JP5526226B2 - Method for activating solid polymer fuel cell - Google Patents

Description

  The present invention relates to a method for activating a polymer electrolyte fuel cell.

  A solid polymer fuel cell is formed by sandwiching an electrode membrane structure (MEA) formed by placing a solid polymer membrane between an anode and a cathode between a pair of separators. Each of the anode and cathode is formed of a catalyst layer that performs an oxidation / reduction reaction in contact with the solid polymer film and a gas diffusion layer in contact with the catalyst layer. When the fuel cell supplies a reaction gas containing hydrogen to the anode electrode side and an oxidant gas (air) containing oxygen to the cathode electrode side, the fuel cell generates electric power by an electrochemical reaction. The fuel cell stack is configured by stacking a plurality of such fuel cells, and is mounted as a power source of a vehicle, for example.

  The power generation performance immediately after the assembly of the above polymer electrolyte fuel cell or fuel cell stack (hereinafter referred to simply as “fuel cell” unless it is necessary to distinguish between the cell and the stack) is low. For this reason, after the fuel cell is assembled, various activation processes (aging) are performed in order to improve the power generation performance. In recent years, many types of activation methods have been proposed.

  Patent Document 1 discloses an activity of a fuel cell that improves the power generation performance of the fuel cell immediately after assembly by applying a voltage that periodically varies with a predetermined width between the anode and the cathode of the fuel cell. The method of conversion is shown.

  In Patent Document 2, a so-called hydrogen pump operation in which a voltage is applied between a cathode electrode and an anode electrode by an external power supply while supplying a reaction gas only to the anode electrode without supplying gas to the cathode electrode is performed. A technique for activating a fuel cell has been proposed.

Patent Document 3 proposes a technique of activation by supplying a reaction gas to the anode electrode and supplying an oxidant gas to the cathode electrode and actually generating power in the fuel cell. More specifically, Patent Document 3 shows that it can be efficiently activated by repeating the process of increasing / decreasing the output current of the fuel cell.
JP 2008-204799 A JP 2009-104918 A JP 2005-251396 A

  As described above, various types of methods for activating solid polymer fuel cells have been proposed in recent years. However, with the conventional activation method, the power generation performance of the fuel cell reaches a predetermined target. Therefore, it takes a long time to activate, and there has been a demand for efficient activation in a shorter time.

  An object of this invention is to provide the activation method of the polymer electrolyte fuel cell which can be activated efficiently in a short time.

In order to achieve the above object, the present invention provides a method for activating a solid polymer fuel cell comprising an anode and a cathode, and a solid polymer membrane disposed between the anode and the cathode (first method) The activation method of the embodiment is provided. In the activation method, oxygen is not supplied to the cathode electrode, but hydrogen is supplied to the anode electrode, and an external power source is used to make the cathode electrode positive and provide a predetermined width between the cathode electrode and the anode electrode. The step of applying a voltage that fluctuates within the range (for example, CV operation described later) is defined as the first step, and in a state where hydrogen is supplied to the anode electrode without supplying oxygen to the cathode electrode, By flowing a current from the cathode electrode to the anode electrode, the hydrogen ions generated at the anode electrode are moved to the cathode electrode side through the solid polymer film, and electrons are received at the cathode electrode to become hydrogen again. The process is defined as a second process (for example, a hydrogen pump operation described later), and the combination of the first process and the second process is repeated twice or more.

According to the present invention, with respect to the assembled polymer electrolyte fuel cell, in a state where oxygen is not supplied to the cathode electrode and hydrogen is supplied to the anode electrode, A first step of applying a voltage that fluctuates within a predetermined width between the anode and the anode, and a current from the cathode to the anode by an external power source in a state where oxygen is not supplied to the cathode and hydrogen is supplied to the anode . Repeat the combination with the second step of flowing 2 times or more. Here, the combination of the first step and the second step means that the second step is executed after the first step is executed, or the first step is executed after the second step is executed. Means.
As a result, for example, when only the first step is performed, only the second step is performed, and when the second step is performed after the first step, the conventional activation method is compared. Thus, the fuel cell can be activated more efficiently while shortening the activation time.

  In order to achieve the above object, the present invention provides a method for activating a polymer electrolyte fuel cell (third embodiment) comprising an anode electrode and a cathode electrode and a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode. A method of activating forms). In the activation method, oxygen is not supplied to the cathode electrode, but hydrogen is supplied to the anode electrode, and an external power source is used to make the cathode electrode positive and provide a predetermined width between the cathode electrode and the anode electrode. A step of applying a voltage that fluctuates within the range (for example, CV operation to be described later) is defined as a first step, and hydrogen and oxygen are supplied to the anode electrode and the cathode electrode, respectively, and power is generated by the fuel cell (for example, The power generation operation described later is defined as a third step, and the combination of the first step and the third step is repeated twice or more.

According to the present invention, with respect to the assembled polymer electrolyte fuel cell, in a state where oxygen is not supplied to the cathode electrode and hydrogen is supplied to the anode electrode, A combination of a first step of applying a voltage that fluctuates within a predetermined width between the anode and the anode and a second step of supplying hydrogen and oxygen to the anode and the cathode, respectively, and generating power in the fuel cell, are performed twice. Repeat above. Here, the combination of the first step and the third step means that the third step is executed after the first step is executed, or the first step is executed after the third step is executed. Means.
Thereby, for example, when only the first step is performed, when only the third step is performed, and when the third step is performed after the first step, the conventional activation method is compared. Thus, the fuel cell can be activated more efficiently while shortening the activation time.

It is a figure which shows typically the structure of the activation apparatus for performing the activation method of the polymer electrolyte fuel cell which concerns on 1st Embodiment of this invention. It is a flowchart which shows the procedure of the activation method which concerns on the said embodiment. It is a figure which shows typically the structure of the activation apparatus in CV driving | operation. It is a figure which shows the change of the voltage between a cathode pole and an anode pole at the time of performing a hydrogen pump driving | operation after performing a CV driving | operation, and the change of the current density of the electric current which flows from a cathode pole to an anode pole. It is a figure which shows typically the structure of the activation apparatus in a hydrogen pump driving | operation. It is a figure which shows the result of the evaluation test of Experiment 1. It is a figure which shows the result of the evaluation test of Experiment 2. It is a figure which shows the result of the evaluation test of Experiment 3. It is a figure which shows typically the structure of the activation apparatus for performing the activation method of the polymer electrolyte fuel cell which concerns on the 1st reference form of this invention. It is a flowchart which shows the procedure of the activation method which concerns on the said reference form . It is a figure which shows typically the structure of the activation apparatus in a hydrogen pump driving | operation. It is a figure which shows the change of the current density of the electric current which flows from a cathode pole to an anode pole at the time of performing a power generation operation after performing a hydrogen pump operation. It is a figure which shows typically the structure of the activation apparatus in an electric power generation driving | operation. It is a figure which shows the evaluation test of Experiment 4. It is a figure which shows the evaluation test of Experiment 5. FIG. It is a figure which shows typically the structure of the activation apparatus for performing the activation method of the polymer electrolyte fuel cell which concerns on 3rd Embodiment of this invention. It is a flowchart which shows the procedure of the activation method which concerns on the said embodiment. It is a figure which shows typically the structure of the activation apparatus in CV driving | operation. It is a figure which shows the change of the voltage between a cathode pole and an anode pole in the case of performing CV driving | operation. It is a figure which shows typically the structure of the activation apparatus in an electric power generation driving | operation. It is a figure which shows the change of the current density of the electric current which flows from a cathode pole to an anode pole at the time of performing a power generation operation. It is a figure which shows the evaluation test of Experiment 6. FIG. It is a figure which shows the evaluation test of Experiment 7. FIG. It is a figure which shows typically the structure of the activation apparatus for performing the activation method of the polymer electrolyte fuel cell which concerns on the 2nd reference form of this invention. It is a flowchart which shows the procedure of the activation method which concerns on the said reference form. It is a figure which shows typically the structure of the activation apparatus in a hydrogen pump driving | operation. It is a figure which shows typically the structure of the activation apparatus in an electric power generation driving | operation. It is a time chart which shows the change of stack voltage when supplying oxidant gas to a cathode channel while performing hydrogen pump operation. It is a figure which shows the result of the evaluation test of Experiment 8. It is a figure which shows typically the structure of the activation apparatus for performing the activation method of the polymer electrolyte fuel cell which concerns on the 3rd reference form of this invention. It is a flowchart which shows the procedure of the activation method which concerns on the said reference form. It is a figure which shows the change of the electric current of an electronic load apparatus and a stack voltage during power generation operation and hydrogen pump operation.

1, 1A, 1B, 1C, 1D ... Activator 21 ... Cathode side gas supply device 31 ... Anode side gas supply device 4 ... Stabilized power supply FC ... Fuel cell

[First Embodiment]
Hereinafter, a first embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is a diagram schematically showing the configuration of an activation device 1 for executing the method for activating a polymer electrolyte fuel cell FC according to the present embodiment.

  The fuel cell FC is a fuel cell stack that is constructed by assembling a single fuel cell or a plurality of fuel cells after being assembled. More specifically, the fuel cell included in the fuel cell FC includes, for example, an electrode membrane structure (MEA) formed by placing a solid polymer membrane between an anode electrode and a cathode electrode with a pair of separators. It is formed by pinching. The anode electrode and the cathode electrode are each formed of a catalyst layer that is in contact with the solid polymer film and performs an oxidation / reduction reaction, and a gas diffusion layer that is in contact with the catalyst layer.

  The activation device 1 includes a cathode-side gas supply device 21 that supplies gas to a cathode flow channel that communicates with the cathode electrode of the fuel cell FC, and an anode side that supplies gas to an anode flow channel that communicates with the anode electrode of the fuel cell FC. A gas supply device 31 and a humidifier (not shown) that humidifies the gas supplied from the cathode side gas supply device 21 and the anode side gas supply device 31 are provided. In addition, the activation device 1 includes a stabilized power source 4 that applies a voltage between the cathode and anode of the fuel cell FC.

The cathode-side gas supply device 21 supplies any one of nitrogen gas containing a large amount of nitrogen, oxidant gas containing a large amount of oxygen (air), and a reaction gas containing a large amount of hydrogen to the cathode flow path of the fuel cell FC.
The anode-side gas supply device 31 supplies either nitrogen gas or reaction gas to the anode flow path of the fuel cell FC.

  The gas supplied to the cathode flow path by the cathode side gas supply device 21 via the cathode side introduction tube 22 is discharged outside the device via the cathode side discharge tube 23. The cathode side introduction pipe 22 is provided with a shut-off valve (not shown) that shuts off the gas supply from the cathode side gas supply device 21. The gas supplied to the anode flow path by the anode side gas supply device 31 via the anode side introduction pipe 32 is discharged outside the device via the anode side discharge pipe 33. The anode side exhaust pipe 33 is provided with a shut-off valve (not shown) that shuts off off-gas discharge.

Hereinafter, a procedure for activating the fuel cell FC will be described with reference to FIG.
FIG. 2 is a flowchart showing the procedure of the activation method.
In step S1, water is replenished to the fuel cell, and the process proceeds to step S2. More specifically, water is supplied to the MEA of the fuel cell by supplying nitrogen gas humidified by a humidifier to the anode channel and the cathode channel.

  In step S2, the gas in the anode channel and the cathode channel of the fuel cell is replaced, and the process proceeds to step S3. As will be described in detail later, the gas supplied to the fuel cell in the CV operation in the next step S3 is different from the gas supplied to the fuel cell for replenishing the water in the previous step S2. Therefore, in this step S2, in order to replace the gas remaining in the anode flow path and the cathode flow path of the fuel cell with the gas supplied in the next step S3, the reaction gas is supplied to the anode flow path and the cathode flow path is supplied. Supplies nitrogen gas.

  In step S3, a CV operation as a first process described later is performed for a predetermined time, and then the process proceeds to step S4. In step S4, a hydrogen pump operation as a second process described later is performed for a predetermined time, and then the process proceeds to step S5. In step S5, it is determined whether or not this combination has been repeatedly executed a predetermined number of times or more as one set in which the hydrogen pump operation is executed in step S4 after the CV operation is executed in step S3. If this determination is NO, the process moves to step S3, and a combination of CV operation and hydrogen pump operation is executed again. On the other hand, if this determination is YES, the fuel cell activation process is terminated. Here, the set number of times of step S5, that is, the number of times of repeatedly performing the combination of the CV operation and the hydrogen pump operation is the time for performing the CV operation per time, the time for performing the hydrogen pump operation per time, and the activation process. Is set to two or more according to the improvement range of the performance of the fuel cell required by the above.

  Hereinafter, the CV operation in step S3 and the hydrogen pump operation in step S4 will be described in detail with reference to FIGS.

FIG. 3 is a diagram schematically showing the configuration of the activation device in the CV operation.
FIG. 4 shows changes in the voltage between the cathode and anode when the hydrogen pump operation is performed after the CV operation is performed (FIG. 4A), and the current flowing from the cathode to the anode. It is a figure which shows the change ((b) of FIG. 4) of a density. The current density in the present invention refers to a current flowing per unit reaction area (1 [cm ² ]) of the MEA of the fuel cell.

  In the CV operation, a reaction gas containing a large amount of hydrogen is supplied to the anode flow channel, and at the same time, a nitrogen gas containing a large amount of nitrogen is supplied to the cathode flow channel without supplying an oxidant gas containing a large amount of oxygen. At this time, the shutoff valves provided in the anode side discharge pipe 33 and the cathode side introduction pipe 22 are opened, and the anode side gas supply device 31 and the cathode side gas are provided in the anode flow path and the cathode flow path of the fuel cell FC. Fresh air supplied from the supply device 21 is distributed.

  Further, in the CV operation, the fuel cell FC is connected to the stabilized power source 4 and the gas is supplied to the fuel cell FC as described above. A voltage that periodically fluctuates within a predetermined voltage width is applied between them (see FIG. 4). Here, the minimum value of the voltage width is set to a predetermined value of 0 [V] or more (for example, 0 [V]), and the maximum value is set to a predetermined value (for example, 1 [V]) larger than the minimum value. Further, the voltage waveform is preferably a sine wave as shown in FIG. 4 in order to prevent the current from fluctuating rapidly when the voltage is turned back, but is not limited to this and is a sawtooth wave or a rectangular wave. Also good.

FIG. 5 is a diagram schematically showing the configuration of the activation device in the hydrogen pump operation.
In the hydrogen pump operation, the shutoff valve provided in the cathode side introduction pipe 22 is closed and no gas is supplied to the cathode flow path, and the shutoff valve provided in the anode side discharge pipe 33 is closed to the anode flow path. A reaction gas containing a large amount of hydrogen is supplied.
Further, in the hydrogen pump operation, the fuel cell FC is connected to the stabilization power source 4 and the reaction gas is supplied to the anode electrode of the fuel cell FC as described above. By applying a voltage between the cathode electrode and the anode electrode , a predetermined amount of current flows from the cathode electrode to the anode electrode (see FIG. 4). At this time, the voltage applied by the stabilized power supply 4 is adjusted so that the current flowing from the cathode electrode to the anode electrode becomes a preset value according to the reaction area of the MEA of the fuel cell FC.

As described above, when a current is supplied from the cathode electrode to the anode electrode while supplying the gas, hydrogen ions are generated by the catalytic reaction of hydrogen on the anode electrode side. This hydrogen ion moves to the cathode electrode side through the MEA, receives hydrogen on the cathode electrode side, becomes hydrogen again, and is discharged from the cathode side discharge pipe 23.

  Hereinafter, three experimental results performed to verify the effects of the fuel cell activation method according to the present embodiment will be described.

[Experiment 1]
In Experiment 1, an experiment was performed to compare the effects of the activation method of the present embodiment and the conventional activation method. More specifically, the fuel cell activated by the activation method of the present embodiment is referred to as Example 1, the fuel cell activated by the conventional activation method is referred to as Comparative Examples 1 to 3, and these Example 1 And the evaluation test was done about Comparative Examples 1-3.

<Example 1>
A fuel cell activated by the activation method of the present embodiment is referred to as Example 1. More specifically, a fuel cell activated by the following procedure is referred to as Example 1.
That is, the fuel cell of Example 1 first replenishes the fuel cell with water (see step S1 above), replaces the gas in the fuel cell (see step S2 above), and then performs CV operation (see step S3 above). And the hydrogen pump operation (see step S4 above) was repeated a predetermined number of times.
More specifically, in hydration of the fuel cell in step S1, nitrogen gas having a temperature of about 70 ° C. and a relative humidity of about 100% was supplied to the anode channel and the cathode channel of the fuel cell for 30 minutes. Here, the flow rate of nitrogen gas was adjusted so that the flow rate per unit reaction area of MEA was 4 [ml / min].
In the replacement of the fuel cell gas in step S2, the reaction gas was supplied to the anode channel and the nitrogen gas was supplied to the cathode channel over 3 minutes. Here, the flow rates of the reaction gas and the nitrogen gas were adjusted so that the flow rate per unit reaction area of MEA was 8 [ml / min].
In the CV operation in step S3, the gas is supplied at the same flow rate as in step S2 described above, and the minimum voltage 0 [V], the maximum voltage 1 [V], and a sinusoidal voltage of 6 cycles for 5 cycles (1 cycle) For 30 minutes).
In the hydrogen pump operation of step S4, the shutoff valves of the cathode side introduction pipe and the anode side discharge pipe are closed, and the reaction gas is supplied to the anode flow path. Here, the flow rate of the reaction gas was the same as the flow rate in step S2. In the hydrogen pump operation, the anode electrode is connected to the positive electrode of the stabilized power source, the cathode electrode is connected to the negative electrode of the stabilized power source, and the current density is supplied from the cathode electrode to the anode electrode while supplying the reaction gas as described above. Continued to pass a current of 1 [A / cm ² ] for 10 minutes.
Further, the number of repetitions of step S5 was set to 4 times, and the above-described CV operation and hydrogen pump operation were performed for a total of 160 minutes.
Hereinafter, the time obtained by subtracting the time required for the above-described hydration and gas replacement from the time required for activation is referred to as the total aging time. Therefore, the total aging time of the fuel battery cell of Example 1 is 160 minutes.

<Comparative Example 1>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 1. The fuel cell of Comparative Example 1 is different from the fuel cell of Example 1 described above in that it is activated by performing only the CV operation without performing the hydrogen pump operation and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Example 1. Next, CV operation was performed for 240 minutes (40 cycles) under the same settings as in Example 1. Therefore, the total aging time of the fuel cell of Comparative Example 1 is 240 minutes.

<Comparative example 2>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 2. The fuel cell of Comparative Example 2 is different from the fuel cell of Example 1 described above in that it is activated by performing only the hydrogen pump operation without performing the CV operation, and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Example 1. Next, the hydrogen pump operation was performed for 240 minutes under the same settings as in Example 1. Therefore, the total aging time of the fuel cell of Comparative Example 2 is 240 minutes.

<Comparative Example 3>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 3. The fuel cell of Comparative Example 3 differs from the fuel cell of Example 1 described above in that neither the CV operation nor the hydrogen pump operation was performed, and the total aging time.
More specifically, the fuel cell was replenished with water and replaced with gas by the same procedure as in Example 1. Therefore, the total aging time of the fuel cell of Comparative Example 3 is 0 minute.

<Evaluation test of Experiment 1>
In the evaluation test of Experiment 1, power was actually generated in the fuel cells of Example 1 and Comparative Examples 1 to 3 as described above, and the output voltage was measured. At this time, the output voltage when the power was generated so that the current density of the output current of the fuel battery cell was 1 [A / cm ² ] was measured.

FIG. 6 is a diagram showing the results of the evaluation test of Experiment 1. FIG. 6 shows a relative value where the measured value of the output voltage of the fuel cell of Comparative Example 3 is 1.
As shown in FIG. 6, the fuel cell of Example 1 has a higher output voltage than the fuel cells of Comparative Examples 1 and 2, although the total aging time is shorter. Therefore, it has been verified that activation by the activation method of the present embodiment enables efficient activation in a shorter time than the conventional activation method.

[Experiment 2]
In Experiment 2, in the activation method of the present embodiment, an experiment was conducted to verify the effect of repeatedly combining the CV operation and the hydrogen pump operation. More specifically, the fuel cells activated by the activation method of the present embodiment are designated as Examples 2 to 5, the fuel cells activated by the conventional activation method are designated as Comparative Example 4, and these Example 2 Evaluation tests were conducted on -5 and Comparative Example 4.

  In addition, since this experiment 2 is an experiment for verifying the effect of repeatedly performing the combination of the CV operation and the hydrogen pump operation, the fuel cells of Examples 2 to 5 and Comparative Example 4 are respectively An activated product was prepared by changing the number of repetitions of the combination of CV operation and hydrogen pump operation while keeping the total aging time constant. In addition, the setting of the waveform of the voltage applied to the fuel cell during the CV operation of Examples 2 to 5 and Comparative Example 4 and the current supplied to the fuel cell during the hydrogen pump operation are the same as in Example 1 described above. Is omitted.

<Example 2>
A fuel cell activated by the activation method of this embodiment is referred to as Example 2.
More specifically, the time for performing one CV operation is 60 minutes (10 cycles), the time for performing one hydrogen pump operation is 60 minutes, and the combination of CV operation and hydrogen pump operation is repeated. The number of times was 2, and the CV operation and the hydrogen pump operation were performed for a total of 240 minutes.

<Example 3>
A fuel cell activated by the activation method of the present embodiment is referred to as Example 3.
More specifically, the time for performing CV operation per time is 42 minutes (7 cycles), the time for performing hydrogen pump operation per time is 38 minutes, and the combination of CV operation and hydrogen pump operation is repeated. The number of times was 3, and the CV operation and the hydrogen pump operation were performed for a total of 240 minutes.

<Example 4>
A fuel cell activated by the activation method of this embodiment is referred to as Example 4.
More specifically, the time for performing CV operation per time is 24 minutes (4 cycles), the time for performing hydrogen pump operation per time is 24 minutes, and the combination of CV operation and hydrogen pump operation is repeated. The number of times was 5, and the CV operation and the hydrogen pump operation were performed for a total of 240 minutes.

<Example 5>
A fuel cell activated by the activation method of the present embodiment is referred to as Example 5.
More specifically, the time for performing CV operation per time is 12 minutes (2 cycles), the time for performing hydrogen pump operation per time is 12 minutes, and the combination of CV operation and hydrogen pump operation is repeated. The number of times was 10, and the CV operation and the hydrogen pump operation were performed for a total of 240 minutes.

<Comparative Example 4>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 4.
More specifically, after the CV operation was performed for 120 minutes (20 cycles), the hydrogen pump operation was performed for 120 minutes, and the CV operation and the hydrogen pump operation were performed for a total of 240 minutes.

<Evaluation test of Experiment 2>
In the evaluation test of Experiment 2, power was actually generated in the fuel cells of Examples 2 to 5 and Comparative Example 4 as described above, and the output voltage was measured. At this time, similarly to the evaluation test of Experiment 1, the output voltage when the power was generated so that the current density of the output current of the fuel cell was 1 [A / cm ² ] was measured.

  FIG. 7 is a diagram showing the results of the evaluation test in Experiment 2. In FIG. In FIG. 7, the vertical axis is a relative value with the measured value of the output voltage of the fuel cell of Comparative Example 3 being 1, and the horizontal axis is the number of repetitions of CV operation and hydrogen pump operation. Further, in FIG. 7, the output voltage of the fuel cell of Example 1 prepared in Experiment 1 above is shown as a reference value by a white symbol, and the output voltage of the fuel cell of Comparative Examples 1 and 3 is shown by a one-dot chain line. Show.

As shown in FIG. 7, although the number of repetitions was set to 1 and the CV operation and the hydrogen pump operation were performed only once each, Comparative Example 4 had a slightly higher output voltage than Comparative Example 1, There is no significant difference.
On the other hand, in Examples 2 to 4 in which the number of repetitions was set to 2 times or more, the output voltage was significantly higher in comparison with Comparative Examples 1 and 4, although the total aging time was 240 minutes. Therefore, it has been verified that the combination of CV operation and hydrogen pump operation can be efficiently activated in a short time by repeatedly performing two or more times.

  Further, when Example 1 with 4 repetitions was compared with Example 3 with 3 repetitions and Example 2 with 2 repetitions, the total aging time of Example 1 (160 minutes) ) Is shorter than the total aging time of these Examples 3 and 4 (240 minutes), but the output voltage is high. Thus, it was verified that it is possible to efficiently activate in a shorter time when the number of repetitions of the combination of the CV operation and the hydrogen pump operation is increased than when the total aging time is increased.

[Experiment 3]
In Experiment 3, in the activation method of the present embodiment, an experiment was performed to compare the effect of repeatedly performing the combination of CV operation and hydrogen pump operation with the effect of increasing the total aging time.

<Example 6>
A fuel cell activated by the activation method of this embodiment is referred to as Example 6. The fuel cell of Example 6 is different from the fuel cell of Example 1 in the time for performing the CV operation per one time, the time for performing the hydrogen pump operation, and the number of repetitions of these combinations.
More specifically, the fuel cell of Example 6 is configured to increase the total aging time by increasing the time for performing the CV operation and the time for performing the hydrogen pump operation for the fuel cell of Example 1. The number of repetitions of the combination of the CV operation and the hydrogen pump operation was reduced to 3 while equalizing the time.

<Example 7>
A fuel cell activated by the activation method of the present embodiment is referred to as Example 7. The fuel cell of Example 7 differs from the fuel cell of Example 1 in the time for performing the CV operation per one time and the time for performing the hydrogen pump operation, and the number of repetitions of these combinations.
More specifically, in the fuel cell of Example 7, the total aging is performed by increasing the time for performing the CV operation and the time for performing the hydrogen pump operation for the fuel cell of Example 1. The number of repetitions of the combination of the CV operation and the hydrogen pump operation was reduced to 2 while equalizing the time.

<Comparative Example 5>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 5. The fuel cell of Comparative Example 5 differs from the fuel cell of Example 1 in the time for performing the CV operation per one time and the time for performing the hydrogen pump operation, and the number of repetitions of these combinations.
More specifically, the fuel cell of Comparative Example 5 is configured to increase the total aging time by increasing the time for performing the CV operation and the time for performing the hydrogen pump operation for the fuel cell of Example 1. The number of repetitions of the combination of the CV operation and the hydrogen pump operation was reduced to 1 while equalizing the time.

<Evaluation test of Experiment 3>
In the evaluation experiment of Experiment 3, power was actually generated in the fuel cells of Examples 1, 2, 3, 6, 7 and Comparative Examples 4 and 5 as described above, and the output voltage was measured. At this time, the output voltage when the power was generated so that the current density of the output current of the fuel battery cell was 1 [A / cm ² ] was measured.

  FIG. 8 is a diagram showing the results of the evaluation test in Experiment 3. In FIG. 8, the relative value which set the measured value of the output voltage of the fuel cell of the comparative example 3 to 1 is shown. As described above, the total aging time of Examples 1, 6, 7 and Comparative Example 5 is 160 minutes, and the total aging time of Examples 2, 3 and Comparative Example 4 is 240 minutes. As shown in FIG. 8, when the number of repetitions is the same despite the total aging time being different, the output voltage is almost the same. Therefore, it was verified that the number of repetitions of the CV operation and the hydrogen pump operation can be activated more efficiently in a shorter time than to increase the total aging time.

It should be noted that the present invention is not limited to the above-described embodiments and examples, and includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in the above embodiment, the hydrogen pump operation (see step S4 in FIG. 2) is executed after the CV operation (see step S3 in FIG. 2), and this is repeated twice or more. Not limited to this. For example, if the order of execution of step S3 and step S4 in FIG. 2 is reversed and the hydrogen pump operation is executed and then the CV operation is executed, and this is repeated twice or more, substantially the same effect is obtained. .

  Further, in the CV operation of the present embodiment, by supplying gas with the cathode side exhaust pipe 23 and the anode side exhaust pipe 33 being opened, the anode side gas is supplied to the anode channel and the cathode channel of the fuel cell FC. Although fresh air supplied from the apparatus and the cathode side supply apparatus circulates, it is not limited to this. In the CV operation, substantially the same effect can be obtained even when the cathode side discharge pipe and / or the anode side discharge pipe are closed.

In the hydrogen pump operation of this embodiment, the reaction gas containing a large amount of hydrogen is supplied to the anode flow path with the shutoff valve provided in the anode side discharge pipe 33 closed, but the present invention is not limited to this. The reaction gas may be supplied with the shutoff valve open.
In the hydrogen pump operation of this embodiment, the shutoff valve provided in the cathode side introduction pipe 22 is closed, but the present invention is not limited to this. For example, nitrogen gas containing a large amount of nitrogen may be supplied to the cathode channel with the shut-off valve opened.

  Moreover, in the said Example, although the activation method of this invention was applied with respect to the single fuel cell, and the effect was verified, this invention is not limited to this. For example, even when the activation method of the present invention is applied to a fuel cell stack configured by laminating a plurality of fuel cells, the same effect can be obtained.

[First Reference Form]
Next, a first reference embodiment of the present invention will be described with reference to the drawings. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
Figure 9 is a diagram schematically showing the configuration of the activation device 1A for performing the method of activating a polymer electrolyte fuel cell FC according to this preferred embodiment.

  The activation device 1A includes a cathode side gas supply device 21 that supplies gas to a cathode flow path that communicates with the cathode electrode of the fuel cell FC, and an anode side that supplies gas to an anode flow path that communicates with the anode electrode of the fuel cell FC. A gas supply device 31 and a humidifier (not shown) that humidifies the gas supplied from the cathode side gas supply device 21 and the anode side gas supply device 31 are provided. In addition, the activation device 1A includes a stabilized power source 4 that applies a voltage between the cathode and anode electrodes of the fuel cell FC, and a variable resistor such as an electronic load device that consumes the power generated by the fuel cell FC. 5 and a changeover switch 6 that selectively switches the connection between the stabilized power source 4 and the fuel cell FC or variable resistor 5 and the fuel cell FC.

Hereinafter, a procedure for activating the fuel cell FC will be described with reference to FIG.
FIG. 10 is a flowchart showing the procedure of the activation method.
In step S11, the fuel cell is replenished with water, and the process proceeds to step S12. More specifically, water is supplied to the MEA of the fuel cell by supplying nitrogen gas humidified by a humidifier to the anode channel and the cathode channel.

  In step S12, the gas in the anode channel and the cathode channel of the fuel cell is replaced, and the process proceeds to step S13. As will be described in detail later, the gas supplied to the fuel cell in the hydrogen pump operation in the next step S13 is different from the gas supplied to the fuel cell for replenishing moisture in the previous step S12. Therefore, in this step S12, a reactive gas is supplied to the anode flow path and the cathode flow path in order to replace the gas remaining in the anode flow path and the cathode flow path of the fuel cell with the gas supplied in the next step S13.

  In step S13, a hydrogen pump operation as a second process described later is performed for a predetermined time, and then the process proceeds to step S14. In step S14, the gas in the anode channel and the cathode channel of the fuel cell is replaced, and the process proceeds to step S15. As will be described in detail later, the gas supplied to the fuel cell in the power generation operation in the next step S15 is different from the gas supplied to the fuel cell in the hydrogen pump operation in the previous step S13. Therefore, in this step S14, in order to replace the gas remaining in the anode flow path and the cathode flow path of the fuel cell with the gas supplied in the next step S15, the reaction gas is supplied to the anode flow path and the cathode flow path is oxidized. Supply agent gas.

  In step S15, after performing the electric power generation operation as a 3rd process mentioned later over predetermined time, it moves to step S16. In step S16, after executing the hydrogen pump operation in step S13, the power generation operation is executed in step S15, and it is determined whether or not this combination has been repeatedly executed a predetermined number of times or more. If this determination is NO, the process moves to step S13, and the combination of the hydrogen pump operation and the power generation operation is executed again. On the other hand, if this determination is YES, the fuel cell activation process is terminated. Here, the set number of times in step S16, that is, the number of times of repeatedly performing the combination of the hydrogen pump operation and the power generation operation, is required by the time for performing the hydrogen pump operation per time, the time for performing the power generation operation per time, and the activation process. It is set to two or more according to the improvement range of the performance of the fuel cell to be performed.

  Hereinafter, the hydrogen pump operation in step S13 and the power generation operation in step S15 will be described in detail with reference to FIGS.

FIG. 11 is a diagram schematically showing the configuration of the activation device in the hydrogen pump operation.
FIG. 12 is a diagram illustrating a change in current density of current flowing from the cathode electrode to the anode electrode when the power generation operation is performed after the hydrogen pump operation is performed. The current density in the present invention refers to a current flowing per unit reaction area (1 [cm ² ]) of the MEA of the fuel cell.

In the hydrogen pump operation, the shutoff valve provided in the cathode side introduction pipe 22 is closed and no gas is supplied to the cathode flow path, and the shutoff valve provided in the anode side discharge pipe 33 is closed to the anode flow path. A reaction gas containing a large amount of hydrogen is supplied.
Further, in the hydrogen pump operation, the fuel cell FC is connected to the stabilization power source 4 and the reaction gas is supplied to the anode electrode of the fuel cell FC as described above. By applying a voltage between the cathode electrode and the anode electrode , a predetermined amount of current flows from the cathode electrode to the anode electrode (see FIG. 12). At this time, the voltage applied by the stabilized power supply 4 is adjusted so that the current flowing from the cathode electrode to the anode electrode becomes a preset value according to the reaction area of the MEA of the fuel cell FC.

As described above, when a current is supplied from the cathode electrode to the anode electrode while supplying the gas, hydrogen ions are generated by the catalytic reaction of hydrogen on the anode electrode side. This hydrogen ion moves to the cathode electrode side through the MEA, receives hydrogen on the cathode electrode side, becomes hydrogen again, and is discharged from the cathode side discharge pipe 23.

FIG. 13 is a diagram schematically showing the configuration of the activation device in the power generation operation.
In the power generation operation, a reaction gas containing a large amount of hydrogen is supplied to the anode flow channel, and an oxidant gas containing a large amount of oxygen is supplied to the cathode flow channel at the same time, and the fuel cell FC generates power. At this time, the shutoff valves provided in the anode side discharge pipe 33 and the cathode side introduction pipe are opened, and the anode side gas supply device 31 and the cathode side gas supply are provided in the anode flow path and the cathode flow path of the fuel cell FC. The fresh air supplied from the apparatus 21 is distributed.

Further, in this power generation operation, the fuel cell FC is connected to the variable resistor 5, and the resistance value of the variable resistor 5 is adjusted while supplying gas to the fuel cell FC and generating power as described above. The output current is periodically changed within a predetermined current width. In this reference embodiment, the output current of the fuel cell is changed in a rectangular wave shape as shown in FIG. 12, for example.

The following describes two experiments conducted to verify the effect of the activation method for a fuel cell according to this preferred embodiment.

[Experiment 4]
In Experiment 4, the activation method of this preferred embodiment, the effect to compare the experiments with conventional activation methods were carried out. More specifically, the fuel cell activated by the activation method of the present reference embodiment is referred to as Reference Example 1, and the fuel cell activated by the conventional activation method is referred to as Comparative Examples 6 to 9, and these Reference Example 1 And the evaluation test was done about Comparative Examples 6-9.

< Reference Example 1 >
The fuel cell was activated by the activation method of this preferred embodiment and the reference example 1. More specifically, a fuel cell activated by the following procedure is referred to as Reference Example 1 .
That is, the fuel cell of Reference Example 1 first replenishes the fuel cell with water (see step S11 described above), replaces the gas in the fuel cell (see step S12 above), and then operates the hydrogen pump (described above step). S13) and power generation operation (see step S15 above) were repeated a predetermined number of times.
More specifically, in hydration of the fuel cell in step S11, nitrogen gas having a temperature of about 70 ° C. and a relative humidity of about 100% was supplied over 30 minutes. Here, the flow rate of nitrogen gas was adjusted so that the flow rate per unit reaction area of MEA was 4 [ml / min].
In the replacement of the fuel cell gas in step S12, the reaction gas was supplied to the anode channel and the cathode channel over 3 minutes. Here, the flow rate of the reaction gas was adjusted so that the flow rate per unit reaction area of MEA was 8 [ml / min].
In the hydrogen pump operation in step S13, the shutoff valves of the cathode side introduction pipe and the anode side discharge pipe are closed, and the reaction gas is supplied to the anode flow path. Here, the flow rate of the reaction gas was the same as the flow rate of step S12 described above. In the hydrogen pump operation, the anode electrode is connected to the positive electrode of the stabilized power source, the cathode electrode is connected to the negative electrode of the stabilized power source, and the current density is supplied from the cathode electrode to the anode electrode while supplying the reaction gas as described above. Continued to pass a current of 1 [A / cm ² ] for 9 minutes.
In the replacement of the fuel cell gas in step S14, the shutoff valves of the cathode side introduction pipe and the anode side discharge pipe were opened, and the reaction gas was supplied to the anode channel and the oxidant gas was supplied to the cathode channel for 3 minutes. Here, the flow rate of the reaction gas supplied to the anode flow path is adjusted so that the flow rate per unit reaction area of MEA is 14 [ml / min], and the flow rate of the oxidant gas supplied to the cathode flow path is The flow rate per unit reaction area of MEA was adjusted to 33 [ml / min].
In the power generation operation in step S15, the fuel cell is connected to the variable resistor, and the reaction gas and the oxidant gas are supplied at the same flow rate as in step S14, and the fuel cell generates power, and the resistance value of the variable resistor is adjusted to generate the fuel. Vary the battery output current. The output current of the fuel cell was varied according to the following procedure. First, the current density is increased from 0 [A / cm ² ] to 1 [A / cm ² ] at a rate of 100 [mA / cm ² ] per second, and this state is maintained for 1 minute. Next, the current density is decreased from 1 [A / cm ² ] to 0 [A / cm ² ] at a rate of 200 [mA / cm ² ] per second, and this state is maintained for 1 minute. With the above as one cycle, in the power generation operation of step S15, the output current of the fuel cell was changed over four cycles (9 minutes in total).
In addition, the number of repetitions of step S16 is set to 13. Therefore, the total aging time of the fuel cell of Reference Example 1 is 234 minutes.

<Comparative Example 6>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 6. The fuel cell of Comparative Example 6 differs from the fuel cell of Reference Example 1 described above in that it is activated by performing only the power generation operation without performing the hydrogen pump operation, and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Reference Example 1 . Next, a power generation operation was performed under the same settings as in Reference Example 1, and the output current of the fuel cell was varied over 107 cycles (240 minutes 45 seconds). Therefore, the total aging time of the fuel cell of Comparative Example 6 is 240 minutes and 45 seconds.

<Comparative Example 7>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 7. The fuel cell of Comparative Example 7 is different from the fuel cell of Reference Example 1 described above in that it is activated by performing only the hydrogen pump operation without performing the power generation operation, and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Reference Example 1 . Next, the hydrogen pump operation was performed for 240 minutes under the same settings as in Reference Example 1 . Therefore, the total aging time of the fuel cell of Comparative Example 7 is 240 minutes.

<Comparative Example 8>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 8. The fuel cell of Comparative Example 7 differs from the fuel cell of Reference Example 1 described above in that the combination of the power generation operation and the hydrogen pump operation was performed only once without repeating it twice or more, and the total aging time was different .
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Reference Example 1 . Next, a power generation operation was performed under the same settings as in Reference Example 1, and the output current of the fuel cell was varied over 107 cycles (240 minutes 45 seconds). Then, after replacing the fuel cell of the gas under the same settings as in Reference Example 1, it was performed for 240 min hydrogen pump operation under the same settings as in Reference Example 1. Therefore, the total aging time of the fuel cell of Comparative Example 8 is 480 minutes 45 seconds.

<Comparative Example 9>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 9. The fuel cell of Comparative Example 9 differs from the fuel cell of Reference Example 1 described above in that neither the power generation operation nor the hydrogen pump operation was performed, and the total aging time.
More specifically, according to the same procedure as in Reference Example 1 , only water replenishment and gas replacement of the fuel cells were performed. Therefore, the total aging time of the fuel cell of Comparative Example 9 is 0 minute.

<Evaluation test of Experiment 4>
In the evaluation test of Experiment 4, power was actually generated in the fuel cells of Reference Example 1 and Comparative Examples 6-9 as described above, and the output voltage was measured. At this time, the output voltage when the power was generated so that the current density of the output current of the fuel battery cell was 1 [A / cm ² ] was measured.

FIG. 14 is a diagram showing the results of the evaluation test in Experiment 4. In FIG. 14, the relative value which set the measured value of the output voltage of the fuel cell of the comparative example 9 to 1 is shown.
As shown in FIG. 14, the fuel cell of Reference Example 1 has a higher output voltage despite the shorter total aging time than Comparative Examples 6 and 7. Thus, by activating activation method of this preferred embodiment, can be efficiently activated in a shorter time than the conventional method of activation is verified. Further, the fuel cell of Reference Example 1 activated by repeatedly executing the combination of the hydrogen pump operation and the power generation operation twice or more is a comparative example activated by executing the combination of the power generation operation and the hydrogen pump operation only once. Although the total aging time is shorter than that of the fuel cell 8, the output voltage is high. Therefore, it was verified that the combination of the hydrogen pump operation and the power generation operation can be efficiently activated in a short time by repeatedly performing the combination twice or more.

[Experiment 5]
In Experiment 5, the activation method of this preferred embodiment, the combination to verify the effect by repeating the experiments with the power generation operation and the hydrogen pump operation was performed. More specifically, the fuel cell activated with the activation method of this preferred embodiment as Reference Example 2-5, the fuel cell activation with conventional activation method as Comparative Example 10, these reference examples 2 an evaluation test was conducted for 1-5 and Comparative example 10.

In addition, the setting of the current supplied to the fuel cell during the hydrogen pump operation in Reference Examples 2 to 5 and Comparative Example 10 and the variation mode of the output current of the fuel cell during the power generation operation are the same as in Reference Example 1 above. Description is omitted.

< Reference Example 2 >
The fuel cell was activated by the activation method of this preferred embodiment and reference example 2.
More specifically, the hydrogen pump operation time per operation is 60 minutes, the power generation operation time per operation is 63 minutes (28 cycles), and the combination of hydrogen pump operation and power generation operation is repeated. The number of times was two. Therefore, the total aging time is 246 minutes.

< Reference Example 3 >
The fuel cell was activated by the activation method of this preferred embodiment and reference example 3.
More specifically, the time for one hydrogen pump operation is 40 minutes, the time for one power generation operation is 36 minutes (16 cycles), and the combination of hydrogen pump operation and power generation operation is repeated. The number of times was three. Therefore, the total aging time is 228 minutes.

< Reference Example 4 >
The fuel cell was activated by the activation method of this preferred embodiment and reference example 4.
More specifically, the time for performing the hydrogen pump operation per time is 24 minutes, the time for performing the power generation operation per time is 27 minutes (12 cycles), and the combination of the hydrogen pump operation and the power generation operation is repeated. The number of times was five. Therefore, the total aging time is 255 minutes.

< Reference Example 5 >
The fuel cell was activated by the activation method of this preferred embodiment is Reference Example 5.
More specifically, the time for performing the hydrogen pump operation per time is 10 minutes, the time for performing the power generation operation per time is 18 minutes (8 cycles), and the combination of the hydrogen pump operation and the power generation operation is repeated. The number of times was 10 times. Therefore, the total aging time is 280 minutes.

<Comparative Example 10>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 10.
More specifically, after the hydrogen pump operation was performed for 120 minutes, the power generation operation was performed for 117 minutes (52 cycles). Therefore, the total aging time is 237 minutes.

<Evaluation test of Experiment 5>
In the evaluation test of Experiment 5, power was actually generated in the fuel cells of Reference Examples 2 to 5 and Comparative Example 10 as described above, and the output voltage was measured. At this time, similarly to the evaluation test of Experiment 4, the output voltage when the power was generated so that the current density of the output current of the fuel cell was 1 [A / cm ² ] was measured.

  FIG. 15 is a diagram illustrating the results of the evaluation test of Experiment 5. In FIG. In FIG. 15, the vertical axis is a relative value with the measured value of the output voltage of the fuel cell of Comparative Example 9 being 1, and the horizontal axis is the number of repetitions of the power generation operation and the hydrogen pump operation.

As shown in FIG. 15, the fuel cell of Comparative Example 10 in which the number of repetitions was one and the hydrogen pump operation and the power generation operation were performed only once was Comparative Example 9 or Comparative Examples 6 and 7 (FIG. 14). Although the output voltage is slightly higher than that of (see), there is no significant difference.
On the other hand, in Reference Examples 2 to 5 in which the number of repetitions is 2 or more, the output voltage is high although the total aging time is substantially the same as in Comparative Examples 6 and 10. Therefore, it was verified that the combination of the hydrogen pump operation and the power generation operation can be efficiently activated in a short time by repeatedly performing two or more times.

In addition, this invention is not limited to the said reference form and the said reference example, The deformation | transformation in the range which can achieve the objective of this invention, improvement, etc. are included in this invention.
For example, in this preferred embodiment, to perform a hydrogen pump operation (see step S13 in FIG. 10) power generating operation continues after running (see step S15 in FIG. 10), although this was repeated twice more, the present invention is Not limited to this. For example, if the order of execution of steps S13 and S15 in FIG. 10 is reversed and the power generation operation is executed and then the hydrogen pump operation is executed, and this is repeated twice or more, substantially the same effect is obtained. .

Also, the hydrogen pump operation of the present reference embodiment has been supplying a reaction gas containing a large amount of hydrogen to the anode channel with closed shut-off valve provided on the anode side exhaust pipe 33, the present invention is not limited thereto The reaction gas may be supplied with the shutoff valve open.
Also, the hydrogen pump operation of the present reference embodiment, although closed shut-off valve provided on the cathode side inlet pipe 22, the present invention is not limited thereto. For example, nitrogen gas containing a large amount of nitrogen may be supplied to the anode channel with the shut-off valve opened.

Further, in the power generation operation of the present reference embodiment, although the output current of the fuel cell FC is varied in a rectangular wave shape, the present invention is not limited thereto. The waveform of the output current of the fuel cell may be, for example, a sine wave or a sawtooth wave.

In the above reference example, the activation method of the present invention is applied to a single fuel cell, and the effect thereof is verified. However, the present invention is not limited to this. For example, even when the activation method of the present invention is applied to a fuel cell stack configured by laminating a plurality of fuel cells, the same effect can be obtained.

[Third Embodiment]
Hereinafter, a third embodiment of the present invention will be described with reference to the drawings. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.
FIG. 16 is a diagram schematically showing a configuration of an activation device 1B for executing the activation method of the polymer electrolyte fuel cell FC according to the present embodiment.

  The activation device 1B includes a cathode-side gas supply device 21 that supplies gas to a cathode flow path that communicates with the cathode electrode of the fuel cell FC, and an anode-side that supplies gas to an anode flow path that communicates with the anode electrode of the fuel cell FC. A gas supply device 31 and a humidifier (not shown) that humidifies the gas supplied from the cathode side gas supply device 21 and the anode side gas supply device 31 are provided. In addition, the activation device 1B includes a stabilized power source 4 that applies a voltage between the cathode electrode and the anode electrode of the fuel cell FC, and a variable resistor such as an electronic load device that consumes power generated by the fuel cell FC. 5 and a changeover switch 6 that selectively switches the connection between the stabilized power source 4 and the fuel cell FC or variable resistor 5 and the fuel cell FC.

Hereinafter, the procedure for activating the fuel cell FC will be described with reference to FIG.
FIG. 17 is a flowchart showing the procedure of the activation method.
In step S21, water is supplied to the fuel cell, and the process proceeds to step S22. More specifically, water is supplied to the MEA of the fuel cell by supplying nitrogen gas humidified by a humidifier to the anode channel and the cathode channel.

  In step S22, the gas in the anode channel and the cathode channel of the fuel cell is replaced, and the process proceeds to step S23. As will be described in detail later, the gas supplied to the fuel cell in the CV operation of the next step S23 is different from the gas supplied to the fuel cell for replenishing moisture in the previous step S22. Therefore, in this step S22, a reactive gas is supplied to the anode flow path and the cathode flow path in order to replace the gas remaining in the anode flow path and the cathode flow path of the fuel cell with the gas supplied in the next step S23.

  In step S23, after a CV operation as a first step described later is performed for a predetermined time, the process proceeds to step S24. In step S24, the gas in the anode channel and the cathode channel of the fuel cell is replaced, and the process proceeds to step S25. As will be described in detail later, the gas supplied to the fuel cell in the power generation operation in the next step S25 is different from the gas supplied to the fuel cell in the CV operation in the previous step S23. Therefore, in this step S24, in order to replace the gas remaining in the anode flow path and the cathode flow path of the fuel cell with the gas supplied in the next step S25, the reaction gas is supplied to the anode flow path and the oxidant is supplied to the cathode flow path. Supply gas.

  In step S25, after the power generation operation as a third process described later is executed for a predetermined time, the process proceeds to step S26. In step S26, after executing the CV operation in step S23, the power generation operation is executed in step S25, and it is determined whether or not this combination has been repeatedly executed a predetermined number of times or more. If this determination is NO, the process moves to step S23, and the combination of CV operation and power generation operation is executed again. On the other hand, if this determination is YES, the fuel cell activation process is terminated. Here, the set number of times in step S26, that is, the number of times of repeatedly performing the combination of the CV operation and the power generation operation, is required by the time for performing the CV operation per time, the time for performing the power generation operation per time, and the activation process. It is set to 2 times or more according to the improvement width of the performance of the fuel cell.

  Hereinafter, the CV operation in step S23 and the power generation operation in step S25 will be described in detail with reference to FIGS.

FIG. 18 is a diagram schematically showing the configuration of the activation device in the CV operation.
FIG. 19 is a diagram illustrating a change in voltage between the cathode electrode and the anode electrode when the CV operation is performed. The current density in the present invention refers to a current flowing per unit reaction area (1 [cm ² ]) of the MEA of the fuel cell.

  In the CV operation, a reaction gas containing a large amount of hydrogen is supplied to the anode flow channel, and at the same time, a nitrogen gas containing a large amount of nitrogen is supplied to the cathode flow channel without supplying an oxidant gas containing a large amount of oxygen. At this time, the shutoff valves provided in the anode side discharge pipe 33 and the cathode side introduction pipe 22 are opened, and the anode side gas supply device 31 and the cathode side gas are provided in the anode flow path and the cathode flow path of the fuel cell FC. Fresh air supplied from the supply device 21 is distributed.

  Further, in the CV operation, the fuel cell FC is connected to the stabilized power source 4 and the gas is supplied to the fuel cell FC as described above. A voltage that periodically fluctuates within a predetermined voltage width is applied between them (see FIG. 19). Here, the minimum value of the voltage width is set to a predetermined value of 0 [V] or more (for example, 0 [V]), and the maximum value is set to a predetermined value (for example, 1 [V]) larger than the minimum value. Further, the voltage waveform is preferably a sine wave as shown in FIG. 19 in order to prevent the current from fluctuating rapidly when the voltage is turned back, but is not limited to this, and is a sawtooth wave or a rectangular wave. Also good.

FIG. 20 is a diagram schematically showing the configuration of the activation device in the power generation operation.
FIG. 21 is a diagram illustrating a change in current density of a current flowing from the cathode electrode to the anode electrode when the power generation operation is performed.

  In the power generation operation, a reaction gas containing a large amount of hydrogen is supplied to the anode flow channel, and an oxidant gas containing a large amount of oxygen is supplied to the cathode flow channel at the same time, and the fuel cell FC generates power. At this time, the shutoff valves provided in the anode side discharge pipe 33 and the cathode side introduction pipe are opened, and the anode side gas supply device 31 and the cathode side gas supply are provided in the anode flow path and the cathode flow path of the fuel cell FC. The fresh air supplied from the apparatus 21 is distributed.

  Further, in this power generation operation, the fuel cell FC is connected to the variable resistor 5, and the resistance value of the variable resistor 5 is adjusted while supplying gas to the fuel cell FC and generating power as described above. The output current is periodically changed within a predetermined current width. In the present embodiment, the output current of the fuel cell is changed in a rectangular wave shape as shown in FIG. 19, for example.

  Hereinafter, two experimental results performed to verify the effect of the fuel cell activation method according to the present embodiment will be described.

[Experiment 6]
In Experiment 6, an experiment was performed to compare the effects of the activation method of the present embodiment and the conventional activation method. More specifically, the fuel cell activated by the activation method of the present embodiment is referred to as Example 13, and the fuel cell activated by the conventional activation method is referred to as Comparative Examples 11 to 13, and these Example 13 And the evaluation test was done about Comparative Examples 11-13.

<Example 13>
The fuel cell activated by the activation method of this embodiment is referred to as Example 13. More specifically, Example 13 is a fuel cell activated by the following procedure.
That is, the fuel cell of Example 13 first replenishes the fuel cell with water (see step S21 above), replaces the fuel cell gas (see step S22 above), and then performs CV operation (step S23 above). Reference) and power generation operation (see step S25 above) were repeated a predetermined number of times.
More specifically, in hydration of the fuel cell in step S21, nitrogen gas having a temperature of about 70 ° C. and a relative humidity of about 100% was supplied over 30 minutes. Here, the flow rate of nitrogen gas was adjusted so that the flow rate per unit reaction area of MEA was 4 [ml / min].
In the replacement of the fuel cell gas in step S22, the reaction gas was supplied to the anode channel and the nitrogen gas was supplied to the cathode channel for 3 minutes. Here, the flow rates of the reaction gas and the nitrogen gas were adjusted so that the flow rate per unit reaction area of MEA was 8 [ml / min].
In the CV operation of step S23, the gas is supplied at the same flow rate as in step S22 described above, and the minimum voltage 0 [V], the maximum voltage 1 [V], and a sine waveform voltage of 1 cycle for 6 cycles (5 cycles ( For 30 minutes).
In the replacement of the fuel cell gas in step S24, the reaction gas was supplied to the anode channel and the oxidant gas was supplied to the cathode channel for 3 minutes. Here, the flow rate of the reaction gas supplied to the anode flow path is adjusted so that the flow rate per unit reaction area of MEA is 14 [ml / min], and the flow rate of the oxidant gas supplied to the cathode flow path is The flow rate per unit reaction area of MEA was adjusted to 33 [ml / min].
In the power generation operation in step S25, the fuel cell is connected to the variable resistor, and the reaction gas and the oxidant gas are supplied at the same flow rate as in step S24 and the fuel cell generates power, and the resistance value of the variable resistor is adjusted to generate fuel. Vary the battery output current. The output current of the fuel cell was varied according to the following procedure. First, the current density is increased from 0 [A / cm ² ] to 1 [A / cm ² ] at a rate of 100 [mA / cm ² ] per second, and this state is maintained for 1 minute. Next, the current density is decreased from 1 [A / cm ² ] to 0 [A / cm ² ] at a rate of 200 [mA / cm ² ] per second, and this state is maintained for 1 minute. With the above as one cycle, in the power generation operation of step S25, the output current of the fuel cell was changed over five cycles (11 minutes and 15 seconds in total).
In addition, the number of repetitions of step S25 is four. Therefore, the total aging time of the fuel battery cell of Example 13 is 165 minutes.

<Comparative Example 11>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 11. The fuel cell of Comparative Example 11 is different from the fuel cell of Example 13 described above in that the fuel cell of Comparative Example 11 was activated by performing only the power generation operation without performing the CV operation, and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Example 13. Next, a power generation operation was performed under the same setting as in Example 13, and the output current of the fuel cell was varied over 107 cycles (240 minutes 45 seconds). Therefore, the total aging time of the fuel cell of Comparative Example 11 is 240 minutes and 45 seconds.

<Comparative Example 12>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 12. The fuel cell of Comparative Example 12 is different from the fuel cell of Example 13 described above in that it is activated by executing only the CV operation without executing the power generation operation and the total aging time.
More specifically, first, water replenishment and gas replacement of the fuel cells were performed by the same procedure as in Example 13. Next, CV operation was performed for 240 minutes (40 cycles) under the same settings as in Example 13. Therefore, the total aging time of the fuel cell of Comparative Example 11 is 240 minutes.

<Comparative Example 13>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 13. The fuel cell of Comparative Example 13 differs from the fuel cell of Example 13 described above in that neither the CV operation nor the power generation operation was performed, and the total aging time.
More specifically, the fuel cell was rehydrated and replaced with gas by the same procedure as in Example 13. Therefore, the total aging time of the fuel cell of Comparative Example 13 is 0 minute.

<Evaluation test of Experiment 6>
In the evaluation test of Experiment 6, power was actually generated in the fuel cells of Example 13 and Comparative Examples 11 to 13 and the output voltage was measured. At this time, the output voltage when the power was generated so that the current density of the output current of the fuel battery cell was 1 [A / cm ² ] was measured.

FIG. 22 is a diagram illustrating the results of the evaluation test of Experiment 6. In FIG. In FIG. 22, the relative value which set the measured value of the output voltage of the fuel cell of the comparative example 13 to 1 is shown.
As shown in FIG. 22, the fuel cell of Example 13 has a higher output voltage than the comparative examples 11 and 12, although the total aging time is shorter. Therefore, it has been verified that activation by the activation method of the present embodiment enables efficient activation in a shorter time than the conventional activation method.

[Experiment 7]
In Experiment 7, in the activation method of the present embodiment, an experiment was conducted to verify the effect of repeatedly performing a combination of CV operation and power generation operation. More specifically, the fuel cells activated by the activation method of the present embodiment are designated as Examples 14 to 16, the fuel cells activated by the conventional activation method are designated as Comparative Example 14, and these Examples 14 Evaluation tests were performed on -16 and Comparative Example 14.

  In addition, the setting of the current supplied to the fuel cell during the CV operation of Examples 14 to 16 and Comparative Example 14 and the variation mode of the output current of the fuel cell during the power generation operation are the same as in Example 13 described above. Is omitted.

<Example 14>
The fuel cell activated by the activation method of this embodiment is referred to as Example 14.
More specifically, the time for performing CV operation per time is 60 minutes (10 cycles), the time for performing power generation operation per time is 63 minutes (28 cycles), and a combination of CV operation and power generation operation Was repeated twice. Therefore, the total aging time is 246 minutes.

<Example 15>
A fuel cell activated by the activation method of this embodiment is referred to as Example 15.
More specifically, the time for performing CV operation per time is 42 minutes (7 cycles), the time for performing power generation operation per time is 36 minutes (16 cycles), and a combination of CV operation and power generation operation. Was repeated three times. Therefore, the total aging time is 234 minutes.

<Example 16>
A fuel cell activated by the activation method of this embodiment is referred to as Example 16.
More specifically, the time for performing CV operation per time is 24 minutes (4 cycles), the time for performing power generation operation per time is 27 minutes (12 cycles), and a combination of CV operation and power generation operation. Was repeated 5 times. Therefore, the total aging time is 255 minutes.

<Comparative example 14>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 14.
More specifically, after performing the CV operation for 120 minutes (20 cycles), the power generation operation was performed for 117 minutes (52 cycles), and the CV operation and the power generation operation were performed for a total of 237 minutes.

<Evaluation test of Experiment 7>
In the evaluation test of Experiment 7, power was actually generated in the fuel cells of Examples 14 to 16 and Comparative Example 14 as described above, and the output voltage was measured. At this time, similarly to the evaluation test of Experiment 6, the output voltage was measured when the power was generated so that the current density of the output current of the fuel cell was 1 [A / cm ² ].

  FIG. 23 is a diagram showing the results of the evaluation test in Experiment 7. In FIG. 23, the vertical axis is a relative value with the measured value of the output voltage of the fuel cell of Comparative Example 13 being 1, and the horizontal axis is the number of repetitions of CV operation and power generation operation.

  As shown in FIG. 23, Examples 14 to 16 in which the number of repetitions is set to 2 or more are compared with Comparative Example 14 in which the number of repetitions is 1 and the CV operation and the power generation operation are performed only once. The output voltage is significantly higher despite the total aging time being approximately the same. Therefore, it has been verified that increasing the number of repetitions of the combination of the CV operation and the power generation operation can be efficiently activated in a shorter time.

It should be noted that the present invention is not limited to the present embodiment and the above examples, but includes modifications and improvements as long as the object of the present invention can be achieved.
For example, in this embodiment, after the CV operation (see step S23 in FIG. 17) is executed, the power generation operation (see step S25 in FIG. 17) is executed, and this is repeated twice or more. Not limited to. For example, if the order of execution of steps S23 and S25 in FIG. 17 is reversed and the power generation operation is executed and then the CV operation is executed, and this is repeated twice or more, substantially the same effect is obtained.

  Further, in the CV operation of the present embodiment, by supplying gas with the cathode side exhaust pipe 23 and the anode side exhaust pipe 33 being opened, the anode side gas is supplied to the anode channel and the cathode channel of the fuel cell FC. Although fresh air supplied from the apparatus and the cathode side supply apparatus circulates, it is not limited to this. In the CV operation, substantially the same effect can be obtained even when the cathode side discharge pipe and / or the anode side discharge pipe are closed.

  In the power generation operation of the present embodiment, the output current of the fuel cell FC is changed in a rectangular wave shape, but the present invention is not limited to this. The waveform of the output current of the fuel cell may be, for example, a sine wave or a sawtooth wave.

  Moreover, in the said Example, although the activation method of this invention was applied with respect to the single fuel cell, and the effect was verified, this invention is not limited to this. For example, even when the activation method of the present invention is applied to a fuel cell stack configured by laminating a plurality of fuel cells, the same effect can be obtained.

[ Second Reference Form]
Next, a second reference embodiment of the present invention will be described with reference to the drawings. This reference form is different from the first reference form in the specific procedure of power generation operation. In the following description, the same components as those in the first reference embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

Figure 24 is a diagram schematically showing the configuration of the activation device 1C to perform the activation process of a polymer electrolyte fuel cell FC according to this preferred embodiment.
The activation device 1C includes a cathode-side gas supply device 21, an anode-side gas supply device 31, a humidifier (not shown), and a stabilized power source 4 that applies a voltage between the cathode electrode and the anode electrode of the fuel cell FC. And a switch 7 for intermittently connecting the stabilized power source 4 and the fuel cell FC.

FIG. 25 is a flowchart showing the procedure of the activation method.
Steps S31 and S32 are the same as steps S11 and S12 in the first reference embodiment, respectively, and thus description thereof is omitted.
In step S33, a hydrogen pump operation described later is performed for a predetermined time, and then the process proceeds to step S35. A power generation operation described later is subsequently performed for a predetermined time, and then the process proceeds to step S36. In step S36, it is determined whether or not the combination of the hydrogen pump operation (S33) and the power generation operation (S35) has been repeatedly executed a predetermined number of times or more. Here, the set number of times in step S36 is set to two times or more as in the first reference embodiment.

Next, specific procedures for the hydrogen pump operation in step S33 and the power generation operation in step S35 will be described in detail with reference to FIGS.
FIG. 26 is a diagram schematically showing the configuration of the activation device in the hydrogen pump operation.
The procedure for operating the hydrogen pump is the same as in the first reference embodiment. That is, the shutoff valve provided in the cathode side introduction pipe 22 is closed and no gas is supplied to the cathode flow path, and the shutoff valve provided in the anode side discharge pipe 33 is closed and the reaction gas is supplied to the anode flow path. Supply. Furthermore, the positive electrode of the stabilized power source 4 was connected to the anode electrode of the fuel cell FC, the negative electrode of the stabilized power source 4 was connected to the cathode electrode of the fuel cell FC, and the reaction gas was supplied to the anode electrode of the fuel cell FC as described above. In this state, a predetermined voltage is applied by the stabilized power supply 4. Thereby, an electric current is induced in the fuel cell FC and hydrogen is discharged from the cathode side discharge pipe 23.

FIG. 27 is a diagram schematically showing the configuration of the activation device in the power generation operation.
In the power generation operation, the shutoff valve of the cathode side introduction pipe 22 is opened while the voltage is applied to the fuel cell FC from the stabilized power source 4 and the reaction gas is supplied to the anode flow channel following the hydrogen pump operation described above, To supply oxidant gas. Thus, in the power generation operation of Embodiment while continuously performed the hydrogen pump reaction, partially generator reactions to proceed (some generator).

FIG. 28 is a time chart showing a change in voltage between the cathode electrode and the anode electrode (hereinafter referred to as a stack voltage) when the oxidant gas is supplied to the cathode channel during the hydrogen pump operation. In FIG. 28, the upper time chart shows the case where the oxidizing gas is supplied at a relatively small flow rate, and the lower time chart shows the case where the oxidizing gas is supplied at a larger flow rate.
As shown in FIG. 28, while only the hydrogen pump operation is performed, the stack voltage is maintained at a predetermined negative value by the stabilized power source. When the supply of oxidant gas is further started from such a state, the power generation reaction proceeds in the fuel cell, so that the stack voltage rises to the positive side. Thus, the hydrogen pump reaction and the power generation reaction can be performed in parallel by supplying the oxidant gas at a small flow rate with respect to the current induced by the hydrogen pump reaction.
However, as shown in the lower time chart of FIG. 28, when the flow rate of the oxidant gas is increased, the polarity of the stack voltage changes between during the hydrogen pump operation and during the power generation operation. Therefore, when the hydrogen pump operation and the power generation operation are repeatedly performed as described above, the flow rate of the oxidant gas supplied in the power generation operation is set to an amount that does not change the polarity in consideration of the power generation efficiency by the fuel cell. Thereby, the cost concerning a power supply can be reduced.

It will now be described results of an experiment performed for verifying the effectiveness of the activation method for a fuel cell according to this preferred embodiment.

[Experiment 8]
In Experiment 8, the activation method of this preferred embodiment, the effect to compare the experiments with conventional activation methods were carried out. More specifically, the fuel cell activated with the activation method of this preferred embodiment as Reference Example 6, the fuel cell activation with conventional activation method as Comparative Example 15 to 17, these reference examples 6 And the evaluation test was done about Comparative Examples 15-17.

< Reference Example 6 >
A fuel cell activated by the activation method of this reference embodiment is referred to as Reference Example 6 . More specifically, a fuel cell activated by the following procedure is referred to as Reference Example 6 .
More specifically, in the water replenishment of the fuel cell in step S31, nitrogen gas having a temperature of about 70 ° C. and a relative humidity of about 100% was supplied over 30 minutes. Here, the flow rate of nitrogen gas was adjusted so that the flow rate per unit reaction area of MEA was 4 [ml / min].
In the replacement of the fuel cell gas in step S32, the reaction gas and the oxidant gas were respectively supplied to the anode channel and the cathode channel for 3 minutes. Here, the flow rates of the reaction gas and the oxidant gas were adjusted so that the flow rate per unit reaction area of MEA was 8 [ml / min].
In the hydrogen pump operation of step S33, the shutoff valves of the cathode side introduction pipe and the anode side discharge pipe are closed, and the reaction gas is supplied to the anode flow path. Here, the flow rate of the reaction gas was the same as the flow rate of step S32 described above. In the hydrogen pump operation, the anode electrode is connected to the positive electrode of the stabilizing power source, the cathode electrode is connected to the negative electrode of the stabilizing power source, and the density is increased from the cathode electrode to the anode electrode while supplying the reaction gas as described above. A current of 1 [A / cm ² ] was kept flowing for 5 minutes.
In the power generation operation in step S35, the reaction gas is continuously supplied from the hydrogen pump operation and the power supply is stably connected, and while the current having the density of 1 [A / cm ² ] continues to flow, The oxidant gas was supplied to the cathode channel at a predetermined flow rate for 5 minutes. Here, the flow rate of the oxidant gas supplied to the cathode flow path is equal to or less than an amount determined so that the polarity does not change as described above, more specifically, 8 [ml / min] per unit area of MEA. It adjusted so that it might become.
In addition, the number of repetitions of step S36 is 24. Therefore, the total aging time of the fuel cell of Reference Example 6 is 240 minutes.

<Comparative Example 15>
In the fuel cell of Comparative Example 15, only the water replenishment and gas replacement of the fuel cell were performed by the same procedure as in Reference Example 6 . Therefore, the total aging time of the fuel cell of Comparative Example 15 is 0 minute.

<Comparative Example 16>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 16. More specifically, first, by the same procedure as Reference Example 6, after hydration and gas replacement of the fuel cell, it was performed for 240 min hydrogen pump operation under the same settings as in Reference Example 6. Therefore, the total aging time of the fuel cell of Comparative Example 16 is 240 minutes.

<Comparative Example 17>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 17. More specifically, first, by the same procedure as Reference Example 6, after hydration and gas replacement of the fuel cell was subjected to power generation operation under the same settings as in Reference Example 6 over 240 minutes. Therefore, the total aging time of the fuel cell of Comparative Example 17 is 240 minutes.

<Comparative Example 18>
A fuel cell activated by a conventional activation method is referred to as Comparative Example 18. More specifically, after activation by the same procedure as Comparative Example 16, it was further activated by the same procedure as Comparative Example 17. Therefore, the total aging time of the fuel cell of Comparative Example 18 is 480 minutes.

<Evaluation test of Experiment 8>
In the evaluation test of Experiment 8, power was actually generated in the fuel cells of Reference Example 6 and Comparative Examples 15 to 18 as described above, and the output voltage was measured. At this time, the output voltage when the power was generated so that the current density of the output current of the fuel battery cell was 1 [A / cm ² ] was measured.

FIG. 29 is a diagram showing the results of the evaluation test in Experiment 8. In FIG. 29, the relative value which set the measured value of the output voltage of the fuel cell of the comparative example 15 to 1 is shown.
As shown in FIG. 29, the fuel cell of Reference Example 6 has an output voltage that is shorter than that of Comparative Example 18 as well as Comparative Examples 17 and 18 that have the same total aging time. Is expensive. Thus, by activating activation method of this preferred embodiment, can be efficiently activated in a shorter time than the conventional method of activation is verified. Further, the fuel cell of Reference Example 6 activated by repeatedly executing the combination of the hydrogen pump operation and the power generation operation twice or more was compared and activated by executing the combination of the smoke generation operation and the hydrogen pump operation only once. Although the total aging time is shorter than the fuel cell of Example 18, the output voltage is high. Therefore, it was verified that the combination of the hydrogen pump operation and the power generation operation can be efficiently activated in a short time by repeatedly performing the combination twice or more.

Further, in the activation method of the present reference embodiment, since the hydrogen pump operation and the power generation operation can be switched only by starting or stopping the supply of the oxidant gas, the activation method of the first reference embodiment described above. Compared with, it can be performed easily.

[ Third Reference Form]
Next, a third reference embodiment of the present invention will be described with reference to the drawings. This reference form is different from the first reference form in the specific procedure of the power generation operation and the hydrogen pump operation. In the following description, the same components as those in the first reference embodiment are denoted by the same reference numerals, and detailed description thereof is omitted.

Figure 30 is a diagram schematically showing the configuration of the activation device 1D for carrying out the method of activating a polymer electrolyte fuel cell FC according to this preferred embodiment.
The activation device 1D includes a cathode-side gas supply device 21, an anode-side gas supply device 31, a humidifier (not shown), and a stabilized power source 4 that applies a voltage between the cathode electrode and the anode electrode of the fuel cell FC. And an electronic load device 8 connected between the stabilized power source 4 and the fuel cell FC.

FIG. 31 is a flowchart showing the procedure of the activation method.
Steps S41 and S42 are the same as steps S11 and S12 in the first reference embodiment, respectively, and thus the description thereof is omitted.

  In step S43, as preparation for repeatedly executing the power generation operation (S44) and the hydrogen pump operation (S45), voltage application by the stabilized power supply, supply of the reaction gas to the anode flow path, and oxidation to the cathode flow path are performed. After the supply of the agent gas is started, the process proceeds to step S44.

In step S44, after a power generation operation described later is performed for a predetermined time, the process proceeds to step S45, and subsequently a hydrogen pump operation described later is performed for a predetermined time, and then the process proceeds to step S46. In step S46, it is determined whether or not the combination of the power generation operation (S44) and the hydrogen pump operation (S45) has been repeatedly executed a predetermined number of times or more. Here, the set number of times in step S46 is set to two times or more as in the first reference embodiment.

FIG. 32 is a diagram illustrating changes in the current (horizontal axis) and the stack voltage (vertical axis) of the electronic load device during the power generation operation and the hydrogen pump operation.
In the power generation operation in step S44, the current of the electronic load device is gradually increased to a predetermined value while the application of the voltage from the stabilized power source and the supply of the reaction gas and the oxidant gas to the anode channel and the cathode channel are continued. Let
Subsequently, in the hydrogen pump operation in step S45, first, the supply of the oxidant gas to the cathode flow path is stopped, and the power generation reaction in the fuel cell is stopped. Then, as shown in FIG. 32, the stack voltage decreases to 0 or less. Thereafter, the current of the electronic load device is gradually decreased toward zero. During this time, a voltage is applied to the fuel cell by the stabilized power source and a reaction gas is supplied to the anode flow path, so that the hydrogen pump reaction proceeds. Thereafter, the supply of the oxidant gas is started again, and the power generation by the fuel cell is started. Then, the power generation operation in step S44 is started again.

< Reference Example 7 >
The fuel cell was activated by the activation method of this preferred embodiment and reference example 7. More specifically, a fuel cell activated by the following procedure is referred to as Reference Example 7 .
More specifically, in the water replenishment of the fuel cell in step S41, nitrogen gas having a temperature of about 70 ° C. and a relative humidity of about 100% was supplied over 30 minutes. Here, the flow rate of nitrogen gas was adjusted so that the flow rate per unit reaction area of MEA was 4 [ml / min].
In the gas replacement of the fuel cell in step S42, the reaction gas was supplied to the anode channel and the cathode channel for 3 minutes. Here, the flow rate of the reaction gas was adjusted so that the flow rate per unit reaction area of MEA was 8 [ml / min].
In preparation for power generation operation and hydrogen pump operation in step S43, the voltage of the stabilized power supply is set to 1 [V], the shutoff valves of the cathode side introduction pipe and the anode side discharge pipe are opened, and the reaction gas is supplied to the anode flow path. Then, an oxidant gas was supplied to the cathode channel. Here, the flow rate of the reaction gas is adjusted so that the flow rate per unit reaction area of MEA is 14 [ml / min], and the flow rate of the oxidant gas is 33 [ml per unit reaction area of MEA. / Min].
In the power generation operation in step S44, the current of the electronic load device is changed from 0 [A / cm ² ] to 1 [A / cm ² ] while the voltage application by the stabilized power source and the supply of the reaction gas and the oxidant gas are continued. Until it was raised at a rate of 100 [mA / cm ² / sec], this state was maintained for 1 minute.
In the hydrogen pump operation in step S45, first, the shut-off valve of the cathode side introduction pipe was closed, and the power generation reaction in the fuel cell was stopped to bring the stack voltage to 0 [V] or lower, and this state was maintained for 1 minute. Thereafter, the current of the electronic load was decreased from 1 [A / cm ² ] to 0 [A / cm ² ] at a rate of 100 [mA / cm ² / sec], and this state was maintained for 1 minute.
In addition, the number of repetitions of step S46 was 72. Therefore, the total aging time of the fuel cell of Reference Example 7 is about 240 minutes.

In addition, when the same experiment as the experiment 8 in the second reference mode was performed on the fuel cell of the reference example 7 as described above, the hydrogen pump operation or the power generation operation was performed only once as in the reference example 6. As a result, it was verified that it can be activated efficiently in a short time compared to the activated one or the combination of the hydrogen pump operation and the power generation operation performed once.

Claims (2)

A method for activating a solid polymer fuel cell comprising an anode electrode and a cathode electrode, and a solid polymer membrane disposed between the anode electrode and the cathode electrode,
In a state where oxygen is not supplied to the cathode electrode but hydrogen is supplied to the anode electrode, an external power supply generates a voltage that varies within a predetermined width between the cathode electrode and the anode electrode, with the cathode electrode being positive. The process to be applied is defined as the first process,
The shutoff valve of the gas introduction pipe that does not supply oxygen to the cathode electrode and communicates with the cathode electrode is closed, and current is supplied from the cathode electrode to the anode electrode by an external power source in a state where hydrogen is supplied to the anode electrode. By flowing , hydrogen ions generated at the anode electrode are moved to the cathode electrode side through the solid polymer membrane, and a process of receiving electrons at the cathode electrode and turning them into hydrogen again is defined as a second process,
A method for activating a polymer electrolyte fuel cell, wherein the combination of the first step and the second step is repeated twice or more. A method for activating a polymer electrolyte fuel cell comprising an anode electrode and a cathode electrode, and a polymer electrolyte membrane disposed between the anode electrode and the cathode electrode,
In a state where oxygen is not supplied to the cathode electrode but hydrogen is supplied to the anode electrode, an external power supply generates a voltage that varies within a predetermined width between the cathode electrode and the anode electrode, with the cathode electrode being positive. The process to be applied is defined as the first process,
The step of changing the output current within a predetermined current width while supplying hydrogen and oxygen to the anode and the cathode, respectively, and generating power in the fuel cell, is defined as a third step,
A method for activating a polymer electrolyte fuel cell, wherein the combination of the first step and the third step is repeated twice or more.