Titanium anode, titanium anode preparation method, electrolytic copper foil and application

Abstract

The invention provides a titanium anode, a titanium anode preparation method, an electrolytic copper foil and application. The titanium anode comprises a titanium substrate and a composite layer on the surface of the titanium substrate. The composite layer comprises a first active layer and a second active layer which are sequentially arranged on the titanium substrate, and the first active layer is arranged on the surface of the titanium substrate; wherein the first active layer includes an oxide of titanium and an oxide of tantalum, and the second active layer includes an oxide of tantalum, an oxide of iridium, and an oxide of cerium. The titanium anode provided by the invention has the characteristics of strong binding force, few cracks, high electrocatalytic activity, good uniformity, good erosion resistance and the like, and is beneficial to prolonging the service life.

Description

Technical Field

[0001] The present application relates to the technical field of electrolytic copper foil titanium anodes, and in particular to a titanium anode, a method for preparing a titanium anode, an electrolytic copper foil, and applications. Background Art

[0002] Electrolytic copper foil is a key basic material for the manufacture of electronic components such as copper clad laminates, printed circuit boards, and lithium-ion batteries. It is known as the "neural network" for signal and power transmission and communication in electronic products. Electrolytic copper foil uses electrolysis to cause the copper ions in the electrolyte to undergo a reduction reaction on the cathode surface, depositing to form high-purity copper foil. During the electrolysis process, an oxidation reaction occurs at the anode, and the anode copper plate dissolves under the action of the electric field, leaving Cu 2+ It enters the electrolyte in the form of copper ions, continuously replenishing the copper ion concentration in the electrolyte and ensuring the stability of the electrolytic system.

[0003] Electrolytic copper foil anodes are an integral part of the production process. Their quality and stability directly impact the quality and production efficiency of the copper foil. Titanium anodes for electrolytic copper foil offer higher electrocatalytic performance, less anode slag, more stable electrode spacing, and longer service life, playing a key role in the uniformity of the copper foil product and the stability of the electrolysis process.

[0004] Patent CN117568878A discloses a titanium anode and electrolytic copper foil production equipment. The titanium anode comprises a titanium substrate and an active layer on its surface, the active layer comprising a precious metal oxide and an additive; the precious metal oxide comprises iridium oxide and tantalum oxide; and the additive comprises a hydroxyalkylethylenediamine additive.

[0005] Patent CN114752971A discloses a method for preparing a coated titanium anode with high electrolytic durability, comprising: S1: pre-treating the surface of a titanium substrate; S2: sequentially preparing a first intermediate layer M1 and a second intermediate layer M2 on the upper and / or lower surface of the titanium substrate treated in S1 by laser additive manufacturing technology;

[0006] S3: The first catalytic layer C1 is coated and calcined on the surface of the titanium substrate treated in S2; S4: The second catalytic layer C2 is coated and calcined on the surface of C1 treated in S3; S5: S3 and S4 are repeated alternately until the total thickness of the catalytic coating layer alternately coated with C1 and C2 is 2 to 10 μm.

[0007] In the prior art, titanium anodes are coated with a coating solution containing metal ions of iridium (Ir) and tantalum (Ta) and then calcined to form an active composite layer on the titanium substrate. However, the titanium anodes produced using this method suffer from poor uniformity, poor adsorption properties of the active composite layer, numerous cracks, and coarse grains, which affect the performance and service life of the titanium anode. Summary of the Invention

[0008] The embodiments of the present application provide a titanium anode, a method for preparing a titanium anode, an electrolytic copper foil, and applications thereof, which improve the uniformity of the titanium anode, the adsorption of the active composite layer, and refine the grains of the composite layer.

[0009] In a first aspect, an embodiment of the present application provides a titanium anode, comprising:

[0010] Titanium matrix;

[0011] A composite layer, the composite layer comprising a first active layer and a second active layer sequentially disposed on the titanium substrate, wherein the first active layer is disposed on a surface of the titanium substrate;

[0012] The first active layer includes titanium oxide and tantalum oxide, and the second active layer includes tantalum oxide, iridium oxide and cerium oxide.

[0013] In an optional embodiment, the content of tantalum in the first active layer is 3 to 5 g / m 2 The molar ratio of titanium to tantalum in the first active layer is 7:2-4.

[0014] In an optional embodiment, the iridium content in the second active layer is 25-27 g / m 2 The molar ratio of iridium to tantalum in the second active layer is 6:5 to 4:1, and the molar ratio of iridium to cerium in the second active layer is 21:5 to 22:3.

[0015] In an optional embodiment, a protective layer is provided on the side of the second active layer away from the titanium substrate, wherein the protective layer comprises ruthenium oxide, wherein the content of ruthenium in the protective layer is 2 to 3 g / m 2 .

[0016] In a second aspect, the present application also provides a method for preparing a titanium anode, which is used to prepare the above-mentioned titanium anode, comprising the following steps:

[0017] Applying a first coating liquid to the surface of the titanium substrate and calcining to form the first active layer, wherein the first coating liquid includes tantalum salt and butyl titanate;

[0018] A second coating liquid is applied to the surface of the first active layer and calcined to form the second active layer. The second coating liquid includes tantalum salt, cerium salt, chloroiridic acid and mixed additives. The mixed additives include N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol.

[0019] In an optional embodiment, the first coating liquid is prepared by adding hydrochloric acid and the butyl titanate to a tantalum pentachloride n-butanol solution;

[0020] Preferably, the concentration of the tantalum pentachloride n-butanol solution is 0.05 to 0.09 mol / L;

[0021] Preferably, the molar ratio of the butyl titanate to the tantalum pentachloride n-butanol solution is 7:2-4.

[0022] In an optional embodiment, preparing the second coating solution comprises the following steps:

[0023] Dissolve the chloroiridic acid solution in the isopropanol solution to obtain solution A;

[0024] Dissolve the tantalum pentachloride n-butanol solution in the n-butanol solution to obtain solution B;

[0025] The solution A and the solution B are mixed to obtain a mixed solution, and hydrochloric acid, N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol and cerium chloride are added to the mixed solution to obtain the second coating solution.

[0026] Preferably, in the solution A, the concentration of the chloroiridic acid solution is 0.15 to 0.20 mol / L; in the solution B, the concentration of the tantalum pentachloride n-butanol solution is 0.05 to 0.125 mol / L;

[0027] Preferably, in the mixed solution, the volume ratio of the solution A to the solution B is 1:1; the volume ratio of the mixed solution to the hydrochloric acid is 18-22:0.8-1.2, wherein the mass fraction of the hydrochloric acid is 37%;

[0028] Preferably, the mass ratio of the total mass of the N,N-dimethylformamide, the N,N-dimethylacetamide and the polyvinyl alcohol to the chloroiridic acid is 0.8-1.2:4-8;

[0029] Preferably, the volume ratio of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol is 0.8-1.2:0.9-1.1:1;

[0030] Preferably, the concentration of the cerium chloride in the second coating solution is 0.013-0.017 mol / L.

[0031] In an optional embodiment, during the preparation of the second active layer, the second coating liquid is applied to the surface of the first active layer multiple times and calcined, and the molar ratio of iridium to tantalum of the second coating liquid is reduced successively each time.

[0032] In an optional embodiment, the titanium anode preparation method further includes: applying a third coating liquid to the surface of the second active layer, and calcining to form the protective layer, wherein the third coating liquid includes a ruthenium salt.

[0033] In an optional embodiment, preparing the third coating solution comprises the following steps:

[0034] Dissolving ruthenium trichloride and butyl titanate in n-butanol solution, adding hydrochloric acid, and mixing to obtain the third coating solution;

[0035] Preferably, the volume ratio of n-butanol solution to hydrochloric acid is 8-12:0.9-1.1, wherein the mass fraction of the hydrochloric acid is 37%;

[0036] Preferably, the mass volume ratio of the ruthenium trichloride, butyl titanate and n-butanol solution is 3-4:10-11:44-53.

[0037] In an optional embodiment, before coating the titanium substrate with the first coating liquid, pre-treating the titanium substrate comprises the following steps:

[0038] The titanium plate is sequentially subjected to sandblasting and acid treatment, and then the titanium plate is cleaned and baked to obtain the titanium substrate;

[0039] Preferably, the surface roughness of the titanium plate after the sandblasting treatment is 11 to 13 μm;

[0040] Preferably, the acid treatment comprises the following steps: soaking the titanium plate after sandblasting in a hydrochloric acid solution with a concentration of 10±3%, and then soaking the titanium plate in an oxalic acid solution with a concentration of 10±3% for etching for 0.5 to 2 hours, and the oxalic acid solution is in a boiling state to remove impurities on the surface of the titanium plate;

[0041] Preferably, the baking time of the titanium plate is 1.5 to 2 hours, and the baking temperature is 150 to 200°C.

[0042] In a third aspect, the present application provides an electrolytic copper foil, which includes the above-mentioned titanium anode or a titanium anode prepared by the above-mentioned titanium anode preparation method.

[0043] Fourthly, the present application also provides an application of electrolytic copper foil in electronic devices, and the electrolytic copper foil is used in the fields of copper clad laminates, printed circuit boards and lithium-ion batteries.

[0044] The present application provides a titanium anode, a method for preparing a titanium anode, an electrolytic copper foil, and applications thereof. The first active layer in the titanium anode is formed by titanium oxide and tantalum oxide, thereby improving the bonding strength of the first active layer. The second active layer is formed by tantalum oxide, iridium oxide, and cerium oxide, thereby improving the uniformity of the distribution of metal oxides in the composite layer, reducing cracks on the surface of the second active layer, and refining the oxide grains in the second active layer.

[0045] The titanium anode preparation method of the embodiment of the present application is to coat the surface of the titanium substrate with a second coating liquid containing butyl titanate, and calcining to form a first active layer TiOx -Ta2O5, butyl titanate enhances the wettability of the coating liquid to the titanium substrate, helps to reduce the shrinkage or accumulation of droplets produced during spraying, ensures that the coating is evenly distributed on the substrate surface, and forms a solid substrate protective layer after calcination.

[0046] In the titanium anode preparation method of the embodiment of the present application, a mixed additive containing N,N-dimethylformamide, N,N-dimethylacetamide, and polyvinyl alcohol and a cerium salt are coated on the surface of the first active layer, and calcined to form a second active layer; the mixed additive can make the metal oxide uniformly distributed in the composite layer, reduce the cracks on the surface of the second active layer and the size of the cracks; the cerium salt can refine the oxide grains in the second active layer and increase the active specific surface area of the titanium anode.

[0047] Furthermore, the titanium anode preparation method of the embodiment of the present application coats a third coating solution containing ruthenium salt on the outside of the second active layer and calcines it to form a protective layer. The ruthenium salt can form a ruthenium oxide protective layer during the calcination process, which can effectively reduce the corrosion of the electrolyte on the titanium anode and extend the service life of the titanium anode.

[0048] In addition, in the embodiment of the present application, during the pretreatment of the titanium plate, the internal stress is eliminated by baking the titanium plate at a high temperature, which can increase the surface activation energy of the titanium plate and thus enhance the adsorption capacity of the titanium substrate surface. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments consistent with the present application and, together with the description, serve to explain the principles of the present application.

[0050] Figure 1 This is an SEM image of the electrolytic copper foil titanium anode provided in the embodiment of the present application;

[0051] Figure 2 This is an SEM image of the electrolytic copper foil titanium anode provided in Comparative Example 1 of this application;

[0052] Figure 3 This is an SEM image of the electrolytic copper foil titanium anode provided in Comparative Example 2 of this application;

[0053] Figure 4 This is an SEM image of the electrolytic copper foil titanium anode provided in Comparative Example 3 of this application;

[0054] Figure 5 This is an SEM image of the electrolytic copper foil titanium anode provided in Comparative Example 4 of this application;

[0055] Figure 6 Oxygen evolution potential diagram of the electrolytic copper foil titanium anode provided in Examples and Comparative Examples 1 to 4 of the present application;

[0056] Figure 7CV comparison chart of the electrolytic copper foil titanium anode provided in the embodiment of the present application and comparative examples 1 to 4;

[0057] Figure 8 This is a bar chart of the electrolytic strengthening life of the electrolytic copper foil titanium anode provided in the examples of the present application and comparative examples 1 to 4.

[0058] The above drawings illustrate specific embodiments of the present application, which will be described in more detail below. These drawings and the textual description are not intended to limit the scope of the present application in any way, but rather to illustrate the concepts of the present application to those skilled in the art by reference to specific embodiments. DETAILED DESCRIPTION

[0059] The following specific embodiments describe in detail the technical solution of the present application and how the technical solution of the present application solves the above-mentioned technical problems. The following specific embodiments can be combined with each other, and the same or similar concepts or processes may not be repeated in some embodiments. The embodiments of the present application will be described below in conjunction with the accompanying drawings.

[0060] In the field of electrolytic copper foil production, titanium anodes are widely used due to their corrosion resistance and catalytic properties. In the traditional process, iridium salts and tantalum salts are dissolved in alcohol solvents to prepare a coating liquid, and a brush is applied in combination with high-temperature calcination to form an active composite layer. However, the applicant found in the study that the relevant technology has the following problems: the temperature of the titanium substrate is low before coating, and the surface activation energy is insufficient, resulting in the failure to eliminate internal stress and poor adsorption of the coating liquid, which affects the adhesion of the coating; during the high-temperature calcination of the coating liquid, the catalytic layer is prone to cracks due to differences in thermal expansion coefficients; and brushing is prone to surface accumulation, resulting in uneven metal distribution; in addition, the iridium tantalum oxide grains are coarse, resulting in insufficient electrochemical active sites and limited doping control means; in addition, the anode is immersed in copper sulfate electrolyte for a long time, and the iridium tantalum catalyst layer is easily electrochemically corroded, shortening its service life.

[0061] Based on this, the present application provides a titanium anode, a titanium anode preparation method, an electrolytic copper foil and applications.

[0062] In the process of preparing titanium anode, the internal stress of titanium plate is eliminated by high temperature baking, the surface activation energy is increased, and the adsorption of coating liquid is enhanced. The first coating liquid containing butyl titanate is coated on the surface of titanium substrate and calcined to form the first active layer (TiO x-Ta2O5), alleviate thermal stress mismatch, and enhance the bonding strength of the first active layer. A second coating solution containing a mixed additive is coated on the surface of the first active layer and calcined to form a second active layer (Ta2O5-CeO2-IrO2). The mixed additives include N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol, which help improve the leveling of the second coating solution and reduce cracking and component segregation of the composite layer. At the same time, cerium salt is added to the second coating solution to inhibit high-temperature grain coarsening and refine the CeO2-IrO2 grains. In addition, a protective layer containing ruthenium oxide is provided on the second active layer, and the high corrosion resistance of ruthenium oxide is used to block electrolyte erosion and extend the life of the anode.

[0063] In summary, the titanium anode (Ti / TiO x -Ta2O5 / Ta2O5-CeO2-IrO2 / RuO y ), has the characteristics of strong bonding force, few cracks, high electrocatalytic activity, good uniformity, and good corrosion resistance, thereby effectively improving the service life of the electrode.

[0064] Explanation of the terms appearing in this application:

[0065] Roughness Ra refers to the unevenness of the machined surface, characterized by small peaks and valleys. The distance between two peaks or valleys (wave pitch) is very small, generally less than 1 mm, and difficult to distinguish with the naked eye. This is a microscopic geometric error. The smaller the surface roughness, the smoother the surface.

[0066] The reagents, instruments, and materials used in this application can all be obtained through commercial channels.

[0067] In a first aspect, an embodiment of the present application provides a titanium anode, comprising a titanium substrate and a composite layer on its surface, the composite layer comprising a first active layer and a second active layer sequentially arranged on the titanium substrate, the first active layer being arranged on the surface of the titanium substrate; wherein the first active layer comprises titanium oxide and tantalum oxide, and the second active layer comprises tantalum oxide, iridium oxide and cerium oxide.

[0068] Titanium, as the anode matrix material, has high specific strength, corrosion resistance and electrical conductivity.

[0069] A first active layer is provided on the surface of the titanium substrate. The first active layer serves as an intermediate layer, which can protect the titanium substrate and avoid direct exposure thereof, and plays the role of thermal stress buffering and enhancing bonding strength.

[0070] The first active layer includes titanium oxide and tantalum oxide. Titanium oxide (TiO x) may be one or more of titanium dioxide (TiO2), titanium monoxide (TiO), titanium trioxide (Ti2O3), titanium tetraoxide (Ti3O4), and titanium heptoxide (Ti4O7). The tantalum oxide may be tantalum pentoxide (Ta2O5).

[0071] Illustratively, the titanium dioxide (TiO 2 ) may be rutile titanium dioxide, anatase titanium dioxide, or brookite titanium dioxide.

[0072] A second active layer is applied to the surface of the first active layer. This second active layer acts as a catalytic layer and participates in the electrochemical process. The second active layer comprises tantalum oxide, iridium oxide, and cerium oxide. Iridium oxide is a highly efficient catalyst that acts as an active site, helping to reduce the reaction overpotential. Cerium oxide acts as a grain boundary pinning agent, inhibiting grain coarsening during high-temperature calcination of the iridium oxide, increasing the specific surface area and helping to expose more active sites. Tantalum oxide is highly stable in acidic environments and can form a solid solution with iridium oxide, helping to inhibit dissolution loss of iridium oxide in the electrolyte and extending anode life.

[0073] For example, the iridium oxide may be iridium dioxide (IrO 2 ), the tantalum oxide may be tantalum pentoxide (T 2 O 5 ), and the cerium oxide may be cerium dioxide (CeO 2 ).

[0074] In an optional embodiment, the content of tantalum in the first active layer is 3 to 5 g / m 2 The molar ratio of titanium to tantalum in the first active layer is 7:(2-4), which helps to improve the bonding strength of the first active layer and reduce coating cracking.

[0075] In an optional embodiment, the iridium content in the second active layer is 25-27 g / m 2 The molar ratio of iridium to tantalum in the second active layer is (6:5) to (4:1), and the molar ratio of iridium to cerium in the second active layer is (21:5) to (22:3). The appropriate molar ratio of iridium to cerium in the active layer helps improve the second electrochemical performance and refine the grain size, resulting in a smaller starting point for the titanium anode.

[0076] In this embodiment, the molar ratio of the metal ions iridium and tantalum in the second active layer is controlled between (6:5) and (4:1), which helps improve the electrochemical performance of the titanium anode. The molar ratio of iridium and cerium in the second active layer is controlled between (21:5) and (22:3), which can improve the electrochemical activity of the titanium anode and effectively reduce the grain size.

[0077] In an optional embodiment, a protective layer is provided on the side of the second active layer away from the titanium substrate, and the protective layer comprises ruthenium oxide, wherein the content of ruthenium in the protective layer is 2 to 3 g / m 2The present invention provides a ruthenium oxide protective layer on the side away from the titanium substrate, which effectively protects the second active layer, reduces electrolyte corrosion on the titanium anode, and extends the service life of the titanium anode. Exemplarily, the ruthenium oxide is ruthenium dioxide.

[0078] It should be noted that the measurement of the metal content in the first active layer, the second active layer and the protective layer includes but is not limited to measurement by atomic absorption spectroscopy, inductively coupled plasma optical emission spectroscopy and other means.

[0079] In a second aspect, the present invention also provides a method for preparing a titanium anode, which is used to prepare the above-mentioned titanium anode. The method comprises the following steps:

[0080] S100, applying a first coating liquid to the surface of the titanium substrate and calcining to form a first active layer, wherein the first coating liquid includes tantalum salt and butyl titanate.

[0081] The first coating liquid containing tantalum salt and butyl titanate is applied to the surface of the titanium substrate, and a first active layer covering the surface of the titanium substrate is formed under calcination. The structure of the first active layer is TiO x -Ta2O5.

[0082] Preferably, the first coating solution is prepared by adding hydrochloric acid and butyl titanate to a tantalum pentachloride n-butanol solution.

[0083] Tantalum pentachloride (TaCl5) is used as a tantalum source and dissolved in n-butanol, in which the tantalum element is evenly dispersed; butyl titanate is used as a titanium source and is compounded with tantalum oxide (Ta2O5) under calcination to form an intermediate layer; hydrochloric acid provides an acidic environment to inhibit the premature hydrolysis of butyl titanate and maintain the stability of the coating solution.

[0084] Butyl titanate forms a moderately viscous sol with the alcohols in the first coating solution, allowing it to spread evenly across the titanium substrate during application. This allows for a continuous film to be formed through multiple coats, even at a low concentration, effectively preventing uncovered areas on the titanium substrate. Furthermore, the long organic chains (butoxy groups) in butyl titanate enhance the wettability of the first coating solution on the titanium substrate, helping to reduce droplet shrinkage or accumulation during spraying and ensuring uniform coating coverage.

[0085] During the calcination of the first coating solution, butyl titanate will thermally decompose to generate titanium oxide TiO covering the surface of the titanium substrate. x During the electrolysis process, after the Ir in the titanium anode is consumed, the titanium oxide can prevent the electrolyte from corroding the titanium substrate, thereby protecting the titanium substrate and increasing the service life of the titanium substrate.

[0086] Preferably, the concentration of tantalum pentachloride n-butanol solution is 0.05 to 0.09 mol / L. Within this range, sufficient tantalum content can be ensured to form a continuous Ta2O5 phase after calcination, thereby avoiding a decrease in corrosion resistance of the intermediate layer due to insufficient tantalum; and preventing excessive concentration from causing excessive viscosity of the coating solution, resulting in droplet accumulation or drying stress causing cracks during coating.

[0087] Preferably, the molar ratio of butyl titanate to tantalum pentachloride n-butanol solution is 7:(2-4). If the molar ratio is too low, the bonding strength of the calcined first active layer is weak, and the first active layer is prone to flaking. If the molar ratio is too high, the coating is prone to cracking. Preferably, the mass fraction of hydrochloric acid is 37% to provide a suitable acidic environment for the butyl titanate.

[0088] In the process of obtaining the first active layer, since the concentration of the coating solution is relatively low, in order to ensure better bonding strength, the first active layer is prepared by a method of multiple spraying + calcining, that is, each spraying corresponds to one calcination.

[0089] S200, applying a second coating liquid to the surface of the first active layer and calcining to form a second active layer, the second coating liquid comprising tantalum salt, cerium salt, chloroiridic acid and mixed additives, the mixed additives comprising N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol.

[0090] The second coating liquid is coated on the surface of the first active layer, and the second active layer, namely the catalytic layer (Ta2O5-CeO2-IrO2) is formed under calcination.

[0091] N,N-dimethylformamide and N,N-dimethylacetamide can reduce the surface tension of the coating liquid, enhance the ability of the coating liquid to spread on the surface of the intermediate layer, avoid droplet accumulation or shrinkage during spraying, and reduce cracking caused by drying stress; while polyvinyl alcohol can enhance the mechanical strength of the wet film formed by the coating liquid, preventing cracking due to shrinkage stress during the drying process. Therefore, the present application can synergistically improve the viscosity and rheological properties of the second coating liquid through the mixture of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol, ensure the uniform dispersion of metal salts (Ir, Ce, Ta), avoid component segregation, and form a catalytic layer with uniform chemical composition.

[0092] During the calcination process, the cerium salt in the second coating solution oxidizes Ce ions to CeO2. CeO2 nanoparticles are distributed at the IrO2 grain boundaries, hindering grain migration and merging, contributing to IrO2 grain refinement and increasing the active specific surface area. Furthermore, CeO2 and IrO2 form a heterogeneous structure (CeO2-IrO2), which inhibits IrO2 dissolution in the acidic electrolyte and helps extend the anode life.

[0093] Thus, the second coating solution solves the problems of large cracks in the second coating layer, poor uniformity of the catalytic layer, and large iridium oxide grains through N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol and cerium salt.

[0094] Preferably, the preparation method of the second coating liquid is as follows:

[0095] (1) dissolving the chloroiridic acid solution in the isopropyl alcohol solution to obtain solution A;

[0096] (2) dissolving the tantalum pentachloride n-butanol solution in the n-butanol solution to obtain solution B;

[0097] (3) Solution A and solution B are mixed to obtain a mixed solution, hydrochloric acid, N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol and cerium chloride are added to the mixed solution, and the mixture is mixed to obtain a second coating solution.

[0098] The iridium chloride in solution A provides the Ir element, which forms IrO2 upon calcination, acting as a catalyst. The moderate evaporation rate of isopropyl alcohol ensures uniform spreading of the second coating solution during application, preventing rapid drying and resulting in component segregation. Tantalum pentachloride in solution B is calcined to form Ta2O5, which forms a solid solution with IrO2, inhibiting IrO2 dissolution. n-Butanol, as a high-boiling-point solvent, slows the drying rate of the coating solution and synergistically regulates the evaporation gradient with isopropyl alcohol, optimizing the uniformity of the second coating film. Dinitrogen additives (N,N-dimethylformamide and N,N-dimethylacetamide) help reduce the coating solution's surface tension, improve leveling, and eliminate cracking caused by coating droplet accumulation. Polyvinyl alcohol acts as a binder to enhance wet film strength and decomposes during calcination to form a microporous structure, promoting electrolyte penetration. Cerium chloride is calcined to form CeO2, which helps refine IrO2 grains and enhances its catalytic activity through the regulation of oxygen vacancies.

[0099] Preferably, in solution A, the concentration of the chloroiridic acid solution is 0.15-0.20 mol / L, preferably 0.175 mol / L; in solution B, the concentration of the tantalum pentachloride n-butanol solution is 0.05-0.125 mol / L, preferably 0.07 mol / L.

[0100] Preferably, the volume ratio of solution A to solution B in the mixed solution is 1:1, which helps adjust the Ir:Ta molar ratio so that the coating formed by the second coating solution has good electrochemical properties. The volume ratio is preferably 1:1. The volume ratio of the mixed solution to hydrochloric acid is (18-22):(0.8-1.2), preferably 20:1, wherein the mass fraction of hydrochloric acid is 37%.

[0101] Preferably, the mass ratio of the total mass of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol to chloroiridic acid is (0.8-1.2):(4-8), which helps to ensure wet film strength, prevent drying cracking, optimize leveling, and avoid coating shrinkage. The mass ratio is preferably 1:6.

[0102] Preferably, the volume ratio of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol is (0.8-1.2):(0.9-1.1):1, which helps to regulate the volatilization rate, avoid surface skinning, and enhance the cohesion of the coating liquid. The preferred volume ratio is 1:1:1.

[0103] Preferably, the concentration of cerium chloride in the second coating solution is 0.013 to 0.017 mol / L. If the concentration of cerium chloride is too low, the grain refinement effect will be weak, and if the concentration of cerium chloride is too high, it will easily block the IrO2 active sites, resulting in a decrease in the catalytic activity of the catalyst layer.

[0104] Therefore, by controlling the metal salt concentration, solution ratio, additive ratio and cerium doping amount, it helps to balance catalytic activity and corrosion resistance, refine grains, and improve the uniformity and crack resistance of the second coating, so that the titanium anode has both high catalytic efficiency and long life under extreme working conditions such as strong acid and high current.

[0105] In an optional specific embodiment, in order to further optimize the electrochemical performance of the titanium anode, in the preparation of the second active layer, a second coating solution gradient coating is adopted, and second coating solutions with decreasing iridium-tantalum molar ratios are used in sequence to form the second active layer through multiple coating and calcination.

[0106] Specifically, during the preparation of the second active layer, the second coating solution is applied to the surface of the first active layer multiple times and calcined, with the iridium-tantalum molar ratio of the second coating solution decreasing with each application. For example, second coating solutions with different iridium-tantalum molar ratios are first prepared, preferably with the iridium-tantalum molar ratio in the second coating solution set to 7:(2-5). Setting the iridium-tantalum molar ratio of the second coating solution to 7:(2-5) can effectively improve the electrochemical performance of the titanium anode.

[0107] It can be understood that in the process of forming the second active layer, each time the second coating liquid is applied, calcination is performed accordingly to form a progressive, continuous and compact second active layer.

[0108] The present application adopts multiple thin layer coatings, which is beneficial to reduce the stress of a single coating, and the particles are rearranged more evenly during calcination. The iridium-tantalum composition gradient can reduce the difference in shrinkage rate of each layer and avoid microcracks caused by stress concentration. By reducing the iridium-tantalum ratio of the second coating liquid applied in sequence, the thermal expansion coefficient of the coating formed by each application of the second coating liquid decreases successively, buffering the thermal stress between layers and reducing interface cracking under calcination or high-temperature electrolyte conditions. The high Ir content of the bottom coating provides sufficient active sites for oxygen evolution reaction, reducing overpotential, and the high Ta content of the surface coating easily forms a dense acid-resistant barrier to block electrolyte erosion.

[0109] In this embodiment, the coating liquid is coated on the surface of the titanium substrate, the first active layer, and the second active layer by coating. Specifically, the coating can be carried out by spraying, roller coating, spin coating, etc., among which spraying is preferred.

[0110] Exemplarily, a multi-cycle coating method is used to prepare the second active layer. The iridium-tantalum molar ratio of the second coating solution includes 7:5, 7:4, 7:3 and 7:2, that is, one cycle has four coatings + calcinations, and the iridium-tantalum molar ratios of the second coating solution for the four coatings are 7:5, 7:4, 7:3 and 7:2, respectively. After the second coating solution of one cycle is coated and calcined in sequence, it is equivalent to completing one cycle of coating and calcination. It can be understood that in the actual production process, the second coating solution can be coated and calcined in a single cycle or multiple cycles according to the process requirements and parameter requirements of the production product. The number of coatings and the iridium-tantalum molar ratio in the second coating solution can also be adjusted according to actual needs.

[0111] For example, in step S100, the first coating liquid is sprayed onto the titanium substrate, followed by calcination, and the above steps are repeated until the tantalum content reaches the target requirement.

[0112] Preferably, in step S100, multiple coatings are applied, and after each coating, the coating is calcined at 450-550°C for 8-12 minutes. For example, the first coating solution is applied to the titanium substrate by spraying, and after each spraying, the coating is calcined at 500°C for 10 minutes. This step (spraying + calcining) is repeated 3-5 times until the tantalum content reaches 3-5 g / m 2 Then proceed to the next process of spraying the second activation layer.

[0113] Preferably, in step S200, multiple coatings are applied, and after each coating, the coating is calcined at 450-550°C for 8-12 minutes, and the last coating is calcined for 1.5-2.5 hours. For example, the second coating solution is applied on the first active layer by spraying, and the corresponding coating solution is calcined at 500°C for 10 minutes each time. This cycle is repeated multiple times, and the last coating is calcined for 2 hours to make the metal iridium content reach 25-27 g / m 2 , and obtain the second active layer.

[0114] Preferably, before step S100, the titanium substrate is also pretreated.

[0115] The titanium plate surface is in direct contact with air, resulting in a certain amount of oxide film on the surface. Furthermore, during processing or storage, some oil, organic matter, and other impurities may remain, which can affect the wettability and adhesion of the coating. Pre-treating the titanium plate provides a stable foundation for uniform coating, strong adhesion, and good bonding of the subsequent coating.

[0116] In order to eliminate the internal stress existing in the titanium plate correction process and prevent the composite layer coating from cracking due to the release of internal stress during calcination, the titanium plate needs to be pretreated by spraying, acid treatment, baking and other pretreatment steps. The above pretreatment can increase the activation energy of the titanium plate surface and enhance the adsorption force between the composite layer and the titanium plate.

[0117] Specifically, the titanium plate pretreatment steps are as follows:

[0118] The titanium plate is sequentially subjected to sandblasting treatment and acid treatment, and then cleaned; the titanium plate is baked to obtain a titanium matrix, the baking time is 1.5 to 2 hours, and the baking temperature is 150 to 200°C.

[0119] Sandblasting can strip off the dense TiO2 passivation film naturally formed on the surface of the titanium plate, exposing fresh titanium metal and improving surface activity; and, by impacting the surface of the titanium plate with high-speed sand particles, a uniform microscopic concave-convex structure is formed, increasing the specific surface area, providing a mechanical anchor point for subsequent coatings and improving adhesion.

[0120] Preferably, the surface roughness of the titanium plate after sandblasting is 11 to 13 μm; if the roughness is too low, the mechanical bite between the coating and the substrate is insufficient, which can easily lead to interface peeling; and if the roughness is too high, it can easily cause local stress concentration in the coating and produce microcracks.

[0121] In an optional embodiment, the acid treatment includes the following steps: immersing the sandblasted titanium plate in a hydrochloric acid solution with a concentration of 10±3%, and then immersing the titanium plate in an oxalic acid solution with a concentration of 10±3% for etching for 0.5 to 2 hours, and the oxalic acid solution is in a boiling state to remove impurities on the surface of the titanium plate.

[0122] Hydrochloric acid dissolves residual metal dust, grease, and some oxides after sandblasting, providing a clean surface for deep oxalic acid etching and preventing impurities from interfering with etching uniformity. Oxalic acid reacts violently with titanium at high temperatures to form a soluble titanium oxalate complex, which creates a porous structure on the titanium surface and helps improve coating adhesion.

[0123] Cleaning titanium plates can remove acid residues through ultrasonic cleaning to prevent residual acid ions from causing corrosion or pores in subsequent high-temperature processes.

[0124] Baking and cleaning the titanium plate can, on the one hand, remove moisture and solvents adsorbed on the surface of the titanium plate, avoiding bubbles generated by the coating liquid due to water volatilization during coating; on the other hand, at 150-200°C, the residual stress inside the titanium plate is partially released, preventing the coating from cracking due to the release of internal stress during the calcination process; at the same time, the baked titanium plate can increase its surface activation energy and enhance the adsorption force of the coating liquid during the brushing process.

[0125] In order to improve the corrosion resistance of the composite layer to the electrolyte and increase the service life of the entire anode, in an optional embodiment, a third coating liquid is sprayed onto the surface of the second active layer and calcined to form a protective layer, and the third coating liquid includes ruthenium salt.

[0126] After calcination, the third coating solution forms a structure of RuO on the surface of the second active layer (Ta2O5-CeO2-IrO2). y The protective layer of RuO y It has strong corrosion resistance in strong acid electrolyte (such as copper sulfate solution), which can prevent the electrolyte from directly corroding the second active layer and prolong the life of the titanium anode. y It is a metal oxide semiconductor with certain conductivity and catalytic activity, which effectively reduces the additional resistance introduced by the protective layer.

[0127] Specifically, ruthenium trichloride and butyl titanate are dissolved in an n-butanol solution, hydrochloric acid is added, and the mixture is mixed to produce a third coating solution. The butyl titanate serves the same purpose as in the first coating solution, so its description is omitted here. n-Butanol, a high-boiling-point organic solvent, slows the drying speed of the coating solution, improves spray leveling, and prevents droplet accumulation. Its weak polarity also helps evenly disperse the ruthenium salt and butyl titanate.

[0128] In the third coating solution, if the volume ratio of n-butanol solution to hydrochloric acid is too low, the pH may be too high, leading to uncontrolled hydrolysis of butyl titanate. If the ratio is too high, it may cause gelation of the coating solution. Preferably, the volume ratio of n-butanol solution to hydrochloric acid is (8-12):(0.9-1.1). Preferably, the mass fraction of hydrochloric acid is 37%.

[0129] Preferably, the mass ratio of ruthenium trichloride, butyl titanate, and n-butanol solution is (3-4):(10-11):(44-53). Too little ruthenium salt can lead to a thin protective layer and insufficient protection; too much ruthenium salt can easily cause internal stress cracks due to excessively thick coating.

[0130] In a third aspect, the present application also provides an electrolytic copper foil, comprising the above-mentioned titanium anode or a titanium anode prepared by the above-mentioned titanium anode preparation method.

[0131] Fourthly, the present application further provides for the use of the electrolytic copper foil in fields such as copper-clad laminates, printed circuit boards, or lithium-ion batteries. It will be appreciated that the electrolytic copper foil has the beneficial effects of the titanium anode of the above-described embodiment or the titanium anode produced by the above-described titanium anode preparation method, and therefore will not be described in detail here.

[0132] According to the above implementation mode, the present application is explained in detail in combination with the following examples and comparative examples.

[0133] Example:

[0134] 1. Pretreatment of titanium plate:

[0135] The surface of the titanium plate is sandblasted with steel grit to achieve a surface Ra of 11 to 13 μm. The sandblasted titanium plate is completely immersed in a hydrochloric acid solution for 24 hours to remove rust and other impurity ions from the anode surface material. The immersion is carried out using a 10±3% hydrochloric acid solution. The titanium plate soaked in hydrochloric acid needs to be completely cleaned with deionized pure water. Then, 10% boiling oxalic acid is used for etching for 2 hours to remove oil and impurities on the surface. The titanium plate after oxalic acid pickling is ultrasonically cleaned for 1 hour, then rinsed twice with pure water and dried for use. The dried titanium plate is placed in an oven for 2 hours at 200°C to release the internal stress in the titanium plate.

[0136] 2. Configure the coating liquid corresponding to the composite layer:

[0137] Among them, for the sake of convenience, additive 1 is butyl titanate, additive 2 is a mixed additive of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol, and the volume ratio of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol is 1:1:1.

[0138] Configuration of the first coating liquid:

[0139] 2 mL of tantalum pentachloride n-butanol solution was measured and dissolved in 18 mL of n-butanol, and 2 mL of 37% hydrochloric acid was added, and then butyl titanate was added. The molar ratio of butyl titanate to tantalum pentachloride n-butanol solution was 7:3 to obtain a first coating solution. The concentration of tantalum pentachloride n-butanol solution in the first coating solution was 0.07 mol / L.

[0140] Configuration of the second coating liquid:

[0141] Second coating solution a: dissolve chloroiridic acid solution in isopropyl alcohol to obtain solution A, so that the concentration of chloroiridic acid in solution A is 0.175 mol / L; dissolve tantalum pentachloride n-butanol solution in n-butanol to obtain solution B, so that the concentration of tantalum pentachloride n-butanol solution in solution B is 0.125 mol / L; mix solution A and solution B in a volume ratio of 1:1 to form a mixed solution; add hydrochloric acid (mass fraction of 37%) to the solution; the volume ratio of the mixed solution to hydrochloric acid is 20:1; add additive 2 thereto; the mass ratio of chloroiridic acid to additive 2 in the solution is 6:1; and simultaneously add cerium chloride (CeCl3·6H2O) to make the concentration of cerium chloride in the mixed solution 0.015 mol / L. The solution is fully stirred and mixed for use; the solution is prepared and used immediately, and the storage time does not exceed 6 hours.

[0142] Second coating solution b: dissolving chloroiridic acid solution in isopropyl alcohol to obtain solution A, and making the concentration of chloroiridic acid in solution A 0.175 mol / L; dissolving tantalum pentachloride n-butanol solution in n-butanol to obtain solution B, and making the concentration of tantalum pentachloride n-butanol solution in solution B 0.100 mol / L; mixing solution A and solution B in a volume ratio of 1:1 to form a mixed solution; adding hydrochloric acid (mass fraction of 37%) to the solution, and the volume ratio of the mixed solution to hydrochloric acid is 20:1; adding additive 2 thereto, and the mass ratio of chloroiridic acid to additive 2 in the solution is 6:1; adding cerium chloride (CeCl3·6H2O) at the same time, and making the concentration of cerium chloride in the mixed solution 0.015 mol / L; stirring and mixing the solution thoroughly for use; the solution is prepared and used immediately, and the storage time does not exceed 6 hours.

[0143] Second coating solution c: dissolve chloroiridic acid solution in isopropyl alcohol to obtain solution A, and make the chloroiridic acid concentration in solution A 0.175 mol / L; dissolve tantalum pentachloride n-butanol solution in n-butanol to obtain solution B, and make the concentration of tantalum pentachloride n-butanol solution 0.075 mol / L; mix solution A and solution B in a volume ratio of 1:1 to form a mixed solution; add hydrochloric acid (mass fraction 37%) to the solution, and the volume ratio of the mixed solution to hydrochloric acid is 20:1; add additive 2 thereto, and the mass ratio of chloroiridic acid to additive 2 in the solution is 6:1; add cerium chloride (CeCl3·6H2O) to make the concentration of cerium chloride in the mixed solution 0.015 mol / L; stir and mix the solution thoroughly for use; the solution should be used immediately after preparation and should be allowed to stand for no more than 6 hours.

[0144] Second coating solution d: Dissolve chloroiridic acid solution in isopropyl alcohol to obtain solution A, and adjust the concentration of chloroiridic acid in solution A to 0.175 mol / L. Dissolve tantalum pentachloride n-butanol solution in n-butanol to obtain solution B, and adjust the concentration of tantalum pentachloride n-butanol solution to 0.05 mol / L. Mix solution A and solution B in a volume ratio of 1:1 to form a mixed solution. Add hydrochloric acid (mass fraction of 37%) to the solution, and the volume ratio of the mixed solution to hydrochloric acid is 20:1. Additive 2 is added thereto, and the mass ratio of chloroiridic acid to additive 2 in the solution is 6:1. Cerium chloride (CeCl3·6H2O) is also added to adjust the concentration of cerium chloride in the mixed solution to 0.015 mol / L. The solution is thoroughly stirred and mixed for use. The solution is prepared and used immediately, and the storage time does not exceed 6 hours.

[0145] The difference between the second coating liquid a, the second coating liquid b, the second coating liquid c and the second coating liquid d lies in the different concentrations of the tantalum pentachloride n-butanol solution, so as to prepare the second coating liquids with different iridium-tantalum molar ratios.

[0146] Configuration of the third coating liquid:

[0147] 3.5 g of ruthenium trichloride and 10.6 g of butyl titanate were weighed and dissolved in 60 mL of n-butanol. At the same time, 37% hydrochloric acid was added with a volume ratio of n-butanol to hydrochloric acid of 10:1 to obtain a third coating solution.

[0148] 3. Preparation of coating:

[0149] The first coating liquid is sprayed on the pre-treated titanium plate (the titanium plate is baked and kept warm at this time), calcined at 500℃ for 10 minutes, and this step is repeated 3 to 5 times until the tantalum metal content reaches 3 to 5 g / m 2 Until the first active layer is obtained.

[0150] The second coating liquid a, second coating liquid b, second coating liquid c and second coating liquid d are sprayed on the titanium substrate containing the first active layer in sequence, and the corresponding coating liquid is calcined at 500℃ for 10 minutes each time. This cycle is repeated several times, and the last time is calcined for 2 hours to make the metal iridium content reach 25-27g / m 2 , and obtain the second active layer.

[0151] Spray the third coating liquid on the titanium plate containing the second active layer for 2 to 3 times until the ruthenium content reaches 2 to 3 g / m 2 Until a protective layer is obtained.

[0152] Finally, after cooling and drying, the structural expression is Ti / TiO x -Ta2O5 / Ta2O5-CeO2-IrO2 / RuO2 titanium anode.

[0153] The following comparative examples are compared with the examples. The pretreatment of the titanium plate, the preparation of the coating solution corresponding to the composite layer, and the preparation of the coating process are the same. The specific differences are as follows:

[0154] Comparative Example 1

[0155] The difference between this comparative example and Example 1 is that the coating solution corresponding to the composite layer does not include the third coating solution, the first coating solution contains additive 1, and the second coating solution contains additive 2. The prepared titanium anode does not have a protective layer. The structure of the prepared titanium anode is Ti / TiO x -Ta2O5 / Ta2O5-CeO2-IrO2.

[0156] Comparative Example 2

[0157] The difference between this comparative example and Example 1 is that the coating solution corresponding to the composite layer does not include the third coating solution, the first coating solution contains additive 1, and the second coating solution does not contain additive 2. The titanium anode structure prepared is Ti / TiO x -Ta2O5 / Ta2O5-CeO2-IrO2.

[0158] Comparative Example 3

[0159] The difference between this comparative example and Example 1 is that the coating solution for configuring the composite layer does not include the third coating solution, the first coating solution does not contain additive 1, and the second coating solution contains additive 2. The titanium anode structure prepared is Ti / Ta2O5 / Ta2O5-CeO2-IrO2.

[0160] Comparative Example 4

[0161] The difference between this comparative example and Example 1 is that the coating solution for configuring the composite layer does not include the third coating solution, the first coating solution does not contain additive 1, and the second coating solution does not contain additive 2. The structure of the prepared titanium anode is Ti / Ta2O5 / Ta2O5-CeO2-IrO2.

[0162] Performance testing:

[0163] 1. SEM (Scanning Electron Microscope): The titanium anodes in the embodiment and comparative examples 1 to 4 were subjected to SEM testing.

[0164] 2. Oxygen evolution potential test:

[0165] Test conditions: With a platinum electrode as the counter electrode, the titanium anodes in Examples and Comparative Examples 1 to 4 as the working electrode, and an Ag / AgCl electrode as the reference electrode, the samples were scanned at a scan rate of 10 mV / s in a 1 mol / L H2SO4 aqueous solution, and the oxygen evolution current density was recorded when the oxygen evolution current density was 10 A / dm 2 The oxygen evolution potential at .

[0166] 3. Electrode activity test:

[0167] Test conditions: Electrochemical cyclic voltammetry was used with a bias scan range of 0.16 V to 1.16 V in a 1 mol / L H2SO4 aqueous solution at a scan rate of 0.05 V / s.

[0168] 4. Strengthen life test:

[0169] Test conditions: In order to verify the durability of the titanium anode, the titanium anodes of the above embodiment and the comparative example were subjected to an enhanced life test. The enhanced life test was carried out in a 1 mol / L sulfuric acid electrolyte (electrolyte temperature was 50±2°C) with a current density of 30000 A / m 2 , the inter-electrode distance is 1.5cm.

[0170] refer to Figures 1 to 5 It can be seen that the electrode in Example 1 is relatively flat and has no cracks; the electrode in Comparative Example 1 is relatively flat, has more iridium oxide crystal clusters, and has no cracks; the electrode in Comparative Example 2 is relatively flat and has no cracks; the electrode in Comparative Example 3 is relatively flat, has more iridium oxide crystal clusters, and has cracks; the electrode in Comparative Example 4 is relatively flat, has fewer iridium oxide crystal clusters, and has larger cracks.

[0171] like Figure 6 As shown, compared with the electrodes in comparative examples 1 to 4, the oxygen potential in Example 1 is closer to the left, indicating that the performance of the electrode in Example 1 is better than that of the electrodes in comparative examples 1 to 4.

[0172] like Figure 7 As shown, compared with the CV areas of the electrodes in Comparative Examples 1 to 4, the CV area of the electrode in Example 1 is larger, indicating that the active area of the electrode is large and the catalytic property is good.

[0173] like Figure 8 As shown, compared with the electrodes in Comparative Examples 1 to 4, the electrode in Example 1 has a longer life and excellent electrode performance.

[0174] Therefore, the titanium anode prepared in the embodiment of the present application has strong bonding strength, few cracks, small iridium oxide grains, high electrocatalytic activity, good uniformity, and the catalytic layer is not easily corroded, which makes the titanium anode have a longer service life.

[0175] In addition, an embodiment of the present application further provides an electrolytic copper foil, which includes the above-mentioned titanium anode or a titanium anode prepared by the above-mentioned titanium anode preparation method.

[0176] The present application also provides an application of electrolytic copper foil in electronic devices. The electrolytic copper foil is used in the fields of copper clad laminates, printed circuit boards and lithium-ion batteries.

[0177] In the above embodiments, the description of each embodiment has its own emphasis. For parts not described in detail in a particular embodiment, please refer to the relevant description of other embodiments. The technical features of the above embodiments can be combined in any way. To keep the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0178] Those skilled in the art will readily appreciate other embodiments of the present application after considering the specification and practicing the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of the present application that follow the general principles of the present application and include common knowledge or customary techniques in the art not disclosed herein. The description and examples are to be considered as exemplary only, and the true scope and spirit of the present application are indicated by the following claims.

[0179] It should be understood that the present application is not limited to the exact structure described above and shown in the drawings, and that various modifications and changes may be made without departing from the scope thereof. The scope of the present application is limited only by the appended claims.

Claims

1. A titanium anode, characterized in that: include: Titanium matrix; A composite layer, the composite layer comprising a first active layer and a second active layer sequentially disposed on the titanium substrate, wherein the first active layer is disposed on a surface of the titanium substrate; The first active layer includes titanium oxide and tantalum oxide, and the second active layer includes tantalum oxide, iridium oxide and cerium oxide.

2. The titanium anode according to claim 1, characterized in that The content of tantalum in the first active layer is 3-5 g / m 2 The molar ratio of titanium to tantalum in the first active layer is 7:2-4.

3. The titanium anode according to claim 2, characterized in that The iridium content in the second active layer is 25-27 g / m 2 The molar ratio of iridium to tantalum in the second active layer is 6:5 to 4:1, and the molar ratio of iridium to cerium in the second active layer is 21:5 to 22:

3.

4. The titanium anode according to claim 1, characterized in that The second active layer is provided with a protective layer on the side away from the titanium substrate, the protective layer comprises ruthenium oxide, and the content of ruthenium in the protective layer is 2-3 g / m 2 .

5. A method for preparing a titanium anode, for preparing the titanium anode according to any one of claims 1 to 4, characterized in that: The following steps are involved: Applying a first coating liquid to the surface of the titanium substrate and calcining to form the first active layer, wherein the first coating liquid includes tantalum salt and butyl titanate; A second coating liquid is applied to the surface of the first active layer and calcined to form the second active layer. The second coating liquid includes tantalum salt, cerium salt, chloroiridic acid and mixed additives. The mixed additives include N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol.

6. The method for preparing a titanium anode according to claim 5, characterized in that: The first coating liquid is prepared by adding hydrochloric acid and butyl titanate to a tantalum pentachloride n-butanol solution; The concentration of the tantalum pentachloride n-butanol solution is 0.05 to 0.09 mol / L; The molar ratio of the butyl titanate to the tantalum pentachloride n-butanol solution is 7:2-4.

7. The method for preparing a titanium anode according to claim 5, characterized in that: The preparation of the second coating solution comprises the following steps: Dissolve the chloroiridic acid solution in the isopropanol solution to obtain solution A; Dissolve the tantalum pentachloride n-butanol solution in the n-butanol solution to obtain solution B; mixing the solution A and the solution B to obtain a mixed solution, adding hydrochloric acid, N,N-dimethylformamide, N,N-dimethylacetamide, polyvinyl alcohol and cerium chloride to the mixed solution, and mixing to obtain the second coating solution; In the solution A, the concentration of the chloroiridic acid solution is 0.15 to 0.20 mol / L; in the solution B, the concentration of the tantalum pentachloride n-butanol solution is 0.05 to 0.125 mol / L; In the mixed solution, the volume ratio of solution A to solution B is 1:1; the volume ratio of the mixed solution to the hydrochloric acid is 18-22:0.8-1.2, wherein the mass fraction of hydrochloric acid is 37%; The mass ratio of the total mass of the N,N-dimethylformamide, the N,N-dimethylacetamide and the polyvinyl alcohol to the chloroiridic acid is 0.8-1.2:4-8; The volume ratio of N,N-dimethylformamide, N,N-dimethylacetamide and polyvinyl alcohol is 0.8-1.2:0.9-1.1:1; The concentration of the cerium chloride in the second coating solution is 0.013 to 0.017 mol / L.

8. The method for preparing a titanium anode according to claim 7, characterized in that: During the preparation of the second active layer, the second coating liquid is applied to the surface of the first active layer multiple times and calcined, and the molar ratio of iridium to tantalum in the second coating liquid applied each time decreases successively.

9. The method for preparing a titanium anode according to claim 5, wherein: Also includes: A third coating liquid is applied to the surface of the second active layer and calcined to form the protective layer, wherein the third coating liquid includes ruthenium salt.

10. The method for preparing a titanium anode according to claim 9, characterized in that: The preparation of the third coating solution comprises the following steps: Dissolving ruthenium trichloride and butyl titanate in n-butanol solution, adding hydrochloric acid, and mixing to obtain the third coating solution; The volume ratio of n-butanol solution to hydrochloric acid is 8-12:0.9-1.1, wherein the mass fraction of the hydrochloric acid is 37%; The mass ratio of the ruthenium trichloride, the butyl titanate and the n-butanol solution is 3-4:10-11:44-53.

11. The method for preparing a titanium anode according to claim 5, characterized in that: Before coating the titanium substrate with the first coating liquid, pretreating the titanium substrate comprises the following steps: The titanium plate is sequentially subjected to sandblasting and acid treatment, and then the titanium plate is cleaned and baked to obtain the titanium substrate; The surface roughness of the titanium plate after the sandblasting treatment is 11 to 13 μm; The acid treatment comprises the following steps: immersing the titanium plate after sandblasting in a hydrochloric acid solution with a concentration of 10±3%, and then immersing the titanium plate in an oxalic acid solution with a concentration of 10±3% for etching for 0.5 to 2 hours, with the oxalic acid solution being in a boiling state, to remove impurities on the surface of the titanium plate; The baking time of the titanium plate is 1.5 to 2 hours, and the baking temperature is 150 to 200°C.

12. An electrolytic copper foil, characterized in that: The electrolytic copper foil comprises: The titanium anode according to any one of claims 1 to 4; Or, a titanium anode prepared by the titanium anode preparation method according to any one of claims 5 to 11.

13. Use of the electrolytic copper foil according to claim 12 in electronic devices, characterized in that: The electrolytic copper foil is used in the fields of copper clad laminates, printed circuit boards and lithium ion batteries.

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