JP2002042835A - Sealing structure of fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sealing structure of a fuel cell easily preventing the deviation relative to a separator at a low cost. SOLUTION: This sealing structure for the fuel cell prevents the leakage of liquid from the separators 10 of the stack formed by laminating a plurality of cells, which are formed by sandwiching electrolytes between electrodes via the separators 10. Elastic films 19 having elasticity are integrally provided in both faces of one and the other of the separator 10 so as to dispose a gasket 20 between the adjoining separators 10.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell sealing structure for preventing a fluid from leaking from between separators of a stack in which a plurality of cells having an electrolyte sandwiched between electrodes are stacked via a separator.

[0002]

2. Description of the Related Art In a solid polymer electrolyte fuel cell, a plurality of cells and separators, each having a solid polymer electrolyte sandwiched between an air electrode and a hydrogen electrode, are alternately stacked to form a stack. When supplied, air is supplied to the air electrode of each cell from the air flow channel formed on one surface of each separator, and hydrogen is supplied from the hydrogen flow channel formed on the other surface of each separator. Supplied to the hydrogen electrode of the cell,
Electric power can be obtained by electrochemically reacting the air (oxygen) and hydrogen in the cell.

In such a fuel cell stack, in order to prevent leakage of a fluid such as air or hydrogen from between adjacent separators, a contact portion with a flow portion (a manifold portion) of a fluid such as air or hydrogen or a cell is provided. A gasket formed by stamping and molding a plate-like rubber material with a mold or the like so as to remove a portion (flow channel groove portion) is sandwiched between the gaskets and sealed.

[0004]

In the above-described fuel cell seal structure, the gasket and the cell are sandwiched between the separators and a plurality of the gaskets are stacked and then fastened. There was a risk that the sealing performance would be reduced. For this reason, the surface of the separator is polished to improve the flatness, thereby improving the adhesiveness between the separator and the gasket. However, it is very troublesome and the cost is increased.

[0005] In view of the above, an object of the present invention is to provide a seal structure for a fuel cell, which can easily prevent displacement with respect to a separator at low cost.

[0006]

Means for Solving the Problems In order to solve the above-mentioned problems, a fuel cell sealing structure according to a first aspect of the present invention is a fuel cell sealing structure in which a plurality of cells having an electrolyte sandwiched between electrodes are stacked via a separator. A fuel cell seal structure for preventing leakage of fluid from between separators, wherein an elastic film having elasticity is integrally provided on one surface of the separator.

A fuel cell seal structure according to a second invention is characterized in that, in the first invention, an elastic film having elasticity is integrally provided on the other surface of the separator.

A third aspect of the present invention provides a fuel cell seal structure according to the first or second aspect, wherein a gasket is provided between the adjacent separators.

A fourth aspect of the present invention provides a fuel cell seal structure according to the first aspect, wherein the thickness of the elastic membrane is larger than the thickness of the cell.

A fifth aspect of the present invention provides a fuel cell sealing structure according to the second aspect, wherein the thickness of the elastic membrane is larger than half the thickness of the cell.

A sixth aspect of the present invention provides the fuel cell seal structure according to any one of the first to fifth aspects, wherein the elastic film is formed of a urethane resin or liquid silicon printed on the surface of the separator by screen printing. The rubber is cured by heating.

The fuel cell seal structure according to a seventh aspect of the present invention is the fuel cell seal structure according to any one of the first to fifth aspects, wherein the elastic film is formed by photo-curing resin printed on the surface of the separator by screen printing. And cured by irradiation.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the fuel cell seal structure according to the present invention will be described below, but the present invention is not limited to these embodiments.

[First Embodiment] FIGS. 1 and 2 show a first embodiment of a fuel cell sealing structure according to the present invention.
This will be described with reference to FIG. FIG. 1 is a schematic configuration diagram of a seal structure,
FIG. 2 is a diagram illustrating the operation of the seal structure.

As shown in FIGS. 1 and 2, the sealing structure of a fuel cell according to the present embodiment has a structure in which a plurality of cells having an electrolyte sandwiched between electrodes are stacked with a separator 10 interposed therebetween. A fuel cell seal structure for preventing leakage of the fuel cell, wherein an elastic film 19 having elasticity is integrally provided on one and the other surfaces of the separator 10,
The gasket 20 is provided between the adjacent separators 10. The details will be described below.

As shown in FIG. 1, the separator 10 includes:
Air supply manifold 11, hydrogen supply manifold 1
2. A cooling water delivery manifold 13, an air delivery manifold 14, a hydrogen delivery manifold 15, and a cooling water supply manifold 16 are formed so as to penetrate one surface and the other surface. On one surface of the separator 10, an air passage groove 17 through which air flows while meandering is provided.
Are formed. On the other surface of the separator 10, a hydrogen flow channel 18 for flowing hydrogen while meandering is formed.

The air supply manifold 11 and the air passage groove 17 are connected by a communication groove (not shown) formed inside the separator 10. Between the air delivery manifold 14 and the air flow channel 17,
The connection is established by a communication groove (not shown) formed inside the separator 10. The hydrogen supply manifold 12
A communication groove (not shown) formed in the interior of the separator 10 connects between the hydrogen flow groove 18 and the hydrogen flow groove 18. The hydrogen delivery manifold 15 and the hydrogen flow channel 1
8 are connected to each other by a communication groove (not shown) formed inside the separator 10.

Inside the separator 10, a not-shown cooling water passage groove communicating between the cooling water delivery manifold 13 and the cooling water supply manifold 16 is formed so as to meander inside the separator.

On both surfaces of the separator 10, an elastic film 19 made of an elastic material such as a resin is used to form the manifolds 11 to 16 and the flow grooves 17, 18.
Is covered so as to remove the peripheral portion of the. The elastic film 19 is provided on the manifolds 11 to 1 of the separator 10.
6 and a photo-curable resin (for example, the product name “3” manufactured by Three Bond Co., Ltd.) on the surface of the separator 10 with a screen formed with a pattern corresponding to the flow channel grooves 17 and 18.
1X ") or urethane-based resin or liquid silicon rubber (for example," 1230G "(trade name, manufactured by Three Bond Co., Ltd. as liquid silicon rubber)) and the like, and then irradiated with light (for example, ultraviolet rays) or heated. By curing, it can be easily formed at low cost.

A plurality of such separators 10 are disposed such that one surface of the separator 10 on which the elastic film 19 is formed and the other surface thereof are opposed to each other, and the solid polymer electrolyte is supplied to the air electrode and the air electrode. The air electrode side of the cell sandwiched between the hydrogen electrodes faces the air flow channel groove 17 of the separator 10, in other words, the hydrogen electrode side of the cell faces the hydrogen flow channel 1 of the separator 10.
8 are arranged between the separators 10 so as to face the manifolds 8, and the manifolds 11 to 16
A plate-like gasket 20 punched out so as to remove a portion and a peripheral portion of each of the flow grooves 17 and 18 is disposed between the separators 10 and tightened and fastened to seal between adjacent separators 10. A fuel cell stack is constructed (see FIG. 2).

In such a fuel cell stack, when air is supplied to the air supply manifold 11 and hydrogen is supplied to the hydrogen supply manifold 12, the air flows through the air flow groove 17 through the communication groove. Hydrogen is supplied to the air electrode of the cell, hydrogen is supplied to the hydrogen electrode of the cell by flowing through the hydrogen flow groove 18 through the communication groove, and air (oxygen) and hydrogen electrochemically react in the cell. To generate power. The unreacted excess air flows through the air delivery manifold 14 via the communication groove and is discharged to the outside, and the unreacted excess hydrogen flows through the hydrogen delivery manifold 15 via the communication groove. Is discharged outside.

On the other hand, when the cooling water is supplied to the cooling water supply manifold 16, the cooling water flows through the cooling water flow channel formed inside the separator 10 to cool the cells and the like, and then the cooling water delivery manifold 13 to the outside.

In such a fuel cell stack, since the separator 10 is coated on both sides with the elastic film 19 as described above, the gasket 20 comes into close contact with the elastic film 19. , Separator 1
Even if a plurality of 0s and cells are alternately stacked and fastened, the gasket 20 does not shift with respect to the separator 10.

Thus, the adhesion between the separator 10 and the gasket 20 can be improved without polishing the surface of the separator 10.

Therefore, according to such a sealing structure, the displacement of the gasket 20 with respect to the separator 10 can be easily prevented at low cost.

It is to be noted that the gasket 20 is not limited to a mere flat plate, but may be a gasket having a hole surrounding a bead.
In this case, the beads come into the elastic film 19, so that the sealing performance can be further improved.

In this embodiment, the separator 10
Although the elastic film 19 is formed on both surfaces of the separator 10, depending on the flatness of the surface of the separator 10, the same effect as in the present embodiment can be obtained by forming the elastic film 19 only on one surface of the separator 10. Can be obtained.

[Second Embodiment] A second embodiment of the fuel cell seal structure according to the present invention will be described with reference to FIG. FIG. 3 is a diagram illustrating the operation of the seal structure. However, the same members as those in the first embodiment described above are denoted by the same reference numerals as those used in the description of the first embodiment, and the description thereof is omitted.

As shown in FIGS. 1 and 2, the seal structure of the fuel cell according to the present embodiment has a structure in which a plurality of cells in which an electrolyte is sandwiched between electrodes are stacked via a separator 10. A fuel cell seal structure for preventing leakage of the fuel cell, wherein an elastic film 19 having elasticity is integrally provided on one and the other surfaces of the separator 10,
The thickness of the elastic film 10 was made larger than half the thickness of the cell. The details will be described below.

As shown in FIG. 3, both surfaces of the separator 10 are covered with an elastic film 29.
The thickness is thicker than the elastic film 19 of the first embodiment described above, and is slightly larger than half of the interval (cell thickness) between the adjacent separators 10.
Such an elastic film 29 can be easily formed by performing the same screen printing as in the first embodiment a plurality of times and applying the resin or the like repeatedly.

A plurality of such separators 10 are provided so that one surface of the separator 10 on which the elastic film 29 is formed and the other surface thereof are opposed to each other. And the air electrode side of the cell sandwiched between the hydrogen electrodes is opposed to the air flow channel groove 17 of the separator 10,
In other words, the cell is placed on the separator 1 such that the hydrogen electrode side of the cell faces the hydrogen flow channel 18 of the separator 10.
By arranging and tightening the fuel cells between the zeros, a fuel cell stack in which the space between the adjacent separators 10 is sealed is formed (see FIG. 3).

That is, in the first embodiment described above, the gasket 20 is interposed using the thin elastic film 19, but in the present embodiment, the thick elastic film 29 is provided. To omit the gasket 20, ie,
The elastic film 29 also serves as the gasket 20.

Therefore, according to this embodiment, the same effects as those of the first embodiment can be obtained, and the gasket 20 is not required. Work can be simplified.

In the present embodiment, the elastic films 29 having a thickness slightly larger than half of the interval (cell thickness) between the adjacent separators 10 are formed on both surfaces of the separators 10. Even if an elastic film having a thickness slightly larger than the interval (cell thickness) between the adjacent separators 10 is formed on one surface of the separator 10, the same effect as that of the present embodiment can be obtained. Can be. However,
Forming an elastic film having such a thickness by screen printing requires a great deal of time and effort, and therefore, it is preferable to use the method as in the present embodiment.

[0035]

According to the first aspect of the present invention, there is provided a fuel cell sealing structure for preventing a fluid from leaking from between the separators of a stack in which a plurality of cells having an electrolyte sandwiched between electrodes are stacked via a separator. In the seal structure, since an elastic film having elasticity is integrally provided on one surface of the separator, even if a plurality of separators and cells are alternately laminated and fastened, the elastic film is formed on the separator. Since there is no deviation, it is possible to prevent a decrease in sealing performance due to a deviation at the time of stack fastening.

In the fuel cell seal structure according to the second aspect of the present invention, in the first aspect of the invention, in the first aspect of the present invention, an elastic film having elasticity is integrally provided on the other surface of the separator. A decrease in sealing performance can be prevented more reliably.

According to the third aspect of the present invention, the gasket is disposed between the adjacent separators in the first or second aspect, so that the thickness of the elastic film can be reduced. The first and second inventions can be easily implemented.

According to the fourth aspect of the present invention, in the fuel cell seal structure according to the first aspect, since the thickness of the elastic film is larger than the thickness of the cell, the gasket can be omitted, and the stack can be assembled. Can be simplified.

According to the fifth aspect of the present invention, in the fuel cell seal structure according to the second aspect, the gasket can be omitted since the thickness of the elastic membrane is larger than half the thickness of the cell. Thus, the work of assembling the stack can be simplified.

A sixth aspect of the present invention provides the fuel cell seal structure according to any one of the first to fifth aspects, wherein the elastic film is formed of a urethane resin or liquid silicon printed on the surface of the separator by screen printing. Since the rubber is cured by heating, the elastic film can be easily formed on the surface of the separator.

According to a seventh aspect of the present invention, there is provided a fuel cell seal structure according to any one of the first to fifth aspects, wherein the elastic film is formed by photo-curing resin printed on the surface of the separator by screen printing. Is irradiated and cured, so that the elastic film can be easily formed on the surface of the separator.

[Brief description of the drawings]

FIG. 1 is a schematic configuration diagram of a first embodiment of a fuel cell seal structure according to the present invention.

FIG. 2 is an operation explanatory view of the seal structure of FIG. 1;

FIG. 3 is an operation explanatory view of a second embodiment of the fuel cell seal structure according to the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Separator 11 Air supply manifold 12 Hydrogen supply manifold 13 Cooling water delivery manifold 14 Air delivery manifold 15 Hydrogen delivery manifold 16 Cooling water supply manifold 17 Air flow groove 18 Hydrogen flow groove 19, 29 Elastic film 20 Gasket

Claims (7)

[Claims] 1. A fuel cell seal structure for preventing leakage of fluid from between separators of a stack in which a plurality of cells having an electrolyte sandwiched between electrodes are interposed via a separator, wherein one side of the separator has A sealing structure for a fuel cell, wherein an elastic film having elasticity is integrally provided. 2. The fuel cell sealing structure according to claim 1, wherein an elastic film having elasticity is integrally provided on the other surface of the separator. 3. The fuel cell sealing structure according to claim 1, wherein a gasket is provided between the adjacent separators. 4. The fuel cell sealing structure according to claim 1, wherein the thickness of the elastic membrane is larger than the thickness of the cell. 5. The fuel cell sealing structure according to claim 2, wherein the thickness of the elastic membrane is larger than half the thickness of the cell. 6. The method according to claim 1, wherein the elastic film is obtained by heating and curing a urethane-based resin or liquid silicone rubber printed on the surface of the separator by screen printing. Characteristic fuel cell seal structure. 7. The elastic film according to claim 1, wherein the elastic film is formed by irradiating light to a photocurable resin printed on the surface of the separator by screen printing. Fuel cell seal structure.