JP2006179216A - Solid polymer fuel cell and its manufacturing method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a solid polymer fuel cell in which a catalyst can be utilized effectively, and in which low-cost can be realized. <P>SOLUTION: In the solid polymer fuel cell that is provided with a membrane/electrode assembly 11 in which catalyst electrodes 3 consisting of catalyst layers 31 and electrode base materials 32 on the catalyst layers 31 are installed on both faces of an electrolyte membrane 1, and with a pair of separators 5 with which the membrane/electrode assembly 11 is pinched and in which grooves 7 for gas passages are formed on the faces opposed to the membrane/electrode assembly 11, at least one catalyst electrode 3 is installed in a region opposed to a region where the groove 7 of the separator 5 is formed. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a polymer electrolyte fuel cell and a method for producing the same.

A fuel cell is a cell in which electrodes are arranged on both sides of an electrolyte and generates electricity by an electrochemical reaction between hydrogen and oxygen, and only water is generated during power generation. Thus, unlike the conventional internal combustion engine, it is expected to spread as a next-generation clean energy system because it does not generate environmental load gas such as carbon dioxide. In particular, the polymer electrolyte fuel cell has a low operating temperature and low electrolyte resistance. In addition, it uses a highly active catalyst, so it can obtain high output even in a small size. Is expected. As shown in FIG. 9, the current polymer electrolyte fuel cell 210 generally uses an electrolyte membrane 21 having hydrogen ion conductivity as an electrolyte, and a catalyst layer that is smaller or slightly smaller on both sides of the electrolyte membrane 21. A catalyst electrode 23 composed of 231 and an electrode base material 232 is formed, and this is further sandwiched by a separator 25 in which a groove 27 is formed via a gasket 217 (for example, Patent Document 1). The pattern of the groove 27 includes various shapes such as a parallel groove type (straight type) and a meandering groove type (serpentine type). An electrochemical reaction occurs by supplying a fuel such as hydrogen or methanol to one groove 27a and an oxidant gas such as oxygen or air to the other groove 27b, and the polymer electrolyte fuel cell generates power.
Japanese Patent Application Laid-Open No. 06-068884

  However, as described above, the catalyst electrode 23 is formed on both surfaces of the electrolyte membrane 21 (FIG. 9B), and if there are many portions Y not facing the groove 27, the fuel gas and The oxidant gas diffuses from the portion X facing the groove 27 of the catalyst electrode 23 to the portion Y not facing the groove 27, and as a result, the amount reaching the three-phase interface where the electrochemical reaction occurs is reduced. There is a problem that the catalyst containing noble metal, which is generally an expensive material, is not effectively used.

  Accordingly, an object of the present invention is to provide a polymer electrolyte fuel cell in which the catalyst can be effectively used and the cost can be reduced.

  As a means for solving the above problems, a first polymer electrolyte fuel cell according to the present invention is a membrane in which a catalyst electrode comprising a catalyst layer and an electrode substrate on the catalyst layer is provided on both surfaces of an electrolyte. A solid polymer fuel cell comprising: an electrode assembly; and a pair of separators sandwiching the membrane / electrode assembly and having a groove for a gas channel formed on a surface facing the membrane / electrode assembly In the present invention, at least one of the catalyst electrodes is provided in a region facing a region in which a groove of the separator disposed on the catalyst electrode is formed.

  It is preferable that a pressing portion for electrically connecting the catalyst electrode and the separator is formed by projecting into the groove of the separator and pressing the catalyst electrode. In addition, this press part can include the step part formed in the side surface of the said groove | channel, or can also contain the protrusion formed in the bottom face of the said groove | channel.

  Further, a current collector in which a filamentary conductor is entangled is accommodated in a space surrounded by the electrode base material and the groove, and the catalyst electrode and the separator are electrically connected by the current collector. It is also possible to provide gas flow paths at body entanglement intervals.

  Alternatively, as a means for solving the above-mentioned problems, the polymer electrolyte fuel cell according to the second invention includes a membrane / catalyst layer assembly in which catalyst layers are provided on both surfaces of the electrolyte membrane, and the membrane / catalyst layer. At least one of the catalyst layers in a polymer electrolyte fuel cell comprising a pair of separators sandwiching a joined body and having a groove for a gas flow path formed on a surface facing the membrane / catalyst layer joined body Is provided in a region facing the region where the groove of the separator is formed, and a current collector in which a thread-shaped conductor is entangled is accommodated in a space surrounded by the catalyst layer and the groove, A catalyst layer and a separator are electrically connected, and the entanglement interval of the filamentous conductor entangled body provides a gas flow path.

  In the polymer electrolyte fuel cells according to the first and second inventions, the catalyst layer can be formed on the electrolyte membrane by transfer.

  Further, as a means for solving the above-mentioned problem, a first polymer electrolyte fuel cell manufacturing method according to the present invention is a polymer electrolyte fuel cell manufacturing method for providing a gas flow path in a separator. A first step of forming a groove, a second step of forming a catalyst layer in a region on the electrolyte membrane opposite to the region where the groove is formed, and the separator into the groove of the separator. And a third step of sandwiching the electrolyte membrane so that the catalyst layer is accommodated.

  In addition, as a means for solving the above-mentioned problem, the second method for producing a polymer electrolyte fuel cell according to the present invention is a catalyst comprising a catalyst layer and an electrode substrate on the catalyst layer on both surfaces of the electrolyte membrane. A membrane / electrode assembly provided with electrodes, and a pair of separators sandwiching the membrane / electrode assembly and having grooves for gas flow passages formed on the surface facing the membrane / electrode assembly A method for producing a polymer electrolyte fuel cell, comprising: a first step of preparing the electrolyte membrane; and a second step of forming a transfer sheet by coating and forming the catalyst layer on a transfer substrate. A third step of transferring the catalyst layer of the transfer sheet onto at least one surface of the electrolyte membrane by hot pressing, and peeling off the transfer substrate; and a step of laminating the electrode substrate on the catalyst layer. Step 4 and sandwiching the membrane-electrode assembly by the separator The catalyst layer is placed on the transfer substrate so that the catalyst layer is provided in a region facing the region where the groove of the separator is formed in the second step. It is characterized by forming a coating. In the fifth step, a current collector in which a filamentary conductor is entangled may be accommodated in a space surrounded by the electrode material and the groove.

  Further, as a means for solving the above-mentioned problem, a third polymer electrolyte fuel cell production method according to the present invention comprises a membrane / catalyst layer assembly in which a catalyst layer is provided on both surfaces of an electrolyte membrane, A method for producing a polymer electrolyte fuel cell comprising a pair of separators sandwiching a membrane / catalyst layer assembly and having a groove for a gas flow path formed on a surface facing the membrane / catalyst layer assembly A first step of preparing the electrolyte membrane; a second step of forming a transfer sheet by coating and forming the catalyst layer on a transfer substrate; and a catalyst layer of the transfer sheet as the electrolyte. A third step of transferring to at least one surface of the film by hot pressing and peeling off the transfer substrate; and a fourth step of laminating a current collector in which a filamentary conductor is entangled on the catalyst layer; The separator allows the current collector to be accommodated in a groove of the separator. A fifth step of sandwiching the catalyst layer assembly, and the catalyst layer is provided in a region facing the region in which the groove of the separator is formed in the second step. The layer is formed by coating on the transfer substrate.

  According to the present invention, since the catalyst electrode is not formed except for the portion facing the separator groove disposed on the catalyst electrode, the catalyst is effectively used, and the amount of the expensive catalyst is reduced. It is possible to reduce the cost.

  Moreover, the press part which protruded in the groove | channel of the separator is formed, and the electrical connection of a separator and a catalyst electrode can be made more reliable by pressing a catalyst electrode with this press part.

  In addition, by accommodating a current collector in which a filamentous conductor is entangled in a space surrounded by the electrode base material and the groove, an electrical connection between the separator and the catalyst electrode can be achieved while ensuring a gas flow path. Can be sure.

  Furthermore, even if the current collector is accommodated in a space surrounded by the catalyst layer and the groove, the electrical connection between the catalyst electrode and the separator can be ensured while ensuring the gas flow path. .

  Further, by forming the catalyst layer by transfer, the catalyst layer can be more easily formed on the electrolyte membrane in the region facing the separator groove.

  Hereinafter, embodiments of a polymer electrolyte fuel cell according to the present invention will be described with reference to the drawings.

  First, a first embodiment of a polymer electrolyte fuel cell according to the present invention will be described. FIG. 1 is a front sectional view (a) and a partially exploded perspective view (b) of a polymer electrolyte fuel cell according to the present embodiment.

  As shown in FIG. 1, this fuel cell 10 includes a membrane / electrode assembly 11 including an electrolyte membrane 1 and a catalyst electrode 3 and a separator 5 and is configured as follows. First, the catalyst electrode 3 having a meandering shape similar to a groove 7 formed in the separator 5 described later is formed on both surfaces of the electrolyte membrane 1, so that the catalyst electrode 3 is disposed on the catalyst electrode 3. The separator 5 is provided on the electrolyte membrane 1 in a region facing the region where the groove 7 is formed. (FIG. 1 (b)). The catalyst electrode 3 includes a catalyst layer 31 and an electrode substrate 32 on the catalyst layer 31. Moreover, in FIG.1 (b), the code | symbol 5a, 5b has shown the gas port.

The membrane / electrode assembly 11 is sandwiched between separators 5, and grooves 7 serving as fuel gas or oxidant gas flow paths are formed in each separator 5 in a meandering shape (FIG. 1 (b). )reference). The groove 7 has a narrow portion 7 a and a wide portion 7 b by forming the pressing portion 51 on the side surface of the groove 7. Here, the width of the catalyst electrode 3 is wider than the width w ₁ of the narrow portion 7a of the grooves 7 has become equal to or narrower as the width w ₂ of the wide portion 7b, also, the height of the catalyst electrode 3 is wide portion It is slightly larger than 7b depth d _2. With such a structure, when the membrane / electrode assembly 11 is sandwiched between the separators 5, the pressing portion 51 of the groove 7 presses the catalyst electrode 3, and the catalyst electrode 3 and the separator 5 are surely connected. The electrons generated by the electrochemical reaction can be stably taken out from the catalyst electrode 3 by being in contact with and electrically connected to each other. At this time, the catalyst electrode 3 pressed by the pressing portion 51 bites into the electrolyte membrane 1. Moreover, in order to press the catalyst electrode 3 with the press part 51 as mentioned above, the narrow part 7a can be ensured reliably as a gas flow path.

For example, the width w ₁ of the narrow portion 7a of the groove 7 is preferably 100 to 2000 μm, more preferably 500 to 1500 μm, and the width w ₂ of the wide portion 7b is preferably 120 to 2500 μm. More preferably, the thickness is 500 to 2000 μm. The width of the catalyst electrode 3 is preferably about 0 to 500 μm, more preferably about 0 to 200 μm, narrower than the width w ₂ of the wide portion 7 b. The depth _{d 1} of the narrow portion 7a is preferably set to 50 to 2000 m, it is more preferred to 100 to 1000 [mu] m. Furthermore, the depth _{d 2} of the wide portion 7b is preferably to 10 to 300 [mu] m, more preferably, to 20 to 200 [mu] m, the height of the catalyst electrode 3 than the depth _{d 2} of the wide portion 7b 0～300Myuemu It is preferably large and more preferably 0 to 100 μm.

  Next, the material of the fuel cell 10 configured as described above will be described. The electrolyte membrane 1 in the present invention is formed, for example, by applying a solution containing a hydrogen ion conductive polymer electrolyte on a substrate and drying it. Examples of the hydrogen ion conductive polymer electrolyte include a perfluorosulfonic acid-based fluorine ion exchange resin, more specifically, a perfluorocarbonsulfonic acid-based resin in which the C—H bond of a hydrocarbon ion-exchange membrane is substituted with fluorine. Examples include polymers (PFS polymers). By introducing a fluorine atom having high electronegativity, it is chemically very stable, the dissociation degree of the sulfonic acid group is high, and high ion conductivity can be realized. Specific examples of such a hydrogen ion conductive polymer electrolyte include “Nafion” (registered trademark) manufactured by DuPont, “Flemion” (registered trademark) manufactured by Asahi Glass Co., Ltd., and “Aciplex” manufactured by Asahi Kasei Corporation. ”(Registered trademark),“ Gore Select ”(registered trademark) manufactured by Gore, and the like. The concentration of the hydrogen ion conductive polymer electrolyte contained in the hydrogen ion conductive polymer electrolyte-containing solution is usually about 5 to 60% by weight, preferably about 20 to 40% by weight. In addition, the film thickness of the electrolyte membrane 1 is about 20-250 micrometers normally, Preferably it is about 20-80 micrometers.

  Moreover, the catalyst electrode 3 is comprised from the catalyst layer 31 and the electrode base material 32, and the catalyst layer 31 is a well-known platinum containing catalyst layer (a cathode catalyst and an anode catalyst). Specifically, the catalyst layer 31 contains carbon particles carrying catalyst particles and a hydrogen ion conductive polymer electrolyte. Examples of the catalyst particles include platinum and platinum compounds. Examples of the platinum compound include an alloy of platinum and at least one metal selected from the group consisting of ruthenium, palladium, nickel, molybdenum, iridium, iron and the like. In general, the catalyst particles contained in the cathode catalyst layer are platinum, and the catalyst particles contained in the anode catalyst layer are an alloy of the metal and platinum. Moreover, as a hydrogen ion conductive polymer electrolyte, the same material as what is used for the electrolyte membrane 1 mentioned above can be used.

  As the electrode base material 32, various electrode base materials constituting a fuel electrode and an air electrode can be used, and in order to efficiently supply fuel gas and oxidant gas as fuel to the catalyst layer 31, the electrode base material 32 is porous. It is made of a conductive substrate. Examples of the porous conductive substrate include carbon paper and carbon cloth.

  The separator 5 may be any known conductive plate that is known and stable even in the environment inside the fuel cell. In general, a carbon plate in which the groove 7 is formed is used. In addition, the separator 5 is made of a metal such as stainless steel, and the surface of the metal is formed with a coating made of a conductive material such as chromium, a platinum group metal or oxide thereof, or a conductive polymer. It is also possible to use a metal having a metal surface plated with a material such as silver, a platinum group composite oxide, or chromium nitride.

  Next, an example of a method for manufacturing the fuel cell 10 described above will be described with reference to FIG.

  First, a method for producing the transfer sheet 13 will be described. A catalyst paste is prepared by mixing and dispersing the carbon particles supporting the catalyst particles and the hydrogen ion conductive polymer electrolyte in an appropriate solvent, so that the formed catalyst layer has a desired thickness. According to a known method, it may be coated on the transfer substrate 9 through a release layer as necessary. At this time, the catalyst paste is applied to the transfer substrate 9 so that the catalyst layer 31 has a meandering shape similar to the groove 7 of the separator 5. The method for applying the catalyst paste is not particularly limited, and a printing method that can be generally patterned, such as screen printing or gravure printing, may be applied. Examples of the solvent include various alcohols, various ethers, various dialkyl sulfoxides, water, or a mixture thereof. Of these, alcohols are preferable. Examples of alcohols include monohydric alcohols having 1 to 4 carbon atoms such as methanol, ethanol, n-propanol, isopropanol, n-butanol, tert-butanol, and various polyhydric alcohols.

  Examples of the transfer substrate 9 include polyimide, polyethylene terephthalate, polyparvanic acid aramid, polyamide (nylon), polysulfone, polyethersulfone, polyphenylene sulfide, polyether ether ketone, polyetherimide, polyarylate, and polyethylene. Examples thereof include polymer films such as naphthalate.

  Further, heat resistance of ethylene tetrafluoroethylene copolymer (ETFE), tetrafluoroethylene-hexafluoropropylene copolymer (FEP), tetrafluoroperfluoroalkyl vinyl ether copolymer (PFA), polytetrafluoroethylene (PTFE), etc. Fluorine resin can also be used.

  In addition to the polymer film, the transfer substrate 9 may be coated paper such as art paper, coated paper, and lightweight coated paper, or non-coated paper such as notebook paper and copy paper.

  The thickness of the transfer substrate 9 is usually about 6 to 100 μm, preferably about 10 to 30 μm, from the viewpoints of handleability and economy.

  Accordingly, the transfer substrate 9 is preferably an inexpensive and easily available polymer film, more preferably polyethylene terephthalate.

  Then, after applying the catalyst paste, the catalyst layer is formed on the transfer substrate 9 by drying at a predetermined temperature and time. A drying temperature is about 40-100 degreeC normally, Preferably it is about 60-80 degreeC. Although depending on the drying temperature, the drying time is usually about 5 minutes to 2 hours, preferably about 10 minutes to 1 hour.

  The transfer sheet 13 produced in this way is arranged so that the catalyst layer 31 faces the electrolyte membrane 1 (FIG. 2A), and a heat press is applied from the back side of the transfer sheet 13 to remove the catalyst layer 31 from the electrolyte membrane. 1 is transferred (FIG. 2B), and the transfer substrate 9 of the transfer sheet 13 is peeled off (FIG. 2C). This operation is performed on both surfaces of the electrolyte membrane 1 (FIG. 2D). In consideration of workability, it is preferable to simultaneously laminate the catalyst layers on both surfaces of the electrolyte membrane 1. Thus, since the catalyst paste is applied to the transfer substrate 9 so that the catalyst layer 31 has a meandering shape similar to that of the groove 7 of the separator 5, the electrolyte membrane 1 in the region facing the groove 7 of the separator 5. A catalyst layer 31 is formed thereon.

  The pressure level of the heating press is usually about 0.5 to 20 MPa, preferably about 1 to 10 MPa in order to avoid transfer failure. Further, it is preferable to heat the pressing surface during this pressing operation in order to avoid transfer failure. The heating temperature is usually 200 ° C. or lower, preferably 150 ° C. or lower in order to avoid breakage, deformation, etc. of the electrolyte membrane 1.

  Then, the electrode base material 32 is laminated on the catalyst layer 31 by thermocompression bonding to complete the membrane / electrode assembly 11 (FIG. 2E).

  Then, the separator 5 sandwiches the membrane-electrode assembly 11 so that the catalyst electrode 3 is pressed by the pressing portion 51 of the groove 7 and is electrically connected to the separator 5, and the fuel cell 10 is completed (FIG. 2). (F)).

  As described above, in the fuel cell according to the present invention, the catalyst electrode 3 having the same shape as that of the groove 7 is formed, so that the catalyst utilization rate can be improved. Moreover, since the catalyst layer 31 etc. with expensive raw material cost can be reduced in connection with this, cost reduction can also be achieved.

  Moreover, in this embodiment, although the press part 51 is formed in the side surface of the groove | channel 7, the press part 51 can also be formed in the bottom face of the groove | channel 7, as shown in FIG. At this time, it is preferable that the pressing portion 51 has a height sufficient to press the catalyst electrode 3.

  Next, a second embodiment of the present invention will be described with reference to FIG. FIG. 4 is a front sectional view of the polymer electrolyte fuel cell according to the present embodiment.

  As shown in FIG. 4, the fuel cell 10 includes a membrane / catalyst layer assembly 12 and a separator 5, and a catalyst layer 31 is disposed on the catalyst layer 31 in a groove of a separator 5 described later. 7 is provided on the electrolyte membrane 1 in a region facing the region where 7 is formed. The groove 7 of the separator 5 is formed in a meandering shape and does not have a pressing portion unlike the first embodiment. Here, the width of the groove 7 is the same as or slightly larger than the width of the catalyst electrode 3.

  On the catalyst layer 31, a current collector 33 entangled with a filamentous conductor is laminated, and when the membrane / electrode assembly 11 is sandwiched between the separators 5, the current collector 33 becomes a groove of the separator 5. 7 is compressed and accommodated. Thus, in order to press the current collector 33 with the groove 7 of the separator 5, the catalyst electrode 3 composed of the catalyst layer 31 and the current collector 33 and the groove 7 of the separator 5 are reliably in contact and electrically connected. Electrons generated by the electrochemical reaction can be stably taken out from the catalyst electrode 3. Furthermore, since the current collector 33 can have a sufficient entanglement interval, the entanglement interval can be provided as a gas flow path.

  The material of the current collector 33 can be, for example, conductive carbon fiber. Other materials for the electrolyte membrane 1, the catalyst layer 31, and the separator 5 can be the same as those in the first embodiment.

  Further, in the present embodiment, the current collector 33 in which the filamentous conductor is entangled is accommodated in the space surrounded by the catalyst layer 31 and the groove 7, but as shown in FIG. The separator 5 and the catalyst electrode 3 are electrically connected by stacking and forming the electrode substrate 32 and housing the current collector 33 entangled with the filamentous conductor in the space surrounded by the electrode substrate 32 and the groove 7. May be connected. Further, the current collector 33 entangled with the filamentous conductor has a sufficient entanglement interval for allowing the gas to flow.

  The first and second embodiments of the present invention have been described above. However, the present invention is not limited to this, and various modifications can be made without departing from the spirit of the present invention. For example, in the above embodiment, the catalyst electrode 3 is formed on the entire electrolyte membrane 1 in a region facing the region where the groove 7 is formed, but not in the entire region, as shown in FIG. Alternatively, it may be formed only on a part of the electrolyte membrane 1 in a region facing the region where the groove 7 is formed.

  Further, as shown in FIG. 7, the cathode-side catalyst electrode 3 b can be formed on the entire surface of the electrolyte membrane 1. In the case of supplying hydrogen as fuel to the anode side catalyst electrode 3a, the oxygen reduction reaction on the cathode side is rate-determining, so that a high output can be obtained by increasing the reaction field relating to the oxygen reduction reaction.

  On the contrary, as shown in FIG. 8, the anode-side catalyst electrode 3 a can be formed on the entire surface of the electrolyte membrane 1. In the case where methanol is supplied as fuel to the anode side catalyst electrode 3a, the methanol oxidation reaction on the anode side is rate limiting, so that a high output can be obtained by increasing the reaction field relating to the methanol oxidation reaction.

  In the present embodiment, the groove 7 and the catalyst electrode 3 have a meandering shape, but can be applied to various other shapes such as a parallel linear shape.

  The present invention will be described more specifically with reference to the following examples and comparative examples. The present invention is not limited to the following embodiment. The above-described embodiment is an exemplification, and the present invention has any configuration that has substantially the same configuration as the technical idea described in the claims of the present invention and that exhibits the same effects. It is contained in the technical range.

  As an example, a polymer electrolyte fuel cell shown in FIG. 1 is produced. First, an electrolyte membrane 1 made of Nafion (registered trademark) was prepared. The electrolyte 1 has a size of 70 mm × 70 mm and a thickness of 50 μm.

Next, a catalyst layer paste made of platinum-supported carbon catalyst and Nafion (registered trademark) is applied onto a transfer substrate 9 made of polyethylene terephthalate with a thickness of 25 μm by a die coater, and the temperature is 100 ° C. for 15 minutes. A transfer sheet 13 was prepared by drying. This transfer sheet 13 is arranged on both surfaces of the electrolyte membrane 1 so that the catalyst layer 31 faces the electrolyte membrane 1, and is heated and pressed at 130 ° C. and 2 MPa to peel off the transfer substrate. And the electrode base material 32 was formed on the catalyst layer 31, and the membrane electrode assembly 11 was produced. The separator 5 was joined so as to sandwich the membrane / electrode assembly 11 thus produced, and thus the polymer electrolyte fuel cell 10 according to this example was produced. The width w ₁ of the narrow portion 7a of the groove 7 formed in the separator 5 is 700 μm, the width w ₂ of the wide portion 7b is 800 μm, the width of the catalyst electrode 3 is 750 μm, and the interval s between the catalyst electrodes 3 is 500 μm, narrow portion 7a 500 [mu] m depth _{d 1} of the wide portion 7b of the depth _{d 2} was 200 [mu] m.

  As a comparative example, the same polymer electrolyte fuel cell as in the above example was prepared except that there was no pressing portion in the shape of the catalyst electrode and the groove of the separator. As shown in FIG. 9, the catalyst electrode 3 was formed on the electrolyte membrane 1 by using a transfer sheet that was slightly smaller in a rectangular shape. That is, the polymer electrolyte fuel cell 210 having the catalyst electrode 3 formed on almost the entire surface of the separator 25 irrespective of the shape of the groove 27 of the separator 25 was formed.

  As described above, Example 1 and Comparative Example 1 were prepared by supplying hydrogen gas as a fuel gas and air as an oxidant gas at about 80 ° C. to the prepared polymer electrolyte fuel cells of Examples and Comparative Examples. Example 2 and Comparative Example 2 were prepared by supplying an aqueous methanol solution and supplying air as an oxidant gas at about 50 ° C. Table 1 shows the results of the experiment performed by the above method.

表１の通り、実施例１は比較例１よりも出力密度が大きく、実施例２も同様に比較例２より最大出力密度が大きくなっており、溝７に沿って触媒電極３が形成されることにより最大出力密度が増加するということがいえる。

As shown in Table 1, Example 1 has a higher output density than Comparative Example 1, and Example 2 similarly has a maximum output density higher than that of Comparative Example 2, and the catalyst electrode 3 is formed along the groove 7. It can be said that this increases the maximum power density.

FIG. 1 is a front sectional view (a) and a partially exploded perspective view (b) showing a first embodiment of a polymer electrolyte fuel cell according to the present invention. It is front sectional drawing which shows the manufacturing method of the polymer electrolyte fuel cell which concerns on this invention. It is front sectional drawing which shows another example of 1st Embodiment. It is front sectional drawing which shows 2nd Embodiment of the polymer electrolyte fuel cell which concerns on this invention. It is front sectional drawing which shows another example of 2nd Embodiment. FIG. 4 is a partially exploded perspective view showing another embodiment of the polymer electrolyte fuel cell according to the present invention. FIG. 4 is a partially exploded perspective view showing another embodiment of the polymer electrolyte fuel cell according to the present invention. FIG. 4 is a partially exploded perspective view showing another embodiment of the polymer electrolyte fuel cell according to the present invention. It is front sectional drawing (a) and an exploded perspective view (b) which show the polymer electrolyte fuel cell of a prior art example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Electrolyte membrane 3 Catalyst electrode 31 Catalyst layer 32 Electrode base material 33 Current collector 5 Separator 51 Press part 7 Groove 9 Transfer base material 10 Polymer electrolyte fuel cell 11 Membrane / electrode assembly 13 Transfer sheet

Claims (11)

A membrane / electrode assembly in which a catalyst electrode comprising a catalyst layer and an electrode substrate on the catalyst layer is provided on both surfaces of the electrolyte membrane;
In a polymer electrolyte fuel cell comprising a pair of separators sandwiching the membrane-electrode assembly and having a groove for a gas flow path formed on a surface facing the membrane-electrode assembly,
At least one of the catalyst electrodes is provided in a region facing a region where the groove of the separator is formed.   2. The solid polymer according to claim 1, wherein a pressing portion that electrically connects the catalyst electrode and the separator is formed by projecting into the groove of the separator and pressing the catalyst electrode. Fuel cell.   3. The polymer electrolyte fuel cell according to claim 2, wherein the pressing portion includes a step portion formed on a side surface of the groove.   3. The polymer electrolyte fuel cell according to claim 2, wherein the pressing portion is formed on a bottom surface of the groove and includes a protrusion. In a space surrounded by the electrode base material and the groove, a current collector entangled with a filamentous conductor is accommodated, and the catalyst electrode and the separator are electrically connected by the current collector,
2. The polymer electrolyte fuel cell according to claim 1, wherein the entangling interval of the current collector provides a gas flow path. A membrane / catalyst layer assembly comprising a catalyst layer on both surfaces of the electrolyte membrane;
In the polymer electrolyte fuel cell comprising a pair of separators sandwiching the membrane-catalyst layer assembly and having a groove for a gas flow path formed on a surface facing the membrane-catalyst layer assembly,
At least one of the catalyst layers is provided in a region facing a region where the groove of the separator is formed,
In a space surrounded by the catalyst layer and the groove, a current collector in which a filamentary conductor is entangled is accommodated, and the catalyst layer and the separator are electrically connected by the current collector,
The polymer electrolyte fuel cell according to claim 1, wherein the entangling interval of the current collector provides a gas flow path.   The solid polymer fuel cell according to claim 1, wherein the catalyst layer is formed on the electrolyte membrane by transfer. A method for producing a polymer electrolyte fuel cell, comprising:
A first step of forming a groove for a gas flow path in the separator;
A second step of forming a catalyst layer in a region on the electrolyte membrane facing the region where the groove is formed;
And a third step of sandwiching the electrolyte membrane by the separator so that the catalyst layer is accommodated in the groove of the separator. A membrane / electrode assembly in which a catalyst electrode comprising a catalyst layer and an electrode substrate on the catalyst layer is provided on both surfaces of the electrolyte membrane;
A method for producing a polymer electrolyte fuel cell comprising a pair of separators sandwiching the membrane-electrode assembly and having a groove for a gas flow path formed on a surface facing the membrane-electrode assembly. And
A first step of preparing the electrolyte membrane;
A second step of producing a transfer sheet by coating the catalyst layer on a transfer substrate;
A third step of transferring the catalyst layer of the transfer sheet to at least one surface of the electrolyte membrane by hot pressing and peeling off the transfer substrate;
A fourth step of laminating the electrode base material on the catalyst layer;
A fifth step of sandwiching the membrane-electrode assembly by the separator,
The catalyst layer is coated on the transfer substrate so that the catalyst layer is provided in a region facing the region where the separator groove is formed in the second step. A method for producing a polymer electrolyte fuel cell.   10. The solid polymer fuel according to claim 9, wherein in the fifth step, a current collector in which a filamentary conductor is entangled is accommodated in a space surrounded by the electrode base material and the groove. Battery manufacturing method. A membrane / catalyst layer assembly comprising a catalyst layer on both surfaces of the electrolyte membrane;
A method for producing a polymer electrolyte fuel cell comprising a pair of separators sandwiching the membrane / catalyst layer assembly and having a groove for a gas flow path formed on a surface facing the membrane / catalyst layer assembly Because
A first step of preparing the electrolyte membrane;
A second step of producing a transfer sheet by coating the catalyst layer on a transfer substrate;
A third step of transferring the catalyst layer of the transfer sheet to at least one surface of the electrolyte membrane by hot pressing and peeling off the transfer substrate;
A fourth step of laminating a current collector entangled with a filamentary conductor on the catalyst layer;
A fifth step of sandwiching the membrane / catalyst layer assembly by the separator so that the current collector is accommodated in a groove of the separator;
The catalyst layer is coated on the transfer substrate so that the catalyst layer is provided in a region facing the region where the separator groove is formed in the second step. A method for producing a polymer electrolyte fuel cell.

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