JP2019212378A - Fuel cell stack and manufacturing method of dummy cell - Google Patents

Abstract

To provide: a fuel cell stack capable of improving its power generation stability without degrading durability of an electrolyte membrane, with the use of a dummy cell which can be laminated on power generation cells while suppressing a rise in local surface pressure; and a method of manufacturing the dummy cell.SOLUTION: A fuel cell stack 10 at least comprises: a laminate 14 in which a plurality of power generation cells 12 each having an electrolyte membrane-electrode assembly are laminated; and a first dummy cell 18 disposed on one end side in a lamination direction in the laminate 14. A dummy structure of the first dummy cell 18 is formed by laminating, in the lamination direction, a first conductive porous body, a second conductive porous body, and a third conductive porous body in this order. A first bonding layer, which is interposed between the first conductive porous body and the second conductive porous body so as to bond them to each other, and a second bonding layer, which is interposed between the second conductive porous body and the third conductive porous body so as to bond them to each other, are located at different positions in the lamination direction.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a laminate in which a plurality of power generation cells having an electrolyte membrane / electrode structure, a resin frame member that circulates around the outer periphery of the electrolyte membrane / electrode structure, and a separator, and at least one of the lamination directions of the laminate The present invention relates to a fuel cell stack provided with a dummy cell disposed at an end of the battery and a method for manufacturing the dummy cell.

  In general, a solid polymer fuel cell employs a solid polymer electrolyte membrane (hereinafter also simply referred to as an electrolyte membrane) made of a polymer ion exchange membrane. The fuel cell includes an electrolyte membrane / electrode structure (MEA) in which an anode electrode is disposed on one surface of an electrolyte membrane and a cathode electrode is disposed on the other surface.

  A power generation cell is configured by sandwiching the electrolyte membrane / electrode structure with a separator, and a stacked body is configured by stacking a plurality of power generation cells. A fuel cell stack is configured by providing a power extraction terminal plate that collects the electric power generated by each power generation cell, an end plate for holding the power generation cells in a stacked state, and the like at both ends in the stacking direction of the stack. The

  By the way, the end side in the stacking direction of the laminated body (hereinafter also simply referred to as the end side) has a lower temperature than the central side of the laminated body in the stacking direction because heat dissipation is promoted through the terminal plate and the like. easy. If the end side of the laminate becomes low temperature due to the influence of the outside air temperature or the like and condensation occurs, there is a concern that the diffusibility of the reaction gas is lowered and the power generation stability of the fuel cell stack is lowered.

  Therefore, for example, in the fuel cell stack disclosed in Patent Document 1, a so-called dummy cell is disposed on at least one end side in the stacking direction of the stack. In the dummy cell, since a metal plate is used instead of the electrolyte membrane, no power is generated and no generated water is generated. For this reason, the dummy cell itself functions as a heat insulating layer between the terminal plate and the laminated body. Therefore, by arranging the dummy cells as described above, it is possible to suppress a temperature decrease on the end side of the stacked body. That is, it is possible to improve the power generation stability by suppressing the fuel cell stack from being affected by the outside air temperature.

Japanese Patent No. 4727972

  The present invention has been made in connection with this type of technology, and without reducing the durability of the electrolyte membrane by a dummy cell that can be stacked on a power generation cell while suppressing a local increase in surface pressure. It is an object of the present invention to provide a fuel cell stack and a dummy cell manufacturing method capable of improving power generation stability.

  In order to achieve the above object, the present invention provides an electrolyte membrane / electrode structure in which electrodes each having a gas diffusion layer made of a conductive porous body are disposed on both sides of an electrolyte membrane, and an electrolyte membrane / electrode structure. A laminated body in which a plurality of power generation cells having a resin frame member that circulates around the outer periphery of the substrate and a separator that sandwiches the electrolyte membrane / electrode structure, and a dummy cell disposed at at least one end in the stacking direction of the laminated body The dummy cell includes a dummy structure corresponding to the electrolyte membrane / electrode structure, a dummy resin frame member that goes around the outer periphery of the dummy structure, and a dummy separator that sandwiches the dummy structure. The dummy structure is formed by laminating a first conductive porous body, a second conductive porous body, and a third conductive porous body having different planar dimensions in this order in the stacking direction. One guide A first bonding layer that is interposed between the conductive porous body and the second conductive porous body, and is bonded between the second conductive porous body and the third conductive porous body. The positions in the stacking direction with the second bonding layer for bonding the layers are different from each other.

  In this fuel cell stack, a dummy cell provided with a dummy structure is disposed at at least one end in the stacking direction of the stack instead of the electrolyte membrane / electrode structure of the power generation cell. In the dummy structure, the first bonding layer for bonding the first conductive porous body and the second conductive porous body, and the second bonding for bonding the second conductive porous body and the third conductive porous body. The positions in the stacking direction with the bonding layer are different from each other. For this reason, for example, compared with the case where the 1st joining layer and the 2nd joining layer are provided in the same position in the lamination direction, it can control that the thickness of a dummy cell increases partially. According to such a dummy cell, even if it is stacked on the power generation cell, it is possible to suppress the occurrence of local surface pressure increase in the power generation cell, so that creep or the like occurs in the electrolyte membrane and the durability of the electrolyte membrane decreases. Can be suppressed.

  Moreover, since the dummy cell is not provided with a solid polymer electrolyte membrane or an electrode catalyst layer, power generation is not performed and water generated by power generation is not generated. As a result, the dummy cell itself functions as a heat insulating layer, and it is possible to suppress dew condensation in the dummy cell. By providing the dummy cell on at least one end side in the stacking direction of the stacked body as described above, the heat insulating property on the end side of the stacked body can be enhanced. For this reason, it can suppress that the temperature of the edge part side of a laminated body becomes low temperature compared with the center side also in a low temperature environment. That is, power generation stability can be improved.

  Furthermore, since the heat insulating property on the end side of the stacked body can be improved, even when the fuel cell stack is started in a sub-freezing environment, the entire stacked body can be effectively heated. As a result, it is possible to suppress the generation of water or the like from freezing on the end side of the laminate and causing a voltage drop.

  As described above, according to this fuel cell stack, the dummy cell that can be stacked on the power generation cell while suppressing the local surface pressure increase can improve the power generation stability without reducing the durability of the electrolyte membrane. Is possible.

  In the fuel cell stack, the first bonding layer is intermittently provided at an edge of the first stacked portion that is a stacked portion of the first conductive porous body and the second conductive porous body, It is preferable that the layer is intermittently provided at the edge of the second stacked portion, which is a stacked portion of the second conductive porous body and the third conductive porous body. In this case, since the dummy structure can be obtained in a simpler process than providing the first bonding layer and the second bonding layer continuously on the outer periphery of the first stacked portion and the second stacked portion, Manufacturing efficiency can be improved.

  In the fuel cell stack, it is preferable that the first bonding layer and the second bonding layer are alternately arranged in the circumferential direction of the first stacked portion and the second stacked portion. In this case, the first conductive porous body, the second conductive porous body, and the third conductive porous body can be joined with sufficient strength by a simple joining process, and the dummy cell It is possible to effectively suppress the occurrence of local surface pressure increase in the stacked power generation cells.

  In the fuel cell stack, the planar dimensions of the first conductive porous body, the second conductive porous body, and the third conductive porous body are rectangular, and the short sides of the rectangular shape are excluded. It is preferable that the first bonding layer and the second bonding layer are provided on the long side. In this case, an increase in internal resistance caused by stacking the dummy cells on the power generation cell can be suppressed, so that the dummy cells can be provided without affecting the power generation performance.

  In the fuel cell stack, the second conductive porous body has a larger planar dimension than the first conductive porous body, and the third conductive porous body has a larger planar dimension than the second conductive porous body. The dummy resin frame member includes an outer peripheral edge, a shelf protruding inward from the inner peripheral end of the outer peripheral edge through the first step surface, and a second from the inner peripheral end of the shelf. A thin-walled portion projecting inward over the entire circumference through the step surface, and the outer peripheral edge of the third conductive porous body overlaps the shelf of the dummy resin frame member, and the second conductive porous It is preferable that the outer peripheral edge portion of the material body faces the thin portion of the dummy resin frame member, and the outer peripheral end surface of the first conductive porous body faces the inner peripheral end surface of the dummy resin frame member.

  In the fuel cell stack described above, the thickness of the second conductive porous body is preferably larger than the height of the second step surface.

  In the fuel cell stack, a space is preferably formed between the thin portion of the dummy resin frame member and the third conductive porous body.

  The present invention also provides an electrolyte membrane / electrode structure in which electrodes each having gas diffusion layers made of a conductive porous material are disposed on both sides of the electrolyte membrane, and a resin that circulates around the outer periphery of the electrolyte membrane / electrode structure. Manufacturing method of dummy cell disposed at at least one end in the stacking direction of a stack of fuel cell stacks including a stack of a plurality of power generation cells having a frame member and a separator sandwiching an electrolyte membrane / electrode structure The first conductive porous body, the second conductive porous body, and the third conductive porous body, each having a different planar dimension, and the first conductive porous body and the second conductive porous body. The first adhesive layer is interposed between the first and second conductive porous bodies, and the second adhesive layer is interposed between the second conductive porous body and the third conductive porous body. The laminating step, the first adhesive layer and the second adhesive layer are cured, and the first conductive layer is cured. Forming a first bonding layer for bonding the conductive porous body and the second conductive porous body, and a second bonding layer for bonding the second conductive porous body and the third conductive porous body, respectively. A curing step for obtaining a dummy structure corresponding to the electrolyte membrane / electrode structure, and a resin for obtaining a dummy structure with a resin frame by providing the dummy structure with a dummy resin frame member that goes around the outer periphery of the dummy structure. A first bonding agent layer having a frame joining step and a second laminating step of obtaining a dummy cell by sandwiching a dummy structure with a resin frame between dummy separators so that the positions in the laminating direction are different from each other in the first laminating step. And providing the 2nd adhesive bond layer WHEREIN: The 1st joining layer and the 2nd joining layer from which the position of a lamination direction mutually differs are formed by a hardening process, It is characterized by the above-mentioned.

  According to this dummy cell manufacturing method, it is possible to obtain a dummy cell including a dummy structure provided with a first bonding layer and a second bonding layer having different positions in the stacking direction. In such a dummy cell, it is possible to suppress a partial increase in thickness as compared with the case where the first bonding layer and the second bonding layer are provided at the same position. It is possible to suppress the occurrence of local surface pressure increase in the power generation cell. As a result, it is possible to suppress the occurrence of creep or the like in the electrolyte membrane of the power generation cell and the decrease in durability.

  In addition, the dummy cell does not generate power and does not generate water, and thus functions as a heat insulating layer. In a fuel cell stack in which such a dummy cell is provided at at least one end in the stacking direction of the stack, the heat insulation on the end of the stack can be improved, so that power generation stability can be improved. it can.

  From the above, according to this dummy cell manufacturing method, it is possible to obtain a dummy cell that can be stacked on a power generation cell while suppressing a local increase in surface pressure, and durability of the electrolyte membrane of a fuel cell stack including this dummy cell. Therefore, it is possible to improve the power generation stability without reducing the performance.

  In the above dummy cell manufacturing method, in the curing step, the fuel cell stack generates power in the first conductive porous body, the second conductive porous body, and the third conductive porous body stacked in the first stacking step. It is preferable to cure the first adhesive layer and the second adhesive layer in a state where a surface pressure equal to the surface pressure applied during operation is applied. In the dummy cell in which the first bonding layer and the second bonding layer are formed in the state where the surface pressure is applied in this manner, when the fuel cell stack is incorporated, the generation of a local surface pressure on the power generation cell is further increased. It can be effectively suppressed.

  In the above dummy cell manufacturing method, in the first stacking step, the first adhesive layer is intermittently formed on the edge of the first stacked portion that is the stacked portion of the first conductive porous body and the second conductive porous body. It is preferable that the second adhesive layer is provided intermittently at the edge of the second laminated portion, which is a laminated portion of the second conductive porous body and the third conductive porous body. In this case, for example, a dummy cell can be obtained more efficiently with a simpler process than when the first bonding layer and the second bonding layer are provided continuously at the edges of the first stacked portion and the second stacked portion.

  In the dummy cell manufacturing method, in the first stacking step, it is preferable that the first adhesive layer and the second adhesive layer are alternately arranged in the circumferential direction of the first stack portion and the second stack portion. In this case, the first conductive porous body, the second conductive porous body, and the third conductive porous body can be joined with sufficient strength by a simple joining process, and the power generation cell. It is possible to obtain a dummy cell that can effectively suppress the occurrence of a local increase in surface pressure when stacked.

  In the above dummy cell manufacturing method, in the first stacking step, the short sides of the first conductive porous body, the second conductive porous body, and the third conductive porous body, each of which has a rectangular planar dimension, are formed. It is preferable to provide a 1st adhesive bond layer and a 2nd adhesive bond layer in the long side except. In this case, it is possible to suppress an increase in internal resistance caused by stacking dummy cells on the power generation cell, and to obtain a dummy cell that can be incorporated into the fuel cell stack without affecting the power generation performance.

  According to the present invention, the power generation stability of the fuel cell stack can be improved without reducing the durability of the electrolyte membrane by the dummy cell that can be stacked on the power generation cell while suppressing a local increase in surface pressure. it can.

1 is an exploded perspective view of a fuel cell stack according to an embodiment of the present invention. FIG. 2 is a cross-sectional view taken along the line II-II of the fuel cell stack of FIG. 1. It is a disassembled perspective view of a power generation cell. It is a front view of the oxidizing gas channel side of the first separator. It is a front view of the oxidizing gas channel side of the second separator. It is a front view by the side of the cooling medium channel of the 3rd separator. It is a front view by the side of the anode electrode of MEA with a resin frame. FIG. 8 is a cross-sectional view taken along line VIII-VIII in FIG. 7. It is a front view by the side of the 3rd conductive porous body of a dummy structure with a resin frame. FIG. 10 is a cross-sectional view taken along line XX in FIG. 9. It is a disassembled perspective view of a dummy structure. It is a top view by the side of the 1st electroconductive porous body of a dummy structure. It is XIII-XIII arrow sectional drawing of FIG. It is a front view by the side of the 2nd space of a dummy 1st separator and a dummy 2nd separator.

  Preferred embodiments of a fuel cell stack and a dummy cell manufacturing method according to the present invention will be described in detail with reference to the accompanying drawings. In the following drawings, components having the same or similar functions and effects are denoted by the same reference numerals, and repeated description may be omitted.

  As shown in FIGS. 1 and 2, the fuel cell stack 10 according to the present embodiment includes a plurality of power generation cells 12 stacked in the horizontal direction (arrow A1, A2 direction) or the gravity direction (arrow C1, C2 direction). A laminate 14 is provided. The fuel cell stack 10 is mounted on a fuel cell vehicle such as a fuel cell electric vehicle (not shown).

  As shown in FIG. 2, the first end power generation unit 16, the first dummy cells 18, and the second dummy cells 20 are disposed outwardly at one end side (arrow A <b> 1 side) in the stacking direction of the stacked body 14. Further, the second end power generation unit 22 and the third dummy cell 24 are disposed outwardly on the other end side (arrow A2 side) in the stacking direction of the stacked body 14. A terminal plate 26a, an insulator 28a, and an end plate 30a are stacked in this order on the outer side (arrow A1 side) of the stacked body 14 than the second dummy cell 20. A terminal plate 26b, an insulator 28b, and an end plate 30b are stacked in this order on the outer side (arrow A2 side) of the stacked body 14 than the third dummy cell 24.

  As shown in FIG. 1, a connecting bar (not shown) is disposed between the sides of the rectangular end plates 30a and 30b. Each connecting bar is fixed at both ends to the inner surfaces of the end plates 30a and 30b via bolts (not shown), etc., and applies a tightening load in the stacking direction (arrows A1 and A2 directions) to the stacked power generation cells 12 To do. Note that the fuel cell stack 10 may include a housing having end plates 30a and 30b as end plates, and the stacked body 14 and the like may be accommodated in the housing.

  As shown in FIG. 3, the power generation cell 12 is configured by laminating a first separator 32, an MEA 34 with a resin frame, a second separator 36, an MEA 34 with a resin frame, and a third separator 38 in this order. . Each of the first separator 32, the second separator 36, and the third separator 38 (each separator) is made of, for example, a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, etc. Etc. to form an uneven cross-sectional shape.

  As shown in FIG.1 and FIG.3, the edge part of each separator at the one end side (arrow B1 side) in the long side direction is individually communicated in the directions of arrows A1 and A2 (stacking direction), respectively. An inlet communication hole 40 and a fuel gas outlet communication hole 42 are provided. The oxidant gas inlet communication hole 40 supplies an oxidant gas, for example, an oxygen-containing gas. The fuel gas outlet communication hole 42 discharges a fuel gas, for example, a hydrogen-containing gas. These oxidant gas and fuel gas are also collectively referred to as reaction gas.

  The separator on the other end side (arrow B2 side) of each separator in the long side direction is individually communicated in the directions of arrows A1 and A2, respectively, and a fuel gas inlet communication hole 44 for supplying fuel gas and an oxidant gas are supplied. An oxidant gas outlet communication hole 46 for discharging is provided. The oxidant gas inlet communication hole 40, the fuel gas outlet communication hole 42, the fuel gas inlet communication hole 44, and the oxidant gas outlet communication hole 46 are also collectively referred to as a reaction gas communication hole.

  A pair of cooling medium inlet communication holes 48 for individually supplying in the directions of arrows A1 and A2 and supplying the cooling medium to the arrow B1 side at both ends of each separator in the short side direction (arrow C1 and C2 directions). Are provided respectively. A pair of cooling medium outlet communication holes 50 for individually discharging in the directions of arrows A1 and A2 and discharging the cooling medium are provided on the arrow B2 side at both end edges in the short side direction of each separator.

  As shown in FIG. 3, a cooling medium flow path 52 that connects the cooling medium inlet communication hole 48 and the cooling medium outlet communication hole 50 is formed on the surface 32 a on the arrow A <b> 1 side of the first separator 32. A plurality of inlet connection grooves 54 a are formed between the cooling medium inlet communication hole 48 and the cooling medium flow path 52. A plurality of outlet connection grooves 54 b are formed between the cooling medium flow path 52 and the cooling medium outlet communication hole 50. The surface 32a of the first separator 32 integrally surrounds the cooling medium inlet communication hole 48, the cooling medium outlet communication hole 50, the cooling medium flow path 52, the inlet connection groove 54a, and the outlet connection groove 54b. A seal member 55 that seals the outside in the surface direction is provided.

  As shown in FIG. 4, an oxidant gas flow path 56 communicating with the oxidant gas inlet communication hole 40 and the oxidant gas outlet communication hole 46 is formed on the surface 32 b on the arrow A <b> 2 side of the first separator 32. . The oxidant gas flow channel 56 includes a plurality of wavy flow channel grooves (or linear flow channel grooves) arranged in parallel with each other.

  The inlet side end of the oxidant gas flow channel 56 is connected to the oxidant gas inlet buffer 58 located outside the power generation region, while the outlet side end of the oxidant gas flow channel 56 is connected to the outside of the power generation region. The oxidant gas outlet buffer unit 60 is located in a row.

  A plurality of inlet connection grooves 62 a are formed between the oxidant gas inlet buffer portion 58 and the oxidant gas inlet communication hole 40. A plurality of outlet connection grooves 62 b are formed between the oxidant gas outlet buffer 60 and the oxidant gas outlet communication hole 46. The surface 32b of the first separator 32 has an oxidant gas inlet communication hole 40, an oxidant gas outlet communication hole 46, an oxidant gas flow path 56, an oxidant gas inlet buffer part 58, an oxidant gas outlet buffer part 60, an inlet. A seal member 63 is provided that integrally surrounds the connecting groove 62a and the outlet connecting groove 62b and seals the inside thereof with the outside in the surface direction. In the first separator 32, the back surface shape of the oxidant gas flow path 56 constitutes a part of the cooling medium flow path 52 (see FIGS. 2 and 3).

  As shown in FIG. 3, a fuel gas passage 66 communicating with the fuel gas inlet communication hole 44 and the fuel gas outlet communication hole 42 is formed on the surface 36 a on the arrow A <b> 1 side of the second separator 36. The fuel gas flow channel 66 is composed of a plurality of wavy flow channel grooves (or linear flow channel grooves) arranged in parallel with each other.

  A fuel gas inlet buffer unit 68 is connected to the inlet side end of the fuel gas flow channel 66 outside the power generation region, while an outlet side end of the fuel gas flow channel 66 is positioned outside the power generation region. Thus, the fuel gas outlet buffer unit 70 is connected. A plurality of fuel gas supply holes 72 a penetrating the second separator 36 in the thickness direction are provided between the fuel gas inlet buffer 68 and the fuel gas inlet communication hole 44. Between the fuel gas outlet buffer part 70 and the fuel gas outlet communication hole 42, a plurality of fuel gas discharge hole parts 72b penetrating the second separator 36 in the thickness direction are provided.

  The surface 36a of the second separator 36 integrally surrounds the fuel gas passage 66, the fuel gas inlet buffer 68, the fuel gas outlet buffer 70, the fuel gas supply hole 72a, and the fuel gas discharge hole 72b. A seal member 73 that seals the inside from the outside in the surface direction is provided.

  As shown in FIG. 5, the surface 36b on the arrow A2 side of the second separator 36 is provided with a fuel gas supply hole 72a and a fuel gas discharge hole 72b surrounded by a seal member 71, The first separator 32 can be configured in the same manner as the surface 32b (see FIG. 4) on the arrow A2 side. That is, an oxidant gas flow path 56 that communicates with the oxidant gas inlet communication hole 40 and the oxidant gas outlet communication hole 46 is provided on the surface 36 b of the second separator 36. Further, an oxidant gas inlet buffer portion 58, an oxidant gas outlet buffer portion 60, an inlet connection groove 62a, an outlet connection groove 62b, and a seal member 63 are formed on the surface 36b of the second separator 36. .

  On the surface 36b side of the second separator 36, each of the fuel gas supply hole portion 72a and the fuel gas discharge hole portion 72b, and the oxidant gas inlet buffer portion 58 and the oxidant gas outlet buffer portion 60 are sealed by seal members 63 and 71, respectively. Blocked.

  As shown in FIG. 3, the surface 38 a on the arrow A <b> 1 side of the third separator 38 can be configured similarly to the surface 36 a on the arrow A <b> 1 side of the second separator 36. That is, the fuel gas flow channel 66 that communicates with the fuel gas inlet communication hole 44 and the fuel gas outlet communication hole 42 is provided on the surface 38 a of the third separator 38. A fuel gas inlet buffer portion 68, a fuel gas outlet buffer portion 70, a fuel gas supply hole portion 72a, a fuel gas discharge hole portion 72b, and a seal member 73 are formed on the surface 38a of the third separator 38. Is done.

  As shown in FIG. 6, the surface 38b on the arrow A2 side of the third separator 38 is provided with a fuel gas supply hole 72a and a fuel gas discharge hole 72b surrounded by a seal member 71, The first separator 32 can be configured similarly to the surface 32a (see FIG. 3) on the arrow A1 side. That is, the cooling medium flow path 52, the inlet connection groove 54a, the outlet connection groove 54b, and the seal member 55 are provided on the surface 38b of the third separator 38. On the surface 38b side of the third separator 38, each of the fuel gas supply hole 72a and the fuel gas discharge hole 72b, the cooling medium flow path 52, the inlet connection groove 54a, the outlet connection groove 54b, and the like are sealed members 55, 71. Is blocked by.

  As shown in FIG. 2, the cooling medium flow path 52 on the surface 38b on the arrow A2 side of the third separator 38 adjacent to each other and the cooling medium flow path 52 on the surface 32a on the arrow A1 side of the first separator 32 face each other. Thus, the cooling medium can circulate inside.

  As shown in FIGS. 3, 5, and 6, in the second separator 36 and the third separator 38, the seal members 71 and 73 are provided as described above. Therefore, the fuel gas inlet communication hole 44 is defined by the arrow from the arrow A1 side. The fuel gas flowing to the A2 side flows through the fuel gas supply hole 72a from the arrow A2 side to the arrow A1 side and flows into the fuel gas inlet buffer portion 68 and the fuel gas flow channel 66. The fuel gas flowing through the fuel gas flow channel 66 and flowing into the fuel gas outlet buffer 70 flows through the fuel gas discharge hole 72b from the arrow A1 side to the arrow A2 side, and then the fuel gas outlet communication hole 42. From the arrow A2 side to the arrow A1 side.

  Seal members made of an elastic body (not shown) that circulates around the outer peripheral edge of each separator are integrally formed on both surfaces of each separator.

  As shown in FIGS. 3, 7, and 8, the MEA 34 with a resin frame is configured by bonding a resin frame member 82 to the outer periphery of an electrolyte membrane / electrode structure (MEA) 80. As shown in FIG. 8, the electrolyte membrane / electrode structure 80 includes, for example, a solid polymer electrolyte membrane (hereinafter also simply referred to as an electrolyte membrane) 84 that is a thin film of perfluorosulfonic acid containing moisture. The electrolyte membrane 84 may use an HC (hydrocarbon) electrolyte in addition to the fluorine electrolyte. The electrolyte membrane 84 is sandwiched between the cathode electrode 86 and the anode electrode 88.

  The electrolyte membrane / electrode structure 80 constitutes a stepped MEA in which the planar dimensions of the cathode electrode 86 are smaller than the planar dimensions of the anode electrode 88 and the electrolyte membrane 84. The cathode electrode 86, the anode electrode 88, and the electrolyte membrane 84 may be set to have the same planar dimensions. Further, the anode electrode 88 may have a smaller planar dimension than the cathode electrode 86 and the electrolyte membrane 84.

  The cathode electrode 86 includes a first electrode catalyst layer 90 joined to a surface 84a on one end side (arrow A1 side) of the electrolyte membrane 84, and a first gas diffusion layer 92 laminated on the first electrode catalyst layer 90. Have. The first electrode catalyst layer 90 has a larger planar dimension than the first gas diffusion layer 92, and has an outer peripheral exposed portion 90 a that protrudes outward from the outer peripheral end surface 92 a of the first gas diffusion layer 92. The first electrode catalyst layer 90 has a smaller planar dimension than the electrolyte membrane 84.

  The anode electrode 88 includes a second electrode catalyst layer 94 joined to the surface 84b on the other end side (arrow A2 side) of the electrolyte membrane 84, and a second gas diffusion layer 96 laminated on the second electrode catalyst layer 94. Have The second electrode catalyst layer 94 and the second gas diffusion layer 96 have the same planar dimensions and are set to the same planar dimensions as (or less than) the electrolyte membrane 84.

  For example, the first electrode catalyst layer 90 is formed by uniformly applying porous carbon particles having a platinum alloy supported on the surface thereof to the surface of the first gas diffusion layer 92 together with an ion conductive polymer binder. The second electrode catalyst layer 94 is formed, for example, by uniformly applying porous carbon particles carrying a platinum alloy on the surface thereof to the surface of the second gas diffusion layer 96 together with an ion conductive polymer binder.

  The first gas diffusion layer 92 and the second gas diffusion layer 96 are formed of a conductive porous body such as carbon paper or carbon cloth. The planar dimension of the second gas diffusion layer 96 is set larger than the planar dimension of the first gas diffusion layer 92.

  The resin frame member 82 includes, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), It is composed of a resin material such as silicone resin, fluororesin, m-PPE (modified polyphenylene ether resin), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), or modified polyolefin. For example, the resin material may be formed of a film or the like.

  As shown in FIG. 3, the resin frame member 82 has a frame shape and is disposed inside a communication hole group including communication holes 40, 42, 44, 46, 48, 50 including the oxidant gas inlet communication hole 40, Each communication hole 40, 42, 44, 46, 48, 50 is not formed. Further, as shown in FIG. 8, the resin frame member 82 has an outer peripheral edge portion 82b extending from the outer peripheral edge 82a (see FIG. 7) to the inner side of the outer peripheral edge 82a (see FIG. 7). Is provided with an inner bulging portion 82c.

  The inner bulging portion 82c includes a shelf portion 82e extending inward from the inner peripheral end of the outer peripheral edge portion 82b via the first stepped surface 82d, and an inner portion extending inward from the inner peripheral end of the shelf portion 82e. A thin portion 82g extending through two step surfaces 82f is provided. The shelf part 82e is thinner than the outer peripheral edge part 82b, and the thin part 82g is thinner than the shelf part 82e. The first step surface 82d, the shelf 82e, the second step surface 82f, and the thin portion 82g are provided over the entire circumference of the resin frame member 82. The outer peripheral edge of the surface 84b of the electrolyte membrane 84 abuts on the surface 82ea on the arrow A2 side of the shelf 82e. At the inner end of the thin-walled portion 82g, a bank portion 82h facing the outer peripheral exposed portion 90a of the first electrode catalyst layer 90 is provided over the entire circumference. Further, a groove portion 82ha is provided between the bank portion 82h and the second step surface 82f of the thin wall portion 82g.

  A portion of the surface 84a of the electrolyte membrane 84 facing the groove 82ha and the outer peripheral exposed portion 90a of the first electrode catalyst layer 90 are filled with an adhesive 98a so as to go around the outer peripheral exposed portion 90a, and an adhesive portion 98 is provided. . The bonding portion 98 is also filled between the inner peripheral end surface 82 i of the resin frame member 82 and the outer peripheral end surface 92 a of the first gas diffusion layer 92. As the adhesive 98a, for example, a fluororesin system, a silicone resin system, and an epoxy resin system can be suitably used, but the adhesive 98a is not particularly limited thereto. The adhesive 98a is not limited to liquid, solid, thermoplasticity, thermosetting, or the like.

  The resin frame member 82 and the outer peripheral edge portion of the second gas diffusion layer 96 are integrated by the first joint portion 100 using an adhesive resin. As shown in FIG. 7, the first joint portion 100 is provided so as to go around the outer peripheral edge portion of the second gas diffusion layer 96. As shown in FIG. 8, the first joint portion 100 is, for example, a resin that is integrally molded with respect to the resin frame member 82 so as to go around the inner end portion of the outer peripheral edge portion 82b and protrude toward the arrow A2 side. The protrusion 100a can be configured by being thermally deformed. The first joint portion 100 is formed of a first resin impregnated portion 100b and a first melt-solidified portion 100c.

  The first resin impregnated portion 100 b is formed by impregnating the outer peripheral edge of the second gas diffusion layer 96 with the molten resin protrusion 100 a. The first molten and solidified portion 100c is melted between the first step surface 82d of the resin frame member 82 that is disposed apart from the outer peripheral end surface 101 of the electrolyte membrane 84 and the anode electrode 88. It is formed by injecting and solidifying. In FIG. 8, the surface of the shelf 82e integrated with the first melt-solidified portion 100c and the first step surface 82d are indicated by a two-dot chain line.

  An adhesive portion 98 is provided so as to go around the outer peripheral exposed portion 90 a of the first electrode catalyst layer 90 and the outer peripheral end surface 92 a of the first gas diffusion layer 92, or so as to go around the outer peripheral edge of the second gas diffusion layer 96. By providing the first joint portion 100, cross leakage between the cathode electrode 86 and the anode electrode 88 is prevented.

  As shown in FIG. 3, an oxidant gas inlet buffer part 102a and an oxidant gas outlet buffer part 102b are provided on the surface 82j of the resin frame member 82 on the cathode electrode 86 side (arrow A1 side). As shown in FIG. 7, a fuel gas inlet buffer portion 105a and a fuel gas outlet buffer portion 105b are provided on the surface 82k of the resin frame member 82 on the anode electrode 88 side (arrow A2 side).

  As shown in FIG. 2, the first end power generation unit 16 includes a first separator 32, a dummy structure 106 with a resin frame, a dummy first separator 108, and a resin from the arrow A1 side toward the arrow A2 side. The framed MEA 34 and the third separator 38 are stacked in this order.

  As shown in FIGS. 9 and 10, the dummy structure with resin frame 106 is configured by bonding a dummy resin frame member 111 to the outer periphery of the dummy structure 110. As shown in FIGS. 10, 11, and 12, the dummy structure 110 includes three first conductive porous bodies 112 and second conductive porous bodies each having different plane dimensions (surface area / outer dimensions). 114 and the third conductive porous body 116 are laminated in this order from the arrow A1 side to the arrow A2 side. The relationship between the sizes of the planar dimensions is that the first conductive porous body 112 <the second conductive porous body 114 <the third conductive porous body 116.

  For this reason, as shown in FIGS. 10 and 12, the outer peripheral edge portion of the third conductive porous body 116 is more outward than the outer peripheral end face 114a of the second conductive porous body 114 over the entire periphery. A projecting outer peripheral exposed portion 116a is provided. An outer peripheral exposed portion 114b that protrudes outward from the outer peripheral end surface 112a of the first conductive porous body 112 is provided over the entire outer peripheral edge of the second conductive porous body 114.

  The first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 are made of the same material, and the conductive material constituting the first gas diffusion layer 92 or the second gas diffusion layer 96 is used. The same material as the porous porous body can be used.

  In the present embodiment, the thicknesses of the first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 are set to the conductive thicknesses of the second gas diffusion layer 96. The same thickness as the porous porous body was set. Thus, the dummy structure 110 can be obtained more easily by adjusting the planar dimensions of the conductive porous body as described above.

  As shown in FIGS. 12 and 13, the stacked first conductive porous body 112 and second conductive porous body 114 are bonded together by a first bonding layer 118 a interposed therebetween. The 2nd conductive porous body 114 and the 3rd conductive porous body 116 are joined by the 2nd joining layer 118b interposed between each other. As will be described later, the first bonding layer 118a and the second bonding layer 118b are formed by curing the first adhesive layer 119a and the second adhesive layer 119b, respectively. As a material for the first adhesive layer 119a and the second adhesive layer 119b, an adhesive 98a can be used.

  As shown in FIG. 12, the first bonding layer 118a is intermittently (spotted) on the long side of the first laminated portion 112b, which is a laminated portion of the first conductive porous body 112 and the second conductive porous body 114. Provided). The second bonding layer 118b is provided intermittently (in a spot shape) on the long side of the second stacked portion 114c, which is a stacked portion of the second conductive porous body 114 and the third conductive porous body 116. . In addition, the first bonding layers 118a and the second bonding layers 118b are alternately arranged in the extending direction of the long sides of the first stacked portion 112b and the second stacked portion 114c (the directions of arrows B1 and B2).

  As shown in FIG. 13, each of the first bonding layers 118a and each of the second bonding layers 118b are disposed so that the positions in the stacking direction (arrows A1 and A2 directions) are different from each other.

  As shown in FIGS. 9 and 10, the dummy resin frame member 111 has the same configuration as the resin frame member 82 that constitutes the MEA 34 with a resin frame in FIGS. 7 and 8, and includes an outer peripheral edge portion 82 b and an inner bulge. Part 82c. As shown in FIG. 10, the arrow A1 side of the outer peripheral exposed portion 116a of the third conductive porous body 116 abuts on the shelf 82e of the inner bulging portion 82c. Part of the outer peripheral exposed part 116a of the third conductive porous body 116 on the arrow A1 side and part of the outer peripheral exposed part 114b of the second conductive porous body 114 on the arrow A1 side face the thin-walled part 82g. . The arrow A1 side of the outer peripheral exposed portion 114b of the second conductive porous body 114 is in contact with the protruding end surface of the bank portion 82h.

  In the directions of arrows A1 and A2, the outer peripheral end surface 114a of the second conductive porous body 114 is disposed between the third conductive porous body 116 and the thin portion 82g. The inner peripheral end surface 82i of the dummy resin frame member 111 is formed in the direction perpendicular to the stacking direction (arrows A1 and A2 directions) and the outer peripheral end surface 114a of the second conductive porous body 114 and the first conductive porous body 112. It is located between the outer peripheral end face 112a. The outer peripheral end surface 112a of the first conductive porous body 112 faces the inner peripheral end surface 82i of the dummy resin frame member 111 with an interval. The height of the second step surface 82f is smaller than the thickness of the second conductive porous body 114.

  The outer peripheral exposed portion 116a of the third conductive porous body 116 and the surface 82ea on the arrow A2 side of the shelf 82e of the dummy resin frame member 111 are joined via the second joint portion 120, thereby providing a resin frame. A dummy structure 106 is formed. As shown in FIG. 9, the second joint 120 is intermittently provided in the circumferential direction with respect to the outer peripheral edge of the third conductive porous body 116. The second joint 120 may be formed so as to go around the dummy structure 110.

  As shown in FIG. 10, the 2nd junction part 120 can be comprised by carrying out the partial heat deformation of the resin projection part 120a integrally molded by the dummy resin frame member 111, for example. In this case, the 2nd junction part 120 is formed from the 2nd resin impregnation part 120b and the 2nd melt-solidification part 120c. In addition, you may remove the part which does not comprise the 2nd junction part 120 in the resin projection part 120a, in other words, the part which remained without being heat-deformed by machining.

  The second resin impregnated portion 120b is formed by impregnating the outer peripheral edge of the third conductive porous body 116 with the molten resin protrusion 120a. The second molten and solidified portion 120c is a resin protrusion that is melted between the first step surface 82d of the dummy resin frame member 111 that is spaced apart from the outer peripheral end surface 116b of the third conductive porous body 116. It is formed by allowing the portion 120a to flow and solidify. In FIG. 10, the surface of the shelf 82e integrated with the second melt-solidified portion 120c and the first step surface 82d are indicated by a two-dot chain line.

  Note that the first bonding part 100 and the second bonding part 120 may use an adhesive 98 a in the same manner as the bonding part 98.

  As shown in FIGS. 2, 3 and 14, the dummy first separator 108 is provided with an inlet blocking part 122a instead of the fuel gas supply hole 72a, and an outlet blocking part 122b instead of the fuel gas discharge hole 72b. Is configured in the same manner as the second separator 36 except that is provided. That is, the surface 108b on the other end side (arrow A2 side) of the dummy first separator 108 is configured similarly to the surface 32b on the other end side (arrow A2 side) of the first separator 32 shown in FIG.

  As shown in FIGS. 2 and 4, an oxidant is provided between the other end side (arrow A2 side) 108b of the dummy first separator 108 and the cathode electrode 86 side (arrow A1 side) of the MEA 34 with resin frame. A first space 124 corresponding to the gas flow path 56 is provided. The first space 124 communicates with the oxidant gas inlet communication hole 40 and the oxidant gas outlet communication hole 46 through a communication path 125 formed in the inlet connection groove 62a and the outlet connection groove 62b. For this reason, the oxidant gas can be circulated similarly to the oxidant gas flow path 56.

  As shown in FIGS. 2 and 14, the surface 108 a on one end side (arrow A <b> 1 side) of the dummy first separator 108, the third conductive porous body 116 side (arrow A <b> 2 side) of the dummy structure 106 with a resin frame, A second space 126 corresponding to the fuel gas flow channel 66 is provided between them. The second space 126 is blocked from the fuel gas inlet communication hole 44 by the inlet blocking part 122a, and is blocked from the fuel gas outlet communication hole 42 by the outlet blocking part 122b. That is, the flow of fuel gas to the second space 126 is restricted by the inlet blocking portion 122a and the outlet blocking portion 122b (hereinafter also collectively referred to as a blocking portion). A heat insulating space is formed.

  In addition, by providing only one of the inlet blocking part 122a and the outlet blocking part 122b, the flow of the fuel gas to the second space 126 may be restricted and the heat insulating space may be formed. Further, in the present embodiment, the blocking portion is configured by not penetrating and forming the fuel gas supply hole 72a and the fuel gas discharge hole 72b (see FIG. 3) in the dummy first separator 108. However, the present invention is not particularly limited to this, and for example, the blocking portion may be configured by closing the fuel gas supply hole portion 72a and the fuel gas discharge hole portion 72b formed through the dummy first separator 108. It is. As shown in FIG. 14, the surface 108a of the dummy first separator 108 is provided with a seal member 127 that surrounds the second space 126 and seals the inside thereof with the outside in the surface direction.

  As shown in FIG. 2, the first dummy cell 18 includes a first separator 32 (dummy separator), a dummy structure 106 with a resin frame, and a dummy first separator 108 (dummy) from the arrow A1 side to the arrow A2 side. A separator), a dummy structure 106 with a resin frame, and a dummy second separator 130 (dummy separator) are stacked in this order.

  As shown in FIGS. 2, 3 and 14, the dummy second separator 130 is provided with an inlet blocking part 122a instead of the fuel gas supply hole 72a, and an outlet blocking part 122b instead of the fuel gas discharge hole 72b. Is configured in the same manner as the third separator 38 except that is provided.

  That is, as shown in FIG. 2, FIG. 3, and FIG. 6, the surface 130 b on the other end side (arrow A <b> 2 side) of the dummy second separator 130 Except that the discharge hole 72b is not provided, the third separator 38 is configured in the same manner as the surface 38b on the arrow A2 side. Therefore, the surface 130b of the dummy second separator 130 can be configured similarly to the surface 32a on one end side (arrow A1 side) of the first separator 32 shown in FIG. Further, as shown in FIGS. 2 and 14, the surface 130 a on the arrow A <b> 1 side of the dummy second separator 130 is configured in the same manner as the surface 108 a on the arrow A <b> 1 side of the dummy first separator 108.

  As shown in FIG. 2, in the first dummy cell 18, a cooling medium flow path 52 is provided between the surface 130 b on the arrow A <b> 2 side of the dummy second separator 130 and the first separator 32 of the first end power generation unit 16. It is done. 2 and 11, in the first dummy cell 18, the surface (130a) of the dummy second separator 130 on the arrow A1 side and the third conductive porous body 116 side of the dummy structure 106 with a resin frame (arrow) A second space 126 corresponding to the fuel gas channel 66 is provided between the second space 126 and the A2 side).

  The second dummy cell 20 is laminated in the order of the first separator 32 (dummy separator), the dummy structure with resin frame 106, and the dummy second separator 130 (dummy separator) from the arrow A1 side to the arrow A2 side. For this reason, in the second dummy cell 20, a second gap is formed between the surface 130a on the arrow A1 side of the dummy second separator 130 and the third conductive porous body 116 side (arrow A2 side) of the dummy structure 106 with a resin frame. A space 126 is provided. The third dummy cell 24 is configured similarly to the second dummy cell 20.

  The second end power generation unit 22 includes a first separator 32, an MEA 34 with a resin frame, a second separator 36, a dummy structure 106 with a resin frame, and a dummy second separator from the arrow A1 side toward the A2 side. 130 are stacked in this order. Therefore, in the second end power generation unit 22, the space between the surface 130a on the arrow A1 side of the dummy second separator 130 and the third conductive porous body 116 side (arrow A2 side) of the dummy structure 106 with a resin frame. A second space 126 is provided.

  The terminal plates 26a and 26b are made of a material having electrical conductivity, and are made of a metal such as copper, aluminum, or stainless steel, for example. As shown in FIG. 1, terminal portions 132a and 132b extending outward in the stacking direction are provided at substantially the center of the terminal plates 26a and 26b, respectively.

  The terminal portion 132a is inserted into the insulating cylinder 134a, passes through the hole portion 136a of the insulator 28a and the hole portion 138a of the end plate 30a, and protrudes outside the end plate 30a. The terminal portion 132b is inserted into the insulating cylinder 134b, passes through the hole portion 136b of the insulator 28b and the hole portion 138b of the end plate 30b, and protrudes outside the end plate 30b.

  The insulators 28a and 28b are formed of an insulating material such as polycarbonate (PC) or phenol resin. In the central portions of the insulators 28a and 28b, recesses 140a and 140b that open toward the laminated body 14 are formed, and the recesses 140a and 140b communicate with the holes 136a and 136b.

  The insulator 28a and the end plate 30a are provided with reaction gas communication holes. On the other hand, the cooling medium inlet communication hole 48 and the cooling medium outlet communication hole 50 are provided in the insulator 28b and the end plate 30b.

  The terminal plate 26a and the heat insulator 142 are accommodated in the recess 140a, and the terminal plate 26b and the heat insulator 142 are accommodated in the recess 140b. The heat insulator 142 is configured by sandwiching a heat insulating member 146 having electric conductivity between a pair of heat insulating plates 144 having electric conductivity. The heat insulating plate 144 is formed of, for example, a porous carbon plate having a flat shape, and the heat insulating member 146 is formed of a metal plate having a corrugated cross section.

  The heat insulating plate 144 may be made of the same material as the heat insulating member 146. Further, the heat insulator 142 may include one heat insulating plate 144 and one heat insulating member 146. Further, a resin spacer (not shown) may be interposed between the terminal plates 26a, 26b and the bottoms of the recesses 140a, 140b of the insulators 28a, 28b.

  The fuel cell stack 10 is basically configured as described above. Hereinafter, the manufacturing method of the dummy cell according to the present embodiment will be described by taking as an example the case of obtaining the first dummy cell 18 of the fuel cell stack 10.

  First, as shown in FIGS. 11 to 13, after the second conductive porous body 114 is laminated on the third conductive porous body 116 via the second adhesive layer 119 b, the second conductive porous body 116 is stacked. A first laminating step of laminating the first conductive porous body 112 on the material body 114 via the first adhesive layer 119a is performed.

  For example, in the first stacking step, the second adhesive layer 119b is provided on at least one of the third conductive porous body 116 and the second conductive porous body 114. Specifically, when the third conductive porous body 116 and the second conductive porous body 114 are stacked, the connection is intermittent along the long side of the rectangular portion that forms the second stacked portion 114c. Thus, a second adhesive layer 119b is provided. Thereafter, the third conductive porous body 116 and the second conductive porous body 114 are stacked to form the second stacked portion 114c.

  In addition, a first adhesive layer 119a is provided on at least one of the second conductive porous body 114 and the first conductive porous body 112. Specifically, when the second conductive porous body 114 and the first conductive porous body 112 are stacked, the connection is intermittent along the long side of the rectangular portion that forms the first stacked portion 112b. Thus, a first adhesive layer 119a is provided. At this time, the first adhesive layer 119a and the second adhesive layer 119b are arranged so that positions in the stacking direction (arrows A1 and A2 directions) do not overlap each other. Thereafter, the first conductive porous body 112 is stacked on the second conductive porous body 114 to form the first stacked portion 112b.

  Next, the first adhesive layer 119a and the second adhesive layer 119b are cured to form the first bonding layer 118a and the second bonding layer 118b, respectively, thereby performing a curing process for obtaining the dummy structure 110. In this curing process, the first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 that are stacked in the first stacking process are applied to the fuel cell stack 10 during a power generation operation. The first adhesive layer 119a and the second adhesive layer 119b are cured in a state where a surface pressure having the same size as the surface pressure applied (for example, about 1.0 to 10.0 MPa) is applied, and the first bonding is performed. A layer 118a and a second bonding layer 118b are formed.

  Next, as shown in FIG. 9 and FIG. 10, a resin frame joint is obtained by providing a dummy resin frame member 111 so as to go around the outer periphery of the dummy structure 110 obtained in the curing step, thereby obtaining a dummy structure 106 with a resin frame. Perform the process.

  Specifically, the arrow A1 side of the outer peripheral exposed portion 116a of the third conductive porous body 116 is overlapped with the shelf 82e of the dummy resin frame member 111, and the outer peripheral exposed portion 114b of the second conductive porous body 114 is placed. The outer peripheral end surface 112a of the first conductive porous body 112 is opposed to the inner peripheral end surface 82i of the dummy resin frame member 111 so as to face the thin portion 82g of the dummy resin frame member 111. At this time, the arrow A1 side of the outer peripheral exposed portion 114b of the second conductive porous body 114 is in contact with the protruding end surface of the bank portion 82h.

  Then, the resin protrusion 120a provided on the dummy resin frame member 111 is melted and deformed by applying a load while being heated by a heating device (not shown), so that the second resin-impregnated portion 120b and the second melt-solidified portion 120c A second joint 120 is formed. Thereby, the dummy structure body 106 with a resin frame can be obtained by joining the shelf 82e of the dummy resin frame member 111 and the outer peripheral edge portion of the third conductive porous body 116.

  After obtaining the two resin frame dummy structures 106 as described above, as shown in FIG. 2, the first separator 32, the resin frame dummy structure 106, the dummy first separator 108, and the resin frame dummy A second stacking step is performed in which the structure 106 and the dummy second separator 130 are stacked in this order. Thus, the first dummy cell 18 can be obtained.

  The second dummy cell 20 and the third dummy cell 24 can be obtained by sandwiching the dummy structure 106 with a resin frame between the first separator 32 and the dummy second separator 130. In addition, the separator which can comprise the 2nd dummy cell 20 and the 3rd dummy cell 24 is not limited above. For example, in the second dummy cell 20, the dummy first separator 108 is stacked on the arrow A1 side of the dummy structure 106 with a resin frame, and the first separator 32 is stacked on the arrow A2 side of the dummy structure 106 with a resin frame. It may be configured. The third dummy cell 24 is configured by laminating the first separator 32 on the arrow A1 side of the dummy structure 106 with a resin frame and laminating the dummy first separator 108 on the arrow A2 side of the dummy structure 106 with a resin frame. May be.

  The operation of the fuel cell stack 10 including the first dummy cell 18, the second dummy cell 20, and the third dummy cell 24 obtained 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 40 of the end plate 30a. Fuel gas such as hydrogen-containing gas is supplied to the fuel gas inlet communication hole 44 of the end plate 30a. A cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium inlet communication hole 48 of the end plate 30b.

  As shown in FIGS. 4 and 5, the oxidant gas supplied to the oxidant gas inlet communication hole 40 passes through the oxidant gas flow path 56 and the first through the communication path 125 formed in the inlet connection groove 62a. It flows into one space 124. As a result, the oxidant gas is supplied to the cathode electrode 86 of each electrolyte membrane / electrode structure 80 and the dummy structure 110 while moving in the directions of arrows B1 and B2.

  As shown in FIG. 3, the fuel gas supplied to the fuel gas inlet communication hole 44 flows into the fuel gas channel 66 of the second separator 36 and the third separator 38 via the fuel gas supply hole 72a. . As a result, the fuel gas is supplied to the anode electrode 88 of each electrolyte membrane / electrode structure 80 while moving in the directions of arrows B1 and B2. On the other hand, as shown in FIG. 14, the inflow of fuel gas is blocked in the second space 126 of the dummy first separator 108 and the dummy second separator 130 by the inlet blocking portion 122a.

  In the electrolyte membrane / electrode structure 80 supplied with the reaction gas as described above, the oxidant gas supplied to each cathode electrode 86 and the fuel gas supplied to each anode electrode 88 are the first electrode catalyst. In the layer 90 and the second electrode catalyst layer 94, power is generated by being consumed by an electrochemical reaction.

  Next, the oxidant gas, which is supplied to each cathode electrode 86 and partially consumed, passes from the oxidant gas flow path 56 and the first space 124 through the communication path 125 formed in the outlet connection groove 62b. The oxidant gas outlet communication hole 46 is then discharged. Then, the gas is discharged to the outside of the fuel cell stack 10 through the oxidant gas outlet communication hole 46 of the end plate 30a.

  Similarly, the fuel gas partially consumed by being supplied to each anode electrode 88 is discharged from the fuel gas flow channel 66 to the fuel gas outlet communication hole 42 through the inside of the fuel gas discharge hole 72b. Then, the fuel is discharged outside the fuel cell stack 10 through the fuel gas outlet communication hole 42 of the end plate 30a.

  At this time, the second space 126 is also blocked from the fuel gas outlet communication hole 42 by the outlet blocking portion 122b. Therefore, as described above, in addition to the inflow of fuel gas being blocked by the inlet blocking portion 122a, the fuel gas enters the second space 126 from the fuel gas outlet communication hole 42 by the outlet blocking portion 122b. Has also been avoided. As a result, the second space 126 functions as a heat insulating space by blocking the flow of the fuel gas by the blocking portion.

  The cooling medium supplied to each cooling medium inlet communication hole 48 includes the cooling medium flow path 52 between the dummy second separator 130 and the first separator 32 adjacent to each other, and the third separator 38 and the first separator adjacent to each other. 32 is introduced into the cooling medium flow path 52 between them. The cooling medium introduced from each cooling medium inlet communication hole 48 on the arrow C1 side and the cooling medium introduced from the cooling medium inlet communication hole 48 on the arrow C2 side are along the directions of arrows C1 and C2 so as to approach each other. After flowing, flow toward the arrow B2 side, flow along the directions of arrows C1 and C2 so as to be separated from each other while cooling the electrolyte membrane / electrode structure 80, and from each cooling medium outlet communication hole 50 Discharged.

  As described above, each dummy cell (the first dummy cell 18, the second dummy cell 20, and the third dummy cell 24) of the fuel cell stack 10 according to the present embodiment is a dummy corresponding to the electrolyte membrane / electrode structure 80 of the power generation cell 12. A structure 110 is provided. That is, since each dummy cell does not include the electrolyte membrane 84, the first electrode catalyst layer 90, and the second electrode catalyst layer 94, power generation is not performed, and water generated by power generation is not generated. Thereby, each dummy cell itself functions as a heat insulation layer, and it can suppress that dew condensation occurs in each dummy cell.

  By disposing the first dummy cell 18 and the second dummy cell 20 at the end of the stacked body 14 on the arrow A1 side, and disposing the third dummy cell 24 at the end of the stacked body 14 on the arrow A2 side, The heat insulation on the end side of the laminate 14 can be enhanced. For this reason, it can suppress that the temperature of the edge part side of the laminated body 14 becomes low temperature compared with the center side also in a low temperature environment.

  Furthermore, since the heat insulation on the end side of the stacked body 14 can be improved, even when the fuel cell stack 10 is started in a sub-freezing environment, the entire stacked body 14 can be effectively heated. As a result, it is possible to suppress the generation of water or the like from freezing on the end side of the laminate 14 and causing a voltage drop.

  In the dummy structure 110 of each dummy cell, the first bonding layer 118a for bonding the first conductive porous body 112 and the second conductive porous body 114, the second conductive porous body 114, and the third conductive porous body. The positions in the stacking direction of the second bonding layer 118b that bonds the material body 116 are different from each other. For this reason, for example, compared with the case where the 1st joining layer 118a and the 2nd joining layer 118b are provided in the same position in the lamination direction, it can control that the thickness of each dummy cell increases partially. According to each of the dummy cells, even when stacked on the power generation cell 12, it is possible to suppress a local increase in surface pressure in the power generation cell 12, so that creep or the like occurs in the electrolyte membrane 84 and the electrolyte membrane 84. It is possible to suppress a decrease in durability.

  As described above, according to the fuel cell stack 10, the power generation stability can be achieved without reducing the durability of the electrolyte membrane 84 by each dummy cell that can be stacked on the power generation cell 12 while suppressing a local increase in surface pressure. It becomes possible to improve.

  As described above, in the fuel cell stack 10, the first bonding layer 118a is intermittently provided at the edge of the first stacked portion 112b, and the second bonding layer 118b is intermittently connected to the edge of the second stacked portion 114c. It was decided to be provided. In this case, the dummy structure 110 can be obtained by a simpler process than providing the first bonding layer 118a and the second bonding layer 118b continuously at the edges of the first stacked portion 112b and the second stacked portion 114c. Therefore, the manufacturing efficiency of the fuel cell stack 10 can be improved.

  As described above, in the fuel cell stack 10, the first bonding layers 118a and the second bonding layers 118b are alternately arranged in the circumferential direction of the first stacked portions 112b and the second stacked portions 114c. In this case, the first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 can be joined with sufficient strength by a simple joining process, It is possible to effectively suppress a local increase in the surface pressure in the power generation cells 12 stacked on each dummy cell.

  As described above, in the fuel cell stack 10, the planar dimensions of the first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 are rectangular, The first bonding layer 118a and the second bonding layer 118b are provided on the long sides excluding the rectangular short side. In this case, since it is possible to suppress an increase in internal resistance caused by stacking each dummy cell on the power generation cell 12, each dummy cell can be incorporated into the fuel cell stack 10 without affecting the power generation performance.

  In the curing process, the first conductive porous body 112, the second conductive porous body 114, and the third conductive porous body 116 stacked in the first stacking process are subjected to the power generation operation of the fuel cell stack 10. The first adhesive layer 119a and the second adhesive layer 119b were cured in a state where a surface pressure of the same magnitude as the applied surface pressure was applied. In each dummy cell in which the first bonding layer 118a and the second bonding layer 118b are formed in a state where the surface pressure is applied in this manner, when the fuel cell stack 10 is assembled, the surface pressure rises locally on the power generation cell 12. Can be more effectively suppressed.

  The present invention is not particularly limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.

  For example, if the positions of the first bonding layer 118a and the second bonding layer 118b are different from each other in the stacking direction, the shape and the number of the first bonding layer 118a and the second bonding layer 118b, and other arrangements with respect to the first stacking portion 112b and the second stacking portion 114c, etc. The invention is not particularly limited to the above-described embodiment. For example, the first bonding layer 118a and the second bonding layer 118b may be provided on both the long side and the short side of the first stacked unit 112b and the second stacked unit 114c, or may be provided only on the short side. May be. The first bonding layer 118a and the second bonding layer 118b are not limited to being provided at the outer peripheral edge portions of the first stacked portion 112b and the second stacked portion 114c, and may be provided at the center portion or the outer peripheral edge portion. And may be provided in both the central portion.

  In addition, the first bonding layer 118a and the second bonding layer 118b may not be provided alternately with respect to the first stacked unit 112b and the second stacked unit 114c, or may be provided continuously. Good.

  In the fuel cell stack 10 according to the above embodiment, the first end power generation unit 16, the first dummy cell 18, and the second dummy cell 20 are stacked on the arrow A1 side of the stacked body 14, and the arrow A2 of the stacked body 14 is stacked. The second end power generation unit 22 and the third dummy cell 24 are stacked on the side.

  In this way, a larger number of dummy cells are arranged on the arrow A1 side of the laminate 14, in other words, on the arrow A2 side of the laminate 14, in other words, on the oxidant gas outlet side. By doing so, it was possible to more effectively suppress the entry of condensed water into the power generation cell 12. However, the fuel cell stack 10 only needs to include a dummy cell on at least one end side in the stacking direction of the stacked body 14, and the number of the dummy cells is not particularly limited.

  Further, by interposing the first end power generation unit 16 or the second end power generation unit 22 between the power generation cell 12 and the first dummy cell 18 or the third dummy cell 24, at both ends of the stacked body 14 in the stacking direction. The electrolyte membrane / electrode structure 80 in the first end power generation unit 16 and the second end power generation unit 22 that generate power can be cooled under the same conditions as other electrolyte membrane / electrode structures 80. . As a result, since the balance between heat generation and cooling in the entire laminated body 14 can be made equal, further improvement in power generation performance and power generation stability can be achieved.

  However, the first end power generation unit 16 and the second end power generation unit 22 are not indispensable components, and the fuel cell stack 10 includes either the first end power generation unit 16 or the second end power generation unit 22. May be provided, or none may be provided.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell stack 12 ... Power generation cell 14 ... Laminated body 18 ... 1st dummy cell 106 ... Dummy structure with a resin frame 110 ... Dummy structure 111 ... Dummy resin frame member 112 ... 1st electroconductive porous body 112b ... 1st Laminated portion 114 ... second conductive porous body 114c ... second laminated portion 116 ... third conductive porous body 118a ... first bonding layer 118b ... second bonding layer 119a ... first adhesive layer 119b ... second bonding Agent layer

Claims (12)

An electrolyte membrane / electrode structure in which electrodes each having a gas diffusion layer made of a conductive porous body are disposed on both sides of the electrolyte membrane; a resin frame member that circulates around an outer periphery of the electrolyte membrane / electrode structure; A fuel cell stack comprising a laminate in which a plurality of power generation cells having a separator sandwiching an electrolyte membrane / electrode structure is laminated, and a dummy cell disposed at at least one end in the lamination direction of the laminate,
The dummy cell includes a dummy structure corresponding to the electrolyte membrane / electrode structure, a dummy resin frame member that goes around an outer periphery of the dummy structure, and a dummy separator that sandwiches the dummy structure,
The dummy structure is formed by laminating a first conductive porous body, a second conductive porous body, and a third conductive porous body having different planar dimensions in this order in the stacking direction,
A first bonding layer which is interposed between the first conductive porous body and the second conductive porous body to bond each other; the second conductive porous body; and the third conductive porous body. The fuel cell stack is characterized in that the positions in the stacking direction are different from each other between the second bonding layer that is interposed between the second bonding layers that are bonded to each other. The fuel cell stack according to claim 1, wherein
The first bonding layer is intermittently provided at an edge of a first laminated portion that is a laminated portion of the first conductive porous body and the second conductive porous body,
The fuel cell stack, wherein the second bonding layer is intermittently provided at an edge of a second stacked portion that is a stacked portion of the second conductive porous body and the third conductive porous body. . The fuel cell stack according to claim 2, wherein
The fuel cell stack, wherein the first bonding layer and the second bonding layer are alternately arranged in a circumferential direction of the first stacked portion and the second stacked portion. The fuel cell stack according to any one of claims 1 to 3,
The planar dimensions of each of the first conductive porous body, the second conductive porous body, and the third conductive porous body are rectangular, and the long sides excluding the short sides of the rectangular shape A fuel cell stack comprising a first bonding layer and the second bonding layer. The fuel cell stack according to any one of claims 1 to 4,
The second conductive porous body has a larger planar dimension than the first conductive porous body,
The third conductive porous body has a larger planar dimension than the second conductive porous body,
The dummy resin frame member includes an outer peripheral edge, a shelf protruding inward from the inner peripheral end of the outer peripheral edge through the first step surface, and an inner peripheral end of the shelf. A thin portion protruding inward over the entire circumference through the second step surface,
The outer peripheral edge of the third conductive porous body overlaps the shelf of the dummy resin frame member,
The outer peripheral edge of the second conductive porous body faces the thin portion of the dummy resin frame member,
The fuel cell stack, wherein an outer peripheral end surface of the first conductive porous body is opposed to an inner peripheral end surface of the dummy resin frame member. The fuel cell stack according to claim 5, wherein
The fuel cell stack, wherein a thickness of the second conductive porous body is larger than a height of the second step surface. The fuel cell stack according to claim 5 or 6,
A fuel cell stack, wherein a space is formed between the thin portion of the dummy resin frame member and the third conductive porous body. An electrolyte membrane / electrode structure in which electrodes each having a gas diffusion layer made of a conductive porous body are disposed on both sides of the electrolyte membrane; a resin frame member that circulates around an outer periphery of the electrolyte membrane / electrode structure; A method of manufacturing a dummy cell disposed at at least one end in a stacking direction of a stack of a fuel cell stack including a stack of a plurality of power generation cells each having a separator sandwiching an electrolyte membrane / electrode structure. ,
The first conductive porous body, the second conductive porous body, the third conductive porous body, the first conductive porous body, and the second conductive porous body, each having different planar dimensions. A first adhesive layer interposed therebetween, and a second adhesive layer interposed between the second conductive porous body and the third conductive porous body to be stacked in the stacking direction. Lamination process;
A first bonding layer for curing the first adhesive layer and the second adhesive layer to bond the first conductive porous body and the second conductive porous body, and the second conductive A curing step of obtaining a dummy structure corresponding to the electrolyte membrane / electrode structure by forming a second bonding layer for bonding the porous body and the third conductive porous body,
A resin frame joining step for obtaining a dummy structure with a resin frame by providing a dummy resin frame member around the outer periphery of the dummy structure to the dummy structure;
A second stacking step of obtaining the dummy cell by sandwiching the dummy structure with a resin frame with a dummy separator;
Have
By providing the first adhesive layer and the second adhesive layer so that the positions in the laminating direction are different from each other in the first laminating step, the positions in the laminating direction are different from each other in the curing step. A method for manufacturing a dummy cell, comprising forming one bonding layer and the second bonding layer. In the manufacturing method of the dummy cell of Claim 8,
In the curing step, during the power generation operation of the fuel cell stack, the first conductive porous body, the second conductive porous body, and the third conductive porous body stacked in the first stacking step A method for manufacturing a dummy cell, comprising: curing the first adhesive layer and the second adhesive layer in a state where a surface pressure equal to the surface pressure applied is applied. In the manufacturing method of the dummy cell of Claim 8 or 9,
In the first laminating step, the first adhesive layer is provided intermittently at an edge of the first laminating portion that is a laminating portion of the first conductive porous body and the second conductive porous body, A method for manufacturing a dummy cell, characterized in that the second adhesive layer is intermittently provided at an edge of a second laminated portion which is a laminated portion of the second conductive porous body and the third conductive porous body. In the manufacturing method of the dummy cell of Claim 10,
In the first stacking step, the first adhesive layer and the second adhesive layer are alternately arranged in the circumferential direction of the first stack portion and the second stack portion. Method. In the manufacturing method of the dummy cell of any one of Claims 8-11,
In the first laminating step, on the long sides except the short sides of the first conductive porous body, the second conductive porous body, and the third conductive porous body, each of which has a rectangular planar dimension. A method for manufacturing a dummy cell, comprising providing the first adhesive layer and the second adhesive layer.

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