MICROBIAL FUEL CELL

• US 20110236725A1
• Filed: 03/27/2009
• Published: 09/29/2011
• Est. Priority Date: 03/28/2008
• Status: Active Grant

• Current Assignee: Japan Science And Technology Agency, University of Tokyo
• Original Assignee: Japan Science And Technology Agency, University of Tokyo
• Inventors: Kato, Soichiro, Nakamura, Ryuhei, Kai, Fumiyoshi, Watanabe, Kazuya, Hashimoto, Kazuhito
• Granted Patent: US 8,852,765 B2
• Time in Patent Office: Days
• US Class Current: 429/2
• CPC Class Codes: C12N 1/20 Bacteria; Culture media therefor
• CPC Class Codes: C12P 1/04 by using bacteria
• CPC Class Codes: C12P 3/00 Preparation of elements or inorganic compounds except carbon dioxide recovery of carbon dioxides as by-products C12F3/02
• CPC Class Codes: H01M 4/8605 Porous electrodes
• CPC Class Codes: H01M 4/8673 Electrically conductive fillers
• CPC Class Codes: H01M 4/90 Selection of catalytic material
• 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

It is an object of the present invention to provide a microbial fuel cell capable of increasing a current density without employing a mediator. The microbial fuel cell 1 includes a 3-dimensionally structured agglomerate formed from conductive fine particles 2 and microorganisms 3. In the agglomerate 4, the conductive fine particles 2 disperse among pieces of Shewanella 3 and the conductive fine particles 2 are coupled to one another to hold Shewanella 3, thus forming the 3-dimensional structure as a whole. Accordingly, with respect to Shewanella 3, conductive fine particles 2 hold Shewanella 3a on a surface of an electrode 103 and even Shewanella 3b positioned vertically away from the surface of the electrode 103. Hence, it becomes possible that more pieces of Shewanella 3 are allowed to transfer electrons.

Claims

1. A microbial fuel cell equipped with a pair of electrodes and an external circuit electrically connecting a pair of said electrodes, wherein on a negative electrode that is one of said electrodes, 3-dimensionally structured agglomerates are formed in a solution containing conductive fine particles and microorganisms with an extracellular electron transfer capability and then said conductive fine particles transfer electrons from said microorganisms to said negative electrode.

2. The microbial fuel cell according to claim 1, wherein said conductive fine particles disperse among said microorganisms and further said conductive fine particles are coupled to one another to hold said microorganisms.

3. The microbial fuel cell according to claim 1, wherein said conductive fine particles include ferric oxide.

4. The microbial fuel cell according to claim 3, wherein said conductive fine particles include α

-Fe₂O₃, α

-FeOOH, γ

-Fe₂O₃, ε

-Fe₂O₃ or Fe₃O₄.

5. The microbial fuel cell according to claim 1, wherein said conductive fine particles include ferric sulfide.

6. The microbial fuel cell according to claim 5, wherein said conductive fine particles are obtained by biosynthesis of microorganisms in an environment where ferric ions and sulfide ions coexist.

7. The microbial fuel cell according to claim 1, wherein said conductive fine particles include manganese oxide.

8. The microbial fuel cell according to claim 1, wherein said microorganisms are metal-reducing bacteria.

9. The microbial fuel cell according to claim 8, wherein said metal-reducing bacteria include bacteria of a Shewanella group, a Geobacter group, a Rhodoferax group or a Pseudomonas group.

10. The microbial fuel cell according to claim 8, wherein said metal-reducing bacteria contain Shewanella loihica or Shewanella oneidensis.