Gas diffusion layer, preparation method thereof and water electrolysis hydrogen production device

Abstract

The invention provides a gas diffusion layer, a preparation method thereof and a water electrolysis hydrogen production device. The gas diffusion layer comprises a conductive substrate and a microporous layer combined on the conductive substrate, and materials of the microporous layer comprise a graphitized carbon material, an oxygen-rich vacancy additive and an alkali-resistant polymer. According to the gas diffusion layer, the microporous layer is arranged on the conductive substrate, the microporous layer comprises the graphitized carbon material, the oxygen-rich vacancy additive and the alkali-resistant polymer, the graphitized carbon material has a three-dimensional ordered structure of graphite, so that the graphitized carbon material has high chemical stability and oxidation resistance, and meanwhile, the oxygen-rich vacancy additive can provide oxygen vacancies; the graphitized carbon material and the oxygen-rich vacancy additive are matched with each other, so that the carbon oxidation corrosion resistance of the microporous layer is enhanced; the alkali-resistant polymer is used as a binder to bond the graphitized carbon material and the oxygen-rich vacancy additive together and bond the graphitized carbon material and the oxygen-rich vacancy additive on the conductive substrate, so that the gas diffusion layer also has good corrosion resistance in an alkaline environment, and the service life of the gas diffusion layer is prolonged.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydrogen production by water electrolysis, and particularly relates to a gas diffusion layer, a preparation method thereof and a hydrogen production device by water electrolysis. BACKGROUND

[0002] Anion exchange membrane water electrolysis (AEMWE) is an emerging hydrogen production technology that combines alkaline water electrolysis (AWE) and proton exchange membrane water electrolysis (PEMWE). As one of the core components of the membrane electrode assembly in the anion exchange membrane water electrolysis hydrogen production system, the gas diffusion layer (GDL) mainly serves as a transmission channel for gas / liquid two-phase between the bipolar plate flow field and the catalyst layer, and also serves as a bridge for current conduction and collection of electrons. At present, the cathode gas diffusion layer of the water electrolysis hydrogen production system mainly adopts a porous carbon-based material in commercial use.

[0003] However, when wind power or solar power is used to provide power for the water electrolysis hydrogen production system, a reverse current will be generated when the electrolytic cell starts or stops or the load suddenly changes in the wind-solar coupling operation process, and the cathode is in an oxidation environment, with an oxidation potential much greater than the thermodynamic stability window of carbon (<0.2 V vs. RHE). Thus, the gas diffusion layer prepared by using the porous carbon-based material is prone to carbon corrosion, and ultimately leads to a decrease in the efficiency and a shortening of the service life of the electrolytic cell. SUMMARY

[0004] Embodiments of the present application provide a gas diffusion layer, a preparation method thereof and a hydrogen production device by water electrolysis, which can improve the technical problem that the gas diffusion layer is prone to corrosion.

[0005] In a first aspect, embodiments of the present application provide a gas diffusion layer, which comprises an electrically conductive substrate and a microporous layer combined on the electrically conductive substrate, and the material of the microporous layer comprises graphitized carbon material, oxygen vacancy-rich additive and alkali-resistant polymer.

[0006] The gas diffusion layer provided by the embodiments of the present application sets the microporous layer on the electrically conductive substrate, wherein the microporous layer comprises graphitized carbon material, oxygen vacancy-rich additive and alkali-resistant polymer. The graphitized carbon material has a three-dimensional ordered structure of graphite, so it has high chemical stability and oxidation resistance. Meanwhile, the oxygen vacancy-rich additive can provide oxygen vacancies, and the graphitized carbon material and the oxygen vacancy-rich additive cooperate with each other to enhance the ability of the microporous layer to resist carbon oxidation corrosion. At the same time, the alkali-resistant polymer acts as an adhesive to bond the graphitized carbon material and the oxygen vacancy-rich additive together and to the electrically conductive substrate, so that the gas diffusion layer also has good corrosion resistance in an alkaline environment, prolonging the service life of the gas diffusion layer.

[0007] In an embodiment, the material of the electrically conductive substrate comprises at least one of carbon paper, carbon cloth and carbon felt.

[0008] Carbon paper, carbon cloth, and carbon felt all have good electrical conductivity and high porosity. Using carbon paper and / or carbon cloth as a conductive substrate to support the microporous layer can improve the conductivity and permeability of the gas diffusion layer.

[0009] In one embodiment, the surface roughness of the conductive substrate is less than or equal to 20 μm.

[0010] Reducing the surface roughness of the conductive substrate helps to reduce contact resistance and improve the conductivity of the gas diffusion layer.

[0011] In one embodiment, the thickness of the conductive substrate is 100μm to 400μm, and optionally, the thickness of the conductive substrate is 150μm to 300μm.

[0012] By controlling the thickness of the conductive substrate, the gas diffusion layer can possess mechanical strength, conductivity, and permeability.

[0013] In one embodiment, the oxygen-rich vacancy additive includes perovskite oxides and TiO2. 2-x CeO 2-x Co3O 4-x MnO 2-x and MoO 2-x At least one of them, where 0 < x < 0.5.

[0014] The formation energy of oxygen vacancies in the aforementioned metal oxides is relatively low. The formation of oxygen vacancies can cause the metal to change from a high valence state to a low valence state, thereby affecting the redox ability of the metal oxides. Applying these substances to microporous layers can effectively improve the carbon corrosion resistance of the microporous layers.

[0015] In one embodiment, the alkali-resistant polymer includes at least one of polytetrafluoroethylene, fluorinated ethylene propylene copolymer, polyvinylidene fluoride, anion exchange resin, and perfluorosulfonic acid resin.

[0016] The aforementioned substances exhibit good stability and corrosion resistance in alkaline environments, which is beneficial for improving the structural stability of the microporous layer in alkaline environments.

[0017] In one embodiment, the graphitized carbon material includes at least one of graphitized carbon black, acetylene black, graphene, and carbon nanotubes.

[0018] The aforementioned materials possess excellent electrical conductivity, which helps to improve the conductivity of the microporous layer.

[0019] In one embodiment, the graphitization degree ID / IG of the graphitized carbon material is 0.2 to 1.5; optionally, the graphitization degree ID / IG of the graphitized carbon material is 0.2 to 0.6.

[0020] By controlling the degree of graphitization ID / IG of graphitized carbon materials, the conductivity, chemical stability, and production cost of graphitized carbon materials can be effectively controlled.

[0021] In one embodiment, the mass ratio of the graphitized carbon material to the oxygen-enriched vacancy additive in the microporous layer is 1:(0.05-0.15); optionally, the mass ratio of the graphitized carbon material to the oxygen-enriched vacancy additive is 1:(0.1-0.12).

[0022] By controlling the mass ratio of graphitized carbon material to oxygen-rich vacancy additives in the microporous layer, the air permeability of the microporous layer can be effectively controlled, as well as the brittleness of the gas diffusion layer.

[0023] In one embodiment, the mass ratio of the graphitized carbon material to the alkali-resistant polymer in the microporous layer is 1:(0.1-0.5); alternatively, the mass ratio of the graphitized carbon material to the alkali-resistant polymer is 1:(0.3-0.4).

[0024] By controlling the mass ratio of graphitized carbon material to alkali-resistant polymer in the microporous layer, the microporous layer can possess good electrical conductivity, mechanical strength, and hydrophobicity.

[0025] In one embodiment, the thickness of the microporous layer is 5 μm-40 μm; alternatively, the thickness of the microporous layer is 10 μm-30 μm.

[0026] The mass transfer capacity and electrical conductivity of the microporous layer can be controlled by adjusting its thickness.

[0027] Secondly, embodiments of this application provide a method for preparing a gas diffusion layer, used to prepare the aforementioned gas diffusion layer, the method comprising: Provide a conductive substrate; A slurry is provided, the slurry comprising a solvent, a pore-forming agent, a graphitized carbon material, an oxygen-enriched vacancy additive, and an alkali-resistant polymer; The slurry is subjected to a film-forming process on the conductive substrate to obtain a wet film layer attached to the conductive substrate. The wet film layer is dried and sintered to remove the solvent and pore-forming agent from the wet film layer, so that the wet film layer is formed into a microporous layer, thereby obtaining a gas diffusion layer.

[0028] The embodiments of this application utilize a pore-forming agent to prepare a microporous layer, which is a simple method and facilitates control of the porosity of the microporous layer.

[0029] In one embodiment, the solvent includes at least one selected from water, ethanol, ethylene glycol, n-propanol, and isopropanol.

[0030] The solvents mentioned above have low boiling points, which allows them to evaporate from the wet film layer relatively quickly during the drying process.

[0031] In one embodiment, the pore-forming agent includes at least one selected from ammonium carbonate, ammonium bicarbonate, ammonium oxalate, and ammonium chloride.

[0032] The aforementioned pore-forming agent can decompose into gas when heated, thereby leaving pores in the material matrix and forming a relatively controllable porous material.

[0033] In one embodiment, the mass ratio of the graphitized carbon material to the solvent in the slurry is 1:(10-20), or alternatively, the mass ratio of the graphitized carbon material to the solvent is 1:(12-15).

[0034] The viscosity of the slurry can be controlled by adjusting the mass ratio of graphitized carbon material to solvent in the slurry, thereby controlling the forming effect of the wet film layer.

[0035] In one embodiment, the mass ratio of the graphitized carbon material to the pore-forming agent in the slurry is 1:(0.02-0.05), or optionally, the mass ratio of the graphitized carbon material to the pore-forming agent is 1:(0.03-0.04).

[0036] By controlling the mass ratio of graphitized carbon material to pore-forming agent in the slurry, the porosity of the microporous layer can be controlled, thereby controlling the permeability of the gas diffusion layer.

[0037] In one embodiment, the film-forming process includes at least one of slot coating, blade coating, screen printing, and transfer printing.

[0038] In one embodiment, the drying process and the sintering process are performed under a vacuum or an inert atmosphere.

[0039] Drying and sintering processes typically require heating. By performing drying and sintering processes under a vacuum or inert atmosphere, the risk of graphitized carbon materials being oxidized can be reduced.

[0040] In one embodiment, the thickness of the wet film layer is 10 μm-50 μm; alternatively, the thickness of the wet film layer is 20 μm-40 μm.

[0041] The thickness of the wet film layer determines the thickness of the micropores, and the thickness of the micropore layer is controlled by controlling the thickness of the wet film layer.

[0042] In one embodiment, the sintering process is a programmed temperature rise sintering process.

[0043] During the programmed heating sintering process, as the temperature gradually increases, the pore-forming agent gradually decomposes thermally, which can effectively reduce the risk of the pore structure in the microporous layer collapsing.

[0044] In one embodiment, the programmed temperature rise sintering process includes multiple sub-sintering stages with sequentially increasing sintering temperatures; the temperature difference between two adjacent sub-sintering stages is 50°C to 100°C.

[0045] In one embodiment, the sintering temperature range of the programmed temperature rise sintering process is 100°C to 500°C.

[0046] Within this range, the pore-forming agent can be effectively thermally decomposed while maintaining the stability of the alkali-resistant polymer.

[0047] In one embodiment, the method for preparing the gas diffusion layer further includes: The conductive substrate is subjected to acid washing treatment; The conductive substrate is immersed in a first solution containing water and a surfactant.

[0048] Pickling and immersion treatments can remove impurities such as dust and oxides from the surface of the conductive substrate and activate the surface of the conductive substrate, thereby improving the bonding force between the conductive substrate and the microporous layer.

[0049] In one embodiment, the surfactant includes at least one selected from polyvinylpyrrolidone, γ-aminopropyltriethoxysilane, γ-glycidoxypropyltrimethoxysilane, and γ-methacryloyloxypropyltrimethoxysilane.

[0050] In one embodiment, the surfactant content in the first solution is 1wt% to 5wt%.

[0051] Thirdly, embodiments of this application provide an electrolytic water hydrogen production apparatus, including the gas diffusion layer described above, or the gas diffusion layer prepared by the above preparation method.

[0052] In one embodiment, the water electrolysis hydrogen production device is an anion exchange membrane water electrolysis hydrogen production device. Attached Figure Description

[0053] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0054] Figure 1 This is a schematic cross-sectional view of the gas diffusion layer provided in an embodiment of this application; Figure 2 These are steady-state performance test graphs of Examples 1 to 6 and Comparative Examples 1 and 2 of this application. Detailed Implementation

[0055] The technical solutions in the embodiments of this application will be clearly and completely described below with reference to the embodiments of this application. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application. In addition, it should be understood that the specific implementation methods described herein are only for illustration and explanation of this application and are not intended to limit this application.

[0056] In this application, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in its actual use or operating state; while "inner" and "outer" refer to the outline of the device. Furthermore, in the description of this application, the term "comprising" means "including but not limited to". The terms first, second, third, etc., are used merely as illustrative purposes and do not impose numerical requirements or establish an order.

[0057] In this application, "and / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can represent: A existing alone, A and B existing simultaneously, or B existing alone. A and B can be singular or plural.

[0058] In this application, "at least one" means one or more, and "more than one" means two or more. "One or more", "at least one of the following", or similar expressions refer to any combination of these items, including any combination of single or multiple items. For example, "at least one of a, b, or c", or "at least one of a, b, and c" can both mean: a, b, c, ab (i.e., a and b), ac, bc, or abc, where a, b, and c can be single or multiple.

[0059] Various embodiments of this application may exist in the form of a range; it should be understood that the description in the form of a range is merely for convenience and brevity and should not be construed as a hard limitation on the scope of this application; therefore, it should be considered that the range description has specifically disclosed all possible sub-ranges and single numerical values ​​within that range. For example, it should be considered that the range description from 1 to 6 has specifically disclosed sub-ranges such as from 1 to 3, from 1 to 4, from 1 to 5, from 2 to 4, from 2 to 6, from 3 to 6, etc., and single numbers within the range, such as 1, 2, 3, 4, 5, and 6, regardless of the range. Furthermore, whenever a numerical range is referred to herein, it means including any referenced number (fraction or integer) within the referred range.

[0060] Hydrogen production through water electrolysis is a green hydrogen production technology that uses electricity to decompose water molecules into hydrogen (H2) and oxygen (O2). Common types of water electrolysis hydrogen production technologies include alkaline water electrolysis (AWE), proton exchange membrane water electrolysis (PEM), and anion exchange membrane water electrolysis (AEMWE).

[0061] Some embodiments of this application provide a water electrolysis hydrogen production apparatus. The core equipment of the water electrolysis hydrogen production apparatus is an electrolyzer. The electrolyzer mainly includes a cathode, an anode, and a diaphragm, with the cathode and anode arranged opposite each other, and the diaphragm located between the cathode and anode. The type of diaphragm varies depending on the type of electrolyzer. When the electrolyzer is an alkaline electrolyzer, the diaphragm is a porous diaphragm that allows OH- to pass through. - Ions pass through; when the electrolyzer is a proton exchange membrane (PEM) electrolyzer, the diaphragm is a proton exchange membrane, allowing H+ to pass through. + Ions pass through; when the electrolyzer is an anion exchange membrane (AEMWE) electrolyzer, the diaphragm is an anion exchange membrane, allowing OH- to pass through. - Ions pass through.

[0062] In an electrolyzer, when an electric current passes through, water molecules are broken down into hydrogen ions (H+). + ) and hydroxide ions (OH) - At the cathode (negative electrode), hydrogen ions are reduced to hydrogen gas; at the anode (positive electrode), hydroxide ions are oxidized to oxygen gas, i.e., the oxygen evolution reaction (OER) occurs at the anode and the hydrogen evolution reaction (HER) occurs at the cathode.

[0063] When electrolyzing water to produce hydrogen, the electrolyte used in the water electrolysis device can be water or an alkaline aqueous solution, i.e., an alkaline solution.

[0064] In some embodiments of this application, the water electrolysis hydrogen production device is an anion exchange membrane water electrolysis hydrogen production device, that is, the water electrolysis hydrogen production device includes an anion exchange membrane. In the water electrolysis hydrogen production device, the anion exchange membrane is OH... - The anion exchange membrane is a type of hydrogen-oxygen anion exchange membrane. In water electrolysis hydrogen production devices, the anion exchange membrane can conduct hydroxide ions, causing them to migrate from the cathode side to the anode side, thus improving the efficiency of the water electrolysis process. The anion exchange membrane also plays a role in physical isolation in water electrolysis hydrogen production devices, preventing hydrogen and oxygen from mixing on both sides of the membrane, thereby improving the safety of the water electrolysis process.

[0065] In some embodiments of this application, the anode includes an anode catalyst layer, which is the primary site for the oxygen evolution reaction. The anode catalyst layer is typically composed of a non-precious metal or its oxide, such as nickel-iron (Ni-Fe), nickel-molybdenum (Ni-Mo), nickel-cobalt (Ni-Co), etc.

[0066] In some embodiments of this application, the cathode includes a cathode catalyst layer, which is the main site where the hydrogen evolution reaction occurs. The material of the cathode catalyst layer can be selected from noble metal-based catalysts, such as Pt / C, or from non-noble metal-based catalysts, such as Ni, NiMo, NiP, etc.

[0067] In some embodiments of this application, the water electrolysis hydrogen production apparatus further includes a gas diffusion layer (GDL). Specifically, the gas diffusion layer includes an anode gas diffusion layer and a cathode gas diffusion layer. The anode gas diffusion layer is located on the side of the anode catalyst layer away from the anion exchange membrane, and the cathode gas diffusion layer is located on the side of the cathode catalyst layer away from the anion exchange membrane. The anode gas diffusion layer can assist gaseous products (such as oxygen) on the anode catalyst layer to diffuse rapidly from and be discharged from the anode catalyst layer. The anode gas diffusion layer can also assist in the transport of electrolyte to the anode catalyst layer, ensuring an adequate supply of reactants. The cathode gas diffusion layer can assist gaseous products (such as hydrogen) on the cathode catalyst layer to diffuse rapidly from and be discharged from the cathode catalyst layer. The cathode gas diffusion layer can also assist in the transport of electrolyte to the cathode catalyst layer, ensuring an adequate supply of reactants. Exemplarily, the gas diffusion layer is made of a carbon-based material, thus giving the gas diffusion layer good electrical conductivity and gas permeability. It can be seen that the catalytic layer (including the cathode catalytic layer and the anode catalytic layer) and the gas diffusion layer work together in the process of hydrogen production by water electrolysis. The catalytic layer is responsible for accelerating the reaction, while the gas diffusion layer is responsible for the transport of gas and liquid. The two work together to ensure the high efficiency of the electrolysis reaction.

[0068] In some embodiments of this application, the water electrolysis hydrogen production device further includes a bipolar plate, which includes a first electrode plate and a second electrode plate. The first electrode plate is located on the side of the anode catalyst layer away from the anion exchange membrane, and the anode gas diffusion layer is located between the first electrode plate and the anode catalyst layer. The second electrode plate is located on the side of the cathode catalyst layer away from the anion exchange membrane, and the cathode gas diffusion layer is located between the second electrode plate and the cathode catalyst layer.

[0069] Please see Figure 1 Some embodiments of this application provide a gas diffusion layer 10 for use in a water electrolysis hydrogen production device. The gas diffusion layer 10 includes a conductive substrate 1 and a microporous layer 2 bonded to the conductive substrate 1. The material of the microporous layer 2 includes graphitized carbon material, oxygen-rich vacancy additives, and alkali-resistant polymers.

[0070] The gas diffusion layer 10 includes a conductive substrate 1. The conductive substrate 1 is made of a conductive material, thereby making the gas diffusion layer 10 conductive to conduct and collect electrons. Optionally, the conductive substrate 1 may be made of a carbon-based material. Carbon-based materials not only have good conductivity but also a porous structure, making the conductive substrate 1 permeable to air, thus facilitating the transport of gas and liquid on the gas diffusion layer 10. As an example, the carbon-based material includes at least one of carbon paper, carbon cloth, and carbon felt.

[0071] The gas diffusion layer 10 also includes a microporous layer 2, which is bonded to the conductive substrate 1. As an example, the microporous layer 2 is attached to one side surface of the conductive substrate 1, or to both opposite surfaces of the conductive substrate 1. The microporous layer 2 refers to a material layer with abundant internal channels. Thanks to the channels within the microporous layer 2, it exhibits good gas permeability, thereby improving the gas-liquid transport effect of the gas diffusion layer 10.

[0072] Specifically, the material of the microporous layer 2 includes graphitized carbon material, oxygen-rich vacancy additives, and alkali-resistant polymers.

[0073] Graphitized carbon materials are produced by transforming non-graphitic carbon materials into carbon materials with a graphite structure through high-temperature heat treatment (greater than or equal to 1000℃). Graphitized carbon materials possess the three-dimensional ordered structure of graphite, giving them high chemical stability and oxidation resistance; that is, graphitized carbon materials can improve resistance to carbon corrosion and oxidation. Introducing graphitized carbon materials into the microporous layer 2 can enhance the carbon corrosion resistance of the microporous layer 2 and improve the stability of the gas diffusion layer 10. Furthermore, graphitized carbon materials can also provide excellent electron channels for the microporous layer 2.

[0074] However, non-graphite carbon materials may struggle to completely eliminate amorphous carbon or defect areas during high-temperature heat treatment, resulting in insufficient localized corrosion resistance in the resulting graphitized carbon material. Carbon corrosion can still occur during the use of the microporous layer 2, leading to degradation of the mechanical properties and reduced electrical conductivity of the gas diffusion layer 10.

[0075] Therefore, in this embodiment of the application, an oxygen-rich vacancy additive is added to the microporous layer 2. The oxygen-rich vacancy additive can provide oxygen vacancies, which can effectively block electron transport by enhancing oxygen adsorption and electron capture, thereby enhancing the ability of the microporous layer 2 to resist carbon corrosion.

[0076] The microporous layer 2 also includes an alkali-resistant polymer, which acts as a binder to bond the graphitized carbon material and the oxygen-rich vacancy additive together, giving the microporous layer 2 good mechanical strength. Simultaneously, the alkali-resistant polymer also bonds the microporous layer 2 to the conductive substrate 1. The alkali-resistant polymer is a stable polymer that exists in alkaline environments, thus giving the gas diffusion layer 10 good corrosion resistance even in alkaline environments, extending the service life of the gas diffusion layer 10.

[0077] In summary, the gas diffusion layer 10 provided in this application embodiment has a microporous layer 2 formed on a conductive substrate 1. The microporous layer 2 includes graphitized carbon material, oxygen-enriched vacancy additive, and alkali-resistant polymer. The graphitized carbon material has a three-dimensional ordered structure of graphite, which gives it high chemical stability and oxidation resistance. At the same time, the oxygen-enriched vacancy additive can provide oxygen vacancies. The graphitized carbon material and the oxygen-enriched vacancy additive work together to enhance the ability of the microporous layer 2 to resist carbon oxidation corrosion. Meanwhile, the alkali-resistant polymer acts as a binder to bond the graphitized carbon material and the oxygen-enriched vacancy additive together and onto the conductive substrate 1. This allows the gas diffusion layer 10 to have good corrosion resistance even in alkaline environments, thus extending the service life of the gas diffusion layer 10.

[0078] In some embodiments of this application, the material of the conductive substrate 1 includes at least one of carbon paper, carbon cloth, and carbon felt. Carbon paper, carbon cloth, and carbon felt all have good conductivity and high porosity. Using carbon paper and / or carbon cloth as the conductive substrate 1 to support the microporous layer 2 can improve the conductivity and permeability of the gas diffusion layer 10.

[0079] In some embodiments of this application, the surface roughness of the conductive substrate 1 is less than or equal to 20 μm. Reducing the surface roughness of the conductive substrate 1 helps to reduce contact resistance and improve the conductivity of the gas diffusion layer 10. As an example, the surface roughness of the conductive substrate 1 is 1 μm, 2 μm, 5 μm, 10 μm, 15 μm, or 20 μm.

[0080] In some embodiments of this application, the thickness of the conductive substrate 1 is 100 μm to 400 μm. A larger thickness of the conductive substrate 1 results in higher mechanical strength, better supporting the microporous layer 2; however, an excessively thick conductive substrate 1 increases mass transfer resistance and lengthens the electron conduction path. Optionally, the thickness of the conductive substrate 1 is 150 μm to 300 μm. By controlling the thickness of the conductive substrate 1, the gas diffusion layer 10 can possess mechanical strength, conductivity, and gas permeability.

[0081] As an example, the thickness of the conductive substrate 1 is any one or any two of 100 μm, 150 μm, 200 μm, 250 μm, 300 μm, 350 μm and 400 μm.

[0082] In some embodiments of this application, the oxygen-vacancy-enriched additives include perovskite oxides and TiO₂. 2-x CeO 2-x Co3O 4-x MnO 2-x and MoO 2-x At least one of them, where 0 < x < 0.5.

[0083] For example, x is 0.01, 0.1, 0.15, 0.20, 0.25, 0.30, 0.35, 0.40, or 0.49.

[0084] In metal oxides, oxygen vacancies arise from the absence of oxygen atoms in the crystal structure, leading to vacancies in the crystal lattice. The formation energy of oxygen vacancies in the aforementioned metal oxides is relatively low. The formation of oxygen vacancies causes the metal to transition from a high valence state to a low valence state, thus affecting the redox properties of the metal oxide. Applying these substances to microporous layers can effectively improve their resistance to carbon corrosion.

[0085] In some embodiments of this application, the alkali-resistant polymer includes at least one of polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer, polyvinylidene fluoride (PVDF), anion exchange resin, and perfluorosulfonic acid resin. Alkali-resistant polymers refer to polymer materials that exhibit good stability and corrosion resistance in alkaline environments. Polytetrafluoroethylene (PTFE), fluorinated ethylene propylene copolymer, and polyvinylidene fluoride (PVDF) all possess excellent alkali resistance, remaining stable for extended periods in alkaline environments with a pH of 8-12, and maintaining stability even after short-term contact under strongly alkaline conditions (such as concentrated sodium hydroxide solution). Anion exchange resins, such as hydroxide-type anion exchange resins, also exhibit good stability in alkaline environments. Perfluorosulfonic acid resins possess excellent chemical corrosion resistance, including resistance to strong acids and strong alkalis. Applying these substances to microporous layers can effectively improve the structural stability of the microporous layers in alkaline environments.

[0086] In some embodiments of this application, the graphitized carbon material includes at least one of graphitized carbon black, acetylene black, graphene, and carbon nanotubes. These materials possess excellent electrical conductivity, thereby enhancing the conductivity of the microporous layer.

[0087] In some embodiments of this application, the graphitization degree ID / IG of the graphitized carbon material is 0.2 to 1.3. The graphitization degree ID / IG is an important indicator characterizing the degree of graphitization of carbon materials. A smaller value generally indicates a higher degree of graphitization, resulting in lower structural defects and disorder. In other words, a larger ID / IG value indicates a lower degree of graphitization and more defects in the graphitized carbon material, leading to poorer electrical conductivity and reduced resistance to oxidation and corrosion. However, a smaller ID / IG value increases the difficulty of preparing the graphitized carbon material, resulting in higher production costs. Optionally, the graphitization degree ID / IG of the graphitized carbon material is 0.2 to 0.6. By controlling the graphitization degree ID / IG of the graphitized carbon material, the electrical conductivity, chemical stability, and production cost can be effectively controlled.

[0088] As an example, the graphitization degree ID / IG of graphitized carbon materials is a range of any one or any two of the following: 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, 1.0, 1.1, 1.2 and 1.3.

[0089] In some embodiments of this application, the mass ratio of graphitized carbon material to oxygen-enriched vacancy additive in the microporous layer 2 is 1:(0.05-0.15). An excessively high mass ratio of graphitized carbon material to oxygen-enriched vacancy additive in the microporous layer 2 can lead to an imbalance in the pore size distribution, potentially clogging the pores and reducing effective gas transport channels. It can also increase the brittleness of the gas diffusion layer 10, weakening the flexibility and compressive strength of the conductive substrate 1. Optionally, the mass ratio of graphitized carbon material to oxygen-enriched vacancy additive is 1:(0.1-0.12). By controlling the mass ratio of graphitized carbon material to oxygen-enriched vacancy additive in the microporous layer 2, the permeability of the microporous layer 2 can be effectively controlled, as can the brittleness of the gas diffusion layer 10.

[0090] As an example, in the microporous layer 2, the mass ratio of graphitized carbon material to oxygen-rich vacancy additive is 1:0.05, 1:0.06, 1:0.07, 1:0.08, 1:0.09, 1:0.10, 1:0.11, 1:0.12, 1:0.13, 1:0.14 or 1:0.15.

[0091] In some embodiments of this application, the mass ratio of graphitized carbon material to alkali-resistant polymer in the microporous layer 2 is 1:(0.1-0.5). As an organic compound, the alkali-resistant polymer has poor electrical conductivity and insufficient hydrophilicity. Excessive content of the alkali-resistant polymer in the microporous layer 2 will reduce its conductivity and make the gas diffusion layer 10 overly hydrophobic. However, as a binder, insufficient content of the alkali-resistant polymer in the microporous layer 2 will affect its strength. Optionally, the mass ratio of graphitized carbon material to alkali-resistant polymer is 1:(0.3-0.4). By controlling the mass ratio of graphitized carbon material to alkali-resistant polymer in the microporous layer 2, the microporous layer 2 can possess good electrical conductivity, mechanical strength, and hydrophobicity.

[0092] As an example, in the microporous layer 2, the mass ratio of graphitized carbon material to alkali-resistant polymer is 1:0.1, 1:0.15, 1:0.2, 1:0.25, 1:0.3, 1:0.35, 1:0.4, 1:0.45 or 1:0.5.

[0093] In some embodiments of this application, the thickness of the microporous layer 2 is 5 μm-40 μm. The thickness of the microporous layer 2 affects its mass transfer resistance and the electron conduction path within it, thereby affecting the durability and mass transfer efficiency of the electrolyzer. Optionally, the thickness of the microporous layer 2 is 10 μm-30 μm. By controlling the thickness of the microporous layer 2, its mass transfer capacity and conductivity can be controlled.

[0094] As an example, the thickness of the microporous layer 2 is any one or a range between any two of 5μm, 10μm, 15μm, 20μm, 25μm, 30μm, 35μm and 40μm.

[0095] Some embodiments of this application also provide a method for preparing a gas diffusion layer 10, which is used to prepare the gas diffusion layer 10. The method for preparing the gas diffusion layer 10 includes: S1, Provide a conductive substrate 1; S2. Provide a slurry containing solvent, pore-forming agent, graphitized carbon material, oxygen-enriched vacancy additive and alkali-resistant polymer; S3. The slurry is subjected to film formation treatment on the conductive substrate 1 to obtain a wet film layer attached to the conductive substrate 1. S4. The wet film layer is dried and sintered to remove the solvent and pore-forming agent in the wet film layer, so that the wet film layer is formed into a microporous layer 2, and then a gas diffusion layer 10 is obtained.

[0096] The embodiments of this application utilize a pore-forming agent to prepare the microporous layer 2, which is a simple method and facilitates control of the porosity of the microporous layer 2.

[0097] In the preparation of microporous layer 2, the pore-forming agent plays a site-occupying role. First, the solvent, pore-forming agent, and raw materials of microporous layer 2 are mixed to form a slurry. Then, the slurry is made into a wet film layer, which can be understood as containing both solvent and pore-forming agent. After that, the wet film layer is dried. During the drying process, the solvent in the wet film layer evaporates first, resulting in a dry film layer. The dry film layer still contains the pore-forming agent, which is dispersed inside the dry film layer. The dry film layer is then sintered at a high temperature. During this process, the pore-forming agent undergoes thermal decomposition and forms a gaseous wet film. The positions originally occupied by the pore-forming agent in the dry film layer are formed into pores, thus forming microporous layer 2, and finally obtaining gas diffusion layer 10.

[0098] In some embodiments of this application, in step S2, the solvent includes at least one selected from water, ethanol, ethylene glycol, n-propanol, and isopropanol. These solvents have low boiling points, allowing them to evaporate quickly from the wet film layer during the drying process.

[0099] In some embodiments of this application, the pore-forming agent includes at least one selected from ammonium carbonate, ammonium bicarbonate, ammonium oxalate, and ammonium chloride. The thermal decomposition products of ammonium carbonate and ammonium bicarbonate are ammonia (NH3), carbon dioxide (CO2), and water (H2O); the thermal decomposition products of ammonium oxalate are ammonia (NH3), carbon dioxide (CO2), and carbon monoxide (CO); and the thermal decomposition products of ammonium chloride are ammonia (NH3) and hydrogen chloride (HCl). It can be seen that the thermal decomposition products of the above-mentioned pore-forming agents are all gases, which can reduce the residual impurities in the microporous layer 2.

[0100] In some embodiments of this application, the mass ratio of graphitized carbon material to solvent in the slurry is 1:(10-20). It can be seen that the amount of solvent used is greater than the amount of graphitized carbon material. By controlling the mass ratio of graphitized carbon material to solvent in the slurry, the viscosity of the slurry can be controlled, thereby controlling the forming effect of the wet film layer. Optionally, the mass ratio of graphitized carbon material to solvent is 1:(12-15).

[0101] As an example, the mass ratio of graphitized carbon material to solvent in the slurry is 1:10, 1:11, 1:12, 1:13, 1:14, 1:15, 1:16, 1:17, 1:18, 1:19 or 1:20.

[0102] In some embodiments of this application, the mass ratio of graphitized carbon material to pore-forming agent in the slurry is 1:(0.02-0.05). The pores in the microporous layer 2 are vacancies left after the decomposition of the pore-forming agent; therefore, the mass proportion of the pore-forming agent in the slurry affects the porosity of the final microporous layer 2. By controlling the mass ratio of graphitized carbon material to pore-forming agent in the slurry, the porosity of the microporous layer 2 can be controlled, thereby controlling the permeability of the gas diffusion layer 10. Optionally, the mass ratio of graphitized carbon material to pore-forming agent is 1:(0.03-0.04).

[0103] As an example, the mass ratio of graphitized carbon material to pore-forming agent in the slurry is 1:0.02, 1:0.025, 1:0.03, 1:0.035, 1:0.04, 1:0.045 or 1:0.05.

[0104] In some embodiments of this application, the film-forming process includes at least one of slot coating, blade coating, screen printing, and transfer printing.

[0105] In some embodiments of this application, the drying and sintering processes are performed under a vacuum or inert atmosphere. Drying and sintering processes typically require heating; performing them under a vacuum or inert atmosphere reduces the risk of oxidation of the graphitized carbon material.

[0106] In some embodiments of this application, the thickness of the wet film layer is 10 μm-50 μm. The thickness of the wet film layer determines the thickness of the micropores 2, and the thickness of the microporous layer 2 is controlled by controlling the thickness of the wet film layer. Optionally, the thickness of the wet film layer is 20 μm-40 μm.

[0107] As an example, the thickness of the wet film layer is any one or a range between any two of 10 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm and 50 μm.

[0108] In some embodiments of this application, the sintering process is a programmed temperature rise sintering process. During programmed temperature rise sintering, the temperature gradually increases, and the pore-forming agent gradually decomposes with the temperature. This can effectively reduce the risk of collapse of the pore structure in the microporous layer 2 and give the gas diffusion layer 10 excellent mechanical properties.

[0109] In some embodiments of this application, the programmed temperature rise sintering process includes multiple sub-sintering stages with sequentially increasing sintering temperatures; the temperature difference between two adjacent sub-sintering stages is 50°C to 100°C. As an example, the temperature difference between two adjacent sub-sintering stages is 50°C, 60°C, 70°C, 80°C, 90°C, or 100°C. Optionally, the number of sub-sintering stages is 2 to 6, for example, 2, 3, 4, 5, or 6.

[0110] In some embodiments of this application, the sintering temperature range of the programmed temperature rise sintering process is 100°C to 500°C. Within this range, the pore-forming agent can be effectively thermally decomposed while maintaining the stability of the alkali-resistant polymer. As an example, the sintering temperature range is any value between two of 100°C, 150°C, 200°C, 250°C, 300°C, 350°C, 400°C, 450°C, and 500°C.

[0111] In some embodiments of this application, the method for preparing the gas diffusion layer further includes: S11. Perform acid washing treatment on conductive substrate 1; S12. The conductive substrate 1 is immersed in a first solution containing water and a surfactant. Pickling and immersion treatments can remove impurities such as dust and oxides from the surface of the conductive substrate 1 and activate the surface of the conductive substrate 1, thereby improving the bonding force between the conductive substrate 1 and the microporous layer 2.

[0112] In some embodiments of this application, the surfactant includes at least one selected from polyvinylpyrrolidone (PVP), γ-aminopropyltriethoxysilane (SKH-550), γ-glycidoxypropyltrimethoxysilane (KH-560), and γ-methacryloyloxypropyltrimethoxysilane (KH-570).

[0113] In some embodiments of this application, the surfactant content in the first solution is 1 wt% to 5 wt%. As an example, the surfactant content in the first solution is 1 wt%, 2 wt%, 3 wt%, 4 wt%, or 5 wt%.

[0114] The following description is based on specific embodiments.

[0115] Example 1 Example 1 provides a gas diffusion layer, the preparation method of which includes the following steps: S1. Surface treatment of conductive substrate: Carbon paper with a thickness of 180μm (surface roughness of 15μm) was selected as the conductive substrate and ultrasonically cleaned in a weakly acidic solution with pH=5 for 30 min. After drying under vacuum at 80℃ for 10 min, it was immersed in a 3wt% KH-550 (γ-aminopropyltriethoxysilane) silane coupling agent solution (solvent is ethanol) for 60 min. After drying again, the surface-treated conductive substrate was obtained.

[0116] S2, Preparation of microporous layer slurry: 10g carbon nanotubes (I D / I G =0.55), 1.1g CeO2 oxygen-enriched vacancy additive, 5.8g PTFE emulsion (60wt%), 130g ethylene glycol solvent, 0.35g NH4HCO3 pore-forming agent, ultrasonically dispersed for 2h and then magnetically stirred for 4h to form a homogeneous slurry.

[0117] S3. Coating and sintering: A 25μm thick microporous slurry is coated on the surface-treated substrate using a scraper method. After drying and molding at 120℃ in a vacuum environment, the substrate is sintered by step temperature increase: 120℃ (1h) → 180℃ (1h) → 240℃ (1h) → 300℃ (1h) to obtain a gas diffusion layer.

[0118] Example 2 Example 2 provides a gas diffusion layer. The preparation method of the gas diffusion layer can be found in Example 1. The difference between Example 2 and Example 1 is that the amount of CeO2 is adjusted to 1g, so the mass ratio of carbon nanotubes to CeO2 is 1:0.1.

[0119] Example 3 Example 3 provides a gas diffusion layer. The preparation method of the gas diffusion layer can be found in Example 1. The difference between Example 3 and Example 1 is that the amount of PTFE emulsion (60wt%) is adjusted to 6.7g, so the mass ratio of carbon nanotubes to PTFE is 1:0.4.

[0120] Example 4 Example 4 provides a gas diffusion layer. The preparation method of the gas diffusion layer can be found in Example 1. The difference between Example 4 and Example 1 is that the amount of ethylene glycol is adjusted to 150g, so the mass ratio of carbon nanotubes to ethylene glycol is 1:15.

[0121] Example 5 Example 5 provides a gas diffusion layer. The preparation method of the gas diffusion layer can be found in Example 1. The difference between Example 5 and Example 1 is that the amount of NH4HCO3 is adjusted to 4g, so the mass ratio of carbon nanotubes to NH4HCO3 is 1:0.4.

[0122] Example 6 Example 6 provides a gas diffusion layer. The preparation method of the gas diffusion layer can be found in Example 1. The difference between Example 6 and Example 1 is that in S3, a 30 μm thick microporous slurry is coated on the surface-treated substrate using a doctor blade method.

[0123] Comparative Example 1 Comparative Example 1 provides a gas diffusion layer, the preparation method of which can be found in Example 1. The difference between Comparative Example 1 and Example 1 is that: the carbon nanotubes I D / I G =0.55, and the oxygen-enriched vacancy additive CeO2 is removed from S2.

[0124] Comparative Example 2 Comparative Example 2 provides a gas diffusion layer, which is a carbon paper with a thickness of 180 μm and a surface roughness of 15 μm.

[0125] Performance testing: 1. Test Objects: The gas diffusion layers and single-cell electrolyzers prepared in Examples 1-6 and Comparative Examples 1-2 were used as test objects. The preparation method of the single-cell electrolyzer is as follows: end plate, current collector, cathode flow field, cathode gas diffusion layer (the gas diffusion layers prepared in Examples 1-6 and Comparative Examples 1-2 were used as the cathode gas diffusion layer of the AEM single-cell electrolyzer), CCM electrode (the catalyst on the cathode side has a loading of 0.3 mg / cm³). 2 The single-cell electrolysis device is assembled sequentially with Pt / C, an integrated anode electrode, a current collector, and an anode end plate.

[0126] 2. Test items: 1) Transient performance: Using an electrochemical workstation and the step current method, the system current density was measured from 0 A / cm². 2 Increased to 2A / cm 2 Record the sample's velocity (0.5 A / cm) before and after 500 hours of operation. 2 1A / cm 2 and 2A / cm 2 The voltages corresponding to the current densities are shown in Table 1.

[0127] 2) Steady-state performance: An electrochemical workstation was used, employing the chronoamperometry method, with a start-up and shutdown cycle every 10 hours, for a total operating time of 500 hours. The system current density was 1 A / cm². 2 After data processing, the AEMWE stability curve is obtained as follows: Figure 2 As shown.

[0128] Table 1

[0129] As shown in Table 1, Example 1 exhibited the best overall performance among all examples (lowest initial voltage and lowest voltage after 500h durability testing). Example 2 reduced the CeO2 ratio. While Example 2's performance was slightly worse than Example 1, it was better than Comparative Example 1, indicating an optimal CeO2 addition amount. Too little CeO2 results in insufficient protection, while too much leads to deterioration of the microporous layer (MPL) mechanical properties. Example 3 increased the PTFE ratio. As a binder and hydrophobic agent, a higher PTFE ratio enhances the mechanical strength and hydrophobicity of the MPL layer. However, excessive PTFE may clog pores or reduce conductivity, resulting in performance comparable to Example 5, demonstrating the feasibility of this ratio. Example 4 adjusted the solvent amount. Solvent amount primarily affects slurry viscosity and coating process, ultimately influencing the microstructure and thickness of the MPL layer. Example 4's performance was comparable to Example 6, indicating a wider process window. Example 5 increased the amount of pore-forming agent. The pore-forming agent NH4HCO3 decomposes upon heating, creating pores; increasing its amount increases the porosity of the MPL, thus facilitating mass transfer. The performance of Example 5 is comparable to Example 3, demonstrating an optimized effect. Example 6 increased the coating thickness; a thicker MPL layer may provide better protection and a superior interface, but an excessively thick MPL layer may increase resistance. The performance of Example 6 is comparable to Example 4, indicating that 25 μm and 30 μm are effective thickness choices.

[0130] Table 1 also shows that Comparative Example 1, which omitted the oxygen-enriched vacancy additive (i.e., CeO2), exhibited slightly worse initial performance compared to Examples 1-6, with more severe performance degradation observed after 500 hours. This demonstrates the role of the oxygen-enriched vacancy additive. Comparative Example 2, lacking an MPL layer, showed significantly lower initial and final voltages in all examples and Comparative Example 1 compared to Comparative Example 2, thus proving the effectiveness of the microporous layer.

[0131] from Figure 2 It can be seen that the composite gas diffusion layers (GDLs) prepared in all examples (1-6) exhibit significantly better performance than the gas diffusion layer of Comparative Example 1 (without oxygen-enriched vacancy additive) and Comparative Example 2 (pure carbon paper). This demonstrates that constructing a microporous layer (MPL) containing highly graphitized carbon powder, alkali-resistant polymer, and oxygen-enriched vacancy additive on a carbon paper substrate can greatly improve the overall performance of GDLs in anion exchange membrane electrolysis of water (AEMWE), especially their stability under long-term high current density operation.

[0132] The embodiments of this application have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this application. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this application. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this application. Therefore, the content of this specification should not be construed as a limitation of this application.

Claims

1. A gas diffusion layer, characterized by, The gas diffusion layer comprises an electrically conductive substrate and a microporous layer attached to the electrically conductive substrate, and the material of the microporous layer comprises graphitized carbon material, oxygen vacancy-rich additive and alkali-resistant polymer.

2. The gas diffusion layer according to claim 1, wherein The material of the electrically conductive substrate comprises at least one of carbon paper, carbon cloth and carbon felt; and / or, The surface roughness of the electrically conductive substrate is less than or equal to 20 μm; and / or, The thickness of the electrically conductive substrate is 100 μm-400 μm, and optionally, the thickness of the electrically conductive substrate is 150 μm-300 μm.

3. The gas diffusion layer according to claim 1 or 2, characterized in that, The oxygen-rich vacancy additive includes at least one of perovskite-type oxides, TiO 2-x , CeO 2-x , Co3O 4-x , MnO 2-x , and MoO 2-x , wherein 0 < x < 0.

5.

4. The gas diffusion layer according to any one of claims 1 to 3, characterized in that, The alkali-resistant polymer comprises at least one of polytetrafluoroethylene, polyvinylidene fluoride, fluorinated ethylene propylene copolymer, anion exchange resin and perfluorosulfonic acid resin; and / or, The graphitized carbon material comprises at least one of graphitized carbon black, acetylene black, graphene and carbon nanotube.

5. The gas diffusion layer according to any one of claims 1 to 4, characterized in that, The graphitization degree I of the graphitized carbon material D / I G is 0.2 to 1.5; optionally, the graphitization degree I of the graphitized carbon material D / I G is 0.2 to 0.

6.

6. The gas diffusion layer according to any one of claims 1 to 5, wherein In the microporous layer, the mass ratio of the graphitized carbon material to the oxygen vacancy-rich additive is 1:(0.05-0.15), and optionally, the mass ratio of the graphitized carbon material to the oxygen vacancy-rich additive is 1:(0.1-0.12).

7. The gas diffusion layer according to any one of claims 1 to 6, wherein In the microporous layer, the mass ratio of the graphitized carbon material to the alkali-resistant polymer is 1:(0.1-0.5), and optionally, the mass ratio of the graphitized carbon material to the alkali-resistant polymer is 1:(0.3-0.4).

8. The gas diffusion layer according to any one of claims 1 to 7, characterized by The thickness of the microporous layer is 5 μm-40 μm, and optionally, the thickness of the microporous layer is 10 μm-30 μm.

9. A method for producing a gas diffusion layer, for producing a gas diffusion layer according to any one of claims 1 to 8, characterized in that The preparation method of the gas diffusion layer comprises: providing an electrically conductive substrate; providing a slurry comprising a solvent, a pore-forming agent, graphitized carbon material, oxygen vacancy-rich additive and alkali-resistant polymer; carrying out film-forming treatment on the slurry on the electrically conductive substrate to obtain a wet film layer attached to the electrically conductive substrate; carrying out drying treatment and sintering treatment on the wet film layer to remove the solvent and the pore-forming agent in the wet film layer, so that the wet film layer is formed into a microporous layer, and then a gas diffusion layer is obtained.

10. The method for producing a gas diffusion layer according to claim 9, wherein The solvent comprises at least one of water, ethanol, ethylene glycol, n-propanol and isopropanol; and / or, The pore-forming agent comprises at least one of ammonium carbonate, ammonium bicarbonate, ammonium oxalate and ammonium chloride; and / or, In the slurry, the mass ratio of the graphitized carbon material to the solvent is 1:(10-20), and optionally, the mass ratio of the graphitized carbon material to the solvent is 1:(12-15); and / or, In the slurry, the mass ratio of the graphitized carbon material to the pore-forming agent is 1:(0.02-0.05), and optionally, the mass ratio of the graphitized carbon material to the pore-forming agent is 1:(0.03-0.04); and / or, The film-forming treatment is carried out in at least one of the following ways: slot coating, doctor blade coating, screen printing and transfer printing; and / or, The drying treatment and the sintering treatment are carried out in vacuum or in inert atmosphere; and / or, The thickness of the wet film layer is 10 μm-50 μm, and optionally, the thickness of the wet film layer is 20 μm-40 μm.

11. The method for producing a gas diffusion layer according to claim 9 or 10, characterized by, The sintering treatment is a programmed temperature sintering process.

12. The method for producing a gas diffusion layer according to claim 11, wherein The programmed temperature sintering process comprises multiple sub-sintering stages with sintering temperature rising in sequence; the temperature difference between two adjacent sub-sintering stages is 50-100 DEG C; and / or, The sintering temperature range of the programmed temperature sintering process is 100-500 DEG C.

13. The method for producing a gas diffusion layer according to any one of claims 9 to 12, characterized in that, The preparation method of the gas diffusion layer further comprises: carrying out pickling treatment on the conductive substrate; immersing the conductive substrate in a first solution comprising water and a surfactant.

14. The method for producing a gas diffusion layer according to claim 13, wherein The surfactant comprises at least one of polyvinylpyrrolidone, gamma-aminopropyl triethoxysilane, gamma-glycidoxypropyl trimethoxysilane and gamma-methacryloyloxypropyl trimethoxysilane; and / or, The content of the surfactant in the first solution is 1-5 wt%.

15. An apparatus for producing hydrogen by electrolysis of water, characterized by The gas diffusion layer comprises the gas diffusion layer according to any one of claims 1-8 or is prepared by the preparation method according to any one of claims 9-14.

16. The device for hydrogen production by water electrolysis according to claim 15, characterized in that, The water electrolysis hydrogen production device is a water electrolysis hydrogen production device with an anion exchange membrane.

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