JP5266734B2 - Electrolyte membrane-catalyst layer assembly with reinforcing sheet, electrolyte membrane-electrode assembly with reinforcing sheet, solid polymer fuel cell, and method for producing electrolyte membrane-catalyst layer assembly with reinforcing sheet - Google Patents

Description

The present invention includes a membrane with reinforcing sheet - electrode assembly, a polymer electrolyte fuel cell and the reinforcing sheet laminated membrane - - catalyst layer assembly, the electrolyte membrane with reinforcing sheets using the same method of manufacturing a catalyst layer assembly Is.

  A fuel cell is a cell in which electrodes are arranged on both sides of an electrolyte and generates electricity by an electrochemical reaction between hydrogen and oxygen, and only water is generated during power generation. Thus, unlike the conventional internal combustion engine, it is expected to spread as a next-generation clean energy system because it does not generate environmental load gas such as carbon dioxide. In particular, the polymer electrolyte fuel cell has a low operating temperature and low electrolyte resistance. In addition, it uses a highly active catalyst, so it can obtain high output even in a small size. Is expected to be put to practical use.

  This polymer electrolyte fuel cell uses a solid polymer electrolyte membrane having proton conductivity, and a catalyst layer and a gas diffusion layer are sequentially laminated on both surfaces of the electrolyte membrane. And it has the structure which has arrange | positioned the gasket so that the circumference | surroundings of the electrode which consists of this catalyst layer and a gas diffusion layer may be enclosed, and also this was pinched | interposed with the separator (for example, refer FIG. 2 of patent document 1). Further, since the gasket is installed so as to surround the outer side of the electrode from the viewpoint of positional accuracy, a gap is formed between the gasket and the electrode, and the electrolyte membrane corresponding to this gap portion is an electrode. It is in a state where it is not pressed by either of the gaskets. Here, when power generation / non-power generation is repeated in the polymer electrolyte fuel cell, the electrolyte membrane repeats a wet state and a dry state, but the electrolyte membrane corresponding to the gap is pressed by an electrode or a gasket. Therefore, expansion and contraction are repeated. As a result, there is a problem that stress is generated in the electrolyte membrane and fatigues, and the electrolyte membrane is damaged.

In order to solve this problem, for example, the polymer electrolyte fuel cell disclosed in Patent Document 1 further includes a reinforcing film in a gap between the electrode and the gasket. This reinforcing membrane is formed in a frame shape having an opening at the center portion, like the gasket, and its outer peripheral edge is sandwiched between the gasket and the electrolyte membrane, and its inner peripheral edge is separated from the separator. It is sandwiched between the gas diffusion layers. As described above, the polymer electrolyte fuel cell of Patent Document 1 restrains the expansion / contraction of the electrolyte membrane by restraining the gap between the gasket and the electrode by the reinforcing membrane.
Japanese Patent No. 3052536

  In the polymer electrolyte fuel cell using the reinforcing membrane as described above, the reinforcing membrane is usually welded to the electrolyte membrane-electrode assembly by thermocompression bonding, that is, by applying pressure in a heated state. The pressure at this time is usually about 0.5 to 5.0 MPa, but by applying such a pressure, the reinforcing membrane is embedded in the electrolyte membrane or electrode to be welded to the reinforcing membrane. As a result, the mechanical strength of the electrolyte membrane or electrode may be reduced.

  Accordingly, the present invention provides an electrolyte membrane-catalyst layer assembly with a reinforcing sheet that does not reduce the mechanical strength of the electrolyte membrane, an electrolyte membrane-electrode assembly with a reinforcing sheet, and a solid polymer fuel cell using the same. The issue is to provide.

  The electrolyte membrane-catalyst layer assembly with a reinforcing sheet according to the present invention is made to solve the above problems, and is formed on both surfaces of the solid polymer electrolyte membrane and the electrolyte membrane except for the outer peripheral edge portion. Each of the reinforcing sheets is provided with a catalyst layer and a frame-shaped reinforcing sheet having an opening in the center, which are respectively installed on both surfaces of the electrolyte membrane-catalyst layer assembly including the electrolyte membrane and the catalyst layer. The catalyst layer is adhered to the outer peripheral edge portion of the catalyst layer and the outer peripheral edge portion of the electrolyte membrane so that the catalyst layer is exposed from the opening except for the outer peripheral edge portion.

  According to this configuration, the reinforcing sheet is placed on the electrolyte membrane-catalyst layer assembly by adhering to the outer peripheral edge of the catalyst layer and the outer peripheral edge of the electrolyte membrane. As described above, since the reinforcing sheet is installed on the electrolyte membrane-catalyst layer assembly by adhesion, it is possible to reduce the applied pressure as compared with the case of installing by thermocompression bonding. As a result, the reinforcing sheet is installed. It is possible to prevent the mechanical strength from being lowered without being penetrated into the electrolyte membrane or the catalyst layer.

Ru engages the present invention reinforcement sheet laminated membrane - electrode assembly, the reinforcing sheet with the electrolyte membrane described above - has a catalyst layer assembly, a thickness more than the thickness of the reinforcing sheet, the opening of the reinforcing sheet And a gas diffusion layer formed on the catalyst layer exposed from the portion.

  According to this configuration, since the electrolyte membrane-catalyst layer assembly with the reinforcing sheet is provided, the reinforcing sheet is installed on the electrolyte membrane-catalyst layer assembly by adhesion rather than thermocompression bonding. Compared with the case where it does, it becomes possible to reduce the applied pressure, and as a result, it is possible to surely prevent the mechanical strength from being lowered without being embedded in the electrolyte membrane and the catalyst layer when the reinforcing sheet is installed. . Moreover, since the gas diffusion layer is formed on the catalyst layer exposed from the opening of the reinforcing sheet, it can reliably contact the catalyst layer. In addition, since the thickness of the gas diffusion layer is thicker than the thickness of the reinforcing sheet, the gas diffusion layer can be surely brought into contact with a separator usually installed thereon.

Moreover, the electrolyte membrane-electrode assembly with a reinforcing sheet according to the present invention includes a solid polymer electrolyte membrane, catalyst layers formed on both surfaces except for the outer peripheral edge of the electrolyte membrane, and on each catalyst layer. A gas diffusion layer formed on each side, and a frame-shaped reinforcing sheet having an opening in the center, installed on both surfaces of the electrolyte membrane-catalyst layer and the gas diffusion layer. , each reinforcing sheet, so that the gas diffusion layer from the opening to expose except the outer peripheral edge portion, and adheres to the outer peripheral edge portion of the outer peripheral edge portion and the electrolyte membrane of the gas diffusion layer, wherein In the reinforcing sheet, the outer peripheral edges protruding from the electrolyte membrane are adhered to each other.

  According to this configuration, the reinforcing sheet is placed on the electrolyte membrane-electrode assembly by adhering to the outer peripheral edge of the gas diffusion layer and the outer peripheral edge of the electrolyte membrane. Thus, since the reinforcing sheet is installed on the electrolyte membrane-electrode assembly by adhesion, it is possible to reduce the applied pressure as compared with the case of installing by thermocompression bonding. As a result, the reinforcing sheet is installed. It is possible to prevent the mechanical strength from being lowered without being penetrated into the electrolyte membrane or electrode.

Each of the reinforcing sheets is preferably composed of an adhesive layer that adheres to the electrolyte membrane-electrode assembly and a gas barrier layer that prevents permeation of fuel gas and oxidant gas. Thus, by providing a gas barrier layer, gas leak can be prevented more reliably. Each of the reinforcing sheets is preferably adhered by a material including at least one of an acrylic adhesive, a rubber adhesive, and a silicone adhesive. It is preferable that the outer peripheral edge parts which protruded from the said electrolyte membrane have adhered the said reinforcement sheet. It is preferable that the outer peripheral edge of the gas diffusion layer and the inner peripheral edge of the reinforcing sheet are separated from each other. It is preferable that the distance from the outer periphery of the gas diffusion layer to the inner periphery of the reinforcing sheet is greater than 0 mm and 5 mm or less.

Also, the solid polymer fuel cell according to the present invention is the above-mentioned each reinforcing sheet so as to surround each of the electrolyte membrane-electrode assembly with any of the above-described reinforcing sheets, and each electrode comprising the catalyst layer and the gas diffusion layer. And a gasket installed on each of the electrodes, and a separator installed on each of the electrodes and the gasket. The polymer electrolyte fuel cell according to the present invention includes a solid polymer electrolyte membrane, catalyst layers formed on both surfaces except for the outer peripheral edge of the electrolyte membrane, and formed on each of the catalyst layers. Gas diffusion layers, and frame-shaped reinforcing sheets each having an opening in the center, which are respectively installed on both surfaces of the electrolyte membrane-catalyst layer and the electrolyte membrane-electrode assembly including the gas diffusion layer, The reinforcing sheet is attached to the outer peripheral edge of the gas diffusion layer and the outer peripheral edge of the electrolyte membrane so that the gas diffusion layer is exposed from the opening except for the outer peripheral edge. A membrane-electrode assembly, a gasket respectively installed on each reinforcing sheet so as to surround each electrode comprising the catalyst layer and the gas diffusion layer, and a separator respectively installed on each electrode and gasket It is equipped with a.

According to this configuration, since the above-described electrolyte membrane-electrode assembly with a reinforcing sheet is provided, the reinforcing sheet adheres to the outer peripheral edge portion of the gas diffusion layer and the outer peripheral edge portion of the electrolyte membrane. It is installed in the electrode assembly. Thus, since the reinforcing sheet is installed on the electrolyte membrane-electrode assembly by adhesion, it is possible to reduce the applied pressure as compared with the case of installing by thermocompression bonding. As a result, the reinforcing sheet is installed. It is possible to prevent the mechanical strength from being lowered without being penetrated into the electrolyte membrane or electrode . Also, the reinforcing sheet with the electrolyte membrane according to the present invention - method of manufacturing an electrode assembly includes the steps of preparing a solid polymer electrolyte membrane, forming a catalyst layer on both sides excluding the outer peripheral edge of the electrolyte membrane And a step of installing a frame-shaped reinforcing sheet having an opening in the center on the upper and lower surfaces of the electrolyte membrane-catalyst layer assembly comprising the electrolyte membrane and the catalyst layer, and the catalyst layer from the opening to the outer periphery. Adhering each of the reinforcing sheets onto the outer peripheral edge of the catalyst layer and the outer peripheral edge of the electrolyte membrane so as to be exposed except the portion. Moreover, the manufacturing method of the electrolyte membrane-electrode assembly with a reinforcing sheet according to the present invention includes a step of preparing a solid polymer electrolyte membrane, and a step of forming a catalyst layer on both surfaces excluding the outer peripheral edge of the electrolyte membrane; And a step of forming a gas diffusion layer on each catalyst layer, and a frame-shaped reinforcing sheet having an opening in the center on both surfaces of the electrolyte membrane-catalyst layer and the electrolyte membrane-electrode assembly comprising the gas diffusion layer. And a step of adhering the reinforcing sheets on the outer peripheral edge of the gas diffusion layer and the outer peripheral edge of the electrolyte membrane so that the gas diffusion layer is exposed from the opening except the outer peripheral edge. possess the door, the reinforcing sheet, the outer peripheral edge portions of protruding from the electrolyte membrane is adhered. In the step of adhering, the reinforcing sheet is preferably pressure-bonded at a pressure of 0.1 to 0.3 MPa.

  According to the present invention, there are provided an electrolyte membrane-catalyst layer assembly with a reinforcing sheet without reducing the mechanical strength of the electrolyte membrane, an electrolyte membrane-electrode assembly with a reinforcing sheet, and a solid polymer fuel cell using the same. Can be provided.

  Hereinafter, embodiments of an electrolyte membrane-catalyst layer assembly with a reinforcing sheet, an electrolyte membrane-electrode assembly with a reinforcing sheet, and a polymer electrolyte fuel cell according to the present invention will be described with reference to the drawings. FIG. 1 is a front sectional view of a polymer electrolyte fuel cell according to this embodiment, FIG. 2 is a plan view of the polymer electrolyte fuel cell according to this embodiment, and FIG. 3 is an electrolyte membrane-electrode assembly with a reinforcing sheet. It is an expanded front sectional view which shows the detail of the outer periphery part. In FIG. 2, the description of the separator and the gasket is omitted for easy understanding.

  As shown in FIGS. 1 and 2, the polymer electrolyte fuel cell 1 includes an electrolyte membrane 2 having a rectangular shape in plan view, and a plan view that is slightly smaller than the electrolyte membrane 2 on the upper and lower surfaces of the electrolyte membrane 2. A rectangular catalyst layer 3 is formed. A structure in which the catalyst layer 3 is formed on both surfaces of the electrolyte membrane 2 is referred to as an electrolyte membrane-catalyst layer assembly 10. Thus, since the catalyst layer 3 is formed slightly smaller than the electrolyte membrane 2, the catalyst layer 3 is not formed on the outer peripheral edge 21 of the electrolyte membrane 2. In addition, it is preferable that the distance C (refer FIG. 3) from the outer periphery of the electrolyte membrane 2 to the outer periphery of the catalyst layer 3 is 0.1-5 mm.

  And the frame-shaped reinforcement sheet 4 which has the opening part 41 in the center is installed in the upper surface and lower surface of this electrolyte membrane-catalyst layer assembly 10, respectively. The reinforcing sheet 4 includes a gas barrier layer 42 that prevents permeation of fuel gas and oxidant gas used for power generation of the fuel cell, and an adhesive layer 43 that adheres to the electrolyte membrane-catalyst layer assembly 10. The layer 43 is directed to the electrolyte membrane-catalyst layer assembly 10 side. The thickness of the gas barrier layer 42 is preferably 5 to 50 μm, and the thickness of the adhesive layer 43 is preferably 1 to 50 μm. In a state where the reinforcing sheet 4 is installed on the electrolyte membrane-catalyst layer assembly 10, the catalyst layer 3 is exposed from the opening 41 of the reinforcing sheet 4 except for the outer peripheral edge portion 31, and the outside of the catalyst layer 3. The reinforcing sheet 4 is adhered to the peripheral edge 31 and the outer peripheral edge 21 of the electrolyte 2. In addition, it is preferable that the distance B (refer FIG. 3) from the outer periphery of the catalyst layer 3 to the inner periphery of the reinforcement sheet 4 shall be 1-10 mm. Further, since the reinforcing sheet 4 is formed to be slightly larger than the electrolyte membrane 2, the outer peripheral edge portions 45 of the reinforcing sheets 4 protruding from the electrolyte membrane 2 are adhered to each other outside the electrolyte membrane 2. The distance D (see FIG. 3) from the outer peripheral edge of the reinforcing sheet 4 to the outer peripheral edge of the electrolyte membrane 2 is preferably 1 to 100 mm. As described above, the electrolyte membrane-catalyst layer assembly 10 provided with the reinforcing sheet 4 corresponds to the reinforcing membrane-attached electrolyte membrane-catalyst layer assembly of the present invention.

  A gas diffusion layer 5 having a rectangular shape in plan view is provided on the catalyst layer 3 exposed from the opening 41 of the reinforcing sheet 4. The distance A (see FIG. 3) from the outer peripheral edge of the gas diffusion layer 5 to the inner peripheral edge of the reinforcing sheet 4 is preferably 0 to 5 mm. Thus, the gas diffusion layer 5 is formed on the catalyst layer 3 to constitute the electrode E, and the electrode E formed on both surfaces of the electrolyte membrane 2 is called an electrolyte membrane-electrode assembly 20. In addition, like this embodiment, what the reinforcing sheet 4 is installed in the electrolyte membrane-electrode assembly 20 corresponds to the electrolyte membrane-electrode assembly with a reinforcing sheet of the present invention.

  A frame-like gasket 6 is installed on the reinforcing sheet 4 so as to surround the periphery of the electrode E, and a separator 7 is installed on the electrode E and the gasket 6. In the separator 7, a gas flow path 71 is formed in a region facing the gas diffusion layer 5.

  Next, the material of each component of the polymer electrolyte fuel cell 1 configured as described above will be described.

  The electrolyte membrane 2 is formed, for example, by applying a solution containing a hydrogen ion conductive polymer electrolyte on a substrate and drying it. Examples of the hydrogen ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, more specifically, a perfluorocarbonsulfonic acid-based resin in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. Examples include polymers (PFS polymers). By introducing a fluorine atom having high electronegativity, it is chemically very stable, the dissociation degree of the sulfonic acid group is high, and high ion conductivity can be realized. Specific examples of such a hydrogen ion conductive polymer electrolyte include “Nafion” (registered trademark) manufactured by DuPont, “Flemion” (registered trademark) manufactured by Asahi Glass Co., Ltd., and “Aciplex” manufactured by Asahi Kasei Corporation. ”(Registered trademark),“ Gore Select ”(registered trademark) manufactured by Gore, and the like. The concentration of the hydrogen ion conductive polymer electrolyte contained in the hydrogen ion conductive polymer electrolyte-containing solution is usually about 5 to 60% by weight, preferably about 20 to 40% by weight. In addition, the film thickness of the electrolyte membrane 2 is about 20-250 micrometers normally, Preferably it is about 20-80 micrometers.

  The catalyst layer 3 is a known platinum-containing catalyst layer (cathode catalyst and anode catalyst). Specifically, the catalyst layer 3 contains carbon particles supporting catalyst particles and a hydrogen ion conductive polymer electrolyte. Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compound include an alloy of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron and the like. In general, the catalyst particles contained in the cathode catalyst layer are platinum, and the catalyst particles contained in the anode catalyst layer are an alloy of the metal and platinum. Moreover, as a hydrogen ion conductive polymer electrolyte, the same material as what is used for the electrolyte membrane 2 mentioned above can be used.

  The reinforcing sheet 4 includes a gas barrier layer 42 and an adhesive layer 43. The gas barrier layer 42 is made of polyester, polycarbonate, polyamide, polyimide, polysulfone having barrier properties against water vapor, water, fuel gas, and oxidant gas, Polymethylpentene, polyphenylene oxide, polysulfone, polyether ether ketone, polyphenylene sulfide and the like can be preferably used. Specific examples of the polyester include polyethylene terephthalate, polyethylene naphthalate, polybutylene terephthalate, polybutylene naphthalate, and the like.

  In addition, as the material of the adhesive layer 43, for example, an acrylic, rubber, or silicone adhesive can be used. Specifically, acrylic ester copolymers, methacrylic ester copolymers, natural rubber (NR), synthetic natural rubber (IR), styrene-butadiene rubber (SBR), polyisobutylene (PIB), butyl rubber (IIR) And silicone rubber.

  As the gas diffusion layer 5, various types of gas diffusion layers constituting a fuel electrode and an air electrode can be used. In order to efficiently supply fuel gas and oxidant gas as fuel to the catalyst layer 3, the gas diffusion layer 5 is porous. It is made of a conductive substrate. Examples of the porous conductive substrate include carbon paper and carbon cloth.

  As the gasket 6, it is possible to use a gasket that has a strength sufficient to withstand heat pressing and has a gas barrier property that does not leak fuel and oxidant to the outside. For example, a polyethylene terephthalate sheet or Teflon ( (Registered trademark) sheet, silicon rubber sheet, and the like.

  The separator 7 may be any known conductive plate that is known and stable even in the environment within the fuel cell. In general, a carbon plate in which a gas flow path 71 is formed is used. In addition, the separator 7 is made of a metal such as stainless steel, and the surface of the metal is formed with a coating made of a conductive material such as chromium, a platinum group metal or oxide thereof, or a conductive polymer. It is also possible to use a metal having a metal surface plated with a material such as silver, a platinum group composite oxide, or chromium nitride.

  Next, a method for producing the above-described polymer electrolyte fuel cell 1 will be described with reference to the drawings. FIG. 4 is an explanatory view showing a method for producing the polymer electrolyte fuel cell 1 according to this embodiment.

  First, the electrolyte membrane 2 made of the above-described material is prepared, and the catalyst layer forming transfer sheet 8 is placed on both surfaces of the electrolyte membrane 2 (FIG. 4A). Here, the transfer sheet 8 for forming a catalyst layer is one in which the transferred catalyst layer 3 is formed on a transfer substrate 81. The production method of the catalyst layer forming transfer sheet 8 will be described. First, the above-described carbon particles supporting the catalyst particles and the hydrogen ion conductive polymer electrolyte are mixed and dispersed in an appropriate solvent to prepare a catalyst paste. . Then, the catalyst paste is applied onto the transfer substrate 81 through a release layer as necessary in accordance with a known method so that the formed catalyst layer 3 has a desired film thickness. At this time, the catalyst paste is applied to the transfer substrate 81 so that the catalyst layer 3 has a shape slightly smaller than the electrolyte membrane 2. Examples of the method for applying the catalyst paste include known coating methods such as screen printing, spray coating, die coating, and knife coating. Examples of the solvent include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Of these, alcohols are preferable. Examples of alcohols include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, and tert-butanol, and various polyhydric alcohols. As the transfer substrate 81, for example, polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, polyethylene naphthalate. And the like. In addition, heat resistance of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. Fluorine resin can also be used. Further, the transfer substrate 81 may be coated paper such as art paper, coated paper, lightweight coated paper, non-coated paper such as notebook paper, copy paper, etc. in addition to the polymer film. The thickness of the transfer substrate 81 is usually about 6 to 100 μm, preferably about 10 to 30 μm, from the viewpoints of handleability and economy. Therefore, the transfer substrate 81 is preferably a polymer film that is inexpensive and easily available, and more preferably polyethylene terephthalate.

  Then, after applying the catalyst paste, the catalyst layer 3 is formed on the transfer substrate 81 by drying at a predetermined temperature and time. A drying temperature is about 40-100 degreeC normally, Preferably it is about 60-80 degreeC. Although depending on the drying temperature, the drying time is usually about 5 minutes to 2 hours, preferably about 10 minutes to 1 hour.

  Continuing the description of the method for producing a polymer electrolyte fuel cell, the transfer sheet 8 for forming a catalyst layer produced as described above is arranged so that the catalyst layer 3 faces the electrolyte membrane 1 (FIG. 4 (a)). Then, a heat press is applied from the back side of the transfer sheet 8 to transfer the catalyst layer 3 to the electrolyte membrane 2, and the transfer substrate 81 of the transfer sheet 8 is peeled off (FIG. 4B). In consideration of workability, it is preferable to simultaneously laminate the catalyst layer 3 on both surfaces of the electrolyte membrane 2, but the catalyst layer 3 can also be formed on each side. The pressure level of the heating press is usually about 0.5 to 20 MPa, preferably about 1 to 10 MPa in order to avoid transfer failure. Further, it is preferable to heat the pressing surface during this pressing operation in order to avoid transfer failure. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower, in order to avoid damage or deformation of the electrolyte membrane 2. Thus, the electrolyte membrane-catalyst layer assembly 10 is formed by forming the catalyst layers 3 on both surfaces of the electrolyte membrane 2. At this time, since the catalyst layer 3 is slightly smaller than the electrolyte membrane 2, the outer peripheral edge 21 of the electrolyte membrane 2 is exposed.

  Next, the reinforcing sheet 4 is attached to the electrolyte membrane-catalyst layer assembly 10 thus formed (FIG. 4C). More specifically, the reinforcing sheets 4 are respectively disposed on the upper and lower surfaces of the electrolyte membrane-catalyst layer assembly 10. At this time, the reinforcing sheets 4 are arranged so that the adhesive layers 43 of the reinforcing sheets 4 face each other. The reinforcing sheet 4 is adhered onto the outer peripheral edge 31 of the catalyst layer 3 and the outer peripheral edge 21 of the electrolyte membrane 2 so that the catalyst layer 3 is exposed from the opening 41 of the reinforcing sheet 4 except for the outer peripheral edge 31. Let Various methods can be adopted as a method for adhering the reinforcing sheet 4 to the outer peripheral edge 31 or the like of the catalyst layer 3 at this time. For example, the hand roller can be adhered by rolling on the reinforcing sheet 4. Alternatively, it can be crimped by a press or the like. In addition, the pressure in the case of making it adhere | attach is enough for the pressure considerably lower than the pressure in the case of carrying out thermocompression bonding, for example, the reinforcement sheet | seat 4 is enough for the outer periphery of the catalyst layer 3 by the pressure of about 0.1-0.3MPa. Adhere to the part 31 and the like.

  Subsequently, the gas diffusion layer 5 is laminated by thermocompression bonding on the catalyst layer 3 exposed from the opening 41 of the electrolyte membrane-catalyst layer assembly described above, and the electrolyte membrane-electrode with the reinforcement sheet The joined body is completed (FIG. 4D). And the gasket 6 is arrange | positioned on the reinforcement sheet 4 so that the circumference | surroundings of the electrode E which consists of the catalyst layer 3 and the gas diffusion layer 5 may be enclosed. Further, the separator 7 is disposed on the gas diffusion layer 5 and the gasket 6 so that the gas flow path 71 faces the gas diffusion layer 5 so that the gas diffusion layer 5 and the separator 7 are electrically connected. By sandwiching the electrolyte membrane-electrode assembly with the separator 7, the solid polymer fuel cell 1 is completed (FIG. 4E).

  As described above, in the present embodiment, the outer peripheral edge portion 21 of the electrolyte membrane 2 is restrained by the reinforcing sheet 4, so that the expansion / contraction of the electrolyte membrane 2 can be suppressed, and as a result, the electrolyte membrane 2. Can be prevented from being damaged. The reinforcing sheet 4 is disposed on both surfaces of the electrolyte membrane-catalyst layer assembly 10. The reinforcing sheet 4 adheres to the outer peripheral edge 31 of the catalyst layer 3 and the outer peripheral edge 21 of the electrolyte membrane 2. Yes. Since the reinforcing sheet 4 is installed in the electrolyte membrane-catalyst layer assembly 10 by sticking in this way, the reinforcing sheet 4 is joined to the electrolyte membrane-catalyst layer assembly as compared with the case where the reinforcing sheet 4 is installed by thermocompression bonding. It becomes possible to reduce the pressure when doing. Therefore, the reinforcing sheet 4 can be prevented from sinking into the catalyst layer 3 and the electrolyte 2, and consequently the mechanical strength of the catalyst layer and the electrolyte membrane can be prevented from being lowered. The reinforcing sheet 4 is welded on the outer peripheral edge 21 of the electrolyte membrane 2 and the outer peripheral edge 31 of the catalyst layer 3, but is not placed on the gas diffusion layer 5. For this reason, a flat surface is formed on the gas diffusion layer 5, and the separator 7 installed on the gas diffusion layer 5 is in uniform contact with the gas diffusion layer 5. Therefore, the problem that the current collection efficiency of the separator 7 is reduced does not occur.

  As mentioned above, although embodiment of this invention was described, this invention is not limited to these, A various change is possible unless it deviates from the meaning of this invention. For example, in the above embodiment, the reinforcing sheet 4 adheres on the outer peripheral edge 31 of the catalyst layer 3, but as shown in FIG. 5, it may adhere to the outer peripheral edge 51 of the gas diffusion layer 5. Good. More specifically, the polymer electrolyte fuel cell 1 includes an electrolyte membrane 2 having a rectangular shape in plan view, and is slightly smaller than the electrolyte membrane 2 on the upper and lower surfaces of the electrolyte membrane 2, that is, the electrolyte membrane 2. The catalyst layer 3 is formed except for the outer peripheral edge portion 21. A gas diffusion layer 5 is formed on each catalyst layer 3. The gas diffusion layer 5 has substantially the same area as the catalyst layer 3. The reinforcing sheets 4 are respectively disposed on both surfaces of the electrolyte membrane-electrode assembly 20 including the electrolyte membrane 2, the catalyst layer 3, and the gas diffusion layer 5. The gas diffusion layer 5 is exposed from the opening 41 of the reinforcing sheet 4 except for the outer peripheral edge 51. The reinforcing sheet 4 adheres to the outer peripheral edge portion 51 of the gas diffusion layer 5 and the outer peripheral edge portion 21 of the electrolyte membrane 2, and the adhesive layer 43 between the outer peripheral edge portions 45 protruding from the electrolyte membrane 2 Adhesive and bonded.

  Moreover, in the said embodiment, although the reinforcement sheet 4 is comprised from two layers, the gas barrier layer 42 and the adhesion layer 43, it is not necessarily limited to this layer structure, For example, it can also be set as three or more layers. .

  In the above embodiment, the electrolyte membrane 2, the catalyst layer 3, and the gas diffusion layer 5 constituting the solid polymer fuel cell 1 are all described as a rectangular shape in plan view, but the shape is not particularly limited, For example, it can be a circular shape in plan view.

  The present invention will be described more specifically with reference to the following examples. In addition, this invention is not limited to the following Example.

Example 1
As the electrolyte membrane 2, NRE212CS (manufactured by Dupont) having a film thickness of 53 μm cut to a size of 63 × 63 mm was used.

Next, a catalyst-forming transfer sheet 8 was produced in the following manner. First, 2 g of platinum catalyst-supported carbon (platinum supported amount: 45.7 wt%, manufactured by Tanaka Kikinzoku Co., Ltd., TEC10E50E), 1 g of 1-butanol, 10 g of 3-butanol, 20 g of a fluororesin (5 wt% Nafion binder, manufactured by DuPont) and 6 g of water was added, and these were stirred and mixed with a disperser to prepare an ink composition for forming a catalyst. Next, the ink was applied to a polyester film (Toray, X44, 25 μm) so that the weight of platinum after drying the catalyst layer was 0.4 mg / cm ² to prepare a transfer sheet 8 for forming a catalyst.

  The catalyst-forming transfer sheet 8 produced as described above was cut into a size of 60 × 60 mm, and placed on both surfaces of the electrolyte membrane 2 so that the catalyst layer 3 was directed to the electrolyte membrane 2 side. The catalyst layer 3 was formed on both surfaces of the electrolyte membrane 2 by hot pressing under conditions of 135 ° C., 5.0 MPa, 150 seconds, and the electrolyte membrane-catalyst layer assembly 10 was produced. The catalyst layer 3 has a thickness of 20 μm.

  Subsequently, Proswell (manufactured by Nitto Denko Corporation, PW-3610A) was used as the reinforcing sheet 4. The proswell is composed of a gas barrier layer 43 made of polyimide having a thickness of 25 μm and an adhesive layer 42 made of acrylic resin having a thickness of 10 μm. The reinforcing sheet 4 was cut to a size of 80 × 80 mm, and an opening 41 having a size of 50 × 50 mm was formed at the center. Then, the reinforcing sheet 4 is placed centering on both surfaces of the electrolyte membrane-catalyst layer assembly 10, and the reinforcing sheet 4 is welded to the electrolyte membrane-catalyst layer assembly 10 by pressure bonding with a pressure of 0.3 MPa, An electrolyte membrane-catalyst layer assembly with a reinforcing sheet was produced.

  Subsequently, on the catalyst layer 3 exposed from the opening 41, a carbon paper (TGP-H-090, manufactured by Toray Industries, Inc., thickness 280 μm) cut into a size of 49 × 49 mm as the gas diffusion layer 5 is used. ) To form an electrolyte membrane-electrode assembly with a reinforcing sheet.

(Evaluation method)
The electrolyte membrane-electrode assembly with a reinforcing sheet of Example 1 prepared as described above was embedded in an epoxy resin and polished so that the cross section of the electrolyte membrane-electrode assembly with a reinforcing sheet could be observed. FIG. 6 is an SEM photograph of this cross section. From FIG. 6, in the electrolyte membrane-electrode assembly with a reinforcing sheet according to Example 1, the reinforcing sheet 4 is not recessed into the electrolyte 2 and the catalyst layer 3, and the electrolyte membrane 2 and the catalyst layer 3 are not deformed. Was confirmed.

  Moreover, about the electrolyte membrane-electrode assembly with a reinforcing sheet of Example 1, the gasket 6 and the separator 7 were installed, the polymer electrolyte fuel cell was created, and the load fluctuation cycle test was implemented. The measurement conditions at this time were a cell temperature of 80 ° C., a fuel utilization rate of 70%, an oxidant utilization rate of 40%, and a humidification temperature of 50 ° C. As a result of the current voltage measurement evaluation, the durability time of the fuel cell of Example 1 was 1000 hours, and no damage to the electrolyte membrane 2 was observed after the evaluation.

1 is a front sectional view showing an embodiment of a polymer electrolyte fuel cell according to the present invention. 1 is a plan view showing an embodiment of a polymer electrolyte fuel cell according to the present invention. It is an expanded front sectional view showing details of an outer periphery part of an electrolyte membrane-electrode assembly with a reinforcing sheet concerning this embodiment. It is explanatory drawing which shows the manufacturing method of the polymer electrolyte fuel cell which concerns on this embodiment. It is front sectional drawing which shows other embodiment of the polymer electrolyte fuel cell which concerns on this invention. It is the SEM photograph (a) of the electrolyte membrane-electrode assembly with a reinforcement sheet which concerns on the present Example 1, and its enlarged view (b).

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Polymer electrolyte fuel cell 2 Electrolyte membrane 21 Outer peripheral edge part 3 of electrolyte membrane Catalyst layer 31 Outer peripheral edge part 4 of catalyst layer Reinforcement sheet 41 Opening part 42 Gas barrier layer 43 Adhesive layer 45 Outer peripheral edge part 5 of reinforcement sheet Gas diffusion layer 6 Gasket 7 Separator 10 Electrolyte membrane-catalyst layer assembly 20 Electrolyte membrane-electrode assembly

Claims (13)

A solid polymer electrolyte membrane;
Catalyst layers respectively formed on both surfaces excluding the outer peripheral edge of the electrolyte membrane;
A frame-shaped reinforcing sheet having an opening at the center, each installed on both surfaces of the electrolyte membrane-catalyst layer assembly comprising the electrolyte membrane and the catalyst layer,
Each of the reinforcing sheets adheres to the outer peripheral edge of the catalyst layer and the outer peripheral edge of the electrolyte membrane so that the catalyst layer is exposed from the opening except for the outer peripheral edge. Membrane-catalyst layer assembly. An electrolyte membrane-catalyst layer assembly with a reinforcing sheet according to claim 1,
A gas diffusion layer having a thickness equal to or greater than the thickness of the reinforcing sheet and formed on the catalyst layer exposed from the opening of the reinforcing sheet;
An electrolyte membrane-electrode assembly with a reinforcing sheet, comprising: A solid polymer electrolyte membrane;
Catalyst layers respectively formed on both sides except the outer peripheral edge of the electrolyte membrane;
A gas diffusion layer formed on each of the catalyst layers;
A frame-shaped reinforcing sheet having an opening in the center, installed on both surfaces of the electrolyte membrane-electrode assembly comprising the electrolyte membrane, the catalyst layer, and the gas diffusion layer, and
Each reinforcing sheet is adhered to the outer peripheral edge of the gas diffusion layer and the outer peripheral edge of the electrolyte membrane so that the gas diffusion layer is exposed from the opening except the outer peripheral edge .
The reinforcing sheet is an electrolyte membrane-electrode assembly with a reinforcing sheet in which outer peripheral edges protruding from the electrolyte membrane are adhered to each other .   4. The reinforcing sheet according to claim 2, wherein each reinforcing sheet includes an adhesive layer that adheres to the electrolyte membrane-electrode assembly, and a gas barrier layer that prevents permeation of fuel gas and oxidant gas. 5. Electrolyte membrane-electrode assembly.   Each said reinforcement sheet is with the reinforcement sheet in any one of Claims 1-4 adhere | attached with the material containing at least any one of an acrylic adhesive material, a rubber-type adhesive material, and a silicone type adhesive material. Electrolyte membrane-electrode assembly. The electrolyte membrane-catalyst layer assembly with a reinforcing sheet according to claim 1 or 2 , wherein the reinforcing sheets are adhered to each other at outer peripheral edges protruding from the electrolyte membrane.   The electrolyte membrane-electrode assembly with a reinforcing sheet according to claim 2, wherein an outer peripheral edge of the gas diffusion layer and an inner peripheral edge of the reinforcing sheet are separated from each other.   The electrolyte membrane-electrode assembly with a reinforcing sheet according to claim 7, wherein a distance from an outer peripheral edge of the gas diffusion layer to an inner peripheral edge of the reinforcing sheet is greater than 0 mm and 5 mm or less. An electrolyte membrane-electrode assembly with a reinforcing sheet according to any one of claims 2 to 8,
Gaskets installed on the respective reinforcing sheets so as to surround each electrode composed of the catalyst layer and the gas diffusion layer, and
Separators respectively installed on the electrodes and gaskets;
A solid polymer fuel cell comprising: A solid polymer electrolyte membrane; a catalyst layer formed on each side except for an outer peripheral edge of the electrolyte membrane; a gas diffusion layer formed on each catalyst layer; and the electrolyte membrane, catalyst layer, and gas A frame-shaped reinforcing sheet having an opening in the center, which is installed on both surfaces of the electrolyte membrane-electrode assembly comprising a diffusion layer, and each of the reinforcing sheets has the gas diffusion layer outside the opening. An electrolyte membrane-electrode assembly with a reinforcing sheet that adheres to the outer peripheral edge of the gas diffusion layer and the outer peripheral edge of the electrolyte membrane so as to be exposed except for the peripheral edge,
Gaskets installed on the respective reinforcing sheets so as to surround each electrode composed of the catalyst layer and the gas diffusion layer, and
Separators respectively installed on the electrodes and gaskets;
A solid polymer fuel cell comprising: A step of preparing a solid polymer electrolyte membrane;
Forming a catalyst layer on both surfaces excluding the outer peripheral edge of the electrolyte membrane;
Installing a frame-shaped reinforcing sheet having an opening at the center on the upper and lower surfaces of the electrolyte membrane-catalyst layer assembly comprising the electrolyte membrane and the catalyst layer;
A step of adhering each reinforcing sheet onto the outer peripheral edge of the catalyst layer and the outer peripheral edge of the electrolyte membrane so that the catalyst layer is exposed from the opening except for the outer peripheral edge. A method for producing an electrolyte membrane-catalyst layer assembly. A step of preparing a solid polymer electrolyte membrane;
Forming a catalyst layer on both surfaces excluding the outer peripheral edge of the electrolyte membrane;
Forming a gas diffusion layer on each catalyst layer;
A step of installing a frame-shaped reinforcing sheet having an opening in the center on both surfaces of the electrolyte membrane-electrode assembly comprising the electrolyte membrane, the catalyst layer, and the gas diffusion layer;
Said that from said opening the gas diffusion layer is exposed except the outer peripheral edge portion, possess a step to adhere the respective reinforcing sheet on the outer peripheral edge portion of the outer peripheral edge portion and the electrolyte membrane of the gas diffusion layer,
The reinforcing sheet is a method for producing an electrolyte membrane-catalyst layer assembly with a reinforcing sheet in which outer peripheral edges protruding from the electrolyte membrane are adhered to each other .   The method for producing an electrolyte membrane-catalyst layer assembly with a reinforcing sheet according to claim 11 or 12, wherein in the step of adhering, the reinforcing sheet is pressure-bonded at a pressure of 0.1 to 0.3 MPa.