JP2000067900A - Polymer electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a miniaturized and compact polymer electrolyte fuel cell excellent in its reliability for gas sealing. SOLUTION: This polymer electrolyte fuel cell is formed by laminating plural cells equipped with a solid polymer electrolyte film, a pair of electrodes with a catalysis reaction layer placed so as to sandwich the polymer electrolyte film, and a means for supplying and distributing fuel gas containing hydrogen to one electrode and supplying and distributing oxidizer gas containing oxygen to the other electrode, through a conductive separator, and a gas manifold 17 for supplying and exhausting the fuel gas and the oxidizer gas to the cell is disposed on the side of the laminated fuel cell in parallel with its longitudinal direction.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a portable power supply,
The present invention relates to a fuel cell used for a power source for an electric vehicle, a cogeneration system in a home, and the like, particularly to a polymer electrolyte fuel cell, and more particularly to an improvement in a manifold configuration of an external manifold fuel cell.

[0002]

2. Description of the Related Art A polymer electrolyte fuel cell uses a fuel gas such as hydrogen and an oxidizing gas containing oxygen such as air.
By electrochemically reacting at the gas diffusion electrode,
Electric power and heat are generated at the same time. An example of a polymer electrolyte fuel cell will be described with reference to FIGS. On both surfaces of a polymer electrolyte membrane 3 for selectively transporting hydrogen ions, a catalytic reaction layer 2 mainly composed of carbon powder carrying a platinum-based metal catalyst is disposed in close contact. On the outer surface of the catalytic reaction layer 2, a diffusion layer 1 having both gas permeability and electronic conductivity is disposed in close contact. The electrode 23 is constituted by the catalytic reaction layer 2 and the diffusion layer 1. The electrode 23
The polymer electrolyte membrane 3 is integrated in advance to form an electrode electrolyte membrane assembly (hereinafter referred to as MEA) 24.

In a general polymer electrolyte fuel cell, a plurality of MEAs 24 are stacked via a conductive separator plate 4 to constitute a so-called stacked battery. The separator plate 4 mechanically fixes the adjacent MEAs 24 and electrically connects them in series. Around the electrodes 23, the sealing material 6 shown in FIG. 2 and the gasket 8 shown in FIG. Is arranged. The sealing material 6 and the gasket 8 are integrated with the MEA 24 in advance. Gasket 8
Is made of, for example, a resin or a metal plate, has a thickness about the same as that of the electrode 23, and a gap between the separator plate 4 and the gasket 8, which are arranged to face each other, is sealed with grease or an adhesive. In recent years, as shown in FIG. 4, as a MEA 24, a resin 10 having a sealing effect is previously impregnated into a portion requiring gas sealing properties, and this is solidified.
A method of ensuring gas sealing between the separator plate 4 and the separator plate 4 has also been proposed.

A gas flow path 5 for supplying a fuel gas and an oxidizing gas to the electrode surface and carrying away a gas generated by the reaction and an excess gas is formed in a portion of the separator plate 4 which comes into contact with the MEA 24. You. The gas flow path 5 can be provided separately from the separator plate 4. However, as shown in FIG.
Is generally used. In the stacked battery, in order to supply the fuel gas and the oxidizing gas to the grooves, the pipes for supplying these gases are branched by the number of the separator plates 4 to be used, and the branch destination is formed directly on the separator plate 4. A mechanism for connecting to the formed groove is required. Further, a mechanism for supplying and discharging cooling water to each unit cell is also required. This mechanism is called a manifold. These manifolds are classified into an internal manifold type and an external manifold type according to the arrangement form. Among them, a type in which a pipe for fuel gas or the like provided outside the battery is directly connected to a gas flow path 5 formed in the separator plate 4 is called an external manifold type. In addition, the internal manifold type is a separator plate that has formed a gas flow path,
A through-hole is provided, the inlet / outlet of the gas flow path is passed to this hole, and fuel gas or the like is supplied directly from this hole.

[0005] Of these, a so-called internal manifold type in which supply and discharge holes for fuel gas and cooling water are secured inside the stacked battery is generally used. However, by reforming city gas,
When the battery is operated using the actual hydrogenated gas, the electrode is poisoned by CO as a result of an increase in the CO concentration in the downstream region of the fuel gas flow path, thereby lowering the temperature and lowering the temperature. May further promote electrode poisoning. In order to alleviate such a phenomenon of lowering the performance of the battery, an external manifold type has been reconsidered as a structure in which a frontage of a gas supply / discharge unit from the manifold to each unit cell is made as large as possible.

In both the internal manifold type and the external manifold type, a plurality of cells including a cooling unit are stacked in one direction, a pair of end plates are arranged at both ends, and the two end plates are fastened between the two end plates. It is necessary to fix with a rod.
As for the tightening method, it is desirable that the unit cells be tightened as uniformly as possible within the plane. From the viewpoint of mechanical strength, a metal material such as stainless steel is usually used for the end plate and the fastening rod. These end plates and fastening rods and the stacked battery are electrically insulated by an insulating plate so that current does not leak out through the end plates. As for the fastening rod, a method of passing through a through hole inside a separator plate and a method of fastening the entire lamination pond with a metal belt over an end plate have been proposed.

Further, in any of the sealing methods shown in FIGS. 2, 3 and 4, in order to maintain the sealing property and to keep the contact resistance between the electrode and the separator plate or between the separator plates small, constant tightening is required. Pressure is required. Therefore, a configuration is adopted in which a screw spring or a disc spring is inserted between the fastening rod and the end plate. By this tightening pressure, electrical contact between components of the battery such as the separator plate, the electrode, and the electrolyte membrane is secured. Many fuel cells have a stacked structure in which a number of cells are stacked. In the case of a fuel cell, a cooling plate is provided for every one or two cells of a unit cell in order to discharge heat generated together with electric power to the outside of the cell. Generally, the cooling plate has a structure in which a heat medium such as cooling water flows through a thin metal plate. As shown in FIGS. 2 to 4, there is also a method in which a flow path is formed on the back surface of the separator plate 4 constituting the unit cell, that is, the surface on which the cooling water is to flow, and the separator plate 4 itself functions as a cooling plate. At that time, an O-ring 7 and a gasket are also required to seal a heat medium such as cooling water. However, in this sealing method, the O-ring is completely crushed to provide sufficient conductivity between the upper and lower sides of the cooling plate. Need to secure.

In the structure of the fuel cell described above, it is necessary to dispose a sealing material or an O-ring around the electrode in order to seal a gas such as hydrogen gas or air. At this time, ME
A needs a margin of about 10 mm for installing a sealant. Further, even in a method in which a resin having a sealing effect is immersed in the MEA to form a sealing portion, a sealing width of about 5 mm is required. In order to reduce the size and space of the fuel cell, it is necessary to make these seal widths as small as possible. Further, it is necessary to sandwich the seal member and the seal portion between the upper and lower separators, and a relatively large tightening force must always be applied. Therefore, a tightening mechanism such as an end plate or a tightening rod has to be large in size and weight. In a method using a sealing material or an O-ring, or a method in which a resin is immersed in the MEA in advance to seal, a member and a process for sealing are required, and further measures are desired for cost reduction. Was. In a polymer electrolyte fuel cell, it is necessary that the electrolyte membrane and the electrode, and the electrode and the separator plate are sufficiently pressed against each other. However, in these methods, the tightening pressure from the end plate is applied to the electrode section and the seal. There is also a problem that it is difficult to control the thickness and shape of these parts in order to apply a sufficient pressure contact force because they act on both parts.

[0009] In the internal manifold type, holes are provided directly in the stacked separator plates and MEAs for the passage of a reaction gas or a cooling medium. As the number of stacked batteries and the power output increase, a large amount of fluid must be supplied and discharged through the internal manifold holes, and the pressure loss in the manifold section increases. Therefore, in the case of a fuel cell with a small number of stacks, it is necessary to use a manifold hole with a small hole diameter in consideration of the compactness of the entire battery, and conversely, in a fuel cell with a large number of stacks, it is necessary to use a manifold hole with a large hole diameter to suppress pressure loss. . In the case of the internal manifold type, there is a problem that the number of laminations must always be considered in the design of the separator and the MEA. In the case of an internal manifold type fuel cell, since a constant tightening pressure is applied to the entire cell, the reliability of the gas seal is generally high. On the other hand, in the case of an external manifold type fuel cell, since the side surface of the laminated cell in contact with the flange surface of the manifold is a laminated body of a thin plate such as an MEA or a separator, it is difficult to obtain a smooth sealing surface. The reliability of the gas seal is lower than that of the gas seal.

[0010]

SUMMARY OF THE INVENTION An object of the present invention is to provide a polymer electrolyte fuel cell which is small and compact and has excellent gas seal reliability.

[0011]

A polymer electrolyte fuel cell according to the present invention has a pair of electrodes sandwiching a polymer electrolyte membrane, supplies fuel such as hydrogen to one electrode surface, and supplies the other electrode. A unit having a unit for supplying an oxidizing gas containing oxygen or the like to the surface is referred to as a unit cell. Then, by stacking a plurality of the unit cells via a conductive separator, a stack of a polymer electrolyte fuel cell is formed. At this time, the ends of the pair of electrodes sandwiching the polymer electrolyte membrane were allowed to reach the side surfaces of the stacked polymer electrolyte fuel cells, and the supply and discharge of gas to each cell were performed by stacking. This is performed through a gas manifold arranged on the side of the polymer electrolyte fuel cell. At this time, the gas manifold is arranged in the longitudinal direction of a battery stack configured by stacking a plurality of unit cells. By arranging in such a position, the supply and discharge of gas to each unit cell can be performed more uniformly.

[0012]

BEST MODE FOR CARRYING OUT THE INVENTION A polymer electrolyte fuel cell according to the present invention comprises a solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer interposed between the solid polymer electrolyte membranes, and one of the electrodes. Means for supplying and distributing a fuel gas containing hydrogen and for supplying and distributing an oxidizing gas containing oxygen to the other, a polymer electrolyte fuel cell in which a plurality of cells are stacked via a conductive separator. There is a gas manifold for supplying and discharging fuel gas and oxidizing gas to the cells,
It is arranged on the side surface of the stacked fuel cells in parallel with the longitudinal direction.

Another polymer electrolyte fuel cell according to the present invention comprises:
A solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer disposed with the solid polymer electrolyte membrane interposed therebetween, and an oxidizing agent which supplies and distributes a fuel gas containing hydrogen to one of the electrodes and contains oxygen to the other. A polymer electrolyte fuel cell in which a plurality of cells each having a unit for supplying and distributing gas are stacked with a conductive separator interposed therebetween, for supplying and discharging fuel gas and oxidizing gas to the cells. Is disposed on the outer periphery of the stacked fuel cells, and has a function of reducing the contact resistance between the cells by mutually tightening the cells. Preferably, the gas manifold is made of an elastic material. As a result, the creep of the thickness of the stacked battery in the stacking direction can be absorbed, and the unevenness on the side surface of the stacked battery in contact with the sealing surface of the external manifold can be absorbed, so that the reliability of the seal of the external manifold can be improved.

[0014] Still another polymer electrolyte fuel cell according to the present invention is a polymer electrolyte fuel cell comprising: a solid polymer electrolyte membrane; a pair of electrodes having a catalytic reaction layer interposed between the solid polymer electrolyte membranes; And a means for supplying and distributing a fuel gas containing oxygen, and a means for supplying and distributing an oxidant gas containing oxygen to the other. A gas manifold for supplying and discharging the fuel gas and the oxidizing gas to the unit cells is disposed on a side of the stacked fuel cells, and has a function of releasing heat due to an electrochemical reaction of the operating unit cells. .

[0015] Further, a means for supplying a fuel such as hydrogen to one electrode surface and supplying an oxidizing gas containing oxygen or the like to the other electrode surface has a pair of electrodes with the polymer electrolyte membrane interposed therebetween. A plurality of cells are stacked via a conductive separator, and gas is supplied to and discharged from each cell through a gas manifold disposed on the side of the stacked polymer electrolyte fuel cell. Batteries,
The gas seal surface of the gas manifold has a flange-like shape, and a ring-shaped frame is fitted to the flange surface, and the gas manifold is sealed by tightening the frame in the battery direction. .

Further, the battery has a pair of electrodes sandwiching the polymer electrolyte membrane, and has means for supplying a fuel such as hydrogen to one electrode surface and supplying an oxidizing gas containing oxygen or the like to the other electrode surface. A polymer electrolyte fuel cell in which a plurality of cells are stacked with a conductive separator interposed therebetween, wherein the electrode ends reach the side surfaces of the stacked polymer electrolyte fuel cell, By covering the side surface of the electrolyte fuel cell with a gas-tight non-conductive material, gas sealing properties of the electrode and the separator are imparted, and gas supply and discharge to each unit cell are performed by using a laminated polymer electrolyte. In a polymer electrolyte fuel cell, which is carried out through a gas manifold disposed on the side of the fuel cell, the external manifold is constructed by using the same material as the gas manifold and the gas-tight non-conductive material. For the material of the side surface of the stacked cell in contact with the sealing surface and the sealing surface of the external manifolds are identical,
The reliability of the seal of the external manifold can be improved without impairing the jointability of the side surfaces of the stacked battery in contact with the external manifold and the seal surface of the external manifold due to the difference in the coefficient of thermal expansion.

Further, the battery has a pair of electrodes sandwiching the polymer electrolyte membrane, and has means for supplying a fuel such as hydrogen to one electrode surface and supplying an oxidizing gas containing oxygen or the like to the other electrode surface. A polymer electrolyte fuel cell in which a plurality of cells are stacked with a conductive separator interposed therebetween, wherein the electrode ends reach the side surfaces of the stacked polymer electrolyte fuel cell, By covering the side surface of the electrolyte fuel cell with a gas-tight non-conductive material, gas sealing properties of the electrode and the separator are imparted, and gas supply and discharge to each unit cell are performed by using a laminated polymer electrolyte. In a polymer electrolyte fuel cell, which is carried out through a gas manifold disposed on the side of the fuel cell, the gas manifold is made of the same material as the gas-tight non-conductive material. A gas battery is installed on the surface covered with the material, and the gas manifold is bonded to the gas-tight non-conductive material to perform gas sealing, so that the stacked surface of the external manifold is in contact with the sealing surface of the external manifold. Since the side surfaces are joined, the reliability of the seal of the outer manifold can be improved.

If ultrasonic welding is used to join the gas manifold and the gas-tight non-conductive material as described above, the sealing surface of the external manifold is joined to the side surface of the stacked battery in contact with the sealing surface of the external manifold. Reliability can be improved. Furthermore, by molding a gas-tight non-conductive material by a method such as injection molding, it is possible to accurately mold the side surface of the laminated battery, and it is possible to improve the reliability of the seal of the external manifold. . Further, there is provided a unit cell having a pair of electrodes sandwiching a polymer electrolyte membrane, having a means for supplying a fuel such as hydrogen to one electrode surface, and a means for supplying an oxidizing gas containing oxygen or the like to the other electrode surface. A polymer electrolyte fuel cell in which a plurality of polymer electrolyte fuel cells are stacked with a conductive separator interposed therebetween, wherein the electrode ends reach the side surfaces of the stacked polymer electrolyte fuel cells, By covering the sides of the battery with a gas-tight non-conductive material, the electrodes and the separator are provided with gas sealing properties, and the supply and discharge of gas to and from each unit cell are performed by stacking a polymer electrolyte fuel cell. In a polymer electrolyte fuel cell, which is performed through a gas manifold disposed on the side of the gas manifold, the gas manifold and the gas-tight non-conductive material are integrally molded by a method such as injection molding to form an external device. Nihorudo and there is no joint surface between the side surface of the stacked cell, it is possible to improve the sealing of the reliability of the external manifold. Furthermore, since the gas-tight non-conductive material is formed of resin or rubber, it is possible to maintain electrical insulation, and when rubber is used, the stacking direction of the stacked battery is reduced. By absorbing the creep of the thickness and the unevenness of the side surface of the laminated battery in contact with the sealing surface of the external manifold, the overall sealing reliability can be improved.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the drawings.

Example 1 A carbon powder having a particle diameter of several microns or less was immersed in an aqueous solution of chloroplatinic acid, and a platinum catalyst was supported on the surface of the carbon powder by a reduction treatment. At this time, the weight ratio of carbon to the supported platinum was 1: 1.
Next, the carbon powder carrying platinum was dispersed in an alcohol solution of a polymer electrolyte to form a slurry. On the other hand, a 400 μm thick carbon paper serving as an electrode is
After impregnating in an aqueous dispersion of a fluororesin (NEOFLON ND-1 manufactured by Daikin Industries, Ltd.), this was dried and subjected to heat treatment at 400 ° C. for 30 minutes to impart water repellency to the carbon paper. Next, a slurry containing carbon powder was uniformly applied to one surface of the water-repellent carbon paper to form a catalytic reaction layer 2, thereby obtaining an electrode 23.

Using the electrode 23 obtained as described above, a battery unit as shown in FIG. 1 was assembled. The obtained electrode 23 was cut into both a length and a width of 10 cm. Then, the two electrodes 23 are formed on both surfaces of a polymer electrolyte membrane 3 whose length and width are both 12 cm larger than the electrodes 23, and the surfaces provided with the catalytic reaction layers 2 are respectively formed on the polymer electrolyte membrane 3. They were superposed so that they faced each other and were located at the center of the polymer electrolyte membrane 3. Electrode 23
A silicon rubber sheet having a thickness of about 350 μm was placed around the polymer electrolyte membrane 3 and hot-pressed at 100 ° C. for 5 minutes to obtain an electrode electrolyte membrane assembly (hereinafter referred to as MEA) 24. . Here, the silicon rubber functions as a gasket for preventing gas supplied to the battery from leaking or mixing with each other.

[0022] A pair of the obtained MEAs 24 is
And superimposed alternately. The separator 4 has a thickness of 4 mm
It is made of carbon and has airtightness. Also the MEA24
A gas flow path 5 having a width of 2 mm and a depth of 1 mm is formed by cutting on the surface to be brought into contact with. Further, a manifold hole 11 for a fuel gas or an oxidizing gas is formed in the periphery of the separator 4 so as to penetrate the front and back surfaces. Note that the manifold hole 11 communicates with an end of the gas flow path 5. Similarly, a manifold hole 12 for circulating cooling water is also formed through the front and back of the separator plate 4. When the MEA 24 is sandwiched between the separator plates 4, a sheet 1 made of polyethylene terephthalate (PET) having the same outer dimensions as the separator plate 4 is provided around the electrodes 23.
3 was placed. This PET sheet 13 was used as a spacer between the separator plate 4 and the polymer electrolyte membrane 3 at the periphery of the MEA 24. Further, the O-ring 7 was not used for sealing the cooling channel 21.

Twenty-five such battery constituent units, ie, 50 cells, are stacked, and a metal current collector plate is provided at each end.
An insulating plate and an end plate were sequentially stacked to obtain a battery stack. Then, the battery stack was fixed by connecting both end plates of the battery stack with fastening rods. The fastening pressure at this time was 10 kgf / cm ² with respect to the area of the separator plate. Although fuel gas and cooling water were passed through the 50-cell battery module, they leaked from the gap between the PET sheet and the separator, and battery performance was not obtained.

Therefore, in the battery of the present embodiment, an attempt was made to arrange the battery in the longitudinal direction of the battery stack, that is, in parallel with the long side of the outer dimension of the battery stack, using the external manifold system instead of the internal manifold system. FIG. 6 shows the entire configuration. The obtained MEA 24 was separated from the separator plate 4 shown in FIG.
a and 4b and between the separator plates 4b and 4c to obtain a battery constituent unit. Separator 4a,
Each of 4b and 4c is made of carbon having a thickness of 4 mm and has airtightness. On the surface thereof, a gas flow path 5 or a cooling flow path 21 is formed. In the drawing, cooling channels 21 are formed on the upper surface of the separator plate 4a and the lower surface of the separator plate 4c, respectively. The supply / discharge port 16 of the cooling channel 21 is open on the side surface of the separator plates 4a and 4c. On the lower surface of the separator 4a, on both surfaces of 4b and on the upper surface of 4c, gas flow paths 5 for flowing a fuel gas or an oxidizing gas are formed. The gas flow path 5
It is formed by cutting and has a width of 2 mm and a depth of 1 mm. The supply and discharge ports 14 and 15 of the fuel gas and oxidant gas gas flow paths 5 also open to the side surfaces of the respective separator plates, similarly to the supply and discharge port 16 of the cooling water. The separators 4a to 4c were not provided with a manifold as in the internal manifold system, and only the gas flow path 5 or the cooling flow path 21 was disposed on the entire surface. The supply port and the discharge port of the gas flow path 5, that is, the pair of supply / discharge ports 14 or 15, were arranged on sides facing each other. In stacking the cells, the hydrogen gas supply / discharge port 14, the air supply / discharge port 15 and the cooling water supply / discharge port 16 were arranged such that the external manifolds were located on the opposite side surfaces.

The configuration of the electrode of this embodiment is such that the carbon paper on which the catalytic reaction layer 2 is formed and the carbon separator have the same outer dimensions without using a PET sheet, and the electrode ends reach the side of the battery during lamination. A battery having the following structure was manufactured. After stacking two unit cells, a battery module in which 50 cells were stacked in a pattern of stacking cooling units was assembled.
No O-ring was used for sealing the cooling section. In addition,
Because of the external manifold system, it was not necessary to provide a fluid supply / discharge port on the current collector, insulating plate and end plate. The fastening rod portion for fastening the battery module was provided on a side different from the side where the gas supply / discharge port was open.
Next, the side surface of the module was covered with a phenol resin as a sealing material. At this time, the gas supply / discharge ports 14 and 1
5 and the supply / discharge port 16 of the cooling water were prevented from being blocked by the sealing material. A phenol resin was applied to the portion of the outer manifold that was in contact with the seal surface so as to obtain a surface as smooth as possible.

Next, as shown in FIG. 6, a semi-cylindrical external manifold 17 made of SUS is supplied from the side of the battery module to a fuel gas supply / discharge port 14, an oxidant gas supply / discharge port 15,
And each row of cooling water supply and discharge ports 16,
The battery stack 25 was arranged so as to be arranged in the longitudinal direction.
The external manifold 17 was fixed with end plate screws 18. The manifold seal 19 between the external manifold 17 and a sealing material covering the side surface of the battery stack 25 is
A gasket is obtained by cutting an EPDM sheet having closed cells into a predetermined outer manifold sealing surface.

A battery test was conducted by passing hydrogen and air through the 50-cell stacked battery and circulating cooling water. Hydrogen utilization 70%, oxygen utilization 20%, hydrogen humidifier bubbler temperature 85
The battery output was 1020 W (30 A-35 V) under the conditions of ° C., oxygen humidified bubbler temperature of 75 ° C., and battery temperature of 75 ° C. Gas leakage from the external manifold seal was also measured, but no leak was detected, indicating good sealing performance. In this embodiment, by adopting a method of arranging a sealing material on the entire side surface of the polymer electrolyte fuel cell, the external manifold method conventionally used in a fuel cell such as a molten carbonate fuel cell can be easily realized. showed that. Also,
With the configuration shown in this embodiment, the manifold section and the battery stack section can be manufactured separately. This makes it possible, for example, to mass-produce battery stacks consisting of separators, electrodes, and electrolytes of the same shape regardless of the fuel cell application and output scale, and manufacture the manifold section according to the application and output scale. And showed that it can contribute to cost reduction.

<< Embodiment 2 >> In this embodiment, a gas manifold 20 which functions in the same manner as the gas manifold of Embodiment 1 is used.
As shown in FIG. 7, the polymer electrolyte fuel cell stack 25
Was arranged on the outer periphery. Thereby, the contact resistance between the cells can be reduced by mutually tightening the cells in the battery stack 25. The configuration of the battery according to the present embodiment is the same as that of the battery according to the first embodiment except for the method of installing the gas manifold. Example 1 A module battery having this configuration was used in Example 1.
As a result of evaluation under the same conditions as in the above, 1200 W (30A-40
V) was obtained. This indicates that the module battery of this example exhibits higher performance than the battery of Example 1 and the battery using a spacer such as a PET sheet. This is because the gas manifold was arranged on the outer periphery of the polymer electrolyte fuel cell stack, and the unit cells were fastened to each other to reduce the contact resistance between the unit cells.

Embodiment 3 In this embodiment, the effect of the gas manifold on the stability of the battery output characteristics when the surrounding environment is changed was evaluated in a battery module having the same configuration as that of Embodiment 2. The battery used in this embodiment is different from the battery used in Embodiment 2 in that the mounting area of the gas manifold 20 shown in FIG. 7 is changed. Further, the material of the gas manifold 20 was changed, and the relationship between the thermal conductivity of the gas manifold and the stability of the battery output was evaluated. FIG. 8 shows the result. In FIG. 8, the vertical axis represents the output power of the battery module, and the horizontal axis represents the operation time. The area indicates the area% of the gas manifold when the side area of the battery module to be attached is 100. In the figure, S
US is the same SUS gas manifold 20 as in Example 2.
And Ni / Cu means copper plated with nickel. For battery performance evaluation, a battery test was performed by passing cooling water through hydrogen and air through the battery module. At this time, the hydrogen utilization rate was 70% and the oxygen utilization rate was 2
The environmental cycle was set to 0%, a hydrogen humidifier bubbler temperature of 85 ° C., an oxygen humidifier bubbler temperature of 75 ° C., and the temperature of the external atmosphere in which the battery module was installed was 5 ° C. for 12 hours and −40 ° C. for 12 hours. In addition, the temperature of the cooling water is synchronized with the temperature of the external atmosphere at 5 ° C for 12 hours and
C. for 12 hours. As a result, in a field test in which the environmental temperature at which the battery module was installed was changed, the longer the area of the gas manifold was, the better the long-term stability was. Further, the material made of copper plated with nickel having excellent thermal conductivity was superior to the material made of SUS. This is due to the fact that the gas manifold radiated heat when the external environment was relatively hot.

[0030]

According to the present invention, the reliability of the seal of the outer manifold can be improved and the assembling process can be simplified. Further, the mechanical strength is increased, and fastening parts such as end plates are simplified, thereby providing long-term stability.

[Brief description of the drawings]

FIG. 1 is a partially cutaway perspective view showing a configuration of a conventional polymer electrolyte fuel cell.

FIG. 2 is a longitudinal sectional view showing an example of a seal portion of a conventional polymer electrolyte fuel cell.

FIG. 3 is a longitudinal sectional view showing another example of a seal portion of a conventional polymer electrolyte fuel cell.

FIG. 4 is a longitudinal sectional view of a seal portion of the polymer electrolyte fuel cell according to one embodiment of the present invention.

FIG. 5 is a perspective view of a separator plate used in the polymer electrolyte fuel cell according to one embodiment of the present invention.

FIG. 6 is a perspective view showing a polymer electrolyte fuel cell of the same example.

FIG. 7 is a perspective view showing a polymer electrolyte fuel cell according to another embodiment of the present invention.

FIG. 8 is a characteristic diagram showing output characteristics of a polymer electrolyte fuel cell according to still another embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Diffusion layer 2 Catalytic reaction layer 3 Polymer electrolyte membrane 4, 4a, 4b, 4c Separator plate 5 Gas flow path 6 Sealing material 7 O-ring 8 Gasket 10 Resin 11 Manifold hole of gas 12 Manifold hole of cooling water 13 Polyethylene terephthalate Sheet 14 Fuel gas supply / discharge port 15 Oxidant gas supply / discharge port 16 Cooling water supply / discharge port 17 External manifold 18 End plate screw 19 Manifold seal 20 Band type manifold 21 Cooling flow path 23 Electrode 24 Electrode electrolyte membrane bonding Body 25 Battery Stack

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Kazuhito Hato, 1006 Kadoma Kadoma, Kadoma City, Osaka Prefecture Inside Matsushita Electric Industrial Co., Ltd. (72) Inventor Makoto Uchida 1006 Kadoma, Kazuma, Osaka Pref. Matsushita Electric Industrial Co., Ltd. (72) Inventor Eiichi Yasumoto 1006 Odaka, Kazuma, Kadoma, Osaka Pref. Yasushi 1006 Kazuma Kadoma, Kadoma City, Osaka Prefecture, Japan Matsushita Electric Industrial Co., Ltd. Address Matsushita Electric Industrial Co., Ltd. F term (reference) 5H026 AA06 CC03

Claims (3)

[Claims] 1. A solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer disposed on both sides of the solid polymer electrolyte membrane, and supplying and distributing a fuel gas containing hydrogen to one of the electrodes; A polymer electrolyte fuel cell in which a plurality of cells each having a unit for supplying and distributing an oxidizing gas containing oxygen are stacked on each other with a conductive separator interposed therebetween, wherein the fuel gas is supplied to the cells. And a polymer electrolyte fuel cell in which a gas manifold for supplying and discharging the oxidant gas is arranged on a side surface of the stacked fuel cell in parallel with a longitudinal direction thereof. 2. A solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer disposed on both sides of the solid polymer electrolyte membrane, and a fuel gas containing hydrogen supplied and distributed to one of the electrodes; A polymer electrolyte fuel cell in which a plurality of cells each having a unit for supplying and distributing an oxidizing gas containing oxygen are stacked on each other with a conductive separator interposed therebetween, wherein the fuel gas is supplied to the cells. And a gas manifold for supplying and discharging the oxidizing gas is disposed on the outer periphery of the stacked fuel cells, and has a function of reducing contact resistance between the cells by tightening the cells together. Molecular electrolyte fuel cell. 3. A solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer disposed on both sides of the solid polymer electrolyte membrane, and supplying and distributing a fuel gas containing hydrogen to one of the electrodes; A polymer electrolyte fuel cell in which a plurality of cells each having a unit for supplying and distributing an oxidizing gas containing oxygen are stacked on each other with a conductive separator interposed therebetween, wherein the fuel gas is supplied to the cells. And a gas manifold for supplying and discharging the oxidizing gas, which is disposed on a side surface of the stacked fuel cell, and has a function of releasing heat due to an electrochemical reaction of the unit cell in operation. battery.