JP2007123163A - Fuel cell and power supply system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of taking out large power output in spite of a compact size. <P>SOLUTION: The fuel cell is equipped with at least one unit cell U having an opening hole 4c for taking in air and installed for generating electric power and a hydrogen gas generation unit 40 for generating hydrogen gas to be supplied to the unit cell U, and a fan 22 for compulsorily sending air to the opening hole 4c is installed. The blast by the fan 22 also conducts cooling of the hydrogen gas generation unit 40. A driving circuit 51 driving the fan 22 by electric power generated with at least one unit cell U is provided. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a fuel cell comprising at least one unit cell provided for power generation, in which an opening hole for taking in air is formed, and a fuel gas generator for generating fuel gas to be supplied to the unit cell, and The present invention relates to a power supply system provided with this.

  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, the power consumption tends to increase as the performance of these mobile devices increases, and attention has been focused on clean and highly efficient fuel cells for power supply or charging.

  In particular, when a fuel cell is used in a portable device such as a notebook computer or a mobile phone, a structure that can maintain portability or downsizing is desired. Also, when a fuel cell is mounted on a device, it is required to be easily mounted.

  As a unit cell (fuel cell) that constitutes a fuel cell, a device that has been reduced in size suitable for a portable device or the like is known from the following Patent Document 1 by the present applicant. The unit cell includes a plate-shaped solid polymer electrolyte, a cathode side electrode plate and an anode side electrode plate arranged on both sides thereof, and a cathode side metal plate and an anode side metal plate arranged further outside these electrode plates. And form a thin unit cell. And many opening holes for taking in air are formed in the cathode side metal plate. Further, a fuel gas such as hydrogen gas is supplied to the anode side.

JP 2005-268176 A

  As described above, air is supplied to the cathode side in the form of natural air supply through the opening hole. Although the magnitude of the electric output from the fuel cell depends on the amount of air taken in, there is a limit to the magnitude of the electric output that can be taken out due to natural supply.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide a fuel cell and a power supply system capable of taking out a large electric output while realizing downsizing.

In order to solve the above problems, a fuel cell according to the present invention provides:
An opening for taking in air is formed, and at least one unit cell provided for power generation;
A fuel cell comprising a fuel gas generator for generating fuel gas to be supplied to the unit cell,
It is provided with a blowing means for forcibly sending air toward the opening hole.

  The operation and effect of the fuel cell having this configuration will be described. The fuel cell includes at least one unit cell provided for power generation. The fuel gas generator generates fuel gas, and an electrical output is obtained by the fuel gas (anode side) supplied to the unit cell and the air (cathode side) supplied from the opening hole. The blowing means is configured to forcibly send air toward the opening hole. Therefore, since a unit cell can take in more air than natural air supply, a large output can be obtained compared to natural air supply. As a result, it is possible to provide a fuel cell capable of taking out a large electrical output while realizing miniaturization.

  In this invention, it is preferable that the ventilation by the said ventilation means performs the cooling effect | action with respect to the said fuel gas generation part. When the fuel gas is generated in the fuel gas generator, the ambient temperature becomes high, and this influence may cause a decrease in electric output. Therefore, by cooling the fuel gas generation section by blowing air, it is possible to suppress the atmospheric temperature from becoming too high and to extract a large electric output.

  In this invention, it is preferable to provide the drive circuit which drives the said ventilation means with the electric power generated by the said at least 1 unit cell.

  By configuring the air blowing means to be driven by the generated power of the unit cell itself, it is not necessary to provide a dedicated drive power source, and the increase in size of the fuel cell can be suppressed.

  In the present invention, it is preferable that a ventilation passage is formed between the surface of the unit cell where the opening hole is formed and the outer surface of the fuel gas generation unit.

  A ventilation passage is formed between the surface on which the opening hole is formed and the outer shape surface of the fuel gas generator, and air is supplied to the opening hole by blowing air to the passage, and fuel is supplied through the outer surface. The gas generating part can be cooled. Therefore, two objectives can be achieved at the same time with one air passage, and the structure of the air passage can be simplified.

  In this invention, it is preferable to provide the opening window for taking in air inside the vicinity of the said ventilation means.

  Thereby, air can be taken in efficiently, and air blowing by the air blowing means can be performed continuously and smoothly.

  In order to solve the above-described problems, a power supply system according to the present invention includes the fuel cell according to the present invention and a device that receives power supply from the fuel cell.

  Examples of the device include a notebook computer, a PDA, and a mobile phone, but are not limited to a specific device. The fuel cell may be directly attached to and detached from the power terminal of the device, or may be connected via a connection cord.

  A preferred embodiment of a fuel cell according to the present invention will be described with reference to the drawings.

<First Embodiment>
First, a preferred embodiment of the fuel cell according to the first embodiment will be described with reference to the drawings. FIG. 1 is a perspective view showing the external shape of a fuel cell. The fuel cell F has a stick-like appearance as a whole. The fuel cell F includes a main body 20 and a power supply terminal 21 provided on one end side in the axial direction y of the main body 20. Although the USB terminal is illustrated as the power supply terminal 21, other types of terminals may be used.

  The main body 20 has a substantially rectangular parallelepiped shape, and is composed of one or a plurality of case members. The main body portion 20 includes four wall surface portions 20a, and functions necessary for the fuel cell F are mounted in an internal space formed by the wall surface portions 20a. A first end surface portion 20b is formed on one end side of the main body portion 20 in the axial direction, and the power supply terminal 21 is provided in a shape protruding outward. A second end face 20c (not visible in FIG. 1) is formed on the other axial end of the main body 20, and an opening / closing part for detachably removing a hydrogen gas generation unit (corresponding to a fuel gas generation part) is provided. It is composed.

  Each wall surface portion 20a is formed with an opening window 20d, and air can be taken in through the opening window 20d. As will be described in detail later, a fan is provided inside to force air into the cathode side of the unit cell.

  FIG. 2 is a view showing a state in which the case member is removed from the fuel cell F shown in FIG. FIG. 3 is an exploded perspective view showing the internal configuration. Four substantially rectangular support substrates 30 are provided along the four wall surfaces 20a, and one unit cell U (fuel cell) is mounted on each support substrate 30 one by one. In the present embodiment, a total of four unit cells U are provided, and the cell power generation unit is configured by connecting them in series. By joining the four support substrates 30 as shown in the figure, a cylindrical frame having a square cross section is formed. A square circuit board 31 is attached to one end side in the axial direction (y) of the cylindrical frame, and the above-described power supply terminal 21 is coupled to the circuit board 31. The circuit board 31 is mounted with chip parts or the like constituting a booster circuit or a stabilization circuit, and can supply a desired stable power to the device.

  The circuit board 31 is configured to be detachable from the support board 30 formed in the cylindrical frame. A male connection connector 32 is provided on one end side of the support substrate 30 in the axial direction, and this is connected to a female connection connector 33 provided on the circuit board 31 side. When the voltage is boosted by the circuit board 31, the voltage to be boosted is different depending on the device used. Therefore, by preparing a plurality of types of circuit boards 31 corresponding to the number of devices used, the support substrate 30 is prepared. Can be used in common, and can correspond to a wide variety of products at low cost. In the place where the connection connector 32 is disposed, a cutout 30a is formed in the support substrate 30, and the position of the cutout 30a corresponds to the position of the opening window 20d for air intake.

  Adjacent support substrates 30 are coupled by an L-shaped plate 34 (corresponding to a connecting member). A hole 30b is formed on the other end side of the support substrate 30 in the axial direction, and the support substrate 30 and the L-shaped plate 34 are connected by a screw 34a. Thereby, the four support substrates 30 can be firmly connected to each other and desired strength can be maintained. The L-shaped plate 34 is made of metal, and not only mechanically couples the support substrates 30 but also has a function of electrically connecting electrode patterns formed on the support substrates 30. Therefore, wiring connection for connecting the patterns between the support substrates 30 becomes unnecessary, space can be used effectively, and assemblability is improved.

  Further, since the height (thickness) of the L-shaped plate 34 can be accommodated at the same level as the unit cell U mounted on the support substrate 30, a special space for arranging the L-shaped plate 34 is not necessary. This is unnecessary and can contribute to the miniaturization of the fuel cell F.

  The support substrate 30 is a rectangular substrate on which the unit cell U is mounted. A connector 35 for attaching the unit cell U to the support substrate 30 is provided. The connector 35 is provided for each unit cell U, although only one location is shown in FIG. The connector 35 is formed with a rectangular opening 35a. By providing the opening 35a, the unit cell U can take air into the inside.

<Unit cell (fuel cell)>
First, a preferred embodiment of a unit cell U mounted on a fuel cell F according to the present invention will be described with reference to the drawings. 4 is an assembled perspective view showing an example of the unit cell, and FIG. 5 is a longitudinal sectional view of the unit cell shown in FIG.

  As shown in FIGS. 4 to 5, the fuel cell of the present invention includes a plate-shaped solid polymer electrolyte 1, a cathode-side electrode plate 2 disposed on one side of the solid polymer electrolyte 1, and the other side. And an anode-side electrode plate 3 disposed on the substrate. Further, a cathode side metal plate 4 and an anode side metal plate 5 are provided on the outer side of the electrode plates 2 and 3. 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. .

  Electrode plates 2 and 3 (gas diffusion plates) that function as gas diffusion layers are used to supply and discharge fuel gas, oxidant gas, and water vapor, and at the same time collect electricity it can. 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 large number of opening holes 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 holes 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 hole 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 9b) 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 heating press or cutting may be used. However, it is preferable to perform groove processing by laser irradiation in order to perform fine processing suitably. 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 hole 4 c in the metal plate 4, thinning the peripheral portion 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. 5 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 (corresponding to press bending) 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, as shown in FIG. 5, 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. 5 is preferable from the viewpoint of sealing performance, ease of manufacture, thickness, and the like. That is, the peripheral region 5a of one metal plate 5 is made larger than the peripheral region 4a of the other, and the peripheral region 5a of one metal plate 5 is replaced with the peripheral region 4a of the other metal plate 4 while the insulating material 6 is interposed. 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 peripheral region 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 FIG. 5, 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 metal pipe 10 can be press-fitted and attached to the pin 5e. A gas supply flow path can be formed by further inserting a resin pipe 11 into the metal pipe 10 (see also an exploded perspective view of FIG. 5B). The same configuration can be adopted for the outlet 5d.

  Further, as shown in FIG. 5, the metal plates 4 and 5 are formed with protrusions 4f and 5f. In the space formed inside the protrusions 4f and 5f, the electrode plates 2 and 3 are provided. Be contained. The protrusions 4f and 5f can be formed by drawing (punching) the metal plates 4 and 5.

  Returning to FIG. 3, the support substrate 30 is formed with a notch 30 c for placing the resin pipe 11 shown in FIG. 5. Thereby, as shown in FIG. 2, the pipe 11 for connecting a gas flow path can be arrange | positioned.

  A blower fan 22 (corresponding to a blower) is disposed on one axial end side of the cylindrical frame formed by the support substrate 30. The blower fan 22 is arranged so as to be adjacent to the circuit board 31 and is fixed to the support board 30 by screws 36. A general-purpose fan can be used as the blower fan 22, and a motor 22a is provided at the center and a blower blade 22b is provided at the periphery. By providing the blower fan 22, air can be forcibly sent toward the opening hole 4 c of the unit cell U, whereby a larger electrical output can be taken out. In addition, air is taken into the fuel cell F through the opening window 20d.

  The connector 35 for coupling the unit cell U to the support substrate 30 will be described in more detail. The connector 35 includes a frame-shaped pressing portion 35b, and a rectangular opening window 35a is formed at the center thereof. A large number of opening holes 4 c formed in the cathode side metal plate 4 are exposed by the opening window 35 a. The frame-shaped pressing portion 35 b has a function of pressing the metal plate 4 in the direction of the substrate surface of the support substrate 30 and presses the outer peripheral region of the metal plate 4. The frame-shaped pressing portion 35b presses the periphery of the protruding portion 4f (see FIG. 5) of the metal plate 4. As a result, an appropriate pressing force acts between the metal plates 4 and 5, the electrode plates 2 and 3, and the solid polymer electrolyte 1 so that the contact between these members is kept good. Thereby, frictional resistance can be reduced and an electrical output can be taken out efficiently.

  A pair of leg portions 35 c are integrally formed on both sides of the frame-shaped pressing portion 35 b and are connected to the cathode electrode pattern formed on the support substrate 30. In addition, the connector 35 is configured to be coupled to the support substrate 30 by screws 37 at the four corners of the frame-shaped pressing portion 35b. In other words, female screws 35 d are formed at the four corners of the connector 35, and the screws 37 are configured to be screwed into the female screws 35 d, thereby coupling the connector 35 to the support substrate 30. Accordingly, the unit cells U are coupled to the support substrate 30 by the connector 35 so as to be mechanically and electrically connected.

  The height of the leg portion 35c of the connector 35 can be determined in consideration of the height dimension of the unit cell U to be connected. That is, the unit cell U is set to be pressed against the support substrate 30 with an appropriate pressing force. Moreover, the strength as the connector 35 can be secured by providing the leg portion 33c.

  The connector 35 can be manufactured by bending a metal plate such as brass, and is subjected to a plating process to reduce contact resistance as necessary. The thickness of the connector 35 is about 0.5 mm so that the entire thickness including the unit cell U does not increase. The thickness dimension can be set according to the size of the unit cell U.

  Although not shown, the support substrate 30 is formed with a cathode electrode pattern (+) and an anode electrode pattern (−). The leg part 35c of the connector 35 contacts the cathode electrode pattern (+). Thereby, the cathode side metal plate 4 and the cathode electrode pattern are electrically connected. Since the connector 35 is coupled by the screw 37, it is possible to ensure electrical contact with the pattern. The connection between the connector 35 and the support substrate 30 is not limited to the above, and may be performed by bolts / nuts or soldering.

  The four unit cells U mounted on the four support substrates 30 are connected in series, and the electrode patterns of the adjacent support substrates 30 are electrically connected by the L-shaped plate 34 as described above. . By connecting in series, the output voltage can be increased. The four unit cells U are arranged such that the cathode side opening 4c faces the internal space formed by the cylindrical frame. Since the opening 4c is exposed in the direction of the internal space, the air can be easily taken into the cathode.

  Next, the configuration of the gas flow path will be described with reference to FIG. In FIG. 6 (a), the gas flow path is divided into two groups consisting of two unit cells U connected in series, and the hydrogen gas generated from the hydrogen gas generation unit 40 branches in the middle, and each group Is supplied with hydrogen gas. In the configuration example shown in FIG. 6B, the gas flow paths of the four unit cells U are connected in series. As described above, the gas flow path can be configured by series connection, parallel connection, or an appropriate combination of series connection and parallel connection.

<Configuration example of hydrogen gas generation unit>
Next, a configuration example of the hydrogen gas generation unit 40 (fuel gas generation unit, hereinafter abbreviated as “unit”) will be described. The unit 40 is detachably disposed in a space formed inside a cylindrical frame constituted by the four support substrates 30. Therefore, the external shape of the unit 40 is also formed in a rectangular parallelepiped shape. FIG. 7 is a diagram conceptually showing the configuration of the unit 40.

  In FIG. 7A, the unit 40 includes a water storage portion 41 and a metal storage portion 42, and a metal powder such as aluminum is stored in the metal storage portion 42. Hydrogen gas can be generated by reacting the water in the water accommodating part 41 with the metal powder. A communication hole 42 a is formed at the bottom of the metal accommodating part 42, and water is supplied into the metal accommodating part 42 through the communication hole 42 a. In addition, a water supply paper 43 such as filter paper is disposed at the bottom of the metal storage unit 42 to supply water into the metal storage unit 42 in a stable state. The communication holes 42a and the water supply paper 43 are configured to supply water by capillary action so that a large amount of water is not rapidly supplied. Water supply paper may also be filled into the communication hole 42a.

  Further, a pressing plate 41a is provided in the water accommodating portion 41, and the spring 47 presses the water in the direction in which it enters through the communication hole 42a. A pipe connection terminal 44a is provided on one end side of the unit main body 44 constituting the appearance of the water storage portion 41, and the resin pipe 11 is inserted therein. When the unit 40 is taken out from the main body 20 of the fuel cell F, this part is cut off.

  FIG. 7B shows another embodiment of the unit 40, in which a water accommodating portion 41 is disposed at the lower portion and a metal accommodating portion 42 is disposed at the upper portion, and a space 46 for evaporating water is provided therebetween. A water supply paper 43 is inserted into the water accommodating portion 41, and the water that has risen through the water supply paper 43 is heated in the space 46 to become water vapor. The water vapor passes through the mesh 45 and reacts with the metal accommodated in the metal accommodating portion 42 to generate hydrogen gas. As the metal, pure iron can be used, and it can be accommodated in the form of powder or tablet. As a heating means for heating water, an appropriate method such as using a film heater can be adopted.

  Various methods for generating hydrogen gas are known, and the method to be employed in the present invention can be appropriately selected.

  FIG. 8 is a diagram showing a state when the hydrogen gas generation unit 40 is attached and detached. As shown in FIG. 8, the second end surface portion 20c of the main body portion 20 can be opened and closed by a hinge 20e. That is, the second end surface portion 20c functions as an opening / closing door. Further, an engagement claw 20f is formed and engages with an engagement recess (not shown) formed inside the main body portion 20. The engagement can be released by elastically deforming the engagement claw 20f by an appropriate method. Various open / close mechanisms for attaching and detaching the unit 40 are conceivable and are not limited to the illustrated ones.

  Moreover, you may comprise so that the 2nd end surface part 20c may be eliminated and the end surface part 40a of the hydrogen gas generation unit 40 may be exposed to an external appearance. In this case, an engagement mechanism is provided in the hydrogen gas generation unit 40 itself. Moreover, it is preferable that a guide mechanism for smoothly attaching and detaching the hydrogen gas generation unit 40 is provided inside.

  Although FIG. 7 and FIG. 8 demonstrated the structure which attaches / detaches the whole fuel gas generation part, the structure which attaches / detaches only the metal accommodating part 42 may be employ | adopted. In the example of FIG. 7A, only the metal accommodating portion 42 that accommodates aluminum is configured to be detachable, and when the aluminum is consumed, the metal accommodating portion 42 is removed to accommodate new aluminum. When water is consumed, a supply port for supplying water is provided, and new water is supplied from this supply port. The above points can be made the same in the case of FIG.

  FIG. 9 is a cross-sectional view of the fuel cell F taken along a plane perpendicular to the axial direction. As can be seen from this figure, a space indicated by a dimension δ is formed on the entire circumference of the unit 40 between the outer surface 40b of the unit 40 and the unit cell U (connector 35). This dimension δ is set to about 1 mm and functions as a ventilation passage. That is, when the fan 22 is driven, air is supplied to the opening 4c of the unit cell U through the air passage. Further, since the air flows through the periphery of the unit 40, it acts in the direction of cooling the heat generated by the reaction that generates hydrogen gas. Thereby, it can suppress that the atmospheric temperature inside fuel cell F rises, and can improve electric power generation efficiency. About the magnitude | size of the channel | path for ventilation, it can set suitably. In addition, a guide mechanism (not shown) for inserting and removing the unit 40 is provided so that a ventilation passage can be formed.

<Circuit configuration>
Next, the configuration of a circuit mounted on the fuel cell F will be described with reference to FIG. Electric power is supplied via the power supply terminal 21 by the cell power generation unit 50 configured by the unit cells U constituting the fuel cell F, but when the power generation by the cell power generation unit 50 is not sufficient, the necessary power is supplied to the device. May not be able to supply. For example, when the cell power generation unit 50 is started up, when a large load is applied, or when the material for generating hydrogen gas has decreased. Therefore, in addition to the cell power generation unit 50, a small lithium battery 51 (corresponding to a rechargeable auxiliary battery (secondary battery)) is mounted as an auxiliary battery, and either the cell power generation unit 50 or the lithium battery 51 is selectively used. It can be switched to. Thereby, when the power supply by the cell power generation unit 50 is not sufficiently performed, the lithium battery 51 is configured to be connected to the device, and the device can be configured to always supply the power appropriately.

  A circuit configuration for realizing such a configuration is shown in FIG. Such a circuit can be mounted on the square circuit board 31 in the example of the first embodiment. Of course, it is not necessary to mount all the functions on the circuit board 31, and some functions may be mounted on the support substrate 30.

  In FIG. 10, the cell power generation unit 50 includes four unit cells U, which are connected in series. The lithium battery 51 corresponds to a rechargeable auxiliary battery, but a secondary battery other than the lithium battery 51 may be used.

  The voltage detection unit 52 (corresponding to the detection unit) constantly monitors the voltage values of the cell power generation unit 50 and the lithium battery 51 and determines which one should be connected to the power supply terminal 21 based on this voltage value. Have The detection unit according to the present invention may monitor the current value instead of monitoring the voltage value. The voltage level of the lithium battery 51 is, for example, about 3.7V to 5V, and the voltage level of the cell power generation unit 50 is, for example, 2.7V level using four unit cells U. By detecting these two voltage levels and performing a relative comparison, it is determined which should be connected to the power supply terminal 21. For example, when the voltage value of the cell power generation unit 50 is too low as compared with the voltage value of the lithium battery 51, the lithium battery 51 supplies power.

  The output voltage of the cell power generation unit 50 is boosted by the first booster circuit 53 so as to be a voltage suitable for the device. Similarly, the output voltage of the lithium battery 51 is boosted by the second booster circuit 54. These booster circuits 53 and 54 can adopt the same configuration, and can be configured by a known DC-DC converter.

  The 1st switch part 55 is provided with the switching function for performing the electric power supply by the cell electric power generation part 50 via the power supply terminal 21, and the cell electric power generation part 50 makes the electric power supply terminal 21 switch by switching a switch to a side. And electrically connected. The second switch unit 56 has a switching function for supplying power from the lithium battery 51 via the power supply terminal 21, and the lithium battery 51 is electrically connected to the power supply terminal 21 by switching to the b side. Connected. The switch units 54 and 55 can be configured using, for example, a power MOS-FET or other appropriate switching transistor.

  In FIG. 10, a diode 57 is connected between the output section of the first booster circuit 53 and the second switch section 56, and this path functions as a charging path for charging the lithium battery 51. That is, when power is supplied by the cell power generation unit 50, the switch is switched to the a side, and the lithium battery 51 is charged at the same time. By providing the diode 57, reverse charging from the lithium battery 51 to the cell power generation unit 50 is prevented, and power supply by the lithium battery 51 is not performed when power is supplied by the cell power generation unit 50. I have to.

  The switching control unit 58 controls the operation of the first switch unit 55 and the second switch unit 56 based on the detection result by the voltage detection unit 52, and the cell power generation unit 50 drives the device (load). In the state where the necessary power supply cannot be performed, the power supply by the lithium battery 51 is performed via the power supply terminal 21 by switching the switch portions 55 and 56 to the b side. At this time, the charging path to the lithium battery 51 is also disconnected by switching the second switch unit 56. When power can be supplied by the cell power generation unit 50, the switch is switched to the a side.

  The capacitor 59 is provided to absorb noise components generated during the switching operation of the switch units 55 and 56. For example, a super capacitor can be used.

  In addition, a drive circuit 60 is connected to the output section of the first booster circuit 53 to drive the fan 22 to rotate. That is, since the electric power generated by the cell power generation unit 50 is used to drive the fan 22, the fan 22 also rotates when the hydrogen gas is supplied and the electric power generation is started.

  In the above-described embodiment, the second switch unit 56 is configured to be switched to only one of the charging path and the power supply path, but may be configured to take a neutral state that is not in any position. Good. When power is supplied by the cell power generation unit 50, it may be overloaded to drive both the load on the device side and charge the lithium battery 51. In that case, the lithium battery 51 can be separated from the circuit by setting the neutral position.

<Experimental example>
Next, the effect by providing the fan 22 was confirmed by experiment. FIG. 11 is a graph showing experimental results. Experiments are performed in three types, A, B, and C. The fuel cell F used in Experiment A has a structure as shown in FIG. 12, and is different from the first embodiment described in FIG. The unit cell U is mounted outside the cylindrical frame constituted by the support substrate 30. There is no fan. In Experiments B and C, the structure having the fan 22 described in FIG. 1 and the like was used. In Experiment B, the experiment was performed without rotating the fan 22, and in Experiment C, the experiment was performed with the fan 22 rotated. Further, in order to measure the temperature of the unit cell U, a temperature sensor was attached to the connector 35 to which the unit cell U was attached, and the temperature was measured.

  As shown in the experimental results of FIG. 11, it can be seen that when the fan 22 is rotated (experiment C), a larger output (W) can be obtained than when the fan is not driven (experiments A and B). Further, looking at the cell temperature, it can be seen that the cell temperature is lowered by providing the fan 22.

  Considering the above points, it is considered that since the fan 22 can forcibly blow air to the cathode side of the unit cell U, the power generation efficiency in the unit cell U is increased and a large output is obtained. Moreover, it will be blowing also with respect to the surroundings of the hydrogen gas generation unit 40, the heat generation in the unit 40 can be suppressed, and as a result, each unit cell U is suppressed from being heated, In this respect as well, it is considered that the power generation efficiency could be improved. Incidentally, there is no significant difference between Experiments A and B, and it can be seen that the location of the unit cell U does not affect the power generation efficiency.

Second Embodiment
FIG. 13 is a diagram showing an internal configuration of the fuel cell F according to the second embodiment. The difference from the first embodiment is the size of the support substrate 30 and the arrangement of the power supply terminals 21. In the first embodiment, four unit cells U are mounted, but in the second embodiment, six unit cells U of the same size are mounted. The power supply terminal 21 is mounted on one of the support substrates 30. The point which comprises a cylindrical frame by couple | bonding the support substrate 30 and the point which arrange | positions the unit cell U inside a cylindrical frame are the same.

<Another embodiment>
Although various embodiments of the fuel cell have been described, the present invention is not limited to these embodiments. Although the four configuration examples of the number of support substrates 30 have been described, the present invention is not limited to this. For example, the support substrates 30 may be configured by three support substrates 30. In the case of three sheets, the cylindrical frame becomes a triangle. In the case of five, it becomes a pentagon. Further, the number of unit cells U to be mounted is not particularly limited, and an arbitrary number can be mounted. The number of unit cells U mounted on one support substrate 30 is also arbitrary. The number of unit cells U can be determined according to the device in which the fuel cell F is used. Further, the size of the unit cell U can be determined as appropriate.

  The device in which the fuel cell F according to the present invention is used is particularly suitable for portable devices, but is not limited to this, and can be used detachably with respect to various devices. Moreover, the usage purpose of the fuel cell F may be used as a main power source of the device, or may be used for the purpose of charging a secondary battery used in the device. Further, when the fuel cell F is attached to or detached from the device, the case where the fuel cell F is connected to the device via a connection cord instead of being directly attached to the device (terminal exposed to the outside of the device) is also included in the present invention. . Further, as exemplified by the USB terminal as the power supply terminal 21, it is preferable to provide the power supply terminal 21 so as to be detachable from the device. For example, it is preferable to have the same usability as a memory that can be detachably attached to a USB terminal.

  Although the cross-sectional shape of the main-body part 20 demonstrated the structural example formed in squares, such as a square and a rectangle, it is not limited to this, It can be made into various shapes. For example, it can be a polygon such as a hexagon or an octagon. Moreover, the shape of the main-body part 20 can be made into a cylindrical shape, an elliptical cylinder shape, and other arbitrary shapes. An R shape may be provided at the corner of the main body 20. Further, a clip may be attached to the main body unit 20 so as to be inserted into a pocket of an outer jacket.

  In this embodiment, although the opening window 20d is formed in the main-body part 20, the opening window 20d is not necessarily required as this invention. When the opening window 20d is formed, the shape, location, and number of the windows can be arbitrarily set.

  In addition, when arrange | positioning the support substrate 30 or the unit cell U along the wall surface part 20a as this invention, it is not limited to the structure which arrange | positions the support substrate 30 with respect to all the wall surface parts 20a. For example, in the configuration of FIG. 1, the support substrate 30 is disposed on all of the four wall surface portions 20a. For example, the support substrate 30 on which the unit cell U is mounted is disposed along the three wall surface portions 20a. May be. Further, it is not necessary to mount the unit cell U on all of the support substrates 30, and there may be a support substrate 30 on which the unit cells U are not mounted. In such a case, the circuit shown in FIG. 10 can be mounted on the support substrate 30.

The perspective view which shows the external appearance shape of the fuel cell concerning 1st Embodiment. The perspective view which shows the state which removed the main-body-part case Exploded perspective view showing internal configuration The longitudinal cross-sectional view which shows an example of the fuel battery cell of this invention Exploded perspective view showing the configuration of the main part Diagram showing configuration example of gas flow path Conceptual diagram showing a configuration example of a hydrogen gas generation unit The figure which shows the aspect when attaching or detaching a hydrogen gas generation unit Sectional drawing when the fuel cell according to the first embodiment is cut along a plane perpendicular to the axial direction. Diagram showing circuit configuration Graph showing experimental results The figure which shows the modification which changed the arrangement place of a unit cell The figure which shows the structure of the fuel cell concerning 2nd Embodiment.

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 hole 5 Anode side metal plate 11 Resin pipe 20 Main-body part 20a Wall surface part 20b 1st end surface part 20c 2nd end surface part 20d Opening Window 21 Power supply terminal 22 Fan 30 Support substrate 31 Circuit substrate 35 Connector 40 Hydrogen gas generation unit 50 Cell power generation unit 51 Drive circuit F Fuel cell U Unit cell

Claims (6)

An opening for taking in air is formed, and at least one unit cell provided for power generation;
A fuel cell comprising a fuel gas generator for generating fuel gas to be supplied to the unit cell,
A fuel cell comprising air blowing means for forcibly sending air toward the opening hole.   The fuel cell according to claim 1, wherein the air blown by the blower performs a cooling action on the fuel gas generation unit.   3. The fuel cell according to claim 1, further comprising a drive circuit that drives the blower unit with power generated by the at least one unit cell. 4.   4. The fuel cell according to claim 2, wherein a ventilation passage is formed between a surface of the unit cell where the opening hole is formed and an outer surface of the fuel gas generation unit.   The fuel cell according to any one of claims 1 to 4, wherein an opening window for taking air into the inside is provided in the vicinity of the blowing means.   The power supply system comprised from the fuel cell of any one of Claims 1-5, and the apparatus which receives power supply by this fuel cell.

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