JP7181409B2 - FUEL BATTERY CELL AND METHOD FOR MANUFACTURING FUEL BATTERY CELL - Google Patents

Description

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

For example, as shown in Patent Document 1, a fuel cell includes a membrane electrode assembly (MEA), a pair of separators sandwiching the membrane electrode assembly, and a pair of separators and the membrane electrode assembly. and sealing members respectively interposed therebetween. A membrane electrode assembly comprises an electrolyte membrane, a pair of catalytic electrode layers and a pair of gas diffusion layers. Here, of the membrane electrode assembly, the portion where the catalyst electrode layer and the gas diffusion layer are formed is referred to as the "main body portion", and the electrolyte membrane or film projecting outward from the main body portion is referred to as the "overhanging portion". . The sealing member is, for example, an elastic body, a gasket, or the like.

The main body portion of the membrane electrode assembly is sandwiched between the reaction channel portions provided in the pair of separators to form a reaction region. The projecting portion of the membrane electrode assembly is sandwiched between sealing members provided on a pair of separators to form a sealing region. A fuel cell stack is configured by stacking a plurality of fuel cells and compressing the fuel cells with a predetermined clearance or load. When the fuel cell is compressed, the membrane electrode assembly is also compressed via the sealing member, but it is desirable that the overhang between the sealing area and the reaction area is not wrinkled.

FIG. 10A is a cross-sectional view of a main part showing the assembly of a conventional fuel cell. FIG. 10B is a cross-sectional view of main parts showing the state of FIG. 10A when compressed. FIG. 11A is a fragmentary cross-sectional view showing another conventional fuel cell assembly. FIG. 11B is a cross-sectional view of main parts showing the state of FIG. 11A when compressed.

As shown in FIG. 10A, a conventional fuel cell 100 includes a separator 101, a separator 102, and a membrane electrode assembly 103. As shown in FIG. The separator 101 arranged on the lower side has a reaction channel portion 106 through which the reaction fluid flows, and a convex bead 108 on which a sealing member 104 is arranged. The separator 102 arranged on the upper side has a reaction channel portion 107 through which the reaction fluid flows, and a convex bead 109 on which the sealing member 105 is arranged.

When assembling the fuel cell 100 , first, the membrane electrode assembly 103 is arranged on the lower separator 101 . A body portion 111 of the membrane electrode assembly 103 is placed on the reaction channel portion 106 , and an overhang portion (electrolyte membrane or film) 112 is placed on the sealing member 104 . The protruding portion 112 is a portion that protrudes outward from the main body portion 111 . At this time, between the sealing member 104 and the reaction flow channel section 106, the overhanging section 112 is bent 120 by its own weight.

As shown in FIG. 10B, when a force is applied in the direction to bring the separators 101 and 102 closer to each other, the convex beads 108 and 109 respectively contract in the height direction in the sealing region, and the sealing members 104 and 105 also contract. Also, in the reaction region, the gas diffusion layer of the main body 111 of the membrane electrode assembly 103 contracts. As a result, the height position of the protruding portion 112 in the sealing area and the height position of the electrolyte membrane in the reaction area are substantially the same. On the other hand, in projecting portion 112, wrinkles 120A may occur between the sealing area and the reaction area.

As shown in FIG. 11A, another conventional fuel cell 200 includes a separator 201, a separator 202, and a membrane electrode assembly 203. As shown in FIG. The separator 201 arranged on the lower side has a seal member 204 and a reaction channel portion 206 through which the reaction fluid flows. The sealing member 204 is a lip gasket that tapers toward its tip. The upper separator 202 has a seal member 205 and a reaction flow path portion 207 through which the reaction fluid flows.

When assembling the fuel cell 200 , first, the membrane electrode assembly 203 is arranged on the separator 201 . A main body portion 211 of the membrane electrode assembly 203 is arranged on the reaction channel portion 206 , and an overhang portion (electrolyte membrane or film) 212 is arranged on the sealing member 204 . At this time, between the sealing member 204 and the reaction flow path section 206, the overhanging section 212 is bent 220 by its own weight.

As shown in FIG. 11B, when a force is applied in a direction to bring the separators 201 and 202 closer together, the sealing members 204 and 205 shrink in the height direction in the sealing region. Also, in the reaction region, the gas diffusion layer of the main body 211 of the membrane electrode assembly 203 contracts. On the other hand, in projecting portion 212, wrinkles 220A may occur between the sealing area and the reaction area.

Japanese Patent Application Laid-Open No. 2009-37960

It is desirable that the protruding portions (electrolyte membranes or films protruding to the outside of the main body portion) 112, 212 protruding outward from the membrane electrode assemblies 103, 203 are not wrinkled. However, in both the fuel cells 100 and 200, deflections 120 and 220 are generated in the membrane electrode assemblies 103 and 203 during assembly, and wrinkles 120A and 220A are generated during compression due to the deflections 120 and 220. Then it is inferred.

Moreover, since the projecting portions 112 and 212 projecting outward from the membrane electrode assemblies 103 and 203 are made of a thin and soft material, they are likely to be bent or wrinkled. Furthermore, when a lip gasket having a large height such as the sealing member 204 is used, the fact that the lip gasket is set high by the compression margin also causes the deflection of the projecting portions 112 and 212 .

The present invention was invented to solve such problems, and a fuel cell and a fuel cell manufacturing method capable of eliminating or reducing wrinkles in the electrolyte membrane or film protruding outside the membrane electrode assembly. The task is to provide

The present invention for solving the above-mentioned problems is a one-side separator provided with a seal member arranged in a flat arrangement portion and a reaction channel portion through which a reaction gas flows, and a seal member arranged in the arrangement portion. and a separator on the other side provided with a reaction channel portion through which a reaction gas flows, and a membrane electrode assembly disposed between the separator on the one side and the separator on the other side via the seal member, and a reaction region is formed by sandwiching the main body of the membrane electrode assembly between the reaction channel portions, and the electrolyte membrane or film protruding from the main body is sandwiched between the sealing members. The contact surface of the reaction channel portion of the one-side separator with which the main body portion of the membrane electrode assembly abuts is placed more than the placement surface of the placement portion of the one-side separator. It is characterized by being set on a side away from the membrane electrode assembly.

In addition, the present invention provides a one-side separator having a reaction channel portion through which a reaction gas and a sealing member arranged in an arrangement portion formed flat, and a sealing member arranged in the arrangement portion and a reaction gas circulating. a preparation step of preparing the other side separator having a reaction channel portion and a membrane electrode assembly; disposing the membrane electrode assembly on the one side separator; above the reaction channel portion of the one-side separator, and placing an electrolyte membrane or film projecting from the main body portion on the seal member of the one-side separator; The other side separator is arranged on the membrane electrode assembly, the main body portion of the membrane electrode assembly is sandwiched between the reaction channel portions to form a reaction region, and the electrolyte membrane is sandwiched between the sealing members. or a step of arranging a separator on the other side to sandwich a film to form a seal region; setting a contact surface of the reaction channel portion with which the main body portion of the membrane electrode assembly abuts on a side farther from the membrane electrode assembly than the arrangement surface of the arrangement portion of the one-side separator; Characterized by

With such a configuration, it is possible to reduce the difference in height of the projecting portion (electrolyte membrane or film) during assembly between the sealing region and the reaction region. As a result, it is possible to eliminate or reduce the bending of the projecting portion during assembly, and it is possible to eliminate or reduce the wrinkling of the projecting portion of the membrane electrode assembly even after compression.

According to the fuel cell and the fuel cell manufacturing method of the present invention, it is possible to eliminate or reduce the wrinkles of the electrolyte membrane or film protruding outside the membrane electrode assembly.

1 is a cross-sectional view of a main part showing a fuel cell according to Example 1. FIG. 1 is an exploded cross-sectional view of a main part showing a fuel cell according to Example 1. FIG. FIG. 2 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Example 1; FIG. 4 is an exploded cross-sectional view of a main part of a fuel cell according to Modification 1 of Embodiment 1; FIG. 4 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Modification 1 of Embodiment 1; FIG. 8 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Modification 2 of Embodiment 1; FIG. 5 is a cross-sectional view of a main part showing a fuel cell according to Example 2; FIG. 5 is an exploded cross-sectional view of a main part showing a fuel cell according to Example 2; FIG. 10 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Example 2; FIG. 5 is a cross-sectional view of a main part showing a conventional fuel cell when assembled. FIG. 10B is a cross-sectional view of a main part showing the state of FIG. 10A when compressed; FIG. 10 is a cross-sectional view of a main part showing another conventional fuel cell assembly. FIG. 11B is a cross-sectional view of a main part showing the state of FIG. 11A when compressed;

As shown in FIG. 1 , a fuel cell 1 according to this embodiment includes a separator 2 on one side, a separator 3 on the other side, and a membrane electrode assembly (MEA: Membrane Electrode Assembly) 4 . The one-side separator 2 includes a seal member 6 arranged in a flat arrangement portion 5 and a reaction flow path portion 7 through which a reaction gas flows. The other side separator 3 includes a seal member 9 arranged in the arrangement portion 8 and a reaction channel portion 10 through which the reaction gas flows.

The membrane electrode assembly 4 is arranged between the separator 2 on one side and the separator 3 on the other side with sealing members 6 and 9 interposed therebetween, respectively. The membrane electrode assembly 4 is composed of an electrolyte membrane 11, a pair of catalyst electrode layers (not shown), and a pair of gas diffusion layers 12,12. A thick portion composed of the electrolyte membrane 11, the pair of catalyst electrode layers, and the pair of gas diffusion layers 12, 12 is referred to as a "main body portion 13", and the electrolyte membrane 11 projecting outward from the main body portion 13 is referred to as a "protruding portion 14". and The projecting portion 14 may be formed of a film.

The body portion 13 of the membrane electrode assembly 4 is sandwiched between the reaction channel portions 7 and 10 to form a reaction region 21, and the projecting portion 14 is sandwiched between the seal members 6 and 9 to form a seal region 22. is doing. The contact surface 17b of the reaction channel portion 7 of the one-side separator 2 that contacts the main body portion 13 of the membrane electrode assembly 4 is set at a position lower than the placement surface 5a of the placement portion 5 of the one-side separator 2. there is In other words, the contact surface 17b is set on the side farther from the membrane electrode assembly 4 than the arrangement surface 5a of the separator 2 on one side.

As shown in FIG. 3 , in the fuel cell and the fuel cell manufacturing method of the present embodiment, the abutment surface 17 b that abuts on the main body portion 13 of the membrane electrode assembly 4 is positioned on the placement portion 5 of the one-side separator 2 . It is set at a position lower than the placement surface 5a. As a result, when the membrane electrode assembly 4 is arranged on the separator 2 on one side, the projecting portion 14 (electrolyte membrane 11 or film) can be substantially flattened. Also, the displacement of the projecting portion 14 in the height direction can be reduced even during compression. As a result, when assembling the fuel cell 1, the bending of the projecting portion 14 between the reaction area 21 and the sealing area 22 can be eliminated or reduced, and even after compression, wrinkles of the projecting portion 14 can be prevented. can be eliminated or reduced. Examples will be described in detail below.

[Example 1]
As shown in FIG. 1, the fuel cell 1 is a member that generates electricity through a chemical reaction between hydrogen (fuel gas) supplied from the anode side and oxygen (oxidizing gas) supplied from the cathode side. The fuel gas and the oxidizing gas are also collectively referred to as "reactant gas". A fuel cell stack is formed by stacking a plurality of fuel cells 1 and compressing adjacent fuel cells 1, 1 with a predetermined clearance or load.

The one-side separator 2 is a plate-like member arranged below the membrane electrode assembly 4 in this embodiment. The one-side separator 2 has an arrangement portion 5 and a reaction channel portion 7 . The arrangement portion 5 is a portion where the seal member 6 is arranged, and is formed flat without a convex bead. The arrangement portion 5 is formed on the surface of the one-side separator 2 facing the membrane electrode assembly 4 . Although the arrangement portion 5 has a flat shape without a convex bead or the like in this embodiment, a groove or the like may be formed in a part of the arrangement portion 5 within a range where the sealing member 6 can be arranged flat.

The sealing member 6 is made of an elastic material, and is a flat gasket having a rectangular cross section in this embodiment. The sealing member 6 may be made of an elastic material such as ethylene propylene diene rubber (EPDM), silicone rubber (VMQ), fluororubber (FKM), polyisobutylene (PIB), or the like.

The seal member 6 can be formed integrally with the one-side separator 2 , or can be formed by forming the seal member 6 and then attaching the seal member 6 to the one-side separator 2 . Alternatively, the sealing member 6 may be integrally formed with a resin reinforcing body with an adhesive and attached to the separator 2 on one side. The shape of the seal member 6 may be set appropriately, but in this embodiment, it is preferable that the contact surface 6a with which the projecting portion 14 (electrolyte membrane 11 or film) contacts is flat.

A plurality of channel grooves 17 are formed in the reaction channel portion 7 to diffuse the reaction gas widely in the reaction region. A plurality of abutment surfaces 17b that abut on the body portion 13 of the membrane electrode assembly 4 are formed between the adjacent flow channels 17,17. The contact surfaces 17b are formed at the same height position and are parallel to the placement surface 5a of the placement portion 5. As shown in FIG. The contact surface 17b is set to be lower than the placement surface 5a of the placement portion 5 in the thickness direction of the electrolyte membrane 11 (the side away from the electrolyte membrane 11).

The other side separator 3 is a plate-like member arranged on the upper side of the membrane electrode assembly 4 in this embodiment. The other side separator 3 has an arrangement portion 8 and a reaction channel portion 10 . The placement portion 8 is a portion where the sealing member 9 is placed, and is formed flat without a convex bead. The placement portion 8 is formed on the surface facing the membrane electrode assembly 4 . Although the placement portion 8 is flat in this embodiment, a groove or the like may be formed in a portion of the placement portion 8 .

The sealing member 9 is made of an elastic material, and in this embodiment is a lip gasket that tapers toward its tip. The elastic material of the sealing member 9 is the same as that of the sealing member 6 . Also, the molding method of the sealing member 9 and the other side separator 3 is the same as that of the sealing member 6 . The shape of the sealing member 9 is not particularly limited as long as it can be sealed so that the reaction gas does not leak.

A plurality of channel grooves 18 are formed in the reaction channel section 10 for widely diffusing the reaction gas in the reaction region. A plurality of abutment surfaces 18b that abut on the body portion 13 of the membrane electrode assembly 4 are formed between the adjacent flow channels 18,18. The contact surfaces 18b are formed at the same height position and parallel to the placement surface 8a of the placement portion 8. As shown in FIG. The contact surface 18b is set to be at a position lower than the placement surface 8a of the placement portion 8 in the thickness direction of the electrolyte membrane 11 (on the side close to the electrolyte membrane 11). In this embodiment, the bottom surface 18a of the channel groove 18 is formed between the placement surface 8a and the contact surface 18b.

The thickness of the body portion 13 of the membrane electrode assembly 4 is sufficiently larger than the thickness of the projecting portion 14 . The projecting portion 14 is formed of the electrolyte membrane 11 or film.

The body portion 13 of the membrane electrode assembly 4 is sandwiched between the contact surface 17 b of the reaction channel portion 7 and the contact surface 18 b of the reaction channel portion 10 . Thereby, a reaction region 21 is formed in which the chemical reaction of the reaction gas is promoted. Also, the protruding portion 14 of the membrane electrode assembly 4 is sandwiched between the sealing members 6 and 9 . Thereby, a seal region 22 is formed in which the reactant gas is sealed. The projecting portion 14 (electrolyte membrane 11 or film) is positioned at approximately the same height between the reaction area 21 and the sealing area 22 . That is, the projecting portion 14 is substantially parallel to the arrangement portion 5 of the one-side separator 2 between the reaction region 21 and the sealing region 22 .

As shown in FIG. 2, the thickness of the sealing member 6 arranged on the one-side separator 2 before assembly is t1, and the crushing margin of the sealing member 6 arranged on the one-side separator 2 is _t1C . Further, the height from the contact surface 17b of the reaction channel portion 7 of the one-side separator 2 to the placement surface 5a of the placement portion 5 of the one-side separator 2 is t2.

Also, let T _GDL be the thickness dimension of the gas diffusion layer 12 disposed on the separator 2 side before assembly, and T _C be the compression margin dimension of the gas diffusion layer 12 . Also, the height dimension from the bottom surface 17a of the channel groove 17 to the contact surface 17b is t3. Also, the height dimension from the bottom surface 17a of the channel groove 17 to the placement surface 5a of the placement portion 5 is t4. At this time, in this embodiment, each dimension is set so as to satisfy the following formula (1).

(t1-t1 _C )+t2=(T _GDL -T _C ) Equation (1)

Since it is difficult to design the projecting portion 14 to be flat, each dimension may be set so as to satisfy the following formula (2) as long as the chemical reaction of the reactive gas is promoted.

(t1-t1 _C )+t2=(T _GDL -T _C )×α Equation (2)
α=0.8 to 1.2

Further, let t6 be the height dimension from the bottom surface 18a to the contact surface 18b of the channel groove 18 of the other separator 3, t7 be the height dimension from the placement surface 8a to the bottom surface 18a of the placement portion 8, and t8 is the height dimension from the arrangement surface 8a to the contact surface 18b. Also, let t10 be the thickness dimension of the sealing member 9 arranged on the other side separator 3 before assembly, and t10c be the crushing margin of the sealing member 9 arranged on the other side separator 3 . At this time, in this embodiment, each dimension is set so as to satisfy the following formulas (3) and (4).

t2≦t4<t8 Formula (3)
t2<t7≦t8 Equation (4)

The above formulas (1), (2), (3) and (4) are examples, and the dimensions of each part can be designed as appropriate. For example, the heights t3 and t6 of the channel grooves 17 and 18 may be appropriately set according to the fluidity of the reactant gas (hydrogen, oxygen) and cooling water and the compressibility of the gas diffusion layer 12 .

Next, a method for manufacturing the fuel cell according to this embodiment will be described. In the fuel cell manufacturing method according to the present embodiment, a preparation step, a membrane electrode assembly placement step, a second side separator placement step, and a compression step are performed.

As shown in FIG. 2, the preparation step is a step of preparing the one side separator 2, the other side separator 3 and the membrane electrode assembly 4 described above. As shown in FIG. 3 , the membrane electrode assembly arranging step is a step of arranging the membrane electrode assembly 4 on the one side separator 2 . In the membrane electrode assembly placement step, the body portion 13 of the membrane electrode assembly 4 is placed on the contact surface 17 b of the reaction channel portion 7 and the overhang portion 14 is placed on the contact surface 6 a of the seal member 6 . At this time, the height position of the protrusion 14 (electrolyte membrane 11 or film) can be kept substantially constant.

The other side separator placement step is a step of placing the other side separator 3 on the membrane electrode assembly 4 . In the step of arranging the separator on the other side, the contact surface 18b of the reaction channel portion 10 is brought into contact with the body portion 13 of the membrane electrode assembly 4, and the overhanging portion 14 is placed while the seal member 9 is opposed to the seal member 6. abut on.

In the compression step, a plurality of assembled fuel cells 1 are stacked, and a force is applied in a direction to bring the separators 2 on one side and the separators 3 on the other side close to each other with a predetermined clearance or load for compression. As a result, as shown in FIG. 1, the sealing members 6 and 9 are shrunk, and the gas diffusion layers 12 and 12 are also shrunk. After compression, the projecting portion 14 (electrolyte membrane 11 or film) is substantially parallel to the placement portion 5 of the one-side separator 2 without wrinkles.

Next, the effects of this embodiment will be described. In the fuel cell 1 and the fuel cell manufacturing method according to the present embodiment, as shown in FIG. is also set at a low position (a position spaced apart from the electrolyte membrane 11). In other words, the contact surface 6 a of the seal member 6 and the contact surface 17 b of the channel groove 17 provide a step for absorbing the thickness of the gas diffusion layer 12 of the membrane electrode assembly 4 . As a result, in the membrane electrode assembly placement step, when the membrane electrode assembly 4 is placed on the one-side separator 2, the bending of the projecting portion 14 can be eliminated or reduced. In other words, in the step of arranging the membrane electrode assembly, the projecting portion 14 can be arranged flat so as to be substantially parallel to the arrangement portion 5 of the one-side separator 2 .

As shown in FIGS. 10A and 11A, if the protrusions 112 and 212 are flexed during assembly, the protrusions 112 and 212 tend to wrinkle during compression. Since the deflection can be eliminated or reduced in the composite placement process, the wrinkles of the projecting portion 14 can be eliminated or reduced in the fuel cell 1 after the compression process.

Here, for example, like the convex bead 108 in FIG. 10A and the sealing member 204 in FIG. The displacement in the thickness direction of the electrolyte membrane increases, which causes wrinkles. In addition, with this form, it becomes difficult to design the dimensions of each part and to design the crushing allowance.

In this respect, according to the present embodiment, the sum of the crushing margin t1c of the seal member 6 of the one-side separator 2 and the crushing margin of the one-side separator 2 (substantially zero because there is no convex bead) in the sealing region 22 is 3 is set to be smaller than the sum of the crushing margin t10c of the seal member 9 and the crushing margin of the other separator 3 (substantially zero because there is no convex bead).

That is, in the compression process, by setting the compression margin t1c of the seal member 6 of the one-side separator 2 to be smaller than the compression margin t10c of the seal member 9 of the other-side separator 3, the seal area 22 expands during the compression process. It is possible to reduce the displacement of the portion 14 in the height direction (thickness direction of the electrolyte membrane 11). As a result, even during the compression process, wrinkles in the protruding portion 14 can be eliminated or reduced. Further, according to the present embodiment, it is possible to easily design the dimensions of each part and the crushing allowance.

The height and thickness of each member may be set as appropriate. However, if the conditions are set according to the above-described formula (1), the height position of the electrolyte membrane 11 on the side of the reaction region 21 after compression is , the height position of the protruding portion 14 (electrolyte membrane 11 or film) on the sealing region 22 side can be substantially the same. As a result, wrinkles in the protruding portion 14 can be eliminated or reduced.

Further, by using a lip gasket for the sealing member 9 of the separator 3 on the other side, it is possible to make the arrangement portion 8 flat and easily adjust the height position with respect to the reaction channel portion 10 side.

Further, by flattening the contact surface 6a of the seal member 6, it is possible to prevent the protrusion 14 from being flexed during assembly of each member, thereby preventing the protrusion 14 from being wrinkled. can be prevented. In addition, by placing the membrane electrode assembly 4 on the placement portion 5 of the separator 2 on one side, which is formed flat, the projecting portion 14 can be bent with a simple operation when assembling the members. It is possible to prevent the occurrence of wrinkles in the projecting portion 14 .

[Modification 1]
Next, Modification 1 of Embodiment 1 will be described. 4 is an exploded cross-sectional view of a main portion of a fuel cell according to Modification 1 of Embodiment 1. FIG. FIG. 5 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Modification 1 of Embodiment 1. FIG. As shown in FIG. 4, Modification 1 is different from Embodiment 1 in that receiving portions 31, 31 are formed on one side separator 2. As shown in FIG. Modification 1 will be described with a focus on portions that are different from Embodiment 1. FIG.

The receiving portions 31 are formed on both sides of the sealing member 6 in the placement portion 5 of the one-side separator 2 . The receiving portion 31 may be formed intermittently in the extending direction of the seal member 6, or may be formed continuously. Moreover, the receiving portion 31 may be formed only on one side of the sealing member 6 .

The shape of the receiving portion 31 is not particularly limited, but in this modified example, it is formed so as to decrease in diameter toward the tip. The height dimension of the receiving portion 31 is set to be larger than the thickness of the seal member 6 before assembly. Although the material of the receiving portion 31 is not particularly limited, for example, silicone rubber (VMQ), ethylene propylene diene rubber (EPDM), polyisobutylene (PIB), resin, or the like can be used.

As shown in FIG. 5 , in the membrane electrode assembly placement step according to Modification 1, the membrane electrode assembly 4 is placed on the one-side separator 2 . The body portion 13 of the membrane electrode assembly 4 is arranged on the contact surfaces 17b, 17b of the reaction channel portion 7, and the projecting portion 14 is arranged on the receiving portions 31, 31. As shown in FIG. At this time, the projecting portion 14 contacts the tips of the receiving portions 31 , 31 but is separated from the contact surface 6 a of the sealing member 6 . The spacing dimension may be set as appropriate, and is set to 0.1 mm, for example. For convenience of explanation, in FIG. 5, the gap from the contact surface 6a of the seal member 6 to the projecting portion 14 is drawn larger than it actually is.

In the compression process, a load acts in a direction in which the separator 2 on one side and the separator 3 on the other side approach each other. sandwiched. Therefore, it is preferable to set the material and shape of the receiving portion 31 so as not to affect the sealing mechanism.

Here, when the sealing member 6 has adhesiveness (tackiness), if the membrane electrode assembly placement step and the other side separator placement step are performed, the overhanging portion 14 and the sealing member 6 will stick to each other, resulting in poor workability. It may increase the time or cause warping, wrinkles, etc.

On the other hand, according to the modified example 1, since the arrangement portion 5 of the separator 2 on one side has the receiving portions 31, 31, the projecting portion 14 and the sealing member 6 are adhered to each other before performing the compression step. You can prevent sticking. As a result, even when the sealing member 6 has high tackiness, the projecting portion 14 is less likely to stick to the sealing member 6, facilitating assembly and shortening the working time. Furthermore, it is possible to prevent the projecting portion 14 from sticking to the seal member 6 in a bent state. Moreover, if the receiving portion 31 is made of a low-tack material, workability can be further improved.

[Modification 2]
FIG. 6 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Modification 2 of Embodiment 1. FIG. As shown in FIG. 6, the receiving portions 31, 31 may be provided on the projecting portion 14 (electrolyte membrane 11 or film).

The receiving portions 31 , 31 according to Modification 2 are formed on the surface of the protruding portion 14 facing the one-side separator 2 . The receiving portions 31 , 31 are formed so as to be arranged on both sides of the seal member 6 in the projecting portion 14 . The receiving portion 31 may be formed intermittently in the extending direction of the seal member 6, or may be formed continuously. Moreover, the receiving portion 31 may be formed so as to be arranged only on one side of the sealing member 6 .

In the membrane electrode assembly placement step, as shown in FIG. 6, the membrane electrode assembly 4 is placed on the one side separator 2 . The body portion 13 of the membrane electrode assembly 4 is arranged on the contact surfaces 17b, 17b of the reaction channel portion 7, and the tips of the receiving portions 31, 31 are brought into contact with the arrangement portion 5 of the separator 2 on one side. At this time, the projecting portion 14 and the seal member 6 are separated. The receiving portions 31 , 31 may be provided on the projecting portion 14 as in the second modification. Even with the configuration of Modification 2, the same effects as those of Modification 1 can be achieved.

[Example 2]
Next, a fuel cell and a method of manufacturing the fuel cell according to Example 2 will be described. FIG. 7 is a fragmentary cross-sectional view showing a fuel cell according to Example 2. FIG. As shown in FIG. 7, the fuel cell 1A according to Example 2 differs mainly in that the other side separator 3A is provided with a convex bead 41 and that a seal member 42 is used. In the second embodiment, the differences from the first embodiment will be mainly described.

As shown in FIG. 7, the one-side separator 2 and the membrane electrode assembly 4 are the same as those of the first embodiment. The other side separator 3A includes a convex bead 41, a sealing member 42, and a reaction channel portion 10. As shown in FIG. The convex bead 41 is a part that protrudes toward the separator 2 on one side. A flat arrangement portion 43 for arranging the seal member 42 is formed at the tip of the convex bead 41 .

The seal member 42 is provided in the placement portion 43 . A flat gasket having a rectangular cross section is used as the sealing member 42 in this embodiment.

FIG. 8 is an exploded cross-sectional view of a main part showing a fuel cell according to Example 2. FIG. As shown in FIG. 8, the dimensions and conditions of each member are substantially the same as in the first embodiment. Note that the height dimension of the convex bead 41 before assembly is t11, and the crushing margin of the convex bead 41 is t11c. Further, the thickness dimension of the sealing member 42 disposed on the other separator 3A before assembly is t12, and the compression margin of the sealing member 42 is t12c.

Next, a method for manufacturing a fuel cell according to Example 2 will be described. In Example 2, the preparation process, the membrane electrode assembly placement process, the other side separator placement process, and the compression process are performed. In the preparation step, the one side separator 2, the other side separator 3A and the membrane electrode assembly 4 are prepared.

FIG. 9 is a cross-sectional view of a main part showing a method of manufacturing a fuel cell according to Example 2. FIG. As shown in FIG. 9, in the membrane electrode assembly placement step, the membrane electrode assembly 4 is placed on the one side separator 2 in the same manner as in the first embodiment. In the other side separator placement step, the other side separator 3 A is placed on the membrane electrode assembly 4 . In the step of arranging the separator on the other side, the main body portion 13 of the membrane electrode assembly 4 is sandwiched between the reaction channel portions 7 and 10 to form the reaction region 21, and the projecting portion 14 is sandwiched between the sealing members 6 and 42. to form the seal area 22 .

In the compression step, as shown in FIG. 7, the separator 2 on one side and the separator 3A on the other side are compressed in a direction in which they approach each other. As a result, the seal members 6 and 42 are compressed, and the convex bead 41 and the gas diffusion layers 12 and 12 are also compressed. The projecting portion 14 is substantially parallel to the arrangement portion 5 of the separator 2 on one side.

As described above, the fuel cell and the method for manufacturing the fuel cell according to the second embodiment can also achieve substantially the same effect as the first embodiment. Further, by providing the convex bead 41 on the other side separator 3A and providing the sealing member 42 on the convex bead 41, the height position with respect to the reaction flow path section 10 side can be easily adjusted.

In addition, the sum of the crushing margin t1c of the seal member 6 of the separator 2 on the one side and the crushing margin of the separator 2 on the one side (substantially zero since there is no convex bead) in the sealing region 22 is calculated as the crushing margin of the convex bead 41 of the separator 3A on the other side. It is set smaller than the sum of t11c and the compression margin t12c of the seal member 42 (t1c<(t11c+t12c)).

That is, in the compression step, the crushing margin t1c of the seal member 6 of the separator 2 on the one side is set smaller than the sum of the crushing margin t11c of the convex bead 41 of the separator 3A on the other side and the crushing margin t12c of the seal member 42, whereby the compression Displacement in the height direction (thickness direction of the electrolyte membrane 11) of the overhanging portion 14 in the sealing region 22 during the process can be reduced. As a result, even during the compression process, wrinkles in the overhanging portion 14 can be eliminated or reduced. Further, according to the present embodiment, it is possible to easily design the dimensions of each part and the crushing allowance.

Although the embodiments of the present invention have been described above, design modifications can be made as appropriate without being limited to the configuration described above. For example, the receiving part 31 can also be provided in the form of the second embodiment.

REFERENCE SIGNS LIST 1 fuel cell 2 one side separator 3 other side separator 4 membrane electrode assembly 5 arrangement section 6 sealing member 7 reaction channel section 8 arrangement section 9 sealing member 10 reaction channel section 11 electrolyte membrane 12 gas diffusion layer 13 body section 14 Projecting portion 17b Contact surface 18b Contact surface 31 Receiving portion

Claims (4)

a one-side separator having a sealing member arranged in a flat arrangement portion and a reaction channel portion through which a reaction gas flows;
the other side separator having a seal member arranged in the placement portion and a reaction flow path portion through which the reaction gas flows;
a membrane electrode assembly disposed between the one-side separator and the other-side separator with the seal member interposed therebetween;
A reaction region is formed by sandwiching the main body of the membrane electrode assembly between the reaction channel portions, and an electrolyte membrane or film protruding from the main body is sandwiched between the sealing members. A seal area is formed,
A contact surface of the reaction channel portion of the one-side separator with which the main body portion of the membrane electrode assembly abuts is further away from the membrane electrode assembly than the arrangement surface of the arrangement portion of the one-side separator. is set on the side,
The sum of the compression margin of the seal member of the one-side separator and the compression margin of the one-side separator in the seal area is the sum of the compression margin of the seal member disposed on the other-side separator and the compression margin of the other-side separator. A fuel cell characterized by being smaller than. a one-side separator having a sealing member arranged in a flat arrangement portion and a reaction channel portion through which a reaction gas flows;
the other side separator having a seal member arranged in the placement portion and a reaction flow path portion through which the reaction gas flows;
a membrane electrode assembly disposed between the one-side separator and the other-side separator with the seal member interposed therebetween;
A reaction region is formed by sandwiching the main body of the membrane electrode assembly between the reaction channel portions, and an electrolyte membrane or film protruding from the main body is sandwiched between the sealing members. A seal area is formed,
A contact surface of the reaction channel portion of the one-side separator with which the main body portion of the membrane electrode assembly abuts is further away from the membrane electrode assembly than the arrangement surface of the arrangement portion of the one-side separator. is set on the side,
The sealing member provided on the one-side separator has a receiving portion on one or both sides in the width direction, and the height of the receiving portion before assembly is equal to that of the sealing member disposed on the one-side separator. A fuel cell, characterized in that it is larger than its thickness. a one-side separator having a sealing member arranged in a flat arrangement portion and a reaction channel portion through which a reaction gas flows;
the other side separator having a seal member arranged in the placement portion and a reaction flow path portion through which the reaction gas flows;
a membrane electrode assembly disposed between the one-side separator and the other-side separator with the seal member interposed therebetween;
A reaction region is formed by sandwiching the main body of the membrane electrode assembly between the reaction channel portions, and an electrolyte membrane or film protruding from the main body is sandwiched between the sealing members. A seal area is formed,
A contact surface of the reaction channel portion of the one-side separator with which the main body portion of the membrane electrode assembly abuts is further away from the membrane electrode assembly than the arrangement surface of the arrangement portion of the one-side separator. is set on the side,
a receiving portion formed on the electrolyte membrane or film projecting from the main body portion of the membrane electrode assembly,
The receiving portion is arranged on one side or both sides in the width direction of the seal member arranged on the one-side separator,
A fuel cell according to claim 1, wherein the height of the receiving portion before assembly is larger than the thickness of the seal member disposed on the one-side separator. A one-side separator having a seal member arranged in a flat arrangement portion and a reaction channel portion through which a reaction gas flows, and a seal member arranged in the arrangement portion and a reaction channel portion through which a reaction gas flows. a preparation step of preparing the other side separator and the membrane electrode assembly;
The membrane electrode assembly is arranged on the one-side separator, the main body portion of the membrane electrode assembly is arranged on the reaction channel portion of the one-side separator, and an electrolyte membrane protrudes from the main body portion. or a membrane electrode assembly placing step of placing a film on the sealing member of the one-side separator;
The other side separator is arranged on the membrane electrode assembly, the main body portion of the membrane electrode assembly is sandwiched between the reaction channel portions to form a reaction region, and the electrolyte membrane is sandwiched between the sealing members. Or a step of arranging a separator on the other side to sandwich the film to form a seal region;
a compression step of applying a force in a direction to bring the one side separator and the other side separator closer,
The contact surface of the reaction flow channel portion of the one-side separator with which the main body portion of the membrane electrode assembly abuts is spaced further from the membrane electrode assembly than the placement surface of the placement portion of the one-side separator. set to the side and
The sum of the compression margin of the seal member of the one-side separator and the compression margin of the one-side separator in the seal region is the sum of the compression margin of the seal member disposed on the other-side separator and the compression margin of the other-side separator. A method of manufacturing a fuel cell, characterized in that the setting is made smaller than.

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