JP2007323932A - Fuel cell module and connector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To restrain degradation of performance in a state in which a fuel cell module is not in use. <P>SOLUTION: The fuel cell module 100 is provided with an electrolyte film, a DMFC 10 equipped with an anode electrode fitted on one face of the electrolyte film, a cathode electrode fitted on the other face of the electrolyte film, a power connecting part 54 fitted at the DMFC 10 and connected with an equipment electrically connected with the DMFC 10 in free detachment, and an air-supply channel switching member 56 fitted at the DMFC 10 and opening and closing an air-supply channel where reaction fluid supplied to the anode electrode passes in accordance with a connection state of the power connecting part 54. With this, degradation of performance is restrained in a state in which the fuel cell module 100 is not in use. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a liquid fuel direct supply type fuel cell module connectable to a device or a connector.

  A fuel cell is a device that generates electrical energy from fuel and oxidant, and can achieve high power generation efficiency. The main feature of a fuel cell is direct power generation that does not go through the process of thermal energy or kinetic energy as in the conventional power generation method. For this reason, fuel cells can be expected to have high power generation efficiency even on a small scale. In addition, since the fuel cell emits less nitride compound and the noise and vibration are small, the influence on the environment can be reduced. As described above, since the fuel cell can effectively use the chemical energy of the fuel and has environmentally friendly characteristics, it is expected as an energy supply system for the 21st century. Therefore, fuel cells are attracting attention as a promising new power generation system that can be used in various applications from space use to automobiles and portable devices, from large-scale power generation to small-scale power generation. It is in full swing.

  In addition, as fuel cells are being reduced in size and weight, application development as a power source for portable devices is being promoted. For example, in recent years, a direct methanol fuel cell (hereinafter referred to as “DMFC”) has attracted attention as one form of fuel cell. The DMFC directly supplies methanol to the anode without reforming the fuel, and obtains electric power through an electrochemical reaction between methanol and oxygen. Methanol has higher energy per unit volume than hydrogen, is suitable for storage, and is easy to handle, so it is expected to be used as a power source for automobiles and portable devices.

The power supply voltage required for a portable device often varies from device to device. Patent Document 1 includes a battery pack that incorporates a battery and a DC / DC converter that converts an output voltage of the battery according to an output voltage command value in order to supply a voltage according to the load of the device to the load. A portable power supply is disclosed.
JP 2004-319367 A

  However, if a DC / DC converter is built in each battery pack, the cost of the entire battery pack is increased. In addition, devices that can be connected to a battery pack are limited by a DC / DC converter built in the battery pack.

  Further, DMFCs that are attracting attention as power sources for portable devices require oxygen in the course of the reaction, and carbon dioxide is generated as a result of the reaction. Therefore, DMFC may be provided with an intake port for taking in oxygen necessary for the cathode electrode and an exhaust port for discharging carbon dioxide generated at the anode electrode. However, in such a case, there is a problem that fuel or water used for the reaction evaporates from the suction port or the discharge port or the membrane dries in a state where DMFC is not used. In particular, the influence is increased in a so-called passive type DMFC that does not have a forced supply means such as a pump for supplying fuel to the anode electrode.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a low-cost fuel cell module that can be connected to equipment.

  Another object of the present invention is to provide a technique for suppressing performance deterioration in a state where a fuel cell module is not used.

  In order to solve the above problems, a fuel cell module according to an aspect of the present invention is provided with an electrolyte membrane, a first electrode provided on one surface of the electrolyte membrane, and the other surface of the electrolyte membrane. A fuel cell having a second electrode; a connection portion provided in the fuel cell, electrically connected to the fuel cell and detachably connected to the fuel cell; and the fuel cell. An air supply path opening / closing member provided to open and close an air supply path through which a reaction fluid supplied to the first electrode passes according to a connection state of the connection portion.

  According to this aspect, the air supply path through which the reaction fluid supplied to the first electrode passes can be opened and closed in accordance with the connection state of the connection portion provided in the fuel cell module. Therefore, for example, in the state of the fuel cell module alone without being connected to the device, the air supply path can be closed, and when the fuel cell module is stored or transported, intrusion of foreign matter or drying of the electrolyte membrane is prevented. Can be suppressed. In addition, when a fuel cell module is connected to a device or a connector as a power source for the device to be used, the air supply path that has been closed until then is opened. For example, air that is an oxidant as a reaction fluid necessary for power generation The oxygen therein can be supplied to the first electrode via the air supply path.

  Another embodiment of the present invention is also a fuel cell module. The fuel cell module includes an electrolyte membrane, a first electrode provided on one surface of the electrolyte membrane, and a second electrode provided on the other surface of the electrolyte membrane; A connection portion provided in the fuel cell, connected to a device that is electrically connected to the fuel cell and is detachably connected, and provided in the fuel cell and generated by the second electrode An exhaust path opening / closing member that opens and closes an exhaust path through which the generated fluid passes according to a connection state of the connection portion.

  According to this aspect, the exhaust path through which the generated fluid generated by the second electrode passes can be opened and closed according to the connection state of the connection portion provided in the fuel cell module. Therefore, for example, in the state of the fuel cell module alone without being connected to the device, the exhaust path can be closed, and when storing or transporting the fuel cell module, for example, moisture or liquid fuel is exposed to the electrode or liquid. Evaporation from the fuel storage unit can be suppressed. In addition, when the fuel cell module is connected to a device or a connector as a power source for the device to be used, the exhaust path that has been closed until then is opened. For example, carbon dioxide as a generated fluid generated by power generation is discharged through the exhaust path. Can be released to the atmosphere.

  Yet another embodiment of the present invention is a connector. This connector is a connector that is detachably connected to a connection portion of the fuel cell module, and includes a voltage conversion portion that converts the output voltage of the fuel cell into a voltage corresponding to a load of a device that uses the fuel cell.

  According to this aspect, since the fuel cell module is connected to the device via the connector that converts the output voltage into a voltage corresponding to the load of the device, the fuel cell module does not need to have a function of converting the voltage, and the cost is low. The fuel cell module can be provided.

  A combination of the above-described elements as appropriate can also be included in the scope of the invention for which patent protection is sought by this patent application.

  ADVANTAGE OF THE INVENTION According to this invention, it can suppress that performance deteriorates in the state which is not using the fuel cell module.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings. In the following embodiments, a direct methanol fuel cell (DMFC) that is a solid polymer type will be described as an example of a fuel cell.

(Basic configuration of DMFC)
First, the basic configuration of the DMFC 10 used in the embodiment will be described. FIG. 1 is an exploded perspective view showing a basic configuration of a DMFC according to an embodiment. FIG. 2 is a cross-sectional view showing a basic configuration of the DMFC according to the embodiment.

  The DMFC 10 includes an electrolyte membrane 16, an anode electrode 12 as a first electrode provided on one surface of the electrolyte membrane, and a cathode electrode 14 as a second electrode provided on the other surface of the electrolyte membrane 16. And a housing 34 that houses the electrolyte membrane 16, the anode electrode 12, and the cathode electrode 14. The anode electrode 12 is supplied with an aqueous methanol solution or pure methanol (hereinafter referred to as “methanol fuel”) as a liquid fuel by capillary action. The cathode electrode 14 is supplied with air. The DMFC 10 generates power by an electrochemical reaction between methanol in methanol fuel and oxygen in air.

  The anode side current collector 18 and the cathode side current collector 20 are current collectors provided in each cell 22. The wiring 24 can connect a plurality of cells 22 in series by connecting the anode-side current collector 18 and the cathode-side current collector 20. A fuel storage unit 26 for storing methanol fuel to be supplied to the anode electrode 12 is provided at the bottom of the anode electrode 12. The methanol fuel filled in the fuel storage unit 26 is supplied to the anode catalyst layer 32 from the methanol fuel supply port 28 via the anode-side current collector 18 by the capillary phenomenon of the anode electrode base material 30 constituting the anode electrode 12. Is done.

  On the other hand, an air supply port 36 is provided on the surface of the housing 34 facing the cathode electrode 14, and oxygen is supplied from the air supply port 36 to the cathode catalyst layer 38 using a naturally generated air flow. Is done. Further, an exhaust port 42 to which a gas-liquid separation filter is attached is provided on the side surface of the fuel storage unit 26, and gas generated from the exhaust port 42 at the anode electrode 12, carbon dioxide in the present embodiment, is generated. It passes through the gas-liquid separation filter and is exhausted to the outside of the DMFC 10.

In the present embodiment, the anode electrode 12 has an anode catalyst layer 32 formed on an anode electrode base material 30, and the cathode electrode 14 has a cathode catalyst layer 38 formed on a cathode electrode base material 40. Is. In addition, what can be used as an electrode is not restricted to the above-mentioned anode electrode 12 and cathode electrode 14, The catalyst layer which has a catalyst function which produces | generates H ^{<+ >} from methanol and water from H ^<+> and oxygen. Any electrode may be used.

  The methanol fuel in the fuel storage unit 26 is sucked up by the capillary phenomenon of the anode electrode base material 30 from the methanol fuel supply port 28 through the anode-side current collector 18, and methanol is oxidized on the anode catalyst layer 32 ( Formula (1)). The reaction at the anode catalyst layer 32 is as follows.

Proton H ⁺ obtained by oxidation of methanol diffuses in the electrolyte membrane 16 and reaches the cathode catalyst layer 38 of the cathode electrode 14. Electricity generated at the anode electrode 12 passes through the anode-side current collector 18. As a result, the cathode-side current collector 20 on the cathode electrode 14 side is reached. On the other hand, oxygen in the air taken in from the air supply port 36 of the housing 34 reaches the cathode catalyst layer 38 of the cathode electrode 14, and reduces oxygen by receiving protons and electrons obtained from the anode electrode 12. To produce water (formula (2)). The reaction at the cathode catalyst layer 38 is as follows.

  Thus, the electricity taken out by the cell 22 can be used to directly drive the portable device by connecting to the portable device or to charge the secondary battery or the like.

  As shown in the formula (1), carbon dioxide is generated in the methanol oxidation reaction in the anode catalyst layer 32. When the generated carbon dioxide reaches a certain concentration or more, it becomes a gas (bubble) 60 and enters the porous anode-side current collector 18 and the holes of the anode electrode substrate 30. In the anode electrode base material 30, innumerable holes having an average pore diameter of several μm to several tens of μm serve as a fuel supply path to the anode catalyst layer 32. The path is blocked, and the amount of methanol supplied to the anode catalyst layer 32 decreases. Therefore, the carbon dioxide generated at the anode electrode 12 is discharged outside through a gas-liquid separation filter attached to the exhaust port 42.

  As described above, the DMFC 10 requires oxygen to generate power, and carbon dioxide is generated by power generation. Therefore, during power generation, the DMFC 10 takes in oxygen from the outside atmosphere and releases the carbon dioxide to the atmosphere. There is a need.

(Fuel cell module)
The fuel cell module according to the present embodiment includes an air supply path opening / closing member that shields the air supply port 36 provided in the DMFC 10. FIG. 3 is a perspective view showing an appearance of the fuel cell module according to the embodiment. 4 is a view of the fuel cell module shown in FIG. 3 as viewed from the A direction.

  As shown in FIG. 3, the fuel cell module 100 has a rectangular parallelepiped appearance, and electrically connects the hollow case 52, the DMFC 10 housed in the case 52, and the DMFC 10 to a connector to be described later. Open and close the air supply path between the power connection portion 54 attached to the DMFC 10 and the air supply port 36 provided in the housing 34 and the outside of the fuel cell module 100 so that oxygen supplied to the cathode electrode 14 can pass therethrough. An air supply path opening / closing member 56, an exhaust port 42 through which gas generated at the anode electrode 12 is exhausted, and an exhaust path opening / closing member 60 for opening / closing an exhaust path between the outside of the fuel cell module are provided.

  The case 52 is provided with a large opening 52 b on a surface 52 a facing the air supply path opening / closing member 56. Further, the case 52 is provided with an opening 52d at a location near the anode electrode 12 and the fuel storage unit 26 on the side surface 52c adjacent to the surface 52a. The air supply path opening / closing member 56 is disposed between the case 52 and the DMFC 10, and a plurality of communication ports 56 a corresponding to the air supply ports 36 are provided. The exhaust path opening / closing member 60 is disposed between the case 52 and the DMFC 10, and a plurality of communication ports 60 a corresponding to the exhaust ports 42 are provided.

  FIG. 5 is a B-B ′ cross-sectional view of the fuel cell module shown in FIG. 4. FIG. 6 is a C-C ′ cross-sectional view of the fuel cell module shown in FIG. 4. As shown in FIG. 5, one end of the spring 58 is attached to the inner wall of the case 52, and the other end urges the air supply path opening / closing member 56 in a direction toward the power connection portion 54 (right direction in the figure). is doing. Therefore, when the fuel cell module 100 is not used as a power source alone, the air supply port 36 of the DMFC 10 is closed by the air supply path opening / closing member 56. In other words, the air supply path between the air supply port 36 and the outside of the fuel cell module 100 is closed by the air supply path opening / closing member 56. For this reason, since the air supply port 36 is shielded from the atmosphere, it is possible to suppress intrusion of foreign matters and drying of the electrolyte membrane when the fuel cell module 100 is stored or transported.

  Further, as shown in FIG. 6, the spring 62 has one end attached to the inner wall of the case 52, and the other end attached to the exhaust path opening / closing member 60 in the direction toward the power connecting portion 54 (right direction in the figure). It is fast. Therefore, when the fuel cell module 100 is not used as a power source alone, the exhaust port 42 of the DMFC 10 is closed by the exhaust path opening / closing member 60. In other words, the exhaust path between the exhaust port 42 and the outside of the fuel cell module 100 is closed by the exhaust path opening / closing member 60. For this reason, since the anode electrode 12 is not in direct contact with the atmosphere, it is possible to suppress evaporation of moisture and ethanol fuel from the anode electrode 12 when the fuel cell module 100 is stored or transported.

(connector)
The fuel cell module 100 according to the present embodiment is connected to a device via a connector. FIG. 7 is a perspective view showing an appearance of the connector according to the embodiment. FIG. 8 is a side view of the connector shown in FIG. 7 as viewed from the D direction.

  The connector 200 incorporates a circuit unit such as a DC / DC converter as a voltage conversion unit that converts the output voltage of the DMFC 10 into a voltage corresponding to the load of the device. Thereby, it is not necessary to give the fuel cell module 100 the function of converting the voltage, and the fuel cell module 100 can be manufactured at low cost. Examples of devices to which the fuel cell module 100 according to the present embodiment supplies electric power include electronic devices such as a mobile phone, a portable terminal (PDA), a digital camera, and a notebook personal computer.

  The connector 200 is connected to a rectangular parallelepiped housing 70 containing a circuit portion, protrusions 72, 74, and 76 provided on one surface of the housing 70, and a power connection portion 54 attached to the DMFC 10, and is a fuel cell module. And a power connection part 78 for fixing 100 to the connector 200. The protrusions 72, 74, 76 and the power connection portion 78 are provided on the same surface. Then, when the power connection portion 78 is connected to the power connection portion 54 attached to the DMFC 10, the protrusions 72, 74, and 76 push a part of the fuel cell module 100, so that the air supply path opening / closing member 56 and the exhaust path opening / closing member. 60 is moved. The fuel cell module 100 is mounted on the electronic device via the connector 200, thereby supplying electric power to the electronic device and driving the electronic device and charging the power storage means provided in the electronic device.

  FIG. 9 is a schematic diagram showing a state in which the fuel cell module according to the embodiment is mounted on a portable terminal. FIG. 10 is a schematic diagram showing a state in which the fuel cell module according to the embodiment is mounted on a mobile phone.

  The fuel cell module 100 is connected via the connector 210 when attached to the portable terminal 300, and connected via the connector 220 when attached to the portable telephone 400. Thus, even when the voltage and power of the electronic devices to be used are different, the fuel cell module 100 can be shared by using a connector adapted to each electronic device. Therefore, the cost of the fuel cell module 100 can be reduced. Moreover, the user does not need to have a different fuel cell module for each electronic device by using a connector adapted to the electronic device, and can provide a user-friendly fuel cell module.

(Fuel cell module connection mechanism)
FIG. 11 is a cross-sectional view taken along line BB ′ in a state where the connector is connected to the fuel cell module shown in FIG. 12 is a cross-sectional view taken along the line CC ′ in a state where the connector is connected to the fuel cell module shown in FIG.

  As shown in FIG. 11, when the connector 200 is connected to the fuel cell module 100 in the direction of the arrow, the abutting portion 56 b of the air supply path opening / closing member 56 is brought into contact with and pressed by the protrusion 72, so that the air supply path opening / closing member 56 is Then, it moves to the left in the figure along the surface where the air supply port 36 is provided against the elastic force of the spring 58. As a result, the air supply path opening / closing member 56 moves relative to the air supply port 36, and the communication port 56a overlaps the position of the air supply port 36, so that the air supply port 36 is opened to the atmosphere. .

  In this way, when the fuel cell module 100 is connected to the connector 200 as the power source of the device to be used, the air supply port 36 that has been closed by the air supply path opening / closing member 56 is opened. Since it is opened, oxygen necessary for power generation can be supplied to the cathode electrode 14 through the air supply port 36. As a result, the air supply path is opened only when power generation by the fuel cell module 100 is necessary. Therefore, when the fuel cell module is stored or transported, it is possible to suppress entry of foreign matter and drying of the electrolyte membrane. it can. As a result, it is possible to prevent the performance from deteriorating when the fuel cell module 100 is not used. Further, the air supply port 36, that is, the air supply path can be opened at the time of use with a simple configuration without using a driving force such as a motor.

  Also, as shown in FIG. 12, when the connector 200 is connected to the fuel cell module 100 in the direction of the arrow, the contact portion 60b of the exhaust path opening / closing member 60 is pressed against and pressed against the protrusion 76, so that the exhaust path opening / closing member 60 is Then, it moves to the left in the figure along the surface where the exhaust port 42 is provided against the elastic force of the spring 62. As a result, the exhaust path opening / closing member 60 moves relative to the opening 52d and the exhaust port 42, and the communication port 60a overlaps with the positions of the opening 52d and the exhaust port 42, thereby exhausting through the communication port 60a. The mouth 42 is open to the atmosphere.

  As described above, when the fuel cell module 100 is connected to the connector 200 as the power source of the equipment to be used, the space between the exhaust port 42 and the opening 52d that has been closed by the exhaust path opening / closing member 60 until then is connected via the communication port 60a. Since the communicating exhaust path is opened, carbon dioxide generated by power generation can be released from the exhaust port 42 to the atmosphere. As a result, only when power generation by the fuel cell module 100 is necessary, the exhaust port 42 and the opening 52d are communicated to open the exhaust path. Therefore, when storing or transporting the fuel cell module, moisture or liquid fuel is used. Can be prevented from evaporating from the anode electrode or the liquid fuel reservoir. As a result, it is possible to prevent the performance from deteriorating when the fuel cell module 100 is not used. In addition, the exhaust port 42 and the opening 52d can be communicated with each other with a simple configuration without using a driving force such as a motor, and the exhaust path can be opened.

  The present invention is not limited to the above-described embodiments, and various modifications such as design changes can be added based on the knowledge of those skilled in the art. The form can also be included in the scope of the present invention.

  For example, the fuel cell module according to the above-described embodiment is configured to be connected to a device via a connector, but may be configured to be directly connected to the device.

It is a disassembled perspective view which shows the basic composition of DMFC which concerns on embodiment. It is sectional drawing which shows the basic composition of DMFC which concerns on embodiment. It is a perspective view which shows the external appearance of the fuel cell module which concerns on embodiment. It is the figure which looked at the fuel cell module shown in FIG. 3 from the A direction. It is B-B 'sectional drawing of the fuel cell module shown in FIG. It is C-C 'sectional drawing of the fuel cell module shown in FIG. It is a perspective view which shows the external appearance of the connector which concerns on embodiment. It is the side view which looked at the connector shown in FIG. 7 from the D direction. It is a schematic diagram which shows the state which mounted | wore the portable terminal with the fuel cell module which concerns on embodiment. It is a schematic diagram which shows the state which mounted | wore the mobile phone with the fuel cell module which concerns on embodiment. It is a B-B 'sectional view in the state where a connector was connected to the fuel cell module shown in FIG. It is C-C 'sectional drawing in the state which connected the connector to the fuel cell module shown in FIG.

Explanation of symbols

  10 DMFC, 12 Anode electrode, 14 Cathode electrode, 16 Electrolyte membrane, 26 Fuel storage part, 36 Air supply port, 42 Exhaust port, 52b Opening part, 52d Opening part, 56 Air supply path opening / closing member, 56a Communication port, 56b Contact portion, 60 exhaust path opening / closing member, 60a communication port, 60b contact portion, 100 fuel cell module, 200 connector.

Claims (3)

A fuel cell comprising: an electrolyte membrane; a first electrode provided on one surface of the electrolyte membrane; and a second electrode provided on the other surface of the electrolyte membrane;
A connecting portion provided in the fuel cell, and connected to a device that is electrically connected to the fuel cell and is detachably connected;
An air supply path opening / closing member provided in the fuel cell, for opening and closing an air supply path through which a reaction fluid supplied to the first electrode passes, according to a connection state of the connection portion;
A fuel cell module comprising: A fuel cell comprising: an electrolyte membrane; a first electrode provided on one surface of the electrolyte membrane; and a second electrode provided on the other surface of the electrolyte membrane;
A connecting portion provided in the fuel cell, connected to a device that is electrically connected to the fuel cell and is detachably connected;
An exhaust path opening / closing member that is provided in the fuel cell and opens and closes an exhaust path through which a product fluid generated by the second electrode passes, according to a connection state of the connection part;
A fuel cell module comprising: A connector detachably connected to the connecting portion of the fuel cell module according to claim 1 or 2,
A connector comprising: a voltage converter that converts the output voltage of the fuel cell into a voltage corresponding to a load of a device that uses the fuel cell.

Images