Direct liquid fuel cell

• US 8,003,274 B2
• Filed: 10/25/2007
• Issued: 08/23/2011
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: Emergent Power Inc. (Plug Power Inc.)
• Original Assignee: Relion Incorporated (Plug Power Inc.)
• Inventors: Lott, David R., Fuglevand, William A., Spink, Scott A.
• Primary Examiner(s): Kalafut; Stephen J.
• Application Number:
  US11/978,124
• Publication Number:
  US 20090169941A1
• Time in Patent Office: 1,398 Days
• Field of Search: 429/480, 429/481, 429/534
• US Class Current: 429/481
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: H01M 8/2455 with liquid, solid or electrolyte-charged reactants
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A direct liquid fuel cell is disclosed and wherein the fuel cell includes an anode fluid diffusion layer positioned adjacent to the anode side of the membrane electrode assembly, and which consists of, at least in part, a porous electrically conductive ceramic material which is substantially devoid of predetermined fluid passageways. A source of an aqueous hydrocarbon fuel solution is coupled in direct fluid flowing relation relative to the anode fluid diffusion layer, and the anode fluid diffusion layer substantially evenly distributes the aqueous hydrocarbon fuel solution across the active area surface of the anode side of the membrane electrode assembly.

Claims

1. A fuel cell, comprising:

a proton exchange membrane electrode assembly with an anode side and an opposite cathode side, and wherein the anode side has an active area;

an anode fluid diffusion layer positioned adjacent to the anode side of the proton exchange membrane electrode assembly, and which consists of, at least in part, a porous electrically conductive ceramic material which is substantially devoid of predetermined fluid passageways; and

a source of an aqueous hydrocarbon fuel solution which is coupled in direct fluid flowing relation relative to the anode fluid diffusion layer, and wherein the anode fluid diffusion layer substantially evenly distributes the aqueous hydrocarbon fuel solution across the active area of the anode side of the proton exchange membrane electrode assembly.

2. The fuel cell as claimed in claim 1, and wherein the fuel cell generates byproduct gasses during operation on the anode side, and the anode fluid diffusion layer facilitates the operationally effective dissipation of byproduct gasses from the active area of the anode side of the proton exchange membrane electrode assembly.

3. The fuel cell as claimed in claim 2, and wherein the anode fluid diffusion layer has an X, Y, and Z axis, and a range of pore sizes which dissimilar when measured in any one of the X, Y, and/or Z axes.

4. The fuel cell as claimed in claim 2, and further comprising a cathode fluid diffusion layer positioned adjacent to the cathode side of the proton exchange membrane electrode assembly, and which is fabricated of, at least in part, a porous electrically conductive ceramic material which is substantially devoid of predetermined fluid passageways.

5. The fuel cell as claimed in claim 4, and wherein the operation of the fuel cell generates water as a byproduct on the cathode side of the proton exchange membrane electrode assembly, and the cathode fluid diffusion layer retains an operationally effective amount of water in an active area of the cathode side of the proton exchange membrane electrode assembly.

6. The fuel cell as claimed in claim 5, and wherein the proton exchange membrane electrode assembly has an ambient operating temperature, and wherein the cathode fluid diffusion layer retains an operationally effective amount of water in the active area of the cathode side of the proton exchange membrane electrode assembly over an ambient operating temperature range of less than about 60 degrees C.

7. The fuel cell as claimed in claim 4, and wherein the cathode fluid diffusion layer has an X, Y, and Z axis, and a range of pore sizes which is dissimilar when measured in any one of the X, Y, and/or Z axes.

8. The fuel cell as claimed in claim 4, and wherein at least one of the anode or cathode fluid diffusion layers is fabricated from a porous, electrically conductive ceramic material which is selected from the group consisting essentially of titanium diboride, zirconium diboride, molybdenum disilicide, titanium disilicide, titanium nitride, zirconium nitride, vanadium carbide, tungsten carbide, and composites, laminates, and solid solutions thereof.

9. The fuel cell as claimed in claim 1, and wherein the aqueous hydrocarbon fuel solution is selected from the group consisting essentially of aqueous methanol, aqueous ethanol, and aqueous dimethyl ether.

10. A fuel cell, comprising:

a proton exchange membrane electrode assembly having opposite anode and cathode sides, each defining an active area;

at least one porous, electrically conductive, ceramic fluid diffusion layer which is substantially devoid of predetermined passageways positioned in juxtaposed covering relation over at least a part of one of the active areas defined by the anode and cathode sides;

a source of an aqueous hydrocarbon fuel disposed in fluid flowing relation relative to the anode side of the proton exchange membrane electrode assembly; and

a source of an oxidant disposed in fluid flowing relation relative to the cathode side of the proton exchange membrane electrode assembly; and

wherein the operation of the fuel cell generates byproduct gasses on the anode side, and byproduct water on the cathode side, and wherein the porosities of the respective porous electrically conductive ceramic fluid diffusion layers are selected so as to facilitate the substantially even distribution of the aqueous hydrocarbon fuel over the active area of the anode side, while simultaneously facilitating the operationally effective dissipation of byproduct gasses from the active area of the anode side, and the simultaneous retention of an operationally effective amount of byproduct water in the active area of the cathode side so as to facilitate the operation of the fuel cell.

11. The fuel cell as claimed in claim 10, and wherein the aqueous hydrocarbon fuel is selected from the group consisting essentially of aqueous methanol, aqueous ethanol, and aqueous dimethyl ether.

12. The fuel cell as claimed in claim 10, and wherein the at least one porous, electrically conductive, ceramic fluid diffusion layer is fabricated from a ceramic material which is selected from the group consisting essentially of titanium diboride, zirconium diboride, molybdenum disilicide, titanium disilicide, titanium nitride, zirconium nitride, vanadium carbide, tungsten carbide, and composites, laminates, and solid solutions thereof.

13. A fuel cell comprising:

a proton exchange membrane with an anode side and an opposite cathode side, and wherein the anode side and the cathode side each have an active area;

an anode catalyst layer positioned in juxtaposed relation relative to the anode side of the proton exchange membrane;

a cathode catalyst layer positioned in juxtaposed relation relative to the cathode side of the proton exchange membrane;

an anode fluid diffusion layer positioned in juxtaposed relation relative to the anode catalyst layer, and which consists, at least in part, of a porous electrically conductive ceramic material which is substantially devoid of predetermined passageways;

a cathode fluid diffusion layer positioned in juxtaposed relation relative to the cathode catalyst layer, and which consists, at least in part, of a porous electrically conductive ceramic material which is substantially devoid of predetermined passageways;

a first current collecting separator plate positioned adjacent to the anode catalyst layer and having a region which is positioned in at least partially covering relation relative to the active area of the anode side; and

a second current collecting separator plate positioned adjacent to the cathode catalyst layer and having a region which is positioned in at least partially covering relation relative to the active area of the cathode side, and wherein the regions of the first and second current collecting separator plates which are positioned in at least partial covering relation relative to the respective active areas of the anode and cathode sides of the proton exchange membrane are substantially devoid of predetermined passageways for accommodating the flow of a flowable reactant.

14. The fuel cell as claimed in claim 13, and further comprising a source of an aqueous hydrocarbon fuel solution which is coupled in direct fluid flowing relation relative to the anode fluid diffusion layer, and wherein the anode fluid diffusion layer substantially evenly distributes the aqueous hydrocarbon fuel solution across the active area of the anode side of the proton exchange membrane.

15. The fuel cell as claimed in claim 14, and wherein the aqueous hydrocarbon fuel solution is selected from the group consisting essentially of aqueous methanol, aqueous ethanol, and aqueous dimethyl ether.

16. The fuel cell as claimed in claim 13, and wherein the operation of the fuel cell generates byproduct gasses on the anode side, and byproduct water on the cathode side, and wherein the anode fluid diffusion layer facilitates the operationally effective dissipation of byproduct gasses from the active area of the anode side of the proton exchange membrane, and the cathode fluid diffusion layer retains an operationally effective amount of byproduct water in the active area of the cathode side of the proton exchange membrane so as to facilitate the operation of the fuel cell.

17. A fuel cell, comprising:

a proton exchange membrane electrode assembly with an anode side, and an opposite cathode side;

at least one fluid diffusion layer disposed adjacent to the anode side of the proton exchange membrane electrode assembly, and wherein the at least one fluid diffusion layer is fabricated, at least in part, from a porous, electrically conductive ceramic material which is selected from the group consisting essentially of titanium diboride, zirconium diboride, molybdenum disilicide, titanium disilicide, titanium nitride, zirconium nitride, vanadium carbide, tungsten carbide, and composites, laminates, and solid solutions thereof, wherein the at least one fluid diffusion layer is substantially devoid of predetermined fluid passageways; and

,

a source of an aqueous hydrocarbon fuel solution which is coupled in direct fluid flowing relation relative to the at least one fluid diffusion layer, and wherein the at least one fluid diffusion layer substantially evenly distributes the aqueous hydrocarbon fuel solution across an active area of the anode side of the proton exchange membrane electrode assembly.

18. The fuel cell as claimed in claim 17, and wherein the operation of the fuel cell generates byproduct gasses on the anode side of the proton exchange membrane electrode assembly, and the fluid diffusion layer on the anode side facilitates the operationally effective dissipation of byproduct gasses from the active area of the anode side of the proton exchange membrane electrode assembly.

19. The fuel cell as claimed in claim 17, wherein the at least one fluid diffusion layer comprises another fluid diffusion layer that is disposed adjacent to the cathode side of the proton exchange membrane electrode assembly, and wherein the another fluid diffusion layer is substantially devoid of predetermined fluid passageways.

20. The fuel cell as claimed in claim 19, and wherein the operation of the fuel cell generates byproduct water on the cathode side of the proton exchange membrane electrode assembly, and the diffusion layer retains an operationally effective amount of byproduct water in an active area of the cathode side of the proton exchange membrane electrode assembly so as to facilitate the operation of the fuel cell.

21. A fuel cell comprising:

a proton exchange membrane electrode assembly with an anode side and an opposite cathode side, and wherein the anode side and the cathode side each have an active area;

an anode fluid diffusion layer positioned in juxtaposed relation relative to the anode side of the proton exchange membrane electrode assembly, and which consists, at least in part, of a porous electrically conductive ceramic material which is substantially devoid of predetermined passageways;

a cathode fluid diffusion layer positioned in juxtaposed relation relative to the cathode side of the proton exchange membrane electrode assembly, and which consists, at least in part, of a porous electrically conductive ceramic material which is substantially devoid of predetermined passageways;

a source of an aqueous hydrocarbon fuel solution which is coupled in direct fluid flowing relation relative to the anode fluid diffusion layer, and wherein the anode fluid diffusion layer substantially evenly distributes the aqueous hydrocarbon fuel solution across the active area of the anode side of the proton exchange membrane electrode assembly, and wherein the operation of the fuel cell generates byproduct gasses on the anode side and byproduct water on the cathode side, and wherein the anode fluid diffusion layer facilitates the operationally effective dissipation of byproduct gasses from the active area of the anode side of the proton exchange membrane, and the cathode diffusion layer retains an operationally effective amount of byproduct water in the active area of the cathode side of the proton exchange membrane over an ambient operating temperature range of less than about 60 degrees C.;

a first current collecting separator plate positioned adjacent to the anode side and having a region which is in partial covering relation relative thereto; and

a second current collecting separator plate positioned adjacent to the cathode side and having a region which is in partial covering relation relative thereto, and wherein the regions of the first and second current collecting separator plates which are in at least partial covering relation relative to the respective active areas of the anode and cathode sides of the proton exchange membrane electrode assembly, are substantially devoid of predetermined passageways for accommodating the flow of the aqueous hydrocarbon fuel solution.

22. The fuel cell system as claimed in claim 21, and wherein at least one of the anode or cathode fluid diffusion layers is fabricated from a ceramic material which is selected from the group consisting essentially of titanium diboride, zirconium diboride, molybdenum disilicide, titanium disilicide, titanium nitride, zirconium nitride, vanadium carbide, tungsten carbide, and composites, laminates, and solid solutions thereof.

23. The fuel cell as claimed in claim 21, and wherein the aqueous hydrocarbon fuel solution is selected from the group consisting essentially of aqueous methanol, aqueous ethanol, and aqueous dimethyl ether.