JP2001250568A - Current collector plate for polymer electrolyte fuel cells - Google Patents

Abstract

(57) [Problem] To provide a current collector plate of a polymer electrolyte fuel cell that can suppress the occurrence of blockage due to liquefied moisture on the downstream side of a gas passage and maintain good power generation efficiency. . A current collector is disposed between a pair of electrolyte membranes of a polymer electrolyte fuel cell. In the current collector 10,
A plurality of fuel gas passages 50 are formed on the surface of one of the electrolyte membranes facing the cathode. In addition, the current collector 10
In the above, a plurality of oxidant gas passages for flowing an oxidant gas in a direction opposite to a gas flow direction in the fuel gas passage 50 are formed on a surface of the other electrolyte membrane facing the anode. In each gas passage, a plurality of communication passages communicating adjacent passages are formed, and the formation density of the communication passages is set to be higher toward the downstream side in the gas flow direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a current collector plate of a polymer electrolyte fuel cell in which at least one of a fuel gas passage and an oxidizing gas passage is formed on a surface on which an electrolyte membrane is laminated.

[0002]

2. Description of the Related Art In a polymer electrolyte fuel cell, one cell (unit cell) is composed of an electrolyte membrane made of a solid polymer material and reaction electrodes (anode and cathode) provided so as to sandwich the electrolyte membrane from both sides. ) Is configured. Then, while bringing the fuel gas containing hydrogen into contact with the cathode,
An oxidizing gas containing oxygen is brought into contact with the anode, and the electrical energy generated when water is produced by a reduction reaction between hydrogen ions moving from the cathode to the anode through the electrolyte membrane and the oxygen at the anode is converted into each of them. It is taken out from the reaction electrode.

[0003] Generally, in a polymer electrolyte fuel cell,
Since there is a limit to the electromotive force that can be taken out by only one unit cell, a desired electromotive force is obtained by alternately stacking a plurality of unit cells and members called current collectors. This current collector plate is formed of, for example, a conductive material such as carbon, and has a function of electrically connecting each reaction electrode, and also supplies a fuel gas or an oxidizing gas between the reaction electrode and the surface thereof. It also has a function of forming a gas passage.

By the way, in a polymer electrolyte fuel cell,
When the amount of water in the electrolyte membrane decreases, the ionic conductivity decreases and the power generation efficiency decreases.On the other hand, when the amount of water in the electrolyte membrane excessively increases, gas diffusion at each reaction electrode is hindered. Will be invited. For this reason, in such a polymer electrolyte fuel cell, it is necessary to appropriately manage the water content of the electrolyte membrane in order to maintain a predetermined power generation efficiency. For example, water generated by the reduction reaction moves downstream together with the gas in the gas passage,
If the amount of water decreases at one end of the electrolyte membrane located on the upstream side of the gas passage and the amount of water excessively increases at the other end of the electrolyte membrane located on the downstream side, the power generation efficiency may decrease. Will be invited.

Therefore, conventionally, for example, Japanese Patent Application Laid-Open No. 10-3201
As disclosed in Japanese Patent Application Laid-Open No. 1 (1999) -107, it is known that a gas passage formed in each surface of a current collector plate is formed by a plurality of parallel grooves, and gas flows in adjacent grooves are set to face each other. I have. According to such a configuration, the average moisture distribution in each gas passage of the current collector plate is substantially uniform in the gas flow direction, so that the amount of moisture in the electrolyte membrane is appropriately maintained.

However, in such a configuration, it is necessary to make the gas flows of the adjacent parallel grooves formed on the same surface be opposed to each other, so that the gas passage in the current collector plate is inevitably complicated. Therefore, it is conceivable that the fuel gas in the fuel gas passage formed on one surface of the current collector plate and the oxidant gas in the oxidant gas passage formed on the opposite surface flow in opposite directions. .

In such a configuration, the downstream portion of the fuel gas passage where the moisture content of the gas increases and the upstream portion of the oxidant gas passage where the moisture content decreases become located on both sides of the electrolyte membrane. In addition, the upstream portion of the fuel gas passage where the water content decreases and the downstream portion of the oxidizing gas passage where the water content increases increase are located on both sides of the electrolyte membrane. Accordingly, the sum of the amounts of water supplied from the gas in each gas passage to the electrolyte membrane can be maintained substantially constant in the gas flow direction without complicating the configuration of each gas passage, and the electrolyte membrane of the same membrane can be maintained. The amount of water can be adjusted appropriately.

[0008]

However, when the flow of the fuel gas and the flow of the oxidizing gas are made to face each other as described above, the following inconvenience occurs in the gas flow in each gas passage. Become.

That is, the water generated on the anode side by the reduction reaction moves to the downstream side of the oxidizing gas passage together with the oxidizing gas, while the water reversely diffused from the anode side to the cathode side through the electrolyte membrane together with the fuel gas. It moves to the downstream side of the fuel gas passage. Then, due to the movement of the moisture, the concentration of the moisture contained in the gas may excessively increase in the downstream portion of each gas passage, and the moisture may liquefy and close each gas passage. As a result, the flow of gas in each gas passage is hindered, and the power generation efficiency is reduced.

The present invention has been made in view of such a conventional situation, and has as its object to suppress the occurrence of blockage due to liquefied water in a downstream portion of a gas passage and maintain good power generation efficiency. It is an object of the present invention to provide a current collector plate of a polymer electrolyte fuel cell which can be used.

[0011]

The means for achieving the above object and the effects thereof will be described below. According to the first aspect of the present invention, the fuel gas passage and the oxidant gas passage for flowing the fuel gas and the oxidant gas in opposite directions are used in a polymer electrolyte fuel cell provided on both sides of an electrolyte membrane. In a current collector plate of a polymer electrolyte fuel cell in which at least one of the gas passages is formed on a layered surface with the electrolyte membrane, the gas passages are formed by a plurality of flow passages, and the adjacent flow passages Are formed, and the degree of communication by the communication portions is set to be greater toward the downstream side in the gas flow direction.

According to the structure of the first aspect, the moisture contained in the gas in the gas passage increases in the downstream portion of the gas passage, but the downstream portion communicates with the adjacent flow passage. Since the degree of communication between the parts is set relatively large, diffusion of the gas is promoted in the communication part, and liquefaction of water contained in the gas is suppressed.

On the other hand, in the upstream portion of the gas passage,
Since the communication degree of the communication portion is set relatively small, excessive gas diffusion is suppressed. Therefore, a decrease in the gas flow rate is suppressed, and the composition of the gas in contact with the electrolyte membrane can be made uniform.

As a result, according to the above configuration, it is possible to suppress the occurrence of blockage due to liquefied moisture in the downstream portion of the gas passage, and it is possible to maintain good power generation efficiency.

In order to set the degree of communication of the communication portion to be higher toward the downstream side in the gas flow direction as in the above configuration, for example, the formation density of the communication portion is set to be higher toward the downstream side.
Alternatively, a configuration in which the communication area of the communication portion is set to be larger toward the downstream side can be adopted.

According to a first aspect of the present invention, as described in the second aspect, the gas passage has an upstream portion formed by a parallel groove and a downstream portion formed by a lattice groove. Such a configuration can also be embodied.

According to a third aspect of the present invention, in the current collector plate of the polymer electrolyte fuel cell according to the second aspect, the parallel groove is formed in a straight line without a bent portion.

According to the above configuration, in the upstream portion of the gas passage, for example, the surface area of the electrolyte membrane in contact with the gas becomes smaller as compared with the case where the gas passage is constituted by lattice grooves, and The total amount of water carried away from the electrolyte membrane by the gas flowing through the passage is reduced. Further, the flow resistance when the gas passes through the upstream portion of the gas passage is reduced. Therefore, it is possible to maintain a good power generation efficiency by suppressing an excessive decrease in the amount of water in a portion of the electrolyte membrane that is located on the upstream side of the gas passage, and to reduce a pressure at which the gas passes through the gas passage. Loss can be reduced.

According to a fourth aspect of the present invention, in the current collector of the polymer electrolyte fuel cell according to any one of the first to third aspects, the gas passage has a length L1 in a gas flow direction.
Is set to be longer than the length L2 in the direction orthogonal to the gas flow direction.

According to the above configuration, by setting the length L1 in the gas flow direction of the gas passage to be longer than the length L2 in the direction perpendicular to the gas flow direction, the flow velocity of the gas in the gas passage can be increased. As a result, the composition of the gas in contact with the electrolyte membrane can be made uniform, and good power generation efficiency can be secured.

According to a fifth aspect of the present invention, in the current collector plate of the polymer electrolyte fuel cell according to the fourth aspect, the length L1 in the gas flow direction and a direction orthogonal to the gas flow direction. Is L1 / L2>
By adopting a configuration in which the relationship is set to have two relationships, the operation and effect of the invention described in claim 4 can be made more remarkable.

[0022]

DESCRIPTION OF THE PREFERRED EMBODIMENTS One embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a perspective structure of a polymer electrolyte fuel cell 30 using a current collector 10 according to the present embodiment.

As shown in FIG. 1, the fuel cell 30 includes a substrate 20 and a current collector 10 which are alternately stacked, and
And a pair of side plates 40 sandwiching a laminated body composed of the current collector 10 and the current collector 10 from both sides.

FIG. 2 is a sectional view of the laminate taken along the line 2-2 in FIG. 1, that is, the gas passages 50 and 6 described later.
Substrate 20 and current collector 10
2 shows a cross-sectional structure along a plane extending in the laminating direction of FIG.

As shown in FIG. 2, the substrate 20 includes an electrolyte membrane 22 and reaction electrodes (a cathode 23 and an anode 24) sandwiching the electrolyte membrane 22 from both sides. The electrolyte membrane 22 is formed of a polymer material such as a fluorine-based resin, which exhibits ionic conductivity in an appropriate wet state. The reaction electrodes 23 and 24 are formed of carbon fibers containing a catalyst such as platinum.

On the other hand, the current collector plate 10 is formed in a rectangular plate shape from a conductive material such as carbon. This current collector 10
Has a function of electrically connecting the reaction electrodes 23 and 24 and a function of forming gas passages 50 and 60 for supplying a fuel gas and an oxidizing gas between the reaction electrodes 23 and 24 and the surface thereof. It has both.

FIG. 3 shows one of the reaction electrodes 23 and 24 of the current collector plate 10 facing the cathode 23. As shown in the figure, a fuel gas passage 50 for flowing a fuel gas such as hydrogen gas is formed in the lamination surface. FIG. 5 shows the other laminated surface of the reaction electrodes 23 and 24 facing the anode 24 in the current collector plate 10. As shown in the figure, an oxidizing gas passage 60 for flowing an oxidizing gas such as air is formed on the lamination surface of the current collector plate 10 facing the anode 24.

As shown in each of these figures, the current collector 1
A first air supply hole 501 and a second air supply hole 503 for supplying the fuel gas to the fuel gas passage 50 are formed at one end (the right end in FIG. 3 and the left end in FIG. 5). A first exhaust hole 602 and a second exhaust hole 604 for discharging the oxidizing gas from the oxidizing gas passage 60 are formed at positions adjacent to the air supply holes 501 and 503, respectively.

On the other hand, a fuel gas passage 50 is provided at the other end (the left end in FIG. 3 and the right end in FIG. 5) of the current collector plate 10.
A first exhaust hole 502 and a second exhaust hole 504 for discharging fuel gas from the fuel cell are formed, and an oxidant gas passage 60 is provided at a position adjacent to each of the exhaust holes 502 and 504. A first gas supply hole 601 and a second gas supply hole 603 for supplying gas are formed.

As described above, each of the air supply holes 501 and 503 of the fuel gas passage 50 and each of the air supply holes 60
1, 603, and each exhaust hole 50 of the fuel gas passage 50
2, 504 and the respective exhaust holes 602, 6 of the oxidizing gas passage 60.
2 are formed at the opposite ends of the current collector plate 10, respectively, so that the fuel gas and the oxidizing gas are substantially mutually separated in the gas passages 50 and 60 as shown by arrows in FIG. They flow in opposite directions.

And, as described above, each of the gas passages 50, 60
Is set in the opposite direction, the sum of the amounts of water supplied from the fuel gas and the oxidizing gas to the electrolyte membrane 22 becomes substantially constant in the gas flow directions of the gas passages 50 and 60, respectively. The water content of the film 22 is maintained at an appropriate amount.

In the current collecting plate 10, the inside of the current collecting plate 10 is provided between a first exhaust hole 602 for the oxidizing gas passage 60 and a second air supply hole 503 for the fuel gas passage 50. Is formed with a water supply hole 701 for supplying cooling water to a cooling water passage (not shown) formed at the bottom. Further, a drain hole 702 for discharging cooling water from the cooling water passage is provided between the second air supply hole 603 for the oxidizing gas passage 60 and the first exhaust hole 502 for the fuel gas passage 50. Is formed.

On the other hand, when the substrate 20 is laminated with the current collector 10, the holes 501 to 504,
Holes (not shown) are formed at positions corresponding to 601 to 604, 701, and 702, respectively. In a state where the current collector plate 10 and the substrate 20 are stacked, holes 501 to 504, 60 formed at respective positions of the current collector plate 10 are provided.
1 to 604, 701, and 702 communicate with each other through holes formed in the substrate 20.

As shown in FIG. 3, the stacking surface of the current collector plate 10 facing the cathode 23 is recessed so as to connect the first gas supply hole 501 and the first gas discharge hole 502 for the fuel gas passage 50. 505 are formed. Similarly, a second air supply hole 503 and a second exhaust hole 50 for the fuel gas passage 50 are provided on the stacking surface of the current collector plate 10 facing the cathode 23.
4, another recess 506 is formed alongside the recess 505.

In each of these concave portions 505 and 506,
A first section having a rectangular cross section extending along the gas flow direction is provided at a position near each of the air supply holes 501 and 503, that is, on the upstream side in the substantial gas flow direction (left-right direction in FIG. 3) of the fuel gas passage 50. Are formed at predetermined intervals.

On the other hand, in each of the concave portions 505 and 506,
A second convex portion 508 having a square cross section is located on the same straight line as the first convex portion 507 at a position near each of the exhaust holes 502 and 504, that is, on the downstream side in the gas flow direction. A plurality are formed at regular intervals in the gas flow direction and in a direction perpendicular to the gas flow direction.

The first projection 507 and the second projection 5
08 denotes a cathode 23 of the substrate 20 in a state where the current collector plate 10 and the substrate 20 are stacked as shown in FIG.
Is in contact with

Each of the recesses 505 and 506 has a first
The flow grooves 800 for flowing the fuel gas are formed by the convex portions 507 and the second convex portions 508 of
00 defines a fuel gas passage 50. The fuel gas passage 50 has a length L1 in the gas flow direction.
(See FIG. 3) is set to be longer than the length L2 (see FIG. 3) in the direction orthogonal to the gas flow direction. More specifically, the lengths L1 and L2 are set so that the relationship of L1 / L2> 2 holds.

As shown in FIG. 4, the flow grooves 800 are
A parallel groove 801 formed between each first convex portion 507;
It is constituted by lattice grooves 802 formed between the second convex portions 508. The parallel groove 801 has a straight shape without a bent portion, and is located on the upstream side in the gas flow direction. On the other hand, the lattice groove 802 is
It is located downstream in the gas flow direction.

In each of the concave portions 505 and 506, a portion extending in the gas flow direction in the lattice groove 802 and the parallel groove 8 are formed.
01, a plurality of linear flow paths (hereinafter, referred to as “main flow paths”) 51 are formed. The adjacent main flow paths 51 are connected to each other by flow paths (hereinafter, referred to as “communication paths”) 52 formed by portions of the lattice grooves 802 extending in a direction orthogonal to the gas flow direction. Since the lattice grooves 802 are formed only on the downstream side in the gas flow direction in each of the concave portions 505 and 506, the formation density of the communication path 52 is set to be higher on the downstream side than on the upstream side. That is, the degree of communication of the main flow path 51 by the communication path 52 is set to be relatively large toward the downstream side.

As shown in FIG. 5, a first supply hole 601 and a first exhaust hole 602 corresponding to the oxidizing gas passage 60 are connected to the stacking surface of the current collector plate 10 facing the anode 24. Thus, a recess 605 is formed. Similarly, on the laminated surface of the current collector plate 10 facing the anode 24,
Another concave portion 606 is formed alongside the concave portion 606 so as to connect the second air supply hole 603 and the second exhaust hole 604 corresponding to the oxidizing gas passage 60.

In each of these recesses 605 and 606,
At positions near the air supply holes 601 and 603, that is, upstream of the oxidizing gas passage 60 in the substantial gas flow direction (the left-right direction in FIG. 5), a rectangular cross-section extending along the gas flow direction is provided. A plurality of one convex portions 607 are formed at regular intervals.

On the other hand, in each of the concave portions 605 and 606,
A second convex portion 608 having a square cross section is located on the same straight line as the first convex portion 607 at a position near each exhaust hole 602, 604, that is, on the downstream side in the gas flow direction, and Are formed at predetermined intervals in the gas flow direction and the direction orthogonal to the same direction.

The first projection 607 and the second projection 6
Each of the reference numerals 08 denotes the anode 24 of the substrate 20 in a state where the current collector plate 10 and the substrate 20 are stacked as shown in FIG.
Is in contact with

Each of the recesses 605 and 606 has a first
A flow groove 900 for flowing the oxidizing gas is formed by the convex portion 607 and the second convex portion 608 of the first embodiment. The flow groove 900 is formed around the central axis C (see FIG. 5) of the current collector plate 10 extending in a direction orthogonal to the gas flow.
0 has the same shape symmetrical to the flow groove 800.

The oxidizing gas passage 60 is formed by each of the flow grooves 900. This oxidant gas passage 60
The length L1 (see FIG. 5) in the gas flow direction is twice (L2 × L2) the length L2 (see FIG. 5) in the direction orthogonal to the gas flow direction, similarly to the fuel gas passage 50.
It is set longer than 2). More specifically, the lengths L1 and L2 are set so that the relationship of L1 / L2> 2 holds. Thus, the current collector 10
By setting the lengths L1 and L2 of the gas passages 50 and 60 with the above relationship, the shape of the fuel cell 30 can be made flat, and the fuel cell 30 can be placed under the floor of a vehicle, for example. It can be mounted in a small space.

As shown in FIG. 6, the flow grooves 900 are
A parallel groove 901 formed between each first convex portion 607,
It is constituted by a lattice groove 902 formed between each second convex portion 608. The parallel groove 901 has a straight shape without a bent portion, and is located on the upstream side in the gas flow direction. On the other hand, the lattice groove 902 is
It is located downstream in the gas flow direction.

In each of the concave portions 605 and 606, a portion extending in the gas flow direction in the lattice groove 902 and the parallel groove 9 are provided.
A plurality of linear flow paths (hereinafter, referred to as “main flow paths”) 61 are formed by 01 and 01. These adjacent main flow paths 61 are connected to each other by flow paths (hereinafter, referred to as “communication paths”) 62 formed by portions of the lattice grooves 902 extending in a direction orthogonal to the gas flow direction. Since the lattice grooves 902 are formed only in the recesses 605 and 606 on the downstream side in the gas flow direction, the formation density of the communication path 62 is set to be higher on the downstream side than on the upstream side. That is, the degree of communication of the main flow path 61 by the communication path 62 is set to be relatively large toward the downstream side.

Next, the flow of the fuel gas and the oxidizing gas in the gas passages 50 and 60 in the current collector plate 10 configured as described above will be described. After the fuel gas is introduced into each of the concave portions 505 and 506 through each of the air supply holes 501 and 503 for the fuel gas passage 50, it flows through each parallel groove 801 and flows downstream. Similarly, the oxidizing gas is introduced into each of the recesses 605 and 606 through each of the supply holes 601 and 603 for the oxidizing gas passage 60, and then flows through each parallel groove 901 to the downstream side. Become.

In this way, the fuel gas which has moved to the downstream side of each parallel groove 801 is further discharged through the exhaust holes 502 and 504 after further passing through the lattice groove 802. Similarly, the oxidizing gas passes through the lattice grooves 902 from the parallel grooves 801 and is discharged through the exhaust holes 602 and 604.

Therefore, as shown by an arrow A in FIG.
A substantial flow of the fuel gas from the fuel gas 3 to the exhaust holes 502 and 504 is formed, and as shown by an arrow A in FIG. A substantial flow of the oxidizing gas from the pores 601 and 603 to the exhaust holes 602 and 604 is formed.

In addition to the substantial gas flow in each of the main flow paths 51 and 61, each of the gas passages 50 and 60
Has a communication passage 52 that connects the adjacent main flow passages 51 and 61,
Since the 62 is formed, a part of the gas diffuses in the direction orthogonal to the substantial flow direction of the gas through the communication passages 52 and 62 as shown by the arrow B in FIGS. 4 and 6. .

The degree of communication of the communication passages 52 and 62 is set to be relatively large toward the downstream side, so that the communication passages 52 and 62 are located downstream of the gas passages 50 and 60.
In 2, gas diffusion is further promoted, and liquefaction of water contained in the gas is suppressed. On the other hand, in the upstream portions of the gas passages 50 and 60, the degree of communication between the communication passages 52 and 62 is set relatively small, so that excessive diffusion is suppressed. Therefore, a decrease in the gas flow rate is suppressed, and the composition of the gas in contact with each reaction electrode can be made uniform.

As a result, the occurrence of blockage due to liquefied moisture in the downstream portions of the gas passages 50 and 60 is suppressed, and good power generation efficiency is maintained. Further, since the upstream side portions of the gas passages 50 and 60 are formed by straight parallel grooves 801 and 901 having no bent portions, they are in contact with the gas of the electrolyte membrane 22 as compared with, for example, lattice grooves. The surface area is reduced, and the total amount of water carried away from the electrolyte membrane 22 by the gas flowing through each gas passage 50, 60 is reduced. Further, the flow resistance when the gas passes through the upstream portion of each of the gas passages 50 and 60 is also reduced.

As a result, the water content of the portion of the electrolyte membrane 22 located on the upstream side of each of the gas passages 50 and 60 is suppressed from being excessively reduced, and good power generation efficiency is maintained. The pressure loss when passing through the passages 50 and 60 can be reduced.

Further, since the length L1 in the gas flow direction is set to be longer than the length L2 in the direction perpendicular to the gas flow direction, the gas passages 50 and 60 have the same length. The flow rate is increased, the composition of the gas in contact with each of the reaction electrodes 23 and 24 is made uniform, and good power generation efficiency is secured.

In particular, such an improvement in power generation efficiency is achieved by increasing the length L1 of each of the gas passages 50 and 60 in the gas flow direction and the length L2 in the direction perpendicular to the gas flow direction.
It has been confirmed by experiments by the inventor that the setting of L1 / L2> 2 makes the relationship more remarkable.

As described above, according to the present embodiment, the following functions and effects can be obtained. (1) Main flow paths 51, 6 adjacent to each gas path 50, 60
1 are formed, and the degree of communication between the main flow paths 51 and 61 by the communication paths 52 and 62 is set to be relatively large toward the downstream side. Occurrence of blockage due to liquefied water at the downstream side of the portion 60 can be suppressed, and good power generation efficiency can be maintained.

(2) Since the upstream portions of the gas passages 50 and 60 are formed by straight parallel grooves 801 and 901 having no bent portions, the upstream of the gas passages 50 and 60 in the electrolyte membrane 22 is formed. It is possible to maintain a good power generation efficiency by suppressing the water content of the portion located on the side from excessively decreasing, and to reduce a pressure loss when gas passes through each gas passage 50, 60. become able to.

(3) By setting the length L1 of each gas passage 50, 60 in the gas flow direction to be longer than the length L2 in the direction perpendicular to the gas flow direction,
The composition of the gas in contact with each of the reaction electrodes 23 and 24 can be made uniform to ensure good power generation efficiency.

(4) In particular, since the lengths L1 and L2 of the gas passages 50 and 60 are set to have a relationship of L1 / L2> 2, the operation and effect of the above (3) can be achieved. It can be even more prominent.

(5) In addition, the flow groove 800 forming the fuel gas passage 50 and the flow groove 900 forming the oxidizing gas passage 60 are connected to the central axis of the current collector plate 10 extending in a direction orthogonal to the gas flow direction. Since the current collector plate 10 and the substrate 20 were stacked, the surface where the fuel gas passage 50 was formed and the oxidant gas passage 60 were formed in the current collector plate 10 because the current collector plate 10 and the substrate 20 were stacked. The work of discriminating between surfaces is not required. Therefore, workability when laminating the current collector plate 10 and the substrate 20 can be improved.

The configuration of the current collector according to the above-described embodiment can be changed as follows. As shown in FIG. 7 or FIG. 8, in each of the concave portions 505 and 506 of the lamination surface facing the cathode 23 on the current collector plate 10,
A plurality of projections 509 whose length in the gas flow direction is set to be shorter toward the downstream side are formed.
9 form the fuel gas passage 50. Similarly, in each of the concave portions 605 and 606 of the laminated surface facing the anode 24 in the current collector plate 10,
A plurality of projections (not shown) are formed so that the length in the gas flow direction becomes shorter toward the downstream side, and the oxidizing gas passage 60 is formed by a flow groove (not shown) formed between these projections. Is configured.

With such a configuration, each gas passage 5
The communication degree of 0,60 can be set relatively large toward the downstream side, and the same operation and effect as the above embodiment can be obtained.

In particular, as shown in FIG.
By displacing the positions of the communicating portions 0, 60 (only the fuel gas passage 50 is shown in the figure) in the gas flow direction, the diffusion of the gas can be further promoted, and the liquefaction of the moisture contained in the gas is suppressed. Will be able to do it.

In the above embodiment, the second projection 508,
608 are arranged at regular intervals in the gas flow direction. However, the intervals at which the second protrusions 508 and 608 are arranged are increased toward the downstream side in the gas flow direction to increase the communication passage 52. , 62 may be set to be larger toward the downstream side, so that the degree of communication between the gas passages 50 and 60 may be set to be larger toward the downstream side in the gas flow direction.

In the above embodiment, each gas passage 50, 6
In addition, two air supply holes 501, 503, 601, 603 and exhaust holes 502, 504, 602, 604 are provided in the current collector 10 respectively, and each of the gas passages 50, 60 is formed in two.
Although the gas passages 50 and 60 are constituted by a single passage, the gas passages 50 and 60 may be constituted by a single passage.

In the above embodiment, the first projection 507,
607 has a rectangular cross-section and the second protrusions 508 and 608 have a square cross-section, but these protrusions 507, 607 and 5
08 and 608 are not limited to those having such a cross-sectional shape. For example, the first convex portions 507 and 607 may have an elliptical cross-sectional shape, and the second convex portions 508 and 608 may have a perfect circular cross-sectional shape.

In the above embodiment, the example of the current collector plate in which both the fuel gas passage and the oxidizing gas passage are formed has been described, but the current collector plate has only one of these gas passages formed. It may be something.

[Brief description of the drawings]

FIG. 1 is a perspective view showing a laminated structure of a fuel cell.

FIG. 2 is a partial sectional view taken along line 2-2 of FIG.

FIG. 3 is a plan view showing a fuel gas passage formed on a laminated surface of a current collector facing a cathode.

FIG. 4 is an enlarged plan view illustrating a flow groove constituting a fuel gas passage in an enlarged manner.

FIG. 5 is a plan view showing an oxidizing gas passage formed on a laminated surface of a current collector facing an anode.

FIG. 6 is an enlarged plan view showing a flow groove forming an oxidizing gas passage in an enlarged manner.

FIG. 7 is a plan view showing a configuration modification of a gas passage.

FIG. 8 is a plan view showing a modification of the configuration of the gas passage.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 ... Current collecting plate, 20 ... Substrate, 22 ... Electrolyte membrane, 23 ... Cathode, 24 ... Anode, 30 ... Solid polymer fuel cell, 50 ...
Fuel gas passage, 51 main passage, 52 communication passage, 60 oxidant gas passage, 61 main passage, 62 communication passage, 501 passage
1st air supply hole, 502 ... 1st exhaust hole, 503 ... 2nd air supply hole, 504 ... 2nd exhaust hole, 505, 506 ... concave part, 507 ... 1st convex part, 508 ... 2nd convexity Department, 509
.., Convex portion, 601 first air supply hole, 602 first air exhaust hole, 603 second air supply hole, 604 second air exhaust hole, 6
05, 606: concave portion, 607: first convex portion, 608: second convex portion, 701: water supply hole, 702: drain hole, 800 ...
Distribution grooves, 801: parallel grooves, 802: lattice grooves, 803: distribution grooves, 900: distribution grooves, 901: parallel grooves, 902: lattice grooves.

Claims (5)

[Claims] A fuel gas passage and an oxidant gas passage for flowing a fuel gas and an oxidant gas in opposite directions are used in a polymer electrolyte fuel cell provided on both sides of an electrolyte membrane. In a current collector plate of a polymer electrolyte fuel cell in which at least one of the gas passages is formed on a layered surface with the electrolyte membrane, the gas passage is constituted by a plurality of flow passages, and the communication passages communicate the adjacent flow passages. While multiple parts are formed,
A current collector plate for a polymer electrolyte fuel cell, wherein the degree of communication by the communication portion is set to be greater toward the downstream side in the gas flow direction. 2. The current collector plate of a polymer electrolyte fuel cell according to claim 1, wherein said gas passage has an upstream portion formed by parallel grooves and a downstream portion formed by lattice grooves. 3. The current collector plate of a polymer electrolyte fuel cell according to claim 2, wherein the parallel groove is formed in a straight line without a bent portion. 4. The solid polymer fuel according to claim 1, wherein the gas passage has a length L1 in a gas flow direction longer than a length L2 in a direction orthogonal to the gas flow direction. Battery current collector. 5. A length L1 in the gas flow direction and a length L2 in a direction perpendicular to the gas flow direction are L1 / L.
The current collector of the polymer electrolyte fuel cell according to claim 4, wherein the current collector is set to have a relationship of 2> 2.