Membrane electrode activation method, device and equipment and fuel cell

Abstract

The invention discloses a membrane electrode activation method, device and equipment and a fuel cell, accumulative calculation is carried out according to an ECSA integral calculation formula in a preset time period, the active area of a to-be-detected membrane electrode activated by cyclic voltammetry is judged to be larger than a preset active area, after an electrochemical workstation is dismounted, the to-be-detected membrane electrode is connected with a load, and the to-be-detected membrane electrode is activated. And after the cathode gas of the membrane electrode to be detected is switched into air and the anode gas is switched into hydrogen, performing high-frequency variable-current activation until the battery voltage is stabilized at a preset voltage value under the preset current density. According to the method, the cyclic voltammetry is firstly adopted for activation, impurities on active sites of a catalyst layer covering the surface of the membrane electrode can be removed, humidification gas is accelerated to enter the catalyst layer, the active area of the membrane electrode to be detected is larger than the preset active area, then high-frequency variable-current activation is carried out, and an electron and proton mass transfer channel can be rapidly constructed; therefore, efficient establishment of a reaction three-phase interface is realized, the activation time is shortened, and the activation efficiency is improved.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a method, apparatus, device, and fuel cell for activating a membrane electrode assembly. Background Technology

[0002] A fuel cell is an electrochemical device that directly converts the chemical energy of externally supplied fuel and oxidant into electrical energy (direct current) and generates heat and reaction products. The membrane electrode assembly (MEA) is a component consisting of an electrolyte membrane and gas diffusion electrodes or a catalyst-coated membrane positioned on either side of the MEA, along with gas diffusion layers on either side, assembled through a specific process. Newly assembled fuel cells typically require MEA activation before normal operation. This activation aims to effectively build the proton, electron, and gas transport network within the fuel cell, thereby maximizing MEA performance. Hydrophobic MEA catalyst layers have low oxygen content, poor hydrophilicity, and low porosity, resulting in significant resistance to proton and gas transport and making activation difficult.

[0003] Existing methods typically employ a single, forced output current for activation, which results in long activation times and low efficiency. For superhydrophobic membrane electrodes and functionalized membrane electrodes with ordered structures, opening proton transport channels is relatively difficult. Activation using a single variable current or cyclic voltammetry method cannot effectively establish humidity and electron, gas, and proton transport channels within the catalyst layer. Summary of the Invention

[0004] This invention provides a method, apparatus, device, and fuel cell for activating membrane electrodes, which can shorten the activation time of membrane electrodes and improve activation efficiency.

[0005] In a first aspect, embodiments of the present invention provide a method for activating a membrane electrode, comprising: The membrane electrode under test is tested to obtain the initial active area of ​​the membrane electrode under test; After connecting the electrode to be tested to an electrochemical workstation, it was activated by cyclic voltammetry. The active area of ​​the membrane electrode under test after activation by cyclic voltammetry is obtained by performing cumulative calculation according to the ECSA integral calculation formula within a preset time period. When it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to a load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen. High-frequency variable current activation is then performed until the battery voltage stabilizes at the preset voltage value under the preset current density.

[0006] Optionally, before testing the membrane electrode under test to obtain its initial active area, the method further includes: After cutting the membrane electrode under test to the target size that matches the test fixture, the single-cell performance test is performed on the fuel cell connection test bench assembled with the membrane electrode under test. Nitrogen gas is introduced into the cathode and anode of the membrane electrode under test, and the test conditions are set under these conditions.

[0007] Optionally, the minimum voltage range for activation using the cyclic voltammetry method is 0.05~0.2V, and the maximum voltage range is 0.9~1.2V.

[0008] Optionally, after switching the cathode gas of the test membrane electrode to air and the anode gas to hydrogen, the high-frequency variable current activation of the test membrane electrode includes: The current is increased at a preset rising and falling speed for the membrane electrode under test. When the voltage of the membrane electrode under test is detected to be less than or equal to a first preset voltage value and stabilized for a first preset time, the current is decreased at the preset rising and falling speed for the membrane electrode under test. When the voltage of the membrane electrode under test is detected to be equal to the open circuit voltage value, it is recorded as the first high-frequency variable current activation. The first preset voltage value ranges from 0.2 to 0.35 V, and the open-circuit voltage value ranges from 0.92 to 0.96 V.

[0009] Optionally, the high-frequency variable current activation of the test membrane electrode further includes: The high-frequency variable current activation is performed cyclically a preset number of times.

[0010] Secondly, embodiments of the present invention also provide an activation device for a membrane electrode, comprising: The initial active area acquisition module is used to test the membrane electrode under test and acquire the initial active area of ​​the membrane electrode under test. The cyclic voltammetry activation module is used to activate the test membrane electrode by cyclic voltammetry after connecting it to an electrochemical workstation. The initial active area acquisition module is also used to perform cumulative calculations according to the ECSA integral calculation formula within a preset time period to obtain the active area of ​​the membrane electrode under test after activation by cyclic voltammetry. The high-frequency variable current activation module is used to perform high-frequency variable current activation when it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to the load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen, until the battery voltage stabilizes at the preset voltage value under the preset current density.

[0011] Optional, also includes: The single-cell performance testing module is used to perform single-cell performance testing on the fuel cell connection test bench assembled with the membrane electrode under test after cutting the membrane electrode under test into a target size that matches the test fixture. The test condition setting module is used to introduce nitrogen gas into the cathode and anode of the membrane electrode under test and set the test conditions under these conditions.

[0012] Thirdly, embodiments of the present invention also provide an activation device for a membrane electrode, the activation device comprising: At least one processor; and a memory communicatively connected to said at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor to enable the at least one processor to perform the activation method of the membrane electrode described in the first aspect.

[0013] Fourthly, embodiments of the present invention also provide a fuel cell, wherein the membrane electrode of the fuel cell is activated using the membrane electrode activation method described in the first aspect.

[0014] Optionally, the membrane electrode of the fuel cell includes a hydrophobic membrane electrode.

[0015] This invention provides a method, apparatus, device, and fuel cell for activating a membrane electrode assembly (MEA). The method includes testing the MEA under test and simultaneously obtaining its initial active area; connecting the MEA to an electrochemical workstation and activating it using cyclic voltammetry; calculating the active area of ​​the MEA after cyclic voltammetry activation using the ECSA integral formula over a preset time period; when the active area of ​​the MEA after cyclic voltammetry activation is determined to be greater than a preset active area, and the electrochemical workstation is removed, connecting the MEA to a load, and switching the cathode gas to air and the anode gas to hydrogen, followed by high-frequency variable current activation until the battery voltage stabilizes at a preset current density. This invention first uses cyclic voltammetry for activation, which removes impurities covering the active sites of the catalyst layer on the MEA surface and accelerates the entry of humidifying gas into the interior of the catalyst layer, making the active area of ​​the MEA greater than the preset active area. Then, high-frequency variable current activation is performed, which can quickly build electron and proton mass transfer channels, thereby achieving efficient establishment of the three-phase reaction interface, shortening the activation time, and improving the activation efficiency.

[0016] It should be understood that the description in this section is not intended to identify key or essential features of the embodiments of the present invention, nor is it intended to limit the scope of the invention. Other features of the invention will become readily apparent from the following description. Attached Figure Description

[0017] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0018] Figure 1 This is a flowchart of an activation method for a membrane electrode provided in an embodiment of the present invention; Figure 2 This is a flowchart of another membrane electrode activation method provided in an embodiment of the present invention; Figure 3 This is a performance curve of a fuel cell provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of an activation device for a membrane electrode provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of another membrane electrode activation device provided in an embodiment of the present invention; Figure 6 This is a schematic diagram of the structure of an activation device for a membrane electrode provided in an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0020] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate so that the embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion; for example, a process, method, system, product, or apparatus that comprises a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or apparatus.

[0021] The hydrophobic membrane electrode catalytic layer of a fuel cell exhibits excessive hydrophobicity, primarily due to the following reasons: Poor hydrophilicity: Ionomers struggle to form a uniform film on the catalyst surface, resulting in an incomplete proton conduction network and the "deactivation" of most catalyst sites due to their inability to access protons. Low porosity: Narrow gas transport channels hinder the reach of reactant gases to the catalyst sites. Low surface oxygen content: The limited number of functional groups on the carbon support surface affects not only hydrophilicity but also the binding strength with ionomers or catalysts. These three factors combined lead to an extremely limited effective "three-phase reaction interface." In electrochemical tests, this manifests as a very small charge amount for hydrogen adsorption / desorption, resulting in a very low calculated electrochemical active surface area. This invention provides a method, apparatus, device, and fuel cell for activating a membrane electrode, which can break this closed state caused by excessive hydrophobicity and construct an efficient three-phase transport pathway within the catalyst layer, as detailed below: Figure 1 This is a flowchart of a membrane electrode activation method provided by an embodiment of the present invention. This embodiment is applicable to the activation of membrane electrodes. The method can be executed by a membrane electrode activation device, which can be implemented in hardware and / or software. (Reference) Figure 1 The method includes the following steps: S110. Test the membrane electrode under test to obtain the initial active area of ​​the membrane electrode under test.

[0022] Understandably, the activation process significantly alters the performance of the membrane electrode. Testing before activation is equivalent to recording the performance of the membrane electrode in its original state. Different types of membrane electrodes have different initial active areas. Testing the membrane electrode under test before activation and obtaining its initial active area provides a unique and quantifiable benchmark for subsequent evaluation of the activation effect.

[0023] S120. After connecting the electrode to be tested to the electrochemical workstation, activation is performed using cyclic voltammetry.

[0024] It should be noted that cyclic voltammetry is a testing method that linearly changes the potential applied to the working electrode between a high potential and a low potential at a certain rate of voltage rise or fall, recording the current or current density on the working electrode at each potential to obtain the corresponding "potential ~ current / current density" curve. The purpose of activating the membrane electrode under test using cyclic voltammetry is to remove impurities such as oxides from the catalyst layer surface, increasing the electrochemical active area of ​​the catalyst layer; simultaneously, it removes hydrophobic organic impurities from the surface, enhances the humidity control of the membrane electrode, and increases the hydrophilicity of the catalyst layer.

[0025] S130. Accumulate the calculation according to the ECSA integral calculation formula within the preset time period to obtain the active area of ​​the membrane electrode under test after activation by cyclic voltammetry.

[0026] It should be noted that the electrochemical active surface area (ECSA) is cumulatively calculated using the integral formula within a preset time period. This allows for real-time or intermittent calculation of the ECSA during activation, monitoring its growth curve over time (number of cycles). This enables precise determination of when activation reaches a plateau (i.e., complete activation) and quantifies the efficiency of different activation stages. After cyclic voltammetry activation, the increase in active area varies for different types of membrane electrodes, and after a certain number of cycles, the increase in active area remains constant. Therefore, based on the active area of ​​the membrane electrode under test after cyclic voltammetry activation, the cyclic voltammetry activation can be terminated when the increase in active area remains constant.

[0027] S140. When it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to the load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen. Then, high-frequency variable current activation is performed until the battery voltage stabilizes at the preset voltage value under the preset current density.

[0028] The preset active area can be set according to the model of the membrane electrode under test. It can be set to the area where the increase in active area of ​​the membrane electrode remains constant after a certain number of cycles of cyclic voltammetry activation. The preset voltage value can be selected to select the voltage value at a specific electrical density point. Theoretically, the preset voltage value will no longer change when activation is complete. The preset voltage value varies for different models of membrane electrodes, and can be set according to the model of the membrane electrode under test.

[0029] It should be noted that the transport channels for electrons, protons, gases, and water within the membrane electrode assembly (MEA) are intricate and complex. Activation methods that efficiently establish the three-phase interface within the MEA are extremely difficult to implement. Simply combining conventional activation testing methods is insufficient for effectively activating functionalized MEAs. From a microscopic perspective, chemical reactions follow a specific time sequence; therefore, activation reactions must also adhere to this principle to efficiently improve reaction efficiency. In fuel cells, the porous structure formed by the catalyst layer and binder, with the catalyst layer being the core of the MEA, serves as both the site of electrochemical reactions and a transport channel for protons, electrons, reactant gases, and water. Therefore, accelerating the establishment of the three-phase interface through rapid activation can shorten the activation time of hydrophobic MEAs while also improving their performance. Understandably, cyclic voltammetry activation removes impurities covering the active sites of the catalyst layer on the MEA surface, accelerates the entry of humidifying gas into the catalyst layer, and increases the active area of ​​the MEA to be tested to exceed the preset active area. The purpose of subsequent high-frequency variable current activation is to rapidly open the mass transfer channels of the catalyst layer, increasing proton transfer efficiency and improving the porosity of the catalyst layer.

[0030] This invention provides an electrochemical activation method for hydrophobic membrane electrodes. First, cyclic voltammetry is used for activation, which can remove impurities covering the active sites of the catalyst layer on the surface of the membrane electrode and accelerate the entry of humidifying gas into the interior of the catalyst layer, so that the active area of ​​the membrane electrode under test is greater than the preset active area. Then, high-frequency variable current activation is performed, which can quickly build electron and proton mass transfer channels, thereby achieving efficient establishment of the three-phase interface of the reaction, shortening the activation time, and improving the activation efficiency.

[0031] Figure 2 This is a flowchart of another membrane electrode activation method provided in an embodiment of the present invention, see reference. Figure 2 The method includes the following steps: S210. After cutting the membrane electrode under test to the target size that matches the test fixture, perform single-cell performance testing on the fuel cell connection test bench assembled with the membrane electrode under test.

[0032] Understandably, the target size can be freely set according to the actual situation. Specifically, the target size can be... .

[0033] S220. Nitrogen gas is introduced into the cathode and anode of the membrane electrode under test, and the test conditions are set under these conditions.

[0034] It is understandable that while purging and heating the fuel cell by introducing humidifying nitrogen gas into the cathode and anode of the membrane electrode under test (MEA), the MEA itself is pre-humidified to open the proton transport channels. Test conditions can include pressure, flow rate, and temperature. These conditions can be freely set according to actual conditions. For example, the pressure at both the cathode and anode of the MEA can be 70 kPa, and the temperature of the fuel cell can be... Once the fuel cell temperature and inlet pressure reach the target values, connect the electrochemical workstation. At this point, switch the anode gas to hydrogen, and set the flow rates of both the cathode and anode gases at the membrane electrode to 0.5 L / min before proceeding with the activation treatment.

[0035] S230. Test the membrane electrode under test to obtain the initial active area of ​​the membrane electrode under test.

[0036] S240. After connecting the electrode to be tested to the electrochemical workstation, activate it using cyclic voltammetry.

[0037] S250. Accumulate the calculation according to the ECSA integral calculation formula within the preset time period to obtain the active area of ​​the membrane electrode under test after activation by cyclic voltammetry.

[0038] S260. When it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to the load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen. Then, high-frequency variable current activation is performed until the battery voltage stabilizes at the preset voltage value under the preset current density.

[0039] It should be noted that the anode gas flow rate can range from 1.0 L / min to 2.0 L / min, and the cathode gas flow rate can range from 2.5 L / min to 5.0 L / min. When encountering membrane electrodes that are difficult to activate, the gas flow rates of the anode and cathode can be appropriately increased to accelerate the reaction process.

[0040] Optionally, based on the above embodiments, the minimum voltage range for activation using cyclic voltammetry is 0.05~0.2V, and the maximum voltage range is 0.9~1.2V.

[0041] Understandably, the minimum voltage for activation using cyclic voltammetry can be freely set within the range of 0.05~0.2V, and the maximum voltage can be freely set within the range of 0.9~1.2V. The number of activation cycles can be set according to actual needs. For conventional membrane electrodes, the cyclic voltammetry stage voltage is set to 0.10~1.0V for activation. Functionalized, superhydrophobic, and high-durability membrane electrodes are generally more difficult to activate, requiring a wider voltage range to ensure sufficient activation. A cyclic voltammetry stage voltage of 0.05~1.2V is used. A voltage range of 0.05~1.2V for activation using cyclic voltammetry has the following advantages: 0.05V is slightly higher than the hydrogen evolution potential, avoiding interference from large amounts of hydrogen evolution on the electrode surface (such as bubble adhesion). 1.2V provides a sufficiently high potential to oxidize the platinum surface to form a controllable oxide film while preventing bulk oxidation or dissolution of platinum. This effectively cleans and oxidizes the surface while ensuring the long-term stability of the electrode, representing the optimal window for balancing activation and electrode protection. In other embodiments, a voltage range of 0.05–0.9V allows for gentle activation. This is suitable for routine maintenance or when the electrode is relatively clean, focusing on stabilizing the surface rather than deep cleaning. A voltage range of 0.1–1.0V provides good cleaning performance and safety, and is often used for testing specific reactions directly after activation. A voltage range of 0.2–1.2V focuses on the redox behavior of Pt, avoiding interference from hydrogen in the activation process.

[0042] Optionally, based on the above embodiments, after switching the cathode gas of the membrane electrode under test to air and the anode gas to hydrogen, the high-frequency variable current activation of the membrane electrode under test includes: performing current increase processing on the membrane electrode under test according to a preset rise and fall rate; when the voltage of the membrane electrode under test is detected to be less than or equal to a first preset voltage value and stabilized for a first preset time, performing current decrease processing on the membrane electrode under test according to a preset rise and fall rate; when the voltage of the membrane electrode under test is detected to be equal to the open circuit voltage value, it is recorded as the first high-frequency variable current activation. The first preset voltage value ranges from 0.2 to 0.35 V, and the open-circuit voltage value ranges from 0.92 to 0.96 V.

[0043] Optionally, the high-frequency variable current activation of the membrane electrode under test may also include: cyclically performing high-frequency variable current activation a preset number of times.

[0044] The preset lifting speed, first preset time, and preset number of times can be freely set according to actual conditions. The preset lifting speed can range from 10 to 40 A / min, the first preset time can be freely set, and the preset number of times can range from 1 to 15. To protect the test bench, different test benches have different minimum voltage values ​​during the second stage of high-frequency variable current activation. Therefore, the first preset voltage value needs to be set according to actual conditions. The voltage of conventional membrane electrodes is from 0.35V to open circuit voltage (OCV), with a maximum voltage of about 0.96V. Functionalized, superhydrophobic, and high-durability membrane electrodes are usually more difficult to activate, and the voltage range needs to be increased to ensure a sufficient activation process. In this case, the voltage is from 0.2V to open circuit voltage (OCV).

[0045] For example, when the open-circuit voltage OCV of one membrane electrode under test is 0.96V, the current can be increased at a rate of 20A / min. When the detected voltage value reaches 0.2V, the current is then decreased at the same rate. When the open-circuit voltage is reached, the operation ends, which is recorded as the first high-frequency variable current activation. This cycle is repeated 4 times. When the open-circuit voltage OCV of another membrane electrode is 0.95V, the current can be increased at a rate of 10A / min. When the detected voltage value reaches 0.35V, the current is then decreased at the same rate. When the open-circuit voltage is reached, the operation ends, which is recorded as the first high-frequency variable current activation. This cycle is repeated 4 times.

[0046] In one embodiment, the hydrophobic membrane electrode to be tested is cut into... The size and assembly of a single cell were determined, and the cell was connected to a single-cell test bench. Nitrogen gas was first introduced into the anode and cathode of the hydrophobic membrane electrode under test to set the anode and cathode pressures to 70 kPa, with the cell temperature at 75°C. Once the cell temperature and inlet pressure reached the target values, the electrochemical workstation was connected. At this point, the cathode gas was switched to air, and the anode gas to hydrogen. The anode and cathode gas flow rates were set to 0.5 / 0.5 L / min, and activation was then performed. Accelerated activation was conducted using cyclic voltammetry with a voltage range of 0.05~1.2V and 50 activation cycles, without applying a load current to the test bench. The electrochemical workstation was then removed, a load was connected, and the cathode gas was switched to air. The anode and cathode gas flow rates were set to 1.2 / 4.8 L / min. When the open-circuit voltage exceeded 0.96V, high-frequency variable current activation was performed at a rate of 30 A / min. The voltage was reduced to approximately 0.35V and stabilized for 10 minutes. Then, a current reduction process was performed, and this cycle was repeated multiple times until activation was complete. Figure 3 This is a performance curve diagram of a fuel cell provided in an embodiment of the present invention, for reference. Figure 3After activation using the membrane electrode assembly provided in this embodiment of the invention, the voltage-current curve shifts upwards overall. Under the same output current, the battery's operating voltage increases significantly, reducing losses. The power density curve also shifts upwards overall, indicating a significant increase in the battery's maximum power density. The curve expands to the right, meaning the concentration polarization region only appears at higher current densities, enhancing the fuel cell's ultimate output capability.

[0047] The activation method of this invention, with optimized key parameters, can achieve the same or even better activation effect in 1 hour as traditional methods take 6-8 hours. This greatly improves the activation efficiency of a single cell, provides a guarantee for the batch verification of membrane electrodes, and perfectly meets the urgent need for rapid and standardized activation in the batch verification of membrane electrodes.

[0048] In another embodiment, the voltage range is changed to 0.1~1.0V, while other parameters remain the same. Figure 3 In the corresponding embodiment, the total activation time is approximately 55 minutes (due to a slightly narrower voltage window and a slightly shorter scan time). Post-activation performance: maximum power density. , The voltage at that point is 0.67V. Performance and... Figure 3 The corresponding embodiments are similar, indicating that the 0.1~1.0V window also has a good activation effect, but the slightly narrower window may be slightly less effective for adsorbing species on deeply cleaned surfaces.

[0049] In another embodiment, the number of activation cycles is increased to 100 cycles, while other parameters remain the same. Figure 3 In the corresponding embodiment, the total activation time is approximately 75 minutes. Post-activation performance: maximum power density. , The voltage at that point is 0.685V. Performance and... Figure 3 The corresponding implementation is comparable or slightly better, but it takes longer and has a lower cost-effectiveness. It is suitable for scenarios with extremely high initial performance requirements.

[0050] In another embodiment, during variable current activation, the current ramp-up / ramp rate is increased to 60 A / min, and the cycle is repeated 5 times (to compensate for the reduced settling time under rapid scanning). Other parameters are the same. Figure 3 In the corresponding embodiment, the total activation time is approximately 50 minutes. Post-activation performance: maximum power density. , The voltage at the point is 0.66V. The total time consumption is further reduced, but the performance is slightly degraded, indicating that excessively rapid current changes may not be conducive to a sufficient balance of hydrothermal distribution inside the membrane electrode.

[0051] In a prior art activation method, cyclic voltammetry is not used for activation. Air is introduced at the cathode of the hydrophobic film electrode under test, and hydrogen is introduced at the anode. The current is then directly applied from a low current density (e.g., ...). Begin by gradually increasing the current in a stepwise manner (e.g., 5 A / min), stabilizing at each current point for up to 30 minutes until a high current density region is reached, followed by several small-amplitude cycles. Activation typically requires 6-8 hours or more. Post-activation performance: maximum power density. , The voltage at this point is 0.63V. The performance is significantly lower than that of the embodiments of this invention, and the processing time is extremely long.

[0052] In a prior art activation method, only cyclic voltammetry is used for activation, without high-frequency variable current activation. The parameter settings for cyclic voltammetry activation are the same as in this invention. Figure 3 In the corresponding embodiment, high-frequency variable current activation is not performed after completion; performance testing is conducted directly. The total activation time is approximately 20 minutes. The maximum power density after activation is... , The voltage at the point is 0.60V. Initial performance is acceptable, but the curves show poor performance in the high current density region, with the power curve dropping prematurely. This indicates that the proton conductors inside the membrane electrode are not sufficiently wetted and activated, resulting in severe concentration polarization.

[0053] In another embodiment, the voltage range for the cyclic voltammetry method is 0.05~0.9V, and other parameters are the same. Figure 3 In the corresponding embodiment, the total activation time is approximately 55 minutes. Post-activation performance: maximum power density. , The voltage at the point is 0.65V. Its performance is superior to existing activation methods, but significantly lower. Figure 3 Corresponding examples. Analysis suggests that the upper limit potential of 0.9V is insufficient to completely form / reduce the Pt oxide layer, resulting in the electrochemical active area on the electrode surface not being maximized and incomplete initial activation.

[0054] In another embodiment, during variable current activation, the current ramp-up / down rate is reduced to 10 A / min, and this is repeated three times. The total activation time is approximately 90 minutes, with other parameters remaining the same. Figure 3 Corresponding embodiment, post-activation performance: maximum power density , The voltage at that point is 0.675V. The final performance is similar to... Figure 3 The corresponding embodiment is similar, but the activation time increased by 50%. This indicates that although a slow current change can achieve similar endpoint performance, it severely sacrifices activation efficiency and does not meet the goal of rapid activation. Without load activation, the membrane electrode cannot be sufficiently wetted, resulting in poor high-current performance.

[0055] Therefore, a voltage range of 0.05–1.2V is superior to 0.1–1.0V and 0.05–0.9V, maximizing the electrochemical active area while protecting the electrode. A variable current rate of 30 A / min achieves the best balance between efficiency and effectiveness.

[0056] In summary, the embodiments of this invention first employ an electrochemical cyclic voltammetry method for rapid activation of the membrane electrode, which electrochemically polishes the surface of the catalytic layer of the membrane electrode, effectively removing organic matter and oxides covering the surface of the active components, increasing the electrochemical active area of ​​the active components, and improving the performance of the membrane electrode. After the active area of ​​the membrane electrode under test exceeds the preset active area, a high-frequency variable current method is used to accelerate the current rise and fall, rapidly stimulating the activation response of the membrane electrode, accelerating the construction of mass transfer channels in the catalytic layer, and quickly forming a three-phase interface, thereby improving the performance of the membrane electrode. This method can significantly shorten the activation time of the membrane electrode, accelerate the construction of proton, electron, and gas molecule transport channels inside the catalytic layer, reduce fuel consumption during the activation process, and is suitable for the activation of membrane electrodes in batches, improving production efficiency.

[0057] Figure 4 This is a schematic diagram of the structure of an activation device for a membrane electrode provided in an embodiment of the present invention. (Refer to...) Figure 4 The device includes: an initial active area acquisition module 410, used to test the membrane electrode under test and acquire the initial active area of ​​the membrane electrode under test; a cyclic voltammetry activation module 420, used to activate the membrane electrode under test by cyclic voltammetry after connecting it to an electrochemical workstation; the initial active area acquisition module 410 is also used to perform cumulative calculations according to the ECSA integral calculation formula within a preset time period to acquire the active area of ​​the membrane electrode under test after activation by cyclic voltammetry; and a high-frequency variable current activation module 430, used to perform high-frequency variable current activation when it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is disconnected, the membrane electrode under test is connected to a load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen, until the battery voltage stabilizes at the preset voltage value under the preset current density.

[0058] Figure 5 This is a schematic diagram of another membrane electrode activation device provided in an embodiment of the present invention. Optionally, based on the above embodiments, refer to... Figure 5 The device also includes: a single-cell performance testing module 510, used to cut the membrane electrode under test to a target size that matches the test fixture, and then perform single-cell performance testing on the fuel cell connection test bench assembled with the membrane electrode under test; and a test condition setting module 520, used to introduce nitrogen gas into the cathode and anode of the membrane electrode under test, and set the test conditions under these conditions.

[0059] The membrane electrode activation device provided in the embodiments of the present invention can execute the membrane electrode activation method provided in any embodiment of the present invention, and has the corresponding functional modules and beneficial effects of the method. For the contents not described in detail in the embodiments of the present invention, please refer to the membrane electrode activation method provided in the above embodiments.

[0060] Figure 6 This is a schematic diagram of the structure of an activation device for a membrane electrode provided in an embodiment of the present invention. (Refer to...) Figure 6 The membrane electrode activation device 10 includes at least one processor 11 and a memory, such as a read-only memory (ROM) 12 or a random access memory (RAM) 13, communicatively connected to the at least one processor 11. The memory stores computer programs executable by the at least one processor. The processor 11 can perform various appropriate actions and processes based on the computer program stored in the ROM 12 or loaded from storage unit 18 into the RAM 13. The RAM 13 can also store various programs and data required for the operation of the membrane electrode activation device 10. The processor 11, ROM 12, and RAM 13 are interconnected via a bus 14. An input / output (I / O) interface 15 is also connected to the bus 14.

[0061] Multiple components in the membrane electrode activation device 10 are connected to the I / O interface 15, including: an input unit 16, such as a keyboard, mouse, etc.; an output unit 17, such as various types of displays, speakers, etc.; a storage unit 18, such as a disk, optical disk, etc.; and a communication unit 19, such as a network card, modem, wireless transceiver, etc. The communication unit 19 allows the membrane electrode activation device 10 to exchange information / data with other devices through computer networks such as the Internet and / or various telecommunications networks.

[0062] Processor 11 can be a variety of general-purpose and / or special-purpose processing components with processing and computing capabilities. Some examples of processor 11 include, but are not limited to, a central processing unit (CPU), a graphics processing unit (GPU), various special-purpose artificial intelligence (AI) computing chips, various processors running machine learning model algorithms, a digital signal processor (DSP), and any suitable processor, controller, microcontroller, etc. Processor 11 performs the various methods and processes described above, such as the activation method of the membrane electrode.

[0063] This invention also provides a fuel cell, wherein the membrane electrode of the fuel cell is activated using the membrane electrode activation method provided in the above embodiments.

[0064] The fuel cell provided in this embodiment of the invention uses the membrane electrode activation method provided in the above embodiment to activate the membrane electrode of the fuel cell, and therefore has the same beneficial effects. For the contents not described in detail in this embodiment of the invention, please refer to the membrane electrode activation method provided in the above embodiment.

[0065] Optionally, based on the above embodiments, the membrane electrode of the fuel cell includes a superhydrophobic membrane electrode.

[0066] It should be understood that the various forms of processes shown above can be used, with steps reordered, added, or deleted. For example, the steps described in this invention can be executed in parallel, sequentially, or in different orders, as long as the desired result of the technical solution of this invention can be achieved, and this is not limited herein.

[0067] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A method for activating a membrane electrode, characterized in that, include: The membrane electrode under test is tested to obtain the initial active area of ​​the membrane electrode under test; After connecting the electrode to be tested to an electrochemical workstation, it was activated by cyclic voltammetry. The active area of ​​the membrane electrode under test after activation by cyclic voltammetry is obtained by performing cumulative calculation according to the ECSA integral calculation formula within a preset time period. When it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to a load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen. High-frequency variable current activation is then performed until the battery voltage stabilizes at the preset voltage value under the preset current density.

2. The activation method for the membrane electrode according to claim 1, characterized in that, Before testing the membrane electrode under test and obtaining its initial active area, the method further includes: After cutting the membrane electrode under test to the target size that matches the test fixture, the single-cell performance test is performed on the fuel cell connection test bench assembled with the membrane electrode under test. Nitrogen gas is introduced into the cathode and anode of the membrane electrode under test, and the test conditions are set under these conditions.

3. The activation method for the membrane electrode according to claim 1, characterized in that, The minimum voltage range for activation using the cyclic voltammetry method is 0.05~0.2V, and the maximum voltage range is 0.9~1.2V.

4. The activation method for the membrane electrode according to claim 1, characterized in that, After switching the cathode gas to air and the anode gas to hydrogen for the membrane electrode under test, the high-frequency variable current activation of the membrane electrode under test includes: The current is increased at a preset rising and falling speed for the membrane electrode under test. When the voltage of the membrane electrode under test is detected to be less than or equal to a first preset voltage value and stabilized for a first preset time, the current is decreased at the preset rising and falling speed for the membrane electrode under test. When the voltage of the membrane electrode under test is detected to be equal to the open circuit voltage value, it is recorded as the first high-frequency variable current activation. The first preset voltage value ranges from 0.2 to 0.35V, and the open-circuit voltage value ranges from 0.92 to 0.96V.

5. The activation method for the membrane electrode according to claim 4, characterized in that, The high-frequency variable current activation of the test membrane electrode also includes: The high-frequency variable current activation is performed cyclically a preset number of times.

6. An activation device for a membrane electrode, characterized in that, include: The initial active area acquisition module is used to test the membrane electrode under test and acquire the initial active area of ​​the membrane electrode under test. The cyclic voltammetry activation module is used to activate the test membrane electrode by cyclic voltammetry after connecting it to an electrochemical workstation. The initial active area acquisition module is also used to perform cumulative calculations according to the ECSA integral calculation formula within a preset time period to obtain the active area of ​​the membrane electrode under test after activation by cyclic voltammetry. The high-frequency variable current activation module is used to perform high-frequency variable current activation when it is determined that the active area of ​​the membrane electrode under test after activation by cyclic voltammetry is greater than the preset active area, and the electrochemical workstation is removed, the membrane electrode under test is connected to the load, and the cathode gas of the membrane electrode under test is switched to air and the anode gas is switched to hydrogen, until the battery voltage stabilizes at the preset voltage value under the preset current density.

7. The activation apparatus for the membrane electrode according to claim 6, characterized in that, Also includes: The single-cell performance testing module is used to perform single-cell performance testing on the fuel cell connection test bench assembled with the membrane electrode under test after cutting the membrane electrode under test into a target size that matches the test fixture. The test condition setting module is used to introduce nitrogen gas into the cathode and anode of the membrane electrode under test, and set the test conditions under these conditions.

8. An activation device for a membrane electrode, characterized in that, The activation device for the membrane electrode includes: At least one processor; and a memory communicatively connected to said at least one processor; wherein, The memory stores a computer program that can be executed by the at least one processor, the computer program being executed by the at least one processor to enable the at least one processor to perform the activation method of the membrane electrode according to any one of claims 1 to 5.

9. A fuel cell, characterized in that, The membrane electrode of the fuel cell is activated using the membrane electrode activation method according to any one of claims 1 to 5.

10. The fuel cell according to claim 9, characterized in that, The membrane electrode assembly of the fuel cell includes a hydrophobic membrane electrode assembly.

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