Anode gas diffusion layer structure and anti-reverse electrode membrane electrode

Abstract

The utility model provides an anode gas diffusion layer structure and an anti-antipole membrane electrode. An anode micropore layer is arranged on one side of an anode substrate layer, and an anode anti-antipole layer is arranged on the other side of the anode substrate layer. The antipole resistance is more directly contacted with the humidified gas, so that the antipole resistance of the membrane electrode is improved, and the occurrence time of carbon corrosion is delayed; the anti-reverse pole coating is not in direct contact with the catalyst, so that the shielding effect on the performance of the fuel cell is avoided, and the performance of the cell is improved; the anti-antipole coating is independently prepared, the plane gradient design of the antipole performance of the GDL can be more conveniently achieved, more anti-antipole catalysts are sprayed to the anode outlet area and the area close to the edge of the flow field, and the cost is effectively saved.

Description

Technical Field

[0001] The utility model belongs to the technical field of hydrogen fuel cells, and particularly relates to an anode gas diffusion layer structure and an anti-reversal membrane electrode. Background Art

[0002] A proton exchange membrane fuel cell can directly convert hydrogen into electric energy, and has the advantages of zero pollution, high energy conversion efficiency and low working temperature. It is one of the most promising new energy technologies in the future.

[0003] During the start-stop, load change and cold start processes of vehicle fuel cells, insufficient air supply often occurs. The side reaction caused by oxygen deficiency on the cathode side of the stack is mainly the electrochemical reduction of protons on the cathode side. Since the electrode potential is relatively low, no other side reactions occur, and the application risk to the stack is relatively low; while the fuel deficiency on the anode side will cause the electrochemical oxidation of oxygen in water molecules, and generate a relatively high electrode potential. At the same time, it will cause the electrochemical oxidation corrosion of carbon materials, have an irreversible impact on the electrode structure, and lead to a serious attenuation of electrode performance. Therefore, it poses a greater risk to the application of the stack and is an issue that needs to be focused on in the case of insufficient air supply. When the anode is overall lacking air, water electrolysis occurs first. When the available water or the activity of the OER catalyst on the anode decreases, the carbon corrosion reaction will be significantly accelerated to maintain the charge balance of the battery. The cell voltage of the anode continuously increases, further accelerating carbon corrosion, and the reversal voltage will also continuously increase. The electrochemical reactions that occur are as follows:

[0004] Anode 1: 2H2O = O2 + 4H + +4e - (E = 1.4V, E0 = 1.23V)

[0005] Anode 2: C + H2O = CO + 2H + +2e - (E = 1.5V, E0 = 0.21V)

[0006] Anode 3: C + 2H2O = CO2 + 4H + +4e - (E = 2.0V, E0 = 0.52V)

[0007] Cathode: O2 + 4H + +4e - = 2H2O (E = 1.0V, E0 = 1.23V)

[0008] The high potential of the anode will trigger the oxidation reaction of other components of the anode, such as the ionomer. A large amount of water will be consumed during the reversal process, the electrolyte will be significantly dehydrated, a relatively large ionic resistance and ohmic heat will be generated, and the heat generated by the reaction will accelerate the aging of the proton exchange membrane, carbon carrier corrosion, irreversible damage. The extremely high potential difference of the stack may puncture the membrane electrode and cause a short circuit.

[0009] From a thermodynamic point of view, carbon corrosion mainly occurs below -1.0V, and above -1.0V, carbon corrosion is relatively slow and negligible, and water electrolysis is prioritized. Therefore, in order to prevent and reduce the corrosion of the carbon support of the anode catalyst layer during the reverse polarity, it is usually necessary to add a water electrolysis catalyst to reduce the water electrolysis potential, so that the water electrolysis oxygen evolution reaction occurs during the reverse polarity, thereby inhibiting the carbon corrosion reaction. Commonly used anti-reverse polarity catalysts are iridium, ruthenium and their oxides. Such catalysts need to be added on the anode side during the preparation of anti-reverse polarity membrane electrodes. Since iridium, ruthenium and their oxides themselves do not have hydrogen oxidation reaction activity, they have a shielding effect on the performance of fuel cells. In addition, commercial iridium, ruthenium and their oxides are physically mixed and added at the anode, which is very easy to be unevenly dispersed, making it difficult to give full play to the performance of the anti-reverse polarity catalyst, further increasing its shielding effect on the performance of fuel cells.

[0010] In the prior art, the patent with publication number CN113690451A published on November 23, 2021, discloses an anti-reverse polarity gas diffusion layer and its preparation method and application, by adding an anti-reverse polarity catalyst to the microporous layer slurry when preparing the microporous layer of the gas diffusion layer, and then performing an impregnation and roasting process with the substrate, so that the anti-reverse polarity catalyst is present in the microporous layer of the gas diffusion layer to achieve the purpose of anti-reverse polarity. However, there are the following problems: the anti-reverse polarity catalyst loading and loading uniformity are difficult to control during the impregnation process, resulting in a large amount of anti-reverse polarity catalyst used, high cost, and the subsequent drying and roasting process is very likely to cause the anti-reverse polarity catalyst to agglomerate and deactivate, affecting its anti-reverse polarity performance.

[0011] The patent with the announcement number of Chinese invention patent CN 220569713 published on March 8, 2024, discloses an anti-reverse polarity gas diffusion layer structure and membrane electrode. By improving the anti-reverse polarity gas diffusion layer structure, a hydrophilic coating and an anti-reverse polarity coating are designed on the gas diffusion layer. The hydrophilic coating is coated on the surface of the gas diffusion layer in a grid shape, and the anti-reverse polarity coating is coated in the position within the hydrophilic coating grid. The hydrophilic coating and the anti-reverse polarity coating do not overlap. There is a limited hydrophilic area, and the anti-reverse polarity coating is close to the catalytic layer, which shields the battery performance.

[0012] Therefore, there is an urgent need to provide a new gas diffusion layer structure to improve its anti-reverse polarity performance. Utility Model Content

[0013] The utility model aims to provide an anode gas diffusion layer structure, comprising an anode substrate layer, an anode microporous layer is arranged on one side of the anode substrate layer, and an anode anti-reverse polarity layer is arranged on the other side.

[0014] Another object of the present invention is to provide an anti-reversal membrane electrode, including the above-mentioned anode gas diffusion layer structure, wherein the anode anti-reversal layer is disposed on the other side of the anode base layer opposite to the anode microporous layer; generally, the microporous layer is a hydrophobic layer, and the increase in hydrophobicity may cause excessive local pressure at the interface between the catalyst layer and the microporous hydrophobic layer, which in turn affects the performance of the membrane electrode. However, the structure of the present invention can not only prevent the anti-reversal substance from directly contacting the catalyst layer, but also achieve the purpose of anti-reversal, realizing the precise distribution setting of the anti-reversal catalyst and saving costs.

[0015] The specific technical solution of the present invention is as follows:

[0016] An anode gas diffusion layer structure provided by the present invention includes an anode base layer, an anode microporous layer is disposed on one side of the anode base layer, and an anode anti-reversal layer is disposed on the other side of the anode base layer.

[0017] The thickness range of the anode base layer is 100-200 μm;

[0018] The thickness range of the anode microporous layer is 5-20 μm;

[0019] The thickness range of the anode anti-reversal layer is 2-12 μm;

[0020] The anode anti-reversal layer includes a first anode anti-reversal layer, or the anode anti-reversal layer includes a first anode anti-reversal layer and a second anode anti-reversal layer;

[0021] The first anode anti-reversal layer is disposed on the anode base layer and directly contacts the anode base layer;

[0022] The first anode anti-reversal layer is one layer or multiple layers;

[0023] The second anode anti-reversal layer is disposed on the first anode anti-reversal layer and is disposed opposite to the anode base layer;

[0024] The area of the second anode anti-reversal layer is smaller than that of the first anode anti-reversal layer; that is, the second anode anti-reversal layer is locally disposed on the first anode anti-reversal layer;

[0025] The anti-reversal catalyst loading in the first anode anti-reversal layer is less than the anti-reversal catalyst loading in the second anode anti-reversal layer;

[0026] The anti-reversal catalyst loading in the first anode anti-reversal layer is 0.01 mg / cm 2 ;

[0027] The anti-reversal catalyst loading in the second anode anti-reversal layer is 0.02-0.03 mg / cm 2 ;

[0028] On one side of the anode base layer, an anode microporous layer is provided, that is, an anode gas diffusion layer containing an anode microporous layer, which is a gas diffusion layer containing an anode microporous layer prepared in the market and belongs to a commercially available product;

[0029] An anti-reversal membrane electrode provided by the present invention includes the above-mentioned anode gas diffusion layer structure, cathode gas diffusion layer structure and CCM structure;

[0030] The CCM structure is arranged between the gas diffusion layer structure and the cathode gas diffusion layer structure; the CCM structure includes a proton membrane, an anode catalyst layer and a cathode catalyst layer, and the proton membrane is arranged between the anode catalyst layer and the cathode catalyst layer;

[0031] The anode catalyst layer is arranged on one side of the proton membrane close to the anode gas diffusion layer structure;

[0032] The cathode catalyst layer is arranged on one side of the proton membrane close to the cathode gas diffusion layer structure;

[0033] The cathode gas diffusion layer structure includes a cathode base layer and a cathode microporous layer.

[0034] The anti-reversal membrane electrode includes a proton membrane, and an anode catalyst layer, an anode microporous layer, an anode base layer and an anode anti-reversal layer are sequentially arranged on one side of the proton membrane; a cathode catalyst layer, a cathode microporous layer and a cathode base layer are sequentially arranged on the other side of the proton membrane.

[0035] The anti-reversal membrane electrode includes a proton membrane, and an anode catalyst layer, an anode microporous layer, an anode base layer and a first anode anti-reversal layer are sequentially arranged on one side of the proton membrane; a cathode catalyst layer, a cathode microporous layer and a cathode base layer are sequentially arranged on the other side of the proton membrane.

[0036] The anti-reversal membrane electrode includes a proton membrane, and an anode catalyst layer, an anode microporous layer, an anode base layer, a first anode anti-reversal layer and a second anode anti-reversal layer are sequentially arranged on one side of the proton membrane; a cathode catalyst layer, a cathode microporous layer and a cathode base layer are sequentially arranged on the other side of the proton membrane.

[0037] In the present invention, an anode microporous layer is arranged on one side of the anode base layer, and an anode anti-reversal layer is arranged on the other side. The anti-reversal layer is in more direct contact with the humidified gas, improving the anti-reversal ability of the membrane electrode and delaying the occurrence time of carbon corrosion; the anti-reversal coating has no direct contact with the catalyst, avoiding its shielding effect on the performance of the fuel cell and improving the battery performance; the anti-reversal coating is prepared separately, which is more convenient to realize the planar gradient design of the anti-reversal performance of the GDL. More anti-reversal catalysts are sprayed in the anode outlet area and the area close to the flow field edge, effectively saving costs. Description of the Drawings

[0038] Figure 1Schematic diagram of the anode gas diffusion layer structure of the present invention;

[0039] Figure 2 Schematic diagram of the anti-reversal membrane electrode structure of the present invention;

[0040] Figure 3 Schematic diagram of the structure of the first anode anti-reversal layer;

[0041] Figure 4 Schematic diagram of the structure of the second anode anti-reversal layer;

[0042] In the figure: 1 - Anode gas diffusion layer structure, 10 - Anode base layer, 11 - Anode microporous layer, 12 - Anode anti-reversal layer; 2 - Cathode gas diffusion layer structure, 20 - Cathode base layer, 21 - Cathode microporous layer; 3 - CCM structure, 30 - Proton membrane, 31 - Anode catalyst layer, 32 - Cathode catalyst layer; 121 - First anode anti-reversal layer, 122 - Second anode anti-reversal layer. Detailed implementation manners

[0043] To make the objectives, technical solutions and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below in conjunction with the embodiments of the present utility model. Obviously, the described embodiments are part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0044] An anode gas diffusion layer structure 1 provided by the present utility model includes an anode base layer 10, an anode microporous layer 11 is provided on one side of the anode base layer 10, and an anode anti-reversal layer 12 is provided on the other side of the anode base layer 10.

[0045] The thickness range of the anode base layer 10 is 100 - 200 μm;

[0046] The thickness range of the anode microporous layer 11 is 5 - 20 μm;

[0047] The thickness range of the anode anti-reversal layer 12 is 2 - 12 μm;

[0048] An anode microporous layer 11 is provided on one side of the anode base layer 10, that is, an anode gas diffusion layer containing the anode microporous layer 11, which is a gas diffusion layer containing the anode microporous layer 11 that has been prepared in the market and belongs to a commercially available product;

[0049] The anode anti-reversal layer 12 uses an anti-reversal paste, and the anti-reversal paste includes an anti-reversal catalyst and an organic solvent.

[0050] The anti-reverse-polarity catalyst is one or two of IrO2 and RuO2;

[0051] Alternatively, the anti-reverse-polarity catalyst is a composite material of IrO2 and / or RuO2 and any one or more of TiO2, SnO2, CeO2, and Ta2O5.

[0052] The organic solvent is one or several of ethanol, propanol, n-propanol, ethylene glycol, isopropanol, and glycerol. When multiple organic solvents are used, the multiple organic solvents can be directly mixed. Since the above-mentioned organic solvents are of the same type, no new substances will be generated during mixing.

[0053] Furthermore, the anti-reverse-polarity paste further includes water.

[0054] Preferably, the anti-reverse-polarity paste includes IrO2, deionized water, and an organic solvent, and is made by mixing the three raw materials in a mass ratio of 1-10:150-200:200-300.

[0055] The anode anti-reverse-polarity layer 12 is prepared by a coating method, and is coated by screen printing, spraying, or coating.

[0056] The anode anti-reverse-polarity layer 12 includes a first anode anti-reverse-polarity layer 121, or the anode anti-reverse-polarity layer includes a first anode anti-reverse-polarity layer 121 and a second anode anti-reverse-polarity layer 122;

[0057] The first anode anti-reverse-polarity layer 121 is disposed on the anode base layer 10 and is in direct contact with the anode base 10 layer;

[0058] The first anode anti-reverse-polarity layer 121 is one layer or multiple layers;

[0059] The second anode anti-reverse-polarity layer 122 is disposed on the first anode anti-reverse-polarity layer 121 and is disposed opposite to the anode base layer 10;

[0060] The area of the second anode anti-reverse-polarity layer 122 is smaller than that of the first anode anti-reverse-polarity layer 121; that is, the second anode anti-reverse-polarity layer 122 is locally disposed on the first anode anti-reverse-polarity layer 121;

[0061] The anti-reverse-polarity catalyst loading in the first anode anti-reverse-polarity layer 121 is less than the anti-reverse-polarity catalyst loading in the second anode anti-reverse-polarity layer 122;

[0062] The anti-reverse-polarity catalyst loading in the first anode anti-reverse-polarity layer 121 is 0.01 mg / cm 2 ;

[0063] The anti-reverse-polarity catalyst loading in the second anode anti-reverse-polarity layer 122 is 0.02 - 0.03 mg / cm 2 ;

[0064] The second anode anti-reversal layer 122 is disposed at a corresponding position in the anode outlet region and near the flow field edge region.

[0065] An anti-reversal membrane electrode provided by the present utility model includes the above-mentioned anode gas diffusion layer structure 1, cathode gas diffusion layer structure 2, and CCM structure 3;

[0066] The CCM structure 3 is disposed between the anode gas diffusion layer structure 1 and the cathode gas diffusion layer structure 2; the CCM structure 3 includes a proton membrane 30, an anode catalyst layer 31, and a cathode catalyst layer 32, and the proton membrane 30 is disposed between the anode catalyst layer 31 and the cathode catalyst layer 32;

[0067] The anode catalyst layer 31 is disposed on one side of the proton membrane 30 close to the anode gas diffusion layer structure 1;

[0068] The cathode catalyst layer 32 is disposed on one side of the proton membrane 30 close to the cathode gas diffusion layer structure 2;

[0069] The cathode gas diffusion layer structure 2 includes a cathode base layer 20 and a cathode microporous layer 21.

[0070] The anti-reversal membrane electrode includes a proton membrane 30. An anode catalyst layer 31, an anode microporous layer 11, an anode base layer 10, and an anode anti-reversal layer 12 are sequentially disposed on one side of the proton membrane 30; a cathode catalyst layer 32, a cathode microporous layer 21, and a cathode base layer 20 are sequentially disposed on the other side of the proton membrane 30.

[0071] Preferably, the anti-reversal membrane electrode includes a proton membrane 30. An anode catalyst layer 31, an anode microporous layer 11, an anode base layer 10, and a first anode anti-reversal layer 121 are sequentially disposed on one side of the proton membrane 30; a cathode catalyst layer 32, a cathode microporous layer 21, and a cathode base layer 20 are sequentially disposed on the other side of the proton membrane 30.

[0072] More preferably, the anti-reversal membrane electrode includes a proton membrane 30. An anode catalyst layer 31, an anode microporous layer 11, an anode base layer 10, a first anode anti-reversal layer 121, and a second anode anti-reversal layer 122 are sequentially disposed on one side of the proton membrane 30; a cathode catalyst layer 32, a cathode microporous layer 21, and a cathode base layer 20 are sequentially disposed on the other side of the proton membrane 30.

[0073] The structure of the present utility model utilizes a commercially available anode gas diffusion layer material containing an anode microporous layer, and an anode anti-polarization layer is prepared on one side of the anode substrate layer of the anode gas diffusion layer to control the catalyst dosage in the area prone to polarization reversal. Due to the presence of the anti-polarization substance, the fuel cell first undergoes a water electrolysis reaction, thereby delaying the occurrence of severe carbon corrosion. This also improves the anti-polarization ability of the anode gas diffusion layer, avoids the occurrence of corrosion, ensures the stability of the gas diffusion layer during polarization reversal, protects the fuel cell, and enables the battery to have good performance before and after polarization reversal.

[0074] The structure provided by the present utility model has the anode anti-polarization layer in more direct contact with the humidified gas, improving the anti-polarization ability of the membrane electrode and delaying the occurrence time of carbon corrosion; the anode anti-polarization layer has no direct contact with the anode catalyst, avoiding its shielding effect on the performance of the fuel cell and improving the battery performance; the anode anti-polarization layer is prepared by coating with an anti-polarization slurry, and can be separately prepared on a commercially available anode gas diffusion layer material containing an anode microporous layer, which is more convenient to realize the planar gradient design of the anti-polarization performance of the gas diffusion layer GDL. More anti-polarization catalyst is sprayed in the anode outlet area and the area near the flow field edge, effectively saving costs.

[0075] The following are several specific implementation processes of the present invention:

[0076] Example 1

[0077] An anode gas diffusion layer structure 1 includes an anode substrate layer 10, an anode microporous layer 11 is provided on one side of the anode substrate layer 10, and an anode anti-polarization layer 12 is provided on the other side of the anode substrate layer 10.

[0078] The anode anti-polarization layer 12 includes a first anode anti-polarization layer 121; the anti-polarization catalyst loading in the first anode anti-polarization layer 121 is 0.01 mg / cm 2 ;

[0079] An anti-polarization membrane electrode includes a proton membrane 30. On one side of the proton membrane 30, an anode catalyst layer 31, an anode microporous layer 11, an anode substrate layer 10, and a first anode anti-polarization layer 121 are sequentially arranged; on the other side of the proton membrane 30, a cathode catalyst layer 32, a cathode microporous layer 21, and a cathode substrate layer 20 are sequentially arranged; among them, the first anode anti-polarization layer 121 is obtained by coating the surface of the anode substrate layer 10 with an anti-polarization slurry by screen printing; the anti-polarization catalyst IrO2 is used in the anti-polarization slurry used, and IrO2, deionized water, and isopropanol are mixed evenly in a mass ratio of 1:153:230. The anti-polarization catalyst IrO2 loading in the prepared first anode anti-polarization layer 121 is 0.01 mg / cm 2 。

[0080] Example 2

[0081] An anodic gas diffusion layer structure 1, comprising an anodic base layer 10, an anodic microporous layer 11 is provided on one side of the anodic base layer 10, and an anodic anti-polarization layer 12 is provided on the other side of the anodic base layer 10.

[0082] The anodic anti-polarization layer includes a first anodic anti-polarization layer 121 and a second anodic anti-polarization layer 122; the area of the second anodic anti-polarization layer 122 is smaller than that of the first anodic anti-polarization layer 121; the anti-polarization catalyst loading in the first anodic anti-polarization layer 121 is 0.01 mg / cm 2 ; the anti-polarization catalyst loading in the second anodic anti-polarization layer 122 is 0.02 mg / cm 2 .

[0083] An anti-polarization membrane electrode, comprising a proton membrane 30, an anodic catalyst layer 31, an anodic microporous layer 11, an anodic base layer 10, a first anodic anti-polarization layer 121 and a second anodic anti-polarization layer 122 are sequentially provided on one side of the proton membrane 30; a cathode catalyst layer 32, a cathode microporous layer 21 and a cathode base layer 20 are sequentially provided on the other side of the proton membrane 30; wherein the first anodic anti-polarization layer 121 is obtained by coating an anti-polarization slurry on the surface of the anodic base layer 10 and drying; the second anodic anti-polarization layer 122 is obtained by coating the anti-polarization slurry on a partial surface of the first anodic anti-polarization layer 121, and is coated at the response positions in the anodic outlet region where fuel under-gas is most likely to occur and in the region close to the flow field edge; the raw materials of the anti-polarization slurry used are the same as those in Example 1; the anti-polarization catalyst IrO2 loading in the prepared first anodic anti-polarization layer 121 is 0.01 mg / cm 2 ; the anti-polarization catalyst IrO2 loading in the second anodic anti-polarization layer 122 is 0.02 mg / cm 2 .

[0084] Example 3

[0085] An anodic gas diffusion layer structure 1, comprising an anodic base layer 10, an anodic microporous layer 11 is provided on one side of the anodic base layer 10, and an anodic anti-polarization layer 12 is provided on the other side of the anodic base layer 10.

[0086] The anodic anti-polarization layer includes a first anodic anti-polarization layer 121 and a second anodic anti-polarization layer 122; the area of the second anodic anti-polarization layer 122 is smaller than that of the first anodic anti-polarization layer 121; the anti-polarization catalyst loading in the first anodic anti-polarization layer 121 is 0.01 mg / cm 2 ; the anti-polarization catalyst loading in the second anodic anti-polarization layer 122 is 0.03 mg / cm 2 .

[0087] An anti-reversal membrane electrode includes a proton membrane 30. On one side of the proton membrane 30, an anode catalyst layer 31, an anode microporous layer 11, an anode substrate layer 10, a first anode anti-reversal layer 121, and a second anode anti-reversal layer 122 are sequentially arranged; on the other side of the proton membrane 30, a cathode catalyst layer 32, a cathode microporous layer 21, and a cathode substrate layer 20 are sequentially arranged; wherein the first anode anti-reversal layer 121 is obtained by coating an anti-reversal paste on the surface of the anode substrate layer 10 by a coating method and drying; the second anode anti-reversal layer 122 is obtained by coating the anti-reversal paste on a partial surface of the first anode anti-reversal layer 121, and is coated at the response position in the anode outlet area where fuel under-gas is most likely to occur and in the area near the edge of the flow field; the raw materials of the used anti-reversal paste are the same as those in Example 1; the loading of the anti-reversal catalyst IrO2 in the prepared first anode anti-reversal layer 121 is 0.01 mg / cm 2 ; the loading of the anti-reversal catalyst IrO2 in the second anode anti-reversal layer 122 is 0.03 mg / cm 2 .

[0088] Comparative Example 1

[0089] An anti-reversal membrane electrode, in which an anode anti-reversal layer is provided with an anode catalyst layer; IrO2 is added to the basic anode catalyst layer paste, and the mass ratio of IrO2 to the platinum-carbon catalyst is 1:5. The loading of the anti-reversal catalyst IrO2 in the prepared anode catalyst layer is 0.01 mg / cm 2 .

[0090] The membrane electrode structures of Example 1 and Comparative Example 1 are compared as shown in Table 1.

[0091] Table 1 Membrane Electrode Structures of Example 1 and Comparative Example 1

[0092]

[0093] The above anti-reversal membrane electrodes are assembled into single cells, and then anti-reversal tests are carried out. The tests are performed in accordance with the group standard T / CAAMTB 12-2020 "Test Method for Proton Exchange Membrane Fuel Cell Membrane Electrodes" of the China Automotive Industry Association. Using a single cell test bench, the single cell is assembled according to Section 5.3 (active area 25 cm 2 ), and installed on the proton exchange membrane fuel cell test machine. The test adopts a simulated reversal condition, that is, nitrogen at the anode, air at the cathode, the pressure is normal pressure, the gas flow rate is 1 SLPM for both, the relative humidity is 100%, and the cell temperature is 75 °C. The cell is externally connected to a constant current source, the anode is connected to the positive pole of the constant current source, the cathode is connected to the negative pole of the constant current source, and the current density is set to 0.2 A / cm 2 , and the cut-off voltage of the cell is set to -1.5 V. The cell voltage does not reach the cut-off voltage and the simulated reversal condition stops, and the continuous operation time of the simulated reversal is recorded.

[0094] The comparative example 1 and Examples 1-3 were tested in the same way. The specific test results are shown in Table 2. It can be seen from the table that the single cell made of the gas diffusion layer with the anti-polarization function prepared above has excellent anti-polarization performance.

[0095] Table 2 Test results of the anti-polarization membrane electrode performance of each example and comparative example

[0096]

[0097]

[0098] It can be seen from the polarization performance and the shutdown anti-polarization time in Table 1 that Examples 1-3 have good anti-polarization performance. The structure of the present invention makes the anti-polarization more directly in contact with the humidified gas, improves the anti-polarization ability of the membrane electrode, and delays the occurrence time of carbon corrosion.

[0099] In the present invention, an anti-polarization coating is provided on one side of the base layer of the gas diffusion layer material containing a microporous layer to control the catalyst dosage in the area prone to polarization. Due to the presence of the anti-polarization substance, the fuel cell first undergoes a water electrolysis reaction, thereby delaying the occurrence of severe carbon corrosion. This also improves the anti-polarization ability of the gas diffusion layer, ensures the stability of the gas diffusion layer during polarization, protects the fuel cell, and enables the battery to have good performance before and after polarization.

[0100] The description of the above embodiments is for the convenience of those of ordinary skill in the art to understand and use the invention. It is obvious that those skilled in the art can easily make various modifications to these embodiments and apply the general principles described herein to other embodiments without creative labor. Therefore, the present invention is not limited to the above embodiments, and the improvements and modifications made by those skilled in the art without departing from the scope of the present invention should be within the protection scope of the present invention.

Claims

1. An anode gas diffusion layer structure, characterized in that: The anode gas diffusion layer structure comprises an anode base layer, an anode microporous layer is arranged on one side of the anode base layer, and an anode anti-reverse layer is arranged on the other side of the anode base layer.

2. The anode gas diffusion layer structure according to claim 1, characterized in that: The anode anti-reverse polarity layer includes a first anode anti-reverse polarity layer, or the anode anti-reverse polarity layer includes a first anode anti-reverse polarity layer and a second anode anti-reverse polarity layer.

3. The anode gas diffusion layer structure according to claim 2, characterized in that: The first anode anti-reverse polarity layer is disposed on the anode base layer.

4. The anode gas diffusion layer structure according to claim 2 or 3, characterized in that: The second anode anti-reverse polarity layer is disposed on the first anode anti-reverse polarity layer.

5. The anode gas diffusion layer structure according to claim 4, characterized in that: The second anode anti-reverse polarity layer has an area smaller than that of the first anode anti-reverse polarity layer.

6. An anti-reverse polarity membrane electrode, characterized in that: The anti-reverse polarity membrane electrode comprises the anode gas diffusion layer structure, the cathode gas diffusion layer structure and the CCM structure according to any one of claims 1 to 5.

7. The anti-reverse polarity membrane electrode according to claim 6, characterized in that: The CCM structure is arranged between the gas diffusion layer structure and the cathode gas diffusion layer structure; the CM structure comprises a proton membrane, an anode catalyst layer and a cathode catalyst layer, and the proton membrane is arranged between the anode catalyst layer and the cathode catalyst layer.

8. The anti-reverse polarity membrane electrode according to claim 6 or 7, characterized in that: The cathode gas diffusion layer structure comprises a cathode base layer and a cathode microporous layer.

9. The anti-reverse polarity membrane electrode according to claim 6 or 7, characterized in that: The anti-reverse polarity membrane electrode comprises a proton membrane, on one side of which an anode catalyst layer, an anode microporous layer, an anode base layer and an anode anti-reverse polarity layer are sequentially arranged; on the other side of the proton membrane, a cathode catalyst layer, a cathode microporous layer and a cathode base layer are sequentially arranged.

10. The anti-reverse polarity membrane electrode according to claim 6 or 7, characterized in that: The anti-reverse polarity membrane electrode comprises a proton membrane, and an anode catalyst layer, an anode microporous layer, an anode base layer, a first anode anti-reverse polarity layer and a second anode anti-reverse polarity layer are sequentially arranged on one side of the proton membrane; a cathode catalyst layer, a cathode microporous layer and a cathode base layer are sequentially arranged on the other side of the proton membrane.

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