JP3580525B2 - Polymer electrolyte fuel cell - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a fuel cell used in a portable power supply, a power supply for an electric vehicle, a cogeneration system in a home, and the like, particularly to a polymer electrolyte fuel cell, and more particularly, to a structure of a manifold of an external manifold fuel cell. Regarding improvement.
[0002]
[Prior art]
A polymer electrolyte fuel cell generates electricity and heat simultaneously by electrochemically reacting a fuel gas such as hydrogen and an oxidizing gas containing oxygen such as air at a gas diffusion electrode. is there.
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 arranged 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 closely arranged. An electrode 23 is constituted by the catalyst reaction layer 2 and the diffusion layer 1. The electrode 23 and the polymer electrolyte membrane 3 are integrated in advance to form an electrode electrolyte membrane assembly (hereinafter referred to as MEA) 24.
[0003]
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 electrode 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. The gasket 8 is made of, for example, a resin or a metal plate, has a thickness similar to that of the electrode 23, and the gap between the separator plate 4 and the gasket 8 that are arranged to face each other is sealed with grease or an adhesive.
In recent years, as shown in FIG. 4, as the MEA 24, a resin 10 having a sealing effect is previously impregnated into a portion requiring gas sealing properties, and is solidified to form a gas seal between the MEA 24 and the separator plate 4. A method for ensuring performance has also been proposed.
[0004]
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 in contact with the MEA 24. Although the gas flow path 5 can be provided separately from the separator plate 4, a gas flow path 5 is generally formed by providing a groove on the surface of the separator plate 4 as shown in FIG.
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 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 the internal manifold type, a through hole is provided in a separator plate in which a gas flow path is formed, an inlet / outlet of the gas flow path is passed to this hole, and a fuel gas or the like is supplied directly from this hole.
[0005]
Among them, a so-called internal manifold type in which a supply / discharge hole for fuel gas or cooling water is secured inside the stacked battery is generally used. However, when the cell is operated using the actual gas obtained by reforming the city gas and hydrogenating, the electrode is poisoned by CO as a result of the increase in the CO concentration in the downstream region of the fuel gas flow path. As a result, the temperature decreases, and the decrease in 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.
[0006]
Regardless of whether the internal manifold type or the external manifold type is used, 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 fixed with a fastening rod. It is necessary to. As for the tightening method, it is desirable that the unit cells be tightened as uniformly as possible in 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, and have a structure in which current does not leak outside through the end plate. As for the fastening rod, a method of passing through a through hole inside the separator plate and a method of fastening the entire lamination pond with a metal belt over an end plate have been proposed.
[0007]
Also, in any of the sealing methods shown in FIGS. 2, 3 and 4, a constant tightening pressure is required to maintain the sealing property and keep the contact resistance between the electrode and the separator plate or between the separator plates small. It is. Therefore, a configuration is adopted in which a screw spring or a disc spring is inserted between the fastening rod and the end plate. This tightening pressure ensures electrical contact between components of the battery, such as the separator plate, electrodes, and electrolyte membrane.
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. The cooling plate generally 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.
[0008]
In the configuration of the fuel cell described above, it is necessary to dispose a sealing material and an O-ring around the electrode in order to seal a gas such as hydrogen gas or air. At this time, the MEA requires a margin of about 10 mm for installing the sealant. Further, even in a method in which a resin having a sealing effect is immersed in 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 material and the seal portion between the upper and lower separators, and a relatively large tightening force must always be applied. Therefore, the tightening mechanism such as the end plate and the tightening rod must 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 a MEA in advance to seal, a member and a step for sealing are required, and further measures are desired for cost reduction. Was. Further, 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, but in these methods, the tightening pressure from the end plate is applied to the electrode portion 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, the stacked separator plates and MEAs are directly provided with holes through which a reaction gas and a cooling medium pass. 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 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 whole cell, 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]
[Problems to be solved by the invention]
An object of the present invention is to provide a polymer electrolyte fuel cell that is small and compact and has excellent gas seal reliability.
[0011]
[Means for Solving the Problems]
The polymer electrolyte fuel cell of the present invention has a pair of electrodes sandwiching a polymer electrolyte membrane, supplies fuel such as hydrogen to one electrode surface, and oxidant gas containing oxygen or the like to the other electrode surface. Is a unit cell having a means for supplying the same. 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 disposed on the side of the polymer electrolyte fuel cell.
At this time, the gas manifold is arranged in a 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
High molecular electrolyte fuel cell of the present invention includes a solid polymer electrolyte membrane, a pair of electrodes having a catalytic reaction layer disposed to sandwich the solid polymer electrolyte membrane, a fuel gas containing hydrogen to one electrode A polymer electrolyte fuel cell in which a plurality of cells having supply and distribution means and a means for supplying and distributing an oxidizing gas containing oxygen to the other are stacked with a plurality of cells interposed therebetween via a conductive separator, A gas manifold for supplying and discharging the fuel gas and the oxidizing gas is arranged 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 of 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.
[0013]
Further, a unit cell having a pair of electrodes with a polymer electrolyte membrane interposed therebetween, 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 is known. A polymer electrolyte fuel cell in which a plurality of cells are stacked via a conductive separator, and gas is supplied to and discharged from each unit cell through a gas manifold disposed on the side of the stacked polymer electrolyte fuel cell. 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. And
[0014]
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 the polymer electrolyte fuel cell, which is performed through the gas manifold disposed on the side surface of the gas manifold, the gas manifold and the gas-tight non-conductive material are made of the same material, so that the sealing surface of the external manifold can be improved. Since the material of the side surface of the stacked battery in contact with the sealing surface of the outer manifold is the same, the external manifold due to the difference in the coefficient of thermal expansion and the joining property of the side surface of the stacked battery in contact with the sealing surface of the outer manifold are not impaired. The reliability of the seal can be improved.
[0015]
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 that is performed through a gas manifold disposed on the side of the gas, the gas manifold is made of the same material as the gas-tight non-conductive material, and is covered with the gas-tight non-conductive material. A gas manifold is installed on the surface, and the gas manifold and the gas-tight non-conductive material are joined to perform gas sealing, thereby joining the outer manifold sealing surface and the side surface of the stacked battery in contact with the outer manifold sealing surface. Therefore, the reliability of the seal of the external manifold can be improved.
[0016]
When ultrasonic welding is used to join the gas manifold and the gas-tight non-conductive material as described above, the external manifold seal surface is joined to the side surface of the laminated battery in contact therewith, so the external manifold seal reliability is reduced. 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 with a polymer electrolyte membrane interposed therebetween, 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 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 formed by injection molding or the like 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 the electrical insulation property, and at the same time, when rubber is used, the stacking direction of the stacked battery is reduced. By absorbing the creep of the thickness and the unevenness on the side surface of the laminated battery in contact with the sealing surface of the external manifold, the overall sealing reliability can be improved.
[0017]
【Example】
Hereinafter, reference examples and preferred embodiments of the present invention will be described in detail with reference to the drawings.
[0018]
<< Reference Example 1 >>
A carbon powder having a particle size of several microns or less was immersed in an aqueous chloroplatinic acid solution, 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, carbon paper having a thickness of 400 μm serving as an electrode is impregnated with an aqueous dispersion of a fluororesin (NEOFLON ND-1 manufactured by Daikin Industries, Ltd.), which is then dried and heat-treated at 400 ° C. for 30 minutes. This imparted water repellency to the carbon paper. Next, a slurry containing carbon powder was uniformly applied to one side of the water-repellent carbon paper to form the catalyst layer 2, and the electrode 23 was obtained.
[0019]
Using the electrode 23 obtained as described above, a battery constituent unit as shown in FIG. 1 was assembled.
The obtained electrode 23 was cut into both a length and a width of 10 cm. Next, the two electrodes 23 are arranged on both surfaces of the polymer electrolyte membrane 3 having a length and width both larger than the electrodes 23 and both being 12 cm, and the surfaces provided with the catalyst layers 2 face the polymer electrolyte membrane 3 respectively. Then, they were superposed so as to be located at the center of the polymer electrolyte membrane 3. A sheet of silicon rubber having a thickness of about 350 μm is placed around the electrode 23 with the polymer electrolyte membrane 3 interposed therebetween, and hot pressed at 100 ° C. for 5 minutes to form an electrode electrolyte membrane assembly (hereinafter referred to as MEA) 24. Obtained. Here, the silicon rubber functions as a gasket for preventing gas supplied to the battery from leaking or mixing with each other.
[0020]
A pair of the obtained MEAs 24 was alternately overlapped with the separator 4. The separator 4 is made of carbon having a thickness of 4 mm and has airtightness. In addition, a gas channel 5 having a width of 2 mm and a depth of 1 mm is formed on the surface to be brought into contact with the MEA 24 by cutting. Further, a manifold hole 11 for a fuel gas or an oxidizing gas is formed in the peripheral portion 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 was sandwiched between the separator plates 4, a polyethylene terephthalate (PET) sheet 13 having the same outer dimensions as the separator plates 4 was arranged around the electrodes 23. 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.
[0021]
A battery stack was obtained by stacking 25 such battery constituent units, that is, 50 cells, and stacking a metal current collector plate, an insulating plate, and an end plate on both ends in this order. Next, 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.
[0022]
Therefore, in the battery of the present reference example, instead of the internal manifold type, an external manifold type was used, and a method of arranging the batteries in the longitudinal direction of the battery stack, that is, in parallel with the long side of the outer dimension of the stack was tried. FIG. 6 shows the overall configuration.
The obtained MEA 24 was sandwiched between the separator plates 4a and 4b and between the separator plates 4b and 4c shown in FIG. 5 to obtain a battery constituent unit.
Each of the separators 4a, 4b and 4c is made of carbon having a thickness of 4 mm and has airtightness. Further, the gas flow path 5 or the cooling flow path 21 is formed on the surface.
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 is formed by cutting, and has a width of 2 mm and a depth of 1 mm. The supply outlets 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 outlet 16 of the cooling water. The separators 4a to 4c were not provided with a manifold such as the internal manifold type, 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 the supply and discharge ports 14 or 15, were arranged on the sides facing each other. When 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.
[0023]
The configuration of the electrode according to the present embodiment has a structure in which 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 surfaces of the battery during lamination. A battery was manufactured. After laminating two single cells, a battery module having 50 cells laminated in a pattern of laminating cooling units was assembled. No O-ring was used to seal 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 plate, the insulating plate, and the 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 15 and the cooling water supply / discharge port 16 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 sealing surface so as to obtain as smooth a surface as possible.
[0024]
Next, as shown in FIG. 6, a SUS semi-cylindrical external manifold 17 is connected to the fuel gas supply / discharge port 14, the oxidant gas supply / discharge port 15, and the cooling water supply / discharge port 16 from the side of the battery module. Each row was covered so as to be arranged in the longitudinal direction of the battery stack 25. The external manifold 17 was fixed with an end plate screw 18. The manifold seal 19 between the outer manifold 17 and the sealing material covering the side surface of the battery stack 25 is a gasket obtained by cutting an EPDM sheet having closed cells into a predetermined shape of the outer manifold seal surface. is there.
[0025]
A battery test was performed by circulating cooling water through hydrogen and air through the 50-cell stacked battery. The battery output under the conditions of a hydrogen utilization rate of 70%, an oxygen utilization rate of 20%, a hydrogen humidifier bubbler temperature of 85 ° C., an oxygen humidifier bubbler temperature of 75 ° C., and a battery temperature of 75 ° C. was 1020 W (30 A-35 V). Gas leakage from the external manifold seal was also measured, but no leak was detected, indicating good sealing performance.
In this reference example, 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, taking the structure described in this reference example, it is possible to manufacture the manifold portion and the cell stack section 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.
[0026]
<< Example 1 >>
In the present embodiment, the gas manifold 20 that functions in the same manner as the gas manifold of Reference Example 1 was arranged on the outer periphery of the polymer electrolyte fuel cell stack 25 as shown in FIG. 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 of this embodiment is the same as that of the battery of Reference Example 1 except for the method of installing the gas manifold.
As a result of evaluating the module battery having this configuration under the same conditions as in Reference Example 1, an output of 1200 W (30 A to 40 V) was obtained. This indicates that the module battery of the present example shows higher performance than the battery of Reference Example 1 and the battery using a spacer such as a PET sheet. The reason for this is that the contact resistance between the cells can be reduced by arranging the gas manifold on the outer periphery of the polymer electrolyte fuel cell stack and tightening the cells together.
[0027]
<< Reference Example 2 >>
In the present reference example, the effect of the gas manifold on the stability of the battery output characteristics when the surrounding environment is changed was evaluated in the battery module having the same configuration as that of the first embodiment.
The battery used in the present reference example is different from the battery used in the first embodiment in that the mounting area of the gas manifold 20 shown in FIG. 7 is changed. The relationship between the thermal conductivity of the gas manifold and the stability of the battery output was evaluated by changing the material of the gas manifold 20. 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 drawing, SUS uses the same SUS gas manifold 20 as in the first embodiment, and Ni / Cu uses copper plated with nickel. The battery performance was evaluated by passing hydrogen and air through the battery module and circulating cooling water. At this time, the hydrogen utilization rate was 70%, the oxygen utilization rate was 20%, the hydrogen humidification bubbler temperature was 85 ° C., the oxygen humidification bubbler temperature was 75 ° C., and the temperature of the external atmosphere where the battery module was installed was 5 ° C. for 12 hours at −40 ° C. The environment cycle was set to 12 hours. The temperature of the cooling water was set at 5 ° C. for 12 hours and at −25 ° C. for 12 hours in synchronization with the temperature of the external atmosphere.
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. Also, the material made of copper plated with nickel, which has 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.
[0028]
【The invention's effect】
According to the present invention, the reliability of the seal of the external manifold can be improved, and the assembling process can be simplified. Further, the mechanical strength is increased, and the fastening parts such as end plates are simplified, thereby providing long-term stability.
[0029]
[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 a polymer electrolyte fuel cell according to Reference Examples and Examples of the present invention.
FIG. 6 is a perspective view showing a polymer electrolyte fuel cell according to a reference example and an example of the present invention .
FIG. 7 is a perspective view showing a polymer electrolyte fuel cell according to a reference example and an example of the present invention.
FIG. 8 is a characteristic diagram showing output characteristics of a polymer electrolyte fuel cell according to a reference example 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 Seal material 7 O-ring 8 Gasket 10 Resin 11 Gas manifold hole 12 Cooling water manifold hole 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 channel 23 Electrode 24 Electrode electrolyte membrane bonding Body 25 Battery stack

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 and containing oxygen to the other A polymer electrolyte fuel cell in which a plurality of cells having means for supplying and distributing an oxidizing gas are stacked via a conductive separator, wherein the fuel gas and the oxidizing gas are supplied to the cells. A polymer electrolyte fuel cell having a gas manifold for supplying and discharging fuel cells, which is arranged on the outer periphery of the stacked fuel cells and has a function of reducing the contact resistance between the cells by tightening the cells together. .

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