JP2012048840A - Fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technique for improving the power generation performance of a fuel cell.SOLUTION: A cathode flow passage 60 of the fuel cell includes a cathode front-stage guide part 65 and a cathode rear-stage guide part 67 which guide an oxidation gas in an X-axial direction. The cathode front-stage guide part 65 has a primary closed flow passage 651 and a secondary closed flow passage 655 which extend on a cathode electrode in the X-axial direction and are provided side by side in a Y-axial direction, and the cathode rear-stage guide part 67 has a plurality of cathode rear-stage flow passages 675 which extend on the cathode electrode in the Y-axial direction and are provided side by side in the X-axial direction. The cathode front-stage guide part 65 and cathode rear-stage guide part 67 are provided side by side in the X-axial direction.

Description

  The present invention relates to a fuel cell, and more particularly to a gas flow path formed inside a fuel cell.

  The fuel cell includes a membrane electrode assembly (hereinafter also referred to as “MEA”) in which electrodes are joined to both surfaces of an electrolyte membrane, and a gas flow path for allowing a reaction gas to flow on each surface of the electrode in the MEA Is known. An anode channel for flowing a fuel gas as a reaction gas is formed on the surface of the anode electrode of the MEA electrode, and a cathode channel for flowing an oxidizing gas as a reaction gas on the surface of the cathode electrode of the MEA electrode. Is formed.

  Conventionally, a fuel cell in which comb-like channels are applied to an anode channel and a cathode channel has been proposed in order to increase the power generation efficiency of the fuel cell by actively dispersing the reaction gas inside the MEA electrode ( For example, Patent Document 1). The comb-shaped flow path is formed by separating the primary closed flow path communicating with the reaction gas supply side and the secondary closed flow path communicating with the reaction gas recovery side into a comb-tooth shape and meshing with each other. It is the formed obstruction | occlusion flow path.

JP 2005-85626 A

  However, in the case of the comb-shaped channel, since the reaction gas is actively dispersed inside the electrode, in a relatively high temperature environment, the MEA is easily dried due to the removal of moisture by the reaction gas, and the power generation performance. There was a problem that would decrease.

  In view of the above-described problems, an object of the present invention is to provide a technique for improving the power generation performance of a fuel cell.

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

[Application Example 1] The fuel cell of Application Example 1 is a fuel cell, and includes a membrane electrode assembly in which electrodes are respectively bonded to both surfaces of an electrolyte membrane, and a reactive gas on each surface of the electrode in the membrane electrode assembly. And at least one of the two gas passages extends on the surface of the electrode along the first direction and extends in the second direction intersecting the first direction. A plurality of first flow paths arranged alongside each other along the first direction for guiding the reaction gas in the first direction, and extending on the surface of the electrode along the second direction, respectively. And a plurality of second flow paths arranged in parallel with each other along the first direction, and a second induction part for inducing a reaction gas in the first direction, and with respect to the first induction part The second guide portion is arranged along the first direction.

  According to the fuel cell of Application Example 1, it is possible to guide the reaction gas in the first direction while actively dispersing the reaction gas inside the electrode in the second induction portion. Therefore, the membrane electrode assembly is provided by providing the second induction portion in a dry-like region where a wet-like reaction gas flows or a wet-like region where a dry-like reaction gas flows, among the regions in the membrane electrode assembly. Moisture movement between the electrodes can be promoted to prevent the membrane electrode assembly from drying. As a result, the power generation performance of the fuel cell can be improved.

Application Example 2 In the fuel cell according to Application Example 1, at least one of the two gas flow paths is a cathode flow path for flowing an oxidizing gas as the reaction gas on the surface of the cathode electrode of the electrodes. The second guiding part of the cathode channel may guide the oxidizing gas that has passed through the first guiding part of the cathode channel in the first direction. According to the fuel cell of Application Example 2, the oxidizing gas humidified by the generated water accompanying power generation while passing through the first induction part of the cathode flow path is positively applied to the cathode electrode in the second induction part of the cathode flow path. Can diffuse. Thereby, moisture movement from the cathode electrode to the inside of the membrane electrode assembly can be promoted.

Application Example 3 The fuel cell according to Application Example 2, further including a cathode recovery unit that recovers the oxidizing gas from the cathode flow path, wherein the second induction part of the cathode flow path includes the plurality of second electrodes. It is good also as including the cathode communication part which connects one edge part in each of two flow paths to the said collection | recovery part. According to the fuel cell of Application Example 3, when the fuel cell is installed such that the cathode communication portion is positioned below the plurality of second flow paths in the gravity direction, the liquid water generated in the second induction portion of the cathode flow path Can be discharged to the cathode recovery section through the cathode communication section. As a result, it is possible to prevent stagnation of generated water that inhibits the diffusion of the oxidizing gas to the cathode electrode in the second induction portion of the cathode flow path.

Application Example 4 The fuel cell according to Application Example 1 to Application Example 3, wherein at least one of the two gas flow paths has a fuel gas as the reaction gas on the surface of the anode electrode among the electrode surfaces. The first guiding part of the anode channel may guide the fuel gas that has passed through the second guiding part of the anode channel in the first direction. According to the fuel cell of the application example 4, the fuel gas that is positively diffused and humidified to the anode electrode in the second induction part of the anode flow path flows on the surface of the anode electrode in the first induction part of the anode flow path. be able to. Thereby, moisture movement from the inside of the membrane electrode assembly to the anode electrode can be promoted.

Application Example 5 In the fuel cell according to Application Example 1 to Application Example 4, the flow of each reaction gas in the two gas flow paths may be a counter flow that flows in directions opposite to each other. . According to the fuel cell of Application Example 5, the movement of moisture from the downstream side of the cathode electrode to the upstream side of the anode electrode is promoted, and drying of the membrane electrode assembly can be further prevented.

Application Example 6 In the fuel cell according to Application Example 1 to Application Example 5, the plurality of first flow paths are closed flow paths formed in a comb-like shape that are separated from each other and mesh with each other. Also good. According to the fuel cell of Application Example 6, it is possible to prevent the membrane electrode assembly from being dried in the fuel cell to which the comb-shaped flow path is applied.

  The form of the present invention is not limited to a fuel cell, and can be applied to various forms such as a fuel cell component, a vehicle equipped with a fuel cell, and a fuel cell system that operates the fuel cell. Further, the present invention is not limited to the above-described embodiments, and it is needless to say that the present invention can be implemented in various forms without departing from the spirit of the present invention.

It is explanatory drawing which shows the structure of a fuel cell. It is explanatory drawing which shows the detailed structure of an anode separator. It is explanatory drawing which shows the detailed structure of a cathode separator.

  In order to further clarify the configuration and operation of the present invention described above, a fuel cell to which the present invention is applied will be described below.

A. Example:
FIG. 1 is an explanatory diagram showing the configuration of the fuel cell 10. The fuel cell 10 generates electricity electrochemically using a reaction gas. In the present embodiment, the fuel cell 10 is a solid polymer type fuel cell, and uses a fuel gas and an oxidizing gas as reaction gases. In this embodiment, the fuel gas is a gas containing hydrogen, and the oxidizing gas is a gas containing oxygen.

  In this embodiment, the fuel gas used in the fuel cell 10 is hydrogen gas stored in a storage tank. However, in other embodiments, it may be hydrogen gas stored in a hydrogen storage alloy or carbonized. Hydrogen gas obtained by reforming a hydrogen fuel may be used. In this embodiment, the oxidizing gas used in the fuel cell 10 is air taken from outside air.

  The fuel cell 10 includes a plurality of cells 15 that perform an electrochemical reaction that directly extracts electricity from a reaction gas, and the plurality of cells 15 are stacked on each other. The cell 15 of the fuel cell 10 includes a membrane electrode assembly (MEA) 20, an anode separator 30, and a cathode separator 50. The MEA 20 is sandwiched between the anode separator 30 and the cathode separator 50.

  The MEA 20 of the fuel cell 10 includes an electrolyte membrane 210, an anode electrode 230, and a cathode electrode 250. The anode electrode 230 of the MEA 20 includes an anode catalyst layer 231 and an anode diffusion layer 235, and the cathode electrode 250 of the MEA 20 includes a cathode catalyst layer 251 and a cathode diffusion layer 255. An anode electrode 230 is bonded to one surface of the electrolyte membrane 210 by laminating an anode catalyst layer 231 and an anode diffusion layer 235 in this order. The cathode electrode 250 is bonded to the other surface of the electrolyte membrane 210 by laminating the cathode catalyst layer 251 and the cathode diffusion layer 255 in this order.

  The electrolyte membrane 210 of the MEA 20 is a proton conductor having proton conductivity. In this embodiment, the electrolyte membrane 210 is a perfluorosulfonic acid ion exchange membrane using an ionomer resin. The anode catalyst layer 231 and the cathode catalyst layer 251 of the MEA 20 are formed of a material having gas permeability and conductivity and supporting a catalyst (for example, platinum or platinum alloy) that promotes an electrochemical reaction between hydrogen and oxygen. In this embodiment, it is formed of a carbon support carrying a platinum-based catalyst. The anode diffusion layer 235 and the cathode diffusion layer 255 of the MEA 20 are formed of a material having gas permeability and conductivity. For example, the anode diffusion layer 235 and the cathode diffusion layer 255 can be formed of carbon cloth or carbon paper which is a carbon porous body.

  The anode separator 30 of the fuel cell 10 forms an anode flow path 40 through which fuel gas flows on the anode surface, which is the surface of the MEA 20 on the anode diffusion layer 235 side, and the cathode separator 50 of the fuel cell 10 A cathode channel 60 for flowing an oxidizing gas is formed on the cathode surface which is the side surface. In this embodiment, the flow of the fuel gas in the anode flow path 40 and the flow of the oxidizing gas in the cathode flow path 60 are counterflows that flow in directions corresponding to each other.

  The anode separator 30 and the cathode separator 50 have sufficient conductivity for collecting electricity generated in the MEA 20, and have sufficient durability, heat resistance, and gas impermeability for flowing a reaction gas through the MEA 20. In this embodiment, the anode separator 30 and the cathode separator 50 are made of carbon resin. However, in other embodiments, the anode separator 30 and the cathode separator 50 may be made of stainless steel, titanium, a titanium alloy, or conductive ceramics. In this embodiment, the anode separator 30 and the cathode separator 50 are separately configured. However, in other embodiments, the anode separator 30 and the cathode separator 50 may be integrally configured.

  FIG. 2 is an explanatory diagram showing a detailed configuration of the anode separator 30. FIG. 2 illustrates the shape of the anode separator 30 as viewed from the MEA 20 side. In FIG. 2, the flow of the fuel gas is illustrated using a white arrow, and the flow of the fuel gas passing through the anode diffusion layer 235 is illustrated using a dashed arrow. In the present embodiment, the shape of the anode separator 30 viewed from the MEA 20 side is a rectangle.

  The anode separator 30 includes an outer wall portion 310, holes 311 to 316, a flow path wall portion 330, a flow path wall portion 350, and a protruding portion 370. The outer wall portion 310 and the flow path wall portions 330 and 350 of the anode separator 30 are portions that contact the anode electrode 230 side of the MEA 20.

  The anode separator 30 forms an anode channel 40 as a channel partitioned between each part of the anode separator 30 and the MEA 20. The anode flow path 40 includes an anode supply unit 41, an anode front stage induction unit 43, an anode rear stage induction unit 45, and an anode recovery unit 48. In FIG. 2, the outer wall portion 310, the flow passage wall portions 330 and 350, and the protruding portion 370 of the anode separator 30 are hatched in order to facilitate the shape recognition of the anode flow passage 40 formed by the anode separator 30.

  The holes 311 to 316 of the anode separator 30 form holes that penetrate the anode separator 30. The hole 311, the hole 312, and the hole 313 are sequentially provided along one short side of the rectangular anode separator 30, and the hole 314, the hole 315, and the hole 316 are the other of the rectangular anode separator 30. Are provided in order along the short side.

  In this embodiment, the hole 311 constitutes a part of a flow path for flowing fuel gas to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 316 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the fuel gas recovered from each of the 15 flows. In this embodiment, the hole 314 constitutes a part of a flow path for flowing an oxidizing gas to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 313 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the oxidizing gas recovered from each of the 15 flows. In the present embodiment, the hole 312 constitutes a part of a flow path for flowing cooling water to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 315 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the cooling water recovered from each of the 15 flows.

  In the description of the present embodiment, the direction from the hole 311 to the hole 314 along the long side of the rectangular anode separator 30 is defined as the X-axis direction that is the first direction, and the short side of the rectangular anode separator 30 is A direction from the hole portion 311 toward the hole portion 313 along the Y axis direction is defined as the second direction. In this embodiment, the X axis and the Y axis are orthogonal to each other.

  The outer wall portion 310 of the anode separator 30 surrounds the power generation region 25 corresponding to a portion where power generation is performed in the MEA 20 in a state of being in contact with the anode diffusion layer 235 of the MEA 20. In the anode separator 30, the power generation region 25 communicates with the hole 311 on the fuel gas supply side and the hole 316 on the fuel gas recovery side, and the holes 314 and 313 for the oxidizing gas, and the cooling Isolated from the holes 312 and 315 for water. The power generation region 25 includes a first region 21 in which the anode front stage guiding portion 43 is formed, and a second region 22 in which the anode rear stage guiding portion 45 is formed. In the present embodiment, the power generation region 25 is rectangular, and the first region 21 and the second region 22 are partitioned along the Y-axis direction. In the present embodiment, the area of the second region 22 is larger than the area of the first region 21.

  The anode supply part 41 of the anode flow path 40 is formed from the hole 311 of the anode separator 30 to the first region 21 of the power generation region 25. The anode supply unit 41 is a flow path that communicates between the hole 311 and the power generation region 25, and supplies fuel gas to the power generation region 25.

  The anode recovery part 48 of the anode channel 40 is formed from the second region 22 of the power generation region 25 to the hole 316 of the anode separator 30. The anode collection unit 48 is a flow path that communicates between the power generation region 25 and the hole 316, and collects fuel gas from the power generation region 25. In this embodiment, the anode recovery part 48 is provided with a plurality of protrusions 370 protruding toward the MEA 20 in a state of being separated from each other in order to adjust the flow of the fuel gas.

  The flow path wall 330 of the anode separator 30 extends on the anode diffusion layer 235 along the Y-axis direction, and the anode pre-stage guide 43 of the anode flow path 40 is in contact with the anode diffusion layer 235 of the MEA 20. Form. The anode front stage induction unit 43 is arranged in parallel along the X axis direction between the anode supply unit 41 and the anode rear stage induction unit 45, and flows a second fuel gas in the X axis direction in the first region 21 of the power generation region 25. It has a plurality of anode front-stage flow paths 435 which are guide sections and are a plurality of second flow paths.

  The plurality of anode front-stage flow paths 435 in the anode front-stage induction section 43 are partitioned by the flow path wall section 330, extend on the anode diffusion layer 235 along the Y-axis direction, and are arranged side by side along the X-axis direction. Is done. The anode upstream flow paths 435 are blocked by the flow path wall 330, but the fuel gas can be guided between the anode upstream flow paths 435 through the anode diffusion layer 235 in contact with the flow path wall 330. Is possible. As a result, the anode pre-stage induction unit 43 diffuses the fuel gas in the anode diffusion layer 235 of the MEA 20 while guiding the fuel gas supplied from the anode supply unit 41 to the anode post-stage induction unit 45 in the X-axis direction.

  In the present embodiment, the lengths of the flow path wall 330 and the anode upstream flow path 435 along the Y-axis direction are equal to the width W1 of the power generation region 25 along the X-axis direction. The number of the anode pre-stage flow paths 435 may be plural, and in this embodiment, the number is three. However, in other embodiments, the number may be two, or may be four or more.

  The flow path wall 350 of the anode separator 30 extends on the anode diffusion layer 235 along the X-axis direction, and the anode rear-stage induction part 45 of the anode flow path 40 is in contact with the anode diffusion layer 235 of the MEA 20. Form. The anode rear stage induction unit 45 is provided in parallel along the X axis direction between the anode front stage induction unit 43 and the anode recovery unit 48, and the first gas flow in the X axis direction in the second region 22 of the power generation region 25. It is a guide part, and has a primary closed channel 451 and a secondary closed channel 455 which are a plurality of first channels.

  The primary closed channel 451 and the secondary closed channel 455 in the anode rear stage guiding section 45 are partitioned by the channel wall 350, extend on the anode diffusion layer 235 along the X-axis direction, and extend along the Y-axis direction. Are juxtaposed with each other. In the present embodiment, the anode rear-stage guiding portion 45 constitutes a closed channel formed in a comb-like shape that is separated and meshed with each other, and the primary closed channel 451 is a comb-tooth communicating with the anode front-stage guide unit 43 side. The secondary closed channel 455 is a comb channel that communicates with the anode recovery unit 48 side.

  The primary closed channel 451 and the secondary closed channel 455 are mutually closed by the channel wall portion 350, but the secondary blocked channel 451 and the secondary blocked channel 455 are separated from the primary blocked channel 451 through the anode diffusion layer 235 in contact with the channel wall portion 350. It is possible to guide the fuel gas to the closed channel 455. As a result, the anode rear stage guiding unit 45 diffuses the fuel gas in the anode diffusion layer 235 of the MEA 20 while guiding the fuel gas that has passed through the anode front stage guiding unit 43 to the anode recovery unit 48 in the X-axis direction.

  FIG. 3 is an explanatory view showing the detailed structure of the cathode separator 50. FIG. 3 shows the shape of the cathode separator 50 viewed from the MEA 20 side. In FIG. 3, the flow of the oxidizing gas is illustrated using a white arrow, and the flow of the oxidizing gas passing through the cathode diffusion layer 255 is illustrated using a dashed arrow. In the present embodiment, the shape of the cathode separator 50 viewed from the MEA 20 side is a rectangle like the anode separator 30.

  The cathode separator 50 includes an outer wall 510, holes 511 to 516, a protrusion 520, a channel wall 550, and a channel wall 570. The outer wall portion 510 and the flow path wall portions 550 and 570 of the cathode separator 50 are portions that abut on the cathode electrode 250 side of the MEA 20.

  The cathode separator 50 forms a cathode channel 60 as a channel partitioned between each part of the cathode separator 50 and the MEA 20. The cathode channel 60 includes a cathode supply unit 61, a cathode pre-stage induction unit 65, a cathode post-stage induction unit 67, and a cathode recovery unit 68. In FIG. 3, in order to facilitate the shape recognition of the cathode channel 60 formed by the cathode separator 50, the outer wall portion 510, the protruding portion 520, and the channel walls 550 and 570 are hatched.

  The holes 511 to 516 of the cathode separator 50 form holes that penetrate the cathode separator 50. The hole portion 511, the hole portion 512, and the hole portion 513 are provided in order along one short side of the rectangular cathode separator 50, and the hole portion 514, the hole portion 515, and the hole portion 516 are provided on the other side of the rectangular cathode separator 50. Are provided in order along the short side.

  In the present embodiment, the hole 511 constitutes a part of a flow path for supplying fuel gas to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 516 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the fuel gas recovered from each of the 15 flows. In the present embodiment, the hole 514 constitutes a part of a flow path for flowing an oxidizing gas to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 513 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the oxidizing gas recovered from each of the 15 flows. In the present embodiment, the hole 512 constitutes a part of a flow path for flowing cooling water to be supplied to each of the plurality of cells 15 in the fuel cell 10, and the hole 515 is a plurality of cells in the fuel cell 10. 15 constitutes a part of the flow path through which the cooling water recovered from each of the 15 flows.

  The X-axis direction defined in the description of the anode separator 30 corresponds to the direction from the hole 511 toward the hole 514 along the short side of the rectangular cathode separator 50. The Y-axis direction defined in the description of the anode separator 30 corresponds to the direction from the hole 511 toward the hole 513 along the long side of the rectangular cathode separator 50.

  The outer wall portion 510 of the cathode separator 50 surrounds the power generation region 25 in a state of being in contact with the cathode diffusion layer 255 of the MEA 20. In the cathode separator 50, the power generation region 25 communicates with a hole 514 on the oxidizing gas supply side and a hole 513 on the oxidizing gas recovery side, and holes 511 and 516 for fuel gas and cooling Separated from holes 512 and 515 for water.

  The cathode supply part 61 of the cathode channel 60 is formed from the hole 514 of the cathode separator 50 to the second region 22 of the power generation region 25. The cathode supply unit 61 is a flow path that communicates between the hole 514 and the power generation region 25, and supplies an oxidizing gas to the power generation region 25. In this embodiment, the cathode supply unit 61 has a plurality of protrusions 520 protruding toward the MEA 20 in a state of being separated from each other in order to adjust the flow of the oxidizing gas.

  The cathode recovery part 68 of the cathode channel 60 is formed from the first region 21 of the power generation region 25 to the hole 513 of the cathode separator 50. The cathode recovery unit 68 is a flow path that communicates between the power generation region 25 and the hole 513 and recovers the oxidizing gas from the power generation region 25.

  The channel wall portion 550 of the cathode separator 50 extends to the cathode diffusion layer 255 along the X-axis direction, and forms the cathode pre-stage guiding portion 65 of the cathode channel 60 in a state of being in contact with the cathode diffusion layer 255 of the MEA 20. To do. The cathode front-stage induction unit 65 is arranged in parallel along the X-axis direction between the cathode supply unit 61 and the cathode rear-stage induction unit 67, and the first gas flows in the X-axis direction in the second region 22 of the power generation region 25. It is a guide part and has a primary closed channel 651 and a secondary closed channel 655 which are a plurality of first channels.

  The primary closed channel 651 and the secondary closed channel 655 in the cathode pre-stage guide unit 65 are defined by the channel wall 550, extend on the cathode diffusion layer 255 along the X-axis direction, and extend along the Y-axis direction. Are juxtaposed with each other. In the present embodiment, the cathode pre-stage guide unit 65 constitutes a closed channel formed in a comb-teeth shape that is separated and meshed with each other, and the primary closed channel 651 is connected to the cathode supply unit 61 side. The secondary blocking channel 655 is a comb-shaped channel communicating with the cathode rear-stage guiding unit 67 side.

  Although the primary closed channel 651 and the secondary closed channel 655 are mutually closed by the channel wall portion 550, the secondary blocked channel 651 and the secondary blocked channel 655 are separated from the primary blocked channel 651 through the cathode diffusion layer 255 in contact with the channel wall portion 550. It is possible to induce an oxidizing gas into the closed channel 655. As a result, the cathode pre-stage induction unit 65 diffuses the oxidation gas to the cathode diffusion layer 255 of the MEA 20 while guiding the oxidation gas that has passed through the cathode supply unit 61 to the cathode post-stage induction unit 67 in the X-axis direction.

  The channel wall portion 570 of the cathode separator 50 extends on the cathode diffusion layer 255 along the Y-axis direction, and the cathode rear-stage induction unit 67 of the cathode channel 60 is in contact with the cathode diffusion layer 255 of the MEA 20. Form. The cathode rear-stage induction unit 67 is arranged in parallel along the X-axis direction between the cathode front-stage induction unit 65 and the cathode recovery unit 68, and the second gas flow in the X-axis direction in the first region 21 of the power generation region 25. It has a plurality of cathode rear-stage flow paths 675 that are induction sections and are a plurality of second flow paths.

  The plurality of cathode rear-stage flow paths 675 in the cathode rear-stage induction section 67 are partitioned by the flow path wall section 570, extend on the cathode diffusion layer 255 along the Y-axis direction, and are arranged in parallel along the X-axis direction. Is done. The cathode rear-stage flow paths 675 are blocked by the flow-path wall part 570, but the oxidizing gas can be induced between the cathode rear-stage flow paths 675 through the cathode diffusion layer 255 in contact with the flow-path wall part 570. Is possible. Thus, the cathode rear stage induction unit 67 diffuses the oxidation gas into the cathode diffusion layer 255 of the MEA 20 while guiding the oxidation gas that has passed through the cathode front stage induction unit 65 to the cathode recovery unit 68 in the X-axis direction.

  In the present embodiment, the cathode rear-stage guiding section 67 includes a cathode communication section 678 that communicates each end of the plurality of cathode rear-stage flow paths 675 on the hole 513 side to the cathode recovery section 68. In this embodiment, the fuel cell 10 is installed such that the cathode communication portion 678 is positioned below the plurality of cathode rear-stage flow paths 675 in the gravity direction, and the generated water generated in the plurality of cathode rear-stage flow paths 675 It is discharged to the hole 513 through the communication part 678.

  In the present embodiment, the lengths of the channel wall portion 570 and the cathode downstream channel 675 along the Y-axis direction are shorter than the width W1 of the power generation region 25 along the X-axis direction by the cathode communication portion 678. The number of the cathode rear-stage flow paths 675 may be plural, and in this embodiment, the number is three. However, in other embodiments, the number may be two, or may be four or more.

  According to the fuel cell 10 described above, in the cathode channel 60, the oxidizing gas humidified by the generated water accompanying power generation while passing through the cathode front-stage induction unit 65 is positively applied to the cathode diffusion layer 255 in the cathode rear-stage induction unit 67. Can be diffused. Thereby, the movement of moisture from the cathode electrode 250 side to the anode electrode 230 side can be promoted in the first region 21 of the power generation region 25. As a result, drying of the MEA 20 can be prevented.

  Further, in the anode flow path 40, the fuel gas that is positively diffused and humidified in the anode diffusion layer 235 in the anode front stage induction section 43 can flow to the anode diffusion layer 235 in the anode rear stage induction section 45. Thereby, the movement of moisture from the cathode electrode 250 side to the anode electrode 230 side can be promoted in the first region 21 of the power generation region 25. As a result, drying of the MEA 20 can be prevented.

  In addition, since the cathode rear-stage guiding portion 67 of the cathode channel 60 includes the cathode communication portion 678, the fuel cell 10 is installed such that the cathode communication portions 678 are located below the plurality of cathode rear-channel channels 675 in the gravity direction. The liquid water generated in the cathode downstream flow path 675 can be discharged to the hole 513 through the cathode communication part 678. As a result, it is possible to prevent stagnation of generated water that hinders the diffusion of the oxidizing gas to the cathode electrode 250 in the cathode rear stage induction unit 67.

  In addition, since the flow of the fuel gas in the anode flow path 40 and the flow of the oxidizing gas in the cathode flow path 60 are counterflows that flow in directions opposite to each other, in the first region 21 of the power generation region 25, By the induction part 65 and the anode rear stage induction part 45, the movement of moisture from the cathode electrode 250 side to the anode electrode 230 side can be further promoted.

B. Other embodiments:
Although the embodiments of the present invention have been described above, the present invention is not limited to these embodiments, and can of course be implemented in various forms without departing from the spirit of the present invention. is there. For example, in the present embodiment, the gas flow path including the first induction section and the second induction section is both the anode flow path 40 and the cathode flow path 60, but in other embodiments, the anode flow path 40 and the cathode flow path. One of the flow paths 60 may be used.

  Further, in this embodiment, the cathode rear-stage guiding portion 67 of the cathode flow channel 60 includes the cathode communication portion 678. However, in other embodiments, both ends are blocked in the same manner as the anode front-stage guiding portion 43 of the anode flow path 40. It may be a gas flow path.

  The anode post-stage guiding portion 45 of the anode flow path 40 and the cathode pre-stage guiding section 65 of the cathode flow path 60 are not limited to comb-shaped flow paths, and may be other closed flow paths, and both ends penetrated. It may be a through channel.

DESCRIPTION OF SYMBOLS 10 ... Fuel cell 15 ... Cell 20 ... Membrane electrode assembly (MEA)
DESCRIPTION OF SYMBOLS 21 ... 1st area | region 22 ... 2nd area | region 25 ... Electric power generation area 30 ... Anode separator 40 ... Anode flow path 41 ... Anode supply part 43 ... Anode pre-stage induction | guidance | derivation part 45 ... Anode back | latter stage induction | guidance | derivation part 48 ... Anode collection | recovery part 50 ... Cathode separator 60 ... Cathode flow path 61 ... Cathode supply section 65 ... Cathode pre-stage induction section 67 ... Cathode post-stage induction section 68 ... Cathode recovery section 210 ... Electrolyte membrane 230 ... Anode electrode 231 ... Anode catalyst layer 235 ... Anode diffusion layer 250 ... Cathode electrode 251 ... Cathode catalyst layer 255 ... Cathode diffusion layer 310 ... Outer wall parts 311 to 316 ... Hole part 330, 350 ... Channel wall part 370 ... Projection part 435 ... Anode pre-stage channel 451 ... Primary blocked channel 455 ... Secondary blocked channel 510 ... Outer wall part 511-516 ... Hole part 520 ... Protrusion part 550,570 Flow channel wall 651 ... primary closed flow path 655 ... secondary closed channel 675 ... cathode subsequent passage 678 ... cathode communicating portion

Claims (6)

A fuel cell,
A membrane electrode assembly in which electrodes are respectively bonded to both surfaces of the electrolyte membrane;
Two gas flow paths for flowing a reaction gas on each surface of the electrode in the membrane electrode assembly,
At least one of the two gas flow paths is
A plurality of first flow paths extending along the first direction on the surface of the electrode and arranged in parallel along a second direction intersecting the first direction, the first direction; A first induction part for inducing a reaction gas into
A plurality of second flow paths extending on the surface of the electrode along the second direction and arranged in parallel with each other along the first direction, and inducing a reactive gas in the first direction A second guiding part that
A fuel cell in which the second guide portion is arranged along the first direction with respect to the first guide portion. The fuel cell according to claim 1,
At least one of the two gas flow paths is a cathode flow path for flowing an oxidizing gas as the reaction gas on the surface of the cathode electrode of the electrodes,
The fuel cell, wherein the second guiding portion of the cathode flow channel guides an oxidizing gas that has passed through the first guiding portion of the cathode flow channel in the first direction. The fuel cell according to claim 2, wherein
Furthermore, a cathode recovery part for recovering the oxidizing gas from the cathode flow path,
The second induction part of the cathode flow path includes a cathode communication part that communicates one end of each of the plurality of second flow paths to the recovery part. A fuel cell according to any one of claims 1 to 3, wherein
At least one of the two gas flow paths is an anode flow path for flowing fuel gas as the reaction gas on the surface of the anode electrode among the electrode surfaces,
The fuel cell, wherein the first guide portion of the anode channel guides fuel gas that has passed through the second guide portion of the anode channel in the first direction.   The fuel cell according to any one of claims 1 to 4, wherein the flow of each reactive gas in the two gas flow paths is a counterflow that flows in directions opposite to each other.   6. The fuel cell according to claim 1, wherein the plurality of first flow paths are closed flow paths formed in a comb-teeth shape that are separated from each other and mesh with each other.

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