Polar plate and method for manufacturing the same, electrolytic cell

Abstract

The application discloses a polar plate, a preparation method thereof and an electrolytic cell. The polar plate comprises a polar plate body and a composite functional layer located on at least one side surface of the polar plate body; the composite functional layer comprises metal layers and ceramic layers which are alternately arranged in a direction away from the polar plate body; the total number of the layers of the metal layers and the layers of the ceramic layers is N, and N satisfies N>=3; the metal layers contain metal elements, and the metal elements comprise one or more of aluminum, copper, chromium, nickel and zinc. The polar plate has good corrosion resistance, which is beneficial to improving the electrolysis life of the electrolytic cell.

Description

Technical Field

[0001] This application relates to the field of water electrolysis technology, specifically to electrode plates and their preparation methods, and electrolytic cells. Background Technology

[0002] An electrolyzer is a device that converts electrical energy into chemical energy. By applying electricity to two electrode plates (anode and cathode), ions in the electrolyte undergo a chemical reaction, producing oxygen at the anode and hydrogen at the cathode. Typically, because the electrode plates operate in a corrosive electrolyte environment—for example, a PEM (proton exchange membrane) electrolyzer usually operates in a strongly acidic environment—the corrosion resistance of the electrode plates needs further improvement to extend the service life of the electrolyzer for stable operation. Summary of the Invention

[0003] The first aspect of this application proposes an electrode plate, including an electrode plate body and a composite functional layer located on at least one surface of the electrode plate body; The composite functional layer includes metal layers and ceramic layers alternately arranged in the direction away from the electrode body; the total number of metal layers and ceramic layers is N, satisfying: N≥3; The metal layer contains metallic elements, including one or more of aluminum, copper, chromium, nickel, and zinc.

[0004] This application forms a multi-layered composite functional layer by alternately setting metal and ceramic layers on the surface of the electrode plate. By utilizing the synergistic effect of the easy corrosion of the metal layer and the corrosion resistance of the ceramic layer, a composite functional layer with anti-corrosion properties that can be automatically recycled is formed, thereby improving the service life of the electrolytic cell while taking into account conductivity and electrolytic performance.

[0005] In some implementations, N satisfies: 100≥N≥3; alternatively, it can be 40≥N≥5.

[0006] In some embodiments, the surface layer of the composite functional layer in the direction away from the electrode body is a ceramic layer.

[0007] In some embodiments, the thickness of the metal layer is 10 nm to 500 nm; and / or, the thickness of the ceramic layer is 10 nm to 100 nm.

[0008] In some embodiments, the ceramic layer contains a MAX phase ceramic material, the chemical formula of which is: M n+1 AX n ; Where n = 1 - 6; M is selected from one or more early transition metal elements; A is selected from one or more elements in Group IIIA and Group IVA; X represents carbon or nitrogen.

[0009] In some embodiments, in the MAX phase ceramic material, M is selected from one or more of Ti, Cr, and Zr, and A is selected from one or more of Al, Si, and Ga.

[0010] The second aspect of this application discloses a method for preparing an electrode plate, comprising: Metal layers and ceramic layers are alternately formed sequentially on at least one side surface of the electrode body and in the direction away from the electrode body. The metal layers and ceramic layers alternately arranged in the direction away from the electrode body serve as a composite functional layer. The total number of metal layers and ceramic layers is N, which satisfies: N≥3. The metal layers contain metal elements, including one or more of aluminum, copper, chromium, nickel, and zinc.

[0011] In some embodiments, the method for forming a metal layer includes one or more of magnetron sputtering and multi-arc ion plating; and / or, the method for forming a ceramic layer includes magnetron sputtering.

[0012] In some implementations, the method satisfies at least one of the following (a) to (d): (a) Forming a metal layer, wherein the control parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 15 W / cm³ 2 -50W / cm 2 ; Deposition time: 1 min - 10 min; (b) Forming a ceramic layer, wherein the controlled parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 1W / cm³ 2 -10W / cm 2 ; Deposition time: 1 min - 10 min; (c) The target material for forming the ceramic layer includes one or more of the MAX phase ceramic materials; (d) The target material for forming the metal layer includes one or more of aluminum, copper, chromium, nickel, and zinc.

[0013] The third aspect of this application proposes an electrolytic cell comprising the electrode plates described in the first aspect above; or comprising the electrode plates prepared by the method described in the second aspect above.

[0014] The electrolytic cell proposed in this application has the aforementioned electrode plates and possesses the beneficial effects of the aforementioned electrode plates, resulting in a longer electrolytic lifespan for the electrolytic cell.

[0015] Additional aspects and advantages of this application will be set forth in part in the description which follows, and in part will be obvious from the description, or may be learned by practice of this application. Attached Figure Description

[0016] The above and / or additional aspects and advantages of the present invention will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which: Figure 1 A schematic diagram of the electrode plate structure in one embodiment of this application is shown.

[0017] Figure 2 The surface resistivity-pressure curve of an embodiment of this application is shown.

[0018] Figure 3 The electrolysis voltage-current density curve of an embodiment of this application is shown.

[0019] Figure 4 The electrolysis life curve of this application is shown.

[0020] Figure label: Electrode body 1; composite functional layer 2; metal layer 21; ceramic layer 22. Detailed Implementation

[0021] The embodiments of this application are described in detail below. The embodiments described below are exemplary and are only used to explain this application, and should not be construed as limiting this application.

[0022] It should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. Furthermore, in the description of this application, unless otherwise stated, "multiple" means two or more.

[0023] The endpoints and any values ​​of the ranges disclosed in this application are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this application.

[0024] In this application, the terms "comprising" or "including" are open-ended expressions, meaning they include the content specified in this application but do not exclude other aspects.

[0025] To address the corrosion problem of electrode plates in electrolytic cells, existing technologies often employ electroplating to prepare an anti-corrosion coating on the electrode plate surface. For example, an anti-corrosion platinum coating is electroplated onto the surface of a pure titanium electrode plate. While platinum coatings offer good conductivity, prevent substrate oxidation, and are relatively stable, their high cost makes them unsuitable for large-scale applications. Therefore, proposing new anti-corrosion functional layers is of great significance for promoting large-scale and industrial applications.

[0026] Therefore, a first aspect of the embodiments of this application proposes an electrode plate, including an electrode plate body and a composite functional layer located on at least one side surface of the electrode plate body; The composite functional layer includes metal layers and ceramic layers alternately arranged in the direction away from the electrode body; the total number of metal layers and ceramic layers is N, satisfying: N≥3; The metal layer contains metallic elements, including one or more of aluminum, copper, chromium, nickel, and zinc.

[0027] Compared to metal layers, ceramic layers offer better corrosion resistance and can serve as a stabilizing layer, providing some short-term corrosion protection. However, as the ceramic layer remains in contact with the electrolyte for an extended period, it will gradually corrode (e.g., through oxidation), leading to a further decrease in its conductivity and corrosion resistance. This, in turn, reduces the overall electrolytic performance of the electrode plate, causing the ceramic layer to fail.

[0028] Compared to ceramic layers, metal layers have better electrical conductivity but are prone to corrosion. They can act as unstable layers, failing to maintain stability in the electrolyte and easily corroding upon contact. This causes the metal layer to gradually peel off, carrying away the weakened or ineffective surface ceramic layer, exposing a new inner ceramic layer that then contacts the electrolyte. This achieves short-term corrosion protection, essentially regenerating the anti-corrosion layer, and the cycle repeats. Considering this effect, the metal layer can also be called a "sacrificial layer," utilizing its susceptibility to corrosion to facilitate the replacement of multiple layers of anti-corrosion coatings.

[0029] In summary, the embodiments of this application form a multi-layered composite functional layer by alternately setting metal and ceramic layers on the surface of the electrode plate. By utilizing the synergistic effect of the easy corrosion of the metal layer and the corrosion resistance of the ceramic layer, a composite functional layer with anti-corrosion function that can be automatically recycled is formed, thereby improving the service life of the electrolytic cell while taking into account conductivity and electrolytic performance.

[0030] In the embodiments of this application, the metal element used in the metal layer can be a metal known in the art that is easily corroded by acid. For example, it can be one or more of aluminum, copper, chromium, nickel, and zinc.

[0031] As an example, the sum of the number of metal layers and the number of ceramic layers is N, which can be 3, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28, 30, 32, 34, 36, 38, 40, 42, 44, 46, 48, 50, 52, 54, 56, 58, 60, 66, 70, 76, 80, 86, 90, 96, 100, etc.

[0032] As an example, such as Figure 1 As shown, metal layer 21 and ceramic layer 22 are alternately arranged on the surface of electrode body 1 in the direction away from electrode body 1, and finally a composite functional layer with 8 layers of metal layer 21 and ceramic layer 22 is formed, which plays the role of blocking electrode body 1 from electrolyte and improving the overall corrosion resistance of electrode.

[0033] In addition, composite functional layers can be provided on both opposite surfaces of the electrode body 1; only one side is shown in the figure.

[0034] In some embodiments of this application, N satisfies: 100≥N≥2; or optionally 40≥N≥5.

[0035] In this embodiment, the multilayer composite functional layer formed by alternating metal and ceramic layers, with the sum of the number of metal layers and the number of ceramic layers being N, satisfies the above conditions, which is beneficial for improving electrolysis life and balancing conductivity and electrolysis performance.

[0036] As an example, an electrolytic lifespan of 1,000 to 100,000 hours of operation can be achieved when the number of layers N is in the range of 2 to 40 layers.

[0037] Furthermore, the total number of metal and ceramic layers, N, is 5-40. This results in better electrolysis life, conductivity, and electrolysis performance.

[0038] In some embodiments of this application, the surface layer of the composite functional layer in the direction away from the electrode body is a ceramic layer. That is, it can be understood that the outermost layer of the composite functional layer is a ceramic layer, which is the first to come into contact with the electrolyte, thus providing some corrosion protection. Furthermore, metal layers and ceramic layers are alternately and sequentially disposed on at least one side surface of the electrode body, where N is an even number.

[0039] The innermost layer of the composite functional layer, that is, the layer in contact with the surface of the electrode body, can be a metal layer or a ceramic layer.

[0040] In some embodiments of this application, the thickness of the metal layer is 10nm-500nm; and / or, the thickness of the ceramic layer is 10nm-100nm.

[0041] In this embodiment, the thickness of the metal layer meets the above conditions, which facilitates better cooperation with the ceramic layer and improves the electrolytic life. As an example, when the ceramic layer attached to its surface fails or is close to failure, the metal layer gradually corrodes, carrying away the ceramic layer attached to its surface, and gradually peels off, thereby exposing the new ceramic layer underneath to achieve anti-corrosion layer regeneration.

[0042] As an example, the thickness of the metal layer is 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, 150nm, 200nm, 250nm, 300nm, 350nm, 400nm, 450nm, 500nm, etc.

[0043] In this embodiment, the thickness of the ceramic layer meets the above conditions, which facilitates better synergy with the ceramic layer, improves electrolytic life, and balances conductivity and electrolytic performance. As an example, a ceramic layer of appropriate dense thickness can be formed to extend the corrosion protection time in each regeneration cycle. As the ceramic layer gradually fails due to corrosion, it can be promptly peeled off along with the metal layer, thus achieving regeneration.

[0044] As an example, the thickness of the ceramic layer is 10nm, 20nm, 30nm, 40nm, 50nm, 60nm, 70nm, 80nm, 90nm, 100nm, etc.

[0045] In some embodiments of this application, the ceramic layer comprises a MAX phase ceramic material, the chemical formula of which is: M n+1 AX n ; Where n = 1 - 6; M is selected from one or more early transition metal elements; A is selected from one or more elements in Group IIIA and Group IVA; X represents carbon or nitrogen.

[0046] In this embodiment, the ceramic layer contains MAX phase ceramic material, which exhibits good corrosion resistance, and also contains metallic elements, which can also have a certain degree of conductivity.

[0047] In some embodiments of this application, in the MAX phase ceramic material, M is selected from one or more of Ti, Cr, and Zr, and A is selected from one or more of Al, Si, and Ga.

[0048] MAX phase ceramic materials are layered ternary carbide or nitride materials. Their crystal structure consists of alternating stacks of metal-carbon / nitrogen layers (MX) and A layers, forming a layered slip system similar to that of metals. However, it can maintain the high hardness and high temperature resistance of ceramics, which is conducive to improving the overall corrosion resistance of the composite functional layer and increasing the electrolytic life.

[0049] A second aspect of this application provides a method for preparing an electrode plate, comprising: Metal layers and ceramic layers are alternately formed sequentially on at least one side surface of the electrode body and in the direction away from the electrode body. The metal layers and ceramic layers alternately arranged in the direction away from the electrode body serve as a composite functional layer. The total number of metal layers and ceramic layers is N, which satisfies: N≥3. The metal layers contain metal elements, including one or more of aluminum, copper, chromium, nickel, and zinc.

[0050] In this embodiment of the application, a multi-layer anti-corrosion layer is prepared, and a structure in which two types of anti-corrosion layers are alternately distributed is formed. For example, a first metal layer is first formed on the surface of the electrode body, and then a first ceramic layer is formed on the surface of the first metal layer away from the electrode body. Then, a second metal layer is formed on the surface of the first ceramic layer away from the first metal layer, and then a second ceramic layer is formed on the surface of the second metal layer away from the first ceramic layer. This process is repeated until a composite functional layer with multiple metal layers and ceramic layers alternately distributed is finally formed.

[0051] The ceramic layer, which initially comes into contact with the external environment (such as the electrolyte), acts as a barrier and prevents corrosion. After a period of operation, the corrosion-preventing effect of the ceramic layer gradually fails, and the inner metal layer is gradually affected by the electrolyte, becoming corroded, disintegrated, and collapsed. This causes the ceramic layer to gradually fall off, exposing a new inner ceramic layer that continues to provide corrosion protection. This process achieves automatic regeneration of the anti-corrosion layer. This cycle repeats continuously, effectively utilizing the excellent performance of the ceramic layer throughout the entire lifespan of the electrolytic cell. It can mitigate the adverse effects of decreased electrolytic performance caused by various problems such as the poor corrosion resistance of the failed ceramic layer and metal leaching poisoning, thereby better improving the electrolytic lifespan while maintaining both conductivity and electrolytic performance.

[0052] In some embodiments of this application, the method for forming a metal layer includes one or more of magnetron sputtering and multi-arc ion plating; and / or, the method for forming a ceramic layer includes magnetron sputtering.

[0053] In this embodiment, a metal layer can be formed by physical vapor deposition, or a ceramic layer can be formed by physical vapor deposition.

[0054] As an example, methods for forming a metal layer include one or more of magnetron sputtering and multi-arc ion plating; methods for forming a ceramic layer include magnetron sputtering.

[0055] In some embodiments of this application, the method satisfies at least one of the following (a) to (d): (a) Forming a metal layer, wherein the control parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 15 W / cm³ 2 -50W / cm 2 ; Deposition time: 1 min - 10 min; (b) Forming a ceramic layer, wherein the controlled parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 1W / cm³ 2 -10W / cm 2 ; Deposition time: 1 min - 10 min; (c) The target material for forming the ceramic layer includes one or more of the MAX phase ceramic materials; (d) The target material for forming the metal layer includes one or more of aluminum, copper, chromium, nickel, and zinc.

[0056] In this embodiment, the deposition temperature for forming the metal layer meets the above conditions, which is beneficial for obtaining a metal layer with stable mechanical properties and better electrical conductivity.

[0057] As an example, the deposition temperatures for forming the metal layer are 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, etc.

[0058] In this embodiment, the deposition time for forming the metal layer meets the above conditions, and the formation of the metal layer of the required thickness can be adjusted and controlled.

[0059] As an example, the deposition time for forming the metal layer is 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.

[0060] In this embodiment, the deposition pressure for forming the metal layer meets the above conditions, which is beneficial for obtaining a dense, stable metal layer with better bonding.

[0061] As an example, the deposition pressure for forming the metal layer is 0.1 Pa, 0.5 Pa, 1.0 Pa, 1.5 Pa, 2.0 Pa, 2.5 Pa, 3.0 Pa, 3.5 Pa, 4.0 Pa, 4.5 Pa, 5.0 Pa, 5.5 Pa, 6.0 Pa, 6.5 Pa, 7.0 Pa, 7.5 Pa, 8.0 Pa, 8.5 Pa, 9.0 Pa, 9.5 Pa, 10.0 Pa, etc.

[0062] In this embodiment of the application, the deposition bias voltage for forming the metal layer satisfies the above conditions, which is conducive to forming a metal layer with better density and stronger adhesion.

[0063] As an example, the deposition bias voltages for forming the metal layer are 300V, 350V, 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, etc.

[0064] In this embodiment, the deposition power density of the metal layer satisfies the above conditions, which is beneficial to improve surface roughness and obtain a metal layer with better adhesion.

[0065] As an example, the deposition power density for forming the metal layer is 15 W / cm². 2 20W / cm 2 25W / cm 2 30W / cm 2 35W / cm 2 40W / cm 2 45W / cm 2 50W / cm 2 wait.

[0066] In this embodiment, the deposition temperature for forming the ceramic layer meets the above conditions, which is conducive to forming a dense and uniform ceramic layer, thereby obtaining better corrosion resistance.

[0067] As an example, the deposition temperatures for forming the ceramic layer are 100℃, 105℃, 110℃, 115℃, 120℃, 125℃, 130℃, 135℃, 140℃, 145℃, 150℃, 155℃, 160℃, etc.

[0068] In this embodiment of the application, the deposition time for forming the ceramic layer meets the above conditions, and the formation of the ceramic layer of the required thickness can be adjusted and controlled.

[0069] As an example, the deposition time for forming the ceramic layer is 1 min, 2 min, 3 min, 4 min, 5 min, 6 min, 7 min, 8 min, 9 min, 10 min, etc.

[0070] In this embodiment, the deposition pressure for forming the ceramic layer meets the above conditions, which is conducive to forming a dense and uniform ceramic layer, obtaining better interfacial bonding force, improving the stability of the ceramic layer, and thus obtaining better corrosion resistance.

[0071] As an example, the deposition pressures for forming the ceramic layer are 0.1 Pa, 0.5 Pa, 1.0 Pa, 1.5 Pa, 2.0 Pa, 2.5 Pa, 3.0 Pa, 3.5 Pa, 4.0 Pa, 4.5 Pa, 5.0 Pa, 5.5 Pa, 6.0 Pa, 6.5 Pa, 7.0 Pa, 7.5 Pa, 8.0 Pa, 8.5 Pa, 9.0 Pa, 9.5 Pa, 10.0 Pa, etc.

[0072] In this embodiment, the deposition bias voltage for forming the ceramic layer satisfies the above conditions, which is conducive to forming a dense and uniform ceramic layer, obtaining good interfacial bonding force, improving the stability of the ceramic layer, and thus obtaining better corrosion resistance.

[0073] As an example, the deposition bias voltages for forming the ceramic layer are 300V, 350V, 400V, 450V, 500V, 550V, 600V, 650V, 700V, 750V, 800V, etc.

[0074] In this embodiment, the deposition power density of the ceramic layer meets the above conditions, which is beneficial to forming a ceramic layer with the required ceramic composition and obtaining a structurally stable corrosion-resistant ceramic layer.

[0075] As an example, the deposition power density for forming the ceramic layer is 1 W / cm². 2 2W / cm 2 3W / cm 2 4W / cm 2 5W / cm 2 6W / cm 2 7W / cm 2 8W / cm 29W / cm 2 10W / cm 2 wait.

[0076] As an example, methods for depositing ceramic layers are provided, including: Prepare ceramic material targets (such as TiAlC targets). Control vacuum level ≤ 5 × 10 -3 After Pa, an inert gas (such as high-purity argon) is introduced, the deposition temperature is controlled at 100℃-600℃, the deposition time is 1min-10min, the deposition pressure is ≥0.1Pa, and the deposition power density is 1W / cm³. 2 -10W / cm 2 The deposition bias voltage is 300V-800V.

[0077] As an example, methods for depositing metal layers are provided, including... Prepare a metal target (such as pure copper). Control vacuum level ≤ 5 × 10 -3 After Pa, an inert gas (such as high-purity argon) is introduced, the deposition temperature is controlled at 100℃-600℃, the deposition time is 1min-10min, the deposition pressure is ≥0.1Pa, and the deposition power density is 15W / cm³. 2 -50W / cm 2 The deposition bias voltage is 300V-800V.

[0078] In some embodiments of this application, the method further includes pre-treating the electrode plate body. Pre-treatment achieves a cleaning effect on the surface of the electrode plate body.

[0079] As an example, preprocessing the basic ontology includes: Pickling, alkali washing, water washing, and ethanol washing are used to remove surface contaminants. Before the formal deposition process, contaminants and oxides on the substrate surface are further removed by glow discharge cleaning and ion source etching.

[0080] A third aspect of this application provides an electrolytic cell comprising the electrode plate described in the first aspect above; or comprising the electrode plate prepared by the method described in the second aspect above.

[0081] The following will explain the solution of this application with reference to embodiments. Those skilled in the art will understand that the following embodiments are for illustrative purposes only and should not be considered as limiting the scope of this application. Where specific techniques or conditions are not specified in the embodiments, they are performed according to the techniques or conditions described in the literature in the art or according to the product instructions. Reagents or instruments whose manufacturers are not specified are all conventional products that can be obtained commercially.

[0082] [Performance Testing] 1. Surface resistivity test: Place 60mm diameter gold-plated copper electrodes on both sides of the sample to be tested, connect a 10A DC power supply, use a 5.5-digit multimeter to measure the voltage between the gold-plated copper electrodes, and apply a pressure of 0-2MPa using a universal testing machine. Calculate the surface resistivity (mΩ • cm) according to the following formula. 2 ).

[0083] R =

[0084] Where A0 represents the area of ​​the gold-plated copper electrode (cm²) 2 I represents the current, and V represents the reading of the precision multimeter when testing the coating sample.

[0085] 2. Electrolysis performance test: Assemble the bipolar plate sample into an electrolytic cell and test at 60℃.

[0086] 3. Electrolysis life test: The electrolytic cell was maintained at an operating temperature of 60℃ for 100 hours. The electrolytic cell consists of bipolar plates and membrane electrodes located between the bipolar plates. Nafion 115 was used as the proton exchange membrane in the membrane electrode, the cathode side catalyst layer used a platinum-carbon catalyst, and the anode side catalyst layer used an iridium black catalyst.

[0087] [Electrode Plate Preparation] Example 1 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 300℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 20W / cm². 2 Deposition time: 3 min; deposition gas pressure: 2 Pa; deposition bias: 300 V; TiAlC magnetron sputtering target: turned on; DC power density: set to 8 W / cm³. 2 Deposition time 5 min, deposition gas pressure 2 Pa, deposition bias 300 V; (4) Repeat step (3) 10 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0088] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 1.488 mΩ·cm. 2 ;like Figure 2As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.909V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA cm⁻¹ in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0089] Example 2 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 500℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper magnetron sputtering target and set the DC power density to 8W / cm³. 2 Deposition time: 5 min; deposition gas pressure: 1 Pa; deposition bias: 500 V; TiAlC magnetron sputtering target: turned on; DC power density: set to 10 W / cm³. 2 Deposition time 4 min, deposition gas pressure 1 Pa, deposition bias 500 V; (4) Repeat step (3) 15 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0090] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 1.136 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.927V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0091] Example 3 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 300℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 20W / cm². 2 Deposition time: 1 min; deposition gas pressure: 0.3 Pa; deposition bias: 600 V; TiAlC magnetron sputtering target: turned on; DC power density: set to 8 W / cm³. 2 The deposition time was 1 min, the deposition gas pressure was 0.3 Pa, and the deposition bias was 600 V. (4) Repeat step (3) 20 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0092] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 0.677 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.92V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0093] Example 4 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing. It was then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment and evacuated to 5×10. -3 Pa, turn on the heating to 300℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 20W / cm². 2 The deposition time was 10 min, the deposition gas pressure was 0.3 Pa, and the deposition bias was 300 V. The TiAlC magnetron sputtering target was turned on, and the DC power density was set to 8 W / cm³. 2 The deposition time was 8 min, the deposition gas pressure was 0.3 Pa, and the deposition bias was 300 V. (4) Repeat step (3) 5 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0094] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 0.65 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.897V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 m·cm⁻¹ in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0095] Example 5 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 100℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 30W / cm². 2 Deposition time 3 min, deposition gas pressure 2 Pa, deposition bias 700 V; TiAlC magnetron sputtering target turned on, DC power density set to 10 W / cm³. 2 Deposition time 5 min, deposition gas pressure 2 Pa, deposition bias 700 V; (4) Repeat step (3) 15 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0096] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 0.162 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.948V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0097] Example 6 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 600℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 20W / cm². 2Deposition time: 2 min; deposition gas pressure: 5 Pa; deposition bias: 800 V; TiAlC magnetron sputtering target: turned on; DC power density: 8 W / cm³. 2 Deposition time 3 min, deposition gas pressure 5 Pa, deposition bias 800 V; (4) Repeat step (3) 15 times to complete the coating; obtain a bipolar plate with a composite functional layer.

[0098] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 1.837 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.958V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 The sample's lifespan remained stable during 100 hours of operation.

[0099] Comparative Example 1 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing, and then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment, and the vacuum was evacuated to 5×10 -3 Pa, turn on the heating to 300℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the copper multi-arc ion plating target and set the arc power density to 20W / cm². 2 The deposition time was 30 min, the deposition gas pressure was 1 Pa, and the deposition bias voltage was 400 V; a bipolar plate with a copper coating was obtained.

[0100] like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 1.102 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolytic cell test at 60℃, the electrolytic performance was 1.923 V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 During 100 hours of operation, the electrolysis voltage gradually increased as the operating time increased. This was because the metal layer (i.e., the copper plating) was continuously corroded, and excessive copper ions contaminated the membrane electrode, leading to a gradual decline in electrolysis performance.

[0101] Comparative Example 2 (1) The bipolar plate substrate (pure titanium) was pretreated by acid washing, alkali washing, water washing, and ethanol washing. It was then installed on the rotating sample holder in the furnace cavity of the vacuum coating equipment and evacuated to 5×10. -3 Pa, turn on the heating to 300℃, and introduce argon gas to a pressure of 0.1 Pa; (2) Set the bias power supply to 800V and continue for 10 minutes to complete the glow discharge cleaning; set the ion source power supply voltage to 700V, duty cycle to 50%, bias to 800V and continue for 10 minutes. (3) Turn on the TiAlC magnetron sputtering target and set the DC power density to 8W / cm³. 2 The deposition time was 45 min, the deposition gas pressure was 1 Pa, and the deposition bias voltage was 400 V; a bipolar plate with a ceramic coating was obtained. like Figure 1 As shown, at 2 MPa, the surface resistance of the bipolar plate is 0.622 mΩ·cm. 2 ;like Figure 2 As shown, in the PEM electrolyzer test at 60℃, the electrolytic performance was 1.918 V @ 2000 mA·cm⁻¹. -2 ;like Figure 3 As shown, the current density was tested at 2000 mA·cm² in a PEM electrolytic cell at 60℃. -2 During the 100-hour operation, the electrolysis voltage gradually increased as the operating time increased. This was because the ceramic layer (i.e., the TiAlC coating) gradually oxidized, leading to a gradual decline in electrolysis performance.

[0102] In summary, the electrode plates with composite functional layers provided in Embodiments 1-6 of this application can effectively improve the service life of electrolytic cells. For example... Figure 4 As shown, in the electrolysis life test, compared with Comparative Examples 1 and 2, the embodiment of this application showed that the electrolysis voltage remained relatively stable as the running time increased, demonstrating a good service life; while in Comparative Examples 1 and 2, the electrolysis voltage gradually increased and the electrolysis performance gradually declined as the running time increased. Furthermore, the electrode plates with composite functional layers provided in Embodiments 1-6 of this application, when applied in the electrolytic cell, can maintain relatively high surface resistivity and electrolysis performance. This achieves the goal of improving the service life of the electrolytic cell while also considering conductivity and electrolysis performance.

[0103] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. An electrode plate, characterized in that, It includes an electrode body and a composite functional layer located on at least one surface of the electrode body; The composite functional layer includes metal layers and ceramic layers alternately arranged in a direction away from the electrode body; the total number of metal layers and ceramic layers is N, satisfying: N≥3; The metal layer contains a metal element, which includes one or more of aluminum, copper, chromium, nickel, and zinc.

2. The electrode plate according to claim 1, characterized in that, The N satisfies: 100≥N≥3; or can be 15≥N≥5.

3. The electrode plate according to claim 1 or 2, characterized in that, The surface layer of the composite functional layer in the direction away from the electrode body is the ceramic layer.

4. The electrode plate according to claim 1 or 2, characterized in that, The thickness of the metal layer is 10 nm-500 nm; and / or, The thickness of the ceramic layer is 10nm-100nm.

5. The electrode plate according to claim 1 or 2, characterized in that, The ceramic layer contains a MAX phase ceramic material, the chemical formula of which is: M n+1 AX n ; Where n = 1 - 6; M is selected from one or more early transition metal elements; A is selected from one or more elements in Group IIIA and Group IVA; X represents carbon or nitrogen.

6. The electrode plate according to claim 5, characterized in that, In the MAX phase ceramic material, M is selected from one or more of Ti, Cr, and Zr, and A is selected from one or more of Al, Si, and Ga.

7. A method for preparing an electrode plate, characterized in that, include: Metal layers and ceramic layers are sequentially and alternately formed on at least one side surface of the electrode body in a direction away from the electrode body. The metal layers and ceramic layers arranged alternately in a direction away from the electrode body serve as a composite functional layer. The sum of the number of metal layers and the number of ceramic layers is N, which satisfies: N≥3. The metal layers contain metal elements, including one or more of aluminum, copper, chromium, nickel, and zinc.

8. The method according to claim 7, characterized in that, The method for forming the metal layer includes one or more of magnetron sputtering and multi-arc ion plating; and / or, the method for forming the ceramic layer includes magnetron sputtering.

9. The method according to claim 8, characterized in that, Satisfy at least one of the following (a) to (d): (a) Forming the metal layer, wherein the control parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 15 W / cm³ 2 -50W / cm 2 ; Deposition time: 1 min - 10 min; (b) Forming the ceramic layer, wherein the control parameters include at least one of the following: The deposition temperature is 100℃-600℃; Deposition gas pressure: 0.1 Pa - 10 Pa; Deposition bias voltage: 300V-800V; Deposition power density: 1W / cm³ 2 -10W / cm 2 ; Deposition time: 1 min - 10 min; (c) The target material for forming the ceramic layer includes one or more of MAX phase ceramic materials; (d) The target material for forming the metal layer includes one or more of aluminum, copper, chromium, nickel, and zinc.

10. An electrolytic cell, characterized in that, It includes the electrode plate according to any one of claims 1 to 6; or, it includes the electrode plate prepared by the method according to any one of claims 7 to 9.

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