JP4887597B2 - Solid polymer fuel cell, gas diffusion layer member and method for producing the same - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a polymer electrolyte fuel cell, a gas diffusion layer member, and a method for producing the same.
[0002]
[Prior art]
In recent years, a polymer electrolyte fuel cell using an ion conductive solid polymer membrane as an electrolyte has been developed and attracts attention as a stationary power source for home use, a power source for an electric vehicle, or a power source for a small portable device. Usually, a polymer electrolyte fuel cell has a structure in which a high voltage is obtained by connecting a plurality of single cells in series because the electromotive force generated by a pair of electrodes (single cells) is small.
[0003]
As one of the structures for sequentially connecting a plurality of unit cells, there is a so-called stack type fuel cell in which unit cells are stacked in the thickness direction (see, for example, Patent Document 1).
[0004]
[Patent Document 1]
JP-A-8-78028
[0005]
[Problems to be solved by the invention]
In such a stack type fuel cell, a separator plate is provided between the stacked single cells. This separator plate requires a groove for supplying fuel (hydrogen) and air (oxygen) to the gas diffusion layer. In order to provide this groove, the separator plate needs to have a certain thickness. For this reason, there exists a problem that size reduction and weight reduction of a fuel cell are prevented by the volume and weight of a separator plate.
[0006]
Furthermore, since a porous body such as a carbon sheet constituting the gas diffusion layer has a property that it has low strength and is easily deformed, there is a problem that it is difficult to handle and the manufacturing of the fuel cell is difficult.
[0007]
The present invention has been made in view of the above problems, and an object thereof is to realize a small and lightweight fuel cell excellent in productivity.
[0008]
[Means for Solving the Problems]
  In order to solve the above problems, the present invention provides a gas diffusion layer member used in a polymer electrolyte fuel cell as follows.
  That is, the gas diffusion layer member of the present invention has a separator plate and a sheet-like gas diffusion electrode made of a conductive porous body having a three-dimensional network structure,A first flow path for allowing the first fluid to pass therethrough and a second flow path for allowing the second fluid to pass;A gas diffusion electrode is disposed on the surface of the separator plate. Then, the separator plate is formed with a third flow path for allowing the fluid to pass through the gas diffusion electrode so as to face the gas diffusion electrode, and a resin frame covering the periphery of the gas diffusion electrode and the separator plate, It is characterized by being provided integrally.
[0009]
There are two types of typical fuels used in polymer electrolyte fuel cells: hydrogen gas and aqueous methanol solution. When methanol aqueous solution is used, the fuel flowing through the conductive porous body is liquid. The part is conventionally called a gas diffusion layer. Here, including the case where liquid fuel is used, it is called a gas diffusion layer in accordance with conventional usage, and is not limited to gas fuel.
In addition, the resin material forming the resin frame is not limited to a so-called synthetic resin, and includes a rubber material such as an elastomer.
[0010]
  According to the gas diffusion layer member of the present invention, since the gas diffusion electrode serves as both the gas diffusion layer and the electrode, the number of parts can be reduced. In addition, since it is integrated with the resin frame, it is easy to handle, and the gas diffusion electrode is prevented from being damaged when manufacturing the fuel cell, so that a fuel cell with high productivity can be realized. Moreover, since the side surface of the gas diffusion electrode is covered with the resin frame, the open pores opened on the side surface are sealed, and fuel leakage can be effectively prevented. Furthermore, since a fluid (fuel, air, etc.) flow path is formed in the gas diffusion electrode of the conductive porous body, a thin separator plate can be used, and the fuel cell can be reduced in size and weight.Moreover, since the member for gas diffusion layers of this invention is provided with the 1st flow path for allowing the 1st fluid to pass through, and the 2nd flow path for allowing the 2nd fluid to pass through, this structure Thus, different fluids (fuel and air) can be passed from the outside of the gas diffusion layer member to each gas diffusion electrode to cause an electrode reaction.In the gas diffusion layer member of the present invention, the third flow path is formed in the separator plate as well as the flow path in the gas diffusion electrode, so that the flow path in the gas diffusion electrode is in the thickness direction. Thus, the fluid can be smoothly supplied without increasing the supply pressure. In addition, when the gas diffusion electrode has a low air permeability and it is difficult to supply or discharge fuel or oxygen only with the continuous air holes inside the porous body, the third flow path such as a groove formed on the surface of the separator plate is provided. It can be used to smoothly flow fluid, and the power generation amount in the fuel cell can be stabilized.
[0011]
  Further, the gas diffusion layer member of the present inventionInIt is preferable that the 1st and 2nd flow path is formed in the resin frame. Furthermore, it is more preferable that the first and second flow paths are provided through the resin frame connected to the gas diffusion electrode.
[0012]
ThisThese first and second flow paths are provided in various shapes, but if the formation location is a resin frame, it is easy to process and is generally more costly than being processed and formed into an electrically conductive porous body. It is advantageous in that the surface of the porous body related to the conductive efficiency of the electrode can be used effectively. Further, by providing the first and second flow paths through the resin frame, a flow path communicating in the thickness direction can be easily formed when a gas diffusion layer member is laminated to form a fuel cell. Thus, a fuel cell having a simple structure and high productivity can be realized.
[0013]
  further,The third flow path has a groove shape and is formed on both sides of the separator plate. The third flow path is formed on one side of the both surfaces and the third flow path is formed on the other side. Extend so as to be perpendicular to each otherIs preferable.
[0014]
The gas diffusion layer member of the present invention can be manufactured by insert molding in which a resin material is injected using a conductive porous body and a separator plate as insert parts.
By adopting insert molding, the molten resin enters and solidifies into pores that open on the surface of the conductive porous body at the portion where the conductive porous body (gas diffusion electrode) and the resin frame are connected. Due to the effect, the conductive porous body and the resin frame are firmly connected, and a gas diffusion layer member having high strength can be manufactured.
[0015]
  A polymer electrolyte fuel cell according to the present invention is as defined in claim 1.4A plurality of gas diffusion layer members are stacked in the thickness direction, an electrolyte layer made of a solid polymer electrolyte is disposed between the gas diffusion layer members, and the electrolyte layer and each gas diffusion layer member A catalyst layer provided at the interface with the gas diffusion electrode is provided.
[0016]
With this configuration, the polymer electrolyte fuel cell of the present invention can form a single cell with a simple component configuration in which an electrolyte layer and a catalyst layer are simply disposed between two gas diffusion layer members. . Further, if a plurality of gas diffusion layer members are stacked and an electrolyte layer is disposed between each member, a stack type fuel cell in which a plurality of single cells are stacked can be easily formed.
[0017]
DETAILED DESCRIPTION OF THE INVENTION
  Hereinafter, embodiments of the present inventionReference examples on which to assumeWill be described with reference to the drawings.
  Figure 1 shows the bookReference exampleThe main part of the polymer electrolyte fuel cell using the gas diffusion layer members 10, 50, 60 is shown. This fuel cell has a so-called stack type structure in which four sets of single cells 30 are stacked, and an electrode reaction is caused by supplying fuel (for example, aqueous methanol solution) and air as an oxidant. Electric power can be generated.
[0018]
As shown in FIG. 1, the gas diffusion layer member 10 has a structure in which gas diffusion electrodes 11 and 11 and a separator plate 12 are laminated in the thickness direction, and a resin frame 13 covering the periphery in the surface direction is integrally formed. It has become. As shown in FIGS. 1 and 2, the gas diffusion layer member 10 includes first flow paths 10a and 10b for allowing the first fluid (fuel) to pass therethrough, and a second fluid (air). The second flow paths 10c and 10d for allowing the resin to pass therethrough are provided through the resin frame 13.
2 is a view taken along the line II-II in FIG. 1, and FIG. 1 is a cross-sectional view taken along the line II in FIG.
[0019]
The gas diffusion electrode 11 is a thin plate made of a conductive porous body having a three-dimensional network structure, and has a characteristic of being light and having a large surface area because it has air permeability due to pores opened in the surface communicating with each direction. have. This gas diffusion electrode 11 has a tab-shaped connection portion 11b, 11b for connecting to one of the first flow paths 10a, 10b and the second flow paths 10c, 10d at the end of a substantially rectangular electrode body 11a. It is the shape provided in.
[0020]
The gas diffusion electrodes 11 and 11 are arranged so that the electrode main body 11a overlaps and the connection portions 11b and 11b do not overlap each other. One of the first flow paths 10a and 10b and the second flow paths 10c and 10d penetrating the resin frame 13 is connected to the connection portion 11b. That is, different flow paths are connected to the gas diffusion electrode 11 at two connection portions 11b provided on the electrode body 11a.
[0021]
  Therefore, the fuel supplied to the first flow path 10a passes through the continuous vent hole of the gas diffusion electrode 11 and flows out to the first flow path 10b. In addition, the air supplied to the second flow path 10c passes through the continuous air holes of the gas diffusion electrode 11, and the second2It flows out to the channel 10d.
[0022]
The separator plate 12 does not pass air or fuel gas or liquid, and has conductivity, for example, a carbon plate or a corrosion-resistant metal plate, and more than an H-shape that overlaps at least the gas diffusion electrodes 11 and 11. Largely formed. And by arrange | positioning between the gas diffusion electrodes 11 and 11, the single cell 30 which each gas diffusion electrode 11 and 11 forms as shown in FIG. 1, preventing the distribution | circulation of the fluid between each electrode, as shown in FIG. Connected in series.
The gas diffusion electrode 11 and the separator plate 12 can be tightly fixed by diffusion bonding.
[0023]
The resin frame 13 is integrally provided so as to cover the periphery of the gas diffusion electrode 11, the separator plate 12, and the gas diffusion electrode 11 stacked in the thickness direction. It is the same surface connected to the surface. The resin frame 13 is formed in a substantially rectangular parallelepiped in which the gas diffusion electrode 11 and the separator plate 12 are embedded, and bolt insertion holes 10e penetrating in the thickness direction are provided at the four corners. Tie bolts for fixing a plurality of gas diffusion layer members 10 and electrolyte layers 20 when they are laminated in multiple layers can be inserted into the bolt insertion holes 10e.
[0024]
Further, gas diffusion layer members 50 and 60 are disposed on both end faces of the fuel cell, respectively.
As shown in FIGS. 1 and 3, the gas diffusion layer member 50 has a structure in which a gas diffusion electrode 51 and a separator plate 52 are laminated in the thickness direction, and a resin frame 53 covering the periphery in the surface direction is integrally formed. It has become. The gas diffusion layer member 50 has first flow paths 50a and 50b for allowing the first fluid (fuel) to pass through the gas diffusion electrode 51 and a second fluid (air). Second flow paths 50 c and 50 d are provided through the resin frame 53.
[0025]
The gas diffusion electrode 51 is a thin plate made of a conductive porous body having a three-dimensional network structure like the gas diffusion electrode 11, and has air permeability because pores opened on the surface communicate with each direction. The surface area is large. The gas diffusion electrode 51 has a shape in which connection portions 51b and 51b for connecting to either of the first flow paths 50a and 50b are provided in a tab shape at the end of a substantially rectangular electrode body 51a. Yes.
Therefore, the fuel supplied to the flow path 50a passes through the continuous vent of the gas diffusion electrode 51 and flows out to the flow path 50b.
[0026]
The separator plate 52 does not pass air or fuel gas or liquid as the separator plate 12 and has conductivity, such as a carbon plate or a corrosion-resistant metal plate, and covers at least the surface of the gas diffusion electrode 51. Is also formed large. The fluid is prevented from flowing from the gas diffusion electrode 51 to the outside of the battery by being disposed in contact with the gas diffusion electrode 51.
The gas diffusion electrode 51 and the separator plate 52 can be tightly fixed by diffusion bonding.
[0027]
The resin frame 53 is integrally provided so as to cover the periphery in the surface direction of the gas diffusion electrode 51 and the separator plate 52 stacked in the thickness direction, and one surface thereof is the same surface connected to the surface of the gas diffusion electrode 51. Yes. The resin frame 53 is formed in a substantially rectangular parallelepiped in which the gas diffusion electrode 51 and the separator plate 52 are embedded, and bolt insertion holes 50e penetrating in the thickness direction are provided at the four corners. The bolt insertion holes 50e can be inserted with tie bolts for fixing the gas diffusion layer members 10, 50 and the electrolyte layer 20 in multiple layers.
[0028]
Further, as shown in FIGS. 1 and 4, the gas diffusion layer member 60 is formed by laminating a gas diffusion electrode 61 and a separator plate 62 in the thickness direction, and integrally forming a resin frame 63 covering the periphery in the surface direction. It has a structure. The gas diffusion layer member 60 has first flow paths 60a and 60b for allowing the first fluid (fuel) to pass through the gas diffusion electrode 61 and a second fluid (air). Second flow paths 60 c and 60 d are provided through the resin frame 63.
[0029]
The gas diffusion electrode 61 is a thin plate made of a conductive porous body having a three-dimensional network structure like the gas diffusion electrodes 11 and 51, and has air permeability due to pores opening on the surface communicating in each direction. It has the characteristics of being lightweight and having a large surface area. The gas diffusion electrode 61 has a shape in which connection portions 61b and 61b for connecting to the second flow paths 60c and 60d are provided in a tab shape at the end of an approximately rectangular electrode body 61a.
Therefore, the air supplied to the flow path 60c passes through the continuous air holes of the gas diffusion electrode 61 and flows out to the flow path 60d.
[0030]
Like the separator plates 12 and 52, the separator plate 62 does not pass air or fuel gas or liquid, and has conductivity, such as a carbon plate or a corrosion-resistant metal plate, and at least the surface of the gas diffusion electrode 61. It is larger than it covers. The fluid is prevented from flowing from the gas diffusion electrode 61 to the outside of the battery by being disposed in contact with the gas diffusion electrode 61.
The gas diffusion electrode 61 and the separator plate 62 can be closely fixed by diffusion bonding.
[0031]
The resin frame 63 is integrally provided so as to cover the periphery in the surface direction of the gas diffusion electrode 61 and the separator plate 62 stacked in the thickness direction, and one surface thereof is the same surface connected to the surface of the gas diffusion electrode 61. Yes. The resin frame 63 is formed in a substantially rectangular parallelepiped in which the gas diffusion electrode 61 and the separator plate 62 are embedded, and bolt insertion holes 60e penetrating in the thickness direction are provided at the four corners. When the plurality of gas diffusion layer members 10, 50, 60 and the electrolyte layer 20 are laminated in multiple layers, tie bolts for fixing them can be inserted into the bolt insertion hole 60e.
[0032]
In the fuel cell shown in FIG. 1, the electrolyte layer 20 disposed in close contact with the gas diffusion electrodes 11, 51, 61 of the gas diffusion layer members 10, 50, 60 is formed of, for example, a fluororesin polymer electrolyte membrane. Is done. The electrolyte layer 20 has the property of preventing electrons from passing through while the hydrogen ions can move in the film. The electrolyte layer 20 includes the first flow paths 10a, 10b, 50a, 50b, 60a, 60b and the second flow paths 10c, 10d, 50c, 50d, when overlapped with the gas diffusion layer members 10, 50, 60. A through hole 20a communicating with 60c, 60d is formed.
[0033]
  The interface between the electrolyte layer 20 and the gas diffusion electrodes 11, 51, 61 of the gas diffusion layer members 10, 50, 60 (thisReference exampleThen, the catalyst layer 31 is provided on the surface side of the gas diffusion electrodes 11, 51, 61.
  The catalyst layer 31 is formed by applying a polymer electrolyte solution containing carbon particles carrying platinum-based catalyst fine particles to the surfaces of the gas diffusion electrodes 11, 51, 61. The catalyst layer 31 and the electrolyte layer 20 can be tightly fixed by hot pressing. Further, the electrolyte layer 20 and the resin portions 13, 53, 63 of the gas diffusion layer members 10, 50, 60 can be tightly fixed by ultrasonic bonding.
  The catalyst layer 31 only needs to be interposed between the electrolyte layer 20 and the gas diffusion electrodes 11, 51, 61.Reference exampleThen, although provided in the surface part of the gas diffusion electrodes 11, 51, 61, it can also be formed in the surface part of the electrolyte layer 20.
[0034]
In the fuel cell shown in FIG. 1, the gas diffusion layer members 10, 50, 60 described above and the electrolyte layer 20 disposed therebetween are stacked, and gas diffusion is performed by using both sides as shielding plates having no air permeability and conductivity. It has the structure closed with the separator plates 52 and 62 with which the members 50 and 60 for layers were equipped. The gas diffusion layer members 10, 50, 60, which are an integral part of the resin frames 13, 53, 63, are easy to handle and are not easily damaged. Therefore, waste due to damage is less likely to occur, and handling by an automatic machine is easy. A good fuel cell can be realized.
[0035]
In this fuel cell, the fuel-side supply path F formed by connecting the gas diffusion layer members 10, 50, 60 and the electrolyte layer 20 so that the first flow paths 10a, 50a, 60a and the through-holes 20a communicate with each other. A fuel-side discharge passage (not shown) formed by communication between the first flow paths 10b, 50b, 60b and the through hole 20a, and the second flow paths 10c, 50c, 60c and the through hole 20a. The formed air side supply path A and an air side discharge path (not shown) formed by communicating the second flow paths 10d, 50d, 60d and the through hole 20a are formed.
[0036]
In this fuel cell, when fuel (methanol aqueous solution here) is fed from the fuel side supply path F, the fuel is supplied to the gas diffusion electrodes (fuel electrodes) 11 and 51 through the first flow paths 10a, 50a and 60a. While this fuel passes through the gas diffusion electrodes 11 and 51, hydrogen in the fuel is ionized by a catalytic reaction on the interface of the catalyst layer 31, and the remaining fluid (unreacted portions) flows into the first flow paths 10b and 50b. It is discharged from the fuel side discharge path.
[0037]
On the other hand, air is supplied from the air-side supply path A to the gas diffusion electrodes (air electrodes) 11 and 61 facing the fuel electrodes 11 and 51 through the second flow paths 10c, 50c, and 60c. Hydrogen ionized by the fuel electrodes 11 and 51 moves through the electrolyte layer 20 to reach the air electrodes 11 and 61, and reacts with oxygen in the air on the interface of the catalyst layer 31 of the air electrodes 11 and 61 by the electrode reaction. To produce water. This water is discharged from the air-side discharge path through the second flow paths 10d and 60d. Further, residual gas (unreacted part) of the air after the electrode reaction is also discharged from the air side discharge path through the second flow paths 10d and 60d.
[0038]
Electrons generated by the ionization of hydrogen move from the fuel electrode (gas diffusion electrode) 11 to the air electrode (gas diffusion electrode) 11 through the separator plate 12. By this movement of electrons, the fuel cell can generate electric energy with the fuel electrode 51 as an anode and the air electrode 61 as a cathode.
[0039]
By the way, the gas diffusion electrodes 11, 51, 61 are sheet-like members that serve both as a gas diffusion layer and a current collector plate by providing air permeability and conductivity by a three-dimensional network structure in this polymer electrolyte fuel cell. . As the conductive porous body forming the gas diffusion electrodes 11, 51, 61, a carbon porous body such as carbon paper or carbon cloth may be used, but a three-dimensional network having both good gas diffusibility and conductivity. It is desirable to use a metal having a structure, for example, a sheet obtained by sintering metal powder, a metal nonwoven fabric, a laminated mesh, or the like. Especially, the sheet | seat which sintered the metal powder which can adjust porosity and thickness suitably and can use the various raw material metals is more suitable as a conductive porous body of this member for gas diffusion layers.
[0040]
  Furthermore, a foamed metal sintered sheet obtained by mixing a metal powder with a binder and a solvent and kneading it into a foaming slurry by mixing with a foaming agent and sintering it after foam molding can be manufactured to a high porosity. This is more preferable.
  BookReference exampleEmploys a foamed metal sintered sheet in which the porosity and thickness can be adjusted as appropriate, and the raw metal that can be used is also diverse.
[0041]
Here, the manufacturing method of a metal foam sintered sheet is demonstrated with reference to FIG.
The foamed metal sintered sheet is obtained by mixing a metal powder with a binder and a solvent and kneading the mixture to form a foamable slurry S by mixing a foaming agent and sintering after foam molding.
[0042]
The slurry S is a mixture of conductive metal powder, foaming agent (hexane), organic binder (methyl cellulose), solvent (water), and the like. FIG. 5 shows a green sheet manufacturing apparatus 80 for thinly forming the slurry S by the doctor blade method.
[0043]
In the green sheet manufacturing apparatus 80, first, the slurry S is supplied onto the carrier sheet 82 from the hopper 81 in which the slurry S is stored. The carrier sheet 82 is conveyed by a roller 83, and the slurry S on the carrier sheet 82 is extended between the moving carrier sheet 82 and the doctor blade 84, and formed to a required thickness.
[0044]
The formed slurry S is further conveyed by a carrier sheet 82 and sequentially passes through a foaming tank 85 and a heating furnace 86 that perform heat treatment. Since the heat treatment is performed in the high-humidity atmosphere in the foaming tank 85, the foaming agent can be foamed without causing the slurry S to crack. Then, when the slurry S in which cavities are formed by foaming is dried in the heating furnace 86, the green sheet G in a state where the metal powder forming the cavities between the particles is bonded by the organic binder is formed.
[0045]
The green sheet G is removed from the carrier sheet 82, and then degreased and fired in a vacuum furnace (not shown) to remove the organic binder and sinter metal powders to form a three-dimensional network structure. A sintered sheet (conductive porous body) is obtained.
[0046]
A gas diffusion electrode 11 made of a conductive porous body is formed by performing insert molding with the conductive porous body formed in this way cut into a predetermined shape and the separator plates 12, 52, 62 as insert parts. Thus, the gas diffusion layer member 10 including 51, 61, the separator plates 12, 52, 62, and the resin portions 13, 53, 63 can be manufactured.
[0047]
Here, insert molding for producing the gas diffusion layer member 10 will be described with reference to FIG.
First, the conductive porous body (gas diffusion electrodes 11, 11) and the separator plate 12 are integrally fixed by diffusion bonding to form an insert part P. And this insert part P is arrange | positioned in the cavity 72 formed between a pair of template 70,71 shown in FIG. 6, and the molten resin 75 inject | poured through the gate 74 from the runner 73 is filled in the cavity 72. FIG. Thus, the gas diffusion layer member 10 in which the gas diffusion electrode 11 made of a conductive porous body, the separator plate 12 and the resin frame 13 are integrated is formed.
Although the gas diffusion electrode 11 having the catalyst layer 31 formed on the surface portion is used in FIG. 6, the catalyst layer 31 is not necessarily formed on the gas diffusion electrode 11 and is formed on the electrolyte layer 20. Alternatively, when it is provided on the gas diffusion electrode 11, it can be formed after insert molding.
[0048]
The gas diffusion layer members 50 and 60 can also be manufactured by insert molding similar to the above.
That is, the conductive porous body (the gas diffusion electrodes 51 and 61) and the separator plates 52 and 62 are integrally fixed by diffusion bonding and formed as an insert part between the pair of mold plates 70 and 71 shown in FIG. The molten resin 75 disposed in the cavity 72 and injected from the runner 73 through the gate 74 is filled into the cavity 72, whereby the gas diffusion electrodes 51 and 61, separator plates 52 and 62, and the resin frame 53 made of a conductive porous body are filled. , 63 are formed as gas diffusion layer members 50, 60.
[0049]
By forming the resin frames 13, 53, 63 by insert molding as described above, the gas diffusion electrodes 11, 51, 61 and the resin frames 13, 53, 63 are located on the gas diffusion electrodes 11, 51, 61 side. In the pores opened in the part, the molten resin is impregnated to a depth of about 5 μm to 1000 μm, hardened, and firmly joined. The flow paths 10a, 10b, 10c, 10d, 50a, 50b, 50c, 50d, 60a, 60b, 60c, 60d and the bolt insertion holes 10e, 50e, 60e penetrating the resin frame are pin members 76 provided in the mold. Thus, it can be formed at the time of this injection molding.
[0050]
In insert molding, for example, when polypropylene is used as the material of the resin frames 13, 53, 63, the mold is clamped at a molding temperature of 180 ° C. and 80 kN, and a molding pressure of 250 kg / cm.²When injection molding is performed, composite metal porous bodies 10, 50, 60 are obtained.
[0051]
When the gas diffusion layer members 10, 50, 60 are formed by insert molding, the thickness of the cavity 72 (size in the mold opening / closing direction) when the mold is closed is slightly smaller than that of the insert part P, and the mold is closed. When the gas diffusion electrodes 11, 51, 61 are sometimes compressed by 3 to 90% between the mold plates 70, 71, the gas diffusion electrodes 11, 51, 61 are fixed with respect to the cavity 72 and are displaced by the injection resin pressure. Can be prevented, and the flatness of the gas diffusion electrodes 11, 51, 61 can be improved.
[0052]
Further, if the gas diffusion electrodes 11, 51, 61 are too small in pore diameter or porosity, the molten resin cannot enter the pores, so that the anchor effect is insufficient, and the bonding strength with the resin frames 13, 53, 63 is low. There is a risk that it will not be sufficiently obtained and will peel off at the joint. On the other hand, if the pore diameter and the porosity are too large, the strength is insufficient, the resin molding pressure and the compression at the time of resin curing cannot be endured, and the shape is deformed. Therefore, the pore diameter is preferably about 10 μm to 2 mm and the porosity is about 40 to 98%.
On the other hand, the material of the resin material forming the resin frames 13, 53, 63 may be any material that can be injection-molded, such as a thermoplastic resin and an elastomer. Just choose.
[0053]
  In addition, the aboveReference exampleEach component shown in FIG. 1, its shape and combination are examples,In applying to the embodiment of the present invention,Various modifications can be made based on design requirements without departing from the spirit of the present invention. SaidReference exampleThe fuel cell having four sets of single cells has been described, but the present invention is not limited to four sets of single cells, and the gas diffusion layer member 10 and the electrolyte layer 20 may be laminated as necessary. Thus, a high output fuel cell can be obtained.
[0054]
  Also, the aboveReference exampleIn the configuration, fluid such as fuel or air is discharged from each flow path only through the pores of the gas diffusion electrodes 11, 51, 61. However, the porosity of the gas diffusion electrodes 11, 51, 61 is low. If there are few continuous vents, the flow path becomes narrow and long in the surface direction, so there is a risk that it may be difficult to supply fluid.Therefore, in the embodiment of the present invention, while having the same configuration as the reference example described above, as a special configuration other than that,As shown in FIG. 7, a groove shape is formed as the third flow paths 40a and 40b on both surfaces of the separator plate 40, and the fluid flows through the third flow paths 40a and 40b.BySince the flow path in the gas diffusion electrode 11 is short in the thickness direction, the fluid can be smoothly supplied without increasing the supply pressure. In addition, a pump for increasing the fuel supply pressure may be provided.
[0055]
  In addition, the embodimentAnd reference examplesThen, the plurality of single cells 30 are formed by the gas diffusion layer member 10 provided with the gas diffusion electrodes on both sides of the separator, but the gas diffusion layer members 50 and 60 provided with the gas diffusion electrode only on one side are replaced with the separator. It can also be attached to the back.
[0056]
【The invention's effect】
As described above, according to the present invention, there is less risk of fuel leakage due to the reduction of the number of parts and the improvement of handling by realizing a high-strength gas diffusion layer member. A high-performance fuel cell with good characteristics can be realized.
[Brief description of the drawings]
FIG. 1 shows the present invention.Reference example that is the premise of this embodimentIt is sectional drawing which shows the principal part of the fuel cell which concerns on.
FIG. 2 is an arrow view taken along line II-II in FIG.Reference exampleIt is a top view which shows the member for gas diffusion layers which concerns on.
3 is an arrow view taken along line III-III in FIG.Reference exampleIt is a top view which shows the member for gas diffusion layers which concerns on.
FIG. 4 is an arrow view along the line IV-IV in FIG.Reference exampleIt is a top view which shows the member for gas diffusion layers which concerns on.
FIG. 5 is shown in FIGS. 2 to 4SugaIt is a schematic diagram which shows an example of the apparatus which uses the electroconductive porous body used for the member for gas diffusion layers for manufacture.
FIG. 6 is shown in FIGS. 2 to 4SugaIt is a schematic cross section which shows insert molding which manufactures the member for gas diffusion layers.
FIG. 7The fruitIt is a top view which shows the separator board used for the member for gas diffusion layers which concerns on embodiment.
[Explanation of symbols]
  10, 50, 60 Gas diffusion layer member
  10a, 10b, 50a, 50b, 60a, 60b 1st flow path
  10c, 10d, 50c, 50d, 60c, 60d Second flow path
  11, 51, 61 Gas diffusion electrode (conductive porous body)
  12, 40, 52, 62 Separator plate
  13, 53, 63 Resin frame
  40a, 40b 3rd flow path
  20 Electrolyte layer
  30 single cells
  31 catalyst layer

Claims (6)

A gas diffusion layer member having a separator plate and a sheet-like gas diffusion electrode made of a conductive porous body having a three-dimensional network structure in contact with the surface of the separator plate,
The gas diffusion layer member is provided with a first flow path for allowing the first fluid to pass therethrough and a second flow path for allowing the second fluid to pass,
The gas diffusion electrode is disposed on at least one surface of the separator plate;
The separator plate is formed with a third flow path for allowing fluid to pass through the gas diffusion electrode so as to face the gas diffusion electrode,
A member for a gas diffusion layer of a polymer electrolyte fuel cell, wherein a resin frame covering the periphery of the gas diffusion electrode and the separator plate is integrally provided. The member for a gas diffusion layer of a polymer electrolyte fuel cell according to claim 1 , wherein the first and second flow paths are formed in the resin frame. The member for a gas diffusion layer of a polymer electrolyte fuel cell according to claim 2 , wherein the first and second flow paths are connected to the gas diffusion electrode and penetrate the resin frame. The third flow path has a groove shape and is formed on both sides of the separator plate,
A third passage formed in the third flow path and the other surface formed on one surface of the both sides of claims 1 to 3, characterized in that extends so as to be perpendicular to each other The member for gas diffusion layers in any one. The solid polymer, wherein the gas diffusion layer member according to any one of claims 1 to 4 is manufactured by insert molding in which a resin material is injected using the conductive porous body and the separator plate as insert parts. For producing gas diffusion layer member for fuel cell. A plurality of gas diffusion layer members according to any one of claims 1 to 4 are stacked in the thickness direction, and an electrolyte layer made of a solid polymer electrolyte is disposed between the gas diffusion layer members, A solid polymer fuel cell comprising a catalyst layer provided at an interface between an electrolyte layer and the gas diffusion electrode of each gas diffusion layer member.

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