JP2018078003A - Manufacturing method of fuel cell - Google Patents

Abstract

[PROBLEMS] To suppress a decrease in strength of an electrolyte membrane. A cathode in which a cathode catalyst layer and a cathode gas diffusion layer are sandwiched between one surface of an electrolyte membrane and a non-contact portion that does not contact a contact portion contacting the cathode gas diffusion layer is repeated in a first direction. A step of disposing the side separator 18c and disposing the flat plate member 50 having a flat surface on the other surface of the electrolyte membrane; and a step of compressing and joining the electrolyte membrane, the cathode catalyst layer, and the cathode gas diffusion layer with the cathode side separator and the flat plate member. And a non-contact portion 46 that is not in contact with the contact portion 44 that is in contact with the anode gas diffusion layer with the anode catalyst layer 14a and the anode gas diffusion layer 16a interposed therebetween on the other surface of the electrolyte membrane is repeated in the first direction. The anode-side separator 18a having a length of the non-contact portion 46 shorter than that of the non-contact portion 42, and the cathode-side separator and the anode-side separator. Method for manufacturing a fuel cell comprising a step of compressing bonding quality film and the anode catalyst layer and an anode gas diffusion layer. [Selection] Figure 2

Description

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

  In an environment where drying and wetting are repeated, a dimensional change occurs in the electrolyte membrane. Thereby, durability of an electrolyte membrane will fall. Therefore, a fuel cell having excellent durability even under an environment where drying and wetting are repeated has been proposed (for example, Patent Document 1).

JP 2008-300317 A

  However, in Patent Document 1, a fuel cell is manufactured by pressing a pair of separators from both sides of a membrane electrode gas diffusion layer assembly including an electrolyte membrane, a catalyst layer, and a gas diffusion layer. In this case, bending deformation may occur in the electrolyte membrane due to the unevenness of the separator. When bending deformation occurs in the electrolyte membrane, stress tends to concentrate on a part of the electrolyte membrane, and the strength of the electrolyte membrane is reduced.

  This invention is made | formed in view of the said subject, and aims at suppressing the fall of the intensity | strength of an electrolyte membrane.

  The present invention provides a first gas passage through which a gas supplied to the first gas diffusion layer flows on one main surface of the electrolyte membrane with the first catalyst layer and the first gas diffusion layer interposed therebetween. A first non-contact portion that is not in contact with the first contact portion that is in contact with the first gas diffusion layer, which is either a first gas flow passage forming member that forms a gas or a simulated member that simulates the first gas flow passage formation member Arranging a first member repeated in a first direction, and disposing a flat plate member having a flat surface on the electrolyte membrane side on the other main surface of the electrolyte membrane; The electrolyte membrane, the first catalyst layer, and the first gas diffusion layer are compressed and joined by one member and the flat plate member, and after the first joining step, the electrolyte membrane On the other main surface, the second catalyst layer and the second gas diffusion layer are sandwiched between and supplied to the second gas diffusion layer. A second gas flow path forming member that forms a second gas flow path through which gas flows or a simulated member that simulates the second gas flow path forming member, and is in contact with the second gas diffusion layer A second non-contact portion that does not contact the portion is repeated in the first direction, and a second member in which the length of the second non-contact portion in the first direction is shorter than the length of the first non-contact portion is disposed A second disposing step, and compressing and joining the electrolyte membrane, the second catalyst layer, and the second gas diffusion layer with the first member and the second member. A method for manufacturing a fuel cell.

  According to the present invention, a decrease in the strength of the electrolyte membrane can be suppressed.

FIG. 1A to FIG. 1D are cross-sectional views showing a fuel cell manufacturing method according to a comparative example. FIG. 2 is a cross-sectional view of the fuel cell according to the first embodiment. FIGS. 3A to 3C are cross-sectional views (part 1) illustrating the method of manufacturing the fuel cell according to the first embodiment. 4A and 4B are cross-sectional views (part 2) illustrating the method of manufacturing the fuel cell according to the first embodiment. FIG. 5A to FIG. 5C are cross-sectional views illustrating another method for manufacturing the fuel cell according to the first embodiment. FIG. 6 is an exploded perspective view of a fuel cell including a gas flow path forming member made of expanded metal. FIG. 7 is an enlarged cross-sectional view of a part of a fuel cell including a gas flow path forming member made of expanded metal.

  Embodiments of the present invention will be described below with reference to the drawings.

  First, a comparative example will be described. FIG. 1A to FIG. 1D are cross-sectional views showing a fuel cell manufacturing method according to a comparative example. As shown in FIG. 1A, an anode catalyst layer 14a is formed on one main surface of the electrolyte membrane 12, and a cathode catalyst layer 14c is formed on the other main surface to form a membrane electrode assembly (MEA). ) 10 is formed.

  As shown in FIG. 1B, the anode gas diffusion layer 16a is disposed on the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side. Then, the MEA 10 and the anode gas diffusion layer 16a are compressed and joined by the pair of flat plate members 50. By compressing using the flat plate member 50, the joined body of the MEA 10 and the anode gas diffusion layer 16a has a substantially flat shape.

  As shown in FIG. 1C, the cathode gas diffusion layer 16c is disposed on the main surface of the cathode catalyst layer 14c opposite to the electrolyte membrane 12 side. Then, the MEA 10 and the cathode gas diffusion layer 16 c are compressed and joined by the pair of flat plate members 50. Thereby, a membrane electrode gas diffusion layer assembly (MEGA) 30 composed of the anode gas diffusion layer 16a, the MEA 10, and the cathode gas diffusion layer 16c is formed. By compressing using the flat plate member 50, the MEGA 30 has a substantially flat shape.

  As shown in FIG. 1D, the anode separator 18a is disposed on the main surface of the anode gas diffusion layer 16a opposite to the MEA 10 side. A cathode-side separator 18c is disposed on the main surface of the cathode gas diffusion layer 16c opposite to the MEA 10 side. Then, the anode side separator 18a is pressed toward the anode gas diffusion layer 16a, the cathode side separator 18c is pressed toward the cathode gas diffusion layer 16c, and the anode side separator 18a and the cathode side separator 18c are pressed against the anode gas diffusion layer 16a and the cathode. Bonded to the gas diffusion layer 16c. The cathode separator 18c has contact portions 40 that are in contact with the cathode gas diffusion layer 16c and non-contact portions 42 that are not in contact with the cathode gas diffusion layer 16c, which are alternately repeated in the first direction. Similarly, the anode separator 18a has contact parts 44 that are in contact with the anode gas diffusion layer 16a and non-contact parts 46 that are not in contact with the anode gas diffusion layer 16a, which are alternately repeated in the first direction. The length in the first direction of the contact part 40 and the non-contact part 42 of the cathode side separator 18c is longer than the length of the contact part 44 and the non-contact part 46 of the anode side separator 18a in the first direction. That is, the unevenness width of the cathode side separator 18c is larger than the unevenness width of the anode side separator 18a. As described above, the reason for increasing the length of the non-contact portion 42 of the cathode side separator 18c is to increase the flow rate of the oxidant gas by increasing the cathode gas flow path formed by the cathode side separator 18c. is there.

  In the fuel cell manufacturing method of the comparative example, the anode side separator 18a is pressed to the anode gas diffusion layer 16a side and the cathode side separator 18c is pressed to the cathode gas diffusion layer 16c side with respect to the flat MEGA 30. Since the unevenness of the anode side separator 18a is narrow, the MEGA 30 is unlikely to bend and deform due to the unevenness of the anode side separator 18a. However, since the unevenness of the cathode separator 18c is wide, the MEGA 30 may be bent and deformed by the unevenness of the cathode separator 18c as shown in FIG. When bending deformation occurs in the MEA 10, stress tends to concentrate on a part of the electrolyte membrane 12. For example, the stress due to the dimensional change of the electrolyte membrane 12 in an environment where drying and wetting are repeated tends to concentrate on a part of the electrolyte membrane 12. For this reason, the intensity | strength of the electrolyte membrane 12 will fall.

  Therefore, an embodiment in which bending deformation of the MEA 10 can be suppressed and a decrease in strength of the electrolyte membrane 12 can be suppressed will be described below.

  FIG. 2 is a cross-sectional view of the fuel cell according to the first embodiment. The fuel cell according to Example 1 is a polymer electrolyte fuel cell that generates power by receiving supply of a fuel gas (for example, hydrogen) and an oxidant gas (for example, air) as a reaction gas, and has a large number of single cells stacked. It has a stack structure. The fuel cell of Example 1 is mounted on, for example, a fuel cell vehicle or an electric vehicle.

  As shown in FIG. 2, in the fuel cell 100 of Example 1, the membrane electrode assembly (with the anode catalyst layer 14a bonded to one main surface of the electrolyte membrane 12 and the cathode catalyst layer 14c bonded to the other main surface) MEA (Membrane Electrode Assembly) 10 is provided. The MEA 10 has a substantially flat shape. The electrolyte membrane 12 is a solid polymer membrane formed of a fluorine-based resin material or a hydrocarbon-based resin material having a sulfonic acid group, and has good proton conductivity in a wet state. The anode catalyst layer 14a and the cathode catalyst layer 14c are solid polymers having carbon particles (for example, carbon black) supporting a catalyst (for example, platinum or a platinum-cobalt alloy) that promotes an electrochemical reaction, and a sulfonic acid group. And ionomers having good proton conductivity in the wet state.

  An anode gas diffusion layer 16a is joined to the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side. A cathode gas diffusion layer 16c is joined to the main surface of the cathode catalyst layer 14c opposite to the electrolyte membrane 12 side. MEA 10 and a pair of gas diffusion layers (anode gas diffusion layer 16a and cathode gas diffusion layer 16c) form a membrane electrode gas diffusion layer assembly (MEGA) 30. The anode gas diffusion layer 16a and the cathode gas diffusion layer 16c are formed of a member having gas permeability and electron conductivity, and are formed of a porous carbon member such as carbon cloth or carbon paper. The anode gas diffusion layer 16a and the cathode gas diffusion layer 16c are an adhesion layer for improving adhesion to the catalyst layer and / or a water repellent layer (MPL: Micro) for maintaining an appropriate amount of water in the MEA 10. Porous Layer) may be included. The adhesion layer and the water repellent layer may be formed of the same material as the gas diffusion layer.

  On both sides of the MEGA 30, a pair of separators (an anode side separator 18a and a cathode side separator 18c) that sandwich the MEGA 30 are provided. The anode-side separator 18a and the cathode-side separator 18c are formed of a member having gas barrier properties and electronic conductivity. For example, a carbon member such as dense carbon that has been made carbon impermeable by compressing carbon, or press-molded stainless steel It is formed of a metal member such as steel. The anode side separator 18a and the cathode side separator 18c have irregularities for forming a gas flow path through which the gas supplied to the anode gas diffusion layer 16a and the cathode gas diffusion layer 16c flows. The anode-side separator 18a forms an anode gas flow path 20a through which fuel gas flows between the anode gas diffusion layer 16a. The cathode separator 18c forms a cathode gas flow path 20c through which the oxidant gas flows, between the cathode gas diffusion layer 16c.

  The cathode separator 18c has contact portions 40 that are in contact with the cathode gas diffusion layer 16c and non-contact portions 42 that are not in contact with the cathode gas diffusion layer 16c, which are alternately repeated in the first direction. Similarly, the anode separator 18a has contact parts 44 that are in contact with the anode gas diffusion layer 16a and non-contact parts 46 that are not in contact with the anode gas diffusion layer 16a, which are alternately repeated in the first direction. The length in the first direction of the contact part 40 and the non-contact part 42 of the cathode side separator 18c is longer than the length of the contact part 44 and the non-contact part 46 of the anode side separator 18a in the first direction. That is, the length X1 in the first direction of the non-contact portion 42 of the cathode side separator 18c is longer than the length X2 in the first direction of the non-contact portion 46 of the anode side separator 18a. As described above, the length of the non-contact portion 42 of the cathode-side separator 18c is made longer than the length of the non-contact portion 46 of the anode-side separator 18a. This is to increase the amount of the agent gas.

  The main surface of the cathode gas diffusion layer 16c on the cathode side separator 18c side has an uneven shape corresponding to the unevenness of the cathode side separator 18c. On the other hand, the main surface of the anode gas diffusion layer 16a on the anode side separator 18a side is substantially flat. The main surfaces of the anode gas diffusion layer 16a and the cathode gas diffusion layer 16c on the MEA 10 side are also substantially flat.

  Next, a method for manufacturing the fuel cell of Example 1 will be described. 3 (a) to 4 (b) are cross-sectional views illustrating a method of manufacturing a fuel cell according to the first embodiment. As shown in FIG. 3A, the anode catalyst layer 14a and the cathode catalyst layer 14c are formed on both main surfaces of the electrolyte membrane 12 by spraying, for example, catalyst ink and drying. Thereby, the MEA 10 is formed. The anode catalyst layer 14a and the cathode catalyst layer 14c are not limited to being formed by spray coating, and may be formed by other generally used methods such as a transfer method and a die coater method.

  As shown in FIG. 3B, the cathode gas diffusion layer 16c is disposed on the main surface of the cathode catalyst layer 14c opposite to the electrolyte membrane 12 side. On the main surface opposite to the MEA 10 side of the cathode gas diffusion layer 16c, a cathode side separator 18c that forms a cathode gas flow path 20c through which an oxidant gas supplied to the cathode gas diffusion layer 16c flows is disposed. The cathode separator 18c has contact portions 40 that are in contact with the cathode gas diffusion layer 16c and non-contact portions 42 that are not in contact with the cathode gas diffusion layer 16c, which are alternately repeated in the first direction. Since the cathode gas flow path 20c is enlarged to increase the flow rate of the oxidant gas, the length of the non-contact portion 42 in the first direction is long. For example, the length of the contact part 40 in the first direction is 0.5 mm, and the length of the non-contact part 42 is 1.0 mm. On the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side, a flat plate member 50 having a flat surface facing the MEA 10 is disposed via a protective sheet (not shown) such as a Teflon (registered trademark) sheet. . The flat plate member 50 is made of, for example, metal, but may be made of other materials.

  As shown in FIG. 3C, the MEA 10 and the cathode gas diffusion layer 16 c are compressed and joined by press working using the cathode side separator 18 c and the flat plate member 50. The compression conditions are, for example, temperature: normal temperature to 150 ° C., pressure: 0.1 MPa to 3 MPa. At this time, since the width of the unevenness of the cathode side separator 18c is large and the length X1 in the first direction of the non-contact portion 42 of the cathode side separator 18c is long, the main side of the cathode gas diffusion layer 16c on the cathode side separator 18c side is large. The surface is deformed by the unevenness of the cathode-side separator 18c to become an uneven shape. On the other hand, since the MEA 10 is pressed by the flat plate member 50, deformation is suppressed and the flat shape remains unchanged. The cathode side separator 18c is joined to the main surface of the cathode gas diffusion layer 16c opposite to the MEA 10 side to form the cathode gas flow path 20c.

  As shown in FIG. 4A, the protective sheet and the flat plate member 50 are removed, and the anode gas diffusion layer 16a is disposed on the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side. On the main surface of the anode gas diffusion layer 16a opposite to the MEA 10 side, an anode separator 18a that forms an anode gas flow path 20a through which the fuel gas supplied to the anode gas diffusion layer 16a flows is disposed. The anode-side separator 18a has contact portions 44 that are in contact with the anode gas diffusion layer 16a and non-contact portions 46 that are not in contact with the anode gas diffusion layer 16a, which are alternately repeated in the first direction. The length of the contact part 44 and the non-contact part 46 in the first direction is shorter than the length of the contact part 40 and the non-contact part 42 in the first direction. For example, the length of the contact portion 44 in the first direction is 0.25 mm, and the length of the non-contact portion 46 is 0.5 mm.

  As shown in FIG. 4B, the MEA 10 and the anode gas diffusion layer 16a are compressed and joined by pressing using the anode side separator 18a and the cathode side separator 18c. The compression conditions are, for example, temperature: normal temperature to 150 ° C., pressure: 0.1 MPa to 3 MPa. At this time, since the width of the unevenness of the anode side separator 18a is small and the length X2 in the first direction of the non-contact portion 46 of the anode side separator 18a is short, the anode gas diffusion layer 16a has the unevenness of the anode side separator 18a. Deformation due to is difficult to occur. Further, by making the compression condition in FIG. 4B substantially the same as the compression condition in FIG. 3C, even if the length X1 in the first direction of the non-contact portion 42 of the cathode side separator 18c is long. Further, occurrence of further bending deformation in the cathode gas diffusion layer 16c is suppressed. For these reasons, the MEA 10 is prevented from being deformed and remains flat. Note that “the compression conditions are substantially the same” means that the temperature and pressure conditions are the same so that no further bending deformation occurs in the cathode gas diffusion layer 16c. The anode separator 18a is joined to the main surface of the anode gas diffusion layer 16a opposite to the MEA 10 side to form the anode gas flow path 20a.

  As described above, according to Example 1, as shown in FIG. 3B, the cathode catalyst layer 14c (first catalyst layer) and the cathode gas diffusion layer 16c (first) are formed on one main surface of the electrolyte membrane 12. A cathode-side separator 18c (first flow path forming member) that forms the cathode gas flow path 20c is disposed with a (1 gas diffusion layer) interposed therebetween. A flat plate member 50 having a flat surface on the electrolyte membrane 12 side is disposed on the other main surface of the electrolyte membrane 12. As shown in FIG. 3C, the electrolyte membrane 12, the cathode catalyst layer 14c, and the cathode gas diffusion layer 16c are compressed and joined by the cathode side separator 18c and the flat plate member 50. As shown in FIG. 4 (a), the anode catalyst layer 14a (second catalyst layer) and the anode gas diffusion layer 16a (second gas diffusion layer) are sandwiched between the other main surface of the electrolyte membrane 12, An anode separator 18a (second flow path forming member) that forms the anode gas flow path 20a is disposed. The length X2 in the first direction of the non-contact portion 46 that does not contact the anode gas diffusion layer 16a of the anode-side separator 18a is the length in the first direction of the non-contact portion 42 that does not contact the cathode gas diffusion layer 16c of the cathode-side separator 18c. It is shorter than X1. As shown in FIG. 4B, the electrolyte membrane 12, the anode catalyst layer 14a, and the anode gas diffusion layer 16a are compressed and joined by the anode side separator 18a and the cathode side separator 18c. Thereby, as above-mentioned, it can suppress that MEA10 deform | transforms. As a result, the concentration of stress on a part of the electrolyte membrane 12 is suppressed, and a decrease in the strength of the electrolyte membrane 12 can be suppressed. Further, since the deformation of the MEA 10 is suppressed, the bonding strength between the MEA 10 and the anode gas diffusion layer 16a and the cathode gas diffusion layer 16c can be made uniform in the plane.

  FIG. 5A to FIG. 5C are cross-sectional views illustrating another method for manufacturing the fuel cell according to the first embodiment. As shown in FIG. 5A, the anode catalyst layer 14a and the cathode catalyst layer 14c are formed on both main surfaces of the electrolyte membrane 12, and the MEA 10 is formed. A cathode gas diffusion layer 16c is disposed on the main surface of the cathode catalyst layer 14c opposite to the electrolyte membrane 12 side. On the main surface opposite to the MEA 10 side of the cathode gas diffusion layer 16c, a simulation member 60 simulating the unevenness of the cathode side separator 18c is disposed. That is, the simulation member 60 has a large unevenness corresponding to the unevenness of the cathode side separator 18c. Further, the simulation member 60 is provided with a projection 66 on the outer peripheral portion of the uneven surface. The simulated member 60 is made of metal, for example, but may be made of other materials.

  On the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side, a flat plate member 50 having a flat surface facing the MEA 10 is disposed via a protective sheet (not shown) such as a Teflon (registered trademark) sheet. . The MEA 10 and the cathode gas diffusion layer 16c are compressed and joined by pressing using the simulation member 60 and the flat plate member 50. At this time, since the width of the unevenness of the simulated member 60 is large, the main surface of the cathode gas diffusion layer 16c on the simulated member 60 side is deformed by the unevenness of the simulated member 60 to become an uneven shape. On the other hand, since the MEA 10 is pressed by the flat plate member 50, the deformation is suppressed and the flat shape remains unchanged. Further, the cathode gas diffusion layer 16 c is formed with a recess 22 c by the projection 66 of the simulation member 60.

  As shown in FIG. 5B, the protective sheet and the flat plate member 50 are removed, and the anode gas diffusion layer 16a is disposed on the main surface of the anode catalyst layer 14a opposite to the electrolyte membrane 12 side. On the main surface opposite to the MEA 10 side of the anode gas diffusion layer 16a, a simulation member 70 simulating the unevenness of the anode side separator 18a is disposed. That is, the simulation member 70 has a small-width unevenness corresponding to the unevenness of the anode separator 18a. Further, the simulation member 70 is provided with a protrusion 76 on the outer peripheral portion of the uneven surface. The simulated member 70 is formed of, for example, metal, but may be formed of other materials.

  The MEA 10 and the anode gas diffusion layer 16a are compressed and joined by pressing using the simulation member 60 and the simulation member 70. At this time, since the width of the unevenness of the simulated member 70 is small, the main surface on the simulated member 70 side of the anode gas diffusion layer 16a is not easily bent due to the unevenness of the simulated member 70. Further, by making the compression conditions in FIG. 5 (b) substantially the same as the compression conditions in FIG. 5 (a), it is possible to suppress further bending deformation in the cathode gas diffusion layer 16c. For these reasons, the deformation of the MEA 10 is suppressed and remains flat. Further, the anode gas diffusion layer 16 a is formed with a recess 22 a by the protrusion 76 of the simulation member 70.

  As shown in FIG. 5C, the anode-side separator 18a and the cathode-side separator 18c are joined or arranged on the main surface of the anode gas diffusion layer 16a and the cathode gas diffusion layer 16c opposite to the MEA 10. At this time, the protrusion 24a provided on the anode separator 18a is aligned with the recess 22a formed in the anode gas diffusion layer 16a, thereby aligning the anode separator 18a. Similarly, the protrusion 24c provided on the cathode side separator 18c is aligned with the recess 22c formed in the cathode gas diffusion layer 16c, thereby aligning the cathode side separator 18c (for example, cathode gas diffusion formed by the simulation member 60). The alignment of the unevenness of the layer 16c and the unevenness of the cathode separator 18c) is performed. Note that the separator is joined by applying substantially the same pressure as the pressure used when joining the gas diffusion layers described in FIGS. 5A and 5B by compression without heating the MEGA 30. . Thereby, it is suppressed that bending deformation arises in a gas diffusion layer by the process of joining a separator to a gas diffusion layer.

  The MEA and the gas diffusion layer may be joined using a separator that is a gas flow path forming member as in the first embodiment, or a simulated member that simulates a separator as in the first modification of the first embodiment. The MEA and the gas diffusion layer may be joined using In addition, a gas flow path forming member other than the separator (for example, a gas flow path forming member made of an expanded metal or a foamed sintered body disposed between the gas diffusion layer and the separator) or this simulated member is used. The MEA and the gas diffusion layer may be joined.

  FIG. 6 is an exploded perspective view of a fuel cell including a gas flow path forming member made of expanded metal. FIG. 7 is an enlarged cross-sectional view of a part of a fuel cell including a gas flow path forming member made of expanded metal. As shown in FIGS. 6 and 7, the fuel cell 200 includes an anode side gas flow path forming member 26 a disposed on the anode side of the MEGA 30 surrounded by a frame-shaped seal member 32, and a cathode side gas flow path formed on the cathode side. A member 26c is disposed. The anode side gas flow path forming member 26a is disposed in contact with the anode gas diffusion layer 16a between the MEGA 30 and the anode side separator 80a. The cathode side gas flow path forming member 26c is disposed between the MEGA 30 and the cathode side separator 80c in contact with the cathode gas diffusion layer 16c. The anode-side gas flow path forming member 26a and the cathode-side gas flow path forming member 26c are expanded metals formed of stainless steel having a plate thickness of about 0.1 mm, and have a staggered rhomboid through-hole and are in contact with the diffusion layer It has higher water repellency. Note that the expanded metal may be formed of a conductive thin metal plate such as titanium or a titanium alloy in addition to stainless steel.

  An intermediate separator 82 is disposed between the anode side separator 80a and the cathode side separator 80c of the adjacent cells. The anode-side separator 80a, the cathode-side separator 80c, and the intermediate separator 82 are thin flat plates made of metal such as stainless steel, titanium, and aluminum, and have through holes. The fuel gas is supplied to the anode gas diffusion layer 16a through the gap provided in the anode side gas flow path forming member 26a. The oxidant gas is supplied to the cathode gas diffusion layer 16c through the gap provided in the cathode side gas flow path forming member 26c.

  The length X1 of the non-contact portion 92 that is not in contact with the cathode gas diffusion layer 16c between the contact portions 90 where the cathode side gas flow passage forming member 26c is in contact with the cathode gas diffusion layer 16c It is longer than the length X2 of the non-contact part 96 not in contact with the anode gas diffusion layer 16a between the contact parts 94 in contact with the gas diffusion layer 16a.

  Instead of the separator in the manufacturing method described with reference to FIGS. 3A to 4B, the MEA and the gas diffusion layer may be joined using a gas flow path forming member made of such an expanded metal. Moreover, although illustration is abbreviate | omitted, you may join MEA and a gas diffusion layer using the gas flow path formation member which consists of a foaming sintered compact.

  In the first embodiment, the case where the unevenness width of the cathode side separator 18c is larger than the unevenness width of the anode side separator 18a has been described as an example, but the present invention is not limited thereto. The width of the unevenness of the anode side separator 18a may be made larger than the width of the unevenness of the cathode side separator 18c. This is because the fuel gas (hydrogen gas) flowing through the anode-side separator 18a has small molecules and can easily enter the diffusion layer located under the ribs of the separator, and the cathode pitch is narrowed to improve gas diffusion. It is because. When the uneven width of the anode side separator 18a is larger than the uneven width of the cathode side separator 18c, the anode gas diffusion layer 16a is bonded first, and then the cathode gas diffusion layer 16c is bonded.

  In Example 1, after the catalyst ink is applied to both main surfaces of the electrolyte membrane 12 to form the anode catalyst layer 14a and the cathode catalyst layer 14c, the cathode gas diffusion layer 16c and the anode gas diffusion layer 16a are bonded. The case of performing is shown as an example, but other steps may be performed. For example, the cathode catalyst layer 14c is formed on one main surface of the electrolyte membrane 12, the cathode gas diffusion layer 16c is joined to the cathode catalyst layer 14c, and then the anode catalyst layer 14a is formed on the other main surface of the electrolyte membrane 12. The anode gas diffusion layer 16a may be joined to the anode catalyst layer 14a.

  Further, in the first embodiment, the case where the catalyst ink is applied to the electrolyte membrane 12 to form the anode catalyst layer 14a and the cathode catalyst layer 14c is shown as an example, but the catalyst is applied to the anode gas diffusion layer 16a and the cathode gas diffusion layer 16c. The anode catalyst layer 14a and the cathode catalyst layer 14c may be formed by applying ink.

  Although the embodiments of the present invention have been described in detail above, the present invention is not limited to such specific embodiments, and various modifications and changes can be made within the scope of the gist of the present invention described in the claims. It can be changed.

DESCRIPTION OF SYMBOLS 10 Membrane electrode assembly 12 Electrolyte membrane 14a Anode catalyst layer 14c Cathode catalyst layer 16a Anode gas diffusion layer 16c Cathode gas diffusion layer 18a Anode side separator 18c Cathode side separator 20a Anode gas channel 20c Cathode gas channel 22a, 22c Depression 24a, 24c Protrusion 26a Anode-side gas flow path forming member 26c Cathode-side gas flow path forming member 30 Membrane electrode gas assembly 32 Seal member 40, 44 Contact portion 42, 46 Non-contact portion 50 Flat plate member 60, 70 Simulating member 66, 76 Protrusion 80a Anode-side separator 80c Cathode-side separator 82 Intermediate separator 90, 94 Contact part 92, 96 Non-contact part 100, 200 Fuel cell

Claims (1)

A first gas flow path is formed on one main surface of the electrolyte membrane, with a first catalyst layer and a first gas diffusion layer interposed therebetween, through which a gas supplied to the first gas diffusion layer flows. A first non-contact portion that is either a first gas flow path forming member or a simulated member that mimics the first gas flow path forming member and that does not contact the first contact portion that contacts the first gas diffusion layer is the first. A first disposing step of disposing a first member repeated in a direction and disposing a flat plate member having a flat surface on the electrolyte membrane side on the other main surface of the electrolyte membrane;
A first joining step of compressing and joining the electrolyte membrane, the first catalyst layer, and the first gas diffusion layer with the first member and the flat plate member;
After the first bonding step, the gas supplied to the second gas diffusion layer flows on the other main surface of the electrolyte membrane with the second catalyst layer and the second gas diffusion layer interposed therebetween. A second gas flow path forming member that forms the second gas flow path or a simulated member that simulates the second gas flow path forming member, and is in contact with a second contact portion that is in contact with the second gas diffusion layer. A second non-contact portion that is not repeated is arranged in the first direction, and a second member in which the length of the second non-contact portion in the first direction is shorter than the length of the first non-contact portion is disposed. Two placement steps;
A method of manufacturing a fuel cell, comprising: a second joining step of compressing and joining the electrolyte membrane, the second catalyst layer, and the second gas diffusion layer with the first member and the second member.

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