JP2014175115A - Fuel cell stack - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell stack, having a simple and compact configuration, capable of increasing a distribution property of a reaction gas supplied to an end cell and ensuring power generation performance of the end cell successfully.SOLUTION: A fuel cell stack 10 comprises a laminate 14 where a plurality of power generation cells 12 are stacked. Insulators 18a and 18b are arranged at both ends of the laminate 14. A heat insulating member 70b and a terminal plate 16b are stored in a recessed storing part 66b of the insulator 18b. A recess 74a which communicates with a fuel gas supply communication hole 38a is formed at a surface of the insulator 18b at the side of the laminate 14.

Description

  The present invention includes a laminate in which a power generation cell having an electrolyte / electrode structure in which electrodes are disposed on both sides of an electrolyte and a separator is laminated, and a terminal plate, an insulator, and an insulator on both sides in the lamination direction of the laminate The present invention relates to a fuel cell stack provided with an end plate.

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

  Normally, a fuel cell is used as a fuel cell stack in which a predetermined number (for example, several tens to several hundreds) of power generation cells are stacked in order to obtain a desired power generation. For this reason, it is difficult to evenly distribute the reaction gas (fuel gas and oxidant gas) to each power generation cell in the fuel cell stack.

  Thus, for example, a fuel cell stack disclosed in Patent Document 1 has been proposed for the purpose of evenly distributing the reaction gas to each power generation cell. In this fuel cell stack, a plurality of fuel cells are stacked, and each fuel cell receives fuel gas, oxidant gas or cooling medium from an inlet manifold arranged in the stacking direction at the peripheral portion of the stacked fuel cells. It is configured to flow into the gas flow path or cooling medium flow path formed in the cell, and to discharge from each gas flow path or cooling medium flow path to the outlet manifold arranged in the stacking direction on the periphery of the fuel cell. Has been.

  The fuel cell stack has at least one outlet manifold of fuel gas, oxidant gas or cooling medium at the outlet of the gas channel or cooling medium channel formed in each fuel cell from the upstream region to the downstream region. Partitioning means to be divided into a first chamber facing and communicating with the second chamber and a second chamber communicating with the discharge port to the outside of the fuel cell stack, the first chamber and the second chamber provided in the partitioning means And communication means for communicating with the chamber through the communication port.

  For this reason, even in the outlet manifold where the pressure difference between the upstream and downstream generated by the flow in the stacking direction is large, the stacking direction pressure distribution in the vicinity of the outflow part from the flow path of each fuel cell in the outlet manifold is relaxed, and each The fluid distribution to the fuel cells can be made uniform.

JP 2009-43542 A

  However, in the above fuel cell stack, partition means for dividing the outlet manifold into the first chamber and the second chamber is disposed in the outlet manifold. For this reason, the outlet manifold has a considerably large opening shape, and there is a problem that the entire fuel cell stack is enlarged.

  In addition, dedicated partition means are used. Therefore, there are problems that the number of parts increases and the assembly work becomes complicated. Furthermore, even if the partitioning means is used, there is a possibility that the fluid may not be smoothly supplied to the fuel cells arranged at the extreme end in the stacking direction.

  The present invention solves this type of problem, and can improve the distribution of the reaction gas to the end cells with a simple and compact configuration, and further improve the power generation performance of the end cells. An object of the present invention is to provide a fuel cell stack that can be secured.

  The present invention includes a laminate in which a power generation cell having an electrolyte / electrode structure in which electrodes are disposed on both sides of an electrolyte and a separator is laminated, and a terminal plate, an insulator, and an insulator on both sides in the lamination direction of the laminate An end plate is disposed, and at least a reaction gas that is a fuel gas or an oxidant gas is circulated along an electrode surface, and communicated with an inlet side of the reaction gas channel, and the reaction gas A reaction gas supply communication hole through which the reaction gas flows in the stacking direction and a reaction gas discharge communication hole through which the reaction gas flows in the stacking direction. It is.

  In this fuel cell stack, one end plate is formed with a reaction gas inlet communicating with the reaction gas supply communication hole and a reaction gas outlet communicating with the reaction gas discharge communication hole, and on the other end plate side. The adjacent insulator is formed with a recess that communicates with at least the reaction gas supply passage.

  Further, in this fuel cell stack, it is preferable that the opening cross-sectional shape of the recess is set to at least the same shape as the opening cross-sectional shape of the reaction gas supply communication hole.

  Furthermore, in this fuel cell stack, it is preferable that an inclined surface inclined downward at least toward the bottom surface of the reaction gas supply communication hole is formed on the bottom surface in the gravity direction of the recess.

  Furthermore, in this fuel cell stack, it is preferable that the insulator is provided with a concave accommodating portion on a surface facing the laminated body, and a heat insulating member and a terminal plate are accommodated in the concave accommodating portion.

  According to the present invention, the insulator disposed on the deep side of the reaction gas supply communication hole is formed with a recess communicating with the reaction gas supply communication hole. For this reason, the insulator can have a chamber (concave portion) that continues to the reaction gas supply communication hole. Therefore, the reaction gas can be smoothly and reliably introduced into the power generation cell adjacent to the insulator having the recess, that is, the end cell.

  Thereby, it is possible to improve the distribution of the reaction gas to the end cells with a simple and compact configuration, and to secure the power generation performance of the end cells.

1 is a perspective explanatory view of a fuel cell stack according to a first embodiment of the present invention. FIG. 2 is a partially exploded schematic perspective view of the fuel cell stack. FIG. 3 is a cross-sectional view of the fuel cell stack taken along line III-III in FIG. 2. It is a disassembled perspective explanatory drawing of the power generation cell which comprises the said fuel cell stack. FIG. 4 is a partially exploded schematic perspective view of a fuel cell stack according to a second embodiment of the present invention. FIG. 6 is a cross-sectional view of the fuel cell stack taken along line VI-VI in FIG. 5. It is principal part cross-sectional explanatory drawing of the fuel cell stack which concerns on the 3rd Embodiment of this invention. FIG. 6 is a partially exploded schematic perspective view of a fuel cell stack according to a fourth embodiment of the present invention. FIG. 9 is a cross-sectional view of the fuel cell stack taken along line IX-IX in FIG. 8.

  As shown in FIGS. 1 and 2, the fuel cell stack 10 according to the first embodiment of the present invention includes a stacked body 14 in which a plurality of power generation cells 12 are stacked in the horizontal direction (arrow A direction). A terminal plate 16a, an insulator (insulating plate) 18a, and an end plate 20a are sequentially disposed at one end in the stacking direction (arrow A direction) of the stacked body 14 (see FIG. 2). At the other end in the stacking direction of the stacked body 14, a terminal plate 16b, an insulator (insulating plate) 18b, and an end plate 20b are sequentially disposed outward.

  As shown in FIG. 1, the end plates 20 a and 20 b have a horizontally long (or vertically long) rectangular shape, and a connecting bar 24 is disposed between each side. Each connecting bar 24 is fixed at both ends to the inner surfaces of the end plates 20a and 20b via bolts 26, and applies a tightening load in the stacking direction (arrow A direction) to the plurality of stacked power generation cells 12. Note that the fuel cell stack 10 may include a housing having end plates 20a and 20b as end plates, and the stacked body 14 may be accommodated in the housing.

  As shown in FIGS. 3 and 4, the power generation cell 12 includes an electrolyte membrane / electrode structure 30 sandwiched between a first separator 32 and a second separator 34. The first separator 32 and the second separator 34 are configured by, for example, pressing a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a metal thin plate having a metal surface subjected to a surface treatment for anticorrosion into a corrugated shape. Although a metal separator is employed, for example, a carbon separator may be used.

  One end edge of the power generation cell 12 in the direction of arrow B (horizontal direction in FIG. 4) communicates with each other in the direction of arrow A, which is the stacking direction, and oxidant for supplying an oxidant gas, for example, an oxygen-containing gas An agent gas supply communication hole (reaction gas supply communication hole) 36a and a fuel gas discharge communication hole (reaction gas discharge communication hole) 38b for discharging a fuel gas, for example, a hydrogen-containing gas, are provided in the arrow C direction (vertical direction). Are provided in an array.

  A fuel gas supply communication hole (reactive gas supply communication hole) 38a for communicating with each other in the direction of arrow A to supply fuel gas and an oxidant gas are connected to the other end edge of the power generation cell 12 in the direction of arrow B. Oxidant gas discharge communication holes (reactive gas discharge communication holes) 36b for discharge are arranged in the direction of arrow C.

  A cooling medium supply communication hole 40a is provided at the upper edge of the power generation cell 12 in the arrow C direction so as to communicate with each other in the arrow A direction and supply a cooling medium. A cooling medium discharge communication hole 40 b for discharging the cooling medium is provided at the lower edge of the power generation cell 12 in the arrow C direction so as to communicate with each other in the arrow A direction.

  An oxidant gas flow path (reactive gas flow path) 42 communicating with the oxidant gas supply communication hole 36 a and the oxidant gas discharge communication hole 36 b is formed on the surface 32 a of the first separator 32 facing the electrolyte membrane / electrode structure 30. Is provided. The oxidant gas flow channel 42 has a plurality of flow channel grooves extending in the horizontal direction (arrow B direction).

  A surface 34a of the second separator 34 facing the electrolyte membrane / electrode structure 30 is provided with a fuel gas flow path (reactive gas flow path) 44 communicating with the fuel gas supply communication hole 38a and the fuel gas discharge communication hole 38b. . The fuel gas channel 44 has a plurality of channel grooves extending in the horizontal direction (arrow B direction).

  A cooling medium that connects the cooling medium supply communication hole 40a and the cooling medium discharge communication hole 40b between the surface 32b of the first separator 32 and the surface 34b of the second separator 34 that constitute the power generation cells 12 adjacent to each other. A flow path 46 is provided.

  The first separator 32 and the second separator 34 are respectively provided with seal members 48 and 50 integrally or individually. As the sealing members 48 and 50, for example, EPDM, NBR, fluorine rubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene, acrylic rubber or the like sealing material, cushioning material, packing material, etc. A seal member having the following elasticity is used.

  The electrolyte membrane / electrode structure 30 includes, for example, a solid polymer electrolyte membrane 52 in which a perfluorosulfonic acid thin film (or hydrocarbon-based membrane) is impregnated with water, and a cathode electrode sandwiching the solid polymer electrolyte membrane 52 54 and an anode electrode 56.

  The solid polymer electrolyte membrane 52 has a larger planar dimension (surface dimension) than the cathode electrode 54 and the anode electrode 56. The electrolyte membrane / electrode structure 30 may constitute a step MEA in which the cathode electrode 54 and the anode electrode 56 are set to different plane dimensions (surface dimensions).

  The cathode electrode 54 and the anode electrode 56 are an electrode catalyst formed by uniformly applying a gas diffusion layer made of carbon paper or the like and porous carbon particles carrying a platinum alloy on the surface thereof to the surface of the gas diffusion layer. And having a layer. The electrode catalyst layers are formed on both surfaces of the solid polymer electrolyte membrane 52.

  As shown in FIG. 2, terminal portions 58a and 58b extending outward in the stacking direction are provided at substantially the center of the terminal plates 16a and 16b. The terminal portions 58a and 58b are inserted into the insulating cylinder 60 and penetrate the holes 62a and 62b of the insulators 18a and 18b and the holes 64a and 64b of the end plates 20a and 20b. Protruding outside.

  An oxidant gas supply communication hole 36a, an oxidant gas discharge communication hole 36b, a fuel gas supply communication hole 38a, and a fuel gas discharge communication hole 38b are formed in the end plate 20a. A cooling medium supply communication hole 40a and a cooling medium discharge communication hole 40b are formed in the end plate 20b. Although not shown in the figure, the end plate 20a has an oxidant gas supply communication hole 36a, an oxidant gas discharge communication hole 36b, a fuel gas supply communication hole 38a, and a fuel gas discharge communication hole 38b, for example, by an insulating grommet. An insulating coating is provided to ensure insulation. The end plate 20b is provided with an insulating film such as an insulating grommet on the inner periphery of the cooling medium supply communication hole 40a and the cooling medium discharge communication hole 40b to ensure insulation.

  The insulators 18a and 18b are made of an insulating material such as polycarbonate (PC) or phenol resin. In the central part of the insulators 18a and 18b, concave housing portions 66a and 66b are formed, which are open at the end on the laminated body 14 side. The holes 62a and 62b communicate with the approximate center of the bottom surfaces 68a and 68b constituting the concave accommodating portions 66a and 66b.

  As shown in FIGS. 2 and 3, the recessed housing portion 66a houses the heat insulating member 70a and the terminal plate 16a. The heat insulating member 70b and the terminal plate 16b are accommodated in the concave accommodating portion 66b.

  The heat insulating member 70a includes a corrugated metal plate 32P obtained by cutting the outer periphery of the first separator 32 constituting the power generation cell 12 (laminated body 14) into a frame shape, and the outer periphery of the second separator 34 as a frame shape. For example, two sets of corrugated metal plates 34P cut into two are laminated. In the heat insulating member 70a, the plates 32P and 34P are brought into contact with each other to form a heat insulating space therebetween. The outer peripheral dimensions of the plates 32P and 34P are set to be equal to the inner peripheral dimension of the concave accommodating portion 66a of the insulator 18a.

  In addition, when the power generation cell 12 is composed of three different types of separators, three separators may be alternately stacked. Further, the heat insulating member 70a may be composed of one set or three or more sets of plates 32P and 34P, a plurality of single plates 32P may be stacked, or a plurality of single plates 34P may be stacked. You may laminate. Furthermore, instead of the metal separator for the power generation cell, a metal separator dedicated to the end may be used.

  The heat insulating member 70a may be any member that retains pores and has electrical conductivity, and is made of an electrically conductive foam metal, honeycomb-shaped metal (honeycomb member), or porous carbon (for example, carbon paper). You may comprise either. One heat insulating member 70a may be used, or a plurality of heat insulating members 70a may be stacked. In addition, the heat insulation member 70b is comprised similarly to said heat insulation member 70a, attaches | subjects the same referential mark to the same component, and abbreviate | omits the detailed description.

  As shown in FIG. 2, the insulator 18 b adjacent to the end plate 20 b (the other end plate) has an oxidant gas supply communication hole 36 a on the surface on the laminated body 14 side (surface on which the concave housing portion 66 b is provided). Recesses 72a, 72b, 74a, and 74b communicating with the oxidant gas discharge communication hole 36b, the fuel gas supply communication hole 38a, and the fuel gas discharge communication hole 38b are formed at predetermined depths, respectively. The opening cross-sectional shapes of the recesses 72a, 72b, 74a, and 74b are the same as the opening cross-sectional shapes of the oxidant gas supply communication hole 36a, the oxidant gas discharge communication hole 36b, the fuel gas supply communication hole 38a, and the fuel gas discharge communication hole 38b. Set to

  The insulator 18b may be provided with at least a recess 72a and a recess 74a facing the oxidant gas supply communication hole 36a and the fuel gas supply communication hole 38a. The recess 72b and the recess 74b facing the oxidant gas discharge communication hole 36b and the fuel gas discharge communication hole 38b can be provided as necessary.

  As shown in FIG. 3, in the second separator 34 disposed at the stacking direction end portion on the insulator 18 a side of the stacked body 14, the seal member 50 comes into contact with the frame-shaped end surface of the insulator 18 a. As for the 1st separator 32 arrange | positioned at the lamination direction edge part by the side of the insulator 18b of the laminated body 14, the sealing member 48 contact | abuts to the frame-shaped end surface of the said insulator 18b.

  The operation of the fuel cell stack 10 configured as described above will be described below.

  First, as shown in FIG. 1, an oxidant gas such as an oxygen-containing gas is supplied to the oxidant gas supply passage 36a of the end plate 20a. Fuel gas such as hydrogen-containing gas is supplied to the fuel gas supply communication hole 38a of the end plate 20a. A cooling medium such as pure water, ethylene glycol, or oil is supplied to the cooling medium supply communication hole 40a of the end plate 20b.

  As shown in FIG. 4, the oxidant gas is introduced into the oxidant gas flow path 42 of the first separator 32 from the oxidant gas supply communication hole 36 a. The oxidant gas is supplied to the cathode electrode 54 constituting the electrolyte membrane / electrode structure 30 while flowing in the horizontal direction (arrow B direction) along the oxidant gas flow path 42.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 44 of the second separator 34 from the fuel gas supply communication hole 38a. The fuel gas is supplied to the anode electrode 56 constituting the electrolyte membrane / electrode structure 30 while flowing in the horizontal direction (arrow B direction) along the fuel gas flow path 44.

  Therefore, in the electrolyte membrane / electrode structure 30, the oxidant gas supplied to the cathode electrode 54 and the fuel gas supplied to the anode electrode 56 are consumed by an electrochemical reaction in the electrode catalyst layer to generate power. Is called.

  Next, the oxidant gas supplied and consumed to the cathode electrode 54 is discharged in the direction of arrow A along the oxidant gas discharge communication hole 36b. On the other hand, the fuel gas consumed by being supplied to the anode electrode 56 is discharged in the direction of arrow A along the fuel gas discharge communication hole 38b.

  The cooling medium supplied to the cooling medium supply communication hole 40 a is introduced into the cooling medium flow path 46 between the first separator 32 and the second separator 34 and then circulates in the direction of arrow C. The cooling medium is discharged from the cooling medium discharge communication hole 40b after the electrolyte membrane / electrode structure 30 is cooled.

  In this case, in the first embodiment, as shown in FIG. 3, a recess 74a communicating with the fuel gas supply communication hole 38a is formed on the surface of the insulator 18b on the laminated body 14 side. Therefore, the fuel gas flowing in the stacking direction along the fuel gas supply communication hole 38a from the end plate 20a side passes through the stacked body 14 and is introduced into the recess 74a as a chamber.

  Therefore, in the power generation cell 12 arranged at the stacking direction end of the stacked body 14 on the insulator 18b side, that is, the end cell, the fuel gas is smoothly and reliably supplied from the fuel gas supply communication hole 38a to the fuel gas flow path 44. Is done.

  Further, the insulator 18b is formed with a recess 72a communicating with the oxidant gas supply communication hole 36a. Thus, the oxidant gas flowing in the stacking direction along the oxidant gas supply communication hole 36a from the end plate 20a side passes through the stacked body 14 and is introduced into the recess 72a as a chamber.

  For this reason, in the power generation cell 12 arranged at the stacking direction end of the laminate 14 on the insulator 18b side, that is, the end cell, the oxidant gas smoothly flows from the oxidant gas supply communication hole 36a to the oxidant gas flow path 42. And it is reliably supplied.

  Therefore, the distribution of the fuel gas and the oxidant gas to the end cells can be improved with a simple and compact configuration. And the effect that it becomes possible to ensure the electric power generation performance of an edge part cell favorably is acquired.

  Moreover, the heat insulation member 70a and the terminal plate 16a are accommodated in the concave accommodation part 66a of the insulator 18a. On the other hand, the heat insulating member 70b and the terminal plate 16b are accommodated in the concave accommodating portion 66b of the insulator 18b. Thereby, the heat radiation from the outer peripheral portions of the heat insulating members 70a and 70b and the terminal plates 16a and 16b can be satisfactorily suppressed, and the temperature drop of the end cells can be reliably prevented.

  FIG. 5 is a partially exploded schematic perspective view of a fuel cell stack 80 according to the second embodiment of the present invention. The same components as those of the fuel cell stack 10 according to the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted. Similarly, in the third and subsequent embodiments described below, detailed description thereof is omitted.

  The fuel cell stack 80 includes an insulator 82 instead of the insulator 18b. In the insulator 82, the oxidant gas supply communication hole 36 a, the oxidant gas discharge communication hole 36 b, the fuel gas supply communication hole 38 a, and the fuel gas discharge communication are formed on the surface on the laminated body 14 side (surface on which the concave housing portion 66 b is provided). Recesses 84a, 84b, 86a and 86b communicating with the hole 38b are respectively formed to a predetermined depth.

  The opening cross-sectional shapes of the recesses 84a, 84b, 86a and 86b are the same as the opening cross-sectional shapes of the oxidant gas supply communication hole 36a, the oxidant gas discharge communication hole 36b, the fuel gas supply communication hole 38a and the fuel gas discharge communication hole 38b. Set to In the gravity direction bottom surfaces of the recesses 84a, 84b, 86a and 86b, the oxidant gas supply communication hole 36a, the oxidant gas discharge communication hole 36b, the fuel gas supply communication hole 38a, and the fuel gas discharge communication hole 38b are directed downward. Inclined surfaces 88a, 88b, 90a and 90b are formed.

  As shown in FIG. 6, the inclined surface 90a formed on the bottom surface in the gravitational direction of the recess 86a is directed upward inward of the recess 86a with respect to the flow direction (arrow B direction) of the fuel gas supply communication hole 38a. Is inclined at an angle α °. The same applies to the other inclined surfaces 88a, 88b and 90b.

  In the second embodiment configured as described above, inclined surfaces 88a, 88b, 90a and 90b are formed on the bottom surfaces in the gravity direction of the recesses 84a, 84b, 86a and 86b. For this reason, as shown in FIG. 6, for example, when moisture stays in the recess 86a, when the moisture is condensed and condensed water 92 is generated, the condensed water 92 is laminated along the inclined surface 90a by gravity. Move to the 14th side. Therefore, the condensed water 92 does not stay in the recess 86a, and the effect that smooth supply of the fuel gas can be performed is obtained.

  Further, the insulator 82 having the recesses 84a, 84b, 86a and 86b is used, and the distribution of the fuel gas and the oxidant gas to the end cells can be improved with a simple and compact configuration. In addition, the same effects as those of the first embodiment can be obtained, such as ensuring good power generation performance of the end cells.

  FIG. 7 is an explanatory cross-sectional view of a main part of a fuel cell stack 100 according to the third embodiment of the present invention.

  The fuel cell stack 100 includes heat insulating members 102a and 102b instead of the heat insulating members 70a and 70b. The heat insulating members 102a and 102b include at least a first heat insulating member 104 and a second heat insulating member 106, which are made of different materials, and the first heat insulating member 104 and the second heat insulating member 106 are alternately stacked.

  The 1st heat insulation member 104 is comprised by the metal plate, for example, and can use at least any one of said plate 32P and 34P. The second heat insulating member 106 may be a member having a heat insulating mechanism, and for example, a carbon plate can be used. The second heat insulating member 106 is set to have a smaller outer dimension than the first heat insulating member 104.

  The heat insulating member 102a and the terminal plate 16a are accommodated in the concave accommodating portion 66a of the insulator 18a, and the heat insulating member 102b and the terminal plate 16b are accommodated in the concave accommodating portion 66b of the insulator 18b.

  In the third embodiment, the insulator 18b of the first embodiment is used. However, the present invention is not limited to this, and the insulator 82 of the second embodiment may be adopted.

  In the third embodiment configured as described above, interfacial thermal resistance is induced on the contact surface between the first heat insulating member 104 and the second heat insulating member 106 which are different members, and the heat insulating property is improved satisfactorily. Therefore, even if the 1st heat insulation member 104 and the 2nd heat insulation member 106 are comprised in thin wall shape, it becomes possible to ensure desired electricity supply and desired heat insulation.

  Further, the insulator 18b is used, and the distribution of the fuel gas and the oxidant gas to the end cells can be improved with a simple and compact configuration. Moreover, the same effects as those of the first and second embodiments described above can be obtained, such as ensuring good power generation performance of the end cells.

  The first heat insulating member 104 and the second heat insulating member 106 can be variously combined as long as the materials are different. Further, the number of stacked layers of the first heat insulating member 104 and the second heat insulating member 106 can be arbitrarily set. Further, the second heat insulating member 106 may be corrugated instead of flat.

  FIG. 8 is a partially exploded schematic perspective view of a fuel cell stack 110 according to the fourth embodiment of the present invention.

  The fuel cell stack 110 includes an insulator 112 instead of the insulator 18b, and includes an end plate 114 instead of the end plate 20b. In the insulator 112, openings 116 a and 116 b communicating with the oxidant gas supply communication hole 36 a, the oxidant gas discharge communication hole 36 b, the fuel gas supply communication hole 38 a, and the fuel gas discharge communication hole 38 b on the surface on the laminated body 14 side. , 118a and 118b are respectively formed through.

  In the end plate 114, recesses 120a, 120b, 122a, and 122b communicating with the openings 116a, 116b, 118a, and 118b are respectively formed on the surface on the insulator 112 side to a predetermined depth (see FIG. 9). Although not shown, the end plate 114 is provided with an insulating film such as an insulating grommet on the inner periphery of the recesses 120a, 120b, 122a, and 122b to ensure insulation. A seal member 124 is provided on the inner surface of the insulator 112 around the openings 116a, 116b, 118a, and 118b and the recesses 120a, 120b, 122a, and 122b to ensure sealing performance.

  In the fourth embodiment configured as above, the openings 116a, 116b, 118a and 118b and the recesses 120a, 120b, 122a and 122b are formed in communication with each other, particularly from the insulator 112 to the end plate 114. ing. Accordingly, an oxidant gas and fuel gas chamber is formed in the depth direction in the vicinity of the end cell. As a result, the oxidant gas and the fuel gas can be more smoothly supplied to the end cells, and the same effects as in the first to third embodiments can be obtained.

  In the fourth embodiment, the insulator 112 can be configured to be considerably thinner than the insulator 18b, for example. In that case, you may make the heat insulation member 70b unnecessary.

DESCRIPTION OF SYMBOLS 10, 80, 100, 110 ... Fuel cell stack 12 ... Power generation cell 14 ... Laminated body 16a, 16b ... Terminal plate 18a, 18b, 82, 112 ... Insulator 20a, 20b, 114 ... End plate 30 ... Electrolyte membrane and electrode structure 32, 34 ... separators 32P, 34P ... plate 36a ... oxidant gas supply communication hole 36b ... oxidant gas discharge communication hole 38a ... fuel gas supply communication hole 38b ... fuel gas discharge communication hole 40a ... cooling medium supply communication hole 40b ... cooling Medium discharge communication hole 42 ... Oxidant gas flow path 44 ... Fuel gas flow path 46 ... Cooling medium flow path 48, 50, 124 ... Seal member 52 ... Solid polymer electrolyte membrane 54 ... Cathode electrode 56 ... Anode electrodes 66a, 66b ... Recessed accommodating portions 70a, 70b, 102a, 102b, 104, 106 ... heat insulating members 72a, 7 b, 74a, 74b, 84a, 84b, 86a, 86b, 120a, 120b, 122a, 122b ... recess 88a, 88b, 90a, 90b ... inclined surfaces 116a, 116b, 118a, 118b ... opening

Claims (4)

A power source cell having an electrolyte / electrode structure in which electrodes are arranged on both sides of the electrolyte and a separator is laminated, and a terminal plate, an insulator, and an end plate are arranged on both sides of the laminate in the laminating direction. And at least a reaction gas that is a fuel gas or an oxidant gas is allowed to flow along the electrode surface, and communicates with an inlet side of the reaction gas channel, and the reaction gas is disposed in the stacking direction. A fuel cell stack provided with a reaction gas supply communication hole that circulates in the reaction gas, and a reaction gas discharge communication hole that communicates with the outlet side of the reaction gas flow path and circulates the reaction gas in the stacking direction,
One end plate is formed with a reaction gas inlet communicating with the reaction gas supply communication hole and a reaction gas outlet communicating with the reaction gas discharge communication hole,
The fuel cell stack, wherein the insulator adjacent to the other end plate side has at least a recess communicating with the reaction gas supply communication hole.   2. The fuel cell stack according to claim 1, wherein an opening cross-sectional shape of the recess is set to be at least the same shape as an opening cross-sectional shape of the reaction gas supply communication hole.   3. The fuel cell stack according to claim 1, wherein an inclined surface that is inclined downward toward at least a bottom surface of the reaction gas supply communication hole is formed on a bottom surface in the gravitational direction of the concave portion. stack. The fuel cell stack according to any one of claims 1 to 3, wherein the insulator is provided with a concave accommodating portion on a surface facing the stacked body,
The fuel cell stack, wherein the concave accommodating portion accommodates a heat insulating member and the terminal plate.

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