Membrane free fuel cell

• US 7,238,440 B2
• Filed: 09/01/2004
• Issued: 07/03/2007
• Est. Priority Date: 10/03/2003
• Status: Expired due to Fees

• Current Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Original Assignee: E. I. du Pont de Nemours and Company (Corteva, Inc.)
• Inventors: Harmer, Mark Andrew, Damore, Michael B., Farneth, William E.
• Primary Examiner(s): Yuan; Dah-Wei
• Application Number:
  US10/931,873
• Publication Number:
  US 20050106425A1
• Time in Patent Office: 1,035 Days
• Field of Search: 429/12, 429/23, 429/26
• US Class Current: 429/401
• CPC Class Codes: B82Y 30/00 Nanotechnology for materials or surface science, e.g. nanocomposites
• CPC Class Codes: H01M 2250/30 Fuel cells in portable systems, e.g. mobile phone, laptop
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8647 consisting of more than one material, e.g. consisting of composites
• CPC Class Codes: H01M 4/8673 Electrically conductive fillers
• CPC Class Codes: H01M 4/8807 Gas diffusion layers
• CPC Class Codes: H01M 4/8814 Temporary supports, e.g. decal
• CPC Class Codes: H01M 4/8828 Coating with slurry or ink
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• CPC Class Codes: H01M 8/0206 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 8/1009 with one of the reactants being liquid, solid or liquid-charged H01M8/12 takes precedence
• CPC Class Codes: H01M 8/16 Biochemical fuel cells, i.e. cells in which microorganisms function as catalysts
• CPC Class Codes: Y02B 90/10 Applications of fuel cells in buildings
• CPC Class Codes: Y02E 60/50 Fuel cells
• CPC Class Codes: Y10S 435/817 Enzyme or microbe electrode

Abstract

The invention is directed to a fuel cell comprising an anode and a cathode immersed in an electrolyte in the presence of a reductant and oxidant, wherein the distinguishing feature is that all of the elements of the fuel cell communicate freely with each other and there is no membrane or other separator between the anode and the cathode.

Claims

1. A fuel cell comprising:

(i) an anode configured and arranged for electro-oxidizing an anode reductant;

(ii) a cathode configured and arranged for electro-reducing a cathode oxidant; and

(iii) an electrolyte in solution contained within a single compartment;

wherein the anode and cathode are spaced apart and reside in the single compartment containing the electrolyte; and

wherein the electrolyte, reductant and oxidant freely communicate with the anode and the cathode;

wherein the cathode comprises a porous current collector comprising an electrical conducting material in contact with a multitude of domains, each domain containing;

a) a redox catalyst; and

b) an electron transport mediator;

wherein the redox catalyst and electron transport mediator are in fluid association with each other within the domain and wherein the redox catalyst and the electron transport mediator are bounded in the domain by the porous current collector and a containment material, and

wherein said containment material is a film comprised of materials selected from the group consisting of;

silica, titania, alumina, polyesters, polyamides, polyimides, fluoropolymers, polyelectrolytes, organosubstituted silica, silicones, organosubstituted titania and organo metal oxides.

3. A fuel cell according to either of claims 1 or 2 wherein the diameter of the domain is less than 100 μ

m.

4. A fuel cell according to either of claims 1 or 2 wherein the porous current collector comprises an electrical conducting material.

5. A fuel cell according to either of claims 1 or 2 wherein the electrical conducting material is selected from the group consisting of:

carbon paper, carbon paste, carbon nanotubes, carbon particles, conducting polymers, noble metal particles and conducting metal oxide particles.

6. A fuel cell according to either of claims 1 or 2 wherein the redox catalyst is an enzyme.

7. A fuel cell according to claim 6 wherein the enzyme is an oxido-reductase.

8. A fuel cell according to claim 1 wherein the redox catalyst is laccase.

11. A portable electronic device comprising the fuel cell of any of claims 1, 2, or 10.

12. A fuel cell according to either of claims 1, 2, or 10, wherein the redox catalyst catalyzes a redox reaction involving at least one reductant selected from the group consisting of:

hydrogen, alcohols, carbohydrates, carboxylic acids and carboxylic esters.

13. A fuel cell according to claim 12 wherein the carbohydrate is glucose.

14. A fuel cell according to claim 12, wherein said alcohol is methanol.

15. A fuel cell according to claim 12, wherein said carboxylic acid is formic acid.

16. A fuel cell according to claim 12, wherein said carboxylic ester is methyl formate.

2. A fuel cell comprising:

(i) an anode configured and arranged for electro-oxidizing an anode reductant;

(ii) a cathode configured and arranged for electro-reducing a cathode oxidant; and

(iii) an electrolyte in solution contained within a single compartment;

wherein the anode and cathode are spaced apart and reside in the single compartment containing the electrolyte; and

wherein the electrolyte, reductant and oxidant freely communicate with the anode and the cathode;

wherein the anode comprises a porous current collector comprising an electrical conducting material, in contact with a multitude of domains, each domain containing;

a) a redox catalyst; and

b) an electron transport mediator;

wherein the redox catalyst and electron transport mediator are in fluid association with each other within the domain and wherein the redox catalyst and the electron transport mediator are bounded in the domain by the porous current collector and a containment material, and wherein said containment material is a film comprised of materials selected from the group consisting of;

silica, titania, alumina, polyesters, polyamides, polyimides, fluoropolymers, polyelectrolytes, organosubstituted silica, silicones, organosubstituted titania and organo metal oxides.

9. A fuel cell according to either of claims 7 or 2 wherein the electron transport mediator is selected from the group consisting of:

quinones, hydroquinones, metalloorganic complexes, conjugated unsaturated acyclic and cyclic molecules, metal ions and biological electron carriers.

10. A fuel cell comprising:

(i) an anode configured and arranged for electro-oxidizing an anode reductant;

(ii) a cathode configured and arranged for electro-reducing a cathode oxidant; and

(iii) an electrolyte in solution contained within a single compartment;

wherein the anode and cathode are spaced apart and reside in the single compartment containing the electrolyte; and

wherein the electrolyte, reductant and oxidant freely communicate with the anode and the cathode;

wherein the anode or the cathode comprises a porous current collector comprising an electrical conducting material in contact with a multitude of domains, each domain containing;

a) a redox catalyst; and

b) an electron transport mediator;

wherein the redox catalyst and electron transport mediator are in fluid association with each other within the domain and wherein the redox catalyst and the electron transport mediator are bounded in the domain by the porous current collector and a containment material, and wherein the electron transport mediator is 2,2′

-azinobis(3-ethylbenzothiazoline-6-sulfonate).