JP2010123509A - Method of manufacturing membrane-electrode-gas diffusion layer assembly used in fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To facilitate the formation of an integrated structure of a catalyst layer, reinforcing film, and gas diffusion layer without positioning in manufacturing a membrane-electrode-gas diffusion layer assembly for a fuel cell. <P>SOLUTION: The membrane-electrode-gas diffusion layer assembly 20 for the fuel cell includes an electrolyte film 1, a frame-shaped reinforcing film 10 having an adhesive layer 3 with a release paper 4 on one side and reinforcing a peripheral edge part of the electrolyte film 1, and the gas diffusion layer 6 formed on the electrolyte film 1 and frame-shaped reinforcing film 10. In manufacturing the assembly 20, a rear surface of the above one side of the frame-shaped reinforcing film 10 is bonded to the electrolyte film 1, catalyst ink 5 is coated from an opening 11 of the frame-shaped reinforcing film 10 on the electrolyte film 1, the release paper 4 is peeled from the adhesive layer 3, and the gas diffusion layer 6 is adhered to the adhesive layer 3, from which the release paper 4 of the frame-shaped reinforcing film 10 is peeled, to temporarily bond. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  Membrane-Electrode-Gas Diffusion Layer (GDL) Assembly; abbreviated as “MEGA”. ] Related to the manufacturing method. More specifically, the present invention relates to a MEGA manufacturing method including a reinforcing film for reinforcing the peripheral edge of an electrolyte membrane.

As shown in FIGS. 3 (a) and 3 (b), the use for reinforcing the peripheral portion of the electrolyte membrane 1 and the electrolyte of hydrogen or air / oxygen mainly for the purpose of extending the life of the MEGA 25 used in the fuel cell. It is known that frame-shaped reinforcing films 22 and 22 are formed on the peripheral edge of the electrolyte membrane 1 for a gasket application for preventing gas intrusion into the membrane 1.
In addition, in order to maintain the power generation performance of the fuel cell, it is necessary to prevent cross leakage between the anode side and the cathode side. As one means for this, when manufacturing the MEGA 25, the electrolyte membrane 1 It is also known that the surface dimensions are made larger than the surface dimensions of the electrode catalyst layers 5 and 5 and the gas diffusion layers 6 and 6 that are sequentially formed on the electrolyte membrane 1.

Hereinafter, the configuration of the MEGA will be further described with reference to Patent Document 1 (reference numbers in this paragraph and the next paragraph are those used in Patent Document 1). According to Patent Document 1, two frame-shaped reinforcing films 22 and 22 and an electrolyte membrane 20 having an outer peripheral dimension larger than the inner peripheral dimension of these reinforcing films 22 and 22 are prepared. And it sandwiches from both surfaces so that the inner peripheral edge part of the reinforcing films 22 and 22 overlaps with the peripheral edge part of the electrolyte membrane 20, and the two frame-shaped reinforcing films 22 and 22 are bonded to each other by the adhesive film (adhesive film) 50. The MEGA 60 is manufactured by bonding.
JP 2007-250249 A

  However, in the manufacturing method of MEGA 60 of Patent Document 1, the alignment of the catalyst layer 26, the reinforcing film 22, and the GDL 28 is essential. However, the surface dimensions (outer dimensions) of the electrolyte membrane 20, the catalyst layer 26, the reinforcing film 22, and the GDL 28 are required. ) Is different. Therefore, the alignment becomes complicated, and continuous production (mass production) of MEGA 60 by roll-to-roll is difficult. In addition, since the electrolyte membrane 20, the reinforcing film 22, and the GDL 28 are thin films, they do not have rigidity (toughness), have poor handling properties as a single unit, and have been a factor of reducing manufacturing efficiency.

In the future, demand for fuel cells is increasing for various practical applications, and such a situation is undesirable.
Therefore, in view of such circumstances, the present invention eliminates the need for complicated alignment of the catalyst layer, the reinforcing film, and the GDL as in the past, and improves handling by integrating them easily, and It aims at providing the manufacturing method of MEGA suitable for the mass production line which can be produced.

(Aspect of the Invention)
Hereinafter, embodiments of the invention will be shown and described. (1) corresponds to claim 1.

(1) An electrolyte membrane, a frame-shaped reinforcing film that has an adhesive layer with release paper on one side and reinforces a peripheral portion of the electrolyte membrane, and gas diffusion formed on the electrolyte membrane and the frame-shaped reinforcing film A membrane-electrode-gas diffusion layer assembly for a fuel cell comprising a layer, the step of joining the back surface of one side of the frame-shaped reinforcing film to the electrolyte membrane by hot pressing, and a catalyst A fuel comprising a step of applying ink to the electrolyte membrane from an opening of the frame-shaped reinforcing film, a step of peeling the release paper from the adhesive layer, and a step of adhering a gas diffusion layer to the adhesive layer A method for producing a membrane-electrode-gas diffusion layer assembly for a battery.

    According to this section, a frame-like reinforcing film that has an adhesive layer with release paper on one side and reinforces the peripheral edge of the electrolyte membrane is used to manufacture a membrane-electrode-gas diffusion layer assembly (MEGA) for fuel cells. Since the position of the other components of MEGA is determined if the frame-shaped reinforcing film is joined to the electrolyte membrane because of the adoption, the conventional complicated positioning of the electrolyte membrane, the reinforcing film, the catalyst layer, and the GDL is determined. Is no longer necessary. And according to this term, an electrolyte membrane, a reinforcing film, a catalyst layer, and GDL can be easily made into an integrated structure, and handling in manufacture improves. Therefore, it becomes easy to manufacture MEGA with a mass production line capable of continuous production.

(2) The method for producing a membrane-electrode-gas diffusion layer assembly for a fuel cell according to (1), wherein the pressure-sensitive adhesive layer with release paper contains an adhesive.

  The pressure-sensitive adhesive layer with release paper included in the frame-shaped reinforcing film is a pressure-sensitive adhesive layer containing an adhesive after the release paper is peeled off, so that GDL (peripheral part) is applied with a slight pressure to the frame-shaped reinforcing film. The GDL is temporarily fixed only by placing it. Until the MEGA manufactured by the manufacturing method of the present invention is assembled to the fuel cell, the membrane-electrode-gas diffusion layer assembly is integrated by this temporary fixing, and even in the mass production line (automatic line) Make handling easy.

(3) A membrane-electrode-gas diffusion layer assembly for a fuel cell produced by the production method of (1) or (2).
(4) A fuel cell comprising the membrane-electrode-gas diffusion layer assembly according to (3). (5) The fuel cell according to (4), which is a solid molecular fuel cell or a direct methanol fuel cell.

  The items (3), (4), and (5) exemplify products obtained by using the method for producing a membrane-electrode-gas diffusion layer assembly for a fuel cell of the present invention.

(6) A frame-shaped reinforcing film for reinforcing the peripheral portion of the electrolyte membrane of the fuel cell, wherein a pressure-sensitive adhesive layer for bonding to the gas diffusion layer is formed on one surface thereof Reinforcing film.

  This section exemplifies the frame-shaped reinforcing film employed in the above manufacturing method because it can be manufactured and sold alone.

(7) The frame-shaped reinforcing film according to (6), wherein the pressure-sensitive adhesive layer contains an adhesive.

  This term illustrates the material of the adhesive layer of the frame-shaped reinforcing film of item (6).

  According to the present invention, complicated positioning of the catalyst layer, the reinforcing film, and the GDL is not required, and these can be easily integrated, so that handling is improved and suitable for a mass production line capable of continuous production. A method for manufacturing MEGA can be provided.

Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings.
FIG. 1 and FIG. 2 are examples of embodiments for carrying out the invention, and in the drawings, the same reference numerals denote the same components.

<Embodiment>
FIG. 1 is a conceptual diagram for explaining a manufacturing method of the MEGA 20 according to the present embodiment, and FIG. 2 is a manufacturing flow diagram for explaining the manufacturing method.
Hereinafter, the present embodiment will be described with reference to FIGS. 1 and 2.

  Preparatory process (FIG. 1 (1), FIG. 2 (2)): In this process, the electrolyte membrane 1 and the adhesive layer 3 with release paper 4 are provided on one side of the frame-shaped resin sheet 2, and the peripheral portion of the electrolyte membrane 1 A frame-shaped reinforcing film 10 for reinforcing the frame is prepared. As the electrolyte membrane 1, commercially available Nafion (registered trademark), Dow membrane (registered trademark), Flemion (registered trademark), Aciplex (registered trademark), or the like can be used.

  Bonding process (FIG. 1 (2), FIG. 2 (2)): In this process, the pressure-sensitive adhesive layer 3 with release paper 4 has the surface of the pressure-sensitive adhesive layer 3 with the release paper 4 opposite to the side where the electrolyte 1 is present. As shown, the electrolyte membrane 1 is hot-pressed to bond the adhesive layer 3 with release paper 4 and the electrolyte membrane 1 together. After bonding, a structure 10 having an opening 11 as shown in FIG. 1 (2) is completed.

  Catalyst ink application process (FIG. 1 (3), FIG. 2 (3)): The structure 10 has an opening 11 of the frame-shaped reinforcing film 10, and the catalyst ink 5 is applied to the electrolyte membrane 1 existing at the bottom of the opening 11. Apply. The method for applying the catalyst ink 5 may be any of a spray method, an ink jet method, an electrostatic coating method, a die coater method, and the like. The coating thickness of the catalyst ink 5 is preferably slightly larger than the film thickness of the frame-shaped resin sheet 2. This is because when the catalyst ink 5 is dried, the solvent component is evaporated, and the catalyst layer 5 is cured and contracted. When this step is completed, a structure in which the periphery of the catalyst layer 5 is surrounded by the frame-shaped resin sheet is produced.

  Release paper peeling process (FIG. 1 (4), FIG. 2 (4)): In this process, the release paper 4 of the upper layer of the frame-shaped reinforcement film 10 is peeled. However, the adhesive layer 3 is left on the frame-shaped resin sheet 2 side. The release paper 4 is discarded.

Gas diffusion layer (GDL) bonding step (FIG. 1 (5), FIG. 2 (5)): In this step, GDL 6 is bonded onto the frame-shaped adhesive layer 3. At this time, the peripheral edge of the GDL 6 is set so as to cover all the openings 11 of the frame-like adhesive layer 3, and the MEGA 20 is pressurized with a slight pressure from above to below the vertical. As a result, the GDL 6 is bonded and fixed along the inner periphery of the opening 11 of the frame-shaped adhesive layer 3. Thereby, GDL6 of MEGA20 is temporarily fixed until MEGA20 is assembled to a fuel cell. At this time, it is not necessary to precisely align the GDL6. This is because, as long as the periphery of the GDL 6 covers all the openings 11 of the frame-shaped adhesive layer 3, even if the GDL 6 is slightly displaced in the surface direction, the region where the catalyst layer 5 and the GDL 6 are in contact with each other is always This is because it becomes equal to the region of the opening 11.
Thus, according to the embodiment of the present invention, the catalyst layer 5, the frame-shaped reinforcing film 2, and the GDL 6 are laminated on the electrolyte membrane 1 in this order only on the anode electrode side or the cathode electrode side. -Electrode-gas diffusion layer assembly (MEGA) 20 is manufactured. In order to complete the MEGA 20, the MEGA 20 is completed by performing the same process on the opposite surface of the electrolyte membrane 1 where none of the layers has yet been laminated (the lower surface of the electrolyte membrane 1 in FIG. 1 (5)). be able to.

The MEGA 20 can be manufactured and sold as a single unit, but for assembly as a fuel cell, the GDL 6 on both sides of the MEGA 20 is sandwiched between separators (not shown) (
A single separator is also used as the adjacent single cell except for the separator at the end), and a plurality of single cells are stacked so that desired power can be obtained. After a plurality of single cells are stacked, a predetermined conductive plate is arranged on the anode side and cathode side end surfaces of the stack body, and several through holes, for example, four holes are formed in the conductive plate to stack. Four bolts longer than the length of the body are passed through the through holes and fastened with nuts that are screwed into the bolts, and all the single cells are pressed at a constant pressure. At this time, the gap between the catalyst layer 5 and the GDL 6 shown in FIG. Since the catalyst layer 5 is composed of a rigid three-dimensional structure made of metal-carrying conductive particles (for example, platinum-carrying carbon particles), fluff generated from carbon cloth or carbon paper as a constituent element of the GDL 6 does not pierce the electrolyte membrane 1. Similarly, the peripheral edge of the GDL 6 does not pierce the electrolyte membrane 1 with the frame-shaped resin sheet 2 in the same manner.

  It should be noted that the MEGA manufacturing method of the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the present invention.

  For example, although this embodiment demonstrated the manufacturing method of the single-piece | unit of MEGA20 shown in FIG. 1, each component, ie, the electrolyte membrane 1, the frame-shaped reinforcement film 10, and GDL6, is web shape (band | belt shape, elongate shape). To the above-mentioned bonding step, catalyst ink coating step, release paper peeling step and gas diffusion layer bonding step. Correspondingly, each device can be arranged, and a roll-to-roll mass production line can be designed and constructed (after the MEGA 20 is completed, it is cut by punching or the like as shown in parentheses before assembly of the MEGA 20 into a fuel cell) ). In this way, the mass production of MEGA is possible because the MEGA production method of the present invention has a pressure-sensitive adhesive layer 3 with release paper 4 that has never been used on one side, and the peripheral portion of the electrolyte membrane 1. When the frame-shaped reinforcing film 10 is joined to the electrolyte membrane 1 by using the frame-shaped reinforcing film 10 that reinforces, the positioning of other components, the catalyst layer, the reinforcing film, and the GDL is performed. This is because complicated positioning as in the conventional case of the reinforcing film and the GDL is not required, and these are easily integrated to improve the handling property of the MEGA being manufactured.

FIG. 1 is a conceptual diagram for explaining a method for manufacturing the MEGA 20 according to the present embodiment. FIG. 2 is a manufacturing flow diagram for explaining the manufacturing method. FIG. 3 is a schematic top view (a) and cross-sectional view (b) for explaining the structure of a conventional MEGA.

Explanation of symbols

1: electrolyte membrane, 3: adhesive layer, 4: release paper, 5: catalyst ink, 6: gas diffusion layer (GDL), 10: frame-shaped reinforcing film, 11: opening, 20: membrane-electrode-gas diffusion layer bonding Body (MEGA)

Claims (1)

An electrolyte membrane, a frame-like reinforcing film that has an adhesive layer with release paper on one side and reinforces a peripheral portion of the electrolyte membrane, a gas diffusion layer formed on the electrolyte membrane and the frame-like reinforcing film, A method for producing a membrane-electrode-gas diffusion layer assembly for a fuel cell comprising:
Bonding the back surface of the one side of the frame-shaped reinforcing film to the electrolyte membrane by hot pressing;
Applying a catalyst ink to the electrolyte membrane from the opening of the frame-shaped reinforcing film;
Peeling the release paper from the adhesive layer;
Adhering a gas diffusion layer to the adhesive layer;
For producing a membrane-electrode-gas diffusion layer assembly for a fuel cell comprising: