JP5194392B2 - Fuel cell stack - Google Patents

Description

  The present invention relates to a fuel cell stack, and more particularly to a fuel cell stack capable of reducing damage to an electrolyte membrane.

  A fuel cell has a membrane electrode assembly (hereinafter referred to as “MEA (Membrane Electrode)” including an electrolyte layer (hereinafter referred to as “electrolyte membrane”) and electrodes (anode and cathode) respectively disposed on both sides of the electrolyte membrane. The electrical energy generated by the electrochemical reaction in “) is taken out to the outside through current collectors (for example, separators) respectively disposed on both sides of the MEA. Among fuel cells, polymer electrolyte fuel cells (hereinafter referred to as “PEFC (Polymer Electrolyte Fuel Cell)”) used in household cogeneration systems and automobiles are low temperature regions. Is possible. In addition, PEFC has attracted attention as an optimal power source for electric vehicles and portable power sources because of its high energy conversion efficiency, short start-up time, and compact and lightweight system.

  A single cell of PEFC includes an electrolyte membrane that is maintained in a water-containing state and exhibits proton conduction performance, and a cathode and an anode that include at least a catalyst layer, and has a theoretical electromotive force of 1.23V. However, since such low electromotive force is insufficient as a power source for electric vehicles and the like, usually, a single cell is laminated in series to form a laminated body, and end plates or the like are formed at both ends of the laminated body in the lamination direction. A fuel cell in the form of a stack formed by arranging is used. From the viewpoint of reducing the contact resistance, a fastening pressure (hereinafter sometimes referred to as “compression pressure”) is applied from both ends of the stack type fuel cell.

  During PEFC operation, a hydrogen-containing gas is supplied to the anode, and an oxygen-containing gas is supplied to the cathode. The hydrogen supplied to the anode is separated into protons and electrons on the catalyst contained in the catalyst layer of the anode (hereinafter also referred to as “anode catalyst layer”), and the protons generated from the hydrogen are separated from the anode catalyst layer. And reaches the cathode catalyst layer (hereinafter also referred to as “cathode catalyst layer”) through the electrolyte membrane. On the other hand, electrons reach the cathode catalyst layer through an external circuit, and protons and electrons that have reached the cathode catalyst layer react with oxygen supplied to the cathode catalyst layer to generate water. .

  Thus, various substances such as hydrogen-containing gas, oxygen-containing gas, and water can exist in a single cell of PEFC. Here, the single cell needs to have high airtightness for the purpose of improving the power generation performance of the PEFC by supplying a large amount of hydrogen and oxygen to the catalyst provided in the anode catalyst layer and the cathode catalyst layer. Therefore, in a single cell of PEFC, for example, a sealing member having a gas sealing function or the like is disposed on the outer edge portion of the electrolyte membrane (at least a part of the periphery of the catalyst layer formed in the central portion of the electrolyte membrane), The electrolyte membrane is held through a pair of sealing members to which the fastening pressure is applied, thereby preventing leakage of the various substances to the outside of the single cell.

As a technique related to a seal member provided in PEFC, Patent Document 1 discloses a seal member that receives a surface pressure from two surfaces and prevents fluid leakage in at least two spaces, and is elastic with other portions of the seal member. A sealing member is disclosed in which layered portions in the plane direction with different rates are formed. Furthermore, Patent Document 1 also discloses a technique related to a fuel cell including the seal member. According to such a technique, by forming a layered portion in a plane direction with different elastic moduli, it is possible to follow a dimensional change due to heat or the like of one or both surfaces acting on the surface pressure, It is said that the performance and reliability of the fuel cell can be improved by ensuring the sealing performance and the formability in the surface pressure direction, that is, the stacking direction.
JP 2000-182039 A

  As described above, since water is generated during operation of the PEFC, the electrolyte membrane can expand. On the other hand, when the PEFC is stopped, the hydrogen-containing gas and the oxygen-containing gas are not supplied and water is not generated. Therefore, when the PEFC is stopped, the electrolyte membrane can be dried and shrink. Therefore, when the operation / stop of the PEFC is repeated, the expansion / contraction of the electrolyte membrane can be repeated. On the other hand, as described above, the airtightness of the single cell of PEFC is maintained by sandwiching the electrolyte membrane via a pair of seal members. Here, since the fastening pressure is applied to the outer edge portion of the electrolyte membrane where the expansion / contraction is repeated via a pair of seal members, when the electrolyte membrane repeatedly expands / contracts, stress is applied to the outer edge portion of the electrolyte membrane. There is a problem that the electrolyte membrane tends to be damaged due to concentration.

  The sealing member disclosed in Patent Document 1 is formed with layered portions in the surface direction having different elastic moduli. Therefore, even in an environment where fastening pressure is applied, if the state where the layered portion can function as an elastic body is secured, it is possible to follow the dimensional change of the electrolyte membrane, and damage the electrolyte membrane. It will be possible to suppress it. However, since the fastening pressure of the PEFC used in the stack form is a pressure of about 1 MPa, for example, even if the seal member of the form disclosed in Patent Document 1 is applied, it is applied to the outer edge of the electrolyte membrane. It is difficult to alleviate stress concentration, and there is a problem that it is difficult to suppress damage to the electrolyte membrane.

  Therefore, an object of the present invention is to provide a fuel cell stack capable of reducing damage to the electrolyte membrane.

In order to solve the above problems, the present invention takes the following means. That is,
The present invention described in claim 1 includes an electrolyte membrane, a first catalyst layer provided at the center of one surface of the electrolyte membrane, a second catalyst layer provided at the center of the other surface of the electrolyte membrane, and an electrolyte membrane. A structure having a first shaped member disposed on an outer edge portion on one side of the liquid crystal and a second shaped member disposed on an outer edge portion on the other side of the electrolyte membrane, and on one side of the structure body A laminated body having a first separator and a second separator laminated on the other side of the structure, and between the first shaped member and the electrolyte membrane, and between the second shaped member and the electrolyte membrane. between, provided with a resilient member, the space securing unit to secure a space filled with the elastic member, first shaped member, a second shaped member, and / or, a first shaped member and the second shaped member In a direction parallel to the plane whose normal direction is the stacking direction of the stacked body. That state, and are spaced 5mm or 20mm or less between the outer and the space reserved portion of the electrolyte membrane, when the thickness of the electrolyte membrane when dried is T, the length in the stacking direction of the space securing unit There characterized der Rukoto than 200T less 2.5T, a fuel cell stack.

  Here, the “outer edge portion of the electrolyte membrane” refers to the electrolyte membrane from the entire surface (X) of the electrolyte membrane when the diffusion layer is not provided on the first catalyst layer side and the second catalyst layer side of the structure. And the contact surface (Y1) between the first catalyst layer and the contact surface (Y2) between the electrolyte membrane and the second catalyst layer (X-Y1-Y2). In addition, when the first diffusion layer and / or the second diffusion layer is provided on the first catalyst layer side and / or the second catalyst layer side of the structure, from the outer edge portion (XY1-Y2), Furthermore, the contact surface (Z1) between the electrolyte membrane and the first diffusion layer and / or the portion excluding the contact surface (Z2) between the electrolyte membrane and the second diffusion layer (when the first diffusion layer is provided; XY1) -Y2-Z1, when the second diffusion layer is provided; XY1-Y2-Z2, when the first diffusion layer and the second diffusion layer are provided; XY1-Y2-Z1-Z2) is the electrolyte membrane Corresponds to the outer edge. In addition, “an elastic member is provided between the first shaped member and the electrolyte membrane and between the second shaped member and the electrolyte membrane” means that the first fixed shape provided at the outer edge of the electrolyte membrane. It means that an elastic member is provided between the member and the second shaped member and the outer edge surface of the electrolyte membrane. That is, in the present invention, the elastic member is provided only at the outer edge portion of the electrolyte membrane. Furthermore, the “stacking direction of the stacked body” means a direction in which the structure, the first separator, and the second separator are stacked. Furthermore, “the space securing portion is provided in the first shaped member, the second shaped member, and / or between the first shaped member and the second shaped member” means “the first shaped member. "Form provided only in the second shaped member", "form provided only in the second shaped member", "form provided only in the first shaped member and the second shaped member", "between the first shaped member and the second shaped member "Forms provided only between", "Forms provided between the first shaped member and the second shaped member in addition to the first shaped member", "In addition to the second shaped member, the first shaped member and the second shaped member The space securing portion is in a form provided between the first shaped member and the second shaped member in addition to the first shaped member and the second shaped member. It means that it is provided.

The present invention of claim 2 is the fuel cell stack according to claim 1, the elastic member, fluorine rubber, or, characterized in that it is constituted by a silicone rubber.

  Examples of the fluororubber that can constitute the elastic member include vinylidene fluoride rubber (FKM), tetrafluoroethylene-propylene rubber (FEPM), tetrafluoroethylene-perfluorovinyl ether rubber (FFKM), and the like. be able to. Examples of the silicone rubber that can constitute the elastic member include vinyl methyl silicone rubber (VMQ) and fluorinated silicone rubber (FVMQ).

  According to the present invention, since the space securing portion is provided, the elastic member disposed on the outer edge portion of the electrolyte membrane is provided in a form that can function as an elastic body. Therefore, even if the dimensions of the electrolyte membrane change, the shape of the elastic member can change following the dimensional change, and the stress that can be concentrated on the outer edge of the electrolyte membrane is reduced. Damage can be reduced. Therefore, according to the present invention, a fuel cell stack capable of reducing damage to the electrolyte membrane can be provided.

  The electrolyte membrane that can swell / shrink due to repeated operation / stop of PEFC is sandwiched at its outer edge via a shaped member having a sealing function or the like. In PEFC, since the fastening pressure is usually applied from both ends of the stack for the purpose of reducing contact resistance, etc., when the swelling / shrinkage of the electrolyte membrane is repeated, it is sandwiched through the shaped member. Stress concentrates on the outer edge and is easily damaged. In order to suppress such damage, it is effective to reduce the stress applied to the outer edge portion of the electrolyte membrane. As a means for realizing this, at least a part of the member in contact with the outer edge portion is made of an elastic material. It can be considered that However, in a stack-type PEFC, a fastening pressure of 1 MPa is applied from both ends, so even if a part of the shaped member is simply made of an elastic material, it functions as an elastic body required for the elastic material. It is hard to be demonstrated. In order to suppress damage to the electrolyte membrane while ensuring the sealing function required for the shaped member, it is important to adopt a configuration in which the elastic material can function as an elastic body.

  The present invention has been made from such a viewpoint, and the gist thereof is that an elastic member is disposed between the shaped member and the electrolyte membrane, and the elastic member is used as an elastic body even in an environment in which a fastening pressure is applied. Providing a fuel cell stack capable of reducing damage to an electrolyte membrane by providing a space securing portion that enables functioning to be provided in either or both of a pair of shaped members, or between them. It is in.

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

1. First Embodiment FIG. 1 is a cross-sectional view schematically showing a part of a fuel cell stack of the present invention according to a first embodiment, and is a laminate (hereinafter referred to as “single cell” provided in the fuel cell stack of the present invention. ")") Only a part of it is shown enlarged. FIG. 2 is a schematic diagram showing an example of the form of a fuel cell stack according to the present invention including the single cell of the form shown in FIG. Hereinafter, the fuel cell stack of the present invention will be described with reference to FIGS. 1 and 2.

  As shown in FIG. 1, the single cell 20 according to the first embodiment includes an electrolyte membrane 1, a first catalyst layer 2 a provided at one surface central portion of the electrolyte membrane 1, and a first central portion provided at the other central portion. Two catalyst layers 3a, a first diffusion layer 2b provided on the one side of the electrolyte membrane 1, and a second diffusion layer 3b provided on the other side. The first fixed member 10 having the frame shape and the second fixed member 11 having the frame shape disposed on the other side are sandwiched between the first fixed member 10 and the second fixed member 10. An elastic member 9 is provided between the fixed member 11 and the electrolyte membrane 1. The anode 2 of the single cell 20 includes a first catalyst layer (hereinafter referred to as “anode catalyst layer”) 2 a and a first diffusion layer (hereinafter referred to as “anode diffusion layer”) 2 b, and the cathode 3 includes a second The MEA 4 includes a catalyst layer (hereinafter referred to as “cathode catalyst layer”) 3a and a second diffusion layer (hereinafter referred to as “cathode diffusion layer”) 3b, and the MEA 4 includes the electrolyte membrane 1, the anode catalyst layer 2a, and the cathode catalyst layer. 3a. The structure 16 provided in the single cell 20 includes the MEA 4, the anode diffusion layer 2 b and the cathode diffusion layer 3 b, the elastic member 9, the first shaped member 10, and the second shaped member 11. The first separator 5 and the second separator 6 are laminated on the one side and the other side, respectively. The first separator 5 is provided with first reaction gas passages 7, 7,..., And the second separator 6 is provided with second reaction gas passages 8, 8,. Sometimes hydrogen is supplied to the anode 2 from the first reaction gas flow paths 7, 7,..., And oxygen is supplied to the cathode 3 from the second reaction gas flow paths 8, 8,. The first fixed member 10 and the second fixed member 11 of the single cell 20 are provided with space securing portions 10x and 11x, respectively, and the elastic member 9 and the electrolyte membrane in the stacking direction are provided by the space securing portions 10x and 11x. 1 space is secured.

  Here, in the single cell 20 according to the first embodiment, the electrolyte membrane 1 is a solid polymer membrane (for example, Selemion (“Selemion” is a registered trademark of Asahi Glass Co., Ltd.)) having a hydrocarbon ionomer. . The anode catalyst layer 2a and the cathode catalyst layer 3a are provided with platinum that functions as an electrochemical reaction catalyst, and the anode diffusion layer 2b and the cathode diffusion layer 3b are made of carbon paper or the like. Furthermore, the 1st fixed member 10 and the 2nd fixed member 11 are comprised by resin, such as glass epoxy, for example, and the elastic member 9 is comprised by fluororubber etc. FIG. Further, in the single cell 20, an adhesive (for example, an epoxy resin adhesive, etc., the same applies hereinafter) is disposed between the outer edge portion of the electrolyte membrane 1 and the elastic member 9, and the elastic member 9. An adhesive is also disposed between the first fixed member 10 and the second fixed member 11 and a compressive pressure is applied in the stacking direction, so that the airtightness of the single cell 20 is ensured.

  On the other hand, as shown in FIG. 2, the fuel cell stack 100 according to the first embodiment is provided on both ends of the plurality of single cells 20, 20,. Plate members 21, 22 and fastening means 23 for applying a fastening pressure (compression pressure) in the stacking direction of the single cells 20, 20, ... via the plate members 21, 22 are provided. 20,..., The plate-like members 21, 22 and the fastening means 23 are accommodated in the outer frame body 24.

  Thus, in the fuel cell stack 100, a compression pressure is applied in the stacking direction. Therefore, when compression pressure is applied to the outer edge portion of the electrolyte membrane 1 held between the first and second shaped members 10 and 11, and the swelling / shrinkage of the electrolyte membrane 1 is repeated, the outer edge portion Stress tends to concentrate on Therefore, in the single cell 20, the first fixed member 10 is provided with the space securing portion 10 x and the second shaped member 11 is provided with the space securing portion 11 x, and the first shaped member 10, the second shaped member 11, An elastic member 9 is disposed between the electrolyte membrane 1 and the electrolyte membrane 1. With such a configuration, it is possible to prevent the outer member of the elastic member 9 and the electrolyte membrane 1 from being excessively compressed in the stacking direction by the space securing portions 10x and 11x while ensuring the airtightness of the single cell 20. Even when the battery stack 100 is in operation, the elastic member 9 can function as an elastic body. That is, according to the first embodiment, when the fuel cell stack 100 (single cell 20) is operated and stopped, the function of the elastic member 9 as an elastic body is ensured, so that the outer edge of the electrolyte membrane 1 is moved to. The applied compressive stress can be reduced. In addition, according to the single cell 20, the function of the elastic member 9 as an elastic body is ensured. Therefore, the electrolyte membrane 1 swells / shrinks, so that the electrolyte membrane 1 bonded to the elastic member 9 with an adhesive is used. Even if the dimensions change, the elastic member 9 can be deformed following the dimensional changes of the electrolyte membrane 1. Therefore, even when the electrolyte membrane 1 contracts due to drying or the like, a gap that can be formed between the outer edge portion of the electrolyte membrane 1 and the elastic member 9 can be minimized, so that the outer edge portion of the electrolyte membrane 1 It is possible to effectively alleviate the stress concentration on the electrolyte membrane and to reduce damage to the electrolyte membrane 1.

2. Second Embodiment FIG. 3 is a cross-sectional view schematically showing a part of the fuel cell stack of the present invention according to the second embodiment, and only a part of a single cell provided in the fuel cell stack of the present invention is enlarged. As shown. The fuel cell stack of the present invention according to the second embodiment is used, for example, in a form in which the single cells 20, 20,... In FIG. 2 are replaced with the single cells according to the second embodiment. 3, components having the same configuration as the members shown in FIG. 1 are denoted by the same reference numerals as those used in FIG. 1, and description thereof will be omitted as appropriate. Hereinafter, the fuel cell stack of the present invention will be described with reference to FIG.

  As shown in FIG. 3, the unit cell 30 according to the second embodiment includes an electrolyte membrane 1, an MEA 4 including an anode catalyst layer 2a and a cathode catalyst layer 3a, an anode diffusion layer 2b and a cathode diffusion layer 3b, a frame A first shaped member 12 and a second shaped member 13 having a mold shape; and an elastic member 9 disposed between the first shaped member 12 and the second shaped member 13 and the outer edge of the electrolyte membrane 1. The structure 17 is provided. The first separator 5 is laminated on one side of the structure 17 and the second separator 6 is laminated on the other side. An adhesive is disposed between the outer edge of the electrolyte membrane 1 and the elastic member 9, and between the elastic member 9, the first fixed member 12, and the second fixed member 13, and is compressed in the stacking direction. By applying the pressure, the airtightness of the single cell 30 is secured.

  As shown in FIG. 3, in the single cell 30, only the first shaped member 12 is provided with a space securing part 12 x, and the second shaped member 13 is not provided with a space securing part. Even in such a form, since the single cell 30 includes the space securing portion 12x in the first fixed member 12, an environment in which compression pressure is applied via the first fixed member 12 and the second fixed member 13 is provided. Even so, the space securing portion 12x can prevent the outer edge portions of the elastic member 9 and the electrolyte membrane 1 from being excessively crushed, and the elastic member 9 can function as an elastic body. That is, even in the second embodiment, the function of the elastic member 9 as an elastic body is ensured when the single cell 30 is activated and stopped, so that the compression pressure applied to the outer edge of the electrolyte membrane 1 is reduced. Can be reduced. In addition, since the function of the elastic member 9 as an elastic body is ensured even in the form of the single cell 30, the electrolyte membrane 1 is swelled / shrinked, so that the electrolyte bonded to the elastic member 9 with an adhesive Even if the dimension of the membrane 1 changes, the elastic member 9 can be deformed following the dimensional change of the electrolyte membrane 1. Therefore, for example, even when the electrolyte membrane 1 contracts, the formation of a gap that can be formed between the outer edge portion of the electrolyte membrane 1 and the elastic member 9 is prevented, or the size of the gap is minimized. be able to. Therefore, the stress concentration on the outer edge of the electrolyte membrane 1 is effectively alleviated, and damage to the electrolyte membrane 1 can be suppressed. Therefore, even in the fuel cell stack in which the single cell 30 is provided, damage to the electrolyte membrane can be reduced.

  In the above description according to the second embodiment, the space securing part 12x is provided only in the first fixed member 12, and the space securing part is not provided in the second shaped member 13, but the present invention is in this form. It is not limited and it is also possible to adopt a form in which the space securing part is provided only in the second shaped member and the space securing part is not provided in the first shaped member.

3. Third Embodiment FIG. 4 is a cross-sectional view schematically showing a part of the fuel cell stack of the present invention according to the third embodiment, and only a part of a single cell provided in the fuel cell stack of the present invention is enlarged. As shown. The fuel cell stack of the present invention according to the third embodiment is used, for example, in a form in which the single cells 20, 20,... In FIG. 2 are replaced with the single cells according to the third embodiment. 4, components having the same configuration as the members shown in FIG. 1 and / or FIG. 2 are denoted by the same reference numerals as those used in FIG. 1, and description thereof is omitted as appropriate. Hereinafter, the fuel cell stack of the present invention will be described with reference to FIG.

  As shown in FIG. 4, the single cell 40 according to the third embodiment includes an electrolyte membrane 1, an MEA 4 including an anode catalyst layer 2a and a cathode catalyst layer 3a, an anode diffusion layer 2b and a cathode diffusion layer 3b, a frame The first shaped member 14, the second shaped member 13, and the space securing portion 15, the first shaped member 14, the second shaped member 13, and the outer edge portion of the space securing portion 15 and the electrolyte membrane 1. And an elastic member 9 disposed between them. The first separator 5 is laminated on one side of the structure 18 and the second separator 6 is laminated on the other side. An adhesive is disposed between the outer edge of the electrolyte membrane 1 and the elastic member 9, and between the elastic member 9 and the first shaped member 14, the second shaped member 13, and the space securing portion 15. The airtightness of the single cell 40 is ensured by the compression pressure being applied in the stacking direction.

  As shown in FIG. 4, in the single cell 40, a space securing portion 15 is provided between the first shaped member 14 and the second shaped member 13, and space is secured in the first shaped member 14 and the second shaped member 13. Department is not provided. Even in such a form, the unit cell 40 includes the space securing portion 15 between the first and second shaped members 14 and 13, so the first and second shaped members 14 and 13 are provided. Even in an environment where compression pressure is applied through the space, the space securing portion 15 can prevent the elastic member 9 and the outer edge portion of the electrolyte membrane 1 from being crushed excessively, and the elastic member 9 can function as an elastic body. Can do. That is, even in the third embodiment, since the function of the elastic member 9 as an elastic body is ensured when the single cell 40 is activated and stopped, the compression pressure applied to the outer edge portion of the electrolyte membrane 1 is reduced. Can be reduced. In addition, since the function of the elastic member 9 as an elastic body is ensured even in the form of the unit cell 40, the electrolyte membrane 1 is swelled / shrinked, so that the electrolyte bonded to the elastic member 9 with an adhesive Even if the dimension of the membrane 1 changes, the elastic member 9 can be deformed following the dimensional change of the electrolyte membrane 1. Therefore, for example, even when the electrolyte membrane 1 contracts, the formation of a gap that can be formed between the outer edge portion of the electrolyte membrane 1 and the elastic member 9 is prevented, or the size of the gap is minimized. be able to. Therefore, the stress concentration on the outer edge of the electrolyte membrane 1 is effectively alleviated, and damage to the electrolyte membrane 1 can be suppressed. Therefore, even in the fuel cell stack in which the single cell 40 is provided, damage to the electrolyte membrane can be reduced.

  The length of the space securing portion provided in the fuel cell stack of the present invention in the stacking direction is not particularly limited as long as the elastic member can function as an elastic body. However, when T is the thickness of the electrolyte membrane when it is dry, the thickness of the electrolyte membrane may be about 2T during swelling. Therefore, the length of the space securing portion in the stacking direction (the total length of the space securing portions 10x and 11x in the stacking direction in the first embodiment shown in FIG. 1, the space securing portion in the second embodiment shown in FIG. The length in the stacking direction of 12x, that is, the length in the stacking direction of the space securing portion 15 in the third embodiment shown in FIG. On the other hand, if the length in the stacking direction is too long, the volume of the single cell increases, and the power generation density of the fuel cell stack may be reduced. A more preferable length in the stacking direction is 2.5T or more and 100T or less.

  In addition, the distance between the outer edge portion of the electrolyte membrane and the space securing portion in a direction parallel to the plane having the normal direction as the stacking direction (for example, the horizontal direction in FIGS. 1 to 4, hereinafter referred to as “plane direction”). That is, the thickness in the surface direction of the elastic member satisfying the interval is not particularly limited as long as the thickness that can relieve the stress applied to the outer periphery of the electrolyte membrane by the elastic member is secured. However, from the viewpoint of absorbing the deformation of the film in the planar direction, the thickness is preferably 5 mm or more, and from the viewpoint of reducing the stack volume as much as possible, the thickness is preferably 20 mm or less. A more preferable thickness in the plane direction is 5 mm or more and 10 mm or less.

  In addition, in the description of the embodiment of the present invention, fluororubber is exemplified as the material of the elastic member, but the material of the elastic member is not limited to this, and functions as an elastic body in the operating environment of the fuel cell stack. Other materials can be used as long as they can be used. Examples of the other material include silicone rubber.

  Furthermore, in the above description, a solid polymer film having a hydrocarbon ionomer is exemplified as the electrolyte film, but the electrolyte film provided in the fuel cell stack of the present invention is not limited to this. Other specific examples of the electrolyte membrane include a solid polymer membrane having a perfluorosulfonic acid ionomer (for example, Nafion et al. (“Nafion” is a registered trademark of DuPont, USA)).

  Furthermore, in the said description, although the form in which the 1st fixed member, the 2nd fixed member, and the elastic member were not formed integrally was illustrated, this invention is not limited to the said form. The first fixed member and elastic member in the first embodiment, or the second fixed member and elastic member in the first embodiment, or the first fixed member and elastic member in the second embodiment, or the first The second fixed member and elastic member in the second embodiment, or the first fixed member and elastic member in the third embodiment, the space securing portion and the elastic member in the third embodiment, or the second fixed member and elastic member in the third embodiment. 2 The fixed member and the elastic member may be integrally formed. Even in this form, if the space securing part and the elastic member are provided in the single cell, the elastic member can function as an elastic body even in an environment where compression pressure is applied. Damage can be reduced.

  In addition, although the form by which the anode diffusion layer and the cathode diffusion layer were provided in the single cell was illustrated so far, the single cell with which the fuel cell stack of this invention is provided is not limited to the said form. In addition to the illustrated form, it is possible to adopt a form in which the anode diffusion layer and / or the cathode diffusion layer are not provided. When the anode diffusion layer is not provided, hydrogen may be supplied to the anode catalyst layer, and when the cathode diffusion layer is not provided, oxygen may be supplied to the cathode catalyst layer. Further, heretofore, a single cell provided with a first separator and a second separator (hereinafter collectively referred to simply as “separator”) in a form provided with a reaction gas flow path has been exemplified. The separator provided is not limited to this form. When the reaction gas channel is not provided in the first separator, for example, hydrogen is supplied to an anode diffusion layer composed of a sintered metal or the like (or an anode catalyst layer when no anode diffusion layer is provided). In the case where the second separator is not provided with a reaction gas flow path, for example, oxygen is supplied to a cathode diffusion layer made of sintered metal or the like (or a cathode catalyst layer if no cathode diffusion layer is provided). The form may be used.

It is sectional drawing which shows a part of single cell with which the fuel cell stack of this invention concerning 1st Embodiment is equipped. It is the schematic which shows the example of a form of a fuel cell stack provided with the single cell concerning 1st Embodiment. It is sectional drawing which shows a part of single cell with which the fuel cell stack of this invention concerning 2nd Embodiment is equipped. It is sectional drawing which shows a part of single cell with which the fuel cell stack of this invention concerning 3rd Embodiment is equipped.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolyte membrane 2 Anode 2a Anode catalyst layer (1st catalyst layer)
2b Anode diffusion layer 3 Cathode 3a Cathode catalyst layer (second catalyst layer)
3b Cathode diffusion layer 4 MEA
DESCRIPTION OF SYMBOLS 5 1st separator 6 2nd separator 7, 8 Reaction gas flow path 9 Elastic member 10, 12, 14 1st fixed member 11, 13 2nd fixed member 10x, 11x, 12x, 15 Space securing part 16, 17, 18 Structure Body 20, 30, 40 Single cell (laminated body)
100 Fuel cell stack

Claims (2)

An electrolyte membrane, a first catalyst layer provided at the center of one surface of the electrolyte membrane, a second catalyst layer provided at the center of the other surface of the electrolyte membrane, and an outer edge portion on the one side of the electrolyte membrane And a second shaped member disposed on the outer edge of the other side of the electrolyte membrane, and a first layer laminated on the one side of the structure. A separator having a first separator and a second separator stacked on the other side of the structure,
An elastic member is provided between the first shaped member and the electrolyte membrane, and between the second shaped member and the electrolyte membrane,
A space securing portion for securing a space for filling the elastic member is provided between the first shaped member, the second shaped member, and / or between the first shaped member and the second shaped member. And
Wherein the laminating direction of the laminate in a plane direction parallel to the normal direction state, and are spaced 5mm or 20mm or less between the outer edge and the space reserved portion of the electrolyte membrane,
When the thickness of the electrolyte membrane when dry is T, the length of the stacking direction of the space securing unit is characterized in der Rukoto than 200T less 2.5T, the fuel cell stack. The fuel cell stack according to claim 1, wherein the elastic member is made of fluorine rubber or silicone rubber.

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