Current density distributor for use in an electrode

Patent metadata

Field	Value
Publication number	US-10087537-B2
Application number	US-201414770431-A
Country	US
Kind code	B2
Filing date	Feb 26, 2014
Priority date	Feb 26, 2013
Publication date	Oct 2, 2018
Grant date	Oct 2, 2018

Abstract

The present invention relates to a mesh-shaped, porous electric current density distributor for use with an electrode, the current density distributor being adapted for providing electric current to an active layer of the electrode, which active layer is provided to contact a face of the current density distributor, wherein the current density distributor comprises a porous mesh having a plurality of electrically conductive paths, wherein at least part of the electrically conductive paths extend along a direction of major current flow over the current density distributor. The porous mesh comprises in a direction crosswise to the direction of major electric current flow, a plurality of first paths of an electric insulator. The current carrying capacity of the current density distributor in crosswise direction to the major current flow over the current density distributor is smaller than the current carrying capacity in the direction along the major current flow over the current density distributor.

First claim

The invention claimed is:

1. An electrode comprising:
at least one mesh-shaped, porous electric current density distributor having an active layer arranged to one face of the current density distributor and a hydrophobic gas diffusion layer arranged to an opposite face thereof,
wherein the active layer is provided to contact an electrolyte and
wherein the hydrophobic gas diffusion layer is porous and is provided to contact a gas,
the current density distributor being mounted into an electrically conductive frame with a lug adapted for providing electric current to the current density distributor and the active layer of the electrode, wherein the electric current flows along a direction of major current flow along the current density distributor,
wherein the current density distributor comprises a porous mesh having a plurality of electrically conductive paths,
wherein at least part of the electrically conductive paths extend along the direction of major current flow over the current density distributor,
wherein the porous mesh comprises in a direction crosswise to the direction of major current flow, at least partly of a plurality of first paths of an electric insulator, and in that a current carrying capacity of the current density distributor in the direction crosswise to the major current flow over the current density distributor is smaller than a current carrying capacity in the direction along the major current flow over the current density distributor, and
wherein the porous mesh comprises a plurality of open spaces between the electrically conductive paths and/or the first paths of the electric insulator.

2. The electrode according to claim 1 , comprising a single current density distributor.

3. The electrode according to claim 1 , wherein the active layer comprises a plurality of contact points with the current density distributor.

4. The electrode according to claim 3 , wherein the active layer comprises a catalytically active material selected from the group of one or more micro-organisms, one or more enzymes, one or more organo-metallic compounds, one or more inorganic and/or organic compounds.

5. The electrode according to claim 1 , wherein the porous mesh comprises a material selected from the group consisting of a woven wire, a knitted wire, a braided wire, a welded wire, an expanded mesh, a plate having a plurality of holes, a screen having a plurality of holes, and a plate having a plurality of holes, which has been photo-chemically etched or electroformed to provide the electrically conductive paths.

6. The electrode according to claim 1 , wherein the porous mesh has an open area of at least 50%.

7. The electrode as claimed in claim 1 , wherein the number of electrically conductive paths in the direction crosswise to the direction of major current flow per length unit is smaller than the number of electrically conductive paths per length unit along the direction of the major current flow.

8. The electrode as claimed in claim 1 , wherein the electrically conductive paths of the porous mesh comprise along the direction parallel to the current flow a plurality of first electrically conductive paths, and a plurality of second electrically conductive paths, wherein the first electrically conductive paths have a cross section which is larger in comparison to a cross section of the second electrically conductive paths.

9. The electrode according to claim 1 , wherein electrical conductivity of the electrically conductive paths at 20° C. is preferably at least 1.25×10E3 S/m.

10. The electrode according to claim 1 , wherein the resistivity of the electrically conductive paths is less than 8×10E(−4) Ohm·m.

11. The electrode according to claim 1 , wherein a material of which the electrically conductive paths are produced offers a tensile strength of at least 120 MPa.

12. The electrode according to claim 1 , wherein a material of which the electrically conductive paths are produced is selected from the group consisting of conductive polymers, metal alloys comprising one or more metals selected from the group consisting of gold, iridium, platinum, rhodium, palladium, silver, copper, nickel, zinc, tungsten, titanium, aluminum, tin, steel, stainless steel alloys, austenitic stainless steels, and duplex stainless steel.

13. The electrode according to claim 1 , wherein the electrically conductive paths have an average cross section of 50 μm to 500 μm.

14. The electrode according to claim 1 , wherein the number of electrically conductive paths in the porous mesh is between 10 and 50 paths per cm.

15. The electrode according to claim 1 , wherein the porous mesh comprises along the direction of major current flow over the current density distributor, a plurality of second paths of an electric insulator.

16. The electrode according to claim 1 ,
wherein along the direction of major current flow the electrically conductive paths and a plurality of second electrically insulating paths are alternatingly provided.

17. The electrode according to claim 1 , further comprising
a plurality of second paths of electric insulator,
wherein the electrically conductive paths and the first and second paths of electric insulator are arranged according to a regular geometric pattern.

18. The electrode according to claim 1 ,
wherein the electric conductive paths comprise a plurality of electrically conductive wires, and
wherein the first paths of an electric insulator comprise a plurality of threads of an electric insulator.

19. The electrode according to claim 1 , wherein a material for the paths of an electric insulator has an electrical resistance at 20° C. of at least 10E12 Ohm·m.

20. The electrode according to claim 1 , wherein a material for the paths of an electric insulator has a tensile strength of at least 15 MPa.

21. The electrode according to claim 1 , wherein the electric insulator offers a compression strength of at least 20 MPa.

22. The electrode according to claim 1 , wherein the plurality of first paths of electrical insulator have an average cross section of 50 μm to 250 μm.

23. The electrode according to claim 1 , wherein the number of paths of electric insulator in the porous mesh is between 10 and 50 paths per cm.

24. The electrode according to claim 1 , wherein a material for the electric insulator is selected from the group consisting of polyaramides, polyesters, polyolefins, polyetherketone, polyphenylene sulfide, polyether imide (PEI), aliphatic polyamides, fluoroplastics, and a composite material comprising a polymeric matrix of one or more of the polymers indicated above, or any combination or blend of two or more of the afore-mentioned polymers indicated above and wherein the material for the electric insulator further comprises a reinforcing component comprising glass fiber and/or ceramic fiber.

25. The electrode according to claim 24 , wherein a material for the electric insulator is polyethylene terephthalate, UHMWPE, HDPE, polypropylene, PTFE, ETFE, FEP, PFA, EFEP, or PCTFE.

26. An electrochemical cell comprising at least one electrode according to claim 1 .

27. The electrochemical cell according to claim 26 , wherein the electrochemical cell is a galvanic cell or a capacitive cell.

28. An electrochemical cell comprising a plurality of electrodes according to claim 1 , in a unipolar arrangement.

Assignees

• Vito Nv

Inventors

• Pant Deepak
• Dominguez Benetton Xochitl
• Alvarez Gallego Yolanda
• Bouwman Bert

Classifications

• H01M4/8828

  Coating with slurry or ink · CPC title

• H01M8/0243

  in the form of mixtures · CPC title

• H01G9/035

  Liquid electrolytes, e.g. impregnating materials (H01G11/54 takes precedence) · CPC title

• H01M8/08

  Fuel cells with aqueous electrolytes · CPC title

• H01M8/0232

  Metals or alloys · CPC title