A multi-element composite coating anode plate and a preparation method thereof

Abstract

The application relates to a kind of multicomponent composite coating anode plate and its preparation method, belong to anode technical field.The anode plate includes metal matrix and composite coating sequentially arranged on the surface of the metal matrix, the composite coating is sequentially bottom layer, intermediate layer and surface layer from bottom to top;The bottom layer is MAX phase conductive layer, combined with metal matrix by vacuum plasma spraying, the intermediate layer is formed in situ by using MAX phase in the bottom layer as template, the surface layer is prepared by fluorine-doped SnO2 treated by titanate, chloroiridic acid and pentachloride, and the MAX phase is at least one of Ti3AlC2 and Ti2AlC.The anode prepared by the application has excellent bonding force, chemical activity and strengthening life.

Description

Technical Field

[0001] This invention belongs to the field of anode technology and relates to a multi-component composite coated anode plate and its preparation method. Background Technology

[0002] In the copper foil production process, the electrolysis process is the core link that determines the quality of copper foil, and the anode, as a key component of the electrolysis system, has its performance directly related to electrolysis efficiency, energy consumption and product quality.

[0003] Currently, size-stability anodes are widely used in industry for copper foil electrolysis. These anodes typically use titanium or titanium alloys as the substrate, with a surface coated with noble metal oxides or their composite oxides as the electrocatalytic active layer. However, they suffer from the following problems during long-term use: (i) Insufficient bonding strength between the coating and the substrate, making it prone to peeling and failure; (ii) Increased interfacial resistance, leading to increased electrolysis energy consumption; (iii) Limited coating life; (iv) High amount of precious metals, resulting in high cost pressure.

[0004] Therefore, there is an urgent need to develop an anode that combines high bonding strength, low oxygen evolution overpotential, and long service life. Summary of the Invention

[0005] The purpose of this invention is to provide a multi-component composite coated anode plate and its preparation method. The prepared anode coating has excellent adhesion, electrochemical activity and enhanced lifespan.

[0006] The objective of this invention can be achieved through the following technical solutions: A multi-component composite coating anode plate, the anode plate comprising a metal substrate and a composite coating sequentially disposed on the surface of the metal substrate, the composite coating being, from bottom to top, a bottom layer, an intermediate layer and a top layer; The bottom layer is a MAX phase conductive layer, which is bonded to the metal substrate by vacuum plasma spraying. The middle layer is formed in situ using the MAX phase in the bottom layer as a template. The surface layer is prepared by treating with titanate esters and using fluorine-doped SnO2, chloroiridic acid and tantalum pentachloride. The MAX phase is at least one of Ti3AlC2 and Ti2AlC.

[0007] A method for preparing a multi-component composite coated anode plate includes the following steps: S1. Matrix pretreatment: After sandblasting, the titanium substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes, then immersed in acid etching solution at 25-30℃ for 2-3 minutes, and then rinsed with deionized water and dried. S2, Bottom Layer Preparation: Ti3AlC2 powder is sprayed onto the surface of a pretreated substrate by vacuum plasma spraying to form an underlayer. S3, Intermediate Layer Preparation: The titanium substrate obtained in step S2 is placed in an atmosphere tube furnace. First, high-purity argon gas is introduced for 15 minutes at a flow rate of 2 L / min. Then, a mixture of Ar / O2 gas is introduced, in which oxygen accounts for 0.5~2.0% of the volume fraction of the mixture gas at a flow rate of 2 L / min. After heat treatment, an intermediate layer is obtained. S4. Surface preparation: Fluorine-doped SnO2 was pretreated with a titanate coupling agent, and then chloroiridic acid, tantalum pentachloride, pretreated fluorine-doped SnO2 and solvent were mixed and stirred for 30 min to obtain a dispersion coating solution. The dispersion coating solution was coated on the surface of the intermediate layer after step S3 to obtain a multi-element composite coating anode plate with a surface thickness of 2~3 μm.

[0008] As a preferred technical solution of the present invention, in step S1, the acid etching solution is hydrofluoric acid, nitric acid and deionized water in a volume ratio of (0.5~0.8):(1.5~2.0):(5~7).

[0009] As a preferred technical solution of the present invention, in step S2, during the vacuum plasma spraying process, the working current is 450~500A, the working voltage is 60~70V, the argon pressure is 0.7~0.8MPa, the powder feeding rate is 10~15g / min, and the spraying distance is 150~200mm.

[0010] As a preferred technical solution of the present invention, in step S2, the thickness of the bottom layer is 5~10μm.

[0011] As a preferred technical solution of the present invention, in step S3, the heat treatment conditions are as follows: heating to 590~610℃ at a rate of 5℃ / min, holding at that temperature for 60~80min, and cooling to room temperature with the furnace, while maintaining a low oxygen partial pressure atmosphere.

[0012] As a preferred embodiment of the present invention, in step S3, the thickness of the intermediate layer is 2~5μm.

[0013] As a preferred embodiment of the present invention, in step S4, the weight ratio of chloroiridic acid, tantalum pentachloride, pretreated fluorine-doped SnO2 and solvent is (2~6):(1~3):(0.3~0.6):(30~40).

[0014] As a preferred embodiment of the present invention, in step S4, the solvent is n-butanol and isopropanol in a volume ratio of 1:1.

[0015] As a preferred embodiment of the present invention, step S4 further includes: the coating amount each time is 0.5~0.8 mL / cm. 2After each coating, the sample is dried under an infrared lamp for 5 minutes, then transferred to a muffle furnace for thermal decomposition and sintering at 500°C for 10-15 minutes. The coating, drying, and sintering process is repeated 8-12 times. Finally, the sample is held at 500°C for 60 minutes for final heat treatment and then cooled to room temperature in the furnace.

[0016] This invention pre-treats the titanium matrix to remove impurities and oxide films, while simultaneously improving the surface activity of the titanium matrix, thereby enhancing the bonding force between the subsequent MAX phase and the titanium matrix.

[0017] By introducing MAX phase ceramic material as the surface layer, and utilizing its unique layered structure, it can provide excellent conductivity and form a stronger bond with the metal substrate. In this invention, a MAX phase underlayer is deposited on the surface of a titanium substrate by vacuum plasma spraying. During the spraying process, the MAX phase and the titanium substrate undergo atomic diffusion to form an interface with high bonding strength.

[0018] Meanwhile, step S3 controls oxygen partial pressure, temperature, and time, taking advantage of the thermodynamic advantage that Al has a higher affinity for O than Ti has for O, so that Al atoms in the MAX phase preferentially diffuse outward and are oxidized, and the MX layer (Ti3C2) framework is preserved. Therefore, through the controllable selective oxidation of the bottom MAX phase, a gradient transition layer with continuously changing composition and structure is constructed in situ, thereby eliminating the interfacial stress caused by the difference in thermal expansion coefficient and improving the coating adhesion.

[0019] This invention introduces fluorine-doped SnO2 as a conductive reinforcing phase into the surface layer. FTO (fluorine-doped SnO2) is pretreated with a titanate coupling agent. The inorganic-philic end of the coupling agent bonds to the hydroxyl groups on the FTO surface, while the organic-philic end is compatible with the noble metal precursor, achieving uniform dispersion of FTO in the coating. Furthermore, during sintering, the coupling agent undergoes pyrolysis to generate a TiO2 nanolayer, further enhancing the coating's strength. The oxygen vacancies in the fluorine-doped SnO2 and the active sites in the IrO2 exhibit a synergistic catalytic effect, effectively reducing the activation energy of the oxygen evolution reaction.

[0020] The beneficial effects of this invention are: This invention features a three-layer structure with complementary functions, achieving a synergistic improvement in activity, bonding strength, and lifespan. The bottom layer provides high conductivity and bonding, the middle layer buffers thermal stress, and the surface layer introduces fluorine-doped SnO2 as a conductivity-enhancing phase, with an addition amount of 10-20 mol% of the total precious metal content. This provides a synergistic catalytic effect, reduces the amount of chloroiridium acid used, and lowers the precious metal cost of the coating material. The anode prepared by this invention exhibits excellent bonding strength, chemical activity, and enhanced lifespan. Detailed Implementation

[0021] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with embodiments, is provided below.

[0022] It should be noted that, unless otherwise specified, the present invention does not specifically limit the source of the raw materials used in the following embodiments. Commercially available products or products prepared by conventional preparation methods that are well known to those skilled in the art can be used. Experimental methods that do not specify specific conditions are all conventional methods and conventional conditions well known in the art.

[0023] The pretreatment process for fluorine-doped SnO2 includes: Fluorine-doped SnO2 nanoparticles (fluorine doping amount 8at%, particle size 15~25nm) were mixed with isopropyltris(dioctylpyrophosphoryloxy)titanate coupling agent at a weight ratio of 100:3, added to anhydrous ethanol, with a solid-liquid ratio of 1:8, ultrasonically dispersed for 30 min, transferred to an 80℃ water bath and stirred for 2 h. After the process, the mixture was filtered, washed three times with anhydrous ethanol, vacuum dried at 80℃ for 12 h, and ground through a 200-mesh sieve to obtain pretreated fluorine-doped SnO2. Example 1

[0024] S1. Matrix pretreatment: TA1 industrial pure titanium plate was selected as the substrate material. 46-mesh white corundum sand was used to sandblast the surface of the titanium substrate to achieve a roughness Ra of 3~5μm. The sandblasted titanium substrate was then ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes, followed by immersion in an acid etching solution at 28℃ for 3 minutes. The acid etching solution consisted of 40% hydrofluoric acid, 68% nitric acid, and deionized water in a volume ratio of 0.6:1.6:6. The substrate was then rinsed with deionized water and dried. S2, Substrate Preparation: Ti3AlC2 powder was sprayed onto the surface of a pretreated substrate to form a base layer by vacuum plasma spraying. During the vacuum plasma spraying process, the working current was 480A, the working voltage was 65V, the argon pressure was 0.75MPa, the powder feeding rate was 12g / min, the spraying distance was 180mm, and the base layer thickness was 6μm. S3, Intermediate Layer Preparation: The titanium substrate obtained in step S2 was placed in an atmosphere tube furnace. First, high-purity argon gas was introduced for 15 minutes at a flow rate of 2 L / min. Then, an Ar / O2 mixture was introduced, in which oxygen accounted for 1.0% of the volume of the mixture at a flow rate of 2 L / min. After heat treatment, an intermediate layer was obtained. The temperature was increased to 600℃ at a rate of 5℃ / min and held for 70 minutes. The mixture was then cooled to room temperature with the furnace, maintaining a low oxygen partial pressure atmosphere during the process. The thickness of the intermediate layer obtained was 3 μm. S4. Surface preparation: Fluorine-doped SnO2 was pretreated with a titanate coupling agent. Then, chloroiridic acid, tantalum pentachloride, the pretreated fluorine-doped SnO2, and a solvent were mixed in a weight ratio of 4:2:0.5:35. The solvent was a 1:1 volume ratio of n-butanol and isopropanol. After stirring for 30 minutes, a dispersion coating was obtained. This dispersion coating was then applied to the surface of the intermediate layer obtained in step S3, with each application amount being 0.5–0.8 mL / cm². 2 After each coating, the sample was dried under an infrared lamp for 5 minutes, then transferred to a muffle furnace for thermal decomposition and sintering at 500℃ for 12 minutes. The above coating, drying, and sintering process was repeated 10 times. Finally, the sample was held at 500℃ for 60 minutes for final heat treatment and then cooled to room temperature with the furnace to obtain a multi-element composite coating anode plate with a surface thickness of 2μm. Example 2

[0025] S1. Matrix pretreatment: TA1 industrial pure titanium plate was selected as the substrate material. 46-mesh white corundum sand was used to sandblast the surface of the titanium substrate to achieve a roughness Ra of 3~5μm. The sandblasted titanium substrate was then ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes, followed by immersion in an acid etching solution at 25℃ for 2 minutes. The acid etching solution consisted of 40% hydrofluoric acid, 68% nitric acid, and deionized water in a volume ratio of 0.5:1.5:5. The substrate was then rinsed with deionized water and dried. S2, Substrate Preparation: Ti3AlC2 powder was sprayed onto the surface of a pretreated substrate to form a base layer by vacuum plasma spraying. During the vacuum plasma spraying process, the working current was 450A, the working voltage was 60V, the argon pressure was 0.7MPa, the powder feeding rate was 10g / min, the spraying distance was 150mm, and the base layer thickness was 5μm. S3, Intermediate Layer Preparation: The titanium substrate obtained in step S2 was placed in an atmosphere tube furnace. First, high-purity argon gas was introduced for 15 minutes at a flow rate of 2 L / min. Then, an Ar / O2 mixed gas was introduced, in which oxygen accounted for 0.5% of the volume of the mixed gas at a flow rate of 2 L / min. After heat treatment, an intermediate layer was obtained. The temperature was increased to 590°C at a rate of 5°C / min and held for 60 minutes. The intermediate layer was then cooled to room temperature with the furnace, maintaining a low oxygen partial pressure atmosphere during the process. The thickness of the intermediate layer obtained was 2 μm. S4. Surface preparation: Fluorine-doped SnO2 was pretreated with a titanate coupling agent. Then, chloroiridic acid, tantalum pentachloride, the pretreated fluorine-doped SnO2, and a solvent were mixed in a weight ratio of 2:1:0.3:30. The solvent was a 1:1 volume ratio of n-butanol and isopropanol. After stirring for 30 minutes, a dispersion coating was obtained. This dispersion coating was then applied to the surface of the intermediate layer obtained in step S3, with a coating amount of 0.5 mL / cm² each time. 2 After each coating, the sample is dried under an infrared lamp for 5 minutes, then transferred to a muffle furnace for thermal decomposition and sintering at 500℃ for 10 minutes. The above coating, drying, and sintering process is repeated 10 times. Finally, the sample is held at 500℃ for 60 minutes for final heat treatment and then cooled to room temperature in the furnace to obtain a multi-element composite coating anode plate with a surface thickness of 2μm. Example 3

[0026] S1. Matrix pretreatment: TA1 industrial pure titanium plate was selected as the substrate material. 46-mesh white corundum sand was used to sandblast the surface of the titanium substrate to achieve a roughness Ra of 3~5μm. The sandblasted titanium substrate was then ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes, followed by immersion in an acid etching solution at 30℃ for 3 minutes. The acid etching solution consisted of 40% hydrofluoric acid, 68% nitric acid, and deionized water in a volume ratio of 0.8:2.0:5. The substrate was then rinsed with deionized water and dried. S2, Substrate Preparation: Ti3AlC2 powder was sprayed onto the surface of a pretreated substrate to form a base layer by vacuum plasma spraying. During the vacuum plasma spraying process, the working current was 500A, the working voltage was 70V, the argon pressure was 0.8MPa, the powder feeding rate was 15g / min, the spraying distance was 200mm, and the base layer thickness was 10μm. S3, Intermediate Layer Preparation: The titanium substrate obtained in step S2 was placed in an atmosphere tube furnace. First, high-purity argon gas was introduced for 15 minutes at a flow rate of 2 L / min. Then, an Ar / O2 mixed gas was introduced, in which oxygen accounted for 2.0% of the volume of the mixed gas at a flow rate of 2 L / min. After heat treatment, an intermediate layer was obtained. The temperature was increased to 610℃ at a rate of 5℃ / min and held for 80 minutes. The intermediate layer was then cooled to room temperature with the furnace, maintaining a low oxygen partial pressure atmosphere during the process. The thickness of the intermediate layer obtained was 5 μm. S4. Surface preparation: Fluorine-doped SnO2 was pretreated with a titanate coupling agent. Then, chloroiridic acid, tantalum pentachloride, the pretreated fluorine-doped SnO2, and a solvent were mixed in a weight ratio of 6:3:0.6:40. The solvent was a 1:1 volume ratio of n-butanol and isopropanol. After stirring for 30 minutes, a dispersion coating was obtained. This dispersion coating was then applied to the surface of the intermediate layer obtained in step S3, with a coating amount of 0.8 mL / cm² each time.2 After each coating, the sample was dried under an infrared lamp for 5 minutes, then transferred to a muffle furnace for thermal decomposition and sintering at 500°C for 15 minutes. The coating, drying, and sintering process was repeated 10 times. Finally, the sample was held at 500°C for 60 minutes for final heat treatment and then cooled to room temperature in the furnace to obtain a multi-element composite coating anode plate with a surface thickness of 3 μm. Example 4

[0027] It is basically the same as Example 1, except that Ti2AlC powder (particle size 20~50μm) is used instead of Ti3AlC2.

[0028] Comparative Example 1 This is basically the same as Example 1, except that the fluorine-doped SnO2 in step S4 of this comparative example was not pretreated with a titanate coupling agent.

[0029] Comparative Example 2 This comparative example is basically the same as Example 1, except that the surface coating solution in step S4 does not contain fluorine-doped SnO2, but only uses chloroiridic acid, tantalum pentachloride and solvent in a ratio of 4:2:35. The rest of the steps are exactly the same.

[0030] Comparative Example 3 This is basically the same as Example 1, except that this comparative example did not go through step S1.

[0031] Comparative Example 4 This is basically the same as Example 1, except that this comparative example does not go through step S2, and the S3 intermediate layer is prepared directly on the pretreated titanium substrate.

[0032] Comparative Example 5 This is basically the same as Example 1, except that this comparative example does not go through steps S2 and S3, and the surface layer is prepared directly on the pretreated titanium substrate.

[0033] Performance testing: 1. Coating adhesion: Using the cross-cutting method, a grid is cut on the coating surface with a grid cutter. The blade spacing is 1mm, and the cutting depth penetrates the coating to the substrate. After cutting, the chips are gently swept away with a soft brush. 3M 600 tape is applied to the grid area and pressed flat with an eraser to ensure full contact. Holding the free end of the tape at a 60° angle to the coating surface, it is peeled off smoothly within 0.5~10s. The coating peeling in the grid area is observed under a magnifying glass and rated. 2. Oxygen evolution overpotential: A three-electrode system was adopted, with the working electrode being the anode to be tested (1 cm). 2The counter electrode was a platinum sheet, the reference electrode was a saturated calomel electrode, the electrolyte was a 1.0 mol / L H₂SO₄ solution, the temperature was 25℃, the scan rate was 5 mV / s, and the recording current density was 10 mA / cm². 2 The potential at time (vs. SCE) is converted to the oxygen evolution overpotential; 3. Enhanced lifespan: At 40℃, 1.5M H2SO4, 2A / cm 2 Under accelerated aging conditions, continuous electrolysis was performed, and the time when the electrode potential suddenly rose to 5V (considered as anodic failure) was recorded. The failure time was also recorded. The test results are shown in the table below: Based on the above data, it can be seen that the anode coating prepared by the present invention, by introducing a MAX phase transition layer and a fluorine-doped SnO2 conductive enhancement phase, is superior to the comparative example in terms of bonding strength, oxygen evolution overpotential, and enhanced lifetime. The anode coating prepared by the present invention has excellent bonding strength, electrochemical activity, and enhanced lifetime.

[0034] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention shall still fall within the scope of the present invention.

Claims

1. A multi-component composite coated anode plate, characterized in that, The anode plate includes a metal substrate and a composite coating sequentially disposed on the surface of the metal substrate, wherein the composite coating consists of a bottom layer, an intermediate layer and a top layer from bottom to top; The bottom layer is a MAX phase bonded to the metal substrate by vacuum plasma spraying. The middle layer is formed in situ by using the MAX phase in the bottom layer as a template. The surface layer is prepared by treating with titanate ester, fluorine-doped SnO2, chloroiridic acid and tantalum pentachloride. The MAX phase is at least one of Ti3AlC2 and Ti2AlC.

2. A method for preparing a multi-element composite coated anode plate as described in claim 1, characterized in that, The process includes the following: S1. Matrix pretreatment: After sandblasting, the titanium substrate was ultrasonically cleaned in acetone and anhydrous ethanol for 15 minutes, then immersed in acid etching solution at 25-30℃ for 2-3 minutes, rinsed with deionized water and dried. S2, Bottom Layer Preparation: Ti3AlC2 powder is sprayed onto the surface of a pretreated substrate by vacuum plasma spraying to form an underlayer. S3, Intermediate Layer Preparation: The titanium substrate obtained in step S2 is placed in an atmosphere tube furnace. First, high-purity argon gas is introduced for 15 minutes at a flow rate of 2 L / min. Then, a mixture of Ar / O2 gas is introduced, in which oxygen accounts for 0.5~2.0% of the volume fraction of the mixture gas at a flow rate of 2 L / min. After heat treatment, an intermediate layer is obtained. S4. Surface preparation: Fluorine-doped SnO2 was pretreated with a titanate coupling agent, and then chloroiridic acid, tantalum pentachloride, pretreated fluorine-doped SnO2 and solvent were mixed and stirred for 30 min to obtain a dispersion coating solution. The dispersion coating solution is applied to the surface of the intermediate layer after step S3 to obtain a multi-component composite coating anode plate with a surface thickness of 2~3μm.

3. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S1, the acid etching solution is hydrofluoric acid, nitric acid and deionized water in a volume ratio of (0.5~0.8):(1.5~2.0):(5~7).

4. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S2, during the vacuum plasma spraying process, the working current is 450~500A, the working voltage is 60~70V, the argon pressure is 0.7~0.8MPa, the powder feeding rate is 10~15g / min, and the spraying distance is 150~200mm.

5. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S2, the thickness of the bottom layer is 5~10μm.

6. The method for preparing the multi-element composite coated anode plate according to claim 2, characterized in that, In step S3, the heat treatment conditions are as follows: heating to 590~610℃ at a rate of 5℃ / min, holding at that temperature for 60~80min, and cooling to room temperature in the furnace, while maintaining a low oxygen partial pressure atmosphere.

7. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S3, the thickness of the intermediate layer is 2~5μm.

8. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S4, the weight ratio of chloroiridic acid, tantalum pentachloride, pretreated fluorine-doped SnO2 and solvent is (2~6):(1~3):(0.3~0.6):(30~40).

9. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, In step S4, the solvent is n-butanol and isopropanol in a volume ratio of 1:

1.

10. The method for preparing the multi-component composite coated anode plate according to claim 2, characterized in that, Step S4 further includes: applying 0.5~0.8 mL / cm³ each time. 2 After each coating, the sample is dried under an infrared lamp for 5 minutes, then transferred to a muffle furnace for thermal decomposition and sintering at 500°C for 10-15 minutes. The coating, drying, and sintering process is repeated 8-12 times. Finally, the sample is held at 500°C for 60 minutes for final heat treatment and then cooled to room temperature in the furnace.

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