Electrolytic copper foil anode plate electrode and preparation process thereof

Abstract

The invention relates to an electrolytic copper foil anode plate electrode and a preparation process thereof, and belongs to the technical field of electrolytic copper foil production. The electrolytic copper foil anode plate electrode sequentially comprises a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 oxide composite coating from inside to outside. The preparation process comprises the following steps: firstly, forming a micron-sized rough surface by utilizing acetone and ethanol ultrasonic cleaning and oxalic acid etching; the transition layer is subjected to sol dispersion and sintering treatment through polyethylene glycol, so that the balance of low porosity and high bonding strength is realized; the composite coating adopts an acetylacetone-ethylene glycol monomethyl ether solvent system, and a nanocrystalline structure is formed through step-by-step sintering; and an Ir-rich passivation layer is generated through electrochemical activation, and the finally obtained anode plate electrode has more excellent electrochemical activity and longer service life.

Description

Technical Field

[0001] The invention belongs to the technical field of electrolytic copper foil production, and relates to an electrolytic copper foil anode plate electrode and a preparation process thereof. Background Art

[0002] Electrolytic copper foil is a core material in fields such as lithium-ion batteries and printed circuit boards. The performance of the anode plate during its production directly affects the uniformity, conductivity, and energy consumption of the copper foil. Traditional lead anodes have the following drawbacks: The high electrode potential of the lead anode results in high energy consumption during the electrolysis process; the copper foil is deposited unevenly, and at high current densities, the lead anode surface easily peels off, forming an irregular morphology that affects the quality of the copper foil; and the lead anode is easily corroded in acidic electrolytes, shortening its service life.

[0003] Although the existing precious metal-coated titanium anode can partially solve the above problems, it still has the following shortcomings: the surface of the titanium substrate is smooth and it is difficult to form sufficient roughness, which makes the coating easy to fall off; although the single RuO2 coating has high oxygen evolution activity, it is easily dissolved in acidic electrolyte; although IrO2 has excellent stability, its conductivity is relatively insufficient; the thermal expansion coefficient of the traditional transition layer and the titanium substrate is greatly different, and the interface stress is concentrated after high-temperature sintering, which causes the coating to crack.

[0004] Therefore, there is an urgent need for an electrolytic copper foil anode plate electrode and a preparation process thereof. Summary of the Invention

[0005] In view of the shortcomings of the prior art, the present invention aims to provide an electrolytic copper foil anode plate electrode and a preparation process thereof.

[0006] The purpose of the present invention can be achieved through the following technical solutions: An electrolytic copper foil anode plate electrode comprises, from the inside to the outside, a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 ternary oxide composite coating.

[0007] A preparation process for an electrolytic copper foil anode plate electrode, wherein the specific steps of the preparation process are as follows: S1: The titanium substrate was ultrasonically cleaned with acetone and ethanol in sequence, and then ultrasonically treated with a 10-15% mass fraction oxalic acid solution at 80-90 °C for 1-2 h to obtain a pretreated titanium substrate; S2: Iridium trichloride, tantalum pentachloride, and niobium pentachloride are mixed and added to solvent A to prepare sol B with a solid-liquid mass ratio of 1:(18-20). Sol B is coated on the surface of the pretreated titanium substrate, dried in vacuum at 100-120°C, and sintered for 1-2 h to obtain a transition layer. S3: Iridium trichloride, ruthenium trichloride, and tin tetrachloride are mixed and added to solvent C to prepare sol D with a solid-liquid mass ratio of 1:(18-20). Sol D is coated on the surface of the transition layer and sintered step by step to obtain an electrode with a composite coating; S4: The electrode with the composite coating is transferred to a 0.5 M sulfuric acid solution, treated at a constant pressure for 10 to 20 minutes, then washed with deionized water and dried at 60° C. for 12 hours to obtain the electrolytic copper foil anode plate electrode.

[0008] As a preferred technical solution of the present invention, the ultrasonic frequency in S1 is 40-50 kHz, and the power density is 0.6-0.8 W / cm 2 .

[0009] As a technical preferred solution of the present invention, iridium trichloride, tantalum pentachloride and niobium pentachloride in S2 are mixed in a molar ratio of (7-8): (2-3): (0.1-0.2).

[0010] As a technical preferred solution of the present invention, the solvent A in S2 is a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate, polyethylene glycol and ethanol in a mass ratio of 1: (2-3): (8-10).

[0011] As a technical preferred solution of the present invention, the sintering temperature in S2 is 480-500°C.

[0012] As a technical preferred solution of the present invention, iridium trichloride, ruthenium trichloride and tin tetrachloride in S3 are mixed in a molar ratio of (2-3):1:1.

[0013] As a technical preferred solution of the present invention, the solvent C in S3 is a mixture of ethylene glycol methyl ether, acetylacetone and lactic acid in a mass ratio of (47-49): (5-10): (1-3).

[0014] As a technical preferred solution of the present invention, the step-by-step sintering step in S3 is first heating to 250-280°C for pre-sintering for 30 minutes, then heating to 450-470°C for sintering for 1 hour, and finally heating to 500-520°C for sintering for 10-20 minutes.

[0015] As a technical preferred solution of the present invention, the constant voltage condition in S4 is 1.75~1.85V.

[0016] First, the pretreatment step uses ultrasonic cleaning with acetone and ethanol in sequence. Acetone quickly penetrates and dissolves non-polar oil stains based on the principle of like dissolves like, while ethanol further removes polar residues through hydrogen bonding. Subsequently, oxalic acid etching is used to form a uniform micron-scale concave-convex surface structure on the titanium substrate, effectively improving the adhesion of subsequent coatings.

[0017] The high conductivity of IrO2 effectively reduces interfacial contact resistance, while Ta2O5 matches the thermal expansion coefficient of the titanium substrate, resulting in a strong bond. Niobium doping reduces interfacial stress and refines the grain size, reducing porosity in the transition layer and improving the electrode's corrosion resistance. The subsequent sintering process ensures the oxidation of IrCl3 and TaCl5 to form crystals of IrO2 and Ta2O5, promoting the formation of a Ti-O-Ta chemical bond between the transition layer and the titanium substrate, resulting in a strong bond.

[0018] 1-Ethyl-3-methylimidazolium tetrafluoroborate reduces the dispersed particle size of the metal precursor through ion-dipole interactions. The low volatility of the ionic liquid slows the solvent evaporation rate, increasing the spreading coefficient of Sol B on the titanium substrate surface. It also enhances the conductive network, forming carbonized residues during sintering, which reduces the resistivity of the transition layer. Polyethylene glycol and the ionic liquid exhibit a synergistic effect, forming a micellar structure that inhibits Ostwald ripening of the metal oxide particles. The difference in boiling points between ethanol and the ionic liquid results in a step-by-step volatilization process, with ethanol evaporating preferentially. The residual ionic liquid completely decomposes during the sintering stage, reducing the surface tension of the mixed solvent and improving wettability on the titanium substrate.

[0019] RuO2 in the composite coating provides active sites for oxygen evolution reaction, IrO2 further improves conductivity, and SnO2 has a stabilizing effect, which can effectively inhibit the dissolution of RuO2. The ternary system has excellent corrosion resistance and can effectively extend the service life of the electrode. The first stage of sintering realizes the decomposition of organic matter and avoids the sudden release of gas at high temperature and the generation of bubbles; the second stage of heating promotes the formation of ternary oxide grains; the last stage of heating promotes grain density through grain boundary migration, increasing hardness while retaining the nanocrystalline structure. Electrochemical activation treatment removes unstable Ru substances on the surface and generates an Ir-rich passivation layer, which increases the catalytic active area. The subsequent deionized water washing step can further remove residual chloride ions and avoid the risk of local corrosion.

[0020] Solvent C is a mixture of ethylene glycol methyl ether, acetylacetone, and lactic acid in a mass ratio of (47-49): (5-10): (1-3). Tin tetrachloride is very susceptible to hydrolysis, which is the main reason for the instability of traditional sols and uneven coating composition. Lactic acid, as a medium-strength organic acid, can provide a stable acidic environment and effectively inhibit Sn tetrachloride hydrolysis. 4+ Lactic acid and acetylacetone have a synergistic chelating effect: the carboxyl and hydroxyl groups in the lactic acid molecule also have excellent coordination ability, which can synergize with acetylacetone and Ru 3+ 、Ir 3+ 、Sn 4+The formation of a more stable mixed ligand complex further prevents the pre-agglomeration of metal ions in the solution. The ternary solvent evaporation gradient achieves uniform stress release during the coating drying process and improves the coating density.

[0021] Beneficial effects of the present invention: The present invention adopts acetone-ethanol synergistic ultrasonic cleaning in the pretreatment stage, which effectively removes oil stains through similar phase dissolution and hydrogen bonding, and forms a micron-scale rough surface in combination with oxalic acid etching, thereby improving adhesion. The high conductivity of IrO2 in the transition layer reduces the interface resistance, Ta2O5 matches the thermal expansion coefficient of the titanium substrate, and Nb element doping refines the grains, thereby reducing porosity and improving corrosion resistance. Solvent A innovatively adopts an ionic liquid-polyethylene glycol-ethanol composite system to refine the metal precursor particle size through ion-dipole interaction, and improves the coating uniformity through step volatilization control and surface tension optimization. At the same time, carbonization residues reduce the resistivity of the transition layer. The composite coating is synergistic through the ternary RuO2-IrO2-SnO2. RuO2 provides hydrogen evolution active sites, and the SnO2 solid solution inhibits the dissolution of RuO2. Combined with the conductivity of IrO2, the electrode material has good catalytic activity and service life, and can effectively reduce energy consumption during use. Solvent C is synergistic through ethylene glycol methyl ether-acetylacetone-lactic acid. Lactic acid inhibits Sn 4+ Hydrolyzes and chelates metal ions, and a ternary volatilization gradient releases stress, increasing coating density, reducing porosity, and extending electrode life. The step-by-step sintering process prevents bubble formation, promotes the formation of RuO2-IrO2-SnO2 oxide grains, and promotes grain densification. Post-treatment electrochemical activation generates an Ir-rich passivation layer, increasing the catalytically active area. DETAILED DESCRIPTION

[0022] In order to further illustrate the technical means and effects adopted by the present invention to achieve the predetermined purpose of the invention, the specific implementation methods, structures, features and effects of the present invention are described in detail below in combination with the embodiments.

[0023] In the Examples of the present invention and the Comparative Examples: Titanium substrate: purchased from Beijing Xingrongyuan Technology Co., Ltd., with a thickness of 3 mm.

[0024] Example 1 An electrolytic copper foil anode plate electrode comprises, from the inside to the outside, a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 ternary oxide composite coating.

[0025] A preparation process for an electrolytic copper foil anode plate electrode, wherein the specific steps of the preparation process are as follows: S1: The titanium substrate was ultrasonically cleaned with acetone and ethanol in sequence, and then ultrasonically cleaned with 12% oxalic acid solution at 85°C for 1.5 h, with an ultrasonic frequency of 45 kHz and a power density of 0.7 W / cm 2 , obtaining a pretreated titanium substrate; S2: Iridium trichloride, tantalum pentachloride, and niobium pentachloride were mixed in a molar ratio of 7.5:2.5:0.15 and added to solvent A to prepare sol B with a solid-liquid mass ratio of 1:19. Solvent A was a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate, polyethylene glycol-200, and ethanol in a mass ratio of 1:2.5:9. Sol B was coated on the surface of a pretreated titanium substrate, dried in vacuum at 110°C, and sintered for 1.5 h at a sintering temperature of 490°C to obtain a transition layer. S3: Iridium trichloride, ruthenium trichloride, and tin tetrachloride were mixed in a molar ratio of 2.5:1:1 and added to solvent C to prepare sol D with a solid-liquid mass ratio of 1:19. Solvent C was a mixture of ethylene glycol methyl ether, acetylacetone, and lactic acid in a mass ratio of 48:7.5:2. Sol D was coated on the surface of the transition layer and sintered step by step. The step-by-step sintering steps were first pre-sintering at 260°C for 30 minutes, then heating to 460°C for 1 hour, and finally heating to 510°C for 15 minutes to obtain an electrode with a composite coating; S4: The electrode with the composite coating was transferred to a 0.5 M sulfuric acid solution, treated at a constant voltage of 1.85 V for 15 min, then washed with deionized water and dried at 60° C. for 12 h to obtain the electrolytic copper foil anode plate electrode.

[0026] Example 2 An electrolytic copper foil anode plate electrode comprises, from the inside to the outside, a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 ternary oxide composite coating.

[0027] A preparation process for an electrolytic copper foil anode plate electrode, wherein the specific steps of the preparation process are as follows: S1: The titanium substrate was ultrasonically cleaned with acetone and ethanol in sequence, and then ultrasonically cleaned with a 10% mass fraction oxalic acid solution at 80°C for 1 h, with an ultrasonic frequency of 40 kHz and a power density of 0.6 W / cm 2 , obtaining a pretreated titanium substrate; S2: Iridium trichloride, tantalum pentachloride, and niobium pentachloride were mixed in a molar ratio of 7:2:0.1 and added to solvent A to prepare sol B with a solid-liquid mass ratio of 1:18. Solvent A was a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate, polyethylene glycol-200, and ethanol in a mass ratio of 1:2:8. Sol B was coated on the surface of a pretreated titanium substrate, dried in vacuum at 100°C, and sintered for 1 h at a sintering temperature of 500°C to obtain a transition layer. S3: Iridium trichloride, ruthenium trichloride, and tin tetrachloride were mixed in a molar ratio of 2:1:1 and added to solvent C to prepare sol D with a solid-liquid mass ratio of 1:18. Solvent C was a mixture of ethylene glycol methyl ether, acetylacetone, and lactic acid in a mass ratio of 47:5:1. Sol D was coated on the surface of the transition layer and sintered step by step. The step-by-step sintering steps were first pre-sintering at 250°C for 30 minutes, then heating to 450°C for 1 hour, and finally heating to 500°C for 20 minutes to obtain an electrode with a composite coating. S4: The electrode with the composite coating is transferred to a 0.5 M sulfuric acid solution, treated at a constant voltage of 1.75 V for 10 min, then washed with deionized water and dried at 60° C. for 12 h to obtain the electrolytic copper foil anode plate electrode.

[0028] Example 3 An electrolytic copper foil anode plate electrode comprises, from the inside to the outside, a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 ternary oxide composite coating.

[0029] A preparation process for an electrolytic copper foil anode plate electrode, wherein the specific steps of the preparation process are as follows: S1: The titanium substrate was ultrasonically cleaned with acetone and ethanol in sequence, and then ultrasonically cleaned with 15% oxalic acid solution at 90°C for 2 h, with an ultrasonic frequency of 50 kHz and a power density of 0.8 W / cm 2 , obtaining a pretreated titanium substrate; S2: Iridium trichloride, tantalum pentachloride, and niobium pentachloride were mixed in a molar ratio of 8:3:0.2 and added to solvent A to prepare sol B with a solid-liquid mass ratio of 1:20. Solvent A was a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate, polyethylene glycol-200, and ethanol in a mass ratio of 1:3:10. Sol B was coated on the surface of a pretreated titanium substrate, dried in vacuum at 120°C, and sintered for 2 h at a sintering temperature of 500°C to obtain a transition layer. S3: Iridium trichloride, ruthenium trichloride, and tin tetrachloride were mixed in a molar ratio of 3:1:1 and added to solvent C to prepare sol D with a solid-liquid mass ratio of 1:20. Solvent C was a mixture of ethylene glycol methyl ether, acetylacetone, and lactic acid in a mass ratio of 49:10:3. Sol D was coated on the surface of the transition layer and sintered step by step. The step-by-step sintering steps were first pre-sintering at 280°C for 30 minutes, then heating to 470°C for 1 hour, and finally heating to 520°C for 10 minutes to obtain an electrode with a composite coating; S4: The electrode with the composite coating is transferred to a sulfuric acid solution with a concentration of 0.5 M, treated at a constant voltage of 1.85 V for 20 min, then washed with deionized water and dried at 60° C. for 12 h to obtain the electrolytic copper foil anode plate electrode.

[0030] Comparative Example 1 In S1, the ultrasonic treatment with the oxalic acid solution was not performed, and the remaining steps were the same as those in Example 1.

[0031] Comparative Example 2 No niobium pentachloride was added to S2, and the remaining steps were the same as those in Example 1.

[0032] Comparative Example 3 Polyethylene glycol-200 was not added in S2, and the remaining steps were the same as those in Example 1.

[0033] Comparative Example 4 No 1-ethyl-3-methylimidazolium tetrafluoroborate was added to S2, and the remaining steps were the same as those in Example 1.

[0034] Comparative Example 5 No acetylacetone was added in S3, and the remaining steps were the same as in Example 1.

[0035] Comparative Example 6 Lactic acid was not added in S3, and the remaining steps were the same as in Example 1.

[0036] Comparative Example 7 In S3, iridium trichloride, ruthenium trichloride, and tin tetrachloride are mixed in a molar ratio of 1:1:1, and the remaining steps are the same as those in Example 1.

[0037] Comparative Example 8 In S3, the step-by-step sintering was changed to one-step sintering, and the sintering was directly performed at 510° C. for 2 h. The remaining steps were the same as those in Example 1.

[0038] Catalytic activity test The electrodes prepared in the examples and comparative examples were used as working electrodes, platinum sheets as counter electrodes, and Ag / AgCl as reference electrodes. Scanning was performed in 1 M H2SO4 at a scan rate of 5 mV / s. The test was performed at a current density of 10 mA / cm 2The overpotential for hydrogen evolution at .

[0039] Accelerated life testing Accelerated life test was conducted in 150 g / L H2SO4 test solution at a current density of 40000 A / m 2 The test temperature is 40 ℃, and the anode is judged to be failed when the voltage rises by 5 V.

[0040] The specific experimental results are summarized in the following table.

[0041]

[0042] The data from the examples and comparative examples show that the hydrogen evolution overpotentials of Examples 1-3 of the present invention are significantly lower than those of all the comparative examples, and the accelerated lifespans of Examples 1-3 are improved compared to the comparative examples, indicating that the present invention significantly enhances the hydrogen evolution catalytic activity and extends the service life of the electrode through the coordinated design of the transition layer, ternary composite coating, and step-by-step sintering process. This is mainly due to the pretreatment process increasing the bonding strength between the titanium substrate and the coating; Nb doping refines the grains and reduces interfacial stress, inhibiting the propagation of microcracks; the chelation effect of acetylacetone in the lactic acid-acetylacetone-ethylene glycol methyl ether solvent system effectively inhibits the hydrolysis of SnCl4 and improves the uniformity of the coating; and the step-by-step sintering process can effectively promote grain densification compared to the one-step sintering process.

[0043] The above description is merely a preferred embodiment of the present invention and does not constitute any form of limitation to the present invention. Although the present invention has been disclosed as a preferred embodiment as above, it is not intended to limit the present invention. Any person skilled in the art can make some changes or modifications to equivalent embodiments using the technical contents disclosed above without departing from the scope of the technical solution of the present invention. However, any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. An electrolytic copper foil anode plate electrode, characterized in that: The electrolytic copper foil anode plate electrode comprises, from the inside to the outside, a titanium substrate, an Ir-Ta oxide transition layer and an IrO2-RuO2-SnO2 oxide composite coating.

2. A process for preparing an electrolytic copper foil anode plate electrode as claimed in claim 1, characterized in that: The specific steps of the preparation process are as follows: S1: The titanium substrate was ultrasonically cleaned with acetone and ethanol in sequence, and then ultrasonically treated with a 10-15% mass fraction oxalic acid solution at 80-90°C for 1-2 h to obtain a pretreated titanium substrate; S2: Iridium trichloride, tantalum pentachloride, and niobium pentachloride are mixed and added to solvent A to prepare sol B with a solid-liquid mass ratio of 1:(18-20). Sol B is coated on the surface of the pretreated titanium substrate, dried in vacuum at 100-120°C, and sintered for 1-2 h to obtain a transition layer. S3: Iridium trichloride, ruthenium trichloride, and tin tetrachloride are mixed and added to solvent C to prepare sol D with a solid-liquid mass ratio of 1:(18-20). Sol D is coated on the surface of the transition layer and sintered step by step to obtain an electrode with a composite coating; S4: The electrode with the composite coating is transferred to a 0.5 M sulfuric acid solution, treated at a constant pressure for 10 to 20 minutes, then washed with deionized water and dried at 60° C. for 12 hours to obtain the electrolytic copper foil anode plate electrode.

3. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The ultrasonic frequency in S1 is 40-50 kHz, and the power density is 0.6-0.8 W / cm 2 .

4. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: In the S2, iridium trichloride, tantalum pentachloride and niobium pentachloride are mixed in a molar ratio of (7-8): (2-3): (0.1-0.2).

5. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The solvent A in S2 is a mixture of 1-ethyl-3-methylimidazolium tetrafluoroborate, polyethylene glycol and ethanol in a mass ratio of 1: (2-3): (8-10).

6. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The sintering temperature in S2 is 480-500°C.

7. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: In the S3, iridium trichloride, ruthenium trichloride and tin tetrachloride are mixed in a molar ratio of (2-3):1:

1.

8. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The solvent C in S3 is a mixture of ethylene glycol methyl ether, acetylacetone and lactic acid in a mass ratio of (47-49): (5-10): (1-3).

9. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The stepwise sintering steps in S3 are: firstly heating to 250-280°C for pre-sintering for 30 min, then heating to 450-470°C for sintering for 1 h, and finally heating to 500-520°C for sintering for 10-20 min.

10. The process for preparing an electrolytic copper foil anode plate electrode according to claim 2, characterized in that: The constant voltage condition in S4 is 1.75~1.85 V.

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