JP2008192526A - Activation method of fuel cell, and fuel cell system - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide an activation method of a fuel cell and to provide a fuel cell system, wherein the activation of the fuel cell into which a fuel cell power generation part is incorporated to be a device is easily performed. <P>SOLUTION: An electrolyte layer 4 is sandwiched between a fuel electrode 2, which oxidizes fuel, and an air electrode 3, which reduces at least oxygen to its elements as an active material, and the fuel electrode 2 is fueled in a state of blocking oxygen supply to the air electrode 3 of the power generation part 1 including an electrode structure including gas diffusion layers 5 and 6 and is left alone for predetermined time in an open circuit state. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a fuel cell activation method and a fuel cell system, and is particularly characterized by a configuration for easily activating a portable small fuel cell that is incorporated into a device by incorporating a fuel cell power generation unit. The present invention relates to a fuel cell activation method and a fuel cell system.

  In recent years, portable electronic devices such as mobile phones, PDAs (Personal Digital Assistants), and notebook personal computers are becoming smaller, lighter, and more functional. Along with the progress of these electronic devices, the battery serving as a driving power source is also becoming smaller, lighter, and higher in capacity.

  In such portable electronic devices, lithium ion batteries are most commonly used as a drive power source. Lithium ion batteries have a high drive voltage and a large battery capacity, and are adapted to the progress of portable electronic devices. Performance improvements have been made.

However, there is a limit to improving the performance of lithium ion batteries, and lithium ion batteries are no longer able to satisfy the demand as a driving power source for portable electronic devices whose functions are increasing in the future.
Under such circumstances, a new power generation device replacing the lithium ion battery has been developed, and a fuel cell that is expected to have a capacity that is several times higher than that of the lithium ion battery has been proposed.

  A fuel cell has a structure composed of an anode electrode (negative electrode) and a cathode electrode (positive electrode) containing a catalyst, and an electrolyte that allows ions to move between them. In this fuel cell, the anode electrode When oxygen is supplied to the cathode electrode and oxygen is supplied to the cathode electrode, an electrochemical reaction occurs at each electrode by the action of the catalyst contained in the electrode, and current can be taken out using the fuel as a supply source.

  In a fuel cell that generates power by such a mechanism, continuous power generation is possible by continuing to supply fuel and oxygen. The fuel cell is a secondary battery that is repeatedly used by charging operation by replenishing fuel and oxygen. It can be used as well.

  Such fuel cells are categorized in various ways based on the type of electrolyte and fuel. The power source for portable electronic devices can be operated at a low temperature around room temperature or can be made compact. A direct methanol fuel cell (DMFC) that supplies a methanol aqueous solution to the fuel electrode is considered suitable because it includes a solid electrolyte that is resistant to vibration and easy to mass-produce.

  Currently, many DMFCs are publicly known, but DMFCs can be classified into various types according to the method of supplying fuel to the electrode structure and the state of the fuel. Among these, natural vaporization type passive DMFCs (for example, Patent Document 1 or Patent Document 2) can supply a high-concentration methanol fuel and discharge a reaction product with a simple structure.

In addition, one of the advantages of the natural vaporization type passive DMFC is that the amount of water vapor that is evaporated at the air electrode and released outside the system during fuel cell power generation can be minimized.
That is, the water vapor in the fuel dilution type DMFC includes not only water generated at the air electrode by power generation but also a large amount derived from water for fuel dilution.

  However, in a method using a high-concentration methanol solution close to 100% concentration (for example, see Patent Document 2 described above), water necessary for power generation reaction at the fuel electrode is transported from the air electrode to the fuel electrode by natural diffusion through the electrolyte membrane. It is not necessary to add water to the fuel in order to use the generated power generation water.

  As a result, the amount of water vapor can be reduced by the amount of fuel dilution water, and since the water vapor released is only generated water from the power generation reaction, problems such as condensation outside the fuel cell are minimized. Is possible.

In general, the DMFC has a very low power generation characteristic and is unstable immediately after assembly of the fuel cell power generation unit, and several factors are assumed for this phenomenon.
For example, a fixed electrolyte that can obtain sufficient ionic conductivity in a water retention state is in a dry state at the time of assembly, and immediately after assembly, the ionic conductivity is low until the water retention state of the electrolyte is good. Become.

In addition, even a catalyst that forms a sufficient electrochemical reaction field if the surface is clean, can react sufficiently by oxidation of the catalyst surface or adhesion of oxide contamination during pasting or hot pressing in the catalyst layer formation process. The power generation performance of the fuel cell is lowered without forming a field.
Furthermore, even when the fuel cell is left unused for a long period of time, the same phenomenon occurs due to drying of the electrolyte, adhesion of contaminants in the atmosphere, etc., and the power generation performance of the fuel cell is likely to deteriorate.

  As a countermeasure to such a problem, an activation process of the fuel cell is being studied. The activation is a preliminary process for recovering the above-described material fuel cell performance degradation. .

For example, a method of promoting the impregnation of water into the electrolyte by introducing alcohol into the fuel supply passage and then washing with deionized water (see, for example, Patent Document 3), or a fuel and an inert gas on the anode and the cathode, respectively. There has been proposed a method of cleaning the catalyst surface by applying a reverse potential by connecting to an external power supply while supplying (see, for example, Patent Document 4).
JP 2000-106201 A JP 2006-040882 A JP 2004006416 A JP 2006-040598 A

  However, the activation methods that have been proposed so far are mainly the method of activation immediately after the battery is manufactured or the method of connecting a fuel supply pipe or external power to the battery. Therefore, there is a problem that it is difficult to apply to a small fuel cell system for a portable device that becomes a device.

  In addition, there are many methods that require disassembly of the system after being left for a long period of time, and a new activation method that is applicable to a device-equipped fuel cell system by a simple method is required.

  Accordingly, an object of the present invention is to easily activate a fuel cell that is built into a device incorporating a fuel cell power generation unit.

FIG. 1 is a block diagram showing the principle of the present invention, and means for solving the problems in the present invention will be described with reference to FIG.
See FIG. 1 In order to solve the above-mentioned problem, the present invention provides a fuel cell activation method in which an electrolyte layer 4 is sandwiched between a fuel electrode 2 that oxidizes fuel and an air electrode 3 that reduces at least oxygen as an active material. Supplying fuel to the fuel electrode 2 in a state where the oxygen supply to the air electrode 3 of the power generation unit 1 provided with the electrode structure including the gas diffusion layers 5 and 6 is cut off, and leaving it for a predetermined time in an open circuit state. Features.

  As described above, as a means for activating the fuel cell, a simple configuration is adopted in which fuel is supplied to the fuel electrode 2 in a state where the supply of oxygen to the air electrode 3 of the power generation unit 1 is shut off and left for a predetermined time in an open circuit state. As a result, the activation can be easily performed on the end user side.

  In this way, when the fuel is supplied while shutting off the air supply to the air electrode 3 of the fuel cell and kept in the open circuit state, the oxygen in the remaining space after the air shutoff is the fuel that has cross-leaked through the electrolyte layer 4. An oxidation reaction occurs with the fuel on the pole 2 side. At this time, contamination due to the oxidation reaction is assumed to be attached to the catalyst surface.

  While oxygen is present in the remaining space, the normal voltage of the fuel cell is confirmed as an open circuit voltage. However, when the remaining oxygen is completely consumed, the interior of the power generation unit 1 is in an oxygen-free state and fuel such as methanol is present. In this state, it is considered that the inside of the power generation unit 1 is in a reducing atmosphere, so that it is possible to remove oxide contamination adhered to the catalyst surface, and as a result, cleaning of the catalyst surface is completed.

Further, as an open circuit state when the fuel cell system is left, a state where the open circuit voltage per unit cell is 0.3 V or less may be set as a target.
That is, in an anoxic state, the normal voltage of the fuel cell cannot be confirmed as an open circuit voltage, and the potential drops and stabilizes, so that the open circuit voltage can be focused.
In this case, the target voltage may be 0.3 V, which is a voltage slightly higher than the voltage that drops and stabilizes.

Moreover, the fuel used for the fuel cell having the above-described configuration is preferably either methanol or an aqueous methanol solution, which is a fuel used in a DMFC suitable for a small fuel cell.
When the fuel is a high concentration methanol aqueous solution having a concentration of 80% or more, the fuel is vaporized and supplied to the power generation unit 1.

  In addition, it is desirable that the fuel supplied at the time of activation is supplied from an activation-dedicated cartridge, so that the fuel in the fuel cartridge for power generation is not consumed except for power generation, so that the cartridge replacement cycle can be lengthened. it can.

  In order to shut off the air when activated, the air supply port 7 of the fuel cell may be closed by an activation tray, or a closing shutter member may be provided on the fuel cell itself and closed by the closing shutter member. Also good.

  The present invention also includes a fuel electrode 2 that oxidizes fuel, an air electrode 3 that reduces at least oxygen as an active material, an electrolyte layer 4 sandwiched between the fuel electrode 2 and the air electrode 3, a gas diffusion layer 5, In the fuel cell system including the power generation unit 1 having the electrode structure including the air electrode 6, the air shut-off mechanism for supplying fuel to the fuel electrode 2 in a state where the oxygen supply to the air electrode 3 of the power generation unit 1 is shut off. 8.

  As described above, in a fuel cell system equipped with a fuel cell such as a cellular phone, an air shut-off mechanism 8 is provided for supplying fuel to the fuel electrode 2 in a state where the oxygen supply to the air electrode 3 of the power generation unit 1 is shut off. As a result, the fuel cell can be easily activated on the end user side.

  According to the present invention, it is possible to activate the fuel cell on the end user side with a simple configuration and method without requiring connection of a special fuel supply pipe or external power for the activation process of the fuel cell. .

  The present invention relates to a method for activating a fuel cell, wherein a power generation includes a fuel electrode that oxidizes fuel and an electrode structure that includes a vaporized fuel diffusion layer sandwiched between an electrolyte layer by an air electrode that reduces at least oxygen as an active material. In the state where the oxygen supply to the air electrode is shut off by closing the air supply port of the fuel cell with a closing shutter member provided on the activation tray or the fuel cell itself, either methanol or aqueous methanol solution is supplied to the fuel electrode. By supplying this fuel and leaving it in the open circuit state for a predetermined time, the remaining oxygen is completely consumed, so that the inside of the power generation unit is filled with oxygen in an oxygen-free state. As a reducing atmosphere, oxide contaminants adhering to the catalyst surface are removed, cleaned and activated.

Here, the fuel cell system according to Embodiment 1 of the present invention will be described with reference to FIGS.
See Figure 2
FIG. 2 is a conceptual cross-sectional view showing the internal structure of a fuel cell to which the present invention is applied. The fuel cell power generation unit is arranged from the air electrode side to the cathode housing 11, the air electrode current collector 12, and the air electrode gas diffusion layer 13. , An air electrode catalyst layer 14 corresponding to the positive electrode, a solid electrolyte layer 15, a fuel electrode catalyst layer 16 corresponding to the negative electrode, a fuel electrode gas diffusion layer 17, a fuel electrode current collector 18, and a vaporized fuel diffusion layer 19. A fuel tank 22 that holds the fuel vaporization layer 20 and the fuel 21 is disposed adjacent to the diffusion layer 19.

Further, the vaporized fuel diffusion layer 19 has a structure in which an end portion is exposed to the outside of the fuel cell power generation system, and the exposed portion serves as a discharge port 23 for carbon dioxide generated by an oxygen reaction of the fuel.
These fuel cell power generation units are built in a case 25 in which a gas exchange port 24 serving as an air supply port is formed, and a gas exchange space 26 is installed between the fuel cell power generation unit and the case 25.

  In this case, the air electrode current collector 12 and the fuel electrode current collector 18 are made of an alloy having high conductivity and corrosion resistance, such as SUS304 and SUS316 whose surfaces are plated with Au, respectively. It is configured in a shape of mesh, expanded metal, foam metal, etc. so that it can be introduced into the fuel electrode catalyst layer 16 and the air electrode catalyst layer 14.

  The air electrode gas diffusion layer 13 and the fuel electrode gas diffusion layer 17 are formed in a porous body so that the fuel 21 and oxygen in the air can be introduced into the fuel electrode catalyst layer 16 and the air electrode catalyst layer 14, respectively. When disposed between the catalyst layer 16 and the air electrode catalyst layer 14 and the fuel electrode current collector 18 and the air electrode current collector 12, it is necessary to have conductivity, and for example, carbon paper (manufactured by Toray) or the like is used.

The air electrode catalyst layer 14 is a mixture of a catalyst or catalyst carrier capable of generating an electrochemical reaction that generates water from protons (H ⁺ ) and oxygen (O ₂ ) and a proton conductive polymer solid electrolyte, It is applied to the air electrode gas diffusion layer 13 or the solid electrolyte layer 15.

  The solid electrolyte 15 is a polymer material having proton conductivity. For example, a perfluorosulfonic acid resin film, specifically, for example, Nafion (registered trademark) N112 (trade name, manufactured by DuPont) is used. .

Further, the fuel vaporization layer 16 built in the fuel tank 22 is a membrane that can separate the fuel 21 and the vaporized fuel diffusion layer 19, and is a porous membrane having separability due to surface tension or a non-porous material that is impregnated and impregnated. Polymeric materials are preferred.
For example, Nafion (registered trademark of DuPont), Flemion (trade name, manufactured by Asahi Glass Co., Ltd.), and Aciplex (trade name, manufactured by Asahi Kasei Co., Ltd.), which are perfluoro resin films, can be used because they are insoluble in a high concentration aqueous methanol solution.

See Figure 3
FIG. 3 is a schematic perspective view of the fuel cell system according to the first embodiment of the present invention. Here, a portable electronic device such as a mobile phone will be described as an example.
The housing 31 of the electronic device 30 on which the fuel cell shown in FIG. 2 is mounted has an opening 32 so that the gas exchange port 24 of the fuel cell is exposed, and an openable cover 33 for inserting and removing the fuel cartridge. Is provided.
In this case, the fuel tank 22 is shown as a replaceable fuel tank type in which fuel is replaced by replacing the fuel tank 22 as a cartridge.

See Figure 4
FIG. 4 is an apparatus configuration diagram when the fuel cell system according to the first embodiment of the present invention is activated. The activation process is performed using the aging cartridge 34 and the aging tray 35.
The aging cartridge 34 in this case is, for example, a disposable cartridge, and the aging cartridge 34 is filled with fuel required for one activation process, that is, aging.

  Further, the aging tray 35 is made of, for example, plastic, and is configured to be tightly fitted to the lower portion of the casing 31 of the electronic device 30. The opening 32 is sealed by the inner surface of the aging tray 35. The

  The amount of fuel and the aging time mounted on the aging cartridge 34 are set in advance based on the amount of oxygen remaining in the remaining space when the gas exchange port 24 is sealed and the consumption time of the oxygen.

  In this way, the aging cartridge 34 is mounted on the electronic device 30 and the aging tray 35 is left for a predetermined time, and then the electronic device 30 is removed from the aging tray 35 and the aging cartridge 34 is removed. The activation process ends.

Next, the effect of the activation process in the first embodiment of the present invention will be described with reference to FIGS.
Here, the following materials were used in the respective components of the fuel cell described above.
-Fuel electrode catalyst: Pt-Ru alloy supported catalyst TEC61E54 (Product model number, Tanaka Kikinzoku Co., Ltd.)
-Air electrode catalyst: Pt-supported catalyst TEC10E50E (Product model number, Tanaka Kikinzoku Co., Ltd.)
Solid electrolyte membrane: Nafion (registered trademark) N112 (product model number manufactured by DuPont)
・ Catalyst mixing / Supported solid electrolyte: Nafion (registered trademark) 20042 (Product number manufactured by DuPont)
・ Hydrophilic porous membrane: Durapore membrane filter HVLP14250 (Nippon Millipore product name)

See Figure 5
FIG. 5 is an explanatory diagram of the voltage drop of the unit cell during the activation process in Example 1 of the present invention, and the normal voltage of the fuel cell is confirmed as an open circuit voltage while oxygen is present in the remaining space. However, when this residual oxygen is completely consumed, power generation does not occur, the normal voltage of the fuel cell cannot be confirmed as an open circuit voltage, and the potential drops greatly and stabilizes.

  Therefore, it is only necessary to determine that the activation process is performed by paying attention to the open circuit voltage, and the target voltage for that purpose is 0.3 V, which is slightly higher than the voltage that drops and stabilizes. The time required for the activation process, for example, 50 minutes may be experimentally confirmed in advance.

  In this activation process, when the remaining oxygen is completely consumed, the inside of the power generation unit is oxygen-free and is filled with methanol contained in the fuel 21. In this state, the inside of the power generation unit is considered to be a reducing atmosphere. Therefore, it is possible to reduce and remove oxide contaminants adhering to the surface of the fuel electrode catalyst layer 16, and as a result, cleaning of the catalyst surface is completed.

See FIG.
FIG. 6 is a flowchart of the activation process in the first embodiment of the present invention. After assembling the fuel cell system, generating power and measuring the output due to discharge, the fuel cartridge is replaced with the aging cartridge 33. As described above, aging is performed for a predetermined time, and then the aging cartridge 33 is replaced with a fuel cartridge, and then power generation is performed to measure the output due to discharge.

Here, in order to compare and evaluate the effects of the activation process of the first embodiment of the present invention, the evaluation fuel cell system having the same structure as that of the first embodiment performs power generation without performing the activation process, Both fuel cell outputs before and after were compared.
In the comparative example, the output due to the two discharges was measured simply by replacing the fuel cartridge without performing the activation process.

See FIG.
FIG. 7 is a comparison diagram of the output before and after the activation process. In the first embodiment of the present invention, if the initial output immediately after assembly is 100, the output after the activation process is 162 and the output is 62. % Increase was confirmed.
On the other hand, in the comparative example, there was no change in the output due to the two discharges.

Immediately after assembly of the fuel cell system, the ion conductivity is low until the water retention state of the solid electrolyte layer becomes good, or a sufficient reaction field is formed by oxidation of the catalyst surface or adhesion of oxide contamination. If the power generation performance of the fuel cell could not be fully demonstrated due to failure, the water retention state of the solid electrolyte layer became good during the activation process, and oxidation and oxide contamination on the catalyst surface were reduced due to the reducing action. It is thought that it was removed.
The first discharge is performed to confirm the effect of the present invention, and is not a necessary condition for the actual activation process.

Next, a fuel cell system according to Example 2 of the present invention will be described with reference to FIG.
See FIG.
FIG. 8 is a schematic perspective view of the fuel cell system according to the second embodiment of the present invention. The basic configuration is the same as in the first embodiment, and the housing of the electronic device 40 in which the fuel cell shown in FIG. 2 is mounted. The body 41 is provided with an opening 42 so that the gas exchange port 24 of the fuel cell is exposed, and a sliding shutter 43 and a shutter opening / closing button 44 are provided to shield the opening 42.
The housing 41 is provided with an openable / closable cover 45 for inserting and removing the fuel cartridge.

  In the activation process in the second embodiment, an aging cartridge 46 having a shutter opening / closing projection 47 for operating the shutter opening / closing button 44 is mounted, the opening 42 is sealed by the shutter 43, and then left for a predetermined time. Then, the activation process is performed.

When the aging cartridge 46 is mounted, the shutter opening / closing projection 47 operates the shutter opening / closing button 44 so that the shutter 43 automatically slides to close the opening 42. Therefore, the activation process is started only by mounting the cartridge.
Since the fuel cartridge is not provided with the shutter opening / closing projection 47, the shutter 43 does not slide even when the fuel cartridge is mounted during normal power generation. It is captured.

  Then, after leaving for a predetermined time, the aging cartridge 46 is taken out to complete the activation process. At this time, the shutter opening / closing button 44 is released from the pressing of the shutter opening / closing projection 47, so that the shutter 43 is automatically operated. Thus, the opening 42 is opened by sliding in the opposite direction.

  In the second embodiment of the present invention, since an aging tray is not required, an activation process can be performed at any time without carrying the aging tray even during a long-term business trip, so that a high output can always be obtained. .

  The embodiments of the present invention have been described above. However, the present invention is not limited to the configurations, conditions, and numerical values shown in the embodiments, and various modifications are possible. For example, in the above embodiments, The aging cartridge used in the activation process is a cartridge filled with a small amount of fuel necessary for one activation process, but an aging cartridge filled with fuel as well as the fuel cartridge may be used. In that case, it is desirable to have a function of displaying the remaining amount of fuel or the number of activation processes.

Further, in the case of the first embodiment, the activation process may be performed using the fuel cartridge itself instead of the aging cartridge. In this case, the aging cartridge is not carried at any time. Since the activation process becomes possible, a high output can always be obtained.
However, the service life of the fuel cartridge is shortened.

In each of the above-described embodiments, the fuel supply type is a high-concentration methanol aqueous solution having a concentration of 80% or more or 100% methanol as the fuel, but a low-concentration methanol aqueous solution having a concentration of 80% or less is used. It is good also as a liquid direct supply type.
In this case, the vaporized fuel diffusion layer is unnecessary.

Here, referring to FIG. 1 again, the detailed features of the present invention will be described again.
Again see Figure 1
(Additional remark 1) The said electric power generation part 1 provided with the electrode structure which pinched | interposed the electrolyte layer 4 with the fuel electrode 2 which oxidizes a fuel, and the air electrode 3 which reduces at least oxygen as an active material, and was provided with the gas diffusion layers 5 and 6 A fuel cell activation method, characterized in that fuel is supplied to the fuel electrode 2 in a state where the oxygen supply to the air electrode 3 is cut off, and left for a predetermined time in an open circuit state.
(Supplementary note 2) The fuel cell activation method according to supplementary note 1, wherein the open circuit state when the fuel cell system is left is a state where an open circuit voltage per unit cell is 0.3 V or less.
(Additional remark 3) The said fuel is either methanol or methanol aqueous solution, The activation method of the fuel cell of Additional remark 1 or 2 characterized by the above-mentioned.
(Supplementary note 4) The fuel cell activation according to Supplementary note 1 or 2, wherein the fuel is a high-concentration methanol aqueous solution having a concentration of 80% or more, and the fuel is vaporized and supplied to the power generation unit 1. Method.
(Supplementary note 5) The fuel cell activation method according to any one of supplementary notes 1 to 4, wherein the fuel supplied at the time of activation is supplied from an activation-dedicated cartridge.
(Appendix 6) The fuel cell activation method according to any one of appendices 1 to 5, wherein the air supply port 7 of the fuel cell is closed by an activation-dedicated tray during the activation.
(Appendix 7) The fuel cell activity according to any one of appendices 1 to 5, wherein the air supply port 7 of the fuel cell is closed by a closing shutter member provided in the fuel cell at the time of the activation. Method.
(Supplementary Note 8) A fuel electrode 2 that oxidizes fuel, an air electrode 3 that reduces at least oxygen as an active material, an electrolyte layer 4 sandwiched between the fuel electrode 2 and the air electrode 3, and gas diffusion layers 5 and 6 A fuel cell system including a power generation unit 1 having an electrode structure including: air for supplying fuel to the fuel electrode 2 in a state where oxygen supply to the air electrode 3 of the power generation unit 1 is shut off A fuel cell system having a shut-off mechanism 8.
(Supplementary Note 9) The fuel cell system, wherein the air shut-off mechanism 8 is an activation-specific tray that closes the air supply port 7 of the fuel cell.
(Additional remark 10) The said air interruption | blocking mechanism 8 is a shutter member for closure provided in the said fuel cell which closes the air supply port 7 of the said fuel cell, The fuel cell system characterized by the above-mentioned.

  As a utilization example of the present invention, a fuel cell mounted on a cellular phone is typical, but it is also used as a power source for other portable electronic devices such as a PAD or a notebook personal computer, It is not limited to the power source of portable electronic devices, but is also used as a power source for desktop personal computers and other relatively large electronic devices.

It is explanatory drawing of the fundamental structure of this invention. 1 is a conceptual cross-sectional view showing an internal structure of a fuel cell to which the present invention is applied. 1 is a schematic perspective view of a fuel cell system according to Example 1 of the present invention. It is an apparatus block diagram in the case of activating the fuel cell system of Example 1 of the present invention. It is explanatory drawing of the voltage drop of the single cell in the activation process in Example 1 of this invention. It is a flowchart of the activation process in Example 1 of this invention. It is a comparison figure of the output before and after an activation process. It is a schematic perspective view of the fuel cell system of Example 2 of the present invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Power generation part 2 Fuel electrode 3 Air electrode 4 Electrolyte layer 5 Gas diffusion layer 6 Gas diffusion layer 7 Air supply port 8 Air shutoff mechanism 11 Cathode housing 12 Air electrode current collector 13 Air electrode gas diffusion layer 14 Air electrode catalyst layer 15 Solid Electrolyte layer 16 Fuel electrode catalyst layer 17 Fuel electrode gas diffusion layer 18 Fuel electrode current collector 19 Vaporized fuel diffusion layer 20 Fuel vaporization layer 21 Fuel 22 Fuel tank 23 Discharge port 24 Gas exchange port 25 Case 26 Gas exchange space 30 Electronic device 31 Housing 32 Opening 33 Cover 34 Aging cartridge 35 Aging tray 40 Electronic device 41 Housing 42 Opening 43 Shutter 44 Shutter opening / closing button 45 Cover 46 Aging cartridge 47 Shutter opening / closing protrusion

Claims (5)

In a state in which the supply of oxygen to the air electrode of the power generation unit including the electrode structure including the gas diffusion layer sandwiched between the electrolyte layer by the fuel electrode that oxidizes the fuel and the air electrode that reduces at least oxygen as an active material is cut off A fuel cell activation method, wherein fuel is supplied to the fuel electrode and left in an open circuit state for a predetermined time. 2. The fuel cell activation method according to claim 1, wherein the open circuit state when the fuel cell system is left is a state in which an open circuit voltage per unit cell is 0.3 V or less. 3. The fuel cell activation method according to claim 1, wherein the fuel is either methanol or an aqueous methanol solution. The method for activating a fuel cell according to claim 1, wherein the fuel is a high-concentration methanol aqueous solution having a concentration of 80% or more, and the fuel is vaporized and supplied to the power generation unit. A power generation unit having an electrode structure including a fuel electrode for oxidizing fuel, an air electrode for reducing at least oxygen as an active material, an electrolyte layer sandwiched between the fuel electrode and the air electrode, and a gas diffusion layer A built-in fuel cell system, comprising an air shut-off mechanism for supplying fuel to the fuel electrode in a state where oxygen supply to the air electrode of the power generation unit is shut off.

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