JP2006164910A - Electrochemical device, its manufacturing method, and cellular phone equipped with it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an electrochemical device which is reduced in fluid resistance without using a liquid diffusion layer and capable of generating electrical energy efficiently. <P>SOLUTION: The electrochemical device of this invention comprises fluid channel members which have fluid channel parts for letting a fluid pass through, catalyst layers each of which has an interface and contains catalyst components, and an ion conductive layer. The respective catalyst layers are layered on main surfaces of the ion conductive layer so that they are in contact with it on the opposite surface of the interface. In the electrochemical device in which each fluid channel member is layered on the ion conductive layer, the catalyst layers are in contact with the fluid channel parts. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to an electrochemical device.

  An electrochemical device is generally composed of a layer capable of generating or accumulating electrons (charges) and a layer propagating ions. Specific examples of the electrochemical device having such a configuration include a primary battery, a secondary battery, a fuel cell, a solar cell, a capacitor, an electrolysis device, and various sensors. These structures have a structure in which an anode layer and a cathode layer capable of conducting electrons are disposed on both sides of an ion conductive layer. The ion conductive layer may be a liquid or a solid. The ion conduction layer is the heart of the electrochemical device because it conducts charges in the ion conduction layer. In contrast to the structure of the heart of such an electrochemical device, there is an electrochemical device that generates a charge by supplying a fluid. By adopting this configuration, basically all the devices described above can be constructed, but representative examples include fuel cells and electrolysis devices.

  FIG. 1 is a diagram showing the structure of a conventional fuel cell, electrolysis device, or the like. FIG. 2 is a plan view of the fluid passage body shown in FIG. 1 and a cross-sectional view taken along line A-A ′ of the plan view. The electrochemical device shown in FIG. 1 has a configuration of fluid passage body / fluid diffusion layer / catalyst layer / ion conduction layer / catalyst layer / fluid diffusion layer / fluid passage body. The fluid used in such an example passes through the fluid passage body and reaches the catalyst layer through the fluid diffusion layer. As the fluid, a compound capable of reacting with the catalyst contained in the catalyst layer is used. Moreover, a porous body is usually used for the fluid diffusion layer. When the fluid reaches the catalyst layer, a chemical reaction occurs. In the case of an electrochemical device such as a fuel cell, ions generated through such a chemical reaction are conducted through an ion conductive layer to generate electrical energy. On the other hand, in the case of an electrolysis device, ions generated through such a chemical reaction are conducted through the ion conductive layer.

  The electrical energy / ion associated with the electrochemical device is derived from a chemical reaction between the fluid and the catalyst contained in the catalyst layer. Since the fluid flows through the fluid passage body and finally reaches the catalyst layer, the physical arrangement / configuration of the fluid passage body and the catalyst layer is determined in the electrochemical device in order to efficiently contact the fluid and the catalyst. It is one of the very important elements.

  As described above, the electrochemical device in the conventional example has a structure in which the fluid passage body and the catalyst layer sandwich the fluid diffusion layer. The fluid passage body has a structure through which fluid passes. The fluid that has passed through the fluid passage body reaches the catalyst layer, and the reached fluid reacts on the catalyst contained in the catalyst layer. If an electrochemical device having no fluid diffusion layer is used, the fluid is supplied only to the portion where the fluid passage body and the catalyst layer are in contact with each other, and the reaction occurs only in this portion. That is, there is a portion in the catalyst layer that cannot react with the fluid. Therefore, when a device having such a configuration is used, relatively little electric energy can be obtained as compared with electric energy obtained by directly reacting such a fluid with such a catalyst.

  Therefore, in the electrochemical device in the conventional example, in order to avoid such a problem, a fluid diffusion layer usually composed of a porous body is disposed between the fluid passage body and the catalyst layer. By adopting such an arrangement, the fluid that has passed through the fluid passage body passes through the porous body in the fluid diffusion layer, so that the fluid does not contact the catalyst layer locally but contacts the entire catalyst layer. Become. As a result, the fluid and the catalyst come into contact efficiently, and electric energy can be obtained efficiently.

  However, the provision of the fluid diffusion layer is disadvantageous in terms of size (volume) and weight (weight), and there is a situation where it is required to be small and light, particularly in the case of an electrochemical device for portable equipment. In addition, the presence of the fluid diffusion layer is a factor that increases the diffusion resistance of the fluid.

  In addition, the manufacturing method of the catalyst layer and the electron conductive layer relating to the above-described conventional general electrochemical devices (particularly, fuel cells and electrolysis devices) includes a paste mainly containing carbon and containing a catalyst metal in the ion conductive layer. It is manufactured by applying, or by applying the paste on carbon paper or carbon cloth, which is a fluid diffusion layer, and then integrating with the ion transmission film. Generally, a blade coating method, a die coating method, a wire bar coating method, a screen printing method, and a flexographic printing method are applied to this coating process. Since the blade coating method, the die coating method, and the wire bar coating method can be applied continuously to a long substrate, a large area can be applied with high productivity. However, it cannot be applied at an arbitrary position in an arbitrary size (for example, a shape such as a square or a rectangle). There is also a problem that the application position accuracy is not high. In the method using a printing plate such as the screen printing method or flexographic printing method, it is possible to apply it to any position and any size, but to change the printing position and printing shape, it is necessary to remake the plate. There is a problem that must not be.

Examples of methods other than the above coating step include methods such as filtration, electrophoresis, and micellar electrolysis. The filtration method is a method applied to the lamination of a solid substance on a porous substrate, and is also applied to the production of an electrode of an electrochemical device (see Non-Patent Document 1). However, since the laminated shape is defined by the shape of the filtration surface, the correspondence to shape change and shape control is poor. In addition, the finer the particles, the longer the time required for lamination (filtration), and the lower the productivity. Electrophoresis is a technique for moving particles in the direction of an electric field having a polarity opposite to that of the charged particles by applying a direct current electric field to the charged particles in a liquid. This technique has also been applied to the production of electrodes for electrochemical devices (see Non-Patent Document 2). This is a technique in which a membrane and particles are combined by disposing a porous membrane or an ion conductive membrane between positive and negative electrodes (between DC electric fields). However, since the laminated shape is determined by the liquid cross-sectional shape formed by the membrane and the liquid, the correspondence to the shape change and shape control is low as in the filtration method. The micelle electrolysis method is disclosed in Patent Document 1, for example. This method oxidizes or reduces micelles produced by a surface active agent (micellet agent) having a site capable of redox, such as ferrocene, on the electrode surface, disintegrates the micelles, and causes the substances inside the micelles to adhere to the electrode surface. It is a method of depositing. Since this method uses an electrochemical reaction on the electrode surface, it has a disadvantage that can be applied only to the electrode surface, that is, a substrate having electronic conductivity.
Japanese Patent Publication No. 3-59998 2003 Electrochemical Spring Conference, 3N08, P313 2003 Electrochemical Spring Conference, 3N09, P314

  The present invention provides an electrochemical device capable of efficiently generating electric energy with reduced diffusion resistance of a fluid without using a fluid diffusion layer that affects the miniaturization of the device. It aims at providing the manufacturing method of the electrochemical device which can respond to a shape change and / or shape control, without using.

As a result of intensive studies to solve the above problems, the present inventors have invented the following (1) to (16).
(1) A fluid passage body having a fluid passage portion through which fluid passes;
A catalyst layer having a boundary surface and containing a catalyst component; and an ion conducting layer;
With
The catalyst layer is laminated on each principal surface of the ion conductive layer so as to be in contact with the surface opposite to the boundary surface, and the fluid passage body is laminated on the ion conductive layer, respectively. In
The electrochemical device, wherein the catalyst layer is in contact with the fluid passage portion. Thereby, it is possible to provide an electrochemical device that is small and light, reduces the amount of catalyst used, and reduces fluid resistance.
(2) The electrochemical device according to claim 1, wherein the fluid passage body has an electron conducting portion in a portion other than the fluid passage portion. Thereby, the electrochemical device which reduced resistance of the device is obtained.
(3) The electrochemical device according to claim 1 or 2, wherein each of the catalyst layers is substantially opposed to the ion conductive layer. Thereby, the electrochemical device which reduced the ionic resistance of the device can be provided.
(4) The electrochemical device according to claim 2 or 3, wherein each of the electron conducting portions is substantially opposed to the ion conducting layer. Thereby, the electrochemical device which reduced resistance and also reduced ionic resistance is obtained.
(5) The electrochemical device according to any one of claims 1 to 4, wherein the fluid passage portion is non-conductive. As a result, an electrochemical device using a fluid passage body that is easy to manufacture and lightweight can be obtained.
(6) The electrochemical device according to any one of claims 1 to 5, wherein the catalyst component contains platinum. Thereby, the electrochemical device which can perform the oxidation reaction of hydrogen and methanol, and the electrolysis reaction of water is obtained.
(7) The electrochemical device according to claim 6, wherein the catalyst component further contains ruthenium or iridium. Thereby, the electrochemical device which can oxidize ethanol is obtained.
(8) The electrochemical device according to claim 7, wherein the catalyst component further contains at least one metal selected from the group consisting of ruthenium, iridium, tungsten, and tin. Thereby, the electrochemical device which can oxidize ethanol is obtained.
(9) The electrochemical device according to claim 8, wherein the catalyst component contains three or more metals. Thereby, the electrochemical device which generate | occur | produces the electrical energy by various catalytic reactions is obtained.
(10) forming an electrostatic latent image on the carrier;
Electrostatically contacting the electrostatic latent image with the catalyst component; and electrostatically transferring the catalyst component to the ion conductive layer;
A method for producing an electrochemical device, comprising: Thereby, an electrochemical device having a catalyst layer of an arbitrary shape can be manufactured easily (any number of times).
(11) forming an electrostatic latent image on the electrostatic carrier;
Electrostatically contacting the electrostatic latent image with a catalyst component containing an electron conducting component; and electrostatically transferring the catalyst component to the ion conducting layer;
A method for producing an electrochemical device, comprising: As a result, an electrochemical device having an arbitrarily-shaped electron conducting portion can be manufactured easily (any number of times).
(12) The method for producing an electrochemical device according to (10) or (11), wherein the step of forming the electrostatic latent image is performed by collective irradiation, drawing irradiation, or linear irradiation. Thereby, the manufacturing method of the electrochemical device with high adaptability to a shape change can be provided.
(13) The formation method according to any one of claims 10 to 12, wherein the catalyst component contains a polymer compound having binding properties. Thereby, while maintaining the binding property of the particles, the interface resistance can be reduced and the dispersion can be simplified.
(14) The formation method according to (13), wherein the polymer compound is an ion conductive polymer or a fluorine-based polymer. Thereby, the electrochemical stability of the polymer compound can be improved while maintaining the binding property.
(15) The forming method according to any one of claims 11 to 14, wherein the electron conducting component is a material mainly composed of carbon. Thereby, reduction of interface resistance and electrical stability can be improved.
(16) An electrochemical device manufactured using the method according to any one of claims 10 to 15. As a result, an electrochemical device having a catalyst layer and an electron conductive layer that are easy to manufacture and can be arbitrarily shaped is obtained.
(17) A fuel cell comprising the electrochemical device according to any one of claims 1 to 7 and 16. As a result, a fuel cell using an electrochemical device having a catalyst layer and an electron conductive layer that are easy to manufacture and can be arbitrarily shaped is obtained.
(18) The fuel cell according to claim 17, which is driven by ethanol. As a result, a fuel cell using a fuel having excellent safety and environment and high energy density can be obtained.
(19) A portable device comprising the fuel cell according to claim 15. As a result, it is possible to obtain a portable device with high convenience / reliability using a fuel cell using an electrochemical device having a catalyst layer and an electron conductive layer that are easy to manufacture and can be arbitrarily shaped.

  An electrochemical device having a reduced size by integrating a fluid diffusion layer and a catalyst layer is provided.

  Provided is a method for manufacturing an electrochemical device that also supports shape control and the like.

  A conceptual diagram of the structure of the electrochemical device according to the present invention is shown in FIG. FIG. 4 is a diagram showing an example of formation of the catalyst layer used in the present invention, and FIG. 5 is a plan view of the fluid passage body used in FIG. 4 and along the line AA ′ of this plan view. It is sectional drawing.

  The electrochemical device according to the present invention has an ion conductive layer in the center, a catalyst layer on both sides, and a fluid passage on the outside. Hereinafter, the structure of the electrochemical device according to the present invention will be described in the order of the fluid passage body, the catalyst layer, and the ion conductive layer.

(Fluid passage body)
The fluid passage body according to the present invention only needs to have a structure suitable for flowing the fluid used in the electrochemical device according to the present invention. As an example, the fluid passage body shown in FIG. However, the number of passages may be two or more, and may be a mixing passage. FIG. 5A shows a fluid passage body provided with a mixing passage.

  The fluid passage used in the present invention only needs to be chemically stable with respect to the fluid, and is preferably stable with respect to an oxidation-reduction atmosphere formed by the generated charge or the given charge. From the viewpoint of weight reduction and moldability, it is preferably formed of a plastic material, and from the viewpoint of reducing resistance, it is preferably formed of an electronic conductor. More preferably, the surface other than the fluid passage portion through which the fluid flows has electron conductivity, the resistance as a device is reduced, and the surfaces other than the fluid passage portion are preferably made of lightweight and workable plastic. . As a method for imparting conductivity to the surface other than the fluid passage, a conventionally known method such as metal vapor deposition, sputtering or plating can be used.

  Further, the electron conductive portion may be a three-dimensional object instead of the above surface.

  Here, the “three-dimensional object” refers to the fluid passage body itself as “electron conducting member (mainly part other than fluid passage; three-dimensional object)” and “plastic member (mainly fluid passage part; three-dimensional object)”. This means that a plurality of members are used in combination. In this case, since the portion having conductivity is not only the surface, it is advantageous in terms of resistance. In addition, by continuously forming a conductive material from “a surface other than the fluid passage of the fluid passage body” to “a back surface of the fluid passage body where the fluid passage is not formed”, a stacked body of the same electrochemical device is formed. It is possible to adopt a configuration advantageous for (connection) and the like.

(Catalyst layer)
The catalyst layer according to the present invention is disposed between the above-described fluid passage body and an ion conductive layer described later. The catalyst layer has a structure laminated on each main surface of the ion conductive layer, and each catalyst layer is substantially at the same position relative to the ion conductive layer, that is, onset relative to the ion conductive layer. It is preferable to be formed as described above. Since the ion conduction resistance is proportional to the distance, when each catalyst layer is offset relative to the ion conduction layer, the ion movement distance becomes long, and the resistance as an electrochemical device increases.

  The catalyst layer according to the present invention preferably faces the fluid passage portion of the fluid passage body described above. With such a configuration, the fluid used in the electrochemical device according to the present invention comes into sufficient contact with the catalyst contained in the catalyst layer, and the fluid and the catalyst are in efficient contact with each other. The reaction will occur efficiently.

  Although there is no restriction | limiting in particular as a catalyst component contained in the catalyst layer by this invention, It is preferable that it is a compound which can raise | generate a catalyst reaction with the above-mentioned fluid. Specifically, a noble metal simple substance such as platinum or an alloy or a composite of a second component element or a third component element containing a noble metal and a noble metal can be used as a catalyst component. Further, the carrier for the catalyst component may be appropriately selected depending on the conditions under which the substance having a catalytic action and the device used function, but an optical semiconductor represented by aluminum oxide, silicon oxide, carbon, silicon carbide or titanium oxide. Etc. can be used.

  As a combination of a fluid and a catalyst, specifically, a catalyst mainly composed of platinum is preferable for oxidation of hydrogen or organic matter or electrolysis of water, and “platinum and ruthenium or iridium” for alcohol oxidation, particularly methanol oxidation. A catalyst component consisting of "Pt and at least one metal selected from the group consisting of ruthenium, iridium, tungsten and tin" is preferable for the oxidation of ethanol. Further, the catalyst component according to the present invention comprises: It is preferable to use three or more compounds.

(Securing ion / electron conductivity in the electrochemical device according to the present invention)
The electrochemical device according to the present invention comprises:
(1) introducing a fluid through a fluid passage body;
(2) The fluid introduced into the fluid passage body chemically reacts with the catalyst contained in the catalyst layer,
(3) This chemical reaction generates ions / charges,
(4) The generated ions are conducted through the ion conductive layer, while the generated charges flow out to the external circuit.
It operates in the process. In order to efficiently perform the steps shown in (1) to (3), the fluid passage body / catalyst layer / ion conduction layer has been described as described above. On the other hand, ions / electrons are generated as shown in step (4). Therefore, the electrochemical device according to the present invention needs to efficiently extract generated ions / charges. FIG. 6 is a diagram showing an example of this, and is a diagram showing an example of formation of a catalyst layer and an electron conductive layer according to the second embodiment of the present invention.

  In the fluid passage body according to the electrochemical device according to the present invention, it is preferable to provide an electron conducting portion in a portion other than the fluid passage portion. With such a configuration, it is possible to handle charges generated in the catalyst layer or charges to be supplied to the catalyst layer with low resistance. For the same reason, the catalyst component contained in the catalyst layer is preferably conductive.

  When the electrochemical device of the present invention having such a configuration is applied to a fuel cell or an electrolysis device, it is necessary to take out or flow an electric current. It is necessary to take out (or give) charge. In the case where the fluid passage body is an electronic conductor, the surface other than the fluid passage comes into contact with the catalyst layer so that charges can be exchanged by expanding the formation width of the catalyst layer to the surface other than the fluid passage of the fluid passage body. It is also possible to exchange charges by forming an electron conducting portion in contact with the catalyst layer separately on the surface of the ion conducting layer. Further, when the fluid passage body is made of an electron conductive substance, the fluid passage body and the electron conductive layer are in direct contact with each other, so there is no need to widen the catalyst layer as described above, and the effective use of the catalyst. It can be said that this is a preferable configuration in terms of both low resistance and low resistance. For the same reason, it is preferable that the catalyst layer and the electron conductive layer formed on the ion conductive layer are formed at substantially the same position on the front and back of the ion conductive layer.

  By forming such a catalyst layer, a fluid diffusion layer is not required, the entire device can be reduced in size and weight, and the amount of catalyst used can be reduced. Also, the absence of the fluid diffusion layer can reduce the diffusion resistance of the fluid.

(Method for Manufacturing Electrochemical Device According to the Present Invention)
Next, the concept of the method for producing the catalyst layer and the electron conductive layer of the present invention will be described. FIG. 7 is a diagram showing a method for producing the catalyst layer and the electron conductive layer of the present invention.

  First, a charged (static) substrate 1 is prepared. Next, the charged substrate is immersed in a dispersion containing particles that are reversely charged with respect to the substrate, and the particles are attached to the substrate. Next, the substrate is taken out and immersed in a liquid not containing particles, and an ion conductive membrane (or a porous membrane) and the substrate 2 are installed as shown in the figure. A DC electric field is applied so that the substrate 2 side has a polarity opposite to that of the particles (minus in the figure), and the particles adhering to the substrate 1 side are electrophoresed and attached on the ion conductive film. By such an operation, a laminate of the ion conductive membrane and the particles can be produced. Further, by bringing the substrate 1, the ion conductive film, and the substrate 2 close to each other, it is possible to directly transfer to the ion conductive film in one step without using a liquid without particles.

  Hereinafter, the method for producing an electrochemical device according to the present invention will be described in the order of a step of forming an electrostatic latent image, a step of contacting the electrostatic latent image with a catalyst component, and a step of transferring the catalyst component to the ion conductive layer. .

(Process of forming electrostatic latent image)
The electrostatic carrier used in the present invention can be basically used as long as it can carry static electricity, specifically, if the surface has an insulating property or a semiconducting property. Charging methods include charging by physically rubbing two or more types of materials (friction charging), charging using charges generated by applying a high electric field to air (corona discharge), electron guns, etc. Any method such as charging (charge injection) can be used.

  The electrostatic carrier used in the method for producing an electrochemical device according to the present invention preferably has an optical semiconductor layer. The optical semiconductor here is a material capable of generating positive / negative charges by light irradiation. When such a material is used for the electrostatic carrier of the present invention, the charge can be eliminated by irradiating the carrier having the entire surface charged by any of the aforementioned methods. That is, it is possible to leave static electricity on the surface in an arbitrary shape (form an electrostatic latent image) by controlling the portion that is irradiated with light.

  FIG. 8 is a diagram showing the concept of forming electrostatic development according to the present invention. After the photo-semiconductor layer is charged (positive charging indicated by “+” in the figure), light is irradiated through a mask or the like, and the charge is lost only in the light irradiation portion. Next, while rotating the negative charging roller, the catalyst component dispersion (in the figure, negatively charged dispersion) is applied onto the semiconductor layer and at the same time a DC electric field (in the figure, negative charging roller) is applied to remove the catalyst component. Electrophoresis is performed on a positively charged portion on the optical semiconductor layer. Next, a laminate of the ionic conductor and the catalyst layer can be produced by transferring the catalyst component to the ionic conductive film via a positively charged roller.

  According to the method shown in FIGS. 7 and 8, an ion conductor having an arbitrary shape holding the catalyst layer can be easily produced, and the electrostatic latent image carrier (photo semiconductor) can be reused. In general, exposure with light has an advantage that a shape with high resolution can be obtained as compared with the above-described normal coating method.

  As a light irradiation method in an arbitrary shape, it is possible to use a method such as batch irradiation with light photomasks such as a halogen lamp, drawing irradiation in which a semiconductor laser beam is scanned with a mirror, or linear irradiation with an LED array. In particular, drawing with laser light and drawing with an LED array are preferable because they have high resolution, can have complex shapes, and do not use a plate (photomax) and are highly adaptable to shape changes.

  Furthermore, as a preferable configuration of the electrostatic carrier, a shape in which at least the optical semiconductor layer is provided on the conductive substrate is preferable. By adopting such a form, it becomes possible to quickly separate charges generated by light irradiation into positive and negative charges, and the resolution is improved. In particular, it is preferable from the viewpoint of charge separation that the conductive substrate has a polarity (or ground) opposite to the surface charging.

(Step of contacting the electrostatic latent image with the catalyst component)
The catalyst component used in the present invention needs to be charged in the dispersion medium. Utilizing this electrification, the catalyst component is adhered to the electrostatic carrier and further transferred to the ion conductive membrane or the porous membrane. The method using charging is basically based on the electrophoresis phenomenon.

  Electrophoresis is a phenomenon in which movement occurs due to electrostatic attraction acting on the electric charge existing on the surface of a particle (in the present invention, a substance containing a catalyst component and an electron conductive component). To the negative electric field, the negatively charged particles migrate to the positive electric field. When the dispersion medium itself is a dissociative liquid (for example, when the dispersion medium is water, hydrogen ions and hydroxide ions), the particles are charged with ions that have high affinity with the particle surface, The electric charges of the particles are charged with the charges of the ions adsorbed on the particles. In addition, ions having a charge opposite to that of the adsorbed ions surround the particles and form counter ions. When the liquid is not a dissociable liquid (usually a large amount of organic solvent), generally, a charge control substance (such as one having an electrolyte structure) is added to generate the above-described adsorption, thereby imparting a charge to the particles. Of course, the charge may be controlled by adding a charge control substance to a dissociative liquid such as water.

  When using a dissociating liquid, the dispersion liquid used in the present invention can be basically composed of only liquid and particles. However, in this case, the charge controlling substance and the charge amount are determined uniquely by the combination of the particle material and the dispersion medium and cannot be controlled. Is preferably added. The charge control substance used here is not particularly limited, such as an inorganic salt, an organic salt, etc., but is preferably selected as appropriate depending on the surface properties of the particles and the desired charge code. Preferred materials are provided. In addition, in a system in which only particles and a dissociative liquid are added or a charge control substance is added, if the particles are not made small, sedimentation and aggregation occur, and the dispersion cannot be stabilized. A surfactant may be added for the purpose. The surfactants used here are nonionic (polyethylene glycol type, polyhydric alcohol type), cationic (amine salt type, ammonium salt type), anionic (carboxylate type, sulfonate type, sulfuric acid type) (Ester salt type, phosphate ester salt type) or amphoteric (amino acid type, betaine type) can be used, but in order to add charge to particles with a small addition amount, ions such as cationic or anionic Use of a surfactant is preferable because it also has a function of giving a charge to particles. When a non-dissociable liquid is used, a charge control substance (including a surfactant) is essential. For the same reason, it is preferable to use a surfactant because the charge control substance having no surface active effect can control the charge, but the stability of the dispersion is poor.

  The dispersion is prepared by adding particles insoluble in the dispersion medium and, if necessary, a binder polymer compound / conductive agent / charge control agent, etc., to a “homogenizer that refines and mixes particles with a rotary blade” “Three roll mill for refining and mixing particles by the gap of three rotating rolls”, “Sand mill for refining and mixing particles by mixing and stirring beads”, “Particles by ultrasonic vibration Can be prepared by a dispersion method such as “ultrasonic dispersion in which the material is refined and mixed.

  The polymer compound having binding properties used in the present invention is a generic term for compounds that are stable in a dispersion medium and have a property of binding substances (films and particles) contained in the dispersion medium. Specifically, polyfluoroethylene, polyethylene, nitrile rubber, polybutadiene, butyl rubber, polystyrene, styrene / butadiene rubber, nitrocellulose, cyanoethyl cellulose, polyacrylonitrile, polyvinyl fluoride, polyvinylidene fluoride, polychloroprene, polyvinyl pyridine These may be used singly or may be used after being chemically stabilized by mixing and / or copolymerization.

  As the binder, an ion conductive polymer is preferably used. This is because it is possible to use a single material to perform the two functions of binding and ionic conductivity. Specifically, a one-dimensional polymer compound having an ion dissociation group in the molecule can be used. An ion dissociation group refers to a group (an alkylene oxide group, an alkylene imine group, or the like) that can dissociate a group (such as a hydroxyl group, a carboxyl group, or a sulfonic acid group) that can ionize itself or a dissociative substance (such as an electrolyte salt). More specifically, polyacrylic acid, polystyrene sulfonic acid, polyethylene oxide, polypropylene oxide, and derivatives thereof can be used. In addition, a polymer compound having a dissociable group represented by these can also function as the charge control substance.

  In addition, from the viewpoint of electrochemical (redox) and chemical (thermal) stability of the material, it is preferable to use a fluorine-based polymer as the binder. Specifically, polyfluoroethylene, polyvinylidene fluoride, etc. Can preferably be used.

  The most preferable form of the polymer material contained in the dispersion used in the present invention is (1) a function as a charge control material in terms of small size, light weight, low cost, and improvement of the electrochemical performance of the laminate. A material having both 2) a function as an ion conductor, (3) a function as a binder, and (4) (electro) chemical stability is preferable. Specifically, a polymer material having a fluorocarbon structure in the main chain or side chain and containing an ion dissociation group in the molecular chain is preferable. More specifically, a structure having a perfluoroethylene structure and containing an ion dissociation group is preferable, and the ion dissociation group is appropriately set depending on the ion species to be conducted. In the case of a sulfonic acid group, a phosphoric acid group, or a lithium ion, it preferably has an ethylene oxide structure or a propylene oxide structure.

  The electron conducting component referred to in the present invention has a function of assisting the propagation of charges generated in the vicinity of the catalyst, which is stable in the dispersant.

  The electron conductive component used in the dispersion according to the present invention may be any electron conductive material that is stable in the dispersion medium and stable in the operating environment of the device. A carbon-based material is preferable to a metal-based material from the viewpoint of good dispersibility in a medium and the ability to adsorb an ion conductive polymer as a charge control material. Natural graphite, artificial graphite, etc. can be used.

  By using a substance having at least a catalytic action as particles insoluble in the dispersion medium used in the device and / or device manufacturing method of the present invention, an electrochemical catalytic reaction can be carried out. . The substance having a catalytic action here is "a substance that promotes a chemical reaction without changing itself". As for the form of the particles, the substance having a catalytic action is on a non-catalytic support (in order to distinguish it from the "support" of the support supporting static electricity according to the present invention, the medium supporting the catalyst is called the support). It is preferable from the viewpoint of catalyst activity, durability, and utilization efficiency that it is in the form of being supported on the catalyst. Further, in the production method of the present invention, the particles need to be charged, but this charging can be adjusted by the charge control material as described above. Coating or adsorbing a charge control substance on a substance having catalytic ability is not preferable because it reduces the catalytic activity. The production method of the present invention can be carried out without degrading the catalytic ability by selectively coating or adsorbing the charge control material on the carrier by selecting the carrier.

  The catalyst component used in the method according to the present invention can be variously used as long as it is a material that generates electrical energy through a catalytic reaction in combination with a fluid. For example, the above-described catalyst component can be used.

(Process of transferring the catalyst component to the ion conductive layer)
The ion conductive layer used in the present invention has a self-holding property capable of holding a certain shape as a film. The material may be an organic material, an inorganic material, a single material, or a composite material, but must be chemically stable at least with respect to the dispersion medium and have ion conductivity in the film thickness direction. Preferably, it is a high molecular compound, and may have an ion dissociation group in the molecule. An ion dissociation group is a group (an alkylene oxide group, an alkylene imine group, or the like) that can dissociate a group that can be ionized (hydroxyl group, carboxyl group, sulfonic acid group, phosphoric acid group, etc.) or a dissociative substance (electrolyte salt, etc.). ). More specifically, polyacrylic acid, polystyrene sulfonic acid, polyethylene oxide and polypropylene oxide, and derivatives and cross-linked products thereof can be used. In the case where a self-holding film cannot be formed alone, for example, it can be used while being held in a porous film.

  The porous membrane used in the present invention can be used as long as it is stable against the dispersion medium, but must be capable of containing (holding) an ion conductive substance. In the case of using a porous membrane, the ion conductive material may use various forms of ion conductive materials such as liquid, gel, and solid. The ion conductive material may be retained in the porous film after laminating insoluble particles in the dispersion medium used in the device and / or the device manufacturing method of the present invention, or may be previously applied to the porous film. After holding the ion conductive material, insoluble particles may be laminated in the dispersion medium. As specific examples of the porous membrane according to the present invention, a porous body made of polymer fibers such as glass fiber, polyester, Teflon (registered trademark), polyflon, polyethylene, polypropylene, polyimide, and the like, and glass fibers and those polymer fibers were mixed. Products, foams of the above polymers, and the like can be used.

(Application examples)
The production method of the present invention can be applied to various electrochemical devices utilizing a catalytic reaction by using various materials as particles insoluble in a dispersion medium. An application example thereof is a fuel cell.

  Hereinafter, the present invention will be described by taking a fuel cell as a specific example. FIG. 9 is an example of a fuel cell using a proton conducting electrolyte.

  As a basic component, an ion conductive layer (proton conductor in the figure) is present at the center, and an anode catalyst layer and a cathode catalyst layer are arranged on both sides thereof. Fuel (hydrogen, alcohol, etc.) serving as a proton source is supplied to the anode side as fuel, and hydrogen ions are generated from the fuel by the catalytic action in the anode. At this time, the generated electrons flow out to the external circuit. The generated hydrogen ions propagate through the proton conductor and reach the anode. By supplying an oxidant (air, oxygen, etc.) to the anode, hydrogen ions, oxygen, and electrons flowing through the external circuit react to generate water. This can be expressed as a reaction:

Anode reaction; H ₂ → 2H ⁺ + 2e− (in the case of hydrogen fuel)
Cathode reaction; 2H ⁺ + 1 / 2O ₂ + 2e ⁻ → H ₂ O
All reactions; H ₂ + 1 / 2O ₂ → H ₂ O

  In a fuel cell, since it is necessary to laminate | stack a catalyst layer on both sides of an ion conduction layer, it can produce also by repeating the manufacturing method of this invention twice on the front and back of an ion conductive film. At this time, different particles can be laminated on the anode side and the cathode side. When the same particles are laminated on the anode side and the cathode side, a catalyst layer is formed on two portions of one side of the ion conductive layer by irradiating light on two portions by a method such as a photomask or laser drawing on the optical semiconductor. Since it can be laminated, it can also be used as a functional member of a fuel cell by folding the ion conductive membrane inside (catalyst layer outside) so that the catalyst layers overlap.

  The production method of the present invention, particularly the method using an optical semiconductor, can form catalyst layers in a plurality of regions in one step within the same plane of an ion conductive membrane or a porous membrane as described above (a plurality of fuels). It is possible to form a battery element), which is a highly productive method. In addition, by using each of the portions where the catalyst layers are formed in a plurality of regions on the front and back sides of the ion conductive layer in this manner as fuel cell elements (in parallel and / or in series connection), high voltage / high output Therefore, it is suitable for manufacturing a thin fuel cell.

  A fuel cell using hydrogen gas as a fuel generally has a high output density, and a solid polymer electrolyte fuel cell using hydrogen fuel is expected as a power source for a high-speed moving body such as an electric vehicle or a distributed power source. In order to activate the electrochemical reaction in the electrode, a platinum catalyst is mostly used in the electrode, and hydrogen ions (protons) generated at the anode are conducted to the cathode through the ion conductive layer. However, there are still drawbacks in the storage and transportation of fuel hydrogen, the method of fuel supply, and the like, and they are not suitable for personal use especially for the purpose of power supplies for electronic devices such as small portable devices.

  The fuel cell of the present invention is suitable depending on the type of catalyst, but basically any fuel can be used. However, it is preferable to use a fuel that is excellent in volume and weight energy density. Since the fuel is usually stored in a finite space (such as a container), it has only a fixed volume. Therefore, in the practice of the present invention, it is preferable to use a fuel excellent in volume and weight energy density. In particular, a fuel excellent in volume energy density is preferable. Therefore, gaseous fuel is not preferable because it is inferior in volumetric energy density, and liquid fuel and solid fuel are preferable.

  This is because, for example, the number of electrons that can be extracted from one molecule of oxidation reaction is 2 if it is hydrogen, 6 if it is methanol, and 12 if it is ethanol. The values are 96500 × 2C, 96500 × 6C, and 96500 × 12C. Considering each density and molecular weight, when converted to the amount of coulomb per cc, the energy density is about 9 C / cc for hydrogen, about 14400 C / cc for methanol, and 15200 C / cc for ethanol. Hydrogen, which is a gas at normal pressure, has an extremely low energy density per unit volume. Methanol and ethanol each require one molecule and three molecules of water for the oxidation reaction (the following formula), but it is clear that liquid fuel is excellent even when this is added.

CH ₃ OH + H ₂ O → 6H ⁺ + 6e ⁻ + CO ₂
C ₂ H ₅ OH + 3H ₂ O → 12H ⁺ + 12e ⁻ + 2CO ₂

  Although it is possible to use high-pressure hydrogen or liquid hydrogen, it is necessary to make the container robust, and considering the energy density contained in the container, fuel in liquid or solid state at normal temperature and pressure is excellent.

  Specifically, hydrogen, gasoline, liquid hydrocarbon, liquid alcohol, and other solid and liquid fuels stored in hydrogen storage alloys can be used. It is better to use alcohol fuel because it is superior. By using alcohol fuel, the driving time of the fuel cell can be improved. Among these, it is preferable to use alcohol having 4 or less carbon atoms.

  More preferably, ethanol is used because it is highly safe and biosynthetic is possible (environmental aspect). Since the fuel cell of such a form is excellent in volume energy density and weight energy density, it is particularly preferable when used for a portable device to be carried.

  Instead of direct oxidation of liquid fuel, a so-called reformed fuel type in which liquid fuel such as liquefied natural gas (LNG) or methane gas or liquid fuel such as methanol is reformed to obtain hydrogen to be used as fuel for fuel cells However, in this case, carbon monoxide (CO) present in the hydrogen gas fuel obtained by reforming the raw fuel, and other problems that impair the function of the fuel cell due to other trace impurities (Catalyst poisoning). The problem of catalytic CO poisoning has been studied, and a platinum-ruthenium (Pt—Ru) alloy catalyst is proposed as a catalyst for reducing this problem. However, in many cases, CO poisoning cannot explain the factors that inhibit the catalytic chemical reaction in the anodic oxidation of methanol and ethanol in solution. This is because the oxidation reaction of methanol or ethanol is oxidized through a number of elementary reactions that cannot be compared with hydrogen or CO.

  According to the present invention, a catalyst comprising "platinum and Ru or Ir" is preferred for the oxidation of methanol, and "at least one metal selected from the group consisting of platinum and ruthenium, iridium, tungsten and tin" for the oxidation of ethanol. Preferably, the catalyst component contains three or more of these metals. Although the reason why these catalysts are suitable is not clear, it is considered that the present catalyst contributes to the promotion of the progress of complex reactant processes of methanol and ethanol.

Example 1
An optical semiconductor composed of an amorphous selenium layer was produced by vacuum deposition on a 10 cm × 10 cm Al substrate (hereinafter abbreviated as substrate 1). Al was grounded and positively charged on the amorphous selenium layer with a charging potential (scorotron) at a charging potential of about 1 kV (FIG. 12 (1)). The halogen lamp light was irradiated through the glass photomask shown in FIG. 10, and the charged potential of the irradiated portion was attenuated (FIG. 12 (2)) (hereinafter abbreviated as latent image carrier 1).

  Separately from this, a liquid in which platinum was supported on a mixed liquid of isopar and alcohol (US Electrochem Co., Ltd.) was added to 5.5 wt% and perfluorosulfonic acid was added to 2 wt%, and a dispersion treatment was performed. Prepared (hereinafter, this liquid is abbreviated as Dispersion 1).

  The dispersion 1 was applied onto the amorphous selenium layer of the latent image carrier 1 while rotating a negatively charged conductive rubber roller (FIG. 12 (3)). Thereafter, an ion conductive membrane (manufactured by DuPont; trademark Nafion) is inserted between the latent image carrier 1 and a positively charged positively charged roller, and the positively charged roller is rotated and discharged from the opposite side of the insertion site. The transferred ion conductive film was peeled off from the latent image carrier 1 to obtain a transfer body (FIGS. 12 (4) and (5)) (hereinafter abbreviated as semi-transfer body 1). Thus, particles mainly composed of carbon carrying platinum were laminated on the semi-transfer body 1 (hereinafter, this laminated structure is abbreviated as a laminated film). In addition, the shape of the laminated film after drying the semi-transfer body 1 substantially coincided with the shape of the glass photomask (FIG. 12 (5)).

  Further, the transfer body 1 was obtained by performing the steps of FIGS. 12 (1) to 12 (5) on the back surface of the transfer body 1 so as to form substantially the same laminated film with the ion conductive film of the transfer body 1 interposed therebetween.

  Separately, two carbon fluid passage bodies shown in FIG. 11 were prepared. The transfer body 1 is sandwiched between the fluid passage bodies (adjusted so that the fluid passage is at the center of the catalyst transfer position), and this is installed between two metal plates that can be tightened with 16 bolts. The bolt was tightened to obtain an electrochemical device (hereinafter abbreviated as device 1). In order to examine the function of the device 1 as an electrochemical device, when humidified hydrogen is sent to one fluid passage body of the device 1 and humidified oxygen is sent to the other, an electromotive force of 0.89 V is generated on the hydrogen side and the oxygen side. It was obtained and confirmed to function as an electrochemical device.

(Example 2)
Using the LED array having a resolution of 600 dots / inch while scanning the substrate 1 at a constant speed, the same procedure as in Example 1 was performed except that light irradiation was performed directly on the amorphous selenium layer of the substrate 1 without using a photomask. The light irradiation shape was also adjusted to be the same as in Example 1, and a semi-transfer body 1 and then a transfer body 2 were obtained. Furthermore, using the transfer body 2, an electrochemical device was produced in the same manner as in Example 1, and the device 2 was obtained. When the function of the device 2 as an electrochemical device was examined by the same method as in Example 1, the electromotive force was 0.90 V.

(Example 3)
Using the method of Example 2, a laminated film having the pattern of Example 1 was formed on one surface of the ion conductive film by light irradiation with an LED array, and a semi-transfer body 3 was obtained. Next, separately from this, carbon (supported by Electrochem Corp.) carrying platinum ruthenium in a mixed solution of isopar and alcohol was added to 5.5 wt% and perfluorosulfonic acid to 2 wt%, and dispersion treatment was performed. (Hereinafter abbreviated as Dispersion 3).

  Using the dispersion 3, platinum ruthenium-supported carbon was transferred to the back surface of the portion where the platinum-supported carbon of the semi-transfer body 3 was laminated in the same manner as in Example 2 to obtain a transfer body 3. A 3% methanol aqueous solution was supplied to the platinum ruthenium side and air was supplied to the platinum side of the device 3 sandwiched between the two fluid passage bodies and the two metal plates as in Example 1. An electromotive force of 0.85 V was generated, and it was confirmed that the device 3 functions as an electrochemical device.

It is a figure which shows structures, such as a conventional fuel cell and an electrolysis device. FIG. 2 is a plan view of the fluid passage body shown in FIG. 1 and a cross-sectional view taken along line A-A ′ of the plan view. It is a composition conceptual diagram of the electrochemical device by the present invention. It is a figure which shows the example of formation of the catalyst layer used for this invention. FIG. 5 is a plan view of a fluid passage body used in FIG. 4 and a cross-sectional view taken along line A-A ′ of the plan view. It is a figure which shows the other example of the fluid channel | path body shown in FIG. It is a figure which shows the example of formation of the catalyst layer and the electron conductive layer by the 2nd Example of this invention. It is a figure which shows the method of producing the catalyst layer and electron conduction layer of this invention. It is a figure which shows the concept which forms the electrostatic development by this invention. It is an example of the fuel cell using a proton conduction type electrolyte. It is an example of a glassy photomask. It is a top view concerning an example of the fluid passage made from carbon, and a sectional view which met a line A-A 'of this top view. It is another figure which shows the concept which forms the electrostatic development by this invention.

Claims (19)

A fluid passage body having a fluid passage portion through which fluid passes;
A catalyst layer having a boundary surface and containing a catalyst component; and an ion conducting layer;
With
The catalyst layer is laminated on each principal surface of the ion conductive layer so as to be in contact with the surface opposite to the boundary surface, and the fluid passage body is laminated on the ion conductive layer, respectively. In
The electrochemical device, wherein the catalyst layer is in contact with the fluid passage portion.   2. The electrochemical device according to claim 1, wherein the fluid passage body includes an electron conducting portion in a portion other than the fluid passage portion.   The electrochemical device according to claim 1, wherein each of the catalyst layers is substantially opposed to the ion conductive layer.   4. The electrochemical device according to claim 2, wherein each of the electron conducting portions is substantially opposed to the ion conducting layer.   The electrochemical device according to any one of claims 1 to 4, wherein the fluid passage portion is non-conductive.   The electrochemical device according to any one of claims 1 to 5, wherein the catalyst component contains platinum.   The electrochemical device according to claim 6, wherein the catalyst component further contains ruthenium or iridium.   The electrochemical device according to claim 7, wherein the catalyst component further contains at least one metal selected from the group consisting of ruthenium, iridium, tungsten, and tin.   The electrochemical device according to claim 8, wherein the catalyst component contains three or more metals. Forming an electrostatic latent image on a carrier;
Electrostatically contacting the electrostatic latent image with the catalyst component; and electrostatically transferring the catalyst component to the ion conductive layer;
A method for producing an electrochemical device, comprising: Forming an electrostatic latent image on the electrostatic carrier;
Electrostatically contacting the electrostatic latent image with a catalyst component containing an electron conducting component; and electrostatically transferring the catalyst component to the ion conducting layer;
A method for producing an electrochemical device, comprising:   12. The method for producing an electrochemical device according to claim 10, wherein the step of forming the electrostatic latent image is performed by collective irradiation, drawing irradiation, or linear irradiation.   The formation method according to claim 10, wherein the catalyst component contains a polymer compound having binding properties.   The method according to claim 13, wherein the polymer compound is an ion conductive polymer or a fluorine-based polymer.   15. The forming method according to claim 11, wherein the electron conductive component is a material mainly composed of carbon.   An electrochemical device manufactured using the method according to any one of claims 10 to 15.   A fuel cell comprising the electrochemical device according to any one of claims 1 to 7 and 16.   The fuel cell according to claim 17, which is driven by ethanol.   A portable device comprising the fuel cell according to claim 15.

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