JP2013145653A - Electrolyte membrane/electrode structure with resin frame for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent end degradation of a solid polymer electrolyte membrane by blocking entry of oxidant gas from the side of a cathode catalyst layer, having external dimension smaller than that of an anode catalyst layer, to the end of the solid polymer electrolyte membrane.SOLUTION: An electrolyte membrane/electrode structure 10 with a resin frame includes an electrolyte membrane/electrode structure 10a having an anode electrode 20 and a cathode electrode 22 sandwiching a solid polymer electrolyte membrane 18, and a resin frame member 24 surrounding the outer periphery of the solid polymer electrolyte membrane 18. The outer peripheral end of an electrode catalyst layer 22a composing the cathode electrode 22 projects farther outward than the outer peripheral end of a gas diffusion layer 22b. The resin frame member 24 has an inner peripheral swollen part 24a projecting to the outer peripheral side of the cathode electrode 22 and abutting against the outer peripheral edge of the solid polymer electrolyte membrane 18. The inner peripheral swollen part 24a of the resin frame member 24 has a part 26 overlapping the outer peripheral edge of the electrode catalyst layer 22a.

Description

  The present invention provides an electrolyte membrane / electrode structure in which an anode electrode and a cathode electrode are provided on both sides of a solid polymer electrolyte membrane, and a resin frame member provided around the outer periphery of the solid polymer electrolyte membrane; The present invention relates to an electrolyte membrane / electrode structure with a resin frame for a fuel cell.

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

  In this type of electrolyte membrane / electrode structure, one electrode (catalyst layer and diffusion layer) is set to have a smaller surface area than the solid polymer electrolyte membrane, and the other electrode is the same as the solid polymer electrolyte membrane. There is a case where a so-called stepped MEA having a surface area is configured.

  For example, in a polymer electrolyte fuel cell disclosed in Patent Document 1, an anode electrode 2 and a cathode electrode 3 are disposed on both sides of a solid polymer electrolyte membrane 1 as shown in FIG. The anode electrode 2 and the cathode electrode 3 are sandwiched between separators 5 and 6 with gas seal portions 4a and 4b arranged on the outer peripheral portions thereof.

  The anode electrode 2 has an anode electrode catalyst layer 2a disposed on one surface of the solid polymer electrolyte membrane 1 and an electrode base material (diffusion layer) 2b disposed outside the anode electrode catalyst layer 2a. Yes. The cathode electrode 3 includes a cathode electrode catalyst layer 3a disposed on the other surface of the solid polymer electrolyte membrane 1 and an electrode substrate (diffusion layer) 3b disposed outside the cathode electrode catalyst layer 3a. Yes.

  The anode electrode catalyst layer 2a and the electrode substrate 2b have the same outer dimensions, and the cathode electrode catalyst layer 3a and the electrode substrate 3b have the same outer dimensions. Further, the anode electrode 2 is set to have a larger outer dimension than the cathode electrode 3.

  The separator 5 is formed with a fuel gas passage 5 a for supplying fuel gas to the anode electrode 2, and the separator 6 is provided with an oxidant gas passage 6 a for supplying oxidant gas to the cathode electrode 3. Is formed.

JP 2009-99265 A

  In the above Patent Document 1, the outer dimension of the cathode electrode 3 is set to be smaller than the outer dimension of the anode electrode 2, and the solid polymer electrolyte membrane 1 has a half-electrode portion in which an electrode is provided only on one side. 7 is configured. On the cathode electrode 3 side, a gap S exists between the outer peripheral end portion and the inner peripheral end portion of the gas seal portion 4b. This is because there are tolerances such as processing accuracy and molding accuracy. For this reason, a part of the oxidant gas supplied to the oxidant gas flow path 6a may penetrate the electrode base material 3b which is a porous body and enter the half electrode part 7 through the gap S.

Accordingly, in the half electrode portion 7, hydrogen that has passed through the solid polymer electrolyte membrane 1 reacts with oxygen in the oxidant gas that has entered as described above, and hydrogen peroxide (H ₂ O ₂ ) is likely to be generated. (H ₂ + O ₂ → H ₂ O ₂ ). This hydrogen peroxide is decomposed on the carbon support or platinum (Pt) in the electrode, and for example, a hydroxy radical (.OH) is generated. Thereby, there exists a problem of degrading the solid polymer electrolyte membrane 1 and an electrode.

  Moreover, on the anode electrode 2 side, the fuel gas passage 5a is not provided in the separator 5 facing the half electrode portion 7 in the stacking direction, and is closed. For this reason, there is a problem that the oxidant gas that has entered the half-electrode portion 7 stays in the half-electrode portion 7 and the above deterioration reaction is promoted.

  The present invention solves this type of problem, and the oxidant gas enters the end of the solid polymer electrolyte membrane from the cathode catalyst layer side having an outer dimension smaller than the outer dimension of the anode catalyst layer. An object of the present invention is to provide an electrolyte membrane / electrode structure with a resin frame for a fuel cell that can prevent and effectively suppress deterioration of the end portion of the solid polymer electrolyte membrane.

  In the present invention, an anode electrode having an anode catalyst layer and an anode diffusion layer is provided on one side of the solid polymer electrolyte membrane, and a cathode catalyst layer and a cathode diffusion are provided on the other side of the solid polymer electrolyte membrane. A cathode electrode having a layer, and an outer peripheral end of the anode catalyst layer includes an electrolyte membrane / electrode structure projecting outward from an outer peripheral end of the cathode catalyst layer, and an outer periphery of the solid polymer electrolyte membrane It is related with the electrolyte membrane and electrode structure with a resin frame for fuel cells provided with the resin-made frame member provided by circling.

  In this electrolyte membrane / electrode structure with a resin frame for fuel cells, the outer peripheral end of the cathode catalyst layer protrudes outward from the outer peripheral end of the cathode diffusion layer, and the resin frame member is formed of the cathode electrode. It has an inner peripheral bulging portion that protrudes toward the outer peripheral side and contacts the outer peripheral edge of the solid polymer electrolyte membrane. And the inner peripheral bulging part of the resin frame member has a polymerization site overlapping with the outer peripheral edge part of the cathode catalyst layer.

  Further, in the electrolyte membrane / electrode structure with a resin frame for a fuel cell, a resin impregnated portion integrated with the resin frame member is provided on the outer peripheral edge portion of the anode diffusion layer. The peripheral edge is preferably located outside the polymerization site along the direction of lamination with the solid polymer electrolyte membrane.

  Furthermore, in this electrolyte membrane / electrode structure with a resin frame for fuel cells, the anode catalyst layer supplies the fuel gas along the anode electrode in the region overlapping the polymerization site along the stacking direction with the solid polymer electrolyte membrane. It is preferable to face the fuel gas flow path.

  According to the present invention, the outer peripheral edge of the cathode catalyst layer protrudes outward from the outer peripheral end of the cathode diffusion layer, and the inner peripheral bulge of the resin frame member is the outer peripheral edge of the cathode catalyst layer. It has a superposition | polymerization site | part which overlaps with a part. For this reason, even if a gap through which the oxidant gas permeates is formed between the outer peripheral end of the cathode diffusion layer and the inner peripheral bulge of the resin frame member, the half electrode of the solid polymer electrolyte membrane is formed from this gap. The oxidant gas does not contact the part. Therefore, the end of the solid polymer electrolyte membrane is effectively and reliably suppressed from being deteriorated by the reaction between the oxidant gas and the fuel gas.

It is a principal part disassembled perspective explanatory view of the polymer electrolyte fuel cell in which the electrolyte membrane / electrode structure with a resin frame according to the embodiment of the present invention is incorporated. FIG. 2 is a sectional view of the fuel cell taken along line II-II in FIG. 1. It is principal part cross-sectional explanatory drawing of the said electrolyte membrane and electrode structure with a resin frame. It is explanatory drawing of one surface of the said electrolyte membrane with a resin frame and an electrode structure. It is front explanatory drawing of the 1st separator which comprises the said fuel cell. It is sectional explanatory drawing of the method of manufacturing the said electrolyte membrane and electrode structure with a resin frame. It is a perspective explanatory view of the method of manufacturing the membrane electrode assembly with resin frame. 2 is an explanatory diagram of a polymer electrolyte fuel cell disclosed in Patent Document 1. FIG.

  As shown in FIGS. 1 and 2, an electrolyte membrane / electrode structure 10 with a resin frame according to an embodiment of the present invention is incorporated into a rectangular polymer electrolyte fuel cell 12 and a plurality of the fuel cells 12. Are stacked in the direction of arrow A to form a fuel cell stack.

  In the fuel cell 12, the electrolyte membrane / electrode structure 10 with a resin frame is sandwiched between the first separator 14 and the second separator 16. The first separator 14 and the second separator 16 have a vertically long rectangular shape, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal plate that has been subjected to anticorrosion surface treatment on its metal surface, It is composed of a carbon member or the like.

  As shown in FIGS. 2 and 3, the electrolyte membrane / electrode structure 10 having a rectangular resin frame includes an electrolyte membrane / electrode structure 10 a, and the electrolyte membrane / electrode structure 10 a is, for example, perfluoro It has a solid polymer electrolyte membrane 18 in which a sulfonic acid thin film is impregnated with water, and an anode electrode 20 and a cathode electrode 22 that sandwich the solid polymer electrolyte membrane 18. The solid polymer electrolyte membrane 18 uses an HC (hydrocarbon) electrolyte in addition to a fluorine electrolyte. The cathode electrode 22 has a smaller surface area than the solid polymer electrolyte membrane 18 and the anode electrode 20.

  The anode electrode 20 includes an electrode catalyst layer (anode catalyst layer) 20a joined to one surface 18a of the solid polymer electrolyte membrane 18, and a gas diffusion layer (anode diffusion layer) 20b laminated on the electrode catalyst layer 20a. Is provided. The electrode catalyst layer 20a and the gas diffusion layer 20b have the same outer dimensions and are set to the same outer dimensions (or less than the same) as the solid polymer electrolyte membrane 18.

  The cathode electrode 22 includes an electrode catalyst layer (cathode catalyst layer) 22a joined to the surface 18b of the solid polymer electrolyte membrane 18, and a gas diffusion layer (cathode diffusion layer) 22b laminated on the electrode catalyst layer 22a. . As shown in FIG. 3, the outer peripheral end 22ae of the electrode catalyst layer 22a protrudes outward (outward in the direction of arrow C) by a length L1 from the outer peripheral end 22be of the gas diffusion layer 22b over the entire periphery. At the same time, the electrode catalyst layer 22 a is set to an outer dimension smaller than the outer dimension of the solid polymer electrolyte membrane 18.

  The electrode catalyst layers 20a and 22a form catalyst particles in which platinum particles are supported on carbon black, use a polymer electrolyte as an ion conductive binder, and uniformly mix the catalyst particles in a solution of the polymer electrolyte. The catalyst paste produced in this way is configured by printing, coating or transferring on both sides of the solid polymer electrolyte membrane 18. The gas diffusion layers 20b and 22b are made of carbon paper, carbon cloth or the like, and the planar dimension of the gas diffusion layer 22b is set smaller than the planar dimension of the gas diffusion layer 20b. The electrode catalyst layers 20a and 22a may each be composed of a plurality of layers.

  As shown in FIGS. 1 to 4, the resin membrane-attached electrolyte membrane / electrode structure 10 circulates around the outer periphery of the solid polymer electrolyte membrane 18 and is joined to the anode electrode 20 and the cathode electrode 22. 24. Examples of the resin frame member 24 include PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyether sulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride). , Silicone rubber, fluorine rubber or EPDM (ethylene propylene rubber).

  The resin frame member 24 has an inner peripheral bulging portion 24 a that protrudes toward the outer peripheral side of the cathode electrode 22 and contacts the outer peripheral edge of the solid polymer electrolyte membrane 18. The inner peripheral bulging portion 24a has the same thickness as the cathode electrode 22, substantially the same thickness as the gas diffusion layer 22b, and the inner peripheral end 24ae of the inner peripheral bulging portion 24a is: A gap S1 is formed between the outer peripheral end 22be of the gas diffusion layer 22b (see FIG. 3).

  The inner peripheral bulging portion 24a of the resin frame member 24 has a polymerization site 26 that overlaps the outer peripheral edge of the electrode catalyst layer 22a along the stacking direction (arrow A direction). In the polymerization site 26, the outer peripheral end portion 22ae of the electrode catalyst layer 22a and the inner peripheral end portion 24ae of the inner peripheral bulge portion 24a overlap each other over the length L2.

  The inner peripheral bulging portion 24 a of the resin frame member 24 is bonded to the outer peripheral edge portion of the solid polymer electrolyte membrane 18 and the outer peripheral edge portion of the electrode catalyst layer 22 a by an adhesive layer 27. For the adhesive layer 27, for example, an ester-based or urethane-based hot melt adhesive is used. The resin frame member 24 and the gas diffusion layer 20b of the anode electrode 20 are integrated by a resin impregnated portion 28a, while the resin frame member 24 and the gas diffusion layer 22b of the cathode electrode 22 are integrated with a resin impregnated portion 28b. Are integrated.

  The adhesive layer 27 is formed in a frame shape over the entire circumference of the outer peripheral edge of the solid polymer electrolyte membrane 18. The resin impregnated portion 28a is formed in a frame shape over the entire circumference of the gas diffusion layer 20b of the anode electrode 20, and the resin impregnated portion 28b extends over the entire circumference of the gas diffusion layer 22b constituting the cathode electrode 22. It is formed in a frame shape. The inner peripheral end 28ae of the resin impregnated portion 28a is positioned outside the polymerization site 26 by a length L3 along the stacking direction (see FIG. 3).

  As shown in FIG. 1, the anode buffer 20 side surface 24as of the resin frame member 24 is provided with an inlet buffer portion 29a corresponding to the inlet side of the fuel gas flow path described later at the upper edge. On the surface 24as of the resin frame member 24, an outlet buffer portion 29b corresponding to the outlet side of the fuel gas flow path is provided at the lower edge. The inlet buffer unit 29a and the outlet buffer unit 29b are configured by a plurality of protrusions 29at and 29bt.

  As shown in FIG. 4, the surface 24cs on the cathode electrode 22 side of the resin frame member 24 is provided with an inlet buffer portion 29c corresponding to the inlet side of the oxidant gas flow path described later at the upper edge. The surface 24cs of the resin frame member 24 is provided with an outlet buffer portion 29d corresponding to the outlet side of the oxidant gas flow path at the lower end edge portion. The inlet buffer portion 29c and the outlet buffer portion 29d are configured by a plurality of protrusions 29ct and 29dt.

  As shown in FIG. 1, the upper edge of the fuel cell 12 in the direction of arrow C (the gravity direction in FIG. 1) communicates with each other in the direction of arrow A, which is the stacking direction. An oxidant gas inlet communication hole 30a for supplying a gas, a cooling medium inlet communication hole 32a for supplying a cooling medium, and a fuel gas inlet communication hole 34a for supplying a fuel gas, for example, a hydrogen-containing gas, Arranged in the direction of arrow B (horizontal direction).

  The lower end edge of the fuel cell 12 in the direction of arrow C communicates with each other in the direction of arrow A, the fuel gas outlet communication hole 34b for discharging the fuel gas, and the cooling medium outlet communication hole 32b for discharging the cooling medium. And oxidant gas outlet communication holes 30b for discharging the oxidant gas are arranged in the direction of arrow B.

  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 electrolyte membrane / electrode structure 10 with a resin frame. . On the inlet side (upper end side) of the oxidant gas flow path 36, a buffer region 38a with which the inlet buffer portion 29c provided at the upper end edge of the surface 24cs of the resin frame member 24 abuts is provided in a substantially flat shape. It is done. A plurality of inlet connection paths 40a are connected to one end on the upper side of the buffer region 38a from the oxidant gas inlet communication hole 30a.

  On the outlet side (lower end side) of the oxidant gas flow path 36, a buffer region 38b is provided in contact with the outlet buffer portion 29d provided at the lower end edge of the surface 24cs of the resin frame member 24. A plurality of outlet connection paths 40b are connected to one end side of the buffer region 38b from the oxidant gas outlet communication hole 30b.

  As shown in FIG. 5, a fuel gas flow path 42 extends in the direction of arrow C on the surface 14 a of the first separator 14 facing the electrolyte membrane / electrode structure 10 with a resin frame.

  On the inlet side (upper end side) of the fuel gas flow path 42, a buffer region 44a that contacts an inlet buffer portion 29a provided at the upper end edge of the surface 24as of the resin frame member 24 is provided. A plurality of inlet connection passages 46a are connected to the end of the buffer region 44a on the fuel gas inlet communication hole 34a side, and the inlet connection passages 46a communicate with the plurality of supply hole portions 48a.

  On the outlet side (lower end side) of the fuel gas flow path 42, a buffer region 44b is provided in which the outlet buffer portion 29b provided at the lower end edge of the surface 24as of the resin frame member 24 contacts. A discharge hole portion 48b communicates with an end portion of the buffer region 44b on the fuel gas outlet communication hole 34b side via a plurality of outlet connection paths 46b.

  As shown in FIG. 1, on the surface 14b side of the first separator 14, a plurality of inlet connection passages 50a communicating the supply holes 48a and the fuel gas inlet communication holes 34a, and the discharge holes 48b and the fuel gas outlets. A plurality of outlet connection paths 50b communicating with the communication holes 34b are provided. A cooling medium flow path 52 that communicates the cooling medium inlet communication hole 32a and the cooling medium outlet communication hole 32b is provided in the direction of arrow C on the surface 14b.

  As shown in FIG. 2, in the gas diffusion layer 20 b, a region overlapping the polymerization site 26 along the stacking direction is opposed to the fuel gas channel 42.

  As shown in FIGS. 1 and 2, the first seal member 54 is integrated with the surfaces 14 a and 14 b of the first separator 14 around the outer peripheral end portion of the first separator 14. The second seal member 56 is integrated with the surfaces 16 a and 16 b of the second separator 16 around the outer peripheral end of the second separator 16.

  As shown in FIG. 2, the first seal member 54 has a convex seal 54 a that contacts the second seal member 56, while the second seal member 56 constitutes the electrolyte membrane / electrode structure 10 with a resin frame. And a convex seal 56a that contacts the resin frame member 24. The first seal member 54 and the second seal member 56 have a flat seal provided in a thin shape along the separator surface.

  For the first seal member 54 and the second seal member 56, for example, EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber or the like, cushion material Or a packing material is used.

  Next, a method for producing the resin frame-attached electrolyte membrane / electrode structure 10 will be described below.

  First, as shown in FIGS. 6 and 7, an electrolyte membrane / electrode structure 10a which is a step MEA is manufactured. Specifically, electrode catalyst layers 20 a and 22 a are applied to both surfaces 18 a and 18 b of the solid polymer electrolyte membrane 18. A gas diffusion layer 20b is disposed on the surface 18a side of the solid polymer electrolyte membrane 18, that is, the electrode catalyst layer 20a, and at the surface 18b of the solid polymer electrolyte membrane 18, that is, on the electrode catalyst layer 22a. A gas diffusion layer 22b is disposed. The electrolyte membrane / electrode structure 10a is manufactured by stacking these together and subjecting them to hot pressing.

  On the other hand, the resin frame member 24 is molded in advance by an injection molding machine (not shown). As shown in FIG. 7, the resin frame member 24 is formed into a frame shape and is provided with a thin inner peripheral bulging portion 24 a. At both ends in the longitudinal direction of the resin frame member 24, a plurality of protrusions are formed on both surfaces, thereby providing inlet buffer portions 29a and 29c and outlet buffer portions 29b and 29d.

  Next, as shown in FIG. 6, in the electrolyte membrane / electrode structure 10a, an adhesive is applied to the outer peripheral edge of the solid polymer electrolyte membrane 18 and the outer peripheral edge of the electrode catalyst layer 22a exposed from the outer periphery of the cathode electrode 22 to the outside. Layer 27 is provided. Then, the resin frame member 24 and the electrolyte membrane / electrode structure 10a are aligned.

  In the resin frame member 24, the inner peripheral bulging portion 24a is disposed on the cathode electrode 22 side, the adhesive layer 27 is heated and melted (hot melted), and a load (press or the like) is applied. For this reason, the inner peripheral bulging portion 24a and the solid polymer electrolyte membrane 18 are bonded.

  Further, a resin member 28aa for forming the resin impregnated portion 28a is prepared on the anode electrode 20 side, while a resin member 28bb for forming the resin impregnated portion 28b is prepared on the cathode electrode 22 side. . The resin members 28aa and 28bb have a frame shape (frame shape), and are made of the same material as the resin frame member 24, for example. The resin members 28aa and 28bb may be integrated with the resin frame member 24 in advance.

  Therefore, the resin members 28aa and 28bb are heated in a state where the resin members 28aa and 28bb are arranged and a load is applied to the electrolyte membrane / electrode structure 10a and the resin frame member 24. As the heating method, laser welding, infrared welding, impulse welding, or the like is employed.

  Therefore, the resin members 28aa and 28bb are heated and melted, and the resin member 28aa is impregnated across the gas diffusion layer 20b and the resin frame member 24 constituting the anode electrode 20. Further, the resin member 28bb is impregnated across the gas diffusion layer 22b and the resin frame member 24 constituting the cathode electrode 22. Thereby, as shown in FIG. 2, the electrolyte membrane and electrode structure 10 with a resin frame is manufactured.

  The electrolyte membrane / electrode structure 10 with a resin frame is sandwiched between a first separator 14 and a second separator 16 to form a fuel cell 12. A predetermined number of fuel cells 12 are stacked to constitute a fuel cell stack, and a clamping load is applied between end plates (not shown).

  The operation of the fuel cell 12 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.

  For this reason, the oxidant gas is introduced into the oxidant gas flow path 36 of the second separator 16 from the oxidant gas inlet communication hole 30a, and moves in the direction of arrow C to the cathode electrode 22 of the electrolyte membrane / electrode structure 10a. Supplied. On the other hand, the fuel gas is introduced into the fuel gas flow path 42 of the first separator 14 from the fuel gas inlet communication hole 34a through the supply hole 48a. The fuel gas moves in the direction of arrow C along the fuel gas flow path 42 and is supplied to the anode electrode 20 of the electrolyte membrane / electrode structure 10a.

  Accordingly, in each electrolyte membrane / electrode structure 10a, the oxidant gas supplied to the cathode electrode 22 and the fuel gas supplied to the anode electrode 20 are consumed by an electrochemical reaction in the electrode catalyst layer to generate power. Done.

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

  The cooling medium supplied to the cooling medium inlet communication hole 32 a is introduced into the cooling medium flow path 52 between the first separator 14 and the second separator 16 and then flows in the direction of arrow C. The cooling medium is discharged from the cooling medium outlet communication hole 32b after the electrolyte membrane / electrode structure 10a is cooled.

  In this case, in this embodiment, as shown in FIGS. 2 and 3, the outer peripheral end 22ae of the electrode catalyst layer 22a constituting the cathode electrode 22 protrudes outward from the outer peripheral end 22be of the gas diffusion layer 22b. In addition, the inner peripheral bulging portion 24a of the resin frame member 24 has a polymerization site 26 that overlaps with the outer peripheral end 22ae of the electrode catalyst layer 22a along the stacking direction.

  For this reason, even if a gap S1 is formed between the outer peripheral end portion 22be of the gas diffusion layer 22b and the inner peripheral end portion 24ae of the inner peripheral bulging portion 24a of the resin frame member 24, the solid height is increased from the gap S1. The oxidant gas does not contact the molecular electrolyte membrane 18. Therefore, the end portion of the solid polymer electrolyte membrane 18 is deteriorated by hydrogen peroxide generated by the reaction between the oxidant gas and the fuel gas or by hydroxy radicals (.OH) generated using the hydrogen peroxide as a precursor. The effect that this is effectively and reliably suppressed is obtained.

  Further, in this embodiment, the resin impregnated portion 28a formed in a frame shape over the entire circumference of the gas diffusion layer 20b constituting the anode electrode 20 has an inner peripheral end 28ae along the stacking direction outside the polymerization site 26. Are spaced apart by a length L3. Moreover, as shown in FIG. 2, in the electrode catalyst layer 20 a, the region overlapping with the polymerization site 26 faces the fuel gas flow path 42 that supplies the fuel gas along the anode electrode 20.

  Thereby, the oxidant gas does not stay in the polymerization site 26 of the solid polymer electrolyte membrane 18, and the oxidant gas can be smoothly and reliably discharged from the gas diffusion layer 20b to the fuel gas flow path 42. For this reason, the reaction between the oxidant gas and the fuel gas is not induced at the end of the solid polymer electrolyte membrane 18, and the deterioration of the solid polymer electrolyte membrane 18 can be suppressed as much as possible. Become.

DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane / electrode structure with resin frame 10a ... Electrolyte membrane / electrode structure 12 ... Fuel cell 14, 16 ... Separator 18 ... Solid polymer electrolyte membrane 20 ... Anode electrode 20a, 22a ... Electrode catalyst layer 20b, 22b ... Gas diffusion layer 22 ... Cathode electrodes 22ae, 22be ... Outer peripheral end 24 ... Resin frame member 24a ... Inner peripheral bulge 24ae ... Inner peripheral end 27 ... Adhesive layers 28a, 28b ... Resin impregnated portions 29a, 29c ... Inlet Buffer part 29b, 29d ... Outlet buffer 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 passage 42 ... Fuel gas passage 52 ... Cooling medium passage 54, 56 ... Seal member

Claims (3)

An anode electrode having an anode catalyst layer and an anode diffusion layer is provided on one surface of the solid polymer electrolyte membrane, and a cathode having a cathode catalyst layer and a cathode diffusion layer on the other surface of the solid polymer electrolyte membrane. An electrode is provided, and an outer peripheral end portion of the anode catalyst layer has an electrolyte membrane / electrode structure protruding outward from an outer peripheral end portion of the cathode catalyst layer;
A resin frame member provided around the outer periphery of the solid polymer electrolyte membrane;
An electrolyte membrane / electrode structure with a resin frame for a fuel cell comprising:
The outer peripheral end of the cathode catalyst layer protrudes outward from the outer peripheral end of the cathode diffusion layer, and
The resin frame member has an inner peripheral bulging portion that protrudes toward the outer peripheral side of the cathode electrode and contacts the outer peripheral edge of the solid polymer electrolyte membrane,
The electrolyte membrane / electrode structure with a fuel frame for a fuel cell, wherein the inner peripheral bulge has a polymerization site overlapping with an outer peripheral edge of the cathode catalyst layer. In the electrolyte membrane / electrode structure with a resin frame for a fuel cell according to claim 1, a resin impregnated portion integrated with the resin frame member is provided on an outer peripheral edge portion of the anode diffusion layer,
An electrolyte membrane / electrode structure with a resin frame for a fuel cell, wherein an inner peripheral end of the resin-impregnated portion is located outside the polymerization site along a stacking direction with the solid polymer electrolyte membrane.   3. The electrolyte membrane / electrode structure with a resin frame for a fuel cell according to claim 1, wherein the anode catalyst layer has a region overlapping with the polymerization site along a stacking direction with the solid polymer electrolyte membrane. An electrolyte membrane / electrode structure with a resin frame for a fuel cell, which faces a fuel gas flow path for supplying fuel gas along the electrode.

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