EP-4741534-A1 - MEMBRANE ELECTRODE ASSEMBLY MANUFACTURING METHOD

EP4741534A1EP 4741534 A1EP4741534 A1EP 4741534A1EP-4741534-A1

Abstract

The present invention relates to a method of manufacturing a membrane electrode assembly, the method including the steps of: forming a first catalyst layer on the other surface of a separation membrane having a first carrier film attached to one surface(S1); attaching a second carrier film to the other surface of the separation membrane having the first catalyst layer formed(S2); removing the first carrier film attached to the one surface of the separation membrane(S3); and forming a second catalyst layer on the one surface of the separation membrane from which the first carrier film has been removed(S4), wherein the second carrier film includes a first region corresponding to the first catalyst layer among the other surface of the separation membrane, and a second region that is the remaining region excluding the first region, wherein the second region of the second carrier film has an pressure sensitive adhesive coated on a surface facing the other surface of the separation membrane on which the first catalyst layer is formed.

Inventors

YOO, JAE HYUN
KIM, KWANG HWAN
NOH, TAE GEUN
LEE, JONG JIN
JEONG, JAE HAK

Assignees

LG Chem, Ltd.

Dates

Publication Date: 20260513
Application Date: 20240828

Claims (12)

A method of manufacturing a membrane electrode assembly, the method including the steps of: forming a first catalyst layer on the other surface of a separation membrane having a first carrier film attached to one surface(S1); attaching a second carrier film to the other surface of the separation membrane having the first catalyst layer formed(S2); removing the first carrier film attached to the one surface of the separation membrane(S3); and forming a second catalyst layer on the one surface of the separation membrane from which the first carrier film has been removed(S4), wherein the second carrier film includes a first region corresponding to the first catalyst layer among the other surface of the separation membrane, and a second region that is the remaining region excluding the first region, wherein the second region of the second carrier film has a pressure sensitive adhesive coated on a surface facing the other surface of the separation membrane on which the first catalyst layer is formed.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the first region does not contain the pressure sensitive adhesive.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the second carrier film is formed of only the second region.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the first catalyst layer and the second catalyst layer in steps (S1) and (S4) are each independently formed by coating an electrode catalyst slurry on the separation membrane and then drying the electrode catalyst slurry.
The method of manufacturing a membrane electrode assembly according to claim 4, wherein the coating is performed by at least one method selected from the group consisting of a slot die method, an inkjet coating method, a spray coating method, a screen printing method, a doctor blade method, and a gravure coating method.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the thickness of the first carrier film and the second carrier film in the steps (S1) and (S2) are each independently greater than 10 µm and less than or equal to 200 µm.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the first carrier film and the second carrier film each independently include at least one selected from the group consisting of polytetrafluoroethylene, tetrafluoroethylene-hexafluoropropylene, tetrafluoroethylene-perfluoroalkyl vinyl ether, ethylene/tetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyimide, polyethylene, polypropylene, polyethylene terephthalate, and polyester.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the pressure sensitive adhesive includes at least one selected from the group consisting of an acrylic resin, a silicone resin, a rubber resin, a urethane resin, a polyester resin, and an epoxy resin.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the separation membrane is a cation exchange separation membrane or an anion exchange separation membrane.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the first catalyst layer is formed of an electrode catalyst slurry including at least one selected from the group consisting of Pt, Sn, Al, Au, Ag, C, Cd, Co, Cr, Cu, Ga, Hg, In, Mo, Nb, Ni, NiCo 2 O 4 , Ni-Fe alloy, Pb, Rh, Ti, V, W, Zn, and a mixture thereof.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the second catalyst layer is formed of an electrode catalyst slurry including at least one selected from the group consisting of Ir, Pt, Au, Pd, Ag, Rh, Ru, Ni, Al, Mo, Cr, Cu, Ti, W, and mixtures thereof.
The method of manufacturing a membrane electrode assembly according to claim 1, wherein the membrane electrode assembly is a membrane electrode assembly for water electrolysis.

Description

[Technical Field] CROSS-REFERENCE TO RELATED APPLICATION This application claims the benefit of priority to Korean Patent Application No. 10-2023-0118326 filed on September 6, 2023, the disclosure of which is incorporated herein by reference in its entirety. Technical Field The present invention relates to a method for manufacturing a membrane electrode assembly. [Background Art] Hydrogen is expected to play a very important role as a future energy storage medium. The use of infinite energy sources and pollution-free, sustainable renewable energy will highlight the problem of energy storage, and hydrogen is currently positioned as an alternative. Hydrogen is evaluated as a very valuable substance that can replace fuel without emitting harmful substances in all areas where existing fossil fuels are used. In addition, various methods are being studied for the conversion of renewable energy into hydrogen energy, and among them, one of the important methods is water electrolysis technology. The water electrolysis technology is a technology that can electrolyze water to separate it into oxygen and hydrogen, and use the hydrogen as fuel. A water electrolysis cell in which the water electrolysis technology is implemented includes a catalyst electrode in which an electrochemical reaction occurs and a polymer electrolyte membrane that transfers hydrogen ions generated by the electrochemical reaction, wherein a gas diffusion layer(GDL), a gasket, and a separation plate may be additionally disposed on both sides of the polymer electrolyte membrane, respectively. In this case, the catalyst electrode for producing hydrogen through the water electrolysis technology is composed of a hydrogen evolution reaction(HER) electrode(cathode) that generates hydrogen by reducing water, and an oxygen evolution reaction(OER) electrode(anode) that generates oxygen by oxidizing water, wherein the cathode and the anode are joined to both sides of the polymer electrolyte membrane without gaps, respectively, and this structure is called a membrane electrode assembly (MEA). The principle of water electrolysis is that water is supplied to the anode and decomposed into oxygen gas, electrons, and hydrogen ions(H+), wherein the electrons are transferred to the cathode through an external circuit, and the hydrogen ions(H+) are transferred to the cathode through the polymer electrolyte membrane. The electrons and hydrogen ions transferred to the cathode react with each other to generate hydrogen gas. Meanwhile, most of the conventional methods for manufacturing membrane electrode assemblies (MEAs) are direct coating methods, which directly coat a separation membrane with catalyst ink at once, thereby causing a problem that the swelling of the membrane occurs, and the uniformity of the thickness is reduced due to wrinkles and electrode cracks. In addition, a spray method of thinly coating several times has a problem that productivity is reduced due to considerable manufacturing time, and the loss of the precious metal catalyst is large. In addition, in order to solve the above problem, a decal transfer method was conventionally used in which an electrode was coated on a transfer film(PTFE) and decaled onto a separation membrane by a hot pressing method to manufacture a membrane electrode assembly, but this also had the problems of low productivity and high process cost. Accordingly, in order to solve the problems of the conventional membrane electrode assembly manufacturing method and to improve the processability, productivity, and quality uniformity, the present inventors have studied a method of manufacturing a membrane electrode assembly having a uniform shape without causing swelling of a separation membrane or cracks of an electrode while directly coating a catalyst ink at once. (Patent Document 1) KR 10-2023-0101340 A [Disclosure] [Technical Problem] The problem to be solved by the present invention is to provide a method for manufacturing a membrane electrode assembly that can improve processability, productivity, and quality uniformity by using a direct coating method but preventing swelling of a separation membrane and cracking of an electrode. [Technical Solution] The present invention provides a method of manufacturing a membrane electrode assembly. (1) There is provided a method of manufacturing a membrane electrode assembly, the method including the steps of: forming a first catalyst layer on the other surface of a separation membrane having a first carrier film attached to one surface(S1); attaching a second carrier film to the other surface of the separation membrane having the first catalyst layer formed(S2); removing the first carrier film attached to the one surface of the separation membrane(S3); and forming a second catalyst layer on the one surface of the separation membrane from which the first carrier film has been removed(S4), wherein the second carrier film includes a first region corresponding to the first catalyst laye