JP2012048825A - Fuel battery, passage member and separator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve a discharging property for moisture contained in a reaction gas circulating in a fuel battery.SOLUTION: A fuel battery includes a power generator layer having an electrolyte film, a pair of separators, and a gas passage layer arranged between the power generator layer and at least one of the pair of separators and serving as a flow passage for a reaction gas. The gas passage layer is provided with a plurality of waveform-sectioned waveform elements, each of which has a projection part projecting and a recessed part recessed toward the separators arrayed alternately in a first direction, along a second direction substantially orthogonal to the first direction, at least a part of a top face of a projection part of one waveform element forms an integrated face with at least a part of a bottom face of a recessed part of an adjacent waveform element, and a plurality of through holes are formed between the waveform elements. A gap penetrating substantially in the second direction is formed between at least a part of a top face of a specific projection part as one projection part among a plurality of projection parts constituting a plurality of the waveform elements, and the separators.

Description

  The present invention relates to a fuel cell, and more particularly to a technique for discharging moisture in the fuel cell.

  A fuel cell, for example, a polymer electrolyte fuel cell, causes an electrochemical reaction by supplying a reaction gas (a fuel gas and an oxidizing gas) to a pair of electrodes (anode and cathode) arranged with an electrolyte membrane interposed therebetween, respectively. The chemical energy of the substance is converted into electrical energy.

  Conventionally, in a fuel cell, a gas flow path layer formed using a metal lath or expanded metal is provided between a power generator layer including an electrolyte membrane and a pair of electrodes and a separator, thereby improving reaction gas diffusibility. A technique for improving the power generation efficiency of a fuel cell is known (for example, Patent Document 1 below).

  However, the conventional technology does not sufficiently consider the influence of the moisture contained in the reaction gas on the performance of the fuel cell, such as generated water generated by power generation, and there is room for improvement in the performance of the fuel cell. there were. Such a problem is a problem common to fuel cells generally including a gas flow path layer between a power generator layer and a separator.

JP 2007-21040 A

  In consideration of at least a part of the above-mentioned problems, the problem to be solved by the present invention is to improve the discharge of moisture contained in the reaction gas flowing through the fuel cell.

  The present invention has been made to solve the above-described problems, and can be realized as the following forms or application examples.

Application Example 1 A fuel cell,
A power generation layer provided with an electrolyte membrane;
A pair of separators arranged with the power generation layer interposed therebetween;
A gas flow path layer disposed between the power generation body layer and at least one of the pair of separators and serving as a flow path for a reaction gas to be used for a power generation reaction in the power generation body layer, on the separator side A plurality of corrugated elements having a corrugated cross-section in which convex convex portions and concave portions concave on the separator side are alternately arranged along the first direction are provided along a second direction substantially orthogonal to the first direction. And at least a part of the top surface of the convex part in one of the corrugated elements forms a surface integral with at least a part of the bottom surface of the concave part in the adjacent corrugated element, and the corrugated element A gas flow path layer having a plurality of through holes formed therebetween,
Between at least a part of the top surface of the specific convex portion, which is at least one convex portion of the plurality of convex portions constituting the plurality of waveform elements, and substantially in the second direction. A fuel cell with a gap formed.

  The fuel cell having such a configuration includes a gas flow path layer that serves as a flow path for the reaction gas. In this gas flow path layer, the corrugated element of the corrugated cross-section in which convex portions convex to the separator side and concave concave portions are alternately arranged along the first direction is a second that is substantially orthogonal to the first direction. A plurality of continuous portions along the direction, wherein at least part of the top surface of the convex portion of one corrugated element forms a surface integral with at least part of the bottom surface of the concave portion of the adjacent corrugated element, and the corrugated element A plurality of through holes are formed therebetween, and the reaction gas can flow in a substantially second direction via a flow path formed by the convex portions, the concave portions, and the through holes. Here, a gap penetrating substantially in the second direction is formed between at least a part of the top surface of the specific convex portion that is at least one of the plurality of convex portions and the separator. Through the gap, moisture contained in the reaction gas, for example, generated water generated by the electrochemical reaction of the fuel cell can be circulated in the second direction by using the flow of the reaction gas. Therefore, compared to the case where the gap is not formed, the discharge property of moisture contained in the reaction gas to the outside of the fuel cell can be improved.

Application Example 2 The fuel cell according to Application Example 1, wherein at least one of the gaps is formed so as to penetrate substantially in the first direction.

  In the fuel cell having such a configuration, at least one of the gaps between the specific convex portion and the separator is formed so as to penetrate substantially in the first direction. Moisture staying on both sides in the direction 1 is easily connected. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas.

Application Example 3 In the fuel cell according to Application Example 1 or Application Example 2, the top surface of the specific convex portion includes a flat surface parallel to the separator, and the gap includes the separator and the flat surface. A fuel cell formed between the two.

  In the fuel cell having such a configuration, the gap is formed between the separator and the flat surface. Therefore, if the distance between the separator and the flat surface in the region where the gap is formed is adjusted, a water film can be formed in the gap. It becomes possible. When the water film is formed in the gap, the water film and the water staying around the specific convex portion are easily connected. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas.

[Application Example 4] The fuel cell according to any one of Application Examples 1 to 3, wherein the separator provided adjacent to the gas flow path layer includes at least one of the plurality of protrusions. A first protrusion protruding toward the gas flow path layer at a position corresponding to the first flow path, the first protrusion, and a top surface of the protrusion at a position corresponding to the first protrusion. , And the gap is formed between the top surfaces of the plurality of convex portions and the separator in a region where the first protrusions are not formed.

  In the fuel cell having such a configuration, the first and projecting portions of the separator are in contact with the top surface of the projecting portion of the gas flow path layer at a position corresponding to the first projecting portion, and the projecting portion and the first projecting portion are A gap is formed between the separator in a region that is not formed. With such a configuration, the gap can be suitably formed. Moreover, the gap can be formed simply by providing the first protrusion at a predetermined position of the separator having a relatively simple shape, and the manufacture of the fuel cell is facilitated.

[Application Example 5] The fuel cell according to any one of Application Example 1 to Application Example 3, wherein a top surface of at least one of the plurality of convex portions is provided on a top surface of another convex portion. A second protrusion that protrudes more toward the separator than the second protrusion, the second protrusion and the separator are in contact with each other, and the second protrusion of the plurality of protrusions is formed. A fuel cell in which the gap is formed between a non-existing region and the separator.

  In the fuel cell having such a configuration, the second protrusion formed on the top surface of at least one protrusion and the separator are in contact with each other, and the second protrusion of the plurality of protrusions is not formed. And a gap is formed between the separator and the separator. With such a configuration, the gap can be suitably formed.

[Application Example 6] The fuel cell according to any one of Application Example 1 to Application Example 3, wherein the convex portion includes a first convex portion having a relatively high height in a convex direction of a top portion of the convex portion. A relatively low second convex portion as the specific convex portion, the top portion of the first convex portion and the separator abut, and at least the top portion of the second convex portion and the separator A fuel cell having the gap formed therebetween.

  In the fuel cell having such a configuration, the top part of the first convex part having a relatively high height is in contact with the separator, and the top part of the second convex part having a relatively low height and the separator. A gap is formed between the two. With such a configuration, the gap can be suitably formed. Moreover, the gap can be formed without strict positioning when laminating the separator and the gas flow path layer, and the fuel cell can be easily manufactured.

[Application Example 7] In the fuel cell according to Application Example 1, each of the top surfaces of the plurality of convex portions includes a flat surface parallel to the separator, and the flat surface extends from the flat surface to the separator side. A first flat surface formed with a third protrusion that contacts the separator, and a second flat surface that does not include the third protrusion, and the gap includes the separator and the A first gap formed between the first flat surface excluding a region where the third protrusion is formed and penetrating at least in the substantially second direction; the separator and the second flat surface; And a second gap extending substantially in the first direction and substantially in the second direction.

  In the fuel cell having such a configuration, each of the top surfaces of the plurality of convex portions includes a flat surface parallel to the separator, and a third protrusion partially formed on a part of the flat surfaces. Since the part and the separator are in contact with each other, a gap penetrating in the substantially second direction is formed between each of the convex parts and the separator. Therefore, compared with the case where a gap is formed between some of the convex portions and the separator, the effect of circulating the moisture contained in the reaction gas in the substantially second direction using the flow of the reaction gas is greatly increased. Can be improved. In addition, since the gap is formed between the separator and the first or second flat surface, a water film is formed in the gap by adjusting the distance between the separator and the first and second flat surfaces in the gap. be able to. Therefore, the water film and the water staying around the convex portion are more easily connected. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas. Furthermore, since at least the second gap also penetrates substantially in the first direction, the moisture staying on both sides of the convex portion in the first direction is easily connected via the second gap. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas.

[Application Example 8] Application in which the gap is formed side by side in the substantially second direction between each of the plurality of convex portions arranged adjacent to each other in the substantially second direction and the separator. The fuel cell according to any one of Examples 1 to 7.

  In the fuel cell having such a configuration, the gaps are formed side by side in a substantially second direction, and therefore, in the path including the gaps, the flow direction of the reaction gas, that is, the discharge direction of moisture contained in the reaction gas. As a result, a water flow path is easily formed, and the discharge of moisture contained in the reaction gas can be improved. When the top surface of the convex portion is provided with a flat surface and the gap is formed between the flat surface and the separator, a water film can be formed in the gap. It becomes easy to form a flow, and it is possible to further improve the drainage of moisture.

[Application Example 9] In the plurality of wave elements to be continuously provided, only a part of the top surface of the convex part in the one wave element is integrated with only a part of the bottom surface of the concave part in the adjacent wave element. 9. The fuel cell according to any one of application examples 1 to 8, wherein a surface is formed.

  In the fuel cell having such a configuration, only a part of the top surface of the convex part and only a part of the bottom surface of the concave part form an integral surface, so that the fuel cell is formed by one concave part and the concave part adjacent thereto. The flow path can be communicated with the two-dimensional path on the separator. That is, it is possible to form a flow path that communicates in a planar manner on the separator in a substantially second direction. Since this planar communication channel is easy to form a continuous water flow, it is possible to easily discharge the accumulated water. In particular, when the top surface of the convex portion is provided with a flat surface, a water film is formed in the gap formed between the flat surface and the separator, and the gap penetrates substantially in the first direction, the gap Since the water in the planar communication channel adjacent to each other is easily connected through a water film formed in the gap, even if the accumulated water exists in the planar communication channel, the retained water is taken in. Thus, a continuous water flow is very easily formed, and water discharge performance is improved. In addition, by suppressing the retention of water, the flowability of the reaction gas is improved, and the generated water can be easily moved to the separator side. In this way, when a continuous water flow is formed, the generated water is guided to the separator side, and the generated water is promptly discharged to the outside of the fuel cell by the amount generated, so that the inside of the fuel cell The retention of water can be effectively suppressed.

Application Example 10 The plurality of recesses arranged adjacent to each other in the substantially second direction are different from the first direction of the first recess group including the plurality of recesses arranged in the first direction. The fuel cell according to application example 9 including a plurality of second recess groups each including the recesses arranged in the second direction.

  The fuel cell having such a configuration can meander a flow path communicating in a plane formed by recesses arranged substantially in the second direction. Therefore, in addition to the drainage of stagnant water, the diffusibility of the reaction gas can be improved.

Application Example 11 A notch portion in which a part of the top portion is notched to an outer edge on the separator side of the top surface having the flat surface is formed on the power generator layer side of the top portion of the convex portion. The fuel cell according to Application Example 3 or Application Example 7.

  In the fuel cell having such a configuration, the power generator layer side at the top of the convex portion is cut out to the outer edge on the separator side of the top surface of the convex portion having a flat surface. When it stagnates, it can promote that the said stagnant water contacts the stagnant water on the separator surface, and transfers to the separator surface side. Accordingly, it is possible to improve the drainage of the staying water. Moreover, by guiding the accumulated water to the separator surface and discharging it, it is possible to suppress the variation in the accumulated state of the accumulated water accumulated on the flat power generator layer side and the gas pressure loss from being varied. As a result, the supply and discharge of the reaction gas can be made uniform in the surface direction of the power generation layer, and the power generation efficiency can be improved.

[Application Example 12] The fuel cell according to Application Example 11, wherein the cut-out portion has a shape that is cut through the flat surface from the power generator layer side to the separator side.

  In the fuel cell having such a configuration, since the cutout portion penetrates to the separator side, the staying water staying on the flat power generator layer side is very likely to come into contact with the staying water on the separator surface. Therefore, the effect of application example 11 can be further enhanced.

The present invention can also be realized as the flow path member of Application Example 13 and the separators of Application Examples 14 and 15.
Application Example 13 A flow path member that forms a gas flow path related to a power generation reaction of a fuel cell, wherein a convex portion that is convex in a predetermined direction and a concave portion that is concave in the predetermined direction are the first direction. A plurality of corrugated elements having corrugated cross-sections arranged alternately along the second direction are provided along a second direction substantially orthogonal to the first direction, and at least one of the top surfaces of the convex portions of the one corrugated element. The plurality of portions form a surface integral with at least a part of the bottom surface of the concave portion in the adjacent corrugated element, and a plurality of through-holes are formed between the corrugated elements to constitute the plural corrugated elements The height in the convex direction of the top portion of at least one convex portion of the convex portions of the plurality of convex portions is different from the height in the convex direction of the top portion of the other convex portions of the plurality of convex portions.

Application Example 14 A separator for use in a fuel cell, wherein the fuel cell includes a power generation layer provided with an electrolyte membrane, a pair of separators disposed with the power generation layer interposed therebetween, and the power generation unit A gas flow path layer disposed between the layer and at least one of the pair of separators and serving as a flow path for a reaction gas supplied to the power generation reaction in the power generation body layer, and having a convexity protruding toward the separator side And a plurality of corrugated elements having a corrugated cross section in which concave portions recessed on the separator side are arranged along the first direction are continuously provided along a second direction substantially orthogonal to the first direction. At least a part of the top surface of the convex portion in one corrugated element forms a surface integral with at least a part of the bottom surface of the concave portion in the adjacent corrugated element, and a plurality of the corrugated elements are arranged between the corrugated elements. Gas passage layer with through holes formed therein At least one position corresponding to the convex portion, the separator having a protrusion protruding into the gas flow path layer side of the plurality of protrusions.
Application Example 15 A separator used in a fuel cell, wherein a stack surface with the other members of the fuel cell protrudes in a direction that intersects the stack surface from the flat portion, and a flat portion that is substantially flat. The separator provided with the protrusion part scattered on the surface.

2 is an explanatory diagram showing a schematic configuration of a fuel cell 20. FIG. 3 is a perspective view showing a schematic structure of a gas flow path layer 40. FIG. It is explanatory drawing which shows the shape of the waveform cross section with which the gas flow path layer 40 is provided. It is explanatory drawing which shows a part of the side view of the state which laminated | stacked the gas flow path layer 40 and the separator 70. FIG. FIG. 3 is an explanatory diagram showing a method for obtaining a metal lath 160 from a base material 150 using a lath cut processing apparatus 200 in order to manufacture a gas flow path layer 40. It is explanatory drawing which shows schematic structure of the lower blade 230 and the upper blade 240 of the lath cut processing apparatus 200. FIG. It is explanatory drawing which shows the state which pressed the base material 150 with the lath cut processing apparatus 200. FIG. It is a perspective view which shows schematic structure of the metal lath 160 obtained by the lath cut processing apparatus 200. FIG. It is explanatory drawing which shows the method of obtaining the process metal lath 170 from the metal lath 160 using the roll press apparatus 300. FIG. 3 is a perspective view showing a schematic structure of a processed metal lath 170 obtained by a roll press apparatus 300. FIG. It is explanatory drawing which shows the shape of the waveform cross section with which the gas flow path layer 440 as 2nd Example is provided. It is explanatory drawing which shows the shape of the waveform cross section with which the gas flow path layer 540 as a 2nd Example is provided. It is a perspective view which shows schematic structure of the gas flow path layer 640 as a 3rd Example. It is explanatory drawing which shows a part of side view of the state which laminated | stacked the gas flow path layer 640 and the separator 70. FIG. It is explanatory drawing which shows the shape of the waveform cross section with which the gas flow path layer 740 as a 4th Example is provided. It is explanatory drawing which shows a part of side view of the state which laminated | stacked the gas flow path layer 740 and the separator 70. FIG. It is explanatory drawing which shows a part of side view of the state which laminated | stacked the gas flow path layer 840 and the separator 870 as 5th Example. It is a perspective view which shows schematic structure of the gas flow path layer 940 as a 6th Example.

A. First embodiment:
A-1. Schematic configuration of fuel cell:
A schematic configuration of a fuel cell stack 100 as an embodiment of the present invention is shown in FIG. The fuel cell stack 100 is configured by stacking a plurality of polymer electrolyte fuel cells 20, arranging terminals and insulators (not shown) at both ends thereof, and sandwiching them with end plates 95 and 96. In this fuel cell stack 100, hydrogen gas as fuel gas and air as oxidant gas are supplied to the fuel cell 20 from the hydrogen supply manifold 95a and air supply manifold 95b, and the exhaust gas is supplied from the hydrogen discharge manifold 95c and air discharge manifold 95d. Discharged. Further, the cooling water is supplied from the cooling water supply manifold 95e to the fuel cell 20, and the waste water is discharged from the cooling water discharge manifold 95f.

  The fuel cell 20 is configured by stacking gas flow path layers 40 and 60 and separators 70 and 80 on both surfaces of a power generation layer 35. The power generation body layer 35 is configured by bonding gas diffusion layers 33a and 33b to both surfaces of an MEA (Membrane Electrode Assembly) 34 as an electrolyte membrane / electrode assembly. The MEA 34 includes a cathode electrode 32 a and an anode electrode 32 b on the surface of the electrolyte membrane 31. The electrolyte membrane 31 is a thin film of a solid polymer material that exhibits good proton conductivity in a wet state. In this embodiment, Nafion (registered trademark) is used for the electrolyte membrane 31. The cathode electrode 32a and the anode electrode 32b are electrodes in which a catalyst is supported on a carrier having conductivity. In this embodiment, carbon particles supporting a platinum catalyst, a polymer electrolyte constituting the electrolyte membrane 31, and With the same electrolyte.

  The gas diffusion layers 33a and 33b can be formed of a conductive member having gas permeability, such as carbon paper or carbon cloth, a metal mesh, or a foam metal. In this embodiment, carbon paper is used for the gas diffusion layers 33a and 33b. The gas diffusion layers 33a and 33b diffuse the oxidizing gas or the fuel gas and supply it to the entire surface of the cathode electrode 32a or the anode electrode 32b. The gas diffusion layers 33a and 33b have a smaller porosity than the gas flow path layers 40 and 60 described later, and have a current collecting function and a protection function for the MEA 34 in addition to the gas diffusion function. The gas diffusion layers 33a and 33b may have a function of adjusting the moisture content of the MEA 34.

  The power generator layer 35 is integrally formed with a seal gasket 36 disposed on the outer periphery thereof. The seal gasket 36 includes a hydrogen supply manifold 30a, an air supply manifold 30b, a hydrogen discharge manifold 30c, an air discharge manifold 30d, a cooling water supply manifold 30e, and a cooling water discharge manifold 30f. The seal gasket 36 is formed with convex portions surrounding each manifold and the outer periphery of the power generation layer 35 in the thickness direction, and the portions are separators stacked on both sides of the seal gasket 36. 70 and 80, and functions as a seal that suppresses leakage of fluid (fuel gas, oxidizing gas, cooling water) from the inside of the manifold and the power generation layer 35.

  The gas flow path layers 40 and 60 are members in which a large number of through holes are formed, and a metal lath is used in this embodiment. The gas flow path layer 40 is disposed between the anode electrode 32b side of the power generation body layer 35 and the separator 70, and the fuel gas (here, hydrogen gas) supplied via the separator 70 is supplied to the electrode surface of the MEA 34. The fuel gas is supplied to the anode electrode 32b side of the power generation layer 35 while flowing in a flow from one side to the other side. Similarly, the gas flow path layer 60 supplies an oxidizing gas (here, air) to the cathode electrode 32a side of the power generation layer 35. The gas flow path layers 40 and 60 are formed of a metal having corrosion resistance and conductivity, for example, stainless steel, titanium, titanium alloy or the like. In this embodiment, stainless steel is used. The detailed structure of the gas flow path layers 40 and 60 will be described later. In the present embodiment, the gas flow path layers 40 and 60 are provided on both surfaces of the power generation body layer 35. However, the power supply layer 35 may be provided only on one side.

  Separator 70,80 is a member which functions as a reaction gas partition, and has the same configuration. Hereinafter, the separator 70 will be described. The separator 70 is formed of a gas impermeable conductive member, for example, a member made of compressed carbon or stainless steel. In this example, stainless steel was used. In the separator 70, a flat cathode-side separator 71 provided on the cathode electrode 32a side, a flat anode-side separator 73 provided on the anode electrode 32b side, and an intermediate separator 72 disposed therebetween are integrated. Composed. The cathode separator 71 includes a hydrogen supply manifold 71a, an air supply manifold 71b, a hydrogen discharge manifold 71c, an air discharge manifold 71d, a cooling water supply manifold 71e, a cooling water discharge manifold 71f, and air communication holes 75 and 76. The air supplied to the air supply manifold 71b passes through the air communication hole 72b and the air communication hole 75 of the intermediate separator 72, and the gas flow path layer 60 of another fuel cell 20 provided facing the cathode side separator 71 ( (Not shown). The exhaust gas is discharged to the air discharge manifold 71d through the air communication hole 76 and the communication hole (not shown) of the intermediate separator 72.

  Similarly, the hydrogen supplied to the hydrogen supply manifold 71a is guided to the gas flow path layer 40 through the hydrogen communication hole 72a of the intermediate separator 72 and the communication hole (not shown) of the anode side separator 73, and the gas flow path After flowing through the layer 40, it is discharged to the hydrogen discharge manifold 71c via the communication holes (not shown) of the intermediate separator 72 and the anode side separator 73. The intermediate separator 72 is formed with a plurality of cutouts along the long side direction of a substantially rectangular outline, and both ends of the cutouts communicate with the cooling water discharge manifold 71f and the cooling water supply manifold 71e, respectively. The separator 70 is not limited to the above-described three-layer structure. For example, the cathode side separator 71 and the anode side separator 73 may have a two-layer structure, and a shape corresponding to a communication hole formed in the intermediate separator 72 may be formed inside the cathode side separator 71 and / or the anode side separator 73. Good.

A-2. Structure of gas flow path layers 40 and 60:
The structure of the gas flow path layers 40 and 60 constituting the fuel cell 20 described above will be described. In the present embodiment, since the gas flow path layer 40 and the gas flow path layer 60 have the same structure, the structure of the gas flow path layer 40 will be described below. A schematic structure of the gas flow path layer 40 is shown in FIG. In FIG. 2, the upper side of the gas flow path layer 40 is the separator 70 side in the fuel cell 20, and the lower side is the power generator layer 35 side. As shown in the figure, in the gas flow path layer 40, convex portions 41 convex in a predetermined direction (separator 70 side) and concave portions 42 concave in the predetermined direction are alternately arranged along the first direction D1. A plurality of corrugated elements WSE having a corrugated cross section are provided. In the present embodiment, the convex portions 41 and the concave portions 42 are arranged in the same cycle. The plurality of waveform elements WSE are continuously arranged with a certain gradient along a second direction D2 substantially orthogonal to the first direction D1. In the plurality of waveform elements WSE, a part of the top surface 43 of the convex portion 41 in one waveform element WSE and a part of the bottom surface 44 of the concave portion 42 in the waveform element WSE adjacent to the waveform element WSE are integrated. It is comprised so that a smooth surface may be formed. In FIG. 2, one of the top surface 43 and the bottom surface 44 is indicated by hatching. Further, a plurality of through holes TH are formed between the plurality of waveform elements WSE.

  The convex portion 41 constituting the waveform element WSE includes a first convex portion 41a and a second convex portion 41b. The first convex portion 41a includes, on the top surface 43, a first flat surface 43a that is parallel to the laminated surface of the separator 70 and a protruding portion 43b that protrudes from the flat surface 43a toward the separator 70. The protrusion 43b is formed so as to cross the first flat surface 43a along the second direction D2. When the gas flow path layer 40 and the separator 70 are stacked, the top of the protruding portion 43b contacts the stacked surface of the separator 70. In the present embodiment, the top of the projecting portion 43b is formed so as to be in contact with the separator 70 by a line, but may be formed in a shape that makes contact with the surface. The protrusion 43b corresponds to the second protrusion and the third protrusion in the claims. The 2nd convex part 41b is provided with the 2nd flat surface 43c parallel to the lamination surface of the separator 70 on the top surface 43. As shown in FIG. The second convex portion 41b does not have a protruding shape like the protruding portion 43b. The height in the convex direction of the second flat surface 43c is formed to be the same as the height in the convex direction of the first flat surface 43a. In the present embodiment, the first protrusions 41a and the second protrusions 41b are alternately arranged along the first direction D1. In FIG. 2, the flat surfaces 43a and 43c are shown in an enlarged manner and do not match the actual relative dimensions. In addition, the number and arrangement of the protrusions 43b are not limited to the above-described form, and are appropriately set within a range in which the contact resistance with the separator 70 can be suppressed to a desired level or less in consideration of the area in contact with the separator 70. do it. For example, if there is no problem in the contact resistance with the separator 70, the protrusion 43b may be provided on every second protrusion 41 among the plurality of protrusions 41 arranged in the second direction D2, You may provide in every 3rd convex part 41 among the several convex parts 41 located in a line in 1 direction D1.

  In addition, as described above, the plurality of waveform elements WSE includes a part of the top surface 43 of the convex portion 41 in one waveform element WSE and a part of the bottom surface 44 of the concave portion 42 in the waveform element WSE adjacent to the waveform element WSE. Are formed so as to form an integral surface. With this configuration, one recess 42 and the recess 42 that is generally adjacent to the recess 42 in the second direction D2 are configured such that when the gas channel layer 40 and the separator 70 are stacked, the gas channel layer 40 of the separator 70 is stacked. Communication is possible through a two-dimensional route along the side surface. By forming the recess 42 substantially continuously in the second direction D2, a channel CH1 as a main channel through which the oxidizing gas flows approximately along the second direction D2 is formed.

  In the present embodiment, the recesses 42 forming the flow channel CH1 are constituted by a group of recesses 42 that are aggregates of the recesses 42 arranged in two directions. Specifically, the recesses 42 include a first recess group arranged in a predetermined number in a predetermined direction and a second recess arrayed in a predetermined number in a direction different from the first recess group. A group is formed in a repeated arrangement. With this configuration, the flow channel CH1 is formed as a meandering flow channel substantially along the second direction D2. Moreover, the 1st convex part 41a and the 2nd convex part 41b which are alternately arranged along the 1st direction D1 are arrange | positioned between the two recessed parts 42 along the direction of the 1st direction D1. Therefore, it has a meandering shape substantially the same as that of the flow channel CH1 along the second direction D2. The direction in which the recesses 42 are arranged is not limited to two different directions, and may be three or more directions. Even in this case, the channel CH1 can be meandered. However, the configuration of meandering the flow channel CH1 is not essential, and the configuration in which the concave portions 42 are arranged in only one direction may be employed.

  In the gas flow path layer 40, the surface on the power generation body layer 35 side of each recess 42 is provided with a flat surface parallel to the power generation body layer 35 (not shown). This flat surface is formed in substantially the same size as the second flat surface 43c.

A-3. Lamination mode of gas flow path layers 40, 60 and separators 70, 80:
A stacking mode of the gas flow path layers 40 and 60 and the separators 70 and 80 in the fuel cell 20 will be described. In the present embodiment, the gas flow path layer 40 and the gas flow path layer 60 and the separator 70 and the separator 80 have the same configuration. It demonstrates as a lamination | stacking aspect. A waveform cross section of the waveform element WSE constituting the gas flow path layer 40 is shown in FIG. As shown in the figure, the waveform element WSE has a concavo-convex shape in which the first convex portion 41a, the concave portion 42, the second convex portion 41b, and the concave portion 42 are repeated as one unit. Further, the height of the top of the first convex portion 41a in the convex direction, that is, the height of the top of the projecting portion 43b included in the first convex portion 41a, and the second flat surface 43c of the second convex portion 41b. The difference in ΔH corresponding to the height of the protrusion 43b is ensured from the height in the convex direction. When the gas flow path layer 40 and the separator 70 are stacked, the top of the protruding portion 43b abuts on the separator 70, so that the height between the second flat surface 43c and the separator 70 is ΔH. A gap G1 is generated. Similarly, between the first flat surface 43a and the separator 70, gaps G2 and G3 having a height of ΔH are formed on both sides of the protrusion 43b. The gap G1 corresponds to the second gap in the claims, and the gaps G2 and G3 correspond to the first gap in the claims.

  This ΔH may be set as appropriate. In this embodiment, ΔH is included in the oxidizing gas flowing through the flow path formed by the gas flow path layer 40 when the gas flow path layer 40 and the separator 70 are stacked. The thickness is such that a water film can be formed in the gaps G1 to G3 by moisture. As thickness which can form a water film, it can be set as about 20-50 micrometers, for example.

  In order to clarify the stacking mode of the gas channel layer 40 and the separator 70, a part of a side view of the gas channel layer 40 when the gas channel layer 40 and the separator 70 are stacked is shown in FIG. Shown in In FIG. 4, the side view of the gas flow path layer 40 of the site | part containing the two 1st convex parts 41a and the 1st 2nd convex part 41b is shown. As shown in the figure, in a side view of the gas flow path layer 40, the top of the protrusion 43b of the gas flow path layer 40 and the separator 70 are in contact with each other, and a gap is formed between the protrusion 43b and the separator 70. Absent. On the other hand, a gap G <b> 1 is formed between the second flat surface 43 c and the separator 70. Through this gap G1, the channels CH1 formed on both sides of the second convex portion 41b in the first direction D1 communicate with each other.

A-4. Manufacturing method of gas flow path layer 40:
The gas flow path layers 40 and 60 described above can be manufactured as follows, for example. Hereinafter, the manufacturing method of the gas flow path layer 40 will be described. In the manufacture of the gas flow path layer 40, first, a plate-like base material 150 is prepared, and a metal lath 160 is obtained using a lath cutting apparatus 200 shown in FIG. The lath cutting apparatus 200 includes rollers 210 and 220, a lower blade 230, and an upper blade 240. While the base material 150 is fed at a predetermined pitch by the rollers 210 and 220, the lower blade 230 and the upper blade 240 are used. By performing the pressing process, the base material 150 is processed into a metal lath 160 having a through hole TH.

  This process will be specifically described below. As shown in FIG. 6, the lower blade 230 includes convex portions 231 and concave portions 232 that are alternately arranged at a predetermined pitch on the side wall on the feed direction side of the base material 150. Further, the lower blade 230 includes a shearing blade 233 at the upper end edge of the concave portion 232 opposite to the base material feeding direction. The lower blade 230 is configured to reciprocate in the left-right direction (the direction in which the convex portion 231 and the concave portion 232 are arranged) by an actuator (not shown). As shown in FIG. 6, the upper blade 240 includes convex portions 241 and concave portions 242 arranged alternately at a predetermined pitch at the end portion on the lower blade 230 side. Further, the upper blade 240 includes a shearing blade 243 at the lower end edge of the convex portion 241 opposite to the base material feeding direction. The upper blade 240 is configured to be able to reciprocate in the vertical direction (direction orthogonal to the base material feeding direction and the horizontal direction) and the horizontal direction by an actuator (not shown). The concave portion 232 and the convex portion 231 of the lower blade 230 and the convex portion 241 and the concave portion 242 of the upper blade 240 are engaged with each other by moving the upper blade 240 toward the lower blade 230. At this time, a cut can be made in the base material 150 between the shearing blade 233 of the lower blade 230 and the shearing blade 243 of the upper blade 240.

  The base material 150 is set in the lath cutting apparatus 200 provided with the lower blade 230 and the upper blade 240, and the base material 150 is moved until its end portion is positioned between the lower blade 230 and the upper blade 240, When the upper blade 240 is moved downward to a position where it engages with the lower blade 230, an uneven shape is formed at the end of the substrate 150. FIG. 7 shows a state where the lower blade 230 and the upper blade 240 are engaged with each other with the base material 150 interposed therebetween. As shown in the drawing, the base material 150 is formed in a convex shape on the upper blade 240 side, with the top surface being a portion where the convex portion 231 of the lower blade 230 and the concave portion 242 of the upper blade 240 are engaged. At the same time, the base material 150 is formed in a concave shape on the upper blade 240 side, with the bottom surface of the portion where the concave portion 232 of the lower blade 230 and the convex portion 241 of the upper blade 240 are engaged. The concavo-convex shape thus formed forms the waveform element WSE described above.

  Next, the upper blade 240 is moved upward to return to the original position, and the base material 150 is moved in the base material feed direction by a predetermined pitch (a length corresponding to the width of the concave portion 232 in the base material feed direction). When the lower blade 230 and the upper blade 240 are moved to one side in the left-right direction by a predetermined pitch, and then the upper blade 240 is moved downward to a position where it engages with the lower blade 230, the second edge is formed at the end of the base material 150. A waveform element WSE is formed. If this process is repeated, as shown in FIG. 8, the convex portions 161 and the concave portions 162 are alternately arranged along the first direction D1, and these metal laths are continuously arranged along the second direction D2. 160 is formed.

  When the metal lath 160 is obtained in this way, next, as shown in FIG. 9, flat surfaces 173 and 174 are formed on the metal lath 160 using a roll press apparatus 300 to obtain a processed metal lath 170. Specifically, the roll press apparatus 300 includes rollers 310 and 320 and a stage 330. The metal lath 160 is set on the stage 330, the metal lath 160 is inserted between the rollers 310 and 320 rotating in the direction of the arrow, and the metal lath 160 is compressed in the vertical direction and pulled out in the second direction D2. And a flat surface 173 formed by bending the upper end of the convex portion 171 inward and a flat surface 174 formed by bending the lower end of the concave portion 172 inward. A processed metal lath 170 having the above can be obtained. A perspective view of the processed metal lath 170 thus obtained is shown in FIG. As shown in the figure, the processed metal lath 170 has convex portions 171 and concave portions 172 arranged alternately along the first direction D1, and these are continuously provided along the second direction D2. The top surface has a flat surface 173 (the flat surface 174 is not shown). That is, the shape of the processed metal lath 170 is a shape that does not include the protruding portion 43 b as compared with the gas flow path layer 40. The flat surface 173 of the processed metal lath 170 is a portion corresponding to the first flat surface 43 a and the second flat surface 43 c of the gas flow path layer 40.

  When the processed metal lath 170 is obtained in this way, the protruding portion 43b is then formed on a part of the flat surface 173 of the processed metal lath 170 by pressing. Thus, the gas flow path layer 40 described above is completed.

A-5. effect:
The fuel cell 20 described above includes a gas flow path layer 40 that serves as a flow path for fuel gas. In the gas flow path layer 40, the corrugated element WSE having a corrugated cross section in which convex portions 41 convex to the separator 70 side and concave concave portions 42 are alternately arranged along the first direction D1 is formed in the first direction D1. And a plurality of the top surfaces 43 of the convex portions 41 of one waveform element WSE are at least one of the bottom surfaces 44 of the concave portions 42 of the adjacent waveform elements WSE. A plurality of through holes TH are formed between the corrugated elements WSE, forming a surface that is integral with the portion, and approximately second through a flow path formed by the convex portions 41, the concave portions 42, and the through holes TH. The fuel gas can flow in the direction D2. Here, since the gap G1 or the gaps G2 and G3 penetrating substantially in the second direction D2 is formed between the top surface 43 of each of the plurality of convex portions 41 and the separator 70, the gap Fuel moisture contained in the fuel gas (for example, moisture generated in the cathode electrode 32a due to the electrochemical reaction transferred to the fuel gas on the anode electrode 32b side through the electrolyte membrane 31) through G1 to G3. The gas can be circulated in the second direction D2 using the gas flow. Accordingly, it is possible to improve the drainage of moisture contained in the fuel gas as compared with the case where the gaps G1 to G3 are not formed. In addition, if at least 1 or more convex part 41 which forms gap G1-G3 between separators 70 exists, the above-mentioned effect can be acquired in the said location. Moreover, since the gas flow path layer 60 has the same structure as the gas flow path layer 40, the discharge property of the water | moisture content contained in oxidizing gas can be improved for the same reason. In particular, since the oxidizing gas contains a large amount of produced water generated at the cathode electrode 32a, it is possible to expect a remarkable effect of suppressing generation of flooding and improving power generation efficiency by improving the drainage of moisture.

  Further, the fuel cell 20 is formed so that the gap G1 between the second convex portion 41b and the separator 70 penetrates substantially in the first direction D1. Moisture staying on both sides of the convex portion 41b in the first direction D1 is easily connected via the gap G1. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas. If at least one or more second convex portions 41b that form the gap G1 with the separator 70 are present, the above-described effects can be obtained at the locations where the second convex portions 41b are present.

  In the fuel cell 20, since the gaps G1 to G3 are formed between the separator 70 and the second flat surface 43c or the first flat surface 43a, the separator 70 in the region where the gaps G1 to G3 are formed. By adjusting the distance ΔH from the second flat surface 43c or the first flat surface 43a, it is possible to form a water film in the gaps G1 to G3. Therefore, the water film formed in the gaps G1 to G3 and the water staying around the convex portion 41 are easily connected. As a result, the size of the staying water is increased, and the staying water can be easily discharged using the flow of the reaction gas.

  Further, in the fuel cell 20, only a part of the top surface 43 of the convex part 41 and only a part of the bottom surface 44 of the concave part 42 form an integral surface, so that one concave part 42 is adjacent to this. The recess 42 can communicate with each other through a two-dimensional route. That is, a flow path that communicates in a planar manner can be formed on the separator 70 in the substantially second direction D2, and the retained water can be easily discharged. Specifically, as shown in FIG. 2, the recesses 42 adjacent to each other in the substantially second direction D2 can be continuous to form the channel CH1 communicating in a plane on the separator 70. It is easy to form a continuous water flow on 70. As a result, the accumulated water on the separator 70 can be easily discharged. Moreover, the water present in each of the channels CH1 adjacent via the second convex portion 41b is formed in the gap G1 between the second flat surface 43c of the second convex portion 41b and the separator 70. Since it becomes easy to connect via a water film, even when a stagnant water exists in channel CH1, the stagnant water is taken in and the flow of continuous water is very easy to be formed.

  Furthermore, since each of the gaps G1 to G3 is formed in the second direction D2 in the fuel cell 20, the flow direction of the reaction gas (second direction) is a path including the gaps G1 to G3. D2), that is, the flow path of water tends to be formed in the direction in which the moisture contained in the reaction gas is discharged, and the discharge of moisture contained in the reaction gas can be improved. In addition, since the gaps G1 to G3 are formed between the second flat surface 43c or the first flat surface 43a and the separator 70, it is possible to form a water film in the gaps G1 to G3, which is continuous. Water flow is likely to be formed. Specifically, as shown in FIG. 2, a continuous water flow in the channel CH2 is easily formed by the gap G1, and a continuous water flow in the channels CH3 and CH4 is formed by the gaps G2 and G3. It becomes easy to form, and the discharge | emission property of the stagnant water to the substantially 2nd direction D2 can further be improved. Moreover, since the channel CH2 allows the channels CH1 on both sides to communicate with each other, the flow of water in the channel CH2 and the water flow in the channels CH1 on both sides can be connected, and the accumulated water can be discharged. The sex can be further enhanced. Since the channel CH2 is likely to be a water channel through which water continuously flows due to the water film formed in the gap G1, even when the accumulated water locally stays in the channel CH1 and no continuous water flow is formed. The accumulated water can be suitably discharged by capturing the water flow in the channel CH2.

  As described above, when a continuous water flow toward the outside of the fuel cell 20 is formed, the water discharge performance is increased, and the retention of the water is suppressed, thereby improving the flowability of the reaction gas, It becomes easy to move to the separator 70 side. Therefore, the generated water generated by the cathode electrode 32a can be guided to the separator 70 side, and the generated water can be quickly discharged to the outside of the fuel cell 20 by the generated amount. It can suppress very effectively that it retains. As a result, the staying water does not deteriorate the diffusibility of the reaction gas, so that the diffusibility of the reaction gas is improved and the power generation performance can be improved. Further, since the staying water can be prevented from remaining inside the fuel cell 20 after the power generation operation of the fuel cell stack 100 is stopped, the sub-freezing start performance of the power generation operation is improved. In addition, the accumulated water is led to the surface of the separator 70 and discharged quickly, thereby suppressing the dispersion of the accumulated state of the accumulated water in the fuel cell 20 and between the plurality of fuel cells 20 and the gas pressure loss varies. Can be suppressed. As a result, the supply and discharge of the reaction gas can be made uniform in the surface direction of the power generation body layer 35 and between the fuel cells 20, and the power generation efficiency can be improved.

  The fuel cell 20 includes a plurality of recesses 42 arranged adjacent to each other in the substantially second direction D2, that is, the recesses 42 constituting the flow channel CH1 are substantially in the second direction D2 and are different from each other. Since they are arranged in the direction, the channel CH1 can be formed in a meandering shape. As a result, the diffusibility of the reaction gas flowing through the flow channel CH1 is improved as compared to the case where the flow channel CH1 is formed in a linear shape. Efficiency can be improved.

B. Second embodiment:
A second embodiment of the present invention will be described. The fuel cell as the second embodiment is different from the first embodiment only in the configuration of the gas flow path layer. Hereinafter, the configuration of the gas flow path layer 440 as the second embodiment will be described only with respect to differences from the first embodiment, and the description of the configuration common to the first embodiment will be omitted. A waveform cross section of the waveform element WSE constituting the gas flow path layer 440 is shown in FIG. As shown in the figure, the corrugated element WSE of the gas flow path layer 440 has a concavo-convex shape in which the first convex portion 441a, the concave portion 442, the second convex portion 441b, and the concave portion 442 are repeated as one unit.

  The top surface of the first convex portion 441a includes a protruding portion 443b in which the height in the convex direction increases linearly from the end in the first direction D1 toward the center. Similar to the second flat surface 43c of the first embodiment, the top surface of the second convex portion 441b includes a second flat surface 443c parallel to the laminated surface of the separators 70. The height in the convex direction of the top portion of the first convex portion 441a, that is, the height of the top portion of the protruding portion 443b included in the first convex portion 441a, and the convex direction of the second flat surface 443c of the second convex portion 441b A difference of ΔH corresponding to the height of the protruding portion 443b is secured. When the gas flow path layer 440 and the separator 70 are stacked, the top of the projecting portion 443b abuts on the separator 70, so that the height between the second flat surface 443c and the separator 70 is ΔH. A gap G41 is generated. Similarly, gaps G42 and G43 having a maximum height ΔH are formed on both sides of the top portion between the region excluding the top portion of the protruding portion 43b and the separator 70.

  The fuel cell including the gas flow path layer 440 having such a configuration is caused by the fact that the gaps G2 and G3 are formed between the flat surface of the gas flow path layer 40 and the separator 70 described in the first embodiment. Except for the effects, the same effects as in the first embodiment are obtained.

  An example of another configuration of the gas flow path layer as the second embodiment will be described as a gas flow path layer 540. FIG. 12 shows a waveform cross section of the waveform element WSE constituting the gas flow path layer 540. As shown in the figure, the corrugated element WSE of the gas flow path layer 540 has a concave and convex shape that repeats the first convex portion 541a, the concave portion 542, the second convex portion 541b, and the concave portion 542 as one unit.

  The top surface of the first convex portion 541a includes a protruding portion 543b whose height in the convex direction increases in a curve from the end portion toward the center. Similar to the second flat surface 43c of the first embodiment, the top surface of the second convex portion 541b includes a second flat surface 543c as a flat surface parallel to the stacked surface of the separator 70. The height in the convex direction of the top portion of the first convex portion 541a, that is, the height of the top portion of the protruding portion 543b included in the first convex portion 541a, and the convex direction of the second flat surface 543c of the second convex portion 541b The difference of ΔH corresponding to the height of the protruding portion 543b is secured. When the gas flow path layer 540 and the separator 70 are stacked, the top of the projecting portion 543b abuts on the separator 70, so that the height between the second flat surface 543c and the separator 70 is ΔH. A gap G51 is generated.

  The fuel cell including the gas flow path layer 540 having such a configuration has the same effects as described in the first embodiment except that the gaps G2 and G3 are formed between the gas flow path layer 40 and the separator 70. The same effects as in the first embodiment are achieved.

  As is clear from the above description, the first convex portion does not necessarily have a flat surface on the top surface, and the top portion of the first convex portion is more convex than the top portion of the second convex portion. It suffices if the gap is formed relatively high in the direction and at least a gap can be formed between the second top and the separator 70. In addition, although illustration is abbreviate | omitted, the 2nd convex part does not necessarily need to be equipped with the flat surface on the top surface similarly, For example, between the separators 70 like gap G41, G42, for example. It is only necessary to form a gap that penetrates at least approximately in the second direction D2.

C. Third embodiment:
A third embodiment of the present invention will be described. The fuel cell as the third embodiment is different from the first embodiment only in the configuration of the gas flow path layer. Hereinafter, the configuration of the gas flow path layer 640 as the third embodiment will be described only with respect to differences from the first embodiment, and the description of the configuration common to the first embodiment will be omitted. A schematic structure of the gas flow path layer 640 is shown in FIG. The gas flow path layer 640 includes a first protrusion 641a and a second protrusion 641b. The first convex portion 641a corresponds to the first convex portion 41a of the first embodiment, and the configuration is slightly different from that of the first convex portion 41a. This difference will be described below. The second convex portion 641b corresponds to the second convex portion 41b of the first embodiment and has the same configuration as the second convex portion 41b.

  The first convex portion 641a includes a first flat surface 643a and a protruding portion 643b on its top surface 643. The first flat surface 643a corresponds to the first flat surface 43a of the first embodiment, and has the same configuration as the first flat surface 43a. The protruding portion 643b corresponds to the protruding portion 43b of the first embodiment, but the configuration is different from the protruding portion 43b. Specifically, the protrusion 643b protrudes from the first flat surface 643a toward the separator 70, and the protrusion 643b has a shape in which the first flat surface 643a is formed on the outer periphery of the protrusion 643b. Different from 43b. The gas flow path layer 640 having such a configuration can form the flow paths CH1 to CH4 as in the first embodiment.

  FIG. 14 shows a part of a side view of the gas flow path layer 640 when the gas flow path layer 640 and the separator 70 are stacked. FIG. 14 shows a side view of the gas flow path layer 640 at a portion including two first convex portions 641a and one second convex portion 641b. As illustrated, in the side view of the gas flow path layer 640, a gap G61 is formed between the second flat surface 643c and the separator 70, as in the first embodiment. Through this gap G61, the channels CH1 formed on both sides of the second convex portion 641b communicate with each other. Further, the top of the protruding portion 643b and the separator 70 come into contact with each other, and gaps G64 and G65 are formed between the first flat surface 643a and the separator 70 on both sides of the protruding portion 643b in the first direction D1. ing. Through the gaps G64 and G65, the channels CH1 formed on both sides of the first convex portion 641a communicate with each other in the first direction D1.

  The fuel cell including the gas flow path layer 640 having such a configuration has the same effects as those of the first embodiment. In addition, in the fuel cell, the protrusion 643b included in the first protrusion 641a of the gas flow path layer 640 has a shape in which the first flat surface 643a is formed on the outer periphery of the protrusion 643b. The channels CH1 formed on both sides of the first convex portion 641a in the first direction D1 can be communicated between the first flat surface 643a and the separator 70 through gaps G64 and G65. . As a result, the moisture staying on both sides of the first convex portion 641a is easily connected via the gaps G64 and G65, and the effect of easily discharging the staying water can be further enhanced.

D. Fourth embodiment:
A fourth embodiment of the present invention will be described. The fuel cell as the fourth embodiment differs from the first embodiment only in the configuration of the gas flow path layer. Hereinafter, the configuration of the gas flow path layer 740 as the fourth embodiment will be described only with respect to differences from the first embodiment, and the description of the configuration common to the first embodiment will be omitted. FIG. 15 shows a waveform cross section of the waveform element WSE constituting the gas flow path layer 740. As shown in the figure, the corrugated element WSE of the gas flow path layer 740 has a concavo-convex shape in which the first convex portion 741a, the concave portion 742, the second convex portion 741b, and the concave portion 742 are repeated as one unit.

  The top surface of the first convex portion 741 a includes a first flat surface 743 a that is parallel to the stacked surface of the separator 70. The first flat surface 743a does not have a protruding shape like the protruding portion 43b of the first embodiment. Similar to the second flat surface 43c of the first embodiment, the top surface of the second convex portion 741b includes a second flat surface 743c parallel to the stacked surface of the separators 70. The height in the convex direction of the first flat surface 743a is formed to be relatively higher than the height in the convex direction of the second flat surface 743c. The difference in height in the convex direction between the first flat surface 743a and the second flat surface 743c is ensured by ΔH. When the gas flow path layer 740 and the separator 70 are stacked, the first flat surface 743a of the first convex portion 741a having a relatively high height in the convex direction contacts the separator 70. A gap G71 having a height ΔH is formed between the flat surface 743c and the separator 70.

  FIG. 16 shows a part of a side view of the gas flow path layer 740 when the gas flow path layer 740 and the separator 70 are stacked. FIG. 16 shows a side view of the gas flow path layer 740 at a portion including two first convex portions 741a and one second convex portion 741b. As shown in the figure, in the side view of the gas flow path layer 740, a gap G71 is formed between the second flat surface 743c and the separator 70, as in the first embodiment. Through this gap G71, the channels CH1 formed on both sides of the second convex portion 741b communicate with each other. Note that the gas flow path layer 740 is formed by etching or cutting a portion corresponding to the second flat surface 743c of the second convex portion 741b with respect to the processed metal lath 170 shown in FIG. In addition, ΔH can be formed between the first flat surface 743a and the second flat surface 743c.

  The fuel cell provided with the gas flow path layer 740 having such a configuration has the effect due to the gaps G2 and G3 formed between the gas flow path layer 40 and the separator 70 described in the first embodiment. Except for this, the same effects as in the first embodiment are obtained. As is clear from the above description, the gap between the gas flow path layer and the separator is not limited to being formed by providing protrusions on the protrusions constituting the gas flow path layer, but the protrusions of the respective protrusions. You may form by setting the height of a direction to several height.

E. Example 5:
A fifth embodiment of the present invention will be described. The fuel cell as the fifth embodiment is different from the first embodiment in the configuration of the gas flow path layer and the configuration of the separator. Hereinafter, the configuration of the gas flow path layer 840 and the separator 870 as the fifth embodiment will be described only with respect to differences from the first embodiment, and the description of the configuration common to the first embodiment will be omitted. FIG. 17 shows a part of a side view of the gas flow path layer 840 when the gas flow path layer 840 and the separator 870 are stacked. FIG. 17 corresponds to FIG. 4 of the first embodiment. The gas flow path layer 840 has the same configuration as the processed metal lath 170 shown in the first embodiment. That is, the gas flow path layer 840 has a configuration in which the gas flow path layer 40 according to the first embodiment does not include the protruding portion 43b. Specifically, as shown in FIG. 17, the convex portions constituting the corrugated element WSE are configured only by the convex portions 841 having the same structure, and the top surfaces of the convex portions 841 are parallel to the laminated surface of the separator 870. 2 flat surfaces 843c.

  The separator 870 includes a protruding portion 871 that protrudes from the laminated surface of the separator 870 toward the gas flow path layer 840 at a position corresponding to the first flat surface 43a of the gas flow path layer 40 of the first embodiment. In other words, the separator 870 has a substantially flat flat portion on the stack surface with the gas flow path layer 840, and protrudes in a direction intersecting the stack surface from the flat portion, and the projecting portions 871 scattered on the stack surface. And. The protrusion 871 corresponds to the first protrusion of the claims. The end surface of the protruding portion 871 on the gas flow path layer 840 side is formed flat. Note that the end surface of the protruding portion 871 on the gas flow path layer 840 side is not necessarily formed as a flat surface, and may have a sharp shape or a bent R shape. In this embodiment, the area of the end surface of the protruding portion 871 is smaller than that of the second flat surface 843c. In a state where the separator 870 and the gas flow path layer 840 are stacked, the end surface of the protruding portion 871 and the second flat surface 843c are in contact with each other. In the present embodiment, the positional relationship is such that the center of the end surface of the protruding portion 871 is in contact with the second flat surface 843c. Note that the protruding portion 871 can be formed by, for example, etching or cutting.

  As shown in FIG. 17, a gap G <b> 81 is formed between the second flat surface 843 c that does not contact the separator 870 and the separator 870 in a side view of the gas flow path layer 840. Through this gap G81, the channels CH1 formed on both sides in the first direction D1 of the convex portion 841 having the second flat surface 843c that does not contact the separator 870 communicate with each other. Further, between the second flat surface 843c that contacts the separator 870 and the region where the protruding portion 871 of the separator 870 is not formed, gaps G84 and G85 are provided on both sides of the protruding portion 871 in the first direction D1. Is formed.

  The fuel cell including the gas flow path layer 840 and the separator 870 has the same effects as the first embodiment because the gaps G81 to 83 corresponding to the gaps G1 to G3 of the first embodiment are formed. Moreover, the gaps G81 to G83 can be formed simply by providing the convex portion 841 at a predetermined position on the front surface of the flat separator, which facilitates the manufacture of the fuel cell. As is clear from the above description, the protrusion for forming a gap between the gas flow path layer and the separator is not limited to being provided on the gas flow path layer side, but may be provided on the separator side.

F. Example 6:
A sixth embodiment of the present invention will be described. The fuel cell as the sixth embodiment is different from the first embodiment only in the configuration of the gas flow path layer. Hereinafter, the configuration of the gas flow path layer 940 as the sixth embodiment will be described only with respect to differences from the first embodiment, and the description of the configuration common to the first embodiment will be omitted. A schematic structure of the gas flow path layer 940 is shown in FIG. The gas flow path layer 940 includes a first convex portion 941a and a second convex portion 941b. The first convex portion 941a corresponds to the first convex portion 41a of the first embodiment, and the second convex portion 941b corresponds to the second convex portion 41b of the first embodiment.

  The configuration of the first convex portion 941a and the second convex portion 941b has substantially the same configuration as the convex portion 41a and the convex portion 41b of the first embodiment. Specifically, the first protrusion 941a has, on its top surface 943, a first flat surface 943a and a protrusion 943b having the same configuration as the first flat surface 43a and the protrusion 43b of the first embodiment. It has. Further, the second convex portion 941b is provided with a second flat surface 943c having the same configuration as the second flat surface 43c of the first embodiment on the top surface 943. However, the first convex portion 941a and the second convex portion 941b are different from the first embodiment in the points described below. That is, on the power generation body layer 35 side of the top portions of the first convex portion 941a and the second convex portion 941b, a part of the top portion is the outer edge on the separator 70 side of the top surface 943, that is, the first The difference from the first embodiment is that notches 943d and 943e are formed by cutting out to the outer edge of the flat surface 943a or the second flat surface 943c. In the present embodiment, the notches 943d and 943e have a shape that is cut through to the separator 70 side.

  Since the fuel cell including the gas flow path layer 940 having such a structure has notches 943d and 943e formed on the top surface 943, the power generator of the first flat surface 943a, the protruding portion 943b, and the second flat surface 943c. When water stagnates on the layer 35 side, it can be promoted that the stagnant water contacts the stagnant water on the surface of the separator 70 and moves to the surface side of the separator 70. Accordingly, it is possible to improve the drainage of the staying water. Moreover, since the notches 943d and 943e penetrate to the separator 70 side, the staying water staying on the power generator layer 35 side of the first flat surface 943a, the protruding portion 943b, and the second flat surface 943c It becomes very easy to move to the surface side of 70, and the discharge property can be further improved. Furthermore, the accumulated water is guided to the surface of the separator 70 and discharged, thereby suppressing variations in the accumulated state of the accumulated water in the fuel cell 20 and among the plurality of fuel cells 20 and suppressing the gas pressure loss from varying. can do. As a result, the supply and discharge of the reaction gas can be made uniform in the surface direction of the power generation body layer 35 and between the fuel cells 20, and the power generation efficiency can be improved. It is not essential that the notches 943d and 943e are formed to penetrate to the separator 70 side.

G. Modifications:
A modification of the above embodiment will be described.
G-1. Modification 1:
In the above-described embodiment, the gas flow passage layer having the configuration according to the embodiment of the present invention is provided on both sides (the cathode electrode 32a side and the anode electrode 32b side) of the power generation body layer 35. The gas flow path layer may be used only on either the cathode electrode 32a side or the anode electrode 32b side. Similarly, the separator having the protruding portion shown as the fifth embodiment may be provided only on either the cathode electrode 32a side or the anode electrode 32b side. Of course, the gas flow path layer may be provided only on either the cathode electrode 32a side or the anode electrode 32b side.

G-2. Modification 2:
In the above-described embodiment, the top surface of the gas flow path layer is provided with a flat surface parallel to the laminated surface of the separator, and the gap is mainly formed between the flat surface and the separator. Is not necessarily formed between the flat surface and the separator. Even if the gas flow path layer does not have a flat surface, it is sufficient that a gap penetrating at least substantially in the first direction D1 is formed between at least one of the convex portions of the gas flow path layer and the separator. For example, if the convex portion 161 of the metal lath 160 shown in the first embodiment is configured so that a relatively high height and a low height in the convex direction are mixed and used as a gas flow path member, Therefore, a gap can be formed between the low protrusion 161 and the separator. Even if it does in this way, the effect which connects the stagnant water between flow paths CH1 and improves discharge property can be expected to some extent.

G-3. Modification 3:
In the above-described embodiment, the plurality of corrugated elements WSE provided in the gas flow path member includes a part of the top surface of the convex portion in one corrugated element WSE and the bottom surface of the concave portion in the corrugated element WSE adjacent to the corrugated element WSE. However, it may be configured such that the entire top surface of the convex portion and the entire bottom surface of the concave portion form an integral surface. Of the top surface of the convex part and the bottom surface of the concave part, one of all and one part may form an integral surface.

  As mentioned above, although embodiment of this invention was described, elements other than the element described in the independent claim among the components of this invention in embodiment mentioned above are additional elements, and are suitably abbreviate | omitted or combined. Is possible. In addition, the present invention is not limited to such an embodiment, and it is needless to say that the present invention can be implemented in various modes without departing from the gist of the present invention. For example, the present invention is not limited to the polymer electrolyte fuel cell shown in the embodiments, but can be applied to various fuel cells such as a direct methanol fuel cell and a phosphoric acid fuel cell.

20 ... Fuel cells 30a, 71a, 95a ... Hydrogen supply manifolds 30b, 71b, 95b ... Air supply manifolds 30c, 71c, 95c ... Hydrogen discharge manifolds 30d, 71d, 95d ... Air discharge manifolds 30e, 71e, 95e ... Cooling water supply manifolds 30f, 71f, 95f ... Cooling water discharge manifold 31 ... Electrolyte membrane 32a ... Cathode electrode 32b ... Anode electrode 33a, 33b ... Gas diffusion layer 34 ... MEA
35 ... Power generation layer 36 ... Seal gasket 40, 60, 440, 540, 640, 740, 840, 940 ... Gas flow path layer 41, 841 ... Projection 41a, 441a, 541a, 641a, 741a, 941a ... First Convex part 41b, 441b, 541b, 641b, 741b, 941b ... second convex part 42, 442, 542, 742 ... concave part 43, 643, 943 ... top face 43a, 643a, 743a, 943a ... first flat face 43b , 443b, 543b, 643b, 943b... Projections 43c, 443c, 543c, 643c, 743c, 843c, 943c ... Second flat surface 44, 644, 944 ... Bottom surface 60 ... Gas flow path layer 70, 80 ... Separator 71 ... Cathode side separator 72 ... Intermediate separator 72a ... Hydrogen communication hole 72b ... Air communication hole 73 Anode side separator 75, 76 ... Air communication hole 95 ... End plate 100 ... Fuel cell stack 150 ... Base material 160 ... Metal lath 170 ... Processed metal lath 161, 171 ... Convex part 162, 172 ... Concave part 173, 174 ... Flat surface 200 ... Lath cut Processing device 210, 220 ... Roller 230 ... Lower blade 240 ... Upper blade 231, 241 ... Convex portion 232, 242 ... Concavity 233, 243 ... Shear blade 300 ... Roll press device 310, 320 ... Roller 330 ... Stage 870 ... Separator 871 ... Protruding portion 943d ... Notch D1 ... First direction D2 ... Second direction G1-G3, G41-G43, G51, G61, G64, G65, G71, G81, G84, G85 ... Gap TH ... Through hole CH1-CH4 ... Flow path WSE ... Waveform element

Claims (15)

A fuel cell,
A power generation layer provided with an electrolyte membrane;
A pair of separators arranged with the power generation layer interposed therebetween;
A gas flow path layer disposed between the power generation body layer and at least one of the pair of separators and serving as a flow path for a reaction gas to be used for a power generation reaction in the power generation body layer, on the separator side A plurality of corrugated elements having a corrugated cross-section in which convex convex portions and concave portions concave on the separator side are alternately arranged along the first direction are provided along a second direction substantially orthogonal to the first direction. And at least a part of the top surface of the convex part in one of the corrugated elements forms a surface integral with at least a part of the bottom surface of the concave part in the adjacent corrugated element, and the corrugated element A gas flow path layer having a plurality of through holes formed therebetween,
Between at least a part of the top surface of the specific convex portion, which is at least one convex portion of the plurality of convex portions constituting the plurality of waveform elements, and substantially in the second direction. A fuel cell with a gap formed.   The fuel cell according to claim 1, wherein at least one of the gaps is formed so as to penetrate substantially in the first direction. The fuel cell according to claim 1 or 2, wherein
The top surface of the specific convex portion includes a flat surface parallel to the separator,
The gap is a fuel cell formed between the separator and the flat surface. A fuel cell according to any one of claims 1 to 3,
The separator provided adjacent to the gas flow path layer includes a first protrusion that protrudes toward the gas flow path layer at a position corresponding to at least one of the plurality of protrusions. ,
The first protrusion and the top surface of the protrusion at a position corresponding to the first protrusion,
The fuel cell in which the gap is formed between the top surfaces of the plurality of convex portions and the separator in a region where the first protrusion is not formed. A fuel cell according to any one of claims 1 to 3,
The top surface of at least one of the plurality of protrusions is formed with a second protrusion that protrudes toward the separator with respect to the top surface of the other protrusion.
The second protrusion and the separator abut,
The fuel cell in which the gap is formed between a region of the plurality of protrusions where the second protrusion is not formed and the separator. A fuel cell according to any one of claims 1 to 3,
The convex portion includes a first convex portion having a relatively high height in the convex direction of the top portion of the convex portion, and a second convex portion as the specific convex portion that is relatively low,
The top of the first convex part and the separator abut,
A fuel cell in which the gap is formed at least between the top of the second protrusion and the separator. The fuel cell according to claim 1, wherein
Each of the top surfaces of the plurality of convex portions includes a flat surface parallel to the separator,
The flat surface protrudes from the flat surface toward the separator, and includes a first flat surface formed with a third protrusion that contacts the separator, and a second flat surface that does not include the third protrusion. Including
The gap is formed between the separator and the first flat surface excluding the region where the third projecting portion is formed, and the first gap penetrating in the substantially second direction; and the separator And a second gap formed between the first flat surface and substantially the first direction and the second direction. The fuel cell.   The said gap | interval was formed along with the said substantially 2nd direction between each of the said some convex part located in a line in the said substantially 2nd direction, and the said separator. 8. The fuel cell according to any one of 7 above.   The plurality of corrugated elements are formed such that only a part of the top surface of the convex portion in the one corrugated element and only a part of the bottom surface of the concave portion in the adjacent corrugated element form an integral surface. The fuel cell according to any one of claims 1 to 8.   The plurality of recesses arranged adjacent to each other in the substantially second direction are arranged in a second direction different from the first direction, and a first recess group composed of the plurality of recesses arranged in the first direction. The fuel cell according to claim 9, wherein the fuel cell is configured by a plurality of second recess groups formed of the recesses.   The notch part by which the part of this top part was notched to the outer edge of the said separator side of the said top surface provided with the said flat surface was formed in the said electric power generation body layer side of the top part of the said convex part. Alternatively, the fuel cell according to claim 7.   The fuel cell according to claim 11, wherein the notch has a shape that penetrates from the power generator layer side to the separator side of the flat surface. A flow path member that forms a flow path of a gas related to a power generation reaction of a fuel cell,
A corrugated element having a corrugated cross-section in which convex portions convex in a predetermined direction and concave portions concave in the predetermined direction are alternately arranged along the first direction is a second shape substantially orthogonal to the first direction. A plurality of lines are arranged along the direction,
At least a part of the top surface of the convex part in one corrugated element forms a surface integral with at least a part of the bottom surface of the concave part in the adjacent corrugated element, and a plurality of gaps between the corrugated elements A through hole is formed,
The height in the convex direction of the top part of at least one convex part among the plurality of convex parts constituting the plurality of waveform elements is the height of the convex part in the top part of the other convex part among the plurality of convex parts. Channel member different from height. A separator used in a fuel cell,
The fuel cell
A power generation layer provided with an electrolyte membrane;
A pair of the separators disposed with the power generating layer interposed therebetween;
A gas flow path layer disposed between the power generation body layer and at least one of the pair of separators and serving as a flow path for a reaction gas to be used for a power generation reaction in the power generation body layer, on the separator side A plurality of corrugated elements having a corrugated cross-section in which convex convex portions and concave portions concave on the separator side are alternately arranged along the first direction are provided along a second direction substantially orthogonal to the first direction. And at least a part of the top surface of the convex part in one of the corrugated elements forms a surface integral with at least a part of the bottom surface of the concave part in the adjacent corrugated element, and the corrugated element A gas flow path layer having a plurality of through holes formed therebetween,
The separator provided with the protrusion part which protruded in this gas flow path layer side in the position corresponding to the said at least 1 said convex part among these convex parts. A separator used in a fuel cell,
A separator having a substantially flat flat portion and a protruding portion that protrudes in a direction intersecting the stacked surface from the flat portion and is scattered on the stacked surface.

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