JP2012195128A - Gasket for polymer electrolyte fuel cell and polymer electrolyte fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a gasket for polymer electrolyte fuel cell of multiple seal structure in which low fastening power, compaction of a stack, and enhancement in durability of a seal lip are achieved.SOLUTION: The seal member 14 molded on the outer periphery of an MEA 9 integrally therewith is provided continuously with seal lips having sealability in a plane in parallel with each other. One of two rows of seal lips 15, 16 is arranged to have a lower seal height when compared with the other. The height at a part between the seal lips is made lower than the height of fastening the seal lips by means of the separators on the front and back sides of the MEA.

Description

  The present invention relates to a fuel cell used for a portable power source, a power source for an electric vehicle, a domestic cogeneration system, or the like, and more particularly to a gasket for a polymer electrolyte fuel cell using a polymer electrolyte and a polymer electrolyte fuel cell. .

  A fuel cell using a polymer electrolyte generates electric power and heat simultaneously by electrochemically reacting a fuel gas containing hydrogen and an oxidant gas containing oxygen such as air. This fuel cell basically includes a polymer electrolyte membrane that selectively transports hydrogen ions, and a pair of electrodes formed on both sides of the polymer electrolyte membrane, that is, an anode and a cathode. These electrodes are mainly composed of carbon powder supporting a platinum group metal catalyst, and have both a gas permeability and an electronic conductivity disposed on the outer surface of the catalyst layer formed on the surface of the polymer electrolyte membrane and the catalyst layer. It has a gas diffusion layer. An assembly in which the polymer electrolyte membrane and the electrode (including the gas diffusion layer) are integrally joined together is called an electrolyte membrane electrode assembly (hereinafter referred to as “MEA”).

  In addition, on both sides of the MEA, conductive separators for mechanically sandwiching and fixing the MEAs and electrically connecting adjacent MEAs to each other in series are disposed. In each separator, a gas flow path for supplying a reaction gas such as a fuel gas or an oxidant gas to each electrode and carrying away generated water or surplus gas is formed at a portion in contact with the MEA. Such a gas flow path can be provided separately from the separator, but a system in which a groove is provided on the surface of the separator to form a gas flow path is generally used. A structure in which the MEA is sandwiched between the pair of separators is referred to as a “single cell module”.

  The supply of the reaction gas to the gas flow path formed between each separator and the MEA, the reaction gas from the gas flow path, and the discharge of the generated water are performed at the edge of at least one separator of the pair of separators. This is done by providing through holes called manifold holes, communicating the inlets and outlets of the respective gas flow paths with these manifold holes, and distributing the reaction gas from each manifold hole to each gas flow path.

  Further, in order to prevent the fuel gas or oxidant gas supplied to the gas flow path from leaking to the outside or mixing the two kinds of gases with each other, the portion where the electrodes in the MEA are formed, that is, the power generation region A gas sealant or a gasket is disposed as a seal member between the pair of separators so as to surround the outer periphery. These gas seals or gaskets also provide a seal around each manifold hole.

  Since the fuel cell generates heat during operation, it is necessary to cool the fuel cell with cooling water or the like in order to maintain the battery in a favorable temperature state. Usually, a cooling unit for flowing cooling water is provided for every 1 to 3 cells. These MEAs, separators, and cooling units are alternately stacked, and after stacking 10 to 200 cells, an end plate is disposed on each end of these cells via a current collector plate and an insulating plate. These cells are sandwiched between end plates and fixed from both ends with fastening bolts (rods) or the like in a general laminated battery (fuel cell stack) structure. As for the fastening method, a method of passing through a through hole formed in the edge of each separator and fastening with a fastening bolt, or a method of fastening the whole laminated battery with a metal belt over an end plate is common.

  In such a stacked battery, it is important that the unit cell module is fastened with a uniform fastening force in a plane (in a plane orthogonal to the stacking direction) and sealed securely. In recent years, in order to ensure safety, a double seal capable of reliably separating combustible gas and outside air is required. However, miniaturization and space saving of the stack are also required for cost reduction. When double seal is required, the fastening load increases, the fastening member becomes complicated, and the stack volume increases. Since it is common to do this, it conflicts with the requirements for the double seal and the miniaturization and low fastening force of the stack.

  With regard to such a seal for a fuel cell, as shown in FIG. 6 which is a cross-sectional view of a conventional seal described in Patent Document 1, it is excellent in reducing the thickness of the seal portion, improving assemblage, preventing misalignment, and the like. In view of the above, a gasket has been devised in which the lip 201 is composed of two parts, a primary lip 206 and a secondary lip 207, to ensure sealing performance.

  Further, in Patent Document 2, as an example of a gasket that has a good sealing property, can keep the reaction force low, and can prevent the gasket from collapsing, an annular inner peripheral flange 311 and an annular ring shown in FIG. The gasket 303 which consists of the cyclic | annular seal | sticker part connected with the outer periphery both side collar part 312 is proposed.

JP 2004-360717 A JP 2007-335093 A

  However, in the above-described conventional configuration, when a double seal of combustible gas and outside air is required for safety assurance, any of the above-described gaskets for fuel cells can reduce the size and space of the stack. It is not intended to solve a plurality of problems such as low fastening pressure, strength that can withstand the pressure of the fluid to be sealed, that is, maintaining the sealing property, and maintaining the corrosion resistance of the seal.

  Specifically, in Patent Document 1, the sealing performance is low because the lip is too small to maintain a reliable sealing performance in double, and in Patent Document 2, the sealing is performed when the double sealing is simply performed. Since the area required for the process increases, the stack volume and the fastening pressure increase. Moreover, if the stress generated in the seal in contact with the combustible gas is large, the corrosion resistance is lowered.

  Accordingly, an object of the present invention is to solve the above-mentioned conventional problems, and in a polymer electrolyte fuel cell, provides a multiple seal structure capable of reliably ensuring sealing performance, and at the same time, a conflicting requirement of a stack. It is an object of the present invention to provide a polymer electrolyte fuel cell gasket and a polymer electrolyte fuel cell that can achieve downsizing, low fastening force, and improved corrosion resistance against combustible gas.

  In order to achieve the above object, the present invention is configured as follows.

The gasket for a polymer electrolyte fuel cell according to the first aspect of the present invention includes a membrane electrode assembly, a seal member disposed on both outer surfaces of the membrane electrode assembly, the membrane electrode assembly and the seal. A fuel assembled by laminating a plurality of unit cell modules having a pair of separators sandwiching a member to form a laminate, and sandwiched by a fastening member via a pair of end plates disposed at both ends of the laminate In a polymer electrolyte fuel cell comprising a battery stack,
The seal member is integrally formed on the outer peripheral portions of the front and back surfaces of the membrane electrode assembly,
As the seal member, two rows of seal lips each having sealing properties are continuously provided in parallel in a plane, and one of the two rows of seal lips has a mountain shape, and the flammable gas-side seal lip forms a mountain shape, An outside air-side seal lip located outside the combustible gas-side seal lip continuously formed with a gas-side seal lip forms a multi-stage mountain shape having at least one mountain shape, and the combustible gas A gasket for a polymer electrolyte fuel cell, characterized in that a height from the bottom of the side seal lip to the top of the mountain-shaped portion is smaller than a height from the bottom of the seal of the outside air seal lip to the top of the mountain-shaped portion I will provide a.

  As described above, according to the polymer electrolyte fuel cell gasket and the polymer electrolyte fuel cell of the present invention, it is possible to provide a multiple seal structure capable of reliably ensuring the sealing performance, and at the same time to reduce the size of the stack which is a conflicting requirement. It is possible to provide a seal structure that realizes a reduction in the tightening force and an improvement in corrosion resistance against combustible gas. Furthermore, since the outside air-side seal lip does not directly come into contact with a fluid such as combustible gas or water, it is possible to provide a seal structure that can improve the durability of the main lip.

1 is an exploded perspective view of a fuel cell stack according to Embodiment 1 of the present invention. FIG. 1 is a plan view showing the MEA and gasket structure of the fuel cell stack of FIG. Partial sectional view of the gasket structure in the conventional example (partial sectional view of the gasket structure in the conventional example with respect to the same part as the AA line in FIG. 2) The figure which shows the gasket structure of the fuel cell stack in 1st Embodiment of this invention (sectional drawing of the AA line of FIG. 2) The figure which shows the comparison of the stress of the lip seal vertex in the conventional gasket structure, and the stress of the lip seal vertex in the gasket structure of 1st Embodiment of this invention. The figure which shows the modification of the gasket of the fuel cell stack in Embodiment 1 of this invention The figure which shows the modification of the gasket of the fuel cell stack in Embodiment 1 of this invention The figure which shows the modification of the gasket of the fuel cell stack in Embodiment 1 of this invention The figure which shows the modification of the gasket of the fuel cell stack in Embodiment 1 of this invention The figure which shows the gasket structure of the fuel cell stack in Embodiment 2 of this invention Cross-sectional view of a conventional example in Patent Document 1 Cross-sectional view of a conventional example in Patent Document 2

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

(Embodiment 1)
FIG. 1 is a perspective view schematically showing a part of a structure of a fuel cell stack 30 as an example of a polymer electrolyte fuel cell (PEFC) according to a first embodiment of the present invention.

  As shown in FIG. 1, a fuel cell stack 30 includes a cell stack 20 in which a plurality of unit cell modules (cells) 1 are stacked at the center thereof. In addition, the current collector plate 2 and the end plate 3 having a large number of inner springs 4 as an example of an elastic body are disposed on the outermost layers at both ends of the cell stack 20. The four fastening bolts 7 in which the outer springs 5 are fitted into the head 7 a are connected to the end plate 3, the current collector plate 2, the cell laminate 20, the current collector plate 2, and the end from one end of the cell stack 20. The nut 3 is screwed and fastened through the bolt holes 6 at the respective corners of the plate 3.

  In the first embodiment, as an example, 60 cells 1 are stacked to form a cell stack 20, and are fastened by fastening bolts 7 and nuts 8 inserted into the bolt holes 6 as an example of fastening members. . Note that the fastening member is not limited to the fastening bolt 7 and the nut 8, and may have other configurations such as a fastening band.

  Each current collector plate 2 is disposed on both outer sides of the cell stack 20 and uses, as an example, a gold plate plated on a copper plate so that the generated electricity can be collected efficiently. The current collector plate 2 may be made of a metal material having good electrical conductivity, such as iron, stainless steel, or aluminum. Further, the surface treatment of each current collector plate 2 may be performed with tin plating, nickel plating, or the like. An end plate 3 using an electrically insulating material is disposed outside each current collecting plate 2 to insulate electricity, and also serves as an insulating function.

  Here, as the end plate 3, for example, a material manufactured by injection molding using polyphenylene sulfide resin is used. Each pipe 3 a integrated with the end plate 3 is pressed against each manifold of the cell stack 20 through a gasket (not shown) that functions as an example of a manifold seal member and has a manifold through hole. It is made to communicate. Inside each end plate 3, a large number of the inner springs 4 that apply a load to the cell 1 are provided in a projected portion of an electrolyte membrane electrode assembly (hereinafter referred to as “MEA”) 9, that is, inside the cell 1. The tightening dimensions are managed so that a load of, for example, 8.4 kN is applied to the cell stack 20 in a state where the cells are intensively and evenly disposed and tightened.

  The outer spring 5 is disposed between the head 7a of each fastening bolt 7 and the outer surface of the end plate 3, and is adjusted at the time of assembly by a plurality of fastening bolts 7 and a plurality of nuts 8, and is fastened at, for example, 10 kN. Has been.

  The cell 1 includes an MEA 9 having gaskets 14 as an example of sealing members on the peripheral portions of the front and back surfaces, and sandwiched between a pair of conductive separators 10, specifically an anode side separator 10a and a cathode side separator 10c. The cooling water separator 10w is arranged outside the separator, for example, the cathode side separator 10c. A pair of through holes, that is, manifold holes 11 through which fuel gas, oxidant gas, and cooling water circulate are formed in the peripheral portions of the separators 10a and 10c and the MEA 9.

  The cooling water separator 10w is provided with a pair of through holes, that is, manifold holes 11, through which fuel gas, oxidant gas, and cooling water flow. In the state of the cell stack 20 in which a plurality of cells 1 are stacked, these manifold holes 11 are stacked and communicate with each other, and a hold, an oxidant gas manifold, and a cooling water manifold are formed independently between fuel gases. ing.

  The MEA main body 9a includes a polymer electrolyte membrane that selectively transports hydrogen ions, and a pair of electrode layers formed on the inner and outer surfaces of the inner portion of the polymer electrolyte membrane, that is, an anode and a cathode. It consists of an electrode layer. The electrode layer has a laminated structure having a gas diffusion layer and a catalyst layer disposed between the gas diffusion layer and the polymer electrolyte membrane.

  The anode-side separator 10a and the cathode-side separator 10c have a flat plate shape, and the surface that comes into contact with the MEA 9, that is, the inner surface, has a shape corresponding to the shape of the MEA main body 9a and the gasket 14, respectively. is doing. As an example, glassy carbon (thickness 3 mm) manufactured by Tokai Carbon Co., Ltd. can be used for each of the anode side separator 10a and the cathode side separator 10c. In each separator 10a, 10c, 10W, various manifold holes and bolt holes 6 penetrate each separator 10a, 10c, 10w in the thickness direction.

  In addition, a fuel gas channel groove 12a and an oxidant gas channel groove 116c are formed on the inner surfaces of the separators 10a, 10c, and 10w, respectively, and cooling is performed on the inner surface of the separator 10w (the surface on the cathode side separator 10c side). A water channel groove 12w is formed. The various manifold holes, the bolt holes 6, the fuel gas passage grooves 12a, the oxidant gas passage grooves 116c, the cooling water passage grooves 12w, and the like are formed by cutting or molding.

  The gaskets 14 respectively disposed on the front and back surfaces of the MEA 9 are seal members made of an elastic body, are integrally formed with the MEA 9, and are formed on the inner surfaces of the separators 10a and 10c by pressing the MEA 9 and the separators 10a and 10c. The gasket 14 is deformed according to the shape, and the outer periphery of the MEA main body 9 a and the outer periphery of the manifold hole 11 are sealed with the gasket 14. On the back surface (outer surface) opposite to the MEA 9 of the anode side separator 10a and the cathode side separator 10c, a general sealing member (not shown) such as a squeeze packing made of a heat-resistant material is provided around various manifold holes 11. Is arranged. The seal member such as the packing prevents leakage of each of the fuel gas, the oxidant gas, and the cooling water from the connecting portion between the cells 1 of the various manifold holes 11 between the adjacent cells 1.

  Here, FIG. 2 shows a plan view of a more specific structure of the MEA 9 of the fuel cell stack 30 in the first embodiment.

  In the figure, a frame 13 is formed on the outer periphery of the MEA 9, and a gasket 14 is formed on the outer periphery of the MEA main body 9 a and the manifold hole 11. FIG. 3B shows a partial cross section AA of the main body 9a, the frame 13 and the gasket 14 of the MEA. 3A shows a partial cross-sectional view of the gasket structure when the MEA 109 of the conventional example is cut at the same portion, and FIG. 3B shows a partial cross-sectional view of the structure of the gasket 14 of the first embodiment. .

  3 (a) and 3 (b), a frame 113 and a frame 13 made of resin are provided on the outer periphery of the MEA 109 and MEA 9 by molding, and gaskets 114 and upper and lower surfaces on the frame 113 and the frame 13 are provided. The gasket 14 is integrally formed. Here, in the conventional example and the first embodiment described above, the gasket 114-1, the gasket 14-1, the gasket 114-2, and the gasket 14- formed on the upper and lower surfaces of the frame 113 and the frame 13 are shown. 2 have the same cross-sectional shape at the top and bottom.

  In the first embodiment described above, the gasket 14-1 and the gasket 14-2 formed on the upper and lower surfaces of the frame 13 have the same cross-sectional shape in the upper and lower directions, but the present invention is limited to this. Instead, for example, depending on the type, temperature, or pressure condition of the fluid flowing in the upper and lower portions of the MEA 9 in FIG. 3B, the upper surface is formed in the conventional gasket shape, but only the lower surface is the first embodiment. The shape of the gasket 14 may be used. More specifically, for example, when only the cooling water flows on the upper surface, the upper surface is preferably sealed by the conventional gasket 114, and when the combustible gas or the oxidant gas flows on the lower surface, the first When the multi-seal gasket 14 according to the embodiment is employed, the remarkable effect according to the first embodiment can be exhibited on the lower surface where stricter sealing performance is required than the upper surface.

  As an example, a glass fiber-added polypropylene can be used as the frame 13, and a kind of olefin-based thermoplastic elastomer can be used as the gasket 14. As a gasket material, a thermosetting resin has a very high fluidity at the time of molding, and the MEA 9 electrode is impregnated. Therefore, a thermoplastic resin is preferable. Further, if each of the frame 13 and the gasket 14 is made of a material having adhesiveness, the sealing performance is further improved.

  FIG. 3A is a partial cross-sectional view showing the structure of a conventional gasket 114, and the seal lip 114a has a one-step mountain structure. FIG. 3B is a partial cross-sectional view showing the seal structure of the first embodiment described above. Since the upper and lower gaskets 14-1 and 14-2 have the same shape, the upper gasket 14-1 will be described below as a representative example.

  The gasket 14-1 formed integrally with the frame body 13 is a quadrangular frame-shaped combustible gas side that is continuous in parallel in the plane of the MEA 9 in parallel with each side of the square, which is the outer shape of the MEA main body 9a. The first seal lip 15 and the quadrangular frame-shaped second seal lip 16 are configured, and the first seal lip 15 is configured in a one-step mountain shape in the vertical direction (thickness direction) of FIG. The two seal lips 16 are formed in a mountain shape having at least two steps in the vertical direction (thickness direction) in FIG.

  More specifically, the gasket 14-1 has a first seal lip 15 disposed on the combustible gas side (left side of FIG. 3B) in the cross-sectional view of FIG. It is comprised from the 1st upper mountain-shaped part 15a of the raised 1st step. Further, the second seal lip 16 arranged on the main body 9a side (the right side in FIG. 3B) of the MEA has a second lower mountain-shaped portion 16a in the first step raised from the surface of the frame body 13. The second upper side of the second step further raised from the vicinity of the second lower peak 16b as the peak of the second lower peak 16a and the second lower peak 16b of the second lower peak 16a It is formed by a mountain-shaped portion 16c and a second lip seal vertex 16d as the vertex of the second upper mountain-shaped portion 16c. Even in a plan view, the radius of curvature of the bottom surface portion of the second upper mountain-shaped portion 16c is smaller than the radius of curvature near the second lower peak 16b of the second lower mountain-shaped portion 16a, and the second A step portion is formed at the joint between the upper mountain-shaped portion 16c and the second lower mountain-shaped portion 16a.

  The height H1 of the first seal lip 15 is set to be lower than the height H2 of the second seal lip 16. Further, the bottom portion of the first upper mountain-shaped portion 15a and the bottom portion of the second lower mountain-shaped portion 16a are integrated to form a continuous portion 14p, between the first seal lip 15 and the second seal lip 16. Has a continuous shape. The height H3 of the continuous portion 14p between the first seal lip 15 and the second seal lip 16 is set lower than the height H4 from the frame 13 to the separator holding position after stack assembly.

  4A to 4D show the shapes of the inner surfaces of the separators 10a and 10c when the gaskets 14-1 and 14-2 configured as in the first embodiment of the present invention are pressed against the separator 10c. It is a figure which shows a mode that the gasket 14-1 changes in response.

  When the stack is assembled, first, the second upper mountain-shaped portion 16c comes into contact with the separators 10a and 10c (FIG. 4B), and the second upper mountain-shaped portion can be easily and greatly elastically deformed. The part 16c functions. Further, the separators 10a and 10c are pressed, and the first upper mountain-shaped portion 15a comes into contact (FIG. 4C). After the second upper mountain-shaped portion 16c is greatly elastically deformed as the easily deformable portion, the seal area that expands the seal area between the separators 10a and 10c by deforming the apex portion of the second lower mountain-shaped portion 16a. The second lower mountain-shaped portion 16a functions as an enlarged portion (FIG. 4C).

  As a result, when a tightening load is applied during stack assembly, the apexes of the first seal lip 15 and the second seal lip 16 come into stable contact with the opposing surface of the separator 10a or 10c and start elastic deformation. Thus, the stack 30 and the unit cell module 1 can be reliably reduced in size (FIG. 4D). In addition, regarding the stress distribution generated in the gasket 14-1 (14-2), the stress σ9 generated in the first upper mountain-shaped portion 15a of the first seal lip 15 is higher than the normal gas pressure, and the second seal lip 16 is smaller than the stress σ1 generated in the second upper mountain-shaped portion 16c. Furthermore, σ1 should be lower than the allowable stress of the sealing material. The first seal lip 15 and the second seal lip 16 are brought into contact with the opposing surfaces of the separator 10a or 10c to exhibit the sealing performance, so that the first sealing lip 15 exhibits the sealing performance at the time of low load pressure resistance during normal operation. The second seal lip 16 provides a double seal structure that can guarantee the seal performance more effectively by providing the function so that the second seal lip 16 exhibits the seal performance at the time of high load pressure resistance during abnormal operation. it can.

  Therefore, since the sealing performance is improved as compared with the conventional case, the effect that the seal height can be made lower than that of the conventional example and the reaction force can be reduced is also exhibited. Further, when materials having no adhesiveness are used as the materials of the frame 13 and the gasket 14, respectively, if the surface roughness of the surface of the frame 13 where the gasket 14 is molded is roughened, It is effective for improvement. The gasket 14 can also be formed of a resin material such as synthetic rubber, EPDM, or silicone.

  FIG. 3 (c) shows the stress 20 of the lip seal apex 114r generated when a double seal is formed with the conventional gasket shape of FIG. 3 (a), and the first embodiment of the present invention shown in FIG. 3 (b). It is a figure which shows the simulation result which compared the stress 21 of the 1st lip seal vertex 15d which generate | occur | produces in the case of this gasket shape, and the stress 22 which generate | occur | produces in the 2nd lip seal vertex 16d.

  In the figure, the vertical axis represents the stress generated at the apex of the seal lip, and the horizontal axis represents the compression ratio when the gasket is pressed. The simulation was performed with general-purpose structural analysis software ABAQUS using the finite element method of SIMULIA, USA. In the shape of the gasket 14 according to the first embodiment of the present invention, the first lip seal and the second lip seal are provided with functionality, so that the stress 21 generated in the first lip seal is about 64% of the conventional example. Can be reduced. As a result, compared with a double seal structure in which two gaskets 114 are arranged in parallel, the area occupied by the gasket 14 in the unit cell module 1 can be reduced, so that space can be saved and the stack 30 can be downsized. Further, by lowering the fastening force and lowering the stress of the first lip seal reaction force, it is possible to realize an improvement in durability with little deterioration of the rubber by the combustible gas.

  In addition, this invention is not limited to the said embodiment, It can implement in another aspect so that it may illustrate below.

(Embodiment 2)
FIG. 5 shows a partial cross-sectional view of the seal structure of the second embodiment of the present invention.

  The gasket 14 comprises first seal lips 15 on both sides of the second seal lip 16, respectively. The height of the second seal lip 16 is H2, the height of the first lip seal is H1, and the relationship is H1. <H2. Since the same or different fluids do not directly contact the first lip seal, it is possible to improve durability against fluids such as combustible gas.

  In FIG. 5, the two first lip seal heights are made equal, but the two lip seal heights may be different from each other without being limited to this.

  The gasket for a polymer electrolyte fuel cell of the present invention is useful as a gasket for a fuel cell used for a portable power source, an electric vehicle power source, a home cogeneration system, or the like.

9,109 MEA
9a MEA main body 13, 113 Frame 14, 114, 114-1, 114-2, 303 Gasket 14-1 Gasket on the upper surface of the frame 13 14-2 Gasket on the lower surface of the frame 13 14p Continuous portion 15 First seal lip 15a 1st upper mountain shape part 15d 1st lip seal vertex 16 2nd seal lip 16a 2nd lower mountain shape part 16b 2nd lower vertex 16c 2nd upper mountain shape part 16d 2nd lip seal vertex

Claims (3)

Two rows of seal lips are provided continuously in parallel in the plane,
Of the two rows of seal lips, one seal lip has a mountain shape, and the other seal lip has a multi-stage mountain shape having at least one mountain shape,
And the height from the seal bottom of the one seal lip to the top of the mountain-shaped portion is smaller than the height of the top of the mountain-shaped portion from the seal bottom of the other seal lip,
A polymer electrolyte type fuel cell gasket. A membrane electrode assembly;
A seal member disposed on the outer periphery of at least one surface of the membrane electrode assembly;
A pair of separators sandwiching the membrane electrode assembly and the seal member;
A polymer electrolyte type comprising a fuel cell stack that is assembled by laminating a plurality of unit cell modules having a structure to form a laminated body and sandwiched by a fastening member via a pair of end plates disposed at both ends of the laminated body In fuel cells,
The seal member is integrally formed on an outer peripheral portion of at least one side of the membrane electrode assembly, and two rows of seal lips each having a sealing property are continuously provided in parallel in the plane, and the two rows Among the seal lips, one combustible gas side seal lip has a mountain shape, and the outside air side seal lip is constituted by a multi-stage mountain shape having at least one mountain shape,
The height from the bottom of the flammable gas side seal lip to the top of the mountain-shaped portion is smaller than the height of the top of the mountain-shaped portion from the bottom of the seal on the outside air side seal lip,
A polymer electrolyte fuel characterized by The seal member is provided with three rows of seal lips each provided with a sealing property in parallel in a plane,
H ₁ is the height from the fluid side seal lip frame to the peak of the mountain-shaped part,
The height H ₂ of the apex of the mountain-shaped portion from the seal lip frame disposed next to the fluid side seal lip,
When the height from the frame body of the fluid side seal lip disposed next to the seal lip to the apex of the mountain-shaped portion is H ₃ ,
The correlation between the heights H ₁ , H ₂ and H ₃ is
H ₁ <H ₂ and H ₃ <H ₂ are satisfied,
The height of the portion between the three rows of seal lips is formed to be lower than the height at which the two rows of seal lips are tightened by the separators on the front and back surfaces of the membrane electrode assembly.
The gasket for a polymer electrolyte fuel cell according to claim 2.

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