Hydrogen evolution electrode and preparation method thereof, water electrolysis hydrogen production membrane electrode and electrolytic bath

Abstract

The invention provides a hydrogen evolution electrode and a preparation method thereof, a water electrolysis hydrogen production membrane electrode and an electrolytic bath, and belongs to the technical field of water electrolysis hydrogen production, the hydrogen evolution electrode comprises a substrate layer and a catalyst layer, the substrate layer comprises a first sub-layer, a second sub-layer and a third sub-layer which are arranged in a stacked mode in the first direction, the pore density of the first sub-layer is P1, the porosity is epsilon 1, the pore density of the first sub-layer is P1, the porosity of the second sub-layer is P2, the pore density of the third sub-layer is P3, the porosity of the third sub-layer is P3, P1 < P2 < P3, epsilon 1: epsilon 2: epsilon 3 = (0.9-1.1): (0.9-1.1): (0.9-1.1), the catalyst layer comprises a catalyst, and the catalyst layer is arranged on the surface of the side, provided with the third sub-layer, of the substrate layer. According to the hydrogen evolution electrode provided by the embodiment of the invention, the structural stability can be improved, the short circuit risk and contact resistance caused by piercing can be reduced, the hydrogen evolution reaction performance is ensured, and the service life is prolonged.

Description

TECHNICAL FIELD

[0001] The application relates to the technical field of hydrogen production by water electrolysis, and particularly relates to a hydrogen evolution electrode and a preparation method thereof, a hydrogen production membrane electrode for water electrolysis, and an electrolytic cell. BACKGROUND

[0002] As a new generation of hydrogen production technology by water electrolysis, the AEM (anion exchange membrane) hydrogen production technology has significant advantages in cost, dynamic response and hydrogen production efficiency compared with the traditional alkaline water electrolysis (ALK) hydrogen production technology. In the AEM hydrogen production electrolytic cell, the performance and reliability of the hydrogen evolution electrode are crucial to the stable operation of the entire electrolysis system.

[0003] In the related art, a nickel-based metal mesh or a foam metal material is usually used to load a catalyst in the hydrogen evolution electrode. However, due to the irregular and sharp skeleton structure, low mechanical strength, high surface roughness and other factors of the metal mesh and the foam metal, the anion exchange membrane is easily punctured, thereby causing short circuit or short circuit, and affecting the normal operation of the electrolytic cell. SUMMARY

[0004] Embodiments of the application provide a hydrogen evolution electrode and a preparation method thereof, a hydrogen production membrane electrode for water electrolysis, and an electrolytic cell, which can improve structural stability, reduce the risk of short circuit caused by puncture, ensure hydrogen evolution reaction performance, and prolong service life.

[0005] In a first aspect, embodiments of the application provide a hydrogen evolution electrode, comprising:

[0006] A substrate layer, the substrate layer comprising a first sub-layer, a second sub-layer and a third sub-layer stacked along a first direction, the first sub-layer having a porosity density P1 and a porosity ε1, the second sub-layer having a porosity density P2 and a porosity ε2, the third sub-layer having a porosity density P3 and a porosity ε3, P1 < P2 < P3, and ε1: ε2: ε3 = (0.9-1.1): (0.9-1.1): (0.9-1.1);

[0007] A catalyst layer, the catalyst layer comprising a catalyst, the catalyst layer being arranged on a side surface of the substrate layer having the third sub-layer.

[0008] In some embodiments, the first sub-layer has a grammage G1, the second sub-layer has a grammage G2, and the third sub-layer has a grammage G3, G1 < G2 < G3.

[0009] In some embodiments, the substrate layer has a thickness of 0.3-2.5 mm in the first direction.

[0010] In some embodiments, the thickness ratio of the first sub-layer, the second sub-layer and the third sub-layer is (0.4-0.6):(0.25-0.4):(0.15-0.25).

[0011] In some embodiments, the thickness of the first sub-layer is 1 mm-2 mm;

[0012] and / or, the thickness of the second sub-layer is 0.5 mm-1.5 mm;

[0013] and / or, the thickness of the third sub-layer is 0.5 mm-1.5 mm.

[0014] In some embodiments, the first sub-layer is formed by rolling at least one first foam metal layer;

[0015] and / or, the second sub-layer is formed by rolling at least one second foam metal layer;

[0016] and / or, the third sub-layer is formed by rolling at least one third foam metal layer.

[0017] In some embodiments, the first foam metal layer has a porosity density of 20 ppi-50 ppi, a gram weight of 200 g / m 2 -400 g / m 2 , and a porosity >95%;

[0018] and / or, the second foam metal layer has a porosity density of 50 ppi-80 ppi, a gram weight of 350 g / m 2 ~600 g / m 2 , and a porosity >95%;

[0019] and / or, the third foam metal layer has a porosity density of 80 ppi-150 ppi, a gram weight of 550 g / m 2 -1000 g / m 2 , and a porosity >95%.

[0020] In some embodiments, the first sub-layer has a porosity density of 15 ppi-40 ppi;

[0021] and / or, the second sub-layer has a porosity density of 45 ppi-70 ppi;

[0022] and / or, the third sub-layer has a porosity density of 70 ppi-140 ppi.

[0023] In some embodiments, the catalyst comprises at least one of a transition metal alloy, a metal phosphide, and a metal sulfide.

[0024] In some embodiments, the catalyst has a loading of 0.5 mg / cm 3 -3 mg / cm 3 .

[0025] In a second aspect, the embodiments of the present application provide a preparation method of a hydrogen evolution electrode, comprising:

[0026] providing a first porous material layer, a second porous material layer and a third porous material layer;

[0027] stacking the first porous material layer, the second porous material layer and the third porous material layer along a first direction to obtain a blank;

[0028] rolling the blank, so that the first porous material layer forms a first sub-layer, the second porous material layer forms a second sub-layer, and the third porous material layer forms a third sub-layer to obtain a substrate layer;

[0029] coating a catalytic layer on a side of the substrate layer having the third sub-layer to obtain a hydrogen evolution electrode;

[0030] wherein the first sub-layer has a porosity density P1 and a porosity ε1, the second sub-layer has a porosity density P2 and a porosity ε2, the third sub-layer has a porosity density P3 and a porosity ε3, P1 < P2 < P3, and ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1).

[0031] In some embodiments, the first porous material layer comprises at least one first foam metal layer;

[0032] the second porous material layer comprises at least one second foam metal layer;

[0033] the third porous material layer comprises at least one third foam metal layer.

[0034] In some embodiments, the first porous material layer has a thickness of 1-2 mm in the first direction;

[0035] the second porous material layer has a thickness of 0.5-1.5 mm in the first direction;

[0036] the third porous material layer has a thickness of 0.5-1.5 mm in the first direction.

[0037] In some embodiments, the rolling of the blank comprises:

[0038] pre-rolling the blank at a temperature of 80-120°C and a pressure of 5-10 MPa to obtain a pre-rolled blank;

[0039] first-rolling the pre-rolled blank at a temperature of 200-300°C and a pressure of 10-15 MPa to obtain a first-rolled blank;

[0040] second-rolling the first-rolled blank at a temperature of 200-300°C and a pressure of 20-30 MPa to obtain a second-rolled blank.

[0041] In some embodiments, the rolling speed is set to 0.5 m / min-2 m / min during the first rolling and the second rolling.

[0042] And / or, the roughness of the third sub-layer away from the surface of the second sub-layer is 5 μm-30 μm.

[0043] In some embodiments, after the blank is rolled, the method further comprises:

[0044] The annealing treatment is performed in a mixed atmosphere of hydrogen and argon at a temperature of 500℃-600℃ for 1h-3h.

[0045] In some embodiments, after the substrate layer is obtained, the method further comprises:

[0046] The substrate layer is cleaned to remove the lipid contaminants on the surface of the substrate layer.

[0047] In some embodiments, after the substrate layer is obtained, the method further comprises:

[0048] The substrate layer is soaked in hydrochloric acid or sulfuric acid to dissolve the oxide layer on the surface of the substrate layer.

[0049] In some embodiments, the side of the substrate layer with the third sub-layer is coated with a catalytic layer, comprising:

[0050] The catalytic layer is formed on the side of the substrate layer with the third sub-layer by a dipping method, a chemical vapor deposition method or an electrochemical deposition method.

[0051] In a third aspect, the embodiments of the present application provide a hydrogen production membrane electrode for water electrolysis, comprising the hydrogen evolution electrode as described above, and / or the hydrogen evolution electrode prepared by the preparation method of the hydrogen evolution electrode as described above.

[0052] The hydrogen production membrane electrode for water electrolysis further comprises an anion exchange membrane, which is arranged on the side of the hydrogen evolution electrode with the catalytic layer.

[0053] In a fourth aspect, the embodiments of the present application provide an electrolytic cell, comprising the hydrogen production membrane electrode for water electrolysis as described above.

[0054] The embodiments of the present application have the following beneficial effects:

[0055] In the embodiments of the present application, the hydrogen evolution electrode comprises a substrate layer and a catalytic layer, wherein the substrate layer comprises a first sub-layer, a second sub-layer and a third sub-layer stacked along a first direction, the first sub-layer has a porosity density P1 and a porosity ε1, the second sub-layer has a porosity density P2 and a porosity ε2, the third sub-layer has a porosity density P3 and a porosity ε3, P1 < P2 < P3, and ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1). The catalytic layer comprises a catalyst, and the catalytic layer is arranged on the side surface of the substrate layer with the third sub-layer. By arranging the first sub-layer, the second sub-layer and the third sub-layer with different porosity densities and the porosities ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1), the substrate layer has a gradient porosity density, the first sub-layer has a low porosity density, which can ensure the support strength, improve the transmission performance, reduce the concentration polarization phenomenon, the third sub-layer has a high porosity density, which can improve the protrusion and burr phenomenon, reduce the surface roughness, reduce the phenomenon of piercing the anion exchange membrane, reduce the short circuit risk, improve the operation stability, and the third sub-layer with a high porosity density can help to reduce the contact resistance, improve the loading density of the catalyst in the catalytic layer, and improve the hydrogen evolution reaction performance. The second sub-layer can realize the transition between the first sub-layer and the third sub-layer, and the composite structure of the first sub-layer, the second sub-layer and the third sub-layer can enhance the deformation resistance and is not easy to collapse, thereby prolonging the service life of the hydrogen evolution electrode. That is, the hydrogen evolution electrode provided by the embodiments of the present application can improve the structural stability, reduce the short circuit risk and contact resistance caused by piercing, ensure the hydrogen evolution reaction performance, and prolong the service life. BRIEF DESCRIPTION OF DRAWINGS

[0056] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0057] Figure 1 is a schematic diagram of the longitudinal section structure of the hydrogen evolution electrolysis provided by the embodiments of the present application.

[0058] Explanation of reference signs:

[0059] 10, substrate layer; 11, first sub-layer; 12, second sub-layer; 13, third sub-layer; 20, catalytic layer. DETAILED DESCRIPTION

[0060] The technical solutions in the embodiments of the present application will be clearly and completely described below. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of the present application. In addition, it should be understood that the specific implementation described herein is only used to illustrate and explain the present application, and is not used to limit the present application.

[0061] In a first aspect, as shown in the drawings, the embodiments of the present application provide a hydrogen evolution electrode comprising a substrate layer 10 and a catalyst layer 20, wherein the substrate layer 10 comprises a first sub-layer 11, a second sub-layer 12 and a third sub-layer 13 stacked along a first direction X, the first sub-layer 11 has a porosity density P1, the second sub-layer 12 has a porosity density P2, the third sub-layer 13 has a porosity density P3, P1 Figure 1 The first sub-layer 11, the second sub-layer 12 and the third sub-layer 13 of the substrate layer 10 have different porosity densities and the porosity ratio ε1:ε2:ε3=(0.9-1.1):(0.9-1.1):(0.9-1.1), so that the substrate layer 10 has a gradient porosity density. The first sub-layer 11 has a lower porosity density, which can ensure the support strength, improve the transmission performance, reduce the concentration polarization phenomenon, the third sub-layer 13 has a higher porosity density, which can improve the convex and burr phenomenon, reduce the surface roughness, reduce the phenomenon of piercing the anion exchange membrane, reduce the short circuit risk, improve the operation stability, and the third sub-layer 13 with a higher porosity density can help to reduce the contact resistance, improve the loading density of the catalyst in the catalyst layer 20, and improve the hydrogen evolution reaction performance. The second sub-layer 12 can realize the transition between the first sub-layer 11 and the third sub-layer 13, and the composite structure of the first sub-layer 11, the second sub-layer 12 and the third sub-layer 13 can enhance the anti-deformation ability of the substrate layer 10, which is not easy to collapse, thereby prolonging the service life of the hydrogen evolution electrode. That is, the hydrogen evolution electrode provided by the embodiments of the present application can improve the structural stability, reduce the short circuit risk and contact resistance caused by piercing, ensure the hydrogen evolution reaction performance, and prolong the service life.

[0062] It can be understood that the first direction X in the embodiments of the present application is the thickness direction of the hydrogen evolution electrode. In the case that the porosities of the first sub-layer 11, the second sub-layer 12 and the third sub-layer 13 are close, the higher the porosity density is, the smaller the pore size is, and the higher the density is.

[0063] In some embodiments, the basis weight of the first sublayer 11 is G1, the basis weight of the second sublayer 12 is G2, and the basis weight of the third sublayer 13 is G3, where G1 < G2 < G3. The basis weights of the first sublayer 11, the second sublayer 12, and the third sublayer 13 are set in a gradient manner, which can form a gradient conductive structure and a gradient porous structure, improve the structural stability of the substrate 10, reduce the risk of short circuits and contact resistance caused by puncture, ensure hydrogen evolution reaction performance, and extend service life.

[0064] In some embodiments, the thickness of the substrate 10 in the first direction X is 0.3-2.5 mm. By making the thickness of the substrate 10 in the first direction X 0.3 mm-2.5 mm, sufficient active sites can be provided, electron transport resistance can be reduced, hydrogen evolution reaction efficiency can be improved, and the mechanical strength and structural stability of the substrate 10 can be guaranteed, thereby reducing costs.

[0065] For example, the thickness of the substrate 10 in the first direction X is 0.3 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm or 2.5 mm.

[0066] In some embodiments, the thickness ratio of the first sublayer 11, the second sublayer 12, and the third sublayer 13 is (0.4-0.6):(0.25-0.4):(0.15-0.25). The thicker first sublayer 11 provides good support, ensures the structural stability of the substrate layer 10, reduces interfacial resistance, and promotes rapid electron diffusion. The second sublayer 12, as an intermediate transition layer, has a thickness within the aforementioned range, ensuring ion transport efficiency and reducing migration resistance. The third sublayer 13, in direct contact with the catalyst layer 20 and with a thickness within the aforementioned range, shortens the ion diffusion path and improves transport efficiency.

[0067] In some embodiments, the thickness of the first sublayer 11 is 1mm-2mm. By keeping the thickness of the first sublayer 11 within the above range, a good support effect can be provided, ensuring the structural stability of the base layer 10.

[0068] In some embodiments, the thickness of the second sublayer 12 is 0.5 mm to 1.5 mm. By keeping the thickness of the second sublayer 12 within the above range, ion transport effect can be guaranteed and migration resistance can be reduced.

[0069] In some embodiments, the thickness of the third sublayer 13 is 0.5 mm to 1.5 mm. By keeping the thickness of the third sublayer 13 within the above range, the ion diffusion path can be shortened and the transport efficiency improved.

[0070] In some embodiments, the first sublayer 11 is formed by roll forming at least one first foamed metal layer. The foamed metal (e.g., foamed nickel, foamed copper, or foamed nickel) has high porosity and maintains high connectivity even after roll forming, enabling the formation of a three-dimensional conductive framework. This facilitates rapid electron transport and free diffusion of the liquid. The first foamed metal layer, after roll forming, has a high specific surface area, exposing more active sites and improving the efficiency of the hydrogen evolution reaction. Furthermore, the roll-formed first foamed metal layer exhibits excellent mechanical properties and structural stability.

[0071] In some embodiments, the second sublayer 12 is formed by roll forming at least one second foam metal layer. The second foam metal layer is similar to the first foam metal layer and will not be described again here.

[0072] In some embodiments, the third sublayer 13 is formed by roll forming at least one third foam metal layer. The third foam metal layer is similar to the first foam metal layer and will not be described again here.

[0073] Understandably, the first, second, and third foam metal layers can be made of the same foam metal or different foam metals.

[0074] In some embodiments, the pore density of the first foam metal layer is 20 ppi-50 ppi, and the basis weight is 200 g / m³. 2 -400g / m 2 The porosity is >95%. The pore density, basis weight, and porosity of the first foam metal layer are set within the above range to give it a large pore size, provide a high-strength three-dimensional skeleton, have high mechanical stability, and improve the electrolyte transport efficiency.

[0075] For example, the pore density of the first foam metal layer can be 20ppi, 25ppi, 30ppi, 35ppi, 40ppi, 45ppi or 50ppi, and the basis weight can be 200g / m³. 2 250g / m 2 300g / m 2 350g / m 2 Or 400g / m 2 .

[0076] In some embodiments, the pore density of the second foamed metal layer is 50-80 ppi, and the basis weight is 350 g / m³. 2 ~600g / m 2 The porosity is >95%. The pore density of the second foam metal layer is moderate, ensuring effective interfacial bonding with the first and third foam metal layers, forming a mechanical interlock. The pore size in the second foam metal layer reduces clogging and provides abundant active sites.

[0077] For example, the pore density of the second foam metal layer can be 50 ppi, 55 ppi, 60 ppi, 65 ppi, 70 ppi, 75 ppi or 80 ppi, and the basis weight can be 350 g / m³. 2 400g / m 2 450g / m 2 500g / m 2 550g / m 2 Or 600g / m 2 .

[0078] In some embodiments, the pore density of the third foam metal layer is 80 ppi-150 ppi, and the basis weight is 550 g / m³. 2 -1000g / m 2 The porosity is >95%. The third foam metal layer has a high pore density, which can support more active sites, ensure the catalyst loading, and improve the efficiency of the hydrogen evolution reaction.

[0079] For example, the pore density of the third foam metal layer can be 80ppi, 85ppi, 90ppi, 95ppi, 100ppi, 105ppi, 110ppi, 115ppi, 120ppi, 125ppi, 130ppi, 135ppi, 140ppi, 145ppi, or 150ppi, and the basis weight can be 550g / m³. 2 600g / m 2 650g / m 2 700g / m 2 750g / m 2 800g / m 2 850g / m 2 900g / m 2 950g / m 2 Or 600g / m 2 .

[0080] In some embodiments, the pore density of the first sublayer 11 is 15 ppi-40 ppi. The first foam metal layer is rolled to form the first sublayer 11. By keeping the pore density of the first sublayer 11 within the above range, a high-strength three-dimensional skeleton can be provided, which has high mechanical stability and can improve the transport efficiency of the electrolyte.

[0081] For example, the pore density of the first sublayer 11 can be 15ppi, 20ppi, 25ppi, 30ppi, 35ppi or 40ppi.

[0082] In some embodiments, the pore density of the second sublayer 12 is 45 ppi-70 ppi. The second foam metal layer is formed into the second sublayer 12 after roll forming. By keeping the pore density of the second sublayer 12 within the above range, the interfacial bonding effect with the first foam metal layer and the third foam metal layer can be guaranteed, thus forming a mechanical interlock.

[0083] For example, the pore density of the first sublayer 11 can be 45ppi, 50ppi, 55ppi, 60ppi, 65ppi or 70ppi.

[0084] In some embodiments, the pore density of the third sublayer 13 is 70 ppi-140 ppi. The third foam metal layer is formed by rolling. By keeping the pore density of the third sublayer 13 within the above range, more active sites can be loaded, ensuring the catalyst loading and improving the efficiency of the hydrogen evolution reaction.

[0085] For example, the pore density of the third sublayer 13 can be 70ppi, 75ppi, 80ppi, 85ppi, 90ppi, 95ppi, 100ppi, 105ppi, 110ppi, 115ppi, 120ppi, 125ppi, 130ppi, 135ppi or 140ppi.

[0086] In some embodiments, the first sublayer 11 is formed by roll forming a first foamed metal layer. Forming the first sublayer 11 by roll forming the first foamed metal layer can improve the mechanical properties of the first sublayer 11 and form a three-dimensional skeleton structure with interconnected pores, which helps to improve ion transport efficiency.

[0087] In some embodiments, the second sublayer 12 is formed by roll forming a second foamed metal layer. Forming the second sublayer 12 by roll forming a second foamed metal layer improves the mechanical properties of the second sublayer 12, creates a three-dimensional framework structure with interconnected pores, and helps improve ion transport efficiency.

[0088] In some embodiments, the third sublayer 13 is formed by roll forming a third foamed metal layer. Forming the third sublayer 13 by roll forming a third foamed metal layer improves the mechanical properties of the third sublayer 13, creates a three-dimensional framework structure with interconnected pores, and helps improve ion transport efficiency.

[0089] It is understood that those skilled in the art can adjust the number of the first foam metal layer in the first sub-layer 11, the number of the second foam metal layer in the second sub-layer 12, and the number of the third foam metal layer in the third sub-layer 13 as needed.

[0090] For example, the first sublayer 11 is formed by rolling 1-3 layers of first foam metal layer, the second sublayer 12 is formed by rolling 1-5 layers of second foam metal layer, and the third sublayer 13 is formed by rolling 1-3 layers of third foam metal layer.

[0091] In some embodiments, the catalyst includes at least one of a transition metal alloy, a metal phosphide, and a metal sulfide.

[0092] Among them, the transition metal alloy can be a nickel-molybdenum alloy (Ni-Mo) or an iron-cobalt alloy (Fe-Co), the metal phosphide can be cobalt phosphide (CoP) or nickel phosphide (NiP), and the metal sulfide can be molybdenum disulfide (MoS2) or nickel sulfide (NiS).

[0093] Transition metal alloys, metal phosphides, and metal sulfides are all non-precious metal materials, with low cost and excellent catalytic effects, ensuring the catalytic performance of the hydrogen evolution reaction (HEP). Transition metal alloys, through electronic coupling between different metals, increase the hydrogen adsorption free energy, reduce the HEP overpotential, and guarantee HEP performance. Metal phosphides possess metal-like conductivity, resulting in low electron transport resistance and a high HEP reaction rate. Metal sulfides exhibit high edge activity, leading to high HEP reaction efficiency.

[0094] In some embodiments, the catalyst loading is 0.5 mg / cm³. 3 -3mg / cm 3 By setting the catalyst loading within the above range, sufficient active sites can be provided, catalytic efficiency can be improved, mass transfer and catalysis can be synergistically optimized, the catalytic efficiency of the hydrogen evolution reaction can be guaranteed, and the catalyst cost of the hydrogen evolution electrode can be balanced.

[0095] For example, the catalyst loading can be 0.5 mg / cm³. 3 1.0 mg / cm 3 1.5 mg / cm 3 2.0 mg / cm 3 2.5 mg / cm 3 Or 3mg / cm 3 .

[0096] Secondly, embodiments of this application provide a method for preparing a hydrogen evolution electrode, comprising:

[0097] A first porous material layer, a second porous material layer, and a third porous material layer are provided;

[0098] A first porous material layer, a second porous material layer, and a third porous material layer are stacked along the first direction X to obtain a blank.

[0099] The blank is rolled to form a first sub-layer 11 from the first porous material layer, a second sub-layer 12 from the second porous material layer, and a third sub-layer 13 from the third porous material layer, thus obtaining a base layer 10.

[0100] A catalyst layer 20 is coated on one side of the substrate layer 10 having a third sublayer 13 to obtain a hydrogen evolution electrode;

[0101] The first sublayer 11 has a pore density of P1 and a porosity of ε1, the second sublayer 12 has a pore density of P2 and a porosity of ε2, and the third sublayer 13 has a pore density of P3 and a porosity of ε3, where P1 < P2 < P3 and ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1).

[0102] The method for preparing the hydrogen evolution electrode provided in this application involves rolling a first porous material layer, a second porous material layer, and a third porous material layer stacked together to form a base layer 10. The base layer 10 has a first sub-layer 11, a second sub-layer 12, and a third sub-layer 13 with different pore densities. This method can ensure the deformation resistance of the hydrogen evolution electrode, prevent structural collapse, extend the service life of the hydrogen evolution electrode, reduce the risk of short circuits and contact resistance caused by punctures, ensure the hydrogen evolution reaction performance, and extend the service life.

[0103] In some embodiments, the first porous material layer includes at least one first foamed metal layer. The second porous material layer includes at least one second foamed metal layer. The third porous material layer includes at least one third foamed metal layer.

[0104] Foamed metals (such as nickel foam, copper foam, or nickel foam) have high porosity and maintain a high degree of interconnected pores even after roll forming, enabling the formation of a three-dimensional conductive framework. This facilitates rapid electron transport and free diffusion of the liquid. The first, second, and third foamed metal layers, after roll forming, have a high specific surface area, exposing more active sites and improving the efficiency of the hydrogen evolution reaction. Furthermore, the first, second, and third foamed metal layers treated with roll forming exhibit excellent mechanical properties and structural stability.

[0105] In some embodiments, the thickness of the first porous material layer in the first direction X is 1mm-2mm. The thickness of the second porous material layer in the first direction X is 0.5mm-1.5mm, and the thickness of the third porous material layer in the first direction X is 0.5mm-1.5mm. By setting the thickness of the first porous material layer in the first direction X within the above range, it can be ensured that the pore structure is not over-compressed or damaged during the rolling process, thus forming a stable three-dimensional pore network in the first sub-layer 11 obtained after rolling. Furthermore, by setting the thickness of the first porous material layer in the first direction X to 1mm-2mm, the uniformity during the rolling process can be improved, and the control accuracy of parameters such as pore density and pore size in the first sub-layer 11 can be improved. The thickness control of the second porous material layer and the third plugging material layer is based on similar considerations and will not be elaborated here.

[0106] For example, the thickness of the first porous material layer in the first direction X can be 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm or 2 mm; the thickness of the second porous material layer in the first direction X can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm; and the thickness of the third porous material layer in the first direction X can be 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm or 1.5 mm.

[0107] In some embodiments, rolling the billet includes:

[0108] The billet is pre-rolled at a temperature of 80℃-120℃ and a pressure of 5MPa-10MPa to obtain a pre-rolled billet.

[0109] The pre-rolled billet is rolled once at a temperature of 200℃-300℃ and a pressure of 10MPa-15MPa to obtain a first-rolled billet.

[0110] A secondary roll-pressed billet is obtained by performing a secondary roll-pressing on a primary roll-pressed billet under conditions of 200℃-300℃ and 20MPa-30MPa.

[0111] Pre-rolling the billet at a temperature of 80℃-120℃ and a pressure of 5MPa-10MPa initially fixes the first, second, and third porous material layers within the billet. A primary roll forming at 200℃-300℃ and a pressure of 10MPa-15MPa reduces collapse. A secondary roll forming at 200℃-300℃ and a pressure of 20MPa-30MPa further densifies the billet and improves its mechanical properties.

[0112] In some embodiments, the rolling speed is set to 0.5 m / min-2 m / min during the primary and secondary rolling processes.

[0113] By setting the rolling speed to 0.5m / min-2m / min during the primary and secondary rolling processes, the pressing time of the billet can be guaranteed, the degree of rolling of the billet can be controlled, and the thickness consistency and surface flatness can be guaranteed.

[0114] For example, the rolling speed can be set to 0.5 m / min, 1 m / min, 1.5 m / min or 2 m / min.

[0115] In some embodiments, the surface roughness of the third sublayer 13 facing away from the second sublayer 12 is 5 μm-30 μm. By making the surface roughness of the third sublayer 13 facing away from the second sublayer 12 5 μm-30 μm, it is possible to reduce the impact of surface protrusions and lower the risk of puncturing the anion exchange membrane while ensuring a certain roughness and good contact between the catalyst layer and the third sublayer 13.

[0116] In some embodiments, after rolling the billet, the method further includes:

[0117] Annealing is performed for 1-3 hours at a temperature of 500-600℃ in a mixed atmosphere of hydrogen and argon.

[0118] Annealing can eliminate rolling stress and improve the conductivity of the substrate 10.

[0119] In some embodiments, after obtaining the base layer 10, the method further includes:

[0120] The substrate 10 is cleaned to remove lipid contaminants from its surface. Cleaning removes these contaminants, improving the interfacial bonding between the substrate 10 and the catalyst layer 20, and thus enhancing the stability of the hydrogen evolution electrode.

[0121] For example, the substrate 10 can be cleaned with acetone, ethanol and deionized water to remove lipid contaminants from the surface of the substrate 10.

[0122] In some embodiments, after obtaining the base layer 10, the method further includes:

[0123] The substrate 10 is immersed in hydrochloric acid or sulfuric acid to dissolve the oxide layer on the surface of the substrate 10.

[0124] By dissolving the oxide layer on the surface of the substrate 10, more surface active sites can be provided, thereby improving the efficiency of the hydrogen evolution reaction.

[0125] For example, a 5%-15% hydrochloric acid or sulfuric acid solution can be used for soaking, and the soaking time can be 10 min-30 min.

[0126] In some embodiments, a catalyst layer 20 is coated on the side of the substrate layer 10 having a third sublayer 13, including:

[0127] A catalyst layer 20 is formed on the side of the substrate layer 10 having a third sublayer 13 by means of impregnation, chemical vapor deposition or electrochemical deposition.

[0128] Among these methods, the impregnation method is simple, low-cost, suitable for large-scale production, and can ensure precise control over the thickness of the catalyst layer 20. Chemical vapor deposition (CVD) offers even higher thickness control precision, ensuring the purity of the catalyst layer 20 and improving the interfacial bonding between the catalyst layer 20 and the substrate layer 10. Electrochemical deposition (ECD) can deposit the catalyst layer 20 at room temperature, reducing the impact of high temperatures on the catalyst and allowing for precise control over the morphology of the catalyst layer 20.

[0129] Thirdly, embodiments of this application provide an electrolytic water hydrogen production membrane electrode, including the hydrogen evolution electrode as described above, and / or the hydrogen evolution electrode prepared by the method described above.

[0130] The water electrolysis hydrogen production membrane electrode also includes an anion exchange membrane, which is disposed on the side of the hydrogen evolution electrode with the catalyst layer 20.

[0131] The beneficial effects of the water electrolysis hydrogen production membrane electrode provided in this application embodiment compared to the prior art are basically the same as those of the hydrogen evolution electrode described above, and will not be repeated here.

[0132] Fourthly, this application provides an electrolyzer, including the water electrolysis hydrogen production membrane electrode as described above.

[0133] The electrolyzer provided in this application has the same beneficial effects as the hydrogen evolution electrode described above compared to the prior art, and will not be repeated here.

[0134] The embodiments of this application are further illustrated below with reference to specific examples. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of this application. Experimental methods in the following embodiments that do not specify specific conditions are generally performed according to the conditions recommended by the manufacturer.

[0135] Example 1

[0136] (1) The first porous material layer, the second porous material layer and the third porous material layer are stacked sequentially along the thickness direction to obtain a blank; wherein, the first porous material layer is a layer of foamed nickel with a pore density of 30ppi and a thickness of 2mm, the second porous material layer is a layer of foamed nickel with a pore density of 70ppi and a thickness of 1.5mm, and the third porous material layer is formed by stacking two layers of foamed nickel with a pore density of 120ppi along the thickness direction, and the thickness of each layer of foamed nickel is 0.6mm;

[0137] (2) The billet is pre-rolled at a temperature of 100℃ and a pressure of 8MPa, then rolled once at a temperature of 250℃ and a pressure of 12MPa, and then rolled twice at a temperature of 250℃ and a pressure of 25MPa to obtain a base layer 10 with a thickness of 0.75mm; wherein the rolling speed during the first and second rolling processes is 1m / min, and a first sub-layer 11, a second sub-layer 12 and a third sub-layer 13 are formed in the base layer 10 along the thickness direction;

[0138] (3) Under a mixed atmosphere of hydrogen and argon, the substrate 10 was kept at 550°C for 2 hours, then soaked in 10% hydrochloric acid solution for 20 minutes, and rinsed and dried with deionized water.

[0139] (4) A catalyst layer 20 was prepared on the surface of the substrate layer 10 with a third sublayer 13 by electrochemical deposition. The main salts in the electrolyte were 0.2 mol / L nickel chloride hexahydrate (NiCl2·6H2O) and 0.05 mol / L sodium molybdate dihydrate (Na2MoO4·2H2O), and the complexing agent was 0.3 mol / L trisodium citrate. The pH was adjusted to 8.5±0.2 with ammonia. During the electrochemical deposition process, a pulsed current (duty cycle of 30%, frequency of 50 Hz) was used, with a peak current density of 15 mA / cm². 2 The average current density is 4.5 mA / cm². 2The temperature was set to 45℃±2℃, and deposition was carried out for 30 min (with the electrode orientation rotated every 10 min). The electrode was then washed with deionized water, and surface moisture was purged with nitrogen. After vacuum drying for 2 h, it was reduced and annealed at 300℃ for 1 h under a hydrogen atmosphere to form a catalyst layer 20 containing a Ni-Mo alloy phase and a Ni-Mo alloy, thus obtaining the hydrogen evolution electrode. The molar ratio of the Ni-Mo alloy phase to the Ni-Mo alloy was 3:1, and the catalyst loading was 2.1 mg / cm³. 2 .

[0140] Example 2

[0141] (1) The first porous material layer, the second porous material layer and the third porous material layer are stacked sequentially along the thickness direction to obtain a blank; wherein, the first porous material layer is a layer of foamed nickel with a pore density of 30ppi and a thickness of 2mm, the second porous material layer is a layer of foamed nickel with a pore density of 70ppi and a thickness of 1.5mm, and the third porous material layer is formed by stacking two layers of foamed nickel with a pore density of 150ppi along the thickness direction, and the thickness of each layer of foamed nickel is 0.6mm;

[0142] (2) The billet is pre-rolled at a temperature of 100℃ and a pressure of 8MPa, then rolled once at a temperature of 250℃ and a pressure of 15MPa, and then rolled twice at a temperature of 250℃ and a pressure of 28MPa to obtain a base layer 10 with a thickness of 0.5mm; wherein the rolling speed during the first and second rolling processes is 1m / min, and a first sub-layer 11, a second sub-layer 12 and a third sub-layer 13 are formed in the base layer 10 along the thickness direction;

[0143] (3) Under a mixed atmosphere of hydrogen and argon, the substrate 10 was kept at 550°C for 2 hours, then soaked in 10% hydrochloric acid solution for 20 minutes, and rinsed and dried with deionized water.

[0144] (4) A catalyst layer 20 was prepared on the surface of the substrate layer 10 with a third sublayer 13 by electrochemical deposition: cobalt dicene and triphenylphosphine were used as the cobalt source and phosphorus source, respectively, and high-purity argon gas (flow rate of 50 sccm) was used as the carrier gas. The temperature was set at 600℃ and the deposition time was 20 min to form a catalyst layer 20 containing CoP (cobalt phosphide) nanoparticles; wherein the loading of cobalt phosphide was 1.8 mg / cm³. 2 .

[0145] Example 3

[0146] The main difference between this embodiment and Embodiment 1 is:

[0147] In step (2), the billet is pre-rolled at a temperature of 100℃ and a pressure of 8MPa, then rolled once at a temperature of 250℃ and a pressure of 1.2MPa, and then rolled twice at a temperature of 250℃ and a pressure of 40MPa to obtain a base layer 10 with a thickness of 0.3mm.

[0148] In step (3), the substrate 10 is kept at 700°C for 2 hours in a mixed atmosphere of hydrogen and argon.

[0149] All other conditions remain the same as in Example 1.

[0150] Example 4

[0151] The main difference between this embodiment and Embodiment 1 is:

[0152] In step (1), the first porous material layer is formed by stacking three layers of nickel foam with a pore density of 20 ppi along the thickness direction, with each layer of nickel foam having a thickness of 0.5 mm; the second porous material layer is a layer of nickel foam with a pore density of 50 ppi and a thickness of 0.5 mm; and the third porous material layer is formed by stacking three layers of nickel foam with a pore density of 80 ppi along the thickness direction, with each layer of nickel foam having a thickness of 0.5 mm.

[0153] All other conditions remain the same as in Example 1.

[0154] Example 5

[0155] The main difference between this embodiment and Embodiment 1 is:

[0156] In step (1), the first porous material layer is formed by stacking two layers of nickel foam with a pore density of 50 ppi along the thickness direction, with each layer of nickel foam having a thickness of 1 mm; the second porous material layer is formed by stacking five layers of nickel foam with a pore density of 80 ppi along the thickness direction, with each layer of nickel foam having a thickness of 0.1 mm; and the third porous material layer is a single layer of nickel foam with a pore density of 150 ppi and a thickness of 0.5 mm.

[0157] All other conditions remain the same as in Example 1.

[0158] Example 6

[0159] The main difference between this embodiment and Embodiment 1 is:

[0160] In step (2), the billet is pre-rolled at a temperature of 80°C and a pressure of 5MPa, then rolled once at a temperature of 200°C and a pressure of 10MPa, and then rolled twice at a temperature of 200°C and a pressure of 20MPa to obtain a base layer 10 with a thickness of 0.85mm.

[0161] All other conditions remain the same as in Example 1.

[0162] Example 7

[0163] The main difference between this embodiment and Embodiment 1 is:

[0164] In step (2), the billet is pre-rolled at a temperature of 120°C and a pressure of 10MPa, then rolled once at a temperature of 300°C and a pressure of 15MPa, and then rolled twice at a temperature of 300°C and a pressure of 30MPa to obtain a base layer 10 with a thickness of 0.6mm.

[0165] All other conditions remain the same as in Example 1.

[0166] Comparative Example 1

[0167] The main difference between this comparative example and Comparative Example 1 is:

[0168] In step (1), three layers of nickel foam with a pore density of 70 ppi are stacked, and the thickness of each layer of nickel foam is 2 mm to obtain a blank.

[0169] All other conditions remain the same as in Example 1.

[0170] The surface roughness, ohmic impedance, CP voltage, and leakage of the hydrogen evolution electrode in Examples 1-3 and Comparative Example 1 were tested. Surface roughness was tested according to the method described in Part 13 of "Proton Exchange Membrane Fuel Cells Part 7: Carbon Paper Characteristic Test Methods," and expressed as Ra. Ohmic impedance was tested using an electrochemical workstation at an open-circuit potential, with a frequency of 1–100,000 Hz and an amplitude of 10 mV. The HFR value was recorded to reflect the contact resistance. CP voltage was tested using a single-cell electrolyzer with the hydrogen evolution electrode, 1 M KOH as the electrolyte, at a test temperature of 70°C. The test setup was an electrochemical workstation with a stable test temperature of 60°C. Ten current steps were set to achieve a current density of 0–1 A / cm². 2Each current step test lasts 10 seconds, recording one voltage value per second. The average voltage across each current step is recorded. CP voltage = the sum of voltages across ten current steps / 10. A higher CP voltage indicates poorer mass transfer capability of the water electrolysis cell. The leakage test method is as follows: ① Connect the test system: Connect the electrolyzer to the pressure source (e.g., a nitrogen cylinder) through suitable pipes and valves. Connect either the hydrogen or oxygen path, and seal the other path. Install a high-precision pressure gauge on the connecting pipe; the range should cover the electrolyzer's working pressure range, and the accuracy should be sufficient to detect minute pressure changes, such as ±0.01 MPa. ② Single-sided pressurization: Slowly open the pressure source. ① Initiate gas supply to the hydrogen or oxygen path of the electrolytic cell through the valve. High-purity nitrogen, with a purity of not less than 99.99%, is typically selected. Pressurize to a level slightly higher than the normal operating pressure of the electrolytic cell; for example, if the operating pressure is 1 MPa, pressurize to 1.2 MPa. ② Maintain pressure: After pressurization, close the valve between the pressure source and the electrolytic cell to stabilize the pressure within the cell. The pressure holding time is generally no less than 30 minutes. ③ Observe pressure changes: During the pressure holding period, closely observe the pressure gauge readings and record the initial pressure value and the pressure value at the end of the holding period. If the pressure drop exceeds a certain allowable range, such as a pressure drop exceeding 0.05 MPa per hour, it indicates an airtightness problem. The test results are shown in Table 1.

[0171] Table 1. Comparison of performance test results of hydrogen evolution electrodes in different embodiments and comparative examples.

[0172]

[0173]

[0174] As can be seen from Table 1, the surface roughness of the hydrogen evolution electrode in Examples 1-3 of this application is relatively low, which can significantly reduce the ohmic impedance compared with Comparative Example 1, and no leakage occurs, thereby ensuring the hydrogen evolution reaction performance and extending the service life.

[0175] The comparison between Examples 1-3 shows that the CP voltage of the hydrogen evolution electrode in Examples 1-2 is lower and the mass transfer capability is better than that in Example 3. This is mainly because Examples 1-2 set the pressure range of the rolling process within a certain range, which ensures the pore density in the substrate layer 10 and forms a good three-dimensional pore skeleton. While reducing the ohmic impedance and reducing the risk of leakage caused by puncture, it can also improve the mass transfer performance and improve the efficiency of the hydrogen evolution reaction.

[0176] 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 hydrogen evolution electrode, characterized by, include: The base layer (10) includes a first sub-layer (11), a second sub-layer (12) and a third sub-layer (13) stacked along a first direction; The pore density of the first sublayer (11) is P1, and the porosity is ε1; The second sublayer (12) has a pore density of P2 and a porosity of ε2; The third sublayer (13) has a pore density of P3 and a porosity of ε3. Where P1 < P2 < P3, and ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1); A catalyst layer (20) comprising a catalyst is disposed on the surface of the substrate layer (10) having the third sublayer (13).

2. The hydrogen evolution electrode according to claim 1, wherein The basis weight of the first sublayer (11) is G1, the basis weight of the second sublayer (12) is G2, and the basis weight of the third sublayer (13) is G3, where G1 < G2 < G3.

3. The hydrogen evolution electrode according to claim 1, wherein The thickness of the base layer (10) in the first direction is 0.3mm-2.5mm.

4. The hydrogen evolution electrode according to claim 3, wherein The thickness ratio of the first sublayer (11), the second sublayer (12), and the third sublayer (13) is (0.4-0.6):(0.25-0.4):(0.15-0.25).

5. The hydrogen evolution electrode according to claim 4, wherein The thickness of the first sublayer (11) is 1mm-2mm; And / or, the thickness of the second sublayer (12) is 0.5mm-1.5mm; And / or, the thickness of the third sublayer (13) is 0.5mm-1.5mm.

6. The hydrogen evolution electrode according to claim 1, wherein The first sublayer (11) is formed by rolling at least one first foam metal layer; And / or, the second sublayer (12) is formed by rolling at least one second foam metal layer; And / or, the third sublayer (13) is formed by rolling at least one third foam metal layer.

7. The hydrogen evolution electrode according to claim 6, characterized in that The first foam metal layer has a porosity density of 20-50 ppi, a grammage of 200 g / m 2 - 400 g / m 2 , a porosity > 95% and / or the second foamed metal layer has a porosity density of 50 ppi - 80 ppi, a grammage of 350 g / m 2 ~ 600 g / m 2 a porosity > 95%; and / or the third foam metal layer has a porosity density of 80 ppi - 150 ppi, a grammage of 550 g / m 2 - 1000 g / m 2 with a porosity > 95%.

8. The hydrogen evolution electrode according to claim 7, characterized in that The pore density of the first sublayer (11) is 15ppi-40ppi; And / or, the pore density of the second sublayer (12) is 45 ppi-70 ppi; And / or, the pore density of the third sublayer (13) is 70ppi-140ppi.

9. The hydrogen evolution electrode according to claim 1, wherein The catalyst includes at least one of transition metal alloys, metal phosphides, and metal sulfides.

10. The hydrogen evolution electrode according to any one of claims 1 to 9, characterized in that, The catalyst has a loading of 0.5 mg / cm 3 - 3 mg / cm 3 .

11. A method for producing a hydrogen evolution electrode, characterized by, include: A first porous material layer, a second porous material layer, and a third porous material layer are provided; The first porous material layer, the second porous material layer and the third porous material layer are stacked along the first direction to obtain a blank; The blank is rolled to form a first sub-layer (11) from the first porous material layer, a second sub-layer (12) from the second porous material layer, and a third sub-layer (13) from the third porous material layer, thus obtaining a base layer (10). A catalyst layer (20) is coated on one side of the substrate layer (10) having the third sublayer (13) to obtain a hydrogen evolution electrode; The first sub-layer (11) has a porosity density P1 and a porosity rate ε1, the second sub-layer (12) has a porosity density P2 and a porosity rate ε2, the third sub-layer (13) has a porosity density P3 and a porosity rate ε3, P1 < P2 < P3, and ε1:ε2:ε3 = (0.9-1.1):(0.9-1.1):(0.9-1.1).

12. The method of claim 11, wherein the method further comprises: The first porous material layer comprises at least one first foam metal layer; The second porous material layer comprises at least one second foam metal layer; The third porous material layer comprises at least one third foam metal layer.

13. The method of claim 11, wherein the method further comprises: The thickness of the first porous material layer in the first direction is 1mm-2mm; The thickness of the second porous material layer in the first direction is 0.5mm-1.5mm; The thickness of the third porous material layer in the first direction is 0.5mm-1.5mm.

14. The method of claim 11, wherein the method further comprises: The rolling of the blank comprises: pre-rolling the blank at a temperature of 80℃-120℃ and a pressure of 5MPa-10MPa to obtain a pre-rolled blank; first rolling the pre-rolled blank at a temperature of 200℃-300℃ and a pressure of 10MPa-15MPa to obtain a first-rolled blank; second rolling the first-rolled blank at a temperature of 200℃-300℃ and a pressure of 20MPa-30MPa to obtain a second-rolled blank.

15. The method of claim 14, wherein the method further comprises: During the first rolling and the second rolling, the rolling speed is set to 0.5m / min-2m / min. The roughness of the surface of the third sub-layer (13) on the side away from the second sub-layer (12) is 5μm-30μm.

16. The method of claim 11, wherein the hydrogen evolution electrode is prepared by the steps of: After rolling the blank, further comprising: annealing treatment in a hydrogen and argon mixed atmosphere at a temperature of 500℃-600℃ for 1h-3h.

17. The method of claim 11, wherein the method further comprises: After obtaining the substrate layer (10), further comprising: cleaning the substrate layer (10) to remove lipid contaminants on the surface of the substrate layer (10).

18. The method of claim 11, wherein the method further comprises: After obtaining the substrate layer (10), further comprising: immersing the substrate layer (10) in hydrochloric acid or sulfuric acid to dissolve the oxide layer on the surface of the substrate layer (10).

19. The method of claim 11-18, wherein the method further comprises, The catalytic layer (20) coated on the side of the substrate layer (10) with the third sub-layer (13) comprises: forming the catalytic layer (20) on the side of the substrate layer (10) with the third sub-layer (13) by a dipping method, a chemical vapor deposition method, or an electrochemical deposition method.

20. A hydrogen-producing membrane electrode for electrolysis of water, characterized by The hydrogen evolution electrode comprises the hydrogen evolution electrode according to any one of claims 1-10, and / or the hydrogen evolution electrode prepared by the preparation method according to any one of claims 11-19. The water electrolysis hydrogen production membrane electrode further comprises an anion exchange membrane arranged on the side of the hydrogen evolution electrode with the catalytic layer (20).

21. An electrolytic cell characterized by, The water electrolysis hydrogen production membrane electrode comprises the water electrolysis hydrogen production membrane electrode according to claim 20.

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