JP2013206599A - Method of manufacturing electrolyte membrane/electrode structure for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enable a moisture content in an electrode plane to be uniformly controlled with a simple process, and satisfactorily improving power generation performance.SOLUTION: In an electrolyte membrane/electrode structure 10, a solid polymer electrolyte membrane 34 is held between a cathode electrode 36 and an anode electrode 38. A cathode electrode catalyst layer 36a and a cathode side diffusion layer 36b are provided in the cathode electrode 36, and on the other hand, an anode electrode diffusion layer 38a and an anode side diffusion layer 38b are provided in the anode electrode 38. The method of manufacturing the electrolyte membrane/electrode structure has a step for applying a press load to a location corresponding to the upstream side of the gas passage of the cathode side diffusion layer 36b, and a step for integration in which the cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are interposed between the cathode side diffusion layer 36b and the anode side diffusion layer 38b, the solid polymer electrolyte membrane 34 is held between them, and under this condition, hot press is performed by applying a load lighter than the press load to integrate them.

Description

  In the present invention, a cathode electrode catalyst layer and a cathode side diffusion layer are provided on one surface of a solid polymer electrolyte membrane, and an anode electrode catalyst layer and an anode side diffusion layer are provided on the other surface of the solid polymer electrolyte membrane. The present invention relates to a method for producing an electrolyte membrane / electrode structure 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 comprises an electrolyte membrane / electrode structure 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 ( MEA) is sandwiched between separators (bipolar plates). Usually, a fuel cell stack in which a predetermined number of fuel cells are stacked is used as, for example, an in-vehicle fuel cell stack.

  In this type of fuel cell, it is necessary to keep the solid polymer electrolyte membrane moisturized in order to ensure good ion conductivity. Therefore, a method is employed in which an oxidizing gas (for example, air) or a fuel gas (for example, hydrogen gas), which is a reactive gas, is humidified and supplied to the fuel cell.

  At this time, moisture for humidification may be liquefied without being absorbed by the solid polymer electrolyte membrane and may stay in the reaction gas flow path. On the other hand, in the fuel cell, generated water is generated at the cathode electrode due to the power generation reaction. For this reason, in the reaction gas channel (particularly, the oxidant gas channel), the humidity environment of the solid polymer electrolyte membrane is different from the upstream side toward the downstream side, and the power generation performance may be reduced.

  Thus, for example, a fuel cell disclosed in Patent Document 1 is known. As shown in FIG. 10, the fuel cell includes a solid polymer electrolyte membrane 1, a fuel electrode 2 provided on one side in the thickness direction of the solid polymer electrolyte membrane 1, to which a fuel gas is supplied, and the solid high electrolyte membrane. It is provided on the other side of the molecular electrolyte membrane 1 in the thickness direction and has an oxidant electrode 3 to which an oxidant gas is supplied.

  One or both of the fuel electrode 2 and the oxidant electrode 3 have gas diffusion layers 2a and 3a that diffuse gas and have conductivity. The air permeability in the downstream region of the gas diffusion layers 2a and 3a is set to be relatively larger than the air permeability in the upstream region of the gas diffusion layers 2a and 3a. The gas diffusion layers 2a and 3a are configured by using an accumulation body in which carbon short fibers having conductivity are accumulated in a sheet shape as a base material.

  In the gas diffusion layers 2a and 3a, the structure continuously changes from dense to sparse from the gas channel upstream side to the gas channel downstream side. For this reason, the air permeability in the downstream region of the gas diffusion layers 2a and 3a is set to be relatively larger than the air permeability in the upstream region of the gas diffusion layers 2a and 3a.

JP 2004-273392 A

  By the way, in said gas diffusion layer 2a, 3a, it is necessary to change a material composition toward a gas flow path downstream from a gas flow path upstream. For this reason, there is a problem that the configuration becomes complicated and the cost increases.

  The present invention solves this type of problem, and can easily and economically control the amount of water in the electrode surface uniformly, and can improve the power generation performance satisfactorily. An object of the present invention is to provide a method for producing an electrolyte membrane / electrode structure.

  In the present invention, a cathode electrode catalyst layer and a cathode side diffusion layer are provided on one surface of a solid polymer electrolyte membrane, and an anode electrode catalyst layer and an anode side diffusion layer are provided on the other surface of the solid polymer electrolyte membrane. The present invention relates to a method for producing an electrolyte membrane / electrode structure for a fuel cell.

  This manufacturing method includes a step of applying a press load to a portion of the cathode side diffusion layer corresponding to the upstream side of the cathode gas flow path, and a cathode electrode catalyst layer and a cathode electrode diffusion layer between the cathode side diffusion layer and the anode side diffusion layer. And a step of integrating by applying a hot press with a load smaller than the press load in a state where the solid polymer electrolyte membrane is sandwiched with an anode electrode catalyst layer interposed therebetween.

  In addition, this manufacturing method integrates each surface of the solid polymer electrolyte membrane with the cathode electrode catalyst layer and the anode electrode catalyst layer by applying a load by hot pressing, and supports the upstream side of the cathode gas flow path. Between the cathode side diffusion layer and the anode side diffusion layer, the step of setting the load of the site to be larger than the load of the part corresponding to the downstream side of the cathode gas flow path, and the anode electrode catalyst layer and the anode A step of applying a load and performing a hot press in a state where the solid polymer electrolyte membrane with the electrode catalyst layer integrated is sandwiched.

  Further, the manufacturing method includes a step of joining and integrating each surface of the solid polymer electrolyte membrane with the cathode electrode catalyst layer and the anode electrode catalyst layer, and the cathode side diffusion layer and the anode side diffusion layer. In the state where the solid polymer electrolyte membrane in which the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated is sandwiched between the cathode electrode catalyst layer and the anode electrode catalyst layer, by applying a hot press with a load, the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated. A step of setting a load of a portion corresponding to the upstream side of the passage to be larger than a load of a portion corresponding to the downstream side of the cathode gas flow path.

  According to the present invention, a press load is applied to a portion corresponding to the upstream side of the cathode gas flow path of the cathode side diffusion layer (hereinafter also referred to as the diffusion layer upstream portion). For this reason, the upstream portion of the diffusion layer is compressed to reduce water vapor permeability and improve water retention of the solid polymer electrolyte membrane. On the other hand, the portion corresponding to the cathode gas diffusion layer flow path downstream side of the cathode side diffusion layer (hereinafter also referred to as the diffusion layer downstream portion) retains water vapor permeability. As a result, it is not necessary to change the material, and it is only necessary to apply a load. Thus, the amount of water in the electrode surface can be controlled uniformly by a simple process, and the power generation performance is improved and stable. Continuous operation is possible.

  Further, according to the present invention, each surface of the solid polymer electrolyte membrane and the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated by hot pressing while applying a load, and on the upstream side of the cathode gas flow path. The load of the corresponding portion (hereinafter also referred to as the upstream portion of the catalyst layer) is set larger than the load of the portion corresponding to the downstream side of the cathode gas flow path (hereinafter also referred to as the downstream portion of the catalyst layer).

  Therefore, the upstream portion of the catalyst layer is compressed to reduce water vapor permeability and improve water retention of the solid polymer electrolyte membrane. On the other hand, the water vapor permeability is maintained in the downstream portion of the diffusion layer. For this reason, since it is not necessary to change the material and only the application of a load is required, the amount of moisture in the electrode surface can be uniformly controlled with a simple process, and the power generation performance is improved and stable. Continuous operation is possible.

  Furthermore, according to the present invention, a load is applied in a state where the solid polymer electrolyte membrane in which the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated is sandwiched between the cathode side diffusion layer and the anode side diffusion layer. By applying and hot-pressing, the load is integrated, and the load corresponding to the upstream side of the cathode gas channel (hereinafter also referred to as the electrode upstream site) corresponds to the downstream side of the cathode gas channel. It is set larger than the load of the part (hereinafter also referred to as the electrode downstream part).

  As a result, the upstream portion of the electrode is compressed and water vapor permeability is lowered, and the water retention of the solid polymer electrolyte membrane is improved. On the other hand, the water vapor permeability is maintained in the electrode downstream portion. Therefore, it is not necessary to change the material, and only the application of a load is required. Therefore, the amount of moisture in the electrode surface can be uniformly controlled with a simple process, and the power generation performance is improved and stable continuous. Driving becomes possible.

It is a principal part disassembled perspective explanatory view of a polymer electrolyte fuel cell in which an electrolyte membrane / electrode structure to which a manufacturing method according to the present invention is applied is incorporated. It is the II-II sectional view taken on the line of the said fuel cell in FIG. It is explanatory drawing at the time of manufacturing CCM in the manufacturing method which concerns on the 1st Embodiment of this invention. It is explanatory drawing at the time of performing a press process to a cathode side diffusion layer. It is explanatory drawing when the said cathode side diffusion layer and an anode side diffusion layer are joined to the said CCM. It is explanatory drawing of the water concentration in the oxidant gas flow path of 1st Embodiment and a comparative example. It is explanatory drawing of another press apparatus. It is explanatory drawing at the time of performing a press process to CCM in the manufacturing method which concerns on the 2nd Embodiment of this invention. In the manufacturing method which concerns on the 3rd Embodiment of this invention, it is explanatory drawing at the time of performing a press process to an electrolyte membrane and electrode structure. 2 is an explanatory diagram of a fuel cell disclosed in Patent Document 1. FIG.

  As shown in FIGS. 1 and 2, an electrolyte membrane / electrode structure 10 to which the manufacturing method according to the present invention is applied is incorporated into a polymer electrolyte fuel cell 12. The fuel cell 12 is configured by sandwiching the electrolyte membrane / electrode structure 10 between a first separator 14 and a second separator 16. For example, a plurality of fuel cells 12 are stacked and mounted on a fuel cell electric vehicle (not shown).

  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 plated steel plate, or a vertically long metal plate obtained by performing a surface treatment for corrosion prevention on the metal surface.

  The first separator 14 and the second separator 16 have a rectangular planar shape, and are formed into a concavo-convex shape by pressing a metal thin plate into a wave shape. In addition, you may comprise the 1st separator 14 and the 2nd separator 16 with a carbon separator, for example.

  As shown in FIG. 1, an oxidant gas, for example, an oxygen-containing gas is supplied to the upper edge of the fuel cell 12 in the arrow C direction (vertical direction) so as to communicate with each other in the arrow A direction that is the stacking direction. An oxidant gas inlet communication hole 18a for supplying a coolant, a cooling medium inlet communication hole 20a for supplying a cooling medium, and a fuel gas inlet communication hole 22a for supplying a fuel gas, for example, a hydrogen-containing gas, are provided in the direction of arrow B. Arranged and provided.

  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 22b for discharging the fuel gas, and the cooling medium outlet communication hole 20b for discharging the cooling medium. And oxidant gas outlet communication holes 18b for discharging the oxidant gas are arranged in the direction of arrow B.

  An oxidant gas flow path 24 communicating with the oxidant gas inlet communication hole 18a and the oxidant gas outlet communication hole 18b is provided on the surface 14a of the first separator 14 facing the electrolyte membrane / electrode structure 10 along the vertical direction. Provided.

  A fuel gas passage 26 communicating with the fuel gas inlet communication hole 22a and the fuel gas outlet communication hole 22b is provided along the vertical direction on the surface 16a of the second separator 16 facing the electrolyte membrane / electrode structure 10. .

  A cooling medium that connects the cooling medium inlet communication hole 20a and the cooling medium outlet communication hole 20b between the surface 14b of the first separator 14 and the surface 16b of the second separator 16 constituting the fuel cells 12 adjacent to each other. A flow path 28 is provided along the vertical direction.

  The first seal member 30 is integrally or individually provided on the surfaces 14 a and 14 b of the first separator 14, and the second seal member 32 is integrally formed on the surfaces 16 a and 16 b of the second separator 16. Or it is provided separately. The first seal member 30 and the second seal member 32 are, for example, EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroplane, or acrylic rubber, or a cushion material. Or use packing material.

  As shown in FIG. 2, the electrolyte membrane / electrode structure 10 includes a solid polymer electrolyte membrane 34, and a cathode electrode 36 and an anode electrode 38 that sandwich the solid polymer electrolyte membrane 34.

  The cathode electrode 36 and the anode electrode 38 have the same surface area (outer dimension), and the solid polymer electrolyte membrane 34 has a larger surface area (outer dimension) than the cathode electrode 36 and the anode electrode 38. The outer peripheral end of the solid polymer electrolyte membrane 34 extends outward from the ends of the cathode electrode 36 and the anode electrode 38. The solid polymer electrolyte membrane 34 may have the same surface area as the cathode electrode 36 or the anode electrode 38. Further, the cathode electrode 36 and the anode electrode 38 may have different surface areas.

  The cathode electrode 36 includes a cathode electrode catalyst layer 36a joined to one surface 34a of the solid polymer electrolyte membrane 34, and a cathode side diffusion layer (porous diffusion layer) 36b laminated on the cathode electrode catalyst layer 36a. Provide. The cathode side diffusion layer 36b is made of carbon paper, carbon cloth, porous metal, etc., and the cathode electrode catalyst layer 36a has porous carbon particles carrying platinum alloy on the surface thereof on the surface of the cathode side diffusion layer 36b. It is uniformly applied and formed. The cathode electrode catalyst layer 36 a is formed on the surface 34 a of the solid polymer electrolyte membrane 34.

  The anode electrode 38 includes an anode electrode catalyst layer 38a joined to the other surface 34b of the solid polymer electrolyte membrane 34, and an anode side diffusion layer (porous diffusion layer) 38b laminated on the anode electrode catalyst layer 38a. Provide. The anode side diffusion layer 38b is made of carbon paper, carbon cloth, porous metal, etc., and the anode electrode catalyst layer 38a has porous carbon particles carrying a platinum alloy on the surface thereof on the surface of the anode side diffusion layer 38b. It is uniformly applied and formed. The anode electrode catalyst layer 38 a is formed on the surface 34 b of the solid polymer electrolyte membrane 34.

  In the fuel cell 12 configured as described above, a method for manufacturing the electrolyte membrane / electrode structure 10 according to the first embodiment of the present invention will be described below.

  First, as shown in FIG. 3, for example, a cathode electrode catalyst layer 36a is applied to the surface 34a of a solid polymer electrolyte membrane 34 which is a fluorine ion exchange membrane or a hydrocarbon ion exchange membrane by transfer or a coater. At the same time, an anode electrode catalyst layer 38a is applied to the surface 34b of the solid polymer electrolyte membrane 34 by transfer or a coater.

  The cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are formed, for example, by forming catalyst particles in which platinum particles are supported on carbon black, and preparing a solution containing a polymer electrolyte as an ion conductive binder. The catalyst paste is prepared by uniformly mixing the catalyst particles therein. The cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are hot-pressed on the surfaces 34a and 34b of the solid polymer electrolyte membrane 34, whereby a CCM (ion exchange membrane with catalyst on both surfaces) 40 is formed.

  On the other hand, the cathode side diffusion layer 36b constituting the cathode electrode 36 is subjected to a crushing process via a press device 42 as shown in FIG. The pressing device 42 constitutes a base portion, and corresponds to the first plate-like jig 44 on which the cathode side diffusion layer 36b is placed and the upstream side of the oxidant gas flow path 24 on the cathode side diffusion layer 36b. A second plate-like jig 46 disposed in a portion corresponding to the diffusion layer upstream portion 36bu which is a portion to be pressed, and a pressure roller 48.

  The pressure roller 48 pressurizes the second plate-shaped jig 46 with the cathode side diffusion layer 36b sandwiched between the first plate-shaped jig 44 and the second plate-shaped jig 46. Roll. For this reason, a press load is applied to the diffusion layer upstream portion 36bu of the cathode side diffusion layer 36b, and a compression load is applied to the diffusion layer upstream portion 36bu of the cathode side diffusion layer 36b to form a crush.

  The press load may be adjusted continuously or stepwise using two or more plate jigs so as to decrease from the upstream side to the downstream side of the cathode side diffusion layer 36b. Instead of the pressure roller 48, a press device that pressurizes the second plate-shaped jig 46 toward the first plate-shaped jig 44 may be used.

  Next, as shown in FIG. 5, the cathode side diffusion layer 36 b and the anode side diffusion layer 38 b are disposed with the CCM 40 interposed therebetween. The cathode side diffusion layer 36b is joined to the cathode electrode catalyst layer 36a, while the anode side diffusion layer 38b is joined to the anode electrode catalyst layer 38a. In this state, a load smaller than the above-described pressing load by the pressing device 42 (a load capable of maintaining the crushing distribution state of the cathode-side diffusion layer 36b and the anode-side diffusion layer 38b) is uniformly applied to the entire surface. As a result, the electrolyte membrane / electrode structure 10 is integrated. The anode side diffusion layer 38b may also apply a press load to the upstream corresponding portion.

  Further, the first separator 14 is disposed on one side of the electrolyte membrane / electrode structure 10, and the second separator 16 is disposed on the other side of the electrolyte membrane / electrode structure 10. In this state, a tightening load is applied between the first separator 14 and the second separator 16 to assemble the fuel cell 12 (see FIG. 1).

  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 18a, and a fuel gas such as a hydrogen-containing gas is supplied to the fuel gas inlet communication hole 22a. Further, a cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 20a.

  For this reason, the oxidant gas is introduced into the oxidant gas flow path 24 of the first separator 14 from the oxidant gas inlet communication hole 18a. The oxidant gas is supplied to the cathode electrode 36 constituting the electrolyte membrane / electrode structure 10 while moving downward in the direction of arrow C.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 26 of the second separator 16 from the fuel gas inlet communication hole 22a. This fuel gas is supplied to the anode electrode 38 constituting the electrolyte membrane / electrode structure 10 while moving downward in the direction of arrow C.

  Therefore, in the electrolyte membrane / electrode structure 10, the oxidizing gas supplied to the cathode electrode 36 and the fuel gas supplied to the anode electrode 38 are electrochemically generated in the cathode electrode catalyst layer 36 a and the anode electrode catalyst layer 38 a. It is consumed by the reaction and power is generated.

  Next, the oxidant gas consumed by being supplied to the cathode electrode 36 is discharged in the direction of arrow A along the oxidant gas outlet communication hole 18b. On the other hand, the fuel gas consumed by being supplied to the anode electrode 38 is discharged in the direction of arrow A along the fuel gas outlet communication hole 22b.

  The cooling medium supplied to the cooling medium inlet communication hole 20a is introduced into the cooling medium flow path 28 between the first and second separators 14 and 16, and flows downward in the direction of arrow C. The cooling medium is discharged to the cooling medium outlet communication hole 20b after the electrolyte membrane / electrode structure 10 is cooled.

  As described above, when the fuel cell 12 is operated, the oxidant gas flow path 24 is introduced with the oxidant gas humidified before being supplied by the humidifier (not shown) and generated by the reaction. Water is generated and the generated water tends to stay on the downstream side of the oxidant gas flow path 24 (oxidant gas outlet communication hole 18b side).

  In this case, in the first embodiment, a press load is applied in advance to the diffusion layer upstream portion 36 bu adjacent to the oxidant gas inlet communication hole 18 a of the cathode side diffusion layer 36 b via the press device 42. For this reason, the diffusion layer upstream portion 36bu is crushed, the water vapor permeability is lowered, the water retention of the solid polymer electrolyte membrane 34 is improved, and the water content is increased. On the other hand, the downstream portion of the cathode side diffusion layer 36b (in the vicinity of the oxidant gas outlet communication hole 18b) does not have a press load and maintains water vapor permeability.

  For this reason, as shown in FIG. 6, in the first embodiment, the moisture concentration in the cathode side diffusion layer 36 b can be made uniform from the inlet side to the outlet side of the oxidant gas flow path 24. . On the other hand, in the comparative example in which no press load is applied, the moisture concentration is low on the inlet side of the oxidant gas flow path 24 and is easily dried.

  Thereby, in the first embodiment, since it is not necessary to change the material and only the load is applied, the amount of moisture in the electrode surface can be uniformly controlled by a simple process, and the power generation performance is good. In addition, there is an effect that stable continuous operation is possible and the durability of the fuel cell 12 is easily improved.

  In the first embodiment, the press device 42 shown in FIG. 4 is used, but the present invention is not limited to this. For example, in the press device 50 shown in FIG. 7, a tapered second plate-like jig 52 is used instead of the second plate-like jig 46.

  The second plate-like jig 52 has a taper shape in which the plate pressure continuously increases toward the diffusion layer upstream portion 36bu of the cathode-side diffusion layer 36b. 48 is pressed and moved in the direction of the arrow. Therefore, the cathode side diffusion layer 36b is subjected to a pressurizing process in which the press load continuously increases from the oxidant gas flow path outlet side toward the oxidant gas flow path inlet side. Note that the load may be changed by changing the rotation center of the pressing device 50 to the thickness method of the electrolyte membrane / electrode structure 10.

  Thereby, the cathode side diffusion layer 36b press-processed by the press apparatus 50 has the same effect as the cathode-side diffusion layer 36b press-processed by the press apparatus 42.

  Further, in place of the second plate-shaped jig 46, the second plate-shaped jig covering the entire surface of the cathode side diffusion layer 36 b is used similarly to the first plate-shaped jig 44, and the pressure applied by the pressure roller 48 is applied. Further, it may be configured to be continuously or intermittently variable toward the diffusion layer upstream portion 36bu. The same applies to the second and third embodiments described below.

  Next, a method for manufacturing the electrolyte membrane / electrode structure 10 according to the second embodiment of the present invention will be described below.

  In the second embodiment, the cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are applied to the surfaces 34a and 34b of the solid polymer electrolyte membrane 34 by applying a load and integrated by hot pressing. At that time, as shown in FIG. 8, a press device 60 is used.

  The press device 60 includes a first plate-like jig 62 and a second plate-like jig 64. The 2nd plate-shaped jig | tool 64 is set to the dimension arrange | positioned at the catalyst layer upstream site | part 36au which is a site | part corresponding to the upstream of the oxidizing gas flow path 24 of the cathode electrode catalyst layer 36a.

  In the pressing device 60, a load is applied and hot pressing is performed with the cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a superimposed on the surfaces 34a and 34b of the solid polymer electrolyte membrane 34. At that time, the load of the catalyst layer upstream portion 36 au of the cathode electrode catalyst layer 36 a is set to be larger than the load of the catalyst layer downstream portion that is a portion corresponding to the downstream side of the oxidant gas flow path 24. Note that a smaller load may be applied to the downstream side than the upstream side.

  The cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are hot-pressed on the surfaces 34a and 34b of the solid polymer electrolyte membrane 34 by applying a load, whereby the CCM 40 is manufactured. The CCM 40 is further integrated with the electrolyte membrane / electrode structure by being hot-pressed with a load uniformly applied to the entire surface while being sandwiched between the cathode side diffusion layer 36b and the anode side diffusion layer 38b. The body 10 is manufactured.

  As described above, the load of the catalyst layer upstream portion 36au of the cathode electrode catalyst layer 36a is set to be larger than the load of the catalyst layer downstream portion, and the catalyst layer upstream portion 36au is compressed to reduce the water vapor permeability. . Therefore, water retention is improved on the oxidant gas inlet side of the solid polymer electrolyte membrane 34 corresponding to the catalyst layer upstream portion 36au, and drying can be satisfactorily suppressed.

  On the other hand, in the downstream portion of the catalyst layer, water vapor permeability is maintained and drainage performance is improved. For this reason, it is not necessary to change the material, and it is only necessary to apply a load. Therefore, with a simple configuration, the amount of water in the electrode surface can be controlled uniformly, and the dew condensation water is suppressed and stable and continuous. Therefore, the power generation performance is improved and the durability of the fuel cell 12 is easily improved.

  In the second embodiment, a press load that continuously changes may be applied to the entire surface of the cathode electrode catalyst layer 36a using the press device 50 shown in FIG.

  Next, a method for manufacturing the electrolyte membrane / electrode structure 10 according to the third embodiment of the present invention will be described below.

  In the third embodiment, first, as in the first embodiment, the cathode electrode catalyst layer 36a and the anode electrode catalyst layer 38a are integrated with the surfaces 34a, 34b of the solid polymer electrolyte membrane 34, and the CCM 40 Is manufactured (see FIG. 3).

  Then, with the CCM 40 sandwiched between the cathode side diffusion layer 36b and the anode side diffusion layer 38b, a hot press is performed by applying a load by the pressing device 70 shown in FIG.

  In the pressing device 70, a first plate-like jig 72 and a second plate-like jig 74 are provided, and the second plate-like jig 74 is a portion corresponding to the upstream side of the oxidant gas flow path 24. It arrange | positions at a certain electrode upstream part 76u, and applies a load to the said electrode upstream part 76u.

  The load of the electrode upstream portion 76u is set to be larger than the load of the electrode downstream portion 76d that is a portion corresponding to the downstream side of the oxidant gas flow path 24. Then, the electrolyte membrane / electrode structure 10 is manufactured by hot pressing.

  In the third embodiment, the electrode upstream portion 76u of the electrolyte membrane / electrode structure 10 is compressed to reduce water vapor permeability and improve water retention of the solid polymer electrolyte membrane 34. On the other hand, the water vapor permeability is maintained in the electrode downstream portion 76d.

  Therefore, with the simple configuration, it is possible to uniformly control the amount of water in the electrode surface, and the same effects as those in the first and second embodiments described above can be obtained, for example, the power generation performance can be improved satisfactorily. In the third embodiment, a press device 50 shown in FIG. 7 can also be used.

DESCRIPTION OF SYMBOLS 10 ... Electrolyte membrane and electrode structure 12 ... Fuel cell 14, 16 ... Separator 18a ... Oxidant gas inlet communication hole 18b ... Oxidant gas outlet communication hole 20a ... Cooling medium inlet communication hole 20b ... Cooling medium outlet communication hole 22a ... Fuel Gas inlet communication hole 22b ... Fuel gas outlet communication hole 24 ... Oxidant gas flow path 26 ... Fuel gas flow path 28 ... Cooling medium flow path 34 ... Solid polymer electrolyte membrane 36 ... Cathode electrode 36a ... Cathode electrode catalyst layer 36au ... Catalyst Layer upstream part 36b ... Cathode side diffusion layer 36bu ... Diffusion layer upstream part 38 ... Anode electrode 38a ... Anode electrode catalyst layer 38b ... Anode side diffusion layer 40 ... CCM
42, 60, 70 ... press device 76u ... upstream portion of electrode

Claims (3)

A fuel in which a cathode electrode catalyst layer and a cathode side diffusion layer are provided on one surface of the solid polymer electrolyte membrane, and an anode electrode catalyst layer and an anode side diffusion layer are provided on the other surface of the solid polymer electrolyte membrane A method for producing an electrolyte membrane / electrode structure for a battery,
Applying a press load to a portion corresponding to the upstream side of the cathode gas flow path of the cathode side diffusion layer;
In a state where the solid polymer electrolyte membrane is sandwiched between the cathode side diffusion layer and the anode side diffusion layer with the cathode electrode catalyst layer and the anode electrode catalyst layer interposed therebetween, than the press load. By applying a small load and performing hot pressing,
A method for producing an electrolyte membrane / electrode structure for a fuel cell, comprising: A fuel in which a cathode electrode catalyst layer and a cathode side diffusion layer are provided on one surface of the solid polymer electrolyte membrane, and an anode electrode catalyst layer and an anode side diffusion layer are provided on the other surface of the solid polymer electrolyte membrane A method for producing an electrolyte membrane / electrode structure for a battery,
Each surface of the solid polymer electrolyte membrane and the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated by hot pressing with a load, and the load corresponding to the upstream side of the cathode gas flow path Is set larger than the load of the portion corresponding to the downstream side of the cathode gas flow path,
A load is applied in a state where the solid polymer electrolyte membrane in which the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated is sandwiched between the cathode side diffusion layer and the anode side diffusion layer. By performing hot pressing, the process of integrating,
A method for producing an electrolyte membrane / electrode structure for a fuel cell, comprising: A fuel in which a cathode electrode catalyst layer and a cathode side diffusion layer are provided on one surface of the solid polymer electrolyte membrane, and an anode electrode catalyst layer and an anode side diffusion layer are provided on the other surface of the solid polymer electrolyte membrane A method for producing an electrolyte membrane / electrode structure for a battery,
Bonding and integrating each surface of the solid polymer electrolyte membrane with the cathode electrode catalyst layer and the anode electrode catalyst layer;
A load is applied in a state where the solid polymer electrolyte membrane in which the cathode electrode catalyst layer and the anode electrode catalyst layer are integrated is sandwiched between the cathode side diffusion layer and the anode side diffusion layer. By integrating by hot pressing, and setting the load of the portion corresponding to the upstream side of the cathode gas flow path larger than the load of the portion corresponding to the downstream side of the cathode gas flow path;
A method for producing an electrolyte membrane / electrode structure for a fuel cell, comprising:

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