JP3530339B2 - Polymer electrolyte fuel cell and method of manufacturing the same - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a polymer electrolyte fuel cell, and to a technique for improving gas sealing performance.

[0002]

2. Description of the Related Art An example of a polymer electrolyte fuel cell 400 is shown in FIG. As shown in the figure, a cell 410 in which an anode 412 and a cathode 413 (in the figure, the back surface of the solid polymer film 11 is not visible) are arranged in the central portion of the solid polymer film 411, and a cell 410 A pair of ribbed separator plates 420 and 430 that sandwich 410, and an anode 412.
The separator plate 420, so as to contact the cathode 413,
A pair of current collectors 4 inserted between 430 and the cell 410
40 and 441, and sealing members 450 and 460 for sealing this portion interposed between the outer periphery of the separator plates 420 and 430 and the cell 410, are laminated, and the separators 420 and 430 have the same structure. Each gas is supplied to generate electric power.

In the above solid polymer fuel cell,
The outer periphery is sealed to prevent the supplied hydrogen gas and air from leaking. That is, as shown in FIG. 9, the peripheral edge portion of the main surface of the solid polymer film 411 is brought into pressure contact with the seal members 450 and 460 to realize a gas seal structure having an excellent gas sealing property.

However, in the gas seal structure, when the solid polymer membrane is simply pressed against the seal members 450 and 460 from above and below, when the tightening force is gradually reduced as the battery is operated, the seal member and the solid member are separated from each other. There is a problem that the gas sealing property is also deteriorated due to the dislocation of the molecular film. On the other hand, JP-A-5-283093
In the publication, as shown in FIG. 10 (a), a solid polymer film 5 is used.
The electrodes 502 and 503 are opposed to the central part of 01, and further, the frame-shaped rubber sheets 504 and 505 which are sealing members around the electrodes 502 and 503 are inscribed in the inner peripheral part of the electrode outer peripheral part (see FIG. 10). By thermocompressing the laminated body arranged as shown in (b)) to obtain a structure 510 in which a rubber sheet is pressure-bonded to a solid polymer film, and alternately stacking the structure 510 with separators 520 and 530. By
A polymer electrolyte fuel cell is disclosed which has overcome the above-mentioned problems such as deterioration in gas sealing performance.

[0005]

In the polymer electrolyte fuel cell, if there is a gap between the outer periphery of the electrode and the inner periphery of the seal member, the solid polymer membrane will be formed due to the differential pressure of the reaction gas. It may become loose or damaged. Even in the fuel cell of the above publication, in order to prevent such damage to the membrane, the inner circumference of the seal member and the outer circumference of the electrode must be precisely aligned with each other, but it is considered to be actually difficult to manufacture. .

Moreover, the strength of the peripheral portion of the solid polymer membrane is reduced due to the tension generated by the expansion and contraction of the solid polymer membrane. If this decrease in strength progresses, the solid polymer film itself may be damaged in the worst case. Therefore, the present invention has been made in view of the above problems, and at least the hydrogen gas sealing performance is improved.
The present invention has been made for the purpose of providing the polymer electrolyte fuel cell described above and a simple manufacturing method thereof.

[0007]

According to the present invention , an anode is provided substantially at the center of one surface of a solid polymer membrane, a cathode is provided on the other surface of the solid polymer membrane so as to face the anode, and the anode is covered by covering the anode. A cathode-side current collector is provided to cover the cathode, and a cathode-side separator for supplying hydrogen gas and a cathode-side separator for supplying air, which are larger than the anode and the cathode and cover both current collectors. The cathode side current collector is provided with a size larger than that of the cathode, and the outer periphery of the cathode side current collector is joined to and integrated with the outer periphery of the solid polymer film.
Between the solid polymer film and the anode-side separator, a sealing member that covers the end face of the anode and the end face of the anode-side current collector is provided on the solid polymer film and the anode side.
Separator, the anode end face and the anode side current collector
It is characterized by being joined to the body and integrated .

As a result, by joining the peripheral portion of the solid polymer film, which is apt to decrease in strength, to the current collector,
It has a structure that reinforces the strength of the peripheral portion of the membrane. Therefore, it is possible to reliably prevent the membrane from being damaged due to the gas pressure difference and the expansion and contraction of the membrane itself , and at least to the hydrogen gas.
On the other hand, a reliable gas seal can be achieved. Moreover, according to such a configuration, the gap around the electrodes can be eliminated without strict size matching, so that the gas seal structure can be easily manufactured.

Further , according to the present invention, an anode is provided substantially at the center of one surface of the solid polymer film, a cathode is provided on the other surface of the solid polymer film so as to face the anode, and an anode side current collector is provided so as to cover the anode. the cathode covers provided on the cathode side collector, the greater than said anode and cathode covers both current collector, provided with a cathode side separator of the anode separator and the air supply for the hydrogen gas supply, the anode
A first sealing member is provided to cover the peripheral portion of the current collector on the card side.
Only the magnitude of the anode-side current collector are larger than the anode, around the anode side of the solid polymer membrane
A surface of the first seal member and a surface of the current collector.
Integrally joined to the periphery toward one side, the cathode side the cathode side separator and the peripheral surface of the solid polymer membrane
A second sealing member that covers the end surface of the cathode and the end surface of the cathode side current collector is provided between the peripheral surface and the solid surface.
Peripheral surface of the polymer membrane on the cathode side and the second seal member
It is characterized by joining and integrating . Since the seal member is fitted in the peripheral portion of the current collector on the anode side ,
The gas sealing performance of hydrogen gas becomes reliable.

The present invention also provides a step of providing an anode on the substantially central portion of one surface of the solid polymer film, a cathode on the other surface of the solid polymer film so as to face the anode, and an anode side current collector covering the anode. And a step of providing a cathode side current collector covering the cathode, and an anode side separator for supplying hydrogen gas and a cathode side separator for supplying air which are larger than the anode and the cathode and cover both current collectors. And a step of making the size of the cathode-side current collector larger than that of the cathode so that the outer periphery of the cathode-side current collector is joined by fusion bonding to the outer periphery of the solid polymer film. , between the polymer film and the anode side separator, the steps of: providing a sealing member covering the end face of the anode-side current collector and the anode of the end face Wherein the peripheral portion of the polymer film sheet
And a step of directly fusion-bonding with the roll member . Further, a step of providing an anode on substantially the center of one surface of the solid polymer film and a cathode on the other surface facing the anode, and covering the anode with an anode side current collector and covering the cathode. providing at cathode current collector, comprising the steps of: providing a cathode side separator of the larger than the anode and cathode covers both current collector, the anode-side separator and the air supply for the hydrogen gas supply, the anode side Cap the periphery of the current collector
Wearing the first sealing member, and increasing the size of the anode side current collector to be larger than the anode ,
The peripheral portion of the solid polymer membrane on the anode side is provided with the first
One surface of the sealing member of the one and one side near the periphery of the current collector
A step of integrally bonded to the surface by fusion, between the polymer film and the cathode side separator, covering the end face of the cathode-side current collector and the cathode end face
Providing a second sealing member, the solid polymer
The peripheral surface of the membrane on the cathode side is fused with the second seal member.
And a step of joining and integrating by wearing .

According to this manufacturing method, a solid polymer type fuel cell excellent in gas sealability can be easily manufactured without strictly defining the dimensions of the frame body for sandwiching the solid polymer membrane as in the conventional case. You can Further, since curling of the solid polymer film at the time of assembling the battery can be prevented, handling of the solid polymer film at the time of assembly is easy. Therefore, the work process proceeds smoothly.

The hot pressing method is the simplest method for the fusion . The conditions of the hot pressing method are: temperature; not less than the glass transition temperature of the solid polymer film, less than the decomposition temperature of the solid polymer film, pressure; 5 kg / cm ² or more and 100 kg
If it is specified to be / cm ² or less, a more excellent gas seal structure can be realized without lowering the battery voltage.

If an adhesive is applied to the contact surface between the current collector and the solid polymer film, a cell structure having even better adhesion can be produced. Here, if a conductive powder is added to the adhesive, the current collecting performance can be improved.

Further, the substantially central portion of one surface of the solid polymer film
The anode, and the other side of the anode facing the anode.
The same as this anode by covering the anode.
A second anode-side current collector having a size covering the cathode.
Second cathode-side current collector having approximately the same size as the lever cathode
The same size as the solid polymer membrane,
The anode and the second anode side current collector are provided in the central portion.
Opened a window to which hydrogen gas is supplied by press fitting
The first anode current collector and the solid polymer film
With the same size, the cathode and the first
2 The cathode side current collector is pressed into contact and fitted into
A first cathode side current collector with a window to be supplied is provided,
Of the first anode side current collector and the first cathode side current collector
Connect the outer periphery of the solid polymer membrane to each outer periphery.
It is characterized in that it is configured to match.

[0015]

DETAILED DESCRIPTION OF THE INVENTION

[Embodiment 1] (Regarding Overall Configuration of Solid Polymer Fuel Cell 1) With reference to the drawings, a solid polymer fuel cell 1 (hereinafter referred to as "fuel cell 1") according to an embodiment of the present invention will be described. While explaining. FIG. 1 is an assembly diagram showing the configuration, and FIG. 2 is a sectional view taken along the line XX in FIG.

Basic unit 100 in this fuel cell 1
Is a current collector 4 having an anode 12 on one surface (lower surface in the drawing) at a position corresponding to the center of the solid polymer film 11.
0, a collector 13 (not visible in FIG. 1) having a cathode 13 (not visible in FIG. 1) on one surface (upper surface in the drawing), and a current collector 41 having vertical and horizontal dimensions equivalent to those of the solid polymer film 11, and the seal member 50 A separator plate 2 in which an integrated cell structure CU1 and a gas channel 21 for sandwiching the cell structure CU1 are formed.
0 and the separator plate 30 in which the gas channels 31 are formed are laminated.

In the fuel cell 1, the cooling water flow passage 1 is formed every time, for example, five such basic units 100 are stacked.
A cooling plate 110 on which 11 is formed is inserted to form a laminated body, and both ends of the laminated body are pressed by a pair of end plates (not shown). The number of basic units 100 to be stacked is set according to the voltage to be output.

The anode gas channels 21 face the anode 12 via the current collector 40, and the cathode gas channels 31 face the cathode 13 via the current collector 41. At the corners of the cell structure CU1, the separator plates 20 and 30, and the cooling plate 110, through holes 121 to form a manifold for reaction gas supply / discharge.
Through holes 121, 123 and 122, 124 are formed on the diagonal lines of the separator plates 20, 30.
Are in communication with the gas channel. Further, through holes 125 and 126 forming a cooling water inflow / outflow manifold are formed in the central portions of a pair of opposing sides of each plate, and communicate with the cooling water flow passage 111.

The structure of such an internal manifold is well known and will not be described in detail for the sake of convenience. Then, the cathode gas supplied to the cathode gas supply manifold is distributed to the plurality of cathode gas channels 31, ..., Used for power generation in the cathode 13, and then discharged from the cathode gas discharge manifold. On the other hand, the anode gas supplied to the manifold for supplying the anode gas is distributed to the plurality of anode gas channels 21 ...
After being used for power generation at the anode 12, it is discharged from a manifold for discharging anode gas.

(Regarding Cell Structure CU1) Next, the cell structure CU1 will be described in detail.
As the solid polymer film 11 in the cell structure CU1, a rectangular perfluorinated ionomer film having a thickness of several tens of μm (for example, 50 μm) having a cation exchange property is used. Besides, Porite as a reinforcing agent in the polystyrene resin, or a perfluorocarbon sulfonic acid having a sulfonic acid group
It is possible to use a mixed film in which trafluoroethylene is mixed, a mixed film of fluorocarbon sulfonic acid and polyvinylidene fluoride as a reinforcing agent, or such a mixed film in which trifluoroethylene is further grafted as a reinforcing agent. .

The seal member 50 is made of an elastic material such as EPDM rubber, and the outer periphery thereof is the solid polymer film 1.
1 has the same size as the outer circumference, and the inner circumference has the anode 1
The outer circumference of 2 and the outer circumference of the current collector 40 have substantially the same dimensions. The current collector 41 is a thin plate of porous carbon that has been subjected to water repellent treatment. For example, a paste-like mixture of carbon powder and fluororesin is applied to commercially available carbon paper, and the applied product is heat treated (for example, It can be prepared by treating at 380 ° C. for 2 hours.

Specific examples of the fluororesin include PTFE, perfluorinated ionomer , and tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer (PF).
A), tetrafluoroethylene-hexafluoropropylene copolymerization (FEP), polychlorotrifluoroethylene (PCTFE), polyvinylidene fluoride (PVD)
F), tetrafluoroethylene-ethylene copolymer (E
TFE) etc. can be mentioned.

After the paste applied is dried, it is further impregnated with a solution in which a fluororesin is dispersed, or sprayed by spraying and then heat-treated to make the current collector 41 uniformly repel water. Treated and the water repellent property is improved. A mixture of a platinum-supported carbon powder and a perfluorinated ionomer was screen-printed on the central portion of the current collector 41 to a predetermined thickness (for example, 30
to form a catalyst layer constituting the cathode 13.

In the current collector 41, the reaction product water generated on the cathode side by the power generation is contacted with the electrode by the water repellent treatment using the mixed paste of the carbon powder and the resin as described above. It does not easily stay in the chamber, and the flowability of the reaction gas is not hindered. Other conductive powders can be used instead of the carbon powder, and even non-conductive substances such as silica gel and zeolite powder can be used as long as they do not affect the conductivity of the current collector 41. Anything can be used.

The current collector 40 is a commercially available carbon paper,
After impregnating an alcohol solution containing 16 wt% of FEP, this is heat-treated at, for example, 380 ° C. for 1 hour, and a catalyst layer constituting the anode 12 is formed on this by screen printing in the same size as that of the cathode. It was produced by cutting off the carbon paper in the peripheral edge portion of.

In the cell structure CU1, the electrode catalyst layer (anode 12 and cathode 13) is the solid polymer film 1.
1, the solid polymer film 11 is interposed between the current collector 40 and the current collector 41 so as to face the current collector 1, and the seal member 50 is arranged around the current collector 40 to produce a laminate. By hot pressing the PTF, which is the binder in the electrode
E, the water repellent agent for the current collector 40, the water repellent agent for the surface of the current collector 41, the solid polymer membrane 11, and the sealing member 50 are all fused and produced integrally (first step). ). The joining method is not limited to the hot pressing method, and other methods such as high frequency melting may be used.

The fusion condition is a temperature not lower than the glass transition temperature of the members used for fusion and not causing thermal decomposition, and the applied pressure depends on the thickness of each member and the constituent materials.
It is preferably 5 kgf / cm ² or more in order to secure the sealing property, and 100 kg / cm ² or less in order to prevent the occurrence of a short circuit of the electrode. In each of the following embodiments, it is desirable that the fusion is similarly performed under the conditions in the above range.

Specific conditions in the hot pressing method are, for example, temperature: 150 ° C., pressure: 50 kg / cm.
² , processing time: 90 sec. In the fusion treatment, an alcohol solution of the same fluororesin as the solid polymer film 11, such as a perfluorinated ionomer , is applied between the solid polymer film 11 and the current collector 41, and the hot press method is applied. If applied, the adhesiveness is further improved by using the resin as an adhesive.

Further, the current collecting performance of the current collector 41 can be improved by joining using a paste in which the above-mentioned fluororesin or the like is not a single coating agent but has excellent conductivity, for example, carbon powder is added and mixed. it can. In this way, when the fluororesin is applied, since this coating agent is a liquid, it can be fused at a lower temperature than when it is not used.

By the above fusion treatment, the current collector 41 is
The electrode peripheral portion 41a and the lower surface peripheral portion 11a of the solid polymer film 11, and the upper surface peripheral portion 11 of the solid polymer film 11
b and the lower surface 50a of the seal member 50 are directly fused. The entire surfaces of the electrodes 12 and 13 facing the solid polymer film 11 are fused to the solid polymer film 11. The cell structure CU1 having the integral structure is provided with a separator plate 20,
The battery stack is assembled by alternately stacking 30 and the like (second step).

In the fuel cell 1 described above, current collection
No seal member is provided to prevent air from leaking out from both ends of the body 41, but air is not
If there is a leak, there is no problem in power generation , and of course
Since it is air, it is neither harmful to humans nor dangerous.

Even if a force such as expansion and contraction acts on the solid polymer membrane 11 and the seal member 50 due to a temperature change due to the battery operation, since the contact surfaces thereof are joined, they are always connected to each other. High adhesion can be maintained, and the solid polymer film 11 and the seal member 50 are not displaced. Furthermore, since there is almost no gap around the electrodes, the resistance to the gas pressure difference (arrow T2 in FIG. 2), which is the basic performance of the gas seal structure, is secured.

That is, the cross leak of the reaction gas and the leakage to the outside are surely prevented, and the power generation can be performed without lowering the gas utilization rate. In the fuel cell 1, in the second step of the stacking process, the solid polymer film 11 is previously fused to the cathode side current collector 41.
1 does not curl in the central direction at its corners, and the solid polymer membrane is easy to handle, and
The deformation of the solid polymer film can be eliminated. That is, the battery assembling work can be performed easily and quickly.

Further, the strength of the film around the electrode can be surely reinforced by the simple method of joining the solid polymer film 11 to the peripheral portion of the current collector 41. [Second Embodiment] A fuel cell 200 according to another embodiment of the present invention will be described with reference to the drawings. FIG. 3 is an assembly diagram showing the main configuration of the fuel cell 200, and FIG.
It is a Y line arrow cross section.

In the present fuel cell 200, the size relationship between the anode side current collector and the cathode side current collector is opposite to that of the fuel cell 1, and a sealing member is interposed on both the anode side and the cathode side. The basic structure of the fuel cell is substantially the same as that of the fuel cell 1 except for the above. As shown in FIGS. 3 and 4, in the fuel cell 200, the anode 2
The current collector 201 on the 02 side has substantially the same vertical and horizontal dimensions as the solid polymer film 203, and the current collector 20 on the cathode 204 side.
Reference numeral 5 has substantially the same vertical and horizontal dimensions as the cathode 204 located at the center of the solid polymer film 203.

At the peripheral portion including the upper and lower surfaces of the current collector 201,
The anode 2 of the solid polymer film 203 into which the seal member 206 made of a quadrangular frame-shaped elastic material is fitted.
The peripheral surface 203a on the 02 side is the lower surface 206a of the seal member 206 and the peripheral lower surface 201a of the current collector 201.
Against the cathode 204 of the solid polymer film 203
Side peripheral surface 203b and the upper surface 207a of the seal member 207.
Form a cell structure CU2 that is joined and integrated.

The upper and lower surfaces of the cell structure CU2 are laminated alternately with basic units sandwiched between the separator plates 210 and 220, with a cooling plate 230 interposed therebetween, to form a fuel cell stack. Both of the separator plates 210, 220 have the separator plate 20,
The gas channels 211 ... And the gas channels 221 ... Are formed similarly to 30, but in the present embodiment, the main surface of the separator plate 210 is so arranged that the ribs 211a. The peripheral portion is cut by an amount corresponding to the thickness d of the seal member 206.

The cell structure CU2 is the cell structure CU.
It is produced in the same manner as 1. That is, the current collector 201 in which the electrode catalyst layer (which constitutes the anode 202) is formed in the central portion.
A seal member 206 is attached to the electrode catalyst layer (cathode 2
04) is formed on the cathode side current collector 205.
And are laminated so that the solid polymer membrane 203 and the catalyst layer face each other, and further, the seal member 207 is arranged around the current collector 205 to prepare a laminated body, and the hot pressing method or the like is performed as described above. The solid polymer film is manufactured by bonding the anode peripheral portion to the current collector 201 and the seal members 206 and 207.

The fuel cell 200 having such a cell structure CU2 has the same effect as the fuel cell 1 of the first embodiment, but the seal members 206 and 207 are arranged on both the anode side and the cathode side. By
It is superior to the gas sealing property in that it can generate electricity while preventing not only hydrogen gas leakage but also air leakage.

As in the present fuel cell, the anode-side current collector 201 is made to have the same size as the solid polymer film 203,
In the structure for sealing the gas by joining the both, it is considered that normally only the joining of the current collector 201 and the solid polymer film 203 does not sufficiently prevent the leakage of the hydrogen gas supplied under pressure. To be Therefore, the sealing member has a sealing structure which is attached to the periphery of the current collector to prevent leakage of hydrogen gas.

[Embodiment 3] In the present embodiment, a dry fuel cell type small fuel cell according to the present invention that can be used as a secondary battery will be described in detail with reference to the drawings. Figure 5
6 is an assembly drawing of the fuel cell 300, and FIG.
FIG.

In the fuel cell 300, the cathode 302 is provided at a position corresponding to the center of both main surfaces of the solid polymer membrane 301.
And an anode 303 are laminated, and a first cathode current collector 306 and a second cathode current collector 304 and a second cathode current collector 305 are interposed so as to face and contact the anode 303 and the cathode 302, respectively. 1. A rectangular parallelepiped cell structure CU3 composed of a laminated body sandwiched by one anode current collector 307 and having contact surfaces of the respective members fused together is placed on a container 308, and the side surfaces facing each other by the crimping members 309 and 310. It is the structure crimped | bonded in.

As the solid polymer film 301, for example, a perfluorinated film having a thickness of 50 μm and a length and width of 10 × 10 cm is used.
Onomer films can be used. The electrodes 302 and 303 used are a method of forming a mixture of platinum-supporting carbon and PTFE by screen printing as described above, or a method of forming a platinum-supporting carbon on carbon paper impregnated with a fluororesin and subjected to water repellent treatment by high temperature heat treatment. , PTFE as a binder and calcium carbonate as a pore-forming agent are mixed and filtered, which is rolled to form a sheet, which is then immersed in 1N nitric acid to remove the pore-forming agent, and to remove porosity. It is also possible to produce an electrode sheet. In the experiment described later, the electrode produced by the latter is used.

The first cathode current collector 306 and the first anode current collector 307 also serve as a holding member for fixing a single cell (comprising a solid polymer film and each electrode), and are made of a solid polymer. A carbon plate having the same vertical and horizontal dimensions as the membrane 301 and having appropriate strength (for example, a thickness of 1 mm), the surface of which has been subjected to a water repellent treatment with a fluororesin such as PTFE, and the center thereof. Each part has electrodes 302 and 3
03 and the window 30 of vertical and horizontal dimensions slightly smaller than the second cathode current collector 304 and the second anode current collector 305.
6a and window 307a are opened.

The reason why the windows 306a and 307a are made slightly smaller in this way is that the second current collectors 304 and 305 are used.
This is because the current is brought into contact with the first current collectors 306 and 307 to collect current. The second current collectors 304 and 305 are gas-permeable carbon paper that has been subjected to a water repellent treatment with a fluororesin such as PTFE having the same vertical and horizontal dimensions as the anode 302 and the cathode 303. By providing the second current collectors 304 and 305, the current collection performance of the battery is improved.

The first current collectors 306 and 307, the second current collectors 304 and 305, the electrodes 302 and 303, and the solid polymer film 301 described above are laminated in a predetermined order, and the hot press is performed on the laminated body. Then, the cell structure CU3 in which the respective members are joined is formed by performing the process of the method. Regarding the hot press method, as shown in FIG. 6, it is desirable to perform it so that the contact portions of the second current collectors 304 and 305 with the first current collectors 306 and 307 are crushed. As a result, the gas sealability is improved. Here, the second current collector 304,
If the peripheral portion of 305 is crushed until it does not have gas diffusibility, the gas sealing property is further improved.

The production of the cell structure CU3 is not limited to this. First, the anode 303 and the cathode 302 are pressure-bonded to the solid polymer film 301 by hot pressing, and then the solid polymer film 301 and the 1 current collector 30
6 and 307, a fluororesin solution such as a perfluorinated ionomer is applied and further heat-treated in the same manner so that each member is more reliably fused and excellent in conductivity, such as carbon powder and fluororesin. It is also possible to improve the current collecting performance by using the mixed paste of (1) as the coating agent.

Next, the container 308 is a rectangular columnar molded body in which a space for storing hydrogen, that is, a hydrogen gas storage chamber is formed, and the upper surface of the container wall is equivalent to the solid polymer film 301. Of the anode 303 and the second current collector 3
Window 308 for hydrogen gas supply with vertical and horizontal dimensions approximately equal to 05
a has been opened. A replenishment port 308b (see FIG. 6) for replenishing hydrogen gas from the outside is provided at the bottom of the vessel wall of the container 308. The supply port 308b shown in FIG.
A rubber packing is fitted into a circular hole penetrating the bottom surface of the container wall of the container 308 so that hydrogen gas can be easily replenished from the outside by syringe injection.

In addition to this, the supply port 308b may be constructed by attaching a small check valve (used for a tire tube) or an opening / closing valve. The container wall of the container 308 and the pressure bonding members 309 and 310 are the cell structure CU3.
It is formed by an insulating plate having a strength suitable for sandwiching and fixing, and a specific example of the insulating plate is
Examples thereof include a resin plate, a ceramics plate, and a metal plate coated with a non-conductive material.

The pressure-bonding members 309 and 310 are U-shaped cross-sections that cover the other opposing side surfaces of the laminated body, and are elastic members having strength such that the laminated body can be pressure-bonded and fixed. Further, in order to prevent a short circuit between the first current collector 306 and the current collector 307, the pressure-bonding members 309 and 310 are formed of an insulating material such as resin or ceramics, or when formed of a metal plate, the surface It is desirable to place an insulator in the.

As described above, the fuel cell 300 having such a structure has the effect of reliably improving the gas sealing performance. That is, the first
By bonding the peripheral edge portions of both the current collectors 306 and 307 and the substantially entire peripheral edge portion around the electrodes of the solid polymer film 301, it is possible to reliably realize a gas seal structure having excellent durability as described above. There is.

If the second current collector is made larger than the electrode and has the same vertical and horizontal dimensions as the solid polymer film, its reliability is further improved. In addition, a further characteristic point of this fuel cell is
This is a point that a sealing structure is realized without disposing a resinous sealing member such as a poly-tetra-fluoro-ethylene sheet . As a result, the organic substance in the seal member is eluted during power generation, and it is possible to avoid an adverse effect on the ionic conductivity of the solid polymer membrane.

[Experiment 1] Based on the third embodiment, test batteries A to H were manufactured by using the following members and changing the sealing conditions such as pressure and bonding form as shown in Table 1. (Each member used) Solid polymer membrane; Perfluorinated ionomer , 5 cm x 8 c
m, thickness 50 μm electrode; 2.3 cm × 2.8 cm, thickness 50 μm, catalyst layer made of platinum-supporting carbon.

Second current collector: 2.3 cm × 2.8 cm, thickness 200 μm First current collector: 5 cm × 8 cm, thickness 1 mm, 2 cm × 2.5 cm in the central part of the current collector on the anode side
The windows were opened, and the members were laminated and hot pressed under the conditions shown in Table 1 to fabricate cell structures A to H in which the respective members were joined.

[0055]

[Table 1]

The cell structures A to H were placed on a container in which a gas injection pipe having an injection valve was inserted into the side wall, and a window having vertical and horizontal dimensions of 2 cm × 2.5 cm was opened at the center of the upper surface. It is placed and clamped and fixed by a pressure-bonding member on the opposite side surfaces, and FIG. 7 (FIG. 7A is a vertical sectional view of the entire battery, and FIG. 7B is a top view). Test batteries A to H as shown in were prepared.

In each of the test batteries A to H, the cathode side current collector was not provided with a window for introducing air, but this was used to evaluate the gas tightness of the seal structure. It has such a structure. Battery I of the comparative example, a single cell having electrodes formed on both surfaces of the solid polymer membrane, frame-like port having a predetermined thickness between the first current collector and the polymer electrolyte membrane
With the interposition of the Li-tetra-fluoro-ethylene sheet ,
It was produced by sandwiching it with a container for hydrogen gas storage with a crimping member. Here, the materials and dimensions of each member are the same as those of the test batteries A to H.

With respect to the batteries A to I produced as described above, the sealing performance of the enclosed hydrogen gas was evaluated. A pressure gauge was installed at the inlet of the gas injection pipe, and the initial leak amount and the leak amount after storage were measured. The initial leak amount was measured immediately after the battery was assembled, and the change amount of the hydrogen gas pressure in the container after 3 hours from the start of the measurement was taken as the initial leak amount.

The amount of leak after storage was measured after the battery was assembled and stored for one month with the injection valve closed and hydrogen gas not leaking. The hydrogen gas was measured 3 hours after the start of measurement in the same manner as above. The amount of change in pressure was taken as the value.
The initial hydrogen gas filling pressure was 1.2a for both.
set to tm. The measurement results are shown in Table 1 above. As shown in this figure, it is understood that if the pressure of the hot press is less than 5 kg / cm ² , sufficient sealing property cannot be obtained. Above 5 kg / cm ² , conventional poly-tetraf
It can be seen that, although the initial performance is the same as that of the sealing structure using the Luoro-ethylene sheet, the sealing property does not deteriorate even after long-term storage and the durability is excellent.

[Experiment 2] In the fuel cell used in this experiment, as shown in FIG. 8, a window for introducing air was opened at a position corresponding to the cathode of the cathode side current collecting plate, and the opposite side wall of the container was provided. The batteries A ′ to I ′ are configured in the same manner except that a hydrogen gas injection pipe and a hydrogen gas discharge pipe are inserted therein, including sealing conditions.

Immediately after the assembling of the batteries A ′ to I ′, the cell voltage mV when the hydrogen gas was constantly injected from the injection tube and the power was generated at the current density of 200 mA / cm ²
Was measured. The results are shown in Table 2.

[0062]

[Table 2]

As shown in the figure, the sealing pressure is 5k.
If it is less than g / cm ² , the voltage decreases as shown by the voltage value of the battery A ′. This is because the sealing property is not sufficient. Further, when the pressure exceeds 100 kg / cm ² , the voltage further decreases as shown by the voltage value of the battery F ′. It is considered that this is because the pressure at the time of sealing was too high and the electrodes were short-circuited.

Next, the difference between the voltages of the batteries G'and H'shows that the use of carbon paste as the coating material improves the cell voltage as compared with the case where carbon is not used.
Although the experimental data is not described, an experiment was conducted to compare the voltage value with the second current collector interposed and the voltage value without the second current collector. Showed a higher voltage.

[Other Matters] (1) In the first and second embodiments described above, the case of the internal manifold type having an excellent gas sealing property has been described, but needless to say, the external manifold is used. Even with a battery configuration, it can be similarly implemented. (2) In the third embodiment, the first current collector serves both as a current collector and a cell sandwicher. However, the present invention is not limited to this, and the same applies to the case where the first current collector and the sandwiching member are separate bodies. It is feasible. In addition, if the first current collector in the third embodiment is integrated, there is an advantage that the number of battery constituent members can be reduced.

(3) In the fuel cell according to the third embodiment, the cell structure CU is placed on a container which requires a space for hydrogen storage.
I mentioned the secondary battery specification with 3 mounted,
The cell structures CU3 may be arranged in a matrix, and a hydrogen gas supply manifold may be attached to the cell structures CU3 to implement the same. (4) In each of the cell structures CU1 to CU3 described above, the fusion was due to the fluororesin of the constituent member. However, regarding fusion of the solid polymer film and the current collector, carbon paper not subjected to the water repellent treatment was used. A so-called baking may be performed by directly applying a hot pressing method or the like. In this case as well, it is necessary that the solid polymer membrane is not decomposed.

[0067]

As described above, according to the present invention, the present invention provides a solid body including a cathode side current collector, a cathode, a solid polymer film, an anode, and an anode side current collector. In a polymer fuel cell, an anode and a cathode are located on the main surface of the solid polymer membrane, substantially in the center, and at least one of the anode-side current collector and the cathode-side current collector is larger than adjacent electrodes, Since the outer peripheral portion of the solid polymer film is joined to the current collector, a gas seal structure having excellent durability is surely realized.

As described above, one of the anode-side current collector and the cathode-side current collector is formed larger than the anode or the cathode, and the outer peripheral portion of the solid polymer film is the outer peripheral portion of the current collector. Since they are joined and integrated , a gas seal structure having excellent durability can be realized, and at least the gas seal of hydrogen gas is improved.

[Brief description of drawings]

FIG. 1 is an essential part assembly view of a polymer electrolyte fuel cell according to a first embodiment.

FIG. 2 is a cross-sectional view of the polymer electrolyte fuel cell after assembly in FIG.

FIG. 3 is an essential part assembly view of a polymer electrolyte fuel cell according to another embodiment.

4 is a cross-sectional view of the polymer electrolyte fuel cell after assembly in FIG.

FIG. 5 is an assembly diagram of a polymer electrolyte fuel cell according to another embodiment.

6 is a cross-sectional view of the polymer electrolyte fuel cell after assembly in FIG.

FIG. 7 is a cross-sectional view and a front view of a polymer electrolyte fuel cell used in an experiment.

FIG. 8 is a cross-sectional view and a front view of a polymer electrolyte fuel cell used in another experiment.

FIG. 9 is a configuration diagram of a main part of a conventional polymer electrolyte fuel cell.

FIG. 10 is a main part configuration diagram and a sectional enlarged view of another conventional polymer electrolyte fuel cell.

[Explanation of symbols]

1 Polymer electrolyte fuel cell 11 Solid polymer membrane 12 Anode 13 cathode 20,30 Separator plate 40,41 Current collector 50 seal member 200 Polymer electrolyte fuel cell 201,205 Current collector 202 anode 203 Solid polymer membrane 204 cathode 206,207 Seal member 210,220 Separator plate 300 polymer electrolyte fuel cell 301 solid polymer membrane 302 cathode 303 Anode 304,305 Second current collector 306, 307 1st current collector 308 container 309, 310 Crimping member

Front page continuation (72) Minor Kaneko 2-5-5 Keihan Hondori, Moriguchi City, Osaka Prefecture Sanyo Electric Co., Ltd. (72) Yo Hamada 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Machinery Co., Ltd. (72) Inventor Yasuo Miyake 2-5-5 Keihan Hondori, Moriguchi City, Osaka Sanyo Electric Co., Ltd. (56) Reference JP-A-7-220742 (JP, A) JP-A-6- 68899 (JP, A) JP 8-185875 (JP, A) Special Table 8-509571 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) H01M 8/02 H01M 8 /Ten

Claims (8)

(57) [Claims] 1. A solid polymer membrane is provided with an anode at substantially the center of one surface thereof, a cathode is provided on the other surface thereof so as to face the anode, and the anode is covered with an anode-side current collector and the cathode is covered with the cathode. A cathode-side current collector, and a cathode-side current collector that covers both of the current-collectors and that is larger than the anode and the cathode and that is provided with an anode-side separator for supplying hydrogen gas and a cathode-side separator for supplying air. Is larger than the cathode, and the outer peripheral portion of the solid polymer film is joined to the outer peripheral portion of the cathode side current collector.
Configured to integrate, the solid between the polymer membrane and the anode side separator, the seal member covering the end face of the anode-side current collector and the anode end face the solid high content
Sub-membrane, the anode side separator, the anode end surface and
And a solid polymer fuel cell, which is provided integrally with the anode side current collector . 2. A solid polymer film is provided with an anode on substantially the center of one surface thereof, a cathode on the other surface thereof so as to face the anode, and covers the anode with an anode side current collector and the cathode. A cathode-side current collector, and a hydrogen gas supply anode-side separator and an air supply cathode-side separator, which are larger than the anode and the cathode, are provided to cover both the current collectors, and the anode-side current collector. Lap
The edge is provided a first seal member for crown wears, the magnitude of the anode-side current collector are larger than the anode, the
The peripheral surface of the solid polymer membrane on the anode side is attached to the first shield.
Surface of the collector member and one surface near the periphery of the current collector
To be integrated with the solid polymer film on the cathode side.
Between the peripheral surface peripheral surface of the cathode side separator,
A second sealing member covering the end face of the cathode-side current collector and the cathode end face is provided, cathode of the solid polymer membrane
The peripheral surface on the door side and the second seal member are joined and integrated.
A polymer electrolyte fuel cell characterized by the above. 3. A step of providing an anode on a substantially central portion of one surface of a solid polymer membrane, a cathode on the other surface of the solid polymer membrane so as to face the anode, and an anode side current collector covering the anode, the cathode And a step of providing a cathode side current collector, and a step of covering both of the current collectors, the anode side separator for hydrogen gas supply and the cathode side separator for air supply larger than the anode and the cathode, The cathode-side current collector is made larger than the cathode, and the outer periphery of the cathode-side current collector is joined to the outer periphery of the solid polymer film by fusion to be integrated.
And a step of providing, between the solid polymer film and the anode-side separator, a seal member that covers the end surface of the anode and the end surface of the anode-side current collector, and a peripheral edge portion of the solid polymer film. And directly with the sealing member
And a step of fusing . A method for manufacturing a polymer electrolyte fuel cell, comprising: 4. A step of providing an anode on substantially the center of one surface of a solid polymer membrane, and a cathode on the other surface so as to face the anode, and an anode side current collector covering the anode, And a step of providing a cathode side current collector, and a step of covering both of the current collectors, the anode side separator for hydrogen gas supply and the cathode side separator for air supply larger than the anode and the cathode, By covering the peripheral portion of the anode side current collector
Providing a first seal member, and increasing the size of the anode side current collector to be larger than that of the anode ,
The peripheral portion of the body polymer film on the anode side is connected to the first sheet.
Between one surface of the conductive member and one surface near the periphery of the current collector by fusion bonding and integrating, and between the solid polymer film and the cathode side separator, providing a second <br/> sealing member covering the end face of the end face of the cathode and the cathode-side current collector, mosquitoes of the solid polymer membrane
The peripheral surface on the sword side and the second seal member are fused together.
A method for manufacturing a polymer electrolyte fuel cell, comprising the steps of: re-bonding and integrating . 5. The method for producing a polymer electrolyte fuel cell according to claim 3, wherein the step of joining by fusion uses fusion by a hot pressing method. 6. The conditions for fusion by the hot pressing method are as follows:
The temperature is not lower than the glass transition temperature of the solid polymer film and lower than the decomposition temperature of the solid polymer film, and the pressure is 5 kg / cm ^2.
The method for producing a polymer electrolyte fuel cell according to claim 5, wherein the pressure is 100 kg / cm ² or less. 7. The method for producing a polymer electrolyte fuel cell according to claim 5, further comprising a sub-step of applying an adhesive to a contact surface between the current collector and the polymer electrolyte membrane. 8. The method for producing a polymer electrolyte fuel cell according to claim 7, wherein electrically conductive powder is added to the adhesive.