JP5533134B2 - Catalyst layer-electrolyte membrane laminate, catalyst layer with edge seal-electrolyte membrane laminate, membrane-electrode assembly, membrane-electrode assembly with edge seal, and production method thereof - Google Patents

Description

  The present invention relates to a catalyst layer-electrolyte membrane laminate, a catalyst layer-electrolyte membrane laminate with an edge seal, a membrane-electrode assembly, a membrane-electrode assembly with an edge seal, and methods for producing them.

  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, polymer electrolyte fuel cells have a low operating temperature, low electrolyte resistance, and use a highly active catalyst, so they can achieve high output even in small sizes, and can be used for household cogeneration systems, etc. As soon as practical use is expected.

  Since it is time-consuming and inefficient to manufacture each polymer electrolyte fuel cell individually, it is generally manufactured by the following manufacturing method when mass-produced. That is, first, a large electrolyte membrane is prepared, and a large catalyst layer is arranged on both sides of the large electrolyte membrane to produce a large catalyst layer-electrolyte membrane laminate. Then, the large catalyst layer-electrolyte membrane laminate is cut into a desired size to produce a plurality of catalyst layer-electrolyte membrane laminates (see, for example, paragraph “0014” of Patent Document 1).

JP 2004-47230 A

  In the method described above, the cut portion becomes the outer peripheral surface of the catalyst layer-electrolyte membrane laminate. As shown in FIG. 16, the outer peripheral surface is flush with the end surfaces of the electrolyte membrane 2 and the catalyst layer 3. It has become. For this reason, there exists a problem that the catalyst layers 3 arrange | positioned at the both sides of the electrolyte membrane 2 may contact and short-circuit.

  Therefore, the present invention provides a catalyst layer-electrolyte membrane laminate, an edge-sealed catalyst layer-electrolyte membrane laminate, a membrane-electrode assembly, an edge-sealed membrane-electrode assembly, and production thereof. It is an object to provide a method.

  The catalyst layer-electrolyte membrane laminate according to the present invention includes an electrolyte membrane and catalyst layers disposed on both sides of the electrolyte membrane, and at least one outer peripheral surface of each catalyst in the plan view of the electrolyte membrane. The catalyst layers are inclined toward the electrolyte membrane so as to be larger than the layers.

  According to this configuration, since the outer peripheral surface of the catalyst layer-electrolyte membrane laminate is inclined so that the electrolyte membrane is larger than the catalyst layer in plan view, the electrolyte membrane sandwiched between the catalyst layers is most outward. It has a protruding shape. The electrolyte membrane prevents the catalyst layers from coming into contact with each other, thereby preventing a short circuit.

  The 1st membrane-electrode assembly which concerns on this invention is equipped with the catalyst layer-electrolyte membrane laminated body mentioned above, and the electroconductive porous base material arrange | positioned on each said catalyst layer. Since this membrane-electrode assembly includes the catalyst layer-electrolyte membrane laminate described above, it is possible to prevent the catalyst layers from contacting each other by the electrolyte membrane, and thus to prevent a short circuit.

  The catalyst layer with an edge seal-electrolyte membrane laminate according to the present invention has the catalyst layer-electrolyte membrane laminate described above, and the catalyst layer- having an opening in the center so that the catalyst layer is exposed from the opening. An edge seal adhered to at least one surface of the electrolyte membrane laminate. Since the catalyst layer-electrolyte membrane laminate with the edge seal similarly includes the catalyst layer-electrolyte membrane laminate described above, the catalyst membrane can prevent the catalyst layers from contacting each other, thereby preventing a short circuit. can do.

  A first membrane-electrode assembly with an edge seal according to the present invention comprises the above catalyst layer with an edge seal-electrolyte membrane laminate, and a conductive porous substrate disposed on each of the catalyst layers. Yes. Since this membrane-electrode assembly with edge seal is also provided with the above-described catalyst layer-electrolyte membrane laminate, it is possible to prevent the catalyst layers from contacting each other by the electrolyte membrane, thereby preventing a short circuit. Can do.

  A second membrane-electrode assembly according to the present invention includes an electrolyte membrane, a catalyst layer disposed on both surfaces of the electrolyte membrane, and a conductive porous substrate disposed on each catalyst layer. The at least one outer peripheral surface is inclined from each catalyst layer toward the electrolyte membrane so that the electrolyte membrane is larger than each catalyst layer and each conductive porous substrate in plan view.

  According to this configuration, since the outer peripheral surface of the membrane-electrode assembly is inclined so that the electrolyte membrane is larger than the catalyst layer and the conductive porous substrate in plan view, the catalyst layer and the conductive porous substrate. The electrolyte membrane sandwiched between the electrodes is made to protrude outward most. The electrolyte membrane prevents the electrodes from coming into contact with each other, thereby preventing a short circuit.

  The second membrane-electrode assembly with an edge seal according to the present invention has an opening at the center of the second membrane-electrode assembly, and the conductive porous substrate is exposed from the opening. And an edge seal adhered to at least one surface of the membrane-electrode assembly. Since this second membrane-electrode assembly with edge seal is provided with the second membrane-electrode assembly, the electrolyte membrane prevents the electrodes from coming into contact with each other, thereby preventing a short circuit. Can do.

  The method for producing a catalyst layer-electrolyte membrane laminate according to the present invention includes a step of preparing an electrolyte membrane, a step of arranging a catalyst layer on both surfaces of the electrolyte membrane, and the catalyst layer comprising the electrolyte membrane and the catalyst layer. Cutting the outer periphery of the electrolyte membrane laminate, and the outer peripheral surface of the catalyst layer-electrolyte membrane laminate cut in the cutting step is larger than the catalyst layers in plan view. Inclined from each catalyst layer toward the electrolyte membrane.

  In this manufacturing method, the outer periphery of the catalyst layer-electrolyte membrane laminate is inclined, and the outer periphery of the catalyst layer-electrolyte membrane laminate is formed so that the electrolyte membrane has a shape protruding outward from each catalyst layer in plan view. Since it cut | disconnects, it is prevented that catalyst layers contact, and by extension, a short circuit can be prevented.

  The method for producing a membrane-electrode assembly according to the present invention includes a step of preparing an electrolyte membrane, a step of arranging a catalyst layer on both surfaces of the electrolyte membrane, and a conductive porous substrate on each of the catalyst layers. Cutting the outer periphery of the membrane-electrode assembly comprising the electrolyte membrane, the catalyst layer, and the conductive porous substrate, and the membrane-electrode assembly cut in the cutting step. The outer peripheral surface is inclined from each catalyst layer toward the electrolyte membrane so that the electrolyte membrane is larger than each catalyst layer and each conductive porous substrate in plan view.

  In this manufacturing method, the membrane-electrode assembly is so shaped that the outer peripheral surface of the membrane-electrode assembly is inclined and the electrolyte membrane protrudes outward from the catalyst layers and the conductive porous substrate in plan view. Since the outer periphery of the body is cut, contact between the electrodes composed of the catalyst layer and the conductive porous substrate can be prevented, and as a result, a short circuit can be prevented.

  According to the present invention, a catalyst layer-electrolyte membrane laminate, an edge-sealed catalyst layer-electrolyte membrane laminate, a membrane-electrode assembly, an edge-sealed membrane-electrode assembly, and these that can prevent a short circuit A manufacturing method can be provided.

FIG. 1 is a front sectional view of a polymer electrolyte fuel cell according to this embodiment. FIG. 2 is a front sectional view of the membrane-electrode assembly according to the present embodiment. FIG. 3 is a plan view of the membrane-electrode assembly according to this embodiment. FIG. 4 is a plan view of the membrane-electrode assembly with edge seal according to the present embodiment. FIG. 5 is a schematic view showing a manufacturing process of the catalyst layer-electrolyte membrane laminate according to this embodiment. 6 is a cross-sectional view along line AA in FIG. 5 (a) and a cross-sectional view along line BB in FIG. 5 (b). 7 is a cross-sectional view taken along the line CC of FIG. 5 (a) and a cross-sectional view taken along the line DD. FIG. 8 is an explanatory view showing a method for producing a catalyst layer-electrolyte membrane laminate with an edge seal according to this embodiment. FIG. 9 is a front sectional view of a polymer electrolyte fuel cell according to another embodiment. FIG. 10 is a front sectional view of a polymer electrolyte fuel cell according to another embodiment. FIG. 11 is a schematic view showing a production process of a catalyst layer-electrolyte membrane laminate according to another embodiment. FIG. 12 is a plan view showing a manufacturing process of a catalyst layer-electrolyte membrane laminate according to another embodiment. FIG. 13 is a front sectional view showing a manufacturing process of a catalyst layer-electrolyte membrane laminate according to another embodiment. FIG. 14 is a front sectional view showing a method for cutting out a catalyst layer-electrolyte membrane laminate according to another embodiment. FIG. 15 is a front sectional view showing a manufacturing process of a catalyst layer-electrolyte membrane laminate according to another embodiment. FIG. 16 is a front sectional view showing a conventional catalyst layer-electrolyte membrane laminate. FIG. 17 is a front sectional view showing Comparative Example 2.

  Hereinafter, embodiments of a polymer electrolyte fuel cell according to the present invention will be described with reference to the drawings.

  As shown in FIG. 1, a polymer electrolyte fuel cell 1 according to this embodiment includes a catalyst layer-electrolyte membrane laminate 10 composed of an electrolyte membrane 2 and a catalyst layer 3, and the catalyst layer-electrolyte membrane laminate 10. It is mainly comprised from the electroconductive porous base material 4 arrange | positioned on both surfaces. The polymer electrolyte fuel cell 1 also includes an edge seal 5 extending outward from the catalyst layer-electrolyte membrane laminate 10, a gasket 6 installed on the edge seal 5, and a separator 7. I have. A structure in which the conductive porous substrate 4 is disposed on both surfaces of the catalyst layer-electrolyte membrane laminate 10 is referred to as a membrane-electrode assembly 20. The catalyst layer-electrolyte membrane laminate 10 having the edge seal 5 bonded thereto corresponds to the catalyst layer-electrolyte membrane laminate with edge seal of the present invention.

  As shown in FIGS. 2 and 3, the electrolyte membrane 2 has a rectangular shape in plan view, and the catalyst layers 3 are respectively disposed on both sides thereof. A structure in which the catalyst layer 3 is disposed on both surfaces of the electrolyte membrane 2 is referred to as a catalyst layer-electrolyte membrane laminate 10. The catalyst layer-electrolyte membrane laminate 10 has four outer peripheral surfaces 101 because of its rectangular shape, and the four outer peripheral surfaces 101 are inclined so as to spread from each catalyst layer 3 toward the electrolyte membrane 2. The cross-sectional shape is <character shape. For this reason, the area of the electrolyte membrane 2 in plan view is the largest. The inclination angle α of the outer peripheral surface 101 is not particularly limited, but is preferably about 10 to 65 degrees. Although these are not particularly limited, the thickness of the electrolyte membrane 2 is preferably about 0.01 to 0.2 mm, and the thickness of the catalyst layer 3 is about 2 to 100 μm. preferable.

  The conductive porous substrate 4 is disposed on each catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10. The conductive porous substrate 4 is not particularly limited, but the thickness is preferably about 0.1 to 0.5 mm. The conductive porous substrate 4 and the catalyst layer 3 constitute an electrode.

  As shown in FIGS. 1 and 4, the edge seal 5 is slightly larger than the catalyst layer-electrolyte membrane laminate 10 and is formed in a frame shape having an opening 51 at the center. The edge seal 5 is adhered to both surfaces of the catalyst layer-electrolyte membrane laminate 10, and the conductive porous substrate 4 described above is laminated on the catalyst layer 3 exposed from the opening 51 in this state. The edge seal 5 preferably has a two-layer structure in which the side that adheres to the catalyst layer-electrolyte membrane laminate 10 is an adhesive layer, and a gas barrier layer is formed on the adhesive layer. Although not particularly limited, the thickness of the edge seal 5 is about 0.02 to 0.5 mm, the thickness of the adhesive layer is about 0.01 to 0.4 mm, and the thickness of the gas barrier layer is About 0.01 to 0.3 mm.

  As shown in FIG. 1, the gasket 6 is formed in a frame shape, and is installed on each edge seal 5 so as not to leak the fuel gas and the oxidant gas supplied to each electrode to the outside. The separator 7 is installed on the conductive porous substrate 4 and the gasket 6, and the region where the gas flow path 71 is formed is in a state of facing the conductive porous substrate 4.

  Next, the material of each member constituting the above-described polymer electrolyte fuel cell 1 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 to the hydrogen ion conductive polymer electrolyte membrane, an anion conductive solid polymer electrolyte membrane and a liquid substance-impregnated membrane are also included. Examples of the anion conductive electrolyte membrane include a hydrocarbon resin or a fluorine resin, and specific examples of the hydrocarbon resin include Aciplex (registered trademark) A201, 2111, 221 manufactured by Asahi Kasei Corporation, and Tokuyama. Neocepta (registered trademark) AM-1, AHA, etc. manufactured by Co., Ltd. may be mentioned, and examples of the fluorine-based resin may include Tosflex (registered trademark) IE-SF34 manufactured by Tosoh Corporation. Examples of the liquid substance-impregnated film include polybenzimidazole (PBI).

  The catalyst layer 3 can be a known platinum-containing catalyst layer (cathode catalyst and anode catalyst). Specifically, it contains carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte. As the hydrogen ion conductive polymer electrolyte, the same material as that used for the electrolyte membrane 2 described above can be used.

  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.

  The carbon particles are not limited as long as they have electrical conductivity, and known or commercially available carbon particles can be widely used. For example, carbon black, graphite, activated carbon, or the like can be used alone or in combination. Examples of carbon black include channel black, furnace black, ketjen black, acetylene black, and lamp black. The arithmetic average particle diameter of the carbon particles is usually about 5 nm to 200 nm, preferably about 20 to 80 nm. The average particle size of the carbon particles can be measured by, for example, a particle size distribution measuring device LA-920: manufactured by Horiba, Ltd.

  The conductive porous substrate 4 is well-known and can use various conductive porous substrates constituting the fuel electrode and the air electrode, and efficiently supplies fuel gas and oxidant gas as fuel to the catalyst layer. Therefore, it consists of a porous conductive substrate. Examples of the porous conductive substrate include carbon paper and carbon cloth.

  The edge seal 5 is not limited as long as it is a material that can be joined to the electrode member by a method such as thermocompression bonding, and is preferably made of an olefin resin such as a fluorine resin, a polyamide resin, a polyimide resin, polypropylene, polyethylene, or a polyester. Furthermore, when the edge seal is composed of two layers of an adhesive layer and a gas barrier layer, the gas barrier layer is made of polyester, polyamide, polyimide, polymethyl tempene, polyphenylene having barrier properties against water vapor, water, fuel gas and oxidant gas. 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, and polybutylene naphthalate.

  The adhesive layer is preferably made of a material that adheres to the electrolyte membrane due to its own tackiness or is welded to the catalyst layer-electrolyte membrane laminate 10 when heated. Such a material is preferably a polyolefin resin, for example, medium density polyethylene, high density polyethylene, linear low density polyethylene, ethylene-α-olefin copolymer, polypropylene, polybutene, polyisobutene, poeisobutylene, polybutadiene, polybutadiene, and the like. Copolymers of ethylene and unsaturated carboxylic acid such as isoprene, ethylene-methacrylic acid copolymer, or ethylene-acrylic acid copolymer, ethylene-ethyl acrylate copolymer, ionomer resin, ethylene-vinyl acetate copolymer Coalescence etc. can be used. In addition, acid-modified polyolefin resins and silane-modified polyolefin resins modified with them can be used. Among them, it is insulating to use polypropylene modified with unsaturated carboxylic acid or polyethylene modified with unsaturated carboxylic acid. Or it is preferable in terms of heat resistance.

  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 having a gas flow path is used. In addition, the separator 7 is made of a metal such as stainless steel, and a film made of a conductive material such as chromium, a platinum group metal or oxide thereof, or a conductive polymer is formed on the surface of the metal. It is also possible to use the metal surface plated with a material such as silver, a platinum group composite oxide, or chromium nitride.

  Next, a manufacturing method of the above-described polymer electrolyte fuel cell 1 will be described.

  As shown in FIG. 5, first, a catalyst layer-electrolyte membrane laminate 10 ′ in which a catalyst layer is formed on both surfaces of a long electrolyte membrane is prepared in a roll shape. Various known methods can be adopted as a method for forming the catalyst layer on the electrolyte membrane. For example, the catalyst layer can be formed by applying a paste-like catalyst layer on the electrolyte membrane and drying it, or by screen printing. Or a transfer method using a catalyst layer transfer sheet in which a catalyst layer is formed on a release sheet.

  Next, the long catalyst layer-electrolyte membrane laminate 10 ′ is conveyed to the downstream side (right side in FIG. 5), and the edge portion in the width direction is cut so that the outer peripheral surface is inclined. More specifically, first, the first cutting blade 11 is fixed on both sides of the catalyst layer-electrolyte membrane laminate 10 ′, and the catalyst layer-electrolyte membrane laminate 10 ′ is cut first. By passing through the blade 11, both edge portions on the upper surface side of the catalyst layer-electrolyte membrane laminate 10 ′ are cut (see FIG. 6A). Subsequently, the catalyst layer-electrolyte membrane laminate 10 is passed through the second cutting blades 12 installed on both sides of the catalyst layer-electrolyte membrane laminate 10 ′ on the downstream side of the first cutting blade 11. 'Is cut at both edges on the lower surface side (FIG. 6B). In addition, each edge part cut | disconnected by each cutting blade 11 and 12 may be wound up in roll shape with a winding device (illustration omitted). In this way, the outer peripheral surface in the width direction of the catalyst layer-electrolyte membrane laminate 10 'is formed as an inclined surface.

  Subsequently, the long catalyst layer-electrolyte membrane laminate 10 ′ is cut in the length direction by the third cutting blade 13 to obtain a sheet-like catalyst layer-electrolyte membrane laminate 10. The outer peripheral surface in the length direction formed by cutting with the third cutting blade 13 is a straight inclined surface from the upper surface side to the lower surface side (see FIG. 7A). The catalyst layer-electrolyte membrane laminate 10 thus formed into a single sheet is further cut from the back surface side by the fourth cutting blade 14 so that the electrolyte membrane is maximized from the respective catalyst layers 3 in plan view. An inclined surface inclined toward the electrolyte membrane 2 is formed as an outer peripheral surface (FIG. 7B). As described above, the single-wafer catalyst layer-electrolyte membrane laminate 10 in which the cross-sectional shapes of the four outer peripheral surfaces are <-shaped is formed.

  The edge seals 5 are adhered to both surfaces of the above-described single-wafer catalyst layer-electrolyte membrane laminate 10 as follows. As shown in FIG. 8, first, two edge seals 5 having a two-layer structure of an adhesive layer and a gas barrier layer are prepared, and the remaining three sides are left in a state where the adhesive layers face each other and leave one side. Are glued together. As a result, an adhesive portion is formed in a U-shape, and a bag body having an open left side is obtained (FIG. 8A). Note that various known methods can be adopted as the bonding method. For example, high-frequency bonding, impulse bonding, iron bonding, ultrasonic bonding, or the like can be used.

  When the bag body is formed by the edge seal 5, an easy-removal region 52 is then formed at the center of each edge seal 5 constituting the bag body (FIG. 8B). The size of the easy removal region 52 is formed to be slightly smaller than that of the catalyst layer 3. Preferably, the size is such that all of the inclined surfaces of the catalyst layer 3 adhere to the edge seal 5. The easy-removal region 52 refers to a region that can be easily removed. For example, the easy-removable region 52 can be formed by making a perforation in the outer peripheral edge or making a cut while leaving only a part. Thus, the catalyst layer-electrolyte membrane laminated body 10 is inserted into the bag body in which the easy-removal region 52 is formed from the left side where it is not bonded, and is moved to a predetermined position (FIG. 8C). The predetermined position refers to a position where the central portion of the catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10 faces the easy removal region 52.

  After moving the catalyst layer-electrolyte membrane laminate 10 to a predetermined position, the perforation at the outer peripheral edge of the easy-removal region 52 is cut and the easy-removal regions 52 are removed from the edge seals 5, whereby the catalyst layer-electrolyte membrane The central portion of the catalyst layer 3 of the laminate 10 is exposed from the inside of each edge seal 5 (FIG. 8D). In this state, the remaining portion of the edge seal 5 that has not been bonded is bonded by a known method so that the adhesive layer of the edge seal 5 is bonded to the inclined surface 101 of the catalyst layer-electrolyte membrane laminate 10. At the same time, the edge seals 5 are bonded together. Thus, the edge-sealed catalyst layer-electrolyte membrane laminate is completed (FIG. 8E).

  On the catalyst layer 3 exposed from the opening of the catalyst layer-electrolyte membrane laminate with edge seal described above, the conductive porous substrate 4 is laminated by thermocompression bonding, and the membrane-electrode assembly with edge seal is formed. Make it. And the gasket 6 is arrange | positioned on the edge seal 5 so that the circumference | surroundings of the electrode which consists of the catalyst layer 3 and the electroconductive porous base material 4 may be enclosed. Subsequently, the separator 7 is disposed on the conductive porous substrate 4 and the gasket 6 so that the gas flow path 71 faces the conductive porous substrate 4. Finally, the polymer electrolyte fuel cell 1 is completed by sandwiching the membrane-electrode assembly with an edge seal with the separator 7 so that the conductive porous substrate 4 and the separator 7 are electrically connected.

  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 conductive porous substrate 4 is formed on the catalyst layer after the outer periphery of the catalyst layer-electrolyte membrane laminate 10 is cut to form the inclined surface, but as shown in FIG. In addition, after the membrane-electrode assembly 20 is formed, the outer periphery of the membrane-electrode assembly 20 can be cut. In this case, the cross-sectional shape of the outer peripheral surface of the membrane-electrode assembly 20 is <shaped, and a roll-shaped membrane-electrode is used instead of the roll-shaped catalyst layer-electrolyte membrane laminate 10 ′ in the above embodiment. The joined body 20 is used. Further, the edge seal 5 can be bonded to both surfaces of the membrane-electrode assembly 20 instead of the catalyst layer-electrolyte membrane laminate 10 by the same method as in the above embodiment. In addition, what adhered the edge seal 5 to the membrane-electrode assembly 20 corresponds to the membrane-electrode assembly with an edge seal of the present invention.

  Further, it is not necessary to cut all the outer peripheral surfaces of the catalyst layer-electrolyte membrane laminate 10 or the membrane-electrode assembly 20 so as to incline, and the end surfaces of the electrolyte membrane 2 and the catalyst layer 3 are formed as shown in FIG. Only a portion that is flush with the surface may be inclined. For example, as shown in FIG. 10, the portion where the electrolyte membrane 2 protrudes outward from the catalyst layer 3 may not be inclined.

  In the catalyst layer-electrolyte membrane laminate 10 of the above embodiment, the catalyst layers are formed on both surfaces of the long electrolyte membrane. However, as shown in FIG. The catalyst layer 3 may not be formed. In this case, the outer peripheral surface in the width direction does not need to be inclined because the electrolyte membrane 2 protrudes outward from the catalyst layer 3.

  Moreover, in the said embodiment, although the catalyst layer-electrolyte membrane laminated body 10 of the desired magnitude | size was cut out from the elongate catalyst layer-electrolyte membrane laminated body 10, as shown in FIG. It is also possible to cut out a catalyst layer having a desired size from the electrolyte membrane laminate 10 ″. In this case, for example, as shown in FIG. (FIG. 13 (a)), and then cut from the back surface with a cutting blade having an inclination angle (FIG. 13 (b)). As a method of cutting out the body 10, a flat punching provided with a cutting blade on a flat plate as shown in FIG. 14A or a cylindrical punching provided with a cutting blade on a cylindrical member as shown in FIG. Examples of this cutting blade include , Spring blades, Thomson blades, engraving blades, corrosion blades, etc. In addition, the long catalyst layer-electrolyte membrane laminate conveyed to the downstream side of the above embodiment is similarly cut by a cutting blade. After cutting so as to punch from the front surface, it can also be cut so as to punch from the back surface.

  As shown in FIG. 15, first, the catalyst layer-electrolyte membrane laminate 10 is cut halfway by cutting or the like to make a cut (FIG. 15 (a)), and then cut from the back side by a cutting blade. (FIG. 15B).

  In addition, the long catalyst layer-electrolyte membrane laminate 10 ′ can be cut into single sheets in a state where the long catalyst layer-electrolyte membrane laminate 10 ′ is stuck on the support sheet. In this case, first, the edge part of the width direction is cut | disconnected with the 1st and 2nd cutting blades 11 and 12 similarly to the said embodiment. Next, only the catalyst layer-electrolyte membrane laminate 10 ′ is cut without cutting the support sheet with the third cutting blade 13. Then, the catalyst layer-electrolyte membrane laminate 10 ′ is cut into a sheet-like catalyst layer-electrolyte membrane laminate 10 by the next fourth cutting blade 14 while maintaining the long state. The support sheet remaining on the catalyst layer-electrolyte membrane laminate 10 may be peeled off before use, and is effective because it protects the catalyst layer-electrolyte membrane laminate immediately before use.

  EXAMPLES Hereinafter, the present invention will be described more specifically with reference to examples, but the present invention is not limited to these examples.

Example 1
As the electrolyte membrane 2, NRE212CS (manufactured by Dupont) having a film thickness of 53 μm cut to a size of 53.5 × 53.5 mm was used.

  Next, a transfer sheet for forming a catalyst layer was prepared as follows. First, 2 g of platinum catalyst-supported carbon (platinum support amount: 45.7 wt%, manufactured by Tanaka Kikinzoku Co., Ltd., TEC10E50E), 1-butanol 10 g, 3-butanol 10 g, fluororesin (5 wt% Nafion binder, manufactured by DuPont) 20 g and 6 g of water was added, and these were stirred and mixed with a disperser to prepare a catalyst paste. Then, a polyester film (X44, film thickness 25 μm) was prepared as a transfer substrate, and the catalyst paste was applied onto the transfer substrate.

  The transfer sheet for forming a catalyst layer produced as described above was cut into a size of 53 × 53 mm, and placed on both surfaces of the electrolyte membrane 2 so that the catalyst layer 3 faced the electrolyte membrane 3 side. And the catalyst layer 3 was formed in both surfaces of the electrolyte membrane 2 by heat-pressing on conditions of 135 degreeC, 5.0 Mpa, and 150 second, and the catalyst layer-electrolyte membrane laminated body 10 was produced. The catalyst layer 3 has a thickness of 20 μm.

  The outer periphery of the catalyst layer-electrolyte membrane laminate 10 produced as described above was cut as follows by the method shown in FIG. First, a cutting blade is applied to 0.5 mm inside the end of the catalyst layer 3 of the catalyst layer-electrolyte membrane laminate 10, and the catalyst layer-electrolyte membrane laminate so that the inclination angle α of the outer peripheral surface is 15 degrees therefrom. Ten perimeters were cut. Subsequently, the catalyst layer-electrolyte membrane laminate 10 is turned over, and a cutting blade is applied to a 0.5 mm portion inside the end of the catalyst layer 3 in the same manner as the surface, and the inclination angle α of the outer peripheral surface is 15 degrees from there. The catalyst layer-electrolyte membrane laminate 10 as shown in FIG. 13B was produced.

  Subsequently, an edge seal 5 was produced. Unsaturated carboxylic acid graft-modified polypropylene melted on a biaxially centrifuge polyethylene naphthalate (Teijin, Teonex, film thickness 12 μm), which is a gas barrier layer, is extruded at a thickness of 50 μm by a melt extrusion method to form an adhesive layer. Formed. Then, it cut | disconnected to the magnitude | size of 80x80 mm, and the opening part 51 of a magnitude | size of 50x50 mm was formed in the center part. The edge seal 5 is centered on both sides of the catalyst layer-electrolyte membrane laminate 10 and hot pressed under the conditions of 100 ° C., 1.0 MPa, 30 seconds, so that the edge seal 5 is catalyst layer-electrolyte membrane laminate. 10 was attached to produce a catalyst layer-electrolyte membrane laminate with an edge seal.

  Subsequently, carbon paper (TGP-, manufactured by Toray Industries, Inc.) cut as a conductive porous substrate 4 on the catalyst layer 3 exposed from the opening 51 of the edge seal 5 as the conductive porous substrate 4. H-090, 280 μm thick) was laminated to form a membrane-electrode assembly with an edge seal.

(Comparative Example 1)
A membrane-electrode assembly with an edge seal was prepared in the same manner as in Example 1 except that the inclination angle of the outer peripheral surface of the catalyst layer-electrolyte membrane laminate 10 was different. The catalyst layer-electrolyte membrane laminate of Comparative Example 1 has an inclination angle α of the outer peripheral surface of 90 degrees, that is, a shape in which the outer peripheral surface is not inclined as shown in FIG.

(Comparative Example 2)
In Example 1, after cutting from the surface of the catalyst layer-electrolyte membrane laminate, cutting is also performed from the back surface of the catalyst layer-electrolyte membrane laminate. In Comparative Example 2, the catalyst layer-electrolyte membrane laminate is cut. Cutting was done only from the front side of the body, and not from the back side. In other respects, a membrane-electrode assembly with an edge seal was produced in the same manner as in Example 1. As shown in FIG. 17, the catalyst layer-electrolyte membrane laminate of Comparative Example 2 is inclined so that the catalyst layer 3 on the lower surface side has the largest shape.

(Evaluation method)
Gaskets and separators were installed on the membrane-electrode assemblies with edge seals of Example 1 and Comparative Examples 1 and 2 to produce 50 polymer electrolyte fuel cells. And the terminal of the low resistance meter (Tsuruga Electric Co., Ltd. MODEL 356E) was attached to both electrodes of the membrane-electrode assembly with an edge seal, and resistance was measured. As a result, in Example 1, there was no short circuit between the electrodes in all the membrane-electrode assemblies. However, a short circuit between the electrodes occurred in the membrane-electrode assembly of Comparative Example 1 and 4 of Comparative Example 2.

2 Electrolyte membrane 3 Catalyst layer 4 Conductive porous substrate 5 Edge seal 51 Opening 10 Catalyst layer-electrolyte membrane laminate 20 Membrane-electrode assembly

Claims (10)

An electrolyte membrane;
A catalyst layer-electrolyte membrane laminate comprising a catalyst layer disposed on both surfaces of the electrolyte membrane ,
At least one outer peripheral surface of the catalyst layer-electrolyte membrane laminate is inclined from each catalyst layer toward the electrolyte membrane so that the electrolyte membrane is larger than each catalyst layer in plan view, and a cross section thereof. A catalyst layer-electrolyte membrane laminate having a <character shape . The catalyst layer-electrolyte membrane laminate according to claim 1,
A conductive porous substrate disposed on each of the catalyst layers;
A membrane-electrode assembly comprising: A catalyst layer-electrolyte membrane laminate comprising an electrolyte membrane and catalyst layers disposed on both sides of the electrolyte membrane, wherein at least one outer peripheral surface of the catalyst layer-electrolyte membrane laminate is the electrolyte membrane Is inclined from each catalyst layer toward the electrolyte membrane so as to be larger than each catalyst layer in plan view, and a catalyst layer-electrolyte membrane laminate,
An edge seal bonded to the outer peripheral surface of at least one surface of the catalyst layer-electrolyte membrane laminate so as to have an opening in the center and to expose the catalyst layer from the opening;
The catalyst layer-electrolyte membrane laminated body with an edge seal | sticker provided with. The catalyst layer-electrolyte membrane laminate with an edge seal according to claim 3,
A conductive porous substrate disposed on each of the catalyst layers;
A membrane-electrode assembly with an edge seal, comprising: An electrolyte membrane;
A catalyst layer disposed on both surfaces of the electrolyte membrane;
A conductive porous substrate disposed on each catalyst layer, and a membrane-electrode assembly comprising:
At least one outer peripheral surface of the membrane-electrode assembly has an end portion of the electrolyte membrane from each catalyst layer such that the electrolyte membrane is larger than each catalyst layer and each conductive porous substrate in plan view. Membrane-electrode assembly that is inclined toward. The membrane-electrode assembly according to claim 5, wherein the cross-sectional shape of at least one outer peripheral surface of the membrane-electrode assembly is <-shaped. The membrane-electrode assembly according to claim 5 or 6 ,
An edge seal that has an opening in the center and is adhered to at least one surface of the membrane-electrode assembly so that the conductive porous substrate is exposed from the opening;
A membrane-electrode assembly with an edge seal, comprising: A step of preparing an electrolyte membrane;
Disposing a catalyst layer on both surfaces of the electrolyte membrane;
Cutting the outer periphery of the catalyst layer-electrolyte membrane laminate comprising the electrolyte membrane and the catalyst layer,
The outer peripheral surface of the catalyst layer-electrolyte membrane laminate cut in the cutting step is inclined from each catalyst layer toward the electrolyte membrane so that the electrolyte membrane is larger than each catalyst layer in plan view. The method for producing a catalyst layer-electrolyte membrane laminate , wherein the cross-sectional shape is <character shape . A step of preparing an electrolyte membrane;
Disposing a catalyst layer on both surfaces of the electrolyte membrane;
Disposing a conductive porous substrate on each catalyst layer;
Cutting the outer periphery of the membrane-electrode assembly comprising the electrolyte membrane, the catalyst layer, and the conductive porous substrate,
The outer peripheral surface of the membrane-electrode assembly cut in the cutting step is from the catalyst layer to the electrolyte so that the electrolyte membrane is larger than the catalyst layer and the conductive porous substrate in plan view. The manufacturing method of the membrane-electrode assembly which inclines toward the edge part of a film | membrane. The method for producing a membrane-electrode assembly according to claim 9, wherein a cross-sectional shape of the outer peripheral surface of the membrane-electrode assembly is <-shaped.

Images