Power generation cells and fuel cell stacks

Abstract

To provide a fuel cell separator capable of increasing the degree of freedom in layout of a reaction flow path formed in the separator.SOLUTION: A power generation cell 10 of a fuel cell stack 12 includes a resin-framed membrane electrode assembly 22, a first separator 24, and a second separator 26. A second gas flow path 72 for allowing a reactant gas to flow along an electrode surface of the membrane electrode assembly 32 is formed on the second separator, a first connection flow path 78 in communication with an oxidant gas supply communicating hole 14a is formed on the first separator, and a first through-hole 80 communicating the second gas flow path and the first connection flow path to each other is formed in a resin frame member 34.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a power generating cell and a fuel cell stack. [Background technology]

[0002] In recent years, research and development into fuel cells has been conducted to contribute to energy efficiency in order to ensure that more people have access to affordable, reliable, sustainable and advanced energy.

[0003] Patent Document 1 discloses a power generating cell of a fuel cell stack. This power generating cell includes a resin-framed MEA, a first separator laminated on one side of the resin-framed MEA, and a second separator laminated on the other side of the resin-framed MEA. The first and second separators have an oxidant gas supply passage, an oxidant gas discharge passage, a fuel gas supply passage, and a fuel gas discharge passage formed therethrough in the stacking direction.

[0004] The first separator has a first flow path formed therein for flowing oxidant gas along the cathode electrode of the resin-framed MEA. The first flow path communicates with the oxidant gas supply passage and the oxidant gas discharge passage formed in the first separator. The second separator has a second flow path formed therein for flowing fuel gas along the anode electrode of the resin-framed MEA. The second flow path communicates with the fuel gas supply passage and the fuel gas discharge passage formed in the second separator. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2010-287452 A Summary of the Invention [Problem to be solved by the invention]

[0006] In the above-mentioned power generating cell, it is not possible to increase the degree of freedom in the layout of the flow paths formed in the separator.

[0007] The present invention aims to solve the above-mentioned problems. [Means for solving the problem]

[0008] One aspect of the present invention includes a resin-framed membrane electrode assembly having a membrane electrode assembly and a resin frame provided on an outer periphery of the membrane electrode assembly, a first separator laminated on one surface of the resin-framed membrane electrode assembly, and a second separator laminated on the other surface of the resin-framed membrane electrode assembly, wherein each of the first separator and the second separator has a first separator that penetrates in the stacking direction and 1. Reactant gas flows 1. Reactive Gas supply Communication hole a first reactant gas discharge passage, and second reactant gas supply passages and second reactant gas discharge passages penetrating in the stacking direction through which a second reactant gas flows; A power generating cell formed with the first separator is formed with a first reactant gas flow path for circulating the first reactant gas along one electrode surface of the membrane electrode assembly, a flow path connecting the first reactant gas supply passage and the first reactant gas flow path, and a flow path connecting the first reactant gas discharge passage and the first reactant gas flow path, The second separator is The other Along the electrode surface Second Flowing reactive gas Second A reactant gas flow path is formed in the first separator. Second Reactive Gas supply Connect to the communication hole No. 1 Connection Channel a second connection passage communicating with the second reactant gas discharge passage; is formed in the resin frame portion. Second The reaction gas flow path and the No. 1 The connecting flow path is connected to each other. No. 1 Through hole a second through hole that connects the second reaction gas flow path and the second connection flow path to each other; is formed in the power generating cell.

[0009] Another aspect of the present invention is a fuel cell stack in which a plurality of the above-described power generating cells are stacked. Effect of the Invention

[0010] According to the present invention, 2 This increases the degree of freedom in the layout of the flow paths formed in the separator. [Brief description of the drawings]

[0011] [Figure 1] FIG. 1 is an exploded perspective view, with some parts omitted, of a fuel cell stack according to the present invention. [Diagram 2] FIG. 2 is a plan view of the first separator. [Diagram 3] FIG. 3 is a plan view of the second separator. [Figure 4] FIG. 4 is a partially enlarged plan view of the oxidant gas supply passage and its periphery of the power generating cell. [Diagram 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a partially enlarged plan view of the oxidant gas discharge passage and its periphery of the power generating cell. [Figure 7] FIG. 7 is a cross-sectional view taken along line VII-VII in FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0012] A power generating cell 10 and a fuel cell stack 12 according to one embodiment of the present invention will be described below with reference to the drawings. As shown in FIG. 1, the fuel cell stack 12 according to this embodiment is formed by stacking a plurality of power generating cells 10 in their thickness direction (the direction of the arrow A). The fuel cell stack 12 is mounted, for example, in a fuel cell electric vehicle (not shown) as an on-board fuel cell stack. The fuel cell stack 12 may be installed on the ground. The stacking direction of the plurality of power generating cells 10 may be either the horizontal direction or the direction of gravity.

[0013] The power generating cell 10 is formed in a horizontally long rectangular shape. The shape of the power generating cell 10 is not particularly limited, and may be formed in, for example, a vertically long rectangular shape or a square shape. The power generating cell 10 generates power by an electrochemical reaction between an oxidant gas, which is one reactant gas, and a fuel gas, which is the other reactant gas. The oxidant gas is, for example, an oxygen-containing gas. The fuel gas is, for example, a hydrogen-containing gas. A cooling medium for cooling the power generating cell 10 flows through the power generating cell 10. The cooling medium is, for example, pure water, ethylene glycol, oil, or the like.

[0014] Each power generation cell 10 has an oxidant gas supply passage 14a, an oxidant gas discharge passage 14b, a fuel gas supply passage 16a, a fuel gas discharge passage 16b, a cooling medium supply passage 18a, and a cooling medium discharge passage 18b formed therethrough in the stacking direction (the direction of arrow A).

[0015] The oxidant gas supply passage 14a supplies oxidant gas to the plurality of power generating cells 10. The oxidant gas discharge passage 14b discharges the oxidant gas discharged from the plurality of power generating cells 10. The fuel gas supply passage 16a supplies fuel gas to the plurality of power generating cells 10. The fuel gas discharge passage 16b discharges the fuel gas discharged from the plurality of power generating cells 10. The coolant supply passage 18a supplies a coolant to the plurality of power generating cells 10. The coolant discharge passage 18b discharges the fuel gas discharged from the plurality of power generating cells 10. cooling medium is discharged.

[0016] The oxidant gas supply passage 14a, the coolant discharge passage 18b, and the fuel gas discharge passage 16b are provided at one edge portion in the long side direction (edge ​​portion in the direction of arrow B1) of the power generating cell 10. The oxidant gas supply passage 14a, the coolant discharge passage 18b, and the fuel gas discharge passage 16b are aligned in the short side direction of the power generating cell 10 (the direction of arrow C).

[0017] The oxygen-containing gas flows through the oxygen-containing gas supply passage 14a in the direction of the arrow A2. The coolant flows through the coolant discharge passage 18b in the direction of the arrow A1. The fuel gas flows through the fuel gas discharge passage 16b in the direction of the arrow A1.

[0018] A fuel gas supply passage 16a, a coolant supply passage 18a, and an oxygen-containing gas discharge passage 14b are provided at the other long edge portion (the edge portion in the direction of arrow B2) of the power generating cell 10. The fuel gas supply passage 16a, the coolant supply passage 18a, and the oxygen-containing gas discharge passage 14b are aligned in the direction of arrow C.

[0019] The fuel gas flows through the fuel gas supply passage 16a in the direction of the arrow A2. The cooling medium flows through the cooling medium supply passage 18a in the direction of the arrow A3. 2 The oxidizing gas flows in the direction of the arrow A through the oxidizing gas discharge passage 14b. 1 It flows in a direction.

[0020] The oxidant gas supply passage 14a, the oxidant gas discharge passage 14b, the fuel gas supply passage 16a, and the fuel gas discharge passage 16b are reactant gas passages through which reactant gas (oxidant gas or fuel gas used for power generation) flows. The arrangement, shape, and size of the oxidant gas supply passage 14a, the oxidant gas discharge passage 14b, the fuel gas supply passage 16a, the fuel gas discharge passage 16b, the coolant supply passage 18a, and the coolant discharge passage 18b may be appropriately set according to required specifications.

[0021] The power generating cell 10 includes a resin-framed membrane electrode assembly 22, a first separator 24, and a second separator 26. The first separator 24 is disposed on one surface (the surface in the direction of arrow A1) of the resin-framed membrane electrode assembly 22. The second separator 26 is disposed on the other surface (the surface in the direction of arrow A2) of the resin-framed membrane electrode assembly 22. The first separator 24 and the second separator 26 sandwich the resin-framed membrane electrode assembly 22 from the direction of arrow A. When a plurality of power generating cells 10 are stacked on top of each other, the first separator 24 and the second separator 26 come into contact with each other (see FIGS. 5 and 7).

[0022] The resin-framed membrane electrode assembly 22 has a membrane electrode assembly 32 (MEA: Membrane Electrode Assembly) and a resin frame member 34 (resin frame portion). The membrane electrode assembly 32 includes an electrolyte membrane 36, a first electrode 38, and a second electrode 40. The electrolyte membrane 36 is, for example, a solid polymer electrolyte membrane (cation exchange membrane). The solid polymer electrolyte membrane is, for example, a thin film of perfluorosulfonic acid containing moisture. The electrolyte membrane 36 may be a fluorine-based electrolyte or an HC (hydrocarbon)-based electrolyte. The electrolyte membrane 36 is sandwiched between the first electrode 38 and the second electrode 40.

[0023] The first electrode 38 is an anode electrode provided on one surface (the surface in the direction of arrow A1) of the electrolyte membrane 36. The second electrode 40 is a cathode electrode provided on the other surface (the surface in the direction of arrow A2) of the electrolyte membrane 36. The first separator 24 is disposed so as to face the first electrode 38. The second separator 26 is disposed so as to face the second electrode 40.

[0024] The fuel gas flowing through the fuel gas supply passage 16a is guided between the first separator 24 and the resin framed membrane electrode assembly 22, and thereby supplied to the first electrode 38. The oxidant gas flowing through the oxidant gas supply passage 14a is guided between the second separator 26 and the resin framed membrane electrode assembly 22, and thereby supplied to the second electrode 40. The power generating cell 10 generates power from the fuel gas supplied to the first electrode 38 and the oxidant gas supplied to the second electrode 40.

[0025] The fuel gas that flows between the first separator 24 and the resin-framed membrane electrode assembly 22 is guided to the fuel gas discharge passage 16b. The oxidant gas that flows between the second separator 26 and the resin-framed membrane electrode assembly 22 is guided to the oxidant gas discharge passage 14b. The cooling medium that flows through the cooling medium supply passage 18a flows between the first separator 24 and the second separator 26, and is guided to the cooling medium discharge passage 18b.

[0026] The first electrode 38 has a first electrode catalyst layer and a first gas diffusion layer. The first electrode catalyst layer is bonded to one surface of the electrolyte membrane 36. The first gas diffusion layer is laminated on the first electrode catalyst layer. The first electrode catalyst layer includes, for example, porous carbon particles having a platinum alloy supported on the surface. The porous carbon particles are uniformly applied to the surface of the first gas diffusion layer together with an ion-conductive polymer binder.

[0027] The second electrode 40 has a second electrode catalyst layer and a second gas diffusion layer. The second electrode catalyst layer is bonded to the other surface of the electrolyte membrane 36. The second gas diffusion layer is laminated on the second electrode catalyst layer. The second electrode catalyst layer includes, for example, porous carbon particles having a platinum alloy supported on the surface. The porous carbon particles are uniformly applied to the surface of the second gas diffusion layer together with an ion-conductive polymer binder. Each of the first gas diffusion layer and the second gas diffusion layer is made of carbon paper, carbon cloth, or the like.

[0028] The resin frame member 34 is a frame-shaped sheet that surrounds the outer periphery of the membrane electrode structure 32. The resin frame member 34 has electrical insulation properties. Examples of materials that can be used for the resin frame member 34 include PPS (polyphenylene sulfide), PPA (polyphthalamide), PEN (polyethylene naphthalate), PES (polyethersulfone), LCP (liquid crystal polymer), PVDF (polyvinylidene fluoride), silicone resin, fluororesin, m-PPE (modified polyphenylene ether resin), PET (polyethylene terephthalate), PBT (polybutylene terephthalate), and modified polyolefin.

[0029] The resin frame member 34 of the resin-framed membrane electrode assembly 22 may be formed by making the electrolyte membrane 36 protrude outward beyond the outer periphery of the first electrode 38 and the second electrode 40 .

[0030] As shown in Figs. 1 and 2, the first separator 24 is formed in a plate shape. The first separator 24 is, for example, a thin metal plate such as a steel plate, a stainless steel plate, or an aluminum plate. The first separator 24 may be subjected to anticorrosion treatment. The first separator 24 is formed in a rectangular shape. One end edge portion of the first separator 24 (the end edge portion in the direction of the arrow B1) is provided with an oxidant gas supply passage 14a, a cooling medium discharge passage 18b, and a fuel gas discharge passage 16b. The other end edge portion of the first separator 24 (the end edge portion in the direction of the arrow B2) is provided with a fuel gas supply passage 16a, a cooling medium supply passage 18a, and an oxidant gas discharge passage 14b. The first separator 24 is formed by press-molding a metal plate.

[0031] 2, the first separator 24 has a front surface 42 facing the resin-framed membrane electrode assembly 22, and a back surface 44 facing the second separator 26 of the power generating cell 10 adjacent to the first separator 24. A first gas flow path 46, which is one of the reactant gas flow paths, is formed on the front surface 42 of the first separator 24. The first gas flow path 46 is a fuel gas flow path that flows the fuel gas along the first electrode 38.

[0032] The first gas flow passage 46 includes a plurality of first flow passage convex portions 48 and a plurality of first flow passage grooves 50. The first flow passage convex portions 48 and the first flow passage grooves 50 are alternately provided in the direction of the arrow C. Each of the first flow passage convex portions 48 and the first flow passage grooves 50 extends linearly in the direction of the arrow B. Each of the first flow passage convex portions 48 and the first flow passage grooves 50 may extend in a wavy manner in the direction of the arrow B. The first gas flow passage 46 communicates with the fuel gas supply passage 16a and the fuel gas discharge passage 16b.

[0033] An inlet buffer 52a is provided between the fuel gas supply passage 16a and the first gas flow path 46. The inlet buffer 52a includes a plurality of embossed portions spaced apart in the direction of arrow C. The embossed portions bulge from the rear surface 44 of the first separator 24 toward the front surface 42 (in the direction of arrow A2 in FIG. 1).

[0034] An outlet buffer 52b is provided between the fuel gas discharge passage 16b and the first gas flow passage 46. The outlet buffer 52b includes a plurality of embossed portions spaced apart in the direction of arrow C. The embossed portions protrude from the rear surface 44 of the first separator 24 toward the front surface 42 (in the direction of arrow A2 in FIG. 1).

[0035] 2, a first adhesive layer 54 for bonding the first separator 24 and the resin frame member 34 to each other is provided on the surface 42 of the first separator 24. The first adhesive layer 54 is composed of an adhesive 56 that blocks the flow of the oxidizer gas, the fuel gas, and the cooling medium.

[0036] The first adhesive layer 54 is formed, for example, by applying a liquid adhesive 56 to the surface 42 of the first separator 24. The first adhesive layer 54 may be formed by applying the liquid adhesive 56 to one surface (the surface facing the first separator 24) of the resin frame member 34 (see FIG. 1). The first adhesive layer 54 may be formed by sandwiching an adhesive sheet of a predetermined shape made of the adhesive 56 between the first separator 24 and the resin frame member 34.

[0037] The first adhesive layer 54 individually surrounds the oxidant gas supply passage 14a, the oxidant gas discharge passage 14b, the coolant supply passage 18a, and the coolant discharge passage 18b. The first adhesive layer 54 also surrounds a continuous flow path including the fuel gas supply passage 16a, the first gas flow path 46, and the fuel gas discharge passage 16b.

[0038] As shown in Fig. 1, a first coolant flow field 58 is formed on the back surface 44 of the first separator 24. The first coolant flow field 58 has the shape of the back surface of the first gas flow field 46. An inlet buffer 60a is provided between the first coolant flow field 58 and the coolant supply passage 18a. The inlet buffer 60a includes a plurality of bosses arranged at intervals in the direction of arrow C. The bosses bulge from the front surface 42 of the first separator 24 toward the back surface 44 (in the direction of arrow A1 in Fig. 1).

[0039] An outlet buffer 60b is provided between the first coolant flow field 58 and the coolant discharge passage 18b. The outlet buffer 60b includes a plurality of embossed portions arranged at intervals in the direction of arrow C. The embossed portions extend from the front surface 42 of the first separator 24 toward the back surface 44 (arrows in FIG. 1 ). A1 protruding in one direction.

[0040] A seal member 62 is provided on the back surface 44 of the first separator 24 to prevent leakage of the oxidant gas, fuel gas, and cooling medium to the outside. The seal member 62 adheres closely to the back surface 70 of the second separator 26 in a state in which the power generation cells 10 are stacked together and a tightening load is applied to the seal member 62. The seal member 62 is made of an elastic resin material. Specifically, the seal member 62 is made of a rubber material.

[0041] The seal member 62 includes a plurality of communication hole seals 64 and a flow path seal 66. The communication hole seals 64 individually surround the oxidant gas supply passage 14a, the oxidant gas discharge passage 14b, the fuel gas supply passage 16a, and the fuel gas discharge passage 16b. The flow path seal 66 surrounds a continuous flow path including the coolant supply passage 18a, the first coolant flow path 58, and the coolant discharge passage 18b.

[0042] As shown in Figs. 1 and 3, the second separator 26 is formed in a plate shape. The second separator 26 is, for example, a thin metal plate such as a steel plate, a stainless steel plate, or an aluminum plate. The second separator 26 may be subjected to anticorrosion treatment. The second separator 26 is formed in a rectangular shape. At one end edge portion of the second separator 26 (the end edge portion in the direction of the arrow B1), the oxidant gas supply passage 14a, the cooling medium discharge passage 18b, and the fuel gas discharge passage 16b are provided. At the other end edge portion of the second separator 26 (the end edge portion in the direction of the arrow B2), the fuel gas supply passage 16a, the cooling medium supply passage 18a, and the oxidant gas discharge passage 14b are provided. The second separator 26 is formed by press-molding a metal plate.

[0043] As shown in FIG. 3, the second separator 26 has a surface 68 facing the resin-framed membrane electrode assembly 22 and a first separator ... first separator 68 of the adjacent power generating cell 10. 1 Separator 24 The second separator 26 has a back surface 70 facing the second electrode 40. A second gas flow passage 72, which is the other reactant gas flow passage, is formed in the front surface 68 of the second separator 26. The second gas flow passage 72 is arranged along the second electrode 40. Oxidizing agentAn oxidant gas flow path allows gas to flow.

[0044] The second gas flow path 72 includes a plurality of second flow path convex portions 74 and a plurality of second flow path grooves 76. The second flow path convex portions 74 and the second flow path grooves 76 are alternately provided in the direction of arrow C. Each of the second flow path convex portions 74 and the second flow path grooves 76 extends linearly in the direction of arrow B. Alternatively, each of the second flow path convex portions 74 and the second flow path grooves 76 may extend in a wavy manner in the direction of arrow B.

[0045] As shown in Fig. 1, the second gas flow passage 72 communicates with the oxidant gas supply passage 14a via a first connection flow passage 78, a first through-hole 80, and an introduction flow passage 82. As shown in Figs. 1 and 2, the first connection flow passage 78 is provided in the first separator 24. The first connection flow passage 78 is located in the direction of arrow B2 of the oxidant gas supply passage 14a. The first connection flow passage 78 is surrounded by the first adhesive layer 54 (see Fig. 2).

[0046] 2, 4, and 5, the first connection flow passage 78 has a plurality of first tunnels 84. The plurality of first tunnels 84 are arranged at intervals in the direction of arrow C. The first tunnels 84 extend in the direction of arrow B. The first tunnels 84 bulge from the front surface 42 toward the back surface 44 of the first separator 24 (see FIG. 5). A first inner hole 86 through which the oxidant gas flows is formed inside the first tunnel 84.

[0047] 4 and 5, the first tunnel 84 is located in the direction of arrow B2 with respect to the oxidant gas supply passage 14a. A hole seal 64 surrounding the oxidant gas supply passage 14a and a flow passage seal 66 are provided on the outer surface of the first tunnel 84. In the following description, the hole seal 64 surrounding the oxidant gas supply passage 14a will be referred to as the "hole seal 64a."

[0048] One end 84a (end in the direction of arrow B1) of the first tunnel 84 is located inside the communication hole seal portion 64. A first opening 88 that communicates with the first inner hole 86 is formed at one end 84a of the first tunnel 84. The first opening 88 communicates with a first communication space 90 between the oxidant gas supply passage 14a and the communication hole seal portion 64. The other end 84b (end in the direction of arrow B2) of the first tunnel 84 is located inside the flow path seal portion 66.

[0049] 1 and 5, the first through hole 80 is formed in the resin frame member 34. The first through hole 80 is a slit extending in the direction of arrow C. When viewed from the stacking direction of the power generating cells 10, the first through hole 80 overlaps with the other end 84b of the first tunnel 84 (see FIG. 4).

[0050] 1 and 3, the introduction passage 82 is provided in the second separator 26. The introduction passage 82 is located between the oxidant gas supply passage 14a and the second gas passage 72. The introduction passage 82 has a plurality of second tunnels 92.

[0051] As shown in Figs. 3 to 5, the second tunnels 92 are arranged at intervals in the direction of arrow C. The second tunnels 92 extend in the direction of arrow B. As shown in Fig. 5, the second tunnels 92 bulge from the front surface 68 toward the back surface 70 of the second separator 26. A second inner hole 94 through which the oxidant gas flows is formed inside the second tunnel 92. The second inner hole 94 of the second tunnel 92 communicates with the first inner hole 86 of the first tunnel 84 via the first through hole 80.

[0052] 4, when viewed from the stacking direction of the power generating cells 10, one end 92a (end in the direction of arrow B1) of the second tunnel 92 overlaps with the first through hole 80. In other words, when viewed from the stacking direction of the power generating cells 10, the other end 84b of the first tunnel 84 overlaps with one end 92a of the second tunnel 92 and the first through hole 80. A second opening 96 facing the direction of arrow B2 is formed in the other end 92b (end in the direction of arrow B2) of the second tunnel 92 (see FIGS. 4 and 5).

[0053] 3, an inlet buffer 98a is provided between the introduction flow path 82 and the second gas flow path 72. The inlet buffer 98a includes a plurality of embossed portions spaced apart in the direction of arrow C. The embossed portions bulge from the rear surface 70 of the second separator 26 toward the front surface 68 (in the direction of arrow A1 in FIG. 1).

[0054] As shown in Fig. 1, the second gas flow passage 72 communicates with the oxidant gas discharge passage 14b via the second connection flow passage 100, the second through-hole 102, and the outlet flow passage 104. As shown in Figs. 1 and 2, the second connection flow passage 100 is provided in the first separator 24. The second connection flow passage 100 is located in the direction of arrow B1 of the oxidant gas discharge passage 14b. The second connection flow passage 100 is surrounded by the first adhesive layer 54 (see Fig. 2).

[0055] 2, 6, and 7, the second connection flow path 100 has a plurality of third tunnels 106. The plurality of third tunnels 106 are arranged at intervals in the direction of arrow C. The third tunnels 106 extend in the direction of arrow B. The third tunnels 106 bulge from the front surface 42 toward the back surface 44 of the first separator 24 (see FIG. 7). A third inner hole 108 through which the oxidant gas flows is formed inside the third tunnel 106.

[0056] 6 and 7, the third tunnel 106 is located in the direction of arrow B1 with respect to the oxidant gas discharge passage 14b. A communication hole seal portion 64 surrounding the oxidant gas discharge passage 14b and a flow passage seal portion 66 are provided on the outer surface of the third tunnel 106. In the following description, the communication hole seal portion 64 surrounding the oxidant gas discharge passage 14b will be referred to as the "communication hole seal portion 64b."

[0057] One end 106a (end in the direction of arrow B2) of the third tunnel 106 is located inside the communication hole seal portion 64. A third opening 110 that communicates with the third inner hole 108 is formed at one end 106a of the third tunnel 106. The third opening 110 communicates with a second communication space 112 between the oxidant gas discharge communication hole 14b and the communication hole seal portion 64. The other end 106b (end in the direction of arrow B1) of the third tunnel 106 is located inside the flow path seal portion 66.

[0058] As shown in Figs. 1 and 7, the second through-hole 102 is formed in the resin frame member 34. The second through-hole 102 is a slit extending in the direction of the arrow C. When viewed from the stacking direction of the power generating cells 10, 2 Through hole 102 overlaps with the other end 106b of the third tunnel 106 (see FIG. 6).

[0059] 1 and 3, the outlet channel 104 is provided in the second separator 26. The outlet channel 104 is located between the oxidant gas discharge passage 14b and the second gas channel 72. The outlet channel 104 has a plurality of fourth tunnels 114.

[0060] As shown in FIGS. 3 to 5, the multiple fourth tunnels 114 are lined up at intervals in the direction of arrow C. The fourth tunnels 114 extend in the direction of arrow B. As shown in FIG. 7, the fourth tunnels 114 bulge from the front surface 68 toward the back surface 70 of the second separator 26 (see FIG. 7). A fourth inner hole 116 through which the oxidant gas flows is formed inside the fourth tunnel 114. The fourth inner hole 116 of the fourth tunnel 114 communicates with the third inner hole 108 of the third tunnel 106 via the second through hole 102.

[0061] 6, when viewed from the stacking direction of the power generating cells 10, one end 114a (the end in the direction of arrow B2) of the fourth tunnel 114 overlaps with the second through hole 102. In other words, when viewed from the stacking direction of the power generating cells 10, the other end 106b of the third tunnel 106 overlaps with one end 114a of the fourth tunnel 114 and the second through hole 102. The other end 114b (the end in the direction of arrow B1) of the fourth tunnel 114 overlaps with B1 A fourth opening 118 is formed facing in the direction.

[0062] 3, an outlet buffer 98b is provided between the outlet flow path 104 and the second gas flow path 72. The outlet buffer 98b includes a plurality of embossed portions spaced apart in the direction of arrow C. The embossed portions bulge from the rear surface 70 of the second separator 26 toward the front surface 68 (in the direction of arrow A1 in FIG. 1).

[0063] A second adhesive layer 120 is provided on a surface 68 of the second separator 26 to bond the second separator 26 and the resin frame member 34 to each other. The second adhesive layer 120 is composed of an adhesive 122 that blocks the flow of the oxidizer gas, the fuel gas, and the cooling medium. The adhesive 122 is, for example, the same as the adhesive 56 of the first adhesive layer 54.

[0064] The second adhesive layer 120 is formed, for example, by applying a liquid adhesive 122 to the surface 68 of the second separator 26. The second adhesive layer 120 may also be formed by applying the liquid adhesive 122 to the other surface (the surface facing the second separator 26) of the resin frame member 34. The second adhesive layer 120 may also be formed by sandwiching an adhesive sheet of a predetermined shape made of the adhesive 122 between the second separator 26 and the resin frame member 34.

[0065] The second adhesive layer 120 surrounds the oxidant gas supply passage 14a, the oxidant gas discharge passage 14b, the fuel gas supply passage 16a, the fuel gas discharge passage 16b, the coolant supply passage 18a, and the coolant discharge passage 18b individually. The second adhesive layer 120 also surrounds the continuous flow passages including the inlet flow passage 82, the second gas flow passage 72, and the outlet flow passage 104.

[0066] 1, a second coolant flow field 124 is formed on the back surface 70 of the second separator 26. The second coolant flow field 124 has the shape of the back surface of the second gas flow field 72. When the multiple power generating cells 10 are stacked, the second coolant flow field 124 communicates with the first coolant flow field 58.

[0067] 3, an inlet buffer 126a is provided between the second coolant flow field 124 and the coolant supply passage 18a. The inlet buffer 126a includes a plurality of bosses arranged at intervals in the direction of arrow C. The bosses extend from the front surface 68 of the second separator 26 toward the back surface 70 (arrows in FIG. 1). A2 It bulges out in the opposite direction.

[0068] An outlet buffer 126b is provided between the second coolant flow field 124 and the coolant discharge passage 18b. The outlet buffer 126b includes a plurality of bosses spaced apart in the direction of arrow C. The bosses protrude from the front surface 68 of the second separator 26 toward the back surface 70 (in the direction of arrow A2 in FIG. 1).

[0069] The back surface 70 of the second separator 26 is not provided with the above-mentioned sealing member 62 .

[0070] The power generating cell 10 configured in this manner operates as follows.

[0071] First, as shown in FIG. 1, the fuel gas is supplied to the fuel gas supply passage 16a. The oxidizing gas is supplied to the oxidizing gas supply passage 14a. The cooling medium is supply Communication hole 18aare supplied to.

[0072] The fuel gas is introduced from the fuel gas supply passage 16a into the first gas flow channel 46 of the first separator 24. The fuel gas is supplied to the first electrode 38 of the membrane electrode assembly 32 while flowing through the first gas flow channel 46 in the direction of arrow B1.

[0073] On the other hand, the oxidant gas is introduced from the oxidant gas supply passage 14a through the first communication space 90, the first connection passage 78 (the first inner hole 86 of the first tunnel 84), the first through hole 80, and the introduction passage 82 (the second inner hole 94 of the second tunnel 92) into the second gas passage 72. The oxidant gas is supplied to the second electrode 40 of the membrane electrode assembly 32 while flowing through the second gas passage 72 in the direction of arrow B2.

[0074] In the membrane electrode assembly 32, the fuel gas supplied to the first electrode 38 and the oxidant gas supplied to the second electrode 40 are consumed by electrochemical reactions in the first electrode catalyst layer and the second electrode catalyst layer, resulting in power generation.

[0075] Next, the fuel gas that has been supplied to the first electrode 38 and partially consumed is discharged as fuel exhaust gas from the first gas flow passage 46 to the fuel gas discharge passage 16b. The oxidant gas that has been consumed at the second electrode 40 is discharged as oxidant exhaust gas from the second gas flow passage 72 through the outlet flow passage 104 (the fourth inner hole 116 of the fourth tunnel 114), the second through hole 102, and the second connection flow passage 100 (the third inner hole 108 of the third tunnel 106) to the oxidant gas discharge passage 14b.

[0076] cooling medium supply Communication hole 18a The cooling medium supplied to the separator 24 is introduced into the first cooling medium flow field 58 and the second cooling medium flow field 124 formed between the first separator 24 and the second separator 26. After being introduced into the first cooling medium flow field 58 and the second cooling medium flow field 124, the cooling medium flows in the direction of arrow B. After cooling the membrane electrode assembly 32, the cooling medium discharge Communication hole 18b is discharged from

[0077] The power generating cell 10 may be configured with the oxidant gas and fuel gas flow paths interchanged. In this case, the first electrode 38 serves as a cathode and the second electrode 40 serves as an anode. The oxidant gas flows through the first gas flow path 46 of the first separator 24, and the fuel gas flows through the second gas flow path 72 of the second separator 26.

[0078] [Inventions Obtained from the Embodiments] The invention that can be understood from the above embodiment will be described below.

[0079] One embodiment of the present invention is a power generation cell (10) comprising a resin-framed membrane electrode structure (22) having a membrane electrode structure (32) and a resin frame portion (34) provided on the outer periphery of the membrane electrode structure, a first separator (24) stacked on one side of the resin-framed membrane electrode structure, and a second separator (26) stacked on the other side of the resin-framed membrane electrode structure, in which the first separator and the second separator each have reactant gas communication holes (14a, 14b) formed therein that penetrate in the stacking direction and allow a reactant gas to flow, a reactant gas flow path (72) is formed in the second separator for flowing the reactant gas along the electrode surface of the membrane electrode structure, a connecting flow path (78, 100) communicating with the reactant gas communication hole is formed in the first separator, and a through hole (80, 102) is formed in the resin frame portion that communicates between the reactant gas flow path and the connecting flow path.

[0080] According to this configuration, the reactant gas flow passage formed in the second separator communicates with the reactant gas communication hole via the through hole formed in the resin frame member and the connecting flow passage formed in the first separator, which eliminates the need to form a connecting flow passage in the second separator, thereby increasing the degree of freedom in the layout of the flow passages formed in the second separator.

[0081] In the above-mentioned power generation cell, the reactant gas communication hole may include a reactant gas supply communication hole (14a, 16a) and a reactant gas discharge communication hole (14b, 16b), the connection flow path may include a first connection flow path (78) that communicates with the reactant gas supply communication hole and a second connection flow path (100) that communicates with the reactant gas discharge communication hole, and the through hole may include a first through hole (80) that connects the reactant gas flow path and the first connection flow path to each other, and a second through hole (102) that connects the reactant gas flow path and the second connection flow path to each other.

[0082] With this configuration, the degree of freedom in the layout of the flow paths formed in the second separator can be further increased.

[0083] In the above-mentioned power generating cell, the second separator may be formed with an inlet flow path (82) that introduces the reactant gas guided from the first through hole into the reactant gas flow path, and an outlet flow path (104) that guides the reactant gas that has circulated through the reactant gas flow path to the second through hole.

[0084] According to this configuration, the inlet flow passage can smoothly guide the reactant gas introduced from the first through hole to the reactant gas flow passage, and the outlet flow passage can smoothly guide the reactant gas that has flowed through the reactant gas flow passage to the second through hole.

[0085] The above-mentioned power generating cell may further include an adhesive layer (54) that bonds the first separator and the resin frame portion to each other, and the adhesive layer may individually surround the reactant gas flow path and the reactant gas communication hole and block the flow of the reactant gas.

[0086] According to this configuration, the reactive gas can be sealed off by the adhesive layer, so that the configuration of the power generating cell can be simplified.

[0087] Another aspect of the present invention is a fuel cell stack (12) in which a plurality of the above-described power generating cells are stacked.

[0088] In the above-mentioned fuel cell stack, a cooling medium flow path (58, 124) through which a cooling medium flows, a communication hole seal portion (64) surrounding the reactant gas communication hole, and a flow path seal portion (66) surrounding the cooling medium flow path are provided between the first separator and the second separator which are adjacent to each other, and the communication hole seal portion and the flow path seal portion may be provided only in the first separator of the first separator and the second separator.

[0089] According to this configuration, it is not necessary to provide the second separator with a communication hole seal portion and a flow path seal portion, so that the configuration of the second separator can be simplified.

[0090] In the above fuel cell stack, each of the communication hole seal portion and the flow path seal portion may be made of a rubber material.

[0091] The present invention is not limited to the above disclosure, and various configurations can be adopted without departing from the gist of the present invention. [Explanation of symbols]

[0092] 10…Power generation cell 12...Fuel cell stack 14a...oxidant gas supply passage 14b...Oxidant gas exhaust passage 16a...Fuel gas supply passage 16b...Fuel gas exhaust passage 22...Membrane electrode assembly with resin frame 24…First separator 26…Second separator 32...Membrane electrode structure 34...Resin frame member (resin frame portion) 36...Electrolyte membrane 38...1st electrode 40…Second electrode 46...First gas flow path (reaction gas flow path) 54...First adhesive layer (adhesive layer) 56…Glue 58...First cooling medium passage 64...Communication hole seal part 66…Flow passage seal part 72...Second gas flow path 78…First connecting channel 80…First through hole 82...Inlet channel 100...Second connecting flow path 102...Second through hole 104...Outlet flow path 120...Second adhesive layer 124...Second cooling medium flow passage

Claims

1. a resin frame-attached membrane electrode assembly having a membrane electrode assembly and a resin frame portion provided on an outer periphery of the membrane electrode assembly; a first separator laminated on one surface of the resin frame-equipped membrane electrode assembly; a second separator laminated on the other surface of the resin frame-equipped membrane electrode assembly; Equipped with Each of the first separator and the second separator has a first reactant gas supply passage and a first reactant gas discharge passage penetrating in the stacking direction and through which a first reactant gas flows; a second reactant gas supply passage and a second reactant gas discharge passage penetrating in the stacking direction and through which a second reactant gas flows; A power generating cell formed with The first separator includes: a first reactant gas flow path for passing the first reactant gas along one electrode surface of the membrane electrode assembly; a flow passage connecting the first reactant gas supply passage and the first reactant gas flow passage; a flow passage connecting the first reactant gas discharge passage and the first reactant gas flow passage; is formed, a second reactant gas flow path for passing the second reactant gas along the other electrode surface of the membrane electrode assembly is formed in the second separator; The first separator includes: a first connection passage communicating with the second reactant gas supply passage; a second connection passage communicating with the second reactant gas discharge passage; is formed, The resin frame portion has a first through hole that connects the second reactant gas flow passage and the first connection flow passage to each other; a second through hole that connects the second reactant gas flow passage and the second connection flow passage to each other; A power generating cell is formed.

2. The power generating cell according to claim 1 , The second separator includes: an introduction passage that introduces the second reaction gas introduced from the first through hole into the second reaction gas passage; an outlet flow passage configured to outlet the second reactant gas having flowed through the second reactant gas flow passage to the second through hole; A power generating cell is formed.

3. The power generating cell according to claim 1 , an adhesive layer that bonds the first separator and the resin frame to each other; A power generation cell, wherein the adhesive layer surrounds the first reactant gas flow path, the first reactant gas supply passage, and the first reactant gas discharge passage, and also individually surrounds the second reactant gas supply passage and the second reactant gas discharge passage, thereby preventing the flow of the first reactant gas and the second reactant gas.

4. A fuel cell stack comprising a plurality of power generating cells according to any one of claims 1 to 3 stacked together.

5. 5. The fuel cell stack according to claim 4, Between the first separator and the second separator adjacent to each other, a cooling medium flow path through which a cooling medium flows; a passage seal portion surrounding the first reactant gas supply passage, the first reactant gas discharge passage, the second reactant gas supply passage, and the second reactant gas discharge passage; a flow passage seal portion surrounding the coolant flow passage; is established, a first separator and a second separator, the first separator including a first through-hole seal portion and a second through-flow seal portion, the first separator including a first through-hole seal portion and a second through-flow seal portion, the second separator including a first through-hole seal portion and a second through-flow seal portion,

6. 6. The fuel cell stack according to claim 5, The fuel cell stack, wherein the communication hole seal portion and the flow path seal portion are each made of a rubber material.

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