JP6485178B2 - Method for producing a single fuel cell - Google Patents

Description

  The present invention relates to a method for manufacturing a fuel cell single cell.

  A membrane electrode assembly having electrode catalyst layers formed on both sides of the electrolyte membrane; a first gas diffusion layer disposed on one side of the membrane electrode assembly; and a membrane electrode assembly disposed on the other side of the membrane electrode assembly. A fuel cell single cell manufacturing method comprising the second gas diffusion layer and a support frame that supports the membrane electrode assembly on the outer periphery of the membrane electrode assembly, the outer periphery of the other side surface of the membrane electrode assembly Forming a thermoplastic adhesive layer on the part, disposing a first gas diffusion layer on one side of the membrane electrode assembly, and second gas diffusion on the other side of the membrane electrode assembly A step of disposing a layer, the step of disposing the peripheral portion of the second gas diffusion layer so as to overlap the inner portion of the adhesive layer, and the first gas diffusion layer, the membrane electrode assembly, and the adhesive layer. Integrating the inner part and the second gas diffusion layer by thermocompression bonding and supporting on the outer part of the adhesive layer; There is known a method of manufacturing a fuel cell single cell including a step of disposing an inner portion of a frame and a step of thermocompression-bonding a support frame, an outer portion of an adhesive layer, and a membrane electrode assembly ( For example, see Patent Document 1).

JP 2014-029834 A

  In Patent Document 1, the outer peripheral edge of the other side surface of the membrane electrode assembly is covered with a thermoplastic adhesive layer and is not exposed to the gas atmosphere of a single fuel cell. Therefore, it is possible to avoid the occurrence of cracks that can occur when the outer peripheral edge is exposed to a gas atmosphere. However, the support frame made of resin may be deformed by heating necessary when the thermoplastic adhesive layer is used. Therefore, the inventors have now examined the use of an adhesive that is cured by ultraviolet rays, that is, an adhesive having ultraviolet curing properties, as the adhesive layer. However, the material for forming the gas diffusion layer generally does not have ultraviolet transparency. Therefore, when an ultraviolet curable adhesive is used, it is necessary to cure the adhesive before disposing the gas diffusion layer on the membrane electrode assembly. That is, an adhesive is applied on the outer peripheral edge of the membrane electrode assembly to form an adhesive layer, the inner part of the support frame is disposed on the outer part of the adhesive layer, and then the second gas diffusion layer Before disposing the second gas diffusion layer on the other side surface of the membrane electrode assembly so that the peripheral portion overlaps the inner portion of the adhesive layer, it is necessary to cure the adhesive layer with ultraviolet rays. However, in that case, when the second gas diffusion layer is arranged on the adhesive layer cured by ultraviolet rays, the peripheral portion of the second gas diffusion layer is held on the upper part of the inner side portion of the adhesive layer. Overlapping, the peripheral portion of the second gas diffusion layer rises as compared with other portions of the second gas diffusion layer. As a result, the flow path of the supply gas defined by the second gas diffusion layer and the separator thereon is blocked at the rising portion, or the fibers forming the second gas diffusion layer are fluffed at the rising portion. There is a possibility that the battery performance may be deteriorated due to a phenomenon such as excessive surface pressure being applied to the membrane electrode assembly under the adhesive layer. However, if the amount of adhesive applied on the outer peripheral edge of the membrane electrode assembly is reduced so that the adhesive layer does not reach under the gas diffusion layer, part of the outer peripheral edge of the membrane electrode assembly May be exposed to the gas atmosphere of the single fuel cell. The support frame, the gas diffusion layer, and the membrane electrode assembly can be reliably integrated without exposing the membrane electrode assembly, without deforming the support frame, and without applying excessive surface pressure to the membrane electrode assembly. A possible technology is desired.

  According to the present invention, the membrane electrode assembly in which the electrode catalyst layers are formed on both sides of the electrolyte membrane, the first gas diffusion layer disposed on one side surface of the membrane electrode assembly, and the membrane electrode junction A method for producing a fuel cell single cell, comprising: a second gas diffusion layer disposed on the other side of the body; and a support frame that supports the membrane electrode assembly on an outer periphery of the membrane electrode assembly, Preparing the membrane electrode assembly in which the first gas diffusion layer is disposed on one side surface and the second gas diffusion layer is not disposed on the other side surface; and the other of the membrane electrode assembly A step of forming a cationic polymerization type ultraviolet curable adhesive layer on the outer peripheral edge of the side surface, an inner portion of the support frame is disposed on an outer portion of the adhesive layer, and the adhesive layer is Adhesion to initiate photopolymerization but not cure completely A step of irradiating the layer with ultraviolet rays, and after irradiating the adhesive layer with ultraviolet rays, before the adhesive layer is completely cured, the second gas diffusion layer on the other side surface of the membrane electrode assembly And a step of arranging the peripheral portion of the second gas diffusion layer so as to overlap the inner portion of the adhesive layer.

  The support frame, the gas diffusion layer, and the membrane electrode assembly can be reliably integrated without exposing the membrane electrode assembly, without deforming the support frame, and without applying excessive surface pressure to the membrane electrode assembly. it can.

It is a fragmentary sectional view which shows the structural example of the fuel cell stack containing a fuel cell single cell. It is the elements on larger scale of FIG. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a graph which shows the irradiation conditions of an ultraviolet-ray. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the process of the manufacturing method of a fuel cell single cell. It is a fragmentary sectional view which shows the structural example of the fuel cell stack of a comparative example.

  FIG. 1 is a partial cross-sectional view showing a configuration example of a fuel cell stack A including a single fuel cell 1. Referring to FIG. 1, the fuel cell stack A is formed by a stacked body in which a plurality of fuel cell single cells 1 are stacked in the thickness direction S of the fuel cell single cell 1. The single fuel cell 1 generates electric power by an electrochemical reaction between a fuel gas (example: hydrogen gas) and an oxidant gas (example: air) supplied to the single fuel cell 1. The electric power generated in the single fuel cell 1 is supplied to the fuel cell stack via a plurality of wires (not shown) from the terminal plates (not shown) arranged at both ends of the stacked body to the outside of the fuel cell stack A. A is taken out of A. The electric power taken out from the fuel cell stack A is supplied to, for example, an electric motor for driving an electric vehicle or a capacitor.

  The fuel cell single cell 1 includes a membrane electrode assembly 5. The membrane electrode assembly 5 includes an electrolyte membrane 5e, and an anode electrode catalyst layer 5a and a cathode electrode catalyst layer 5c are formed on both sides of the electrolyte membrane 5e. The electrolyte membrane 5e, the anode electrode catalyst layer 5a, and the cathode electrode catalyst layer 5c have substantially the same size, and the anode electrode catalyst layer 5a and the cathode electrode catalyst layer 5c are disposed on both sides of the electrolyte membrane 5e, respectively. When the joined body 5 is formed, the electrolyte membrane 5e, the cathode electrode catalyst layer 5c, and the anode electrode catalyst layer 5a substantially overlap each other. In another example not shown, at least one of the anode electrode catalyst layer 5a and the cathode electrode catalyst layer 5c is smaller than the electrolyte membrane 5e.

  Examples of the material of the electrolyte membrane 5e include a fluorine-based polymer membrane having ion conductivity. In the embodiment shown in FIG. 1, an ion exchange membrane having proton conductivity including perfluorosulfonic acid is used. Examples of the material for the cathode electrode catalyst layer 5c and the anode electrode catalyst layer 5a include catalyst-supported carbon that supports a catalyst such as platinum or a platinum alloy. In the embodiment shown in FIG. 1, catalyst-carrying carbon carrying a platinum alloy is used. In another embodiment not shown, an ionomer made of the same material as the electrolyte membrane 5e is further added to the catalyst-supporting carbon.

  An anode gas diffusion layer (first gas diffusion layer) 3a is disposed on one side surface 51 of the membrane electrode assembly 5, that is, on the anode electrode catalyst layer 5a, so that the anode gas diffusion layer 3a becomes the membrane electrode assembly 5. Is electrically connected. Further, a cathode gas diffusion layer (second gas diffusion layer) 3c is disposed on the other side surface 52 of the membrane electrode assembly 5, that is, on the cathode electrode catalyst layer 5c. It is electrically connected to the body 5. Since the cathode gas diffusion layer 3c is slightly smaller than the membrane electrode assembly 5, when the cathode gas diffusion layer 3c is disposed on the other side surface 52 of the membrane electrode assembly 5, the other side surface around the cathode gas diffusion layer 3c is used. An outer peripheral edge 52e is formed in a frame shape at 52. On the other hand, the anode gas diffusion layer 3 a has substantially the same size as the membrane electrode assembly 5.

  Examples of the material for the cathode gas diffusion layer 3c and the anode gas diffusion layer 3a include conductive porous materials such as carbon porous materials such as carbon paper, carbon cloth, and glassy carbon, metal mesh, and foam metal. A metal porous body is mentioned. These materials are not UV transmissive. In the embodiment shown in FIG. 2, carbon cloth is used. In another embodiment (not shown), a material having high water repellency such as polytetrafluoroethylene is impregnated to such an extent that the porous body does not lose porosity. In still another embodiment (not shown), a water-repellent layer in which a material having strong water repellency and carbon particles are mixed is formed on the membrane electrode assembly 5 side of the porous body.

  An adhesive layer 10 is formed on the outer peripheral edge 52 e of the membrane electrode assembly 5. The adhesive layer 10 is formed in the same frame shape as the outer peripheral edge 52e so as to cover the outer peripheral edge 52e. In the embodiment shown in FIG. 1, the adhesive layer 10 is formed on the entire outer peripheral edge portion 52e.

  The adhesive layer 10 is formed of a cationic polymerization type ultraviolet (UV) curable adhesive. Examples of the material of the adhesive layer 10 include a UV curable adhesive using a cationic polymerizable resin, and examples of the cationic polymerizable resin include an epoxy resin, an oktacene resin, and a vinyl ether resin. In the embodiment shown in FIG. 1, a UV curable adhesive using an epoxy resin is used. Examples of the method of applying the adhesive for the adhesive layer 10 include a screen printing method and a method of applying with a dispenser. In the embodiment shown in FIG. 1, a screen printing method is used.

  In the cationic polymerization type ultraviolet curable adhesive used as the material of the adhesive layer 10, typically, curing is started by irradiating with ultraviolet rays so as to be cured in a short time by taking advantage of fast curing. The ultraviolet light is stopped after the end. On the other hand, the cationic polymerization type ultraviolet curable adhesive has delayed curable properties, and the delayed curable property is utilized in the adhesive layer 10 shown in FIG. That is, once the adhesive layer 10 is irradiated with ultraviolet rays and the adhesive layer 10 starts photopolymerization (cationic polymerization), that is, when curing is started, the ultraviolet rays are applied to the adhesive before the adhesive layer 10 is completely cured. Even if the layer 10 is not irradiated, the adhesive layer 10 continues cationic polymerization, and after a while, the adhesive layer 10 is completely cured. The time required for the adhesive layer 10 to be completely cured can be controlled by the ultraviolet irradiation conditions (illuminance, integrated light quantity (= illuminance × time)). Accordingly, when the adhesive layer 10 is irradiated with ultraviolet rays under appropriate irradiation conditions, the adhesive layer 10 is not completely cured for a while after the irradiation is completed, that is, the shape is held but with a small force. It will be in the state which has a certain amount of fluidity which can flow. Thereafter, the curing gradually proceeds, and after a lapse of time according to the irradiation conditions, the adhesive layer 10 is in a completely cured state, that is, a state where the curing is completed. However, the completely cured state is a state in which the polymerization reaction is stopped and the adhesive layer 10 has almost no fluidity.

  The support frame 2 is fixed on the adhesive layer 10. The support frame 2 has a frame shape and supports the membrane electrode assembly 5 on which the anode gas diffusion layer 3a and the cathode gas diffusion layer 3c are arranged on the outer periphery thereof. The support frame 2 includes a support frame main body 21 and a protrusion 22 that extends inward from the inner edge side of the support frame main body 21 and is thinner than the support frame main body 21. The protrusion 22 of the support frame 2 can be seen as a portion on the inner peripheral edge side of the support frame 2, that is, an inner peripheral edge. The protrusion 22 (inner peripheral edge) of the support frame 2 is bonded to the outer peripheral edge 52 e of the membrane electrode assembly 5 by the adhesive layer 10. When the protrusion 22 is joined to the outer peripheral edge 52e, a gap G is formed between the inner end of the protrusion 22 and the outer end of the cathode gas diffusion layer 3c. That is, the support frame 2 and the cathode gas diffusion layer 3c are separated from each other.

  Examples of the material of the support frame 2 include materials having electrical insulation and airtightness, such as polypropylene resins, phenol resins, epoxy resins, polyethylene terephthalate resins, and polyethylene naphthalate resins. . In the embodiment shown in FIG. 2, the material of the support frame 2 can transmit ultraviolet rays of a predetermined wavelength (predetermined wavelength region) irradiated from an ultraviolet light source (eg, metal halide lamp) used for curing the adhesive layer 10. Polypropylene resin is used.

  A pair of anode separator 4a and cathode separator 4c sandwiching the membrane electrode assembly 5 having the anode gas diffusion layer 3a and the cathode gas diffusion layer 3c and both sides of the support frame 2 are disposed. The anode separator 4a is fixed to the support frame main body 21 with another adhesive layer (not shown) at the peripheral portion 4ae, and abuts against the anode gas diffusion layer 3a at the central portion 4am. The central portion 4am is provided with a plurality of grooves for fuel gas supply paths extending in parallel with each other, and a plurality of fuel gas supply paths 32 are formed by these grooves and the anode gas diffusion layer 3a. The cathode separator 4c is fixed to the support frame body 21 with another adhesive layer (not shown) at the peripheral portion 4ce, and abuts against the cathode gas diffusion layer 3c at the central portion 4cm. In the central portion 4 cm, a plurality of grooves for oxidant gas supply paths extending in parallel with each other are provided, and a plurality of oxidant gas supply paths 31 are formed by these grooves and the cathode gas diffusion layer 3 c. In two adjacent fuel cell single cells 1, the cathode separator 4c of one fuel cell single cell 1 and the anode separator 4a of the other fuel cell single cell 1 are in contact with each other via a seal member (not shown). As a result, a cooling medium supply path 30 surrounded by two fuel gas supply paths 32 and two oxidant gas supply paths 31 is formed.

  The anode separator 4a and the cathode separator 4c are made of a conductive material that does not transmit fuel gas, oxidant gas, and cooling medium (for example, water). Examples of such a material include metals such as stainless steel and titanium. In the embodiment shown in FIG. 1, titanium is used as the material of the anode separator 4a and the cathode separator 4c.

  FIG. 2 is an enlarged partial cross-sectional view showing the vicinity of the adhesive layer 10 of FIG. As shown in the figure, the adhesive layer 10 includes an outer portion 11 located on the outer side in the planar direction of the outer peripheral edge 52e, an inner portion 13 located on the inner side in the planar direction of the outer peripheral edge 52e, and an outer portion. 11 and a central portion 12 between the inner portion 13. The inner portion 13 is absorbed inside the peripheral portion 3ce of the cathode gas diffusion layer 3c. The outer portion 11 is sandwiched between the protruding portion 22 of the support frame 2 and the membrane electrode assembly 5 and exists from the end 22g of the protruding portion 22 to the outer edge 3ag of the anode gas diffusion layer 3a. The joined body 5 is joined. The central portion 12 fills the gap G between the end 22g of the support frame 2 and the end 3cg of the cathode gas diffusion layer 3c. When the outer peripheral edge 52e of the gap G that is not covered by the cathode gas diffusion layer 3c or the protrusion 22 is covered with the adhesive layer 10, the outer peripheral edge 52e has no portion exposed to the outside. In another embodiment (not shown), the support frame 2 and the cathode gas diffusion layer 3c are brought close to each other, and the central portion 12 of the adhesive layer 10 is not substantially provided.

  Next, the manufacturing method of a fuel cell single cell is demonstrated. 3-10 is a fragmentary sectional view which shows each process of the manufacturing method of the fuel cell single cell 1. FIG.

  First, as shown in FIG. 3, the membrane electrode assembly 5 in which the anode gas diffusion layer 3a is disposed on one side surface 51 is prepared. The anode gas diffusion layer 3a and the membrane electrode assembly 5 are heated and compressed by, for example, a hot press process and bonded in advance.

  Next, as shown in FIG. 4, a cationic polymerization type ultraviolet curable adhesive layer 10 is formed on the outer peripheral edge portion 52 e of the other side surface 52 of the membrane electrode assembly 5. The adhesive layer 10 includes an outer portion 11 on the outer region of the outer peripheral edge portion 52e, an inner portion 13 on the inner region of the outer peripheral edge portion 52e, and a central portion 12 on the central region of the outer peripheral edge portion 52e. In the embodiment shown in FIG. 4, a UV curable adhesive using an epoxy resin is used as the adhesive layer 10. As a method for forming the adhesive layer 10, a method using screen printing is used.

  Subsequently, as shown in FIG. 5, the support frame 2 is placed on the outer periphery of the membrane electrode assembly 5 so that the inner portion (projecting portion 22) of the support frame 2 is disposed on the outer portion 11 of the adhesive layer 10. Deploy. At this time, since the protruding portion 22 is placed under a load from above, the adhesive of the outer portion 11 is crushed. As a result, the adhesive reaches the outer edge 3ag of the anode gas diffusion layer 3a in the outer direction of the membrane electrode assembly 5. Thereby, the adhesion area of the membrane electrode assembly 5 and the support frame 2 can be widened. Further, in the inner direction of the membrane electrode assembly 5, the adhesive covers the end 22 g of the protruding portion 22, and the inner portion 13 is pushed out in the inner direction. Thereby, an adhesive agent can be reliably arrange | positioned to the area | region where the peripheral part 3ce of the cathode gas diffusion layer 3c is arrange | positioned, and the outer peripheral part 52e of the membrane electrode assembly 5 can be covered reliably.

  Next, as shown in FIG. 6, the adhesive layer 10 is irradiated with ultraviolet rays. Specifically, ultraviolet rays UV are applied to the adhesive layer 10 so that the adhesive layer 10 starts photopolymerization but is not completely cured. Irradiation conditions of ultraviolet rays UV that initiate photopolymerization of the adhesive layer 10 but are not completely cured are determined in advance by experiments, for example.

FIG. 7 is an example of an experimental result showing the relationship between the irradiation condition of ultraviolet rays and the curing of the adhesive layer 10. As the adhesive layer 10, a UV curable adhesive using an epoxy resin was used, and as the ultraviolet light source, a metal halide lamp (for example, ultraviolet rays in a wavelength region of about 200 to 400 nm were widely radiated) was used. However, the vertical axis represents the illuminance of ultraviolet rays irradiated on the adhesive layer 10, and the horizontal axis represents the integrated light quantity of ultraviolet rays irradiated on the adhesive layer 10. In the example of this figure, the irradiation conditions shown in the region A in the figure were optimum as the irradiation conditions of the ultraviolet ray UV where the adhesive layer 10 starts photopolymerization but is not completely cured. That illuminance 270 mW / cm ² and cumulative light quantity 50 mJ / cm ^2, illuminance 168mW / cm ² and cumulative light quantity 224mJ / cm ^2, a region including the illumination 575mW / cm ² and cumulative light quantity 5 mJ / cm ^2. Under the irradiation conditions of the A region, the time required for curing is appropriate, and a necessary and sufficient time can be obtained for the post-process to be performed after the irradiation is completed until the curing is completed. However, under the irradiation conditions in the region B in the figure, the time required for curing is short, or the curing is completed during the irradiation. Therefore, the post-process to be performed after the irradiation is completed until the curing is completed. It is necessary to carry out, or a post process cannot be performed. Under the irradiation conditions in the region C in the figure, the time required for curing is long, and a waiting time occurs after the completion of the post-process that should be performed after the irradiation is completed until the curing is completed. Note that typical irradiation conditions for completing the curing during the irradiation are, for example, the irradiation conditions at the point B1 in the region B, that is, the illuminance 700 mW / cm ² and the integrated light amount 4500 mJ / cm ² .

  At this time, as the material of the support frame 2, a polypropylene-based resin capable of transmitting ultraviolet rays having a predetermined wavelength (predetermined wavelength range) irradiated from an ultraviolet light source (for example, a metal halide lamp) used for curing the adhesive layer 10 is used. Therefore, the ultraviolet rays UV can pass through the protrusion 22. As a result, the adhesive layer 10 starts to be irradiated with ultraviolet rays UV, and for a while after the irradiation is finished, the adhesive layer 10 is not completely cured and holds the shape, It becomes possible to flow with a small force. However, as the cationic polymerization gradually proceeds in the adhesive layer 10, the adhesive layer 10 is cured over time, and the protrusion 22 and the outer peripheral edge 52e are gradually adhesive over time. Bonded from the layer 10. In another embodiment (not shown), the adhesive layer 10 is heated during or after UV irradiation to promote UV curing.

  Next, as shown in FIG. 8, the cathode gas diffusion layer 3 c is placed on the cathode electrode catalyst layer 5 c of the membrane electrode assembly 5, and the peripheral portion of the cathode gas diffusion layer 3 c is placed on the inner portion 13 of the adhesive layer 10. Place 3ce. At this time, the peripheral portion 3ce of the cathode gas diffusion layer 3c is pressed against the inner portion 13 of the adhesive layer 10 by applying a load from above. At this stage, since the adhesive layer 10 can still flow with a small force, the inner portion 13 of the adhesive layer 10 can penetrate into the peripheral portion 3ce of the porous body. Therefore, the peripheral portion 3ce of the cathode gas diffusion layer 3c does not rise so as to be carried by the upper part of the adhesive layer 10. In another embodiment (not shown), after the adhesive layer 10 is formed on the outer peripheral edge 52e, the adhesive layer 10 is then irradiated with ultraviolet rays UV so as not to be completely cured, and then the support frame is formed on the adhesive layer 10. 2 and the cathode gas diffusion layer 3c are disposed, and then the other is disposed.

  Next, as shown in FIG. 9, the membrane electrode assembly 5 and the cathode gas diffusion layer 3 c are heated and compressed by a hot press process and thermocompression bonded. The conditions for hot pressing are, for example, 140 ° C. and 5 minutes. Thereby, the cathode electrode catalyst layer 5c and the cathode gas diffusion layer 3c are joined, and the membrane electrode assembly 5 and the cathode gas diffusion layer 3c are integrated. Further, by the end of this stage, cationic polymerization in the adhesive layer 10 proceeds, the adhesive layer 10 is cured, and the membrane electrode assembly 5 and the support frame 2 are integrated. As a result, the membrane electrode assembly 5 having the gas diffusion layers 3a and 3c and the support frame 2 are integrated.

  Thereafter, as shown in FIG. 10, the anode separator 4a is brought into contact with the anode gas diffusion layer 3a at the central portion 4am, and is fixed to the support frame main body 21 with another adhesive layer at the peripheral portion 4ae. In both cases, the cathode separator 4c is brought into contact with the cathode gas diffusion layer 3c at the central portion 4cm, and is fixed to the support frame main body 21 with another adhesive layer at the peripheral portion 4ce. As a result, the membrane electrode assembly 5 and the support frame 2 having the gas diffusion layers 3a and 3c are integrated with the separators 4a and 4c.

  The fuel cell single cell 1 is manufactured as described above.

  Here, in order to explain the effect of the above-described method for manufacturing a fuel cell unit cell (hereinafter referred to as “method for manufacturing the example”), another method for manufacturing a unit cell for fuel cell (which differs from the method for manufacturing the example) ( Hereinafter, it will be described as “manufacturing method of comparative example”.

  A fuel cell single cell 101 manufactured by the manufacturing method of the comparative example has the configuration shown in FIG. The manufacturing method of the comparative example is as follows. That is, first, the membrane electrode assembly 105 in which the anode gas diffusion layer 103a is disposed on one side surface 151 is prepared. Next, the adhesive layer 110 having ultraviolet curability is formed on the outer peripheral edge portion 52e1 of the other side surface 152 of the membrane electrode assembly 105. Subsequently, the inner portion 122 of the support frame 102 is disposed on the outer portion 111 of the adhesive layer 110. Thereafter, the adhesive layer 110 is completely cured with ultraviolet rays to bond the support frame 102 and the membrane electrode assembly 105. Subsequently, the peripheral portion 103ce of the cathode gas diffusion layer 103c is disposed on the inner portion 113 of the adhesive layer 110. Thereafter, the anode gas diffusion layer 103a, the membrane electrode assembly 105, and the cathode gas diffusion layer 103c are hot pressed to integrate the membrane electrode assembly 105 having the support frame 102 and the gas diffusion layers 103a, 103c.

  In the manufacturing method of this comparative example, the adhesive layer 110 is completely cured before the peripheral portion 103ce of the cathode gas diffusion layer 103c is disposed on the inner portion 113 of the adhesive layer 110. For this reason, when the peripheral portion 103ce is subsequently disposed on the inner portion 113, the peripheral portion 103ce is held on the inner portion 113 and is raised. As a result, the flow path of the supply gas defined by the cathode gas diffusion layer 103c and the cathode separator (not shown) on the cathode gas diffusion layer 103c is blocked at the rising portion, or the fibers forming the cathode gas diffusion layer 103c are rising. There is a possibility that the battery performance may be deteriorated due to a phenomenon such as fluffing in a part or excessive surface pressure applied to the membrane electrode assembly 105 under the adhesive layer 110.

  On the other hand, in the manufacturing method of the embodiment, the cathode gas diffusion layer 3c is disposed on the adhesive layer 10 before the adhesive layer 10 is completely cured as shown in FIG. It can be immersed in the layer 3c. Thereby, it is possible to prevent the cathode gas diffusion layer 3c from overlapping with the upper part of the adhesive layer 10 and rising. As a result, the oxidant gas supply path 31 defined by the cathode gas diffusion layer 3c and the cathode separator 4c thereon is blocked, the fibers forming the cathode gas diffusion layer 3c are fluffed at the raised portion, and bonded. It is possible to prevent an excessive surface pressure from being applied to the membrane electrode assembly 5 under the agent layer 10, and it is possible to prevent a decrease in battery performance due to those reasons.

  In the manufacturing method of the above embodiment, the adhesive layer 10 is applied to the outer peripheral edge 52e of the membrane electrode assembly 5 before the support frame 2 and the cathode gas diffusion layer 3c are arranged. Exposure can be reliably prevented. Moreover, since the support frame 2 is bonded to the membrane electrode assembly 5 using the adhesive layer 10 having ultraviolet curing properties, deformation of the support frame 2 due to heat can be avoided.

  According to the method for manufacturing a single fuel cell described above, the outer peripheral edge 52e of the membrane electrode assembly 5 is not exposed, and the support frame 2, the gas diffusion layer 3, and the membrane electrode joint are not deformed by heat or the like. The body 5 can be reliably integrated.

  In another embodiment (not shown), when a material that does not transmit ultraviolet rays of a predetermined wavelength for curing the adhesive layer 10 is used as the material of the support frame 2, the adhesive layer 10 is first bonded after being formed on the outer peripheral edge 52e. Before the adhesive layer is completely cured, either one of the support frame 2 and the cathode gas diffusion layer 3c is disposed on the adhesive layer 10 and further thereafter Or place the other. Even when a material that does not transmit ultraviolet rays of a predetermined wavelength for curing the adhesive layer 10 is used as the material of the support frame 2, the support frame 2 can be fixed with a UV curable adhesive that does not require heating. Therefore, the support frame 2 is not deformed by heating.

  In the above embodiment, one side surface 51 of the membrane electrode assembly 5 is the anode electrode side surface, and the other side surface 52 is the cathode electrode side surface. In another embodiment (not shown), one side surface of the membrane electrode assembly 5 is a cathode electrode side surface, and the other side surface is an anode electrode side surface.

DESCRIPTION OF SYMBOLS 1 Fuel cell single cell 2 Support frame 3a Anode gas diffusion layer 3c Cathode gas diffusion layer 3ce Peripheral part 5 Membrane electrode assembly 5a Anode electrode catalyst layer 5c Cathode electrode catalyst layer 5e Electrolyte membrane 10 Adhesive layer 11 Outer part 13 Inner part 22 Projection 52e Outer peripheral edge

Claims (6)

A membrane electrode assembly in which electrode catalyst layers are respectively formed on both sides of the electrolyte membrane; a first gas diffusion layer disposed on one side of the membrane electrode assembly; and on the other side of the membrane electrode assembly A fuel cell single cell manufacturing method comprising: a second gas diffusion layer disposed; and a support frame that supports the membrane electrode assembly on an outer periphery of the membrane electrode assembly,
Preparing the membrane electrode assembly in which the first gas diffusion layer is disposed on the one side surface and the second gas diffusion layer is not disposed on the other side surface;
Forming a cationic polymerization type ultraviolet curable adhesive layer on the outer peripheral edge of the other side surface of the membrane electrode assembly;
Placing the inner part of the support frame on the outer part of the adhesive layer and irradiating the adhesive layer with ultraviolet rays so that the adhesive layer initiates photopolymerization but does not completely cure;
The step of disposing the second gas diffusion layer on the other side surface of the membrane electrode assembly after the adhesive layer is irradiated with ultraviolet rays and before the adhesive layer is completely cured, A step of arranging the peripheral portion of the second gas diffusion layer so as to overlap the inner portion of the adhesive layer;
Comprising
A method for producing a single fuel cell. The support frame can transmit ultraviolet rays of a predetermined wavelength for curing the adhesive layer,
The step of disposing the support frame on the adhesive layer and irradiating the adhesive layer with ultraviolet rays,
Disposing the inner portion of the support frame on the outer portion of the adhesive layer;
Irradiating the adhesive layer with ultraviolet rays of the predetermined wavelength so that the adhesive layer starts photopolymerization but is not completely cured after disposing the support frame on the adhesive layer;
including,
The manufacturing method of the fuel cell single cell of Claim 1. The step of disposing the support frame on the adhesive layer and irradiating the adhesive layer with ultraviolet rays,
Irradiating the adhesive layer with ultraviolet rays so that the adhesive layer starts photopolymerization but is not completely cured;
Disposing the inner portion of the support frame on the outer portion of the adhesive layer after irradiating the adhesive layer with ultraviolet light; and
including,
The manufacturing method of the fuel cell single cell of Claim 1. The one side surface of the membrane electrode assembly is an anode electrode side surface, and the other side surface is a cathode electrode side surface.
The manufacturing method of the fuel cell single cell as described in any one of Claims 1 thru | or 3. A step of thermocompression bonding the membrane electrode assembly and the second gas diffusion layer to each other;
The manufacturing method of the fuel cell single cell as described in any one of Claims 1 thru | or 4. The support frame includes a support frame main body, and a protrusion that extends from an inner edge side of the support frame main body to the inside of the support frame main body and is thinner than the support frame main body, and the inner portion of the support frame Is formed from the protrusion,
The method for producing a single fuel cell according to any one of claims 1 to 5.

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