; and

iii) supplementarily adding fresh solid lithium metal fuel for the anode.

12. The method of claim 11, further comprising repeating the discharging and adding until cell operation is no longer desired.

13. The method of claim 11 further comprising supplementarily replacing the electrolyte.

14. The method of claim 13 wherein the supplementarily replacing the electrolyte includes flushing the cathode structure with electrolyte.

15. The method of claim 11 wherein the fluid oxidant further comprises a liquid oxidant, and the method comprising:

i) providing the lithium fuel cell;

ii) discharging the fuel cell;

iii) supplementarily adding fresh solid lithium metal fuel for the anode;

iv) supplementarily replacing the liquid oxidant;

v) repeating the discharging, adding and replacing until cell operation is no longer desired.

16. The method of claim 15 wherein the supplementarily replacing the liquid oxidant includes flushing the cathode structure with liquid oxidant.

17. The method of claim 15 wherein the liquid oxidant comprises water.

18. The method of claim 15 wherein the liquid oxidant comprises an aqueous solution.

19. A method of removing waste product in the cathode structure of a lithium fuel cell, the method comprising:

i) providing a lithium fuel cell comprising;

an anode comprising solid lithium metal as fuel;

a cathode structure comprising a static electronically conductive component, an ionically conductive component, and a fluid oxidant; and

a lithium ion conductive protective membrane adjacent to the lithium anode, the membrane interposed between the anode and the cathode structure, the membrane isolating the anode from components of the cathode structure;

wherein the ionically conductive component is a liquid electrolyte and the fluid oxidant comprises oxygen continuously supplied from the air; and

further comprising lithium dissolved in a solvent on the anode side of the membrane, and wherein lithium ions electrically migrate through the membrane to the cathode side during discharge of the fuel cell;

ii) discharging the fuel cell, thereby creating waste products in the cathode structure; and

iii) flushing the cathode structure to remove the waste products from the cathode structure.

20. The method of claim 19 wherein the flushing comprises flushing electrolyte through the cathode structure.

21. The method of claim 19 wherein the fluid oxidant comprises a liquid oxidant.

22. The method of claim 21 wherein the flushing comprises flushing liquid oxidant through the cathode structure.

23. The method of claim 22 wherein the liquid oxidant comprises water.

24. The method of claim 23 wherein said liquid oxidant comprises an aqueous solution.

25. The method of claim 19 further comprising repeating the discharging and flushing until cell operation is no longer desired.