Method of manufacturing planar membrane electrode assembly for fuel cell and planar membrane electrode assembly for fuel cell manufactured using the same

Patent metadata

Field	Value
Publication number	US-2020036025-A1
Application number	US-201816206712-A
Country	US
Kind code	A1
Filing date	Nov 30, 2018
Priority date	Jul 30, 2018
Publication date	Jan 30, 2020
Grant date	—

Abstract

Disclosed are a method of manufacturing a membrane electrode assembly for a fuel cell and a membrane electrode assembly for a fuel cell manufactured using the same. The planar membrane electrode assembly for a fuel cell may include an ionomer membrane formed on both side surfaces of an electrode and between the electrode and an electrolyte membrane, thereby increasing interfacial bonding force between the electrode and the electrolyte membrane and improving the durability of a cell. In addition, the membrane electrode assembly may include planar or smooth surfaces such that formation of voids or surface steps between the electrode and a sub-gasket may be prevented, thereby improving airtightness and preventing deterioration attributable to concentration of pressure.

First claim

What is claimed is:

1 . A method of manufacturing a membrane electrode assembly for a fuel cell, comprising:
forming a plurality of electrodes on a substrate so as to be spaced apart from each other at a predetermined interval; preparing one or more electrode composites, each of the electrode composites comprising an ionomer membrane formed on the substrate and the plurality of electrodes so as to fill a space between the electrodes and to cover the electrodes; stacking and bonding the one or more electrode composites onto a first surface and a second surface of an electrolyte membrane so that the electrolyte membrane and the ionomer membrane of the each of the electrode composites contact each other; preparing a membrane electrode assembly by removing the substrate; and bonding a sub-gasket to the first and second surfaces of the membrane electrode assembly so as to cover edges of the electrodes and the ionomer membrane.

2 . A method of manufacturing a membrane electrode assembly for a fuel cell, comprising:
forming a plurality of electrodes on a substrate so as to be spaced apart from each other at a predetermined interval; preparing a first electrode composite and a second electrode composite, each comprising an ionomer membrane formed on the substrate and the plurality of electrodes so as to fill a space between the electrodes and to cover the electrodes; bonding a first surface of an electrolyte membrane to the first electrode composite so that the ionomer membrane of the first electrode composite and the first surface of the electrolyte membrane contact each other; stacking and bonding the second electrode composite onto a second surface of the electrolyte membrane so that the ionomer membrane of the second electrode composite and the second surface of the electrolyte membrane contact each other; preparing a membrane electrode assembly by removing the substrate; and bonding a sub-gasket to each of the first and second surfaces of the membrane electrode assembly so as to cover edges of the electrodes and the ionomer membrane.

3 . The method of claim 1 , wherein the substrate comprises one or more selected from the group consisting of polyethylene terephthalate, polyethylene naphthalate, and polyimide.

4 . The method of claim 1 , wherein the one or more electrode composites are bonded to the electrolyte membrane by performing thermocompression bonding using a roll press machine heated to a temperature of about 80 to 120° C.

5 . The method of claim 2 , wherein the second electrode composite is bonded to the second surface of the electrolyte membrane by performing thermocompression bonding using a roll press machine heated to a temperature of about 80 to 120° C.

6 . The method of claim 1 , wherein the plurality of the electrodes of the membrane electrode assembly comprise an anode and a cathode that are disposed on the different electrode composites such that the electrolyte membrane is interposed between the anode and the cathode, and
wherein the anode has a thickness of about 1 to 5 μm, and the cathode has a thickness of about 5 to 15 μm.

7 . The method of claim 1 , wherein the ionomer membrane is formed by applying an ionomer solution onto the substrate, and
wherein the ionomer solution has a solid content of about 10 to 50% by weight and a viscosity of about 10 to 50 cP at a temperature of about 25° C.

8 . The method of claim 7 , wherein the ionomer solution comprises a perfluorinated sulfonic acid polymer and an organic solvent.

9 . The method of claim 1 , wherein the ionomer membrane is formed by applying an ionomer solution onto the substrate, drying the ionomer solution at a temperature of about 80° C. for about 5 to 30 minutes, and thermally treating the ionomer solution at a temperature of about 160° C. for about 5 to 30 minutes.

10 . The method of claim 6 , wherein the ionomer membrane formed on the plurality of the electrodes has a thickness greater than a thickness of each of the plurality of the electrodes.

11 . The method of claim 10 , wherein the ionomer membrane formed on the anode has a thickness of about 2 to 8 μm, and the ionomer membrane formed on the cathode has a thickness of about 6 to 18 μm.

12 . The method of claim 1 , wherein the electrolyte membrane comprises a reinforcing layer and an ionomer impregnated in the reinforcing layer.

13 . The method of claim 2 , wherein the electrolyte membrane is a reinforcing layer.

14 . The method of claim 12 , wherein the reinforcing layer comprises expanded polytetrafluoroethylene (e-PTFE).

15 . The method of claim 1 , wherein after the substrate is removed, each of both surfaces of the membrane electrode assembly has a planar-shaped structure by embedding the plurality of the electrodes and filling the space between the plurality of the electrodes with the ionomer membrane.

16 . A membrane electrode assembly for a fuel cell comprising:
an anode composite comprising an anode, a first ionomer membrane interposed between the anode and an electrolyte membrane and having a greater surface area than a surface area of the anode, and a second ionomer membrane located in a same layer as the anode and filling a space formed by the anode and the first ionomer membrane; a cathode composite comprising a cathode, a third ionomer membrane interposed between the cathode and the electrolyte membrane and having a greater surface area than a surface area of the cathode, and a fourth ionomer membrane located in a same layer as the cathode and filling a space formed by the cathode and the third ionomer membrane, wherein the electrolyte membrane is interposed between the anode composite and the cathode composite; and a gasket bonded to an edge of the anode, the second ionomer membrane, an edge of the cathode, and the fourth ionomer membrane.

17 . The membrane electrode assembly of claim 16 , wherein the electrolyte membrane comprises a reinforcing layer which is optionally impregnated with an ionomer.

18 . The membrane electrode assembly of claim 16 , wherein the reinforcing layer has a thickness of 1 to 5 μm.

19 . The membrane electrode assembly of claim 16 , wherein the anode has a thickness of about 1 to 5 μm, and the cathode has a thickness of about 5 to 15 μm.

20 . The membrane electrode assembly of claim 16 , wherein each of the first ionomer membrane and the third ionomer membrane has a thickness of about 1 to 3 μm.

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Kim Min Jin
• Lee Woo Jin
• Kim Yong Min

Classifications

• H01M8/1004 Primary

  characterised by membrane-electrode assemblies [MEA] (H01M8/12 takes precedence) · CPC title

• H01M4/8878

  Treatment steps after deposition of the catalytic active composition or after shaping of the electrode being free-standing body · CPC title

• H01M4/8875 Primary

  Methods for shaping the electrode into free-standing bodies, like sheets, films or grids, e.g. moulding, hot-pressing, casting without support, extrusion without support · CPC title

• H01M2250/20

  Fuel cells in motive systems, e.g. vehicle, ship, plane · CPC title

• H01M8/0286

  Processes for forming seals · CPC title