JPH10289722A - Solid macromolecular type fuel cell and manufacture therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a solid macromolecular fuel cell, having a positively superior gas-sealing structure. SOLUTION: A cathode-side collector 41 is the same as a solid macromolecular membrane in size. A collector 40 having an anode 12, the solid macromolecular membrane 11 and the collector 41 having a cathode 13 at its center are laminated. A cell structure CU1 integrated by fusing each contact part of them by the hot press method and separator plates 20, 30 are alternately laminated to form a layered product.

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 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, they are not visible on the back of the solid polymer film 11) are arranged in the center of the solid polymer film 411, A pair of ribbed separator plates 420 and 430 that sandwich
The separator plate 420,
A pair of current collectors 4 interposed between 430 and cell 410
40, 441, and sealing members 450, 460 that seal this portion interposed between the outer peripheral portions of the separator plates 420, 430 and the cells 410, and are stacked on the separators 420, 430. Each supplies gas to generate electric power.

In the above polymer electrolyte fuel cells,
The outer peripheral portion is sealed to prevent the supplied hydrogen gas and air from leaking. That is, as shown in FIG. 9, by pressing the periphery of the main surface of the solid polymer film 411 with the sealing members 450 and 460, a gas sealing structure having excellent gas sealing properties is realized.

However, in the gas seal structure, when the solid polymer film is simply pressed from above and below by the seal members 450 and 460, if the tightening force gradually decreases with the operation of the battery, the seal member and the solid high There is a problem that the gas sealing property is deteriorated due to a shift in the arrangement state with the molecular film. On the other hand, Japanese Patent Application Laid-Open No. 5-283093 discloses
Japanese Patent Application Laid-Open Publication No. H10-26095 discloses a solid polymer membrane 5 as shown in FIG.
The electrodes 502 and 503 are opposed to the central portion of the first electrode 01, and frame-shaped rubber sheets 504 and 505 as seal members are provided around the electrodes 502 and 503. (See (b)), a structure 510 in which a rubber sheet is press-bonded to a solid polymer film is obtained by thermocompression-bonding the layered body arranged as described above, and this is alternately stacked with separators 520 and 530. By
There is disclosed a polymer electrolyte fuel cell which overcomes the above-mentioned problem such as a decrease in gas sealing performance.

[0005]

In a polymer electrolyte fuel cell, if there is usually a gap between the outer periphery of the electrode and the inner periphery of the sealing member, the solid polymer membrane is formed by the differential pressure of the reaction gas. It can be loose or damaged. In order to prevent such membrane damage also in the fuel cell disclosed in the above publication, it is necessary to strictly adjust the dimensions of the inner periphery of the seal member and the outer periphery of the electrode, but it is considered that in practice, manufacturing difficulty is involved. .

In addition, the strength of the peripheral portion of the solid polymer film decreases due to the tension generated by the expansion and contraction of the solid polymer film. If the strength decreases, the solid polymer film itself may be damaged at worst. Therefore, the present invention has been made in view of the above problems, and provides a polymer electrolyte fuel cell with reliably improved gas sealing performance, and a simple manufacturing method thereof. It was made for the purpose of.

[0007]

SUMMARY OF THE INVENTION In order to solve the above-mentioned problems, the present invention provides a solid-state current collector having a cathode-side current collector, a cathode, a solid polymer film, an anode, and an anode-side current collector. In the molecular fuel cell, the main surface of the solid polymer membrane, the anode and the cathode are located at substantially the center, at least one of the anode-side current collector and the cathode-side current collector is larger than the adjacent electrode, The outer peripheral portion of the polymer film is bonded to the current collector.

[0008] Thus, a gas seal structure having excellent durability is surely provided. That is, in particular, the structure is such that the peripheral portion of the solid polymer film, whose strength tends to decrease, is joined to the current collector to reinforce the strength of the peripheral portion of the film. Therefore, it is possible to reliably prevent the membrane from being damaged due to the gas differential pressure and the expansion and contraction of the membrane itself. Moreover, according to such a configuration, the gap around the electrodes can be eliminated without strictly adjusting the dimensions, and thus the gas seal structure can be easily manufactured.

[0009] In this configuration, a sealing member may be arranged on the periphery of the current collector smaller than the electrode facing the current collector in a state of being joined to the solid polymer film. Further, a sealing member may be fitted to the periphery of the larger current collector, and the sealing member may be joined to the solid polymer film. By thus arranging the seal member by bonding it to the solid polymer membrane, the gas sealing performance of the anode gas is further improved.

The method for manufacturing a solid polymer fuel cell having the above structure is a structure in which an anode-side current collector, an anode, a solid polymer membrane, a cathode, a cathode-side current collector, and a sealing member are integrated by fusion. And a second step of forming a laminate by sandwiching the structure obtained in the first step between a pair of pressing plates to form a laminate. Can be. Note that the presser plate referred to here substantially means a separator plate.

According to this manufacturing method, it is possible to easily produce a polymer electrolyte fuel cell having excellent gas sealing properties without having to strictly define the dimensions of the frame holding the solid polymer membrane as in the prior art. Can be. Further, curling of the solid polymer film during battery assembly can be prevented, so that handling of the solid polymer film during assembly is easy. Therefore, the work process proceeds smoothly.

Here, the fusion in the first step is as follows:
Hot pressing is the simplest method. The conditions of the hot pressing method are as follows: temperature; above the glass transition temperature of the solid polymer membrane, below the decomposition temperature of the solid polymer membrane, pressure; 5 kg / c
When it is specified to be not less than m ^{2 and not} more than 100 kg / cm ² , a more excellent gas seal structure can be realized without lowering the battery voltage.

In a sub-step of the first step, if an adhesive is applied to the contact surface between the current collector and the solid polymer film, a cell structure having better adhesion can be manufactured. Here, if a material obtained by adding a conductive powder to the adhesive is used, the current collecting performance can be improved. Also,
In a polymer electrolyte fuel cell, a cell in which an anode and a cathode are arranged at positions opposing each other on the main surface of a solid polymer membrane, and a cell having substantially the same vertical and horizontal dimensions as the solid polymer membrane and a substantially central portion thereof Anode current collector and window
The cathode current collector may be sandwiched such that the window faces each electrode, and the solid polymer film and the current collector may be joined as described above.

Here, the number of battery components can be reduced by allowing the current collector to also serve as the holding member. Also, if a second current collector having gas permeability is interposed at least between the first current collector and the electrode,
The current collecting performance can be improved.

[0015]

BEST MODE FOR CARRYING OUT THE INVENTION

Embodiment 1 (Overall Configuration of Polymer Electrolyte Fuel Cell 1) A polymer electrolyte fuel cell 1 (hereinafter referred to as “fuel cell 1”) according to an embodiment of the present invention will be described with reference to the drawings. I will explain it. FIG. 1 is an assembly view showing the configuration, and FIG. 2 is a sectional view taken along line XX in FIG.

The basic unit 100 of the fuel cell 1
Is a current collector 4 in which an anode 12 is disposed on one surface (the lower surface in the drawing) at a position corresponding to the center of the solid polymer film 11.
0, a current collector 41 having a cathode 13 (not shown in FIG. 1) on one side (upper surface in the drawing) and having the same vertical and horizontal dimensions as the solid polymer film 11 and a sealing member 50 are joined. An integrated cell structure CU1 and a separator plate 2 in which gas channels 21 sandwiching the cell structure CU1 are formed.
And a separator plate 30 on which gas channels 31 are formed.

The fuel cell 1 has a cooling water flow path 1 every five such basic units 100 are stacked.
The laminated body is formed by interposing the cooling plate 110 in which the 11 is formed, 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 are opposed to the anode 12 via a current collector 40, and the cathode gas channels 31 are opposed to the cathode 13 via a current collector 41. At each corner of the cell structure CU1, the separator plates 20, 30 and the cooling plate 110, through-holes 121 to 121 constituting a manifold for supplying and discharging the reaction gas are provided.
124 are opened, and the through holes 121, 123 and 122, 124 located on diagonal lines of the separator plates 20, 30.
Is in communication with the gas channel. Further, through holes 125 and 126 constituting a cooling water inflow / outflow manifold are opened at the center of a pair of opposite 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 convenience. Then, the cathode gas supplied to the cathode gas supply manifold is distributed to the plurality of cathode gas channels 31 and used by the cathode 13 for power generation, and then discharged from the cathode gas discharge manifold. On the other hand, the anode gas supplied to the anode gas supply manifold 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 membrane 11 in the cell structure CU1, a rectangular Nafion membrane (manufactured by DuPont) having a thickness of several tens of μm (for example, 50 μm) having a cation exchange property is used. In addition, polytetrafluoroethylene (Teflon, manufactured by DuPont, PTF) is used as a reinforcing agent for a polystyrene resin having a sulfonic acid group or a perfluorocarbon sulfonic acid.
E), a mixed film of fluorocarbon sulfonic acid and polyvinylidene fluoride as a reinforcing agent,
A material obtained by further grafting trifluoroethylene as a reinforcing agent to such a mixed film can be used.

The seal member 50 is made of an elastic material, for example, EPDM rubber, and its outer periphery is
1 has the same dimensions as the outer circumference of the anode 1
2 and the outer periphery of the current collector 40. The current collector 41 is a water-repellent thin plate of porous carbon. For example, a paste-like mixture of carbon powder and a fluororesin is applied to a commercially available carbon paper, and the applied material is subjected to a heat treatment (for example, The treatment is performed at 380 ° C. for 2 hours.)

Specific examples of the fluororesin include, in addition to PTFE, Nafion, tetrafluoroethylene-perfluoroalkylvinylether copolymer (PFA), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), polychlorotrifluoroethylene. (PCT
FE), polyvinylidene fluoride (PVDF), tetrafluoroethylene-ethylene copolymer (ETFE) and the like.

After the paste is dried, the current collector 41 is uniformly impregnated with water by impregnating with a solution in which a fluororesin is dispersed or spraying the solution with a spray and heat-treating the solution. Treated and water repellency is improved. A catalyst layer constituting the cathode 13 is formed by applying a mixture of carbon powder carrying platinum and Nafion to a central portion of the current collector 41 to a predetermined thickness (for example, 30 μm) by a screen printing method. It is formed.

In the current collector 41, the water produced by the water repellent treatment using the mixed paste of the carbon powder and the resin as described above causes the reaction product water generated on the cathode side by the power generation to be brought into contact with the electrode. And the flowability of the reaction gas is not hindered. It should be noted that other conductive powders can be used in place of the carbon powder, and even a non-conductive substance such as silica gel or zeolite powder is used to such an extent that the conductivity of the current collector 41 is not affected. Anything can be used.

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

In the cell structure CU1, the electrode catalyst layers (the anode 12 and the cathode 13) are made of the solid polymer membrane 1
The solid polymer film 11 is interposed between the current collector 40 and the current collector 41 so as to be opposed to 1, and a sealing member 50 is arranged around the current collector 40 to form a laminate. By hot pressing, PTF as a binder in the electrode
E, the water repellent of the current collector 40, the water repellent of the surface of the current collector 41, the solid polymer film 11, and the sealing member 50 are all fused to be integrally formed (first step). ). The joining method is not limited to the hot pressing method, and may be high-frequency melting or the like.

The fusing conditions are not lower than the glass transition temperature of the members to be subjected to fusing and do not cause thermal decomposition. The applied pressure depends on the thickness of each member and the constituent materials.
It is preferable that the pressure is 5 kgf / cm ² or more in order to secure the sealing property, and it is preferable that the pressure is 100 kg / cm ² or less in order to prevent occurrence of short circuit of the electrode. In each of the following embodiments, it is preferable that the fusion be performed under the above-described conditions.

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

Furthermore, the current collecting performance of the current collector 41 can be improved by bonding using a paste obtained by adding and mixing, for example, carbon powder, which is excellent in conductivity, instead of the above-mentioned fluororesin or the like as a single coating agent. it can. As described above, when the fluororesin is applied, since the coating agent is a liquid, it can be fused even at a lower temperature than when not using it.

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

In the fuel cell 1 described above, no seal member is provided for preventing air from leaking to the outside, but there is no problem in power generation. (Effects of Fuel Cell 1) In the fuel cell 1, a gas seal structure having excellent durability is reliably realized. That is, since the solid polymer film 11 is joined to and integrated with the current collector 41 at the peripheral portion, that is, the portion around the electrodes, the structure is such that the strength is reliably reinforced at the peripheral portion. Accordingly, the resistance to the tension (arrow T1 in FIG. 2) acting in the plane direction due to the expansion and contraction of the film itself is also reliably improved, and damage to the film due to the tension can be avoided.

Even if a force such as expansion and contraction acts on the solid polymer membrane 11 and the sealing member 50 due to a temperature change accompanying the operation of the battery, the contact surfaces thereof are joined. High adhesion can be maintained, and the positions of the solid polymer film 11 and the seal member 50 do not shift. Further, since there is almost no gap around the electrode, the resistance to the gas pressure difference (arrow T2 in FIG. 2) as a basic performance in the gas seal structure is secured.

That is, cross-leakage and leakage of the reaction gas to the outside are reliably prevented, and power can be generated without lowering the gas utilization rate. In the fuel cell 1, since the solid polymer film 11 is previously fused to the cathode-side current collector 41 in the second stacking step, the solid polymer film 1
1 does not curl toward the center at the corners, so that the handling of the solid polymer membrane is easy, and
The deformation of the solid polymer film can be eliminated. That is, the battery assembling operation can be performed easily and quickly.

Further, by a simple method of joining the solid polymer film 11 to the peripheral portion of the current collector 41, the strength of the film around the electrode can be surely reinforced. [Embodiment 2] 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 a main configuration of the fuel cell 200, and FIG.
FIG. 4 is a sectional view taken along line Y.

In the 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 1 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 cathode 204 side has the same vertical and horizontal dimensions as the solid polymer film 203.
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.

In the peripheral portion including the upper and lower surfaces of the current collector 201,
A seal member 206 made of a resilient material having a quadrangular frame shape is fitted therein, and the anode 2 of the solid polymer film 203 is inserted.
The peripheral surface 203a on the 02 side is the lower surface 206a of the seal member 206 and the lower surface 201a near the periphery of the current collector 201.
And the cathode 204 of the solid polymer film 203
Side peripheral surface 203b and upper surface 207a of seal member 207
Are joined and integrated to constitute a cell structure CU2.

A basic unit in which the upper and lower surfaces of the cell structure CU2 are sandwiched between separator plates 210 and 220 is alternately laminated with a cooling plate 230 interposed therebetween to form a fuel cell stack. Both the separator plates 210 and 220 have the separator plates 20 and
30 and gas channels 221 are formed in the same manner as in FIG. 30, but in the present embodiment, the main surface of the separator plate 210 is arranged so that the ribs 211a contact the anode-side current collector 201 during lamination. The peripheral portion is cut by the thickness d of the seal member 206.

The cell structure CU2 is the same as the cell structure CU.
It is manufactured similarly to 1. That is, the current collector 201 having the electrode catalyst layer (constituting the anode 202) formed at the center.
A sealing member 206 is mounted on the electrode catalyst layer (cathode 2).
04) is formed on the cathode-side current collector 205.
Are laminated so that the solid polymer film 203 and the catalyst layer are opposed to each other, and a sealing member 207 is arranged around the current collector 205 to produce a laminated body, which is subjected to a hot press method or the like as described above. Thus, the solid polymer membrane is produced by joining the peripheral portion of the anode to the current collector 201 and the sealing 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 sealing members 206 and 207 are disposed on both the anode side and the cathode side. By having
It is superior in gas sealing performance in that power can be generated while preventing not only leakage of hydrogen gas but also leakage of air.

As in the present fuel cell, the anode-side current collector 201 is made the same size as the solid polymer membrane 203,
In a structure in which a gas is sealed by joining both, it is considered that leakage of the hydrogen gas supplied under normal pressure is not sufficiently prevented by merely joining the current collector 201 and the solid polymer film 203. Can be Therefore, the sealing member has a sealing structure in which the sealing member is mounted on the periphery of the current collector, thereby preventing leakage of hydrogen gas.

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

The fuel cell 300 has a cathode 302 at a position corresponding to the center of both main surfaces of the solid polymer membrane 301.
And the anode 303 are stacked, and the first cathode current collector 306 and the second cathode current collector 306 are interposed with the second cathode current collector 304 and the second anode current collector 305 interposed therebetween so as to face the anode 303 and the cathode 302. 1. A rectangular parallelepiped cell structure CU3 composed of a laminate sandwiched by one anode current collector 307 and having the contact surfaces of the members fused together is placed on the container 308, and the crimping members 309 and 310 face the opposite side surfaces. Is a configuration crimped.

As the solid polymer film 301, for example, a Nafion film having a thickness of 50 μm and a length and width of 10 × 10 cm can be used. Electrodes 302 and 303 used
As described above, a method of forming a mixture of platinum-carrying carbon and PTFE by screen printing on carbon paper that has been impregnated with a fluororesin and subjected to a water-repellent treatment by a high-temperature heat treatment, PTFE and calcium carbonate as a pore-forming agent are mixed, filtered, rolled and formed into a sheet, and then immersed in 1N nitric acid to remove the pore-forming agent, thereby producing a porous electrode sheet. You can also. In the experiment described later, the electrode manufactured by the latter is used.

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

The reason why each of the windows 306a and 307a is made slightly smaller is that the second current collectors 304 and 305
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 fluorine resin 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 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 are laminated in a predetermined order. The cell structure CU3 in which the respective members are joined by performing the process of the method. As for the hot press method, as shown in FIG. 6, it is preferable to perform the hot press method 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 sealing property becomes more excellent. Here, the second current collector 304,
If the peripheral portion of 305 is crushed until it has no gas diffusion property, the gas sealing property is further improved.

The fabrication 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. 1 current collector 30
By applying a fluororesin solution such as Nafion between 6 and 307 and subjecting it to a similar heat treatment,
The current collecting performance can also be improved by more reliably fusing each member or using a mixed paste of, for example, carbon powder and a fluororesin having excellent conductivity as the coating agent.

Next, the container 308 is a space in which hydrogen is stored, that is, a rectangular column-shaped molded body having a hydrogen gas storage chamber formed therein. The anode 303 and the second current collector 3
Window 308 for supplying hydrogen gas with the same vertical and horizontal dimensions as 05
a has been established. At the bottom of the container wall of the container 308, a supply port 308b (see FIG. 6) for supplying hydrogen gas from the outside is provided. The supply port 308b shown in FIG.
A rubber packing is formed in a circular hole penetrating the bottom surface of the container wall of the container 308, so that hydrogen gas can be easily supplied from the outside by syringe injection.

The supply port 308b can also be configured 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 crimping members 309 and 310 are formed by the cell structure CU3.
Is formed by an insulating plate having a strength suitable for fixing with sandwiching, and as a specific example of the insulating plate,
Examples thereof include a resin plate, a ceramic plate, and a metal plate coated with a non-conductive substance.

The crimping members 309 and 310 are U-shaped in cross section that cover another opposing side surface of the laminate, and are elastic members having such strength that the laminate can be crimped and fixed. 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 may be formed of an insulating material such as resin or ceramics or a metal plate. It is desirable to place an insulator on the surface.

In the fuel cell 300 having such a configuration, as described above, the effect of reliably improving the gas sealing performance can be obtained. That is, the first
Since the peripheral portions of both the current collectors 306 and 307 and the substantially entire peripheral portion around the electrodes of the solid polymer film 301 are joined, a gas seal structure having excellent durability as described above is reliably realized. I have.

If the second current collector is larger than the electrodes and has the same vertical and horizontal dimensions as the solid polymer film, the reliability is further improved. Another characteristic of this fuel cell is that
The point is that a sealing structure is realized without disposing a resin sealing member such as a Teflon sheet. As a result, an organic substance in the seal member is eluted during power generation, and an effect of preventing the organic substance from adversely affecting the ionic conductivity of the solid polymer membrane can be avoided.

[Experiment 1] Based on Embodiment 3, using the following members, the sealing conditions such as the pressure and the joining form are shown in Table 1.
The test batteries A to H were manufactured by changing as shown in FIG. (Each member used) Solid polymer membrane; Nafion, 5 cm × 8 cm, thickness 5
0 μm electrode; 2.3 cm × 2.8 cm, thickness 50 μm, catalyst layer is made of platinum-supported 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 center of the anode-side current collector
These members were laminated, and hot-pressed under the conditions shown in Table 1 to produce cell structures A to H in which the respective members were joined.

[0055]

[Table 1]

The cell structures A to H are placed on a container in which a gas injection pipe having an injection valve is inserted into a side wall and a window of 2 cm × 2.5 cm length and width is opened at the center of the upper surface. The battery is placed, and it is fastened and fixed on the opposing side by a crimping member. FIG. 7 (FIG. 7 (a) is a vertical sectional view of the entire battery, and FIG. 7 (b) is a top view). Test batteries A to H as shown in Table 1 were prepared.

In the test batteries A to H, the current collector on the cathode side is not provided with a window for introducing air, but this is used to evaluate the gas tightness of the seal structure. It has such a configuration. Battery I of the comparative example is a single cell in which electrodes are formed on the front and back surfaces of a solid polymer film, and a frame-shaped Teflon sheet having a predetermined thickness is interposed between the first current collector and the solid polymer film. Then, it was manufactured by sandwiching it together with a container for storing hydrogen gas with a pressure bonding 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 sealed hydrogen gas was evaluated. A pressure gauge was installed at the gas injection pipe inlet, 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 amount of change in the hydrogen gas pressure in the container three hours after the start of the measurement was defined as the initial leak amount.

The leakage amount after storage was measured immediately after assembling the battery, after closing the injection valve and storing for one month in a state in which hydrogen gas did not leak out. The change in pressure was taken as the value.
The initial hydrogen gas filling pressure was 1.2a for both.
tm. Table 1 shows the measurement results. As shown in this figure, if the pressure of the hot press is less than 5 kg / cm ² , it is understood that sufficient sealing properties cannot be obtained. At 5 kg / cm ² or more, although the initial performance is the same as that of the conventional seal structure using a Teflon sheet, the sealability is not deteriorated 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 collector, The batteries A ′ to I ′ have the same construction except that a hydrogen gas injection pipe and a hydrogen gas discharge pipe are inserted.

Immediately after assembling the batteries A ′ to I ′, the cell voltage mV when the power was generated at a current density of 200 mA / cm ² while hydrogen gas was always injected from the injection pipe.
Was measured. Table 2 shows the results.

[0062]

[Table 2]

As shown, the pressure at the time of sealing was 5 k
If it is less than g / cm ² , the voltage decreases as indicated by the voltage value of battery A ′. This is because the sealing property is not sufficient. When the pressure exceeds 100 kg / cm ² , the voltage further decreases as indicated by the voltage value of the battery F ′. This is probably 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' indicates that when a carbon paste is used as the coating material, the cell voltage is improved as compared with the case where no carbon is used.
Although the experimental data is not described, an experiment was performed to compare the voltage value when the second current collector was interposed with the voltage value when the second current collector was not interposed. Showed a higher voltage.

[Other Matters] (1) In the first and second embodiments, the case of the internal manifold system having excellent gas sealing properties has been described. However, it is needless to say that the present invention is not limited to this. The present invention can be similarly applied to a battery configuration. (2) In the third embodiment, the first current collector serves as both the current collector and the cell sandwiching unit. However, the present invention is not limited to this, and the first current collector and the sandwiching member may be separately provided. It is feasible. Note that there is an advantage that the number of battery constituent members can be reduced if they are integrated as in the first current collector in the third embodiment.

(3) In the fuel cell according to the third embodiment, the cell structure CU is placed on a container that requires a space for storing hydrogen.
3 has been mentioned about the secondary battery specification,
The cell structure CU3 may be arranged in a matrix and a hydrogen gas supply manifold may be attached to the cell structure CU3. (4) In each of the cell structures CU1 to CU3, the fusion was performed by the fluorocarbon resin of the constituent member. A so-called baking may be performed by directly applying a hot press method or the like. In this case as well, it is necessary that the solid polymer film does not decompose.

[0067]

As described above, according to the present invention, the present invention provides a solid-state battery comprising a cathode-side current collector, a cathode, a solid polymer film, an anode, and an anode-side current collector. In the polymer fuel cell, the main surface of the solid polymer membrane, the anode and the cathode are located at substantially the center, at least one of the anode-side current collector and the cathode-side current collector is larger than the adjacent electrode, Since the outer peripheral portion of the solid polymer film is bonded to the current collector, a gas seal structure with excellent durability is reliably realized.

Such polymer electrolyte fuel cells range from relatively large ones in which a plurality of cell structures are stacked with a separator plate interposed to dry cell type fuel cells in which only one cell structure is provided. The form can be applied to various things.

[Brief description of the drawings]

FIG. 1 is a main part assembly diagram of a polymer electrolyte fuel cell according to Embodiment 1.

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

FIG. 3 is a main part assembly diagram of a polymer electrolyte fuel cell according to another embodiment.

FIG. 4 is a sectional view of the polymer electrolyte fuel cell after assembly in FIG. 3;

FIG. 5 is an assembly view 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 cross-sectional enlarged view of another conventional polymer electrolyte fuel cell.

[Explanation of symbols]

 REFERENCE SIGNS LIST 1 solid polymer fuel cell 11 solid polymer membrane 12 anode 13 cathode 20, 30 separator plate 40, 41 current collector 50 sealing member 200 solid polymer fuel cell 201, 205 current collector 202 anode 203 solid polymer membrane 204 Cathode 206, 207 Sealing member 210, 220 Separator plate 300 Solid polymer fuel cell 301 Solid polymer membrane 302 Cathode 303 Anode 304, 305 Second current collector 306, 307 First current collector 308 Container 309, 310 Crimping Element

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Minoru Kaneko 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd. (72) Inventor Yo-Hama 2--5 Keihanhondori, Moriguchi-shi, Osaka No. 5 Sanyo Electric Co., Ltd. (72) Inventor Yasuo Miyake 2-5-5 Keihanhondori, Moriguchi-shi, Osaka Sanyo Electric Co., Ltd.

Claims (11)

[Claims] 1. A polymer electrolyte fuel cell including a cathode-side current collector, a cathode, a solid polymer membrane, an anode, and an anode-side current collector, wherein: a main surface of the solid polymer membrane; An anode and a cathode are located at substantially the center, at least one of the anode-side current collector and the cathode-side current collector is larger than an adjacent electrode, and an outer peripheral portion of the solid polymer film is bonded to the current collector. A polymer electrolyte fuel cell. 2. One of the anode-side current collector and the cathode-side current collector is smaller than a solid polymer film, and a sealing member is joined to the solid polymer film at a peripheral portion of the current collector. The polymer electrolyte fuel cell according to claim 1, wherein the fuel cells are arranged in a state. 3. The sealing device according to claim 2, wherein a sealing member is fitted into a periphery of the larger current collector, and the sealing member is joined to the solid polymer film. Solid polymer fuel cell. 4. A cell in which an anode and a cathode are arranged at positions opposing each other on a main surface of a solid polymer membrane, and a window having a size substantially equal to that of the solid polymer membrane and opened at a substantially central portion thereof. 2. The polymer electrolyte fuel cell according to claim 1, wherein the first anode-side current collector and the first cathode-side current collector are sandwiched such that the window faces each electrode. . 5. A gas-permeable second current collector is interposed between at least one of the first anode current collector and the anode and between at least one of the first cathode current collector and the cathode. The polymer electrolyte fuel cell according to claim 4, characterized in that: 6. The solid according to claim 4, wherein the first anode-side current collector and the first cathode-side current collector also serve as a holding member for holding a cell. Polymer fuel cell. 7. A first step of producing a cell structure in which an anode, a solid polymer membrane, and a cathode and at least one of an anode-side current collector and a cathode-side current collector are integrated by fusion. A second step of producing a laminate by sandwiching the cell structure obtained in the first step with a pair of pressing members; and a second method of producing a polymer electrolyte fuel cell. 8. The method for manufacturing a polymer electrolyte fuel cell according to claim 7, wherein in the first step, fusion is performed by a hot press method. 9. In the first step, the fusing conditions by the hot press method are set such that the temperature is equal to or higher 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 set at 5 ° C.
9. The method for producing a polymer electrolyte fuel cell according to claim 8, wherein the pressure is not less than kg / cm ^{2 and not} more than 100 kg / cm ² . 10. The solid according to claim 8, wherein the first step includes a sub-step of applying an adhesive to a contact surface between the current collector and the solid polymer film. A method for producing a polymer fuel cell. 11. The method for manufacturing a polymer electrolyte fuel cell according to claim 10, wherein a conductive powder is added to the adhesive.