JP2009295298A - Fuel cell and its manufacturing method - Google Patents

Abstract

The present invention relates to a method of manufacturing a fuel cell in which a gasket is injection-molded on the outer periphery of a membrane electrode assembly, and provides a method of manufacturing a fuel cell capable of remarkably improving the manufacturing efficiency.
SOLUTION: A gasket G and a connecting portion Q extending from one side of the gasket G to the outside thereof are integrally formed on the periphery of the MEGA 10A by injection molding, and the connecting portion Q is formed by injection molding on the periphery of a separate MEGA 10A. The gasket G is molded so that the other side is connected, and the connecting portion Q extending from one side of the gasket G to the outside thereof is integrally molded, and this is repeated, and a cell unit comprising the MEGA 10A and the gasket G at the periphery thereof A separator SP is inserted between the step of forming an intermediate body in which the CU is connected at the connecting portion Q, and the cell units CU that are folded back at the connecting portion Q while the cell units CU are sequentially folded back. A second step of stacking the stacked unit of cell units.
[Selection] Figure 7

Description

  The present invention relates to a fuel cell in which a plurality of single cells are stacked and a method for manufacturing the same.

  A polymer electrolyte fuel cell includes a membrane electrode assembly (MEA) comprising an ion-permeable electrolyte membrane, an anode-side catalyst layer and a cathode-side catalyst layer sandwiching the electrolyte membrane, and a membrane electrode assembly (MEA). A separator is arranged on the outer side to form a single cell. A gas diffusion layer (GDL) for promoting gas flow and enhancing current collection efficiency is provided outside each catalyst layer to form a membrane electrode assembly (MEGA: MEA and GDL assembly). In some cases, a separator is disposed outside the diffusion layer. In actuality, these single cells are stacked in stages corresponding to the power generation performance, thereby forming a fuel cell stack.

  In the fuel cell described above, hydrogen gas or the like is provided as a fuel gas to the anode electrode, oxygen or air is provided as the oxidant gas to the cathode electrode, and each electrode has a gas flow layer in its in-plane direction. Then, the gas diffused in the gas diffusion layer is led to the electrode catalyst to cause an electrochemical reaction. In this electrochemical reaction, protons (hydrogen ions) and water generated at the anode electrode pass through the electrolyte membrane in a hydrated state to reach the cathode electrode, and generated water is generated at the cathode electrode.

  A seal gasket is formed on the outer periphery of the above-described MEA (or MEGA), and cooling for suppressing temperature rise of the fuel gas, the oxidant gas, and the membrane electrode assembly through the manifold formed on the gasket. A fluid such as water is provided to the membrane electrode assembly and its surroundings in a posture in which their sealing properties are ensured.

  This seal gasket is generally molded by placing a membrane electrode assembly in a molding die and injection molding a resin, and Patent Document 1 can be cited as the prior art.

  For example, a gasket is formed on the outer periphery of a single-cell membrane electrode assembly as in the manufacturing method of Patent Document 1, and separators are disposed on both sides of the membrane-electrode assembly to form a single cell. Single cells are stacked and a compressive force is applied to produce a fuel cell stack.

JP 2007-188893 A

  In the conventional gasket forming method including the above-mentioned Patent Document 1, the injection molding is performed for each radix unit cell corresponding to the power generation capacity, and a predetermined number of manufactured unit cells are stacked. There is plenty of room to improve manufacturing efficiency, such as the complexity of carrying out injection molding and assembly of separators for each single cell, and the processing effort when stacking while positioning single cells with high precision. . In addition, with increasing interest in the impact on the natural environment, the demand for mass production of fuel cells, such as electric vehicles and hybrid vehicles, is increasing. The above-described conventional manufacturing method is reviewed, and the development of a method for forming a seal gasket around the membrane electrode assembly periphery and, more particularly, a method for manufacturing a fuel cell is an urgent issue in the technical field.

  The present invention has been made in view of the above-described problems, and relates to a method for manufacturing a fuel cell in which a gasket is injection-molded on the outer periphery of a membrane electrode assembly, and the manufacturing efficiency is markedly higher than that of a conventional manufacturing method. It is an object of the present invention to provide a fuel cell manufacturing method that can be improved and a fuel cell manufactured by the manufacturing method.

  In order to achieve the above object, a method of manufacturing a fuel cell according to the present invention is formed by integrally molding a gasket and a connecting portion extending from one side of the gasket to the outside thereof by injection molding around the periphery of the membrane electrode assembly. Forming a gasket on the periphery of the membrane electrode assembly by injection molding so that the other side is connected to the connecting part and integrally forming a connecting part extending from one side of the gasket to the outside, and repeating this, A first step of forming an intermediate body in which a cell unit comprising a membrane electrode assembly and a peripheral gasket is connected at the connecting portion, and a cell unit folded while the cell units are sequentially folded at the connecting portion By inserting a separator between them, a stacked body of cell units in which the separator is interposed is formed, and a stack is formed by applying a compressive force thereto. And the extent, is made of.

  The production method of the present invention was achieved by injection-molding a gasket on the outer periphery of a membrane electrode assembly (MEA or MEGA) for each single cell and then forming separators on both sides of the membrane electrode assembly to form a single cell. Reexamine the conventional manufacturing method of stacking a predetermined number of single cells and stacking them, forming gaskets formed on the outer periphery of each membrane electrode assembly with adjacent single cells, and folding each other between single cells The present invention relates to a manufacturing method that can significantly increase the manufacturing efficiency of a fuel cell stack by inserting a separator into the battery.

  Here, at the end of the gasket formed at the periphery of the membrane electrode assembly of each single cell, a connecting portion continuous with the gasket of the adjacent single cell is formed by injection molding of this gasket. That is, the connecting portion is injection-molded integrally with the gasket using the same material as the gasket.

  Since the bending process is finally performed in the connecting part, the thickness of the connecting part is preferably smaller than the thickness of the gasket. Further, the thickness of the bent part in the connecting part is preferably the connecting part. The folding line may be formed by being formed thinner than other portions.

  Here, the molding material for the seal gasket and the connecting portion is not particularly limited as long as it is an insulating resin material. Examples thereof include silicone rubber, butyl rubber, and fluororubber.

  In the first step, a cell unit is manufactured by forming a gasket on the periphery of the membrane electrode assembly by injection molding for each single cell, and the gaskets of each cell unit are made of the same material as the gasket. The intermediates of the fuel cell stack are manufactured by connecting the parts. Here, for each adjacent single cell, the intermediate body may be manufactured so that the anode side catalyst layer and the cathode side catalyst layer of the membrane electrode assembly are turned upside down.

  Further, in this first step, a string material is arranged at the gasket molding location prior to the injection molding, and a string material continuous in the gasket is provided in the longitudinal direction of the gasket of each continuous cell unit. It is more preferable that the manufacturing method is buried.

  This string material has flexibility, for example, is made of a thermosetting or thermoplastic resin having a melting temperature higher than that of the resin to be injection-molded. When the injection resin is rubber, the melting temperature is It is preferable to be formed from a resin material having a melting temperature of about 130 ° C. or higher. For example, this string material is wound around a bobbin, and at the time of injection molding for one cell unit, the string material is pulled out from the bobbin and placed in a mold, and then injection molding is performed to cure the injection resin. Waiting for the string material to be buried in the gasket.

  Next, in the injection molding of the adjacent cell unit to be post-processed, the previously formed cell unit is moved, the string material coming out of the cell unit is arranged in the molding die, and injection molding is similarly performed. I will do it.

  By repeating this, string members that are continuous in the longitudinal direction are embedded in a predetermined number of cell units connected to each other at the gasket side connecting portions. That is, the string member extends between the cell units in a posture embedded in the gasket and the connecting portion of each cell unit. For example, in the case where cell units having a gasket having a rectangular shape in plan view are continuous, the string material is provided in a single line at opposite positions across the membrane electrode assembly over the longitudinal direction of the continuous cell units. However, a form in which two strips of string material are arranged may be used.

  The following effects can be expected by continuously burying the string material in the gasket of each cell unit. One of the problems is that the connecting member thinner than the gasket is reinforced by the string member, so that it is possible to solve the problem that the connecting portion breaks when transporting continuously connected cell units. As another one, when the cell unit is removed from the mold after injection molding, the cell unit attached to the cavity surface can be easily peeled and removed by picking the string material portion. The separator here is a separator having a gas flow path formed on one side thereof and a cooling water flow path formed on the other side, or a three-layer structure having a dimple forming the cooling water flow path therein. And a gas flow path unit (so-called flat type module cell separator) made of expanded metal abutted on one side thereof.

  According to the first step described above, continuous cell units are formed at the connecting portion. After the molds are removed, the cell units are sequentially folded back, and a separator is inserted between the folded cell units. As a result, a stack of cell units with separators interposed therebetween is formed. End plates and tension plates are arranged on both sides of the cell stack, and a desired compression force is applied to the stack to stack the fuel. A battery is manufactured (second step).

  The gas and cooling water manifolds formed on the gasket may be formed at a time during injection molding using a molding die having a cavity provided with manifold forming projections. Further, after forming a continuous body (intermediate body) of cell units, a method of sequentially punching at appropriate positions of each manifold may be used. Further, a manifold that penetrates the stacked body after forming a stacked body of single cells may be used. A method of punching at once may be used.

  According to the manufacturing method of the present invention described above, as compared with the conventional manufacturing method in which a gasket is injection-molded around the periphery of the membrane electrode assembly for each single cell, and these are stacked while being positioned with high accuracy to form a stack. By simply bending the connecting part, it is possible to position the adjacent single cells with high accuracy. By stacking the cell units one after another at the connecting part, the separator is inserted into the folded part to make the stack production efficiency. Is significantly improved.

  Further, the manufacturing method described above can be carried out using one or more molds composed of a movable mold and a fixed mold, and a molding apparatus composed of two molds (a first mold and a second mold) is provided. When used, for example, a continuous cell unit connected at the connecting portion of the gasket can be formed while sequentially switching two molds according to an injection molding process, a mold opening process, and a demolding process. .

  When using a molding apparatus comprising two molds, both molds are provided with a gasket cavity and two communication holes communicating with the two side surfaces (outer surfaces) of the mold. The molds are connected in a posture in which the mold communication holes communicate with each other. When molding the connecting portion of the resin material described above, resin leakage is prevented by closing the communication hole on the side where the connecting portion is not formed in both molds with an appropriate closing means. The closing means is provided at an intermediate position (for example, the central portion) of the communication hole.

  An example of a molding method using this molding apparatus will be described. First, the two communicating holes of the first molding die are both closed by the closing means, and injection molding is performed in this posture to form the first cell unit in which the gasket is molded on the outer periphery of the membrane electrode assembly. To do. In this first cell unit, since the injection resin flows to the middle position of both communication holes (the position closed by the closing means), the protruding portions extending outward are simultaneously formed on both sides of the molded gasket. Has been.

  Next, both the molds are connected in a posture in which the one communication hole of the first mold and the one communication hole of the second mold are connected, and the first and second molds communicate with each other. The hole is not closed, the communication hole on the other side of both molds is closed, and the membrane electrode assembly is placed in the cavity, and then injection molding is performed in the second mold. At this stage, the injection resin in the second molding die flows to the middle position of the communication hole of the first molding die through the communication hole of the second molding die (at the tip, the first molding die As a result, a continuous cured resin body is formed between the two communication holes that communicate between the two molds. This continuous cured resin body serves as the connecting portion described above. At this stage, the first cell unit is molded in the first mold and the second cell unit is molded in the second mold, and both cell units are connected by the connecting portion. Yes.

  Next, the first mold is opened to remove the first cell unit, the first mold is connected to the other end of the second mold, and the two communication holes are communicated as described above. Injection molding is performed in the first mold in a posture in which the other communication hole of the first mold is closed at an intermediate position. At this stage, the first cell unit that has already been removed, the second cell unit in the second mold, and the third cell unit in the first mold are respectively connected to the connecting portion. Molded in a connected posture.

  By repeating the above steps as many times as the number of stacked layers, an intermediate body composed of a predetermined number of cell units connected at the connecting portion can be formed.

  When one mold is used, two or more gasket cavities for accommodating two or more membrane electrode assemblies (MEGA) and molding a gasket on the side thereof are connected to each other. A molding die having a cavity communicating with a communication part cavity for molding the communication part by injection molding is prepared. For example, a molding die having a cavity including four cavities for connecting portions that connect five gasket cavities and adjacent gasket cavities can be used.

  At the time of injection molding, the MEGA is accommodated in the gasket cavity while alternately switching the anode side and cathode side of the adjacent MEGA, and the mold is closed in this posture, and injection molding is performed, so that a gasket is placed on the periphery of each of the plurality of MEGAs. In addition to being molded (a plurality of cell units are molded), it is possible to mold an intermediate body in which gaskets of adjacent cell units are connected by a connecting portion.

  In addition, a fuel cell according to the present invention is a fuel cell in which unit cells each composed of a membrane electrode assembly, a gasket formed at the periphery thereof, and a separator sandwiching the electrode body are stacked. In addition, one end of the gaskets of both adjacent single cells is connected by a resin connecting part made of the same material as the gasket, and a stack is formed in a posture in which the gaskets of each single cell are continuous in a meandering manner. It is what has been.

  This fuel cell is a fuel cell manufactured by the above-described manufacturing method, and on both sides of the fuel cell stack, the end portion of the separator surrounded by the connecting portion of the resin material and the outside without being surrounded by the connecting portion. Thus, the end portions of the separator that are opened at the end are alternately formed. In the place surrounded by the connecting part, the insulation of the separator is secured by the connecting part, and in the part opened to the outside, a space is formed at the bent part of the upper and lower connecting parts adjacent to the air gap. Thus, insulation is ensured by this air gap. In addition, the conventional fuel cell stack is one in which a sealing material is finally attached to ensure the insulation of the end portion of the separator, but in the fuel cell made by the manufacturing method of the present invention, As described above, as a result of the insulation being secured by the connecting portion of the resin material at the end of the separator or the air gap formed thereby, it is possible to eliminate the need for sticking of the sealing material.

  As can be understood from the above description, according to the method of manufacturing a fuel cell of the present invention, cell units composed of a membrane electrode assembly and a gasket constituting a single cell are connected by a connecting portion of the same material as the gasket. In this method, the separators are inserted between the folded cell units while the cell units are sequentially folded at the connecting portion. The production efficiency until stacking several single cells is remarkably improved, and as a result, the production efficiency of the fuel cell can be remarkably increased as compared with the conventional production method. Further, according to the fuel cell of the present invention, the seal gasket on the periphery of the membrane electrode assembly is continuous in a meandering manner through the connecting portion, so that the insulating property on the periphery of the separator is secured by the connecting portion and the air gap. can do.

  Embodiments of the present invention will be described below with reference to the drawings. In the production method of the present invention, it is not always necessary to use the molding apparatus in the illustrated example, and at least gaskets of both adjacent cell units are connected by a connecting portion that is molded at the same time during injection molding. The apparatus to be used is not particularly limited as long as the connecting portion is folded and the separator is inserted into the folded portion.

  FIG. 1 is a longitudinal sectional view showing a membrane electrode assembly constituting a cell unit. This membrane electrode assembly (MEGA 10A) is formed of an MEA 10 composed of an electrolyte membrane 11, a cathode electrode layer 12 and an anode electrode layer 13 sandwiching the electrolyte membrane 11, and gas diffusion layers 14 and 15 sandwiching the MEA 10. .

  The electrolyte membrane 11 is a fluorine ion exchange membrane having a sulfonic acid group or a carbonyl group, a non-fluorine polymer such as a substituted phenylene oxide, a sulfonated polyaryletherketone, a sulfonated polyarylethersulfone, or a sulfonated phenylene sulfide. Formed from. The electrode layers 12 and 13 are made of a porous material in which a catalyst made of platinum or an alloy thereof is supported on carbon or the like, and the gas diffusion layers 14 and 15 are made of a gas permeable material such as carbon paper or carbon cloth. It is formed.

  FIG. 2 is a longitudinal sectional view for explaining an embodiment of a molding apparatus used in carrying out the manufacturing method of the present invention.

  The molding apparatus 1000 is roughly composed of two molding dies (first molding die 100 and second molding die 200) and a cord material supply mechanism 60 for providing the cord material T in the cavity C thereof. It is configured. The first molding die 100 and the second molding die 200 are used in such a manner that the communication holes C3 and C4 that communicate with both cavities C and C and communicate with the outside communicate with each other, and one side ends of both are connected. Is done.

  The basic configuration of both the first mold 100 and the second mold 200 is the same. For example, taking the second mold 200 and explaining its configuration, the fixed mold 30 and the movable mold 20 can form a mold closing posture and a mold closing posture as shown in the figure. In addition, the injection hole 23 is opened, and in the mold closing position, the electrode body accommodating cavity C1 and the gasket cavity C2 on the side thereof are formed (the cavity C is composed of the electrode body accommodating cavity C1 and the gasket cavity C2). The gasket cavity C2 has two communication holes C3 and C4 that communicate with the cavity C2 and face the outer surface of the mold.

  Furthermore, the movable mold 20 is provided with receiving grooves 21 and 22 communicating with the communication holes C3 and C4. The receiving holes 21 and 22 close or release the communication holes C3 and C4. For this purpose, cylinder mechanisms 41, 42 for closing and closing bodies 51, 52 for actually closing the communication holes C3, C4 using these as power sources are accommodated. In FIG. 2, both closing bodies 51 and 52 in the second mold 200 show a state where the communication holes C3 and C4 are both closed.

  The gasket cavity C2 is formed with a rib cavity C2 ′ protruding upward and downward, and separators are arranged on both sides of the cell unit composed of the molded product MEGA 10A and the gasket G, and finally stacked. In this case, the ribs surrounding the manifold are crushed by the separator to ensure the sealing performance of gas and cooling water.

  Each molding die is sequentially filled with an injection resin, and a gasket is formed on the periphery of the MEGA 10A having a rectangular (or square) plan view, for example. T is provided on both sides of the rectangle. The string material T is formed of a thermosetting and thermoplastic resin having a melting temperature higher than that of the injection resin, and has heat resistance at the time of injection molding and flexibility when the cell units are bent. Is.

  FIG. 3 is a diagram for explaining the operation of the cylinder mechanism. For example, when the communication hole C3 is set in a non-blocking state (communication state), as shown in FIG. 3a, the piston in the cylinder mechanism 41 is set in a non-extending state to accommodate the blocking body 51 attached to the tip thereof. It completely accommodates in the groove | channel 21, and makes the communicating hole C3 a communication state.

  On the other hand, when the communication hole C3 is in the closed state, as shown in FIG. 3b, the piston is extended by the operation of the cylinder mechanism 41 (X1 direction in the figure), and the closed body 51 attached to the tip of the piston is attached to the closed body 51. Thus, the communication hole C3 is completely closed.

  Both cylinder mechanisms 41 and 42 in the respective separators 100 and 200 are injection-molded with the relative connection relationship between the separators 100 and 200 (whether the separator 100 is on the right side or the left side in the drawing). Depending on which mold is used, each cylinder mechanism 41, 42 automatically operates to form a desired closed state or non-closed state of the communication holes C3, C4. The personal computer 200 is connected to a personal computer (not shown) by wire or wirelessly, and the closing and non-blocking operations of both are automatically controlled by a control means built in the personal computer and a CPU for operating the control means. .

  Next, a method for manufacturing a fuel cell using this molding apparatus 1000 will be described with reference to FIGS.

  First, as shown in FIG. 4, both molds 100, 200 are connected in a posture in which the communication hole C <b> 4 of the first mold 100 and the communication hole C <b> 3 of the second mold 200 communicate with each other.

  Next, the communication hole C4 in the first mold 100 is closed by the closing body 52, and the communication hole C4 in the second mold 200 is also closed by the closing body 52. In this posture, the second mold 200 is closed. The MEGA 10A is transferred into the cavity C1, and the injection resin R is filled into the cavity C2 of the second mold 200 (in the X2 direction in the figure), and injection molding is performed. The cross section shown in the figure is a cross section cut at a location where the manifold is formed, and two gasket cavities C2 and C2 communicate with each other at the outer peripheral portion of the manifold, and the cavity is formed at the periphery of the MEGA 10A. C2 communicates, and therefore, as shown, the injection resin R is filled over the entire area of the cavity C2. Here, examples of the injection resin include silicone rubber, butyl rubber, and fluorine rubber.

  In the second mold 200, the injection resin filled in the cavity C2 is thermally cured, whereby a gasket is formed on the periphery of the MEGA 10A. In the illustrated example, a manifold is formed simultaneously with the gasket formation.

  Next, as shown in FIG. 5, injection molding is also performed in the first mold 100. At the time of this injection molding, the cylinder mechanism 42 in the first mold 100 is operated to store the closing body 52 that has closed the cavity C4 in the storage groove 22, and the cavity C4 and the cavity in the second mold 200 are stored. Communicate with C3.

  On the other hand, the other cavity C3 in the first mold 100 is closed by the closing body 51. In this posture, the MEGA 10A is transferred into the cavity C1 of the first mold 100, and the first mold 100 is moved. The injection resin R is filled into the cavity C2 of the mold 100 (in the X3 direction in the figure) and injection molding is performed. Here, the anode side (or cathode side) of the MEGA 10A placed in the first mold 100 and the anode side (or cathode side) of the MEGA 10A placed in the second mold 200 are vertically As described later, when both cell units are folded back at the connecting portion, one anode side electrode and the other cathode side electrode are adjacent to each other via a separator. The posture to do can be formed.

  Next, as shown in FIG. 6, the second molding die 200 that has been injection-molded first is opened to provide a gasket having a manifold M and an endless rib P on the periphery of the MEGA 10 </ b> A. The cell unit CU having G is demolded.

  In this demolding, the demolding operation is facilitated by picking the string material embedded in the gasket G and peeling off the gasket G adhering to the cavity surface.

  This cell unit CU and a separate cell unit CU still accommodated in the first mold 100 are connected by a connecting portion Q formed in the connected cavities C3 and C4.

  The second mold 200 that has been opened is similarly connected on the other side of the first mold 100, and its cavity C 4 communicates with the cavity C 3 of the first mold 100. The injection molding is performed in a posture in which the cavity C3 is closed (X4 direction in the figure).

  By sequentially repeating the above steps, as shown in FIG. 7, a molded product (intermediate body) in which a predetermined number of cell units CU,... Are continuously connected via the connecting portion Q is formed. In this continuous molding, the continuous string material is sequentially sent out from the string material supply mechanism 60, and the length of the intermediate body is placed inside the gasket G and the connecting portion Q of each cell unit CU forming the intermediate body. A string member extending in the direction is buried.

  As shown in the figure, the connecting portion Q that connects the cell units CU is bent, and the expanded metal EM serving as the separator SP and the gas flow path layer is interposed between the bent portions (Y direction in the figure), and this is repeated. Thus, a cell stack ST including a predetermined number of cell units CU and a corresponding number of separators and expanded metal is formed. In addition, the string material is embed | buried in the attitude | position which followed the longitudinal direction in the gasket G and the connection part Q, and the fracture | rupture in the connection part Q at the time of bending cell units CU is prevented effectively. In addition, the thickness of the connecting portion Q is extremely thin with respect to the thickness of the gasket G, and the bending process is easily performed. It should be noted that folding accuracy (positioning accuracy of the cell unit after folding) can be further improved by further forming the folding portion (folding line) in the connecting portion Q as a thin layer.

  Here, the intervening separator SP may have a form in which a flow path for cooling water is formed on one side and a gas flow path is formed on the other side, or three layers for a flat type module. It may be in the form of a structure.

  For example, in the case of a three-layer structure separator, a face material that defines a cell between adjacent single cells, a separate face material on the MEGA side facing this, and an intermediate layer between these two face materials And a resin material spacer formed in a frame shape (endless shape) along the outer peripheral contour of each face material (not shown). The face material is formed of a gas-impermeable dense carbon material, dense graphite material, or the like, and a plurality of projections (dimples) (not shown) are provided on the side surface of the one face material facing the other face material. When the projection has a height corresponding to the thickness of the spacer, when the three-layer structure is formed, the tip of the projection comes into contact with the side surface of the face material, and turbulently flows between the projections. A flow path of the flowing cooling water is formed.

  FIG. 8 is a longitudinal sectional view illustrating a separate mold. The mold 300 shown in the drawing is a mold that forms three connecting portions that connect four cell units and adjacent cell units at once. In the mold 300, a cavity C composed of an electrode body accommodating cavity C1 and a gasket cavity C2 is connected by a communication hole C5 to form an entire cavity. In the adjacent electrode body accommodating cavities C1 and C1, four MEGAs are accommodated in the respective cavities C1 in an attitude in which the anode side and the cathode side of the MEGA are alternately arranged, and the molds are closed and injection molding is performed. A gasket is formed around each of the four cell units, and an intermediate body in which the gaskets are connected to each other at the connecting portion can be formed at a time. In the illustrated example, the mold 300 includes four cavities C1. However, the number of cavities C1 is not limited to the illustrated example, and any number of groups such as two, ten, and thirty can be used. The provided mold can be used.

  FIG. 9 is a longitudinal sectional view showing a part of the cell stack ST, and shows a state before stacking (giving compressive force).

  From the same figure, each cell unit CU is defined as an adjacent cell unit CU by a separator SP, and each cell unit CU has a structure in which both gaskets G are connected by a connecting portion Q and are continuous in a meandering manner. Presents.

  Further, in this stacking posture, the separator SP and the expanded metal EM have a structure in which one end of the separator SP and the expanded metal EM is alternately accommodated in the stacking direction and an open area A2 that is not accommodated in the connecting portion Q. It has become.

  In the accommodation area A1, the insulating property when the fuel cell stack is formed is ensured by the connecting portion Q in which one end of the separator SP and the expanded metal EM is made of injection resin.

  On the other hand, in the open area A2, the air gap AG is formed by the connecting portions Q, Q existing on the upper and lower sides projecting laterally, thereby ensuring the insulation when the fuel cell stack is formed.

  In an actual fuel cell, a single cell consisting of a cell unit and a separator, shown in the figure, is stacked in accordance with the desired power generation amount, with an end plate, tension plate, etc. on the outermost side, and a compressive force between the tension plates at both ends. Is added to form a fuel cell stack.

  A fuel cell system mounted on an electric vehicle or the like includes this fuel cell, various tanks for storing hydrogen gas and air, a blower for supplying these gases to the fuel cell, a radiator for cooling the fuel cell, a fuel The battery is generally composed of a battery that stores electric power generated by the battery, a drive motor that is driven by the electric power, and the like.

  According to the fuel cell manufacturing method of the present invention described above, the cell units are formed continuously, and further, when the cell units are bent at the connecting portion Q, the stacking posture of the cell units is accurately formed. Therefore, the manufacturing efficiency is remarkably improved as compared with the conventional manufacturing method.

  Further, at the same time as the fuel cell stack is formed, as shown in FIG. 8, since the separator periphery is secured by the connecting portion and the air gap, the step of attaching the insulating sheet can be omitted.

  The embodiment of the present invention has been described in detail with reference to the drawings. However, the specific configuration is not limited to this embodiment, and there are design changes and the like without departing from the gist of the present invention. They are also included in the present invention.

It is the longitudinal cross-sectional view explaining the membrane electrode assembly. It is the longitudinal cross-sectional view explaining the shaping | molding apparatus. It is the figure explaining operation | movement of the obstruction | occlusion cylinder mechanism, Comprising: (a) is the figure which showed the state which the communicating hole connected, (b) is the figure which showed the state by which the communicating hole was obstruct | occluded. It is the flowchart explaining the manufacturing method of the fuel cell. FIG. 5 is a flowchart for explaining a method of manufacturing a fuel cell following FIG. 4. FIG. 6 is a flowchart illustrating a method for manufacturing a fuel cell, following FIG. 5. FIG. 7 is a flowchart illustrating a method for manufacturing a fuel cell, following FIG. 6. It is the longitudinal cross-sectional view explaining the separate shaping | molding die. It is the longitudinal cross-sectional view which showed a part of fuel cell stack before a cell unit is laminated | stacked and stacked.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 ... MEA (membrane electrode assembly), 10A ... MEGA (membrane electrode assembly), 11 ... Electrolyte membrane, 12, 13 ... Catalyst layer, 14, 15 ... GDL (gas diffusion layer), 20, 20A ... Movable type, 21, 22, receiving grooves, 23, injection holes, 30, 30 A, fixed mold, 41, 42, closed cylinder mechanism, 51, 52, closed body, 60, string material supply mechanism, 100, first mold 200, 2nd mold, 300 ... Mold, 1000 ... Molding device, C ... Cavity, C1 ... Electrode body containing cavity, C2 ... Gasket cavity, C2 '... Rib cavity, C3, C4, C5 ... Communication hole, T: String material, R: Silicone rubber (injection resin), G ... Gasket, P ... Rib, M ... Manifold, Q ... Connection part, CU ... Cell unit, SP ... Separator, ST ... Stack, AG ... Air gap, A1 ... Contents area, A2 ... open area

Claims (5)

A gasket and a connecting portion extending from one side of the gasket to the outside thereof are integrally formed on the periphery of the membrane electrode assembly by injection molding, and the other side is connected to the connecting portion by injection molding on the periphery of the separate membrane electrode assembly. The gasket is molded so that the sides are connected, and the connecting portion extending from one side of the gasket to the outside thereof is integrally molded, and this is repeated, so that the cell unit comprising the membrane electrode assembly and the peripheral gasket is connected to the cell unit. A first step of forming intermediates connected at the part;
A separator is inserted between the folded cell units while the cell units are sequentially folded at the connecting portion, thereby forming a stack of cell units with the separator interposed therebetween, and applying a compressive force to the stack to stack. And a second step of forming a fuel cell.   The method of manufacturing a fuel cell according to claim 1, wherein a thickness of the connecting portion is smaller than a thickness of the gasket.   In the first step, a string material is disposed at a gasket molding location prior to injection molding, and a continuous string material is embedded in the gasket along the longitudinal direction of the gasket of each continuous cell unit. The method for producing a fuel cell according to claim 1 or 2.   The fuel cell manufacturing method according to claim 1, wherein a manifold or a manifold and a seal protrusion surrounding the manifold are formed during injection molding in the first step. An electrode body comprising a membrane electrode assembly and a gasket formed on the periphery thereof;
A separator that sandwiches the electrode body, and a fuel cell in which single cells are stacked,
One end of the gaskets of both adjacent single cells are connected by a resin connecting portion made of the same material as the gasket, and a stack is formed in a posture in which the gaskets of each single cell are continuous in a meandering manner. Fuel cell.

Images