Method for reactivating fuel cell

Abstract

The invention belongs to the technical field of fuel cells, and particularly relates to a fuel cell reactivation method which comprises the following steps: (1) pulling and loading a to-be-recovered fuel cell to a rated voltage through fuel cell pulling and loading equipment; (2) after the fuel cell stably operates under the rated voltage, reducing the duty ratio of the fan of the fuel cell until the voltage of the fuel cell is stable again; and (3) increasing the duty ratio of the fan of the fuel cell to the duty ratio of the fan corresponding to the rated voltage in the step (1), and after the voltage is stabilized again, reducing the load and pulling the load equipment to stop. The fuel cell reactivation method has the beneficial effects that the catalytic activity of a fuel cell catalyst can be effectively recovered, a damaged electrode can be repaired, and the output power and the cruising ability of the fuel cell can be enhanced, so that the service life of the fuel cell can be remarkably prolonged; the frequency of replacing the battery is reduced, the resource waste is reduced, the carbon emission is reduced, the concept of sustainable development is met, and the cost is saved for a user.

Description

Technical Field

[0001] The invention belongs to the technical field of fuel cells, and in particular relates to a method for reactivating a fuel cell. Background Art

[0002] Compared with traditional lithium battery-assisted bicycles, hydrogen two-wheeled vehicles equipped with air-cooled fuel cells have the advantages of environmental protection and energy saving, no need for charging, long endurance, and high safety. However, in actual use, the performance of air-cooled fuel cells will decline to a certain extent after being placed for a period of time, which undoubtedly affects its long-term stable operation. Therefore, it is urgent to restore the performance of air-cooled fuel cells in hydrogen two-wheeled vehicles and extend the service life of two-wheeled vehicles.

[0003] In the prior art, CN 106654324 A introduces a method for restoring the performance of an air-cooled fuel cell, which restores the performance of the fuel cell by cutting off the air supply. Since the fan of an air-cooled fuel cell has the functions of supplying air and assisting in heat dissipation, cutting off the air supply means that the fan stops running. Since the fuel cell storage compartment in a two-wheeled vehicle is small and stores other system components at the same time, the fan needs to assist in heat dissipation during operation to avoid safety hazards caused by excessive temperature, so this method of cutting off the air supply is not feasible. Therefore, it is necessary to conduct in-depth research and improvement on restoring the performance of air-cooled fuel cells. Summary of the invention

[0004] The embodiment of the present application provides a method for reactivating a fuel cell, which aims to solve the problem of performance degradation of an air-cooled fuel cell after being left for a period of time.

[0005] The present invention provides a method for reactivating a fuel cell, comprising the following steps:

[0006] (1) Loading the fuel cell to be restored to its rated voltage by a fuel cell loading device;

[0007] (2) After the fuel cell operates stably at the rated voltage, reducing the fan duty cycle of the fuel cell until the voltage thereof stabilizes again;

[0008] (3) increasing the fan duty cycle of the fuel cell to the fan duty cycle corresponding to the rated voltage in step (1), and after the voltage stabilizes again, reducing the load until the load-carrying equipment shuts down.

[0009] The advantages and technical effects of the fuel cell reactivation method of the embodiment of the present application are as follows: 1. In the embodiment of the present application, the fuel cell is first loaded to the rated voltage and then the fan duty cycle is reduced (the fan duty cycle refers to the ratio of the time that the fan of the fuel cell is in the on state during the working cycle to the total working cycle). Reducing the fan duty cycle will cause the voltage of the fuel cell to rise. Since the air supply is reduced due to the reduction of the fan duty cycle, the voltage of the fuel cell will show a downward trend after a short rise and then tend to stabilize. The air-cooled fuel cell is placed for a long time, causing the platinum (Pt) catalyst in the air-cooled fuel cell to be oxidized, and reducing the fan duty cycle will reduce the air flow in the fuel cell. Because there is not enough oxygen to react with hydrogen ions and platinum electrons, the Pt oxide undergoes a reverse reaction and is reduced to Pt, restoring the catalyst activity, thereby achieving performance recovery, i.e. activation. At the same time, due to the reduction of the fan duty cycle, the water produced by the reaction will not be easy to dissipate, so that the membrane electrode is moistened, thereby achieving the purpose of restoring the performance of the fuel cell. After the fan duty cycle of the fuel cell is reduced until the voltage is stable, the fan duty cycle of the fuel cell is increased again to stop the insufficient air supply, thereby further ensuring the recovery of the fuel cell and extending its service life; 2. The method of the embodiment of the present application can effectively restore the catalytic activity of the fuel cell catalyst, repair damaged electrodes, and enhance the output power and endurance of the battery, thereby significantly extending its service life; it reduces the frequency of battery replacement, reduces resource waste and reduces carbon emissions, conforms to the concept of sustainable development, and saves costs for users; 3. The method of the embodiment of the present application will conduct a comprehensive inspection and repair of the battery during the reactivation process to eliminate potential safety hazards, ensure that the battery operates in the best condition, and improve the safety of use.

[0010] According to some embodiments of the fuel cell reactivation method described in the present application, in step (1), the fuel cell is loaded at a temperature of 20-30°C.

[0011] According to some embodiments of the fuel cell reactivation method described in the present application, the relative humidity of the fuel cell is 40% rh-99% rh.

[0012] According to some embodiments of the fuel cell reactivation method described in the present application, in step (2), the rate of decrease of the fan duty cycle is to decrease the fan duty cycle of the fuel cell by 1%-3% every 3 minutes.

[0013] According to some embodiments of the fuel cell reactivation method of the present application, the fan duty cycle of the fuel cell is reduced while ensuring that the temperature of the fuel cell is ≤52°C.

[0014] According to some embodiments of the fuel cell reactivation method described in the present application, in step (2), the voltage of the fuel cell when it stabilizes again is ±0.2V of its rated voltage.

[0015] According to some embodiments of the fuel cell reactivation method described in the present application, in step (2), the fuel cell is operated continuously for 10-30 minutes after the voltage of the fuel cell stabilizes again.

[0016] According to some embodiments of the fuel cell reactivation method described in the present application, in step (2), the fuel cell is operated continuously for 15-25 minutes after the voltage of the fuel cell stabilizes again.

[0017] According to some embodiments of the fuel cell reactivation method described in the present application, in step (3), the rate of increasing the fan duty cycle of the fuel cell is to increase the fan duty cycle of the fuel cell by 1%-3% every 3 minutes.

[0018] According to some embodiments of the fuel cell reactivation method described in the present application, in step (3), the voltage of the fuel cell when it stabilizes again is ±0.2V of its rated voltage.

[0019] According to some embodiments of the fuel cell reactivation method described in the present application, in step (3), after the voltage of the fuel cell is stabilized again, the fuel cell is continuously operated for 1-3 minutes, for example, 1 minute, 2 minutes, 3 minutes, and then the load is reduced.

[0020] According to some embodiments of the method for reactivating a fuel cell of the present application, in step (3), the frequency of the load reduction operation is reduced by 0.08-0.12 A / cm per second. 2 .

[0021] According to some embodiments of the method for reactivating a fuel cell described in the present application, a nitrogen purging step is also included, and the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling equipment is shut down.

[0022] According to some embodiments of the fuel cell reactivation method described in the present application, the fuel cell includes an air-cooled fuel cell. DETAILED DESCRIPTION

[0023] Embodiments of the present invention are described in detail below. The embodiments are exemplary and intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0024] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0025] The present invention provides a method for reactivating a fuel cell, comprising the following steps:

[0026] (1) Loading the fuel cell to be restored to its rated voltage by a fuel cell loading device;

[0027] (2) After the fuel cell operates stably at the rated voltage, reducing the fan duty cycle of the fuel cell until the voltage thereof stabilizes again;

[0028] (3) increasing the fan duty cycle of the fuel cell to the fan duty cycle corresponding to the rated voltage in step (1), and after the voltage stabilizes again, reducing the load until the load-carrying equipment shuts down.

[0029] After the load is pulled to the rated voltage, the fan duty cycle is reduced (the fan duty cycle refers to the ratio of the time that the fan of the fuel cell is turned on during the working cycle to the total working cycle). Reducing the fan duty cycle will cause the voltage of the fuel cell to rise. Because the air supply is reduced due to the reduction in the fan duty cycle, the voltage of the fuel cell will show a downward trend after a short rise and then tend to stabilize. The platinum (Pt) catalyst in the air-cooled fuel cell is oxidized due to long-term storage. Reducing the fan duty cycle will reduce the air flow in the fuel cell. Because there is not enough oxygen to react with hydrogen ions and platinum electrons, the Pt oxide undergoes a reverse reaction and is reduced to Pt, restoring the catalyst activity, thereby achieving performance recovery, i.e. activation. At the same time, due to the reduction of the fan duty cycle, the water produced by the reaction is not easy to dissipate, so that the membrane electrode is moistened, thereby achieving the purpose of restoring the performance of the fuel cell. After the fan duty cycle of the fuel cell is reduced to a stable voltage, the fan duty cycle of the fuel cell is increased to stop the insufficient air supply, further ensuring the recovery of the fuel cell and extending its service life.

[0030] In some embodiments, in step (1), the temperature of the fuel cell loading is 20-30°C, for example, 20°C, 25°C, 28°C, 30°C.

[0031] In some embodiments, the relative humidity of the fuel cell load is 40% rh-99% rh, such as 40% rh, 50% rh, 55% rh, 63% rh, 68% rh, 70% rh, 76% rh, 79% rh, 83% rh, 88% rh, 90% rh, 95% rh, 99% rh. Since the drier the membrane electrode of the fuel cell, the greater the internal resistance of the fuel cell, the higher the ambient humidity, the more conducive it is to the operation of the air-cooled fuel cell stack, so the reactivation process is preferably carried out when the ambient humidity is greater than 40% rh.

[0032] In some embodiments, in step (2), the rate of decrease of the fan duty cycle is to decrease the fan duty cycle of the fuel cell by 1%-3% every 3 minutes; for example, 1%, 2%, 3%, etc. Reducing the fan duty cycle will cause a short-term increase in voltage, and the temperature of the fuel cell will rise accordingly. The temperature increase is conducive to the reduction reaction. In addition, reducing the fan duty cycle will reduce the air flow in the fuel cell. Because there is not enough oxygen to react with hydrogen ions and platinum electrons, the Pt oxide undergoes a reverse reaction and is reduced to Pt, restoring the catalyst activity.

[0033] In some embodiments, the fan duty cycle of the fuel cell is reduced while ensuring that the temperature of the fuel cell is ≤52° C., such as 52° C., 50° C., 48° C., 45° C., 40° C., 36° C., 35° C., 30° C. Ensuring that the temperature of the fuel cell is ≤52° C. can prevent the degradation and cracking of the fuel cell stack material due to excessive temperature of the fuel cell stack.

[0034] In some embodiments, in step (2), the voltage of the fuel cell when it stabilizes again is ±0.2V of its rated voltage.

[0035] In some embodiments, in step (2), after the voltage of the fuel cell stabilizes again, the operation is continued for 10-30 minutes, for example, 10 minutes, 15 minutes, 20 minutes, 22 minutes, 25 minutes, 28 minutes, and 30 minutes. In this process, the catalyst oxidized by the long-term storage of the fuel cell will fully undergo a reduction reaction. The Pt catalyst of the air-cooled fuel cell is oxidized due to the long-term storage, and this process will fully cause the oxidized catalyst to undergo a reduction reaction.

[0036] In some embodiments, in step (2), the fuel cell is operated continuously for 15-25 minutes after the voltage of the fuel cell stabilizes again.

[0037] In some embodiments, in step (3), the rate of increasing the fan duty cycle of the fuel cell is to increase the fan duty cycle of the fuel cell by 1%-3% every 3 minutes. Increasing the fan duty cycle is to stop the process of insufficient air supply, further ensure the recovery of the fuel cell, and extend its service life.

[0038] In some embodiments, in step (3), the voltage of the fuel cell when it stabilizes again is the rated voltage ±0.2 V. Since the adjustment of the fan duty cycle will reactivate the fuel cell, the voltage needs to be stabilized again.

[0039] In some embodiments, in step (3), after the voltage of the fuel cell stabilizes again, the fuel cell is continuously operated for 1-3 minutes, for example, 1 minute, 2 minutes, 3 minutes, and then the load is reduced. Continuous operation for 1-3 minutes can ensure that the fuel cell has stable operation time, thereby extending the life of the fuel cell and reducing loss.

[0040] In some embodiments, in step (3), the load reduction frequency is 0.08-0.12A / cm per second. 2 , for example 0.08A / cm 2 , 0.09A / cm 2 , 0.10A / cm 2 , 0.12A / cm 2 .

[0041] In some embodiments, a nitrogen purge step is further included, wherein the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling device is shut down. Nitrogen purge can remove residual hydrogen and excess moisture inside the fuel cell, thereby protecting the battery life and improving safety.

[0042] In some embodiments, the fuel cell comprises an air-cooled fuel cell.

[0043] The technical solution of the present application is described in detail below in conjunction with specific embodiments.

[0044] Example 1

[0045] A method for reactivating a fuel cell comprises the following steps:

[0046] (1) Under the conditions of an ambient temperature of 25°C and a relative humidity of 60% rh, the fuel cell to be restored is calibrated according to standard operating conditions, that is, the fuel cell stack test equipment is used (the fuel cell stack test equipment described in this application was purchased from Ningbo Beit Measurement and Control Technology Co., Ltd., model NBT-PEM-1kW) to load the fuel cell stack to be tested. After the fuel cell stack test equipment is connected to the air-cooled fuel cell stack, the test bench of the fuel cell stack test equipment provides fuel to the fuel cell stack to be tested. The tester changes the various parameter ratios of the stack test equipment (such as gas composition, flow rate, pressure, temperature, etc.) to load the fuel cell to be restored to its rated voltage. After the current stabilizes, the data of various parameters, that is, the standard operating condition data, are collected. The operating condition data of various parameters are shown in Table 1.

[0047] (2) After the fuel cell is stably operating at the rated voltage, the fan duty cycle of the fuel cell is reduced at a rate of 2% every 3 minutes and the temperature of the fuel cell is monitored in real time to ensure that the temperature of the fuel cell does not exceed 52° C. (If it exceeds 52° C., the temperature of the fuel cell is reduced by increasing the fan duty cycle). After the voltage of the fuel cell is stabilized again, the stabilized voltage is ±0.2 V of the rated voltage of the fuel cell (fluctuates around ±0.2 V of the rated voltage) and continues to operate for 20 minutes;

[0048] (3) The fan duty cycle of the fuel cell is increased by 2% every 3 minutes to the fan duty cycle corresponding to the rated voltage in step (1). After the voltage of the fuel cell stabilizes again, the stabilized voltage is ±0.2V of the rated voltage of the fuel cell (fluctuates around ±0.2V of the rated voltage), and the operation is continued for 2 minutes. Then, the fan duty cycle is increased by 0.1A / cm 2 The load is reduced at a decreasing rate until it stops, and the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling equipment stops.

[0049] Table 1

[0050]

[0051] Note: The fan duty cycle is for reference only. The duty cycle is adjusted mainly based on the fuel cell temperature (ensuring that the fuel cell temperature is ≤52°C).

[0052] Calibration: refers to a loading process before reactivation. The data of this loading process is the calibration data. It is used as a reference for the reactivation process data. The calibration data of the loading process is determined by the tester's adjustment of various parameters of the stack test equipment and is not a fixed value. Its ultimate goal is to load the fuel cell to the rated voltage.

[0053] The average single-cell voltage of the fuel cell reactivated in Example 1 was tested by a fuel cell stack testing device. The test results are shown in Table 2.

[0054] Table 2

[0055] <![CDATA[Electric density (A / cm 2 )]]> Average single chip voltage before activation (V) Average single chip voltage after activation (V) 0.05 0.7384 0.7634 0.1 0.692 0.7264 0.15 0.658 0.6984 0.2 0.6272 0.674 0.25 0.6004(rated point) 0.6504 0.3 0.6282 0.35 0.608(rated point)

[0056] Note: The higher the electrical density of the fuel cell at the rated point, the better the fuel cell performance.

[0057] It can be seen from Table 2 that, under the same electrical density, the cell voltage of the fuel cell after activation is higher than the cell voltage of the fuel cell before activation, and the performance of the fuel cell is improved after the reactivation process.

[0058] Example 2

[0059] The difference between Example 2 and Example 1 is that the fuel cell reactivation method described in Example 2 reduces the fan duty cycle of the fuel cell at a decreasing rate of 1% of the fan duty cycle of the fuel cell every 3 minutes.

[0060] The average single-chip voltage of the fuel cell reactivated in Example 2 was tested by a fuel cell stack testing device. The test results are shown in Table 3.

[0061] Table 3

[0062]

[0063] Note: The higher the electrical density of the fuel cell at the rated point, the better the fuel cell performance.

[0064] It can be seen from Table 3 that: under the same electrical density, the single-chip voltage of the fuel cell after activation prepared in Example 2 is higher than the single-chip voltage of the fuel cell before activation, but because the decrease rate of the fuel cell fan duty cycle during the activation process is less than that of Example 1, the performance of the fuel cell obtained by reactivation is inferior to that of the fuel cell obtained by reactivation in Example 1.

[0065] Example 3

[0066] The only difference between Example 3 and Example 1 is that the ambient temperature of the fuel cell reactivation process is different. The ambient temperature of the fuel cell reactivation in Example 3 is 30°C.

[0067] The average single-chip voltage of the fuel cell reactivated in Example 3 was tested by a fuel cell stack testing device. The test results are shown in Table 4.

[0068] Table 4

[0069] <![CDATA[Current density (A / cm 2 )]]> 25℃ Average single chip voltage (V) 30℃ Average single chip voltage (V) Average single chip voltage before activation (V) 0.05 0.7634 0.7564 0.7384 0.1 0.7264 0.7125 0.692 0.15 0.6984 0.6872 0.658 0.2 0.674 0.6653 0.6272 0.25 0.6504 0.6397 0.6004(rated point) 0.3 0.6282 0.6199 0.35 0.608(rated point) 0.6007(rated point)

[0070] Note: The higher the electrical density of the fuel cell at the rated point, the better the fuel cell performance.

[0071] It can be seen from Table 4 that: under the same electrical density, the single-chip voltage of the activated fuel cell prepared in Example 3 is higher than the single-chip voltage of the fuel cell before activation, and compared with the performance of the fuel cell after reactivation in Example 1, under the same other activation conditions, an environment of 25°C is more conducive to the activation of the fuel cell.

[0072] Example 4

[0073] The difference between Example 4 and Example 1 is that the duration of continuous operation after the voltage of the fuel cell stabilizes again is different. The specific operation is as follows:

[0074] A method for reactivating a fuel cell comprises the following steps:

[0075] (1) Under the conditions of an ambient temperature of 25°C and a relative humidity of 60% rh, the fuel cell to be restored is calibrated according to standard operating conditions, that is, the fuel cell stack test equipment is used (the fuel cell stack test equipment described in this application was purchased from Ningbo Beit Measurement and Control Technology Co., Ltd., model NBT-PEM-1kW) to load the fuel cell stack to be tested. After the fuel cell stack test equipment is connected to the air-cooled fuel cell stack, the test bench of the fuel cell stack test equipment provides fuel to the fuel cell stack to be tested. The tester changes the various parameter ratios of the stack test equipment (such as gas composition, flow rate, pressure, temperature, etc.) to load the fuel cell to be restored to its rated voltage. After the current stabilizes, the data of various parameters, i.e., standard operating condition data, are collected. The operating condition data of various parameters are shown in Table 1.

[0076] (2) After the fuel cell is stably operated at the rated voltage, the fan duty cycle of the fuel cell is reduced at a rate of 2% every 3 minutes and the temperature of the fuel cell is monitored in real time to ensure that the temperature of the fuel cell does not exceed 52° C. (If it exceeds 52° C., the temperature of the fuel cell is reduced by increasing the fan duty cycle). After the voltage of the fuel cell is stabilized again, the stabilized voltage is ±0.2 V of the rated voltage of the fuel cell (fluctuates around ±0.2 V of the rated voltage) and the operation is continued for 10 minutes;

[0077] (3) The fan duty cycle of the fuel cell is increased by 2% every 3 minutes to the fan duty cycle corresponding to the rated voltage in step (1). After the voltage of the fuel cell stabilizes again, the stabilized voltage is ±0.2V of the rated voltage of the fuel cell (fluctuates around ±0.2V of the rated voltage), and the operation is continued for 2 minutes. Then, the fan duty cycle is increased by 0.1A / cm 2 The load is reduced at a decreasing rate until it stops, and the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling equipment stops.

[0078] The average single-cell voltage of the fuel cell reactivated in Example 4 was tested by a fuel cell stack testing device. The test results are shown in Table 5.

[0079] Table 5

[0080]

[0081] Note: The higher the electrical density of the fuel cell at the rated point, the better the fuel cell performance.

[0082] It can be seen from Table 5 that: under the same electrical density, the single-chip voltage of the activated fuel cell prepared in Example 4 is higher than the single-chip voltage of the fuel cell before activation, and compared with the performance of the fuel cell after reactivation in Example 1, under the same other activation conditions, after the voltage of the fuel cell stabilizes again, continuous operation for 20 minutes is more conducive to the activation of the fuel cell.

[0083] Example 5

[0084] The only difference between Example 5 and Example 1 is that the relative humidity of the environment during the fuel cell reactivation process is different. The specific operation is as follows:

[0085] A method for reactivating a fuel cell comprises the following steps:

[0086] (1) Under the condition of an ambient temperature of 25°C and a relative humidity of 20% rh, the fuel cell to be restored is calibrated according to the standard operating conditions, that is, the fuel cell stack test equipment (the fuel cell stack test equipment described in this application was purchased from Ningbo Beit Measurement and Control Technology Co., Ltd., model NBT-PEM-1kW) is used to load the fuel cell stack to be tested. After the fuel cell stack test equipment is connected to the air-cooled fuel cell stack, the test bench of the fuel cell stack test equipment provides fuel to the fuel cell stack to be tested. The tester changes the various parameter ratios of the stack test equipment (such as gas composition, flow rate, pressure, temperature, etc.) to load the fuel cell to be restored to its rated voltage. After the current stabilizes, the data of various parameters are collected, that is, the standard operating condition data. The operating condition data of various parameters are shown in Table 1.

[0087] (2) After the fuel cell is stably operating at the rated voltage, the fan duty cycle of the fuel cell is reduced at a rate of 2% every 3 minutes and the temperature of the fuel cell is monitored in real time to ensure that the temperature of the fuel cell does not exceed 52° C. (If it exceeds 52° C., the temperature of the fuel cell is reduced by increasing the fan duty cycle). After the voltage of the fuel cell is stabilized again, the stabilized voltage is ±0.2 V of the rated voltage of the fuel cell (fluctuates around ±0.2 V of the rated voltage) and continues to operate for 20 minutes;

[0088] (3) The fan duty cycle of the fuel cell is increased by 2% every 3 minutes to the fan duty cycle corresponding to the rated voltage in step (1). After the voltage of the fuel cell stabilizes again, the stabilized voltage is ±0.2V of the rated voltage of the fuel cell (fluctuates around ±0.2V of the rated voltage), and the operation is continued for 2 minutes. Then, the fan duty cycle is increased by 0.1A / cm 2 The load is reduced at a decreasing rate until it stops, and the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling equipment stops.

[0089] The average single-cell voltage of the reactivated fuel cell of Example 5 was tested by a fuel cell stack testing device. The test results are shown in Table 6.

[0090] Table 6

[0091] <![CDATA[Current density (A / cm 2 )]]> 60%rh average single chip voltage (V) 20% rh average single chip voltage (V) Average single chip voltage before activation (V) 0.05 0.7634 0.7419 0.7384 0.1 0.7264 0.7057 0.692 0.15 0.6984 0.6742 0.658 0.2 0.6740 0.6531 0.6272 0.25 0.6504 0.6288 0.6004(rated point) 0.3 0.6282 0.6054(rated point) 0.35 0.6080(rated point)

[0092] Note: The higher the electrical density of the fuel cell at the rated point, the better the fuel cell performance.

[0093] It can be seen from Table 6 that the environmental humidity of the loading is a key factor affecting the reactivation effect of the fuel cell. Compared with the performance of the fuel cell after reactivation in Example 1, under the same other activation conditions, an environmental humidity of 60% rh is more conducive to the activation of the fuel cell.

[0094] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A method for reactivating a fuel cell, characterized in that: The following steps are involved: (1) Loading the fuel cell to be restored to its rated voltage by a fuel cell loading device; (2) After the fuel cell operates stably at the rated voltage, reducing the fan duty cycle of the fuel cell until the voltage thereof stabilizes again; (3) increasing the fan duty cycle of the fuel cell to the fan duty cycle corresponding to the rated voltage in step (1), and after the voltage stabilizes again, reducing the load until the load-carrying equipment shuts down.

2. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (1), the temperature of the fuel cell loading is 20-30°C; And / or, the relative humidity of the fuel cell is 40% rh-99% rh.

3. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (2), the rate of decreasing the fan duty cycle is to decrease the fan duty cycle of the fuel cell by 1%-3% every 3 minutes; and / or, reducing the fan duty cycle of the fuel cell while ensuring that the temperature of the fuel cell is ≤52° C.; And / or, in step (2), the voltage of the fuel cell when it stabilizes again is ±0.2V of its rated voltage.

4. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (2), after the voltage of the fuel cell stabilizes again, the fuel cell is operated continuously for 10-30 minutes, preferably 15-25 minutes.

5. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (3), the rate of increasing the duty cycle of the fan of the fuel cell is to increase the duty cycle of the fan of the fuel cell by 1%-3% every 3 minutes.

6. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (3), the voltage of the fuel cell stabilizes again at a voltage of ±0.2 V of its rated voltage.

7. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (3), after the voltage of the fuel cell stabilizes again, the fuel cell is operated continuously for 1-3 minutes and then the load is reduced.

8. The method for reactivating a fuel cell according to claim 1, characterized in that: In step (3), the load reduction frequency is 0.08-0.12A / cm per second. 2 .

9. The method for reactivating a fuel cell according to claim 1, characterized in that: The method further comprises a nitrogen purging step, in which the fuel cell is purged with nitrogen after the load is reduced to the point where the load-pulling device is shut down.

10. The method for reactivating a fuel cell according to any one of claims 1 to 9, characterized in that: The fuel cell includes an air-cooled fuel cell.

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