JP5870943B2 - Manufacturing method of fuel cell - Google Patents

Description

  The present invention relates to fuel cell technology.

  The fuel cell includes a membrane electrode assembly and a gas diffusion layer. A fuel cell is formed by stacking a plurality of single cells and applying a predetermined load from both sides in the stacking direction. In a fuel cell, a gas seal member (gasket) may be provided on the outer periphery of the electrolyte membrane in order to suppress cross leakage between both electrodes of fuel gas and oxidizing gas. As one of such fuel cells, a fuel cell is known in which a gas diffusion layer disposed on one electrode is formed smaller than a gas diffusion layer and an electrolyte membrane disposed on the other electrode layer ( For example, see Patent Document 1). Moreover, in the technique of patent document 1, suppression of the cross leak of fuel gas and oxidizing gas is aimed at by providing a gasket.

Japanese Patent Laid-Open No. 2007-066766

  When the gasket is provided so as to be in contact with the outer periphery of the smaller gas diffusion layer, the gap between the outer periphery of the smaller gas diffusion layer and the gasket is caused by, for example, the accuracy of formation of the gas diffusion layer or the gasket. There was a case where a gap occurred.

  Thus, when a gap exists between the outer periphery of the gas diffusion layer and the gasket, the membrane electrode assembly is exposed in this gap. In a polymer electrolyte fuel cell, for example, when the fuel cell repeats power generation and stoppage, the membrane electrode assembly causes a state change between a wet state and a dry state. Here, sufficient external force is not applied to the exposed portion (exposed portion) of the membrane electrode assembly even when a predetermined load is applied from both sides of the fuel cell. Therefore, when the membrane electrode assembly becomes wet, the exposed portion swells to cause buckling deformation. Further, when the membrane electrode assembly is in a dry state, the exposed portion contracts. As described above, there is a possibility that the membrane / electrode assembly may be damaged by repeating the shape change of the membrane / electrode assembly.

  Here, by filling the gap with the resin, the swelling of the membrane electrode assembly in a wet state may be suppressed in some cases. However, even when the gap is filled with resin, the membrane electrode assembly may be damaged.

  Damage to the membrane electrode assembly is undesirable because it can cause cross-leakage of fuel gas and oxidant gas. Therefore, there has been a demand for a technique for suppressing damage to the membrane / electrode assembly even when the membrane / electrode assembly changes between a wet state and a dry state. Further, in the fuel cell, it has been desired to suppress the number of parts, simplify the manufacturing process, reduce the manufacturing cost, and the like.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one form of this invention, the manufacturing method of a fuel cell is provided. This manufacturing method is an electrode body comprising (a) a membrane electrode assembly and first and second gas diffusion layers disposed on both sides of the membrane electrode assembly, wherein the first gas diffusion The layer has a smaller area than the second gas diffusion layer, and the outer peripheral portion of the first gas diffusion layer is inside the outer peripheral portion of the membrane electrode assembly and the outer peripheral portion of the second gas diffusion layer. A step of preparing an electrode body, and (b) a thermosetting resin on the first surface on the side where the first gas diffusion layer is disposed in the outer peripheral portion of the membrane electrode assembly. Applying the filling member, and (c) disposing the sealing member with a gap with respect to the first gas diffusion layer, and disposing the sealing member on the applied filling member, A first filling part of the filling member sandwiched between the sealing member and the membrane electrode assembly. (D) forming a portion and an exposed portion that is another part of the filling member and protrudes from the gap to the outside of the first gas diffusion layer in the stacking direction of the membrane electrode assembly; Curing the first filling portion to form an electrode body with a seal; and (e) disposing a first separator on the surface of the seal member and on the surface of the first gas diffusion layer. Curing the exposed portion. According to the manufacturing method of this aspect, when the first separator is disposed on the surface of the seal member and the surface of the first gas diffusion layer, the exposed portion of the filling member is cured. That is, when the first separator is disposed, since the exposed portion can flow between the first separator and the electrode body with the seal, the possibility that excessive pressure is applied to the membrane electrode assembly can be reduced. The possibility that the bonded body is damaged can be reduced. In addition, since a part of the filling member protrudes from the gap, a predetermined load can be applied to a portion of the membrane electrode assembly corresponding to the gap. Thereby, the possibility that the membrane electrode assembly is buckled and deformed can be reduced, and the possibility that the membrane electrode assembly is damaged can be reduced.

(2) In the manufacturing method of the above aspect, in the step (d), the portion where the first filling portion is disposed is sandwiched between a pair of structures in the electrode body with seal in the compression direction. Including a step of heating and curing the first filling portion while applying force, and in a period in which force is applied in the compression direction, of the pair of structures disposed on the first gas diffusion layer side The structure 1 is maintained at a temperature lower than the temperature at which the filling member is cured, and the second structure disposed on the second gas diffusion layer side of the pair of structures is formed by the filling member. It may be maintained above the curing temperature. According to the manufacturing method of this embodiment, the possibility that the exposed portion is cured in the step (d) is reduced by heating and curing the first filling portion from the side opposite to the exposed portion across the membrane electrode assembly. it can.

(3) In the manufacturing method of the above aspect, the filling member may include an electric conductor, and the step (d) may include a step of curing the first filling portion by induction heating. According to the manufacturing method of this aspect, since the first filling portion can be directly heated by induction heating, the time for curing the first filling portion can be shortened.

(4) In the manufacturing method of the above aspect, the seal member includes an electric conductor in a contact portion including a surface in contact with the first filling portion, and the step (d) induction-heats the contact portion. Thus, a step of curing the first filling portion may be included. According to the manufacturing method of this aspect, the first filling portion can be easily heated to the thermosetting temperature or more and cured by induction heating of the contact portion.

(5) In the manufacturing method according to the above aspect, the amount of the filling member applied in the step (b) is 1.2 times or more the volume of the space formed between the seal member and the electrode body. It may be 2.0 times or less. According to the manufacturing method of this aspect, the filling member can surely protrude outside the first gas diffusion layer.

  The present invention can be realized in various forms, for example, in the form of a fuel cell manufacturing method, a fuel cell, a vehicle equipped with a fuel cell, and the like.

It is explanatory drawing which shows schematic structure of the fuel cell system in 1st Embodiment. It is a figure for demonstrating the structure of a single cell. It is a top view which shows typically the arrangement | positioning relationship of a 1st and 2nd gas diffusion layer. 5 is a diagram for explaining a method for manufacturing the fuel cell 200. FIG. It is a figure for demonstrating the manufacturing method of the fuel cell of the 1st reference example. It is a figure for demonstrating the manufacturing method of the fuel cell of the 2nd reference example. It is a figure for demonstrating the manufacturing method of a fuel cell. It is a figure for demonstrating the manufacturing method of a fuel cell.

Next, embodiments of the present invention will be described in the following order.
A. First Embodiment and Reference Example B: Second Embodiment:
C: Third embodiment:
D. Variation:

A. First embodiment and reference examples:
A-1: First embodiment:
A-1-1: Configuration of fuel cell:
FIG. 1 is an explanatory diagram showing a schematic configuration of a fuel cell system 5 according to the first embodiment. The fuel cell system 5 includes a fuel cell 200, a hydrogen tank 50, an air compressor 40, and a control unit 26. The hydrogen tank 50 stores hydrogen as fuel gas. The air compressor 40 supplies compressed air as an oxidizing gas to the fuel cell 200. The control unit 26 controls the entire fuel cell system 5.

  The fuel cell 200 is a polymer electrolyte fuel cell. The structure of the fuel cell 200 is a stack structure in which a plurality of single cells 10 are stacked. The fuel cell 200 includes an end plate 21, an insulating plate 22, and a current collector plate 23 in addition to the plurality of single cells 10. On both sides in the stacking direction (Z-axis direction), current collector plate 23, insulating plate 22 and end plate 21 are arranged in this order from the single cell 10 side toward the outside. The two end plates 21 are fastened with a predetermined fastening force (load) by a tension rod 24 and a nut 25. Thereby, a predetermined force is applied to each single cell 10 from both sides in the stacking direction. At least one of the nuts 25 is provided with a drive unit 27 for adjusting the fastening force by rotating the nut 25.

  Each single cell 10 generates power by an electrochemical reaction between a fuel gas (hydrogen) and an oxidizing gas (oxygen contained in air). Hydrogen as fuel gas stored in the hydrogen tank 50 flows through the hydrogen gas supply path 53 after being decompressed by the decompression valve 51. The flowing hydrogen is adjusted to a predetermined pressure by a pressure adjusting valve 52 provided in the hydrogen gas supply path 53 and supplied to the fuel cell 200. A gas containing hydrogen (anode supply gas) supplied to the fuel cell 200 is supplied to each single cell 10 via an anode gas supply manifold (not shown) formed inside the fuel cell 200, and It is used for power generation in the cell 10. Gas (anode exhaust gas) containing hydrogen that has not been used in each single cell 10 is collected through an anode gas discharge manifold (not shown) formed inside the fuel cell 200. Then, the anode exhaust gas is discharged outside the fuel cell 200 through the anode exhaust gas passage 54. The fuel cell system 5 may have a configuration in which anode exhaust gas is recirculated to the supply side.

  The air pressurized by the air compressor 40 is supplied to the fuel cell 200 via the oxidizing gas supply path 41. Air containing oxygen (cathode supply gas) supplied to the fuel cell 200 is supplied to each single cell 10 via a cathode gas supply manifold (not shown), and is used for power generation in each single cell 10. Air (cathode exhaust gas) that has not been used in each single cell 10 is collected via a cathode gas exhaust manifold (not shown) and exhausted to the outside of the fuel cell 200 via a cathode exhaust gas channel 48.

  The refrigerant circulation pump 46 supplies the refrigerant to the fuel cell 200 via the refrigerant circulation channel 47. The coolant heated by the fuel cell 200 is cooled by the radiator 45 and supplied to the fuel cell 200 again. The cooling medium is supplied to each single cell 10 via a refrigerant supply manifold (not shown), and cools each single cell 10. The cooling medium after passing through each single cell 10 is collected via a refrigerant discharge manifold (not shown) and circulates to the radiator 45 via the refrigerant circulation passage 43. As the cooling medium, water or non-freezing water such as a mixed solution of water and ethylene glycol can be used. In this embodiment, liquid is used as the cooling medium, but air may be used as the cooling medium.

  The control unit 26 is a computer that includes a CPU, a memory, and the like (not shown). The control unit 26 receives signals from temperature sensors, pressure sensors, voltmeters, and the like arranged in each unit of the fuel cell system 5 and controls the entire fuel cell system 5 based on the received signals.

  FIG. 2 is a diagram for explaining the configuration of the single cell 10. FIG. 3 is a plan view schematically showing the positional relationship between the first and second gas diffusion layers. In FIG. 2, the vicinity of the peripheral portion is shown in the cross section of the single cell 10. As shown in FIG. 2, the single cell 10 includes an electrode body 90, and first and second separators 62 and 64 disposed so as to sandwich both surfaces of the electrode body 90. The single cell 10 includes a seal member 69 attached to the electrode body 90 by the filling member 120. The electrode body 90, the filling member 120, and the seal member 69 constitute a sealed electrode body 91.

  The electrode assembly 90 includes a membrane electrode assembly (MEA) 80, a first gas diffusion layer 66, a second gas diffusion layer 68, a first water repellent layer 70, and a second water repellent layer 72. . The membrane electrode assembly 80 includes an electrolyte membrane 84 and a cathode 82 and an anode 86 disposed on both surfaces of the electrolyte membrane 84. The electrolyte membrane 84 is a proton-conducting ion exchange membrane formed of a solid polymer material, for example, a fluororesin containing perfluorocarbon sulfonic acid, and exhibits good electrical conductivity in a wet state. Each of the cathode 82 and the anode 86 includes, for example, platinum or a platinum alloy as a catalyst. More specifically, the cathode 82 and the anode 86 include carbon particles carrying the catalyst and an electrolyte similar to the polymer electrolyte that constitutes the electrolyte membrane 20.

  The first gas diffusion layer 66 and the second gas diffusion layer 68 are arranged so as to sandwich the membrane electrode assembly 80 from both sides. The first and second gas diffusion layers 66 and 68 are formed of a conductive member having gas permeability. Examples of the conductive member include carbon paper, carbon cloth, metal mesh, and foam metal. The first and second gas diffusion layers 66 and 68 are both formed as flat plate members. By providing the first and second gas diffusion layers 66 and 68, the gas supply efficiency to the electrode can be improved, and the current collecting property between the first and second separators 62 and 64 and the electrode can be improved. In addition, the electrolyte membrane 20 can be protected by the first and second gas diffusion layers 66 and 68.

  The first water repellent layer 70 is disposed between the membrane electrode assembly 80 and the first gas diffusion layer 66. The second water repellent layer 72 is disposed between the membrane electrode assembly 80 and the second gas diffusion layer 68. The first and second water-repellent layers 70 and 72 include carbon particles and a water-repellent substance such as a fluororesin. The first and second water repellent layers 70 and 72 constitute the first and second gas diffusion layers 66 and 68 by using water repellent ink which is a mixed liquid containing carbon particles and a water repellent substance. It is formed by applying to the surface of the conductive member to be dried, drying and firing. Since the first and second water-repellent layers 70 and 72 are disposed between the membrane electrode assembly 80 and the first and second gas diffusion layers 66 and 68, the liquid electrode is repelled and the membrane electrode junction is repelled. Push it back to the body 80 side. It is possible to suppress the electrolyte membrane 20 from being deficient in moisture by pushing back the liquid water. Moreover, it can suppress that the pore with which the 1st and 2nd gas diffusion layers 66 and 68 are equipped with liquid water is obstruct | occluded by repelling liquid water.

  As shown in FIG. 3, in the present embodiment, the first gas diffusion layer 66 and the second gas diffusion layer 68 have different sizes (areas). In the present embodiment, the area of the first gas diffusion layer 66 is smaller than that of the second gas diffusion layer 68. In the in-plane direction (plane direction) of the membrane electrode assembly 80, the outer peripheral portion 61 of the first gas diffusion layer 66 is the outer peripheral portion 83 of the membrane electrode assembly 80 and the outer peripheral portion of the second gas diffusion layer 68. It is located inside (center side) from 63.

  As shown in FIG. 2, the 1st and 2nd separators 62 and 64 are arrange | positioned so that the electrode body 91 with a seal | sticker may be pinched | interposed from both sides. The first and second separators 62 and 64 are formed of a gas impermeable conductive member. Examples of the conductive member include a carbon member such as dense carbon that has been made to be gas-impermeable by compressing carbon, and a metal member such as press-formed stainless steel. On the surface of the first and second separators 62 and 64 facing the catalyst electrode layer (cathode 82 or anode 86), irregularities for forming flow channel grooves V1 and V2 through which the reaction gas flows are formed. . The channel groove V <b> 1 forms an oxidizing gas channel through which the oxidizing gas flows with respect to the first gas diffusion layer 66. Further, the flow channel V2 forms a fuel gas flow channel through which the fuel gas flows with respect to the second gas diffusion layer 68.

  The seal member 69 has a sheet shape and is formed of a synthetic resin (for example, polyolefin). Polypropylene or polyethylene can be used as the polyolefin. The thickness of the seal member 69 can be determined as appropriate depending on the shapes of the first and second gas diffusion layers 66 and 68 and the first and second separators 62 and 64. For example, the thickness of the seal member 69 is about 100 to 300 μm. The seal member 69 is attached to the first surface 89 on the side where the first gas diffusion layer 66 is disposed in the outer peripheral portion 83 of the membrane electrode assembly 80. The outer shape of the seal member 69 is rectangular as the outer shape of the membrane electrode assembly 80. A space is formed in the center of the seal member 69 so as not to overlap the first gas diffusion layer 66. Further, the seal member 69 is disposed with a gap from the first gas diffusion layer 66. The seal member 69 seals the oxidizing gas flow path.

  The filling member 120 is provided on the membrane electrode assembly 80 exposed in the gap so as to close the gap between the outer peripheral portion of the first gas diffusion layer 66 and the seal member 69. The filling member 120 is disposed between the seal member 69 and the membrane electrode assembly 80 and is used for attaching the seal member 69 to the membrane electrode assembly 80. The filling member 120 includes a thermosetting resin such as polyisobutylene, epoxy, or urethane.

A-1-2. Manufacturing method of fuel cell:
FIG. 4 is a diagram for explaining a method for manufacturing the fuel cell 200. First, the membrane electrode assembly 80 is prepared (step S10). Next, the first gas diffusion layer 66 to which the first water repellent layer 70 is attached is attached to the membrane electrode assembly 80, and the second gas diffusion layer 68 to which the second water repellent layer 72 is attached. Is attached (step S12). That is, step S12 is a process of preparing the electrode body 90.

  Next, the liquid filling member 120 is applied to the first surface 89 on the side where the first gas diffusion layer 66 is disposed in the outer peripheral portion of the membrane electrode assembly 80 (step S14). The amount of the filling member 120 to be applied is preferably 1.2 to 2.0 times the volume of the space S formed between the seal member 69 and the electrode body 90. Since the amount of the filling member 120 is 1.2 times or more the volume of the space S, the filling member 120 can be reliably protruded from the gap M in step S <b> 16 described later. Moreover, since the amount of the filling member 120 is 2.0 times or less of the volume of the space S, the possibility that the filling member 120 protrudes excessively from the gap M in step S16 described later can be reduced. If the filling member 120 protrudes excessively from the gap M, there may be a problem that the oxidizing gas flow path is blocked.

  Next, the seal member 69 is disposed with a gap M with respect to the first gas diffusion layer 66, and the seal member 69 is disposed on the filling member 120. Accordingly, the first gas diffusion from the first filling portion 121 which is a part of the filling member 120 and sandwiched between the seal member 69 and the membrane electrode assembly 80 and the other part of the filling member 120 which is the gap M. An exposed portion 122 that protrudes outside the layer 66 in the stacking direction of the membrane electrode assembly 80 is formed (step S16). For example, the sealing member 69 is disposed on the filling member 120 so that the sealing member 69 and the applied filling member 120 partially overlap when viewed along the stacking direction of the membrane electrode assembly 80.

  Next, the 1st filling part 121 pinched | interposed by the sealing member 69 and the membrane electrode assembly 80 among the filling members 120 is hardened, and the sealing member 69 is attached to the membrane electrode assembly 80 (step S17). Thereby, the electrode body 91 with a seal is formed. In step S <b> 17, the exposed portion 122 that protrudes outside the first gas diffusion layer 66 of the filling member 120 is not cured. Curing of the first filling portion 121 is performed as follows. That is, the portion of the electrode body with seal 91 where the first filling portion 121 is disposed is sandwiched between the pair of structures 141 and 142 and a force (surface pressure) F is applied in the compression direction, while the first filling portion 121 is Heat to cure. The time during which the surface pressure is applied at each location is preferably within 1 second, and the surface pressure is preferably 0.01 MPa to 1 MPa. Here, of the pair of structures 141 and 142, the structure disposed on the first gas diffusion layer 66 side is referred to as a “first structure 141” and is disposed on the second gas diffusion layer 68 side. The body is referred to as “second structure 142”. In the present embodiment, metal rolls are used for the first and second structures 141 and 142. The first and second structures 141 and 142 are conveyed to press only the portion of the electrode body 91 with the seal where the first filling portion 121 is located. The first and second structures 141 and 142 are not limited to rolls, and may have other structures such as a flat plate. During the pressing period (force is applied in the compression direction), the first structure 141 is maintained at a temperature lower than the temperature at which the filling member 120 is cured, and the second structure 142 Maintained above the curing temperature. For example, when the curing temperature of the filling member 120 is 80 ° C., the second structure 142 is maintained at 80 ° C. or higher. Further, the first and second structures 141 and 142 are preferably maintained at a temperature (for example, 120 ° C.) or less that does not damage the membrane electrode assembly 80. This is because the membrane electrode assembly 80 may be damaged when exposed to high temperatures. Further, the first structure 141 is maintained at about 20 ° C., for example. In this embodiment, in step S <b> 17, the portion surrounded by the dotted line including the first filling portion 121 is cured. Part of the filling member 120 a other than the first filling portion 121 is also cured by heat conduction from the first filling portion 121. Here, in step S17, the exposed portion 122 is not cured.

  Next, the first and second separators 62 and 64 are attached to both sides of the electrode body 91 with a seal (step S18). Specifically, an adhesive is applied to a portion of the first and second separators 62 and 64 that contacts the seal member 69, and the electrode body with seal 91 is stacked in the stacking direction by the first and second separators 62 and 64. Apply force in the direction of compression. Thereby, the 1st and 2nd separators 62 and 64 and the seal member 69 are attached. Also, at least the first separator 62 is heated to a temperature at which the filling member 120 is cured. As a result, the exposed portion 122 is cured and the filling member 120 and the first separator 62 are attached. Thereby, the single cell 10 is manufactured. The fuel cell 200 is manufactured by stacking a plurality of single cells 10. The step of placing the first and second separators 62 and 64 on the seal member 69 (arrangement step) and the step of curing the exposed portion 122 (exposure curing step) are performed before the arrangement step. If the exposure curing process is not performed, the process may be performed in an arbitrary order. That is, the exposure curing process may be performed while performing the arrangement process, or the exposure curing process may be performed after the arrangement process.

A-1-3. First reference example:
FIG. 5 is a diagram for explaining a method of manufacturing the fuel cell 200p of the first reference example. The difference from the manufacturing method of the first embodiment is that when the sealing member 69 is attached to the electrode body 90, all of the filling member 120p is cured, and then the first and second separators (not shown) are sealed. It is a point attached to the attached electrode body 91. That is, in this reference example, all the filling members 120p are cured in step S17 (FIG. 4). Since other configurations are the same as those of the fuel cell 200 of the first embodiment, the same configurations are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 5, consider a case where the gap M between the seal member 69 and the first gas diffusion layer 66 is wide and the filling member 120 p does not protrude outside the first gas diffusion layer 66. In this case, even when the unit cell 10p is assembled as the fuel cell 200p, the load applied from both sides in the stacking direction is not sufficiently applied to the portion (corresponding MEA portion) of the membrane electrode assembly 80 that overlaps the filling member 120p. There is. The electrolyte membrane 20 composed of the polymer electrolyte repeats moisture absorption and drying as the fuel cell 200p repeats power generation and stoppage or the power generation state changes. The electrolyte membrane 20 swells by absorbing moisture and contracts by drying. Here, in the case of the fuel cell 200p, since a sufficient compressive load is not applied to the corresponding MEA portion, the electrolyte membrane 20 may be buckled due to swelling of the electrolyte membrane 20. In particular, when the gap M is wider than the design value, the filling member 120p is thinner than the design value, and there is a high possibility that a sufficient compressive load is not applied to the corresponding MEA portion.

A-1-4. Second reference example:
FIG. 6 is a diagram for explaining a method of manufacturing the fuel cell 200r of the second reference example. The difference from the manufacturing method of the first embodiment is that when the seal member 69 is attached to the electrode body 90, the first and second separators (not shown) are sealed after all of the filling member 120r is cured. It is a point attached to the electrode body 91. That is, in this reference example, all the filling members 120r are cured in step S17. Since other configurations are the same as those of the fuel cell 200 of the first embodiment, the same configurations are denoted by the same reference numerals and description thereof is omitted.

  As shown in FIG. 6, when the filling member 120r protrudes from the gap M to the outside of the first gas diffusion layer 66, the following problem may occur. That is, when the single cell 10r is assembled as the fuel cell 200r, the force from the first separator 62 is concentrated and applied to the filling member 120 (particularly, the portion protruding outward from the first gas diffusion layer 66). Thus, excessive pressure is applied to the corresponding MEA portion. Thereby, the membrane electrode assembly 80 may be damaged. In particular, when the gap M is narrower than the design value, the amount of the filling member 120r that protrudes to the outside increases, and the possibility that the corresponding MEA portion is damaged increases.

  As described in the first and second reference examples, when all of the filling members 120p and 120r are cured when the electrode body 90 is attached to the seal member 69, the film is caused by the variation in the size of the gap M. The electrode assembly 80 may be damaged.

A-1-5. effect:
On the other hand, in the said embodiment, the sealing member 69 is attached to the membrane electrode assembly 80 by hardening the 1st filling part 121 of the filling member 120 (step S16 of FIG. 4). Thereby, the electrode body 91 with a seal | sticker can be easily conveyed to the following process. Further, when the membrane electrode assembly 80 is attached to the seal member 69, the exposed portion 122 is not cured when the first separator 62 is attached to the electrode body 91 with the seal without attaching the exposed portion 122 (FIG. 4 step S17). That is, when the first separator 62 is disposed on the electrode body 91 with a seal, the exposed portion 122 is cured. Thereby, since the exposed part 122 hardens | cures after flowing in the clearance gap between the 1st separator 62 and the electrode body 91 with a seal | sticker, possibility that an excessive pressure will be added to a corresponding MEA part can be reduced. Therefore, the possibility that the membrane electrode assembly 80 is damaged can be reduced. In addition, since the filling member 120 protrudes from the gap M, the filling member 120 does not become so thin that it does not protrude outside the first gas diffusion layer 66. Thereby, the suitable pressure designed also to corresponding | compatible MEA part can be applied. Therefore, the possibility that the membrane electrode assembly 80 is buckled and deformed can be reduced, and the possibility that the membrane electrode assembly 80 is damaged can be reduced.

  Moreover, in the said embodiment, force is applied to the direction which compresses the electrode body 91 with a seal | sticker with respect to the lamination direction by 1st and 2nd structure 141,142 in step S17. At this time, the second structure 142 disposed on the second gas diffusion layer 68 side is maintained at a temperature equal to or higher than the thermosetting temperature, and the first structure 141 disposed on the first gas diffusion layer 66 side is The temperature is kept lower than the thermosetting temperature. Thereby, in step S17, possibility that the exposed part 122 will harden | cure can be reduced.

B. Second embodiment:
FIG. 7 is a diagram for explaining a method of manufacturing the fuel cell 200a. The same steps as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. Moreover, about the same structure as 1st Embodiment and the fuel cell 200, while attaching | subjecting the same code | symbol, description is abbreviate | omitted. After Steps S10 and S12, the liquid filling member 120a is applied to the first surface 89 on the side where the first gas diffusion layer 66 is disposed in the outer peripheral portion of the membrane electrode assembly 80 (Step S14a). . Filling member 120a includes a thermosetting resin and an electrical conductor. As the electrical conductor, for example, a metal such as carbon, steel, tungsten, tin, aluminum, copper, or brass can be used. The electrical conductor is preferably a ferromagnetic material. When the electrical conductor is a ferromagnetic material, the filling member 120a can be heated to a predetermined temperature in a short time due to hysteresis loss during induction heating described later. The electrical conductor is preferably in the form of powder of several tens μm or fine powder so as not to damage the membrane electrode assembly 80.

  After step S14a, the sealing member 69 is disposed with a gap M with respect to the first gas diffusion layer 66, and the sealing member 69 is disposed on the filling member 120a, whereby a part of the filling member 120a is disposed in the gap. M protrudes outside the first gas diffusion layer 66 from M (step S16). Next, the portion 92 (first corresponding portion 92) corresponding to the first filling portion 121a in the electrode body 90 is heated by high frequency induction (step S17a). Specifically, the first corresponding portion 92 is inserted into a coil connected to an AC power source, and an AC current is passed through the coil. Thereby, the 1st filling part 121a is heated and hardened. In the present embodiment, in step S17a, the portion surrounded by a dotted line including the first filling portion 121a is cured. Part of the filling member 120a other than the first filling portion 121a is also cured by heat conduction from the first filling portion 121a. Here, in step S17a, the exposed portion 122a is not cured.

  Next, the first and second separators 62 and 64 are attached to both sides of the electrode body 91 with a seal (step S18). Thereby, the single cell 10a is manufactured. The fuel cell 200a is manufactured by stacking a plurality of single cells 10a.

  In the said 2nd Embodiment, there exists the same effect about the structure and manufacturing process same as 1st Embodiment. For example, the possibility that the membrane electrode assembly 80 is buckled and deformed can be reduced, and the possibility that the membrane electrode assembly 80 is damaged can be reduced. In addition, in the second embodiment, since the first filling portion 121a can be directly heated by induction heating, the time for curing the first filling portion 121a can be shortened. Thereby, the manufacturing time of the fuel cell 200a can be shortened.

C. Third embodiment:
FIG. 8 is a diagram for explaining a method of manufacturing the fuel cell 200b. The differences from the second embodiment are the use of the filling member 120 of the first embodiment and the configuration of the seal member 69b. Since other manufacturing steps and configurations are the same as those of the second embodiment, the same configurations are denoted by the same reference numerals and description thereof is omitted.

  After steps S10 to S14 (see FIG. 4), the sealing member 69b is disposed with a gap M with respect to the first gas diffusion layer 66, and the sealing member 69b is disposed on the filling member 120, thereby filling. A part of the member 120 protrudes outside the first gas diffusion layer 66 from the gap M (step S16b). The seal member 69b is mainly formed of a synthetic resin such as polyolefin. Moreover, the contact part 610 including the surface which contacts the 1st filling part 121 among the sealing members 69b contains an electrical conductor.

  After step S16b, the contact portion 610 of the electrode body 90 is heated by high-frequency induction heating of the contact portion 610, whereby the first filling portion 121a is heated and cured. At this time, the exposed portion 122 is not cured. Next, step S18 (FIG. 7) is performed.

  In the said 3rd Embodiment, there exists the same effect about the structure and manufacturing process same as 1st Embodiment. For example, the possibility that the membrane electrode assembly 80 is buckled and deformed can be reduced, and the possibility that the membrane electrode assembly 80 is damaged can be reduced. In addition, in the third embodiment, the first filling portion 121 can be easily heated to a temperature equal to or higher than the thermosetting temperature and hardened by induction heating the contact portion 610.

D. Variation:
D-1. First modification:
Among the above embodiments, the fuel cell may be manufactured by combining the second embodiment and the third embodiment. In other words, the filling member 120a including the electric conductor may be used, and the sealing member 69b including the electric conductor may be used. By doing so, the first filling portion 121a can be heated to the curing temperature and cured in a shorter time.

  The present invention is not limited to the above-described embodiments, examples, and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments, examples, and modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the above effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

DESCRIPTION OF SYMBOLS 5 ... Fuel cell system 10, 10a, 10p, 10r ... Single cell 20 ... Electrolyte membrane 21 ... End plate 22 ... Insulating plate 23 ... Current collecting plate 24 ... Tension rod 25 ... Nut 26 ... Control part 27 ... Drive part 40 ... Air Compressor 41 ... Oxidizing gas supply passage 43 ... Refrigerant circulation passage 45 ... Radiator 46 ... Refrigerant circulation passage 47 ... Refrigerant circulation passage 48 ... Cathode exhaust passage 50 ... Hydrogen tank 51 ... Pressure reducing valve 52 ... Pressure regulating valve 53 ... Hydrogen gas supply Path 54 ... Anode exhaust gas path 61 ... Outer peripheral part 62 ... First separator 62 ... Second separator 63 ... Outer peripheral part 66 ... First gas diffusion layer 68 ... Second gas diffusion layer 69, 69b ... Seal member 70 ... First water repellent layer 72 ... Second water repellent layer 80 ... Membrane electrode assembly 82 ... Cathode 83 ... Outer peripheral portion 84 ... Electrolyte membrane 86 ... Anode 89 First surface 90: Electrode body 91 with seal 91 ... Electrode body 92 ... First corresponding portion 120, 120a, 120p, 120r ... Filling member 121, 121a ... First filling portion 122, 122a ... Exposed portion 141 ... First structure 142 ... second structure 200, 200a, 200b, 200p, 200r ... fuel cell 610 ... contact portion S ... space M ... gap

Claims (5)

A fuel cell manufacturing method comprising:
(A) An electrode body comprising a membrane electrode assembly and first and second gas diffusion layers disposed on both sides of the membrane electrode assembly, wherein the first gas diffusion layer is An electrode having an area smaller than that of the second gas diffusion layer, wherein an outer peripheral portion of the first gas diffusion layer is positioned inside an outer peripheral portion of the membrane electrode assembly and an outer peripheral portion of the second gas diffusion layer Preparing the body,
(B) Applying a filling member containing a thermosetting resin on the first surface on the side where the first gas diffusion layer is disposed in the outer peripheral portion of the membrane electrode assembly;
(C) The seal member is disposed with a gap with respect to the first gas diffusion layer, and the seal member is disposed on the applied filling member, so that the seal member is a part of the filling member and the seal A first filling portion sandwiched between the member and the membrane electrode assembly, and another portion of the filling member that is more outward from the gap in the stacking direction of the membrane electrode assembly than the first gas diffusion layer. An exposed exposed portion, and a step of forming
(D) curing the first filling portion to form a sealed electrode body;
(E) A step of disposing a first separator on the surface of the seal member and on the surface of the first gas diffusion layer and curing the exposed portion. The manufacturing method according to claim 1,
The step (d)
Including a step of heating and curing the first filling portion while applying a force in a compression direction by sandwiching a portion where the first filling portion is disposed in the electrode body with the seal between a pair of structures. ,
In the period of applying force in the compression direction,
Of the pair of structures, the first structure disposed on the first gas diffusion layer side is maintained at a temperature lower than the temperature at which the filling member is cured,
Of the pair of structures, the second structure disposed on the second gas diffusion layer side is maintained at a temperature higher than the temperature at which the filling member is cured. The manufacturing method according to claim 1,
The filling member includes an electrical conductor;
The step (d)
The manufacturing method including the process of hardening the said 1st filling part by induction heating. It is a manufacturing method of Claim 1 or Claim 3,
The seal member includes an electrical conductor in a contact portion including a surface in contact with the first filling portion,
The step (d)
The manufacturing method including the step of curing the first filling portion by induction heating the contact portion. It is a manufacturing method as described in any one of Claim 1- Claim 4, Comprising:
The manufacturing method wherein the amount of the filling member applied in the step (b) is not less than 1.2 times and not more than 2.0 times the volume of the space formed between the seal member and the electrode body.

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