JP2010192432A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell endowed with an enhanced power generation efficiency and still no fear of deterioration of mass-producibillity even in case of a thickness of a solid polymer electrolyte being made thinner. <P>SOLUTION: The fuel cell is provided with a solid polymer electrolyte layer 1, a first electrode layer and a second electrode layer arranged on both sides of the solid polymer electrolyte layer 1, and each of these layers are insert-molded and integrated into a resin molded body 6. A reinforcing layer 8 is arranged on a periphery part of at least one of the surfaces of the solid polymer electrolyte layer 1. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention comprises a solid polymer electrolyte layer and a first electrode layer and a second electrode layer provided on both sides of the solid polymer electrolyte layer, and these layers are integrated with a resin molded body obtained by insert molding. The present invention relates to a fuel cell.

  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 includes a plate-like solid polymer electrolyte and electrode plates (catalyst layer + conductive porous body) provided on both sides thereof, and each of these layers. There has been proposed a cell member for a fuel cell in which the periphery of the fuel cell is integrated with a resin frame which is insert-molded. This cell member for a fuel cell realizes a simple structure and manufacturing method by integrating the layers with an insert-molded resin frame.

Japanese Patent Laid-Open No. 2005-150008 JP 2005-11624 A

  By the way, in order to further reduce the size and weight of the fuel cell, it is necessary to reduce the thickness of the fuel cell, that is, to reduce the thickness of the solid polymer electrolyte and the electrode plate which are constituent members of the fuel cell. Further, in order to improve the conductivity of hydrogen ions and increase the power generation efficiency, it is necessary to reduce the thickness of the solid polymer electrolyte.

  However, in the cell member for a fuel cell of Patent Document 2 described above, if the thickness of the solid polymer electrolyte is made too thin, the anode after the insert molding is formed when the outer periphery of the solid polymer electrolyte and the outer periphery of the electrode plate are close to each other. It has been found that hydrogen gas tends to diffuse from the cathode side to the cathode side, resulting in a decrease in power generation efficiency. In addition, if the thickness of the solid polymer electrolyte is made too thin, it may be broken or deformed by the resin pressure (pressure due to resin flow) during insert molding, and the handling property may be reduced. There is a problem that the mass productivity becomes worse.

  Accordingly, an object of the present invention is to provide a fuel cell in which power generation efficiency is improved and mass productivity is not reduced even when the thickness of a solid polymer electrolyte is reduced.

  In order to solve the above problems, a fuel cell according to the present invention includes a solid polymer electrolyte layer, and a first electrode layer and a second electrode layer provided on both sides of the solid polymer electrolyte layer. A fuel cell integrated with a molded resin molded body, wherein a reinforcing layer is provided on a peripheral portion of at least one surface of the solid polymer electrolyte layer.

  A fuel cell according to the present invention includes a solid polymer electrolyte layer and a resin molded body in which the first electrode layer and the second electrode layer provided on both sides of the solid polymer electrolyte layer are insert-molded. It is integrated. According to the fuel cell of the present invention, the reinforcing layer is provided on the peripheral portion of at least one surface of the solid polymer electrolyte layer. Therefore, even when the thickness of the solid polymer electrolyte layer is reduced, the solid polymer electrolyte layer The distance between the outer periphery and the outer periphery of the first and second electrode layers is maintained, and diffusion of hydrogen gas from the anode side to the cathode side after insert molding can be prevented. As a result, it is possible to provide a fuel cell that can improve power generation efficiency even when the thickness of the solid polymer electrolyte is reduced.

  Furthermore, according to the fuel cell of the present invention, since the reinforcing layer is provided on the peripheral portion of at least one surface of the solid polymer electrolyte layer, the solid polymer electrolyte can be obtained even when the thickness of the solid polymer electrolyte layer is reduced. It is possible to prevent the layer from being broken or deformed by the resin pressure from the peripheral edge generated during the insert molding. Moreover, handling property is not impaired. As a result, it is possible to provide a fuel cell that does not degrade mass productivity.

  In this invention, it is preferable that the 1st metal layer and 2nd metal layer which have an opening are provided in the further outer side of the said 1st electrode layer and the said 2nd electrode layer.

  According to this configuration, since the first metal layer and the second metal layer have holes, fuel, oxygen, and the like can be supplied to the first electrode layer and the second electrode layer through the holes. Further, by providing the first metal layer and the second metal layer further outside the first electrode layer and the second electrode layer, the first electrode layer and the second electrode layer are brought into contact with the solid polymer electrolyte layer with sufficient pressure. It is possible to reduce the contact resistance and improve the output characteristics.

  In the fuel cell of the present invention, the reinforcing layer is sandwiched between the solid polymer electrolyte layer and the first electrode layer or the second electrode layer, and the solid polymer electrolyte layer and the reinforcing layer It is preferable that the outer periphery of is protruded from the outer periphery of the first electrode layer or the second electrode layer.

  According to this configuration, since the reinforcing layer is sandwiched between the solid polymer electrolyte layer and the first electrode layer or the second electrode layer, the reinforcing effect on the solid polymer electrolyte layer is further increased. Moreover, since the outer periphery of the solid polymer electrolyte layer and the reinforcing layer protrudes from the outer periphery of the first electrode layer or the second electrode layer, contact between the outer periphery of the first electrode layer and the outer periphery of the second electrode layer is prevented. Since the conduction between both electrode layers can be prevented, the output characteristics of the fuel cell are improved. Moreover, when the outer periphery of a solid polymer electrolyte layer and a reinforcement layer protrudes from the outer periphery of a 1st electrode layer or a 2nd electrode layer, compared with the case where all the outer periphery of each layer is the same, a 1st electrode layer Since the distance (stroke) between the outer periphery and the outer periphery of the second electrode layer becomes longer and the resin therebetween increases, the diffusion of fuel gas from one of the first electrode layer or the second electrode layer to the other is prevented. As a result, the output characteristics of the fuel cell are improved.

  In the fuel cell of the present invention, the reinforcing layer is preferably provided on both surfaces of the solid polymer electrolyte layer.

  According to this configuration, since the reinforcing layer is provided on both surfaces of the solid polymer electrolyte layer, the reinforcing effect on the solid polymer electrolyte layer is further increased. Further, the distance between the outer periphery of the first electrode layer and the outer periphery of the second electrode layer is further increased, and the diffusion of fuel gas from one of the first electrode layer or the second electrode layer to the other is further prevented. Can do.

  In the fuel cell of the present invention, the reinforcing layer is preferably provided only on one side of the solid polymer electrolyte layer.

  If the reinforcing layer is provided on both surfaces of the solid polymer electrolyte layer, alignment becomes difficult. However, if the reinforcing layer is provided only on one surface of the solid polymer electrolyte layer, alignment is facilitated and manufacturing becomes easy.

  In the fuel cell of the present invention, it is preferable that catalyst layers are provided on both surfaces of the solid polymer electrolyte layer, respectively, and the cathode-side catalyst layer is larger than the anode-side catalyst layer.

  When hydrogen gas is used as the reducing gas supplied to the anode side and air is used as the oxidizing gas supplied to the cathode side, the air is not diffusible compared to hydrogen gas, but the cathode catalyst layer is connected to the anode side. By making it larger than the catalyst layer, the reaction on the cathode side becomes good and the characteristics of the fuel cell are improved. Further, if a reinforcing layer is provided only on the anode side surface of the solid polymer electrolyte layer, and an anode side catalyst layer is provided on the inner side of the reinforcing layer, the cathode side catalyst layer becomes the anode side catalyst layer. It is also easy to configure to be larger than the above.

It is a figure which shows an example of the fuel cell of this invention, (a) is a top view, (b) is II sectional drawing of (a), (c) is a bottom view. 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 sectional view showing the structure of the fuel cell of Comparative Example 1 The graph which shows the change of the output voltage of the fuel cell in Example 1 etc. Sectional drawing of the fuel cell which concerns on another embodiment of this invention. Front view sectional drawing which shows the structure of the fuel cell of Example 2. The graph which shows the IV characteristic of the fuel cell in Example 2

  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, in which FIG. 1A is a top view, FIG. 1B is a cross-sectional view taken along the line II of FIG. 1A, and FIG.

  As shown in FIG. 1, the fuel cell of the present invention includes a solid polymer electrolyte layer 1, and a first electrode layer 2 and a second electrode layer 3 provided on both sides of the solid polymer electrolyte layer 1. Yes. In the present embodiment, an example in which the first metal layer 4 and the second metal layer 5 are provided further outside the electrode layers 2 and 3 is shown.

  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 reduce the thickness of the solid polymer electrolyte layer 1. However, in consideration of ion conduction function, strength, handling property, etc., 10 to 300 μm can be used, but 15 to 60 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 9 having an electrode catalytic action on the base material. The catalyst 9 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 periphery of the first electrode layer 2 and the second electrode layer 3 is preferably smaller than the outer periphery of the solid polymer electrolyte layer 1. That is, the outer shape of the first electrode layer 2 and the second electrode layer 3 is preferably smaller than the outer shape of the solid polymer electrolyte layer 1.

  In the present invention, the reinforcing layer 8 is provided on the peripheral edge of the surface of the solid polymer electrolyte layer 1. In the present embodiment, an example in which the reinforcing layer 8 is provided on both surfaces of the solid polymer electrolyte layer 1 is shown, but only one surface of the solid polymer electrolyte layer 1 may be used.

  In the present embodiment, the reinforcing layer 8 has a structure sandwiched between the solid polymer electrolyte layer 1 and the first electrode layer 2 and between the solid polymer electrolyte layer 1 and the second electrode layer 3. The outer periphery of the reinforcing layer 8 is the same as the outer periphery of the solid polymer electrolyte layer 1, and the outer periphery of the first electrode layer 2 and the second electrode layer 3 is smaller than the outer periphery of the catalyst layer 9 and the solid polymer electrolyte layer 1. Is preferred.

  As the reinforcing layer 8, for example, PEN resin (polyethylene naphthalate), PET resin (polyethylene terephthalate), acrylic resin, or the like can be used.

  The thinner the reinforcing layer 8 is, the more effective it is for reducing the overall thickness. However, in consideration of electrode reaction, strength, handling property, etc., 20 to 200 μm is preferable, and 40 to 100 μm is more preferable.

  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. 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 4a portion (opening ratio) is preferably 3 to 50%, and more preferably 5 to 20%.

  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.

  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, the metal layer 4 and the metal layer 5 are electrodes of a unit cell. It is preferable that the protruding portions 4b and 5b are provided so as to 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 is a resin molding in which the solid polymer electrolyte layer 1, the electrode layers 2 and 3, the metal layers 4 and 5, the reinforcing layer 8, and the catalyst layer 9 are insert-molded as described above. It is integrated with the body 6. In the present invention, it is preferable to cover the entire surface or substantially the entire surface of the first metal layer 4 and / or the second metal layer 5 with the resin molded body 6, and cover the entire surface or approximately the entire surface of the first metal layer 4 and the second metal layer 5. More preferably, the resin molded body 6 is covered. In that case, as will be described later, the resin molded body 6 may partially include a preformed body. 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, the resin molded body 6 is pressed 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 insert molding is performed 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 opening 4a and 5a.

  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, a thermoplastic elastomer, rubber, or the like can be used. In that case, it is possible to make the whole fuel cell flexible by using another material having flexibility.

  The total thickness of the resin molded body 6 is preferably 0.3 to 4 mm, more preferably 0.5 to 2 mm, from the viewpoint of the strength of integration by the resin, the pressure to pressurize the metal layers 4 and 5, and thinning. preferable. In particular, the thickness of the resin molded body 6 covering the metal layers 4 and 5 is preferably 0.2 to 1.5 mm, and preferably 0.3 to 1.0 mm from the viewpoint of pressure to pressurize the metal layers 4 and 5. Is more preferable.

  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 following manufacturing method. That is, in this manufacturing method, as shown in FIGS. 2A to 2D, the solid polymer electrolyte layer 1, the reinforcing layer 8, the catalyst layer 9, the first electrode layer 2 disposed on both sides, and the first layer A step of disposing a laminate L of the two-electrode layer 3 and the first metal layer 4 and the second metal layer 5 disposed on the outside thereof in the mold 10. In this embodiment, the 1st metal layer 4 and the 2nd metal layer 5 have the exposed part (for example, opening 4a, 5a) which exposes the 1st electrode layer 2 and the 2nd electrode layer 3 partially, An example in which the exposed portion is arranged in the molding die 10 in a state where the exposed portion is closed by the convex portions 11a and 12a of the molding die 10 will be described.

  Further, the fuel cell manufacturing method includes a step of molding the resin molded body 6 in which the laminate L is integrated 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, for example, as shown in FIG. 2A, a lower mold 11 having a convex portion 11a on the bottom surface is prepared. 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 illustrated in FIG. 2B, the laminate L is disposed on the bottom surface of the lower mold 11. At that time, the upper surface of the convex portion 11a on the bottom surface is disposed at a position where the opening 4a of the first metal layer 4 can be closed. 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. 2C, the upper mold 12 is inserted along the inner surface of the side wall of the lower mold 11, and a convex portion 12 a is provided on the lower surface of the upper mold 12. . 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. Further, by injecting the resin, the solid polymer electrolyte layer 1, the reinforcing layer 8, the catalyst layer 9, the first electrode layer 2 and the second electrode layer 3, the first metal layer 4 and the second metal layer 5 are formed by insert formation. Can be integrated.

[Another embodiment]
(1) In the previous embodiment, an example of a fuel cell including one unit cell in the resin molding was shown. However, in the present invention, as shown in FIGS. The molded body may include two or more unit cells. In this embodiment, an example in which four unit cells C <b> 1 to C <b> 4 connected using a metal plate J in which the first metal layer 4 and the second metal layer 5 are integrated is shown in a resin molded body.

  In this fuel cell, a fuel cell as shown in the previous embodiment is used as a unit cell C, a plurality of unit cells C are arranged in parallel on the same plane, and the resin is electrically connected to each other. The molded body 6 is formed integrally and a plurality of unit cells C1 to C4 are integrated. Such a fuel cell uses a plurality of laminates L in the step of arranging the laminates L in the mold 10 in the above-described manufacturing method as shown in FIG. Can be manufactured by a method of arranging them in the mold 10 in a connected state.

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

  As shown in FIG. 3C, the metal plate J 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. The extended portions 4j and 5j are connected and integrated by a stepped portion 4s. Such a stepped portion can be produced by subjecting a metal plate to sheet metal processing.

  In the present invention, instead of connecting the unit cell C using the metal plate J in which the first metal layer 4 and the second metal layer 5 are integrated, each terminal is connected to the first metal layer 4 and the second metal layer 5. A part may be provided, and both may be connected by a connection plate, connection wiring, or the like.

  (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. 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, 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. Moreover, it is preferable to use a two-type mixture (Pt, Ru) for the catalyst in the electrode layer.

  (4) In the previous embodiment, the resin molded body 6 is used so that the size of the openings 4a, 5a of the first metal layer 3 and / or the second metal layer 5 is substantially equal to the size of the openings 6a. In the present invention, the total number of the plurality of openings 4a and 5a of the first metal layer 4 and / or the second metal layer 5 is provided by providing one large opening 6a on one side. Or you may make it expose a part.

  Further, by providing two or more large openings 6a on one side, half or less of the plurality of openings 4a, 5a of the first metal layer 4 and / or the second metal layer 5 may be exposed. Good. That is, in this invention, you may shape | mold so that two or more apertures 4a and 5a may be exposed from one aperture 6a.

  (5) In the previous embodiment, the example in which the reinforcing layer 8 is provided on both surfaces of the solid polymer electrolyte layer 1 has been described, but the reinforcing layer 8 is provided only on one surface of the solid polymer electrolyte layer 1. Also good. The catalyst layers 9 provided on both surfaces of the solid polymer electrolyte layer 1 may be such that the cathode-side catalyst layer 9 is larger than the anode-side catalyst layer 9. FIG. 7A is a front sectional view of the fuel cell according to this embodiment.

  In this fuel cell, the reinforcing layer 8 is provided only on the anode side surface of the solid polymer electrolyte layer 1. An anode side catalyst layer 9 a is provided inside the reinforcing layer 8. On the other hand, the cathode side catalyst layer 9b is provided so as to be approximately the same as the size of the solid polymer electrolyte layer 1, and is larger than the anode side catalyst layer 9a. The anode side electrode layer 2 is set to have substantially the same size as the anode side catalyst layer 9a, and the cathode side electrode layer 3 is set to have substantially the same size as the cathode side catalyst layer 9b. However, the anode side electrode layer 2 does not necessarily have the same size as the anode side catalyst layer 9a.

  FIG. 7B shows an example of a method for manufacturing the fuel cell shown in FIG. As shown in the figure, an anode-side laminate 20 prepared by cutting out a laminate of the solid polymer electrolyte layer 1, the anode-side catalyst layer 9a, and the anode-side electrode layer 2 is prepared. A cathode-side laminate 30 prepared by cutting out a laminate of the solid polymer electrolyte layer 1, the cathode-side catalyst layer 9b, and the cathode-side electrode layer 3 is prepared. The reinforcing polymer 8 and the solid polymer electrolyte layer 1 of the anode side laminate 20 are joined to the surface of the solid polymer electrolyte layer 1 of the cathode side laminate 30.

  Examples and the like specifically showing the configuration and effects of the present invention will be described below.

Example 1
A stainless steel plate having a thickness of 0.2 mm plated with gold was pressed into a shape shown in FIG. 1 (a major portion having a major axis of 33 mm and a minor axis of 12 mm) and punched to produce two stainless steel plates to be metal layers 4 and 5.

  A Nafion film (Nafion 112 manufactured by DuPont, 33 mm × 12 mm, thickness 15 μm) was used as the solid polymer electrolyte layer 1 (cation exchange membrane). As shown in FIG. 1, PEN resin (polyethylene naphthalate) having a width of 500 μm and a thickness of 40 μm was provided as a reinforcing layer 8 on the periphery of both surfaces of the solid polymer electrolyte layer 1.

  Further, as shown in FIG. 1, a catalyst layer 9 was provided at substantially the same thickness as the reinforcing layer 8 at the center of both surfaces of the solid polymer electrolyte layer 1. As the platinum catalyst, a 20% platinum-supported carbon catalyst (EC-20-PTC) manufactured by US Electrochem Co., Ltd. was used. This platinum catalyst, carbon black (Akzo Ketjen Black EC), and polyvinylidene fluoride (Kayner) were mixed at a ratio of 75% by weight, 15% by weight, and 10% by weight, respectively, and dimethylformamide was added by 2.5% by weight. % In a ratio of a polyvinylidene fluoride solution in a mixture of the platinum catalyst, carbon black, and polyvinylidene fluoride, and dissolved and mixed in a mortar to prepare a catalyst paste. The solid polymer electrolyte layer 1 It was applied to the surface.

  As the electrode layers 2 and 3, carbon paper (TGP-H-90 manufactured by Toray, thickness of 370 μm) was cut into 33 mm × 12 mm and used.

A laminate of the solid polymer electrolyte layer 1, the catalyst layer 9, the reinforcing layer 8, and the electrode layers 2 and 3 is sandwiched at the center of the two stainless steel plates, and two sheets are used using a mold as shown in FIG. The stainless steel plate was placed in the mold in a state where pressure (1 ton) was applied from both sides. In that state, a resin (manufactured by Prime Polymer Co., Ltd., polypropylene resin, J-700GP) was injected into the mold at 195 ° C. (injection pressure 400 kgf / cm ² ), cooled, and then taken out from the mold. A fuel cell having an outer size of 35 mm × 14 mm × 2.2 mm thick was obtained.

Comparative Example 1
In Example 1, the reinforcing layer 8 was not provided, and the outer circumferences of the solid polymer electrolyte layer 1, the catalyst layer 9, and the electrode layers 2 and 3 were all the same (see FIG. 5). Other sizes and thicknesses were the same as those in Example 1.

Reference example 1
As Reference Example 1, a fuel cell in which the thickness of the solid polymer electrolyte layer 1 of Comparative Example 1 was 30 μm was produced.

  The fuel cells of Example 1, Comparative Example 1, and Reference Example 1 were prepared, and the cell characteristics were evaluated. The battery characteristics were evaluated by setting power in an evaluation jig having an internal space on the anode side and the cathode side being open to the atmosphere, and supplying hydrogen to the internal space on the anode side at 12 mL / min. For battery characteristics, a change in output voltage was measured while changing the current using a fuel cell evaluation system manufactured by Toyo Technica. The change in the output voltage at that time is shown in FIG.

  It was found that the output voltage of the fuel cell with the thin solid polymer electrolyte layer (Comparative Example 1) is lower than that of the fuel cell with the thick solid polymer electrolyte layer (Reference Example 1). That is, from the viewpoint of increasing the power generation efficiency, it is preferable to make the solid polymer electrolyte layer thin, but if it is made too thin, the output voltage is lowered. However, even if the solid polymer electrolyte layer is thinned, the output voltage of the fuel cell (Example 1) provided with the reinforcing layer is greatly improved as compared with the fuel cell without the reinforcing layer (Comparative Example 1). understood.

Example 2-1
As Example 2-1, a fuel cell including a solid polymer electrolyte layer 1, electrode layers 2 and 3, a reinforcing layer 8, and catalyst layers 9a and 9b as shown in FIG. 8 was prepared, and IV characteristics were evaluated. The size of the solid polymer electrolyte layer 1 was 13 × 34 mm, and the sizes of the anode side catalyst layer 9a and the cathode side catalyst layer 9b were 12 × 33 mm, respectively. The reinforcing layer 8 was provided with a width of 0.5 mm around the anode side catalyst layer 9a and the cathode side catalyst layer 9b.

Example 2-2
As Example 2-2, a fuel cell including the solid polymer electrolyte layer 1, the electrode layers 2 and 3, the reinforcing layer 8, and the catalyst layers 9a and 9b as shown in FIG. 8 was prepared, and IV characteristics were evaluated. The reinforcing layer 8 is provided only on the anode side surface of the solid polymer electrolyte layer 1. The size of the solid polymer electrolyte layer 1 was 13 × 34 mm, the size of the anode side catalyst layer 9a was 12 × 33 mm, and the size of the cathode side catalyst layer 9b was 13 × 34 mm. The reinforcing layer 8 was provided with a width of 0.5 mm around the anode side catalyst layer 9a.

Example 2-3
As Example 2-3, a fuel cell including the solid polymer electrolyte layer 1, the electrode layers 2 and 3, the reinforcing layer 8, and the catalyst layers 9a and 9b as shown in FIG. 8 was prepared, and IV characteristics were evaluated. The reinforcing layer 8 is provided only on the anode side surface of the solid polymer electrolyte layer 1. The size of the solid polymer electrolyte layer 1 was 13 × 34 mm, the size of the anode side catalyst layer 9a was 11 × 32 mm, and the size of the cathode side catalyst layer 9b was 13 × 34 mm. The reinforcing layer 8 was provided with a width of 1.0 mm around the anode side catalyst layer 9a.

Example 2-4
As Example 2-4, a fuel cell including the solid polymer electrolyte layer 1, the electrode layers 2 and 3, the reinforcing layer 8, and the catalyst layers 9a and 9b as shown in FIG. 8 was prepared, and the IV characteristics were evaluated. The reinforcing layer 8 is provided only on the anode side surface of the solid polymer electrolyte layer 1. The size of the solid polymer electrolyte layer 1 was 13 × 34 mm, the size of the anode side catalyst layer 9a was 10 × 31 mm, and the size of the cathode side catalyst layer 9b was 13 × 34 mm. The reinforcing layer 8 was provided with a width of 1.5 mm around the anode side catalyst layer 9a.

  FIG. 9 shows a graph of IV characteristics of the fuel cells of Example 2-1, Example 2-2, Example 2-3, and Example 2-4. In Example 2-2, since the reinforcing layer 8 is provided only on one side of the solid polymer electrolyte layer 1, the alignment at the time of manufacture is easier than in Example 2-1, but the IV characteristics are lowered. ing. This seems to be because hydrogen gas diffusion from the anode side to the cathode side cannot be sufficiently prevented when the reinforcing layer 8 is only on one side.

  In Example 2-3 and Example 2-4, the width of the reinforcing layer 8 is made wider than that in Example 2-2. Along with this, the size of the anode-side catalyst layer 9a in Examples 2-3 and 2-4 is smaller than that in Example 2-2. If the anode side catalyst layer 9a is small, performance deterioration may occur due to deterioration of the electrode catalyst action, but the performance improvement effect by widening the reinforcing layer 8 is large, and as a result, the IV characteristics are good. In addition, Example 2-4 has substantially the same IV characteristics as Example 2-1 in which the reinforcing layer 8 is on both sides even if the reinforcing layer 8 is only on one side. However, Example 2-4 is easier to align and easier to manufacture than Example 2-1.

DESCRIPTION OF SYMBOLS 1 Solid polymer electrolyte layer 2 1st electrode layer 3 2nd electrode layer 4 1st metal layer 4a Opening 5 2nd metal layer 5a Opening 6 Resin molding 6a Opening 7 Pre-molding 7a Opening 8 Reinforcement layer 9 Catalyst layer 10 Mold 11a Convex part 12a Convex part C Unit cell L Laminate

Claims (6)

A fuel cell comprising a solid polymer electrolyte layer and a first electrode layer and a second electrode layer provided on both sides of the solid polymer electrolyte layer, each of which is integrated with a resin molded body formed by insert molding. And
A fuel cell in which a reinforcing layer is provided on a peripheral portion of at least one surface of the solid polymer electrolyte layer.   2. The fuel cell according to claim 1, wherein the first metal layer and the second metal layer having an opening are provided further outside of the first electrode layer and the second electrode layer. The reinforcing layer is sandwiched between the solid polymer electrolyte layer and the first electrode layer or the second electrode layer,
3. The fuel cell according to claim 1, wherein outer peripheries of the solid polymer electrolyte layer and the reinforcing layer protrude from outer peripheries of the first electrode layer or the second electrode layer.   The fuel cell according to claim 1, wherein the reinforcing layer is provided on both surfaces of the solid polymer electrolyte layer.   The fuel cell according to claim 1, wherein the reinforcing layer is provided only on one side of the solid polymer electrolyte layer.   6. The fuel cell according to claim 1, wherein catalyst layers are provided on both surfaces of the solid polymer electrolyte layer, respectively, and the cathode-side catalyst layer is larger than the anode-side catalyst layer.

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