JP6126049B2 - Manufacturing method of fuel cell - Google Patents

Description

  The present invention relates to a method of manufacturing a fuel cell including a stepped electrolyte membrane / electrode structure with a frame in which a stepped electrolyte membrane / electrode structure and a resin frame member are joined.

  In general, a polymer electrolyte fuel cell employs a polymer electrolyte membrane made of a polymer ion exchange membrane. A fuel cell has an electrolyte membrane / electrode structure (MEA) in which an anode electrode and a cathode electrode each comprising a catalyst layer (electrode catalyst layer) and a gas diffusion layer (porous carbon) are disposed on both sides of a solid polymer electrolyte membrane. ). The electrolyte membrane / electrode structure is sandwiched between separators (bipolar plates). A predetermined number of fuel cells are stacked to constitute a fuel cell stack, and are used as, for example, an in-vehicle fuel cell stack.

  In the electrolyte membrane / electrode structure, one gas diffusion layer is set to a smaller surface area than the solid polymer electrolyte membrane, and the other gas diffusion layer is set to the same surface area as the solid polymer electrolyte membrane. A so-called step MEA may be configured. At that time, a step MEA with a frame incorporating a resin frame member is used to reduce the amount of use of a relatively expensive solid polymer electrolyte membrane and to protect the solid polymer electrolyte membrane that is thin and low in strength. Has been.

  For example, an electrolyte membrane-electrode assembly disclosed in Patent Document 1 is known. In this electrolyte membrane-electrode assembly, as shown in FIG. 15, an anode catalyst layer 2 a and an anode gas diffusion layer 2 b are disposed on one side of the membrane 1. On the other side of the membrane 1, a cathode catalyst layer 3a and a cathode gas diffusion layer 3b are disposed. Thus, the step MEA 4 is configured.

  The anode gas diffusion layer 2 b is set to have a larger area than the cathode gas diffusion layer 3 b, and the outer peripheral portion of the film 1 on the cathode gas diffusion layer 3 b side and the gasket structure 5 are joined via an adhesion site 6. Has been.

JP 2007-66766 A

  By the way, in the above-mentioned Patent Document 1, the outer peripheral edge (plane) of the membrane 1 on the cathode gas diffusion layer 3b side and the plane of the inner peripheral thin portion 5a of the gasket structure 5 are connected via the bonding portion 6 having a frame shape. Are joined. For this reason, there exists a problem that the adhesive strength of level | step difference MEA4 and the gasket structure 5 falls easily, and the edge part peeling and damage of the level | step difference MEA4 are caused.

  The present invention solves this type of problem and provides a method of manufacturing a fuel cell capable of reliably joining a stepped electrolyte membrane / electrode structure and a resin frame member with a simple process. With the goal.

  The present invention relates to a method of manufacturing a fuel cell including a stepped electrolyte membrane / electrode structure with a frame in which a stepped electrolyte membrane / electrode structure and a resin frame member are joined. In the step electrolyte membrane / electrode structure, a first electrode having a first catalyst layer and a first gas diffusion layer is disposed on one surface of the solid polymer electrolyte membrane, and the other electrode of the solid polymer electrolyte membrane is provided. A second electrode having a second catalyst layer and a second gas diffusion layer is disposed on the surface. The planar dimension of the first gas diffusion layer is set to be larger than the planar dimension of the second gas diffusion layer.

  The resin frame member has a frame shape that circulates around the outer periphery of the solid polymer electrolyte membrane, and is provided with an inner peripheral protrusion that is formed thinly through the step and protrudes toward the second gas diffusion layer. Yes.

In this manufacturing method, a step electrolyte membrane / electrode structure and a resin frame member are individually manufactured, and an adhesive sheet having a frame shape is attached to the step electrolyte membrane / electrode structure and the resin frame member. and a step of forming a form shaped to adhere without a gap between. Next, there is a step of bonding the inner peripheral protrusion of the resin frame member and the outer peripheral edge of the step electrolyte membrane / electrode structure with a molded adhesive sheet.

  In this manufacturing method, the molded adhesive sheet is a flat surface formed between the inner peripheral protrusion and the outer peripheral edge of the solid polymer electrolyte membrane protruding outward from the end of the second gas diffusion layer. It is preferable to have a part. At this time, a first bent portion that is bent at a substantially right angle with respect to the flat surface portion is formed between the tip of the inner peripheral protrusion and the tip of the second gas diffusion layer, and substantially inward from the tip. It is preferable that a second bent portion that is bent at a right angle and substantially parallel to the flat portion is provided.

Further, in this manufacturing method, in the step of forming the adhesive sheet , the adhesive sheet is formed between the mold member and the step electrolyte membrane / electrode structure, and is formed before the step of bonding with the adhesive sheet. It is preferable to further include a step of providing the adhesive sheet on the outer peripheral edge of the step electrolyte membrane / electrode structure .

Furthermore, in this manufacturing method, in the step of forming the adhesive sheet , the adhesive sheet is formed between the mold member and the inner peripheral protrusion of the resin frame member, and is formed before the step of bonding with the adhesive sheet. In addition, the method may further include a step of providing the adhesive sheet on the resin frame member .

Further, in this manufacturing method, in the step of forming the adhesive sheet may be molded to the adhesive sheet between a plurality of mold members.

  According to the present invention, the frame-shaped adhesive sheet is preliminarily molded according to the shape of the bonding site between the stepped electrolyte membrane / electrode structure and the resin frame member. For this reason, when the molded adhesive sheet is interposed in the adhesive part between the inner peripheral protrusion of the resin frame member and the outer peripheral part of the step electrolyte membrane / electrode structure, There is no space provided due to poor molding of the adhesive sheet.

  Therefore, stagnation of gas and air can be suppressed as much as possible, and the stepped electrolyte membrane / electrode structure and the resin frame member can be reliably and firmly joined with a simple process.

It is a principal part disassembled perspective explanatory view of the polymer electrolyte fuel cell to which the manufacturing method according to the present invention is applied. FIG. 2 is a sectional view of the fuel cell taken along line II-II in FIG. 1. It is front explanatory drawing by the side of the anode electrode of the level | step difference electrolyte membrane and electrode structure with a frame which comprises the said fuel cell. In the manufacturing method which concerns on the 1st Embodiment of this invention, it is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame. It is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame in the said 1st Embodiment. It is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame in the said 1st Embodiment. It is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame in the said 1st Embodiment. In the manufacturing method which concerns on the 2nd Embodiment of this invention, it is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame. It is explanatory drawing of the method of manufacturing the said stepped electrolyte membrane and electrode structure with a frame in the said 2nd Embodiment. It is explanatory drawing of the method of manufacturing the said stepped electrolyte membrane and electrode structure with a frame in the said 2nd Embodiment. In the manufacturing method which concerns on the 3rd Embodiment of this invention, it is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame. It is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame in the said 3rd Embodiment. It is explanatory drawing of the method of manufacturing the said level | step difference electrolyte membrane and electrode structure with a frame in the said 3rd Embodiment. It is sectional explanatory drawing of the metal mold | die apparatus used for the manufacturing method of the fuel cell which concerns on the 4th Embodiment of this invention. 6 is an explanatory diagram of an electrolyte membrane-electrode assembly disclosed in Patent Document 1. FIG.

  As shown in FIGS. 1 and 2, the polymer electrolyte fuel cell 10 to which the manufacturing method according to the present invention is applied is stacked in the direction of arrow A (for example, the horizontal direction), for example, for in-vehicle use. A fuel cell stack is configured.

  The fuel cell 10 sandwiches a stepped electrolyte membrane / electrode structure 12 with a frame between a first separator 14 and a second separator 16. The first separator 14 and the second separator 16 are made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plating-treated steel plate, a metal plate whose surface is subjected to anticorrosion treatment, a carbon member, or the like.

  As shown in FIG. 2, the stepped electrolyte membrane / electrode structure 12 with a frame includes a step MEA (stepped electrolyte membrane / electrode structure) 12a. The step MEA 12a includes, for example, a solid polymer electrolyte membrane (cation exchange membrane) 18 in which a perfluorosulfonic acid thin film is impregnated with water, and a cathode electrode (first electrode) 20 sandwiching the solid polymer electrolyte membrane 18. And an anode electrode (second electrode) 22. The solid polymer electrolyte membrane 18 uses an HC (hydrocarbon) electrolyte in addition to a fluorine electrolyte.

  The anode electrode 22 has a smaller planar dimension than the solid polymer electrolyte membrane 18 and the cathode electrode 20. The cathode electrode 20 may have a smaller planar dimension than the solid polymer electrolyte membrane 18 and the anode electrode 22. At that time, the anode electrode 22 becomes the first electrode, while the cathode electrode 20 becomes the second electrode.

  The cathode electrode 20 is disposed on one surface 18 a of the solid polymer electrolyte membrane 18, and the anode electrode 22 is disposed on the other surface 18 b of the solid polymer electrolyte membrane 18.

  The cathode electrode 20 includes a first electrode catalyst layer (first catalyst layer) 20a joined to the surface 18a of the solid polymer electrolyte membrane 18, and a first gas diffusion layer 20b laminated on the first electrode catalyst layer 20a. Have The first electrode catalyst layer 20 a and the first gas diffusion layer 20 b are set to have the same planar dimensions, that is, the same planar dimensions as the solid polymer electrolyte membrane 18.

  The anode electrode 22 includes a second electrode catalyst layer (second catalyst layer) 22a joined to the surface 18b of the solid polymer electrolyte membrane 18, and a second gas diffusion layer 22b laminated on the second electrode catalyst layer 22a. Have The second electrode catalyst layer 22a is set to have a larger planar dimension than the second gas diffusion layer 22b (or the same planar dimension as the second gas diffusion layer 22b). The first electrode catalyst layer 20a has a larger planar dimension than the second electrode catalyst layer 22a, but the first electrode catalyst layer 20a and the second electrode catalyst layer 22a are set to the same planar dimension. May be.

  For example, the first electrode catalyst layer 20a and the second electrode catalyst layer 22a form catalyst particles in which platinum particles are supported on carbon black, and use a polymer electrolyte as an ion conductive binder. The catalyst paste prepared by uniformly mixing the catalyst particles in the polymer electrolyte solution is configured by printing, coating or transferring on both surfaces 18a and 18b of the solid polymer electrolyte membrane 18.

  The first gas diffusion layer 20b and the second gas diffusion layer 22b are formed, for example, by applying a base layer (intermediate layer) containing carbon black and PTFE (polytetrafluoroethylene) particles to carbon paper. The underlayer is set to have the same planar dimensions as the carbon paper. In addition, what is necessary is just to provide a base layer as needed. The planar dimension of the first gas diffusion layer 20b is set to be larger than the planar dimension of the second gas diffusion layer 22b.

  As shown in FIGS. 1 and 2, the stepped electrolyte membrane / electrode structure 12 with a frame includes a resin frame member 24 bonded (adhered) to the stepped MEA 12a. The resin frame member 24 includes, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), It is composed of silicone rubber, fluorine rubber, EPDM (ethylene propylene rubber), m-PPE (modified polyphenylene ether resin), or the like.

  The resin frame member 24 has a frame shape, is formed in a thin shape via a stepped portion, protrudes to the outer peripheral side of the anode electrode 22, and has an inner periphery that contacts the outer peripheral edge portion 18 be of the solid polymer electrolyte membrane 18. It has a protrusion 24a. The outer peripheral edge 18be of the solid polymer electrolyte membrane 18 extends outward from the outer peripheral end of the second electrode catalyst layer 22a constituting the anode electrode 22.

  The inner peripheral protrusion 24a extends inward from the inner peripheral wall surface 24b with a predetermined length, and extends from the outer peripheral edge 18be of the solid polymer electrolyte membrane 18 to the tip edge of the second electrode catalyst layer 22a. It is placed over. A predetermined gap is formed between the tip of the step MEA 12a and the inner peripheral wall surface 24b.

  A frame-shaped adhesive sheet 26 is provided between the outer peripheral edge 18be of the solid polymer electrolyte membrane 18 and the inner peripheral protrusion 24a of the resin frame member 24 (adhesion site). The adhesive sheet 26 is formed in advance before bonding, and as shown in FIGS. 2 and 3, a flat portion formed between the inner peripheral protrusion 24 a and the outer peripheral edge 18 be of the solid polymer electrolyte membrane 18. 26a. The flat surface portion 26a extends from the outer peripheral edge portion 18be to cover the tip edge portion of the second electrode catalyst layer 22a.

  The adhesive sheet 26 is provided with a first bent portion 26b that is bent at a substantially right angle with respect to the flat surface portion 26a between the tip of the inner peripheral protrusion 24a and the tip of the second gas diffusion layer 22b. At the tip of the first bent portion 26b, there is provided a second bent portion 26c that is bent at a substantially right angle inward from the tip and is substantially parallel to the flat portion 26a. The second bent portion 26c has an overlapping portion 26cc that overlaps the surface of the outer peripheral edge of the second gas diffusion layer 22b in the stacking direction. The adhesive sheet 26 has an overlapping portion that is in direct contact with the second electrode catalyst layer 22a. The outer peripheral end of the adhesive sheet 26 is disposed at substantially the same position as the tips of the solid polymer electrolyte membrane 18 and the cathode electrode 20.

  For the adhesive sheet 26, for example, a thermoplastic or thermosetting adhesive is used. In the first embodiment, the adhesive sheet 26 is configured by an ester-based, acrylic-based, or urethane-based hot melt sheet. The hot melt sheet is a sheet-like adhesive that melts by heating and solidifies by cooling to obtain an adhesive force.

  As shown in FIG. 1, one end edge of the fuel cell 10 in the direction of arrow B (horizontal direction in FIG. 1) communicates with each other in the direction of arrow A, which is the stacking direction. A cooling medium inlet communication hole 32a and a fuel gas outlet communication hole 34b are provided. The oxidant gas inlet communication hole 30a supplies an oxidant gas, for example, an oxygen-containing gas, while the cooling medium inlet communication hole 32a supplies a cooling medium. The fuel gas outlet communication hole 34b discharges fuel gas, for example, hydrogen-containing gas. The oxidant gas inlet communication hole 30a, the cooling medium inlet communication hole 32a, and the fuel gas outlet communication hole 34b are arranged in the direction of arrow C (vertical direction).

  The other end edge of the fuel cell 10 in the direction of arrow B communicates with each other in the direction of arrow A, the fuel gas inlet communication hole 34a for supplying fuel gas, the cooling medium outlet communication hole 32b for discharging the cooling medium, and the oxidation An oxidant gas outlet communication hole 30b for discharging the oxidant gas is provided. The fuel gas inlet communication hole 34a, the cooling medium outlet communication hole 32b, and the oxidant gas outlet communication hole 30b are arranged in the direction of arrow C.

  An oxidant gas flow path 36 communicating with the oxidant gas inlet communication hole 30a and the oxidant gas outlet communication hole 30b is provided on the surface 16a of the second separator 16 facing the stepped electrolyte membrane / electrode structure 12. .

  A fuel gas flow path 38 communicating with the fuel gas inlet communication hole 34 a and the fuel gas outlet communication hole 34 b is formed on the surface 14 a of the first separator 14 facing the stepped electrolyte membrane / electrode structure 12. A cooling medium flow path 40 communicating with the cooling medium inlet communication hole 32a and the cooling medium outlet communication hole 32b is formed between the surface 14b of the first separator 14 and the surface 16b of the second separator 16 adjacent to each other. .

  As shown in FIGS. 1 and 2, the first seal member 42 is integrated with the surfaces 14 a and 14 b of the first separator 14 around the outer peripheral end of the first separator 14. The second seal member 44 is integrated with the surfaces 16 a and 16 b of the second separator 16 around the outer peripheral end portion of the second separator 16.

  As shown in FIG. 2, the first seal member 42 includes a first convex seal 42 a that contacts the inner peripheral protrusion 24 a of the resin frame member 24 constituting the stepped electrolyte membrane / electrode structure 12 with a frame, and a second And a second convex seal 42b that contacts the second seal member 44 of the separator 16. The second seal member 44 constitutes a planar seal that extends in a planar shape along the separator surface. Instead of the second convex seal 42b, the second seal member 44 may be provided with a convex seal (not shown).

  For the first seal member 42 and the second seal member 44, for example, EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber or the like, cushion material Alternatively, an elastic seal member such as a packing material is used.

  As shown in FIG. 1, the first separator 14 has a supply hole portion 46 that communicates the fuel gas inlet communication hole 34a with the fuel gas passage 38, and the fuel gas passage 38 communicates with the fuel gas outlet communication hole 34b. A discharge hole 48 is formed.

  Next, a method for manufacturing the fuel cell 10 according to the first embodiment of the present invention will be described below.

  First, the step MEA 12a is manufactured, and the resin frame member 24 is molded by injection molding using a mold (not shown). The resin frame member 24 integrally has a thin inner protrusion 24a.

  As shown in FIG. 4, a frame-shaped flat plate adhesive sheet 26 p is disposed between the step MEA 12 a and the heated mold member 50. The mold member 50 has a press surface 50a corresponding to the inner peripheral protrusion 24a of the resin frame member 24 on the surface facing the step MEA 12a.

  Then, as shown in FIG. 5, the adhesive sheet 26 having a bent shape is formed by performing press molding on the flat adhesive sheet 26 p between the mold member 50 and the step MEA 12 a. Specifically, the adhesive sheet 26 is provided with the step MEA 12a while the flat portion 26a, the first bent portion 26b, and the second bent portion 26c are integrally formed.

  Next, after the mold member 50 is released, as shown in FIG. 6, the resin frame member 24 is disposed to face the step MEA 12a. Therefore, the inner peripheral protrusion 24a and the step MEA 12a of the resin frame member 24 are stacked on each other with the adhesive sheet 26 interposed therebetween. In this state, as shown in FIG. 7, the adhesive sheet 26 is heated and melted (hot melt) and a load (press or the like) is applied. In addition, as a bonding method using the adhesive sheet 26, a hot press or a roll press is adopted, and either single-side heating or double-side heating may be used.

  For this reason, the inner peripheral protrusion 24a and the solid polymer electrolyte membrane 18 are bonded together, and the stepped electrolyte membrane / electrode structure 12 with a frame is manufactured. As shown in FIG. 2, the stepped electrolyte membrane / electrode structure 12 with a frame is sandwiched between a first separator 14 and a second separator 16. The first separator 14 abuts on the inner peripheral protrusion 24 a of the resin frame member 24 and applies a load to the stepped electrolyte membrane / electrode structure 12 with the second separator 16.

  Thereby, the fuel cell 10 is manufactured. A predetermined number of fuel cells 10 are stacked to form a fuel cell stack, and a clamping load is applied between end plates (not shown).

  The operation of the fuel cell 10 configured as described above will be described below.

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas inlet communication hole 30a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 34a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 32a.

  Therefore, the oxidant gas is introduced from the oxidant gas inlet communication hole 30a into the oxidant gas flow path 36 of the second separator 16, moves in the direction of arrow B, and is supplied to the cathode electrode 20 of the step MEA 12a. On the other hand, the fuel gas is introduced from the fuel gas inlet communication hole 34 a through the supply hole 46 into the fuel gas flow path 38 of the first separator 14. The fuel gas moves in the direction of arrow B along the fuel gas flow path 38 and is supplied to the anode electrode 22 of the step MEA 12a.

  Therefore, in each step MEA 12a, the oxidant gas supplied to the cathode electrode 20 and the fuel gas supplied to the anode electrode 22 are caused by an electrochemical reaction in the first electrode catalyst layer 20a and the second electrode catalyst layer 22a. It is consumed to generate electricity.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 20 is discharged in the direction of arrow A along the oxidant gas outlet communication hole 30b. Similarly, the fuel gas consumed by being supplied to the anode electrode 22 passes through the discharge hole 48 and is discharged in the direction of arrow A along the fuel gas outlet communication hole 34b.

  The cooling medium supplied to the cooling medium inlet communication hole 32a is introduced into the cooling medium flow path 40 between the first separator 14 and the second separator 16, and then flows in the direction of arrow B. This cooling medium is discharged from the cooling medium outlet communication hole 32b after the step MEA 12a is cooled.

  In this case, in the first embodiment, as shown in FIG. 5, the adhesive sheet 26 having a bent shape is formed by press-molding the flat adhesive sheet 26p between the mold member 50 and the step MEA 12a. ing. For this reason, the frame-shaped adhesive sheet 26 is molded in advance following the shape of the bonding portion between the step MEA 12a and the resin frame member 24 (see FIG. 6).

  Therefore, as shown in FIG. 7, when the adhesive sheet 26 is interposed in the adhesion part between the inner peripheral protrusion 24 a of the resin frame member 24 and the outer peripheral edge part of the step MEA 12 a, There is no provision of voids due to poor molding of the adhesive sheet 26. As a result, the retention of gas and air can be suppressed as much as possible, and the effect that the step MEA 12a and the resin frame member 24 can be reliably and firmly joined in a simple process is obtained.

  8-10 is explanatory drawing of the manufacturing method of the fuel cell 10 which concerns on the 2nd Embodiment of this invention.

  As shown in FIG. 8, a flat plate adhesive sheet 26 p is disposed between the resin frame member 24 and the mold member 52. The mold member 52 has a press surface 52a corresponding to the outer peripheral edge of the step MEA 12a on the surface facing the inner peripheral protrusion 24a of the resin frame member 24.

  Then, as shown in FIG. 9, the adhesive sheet 26 having a bent shape is formed by press-molding the flat plate adhesive sheet 26 p between the heated mold member 52 and the resin frame member 24. Specifically, the adhesive sheet 26 is provided on the resin frame member 24 while the flat portion 26a, the first bent portion 26b, and the second bent portion 26c are integrally formed.

  Next, after the mold member 52 is released, the step MEA 12a is disposed to face the resin frame member 24 as shown in FIG. Therefore, the inner peripheral protrusion 24a and the step MEA 12a of the resin frame member 24 are stacked on each other with the adhesive sheet 26 interposed therebetween. In this state, as shown in FIG. 7, the adhesive sheet 26 is heated and melted (hot melt) and a load (press or the like) is applied.

  In this case, in the second embodiment, the frame-shaped adhesive sheet 26 is molded in advance by using the mold member 52 and the resin frame member 24, following the shape of the bonding portion between the step MEA 12 a and the resin frame member 24. (See FIG. 9). For this reason, the same effects as those of the first embodiment described above can be obtained, such as the step MEA 12a and the resin frame member 24 can be reliably and firmly joined by a simple process.

  FIGS. 11-13 is explanatory drawing of the manufacturing method of the fuel cell 10 which concerns on the 3rd Embodiment of this invention.

  As shown in FIG. 11, the flat plate adhesive sheet 26 p is disposed between the first mold member 54 and the second mold member 56 which are a plurality of mold members. The first mold member 54 has a press surface 54a corresponding to the inner peripheral protrusion 24a of the resin frame member 24, while the second mold member 56 has a press surface 56a corresponding to the outer peripheral edge of the step MEA 12a. Note that the number of the plurality of mold members is not limited to two, and may include three or more mold members.

  Therefore, as shown in FIG. 12, the flat adhesive sheet 26p is press-formed between the heated first mold member 54 and the heated second mold member 56, whereby the adhesive sheet 26 having a bent shape is formed. Is formed. Specifically, in the adhesive sheet 26, a flat portion 26a, a first bent portion 26b, and a second bent portion 26c are integrally formed.

  Next, after the first mold member 54 and the second mold member 56 are released, as shown in FIG. 13, the step MEA 12 a and the resin frame member 24 are laminated with the adhesive sheet 26 interposed therebetween. . In this state, as shown in FIG. 7, the adhesive sheet 26 is heated and melted (hot melt) and a load (press or the like) is applied.

  In this case, in the third embodiment, the frame-shaped adhesive sheet 26 uses the first mold member 54 and the second mold member 56 to imitate the shape of the adhesion site between the step MEA 12a and the resin frame member 24 in advance. (See FIG. 12). For this reason, the same effects as those in the first and second embodiments described above can be obtained, for example, the step MEA 12a and the resin frame member 24 can be reliably and firmly joined by a simple process.

  FIG. 14 is a cross-sectional explanatory view of a mold apparatus 58 used in the method for manufacturing the fuel cell 10 according to the fourth embodiment of the present invention.

  The mold device 58 includes a first mold 60 and a second mold 62, and a cavity 64 is formed between the first mold 60 and the second mold 62 when the mold is clamped. The cavity 64 corresponds to the shape of the molded adhesive sheet 26. The second mold 62 is formed with a gate 66 for filling the cavity 64 with a molten hot melt agent.

  In the fourth embodiment, in the mold device 58, the molten hot melt agent is filled into the cavity 64 from the plurality of gates 66, and the hot melt agent is cured, whereby the adhesive sheet 26 is manufactured.

  The adhesive sheet 26 is detached from the mold device 58 and the gate portion is cut, and as in the third embodiment, as shown in FIG. Is done. Then, the adhesive sheet 26 is heated and melted (hot melt) and a load (press or the like) is applied.

  As described above, in the fourth embodiment, the step MEA 12a and the resin frame member 24 can be reliably and firmly joined in a simple process, and the same as in the first to third embodiments. The effect is obtained.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 12 ... Stepped electrolyte membrane and electrode structure 12a with a frame ... Step MEA 14, 16 ... Separator 18 ... Solid polymer electrolyte membrane 18be ... Outer peripheral edge 20 ... Cathode electrodes 20a, 22a ... Electrode catalyst layers 20b, 22b ... Gas diffusion layer 22 ... Anode electrode 24 ... Resin frame member 24a ... Inner peripheral projection 26 ... Adhesive sheet 26a ... Plane part 26b, 26c ... Bending part 30a ... Oxidant gas inlet communication hole 30b ... Oxidant gas outlet communication hole 32a ... cooling medium inlet communication hole 32b ... cooling medium outlet communication hole 34a ... fuel gas inlet communication hole 34b ... fuel gas outlet communication hole 36 ... oxidant gas flow path 38 ... fuel gas flow path 40 ... cooling medium flow path 42, 44 ... Seal members 50, 52, 54, 56 ... Mold members 50a, 52a, 54a, 56a ... Press surface 58 ... Mold device 60, 62 ... Mold 64 ... Cavite

Claims (3)

A first electrode having a first catalyst layer and a first gas diffusion layer is disposed on one surface of the solid polymer electrolyte membrane, and a second catalyst layer and a second electrode are disposed on the other surface of the solid polymer electrolyte membrane. A step electrolyte membrane / electrode structure in which a second electrode having two gas diffusion layers is disposed, and a planar dimension of the first gas diffusion layer is set larger than a planar dimension of the second gas diffusion layer Body,
A resin frame member having a frame shape that circulates around the outer periphery of the solid polymer electrolyte membrane, provided with an inner peripheral protrusion that is formed thinly through a step portion and protrudes toward the second gas diffusion layer; ,
A method for producing a fuel cell comprising a stepped electrolyte membrane / electrode structure with a frame to which is joined,
Separately producing the stepped electrolyte membrane / electrode structure and the resin frame member;
A step of an adhesive sheet, which formed the shape between the adhering portion to the shape of bonding without a gap between the resin frame member and the stepped membrane electrode assembly having a frame shape,
Bonding the inner peripheral protrusion of the resin frame member and the outer peripheral edge of the step electrolyte membrane / electrode structure with the molded adhesive sheet;
I have a,
The molded adhesive sheet has a flat portion formed between the inner peripheral protrusion and the outer peripheral edge of the solid polymer electrolyte membrane protruding outward from the end of the second gas diffusion layer. A first bent portion that is formed between the tip of the inner peripheral protrusion and the tip of the second gas diffusion layer and bends at right angles to the plane portion; and from the tip of the second gas diffusion layer A second bent portion that is bent inwardly at a right angle and parallel to the plane portion;
Have
In the step of forming the adhesive sheet, the adhesive sheet is formed between a mold member and the step electrolyte membrane / electrode structure,
The method for producing a fuel cell, further comprising the step of providing the molded adhesive sheet on the outer peripheral edge of the stepped electrolyte membrane / electrode structure before the step of bonding with the adhesive sheet . A first electrode having a first catalyst layer and a first gas diffusion layer is disposed on one surface of the solid polymer electrolyte membrane, and a second catalyst layer and a second electrode are disposed on the other surface of the solid polymer electrolyte membrane. A step electrolyte membrane / electrode structure in which a second electrode having two gas diffusion layers is disposed, and a planar dimension of the first gas diffusion layer is set larger than a planar dimension of the second gas diffusion layer Body,
A resin frame member having a frame shape that circulates around the outer periphery of the solid polymer electrolyte membrane, provided with an inner peripheral protrusion that is formed thinly through a step portion and protrudes toward the second gas diffusion layer; ,
A method for producing a fuel cell comprising a stepped electrolyte membrane / electrode structure with a frame to which is joined,
Separately producing the stepped electrolyte membrane / electrode structure and the resin frame member;
A step of forming an adhesive sheet having a frame shape into a shape that adheres between the adhesion portions of the stepped electrolyte membrane / electrode structure and the resin frame member without gaps;
Bonding the inner peripheral protrusion of the resin frame member and the outer peripheral edge of the step electrolyte membrane / electrode structure with the molded adhesive sheet;
Have
The molded adhesive sheet has a flat portion formed between the inner peripheral protrusion and the outer peripheral edge of the solid polymer electrolyte membrane protruding outward from the end of the second gas diffusion layer. A first bent portion that is formed between the tip of the inner peripheral protrusion and the tip of the second gas diffusion layer and bends at right angles to the plane portion; and from the tip of the second gas diffusion layer A second bent portion that is bent inwardly at a right angle and parallel to the plane portion;
Have
In the step of forming the adhesive sheet, the adhesive sheet is formed between a mold member and the inner peripheral protrusion of the resin frame member ,
Wherein prior to the step of bonding the adhesive sheet, a manufacturing method of a fuel cell, characterized by further comprising the step of providing the adhesive sheet formed before Symbol resin frame member. A first electrode having a first catalyst layer and a first gas diffusion layer is disposed on one surface of the solid polymer electrolyte membrane, and a second catalyst layer and a second electrode are disposed on the other surface of the solid polymer electrolyte membrane. A step electrolyte membrane / electrode structure in which a second electrode having two gas diffusion layers is disposed, and a planar dimension of the first gas diffusion layer is set larger than a planar dimension of the second gas diffusion layer Body,
A resin frame member having a frame shape that circulates around the outer periphery of the solid polymer electrolyte membrane, provided with an inner peripheral protrusion that is formed thinly through a step portion and protrudes toward the second gas diffusion layer; ,
A method for producing a fuel cell comprising a stepped electrolyte membrane / electrode structure with a frame to which is joined,
Separately producing the stepped electrolyte membrane / electrode structure and the resin frame member;
A step of forming an adhesive sheet having a frame shape into a shape that adheres between the adhesion portions of the stepped electrolyte membrane / electrode structure and the resin frame member without gaps;
Bonding the inner peripheral protrusion of the resin frame member and the outer peripheral edge of the step electrolyte membrane / electrode structure with the molded adhesive sheet;
Have
The molded adhesive sheet has a flat portion formed between the inner peripheral protrusion and the outer peripheral edge of the solid polymer electrolyte membrane protruding outward from the end of the second gas diffusion layer. A first bent portion that is formed between the tip of the inner peripheral protrusion and the tip of the second gas diffusion layer and bends at right angles to the plane portion; and from the tip of the second gas diffusion layer A second bent portion that is bent inwardly at a right angle and parallel to the plane portion;
Have
In the step of forming the adhesive sheet, mold the adhesive sheet between a plurality of mold members
Method for manufacturing a fuel cell characterized by and this.

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