MICRO FUEL CELL HAVING MACROPOROUS METAL CURRENT COLLECTORS

• US 20080182012A1
• Filed: 01/31/2007
• Published: 07/31/2008
• Est. Priority Date: 01/31/2007
• Status: Abandoned Application

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Parekh, Kajal, Krishnan, Ramkumar, Fisher, Allison M.
• Application Number:
  US11/669,720
• Publication Number:
  US 20080182012A1
• Time in Patent Office: Days
• US Class Current: 427/115
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8807 Gas diffusion layers
• CPC Class Codes: H01M 4/881 Electrolytic membranes
• CPC Class Codes: H01M 4/8853 Electrodeposition
• CPC Class Codes: H01M 4/8867 Vapour deposition
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H01M 8/0232 Metals or alloys
• CPC Class Codes: H01M 8/0234 Carbonaceous material
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/0258 characterised by the configuration of channels, e.g. by the flow field of the reactant or coolant
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1097 Fuel cells applied on a support, e.g. miniature fuel cells deposited on silica supports
• CPC Class Codes: H01M 8/2418 Grouping by arranging unit cells in a plane H01M8/2425, H01M8/244 take precedence
• CPC Class Codes: H01M 8/2483 characterised by internal manifolds
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A method is provided for fabricating a hybrid gas diffusion layer/current collector/electrocatalyst structure (28) suitable for 3D microfuel cell devices (180). The method comprises forming a macroporous electrically conductive structure (28) on a substrate (12, 112) positioned such that a plurality of cathode current collector/GDL (168) and anode current collector/GDL (166) are formed. An electrocatalyst material (158) is deposited in contact with these structures, completing the formation of cathode (168) and anode (166) hybrid current collector/GDL/electrocatalyst structures. When electrolyte (158) is positioned between the electrocatalyst material (158) contacting the cathode collector (168) and the electrocatalyst material (158) contacting each of the plurality of anode collectors (166), the resulting MEA is suitable for use in a micro fuel cell device.

Claims

1. A method comprising:

assembling an electrode of an energy generation device comprising;

forming a porous conductive material;

conformally coating the porous conductive material with a catalyst layer comprising one or more materials that are electrically and ionically conductive; and

conformally forming an electrolyte layer on the catalyst layer.

2. The method of claim 1 wherein the assembling step comprises forming a colloidal crystal template.

3. The method of claim 1 wherein the conformally coating the catalyst layer step comprises forming the catalyst layer by one of a) chemical deposition from a solution containing catalyst precursors, b) electrodeposition from a solution containing catalyst precursors, c) electrophoretic from a solution containing catalyst precursors, d) layer by layer electrostatic deposition, and e) vapor deposition.

4. The method of claim 3 wherein the forming step comprises forming a conductive material having a porosity defining openings of greater than 50.0 nanometers across.

5. The method of claim 1 wherein the forming step comprises forming the conductive material by one of a) chemical deposition from a solution containing conductive ions, b) electrodeposition from a solution containing conductive ions, and c) vapor deposition.

6. The method of claim 1 wherein the forming step comprises forming a conductive material selected from the group consisting of gold, carbon, platinum, silver, aluminum nickel, copper, iron, zinc, chromium, cobalt, magnesium, technetium, rhodium, cadmium, indium, tin, antimony, tellurium, selenium, rhenium, osmium, iridium, mercury, lead, and bismuth, or alloys thereof.

7. The method of claim 1 wherein the conformally forming an electrolyte layer comprises forming the electrolyte layer by one of a) chemical deposition from a solution containing polymer precursors, b) electrodeposition from a solution containing polymer precursors, and c) layer by layer electrostatic deposition.

8. The method of claim 1 wherein the assembling step comprises forming a plurality of cathode electrodes and a plurality of anode electrodes, the method further comprising positioning an electrolyte between each of the plurality of cathode electrodes and each of the plurality of anode electrodes.

9. A method comprising:

assembling an electrode of an energy generation device comprising;

forming a porous electrolyte layer;

conformally coating the porous electrolyte layer with a catalyst layer comprising one or more materials that are electrically and ionically conductive; and

conformally coating the catalyst layer with a porous conducting material.

10. The method of claim 9 wherein the assembling step comprises forming a colloidal crystal template.

11. The method of claim 9 wherein the conformally coating the porous electrolyte layer comprises forming the catalyst layer by one of a) chemical deposition from a solution containing catalyst precursors, b) electrodeposition from a solution containing catalyst precursors, c) electrophoretic from a solution containing catalyst precursors, d) layer by layer electrostatic deposition, and e) vapor deposition.

12. The method of claim 11 wherein the forming step comprises forming an electrolyte layer having a porosity defining openings of greater than 50.0 nanometers across.

13. The method of claim 9 wherein the conformally coating the catalyst layer comprises forming the porous conductive layer by one of a) chemical deposition from a solution containing conductive ions, b) electrodeposition from a solution containing conductive ions, c) vapor deposition, and d) selective dealloying.

14. The method of claim 9 wherein the conformally coating the catalyst layer step comprises forming a conductive material selected from the group consisting of gold, carbon, platinum, silver, aluminum nickel, copper, iron, zinc, chromium, cobalt, magnesium, technetium, rhodium, cadmium, indium, tin, antimony, tellurium, selenium, rhenium, osmium, iridium, mercury, lead, and bismuth, or alloys thereof.

15. The method of claim 9 wherein the forming step comprises forming the porous electrolyte layer by one of a) chemical deposition from a solution containing polymer precursors, b) electrodeposition from a solution containing polymer precursors, and c) layer by layer electrostatic deposition.

16. A method comprising:

forming a fuel cell with an electrode assembly, comprising;

dispensing a solution onto a substrate, the solution including macroscale size particles;

removing the solution to create an array of particles defining a first void within the array;

filling the first void with a precursor;

reducing the precursor to a conductive material;

removing the plurality of particles, thereby forming a macroporous template comprising the conductive material and defining a second void; and

forming an electrocatalyst within the second void.

17. The method of claim 16 wherein the removing the plurality of particles comprises forming a colloidal crystal template.

18. The method of claim 16 wherein the reducing step forms a conductive material having a porosity defining openings of greater than 50.0 nanometers across.

19. The method of claim 16 wherein the forming a macroporous template comprises:

forming a plurality of cathode collectors and a plurality of anode collectors; and

the method further comprising;

positioning an electrolyte between each of the plurality of cathode collectors and each of the plurality of anode collectors.

20. The method of claim 16 further comprising:

forming first and second electrical conductors accessible at a first side of a substrate;

etching the substrate to provide a plurality of channels;

patterning the macroporous template over the first side of the substrate to form a plurality of anode current collectors in contact with the first electrical conductor, and a plurality of cathode current collectors in contact with the second electrical conductor, one each of the plurality of anode current collectors formed over one of the plurality of channels;

depositing an electrolyte between each of the plurality of anode current collectors and each of the plurality of cathode current collectors; and

capping the plurality of anode current collectors on a side opposed to the first side of the substrate.