JP3292670B2 - Fuel cell - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to relates to fuel cells for sealing the electrolyte membrane.

[0002]

2. Description of the Related Art For example, a fuel cell has been developed in which a plurality of fuel cell structures each having an anode electrode and a cathode electrode facing each other with a solid polymer electrolyte membrane interposed therebetween are sandwiched by separators and stacked. It is being put to practical use for various applications.

A fuel cell of this type supplies a fuel gas (hydrogen) to an anode electrode and supplies an oxidant gas (air or oxygen) to a cathode electrode.
The fuel gas is ionized and flows through the solid polymer electrolyte membrane, whereby electric energy is obtained outside.

In this case, in the fuel cell, it is necessary to maintain the solid polymer electrolyte membrane in an appropriate wet state in order to exhibit an effective power generation function. Therefore, by preparing a humidifying device for humidifying the fuel gas and the oxidizing gas with water in advance and connecting the humidifying device to the fuel cell, the humidifying fuel gas and the oxidizing gas can be used in the fuel cell structure. What supplies the body is known.

[0005] The humidifier generally includes a first laminated body in which both surfaces of a water-permeable membrane are sandwiched between a separator having a fuel gas flow path and a separator having a humidified water flow path, and another water-permeable membrane. It is configured by alternately laminating a second laminated body in which both surfaces of the membrane are sandwiched between a separator having an oxidizing gas flow path formed therein and a separator having a humidified water flow path formed therein.

By the way, in a fuel cell and a humidifier,
It is necessary to hermetically seal the gas so that the fuel gas and the oxidizing gas do not leak from the periphery of the solid polymer electrolyte membrane and the water-permeable membrane. For this reason, generally, a seal structure in which an O-ring is provided on the periphery of the solid polymer electrolyte membrane and the water-permeable membrane is employed.

[0007]

However, in the fuel cell and the humidifier, an extremely thin film-like thin film, for example, an ion exchange membrane is used as the solid polymer electrolyte membrane and the water-permeable membrane. For this reason, as shown in FIG.
It has been pointed out that if the relative positions of a and 4b fluctuate due to errors and deviations due to processing and assembling, the thin film body 2 is easily deformed and damaged, and in some cases, damaged. Moreover, the positions of the O-rings 4a and 4b are shifted from each other, and there is a possibility that a reliable sealing property cannot be obtained.

Therefore, as disclosed in Japanese Patent Application Laid-Open No. 8-148170, there is known a sealing method in which a peripheral portion of an electrode is densified and a gas seal is performed by the densified portion. However, in the above prior art, during the manufacturing process of the electrode, it is necessary to perform a densification treatment with a densifying agent, and the manufacturing process of the electrode becomes complicated, and the problem that the manufacturing cost rises is pointed out. I have.

[0009] The present invention is intended to solve this kind of problem, with a simple structure, thereby effectively preventing damage to the electrolyte membrane, fuel cells capable of obtaining a reliable sealability
The purpose is to provide.

[0010]

In order to solve the above-mentioned problems, the present invention is directed to a first and a second sealing members, which are disposed on both sides of an electrolyte membrane so as to face each other, the width of each contact surface portion. The dimensions are set differently. That is, the first
The entire contact surface portion of the seal member is disposed within the contour of the contact surface portion of the second seal member opposed to the second seal member. Can be absorbed by the difference. This makes it possible to securely fix the electrolyte membrane without damaging it, and to ensure good sealing properties.

[0011]

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Figure 1 is engaged Ru fuel cell 1 to the onset bright
FIG. 2 is a schematic vertical cross-sectional explanatory view of a state where a seal structure 10 is incorporated in FIG.

The fuel cell 12 includes a fuel cell structure 14 and
First and second separators 16 and 18 sandwiching the fuel cell structure 14 are provided, and a plurality of these are stacked as necessary. The fuel cell structure 14 has, for example, a solid polymer electrolyte membrane 20 made of an ion exchange membrane, and an anode 22 and a cathode 24 disposed with the electrolyte membrane 20 interposed therebetween.

The first separator 16 has a substantially rectangular shape, and a first opening 26 for supplying a fuel gas (for example, hydrogen) to the anode 22 is formed in the center of the first separator 16. A first concave portion 28 for accommodating the anode 22 is formed on the mating surface side of the first separator 16, and a first seal groove having a rectangular opening cross section surrounding the first concave portion 28. 30 are provided.

The second separator 18 includes the first separator 1
6, a second portion for supplying an oxidizing gas (for example, air or oxygen) to the cathode electrode 24 at the center thereof.
An opening 32 is formed. On the mating surface of the second separator 18, a second recess 34 for accommodating the cathode-side electrode 24, a second recess 34 surrounding the second recess 34, and a second recess 34 facing the first seal groove 30 of the first separator 16. Two seal grooves 36 are provided. The first seal groove 30 is set to have a width smaller than the width of the second seal groove 36 and is provided along the inside of the second seal groove 36.

The seal structure 10 includes first and second seal members 38 and 40 provided in the first and second seal grooves 30 and 36 of the first and second separators 16 and 18. As shown in FIGS. 1 and 2, the first and second seal members 38 and 40 are square rings having a rectangular cross section, and constitute an elastic seal made of a resin material.

The first seal member 38 has a planar first contact surface portion 42 that directly contacts the electrolyte membrane 20, and as shown in FIG. 3, the width dimension H1 of the first contact surface portion 42 is set. I have. The second sealing member 40 has a planar second
The second contact surface portion 44 has a contact surface portion 44.
Are set to a predetermined width dimension H2 (> H1) as shown in FIG. The first seal member 38 is held on the inner wall surface of the first seal groove 30 of the first separator 16 via the double-sided tape 46, while the second seal member 40 is formed of the second seal groove 36 of the second separator 18. Double-sided tape 4 on inner wall
8 are held. The double-sided tape 46, 4
Instead of 8, an adhesive or the like may be used.

As shown in FIGS. 3 and 4, the first and second seal members 38 and 40 face each other with the fuel cell structure 14 interposed therebetween.
The entire first contact surface portion 42 is disposed within the contour shape of the second contact surface portion 44 of the second seal member 40 facing the first contact surface portion 42.

[0019] In such a configuration Resid Lumpur structure 10, first and second seal members 38 and 40, while being configured rectangular cross section of the square ring, the first contact of the first seal member 38 The width dimension H1 of the surface portion 42 is set smaller than the width dimension H2 of the second contact surface portion 44 of the second seal member 40. When the first and second seal members 38 and 40 face each other so as to sandwich the fuel cell structure 14, the entire first contact surface portion 42 of the first seal member 38 becomes the second contact member of the second seal member 40. 2 contact surface part 44
(See FIGS. 3 and 4).

As a result, even if the first and second seal members 38 and 40 are displaced relative to each other due to processing and assembly, they can be absorbed by the difference between the widths H1 and H2. The first seal member 38 does not protrude outside the contour of the second contact surface portion 44 of the second seal member 40. Therefore, with a very simple configuration,
There is an effect that damage to the electrolyte membrane 20 can be reduced as much as possible without damaging the electrolyte membrane 20 which is a thin film body. Moreover, the electrolyte membrane 20 can be securely fixed by the first and second seal members 38 and 40, and good sealing performance is ensured to effectively prevent leakage of fuel gas and oxidizing gas. be able to.

The first and second separators 16, 1
Although the first and second seal members 38, 40 are provided in the figure 8, the first and second seal members 38, 40 may be interchanged.

FIG. 5 is a schematic longitudinal sectional view of the humidifying device 60 in which a seal structure 10a replacing the seal structure 10 is incorporated .

The humidifying device 60 is moved in the laminating direction (the direction of the arrow X).
, A first supply plate (first separator) 62 for fuel gas, a first water permeable membrane 64a, a second supply plate (second separator) 66 for humidified water, and a second water permeable membrane 64b
A third supply plate (first separator) 68 for oxidant gas and fuel gas, a third water permeable membrane 64c, the second supply plate 66, a fourth water permeable membrane 64d, And a fourth supply plate (first separator) 70 are integrally disposed, and end plates (not shown) are provided at both ends in the stacking direction.

A plurality of projections 72 extending in the horizontal direction are provided on one surface of the first supply plate 62, so that the fuel gas meandering vertically in one surface of the first water permeable membrane 64a. A channel 74a is formed. A fuel gas passage 76a, a humidifying water passage 76b, and an oxidizing gas passage 76c are formed below the first supply plate 62, and a fuel gas passage 78a, a humidification A water passage 78b and an oxidizing gas passage 78c are formed. The fuel gas passages 76a and 78a are provided with grooves (not shown).
Through the fuel gas flow path 74a.

On both sides of the first supply plate 62, a fuel gas passage 76a and a humidification water passage 7
6b, the oxidizing gas passage 76c, and the fuel gas passage 78
a, the first seal grooves 80a, 80b and the second seal grooves 82a, 82b are formed so as to surround the humidified water passage 78b and the oxidizing gas passage 78c. First seal groove 80
The opening widths of a and 80b are set smaller than the opening widths of the second seal grooves 82a and 82b.

The first water permeable membrane 64a is made of, for example, an ion exchange membrane, and has a fuel gas passage 84 at its lower side.
a, a humidifying water passage 84b and an oxidizing gas passage 84c are formed therethrough, and a fuel gas passage 86a,
The humidification water passage 86b and the oxidizing gas passage 86c are formed to penetrate. The second to fourth water permeable membranes 64b to 64d are the first
The configuration is the same as that of the water permeable membrane 64a, and a detailed description thereof is omitted.

The second supply plate 66 has a plurality of projections 88a and 88b extending in the horizontal direction on both surfaces.
Water flow passages 90a, 90b are formed between a, 88b and the other surfaces of the first and second water permeable membranes 64a, 64b.
A fuel gas passage 92a, a humidifying water passage 92b, and an oxidizing gas passage 92c are formed through a lower portion of the second supply plate 66, and a fuel gas passage 94a, The humidification water passage 94b and the oxidizing gas passage 94c are formed to penetrate. Humidifying water passages 92b, 94
b communicates with the water flow paths 90a and 90b via grooves (not shown) on both surfaces of the second supply plate 66, respectively. On both sides of the second supply plate 66, a first seal groove 96a, 96b and a second seal groove 98
a and 98b are formed.

The third supply plate 68 has a plurality of projections 100a and 100b extending in the horizontal direction on both surfaces thereof. Between the projection 100a and one surface of the second water permeable membrane 64b,
An oxidizing gas channel 102a is formed, and a fuel gas channel 74b is formed between the protrusion 100b and one surface of the third water permeable membrane 64c. On the lower and upper sides of the third supply plate 68, fuel gas passages 104a and 106a, humidification water passages 104b and 106b, and oxidant gas passages 104c,
106c is formed through. An oxidizing gas passage 104c;
106c is an oxidizing gas flow path 1 through a groove (not shown).
02a and the fuel gas passages 104a,
06a is provided with a fuel gas flow path 74 through a groove (not shown).
b. On both surfaces of the third supply plate 68, first seal grooves 108a and 108b and second seal grooves 110a and 110b are formed on the lower side and the upper side.

The third water-permeable membrane 64c and the fourth water-permeable membrane 64
The second supply plate 66 is arranged between the second supply plate 66 and d. Both surfaces of the second supply plate 66 and the third and fourth water permeable membranes 64c, 64d
The water flow paths 90c and 90d are formed between the other surfaces.

The fourth supply plate 70 is provided with a plurality of projections 112 extending in the horizontal direction on one surface thereof, so that an oxidant gas flow is provided between the projections 112 and one surface of the fourth water permeable membrane 64d. A path 102b is formed.

On the lower and upper sides of the fourth supply plate 70, fuel gas passages 114a and 116a,
4b, 116b and oxidant gas passages 114c, 116
c is formed, and the oxidizing gas passages 114c, 116c
Communicates with the oxidizing gas channel 102b via a not-shown groove. First seal grooves 118a and 118b and second seal grooves 120a and 120b are formed on both surfaces of the fourth supply plate 70 at lower and upper portions thereof.

The seal structure 10a includes a first seal groove 80
a, 80b, 96a, 96b, 108a, 108b and 118a, 118b
2, the second seal grooves 82a, 82b, 98a, 98b,
110a, 110b and second sealing members 124 disposed on 120a, 120b. First and second
The seal members 122 and 124 form a square ring having a rectangular cross section, and are formed of an elastic resin material.

As shown in FIG. 6, the first seal member 122
The width H3 of the planar first contact surface portion 126 is set to be smaller than the width H4 of the planar second contact surface portion 128 of the second seal member 124. The entire first contact surface portion 126 is formed by the second contact surface portion 12 of the opposed second seal member 124.
8 are arranged in the outline shape.

[0034] In such a configuration Resid Lumpur structure 10a, the first and second seal members 122, 124, FIG. 6
As shown in the figure, the first and second planar contact surface portions 126 and 128 are respectively connected to the first to fourth water permeable membranes 64a to 64.
d and contact the first contact surface portion 12
6 are all accommodated in the contour of the second contact surface portion 128.

Accordingly, similarly to the above-described seal structure 10, the seal structure 10a includes the first and second seal members 12a.
Even if there is a relative displacement between 2, 124, it can be absorbed by the dimensional difference. Thereby, without damaging the first to fourth water permeable membranes 64a to 64d,
It is possible to obtain an effect that it is possible to securely fix and secure a good sealing property.

[0036]

As is evident from the foregoing description, together with <br/> in fuel cells according to the present invention, cross-section rectangular first and second seal members are disposed on both sides of the electrolyte membrane, the first The entire contact surface of the seal member is disposed within the contour of the contact surface of the second seal member facing the second seal member. Thereby, even if the first and second seal members are displaced relative to each other, the relative displacement can be absorbed by the dimensional difference, thereby preventing damage to the electrolyte membrane as much as possible, and ensuring a reliable fixing function and good performance. It is possible to ensure excellent sealing performance.

[Brief description of the drawings]

[Figure 1] to the engagement Ru fuel cell to the onset Akira seal structure is built
It is a schematic longitudinal cross-sectional explanatory drawing of the state which was set .

2 is an exploded perspective view showing main components of a prior carboxymethyl Lumpur structure.

Figure 3 is an enlarged longitudinal sectional view of a prior carboxymethyl Lumpur structure.

4 is a front view showing a prior carboxymethyl Lumpur structure.

FIG. 5 is a schematic longitudinal sectional view showing a state in which another seal structure is incorporated in a humidifier.

Figure 6 is an enlarged longitudinal sectional view of a prior carboxymethyl Lumpur structure.

FIG. 7 is an explanatory longitudinal sectional view of a seal structure according to a conventional technique.

──────────────────────────────────────────────────続 き Continuation of front page (72) Inventor Takafumi Okamoto 1-4-1 Chuo, Wako-shi, Saitama Pref. Honda Research Laboratory Co., Ltd. (56) References JP-A-8-180883 (JP, A) (58) Survey Field (Int.Cl. ⁷ , DB name) H01M 8 / 02,8 / 10

Claims (2)

(57) [Claims] A first and a second separator sandwiching a fuel cell structure comprising a solid polymer electrolyte membrane sandwiched between an anode electrode and a cathode electrode; comprising first and second sealing member opposed to being disposed, wherein the first and second separators are formed into a flat surface to the peripheral surface directly sandwiching the solid polymer electrolyte membrane, prior to Kia First and second seal grooves surrounding the node-side electrode and the cathode-side electrode and accommodating the first and second seal members, wherein the first and second seals are provided. The member has a rectangular cross section,
In addition, the width dimension of each planar contact surface portion is set to be different, and the entire contact surface portion of the first seal member is arranged within the contour shape of the contact surface portion of the second seal member opposed to the first seal member. Features fuel cell. 2. The first and second separators further include a first and a second electrode housing the anode electrode and the cathode electrode.
And a second concave portion.