Electrochemical device and methods for energy conversion

• US 7,678,484 B2
• Filed: 07/25/2003
• Issued: 03/16/2010
• Est. Priority Date: 04/18/2000
• Status: Expired due to Fees

• Current Assignee: Sofc Holdings LLC
• Original Assignee: CellTech Power LLC
• Inventors: Bai, Wei, Tao, Tao T.
• Primary Examiner(s): Ryan; Patrick
• Assistant Examiner(s): Martin; Angela J.
• Application Number:
  US10/627,330
• Publication Number:
  US 20050089738A1
• Time in Patent Office: 2,426 Days
• Field of Search: 429/209, 429/49
• US Class Current: 429/444
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• 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 4/90 Selection of catalytic material
• CPC Class Codes: H01M 4/9025 Oxides specially used in fuel cell operating at high temperature, e.g. SOFC
• CPC Class Codes: H01M 4/921 Alloys or mixtures with metallic elements
• CPC Class Codes: H01M 8/1246 the electrolyte consisting of oxides
• CPC Class Codes: H01M 8/243 Grouping of unit cells of tubular or cylindrical configuration
• CPC Class Codes: H01M 8/2432 Grouping of unit cells of planar configuration
• CPC Class Codes: H01M 8/2484 characterised by external manifolds
• CPC Class Codes: Y02E 60/10 Energy storage using batteries
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y02P 70/50 Manufacturing or production processes characterised by the final manufactured product

Abstract

The present invention relates to an electrochemical device. The device features an anode constructed of materials such that the device can be chemically recharged. In addition, the device is capable of switching between operating as a fuel cell or as a battery. The switch can occur without cessation of electrical output. In certain aspects of the invention, the device is capable of operating at a temperature of less than 1000° C. Other aspects feature a liquid anode which allows higher output, dispersion of fuel and minimal stresses in an interface comprising the anode. Preferably the anode is a liquid at a temperature of less than 1000° C. The invention also relates to methods for energy conversion in which a continual electrical output can be produced in both the presence of fuel without anode consumption or the absence of fuel.

Claims

1. An electrochemical device comprising an anode that is chemically rechargeable, and a solid-state electrolyte, which remains solid at an operating temperature of the device, in ionic communication with the anode, wherein at least a portion of the anode is liquid at a temperature at which the anode is operated, and wherein the device is capable of producing electricity in the absence of fuel.

2. The device of claim 1, wherein the anode is operable at a temperature of less than about 1500°

C.

3. The device of claim 1, wherein the anode is operable at a temperature of less than about 1300°

C.

4. The device of claim 1, wherein the anode is operable at a temperature of less than about 1000°

C.

5. The device of claim 1, wherein the anode is operable at a temperature from about 300°

C. to about 1500°

C.

6. The device of claim 1, wherein the anode is operable at a temperature from about 300°

C. to about 1300°

C.

7. The device of claim 1, wherein the anode comprises liquid tin at a temperature at which the anode is operated.

8. The device of claim 1, further comprising a source of fuel exposable to the anode.

9. The device of claim 8, wherein the fuel, when exposed to the anode, is in contact with the anode.

10. The device of claim 1, wherein the device is self-repairing.

11. The device of claim 10, wherein the device further comprises a sealant precursor to seal a flaw in a solid state electrolyte when exposed to oxygen.

12. The device of claim 1, further comprising a solid-state cathode in ionic communication with the electrolyte, the solid-state cathode comprising a metal oxide, a mixed metal oxide, and/or a perovskite-type oxide.

13. The device of claim 1, wherein the solid-state electrolyte has a formula (ZrO₂)(HfO₂)_a(TiO₂)_b(Al₂O₃)_c(Y₂O₃)_d(M_xO_y)_e where a is from 0 to about 0.2, b is from 0 to about 0.5, c is from 0 to about 0.5, d is from 0 to about 0.5, x is greater than 0 and less than or equal to 2, y is greater than 0 and less than or equal to 3, e is from 0 to about 0.5, and M is selected from the group consisting of calcium, magnesium, manganese, iron, cobalt, nickel, copper, and zinc.

14. An electrochemical device comprising an anode constructed of a material such that the anode is a chemically rechargeable anode comprising a liquid metal comprising tin, and a solid-state electrolyte which remains solid at an operating temperature of the device, in ionic communication with the anode, wherein the device is capable of producing electricity in the absence of fuel.

15. The device of claim 14, wherein the anode is operable at a temperature of less than about 1500°

C.

16. The device of claim 14, wherein the anode is operable at a temperature of less than about 1300°

C.

17. The device of claim 14, wherein the anode is operable at a temperature of less than about 1000°

C.

18. The device of claim 14, wherein the anode is operable at a temperature from about 300°

C. to about 1500°

C.

19. The device of claim 14, wherein the anode is operable at a temperature from about 300°

C. to about 1300°

C.

20. The device of claim 14, further comprising a source of fuel exposable to the anode.

21. The device of claim 20, wherein the fuel, when exposed to the anode, is in contact with the anode.

22. The device of claim 14, wherein the device is self-repairing.

23. The device of claim 22, wherein the device further comprises a sealant precursor to seal a flaw in a solid state electrolyte when exposed to oxygen.

24. The device of claim 14, further comprising a solid-state cathode in ionic communication with the electrolyte, the solid-state cathode comprising a metal oxide, a mixed metal oxide, and/or a perovskite-type oxide.

25. The device of claim 14, wherein the solid-state electrolyte has a formula (ZrO₂)(HfO₂)_a(TiO₂)_b(Al₂O₃)_c(Y_2O3)_d(M_xO_y)_e where a is from 0 to about 0.2, b is from 0 to about 0.5, c is from 0 to about 0.5, d is from 0 to about 0.5, x is greater than 0and less than or equal to 2, y is greater than 0 and less than or equal to 3, e is from 0 to about 0.5, and M is selected from the group consisting of calcium, magnesium, manganese, iron, cobalt, nickel, copper, and zinc.