JPH06325777A - Gas seal structural body for fuel cell - Google Patents

Abstract

PURPOSE:To prevent gas from leaking by holding a cell with sheet shaped gaskets so as to press the cell, and applying shearing force to the sheet shaped gaskets so as to bend them to the surface end directions. CONSTITUTION:Each sheet shaped gasket 14a and 14b which is so large as to be protruded out of the periphery of a cell 11, is disposed on both the sides of the cell. Each outside presser 16a and 16b having a hole 15 larger than the outer diameter of the cell 11 is disposed to the outsides of each gasket 14a and 14b respectively. These pressers 16a and 16b are flexible somewhat to press the gaskets 14a and 14b onto the end sections of the cell. Each separator 17a and 17b is disposed to the outside of each presser 16a and 16b. Force is so designed as to be exerted to the direction indicated by an arrow head by holding each presser 16a and 16b with the separators 17a and 17b for pressing them. Each gasket 14a and 14b is subjected to shearing force by the end sections of the cell 11 and the pressers 16a and 16b, so that each gasket is thereby closely attached to the end sections of the cell.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a gas seal structure for a fuel cell using a solid polymer electrolyte membrane.

[0002]

2. Description of the Related Art Conventionally, in a fuel cell using a solid polymer electrolyte membrane, a liquid sealing agent is applied to the cell end portion, dried, and then sandwiched between separators and tightened.
It was preventing gas leaks. This is shown in FIG.
This will be described with reference to (B). FIG. 2 (A) shows a cell 4 in which a solid polymer electrolyte membrane 1 is sandwiched between gas diffusion electrodes 2 and 3 from above and below. First, the sealant 5 was applied to the side surface, the upper peripheral portion, and the lower peripheral portion of the cell 4 (see FIG. 2 (B)), and gas leakage from the end portion of the cell 4 was attempted.

[0003]

However, as shown in FIG.
When the sealant 5 is applied as shown in FIG.
As shown in (C), when the cell 4 coated with the sealing agent 5 is sandwiched between the upper and lower separators 6 and 7 to be laminated, the sealing agent 5
And the separators 6 and 7 do not hit well, and a leak occurs.

Therefore, in order to prevent leakage, it is necessary to apply the sealant 5 uniformly and evenly. Further, when the cell 4 has flexibility, the sealant 5 and the cell end cannot come into contact with each other, and, for example, stop the gas leaked to the other gas diffusion electrode 2 side of the gas that has permeated through the gas diffusion electrode 3. Cannot be performed (see FIG. 2D).

The present invention has been made in consideration of the above circumstances, and prevents leakage when the cells are sandwiched by the separators and laminated, and when the cells are flexible, the gas diffusion electrode from one of the cells to the other of the cells can be prevented. It is an object of the present invention to provide a gas seal structure for a fuel cell, which can prevent gas leakage to the gas diffusion electrode.

[0006]

The present invention is directed to a fuel cell power generator comprising a solid polymer electrolyte membrane and gas diffusion electrodes arranged on both sides of the solid polymer electrolyte membrane, and to both the fuel cell power generator and the fuel cell power generator. Sheet-shaped gaskets respectively arranged on the surface side and having a size protruding from the edge of the fuel cell power generator, and respectively arranged outside the sheet-shaped gasket, and the gasket is arranged from the outside to the edge of the fuel cell power generator and A gas seal structure for a fuel cell, characterized in that the gas seal structure is provided with an outer pressing means that is brought into close contact with the end face portion.

In the present invention, the outer pressing means may be composed of an outer pressing member and a separator which are separated from each other as shown in FIG. 1, or a unit in which the outer pressing member and the separator are integrated.

[0008]

In the present invention, by sandwiching the cell with the sheet-like gasket and pressing it with the outer pressing means, it is possible to prevent the leak between the cell and the outer pressing means. Further, a shearing force is applied to the sheet-like gasket to bend it toward the cell end face and bring it into close contact with the cell end face, thereby eliminating the gap and preventing gas leaking through the gas diffusion electrode of the cell from leaking.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS.
This will be described with reference to (C). Here, FIG. 1A is a development view of a gas seal structure of a fuel cell according to this embodiment, FIG. 1B is a cross-sectional view of a main part of a laminated gas seal structure, and FIG. FIG. 4 is an explanatory diagram showing a force generation state in a laminated gas seal structure. Reference numeral 11 in the figure is a rectangular fuel cell power generator (cell). This cell 11
The solid polymer electrolyte membrane 12 and the gas diffusion electrodes 13a and 13b arranged on the upper and lower surfaces of the solid polymer electrolyte membrane 12, respectively. Sheet-like gaskets 14a, 14b having a thickness of 0.5 mm and having a size protruding from the edge of the cell 11 are arranged on both main surface sides of the cell 11. Outside the sheet-like gaskets 14a, 14b, outside pressers 16a, 16b having holes 15 larger than the outer diameter of the cell 11 are arranged, respectively. The outer pressers 16a and 16b are used to press the sheet-like gaskets 14a and 14b against the cell ends, and are used to have elasticity to some extent. Separators 17a and 17b are provided outside the outer pressers 16a and 16b.
Are arranged. Here, the outer pressing means and the separator constitute outer pressing means.

In this embodiment, the outer pressers 16a and 16b are sandwiched between the separators 17a and 17b and compressed, so that
A force was generated in the direction of the arrow shown in (C). The sheet-like gaskets 14a, 14b are subjected to shear stress by the ends of the cells 11 and the outer pressers 16a, 16b,
It adheres to the cell end face.

Although not shown, a flange or the like (not shown) is arranged on the outside of the separator, and the separator is tightened with bolts and nuts. Further, FIG. 1A shows a case of a single cell, and generally has a stack structure in which separators and cells are alternately laminated and tightened with bolts and nuts.

As shown in FIG. 1, the gas seal structure for a fuel cell according to the above-mentioned embodiment comprises a solid polymer electrolyte membrane 12 and gas diffusion electrodes 13a arranged on the upper and lower surfaces of the solid polymer electrolyte membrane 12. A rectangular cell 11 composed of 13b and the cell 11
Sheet-like gaskets 14a, 14b having a thickness of 0.5 mm arranged on both main surface sides of the sheet-like gaskets, and the sheet-like gaskets 14a, 14
Outer retainers 16a, 16b, which are arranged on the outer side of b and have a hole 15 larger than the outer diameter of the cell 11 and have elasticity to some extent.
And separators 17a and 17b arranged outside the outer pressers 16a and 16b, and the outer pressers 16a and 16b are also sandwiched between the separators 17a and 17b and compressed, thereby
It is configured to generate a force in the arrow direction shown in (C). Therefore, unlike the conventional cell, it is not necessary to apply the sealant, and the productivity is improved. Further, the flexible sheet-like gaskets 14a and 14b are used to sandwich the edge portion and the end face portion of the cell 11, and further, the sheet-like gaskets 14a and 14b.
Since the b is sealed by the outer pressers 16a and 16b for sealing, gas leakage can be reliably prevented.

In the above embodiment, the sheet-like gasket having a thickness of 0.5 mm is used. However, the present invention is not limited to this, and if the gasket has a large flexibility, a thicker gasket may be selected.

[0014]

As described above in detail, according to the present invention,
Prevents leaks when stacking cells by sandwiching them with separators and prevents gas leaks from one gas diffusion electrode of the cell to the other gas diffusion electrode when the cell is flexible, further improving productivity A gas seal structure for a fuel cell can be provided.

[Brief description of drawings]

1 is an explanatory view of a gas seal structure of a fuel cell according to an embodiment of the present invention, FIG. 1 (A) is a development view of the gas seal structure, and FIG. 1 (B) is a laminated gas seal. Sectional drawing of the principal part of a structure, FIG.1 (C) is explanatory drawing which shows the generation | occurrence | production state of the force in the laminated gas seal structure. The block diagram which shows the whole structure of one Example of this invention.

FIG. 2 is an explanatory view of a conventional cell, FIG. 2 (A) is a perspective view of the cell, FIG. 2 (B) is an explanatory view of a state in which a sealing agent is attached to the cell, and FIG. 2 (C) is the same. Explanatory drawing showing the situation of leakage when sandwiching a cell with a separator, FIG. 2 (D) is an explanatory view showing the situation of gas leakage when the cell has flexibility.

[Explanation of symbols]

11 ... Cell, 12 ... Solid polymer electrolyte membrane, 13a, 13b ... Gas diffusion electrode, 14a, 14
b ... Sheet gasket, 16a, 16b ... Outer retainer,
17a, 17b ... Separator.

Claims (1)

[Claims] 1. A fuel cell power generator comprising a solid polymer electrolyte membrane and gas diffusion electrodes disposed on both sides of the solid polymer electrolyte membrane, and a fuel cell power generator disposed on both main surface sides of the fuel cell power generator, respectively. A sheet-like gasket having a size protruding from the edge of the fuel cell power generator, and outer pressing means arranged respectively on the outer side of the sheet-like gasket and closely contacting the gasket with the edge and the end face of the fuel cell power generator from the outside. A gas seal structure for a fuel cell, comprising: