JP6549864B2 - Fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell stack including a power generation cell having an electrolyte membrane-electrode assembly in which electrodes are disposed on both sides of an electrolyte membrane, and a separator, and a stack in which a plurality of power generation cells are stacked.

  For example, in a polymer electrolyte fuel cell, an electrolyte membrane-electrode assembly (MEA) in which an anode is disposed on one side of an electrolyte membrane comprising a polymer ion exchange membrane and a cathode is disposed on the other side. Is equipped. The electrolyte membrane electrode assembly constitutes a power generation cell by being sandwiched by a separator (bipolar plate). For example, a fuel cell is incorporated into a fuel cell vehicle (fuel cell electric vehicle or the like) as a vehicle fuel cell stack, for example, by stacking a predetermined number of power generation cells.

  In fuel cell stacks, there are power generation cells in which a temperature drop is more likely to occur than in other power generation cells due to heat dissipation to the outside. For example, a power generation cell (hereinafter also referred to as an end power generation cell) disposed at the end in the stacking direction has a large heat dissipation from, for example, a terminal plate for power extraction (collector plate) or an end plate. The temperature drop is remarkable.

  Therefore, for the purpose of reliably preventing the temperature decrease of the end power generation cell with a simple configuration, for example, a fuel cell stack disclosed in Patent Document 1 has been proposed. In the fuel cell stack, a recess is formed in the insulating member, the heat insulating member and the terminal plate are accommodated in the recess, and the heat insulating member is stacked between the terminal plate and the laminate. It is characterized by

Patent No. 5608713 gazette

  The present invention has been made in connection with this type of technology, and can suppress heat radiation from the end in the stacking direction of the laminate as much as possible, and reliably maintain good power generation performance. It aims to provide a possible fuel cell stack.

  A fuel cell stack according to the present invention includes a power generation cell having an electrolyte membrane / electrode assembly in which electrodes are disposed on both sides of an electrolyte membrane, and a separator. A terminal plate, an insulator, and an end plate are disposed outwardly at both ends in the stacking direction of the stack in which the plurality of power generation cells are stacked.

A heat insulating member is interposed between one end of the laminate in the stacking direction and the terminal plate, and the heat insulating member includes a porous carbon plate in contact with the terminal plate. A first uneven portion is formed on a plate surface facing the porous carbon plate of the terminal plate, while a plate surface facing the terminal plate of the porous carbon plate is engaged with the first uneven portion. A second uneven portion is formed. The first uneven portion and the second uneven portion are in contact with at least one of the recessed portion bottom surface and the other protruding portion top surface to form a contact surface, and both side surfaces of the protruding portion forming the first uneven portion. And both side surfaces of the concave portion forming the second uneven portion are separated from each other, and both side surfaces of the concave portion forming the first uneven portion and both side surfaces of the convex portion forming the second uneven portion are separated from each other It forms an air layer Te.

  In the fuel cell stack, preferably, the insulator is provided with a recess opened toward the stack, and at least the porous carbon plate and the terminal plate are accommodated in the recess.

  According to the present invention, the first uneven portion formed on the plate surface of the terminal plate and the second uneven portion formed on the plate surface of the porous carbon plate mesh with each other to form a contact surface. There is. Therefore, since the contact area of the terminal plate and porous carbon plate resulting from heat conduction is favorably reduced, it is possible to suppress heat radiation from the end portion power generation cell to the outside. As a result, generation failure of the fuel cell stack can be prevented, good power generation performance can be secured, and durability can be improved.

FIG. 1 is a perspective view of a fuel cell stack according to a first embodiment of the present invention. It is a partial disassembled schematic perspective view of the said fuel cell stack. FIG. 3 is a cross-sectional view of the fuel cell stack taken along line III-III in FIG. FIG. 6 is an exploded perspective view of a power generation cell of the fuel cell stack. FIG. 5 is a cross-sectional view of the fuel cell stack taken along line V-V in FIG. It is partial cross section explanatory drawing of the insulator side of the fuel cell stack which concerns on the 2nd Embodiment of this invention.

  As shown in FIGS. 1 and 2, in the fuel cell stack 10 according to the first embodiment of the present invention, a plurality of power generation cells 12 are stacked in the horizontal direction (arrow A direction) or the gravity direction (arrow C direction). The stack 14 is provided. Although not shown, the fuel cell stack 10 is mounted on a fuel cell vehicle such as a fuel cell electric car.

  A terminal plate 16a, an insulator (insulation plate) 18a and an end plate 20a are sequentially disposed outward at one end in the stacking direction (arrow A direction) of the stacked body 14 (see FIG. 2). A terminal plate 16b, an insulator (insulation plate) 18b, and an end plate 20b are sequentially disposed outward at the other end in the stacking direction of the stacked body 14. The terminal plates 16a, 16b are made of a material having electrical conductivity, for example, a metal such as copper, aluminum or stainless steel.

  As shown in FIG. 1, the end plates 20 a and 20 b have a horizontally long (or vertically long) rectangular shape, and connecting bars 24 are disposed between the sides. 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 clamping load in the stacking direction (arrow A direction) to the plurality of stacked power generation cells 12. The fuel cell stack 10 may be configured to include a housing having the end plates 20a and 20b as end plates, and to accommodate the stack 14 in the housing.

  In the power generation cell 12, as shown in FIGS. 3 and 4, the resin frame attached membrane electrode assembly 28 is sandwiched between the first separator 30 and the second separator 32. The first separator 30 and the second separator 32 are formed, for example, by press-forming a steel plate, a stainless steel plate, an aluminum plate, a plated steel plate, or a thin metal plate whose surface is treated for corrosion prevention in a corrugated manner. . For example, a carbon separator may be used as the first separator 30 and the second separator 32 instead of the metal separator.

  At one end edge in the direction of arrow B (horizontal direction in FIG. 4) which is the long side direction of the power generation cell 12, the oxidant gas inlet communication hole 34a and the cooling medium communicate with each other in the direction of arrow A (stacking direction). An inlet communication hole 36a and a fuel gas outlet communication hole 38b are provided. The oxidant gas inlet communication hole 34a, the cooling medium inlet communication hole 36a, and the fuel gas outlet communication hole 38b are arranged in the direction of the arrow C, and the oxidant gas inlet communication hole 34a is an oxidant gas such as oxygen. Supply the contained gas. The cooling medium inlet communication hole 36a supplies a cooling medium, and the fuel gas outlet communication hole 38b discharges a fuel gas, for example, a hydrogen-containing gas.

  The fuel gas inlet communication hole 38a, the cooling medium outlet communication hole 36b, and the oxidant gas outlet communication hole 34b communicate with each other in the arrow A direction at the other end edge of the power generation cell 12 in the arrow B direction. Are arranged in The fuel gas inlet manifold 38a supplies the fuel gas, the cooling medium outlet manifold 36b discharges the cooling medium, and the oxidant gas outlet manifold 34b discharges the oxidant gas.

  For example, a fuel gas channel 40 extending in the arrow B direction is formed on the surface 30 a of the first separator 30 facing the resin frame attached electrolyte membrane-electrode assembly 28. The fuel gas passage 40 communicates with the fuel gas inlet passage 38a via the inlet passage 41a, and communicates with the fuel gas outlet passage 38b via the outlet passage 41b. The inlet passage portion 41a has an island-like portion integrally formed by a first seal member 46 described later, and a fuel gas inlet communication passage is formed between the island-like portions. The outlet passage portion 41b has an island-like portion integrally formed by the first seal member 46 similarly to the inlet passage portion 41a, and a fuel gas outlet communication passage is formed between the island-like portions.

  For example, an oxidant gas channel 42 extending in the direction of arrow B is provided on the surface 32 a of the second separator 32 facing the resin-framed membrane electrode assembly 28. The oxidant gas flow channel 42 communicates with the oxidant gas inlet communication hole 34a via the inlet passage 43a, and communicates with the oxidant gas outlet communication hole 34b via the outlet passage 43b. The inlet passage portion 43a has an island-like portion integrally formed by a second seal member 48 described later, and an oxidant gas inlet communication passage is formed between the island-like portions. The outlet passage portion 43b has an island-like portion integrally formed by the second seal member 48 similarly to the inlet passage portion 43a, and an oxidant gas outlet communication passage is formed between the island-like portions.

  A coolant flow path 44 communicating with the coolant inlet communication hole 36 a and the coolant outlet communication hole 36 b is formed between the surface 30 b of the first separator 30 and the surface 32 b of the second separator 32 which are adjacent to each other. . The cooling medium flow channel 44 is formed by overlapping the back surface shape of the first separator 30 in which the fuel gas flow channel 40 is formed and the back surface shape of the second separator 32 in which the oxidizing gas flow channel 42 is formed.

  The first seal member 46 is integrated with the surfaces 30 a and 30 b of the first separator 30 around the outer peripheral end of the first separator 30. The second seal member 48 is integrated with the surfaces 32 a and 32 b of the second separator 32 around the outer peripheral end of the second separator 32.

  As shown in FIG. 3, the first seal member 46 has a flat seal 46f provided across the surfaces 30a, 30b and extending with a uniform thickness. In the flat seal 46f, a first convex seal 46a that abuts on a resin frame member 56 (described later) constituting the resin frame attached membrane electrode assembly 28 is integrally formed on the surface 30a side. In the flat seal 46f, a second convex seal 46b and a third convex seal 46c, which are double seals abutting on the second seal member 48 of the adjacent second separator 32 on the surface 30b side, are integrally molded. .

  The second seal member 48 has a flat seal 48f provided across the surfaces 32a, 32b and extending with a uniform thickness. The flat seal 48f is integrally formed with a fourth convex seal 48a that protrudes outward of the resin-framed membrane electrode assembly 28a and abuts against the first seal member 46 on the surface 32a side. In place of the fourth convex seal 48a, a convex seal (not shown) may be provided on the first seal member 46.

  For the first seal member 46 and the second seal member 48, for example, sealing materials such as EPDM, NBR, fluororubber, silicone rubber, fluorosilicone rubber, butyl rubber, natural rubber, styrene rubber, chloroprene or acrylic rubber, cushion material Alternatively, an elastic seal member such as a packing material is used.

  The resin frame attached electrolyte membrane / electrode assembly 28 includes an electrolyte membrane / electrode assembly 28 a which is a step MEA. The electrolyte membrane / electrode assembly 28 a includes, for example, a solid polymer electrolyte membrane (cation exchange membrane) 50 in which a thin film of perfluorosulfonic acid is impregnated with water, and an anode electrode 52 sandwiching the solid polymer electrolyte membrane 50. And a cathode electrode 54.

  The solid polymer electrolyte membrane 50 may use an HC (hydrocarbon) -based electrolyte in addition to a fluorine-based electrolyte. In addition, it may replace with the resin frame attached electrolyte membrane and electrode structure 28, and may use the electrolyte membrane and electrode structure (MEA) which do not provide the resin frame member 56 mentioned later.

  The cathode electrode 54 has a smaller planar size (outer dimension) than the solid polymer electrolyte membrane 50 and the anode electrode 52. Note that, instead of the above configuration, the anode electrode 52 may be configured to have a smaller planar size than the solid polymer electrolyte membrane 50 and the cathode electrode 54. In addition, the anode electrode 52, the cathode electrode 54, and the solid polymer electrolyte membrane 50 may be set to the same planar size.

  The anode electrode 52 is provided with a first electrode catalyst layer 52 a joined to one surface 50 a of the solid polymer electrolyte membrane 50 and a first gas diffusion layer 52 b stacked on the first electrode catalyst layer 52 a. The first electrode catalyst layer 52 a and the first gas diffusion layer 52 b have the same outer dimensions and are set to the same (or less than the same) outer dimensions as the solid polymer electrolyte membrane 50.

  The cathode electrode 54 is provided with a second electrode catalyst layer 54 a joined to the surface 50 b of the solid polymer electrolyte membrane 50 and a second gas diffusion layer 54 b stacked on the second electrode catalyst layer 54 a. The second electrode catalyst layer 54 a and the second gas diffusion layer 54 b have the same (or different) outer dimensions, and are set to an outer dimension smaller than the outer dimension of the solid polymer electrolyte membrane 50.

  The first electrode catalyst layer 52a is formed, for example, by uniformly applying porous carbon particles having a platinum alloy supported on the surface on the surface of the first gas diffusion layer 52b. The second electrode catalyst layer 54a is formed, for example, by uniformly applying porous carbon particles having a platinum alloy supported on the surface on the surface of the second gas diffusion layer 54b. The first gas diffusion layer 52 b and the second gas diffusion layer 54 b are made of carbon paper, carbon cloth or the like. The first electrode catalyst layer 52 a and the second electrode catalyst layer 54 a are formed on both surfaces 50 a and 50 b of the solid polymer electrolyte membrane 50.

  The resin-framed electrolyte membrane / electrode assembly 28 includes a frame-shaped resin frame member 56 which goes around the periphery of the solid polymer electrolyte membrane 50 and is bonded to the anode electrode 52 and the cathode electrode 54. The resin frame member 56 is made of, for example, PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyether sulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), It is composed of silicone resin, fluorocarbon resin, or m-PPE (modified polyphenylene ether resin). Alternatively, the resin frame member 56 may be made of PET (polyethylene terephthalate), PBT (polybutylene terephthalate) or modified polyolefin.

  The resin frame member 56 has a thin-walled outer swelling portion abutted with the thin-walled inner swelling portion 56a to which the outer peripheral edge portion of the solid polymer electrolyte membrane 50 is joined and the first convex-shaped seal 46a And an outlet 56b.

  As shown in FIG. 3, the power generation cells 12 are disposed as end power generation cells 12A and 12B at both ends in the stacking direction of the stacked body 14. The end power generation cells 12A are disposed on the terminal plate 16a side, while the end power generation cells 12B are disposed on the terminal plate 16b side.

  As shown in FIG. 2, terminal portions 64a and 64b extending outward in the stacking direction are provided substantially at the centers of the plate surfaces 16a1 and 16b1 of the terminal plates 16a and 16b. The terminal portions 64a and 64b are inserted into the insulating cylindrical members 66a and 66b and penetrate the hole portions 68a and 68b of the insulators 18a and 18b and the hole portions 70a and 70b of the end plates 20a and 20b, respectively. Project outside of

  First uneven portions 72a and 72b are formed on the other plate surfaces (plate surfaces facing the first porous carbon plates 80a and 80b) 16a2 and 16b2 of the terminal plates 16a and 16b. As shown in FIGS. 2 and 5, in the first uneven portion 72a, the concave portions and the convex portions extend in the arrow B direction and are alternately provided in the arrow C direction. The first uneven portion 72a has a first recess bottom surface 72ab provided on the inner surface of the recess and a first protrusion top surface 72as provided on the tip end surface of the protrusion.

  As shown in FIG. 2, in the first uneven portion 72 b, the concave portion and the convex portion extend in the arrow B direction and are alternately provided in the arrow C direction. The first uneven portion 72b has a first recess bottom surface 72bb provided on the inner surface of the recess and a first protrusion top surface 72bs provided on the tip end surface of the protrusion.

  The insulators 18a and 18b are formed of an insulating material such as polycarbonate (PC) or phenol resin. Recesses 74a and 74b opened toward the laminated body 14 are formed at central portions of the insulators 18a and 18b, and the recesses 74a and 74b communicate with the holes 68a and 68b.

  As shown in FIGS. 2 and 3, the terminal plate 16a and the heat insulating member 78a are accommodated in the recess 74a, while the terminal plate 16b and the heat insulating member 78b are accommodated in the recess 74b. In addition, you may provide only any one of the heat insulation member 78a or the heat insulation member 78b.

  The heat insulating member 78a includes a first porous carbon plate 80a having a rectangular shape (rectangular or square), a metal plate 82a having a corrugated plate shape, and a second porous carbon plate 84a. The heat insulating member 78a may include at least the first porous carbon plate 80a. The first porous carbon plate 80 a is made of a material having electrical conductivity.

  As shown in FIGS. 2 and 5, a second uneven portion 86 a is formed on the plate surface 80 a 1 facing the terminal plate 16 a of the first porous carbon plate 80 a. In the second uneven portion 86a, the concave portion and the convex portion extend in the arrow B direction and are alternately provided in the arrow C direction. The second uneven portion 86a has a second recess bottom surface 86ab provided on the inner surface of the recess and a second protrusion top surface 86as provided on the tip end surface of the protrusion.

  As shown in FIG. 5, the first uneven portion 72a of the terminal plate 16a and the second uneven portion 86a of the first porous carbon plate 80a are engaged with each other to form a contact surface. The convex portion of the first uneven portion 72a is disposed in the concave portion of the second uneven portion 86a, while the convex portion of the first porous carbon plate 80a is disposed in the concave portion of the first uneven portion 72a.

  The width dimension h1 of the convex portion of the first uneven portion 72a is set to be smaller than the width dimension h2 of the concave portion of the second uneven portion 86a (h1 <h2). The width dimension h3 of the protrusion of the second uneven portion 86a is set to be smaller than the width dimension h4 of the recess of the first uneven portion 72a (h3 <h4). The first convex portion top surface 72as of the first uneven portion 72a abuts on the second recessed portion bottom surface 86ab of the second uneven portion 86a. An air layer 88 is formed between the terminal plate 16a and the first porous carbon plate 80a, and functions as a heat insulating layer.

  The top surface 72as of the first convex portion overlaps the convex portion protruding toward the first porous carbon plate 80a of the metal plate 82a as viewed in the stacking direction. The second convex top surface 86as of the second uneven portion 86a is separated from the first concave bottom surface 72ab of the first uneven portion 72a by a distance t.

  The plate surface 80a2 (surface opposite to the plate surface 80a1) of the first porous carbon plate 80a forms a flat surface. The second porous carbon plate 84 a has a flat shape on both sides.

  The heat insulating member 78b is configured in the same manner as the above-described heat insulating member 78a, and the same reference numerals are given the same reference numerals and b instead of a, and the detailed description thereof will be omitted.

  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 inlet manifold 34a of the end plate 20a. Fuel gas such as hydrogen-containing gas is supplied to the fuel gas inlet passage 38a of the end plate 20a. A coolant such as pure water, ethylene glycol, or oil is supplied to the coolant inlet communication hole 36a of the end plate 20a.

  The oxidant gas is introduced from the oxidant gas inlet manifold 34 a into the oxidant gas flow path 42 of the second separator 32 as shown in FIG. 4. The oxidant gas moves in the direction of arrow B along the oxidant gas flow channel 42, and is supplied to the cathode electrode 54 of the membrane electrode assembly 28a.

  On the other hand, the fuel gas is introduced into the fuel gas flow path 40 of the first separator 30 from the fuel gas inlet communication hole 38 a. The fuel gas moves in the direction of arrow B along the fuel gas flow path 40 and is supplied to the anode 52 of the membrane electrode assembly 28a.

  Therefore, in each of the membrane electrode assembly 28a, the oxidant gas supplied to the cathode 54 and the fuel gas supplied to the anode 52 are contained in the second electrode catalyst layer 54a and the first electrode catalyst layer 52a. The electricity is consumed by the electrochemical reaction to generate electricity.

  Then, the oxidant gas supplied to and consumed by the cathode electrode 54 is discharged in the direction of arrow A along the oxidant gas outlet passage 34b. The fuel gas supplied and consumed to the anode electrode 52 is discharged in the direction of arrow A along the fuel gas outlet passage 38b.

  Further, the cooling medium supplied to the cooling medium inlet communication hole 36 a is introduced into the cooling medium channel 44 between the first separator 30 and the second separator 32, and then flows in the arrow B direction. The cooling medium is discharged from the cooling medium outlet communication hole 36b after cooling the membrane electrode assembly 28a.

  In this case, in the first embodiment, as shown in FIG. 5, while the first uneven portion 72a is formed on the plate surface 16a2 of the terminal plate 16a, the second uneven portion 72a is formed on the plate surface 80a1 of the first porous carbon plate 80a. An uneven portion 86a is formed. The first uneven portion 72a and the second uneven portion 86a mesh with each other to form a contact surface.

  Therefore, the contact area between the terminal plate 16a and the first porous carbon plate 80a due to heat conduction is favorably reduced, so that it is possible to suppress heat radiation from the end power generation cell 12A to the outside (see FIG. 3). ). In addition, the first convex top surface 72as of the first concavo-convex portion 72a is in contact with the second concave bottom surface 86ab of the second concavo-convex portion 86a, so that the energization is surely performed.

  As a result, generation failure of the fuel cell stack 10 can be prevented, good power generation performance can be secured, and durability can be improved. The same effect can be obtained on the end power generation cell 12B side.

  Further, in the first embodiment, a cell unit in which a resin-framed membrane electrode assembly is sandwiched between two separators is configured, and a cooling medium flow path is formed between the cell units. Although a cooling structure is adopted, it is not limited to this.

  For example, a cell unit comprising three or more separators and two or more resin-framed electrolyte membrane / electrode structures, wherein the separators and the resin-framed electrolyte membrane / electrode structures are alternately laminated, A so-called thinned cooling structure may be employed in which a cooling medium flow channel is formed between cell units.

  Furthermore, as shown in FIG. 2, the first uneven portion 72a, 72b and the second uneven portion 86a, 86b extend in the horizontal direction (arrow B direction) (longitudinal direction) and in the vertical direction (arrow C direction). But they are not limited to this. For example, the uneven portions may extend in the vertical direction (arrow C direction) and be alternately provided in the horizontal direction (arrow B direction).

  Furthermore, each uneven portion may have a (cross-shaped) concave portion extending in the horizontal direction and the vertical direction, and a (cross-shaped) convex portion extending in the horizontal direction and the vertical direction. In addition, each uneven portion may circulate in a ring shape or may be inclined, and various shapes can be adopted. The second embodiment described below can be configured in the same manner.

  FIG. 6 is a partial cross-sectional view of the fuel cell stack 90 according to a second embodiment of the present invention on the side of the insulator 18a. The same components as those of the fuel cell stack 10 according to the first embodiment are designated by the same reference numerals, and the detailed description thereof is omitted.

  The terminal plate 16a and the heat insulating member 92a are accommodated in the recess 74a of the insulator 18a. The heat insulating member 92a includes a first porous carbon plate 94a, a metal plate 82a and a second porous carbon plate 84a each having a rectangular shape (rectangular or square).

  A second uneven portion 96a is formed on the plate surface 94a1 opposite to the terminal plate 16a of the first porous carbon plate 94a. In the second uneven portion 96 a, the concave portion and the convex portion extend in the arrow B direction and are alternately provided in the arrow C direction. The second uneven portion 96a has a second concave bottom surface 96ab and a second convex top surface 96as. The first uneven portion 72a of the terminal plate 16a and the second uneven portion 96a of the first porous carbon plate 94a engage with each other to form a contact surface.

  The convex portion of the first uneven portion 72a is disposed in the concave portion of the second uneven portion 96a, while the convex portion of the first porous carbon plate 94a is disposed in the concave portion of the first uneven portion 72a. The second convex top surface 96as of the second uneven portion 96a abuts on the first concave bottom surface 72ab of the first uneven portion 72a.

  In the second embodiment configured as described above, the contact area between the terminal plate 16a and the first porous carbon plate 94a due to heat conduction is favorably reduced. Heat dissipation can be suppressed. Moreover, the first convex top surface 72as of the first uneven portion 72a abuts on the second concave bottom surface 96ab of the second uneven portion 96a, and the second convex upper surface 96as of the second uneven portion 96a is the first It is in contact with the first concave bottom surface 72ab of the uneven portion 72a. As a result, the same effects as those of the first embodiment described above can be obtained, such as conduction of electricity reliably.

DESCRIPTION OF SYMBOLS 10, 90 ... Fuel cell stack 12 ... Power generation cell 12A, 12B ... End part power generation cell 14 ... Laminated body 16a, 16b ... Terminal plate 18a, 18b ... Insulator 20a, 20b ... End plate 28 ... Electrolyte membrane-electrode structure with resin frame Body 28a: Electrolyte membrane electrode assembly 30, 32: Separator 34a: Oxidant gas inlet communication hole 34b: Oxidant gas outlet communication hole 36a: Cooling medium inlet communication hole 36b: Cooling medium outlet communication hole 38a: Fuel gas inlet communication Hole 38b Fuel gas outlet communication hole 40 Fuel gas flow path 42 Oxidant gas flow path 44 Cooling medium flow path 46, 48 Seal member 50 Solid polymer electrolyte membrane 52 Anode electrode 54 Cathode electrode 56 Resin frame members 72a, 72b, 86a, 86b, 96a ... concavo-convex portions 72ab, 72bb, 86ab, 96a ... recess bottom surface 72as, 72bs, 86as, 96as ... protrusion top surface 74a, 74b ... recess 78a, 78b, 92a ... heat insulating member 80a, 84a, 94a ... porous carbon plate 82a ... metal plate

Claims (2)

A power generating cell having an electrolyte membrane / electrode assembly in which electrodes are disposed on both sides of an electrolyte membrane, and a separator, and facing outward at both ends in the stacking direction of the stacked body in which a plurality of power generating cells are stacked. A fuel cell stack in which the terminal plate, the insulator and the end plate are disposed,
A heat insulating member is interposed between at least one end of the stack in the stacking direction and the terminal plate.
The heat insulating member comprises a porous carbon plate in contact with the terminal plate,
While the first uneven portion is formed on the plate surface of the terminal plate facing the porous carbon plate,
On the plate surface of the porous carbon plate facing the terminal plate, a second uneven portion engaging with the first uneven portion is formed,
The first indented portion and the second indented portion abut on at least one of the concave bottom surface and the other convex top surface to form a contact surface ,
Both side surfaces of the convex portion forming the first uneven portion and both side surfaces of the concave portion forming the second uneven portion are separated from each other and both side surfaces of the concave portion forming the first uneven portion and the second uneven portion What is claimed is: 1. A fuel cell stack, comprising: an air layer formed by mutually separating side surfaces of a convex portion forming a gap ;   2. The fuel cell stack according to claim 1, wherein the insulator is provided with a recess opened toward the laminate, and at least the porous carbon plate and the terminal plate are accommodated in the recess. Fuel cell stack.

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