JP2012234713A - Method for joining electrolyte membrane and film, and method for manufacturing fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a technique for bonding a reinforcing film to an electrolyte membrane having a catalyst electrode layer.SOLUTION: A method for joining an electrolyte membrane having a catalyst electrode layer and a first film for reinforcing the electrolyte membrane comprises: a preparation step of preparing a laminate film in which the first film and a second film are laminated and the electrolyte membrane having the catalyst electrode layer; a cutting step of providing a cut in a boundary between an inner region set in the first film of the laminate film and an outer region formed in an outer periphery of the inner region; a compression step of thermally compressing the laminate film and the electrolyte membrane when the inner region for which the cut is provided in the boundary with the outer region is in contact with the catalyst electrode layer; and a peeling step of peeling the inner region of the first film from the thermally compressed laminate film and a laminate of the electrolyte membrane together with the second film.

Description

  The present invention relates to a method for joining an electrolyte membrane having a catalyst electrode layer and a film for reinforcing the electrolyte membrane, and a method for manufacturing a fuel cell.

  Conventionally, in an electrolyte membrane provided with a catalyst electrode layer, in order to suppress a decrease in strength due to thinning and a decrease in handling properties, a technique of attaching a frame-shaped reinforcing film to a region where the catalyst electrode layer of the electrolyte membrane is not formed It has been known. However, since the reinforcing film is very thin, when a reinforcing film that has been cut into a frame shape in advance is attached to the electrolyte membrane, alignment with the catalyst electrode layer formed on the electrolyte membrane is not easy. Further, the frame-shaped reinforcing film is not easy to handle because it cannot be rolled. On the other hand, when the sheet-like reinforcing film is attached to the electrolyte membrane and then cut into a frame shape, the electrolyte membrane may be damaged during the cutting.

  In order to solve this problem, a half-cut reinforcing film is attached to the electrolyte membrane so that the half-cut surface is in contact with the electrolyte membrane. A technique for attaching a frame-shaped reinforcing film to an electrolyte membrane by cutting is known. (Patent Document 1).

JP 2010-027227 A JP 2010-120293 A JP 2008-149642 A

  However, since the conventional technique performs, for example, a half cut on the reinforcing film attached to the electrolyte membrane, there is still a possibility that the electrolyte membrane is damaged during the half cut. Thus, there is still room for improvement with respect to the technique for attaching the reinforcing film to the electrolyte membrane.

  The present invention has been made to solve the above-described problems, and an object thereof is to facilitate the technique of attaching a reinforcing film to an electrolyte membrane including a catalyst electrode layer.

  In order to solve at least a part of the above problems, the present invention can be realized as the following aspects or application examples.

[Application Example 1]
A method of joining an electrolyte membrane comprising a catalyst electrode layer and a first film for reinforcing the electrolyte membrane,
A preparation step of preparing a laminated film obtained by laminating the first film, a second film different from the first film, and an electrolyte membrane including the catalyst electrode layer;
A cutting step of providing a cut at the boundary between the inner region set in the first film of the laminated film and the outer region formed in the outer peripheral portion of the inner region;
A crimping step of thermocompression bonding the laminated film and the electrolyte membrane in a state where the inner electrode region where the cut is provided at the boundary with the outer region and the catalyst electrode layer are in contact with each other;
And a peeling step of peeling the inner region of the first film together with the second film from the laminated body of the laminated film and the electrolyte membrane which are thermocompression bonded.

  According to this configuration, after the laminated film and the electrolyte membrane are thermocompression bonded, the reinforcing film is easily attached to the electrolyte membrane including the catalyst electrode layer in order to peel the inner region of the first film together with the second film. be able to.

[Application Example 2]
In the joining method described in Application Example 1,
The preparation step includes a step of preparing an electrolyte membrane in which a catalyst electrode layer is formed in a partial region of the main surface,
The cutting step includes a step of cutting the first film with the shape of the catalyst electrode layer formed on the electrolyte membrane as the shape of the inner region,
In the peeling step, in the state where the outer region of the frame-shaped first film is left in a region where the catalyst electrode layer is not formed in the electrolyte membrane, the first film is formed together with the second film. A bonding method including a step of peeling the inner region.

  According to this configuration, after the laminated film and the electrolyte membrane are thermocompression bonded, the first film and the second film are left together with the inner region of the first film remaining in the region where the catalyst electrode layer of the electrolyte membrane is not formed. In order to peel the outer area | region of 1 film, a frame-shaped reinforcement film can be easily affixed on the electrolyte membrane provided with a catalyst electrode layer.

[Application Example 3]
In the joining method described in Application Example 1 or Application Example 2,
The electrolyte membrane provided with the catalyst electrode layer prepared in the preparation step is thermocompression bonded to the surface of the catalyst electrode layer with a test electrolyte membrane different from the electrolyte membrane, and is 180 ° with respect to the test electrolyte membrane. The test force when the peel test is performed is 5 N / m or less,
In the pressure bonding step, the thermocompression bonding between the laminated film and the electrolyte membrane is a bonding method in which a pressure bonding temperature is 150 ° C. or less, a pressure bonding pressure is 2 MPa or less, and a pressure bonding time is greater than 0 minutes and 20 minutes or less.

  According to this structure, a part of 1st film can be easily peeled with a 2nd film.

[Application Example 4]
In the joining method according to any one of Application Example 1 to Application Example 3,
The first film is formed of polyethylene naphthalate,
The joining method, wherein the second film is formed of polyethylene terephthalate.

  According to this configuration, by reinforcing the electrolyte membrane with the first film, it is possible to suppress a decrease in the strength and handling of the electrolyte membrane.

[Application Example 5]
A fuel cell manufacturing method comprising:
Preparing the electrolyte membrane to which the first film is bonded by the bonding method according to any one of Application Example 1 to Application Example 4,
Disposing gas diffusion layers on both sides of the electrolyte membrane to which the first film is bonded;
And a step of arranging a pair of separators on both sides of the laminate of the gas diffusion layer and the electrolyte membrane.

  According to this configuration, a fuel cell including an electrolyte membrane with a reinforcing film attached thereto can be easily manufactured.

  In addition, this invention can be implement | achieved in various aspects, For example, the joining method of a membrane electrode assembly and a reinforcement film, and the joining method of a membrane electrode assembly and a reinforcement film are made into a part of process. The present invention can be realized in the form of a manufacturing method for a fuel cell, a manufacturing method for a laminated body used in a fuel cell, a manufacturing apparatus, and a control program for causing the apparatus to execute these methods.

It is a flowchart which shows the flow of the joining method of the electrolyte membrane with a catalyst layer in 1st Example, and a reinforcement film. It is explanatory drawing for demonstrating schematic structure of the electrolyte membrane with a catalyst layer, and a 2 layer film. It is explanatory drawing for demonstrating the state which half-cut the two-layer film. It is explanatory drawing for demonstrating the state which joined the electrolyte membrane with a catalyst layer, and a 2 layer film. It is explanatory drawing which illustrated the state which peeled the conveyance film from the laminated body. It is explanatory drawing for demonstrating the joining method of the electrolyte membrane with a catalyst layer and reinforcement film in a prior art example. It is explanatory drawing for demonstrating the joining method of the electrolyte membrane with a catalyst layer and reinforcement film in 2nd Example. It is explanatory drawing for demonstrating the half cut state of the two-layer film in a modification.

A. First embodiment:
FIG. 1 is a flowchart showing the flow of a method for joining an electrolyte membrane with a catalyst layer and a reinforcing film in the first embodiment. In joining the electrolyte membrane with catalyst layer and the reinforcing film, first, an electrolyte membrane with catalyst layer to be joined and a two-layer film partially including the reinforcing film are prepared (step S110).

  FIG. 2 is an explanatory diagram for explaining a schematic configuration of an electrolyte membrane with a catalyst layer and a two-layer film. FIG. 2A is an explanatory view illustrating a state in which the electrolyte membrane with a catalyst layer 200 and the two-layer film 300 are viewed obliquely, and the electrolyte membrane with a catalyst layer 200 is shown translucently. FIG. 2B is an explanatory view illustrating a state in which the electrolyte membrane with catalyst layer 200 and the two-layer film 300 are viewed from the side. The electrolyte membrane with catalyst layer 200 includes an electrolyte membrane 210 and a catalyst electrode layer 220.

  The electrolyte membrane 210 is a polymer electrolyte membrane (for example, Nafion (registered trademark) membrane: NRE212) formed of a fluorine-based sulfonic acid polymer as a solid polymer material, and has good proton conductivity in a wet state. The electrolyte membrane 210 is not limited to Nafion (registered trademark), and other fluorine-based sulfonic acid membranes such as Aciplex (registered trademark) and Flemion (registered trademark) may be used, for example. Further, as the electrolyte membrane 210, a fluorine-based phosphonic acid film, a fluorine-based carboxylic acid film, a fluorine-hydrocarbon-based graft film, a hydrocarbon-based graft film, an aromatic film, or the like may be used. The electrolyte membrane 210 of the present example has a rectangular shape.

  The catalyst electrode layer 220 is formed in a partial region of one main surface (the lower side in FIG. 2) of the electrolyte membrane 210 and has a rectangular shape smaller than the electrolyte membrane 210. Therefore, the electrolyte membrane 210 has a frame-shaped outer peripheral region 210f in which the catalytic electrode layer 220 is not disposed on the outer peripheral portion of the catalytic electrode layer 220 on the main surface (the lower side in FIG. 2) on which the catalytic electrode layer 220 is formed. Have.

  The catalyst electrode layer 220 functions as an anode electrode or a cathode electrode when used in a fuel cell. The catalyst electrode layer 220 includes, for example, carbon particles (catalyst support carrier) supporting a catalyst metal (for example, platinum) that progresses an electrochemical reaction, and a polymer electrolyte (for example, a fluorine resin) having proton conductivity. It is configured. As the conductive carrier, in addition to carbon particles, for example, carbon materials such as carbon black, carbon nanotubes, carbon nanofibers, carbon compounds represented by silicon carbide, and the like can be used. In addition to platinum, for example, platinum alloy, palladium, rhodium, gold, silver, osmium, iridium and the like can be used as the catalyst metal.

  The electrolyte membrane 200 with a catalyst layer of this example has a test force of 5 N / m or less when a 180 ° peel test is performed by thermocompression bonding a separate electrolyte membrane different from the electrolyte membrane 210 to the surface of the catalyst electrode layer 220. It is formed using a catalyst layer forming method (for example, spin coating method). This is for adjusting the adhesive force between the catalyst electrode layer 220 and the reinforcing film 310 when a two-layer film is joined to the electrolyte membrane with a catalyst layer 200, as will be described later. If the electrolyte membrane 200 with a catalyst layer of the present embodiment is a production method capable of obtaining the test force described above, a catalyst layer sheet produced by applying and drying a catalyst ink on a substrate is pressure-bonded to the surface of the electrolyte membrane 210. The method is not limited, and a method of directly applying the catalyst ink to the electrolyte membrane 210 may be used.

  The two-layer film 300 includes a reinforcing film 310 and a transport film 320. The reinforcing film 310 is preferably made of a sheet having acid resistance and heat resistance in a high temperature environment higher than the glass transition point of the electrolyte membrane 210. In this embodiment, the reinforcing film 310 is made of PEN (polyethylene naphthalate). The material of the reinforcing film 310 may be a polyester polymer compound other than PEN (polyethylene naphthalate) such as PET (polyethylene terephthalate), polystyrene, polyvinyl chloride (hard), polyamide, polyimide, polycarbonate. It may be polyurethane, thermosetting glass-filled silicone, or the like.

  As the transport film 320, a slightly adhesive sheet or the like based on PET (polyethylene terephthalate) can be used. As a material of the transport film 320, a material similar to the reinforcing film 310 described above can be used other than PET (polyethylene terephthalate). The reinforcing film 310 and the transport film 320 may be the same material or different materials. In the two-layer film 300, the reinforcing film 310 and the transport film 320 are joined with a predetermined adhesive force by the fine adhesion provided in the transport film 320. In addition, the reinforcing film 310 of a present Example corresponds to the "1st film" in a claim. Further, the transport film 320 corresponds to a “second film” in the claims. Next, the prepared two-layer film 300 is half-cut (step S120).

  FIG. 3 is an explanatory diagram for explaining a state in which a two-layer film is half-cut. FIG. 3A is an explanatory view illustrating a state in which the electrolyte membrane with catalyst layer 200 and the half-cut two-layer film 300 are viewed from an oblique direction, and the electrolyte membrane with catalyst layer 200 is shown translucently. FIG. 3B is an explanatory view illustrating a state in which the electrolyte membrane 200 with a catalyst layer and the half-cut two-layer film 300 are viewed from the side.

  The half-cut of the two-layer film 300 is performed by making a cut (cut) so as to divide the reinforcing film 310 into two regions without making a cut (cut) in the transport film 320. The reinforcing film 310 is provided with a cut at the boundary between the rectangular inner region 310p located near the center and the frame-shaped outer region 310f located on the outer periphery of the inner region 310p. Thereby, the inner region 310p and the outer region 310f of the reinforcing film 310 are divided. The shape of the inner region 310p is the same as the shape of the catalyst electrode layer 220 formed in the electrolyte membrane with catalyst layer 200. Therefore, as described later, when the electrolyte membrane with catalyst layer 200 and the two-layer film 300 are laminated, the inner region 310p is in contact with the catalyst electrode layer 220 so that the outer periphery coincides. The cutting of the reinforcing film 310 can be performed using, for example, a Thomson blade, a rotary die cutter, or the like. After half-cutting the two-layer film 300, the catalyst layer-attached electrolyte membrane 200 and the two-layer film 300 are joined by thermocompression bonding (step S130).

  FIG. 4 is an explanatory diagram for explaining a state in which the electrolyte membrane with a catalyst layer and the two-layer film are joined. FIG. 4A is an explanatory view illustrating a state in which the laminated body 100 of the electrolyte membrane with a catalyst layer 200 and the two-layer film 300 is viewed from an oblique direction, and the electrolyte membrane with the catalyst layer 200 is shown translucently. . FIG. 4B is an explanatory view illustrating a state in which the stacked body 100 is viewed from the side.

  In the laminate 100, the main surface (the lower side in FIG. 3) on which the electrolyte membrane 210 of the electrolyte membrane 200 with a catalyst layer is formed contacts the reinforcing film 310 side (the upper side in FIG. 3) of the two-layer film 300. Thus, the electrolyte membrane with catalyst layer 200 and the two-layer film 300 are laminated. At this time, in the electrolyte membrane with catalyst layer 200 and the two-layer film 300, the position of the catalyst electrode layer 220 of the electrolyte membrane with catalyst layer 200 and the position of the inner region 310p of the reinforcing film 310 coincide, and the outer peripheral region of the electrolyte membrane 210 The position of 210f and the position of the outer region 310f of the reinforcing film 310 are in contact with each other.

  The thermocompression bonding of the electrolyte membrane with catalyst layer 200 and the two-layer film 300 is performed by heating the laminated body 100 while applying pressure from the laminating direction using a thermocompression bonding apparatus (not shown). As the thermocompression bonding apparatus, for example, a hot press plane press, a hot press roll press, or the like can be used. As processing conditions for the thermocompression treatment, the adhesive force FA1 between the inner region 310p of the reinforcing film 310 and the catalyst electrode layer 220 generated by thermocompression is more than the adhesive force FA2 between the reinforcing film 310 and the transport film 320. The adhesion force FA3 between the outer region 310f of the reinforcing film 310 and the outer peripheral region 210f of the electrolyte membrane 210 generated by thermocompression bonding is reduced (FA1 <FA2), and the adhesion between the reinforcing film 310 and the transport film 320 is reduced. The heating temperature, pressurizing pressure, and thermocompression treatment time for the laminated body 100 are adjusted so as to be larger than the force FA2 (FA3> FA2).

  For example, in this example, the heating temperature for the laminate 100 is 150 ° C. or less, the pressure is 2 MPa or less, and the thermocompression treatment time is greater than 0 minutes and 20 minutes or less, more preferably 5 seconds or more and 5 minutes or less. Therefore, the above condition can be satisfied. After thermocompression bonding of the electrolyte membrane with catalyst layer 200 and the two-layer film 300, the transport film 320 is peeled from the laminate 100 (step S140).

  FIG. 5 is an explanatory view illustrating a state where the transport film is peeled from the laminate. Fig.5 (a) is explanatory drawing which illustrated the state which looked at the conveyance film 320 which peeled the laminated body 100 from the diagonal, and has shown the electrolyte membrane 200 with a catalyst layer translucently. FIG. 5B is an explanatory diagram illustrating a state in which the laminate 100 and the peeled transport film 320 are viewed from the side.

  As described above, in the laminate 100, the adhesive force FA1 between the inner region 310p of the reinforcing film 310 and the catalyst electrode layer 220 is smaller than the adhesive force FA2 between the reinforcing film 310 and the transport film 320 (FA1). <FA2), because the adhesive force FA3 between the outer region 310f of the reinforcing film 310 and the outer peripheral region 210f of the electrolyte membrane 210 is larger than the adhesive force FA2 between the reinforcing film 310 and the transport film 320 (FA3> FA2). When the transport film 320 is peeled from the laminate 100, the inner region 310p of the reinforcing film 310 is peeled together with the peel of the transport film 320. Thereby, the electrolyte membrane 200 with a catalyst layer will be in the state by which only the outer side area | region 310f of the reinforcement film 310 was stuck on the outer peripheral area | region 210f of the electrolyte membrane 210. FIG. That is, the electrolyte membrane with a catalyst layer reinforced by the reinforcing film is completed. Hereinafter, this finished product is also called a film-reinforced electrolyte membrane with a catalyst layer.

As can be seen from the above description, the laminate 100 of this example is
(1) Degree of slight adhesion provided in the transport film 320 (2) Method of forming the catalyst electrode layer 220 formed on the electrolyte membrane 210 (3) Three conditions of thermocompression bonding between the electrolyte membrane 200 with a catalyst layer and the two-layer film 300 By adjusting, first, the adhesive force FA2 between the reinforcing film 310 and the transport film 320 is larger than the adhesive force FA1 between the inner region 310p of the reinforcing film 310 and the catalyst electrode layer 220 (FA2> FA1). It has become. Therefore, when peeling the conveyance film 320 from the laminated body 100, it has suppressed that the inner area | region 310p of the reinforcement film 310 peels from the conveyance film 320. FIG.

  Also, by adjusting the above (1) to (3), the adhesive force FA2 between the reinforcing film 310 and the transport film 320 is between the outer peripheral region 210f of the electrolyte membrane 210 and the outer region 310f of the reinforcing film 310. The adhesive force FA3 is smaller (FA2 <FA3). Therefore, when the transport film 320 is peeled from the laminate 100, the outer region 310f of the reinforcing film 310 is prevented from peeling from the outer peripheral region 210f of the electrolyte membrane 210.

  FIG. 6 is an explanatory diagram for explaining a joining method of an electrolyte membrane with a catalyst layer and a reinforcing film in a conventional example. The electrolyte membrane with catalyst layer 500 shown in FIG. 6A has the same configuration as the electrolyte membrane with catalyst layer 200 of this example. That is, the catalyst layer-attached electrolyte membrane 500 includes a catalyst electrode layer 520 corresponding to the catalyst electrode layer 220 and an outer peripheral region 510f corresponding to the outer peripheral region 210f. The reinforcing film 600 has the same configuration as the outer region 310f of the reinforcing film 310 of this embodiment. That is, the reinforcing film 600 is a frame-shaped single layer film having an opening having a shape corresponding to the catalyst electrode layer 520.

  Conventionally, in the step of attaching a reinforcing film to an electrolyte membrane with a catalyst layer, a single frame-like reinforcing film 600 is directly attached to the outer peripheral region 510f of the electrolyte membrane 500 with a catalyst layer as shown in FIG. . However, in this case, it is difficult to align the reinforcing film 600 and the electrolyte membrane 500 with the catalyst layer, and the reinforcing film 600 is likely to be uneven. In addition, wrinkles and breakage were likely to occur due to dimensional changes caused by heating during thermocompression bonding. Further, since the reinforcing film 600 has a frame shape, it cannot be wound into a roll and is not easily transported. Thus, the conventional reinforcing film 600 has poor handling properties.

  On the other hand, since the shape of the reinforcing film 310 of the present embodiment is maintained by the transport film 320, the handling property when attached to the outer peripheral region 210f of the electrolyte membrane 210 is good, and the unevenness occurs in the reinforcing film 310. Hard to do. In addition, wrinkles and creases are less likely to occur during thermocompression bonding. In addition, the reinforcing film 310 can be wound up in a roll shape and can be easily transported.

B. Second embodiment:
In the first embodiment, the method of joining the sheet-like electrolyte membrane with a catalyst layer 200 cut into a predetermined size and the sheet-like two-layer film 300 has been described. A method for joining the band-shaped catalyst layer-attached electrolyte membrane 200 and the band-shaped two-layer film 300 will be described. The electrolyte membrane with catalyst layer 200 and the strip-shaped two-layer film 300 of the second embodiment are formed of the same material as the electrolyte membrane with catalyst layer 200 and the strip-shaped two-layer film 300 of the first embodiment, and only the shape is different.

  FIG. 7 is an explanatory diagram for explaining a method of joining the electrolyte membrane with a catalyst layer and the reinforcing film in the second embodiment. Fig.7 (a) is explanatory drawing which illustrated the half cut process of the two-layer film. FIG. 7B is an explanatory view illustrating the thermocompression bonding process of the electrolyte membrane with a catalyst layer and the two-layer film. FIG.7 (c) is explanatory drawing which illustrated the peeling process of the conveyance film. As shown in FIG. 7A, first, the belt-like two-layer film 300 is sequentially pulled out from a roll (not shown) and conveyed in the conveyance direction (arrow direction in FIG. 7A), while being rotated by a rotary die cutter 710 on the conveyance path. Make a half-cut. As a result, a plurality of inner regions 310p are formed at predetermined intervals in the band-shaped two-layer film 300.

  After half-cutting the two-layer film 300, as shown in FIG. 7 (b), the strip-shaped two-layer film 300 and the strip-shaped electrolyte membrane 200 with a catalyst layer are thermocompression bonded by a hot press roll press 720. At this time, in the electrolyte membrane with catalyst layer 200 and the two-layer film 300, the position of the catalyst electrode layer 220 of the electrolyte membrane with catalyst layer 200 and the position of the inner region 310p of the reinforcing film 310 coincide, and the outer peripheral region of the electrolyte membrane 210 It joins so that the position of 210f and the position of the outer side area | region 310f of the reinforcement film 310 may correspond. Thereby, the laminated body 100 with which the two-layer film 300 and the electrolyte membrane 200 with a catalyst layer were joined is formed.

  After forming the laminated body 100, as shown in FIG.7 (c), the conveyance film 320 is peeled from the laminated body 100 with the slitter 730. FIG. At this time, the inner region 310p of the reinforcing film 310 is peeled off along with the peeling of the transport film 320. By sequentially cutting the belt-like laminate 100 from which the transport film 320 and the inner region 310p of the reinforcing film 310 are peeled into a predetermined size, a film-reinforced electrolyte membrane with a catalyst layer is completed.

C. Evaluation example:
In order to evaluate the initial power generation performance and the cross leak resistance of the film-reinforced electrolyte membrane with a catalyst layer produced according to this example, an initial power generation performance test and a cycle durability test were performed. The evaluation test was performed on each of three samples (Experimental Example 1, Comparative Example 1, and Comparative Example 2). The film-reinforced electrolyte membrane with a catalyst layer of Example 1 was manufactured using the joining method shown in the second example.

The film-reinforced electrolyte membrane with a catalyst layer of Comparative Example 1 was produced by the following procedure.
(1) Half cut of the outer periphery of an inner side area is given with respect to one main surface of a strip | belt-shaped single layer reinforcement film.
(2) The reinforcing film and the electrolyte membrane with a catalyst layer are thermocompression-bonded so that the processed main surface subjected to half-cut is in contact with the electrolyte membrane.
(3) A half cut is performed on the thermocompression-bonded reinforcing film from the front-side main surface that is the main surface opposite to the processing-side main surface, and the inner region of the reinforcing film is removed.
(4) The strip-shaped laminate from which the inner region of the reinforcing film is removed is cut into a single wafer.

  The film-reinforced electrolyte membrane with a catalyst layer of Comparative Example 2 was produced using the joining method shown in the above Comparative Example (FIG. 6). That is, it was manufactured by attaching a single-layer frame-shaped reinforcing film to a sheet-like electrolyte membrane with a catalyst layer.

A fuel cell was constructed using each of the film-reinforced electrolyte membranes with catalyst layers of Example 1, Comparative Example 1 and Comparative Example 2, and an initial power generation performance test (cell temperature 80 ° C., overhumidity condition, current density 1.0 A / The output potential (V) in cm ² ) was measured. as a result,
Example 1: 0.586 (V), Comparative Example 1: 0.569 (V), Comparative Example 2: 0.574 (V).

  Since the output potential of Example 1 is higher than the output potential of Comparative Example 1, if the joining method according to the present invention is used, the power generation performance is higher than when the conventional joining method is used. It can be seen that a film-reinforced electrolyte membrane with a high catalyst layer can be produced. Moreover, since the output potential of Example 1 is a value comparable to the output potential of Comparative Example 2, if the bonding method according to the present invention is used, a continuous process of sequentially cutting the strip-shaped laminate is performed. Even when a film reinforced electrolyte membrane with a catalyst layer is produced, it can be seen that the power generation performance is equal to or higher than that of a film reinforced electrolyte membrane with a catalyst layer produced discontinuously by a conventional joining method. From this, even if it is a continuous process to which this invention is applied, it is thought that there is little influence of the initial damage by the burr | flash of a peeling surface, peeling residue, etc., or the contamination by multilayering of a film.

Next, a cycle durability test was performed on the fuel cells using the film-reinforced electrolyte membranes with catalyst layers of Example 1, Comparative Example 1 and Comparative Example 2, and the durability time until the occurrence of cross leak (hr ) Was measured. In the cycle endurance test, the cell temperature was 80 ° C., and the open circuit state and the state where the current density was 0.1 A / cm ² were repeated for 90 seconds. The presence or absence of the occurrence of cross leak was detected from the presence or absence of an increase in pressure on the sealed space side in contact with one main surface of the film-reinforced electrolyte membrane with a catalyst layer and on the sealed space side in contact with the other main surface. As a result, each endurance time is
Example 1: 230 (hr), Comparative Example 1: 60 (hr), Comparative Example 2: 215 (hr),
It became.

  Since the durability time of Example 1 is longer than the durability time of Comparative Example 1, if the joining method according to the present invention is used, the film with the catalyst layer having higher power generation performance than the case where the conventional joining method is used. It can be seen that a reinforced electrolyte membrane can be produced. In addition, the film reinforced electrolyte membrane with a catalyst layer of Comparative Example 1 had a cross leak in a relatively short time of 60 (hr) due to tearing in the vicinity of the opening end of the frame-shaped reinforcing film in the durability test. This is because, when a half-cut is made from the front side main surface of the reinforcing film to the laminate of the electrolyte film and the reinforcing film during the production of the film-reinforced electrolyte membrane with the catalyst layer, the blade causes damage to the electrolyte membrane. it is conceivable that. Moreover, since the durability time of Example 1 is comparable to the durability time of Comparative Example 2, if the joining method according to the present invention is used, the catalyst layer is formed by a continuous process of sequentially cutting the strip-shaped laminate. Even when the attached film-reinforced electrolyte membrane is manufactured, it can be seen that the film-reinforced electrolyte membrane with the catalyst layer manufactured discontinuously by the conventional joining method has the same or higher durability.

D. Variations:
The present invention is not limited to the above-described examples and embodiments, and can be implemented in various modes without departing from the gist thereof. For example, the following modifications are possible.

D-1. Modification 1:
FIG. 8 is an explanatory diagram for explaining a half-cut state of a two-layer film in a modified example. In this example, the half-cut of the two-layer film 300 has been described as not being cut (cut) in the transport film 320, but being cut (cut) so as to divide the reinforcing film 310 into two regions. Like the two-layer film 300b in FIG. 8A, not only the reinforcing film 310 but also a part of the transport film 320 may be provided with a cut. Moreover, like the layer film 300c shown in FIG.8 (b), an incision may be provided to such an extent that the reinforcement film 310 is not divided into two. In addition, the half cut of the two-layer film 300 may be provided with a cut in a perforated shape.

D-2. Modification 2:
In this embodiment, the electrolyte membrane 200 with a catalyst layer has been described as having the catalyst electrode layer 220 formed only on one main surface of the electrolyte membrane 210. However, the electrolyte membrane 200 with a catalyst layer is a membrane electrode assembly. Like (MEA), catalyst electrode layers may be formed on both sides of the electrolyte membrane.

D-3. Modification 3:
In this example, a two-layer film composed of the reinforcing film 310 and the transport film 320 was used. However, the multilayer film is not limited to two layers as long as it is a multilayer film partially including the reinforcing film 310. It may be a film. Moreover, although the Example demonstrated the structure which reinforces the electrolyte membrane 210 with a film, this invention is applicable also to the method of joining the face material for reinforcement other than a film to the electrolyte membrane 210. FIG.

D-4. Modification 4:
In the present embodiment, when the electrolyte membrane with catalyst layer 200 and the two-layer film 300 are laminated, the outer periphery of the inner region 310p and the outer periphery of the catalyst electrode layer 220 coincide with each other. The catalyst electrode layer 220 and the outer periphery do not necessarily coincide with each other. For example, the outer periphery of the inner region 310p may be located inside or outside the outer periphery of the catalyst electrode layer 220. Moreover, although the catalyst electrode layer 220 and the inner region 310p have been described as having a rectangular shape, they may each have a shape other than a rectangle.

D-5. Modification 5:
The adhesive force FA1 between the inner region 310p of the reinforcing film 310 and the catalyst electrode layer 220 depends on the method of forming the catalyst electrode layer 220 formed on the electrolyte membrane 210, and the heat between the electrolyte membrane with catalyst layer 200 and the two-layer film 300. The adhesive strength may be adjusted by factors other than the pressure bonding conditions. For example, the adhesive force FA1 may be reduced by setting the shape of the hot press so that the portion corresponding to the inner region 310p is not pressed.

D-6. Modification 6:
It can also be realized as a method of manufacturing a fuel cell that includes the joining method described in this embodiment as part of the process. For example, first, a reinforcing film is attached to the MEA using the bonding method of this embodiment, and an MEA with a reinforcing film is manufactured. Both sides of the MEA with the reinforcing film are sandwiched between gas diffusion layers, and further, both sides are sandwiched between a pair of separators to produce a fuel cell. A fuel cell having a stack structure can be manufactured by stacking a plurality of the fuel cells.

  In addition, a gas diffusion layer can be comprised with a porous gas diffusion layer base material. As the gas diffusion layer substrate, for example, a carbon porous body such as carbon paper or carbon cloth, or a metal porous body such as a metal mesh or a foam metal can be used. In order to obtain water repellency, the gas diffusion layer base material may be coated with a water repellent paste (water repellent treatment) to form a water repellent layer. As the water repellent paste, for example, a mixed solution of carbon powder and water repellent resin (polytetrafluoroethylene (PTFE), polyethylene, polypropylene, etc.) can be used.

  Moreover, a separator can be comprised with the member which has gas interruption | blocking property and electronic conductivity. The separator can be formed of, for example, a carbon member such as dense carbon that has been made to be gas-impermeable by compressing carbon, or a metal member such as press-formed stainless steel.

DESCRIPTION OF SYMBOLS 100 ... Laminated body 200 ... Electrolyte membrane with catalyst layer 210 ... Electrolyte membrane 220 ... Catalyst electrode layer 300 ... Two-layer film 310 ... Reinforcement film 320 ... Conveyance film 500 ... Electrolyte membrane 520 ... Catalyst electrode layer 600 ... Reinforcement film 710 ... Rotary die Cutter 720 ... Hot press roll press 730 ... Slitter

Claims (5)

A method of joining an electrolyte membrane comprising a catalyst electrode layer and a first film for reinforcing the electrolyte membrane,
A preparation step of preparing a laminated film obtained by laminating the first film, a second film different from the first film, and an electrolyte membrane including the catalyst electrode layer;
A cutting step of providing a cut at the boundary between the inner region set in the first film of the laminated film and the outer region formed in the outer peripheral portion of the inner region;
A crimping step of thermocompression bonding the laminated film and the electrolyte membrane in a state where the inner electrode region where the cut is provided at the boundary with the outer region and the catalyst electrode layer are in contact with each other;
And a peeling step of peeling the inner region of the first film together with the second film from the laminated body of the laminated film and the electrolyte membrane which are thermocompression bonded. The bonding method according to claim 1,
The preparation step includes a step of preparing an electrolyte membrane in which a catalyst electrode layer is formed in a partial region of the main surface,
The cutting step includes a step of cutting the first film with the shape of the catalyst electrode layer formed on the electrolyte membrane as the shape of the inner region,
In the peeling step, in the state where the outer region of the frame-shaped first film is left in a region where the catalyst electrode layer is not formed in the electrolyte membrane, the first film is formed together with the second film. A bonding method including a step of peeling the inner region. In the joining method according to claim 1 or 2,
The electrolyte membrane provided with the catalyst electrode layer prepared in the preparation step is thermocompression bonded to the surface of the catalyst electrode layer with a test electrolyte membrane different from the electrolyte membrane, and is 180 ° with respect to the test electrolyte membrane. The test force when the peel test is performed is 5 N / m or less,
In the pressure bonding step, the thermocompression bonding between the laminated film and the electrolyte membrane is a bonding method in which a pressure bonding temperature is 150 ° C. or less, a pressure bonding pressure is 2 MPa or less, and a pressure bonding time is greater than 0 minutes and 20 minutes or less. In the joining method in any one of Claims 1 thru | or 3,
The first film is formed of polyethylene naphthalate,
The joining method, wherein the second film is formed of polyethylene terephthalate. A fuel cell manufacturing method comprising:
Preparing the electrolyte membrane to which the first film is bonded by the bonding method according to claim 1;
Disposing gas diffusion layers on both sides of the electrolyte membrane to which the first film is bonded;
And a step of arranging a pair of separators on both sides of the laminate of the gas diffusion layer and the electrolyte membrane.

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