JP2009289676A - Fuel cell and method of manufacturing the same - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell of which structure and process for connecting unit cells become simple and in which reliability and durability of the connection part are excellent, and to provide a method of manufacturing the same. <P>SOLUTION: The fuel cell includes: a plurality of unit cells C which have a solid polymer electrolyte layer 1; a first electrode layer 2 and a second electrode layer 3 installed on both sides of the solid polymer electrolyte layer 1; and furthermore a first conductive layer 4 and a second conductive layer 5 each arranged at the outside of these electrode layers 2, 3; a connection part J which connects electrically the conductive layers 4, 5 of either of the unit cell C1 and the other unit cell C2; and a resin molding 6 which includes integrated these unit cells C and the connecting part J by an insert molding. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell in which a plurality of laminates constituting a unit cell of a fuel cell are integrated by a resin molded body and a manufacturing method thereof, and particularly useful as a fuel cell used for a mobile device (portable device) and the like. It is.

  With the development of IT in recent years, lithium-ion secondary batteries are used for most power sources of mobile devices such as mobile phones, notebook computers, and digital cameras. However, as these mobile devices become highly functional, power consumption tends to increase more and more, and attention is focused on clean and highly efficient fuel cells for power supply or charging.

  As such a small and lightweight fuel cell, for example, as in Patent Document 1 below, a plate-shaped solid polymer electrolyte, an anode-side electrode plate arranged on one side thereof, and a plate-like solid polymer electrolyte are arranged on the other side. A cathode-side electrode plate; an anode-side metal plate arranged outside the anode-side electrode plate; and a cathode-side metal plate arranged outside the cathode-side electrode plate. What has been sealed by caulking through is known. However, the sealing of the metal plate with caulking has a problem that the process is complicated and the thickness control of the caulking portion requires accuracy.

  Therefore, in order to simplify the sealing process, the following Patent Document 2 discloses a sealing material such as an epoxy resin in a fuel cell including a plate-like solid polymer electrolyte, an electrode plate, and a metal plate similar to the above. In this case, only the peripheral regions of the metal plates on both sides are sealed while interposing an insulating material.

  Patent Document 3 below includes a plate-shaped solid polymer electrolyte and electrode plates (catalyst layer + conductive porous body) provided on both sides thereof, and a resin frame in which the periphery of each layer is insert-molded. An integrated fuel cell has been proposed. Further, for the purpose of improving the output voltage, there is disclosed a method in which a plurality of unit cells are simultaneously insert-molded and then unit cells are connected in series with a conductive clip or the like.

Japanese Patent Laid-Open No. 2005-150008 Utility Model Registration No. 3115434 JP 2005-11624 A

  However, in the fuel cell of Patent Document 2, when a plurality of unit cells are used for the purpose of improving the output voltage, it is necessary to seal the periphery of the metal plate for each unit cell, and the manufacturing process becomes complicated. It was. Further, after each unit cell is manufactured, it is necessary to electrically connect them, and there is a problem that the manufacturing process becomes complicated and the entire structure becomes complicated.

  On the other hand, in the cell member for a fuel cell of Patent Document 3, since a plurality of unit cells are simultaneously insert-molded, a simpler manufacturing method is provided, but the connection between the unit cells is a conductive clip provided after the molding, etc. Therefore, the structure and manufacturing process for connection are complicated, and there are problems such as reliability and durability of the connection part.

  SUMMARY OF THE INVENTION An object of the present invention is to provide a fuel cell having a simple structure and process for connecting unit cells, and having good connection part reliability and durability, and a method for manufacturing the same.

The above object can be achieved by the present invention as follows.
That is, the fuel cell of the present invention includes a solid polymer electrolyte layer, first and second electrode layers provided on both sides of the solid polymer electrolyte layer, and first electrodes disposed on the outer sides of these electrode layers. A plurality of unit cells having one conductive layer and a second conductive layer, a connection part for electrically connecting the conductive layers of any unit cell and another unit cell, and inserting the unit cell and the connection part And a resin molded body integrated by molding.

  According to the fuel cell of the present invention, the unit cells are electrically connected to each other through the connecting portion and integrated with the resin molded body by insert molding, so the structure and process for connecting the unit cells are simplified. Thus, a fuel cell with good reliability and durability of the connecting portion is obtained. In addition, since each layer is integrated with a resin molded body in which insert molding is performed, the conductive layer is held by the resin molded body and the contact pressure with the electrode layer can be increased, and the contact resistance is reduced and the battery output is improved. be able to. That is, a fuel cell with a high battery output can be obtained while having a simple structure in which each layer is insert-molded. When insert molding is performed, the first conductive layer and the second conductive layer are pressed from both sides by the injection pressure of the resin, but the conductive layer is separately pressed by a convex portion provided on the inner surface of the mold. The contact pressure between the electrode layer and the electrode layer can be further increased. During power generation, for example, fuel and oxygen are supplied to the first electrode layer and the second electrode layer through an opening or a channel provided in the resin molded body, so that the reaction at each electrode and the solid state are supplied. Electric power can be generated by ionic conduction in the polymer electrolyte.

  In the above, it is preferable that one first conductive layer, the other second conductive layer, and the connection portion of the adjacent unit cells are formed of a metal layer made of a continuous metal plate. By using such a metal plate, it is not necessary to connect the conductive layers separately, the structure and process for connecting the unit cells become simpler, and the reliability and durability of the connection part are better. It becomes. In addition, since a metal plate is used, a larger current can be taken out than other materials.

  The first conductive layer includes a first metal layer having an exposed portion that partially exposes the first electrode layer, and the second conductive layer is exposed to partially expose the second electrode layer. It is preferable to consist of a 2nd metal layer which has a part. As the conductive layer, those having gas permeability can be used, but by having the exposed portion, gas or liquid can be supplied to the electrode layer through the exposed portion. In addition, by using a metal layer, it is possible to extract a large current compared to other materials.

  In that case, it is preferable that the said resin molding has an opening provided in the position corresponding to the exposed part of the said 1st metal layer or the 2nd metal layer. According to this configuration, since the opening of the resin molded body is provided at a position corresponding to the exposed portion of the metal layer, a gas or liquid such as fuel or air is supplied to the electrode layer through the opening and the exposed portion. Power generation can be performed more efficiently.

  On the other hand, the method for producing a fuel cell of the present invention comprises a solid polymer electrolyte layer, first and second electrode layers disposed on both sides thereof, and a first conductive layer and a second conductive layer disposed on the outside thereof. Arranging a plurality of laminates including layers in a molding die in a state in which conductive layers of any laminate and other laminates are electrically connected to each other by a connecting portion; and a resin in the molding die And a step of forming a resin molded body that integrates the laminate and the connecting portion by injection.

  According to the method for manufacturing a fuel cell of the present invention, the conductive layers of the laminate constituting the unit cell are electrically connected by the connecting portion and integrated with the resin molded body by insert molding. The structure and process for connection are simplified, and a fuel cell with good connection part reliability and durability can be manufactured. In addition, since each layer is integrated with a resin molded body that is insert-molded, the conductive layer is held by the resin molded body, so that the contact pressure with the electrode layer can be increased, and the contact resistance is reduced and the battery output is improved. Can do. That is, it is possible to obtain a fuel cell having a high battery output while having a simple structure and manufacturing method in which insert molding is performed using each layer.

  In the above, it is preferable that one first conductive layer, the other second conductive layer, and the connection portion of the adjacent laminates are formed of a metal layer made of a continuous metal plate. By using such a metal plate, it is not necessary to connect the conductive layers separately, the structure and process for connecting the unit cells become simpler, and the reliability and durability of the connection part are better. It becomes. In addition, since a metal plate is used, a larger current can be taken out than other materials.

  The first conductive layer includes a first metal layer having an exposed portion that partially exposes the first electrode layer, and the second conductive layer is exposed to partially expose the second electrode layer. It is preferable to consist of a 2nd metal layer which has a part. As the conductive layer, those having gas permeability can be used, but by having the exposed portion, gas or liquid can be supplied to the electrode layer through the exposed portion. In addition, by using a metal layer, it is possible to extract a large current compared to other materials.

  In that case, it is preferable that the said resin molding has an opening provided in the position corresponding to the exposed part of the said 1st metal layer or the 2nd metal layer. According to this configuration, since the opening of the resin molded body is provided at a position corresponding to the exposed portion of the metal layer, a gas or liquid such as fuel or air is supplied to the electrode layer through the opening and the exposed portion. Power generation can be performed more efficiently.

  A preferred embodiment of a fuel cell according to the present invention will be described with reference to the drawings. 1A and 1B are diagrams showing an example of a fuel cell according to the present invention, where FIG. 1A is a top view, FIG. 1B is a cross-sectional view taken along line II, and FIG. 1C is a cross-sectional view taken along line II-II. is there.

  As shown in FIG. 1, the fuel cell of the present invention includes a plurality of unit cells C, and electrically connects the conductive layers of any one unit cell C1 and another unit cell C2 through a connecting portion. . In the present embodiment, an example in which the first conductive layer (first metal layer 4) of the unit cell C1 and the second conductive layer (second metal layer 5) of the unit cell C2 are electrically connected (in series connection). As shown, in the present invention, the conductive layers of any unit cell C1 and another unit cell C2 can be connected in parallel. In that case, the first conductive layers and the second conductive layers of any unit cell C1 and the other unit cell C2 are electrically connected. Of course, it is also possible to combine parallel connection and series connection.

  The number of unit cells C to be connected can be set according to a required voltage or current. In the present embodiment, an example in which two unit cells C are connected is shown.

  Each unit cell C in the present invention includes a solid polymer electrolyte layer 1, a first electrode layer 2 and a second electrode layer 3 provided on both sides of the solid polymer electrolyte layer 1, and these electrode layers 2, 3 The first conductive layer and the second conductive layer are disposed on the outer side of the first and second conductive layers, respectively. In the present embodiment, the first conductive layer and the second conductive layer are formed from the first metal layer 4 and the second metal layer 5 having exposed portions that partially expose the first electrode layer 2 and the second electrode layer 3. An example will be shown.

  Examples of the material for the conductive layer include metals, conductive polymers, conductive rubbers, conductive fibers, conductive pastes, and conductive paints.

  The solid polymer electrolyte layer 1 may be any solid polymer membrane type fuel cell as long as it is used, but from the viewpoint of chemical stability and conductivity, a sulfonic acid group that is a super strong acid is used. A cation exchange membrane made of a perfluorocarbon 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 layer 1 is, the more effective it is to make the whole thinner. However, considering the ion conduction function, strength, handling property, etc., 10 to 300 μm can be used, but 25 to 50 μm. preferable.

  The electrode layers 2 and 3 may be any as long as they cause an electrode reaction on the anode side and the cathode side near the surface of the solid polymer electrolyte layer 1. Among them, the one that exhibits the function as a gas diffusion layer to supply and discharge the fuel gas, the fuel liquid, the oxidizing gas, and the water vapor and at the same time exhibits the current collecting function can be preferably used. As the electrode layers 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 surface side in contact with the solid polymer electrolyte layer 1.

  As the electrode substrate of the electrode layers 2 and 3, for example, conductive carbon such as carbon paper, fibrous carbon such as carbon fiber nonwoven fabric, and an aggregate of conductive polymer fibers can be used. It is also possible to use the electrode layers 2 and 3 that are attached to the solid polymer electrolyte layer 1 by directly attaching the catalyst to the solid polymer electrolyte layer 1 or supporting the catalyst on conductive particles such as carbon black.

  In general, the electrode layers 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 layers 2 and 3 and the solid polymer electrolyte layer 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. It is also possible to use a fuel liquid such as methanol instead of the reducing gas.

  For example, when hydrogen gas and air are used, the second electrode layer 3 on the cathode side on which air is naturally supplied (in this specification, the anode side is assumed to be the first electrode layer and the cathode side is assumed to be the second electrode layer). In this case, since a reaction between oxygen and hydrogen ions occurs and water is generated, it is preferable to design according to the electrode reaction. 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 layers 2 and 3 is more effective for reducing the overall thickness as the thickness is reduced. However, in consideration of electrode reaction, strength, handling property, etc., 1 to 500 μm is preferable, and 100 to 300 μm is more preferable. The electrode layers 2 and 3 and the solid polymer electrolyte layer 1 may be laminated and integrated in advance by adhesion, fusion, coating formation, or the like, or may simply be arranged in a stacked manner. Such a laminated body can also be obtained as a membrane / electrode assembly (MEA), and may be used.

  In the present invention, the outer shape of the first electrode layer 2 and the second electrode layer 3 may be smaller than the outer shape of the solid polymer electrolyte layer 1, but the outer shape of the first electrode layer 2 and the second electrode layer 3 and the solid polymer. It is preferable that the outer shape of the electrolyte layer 1 is the same. If the outer shape of the electrode layer is the same as the outer shape of the solid polymer electrolyte layer, the laminate of the electrode plate and the solid polymer electrolyte can be punched out to produce a solid polymer electrolyte / electrode / joint. The cost of the joined body can be reduced by the effect. Moreover, the outer periphery of a metal layer is formed inside from the outer periphery of an electrode layer, Therefore The outer periphery of an electrode layer and the outer periphery of a solid polymer electrolyte layer can be sealed more reliably.

  A first metal layer 4 on the anode side is disposed on the surface of the anode side electrode layer 2, and a second metal layer 5 on the cathode side is disposed on the surface of the cathode side electrode layer 3 (in this specification, the anode side Is the first metal layer and the cathode side is the second metal layer). The first metal layer 4 has an exposed portion that partially exposes the first electrode layer 2. In the present embodiment, the anode side metal layer 4 is provided with an opening 4 a for supplying fuel gas or the like. An example is shown.

  The exposed portion of the first metal layer 4 may be any number, shape, size, formation position, etc. as long as the anode-side electrode layer 2 can be exposed. The opening 4a of the anode-side metal layer 4 is, for example, provided with a plurality of circular holes, slits, or the like regularly or randomly, or provided with the openings 4a by a metal mesh, or the first metal layer 4 as a comb electrode. The anode side electrode layer 2 may be exposed in any shape. The ratio (opening ratio) at which the area of the opening 4a is tightened is preferably 10 to 50%, more preferably 15 to 30%, from the viewpoint of the balance between the contact area with the electrode and the gas supply area.

  Further, the second metal layer 5 on the cathode side has an exposed portion that partially exposes the second electrode layer 3. In this embodiment, oxygen in the air is supplied to the cathode side metal layer 5 (naturally An example in which a large number of openings 5a for intake) is provided is shown. As long as the cathode-side electrode layer 3 can be exposed, the number, shape, size, formation position, and the like of the openings 5a may be any. The opening 5a of the cathode-side metal layer 5 is provided with, for example, a plurality of circular holes or slits regularly or randomly, or the openings 5a are formed by a metal mesh, and the second metal layer 5 is like a comb-shaped electrode. The cathode side electrode layer 3 may be exposed in any shape. From the viewpoint of the balance between the contact area with the electrode and the supply area of the gas, the ratio of the area of the opening 5a portion (opening ratio) is preferably 10 to 50%, and more preferably 15 to 30%.

  As the metal layers 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, copper, a copper alloy, a stainless steel plate, and the like are preferable from the viewpoints of conductivity, cost, shape imparting property, strength for pressurization, and the like. Moreover, what gave metal plating, such as gold plating, to said metal may be used.

  In addition, although the thickness of the metal layers 4 and 5 is effective in reducing the overall thickness as the thickness is reduced, considering conductivity, cost, weight, shape imparting property, strength for pressurization, etc., the thickness is 10 to 1000 μm. Preferably, 50-200 micrometers is more preferable.

  In the present invention, from the viewpoint of satisfactorily integrating the electrode layers 2 and 3 and the metal layers 4 and 5 with a resin, the outer periphery of the first metal layer 4 is formed on the inner side of the outer periphery of the first electrode layer 2. It is preferable that the outer periphery of the second metal layer 5 is formed on the inner side of the outer periphery of the second electrode layer 3. The outer periphery of the first metal layer 4 may be formed outside the outer periphery of the first electrode layer 2, and the outer periphery of the second metal layer 5 may be formed outward from the outer periphery of the second electrode layer 3. May be.

  When at least a part of the metal layer 4 and the metal layer 5 is exposed from the resin, electricity can be taken out using the part as an electrode. For this reason, although the terminal part which exposed the metal layer 4 and the metal layer 5 partially may be provided with respect to the resin molding 6, in this invention, in the case of series connection, the unit cell C of the both ends is provided. It is preferable that the metal layer 4 or the metal layer 5 is provided with projecting portions 4b and 5b serving as the electrodes of the unit cell C, and these protrude from the resin molded body 6 to the outside. The protrusions 4b and 5b can also be used for holding the metal layers 4 and 5 (laminate L) in the mold when performing insert molding.

  The formation of the metal layer 4 and the metal layer 5 and the formation of the openings 5a and 4a can be performed using press work (press punching process). In addition, the protrusions 4b and 5b of the metal layer 4 and the metal layer 5 may be provided with through holes in the insert-molded portions for the purpose of improving the flow and adhesion of the resin. Furthermore, in order to perform connection and fixation satisfactorily, through holes may be provided in the exposed portions of the protrusions 4b and 5b.

  As shown in FIG. 1, the fuel cell of the present invention includes a connection portion J that electrically connects the conductive layers of any unit cell C and other unit cells C. The first conductive layer of any unit cell C and the second conductive layer of another unit cell C are electrically connected. In the present embodiment, one first conductive layer (metal layer 4), the other second conductive layer (metal layer 5), and the connecting portion J of the adjacent unit cells C are made of a continuous metal plate. An example of a metal layer is shown.

  In this embodiment, the connecting portion J has a rectangular shape having a step portion at the center, but the connecting portion J may have any shape, or may partially protrude to the outside of the resin molded body 6. As will be described later, when the insert is formed, it is necessary to fix the position of the laminate in the mold, and when the position is fixed, the connecting portion J partially protrudes outside the resin molded body 6. Preferably there is.

  The connecting portion J connects adjacent unit cells C in series, and is a metal plate integrated with the first metal layer 4 and the second metal layer 5. Instead of disposing the first metal layer 4 and the second metal layer 5 independently, by using this metal plate, the fuel cell in which the unit cells C are connected in series simply by disposing the metal plate in the mold. Can be manufactured.

  As shown in FIG. 1C, the metal plate includes a first metal layer 4 and a second metal layer 5 which are arranged adjacent to each other in a plane parallel to each other and extend outward in the same plane. , And integrated by a stepped portion. Such a stepped portion can be produced by subjecting a metal plate to sheet metal processing.

  As shown in FIG. 1, the fuel cell of the present invention includes a resin molded body 6 in which the unit cell C and the connecting portion J as described above are integrated by insert molding. The resin molded body 6 preferably has a supply part for supplying gas or liquid to the first electrode layer 2 and the second electrode layer 3, and this supply part is the first metal layer 4 or the second metal layer 5. The opening 6a is preferably provided at a position corresponding to the exposed portion.

  In the present embodiment, resin molding is performed in a state where the first metal layer 4 and the second metal layer 5 are pressed from both sides so that the first electrode layer 2 and the second electrode layer 3 are exposed from the opening 6a. An example in which the body 6 is insert-molded and integrated is shown.

  In the present invention, the size of the openings 4a and 5a corresponding to the exposed portions of the metal layers 4 and 5 may be larger, the same size, or smaller than the size of the opening 6a of the resin molded body 6. Also good. However, the resin molded body 6 is preferably molded so that the size of the exposed portion of the first metal layer 4 and / or the second metal layer 5 is substantially equal to the size of the opening 6a. Specifically, the area of each opening 6a is preferably 60 to 150%, more preferably 80 to 130% of the area of each exposed portion.

  In the present embodiment, an example in which the size of the openings 4a and 5a corresponding to the exposed portions of the metal layers 4 and 5 is smaller than the size of the opening 6a of the resin molded body 6 is shown. Thereby, it is possible to pressurize the periphery of the openings 4a and 5a of the metal layers 4 and 5 at the time of molding using a portion corresponding to the opening 6a of the resin molded body 6 (see FIG. 2C). ).

  Examples of the material of the resin molded body 6 include a thermosetting resin, a thermoplastic resin, and a heat resistant resin, and a thermoplastic resin and a thermosetting resin are preferable. Examples of the thermoplastic resin include polycarbonate resin, ABS resin, liquid crystal polymer, polypropylene, polystyrene, acrylic resin, fluororesin, polyester, and polyamide. Examples of the thermosetting resin include epoxy resins, unsaturated polyester resins, phenol resins, amino resins, polyurethane resins, silicone resins, and thermosetting polyimide resins. Among these, polyester, polypropylene, and acrylic resin are preferable from the viewpoint of fluidity, strength, melting temperature, and the like of the resin in the mold, and these can be selected depending on the application.

  As the resin molded body 6, it is also possible to use a resin elastomer such as a thermoplastic elastomer or rubber. In that case, it is possible to make the whole fuel cell flexible by using another material having flexibility.

  The overall thickness of the resin molded body 6 is preferably 0.3 to 4 mm, and more preferably 0.5 to 2 mm, from the viewpoints of the strength of integration with the resin, the pressure for pressing the metal layer, and the thinning. In particular, the thickness of the resin molded body 6 at the portion covering the metal layer is preferably 0.2 to 1.5 mm, and more preferably 0.3 to 1.0 mm, from the viewpoint of pressure to pressurize the metal layer.

  The area of the outer shape of the resin molded body 6 is preferably 101 to 200% of the outer area of the solid polymer electrolyte layer 1 from the viewpoint of the strength of integration by the resin and the pressure to pressurize the metal layer, and is preferably 150 to 180. % Is more preferable.

  The fuel cell of the present invention can generate power by supplying fuel or the like as follows. For example, the cathode side is left open to the atmosphere as it is, and power is generated by supplying fuel such as hydrogen gas to the space provided on the anode side or generating fuel such as hydrogen gas in the space provided on the anode side. be able to. It is also possible to attach a flow path forming member for forming a flow path to the anode side and / or the cathode side and supply an oxygen-containing gas or fuel to the flow path. As the flow path forming member, for example, a plate-like body provided with a flow path groove, a supply port, and a discharge port, or a structure similar to a separator of a stack type fuel cell can be used. When the latter is used, a stack type fuel cell can be constructed.

  The fuel cell as described above can be manufactured, for example, by the manufacturing method of the present invention. That is, the method of manufacturing a fuel cell according to the present invention includes a solid polymer electrolyte layer 1, a first electrode layer 2 and a second electrode layer 3 disposed on both sides thereof, as shown in FIGS. In addition, a plurality of the laminates L including the first conductive layer and the second conductive layer disposed outside them are electrically connected to each other by the connection portion J. Including a step of placing the molding die 10 in a state of being connected to the molding die 10. In the case of series connection, one first conductive layer of the adjacent laminate L is connected to the other second conductive layer, and in the case of parallel connection, one first conductive layer of the adjacent laminate L and the other second conductive layer are connected. One conductive layer is connected, and one second conductive layer and the other second conductive layer are connected.

  In this embodiment, the first metal layer 4 having exposed portions (for example, openings 4a and 5a) in which the first conductive layer and the second conductive layer partially expose the first electrode layer 2 and the second electrode layer 3, and An example is shown in which the second metal layer 5 is disposed in the mold 10 in a state where the exposed portion is closed by the convex portions 11 a and 12 a of the mold 10.

  A plurality of the laminates L constituting the unit cell C may be arranged side by side in the same plane, L-shaped two sides, square or rectangular two to four sides, triangular two to three sides It may be arranged on each side. In the present embodiment, an example in which two laminates L are arranged in the same plane is shown.

  In addition, the method for manufacturing a fuel cell according to the present invention includes a step of molding a resin molded body 6 that integrates the laminate L and the connection portion J by injecting a resin into the mold 10. In this embodiment, the first metal layer 4 and the second metal layer 5 are pressurized from both sides, and a resin is injected into the mold 10 so that the first electrode layer 2 and the second electrode layer 3 are injected. An example including a step of forming a resin molded body 6 having a supply portion for supplying gas or liquid and integrating the laminate L will be described. That is, an example in which almost all of the laminate L is covered with the resin molded body 6 except for the opening 6a corresponding to the supply unit.

  First, as shown in FIG. 2A, for example, a lower mold 11 having a convex portion 11a is prepared on the bottom surface of each unit cell C formation region. In the present embodiment, the projections 11 a and 12 a are provided on the inner surface of the mold member divided into the molding die 10 and the projections 11 a and 12 a are pressed against the first metal layer 4 and the second metal layer 5. An example is shown. The convex portion 11a has an upper surface large enough to close the opening 4a of the first metal layer 4 on the lower side of the laminate L, and is provided at a position facing each opening 4a. The lower mold 11 has a side wall around the bottom surface, and the upper mold 12 can be inserted along the inner surface of the side wall.

  The lower mold 11 (or the upper mold 12) is provided with a resin injection port 11b, but a plurality of injection ports 11b may be provided. Moreover, in order to improve the flow of the resin at the time of molding, one or more small resin outlets may be provided.

  Further, in order to expose the protruding portions 4b and 5b of the first metal layer 4 and the second metal layer 5 from the resin molded body 6 after molding, the side wall of the lower mold 11 has a divided structure (not shown). . When the laminate L is placed in the mold 10, the protrusions 4 b and 5 b of the first metal layer 4 and the second metal layer 5 are positioned in the rectangular notch provided on the side wall of the lower mold 11. The projecting portions 4b and 5b are structured to be pressed by the mold member. Thereby, protrusion part 4b, 5b can be exposed from the resin molding 6. FIG.

  Next, for example, as shown in FIG. 2B, a plurality of laminates L are arranged on the bottom surface of the lower mold 11. In that case, the upper surface of the convex part 11a formed in the bottom face of the formation area of each unit cell C arrange | positions in the position which can block | close the opening 4a of the 1st metal layer 4 of each laminated body L. FIG.

  In this invention, it arrange | positions in the shaping | molding die 10 in the state which electrically connected one 1st conductive layer and the other 2nd conductive layer of the adjacent laminated body L by the connection part J. FIG. In the present embodiment, one of the first conductive layers (metal layer 4), the other second conductive layer (metal layer 5) of the adjacent laminate L, and the connection portion J are formed of a continuous metal plate. An example in which layers are formed is shown.

  When arranging the laminate L, some or all of each layer may be integrated or may not be integrated. Moreover, when a part is not integrated, each layer may be arrange | positioned separately or may be arrange | positioned simultaneously. The configuration of the laminate L to be arranged is as described above. When the arrangement is performed, this preformed body is used by using a preformed body in which a part of the shape of the final resin molded body 6 is molded in advance. It is also possible to arrange in the mold 10 together with the laminate L (see, for example, FIG. 4).

  Next, for example, as shown in FIG. 2 (c), the upper mold 12 is inserted along the inner surface of the side wall of the lower mold 11, and the region of each unit cell C of the upper mold 12 is formed. A convex portion 12a is provided on the lower surface. The convex portion 12a has an upper surface large enough to close the opening 5a of the second metal layer 5 on the upper side of the laminate L and is provided at a position facing each opening 5a. Then, the laminate L is placed in the molding die 10 with the metal layers 4 and 5 being pressed by the convex portion 11 a of the lower mold 11 and the convex portion 12 a of the upper mold 12. At that time, the protrusions 4 b and 5 b of the first metal layer 4 and the second metal layer 5 may be disposed outside the inner space of the mold 10.

  In this state, a resin (“resin” contains a resin raw material liquid and an uncured product) is injected into the mold 10, but the exposed portions (for example, the openings 4 a and 5 a) have the convex portions 11 a and the convex portions 12 a. Therefore, as shown in FIG. 2D, in the obtained molded body, the first electrode layer 2 and the second electrode layer 3 are exposed from the opening 6a. Moreover, the injection | pouring of resin can integrate the several of the laminated bodies L containing the solid polymer electrolyte layer 1, the electrode layers 2 and 3, the 1st metal layer 4, and the 2nd metal layer 5 by insert formation.

[Another embodiment]
(1) In the previous embodiment, an example of a fuel cell that includes two unit cells in the resin molded body and the connecting portion does not protrude to the outside of the resin molded body has been shown. However, in the present invention, FIG. As shown in (c), the resin molding may contain three or more unit cells. In this embodiment, the first metal layer 4, the second metal layer 5, and the connection portion J are continuous, and the four unit cells C <b> 1 to C <b> 4 are formed using a metal plate that partially protrudes outside the resin molded body. An example of connection is shown.

  The structure of each of the unit cells C1 to C4 is basically as described above, but the metal layer protrusions 4b and 5b and the metal plate in which the first metal layer 4 and the second metal layer 5 are integrated are provided. It is different. In this embodiment, since the unit cells C1 to C4 are connected in series, the protruding portions 4b and 5b of the metal layer are provided only in the unit cell C1 and the unit cell C4. That is, only the protrusion 4b of the first metal layer 4 of the unit cell C1 and the protrusion 5b of the second metal layer 5 of the unit cell C4 exist. The necessity and shape of the protruding portions 4b and 5b of the metal layer are as described above.

  The metal plate in which the first metal layer 4 and the second metal layer 5 are integrated via the connection portion J is a member for connecting adjacent unit cells C in series. By using this metal plate instead of arranging the first metal layer 4 and the second metal layer 5 independently, the unit cells C1 to C4 are connected in series only by arranging them in the mold 10. A fuel cell can be manufactured.

  As shown in FIG. 3C, the metal plate includes a first metal layer 4 and a second metal layer 5 which are arranged adjacent to each other in parallel planes and extend outward in the same plane. The extending portions 4j and 5j are connected and integrated by a step portion 4s. Such a stepped portion can be produced by subjecting a metal plate to sheet metal processing. In addition, when performing parallel connection, for example, the first metal layers 4 (or the second metal layers 5) arranged adjacent to each other in the same plane are connected and integrated by the extended extending portion. A metal plate can be used.

  (2) In the previous embodiment, an example was shown in which the opening was formed by the convex portions of the upper and lower molds without using the preform, but in the present invention, as shown in FIG. You may make it form the opening 6a with the convex part 12a of only the one shaping | molding die 12 using the preforming body 7 in which the hole 6a was formed. FIG. 4 shows only one unit cell formation region for the sake of simplification, but in the present invention, a plurality of preforms 7 are used, or a plurality of unit cells are used. A corresponding preform 7 can be used.

  By using such a preform 7, it is possible to facilitate positioning when the laminate L is placed in the mold 10 and to easily form the opening 6 a of the resin molded body 6. In addition, when using the preforming body 7, one metal layer is pressurized by this and the other metal layer is pressurized by the convex part of a shaping | molding die.

  First, as shown to Fig.4 (a), the preforming body 7 is shape | molded previously. The preform 7 has an opening 7 a corresponding to the opening 6 a of the resin molded body 6. That is, the opening 7a is maintained during the subsequent resin molding. Although the external shape of the preform 7 is not particularly limited, it may be smaller than the resin molded body 6 after forming the insert and slightly larger than the solid polymer electrolyte layer 1.

  The preform 7 preferably has a stepped portion 7b for positioning the first metal layer 4 or a stepped portion 7c for positioning the electrode layers 2 and 3 and the solid polymer electrolyte layer 1. Moreover, it is preferable to have the support part 7d for supporting the protrusion part 5b of the 2nd metal layer 5. As shown in FIG.

  Next, as shown in FIG. 4B, the preform 7 is placed in a mold (not shown), and the first metal layer 4 is positioned along the step 7b. At this time, the position of the opening 4 a of the first metal layer 4 substantially coincides with the position of the opening 7 a of the preform 7.

  Next, as shown in FIGS. 4C to 4E, the first electrode layer 2, the solid polymer electrolyte layer 1, and the second electrode layer 3 are moved along the stepped portion 7 c of the preform 7. Position and arrange sequentially. In that case, you may position and arrange what these were laminated and integrated beforehand. At that time, by providing a margin for the size of the stepped portion 7c, the outer periphery of the electrode layers 2 and 3 and the outer periphery of the solid polymer electrolyte layer 1 can be sealed when the resin is injected later.

  Next, as shown in FIG. 4F, the second metal layer 5 is laminated. At this time, the protruding portion 5b of the second metal layer 5 is supported by the support portion 7d, and the opening 5a of the second metal layer 5 is substantially the same as the position of the convex portion 12a provided on the lower surface of the upper mold 12. Arranged to match.

  Next, as shown in FIG. 4 (g), a resin is injected into the mold after setting to mold a fuel cell in which the preform 7 is integrated with the resin mold 6. At that time, the opening 5a is blocked by the convex portion 12a, and the opening 7a of the preform 7 is not blocked by the resin. Therefore, in the obtained molded body, the first electrode layer 2 and the second electrode Layer 3 is exposed from aperture 6a. In addition, since one metal layer 4 is pressed by the preform 7 and the other metal layer 5 is pressed by the convex portion 12a of the mold 10, the first metal layer 4 and the second metal layer 5 are placed on both sides. In this state, the structure is integrated by the resin molded body 6.

  (3) In the previous embodiment, the example in which the size of the opening corresponding to the exposed portion of the metal layer is smaller than the size of the resin opening is shown. However, as shown in FIG. It is also possible to make the size of the opening 6a of the resin molded body 6 smaller than the size of the 4 and 5 openings 4a, 5a. In that case, a part (for example, the periphery) of the electrode layers 2 and 3 exposed from the openings 4a and 5a is sealed by the resin molded body 6, so that the adhesive force between the resin molded body 6 and the electrode layers 2 and 3 is The adhesion between the electrode layers 2 and 3 and the metal layers 4 and 5 can be improved. In order to make the size of the opening 6a of the resin molded body 6 smaller than the size of the openings 4a and 5a, a mold having a convex portion whose upper surface is smaller than the size of the openings 4a and 5a is used. Then, sealing with resin may be performed in a state where the convex portions are in contact with the electrode layers 2 and 3.

  In the above case, the portion corresponding to the opening 6a of the resin molded body 6 cannot be applied to the periphery of the openings 4a and 5a of the metal layers 4 and 5 at the time of molding. For this reason, as shown in FIG.5 (b), by pressurizing parts other than opening 4a, 5a of the metal layers 4 and 5 at the time of shaping | molding, for example using another pin, the 1st metal layer 4 and the 1st The two metal layers 5 can be integrated by the resin molded body 6 in a state of being pressurized from both sides. When such pressurization is performed, a pressurization hole 6b is formed at a portion where the pin or the like is pressed.

  Further, as shown in FIG. 5C, it is possible to provide the resin molded body 6 with a through hole 6 c that does not contribute to power generation. The through-hole 6c is provided with a through-hole in the solid polymer electrolyte layer 1, the electrode layers 2 and 3 and the like, and a through-hole 6c smaller than the hole is provided. , 3 etc. are integrated. According to the through-hole 6c, the solid polymer electrolyte layer 1, the electrode layers 2 and 3, and the metal layers 4 and 5 are integrated by the resin molded body 6 around the through-hole 6c, so that the electrode layers 2 and 3 and the metal layer 4 are integrated. , 5 can be increased.

  The through holes 6c that do not contribute to power generation are provided together with the exposed portions of the electrode layers 2 and 3 for power generation. Further, by pressing the portions other than the through hole 6c at the time of molding using, for example, another pin or the like, the resin molded body 6 presses the first metal layer 4 and the second metal layer 5 from both sides. Can be integrated. Also in that case, the pressurizing hole 6b is formed in the portion where the pin or the like is pressed.

  (4) In the previous embodiment, an example of a hydrogen supply type fuel cell was mainly shown. However, the fuel cell used in the present invention may be any fuel cell that can generate power from fuel, such as methanol. Examples include a reforming type, a direct methanol type, and a hydrocarbon feed type. Various fuel cells using other fuels are also known, and any of them can be adopted.

  In that case, a solid polymer electrolyte layer, an electrode layer, and the like corresponding to various fuel cells are used. For example, in the case of the direct methanol type, it is generally preferable to use an aromatic hydrocarbon-based solid polymer electrolyte in order to prevent the crossover from being large in the Nafion system. In addition, it is preferable to use a mixture of two kinds of catalysts (Pt, Ru) in the electrode layer.

(5) In the previous embodiment, an example in which the size of the exposed portion of the first metal layer and / or the second metal layer is integrated with the resin molded body so that the size of the opening is substantially equal is shown. However, in the present invention, as shown in FIGS. 6A to 6B, a plurality of first metal layers 4 and / or second metal layers 5 are provided by providing one large opening 6a on one surface. You may make it expose the whole number or one part of an exposed part. Note that FIG. 6 shows only one unit cell for the sake of simplicity.
Further, by providing two or more large openings 6a on one side, half or less of the plurality of exposed portions of the first metal layer 4 and / or the second metal layer 5 may be exposed. That is, in this invention, you may shape | mold so that two or more exposed parts may be exposed from one opening 6a.

  (6) In the previous embodiment, the first conductive layer and the second conductive layer are formed from the first metal layer and the second metal layer having exposed portions that partially expose the first electrode layer and the second electrode layer. In the present invention, it is possible to use a conductive layer having no exposed portion as the first conductive layer and / or the second conductive layer. In that case, a conductive layer having gas permeability and gas diffusibility can be used. Examples of such a conductive layer include a porous metal layer, a porous conductive polymer layer, a conductive rubber layer, a conductive fiber layer, Examples thereof include conductive paste and conductive paint.

  (7) In the previous embodiment, the example in which the first electrode layer and the second electrode layer are exposed from the opening of the resin molded body is shown. However, in the present invention, the opening of the resin molded body and the first electrode layer or A porous layer may be interposed between the second electrode layer. In order to interpose a porous layer, a porous layer may be provided in advance on the outside of a metal layer or a conductive layer as a laminate used for insert molding. The porous layer and the metal layer or the conductive layer may be bonded in advance, or may be simply laminated.

  Examples of the material forming the porous layer include a porous film, a nonwoven fabric, and a woven fabric that can withstand the temperature at the time of insert molding.

  (8) In the previous embodiment, the example in which the opening for exposing the first electrode layer and the second electrode layer to the outside is provided in the resin molded body. However, in the present invention, a gas or liquid is provided inside the resin molded body. It is also possible to provide a flow path for supplying. In that case, an electrode layer can be exposed to the flow path by performing insert molding as described above using a preform with a flow path provided on the inner surface on the side in contact with the conductive layer.

  (9) In the previous embodiment, one first conductive layer of the adjacent unit cells, the other second conductive layer, and the connection portion are formed of a metal layer made of a continuous metal plate. Although an example has been shown, the connecting portion in the present invention may be any as long as it can electrically connect one first conductive layer and the other second conductive layer.

  For example, it is possible to electrically connect one first conductive layer and the other second conductive layer with another member. For example, it is possible to perform solder connection using a member such as a metal wire. Moreover, the member which comprises a connection part, and the conductive layer may be electrically connected by contacting mechanically. For example, it is also possible to electrically connect one first conductive layer and the other second conductive layer by bringing them into contact with the conductive layer using a member such as a metal plate and integrating them with a resin molded body. It is.

  (10) In the previous embodiment, an example in which a plurality of unit cells are arranged in the same plane has been shown, but each unit cell can also be arranged three-dimensionally. For example, each unit cell may be arranged on each side such as two L-shaped sides, two or four sides of a square or rectangle, or two or three sides of a triangle.

  Thus, when each unit cell is arranged three-dimensionally, after three-dimensionally forming at the time of insert formation and using a flexible material to form two-dimensionally at the time of insert formation, this is three-dimensionally formed. There is a method to deform.

  In the former case, a metal plate in which one first conductive layer of the adjacent unit cells, the other second conductive layer, and the connection portion are continuous depends on the angle of the adjacent unit cells. It is preferably refracted. For example, when unit cells are arranged on the four sides of a square (square prism), the metal plate is refracted at an angle of about 90 °.

  Using such a metal plate, inserts are formed in a state in which the laminate constituting the unit cell is arranged on each of the four sides of the mold 10 having a quadrangular prism cavity and electrically connected to each other. By this method, a fuel cell in which unit cells are arranged on the four sides of the quadrangular prism can be manufactured.

It is a figure which shows an example of the fuel cell of this invention, (a) is a top view, is the II arrow sectional drawing, (c) is the II-II arrow sectional drawing. Front view sectional drawing which shows an example of the manufacturing method of the fuel cell of this invention It is a figure which shows the other example of the fuel cell of this invention, (a) is a perspective view, (b) is a top view, (c) is a perspective view which shows the principal part. The perspective view which shows the other example of the manufacturing method of the fuel cell of this invention. Front view sectional drawing which shows the other example of the fuel cell of this invention It is a figure which shows the other example of the fuel cell of this invention, (a) is a top view, (b) is front view sectional drawing.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid polymer electrolyte layer 2 1st electrode layer 3 2nd electrode layer 4 1st metal layer (1st conductive layer)
4a Opening (exposed part)
5 Second metal layer (second conductive layer)
5a Opening (exposed part)
6 Resin molded body 6a Opening 7 Preliminary molded body 7a Opening 10 Mold 11a Convex part 12a Convex part C Unit cell L Laminate J Connection part

Claims (8)

A solid polymer electrolyte layer, a first electrode layer and a second electrode layer provided on both sides of the solid polymer electrolyte layer, and a first conductive layer and a second conductive layer respectively disposed on the outer sides of the electrode layers; A plurality of unit cells having,
A connection part for electrically connecting the conductive layers of any unit cell and other unit cells;
A fuel cell comprising: a resin molded body obtained by integrating those unit cells and the connecting portion by insert molding.   2. The fuel cell according to claim 1, wherein one first conductive layer, the other second conductive layer, and the connection portion of the adjacent unit cells are formed of a metal layer made of a continuous metal plate.   The first conductive layer includes a first metal layer having an exposed portion that partially exposes the first electrode layer, and the second conductive layer includes an exposed portion that partially exposes the second electrode layer. The fuel cell according to claim 1, comprising a second metal layer.   The fuel cell according to claim 3, wherein the resin molded body has an opening provided at a position corresponding to an exposed portion of the first metal layer or the second metal layer. A plurality of laminates including a solid polymer electrolyte layer, a first electrode layer and a second electrode layer disposed on both sides thereof, and a first conductive layer and a second conductive layer disposed on the outside thereof, Arranging the laminate and the conductive layers of the other laminate in the mold in a state where the conductive layers are electrically connected to each other by the connecting portion;
And a step of molding a resin molded body that integrates the laminate and the connection portion by injecting a resin into the mold.   6. The fuel cell according to claim 5, wherein one of the first conductive layers, the other second conductive layer, and the connection portion of the adjacent laminate are formed of a metal layer made of a continuous metal plate. Production method.   The first conductive layer includes a first metal layer having an exposed portion that partially exposes the first electrode layer, and the second conductive layer includes an exposed portion that partially exposes the second electrode layer. The method for producing a fuel cell according to claim 5, comprising a second metal layer.   The method of manufacturing a fuel cell according to claim 7, wherein the resin molded body has an opening provided at a position corresponding to an exposed portion of the first metal layer or the second metal layer.

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