Scalable all-polymer fuel cell

• US 20020150804A1
• Filed: 04/11/2002
• Published: 10/17/2002
• Est. Priority Date: 07/19/2000
• Status: Active Grant

• Current Assignee: Johns Hopkins University
• Original Assignee: Johns Hopkins University
• Inventors: Saffarian, Hassan M., Srinivasan, Rengaswamy, Raghu, Surya
• Granted Patent: US 6,872,486 B2
• Time in Patent Office: Days
• US Class Current: 429/32
• CPC Class Codes: H01M 2300/0082 Organic polymers
• CPC Class Codes: H01M 4/92 Metals of platinum group H01M4/94 , H01M4/9058 take precedence
• CPC Class Codes: H01M 4/921 Alloys or mixtures with metallic elements
• CPC Class Codes: H01M 8/0213 Gas-impermeable carbon-containing materials
• CPC Class Codes: H01M 8/0221 Organic resins; Organic polymers
• CPC Class Codes: H01M 8/0247 characterised by the form characterised by a channel configuration H01M8/0258
• CPC Class Codes: H01M 8/0256 Vias, i.e. connectors passing through the separator material
• CPC Class Codes: H01M 8/026 characterised by grooves, e.g. their pitch or depth
• CPC Class Codes: H01M 8/04067 Heat exchange or temperature measuring elements, thermal insulation, e.g. heat pipes, heat pumps, fins
• CPC Class Codes: H01M 8/04164 by condensers, gas-liquid separators or filters
• CPC Class Codes: H01M 8/04194 Concentration measuring cells
• CPC Class Codes: H01M 8/04201 Reactant storage and supply, e.g. means for feeding, pipes
• CPC Class Codes: H01M 8/0668 Removal of carbon monoxide or carbon dioxide
• CPC Class Codes: H01M 8/1009 with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: H01M 8/1011 Direct alcohol fuel cells [DAFC], e.g. direct methanol fuel cells [DMFC]
• CPC Class Codes: H01M 8/1023 having only carbon, e.g. polyarylenes, polystyrenes or polybutadiene-styrenes
• CPC Class Codes: H01M 8/1039 halogenated, e.g. sulfonated polyvinylidene fluorides
• CPC Class Codes: H01M 8/2418 Grouping by arranging unit cells in a plane H01M8/2425, H01M8/244 take precedence
• CPC Class Codes: H01M 8/2455 with liquid, solid or electrolyte-charged reactants
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A methanol-air fuel cell consisting of a stack of sub-fuel cells, each sub-fuel cell comprising a proton conducting polymer membrane, with each membrane having an array of 1-cm²-anode unit cells on one side and an array of cathode unit cells on the other. A thin polymer film, with openings for the unit cells and plated with pre-patterned lines of electrical leads, is placed on each side of the membrane to collect the current from each unit cell. A polymer fuel-feed plate is placed on the thin polymer film on each side of the membrane to feed methanol and oxygen to the electrodes.

Claims

1. A sub-fuel cell comprising:

a plurality of unit cells, comprising anode unit cells and cathode unit cells;

a proton conducting polymer membrane, the anode unit cells being placed on one side of the membrane and the cathode unit cells being placed on the other side of the membrane opposite the anode unit cells;

a thin polymer film having openings for the anode and cathode unit cells and electrical leads, the thin polymer film being placed on each side of the proton conducting polymer membrane and around the anode unit cells and the cathode unit cells to collect electric current from each unit cell; and

two fuel-feed plates having spaces corresponding to the anode unit cells and the cathode unit cells and interconnecting channels for supplying fuel to the anode unit cells and the cathode unit cells, one fuel-feed plate being placed on the side of the thin polymer film having the anode unit cells and one fuel-feed plate being placed on the side of the thin polymer film having the cathode unit cells.

2. A fuel cell comprising a plurality of sub-fuel cells as recited in claim 1, the plurality of sub-fuel cells being stacked together to form the fuel cell.

3. The fuel cell as recited in claim 2, wherein each fuel-feed plate has spaces and interconnecting channels on both sides of the plate thereby allowing one fuel-feed plate to provide fuel to two adjoining sub-fuel cells.

4. The sub-fuel cell as recited in claim 1, wherein the anode unit cells are coated with platinum and ruthenium and the cathode unit cells are coated with platinum.

5. The sub-fuel cell as recited in claim 1, wherein the proton conducting polymer membrane comprises Nafion.

6. The sub-fuel cell as recited in claim 5, wherein the Nafion comprises Nafion-117.

7. The sub-fuel cell as recited in claim 1, wherein the thin polymer film is Mylar.

8. The sub-fuel cell as recited in claim 7, wherein the Mylar is plated with pre-patterned lines of electrical leads.

9. The sub-fuel cell as recited in claim 8, wherein the electrical leads are gold.

10. The sub-fuel cell as recited in claim 1, wherein the fuel-feed plates comprise a polymer.

11. The sub-fuel cell as recited in claim 10, wherein the polymer is a phenolic resin.

12. The sub-fuel cell as recited in claim 10, wherein the polymer is polychlortrifluoroethylene.

13. The sub-fuel cell as recited in claim 4, wherein an organic compound is added to the platinum.

14. The sub-fuel cell as recited in claim 13, wherein the organic compound is uracil.

15. The sub-fuel cell as recited in claim 13, wherein the organic compound is a derivative of uracil.

16. The sub-fuel cell as recited in claim 4, wherein the fractal dimension of the platinum is increased to about 2.7.

17. The sub-fuel cell as recited in claim 16, wherein the fractal dimension is increased by mixing the platinum with a less active material.

18. The sub-fuel cell as recited in claim 17, wherein the less active material is carbon.

19. The sub-fuel cell as recited in claim 1, wherein the sub-fuel cell uses an 80% methanol-water mixture at 3% concentration as fuel.