JP2009238597A - Fuel cell - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a fuel cell capable of curtailing manufacturing cost, and yet, obtaining a stable output. <P>SOLUTION: Of the fuel cell, provided with a membrane electrode assembly 2 having an electrolyte membrane, a plurality of fuel electrodes arranged on one of the faces of the electrolyte membrane, and a plurality of air electrodes arranged on the other face of the electrolyte membrane and opposed to the respective fuel electrodes, and an insulating board F pinching the membrane electrode assembly 2, the insulating board F is provided with a collector 40 electrically connecting in series each pair of the fuel electrodes and the air electrodes of the membrane electrode assembly, and a temperature detecting means 50 detecting temperature on an insulating film BF. <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a fuel cell, and more particularly to a fuel cell including a current collector that collects current by contacting an electrode of a membrane electrode assembly.

  In recent years, attempts have been made to use a fuel cell as a power source for portable electronic devices such as notebook computers and mobile phones so that they can be used for a long time without being charged. A fuel cell is characterized in that it can generate electric power simply by supplying fuel and air, and can generate electric power continuously for a long time if fuel is replenished. For this reason, if the fuel cell can be reduced in size, it can be said that the system is extremely advantageous as a power source for portable electronic devices.

  For example, a direct methanol fuel cell (DMFC) using methanol as a fuel can be reduced in size and can be easily handled, and thus is regarded as a promising power source for portable electronic devices. Yes. As the liquid fuel supply method in the DMFC, there are known an active method such as a gas supply type and a liquid supply type, and a passive method such as an internal vaporization type in which the liquid fuel in the fuel container is vaporized inside the cell and supplied to the fuel electrode. It has been.

  Among these, passive methods such as an internal vaporization type are advantageous for downsizing the DMFC. In the passive type DMFC, for example, a structure in which a membrane electrode assembly (MEA) having a fuel electrode, an electrolyte membrane, and an air electrode is arranged on a fuel storage portion formed of a box-like container has been proposed (for example, , See Patent Document 1). In addition, it has been studied to connect a DMFC fuel cell and a fuel storage part via a flow path (see, for example, Patent Documents 2 and 3).

  By the way, since the voltage obtained from the fuel cell is usually minute, it is often used after being boosted by a DC / DC converter. In order to increase the efficiency of boosting at that time, it is common practice to increase the voltage of a fuel cell by connecting electrodes in series using a current collector. As a current collector, for example, as disclosed in Patent Document 4, a structure in which a cathode conductive layer and an anode conductive layer are integrated on a single insulating film has been proposed.

On the other hand, when trying to measure the temperature inside the cell in the fuel cell, for example, as described in Patent Document 5, a part of the conductive pattern formed on the flexible base film functions as a sensor. A technique for applying a flexible printed circuit board provided with the above has been proposed.
International Publication No. 2005/112172 Pamphlet JP 2005-518646 A JP 2006-089552 A International Publication No. 2006/057283 Pamphlet JP 2005-328003 A

  In order to take out the electrons collected by the current collector to an external circuit board, it is necessary to perform a complicated operation such as connecting the output terminal of the current collector to an electric wire connected to the circuit board using solder or the like. There is.

  An object of the present invention is to provide a fuel cell capable of reducing the manufacturing cost and obtaining a stable output.

A fuel cell according to an aspect of the present invention includes:
Membrane electrode joint comprising an electrolyte membrane, a plurality of fuel electrodes disposed on one surface of the electrolyte membrane, and a plurality of air electrodes disposed on the other surface of the electrolyte membrane and facing each of the fuel electrodes Body,
An insulating substrate sandwiching the membrane electrode assembly;
A fuel cell comprising:
The insulating substrate comprises: a current collector that electrically connects each set of the fuel electrode and the air electrode of the membrane electrode assembly on an insulating film; and a temperature detection unit that detects temperature. It is characterized by having.

  According to the present invention, it is possible to provide a fuel cell capable of reducing the manufacturing cost and obtaining a stable output.

  A technique related to a fuel cell according to an embodiment of the present invention will be described below with reference to the drawings.

  FIG. 1 is a cross-sectional view schematically showing a main part of a fuel cell 1 according to this embodiment.

  The fuel cell 1 mainly includes a membrane electrode assembly (MEA) 2 that constitutes an electromotive unit, a fuel supply mechanism 3 that supplies fuel to the membrane electrode assembly 2, and a fuel storage unit 4 that stores liquid fuel. Has been.

  That is, in the fuel cell 1, the membrane electrode assembly 2 includes an anode (fuel electrode) 13 having an anode catalyst layer 11 and an anode gas diffusion layer 12, and a cathode (cathode catalyst layer 14 and cathode gas diffusion layer 15). (Air electrode / oxidant electrode) 16 and a proton (hydrogen ion) conductive electrolyte membrane 17 sandwiched between the anode catalyst layer 11 and the cathode catalyst layer 14.

  Examples of the catalyst contained in the anode catalyst layer 11 and the cathode catalyst layer 14 include platinum such as platinum (Pt), ruthenium (Ru), rhodium (Rh), iridium (Ir), osmium (Os), and palladium (Pd). Examples thereof include a group element simple substance and an alloy containing a platinum group element. For the anode catalyst layer 11, it is preferable to use Pt—Ru, Pt—Mo, or the like that has strong resistance to methanol, carbon monoxide, or the like. It is preferable to use Pt, Pt—Ni or the like for the cathode catalyst layer 14.

  However, the catalyst is not limited to these, and various substances having catalytic activity can be used. The catalyst may be either a supported catalyst using a conductive carrier such as a carbon material or an unsupported catalyst.

  Examples of the proton conductive material constituting the electrolyte membrane 17 include fluorine-based resins such as perfluorosulfonic acid polymer having a sulfonic acid group (Nafion (trade name, manufactured by DuPont) and Flemion (trade name, manufactured by Asahi Glass Co., Ltd.). Etc.), organic materials such as hydrocarbon resins having sulfonic acid groups, or inorganic materials such as tungstic acid and phosphotungstic acid. However, the proton conductive electrolyte membrane 17 is not limited to these.

  The anode catalyst layer 11 is disposed on the electrolyte membrane 17. The anode gas diffusion layer 12 is laminated on the anode catalyst layer 11. The anode gas diffusion layer 12 serves to uniformly supply fuel to the anode catalyst layer 11. The cathode catalyst layer 14 is disposed on the electrolyte membrane 17. The cathode gas diffusion layer 15 is laminated on the cathode catalyst layer 14. The cathode gas diffusion layer 15 serves to uniformly supply the oxidant to the cathode catalyst layer 14. These anode gas diffusion layer 12 and cathode gas diffusion layer 15 are made of a porous substrate having conductivity such as carbon paper or carbon fiber.

  A conductive layer is laminated on the anode gas diffusion layer 12 and the cathode gas diffusion layer 15 as necessary. These conductive layers include, for example, a mesh made of a conductive metal material such as gold (Au), a porous film, a thin film or a foil, or a conductive metal material such as stainless steel (SUS) and a good conductivity such as gold. A composite material coated with a conductive metal is used.

  The membrane electrode assembly 2 is sealed by a seal member 19 such as a rubber O-ring disposed on the anode side and the cathode side of the electrolyte membrane 17, thereby preventing fuel leakage from the membrane electrode assembly 2. Oxidant leakage is prevented.

  A plate-like body 20 made of an insulating material is disposed on the cathode 16 side of the membrane electrode assembly 2. This plate-like body 20 mainly functions as a moisture retaining layer. That is, the plate-like body 20 is impregnated with a part of the water generated in the cathode catalyst layer 14 to suppress the transpiration of water, adjusts the amount of air taken into the cathode catalyst layer 14 and makes the air uniform. Promotes diffusion. The plate-like body 20 is an insulating layer having a thermal conductivity lower than that of the cathode gas diffusion layer 15 or a layer having a high resistance corresponding thereto. For example, the plate-like body 20 is composed of a porous structure member. And a porous body of polypropylene.

  In this embodiment, the membrane electrode assembly 2 includes a plurality of anodes 13 disposed on one surface 17A of the same electrolyte membrane 17 and a plurality of anodes 17 disposed on the other surface 17B of the electrolyte membrane 17. Each anode 13 and each cathode 16 are opposed to each other with the electrolyte membrane 17 interposed therebetween. That is, each set of the anode 13 and the cathode 16 constitutes a single cell C, and each of them is arranged separately on the plane of the electrolyte membrane 17.

  In the example shown in FIGS. 2 and 3, the membrane / electrode assembly 2 includes four anodes 131 to 134 disposed on one surface 17 </ b> A of the single electrolyte membrane 17 and the other surface of the electrolyte membrane 17. And four cathodes 161 to 164 arranged in 17B. The anode 131 and the cathode 161 are arranged so as to face each other, and constitute a set of single cells C. Similarly, the anode 132 and the cathode 162 are arranged so as to face each other, the anode 133 and the cathode 163 are arranged so as to face each other, and the anode 134 and the cathode 164 are arranged so as to face each other. Four sets of single cells C are arranged on the same plane.

  The fuel cell 1 includes a current collector 40 that electrically connects each set of the anode 13 and the cathode 16 in series. The structure of the current collector 40 will be described in detail later.

  The membrane electrode assembly 2 described above is sandwiched between the insulating substrates F and disposed between the fuel supply mechanism 3 and the cover plate 21. The cover plate 21 has a substantially box-like appearance and is made of, for example, stainless steel (SUS). The cover plate 21 has a plurality of openings (air introduction holes) 21A for taking in air as an oxidant.

  The fuel supply mechanism 3 includes a container 30 formed in a box shape, and is connected to the fuel storage unit 4 via the flow path 5. That is, the container 30 has a fuel inlet 30A, and the fuel inlet 30A and the flow path 5 are connected.

  The container 30 is constituted by a resin container, for example. The material forming the container 30 preferably has methanol resistance and the like. Examples of the resin material forming the container 30 include polyethylene naphthalate, polyethylene terephthalate, cyclic olefin copolymer, cycloolefin polymer, polymethylpentene, and polyphenylsulfone. However, the container 30 made of an olefin resin such as a general polyethylene resin or polypropylene resin is not excluded.

  The fuel supply mechanism 3 includes a fuel supply unit 31 that supplies fuel while dispersing and diffusing fuel in the surface direction of the anode 13 of the membrane electrode assembly 2. In this embodiment, the fuel supply unit 31 includes the fuel distribution plate 31A, but may have other configurations.

  That is, as shown in FIGS. 4 and 5, the fuel distribution plate 31 </ b> A has at least one fuel injection port 32 and a plurality of fuel discharge ports 33, via a fuel passage such as a narrow tube 34. The fuel injection port 32 and the fuel discharge port 33 are connected. The fuel passage may be constituted by a fuel flow groove or the like instead of the narrow tube 34 formed in the fuel distribution plate 31A. In this case, the fuel distribution plate 31A can also be configured by covering the flow path plate having the fuel flow grooves with a diffusion plate having a plurality of fuel discharge ports.

  In the example shown in FIGS. 4 and 5, the fuel inlet 32 is in one place and communicates with the fuel inlet 30 </ b> A of the container 30. As a result, the fuel inlet 32 of the fuel distribution plate 31 </ b> A is connected to the fuel storage portion 4 via the flow path 5. There are 128 fuel discharge ports 33 for discharging liquid fuel or vaporized components thereof.

  A fuel injection port 32 is provided at one end (starting end) of the thin tube 34. The narrow tube 34 is branched into a plurality of parts along the way, and a fuel discharge port 33 is provided at each terminal portion of the branched narrow tube 34. The thin tube 34 is preferably a through hole having an inner diameter of 0.05 to 5 mm, for example.

  The liquid fuel injected from the fuel injection port 32 is guided to the plurality of fuel discharge ports 33 via the thin tubes 34 branched into a plurality. By using such a fuel distribution plate 31A, the liquid fuel injected from the fuel injection port 32 can be evenly distributed to the plurality of fuel discharge ports 33 regardless of the direction or position. Therefore, the uniformity of the power generation reaction in the surface of the membrane electrode assembly 2 can be further enhanced.

  Further, by connecting the fuel injection port 32 and the plurality of fuel discharge ports 33 with the thin tube 34, it is possible to design such that more fuel is supplied to a specific location of the fuel cell. This contributes to improvement in the uniformity of the power generation degree of the membrane electrode assembly 2 and the like.

  The membrane electrode assembly 2 is arranged so that the anode 13 faces the fuel discharge port 33 of the fuel distribution plate 31A as described above. The cover plate 21 is fixed to the container 30 by a method such as caulking or screwing in a state where the membrane electrode assembly 2 is held between the cover plate 21 and the fuel supply mechanism 3. Thereby, the power generation unit of the fuel cell (DMFC) 1 is configured.

  The fuel supply unit 31 is preferably configured to form a space functioning as a fuel diffusion chamber 31B between the fuel distribution plate 31A and the membrane electrode assembly 2. The fuel diffusion chamber 31 </ b> B has a function of promoting vaporization and promoting diffusion in the surface direction even when liquid fuel is discharged from the fuel discharge port 33.

  A support member that supports the membrane electrode assembly 2 from the anode 7 side may be disposed between the membrane electrode assembly 2 and the fuel supply unit 31.

  Further, at least one porous body may be disposed between the membrane electrode assembly 2 and the fuel supply unit 31.

  Liquid fuel corresponding to the membrane electrode assembly 2 is stored in the fuel storage portion 4.

  Examples of the liquid fuel include methanol fuels such as aqueous methanol solutions of various concentrations and pure methanol. The liquid fuel is not necessarily limited to methanol fuel. The liquid fuel may be, for example, an ethanol fuel such as an ethanol aqueous solution or pure ethanol, a propanol fuel such as a propanol aqueous solution or pure propanol, a glycol fuel such as a glycol aqueous solution or pure glycol, dimethyl ether, formic acid, or other liquid fuel. In any case, liquid fuel corresponding to the membrane electrode assembly 2 is stored in the fuel storage portion 4.

  Further, a pump 6 may be interposed in the flow path 5. The pump 6 is not a circulation pump that circulates fuel, but is a fuel supply pump that sends liquid fuel from the fuel storage unit 4 to the fuel supply unit 31 to the last. The fuel supplied from the fuel supply unit 31 to the membrane electrode assembly 2 is used for a power generation reaction, and is not circulated thereafter and returned to the fuel storage unit 4.

  The fuel cell 1 of this embodiment is different from the conventional active method because it does not circulate the fuel, and does not impair the downsizing of the device. Further, the pump 6 is used to supply the liquid fuel, which is different from a pure passive system such as a conventional internal vaporization type. The fuel cell 1 shown in FIG. 1 employs a system called a semi-passive type, for example.

  The type of the pump 6 is not particularly limited, but a rotary vane pump, an electroosmotic pump, and a diaphragm pump can be used from the viewpoint that a small amount of liquid fuel can be fed with good controllability and can be reduced in size and weight. It is preferable to use a squeezing pump or the like.

  The rotary vane pump feeds liquid by rotating wings with a motor. The electroosmotic flow pump uses a sintered porous body such as silica that causes an electroosmotic flow phenomenon. A diaphragm pump drives a diaphragm with an electromagnet or piezoelectric ceramics to send liquid. The squeezing pump presses a part of a flexible fuel flow path and squeezes the fuel. Among these, it is more preferable to use an electroosmotic pump or a diaphragm pump having piezoelectric ceramics from the viewpoint of driving power, size, and the like.

  A reservoir may be provided between the pump 6 and the fuel supply unit 31.

  Further, in order to improve the stability and reliability of the fuel cell 1, a fuel cutoff valve may be arranged in series with the pump 6. As the fuel cutoff valve, an electrically driven valve capable of controlling an opening / closing operation with an electric signal using an electromagnet, a motor, a shape memory alloy, piezoelectric ceramics, bimetal, or the like as an actuator is applied. The fuel cutoff valve is preferably a latch type valve having a state maintaining function.

  Further, a balance valve that balances the pressure in the fuel storage unit 4 with the outside air may be attached to the fuel storage unit 4 and the flow path 5. When fuel is supplied from the fuel storage unit 4 to the membrane electrode assembly 2 by the fuel supply mechanism 3, it is possible to adopt a configuration in which only the fuel cutoff valve is arranged instead of the pump 6. The fuel cutoff valve at this time is provided for controlling the supply of liquid fuel through the flow path 5.

  In the fuel cell 1 of this embodiment, liquid fuel is intermittently sent from the fuel storage unit 4 to the fuel supply unit 31 using the pump 6. The liquid fuel fed by the pump 6 is uniformly supplied to the entire surface of the anode 13 of the membrane electrode assembly 2 through the fuel supply unit 31.

  That is, the fuel is uniformly supplied to the planar direction of each anode 13 of the plurality of single cells C, thereby generating a power generation reaction. The operation of the fuel supply (liquid feeding) pump 6 is preferably controlled based on the output of the fuel cell 1, temperature information, operation information of an electronic device that is a power supply destination, and the like.

  As described above, the fuel released from the fuel supply unit 31 is supplied to the anode 13 of the membrane electrode assembly 2. In the membrane electrode assembly 2, the fuel diffuses through the anode gas diffusion layer 12 and is supplied to the anode catalyst layer 11. When methanol fuel is used as the liquid fuel, an internal reforming reaction of methanol shown in the following formula (1) occurs in the anode catalyst layer 11. When pure methanol is used as the methanol fuel, the water generated in the cathode catalyst layer 14 or the water in the electrolyte membrane 17 is reacted with methanol to cause the internal reforming reaction of the formula (1). Alternatively, the internal reforming reaction is caused by another reaction mechanism that does not require water.

CH ₃ OH + H ₂ O → CO ₂ + 6H ⁺ + 6e ⁻ (1)
The electrons (e ⁻ ) generated by this reaction are guided to the outside via the current collector 40, and after operating a portable electronic device or the like as so-called electricity, the electrons (e ⁻ ) are passed to the cathode 16 via the current collector 40. Led. Proton (H ⁺ ) generated by the internal reforming reaction of the formula (1) is guided to the cathode 16 through the electrolyte membrane 17. Air is supplied to the cathode 16 as an oxidant. Electrons (e ⁻ ) and protons (H ⁺ ) that have reached the cathode 16 react with oxygen in the air in the cathode catalyst layer 14 according to the following formula (2), and water is generated with this reaction.

6e ⁻ + 6H ⁺ + (3/2) O ₂ → 3H ₂ O (2)
In the power generation reaction of the fuel cell 1 described above, in order to increase the power to be generated, the catalyst reaction is smoothly performed and the fuel is uniformly supplied to the entire electrode of the membrane electrode assembly 2 to make the entire electrode more effective. It is important to contribute to power generation.

  By the way, as shown in FIGS. 6 and 7, the insulating substrate F applicable in this embodiment has an area approximately twice the outer dimension of the membrane electrode assembly 2 and is folded in two. Thus, the membrane electrode assembly 2 is sandwiched. The insulating substrate F includes an insulating film BF as a base, a conductive layer CL patterned on at least one surface of the insulating film BF, and a cover film CF that covers the conductive layer CL. Yes.

  The insulating film BF and the cover film CF are preferably formed of a material having corrosion resistance against the fuel used or a product generated by a power generation reaction, and is formed of, for example, polyimide. The material of the insulating film BF and the cover film CF is not limited to polyimide (PI), but is a thermoplastic polyester resin material such as polyethylene terephthalate (PET) having electrical insulation, polyetherimide, polyetheretherketone (PEEK). : Various types of resin materials such as Victorex PLC, perfluoro resin, fluororesin, polyethylene (PE), polyethylene naphthalate (PEN), polypropylene (PP), and polyphenylene sulfide (PPS) can be used.

  The conductive layer CL is formed of, for example, copper (Cu) and is covered with a conductive film having corrosion resistance. In this embodiment, in the conductive layer CL, the copper foil is covered with nickel (Ni), and the surface of the nickel film is further covered with gold (Au). That is, the surface of the conductive layer CL is formed of gold (Au).

  In particular, in this embodiment, the insulating substrate F includes a current collector 40 as the conductive layer CL. The current collector 40 has a plurality of first electrode portions 41 and a plurality of second electrode portions 42. The first electrode portion 41 and the second electrode portion 42 are disposed on the same surface on the insulating film BF. In addition, at least some of the surfaces (here, gold foil) of the first electrode portion 41 and the second electrode portion 42 are exposed from the cover film CF.

  The first electrode portion 41 corresponds to an anode current collector provided corresponding to each of the anodes 13 and is provided in the same number as the anodes 13 included in the membrane electrode assembly 2. The second electrode portion 42 corresponds to a cathode current collector provided corresponding to each of the cathodes 16 and is provided in the same number as the cathodes 16 included in the membrane electrode assembly 2.

  In the example illustrated in FIG. 6, the current collector 40 includes four first electrode portions 411 to 414 and four second electrode portions 421 to 424. The first electrode portion 411 is disposed corresponding to the anode 131, and similarly, the first electrode portion 412 is disposed corresponding to the anode 132, the first electrode portion 413 is disposed corresponding to the anode 133, The electrode portion 414 is disposed corresponding to the anode 134. The second electrode portion 421 is disposed corresponding to the cathode 161. Similarly, the second electrode portion 422 is disposed corresponding to the cathode 162, the second electrode portion 423 is disposed corresponding to the cathode 163, and the second The electrode portion 424 is disposed corresponding to the cathode 164.

  In such a current collector 40, the first electrode portion 41 and the second electrode portion 42 are formed in shapes that come into contact with the corresponding anode 13 and cathode 16, respectively. The portion of the first electrode portion 41 exposed from the cover film CF is in contact with the anode 13, particularly the anode gas diffusion layer 12. Further, the portion of the second electrode portion 42 exposed from the cover film CF is in contact with the cathode 16, particularly the cathode gas diffusion layer 15. That is, the surfaces of the first electrode portion 41 and the second electrode portion 42 that are in contact with the membrane electrode assembly 2 are made of gold (Au). Gold foil is more preferable as a material for forming an electrode surface because it has a relatively low electric resistance and a strong corrosion resistance that can withstand a corrosive atmosphere generated by a power generation reaction.

  The insulating substrate F includes output terminals 46 and 47 connected to the current collector 40. That is, in the current collector 40, output terminals 46 and 47 for extracting collected electrons are respectively connected to the first electrode portion 411 and the second electrode portion 424 which are arranged at positions farthest from each other. These output terminals 46 and 47 are exposed from the cover film CF.

  The first electrode portion 41 and the second electrode portion 42 that do not have an output terminal are each electrically connected by a connecting portion 48. In the example shown in FIG. 6, the first electrode portion 412 and the second electrode portion 421 are connected by the connecting portion 481, and similarly, the first electrode portion 413 and the second electrode portion 422 are connected by the connecting portion 482. The first electrode part 414 and the second electrode part 423 are connected by a connecting part 483.

  In the insulating substrate F including the current collector 40 having the above-described structure, the membrane electrode assembly 2 is accommodated in the inner space folded in half. That is, each of the first electrode portions 41 is electrically connected to the corresponding anode 13, and each of the second electrode portions 42 is electrically connected to the corresponding cathode 16. Therefore, the membrane electrode assembly 2 is sandwiched.

  The insulating substrate F preferably has a hole that penetrates the insulating film BF. In the example illustrated in FIG. 6, the insulating substrate F passes through the insulating film BF between the adjacent first electrode portions 41 or between the adjacent second electrode portions 42 to release a gas component generated by the power generation reaction. A gas supply hole 41H, a first electrode portion 41, and a gas supply hole 41H for exposing the anode gas diffusion layer 12 through the gas vent hole H, the first electrode portion 41, and the insulating film BF to supply fuel to the anode catalyst layer 11. The cathode gas diffusion layer 15 is exposed through the insulating film BF, and air introduction holes 42H for supplying air to the cathode catalyst layer 14 are provided.

  Incidentally, the insulating substrate F described above includes a temperature detection unit 50 that detects the temperature in addition to the current collector 40. This temperature detector 50 is mainly used to detect the temperature of the membrane electrode assembly 2. In the example shown in FIG.6 and FIG.8, the temperature detection part 50 is arrange | positioned on the same surface as the surface where the collector 40 of the insulating film BF is arrange | positioned.

  Such a temperature detection unit 50 includes, as the conductive layer CL, a signal wiring 51 that can be formed of the same material as the current collector 40 and a detection element 52 connected to the signal wiring 51. The signal wiring 51 is disposed between the electrode portions constituting the current collector 40 on the insulating film BF. In the example shown here, the signal wiring 51 is disposed between the second electrode portions 42. The signal wiring 51 is covered with a cover film CF. One end side of the signal wiring 51 is exposed from the cover film CF.

  The detection element 52 is configured by, for example, a thermistor. The detection element 52 is electrically connected to one end side of the signal wiring 51 exposed from the cover film CF. That is, in the example shown here, the detection element 52 is disposed between the second electrode portions 42. Note that the signal wiring 51 and the detection element 52 may be disposed between the first electrode portions 41.

  Further, the insulating substrate F includes an output terminal 53 connected to the other end of the signal wiring 51. The output terminal 53 is exposed from the cover film CF. With such a configuration, in the temperature detection unit 50, a signal corresponding to the detection result detected by the detection element 52 can be taken out from the output terminal 53 via the signal wiring 51.

  As described above, according to the insulating substrate F applied in this embodiment, the temperature detector 50 can be integrated with the current collector 40 on the insulating film. For this reason, by sandwiching the membrane electrode assembly 2 by the insulating substrate F, it becomes possible to collect current by connecting a plurality of single cells C in the membrane electrode assembly 2 in series by the current collector 40, and The temperature detector 50 can detect the temperature at a predetermined position of the membrane electrode assembly 2. For this reason, the assembly operation of the fuel cell 1 becomes easy, the manufacturing cost can be reduced, and the output can be stably obtained.

  In addition, the temperature detector 50 can be fixedly disposed at a predetermined position, and the temperature at a desired position in the membrane electrode assembly 2 can be stably detected.

  Furthermore, the output terminals 46 and 47 connected to the current collector 40 and the output terminal 53 connected to the temperature detection unit 50 can be directly connected to an external circuit board (including a power supply circuit) by a connector. It becomes possible. For this reason, complicated connection work using solder or the like is not required, and the assembly work of the fuel cell 1 is facilitated.

  The temperature detection unit 50 is not limited to the example illustrated in FIG. 6, and may be disposed on a surface different from the surface on which the current collector 40 of the insulating film BF is disposed. In the example shown in FIGS. 9 and 10, in the insulating substrate F, the current collector 40 is disposed on one surface BFa of the insulating film BF, whereas the temperature detection unit 50 is formed of the insulating film BF. Arranged on the other surface BFb.

  The current collector 40 and the temperature detection unit 50 are configured in the same manner as in the example illustrated in FIG. 6, but the arrangement position of the temperature detection unit 50 is not particularly limited. That is, similarly to the example shown in FIG. 6, the signal wiring 51 and the detection element 52 may be disposed on the back side surface BFb at a position corresponding to the space between the electrode portions constituting the current collector 40. It may be arranged on the surface BFb on the back side of the part.

  According to such an insulating substrate F, in addition to the above-described effects, the degree of freedom in layout of the temperature detection unit 50 can be further improved.

  A plurality of temperature detection units 50 may be arranged on a single insulating substrate F. As shown in FIG. 11, when a plurality of temperature detection units 50 are arranged on the insulating film BF, the signal wirings 51 are routed on the insulating film BF to be integrated into one output terminal 53. Is desirable.

  The fuel cell 1 of each embodiment described above is effective when various liquid fuels are used, and the type and concentration of the liquid fuel are not limited. However, the fuel supply unit 31 that supplies fuel while being dispersed in the plane direction is particularly effective when the fuel concentration is high. For this reason, the fuel cell 1 of each embodiment can exhibit its performance and effects particularly when methanol having a concentration of 80 wt% or more is used as the liquid fuel. Therefore, each embodiment is suitable for the fuel cell 1 using a methanol aqueous solution having a methanol concentration of 80 wt% or more or pure methanol as a liquid fuel.

  Furthermore, although each embodiment mentioned above demonstrated the case where this invention was applied to the semi-passive type fuel cell 1, this invention is not limited to this, It is an internal vaporization type pure passive type fuel cell. It can also be applied to.

  The present invention can be applied to various fuel cells using liquid fuel. In addition, the specific configuration of the fuel cell, the supply state of the fuel, and the like are not particularly limited, and all of the fuel supplied to the MEA is liquid fuel vapor, all is liquid fuel, or part is liquid state. The present invention can be applied to various forms such as a vapor of supplied liquid fuel. In the implementation stage, the constituent elements can be modified and embodied without departing from the technical idea of the present invention. Furthermore, various modifications are possible, such as appropriately combining a plurality of constituent elements shown in the above embodiment, or deleting some constituent elements from all the constituent elements shown in the embodiment. Embodiments of the present invention can be expanded or modified within the scope of the technical idea of the present invention, and these expanded and modified embodiments are also included in the technical scope of the present invention.

FIG. 1 is a cross-sectional view schematically showing a configuration of a fuel cell according to an embodiment of the present invention. FIG. 2 is a plan view schematically showing the appearance of the membrane electrode assembly in the fuel cell shown in FIG. FIG. 3 is a perspective view when the membrane electrode assembly shown in FIG. 2 is cut along the line III-III. FIG. 4 is a perspective view schematically showing the structure of the fuel distribution plate of the fuel supply unit in the fuel supply mechanism applicable to the fuel cell shown in FIG. FIG. 5 is a plan view of the fuel distribution plate shown in FIG. FIG. 6 is a plan view schematically showing the structure of an insulating substrate applicable to the fuel cell according to one embodiment of the present invention. FIG. 7 is a cross-sectional view when the insulating substrate shown in FIG. 6 is cut along the line VII-VII. 8 is a cross-sectional view when the insulating substrate shown in FIG. 6 is cut along the line VIII-VIII. FIG. 9 is a plan view schematically showing another structure of the insulating substrate applicable to the fuel cell according to the embodiment of the present invention. 10 is a cross-sectional view of the insulating substrate shown in FIG. 6 taken along line XX. FIG. 11 is a plan view schematically showing another structure of the insulating substrate applicable to the fuel cell according to the embodiment of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Fuel cell 2 ... Membrane electrode assembly 3 ... Fuel supply mechanism 4 ... Fuel accommodating part 11 ... Anode catalyst layer 12 ... Anode gas diffusion layer 13 ... Anode (fuel electrode)
14 ... Cathode catalyst layer 15 ... Cathode gas diffusion layer 16 ... Cathode (air electrode)
DESCRIPTION OF SYMBOLS 17 ... Electrolyte membrane 20 ... Plate-shaped body (moisturizing layer) 21 ... Cover plate 21A ... Opening part F ... Insulating substrate BF ... Insulating film CF ... Cover film CL ... Conductive layer 40 ... Current collector 41 ... 1st electrode part 42 ... 2nd electrode part 46, 47 ... Output terminal 48 ... Connection part 50 ... Temperature detection part 51 ... Signal wiring 52 ... Detection element 53 ... Output terminal

Claims (10)

Membrane electrode joint comprising an electrolyte membrane, a plurality of fuel electrodes disposed on one surface of the electrolyte membrane, and a plurality of air electrodes disposed on the other surface of the electrolyte membrane and facing each of the fuel electrodes Body,
An insulating substrate sandwiching the membrane electrode assembly;
A fuel cell comprising:
The insulating substrate comprises: a current collector that electrically connects each set of the fuel electrode and the air electrode of the membrane electrode assembly on an insulating film; and a temperature detection unit that detects temperature. A fuel cell comprising the fuel cell.   2. The fuel cell according to claim 1, wherein the temperature detection unit is disposed on the same surface as the surface on which the current collector of the insulating film is disposed.   2. The fuel cell according to claim 1, wherein the temperature detection unit is disposed on a surface different from a surface on which the current collector of the insulating film is disposed.   The fuel cell according to claim 1, wherein the insulating substrate includes an output terminal connected to the current collector and the temperature detection unit.   On the same surface of the insulating film, the current collector has a plurality of first electrode portions that contact each of the fuel electrodes in the membrane electrode assembly, and a plurality of second electrodes that contact each of the air electrodes. 2. The fuel cell according to claim 1, further comprising: an electrode part; and a connecting part that connects the first electrode part and the second electrode part.   6. The fuel cell according to claim 5, wherein surfaces of the first electrode portion and the second electrode portion that are in contact with the membrane electrode assembly are formed of gold (Au).   The fuel cell according to claim 5, wherein the insulating substrate has a hole penetrating the insulating film.   The fuel cell according to claim 1, further comprising a fuel supply mechanism that supplies fuel to the membrane electrode assembly and a fuel storage unit that stores liquid fuel.   The fuel cell according to claim 1, wherein the fuel supplied to the membrane electrode assembly is methanol fuel.   The fuel cell according to claim 9, wherein the methanol fuel is a methanol aqueous solution or pure methanol having a methanol concentration of 80 wt% or more.

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