JP2006049086A - Fuel cell module - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell module, without impairing portability and which is user-friendly with respect to an environment. <P>SOLUTION: The fuel cell module is configured to be mountable to a housing portion provided to portable equipment, and comprises one or more fuel cells S1, S2, a circuit board 14 for supporting the fuel cells S1, S2, and a hydrogen-generating cell 30 supported by the circuit board 14 and supplying fuel to the fuel cells S1, S2. The hydrogen-generating cell 30 comprises a first housing chamber, configured to house an iron tablet therein and to generate heat by reaction of the iron with air, a second housing chamber configured to house water therein and to generate water vapor by the generated heat, and a third housing chamber configured to house an iron tablet therein, to introduce water vapor from the second housing chamber and to generate hydrogen by the reaction of the water vapor with the iron. A pipe 31 is provided to supply hydrogen to the fuel cells S1, S2. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a fuel cell module configured to be attachable to a portable device as a power source for the portable device.

  Polymer fuel cells using solid polymer electrolytes such as polymer electrolytes have high energy efficiency, are thin, small and light, and are therefore being actively developed for household generation systems and automobiles. The conventional structure of such a fuel cell is disclosed in the following Non-Patent Document 1, which is shown in FIG.

  As shown in FIG. 12, an anode 101 and a cathode 102 are disposed with a solid polymer electrolyte membrane 100 interposed therebetween. Further, the unit cell 105 is configured by being sandwiched by a pair of separators 104 via a gasket 103. A large number of the unit cells 105 are stacked, and the unit cells 105 are electrically connected in series to constitute the fuel cell N. The electrode 106 can be taken out from the stacked unit cells 105 at both ends. Such a fuel cell N is attracting attention as a power source for electric vehicles and a distributed power source for home use in various applications because of its clean and high efficiency.

  On the other hand, with the development of IT in recent years, lithium ion secondary batteries are used for most power sources of mobile devices (portable devices) such as mobile phones, notebook computers, and digital cameras. However, power consumption tends to increase as these mobile devices become more sophisticated, and attention has been focused on clean and highly efficient fuel cells for the power supply.

  In the laminated structure as shown in FIG. 12, there is room for improvement in terms of reduction in thickness and weight required as a power source for portable devices. Further, as a structure using a fuel cell as a power source of a mobile phone, there is a fuel cell mounted device disclosed in Patent Document 1 below. This device is attached to a lower end portion of a mobile phone via a hinge portion, and is configured to be able to switch between a state where the opening portion of the device is opened and a state where it is shielded by rotating the hinge portion.

  However, the structure having a movable part such as a hinge part has a problem that the mechanism is complicated. Moreover, when using a mobile phone, it is necessary to rotate the hinge portion to open the opening of the device, which causes a problem that the size increases during use. Moreover, when using a fuel cell as a power supply, not only a fuel cell but other accompanying parts and devices are required. Therefore, when a fuel cell is used as a power source for portable equipment, it is necessary to adopt a configuration that does not impair portability in consideration of these points.

  Further, when a fuel cell is mounted on a portable device, there is a problem of how to configure a fuel supply device for supplying hydrogen to the fuel cell. That is, a micropump for supplying hydrogen to the fuel battery cell and a heating mechanism for bringing the chemical reaction to generate hydrogen are required. However, if these mechanisms are incorporated in a normal form, the fuel cell module mounted on the portable device must be enlarged.

  On the other hand, a fuel reformer (corresponding to a fuel supply device) that generates a hydrogen-rich gas from hydrocarbons and steam is disclosed in Patent Document 2 below. This device is provided with two reactors, an upstream reactor and a downstream reactor, and receives the raw fuel gas containing air from the fuel supply device by the upstream reactor and internally performs the steam reforming reaction. Then, the oxidation reaction proceeds, and the generated hydrogen-rich fuel gas is discharged from the downstream reactor to the fuel supply path. However, since this fuel reformer requires a mechanism for feeding hydrocarbons and air, it is difficult to make the fuel reformer so large as to be incorporated in a portable device.

In addition, although hydrocarbon is used as a raw material and a hydrogen-rich gas can be generated, a gas such as carbon dioxide gas may be generated instead of pure hydrogen. Therefore, there is room for improvement in terms of environmental impact.
Nikkei Mechanical separate volume "Fuel Cell Development Frontline" Date of issue: June 29, 2001, Publisher: Nikkei BP, Chapter 3, PEFC, 3.1 Principles and Features p46 JP 2004-55307 A JP 11-92102 A (paragraph 0086, FIG. 3 etc.)

  The present invention has been made in view of the above circumstances, and its problem is that when a fuel cell is used as a power source in a portable device, the portability of the portable device is not impaired and the influence on the environment is taken into consideration. Is to provide modules.

In order to solve the above problems, a fuel cell module according to the present invention includes:
As a power source for portable equipment, a fuel cell module configured to be attachable to a housing provided in the portable equipment,
At least one fuel cell;
A support for supporting the fuel cell,
A fuel supply device that is supported by the support and supplies fuel to the fuel cells,
This fuel supply device
A first storage chamber configured to generate iron by containing iron and reacting with the air;
A second storage chamber configured to store water and generate water vapor by the heat generation;
A third storage chamber configured to generate hydrogen when the iron is stored and water vapor from the second storage chamber is introduced and reacts with the iron;
An introduction pipe for supplying the hydrogen to the fuel cell is provided.

  The operation and effect of the fuel cell module having this configuration will be described. The fuel cell module having this configuration can be attached to a housing provided in a portable device. For example, a polymer battery used in a mobile phone, an AA battery or an AAA battery used in a PDA. The module can be mounted by the same operation as that for mounting the etc. The fuel cell is supported by a support, and a fuel supply device is also supported by the support.

  The fuel supply device includes a first storage chamber, a second storage chamber, and a third storage chamber. Iron is stored in the first storage chamber, which reacts with air to generate heat. Air can be easily taken in by providing an opening or a lid in the first storage chamber. And water is accommodated in a 2nd storage chamber, and water can be steamed using the reaction heat in a 1st storage chamber. Furthermore, iron is accommodated also in the 3rd storage chamber, and iron and water vapor | steam are made to react by sending water vapor | steam here. By this reaction, pure hydrogen gas is generated and can be sent to the fuel cell through the introduction pipe.

  Thus, a mechanism for feeding fuel gas for generating hydrogen gas is unnecessary, and a pipe for feeding air for reacting iron and oxygen is also unnecessary. In addition, since the water is stored in the second storage chamber, a mechanism such as a pipe or a pump for feeding water is unnecessary. Further, pure hydrogen is produced, and no carbon dioxide, carbon monoxide, or the like is generated, so that it does not adversely affect the environment. As a result, when a fuel cell is used as a power source for a portable device, it is possible to provide a fuel cell module that does not impair the portability of the portable device and considers the influence on the environment.

  In the present invention, it is preferable that a first restriction mechanism for restricting an amount of air introduced into the first storage chamber is provided.

  The ambient temperature for generating hydrogen requires a certain high temperature range, but it is a problem if it rises too much. Therefore, it is preferable to provide a mechanism for limiting the amount of air introduced into the first storage chamber. For example, a configuration in which an opening is provided in the first storage chamber and a shutter that opens and closes the opening is conceivable.

  In the present invention, it is preferable to provide a second restriction mechanism for restricting the amount of water vapor introduced into the third storage chamber.

  Also, if the amount of water vapor generated is too large, the amount of hydrogen gas generated will increase too much, so the gas pressure will be too high, the water consumption will be more than necessary, and the time for water replacement will be earlier. There's a problem. Therefore, it is preferable to provide a mechanism for limiting the amount of water vapor introduced into the third storage chamber. For example, a configuration in which an opening is provided in the first storage chamber and a shutter that opens and closes the opening is conceivable.

  The second storage chamber according to the present invention stores the water soaked in the water holding body, and allows water vapor to pass through the boundary position between the second storage chamber and the third storage chamber and does not allow iron to pass through. Means are preferably provided.

  Rather than storing water as it is in the second storage chamber, it is preferable to soak water in a water holding body (such as cotton). Thereby, handling of water can be performed easily. Further, by providing the filter at the boundary position between the second storage chamber and the third storage chamber, it is possible to ensure that only water vapor passes.

  In the present invention, it is preferable that the first storage chamber, the second storage chamber, and the third storage chamber are each formed in a cylindrical room, and are arranged in series.

  By adopting such a configuration, the fuel supply device can be compacted as a whole, and a configuration suitable for being housed in a portable device can be obtained.

  In this invention, it is preferable that iron is accommodated in a 1st storage chamber and a 3rd storage chamber in the form of a tablet. By using a tablet, handling can be facilitated.

  A fuel cell according to the present invention includes a plate-shaped solid polymer electrolyte, a pair of electrode plates disposed on both sides of the solid polymer electrolyte, and a pair of metal plates disposed further outside the electrode plate. It is preferable that the periphery of these metal plates is sealed with caulking with an insulating layer interposed therebetween.

  By configuring a fuel cell based on a plate-shaped solid polymer electrolyte, the thickness of the cell can be reduced. As a result, the module can also be reduced in thickness and made into a compact shape. Further, by sealing the peripheral edges of the pair of metal plates with caulking through the insulating layer, it is possible to reliably perform the sealing for each cell without increasing the thickness while preventing a short circuit between them. Further, since the cell is not required to be rigid as compared with the conventional structure shown in FIG. 12, each fuel cell can be significantly reduced in thickness. Furthermore, since a solid polymer electrolyte and a metal plate are used, a free planar shape and bending are possible, and a small, lightweight and free shape design is possible.

  In the present invention, of the pair of metal plates, the cathode side metal plate is preferably provided with an air intake opening.

  According to this configuration, since air can be naturally supplied from the opening of the cathode side metal plate, an electrode reaction can be caused in each electrode plate by supplying fuel from the inlet of the anode side metal plate. An electric current can be taken out from the metal plate in contact with the electrode plate.

  In the present invention, there is provided a metal pressing member for fixing the fuel cell to the support, and the pressing member also has a function of connecting the electrode of the fuel cell to an electronic circuit mounted on the support. Preferably it is.

  According to this configuration, the fuel cell can be fixed to the circuit board by the pressing member. Moreover, since the pressing member is made of metal, electrical connection between the electrode of the fuel cell and the electronic circuit can be performed by the pressing member. Thereby, the structure of a module can be simplified and size reduction can be achieved.

  The electronic circuit according to the present invention preferably includes a booster circuit for boosting the output voltage of the fuel cell to a voltage suitable for the portable device.

  The value of the voltage that can be taken out by one fuel battery cell is as low as 0.5 V, for example, and the voltage value required for the electronic circuit inside the portable device is as high as 5 V, for example. Therefore, by incorporating a booster circuit, a desired voltage can be taken out using a small number of fuel cells.

  A preferred embodiment of a fuel cell module according to the present invention will be described with reference to the drawings. FIG. 1 shows a state in which a fuel cell module (hereinafter simply referred to as “module”) according to the present invention is mounted on a PDA (personal portable information device: equivalent to a portable device). FIG. 2 is a plan view showing the main configuration of the module. FIG. 3 is a cross-sectional view schematically showing the configuration of the module.

  FIG. 1 shows the back side of the PDA 11 and shows a state where the lid of the battery housing portion 12 is removed and the module 13 is mounted. The module 13 is detachable with respect to the housing portion 12, and can be inserted and removed with the same feeling as that of a normal battery (such as an AA battery).

  As shown in FIG. 2, two fuel cells S <b> 1 and S <b> 2 are mounted on the surface of the circuit board 14. Although the detailed configuration of the fuel cells S1 and S2 will be described later, a large number of opening holes are formed on the surface side so that air can be taken in. Although not shown in FIG. 2, a gas inlet and a gas outlet for taking in hydrogen gas as fuel are provided on the back surface side of the first fuel cell S1, and hydrogen gas is provided at the gas inlet. Is connected to a pipe 31 (see also FIG. 4). The second fuel cell S2 is also provided with a gas inlet and connected to the gas outlet of the first fuel cell S1 by a pipe 16 (see FIG. 3). Thus, the hydrogen gas supplied from the pipe 31 is also supplied to the second fuel cell S2 via the pipe 16. In addition, since all of the supplied hydrogen gas is consumed as fuel, the second fuel battery cell S2 is not provided with a gas discharge port. The pipes 31 and 16 are preferably made of metal (aluminum, brass, etc.), but are not limited thereto. You may form with the material which has flexibility.

  Each fuel cell S1, S2 is provided with a pressing member 18 for fixing to the circuit board 14 (corresponding to a support). The holding member 18 has a holding portion 18 a having a frame shape and a claw portion 18 b for fixing to the circuit board 14. The peripheral edge portion 17 (four sides of the rectangular cell) of the fuel cells S1 and S2 is pressed by the pressing portion 18a, and the claw portion 18b of the pressing member 18 is soldered by using the hole 14b formed in the circuit board 14. To fix. Thereby, fuel cell S1, S2 can be fixed with respect to the circuit board 14. FIG.

  As shown in FIG. 3, the fuel cells S <b> 1 and S <b> 2 are arranged side by side in a plane, and are fixed to the circuit board 14 by a pressing member 18. The pressing member 18 is made of a metal such as phosphor bronze (or may be another metal), and can be formed by pressing a phosphor bronze plate. The surface (upper side in FIG. 3) of the fuel cells S1 and S2 is formed of a metal plate as described later and functions as an electrode (positive electrode or negative electrode). Therefore, the electrodes of the fuel cells S1 and S2 can be connected to the wiring pattern of the circuit board 14 by using the metal pressing member 18. In addition, the back surfaces (lower side in FIG. 3) of the fuel cells S1 and S2 are the other electrodes (negative electrode or positive electrode), and are pressed against the electrode pattern formed on the surface of the circuit board 14 to electrically Connection can be made. The pressing to the electrode pattern can be performed by the pressing member 18. A pipe 16 for connecting the hydrogen gas flow paths is also provided.

  A booster circuit (corresponding to an electronic circuit) is provided on the back surface of the circuit board 14. The output voltage that can be taken out by one fuel cell is about 0.5V. If two of these are provided and connected in series as shown in the figure, an output voltage of about 1V is obtained. On the other hand, an output voltage of about 5V is required to supply power to the circuits inside the portable device. Therefore, by providing a booster circuit (DC-DC converter) as described above, the voltage can be boosted to an appropriate voltage and supplied to the PDA body. However, a known circuit configuration can be used for the booster circuit. The position and shape of the terminal portion for supplying power to the PDA are not shown in the figure, but are not limited to a specific form and can be appropriately configured. Also, an electronic circuit other than the booster circuit can be mounted. This point will be described later.

  A hydrogen generation cell 30 (corresponding to a fuel supply device) is disposed on the back side of the circuit board 14. As shown in FIG. 4, the hydrogen generation cell 30 is formed of a cylindrical container, and contains pure iron tablets and moisture therein. Pure water is generated by heating the internal water to generate water vapor and reacting it with pure iron. The hydrogen generation cell 30 is connected to the gas inlet of the first fuel cell S1 by a pipe 31. Thereby, the hydrogen gas which is the fuel generated by the hydrogen generation cell 30 can be supplied to the fuel cells S1 and S2.

The chemical reaction for generating hydrogen is as shown in the following formula.
[Chemical 1]
4H ₂ O + 3Fe → Fe ₃ O ₄ + 4H ₂
That is, when water (steam) is supplied to pure iron, they react to produce iron oxide and hydrogen gas. This chemical reaction does not generate gases that adversely affect the environment, such as carbon dioxide and carbon monoxide. In other words, it can be said that it is clean energy. Only hydrogen gas (pure hydrogen) is supplied to the fuel cells S1, S2.

  The chemical reaction in the hydrogen generation cell 30 is performed at about 100 ° C to 400 ° C. A heating system for bringing the hydrogen generation cell 30 into the above temperature range is provided in the hydrogen generation cell 30 itself.

  The back surface of the circuit board 14 is covered with a resin mold 22 (package). Thereby, the back surface side of the circuit board 14 can be sealed. The surface side of the circuit board 14 is left open without being covered with a package so that the fuel cells S1 and S2 can freely take in air. The package may be removably attached to the circuit board 14.

  The fuel cell module according to the present invention is preferably configured to be recyclable. Therefore, it is preferable to configure the package so that the hydrogen generation cell 30 can be freely removed. For example, an opening is formed at an appropriate location of the package, and the hydrogen generation cell 30 is configured to be detachable.

<Configuration of hydrogen generation cell>
Next, the configuration of the hydrogen generation cell according to the first embodiment will be described with reference to FIGS. The hydrogen generation cell 30 includes a main body 32 having a cylindrical shape. The main body 32 is preferably formed of an appropriate metal, but a material other than metal may be used. Inside the main body 32, a first storage chamber R1, a second storage chamber R2, and a third storage chamber R3 are arranged in series in this order.

  In the first storage chamber R1, tablets 35 made of pure iron are stored. The first storage chamber R <b> 1 communicates with the opening of the main body 32 and is sealed with a lid 34. If an opening (not shown) is formed in the lid 34, air can be taken in. By reacting the air with the tablet 35, an oxidation reaction occurs and heat is generated. The heating temperature is set to about 100 ° C., and facilitates the hydrogen generation reaction described later. If the main body 32 is made of metal, the generated heat can be easily transmitted.

  The second storage chamber R2 is a space for storing water, and stores the absorbent cotton 37 (corresponding to a water holding body) soaked in water. The second storage chamber R2 and the first storage chamber R1 are completely blocked by a partition wall. The water is heated by an exothermic reaction in the first storage chamber R1, and becomes water vapor. This steam is introduced into the third storage chamber R3. In addition, you may use things other than absorbent cotton as a water holding body.

  Pure iron tablets 36 are accommodated in the third accommodating chamber R3, as in the first accommodating chamber R1. Pure hydrogen is produced by the reaction between the iron tablet 36 and water vapor. A metal net 38 (corresponding to a partitioning means) is provided at a boundary position between the second storage chamber R2 and the third storage chamber R3, and supports the tablet 36 and allows water vapor to pass through the eyes of the net. The generated pure hydrogen is sent out through a pipe 31 (corresponding to an introduction pipe) and supplied to the first fuel cell S1. Since it is pure iron that reacts with water vapor, no gas other than hydrogen is produced, and only hydrogen is supplied purely to the fuel cell S1. An appropriate filter member other than a metal net can be used as the partition means for allowing only water vapor to pass. The third storage chamber R <b> 3 communicates with the opening of the main body portion 32 and is sealed with a lid 33. The pipe 31 is attached to the lid 33.

  When supplying hydrogen to the fuel cell S1, it is not necessary to use a mechanical element such as a pump, and the hydrogen is naturally supplied to the fuel cell S1 by the pressure of the generated hydrogen gas. Since no pump is required, the entire module can be made smaller and thinner.

  As for specific dimensions of the hydrogen generation cell 30, for example, the outer diameter of the main body portion 32 can be set to φ45 mm and the height can be set to about 40 mm. The weight of the tablet accommodated in the first storage chamber R1 is about 10 g, the weight of the tablet stored in the third storage chamber R3 is about 15 g, and the amount of water stored in the second storage chamber R2 is about 5 cc. Can do. As a result, 20 cc of hydrogen is generated per minute, and the PDA can be driven for about 6 hours.

<Another Embodiment of Hydrogen Generation Cell>
Next, another embodiment of the hydrogen generation cell will be described with reference to FIG. 5 has a cylindrical main body, the hydrogen generating cell 30 may be configured by a square main body as shown in FIG. 6A, and as shown in FIG. You may form in a rectangular parallelepiped thin flat plate shape. Of course, it is good also as a rectangular parallelepiped which is not flat form. A thin flat plate is considered preferable because the module accommodated in the PDA can be thinned.

<Other configuration examples of module>
Next, another configuration example of the module will be described with reference to the block diagram of FIG. In this configuration example, the hydrogen generation cell 30 is controlled. As shown in FIG. 7, the voltage generated by the fuel cells S <b> 1 and S <b> 2 is extracted by the voltage extraction unit 40, and is boosted by the booster circuit 41 so as to be a voltage suitable for the device. Then, an appropriate voltage is supplied to the PDA via the power supply terminal 42.

  On the other hand, in order to control the hydrogen generation cell 30 that supplies hydrogen gas as fuel to the fuel cells S1, S2, a temperature sensor 43, a first opening / closing mechanism 47 (corresponding to a first limiting mechanism), A second opening / closing mechanism 46 (corresponding to a second limiting mechanism) is provided. The temperature sensor 43 is provided to detect whether or not the reaction temperature for generating hydrogen gas is too high. For example, if the temperature is too high, control is performed in a direction to suppress this.

  The temperature sensor 43 is driven by a sensor drive circuit 44. The first and second opening / closing mechanisms 46 and 47 are controlled by the opening / closing mechanism control unit 45. The first opening / closing mechanism 47 is a mechanism for providing an opening in the lid 34 of the first storage chamber S1, and further opening / closing the opening. That is, the amount of air taken in from the opening can be adjusted by the first opening / closing mechanism 47. Therefore, when the heating temperature becomes too high, the amount of air taken in can be suppressed and the reaction between pure iron and air can be suppressed. Thereby, it can control so that heating temperature does not rise.

  The second opening / closing mechanism 46 is a mechanism that blocks the boundary between the second storage chamber R2 and the third storage chamber R3 in order to suppress the amount of water vapor fed from the second storage chamber S2 to the third storage chamber S3. . When the heating temperature becomes too high, the supply of water vapor is blocked to suppress the amount of hydrogen generated.

  The opening / closing mechanisms 46 and 47 can be constituted by, for example, a shutter mechanism that goes in and out of an opening or a boundary position. An actuator such as a solenoid can be used to drive the shutter. When the temperature sensor 43 detects that the temperature has risen excessively, the opening / closing mechanisms 46 and 47 are driven to control the reaction. As energy for driving the temperature sensor 43 and the opening / closing mechanisms 46 and 47, energy generated by the fuel cells S1 and S2 itself can be used.

<Configuration of fuel cell>
Next, a preferred embodiment of a fuel cell (unit cell) used in the fuel cell module according to the present invention will be described with reference to the drawings. FIG. 8 is an assembled perspective view showing an example of the unit cell of the fuel cell of the present invention, and FIG. 9 is a longitudinal sectional view showing an example of the unit cell of the fuel cell of the present invention.

  As shown in FIGS. 8 to 9, the fuel cell of the present invention includes a plate-shaped solid polymer electrolyte 1, a cathode side electrode 2 disposed on one side of the solid polymer electrolyte 1, and a second side. The anode side electrode plate 3 is provided. In the present embodiment, a fuel flow channel 9 is formed in the anode side metal plate 5 by etching, and the peripheral portions of the anode side metal plate 5 and the cathode side metal plate 4 are made thinner than other portions by etching. Here is an example.

  The solid polymer electrolyte 1 may be any solid polymer membrane battery as long as it is used in conventional solid polymer membrane batteries. From the viewpoint of chemical stability and conductivity, a perfluorocarbon having a sulfonic acid group which is a super strong acid. A cation exchange membrane made of a polymer is preferably used. Nafion (registered trademark) is preferably used as such a cation exchange membrane.

  In addition, for example, a porous film made of a fluororesin such as polytetrafluoroethylene impregnated with the above Nafion or other ion conductive material, a porous film made of a polyolefin resin such as polyethylene or polypropylene, or a non-woven fabric. A material carrying Nafion or another ion conductive material may be used.

  The thinner the solid polymer electrolyte 1 is, the more effective it is to make the whole thinner. However, in consideration of ion conduction function, strength, handling property, etc., 10 to 300 μm can be used, but 25 to 50 μm is preferable. .

  The electrode plates 2 and 3 can function as a gas diffusion layer, and can supply and discharge fuel gas, oxidizing gas, and water vapor, and at the same time can exhibit a current collecting function. As the electrode plates 2 and 3, the same or different ones can be used, and it is preferable to support a catalyst having an electrode catalytic action on the base material. The catalyst is preferably supported at least on the inner surfaces 2 b and 3 b in contact with the solid polymer electrolyte 1.

  As the electrode base material, for example, conductive carbon materials such as carbon paper, fibrous carbon such as carbon fiber nonwoven fabric, and aggregates of conductive polymer fibers can be used. In general, the electrode plates 2 and 3 are prepared by adding a water-repellent substance such as a fluororesin to such a conductive porous material. When the catalyst is supported, a catalyst such as platinum fine particles and fluorine It is formed by mixing a water-repellent substance such as a resin, mixing it with a solvent to form a paste or ink, and then applying this to one side of an electrode substrate that should face the solid polymer electrolyte membrane. The

  In general, the electrode plates 2 and 3 and the solid polymer electrolyte 1 are designed according to the reducing gas and the oxidizing gas supplied to the fuel cell. In the present invention, it is preferable to use air as the oxidizing gas and hydrogen gas as the reducing gas. In addition, methanol, dimethyl ether, or the like can be used instead of the reducing gas.

  For example, when hydrogen gas and air are used, the cathode side electrode 2 on the side where the air is naturally supplied causes a reaction between oxygen and hydrogen ions, so that water is generated. Is preferred. In particular, under the operating conditions of low operating temperature, high current density, and high gas utilization rate, the electrode porous body is likely to be clogged (flooded) due to the condensation of water vapor, particularly at the air electrode where water is generated. Therefore, in order to obtain stable characteristics of the fuel cell over a long period of time, it is effective to ensure the water repellency of the electrode so that the flooding phenomenon does not occur.

  As the catalyst, at least one metal selected from platinum, palladium, ruthenium, rhodium, silver, nickel, iron, copper, cobalt and molybdenum, or an oxide thereof can be used. A supported one can also be used.

  The thickness of the electrode plates 2 and 3 is more effective for reducing the overall thickness as the thickness is reduced, but is preferably 50 to 500 μm in view of electrode reaction, strength, handling properties, and the like.

  The electrode plates 2 and 3 and the solid polymer electrolyte 1 may be laminated and integrated in advance by adhesion, fusion, or the like, or may simply be arranged in a stacked manner. Such a laminated body can also be obtained as a thin film electrode assembly (MEA), and may be used.

  A cathode side metal plate 4 is disposed on the surface of the cathode side electrode plate 2, and an anode side metal plate 5 is disposed on the surface of the anode side electrode plate 3. The anode side metal plate 5 is provided with a fuel inlet 5c and a discharge port 5d, and further, in the present embodiment, a flow channel 9 is provided in the anode side metal plate 5.

  The cathode-side metal plate 4 is provided with a number of openings 4c for supplying oxygen in the air. As long as the cathode side electrode plate 2 can be exposed, the number, shape, size, formation position, and the like of the opening 4c may be any. However, in consideration of the supply efficiency of oxygen in the air and the current collection effect from the cathode side electrode plate 2, the area of the opening 4c is preferably 10 to 50% of the area of the cathode side electrode plate 2, In particular, 20 to 40% is preferable.

  The opening 4c of the cathode side metal plate 4 may be provided with a plurality of circular holes, slits, or the like regularly or randomly, or may be provided with a metal mesh.

  As the metal plates 4 and 5, any metal can be used as long as it does not adversely affect the electrode reaction, and examples thereof include stainless steel plates, nickel, copper, and copper alloys. However, from the viewpoint of elongation, weight, elastic modulus, strength, corrosion resistance, press workability, etching workability and the like, a stainless steel plate, nickel and the like are preferable.

  The channel groove 9 provided in the anode side metal plate 5 may have any planar shape or cross-sectional shape as long as a channel for hydrogen gas or the like can be formed by contact with the electrode plate 3. However, in consideration of the channel density, the lamination density at the time of lamination, the flexibility, etc., it is preferable to mainly form the vertical groove 9a parallel to one side of the metal plate 5 and the vertical groove 9b. In this embodiment, a plurality of (three in the illustrated example) vertical grooves 9a are connected in series to the horizontal grooves 9b to balance the flow path density and the flow path length.

  A part of the channel groove 9 (for example, the lateral groove 9 b) of the metal plate 5 may be formed on the outer surface of the electrode plate 3. As a method of forming the flow channel groove on the outer surface of the electrode plate 3, a mechanical method such as a hot press or cutting may be used. However, it is preferable to perform groove processing by laser irradiation in order to suitably perform fine processing. From the viewpoint of performing laser irradiation, the base material for the electrode plates 2 and 3 is preferably an aggregate of fibrous carbon.

  One or a plurality of inlets 5c and outlets 5d communicating with the channel groove 9 of the metal plate 5 can be formed. In addition, although the thickness of the metal plates 4 and 5 is more effective for reducing the overall thickness as the thickness is reduced, 0.1 to 1 mm is preferable in consideration of strength, elongation, weight, elastic modulus, handling property, and the like.

  Etching is preferable as a method of forming the flow channel 9 in the metal plate 5 in view of processing accuracy and ease. In the channel groove 9 by etching, a width of 0.1 to 10 mm and a depth of 0.05 to 1 mm are preferable. The cross-sectional shape of the channel groove 9 is preferably substantially square, substantially trapezoidal, substantially semicircular, V-shaped or the like.

  Etching is also preferably used for forming the opening 4 c in the metal plate 4, thinning the peripheral portions of the metal plates 4, 5, and forming the inlet 5 c to the metal plate 5.

  Etching can be performed using, for example, a dry film resist or the like, after forming an etching resist having a predetermined shape on the metal surface, and then using an etching solution corresponding to the type of the metal plates 4 and 5. Moreover, the cross-sectional shape of the flow-path groove | channel 9 can be controlled more precisely by performing a selective etching for every metal using the laminated board of 2 or more types of metals.

  The embodiment shown in FIG. 9 is an example in which the caulking portions (peripheral portions) of the metal plates 4 and 5 are thinned by etching. In this way, the caulking portion is etched to have an appropriate thickness, whereby sealing by caulking can be performed more easily. From this viewpoint, the thickness of the crimped portion is preferably 0.05 to 0.3 mm.

  In the present invention, the peripheral edges of the metal plates 4 and 5 are sealed by caulking in an electrically insulated state. Electrical insulation can be performed by interposing the insulating material 6, the peripheral edge of the solid polymer electrolyte 1, or both.

  In the present invention, when caulking is performed, as shown in FIG. 9, a structure in which the solid polymer electrolyte 1 is sandwiched between the peripheral edges of the metal plates 4 and 5 is preferable, and the solid polymer electrolyte 1 is sandwiched with the insulating material 6 interposed. More preferable is the structure. According to such a structure, inflow of gas or the like from one of the electrode plates 2 and 3 to the other can be effectively prevented. The thickness of the insulating material 6 is preferably 0.1 mm or less from the viewpoint of thinning. In addition, it is possible to further reduce the thickness by coating the insulating material (for example, the insulating material 6 can have a thickness of 1 μm).

  As the insulating material 6, a sheet-like resin, rubber, thermoplastic elastomer, ceramics, and the like can be used. However, in order to improve the sealing performance, resin, rubber, thermoplastic elastomer, and the like are preferable, and in particular, polypropylene, polyethylene, polyester, fluorine Resin and polyimide are preferable. The insulating material 6 can be integrated with the metal plates 4 and 5 in advance by sticking or coating the peripheral edges of the metal plates 4 and 5 directly or via an adhesive.

  As the caulking structure, the structure shown in FIG. 9 is preferable from the viewpoint of sealing performance, ease of manufacture, thickness, and the like. That is, the outer edge portion 5a of one metal plate 5 is made larger than the other outer edge portion 4a, and the insulating material 6 is interposed, while the outer edge portion 5 of one metal plate 5 is changed to the outer edge portion 4a of the other metal plate 4. A caulking structure that is folded back so as to sandwich pressure is preferable. In this caulking structure, it is preferable to provide a step in the outer edge portion 4a of the metal plate 4 by pressing or the like. Such a caulking structure itself is known as metal processing, and can be formed by a known caulking device.

  In the present invention, one or a plurality of unit cells as shown in FIG. 9 can be used, but the unit cell is composed of the solid polymer electrolyte 1, the pair of electrode plates 2, 3, and the pair of metal plates 4, 5. It is also possible to stack a plurality of unit cells or arrange them on the same surface. (It is preferable to arrange them on the same plane as shown in FIGS. 1 to 3 because the module can be made compact.) By doing so, the fastening parts of the bolts and nuts are mutually connected, and the cell parts are fixed. A high-power fuel cell can be provided without applying pressure.

  In use, it is possible to directly connect a fuel supply pipe to the fuel inlet 5c and the outlet 5d of the metal plate 5, but the thickness of the fuel cell is reduced in order to reduce the thickness of the fuel cell. It is preferable to provide a joint mechanism having a pipe parallel to the surface of the metal plate 5. In FIG. 9, a metal pin 5 e for joint is attached to the metal plate 5 at the inlet 5 c. This attachment can be performed by caulking or press fitting. The pipe 15 can be press-fitted and attached to the pin 5e.

  Since the fuel cell of the present invention can be thinned and can be designed in a small, lightweight and free shape, it can be suitably used particularly for mobile devices (portable devices) such as PDAs, mobile phones, and notebook PCs.

<Another embodiment>
In the embodiment shown in FIGS. 1 to 3, two unit cells (fuel battery cells) are provided, but the number of unit cells may be one, or three or more. It can be determined as appropriate in consideration of the size of the accommodating portion provided in the portable device, the required battery capacity, and the like. The size of the unit cell can also be determined as appropriate.

  In the above-described embodiment, an example in which the caulking structure illustrated in FIG. 9 is employed has been described. However, in the present invention, a caulking structure as illustrated in FIGS. 10A to 10B may be employed.

  The caulking structure shown in FIG. 10A is a caulking structure in which the outer edge portions 4a and 5a of both the metal plates 4 and 5 are folded back. In this unit cell, a sealing member S is interposed between each of the metal plates 4 and 5 and the solid polymer electrolyte 1 so that the gas diffused from each of the electrode plates 2 and 3 is not mixed. .

  Furthermore, the caulking structure shown in FIG. 10B is an insulating material that insulates each of the metal plates 4 and 5 by another metal plate 7 without folding the outer edge portions 4a and 5a of both the metal plates 4 and 5. It is the crimping structure clamped via 6a, 6b. In the caulking structure, both the metal plates 4 and 5 can be used as they are without being pressed.

  8 to 10, the caulking is performed through the insulating material 6 (corresponding to the insulating layer). However, the caulking may be performed by extending the periphery of the solid polymer electrolyte 1 and interposing it. In this case, the solid polymer electrolyte 1 functions as an insulating layer. In this case, since it is not necessary to provide an insulating material, the configuration can be simplified.

  In the above-described embodiment, an example in which the flow channel groove is formed in the anode side metal plate by etching has been shown. However, in the present invention, the flow channel groove is formed in the anode side metal plate by a mechanical method such as press working or cutting. It may be formed.

  FIG. 11 shows an example in which the channel groove 9 is formed by deformation of the metal plate 5 by press working. When the flow channel 9 is formed by pressing, the flow channel 9 preferably has a width of 0.1 to 10 mm and a depth of 0.1 to 10 mm. The cross-sectional shape of the channel groove 9 is preferably substantially square, substantially trapezoidal, substantially semicircular, V-shaped or the like.

  The size and number of openings formed in the fuel cells S1, S2 can be set as appropriate. In this embodiment, iron is stored in the form of a tablet, but may be stored in a form other than this (for example, powder).

The figure which shows the state where the fuel cell module is installed in PDA Plan view showing the main part of the fuel cell module Sectional view schematically showing the configuration of the module Diagram showing the appearance of a hydrogen generation cell Sectional view showing the structure of a hydrogen generation cell External view showing another embodiment of the hydrogen generation cell Block diagram showing another embodiment of the module Assembly perspective view showing an example of a unit cell of the fuel cell of the present invention The longitudinal cross-sectional view which shows an example of the unit cell of the fuel cell of this invention Sectional drawing of the principal part which shows the other example of the crimping structure of the fuel cell of this invention The longitudinal cross-sectional view which shows the other example of the unit cell of the fuel cell of this invention A perspective view showing the configuration of a conventional fuel cell

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Solid polymer electrolyte 2 Cathode side electrode plate 3 Anode side electrode plate 4 Cathode side metal plate 4c Opening part 5 Anode side metal plate 5c Inlet 5d Outlet 6 Insulation material 9 Channel groove 11 PDA
12 Housing part 13 Fuel cell module 14 Circuit board 17 Peripheral part 18 Holding member 21 Pipe 22 Mold S1, S2 Fuel cell (unit cell)

Claims (10)

As a power source for portable equipment, a fuel cell module configured to be attachable to a housing provided in the portable equipment,
At least one fuel cell;
A support for supporting the fuel cell,
A fuel supply device that is supported by the support and supplies fuel to the fuel cells,
This fuel supply device
A first storage chamber configured to generate iron by containing iron and reacting with the air;
A second storage chamber configured to store water and generate water vapor by the heat generation;
A third storage chamber configured to generate hydrogen when the iron is stored and water vapor from the second storage chamber is introduced and reacts with the iron;
A fuel cell module comprising an introduction pipe for supplying the hydrogen to the fuel cell.   2. The fuel cell module according to claim 1, further comprising a first restriction mechanism that restricts an amount of air introduced into the first storage chamber.   3. The fuel cell module according to claim 1, further comprising a second restriction mechanism that restricts an amount of water vapor introduced into the third storage chamber.   The second storage chamber is provided with partition means for storing water soaked in the water holding body and allowing water vapor to pass therethrough and iron not to pass through at a boundary position between the second storage chamber and the third storage chamber. The fuel cell module according to any one of claims 1 to 3, wherein the fuel cell module is provided.   The said 1st storage chamber, the 2nd storage chamber, and the 3rd storage chamber are formed in a column-shaped room, respectively, and these are arrange | positioned in series, The any one of Claims 1-4 characterized by the above-mentioned. The fuel cell module described.   The fuel cell module according to any one of claims 1 to 5, wherein the iron is stored in the first storage chamber and the third storage chamber in the form of a tablet.   The fuel cell includes a plate-shaped solid polymer electrolyte, a pair of electrode plates disposed on both sides of the solid polymer electrolyte, and a pair of metal plates disposed further outside the electrode plate. The fuel cell module according to any one of claims 1 to 6, wherein the periphery of the metal plate is sealed by caulking with an insulating layer interposed therebetween.   8. The fuel cell module according to claim 7, wherein an air intake opening is provided in the cathode side metal plate of the pair of metal plates.   A metal pressing member for fixing the fuel cell to the support is provided, and the pressing member also has a function of connecting the electrode of the fuel cell to an electronic circuit mounted on the support. The fuel cell module according to any one of claims 1 to 8.   10. The fuel cell module according to claim 9, wherein the electronic circuit includes a booster circuit for boosting an output voltage of the fuel battery cell to a voltage suitable for a portable device.

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