Controllable construction method for cracks of catalytic layer of fuel cell based on control drying mode

Abstract

The invention relates to a fuel cell catalyst layer crack controllable construction method based on a control drying mode, and belongs to the technical field of fuel cells, the method comprises the following steps: constructing a gas-liquid equilibrium phase diagram of a solvent system used by catalyst slurry, and defining a surface evaporation zone, a bulk phase boiling zone and a rapid vaporization zone; according to the gas-liquid equilibrium phase diagram, catalyst slurry is in a selected drying mode area in the drying process by regulating and controlling the drying temperature, so that a drying mode is regulated and controlled, and the drying mode is selected from one or more of a surface evaporation mode, a volume phase boiling mode and a rapid vaporization mode; and drying the catalyst wet slurry layer in a drying mode to obtain the fuel cell catalyst layer. Compared with the prior art, the method has the advantages that the catalyst slurry composition does not need to be changed, the existing production equipment does not need to be transformed, and the accurate control on the surface crack morphology of the catalyst layer can be realized only by scientifically regulating and controlling the temperature in the drying process.

Description

Technical Field

[0001] This invention relates to the field of fuel cell technology, and in particular to a method for controllable construction of catalyst layer cracks in fuel cells based on a regulated drying mode. Background Technology

[0002] The catalyst layer is the core site of electrochemical reactions in proton exchange membrane fuel cells (PEMFCs), and its microstructure directly affects the cell's catalytic activity, mass transfer efficiency, and overall lifespan. Catalyst layer preparation involves three main steps: preparing catalyst ink, dispersing, and then drying. During drying, solvent evaporation leads to volume shrinkage, often causing internal stress concentration and subsequently surface cracks. Appropriate and well-shaped crack structures enhance the catalyst layer's water management capabilities and reactant gas transport, improving cell performance; however, excessive or unevenly distributed cracks reduce the effective reaction area, causing abnormal local current density distributions and severely limiting cell efficiency and durability. Therefore, achieving active and controllable construction of surface cracks in the catalyst layer is of great significance for optimizing fuel cell performance.

[0003] The main methods for controlling catalyst layer cracks fall into two categories: slurry composition optimization and drying process innovation. Regarding slurry composition, for example, Chinese patent application CN116925290A introduces specific polymers and organometallic stabilizers, utilizing butyl acrylate, platinum-cyclodextrin organometallic compounds, and 1-vinyl-3-ethylimidazolium hexafluorophosphate emulsion polymerization to obtain an organometallic suspension stabilizer, improving slurry dispersion stability and thus inhibiting crack formation. Regarding drying processes, Chinese patent application CN117282634A proposes using a light-heating drying method to achieve rapid and uniform solvent evaporation, thereby reducing crack formation. However, existing methods still have significant limitations: composition control methods often require the introduction of additives, which may alter the chemical environment of the catalyst layer and introduce uncertainties into electrochemical performance; innovation in drying processes often requires major modifications to existing production equipment or the purchase of specialized equipment, resulting in high costs and poor compatibility with mainstream production lines.

[0004] There is an urgent need to develop a method that can precisely control the drying behavior and crack formation of the catalyst layer without changing the slurry composition or relying on complex equipment, so as to make up for the shortcomings of existing technologies and meet the requirements of industrial applications for the consistency of catalyst layer quality and controllability of performance. Summary of the Invention

[0005] The purpose of this invention is to overcome the defects of the prior art by providing a method for controllable construction of cracks in the catalyst layer of a fuel cell based on a controlled drying mode. This method does not require changing the composition of the catalyst slurry or modifying existing production equipment. It can achieve precise control of the crack morphology on the surface of the catalyst layer simply by scientifically controlling the temperature during the drying process.

[0006] The objective of this invention can be achieved through the following technical solutions: The first aspect of this invention provides a method for controllable construction of catalyst layer cracks in a fuel cell based on a regulated drying mode, comprising the following steps: S1. Construct the gas-liquid equilibrium phase diagram of the solvent system used in the catalyst slurry, and define the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone. S2. According to the gas-liquid equilibrium phase diagram, the drying temperature is adjusted so that the catalyst slurry is in the selected drying mode region during the drying process, thereby controlling the drying mode. The drying mode is selected from one or more of the following: surface evaporation mode, bulk boiling mode, and rapid vaporization mode. S3. Dry the wet catalyst slurry layer in dry mode to obtain the fuel cell catalyst layer.

[0007] Furthermore, in step S3, the wet catalyst slurry layer is dried under different drying modes (surface evaporation mode, bulk boiling mode, and rapid vaporization mode) to obtain a fuel cell catalyst layer with different surface cracks.

[0008] Furthermore, in step S3, the catalyst slurry drying process is carried out under the same drying mode, and the drying temperature needs to be dynamically adjusted according to the temperature range of the drying mode.

[0009] Furthermore, the solvent system is a water-alcohol two-component system (water-alcohol systems are commonly used in catalyst slurries).

[0010] Furthermore, the gas-liquid equilibrium phase diagram is obtained by solving the gas-liquid equilibrium equations of the two-component solvent, which include: Its constraints are: In the formula, Represents the degrees of freedom of the gas phase. The number of degrees of freedom representing the liquid phase. Indicates the gas phase composition. The fugacity coefficient represents the gas phase. Indicates pressure, Indicates the liquid phase composition. Represents the activity coefficient. The fugacity coefficient represents saturated steam. Indicates saturated vapor pressure. Represents matter i Partial molar volume, The gas constant is This refers to absolute temperature.

[0011] Furthermore, the bubble point calculation includes the following steps: Input liquid phase composition ,pressure ; Activity coefficients were determined using a liquid-phase thermodynamic model. The fugacity coefficient is calculated using a gas-phase thermodynamic model. calculate; Calculate the saturated vapor pressure using the Antoine equation. ; Iterative adjustment Make satisfied ; Calculate the gas phase composition based on equilibrium conditions. .

[0012] Furthermore, the dew point calculation includes the following steps: S21, Input gas phase composition ,pressure ,make ; S22. Using a liquid-phase thermodynamic model, the activity coefficient is calculated. The fugacity coefficient is calculated using a gas-phase thermodynamic model. calculate; S23. Calculate the saturated vapor pressure according to the Antoine equation. ; S24, Iterative Adjustment Make satisfied ; S25. Calculate the liquid phase composition based on equilibrium conditions. ; S26. After step S25, determine whether convergence has occurred. If so, output the liquid phase composition. Otherwise, return to step S22.

[0013] Furthermore, the area below the bubble point line is defined as the surface evaporation zone.

[0014] Furthermore, the region between the bubble point and the dew point is defined as the bulk boiling zone.

[0015] Furthermore, the area above the dew point is defined as the rapid vaporization zone.

[0016] Furthermore, the surface evaporation zone corresponds to the region below the bubble point line in the gas-liquid equilibrium phase diagram; the bulk boiling zone corresponds to the region between the bubble point line and the dew point line in the gas-liquid equilibrium phase diagram; and the rapid vaporization zone corresponds to the region above the dew point line in the gas-liquid equilibrium phase diagram.

[0017] Furthermore, drying temperature is a key parameter for controlling the drying mode.

[0018] Furthermore, the drying mode is achieved by adjusting the drying temperature, which needs to be set and dynamically adjusted according to the temperature range of the target drying mode.

[0019] Furthermore, when the target drying mode is surface evaporation mode, the drying temperature needs to be constantly controlled at a lower temperature; when the target drying mode is bulk boiling mode, the drying temperature needs to be dynamically changed according to a certain pattern during the drying process; when the target drying mode is rapid vaporization mode, the drying temperature needs to be constantly controlled at a higher temperature.

[0020] Furthermore, the drying pressure is atmospheric pressure or near-atmospheric pressure.

[0021] Furthermore, the drying method is either oven drying or plate drying. The drying mode adjustment is independent of the drying method and instrument; this method can be used for both plate drying and oven drying.

[0022] Furthermore, in the surface evaporation mode, drying results in the formation of a suitable amount of cracks on the surface of the resulting catalyst layer; in the bulk boiling mode, drying results in the formation of dense cracks on the surface of the resulting catalyst layer; and in the rapid vaporization mode, drying results in the formation of no cracks or very few cracks on the surface of the resulting catalyst layer.

[0023] In other words, if a surface with a suitable number of cracks is required, the surface evaporation mode should be selected, and the drying temperature should be kept constant within a low range; if a surface with dense cracks is required, the bulk boiling mode should be selected, and the temperature should be raised from a low value to a high value according to a certain pattern during the drying process; if a surface with no or very few cracks is required, the rapid vaporization mode should be selected, and the drying temperature should be kept constant within a high range.

[0024] Furthermore, the method is applicable to various catalyst slurry systems using water-alcohol as a solvent.

[0025] A second aspect of the present invention provides a fuel cell catalyst layer, which is prepared by the method described above, and the surface crack coverage of the fuel cell catalyst layer can be controllably adjusted according to the drying mode.

[0026] Compared with the prior art, the present invention has the following advantages and beneficial effects: 1. This invention provides a method for controllable construction of catalyst layer cracks in fuel cells based on a regulated drying mode. It has strong compatibility, does not change the original slurry formulation, does not introduce additional additives, and has excellent compatibility with existing catalyst layer production processes and equipment, without requiring additional modification costs.

[0027] 2. This invention provides a method for controllable construction of catalyst layer cracks in fuel cells based on a controlled drying mode. It has high controllability and achieves precise and repeatable control of surface cracks from non-existent to present and from sparse to dense by guiding the selection of drying mode through phase diagram theory. This solves the problem of blind crack control in traditional methods.

[0028] 3. This invention provides a method for controllable construction of catalyst layer cracks in fuel cells based on a controlled drying mode. It is simple to operate, requiring only the setting of the temperature program of conventional drying equipment. The principle is clear, the operation is simple and easy to implement, and it is easy to promote and apply in large-scale production.

[0029] 4. This invention provides a method for controllable construction of catalyst layer cracks in fuel cells based on a controlled drying mode. The method has significant effects. By controlling the single physical process of drying, the microstructure of the catalyst layer can be effectively optimized, providing a new technical approach to improve fuel cell performance. Attached Figure Description

[0030] Figure 1 This is the vapor-liquid equilibrium phase diagram of the water-alcohol solvent system used in the embodiments of the present invention, which is used to define the temperature-composition regions of the three drying modes: surface evaporation, bulk boiling and rapid vaporization. Figure 2 The image shows the surface morphology of the catalyst layer obtained by drying in surface evaporation mode (60°C constant temperature) in Example 1, which shows that the catalyst layer forms uniform and moderate cracks in this mode. Figure 3 The image shows the surface morphology of the catalyst layer obtained by drying in bulk boiling mode (90-100°C programmed temperature rise) in Example 2, which shows that dense cracks are formed on the surface of the catalyst layer under this mode. Figure 4 The image shows the surface morphology of the catalyst layer obtained by drying in the rapid vaporization mode (120°C constant temperature) in Example 3, which shows that the catalyst layer surface is smooth and has no or very few cracks under this mode. Figure 5 A flowchart illustrating the bubble point calculation process; Figure 6 This is a flowchart illustrating the dew point calculation process. Detailed Implementation

[0031] The present invention will now be described in detail with reference to the accompanying drawings and specific embodiments. Component models, material names, connection structures, control methods, algorithms, and other features not explicitly described in this technical solution are considered common technical features disclosed in the prior art.

[0032] This invention provides a method for controllable construction of catalyst layer cracks in fuel cells based on a regulated drying mode, comprising the following steps: S1. Construct the gas-liquid equilibrium phase diagram of the solvent system used in the catalyst slurry, and define the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone. S2. According to the gas-liquid equilibrium phase diagram, the drying temperature is adjusted so that the catalyst slurry is in the selected drying mode region during the drying process, thereby controlling the drying mode. The drying mode is selected from one or more of the following: surface evaporation mode, bulk boiling mode, and rapid vaporization mode. S3. Dry the wet catalyst slurry layer in dry mode to obtain the fuel cell catalyst layer.

[0033] In some embodiments of the present invention, in step S3, the wet slurry layer of the catalyst is dried under different drying modes (surface evaporation mode, bulk boiling mode, and rapid vaporization mode) to obtain a fuel cell catalyst layer with different surface cracks.

[0034] In some embodiments of the present invention, in step S3, the catalyst slurry drying process is carried out under the same drying mode, and the drying temperature needs to be dynamically adjusted according to the temperature range of the drying mode.

[0035] In some embodiments of the present invention, the solvent system is a water-alcohol two-component system (a water-alcohol system is commonly used for catalyst slurries).

[0036] In some embodiments of the present invention, the obtained vapor-liquid equilibrium phase diagram model of the water-alcohol solvent system is as follows: Figure 1 As shown.

[0037] In some embodiments of the present invention, the gas-liquid equilibrium phase diagram is obtained by solving the gas-liquid equilibrium equation of the two-component solvent, wherein the gas-liquid equilibrium equation of the two-component solvent includes: Its constraints are: In the formula, Represents the degrees of freedom of the gas phase. The number of degrees of freedom representing the liquid phase. Indicates the gas phase composition. The fugacity coefficient represents the gas phase. Indicates pressure, Indicates the liquid phase composition. Represents the activity coefficient. The fugacity coefficient represents saturated steam. Indicates saturated vapor pressure. Represents matter i Partial molar volume, The gas constant is This refers to absolute temperature.

[0038] In some embodiments of the present invention, such as Figure 5 As shown, the bubble point calculation includes the following steps: Input liquid phase composition ,pressure ; Activity coefficients were determined using a liquid-phase thermodynamic model. The fugacity coefficient is calculated using a gas-phase thermodynamic model. calculate; Calculate the saturated vapor pressure using the Antoine equation. ; Iterative adjustment Make satisfied ; Calculate the gas phase composition based on equilibrium conditions. .

[0039] In some embodiments of the present invention, such as Figure 6 As shown, dew point calculation includes the following steps: S21, Input gas phase composition ,pressure ,make ; S22. Using a liquid-phase thermodynamic model, the activity coefficient is calculated. The fugacity coefficient is calculated using a gas-phase thermodynamic model. calculate; S23. Calculate the saturated vapor pressure according to the Antoine equation. ; S24, Iterative Adjustment Make satisfied ; S25. Calculate the liquid phase composition based on equilibrium conditions. ; S26. After step S25, determine whether convergence has occurred. If so, output the liquid phase composition. Otherwise, return to step S22.

[0040] In some embodiments of the present invention, the area below the bubble point line is defined as the surface evaporation zone.

[0041] In some embodiments of the present invention, the region between the bubble point and the dew point is defined as the bulk boiling zone.

[0042] In some embodiments of the present invention, the region above the dew point is defined as the rapid vaporization zone.

[0043] In some embodiments of the present invention, the surface evaporation zone corresponds to the region below the bubble point line in the gas-liquid equilibrium phase diagram; the bulk boiling zone corresponds to the region between the bubble point line and the dew point line in the gas-liquid equilibrium phase diagram; and the rapid vaporization zone corresponds to the region above the dew point line in the gas-liquid equilibrium phase diagram.

[0044] In some embodiments of the present invention, drying temperature is a key parameter for achieving drying mode control.

[0045] In some embodiments of the present invention, the drying mode is achieved by adjusting the drying temperature, which needs to be set and dynamically adjusted according to the temperature range of the target drying mode.

[0046] In some embodiments of the present invention, when the target drying mode is surface evaporation mode, the drying temperature needs to be constantly controlled at a lower temperature; when the target drying mode is bulk boiling mode, the drying temperature needs to be dynamically changed according to a certain pattern during the drying process; when the target drying mode is rapid vaporization mode, the drying temperature needs to be constantly controlled at a higher temperature.

[0047] In some embodiments of the present invention, the drying pressure is atmospheric pressure or near-atmospheric pressure.

[0048] In some embodiments of the present invention, the drying method is oven drying or plate drying. The adjustment of the drying mode is independent of the drying method and instrument; this method can be used for both plate drying and oven drying.

[0049] In some embodiments of the present invention, drying in the surface evaporation mode results in the formation of a suitable amount of cracks on the surface of the resulting catalyst layer; drying in the bulk boiling mode results in the formation of dense cracks on the surface of the resulting catalyst layer; and drying in the rapid vaporization mode results in the formation of no cracks or very few cracks on the surface of the resulting catalyst layer.

[0050] In other words, if a surface with a suitable number of cracks is required, the surface evaporation mode should be selected, and the drying temperature should be kept constant within a low range; if a surface with dense cracks is required, the bulk boiling mode should be selected, and the temperature should be raised from a low value to a high value according to a certain pattern during the drying process; if a surface with no or very few cracks is required, the rapid vaporization mode should be selected, and the drying temperature should be kept constant within a high range.

[0051] In some embodiments of the present invention, the method is applicable to various catalyst slurry systems using water-alcohol as a solvent.

[0052] The present invention also provides a fuel cell catalyst layer, which is prepared by the method described above, and the surface crack coverage of the fuel cell catalyst layer can be controllably adjusted according to the drying mode.

[0053] Example 1 The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode provided in this embodiment includes the following steps: S1. Construct the gas-liquid equilibrium phase diagram of the solvent system used in the catalyst slurry. The obtained gas-liquid equilibrium phase diagram model of the water-alcohol solvent system is as follows: Figure 1 As shown, the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone are defined. S2. According to the gas-liquid equilibrium phase diagram, the drying temperature is adjusted to keep the catalyst slurry in the selected drying mode region during the drying process, so as to control the drying mode. S3. Dry the wet catalyst slurry layer in dry mode to obtain the fuel cell catalyst layer.

[0054] In this embodiment, the mass fraction of alcohol is 0.5, and the catalyst slurry components include: Pt / C catalyst (commercially available product), perfluorosulfonic acid polymer solution (DuPont D2020 type), water, and n-propanol.

[0055] In this embodiment, the catalyst slurry coating method involves using a doctor blade to coat the catalyst onto a polytetrafluoroethylene substrate, with a coating thickness of 150 micrometers, to obtain a wet catalyst slurry layer.

[0056] In this embodiment, the drying method is oven drying, the drying mode is surface evaporation mode, the drying temperature is always controlled at 60℃, the drying pressure is 1 atmosphere, and the drying time is 10 minutes.

[0057] In this embodiment, the surface cracks of the catalyst layer were examined using optical microscopy and scanning electron microscopy. 50) combined methods were used to observe the cross-sectional cracks of the catalyst layer using scanning electron microscopy (SEM). 5000) observation.

[0058] This embodiment controls the catalyst layer cracking by setting the drying mode to surface evaporation mode, as follows: Figure 2 As shown.

[0059] In this embodiment, the catalyst layer prepared by the surface evaporation mode forms a uniform and moderately textured crack network.

[0060] Example 2 The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode provided in this embodiment includes the following steps: S1. Construct the gas-liquid equilibrium phase diagram of the solvent system used in the catalyst slurry. The obtained gas-liquid equilibrium phase diagram model of the water-alcohol solvent system is as follows: Figure 1 As shown, the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone are defined. S2. According to the gas-liquid equilibrium phase diagram, the drying temperature is adjusted to keep the catalyst slurry in the selected drying mode region during the drying process, so as to control the drying mode. S3. Dry the wet catalyst slurry layer in dry mode to obtain the fuel cell catalyst layer.

[0061] This embodiment provides information on catalyst layer cracking under controlled drying mode of bulk boiling mode.

[0062] The catalyst slurry, coating method, and parameters in this embodiment are consistent with those in Example 1.

[0063] In this embodiment, the drying method is oven drying, the drying mode is bulk boiling mode, the drying temperature is dynamically controlled at 90-100℃ according to the mass fraction of alcohol in the coating, the drying pressure is 1 atmosphere, and the drying time is 10 minutes.

[0064] In this embodiment, the temperature only needs to rise uniformly from 90°C to 100°C within 10 minutes.

[0065] The crack observation method in this embodiment is the same as that in Embodiment 1.

[0066] In this embodiment, the catalytic layer cracking is controlled by adjusting the drying mode to a bulk boiling mode. Figure 3 As shown.

[0067] In this embodiment, the catalyst layer prepared by the surface evaporation mode formed dense, wide, and deep cracks.

[0068] Example 3 The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode provided in this embodiment includes the following steps: S1. Construct the gas-liquid equilibrium phase diagram of the solvent system used in the catalyst slurry. The obtained gas-liquid equilibrium phase diagram model of the water-alcohol solvent system is as follows: Figure 1 As shown, the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone are defined. S2. According to the gas-liquid equilibrium phase diagram, the drying temperature is adjusted to keep the catalyst slurry in the selected drying mode region during the drying process, so as to control the drying mode. S3. Dry the wet catalyst slurry layer in dry mode to obtain the fuel cell catalyst layer.

[0069] This embodiment provides information on catalyst layer cracking under controlled drying mode of rapid vaporization.

[0070] The catalyst slurry, coating method, and parameters in this embodiment are consistent with those in Examples 1 and 2.

[0071] In this embodiment, the drying method is oven drying, the drying mode is rapid vaporization mode, the drying temperature is always controlled at 120℃, the drying pressure is 1 atmosphere, and the drying time is 10 minutes.

[0072] The crack observation method in this embodiment is the same as that in Embodiments 1 and 2.

[0073] This embodiment controls the catalyst layer cracking situation by setting the drying mode to a rapid vaporization mode, as follows: Figure 4 As shown.

[0074] The catalyst layer prepared by the surface evaporation method in this embodiment has a smooth surface with almost no cracks.

[0075] The above description of the embodiments is provided to enable those skilled in the art to understand and use the invention. It will be apparent to those skilled in the art that various modifications can be made to these embodiments, and the general principles described herein can be applied to other embodiments without inventive effort. Therefore, the present invention is not limited to the above embodiments, and any improvements and modifications made by those skilled in the art based on the disclosure of the present invention without departing from the scope of the invention should be within the protection scope of the present invention.

Claims

1. A method for controllable construction of catalyst layer cracks in a fuel cell based on a regulated drying mode, characterized in that, Includes the following steps: Construct a gas-liquid equilibrium phase diagram for the solvent system used in the catalyst slurry, and define the surface evaporation zone, the bulk boiling zone, and the rapid vaporization zone; According to the gas-liquid equilibrium phase diagram, the drying mode is controlled by adjusting the drying temperature so that the catalyst slurry is in a selected drying mode region during the drying process. The drying mode is selected from one or more of the following: surface evaporation mode, bulk boiling mode, and rapid vaporization mode. The wet catalyst slurry layer is dried in a drying mode to obtain the fuel cell catalyst layer.

2. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 1, characterized in that, The solvent system is a water-alcohol two-component system; The gas-liquid equilibrium phase diagram is obtained by solving the gas-liquid equilibrium equations of the two-component solvent, which include: The constraints are: In the formula, Represents the degrees of freedom of the gas phase. The number of degrees of freedom representing the liquid phase. Indicates the gas phase composition. The fugacity coefficient represents the gas phase. Indicates pressure, Indicates the liquid phase composition. Represents the activity coefficient. The fugacity coefficient represents saturated steam. Indicates saturated vapor pressure. Represents matter i Partial molar volume, The gas constant is... This refers to absolute temperature.

3. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 1, characterized in that, The surface evaporation zone corresponds to the area below the bubble point line in the gas-liquid equilibrium phase diagram. The bulk boiling zone corresponds to the area between the bubble point line and the dew point line in the gas-liquid equilibrium phase diagram. The rapid vaporization zone corresponds to the area above the dew point line in the gas-liquid equilibrium phase diagram.

4. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 1, characterized in that, The drying mode is achieved by regulating the drying temperature, which is set and dynamically adjusted according to the temperature range of the target drying mode.

5. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 4, characterized in that, When the target drying mode is surface evaporation mode, the drying temperature is constantly controlled at a low temperature; When the target drying mode is the bulk boiling mode, the drying temperature changes dynamically according to a certain pattern during the drying process; When the target drying mode is rapid vaporization mode, the drying temperature is kept constant at a relatively high temperature.

6. A method for controllable construction of catalyst layer cracks in a fuel cell based on a regulated drying mode, as described in claim 1 or 4, characterized in that, The drying pressure is atmospheric pressure or near-atmospheric pressure.

7. A method for controllable construction of catalyst layer cracks in a fuel cell based on a regulated drying mode, as described in claim 1 or 4, characterized in that, The drying method is oven drying or plate drying.

8. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 1, characterized in that, Drying under the surface evaporation mode results in the formation of a suitable number of cracks on the surface of the resulting catalyst layer. Drying under the bulk boiling mode resulted in the formation of dense cracks on the surface of the resulting catalyst layer. Drying under the rapid vaporization mode results in a catalyst layer surface with no cracks or very few cracks.

9. The method for controllable construction of fuel cell catalyst layer cracks based on a regulated drying mode according to claim 1, characterized in that, The method is applicable to catalyst slurry systems using water-alcohol as a solvent.

10. A catalyst layer for a fuel cell, characterized in that, The fuel cell catalyst layer is prepared by the method described in any one of claims 1-9, and the surface crack coverage of the fuel cell catalyst layer is controllably adjustable according to the drying mode.

Images