Preparation method of high-stability titanium electrode
By introducing cysteine hydrochloride as a reducing agent into the coated titanium electrode, the problems of easy dissolution and cracking of the coated titanium electrode in the electrolyte are solved, achieving higher stability and longer service life.
Patent Information
- Application Number
- CN202511402849.6
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-09-28
- Publication Date
- 2025-12-26
AI Technical Summary
Traditional coated titanium electrodes are prone to dissolution and cracking in electrolytes, affecting conductivity and stability, leading to a decrease in copper foil quality and yield.
Cysteine hydrochloride was used as a reducing agent to participate in the reduction reaction of iridium and tantalum, promoting the uniform precipitation of metal oxides and enhancing the adhesion between the coating and the substrate through hydroxyl functional groups, thus preparing a highly stable coated titanium electrode.
It improves the density and uniformity of the coating, enhances the adhesion between the coating and the substrate, and extends the service life of the coated titanium electrode.
Smart Images
Figure CN121204651A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of titanium electrode preparation technology by thermal decomposition, and in particular to a method for preparing a highly stable titanium electrode. Background Technology
[0002] With the rapid development of downstream sectors such as new energy vehicles and consumer electronics, the demand for lithium-ion battery copper foil continues to rise across various industries. For example, the increasing sales of new energy vehicles year by year have led to a surge in demand for lithium-ion battery copper foil, a key material for their power batteries, which in turn has driven the synchronous development of the copper foil anode industry. Currently, the anodes used in copper foil manufacturing are mainly coated titanium electrodes. Coated titanium electrodes, also known as dimensionally stable anodes (DSA anodes), are a new type of high-efficiency electrode material developed in the late 1960s. Compared with traditional graphite electrodes and lead-based electrodes, coated titanium electrodes have advantages such as stable anode dimensions, low operating voltage, long service life, strong corrosion resistance, light weight, and the ability to increase current density. Therefore, coated titanium electrodes are widely used in various industrial fields. Titanium electrodes consist of a titanium substrate and a surface-active coating. The titanium substrate acts as a framework and provides conductivity, while the active coating participates in the electrochemical reaction. However, the durability of traditional anode coatings has always been a major problem. The active components on the coating are exposed to the electrolyte for a long time, which can easily lead to dissolution, cracking, and other problems, affecting the conductivity and stability of the anode, thereby affecting the quality and yield of copper foil. Summary of the Invention
[0003] In order to solve the above problems, the present invention provides a method for preparing coated titanium electrodes with better stability and longer lifespan.
[0004] To achieve the above objectives, the technical solution of the present invention is as follows:
[0005] A method for preparing a highly stable titanium electrode, the method comprising the following steps:
[0006] S1, Surface treatment of titanium substrate: Surface treatment includes sandblasting, pickling, and cleaning;
[0007] S2, prepare an iridium-tantalum coating solution containing cysteine hydrochloride, wherein the iridium-tantalum coating solution containing cysteine hydrochloride is composed of an iridium source compound, a tantalum source compound, an organic alcohol, a cysteine hydrochloride solution, and a cobalt source compound;
[0008] S3. The coating material from S2 is applied to the titanium substrate with surface treatment in S1 by brushing. After each application, the substrate is sintered at high temperature in a muffle furnace. After sintering, the substrate is cooled to room temperature. This process is repeated multiple times. After the last application, the substrate is kept at a certain temperature. After the substrate is kept at a certain temperature, it is removed and cooled to room temperature before testing. This completes the preparation of the coated anode.
[0009] In a preferred embodiment of the present invention, the sand type used for sandblasting in S1 is either brown fused alumina or white fused alumina, the concentration of oxalic acid used for pickling is 7%~15%, the pickling temperature is 90℃~100℃, and the pickling time is controlled at 1h~2h.
[0010] In a preferred embodiment of the present invention, in step S2, the iridium source compound is H2IrCl6, the tantalum source compound is tantalum ethoxide, the cobalt source compound is cobalt chloride, and the organic alcohol is one or more of n-butanol, isopropanol, and ethanol.
[0011] In a preferred embodiment of the present invention, the cysteine hydrochloride solution is prepared by dissolving cysteine hydrochloride in an organic alcohol solution, wherein the organic alcohol is ethanol with a concentration of 0.002~0.006 g / ml.
[0012] In a preferred embodiment of the present invention, the content of the iridium source compound is 18~22 g / m³. 2 .
[0013] In a preferred embodiment of the present invention, the mass ratio of tantalum source compound to iridium source compound is 0.8~1.2:1.
[0014] In a preferred embodiment of the present invention, the mass ratio of cysteine hydrochloride to iridium source compound is 0.01 to 0.06:1.
[0015] In a preferred embodiment of the present invention, the mass ratio of the cobalt source compound to the iridium source compound is 0.02 to 0.06:1.
[0016] In a preferred embodiment of the present invention, in step S3, the calcination temperature is 450℃~550℃, the calcination time is 10min~20min, and the holding time is 1h~2h.
[0017] A highly stable titanium electrode, wherein the coating of the highly stable titanium electrode comprises cysteine hydrochloride.
[0018] The beneficial effects of this invention are:
[0019] This invention provides a stable coated titanium electrode by introducing cysteine hydrochloride into the coating. During the preparation of the active coating, the cysteine hydrochloride acts as a reducing agent in the reduction reaction of iridium and tantalum, promoting uniform precipitation of metal oxides, avoiding localized over-oxidation and agglomeration, and improving the density and uniformity of the coating. Simultaneously, the hydroxyl functional groups on the cysteine hydrochloride form bonds with the oxides on the titanium substrate surface, increasing the adhesion between the coating and the substrate, reducing coating peeling during electrolysis, and thus extending the anode life. Therefore, compared to traditional coated titanium electrodes, the coated titanium electrode prepared by the method proposed in this invention exhibits superior stability. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 Enhanced lifetime diagrams of coated titanium anodes with different amounts of cysteine hydrochloride introduced. Detailed Implementation
[0022] To make the technical means, creative features, objectives and effects of this invention easier to understand, the invention is further described below.
[0023] The present invention provides a method for preparing a highly stable titanium electrode, comprising the following steps:
[0024] S1, Surface treatment of titanium substrate: Surface treatment includes sandblasting, pickling, and cleaning;
[0025] S2, Prepare an iridium-tantalum coating solution containing cysteine hydrochloride, wherein the iridium-tantalum coating solution containing cysteine hydrochloride is composed of an iridium source compound, a tantalum source compound, an organic alcohol, a cysteine hydrochloride solution, and a cobalt source compound;
[0026] S3 involves applying the coating from S2 onto the titanium substrate with the surface treated in S1 by brushing. After each application, the substrate is sintered at high temperature in a muffle furnace. After sintering, the substrate is cooled to room temperature. This process is repeated multiple times. After the final application, the substrate is kept at a certain temperature. After the final application, the substrate is removed and allowed to cool to room temperature before testing. This completes the preparation of the coated anode.
[0027] In S1, the sand type used for sandblasting is either brown fused alumina or white fused alumina; pickling involves immersing the sandblasted titanium substrate in a solution with an oxalic acid concentration of 7% to 15%, at a solution temperature of 90℃ to 100℃, and controlling the pickling time to be 1h to 2h; the pickled titanium substrate is then cleaned with deionized water.
[0028] In S2, the iridium source compound is H2IrCl6, the tantalum source compound is tantalum ethoxide, the cobalt source compound is cobalt chloride, and the organic alcohol is one or more of n-butanol, isopropanol, and ethanol; the cysteine hydrochloride solution is prepared by dissolving cysteine hydrochloride in an organic alcohol solution, wherein the organic alcohol is ethanol with a concentration of 0.002~0.006 g / ml; and the content of the iridium source compound is 18~22 g / ml. 2 The mass ratio of tantalum source compound to iridium source compound is 0.8~1.2:1; the mass ratio of cysteine hydrochloride to iridium source compound is 0.01~0.06:1; and the mass ratio of cobalt source compound to iridium source compound is 0.02~0.06:1.
[0029] An iridium-tantalum coating solution is obtained by taking an iridium source compound with an iridium content of 18~22 g / m2, adding a tantalum source compound with a mass ratio of 0.8~1.4:1 to the iridium source compound, stirring the two evenly, adding a cobalt source compound, mixing evenly, and then adding an organic alcohol and cysteine hydrochloride solution.
[0030] In S3, the calcination temperature is 450℃~550℃, the calcination time is 10min~20min, and the holding time is 1h~2h.
[0031] In the following embodiments, due to the certain loss of coating material during the preparation of the active coating, the theoretical value of the precious metal content is not exactly the same as the actual value. This is a normal phenomenon. Those skilled in the art can adjust the amount of raw materials added to the coating liquid according to conventional technical means to obtain an active coating with a precious metal content close to the theoretical value.
[0032] The inventors will further explain and illustrate the present invention through the following specific embodiments:
[0033] Example 1
[0034] (1) Surface treatment of titanium substrate:
[0035] The abrasive used for sandblasting is brown corundum. After sandblasting, the titanium substrate is pickled with oxalic acid. The titanium substrate is placed in an 8% oxalic acid solution, and the pickling temperature is controlled at 90℃ for 1 hour and 10 minutes. After pickling, it is rinsed with deionized water and then set aside for use.
[0036] (2) Prepare an iridium-tantalum coating solution containing cysteine hydrochloride:
[0037] Prepare a 0.002 g / ml cysteine hydrochloride ethanol solution. Take 0.614 g of chloroiridic acid (iridium content 22 g / m2) and 0.491 g of tantalum ethoxide (the mass ratio of chloroiridic acid to tantalum ethoxide is 0.8:1), mix well, add 7.281 ml of n-butanol solution, stir well, then add 0.612 g of cobalt chloride (the mass ratio of cobalt chloride to chloroiridic acid is 0.06:1) and 3.069 ml of cysteine hydrochloride ethanol solution (the mass ratio of cysteine hydrochloride to chloroiridic acid is 0.01:1), mix well and set aside.
[0038] (3) Apply the prepared iridium-tantalum coating solution containing cysteine hydrochloride to the treated titanium substrate by brushing. After brushing, dry in an oven at 100°C and calcine in a muffle furnace at 450°C for 15 min, and repeat several times. After the last brushing, keep warm for 2 h.
[0039] Example 2
[0040] Surface treatment of titanium substrate:
[0041] The abrasive used for sandblasting is white corundum. After sandblasting, the titanium substrate is pickled with oxalic acid. The titanium substrate is placed in a 12% oxalic acid solution, and the pickling temperature is controlled at 95℃ for 1 hour and 30 minutes. After pickling, it is rinsed with deionized water and then set aside for use.
[0042] (2) Prepare an iridium-tantalum coating solution containing cysteine hydrochloride:
[0043] Prepare a 0.004 g / ml cysteine hydrochloride ethanol solution. Take 0.558 g of chloroiridic acid (iridium content 20 g / m2) and 0.558 g of tantalum ethoxide (chloroiridic acid to tantalum ethoxide mass ratio 1:1), mix well, then add 6.367 ml of a mixed solution of n-butanol and isopropanol, stir well, then add 0.371 g of cobalt chloride (cobalt chloride to chloroiridic acid mass ratio 0.04:1) and 4.185 ml of cysteine hydrochloride ethanol solution (cysteine hydrochloride to chloroiridic acid mass ratio 0.03:1), mix well and set aside.
[0044] (3) Apply the prepared iridium-tantalum coating solution containing cysteine hydrochloride to the treated titanium substrate by brushing. After brushing, dry in an oven at 100°C and calcine in a muffle furnace at 500°C for 13 min, and repeat several times. After the last brushing, keep warm for 1 h 30 min.
[0045] Example 3
[0046] (1) Surface treatment of titanium substrate:
[0047] The abrasive used for sandblasting is brown corundum. After sandblasting, the titanium substrate is pickled with oxalic acid. The titanium substrate is placed in a 15% oxalic acid solution, and the pickling temperature is controlled at 100℃ for 2 hours. After pickling, it is rinsed with deionized water and then set aside for use.
[0048] (2) Prepare an iridium-tantalum coating solution containing cysteine hydrochloride:
[0049] Prepare a 0.006 g / ml cysteine hydrochloride ethanol solution. Take 0.502 g of chloroiridic acid (iridium content 18 g / m2) and 0.603 g of tantalum ethoxide (the mass ratio of chloroiridic acid to tantalum ethoxide is 1:1.2), mix well, add 6.554 ml of isopropanol solution, stir well, then add 0.167 ml of cobalt chloride (the mass ratio of cobalt chloride to chloroiridic acid is 0.02:1) and 4.185 ml of cysteine hydrochloride ethanol solution (the mass ratio of cysteine hydrochloride to chloroiridic acid is 0.05:1), mix well and set aside.
[0050] (3) Apply the prepared iridium-tantalum coating solution containing cysteine hydrochloride to the treated titanium substrate by brushing. After brushing, dry in an oven at 100°C and calcine in a muffle furnace at 550°C for 10 min, and repeat several times. After the last brushing, keep warm for 1 h.
[0051] Comparative Example 1
[0052] (1) Surface treatment of titanium substrate:
[0053] The abrasive used for sandblasting is brown corundum. After sandblasting, the titanium substrate is pickled with oxalic acid. The titanium substrate is placed in an 8% oxalic acid solution, and the pickling temperature is controlled at 90℃ for 1 hour and 10 minutes. After pickling, it is rinsed with deionized water and then set aside for use.
[0054] (2) Prepare an iridium-tantalum coating solution containing cysteine hydrochloride:
[0055] Take 0.614g of chloroiridic acid (iridium content is 22g / m2) and 0.491g of tantalum ethoxide (the mass ratio of chloroiridic acid to tantalum ethoxide is 0.8:1), mix them evenly, add 10.35ml of n-butanol solution, stir evenly, add 0.612ml of cobalt chloride (the mass ratio of cobalt chloride to chloroiridic acid is 0.06:1), mix evenly, and then add reducing agent for later use.
[0056] (3) Apply the prepared coating to the treated titanium substrate by brushing. After brushing, dry in an oven at 100°C and calcine in a muffle furnace at 450°C for 15 minutes. Repeat this process several times. After the last brushing, keep warm for 2 hours.
[0057] To determine the enhanced lifetime of coated titanium anodes with different amounts of cysteine hydrochloride introduction, at 2 WA / m 2 The enhanced lifetime test was conducted in 1 mol / L H2SO4 at a constant current density, and 25 mg of organic additives were added to the solution daily.
[0058] Experimental results: From Figure 1 As can be seen, the strengthening lifetime first increases and then decreases with the increase of the amount of cysteine hydrochloride introduced. The strengthening lifetime of the coated titanium anode obtained in Example 1 is 21 days; the strengthening lifetime of the coated titanium anode obtained in Example 2 is 19 days; and the strengthening lifetime of the coated titanium anode obtained in Example 3 is 17 days. Excessive cysteine hydrochloride may not decompose completely during high-temperature sintering, leaving residual impurities such as carbon and sulfur (e.g., generating H2S or sulfides), leading to pores, cracks, or amorphous regions in the coating, reducing density, and thus affecting the strengthening lifetime. However, compared with Comparative Example 1 which does not contain cysteine hydrochloride, the strengthening lifetime of the coated titanium anodes obtained in Examples 1, 2, and 3 is generally increased. Cysteine hydrochloride participates in the reduction reaction of metal ions (such as iridium and tantalum) as a reducing agent, promoting the uniform deposition of metal oxides. Furthermore, under strongly acidic or high current density conditions, noble metals (such as iridium) in the coating may selectively dissolve. Cysteine hydrochloride, due to its reducing properties, may be preferentially oxidized to form a protective intermediate film, reducing the loss of precious metals, maintaining the electrocatalytic activity of the coating, and extending its service life. Therefore, combining... Figure 1 The enhanced life test results show that introducing an appropriate amount of cysteine hydrochloride can produce a coated titanium electrode with good stability.
[0059] Based on the above embodiments, the present invention also provides a high-stability titanium electrode, the coating of which contains cysteine hydrochloride. By introducing cysteine hydrochloride into the coating, cysteine hydrochloride can participate in the reduction reaction of iridium and tantalum as a reducing agent in the coating, promote the uniform precipitation of metal oxides, avoid local over-oxidation and agglomeration, and improve the density and uniformity of the coating. At the same time, the hydroxyl functional groups on the cysteine hydrochloride form bonds with the oxides on the surface of the titanium substrate, increase the bonding force between the coating and the substrate, reduce coating peeling during the electrolysis process, and thus extend the life of the anode.
[0060] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the present invention as claimed. The scope of protection of this invention is defined by the appended claims and their equivalents.
Claims
1. A method for preparing a highly stable titanium electrode, characterized in that, The preparation method includes the following steps: S1, Surface treatment of titanium substrate: Surface treatment includes sandblasting, pickling, and cleaning; S2, prepare an iridium-tantalum coating solution containing cysteine hydrochloride, wherein the iridium-tantalum coating solution containing cysteine hydrochloride is composed of an iridium source compound, a tantalum source compound, an organic alcohol, a cysteine hydrochloride solution, and a cobalt source compound; S3. The coating material from S2 is applied to the titanium substrate with surface treatment in S1 by brushing. After each application, the substrate is sintered at high temperature in a muffle furnace. After sintering, the substrate is cooled to room temperature. This process is repeated multiple times. After the last application, the substrate is kept at a certain temperature. After the substrate is kept at a certain temperature, it is removed and cooled to room temperature before testing. This completes the preparation of the coated anode.
2. The method for preparing a high-stability titanium electrode according to claim 1, characterized in that, The sand type used for sandblasting in S1 is either brown fused alumina or white fused alumina. The concentration of oxalic acid used for pickling is 7% to 15%, the pickling temperature is 90℃ to 100℃, and the pickling time is controlled at 1h to 2h.
3. The method for preparing a high-stability titanium electrode according to claim 1, characterized in that, In S2, the iridium source compound is H2IrCl6, the tantalum source compound is tantalum ethoxide, the cobalt source compound is cobalt chloride, and the organic alcohol is one or more of n-butanol, isopropanol, and ethanol.
4. A method for preparing a high-stability titanium electrode according to claim 1 or 3, characterized in that, The cysteine hydrochloride solution is prepared by dissolving cysteine hydrochloride in an organic alcohol solution, wherein the organic alcohol is ethanol with a concentration of 0.002~0.006 g / ml.
5. The method for preparing a high-stability titanium electrode according to claim 1, characterized in that, The content of the iridium source compound is 18~22 g / m³. 2 .
6. A method for preparing a high-stability titanium electrode according to claim 1 or 5, characterized in that, The mass ratio of tantalum source compound to iridium source compound is 0.8~1.2:
1.
7. A method for preparing a high-stability titanium electrode according to claim 1 or 5, characterized in that, The mass ratio of cysteine hydrochloride to iridium source compound is 0.01~0.06:
1.
8. A method for preparing a high-stability titanium electrode according to claim 1 or 5, characterized in that, The mass ratio of cobalt source compound to iridium source compound is 0.02~0.06:
1.
9. The method for preparing a high-stability titanium electrode according to claim 1, characterized in that, In S3, the calcination temperature is 450℃~550℃, the calcination time is 10min~20min, and the holding time is 1h~2h.
10. A high-stability titanium electrode, characterized in that, The coating of the high-stability titanium electrode contains cysteine hydrochloride.