JP4253491B2 - Method and apparatus for manufacturing fuel cell electrode - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
TECHNICAL FIELD The present invention relates to an electrode manufacturing method and a manufacturing apparatus used for a fuel cell, particularly a solid polymer electrolyte fuel cell.
[0002]
[Prior art]
A solid polymer electrolyte fuel cell includes a membrane-electrode assembly (MEA) comprising an electrolyte membrane made of an ion exchange membrane, an anode placed on one surface of the electrolyte membrane, and a cathode placed on the other surface of the electrolyte membrane. The cell stack includes a plurality of electrode assemblies and separators that form a fluid flow path for supplying fuel gas (hydrogen) and oxidizing gas (oxygen, usually air) to the anode and cathode. The anode and cathode have a catalyst layer facing the electrolyte membrane, and a diffusion layer is provided between the catalyst layer and the separator. In the solid polymer electrolyte fuel cell, the reaction to convert hydrogen into hydrogen ions and electrons is performed on the anode side, and the hydrogen ions move through the electrolyte membrane to the cathode side, and on the cathode side, oxygen, hydrogen ions, and electrons A reaction to produce water is performed.
[0003]
As the electrolyte membrane, an ion exchange membrane having a thickness of about 10 μm to 100 μm is usually used. The catalyst layer has a thickness of about 1 μm to 10 μm, and is formed on one side or both sides of the electrolyte membrane, and in some cases, on one side of a diffusion layer made of carbon paper or carbon cloth.
[0004]
As a method of applying an electrode material to an electrolyte membrane (or diffusion layer) to form a fuel cell electrode, conventionally, a wet coating method in which an electrode material is directly applied by printing, roller coating, spraying or the like (see, for example, Patent Document 1) Alternatively, a transfer method in which a sheet is removed after a catalyst layer formed by previously applying an electrode material to a polytetrafluoroethylene sheet or the like is attached to an electrolyte membrane by thermal transfer is performed (for example, Patent Document 2). Etc.) In the case of the direct coating method, the solvent easily alters the electrolyte membrane or swells / shrinks, so that cracks are easily generated in the coated catalyst layer. In addition, the method of applying it to another sheet in advance and transferring it to the electrolyte membrane increases the number of steps and becomes complicated, resulting in an increase in cost.
[0005]
In recent years, a so-called dry method in which an electrode material is attached to an electrolyte membrane using electrostatic force and / or a gas (carrier gas) flow has been proposed as a coating method that solves the above-described disadvantages. For example, Patent Document 3 discloses a method of attaching an electrode material to an electrolyte membrane by static electricity in a chamber. Patent Document 4 discloses a method of applying catalyst powder to an electrolyte membrane using both electrostatic force and gas (carrier gas) flow in a chamber. In Patent Document 5, finely divided electrode material is supplied into a gas flow, and powder particles accelerated by the gas flow are sent opposite to the outlet (jet port) of the electrode material using its mass inertia. And a powder layer deposited on a supporting surface such as an electrolyte membrane.
[0006]
[Patent Document 1]
JP-A-9-180728
[Patent Document 2]
JP 10-507305 gazette
[Patent Document 3]
JP-A-3-295168
[Patent Document 4]
JP-A-11-288728
[Patent Document 5]
European Patent Publication No. 0926653
[0007]
[Problems to be solved by the invention]
The coating method described in Patent Document 3 (Japanese Patent Laid-Open No. 3-295168) and Patent Document 4 (Japanese Patent Laid-Open No. 11-288728) is a dry-type coating, and therefore a solvent electrolyte film in a conventional wet-type coating. Problems such as electrode cracking due to attack and swelling / shrinkage can be eliminated. However, in any case, the electrode material is applied to the electrolyte membrane accommodated in the chamber, and the membrane-catalyst assembly cannot be manufactured continuously. Moreover, since it is simultaneous application | coating of the coating surface whole surface, the film thickness etc. for every site | part cannot be controlled.
[0008]
Patent Document 5 (European Patent Publication No. 09266733) describes an electrode material accelerated by a gas flow with respect to an electrolyte membrane sent in a state facing an outlet (jet port) of the electrode material. The mass inertia is used for spray coating, and a membrane-catalyst assembly can be continuously produced. However, it is difficult to obtain a sufficient adhesion force by a coating method based on mass inertia. Moreover, it is application | coating from a single exit, an application | coating surface becomes uniform and the film thickness etc. for every site | part cannot be controlled.
[0009]
The present invention has been made in view of the circumstances as described above, and its purpose is to make an electrode dry, and Electrolyte membrane or diffusion layer It is an object of the present invention to provide a novel fuel cell electrode manufacturing method and manufacturing apparatus capable of producing a longer-life and high-quality electrode by more reliably and uniformly applying the electrode material to the electrode. Another object of the present invention is a novel method for producing a fuel cell electrode, which is capable of producing an electrode having an arbitrary shape or a concentration of each part in a predetermined shape, while producing an electrode in a dry process. It is to provide a manufacturing apparatus. Still another object is to provide a method and an apparatus for manufacturing a fuel cell electrode capable of producing an electrode having a composition changed also in the electrode thickness direction.
[0010]
[Means for Solving the Problems]
In order to solve the above problems, a method of manufacturing a fuel cell electrode includes applying a charge to a powdered electrode material, and electrostatically attaching the charged electrode material onto a photosensitive drum charged in a predetermined pattern. The electrode material on the attached photosensitive drum is fed continuously. In electrolyte membrane or diffusion layer Transferring to at least one surface, and transferring the transferred electrode material to the Electrolyte membrane or diffusion layer It is characterized by comprising at least each step of fixing to the surface.
[0011]
The method according to the invention is sent continuously Electrolyte membrane or diffusion layer This is a method to transfer (apply) the electrode material with electric charge on the surface of the electrode by electrostatic force. Electrolyte membrane or diffusion layer Adhesion to the substrate is ensured and continuous production is possible. further, Electrolyte membrane or diffusion layer The transfer to the electrode is a transfer of the electrode material electrostatically attached onto the photosensitive drum charged in a predetermined pattern, and by appropriately adjusting the charging pattern (charging area shape) and / or the charging strength on the surface of the photosensitive drum, While changing the concentration of the electrocatalyst layer of any pattern, in some cases, Electrolyte membrane or diffusion layer Can be formed on top. Finally, Electrolyte membrane or diffusion layer The electrode material transferred onto the surface is fixed by a conventionally known fixing method. Electrolyte membrane or diffusion layer It becomes a long-life and high-quality fuel cell electrode. It is recommended to perform these steps in an inert gas atmosphere mainly from the viewpoint of safety.
[0012]
In another embodiment of the method of the present invention, a charged electrode material is once electrostatically attached to a conductive developing roller covered with an insulating coating film, and then electrostatically attached onto a photosensitive drum charged in a predetermined pattern. To be made to. In this aspect, since the electrode material electrostatically attached to the surface of the developing roller with a substantially uniform film thickness becomes electrostatically attached onto the photosensitive drum, the uniformity of the electrode catalyst layer formed on the surface of the photosensitive drum is further increased. It will be certain. At that time, the developing roller is connected with a polarity opposite to that connected to the means for applying a charge to the powdered electrode material of the charge supply power source.
[0013]
A developing roller having a flat surface may be used as the developing roller, but preferably a roller having minute irregularities formed on the surface is used. Thereby, the uniformity of the film thickness of the electrode material adhering to the surface of the developing roller can be further enhanced. As the minute unevenness, since the powdered electrode material usually has a diameter of 0.1 μm to 10 μm, it is desirable to have a dimension capable of holding a sphere having such a size.
[0014]
In the method of the present invention, the charged electrode material Electrolyte membrane or diffusion layer Transfer to the top may be performed only once. Electrolyte membrane or diffusion layer A plurality of images may be juxtaposed in the feeding direction, and the transfer may be executed a plurality of times. In the latter case, the electrode configuration can be changed in the thickness direction. In either case, Electrolyte membrane or diffusion layer The feed direction may be a horizontal direction or a vertical direction.
[0015]
In the method of the present invention, it is a preferred embodiment that the powdered electrode material is placed in a vibrating or fluidized state in a container that houses it. As a result, it is possible to avoid the powdered electrode material from being agglomerated in the container or forming so-called “dama”, and an electrode catalyst layer made of an electrode material having a constant particle size distribution can be formed. Electrolyte membrane or diffusion layer Can be formed on top.
[0016]
In the method of the present invention, there is no limitation on the method for applying a charge to the powdered electrode material, but considering the ease and certainty of the applying operation, electrostatic application connected to one electrode of an appropriate charge supply power source. It is preferable to arrange the electrode for the electrode in the electrode material (in this case, the other electrode of the charge supply power source is connected to the developing roller). As the electrostatic application electrode, a fine wire (conductor) having a diameter of 0.1 mm or less is preferably used. The applied voltage is preferably in the range of 100 V to 20 kV, and more preferably a voltage in which direct current and alternating current are superimposed.
[0017]
The present invention also discloses a fuel cell electrode manufacturing apparatus capable of suitably carrying out the above manufacturing method. A manufacturing apparatus according to the present invention comprises a container for storing a powdered electrode material, a means for applying a charge to the powdered electrode material, a photosensitive drum on which the charged electrode material is electrostatically attached in a predetermined pattern, and a photosensitive drum. A means for charging in a predetermined pattern and a position where the electrode material electrostatically adhered in a predetermined pattern on the photosensitive drum can be transferred. Electrolyte membrane or diffusion layer A feeding means for continuously supplying the transferred electrode material Electrolyte membrane or diffusion layer And a fixing means for fixing the toner image to at least one of the fixing means.
[0018]
In the above apparatus, the electrode material housed in the container is given a charge (for example, plus) by means for imparting a charge to the electrode material, and it is in a predetermined pattern with a polarity opposite to that of the electrode material (for example, minus). It electrostatically adheres to the charged area of the photosensitive drum having the charged area. As a means for forming a charged region of a predetermined pattern on the photosensitive drum, a means known in the field of electrostatic copying machines can be appropriately employed. For example, a charging roller for charging the surface of the photosensitive drum, and a photosensitive drum The light projecting device can project the light and remove the portion other than the predetermined pattern. By appropriately setting the light projection pattern from the light projection device, the electrode material is finally attached to the surface of the photosensitive drum in an arbitrary pattern. Instead of roller charging, a wire charging method may be used.
[0019]
The electrode material electrostatically adhered in a predetermined pattern on the photosensitive drum is continuously fed to a position where the electrode material can be transferred by an appropriate feeding means. Electrolyte membrane or diffusion layer The image is transferred onto the image and then fixed by fixing means. There are no particular restrictions on the fixing means, but between the two heated and pressurized rollers facing each other. Electrolyte membrane or diffusion layer With a means for heating and pressurizing and pressing the electrode material, or with two opposing heated plates Electrolyte membrane or diffusion layer Or a means for heating and pressurizing the electrode material for pressure bonding. The applied pressure at that time is 20 kg / cm ² ~ 200kg / cm ² The heating temperature is about 80 ° C to 200 ° C.
[0020]
In another aspect of the apparatus according to the present invention, a conductive developing roller covered with an insulating coating film is provided as means for transferring the charged electrode material to the photosensitive drum. The developing roller is connected to a pole opposite to a pole connected to a means for applying a charge to the electrode material of the charge supply power source, and the charged electrode material once electrostatically adheres to the developing roller as described above. It is electrostatically attached again on the photosensitive drum charged in a predetermined pattern. In this embodiment, the uniformity of the electrode catalyst layer formed on the surface of the photosensitive drum can be further enhanced.
[0021]
The developing roller desirably has minute irregularities on the surface. The method of forming minute irregularities on the roller surface is arbitrary, but the method by shot blasting, the method by etching, the method of pasting the cloth of the screen, the method of pressing or adhering particles of minute metal, carbon, resin, etc. A method of adhering the fibrous material in a flocking method and a method of plating with a plating solution in which particles such as silicon carbide are suspended are effective. As described above, it is desirable that the unevenness, particularly the size of the recesses, can hold a sphere (average electrode material size) having a diameter of about 0.1 μm to 10 μm.
[0022]
The developing roller may be disposed in a container for storing the powdered electrode material and embedded in the stored electrode material, outside the container for storing the powdered electrode material, You may arrange | position close to the exit of the electrode material accommodated in the inside. In the latter case, the electrode material is ejected from the outlet of the container by the Coulomb force, and electrostatically adheres to the surface of the developing roller, but the adhesion is mostly attached to the portion closest to the outlet of the developing roller. Since this tends to occur, the supply of charge to the developing roller is intermittently performed so that a uniform layer is formed. The number of interruptions may be appropriately determined with reference to the rotation speed of the developing roller, the diameter of the roller, etc., but is preferably in the range of 10 to 1000 times per rotation in synchronization with the rotation of the developing roller. In any case, when using a developing roller, it is necessary to control the amount of charge of the electrode material so that the electrostatic adhesion force to the photosensitive drum is larger than the electrostatic adhesion force of the developing roller. .
[0023]
In the apparatus according to the present invention, an apparatus composed of a container, a photosensitive drum, etc. Electrolyte membrane or diffusion layer On the other hand, it is possible to install only one, for example, an apparatus provided with different photosensitive drums such as a charging pattern. Electrolyte membrane or diffusion layer A plurality of them may be juxtaposed in the feed direction. In the latter case, the electrode configuration can be changed in the thickness direction. Electrolyte membrane or diffusion layer A plurality of devices are arranged in the horizontal direction or in the vertical direction in accordance with the feeding direction. One piece Electrolyte membrane or diffusion layer The two devices are placed facing each other so that Electrolyte membrane or diffusion layer An electrode catalyst layer may be formed on both surfaces simultaneously. Installation in the casing in an inert gas atmosphere is recommended mainly from the viewpoint of safety.
[0024]
In the apparatus according to the present invention, it is desirable to provide means for imparting vibration or flow to the electrode material in the container from the viewpoint of preventing the electrode material from agglomerating. As means for that purpose, means for shaking the container from the outside, means for directly applying ultrasonic vibration to the electrode material in the container, and the like are effective.
[0025]
In the present invention, the term “electrode material” means, for example, a mixture of a carbon powder carrying a catalyst substance (for example, Pt) and an electrolyte powder (fluorine functional resin, perfluorosulfonic acid amide, etc.), or It is used for the production of a conventional fuel cell electrode of this type mainly composed of a carbon powder carrying a catalyst material coated with the electrolyte. This It is used as a generic term for powdered electrode catalyst materials. Usually, the diameter is about 0.1 μm to 10 μm. Also electrolyte membrane Perfluorosulfonic acid film, hydrocarbon film of Can be mentioned, Diffusion layer Can include things like carbon cloth and carbon paper. Diffusion layer In this case, the electrode catalyst layer is naturally formed only on one surface. Furthermore, although the fuel cell using the electrode according to the present invention is mounted on an electric vehicle and effectively used as a power source, the application is not limited thereto.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, the present invention will be described based on some embodiments with reference to the accompanying drawings. First, referring to FIG. 1, a solid polymer electrolyte fuel cell 10 having a fuel cell electrode according to the present invention will be described. The fuel cell 10 includes a membrane-electrode assembly including an electrolyte membrane 11 made of an ion exchange membrane, an anode (electrode) 14 laminated on one surface, and a cathode (electrode) 17 laminated on the other surface. The membrane-electrode assembly is sandwiched by a separator 18 that forms a fuel gas channel 21 and an oxidant gas channel 22 for supplying fuel gas (hydrogen) and oxidizing gas (oxygen, usually air) to the anode 14 and cathode 17. To cell 19. The separator 18 is also formed with a refrigerant flow path 23 through which a refrigerant (usually cooling water) for cooling the cells flows. A plurality of cells 19 are stacked to form a cell stack, and one solid polymer electrolyte fuel cell 10 is formed. On the anode 14 side, hydrogen is converted into hydrogen ions and electrons. The hydrogen ions move through the electrolyte membrane 11 to the cathode 17 side, and on the cathode 17 side, a reaction for generating water from oxygen, hydrogen ions, and electrons is performed. Is called.
[0027]
The anode 14 and the cathode 17 have electrode catalyst layers 12 and 15, and diffusion layers 13 and 16 are provided between the electrode catalyst layers 12 and 15 and the separator 18. The electrode catalyst layers 12 and 15 are formed on both surfaces of the electrolyte membrane 11 or formed on one surface of the diffusion layers 13 and 16. The electrode catalyst material constituting the electrode catalyst layers 12 and 15 usually includes a material in which a catalyst noble metal (for example, Pt) is supported on carbon powder and an electrolyte, and has conductivity. In the following, the embodiment of the present invention will be described by taking the case where an electrode catalyst layer is laminated on the electrolyte membrane 11 as an example, but the case where an electrode catalyst layer is formed on the diffusion layers 13 and 16 is also within the scope of the present invention. is there.
[0028]
FIG. 2 is a schematic sectional view showing an embodiment of a fuel cell electrode manufacturing apparatus A according to the present invention. In the figure, 11 is an electrolyte membrane such as a perfluorosulfonic acid membrane, and the electrolyte membrane 11 wound in a roll shape is left in the figure by an appropriate feeding means 30 comprising a driving roller 31 and a driven roller 32. Is sent continuously at a constant speed from right to left.
[0029]
The photosensitive drum 41 is arranged so as to be in contact with the upper surface of the electrolyte membrane 11 to be fed and so that the axis is orthogonal to the feeding direction of the electrolyte membrane 11. The photosensitive drum 41 is rotated at a peripheral speed synchronized with the feeding speed of the electrolyte membrane 11 by an appropriate control device. A pressure roller 42 is disposed at a position facing the photosensitive drum 41 so as to sandwich the electrolyte film 11 so as to rotate at a peripheral speed synchronized with the feeding speed of the electrolyte film 11. A required contact pressure is applied to the electrolyte membrane 11 between the contact roller 42 and the pressure contact roller 42. The electrolyte membrane 11 may be fed only by the contact pressure between the photosensitive drum 41 and the pressure roller 42 without positively feeding the electrolyte membrane 11 by the feeding means 30.
[0030]
A conventionally known fixing device 70 is disposed downstream of the photosensitive drum 41 in the feeding direction of the electrolyte membrane 11. In this example, the fixing device 70 includes pressure and heating rollers 71 and 71 arranged so as to sandwich the electrolyte membrane 11.
[0031]
At least the surface layer of the photosensitive drum 41 is covered with a material such as amorphous silicon or amorphous selenium. Further, a charging roller 43 is provided so as to be in contact with or very close to the photosensitive drum 41, and the photosensitive drum 41 is charged by applying a voltage in which alternating current and direct current are preferably applied to the charging roller 43. . Here, it is assumed that the photosensitive drum 41 is negatively charged. A light projecting device 44 that projects light onto the surface of the photosensitive drum 41 is provided at a position downstream of the charging roller 43 in the rotation direction of the photosensitive drum 41. The light projecting device 44 has the same configuration and functions as those of a conventionally known electrostatic copying machine, and the area projected by the light projecting device 44 on the surface of the photosensitive drum 41 is neutralized and projected. The area that did not exist is left as a charged area in a predetermined pattern, forming a so-called electrostatic latent image.
[0032]
A container 50 for storing a powdered electrode material is disposed so as to be in contact with the photosensitive drum 41. The container 50 has an outlet 51 for the electrode material, and the position downstream of the light projecting place of the photosensitive drum 41 by the light projecting device 41 faces the outlet 51.
[0033]
In the vicinity of the outlet 51 in the container 50, a developing roller 52 is disposed so as to be close to the photosensitive drum 41 and the axis is the same as the axial direction of the photosensitive drum 41. The developing roller 52 is conductive, but the surface is covered with an insulating coating film 53 such as polytetrafluoroethylene or silicon. The developing roller 52 is rotated by a control device (not shown) so that it preferably has the same peripheral speed as that of the photosensitive drum 41.
[0034]
Further, an electrostatic application electrode 54 made of a conductive material such as a thin metal wire is disposed in the container 50, and the electrostatic application electrode 54 is one electrode (here, an appropriate charge supply power source 55). Then it is connected to the positive pole). On the other hand, the other electrode (here, a negative electrode) of the charge supply power supply 55 is connected to the developing roller 52.
[0035]
The operation of the device A will be described. First, the above-described powdered electrode material P is put into the container 50. Further, the electrolyte membrane 11 is set so as to pass between the photosensitive drum 41 and the pressure contact roller 42 and between the pressure / heating rollers 71 and 71. In this state, the charge supply power supply 55 is turned on, and the control device for the entire device (not shown) is also operated. When the charge supply power supply 55 is turned on, the electrode material P is positively charged via the electrostatic application electrode 54 and adheres to the surface of the developing roller 52 connected to the negative electrode with a substantially equal thickness.
[0036]
The outlet 51 of the container 50 is located at a position where the developing roller 52 and the photosensitive drum 41 are very close to each other, and a negatively charged electrostatic latent image is formed on the surface of the photosensitive drum 41 as described above. . For this purpose, the positively charged electrode material P on the developing roller 52 flies and adheres to the photosensitive drum 41 (electrostatic latent image thereof) by the Coulomb force, and forms an image (electrode catalyst) of the electrode material. Layer) is formed.
[0037]
The formed electrode catalyst layer comes into contact with the electrolyte membrane 11 that is sent along with the rotation of the photosensitive drum 41, and is transferred onto the electrolyte membrane 11 between the photosensitive drum 41 and the pressure roller 42. The transferred electrode catalyst layer Pa is fixed by being pressurized and heated by rollers 71 and 71 when passing through the fixing device 70 located downstream, and the electrode catalyst layer 12 is fixed to one surface of the electrolyte membrane 11. An electrode 80 is formed. In addition, when fixing an electrode catalyst layer also to the other surface, the same operation is performed similarly to the other surface. The electrode 80 thus manufactured is wound into a roll shape, and is appropriately cut and trimmed when necessary, and used for assembling the fuel cell 10.
[0038]
FIG. 3 shows another embodiment of the manufacturing apparatus according to the present invention. In addition, in apparatus A1 of FIG. 3, the same code | symbol is attached | subjected to the member which show | plays the same function as what was shown in FIG. 2, and the overlapping description is abbreviate | omitted. In this example, the developing roller 52 is disposed outside the container 50 that stores the powdered electrode material P and in the vicinity of the outlet 51 of the electrode material P stored in the container 50, In this respect, it differs from the device A shown in FIG. In operation, charge supply from the charge supply power supply 55 to the developing roller 52 is intermittently performed. As described above, the number of interruptions is appropriately determined with reference to the rotation speed of the developing roller 52 and the diameter of the roller.
[0039]
Thus, by placing the developing roller 52 outside the container 50, a space is secured, and the amount of adhesion and its uniformity are improved by creating a flow floating state by increasing the voltage applied to the electrode material. An effect is obtained. On the other hand, the adhesion of the electrode material P to the developing roller 52 tends to adhere to a portion close to the outlet 51, but by intermittently supplying the charge to the developing roller 52 as described above, The disadvantage is eliminated, and a layer having a uniform thickness can be formed on the developing roller 52. Other operations are substantially the same as those shown in FIG.
[0040]
There are many other variations of the method and apparatus for manufacturing a fuel cell electrode according to the present invention. Some examples are shown in FIGS. 4 to 7 using the apparatus shown in FIG. 2 as an example (the same applies to the apparatus shown in FIG. 3). The example shown in FIG. 4 is an example in which the entire manufacturing apparatus is accommodated in an appropriate casing 100 and the inside thereof is an inert gas atmosphere such as nitrogen gas. This is to avoid, for example, that the electrode material P containing carbon powder is ignited during fixing by the fixing device 70. In this example, a device 110 for applying a liquid binder onto the electrode catalyst layer after exiting the fixing device 70 is further provided, and a binder drying device 120 is further provided downstream thereof. By providing such an apparatus, the electrode catalyst layer 12 after fixing can be further stabilized. As the binder, a solid polymer electrolyte solution (for example, Nafion solution) is effectively used.
[0041]
The example shown in FIG. 5 is different from that shown in FIG. 2 in that two devices A provided with the photosensitive drum 41 are provided side by side in the transfer direction of the electrolyte membrane 11. Of course, not only two but also three or more may be provided. By doing in this way, it becomes possible to form the electrode catalyst layer of a more complicated pattern on the electrolyte membrane 11 while changing the thickness. Even in this case, if necessary, the entire apparatus may be disposed in an inert gas atmosphere as shown in FIG. 4, and the binder apparatus 110 and the drying apparatus 120 may be provided.
[0042]
The example shown in FIG. 6 is different from the other devices described above in that the electrolyte membrane 11 is transferred in the vertical direction. In the example shown in FIG. 7, the electrolyte membrane 11 is also transferred in the vertical direction. However, in order to simultaneously form the electrode catalyst layers 12 and 15 on both surfaces of the electrolyte membrane 11, photosensitive drums 41 are provided on both sides of the electrolyte membrane 11. Further, it is different from that shown in FIG. 6 in that two manufacturing apparatuses A and A are arranged to face each other. In this case, although not shown, a plurality of manufacturing apparatuses A can also be arranged opposite to each other in the vertical direction, and in this case, the same effect can be brought about by the apparatus shown in FIG.
[0043]
In the above-described embodiment, the developing roller 52 is provided for the purpose of uniforming the adhesion of the electrode material to the photosensitive drum 41. However, in the case where the electrode material P to which an electric charge is applied in the container 50 can fly toward the photosensitive drum 41 without using the developing roller 52, the developing roller 52 can be omitted. Further, instead of the developing roller 52, a simple feed roll (not shown) may be arranged.
[0044]
In the case where the developing roller 52 is used, it is desirable that the developing roller 52 has minute irregularities S on the surface as shown in FIG. Thereby, the adhesion and holding of the electrode material P on the surface of the developing roller is further ensured, and the transfer to the photosensitive drum 41 is stabilized. 9A to 9F show some examples of minute irregularities S formed on the surface of the developing roller 52. FIG. In FIG. 9 a, the unevenness S is formed by shot blasting the surface of the developing roller 52. Here, the size of the recess S1 is about 10 μm to 30 μm in diameter and about 5 μm to 20 μm in depth. In FIG. 9b, the unevenness S is formed by etching the surface of the developing roller. The size of the recess S1 may be about the same as that of FIG. 9a.
[0045]
In FIG. 9 c, the unevenness S that can hold the powdered electrode material is provided by attaching a screen cloth 61 to the surface of the developing roller 52. The size of the cavity S1 is desirably a mesh that can hold a sphere (average size of powdered electrode material) having a diameter of about 0.1 μm to 10 μm. In FIG. 9d, the unevenness S (cavity S1) is provided on the surface of the developing roller 52 by pressing or adhering particles 62 such as fine metal having a diameter of about 10 μm to 30 μm.
[0046]
In FIG. 9e, unevenness S that can hold a powdered electrode material by adhering a fibrous material such as carbon or resin having a length of about 10 μm to 100 μm and a diameter of about 10 μm to 30 μm to the surface of the developing roller by a flocking method. (Cavity S1) is formed. In FIG. 9f, the surface of the developing roller is subjected to plating 65 with a plating solution in which particles 64 such as silicon carbide having a diameter of about 10 μm to 30 μm are suspended, so that the irregularities S (cavities) that can hold the powdered electrode material S1) is formed.
[0047]
It will not be necessary to explain that all of these developing rollers 52 can be selectively used as developing rollers in the fuel cell electrode manufacturing apparatus according to the present invention as illustrated in FIGS.
[0048]
FIG. 10 shows an adhesion state of the powder (electrode material) to the developing roller when the voltage applied to the developing roller 52 is changed in the apparatus shown in FIG. Yes. FIG. 10a is an example when the applied voltage is low, and FIG. 10b is an example when a higher voltage is applied. As shown in the figure, it can be seen that the adhesion state of the powder when the applied voltage is high is clearly good, and a good electrode catalyst layer is formed on the electrolyte membrane 11. In addition, when the power is turned off, a sufficient amount of powder cannot be adhered, and it can be sufficiently estimated that the desired electrode catalyst layer is not formed. This demonstrates the effectiveness of the present invention.
[0049]
【The invention's effect】
As described above, according to the present invention, it is possible to produce a fuel cell electrode dry and continuously, and at the same time, Electrolyte membrane or diffusion layer The electrode material can be applied more reliably and homogeneously to produce a long-life and high-quality electrode. In addition, while manufacturing electrodes in a dry manner, it is possible to make an electrode having an arbitrary shape or an electrode having a different concentration or the like at each part in a predetermined shape. It is also possible to make an electrode having a different composition in the electrode thickness direction.
[Brief description of the drawings]
FIG. 1 is a diagram for explaining an example of a solid polymer electrolyte fuel cell provided with a fuel cell electrode in the invention.
FIG. 2 is a diagram for explaining an embodiment of a production apparatus suitable for carrying out the method for producing a fuel cell electrode according to the present invention.
FIG. 3 is a diagram for explaining another embodiment of a production apparatus suitable for carrying out the method for producing a fuel cell electrode according to the present invention.
FIG. 4 is a view for explaining still another embodiment of a fuel cell electrode manufacturing apparatus according to the present invention.
FIG. 5 is a view for explaining still another embodiment of a fuel cell electrode manufacturing apparatus according to the present invention.
FIG. 6 is a view for explaining still another embodiment of a fuel cell electrode manufacturing apparatus according to the present invention.
FIG. 7 is a view for explaining still another embodiment of a fuel cell electrode manufacturing apparatus according to the present invention.
FIG. 8 is a perspective view illustrating an example of a developing roller.
FIG. 9 is an enlarged cross-sectional view showing a main part in another embodiment of the developing roller.
FIG. 10 is a diagram comparing the adhesion state of powdered electrode materials.
[Explanation of symbols]
A, A1 ... Fuel cell electrode manufacturing apparatus, P ... Powdered electrode material, 11 ... Electrolyte membrane, 12, 15 ... Electrode catalyst layer, 13, 16 ... Diffusion layer, 14 ... Anode, 17 ... Cathode, 18 ... Separator , 19 ... cell, 30 ... electrolyte film feeding means, 41 ... photosensitive drum, 42 ... pressure roller, 43 ... charging roller, 44 ... light projector, 50 ... container for powdered electrode material, 51 ... exit , 52 ... developing roller, 53 ... insulating coating film, 54 ... electrostatic application electrode, 55 ... charge supply power source, 70 ... fixing device, 100 ... casing for making the entire manufacturing apparatus an inert gas atmosphere, 110 ... A device for applying a liquid binder, 120 ... a drying device for the binder, S ... irregularities on the surface of the developing roller, S1 ... a recess or a cavity

Claims (10)

A charge is applied to the powdered electrode material, the charged electrode material is electrostatically attached to a conductive developing roller covered with an insulating coating film, and the electrode material on the electrostatically attached developing roller has a predetermined pattern. Electrostatically adheres to a charged photosensitive drum, and transfers the electrode material on the electrostatically adhered photosensitive drum to at least one surface of the electrolyte membrane or diffusion layer that is continuously fed, and transfers the transferred electrode material A method for producing a fuel cell electrode, comprising at least each step of fixing to an electrolyte membrane or a diffusion layer . 2. The method for producing a fuel cell electrode according to claim 1, wherein the electrode material is an electrode material having a diameter of 0.1 [mu] m to 10 [mu] m . Method for manufacturing a fuel cell electrode according to claim 1 or 2, characterized by using a material obtained by forming minute irregularities on the surface as the developing roller. 4. The method of manufacturing a fuel cell electrode according to claim 1, wherein the electrode material is transferred onto the electrolyte membrane or the diffusion layer a plurality of times, and the configuration of the electrode is changed in the thickness direction. .   The method for producing a fuel cell electrode according to any one of claims 1 to 3, wherein the electrode material is placed in a state where it vibrates or flows in a container containing electrode material powder. A container for storing a powdered electrode material; means for applying a charge to the powdered electrode material; a conductive developing roller covered with an insulating coating film to which the charged electrode material is electrostatically attached; The photosensitive drum to which the electrode material on the electro-deposited developing roller electrostatically adheres in a predetermined pattern, means for charging the photosensitive drum in a predetermined pattern, and the electrode material electrostatically attached in a predetermined pattern onto the photosensitive drum can be transferred. production of Do and continuously supplying feed means an electrolyte membrane or a diffusion layer in position, fixing means for fixing the transferred electrode material to the electrolyte membrane or a diffusion layer, a fuel cell electrode, characterized in that it comprises at least a city apparatus. The apparatus for producing a fuel cell electrode according to claim 6, wherein the developing roller has minute irregularities on a surface thereof. 8. The fuel cell electrode according to claim 6, wherein the developing roller is disposed in a container for storing the powdered electrode material and embedded in the stored electrode material. 9. Manufacturing equipment. The developing roller is outside the container for storing the powdered electrode material, and is disposed in the vicinity of the outlet of the electrode material stored in the container, and the supply of electric charge to the developing roller is interrupted. 8. The fuel cell electrode manufacturing apparatus according to claim 6, wherein the fuel cell electrode manufacturing apparatus is performed. The means for charging the photosensitive drum with a predetermined pattern includes a charging roller for charging the surface of the photosensitive drum, and a light projecting device for projecting light on the photosensitive drum and discharging the portion other than the predetermined pattern. We claim 6 manufacturing apparatus for a fuel cell electrode according to 9 or.

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