Activation method for proton exchange membrane fuel cell

Abstract

Disclosed is an activation method for a proton exchange membrane fuel cell, relating to the technical field of fuel cells. The method comprises the following steps: (1) introducing nitrogen to perform purging; (2) performing heating, introducing hydrogen into a hydrogen chamber of a proton exchange membrane fuel cell stack, introducing air into an air chamber, and maintaining an open circuit state; (3) performing constant current discharge: applying a constant current to the proton exchange membrane fuel cell stack, introducing hydrogen into the hydrogen chamber of the proton exchange membrane fuel cell stack, introducing nitrogen into the air chamber, and maintaining same for 1-15 min, and then switching the nitrogen to air and maintaining same for 1-5 min; (4) repeating the operation of step (3) 1-5 times; and (5) performing constant current discharge again. The activation method of the present invention is simple, efficient, time-saving, and can effectively improve discharge performance.

Description

An activation method for a proton exchange membrane fuel cell Technical Field

[0001] This invention relates to the field of fuel cell technology, and more specifically to an activation method for a proton exchange membrane fuel cell. Background Technology

[0002] A proton exchange membrane fuel cell (PEMFC) is a power generation device that directly converts chemical energy into electrical energy through an electrochemical reaction of hydrogen and oxygen. It has broad market prospects in transportation, electronics, defense, and stationary power plants. The discharge performance of a PEMFC stack primarily depends on the performance of its membrane electrode assembly (MEA). To achieve optimal discharge performance, the PEMFC stack needs to be activated. Therefore, newly assembled PEMFC stacks require a suitable activation process to achieve optimal discharge performance. Activation essentially involves MEA activation, which generally includes humidifying the proton exchange membrane, establishing water, proton, electron, and gas channels within the MEA, optimizing the electrode structure, and increasing the exposure of activation sites on the Pt catalyst particles. Discharge activation is the most effective method for PEMFC stack activation and is the primary approach used by domestic companies. Currently, high-power PEMFC stacks are mainly activated by constant current or constant voltage discharge. However, these two activation methods take several hours or even more than ten hours, which seriously affects the efficiency of stack production and testing, requires a large amount of hydrogen, and increases the cost of PEMFC stacks.

[0003] Patent CN117096385A discloses a rapid activation method for PEM fuel cells, including pre-activation using an immersion solution prepared with deionized water, acid, and isopropanol, airtightness checks, and online current-controlled activation steps. Before stack assembly, the MEA needs to be immersed in acidic and isopropanol solutions, followed by repeated rinsing with deionized water, increasing the difficulty of stack assembly, resulting in low production efficiency and failing to meet the safety requirements for mass industrial production. In the online current-controlled activation process of this patent, hydrogen is directly introduced into the hydrogen chamber, which easily forms a hydrogen-air interface with the air in the hydrogen chamber, causing performance degradation of the MEA and affecting the performance of the PEM fuel cell.

[0004] Patent CN113097538A discloses a rapid activation method for fuel cells. First, nitrogen is used to purge the anode and cathode pipelines to fully remove gases and prevent irreversible damage caused by a hydrogen-vacancy interface at the anode. Then, humidified fuel and oxidant are introduced to maintain a high open-circuit voltage, removing impurities introduced during the membrane electrode assembly (MEA) fabrication process on the cathode catalyst surface. Constant current loading and high-current operation allow the generated water to rapidly humidify the MEA. Through high-current de-voltage and boost-voltage cycles, the average single-cell voltage of the stack is cyclically adjusted between high and low potentials, thereby reducing the oxide layer on the cathode catalyst surface and rapidly forming stable electron, ion, gas, and liquid transport channels, achieving rapid activation of the fuel cell stack. Although this patent avoids irreversible damage at the anode due to a hydrogen-vacancy interface by purging the anode and cathode pipelines with nitrogen, the subsequent activation process is similar to conventional activation, requiring a relatively long activation time. Furthermore, this patent does not address the treatment of the catalyst layer.

[0005] Patent CN115064732A discloses an activation method for a proton exchange membrane fuel cell. The activation method includes the following steps: (1) Nitrogen replacement: the fuel cell stack is placed on a test platform, and the hydrogen chamber and air chamber of the test platform are replaced with wet nitrogen; (2) Heating of the fuel cell stack; (3) Voltage increase: the hydrogen chamber is replaced with wet hydrogen, and the air chamber is replaced with wet air; (4) Secondary nitrogen replacement: the air chamber is replaced with wet nitrogen again, while the hydrogen chamber remains filled with hydrogen, and the stack is left to stand; (5) Constant current discharge cycle: the hydrogen in the hydrogen chamber is adjusted, the air chamber is replaced with wet air, the current is increased from the initial current to the preset current, and then decreased back to the initial current, and the load-deload operation is repeated until activation is complete. The activation method provided by this patent involves more than 40 discharge cycles, taking nearly 2 hours, which increases the production cost of the PEMFC stack.

[0006] Methods for activating PEMFC stacks under harsh conditions, such as high-temperature treatment in boiling water or steam before MEA assembly or CO oxidation stripping, do not meet the safety requirements for large-scale industrial production. Furthermore, reported activation methods suffer from drawbacks such as complex processes, long activation times, and high hydrogen consumption. Therefore, only by developing PEMFC stack activation methods that are simple, quick, and consume less hydrogen can the demands of large-scale industrial production be met.

[0007] The current activation method easily forms a hydrogen-air interface on the anode side, which generates a high potential and causes severe corrosion of the carbon support. The corrosion damage at the hydrogen-air interface mainly occurs on the cathode side. Corrosion of the carbon support leads to Pt detachment, three-phase interface disruption, and other phenomena, ultimately resulting in a severe degradation of fuel cell performance. This degradation is far more severe than the lifespan reduction caused by high potential in actual fuel cell operation. Simultaneously, the increased cathode potential also leads to carbon corrosion, which damages the conductors in the cathode and forces the reconstruction of electron pathways, further increasing the cathode's ohmic resistance and contact resistance. Furthermore, carbon corrosion causes Pt particle detachment, reducing the catalytic active area and thus decreasing the discharge performance of the PEMFC.

[0008] During MEA preparation and PEMFC stack assembly, Pt particles on the catalyst layer surface are easily oxidized to form PtO2 due to prolonged exposure to air, which reduces the active sites of the catalyst and thus reduces the catalytic efficiency of the catalyst. As a result, even after long-term activation, the PEMFC stack cannot achieve optimal discharge performance. Summary of the Invention

[0009] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an activation method for proton exchange membrane fuel cells. The activation method of this invention is simple, efficient and quick, and can effectively improve discharge performance.

[0010] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0011] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0012] (1) Nitrogen gas was introduced into the anode and the anode of the proton exchange membrane fuel cell stack for purging;

[0013] (2) Heat up the proton exchange membrane fuel cell stack, introduce hydrogen into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air into the cavity, and keep it in an open circuit state.

[0014] (3) Perform constant current discharge: apply the load current to 99-165A at the first load rate and maintain it for 1-15 minutes; apply the load current to 330-396A at the second load rate and maintain it for 1-15 minutes; reduce the load to open circuit.

[0015] A constant current is applied to the proton exchange membrane fuel cell stack, hydrogen is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen is introduced into the cavity, and the process is maintained for 1 to 15 minutes.

[0016] Disconnect the DC power supply, then switch the nitrogen in the cavity to air and keep it ventilated for 1 to 5 minutes;

[0017] (4) Repeat step (3) 1 to 5 times;

[0018] (5) Perform constant current discharge again: apply the load current to 155-175A at the third load rate and hold for 1-15 minutes; apply the load current to 480-520A at the fourth load rate and hold for 1-15 minutes; apply the load current to 580-620A at the fifth load rate and hold for 1-15 minutes; reduce the load to open circuit to complete activation.

[0019] This invention innovatively first purges the anode and cathode of the proton exchange membrane fuel cell stack with nitrogen, effectively humidifying the MEA and removing impurities introduced onto the MEA surface during PEMFC stack assembly. This effectively avoids the formation of a hydrogen-air interface and reduces the risk of MEA performance degradation. Next, the temperature is increased, hydrogen is introduced into the hydrogen chamber, and air is introduced into the air chamber, maintaining an open circuit state. This further improves the wetting effect of the MEA and enhances its activation performance. Furthermore, changes in the open-circuit voltage can quickly diagnose the risk of hydrogen-air leakage in the MEA. Finally, a constant current discharge is applied to the proton exchange membrane fuel cell stack, which is beneficial for the exchange of water, protons, and electrons within the MEA. The process involves establishing a gas channel; introducing hydrogen into the hydrogen chamber of the proton exchange membrane fuel cell stack and nitrogen into the air chamber, creating an air-deficient state at the cathode. Hydrogen protons from the anode combine with electrons at the cathode to generate hydrogen, which facilitates the reduction reaction of the oxide layer on the cathode, increasing the number of active sites for the catalytic reaction. This also optimizes the electrode structure and improves catalyst efficiency, significantly enhancing the discharge performance of the PEMFC. Finally, a constant current discharge is performed in three stages, gradually increasing the current until it is reduced to an open circuit, effectively improving the activation effect and bringing the PEM stack to its optimal performance. Furthermore, this invention has a short activation time, completing the process within 50 minutes, effectively shortening the activation time.

[0020] As a preferred embodiment of the present invention, the relative humidity of the nitrogen gas in step (1) is 60-100%, and the purging time is 1-5 min.

[0021] In a preferred embodiment of the present invention, the relative humidity of the hydrogen gas in step (2) is 60-100%; and / or

[0022] The relative humidity of the air in step (2) is 60-100%.

[0023] As a preferred embodiment of the present invention, the temperature in step (2) is raised to 60-80°C.

[0024] As a preferred embodiment of the present invention, the open circuit voltage in step (2) is ≥0.95V, and the open circuit state is maintained for 1 to 10 minutes.

[0025] In a preferred embodiment of the present invention, the first loading rate in step (3) is 0.1 to 10 A / s; and / or

[0026] In step (3), the second loading rate is 1 to 20 A / s.

[0027] In a preferred embodiment of the present invention, the second load rate is greater than the first load rate.

[0028] In a preferred embodiment of the present invention, the first loading rate is 0.1 to 1 A / s.

[0029] In a preferred embodiment of the present invention, the second loading rate is 1.5 to 8 A / s.

[0030] In a preferred embodiment of the present invention, the second load rate / the first load rate = 8 to 15.

[0031] In particular, controlling the first loading rate to be 0.1–1 A / s and the second loading rate to be 1.5–2 A / s, and controlling the ratio of the two to be 8–15, is beneficial to the establishment of water, proton, electron, and gas channels inside the MEA, which facilitates the subsequent improvement of activation sites and discharge performance.

[0032] In a preferred embodiment of the present invention, the constant current is 30 to 150 A.

[0033] In a preferred embodiment of the present invention, the relative humidity of the hydrogen gas in step (3) is 60-100%; and / or

[0034] The relative humidity of the nitrogen gas in step (3) is 60-100%; and / or

[0035] The relative humidity of the air in step (3) is 60-100%.

[0036] As a preferred embodiment of the present invention, the third load rate, the fourth load rate, and the fifth load rate in step (5) are each independently 1 to 20 A / s;

[0037] The unloading rate mentioned in step (5) is 20-30 A / s.

[0038] The beneficial effects of this invention are as follows: First, the anode and cathode of the proton exchange membrane fuel cell stack are purged with nitrogen, which effectively humidifies the MEA and removes impurities introduced onto the MEA surface during the assembly of the PEMFC stack, effectively avoiding the formation of a hydrogen-air interface and reducing the risk of MEA performance degradation. Then, the temperature is increased, hydrogen is introduced into the hydrogen chamber, and air is introduced into the air chamber, maintaining an open circuit state, further improving the wetting effect of the MEA and enhancing its activation performance. Furthermore, changes in the open-circuit voltage can quickly diagnose whether there is a risk of hydrogen-air leakage in the MEA. Finally, constant current discharge is applied to the proton exchange membrane fuel cell stack, which is beneficial for the internal water and gas balance of the MEA. The invention establishes channels for protons, electrons, and gases; hydrogen is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, while nitrogen is introduced into the cavity, creating an air-deficient state at the cathode. Hydrogen protons conducted from the anode combine with electrons at the cathode to generate hydrogen, which facilitates the reduction reaction of the oxide layer at the cathode, increasing the number of active sites for the catalytic reaction. Simultaneously, the electrode structure is optimized, improving catalyst efficiency and significantly enhancing the discharge performance of the PEMFC. Finally, a constant current discharge is performed again, in three stages, gradually increasing the current until it is reduced to an open circuit, effectively improving the activation effect and bringing the PEM stack to its optimal performance. Furthermore, the activation time of this invention is short, completed within 50 minutes, effectively shortening the activation time. Detailed Implementation

[0039] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions in the embodiments of this application will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0040] In this application, the technical features described in an open-ended manner include both closed technical solutions consisting of the listed features and open technical solutions that include the listed features.

[0041] In this application, numerical ranges are referred to as continuous unless otherwise specified, and include the minimum and maximum values ​​of the range, as well as every value between the minimum and maximum values. Furthermore, when the range refers to integers, it includes every integer between the minimum and maximum values ​​of the range. Additionally, when multiple ranges are provided to describe a feature or characteristic, the ranges may be merged. In other words, unless otherwise specified, all ranges disclosed herein should be understood to include any and all subranges to which they are incorporated.

[0042] In this application, there are no particular restrictions on the specific dispersion and mixing methods.

[0043] Unless otherwise specified, all components, raw materials, or instruments used in the embodiments and comparative examples of this invention are commercially available, and the same type of components and raw materials are used in each parallel experiment.

[0044] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0045] The following embodiments are provided to facilitate understanding of the invention. These embodiments are not intended to limit the scope of the claims.

[0046] Example 1

[0047] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0048] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0049] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0050] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0051] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0052] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0053] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0054] (4) Repeat step (3) once;

[0055] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0056] Example 2

[0057] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0058] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0059] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0060] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0061] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0062] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0063] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0064] (4) Repeat step (3) twice;

[0065] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0066] Example 3

[0067] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0068] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0069] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0070] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0071] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0072] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0073] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0074] (4) Repeat step (3) 3 times;

[0075] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0076] Example 4

[0077] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0078] A reaction area of ​​300 cm² was used. 2An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0079] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0080] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0081] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.1A / s and hold for 3 minutes; apply load current to 330A at a load rate of 1.5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0082] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0083] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0084] (4) Repeat step (3) twice;

[0085] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0086] Example 5

[0087] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0088] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0089] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0090] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0091] (3) Perform constant current discharge: apply load current to 99A at a load rate of 1A / s and hold for 3min; apply load current to 330A at a load rate of 8A / s and hold for 3min; reduce load to open circuit at a load rate of 10A / s.

[0092] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0093] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0094] (4) Repeat step (3) twice;

[0095] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0096] Example 6

[0097] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0098] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0099] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0100] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0101] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0102] A constant current of 120A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0103] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0104] (4) Repeat step (3) twice;

[0105] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0106] Comparative Example 1

[0107] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0108] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0109] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0110] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0111] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0112] (4) Repeat step (3) twice;

[0113] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0114] Comparative Example 2

[0115] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0116] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0117] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0118] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0119] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0120] (4) Repeat step (3) 10 times;

[0121] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0122] Comparative Example 3

[0123] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0124] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0125] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0126] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0127] (3) Perform constant current discharge: apply load current to 99A at a load rate of 0.5A / s and hold for 3 minutes; apply load current to 330A at a load rate of 5A / s and hold for 3 minutes; reduce load to open circuit at a load rate of 10A / s.

[0128] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0129] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0130] (4) Repeat step (3) twice;

[0131] (5) Perform constant current discharge again: apply the load current to 495A at a load rate of 10A / s and hold for 6 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0132] Comparative Example 4

[0133] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0134] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0135] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0136] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0137] (3) Perform constant current discharge: apply load current to 99A at a load rate of 10A / s and hold for 3min; apply load current to 330A at a load rate of 25A / s and hold for 3min; reduce load to open circuit at a load rate of 10A / s.

[0138] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0139] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0140] (4) Repeat step (3) twice;

[0141] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0142] Comparative Example 5

[0143] An activation method for a proton exchange membrane fuel cell includes the following steps:

[0144] A reaction area of ​​300 cm² was used. 2 An experiment was conducted on a proton exchange membrane fuel cell stack consisting of 200 proton exchange membrane fuel cells. The stack was connected to the test bench, and no abnormalities were found in its airtightness.

[0145] (1) Purge the anode and the anode of the proton exchange membrane fuel cell stack with nitrogen gas at a relative humidity of 100% for 3 minutes;

[0146] (2) Heat the proton exchange membrane fuel cell stack to 70°C, introduce hydrogen with a relative humidity of 100% into the hydrogen chamber of the proton exchange membrane fuel cell stack, introduce air with a relative humidity of 100% into the cavity, keep it in an open circuit state for 3 minutes, and the average open circuit voltage is ≥0.95V.

[0147] (3) Perform constant current discharge: apply load current to 99A at a load rate of 15A / s and hold for 3min; apply load current to 330A at a load rate of 20A / s and hold for 3min; reduce load to open circuit at a load rate of 10A / s.

[0148] A constant current of 60A is applied to the proton exchange membrane fuel cell stack using a DC power supply. Hydrogen gas with a relative humidity of 80% is introduced into the hydrogen chamber of the proton exchange membrane fuel cell stack, and nitrogen gas with a relative humidity of 80% is introduced into the cavity. After maintaining this for 3 minutes, the DC power supply is disconnected.

[0149] Then replace the nitrogen in the cavity with air with a relative humidity of 80% and keep it ventilated for 3 minutes;

[0150] (4) Repeat step (3) twice;

[0151] (5) Perform constant current discharge again: apply the load current to 165A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 495A at a load rate of 10A / s and hold for 2 minutes; apply the load current to 594A at a load rate of 10A / s and hold for 2 minutes; reduce the load to open circuit at a load rate of 20A / s to complete the activation.

[0152] Test case

[0153] After activation using the methods described in the above embodiments and comparative examples, the PEMFC stacks underwent discharge performance tests. Loading was performed at a loading rate of 20 A / s, with operating conditions including a stack temperature of 70°C, a gas metering ratio of 1.4 / 1.8 for the anode and cathode, a relative humidity of 60% / 40% for the anode and cathode, and gas pressures of 150 / 120 kPa for the anode and cathode, respectively, at a current density of 1.8 A / cm². 2 The average voltage under these conditions is shown in Table 1.

[0154] Table 1

[0155] As can be seen from Table 1, the activation method of the present invention is simple, efficient and quick, and can effectively improve discharge performance.

[0156] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can be made to the technical solutions of the present invention without departing from the essence and scope of the technical solutions of the present invention.

Claims

1. A method of activating a proton exchange membrane fuel cell, characterized by, The method comprises the following steps: (1) purging the anode and the anode of a proton exchange membrane fuel cell stack with nitrogen; (2) heating the proton exchange membrane fuel cell stack, and supplying hydrogen to the hydrogen cavity of the proton exchange membrane fuel cell stack and air to the air cavity, and maintaining an open circuit state; (3) performing constant current discharge: loading current at a first loading rate to 99-165 A, and maintaining for 1-15 min; loading current at a second loading rate to 330-396 A, and maintaining for 1-15 min; and unloading to an open circuit; applying a constant current to the proton exchange membrane fuel cell stack, supplying hydrogen to the hydrogen cavity of the proton exchange membrane fuel cell stack and nitrogen to the air cavity, and maintaining for 1-15 min; disconnecting the direct current power supply, and switching the nitrogen in the air cavity to air and maintaining ventilation for 1-5 min; (4) repeating the operation in step (3) for 1-5 times; (5) performing constant current discharge again: loading current at a third loading rate to 155-175 A, and maintaining for 1-15 min; loading current at a fourth loading rate to 480-520 A, and maintaining for 1-15 min; and loading current at a fifth loading rate to 580-620 A, and maintaining for 1-15 min; unloading to an open circuit, and completing activation. The relative humidity of the nitrogen in step (1) is 60-100%, and the purging time is 1-5 min.

2. The method of activating a proton exchange membrane fuel cell of claim 1, wherein, The relative humidity of the hydrogen in step (2) is 60-100%; and / or 3. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The relative humidity of the air in step (2) is 60-100%. The temperature in step (2) is heated to 60-80 °C.

4. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The open circuit voltage in step (2) is ≥0.95 V, and the time for maintaining an open circuit state is 1-10 min.

5. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The first loading rate in step (3) is 0.1-10 A / s; and / or 6. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The second loading rate in step (3) is 1-20 A / s. The second loading rate / first loading rate = 8-15.

7. The method of claim 6, wherein the activation is performed at a temperature of 80°C to 100°C. The constant current is 30-150 A.

8. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The relative humidity of the hydrogen in step (3) is 60-100%; and / or 9. The method of claim 1, wherein the proton exchange membrane fuel cell is activated by, The relative humidity of the nitrogen in step (3) is 60-100%; and / or The relative humidity of the air in step (3) is 60-100%. The third loading rate, fourth loading rate and fifth loading rate in step (5) are each independently 1-20 A / s.

10. The method of activating a proton exchange membrane fuel cell of claim 1, wherein, The unloading rate in step (5) is 20-30 A / s. ​

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