JP2008084707A - Fuel cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell and its manufacturing method capable of suppressing overflow of an adhesive and capable of improving adhesive strength between resin frames and separators arranged and installed on both sides of an electrolyte-electrode assembly. <P>SOLUTION: The fuel cell 1 is provided with the electrolyte-electrode assembly having an anode electrode 14 arranged on one face of an electrolyte and a cathode electrode 17 arranged on the other face, a separator resin frame assembly formed by joining the separator 23 and the resin frame 21 by an adhesive 70, and the separator resin frame assembly formed by the separator 24 and the resin frame 22 by the adhesive 70, formed by laminating the separator resin frame assemblies on the both sides of the electrolyte-electrode assembly by making the resin frames 21 and 22 opposed to the electrolyte-electrode assembly, and obtained by forming through-holes 60 through which the adhesive 70 penetrates in a region where adhesion of the resin frames 21 and 22 to the separators 23 and 24 is possible. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell and a manufacturing method thereof, and more particularly to a fuel cell in which a resin frame and a separator are joined with an adhesive and a manufacturing method thereof.

  Conventionally, as a general fuel cell, for example, a membrane-electrode assembly having an electrolyte membrane, an anode electrode disposed on one surface of the electrolyte membrane, and a cathode electrode disposed on the other surface ( Some have a structure in which separators are disposed on both sides of an MEA (Membrane Electrode Assembly, hereinafter simply referred to as “MEA”) via a resin frame. In such a fuel cell, the resin frames arranged between the MEAs, and the resin frame and the separator are usually bonded by an adhesive, and air or adhesive is usually attached to the outer peripheral end of the resin frame. Holes and grooves for releasing the agent are formed.

  In the fuel cell having such a configuration, the adhesive may protrude to the outside through holes or grooves for allowing air or adhesive to escape, and there is a possibility that an adhesive burr may be formed at the outer peripheral edge of the resin frame. It was. In order to prevent the adhesive from sticking out, it is conceivable to appropriately control the amount of adhesive used. However, if the amount of adhesive applied is reduced, the adhesive strength decreases, so the adhesive strength is maintained. In fact, it is difficult to apply the adhesive with an optimal application amount that suppresses the protrusion of the adhesive.

  In view of this, for example, a structure in which a weir is formed in the seal portion of the resin frame to prevent the sealing adhesive from protruding is introduced. (For example, refer to Patent Document 1). In addition, an adhesive reservoir groove formed on the seal surface of the separator is also introduced. (For example, refer to Patent Document 2).

Further, a membrane electrode assembly in which catalyst layers are respectively disposed on both surfaces of the electrolyte membrane, first and second gas diffusion layers disposed on both surfaces of the membrane electrode complex, and the first and second gas diffusion layers And a gasket for sealing the reaction gas, the gasket being disposed on the surface of the gas diffusion layer so as to face the separator, and at least the first gas. A fuel cell is also introduced which is integrated through a through-hole that penetrates the first and second gas diffusion layers in common. (For example, refer to Patent Document 3).
JP 2003-77499 A Japanese Patent Laid-Open No. 2002-367631 W2002 / 89240 Publication JP 2006-19204 A JP 2005-216802 A

  However, in the fuel cell according to Patent Document 1 described above, an adhesive layer is disposed between a resin frame and a separator adjacent to the resin frame, and the adhesive layer adheres the resin frame to the separator. Therefore, it is difficult to further improve the adhesive force between the adhesive layer and the resin frame and between the adhesive layer and the separator with the adhesive currently used. .

  In addition, the fuel cells according to Patent Documents 2 and 3 are not provided with a resin frame, and therefore no mention is made of a method for fixing the resin frames. Furthermore, the fuel cell according to Patent Document 3 does not mention a fixing method between the separator and UEA (Unitized Electrode Assembly).

  The present invention has been made in view of such circumstances, and can prevent the adhesive from protruding and improve the adhesive strength between the resin frame and the separator disposed on both sides of the electrolyte-electrode assembly. It is an object of the present invention to provide a fuel cell and a method for manufacturing the same.

  In order to achieve this object, the present invention provides an electrolyte-electrode assembly in which an anode electrode is disposed on one surface of an electrolyte and a cathode electrode is disposed on the other surface, and a separator and a resin frame are bonded with an adhesive. The separator-resin frame assembly is laminated, and the separator-resin frame assembly is laminated on both sides of the electrolyte-electrode assembly with the resin frame surface facing the electrolyte-electrode assembly. A fuel cell is provided, wherein a through-hole through which the adhesive penetrates is formed in a region where the resin frame can be bonded to the separator.

  In the fuel cell having this configuration, since a through-hole through which an adhesive for bonding the resin frame and the separator passes is formed in an area where the resin frame can be bonded to the separator, the resin frame The adhesive interposed between the separator and the adhesive and the adhesive penetrating the through hole are integrated and cooperate with each other to bond the resin frame and the separator. Therefore, the adhesive strength between the resin frame and the separator can be improved. Moreover, since the said adhesive agent penetrates the said through-hole, it can suppress that an adhesive agent protrudes from the outer peripheral end (end surface) of a resin frame. In addition, since the through hole also serves to release the adhesive and air, it is not necessary to separately form holes and grooves for releasing the adhesive and air in the resin frame, which complicates the resin frame structure. It can also be suppressed.

  In the fuel cell according to the present invention, the through hole may have a structure that penetrates in the stacking direction of the electrolyte-electrode assembly and the separator-resin frame assembly.

  Moreover, in the fuel cell according to the present invention, the adhesive includes a through-hole formed in a resin frame laminated on one surface of the electrolyte-electrode assembly, and the other surface of the electrolyte-electrode assembly. It can also be set as the structure which penetrates both of the through-holes formed in the resin frame laminated | stacked on. With this configuration, in addition to the advantages described above, the adhesive applied between the resin frame and the separator and the adhesive applied between the resin frames are integrated and cooperate with each other through the through hole. In addition, the adhesive strength between the resin frame and the separator can be improved, as well as the adhesive strength between the resin frames laminated with the electrolyte-electrode assembly interposed therebetween. That is, since the electrolyte-electrode assembly and the separator-resin frame assembly laminated on both sides of the electrolyte-electrode assembly are integrated by the adhesive penetrating the through-hole, these are further strengthened. Can be glued to.

  The present invention also provides a separator-resin formed by joining an electrolyte-electrode assembly in which an anode electrode is disposed on one surface of an electrolyte and a cathode electrode is disposed on the other surface, and a separator and a resin frame. And a fuel cell manufacturing method comprising: laminating the separator-resin frame assembly on both sides of the electrolyte-electrode assembly with the resin frame surface facing the electrolyte-electrode assembly. A step of forming a through-hole through which an adhesive passes in a region of the resin frame that can be bonded to the separator, and bonding the separator and the resin frame with an adhesive penetrating the through-hole. A step of forming a separator-resin frame assembly, and laminating the separator-resin frame assembly on both sides of the electrolyte-electrode assembly, and the electrolyte-electrode assembly. And a step of adhering a resin frame laminated on one surface of the resin frame and a resin frame laminated on the other surface of the electrolyte-electrode assembly with an adhesive penetrating the through hole. The manufacturing method of this is provided.

  According to this method of manufacturing a fuel cell, the resin frame and the separator are bonded by the adhesive that passes through the through-hole formed in the resin frame, so that the adhesive strength is improved. Moreover, since the said adhesive agent penetrates the said through-hole, it can suppress that an adhesive agent protrudes from the outer peripheral surface (end surface) of a resin frame. In addition, since the through hole also serves to release the adhesive and air, it is not necessary to separately form holes and grooves for releasing the adhesive and air in the resin frame, which complicates the resin frame structure. It can also be suppressed.

  The fuel cell manufacturing method according to the present invention includes a through hole formed in a resin frame laminated on one surface of the electrolyte-electrode assembly, and a laminate on the other surface of the electrolyte-electrode assembly. A step of allowing the adhesive to penetrate both through holes formed in the resin frame may be further provided. By further comprising this step, the electrolyte-electrode assembly and the separator-resin frame assembly laminated on both sides of the electrolyte-electrode assembly are bonded by an adhesive that penetrates both through holes. Therefore, the adhesive strength between the resin frame and the separator can be improved, as well as the adhesive strength between the resin frames laminated with the electrolyte-electrode assembly interposed therebetween. Can be bonded more firmly.

  The fuel cell according to the present invention has a structure in which the resin frame and the separator are bonded to each other with an adhesive penetrating the through hole, so that the adhesive strength between the resin frame and the separator can be improved. . Moreover, since the said adhesive agent penetrates the said through-hole, it can suppress that an adhesive agent protrudes from the outer peripheral surface of a resin frame. As a result, a highly reliable fuel cell can be provided. In addition, the through-hole also plays a role of releasing adhesive and air, so there is no need to separately form holes and grooves for releasing adhesive and air in the resin frame, making the resin frame structure simpler than before can do.

  According to the method of manufacturing a fuel cell according to the present invention, the resin frame and the separator can be bonded by the adhesive that penetrates the through hole formed in the resin frame, so that the adhesive strength is improved. Moreover, since the said adhesive agent penetrates the said through-hole, it can suppress that an adhesive agent protrudes from the outer peripheral surface of a resin frame. As a result, a highly reliable fuel cell can be manufactured. In addition, the through hole also plays a role of releasing adhesive and air, so there is no need to separately form holes and grooves for releasing adhesive and air in the resin frame, making the resin frame structure simpler than before The manufactured fuel cell can also be manufactured.

  Next, a fuel cell and a method for manufacturing the same according to a preferred embodiment of the present invention will be described with reference to the drawings. In addition, embodiment described below is the illustration for demonstrating this invention, and this invention is not limited only to these embodiment. Therefore, the present invention can be implemented in various forms without departing from the gist thereof.

  FIG. 1 is an overall schematic diagram of the fuel cell according to the present embodiment in a posture in which the cell stacking direction is the vertical direction, and FIG. 2 is an enlarged view of a part of the MEA that is a component of the fuel cell shown in FIG. 3 is an exploded perspective view of a single cell that is a component of the fuel cell shown in FIG. 1, FIG. 4 is a plan view of a resin frame that is a component of the fuel cell shown in FIG. Is a cross-sectional view taken along the line V-V shown in FIG. 4, FIG. 6 is a cross-sectional view schematically showing a method of connecting single cells that are components of the fuel cell shown in FIG. 1, and FIG. It is an enlarged view which shows typically a part of connection structure of the single cell which is a component of the fuel cell shown in FIG.

  In each figure, the thickness, size, enlargement / reduction ratio, and the like of each member are shown without matching with actual ones for easy understanding. In addition, the resin frame according to the present embodiment is dotted with a plurality of through holes. However, in order to make the explanation easy to understand, one through hole is formed on each side of the resin frame in FIG. It is described as such. Furthermore, in FIG. 7, the state around one through hole is schematically shown for easy understanding.

  The fuel cell described in the present embodiment is a solid polymer electrolyte fuel cell, and can be mounted on, for example, a fuel cell vehicle, but may be used other than the vehicle.

  As shown in FIGS. 1 to 7, the fuel cell 1 according to the present embodiment includes an MEA (membrane-electrode assembly) 10, a resin frame 21 disposed on one surface of the MEA 10, and the other of the MEA 10. The resin frame 22 disposed on the surface, the separator 23 disposed on the surface of the resin frame 21 opposite to the side on which the MEA 10 is disposed, and the side on which the MEA 10 of the resin frame 22 is disposed And a single cell 25 formed by overlapping a separator 24 disposed on the opposite surface, and a plurality of single cells 25 are stacked, and a terminal 30, an insulator 31, an end plate 32 are provided at both ends of the cell stacking direction. To form the stack 33, tighten the stack 33 in the cell stacking direction, and extend the fastening member 34 (for example, a tension plate, screw) extending in the cell stacking direction outside the stack 33. Boruto etc.) and consists of those bolted 35 or nut.

  The MEA 10 is disposed on one surface of the electrolyte membrane 11 made of an ion exchange membrane, the electrolyte membrane 11, an anode electrode (fuel electrode) 14 made up of the catalyst layer 12 and the diffusion layer 13, and the other of the electrolyte membrane 11. The cathode electrode (oxidant electrode) 17 composed of the catalyst layer 15 and the diffusion layer 16 is provided on the surface.

The resin frame 21 is disposed on the anode electrode 14 side of the MEA 10, and the resin frame 22 is disposed on the cathode electrode 17 side of the MEA 10. The resin frames 21 and 22 are hollowed out so that the power generation section of the MEA 10 is exposed to the separators 23 and 24, and manifold sections 40A and 40B are formed on both sides thereof. The manifold section 40A is provided with an inlet side cooling water manifold 41 _IN , an outlet side fuel gas manifold 42 _OUT , and an inlet side air manifold 43 _IN . On the other hand, the manifold section 40B is provided with an outlet side cooling water manifold 41 _OUT , an inlet side fuel gas manifold 42 _IN , and an outlet side air manifold 43 _OUT . Further, the resin frames 21 and 22 are formed with gas flow passage communication portions 47 that communicate the manifold portions 40A and 40B with the gas flow passage portions 53 and 54 formed in the separators 23 and 24, respectively.

  In the resin frames 21 and 22, a region that can be bonded to the separators 23 and 24 (a region indicated by halftone dots in FIG. 4, hereinafter simply referred to as “bondable region”) penetrates in the stacking direction of the single cells 25. A plurality of holes 60 are formed. The plurality of through-holes 60 are scattered in the region where the resin frames 21 and 22 can be bonded, and an adhesive 70 and a resin for bonding the resin frame 21 and the separator 23 when the single cell 25 is formed. An adhesive 70 for adhering the frame 22 and the separator 24 and an adhesive 70 for adhering the resin frame 21 and the resin frame 22 pass therethrough. That is, as shown in FIGS. 6 and 7, an adhesive 70 applied between the resin frame 21 and the separator 23, an adhesive 70 applied between the resin frame 21 and the resin frame 22, and a resin Resin frames 21 and 22 in which an adhesive 70 applied between the frame 22 and the separator 24 cooperates with each other through the through-hole 60 and is laminated on both surfaces of the MEA 10 to sandwich the MEA 10; Since the separators 23 and 24 are firmly bonded, the bonding strength between the members can be improved as compared with the conventional single cell. The shape of the through-hole 60 is not particularly limited as long as it penetrates in the cell stacking direction, and can be arbitrarily determined as desired, for example, a substantially cylindrical shape, a substantially polygonal column shape, or the like. Moreover, the through-hole which became bellows shape (unevenness | corrugation was formed) along the penetration direction may be sufficient.

  Further, the adhesive 70 is present between the resin frame 21 and the separator 23, between the resin frame 21 and the resin frame 22, and between the resin frame 22 and the separator 24 in a state of passing through the through hole 60. Therefore, as compared with the case where the through-hole 60 is not formed, the existence area (existing volume) becomes large, so that the optimum application amount of the adhesive 70 can be easily controlled. Furthermore, since the through hole 60 is not formed at the outer peripheral ends (end surfaces) of the resin frames 21 and 22, it is possible to suppress the adhesive 70 from protruding from the outer peripheral ends of the resin frames 21 and 22. Therefore, an adhesive burr is hardly formed on the outer peripheral ends of the resin frames 21 and 22. Moreover, since the through hole 60 also plays a role of releasing the adhesive 70 and air, it is not necessary to separately form holes and grooves for releasing the adhesive 70 and air in the resin frames 21 and 22, which is advantageous in processing. It is.

The separators 23 and 24 are impermeable, and can be composed of, for example, a stainless plate plated with a conductive metal (for example, nickel plating). These separators 23 and 24 constitute a conductive path between adjacent cells. A gas flow channel portion 53 in which a fuel gas flow channel 53A is formed is formed on the surface of the separator 23 facing the MEA 10 (the surface facing the MEA 10 side). A cooling water passage 55 is formed on the surface of the separator 23 opposite to the surface on which the gas passage portion 53 is formed. Further, a gas flow channel portion 54 in which an oxidizing gas flow channel 54A is formed is formed on the surface of the separator 24 that faces the MEA 10, and is opposite to the surface on which the gas flow channel portion 54 of the separator 24 is formed. A cooling water channel 56 is formed on the surface. The separators 23 and 24 also have the aforementioned inlet-side cooling water manifold 41 _IN , outlet-side fuel gas manifold 42 _OUT , inlet-side air manifold 43 _IN , outlet-side cooling water manifold 41 _OUT , and inlet-side fuel gas. A manifold 42 _IN and an outlet air manifold 43 _OUT are formed.

  The fuel gas channel 53A and the oxidizing gas channel 54A correspond to each other with the MEA 10 interposed therebetween. Further, the cooling water channel 55 formed in the separator 23 and the cooling water channel 56 formed in the separator 24 communicate with each other without being separated in the cell stacking direction.

  The separator 23 and the resin frame 21 constitute a separator-resin frame assembly, and the separator 24 and the resin frame 22 constitute a separator-resin frame assembly.

This single cell 25 can be manufactured including the following manufacturing method. That is, the inlet side cooling water manifold 41 _IN , the outlet side fuel gas manifold 42 _OUT , the inlet side air manifold 43 _IN , the outlet side cooling water manifold 41 _OUT , the inlet side fuel gas manifold 42 _IN , and the outlet side air A plurality of through holes 60 are formed in the adherable region of the resin frames 21 and 22 where the manifold 43 _OUT , the gas flow path communication portion 47, the hollows where the MEA 10 is exposed, and the like are formed. At this time, the installation location and the number of installation of the through hole 60 can be arbitrarily determined as desired. Moreover, after forming the through-hole 60, you may form various manifolds, the gas flow path communication part 47, hollowing, etc. which were mentioned above.

  Next, the adhesive 70 is disposed between the separator 23 and the resin frame 21 in the region where the resin frame 21 can be bonded. At this time, the adhesive 70 may be applied to the resin frame 21 side, may be applied to the separator 23 side, or may be applied to both. Next, the resin frame 21 and the separator 23 are bonded together with an adhesive 70 and bonded together to form a separator-resin frame assembly. At this time, the adhesive 70 enters the through hole 60 and penetrates, and the resin frame 21 and the separator 23 are firmly bonded. Similarly, the resin frame 22 and the separator 24 are also joined.

  Next, the separator-resin frame assembly described above is laminated on both surfaces of the MEA 10. At this time, the adhesive 70 penetrating from the through hole 60 is attached to the adhesive region of the surface facing the MEA 10 of the resin frame 21, and the adhesive region of the surface of the resin frame 22 facing the MEA 10 is Since the adhesive 70 penetrating from the through hole 60 is attached, the resin frame 21 and the resin frame 22 are firmly joined by the adhesive 70. In this manner, the resin frames 21 and 22 and the separators 23 and 24 that sandwich the MEA 10 are firmly bonded to each other by the adhesive 70 that penetrates the through hole 60 and is integrated.

  In the present embodiment, the through hole 60 penetrating in parallel to the cell stacking direction has been described. However, the present invention is not limited to this. For example, the through hole 60 may have a desired shape with respect to the cell stacking direction as shown in FIG. It may be inclined at an angle α.

  In the present embodiment, the case where the resin frames 21 and 22 and the separators 23 and 24 are bonded by the integrated adhesive 70 has been described. However, the present invention is not limited thereto, and the through holes 60 are formed in the resin frames 21 and 22. If the resin frame 21 and the separator 23 are bonded by the adhesive 70 penetrating the through hole 60, and the resin frame 22 and the separator 24 are bonded by the adhesive 70 penetrating the through hole 60, for example, Further, another member may be interposed between the resin frame 21 and the resin frame 22.

It is the whole schematic figure in the posture which made the cell lamination direction of the fuel cell concerning this embodiment the up-and-down direction. It is sectional drawing which expands and shows a part of MEA which is a component of the fuel cell shown in FIG. It is a disassembled perspective view of the single cell which is a component of the fuel cell shown in FIG. It is a top view of the resin frame which is a component of the fuel cell shown in FIG. It is sectional drawing along the VV line shown in FIG. It is sectional drawing which shows typically the connection method of the single cell which is a component of the fuel cell shown in FIG. FIG. 2 is an enlarged view schematically showing a part of a single cell connection structure which is a component of the fuel cell shown in FIG. 1. It is sectional drawing which expands and shows a part of resin frame concerning other embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell, 10 ... MEA, 21, 22 ... Resin frame, 23, 24 ... Separator, 25 ... Single cell, 60 ... Through-hole, 70 ... Adhesive

Claims (5)

An electrolyte-electrode assembly in which an anode electrode is disposed on one surface of an electrolyte and a cathode electrode is disposed on the other surface; a separator-resin frame assembly in which a separator and a resin frame are bonded with an adhesive; A fuel cell formed by laminating the separator-resin frame assembly on both sides of the electrolyte-electrode assembly with the resin frame surface facing the electrolyte-electrode assembly,
A fuel cell in which a through-hole through which the adhesive penetrates is formed in a region where the resin frame can be bonded to the separator.   The fuel cell according to claim 1, wherein the through hole penetrates in the stacking direction.   The adhesive includes a through hole formed in a resin frame laminated on one surface of the electrolyte-electrode assembly, and a penetration formed in a resin frame laminated on the other surface of the electrolyte-electrode assembly. The fuel cell according to claim 1 or 2, wherein both the holes are penetrated. An electrolyte-electrode assembly in which an anode electrode is disposed on one surface of an electrolyte and a cathode electrode is disposed on the other surface, and a separator-resin frame assembly formed by joining a separator and a resin frame. A method of manufacturing a fuel cell comprising: stacking the separator-resin frame assembly on both sides of the electrolyte-electrode assembly with the resin frame surface facing the electrolyte-electrode assembly,
Forming a through-hole through which an adhesive penetrates in a region where the resin frame can be bonded to the separator;
Bonding the separator and the resin frame with an adhesive penetrating the through hole to form a separator-resin frame assembly;
The separator-resin frame assembly is laminated on both sides of the electrolyte-electrode assembly, the resin frame laminated on one surface of the electrolyte-electrode assembly, and the other surface of the electrolyte-electrode assembly Bonding the resin frame made with an adhesive penetrating the through hole;
A fuel cell manufacturing method comprising:   The adhesive is bonded to both the through hole formed in the resin frame laminated on one surface of the electrolyte-electrode assembly and the through hole formed in the resin frame laminated on the other surface of the electrolyte-electrode assembly. The method for producing a fuel cell according to claim 4, further comprising a step of penetrating the agent.

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