Fuel cell with transport flow across gap

• US 9,780,394 B2
• Filed: 12/21/2007
• Issued: 10/03/2017
• Est. Priority Date: 12/21/2006
• Status: Active Grant

• Current Assignee: Arizona Board of Regents (University of Arizona)
• Original Assignee: Arizona Board of Regents (University of Arizona)
• Inventors: Friesen, Cody A., Hayes, Joel R.
• Primary Examiner(s): Gilliam, Barbara
• Assistant Examiner(s): Arciero, Adam A
• Application Number:
  US11/962,803
• Publication Number:
  US 20100119883A1
• Time in Patent Office: 3,574 Days
• Field of Search: None
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 8/04089 of gaseous reactants
• CPC Class Codes: H01M 8/04186 of liquid-charged or electrolyte-charged reactants
• CPC Class Codes: H01M 8/08 Fuel cells with aqueous electrolytes
• CPC Class Codes: H01M 8/22 Fuel cells in which the fuel is based on materials comprising carbon or oxygen or hydrogen and other elements; Fuel cells in which the fuel is based on materials comprising only elements other than carbon, oxygen or hydrogen
• CPC Class Codes: H01M 8/2455 with liquid, solid or electrolyte-charged reactants
• CPC Class Codes: H01M 8/247 Arrangements for tightening a stack, for accommodation of a stack in a tank or for assembling different tanks
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

The present invention relates to a fuel cell with a gap for transport flow of an electrolyte containing charge carrying ions from either a fuel or an oxidizer between anode and a cathode.

Claims

1. An electrochemical cell for use with an electrode and reactants comprising a fuel and an oxidizer, comprising:

electrodes comprising;

(i) an anode communicated to the fuel source for receiving the fuel and oxidizing the fuel into at least oxidized fuel ions and electrons, and (ii) a cathode communicated to the oxidizer source for accepting electrons and reducing the oxidizer into at least reduced oxidizer ions;

the anode and the cathode being spaced apart to define a gap between opposing gap facing surfaces thereof and being connectable to a load;

a first input into the cell for directly delivering a first of the reactants selected from the group consisting of;

the fuel and the oxidizer to a first of the electrodes to produce a first output;

a second input into the cell for directly delivering a second of the reactants to a second of the electrodes, the second of the reactants being different from the first reactant, and the second input being separate from the first input to the first of the electrodes and configured for combining with the first output, and wherein the fuel and the oxidizer are each input from a source external to the fuel cell;

a flow generator for generating a transport flow comprising the electrolyte and the ions formed from the first reactant oxidized or reduced at the first electrode that exits the gap facing surface of the first electrode and into the gap such that the transport flow flows essentially perpendicularly to the opposing gap facing surfaces of the electrodes and transports the ions of the first output formed from the first reactant for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to form a second output that exits the second electrode, the second output comprising a mixture which results in a product and the electrolyte exiting the second electrode.

2. An electrochemical cell according to claim 1, wherein said flow generator is configured to generate said transport flow across said gap from the first electrode to the second electrode.

3. A fuel cell for use with an electrolyte and reactants comprising a fuel and an oxidizer comprising:

electrodes comprising;

(i) an anode for oxidizing the fuel into at least oxidized fuel ions and electrons, and (ii) a cathode for accepting electrons and reducing the oxidizer into at least reduced oxidizer ions;

the anode and the cathode being spaced apart to define a gap between opposing gap facing surfaces thereof and being connectable to a load;

a first input into the cell for directly delivering a first of the reactants selected from the group consisting of;

the fuel and the oxidizer to a first of the electrodes to produce a first output, the first input being upstream of or at the first electrode;

a second input into the cell for directly delivering a second of the reactants to a second of the electrodes, the second of the reactants being different from the first reactant, and the second input being separate from and downstream of the first electrode such that the second of the reactants is configured for combining with the first output, and wherein the fuel and the oxidizer are each input from a source external to the fuel cell; and

a flow generator for generating a transport flow of the electrolyte exiting the gap facing surface of the first electrode and flowing essentially perpendicularly to the opposing gap facing surfaces of both the electrodes to the gap facing surface of the second electrode across the gap to transport the ions of the first output formed from the first reactant oxidized or reduced at said first electrode for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to form a second output that exits the second electrode, the second output comprising a mixture which results in a product and the electrolyte exiting the second electrode.

4. A fuel cell according to claim 3, wherein the flow generator is configured to generate said transport flow across the gap at a rate higher than a diffusion rate of the second reactant oxidized or reduced at the second electrode within the electrolyte to essentially prevent diffusion thereof to said first electrode.

5. A fuel cell according to claim 4, wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an anode-to-cathode direction.

6. A fuel cell according to claim 4, further comprising a fuel source comprising the fuel and communicated to the anode.

7. A fuel cell according to claim 6, wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an anode-to-cathode direction,

wherein the fuel Source is part of a fuel and electrolyte source communicated to the anode and comprising the fuel and the electrolyte.

8. A fuel cell according to claim 4, further comprising an oxidizer source comprising the oxidizer and communicated to the cathode.

9. A fuel cell according to claim 8, wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an anode-to-cathode direction,

wherein the oxidizer source is communicated to the gap to deliver the oxidizer to the transport flow between the anode and the cathode.

10. A fuel cell according to claim 4, wherein the cathode has an anode receiving space therein and wherein the anode is received within the anode receiving space with the gap between the anode and the cathode.

11. A fuel cell according to claim 10, wherein the cathode has an annular configuration surrounding the anode receiving space.

12. A fuel cell according to claim 11, wherein the cathode has a circular configuration with an inner diameter and an outer diameter.

13. A fuel cell according to claim 12, wherein the anode has a circular configuration with an outer diameter smaller than the inner diameter of the cathode to define the gap.

14. A fuel cell according to claim 4, wherein the flow generator is a pump operable to generate said transport flow.

15. A fuel cell according to claim 4, wherein the flow generator is a rotary driver operable to rotate the anode and the cathode so as to generate said transport flow by centrifugal force.

16. A fuel cell according to claim 7, wherein the fuel and electrolyte source comprises a mixture of the fuel and the electrolyte.

17. A fuel cell according to claim 7, wherein the fuel and electrolyte source comprises a first chamber for containing the electrolyte and a second chamber for containing the fuel, each of the first and second chambers being communicated to the anode.

18. A, fuel cell according to claim 6, wherein the fuel is a hydrocarbon.

19. A fuel cell according to claim 18, wherein the fuel is methanol.

20. A fuel cell according to claim 4, wherein each of the anode and the cathode is non-selective for both the fuel oxidation and oxidizer reduction.

21. A fuel cell according to claim 18, further comprising an oxidizer source comprising the oxidizer, wherein the oxidizer is oxygen.

22. A fuel cell according to claim 4, further comprising an oxidizer source comprising the oxidizer and communicated to the cathode:

wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, the flow generator is configured to generate the transport flow in an anode-to-cathode direction; and

wherein the flow generator is configured to generate said transport flow across the gap at a rate higher than a diffusion rate of the oxidizer within the electrolyte to essentially prevent diffusion of the oxidizer to the anode.

23. A fuel cell according to claim 6, wherein the cathode and the oxidizer are the first electrode and the first reactant, the anode and the fuel are the second electrode and the second reactant, the flow generator is configured to generate the transport flow in an cathode-to-anode direction;

and

wherein the flow generator is configured to generate said transport flow across the gap at a rate higher than a diffusion rate of the fuel within the electrolyte to essentially prevent diffusion of the fuel to the porous body of the cathode.

24. A fuel cell according to claim 3, further comprising a housing including a first plate and a second plate, the anode and the cathode being disposed between the first and second plates.

25. A fuel cell according to claim 3, further comprising a conduit extending between the anode and the cathode and defining said gap, and wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an anode-to-cathode direction,

the first input being a fuel inlet of the conduit for connection to a fuel and electrolyte source, the fuel inlet being located upstream of the anode such that the fuel and electrolyte flows through the anode exiting its gap facing surface and into the gap;

the second input being an oxidizer inlet of the conduit for connection to an oxidizer source, the oxidizer inlet being separate from and downstream of the anode at the gap such that the oxidizer is directly delivered to the transport flow between the anode and the cathode so that the electrolyte, oxidized fuel, and the oxidizer flow to and through the opposing gap facing Surface of the cathode for reduction of the oxidizer at the cathode and reaction of the reduced oxidizer and the oxidized fuel.

26. A fuel cell system comprising:

a fuel source comprising a fuel;

an oxidizer source comprising an oxidizer, the fuel and the oxidizer being reactants;

electrodes comprising;

(a) an anode communicated to the fuel source for receiving the fuel and oxidizing the fuel into at least oxidized fuel ions and electrons, and (b) a cathode communicated to the oxidizer source for accepting electrons and reducing the oxidizer into at least reduced oxidizer ions;

the anode and the cathode being spaced apart to define a gap between opposing gap facing surfaces thereof and being connectable to a load;

a first input into the cell for directly delivering a first of the reactants selected from the group consisting of;

the fuel and the oxidizer to a first of the electrodes to produce a first output, the first input being upstream of or at the first electrode;

a second input into the cell for directly delivering a second of the reactants to a second of the electrodes, the second of the reactants being different from the first reactant, and the second input being separate from and downstream of the first electrode such that the second of the reactants is configured for combining with the first output, and wherein the fuel and the oxidizer are each input from a source external to the fuel cell;

an electrolyte in the gap between the anode and the cathode;

a flow generator for generating a transport flow of the electrolyte exiting the gap facing surface of the first electrode and flowing essentially perpendicularly to the opposing gap facing surfaces of both the electrodes to the gap facing surface of the second electrode across the gap to transport the ions of the first output formed from the first reactant oxidized or reduced at said first electrode for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to form a second output that exits the second electrode, the second output comprising a mixture which results in a product and the electrolyte exiting the second electrode.

27. A fuel cell system according to claim 26, wherein the flow generator is configured to generate said transport flow across the gap at a rate higher than a diffusion rate of the second reactant oxidized or reduced at the second electrode within the electrolyte to essentially prevent diffusion thereof across the gap to said first electrode.

28. A fuel cell system according to claim 26, further comprising a conduit extending between the anode and the cathode and defining said gap, and wherein the anode and the fuel are the first electrode and the first reactant, the cathode and the oxidizer are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an anode-to-cathode direction,

wherein the fuel source is a fuel and electrolyte source,

the first input being a fuel inlet of the conduit connected to a fuel and electrolyte source, the fuel inlet being located upstream of the anode such that the fuel and electrolyte flows through the anode exiting its gap facing surface and into the gap;

the second input being an oxidizer inlet of the conduit connected to the oxidizer source, the oxidizer inlet being separate from and downstream of the anode at the gap such that the oxidizer is directly delivered to the transport flow between the anode and the cathode so that the electrolyte, oxidized fuel, and the oxidizer flow to and through the opposing gap facing surface of the cathode for reduction of the oxidizer at the cathode and reaction of the reduced oxidizer and the oxidized fuel.

29. A fuel cell system according to claim 26, further comprising a conduit extending between the anode and the cathode and defining said gap, and wherein the cathode and the oxidizer are the first electrode and the first reactant, the anode and the fuel are the second electrode and the second reactant, and the flow generator is configured to generate the transport flow in an cathode-to-anode direction,

wherein the oxidizer source is an oxidizer and electrolyte source,

the first input being an oxidizer inlet of the conduit connected to the oxidizer and electrolyte source, the oxidizer inlet being located upstream of the cathode such that the oxidizer and electrolyte flows through the cathode exiting its gap facing surface and into the gap;

the second input being a fuel inlet of the conduit connected to the fuel source, the fuel inlet being separate from and downstream of the cathode at the gap between the anode and the cathode such that the oxidizer is directly delivered to the transport flow between the cathode and the anode so that the electrolyte, reduced oxidizer, and the fuel flow to and through the opposing gap facing surface of the anode for oxidation of the fuel at the anode and reaction of the oxidized fuel and the reduced oxidizer.

30. A method for generating electrical current using a electrochemical cell for use with an electrolyte and reactants comprising a fuel and an oxidizer, comprising:

electrodes comprising;

(i) an anode for oxidizing the fuel into at least oxidized fuel ions and electrons, and (ii) a cathode for accepting electrons and reducing the oxidizer into at least reduced oxidizer ions;

the anode and the cathode being spaced apart to define a gap between opposing gap facing surfaces thereof and being connectable to a load;

a first input into the cell for directly delivering a first of the reactants selected from the group consisting of;

the fuel and the oxidizer to a first of the electrodes to produce a first output;

a second input into the cell for directly delivering a second of the reactants to a second of the electrodes, the second of the reactants being different from the first reactant, and the second input being separate from the first input to the first of the electrodes such that the second of the reactants is configured for combining with the first output, and wherein the fuel and the oxidizer are each input from a source external to the fuel cell;

a flow generator for generating a transport flow comprising the electrolyte and the ions formed from the first reactant oxidized or reduced at the first electrode that flows from the first electrode and into the gap such that the transport flow transports the ions formed from the first reactant for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, the method comprising;

delivering the first of the reactants to the first of the electrodes via the first input to produce the first output;

delivering a second of the reactants to the second of the electrodes via the second input, for combining with the first output;

wherein the transport flow comprising the electrode and the ions formed from the first reactant oxidized or reduced at the first electrode exist the gap facing surface of the first electrode and flows into the gap as the first output, the transport flow flowing essentially perpendicularly to the opposing gap facing surfaces of the electrodes and transporting the ions formed from the first reactant for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to form a second output that exits the second electrode, the second output comprising a mixture which results in a product and the electrolyte exiting the second electrode.

31. A method according to claim 30, wherein said transport flow flows across the gap from the first electrode to the second electrode.

32. A method for generating electrical current using a fuel cell for use with an electrolyte and reactants comprising a fuel and an oxidizer comprising:

electrodes comprising;

(i) an anode for oxidizing the fuel into at least oxidized fuel ions and electrons, and (ii) a cathode for accepting electrons and reducing the oxidizer into at least reduced oxidizer ions;

the anode and the cathode being spaced apart to define a gap between opposing gap facing surfaces thereof and being connectable to a load;

a first input into the cell for directly delivering a first of the reactants selected from the group consisting of;

the fuel and the oxidizer to a first of the electrodes to produce a first output, the first input being upstream of or at the first electrode;

a second input into the cell for directly delivering a second of the reactants to a second of the electrodes, the second of the reactants being different from the first reactant, and the second input being separate from and downstream of the first electrode such that the second of the reactants is configured for combining with the first output, and wherein the fuel and the oxidizer are each input from a source external to the fuel cell;

a flow generator for generating a transport flow of the electrolyte exiting the gap facing surface of the first electrode and flowing essentially perpendicularly to the opposing gap facing surfaces of both the electrodes to the gap facing surface of the second electrode across the gap to transport the ions of the first output formed from the first reactant oxidized or reduced at said first electrode for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to form a second output that exits the second electrode, the second output comprising a mixture which results in a product and the electrolyte exiting the second electrode;

the method comprising;

delivering the first of the reactants to the first of the electrodes via the first input upstream of or at the first electrode;

delivering a second of the reactants to the second of the electrodes via the second input downstream of the first electrode at the gap or the second electrode;

generating the transport flow of the electrolyte across the gap to transport the ions of the first output formed from the first reactant oxidized or reduced at said first electrode for reaction with the ions formed from the second reactant oxidized or reduced at the second electrode, to produce the second output exiting the second electrode,

wherein the generated transport flow exits the gap faxing surface of the first electrode and flows essentially perpendicularly to the opposing gap facing surfaces of both the electrodes and through the gap facing surface of the second electrode.

33. A method according to claim 32, wherein said transport flow flows across the gap at a rate higher than a diffusion rate of the second reactant oxidized or reduced at the second electrode within the electrolyte to essentially prevent diffusion thereof to said first electrode.

34. A method according to claim 32, wherein the transport flow flows in an anode-to-cathode direction, the fuel and the anode being the first reactant and the first electrode and the oxidizer and the cathode being the second reactant and the second electrode.

35. A method according to claim 32, wherein the anode comprises a porous body that receives the fuel.

36. A method according to claim 32, wherein the cathode comprises a porous body that receives the oxidizer.

37. A method according to claim 35, wherein the cathode comprises a porous body that receives the oxidizer.

38. A method according to claim 37, wherein the porous body of the anode comprises a catalyst material, and wherein the catalyst material catalyzes the fuel oxidation.

39. A method according to claim 37, wherein the porous body of the cathode comprises a catalyst material, and wherein the catalyst material catalyzes the oxidizer reduction.

40. A method according to claim 38, wherein the porous body of the cathode comprises a catalyst material, and wherein the catalyst material catalyzes the oxidizer reduction.

41. A method according to claim 32, wherein the cathode has an anode receiving space therein and wherein the anode is received within the anode receiving space with the gap between the anode and the cathode.

42. A method according to claim 41, wherein the cathode has an annular configuration surrounding the anode receiving space.

43. A method according to claim 42, wherein the cathode has a circular configuration with an inner diameter and an outer diameter.

44. A method according to claim 43, wherein the anode has a circular configuration with an outer diameter smaller than the inner diameter of the cathode to define the gap.

45. A method according to claim 32, wherein a pump generates said transport flow.

46. A method according to claim 32, wherein the anode and the cathode are rotated so as to generate said transport flow by centrifugal force.

47. A method according to claim 32, wherein the oxidizer is oxygen.

48. A method according to claim 47, wherein the oxygen is present in ambient air.

49. A method according to claim 34, wherein the fuel cell comprises a fuel and electrolyte source communicated to the anode and comprising the fuel and the electrolyte.

50. A method according to claim 49, wherein the fuel and electrolyte source comprises a mixture of the fuel and the electrolyte, and wherein the fuel and the electrolyte are provided to the anode by delivering the mixture.

51. A method according to claim 50, wherein the fuel and electrolyte source comprises a first chamber for containing the electrolyte and a second chamber for containing the fuel, each of the first and second chambers being communicated to the anode, wherein the fuel and the electrolyte are provided to the anode from the first and second chambers, respectively.

52. A method according to claim 32, wherein the fuel is a hydrocarbon.

53. A method according to claim 52, wherein the fuel is methanol.

54. A method according to claim 53, wherein each of the anode and the cathode is non-selective for both fuel oxidation and oxidizer reduction.

55. A method according to claim 53, wherein the electrolyte is an aqueous solution.

56. A method according to claim 32, wherein the transport flow flows in an anode-to-cathode direction, the fuel and the anode being the first reactant and the first electrode and the oxidizer and the cathode being the second reactant and the second electrode;

and

wherein said transport flow is generated at a rate higher than a diffusion rate of the oxidizer within the electrolyte to essentially prevent diffusion of the oxidizer to the anode.

57. A method according to claim 32, wherein the transport flow flows in an cathode-to-anode direction, the oxidizer and the cathode being the second reactant and the second electrode and the fuel and the anode being the second reactant and the second electrode;

and

wherein said transport flow is generated at a rate higher than a diffusion rate of the fuel within the electrolyte to essentially prevent diffusion of the fuel to the cathode.