Biocatalytic direct alcohol fuel cell

• US 20040048111A1
• Filed: 06/18/2003
• Published: 03/11/2004
• Est. Priority Date: 06/28/2002
• Status: Active Grant

• Current Assignee: Enfucell Oy
• Original Assignee: Enfucell Oy
• Inventors: Korhola, Matti, Zhang, Xia-Chang, Halme, Aarne, Suomela, Jussi, Ranta, Anja
• Granted Patent: US 7,384,701 B2
• Time in Patent Office: Days
• US Class Current: 429/2
• CPC Class Codes: H01M 8/1004 characterised by membrane-electrode assemblies [MEA] H01M8/12 takes precedence
• 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: Y02E 60/50 Fuel cells

Abstract

The invention relates to a biocatalytic direct alcohol fuel cell comprising an anode chamber, one or more cathode chambers, and an ion exchange membrane between the chambers. The anode chamber contains a biocatalyst for oxidation of the fuel, and the cathode chamber contains a chemical catalyst, a biocatalyst or a combination thereof for reduction of oxygen or a corresponding oxidant.

Claims

1. A biocatalytic direct alcohol fuel cell comprising an anode chamber, one or more cathode chambers, and an ion exchange membrane between the chambers, wherein the anode chamber contains a biocatalyst for oxidation of the fuel, and the cathode chamber contains a chemical catalyst, a biocatalyst or a combination thereof for reduction of oxygen or a corresponding oxidant.

2. A fuel cell as claimed in claim 1, wherein the fuel cell comprises two cathode chambers.

3. A fuel cell as claimed in claim 1, wherein the biocatalyst contained by the anode chamber is an enzyme operating without a NADH cofactor.

4. A fuel cell as claimed in claim 3, wherein the enzyme is an alcohol dehydrogenase of a PQQ type.

5. A fuel cell as claimed in claim 1, wherein the anode chamber contains fuel, a buffering agent and a current collector electrode, enzyme, mediator, stabilizer and electron conductor.

6. A fuel cell as claimed in claim 5, wherein the alcohol fuel is a lower alcohol or an aqueous solution thereof, preferably methanol.

7. A fuel cell as claimed in claim 5, wherein the mediator is N,N,N′

,N′

tetramethyl phenylene diamine or a compound having corresponding characteristics.

8. A fuel cell as claimed in claim 5, wherein the stabilizer is a metal oxide or a metal salt, preferably TiO₂.

9. A fuel cell as claimed in claim 5, wherein the current collector electrode is a nickel or steel net or a graphite membrane.

10. A fuel cell as claimed in claim 5, wherein the electron conductor is a graphite coating containing fine-grained graphite powder and a binder, such as paraffin oil or gelatin.

11. A fuel cell as claimed in claim 5, wherein the biocatalyst is free in the fuel solution or the biocatalyst is mechanically entrapped onto the surface of the current collector electrode with a dialysis membrane, and the mediator and the stabilizer are attached to the surface of the current collector electrode by means of a graphite coating, or the biocatalyst, the mediator and the stabilizer are fixed onto the surface of the current collector electrode by means of a graphite coating, or the biocatalyst, the mediator and the stabilizer and fixed onto the surface of an ion exchange membrane by means of a graphite coating.

12. A fuel cell as claimed in claim 11, wherein the biocatalyst is mechanically entrapped onto the surface with a dialysis membrane, and the mediator and the stabilizer are fixed onto the surface of the current collector electrode by means of a graphite coating, or the biocatalyst, the mediator and the stabilizer are fixed onto the surface of the current collector electrode by means of a graphite coating.

13. A fuel cell as claimed in claim 1, wherein the cathode chamber contains a chemical wet cathode, wherein the chemical catalyst, such as silver, is fixed onto the surface of the current donor electrode by means of a conductive material, such as a graphite coating, and a liquid electrolyte, and the oxygen flows into the cathode chamber from atmospheric air through an oxygen-permeable membrane.

14. A fuel cell as claimed in claim 1, wherein the cathode chamber contains a solid electrolyte and a chemical dry cathode, whereby the chemical catalyst, the dry cathode and the current donor electrode are fixed together onto the surface of the ion exchange membrane such that the entity is in direct contact with air.

15. A fuel cell as claimed in claim 1, wherein the oxygen required in the cathode reaction is a chemical, such as hydrogen peroxide, instead of atmospheric oxygen, the chemical being stored in a separate closed reservoir attached to the cathode chamber, the reservoir being in communication with the cathode chamber through an oxygen-permeable membrane.

16. A method of producing electrical power with a device as claimed in any one of the preceding claims, comprising:

oxidizing fuel in an anode chamber by using a biocatalyst,

conveying the generated electrons to a current collector electrode by means of a mediator,

reducing oxygen or a corresponding oxidant in a cathode chamber by means of electrons originating from a current donor electrode and a chemical catalyst, a biocatalyst or a combination thereof.

17. A method of monitoring the state of a fuel cell as claimed in any one of claims 1 to 15, comprising:

monitoring the color change of a liquid comprised by an anode chamber visually through one or more transparent walls of the anode chamber.

18. Use of a fuel cell as claimed in any one of claims 1 to 15 for producing electrical power.