JP2005174805A - Cell for fuel battery and manufacturing method of the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cell for a fuel battery surely held in a state that respective layers constituting the cell for the fuel battery are properly jointed to one another. <P>SOLUTION: Respective layers constructing a lamination body 14 are held by superposing an anode separator 12, an electrolyte film 11, and a cathode separator 13 having through-holes 12A, 11A, and 13A, respectively; hot press is applied on them; a lamination body reinforcing member 20 is inserted through the through-holes 12A, 11A, and 13A; and by making both ends of the lamination body reinforcing member 20 swell so as to have a diameter larger than that of the middle part thereof, by applying thermal caulking thereon. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell and a method for manufacturing the fuel cell, and more particularly to a technique for preventing separation between an electrolyte membrane and separators disposed on both surfaces thereof.

  The fuel cell is a unit cell of the fuel cell, and a fuel cell is configured by stacking a plurality of fuel cell cells to form a stack structure. In such a fuel cell, a separator having a fuel flow path is bonded to one surface of the electrolyte membrane, and a plate-shaped separator having an oxidant flow channel is bonded to the other surface of the electrolyte membrane. It is comprised by letting.

  As a fuel cell stacking method, an electrolyte membrane and a separator sandwiching the electrolyte membrane are sequentially stacked to form a stack (unit block) constituting a plurality of fuel cell cells, and a plurality of stacks are stacked. A method of holding and fixing is known (see, for example, Patent Document 1).

  FIG. 6 shows this stacking method. The electrolyte membrane 1 and the separators 2 and 3 used in this method are formed with positioning through holes at predetermined positions. First, in FIG. 6A, the through holes of the electrolyte membrane 1 and the separators 2 and 3 are fitted to the intermediate adapter 4 in consideration of the stacking order, and the unit block 5 as shown in FIG. 6B is manufactured. .

  Next, the plurality of unit blocks 5 produced in this way are stacked, and the shaft 6 is inserted into the cylindrical holes of the plurality of intermediate adapters 4 communicated with each other.

  Thereafter, the plurality of unit blocks 5 are fastened with fixing members from both ends of the shaft 6 so as to be in pressure contact with each other. In this way, the fuel cell stack is manufactured.

The intermediate adapter 4 described above has a function of connecting the stacked layers and a function as a sealing agent. Such an intermediate adapter 4 is formed of a resin material. Examples of the resin material include thermosetting resins and silicone resins. Moreover, in order to produce the unit block 5, generally the method of giving pressure and heating and hardening resin is performed. In such a stacking method, as shown in FIG. 7, a known hot press 9 including a mounting plate 7 for mounting the unit block 5 and a pressure plate 8 for pressing the unit block 5 from above is used. ing. The mounting plate 7 and the pressure plate 8 incorporate a heater for heating (not shown).
JP 2001-57226 A (page 3, FIG. 1)

  However, in the fuel cell manufacturing method described above, the pressure is generated when the pressure is released after the pressure plate 8 is released from the stack after the stack is pressed and heated by a hot press. Due to the repulsive force that has been generated, there is a problem that the seal between the intermediate adapter 4 and the inner wall portion of each layer is easily peeled (separated). This problem occurred in the same manner even when the pressure was released after the laminate was cooled. The reason is that the intermediate adapter 4 is sealed by surface contact of each layer and the inner wall surface of the through hole, and each layer is easily displaced in the axial direction of the intermediate adapter 4.

  Further, in this conventional method, there is a problem in that the joint between the electrolyte membrane 1 and the separators 2 and 3 is also peeled off due to the seal between the intermediate adapter 4 and each layer being peeled off.

  Accordingly, an object of the present invention is to provide a method for producing a fuel cell with a small number of work steps, and a highly durable fuel cell, while preventing the layers constituting the fuel cell from peeling off. .

  In order to solve the above-described problems, the present invention provides a method for manufacturing a fuel cell, wherein an anode separator is stacked on one main surface of an electrolyte membrane, and a cathode separator is stacked on the other main surface of the electrolyte membrane. To form a laminate. And after this laminated body is hot-pressed, the laminated body reinforcement member which consists of resin which has electrical insulation is inserted in the through-hole penetrated in the thickness direction of a laminated body. Thereafter, the laminated body reinforcing member is heated and melted, and then cooled.

  According to the present invention, it is possible to provide a fuel cell that is reliably held in a state where the electrolyte membrane, anode separator, and cathode separator layers constituting the fuel cell are appropriately joined. Moreover, according to this invention, the cell for fuel cells can be manufactured with few man-hours.

  Hereinafter, a fuel cell manufacturing method and a fuel cell according to the best mode for carrying out the present invention will be described.

  First, the manufacturing method of the fuel cell to which the present invention is applied and the configuration of the fuel cell are outlined.

  When manufacturing the fuel cell according to the present embodiment, as the electrolyte membrane, the anode separator, and the cathode separator, those in which through holes are formed at positions corresponding to the laminated layers are used. And it laminates | stacks so that an anode separator may be joined to one main surface of an electrolyte membrane, and it laminates | stacks so that a cathode separator may be joined to the other main surface of this electrolyte membrane, and a laminated body is produced. In addition, the recessed part which is integral with a through-hole and is connected to a through-hole is formed in the surface of the lamination direction both sides of this laminated body. The recess is formed larger than the diameter of the through hole.

  Next, after hot pressing this laminate, it is cooled by cold pressing. After that, a screw-shaped laminated body reinforcing member having a huge head made of a resin having electrical insulation is inserted into the communicating through-hole while maintaining the cold-pressed state. At this time, the enormous head portion of the laminated body reinforcing member is accommodated in a recess formed in one outermost layer in the laminating direction of the laminated body.

  Next, in a state of being inserted into the through hole, the laminated body reinforcing member is heated and melted, and then cooled. At this time, the other end of the laminated body reinforcing member is melted and accommodated in a recess formed in the other outermost layer in the lamination direction of the laminated body, and is cooled and cured in this state.

  The fuel cell produced through these steps is a so-called peeling prevention reinforcement in which each layer of the electrolyte membrane, anode separator and cathode separator constituting the laminate is provided so as to penetrate in the lamination direction. It becomes a structure hold | maintained by each laminated body reinforcement member which functions as a member. In particular, in the present embodiment, since both ends of the laminated body reinforcing member have a so-called flange shape, the laminated body is held in a state of being pressed in the joining direction.

  Next, a fuel cell and a method for manufacturing the fuel cell according to an embodiment of the present invention will be described in detail with reference to the drawings. However, it should be noted that the drawings are schematic and ratios of dimensions of the members are different from actual ones. Therefore, specific dimensions should be determined in consideration of the following description.

  In the method for manufacturing a fuel cell according to the present embodiment, as shown in FIG. 1, an electrolyte membrane 11, an anode separator 12 disposed on one main surface of the electrolyte membrane 11, and the other of the electrolyte membrane 11. The present invention is applied to a case where the laminated body 14 including the cathode separator 13 disposed on the main surface is a fuel cell. The anode separator 12 has a fuel (hydrogen-rich gas) flow path (not shown), and the cathode separator 13 has an oxidant flow path (not shown) for circulating air.

  As shown in FIG. 1 (a), in this embodiment, the electrolyte membrane 11, the anode separator 12 and the cathode separator 13 constituting the laminate 14 have the same shape and the same shape at predetermined positions (positions other than the battery functional area). Through holes 11A, 12A, and 13A having dimensions are formed. In the present embodiment, these through holes 11A, 12A, and 13A are formed at the four corners of each electrolyte membrane 11, anode separator 12, and cathode separator 13, respectively. Further, a circular recess 12B is formed at the opening peripheral edge of the through hole 12A on the surface (outside) opposite to the stacking direction of the anode separator 12 so as to widen the diameter of the through hole 12A. Similarly, a circular recess 13B is formed at the opening peripheral portion of the through hole 13A on the surface (outer side) opposite to the stacking direction of the cathode separator 13 so as to widen the diameter of the through hole 13A.

  In this embodiment, as shown in FIG. 1 (a), the anode separator 12, the electrolyte membrane 11, and the cathode separator 13 are sequentially laminated so that the through holes 12A, 11A, and 13A match each other. To do.

  Next, as shown in FIG. 1A, the laminate 14 is hot pressed by a hot press device 15. The hot press device 15 includes a mounting plate 16 on which the stacked body 14 is mounted, and a pressurizing plate 17 that can be moved up and down to pressurize the stacked body 14. The mounting plate 16 and the pressure plate 17 include heating means such as a heater and cooling means. Further, in the mounting plate 16 and the pressure plate 17, heat caulking jigs 18 and 19 to be described later are inserted into positions (for example, four places) corresponding to the through holes 11 </ b> A, 12 </ b> A and 13 </ b> A that communicate with the stacked body 14. Jig insertion holes 16A and 17A are opened. The stacked body 14 is placed on the press device 15 having such a configuration so that the communicating through holes 11A, 12A, and 13A correspond to the jig insertion holes 16A of the placement plate 16.

  When the hot pressing step is completed, the mounting plate 16 and the pressure plate 17 are cooled by the cooling means in a state where the laminated body 14 is pressurized by the pressing device 15 and cold-pressed. Thereafter, the laminate reinforcing member 20 is inserted from the cathode separator 13 side as shown in FIG. This laminate reinforcing member 20 is formed by forming an insulating resin such as polybutylene terephthalate (PBT) or polyphenylene sulfide (PPS) in a rivet shape, and a flange-shaped enormous head 20A is formed at one end. Has been.

  The enormous head portion 20A is substantially the same as or slightly smaller than the space shape in the recess 13B formed in the cathode separator 13. Further, as shown in FIG. 1B, the length of the laminate reinforcing member 20 is such that the inserted end projects from the outer surface of the anode separator 12 when inserted into the laminate 14. Is set. More specifically, the volume of the portion of the laminate reinforcing member 20 that protrudes from the bottom surface of the recess 12B of the anode separator 12 is set to be substantially the same as the volume of the recess 12B.

  Next, as shown in FIG. 1 (b), the heat caulking jigs 18 and 19 are inserted into the jig insertion holes 16 A and 17 A of the mounting plate 16 and the pressure plate 17, and pushed to both ends of the laminate reinforcing member 20. The heat is applied to the end of the laminated body reinforcing member 20 and crimped. At this time, the end portion of the laminate reinforcing member 20 protruding from the anode separator 12 is processed into a flange-shaped enormous head portion 20B as shown in FIG. 1 (c) and is embedded in the recess 12B. Thereafter, the laminated body 14 is cold pressed. At this time, the compressive force generated by the shrinkage at the time of cooling of the insulating resin constituting the heated laminate reinforcing member 20 acts on the laminate 14, and the laminate 14 is firmly held in the stacking direction by the contraction force. The Then, by taking out from the press apparatus 15, manufacture of the finished product (cell for fuel cells) of the laminated body 14 as shown in FIG.1 (c) is complete | finished.

  In order to manufacture a fuel cell by stacking a plurality of stacked bodies (fuel cell) 14 manufactured in this way, as shown in FIG. 2, between the stacked bodies 14 (fuel cell), for example, What is necessary is just to match | combine with the rubber seal 21 interposed.

  In the method for manufacturing a fuel cell according to the present embodiment, the fuel cell can be completed in a state where the laminate 14 is placed on the press device 15, and therefore the number of steps can be reduced.

  Moreover, since the joining state is hold | maintained at the huge head of the both ends of the laminated body reinforcement member 20, the laminated body 14 can prevent that each layer peels.

  In addition, according to the present invention, the laminated body reinforcing member 20 made of an insulating resin is inserted into the through hole formed in the laminated body 14 in which the electrolyte membrane 11 is sandwiched between the anode separator 12 and the cathode separator 13, and the laminated body reinforcing member Since the laminated body 14 is clamped in the laminating direction by caulking 20, the laminated body reinforcing member 20 suppresses the force to return from the pressurizing when releasing the pressurization after the laminated body pressurizing. Thus, peeling of these layers can be reliably prevented.

  FIG. 3 shows a method for manufacturing a fuel cell according to Example 2 of the present invention. In Example 2, the shapes of the electrolyte membrane 11, the anode separator 12, and the cathode separator 13 are the same as those in Example 1 described above.

  In this embodiment, the molten resin is injected into the through holes 11A, 12A, 13A and the recesses 13B, 12B formed in the stacked body 14 without using the stacked body reinforcing member 20 as in the first embodiment. The method of sealing is used.

  As shown in FIG. 3, the resin is poured from a gate 23 </ b> A formed on the pressure plate 23 of the press device 15. Although not shown, the mounting plate 22 on which the stacked body 14 is mounted has a small hole through which air escapes as the resin is filled.

In the present embodiment, the hot press step, the cooling step, the resin filling step, and the resin cooling step can be performed consistently while the laminate 14 is being pressed by the mounting plate 22 and the pressure plate 23. Therefore, smooth manufacture can be performed. Needless to say, the laminate 14 manufactured in this manner has the same effects as those of the first embodiment.
[Modification]

  4 and 5 show a cross section of a modified example of the laminate (fuel cell) 14 as a finished product.

  In the modification shown in FIG. 4, the enormous head 20 </ b> A of the laminated body reinforcing member 20 and the enormous head at the inserted end are in contact with the outer surfaces of the cathode separator 13 and the anode separator 12. Accordingly, it is not necessary to form the recesses 12B and 13B on the surfaces of the anode separator 12 and the cathode separator 13.

  In this modification, the end portion of the laminated body reinforcing member 20 protrudes from the outer surface of the cathode separator 13 or the anode separator 12, but this protrusion is caused by the thickness of the rubber seal material interposed when the laminated bodies 14 are stacked. This can be absorbed in the production of fuel cells. In addition, this modification can be manufactured by the method of Example 1 mentioned above.

  5 is a shape in which the enormous head 20C at one end and the enormous head 20D at the other end of the laminate reinforcing member 20 are gradually narrowed from the end surface toward the intermediate portion of the laminate reinforcing member 20. . Further, the enormous head 20C and the enormous head 20D are embedded in the recesses formed in the cathode separator 13 and the anode separator 12 so as not to protrude from the surfaces of the separators 13 and 12. In addition, these recessed parts have a mortar-shaped taper surface. This modification can be manufactured by the method of the first embodiment and the second embodiment described above.

(Other examples)
Although the embodiment has been described above, it should not be understood that the description and drawings constituting a part of the disclosure of the embodiment limit the present invention, and various modifications accompanying the gist of the configuration are possible. is there.

  For example, in Example 1 and Example 2 described above, three sheets of the anode separator 12, the electrolyte membrane 11, and the cathode separator 13 constituting one set of fuel cell are hot-pressed. The number of cells constituting the working cell may be hot pressed at a time.

(A)-(c) is process sectional drawing which shows the manufacturing method of the cell for fuel cells which concerns on Example 1 of this invention. It is sectional drawing which shows the structure which laminated | stacked the cell for fuel cells manufactured in Example 1 of this invention. It is process sectional drawing which shows the manufacturing method of the cell for fuel cells which concerns on Example 2 of this invention. It is sectional drawing which shows the modification of the cell for fuel cells manufactured in Example 1 of this invention. It is sectional drawing which shows the modification of the cell for fuel cells manufactured in Example 1 and Example 2 of this invention. (A)-(c) is a perspective view which shows the manufacturing process of the conventional fuel cell. It is explanatory drawing which shows the hot press process in the manufacturing method of the conventional fuel cell.

Explanation of symbols

DESCRIPTION OF SYMBOLS 11 ... Electrolyte membrane, 12 ... Anode separator, 13 ... Cathode separator, 14 ... Laminated body, 15 ... Press apparatus, 20 ... Laminate reinforcement member, 20A ... Enormous head, 20B ... Enormous head Part

Claims (6)

Laminating an anode separator on one principal surface of the electrolyte membrane, laminating a cathode separator on the other principal surface of the electrolyte membrane to form a laminate, and hot pressing the laminate;
Inserting a laminate reinforcing member made of a resin having electrical insulation into a through-hole penetrating in the thickness direction of the laminate; and
Cooling the laminate reinforcing member after heating and melting;
A method for producing a cell for a fuel cell, comprising: Laminating an anode separator on one principal surface of the electrolyte membrane, laminating a cathode separator on the other principal surface of the electrolyte membrane to form a laminate, and hot pressing the laminate;
Filling a through-hole penetrating in the thickness direction of the laminate in a molten state with a resin having electrical insulation;
Cooling the resin to form a laminate reinforcing member;
A method for producing a cell for a fuel cell, comprising: A method for manufacturing a fuel cell according to claim 1 or 2, wherein
A method for manufacturing a cell for a fuel cell, characterized in that enormous heads having a diameter larger than that of an intermediate portion are formed at both ends of the laminate reinforcing member. A method for producing a fuel cell according to claim 3,
A method for manufacturing a fuel cell, comprising: forming a recess for embedding the enormous head on the surface of the outermost layer on both sides in the stacking direction of the stack.   A laminate made of a resin having electrical insulation in a through-hole penetrating in the thickness direction of a laminate in which an anode separator is joined to one main surface of the electrolyte membrane and a cathode separator is joined to the other main surface of the electrolyte membrane A fuel cell according to claim 1, wherein a body reinforcing member is embedded, and enlarging heads having a diameter larger than a diameter of an intermediate portion of the through hole are formed at both ends of the laminated body reinforcing member. A fuel cell according to claim 5, wherein
Both ends of the through hole have a recessed shape for accommodating the enormous head portion of the laminated body reinforcing member.

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