JP2000082482A - Gas separator for fuel cell and the fuel cell, and gas distributing method for fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent flow rate of gas passing through each cell from becaming nonuniform, resulting in deterioration of cell performance. SOLUTION: A separator 30 has holes 40, 41, 42 and recesses 90, 91 formed on one face. These recesses define an in-cell oxidizing gas flow passage in a space to an anode. Oxidizing gas to be supplied from the outside to a fuel cell is distributed from a oxidizing gas supply manifold defined by the hole 40, passing through the in-cell oxidizing gas flow passage defined by the recesses 90, 91 collected in an oxidizing gas exhaust manifold defined by the hole 42 and exhausted to the outside. In this case, the oxidizing gas passing through the in-cell oxidizing gas flow passage is passed via an oxidizing gas distributing manifold formed by the hole 41.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas separator for a fuel cell, a fuel cell, and a gas distribution method in a fuel cell. More particularly, the present invention relates to a fuel cell comprising a plurality of stacked single cells. Provided in
A fuel cell flow path and an oxidizing gas flow path are formed between adjacent members, and a fuel cell separator that separates the fuel gas and the oxidizing gas, and a fuel cell using the separator, and a gas flow in the fuel cell. Related to distribution method.

[0002]

2. Description of the Related Art A gas separator for a fuel cell is a member constituting a fuel cell stack in which a plurality of single cells are stacked, and is provided with sufficient gas impermeability to supply each of the adjacent single cells. The fuel gas and the oxidizing gas are prevented from being mixed. Such a separator for a fuel cell usually has an uneven structure such as a rib shape on the surface, and also has a function of forming a flow path for the fuel gas and the oxidizing gas (the gas separator having such a configuration). Is also referred to as a ribbed interconnector). That is, when the fuel cell separator is incorporated into a fuel cell stack, a fuel gas or oxidizing gas flow path (gas flow path within a single cell) is provided between an adjacent member (gas diffusion layer) and the uneven structure. To form

[0003] A gas separator for a fuel cell usually has a predetermined hole structure in addition to the concavo-convex structure for forming the gas flow path described above. When a single cell including such a gas separator is stacked to form a fuel cell stack, the corresponding hole structures provided in adjacent gas separators overlap with each other, and these hole structures cause the fuel cell stack to move inside the fuel cell stack. A gas manifold penetrating in the stacking direction is formed. Such a gas manifold distributes a fuel gas or an oxidizing gas supplied from the outside of the fuel cell to each single cell while passing the inside thereof, or a fuel exhaust gas after being subjected to an electrochemical reaction in each single cell. Alternatively, oxidized exhaust gases are collected and discharged out of the fuel cell. Therefore, the gas manifold formed by the above-mentioned hole structure communicates with the above-mentioned single-cell gas flow path (single-cell oxidizing gas flow path or single-cell fuel gas flow path) formed in each stacked single cell. The gas can flow in and out between the gas manifold and the flow path in the single cell.

FIG. 18 is an explanatory diagram showing a plan view of the structure of a separator 930 as an example of a conventionally known gas separator for a fuel cell. The separator 930 includes four holes 940, 942, and four holes near its periphery.
950, 952. When a fuel cell is constructed by stacking a plurality of single cells made of a member including the separator 930, these holes are adjacent to the separator 930.
The corresponding holes provided in the fuel cell overlap with each other, and inside the fuel cell, the oxidizing gas supply manifold (distributes the oxidizing gas supplied from the outside to the oxidizing gas flow path in each single cell) and the oxidizing gas discharge manifold ( The oxidizing exhaust gas discharged from the oxidizing gas flow path in each unit cell is collected and led to the outside of the fuel cell), and the fuel gas supply manifold (the fuel gas supplied from the outside is distributed to the fuel gas flow path in each unit cell) ,
A fuel gas discharge manifold (collecting and guiding the fuel exhaust gas discharged from the fuel gas passages in each single cell to the outside of the fuel cell) is formed.

[0005] On one surface of the separator 930,
A concave portion 990 for communicating the hole portion 940 and the hole portion 942 is provided, and a concave portion (not shown) for communicating the hole portion 950 and the hole portion 952 is provided on the other surface of the separator 930. . Each of these recesses has a groove-like structure having two bent portions in the middle. Separator 930
When a fuel cell is configured by laminating members including the following, these concave portions form a gas flow path within a single cell with a member adjacent to the separator 930. That is, the hole 94
The concave portion 990 that connects the hole 0 and the hole 942 forms an oxidizing gas flow path in the single cell, and the concave portion that connects the hole 950 and the hole 952 forms a fuel gas flow path in the single cell. The oxidizing gas supplied to the fuel cell passes through the oxidizing gas supply manifold formed by the holes 940, is distributed to the oxidizing gas flow paths in the single cells formed in each single cell, and is supplied to the electrochemical reaction. After that, they are joined by the oxidizing gas discharge manifold formed by the holes 942 and discharged outside the fuel cell. Similarly, the fuel gas supplied to the fuel cell passes through the fuel gas supply manifold formed by the holes 950, is distributed to the fuel gas flow paths in the single cells formed in each single cell, and After being subjected to the reaction, they are joined by a fuel gas discharge manifold formed by the holes 952 and discharged outside the fuel cell.

In particular, in the separator 930 shown in FIG. 18, since the concave portion provided on each surface of the separator 930 is bent by one reciprocation and a half, the shape bent in this manner is used. As compared with the case where no gas flow is performed, the cross section of the gas flow path in the single cell becomes smaller, and the flow velocity of the gas passing through an arbitrary portion of the flow path can be further increased. Therefore, the gas passing through the gas flow path in the single cell is more well stirred and diffused in the flow path. In such a state, the electrode active material (hydrogen or oxygen) in the gas (fuel gas or oxidizing gas) easily comes into contact with the catalyst layer provided on the electrode, and the electrode active material becomes electrochemically active. Easier to use in reactions,
Gas utilization is improved.

In addition to the configuration shown in FIG. 18, as the shape of the concave portion provided on the surface of the gas separator for a fuel cell, a concave portion bent by one reciprocation and a half as described above is formed in parallel on the same plane. And a plurality of recesses on the same surface are supplied and supplied with gas through a pair of gas introduction holes and gas discharge holes forming a gas supply manifold and a gas discharge manifold. (For example, JP-A-7-263003). With such a configuration, by providing a plurality of concave portions having a bent shape on the same plane, the cross section of the gas flow path in the single cell is further reduced, and the gas passing through an arbitrary location in the flow path is reduced. Since the flow rate of the gas becomes higher, the gas utilization rate in the fuel cell can be further improved.

[0008]

However, in the gas separator for a fuel cell disclosed in the above-mentioned FIG. 18 and the gazette, the gas flow path in the single cell provided in each single cell has The holes through which the supplied gas passes (the holes 940 and 950 in FIG. 18) and the holes through which the gas discharged from the single cell gas flow path passes (the holes 942 and 952 in FIG. 18). However, since there is only one each, there is a problem that the gas distribution to each single cell constituting the fuel cell may be non-uniform. For example, when water generated due to the electrochemical reaction condenses in the gas flow path, the condensed water flows around the connection between the gas manifold and the gas flow path in the single cell or the gas flow in the single cell. If the condensed water stays in the passage, resistance to the gas flow occurs in the gas flow path in the single cell corresponding to the portion where the condensed water stays, and the gas flow is hindered. In the unit cell in which the supply state of the gas is deteriorated, the electrochemical reaction does not sufficiently proceed, so that the output voltage varies among the unit cells in the entire fuel cell, and the performance of the fuel cell is reduced. There is a risk.

Here, the condensed water generated in the gas passage will be described. Condensed water generated in the flow path of the oxidizing gas is caused by water generated on the cathode side due to the electrochemical reaction. Hereinafter, an electrochemical reaction that proceeds in each unit cell of the polymer electrolyte fuel cell will be described.

H ₂ → 2H ⁺ + 2e ⁻ (1) (1/2) O ₂ + 2H ⁺ + 2e ⁻ → H ₂ O (2) H ₂ + (1/2) O ₂ → H ₂ O (3) )

Equation (1) describes the reaction on the anode side,
Equation (2) shows the reaction on the cathode side, and the reaction shown in equation (3) proceeds for the whole battery. As described above, in the polymer electrolyte fuel cell, generated water is generated on the cathode side as the cell reaction proceeds. The generated water evaporates into the oxidizing gas supplied to the cathode side and is discharged out of the fuel cell together with the oxidizing gas.However, when the amount of generated water is large or partially in the flow path where the oxidizing gas flows, If there is a region where the temperature is low, the generated water may condense in the flow path of the oxidizing gas, and the condensed water may stay in the flow path.

On the anode side, no water is produced due to the electrochemical reaction, but the fuel gas supplied to the anode side is usually humidified before being supplied to the fuel cell. That is, when the reaction represented by the above formula (1) proceeds on the anode side, the generated protons move toward the cathode side in the solid electrolyte membrane in a state of being hydrated with water molecules. Although there is a shortage of water on the anode side, drying the solid electrolyte lowers the conductivity of the solid electrolyte. Prevents drying out. Therefore, the water vapor added to the fuel gas may condense in the fuel gas flow path. Thus, the condensed water generated in the flow path of the oxidizing gas or the flow path of the fuel gas stays,
If the supply state of the gas in some of the single cells deteriorates, the performance of the entire fuel cell may deteriorate.

Further, the problem that the output voltage varies between the individual cells constituting the fuel cell is caused not only by the above-mentioned condensed water but also by the accuracy in forming the gas separator for the fuel cell. May occur. In the case where the accuracy of molding is insufficient in the uneven structure formed on the surface of the gas separator to form the gas flow path, that is, when the depth of the formed unevenness varies, For each cell, the flow path resistance when the gas passes through the gas flow path within the single cell varies, and the amount of gas supplied to each single cell varies. Therefore, in a fuel cell using a conventionally known gas separator, the output voltage varies among the individual cells due to the accuracy in forming the gas separator, and the performance of the entire fuel cell may be deteriorated. there were.

The gas separator for a fuel cell, the fuel cell, and the gas distribution method in the fuel cell according to the present invention solve these problems, and the flow rate of gas passing through each unit cell becomes nonuniform, thereby deteriorating the cell performance. This is done for the purpose of preventing this from happening, and has the following configuration.

[0015]

The fuel cell according to the present invention comprises a plurality of unit cells stacked one on another, and in each unit cell, an electromotive force is generated by an electrochemical reaction utilizing gas. And a gas flow path in the single cell, which is provided continuously in each of the single cells, and allows the gas to pass therethrough so as to spread the gas into the single cells, and flows in from outside the fuel cell. Distributing the gas
A gas supply manifold for supplying each of the single-cell gas flow paths, a gas discharge manifold for collecting the gas discharged from each of the single-cell gas flow paths, and allowing the gas to flow out of the fuel cell; A gist of the present invention includes a distribution manifold that penetrates each of the gas flow paths in the single cell in the stacking direction of the single cells, and enables the gas to flow between the gas flow paths in the single cell.

The fuel cell of the present invention configured as described above is formed by stacking a plurality of single cells, and a gas supplied from outside of the fuel cell is distributed by the gas supply manifold, and the gas is supplied into each single cell. Supply to gas flow path. The gas flow path in the single cell provided in each single cell allows the supplied gas to pass therethrough and distributes the gas into each single cell. In each single cell, an electromotive force is obtained by an electrochemical reaction using this gas. The fuel cell further includes a distribution manifold that penetrates each of the gas passages in the single cell in the stacking direction of the single cells, and enables the gas to flow between the gas passages in the single cell. The gas passes through the distribution manifold when passing through each single cell gas flow path. The gas discharged from each of the single-cell gas flow paths is collected in a gas discharge manifold and discharged to the outside of the fuel cell.

Further, the gas distribution method in a fuel cell according to the present invention comprises a plurality of single cells stacked, receives a supply of the gas, and obtains an electromotive force by an electrochemical reaction utilizing the gas. (A)
(B) distributing the gas supplied from outside the fuel cell to a gas flow path in a single cell formed inside each single cell via a gas supply manifold provided in the fuel cell; (C) providing, in each of the single cells, the gas distributed from the gas supply manifold to the electrochemical reaction progressing in each of the single cells while passing the gas through the gas passage in the single cell; The gas discharged from each of the gas channels in the single cell after being subjected to the electrochemical reaction is collected in a gas discharge manifold provided in the fuel cell, and the collected gas is discharged outside the fuel cell. (B-1) in the step (b), wherein in each of the single cells, at least a part of the gas passing through the gas flow path in the single cell is disposed inside the fuel cell. And summarized in that further comprising the step of through flow distribution manifold disposed through the stacking direction of the unit cells.

According to the fuel cell of the present invention and the gas distribution method in the fuel cell of the present invention, the gas passing through the gas passage in the single cell passes through the distribution manifold. In any one of the constituent single cells, it is possible to prevent the output voltage from being lowered due to the deterioration of the gas supply state, and the performance of the entire fuel cell from being lowered. That is, in any one of the single cells, even when the flow resistance of the gas flowing into the gas flow path in the single cell increases due to stagnation of condensed water or the like and the gas supply state is deteriorated, Since the gas passing through the gas flow path passes through the distribution manifold, it is possible to secure a sufficient gas supply amount in the single-cell gas flow path downstream of the connection portion with the distribution manifold. . Therefore, even if the condensed water stays, the gas supply state does not deteriorate in the entire single cell in which the condensed water stays.

Further, according to the fuel cell of the present invention and the gas distribution method in the fuel cell of the present invention, the gas passing through each gas passage in the single cell passes through the distribution manifold. As a whole, there is an effect that the flow rate (or flow rate) of the gas passing through each of the gas flow paths in the single cell can be made uniform. In the distribution manifold, gas can flow between the gas flow paths in each single cell. You. Further, inside the fuel cell, the gas flow rate passing through each single cell is set to a predetermined value according to the flow direction of the gas supplied / exhausted from the outside (the flow direction of the gas passing through the gas discharge manifold). Is generated. The fuel cell of the present invention, and, as in the gas distribution method in the fuel cell of the present invention, by providing a distribution manifold to equalize the gas flow rate passing through each single-cell gas flow path, the gradient described above is reduced. Therefore, the gas flow rate can be sufficiently ensured in each single cell constituting the entire fuel cell, and the amount of electrochemical reaction progressing in each single cell can be maintained at a high level. .

The fuel cell of the present invention may include a plurality of the distribution manifolds. With this configuration, it is possible to reduce the influence of obstruction of gas supply in a predetermined single cell due to condensed water and the like, and to make the flow rate of gas passing through the gas flow path in each single cell uniform. Effect can be further enhanced.

In the fuel cell according to the present invention, the gas is:
It may be a fuel gas containing hydrogen. With such a configuration, the above-described effects can be obtained in the fuel gas flow path formed in the fuel cell, and the cell performance (stable output voltage) of the fuel cell can be maintained sufficiently high. it can.

In the fuel cell according to the present invention, the gas may be an oxidizing gas containing oxygen. With such a configuration, the above-described effect can be obtained in the flow path of the oxidizing gas formed in the fuel cell, and the cell performance (stable output voltage) of the fuel cell can be maintained sufficiently high. it can.

The gas separator for a fuel cell according to the present invention is used in a fuel cell having a plurality of unit cells stacked, and is a gas separator for a fuel cell which constitutes the unit cell together with a member forming an electrolyte layer and an electrode. Three or more holes, each of which is provided so as to penetrate the fuel cell gas separator in the thickness direction thereof and form a part of a gas manifold of the fuel cell, and one of the fuel cell gas separators; Of the three or more holes, from the predetermined first hole to the predetermined second hole, communicating with the surface while sequentially passing through the holes other than the first and second holes. And a concave portion for forming a gas flow path in the single cell.

Such a gas separator for a fuel cell comprises:
It has three or more holes penetrating in its thickness direction, forms a single cell together with a member forming an electrolyte layer and an electrode, and is used for a fuel cell configured by stacking a plurality of single cells . When a fuel cell is constructed using the gas separator for a fuel cell of the present invention, the three or more holes respectively form a gas manifold of the fuel cell. The gas separator for a fuel cell according to the present invention may further include, on one surface thereof, the first and second holes from a predetermined first hole to a predetermined second hole of the three or more holes. It has a concave portion that communicates with the surface while sequentially passing through holes other than the hole. When a fuel cell is configured using the gas separator for a fuel cell of the present invention, the recess forms a gas flow path in a single cell with an adjacent member. Further, the gas flow path in the single cell formed by the concave portion communicates with the gas manifold formed by each of the three or more holes. In such a fuel cell, when gas is supplied from outside the fuel cell to the gas manifold formed by the predetermined first hole, the supplied gas is
The gas is distributed from the gas manifold to the gas channels in each single cell. At this time, the gas discharged through the gas flow path in the single cell is collected in the gas manifold formed by the predetermined second hole, and can be discharged to the outside of the fuel cell. When the gas passes through the gas flow path in the single cell as described above, the gas passes through a gas manifold formed by holes other than the first and second holes.

According to such a fuel cell gas separator, a fuel cell similar to the fuel cell of the present invention can be constructed, and the same effect as that of the fuel cell of the present invention can be obtained in such a fuel cell. be able to. Therefore, by using the gas separator for a fuel cell of the present invention, in any one of the single cells constituting the fuel cell, the output voltage is reduced due to the deterioration of the gas supply state, and the performance of the entire fuel cell is reduced. It is possible to configure a fuel cell that is not likely to be damaged. Further, by using the gas separator for a fuel cell of the present invention, the flow rate of the gas passing through the gas flow path in each single cell is made uniform, and the flow rate of the gas in each single cell constituting the entire fuel cell is sufficiently increased. And a fuel cell capable of maintaining the amount of electrochemical reaction progressing in each single cell at a high level.

The concave portion formed on the surface of the fuel cell gas separator of the present invention does not need to have a flat concave surface, but may have a convex portion projecting from the concave surface. From the first hole to a predetermined second hole, the first
Any structure may be used as long as the structure allows the gas separator for the fuel cell to communicate with the surface while sequentially passing through the holes other than the second hole.

In the fuel cell according to the present invention, the gas flow path in the single cell has a bent portion in which the flow path is bent so as to change the direction of the flow of the gas passing through the inside, and the bent portion has The first through which the distribution manifold penetrates
And a second region that allows a part of the gas passing through the inside of the bent portion to pass without passing through the distribution manifold.

In such a fuel cell, a part of the gas passing through the gas passage in the single cell passes through the distribution manifold when passing through the bent portion where the gas passage in the single cell is bent. The rest does not go through the distribution manifold. By providing the second region that does not pass through the distribution manifold in this manner, a sufficient flow path width can be secured in the bent portion through which the distribution manifold penetrates, and the pressure loss when gas passes through the bent portion is reduced. And the gas flow can be made smoother.

Further, in the gas separator for a fuel cell according to the present invention, the concave portion is formed in the middle of connecting the predetermined first hole to the second hole on one surface of the fuel cell gas separator. A bent portion bent on the one surface, wherein the bent portion has a first region through which one of the holes other than the first and second holes penetrates, and the first region penetrates the first region. A second region in which the bottom surface of the concave portion is formed continuously without being divided by the hole may be provided.

According to the gas separator for a fuel cell configured as described above, a fuel cell similar to the above-described fuel cell can be configured. In such a fuel cell,
The same effects as those of the above-described fuel cell can be obtained.

In the above-described fuel cell, the bent portion may have a U-shape. By forming the bent portion in a U-shape, the gas flow path in the single cell can be effectively arranged in each single cell and the gas flow rate passing through the flow path can be increased, but the U-shape is formed. In the bent portion, the pressure loss is particularly increased by changing the direction of the gas flow in the opposite direction. With the above configuration, the effect of reducing the pressure loss and smoothing the gas flow can be obtained particularly remarkably. Can be.

Further, in the fuel cell according to the present invention, the gas flow path in the single cell has a bent portion where the flow path is bent so as to change a flow direction of the gas passing through the inside thereof. The outer periphery of the portion may be formed to be smoothly curved, and the distribution manifold may penetrate the gas flow path in the single cell at the outer periphery of the bent portion.

According to this structure, the gas passing through the gas flow path in the single cell is guided to the smoothly curved outer periphery in the bent portion and flows therethrough. The effect that the flow becomes smoother is obtained.

Further, in the fuel cell according to the present invention, the gas flow path in the single cell has a bent portion where the flow path is bent so as to change the flow direction of the gas passing therethrough. Near the outer edge, the distribution manifold is provided near the outer edge of the fuel cell,
In the outer peripheral portion of the bent portion, penetrates the gas flow path in the single cell, a cross-sectional shape of the distribution manifold forms a vertically long shape along an outer edge of the fuel cell, and the fuel cell outer edge side in the distribution manifold Of the inner wall surfaces, the inner wall surface corresponding to the end portion of the cross-sectional shape forming the vertically long shape has a greater thickness from the outer edge of the fuel cell than the inner wall surface corresponding to the center portion of the cross-sectional shape. It may be.

According to such a fuel cell, the strength and durability of the fuel cell can be sufficiently ensured. The distribution manifold is provided near the outer edge of the fuel cell, and the cross-sectional shape of the distribution manifold is vertically long along the outer edge of the fuel cell. By providing the distribution manifold, a region that can participate in an electrochemical reaction in each single cell. Can be suppressed, and it becomes easy to secure gas sealing properties in the distribution manifold. However, at the above-mentioned bent portion through which the distribution manifold penetrates, the direction of gas flow changes,
A strong stress acts between the inner wall surface of the distribution manifold and the outer edge of the fuel cell. This stress is concentrated particularly in a region corresponding to the end of the cross section of the distribution manifold formed in a vertically long shape, and the strength of this region may affect the strength of the entire fuel cell. With the above configuration of the fuel cell, it is possible to sufficiently secure the strength of a region where a strong stress is exerted by the gas passing through the bent portion, and thereby to sufficiently secure the strength of the entire fuel cell. Becomes possible.

Also, in the gas separator for a fuel cell according to the present invention, the recess may be formed in the middle of connecting the predetermined first hole to the second hole on one surface of the fuel cell gas separator. A bent portion bent on the one surface is provided near an outer edge of the fuel cell gas separator, and one of the holes other than the first and second holes is an outer edge of the fuel cell gas separator. The fuel cell gas separator is disposed in the vicinity and forms a vertically long shape along the outer edge of the fuel cell gas separator, and at the outer peripheral portion of the bent portion, penetrates the concave portion and forms the hole. In the wall surface located on the outer edge side of the gas separator for a fuel cell, a portion corresponding to an end of the hole having a vertically long shape has a larger distance from an outer edge of the gas separator for a fuel cell than a portion corresponding to a central portion. It may be characterized in that it is formed so as to be.

According to the gas separator for a fuel cell configured as described above, a fuel cell similar to the above-described fuel cell can be configured. In such a fuel cell,
The same effects as those of the above-described fuel cell can be obtained.

[0038]

DESCRIPTION OF THE PREFERRED EMBODIMENTS In order to further clarify the structure and operation of the present invention described above, embodiments of the present invention will be described below based on examples. The fuel cell according to the first embodiment of the present invention is a polymer electrolyte fuel cell and has a stack structure in which a plurality of single cells are stacked. FIG.
Is a stack structure 15 constituting the fuel cell of the first embodiment.
FIG. 2 is an exploded perspective view showing a configuration of a single cell 20 which is a basic unit of FIG.
FIG. 3 is a perspective view showing an appearance of the stack structure 15. First, the configuration of the fuel cell will be described with reference to FIGS. 1 to 3, and then the flow of gas in the fuel cell will be described.

As described above, the fuel cell of this embodiment is
This is a polymer electrolyte fuel cell, and is constituted by a stack structure 15 in which unit cells 20 as basic units are stacked. As shown in FIG. 1, the single cell 20 includes an electrolyte membrane 31,
It comprises an anode 32, a cathode 33, and a separator 30.

Here, the electrolyte membrane 31 is a proton-conductive ion-exchange membrane formed of a solid polymer material, for example, a fluorine-based resin, and has good electric conductivity in a wet state. In this embodiment, a Nafion membrane (manufactured by DuPont) is used.
It was used. The surface of the electrolyte membrane 31 is coated with platinum as a catalyst or an alloy composed of platinum and another metal. As a method of applying the catalyst, a carbon powder supporting platinum or an alloy of platinum and another metal is prepared, and the carbon powder supporting the catalyst is dispersed in an appropriate organic solvent, and an electrolyte solution (for example, Aldrich Chemi) is prepared.
Cal Co., Nafion Solution) was added in an appropriate amount to form a paste, and screen printing was performed on the electrolyte membrane 31. Alternatively, a configuration is also preferable in which a sheet containing carbon powder supporting the catalyst is formed into a film to form a sheet, and the sheet is pressed on the electrolyte membrane 31.

Each of the anode 32 and the cathode 33 is a gas diffusion electrode formed of a carbon cloth woven with carbon fiber yarn. In addition, other than carbon cloth, it may be formed of carbon paper or carbon felt made of carbon fiber, as long as it has sufficient gas diffusivity and conductivity.

The separator 30 is formed of a gas-impermeable conductive member, for example, formed carbon which is made by compressing carbon to be gas-impermeable. FIG. 2 shows the separator 3
FIG. 2 is a plan view illustrating a state of the “0” as viewed from one surface thereof.
The separator 30 has six holes near its periphery. That is, in the vicinity of one side of the separator 30, the holes 40, 41, 4 which are three holes adjacent along this side are provided.
2 is provided, and in the vicinity of a side opposite to this side,
Similarly, adjacent holes 50, 51, and 52 are provided. Further, the separator 30 is provided with a concave portion having a predetermined shape on both surfaces thereof. As shown in FIG. 2, on one surface of the separator 30, a concave portion 90 communicating the holes 40 and 41 with a bent shape, and a concave portion communicating the holes 41 and 42 with the same bent shape. 91 are provided. Similarly to the above-mentioned one surface, the other surface of the separator 30 communicates the concave portion 92 communicating the hole portion 50 and the hole portion 51 with the bent shape, and communicates the hole portion 51 and the hole portion 52 with the same bent shape. A recess 93 is provided (not shown).

As shown in FIG. 1, when the separator 30 is laminated with the electrolyte membrane 31, the anode 32, and the cathode 33 to form the single cell 20, and when the stack structure 15 is formed, each recess is formed by the adjacent gas diffusion. A gas flow path is formed between the electrodes. That is, the holes 40 and 4
1, and recesses 90 and 91 for communicating holes 41 and 42 form an oxidizing gas flow path in a single cell between the adjacent cathode 33 and the surfaces of holes 50 and 51 and hole 5.
Recesses 92 and 93 connecting 1 and 52 form a fuel gas flow path in a single cell with the surface of the adjacent anode 32.

When the stack structure 15 is assembled by stacking the single cells 20, the hole 4
No. 0 forms an oxidizing gas supply manifold 60 penetrating the inside of the stack structure 15 in the stacking direction. The hole 41 also forms an oxidizing gas distribution manifold 61 that also passes through the inside of the stack structure 15 in the stacking direction. The hole 42 also forms an oxidizing gas discharge manifold 62 that also passes through the inside of the stack structure 15 in the stacking direction. Further, the hole 50 is provided with a fuel gas supply manifold 63 which also passes through the stack structure 15 in the stacking direction.
The hole 51 forms a fuel gas distribution manifold 64 and the hole 52 forms a fuel gas discharge manifold 65 (see FIG. 2). The gas flow in these gas channels formed in the stack structure 15 will be described later in detail (see FIG. 5 described later).

When assembling the stack structure 15 including the members described above, the separator 30, the anode 32, the electrolyte membrane 31, the cathode 33, and the separator 30 are sequentially stacked in this order. In addition, current collectors 3
6, 37, insulating plates 38, 39, end plates 80, 8
5 are sequentially arranged to complete the stack structure 15 shown in FIG.

The current collecting plates 36 and 37 are formed of a gas-impermeable conductive material such as a dense carbon or copper plate, and the insulating plates 38 and 39 are formed of an insulating material such as rubber or resin. Is formed of a rigid metal such as steel. In addition, the current collector plates 36 and 37 are provided with output terminals 36A and 37A, respectively.
The electromotive force generated in the fuel cell constituted by the stack structure 15 can be output. The current collecting plate 36, the insulating plate 38, and the end plate 80 are provided with four holes at the same corresponding positions. For example, the end plates 80 are provided with holes 70, 72, 73, 75 (see FIG. 3). Hole 70 and current collector 3
The holes provided at the same positions in the insulating plate 6 and the insulating plate 38 correspond to the same when the stack structure 15 is formed.
A gas passage communicating with the oxidizing gas supply manifold 60 described above is formed. The hole 72 and the current collector 36
When the stack structure 15 is formed, the holes provided at the same positions on the insulating plate 38 and the insulating plate 38 form a gas flow path communicating with the oxidizing gas discharge manifold 62 described above. Similarly, the hole 73 and the current collector 36
The holes provided correspondingly to this and the insulating plate 38 form a gas flow path communicating with the fuel gas supply manifold 63, and the hole 75, the current collector plate 36 and the insulating plate 38
The hole provided corresponding to this forms a gas flow passage communicating with the fuel gas discharge manifold 65.

When the fuel cell having the stack structure 15 is operated, the hole 73 provided in the end plate 80 is provided.
And a fuel gas supply device (not shown) are connected to supply a hydrogen-rich fuel gas into the fuel cell. Similarly, when operating the fuel cell, the hole 70 and an oxidizing gas supply device (not shown) are connected, and an oxidizing gas (air) containing oxygen is supplied into the fuel cell. Here, the fuel gas supply device and the oxidizing gas supply device are devices that humidify and pressurize a predetermined amount of each gas and supply the gas to the fuel cell. When operating the fuel cell, the hole 75 is connected to a fuel gas discharge device (not shown), and the hole 72 is connected to an oxidizing gas discharge device (not shown). As the fuel gas, a high-purity hydrogen gas may be used in addition to a hydrogen-rich gas obtained by reforming a hydrocarbon.

The order of lamination of each member when forming the stack structure 15 is as described above, but a predetermined sealing member is provided around the electrolyte membrane 31 in a region in contact with the separator 30. The sealing member serves to prevent the fuel gas and the oxidizing gas from leaking from the inside of each unit cell and to prevent the fuel gas and the oxidizing gas from being mixed in the stack structure 15.

The stack structure 15 composed of the members described above is held in a state where a predetermined pressing force is applied in the stacking direction, and the fuel cell is completed. The configuration for pressing the stack structure 15 is not shown because it does not relate to the main part of the present invention. In order to hold the stack structure 15 while pressing it, the stack structure 15 may be tightened using bolts and nuts, or a stack storage member having a predetermined shape may be prepared, and the stack storage member may be stacked inside the stack storage member. After storing the structure 15, both ends of the stack storage member may be bent to apply a pressing force to the stack structure 15.

In the above description, the separator 30
Is formed of dense carbon which is made gas-impermeable by compressing carbon, but may be formed of a different material. For example, it may be formed of fired carbon or a metal member. When formed of a metal member, it is desirable to select a metal having sufficient corrosion resistance. Alternatively, the surface of the metal member may be coated with a material having sufficient corrosion resistance.

Although not shown in FIG. 2, the separator 30 of this embodiment has holes 40 to 42 for forming a gas manifold through which an oxidizing gas passes and a gas manifold through which a fuel gas passes. In addition to the holes 50 to 52 for forming, holes for forming a cooling water passage through which the cooling water passes are also provided. The electrochemical reaction that proceeds in the fuel cell is an exothermic reaction, and the temperature inside the fuel cell is maintained within a predetermined temperature range by circulating cooling water in a cooling water passage formed by the holes. The holes for forming such cooling water passages can be provided in the separator 30 near, for example, the remaining two sides where the holes 40 to 42 and 50 to 52 are not formed. Since the configuration relating to the cooling water circulation does not directly relate to the main part of the present invention, further description of the cooling water channel is omitted.

In the separator 30 shown in FIGS. 1 and 2, the concave portions 90 and 91 are represented as a concave structure having a flat bottom surface for easy understanding of the gas flow in the single cell. Actually, the concave portions 90 and 91 and the concave portions 92 and 93 are provided with a plurality of convex structures having a predetermined shape protruding from the bottom surfaces thereof. Recesses 90, 9
FIG. 4 shows an example of such a convex structure provided in 1, 92 and 93. FIG. 4A is a plan view illustrating a state in which a part of the hole 40 and the recess 90 is enlarged, and FIG.
FIG. 5 is a cross-sectional view illustrating a state of an AA cross section in FIG. As shown in FIG. 4, the concave portion 90 is provided with a plurality of convex portions 94 protruding from the bottom surface. Each of the convex portions 94 has a substantially rectangular cross section, and is formed so that the heights thereof are substantially the same. When the stack structure 15 is assembled, the end of each projection 94 contacts the adjacent cathode 33, and the region in contact with the cathode 33 ensures sufficient conductivity inside the fuel cell. The oxidizing gas passing through the oxidizing gas flow path in the single cell collides with the side surface of each convex portion 94,
By being diffused in the oxidizing gas flow path in the single cell, it is efficiently supplied to the catalyst layer on the surface of the electrolyte membrane 31.

As described above, the protrusions 9 provided in the recesses 90 are provided.
4 ensures sufficient conductivity by contacting the gas diffusion electrode at the end thereof, and diffuses the gas passing through the gas passage in the single cell formed by the concave portion 90 to efficiently convert the oxidizing gas into an electrochemical gas. It has a function of improving the gas utilization rate by providing for the reaction. Also, the concave portions 91, 92, and 93 are provided with the same convex structure as the convex portion 94 in the concave portion 90, and have the same function. In FIG. 4, the convex portion 94 has a substantially rectangular cross section. However, a convex structure having a different shape may be arranged at a different position. Rather than being dispersed and arranged in each concave portion like the convex portion 94, as a convex structure formed in each concave portion, for example, it is provided continuously along the direction of gas flow in the flow path. It is also possible to form a rib-shaped convex structure and divide each concave portion into fine grooves running parallel to each other. Each of the recesses formed on the separator surface allows gas to flow between gas manifolds formed by holes that allow the respective recesses to communicate with each other when a gas passage in a single cell is formed in the fuel cell. It should just be.

Next, the flow of the fuel gas and the oxidizing gas in the fuel cell having the above configuration will be described. First, the oxidizing gas will be described. FIG. 5 is an explanatory diagram three-dimensionally illustrating the flow of the oxidizing gas in the stack structure 15. As described above, the oxidizing gas supply device provided outside the fuel cell is connected to the hole 70 provided in the end plate 80, and the oxidizing gas (pressurized air) supplied from the oxidizing gas supply device is Insulating plate 38 and current collecting plate 3
6 is introduced into the oxidizing gas supply manifold 60 through the holes provided at the corresponding positions. The oxidizing gas passing through the oxidizing gas supply manifold 60 is
In the above, the gas is guided into a gas flow path (oxidizing gas flow path in a single cell) formed between the concave portion 90 provided in each separator 30 and the adjacent cathode 33. The oxidizing gas guided to the oxidizing gas flow path in the single cell diffuses from the oxidizing gas flow path in the single cell to the catalyst layer on the electrolyte membrane 31 and is subjected to an electrochemical reaction in each single cell. Here, the remaining oxidizing gas that has not participated in the electrochemical reaction once passes through the oxidizing gas distribution manifold 61 formed by the holes 41 provided in the separator 30.

In the oxidizing gas distribution manifold 61, the oxidizing gases passing through the respective gas passages in the single cell are gathered and can be circulated to each other. In the oxidizing gas distribution manifold 61, the collected oxidizing gas flows downward (see FIG. 5). This oxidizing gas is supplied to each single cell 20 through the hole 41 provided in each separator 30.
In this case, the gas is guided to the oxidizing gas flow path in the single cell formed between the concave portion 91 of each separator 30 and the adjacent cathode 33. The oxidizing gas guided to the oxidizing gas flow path in the single cell diffuses from the oxidizing gas flow path in the single cell to the catalyst layer on the electrolyte membrane 31 and is subjected to an electrochemical reaction in each single cell. Here, the remaining oxidizing gas that has not participated in the electrochemical reaction is discharged to the oxidizing gas discharge manifold 62 formed by the holes 42 provided in the separator 30.

In the oxidizing gas discharge manifold 62, the oxidizing gas passes through the oxidizing gas passages formed in each single cell 20 while passing the oxidizing gas in the opposite direction to the oxidizing gas supply manifold 60. Merge. When the oxidizing gas that has passed through the oxidizing gas discharge manifold 62 reaches the end of the stack structure 15, the oxidizing gas is provided in the hole 72 provided in the end plate 80, and in a position corresponding to the current collecting plate 36 and the insulating plate 38. The gas is discharged to the oxidizing gas discharge device connected to the hole 72 through the hole.

Although the flow of the oxidizing gas in the stack structure 15 has been described above, the flow of the fuel gas in the stack structure 15 is the same. The fuel gas supply device provided outside the fuel cell includes an end plate 8
The fuel gas supplied from the fuel gas supply device and connected to the hole 73 provided in the insulating plate 38 and the current collecting plate 3
6 is introduced into the fuel gas supply manifold 63 formed by the holes 50 provided in the separator 30 through the holes provided at the corresponding positions. The fuel gas passing through the fuel gas supply manifold 63 is guided to the fuel cell flow path (formed between the concave portion 92 and the adjacent anode 32) in each single cell 20 and supplied to the electrochemical reaction. Is done. Of the fuel gas passing through the fuel gas passage in the single cell in each single cell 20, the remaining gas not participating in the electrochemical reaction is supplied to the hole 51 provided in the separator 30.
Once pass through the fuel gas distribution manifold 64 formed. The fuel gas passing through these fuel gas distribution manifolds again passes through the fuel cell flow path (formed between the concave portion 93 and the adjacent anode 32) in the single cell in each single cell 20 to cause an electrochemical reaction. Offered to The remaining fuel gas not participating in the electrochemical reaction is supplied to the separator 3
The fuel gas is discharged to a fuel gas discharge manifold 65 formed by the holes 52 provided in the fuel gas supply manifold 6 and merged with each other.
It passes in the opposite direction to 3. When such fuel gas reaches the end of the stack structure 15, it passes through a hole 75 provided in the end plate 80 and a hole provided in a corresponding position of the current collector 36 and the insulating plate 38. Then, the fuel gas is discharged to the fuel gas discharge device connected to the hole 75.

In the above description, in the oxidizing gas supply manifold 60 and the oxidizing gas discharge manifold 62, and in the fuel gas supply manifold 63 and the fuel gas discharge manifold 65, the flowing direction of the gas passing through the inside is opposite. However, the gas may pass in the same direction between the supply-side manifold and the discharge-side manifold. That is, the end plate 80
The oxidizing gas discharging device and the fuel gas discharging device may be connected to the end plate 85 side instead of the side, and the gas may be discharged from the end of the stack structure 15 opposite to the end to which the gas is supplied. .

According to the fuel cell including the separator 30 of the present embodiment configured as described above, the fuel cell includes the oxidizing gas distribution manifold and the fuel gas distribution manifold. On the way to the gas distribution manifold, the gas once passes through the gas distribution manifold. Thereby, in a part of the unit cell constituting the fuel cell, the condensed water and the flow rate of the gas passing through the gas passage in the unit cell due to the accuracy of the concavo-convex shape formed on the separator surface are described. Even in the case where the variation occurs, by passing through the distribution manifold, the gas flow rate passing through the gas flow path in the single cell is made uniform, and the variation of the gas flow rate via the distribution manifold is reduced. For example, even in the case where the flow rate of the oxidizing gas passing through the oxidizing gas flow path in the single cell formed by the concave portion 90 due to the condensed water in any of the single cells 20 constituting the fuel cell, By passing through the oxidizing gas distribution manifold where the oxidizing gas passing through the single cell once gathers, the oxidizing gas is supplemented from the single cell arranged in the vicinity, and the oxidizing gas flow path in the single cell formed by the concave portion 91 is formed. The flow rate of the oxidizing gas is sufficient, and the amount of the oxidizing gas supplied in a specific single cell is not extremely reduced.
Conversely, even in the case where the flow rate of the oxidizing gas passing through the oxidizing gas flow path in the single cell formed by the concave portion 91 due to the condensed water in any of the single cells 20 constituting the fuel cell, By communicating with the oxidizing gas distribution manifold, a sufficient amount of the oxidizing gas can pass through the upstream single-cell oxidizing gas flow path formed by the concave portion 90. Therefore, it is possible to suppress the performance of the fuel cell from being deteriorated due to the variation in the gas flow rate passing through the gas flow path in each single cell.

FIG. 6 shows a comparison between the current-voltage characteristics of the fuel cell constituted by using the separator 30 of this embodiment and the fuel cell constituted by using the separator 130 shown in FIG. 8 as a comparative example. FIG. The separator 130 is
Although the separator has substantially the same shape as the separator 30 of the present embodiment, it does not have a structure corresponding to the hole 41 and the hole 51, and is formed continuously on one surface side of the separator 130, for example. Single recess 19 with three bends
0 is formed (see FIG. 8). Therefore, the fuel cell constituted by using the separator 130 does not have the oxidizing gas distribution manifold and the fuel gas distribution manifold, and the gas passing through each single-cell gas flow path is provided on the way as in the above embodiment. Once they can go to each other. In the separator 130 shown in FIG. 8, the same components as those of the separator 30 are denoted by the member numbers obtained by adding 100 to the member numbers assigned to the separator 30, and the detailed description is omitted. Also, the concave portion 190 of the separator 130
Also, a convex portion similar to the convex portion 94 provided in the concave portion 90 of the separator 30 shown in FIG. 4 is provided, and the separator 130 has the same gas diffusion electrode in the same area as that of the separator 30. To ensure conductivity.

As shown in FIG. 6, a fuel cell constituted by a separator 30 and having an oxidizing gas distribution manifold and a fuel gas distribution manifold is composed of a separator 13.
0, a higher output voltage could be maintained even when the output current was larger than that of a fuel cell having no oxidizing gas distribution manifold and no fuel gas distribution manifold. That is, by providing the distribution manifold and making the flow rate of the gas passing through the gas flow passage in each single cell uniform, it was possible to suppress the deterioration of the performance of the fuel cell.

Further, in the fuel cell constituted by using the separator 30, the flow rate of the gas passing through the gas passage in the single cell may decrease in some of the single cells constituting the fuel cell. In this case, not only the effect of equalizing the gas flow velocity in the gas flow path in the single cell, but also the effect of equalizing the gradient of the flow velocity of the gas passing through the gas flow path in the single cell in the entire fuel cell. To play. FIG. 7 shows the distribution state of the flow velocity of the gas passing through the internal single cell gas flow path in each of the fuel cell configured using the separator 30 and the fuel cell configured using the separator 130. FIG. 9 is an explanatory diagram showing a result. here,
Each fuel cell is made up of 100 single cells stacked, and the flow rate of gas passing through each single cell is measured as the gas flows from the gas supply manifold into the gas flow path inside each single cell. The values obtained were used.

In FIG. 7, the flow rate of the gas passing through the gas passage in the single cell provided at the upstream end (the side to which the gas supply device and the gas discharge device are connected) of the fuel cell is set to 10
It was set to 0, and the gas flow rates in the remaining gas flow paths in the single cell were sequentially expressed as relative values to this. When the gas supply device and the gas discharge device are connected to the same side end of the fuel cell as in the above-described embodiment, the upstream side which is the connected end has the fastest gas flow velocity. The gas flow rate gradually decreases toward the end on the opposite side (downstream side). Also in the fuel cell configured using the separator 30, the gas flow rate decreases from the upstream side to the downstream side (from the cell number 1 side to the cell number 100 side in FIG. 7), as shown in FIG. Next, a separator 130 as a comparative example
The degree to which the gas flow velocity decreases toward the downstream side is smaller than that of a fuel cell configured using

As described above, according to the fuel cell using the separator 30 of the present embodiment, the gradient of the flow velocity of the gas passing through each single-cell flow path becomes small, and the gas flow in the single cell is reduced in the entire fuel cell. Since the flow velocity of the gas passing through the road is maintained at a high level, the gas utilization rate is sufficiently high even in the single cell provided on the downstream side. Therefore, as shown in FIG. 6 described above, the reason why the fuel cell using the separator 30 exhibits high cell performance is due to the effect that a sufficient gas flow rate is maintained in the entire fuel cell. Can be considered.

Further, the flow rate of the gas passing through each single cell flow path in the entire fuel cell is increased, so that the flow rate of the gas can be maintained sufficiently large in the entire fuel cell, and the gas flow rate can be minimized. The degree to which the gas supplied to the fuel cell is pressurized in order to ensure a sufficient gas flow rate in the reduced area can be suppressed. In addition, by sufficiently increasing the gas utilization rate in the entire fuel cell, the effect that the flow rate of the gas supplied to the fuel cell can be reduced can be obtained. In general, a gas is supplied to a fuel cell in an amount exceeding a theoretically required gas amount based on the amount of electric power to be generated in order to sufficiently promote an electrochemical reaction.
As described above, when the gas utilization rate increases, the amount of gas supplied excessively can be suppressed in this manner. By suppressing the amount of gas supplied to the fuel cell and the degree of pressurization of the gas, the amount of fuel consumed for power generation can be reduced, and the amount of electric power consumed to pressurize the gas supplied to the fuel cell can be reduced. The energy efficiency of the entire system including the fuel cell can be improved.

In the fuel cell using the separator 30 in the above-described embodiment, when the gas passes through the gas passages in each single cell provided in each single cell, the gas is provided on the surface of the separator. Although the gas flows in a substantially horizontal direction according to the shape of the concave portion, the gas flows from the upper side to the lower side in the entire gas passage in each single cell. For example, the oxidizing gas flows from above where the holes 40 are provided to below where the holes 42 are provided. Therefore, the condensed water generated in the gas flow path is also guided downward together with the gas flow without opposing the gravity, so that the drainage of the condensed water from the gas flow path in the single cell is facilitated. Here, the condensed water generated in the flow path is, as described above, the generated water generated on the cathode side due to the electrochemical reaction or the electrolyte membrane prior to supplying the gas to the fuel cell. Water vapor or the like previously added to the supply gas in order to prevent drying of the gas is condensed in the gas flow path.

Further, in the fuel cell using the separator 30 of this embodiment, the gas manifold is provided on the side of the fuel cell, and the gas supplied to each unit cell is supplied to the gas passage in each unit cell. Flows sideways. Therefore, it is possible to suppress the condensed water generated in the gas manifold from blocking the vicinity of the connection portion with the gas manifold in the gas flow path in each single cell and obstructing the gas flow. On the other hand, when gas manifolds are provided above and below the fuel cell, and gas is supplied from an upper gas manifold to each single cell gas flow path, condensed water in the gas manifold is discharged. There is a possibility that the gas easily flows into the gas flow path in the single cell and the gas flow path is closed.

In the separator 30 of the above-described embodiment, the surface is divided into four parts in the horizontal direction, and the divided areas are continued two by two. For example, the concave part 90 and the concave part 91 are formed on the surface side shown in FIG. A single oxidizing gas distribution manifold 6 is formed by the holes 41 connecting the recesses 90 and 91 to each other.
1 was formed. Here, a plurality of oxidizing gas (or fuel gas) distribution manifolds may be provided, and an example of a separator having such a configuration is shown in FIG. Separator 23 shown in FIG.
No. 0 has one surface divided into four parts in the horizontal direction similarly to the separator 30, and this divided region has four separate concave parts (concave parts 290, 291, 29).
2, 293), and when a fuel cell is configured using the separator 230, these recesses form an oxidizing gas flow path in a single cell with an adjacent gas diffusion electrode. The separator 230 has five holes (holes 2).
40, 241, 242, 243, 244). When a fuel cell is configured using the separator 230, these holes form a gas manifold through which the oxidizing gas passes.

Here, the hole 240 forms an oxidizing gas supply manifold.
The oxidizing gas supplied from the outside is distributed to the gas flow paths in each single cell. The holes 242 form an oxidizing gas discharge manifold. The oxidizing gas discharge manifold joins the oxidizing gases discharged from the respective single-cell internal flow paths and guides them to the outside of the fuel cell. Holes 241, 24
3 and 344 respectively form oxidizing gas distribution manifolds, and the oxidizing gas passing through the oxidizing gas flow paths in each single cell formed in the single cell constituting the fuel cell is used as the oxidizing gas distribution manifold. Once through each.

The recess 290 is formed between the hole 240 and the hole 24.
And the recess 291 is formed between the hole 243 and the hole 24.
1, and the recess 292 is formed between the hole 241 and the hole 24.
4 and the recess 293 is formed between the hole 244 and the hole 24.
2 is communicated. Therefore, the oxidizing gas supplied from the outside is first introduced into the oxidizing gas flow path in the single cell formed by the concave portion 290 via the oxidizing gas supply manifold formed by the hole 240. The oxidizing gas having passed through the oxidizing gas flow path in the single cell passes through the oxidizing gas distribution manifold formed by the holes 243, and then passes through the oxidizing gas flow path in the single cell formed by the concave portion 291. After that, the same operation is repeated, and the hole 2
After passing through the oxidizing gas distribution manifold formed by the recess 292, passing through the oxidizing gas distribution manifold formed by the recess 292, passing through the oxidizing gas distribution manifold formed by the hole 244, and then forming by the recess 293. Through the oxidizing gas flow path in the single cell, and through the oxidizing gas discharge manifold formed by the hole 242,
It is discharged outside the fuel cell.

According to the fuel cell constituted by using such a separator 230, the flow rate of the oxidizing gas supplied to the gas passage in each single cell is made uniform, as in the above-described embodiment using the separator 30. At the same time, the gas flow velocity can be kept sufficiently high in the entire fuel cell to prevent the performance of the fuel cell from being reduced. In particular, the separator 30
Since the number of the oxidizing gas distribution manifolds is larger than that in the case of using, the effect of equalizing the flow rate of the oxidizing gas passing through each single cell can be further enhanced.

In the fuel cell using the separator 30 of the above-described embodiment, the gas distribution manifold is provided in both the flow path of the oxidizing gas and the flow path of the fuel gas. The gas distribution manifold may be provided only in the flow path, and a corresponding effect can be obtained even when such a gas distribution manifold is provided in one of the flow paths. In the separator 230 shown in FIG. 9, only one pair of manifolds through which the fuel gas passes is provided, and the gas distribution manifold is provided only on the oxidizing gas flow path side. Even in such a case, the flow rate of the oxidizing gas is made uniform. By doing so, the above effects can be sufficiently obtained. Of course, even if the distribution manifold is provided only on the side of the fuel gas flow path, the above-described effect of making the flow rate of the fuel gas uniform can be obtained. When the gas distribution manifold is provided only in one of the flow paths, it is not necessary to provide a hole for forming the gas distribution manifold in the other gas flow path, and the separator can be more easily formed.

In the above-described embodiment, the surface of the separator is divided into four parts in the horizontal direction. However, the surface of the separator may be divided into different numbers and a gas distribution manifold may be provided. Such an example is shown below. FIG. 10 is a plan view showing the configuration of a separator 330 in which the surface of the separator is divided into two parts in the horizontal direction. In the fuel cell configured using the separator 330, the oxidizing gas flow path in the single cell is formed by the concave portions 390 and 391 provided by dividing the surface of the separator 330 into two. In such a fuel cell, the oxidizing gas supply manifold is formed by the hole 340.
The holes 342 form an oxidizing gas discharge manifold, and the holes 343 form an oxidizing gas distribution manifold. The oxidizing gas distributed from the oxidizing gas supply manifold to each single cell passes through the oxidizing gas flow path in the single cell formed by the concave portion 390, passes through the oxidizing gas distribution manifold once, and then forms the single cell formed by the concave portion 391. The gas passes through the internal gas passage and is discharged to the outside via the oxidizing gas discharge manifold.

FIG. 11 is a plan view showing the structure of a separator 430 obtained by dividing the surface of the separator into three parts. In the fuel cell configured using the separator 430, the oxidizing gas flow path in the single cell is formed by the concave portions 490, 491, and 492 provided by dividing the surface of the separator 430 into three in the horizontal direction. In such a fuel cell, the oxidizing gas supply manifold is formed by the holes 440.
2 allows the oxidizing gas discharge manifold to be
444 forms an oxidizing gas distribution manifold. The oxidizing gas distributed from the oxidizing gas supply manifold to each single cell sequentially passes through the oxidizing gas flow path in the single cell formed by each of the concave portions 490, 491, and 492. At this time, the gas sequentially passes through an oxidizing gas distribution manifold that connects two continuous oxidizing gas channels in the single cell. Recess 4
The oxidizing gas that has passed through the gas flow path inside the single cell formed by 92 is discharged to the outside via the oxidizing gas discharge manifold.

FIG. 12 is a plan view showing the structure of a separator 530 obtained by dividing the surface of the separator into six parts. On one surface of the separator 530, three regions each of which the surface of the separator 530 is divided into six in the horizontal direction are provided in communication with each other, and concave portions 590 and 591 each having two bent portions are provided. I have. In the fuel cell configured using the separator 530, these recesses 590, 5
The oxidizing gas flow path in the single cell is formed by 91. In such a fuel cell, the oxidizing gas supply manifold is formed by the hole 540, the oxidizing gas discharge manifold is formed by the hole 542, and the oxidizing gas distribution manifold is formed by the hole 543. The oxidizing gas distributed from the oxidizing gas supply manifold to each single cell passes through the oxidizing gas flow path in the single cell formed by the concave portion 590, temporarily passes through the oxidizing gas distribution manifold, and then forms the single cell formed by the concave portion 591. The gas passes through the internal gas passage and is discharged to the outside via the oxidizing gas discharge manifold. The separator 530
In the above, only one hole is provided for forming the oxidizing gas distribution manifold, but more holes may be provided for providing a plurality of oxidizing gas distribution manifolds. For example, the recess 590 and the recess 591
A hole may be provided in the bent portion of the above, and the oxidizing gas distribution manifold may be further formed by such a hole.

As described above, the surface of the separator is divided into a plurality of regions, recesses for forming gas passages in the single cell are formed, and the gas distribution manifold is formed by the holes communicating with these recesses. Accordingly, the flow rate of the gas passing through the gas flow path in the fuel cell can be made uniform, and the above-described effect can be obtained. In the above description, FIG.
Although only the one surface side shown in FIG. 12, that is, the oxidizing gas flow channel has been described, the fuel gas flow channel provided on the other surface side has the same configuration, so that the gas flow channel is The flow rate of the passing gas can be made uniform, and the performance of the fuel cell can be improved. Here, the smaller the shape of the concave portion formed on the separator surface and the smaller the cross-sectional area of the gas flow path formed by such a concave portion, the more the gas flow rate passing through a predetermined position of the gas flow path in the single cell becomes. Increase
The gas diffusibility is improved, and the gas utilization rate is increased. Also, as the gas flow rate passing through the gas flow path in the single cell increases and the gas flow velocity increases, the condensed water is more likely to be blown away, and the condensed water hardly stays in the gas flow path in the single cell. The drainage in the flow path is improved. However, when the cross-sectional area of the flow path is reduced in this way, the pressure loss when the gas passes through the gas flow path in the single cell also increases. An increase in pressure loss when gas passes through increases the energy required to pressurize the gas supplied to the fuel cell, which may lead to a decrease in energy efficiency of the entire system including the fuel cell. Therefore, the fineness of the shape of the concave portion is appropriately determined in consideration of the effect of improving the gas utilization rate by reducing the size, the effect of increased pressure loss due to the fineness, and the processing accuracy required when forming the separator. You only have to decide.

As shown in FIG. 4 in the description of the separator 30, the gas passing through the flow path is diffused into the recess formed in the separator surface to form the gas flow path within the single cell. A plurality of convex portions for ensuring conductivity between the gas diffusion electrode and the gas diffusion electrode are provided. Here, the shape of the concave portion provided on the separator surface is sufficiently fine,
If the gas diffusibility and the conductivity between the gas diffusion electrode are sufficiently ensured, it is not necessary to provide such a convex structure corresponding to the convex portion 94 in the concave portion.

In the embodiment described above, all of the gas passing through the gas flow path in the single cell formed by the predetermined concave portion provided on the surface of the separator once passes through the gas distribution manifold, and then returns to each other. Although it was configured to flow into the single cell, part of the gas passing through the gas flow path in the single cell,
It is good also as composition not passing through a gas distribution manifold.
As an example of such a configuration, FIG. 13 shows a configuration of the separator 630 (a configuration on a surface side on which an oxidizing gas flow path is formed). The separator 630 has a concave portion 690 formed by dividing the surface thereof into four parts in the horizontal direction and sequentially communicating these with each other.
0, 641, 642. In the fuel cell configured using the separator 630, the oxidizing gas supplied to each unit cell from the oxidizing gas supply manifold formed by the hole 640 passed through the oxidizing gas flow path in the unit cell formed by the concave portion 690. Thereafter, the gas is discharged to the oxidizing gas discharge manifold formed by the holes 642 and guided to the outside of the fuel cell.

Here, the concave portion 690 forming the oxidizing gas flow path in the single cell is a region where the shape is bent on the separator 630, and the hole 6, which forms the oxidizing gas distribution manifold, is formed.
It is in communication with 41. Separator 30 of the already described embodiment
Although the recesses 90 and 91 communicate with each other through the hole 41, the structure of the recess is separated by the hole 41. The recess 690 provided in the separator 630 is not divided by the hole 641 as described above, but communicates by a recess structure formed continuously from the hole 640 to the hole 642. That is, the hole 64
1 is formed along one side of the separator 630 in communication with the concave portion 690 at an end portion (outside of the bend) where the concave portion 690 is bent, but a region (inside of the bend) adjacent to the hole 641 is The recess is formed continuously without being divided by the hole 690. Therefore, part of the oxidizing gas passing through the oxidizing gas flow path in the single cell once
The oxidizing gas flows through the oxidizing gas distribution manifold formed by the holes 641, but the remaining oxidizing gas passes through the oxidizing gas flow path in the single cell formed by the concave portion 690 without passing through the oxidizing gas distribution manifold. Discharged to the discharge manifold. In FIG. 13, the separator 630 is used.
Only one side (the side forming the oxidizing gas flow path in the single cell) is shown, but the other side (the side forming the fuel gas flow path in the single cell) is similarly formed. . That is,
The fuel gas supplied from the fuel gas supply manifold to each single cell is guided through the fuel gas flow path in the single cell formed by the concave portion similar to the concave portion 690, and a part of the fuel gas channel is formed by the same hole portion as the hole portion 641. The remaining fuel gas is guided to the fuel gas discharge manifold by the fuel gas flow path in the single cell formed by the recess without passing through the fuel gas distribution manifold.

According to the separator 630 having such a configuration, a part of the gas passing through the gas passage in the single cell is passed through the distribution manifold in the region where the concave portion (the gas passage in the single cell) is bent. By allowing the gas to pass through without bending, the gas pressure loss at such a bent portion can be suppressed, and the bias of the gas flow can be suppressed. As described above, the configuration in which the cross-sectional area of the gas flow path in the single cell formed on the separator is reduced is useful for increasing the flow rate and flow rate of the gas passing through the flow path. However, when a bent portion (a portion where the direction of gas flow changes) is provided in the single-cell gas flow channel as in the above-described embodiment in order to reduce the flow channel cross-sectional area, such a bent portion is required. In such a case, the pressure loss of the gas increases, and the flow of the gas is disturbed, causing a bias in the flow. In order to reduce the pressure loss at the bent portion, the flow path width may be increased at the bent portion. However, in the configuration in which the concave portion is divided by the hole as in the above-described embodiment, the flow path width at the bent portion is increased. Requires a larger hole. Such a configuration increases the area of the holes with respect to the entire separator, and reduces the ratio of the area available for the electrochemical reaction, which is difficult to employ. If the concave portion is continuous inside the bent portion as in the separator 630 described above, it is possible to sufficiently secure the flow path width in the bent portion without increasing the area of the hole,
It is possible to suppress an increase in pressure loss due to narrowing of the flow path at the bent portion.

FIG. 14 shows a separator 630 provided with a communication structure in which a gas can pass at a bent portion of a gas flow path in a single cell without passing through a gas distribution manifold.
Separator 3 in which a concave portion is divided by a hole at the bent portion
FIG. 7 is an explanatory diagram showing a result of simulating a gas flowing state in a fuel cell using each of the values 0 and 0. FIG. 14A shows a result using the separator 630,
FIG. 14B shows the results using the separator 30, and in each case, the pressure distribution in the gas distribution manifold is shown on the surface of a predetermined separator. As shown in FIG. 14 (B), when a separator having a concave portion divided by a hole is used, a very high pressure is generated in the gas distribution manifold formed by the hole, thereby causing The pressure loss when the gas passes through the flow path increases. On the other hand, as shown in FIG. 14A, in the case of using a separator having a recess having a communication structure through which a gas can pass without passing through the distribution manifold, the pressure generated in the gas distribution manifold is reduced. In addition, pressure loss when gas passes through the gas flow path in the single cell can be suppressed.

Although only the pressure distribution in the gas distribution manifold is shown in FIG. 14, by providing the communication structure adjacent to the gas distribution manifold, the gas flow path in the single cell connected to the gas distribution manifold is reduced. ,
In addition to suppressing the pressure loss, there is obtained an effect that the gas flow is less likely to be biased. As shown in FIG. 14 (B), when a particularly high pressure is generated at a predetermined portion in the gas distribution manifold and the pressure loss of the gas when passing through the distribution manifold is large, the gas downstream of the gas distribution manifold is The flow of the gas is biased, for example, a region where the flow velocity of the gas significantly decreases. If the gas flow in the gas flow path in the single cell becomes non-uniform as described above, the efficiency with which the electrochemical reaction proceeds varies from place to place. When the communication structure is provided adjacent to the gas distribution manifold as in the case of using the separator 630, the occurrence of bias in the gas flow is suppressed, and the efficiency of the electrochemical reaction is sufficiently secured on the entire surface of the separator. can do.

Further, the structure in which the communication structure is provided adjacent to the gas distribution manifold like the separator 630 is as follows.
This is also effective in reducing the size of the fuel cell. That is, as a configuration for reducing the size of the fuel cell without lowering the cell performance, a configuration in which the hole for forming the gas manifold is made smaller is conceivable.However, if the communication structure is provided adjacent to the gas distribution manifold, Thus, even if the hole is made small in this way, it is possible to suppress the occurrence of the inconvenience that the pressure loss when the gas passes through becomes too large or the flow of the gas deteriorates. In such a case,
While the fuel cell is downsized, part of the gas passing through the gas flow path inside the single cell passes through the gas distribution manifold, so that the effect of equalizing the gas flow rate can be obtained, and the remaining gas can be used as the gas distribution manifold. By not passing through, a sufficient gas flow can be secured.

In the separator of the above-described embodiment, the gas flow path in the single cell formed by the concave portion provided on the separator has a gas flow at the bent portion where the flow direction of the gas passing through the flow path is changed. Communicates with distribution manifold. Here, a hole provided in the separator and forming a gas distribution manifold in the fuel cell is formed along a predetermined side in a peripheral portion of the separator. In such a separator, it is also desirable that the distance between the outer edge of the separator and the hole is increased at the end of the hole. Such a configuration will be described with reference to FIG.

FIG. 15A shows a configuration in which the distance between the outer edge of the separator and the hole is increased at the end of the hole, and FIG. 15B shows the structure between the outer edge of the separator and the hole. This shows a configuration in which the distance is constant. FIG.
5 shows only the vicinity of one end of the hole forming the gas distribution manifold in the structure of the separator, but the separator shown in FIG. 15B is the same as the separator 30 of the above-described embodiment. The separator 30A shown in FIG. 15A also has the same configuration as the separator 30 at other parts (not shown), and common members are denoted by the same reference numerals as those of the separator 30. Omitted. Separator 30A has holes 41A forming an oxidizing gas distribution manifold in the same manner as holes 41 in separator 30.
It has. At the end of the hole 41A, only the side near the outer edge of the separator 30A is gently inclined toward the inside of the separator 30A, so that the end of the hole 41A becomes gradually thinner. Is formed.

According to the separator 30A thus configured, a fuel cell having more excellent durability can be formed. When the gas distribution manifold is formed by the holes provided in the separator as described above, the gas passing through the gas flow path in the single cell is bent at the bent portion of the gas flow path in the single cell provided with the gas distribution manifold. (See solid arrows in FIG. 15 (B).), In each of the separators constituting the fuel cell, a force acts on the holes forming the gas distribution manifold toward the outside of the separators. 15 (B). Such outward stress is particularly concentrated on each separator at the periphery of the separator near the end of the hole forming the gas distribution manifold. The position where the force acts in such a concentrated manner is shown in the separator 30 of FIG. The hole 41 is provided as close as possible to the outer edge of the separator 30 to suppress an increase in the size of the fuel cell. However, when the distance between the hole 41 and the outer edge of the separator is reduced as shown in FIG. As shown in (2), stress concentrates on the thin member, which is a problem in securing sufficient strength and durability of the fuel cell. FIG. 15 (A)
When the hole 41A is formed so that the distance from the outer edge of the separator to the end thereof is increased as in the separator 30A shown in FIG. Durability can be sufficiently ensured. Further, as described above, according to the configuration in which the shape of the hole 41A is such that the distance from the outer edge of the separator to the end thereof is increased, the entire hole 41A can be formed without being formed farther from the outer edge of the separator. In order to achieve the strength described above, the entire separator, and thus the entire fuel cell, is not increased in size in order to secure the strength of the separator.

Further, when forming the shape of the hole 41A such that the distance from the outer edge of the separator to the end thereof is increased, as shown in FIG. Only the side near the outer edge of the separator 30A is
If the shape is such that the shape gradually slopes toward the inside of the separator 30A toward the end of the hole 41, the gas passing through the gas flow path within the single cell can be guided to this shape and smoothly flow. Can be. If a corner is formed at the end of the hole 41 as shown in FIG. 15 (B), the gas passing through the bent portion of the gas flow path in the single cell generates a turbulent flow at this corner. As a result, the gas pressure loss is further increased. By forming the flow path along the gas flow direction as shown in FIG. 15A, such a pressure loss can be suppressed and the gas flow can be made smooth. In FIG. 15, the flow path side of the oxidizing gas is shown, but the same effect can be obtained also by forming the gas distribution manifold with holes having the same shape on the flow path side of the fuel gas. Also, in FIG. 15, only one of the ends of the hole forming the gas distribution manifold is shown, but by forming both ends in the above-described shape,
The above-described effect of securing the strength of the separator and smoothing the gas flow can be further increased.

In the above-described embodiment, the hole forming the gas distribution manifold is provided at the bent portion of the concave portion forming the gas flow path in the single cell, that is, near the outer periphery of the separator. Even if the gas distribution manifold is formed by holes provided in different regions of the separator, the effect of making the flow velocity of the gas passing through the gas flow path uniform can be obtained. An example of such a configuration is shown in FIG.
FIGS. 16 and 17 show the separator and the separator 830, respectively.

FIG. 16 is a plan view showing the structure of separator 730 (the structure on the side forming the oxidizing gas flow path). The surface of the separator 730 is divided into four parts in the horizontal direction.
91, 792, 793 are provided. Separator 7
In the fuel cell constituted by using the fuel cell 30, the separator 730 is used.
Recesses 790, 791, 792, 79 provided on the surface of
3 are connected in this order to form an oxidizing gas flow path in the single cell, and the oxidizing gas supply manifold is
The holes 742 form an oxidizing gas discharge manifold, and the holes 743, 744, and 745 form an oxidizing gas distribution manifold.

Here, the hole 743 connects the recesses 790 and 791, and the hole 744 connects the recesses 791 and 791.
92, and the hole 745 is formed with the concave portions 792 and 79
3, the holes are provided closer to the center of the separator, unlike the holes forming the gas distribution manifold in the above-described embodiment.
That is, instead of being provided at a bent portion that protrudes from the concave portion provided on the separator surface toward the outer peripheral portion of the separator, it is provided so that end side surfaces of adjacent concave portions communicate with each other (see FIG. 16). .

FIG. 17 is a plan view showing a configuration of separator 830 (a configuration on a surface side on which an oxidizing gas flow path is formed). The surface of the separator 830 is divided into three parts in the horizontal direction. The first part and the vicinity of the middle of the second step form a concave portion 890 continuously, and the part from the vicinity of the middle of the second step to the third step is formed. The recess 891 is formed continuously. A connecting portion between the concave portions 890 and 891, that is, the separator 8
In the vicinity of the central portion of the hole 30, a hole 843 for communicating these concave portions is provided (see FIG. 17). Separator 8
In the fuel cell configured using the fuel cell 30, the separator 830
The recesses 890 and 891 provided on the surface of the hole are connected in this order to form an oxidizing gas flow path in the single cell, the oxidizing gas supply manifold is formed by the hole 840, and the oxidizing gas discharge manifold is formed by the hole 842. 843 forms an oxidizing gas distribution manifold.

In the separators 730 and 830 shown in FIGS. 16 and 17, such a gas distribution manifold is provided only on the oxidizing gas flow path side, but the same gas distribution manifold is provided on the fuel gas flow path side. A manifold may be provided.

As described above, the hole forming the gas distribution manifold may be provided in any region on the separator, and the gas distribution manifold formed by the hole is formed by the concave portion provided on the surface of the separator. If the gas passing through each single cell can once pass through this gas distribution manifold, it passes through the gas flow path inside the fuel cell. The effect of making the gas flow rate uniform can be obtained. Therefore, in addition to the number of divisions on the separator for providing the concave portion and the number of distribution manifolds, the position of the hole for forming the distribution manifold, and the like, are determined by the energy efficiency of the entire system including the fuel cell and the installation of the fuel cell. The design can be freely performed while appropriately considering restrictions on the space to be provided.

The embodiments of the present invention have been described above.
The present invention is not limited to such embodiments at all, and it goes without saying that the present invention can be implemented in various modes without departing from the gist of the present invention.

[Brief description of the drawings]

FIG. 1 is an exploded perspective view showing a configuration of a single cell 20 which is a basic unit of a stack structure 15 constituting a fuel cell according to a first embodiment.

FIG. 2 is a plan view illustrating a configuration of a separator 30.

FIG. 3 is a perspective view illustrating an appearance of a stack structure 15;

FIG. 4 is an explanatory diagram showing a state of a convex portion 94 provided in a concave portion 90.

FIG. 5 is an explanatory diagram three-dimensionally showing a flow of an oxidizing gas in a stack structure 15;

FIG. 6 is an explanatory diagram showing current-voltage characteristics in a fuel cell configured using each of a separator 30 and a separator 130.

FIG. 7 is an explanatory diagram showing a flow velocity relative value in each unit cell constituting a fuel cell in a fuel cell configured using each of a separator 30 and a separator 130.

FIG. 8 is a plan view illustrating a configuration of a separator 130 used as a comparative example.

FIG. 9 is a plan view illustrating a configuration of a separator 230.

FIG. 10 is a plan view illustrating a configuration of a separator 330.

FIG. 11 is a plan view illustrating a configuration of a separator 430.

FIG. 12 is a plan view illustrating a configuration of a separator 530.

FIG. 13 is a plan view illustrating a configuration of a separator 630.

FIG. 14 is an explanatory diagram showing a result of simulating a gas flow state in the gas distribution manifold.

FIG. 15 is an explanatory diagram illustrating a configuration of one end of a hole forming a gas distribution manifold.

FIG. 16 is a plan view illustrating a configuration of a separator 730.

FIG. 17 is a plan view illustrating a configuration of a separator 830.

FIG. 18 is a plan view illustrating a configuration of a separator 930 which is an example of a conventionally known separator.

[Explanation of symbols]

 Reference Signs List 15 Stack structure 20 Single cell 30 Separator 31 Electrolyte membrane 32 Anode 33 Cathode 36, 37 Current collector 36A, 37A Output terminal 38, 39 Insulating plate 40-42 Hole 50-52 Hole 60: Oxidizing gas supply manifold 61: Oxidizing gas distribution manifold 62: Oxidizing gas discharge manifold 63: Fuel gas supply manifold 64: Fuel gas distribution manifold 65: Fuel gas discharge manifold 70, 72, 73, 75: Hole 80, 85 ... end plate 90, 91, 92, 93 ... concave part 94 ... convex part 130 ... separator 190 ... concave part 230 ... separator 240, 241, 242, 243, 244 ... hole part 290, 291, 292, 293 ... concave part 330 ... separator 340, 342, 343 ... hole 390, 391 ... recess 30 separator 440, 442, 443, 444 hole 490, 491, 492 recess 530 separator 540, 542, 543 hole 590, 591 recess 630 separator 640 to 642 hole 690 recess 730 Separator 740, 742, 743 to 745 ... hole 790 to 793 ... recess 830 ... separator 840, 842, 843 ... hole 890, 891 ... recess 930 ... separator 940, 942, 950, 952 ... hole 990 ... recess

Claims (12)

[Claims] 1. A fuel cell comprising a plurality of unit cells stacked to obtain an electromotive force by an electrochemical reaction using gas in each unit cell, wherein the fuel cell is provided in each of the unit cells continuously, A gas flow path in a single cell for passing a gas and distributing the gas into each of the single cells; and distributing the gas flowing from outside the fuel cell to each of the gas flows in the single cell. A gas supply manifold to be supplied to a passage, a gas discharge manifold to collect the gas discharged from each of the single-cell gas flow paths, and to discharge the gas to the outside of the fuel cell. A fuel cell, comprising: a distribution manifold that penetrates each of the gas passages in the single cell and enables the gas to flow between the gas passages in the single cell. 2. The fuel cell according to claim 1, comprising a plurality of said distribution manifolds. 3. The fuel cell according to claim 1, wherein the gas is a fuel gas containing hydrogen. 4. The fuel cell according to claim 1, wherein the gas is an oxidizing gas containing oxygen. 5. The fuel cell according to claim 1, wherein the gas flow path in the single cell has a bent portion where the flow path is bent so as to change a direction of a flow of the gas passing through the inside. The bent portion includes: a first region through which the distribution manifold penetrates; and a part of the gas that passes through the inside of the bent portion.
A second region allowing passage without passing through the distribution manifold. 6. The fuel cell according to claim 5, wherein the bent portion has a U-shape. 7. The fuel cell according to claim 1, wherein the gas flow path in the single cell has a bent portion in which the flow path is bent so as to change a direction of a flow of the gas passing through the inside. The fuel cell is configured such that the outer periphery of the bent portion is smoothly curved, and the distribution manifold penetrates the gas flow path inside the single cell at the outer peripheral portion of the bent portion. 8. The fuel cell according to claim 1, wherein the gas flow path in the single cell has a bent portion in which the flow path is bent so as to change the direction of the flow of the gas passing through the inside. Near the outer edge of the fuel cell, the distribution manifold is provided near the outer edge of the fuel cell, and at the outer periphery of the bent portion,
The cross-sectional shape of the distribution manifold is formed in a vertically long shape along the outer edge of the fuel cell, and the vertical shape of the inner wall surface on the fuel cell outer edge side in the distribution manifold is formed. A fuel cell, wherein an inner wall surface corresponding to an end portion of the cross-sectional shape is thicker than an inner wall surface corresponding to a center portion of the cross-sectional shape from an outer edge of the fuel cell. 9. A gas separator for a fuel cell, which is used in a fuel cell having a plurality of unit cells stacked and constitutes the unit cell together with a member forming an electrolyte layer and an electrode, wherein the gas separator for a fuel cell is provided. Are provided in the thickness direction thereof, respectively, and three or more holes for respectively forming a part of the gas manifold of the fuel cell, and on one surface of the fuel cell gas separator,
Of the three or more holes, a predetermined first hole to a predetermined second hole are provided so as to communicate on the surface while sequentially passing through holes other than the first and second holes. And a recess for forming a gas flow path in the single cell. 10. The gas separator for a fuel cell according to claim 9, wherein the concave portion extends from the predetermined first hole to the second hole.
The fuel cell gas separator further includes a bent portion that is bent on the one surface in the middle of the communication on one surface of the gas separator, wherein the bent portion has one of the holes other than the first and second holes penetrating therethrough. First
Without being divided into the region and the hole penetrating the first region,
A second region in which the bottom surface of the concave portion is formed continuously. 11. The gas separator for a fuel cell according to claim 9, wherein the concave portion extends from the first hole to the second hole.
In the middle of communicating on one surface of the fuel cell gas separator, the fuel cell gas separator has a bent portion bent on the one surface near an outer edge of the fuel cell gas separator, and the first and second holes. One of the other holes is disposed near the outer edge of the fuel cell gas separator, forms a vertically long shape along the outer edge of the fuel cell gas separator, and the outer peripheral portion of the bent portion has the concave portion. Of the wall surface forming the hole, the wall surface located on the outer edge side of the gas separator for a fuel cell has a portion corresponding to an end portion of the vertically elongated hole, and a portion corresponding to a central portion. A gas separator for a fuel cell, wherein the distance from the outer edge of the gas separator for a fuel cell is increased. 12. A gas distribution method in a fuel cell comprising a plurality of unit cells stacked one upon another, receiving a supply of gas, and obtaining an electromotive force by an electrochemical reaction using the gas, wherein: (B) distributing the gas supplied from the outside of the cell to a gas flow path in a single cell formed inside each single cell via a gas supply manifold provided in the fuel cell; Providing the gas distributed from the gas supply manifold to an electrochemical reaction progressing in each of the single cells while passing the gas distributed from the gas supply manifold through the gas flow path in the single cell; (c) The gas discharged from each of the single-cell gas channels after being subjected to the electrochemical reaction is collected in a gas discharge manifold provided in the fuel cell, and the collected gas is discharged outside the fuel cell. (B-1) in the (b) step, in each of the single cells, at least a part of the gas passing through the gas flow path in the single cell, the inside of the fuel cell, A gas distribution method for a fuel cell, further comprising a step of passing through a distribution manifold provided so as to penetrate in a stacking direction of single cells.