JP2005235727A - Fuel cell, thin film for fuel cell and manufacturing method of thin film for fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell in which moisture can be moved with a simple structure, a thin film for the fuel cell, and a manufacturing method of the thin film for the fuel cell. <P>SOLUTION: This is a fuel cell 10 which generates electric power by receiving supply of anode gas containing hydrogen to an anode and receiving supply of cathode gas containing oxygen to a cathode. The fuel cell comprises an electrolyte membrane 12, a catalyst layer 14 installed on the electrolyte membrane 12, a diffusion layer 16 installed on the catalyst layer 14, and a separator 19 which is installed on the diffusion layer 16 and has a cathode gas passage 22. A moisture movement promoting film 34 made of a prescribed fabric is installed in the vicinity of the cathode gas passage 22. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell, a fuel cell thin film, and a method for producing a fuel cell thin film that generate power by reacting hydrogen supplied to an anode with oxygen supplied to a cathode.

  The fuel cell generates electric power by reacting hydrogen supplied to the anode and oxygen supplied to the cathode. In such a fuel cell, Japanese Patent Application Laid-Open No. 2003-109620 discloses a configuration in which the cathode flow path of the separator meanders in an S shape and the upstream side and the downstream side of the flow path are adjacent to each other. A configuration is disclosed in which moisture can be moved from the downstream side to the upstream side of the cathode channel via a capillary tube formed on the end face of the rib portion.

  Japanese Patent Application Laid-Open No. 9-283157 discloses that the water produced at the cathode can be supplied to the cooling gas passage through the water-permeable resin disposed in the separator. Discloses a technique for flowing a gas supplied to the cathode.

JP 2003-109620 A JP-A-9-283157

  However, in the method disclosed in Japanese Patent Application Laid-Open No. 2003-109620, moisture is moved via a capillary tube, so that the configuration of the cathode flow path becomes complicated and the design freedom of the fuel cell is reduced. Occurs. In addition, since a complicated process is required to form the capillary tube, there is a problem that the manufacturing cost of the fuel cell increases.

  Further, in the technique disclosed in Japanese Patent Application Laid-Open No. 9-283157, moisture is discharged out of the fuel cell due to the cathode air flow, and the generated water is not sufficiently supplied to the cooling gas flow path. The electrolyte membrane may be dried and the power generation performance of the fuel cell may be reduced.

  The present invention has been made to solve the above-described problems, and provides a fuel cell, a fuel cell thin film, and a fuel cell thin film manufacturing method capable of moving moisture with a simple configuration. Objective.

  In order to achieve the above object, a first invention is a fuel cell that receives supply of an anode gas containing hydrogen to an anode and a cathode gas containing oxygen to a cathode to generate electric power, A moisture moving means made of a predetermined fiber is provided in the vicinity of the cathode gas flow path.

  According to a second invention, in the first invention, the predetermined fiber has at least one concave portion in a cross-sectional shape thereof.

  A third invention is characterized in that, in the first or second invention, the extending direction of the predetermined fiber is aligned in a certain direction.

  According to a fourth aspect of the present invention, in any one of the first to third aspects, the predetermined fiber is a carbon fiber.

  According to a fifth invention, in any one of the first to fourth inventions, the moisture moving means is provided on at least a part of an inner wall of the cathode gas flow path.

  According to a sixth invention, in any one of the first to fourth inventions, an electrolyte membrane for reacting hydrogen in the anode gas and oxygen in the cathode gas, and a catalyst layer provided on the electrolyte membrane; A diffusion layer provided on the catalyst layer; and a separator provided on the diffusion layer and provided with a flow path for the cathode gas, wherein the moisture transfer means includes the electrolyte membrane and the catalyst layer. , Disposed in at least one of the diffusion layer and the separator.

  According to a seventh invention, in any one of the first to fourth inventions, an electrolyte membrane for reacting hydrogen in the anode gas and oxygen in the cathode gas, and a catalyst layer provided on the electrolyte membrane; A diffusion layer provided on the catalyst layer; and a separator provided on the diffusion layer and provided with a flow path for the cathode gas, wherein the moisture transfer means includes the electrolyte membrane and the catalyst layer. The diffusion layer or the separator is disposed at the interface.

  In order to achieve the above object, an eighth invention is a fuel cell that receives supply of an anode gas containing hydrogen to the anode and a supply of cathode gas containing oxygen to the cathode to generate electric power, An electrolyte membrane for reacting hydrogen in the anode gas and oxygen in the cathode gas, a catalyst layer provided on the electrolyte membrane, a diffusion layer provided on the catalyst layer, and a diffusion layer on the diffusion layer A separator provided with a flow path for the cathode gas, wherein the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator includes a predetermined fiber that promotes the movement of moisture. And

  In a ninth aspect based on the eighth aspect, the predetermined fiber has at least one concave portion in its cross-sectional shape.

  A tenth invention is characterized in that, in the eighth or ninth invention, the extending direction of the predetermined fiber is aligned in a certain direction.

  According to an eleventh aspect of the present invention, in any one of the eighth to tenth aspects, the predetermined fiber is a carbon fiber.

  A twelfth aspect of the present invention is a thin film for a fuel cell, which is formed by weaving predetermined fibers and extending only in a predetermined direction, and has at least one recess in its cross-sectional shape to achieve the above object. It is characterized by having.

  In a thirteenth aspect based on the twelfth aspect, the predetermined fiber is a carbon fiber.

  In order to achieve the above object, the fourteenth invention is a thin film for a fuel cell, characterized in that a predetermined fiber is glued and the extending direction of the fiber is aligned in a predetermined direction. To do.

  In a fifteenth aspect based on the fourteenth aspect, the predetermined fiber has at least one concave portion in its cross-sectional shape.

  In a sixteenth aspect based on the fourteenth or fifteenth aspect, the predetermined fiber is a carbon fiber.

  A seventeenth aspect of the invention is a method for producing a thin film for a fuel cell in order to achieve the above object, wherein a coal-based or petroleum-based pitch is extruded from a mold having at least one recess and has a cross-sectional shape of at least 1. It has the process of forming the carbon fiber which has one recessed part, and the process of forming the thin film for fuel cells using the said carbon fiber.

  An eighteenth invention is a method for producing a thin film for a fuel cell in order to achieve the above object, wherein a fiber material made of a polymer material is extruded from a mold having at least one convex portion, and at least 1 in cross-sectional shape. A step of forming a fiber having two recesses, a step of carbonizing the fiber to form a carbon fiber, and a step of forming a thin film for a fuel cell using the carbon fiber. And

  A nineteenth aspect of the invention is a method for producing a thin film for a fuel cell in order to achieve the above object, wherein a warp yarn having at least one concave portion in a cross-sectional shape and a weft yarn having no concave portion in a cross-sectional shape are woven. Forming a fuel cell thin film.

  In order to achieve the above object, a twentieth aspect of the invention is a method for producing a thin film for a fuel cell, the step of aligning the extending direction of fibers constituting the thin film for a fuel cell, and aligning the extending direction of the fibers And a step of gluing the fibers in a state where they are in contact with each other.

  In a twenty-first aspect, in the twentieth aspect, in the step of aligning the extending direction of the fibers, a plate material having grooves on the surface is used, and the extending direction of the fibers is determined by inserting the fibers into the grooves. It is characterized by aligning.

  According to a twenty-second aspect, in the twentieth aspect, in the step of aligning the extending direction of the fibers, ultrasonic vibration or mechanical vibration is applied to align the extending direction of the fibers.

  According to a twenty-third aspect of the present invention, in any one of the first to fifth aspects of the present invention, a separator disposed adjacent to the cathode and provided with a flow path for the cathode gas, and a flow path for the cathode gas A gas flow path that is disposed on the back side of the separator and that supplies the cathode gas to the flow path of the cathode gas; and a gas flow path that is disposed in at least a part of the separator and that flows from the flow path of the cathode gas to the gas flow path. And a porous part for sending moisture to the water.

  According to a twenty-fourth aspect, in any one of the sixth to eleventh aspects, the cathode gas is disposed on the back side of the separator with respect to the cathode gas flow path, and the cathode gas is supplied to the cathode gas flow path. It further comprises a gas flow path, and a porous portion that is disposed in at least a part of the separator and sends moisture from the cathode gas flow path to the gas flow path.

  In a twenty-fifth aspect of the invention, in any one of the first to eleventh, twenty-third, and twenty-fourth aspects, the cathode gas flow path is configured so that the upstream and the downstream of the cathode gas flow path are close to each other. Features.

  In a twenty-sixth aspect of the invention, in any one of the first to eleventh and twenty-third aspects, the predetermined fiber has a hydrophilic group.

  According to a twenty-seventh aspect, in any one of the first to seventh and twenty-third aspects, an unevenness is provided on a surface of the moisture moving means.

  According to a twenty-eighth aspect, in the twenty-third or twenty-fourth aspect, the predetermined fiber is made of a substance having a higher capillary suction force than the porous portion.

  According to a twenty-ninth aspect, in the twenty-fourth aspect, the moisture moving means is provided on at least a part of an inner wall of the cathode gas flow path.

  According to the first aspect of the present invention, since the moisture moving means made of a predetermined fiber is provided in the vicinity of the cathode gas flow path, the moisture generated by the reaction is caused to flow downstream from the cathode gas flow path by the capillary suction force of the fiber. It becomes possible to move to the upstream side. As a result, it is possible to prevent the movement of oxygen in the cathode gas from being hindered by the moisture accumulated in the flow path, and to increase the efficiency of the fuel cell. Further, since the moisture moved to the upstream side of the cathode gas channel can be supplied into the cathode gas, the cathode gas can be reliably humidified, and the oxygen in the cathode gas can be upstream of the channel. Can be ionized.

  According to 2nd invention, the porosity in a moisture moving means can be raised by using the fiber which has at least 1 recessed part in cross-sectional shape, and a water conveyance path | route can be ensured reliably. Therefore, the moisture generated by the reaction can be reliably moved from the downstream side to the upstream side of the cathode gas flow path. Moreover, the surface area of a fiber is expanded by using the fiber which has at least 1 recessed part, and the quick-drying property of a fiber can be improved. Therefore, the moisture moved along the fibers can be dried and supplied into the cathode gas, and the cathode gas can be reliably humidified.

  According to the third aspect of the invention, the direction of moisture movement can be defined by aligning the extending direction of the fibers in a certain direction. Therefore, by matching the cathode gas flow path with the fiber extending direction, moisture can be reliably moved from the downstream side to the upstream side of the cathode gas flow path.

  According to the fourth aspect of the present invention, the moisture moving means can be made conductive by constituting the moisture moving means from carbon fibers. Therefore, it is possible to provide a moisture transfer means at a portion of the fuel cell where conductivity is required.

  According to the fifth aspect of the present invention, it is possible to move moisture along the cathode gas flow path by providing the moisture moving means on at least a part of the inner wall of the cathode gas flow path.

  According to the sixth aspect of the present invention, the moisture transfer means is disposed in at least one of the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator, so that moisture is transferred along the electrolyte membrane, the catalyst layer, the diffusion layer, and the separator. Can be moved.

  According to the seventh aspect of the invention, the moisture moving means is disposed at the interface of the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator, so that the moisture can be moved along the interface.

  According to the eighth invention, since the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator includes the predetermined fiber that promotes the movement of moisture, the moisture generated by the reaction is moved by the capillary suction force of the fiber. It becomes possible. Therefore, it is possible to move from the downstream side to the upstream side of the cathode gas flow path, and it is possible to prevent the movement of oxygen in the cathode gas from being hindered by moisture accumulated in the flow path. Further, since the moisture moved to the upstream side of the cathode gas channel can be supplied into the cathode gas, the cathode gas can be reliably humidified, and the oxygen in the cathode gas can be upstream of the channel. Can be ionized.

  According to the ninth aspect, by using the fiber having at least one recess in the cross-sectional shape, the porosity around the fiber can be increased, and the water guide path can be ensured reliably. Therefore, the moisture generated by the reaction can be reliably moved from the downstream side to the upstream side of the cathode gas flow path. Moreover, the surface area of a fiber is expanded by using the fiber which has at least 1 recessed part, and the quick-drying property of a fiber can be improved. Therefore, the moisture moved along the fibers can be dried and supplied into the cathode gas, and the cathode gas can be reliably humidified.

  According to the tenth aspect of the invention, the direction of moisture movement can be defined by aligning the extending direction of the fibers in a certain direction. Therefore, by matching the cathode gas flow path with the fiber extending direction, moisture can be reliably moved from the downstream side to the upstream side of the cathode gas flow path.

  According to the eleventh invention, the predetermined fiber is a carbon fiber, so that the fiber can be made conductive. Accordingly, it is possible to ensure the conductivity of the portion where the fiber is disposed.

  According to the twelfth invention, in the thin film for a fuel cell, by extending the fiber having at least one recess in the cross-sectional shape in a predetermined direction, the movement direction of moisture is regulated in the direction in which the fiber extends. be able to. Therefore, by using this fuel cell thin film at a predetermined portion of the fuel cell, it is possible to regulate the direction of moisture movement in the fuel cell.

  According to the thirteenth aspect, by making the predetermined fiber a carbon fiber, the fuel cell thin film can be made conductive. Therefore, the fuel cell thin film can be disposed at a predetermined location of the fuel cell where conductivity is required.

  According to the fourteenth aspect of the present invention, in the fuel cell thin film formed by sticking predetermined fibers, the direction in which the fibers extend is aligned with the predetermined direction, so that the direction of moisture movement in the direction in which the fibers extend Can be regulated. Therefore, by using this fuel cell thin film at a predetermined portion of the fuel cell, it is possible to regulate the direction of moisture movement in the fuel cell.

  According to the fifteenth aspect, by providing at least one concave portion in the cross-sectional shape of the fiber, the porosity around the fiber can be increased, and the water guide path can be reliably ensured.

  According to the sixteenth invention, the predetermined fiber can be made of carbon fiber, whereby the fuel cell thin film can be made conductive. Therefore, the fuel cell thin film can be disposed at a predetermined location of the fuel cell where conductivity is required.

  According to the seventeenth aspect, a carbon fiber having at least one recess in a cross-sectional shape can be formed by extruding a coal-based or petroleum-based pitch from a mold having at least one recess. By forming a thin film for a fuel cell using fibers, it is possible to manufacture a thin film for a fuel cell in which the moisture moving direction is regulated in the direction in which the carbon fiber extends.

  According to the eighteenth invention, a fiber material made of a polymer material is extruded from a mold having at least one recess, whereby a fiber having at least one recess can be formed in a cross-sectional shape. By forming the carbon fiber, the carbon fiber having at least one concave portion in the cross-sectional shape can be formed. By forming a thin film for a fuel cell using this carbon fiber, it is possible to manufacture a thin film for a fuel cell in which the direction of moisture movement is regulated in the direction in which the carbon fiber extends.

  According to the nineteenth aspect, the warp yarn extends direction by weaving warp yarn having at least one recess in the cross-sectional shape and weft yarn not having the recess in the cross-sectional shape to form the fuel cell thin film. In addition, it is possible to manufacture a thin film for a fuel cell in which the moisture moving direction is regulated.

  According to the twentieth aspect of the invention, the fuel cell thin film is produced by gluing the fibers in a state in which the fiber extending directions are aligned, whereby the moisture moving direction is regulated in the fiber extending direction. A thin film can be manufactured.

  According to the twenty-first aspect, it is possible to align the extending direction of the fibers by using the plate material having grooves on the surface and inserting the fibers into the grooves.

  According to the twenty-second aspect, it is possible to align the extending direction of the fibers by applying ultrasonic vibration or mechanical vibration.

  According to the twenty-third aspect, since the porous portion for sending moisture from the cathode gas channel to the gas channel on the back side of the separator is provided, moisture absorbed in the cathode gas channel can be sent to the gas channel. it can. As a result, the cathode gas can be reliably humidified, and a decrease in power generation performance of the fuel cell due to drying of the electrolyte membrane can be reliably suppressed.

  According to the twenty-fourth aspect of the invention, since the porous portion for sending moisture from the cathode gas channel to the gas channel on the back side of the separator is provided, moisture absorbed in the cathode gas channel can be sent to the gas channel. it can. As a result, the cathode gas can be reliably humidified, and a decrease in power generation performance of the fuel cell due to drying of the electrolyte membrane can be reliably suppressed.

  According to the twenty-fifth aspect, since the cathode gas flow path is configured so that the upstream and downstream sides of the cathode gas flow path are adjacent to each other, the water accumulated in the cathode gas flow path can be sent upstream. Thereby, moisture can be uniformly distributed over the entire region from the upstream to the downstream of the flow path of the cathode gas, and the water can be supplied to the entire gas flow path on the back side of the separator. Therefore, it is possible to reliably humidify the cathode gas flowing through the gas flow path on the back side of the separator.

  According to the twenty-sixth aspect, since the predetermined fiber has a hydrophilic group, the cathode gas flow path can be always moistened with moisture. This makes it possible to continuously and reliably humidify the cathode gas.

  According to the twenty-seventh aspect, since the unevenness is provided on the surface of the moisture moving means, moisture can be absorbed from a wider range, and the cathode gas can be reliably humidified.

  According to the twenty-eighth aspect, since the predetermined fiber is made of a substance having a higher capillary suction force than the porous portion, it becomes easy to take moisture into the predetermined fiber, and more water is removed from the gas on the back side of the separator. It becomes possible to supply to the flow path.

  According to the twenty-ninth aspect, since the moisture moving means is provided on at least a part of the inner wall of the cathode gas flow path, it is possible to move the moisture along the cathode gas flow path.

  Several embodiments of the present invention will be described below with reference to the drawings. In addition, the same code | symbol is attached | subjected to the element which is common in each figure, and the overlapping description is abbreviate | omitted. The present invention is not limited to the following embodiments.

Embodiment 1 FIG.
FIG. 1 is an exploded perspective view showing a configuration of a fuel cell 10 according to Embodiment 1 of the present invention. The fuel cell 10 may be of a type that generates water (water vapor) when generating electric power, and here, a solid polymer type (PEM) fuel cell is exemplified. FIG. 1 shows one of a plurality of unit cells constituting the fuel cell 10, and the fuel cell 10 is configured by stacking unit cells in the direction of the arrow in FIG.

  FIG. 2 is a schematic diagram showing a cross section of the unit cell along the stacking direction. The unit cell includes an electrolyte membrane 12, a catalyst layer 14, a diffusion layer 16, and separators 18 and 19 disposed on both sides of the electrolyte membrane 12. 1 and 2, the separator 18 is disposed on the anode side, and the separator 19 is disposed on the cathode side.

  The electrolyte membrane 12 is a proton conductive ion exchange membrane formed of a solid polymer material such as a fluorine-based resin. The catalyst layer 14 is formed by applying a carbon paste carrying platinum (Pt) to the surface of the electrolyte membrane 12. The diffusion layer 16 is formed of carbon cloth woven from carbon fibers, or paper made of carbon fibers or carbon paste. The separators 18 and 19 are formed of a gas-impermeable conductive member such as dense carbon which is compressed by carbon and impermeable to gas.

  The separator 18 is provided with a flow path 20 for anode gas (hydrogen gas) on the surface facing the diffusion layer 16. As shown in FIG. 1, an anode gas inlet 26 is provided at one end of the flow path 20 and an outlet 28 is provided at the other end.

  The separator 19 is provided with a cathode gas (oxygen gas) flow path 22 on the surface facing the diffusion layer 16. As shown in FIG. 1, a cathode gas inlet 30 is provided at one end of the flow path 22, and an outlet 32 is provided at the other end. Further, as shown in FIG. 2, the separator 19 is provided with a coolant flow path 24.

  As shown in FIG. 1, the anode gas flow path 20 and the cathode gas flow path 22 both extend in a plane perpendicular to the stacking direction of the unit cells, and are provided in a meandering shape in the plane. When the anode gas is supplied to the flow path 20, hydrogen in the anode gas is ionized in the process of passing through the diffusion layer 16 and the catalyst layer 14 to become hydrogen ions. Similarly, when the cathode gas is supplied to the flow path 22, oxygen in the cathode gas is ionized in the process of passing through the diffusion layer 16 and the catalyst layer 14 to become oxygen ions.

When these hydrogen ions and oxygen ions are supplied to the electrolyte membrane 12, electric power is generated by a reaction in the electrolyte membrane 12. At the same time, water is generated from the hydrogen ions and oxygen ions on the cathode side ((1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O). Most of this water absorbs the heat generated in the fuel cell 10 and is generated as water vapor.

  Moisture generated on the cathode side is contained in the cathode gas in the flow path 22 and flows downstream due to the flow of the cathode gas, so that water may accumulate downstream of the flow path 22. FIG. 3A is a schematic diagram for explaining a state where moisture is accumulated downstream of the flow path 22. If moisture accumulates downstream of the flow path 22, the surface of the diffusion layer 16 is covered with water, and a sufficient amount of oxygen is not supplied to the electrolyte membrane 12. For this reason, the reaction in the electrolyte membrane 12 may decrease, and the efficiency of the fuel cell 10 may decrease.

  In addition, when moisture generated on the cathode side is accumulated downstream of the flow path 22, moisture is not supplied to the cathode gas on the upstream side of the flow path 22, so that the cathode gas flowing upstream of the flow path 22 is dried. . For this reason, oxygen in the cathode gas is not sufficiently ionized, and the reaction at the electrolyte membrane 12 may be reduced.

  For this reason, in this embodiment, as shown in FIG. 2, the moisture movement promoting film 34 is provided so as to cover the inner wall surface of the flow path 22. The moisture movement promoting film 34 is a cloth (paper) or paper (paper) made of a fiber material, and is adhered to the entire inner wall of the flow path 22. Since the fiber material generates a capillary suction force and has high water absorption, the moisture can be moved within the moisture movement promoting film 34 by the capillary suction force as shown in FIG. Moisture accumulated in can be sent upstream. Accordingly, it is possible to prevent the surface of the diffusion layer 16 from being covered with water on the downstream side of the flow path 22, and it is possible to suppress a decrease in the efficiency of the fuel cell 10. Further, since the moisture movement promoting film 34 made of the fiber material is easy to dry and has a quick drying property, the moisture absorbed by the moisture movement promoting film 34 is dried in a short time, and the dried moisture is in the cathode gas. Supplied as water vapor. Therefore, moisture that has moved to the upstream side of the flow path 22 is dried, so that supply of moisture into the cathode gas is promoted on the upstream side. As a result, the cathode gas can be sufficiently humidified on the upstream side of the flow path 22 and the ionization of oxygen on the upstream side is promoted, so that the efficiency of the fuel cell 10 can be increased.

  In order to increase the capillary suction force, the moisture movement promoting film 34 is preferably composed of fibers 36 having an irregular cross-sectional shape. FIG. 4 is a schematic diagram showing the fiber 36 having an irregular cross-sectional shape, and shows a cross-sectional shape along a direction orthogonal to the longitudinal direction of the fiber 36. As shown in FIG. 4, the fiber 36 has at least one recess 38 in its cross-sectional shape. In the following description, the fiber 36 in which the recess 38 is formed in the cross-sectional shape will be referred to as a fiber 36 having an irregular cross-sectional shape. The cross-sectional shape of the fiber 36 may be variable in the longitudinal direction.

  FIG. 5 is a schematic diagram showing a state in which a plurality of fibers 36 are bundled. Since the fiber 36 has an irregular cross-sectional shape, as shown in FIG. 5, when a plurality of fibers 36 are bundled, many void regions are generated. Therefore, according to such a fiber 36, since the porosity when bundled is high, many water conduits are formed. For this reason, the capillary suction force of the moisture movement promoting film 34 composed of the fibers 36 becomes very large, and the moisture can be reliably moved in the longitudinal direction of the fibers 36. Therefore, by forming the moisture movement promoting film 34 with such fibers 36, the moisture accumulated downstream of the flow path 22 can be reliably sent to the upstream side in a short time. In the present embodiment, since the flow path 22 is meandering, the distance between the upstream and downstream of the flow path 22 can be shortened, and the moisture movement from the downstream to the upstream can be performed in a shorter time. is there.

  Further, the fiber 36 having an irregular cross-sectional shape has a higher surface area due to the concave portion 38 than a fiber having a normal cross-sectional shape (circular, square, etc.), so that quick drying is further enhanced. Therefore, water supply into the cathode gas can be further promoted on the upstream side of the flow path 22. As a result, the cathode gas can be sufficiently humidified on the upstream side of the flow path 22, and the ionization of oxygen is promoted on the upstream side, so that the efficiency of the fuel cell 10 can be increased.

  In the above-described example, the moisture movement promoting film 34 is provided on the entire inner wall of the flow path 22, but the moisture movement promoting film 34 may be provided only on a part of the surface.

  As described above, according to the first embodiment, since the moisture movement promotion film 34 is provided in the cathode gas flow path 22 on the cathode side of the unit cell of the fuel cell 10, it is generated by the reaction in the electrolyte membrane 12. It is possible to move the moisture from the downstream side of the flow path 22 to the upstream side. Thereby, the surface of the diffusion layer 16 is not covered with moisture downstream of the flow path 22, and it is possible to prevent the supply of oxygen to the electrolyte membrane 12 from being hindered. Accordingly, oxygen can be reliably supplied to the electrolyte membrane 12 on the downstream side of the flow path 22, and the efficiency of the fuel cell 10 can be increased.

  In addition, since the moisture movement promoting film 34 has high quick-drying properties, the moisture moved to the upstream side of the flow path 22 can be dried in a short time and supplied to the cathode gas. Therefore, the cathode gas can be reliably humidified on the upstream side of the flow path 22, and ionization of oxygen in the cathode gas can be promoted on the upstream side. Thereby, the efficiency of the fuel cell 10 can be increased. Further, since the humidifier for humidifying the cathode gas can be reduced by promoting the humidification on the upstream side, it is possible to reduce the size of the fuel cell system.

Embodiment 2. FIG.
Next, a second embodiment of the present invention will be described. In the first embodiment, the moisture movement promoting film 34 is provided on the inner wall of the flow path 22, but in the second embodiment, the moisture movement promoting film 34 is provided in another part of the unit cell.

  FIG. 6 is a schematic view showing an example in which a moisture movement promoting film 34 is provided between the diffusion layer 16 and the catalyst layer 14, and is a schematic view showing a cross section along the stacking direction of the unit cells as in FIG. 2. is there. As described in the first embodiment, the moisture movement promoting film 34 absorbs moisture by the capillary suction force and moves it, and also has excellent quick drying properties. In the unit cell, the moisture generated at the cathode can move in the stacking direction of the unit cell between the electrolyte membrane 12 and the separator 19, so that the moisture downstream of the flow path 22 flows into the diffusion layer 16 and the catalyst layer 14. It is sent to the upstream side of the flow path 22 by the capillary suction force of the moisture movement promoting film 34 disposed between them. Therefore, even when the moisture movement promoting film 34 is provided between the diffusion layer 16 and the catalyst layer 14, it is possible to move the moisture on the downstream side of the flow path 22 to the upstream side.

  When the moisture movement promoting film 34 is inserted between the diffusion layer 16 and the catalyst layer 14, electrons pass through these regions. Therefore, preferably, the fibers constituting the moisture movement promoting film 34 are made of conductive such as carbon fibers. It is desirable that the material is made of a functional material. In addition, in order to ensure conductivity, the moisture movement promoting film 34 may be configured using a fine metal wire, or a fiber coated with metal or carbon. Further, in order to enhance the capillary suction force (water absorption) and quick drying property of the moisture movement promoting film 34, the moisture movement promoting film 34 is configured using the fibers 36 having the irregular cross-sectional shape described in the first embodiment. Is preferred. A method for manufacturing the fiber 36 having an irregular cross-sectional shape from the carbon fiber will be described in the fourth embodiment.

  On the other hand, when the moisture movement promoting film 34 is composed of a fiber material having low conductivity, as shown in FIG. 7, the distance between adjacent fiber materials is increased to configure the moisture movement promoting film 34 in a mesh shape. Is desirable. As a result, it is possible to minimize the decrease in conductivity due to the insertion of the moisture movement promoting film 34 and the obstruction factors for the movement of oxygen and hydrogen.

  The same effect can be obtained when the moisture movement promoting film 34 is inserted in a region other than the region between the diffusion layer 16 and the catalyst layer 14. For example, even when the moisture movement promoting film 34 is inserted between the catalyst layer 14 and the electrolyte membrane 12, the moisture on the downstream side of the flow path 22 can be moved to the upstream side. Further, the same effect can be obtained even if the moisture movement promoting film 34 is inserted into the separator 19, the diffusion layer 16, the catalyst layer 14, and the electrolyte membrane 12.

Embodiment 3 FIG.
Next, a third embodiment of the present invention will be described. In the first and second embodiments, the moisture migration promoting film 34 is inserted into a predetermined part of the unit cell. However, in the third embodiment, each layer constituting the unit cell is a fiber having an irregular cross-sectional shape described in the first embodiment. 36.

  As described in the first embodiment, the diffusion layer 16 is usually formed as cloth or paper. These normal diffusion layers 16 contain carbon fibers and carbon paste. In the third embodiment, the carbon fiber used for the diffusion layer 16 is formed into a fiber 36 having an irregular cross-sectional shape, and the diffusion layer 16 is formed by mixing with the carbon paste.

  As described in the first embodiment, the fiber 36 having an irregular cross-sectional shape is very excellent in water absorption and quick drying. Therefore, by constituting the diffusion layer 16 with the fibers 36 having an irregular cross-sectional shape, moisture can be moved from the downstream side to the upstream side of the adjacent flow path 22 by the capillary suction force of the diffusion layer 16. The cathode gas can be humidified.

  Since the diffusion layer 16 includes a conductive carbon paste in addition to the fibers 36, the fibers 36 having an irregular cross-sectional shape may not have conductivity, but preferably have conductivity. It is desirable to use carbon fiber or the like. A method for manufacturing the fiber 36 having an irregular cross-sectional shape from the carbon fiber will be described in a fourth embodiment.

  Further, when the fiber 36 is made of a material having low conductivity, only the vicinity of the flow path 22 in the diffusion layer 16 may be made of the fiber 36 and the other region may be made of normal carbon fiber. Thereby, the fall of the electrical conductivity of the diffusion layer 16 can be suppressed to the minimum.

  The catalyst layer 14 or the electrolyte membrane 12 usually does not contain a fiber material. However, the catalyst layer 14 or the electrolyte membrane 12 contains a fiber material, so that the catalyst layer 14 can absorb water and quickly dry due to the water absorption and quick drying properties of the fiber material. Alternatively, moisture can be moved inside the electrolyte membrane 12, moisture downstream of the flow path 22 can be moved upstream, and the cathode gas can be humidified upstream of the flow path 22. When the fiber material is included in the catalyst layer 14, the fiber material can be included by mixing the carbon paste and the fiber material constituting the catalyst layer 14. Also in this case, it is preferable to use a fiber 36 having an irregular cross-sectional shape as a fiber material, and it is more preferable to use a carbon fiber 36 having an irregular cross-sectional shape.

  FIG. 8 is a schematic diagram showing an example in which a part of the separator 19 is made of a fiber material. The separator 19 shown in FIG. 8 is formed by sandwiching a plate 19b formed of a fiber material between two carbon plates 19a and 19c. Since the separator 19 can also be comprised from a metal, you may comprise the separator 19 by inserting the board 19b formed from the fiber raw material between two metal plates.

  As shown in FIG. 8, the plate 19 b formed from the fiber material constitutes a part of the inner wall of the flow path 22. Accordingly, moisture can be moved from the downstream side of the flow path 22 to the upstream side by the capillary suction force of the fiber material, and the cathode gas can be humidified upstream of the flow path 22.

  And the water absorption and quick-drying property can be improved more by using the fiber 36 of irregular cross-sectional shape as a fiber raw material which comprises the board 19b. Therefore, it is preferable to use the fiber 36 having an irregular cross-sectional shape as the fiber material.

  In FIG. 8, since the plate 19b is disposed only in the vicinity of the flow path 22, electrons can freely move in the separators 19a and 19c. Therefore, although the fiber material which comprises the board 19b does not need to have electroconductivity, it is desirable to use the carbon fiber etc. with electroconductivity suitably. A method for manufacturing the fiber 36 having an irregular cross-sectional shape from the carbon fiber will be described in a fourth embodiment.

Embodiment 4 FIG.
Next, a fourth embodiment of the present invention will be described. The fourth embodiment relates to a method for manufacturing the fiber 36 having the irregular cross-sectional shape described in the first embodiment from carbon. As a method of forming the fiber 36 having an irregular cross-sectional shape from carbon, there are a method of manufacturing from a pitch system and a method of manufacturing from a fiber system.

  FIG. 9 is a schematic view showing an apparatus 40 for producing the carbon fiber 36 having an irregular cross-sectional shape. As shown in FIG. 9, the device 40 includes a cylinder 42, a pressure piston 44, and an extrusion hole 46. The shape of the extrusion hole 46 is, for example, the same as the cross-sectional shape shown in FIG. A pressure piston 44 is inserted into the cylinder 42.

  When the carbon fiber 36 having an irregular cross-sectional shape is manufactured using a manufacturing method using a pitch system, the coal 42 or the petroleum pitch that is melted is filled into the cylinder 42. In the state shown in FIG. 9, when the pressure piston 44 is pushed down, the coal pitch or the petroleum pitch is pushed out following the shape of the push-out hole 46. Then, the extruded carbon pitch or petroleum pitch is heated in an oxidizing atmosphere, subjected to an infusibilization treatment, and further heated in an inert gas phase atmosphere to produce a carbon fiber 36 having an irregular cross-sectional shape. it can.

  When the carbon fiber 36 having an irregular cross-sectional shape is manufactured using a manufacturing method using a fiber system, the cylinder 42 is filled with a fiber material made of a polymer material such as rayon or polyacrylonitrile. Then, a fiber 36 such as rayon or polyacrylonitrile having an irregular cross-sectional shape is manufactured by pushing down the pressure piston 44. Thereafter, the fiber 36 such as rayon or polyacrylonitrile is heated in an oxidizing atmosphere to perform infusibilization. Further, heating in an inert gas phase atmosphere and carbonization treatment are performed to release oxygen and hydrogen in the fiber 36. Thereby, the carbon fiber 36 of an irregular cross-sectional shape can be manufactured.

  As described above, according to the fourth embodiment, the fiber 36 having an irregular cross-sectional shape can be manufactured from carbon. Therefore, in the first and second embodiments, the moisture movement promoting film 34 can be manufactured from the carbon fiber 36. In the third embodiment, the electrolyte membrane 12, the catalyst layer 14, the diffusion layer 16 or the separator 19 can be manufactured using the carbon fiber 36 having an irregular cross-sectional shape.

Embodiment 5 FIG.
Next, a fifth embodiment of the present invention will be described. In the fifth embodiment, when a cross (a thin film for a fuel cell) is formed using fibers 36 having an irregular cross-sectional shape, the moisture moving direction is a constant direction.

  FIG. 10 shows a state where the warp yarn is an irregular cross-sectional shape fiber 36 and the weft yarn is a normal cross-sectional shape fiber when a cross is formed using the irregular cross-sectional shape fiber 36 described in the first embodiment. Is shown.

  In this way, moisture can be moved in the direction of the fiber 36 by using only one of the warp and weft constituting the cloth as the fiber 36 having an irregular cross-sectional shape. Therefore, according to this embodiment, the moving direction of moisture can be defined in a specific direction.

  Then, the moisture movement promotion film 34 in the first and second embodiments is configured using such a cloth, and such a cloth is inserted into the separator 19, the diffusion layer 16, the catalyst layer 14, and the electrolyte film 12. By doing so, it becomes possible to move moisture in the direction of the fiber 36 (warp yarn) having an irregular cross-sectional shape. Therefore, by making the direction of the flow path 22 coincide with the direction of the fibers 36, it is possible to reliably move moisture from the downstream side of the flow path 22 to the upstream side. In order to improve conductivity, it is preferable that the warp fibers 36 and the wefts be carbon fibers. Further, when a cloth is manufactured using a fiber material as a carbon fiber, the fiber material may be converted into a carbon fiber by performing a carbonization treatment after preparing the cloth by aligning the direction of the fiber material.

Embodiment 6 FIG.
Next, a sixth embodiment of the present invention will be described. In the sixth embodiment, when a paper (a thin film for a fuel cell) is formed from a fiber material, the longitudinal direction of the fiber material is aligned in a certain direction.

  When a paper is manufactured using a fiber material by a normal method, the directions of the fiber material are randomly arranged as shown in FIG. In the present embodiment, as shown in FIG. 11B, the paper is formed by aligning the directions of the fiber materials. Thereby, it becomes possible to move moisture reliably in the longitudinal direction of the fiber material.

  In paper with aligned fiber materials, a water guide path is formed in the longitudinal direction of the fiber material, so even if the cross-sectional shape of the fiber material is a normal shape, moisture can be moved along the direction of the fiber material. it can. In order to move moisture more reliably, it is desirable to use a fiber 36 having an irregular cross-sectional shape with a high capillary suction as a fiber material.

  Then, using such paper, the moisture movement promoting film 34 in the first and second embodiments is configured, and such paper is placed inside the separator 19, the diffusion layer 16, the catalyst layer 14, and the electrolyte film 12. By inserting, it becomes possible to move moisture along the direction of the fiber material in the paper. Therefore, by making the direction of the flow path 22 coincide with the direction of the fiber material, it is possible to reliably move moisture from the downstream side of the flow path 22 toward the upstream side. In order to improve the conductivity, the fiber material is preferably carbon fiber.

  FIG. 12 is a schematic view showing a method for producing the paper shown in FIG. As shown in FIG. 12, a groove 50a is formed in a slat plate 50 for manufacturing paper. Then, by arranging the fiber material in the direction of the groove 50a and sticking the fiber material, a paper in which the fiber material is arranged in a certain direction can be manufactured. Moreover, the fiber material may be arranged in a certain direction by providing a cloth in which the fiber direction is arranged on the plow plate 50.

  FIG. 13 is a schematic view showing another method for producing the paper shown in FIG. In FIG. 13, an ultrasonic or mechanical vibrator 52 is connected to the gap plate 50. According to the configuration of FIG. 13, it is possible to align the direction of the fiber material by placing the fiber material on the slat plate 50 and vibrating the slat plate 50 with the vibrator 52. After aligning the direction of the fiber material, paper is produced by gluing the fiber material.

  Moreover, when manufacturing paper using a fiber material as a carbon fiber, after preparing a paper by arranging the direction of a fiber material, it is good also considering a fiber material as a carbon fiber by giving a carbonization process.

Embodiment 7 FIG.
Next, a seventh embodiment of the present invention will be described. FIG. 14 is an exploded perspective view showing the configuration of the fuel cell 10 according to the seventh embodiment. FIG. 14 shows one of a plurality of unit cells constituting the fuel cell 10, and the fuel cell 10 is configured by stacking unit cells in the direction of the arrow in FIG.

  FIG. 15 is a schematic diagram showing a cross section of a unit cell along the stacking direction. The unit cell includes an electrolyte membrane 12, a catalyst layer 14, a diffusion layer 16, and separators 18 and 19 disposed on both sides of the electrolyte membrane 12. 14 and 15, the separator 18 is disposed on the anode side, and the separator 19 is disposed on the cathode side. The configurations of the electrolyte membrane 12, the catalyst layer 14, and the diffusion layer 16 are the same as those in the first embodiment.

  As shown in FIG. 15, in the fuel cell 10 of the seventh embodiment, a cathode gas flow path 60 is provided on the back side of the flow path 22, that is, on the opposite side of the flow path 22 from the electrolyte membrane 12. . As shown in FIG. 14, the flow path 60 is connected to the flow path 22 in a chamber portion 66 formed at one end of the fuel cell 10. The cathode gas flowing through the flow path 60 is collected in the chamber section 66 and sent from the chamber section 66 to each of the flow paths 22.

  A porous body 62 is provided between the flow path 22 and the flow path 60 in the stacking direction of the unit cells. The porous body 62 constitutes a part of the separator 19, and the flow path 22 is a part of the porous body 62. The porous body 62 is made of a porous material and includes a large number of fine holes through which moisture can permeate.

  As described in the first embodiment, moisture is generated at the cathode along with the reaction in the fuel cell 10, and the moisture stays in the flow path 22. The fuel cell 10 according to the seventh embodiment causes the moisture in the flow path 22 to permeate through the micropores of the porous body 62 by the capillary suction force by flowing the pressurized cathode gas through the flow path 60. send. The moisture that has permeated through the porous body 62 is vaporized by the heat of the cathode gas flowing through the flow path 60. At this time, heat of vaporization is taken from the cathode gas, the separator 19 is cooled, and the cathode gas is heated. As a result, the cathode gas can be reliably humidified before being sent to the flow path 22 that is the reaction flow path, and at the same time, the cooling efficiency of the separator 19 can be increased. Therefore, the efficiency of supplying ions to the electrolyte membrane 12 can be increased, and the reaction efficiency can be increased.

  As shown in FIG. 15, a moisture diffusion film 64 is arranged in the flow path 22 so as to cover the inner wall surface. The moisture diffusing film 64 is composed of fibers (fast-drying fibers) with improved capillary suction force, and is composed of the fibers 36 described in the first embodiment, for example.

  Moisture generated by the reaction moves from the electrolyte membrane 12 to the catalyst layer 14 and the diffusion layer 16, spreads on the moisture diffusion film 64 in the flow path 22, and is dispersed on the inner wall surface of the flow path 22. The water dispersed on the inner wall surface of the flow path 22 passes through the micropores of the porous body 62 and is sent to the flow path 60. Therefore, by disposing the moisture diffusion film 64 on the inner wall surface of the flow path 22, the contact area between the porous body 62 and the water can be expanded, and the water absorbed from a wider range can be sent to the flow path 60. . Thereby, the cathode gas flowing through the flow path 60 can be reliably humidified.

  In order to further increase the surface area of the moisture diffusion film 64, it is preferable to form irregularities on the surface of the moisture diffusion film 64. Thereby, moisture absorbed from a wider range can be sent to the flow path 60, and the cathode gas flowing through the flow path 60 can be reliably humidified.

  In addition, since the moisture diffusing film 64 is disposed in the entire region from the upstream to the downstream of the flow path 22, the moisture can be quickly moved in the entire area from the upstream to the downstream of the flow path 22. Concentration on a specific part can be suppressed.

  In particular, moisture can be moved along the direction of the flow path 22 by making the direction in which the fibers constituting the moisture diffusion film 64 extend coincide with the direction of the flow path 22. In this case, since the moisture can flow along the direction in which the fibers extend regardless of the cross-sectional shape of the fibers constituting the moisture diffusion film 64, the fibers constituting the moisture diffusion film 64 are indefinite. Instead of using a fiber having a cross-sectional shape, a fiber having a normal cross-sectional shape may be used. Thereby, moisture can be uniformly distributed over the entire region from the upstream side to the downstream side of the flow path 22.

  As described in the first embodiment, the moisture generated by the reaction of the fuel cell 10 tends to accumulate on the downstream side of the flow path 22. Since the flow path 60 is folded back at the chamber portion 66 at the end of the fuel cell 10 and connected to the flow path 22, moisture accumulated downstream of the flow path 22 passes through the porous body 62 and reaches the flow path 60. Then, the moisture reaches the upstream of the flow path 60. The cathode gas flowing in the flow path 60 is gradually heated by the heat of the fuel cell 10 as it moves to the downstream side of the flow path 60, so that when moisture is supplied upstream of the flow path 60, the downstream side Compared to the above, moisture is supplied to the cathode gas in a low temperature state. In this case, the moisture supplied to the upstream of the flow path 60 does not evaporate sufficiently, so that the humidification of the cathode gas may be insufficient.

  In the seventh embodiment, since the moisture diffusion film 64 is disposed in the entire region from the upstream to the downstream of the flow path 22, the water generated by the reaction can be uniformly distributed in the flow path 22. Therefore, it is possible to supply a sufficient amount of moisture to the upstream side of the flow path 60 where the temperature of the cathode gas is high, and it is possible to reliably humidify the cathode gas.

  In the above-described aspect, the moisture diffusion film 64 is disposed on the inner wall surface of the flow path 22, but the fiber itself that does not constitute the film, for example, the fiber 36 itself described in the first embodiment is used as the inner wall surface of the flow path 22. You may arrange in.

  Moreover, even if the moisture diffusion membrane 64 (or the fiber constituting the same) is inserted between the catalyst layer 14 and the diffusion layer 16 or between the electrolyte membrane 12 and the catalyst layer 14 by the same method as in the second embodiment. Alternatively, a moisture diffusion film 64 (or a fiber constituting the same) may be inserted into the separator 19, the diffusion layer 16, the catalyst layer 14, and the electrolyte membrane 12. Further, the electrolyte membrane 12, the catalyst layer 14, the diffusion layer 16, and the separator 19 may be constituted by the moisture diffusion membrane 64 (or a fiber constituting the same) in the same manner as in the third embodiment. Also with these configurations, moisture can be dispersed throughout the entire area of the flow path 22 from the upstream side to the downstream side, and the same effect as described above can be obtained.

  As described above, according to the seventh embodiment, in the fuel cell 10 in which the flow path 60 is provided so as to face the cathode gas flow path 22 and the porous body 62 is provided between the flow path 22 and the flow path 60. Since the moisture diffusion film 64 made of fibers with improved capillary suction force is disposed on the inner wall surface of the flow path 22, the water can be evenly dispersed throughout the flow path 22. Therefore, it is possible to uniformly supply the water that has permeated through the porous body 62 from the upstream side to the downstream side of the flow path 60. Thereby, the cathode gas can be reliably humidified, and the reaction efficiency in the electrolyte membrane 12 can be improved.

Embodiment 8 FIG.
Next, an eighth embodiment of the present invention will be described. The basic configuration of the eighth embodiment is the same as that of the seventh embodiment. In the eighth embodiment, instead of the moisture diffusing film 64 of the seventh embodiment, a superabsorbent film composed of fibers with improved hydrophilicity is arranged.

  When water is supplied to the flow path 60 through the porous body 62 from the flow path 22, it is preferable that the inner wall surface of the flow path 22 is always moistened with water. This is because once the inner wall surface of the flow path 22 is dried, a certain amount of time is required to allow moisture to permeate the porous body 62 again.

  By disposing the superabsorbent film on the inner wall surface of the flow path 22, it becomes possible to always moisten the inner wall surface of the flow path 22 with moisture. Thereby, it becomes possible to always supply moisture to the flow path 60 via the porous body 62, and it is possible to continuously and reliably humidify the cathode gas. Further, by arranging the highly water-absorbing film on the entire inner wall surface of the flow path 22, the contact area between the porous body 62 and the water can be expanded, and the water absorbed from a wider range is sent to the flow path 60. Can do.

  Similar to Embodiment 7, in order to further increase the surface area of the superabsorbent film, it is preferable to form irregularities on the surface of the superabsorbent film. Thereby, moisture absorbed from a wider range can be sent to the flow path 60, and the cathode gas flowing through the flow path 60 can be reliably humidified.

  As the fiber having improved hydrophilicity, for example, a fiber having a hydrophilic group such as a hydroxyl group or a sulfone group is suitable. Further, by making the direction in which the fibers extend coincide with the direction in which the flow path 22 extends, it becomes possible to uniformly distribute moisture from the upstream side of the flow path 22 to the entire downstream area. Thus, as in the seventh embodiment, a sufficient amount of moisture can be supplied to the upstream side of the flow path 60, and the cathode gas can be reliably humidified.

  As described above, according to the eighth embodiment, since the superabsorbent film composed of fibers with improved hydrophilicity is disposed on the inner wall surface of the flow path 22, the inner wall surface of the flow path 22 is always moistened with moisture. It is possible to keep it. Thereby, it becomes possible to always supply moisture to the flow path 60 via the porous body 62, and it is possible to continuously and reliably humidify the cathode gas.

  As in the seventh embodiment, the fiber itself with improved hydrophilicity may be disposed on the inner wall surface of the flow path 22. Further, even if a superabsorbent membrane (or a fiber constituting the same) is inserted between the catalyst layer 14 and the diffusion layer 16 or between the electrolyte membrane 12 and the catalyst layer 14 by the same method as in the second embodiment. Alternatively, a superabsorbent membrane (or a fiber constituting the same) may be inserted into the separator 19, the diffusion layer 16, the catalyst layer 14, and the electrolyte membrane 12. Further, the electrolyte membrane 12, the catalyst layer 14, the diffusion layer 16, and the separator 19 may be constituted by a highly water-absorbing membrane (or fibers constituting the same) in the same manner as in the third embodiment.

Embodiment 9 FIG.
Next, a ninth embodiment of the present invention will be described. The basic configuration of the ninth embodiment is the same as that of the seventh embodiment. In the ninth embodiment, in the fuel cell 10 of the seventh embodiment, the upstream and downstream of the flow path 22 are brought close to each other so that the water accumulated on the downstream side is moved to the upstream side.

  FIG. 16 is a plan view showing the configuration of the porous body 62 and the flow path 22 of the separator 19 arranged on the cathode side. As shown in FIG. 16, in the ninth embodiment, the upstream and downstream of the flow path 22 are brought close to each other. Thereby, it is possible to send the moisture accumulated downstream of the flow path 22 through the fine holes of the porous body 62 to the upstream.

  As described above, according to the ninth embodiment, in the fuel cell 10 in which the channel 60 is provided so as to face the cathode gas channel 22 and the porous body 62 is provided between the channel 22 and the channel 60. Since the upstream side and the downstream side of the flow path 22 are close to each other, the water accumulated downstream of the flow path 22 can be sent upstream. Thereby, moisture can be uniformly distributed over the entire region from the upstream side to the downstream side of the flow channel 22, and the water can be supplied to the entire region of the flow channel 60. Therefore, it is possible to reliably humidify the cathode gas flowing through the flow path 60.

1 is an exploded perspective view showing a configuration of a fuel cell according to Embodiment 1 of the present invention. It is a schematic diagram which shows the cross section of the unit cell along the lamination direction. It is a schematic diagram which shows the state which the water | moisture content collected downstream of the flow path of cathode gas, and the state which moved the downstream water | moisture content upstream. It is a schematic diagram which shows the fiber which has an amorphous cross-sectional shape. It is a schematic diagram which shows the state which bundled the fiber shown in FIG. It is a schematic diagram which shows the example which provided the moisture movement promotion film | membrane between the diffusion layer and the catalyst layer. It is a schematic diagram which shows the example which comprised the moisture movement promotion film | membrane in mesh shape. It is a schematic diagram which shows the example which comprised a part of separator from the fiber raw material. It is a schematic diagram which shows the apparatus for manufacturing the carbon fiber which has an amorphous cross-sectional shape. It is a schematic diagram showing a thin film for a fuel cell in which warp yarns are fibers having an irregular cross-sectional shape and weft yarns are fibers having a normal cross-sectional shape. It is a schematic diagram which shows the paper which aligned the direction of the fiber. It is a schematic diagram which shows the method of manufacturing the paper shown in FIG.11 (b). It is a schematic diagram which shows the other method of manufacturing the paper shown in FIG.11 (b). FIG. 10 is an exploded perspective view showing a configuration of a fuel cell according to Embodiment 7. In the fuel cell of FIG. 14, it is a schematic diagram which shows the cross section of the unit cell along the lamination direction. FIG. 38 is a plan view showing a configuration of a separator porous body and flow paths in a ninth embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Fuel cell 12 Electrolyte membrane 14 Catalyst layer 16 Diffusion layer 18, 19 Separator 22 Cathode gas flow path 34 Moisture transfer promotion membrane 36 Fiber of irregular cross section 38 Recess 40 Carbon fiber manufacturing device 46 Extrusion hole 50 Slip plate 52 Vibration Child 60 channel 62 porous body 64 moisture diffusion film

Claims (29)

A fuel cell that receives supply of an anode gas containing hydrogen to an anode and a cathode gas containing oxygen to a cathode to generate electric power,
A fuel cell comprising a moisture moving means comprising a predetermined fiber in the vicinity of the cathode gas flow path.   2. The fuel cell according to claim 1, wherein the predetermined fiber has at least one recess in its cross-sectional shape.   The fuel cell according to claim 1 or 2, wherein a direction in which the predetermined fibers extend is aligned in a certain direction.   The fuel cell according to claim 1, wherein the predetermined fiber is a carbon fiber.   The fuel cell according to any one of claims 1 to 4, wherein the moisture moving means is provided on at least a part of an inner wall of the cathode gas flow path. An electrolyte membrane for reacting hydrogen in the anode gas with oxygen in the cathode gas;
A catalyst layer provided on the electrolyte membrane;
A diffusion layer provided on the catalyst layer;
A separator provided on the diffusion layer and provided with a flow path for the cathode gas;
The fuel cell according to any one of claims 1 to 4, wherein the moisture moving means is disposed in at least one of the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator. An electrolyte membrane for reacting hydrogen in the anode gas with oxygen in the cathode gas;
A catalyst layer provided on the electrolyte membrane;
A diffusion layer provided on the catalyst layer;
A separator provided on the diffusion layer and provided with a flow path for the cathode gas;
The fuel cell according to any one of claims 1 to 4, wherein the moisture transfer means is disposed at an interface of the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator. A fuel cell that receives supply of an anode gas containing hydrogen to an anode and a cathode gas containing oxygen to a cathode to generate electric power,
An electrolyte membrane for reacting hydrogen in the anode gas with oxygen in the cathode gas;
A catalyst layer provided on the electrolyte membrane;
A diffusion layer provided on the catalyst layer;
A separator provided on the diffusion layer and provided with a flow path for the cathode gas;
The fuel cell according to claim 1, wherein the electrolyte membrane, the catalyst layer, the diffusion layer, or the separator includes a predetermined fiber that promotes moisture movement.   9. The fuel cell according to claim 8, wherein the predetermined fiber has at least one recess in its cross-sectional shape.   The fuel cell according to claim 8 or 9, wherein a direction in which the predetermined fibers extend is aligned in a certain direction.   The fuel cell according to claim 8, wherein the predetermined fiber is a carbon fiber. A thin film for a fuel cell,
Formed by weaving predetermined fibers,
A fuel cell thin film characterized in that only fibers extending in a predetermined direction have at least one recess in its cross-sectional shape.   The thin film for a fuel cell according to claim 12, wherein the predetermined fiber is a carbon fiber. A thin film for a fuel cell,
It is formed by gluing predetermined fibers,
A thin film for a fuel cell, wherein the extending direction of the fibers is aligned in a predetermined direction.   15. The thin film for a fuel cell according to claim 14, wherein the predetermined fiber has at least one recess in its cross-sectional shape.   16. The fuel cell thin film according to claim 14, wherein the predetermined fiber is a carbon fiber. A method for producing a thin film for a fuel cell, comprising:
Extruding a coal-based or petroleum-based pitch from a mold having at least one recess to form a carbon fiber having at least one recess in the cross-sectional shape;
Forming a fuel cell thin film using the carbon fiber;
A method for producing a thin film for a fuel cell, comprising: A method for producing a thin film for a fuel cell, comprising:
Extruding a fiber material made of a polymer material from a mold having at least one convex portion to form a fiber having at least one concave portion in a cross-sectional shape;
Applying carbonization to the fibers to form carbon fibers;
Forming a fuel cell thin film using the carbon fiber;
A method for producing a thin film for a fuel cell, comprising: A method for producing a thin film for a fuel cell, comprising:
A method for producing a thin film for a fuel cell, comprising forming a thin film for a fuel cell by weaving warp yarn having at least one concave portion in a cross-sectional shape and a weft yarn having no concave portion in a cross-sectional shape. A method for producing a thin film for a fuel cell, comprising:
A step of aligning the extending direction of fibers constituting the fuel cell thin film;
A step of gluing the fibers in a state where the extending direction of the fibers is aligned;
A method for producing a thin film for a fuel cell, comprising:   21. The fuel according to claim 20, wherein in the step of aligning the extending direction of the fibers, a plate material having grooves on the surface is used, and the extending direction of the fibers is aligned by inserting the fibers into the grooves. A method for producing a thin film for a battery.   21. The method for producing a thin film for a fuel cell according to claim 20, wherein in the step of aligning the extending direction of the fibers, the extending direction of the fibers is aligned by applying ultrasonic vibration or mechanical vibration. A separator disposed adjacent to the cathode and provided with a flow path for the cathode gas;
A gas flow path disposed on the back side of the separator with respect to the flow path of the cathode gas, and supplying the cathode gas to the flow path of the cathode gas;
The porous part which is arrange | positioned in at least one part of the said separator, and sends a water | moisture content from the flow path of the said cathode gas to the said gas flow path is further provided. Fuel cell. A gas flow path disposed on the back side of the separator with respect to the flow path of the cathode gas, and supplying the cathode gas to the flow path of the cathode gas;
The porous part which is arrange | positioned in at least one part of the said separator, and sends a water | moisture content from the flow path of the said cathode gas to the said gas flow path is further provided. Fuel cell.   The fuel cell according to any one of claims 1 to 11, 23, and 24, wherein the cathode gas flow path is configured so that an upstream side and a downstream side of the cathode gas flow path are close to each other.   The fuel cell according to claim 1, wherein the predetermined fiber has a hydrophilic group.   24. The fuel cell according to claim 1, wherein unevenness is provided on a surface of the moisture moving means.   25. The fuel cell according to claim 23, wherein the predetermined fiber is made of a substance having a higher capillary suction than the porous portion.   25. The fuel cell according to claim 24, wherein the moisture moving means is provided on at least a part of an inner wall of the cathode gas flow path.

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