JP2014120248A - Fuel cell and method for manufacturing fuel cell - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a fuel cell with a simple structure, which defines a distance between separators while exhibiting a seal function.SOLUTION: A fuel cell 100 comprises: a membrane electrode gas diffusion layer junction 20; a seal member 40 arranged on a periphery of the membrane electrode gas diffusion layer junction; and a pair of separators 30 pinching the membrane electrode gas diffusion layer junction and the seal member. The seal member comprises: a core layer 41 formed of a thermoplastic resin; and a pair of skin layers 42 formed on face surfaces on both sides getting contact with a pair separators of the core layer, and adhering pair of separators to the core layer. A thickness of the seal member before pinched by a pair of separators, is thicker than a thickness of the membrane gas diffusion layer junction before pinched by a pair of separators. A total thickness of a pair skin layers of the seal member before pinched by a pair of separators, is larger than a decrement of the thickness of the membrane electrode gas diffusion layer junction, generated when the membrane electrode gas diffusion layer junction is pinched by a pair of separators.

Description

  The present invention relates to a fuel cell and a method for manufacturing the fuel cell.

  In general, a fuel cell is a membrane electrode assembly (hereinafter referred to as a membrane electrode assembly), which is a power generator in which electrodes (catalyst electrodes) carrying a catalyst for promoting a fuel cell reaction are disposed on both surfaces of an electrolyte membrane. , MEA). On both surfaces of the MEA, gas diffusion layers for diffusing the reaction gas and spreading it over the entire catalyst electrode are arranged. An MEA in which a gas diffusion layer is disposed (a membrane electrode diffusion layer assembly (hereinafter referred to as MEGA)) is sandwiched between a pair of separators. On the outer periphery of the MEGA between the pair of separators, a seal portion for suppressing leakage of the reaction gas (so-called cross leak) and electrical short circuit between the electrodes is formed.

  Patent Document 1 includes an MEA, a gas diffusion layer, a first seal portion formed along the end surface of the MEA, and a second seal portion formed along the end surface of the gas diffusion layer. A fuel cell is described. In this fuel cell, the MEA, the gas diffusion layer, and the separator are arranged such that the gas diffusion layer is arranged on both sides of the MEA, and the separator is arranged on the surface of the gas diffusion layer opposite to the side facing the MEA. It has the structure laminated | stacked on. The first seal portion has an effective seal portion (lip portion) that suppresses gas leakage to the outside between the first seal portion and the separator. The second seal portion is formed integrally with the diffusion layer so as to be in close contact with the lamination surface of the MEA and the lamination surface of the separator after lamination before lamination. In addition, the shape of the second seal portion before stacking is a shape in which the thickness along the stacking direction of the fuel cell is larger than the thickness of the gas diffusion layer, and the second seal portion is formed between the MEA and the separator during stacking. By being sandwiched and deformed and closely contacting the MEA and the separator, leakage of gas from the gas diffusion layer is suppressed. The shape of the first seal portion before lamination is also larger than the thickness of the MEA and the gas diffusion layer laminated, and is deformed by being sandwiched between the separators during lamination. In close contact with the separator, leakage of gas to the outside between the separator is suppressed.

JP 2007-329084 A

  In a conventional fuel cell such as the fuel cell described in Patent Document 1, in order to bring the separator into close contact with the gas diffusion layer and close contact with the MEA, the MEA and the MEA A structure in which a gas diffusion layer is sandwiched between a pair of separators is common. In such a structure, a constant load is applied to the MEGA regardless of the thickness of the MEA (MEGA) on which the gas diffusion layer is disposed. It becomes difficult to define the thickness in the direction, that is, the interval between the separators to be constant. Moreover, in patent document 1, it is a structure which has two seal parts, and was not enough at the point of cost and mass-productivity. For this reason, there has been a demand for a technique that has a simpler structure, can exhibit a sealing function, and can define the interval between separators. Moreover, cost reduction and improvement in mass productivity have been desired.

  SUMMARY An advantage of some aspects of the invention is to solve at least a part of the problems described above, and the invention can be implemented as the following forms.

(1) According to one aspect of the present invention, a fuel cell is provided. The fuel cell includes a membrane electrode gas diffusion layer assembly; a seal member disposed on an outer periphery of the membrane electrode gas diffusion layer assembly; a pair of sandwiching the membrane electrode gas diffusion layer assembly and the seal member And a separator. The seal member includes a core layer made of a thermoplastic resin; a pair of skin layers formed on the surface layers on both sides of the core layer in contact with the pair of separators, and bonding the pair of separators to the core layer; Comprising. The thickness of the sealing member before being sandwiched between the pair of separators is larger than the thickness of the membrane electrode gas diffusion layer assembly before being sandwiched between the pair of separators, and is sandwiched between the pair of separators. The total thickness of the pair of skin layers of the seal member before being formed is that of the membrane electrode gas diffusion layer assembly generated when the membrane electrode gas diffusion layer assembly is sandwiched between the pair of separators. Greater than the thickness reduction. According to the fuel cell of this embodiment, when the membrane electrode gas diffusion layer assembly and the seal member are sandwiched and integrally formed by the pair of separators, the membrane electrode changes depending on the load applied through the pair of separators The thickness of the skin layer of the sealing member can be changed and absorbed in accordance with the change of the thickness of the gas diffusion layer assembly. Further, dimensional tolerances such as a dimensional tolerance of the membrane electrode gas diffusion layer assembly and a dimensional tolerance of members constituting the membrane electrode gas diffusion layer assembly can be absorbed by changing the thickness of the skin layer of the seal member. As a result, the magnitude of the load is reduced until the distance between the separators becomes a dimension defined by the thickness of the core layer (strictly, the thickness of the skin layer required for adhesion between the core layer and the separator and the core layer). A load can be applied without prescribing. As a result, it is possible to easily integrally form fuel cells that are defined so that the distance between the pair of separators is constant. Further, when the membrane electrode gas diffusion layer assembly and the seal member are sandwiched and integrally formed by a pair of separators, the membrane electrode gas diffusion layer assembly contacts the pair of separators, and the membrane electrode gas diffusion layer junction Since the load is reliably applied to the body via the pair of separators, the bondability between the membrane electrode gas diffusion layer assembly and the pair of separators can be improved. Thereby, it is possible to suppress the deterioration of the power generation characteristics due to the bondability between the membrane electrode gas diffusion layer assembly and the pair of separators, and to improve the power generation characteristics.

(2) In the fuel cell of the above aspect, the membrane electrode gas diffusion layer bonding when the volume of at least one skin layer of the seal member before being sandwiched between the pair of separators is sandwiched between the pair of separators You may make it become larger than the volume of the space between a body and the said sealing member. According to the fuel cell of this embodiment, since there is no gap between the membrane electrode gas diffusion layer assembly and the sealing member, the membrane electrode gas diffusion layer assembly is suppressed from swelling / shrinking, and the membrane generated by swelling / shrinking Deterioration of the electrode gas diffusion layer assembly can be suppressed, and characteristic deterioration such as cross leakage can be suppressed.

  The present invention can also be realized in various forms other than the fuel cell. For example, it is realizable with forms, such as a manufacturing method of a fuel cell, a fuel cell system provided with a fuel cell, a vehicle provided with a fuel cell.

It is a cross-sectional schematic diagram which shows schematic structure of the fuel cell which comprises a fuel cell as 1st Embodiment. It is explanatory drawing shown about the manufacturing method of a fuel cell. It is explanatory drawing which shows the outline of the preparation process of the fuel cell by the manufacturing method of the fuel cell shown in FIG. It is a graph which shows the relationship between the load at the time of pressurizing with respect to MEGA to a compression direction, and a film thickness. It is a cross-sectional schematic diagram which shows a part of schematic structure of a fuel cell as 2nd Embodiment. It is explanatory drawing which shows the characteristic on manufacture of the fuel battery cell shown in FIG.

A. First embodiment:
FIG. 1 is a schematic cross-sectional view showing a schematic configuration of a fuel cell constituting a fuel cell as a first embodiment. The fuel cell 100 is a solid polymer fuel cell that generates electric power upon receiving a supply of a fuel gas (for example, hydrogen) and an oxidant gas (for example, oxygen) as a reaction gas. The fuel cell usually has a stack structure in which a plurality of fuel cells 100 are stacked.

  The fuel cell 100 includes a MEGA (membrane electrode gas diffusion layer) in which an anode side gas diffusion layer 22a is disposed on one surface of an MEA (membrane electrode assembly) 10 and a cathode side gas diffusion layer 22c is disposed on the other surface. (Joined body) 20, a seal member 40 disposed on the outer peripheral portion of MEGA 20, and an anode-side separator 30 a and a cathode-side separator 30 c that sandwich MEGA 20 and seal member 40. Note that the anode-side separator 30a and the cathode-side separator 30c are also simply referred to as “separator 30” unless otherwise distinguished.

  The MEA 10 includes an anode-side catalyst layer 12a and a cathode-side catalyst layer 12c in which a catalyst for promoting a fuel cell reaction is supported on both surfaces of an electrolyte membrane 11 that is a solid polymer thin film that exhibits good proton conductivity in a wet state. Is a power generator provided. The electrolyte membrane 11 can be composed of, for example, a fluorine ion exchange membrane such as Nafion (registered trademark). The anode side catalyst layer 12a and the cathode side catalyst layer 12c are formed, for example, by applying a catalyst ink containing a carbon carrier carrying platinum (Pt) or the like and an ionomer having proton conductivity to the electrolyte membrane 11. be able to.

  The MEGA 20 includes an anode side gas diffusion layer 22a on the surface side where the anode side catalyst layer 12a of the MEA 10 is provided, and a cathode side gas diffusion layer 22c on the surface side where the cathode side catalyst layer 12c is provided. . The anode-side gas diffusion layer 22a and the cathode-side gas diffusion layer 22c are made of a material having gas permeability, conductivity, and spring properties. As the material for the gas diffusion layer, for example, carbon paper, carbon cloth, paper made of stainless fiber, or the like is used.

  The pair of separators 30 sandwich the MEGA 20 and the seal member 40. The separator 30 is formed of a member having gas barrier properties and electronic conductivity, in this embodiment, press-molded stainless steel. The separator 30 can also be formed of a thin plate member formed of a metal such as titanium or a titanium alloy, or a carbon member such as dense carbon.

  The seal member 40 is a member for preventing a cross leak and an electrical short circuit between the electrodes. The seal member 40 has a three-layer structure including at least a pair of skin layers 42 on both surfaces of the core layer 41 on the separator 30 side. However, in the illustrated example, the surface of the core layer 41 is covered with a skin layer 42. This point will be described later. The core layer 41 is made of a thermoplastic resin and has a property that the structure does not change even under temperature conditions when forming the fuel cell 100 as described later. The skin layer 42 has a high adhesiveness to other substances in order to adhere the core layer 41 and the separator 30 to ensure a sealing property, and is softened under temperature conditions when the fuel potential cell 100 is formed. It has the property of low viscosity and melting point. The skin layer 42 can be configured using various materials such as a thermoplastic resin, a thermosetting resin, and an elastomer. In the present embodiment, polypropylene is used as the core layer 41. In addition, Admer (registered trademark), which is a modified polyolefin, is used as the skin layer 42.

  Although not shown, the fuel gas flow path is between the anode side gas diffusion layer 22a and the anode side separator 30a, and the oxidant gas flow path is between the cathode side gas diffusion layer 22c and the cathode side separator 30c. Are formed respectively. The fuel gas channel is a hydrogen gas channel, and the oxidant gas channel is an oxygen gas channel.

  FIG. 2 is an explanatory view showing a method for manufacturing a fuel cell. As a premise, first, the MEGA 20, the sealing member 40, the anode side separator 30a and the cathode side separator 30c are prepared. In the MEGA 20, for example, the cathode side diffusion layer 22c is disposed on the surface of the cathode side catalyst layer 12c of the MEA 10, and the anode side gas diffusion layer 22a is disposed on the surface of the anode side catalyst layer 12a. It is produced by thermocompression bonding at a temperature. For example, the MEA 10 applies a catalyst ink produced by mixing a carbon carrier carrying platinum and an ionomer in a solvent to both sides of the electrolyte membrane 11 to form a cathode side catalyst layer 12c and an anode side catalyst layer 12a. It is produced by forming. In addition, as the sealing member 40, a member having a thickness Yar before manufacturing the fuel cell (hereinafter referred to as “before cell formation”) larger than the thickness Xr of the MEGA 20 before cell formation is used. Further, as the sealing member 40, the core layer 41 has a thickness Yc smaller than the thickness Xr of the MEGA 20 before cell formation, and the skin layer 42 has a thickness Ysr with respect to the thickness Xr of the MEGA 20 before cell formation. A member satisfying the relationship of 2 · Ysr> Xd is used for the subsequent reduction amount Xd (= Xr−Xs) of the thickness Xs. The condition of the thickness Ysr of the skin layer 42 will be further described later.

  Then, as shown in FIG. 2, the sealing member 40 is disposed on the outer periphery of the MEGA 20, and the MEGA 20 and the sealing member 40 are sandwiched between the anode-side separator 30a and the cathode-side separator 30c and thermocompression bonded, as shown in FIG. The fuel battery cell 100 is manufactured.

  FIG. 3 is an explanatory diagram showing an outline of a manufacturing process of a fuel cell by the method for manufacturing the fuel cell shown in FIG. As shown in FIG. 2, the anode-side separator 30a and the cathode-side separator 30c are placed on the MEGA 20 and the seal member 40 disposed between the anode-side separator 30a and the cathode-side separator 30c in a cell-forming temperature environment set in advance. Through the load. The cell forming temperature is set to a temperature lower than the softening temperature (melting point) of the core layer 41 of the sealing member 40 and higher than the softening temperature (melting point) of the skin layer 42. The temperature lower than the softening temperature of the core layer 41 is the sealing member 40 as a structure for defining the thickness Xs of the MEGA after cell formation, that is, the interval between the pair of separators 30, as will be described later. This is to make the structure of the core layer 41 unchanged during thermocompression bonding in order to make the core layer 41 function. The reason why the temperature is higher than the softening temperature of the skin layer 42 is to improve the contact property between the skin layer 42 and the separator 30 to improve the adhesiveness and the sealing property, and to improve the fluidity due to the softening. For example, when the melting point of polypropylene of the core layer 41 is 160 ° C. and the melting point of the admer of the skin layer 42 is 40 ° C., the cell formation temperature is set to 145 ° C. to 155 ° C.

  Note that the thickness Xs of the MEGA 20 after cell formation (the thickness Ya of the seal member 40) is set as follows, for example. FIG. 4 is a graph showing the relationship between load and film thickness when MEGA is pressed in the compression direction. As shown in FIG. 4, the film thickness of MEGA has an elastic characteristic that changes to a compressed thickness corresponding to the amount of strain corresponding to the load. Therefore, for example, if the load applied to the MEGA 20 at the time of thermocompression bonding is set to Fs, the strain amount corresponding to the set load Fs (the above reduction amount is calculated from the stress-strain curve of the MEGA 20 obtained by actual measurement in advance. (Corresponding) Xd is determined. The film thickness of the MEGA 20 after cell formation (film thickness after cell formation) Xs is set by subtracting the strain amount Xd obtained from the film thickness (film thickness before cell formation) Xr of the MEGA 20 before cell formation. The Conversely, if the film thickness Xs of the MEGA 20 after cell formation is determined, the corresponding load Fs and the decrease amount Xd are determined.

  In the initial stage of manufacturing the fuel cell, as shown in FIG. 3A, since the thickness Xr of the MEGA 20 is smaller than the thickness Yar of the seal member 40, no load is applied to the MEGA 20 and only the seal member 40 is applied. A load is applied, the interval between the pair of separators 30 is narrowed, and only the seal member 40 is compressed. At this time, since the cell forming temperature is higher than the melting point of the skin layer 42, the skin layer 42 of the sealing member 40 is softened under the cell forming temperature, and the members constituting the skin layer 42 flow under the compression load. Overflowing into the lateral space, the thickness of the skin layer 42 becomes smaller according to the load.

  3B, when the seal member 40 is compressed until the thickness of the seal member 40 becomes equal to the thickness Xr of the MEGA 20, the pair of separators 30 are in contact with the MEGA 20, and a load is also applied to the MEGA 20. The MEGA 20 is compressed with a strain amount corresponding to the applied load, and the skin layer 42 is compressed by the seal member 40 so as to absorb the compression strain amount of the MEGA 20.

  Here, even if the load applied to the MEGA 20 and the seal member 40 is increased via the pair of separators 30 by the core layer 41 of the seal member 40, the reduction amount of the interval between the pair of separators 30 is drastically reduced. A state that does not fluctuate, a so-called “don't care” state occurs. Therefore, it is possible to simply apply a load between the pair of separators 30 without managing the magnitude of the load until the gap between the separators 30 is almost constant. In this case, as shown in FIG. 3C, the thickness Ya of the sealing member 40 is equal to the thickness Yc of the core layer 41 and a pair of skin layers required for adhesion between the separator 30 and the core layer 41. The sum of the thicknesses Ys of 42 (2 · Ys). However, since the thickness Ys of the skin layer 42 required for adhesion is very small compared to the thickness Yc of the core layer 41, the thickness Ya of the seal member 40 is considered to be approximately the thickness Yc of the core layer 41. In practice, there is no problem.

  Then, as shown in FIG. 3C, the cell-forming temperature is lowered while maintaining the load in the “don't stick” state. At this time, even if the load is released, the interval between the separators 30 does not change, and the load is released if the temperature is lowered to a temperature at which adhesion by the skin layer 42 can be secured. Accordingly, it is possible to obtain the fuel cell 100 in which the distance between the pair of separators 30, that is, the thickness Xs of the MEGA 20 is defined by the thickness Ya of the seal member 40. The portion that flows due to the load of the skin layer 42 and overflows into the space is cured so as to cover the surface of the core layer 41.

  As described above, in the fuel cell 100 of the present embodiment, the seal member 40 having a thickness Yar larger than the thickness Xr of the MEGA 20 is disposed on the outer periphery of the MEGA 20 and is thermocompression bonded from both sides by the pair of separators 30. Thus, the MEGA 20 having the thickness Xs and the seal member 40 having the thickness Ya (= Xs) are sandwiched between the pair of separators 30 (see FIGS. 1 and 3C). The seal member 40 includes a core layer 41 that defines the structure of the seal member, and a skin layer 42 that ensures adhesion between the separator 30 and the cell inside after adhesion. In addition, the thickness Ysr of the skin layer 42 of the sealing member 40 before cell formation satisfies the relationship of 2 · Ysr> Xd with respect to the reduction amount Xd (= Xr−Xs) of the MEGA 20 due to cell formation. (See FIG. 2 and FIG. 3A). As a result, the change in the thickness of the MEGA compressed by thermocompression is absorbed by changing the thickness of the skin layer, and the thickness of the MEGA after thermocompression, that is, the interval between the separators after thermocompression is set. It is possible to define the seal member with a simple structure. Also, dimensional tolerances such as dimensional tolerances of MEGA components are absorbed by changing the thickness of the skin layer of the seal member, and the interval between the separators after thermocompression bonding is defined by a simple structure seal member. It becomes possible to do.

  In addition, since the load can be applied between the separators until the dong state is reached during thermocompression bonding, the load can be applied without defining the magnitude of the load. As a result, it becomes possible to produce a fuel cell in which the interval between the separators after thermocompression bonding is defined in a shorter time than when thermocompression bonding is performed with a constant load. As a result, mass productivity and cost reduction of the fuel battery cell can be achieved.

B. Second embodiment:
FIG. 5 is a schematic cross-sectional view showing a part of the schematic configuration of the fuel battery cell as the second embodiment. In the fuel cell 100B, the space AP corresponding to the space between the MEGA 20 and the seal member 40 of the fuel cell 100 shown in FIG. 1 is filled with the members constituting the skin layer 42 of the seal member 40. The point is different. The fuel cell 100B having this structure is also manufactured in the same manner as the fuel cell 100 of the first embodiment described with reference to FIGS. 2 and 3 except for the points described below.

  FIG. 6 is an explanatory view showing the manufacturing characteristics of the fuel battery cell shown in FIG. When this fuel cell 100B is manufactured, as shown in FIG. 6, the thickness Ysr of the skin layer 42 of the prepared seal member 40 is 2 · Ysr> Xd (= Xr−Xs) in the first embodiment. In addition to the first condition that satisfies the above relationship, the following condition is set. That is, the second condition is that the thickness Ysr of the skin layer 42 depends on the load at the time of cell formation in the thickness (Ysr−Ys) portion excluding the thickness Ys portion of the skin layer 42 required for adhesion. The volume of the member that has flowed and overflowed from the skin layers 42 on both sides to the space Ap between the MEGA 20 and the seal member 40 can fill the space Ap (see FIG. 5). It must be a condition. Since the thickness Ys of the skin layer 42 required for adhesion is very small compared to the thickness Ysr (> Xd / 2) required from the first condition, the second condition is the thickness of the skin layer 42. Ysr may be of such a thickness that the volume of the member overflowing from the skin layers 42 on both sides into the space Ap can fill the space Ap. In this example, the thickness of the skin layer 42 on both sides of the seal member 40 to be prepared is set to a thickness that is larger than the volume of the space Ap. Note that the thickness of any one of the skin layers 42 may be set so as to be larger than the volume of the space AP. Further, when the overflow of the member from the skin layer 42 can be restricted only to the space AP, for example, when a means for shielding the outer side surface is provided, the volume of the skin layer 42 on both sides (strictly speaking, both sides It is also possible to set the thickness such that the volume excluding the volume corresponding to the thickness Ys required for bonding the skin layer 42 is equal to the volume of the space AP.

  As described above, the fuel battery cell 100B of the present embodiment, like the fuel battery cell 100 of the first embodiment, thereby changes the thickness of the MEGA compressed by thermocompression bonding to the thickness of the skin layer. The thickness of the MEGA after thermocompression bonding, that is, the interval between the separators after thermocompression bonding can be defined by a simple structure sealing member. Also, dimensional tolerances such as dimensional tolerances of MEGA components are absorbed by changing the thickness of the skin layer of the seal member, and the interval between the separators after thermocompression bonding is defined by a simple structure seal member. It becomes possible to do.

  Further, since a load can be applied between the separators until the dong state is reached during thermocompression bonding, the load can be applied without specifying the magnitude of the load. As a result, it becomes possible to produce a fuel cell in which the interval between the separators after thermocompression bonding is defined in a shorter time than when thermocompression bonding is performed with a constant load. As a result, mass productivity and cost reduction of the fuel battery cell can be achieved.

  Further, since the space between the MEGA 20 and the seal member 40 can be filled with the member of the skin layer 42, it is possible to restrict the electrolyte membrane 10 of the MEGA 20 from repeatedly swelling and shrinking due to power generation. As a result, deterioration of the MEGA 20 such as deterioration of the electrolyte membrane 10 due to swelling / shrinkage can be suppressed, and deterioration of characteristics such as cross leak can be suppressed.

C. Variations:

  In the above embodiment, polyethylene is used as the thermoplastic resin 41 constituting the core layer 41 of the seal member 40. In contrast, various thermoplastic resins such as polyethylene terephthalate, polyvinyl chloride, polypropylene, polyvinyl acetate, AS resin, ABS resin, and acrylic resin may be used. In the above embodiment, Admer is used as the acid-modified thermoplastic resin constituting the skin layer 42. On the other hand, acid-modified thermoplastic resins such as Modic (registered trademark), Nuclel (registered trademark), and Himiran (registered trademark) may be used. Further, instead of the acid-modified thermoplastic resin, a thermoplastic resin having a lower melting point than the thermosetting resin of the core layer 41 and having adhesiveness may be used. Further, various thermosetting resins having a melting point lower than that of the thermosetting resin of the core layer 41 such as epoxy resin, phenol resin, and polyester resin and having adhesive properties may be used. Further, various thermoplastic or thermosetting elastomer resins may be used.

  In the above embodiment, the fuel cell is a polymer electrolyte fuel cell. On the other hand, the fuel cell is not limited to the polymer electrolyte fuel cell, but may be other various types of fuel cells.

  The present invention is not limited to the above-described embodiments and modifications, and can be realized with various configurations without departing from the spirit thereof. For example, the technical features in the embodiments and the modifications corresponding to the technical features in each embodiment described in the summary section of the invention are to solve some or all of the above-described problems, or In order to achieve part or all of the effects, replacement or combination can be performed as appropriate. Further, if the technical feature is not described as essential in the present specification, it can be deleted as appropriate.

10 ... MEA
DESCRIPTION OF SYMBOLS 11 ... Electrolyte membrane 12a ... Anode side catalyst layer 12c ... Cathode side catalyst layer 20 ... MEGA
DESCRIPTION OF SYMBOLS 22 ... Gas diffusion layer 22a ... Anode side gas diffusion layer 22c ... Cathode side gas diffusion layer 33 ... Separator 33a ... Anode side separator 33c ... Cathode side separator 40 ... Seal member 41 ... Core layer 42 ... Skin layer 100 ... Fuel cell 100B ... Fuel battery cell Ap ... Space

Claims (4)

A fuel cell,
A membrane electrode gas diffusion layer assembly;
A seal member disposed on the outer periphery of the membrane electrode gas diffusion layer assembly;
A pair of separators sandwiching the membrane electrode gas diffusion layer assembly and the seal member;
With
The seal member is formed on a core layer made of a thermoplastic resin, and a pair of skin layers formed on the surface layers on both sides of the core layer in contact with the pair of separators, and bonding the pair of separators to the core layer. With
The thickness of the seal member before being sandwiched by the pair of separators is greater than the thickness of the membrane electrode gas diffusion layer assembly before being sandwiched by the pair of separators,
The total thickness of the pair of skin layers of the seal member before being sandwiched between the pair of separators is generated when the membrane electrode gas diffusion layer assembly is sandwiched between the pair of separators. A fuel cell, characterized in that it is larger than the thickness reduction of the gas diffusion layer assembly. The fuel cell according to claim 1, wherein
The space between the membrane electrode gas diffusion layer assembly and the seal member when the volume of at least one skin layer of the seal member before being sandwiched between the pair of separators is sandwiched between the pair of separators A fuel cell characterized by being larger than the volume. A fuel cell manufacturing method comprising:
(A) a membrane electrode gas diffusion layer assembly, a seal member disposed on an outer periphery of the membrane electrode gas diffusion layer assembly, and a pair of separators sandwiching the membrane electrode gas diffusion layer assembly and the seal member And a step of preparing
(B) The pair of separators are arranged on both sides of the membrane electrode gas diffusion layer assembly and the seal member, and the membrane electrode gas diffusion layer assembly and the seal member are interposed via the pair of separators at a predetermined temperature. Applying the load to the pair of separators and the membrane electrode gas diffusion layer assembly, and bonding the pair of separators and the seal member;
With
The seal member is formed on a core layer made of a thermoplastic resin, and a pair of skin layers formed on the surface layers on both sides of the core layer in contact with the pair of separators, and bonding the pair of separators to the core layer. With
The thickness of the seal member before being sandwiched by the pair of separators is greater than the thickness of the membrane electrode gas diffusion layer assembly before being sandwiched by the pair of separators,
The total thickness of the pair of skin layers of the seal member before being sandwiched between the pair of separators is generated when the membrane electrode gas diffusion layer assembly is sandwiched between the pair of separators. A method for producing a fuel cell, characterized in that it is larger than the thickness reduction amount of the gas diffusion layer assembly. A method of manufacturing a fuel cell according to claim 3,
In the step (b), the membrane electrode gas diffusion layer bonding when the skin layer of the sealing member softened at the temperature is caused to flow by a load applied to the skin layer and is sandwiched between the pair of separators A method of manufacturing a fuel cell, comprising a step of filling a space between a body and the seal member.

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