JP5206147B2 - Polymer electrolyte fuel cell - Google Patents

Description

  The present invention relates to a polymer electrolyte fuel cell used for a portable power source, a power source for an electric vehicle, a stationary cogeneration system, and the like.

  A solid polymer fuel cell is one in which a fuel gas such as hydrogen and an oxidizing gas such as air are reacted electrochemically by a gas diffusion electrode, and electricity and heat are generated simultaneously. The basic unit cell structure of such a polymer electrolyte fuel cell is shown in FIG.

  In addition, the side in which the fuel gas such as hydrogen is involved is called an anode, and in the figure, a is added after the symbol, the side in which the oxidizing gas such as air is involved is called the cathode, and in the drawing, c is added after the symbol. .

  In FIG. 8, catalyst reaction layers 32a and 32c mainly composed of carbon powder carrying a platinum-based metal catalyst are disposed in close contact with both surfaces of a polymer electrolyte membrane 31 that selectively transports hydrogen ions. To do.

  Further, a pair of diffusion layers 33a and 33c having both gas permeability and conductivity are disposed in close contact with the outer surfaces of the catalyst reaction layers 32a and 32c. The diffusion layers 33a and 33c and the catalyst reaction layers 32a and 32c constitute electrodes 34a and 34c. The electrode electrolyte assembly 35 (hereinafter referred to as MEA) is formed by the electrodes 34 a and 34 c and the polymer electrolyte membrane 31.

  The MEA 35 is mechanically fixed to the outside of the MEA 35, adjacent MEAs are electrically connected to each other in series, the reaction gas is supplied to the electrodes, and the gas generated by the reaction and excess gas are carried away. Gas separators 36a, 36c for the conductive separators 37a. 37c is arranged. A conductive separator 37c of an adjacent unit cell is in contact with the surface of the conductive separator 37a opposite to the MEA 35.

  A circulating water passage 38 is provided on the side where the conductive separators 37a and 37c contact each other, and the circulating water flows there. The circulating water moves heat so as to adjust the temperature of the MEA 35 through the conductive separators 37a and 37c. MEA gaskets 40a and 40c for sealing gas are provided between the MEA 35 and the conductive separators 37a and 37c, and separator gaskets 41a and 41c for sealing circulating water are provided between the conductive separators 37a and 37c. It has been.

  Next, the basic operation will be described. An oxidizing gas such as air is supplied to the gas flow path 36c, and a fuel gas such as hydrogen is supplied to the gas flow path 36a. Hydrogen in the fuel gas diffuses through the diffusion layer 33a and reaches the catalytic reaction layer 32a. In the catalytic reaction layer 32a, hydrogen is divided into hydrogen ions and electrons. The electrons are moved to the cathode side through an external circuit. The hydrogen ions permeate the membrane 31, move to the cathode side, and reach the reaction catalyst layer 32c. Oxygen in the oxidizing gas such as air diffuses in the diffusion layer 33c and reaches the reaction catalyst layer 32c.

  In the catalyst reaction layer 32c, oxygen reacts with electrons to form oxygen ions, and the oxygen ions react with hydrogen ions to generate water. That is, the oxidizing gas and the fuel gas react around the MEA 35 to generate water, and electrons flow.

  Further, heat is generated during the reaction, and the temperature of the MEA 35 rises. Therefore, the heat generated by the reaction is carried out by water by flowing water or the like through the circulating water path 38. That is, heat and current (electricity) are generated.

Here, the generated electric power is taken out by a pair of current collecting plates 42 arranged at both ends of the cell and supplied to an electric circuit outside the fuel cell. As the current collector plate 42, a metal plate having a good conductivity such as brass or copper is used to improve contact resistance and corrosion resistance so that the resistance is not lost. Then, a plurality of unit cell modules including the cooling unit are stacked in one direction, a pair of end plates are arranged outside the current collector plate 42, and the end plates are fixed with fastening bolts (rods), respectively. A tightening method for tightening the single cell module is employed (for example, see Patent Document 1).

Further, in such a laminated battery, heat radiation from the end portion in the stacking direction is increased, and the cells located at both ends tend to be low temperature. As a result, the end cells are clogged with water and there is a risk of performance degradation. In order to solve such a problem, the cited document discloses a method for preventing the end cell from being lowered in temperature by providing a cooling water channel outside the end cell and suppressing heat dissipation from the end cell.
JP 2002-313386 A

  However, the conventional polymer electrolyte fuel cell has the following problems.

  When the reaction gas or cooling water humidified on the current collector plate is in direct contact with the manifold hole portion, pinholes exist in the surface treatment such as gold plating, and the base material of the current collector plate is corroded. When the current collector plate is corroded, metal ions are eluted in the water and cooling water in the reaction gas, and when supplied to the MEA, the deterioration of the electrolyte membrane and the decrease in ionic conductivity are accelerated, and the performance of the MEA increases. It will cause a drop. Furthermore, when corrosion progresses, the current collector plate surface is deformed, the seal around the manifold hole is broken, and there is a risk of causing a reaction gas or cooling water leak.

  In addition, when the cooling water is arranged between the current collector plate and the end cell as in the previous example, an end separator is provided to avoid direct contact of the cooling water with the current collector plate. In this case, it is necessary to close the cooling water manifold hole of the end separator, so that the cooling water is distributed to the cooling water flow path. There was a problem of becoming difficult.

  The polymer electrolyte fuel cell of the present invention solves the above-mentioned conventional problems, and provides a polymer electrolyte fuel cell that eliminates corrosion of a current collector plate, has excellent durability, and can be produced at low cost. For the purpose.

  In order to solve the above problems, a polymer electrolyte fuel cell of the present invention includes a membrane electrode assembly in which an electrolyte membrane and an electrode are bonded, a separator disposed so as to sandwich the membrane electrode assembly, A pair of end separators disposed so as to sandwich both ends of a laminate including the membrane electrode assembly and the separator, and an electric power generated by the membrane electrode assembly disposed on both outer sides of the pair of end separators The separator and the end separator are provided with a pair of current collector plates for collecting output, and are provided with manifold holes for supplying and discharging reaction gas or cooling water, and at least one of the end separators The manifold hole is sealed.

  As a result, it is possible to prevent the current collector plate from coming into direct contact with the reaction gas or cooling water, and to completely prevent the current collector plate from being corroded, thereby greatly improving the durability of the fuel cell.

  The polymer electrolyte fuel cell of the present invention completely prevents contact between the reaction gas, the cooling water, and the current collector plate by sealing any one of the inlet / outlet manifold holes of the end separator, and is durable It is possible to provide a polymer electrolyte fuel cell with improved performance.

  1st invention clamps the both ends of the membrane electrode assembly which joined the electrolyte membrane and the electrode, the separator arrange | positioned so that a membrane electrode assembly may be clamped, and the laminated body containing a membrane electrode assembly and a separator A pair of end separators, and a pair of current collector plates that are disposed on both outer sides of the pair of end separators and collect the electrical output generated by the membrane electrode assembly, and the separator and the end separator Has a manifold hole for supplying and discharging reaction gas or cooling water, and at least one manifold hole of the end separator is sealed.

  With this configuration, it is possible to completely prevent contact between the reaction gas and cooling water and the current collector plate, and to provide a solid polymer fuel cell having excellent durability.

  In a second aspect based on the first aspect, at least one of the pair of end separators is connected to a manifold hole, and a flow path for supplying and discharging reaction gas or cooling water to and from the laminate is formed. , At least one of the manifold holes on the inlet side or the outlet side connected to the flow path is sealed.

  With this configuration, even when a flow path of a reaction gas or cooling water is configured in the end separator, a solid polymer fuel cell that can completely prevent contact with the current collector plate and has improved durability is provided. be able to.

  According to a third aspect, in the second aspect, the position where the manifold hole is sealed is a position deeper than the flow path depth.

  This configuration prevents contact with the current collector plate and ensures the ability to distribute the reaction gas or cooling water to the flow path configured in the end separator, eliminating the degradation of the end cell performance. A fuel cell can be provided.

  In a fourth aspect based on the third aspect, the cooling water is supplied to the flow path.

  With this configuration, it is possible to provide a high-performance polymer electrolyte fuel cell that prevents a temperature drop of the end cell due to heat dissipation and eliminates a decrease in the performance of the end cell.

  According to a fifth invention, in any one of the first to fourth inventions, the end separator is composed of two or more parts, and the manifold hole is sealed by a sealing member fitted into the manifold hole. It is what.

  With this configuration, it is possible to provide a high-performance polymer electrolyte fuel cell that eliminates the performance degradation of the end cells.

  According to a sixth invention, in the fifth invention, the sealing member is made of resin.

  With this configuration, it is possible to provide a high-performance polymer electrolyte fuel cell that eliminates the performance degradation of the end cells.

  According to a seventh aspect, in the fifth aspect, the sealing member is made of rubber.

  With this configuration, it is possible to provide a high-performance polymer electrolyte fuel cell that eliminates the performance degradation of the end cells.

  In an eighth aspect based on the fifth aspect, the sealing member is an elastomer.

  With this configuration, it is possible to provide a high-performance polymer electrolyte fuel cell that eliminates the performance degradation of the end cells.

Hereinafter, embodiments of the present invention will be described with reference to the drawings, but the present invention is not limited to the embodiments. In addition, about the part same as a prior art example, the same code | symbol is attached | subjected and the description is abbreviate | omitted.
(Embodiment 1)
FIG. 1 is an exploded perspective view of a single cell of a polymer electrolyte fuel cell according to Embodiment 1 of the present invention.

  As shown in FIG. 1, a single cell includes a pair of anode-side separator 107a and cathode-side separator 107c sandwiching a MEA 105 configured by sandwiching a polymer electrolyte membrane 101 provided on a frame 1 with a pair of electrodes 104. It is configured.

  The anode side separator 107a and the cathode side separator 107c are provided with a fuel gas inlet manifold hole 2 for introducing a fuel gas containing hydrogen from the outside, and a fuel gas outlet for discharging a fuel gas not used for power generation to the outside. Manifold hole 3, oxidant gas inlet manifold hole 4 for introducing oxygen-containing oxidant gas from the outside, and oxidant gas outlet manifold hole 5 for discharging oxidant gas not used for power generation to the outside Is provided in the vicinity of the outer periphery of the anode separator 107a and the cathode separator 107c.

  A fuel gas flow path 106 a for connecting the fuel gas inlet manifold hole 2 and the fuel gas outlet manifold hole 3 and supplying fuel gas to the electrode 104 is provided on the surface of the anode separator 107 a that contacts the MEA 105. Yes.

  Similarly, the surface of the cathode separator 107 c that contacts the MEA 105 is connected to the oxidant gas inlet manifold hole 4 and the oxidant gas outlet manifold hole 5, and the oxidant gas flow path 106 c for supplying the oxidant gas to the electrode 104. Is provided. The fuel gas channel 106 a and the oxidant gas channel 106 c are formed by meandering a plurality of channels in order to supply gas to the electrode 104 as uniformly as possible.

  The fuel gas and oxidant gas supplied to the single cell 10 are humidified in order to exert the hydrogen ion conductivity of the polymer electrolyte membrane 101 so that the polymer electrolyte membrane 101 is always kept wet. In order to prevent water vapor in the gas from condensing or water generated during power generation from accumulating in the fuel gas flow channel 106a or the oxidant gas flow channel 106c, the flow channel is blocked and the gas flow is not obstructed. The fuel gas channel 106a and the oxidant gas channel 106c were configured to be introduced and discharged from below.

  In addition, the anode side separator 107a and the cathode side separator 107c have circulating water for removing heat generated along with power generation in a cooling water flow path 8 formed on a surface opposite to the surface in contact with the MEA 105 of the cathode side separator 107c. A cooling water inlet manifold hole 6 and a cooling water outlet manifold hole 7 for introducing and discharging are provided in the vicinity of the outer periphery.

  FIG. 1 shows a state in which the cooling water inlet manifold hole 6 and the cooling water flow path 8 are formed in the end separator 108, but the cooling water inlet manifold hole 6 is sealed by the sealing portion 11. Yes. Further, the cooling water flow path 8 formed in the end separator 108 is configured to prevent leakage by the cooling water seal 9.

  That is, the anode-side separator 107a and the cathode-side separator 107c have an electrode facing region facing the electrode 104 and an annular outer edge region surrounding the electrode facing region, and the outer edge region reacts with the membrane electrode assembly (MEA 105). A manifold hole for supplying and discharging gas or cooling water is formed.

  Further, the MEA 105 is provided with holes at positions corresponding to the manifold holes, on the anode electrode (surface (not shown) side of the electrode 104 in contact with the anode-side separator 107a) side of the MEA 105, outside the anode electrode. Is provided with an MEA gasket (not shown) which is a seal portion in consideration of preventing the fuel gas from leaking to the outside and preventing the oxidant gas and the circulating water from entering this surface.

  Similarly, on the cathode electrode 104c (surface of the electrode 104 on the side in contact with the cathode separator 107c) side of the MEA 105, oxidant gas does not leak outside the cathode electrode 104c, and fuel gas and circulating water are on this surface. An MEA gasket 109 is provided so as not to enter.

  The MEA gasket 109 also plays a role of insulation so that the conductive anode-side separator 107a and the cathode-side separator 107c are in direct contact with each other so as not to be short-circuited. In addition, even if an insulator is inserted in addition to the MEA gasket 109, it is sufficient that sealing can be performed.

  FIG. 2 is a side view showing a configuration of a polymer electrolyte fuel cell configured by stacking the unit cells shown in FIG.

  As shown in FIG. 2, the polymer electrolyte fuel cell of the first embodiment forms a laminate 100 by laminating a plurality of unit cells including the MEA 105, the anode side separator 107a and the cathode side separator 107c. End separators 108 are disposed at both ends of 100, and current collector plates 21, which are gold-plated on brass that is electrically connected to the end separators 108, are disposed outside and sandwiched between a pair of end plates 22. is there. Hereinafter, a configuration in which the single cells are stacked and sandwiched between the pair of end plates 22 is referred to as a stack.

  The unit cell stacking is performed by electrically connecting the anode side separator 107a constituting the unit cell and the cathode side separator 107c constituting the adjacent unit cell, and from the circulating water channel formed in the cathode side separator 107c. A separator gasket (not shown) is provided around the manifold so as to prevent water from leaking to the outside and to prevent fuel gas and oxidant gas from entering this surface.

  Here, in this Embodiment 1, although polyphenyl sulfide (PPS) was used as the end plate 22, even if it is other resin, if it has sufficient intensity | strength with respect to a fastening pressure, it can be used.

In any one of the end plates 22, an oxidant gas inlet pipe 51 for supplying oxidant gas, fuel gas, and cooling water to the stack, a cooling water inlet pipe 52, a fuel gas inlet pipe 53, and a fuel for discharge. A gas outlet pipe 54, a cooling water outlet pipe 55, and an oxidant gas outlet pipe 56 are configured. The corresponding oxidant gas inlet manifold hole 4, fuel gas inlet manifold hole 2, cooling, each of which is configured as a separator. The water inlet manifold hole 6, the oxidant gas outlet manifold hole 5, the fuel gas outlet manifold hole 3, and the cooling water outlet manifold hole 7 are connected.

  Further, a flow path for circulating cooling water is formed between the end separator 108, the anode side separator 107a, and the cathode side separator 107c so as to suppress a temperature drop of the end separator 108 due to heat radiation. .

  The operation and action of the polymer electrolyte fuel cell configured as described above will be described below.

  The fuel gas supplied to the stack from the fuel gas inlet pipe 53 is supplied to the anode side of the electrode 104 through the fuel gas inlet manifold hole 2 and the fuel gas passage 106a of the anode side separator 107a of each unit cell.

  On the other hand, the oxidant gas supplied to the stack from the oxidant gas inlet pipe 51 passes through the oxidant gas flow path 106c of the cathode side separator 107c of each unit cell via the oxidant gas inlet manifold hole 4 to the electrode 104. Supplyed to the cathode side, hydrogen in the fuel gas and oxygen in the oxidant gas cause an electrochemical reaction to generate electricity and heat.

  The heat generated as a result of power generation supplies cooling water from the cooling water inlet pipe 52 via the cooling water inlet manifold hole 6 to the cooling water flow path of the anode side separator 107a, and the cooling water via the cooling water outlet manifold hole 7. By discharging it out of the stack from the outlet pipe 55, it is carried out via the anode side separator 107a and the cathode side separator 107c.

  Next, FIG. 3 shows a plan view of the end separator. The end separator 108 is provided with an inlet manifold for supplying fuel gas, oxidant gas, and cooling water to the laminated body at the periphery. Here, on the end separator 108, the fuel gas inlet manifold hole 2, the oxidant gas inlet manifold hole 4 and the cooling water inlet manifold hole 6 are formed so as to penetrate therethrough, but the fuel gas outlet manifold hole 3 The positions corresponding to the oxidant gas outlet manifold hole 5 and the cooling water outlet manifold hole 7 have no holes and are completely sealed.

  Thereby, it is possible to completely prevent the fuel gas, the oxidant gas and the cooling water from coming into contact with the current collector plate 21 and prevent the current collector plate 21 from being corroded. As a result, the MEA 105 can be prevented from deteriorating due to elution of metal ions, and a solid polymer fuel cell having excellent durability can be supplied.

  In the first embodiment, the fuel gas outlet manifold hole 3, the oxidant gas outlet manifold hole 5 and the cooling water outlet manifold hole 7 are sealed. However, the end portion shown in the first embodiment is shown. In the other end separator 108 facing the separator 108, the fuel gas inlet manifold hole 2, the oxidant gas inlet manifold hole 4, and the cooling water inlet manifold hole 6 are sealed.

In the first embodiment, all the gases and cooling water flow from the same end separator 108 side. However, the inflow direction of the gas and cooling water is changed for each gas type and cooling water. The same effect can be obtained. Furthermore, supply and discharge of fuel gas, oxidant gas, and cooling water to the outside of the stack and to the stack stack are performed using normal piping, and this piping supplies the current collector plate 21, fuel gas, oxidant gas, and cooling water. Plays the role of sequestration.
(Embodiment 2)
Next, FIG. 4 shows a plan view of the end separator 108 according to the second embodiment of the present invention.

  The end separator 108 has a fuel gas inlet manifold hole 2, an oxidant gas inlet manifold hole 4, and a cooling water inlet manifold hole 6 inlet manifold for supplying fuel gas, oxidant gas, and cooling water to the laminate at the periphery. Is provided. Further, a cooling water flow path 8 is formed on the surface for circulating the cooling water.

  Here, there is no hole at the position corresponding to the fuel gas outlet manifold hole 3 and the oxidant gas outlet manifold hole 5 on the end separator 108, and it has a completely sealed shape. As a result, it is possible to completely prevent the fuel gas and the oxidant gas from coming into contact with the current collector plate 21 and prevent the current collector plate 21 from being corroded.

  Further, FIG. 5 shows a cross-sectional view of the coolant outlet manifold hole 7 portion of the end separator 108. Here, the cooling water outlet manifold hole 7 is sealed at a position dug to the same depth as the cooling water flow path 8. With such a shape, it is possible to supply the cooling water to the cooling water flow path 8 and at the same time to seal the cooling water outlet manifold hole 7 and completely prevent the current collector plate 21 from being corroded.

  In the second embodiment, an example in which the cooling water flow path 8 is configured has been described. However, by configuring the cooling water flow path 8 in the end separator 108, it is possible to prevent the end cell from being lowered in temperature due to heat dissipation. It becomes possible to suppress the wetting of the end cells.

  In the second embodiment, the cooling water outlet manifold hole 7 is sealed. However, in the other end separator 108 facing the end separator 108 shown in the second embodiment, the cooling water inlet is used. The manifold hole 6 is sealed.

  In the second embodiment, all the gases and cooling water flow from the same end separator 108 side. However, the inflow direction of the gas and cooling water is changed for each gas type and cooling water. The same effect can be obtained.

Furthermore, supply and discharge of fuel gas, oxidant gas, and cooling water to the outside of the stack and to the stack stack are performed using normal piping, and this piping supplies the current collector plate 21, fuel gas, oxidant gas, and cooling water. Plays the role of sequestration.
(Embodiment 3)
FIG. 6 is a cross-sectional view of the coolant outlet manifold hole 7 portion of the end separator 108 according to the third embodiment of the present invention. Here, the cooling water outlet manifold hole 7 is sealed at a position dug deeper than the cooling water flow path.

By adopting such a shape, the cooling water flowing from above in FIG. 6 is smoothly supplied to the cooling water flow path 8 without being affected by the vortex generated by colliding with the sealing portion. It becomes possible. Thereby, it is possible to completely prevent the cooling water from coming into contact with the current collecting plate 21 and to prevent the current collecting plate 21 from being corroded while ensuring the equal distribution of the cooling water.
(Embodiment 4)
FIG. 7 is a cross-sectional view of the coolant outlet manifold hole 7 portion of the end separator 108 according to the fourth embodiment of the present invention. The cooling water outlet manifold hole 7 includes a sealing member 12 that is a separate member from the end separator 108, and the cooling water outlet manifold hole 7 is sealed by fitting the sealing member 12 into the cooling water outlet manifold hole 7. doing.

  Resin, rubber, and elastomer are used for the sealing member 12. Examples of the resin include PPS (polyphenyl sulfide), PP (polypropylene), and SPS (syndiotack polystyrene). Examples of the rubber include fluorine rubber, silicone rubber, and EPDM rubber. Examples of the elastomer include fluorine elastomer and olefin. Although an elastomer etc. can be used, not only these but selection is possible.

  By adopting such a structure, the degree of freedom of the sealing structure can be improved, gas and cooling water can be prevented from coming into contact with the current collector plate 21 more easily, and the current collector plate 21 can be corroded. Can be prevented.

  As described above, the polymer electrolyte fuel cell according to the present invention can be applied to uses such as a portable power source, a power source for an electric vehicle, and a stationary cogeneration system.

1 is an exploded perspective view of a unit cell constituting a polymer electrolyte fuel cell according to Embodiment 1 of the present invention. Side view showing the configuration of the polymer electrolyte fuel cell Plan view of the end separator of the polymer electrolyte fuel cell The top view of the edge part separator of the polymer electrolyte fuel cell in Embodiment 2 of this invention Sectional view of the cooling water inlet manifold hole portion of the end separator of the polymer electrolyte fuel cell Sectional drawing of the cooling water inlet manifold hole part of the edge part separator of the polymer electrolyte fuel cell in Embodiment 3 of this invention Sectional drawing of the cooling water inlet manifold hole part of the edge part separator of the polymer electrolyte fuel cell in Embodiment 4 of this invention Sectional view of the main part of a conventional polymer electrolyte fuel cell

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Frame 2 Fuel gas inlet manifold hole 3 Fuel gas outlet manifold hole 4 Oxidant gas inlet manifold hole 5 Oxidant gas outlet manifold hole 6 Cooling water inlet manifold hole 7 Cooling water outlet manifold hole 8 Cooling water flow path 9 Cooling water seal 10 Single cell 11 Sealing part 12 Sealing member 21 Current collector plate 22 End plate 51 Oxidant gas inlet pipe 52 Cooling water inlet pipe 53 Fuel gas inlet pipe 54 Fuel gas outlet pipe 55 Cooling water outlet pipe 56 Oxidant gas outlet pipe 101 Polymer electrolyte membrane 104 electrode 104c cathode electrode 105 MEA
106a Fuel gas flow path 106c Oxidant gas flow path 107a Anode side separator 107c Cathode side separator 108 End separator 109 MEA gasket

Claims (7)

A membrane electrode assembly in which an electrolyte membrane and an electrode are joined, a separator disposed so as to sandwich the membrane electrode assembly, and a both ends of a laminate including the membrane electrode assembly and the separator are disposed. A pair of current separators disposed on both outer sides of the pair of end separators and collecting the electrical output generated by the membrane electrode assembly, the separator and the end portions The separator has manifold holes for supplying and discharging reaction gas or cooling water.
At least one of the pair of end separators is connected to the manifold hole, and a flow path for supplying and discharging reaction gas or cooling water to and from the laminate is formed.
At least one of the inlet or outlet manifold holes connected to the flow path is sealed at one end at a position deeper than the flow path depth. battery. The one end part of the said manifold hole is sealed in the position deeper than the said flow path depth so that the influence of the vortex which generate | occur | produces in the sealing part of the said manifold hole may be suppressed. Solid polymer fuel cell. The solid polymer fuel cell according to claim 1 or 2, wherein cooling water is supplied to the flow path. The said edge part separator is comprised by 2 or more types of components, and the said manifold hole is sealed with the sealing member fitted to the said manifold hole, The any one of Claims 1-3 characterized by the above-mentioned. 2. A polymer electrolyte fuel cell according to item 1. 5. The polymer electrolyte fuel cell according to claim 4 , wherein the sealing member is a resin. 5. The polymer electrolyte fuel cell according to claim 4 , wherein the sealing member is rubber. 5. The polymer electrolyte fuel cell according to claim 4 , wherein the sealing member is an elastomer.