JP2004281417A - Fuel cell power generator and device using it - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell power generator suitable for a portable power source without necessitating a separator and an auxiliary device for fluid supply or the like. <P>SOLUTION: In the fuel cell power generation in which an anode oxidizing fuel and a cathode reducing oxygen are formed through an electrolyte film and liquid is used as fuel, more than one of vent holes are formed in the wall surface of a fuel container and a plurality of unit cells each having the anode and the cathode are mounted thereon, and the unit cells are electrically connected to one another. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a fuel cell power generator including an anode, an electrolyte membrane, a cathode, and a diffusion layer, in which fuel is oxidized at the anode and oxygen is reduced at the cathode, and in particular, a liquid fuel such as methanol is used as the fuel. The present invention relates to a small portable power supply and a portable electronic device using the same.

  Recent advances in electronic technology have reduced the size of telephones, book-type personal computers, audiovisual devices, mobile information terminal devices, and the like, and are rapidly spreading as portable electronic devices.

  Conventionally, such a portable electronic device is a system driven by a secondary battery, and the appearance of a new type of secondary battery from a sealed lead battery to a Ni / Cd battery, a Ni / hydrogen battery, and a Li-ion battery, and a reduction in size and weight, and an increase in the size of the battery. It has been developed by energy density. In any of the secondary batteries, a battery active material has been developed to increase the energy density and a high-capacity battery structure has been developed, and efforts have been made to realize a power source that can be used for a longer time with one charge.

  However, secondary batteries must be charged after a certain amount of power is used, and charging equipment and a relatively long charging time are required. Therefore, many problems remain for long-term continuous operation of portable electronic devices. Have been. In the future, portable electronic devices are going to require power supplies with higher output density and higher energy density, that is, power supplies with longer continuous use time, in response to the increasing amount of information and the speeding up, The need for small generators (micro-generators) that do not require is increasing.

  A fuel cell power supply can be considered to meet such demands. Fuel cells convert the chemical energy of fuel directly into electrical energy electrochemically, and do not require a power unit such as a generator using an internal combustion engine such as a normal engine generator. Is highly feasible. Further, since the fuel cell continues power generation as long as refueling is performed, it is not necessary to temporarily stop the operation of the device for charging as in the case of a normal secondary battery.

  Under such demands, a polymer electrolyte fuel cell (PEFC) that oxidizes hydrogen gas at an anode using an electrolyte membrane of a perfluorocarbon sulfonic acid-based resin and reduces oxygen at a cathode to generate power. Are known as batteries with high power density.

  In order to further reduce the size of this fuel cell, for example, as shown in Japanese Patent Application Laid-Open No. 9-223507, an assembly of a cylindrical cell in which an anode and a cathode are provided on the inner surface and the outer surface of a hollow fiber electrolyte is provided. There has been proposed a small-sized PEFC power generator for supplying hydrogen gas and air to the inside and outside of a cylinder, respectively. However, when applied to the power supply of a portable electronic device, since the fuel is hydrogen gas, the volume energy density of the fuel is low, and the volume of the fuel tank needs to be increased.

  In addition, this system requires auxiliary equipment such as a device that feeds fuel gas or oxidizing gas (air, etc.) to the power generation device, and a device that humidifies the electrolyte membrane to maintain battery performance. This is not enough for miniaturization.

  In order to increase the volume energy density of the fuel, it is effective to use a liquid fuel and to eliminate the auxiliary equipment for supplying the fuel or the oxidant to the battery and to adopt a simple configuration. As such a device, a direct methanol fuel cell (DMFC) using methanol and water as fuel is proposed in JP-A-2000-268835 and JP-A-2000-268636.

  In this power generation device, an anode is arranged on the outer wall side of a liquid fuel container via a material for supplying liquid fuel by capillary force so as to be in contact with the material, and a solid polymer electrolyte membrane and a cathode are sequentially joined. Be composed.

  Since oxygen is supplied by diffusion to the outer surface of the cathode that comes into contact with the outside air, this type of power generator has a simple configuration that does not require auxiliary equipment for supplying fuel and oxidizing gas, and multiple batteries are connected in series. When combined, it is characterized in that only electrical connection is required, and no unit battery connecting part called a separator is required.

  However, since the output voltage of a DMFC under load is 0.3 to 0.4 V per unit battery, a plurality of fuel tanks provided with a fuel cell are used to cope with the voltage required by portable electronic devices. Therefore, it is necessary to connect each battery in series. In addition, in order to reduce the size of the power generation device, the number of series-connected cells increases, and the capacity of the fuel container per unit cell must be reduced, and the number of fuel containers is dispersed according to the number of series. Is left.

  Further, with the operation of the acidic electrolyte fuel cell, continuous use becomes difficult unless a mechanism for discharging the gas generated by the oxidation reaction of the anode in the liquid fuel tank is realized.

  An object of the present invention is to provide a fuel cell power generation device that can easily continue power generation by replenishing fuel without being charged every time a certain amount of power is consumed as in a secondary battery as power is used. Another object of the present invention is to provide a system using a fuel having a high volume energy density.

  Further, in order to obtain a predetermined voltage, a unit cell including an anode, an electrolyte membrane, and a cathode is stacked via a separator having a conductive fluid passage structure to constitute a fuel cell power generator, and a fuel, an oxidant Instead of a conventional fuel cell with a fluid supply mechanism for forcibly flowing gas, it is a small fuel cell that does not require a separator, does not have auxiliary equipment such as a fluid supply mechanism, and the power supply Even if it is possible, it is possible to supply liquid fuel to each unit cell, and it is suitable for portable use that has a function of discharging gas generated by oxidation at the anode from the fuel container, and a compact power supply, and a portable electronic device using the same. To provide equipment.

The gist of the present invention that achieves the above object is as follows. An anode for oxidizing fuel and a cathode for reducing oxygen are formed through an electrolyte membrane, and in a fuel cell power generator using liquid as fuel,
A fuel cell is provided with one or more ventilation holes on the wall thereof, and a plurality of cells having an electrolyte membrane, an anode and a cathode are mounted on the wall of the fuel container, and the respective cells are electrically connected. I do.

  It is characterized in that a plurality of single cells each comprising an anode, an electrolyte membrane, and a cathode are provided on an outer wall surface of a container for storing liquid fuel as a platform.

  In particular, when the required current is relatively small and a high voltage is required, a plurality of cells composed of an anode, an electrolyte membrane, and a cathode are arranged on the outer peripheral surface of the container for storing the liquid fuel, and each cell is Are connected in series or in a combination of series and parallel with a conductive interconnector, so that a higher voltage can be achieved.

  The fuel is supplied without any auxiliary equipment for forcing each unit cell by connecting the fuel container as a platform. At this time, the refueling is further stabilized by holding the liquid fuel in the liquid fuel container and filling the liquid fuel with a material that is sucked up by capillary force.

  On the other hand, each cell having a power generation unit on the outer wall surface of the liquid fuel container is supplied with an oxidant by diffusion of oxygen in the air. By using an aqueous solution of methanol or the like having a high volume energy density as a liquid fuel, power generation can be continued for a longer time than when hydrogen gas is used as a fuel in a storage container having the same volume.

  A power supply comprising a fuel cell according to the present invention is used as a battery charger provided for charging a portable telephone, a portable personal computer, a portable audio device, a visual device, and other portable information terminals equipped with a secondary battery at rest. Or, by using a built-in power supply directly without mounting a secondary battery, these electronic devices can be used for a long time, and can be used continuously by refueling.

  According to the present invention, a container for storing liquid fuel is used as a platform, a fuel cell is mounted on a wall of the platform, and the cells are electrically connected in series or in a combination of series and parallel. By mounting a fuel cell with the fuel container as a platform and providing a liquid fuel holding material in the container, the liquid fuel is sucked up by capillary force and supplied to each fuel cell.

  In each fuel cell having a power generation unit on the outer peripheral surface, oxygen (oxidant) in the air is supplied through diffusion holes. Thus, a fuel cell having a simple system that does not require auxiliary equipment for supplying fuel and oxidant can be realized.

  In addition, by using a methanol solution with a high volume energy density as the liquid fuel, power generation can be continued for a longer time per liter than when hydrogen gas is used as the fuel. It is possible to obtain a continuous power generator that does not require charging as described above.

  Furthermore, by mounting fuel cells on multiple walls of the fuel container and providing multiple vents with gas-liquid separation functions on those walls, a power generation device that can continue stable power generation in any position is realized. it can.

  Embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 shows an example of a sectional structure of a liquid fuel container according to the present invention.

  A plurality of fuel cell mounting portions 2 having an insulating surface are provided on the outer wall surface of the fuel container 1. The container wall of the battery mounting portion 2 has a mesh structure, a porous layer, Alternatively, the diffusion hole 3 on the slit is formed.

  The anode interconnector 4 is formed on the surface of the fuel cell mounting portion 2 by applying and baking a material having corrosion resistance and conductivity for electrical connection with an adjacent fuel cell. The interconnector 4 has a network structure, a porous layer or a diffusion hole structure on a slit, which is sufficient for liquid fuel to permeate.

  An electrochemically inert liquid fuel wicking material 5 is mounted on the inner wall surface of the fuel container 1. The fuel cells mounted on the wall surface of the fuel container are electrically connected in series or in a combination of series and parallel, and anode and cathode fuel cell terminals 6 to be taken out of the power generator are provided.

  In the unit cell, as shown in FIG. 2, an anode layer 22 and a cathode layer 23 are integrally joined to both surfaces of a solid electrolyte membrane 21 in advance to form an electrolyte membrane / electrode assembly (MEA; Membrane Electrode Assembly). As shown in FIG. 3, the fuel cell fixing plate 8 for fixing the fuel cell to the fuel container uses an electrically insulating plate, and a portion in contact with the fuel cell diffuses air to supply the fuel cell to the fuel cell. And a diffusion layer 3 having a mesh-like structure, a porous layer or a slit shape, which is sufficient to be connected to the anode-side interconnector 4 of the adjacent fuel cell. The cathode current collector plate 7 is provided.

  The portion of the cathode current collector 7 which is in contact with the fuel cell has diffusion holes 3 sufficient to supply air. During power generation, the fuel is oxidized in the fuel container 1 to generate carbon dioxide gas, which has a liquid-impermeable gas-liquid separation function having a cross-sectional structure as shown in FIG. The fuel is discharged to the outside of the fuel container through the vent hole 15.

  The ventilation hole 15 includes a ventilation pipe 51 and a screw-type ventilation lid 52, and has a structure in which a water-repellent, porous gas-liquid separation membrane 50 is fixed with the ventilation lid. The ventilation holes 15 are arranged on a plurality of surfaces of the fuel container 1 such that one or more ventilation holes are in a ventilation state regardless of the posture of the fuel cell power generator, as shown in the sectional structure of FIG. Is done.

  As shown in FIG. 5, the assembly of the fuel cell power generator is performed by installing a gasket 10, a MEA 9, a gasket 10 on a fuel cell mounting portion of a fuel container, and a polytetrafluorocarbon cloth to facilitate diffusion of air and generated water. The porous diffusion layer 11 in which fluoroethylene is finely dispersed is laminated in this order, and the fuel cell fixing plate 8 having the vent hole mounting holes 19 is fixed to the fuel container 1 by a method such as bonding or screwing. In this fixing process, the cathode current collector contacts and is electrically connected to the anode interconnector of the adjacent fuel cell, and the start point and the end point are taken out as the output terminal 16.

  In operation of the fuel cell power generator, the lid of the ventilation hole 15 also serving as a fuel supply hole shown in FIG. 4B is removed, and a liquid fuel, for example, an aqueous methanol solution is filled from here. The filled methanol aqueous solution permeates the cell mounted on the lower surface of the container and is stably supplied to the anode, and the cell mounted on the upper surface is sucked up from the suction material and supplied stably to the anode. Will be.

  Since the cathode of each cell is in contact with the outside air through a mesh-like, porous or through-hole in the slit, the cathode current collector and the cathode diffusion layer, oxygen in the air is diffused and supplied, and water generated by power generation is generated. Are eliminated by diffusion.

  FIG. 6 shows the appearance of the fuel cell power generation device of this example. The fuel container 1 having the ventilation hole 15 functions as a structure of the power generation device, and a plurality of cells 13 are fixed to a wall surface of the fuel container 1 with the fuel cell fixing plate 8, and both ends electrically connected in series as output terminals 16. It has a structure to take it out.

  During power generation, fuel is oxidized on the anode side, that is, in the fuel container, and carbon dioxide gas is generated. The carbon dioxide gas is discharged to the outside of the fuel container through a liquid-impermeable gas-liquid separation vent. Is discharged. A plurality of such vents should be provided on the wall surface of the fuel container, and should be arranged at a position where one or more vents are not blocked by the fuel liquid regardless of the posture of the fuel container during power generation. The feature is that a stable power generation operation is guaranteed.

  The fuel power generation device according to the present invention does not require a facility for forcibly supplying a fuel, an oxidizing gas, or the like, only a single cell is mounted on the container wall, and a plurality of cells are stacked via a separator. Since it does not have a structure and has sufficient heat radiation, there is no need to provide a forced cooling mechanism. Therefore, it is possible to provide a structure with a small number of components, which has no power loss of auxiliary equipment and does not require a conductive separator for lamination.

  In a fuel cell using an aqueous methanol solution as a fuel, power is generated in such a manner that chemical energy of methanol is directly converted into electrical energy by an electrochemical reaction described below.

On the anode electrode side, the supplied aqueous methanol solution reacts according to the equation (1) and dissociates into carbon dioxide, hydrogen ions and electrons.
[Formula 1]
CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)
The generated hydrogen ions move from the anode to the cathode in the electrolyte membrane, and the oxygen gas diffused from the air on the cathode electrode reacts with the electrons on the electrode according to the equation (2) to generate water. .
[Formula 2]
6H ⁺ + 3 / 2O ₂ + 6e ⁻ → 3H ₂ O (2)
Therefore, as shown in equation (3), the entire chemical reaction associated with power generation oxidizes methanol with oxygen to produce carbon dioxide gas and water, and the chemical reaction equation is formally the same as that of methanol flame combustion.
[Formula 3]
CH ₃ OH + 3 / 2O ₂ → CO ₂ + 3H ₂ O (3)
The open circuit voltage of the unit cell is approximately 1.2 V near room temperature, but is substantially 0.85 to 1.0 V due to the effect of fuel permeating the electrolyte membrane, and is not particularly limited. The voltage under a practical load operation is selected to be a load current density in a range of about 0.3 to 0.6 V. Therefore, when actually used as a power supply, a plurality of unit batteries are used in series so that a predetermined voltage can be obtained according to the requirements of the load equipment. Although the output current density of the unit cell varies depending on the electrode catalyst, the electrode structure, and other factors, the unit is designed so that the power generation unit area of the unit cell is effectively selected to obtain a predetermined current.

  The support constituting the fuel cell power generator according to the present invention is characterized by a fuel container for containing a liquid fuel, and a single cell is required to be compact even if its cross-sectional shape is square, circular or other. There is no particular limitation as long as it can be mounted in a number. However, in order to compactly load a single cell into a predetermined volume, a cylindrical or square shape has good mounting efficiency, and it can be said that the shape is preferable in view of workability for mounting the fuel cell power generation unit.

  The material of the support is not particularly limited as long as it is electrochemically inert, is thin and has sufficient strength in the environment of use and durability and corrosion resistance. For example, polyethylene, polypropylene, polyethylene terephthalate, vinyl chloride, polyacrylic resin, other engineering resins, electrically insulating materials reinforced with various fillers, or carbon materials with excellent corrosion resistance in battery operating atmosphere , Stainless steel, or ordinary iron, nickel, copper, aluminum, or alloys thereof in which the surface is subjected to corrosion resistance and electrical insulation. In any case, the material is not particularly limited as long as it is a material that supports the shape, has corrosion resistance, and is electrochemically inert.

  The interior of the fuel cell support is used as a fuel storage and transport space, but the wicking material that fills the interior of the tubular support and stabilizes the fuel supply has a small contact angle with the aqueous methanol solution and is electrochemically Any material may be used as long as it is inert and has corrosion resistance, and powder or a fibrous material may be used. For example, fibers such as glass, alumina, silica-alumina, silica, non-graphitic carbon, and cellulose, and water-absorbing polymer fibers are materials having a low packing density and excellent methanol aqueous solution retention.

  As the anode catalyst constituting the power generation unit, a catalyst in which platinum and ruthenium or platinum / ruthenium alloy fine particles are dispersed and supported on a carbon-based powder carrier, and a cathode catalyst in which platinum fine particles are dispersed and supported on a carbon-based carrier are easily used. It is a material that can be manufactured. However, the anode and cathode catalysts of the fuel cell of the present invention are not particularly limited as long as they are used in ordinary direct methanol fuel cells. It is preferable to use a catalyst obtained by adding a third component selected from iron, tin, rare earth element and the like to the above-mentioned noble metal component.

  As the electrolyte membrane, a membrane exhibiting hydrogen ion conductivity is used without limitation. Typical materials are sulfonated or alkylene sulfonated fluorine-based polymers such as perfluorocarbon sulfonic acid resins and polyperfluorostyrene sulfonic acid resins, and polystyrenes, polysulfones, polyether sulfones, and polyethers. Ether sulfones, polyether ether ketones, and other materials obtained by sulfonating hydrocarbon polymers can be used.

  Materials having a low methanol permeability in these electrolyte membranes are preferable materials because they can use a high fuel utilization rate and do not cause a decrease in cell voltage due to fuel crossover. Can be operated at temperature. In addition, hydrogen ion conductive inorganic substances such as tungsten oxide hydrate, zirconium oxide hydrate, tin oxide hydrate, silicotungstic acid, silicomolybdic acid, tungstophosphoric acid, and molybdophosphoric acid are used as heat-resistant resins. By using a micro-dispersed composite electrolyte membrane or the like, a fuel cell that can be operated up to a higher temperature range can be obtained.

  In any case, when an electrolyte membrane having high hydrogen ion conductivity and low methanol permeability is used, the utilization rate of fuel is increased, so that the compactness and long-time power generation, which are the effects of the present invention, are achieved at a higher level. be able to.

  The above-mentioned hydrated acidic electrolyte membrane generally causes deformation of the membrane due to swelling between when dry and when wet, and sometimes the mechanical strength is insufficient when a membrane having sufficiently high ionic conductivity is used. In such a case, using fibers having excellent mechanical strength, durability, and heat resistance as a core material in the form of a nonwoven fabric or a woven fabric, or adding or reinforcing these fibers as fillers during the production of an electrolyte membrane requires a battery. This is an effective way to increase performance reliability. Further, in order to reduce the fuel permeability of the electrolyte membrane, a membrane in which polybenzimidazoles are doped with sulfuric acid, phosphoric acid, sulfonic acids or phosphonic acids can be used.

  As another example instead of the above, the power generation unit constituting the unit cell can be manufactured by the following method, for example. That is, (1) a step of applying a conductive interconnector to the electrically insulating outer peripheral surface of the liquid fuel container to make the wall surface of the anode junction porous by a through hole, and (2) volatilizing the anode catalyst and the electrolyte resin in advance. Adding a solution dissolved in a neutral organic solvent as a binder, dispersing the solution into a paste, applying a constant thickness of 10 to 50 μm to the cut porous portion of the liquid fuel storage container to form an electrode, (3) a step of applying a sealing gasket to the cut portion by masking the anode coating portion and joining the gasket to the fuel container; (4) After that, an electrolyte solution previously dissolved in a volatile organic solvent is brought into contact with the anode electrode to cut the cut portion. (5) Next, a solution obtained by previously dissolving the cathode catalyst and the electrolyte membrane in a volatile organic solvent is kneaded as a binder. A step of applying the paste into a constant thickness of 10 to 50 μm on an electrolyte membrane to form an electrode; (6) further, a carbon-based powder and a predetermined amount of a water-repellent dispersion material, A single cell is produced through a process in which an aqueous dispersion of polytetrafluoroethylene fine particles is made into a paste, applied to the cut portions so as to be bonded to the surface of the cathode electrode, and a diffusion layer is formed. At this time, in the step (4), it is important that the electrolyte membrane portion be larger than the cathode area, and that the gasket and the electrolyte membrane be closely adhered or sealed by bonding using an adhesive.

  A conductive porous material or net is attached to the cathode-side diffusion layer portion of the obtained cell to form a cathode current collector, electrically connected to an interconnector from an adjacent cell, and both ends connected in series. Remove the terminal from. Providing a diffusion layer on the cathode side is an effective method for preventing flooding of water generated during fuel cell operation.

  In producing the diffusion layer, when the water-repellent aqueous dispersion material contains a surfactant which is a catalyst poison component of a platinum catalyst or a platinum-ruthenium alloy catalyst, for example, such as carbon fiber On one side of the conductive woven fabric surface, a carbon-based powder and a predetermined amount of a water-repellent dispersion material, for example, an aqueous dispersion of polytetrafluoroethylene fine particles are applied in paste form, and the temperature at which the surfactant is decomposed in advance It is effective to mount the coated surface so as to be in contact with the cathode after baking with, and use a carbon fiber woven fabric as a cathode current collector.

  In any case, if the unit cell is a method in which an anode, an electrolyte membrane, a cathode, and a diffusion layer are stacked in this order on a support surface and a sufficient reaction interface is formed between the anode / electrolyte membrane and the cathode / electrolyte membrane, the manufacturing method There are no special restrictions. Further, when forming a cathode, a predetermined amount of a water-repellent dispersion material, for example, polytetrafluoroethylene fine particles are added to a solution in which a cathode catalyst, an electrolyte membrane and an electrolyte are previously dissolved in a volatile organic solvent, and the paste is formed. By coating, a battery that does not require a diffusion layer can be formed.

  Using the liquid fuel container as the platform of the present invention as a platform, a plurality of cells composed of an anode, an electrolyte membrane, and a cathode are produced on the outer peripheral surface thereof, and each cell is connected in series by a conductive interconnector. Thus, a higher voltage can be achieved. In addition, operation can be performed without using auxiliary equipment for forcibly cooling the fuel cell without using auxiliary equipment for forcibly supplying fuel or oxidant, and a methanol aqueous solution with a high volume energy density can be used as the liquid fuel. Thus, a small power supply that can continue power generation for a long time can be realized.

  This small power source can be built in and driven as a power source for a mobile phone, a book-type personal computer, a portable video camera, or the like, and can be used continuously for a long time by sequentially replenishing the prepared fuel in advance. It becomes possible.

  Also, for the purpose of significantly reducing the frequency of refueling than in the case described above, this small power supply, for example, a secondary battery-equipped mobile phone, a book-type personal computer or a portable video camera charger, It is effective to use it as a battery charger by attaching it to a part of those storage cases. In this case, when the portable electronic device is used, it is taken out of the storage case and driven by the secondary battery, and when not in use, it is stored in the case, so that the small fuel cell power generation device built in the case is connected via the charger and the secondary battery is connected. Charge the next battery. By doing so, the capacity of the fuel tank can be increased, and the frequency of refueling can be significantly reduced.

Next, the present invention will be described based on examples.
[Comparative Example 1]
FIG. 7 is a sectional view showing a separator structure based on a conventional structure. FIG. 7A shows an in-plane structure and a vertical cross section, and FIG. 7B shows another in-plane structure and a cross section. FIG. 8 shows a battery stack configuration, and FIG. 9 shows a cell holder configuration. FIG. 10A shows a power supply system structure in which 18 single cells are stacked in series and a fuel container is attached, and a cross-sectional structure showing the connection between the fuel cell and the fuel container at the stack end is shown in FIG. It is shown in FIG.

  As the separator 81, a graphitized carbon plate of 16 mm width × 33 mm length × 2.5 mm thickness was used. An inner manifold 82 having a width of 10 mm and a length of 4 mm is provided at the bottom of the separator 81. As shown by a reference numeral 84 in the cross-sectional view of the separator in FIG. 7A, a 1 mm width × 0.8 mm depth × 23 mm length is provided. Are formed at intervals of 1 mm to form the rib portions 54, and a fuel supply groove connecting the manifold 82 and the upper surface of the separator 81 is provided.

  On the other hand, as shown in FIG. 7 (b) and the separator longitudinal sectional view 83, grooves of 1 mm width × 1.4 mm depth × 16 mm length are formed on the other surface of the separator at intervals of 1 mm in a direction perpendicular to the separator. An oxidant supply groove connecting the side surfaces of the separator 81 was formed by forming the rib portion 54 thus formed.

  The anode layer is composed of a catalyst powder in which platinum / ruthenium alloy fine particles having a platinum / ruthenium atomic ratio of 1/1 are dispersed and supported on a carbon support by 50 wt%, and 30 wt% perfluorocarbon sulfonic acid (trade name: Nafion 117, manufactured by DuPont) As an electrolyte, a slurry of a water / alcohol mixed solvent [a mixed solvent of water: isopropanol: normal propanol of 20:40:40 (weight ratio)] was prepared as a binder, and about 20 μm thick was formed on a polyimide film by a screen printing method. Formed on a porous membrane.

  The cathode layer is prepared by preparing a slurry of a catalyst powder in which 30 wt% of platinum fine particles are supported on a carbon carrier and a water / alcohol mixed solvent using an electrolyte as a binder, and forming a porous film having a thickness of about 25 μm on a polyimide film by a screen printing method. Formed on the membrane. The thus prepared anode porous membrane and cathode porous membrane were each cut into a 10 mm width × 20 mm length to obtain an anode layer and a cathode layer.

  Next, a manifold opening 86 was provided in Nafion 117 having a width of 16 mm × a length of 33 mm × a thickness of 50 μm as an electrolyte membrane.

  About 0.5 ml of a 5% by weight aqueous solution of Nafion 117 alcohol [a mixed solvent of 20:40:40 (weight ratio: water: isopropanol: normal propanol: manufactured by Fluka Chemika)] was infiltrated into the surface of the anode layer. And dried at 80 ° C. for 3 hours under a load of about 1 kg. Next, about 0.5 ml of the 5% by weight Nafion 117 alcohol aqueous solution is permeated into the surface of the cathode layer, and then joined so as to overlap with the anode layer previously joined to the electrolyte membrane. By drying at 3 ° C. for 3 hours, MEA9 was prepared.

  Next, a polyethylene terephthalate liner 92 having a thickness of 250 μm having the same size as the separator 81 and having a manifold opening 86 and a power generation unit opening 85 and a neoprene gasket 10 having a thickness of 400 μm were produced.

Next, an aqueous dispersion (Teflon Dispersion D-1: manufactured by Daikin Industries, Ltd.) of water repellent polytetrafluoroethylene fine particles is added to the carbon powder so that the weight after firing becomes 40 wt%, and the mixture is kneaded to form a paste. The resultant was applied to one side of a carbon fiber woven fabric having a thickness of about 350 μm and a porosity of 87% so as to have a thickness of about 20 μm, dried at room temperature, and fired at 270 ° C. for 3 hours to obtain a carbon sheet. Formed. The obtained sheet was cut out into the same shape as the electrode size of the MEA to prepare a diffusion layer 11. (Note) Teflon; registered trademark Next, a fuel wicking material 5 made of pulp paper and composed of a fuel electrode side groove embedding portion 88 of the separator 81 and a manifold embedding portion 87 was prepared.

As shown in FIG. 8, 14 parts of these parts are stacked in the order of the separator 81, the liquid fuel wicking material 5, the liner 92, the gasket 10, the MEA 9, the diffusion layer 11, the liner 92, and the separator 81, and about 5 kg / Pressing was performed at a pressure of ² cm ² to obtain a laminated battery 94. The laminated battery 94 is made of fluorinated rubber (Viton; manufactured by DuPont) through a SUS316 holder 105 in which the surface of the structure shown in FIG. 9 is insulated with epoxy resin (Flep; manufactured by Toray Thiokol). As shown in FIG. 10 (a), it was fastened and fixed with a fastening band 17. The fuel container 1 was made of polypropylene having a laminated cell mounting portion 103 and having a size of 33 mm in height × 85 mm in length × 65 mm in width and a side wall thickness of 2 mm.

  As shown in FIG. 10B, gas selective permeation in which a porous polytetrafluoroethylene membrane having the same structure as that shown in FIG. A vent pipe 51 having a screw cap 52 having a function is provided as a vent hole 15, and the inside of the fuel container is filled with a methanol aqueous solution 12 as fuel. The two stacked batteries thus produced have a structure as shown in FIG. 10B and are combined with the fuel cell mounting portion 103 to produce a power supply having a structure as shown in FIG. 10A.

The power source has a height of about 120 mm, a length of about 120 mm, and a width of about 65 mm, and has a power generation unit area of about 2 cm ² and a capacity of about 150 ml. A voltage of 5.7 V at an operating temperature of 50 ° C. and a load current of 0.2 A indicates a voltage of 5.7 V when power is generated by blowing a fan over the entire opening of the side wall of the power supply formed by the air electrode side groove of the separator. It was 11.8V. It is considered that this is because the supply of oxygen due to sufficient diffusion of air is insufficient in the air electrode side groove structure of the separator at the time of power supply load. The volume output density of this power supply was about 4.4 W / l without using a ventilation fan, and was about 9.2 W / l when using a ventilation fan.

  The fuel container was filled with 150 ml of a 10 wt% methanol aqueous solution, and operated at an operating temperature of 50 ° C. and a load current of 0.2 A using a blower fan. Dropped rapidly. Therefore, the volume energy density at the time of filling with the 10 wt% methanol aqueous solution fuel was 41 Wh / l when the ventilation fan was used.

This fuel cell power generation device adopts a structure in which liquid fuel is sucked up from a manifold below a stacked battery and carbon dioxide generated by oxidation of the fuel is discharged from an upper portion of the stacked battery. For this reason, there is a problem that power generation does not continue if the vehicle is upside down or rolled over during operation.
[Example 1]
FIG. 11 shows the structure of the MEA according to the present embodiment. The MEA is formed by bonding an electrolyte resin as a binder so that the anode layer 22 and the cathode layer 23 overlap on both surfaces of the electrolyte membrane 21.

  The anode layer is formed by using, as a binder, a catalyst powder in which platinum / ruthenium alloy fine particles of platinum / ruthenium (1/1) (atomic ratio) are dispersed and supported on a carbon support by 50 wt%, and a 30 wt% perfluorocarbonsulfonic acid (Nafion 117) electrolyte is used. A slurry of a water / alcohol mixed solvent (a mixed solvent of water: isopropanol: normal propanol at a weight ratio of 20:40:40) was prepared and formed into a porous film having a thickness of about 20 μm by a screen printing method.

  As the cathode layer, a slurry of a mixed solvent of water / alcohol was used to form a porous film having a thickness of about 25 μm by a screen printing method using a catalyst powder in which 30% by weight of platinum fine particles were supported on a carbon support and an electrolyte as a binder.

  The above-mentioned anode porous membrane and cathode porous membrane were cut into 10 mm width × 20 mm length, respectively, to obtain an anode layer 22 and a cathode layer 23. A 50 μm thick Nafion 117 electrolyte membrane, 20 mm wide × 30 mm long, was cut out, and a 5% by weight Nafion 117 alcohol aqueous solution (water: isopropanol: normal propanol mixed solvent: Fluka in a weight ratio of 20:40:40) was cut on the anode layer surface. After about 0.5 ml of permeate (Chemika Co., Ltd.) was infiltrated, it was joined to the center of the electrolyte membrane, and a load of about 1 kg was applied thereto, followed by drying at 80 ° C. for 3 hours.

  Next, about 0.5 ml of a 5% by weight Nafion 117 alcohol aqueous solution (manufactured by Fluka Chemika) is infiltrated into the surface of the cathode layer, and then joined so as to overlap with the anode layer 22 previously joined to the center of the electrolyte membrane. By applying a load of about 1 kg and drying at 80 ° C. for 3 hours, MEA was prepared.

  Next, an aqueous dispersion (Teflon dispersion D-1: manufactured by Daikin Industries, Ltd.) of water repellent polytetrafluoroethylene fine particles was added to the carbon powder so that the weight after firing was 40 wt%, and the paste was kneaded. It was applied on one surface of a carbon fiber woven fabric having a thickness of about 350 μm and a porosity of 87% so as to have a thickness of about 20 μm, dried at room temperature, and fired at 270 ° C. for 3 hours to form a carbon sheet. The obtained sheet was cut into the same shape as the electrode size of the MEA described above to prepare a diffusion layer.

  Next, a method of mounting a fuel cell made of MEA on the outer peripheral surface of a fuel container will be described with reference to FIG. 13 showing a cross-sectional structure of a fuel cell power generator.

  A 5 mm thick, 85% porosity glass fiber mat was mounted as a fuel wicking material 5 on the inner wall surface of a rigid vinyl chloride fuel container 1 having an outer shape of 65 mm width × 135 mm length × 25 mm height and a wall thickness of 2 mm. .

  On the outer wall surface of the fuel container 1, 18 upper and lower fuel cell mounting portions 2 each having a width of 21 mm x a length of 31 mm x a depth of 0.5 mm were provided. A slit having a width of 1 mm and a length of 10 mm was provided at intervals of 1 mm in the anode contact portion of each fuel cell mounting portion 2 to form a diffusion hole 3. The slit was filled with a glass fiber mat having a porosity of 85% so as to be in contact with the fuel wicking material 5 mounted on the inner wall surface of the fuel container.

  On the outer surface of the slit, an interconnector 4 for electrically connecting to a cathode current collector 7 of an adjacent fuel cell was provided with a nickel electroless plating layer having a thickness of about 50 μm. At the upper and lower four corners of the obtained fuel container, ventilation holes 15 having a gas-liquid separation function having the same structure as that of FIG. 4A were provided.

  Next, the fuel cell fixing plate 8 is a plate made of the same rigid vinyl chloride as the fuel container 1 and having a thickness of 2.0 mm, and has a slit provided on the mounting portion 2 of the fuel container on a surface in contact with the cathode of each fuel cell. A slit having a width of 1.0 mm and a length of 20 mm was provided as the diffusion hole 3 in a direction perpendicular to the direction of the arrow. On this fuel cell fixing plate 8, a cathode current collector plate 7 made of nickel with a slit and formed in the same shape as the slit portion so as to be connectable to the interconnector 4 of the adjacent fuel cell was fixed.

  In mounting the MEA 9 on the fuel container, the gasket 10 for sealing on both sides of the MEA 9 is disposed on the fuel cell mounting section 2, and the diffusion layer 11 is disposed on the cathode side of the MEA 9. At 8 each cell was fixed to the fuel container. At this time, the cathode current collector 7 previously arranged on the surface of the fuel cell fixing plate 8 on the cathode side electrically connects the cathode and the interconnector 4 from the anode of the adjacent fuel cell, and Are connected in series. The terminal part to which each fuel cell is connected is taken out as a battery terminal 16 from the interface between the fuel cell fixing plate 8 and the fuel container to the outside of the container. FIG. 12 shows the appearance of the fuel cell power generator according to the present embodiment.

In the fuel container 1 having the ventilation hole 15, 36 unit cells 13 on the upper and lower surfaces are mounted by the fuel cell fixing plate 8, and the output terminal 16 is provided. Thus, a 10 wt% methanol aqueous solution 12 is injected into the container as fuel from one of the vent holes 15 of the fuel container in which the fuel cell is mounted. This fuel cell was approximately 65 mm wide × 135 mm long × 29 mm high and had a fuel storage volume of about 150 ml. The power generator has a power generation area of 2 cm ² and is configured in 36 series.

  When this fuel cell power generator was operated at a temperature of 50 ° C. and a load current of 200 mA, the output voltage was 12.2 V. When a 10 wt% methanol aqueous solution is charged and operated at a load current of 200 mA, power generation can be continued for about 4.5 hours. The output density of this fuel cell power generator is about 9.6 W / l, and the volume per fuel liter is obtained. The energy density was about 50 Wh / l. In addition, even if the power generator was operated upside down or turned over during this operation, no particular change in output voltage was observed, and no increase in pressure in the fuel container was observed.

  As described above, by mounting a plurality of fuel cells on the outer wall surface of the liquid fuel container and connecting them in series with the interconnector, it is possible to realize a 12V-class high-voltage small-sized fuel cell without stacking via a separator. At this time, the anode side is brought into contact with the inside of the container and the anode with a liquid fuel wicking material, and the cathode is exposed to the outside air through the diffusion layer, so that auxiliary equipment such as a fuel feed pump and a cathode gas fan are operated. Unnecessary power supply became possible.

In particular, by installing ventilation holes with gas-liquid separation functions arranged on multiple surfaces of the fuel container, normal power generation is possible regardless of the orientation of the fuel cell, and the essential characteristics of a portable power generator can be achieved. Was.
[Comparative Example 2]
A low voltage small fuel cell power generator using a separator will be described with reference to FIG. The separator, the wicking material, the liner, the gasket, the MEA, and the diffusion layer, which are the constituent materials of the battery, are made of the same material and of the same size as in Comparative Example 1, and the laminated battery 23 is formed in the same procedure so that the unit cell becomes four cells. Was prepared. This laminated battery was inserted into the cell holder 105 in the same manner as in Comparative Example 1, and was fixed with the fastening band 17 made of fluorine-based rubber.

  The fuel container 1 has a polypropylene outer shape having a height of 33 mm × a length of 16 mm × a width of 65 mm and a side wall thickness of 2 mm. As shown in FIG. 14, a vent 15 provided with a porous polytetrafluoroethylene membrane is provided at the center of the upper surface of the fuel container 1, similarly to the structure shown in FIG.

The manufactured laminated battery 23 was combined with the fuel container 1 in the same configuration as Comparative Example 1 to form a power source. The obtained power source is provided with a fuel container 1 having a height of approximately 33 mm × a length of 82 mm × a width of 16 mm, a power generation unit area of about 2 cm ² , and a capacity of about 20 ml.

  A voltage of 0.58 V at an operating temperature of 50 ° C. and a load current of 0.2 A indicates a voltage of 0.58 V. 1.26V. It is considered that this is because the supply of oxygen due to the diffusion of air is insufficient in the air electrode side groove structure of the separator when the power is loaded. The volume output density of this power supply was about 2.7 W / l without using a ventilation fan, and was about 5.8 W / l when using a ventilation fan.

  The output voltage is about 1.26 V when the reactor is operated at an operating temperature of 50 ° C. and a load current of 0.2 A using a blower fan and filled with 20 ml of a 10 wt% methanol aqueous solution, and after continuing for about 5 hours, the voltage drops rapidly. did. Therefore, the volume energy density per 10 wt% methanol aqueous fuel liter was 29 Wh / l when a ventilation fan was used.

This fuel cell power generator has a structure in which liquid fuel is sucked up from a manifold below a stacked battery and carbon dioxide generated by oxidation of the fuel is discharged from an upper portion of the stacked battery. For this reason, there is a problem that power generation does not continue if the vehicle is upside down or overturned during operation.
[Example 2]
FIG. 15 shows a cross-sectional structure of a prismatic, low-voltage power generating apparatus using methanol as a fuel according to the present embodiment, and FIG. MEA was prepared in substantially the same manner as in Example 1. On a polyimide film of 30 mm width × 50 mm length, 50 wt% of platinum / ruthenium alloy fine particles in which platinum / ruthenium is 1/1 (atomic ratio) dispersed and supported on a carbon carrier, and 30 wt% of perfluorocarbon sulfonic acid ( Nafion 117) A porous membrane having a thickness of about 20 μm by a screen printing method using a slurry composed of a water / alcohol mixed solvent (a mixed solvent of water: isopropanol: normal propanol at a weight ratio of 20:40:40) using an electrolyte as a binder. And dried at 90 ° C. for 3 hours to form an anode porous layer.

  For the cathode porous layer, a slurry of a water / alcohol mixed solvent was prepared by using a catalyst powder in which 30% by weight of platinum fine particles were supported on a carbon support and an electrolyte was used as a binder. After being formed on the film to a thickness of about 25 μm, the film was dried at 90 ° C. for 3 hours.

  The anode porous membrane and the cathode porous membrane were cut into a size of 10 × 10 mm, respectively, to form an anode layer and a cathode layer. As the electrolyte, a sulfonated polyetherethersulfone film having a width of 28 mm × a length of 56 mm × a thickness of 50 μm at 790 g / eq was used.

  First, about 0.5 ml of a 5% by weight aqueous solution of Nafion 117 alcohol (manufactured by Fluka Chemika) was infiltrated into each surface of the eight anode layers, and this was evenly arranged on one surface of the electrolyte membrane. Apply a load of about 1 kg and dry at 80 ° C for 3 hours.

  Next, about 0.5 ml of a 5% by weight aqueous solution of Nafion 117 alcohol was infiltrated into the surface of the cathode layer, and then placed on the opposite surface of the electrolyte membrane to which the anode was joined so as to overlap the anode layer. Was applied with a load of about 1 kg and dried at 80 ° C. for 3 hours to prepare MEA.

  As shown in FIG. 16, the fuel container 1 was made of hard vinyl chloride having an outer shape of 22 mm wide × 79 mm long × 23 mm high and a wall thickness of 2 mm. As shown in FIG. 15, four fuel cell mounting portions 2 each having a width of 16 mm × a length of 16 mm × a depth of 0.5 mm were provided on the upper and lower surfaces of the fuel container 1 as shown in FIG. In the central part of the fuel cell mounting part 2, a slit having a width of 10 mm × 10 mm and a slit penetrating the inside of the fuel container 1 having a width of 1 mm × 10 mm was provided as a diffusion hole 3.

  A nickel layer having a thickness of 0.1 mm was formed on the outer surface of the mounting portion 2 as an anode-side interconnector 4 by an electroless plating method so as to be electrically connected to an adjacent fuel cell. A glass fiber mat having a thickness of 1 mm and a porosity of about 70% was attached to the inner wall of the fuel container 1 to form a fuel wicking material 5, and the inside thereof was filled with glass fibers so that the porosity was about 85%. The holding layer 18 for holding the low-density fuel was provided. At the upper and lower corners of the fuel container 1, eight vents 15 having an inner diameter of 2 mm having the structure shown in FIG.

  The fuel cell fixing plate 8 serving as a fuel cell holding plate is made of hard vinyl chloride having a width of 22 mm × 79 mm length × 1 mm as shown in FIG. A slit having a width of 1 mm and a length of 10 mm was provided in a direction orthogonal to the slit of the fuel cell mounting section 2, and vent mounting holes 19 were provided at four corners.

  A cathode collector plate 7 made of nickel and having a thickness of 0.2 mm and connected to an interconnector on the anode side of the adjacent fuel cell was attached to the fuel cell fixing plate 8.

  As shown in FIG. 16, the fuel cell of the present invention is formed by laminating a gasket 10 on the anode side made of neoprene rubber, a MEA 9, a cathode diffusion layer 11, a gasket 10 on the cathode side made of neoprene rubber, and a fuel cell fixing plate 8, in this order. The outer peripheral portion of the fixing plate was fixed to the fuel container 1 by screwing.

The anode terminal 6 and the cathode terminal 6 mounted above and below the fuel container 1 were connected in parallel to form an output terminal 16. The outer shape of the obtained fuel cell power generator is 22 mm wide × 79 mm long × 27 mm high, and is composed of 4 series × 2 parallel fuel cells having a power generation area of 1 cm ² .

  The fuel container 1 has a volume of approximately 20 ml. The fuel container is filled with a 10% aqueous methanol solution through the vent hole 15 and operated at an operating temperature of 50 ° C., and an output voltage of 1.3 V is obtained at a load current of 200 mA. Was. Further, when the fuel container was filled with 20 ml of a 10% aqueous methanol solution and a continuous power generation was performed at a load current of 200 mA, a stable voltage of about 5 hours was obtained at an output of 1.3 V. The output density of this cell was about 5.5 W / l and the volume energy density per fuel liter was about 28 Wh / l. During this operation, even when the power generator was operated upside down or turned over, no change in output voltage was observed, and no pressure increase in the fuel container was observed.

  As described above, a plurality of fuel cells are mounted on one outer wall surface of the liquid fuel container and connected in series by an interconnector, and the series cells mounted on the plurality of surfaces are arranged in parallel to be stacked via a separator. A 1.3V-class small fuel cell can be realized without the need. At this time, the anode side is brought into contact with the inside of the container and the anode with a liquid fuel wicking material, and the cathode is exposed to the outside air through the diffusion layer, so that auxiliary equipment such as a fuel feed pump and a cathode gas fan are operated. Power not needed was obtained.

Further, by filling the inside of the fuel container with a low-density fuel wicking material, the fluctuation of the liquid fuel during operation was able to be reduced. In particular, by installing ventilation holes with gas-liquid separation functions arranged on multiple surfaces of the fuel container, normal power generation is possible regardless of the posture of the fuel cell, achieving the essential characteristics as a portable power generator. We were able to.
[Example 3]
In this embodiment, a fuel cell using a metal fuel container coated with an epoxy resin as a platform will be described.

  The MEA and the cathode-side diffusion layer were produced in the same manner as in Example 2. As shown in FIG. 17, the fuel container 1 was a SUS304 fuel container having an outer shape of 22 mm width × 79 mm length × 23 mm height and a thickness of 0.3 mm. The container is composed of a frame and upper and lower lids each having a 16 mm width × 16 mm length × 0.5 mm depth and having four fuel cell mounting portions 2 formed by pressing.

  In the center of the fuel cell mounting portion 2, a slit having a width of 0.5 mm and a length of 10 mm is provided as a diffusion hole 3 by punching at a portion of a width of 10 mm and a length of 10 mm. At the corners of the upper and lower lids, SUS304 vent holes 1 having an inner diameter of 1 mm without using a gas-liquid separation membrane were provided. Using these members, a glass fiber mat having a porosity of about 80% was filled therein as a fuel wicking material 5 and then welded and sealed to obtain a fuel container 1.

  The outer surface of the fuel container 1 was coated with a liquid epoxy resin paint (Flep: manufactured by Toray Thiokol Co., Ltd.) to a thickness of 0.1 mm and thermally cured to form an insulating layer 20. The surface of the fuel cell mounting portion 2 was electrolessly plated with nickel as the anode-side interconnector 4 in the same shape as in Example 2.

  The fuel cell fixing plate is made of hard vinyl chloride of 22 mm width × 79 mm length × 1 mm thickness in the same manner as in the second embodiment, and is orthogonal to the slit of the fuel cell mounting portion 2 on the surface in contact with the cathode of each fuel cell. A slit having a width of 1 mm and a length of 10 mm was provided in the direction in which the holes were formed, and ventilation holes 15 were provided at the four corners. Using this slit, a cathode collector plate 7 made of nickel and having a thickness of 0.2 mm and connected to the adjacent interconnector 4 on the anode side of the fuel cell was attached.

  As in Example 2, the present fuel cell is formed by stacking a fluorine-based rubber anode-side gasket, MEA, a fluorine-based rubber cathode-side gasket, a cathode-side diffusion layer, and a fuel cell fixing plate in this order. It was fastened to the fuel container with a 100 μm thick slitted heat-shrinkable resin tube. An anode terminal and a cathode terminal mounted on the upper and lower sides of the fuel container were connected in series to form output terminals.

The outer shape of the obtained fuel cell power generation system is about 22mm wide × 79 mm long × 27 mm height, power generation area is composed of 8 series fuel cell 1 cm ^2. The volume of the fuel container was approximately 38 ml. The fuel container was filled with a 10% aqueous methanol solution as a fuel through a vent hole of the fuel container with a syringe, and the fuel cell was operated at an operating temperature of 50 ° C.

  Further, when a fuel container was filled with about 37 ml of a 10% aqueous methanol solution and power was continuously generated at a load current of 100 mA, a stable voltage was obtained at an output of 2.6 V for about 4 hours. At this time, the output density of the fuel cell power generator was about 5.5 W / l, and the volume energy density per fuel liter was about 22 Wh / l. Even when this fuel cell was operated in the upside down or overturned position, no change in output voltage was observed, no liquid fuel leaked, and no increase in the pressure inside the fuel container was observed.

  As described above, a plurality of fuel cells are mounted on one outer wall surface of the liquid fuel container and connected in series by an interconnector, and the series cells mounted on the plurality of surfaces are arranged in parallel to be stacked via a separator. It is possible to realize a 2.6V-class small fuel cell without the need. At this time, the anode side is brought into contact with the inside of the container and the anode with a liquid fuel wicking material, and the cathode is exposed to the outside air through the diffusion layer, so that auxiliary equipment such as a fuel feed pump and a cathode gas fan are required. And no power supply became possible.

This embodiment is characterized in that the fuel container is made of a metal material and the surface thereof is insulated so that the volume can be increased. In addition, by filling the inside of the fuel container with a relatively high-density fuel wicking material, it is possible to prevent leakage of liquid fuel only by providing a small opening hole without a gas-liquid separation function, Very stable power generation was possible. Further, in the production of the power generation device, each fuel cell can be easily fixed using the heat-shrinkable resin tube.
[Example 4]
A description will be given of a prismatic methanol fuel cell power generator using a metal fuel container coated with an epoxy resin as a platform.

  The MEA was manufactured in the same manner as in Example 2 so that the outer shape of the electrode was 20 mm wide × 25 mm long and the outer shape was 24 mm wide × 29 mm long. Further, the cathode diffusion layer was formed in a shape of 20 mm width × 25 mm length in the same manner as in Example 2.

  The outer shape of the fuel container is a hexagonal cylinder with a uniform width of 28 mm, a height of 190 mm, and a wall thickness of 0.3 mm. Each side is pressed with a fuel cell mounting part of 24 mm width × 29 mm length × 0.5 mm depth. It is processed and consists of a hexagonal upper and lower lid.

  A slit having a width of 0.5 mm and a length of 25 mm was punched at an interval of 0.5 mm in a central portion of the fuel cell mounting portion having a width of 20 mm and a length of 25 mm. The upper and lower lids were provided with six ventilation holes with an inner diameter of 2 mm each having a gas-liquid separation function similar to that shown in FIG. Six glass fiber mats having a thickness of 5 mm and a porosity of about 85% were attached to the inner wall of each cylinder, and the upper and lower lids were sealed by welding. Further, the outer surface of the fuel container was coated with a liquid epoxy resin paint (Flep: manufactured by Toray Thiokol Co., Ltd.) to a thickness of 0.1 mm, and then heat-cured, and nickel was used as the anode-side interconnector in the same shape as in Example 2. Electroless plating was performed.

  The fuel cell fixing plate 8 serving as a fuel cell holding plate is made of hard vinyl chloride of 28 mm width × 190 mm length × 1 mm thickness in the same manner as in Example 2, and the fuel container is cut into a surface in contact with the cathode of each fuel cell. Slits having a width of 0.5 mm and a length of 20 mm were provided at 0.5 mm intervals in a direction orthogonal to the slits of the portion. A nickel cathode current collector plate with a slit of 0.2 mm in thickness was attached in order to connect the adjacent interconnector on the anode side of the fuel cell using this slit.

  As in Example 2, the fuel cell of the present invention is formed by stacking a fluorine-based rubber anode gasket, MEA, a fluorine-based rubber cathode gasket, a cathode diffusion layer, and a fuel cell fixing plate in this order. The outer peripheral portion was fixed to the fuel container by tightening with a 100 μm-thick heat-shrinkable resin tube having a slit. FIG. 18 shows the obtained fuel cell power generator.

36 unit cells 13 were mounted on the outer wall of a hexagonal prism fuel container 1 having six ventilation holes 15 at the top and bottom, respectively, were connected in series, and the output terminal 16 was taken out of the fuel container 1. The external shape of the obtained fuel cell power generation device is a 36-series DC power generation device having a hexagonal column of approximately 28 mm in height, a height of approximately 190 mm, and a power generation area of 5 cm ² . The internal volume of the fuel container was approximately 300 ml.

  When about 300 ml of a 10% aqueous methanol solution was charged into the fuel container and continuous power generation was performed at a load current of 500 mA, a stable voltage was obtained at an output of 12.1 V for about 4 hours. At this time, the power density was about 15 W / l, and the volume energy density per fuel liter was 60 Wh / l. Even when the fuel cell was operated in the upside down or overturned position, no change in output voltage was observed, no leakage of liquid fuel was observed, and no increase in pressure in the fuel container was observed.

  As described above, a plurality of fuel cells are mounted on one outer wall surface of the liquid fuel container and connected in series by an interconnector, and the series cell groups mounted on the plurality of surfaces are arranged in parallel, so that the cells are not stacked via a separator. A 12V-class small fuel cell can be realized. At this time, the anode side is brought into contact with the inside of the container and the anode with a liquid fuel wicking material, and the cathode is exposed to the outside air through the diffusion layer, so that auxiliary equipment such as a fuel feed pump and a cathode gas fan are required. And no power supply became possible.

This embodiment is characterized in that the power generation area is relatively large and the output is increased, and stable power generation is possible regardless of the posture during operation. Further, in the production of the power generator, it has become possible to easily fix each fuel cell using the heat-shrinkable resin tube.
[Example 5]
A power generation device using a square, high-output methanol aqueous solution as a fuel will be described. The anode layer is composed of a catalyst powder in which platinum / ruthenium alloy particles of platinum / ruthenium 1/1 (atomic ratio) are dispersed and supported by 50 wt% on a carbon support, a 30 wt% perfluorocarbonsulfonic acid (Nafion 117) electrolyte as a binder, and water as a binder. A slurry comprising a mixed solvent of alcohol / alcohol (a mixed solvent of water: isopropanol: normal propanol at a weight ratio of 20:40:40) was formed into a porous film having a thickness of about 20 μm by a screen printing method.

  The cathode layer is formed by mixing a catalyst powder in which 50 wt% of platinum fine particles are supported on a carbon support and a slurry in which a polytetrafluoroethylene aqueous dispersion is used as a binder so as to have a dry weight of 25 wt% by a roll method to a thickness of about 25 μm. Was formed on the porous membrane. The cathode layer was fired at 290 ° C. for 1 hour in air to decompose the surfactant in the aqueous dispersion. The above-mentioned anode porous membrane and cathode porous membrane were cut into a size of 16 mm width × 56 mm length, respectively, to obtain an anode and a cathode.

  Next, a Nafion 117 electrolyte membrane having a thickness of 50 μm was cut into a 120 mm width × 180 mm length, and about 0.5 ml of a 5% by weight Nafion 117 alcohol aqueous solution (manufactured by Fluka Chemika) was infiltrated into the surface of the anode layer. Then, it is dried at 80 ° C. for 3 hours under a load of about 1 kg. Next, a 10% by weight aqueous solution of Nafion 117 alcohol (manufactured by Fluka Chemika) was infiltrated into the surface of the cathode layer so as to be 25% by weight in terms of the weight of the dried cathode, and then joined to the center of the electrolyte membrane first. The MEA was fabricated by joining the anode layer so as to overlap with it, applying a load of about 1 kg, and drying at 80 ° C. for 3 hours.

  The fuel container is a rigid vinyl chloride container having an outer shape of 28 mm width × 128 mm length × 24 mm height and a wall thickness of 2 mm, which is laminated with an adhesive. Eighteen cuts of 16 mm width × 56 mm length × 0.1 mm depth for mounting the fuel cell were provided on the outer wall of the hexahedral container in the same manner as in Example 2.

  Slits having a width of 0.5 mm and a length of 16 mm were provided at intervals of 0.5 mm in a portion having a width of 16 mm and a length of 56 mm at the center of the fuel cell mounting portion. At the four corners of the two surfaces having the maximum area of the fuel container, eight vents having an inner diameter of 2 mm and having the same gas-liquid separation function as in FIG. 4A were provided.

  In the notch for mounting the fuel cell, a 50 μm thick metallizing layer of a nickel electroless plated film was used as an anode interconnector for electrically connecting in series with an adjacent fuel cell in the same manner as in Example 2. Was formed. The fuel cell fixing plate is also sized according to each outer wall surface of the fuel container in the same manner as in Example 2, and a slit of 0.5 mm width × 56 mm length orthogonal to the slit provided in the fuel container is provided at a portion in contact with the cathode. They were provided at 0.5 mm intervals.

  Further, a cathode current collector with a slit was attached to the fuel cell fixing plate. From the 18 fuel cells mounted on the outer wall of the fuel container, output terminals connected in series were taken out by the cathode current collector adjacent to the anode-side interconnector.

The members thus obtained were laminated in the order of the anode-side gasket and the MEA, and the outer periphery of each fuel cell and the outer periphery of the fuel container of the fuel cell fixing plate were joined with an adhesive. As shown in FIG. 19, the obtained fuel cell power generation device has an outer shape of approximately 28 mm width × 128 mm length × 28 mm height, and 18 serial cells 13 having a power generation area of approximately 9 cm ² mounted on the wall surface of the fuel container 1. This is a DC power generator having an output terminal 16 and eight air holes 5 provided on the upper and lower surfaces with a gas-liquid separation function.

  The internal volume of the fuel container was approximately 59 ml. When about 55 ml of a 10% aqueous methanol solution was filled in the fuel container and power was continuously generated at a load current of 1 A, a stable voltage was obtained at an output of 6.1 V for about 45 minutes. In this fuel cell, no change in the output voltage was observed even when the fuel cell was operated in the upside down or overturned posture, there was no leakage of liquid fuel, and no increase in the pressure in the fuel container was observed.

  As described above, a plurality of fuel cells are mounted on one outer wall surface of the liquid fuel container, connected in series by an interconnector, and a series of battery cells mounted on a plurality of surfaces are arranged in parallel to be stacked via a separator. A small fuel cell of 6V class can be realized without performing the above. At this time, the anode side is brought into contact with the inside of the container and the anode with a liquid fuel wicking material, and the cathode is exposed to the outside air through the diffusion layer, so that auxiliary equipment such as a fuel feed pump and a cathode gas fan are required. And no power supply became possible.

  In this embodiment, by dispersing polytetrafluoroethylene in the cathode catalyst layer to impart water repellency and to facilitate diffusion of generated water, even if the diffusion layer is omitted, the performance of the components can be reduced. A structure with a reduced number of points can be obtained.

FIG. 2 is a sectional structural view of the fuel container of the present invention. FIG. 2 is a schematic diagram illustrating a configuration of an electrode / electrolyte membrane assembly of the present invention. It is sectional drawing of the fuel cell fixing plate of this invention. It is sectional drawing of the ventilation hole sectional structure of this invention, and a storage container mounting sectional structure. FIG. 2 is a configuration diagram of a mounting part of the fuel cell according to the first embodiment. FIG. 1 is an external view of a fuel cell power generation device according to a first embodiment. FIG. 2 is a configuration diagram of an appearance and a cross section of a separator of Comparative Example 1. It is a block diagram which shows the lamination structure of the battery of a comparative example. The present invention is also a configuration diagram of an outer plate of a high-voltage square-tube unit battery. FIG. 9 is a diagram showing a power supply appearance structure and a power supply / fuel tank combination in Comparative Example 1. 1 is a configuration diagram of an electrode / electrolyte membrane assembly of Example 1. FIG. FIG. 1 is an external view of a fuel cell power generation device according to a first embodiment. FIG. 2 is a sectional view of the fuel cell power generation device according to the first embodiment. FIG. 9 is an external view of a fuel cell power generation device of Comparative Example 2. FIG. 9 is a cross-sectional view of a fuel storage container according to a second embodiment. FIG. 9 is a configuration diagram of a mounting part of the fuel cell according to the second embodiment. FIG. 13 is a sectional view of a fuel container according to a third embodiment. FIG. 14 is an external view of a fuel cell power generation device according to a fourth embodiment. FIG. 14 is an external view of a fuel cell power generation device according to a fifth embodiment.

Explanation of reference numerals

  DESCRIPTION OF SYMBOLS 1 ... Fuel container, 2 ... Fuel cell mounting part, 3 ... Diffusion hole, 4 ... Interconnector, 5 ... Liquid fuel suction material, 6 ... Fuel cell terminal, 7 ... Cathode current collector plate, 8 ... Fuel cell fixing plate, 9: MEA (electrolyte membrane / electrode assembly), 10: gasket, 11: diffusion layer, 12: methanol aqueous solution, 13: single cell, 15: vent hole, 16: output terminal, 17: fastening band, 18: fuel retention Layer 19: Vent mounting hole 20: Insulating layer 21: Electrolyte membrane 22: Anode layer 23: Cathode layer 50: Gas-liquid separation membrane 51: Vent pipe 52: Vent lid 54: Rib 81, separator; 82, manifold; 83, separator longitudinal sectional view, 84, separator transverse sectional view, 85, power generation opening, 86, manifold opening, 87, manifold embedding part, 88, groove embedding part, 89 ... Rib portion, 92 Liner, 93 ... wicking material, 94 ... laminated cell, 102 ... fuel tank, 103 ... fuel cell mounting part, 105 ... cell holder.

Claims (13)

An anode for oxidizing fuel and a cathode for reducing oxygen are formed through an electrolyte membrane, and in a fuel cell power generator using liquid as fuel,
A fuel cell is provided with one or more ventilation holes on the wall thereof, and a plurality of cells having an electrolyte membrane, an anode and a cathode are mounted on the wall of the fuel container, and the respective cells are electrically connected. Fuel cell power generator. An anode for oxidizing fuel and a cathode for reducing oxygen are formed through an electrolyte membrane, and in a fuel cell power generator using liquid as fuel,
A liquid fuel holding material is filled in contact with the inner wall surface of the fuel container, the wall surface of the fuel container is provided with one or more air holes having gas-liquid separation capability, and the outer wall surface of the fuel container has an electrolyte membrane, an anode, and a cathode. A plurality of unit cells each having the above structure are mounted, and each unit cell is electrically connected.   3. The fuel cell power generator according to claim 1, wherein a diffusion layer is disposed in contact with the anode and / or the cathode electrode.   The fuel cell power generator according to claim 1, 2 or 3, wherein the liquid fuel holding material filled in the fuel container is in contact with the anodes or the anode-side diffusion layers of the plurality of cells mounted on the outer wall surface of the fuel container. .   4. The fuel cell power generator according to claim 1, wherein the liquid fuel container is made of a material having electrical insulation. An anode for oxidizing fuel and a cathode for reducing oxygen are formed through an electrolyte membrane, and in a fuel cell power generator using liquid as fuel,
An anode having a plurality of ventilation holes having gas-liquid separation capability on at least one opposed wall surface of a fuel container, a liquid fuel holding material filled in an inner wall surface of the fuel container, and an electrolyte membrane and a diffusion layer on an outer wall surface of the fuel container And a plurality of unit cells each having a cathode and a cathode, wherein the diffusion layer is in contact with a liquid fuel holding material, and the unit cells are electrically connected.   The fuel cell power generator according to claim 6, wherein at least one of the plurality of ventilation holes has a function of a fuel supply hole. 7. The fuel according to claim 6, wherein an anode for oxidizing the fuel and a cathode for reducing the oxygen are formed via an electrolyte membrane, and at least an outer wall surface of a fuel container in which a fuel cell using a liquid as a fuel is mounted is electrically insulated. Battery generator.   The fuel cell power generator according to any one of claims 1 to 6, wherein the fuel is an aqueous methanol solution. An anode for oxidizing fuel and a cathode for reducing oxygen are formed through an electrolyte membrane, and in a fuel cell power generator using liquid as fuel,
At least one opposed wall surface of the fuel container has a plurality of ventilation holes each having gas-liquid separation capability, and the inner wall surface of the fuel container is filled with a liquid fuel holding material, and the electrically insulated outer wall surface of the fuel container is provided. A plurality of cells each having an electrolyte membrane, an anode, and a cathode having a diffusion layer, and a plurality of cells constituted by a diffusion layer in contact with a liquid fuel holding material are electrically connected in series, in parallel, or in a combination of series and parallel A fuel cell power generator characterized by being joined by:   An anode for oxidizing methanol and a cathode for reducing oxygen are formed via an electrolyte membrane, and at least one opposed wall surface of a fuel container of a fuel cell using a liquid as a fuel has a plurality of vent holes each having a gas-liquid separation ability. A plurality of cells each composed of an electrolyte membrane, an anode, and a cathode having a diffusion layer are mounted on the electrically insulated outer wall surface of the fuel container, wherein the inner wall surface of the fuel container is filled with a liquid fuel holding material, A battery charger using a fuel cell power generator in which a diffusion layer is in contact with a liquid fuel holding material and each cell is electrically connected in series, parallel, or a combination of series and parallel.   An anode for oxidizing methanol and a cathode for reducing oxygen are formed via an electrolyte membrane, and at least one opposed wall surface of a fuel container of a fuel cell using liquid as a fuel has a plurality of vent holes having gas-liquid separation capability. A fuel cell inner wall surface is filled with a liquid fuel holding material, and a plurality of unit cells each comprising an electrolyte membrane, an anode and a cathode having a diffusion layer are mounted on an electrically insulated outer wall surface of the fuel container, A portable power source using a fuel cell power generator in which a diffusion layer is in contact with a liquid fuel holding material and each cell is electrically connected in series, in parallel, or in a combination of series and parallel. An anode for oxidizing methanol and a cathode for reducing oxygen are formed via an electrolyte membrane, and at least one opposed wall surface of a fuel container of a fuel cell using liquid as a fuel has a plurality of vent holes having gas-liquid separation capability. The inner wall surface of the fuel container is filled with a liquid fuel holding material, and a plurality of unit cells each comprising an electrolyte membrane, an anode and a cathode having a diffusion layer are mounted on the electrically insulated outer wall surface of the fuel container, A portable electronic device, wherein a diffusion layer is in contact with a liquid fuel holding material, and each unit cell is driven by a fuel cell power generation device that is electrically connected in series, parallel, or a combination of series and parallel.

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