JP2010123491A - Apparatus for manufacturing membrane electrode assembly - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an apparatus for manufacturing a membrane electrode assembly, which can suppress a lack in bonding strength between a laminate in which an anode electrode and a cathode electrode are laminated to an electrolyte membrane, and a resin part. <P>SOLUTION: The apparatus 200 for manufacturing the membrane electrode assembly includes an anode abutting section 211 abutting the anode electrode 22, a cathode abutting section 221 abutting the cathode electrode 23, and molding sections 214, 224 to demarcate a molding chamber 240 to mold a resin frame on the peripheral end of the laminate 24 interposed between the anode abutting section 211 and the cathode abutting section 221. In the molding sections 214, 224, a flow control section 227 is provided which controls the flow of a resin material so that the resin material injected into the molding chamber 240 and flowing from the outer end side of the molding chamber to the peripheral end of the laminate flows toward a gas diffusion layer of one electrode of the anode electrode 22 and the cathode electrode 23. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to an apparatus for manufacturing a membrane electrode assembly of a fuel cell.

  2. Description of the Related Art Conventionally, a fuel cell that directly converts chemical energy into electrical energy by an electrochemical reaction using an anode gas containing hydrogen and a cathode gas containing oxygen as a reaction gas is known.

Patent Document 1 discloses a fuel cell in which an anode electrode is disposed on one surface of an electrolyte membrane, a cathode electrode is disposed on the other surface to form a laminate, and a resin portion is integrally formed on the outer peripheral end of the laminate. Membrane Electrode Assembly (hereinafter referred to as “MEA”) is disclosed. Since this MEA includes a resin portion, the sealing property between the MEA and the separator is enhanced, and the mechanical strength of the MEA itself is increased to improve the handling property.
JP 2008-41337 A

  By the way, in Patent Document 1, a molten resin material is injected into a mold to form a resin portion at the outer peripheral end of the laminate, but the flow state of the resin material injected into the mold is considered. Not. Therefore, in the MEA described in Patent Document 1, it is difficult for the resin material to permeate the gas diffusion layers of the anode and cathode of the laminate, and the bonding strength between the laminate and the resin portion may be insufficient.

  Therefore, the present invention has been made in view of the above-described problems, and the bonding strength between the laminate in which the anode electrode and the cathode electrode are laminated on the electrolyte membrane and the resin portion integrally formed on the outer peripheral end of the laminate is insufficient. It aims at providing the manufacturing apparatus of the membrane electrode assembly which can suppress this.

  The present invention solves the above problems by the following means.

  The present invention relates to a membrane electrode for producing a membrane electrode assembly by forming a resin material on an outer peripheral end of a laminate in which an anode electrode is arranged on one surface of an electrolyte membrane and a cathode electrode is arranged on the other surface. It is a joined body manufacturing apparatus. The membrane electrode assembly manufacturing apparatus includes an anode abutting portion that abuts on the anode electrode, a cathode abutting portion that abuts on the cathode electrode, and an outer peripheral end portion of the laminate sandwiched between the anode abutting portion and the cathode abutting portion. And a molding part that defines a molding chamber for molding the resin part. In this molding part, the resin material that is injected into the molding chamber and flows from the outer edge of the molding chamber to the outer peripheral end of the laminate flows toward the gas diffusion layer of one of the anode electrode and the cathode electrode. A flow control unit for controlling the flow of the material is provided.

  According to the present invention, since the resin material that permeates the outer peripheral edge of the laminate flows toward the gas diffusion layer of the electrode, it is possible to manufacture a membrane electrode assembly with sufficient bonding strength between the laminate and the resin portion. it can.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
(First embodiment)
A fuel cell stack for a vehicle is configured by stacking a plurality of single cells that are solid polymer fuel cells.

  FIG. 1 is a diagram showing a partial cross section in the stacking direction of adjacent single cells 10 in the fuel cell stack 100.

  The single cell 10 of the fuel cell stack 100 includes an MEA 20 and an anode separator 32 and a cathode separator 33 that are arranged so as to sandwich the MEA 20.

  The MEA 20 is a laminate 24 in which an anode electrode 22 is disposed on one surface of an electrolyte membrane 21 and a cathode electrode 23 is disposed on the other surface, and a resin frame 25 is integrally formed on the outer peripheral end of the laminate 24. Configured.

  The electrolyte membrane 21 is a proton conductive ion exchange membrane formed of a fluorine resin. The electrolyte membrane 21 is larger in outer shape than the cathode electrode 23 and has an outer edge portion 21A where the cathode electrode 23 is not disposed. Since the electrolyte membrane 21 exhibits good electrical conductivity in a wet state, the fuel cell stack 100 humidifies the anode gas and the cathode gas.

  The anode electrode 22 is formed in substantially the same shape as the electrolyte membrane 21, and includes a catalyst layer 22A and a gas diffusion layer 22B. The catalyst layer 22 </ b> A of the anode electrode 22 is formed from platinum or carbon black particles carrying platinum or the like and is in contact with the electrolyte membrane 21. The gas diffusion layer 22 </ b> B of the anode electrode 22 is provided outside the catalyst layer 22 </ b> A and is in contact with the anode separator 32. The gas diffusion layer 22B is formed of a member having sufficient gas diffusibility and conductivity, and is formed of, for example, a carbon cloth woven with yarns made of carbon fibers.

  The cathode electrode 23 is formed so as to have a smaller outer shape than the electrolyte membrane 21, and is disposed so as to fit within the outer shapes of the electrolyte membrane 21 and the anode electrode 22. Similarly to the anode electrode 22, the cathode electrode 23 includes a catalyst layer 23A and a gas diffusion layer 23B. The catalyst layer 23A of the cathode electrode 23 is in contact with the electrolyte membrane 21, and the gas diffusion layer 23B is provided outside the catalyst layer 23A and is in contact with the cathode separator 33.

  The resin frame 25 is a frame body made of synthetic resin or the like, and is integrally formed at the outer peripheral end of the laminate 24. The resin frame 25 is in close contact with the anode separator 32 and the cathode separator 33 to suppress leakage of fuel gas and the like, and increases the mechanical strength of the MEA itself to improve the handling property of the MEA 20.

  The anode separator 32 is an uneven plate member made of a conductive material such as metal. The anode separator 32 forms an anode gas flow path 32 </ b> A through which an anode gas flows on the surface in contact with the anode electrode 22. The anode separator 32 forms a cooling water passage 32 </ b> B through which cooling water for cooling the fuel cell stack 100 flows on the surface opposite to the side in contact with the anode electrode 22.

  The cathode separator 33 is an uneven plate member made of a conductive material such as metal. The cathode separator 33 forms a cathode gas flow path 33 </ b> A through which the cathode gas flows on the surface in contact with the cathode electrode 23. The cathode separator 33 forms a cooling water flow path 33 </ b> B through which cooling water for cooling the fuel cell stack 100 flows on the surface opposite to the side in contact with the cathode electrode 23.

  In the adjacent single cells 10, the cooling water flow paths 32B and 33B provided in the anode separator 32 of one single cell 10 and the cathode separator 33 of the other single cell 10 are configured to face each other. One cooling water channel 31 is formed by the cooling water channels 32B and 33B.

  The MEA manufacturing apparatus 200 of the present embodiment that manufactures the MEA 20 of the single cell 10 described above will be described with reference to FIGS. 2 (A) and 2 (B).

  FIG. 2A is a front view of the MEA manufacturing apparatus 200. FIG. 2B is a partial cross-sectional view of the MEA manufacturing apparatus 200 in the stacking direction of the stacked body 24 constituting the MEA 20.

  The MEA manufacturing apparatus 200 injects a molten resin material into a laminated body 24 in which the anode electrode 22 is disposed on one surface of the electrolyte membrane 21 and the cathode electrode 23 is disposed on the other surface. The MEA 20 is manufactured by integrally forming a resin frame 25 on the part.

  2A, the MEA manufacturing apparatus 200 includes an anode side mold 210, a cathode side mold 220, an anode side moving unit 231 that moves the anode side mold 210 in the stacking direction, and a cathode side. A cathode side moving unit 232 that moves the mold 220 in the stacking direction.

  The anode side mold 210 is horizontally disposed below the cathode side mold 220. The anode side mold 210 includes a contact portion 211 that contacts the anode electrode 22 and a frame wall portion 212 that is formed around the contact portion 211.

  The contact portion 211 of the anode side mold 210 contacts the anode electrode 22 through the contact surface 213 as shown in FIG. The anode side mold 210 forms a molding part 214 for molding a part of the resin frame 25 by the contact part 211 outside the contact surface 213 and the frame wall part 212.

  On the other hand, the cathode side mold 220 is disposed horizontally above the anode side mold 210 as shown in FIG. The cathode side mold 220 includes a contact portion 221 that contacts the cathode electrode 23 and a frame wall portion 222 that is formed around the contact portion 221.

  As shown in FIG. 2B, a contact surface 223 that protrudes from the contact portion 221 to the anode electrode side is formed on the contact portion 221 of the cathode side mold 220. The contact portion 221 contacts the cathode electrode 23 via the protruding contact surface 223. In the cathode side mold 220, a molding part 224 for molding a part of the resin frame 25 is formed by the contact part 221 outside the contact surface 223 and the frame wall part 222.

  The molding part 224 of the cathode side mold 220 and the molding part 214 of the anode side mold 210 are configured to face each other, and a molding chamber 240 for molding the resin frame 25 with the laminate 24 sandwiched therebetween. It becomes.

  The cathode side mold 220 is provided with a supply pipe 226 for supplying a molten resin material on each side of the frame wall portion 222. The resin material supplied from the supply pipe 226 is injected into the molding chamber 240 through the injection hole 225 formed in the frame wall portion 222. The injected resin material flows in a direction (resin material flow direction) from the outer edge side of the molding chamber 240 toward the outer peripheral end of the laminate 24 as indicated by an arrow in FIG.

  A protruding portion 227 that protrudes into the molding chamber 240 is formed along the periphery of the laminate 24 at the contact portion 221 on the molding portion side of the cathode side mold 220. The protruding portion 227 has a shape that does not hinder the flow of the resin material, and is formed such that the protruding height gradually increases in the resin material flow direction, and then the protruding height gradually decreases. The protrusion 227 is arranged so that the highest protrusion 227A having the highest protrusion height coincides with the vicinity of the end of the anode electrode 22 or the end of the anode electrode 22 in the resin material flow direction.

Incidentally, the height H _A of the molding chamber 240 during MEA fabrication is set to be 0.30～0.50Mm, protrusion 227 of the cathode-side mold 220 is 0.05 the highest projection height H _B 0.45 mm, the protruding end width W _B is set to be 0.50～3.00Mm. More preferably, the projecting portion 227 is best protruding height H _B is 0.10 to 0.30 mm, the projecting end width W _B are formed so as to 1.00～2.00Mm.

  In the MEA manufacturing apparatus 200 described above, when the MEA is manufactured, the anode side mold 210 is moved by the anode side moving unit 231, the cathode side mold 220 is moved by the cathode side moving unit 232, and the anode side mold 210 is contacted. The laminate 24 is sandwiched between the contact surface 213 and the contact surface 223 of the cathode side mold 220. Thereafter, the anode side mold 210 and the cathode side mold 220 are heated to a predetermined temperature, and a molten resin material is injected into the molding chamber 240. As a result, the resin frame 25 is integrally formed at the outer peripheral end of the laminate 24 to manufacture the MEA 20.

  By the way, in the conventional MEA manufacturing apparatus, since the flow state of the resin material injected into the mold is not considered, there is a problem that the bonding strength between the laminate and the resin frame is insufficient. Problems in the conventional MEA manufacturing apparatus will be described with reference to FIG.

  As shown in FIG. 5, the conventional MEA manufacturing apparatus 300 has substantially the same configuration as that of the MEA manufacturing apparatus 200 of the present embodiment, except that no protruding portion is formed on the cathode side mold 220 and the cathode side mold. The difference is that the contact surface 223 of the mold 220 does not protrude from the contact portion 221.

  In the MEA manufacturing apparatus 300, the injected resin material R flows from the outer edge side of the molding chamber 240 toward the outer peripheral end of the laminate 24 as shown in FIG. Since the resin material R in the vicinity of the anode side mold 210 and the cathode side mold 220 is cooled to increase the viscosity, the resin material R flows with a convex shape at the tip. Therefore, the tip of the resin material R contacts the electrolyte membrane 21 of the laminate 24 and the catalyst layer 22A of the anode electrode 22. When the resin material R comes into contact in this way, the gas diffusion layer 22B of the anode electrode 22 is pressed by the resin material R, so that the gas diffusion layer 22B is compressed as shown in a region A of FIG. When the gas diffusion layer 22B of the anode electrode 22 is compressed, voids in the gas diffusion layer 22B are reduced, so that the resin material R is less likely to penetrate into the gas diffusion layer 22B. As a result, in the MEA 20 manufactured by the MEA manufacturing apparatus 300, the bonding strength between the laminate 24 and the resin frame 25 is insufficient.

  In addition, the resin material R flows through the upper side of the electrolyte membrane 21 of the laminate 24 and flows to the outer peripheral end portion of the cathode electrode 23. Since the gas diffusion layer 22B of the anode electrode 22 is still compressed by the resin material R, a gap is formed between the cathode electrode 23 and the contact surface 223 of the cathode side mold 220, and the resin material R is formed in the gap. Inflow. When the resin material R flows in as shown in the region B in FIG. 5B, the power generation reaction surface of the cathode electrode 23 decreases. Therefore, in the MEA 20 manufactured by the MEA manufacturing apparatus 300, the power generation efficiency is deteriorated.

  On the other hand, in the MEA manufacturing apparatus 200 of the present embodiment, the projecting portion 227 of the cathode side mold 220 suppresses insufficient bonding strength between the laminate 24 and the resin frame 25, and the cathode side mold 220 abuts. The surface 223 suppresses a decrease in the power generation reaction surface of the cathode electrode 23.

  With reference to FIG. 3, manufacture of MEA 20 in MEA manufacturing apparatus 200 will be described.

  In the MEA manufacturing apparatus 200, as shown in FIG. 3A, the resin material R injected into the molding chamber 240 flows from the outer edge side of the molding chamber to the outer peripheral end of the laminate. Since the resin material R in the vicinity of the anode side mold 210 and the cathode side mold 220 is cooled to increase the viscosity, the resin material R flows with a convex shape at the tip. The resin material R is brought close to the anode electrode side by the protrusion 227 formed on the cathode side mold 220, and the tip of the resin material R contacts the outer peripheral end portion of the gas diffusion layer 22 </ b> B of the anode electrode 22. Since the tip of the resin material R has a lower viscosity than the mold side, when the tip of the resin material R comes into contact with the outer peripheral end of the gas diffusion layer 22B, the resin material R is as shown in FIG. It penetrates sufficiently into the gas diffusion layer 22B.

  The resin material R that has reached the outer peripheral end of the electrolyte membrane 21 of the laminate 24 flows into the upper side of the electrolyte membrane 21 and flows to the outer peripheral end of the cathode electrode 23. Even when flowing over the electrolyte membrane 21, the tip of the resin material R has a convex shape, and the tip of the resin material R contacts the outer peripheral end of the gas diffusion layer 23 </ b> B of the cathode electrode 23. Therefore, as shown in FIG. 3C, the resin material R sufficiently penetrates into the gas diffusion layer 23 </ b> B of the cathode electrode 23.

  In the MEA manufacturing apparatus 200, the contact surface 223 of the cathode side mold 220 is configured to protrude from the contact portion 221, and the gas diffusion layer 22 </ b> B of the anode electrode 22 is thickened by the contact surface 223. Pre-compress in the direction. Therefore, even if the resin material R flows into the upper side of the electrolyte membrane 21, no gap is generated between the gas diffusion layer 23B of the cathode electrode 23 and the cathode side mold 220. Therefore, the resin material R is suppressed from flowing between the gas diffusion layer 23 </ b> B of the cathode electrode 23 and the cathode side mold 220.

  3A to 3C, the MEA manufacturing apparatus 200 integrally forms the resin frame 25 at the outer peripheral end of the laminate 24 as shown in FIG. To manufacture.

  As described above, the MEA manufacturing apparatus 200 of the present embodiment can obtain the following effects.

  In the MEA manufacturing apparatus 200, a protruding portion 227 that protrudes into the molding chamber 240 is formed at the contact portion 221 of the cathode side mold 220, and the tip of the resin material R is formed at the gas diffusion layer 22 </ b> B of the anode electrode 22 by the protruding portion 227. The flow direction of the resin material R is controlled so that it goes to. As a result, the resin material R is sufficiently impregnated in the gas diffusion layer 22B of the anode electrode 22, so that insufficient bonding strength between the laminate 24 and the resin frame 25 in the manufactured MEA 20 can be suppressed.

  Since the protrusion 227 is formed as a smooth shape that does not hinder the flow of the resin material, the pressure loss of the resin material R flowing in the molding chamber 240 can be suppressed as much as possible.

  Further, since the laminate 24 arranged in the MEA manufacturing apparatus 200 is configured such that the cathode electrode 23 is contained within the outer shape of the anode electrode 22, the tip of the resin material R flowing into the upper side of the electrolyte membrane 21 is the cathode electrode. It flows toward the outer peripheral end of 23. As a result, the resin material R is sufficiently impregnated in the gas diffusion layer 23B of the cathode electrode 23, so that insufficient bonding strength between the laminate 24 and the resin frame 25 in the manufactured MEA 20 can be suppressed.

  Further, in the MEA manufacturing apparatus 200, the gas diffusion layer 22B of the anode electrode 22 is compressed in the thickness direction in advance by the contact surface 223 formed on the contact portion 221 of the cathode side mold 220. Even if it flows into the upper side of the electrolyte membrane 21, there is no gap between the cathode electrode 23 and the cathode side mold 220. As a result, the resin material R is prevented from flowing between the gas diffusion layer 23B of the cathode electrode 23 and the cathode side mold 220, so that the power generation efficiency of the MEA 20 due to the decrease in the power generation reaction surface of the cathode electrode 23 is reduced. Can be suppressed.

(Second Embodiment)
FIG. 4 is a partial cross-sectional view of the MEA manufacturing apparatus 200 according to the second embodiment in the stacking direction of the stacked body 24.

  The MEA manufacturing apparatus 200 of the second embodiment has substantially the same configuration as that of the first embodiment, but is different in that a recess 215 is formed in the anode side mold 210. Hereinafter, the difference will be mainly described.

  As shown in FIG. 4, in the MEA manufacturing apparatus 200, a recess 215 is formed in the contact portion 211 of the anode side mold 210 at a position facing the protruding portion 227 of the cathode side mold 220. The recess 215 is formed so as to be recessed according to the protruding height of the protruding portion 227.

  In the MEA manufacturing apparatus of the first embodiment, since the pressure of the resin material R increases when the resin material R flowing in the molding chamber 240 passes through the protruding portion 227, the increased pressure of the resin material R is the electrolyte membrane of the laminate 24. It is also conceivable that the gas diffusion layer 22 </ b> B of the anode electrode 22 is compressed when flowing over the upper side 21, and the resin material R slightly flows between the cathode electrode 23 and the cathode side mold 220.

  However, in the MEA manufacturing apparatus 200 of the second embodiment, since the concave portion 215 is formed in the anode side mold 210, even if the resin material R passes through the protruding portion 227, the high pressure of the resin material R is suppressed. Therefore, in the MEA manufacturing apparatus 200, the inflow of the resin material R between the cathode electrode 23 and the cathode side mold 220 can be suppressed as compared with the MEA manufacturing apparatus of the first embodiment.

  The present invention is not limited to the above-described embodiment, and it is obvious that various modifications can be made within the scope of the technical idea.

It is a partial cross section figure of a single cell. It is a schematic block diagram of the MEA manufacturing apparatus of 1st Embodiment. It is a figure explaining the flow of the resin material in the MEA manufacturing apparatus of 1st Embodiment. It is a partial cross section figure of the MEA manufacturing apparatus of 2nd Embodiment. It is a figure explaining the flow of the resin material in the conventional MEA manufacturing apparatus.

Explanation of symbols

10 single cell 21 electrolyte membrane 22 anode electrode 23 cathode electrode 24 laminate 25 resin frame (resin part)
200 MEA manufacturing apparatus 210 Anode side mold 211 contact part (anode contact part)
213 Contact surface 214 Molding portion 215 Concavity 220 Cathode side die 221 Contact portion (cathode contact portion)
223 Contact surface (projection contact surface)
224 Molding part 227 Protrusion part (flow control part)
240 Molding chamber R Resin material

Claims (7)

Membrane / electrode assembly manufacturing apparatus for manufacturing a membrane / electrode assembly by forming a resin material on the outer peripheral end of a laminate in which the anode electrode is disposed on one surface of the electrolyte membrane and the cathode electrode is disposed on the other surface Because
An anode contact portion that contacts the anode electrode;
A cathode contact portion that contacts the cathode electrode;
A molding part that defines a molding chamber for molding the resin part on the outer peripheral end of the laminate sandwiched between the anode contact part and the cathode contact part;
A resin material that is provided in the molding part and is injected into the molding chamber and flows from the outer edge side of the molding chamber to the outer peripheral end of the laminated body flows toward the gas diffusion layer of one of the anode electrode and the cathode electrode. A flow control unit for controlling the flow of the resin material;
A membrane electrode assembly manufacturing apparatus, comprising: The laminate is configured such that the cathode electrode fits within the outer shape of the anode electrode,
The flow control part is a protruding part that protrudes from the molding part on the cathode electrode side into the molding chamber.
The membrane electrode assembly manufacturing apparatus according to claim 1. The protrusion is formed such that the protrusion height increases from the outer edge side of the molding chamber toward the outer peripheral end of the laminate, and then the protrusion height decreases.
The membrane electrode assembly manufacturing apparatus according to claim 2. The protruding portion is arranged so that the maximum protruding height position is in the vicinity of the outer peripheral end portion of the anode electrode in the direction from the outer edge side of the molding chamber toward the outer peripheral end portion of the laminate.
The apparatus for manufacturing a membrane electrode assembly according to claim 2 or 3, In the molding part on the anode electrode side, a recess is formed at a position facing the protruding part.
The membrane electrode assembly manufacturing apparatus according to any one of claims 2 to 4, wherein: The recess is formed so as to be recessed according to the protrusion height of the protrusion.
The membrane electrode assembly manufacturing apparatus according to claim 5. The cathode contact portion forms a protruding contact surface that protrudes toward the anode electrode, and contacts the cathode electrode through the protruding contact surface.
The apparatus for manufacturing a membrane electrode assembly according to any one of claims 2 to 6, wherein:

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