Gas diffusion layer and preparation method thereof, membrane electrode assembly, alkaline electrolytic bath and water electrolysis hydrogen production equipment

Abstract

The invention relates to a gas diffusion layer and a preparation method thereof, a membrane electrode assembly, an alkaline electrolytic cell and water electrolysis hydrogen production equipment. The gas diffusion layer comprises a hydrophobic substrate layer and a microporous layer arranged on at least one surface of the hydrophobic substrate layer, and the microporous layer comprises a conductive material and an anion ionomer. By arranging the microporous layer containing the conductive material and the anion ionomer on at least one surface of the hydrophobic substrate layer, the resistivity of the diffusion gas layer is low, and the ohmic resistance can be effectively reduced. When the gas diffusion layer is used in the alkaline electrolytic cell, the transmission capability and the electron conduction capability of OH <-> in electrolyte can be effectively improved, the mass transfer and transportation loss is reduced, and the voltage of the alkaline electrolytic cell is effectively reduced, so that the operation power of the alkaline electrolytic cell is effectively reduced.

Description

Technical Field

[0001] The present application relates to the field of new energy technology, and in particular to a gas diffusion layer and a preparation method thereof, a membrane electrode assembly, an alkaline electrolyzer, and a water electrolysis hydrogen production device. Background Art

[0002] Due to the use of fossil fuels, the concentration of carbon dioxide in the atmosphere continues to rise. The technology of producing hydrogen by water electrolysis has the advantages of high electrolysis efficiency, high hydrogen purity, and pollution-free reaction. Among them, alkaline membrane water electrolysis (AEM) can use non-precious metal catalysts at the anode, which not only saves costs, but also avoids the problem of anode catalyst dissolving in the electrolyte in proton exchange membrane water electrolysis (PEM), and has potential market application prospects. However, the operating power of the electrolyzer used in traditional alkaline membrane water electrolysis is relatively high.

[0003] Therefore, it is necessary to improve the traditional technology. Summary of the invention

[0004] Based on this, the present application provides a gas diffusion layer with low operating power and a preparation method thereof, a membrane electrode assembly, an alkaline electrolyzer and a water electrolysis hydrogen production device.

[0005] The technical solution of this application to solve the above technical problems is as follows.

[0006] In a first aspect, the present application provides a gas diffusion layer, comprising a hydrophobic substrate layer and a microporous layer disposed on at least one surface of the hydrophobic substrate layer, wherein the microporous layer comprises a conductive material and an anionic ionomer.

[0007] In some embodiments, in the gas diffusion layer, the anion ionomer includes AP2-HNN8, FAA3-shredded film, PiperION A5-HCO 3 and at least one of XA-9.

[0008] In some of the embodiments, in the gas diffusion layer, the mass ratio of the anion ionomer to the conductive material is 0.01-0.2:1.

[0009] In some embodiments, in the gas diffusion layer, the thickness of the microporous layer is 1 μm to 10 μm.

[0010] In some of the embodiments, in the gas diffusion layer, the conductive material includes at least one of Super P, acetylene black, Ketjen black, carbon nanotubes and graphene.

[0011] In some embodiments, in the gas diffusion layer, the hydrophobic base layer comprises a hydrophobic carbon substrate; and / or

[0012] The thickness of the hydrophobic substrate is 0.3 mm to 0.9 mm.

[0013] A second aspect of the present application provides a method for preparing a gas diffusion layer, comprising the following steps:

[0014] The conductive material, the anionic ionomer and the solvent are mixed to prepare a slurry;

[0015] The slurry is disposed on at least one surface of the hydrophobic base layer and dried to form a microporous layer on at least one surface of the hydrophobic base layer.

[0016] The third aspect of the present application provides a membrane electrode assembly, comprising a cathode gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer and an anode gas diffusion layer arranged in a stacked manner, at least one of the cathode gas diffusion layer and the anode gas diffusion layer is the above-mentioned gas diffusion layer or the gas diffusion layer prepared by the above-mentioned preparation method, and the microporous layer is arranged between the cathode catalyst layer or the anode catalyst layer and the hydrophobic substrate layer.

[0017] A fourth aspect of the present application provides an alkaline electrolytic cell comprising the above-mentioned membrane electrode assembly.

[0018] The fifth aspect of the present application provides a water electrolysis hydrogen production device, including the above-mentioned alkaline electrolyzer.

[0019] Compared with the prior art, the gas diffusion layer of the present application has the following beneficial effects:

[0020] The gas diffusion layer of the present application has a microporous layer containing a conductive material and an anion ionomer disposed on at least one surface of the hydrophobic substrate layer, so that the resistivity of the diffusion gas layer is low, and the ohmic resistance can be effectively reduced.

[0021] The above-mentioned gas diffusion layer is used in an alkaline electrolyzer to effectively increase the OH content in the electrolyte. - The transmission capacity and electron conduction capacity of the alkaline electrolyzer can be improved, the mass transfer and transport losses can be reduced, and the voltage of the alkaline electrolyzer can be effectively reduced, thereby effectively reducing the operating power of the alkaline electrolyzer. DETAILED DESCRIPTION

[0022] The present application will be further described in detail below in conjunction with the embodiments and examples. It should be understood that these embodiments and examples are only used to illustrate the present application and are not used to limit the scope of the present application. The purpose of providing these embodiments and examples is to make the understanding of the disclosure of the present application more thorough and comprehensive. It should also be understood that the present application can be implemented in many different forms, and is not limited to the embodiments and examples described herein. Those skilled in the art can make various changes or modifications without violating the connotation of the present application, and the equivalent form obtained also falls within the protection scope of the present application. For example, the features described or described as part of an embodiment can be combined in another embodiment in a suitable manner to produce a new embodiment. In addition, in the description below, a large number of specific details are given in order to provide a more comprehensive understanding of the present application, and it should be understood that the present application can be implemented without one or more of these details.

[0023] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as those commonly understood by those skilled in the art to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing implementation modes and embodiments and are not intended to limit this application.

[0024] Unless otherwise specified or incompatible herewith, the terms and phrases used herein shall have the following meanings:

[0025] In the present application, "plurality", "multiple", "multiple times", etc., unless otherwise specified, refer to a quantity greater than 2 or equal to 2. For example, "one or more" means one or greater than or equal to two.

[0026] As used herein, "combination thereof", "any combination thereof", "any combination thereof" etc. include all suitable combinations of any two or more of the listed items.

[0027] Herein, the “suitable” mentioned in “suitable combination”, “suitable method”, “any suitable method”, etc., shall be based on the ability to implement the technical solution of this application, solve the technical problems of this application, and achieve the expected technical effects of this application.

[0028] Herein, "preferred", "better", "more preferred", and "suitable" are only used to describe implementation methods or examples with better effects, and it should be understood that they do not constitute a limitation on the scope of protection of this application. If multiple "preferred" items appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "preferred" item is independent.

[0029] In the present application, "further", "further", "particularly" and the like are used for descriptive purposes to indicate differences in content, but should not be construed as limiting the scope of protection of the present application.

[0030] In this application, "optionally", "optional", and "optional" mean optional or dispensable, that is, any one of the two parallel schemes of "yes" or "no". If multiple "options" appear in a technical solution, unless otherwise specified and there is no contradiction or mutual restriction, each "optional" is independent.

[0031] In the present application, the terms "first", "second", "third", "fourth", etc. in "the first aspect", "the second aspect", "the third aspect", "the fourth aspect", etc. are used only for descriptive purposes and cannot be understood as indicating or implying relative importance or quantity, nor can they be understood as implicitly indicating the importance or quantity of the indicated technical features. Moreover, "first", "second", "third", "fourth", etc. only serve the purpose of non-exhaustive enumeration and description, and it should be understood that they do not constitute a closed limitation on quantity.

[0032] In the present application, the technical features described in an open manner include closed technical solutions composed of the listed features, and also include open technical solutions containing the listed features.

[0033] In the present application, when it comes to a numerical interval (i.e., a numerical range), unless otherwise specified, the distribution of the optional numerical values ​​in the numerical interval is considered to be continuous, and includes the two numerical endpoints (i.e., the minimum value and the maximum value) of the numerical interval, and each numerical value between the two numerical endpoints. Unless otherwise specified, when the numerical interval only refers to the integers in the numerical interval, it includes the two endpoint integers of the numerical range, and each integer between the two endpoints, which is equivalent to directly listing each integer. When multiple numerical ranges are provided to describe features or characteristics, these numerical ranges can be combined. In other words, unless otherwise specified, the numerical range disclosed herein should be understood to include any and all sub-ranges included therein. The "numerical value" in the numerical interval can be any quantitative value, such as a number, a percentage, a ratio, etc. "Numerical interval" allows broadly including numerical interval types such as percentage intervals, ratio intervals, and ratio intervals.

[0034] The temperature parameters in this application, unless otherwise specified, are allowed to be either constant temperature treatment or to vary within a certain temperature range. It should be understood that the constant temperature treatment allows the temperature to fluctuate within the accuracy range controlled by the instrument. Fluctuations within the range of ±5°C, ±4°C, ±3°C, ±2°C, and ±1°C are allowed.

[0035] In this application, the term "room temperature" or "normal temperature" generally refers to 4°C to 35°C, for example, 20°C ± 5°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 10°C to 30°C. In some embodiments of this application, "room temperature" or "normal temperature" refers to 20°C to 30°C.

[0036] In this application, when referring to the unit of a data range, if there is a unit only after the right endpoint, it means that the units of the left and right endpoints are the same. For example, 3~5 h means that the units of the left endpoint "3" and the right endpoint "5" are both h (hours).

[0037] All documents mentioned in this application are cited as references in this application, just as each document is cited as reference separately. Unless they conflict with the invention purpose and / or technical solution of this application, the cited documents involved in this application are cited with all contents and all purposes. When the cited documents are involved in this application, the definitions of relevant technical features, terms, nouns, phrases, etc. in the cited documents are also cited. When the cited documents are involved in this application, the examples and preferred methods of the cited relevant technical features can also be incorporated into this application as references, but are limited to the implementation of this application. It should be understood that when the cited content conflicts with the description in this application, the present application shall prevail or be modified adaptively according to the description of this application.

[0038] The mass or weight of the relevant components mentioned in the specification of the embodiments of the present application may not only refer to the specific content of each component, but also indicate the proportional relationship of the mass or weight between the components. Therefore, as long as the content of the relevant components is proportionally enlarged or reduced according to the specification of the embodiments of the present application, it is within the scope disclosed in the specification of the embodiments of the present application. Specifically, the mass or weight described in the specification of the embodiments of the present application may be units known in the chemical industry such as μg, mg, g, and kg.

[0039] An embodiment of the present application provides a gas diffusion layer, comprising a hydrophobic substrate layer and a microporous layer disposed on at least one surface of the hydrophobic substrate layer, wherein the microporous layer comprises a conductive material and an anion ionomer.

[0040] The gas diffusion layer of the present application has a microporous layer containing a conductive material and an anion ionomer disposed on at least one surface of the hydrophobic substrate layer, so that the resistivity of the diffusion gas layer is low, and the ohmic resistance can be effectively reduced.

[0041] The above-mentioned gas diffusion layer is used in an alkaline electrolyzer to effectively increase the OH content in the electrolyte. - The transmission capacity and electron conduction capacity of the alkaline electrolyzer can be improved, the mass transfer and transport losses can be reduced, and the voltage of the alkaline electrolyzer can be effectively reduced, thereby effectively reducing the operating power of the alkaline electrolyzer.

[0042] In some of the examples, the anionic ionomers in the gas diffusion layer include AP2-HNN8, FAA3-shreddedfilm, PiperION A5-HCO 3 and at least one of XA-9.

[0043] Among them, AP2-HNN8 can be Aemion®AP2-HNN8, and XA-9 can be Sustainion®XA-9.

[0044] In some of these examples, the mass ratio of anionic ionomer to conductive material in the gas diffusion layer is 0.01 to 0.2:1.

[0045] It can be understood that the mass ratio of the anionic ionomer to the conductive material includes but is not limited to 0.01:1, 0.02:1, 0.05:1, 0.08:1, 0.1:1, 0.12:1, 0.15:1, 0.18:1, and 0.2:1; in some examples, it can be within the range formed by any two of these point values ​​as end values, the same below.

[0046] In some of these examples, the mass ratio of anionic ionomer to conductive material in the gas diffusion layer is 0.1 to 0.2:1.

[0047] In some of these examples, the mass ratio of anionic ionomer to conductive material in the gas diffusion layer is 0.1 to 0.15:1.

[0048] In some of these examples, the thickness of the microporous layer in the gas diffusion layer is 1 μm to 10 μm.

[0049] It can be understood that the thickness of the microporous layer includes but is not limited to 1 μm, 2 μm, 5 μm, 8 μm, and 10 μm.

[0050] In some of the examples, in the gas diffusion layer, the conductive material includes at least one of carbon black Super P, acetylene black, Ketjen black, carbon nanotubes, and graphene.

[0051] In some examples, in the gas diffusion layer, the hydrophobic substrate layer includes a substrate and a hydrophobic surface layer disposed on the substrate. Further, the microporous layer is disposed on the hydrophobic surface layer. Further, one or two surfaces of the substrate form the hydrophobic surface layer. Further, the microporous layer is disposed on one or two hydrophobic surface layers of the substrate.

[0052] Further, the substrate comprises a carbon substrate; further, the substrate comprises at least one of carbon paper and carbon cloth; further, the thickness of the substrate is 0.3 mm to 0.9 mm; further, the thickness of a single hydrophobic surface layer is 0.5 μm to 3 μm.

[0053] In some of these examples, in the gas diffusion layer, the hydrophobic surface layer includes, but is not limited to, PTFE (polytetrafluoroethylene).

[0054] An embodiment of the present application provides a method for preparing a gas diffusion layer, comprising the following steps:

[0055] The conductive material, the anionic ionomer and the solvent are mixed to prepare a slurry;

[0056] The slurry is disposed on at least one surface of the hydrophobic base layer and dried to form a microporous layer on at least one surface of the hydrophobic base layer.

[0057] It is understood that the anionic ionomer and the solvent can be mixed to form an anionic ionomer dispersion, or the anionic ionomer dispersion can be directly purchased and then mixed with the conductive material. Further, the mass concentration of the anionic ionomer dispersion is 5% to 10%. It is understood that when the anionic ionomer dispersion is mixed with the conductive material, the mass ratio of the anionic ionomer to the conductive material refers to the mass ratio of the anionic ionomer to the conductive material in the anionic ionomer dispersion; further, the mass concentration of the anionic ionomer dispersion includes but is not limited to 5%, 6%, 8%, and 10%.

[0058] In some of the examples, in the method for preparing the gas diffusion layer, the slurry is disposed on at least one surface of the hydrophobic base layer by at least one of spray coating, spin coating, and blade coating.

[0059] In some of the examples, in the method for preparing the gas diffusion layer, drying is performed in a vacuum drying oven.

[0060] In some of the examples, in the method for preparing the gas diffusion layer, the drying temperature is 25°C to 50°C, and the drying time is 10 h to 15 h.

[0061] It can be understood that in the preparation method of the gas diffusion layer, the drying temperature includes but is not limited to 25°C, 30°C, 35°C, 40°C, 45°C, and 50°C, and the time includes but is not limited to 10 h, 11 h, 12 h, 13 h, 14 h, and 15 h.

[0062] In some examples, in the method for preparing a gas diffusion layer, preparing a hydrophobic substrate layer comprises the following steps:

[0063] The substrate is treated with a hydrophobic suspension and dried to form a hydrophobic surface layer on the substrate to obtain a hydrophobic substrate layer. In other words, the hydrophobic substrate layer includes a substrate and a hydrophobic surface layer disposed on the substrate. Further, a microporous layer is disposed on the hydrophobic surface layer. Further, one or two surfaces of the substrate form a hydrophobic surface layer. Further, the microporous layer is disposed on one or two hydrophobic surface layers of the substrate.

[0064] In some of these examples, in the step of preparing the hydrophobic base layer, the mass concentration of the hydrophobic suspension is 10% to 60%.

[0065] It is understood that the mass concentration of the hydrophobic suspension includes, but is not limited to, 10%, 20%, 30%, 40%, 50%, and 60%.

[0066] In some of the examples, in the step of preparing the hydrophobic base layer, the drying temperature is 320° C. to 370° C. and the drying time is 0.5 h to 2 h.

[0067] It can be understood that in the preparation step of the hydrophobic base layer, the drying temperature includes but is not limited to 320°C, 330°C, 340°C, 350°C, 360°C, and 370°C, and the time includes but is not limited to 0.5 h, 0.8 h, 1 h, 1.5 h, 1.8 h, and 2 h.

[0068] It is understood that before drying at 320°C to 370°C, an air drying step is also included.

[0069] One embodiment of the present application provides a membrane electrode assembly, including a cathode gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer and an anode gas diffusion layer arranged in a stacked manner, at least one of the cathode gas diffusion layer and the anode gas diffusion layer is the above-mentioned gas diffusion layer or the gas diffusion layer prepared by the above-mentioned preparation method, and a microporous layer is arranged between the cathode catalyst layer or the anode catalyst layer and the hydrophobic substrate layer.

[0070] In some of the examples, in the membrane electrode assembly, the cathode catalyst layer includes at least one of Pt / C and platinum nickel catalyst. Further, the mass content of Pt in the Pt / C catalyst is 40% to 70%; further, the platinum nickel catalyst includes a 50% platinum nickel catalyst.

[0071] In some of the examples, the cathode catalyst loading in the cathode catalyst layer of the membrane electrode assembly is 0.4 mg / cm 2 ~0.6 mg / cm 2 .

[0072] It is understood that the loading amount of the cathode catalyst includes but is not limited to 0.4 mg / cm 2 , 0.5 mg / cm 2 , 0.6 mg / cm 2 Furthermore, the cathode catalyst loading in the cathode catalyst layer is 0.5 mg / cm 2 .

[0073] In some of the examples, the loading of the anode catalyst in the anode catalyst layer of the membrane electrode assembly is 2 mg / cm 2 ~2.5 mg / cm 2 .

[0074] It is understood that the loading amount of the anode catalyst includes but is not limited to 2 mg / cm2 , 2.1 mg / cm 2 , 2.2 mg / cm 2 , 2.3 mg / cm 2 , 2.4 mg / cm 2 , 2.5 mg / cm 2 Furthermore, the loading amount of the anode catalyst was 2 mg / cm 2 .

[0075] In some examples, in the membrane electrode assembly, the anode catalyst layer includes a first substrate and an anode catalyst supported on the first substrate. Further, the first substrate includes but is not limited to nickel felt; the anode catalyst includes NiFe 2 O 4 / C catalyst and at least one of NiFe LDH (NiFe layered double hydroxide). Further, NiFe 2 O 4 NiFe / C catalyst 2 O 4 The mass content is 60-90%.

[0076] In some of the examples, in the membrane electrode assembly, the anion exchange membrane includes one of SustainionX37, AemionAF2-HWP8-75, Fumion FAA-3 and PiperION.

[0077] An embodiment of the present application provides a method for preparing a membrane electrode assembly, comprising the following steps:

[0078] A cathode gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer and an anode gas diffusion layer are arranged in sequence, at least one of the cathode gas diffusion layer and the anode gas diffusion layer is the above-mentioned gas diffusion layer or the gas diffusion layer prepared by the above-mentioned preparation method, and the microporous layer is arranged between the cathode catalyst layer or the anode catalyst layer and the hydrophobic substrate layer.

[0079] In some of the examples, in the method for preparing the membrane electrode assembly, an anode catalyst is loaded on a surface of a first substrate, and a cathode catalyst is loaded on a surface of an anion exchange membrane, and then the two are bonded together.

[0080] One embodiment of the present application provides an alkaline electrolytic cell, comprising the above-mentioned membrane electrode assembly.

[0081] The alkaline electrolyzer provided in the present application comprises the above-mentioned membrane electrode assembly, which can effectively increase the OH - The transmission capacity and electron conduction capacity of the alkaline electrolyzer can be improved, the mass transfer loss can be reduced, and the voltage of the alkaline electrolyzer can be effectively reduced, so that the alkaline electrolyzer has a lower operating power.

[0082] In some of the examples, the alkaline electrolyzer further includes electrode plates, insulating sealing gaskets and end plates arranged in sequence on both sides of the membrane electrode.

[0083] In some of the examples, in the alkaline electrolytic cell, the electrolyte includes but is not limited to a potassium hydroxide solution. Further, the concentration of the electrolyte is 0.5 mol / L to 2 mol / L; optionally, the electrolyte includes a potassium hydroxide solution (1M KOH) with a concentration of 1 mol / L.

[0084] An embodiment of the present application provides a water electrolysis hydrogen production device, including the above-mentioned alkaline electrolyzer.

[0085] The alkaline electrolyzer is used to electrolyze water to produce hydrogen, which is simple to operate and has low cost.

[0086] The present application is further described in detail below in conjunction with specific implementation methods, but the implementation methods of the present application are not limited thereto.

[0087] Example 1

[0088] (1) Commercial carbon cloth was cut into 2 cm × 2 cm pieces and immersed in a PTFE suspension with a mass concentration of 40% for 5 min to ensure that there were no obvious bubbles on the surface of the carbon cloth. After drying in air for 5 min, it was placed in a muffle furnace at 370 °C and heated for 0.5 h. After cooling, a hydrophobic carbon cloth was obtained.

[0089] (2) 20 mg of carbon black Super P, 40 mg of Aemion®AP2-HNN8 anionic ionomer dispersion with a mass concentration of 5%, and 1.86 mL of ethanol were mixed and ultrasonically dispersed for 2 h to obtain a slurry; wherein the mass ratio of the anionic ionomer to the conductive material was 0.1:1; the slurry was evenly coated on a hydrophobic carbon cloth with a thickness of 1 μm, and dried in a vacuum drying oven at 60 °C for 12 h to form a microporous layer on the hydrophobic carbon cloth to obtain a gas diffusion layer.

[0090] (3) The prepared 50% platinum nickel catalyst was ultrasonically sprayed on the surface of Aemion AF2-HWP8-75 anion exchange membrane with a loading of 0.6 mg / cm 2 , to form a cathode catalyst layer; the configured 60% NiFe 2 O 4 Anode catalyst slurry was ultrasonically sprayed on nickel felt with a loading of 2.0 mg / cm 2 .

[0091] (4) Electrolytic cell assembly: The gas diffusion layer, the nickel felt, and the anion exchange membrane with a cathode catalyst layer on the surface are tightly attached to obtain a gas diffusion layer, a nickel felt (NiFe 2O 4 A membrane electrode is provided near the anion exchange membrane), the anion exchange membrane, the cathode catalyst layer and the gas diffusion layer, and polar plates, insulating sealing gaskets and end plates are symmetrically arranged on both sides of the membrane electrode from the inside to the outside to obtain an electrolytic cell.

[0092] Example 2

[0093] The method is basically the same as Example 1, except that in step (2), the mass ratio of the anionic ionomer to the conductive material is 0.2:1; the specific steps of step (2) are as follows:

[0094] (2) 20 mg of carbon black Super P, 80 mg of Aemion®AP2-HNN8 anionic ionomer dispersion with a mass concentration of 5%, and 2 mL of ethanol were mixed and ultrasonically dispersed for 2 h to obtain a slurry; wherein the mass ratio of the anionic ionomer to the conductive material was 0.2:1; the slurry was evenly coated on a hydrophobic carbon cloth with a thickness of 1 μm, and dried in a vacuum drying oven at 60 °C for 12 h to form a microporous layer on the hydrophobic carbon cloth to obtain a gas diffusion layer.

[0095] Example 3

[0096] The method is basically the same as Example 1, except that in step (2), the carbon black Super P in Example 1 is replaced with carbon nanotubes of equal mass; the specific steps of step (2) are as follows:

[0097] (2) 20 mg of carbon nanotubes, 40 mg of 5% Aemion®AP2-HNN8 anionic ionomer dispersion and 1.86 mL of ethanol were mixed and ultrasonically dispersed for 2 h to obtain a slurry; wherein the mass ratio of anionic ionomer to conductive material was 0.1:1; the slurry was evenly coated on a hydrophobic carbon cloth with a thickness of 1 μm, and dried in a vacuum drying oven at 60 °C for 12 h to form a microporous layer on the hydrophobic carbon cloth to obtain a gas diffusion layer.

[0098] Comparative Example 1

[0099] The method is basically the same as Example 1, except that step (2) of Example 1 is omitted. The specific steps are as follows:

[0100] (1) Commercial carbon cloth was cut into 2 cm × 2 cm pieces and immersed in a PTFE suspension with a mass concentration of 40% for hydrophilic treatment for 5 min to ensure that there were no obvious bubbles on the surface of the carbon cloth. After drying in air for 5 min, it was placed in a muffle furnace at 370 °C and heated for 0.5 h. After cooling, a hydrophobic carbon cloth was obtained.

[0101] (2) The prepared 50% platinum nickel catalyst was ultrasonically sprayed on the surface of Aemion AF2-HWP8-75 anion exchange membrane with a loading of 0.6 mg / cm 2 , to form a cathode catalyst layer; the configured 60% NiFe 2 O 4 Anode catalyst slurry was ultrasonically sprayed on nickel felt with a loading of 2.0 mg / cm 2 .

[0102] (3) Electrolytic cell assembly: The hydrophobic carbon cloth is used as a gas diffusion layer, and is closely attached to the nickel felt and the anion exchange membrane with a cathode catalyst layer on the surface, so as to obtain a gas diffusion layer, a nickel felt (NiFe 2 O 4 A membrane electrode is provided near the anion exchange membrane), the anion exchange membrane, the cathode catalyst layer and the gas diffusion layer, and polar plates, insulating sealing gaskets and end plates are symmetrically arranged on both sides of the membrane electrode from the inside to the outside to obtain an electrolytic cell.

[0103] Comparative Example 2

[0104] The method is basically the same as Example 1, except that in step (2), the Aemion®AP2-HNN8 anionic ionomer in Example 1 is replaced with an equal mass of polytetrafluoroethylene. Step (2) is specifically as follows:

[0105] (2) 20 mg of carbon black Super P, 40 mg of 5% polytetrafluoroethylene dispersion and 1.86 mL of ethanol were mixed and ultrasonically dispersed for 2 h to obtain a slurry; wherein the mass ratio of polytetrafluoroethylene to conductive material was 0.1:1; the slurry was evenly coated on a hydrophobic carbon cloth with a thickness of 1 μm, and dried in a vacuum drying oven at 60 °C for 12 h to form a microporous layer on the hydrophobic carbon cloth to obtain a gas diffusion layer.

[0106] Comparative Example 3

[0107] The method is basically the same as Example 1, except that the carbon cloth is not immersed in the PTFE suspension, but PTFE is added to the slurry in step (2), as follows:

[0108] (1) 20 mg of carbon black Super P, 40 mg of 5% Aemion®AP2-HNN8 anionic ionomer dispersion, 40 mg of 5% PTFE dispersion and 2 mL of ethanol were mixed and ultrasonically dispersed for 2 h to obtain a slurry; wherein the mass ratio of anionic ionomer to conductive material was 0.1:1; the slurry was uniformly coated on untreated carbon cloth with a thickness of 1 μm, and dried in a vacuum drying oven at 60 °C for 12 h to form a microporous layer on the carbon cloth to obtain a gas diffusion layer.

[0109] (2) The prepared 50% platinum nickel catalyst was ultrasonically sprayed on the surface of Aemion AF2-HWP8-75 anion exchange membrane with a loading of 0.6 mg / cm 2 , to form a cathode catalyst layer; the configured 60% NiFe 2 O 4 Anode catalyst slurry was ultrasonically sprayed on nickel felt with a loading of 2.0 mg / cm 2 .

[0110] (4) Electrolytic cell assembly: The gas diffusion layer, the nickel felt, and the anion exchange membrane with a cathode catalyst layer on the surface are tightly attached to obtain a gas diffusion layer, a nickel felt (NiFe 2 O 4 A membrane electrode is provided near the anion exchange membrane), the anion exchange membrane, the cathode catalyst layer and the gas diffusion layer, and polar plates, insulating sealing gaskets and end plates are symmetrically arranged on both sides of the membrane electrode from the inside to the outside to obtain an electrolytic cell.

[0111] According to ASTM C-611, the resistivity of the gas diffusion layer (through the plane) was tested. The test results are shown in Table 1.

[0112] Polarization curve test: At 60℃, 1 mol / L KOH, constant current mode is adopted. Starting from the battery open circuit, the current density increases by 0.1 A / cm 2 , discharge at constant current for 15 min, and record the voltage value. The operating power calculation formula is: P=UI; when the working voltage of the electrolytic cell is higher than 2.0 V, the test is terminated. The current density is 0.8 A / cm 2 The test results are shown in Table 1.

[0113] Table 1

[0114]

[0115] It can be seen from Table 1 that, compared with the comparative example, the resistivity of the gas diffusion layer prepared in each embodiment is lower, and the voltage and operating power of the electrolytic cell are lower.

[0116] The technical features of the above-described embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above-described embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0117] The above-described embodiments only express several implementation methods of the present application, which is convenient for understanding the technical solution of the present application in detail, but it cannot be understood as limiting the scope of protection of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of the present application, several modifications and improvements can be made, which all belong to the scope of protection of the present application. It should be understood that the technical solutions obtained by those skilled in the art through logical analysis, reasoning or limited experiments on the basis of the technical solutions provided in the present application are all within the scope of protection of the claims attached to the present application. Therefore, the scope of protection of the patent of this application shall be based on the content of the attached claims, and the description can be used to interpret the content of the claims.

Claims

1. A gas diffusion layer, characterized in that: The invention comprises a hydrophobic base layer and a microporous layer arranged on at least one surface of the hydrophobic base layer, wherein the microporous layer comprises a conductive material and an anionic ionomer.

2. The gas diffusion layer according to claim 1, characterized in that The anionic ionomer includes at least one of AP2-HNN8, FAA3-shredded film, PiperION A5-HCO3 and XA-9.

3. The gas diffusion layer according to claim 1, characterized in that The mass ratio of the anionic ionomer to the conductive material is 0.01-0.2:

1.

4. The gas diffusion layer according to claim 1, characterized in that The thickness of the microporous layer is 1 μm to 10 μm.

5. The gas diffusion layer according to any one of claims 1 to 4, characterized in that: The conductive material includes at least one of Super P, acetylene black, Ketjen black, carbon nanotubes and graphene.

6. The gas diffusion layer according to any one of claims 1 to 4, characterized in that: The hydrophobic base layer comprises a hydrophobic carbon substrate; and / or The thickness of the hydrophobic substrate is 0.3 mm to 0.9 mm.

7. A method for preparing a gas diffusion layer, characterized in that: The following steps are involved: The conductive material, the anionic ionomer and the solvent are mixed to prepare a slurry; The slurry is disposed on at least one surface of the hydrophobic base layer and dried to form a microporous layer on at least one surface of the hydrophobic base layer.

8. A membrane electrode assembly, characterized in that: The invention comprises a cathode gas diffusion layer, a cathode catalyst layer, an anion exchange membrane, an anode catalyst layer and an anode gas diffusion layer arranged in a stacked manner, wherein at least one of the cathode gas diffusion layer and the anode gas diffusion layer is a gas diffusion layer as described in any one of claims 1 to 6 or a gas diffusion layer prepared by the preparation method as described in claim 7, and the microporous layer is arranged between the cathode catalyst layer or the anode catalyst layer and the hydrophobic substrate layer.

9. An alkaline electrolytic cell, characterized in that: Comprising the membrane electrode assembly as claimed in claim 8.

10. A water electrolysis hydrogen production device, characterized in that: Comprising the alkaline electrolytic cell as claimed in claim 9.

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