Membrane-electrode assembly for fuel cell, method for manufacturing same, and fuel cell system comprising same

Patent metadata

Field	Value
Publication number	US-10868311-B2
Application number	US-201615760287-A
Country	US
Kind code	B2
Filing date	Sep 23, 2016
Priority date	Sep 24, 2015
Publication date	Dec 15, 2020
Grant date	Dec 15, 2020

Abstract

Disclosed are a membrane-electrode assembly for fuel cells, a method of manufacturing the same and a fuel cell system containing the same. The membrane-electrode assembly for fuel cells includes an anode and a cathode facing each other, and a polymer electrolyte membrane interposed between the anode and the cathode, wherein at least one of the anode and the cathode further includes a porous support and a catalyst layer for fuel cells disposed on one surface of the porous support. The electrode of the membrane-electrode assembly is a free-standing electrode, and the electrode has excellent adhesivity to the polymer electrolyte membrane and thus can prevent performance deterioration resulting from detachment of the electrode from the polymer electrolyte membrane during operation of fuel cells, and in particular, can secure high durability since the electrode is not readily detached even under harsh operation environments.

First claim

The invention claimed is:

1. A membrane-electrode assembly for fuel cells comprising:
an anode;
a cathode; and
a polymer electrolyte membrane between the anode and the cathode,
wherein at least one of the anode and the cathode comprises a porous support and a catalyst layer, the porous support disposed between the polymer electrolyte membrane and the catalyst layer,
wherein the at least one of the anode and the cathode includes catalyst particles and a binder resin,
wherein a portion of the catalyst particles and a portion of the binder resin are included in the catalyst layer,
wherein the rest of the catalyst particles are disposed only in a first region of the porous support and the rest of the binder resin is disposed across an entire region of the porous support, such that there is a second region of the porous support where the binder resin exists but the catalyst particles do not exist, and
wherein the second region is disposed between the first region and the polymer electrolyte membrane.

2. The membrane-electrode assembly according to claim 1 , wherein a ratio of a total thickness of the catalyst layer and the first region to a thickness of the second region is 1:1 to 10:1.

3. The membrane-electrode assembly according to claim 1 , wherein a content of the binder resin in the catalyst layer or the first region is 20 to 40% by weight with respect to the total weight of the catalyst layer or the first region.

4. The membrane-electrode assembly according to claim 1 , wherein a mean size of pores of the porous support is 300 nm to 100 nm,
a mean particle diameter of the catalyst particles is 450 nm to 250 nm, and
a mean particle diameter of the binder resin is 250 nm to 50 nm.

5. The membrane-electrode assembly according to claim 1 , wherein the porous support comprises an expanded polytetrafluoroethylene (e-PTFE) polymer.

6. The membrane-electrode assembly according to claim 1 , wherein the porous support comprises a nanoweb in which nanofibers are integrated in form of a non-woven fabric including a plurality of pores.

7. The membrane-electrode assembly according to claim 6 , wherein the nanofibers comprise any one selected from the group consisting of nylon, polyimide, polyaramid, polyetherimide, polyacrylonitrile, polyaniline, poly(ethylene oxide), polyethylene naphthalate, poly(butylene terephthalate), styrene butadiene rubber, polystyrene, polyvinyl chloride, polyvinyl alcohol, polyvinylidene fluoride, polyvinyl butylene, polyurethane, polybenzoxazole, polybenzimidazole, polyamide-imide, polyethylene terephthalate, polyethylene, polypropylene, a copolymer thereof, and a mixture thereof.

8. The membrane-electrode assembly according to claim 6 , wherein the nanoweb is manufactured by electrospinning.

9. A method of manufacturing a membrane-electrode assembly for fuel cells comprising:
preparing a composition including catalyst particles and a binder resin;
applying the composition onto a porous support such that (i) a portion of the catalyst particles and a portion of the binder resin remains on the porous support, (ii) the rest of the catalyst particles permeate only to a partial depth of the porous support, and (iii) the rest of the binder resin permeate permeates to an entire depth of the porous support;
in order to form an electrode sheet, drying the composition-applied porous support such that (i) a catalyst layer including the portion of the catalyst particles and the portion of the binder resin is formed on the porous support, (ii) the rest of the catalyst particles are disposed only in a first region of the porous support, the first region being in contact with the catalyst layer, and (iii) there is a second region of the porous support where the binder resin exists but the catalyst particles do not exist; and
bonding the electrode sheet to a polymer electrolyte membrane in such a way that the second region is disposed between the first region and the polymer electrolyte membrane.

10. A fuel cell system comprising:
a fuel supply for supplying a fuel mixture of fuel and water;
a modifier for modifying the fuel mixture to generate a modification gas including hydrogen gas;
a stack comprising the membrane-electrode assembly according to claim 1 and generating electric energy by electrochemical reaction between the modification gas including hydrogen gas supplied from the modifier with an oxidant; and
an oxidant supply for supplying the oxidant to the modifier and the stack.

Assignees

• Kolon Inc

Inventors

• Cho Dong Jun

Classifications

• H01M4/8668

  Binders · CPC title

• H01M8/0239

  Organic resins; Organic polymers · CPC title

• H01M4/8657 Primary

  layered · CPC title

• H01M4/8846

  Impregnation · CPC title

• H01M4/8663

  Selection of inactive substances as ingredients for catalytic active masses, e.g. binders, fillers · CPC title