Alkaline water electrolysis hydrogen production electrode and preparation method and application thereof

Abstract

The present application provides an alkaline water electrolysis hydrogen production electrode and its preparation method and application, which relate to the field of new energy technology. The alkaline water electrolysis hydrogen production electrode of the present application includes a support layer, a diffusion layer and a catalyst layer stacked in sequence, and the diffusion layer has a through hole that runs from the side close to the support layer to the side close to the catalyst layer. The through hole is a micropore, and the diffusion layer is treated with hydrophilic air repellency. The gas-liquid separation design of the diffusion layer significantly reduces bubble retention and concentration polarization phenomena; the through hole design optimizes the bubble discharge path, reduces the leakage of gas near the diaphragm, and reduces the oxygen in hydrogen and hydrogen in oxygen indicators; the support layer and the diffusion layer jointly protect the catalyst layer to avoid damage caused by mechanical vibration and long-term operation, and the electrode life is extended to more than 50,000 hours; the modular design is suitable for existing electrolyzer equipment and can be replaced without additional modification, and has good industrial application value.

Description

Technical Field

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

[0002] The alkaline water electrolysis hydrogen production electrolyzer is composed of several electrolysis chambers connected in series, and a single chamber contains bipolar plates, electrodes, diaphragms and seals. The electrodes can be divided into cathodes and anodes, and the catalyst layer is attached to their surfaces. It is the place where the electrochemical reaction of water electrolysis occurs, producing hydrogen and oxygen respectively. Therefore, when the cathode and anode are in contact with the electrolyte, gas will also be generated on their surface, which belongs to the catalyst layer / electrolyte / gas three-phase interface.

[0003] In the prior art, the alkaline water electrolysis hydrogen production electrode usually adopts a single-layer structure, and its substrate is mostly a nickel wire mesh, and the catalyst layer is attached to the surface by electroplating or spraying. Most of the existing electrode structures use a mesh size of 40 to 60 meshes. The gas generated during the electrolysis process easily gathers on the surface of the catalyst layer to form large bubbles, which cannot escape quickly in the form of small bubbles, resulting in the blocking of the active sites of the catalyst and reducing the efficiency of the electrochemical reaction; bubble retention will lead to insufficient contact between the electrolyte and the catalyst layer, resulting in local concentration polarization, further increasing the cell pressure and energy consumption. Summary of the invention

[0004] The purpose of the present application is to provide an alkaline water electrolysis hydrogen production electrode and a preparation method and application thereof, aiming to solve the problems of bubble retention and concentration polarization in the existing alkaline water electrolysis hydrogen production electrode.

[0005] To achieve the above objectives, the present application provides an alkaline water electrolysis hydrogen production electrode, comprising a support layer, a diffusion layer and a catalyst layer stacked in sequence; the support layer is an elastic porous material; the diffusion layer has a through hole that passes through from one side close to the support layer to the side close to the catalyst layer, the through hole is a micropore, and the diffusion layer is treated with hydrophilicity and air repellency.

[0006] In some embodiments, the thickness of the diffusion layer is in the range of 0.1 to 3.0 mm, and the porosity of the diffusion layer is in the range of 40% to 70%.

[0007] In some embodiments, the hydrophilic and air-repellent treatment comprises a chemical treatment or a physical treatment;

[0008] Optionally, the chemical treatment includes any one of pickling treatment and plasma treatment;

[0009] Optionally, the physical treatment includes any one of sand blasting and laser etching.

[0010] In some embodiments, the aperture of the through hole is designed to be gradient from a side close to the support layer to a side close to the catalyst layer;

[0011] Optionally, the pore diameter of the through hole decreases gradually from a side close to the support layer to a side close to the catalyst layer.

[0012] In some embodiments, the material of the diffusion layer is selected from any one of nickel felt, nickel dense mesh, carbon paper or carbon cloth.

[0013] In some embodiments, the material of the diffusion layer is selected from nickel felt;

[0014] Optionally, the fiber diameter of the nickel felt is less than 0.1 mm, the thickness ranges from 0.1 to 3.0 mm, and the porosity ranges from 40% to 70%.

[0015] In some embodiments, the porosity of the support layer is 80% to 95%; the thickness of the support layer is in the range of 1 to 5 mm.

[0016] In some embodiments, the material of the support layer includes any one of nickel foam, nickel punched and stretched mesh, nickel elastic mesh, nickel-iron alloy punched and stretched mesh, or stainless steel punched and stretched mesh.

[0017] In some embodiments, the catalyst layer includes any one of a thermal sprayed catalyst layer, a thermal oxidation catalyst layer, an electroplated catalyst layer, and an in-situ grown catalyst layer;

[0018] Optionally, the thermal sprayed catalyst layer comprises a Raney nickel catalyst layer;

[0019] Optionally, the Raney nickel catalyst layer includes at least one of NiAlFe and NiAlMo;

[0020] Optionally, the thermal oxidation catalyst layer includes a composite catalyst layer of noble metal elements and rare earth elements;

[0021] Optionally, the noble metal element includes at least one of Ru, Pt, and Pd; the rare earth element includes at least one of La, Ce, Pr, and Nd;

[0022] Optionally, the electroplating catalyst layer and the in-situ growth catalyst layer include a single or multiple catalyst layer of a non-noble metal element and a noble metal element;

[0023] Optionally, the non-precious metal element includes at least one of Ni, Fe, and Cr, and the precious metal element includes at least one of Ru, Pt, and Pd.

[0024] The present application also provides a method for preparing the above-mentioned alkaline water electrolysis hydrogen production electrode, comprising:

[0025] The support layer, the diffusion layer and the catalyst layer are compounded to obtain an alkaline water electrolysis hydrogen production electrode;

[0026] Alternatively, the support layer and the diffusion layer are compounded, and then the catalyst layer is prepared on the diffusion layer to obtain an alkaline water electrolysis hydrogen production electrode.

[0027] Optionally, the compounding includes at least one of pressing, welding, and rolling;

[0028] Optionally, the preparation method includes at least one of thermal spraying, thermal oxidation, electroplating, and in-situ growth.

[0029] The present application also provides an application of the alkaline water electrolysis hydrogen production electrode as described above in water electrolysis hydrogen production.

[0030] Compared with the prior art, the beneficial effects of this application include:

[0031] The alkaline water electrolysis hydrogen production electrode provided in the present application includes a support layer, a diffusion layer and a catalyst layer stacked in sequence, the diffusion layer has a through hole that runs from one side close to the support layer to the side close to the catalyst layer, the through hole is a micropore, and the diffusion layer is treated with hydrophilic and gas-repellent. The gas-liquid separation design of the diffusion layer significantly reduces bubble retention and concentration polarization. Under the same current density, the cell voltage is reduced by about 10%, and the energy consumption is reduced by about 5% to 10%; through the through hole design, the bubble discharge path is optimized, the leakage of gas near the diaphragm is reduced, and the oxygen in hydrogen and hydrogen in oxygen indicators are reduced; the support layer and the diffusion layer jointly protect the catalyst layer to avoid damage caused by mechanical vibration and long-term operation, and the electrode life is extended to more than 50,000 hours; the modular design is suitable for existing electrolyzer equipment and can be replaced without additional modification, which has good industrial application value. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present application and therefore should not be regarded as limiting the scope of the present application.

[0033] Figure 1 This is a schematic structural diagram of an embodiment of an alkaline water electrolysis hydrogen production electrode of the present application;

[0034] Figure 2 This is a schematic structural diagram of another embodiment of the alkaline water electrolysis hydrogen production electrode of the present application;

[0035] Figure 3 This is a schematic structural diagram of another embodiment of the alkaline water electrolysis hydrogen production electrode of the present application;

[0036] Figure 4 This is a schematic diagram of the structure of the electrolysis chamber of the present application.

[0037] Reference numerals:

[0038] 10-alkaline water electrolysis hydrogen production electrode; 11-support layer; 12-diffusion layer; 121-through hole; 13-catalyst layer; 20-diaphragm; 30-bipolar plate. DETAILED DESCRIPTION

[0039] As used herein:

[0040] "Prepared from" is synonymous with "comprising." As used herein, the terms "comprising," "including," "having," "containing," or any other variation thereof, are intended to cover a non-exclusive inclusion. For example, a composition, process, method, article, or apparatus that comprises the listed elements is not necessarily limited to only those elements but may include other elements not expressly listed or inherent to such composition, process, method, article, or apparatus.

[0041] The conjunction "consisting of excludes any unspecified element, step, or component. If used in a claim, this phrase renders the claim closed-ended so that it does not include materials other than those described, except for conventional impurities associated therewith. When the phrase "consisting of" appears in a clause of the body of a claim rather than immediately following the subject matter, it limits only the elements described in that clause; other elements are not excluded from the claim as a whole.

[0042] When an amount, concentration, or other value or parameter is expressed as a range, a preferred range, or a range defined by a series of upper preferred values ​​and lower preferred values, this should be understood as specifically disclosing all ranges formed by any pairing of any range upper limit or preferred value with any range lower limit or preferred value, regardless of whether the range is disclosed separately. For example, when a range of "1 to 5" is disclosed, the described range should be interpreted as including ranges "1 to 4", "1 to 3", "1 to 2", "1 to 2 and 4 to 5", "1 to 3 and 5", etc. When a numerical range is described in this article, unless otherwise stated, the range is intended to include its end values ​​and all integers and fractions within the range.

[0043] In these examples, parts and percentages are by mass unless otherwise indicated.

[0044] "Parts by mass" refers to the basic unit of measurement for expressing the mass ratio of multiple components. 1 part can represent any unit mass, such as 1g or 2.689g. If we say that the mass of component A is a parts and the mass of component B is b parts, it means the ratio of the mass of component A to the mass of component B is a:b. Alternatively, it means that the mass of component A is aK and the mass of component B is bK (K is an arbitrary number, indicating a multiple factor). It should not be misunderstood that, unlike the mass parts, the sum of the mass of all components is not limited to 100 parts.

[0045] "And / or" is used to indicate that one or both of the stated situations may occur, for example, A and / or B includes (A and B) and (A or B).

[0046] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present invention, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0047] The present application provides an alkaline water electrolysis hydrogen production electrode 10, see Figures 1 to 3 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence; the support layer 11 is an elastic porous material; the diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13, the through hole 121 is a micropore, and the diffusion layer 12 is treated with hydrophilicity and air repellency.

[0048] The alkaline water electrolysis hydrogen production electrode 10 of the present application significantly reduces bubble retention and concentration polarization through the gas-liquid separation design of the diffusion layer 12. Under the same current density, the cell voltage is reduced by about 10%, and the energy consumption is reduced by about 5% to 10%; through the design of the through hole 121, the bubble discharge path is optimized, the leakage of gas near the diaphragm is reduced, and the oxygen in hydrogen and hydrogen in oxygen indicators are reduced; the support layer 11 and the diffusion layer 12 jointly protect the catalyst layer 13 to avoid damage caused by mechanical vibration and long-term operation, and the electrode life is extended to more than 50,000 hours; the modular design is suitable for existing electrolytic cell equipment and can be replaced without additional modification, and has good industrial application value.

[0049] In some embodiments, the porosity of the support layer 11 is 80% to 95%, for example, it can be 80%, 81%, 82%, 83%, 84%, 85%, 86%, 87%, 88%, 89%, 90%, 91%, 92%, 93%, 94%, 95 or any value between 80% and 95%; the thickness of the support layer ranges from 1 to 5 mm, for example, it can be 1 mm, 2 mm, 3 mm, 4 mm, 5 mm or any value between 1 and 5 mm.

[0050] In some embodiments, the material of the support layer 11 includes any one of nickel foam, nickel punched and drawn mesh, nickel elastic mesh, nickel-iron alloy punched and drawn mesh, or stainless steel punched and drawn mesh.

[0051] Among them, nickel foam is a porous nickel material with a three-dimensional mesh structure, high porosity and large specific surface area. Nickel punching and stretching is made of nickel plate or nickel foil through mechanical punching and stretching, and has specific mechanical strength and filtering performance. Nickel elastic mesh is woven with a special crochet needle using a knitting crochet process. It is a pure nickel wire gas-liquid filter, also called a foam net, a foam capture net, a shielding net, etc., with good elasticity and filtering performance.

[0052] In some embodiments, the thickness of the diffusion layer 12 ranges from 0.1 to 3.0 mm, for example, it can be 0.1 nm, 0.5 mm, 1 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm or any value between 0.1 and 3.0 mm, and the porosity of the diffusion layer 12 is 40% to 70%, for example, it can be 40%, 41%, 42%, 43%, 44%, 45%, 46%, 47%, 18%, 19%, 50%, 51%, 52%, 53%, 54%, 55%, 56%, 57%, 58%, 59%, 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70% or any value between 40% and 70%.

[0053] In some embodiments, the material of the diffusion layer 12 is selected from any one of nickel dense mesh, nickel felt, carbon paper or carbon cloth.

[0054] Among them, the nickel dense mesh is usually made of nickel wire through a weaving process, which can be plain weave, twill weave or bamboo flower weave, etc., with stable filtering performance and fine mesh. The mesh of the nickel dense mesh is generally square holes, and the mesh number can range from 1 mesh to 330 meshes. Optionally, the mesh number of the nickel dense mesh used in this application is greater than 150 meshes.

[0055] Among them, nickel felt is a non-woven material formed by compression and entanglement of nickel fibers, with a felt-like texture. The fiber diameter of nickel felt is less than 0.1mm, and it can be made of pure nickel or nickel alloy.

[0056] Among them, carbon paper is a paper-like product made from carbon fiber (chopped carbon fiber) as the main raw material, with dispersants, binders, reinforcing agents, etc., through wet or dry papermaking process. It has the advantages of durability, high conductivity, high strength, high air permeability and corrosion resistance.

[0057] Among them, carbon cloth is a textile made of carbon fiber, which has the characteristics of high strength, high modulus, low density, etc. It not only has the intrinsic characteristics of carbon material, but also has the flexible processability of textile fiber. It has high specific strength, strong bending resistance and good creep resistance.

[0058] In some embodiments, the hydrophilic and air-repellent treatment comprises a chemical treatment or a physical treatment;

[0059] Optionally, the chemical treatment includes any one of pickling treatment and plasma treatment;

[0060] Optionally, the physical treatment includes any one of sand blasting and laser etching.

[0061] In some embodiments, see Figure 1 and Figure 2 The aperture of the through hole 121 is designed in a gradient from the side close to the support layer 11 to the side close to the catalyst layer 13. The diffusion layer 12 may include multiple layers of material, for example, two layers, three layers, four layers, five layers or more layers, each layer of material has a different porosity, and the pore size is different due to the different porosity of each layer, that is, the larger the porosity, the larger the pore size. It can be understood that the porosity of the diffusion layer 12 is designed in a gradient from the side close to the support layer 11 to the side close to the catalyst layer 13.

[0062] Optionally, see Figure 1 The pore size of the through hole 121 decreases gradually from the side close to the support layer 11 to the side close to the catalyst layer 13 , that is, the porosity of the diffusion layer 12 decreases gradually from the side close to the support layer 11 to the side close to the catalyst layer 13 .

[0063] In some embodiments, the catalyst layer includes a thermal spraying catalyst layer, such as a Raney nickel catalyst layer, a multi-catalyst layer such as NiAlFe, NiAlMo, etc.; a thermal oxidation catalyst layer, such as a composite catalyst layer of precious metal elements such as Ru, Pt, Pd and rare earth elements such as La, Ce, Pr, Nd, etc.; an electroplating catalyst layer, such as a single or multi-catalyst layer of non-precious metal elements such as Ni, Fe, Cr and precious metal elements such as Ru, Pt, Pd, etc.; an in-situ grown catalyst layer, such as a single or multi-catalyst layer of non-precious metal elements such as Ni, Fe, Cr and precious metal elements such as Ru, Pt, Pd, etc.

[0064] The present application also provides a method for preparing the above-mentioned alkaline water electrolysis hydrogen production electrode, comprising:

[0065] The support layer, the diffusion layer and the catalyst layer are compounded to obtain an alkaline water electrolysis hydrogen production electrode;

[0066] Alternatively, the support layer and the diffusion layer are compounded, and then the catalyst layer is prepared on the diffusion layer to obtain an alkaline water electrolysis hydrogen production electrode.

[0067] Optionally, the compounding includes at least one of pressing, welding, and rolling;

[0068] Optionally, the preparation method includes at least one of thermal spraying, thermal oxidation, electroplating, and in-situ growth.

[0069] The present application also provides an application of the alkaline water electrolysis hydrogen production electrode as described above in water electrolysis hydrogen production.

[0070] The embodiments of the present application will be described in detail below in conjunction with specific examples, but it will be appreciated by those skilled in the art that the following examples are only used to illustrate the present application and should not be considered as limiting the scope of the present application. If specific conditions are not specified in the examples, they are carried out according to normal conditions or the conditions recommended by the manufacturer. If the manufacturer is not specified for the reagents or instruments used, they are all conventional products that can be purchased commercially.

[0071] Example 1

[0072] This embodiment first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 1 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the pore size of the through hole 121 decreases gradually from one side close to the support layer 11 to one side close to the catalyst layer 13. The diffusion layer 12 is pickled, and a 10% hydrochloric acid solution is selected as the pickling liquid, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from four layers of sintered nickel felt, the thickness of the diffusion layer 12 is 1 mm, the thickness of each layer of nickel felt is 0.25 mm, and the porosity from the side close to the support layer 11 to the side close to the catalyst layer 13 is 70%, 60%, 50%, and 40% respectively. The catalyst layer 13 is a Raney nickel catalyst, which is attached to the nickel wire mesh by thermal spraying and then arranged on the diffusion layer 12.

[0073] This embodiment also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of Example 1.

[0074] Example 2

[0075] This embodiment first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 2, including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the pore size of the through hole 121 increases gradually from one side close to the support layer 11 to one side close to the catalyst layer 13. The diffusion layer 12 is pickled, and a 10% hydrochloric acid solution is selected as the pickling liquid, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from four layers of sintered nickel felt, the thickness of the diffusion layer 12 is 1 mm, the thickness of each layer of nickel felt is 0.25 mm, and the porosity from the side close to the support layer 11 to the side close to the catalyst layer 13 is 40%, 50%, 60%, and 70% respectively. The catalyst layer 13 is a Raney nickel catalyst.

[0076] The present embodiment also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the support layer and the diffusion layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the two-layer structure together, and performing hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the two-layer structure, and attaching the Raney nickel catalyst to the diffusion layer 12 by thermal spraying to obtain the alkaline water electrolysis hydrogen production electrode of Example 2.

[0077] Example 3

[0078] This embodiment first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 3 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the pore size of the through hole 121 is constant from one side close to the support layer 11 to one side close to the catalyst layer 13. The diffusion layer 12 is pickled, and the pickling liquid is selected as a 10% hydrochloric acid solution, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from a single-layer nickel felt, the thickness of the diffusion layer 12 is 1 mm, and the porosity of the diffusion layer 12 is 60%. The catalyst layer 13 is a Raney nickel catalyst, which is attached to the nickel wire mesh by thermal spraying and then arranged on the diffusion layer 12.

[0079] This embodiment also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of Example 3.

[0080] Example 4

[0081] This embodiment first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 1 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a nickel punching and drawing mesh with a plate thickness of 0.2 mm and a mesh size of 1.5 mm, a stem width of 1.5 mm, a porosity of 80% for the support layer 11, and a thickness range of 4 mm for the support layer 11. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the aperture of the through hole 121 decreases gradually from one side close to the support layer 11 to one side close to the catalyst layer 13. The diffusion layer 12 is pickled, and a 10% hydrochloric acid solution is selected as the pickling liquid, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from two layers of nickel felt sintered, the thickness of the diffusion layer 12 is 1 mm, and the thickness of each layer of nickel felt is 0.5 mm. The porosity from one side close to the support layer 11 to one side close to the catalyst layer 13 is 70% and 50% respectively. The catalyst layer 13 is a Raney nickel catalyst, which is attached to a nickel wire mesh by a thermal spraying method and then arranged on the diffusion layer 12 .

[0082] This embodiment also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of Example 4.

[0083] Comparative Example 1

[0084] This comparative example first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 1, including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness range of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from the side close to the support layer 11 to the side close to the catalyst layer 13. The through hole 121 is a mesopore, and the pore size of the through hole 121 decreases gradually from the side close to the support layer 11 to the side close to the catalyst layer 13. The diffusion layer 12 is pickled, and a 10% hydrochloric acid solution is selected as the pickling liquid, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from a single layer of nickel wire mesh and two layers of nickel felt sintered, the thickness of the diffusion layer 12 is 1 mm, the nickel wire mesh thickness is 0.5 mm, the nickel felt thickness is 0.25 mm, and the porosity from the side close to the support layer 11 to the side close to the catalyst layer 13 is 90%, 70%, and 60%, respectively. The catalyst layer 13 is a Raney nickel catalyst, which is attached to the nickel wire mesh by thermal spraying and then arranged on the diffusion layer 12.

[0085] This comparative example also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of comparative example 1.

[0086] Comparative Example 2

[0087] This comparative example first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 1 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness range of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the aperture of the through hole 121 decreases gradually from one side close to the support layer 11 to one side close to the catalyst layer 13. The diffusion layer 12 is pickled, and the pickling liquid is selected as a 10% hydrochloric acid solution, and 0.5% polyvinyl alcohol is added as a surfactant to increase the hydrophilic and air-repellent properties of the diffusion layer 12. The material of the diffusion layer 12 is selected from a multi-layer nickel dense mesh, the thickness range of the diffusion layer 12 is 1 mm, and the porosity from one side close to the support layer 11 to one side close to the catalyst layer 13 is 50%, 40%, and 30%, respectively. The catalyst layer 13 is a Raney nickel catalyst, which is attached to a nickel wire mesh by a thermal spraying method and then arranged on the diffusion layer 12 .

[0088] This comparative example also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of comparative example 2.

[0089] Comparative Example 3

[0090] This comparative example first provides an alkaline water electrolysis hydrogen production electrode 10, see Figure 1 , including a support layer 11, a diffusion layer 12 and a catalyst layer 13 stacked in sequence. The support layer 11 is a double-stranded double-layer nickel elastic mesh with a wire diameter of 0.19 mm, the porosity of the support layer 11 is 95%, and the thickness of the support layer 11 is 4 mm. The diffusion layer 12 has a through hole 121 that passes from one side close to the support layer 11 to one side close to the catalyst layer 13. The through hole 121 is a micropore, and the aperture of the through hole 121 decreases gradually from one side close to the support layer 11 to one side close to the catalyst layer 13. The material of the diffusion layer 12 is selected from four layers of nickel felt sintered, the thickness of the diffusion layer 12 is 1 mm, the thickness of each layer of nickel felt is 0.25 mm, and the porosity from one side close to the support layer 11 to one side close to the catalyst layer 13 is 70%, 60%, 50%, and 40%, respectively. The catalyst layer 13 is a Raney nickel catalyst, which is attached to the nickel wire mesh by thermal spraying and then arranged on the diffusion layer 12.

[0091] This comparative example also provides a method for preparing an alkaline water electrolysis hydrogen production electrode, comprising: ① pressing: compacting the three-layer structure into one during the press-fitting and sealing process of the electrolytic cell; ② welding: using resistance welding or spot welding technology to fix the three-layer structure together and perform hemming treatment on the edges; ③ rolling: using a mechanical rolling process to press and seal the edges of the three-layer structure to obtain the alkaline water electrolysis hydrogen production electrode of comparative example 3.

[0092] Performance Testing

[0093] The electrodes of the above embodiments and comparative examples were tested using a standard square electrolytic cell test device. The electrodes of each embodiment and comparative example were assembled into Figure 4 The electrolysis cell shown was tested. Figure 4 20 is the diaphragm, 30 is the bipolar plate, the electrode diameter is 100mm, and the test current density is 4000A / m 2 and 6000A / m 2 , the cell voltage results are shown in Table 1 below.

[0094] Table 1 Cell voltage test results of the electrode structures of various embodiments and comparative examples

[0095] <![CDATA[4000A / m 2 ]]> <![CDATA[6000A / m 2 ]]> Example 1 1.70V 1.83V Example 2 1.75V 1.84V Example 3 1.82V 1.90V Example 4 1.79V 1.88V Comparative Example 1 1.89V 1.99V Comparative Example 2 1.88V 1.97V Comparative Example 3 1.81V 1.91V Traditional electrode structure 1.92V 2.03V

[0096] According to Table 1, it can be seen that the electrode structure of Example 1 is reduced by 200 mV compared with the traditional electrolysis structure, and other embodiments also have obvious advantages; the chamber voltage of the comparative example is relatively higher than that of the embodiment.

[0097] The detachment of bubbles from the electrode surface was observed using a high-speed camera, and the statistics are shown in Table 2 below.

[0098] Table 2 Surface bubble detachment of the electrode structures of various embodiments and comparative examples

[0099] Bubble detachment time Bubble escape size Example 1 3.4s 1.42mm Example 2 5.2s 1.69mm Example 3 8.5s 1.97mm Example 4 3.9s 1.60mm Comparative Example 1 11.1s 2.07mm Comparative Example 2 5.0s 1.49mm Comparative Example 3 9.1s 1.67mm Traditional electrode structure 11.3s 2.16mm

[0100] According to Table 2, it can be seen that Example 1 has certain advantages in both bubble detachment time and bubble detachment size. The porosity of the diffusion layer 12 decreases gradually from the side close to the support layer 11 to the side close to the catalyst layer 13, which has a better effect than a gradient increase. The effect of not having a gradient design is the worst.

[0101] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit it. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application.

[0102] In addition, those skilled in the art will appreciate that, although some embodiments herein include certain features included in other embodiments but not other features, the combination of features of different embodiments is meant to be within the scope of the present application and form different embodiments. For example, in the above claims, any one of the claimed embodiments may be used in any combination. The information disclosed in this background technology section is intended only to deepen the understanding of the overall background technology of the present application and should not be regarded as an admission or in any form of implication that the information constitutes prior art known to those skilled in the art.

Claims

1. An alkaline water electrolysis hydrogen production electrode, characterized in that It comprises a support layer, a diffusion layer and a catalyst layer which are stacked in sequence; the support layer is made of elastic porous material; the diffusion layer has through holes which pass from one side close to the support layer to one side close to the catalyst layer, the through holes are micropores, and the diffusion layer is treated with hydrophilicity and air repellency.

2. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The thickness of the diffusion layer ranges from 0.1 to 3.0 mm, and the porosity of the diffusion layer ranges from 40% to 70%.

3. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The hydrophilic and air-repellent treatment includes chemical treatment or physical treatment; Optionally, the chemical treatment includes any one of pickling treatment and plasma treatment; Optionally, the physical treatment includes any one of sand blasting and laser etching.

4. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The aperture of the through hole is designed to be gradient from a side close to the support layer to a side close to the catalyst layer; Optionally, the pore diameter of the through hole decreases gradually from a side close to the support layer to a side close to the catalyst layer.

5. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The material of the diffusion layer is selected from any one of nickel felt, nickel dense mesh, carbon paper or carbon cloth; Optionally, the material of the diffusion layer is selected from nickel felt; Optionally, the fiber diameter of the nickel felt is less than 0.1 mm, the thickness ranges from 0.1 to 3.0 mm, and the porosity ranges from 40% to 70%.

6. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The porosity of the support layer is 80% to 95%; the thickness of the support layer is in the range of 1 to 5 mm.

7. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The material of the support layer includes any one of foamed nickel, nickel punched and stretched mesh, nickel elastic mesh, nickel-iron alloy punched and stretched mesh or stainless steel punched and stretched mesh.

8. The alkaline water electrolysis hydrogen production electrode according to claim 1, characterized in that: The catalyst layer includes any one of a thermal spraying catalyst layer, a thermal oxidation catalyst layer, an electroplating catalyst layer, and an in-situ growth catalyst layer; Optionally, the thermal sprayed catalyst layer comprises a Raney nickel catalyst layer; Optionally, the Raney nickel catalyst layer includes at least one of NiAlFe and NiAlMo; Optionally, the thermal oxidation catalyst layer includes a composite catalyst layer of noble metal elements and rare earth elements; Optionally, the noble metal element includes at least one of Ru, Pt, and Pd; the rare earth element includes at least one of La, Ce, Pr, and Nd; Optionally, the electroplating catalyst layer and the in-situ growth catalyst layer include a single or multiple catalyst layer of a non-noble metal element and a noble metal element; Optionally, the non-precious metal element includes at least one of Ni, Fe, and Cr, and the precious metal element includes at least one of Ru, Pt, and Pd.

9. A method for preparing an alkaline water electrolysis hydrogen production electrode as claimed in any one of claims 1 to 8, characterized in that: include: Compounding the support layer, the diffusion layer and the catalyst layer to obtain the alkaline water electrolysis hydrogen production electrode; Alternatively, the support layer and the diffusion layer are composited, and then the catalyst layer is prepared on the diffusion layer to obtain the alkaline water electrolysis hydrogen production electrode; Optionally, the compounding includes at least one of pressing, welding, and rolling; Optionally, the preparation method includes at least one of thermal spraying, thermal oxidation, electroplating, and in-situ growth.

10. Use of the alkaline water electrolysis hydrogen production electrode according to any one of claims 1 to 8 in water electrolysis hydrogen production.

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