Substrate-enhanced microbial fuel cells

• US 20070259216A1
• Filed: 05/01/2007
• Published: 11/08/2007
• Est. Priority Date: 05/02/2006
• Status: Active Grant

• Current Assignee: Penn State Research Foundation
• Original Assignee: Penn State Research Foundation
• Inventors: Logan, Bruce
• Granted Patent: US 8,277,984 B2
• Time in Patent Office: Days
• US Class Current: 429/2
• CPC Class Codes: H01M 2004/8684 Negative electrodes
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8657 layered
• CPC Class Codes: H01M 4/9008 Organic or organo-metallic compounds
• 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

A microbial fuel cell configuration of the invention includes a substrate particularly formulated for a microbial fuel cell configured to produce electricity and/or a modified microbial fuel cell configured to produce hydrogen. A substrate formulation according to one embodiment includes a solid biodegradable organic material in a package porous to bacteria. A microbial fuel cell provided according to embodiments of the present invention includes an anode, a cathode, an electrically conductive connector connecting the anode and the cathode, a housing for an aqueous medium, the aqueous medium in contact with the anode, and a solid form of a biodegradable organic substrate disposed in the aqueous medium, the solid form of a biodegradable organic substrate formulated to support electron generation and transfer to the anode by anodophilic bacteria over a selected minimum period of time.

Claims

1. A microbial fuel cell, comprising:

a solid form of a biodegradable organic substrate, the solid form of a biodegradable organic substrate contained in a package porous to bacteria.

2. The microbial fuel cell of claim 1, wherein at least a portion of the package is electron conductive and forms at least a portion of an anode.

3. The microbial fuel cell of claim 2, wherein the package comprises a material selected from the group consisting of:

carbon paper, carbon cloth, carbon felt, carbon wool, carbon foam, graphite, porous graphite, graphite powder, graphite granules, graphite fiber, a conductive polymer, a conductive metal, and a combination of any of these.

4. The microbial fuel cell of claim 1, wherein the substrate is a biodegradable polymer.

5. The microbial fuel cell of claim 4, wherein the polymer is a polysaccharide.

6. The microbial fuel cell of claim 5 wherein the polymer is a biodegradable plastic.

7. The microbial fuel cell of claim 4 wherein the biodegradable polymer is substantially insoluble in an aqueous medium.

8. A microbial fuel cell, comprising:

an anode;

a cathode;

an electrically conductive connector connecting the anode and the cathode;

a housing for an aqueous medium, the aqueous medium in contact with at least a portion of the anode; and

a solid form of a biodegradable organic substrate disposed in the aqueous medium, the solid form of a biodegradable organic substrate formulated to support electron generation and transfer to the anode by anodophilic bacteria over a selected minimum period of time.

9. The microbial fuel cell of claim 8 wherein the solid form of a biodegradable organic substrate is characterized by a total surface area selected to support electron generation and transfer to the anode by anodophilic bacteria over a selected minimum period of time.

10. The microbial fuel cell of claim 9, wherein the biodegradable organic substrate comprises a substantially insoluble biodegradable polymer.

11. The microbial fuel cell of claim 8 wherein the biodegradable organic substrate is selected from the group consisting of:

chitin, cellulose, and a combination thereof.

12. The microbial fuel cell of claim 10 wherein the biodegradable organic substrate is a biodegradable polymer.

13. The microbial fuel cell of claim 10 wherein the aqueous medium further comprises a dissolved biodegradable organic substrate.

14. The microbial fuel cell of claim 9 wherein the solid form comprises one or more particles, each of the one or more particles having a particle surface area, wherein the total surface area is the sum of the particle surface area of the one or more particles.

15. An electrode for a microbial fuel cell, comprising:

an electrically conductive wall, the wall substantially non-toxic to anodophilic bacteria, the wall configured to form a container for a biodegradable organic substrate, at least a portion of the container porous to bacteria; and

a biodegradable organic substrate disposed in the container.

16. The electrode for a microbial fuel cell of claim 15, wherein the electrically conductive wall comprises carbon cloth.

17. The electrode for a microbial fuel cell of claim 15, wherein the electrically conductive wall comprises graphite.

18. The electrode for a microbial fuel cell of claim 15, wherein the electrically conductive wall comprises a conductive material selected from the group consisting of:

carbon wool, carbon felt, carbon paper and a combination of any of these.

19. The electrode for a microbial fuel cell of claim 15, wherein the biodegradable organic substrate is an organic material oxidizable by anodophilic bacteria or metabolizable by bacteria to produce a substrate oxidizable by anodophilic bacteria.