JPH0963602A - Solid polymer electrolyte membrane fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make a solid polymer electrolyte membrane fuel cell have a simple structure and suitable to be miniaturized and reduce the ion conduction resistance of a solid polymer electrolyte membrane itself and electrode catalytic layers and the contact resistance of an electron conductor and an ion conductor of materials which compose a solid polymer electrolyte membrane type fuel cell. SOLUTION: A first separator 16 made of a porous body is fitted in a hole part 24 formed in a second separator 18 made of a dense material and a cooling chamber 25 is composed between the first separator 16 and a second separator 18. The first separator 16 is pushed toward a solid polymer electrolyte membrane side by pressure of water introduced into the cooling chamber 25. The solid polymer electrolyte membrane is damped and swollen and the inner resistance is lowered and at the same time the contact resistance upon ion conduction and the electron conduction between the solid polymer electrolyte membrane and the first and the second separators 16, 18 is also lowered.

Description

Detailed Description of the Invention

[0001]

TECHNICAL FIELD The present invention relates to a solid polymer electrolyte membrane fuel cell.

[0002]

2. Description of the Related Art A solid polymer electrolyte membrane fuel cell is constructed by joining electrodes containing a catalyst to both sides of a solid polymer electrolyte membrane. In such a configuration, the fuel gas mainly composed of hydrogen gas or the like is supplied to the anode electrode, and the oxidant gas mainly composed of oxygen gas or the like is supplied to the cathode side. Then, the catalyst in the anode electrode ionizes the hydrogen gas in the fuel gas, and the ions pass through the solid polymer electrolyte membrane and are sent to the cathode side opposite to the solid polymer electrolyte membrane. Since the water molecules are transferred along with the movement of the ions, the dry state progresses on the anode side. Particularly, as the current density increases and the amount of heat generated increases, the water content of the solid polymer electrolyte membrane becomes insufficient, the ionic conductivity decreases, and the output of the fuel cell decreases. As a countermeasure, the following method is adopted in the conventional fuel cell.

As a preferred example, an indirect humidification method has been proposed in which a humidification section is provided adjacent to the fuel cell and the humidification section humidifies the fuel gas supplied to the anode side. For example, in the technical idea disclosed in JP-A-6-231788, an ultrasonic vibrator is attached to the bottom surface of the humidifier, and the mist generated by the ultrasonic vibrator and the fuel gas supplied to the anode side are mixed. It is then humidified and supplied to the fuel cell body.

On the other hand, the prior art disclosed in Japanese Patent Laid-Open No. 6-124722 discloses that hydrogen, oxygen or air passes through pure water heated by an electric heater to humidify them. ing.

On the other hand, Japanese Unexamined Patent Publication No. 6-231793 discloses a direct humidification method employing a structure in which water is directly supplied to a solid polymer electrolyte membrane to humidify it. In this case, the gas separator element adjacent to the solid polymer electrolyte membrane is made of a porous material and the cooling water supply passage is defined in the gas separator element. Therefore, when cooling water is supplied to the cooling water supply passage, the cooling water permeates the gas separator element by the capillary phenomenon, reaches the solid polymer electrolyte membrane, and humidifies.

[0006]

By the way, in the direct humidification method disclosed in the above-mentioned JP-A-6-231793,
The oxidant gas may enter the cooling water supply passage from the oxidant electrode side of the gas separator. To solve this,
Even when the structure shown in FIG. 2 of JP-A-6-231793 is adopted so that the oxidant gas mixed in the cooling water does not reach the anode side, the cooling water is supplied to the anode side and the cathode side. Therefore, the structure becomes complicated, and the number of parts must be increased. Further, when the pressure of the oxidant gas side electrode is lowered, the cooling water in the gas separator is led out to the oxidant gas side, so that the amount of water in the oxidant gas side electrode exceeds the reaction product water, and as a result, There is an inconvenience that the gas flow path is blocked.

On the other hand, in the prior art relating to the above indirect humidification method, since the humidification mechanism is located at a position distant from the fuel cell main body, moisture is condensed in the pipe connecting the fuel cell main body and the humidification mechanism. However, it is difficult to send the fuel gas having the desired humidity to the fuel cell main body. Moreover, since the humidifying mechanism is separate from the fuel cell body, it cannot be made compact as a whole. Further, in this type of device, it is difficult to supply water corresponding to the load fluctuation of the fuel cell main body, and there are disadvantages that the energy efficiency deteriorates because the heating and heat retaining portions increase.

The present invention has been made in order to solve this kind of problem, and has a simple structure, is suitable for miniaturization, has high responsiveness, and is excellent in energy efficiency. Provided is a solid polymer electrolyte membrane fuel cell, which can reduce the ionic conductivity resistance of the solid polymer electrolyte membrane itself by uniformly moisturizing and can also reduce the contact resistance with a current collector. The purpose is to

[0009]

In order to solve the above-mentioned problems, the present invention relates to a solid polymer electrolyte membrane in which first and second electrode catalyst layers are in contact with or integrally formed on both side surfaces. A first separator formed of a porous body provided on the side of the first electrode catalyst layer and the first separator movably or deformably held, and together with one surface of the first separator A second separator, which has a dense structure defining a cooling chamber therein and faces the second electrode catalyst layer, and a conductive seal member provided between the first and second separators are provided. A plurality of ribs for defining a fuel gas supply passage on the other surface of the first separator, and a plurality of ribs for defining an oxidant gas supply passage on one surface of the second separator. And a plurality of refills for the first separator. The tip contact with the first electrode catalyst layer, tips of the plurality of ribs of the second separator is characterized in that abuts against the second electrode catalyst layer.

With the above configuration, the first
Fuel gas is supplied from a passage defined by a plurality of ribs on the other surface side of the separator, and the fuel gas reaches the solid polymer electrolyte membrane from the first electrode catalyst layer. On the other hand, the second
The oxidant gas is supplied from a passage defined by a plurality of ribs on one surface of the separator, and the oxidant gas (air) is supplied.
Reaches the second electrode catalyst layer and is diffused. During this time, the water supplied from the cooling chamber reaches the first separator made of a porous body, swells the porous body and permeates from the first separator, and the first electrode catalyst layer as an anode electrode. Reach and moisten it.

In this case, the porous body forming the first separator is made of carbon material, conductive porous sintered metal, porous conductive rubber, or porous conductive resin, and any combination thereof. If so, the first separator can be easily wetted, and the electrode catalyst layer on the anode side can be prevented from being dried more than necessary. In particular, when the porosity of the porous body is 70% or less and the pore diameter is 40 μm or less, the wetting action is more suitably performed.

Further, the present invention provides a solid polymer electrolyte membrane, a fuel gas side electrode which contacts one surface of the solid polymer electrolyte membrane, and an oxidant which contacts the other surface of the solid polymer electrolyte membrane. A gas side electrode, a first separator disposed in the vicinity of the fuel gas side electrode and displacing to the solid polymer electrolyte membrane side, and disposed in the vicinity of the oxidant gas side electrode and A second separator that is displaced toward the solid polymer electrolyte membrane side, and the fuel gas side electrode is formed by stacking a fuel gas side electrode catalyst layer and a fuel gas diffusion layer, and the oxidant gas side. The electrode is characterized by being constituted by laminating an oxidant gas side electrode catalyst and an oxidant gas diffusion layer.

As described above, the fuel gas side electrode is formed by laminating the fuel gas side electrode catalyst layer and the fuel gas diffusion layer, while being separated from the solid polymer electrolyte membrane.
Since the fuel gas side electrode is pressed against the solid polymer electrolyte membrane, the manufacturing process is further simplified and facilitated when manufacturing the thin film electrode. The same applies to the oxidant gas side electrode.

If the fuel gas diffusion layer and the oxidant gas diffusion layer are made of carbon paper, the fuel gas and the oxidant gas can be diffused smoothly and can be manufactured at low cost.

In the present invention, the water supply direction is opposed to the fuel gas and oxidant gas supply directions.
Therefore, the fuel gas and the oxidant gas flowing from above are effectively cooled by the low-temperature water rising from below as they approach downward, whereby the first and second separators, the fuel gas side electrode, and It is possible to effectively cool the oxidant gas side electrode and suppress the heat generation of the entire fuel cell. Furthermore, since the temperature distribution can be made uniform, a good power generation effect can be achieved.

[0016]

Preferred embodiments of the solid polymer electrolyte membrane fuel cell according to the present invention will be described in detail below with reference to the accompanying drawings.

The fuel cell stack 10 is shown in FIGS.
As shown in, basically, the power generation unit 12 and the separator unit 1
And 4. The separator portion 14 includes a first separator 16 made of a porous body and a second separator 18 having a relatively thick and dense structure. The first separator 16 is a porous body having a porosity of 7
It is made of a carbon material having 0% or less and a pore diameter of 40 μm or less. As can be easily understood from the drawing, a plurality of ribs 20 are provided in parallel in the lateral direction on the rectangular first separator 16, and a passage 22 for supplying a fuel gas is defined between the adjacent ribs 20 and 20. Is made. On the other hand, as shown in FIG. 4, the second separator 18 has a substantially C-shaped cross section, and a hole 24 into which the first separator 16 is fitted is defined on one side surface side. Communicate with a cooling chamber 25 defined in the second separator 18. This second separator 18
On the other side surface, a plurality of ribs 26 are provided in parallel with each other in the vertical direction, and thereby a passage 28 for supplying an oxidant gas, for example, air, is defined between the adjacent ribs 26, 26 ( 2 and 3).

Further, the second separator 18 will be described. As is clear from FIGS.
The left frame 18 a of the separator 18 has a rectangular parallelepiped through hole 34.
Is defined, and another through hole 36 is defined in the right frame 18b. A plurality of pores 38 communicating from the through hole 34 to the hole portion 24 are defined in the left frame 18a, while a plurality of pores 40 communicating from the through hole 36 to the hole portion 24 are defined in the right frame 18b. Well defined (see Figure 1). Therefore, the first separator 16 is inserted into the hole 24 of the second separator 18.
When is fitted, the pores 38 and the pores 40 communicate with each other through the passage 22 of the first separator 16. In addition, as easily understood from FIG. 4, the first separator 1
When 6 is fitted in the hole 24 of the second separator 18, a seal member 30 such as conductive rubber or conductive resin is attached between the first separator 16 and the second separator 18.

On the other hand, the upper frame 18c of the second separator 18
A rectangular parallelepiped through hole 42 is defined in the lower frame 18.
Another through hole 44 is defined in d. The upper frame 18
In c, a plurality of pores 4 communicating from the through hole 42 to the passage 28 are provided.
6 are defined, while a plurality of pores 48 communicating with the passage 28 from the through hole 44 are defined in the lower frame 18d. Therefore, the plurality of pores 46 and the plurality of pores 48 are in communication with each other through the passage 28.

The upper frame 18c of the second separator 18 and the left frame 1
A communication hole 50 is defined in the corner formed by 8a, and a communication hole 52 is defined in the corner formed by the lower frame 18d and the right frame 18b. The communication holes 50 and 5
2 is connected to the cooling chamber 25 defined by fitting the first separator 16 into the hole 24 of the second separator 18 in an oblique direction (see FIG. 4).

Next, the power generation section 12 will be described. The power generation unit 12 includes a solid polymer electrolyte membrane 60, and a first electrode catalyst layer 62a and a second electrode catalyst layer 62b provided on both sides of the solid polymer electrolyte membrane 60. The first and second electrode catalyst layers 62a, 62
The size of b is substantially the same as the inner edge of the second separator 18 defining the hole 24.

FIG. 5 shows the structure of the gasket 66. The gasket 68 has substantially the same shape as the gasket 66. Therefore, the gaskets 66 and 68 are sandwiched between the second separator 18 and the solid polymer electrolyte membrane 60, as shown in FIG. The gasket 66, 6
As will be described later, the through holes 70, 72 are provided in the passage 8 so that the fuel gas and the oxidant gas can flow between the plurality of first separators 16 and the second separators 18 stacked as the fuel cell stack 10. , 74, 76, communication holes 78, 80
And a large hole 82 is defined. Therefore, the power generation unit 12
And the separator portion 14 are assembled, the through hole 34 of the second separator 18 and the through hole 7 of the gaskets 66, 68
0 communicates with each other, the through hole 36 and the through hole 72 communicate with each other, the through hole 42 and the through hole 74 communicate with each other, and the through hole 44 and the through hole 76 communicate with each other. The plurality of ribs 20 of the first separator 16 enter the large holes 82.

The power generation section 12 and the separator section 14 configured as described above are combined as follows. That is, the first separator 1 is placed in the hole 24 of the second separator 18.
6, the seal member 30 seals and electrically connects the first separator 16 and the second separator 18.
The gasket 66 is on the first separator 16 side and is joined to the second separator 18, and the gasket 68 is joined to the rib 26 side surface of the second separator 18. The power generation unit 12 is interposed between the gasket 66 and the gasket 68. In addition,
At the time of stacking and fixing them, as shown in FIG. 6, the pipe joints 79, 81, 84, 8 communicating with the through holes 34, 36, 42, 44 of the second separator 18 and the communicating holes 50, 52.
6, end plates 92 having pipe joints 88, 90 communicating with the communication holes 50, 52, and end plates 94 not having pipe joints are arranged at both ends thereof, and the four corners thereof are tightened by tightening bolts 96a to 96d. Constructed by tightening firmly and evenly.

The details of the end plate 94 are shown in FIG.
The end plate 94 is a flat plate body having substantially the same size as the end plate 92. The tightening bolts 96a to 96 are provided at the four corners of the end plate 94.
Tightening holes 112a to 112d into which one end of d is inserted.
Is defined.

The fuel cell stack 1 having the above structure
As shown in FIG. 8, the pipe joint 90 is provided with an external circuit for supplying water, which is a refrigerant, such as water. That is, the tank 120 that stores the circulating water,
A pressure increasing pump 122 for increasing the pressure of the refrigerant to a predetermined pressure, and an ion exchange resin 124 are connected to a pipe joint 90 of an end plate 92 of the fuel cell stack 10 via a pipe 126. On the other hand, the pipe joint 88 of the end plate 92 is connected to the back pressure valve 130 and the tank 1 via the pipe 128.
It is connected to 20.

Next, the operation of the solid polymer electrolyte membrane fuel cell according to the present invention will be described. Fuel cell stack 1
6, the fuel gas is supplied from a fuel gas supply source (not shown) to the pipe joint 8 of the end plate 92 as shown in FIG.
1, through the through hole 72 of the gasket 66 (68), the through hole 36 of the second separator 18, and the pore 40, the oxidant gas is supplied from the oxidant gas supply source (not shown) to the passage 22 of the first separator 16. Pipe joint 8 of end plate 92
4, is supplied to the passage 28 through the passage 74 of the gasket 66 (68), the second separator 18, the through hole 42, and the pore 46.

At the same time, water serving as cooling water reaches the communication hole 52 from the pipe joint 90 of the end plate 92, reaches the cooling chamber 25, and raises the internal pressure of the cooling chamber 25. At this time, the pressure of the water (PH ₂ O) is equal to the pressure of the fuel gas (P
Since it is set higher than H ₂ ), the water permeates into the first separator 16 formed of water-permeable thin plate-like porous carbon and displaces or deforms it toward the electrode catalyst layer 62a side. At the same time, the fuel gas flowing in the passage 22 defined by the first separator 16 is finally humidified. The humidified fuel gas is used in the electrode catalyst layer 62.
After reaching a, the solid polymer electrolyte membrane 60 is humidified. Therefore, the ribs 20 of the first separator 16 are evenly pressed against the electrode catalyst layer 62a by the displacement action or the deformation action, and thus press the solid polymer electrolyte membrane 60 against the second separator 18. Moreover, the solid polymer electrolyte membrane 60 is maintained at an appropriate humidity, and ionic conductivity resistance and contact resistance do not increase. On the other hand, passage 22
The unreacted fuel gas among the fuel gas supplied to the through hole 34 of the second separator 18 immediately before the end plate 94.
Then, the gas passes through the through hole 70 and the like of the gasket 66 and is discharged from the pipe joint 79. Similarly, a part of the oxidant gas reaches the through hole 44 of the second separator 18, and the pipe joint 86
Emitted from.

Further, when the operation of the fuel cell stack 10 is finished and the booster pump 122 is stopped and the throttle of the back pressure valve 130 is opened, the water in the cooling chamber 25 passes through the communication hole 50 of the second separator 18 and ends. It is discharged from the pipe joint 88 of the plate 92 to the outside, and the internal pressure of the cooling chamber 25 decreases. Therefore, the surface pressure on the side of the first separator 16 also decreases and returns to the pressure at the time of assembly.

As described above, according to the solid polymer electrolyte membrane fuel cell of the present embodiment, the water introduced into the cooling chamber 25 defined by the first separator 16 and the second separator 18 is water. It is supplied to the power generation unit 12 through the first separator 16 which is a permeable porous body, and further the hydraulic pressure increases the pressing force to the solid polymer electrolyte membrane 60 under the displacement or deformation of the first separator 16. The electrode catalyst layer 62a is kept at an appropriate humidity, and ionic conductivity resistance and contact resistance are not increased. Moreover, since the water supplied to the cooling chamber 25 provided in the separator portion 14 is directly supplied through the first separator 16 made of porous carbon, it is not necessary to provide a new humidifying means.

Further, the first and second separators 16 and 18
Since water is supplied from the cooling chamber 25 defined by, the water is evenly supplied to the electrode catalyst layer 62a.

Further, the amount of water supplied is increased or decreased according to the dry state of the power generation section 12, but at this time, since water is supplied directly from the cooling chamber 25 of each fuel cell stack 10, the response is high. .

Further, hydrogen gas (P
H ₂ ) and oxygen gas (PO ₂ ) which is an oxidant gas, the water pressure (PH ₂ O) is set to be higher, and
Since the second separator 18 is made of a dense material,
Only by infiltration of water into the passage 22 of the separator 16, it is possible to reliably prevent the fuel gas and the oxidant gas from mixing in the cooling chamber 25, thus ensuring safety.

Next, another embodiment of the present invention will be shown. In the above-described embodiment, the power generation unit 12 is integrally provided with the first electrode catalyst layer 62a and the second electrode catalyst layer 62b with the solid polymer electrolyte membrane 60 interposed therebetween. And a porous body,
That is, the first separator 16 made of a carbon material is in contact with the first electrode catalyst layer 62a. However, in this new embodiment, rather, the fuel gas side electrode is prepared separately from the solid polymer electrolyte membrane,
On the other hand, the oxidant side electrode is arranged on the opposite side of the solid polymer electrolyte membrane.

That is, the solid polymer electrolyte membrane 200 is
It is configured separately from the fuel gas side electrode 202, and similarly is configured separately from the oxidant gas side electrode 204. The fuel gas side electrode 202 is composed of an electrode catalyst layer 206 and a gas diffusion layer 208 made of carbon paper, and both are integrally formed in advance. On the other hand, the oxidant gas side electrode 204 is composed of an electrode catalyst layer 210 and a gas diffusion layer 212 made of carbon paper. The oxidant gas side electrode catalyst layer 210 and the gas diffusion layer 212 are the fuel gas side electrode. Similar to 202, it is integrally configured in advance. Therefore, by integrating the electrode catalyst layer and the gas diffusion layer, which are generally extremely thin films, in advance, the first electrode catalyst layer 62a on the solid polymer electrolyte membrane 60,
The second electrode catalyst layer 62b has the advantage of being easier to manufacture and easier to maintain and maintain than providing the second electrode catalyst layer 62b. In this case, instead of the above configuration, the solid polymer electrolyte membrane 200,
The fuel gas side electrode 202 and the oxidant gas side electrode 204 are separately prepared, and before the fuel cell is assembled as a whole, the solid polymer electrolyte membrane 200, the fuel gas side electrode 202, and the oxidant gas side electrode 204 are It is also possible to form the power generation unit by integrally assembling with a hot press or the like.

FIG. 10 shows a structure in which the power generation section thus constructed is assembled as a fuel cell mainly using a separator, a gasket and the like.

First, the fuel gas side electrode 202 so that one end face of the solid polymer electrolyte membrane 200 is in contact with the peripheral edge of the solid polymer electrolyte membrane 200.
A gasket 214 is arranged on the side. This gasket 21
4, a hole 216 for fitting the fuel gas side electrode 202 with a slight gap is formed. The other end surface of the gasket 214 contacts the end surface of the separator 218 having an inverted U-shaped cross section in the drawing. The separator 218 is made of a dense material such as carbon or stainless steel, and has a porous fuel gas guide member 2 inside.
20 and a water guide member 222. Separator 218
Has water guide channels 224a and 224b therein. On the other hand, the fuel gas guide member 220 is provided with a plurality of gas guide passages 226 for passing the fuel gas,
Similarly, the water guiding member 222 also has a water guiding channel 224.
A water guide channel 228 is provided for allowing water to flow down from one side to the other side.

Fuel gas guide member 220 and water guide member 22
2 is joined to the separator 218 with a conductive material 229 such as a conductive rubber or a conductive resin. Therefore, the water guided from the water guide passage 228 is prevented from directly flowing into the gas guide passage 226.

In this case, it is preferable that the water guide passage 228 flows from the bottom to the top, while the fuel gas introduced into the gas guide passage 226 flows from the top to the bottom so as to face each other. When the fuel gas flows from top to bottom, the water guide member 22 that permeates the porous fuel gas guide member 220.
The water from 2 gradually humidifies the fuel gas during power generation. By cooling the humidified fuel gas with low-temperature water that rises from the bottom to the top, it becomes possible to make the temperature distribution of the power generation unit uniform.

An insulating member 230 is interposed on the surface of the separator 218 opposite to the gasket 214, and the insulating member 230 contacts the end plate 240. The end plate 240 is provided with a fuel gas supply / exhaust port, a cooling water inlet / outlet port, and an oxidant gas inlet / outlet port (not shown) having the same shapes as those in the above-described embodiment.

A gasket 250 having substantially the same shape as the gasket 214 is provided on the side opposite to the fuel gas side electrode 202. This gasket 250 is a gasket 214
Similarly, the oxidant gas side electrode 204 in which the oxidant gas side electrode catalyst layer 210 and the gas diffusion layer 212 are integrated is received with a slight gap. Therefore, the gasket 250 is provided with a hole 252 having a large opening like the hole 216 of the gasket 214.

A separator 254 is provided which is in contact with one end surface of the gasket 250 and receives a part of the oxidant gas side electrode 204. This separator 254 is
It is roughly divided into an oxidant gas side separator 256 and a fuel gas side separator 258. An O-ring 260 is provided between the oxidant gas side separator 256 and the fuel gas side separator 258, and liquid-tightly shields both the separators 256 and 258 from each other.

An oxidant gas guide member 262 is provided on the oxidant gas side separator 256. In the oxidant gas guide member 262, a plurality of oxidant gas guide passages 264 for guiding the oxidant gas extend in parallel and vertically to each other. On the other hand, similar to the separator 218, the fuel gas side separator 258 is provided with a plurality of gas guide channels 266 extending in the vertical direction.
8 are provided. A water guide member 272 is provided between the oxidant gas side separator 256 and the fuel gas side separator 258 in the vertical direction and has a plurality of water guide channels 270. In fact, the water guide member 272 is vertically divided into two parts. In this case, the oxidant gas side separator 256, the fuel gas side separator 258, the oxidant gas guide member 262, the fuel gas guide member 268, and the water guide member 272 are joined by a particularly conductive member. At the time of this joining, preferably, a conductive material 273 made of conductive rubber or conductive resin is used.

In this way, the solid polymer electrolyte membrane 200, the fuel gas side electrode 202, the oxidant gas side electrode 204, the separator 218, the separator 254, etc. are laminated, as shown in FIG.
The solid polymer electrolyte membrane fuel cell shown in 1 is constructed.
In this embodiment, detailed description of the flow paths of the fuel gas, the oxidant gas, and the water is omitted, but it will be easily understood by those skilled in the art.

The operation of the solid polymer electrolyte membrane fuel cell configured as described above will be described. The fuel gas is made to flow vertically downward from the gas guide passage 226, while the water guide member 222 is provided. Water is supplied upward from the water guide flow path 228 in the vertical direction. Similarly, in the oxidant gas side separator 256, oxidant gas is supplied from above to the oxidant gas guide flow path 264 of the oxidant gas guide member 262, and the oxidant gas is supplied from above in the vertical direction to face water. Water is supplied from the guide flow path 270. Therefore, the fuel gas guide member 220 and the oxidant gas guide member 26
2 and the two are wetted together.

Therefore, the fuel gas introduced from the gas guide flow path 226 presses the fuel gas side electrode 202 with its pressure to press itself against the solid polymer electrolyte membrane 200.
Similarly, the other surface of the solid polymer electrolyte membrane 200 is filled with the oxidant gas introduced into the oxidant gas guide channel 264, and the oxidant gas side electrode 204 is attached to the solid polymer electrolyte membrane 200. To press.

Here, the same power generation action as that of the above-described embodiment is performed.

As described above, according to this embodiment,
Since the solid polymer electrolyte membrane 200 is separated from the fuel gas side electrode 202 and the oxidant gas side electrode 204, the solid polymer electrolyte membrane 200 can be manufactured very easily and in large quantities. Therefore, it is possible to achieve a reduction in the price of the fuel cell as a whole and to assemble the fuel cell more easily, and to easily maintain the fuel cell.

FIG. 12 shows another embodiment of the present invention. In this embodiment, in particular, the water guide member 272
The groove-shaped water guide passage 270 is not provided. Rather, it is composed of a rectangular parallelepiped or rectangular frame 300,
A large volume space 302 having a large opening in its central portion is formed, and a water guide member 304 is configured as a whole. Both side surfaces of the frame 300 are closed by surface pressure generating plates 306a and 306b made of a porous member such as porous carbon. At that time, conductive rubber or conductive resin 3
08a and 308b seal the boundary between the oxidant gas guide member 262 and the fuel gas guide member 268.

In such a structure, when the water is made to flow from the bottom to the top in the direction orthogonal to the drawing, the space 302 is filled with the water, so that the surface pressure generating plates 306a, 306b.
Are bent in a direction away from each other, and the oxidant gas guide member 2
62 and the fuel gas guide member 268 are pressed and an appropriate amount of water is supplied to them to humidify them. The other fuel gas guide member 268 and the water guide member 22 on the oxidant gas guide member 262 side.
It is needless to say that the configuration of the water guide member 222 and the like can be simplified by similarly using the surface pressure generating plates 306a and 306b for the second and the like.

FIG. 13 shows still another embodiment of the present invention. In this embodiment, an oxidant gas guide pressing plate 350a in which the surface pressure generating plate 306a and the oxidant gas guide member 262 shown in FIG. 12 are integrated, and a surface pressure generating plate 306b.
And a fuel gas guide member 268 are integrated into a fuel gas guide pressing plate 350b. Conductive rubber or conductive resin 352a, 352b is embedded around the oxidant gas guide pressing plate 350a and the fuel gas guide pressing plate 250b.

With this structure, different surface pressure generating plates 306a, 306 are provided as in the embodiment of FIG.
Since it is not necessary to provide b, the number of parts can be reduced and the assembling can be facilitated.

14 and 15 show another embodiment of the present invention. In this embodiment, unlike the embodiment shown in FIG. 12, the water outlet 4 is provided at a substantially central portion of the surface pressure generating plate 400.
02, and the water outlet 402 communicates with a small hole 406 provided in the fuel gas guide member 404. The flat surface 408 of the fuel gas guide member 404 evenly abuts the gas diffusion layer made of carbon paper of the power generation section, and the abutting surface is provided with a plurality of radial grooves 410 as shown in FIG. It is set up. The periphery of the fuel gas guide member 404 is composed of a dense member 412.

According to this structure, water can be directly supplied to the power generation section, and a quick start-up as a battery and sufficient water supply can be achieved.

FIG. 16 is a modification of FIG. Sealing members 450 and 452 are arranged outside the oxidant gas guide member 262 and the fuel gas guide member 268.

[0055]

According to the solid polymer electrolyte membrane fuel cell of the present invention, the following effects can be obtained.

That is, since the first separator forming the cooling chamber is made of a water-permeable material, preferably porous carbon, the water supplied to the cooling chamber is made of porous carbon. Water is uniformly supplied from the first separator to the solid polymer electrolyte membrane through the electrodes, and the pressing force increases due to the displacement action or the deformation action caused by the supplied water pressure. Since the solid polymer electrolyte membrane is humidified by using the cooling water in this manner, it is not necessary to provide a mechanism for humidification, and the entire structure can be compactly formed. The solid polymer electrolyte membrane of each unit battery can be uniformly moisturized. Therefore, not only the electric resistance in the solid polymer electrolyte membrane can be reduced in combination with the uniform pressing force, but also the contact resistance related to ionic conduction and electronic conduction can be suppressed low,
It is also energy efficient.

Moreover, the solid polymer electrolyte membrane, the fuel gas side electrode, and the oxidant gas side electrode are separated from each other, and the electrode itself is separated from the electrode catalyst layer and the gas diffusion layer. Therefore, the peculiar effect that the manufacturing of the power generation unit is facilitated, the product can be provided at a low price, and the maintenance is easy is obtained.

Further, in the present invention, by using thin carbon paper as the gas diffusion layer, gas permeability is improved, and as a result, power generation performance is further improved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of essential parts of a solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 2 is a perspective view of a second separator of the solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 3 is a fragmentary perspective view showing a second separator of the solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 4 is an exploded view of a solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 5 is a perspective view of a gasket constituting a solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 6 is an explanatory view of a stack state of the solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 7 is a perspective view of an end plate constituting a solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 8 is an explanatory diagram of a cooling water supply circuit of a solid polymer electrolyte membrane fuel cell according to the present invention.

FIG. 9 is a cross-sectional view showing a state in which a solid polymer electrolyte membrane in another embodiment of a solid polymer electrolyte membrane fuel cell according to the present invention, a fuel gas side electrode and an oxidant gas side electrode are separated and configured. It is a side view.

FIG. 10 is a partially omitted exploded cross-sectional view of the structure of integrally assembling the power generation part with the separator, the gasket and the like in another embodiment of the solid polymer electrolyte membrane fuel cell according to the present invention shown in FIG. .

FIG. 11 is a partially omitted horizontal cross-sectional view of a state in which a fuel cell is configured by sandwiching the power generation unit and the like shown in FIG. 10 with end plates.

FIG. 12 is a partially omitted vertical cross-sectional view of a solid polymer electrolyte membrane fuel cell using a surface pressure generating plate according to still another embodiment of the present invention.

FIG. 13 is a partially omitted vertical sectional view in which a surface pressure generating plate and a gas guide member according to still another embodiment of the present invention are also used, and a conductive member is arranged around the same.

FIG. 14 is a schematic vertical cross-sectional view of a solid polymer electrolyte membrane according to still another embodiment of the present invention.

FIG. 15 is a view taken along line XV-XV in FIG.

FIG. 16 is a schematic vertical sectional view of a solid polymer electrolyte membrane according to still another embodiment of the present invention.

[Explanation of symbols]

10 ... Fuel cell stack 16 ... 1st ... Separator 18 ... 2nd separator 20, 26 ... Rib 30 ... Sealing member 60 ... Solid polymer electrolyte membrane 62a ... 1st electrode catalyst layer 62b ... 2nd electrode catalyst layer 66, 68 ... Gasket 200 ... Solid polymer electrolyte membrane 202 ... Fuel gas side electrode 204 ... Oxidant gas side electrode 218, 256, 258 ... Separator

 ─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Akio Yamamoto 1-4-1 Chuo, Wako-shi, Saitama Honda R & D Co., Ltd. (72) Inventor Ichiro Tanaka 1-4-1 Chuo, Wako-shi, Saitama Co., Ltd. Honda R & D Laboratory

Claims (12)

[Claims] 1. A solid polymer electrolyte membrane in which first and second electrode catalyst layers are in contact with or integrally formed on both side surfaces, and a porous body provided on the first electrode catalyst layer side. A formed first separator; and a second separator that holds the first separator in a displaceable or deformable manner and that has a dense interior that defines a cooling chamber inside with one surface of the first separator. A second separator facing the electrode catalyst layer, and a conductive seal member provided between the first and second separators, and a fuel gas supply passage is defined on the other surface of the first separator. And a plurality of ribs for defining an oxidant gas supply passage are provided on one surface of the second separator, and the tips of the plurality of ribs of the first separator have the first ribs. The second separator is abutted on the electrode catalyst layer. The solid polymer electrolyte membrane fuel cell is characterized in that tips of a plurality of ribs of the lator are in contact with the second electrode catalyst layer. 2. The fuel cell according to claim 1, wherein the porous body forming the first separator is a carbon material, a conductive porous sintered metal, a porous conductive rubber, or a porous conductive resin. , And a solid polymer electrolyte membrane fuel cell comprising any combination thereof. 3. The solid polymer electrolyte membrane according to claim 2, wherein the porous material forming the first separator has a porosity of 70% or less and a pore diameter of 40 μm or less. Type fuel cell. 4. A solid polymer electrolyte membrane, a fuel gas side electrode contacting one surface of the solid polymer electrolyte membrane, and an oxidant gas side electrode contacting the other surface of the solid polymer electrolyte membrane. A first separator disposed in proximity to the fuel gas side electrode and displaced to the solid polymer electrolyte membrane side; and a solid polymer electrolyte disposed in proximity to the oxidant gas side electrode A second separator for displacing to the membrane side, the fuel gas side electrode is formed by stacking a fuel gas side electrode catalyst layer and a fuel gas diffusion layer, and the oxidant gas side electrode is an oxidizer. A solid polymer electrolyte membrane fuel cell comprising a gas-side electrode catalyst and an oxidant gas diffusion layer stacked together. 5. The solid polymer electrolyte membrane fuel cell according to claim 4, wherein the fuel gas diffusion layer forming the fuel gas side electrode is made of carbon paper. 6. The solid polymer electrolyte membrane fuel cell according to claim 4, wherein the oxidant gas diffusion layer forming the oxidant gas side electrode is made of carbon paper. 7. The fuel cell according to any one of claims 4 to 6, wherein the first separator has a fuel gas supply passage extending vertically inside thereof and a water supply passage. And a fuel gas diffusion layer forming the fuel gas side electrode facing the fuel gas supply channel. 8. The solid fuel cell according to claim 7, wherein the fuel gas flowing through the fuel gas supply passage and the water flowing through the water supply passage flow in directions perpendicular to and opposite to each other. Polymer electrolyte membrane fuel cell. 9. The fuel cell according to claim 4, wherein the second separator has an oxidant gas supply channel extending vertically inside and a water supply channel. And a oxidant gas diffusion layer that constitutes the oxidant gas side electrode faces the oxidant gas supply channel. 10. The fuel cell according to claim 4, wherein the oxidant gas flowing through the oxidant gas supply passage and the water flowing through the water supply passage are perpendicular to each other, and A solid polymer electrolyte membrane fuel cell characterized by flowing in opposite directions. 11. The fuel cell according to claim 4, wherein the first and second separators are a carbon material, a conductive porous sintered metal, and a porous conductive rubber, respectively. , Or a porous conductive resin and any combination thereof, a solid polymer electrolyte membrane fuel cell. 12. The fuel cell according to claim 11, wherein the porous body forming the first separator has a porosity of 70.
% And the pore diameter is 40 μm or less, a solid polymer electrolyte membrane fuel cell.