Structure for bonding single cells of a fuel cell and method for bonding single cells of a fuel cell

Abstract

To provide an adhesion structure of a single cell of a fuel battery, capable of improving an adhesion property between a frame member and a separator, and an adhesion method of the single cell of the fuel battery.SOLUTION: An adhesion structure of a single cell of a fuel battery comprises: an MEA 10; a frame member 20; a pair of separators; and a plurality of manifold holes 60. The frame member 20 and each separator are adhered via an adhesive agent 50. In each separator, a plurality of groove channels in which a coolant flows, and a connection channel for connecting each groove channel and manifold holes 63 and 64 are provided. The adhesive agent 50 includes: an outer adhesion part 51 that is positioned at the side opposite to the MEA 10 against each manifold hole 60; and an inner side adhesive part 52 that is positioned between each manifold hole 60 and the MEA 10. The inner side adhesive part 52 includes: a main body part 53; and a reinforcement part 54. The reinforcement part 54 is provided at a position overlapping with the connection channel in a lamination direction of the frame member 20 and the separator.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present invention relates to an adhesive structure for a unit cell of a fuel cell and a method for adhesively bonding a unit cell of a fuel cell. [Background technology]

[0002] Patent Document 1 discloses a fuel cell stack formed by stacking a plurality of cells (hereinafter, unit cells). This unit cell has a membrane electrode & gas diffusion layer assembly (hereinafter, MEGA), a resin frame member (hereinafter, frame member), and a pair of separators. The frame member is provided around the periphery of the MEGA and forms the peripheral portion of the MEGA. The pair of separators sandwich the MEGA and the frame member.

[0003] The separator is formed with an inlet manifold and an outlet manifold for the reactant gas, groove-shaped flow paths through which the reactant gas flows, and communication passages that connect the manifolds to the flow paths.

[0004] The separator is also formed with an inlet manifold and an outlet manifold for the cooling water, groove-shaped flow paths through which the cooling water flows, and communication passages that connect the manifolds to the flow paths.

[0005] A first seal member is provided between the frame member and one of the separators. A second seal member is provided between the frame member and the other separator. The first seal member and the second seal member are interposed between the frame member and a portion of the separator surrounding the flow path.

[0006] A third seal member is provided between the separators of adjacent unit cells, and is interposed between the peripheral portion of the flow path of one separator and the peripheral portion of the flow path of the other separator.

[0007] In such a unit cell, an adhesive is conventionally used as the first and second sealing members, and a gasket is conventionally used as the third sealing member. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] JP 2013-89447 A Summary of the Invention [Problem to be solved by the invention]

[0009] In such a unit cell, each seal member is not provided at a position that overlaps with the communication passage of the separator adjacent to the seal member in the stacking direction. Therefore, the first seal member and the second seal member have a portion that does not overlap with the third seal member in the stacking direction. As a result, when a fuel cell stack is manufactured by stacking a plurality of unit cells, the load acting on the above portion is smaller than that acting on other portions. As a result, there is a risk of the adhesion between the frame member and the separator being reduced.

[0010] An object of the present invention is to provide an adhesion structure for a unit cell of a fuel cell and an adhesion method for a unit cell of a fuel cell that can improve adhesion between a frame member and a separator. [Means for solving the problem]

[0011] The adhesive structure for a unit cell of a fuel cell for achieving the above object is applied to a unit cell of a fuel cell including a power generation section, a frame member for holding the periphery of the power generation section, a pair of separators for sandwiching the power generation section and the frame member, and a plurality of manifold holes penetrating the frame member and the pair of separators on the outer periphery side of the power generation section and through which a reactant gas or a coolant flows, the adhesive structure for a unit cell of a fuel cell in which the frame member and the separators are adhered via an adhesive, and each of the separators has a surface opposite to a surface facing the power generation section, and a plurality of groove channels through which the coolant flows, and a plurality of groove channels and a manifold between the groove channels and the manifold. and a connecting flow path connecting the manifold hole and the manifold hole, the adhesive includes an outer adhesive portion located on the opposite side of the manifold hole from the power generation unit and extending along the edge of the manifold hole, and an inner adhesive portion located between the manifold hole and the power generation unit and extending along the edge of the manifold hole, the inner adhesive portion having a main body portion and a reinforcing portion provided adjacent to at least one of the power generation unit side and the manifold hole side of the main body portion, and the reinforcing portion is provided at a position overlapping with the connecting flow path in the stacking direction of the frame member and the separator.

[0012] According to this configuration, a reinforcing portion is provided in addition to the main body portion at a portion of the inner adhesive portion that overlaps with the connection flow path in the stacking direction. This increases the contact area between the inner adhesive portion and the frame member and the separator in the portion compared to when the portion is composed of only the main body portion. This makes it difficult for the main body portion to peel off from the frame member and the separator.

[0013] Meanwhile, as another means for increasing the contact area between the inner adhesive portion and the frame member and the separator, it is possible to consider increasing the width of the main body portion. However, when applying the adhesive to the frame member or the separator by screen printing, for example, increasing the width of the main body portion may cause air bubbles to easily get into the main body portion, which may actually decrease the adhesiveness. In this regard, according to the above-mentioned configuration, the contact area can be increased without increasing the width of the main body portion, so that the occurrence of air bubbles getting into the main body portion and the decrease in adhesiveness can be suppressed.

[0014] Therefore, the adhesion between the frame member and the separator can be improved. To achieve the above object, a method for bonding a single cell of a fuel cell includes a coating step of applying the adhesive to either the frame member or one of the pair of separators by screen printing.

[0015] According to this method, the adhesive including the inner adhesive portion and the outer adhesive portion is applied to the frame member or the pair of separators by screen printing, so that the inner adhesive portion can be easily applied to the frame member or the pair of separators. [Brief description of the drawings]

[0016] [Figure 1] FIG. 1 is a perspective view showing one embodiment of an adhesive structure for a unit cell of a fuel cell, with a frame member and a pair of separators separated from each other. [Diagram 2] FIG. 2 is a plan view showing the frame member of FIG. [Diagram 3] FIG. 3 is an enlarged plan view of the frame member of FIG. 2, focusing on the reinforcing portion of the inner adhesive portion. [Figure 4] FIG. 4 is a cross-sectional view taken along line 4-4 in FIG. [Diagram 5] FIG. 5 is a plan view showing a modified example of the reinforcing portion, which corresponds to FIG. [Figure 6] FIG. 6 is a plan view showing a modified example of the reinforcing portion, which corresponds to FIG. [Figure 7] FIG. 7 is a plan view showing a modified example of the reinforcing portion, which corresponds to FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0017] Hereinafter, an embodiment of a bonding structure for a single cell of a fuel cell and a bonding method for a single cell of a fuel cell will be described with reference to Figures 1 to 4. Note that in each drawing, for convenience of explanation, some of the components are shown exaggerated or simplified, so that the dimensional ratios of each component may differ from the actual ones. In addition, in the following description, "orthogonal" does not only mean a case where the components are strictly orthogonal, but also includes a case where the components are approximately orthogonal within a range in which the action and effect of each embodiment is achieved.

[0018] <Overall structure of a single fuel cell> As shown in FIG. 1, a single cell of a fuel cell has a membrane electrode assembly 10 (hereinafter, MEA 10), a frame member 20 that holds the periphery of the MEA 10, and a pair of separators 30, 40 that sandwich the MEA 10 and the frame member 20 therebetween.

[0019] 1 and 4, the single cell has an adhesive 50 that bonds the frame member 20 and the separators 30, 40, and a plurality of manifold holes 60 through which a reaction gas or a coolant flows. Note that the adhesive 50 that bonds the frame member 20 and the separator 30 is not shown in FIG.

[0020] The unit cell as a whole has a rectangular plate shape. In the following description, the stacking direction of the frame member 20 and the separators 30, 40 will be simply referred to as stacking direction X. Furthermore, among the directions perpendicular to the stacking direction X, the longitudinal direction of the unit cell will be simply referred to as longitudinal direction Y.

[0021] The manifold holes 60 have inlet side manifold holes 61, 65 for introducing the reaction gas into the single cell, and outlet side manifold holes 62, 66 for leading the reaction gas inside the single cell to the outside.

[0022] The inlet manifold hole 61 and the outlet manifold hole 62 are holes through which a fuel gas flows. The inlet manifold hole 65 and the outlet manifold hole 66 are holes through which an oxidizer gas flows. The fuel gas is, for example, hydrogen gas. The oxidizer gas is, for example, air.

[0023] The manifold hole 60 has an inlet side manifold hole 63 for introducing a refrigerant into the unit cell, and an outlet side manifold hole 64 for discharging the refrigerant in the unit cell to the outside. The refrigerant is, for example, cooling water.

[0024] The inlet side manifold holes 61, 63, 65 and the outlet side manifold holes 62, 64, 66 are rectangular in plan view and penetrate the unit cells in the stacking direction X. The inlet side manifold hole 61 and the outlet side manifold holes 64, 66 are provided on one side of the unit cell in the longitudinal direction Y (the left side in the left-right direction in FIG. 1 ). The inlet side manifold hole 61 and the outlet side manifold holes 64, 66 are arranged at intervals from each other in directions perpendicular to both the stacking direction X and the longitudinal direction Y.

[0025] In the following description, the direction in which the inlet side manifold hole 61 and the outlet side manifold holes 64, 66 are arranged will be simply referred to as the arrangement direction Z. The outlet side manifold hole 62 and the inlet side manifold holes 63, 65 are provided on the other side (the right side in FIG. 1) of the unit cell in the longitudinal direction Y. The outlet side manifold hole 62 and the inlet side manifold holes 63, 65 are arranged at intervals from each other in the arrangement direction Z.

[0026] Each component of the unit cell will now be described in detail. <mea10> As shown in Fig. 1, the MEA 10 has a solid polymer electrolyte membrane (hereinafter, electrolyte membrane) (not shown) and electrodes 11A, 11B provided on both sides of the electrolyte membrane. In this embodiment, the electrode bonded to one side (upper side in the vertical direction in Fig. 1) of the electrolyte membrane (not shown) in the stacking direction X is the cathode electrode 11A. The electrode bonded to the other side (lower side in Fig. 1) of the electrolyte membrane in the stacking direction X is the anode electrode 11B.

[0027] The MEA 10 corresponds to the power generating section of the fuel cell according to the present invention. <Frame member 20> 1 and 2, the frame member 20 has a rectangular frame shape and has an opening 27 in the center. The MEA 10 is joined to the edge of the opening 27 from one side in the stacking direction X (the upper side in FIG. 1).

[0028] The frame member 20 also has through holes 21, 23, 25 that constitute the inlet side manifold holes 61, 63, 65, and through holes 22, 24, 26 that constitute the outlet side manifold holes 62, 64, 66. The through holes 21, 22, 23, 24, 25, 26 penetrate the frame member 20 in the stacking direction X on the outer circumferential side of the MEA 10.

[0029] The frame member 20 is made of, for example, a hard resin material. <Separator 30> As shown in FIG. 1, separator 30 faces anode electrode 11B of MEA 10, and has a first surface 30A facing MEA 10 and frame member 20, and a second surface 30B opposite to first surface 30A.

[0030] The separator 30 has through holes 31, 33, 35 that constitute the inlet side manifold holes 61, 63, 65, and through holes 32, 34, 36 that constitute the outlet side manifold holes 62, 64, 66. The through holes 31, 32, 33, 34, 35, 36 penetrate the separator 30 in the stacking direction X on the outer circumferential side of the opposing surface 30a of the first surface 30A that faces the anode electrode 11B of the MEA 10.

[0031] The first surface 30A has a plurality of groove channels 37A through which the fuel gas flows, and connection channels 37B that connect the groove channels 37A to the through holes 31, 32. The groove flow passage 37A is configured by an uneven shape formed on the opposing surface 30a.

[0032] The connection flow path 37B is configured by an uneven shape formed on the facing surface 30b facing the frame member 20 of the first surface 30A. The connection flow passages 37B extend from both ends of the groove flow passage 37A in the extending direction toward the through holes 31 and 32, respectively.

[0033] Through hole 31 and through hole 32 are communicated with each other by groove flow path 37A and connection flow path 37B. The second surface 30B has a plurality of groove channels 38A through which the coolant flows, and connection channels 38B that connect the groove channels 38A to the through holes 33, .

[0034] The groove 38A is formed of an uneven shape formed on the second surface 30B opposite to the opposing surface 30a. The uneven shape constituting the groove 38A is inseparably linked to the uneven shape of the groove 37A.

[0035] The connection flow path 38B is configured by an uneven shape formed on the second surface 30B on the side opposite to the opposing surface 30b. The connection flow passages 38B extend from both ends of the groove flow passage 38A in the extending direction toward the through holes 33 and 34, respectively.

[0036] Through hole 33 and through hole are communicated with each other by groove flow path 38A and connection flow path 38B. In FIG. 1, the outer edge of the portion of the separator 30 where the plurality of groove flow paths 37A, 38A are formed and the outer edge of the portion where the connection flow paths 37B, 38B are formed are shown in a simplified manner.

[0037] <Separator 40> As shown in FIG. 1, separator 40 faces cathode electrode 11A of MEA 10, and has a second surface 40B facing MEA 10 and frame member 20, and a first surface 40A opposite to second surface 40B.

[0038] The separator 40 has through holes 41, 43, 45 that constitute the inlet side manifold holes 61, 63, 65, and through holes 42, 44, 46 that constitute the outlet side manifold holes 62, 64, 66. The through holes 41, 42, 43, 44, 45, 46 penetrate the separator 40 in the stacking direction X on the outer circumferential side of the opposing surface 40a of the second surface 40B that faces the cathode electrode 11A of the MEA 10.

[0039] The first surface 40A has a plurality of groove channels 47A through which the coolant flows, and connection channels 47B that connect the groove channels 47A to the through holes 43, . The groove flow passage 47A is formed in an uneven shape on the surface opposite to the opposing surface 40a.

[0040] The connection flow path 47B is configured by an uneven shape formed on the surface of the second surface 40B opposite to the facing surface 40b that faces the frame member 20. The connection flow passages 47B extend from both ends of the groove flow passage 47A in the extending direction toward the through holes 43 and 44, respectively.

[0041] The through hole 43 and the through hole 44 are communicated with each other by the groove flow passage 47A and the connection flow passage 47B. The second surface 40B has a plurality of groove channels 48A through which the oxidant gas flows, and connection channels 48B that connect the groove channels 48A to the through holes 45, 46.

[0042] The groove 48A is configured by a concave-convex shape formed on the opposing surface 40a. The concave-convex shape constituting the groove 48A is in an inseparable relationship with the concave-convex shape of the groove 47A. The connection flow path 48B is configured by an uneven shape formed on the opposing surface 40b.

[0043] The connection flow passages 48B extend from both ends of the groove flow passage 48A in the extending direction toward the through holes 45 and 46, respectively. Through hole 45 and through hole 46 are communicated with each other by groove flow path 48A and connection flow path 48B.

[0044] In FIG. 1, the outer edge of the portion of the separator 40 where the plurality of groove flow paths 47A, 48A are formed and the outer edge of the portion where the connection flow paths 47B, 48B are formed are shown in a simplified manner.

[0045] On the first surface 40A, between the unit cells stacked in the stacking direction X, a gasket 70 is provided that seals between the separator 30 of one unit cell and the separator 40 of the other unit cell.

[0046] The gasket 70 extends along the edge of the separator 40 and also extends along the edges of the through holes 41, 42, 45, and 46. More specifically, the gasket 70 is provided around the entire edge of the separator 40. The gasket 70 is also provided around the entire edges of the through holes 41, 42, 45, and 46.

[0047] The gasket 70 is not provided between the through hole 43 and the groove flow passage 47A, and between the through hole 44 and the groove flow passage 47A. That is, the gasket 70 is provided so as not to overlap with the connection flow passage 47B in the stacking direction X.

[0048] <Adhesive 50> 1 and 4, the adhesive 50 is provided on each of the first surface 20A of the frame member 20, which faces the separator 40, and the second surface 20B opposite the first surface 20A. In this embodiment, the adhesive 50 on the second surface 20B is the same as the adhesive 50 on the first surface 20A, which is reversed left and right in the left and right direction (longitudinal direction Y) of FIG. 1. Therefore, hereinafter, only the adhesive 50 on the first surface 20A will be described, and a detailed description of the adhesive 50 on the second surface 20B will be omitted.

[0049] The adhesive 50 extends along the edge of the frame member 20 and also extends along the edges of the through holes 21, 22, 23, and 24. More specifically, the adhesive 50 is provided around the entire periphery of the edge of the frame member 20. In addition, the adhesive 50 is provided around the entire periphery of the edges of the through holes 21, 22, 23, and 24.

[0050] In the following, the portions of the adhesive 50 located on the opposite side of the MEA 10 from the through holes 21, 24, 26 and the portions located on the opposite side of the MEA 10 from the through holes 22, 23, 25 will be described as outer adhesive portions 51. The portions of the adhesive 50 located between the through holes 21, 24, 26 and the MEA 10 and the portions located between the through holes 22, 23, 25 and the MEA 10 will be described as inner adhesive portions 52.

[0051] 2, the adhesive 50 has a pair of outer adhesive portions 51. One of the outer adhesive portions 51 extends along the edge on one side in the longitudinal direction Y (the left side in the left-right direction in FIG. 2) of the through holes 21, 24, 26. The other outer adhesive portion 51 extends along the edge on the other side in the longitudinal direction Y of the through holes 22, 23, 25 (the right side in FIG. 2).

[0052] As shown in FIG. 4, the outer adhesive portion 51 is provided at a position where it overlaps with the gasket 70 in the stacking direction X. 2, the width W1 of the outer adhesive portion 51 is constant throughout the extension direction of the outer adhesive portion 51. The width W1 of the outer adhesive portion 51 is the length of the outer adhesive portion 51 in a direction perpendicular to the extension direction of the outer adhesive portion 51.

[0053] The adhesive 50 has a pair of inner adhesive portions 52 . Each of the inner adhesive portions 52 has a main body portion 53 and a reinforcing portion 54 . One of the main body portions 53 extends along the edge on the other side in the longitudinal direction Y (the right side in FIG. 2) of the through holes 21, 24. The other main body portion 53 extends along the edge on one side in the longitudinal direction Y of the through holes 22, 23 (the left side in FIG. 2).

[0054] The width W2 of the main body portion 53 is constant throughout the extension direction of the main body portion 53. The width W2 of the main body portion 53 is the length of the main body portion 53 in a direction perpendicular to the extension direction of the main body portion 53. The width W2 of the main body portion 53 is the same as the width W1 of the outer adhesive portion 51 (W1=W2).

[0055] 2, the reinforcing portion 54 is provided adjacent to the main body portion 53 on the MEA 10 side. Note that only the outline of the reinforcing portion 54 is shown in FIG. Here, a region of the first surface 20A of the frame member 20 that overlaps with the connection flow passage 47B of the separator 40 in the stacking direction X is referred to as a region A. In addition, in Fig. 2, the region A is indicated by a two-dot chain line.

[0056] The reinforcing portion 54 is arranged at an interval from the portion of the main body portion 53 that overlaps with the region A in the longitudinal direction Y. The reinforcing portion 54 is provided at a position that overlaps with the region A over the entire extension direction. In this embodiment, both ends of the reinforcing portion 54 in the extension direction are connected to the main body portion 53.

[0057] As shown in FIG. 3, the reinforcing portion 54 has a plurality of first straight line portions 54a extending in a direction intersecting the extending direction of the reinforcing portion 54, and a plurality of second straight line portions 54b intersecting with each of the first straight line portions 54a.

[0058] The multiple first straight portions 54a are arranged at intervals from one another in the extension direction of the reinforcing portion 54. The width W3 of the first straight portion 54a is constant throughout the extension direction of the first straight portion 54a. The width W3 of the first straight portion 54a is the length of the first straight portion 54a in a direction perpendicular to the extension direction of the first straight portion 54a. The width W3 of the first straight portion 54a is smaller than the width W2 of the main body portion 53 (W3 <W2)。

[0059] The multiple second straight line portions 54b are arranged at intervals from each other in the extension direction of the reinforcing portion 54. The second straight line portion 54b connects a pair of first straight line portions 54a adjacent to the first straight line portion 54a that the second straight line portion 54b intersects with.

[0060] The width W4 of the second straight portion 54b is constant throughout the extension direction of the second straight portion 54b. The width W4 of the second straight portion 54b is the length of the second straight portion 54b in a direction perpendicular to the extension direction of the second straight portion 54b. The width W4 of the second straight portion 54b is the same as the width W3 of the first straight portion 54a (W4=W3). In this embodiment, the width W3 of the first straight portion 54a and the width W4 of the second straight portion 54b each correspond to the width of the reinforcing portion according to the present invention.

[0061] The adhesive 50 is applied onto the frame member 20, for example, by the following application process. First, a screen (not shown) with holes in the areas corresponding to the adhesive 50, including the outer adhesive portion 51 and the inner adhesive portion 52, is prepared and placed on the first surface 20A of the frame member 20. Next, adhesive is placed on the screen, and the adhesive is pressed onto the first surface 20A of the frame member 20 by a squeegee (not shown). When the screen pressed by the squeegee is separated from the first surface 20A of the frame member 20, the adhesive 50 is transferred onto the first surface 20A.

[0062] Next, the operation of this embodiment will be described. 4, the outer adhesive portion 51 is provided at a position overlapping the gasket 70 in the stacking direction X. Therefore, when a plurality of unit cells are stacked to manufacture a fuel cell stack, a load acts on the outer adhesive portion 51 via the gasket 70. This makes it difficult for the outer adhesive portion 51 to peel off from the frame member 20 and the separator 40. Similarly, the outer adhesive portion 51 is also difficult to peel off from the frame member 20 and the separator 30.

[0063] On the other hand, according to the configuration of this embodiment, the reinforcing portion 54 is provided separately from the main body portion 53 in the portion of the inner adhesive portion 52 that overlaps with the connection flow path 47B in the stacking direction X, i.e., in the portion that does not overlap with the gasket 70 in the stacking direction X. This increases the contact area between the inner adhesive portion 52 and the frame member 20 and the separator 40 in the above-mentioned portion compared to when the above-mentioned portion is composed of only the main body portion 53. Therefore, when a fuel cell stack is manufactured by stacking a plurality of unit cells, even if the load acting on the above-mentioned portion is smaller than that of other portions, the main body portion 53 is less likely to peel off from the frame member 20 and the separator 40. Similarly, the main body portion 53 is less likely to peel off from the frame member 20 and the separator 30.

[0064] Next, the effects of this embodiment will be described. (1) The adhesive 50 has an outer adhesive portion 51 located on the opposite side of the manifold hole 60 from the MEA 10 and extending along the edge of the manifold hole 60, and an inner adhesive portion 52 located between the manifold hole 60 and the MEA 10 and extending along the edge of the manifold hole 60. The inner adhesive portion 52 has a main body portion 53 and a reinforcing portion 54 provided adjacent to the MEA 10 side of the main body portion 53. The reinforcing portion 54 is provided at a position overlapping with the connection flow path 47B in the stacking direction X.

[0065] This configuration provides the above-mentioned effects. Meanwhile, another method for increasing the contact area between the inner adhesive portion 52 and the frame member 20 and the separators 30, 40 is to increase the width W2 of the main body portion 53. However, when the adhesive 50 is applied to the frame member 20 by screen printing, increasing the width W2 of the main body portion 53 may cause air bubbles to easily get into the main body portion 53, which may actually decrease the adhesiveness. In this regard, according to the above configuration, the contact area can be increased without increasing the width W2 of the main body portion 53, so that the inclusion of air bubbles and thus the decrease in adhesiveness can be suppressed.

[0066] Therefore, the adhesion between the frame member 20 and the separators 30, 40 can be improved. (2) The width W1 of the outer adhesive portion 51 is constant in the extension direction of the outer adhesive portion 51. The width W2 of the main body portion 53 is constant in the extension direction of the main body portion 53 and is the same as the width W1 of the outer adhesive portion 51. The width W3 of the first straight portion 54a and the width W4 of the second straight portion 54b of the reinforcing portion 54 are both smaller than the width W2 of the main body portion 53.

[0067] According to this configuration, the width W2 of the main body portion 53 is the same as the width W1 of the outer adhesive portion 51, and the width W3 of the first straight portion 54a and the width W4 of the second straight portion 54b of the reinforcing portion 54 are smaller than the width W2 of the main body portion 53. Therefore, when the adhesive 50 is applied, it is possible to further prevent air bubbles from being mixed into the inner adhesive portion 52.

[0068] Therefore, the adhesion between the frame member 20 and the separators 30, 40 can be further improved. (3) The method for bonding the unit cells includes a coating step of coating the adhesive 50 onto the frame member 20 by screen printing.

[0069] According to this method, the adhesive 50 including the inner adhesive portion 52 and the outer adhesive portion 51 is applied to the first surface 20A and the second surface 20B of the frame member 20 by screen printing. Therefore, the inner adhesive portion 52 can be easily applied to the frame member 20.

[0070] <Example of change> This embodiment can be modified as follows: This embodiment and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0071] The shape of the manifold hole 60 is not limited to the rectangular shape exemplified in this embodiment. For example, it may be a quadrilateral shape including a square with rounded corners or a rectangle with rounded corners, or a circular shape including an egg shape or an ellipse shape.

[0072] The flows of the reactant gas and the coolant in the manifold holes 60 are not limited to those exemplified in this embodiment, and for example, the outlet side manifold holes 66 may be inlet side manifold holes for the oxidant gas, and the inlet side manifold holes 65 may be outlet side manifold holes for the oxidant gas. In addition, the outlet side manifold holes 64 may be inlet side manifold holes for the coolant, and the inlet side manifold holes 63 may be outlet side manifold holes for the coolant. In other words, the oxidant gas flowing through the groove channels 48A and the coolant flowing through the groove channels 38A and 47A may flow in the same direction as the fuel gas flowing through the groove channels 37A.

[0073] The arrangement of the manifold holes 60 is not limited to that exemplified in this embodiment. For example, the inlet side manifold holes and the outlet side manifold holes through which any one of the fuel gas, the oxidant gas, and the coolant flows may be arranged in the arrangement direction Z with the MEA 10 in between.

[0074] The adhesive 50 is not limited to the one exemplified in this embodiment in which the width W3 of the first straight portion 54a and the width W4 of the second straight portion 54b of the reinforcing portion 54 are smaller than the width W2 of the main body portion 53. In other words, the width W3 and the width W4 may be the same as the width W2 (W2=W3, W2=W4).

[0075] The adhesive 50 is not limited to the one in which the width W2 of the main body portion 53 is the same as the width W1 of the outer adhesive portion 51 as in the embodiment. In other words, the width W2 may be smaller than the width W1 (W2 <W1)。

[0076] The reinforcing portion 54 is not limited to having a plurality of first straight portions 54a and a plurality of second straight portions 54b as exemplified in this embodiment. For example, as shown in FIG. 5, a plurality of third straight portions 54c extending in the extension direction of the reinforcing portion 54 may be arranged at intervals in the same extension direction. In this case, the width W5 of the third straight portion 54c may be equal to or smaller than the width W2 of the main body portion 53. The width W5 of the third straight portion 54c is the length of the third straight portion 54c in a direction perpendicular to the extension direction of the third straight portion 54c. In this modification, the width W5 of the third straight portion 54c corresponds to the width of the reinforcing portion according to the present invention.

[0077] The reinforcing portion 54 is not limited to being composed of a plurality of straight line portions. For example, as shown in FIG. 6, the reinforcing portion 54 may be composed of a plurality of points 54d. In this case, the width W6 of the point 54d may be equal to or smaller than the width W2 of the main body portion 53. As shown in FIG. 6, when the point 54d is circular, the width W6 of the point 54d is the diameter of the point 54d. When the point 54d is polygonal, the width W6 of the point 54d is the length of the longest diagonal line. In this modification, the width W6 of the point 54d corresponds to the width of the reinforcing portion according to the present invention.

[0078] The reinforcing portion 54 is not limited to being composed of multiple straight line portions or multiple points. As shown in Fig. 7, the reinforcing portion 54 may be composed of one straight line. In this case, the width W7 of the reinforcing portion 54 only needs to be equal to or smaller than the width W2 of the main body portion 53. The width W7 of the reinforcing portion 54 is the length of the straight line in a direction perpendicular to the extension direction of the straight line.

[0079] The reinforcing portion 54 does not have to be connected to the main body portion 53 as illustrated in this embodiment. The reinforcing portion 54 is not limited to being provided on the MEA 10 side of the main body portion 53 as exemplified in this embodiment. For example, the reinforcing portion 54 may be provided between the main body portion 53 and the through holes 23, 24.

[0080] In the present embodiment, the adhesive 50 is applied to the frame member 20, but the adhesive 50 may be applied to each of the first surface 30A of the separator 30 and the second surface 40B of the separator 40. [Explanation of symbols]

[0081] A…Area W1, W2, W3, W4, W5, W6, W7…Width X: Stacking direction Y: Longitudinal direction Z: Lineup direction 10...Membrane electrode assembly, MEA 11A…Cathode electrode 11B…Anode electrode 20...Frame member 20A…1st page 20B…Second side 21...Through hole 22...Through hole 23...Through hole 24...Through hole 25...Through hole 26...Through hole 27…Opening 30…Separator 30A…First side 30a...Opposing surface 30b...Opposing surface 30B…Second side 31...Through hole 32...Through hole 33...Through hole 34...Through hole 35...Through hole 36...Through hole 37A…Groove channel 37B…connecting channel 38A…Groove channel 38B…connecting channel 40…Separator 40A…Page 1 40B…Second side 40a…Facing surface 40b...Opposing surface 41...Through hole 42...Through hole 43...Through hole 44…Through hole 45...Through hole 46…Through hole 47A…Groove channel 47B…connecting channel 48A…Groove channel 48B…connecting channel 50…Glue 51...Outer adhesive part 52…Inner adhesive part 53…Main body 54…Reinforcement 54a...first straight section 54b…Second straight section 54c...Third straight section 54d…point 60…Manifold hole 61...Inlet manifold hole 62...Outlet manifold hole 63...Inlet manifold hole 64...Outlet manifold hole 65...Inlet manifold hole 66...Outlet manifold hole 70…Gasket

Claims

1. The present invention relates to an adhesive structure for a single cell of a fuel cell, the adhesive structure being applied to a single cell of a fuel cell including a power generation section, a frame member that holds a periphery of the power generation section, a pair of separators that sandwich the power generation section and the frame member, and a plurality of manifold holes that penetrate the frame member and the pair of separators on an outer periphery side of the power generation section and through which a reactant gas or a coolant flows, the frame member and the separators being bonded together via an adhesive, the adhesive structure comprising: each of the separators is provided on a surface opposite to a surface facing the power generation unit with a plurality of groove channels through which the refrigerant flows, and a connection channel connecting the groove channels and the manifold hole; The adhesive is an outer adhesive portion located on the opposite side of the manifold hole from the power generation portion and extending along an edge of the manifold hole; an inner adhesive portion located between the manifold hole and the power generation portion and extending along an edge of the manifold hole, the inner adhesive portion has a main body portion and a reinforcing portion provided adjacent to at least one of a power generation unit side and a manifold hole side of the main body portion, the reinforcing portion is provided at a position overlapping with the connection flow path in a stacking direction of the frame member and the separator. Bonding structure of a single fuel cell.

2. The width of the outer adhesive portion is constant in an extension direction of the outer adhesive portion, a width of the main body portion is constant in an extension direction of the main body portion and is equal to or smaller than a width of the outer adhesive portion; The width of the reinforcing portion is equal to or smaller than the width of the main body portion. The bonded structure for a single fuel cell according to claim 1 .

3. 3. A method for bonding unit cells of a fuel cell according to claim 1 or 2, comprising the steps of: a coating step of coating the adhesive on either the frame member or the pair of separators by screen printing, A method for bonding single fuel cell cells.

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