JP2006196328A - Method and apparatus for manufacturing battery cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method for surely manufacturing a fuel battery cell while suppressing deformation of members in the manufacturing process. <P>SOLUTION: The fuel battery cell is equipped with a plate-like thin membrane electrode assembly 10, and a first metal plate 4 and a second metal plate 5 disposed on both sides of the thin membrane electrode assembly 10. The circumferential areas 4a, 5a of the first and second metal plates are sealed with an insulation layer interposed therebetween. The manufacturing method of the fuel battery cell comprises steps of: machining at least either of the first metal plate 4 and the second metal plate 5 into a warped shape such that the central area protrudes toward the direction of the membrane electrode assembly 10 than the circumferential area 4a, 5a; setting the second metal plate 5, and the membrane electrode assembly 10 on the first metal plate 4 in this order; and sealing the circumferential areas 4a, 5a of the first metal plate 4 and the second metal plate 5 with the insulation layer interposed therebetween. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention includes a plate-like thin film electrode composition, and a first metal plate and a second metal plate disposed on both sides of the thin film electrode composition, and the peripheral regions of the first and second metal plates are insulated. The present invention relates to a manufacturing method and manufacturing equipment of a battery cell sealed with a layer interposed therebetween.

  Polymer fuel cells that use solid polymer electrolytes such as polymer electrolytes have high energy conversion efficiency, are thin, small, and lightweight, and are therefore being actively developed for household cogeneration systems and automobiles . As a conventional structure of such a fuel cell, one shown in FIG. 17 is known (see, for example, Non-Patent Document 1).

  That is, as shown in FIG. 17, the anode 101 and the cathode 102 are disposed with the solid polymer electrolyte membrane 100 interposed therebetween. Further, the unit cell 105 is configured by being sandwiched by a pair of separators 104 via a gasket 103. Each separator 104 is formed with a gas flow path groove. A flow path for reducing gas (for example, hydrogen gas) is formed by contact with the anode 101, and an oxidizing gas (for example, for example, hydrogen gas) is contacted with the cathode 102. Oxygen gas) flow paths are formed. Each gas is supplied to the electrode reaction (chemical reaction at the electrode) by the action of the catalyst supported in the anode 101 or the cathode 102 while flowing through each flow path in the unit cell 105, and the generation of current and ions Conduction occurs.

  A large number of the unit cells 105 are stacked, and the unit cells 105 are electrically connected in series to constitute the fuel cell N, and the electrode 106 can be taken out from the unit cells 105 at both ends. Such a fuel cell N is attracting attention as a power source for electric vehicles and a distributed power source for home use in various applications because of its clean and high efficiency.

  On the other hand, with the recent activation of IT technology, mobile devices such as mobile phones, notebook computers, and digital cameras tend to be frequently used, but most of these power sources use lithium ion secondary batteries. However, as mobile devices become more sophisticated, power consumption has increased and clean and highly efficient fuel cells have been attracting attention as power sources.

  However, in the conventional structure as shown in FIG. 17, there is no degree of freedom in the structure, so there is a problem in that it is difficult to reduce the thickness and size and increase the degree of freedom of shape required as a power source for mobile devices, and the maintenance property is poor. There was also. In addition, it is difficult to supply the redox gas so as not to mix with each other in the fuel cell and to seal it, and it is difficult to reduce the size and weight of the fuel cell while satisfying these conditions. Met. In other words, conventionally, cell parts are mutually coupled with fastening parts of bolts and nuts, and a certain pressure is applied to the cell parts. Therefore, it is necessary to increase the rigidity of each member in order to ensure sealing performance. Thinning, miniaturization, weight reduction, and free shape design were difficult.

In view of such problems, the present inventors have invented a fuel battery cell (one example of a battery cell) that can cope with thinning, downsizing, etc., and have filed an application (for example, unpublished) Japanese Patent Application No. 2004-82882). The basic configuration of the fuel cell comprises a plate-like thin film electrode composition and a pair of metal plates (cathode side metal plate and anode side metal plate) disposed on both sides of the thin film electrode composition, The periphery of these metal plates is sealed with caulking with an insulating layer interposed therebetween. The thin film electrode composition is composed of a solid polymer electrolyte and a pair of electrode plates (anode side and cathode side) disposed on both sides thereof. Since the metal plate is sealed with caulking while being electrically insulated, the fuel cell can be reliably sealed without increasing the thickness while preventing short circuit between the two. As a result, maintenance is facilitated, and the rigidity of the cell member is not required as compared with the conventional structure shown in FIG. 7, so that each fuel cell can be significantly reduced in thickness. Furthermore, since a solid polymer electrolyte and a metal plate are used, a free planar shape and bending are possible, and a small, lightweight and free shape design is possible.
Nikkei Mechanical separate volume "Fuel Cell Development Frontline" Date of issue: June 29, 2001, Publisher: Nikkei BP, Chapter 3, PEFC, 3.1 Principles and Features p46

  Accordingly, the inventors of the present application have already provided a manufacturing method and manufacturing equipment for a fuel cell having such a configuration (for example, unpublished Japanese Patent Application No. 2004-270208). An object of the present invention is to further improve the manufacturing method and manufacturing equipment disclosed therein. In particular, when the thickness is reduced, the individual members constituting the fuel battery cell are formed in a flat plate shape, and thus are easily deformed. In particular, when the peripheral area is caulked and sealed, the central area easily deforms in the direction of protruding outward with the action of the pressing force on the peripheral area. If it does so, the contact state of a metal plate and a thin film electrode composition will worsen, and it may become impossible to take an electrical output efficiently. Therefore, a manufacturing method and manufacturing equipment that can reliably manufacture battery cells while suppressing deformation of members in the manufacturing process are required.

In order to solve the above problems, the battery cell manufacturing method according to the present invention includes:
A plate-shaped thin-film electrode composition, and a first metal plate and a second metal plate disposed on both sides of the thin-film electrode composition, and the peripheral regions of the first and second metal plates sandwich an insulating layer therebetween. In the manufacturing method of the battery cell sealed in the interposed state,
Processing at least one of the first metal plate and the second metal plate into a curved shape in which the central region protrudes in the direction of the thin film electrode composition from the peripheral region;
A step of setting the thin film electrode composition and the second metal plate in this order on the first metal plate;
And a step of sealing the peripheral regions of the first metal plate and the second metal plate with an insulating layer interposed therebetween.

  The operation and effect of the battery cell manufacturing method according to this configuration will be described by taking a fuel battery cell as an example. The manufactured battery cell includes a plate-like thin film electrode composition and first and second metal plates disposed on both sides thereof, and is formed into a plate-like thin shape as a whole. The gas channel can be formed on both sides of the thin film electrode composition by an appropriate method. The battery cell has a shape in which a thin film electrode composition is sandwiched between first and second metal plates, and its peripheral region is sealed with an insulating layer. The first and second metal plates are not simply planar, and at least one of the first and second metal plates is processed into a curved shape whose central region protrudes in the direction of the thin film electrode composition from the peripheral region. Accordingly, when the peripheral region is sealed, even if a force that causes the central region to protrude outwards is applied, the central region of the manufactured fuel cell is formed in advance because it has been processed into a curved shape inward. Finishing into a shape that bulges outward can be suppressed. Thereby, the contact state of a thin film electrode composition and a 1st, 2nd metal plate can be made favorable. As a result, the manufacturing method which can manufacture a battery cell reliably can be provided, suppressing a deformation | transformation of a member in a manufacturing process.

In the present invention, by further drawing the peripheral region of the first metal plate, further having a step of forming a standing bent portion around the entire peripheral region,
In the sealing step, it is preferable to perform a step of crimping and sealing the peripheral region by falling the entire circumference of the bent portion into the peripheral region of the second metal plate that is in the inner direction.

  As the sealing step, the peripheral area is caulked and sealed, so that the cell can be reliably sealed and fuel gas leakage or the like can be prevented. In order to perform caulking sealing, a standing bent portion is formed on the entire periphery of the peripheral area of the first metal plate. The thin film electrode composition and the first metal plate are placed in this order on the inside of the standing bent portion. And a peripheral area | region can be reliably sealed by falling a standing bending part in the peripheral area | region of the 2nd metal plate which is an inner side direction.

  In this invention, it is preferable that the clearance gap between the inner wall of the said standing bending part and the peripheral end surface of a 2nd metal plate is 0.05-0.15 mm.

  When caulking sealing is performed, if the clearance between the standing bent portion and the peripheral end surface of the second metal plate is less than 0.05 mm, the clearance is too narrow. Therefore, in the caulking sealing step, the standing bent portion and the peripheral end surface are There is a possibility that it will come into contact, and as a result, the force that the central area of the metal plate tries to protrude outwards will act greatly, but if it is 0.05 mm or more, such possibility is suppressed. can do. Further, if the clearance exceeds 0.15 mm, the possibility of gas leakage inside the cell increases. Therefore, it is preferable to set the clearance as described above.

  The protruding amount of the curved shape according to the present invention is preferably 0.05 to 0.15 mm. If it is less than 0.05 mm, it is difficult to exhibit the effect of suppressing the outward protrusion of the central region of the metal plate. If it exceeds 0.15 mm, there is a problem that the sealing pressure when performing caulking sealing becomes too large, and the force acting on the thin film electrode composition becomes too large. By setting the protrusion amount as described above, an appropriate sealing process can be achieved.

In order to solve the above problems, the battery cell manufacturing facility according to the present invention comprises:
A plate-shaped thin-film electrode composition, and a first metal plate and a second metal plate disposed on both sides of the thin-film electrode composition, and the peripheral regions of the first and second metal plates sandwich an insulating layer therebetween. In a battery cell manufacturing facility that is sealed in an interposed state,
A mold used in a step of processing at least one of the first metal plate and the second metal plate into a curved shape whose central region protrudes in the direction of the thin film electrode composition from the peripheral region;
The thin film electrode composition and the second metal plate are set in this order on the first metal plate, and the peripheral region of the first metal plate and the second metal plate is interposed between the insulating layers. It has a metal mold | die used for the process to seal.

  The operation and effect of the battery cell manufacturing facility having such a configuration is as described above, and it is possible to provide a manufacturing facility that can reliably manufacture the battery cell while suppressing deformation of members in the manufacturing process.

  DESCRIPTION OF EMBODIMENTS Preferred embodiments of a battery cell manufacturing method and manufacturing equipment according to the present invention will be described with reference to the drawings. First, the configuration of a fuel battery cell (an example of a battery cell) to be manufactured will be described. FIG. 1 is an assembled perspective view showing an example of the fuel battery cell of the present invention, and FIG. 2 is a longitudinal sectional view showing an example of the fuel battery cell of the present invention.

  As shown in FIGS. 1 and 2, the fuel cell of the present invention includes a plate-shaped solid polymer electrolyte 1, a cathode-side electrode 2 disposed on one side of the solid polymer electrolyte 1, and on the other side. The anode side electrode plate 3 is provided. In the present embodiment, a fuel flow channel 9 is formed in the anode side metal plate 5 by etching, and the peripheral region 5a of the anode side metal plate 5 and the peripheral region 4a of the cathode side metal plate 4 are etched away from other portions. An example in which the thickness is reduced is shown. By reducing the thickness of the peripheral regions 4a and 5a, it becomes easy to perform caulking. That is, the peripheral areas 4a and 5a correspond to areas where caulking is performed. For convenience of explanation, regions other than the peripheral regions 4a and 5a of the metal plates 4 and 5 are referred to as central regions 4b and 5b.

  The solid polymer electrolyte 1 may be any solid polymer membrane battery as long as it is used in conventional solid polymer membrane batteries. From the viewpoint of chemical stability and conductivity, a perfluorocarbon having a sulfonic acid group which is a super strong acid. A cation exchange membrane made of a polymer is preferably used. Nafion (registered trademark) is preferably used as such a cation exchange membrane. In addition, for example, a porous film made of a fluororesin such as polytetrafluoroethylene impregnated with the above Nafion or other ion conductive material, a porous film made of a polyolefin resin such as polyethylene or polypropylene, or a non-woven fabric. A material carrying Nafion or another ion conductive material may be used.

  The thinner the solid polymer electrolyte 1 is, the more effective it is to make the whole thinner. However, in consideration of ion conduction function, strength, handling property, etc., 10 to 300 μm can be used, but 25 to 50 μm is preferable. .

  The electrode plates 2 and 3 can function as a gas diffusion layer, and can supply and discharge fuel gas, oxidizing gas, and water vapor, and at the same time can exhibit a current collecting function. As the electrode plates 2 and 3, the same or different ones can be used, and it is preferable to support a catalyst having an electrode catalytic action on the base material. The catalyst is preferably supported at least on the inner surfaces 2 b and 3 b in contact with the solid polymer electrolyte 1.

  As the electrode base material, for example, conductive carbon materials such as carbon paper, fibrous carbon such as carbon fiber nonwoven fabric, and aggregates of conductive polymer fibers can be used. In general, the electrode plates 2 and 3 are prepared by adding a water-repellent substance such as a fluororesin to such a conductive porous material. When the catalyst is supported, a catalyst such as platinum fine particles and fluorine It is formed by mixing a water-repellent substance such as a resin, mixing it with a solvent to form a paste or ink, and then applying this to one side of an electrode substrate that should face the solid polymer electrolyte membrane. The

  In general, the electrode plates 2 and 3 and the solid polymer electrolyte 1 are designed according to the reducing gas and the oxidizing gas supplied to the fuel cell. In the present invention, it is preferable to use air as the oxidizing gas and hydrogen gas as the reducing gas. In addition, methanol, dimethyl ether, or the like can be used instead of the reducing gas.

  For example, when hydrogen gas and air are used, the cathode side electrode 2 on the side where the air is naturally supplied causes a reaction between oxygen and hydrogen ions, so that water is generated. Is preferred. In particular, under the operating conditions of low operating temperature, high current density, and high gas utilization rate, the electrode porous body is likely to be clogged (flooded) due to the condensation of water vapor, particularly at the air electrode where water is generated. Therefore, in order to obtain stable characteristics of the fuel cell over a long period of time, it is effective to ensure the water repellency of the electrode so that the flooding phenomenon does not occur.

  As the catalyst, at least one metal selected from platinum, palladium, ruthenium, rhodium, silver, nickel, iron, copper, cobalt and molybdenum, or an oxide thereof can be used. A supported one can also be used.

  The thickness of the electrode plates 2 and 3 is more effective for reducing the overall thickness as the thickness is reduced, but is preferably 50 to 500 μm in view of electrode reaction, strength, handling properties, and the like. The electrode plates 2 and 3 and the solid polymer electrolyte 1 may be laminated and integrated in advance by adhesion, fusion, or the like, or may simply be arranged in a stacked manner. Such a laminated body can also be obtained as the thin film electrode assembly 10 (Membrane Electrode Assembly: MEA), and may be used.

  A cathode side metal plate 4 is disposed on the surface of the cathode side electrode plate 2, and an anode side metal plate 5 is disposed on the surface of the anode side electrode plate 3. The anode side metal plate 5 is provided with a fuel inlet 5c and a discharge port 5d, and further, in the present embodiment, a flow channel 9 is provided in the anode side metal plate 5.

  The cathode-side metal plate 4 is provided with a number of openings 4c for supplying oxygen in the air. As long as the cathode side electrode plate 2 can be exposed, the number, shape, size, formation position, and the like of the opening 4c may be any. However, in consideration of the supply efficiency of oxygen in the air and the current collection effect from the cathode side electrode plate 2, the area of the opening 4c is preferably 10 to 50% of the area of the cathode side electrode plate 2, In particular, 20 to 40% is preferable. The opening 4c of the cathode side metal plate 4 may be provided with a plurality of circular holes, slits, or the like regularly or randomly, or may be provided with a metal mesh.

  As the metal plates 4 and 5, any metal can be used as long as it does not adversely affect the electrode reaction, and examples thereof include stainless steel plates, nickel, copper, and copper alloys. However, from the viewpoint of elongation, weight, elastic modulus, strength, corrosion resistance, press workability, etching workability and the like, a stainless steel plate, nickel and the like are preferable.

  The channel groove 9 provided in the anode side metal plate 5 may have any planar shape or cross-sectional shape as long as a channel for hydrogen gas or the like can be formed by contact with the electrode plate 3. In the present embodiment, the inlet 5 c and the outlet 5 d are connected by a single continuous channel groove 9, and the channel groove 9 is zigzag periodically folded back along the width direction of the metal plate 5. It is formed in a shape. In consideration of the flow path density, the stacking density at the time of fuel cell stacking, the flexibility, and the like, various forms of the flow path grooves 9 can be employed.

  A part of the channel groove 9 of the metal plate 5 may be formed on the outer surface of the electrode plate 3. As a method of forming the flow channel groove on the outer surface of the electrode plate 3, a mechanical method such as a hot press or cutting may be used. However, it is preferable to perform groove processing by laser irradiation in order to suitably perform fine processing. From the viewpoint of performing laser irradiation, the base material for the electrode plates 2 and 3 is preferably an aggregate of fibrous carbon.

  One or a plurality of inlets 5c and outlets 5d communicating with the channel groove 9 of the metal plate 5 can be formed. In addition, although the thickness of the metal plates 4 and 5 is more effective for reducing the overall thickness as the thickness is reduced, 0.1 to 1 mm is preferable in consideration of strength, elongation, weight, elastic modulus, handling property, and the like. Etching is preferable as a method of forming the flow channel 9 in the metal plate 5 in view of processing accuracy and ease. In the channel groove 9 by etching, a width of 0.1 to 10 mm and a depth of 0.05 to 1 mm are preferable. The cross-sectional shape of the channel groove 9 is preferably substantially square, substantially trapezoidal, substantially semicircular, V-shaped or the like.

  Etching is also preferably used for forming the opening 4c in the metal plate 4, thinning the peripheral regions 4a and 5a of the metal plates 4 and 5, and forming the inlet 5c and the outlet 5d in the metal plate 5. . Etching can be performed using, for example, a dry film resist or the like, after forming an etching resist having a predetermined shape on the metal surface, and then using an etching solution corresponding to the type of the metal plates 4 and 5. Moreover, the cross-sectional shape of the flow-path groove | channel 9 can be controlled more precisely by performing a selective etching for every metal using the laminated board of 2 or more types of metals.

  The embodiment shown in FIG. 2 is an example in which the caulking portions (peripheral regions 4a and 5a) of the metal plates 4 and 5 are thinned by etching. In this way, the caulking portion is etched to have an appropriate thickness, whereby sealing by caulking can be performed more easily. From this viewpoint, the thickness of the crimped portion is preferably 0.05 to 0.3 mm.

  In the present invention, the peripheral regions 4a and 5a of the metal plates 4 and 5 are sealed with caulking while being electrically insulated. Although electrical insulation can be performed using an insulating material, in the present embodiment, it can be performed by interposing the peripheral edge portion 1a of the solid polymer electrolyte 1.

  In the present invention, a structure in which the solid polymer electrolyte 1 is sandwiched between the peripheral regions 4a and 5a of the metal plates 4 and 5 as shown in FIG. That is, the solid polymer electrolyte 1 in the region outside the electrode plates 2 and 3 is held between the peripheral regions 4a and 5a. According to such a structure, inflow of gas or the like from one of the electrode plates 2 and 3 to the other can be effectively prevented.

  As the caulking structure, the structure shown in FIG. 2 is preferable from the viewpoint of sealing performance, ease of manufacture, thickness, and the like. That is, the peripheral region 4a of one cathode side metal plate 4 is made larger than the peripheral region 5a of the other anode side metal plate 5, and the peripheral region 4a of the cathode side metal plate 4 is interposed with the solid polymer electrolyte 1 interposed. A caulking structure is preferable in which the metal plate is folded so as to sandwich the peripheral region 5 a of the anode side metal plate 5. In this caulking structure, it is preferable to provide a step in the peripheral region 4a of the metal plate 4 by pressing or the like. A manufacturing facility for performing such a caulking structure will be described in detail later.

  When configuring a fuel cell, one or a plurality of fuel cells as shown in FIGS. 1 and 2 can be used, but the solid polymer electrolyte 1, a pair of electrode plates 2, 3, and a pair of metal plates It is also possible to form unit cells with 4 and 5 and to stack a plurality of unit cells or to arrange them on the same surface. By doing so, it is possible to provide a high-power fuel cell without the need to apply a certain pressure to the cell parts by mutually coupling with the fastening parts of the bolts and nuts.

  When used as a fuel cell, it is possible to join a fuel supply pipe directly to the fuel inlet 5c and outlet 5d of the metal plate 5, but in making the fuel cell thinner, It is preferable to provide a joint mechanism having a small thickness and a pipe parallel to the surface of the metal plate 5. For example, a metal pin for a joint can be attached to the metal plate 5 at the inlet 5c. This attachment can be performed by caulking or press fitting. A pipe can be press-fitted and attached to this pin.

  The metal plates 4 and 5 and the solid polymer electrolyte 1 which are members constituting the fuel battery cell are formed in a rectangular shape, but four corners thereof are formed in an R shape. By attaching R to the four corners, it is easy to perform the caulking sealing process described later.

<About manufacturing method and manufacturing equipment>
Next, the manufacturing method and manufacturing equipment of the fuel cell shown in FIGS. FIG. 3 is an external perspective view showing a mold that is a main part of the manufacturing facility. FIG. 4 is a conceptual diagram showing a cross-sectional configuration of the mold.

  The manufacturing facility includes a fixed unit 20 and a movable unit 30. The fixed side unit 20 includes a first lower mold 21 and a second lower mold 22 as molds. The first lower mold 21 is provided with a coil spring 23 as an urging mechanism, and acts to urge the first lower mold 21 upward. The first lower mold 21 presses the central region 4b of the cathode side metal plate 4 of the fuel cell. The second lower mold 22 is disposed so as to surround the first lower mold 21, and performs press working on the peripheral region 4 a of the metal plate 4. The second lower mold 22 is formed in a substantially rectangular annular shape in plan view. The second lower mold 22 includes a mechanism (corresponding to the first adjustment mechanism 24) that can be adjusted in the vertical direction. For example, the adjustment mechanism 24 can be configured by a mechanism using bolts and nuts. The first adjustment mechanism 24 can adjust the relative height relationship between the upper surface of the first lower mold 21 and the upper surface of the second lower mold 22. Specifically, the first lower mold 21 located in the central area is in a position recessed from the second lower mold 22 located in the peripheral area, and the protrusion amount h1 of the second lower mold 22 relative to the first lower mold 21 is set. Can be adjusted.

  The second lower mold 22 is formed with a hole 22a for inserting a guide shaft for guiding the second upper mold in the vertical direction. Moreover, as shown in FIG. 3, the hole for planting the two positioning pins 25 is also formed. The member to be processed can be positioned by the positioning pin 25. Positioning holes are formed in the member to be processed, and by inserting the holes into the positioning pins 25, the workpiece can be positioned during processing.

  The movable unit 30 includes a first upper mold 31 and a second upper mold 32 as molds. The second upper mold 32 is provided with a coil spring 33 as an urging mechanism, and acts to urge the second upper mold 32 downward. The first upper mold 31 presses the central region 5b of the anode side metal plate 5 of the fuel cell. The second upper mold 32 is disposed so as to surround the first upper mold 31, and presses the peripheral area 5 a of the metal plate 5. The second upper mold 32 is formed in a substantially rectangular annular shape in plan view. The second upper mold 32 includes a mechanism (corresponding to the second adjustment mechanism 34) that can be adjusted in the vertical direction. As the adjustment mechanism 34, it can be comprised by the mechanism using a volt | bolt nut, for example. The relative height relationship between the lower surface of the first upper mold 31 and the lower surface of the second upper mold 32 can be adjusted by the second adjustment mechanism 34. Specifically, the protrusion amount h2 of the second upper mold 32 relative to the first upper mold 31 can be adjusted. By providing the adjusting mechanisms 24 and 34 as described above, an appropriate pressing force can be applied in press working.

  The second upper mold 31 is formed with a hole 32a for inserting a guide shaft for guiding the second upper mold 31 in the vertical direction. A hole 32b into which the positioning pin 25 is inserted is also formed.

  As shown in FIG. 4, pressing can be performed by operating the operation unit 40. In other words, the movable unit 30 is moved downward by operating the operation unit 40. The contact portion 26 provided on the fixed side unit 20 side and the contact portion 36 provided on the movable side unit 30 side are in contact with each other, and the distance Y between them is the movement of the movable side unit 30. Corresponds to the stroke.

  As will be described later, the number of steps of press working using the manufacturing facility is roughly divided into eight steps (six steps in terms of machining). For the lower molds 21 and 22 and the upper molds 31 and 32, molds suitable for each process are used, but if there are those that can be used in common, they are used in common. Although the size and shape of the mold are different in each process, the basic configuration is as shown in FIG.

  In addition, although it is a kind of press work, a punching process, a drawing process, etc. are included, and it is not limited to a specific kind of process as this invention.

  FIG. 4 schematically shows the workpiece W as a subject of press working, but the form of the workpiece W differs depending on the press working process. For example, there may be a single member or a plurality of members may be set.

<Manufacturing process>
Next, a specific manufacturing process will be described. FIG. 5 is a process diagram showing the order of the manufacturing process. As a process before processing using the manufacturing equipment shown in FIGS. 3 and 4, the metal plates 4 and 5 are etched (S1). As shown in FIG. 6 (a), the anode-side metal plate 5 is formed by etching a metal plate having a constant thickness to reduce the thickness of the peripheral region 5a, and the channel groove 9, the inlet 5c, and the outlet 5d. Similarly, it is formed by etching. For example, a metal plate having a thickness of 0.3 mm is etched to form the peripheral region 5a with a thickness of 0.1 mm and a flow path groove 9 with a depth of about 0.2 mm.

  Similarly, as shown in FIG. 6 (b), the cathode-side metal plate 4 is also etched by etching a metal plate having a constant thickness to reduce the thickness of the peripheral region 4a. Form. For example, a metal plate having a thickness of 0.3 mm is etched, and the thickness of the peripheral region 4a is set to about 0.1 mm.

  After performing the pre-process as described above, processing using a manufacturing facility is performed. First, drawing of the cathode side metal plate 4 and drawing of the anode side metal plate 5 are performed (S2, S3). This drawing process is a process for forming a 150 μm step on the metal plates 4 and 5. FIGS. 7A and 7B show how each metal plate is drawn. By this drawing process, steps 4f and 5f are formed at locations near the boundaries between the peripheral areas 4a and 5a of the metal plates 4 and 5 and the central areas 4b and 5b. As a result, spaces 4g and 5g are formed inside the metal plates 4 and 5, respectively. The space portions 4g and 5g function as space portions for accommodating the electrode plates 2 and 3 of the thin film electrode composition 10. The metal plate 4 and the metal plate 5 are drawn separately.

  As the mold configuration for performing the drawing process, the shape shown in FIG. 4 can be used. Also, dies for drawing the cathode side metal plate 4 (first and second lower dies 21 and 22 and first and second upper dies 31 and 32) and drawing the anode side metal plate 5 are drawn. The same mold can be used as the mold. In FIG. 7, it is shown in accordance with the posture when assembled, but the posture (vertical direction) when actually set in the manufacturing facility is the posture of the metal plate 5 shown in FIG. Will be set.

  When performing the drawing process, when the second upper die 32 descends from above, the metal plates 4 and 5 are first brought into contact with the peripheral regions 4a and 5a. At that time, since the stoppers (contact portions 26 and 36) are not yet in contact with each other, the second upper mold 32 tries to further lower, but the second lower mold 22 is in a fixed state. Therefore, the spring 33 is compressed.

  On the other hand, the first upper mold 31 located in the central regions 4b and 5b is continuously lowered and stopped with the stopper coming into contact with the lower surface of the first upper mold 31 further lower than the lower surface of the second upper mold 32. To do. Thereby, drawing processing is performed on the metal plates 4 and 5 to form steps (space portions 4g and 5g). The step size at this time is, for example, about 0.15 mm, and the space portions 4g and 5g corresponding to the thickness of the electrode plates 2 and 3 to be accommodated are formed.

  Next, the metal plates 4 and 5 are punched (S4 and S5). The state of this punching process is shown in FIG. In the punching dimension L1 of the anode side metal plate 5 and the punching dimension L2 of the cathode side metal plate 4, L2 is larger, so that the mold used in the punching process is the anode side metal plate 5 and the cathode side. It differs from the metal plate 4. As will be described later, since the caulking cost is required for caulking and sealing the peripheral area 4a of the cathode side metal plate 4 in the caulking process, the dimensions are increased. The movement of the die in this punching is basically the same as the drawing in S2 and S3, although the amount of stroke Y is set differently.

  Next, the metal plates 4 and 5 are processed into a curved shape (a kind of drawing process) (S6, S7). The state of this curved shape processing is shown in FIG. By this processing, gently curved concave portions 4k and 5k are formed in the central region of the metal plates 4 and 5. The depth of the curved concave portions 4k and 5k is preferably about k1 = k2 = 0.05 to 0.15 mm (FIG. 9 is exaggerated). The protruding directions of the curved concave portions 4k and 5k are directed to the direction of the thin film electrode composition 10. Note that only the central region is formed in the recess, and the peripheral regions 4a and 5a remain in a horizontal state. The movement of the mold in this curved shape machining is basically the same as described in S2 and S3.

  Next, the outer side 90 ° drawing process of the cathode side metal plate 4 is performed (S8). The state of this drawing process is shown in FIG. 10A, and the shape of the drawn metal plate 4 is shown in FIG. In this drawing process, the entire circumference of the peripheral region 4a of the metal plate 4 is bent 90 °. The movement of the mold in this drawing process is basically the same as described in S2 and S3.

  Next, the metal plates 4 and 5 and the thin film electrode composition 10 are set (S9). This state is shown in FIG. A thin-film electrode composition 10 (in which the electrode plates 2 and 3 are assembled on both surfaces of the solid polymer electrolyte 1) is set in the metal plate 4 drawn by 90 °. The electrode plate 2 of the thin film electrode composition 10 is accommodated in the space portion 4 g of the metal plate 4, and the electrode plate 3 is accommodated in the space portion 5 g of the metal plate 5. A metal plate 5 is set on the top. The peripheral portion 1a of the solid polymer electrolyte 1 has a shape along the peripheral region 5a bent 90 °, and is similarly set to be bent 90 °. The peripheral portion 1a of the solid polymer electrolyte 1 is slightly protruded from the peripheral region 5a.

  The metal plates 4 and 5 have curved concave portions 4k and 5k, and the central portions of the curved concave portions 4k and 5k are in contact with the thin film electrode composition 10.

  After setting in this state, the cathode side metal plate 4 is subjected to a 45 ° drawing process (S10). The second upper mold 32 used at this time has an inclined surface 32c of 45 ° with respect to the horizontal plane as shown in FIG. By operating this inclined surface 32c, the peripheral region 5a bent at 90 ° is once drawn to 45 °. The state at this time is shown in FIG.

  By operating the operation unit 40, the first and second upper molds 31 and 32 descend. When the second lower mold 22 and the second upper mold 32 come into contact with each other, the peripheral area 5a is bent inward by 45 °. When the second upper mold 32 comes into contact with the second lower mold 22, the stoppers (contact parts 26, 36) are not yet in contact (see FIG. 4). The compression process of the coil spring 33 proceeds until the stopper comes into contact. On the other hand, the first upper die 31 is above the metal plate 5 of the fuel cell and is in contact with the metal plate 5 when the second upper die 32 and the second lower die 22 come into contact with each other. Absent. When the stopper comes into contact, the first upper mold 31 is not lowered any more and stops in the state shown in FIG.

  At this time, the central regions 4b and 5b of the metal plates 4 and 5 formed in the curved shape are pressed by the first lower mold 21 and the first upper mold 31 to deform the curved shape into a planar shape. In addition, when the peripheral regions 4a and 5a are caulked and sealed, the central regions 4b and 5b try to float up, and the contact state with the thin film electrode composition 10 is deteriorated. Therefore, even if the above-described force acts on the central regions 4b and 5b, the contact between the thin film electrode composition 10 and the metal plates 4 and 5 can be reliably maintained, and the electrical output can be efficiently taken out. be able to.

  In addition, it has been described that the dimensions k1 and k2 of the curved concave portions are preferably 0.05 to 0.15 mm. The reason is that if it is less than 0.05 mm, it is difficult to exert the effect of suppressing the protrusion to the outside of the central region of the metal plate. If it exceeds 0.15 mm, sealing when caulking sealing is performed. This is because there is a problem that the pressure becomes too large and the force acting on the thin film electrode composition 10 becomes too large. By setting the protruding amount as described above, appropriate caulking sealing can be performed.

  Furthermore, the gap dimension j (see FIG. 11) between the inner wall surface of the standing bent portion of the metal plate 4 and the end surface of the peripheral region 5a of the metal plate 5 is preferably 0.05 to 0.15 mm. The reason is that if the thickness is less than 0.05 mm, the clearance is too narrow, and the standing bent portion and the peripheral edge surface may come into contact in the caulking sealing process. Therefore, due to this, the force that the central region of the metal plate tends to protrude outwards may act greatly, but if it is 0.05 mm or more, such a possibility can be suppressed. Further, if the clearance exceeds 0.15 mm, the possibility of gas leakage inside the cell increases. Therefore, it is preferable to set the clearance as described above.

  In the pressed state, the vertical gap dimension Δh (see FIG. 12) between the upper surface of the second lower mold 22 and the first upper mold 31 is set to about 0.5 mm. Moreover, the thickness of the metal plates 4 and 5 is 0.3 mm. The thickness of the solid polymer electrolyte 1 is 0.025 mm. Therefore, the gap dimension Δh is substantially the same as the thickness of the fuel cell to be caulked and sealed. Thereby, the deformation of the member can be effectively regulated without applying an excessive force to the fuel cell.

  The setting of the angle of 45 ° is preferably 45 ° ± 5 °, more preferably 45 ° ± 1 °. If it exceeds 50 °, there is a possibility that the bent part will not fall down well when performing 0 ° drawing. For example, a phenomenon such as buckling may occur, and it may not be crushed well, the quality of the sealed state is lowered, and problems such as gas leakage occur. On the other hand, if the angle is smaller than 40 °, it is not preferable because the bent portion does not easily fall down when it is smaller than 40 ° at a time.

  After the 45 ° drawing process is performed as described above, the outer 0 ° drawing process of the cathode side metal plate 4 is performed (S11). Thereby, the crimping process is completed. The die used for the 0 ° external drawing is a different die from the 45 ° drawing, and the press surface 32d is formed in a horizontal plane as shown in FIG. The peripheral region 5a bent at 45 ° in the previous process is further pressed down and tilted inward. At this time, the peripheral edge 1a of the solid polymer electrolyte 1 is also brought down inside. As a result, the peripheral region 5a is bent 180 ° in a horizontal state. As a result, the peripheral regions 4a and 5a are sealed with caulking. In addition, the solid polymer electrolyte 1 is interposed as an insulating layer between the peripheral region 4a and the peripheral region 5a, and is sealed in a state in which a short circuit between the metal plates 4 and 5 is prevented.

  In the same manner as shown in FIG. 12, after the second lower mold 22 and the second upper mold 32 abut, the compression process of the coil spring 33 is continued until the stoppers (abutment portions 26 and 36) abut. Persisted. Further, the position of the lower surface of the first upper mold 31 is the same as that in FIG. In addition, there is a gap between the first lower mold 21 and the lower surface of the metal plate 4.

  In step S11, the caulking sealing is completed, but a ring pressing process is performed for further safety (S12). This processing is a step of pressing the crimping-sealed peripheral regions 4a and 5a slightly inside the region with a press, whereby the sealed state can be made more reliable. The state at this time is shown in FIG. Moreover, FIG.14 (b) shows the shape of the 1st lower mold | type 21 used. The first upper mold 31 has a similar mold shape. Each mold is provided with projections 21t and 31t formed in a ring shape. Using these projections 21t and 31t, as shown in FIG. 14A, the inner sides of the peripheral regions 4a and 5a are pressed in a ring shape. Thereby, crimping sealing can be ensured more. Thus, the fuel battery cell as shown in FIG. 2 is completed.

  In the above steps, the steps for performing caulking sealing are S9 to S12 in FIG. In particular, when the 90 ° standing bent portion formed in step S8 is tilted inward, it is not tilted at once, but once it is drawn to 45 °, it is drawn to 0 °. Caulking sealing is performed in stages. If this is done in one stage, there is no guarantee that the bent part will fall down well, and the sealing state will deteriorate. However, as described above, the drawing process is performed in two stages to ensure sealing. Can do.

  Further, in the present invention, when the fuel battery cell is manufactured, the metal plates 4 and 5 are processed to have a curved shape and then crimped and sealed. Therefore, the completed fuel battery cell has a good contact state between the metal plates 4 and 5 and the thin film electrode composition 10, and the electric output can be taken out efficiently.

<Example>
Next, it was experimentally confirmed how much output difference is present when the curved shape is processed and when it is not processed. The protruding dimension of the curved shape was 0.1 mm. FIG. 15A is a graph showing the relationship between the current density (mA / cm ² ) and the output density (mW / cm ² ), and it can be clearly seen that the output is larger when processed into a curved shape. FIG. 15B is a graph showing the relationship between the current density (mA / cm ² ) and the cell resistance (mΩ), and it can be seen that the output is larger when processed into a curved shape.

  FIG. 16 is a graph showing the degree of variation in cell thickness of manufactured fuel cells. The measurement was performed with a micrometer. There are a total of 35 measurement locations for each fuel cell, including 7 locations in the long side direction and 5 locations in the short side direction. Also from the graph, it can be seen that the variation is smaller when processed into a curved shape. As described above, it was confirmed experimentally that the present invention is excellent.

<Another embodiment>
The configuration of the fuel cell is not limited to the structure shown in FIGS. For example, the cathode side metal plate 4 has a shape having many openings 4 c for taking in air, but the cathode side metal plate 4 may be formed in the same shape as the anode side metal plate 5.

  In this embodiment, the step of forming the flow channel grooves and the step of reducing the thickness of the collecting region and the step of forming the inlet / outlet / opening are performed by etching, but these may also be performed by pressing.

  In the present embodiment, the configuration in which the solid polymer electrolyte 1 is interposed as an insulating layer is described. However, caulking sealing may be performed by separately using an insulating member. The thickness of the insulating material is preferably 0.1 mm or less from the viewpoint of thinning. In addition, further thinning is possible by coating an insulating material (for example, the thickness of an insulating material is also 1 micrometer is possible). As the insulating material, sheet-like resin, rubber, thermoplastic elastomer, ceramics and the like can be used, but resin, rubber, thermoplastic elastomer and the like are preferable for improving the sealing performance, and in particular, polypropylene, polyethylene, polyester, fluorine resin. Polyimide is preferred. The insulating material can be integrated with the metal plates 4 and 5 in advance by sticking or coating the periphery of the metal plates 4 and 5 directly or via an adhesive.

  In this embodiment, when shifting to the next press process, an example in which the molds are replaced in order has been described. However, a configuration that allows continuous press processes using a progressive mold may be employed.

  The case of a fuel cell has been described as an example of the battery cell, but the present invention can also be applied to a lithium battery, an air battery, and the like.

Assembly perspective view showing an example of the fuel battery cell of the present invention The longitudinal cross-sectional view which shows an example of the fuel battery cell of this invention External perspective view showing the configuration of the mold Conceptual diagram showing the cross-sectional structure of the mold Process chart showing processing steps Conceptual diagram showing the etching process Conceptual diagram showing drawing Conceptual diagram showing the punching process Conceptual diagram showing the process of curved shape machining Conceptual diagram showing the external 90 ° drawing of the cathode side metal plate Sectional drawing which shows the state which set the metal plate and the thin film electrode composition to the metal mold | die Conceptual drawing showing 45 ° drawing of the metal plate on the cathode side Conceptual diagram showing the 0 ° drawing of the cathode side metal plate Conceptual diagram showing ring presser processing Graph showing the relationship between current density and output density Graph showing the degree of variation in cell thickness of manufactured fuel cells The figure which shows the structure of the fuel cell which concerns on a prior art

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid polymer electrolyte 1a Peripheral part 2 Cathode side electrode plate 3 Anode side electrode plate 4 Cathode side metal plate 4a Peripheral region 4b Central region 5 Anode side metal plate 5a Peripheral region 5b Central region 10 Thin film electrode composition 20 Fixed side unit 21 First lower mold 22 Second lower mold 23 Coil spring 26 Contact part (stopper)
30 Movable unit 31 First upper mold 32 Second upper mold 33 Coil spring 36 Contact portion (stopper)

Claims (5)

A plate-shaped thin-film electrode composition, and a first metal plate and a second metal plate disposed on both sides of the thin-film electrode composition, and the peripheral regions of the first and second metal plates sandwich an insulating layer therebetween. In the manufacturing method of the battery cell sealed in the interposed state,
Processing at least one of the first metal plate and the second metal plate into a curved shape in which the central region protrudes in the direction of the thin film electrode composition from the peripheral region;
A step of setting the thin film electrode composition and the second metal plate in this order on the first metal plate;
And a step of sealing the peripheral regions of the first metal plate and the second metal plate with an insulating layer interposed therebetween. By further drawing the peripheral area of the first metal plate, further comprising a step of forming a standing bent portion around the entire peripheral area,
The said sealing process WHEREIN: The whole circumference | surroundings of the said standing bending part are fallen in the peripheral area | region of the 2nd metal plate which is an inner side direction, and the process of crimping sealing a peripheral area | region is performed. Battery cell manufacturing method.   3. The method for manufacturing a battery cell according to claim 1, wherein a clearance between an inner wall of the standing bent portion and a peripheral end surface of the second metal plate is 0.05 to 0.15 mm.   The method for manufacturing a battery cell according to any one of claims 1 to 3, wherein the protruding amount of the curved shape is 0.05 to 0.15 mm. A plate-shaped thin-film electrode composition, and a first metal plate and a second metal plate disposed on both sides of the thin-film electrode composition, and the peripheral regions of the first and second metal plates sandwich an insulating layer therebetween. In a battery cell manufacturing facility that is sealed in an interposed state,
A mold used in a step of processing at least one of the first metal plate and the second metal plate into a curved shape whose central region protrudes in the direction of the thin film electrode composition from the peripheral region;
The thin film electrode composition and the second metal plate are set in this order on the first metal plate, and the peripheral region of the first metal plate and the second metal plate is interposed between the insulating layers. A battery cell manufacturing facility comprising a mold used in a sealing step.

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