JP5361553B2 - Jig for manufacturing membrane / electrode assemblies - Google Patents

Description

  The present invention relates to a jig for producing a membrane / electrode assembly in which an electrode is joined to a solid polymer electrolyte membrane, which is used in a polymer electrolyte fuel cell.

  As a constituent element of a polymer electrolyte fuel cell, there is a membrane-electrode assembly (MEA). Electrodes are bonded to both sides of the solid polymer electrolyte membrane to form an MEA. A pair of electrodes is disposed at a position sandwiching the electrolyte membrane, and these are pressurized and heated to form an MEA.

  Generally, the area of the solid polymer electrolyte membrane is larger than the area of the electrode. Therefore, the electrolyte membrane protrudes from the electrode and there is a so-called ear. For this reason, at the time of the pressurization and heating, wrinkles may occur in the ear portion due to the shrinkage of the electrolyte membrane. That is, when the electrode and the electrolyte membrane are joined, if the ear portion of the electrolyte membrane is free, wrinkles or waves of the electrolyte membrane tend to become large at the boundary with the portion facing the electrode, and the manufactured MEA It was sometimes difficult to build a stack. In addition, the wrinkles may cause gas leakage from the fuel cell.

  By pressing the ear part of the electrolyte membrane at the time of joining, wrinkles or undulations of the electrolyte membrane can be suppressed.

  In Patent Document 1, for the purpose of preventing the wrinkles, a solid polymer electrolyte membrane is formed by pressurizing and heating a cell in which a solid polymer electrolyte membrane larger than a pair of electrode membranes is sandwiched between electrode membranes. Of a polymer electrolyte fuel cell, in which at least a solid polymer electrolyte membrane protruding from the periphery of the electrode membrane of the cell is interposed between heat-resistant elastic members A method for producing a cell of a polymer electrolyte fuel cell, characterized in that it is sandwiched between heat-resistant elastic members (spacers) and heated and heated.

JP 2002-260684 A

  However, when the ear portion of the electrolyte membrane is pressurized using an elastic spacer, the spacer is deformed during the pressurization, and an unintended force may be applied to the electrolyte membrane or the electrode. Moreover, the pressure applied to the ears of the electrolyte membrane may be easily changed due to the uneven thickness of the electrodes and spacers. In addition, the spacer is likely to be deformed by repeated use, and the in-plane balance of how the pressure is applied to the electrolyte membrane may change gradually, and the method of applying pressure to the electrode and the electrolyte membrane may change gradually. . As a result, wrinkles at the ears of the electrolyte membrane may occur.

  An object of the present invention is to provide a jig for manufacturing a membrane / electrode assembly capable of preventing the generation of wrinkles even when an MEA is repeatedly manufactured.

  According to the present invention, the following jig for manufacturing a membrane / electrode assembly is provided.

1) A membrane for producing a membrane / electrode assembly for a polymer electrolyte fuel cell by joining a polymer electrolyte membrane and electrodes disposed on both sides of the polymer electrolyte membrane under pressure and heating. A jig for manufacturing an electrode assembly,
A guide and a recess for fixing the position of the electrode and the electrolyte membrane, and a mechanism for transferring heat and pressure to the electrode and the electrolyte membrane;
Provided with a plate made of a heat-resistant metal to press the electrolyte membrane outside the electrode in direct contact with the electrode separately,
The plate is supported from the body part with a spring,
A jig for manufacturing a membrane / electrode assembly, which has an inner circumferential spring and an outer circumferential spring as springs for supporting the plate .

2 )
The inner orbiting spring is located above or below the electrolyte membrane outside the electrode, the outer orbiting spring is located above or below the approximate outer edge of the plate,
Here, the substantially outer edge portion is a portion outside the portion of the plate that contacts the ear portion of the electrolyte membrane,
The ear portion of the electrolyte membrane is a portion protruding from the electrode of the electrolyte membrane.
1 ) The jig for producing a membrane / electrode assembly according to the above.

3 )
The jig for manufacturing a membrane / electrode assembly according to 1) or 2) , wherein the surface of the plate is subjected to corrosion resistance treatment.

  Even if the MEA is repeatedly manufactured according to the present invention, a jig for manufacturing a membrane / electrode assembly capable of preventing generation of wrinkles is provided.

It is a schematic diagram for demonstrating one form of the jig | tool for membrane / electrode assembly manufacture of this invention, (a) is a sectional side view, (b) is a top view. It is a schematic diagram for demonstrating arrangement | positioning of a solid polymer electrolyte membrane and an electrode at the time of manufacturing a membrane electrode assembly, (a) is a top view, (b) is a sectional side view. It is a typical sectional side view for demonstrating how to apply the force in the pressurization state of the jig | tool for membrane / electrode assembly manufacture of this invention. It is a typical sectional side view for demonstrating the state after joining of the jig | tool for membrane / electrode assembly manufacture of this invention.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings, but the present invention is not limited thereto.

  As shown in FIG. 1, the jig for manufacturing a membrane / electrode assembly is formed by pressurizing and heating a solid polymer electrolyte membrane 1a and electrodes 1b and 1c arranged on both sides of the solid polymer electrolyte membrane. Thus, the membrane / electrode assembly 1 for the polymer electrolyte fuel cell is manufactured. Note that the upper side of the drawing in FIG. 1 coincides with the upper vertical direction. The electrode 1c is placed and positioned in a hollow portion formed by a step between the main body portion 2 and the plate 3, and the electrolyte membrane 1b fits in the hollow of the frame-like plate 3 (portion in which the membrane presser 4 is housed). It is positioned at the penetrating portion of the film presser 4 that is frame-shaped. The membrane retainer 4 also serves as an electrode positioning guide simultaneously with the electrolyte membrane retainer.

  FIG. 2 schematically shows the arrangement of the electrolyte membrane 1a and the electrodes 1b and 1c when the membrane-electrode assembly is manufactured. The electrolyte membrane 1a is sandwiched between the two electrodes 1b and 1c, but has a larger area than the electrodes 1b and 1c and protrudes outward in the plane direction from the electrodes 1b and 1c. The protruding portion, that is, the electrolyte membrane 1a-a outside the electrode may be referred to as an electrolyte membrane ear or simply an ear in this specification.

  This apparatus includes a plate 3 made of a heat-resistant rigid body for pressurizing an electrolyte membrane (ear part) outside the electrode separately from the electrode. The plate 3 can be moved up and down independently of the main body portion 2. A membrane pressing member 4 is provided at a position facing the plate across the electrolyte membrane ear.

  Examples of the rigid body having relatively good thermal conductivity for use in the plate and the film pressing member include stainless steel. A plate and a film pressing member in which the surface of stainless steel is coated with a material having high heat resistance and corrosion resistance such as PTFE are preferable.

  Further, since it is desirable that the bonding temperature be uniform over the entire surface of the electrode, it is preferable that the thermal conductivity of the jig for manufacturing a membrane / electrode assembly is good. However, it is desirable to reduce the thickness of the plate 3 and the film presser 4 within a range where the strength is not lost, even in order to give good thermal conductivity in a place where strong pressure is applied, for example, in the range of 2 to 5 MPa. When using at a pressure of 0.2 mm to 5.0 mm, a member having a thickness of 0.2 to 5.0 mm may be used. It should be noted that the present invention is not limited to stainless steel, and a rigid body other than stainless steel may be used as long as attention is paid to strength and corrosion resistance treatment.

  Further, the plate 3 is supported from the main body portion 2 by a spring 5, and the spring is attached in a state where it can be expanded and contracted.

  The spring which supports the plate is arranged so as to go around twice. That is, an outer circumferential spring 5a and an inner circumferential spring 5b are provided.

  The inner circumferential spring 5b is located above or below (lower in FIG. 1) the electrolyte membrane (ear portion) outside the periphery of the electrode, and is arranged so that the plurality of springs 5b surround the electrode. The outer orbiting spring 5a is located above or below (lower in FIG. 1) the substantially outer edge of the plate 3, and a plurality of springs 5a are arranged so as to surround the inner orienting spring 5b. The substantially outer edge portion of the plate 3 here refers to a portion of the plate 3 that is outside the portion where the ear portion of the electrolyte membrane hits. By providing the substantially outer edge portion, the entire plate 3 can be given strength, and although not shown, the approximately outer edge portion provides a space for providing a screw or the like for connecting to the main body portion 2. This is because it is desirable that the portion of the electrolyte membrane corresponding to the ear is as flat as possible. Installation of screws and other parts may cause unevenness, so the installation part of screws and other parts should not be provided on the part where the electrolyte membrane is touched, but on the outer edge. Is preferred.

  The inner circumferential spring 5b pushes up the contact portion of the electrolyte membrane ear of the plate 3 when the electrode and the electrolyte membrane are joined, and presses the electrolyte membrane ear between the membrane presser 4 so that the electrolyte membrane ear is joined at the time of joining. Prevents the part from forming wrinkles. Furthermore, by pushing up the substantially outer edge portion of the plate 3 with the spring 5a, it is possible to alleviate in-plane variations in pressure due to distortion of the entire plate 3 due to deterioration over time and the like, and to apply pressure more uniformly as a whole.

  In a state where the electrode 1c, the electrolyte membrane 1b, the electrode 1a, and the membrane pressing member 4 are laminated on the main body portion 2, a pressing member 6 is disposed thereon. In the illustrated embodiment, the pressing member 6 has a downward convex shape, and the electrode surface is in contact with the protruding portion of the convex shape, but this protruding portion can be an individual component. Since the main body portion 2 and the pressing member 6 have a role of transmitting heat and pressure to the electrodes, thermal conductivity, strength, and surface accuracy are required. Therefore, it is desirable to use a metal.

  The surface of the plate is subjected to corrosion resistance treatment. This is effective in preventing metal ion invasion that may occur when the plate contacts the surface of the acidic electrolyte membrane. In addition, since metals such as iron are mixed into the membrane / electrode assembly, there are concerns about the effects of electrolyte membrane deterioration and ionic conduction inhibition. In order to avoid this, it is more desirable that the surface contacting the body portion 2 and the electrode of the pressing member 6 is also subjected to corrosion resistance treatment.

  With the above configuration, when joining the electrolyte membrane and the electrode, a force in a certain direction can be applied to the ear portion of the electrolyte membrane separately from the electrode.

  A rigid body that is not easily deformed is brought into contact with the electrolyte membrane ear, and the rigid body is supported by a double spring so that the pressure can be always applied perpendicularly to the electrolyte membrane surface. The inner spring is used to push the portion of the electrolyte membrane, and the outer spring has a structure in which pressure is more uniformly applied by alleviating in-plane variations in pressure due to distortion of the plate.

  FIG. 3 illustrates how force is applied when the electrolyte membrane and the electrode are pressurized and heated using the jig of the present invention. The pressure applied to the surfaces of the electrodes 1b and 1c is applied from the press, but the electrolyte membrane ear 1a-a is pressed by the plate 3 and the membrane pressing member 4 by the repulsive force when the spring is contracted. Even after the joining is completed (FIG. 4), the plate 3 is pushed up by the spring, and the plate 3, the electrolyte membrane ear 1a-a, and the membrane pressing member 4 are brought into close contact with each other, thereby suppressing the occurrence of wrinkles in the electrolyte membrane ear. . Since the repulsive force of the spring is determined by the spring constant of the spring itself and the amount of contraction (depending on the height of the space 7), the height of the spring and the space may be adjusted as necessary.

  Although the above has been described using the spring as an example, other mechanisms (actuators, piezo elements, etc.) may be used as a mechanism for reducing the distortion of the plate 3 at the time of joining.

  Since a rigid body with less sag is used to hold down the electrolyte membrane ear, the jig for manufacturing a membrane / electrode assembly is resistant to repeated use.

The jig for manufacturing a membrane / electrode assembly according to the illustrated embodiment is a solid polymer electrolyte membrane and a solid polymer electrolyte membrane and electrodes placed on both sides of the solid polymer electrolyte membrane are pressed and heated to join each other. A membrane / electrode assembly manufacturing jig for manufacturing a membrane / electrode assembly for a fuel cell,
A pair of plate-like members (pressurizing member 6 and main body 2) for sandwiching the solid polymer electrolyte membrane 1a and the electrodes 1b and 1c and pressurizing and heating them,
A pair of frame-like members (membrane presser 4 and plate 3; the cross section perpendicular to the longitudinal direction of the frame is a quadrangle) for sandwiching the ear portion of the solid polymer electrolyte membrane and pressurizing the ear portion.

  The film presser 4 is fixed to the pressurizing member 6. The plate 3 is fixed to the main body 2 via force adjusting means (spring).

  The plate 3 is disposed around the portion of the main body 2 that contacts the electrode 1c and adjacent to the portion of the main body 2 that contacts the electrode 1c. At the time of non-pressurization, an L-shaped section is formed by the side surface of the plate 3 and a surface that contacts the electrode of the main body 2, and the electrode 1c is positioned by the L-shaped section.

  The plate 3 has a notch, and the ear portion of the electrolyte membrane comes into contact with the upper surface of the notch. An L-shaped section is formed by the side surface of the notch and the upper surface of the notch, and the electrolyte membrane 1a is positioned by the L-shaped section.

  The membrane presser 4 is disposed around the portion of the pressing member 6 that contacts the electrode 1b and adjacent to the portion of the pressing member 6 that contacts the electrode 1b. An L-shaped section is formed by the side surface of the membrane presser 4 and the surface of the pressing member 6 that contacts the electrode 1b, and the electrolyte membrane 1b is positioned by the L-shaped section.

  Both the plate-like member (pressurizing member 6 and main body 2) and the frame-like member (membrane presser 4 and plate 3) can be formed of a metal such as stainless steel.

  In the description of the present invention, the description of the heating means for heating the jig for manufacturing the membrane / electrode assembly and the pressurizing means for pressing the jig for manufacturing the membrane / electrode assembly are omitted. In the production of the electrode assembly, it is possible to use an apparatus used for pressurizing and heating the electrolyte membrane and the electrode, such as a known hot press apparatus. For example, a membrane / electrode assembly can be manufactured by setting an electrolyte membrane and an electrode in a jig for manufacturing a membrane / electrode assembly, and heating and pressing the jig with a hot press apparatus.

DESCRIPTION OF SYMBOLS 1 Membrane / electrode assembly 1a Solid polymer electrolyte membrane 1b, 1c Electrode 2 Main body of jig for manufacturing membrane / electrode assembly 3 Plate (frame shape)
4 Membrane presser (frame shape)
5 Spring 5a Outer Spring 5b Inner Spring 6 Pressurizing Member 7 Space

Claims (3)

Membrane / electrode assembly for producing a membrane / electrode assembly for a polymer electrolyte fuel cell by joining a polymer electrolyte membrane and electrodes disposed on both sides of the polymer electrolyte membrane under pressure and heating A body manufacturing jig,
A guide and a recess for fixing the position of the electrode and the electrolyte membrane, and a mechanism for transferring heat and pressure to the electrode and the electrolyte membrane;
Provided with a plate made of a heat-resistant metal to press the electrolyte membrane outside the electrode in direct contact with the electrode separately,
The plate is supported from the body part with a spring,
A jig for manufacturing a membrane / electrode assembly, which has an inner circumferential spring and an outer circumferential spring as springs for supporting the plate . The inner orbiting spring is located above or below the electrolyte membrane outside the electrode, the outer orbiting spring is located above or below the approximate outer edge of the plate,
Here, the substantially outer edge portion is a portion outside the portion of the plate that contacts the ear portion of the electrolyte membrane,
The ears of the electrolyte membrane is a portion protruding from the electrode of the electrolyte membrane <br/> claim 1 membrane-electrode assembly manufacturing jig according. The jig for manufacturing a membrane / electrode assembly according to claim 1 or 2 , wherein the surface of the plate is subjected to corrosion resistance treatment.

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