Electrolyte for producing foam inhibition type lithium battery copper foil
The foam-suppressing electrolyte composition addresses foam accumulation issues in lithium battery copper foil production by optimizing electrolyte stability and uniform copper ion deposition, enhancing the mechanical strength and conductivity of the copper foil.
Patent Information
- Application Number
- CN202411225569.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-09-03
- Publication Date
- 2024-12-10
AI Technical Summary
The accumulation of foam in the electrolyte used in lithium battery copper foil production leads to surface spots and quality degradation, affecting the consistency and efficiency of the electroplating process.
A foam-suppressing electrolyte composition is developed, incorporating polypeptide proteins, sulfur-containing compounds, alcohol compounds, surfactants, thiourea derivatives, and thiazoline compounds to optimize electrolyte stability and promote uniform copper ion deposition, reducing surface tension and foam generation.
The optimized electrolyte composition enhances the stability and uniformity of the electroplating process, improving the mechanical strength and conductivity of the lithium battery copper foil, ensuring high-quality production with reduced surface defects and extended service life.
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Abstract
Description
Technical Field
[0001] The invention relates to the technical field of lithium battery copper foil preparation, and in particular to an anti-foaming electrolyte for lithium battery copper foil production. Background Art
[0002] With the rapid development of electric vehicles in recent years, the requirements for power sources are getting higher and higher. Lithium-ion secondary batteries have become the ideal power source for new energy vehicles due to their excellent performance. High-performance ultra-thin double-sided copper foil with a thickness of 6μm or less is an essential basic material for manufacturing high-end lithium-ion batteries. The market demand for high-performance ultra-thin double-sided lithium-ion copper foil is increasing day by day.
[0003] In actual production, in order to achieve ideal copper foil properties, the electrolyte used in the copper foil production system will gradually accumulate foam as a large amount of additives are added. These foams accumulate in the copper dissolving tank, which will isolate the copper material from the contact with sulfuric acid and reduce the copper dissolving rate. The foam layer will thicken to 5 cm, which will affect the observation and cause uneven distribution of copper material at the feeding port. The foam layer will continue to thicken and overflow from the filling port, causing corrosion and pollution, and even causing accidents. By increasing the copper dissolving temperature, the stability of the foam can be reduced, but the production energy consumption will increase, and the active ingredients of the additives will gradually fail at high temperatures. The characteristic of a copper foil factory is that as long as the electrolytic copper foil is produced, the electrolyte will always be in a circulating state. As the system circulation volume demand and the machine shutdown and startup operation, the flow rate of the electrolyte will fluctuate, pushing up the frequency and aggregation of foam. Foam accumulation in the dirty liquid tank, clean liquid tank or high-level tank will also cause overflow risks.
[0004] In view of the above-mentioned related technologies, the inventors found that the electrolyte used in the copper foil production system enters the raw foil end, and the discharge port is prone to accumulate foam, causing foil surface spots. The size and rupture of the foam will cause the appearance of the spots to change. The appearance of the spots is mostly whitish or shiny round or crescent-shaped. The physical method of spraying acid on the cathode roller surface can effectively separate the foam and reduce the spots, but it will cause the electric field at the discharge port to change, the current density to decrease, and the precipitation potential of copper ions to fluctuate, causing the physical properties of the copper to change, affecting the consistency of the physical properties of the copper foil. Therefore, foam is a major cause of copper foil quality degradation and scrap. Summary of the invention
[0005] In order to improve the defect that the electrolyte enters the raw foil end and foam is easily accumulated at the discharge port during the existing lithium battery copper foil preparation process, causing foil surface spots, the present application provides a foam-suppressing electrolyte for lithium battery copper foil production.
[0006] A foam-suppressing electrolyte for producing lithium copper foil comprises the following substances in parts by weight:
[0007]
[0008] The additives include polypeptide proteins with a molecular weight of 1000-10000.
[0009] Through the above technical solution, the present application optimizes the basic composition of the electrolyte, ensuring that the copper ion concentration, sulfuric acid concentration and chloride ion concentration during the electroplating process are within a reasonable range. The addition of sulfuric acid not only provides an acidic environment, but also improves the conductivity and promotes the reduction deposition of copper ions.
[0010] At the same time, the present application optimizes the chloride ion content, which can effectively inhibit the foam generation of the electrolyte and reduce the interference of the foam on the electroplating process. Then, by adding a modifier and using a high molecular weight polypeptide protein, the disordered deposition and arrangement of copper ions can be effectively inhibited, the roughness of the electroplating layer can be controlled, the electroplating effect can be optimized, the surface defects can be reduced, and the high-quality production of lithium battery copper foil can be ensured.
[0011] Furthermore, the modifier also includes a sulfur-containing compound, and the sulfur-containing compound includes at least one of sodium polydisulfide propane sulfonate, sodium alcohol mercaptopropane sulfonate, sodium 3-mercaptopropane cyclophosphate, and sodium 2-methyl-2-thiocarboxamidopropane sulfonate.
[0012] Through the above technical solution, the present application can effectively reduce the surface tension of the electrolyte, further reduce the generation of bubbles, and maintain the stability of the electrolyte by selecting sulfur-containing compounds for addition. The sulfur-containing compounds improve the deposition behavior of copper ions and promote the formation of a uniform electroplating layer, thus avoiding the common problems of uneven electroplating and roughness in the electroplating process. In addition, these modifiers can combine with copper ions through chemical reactions to form a protective film, enhance the adhesion and corrosion resistance of the electroplating layer, and further improve the performance of the final product.
[0013] Furthermore, the modifier also includes alcohol compounds and surfactant compounds.
[0014] Through the above technical scheme, the present application selects alcohol compounds and surfactant compounds. When used in practice, the alcohol compounds and surfactant compounds are dissolved in the foam liquid, which will significantly reduce the surface tension there. Because these substances generally have low solubility in water, the reduction in surface tension is limited to the local area of the foam, while the surface tension around the foam remains almost unchanged. The evenly dispersed alcohol compounds and surfactants penetrate into the foam elastic film and are distributed in the film, and the thin layer is broken due to the reduction in surface tension, thereby optimizing the electroplating effect, reducing surface defects, and ensuring high-quality production of lithium battery copper foil.
[0015] Furthermore, the alcohol compound includes at least one of polyethylene glycol 400-10000 or polypropylene glycol 200-1000.
[0016] Furthermore, the surfactant compound includes one or two of fatty amine polyoxyethylene ether and modified hydroxyethyl cellulose ether.
[0017] Through the above technical scheme, the present application significantly enhances the functionality of the electrolyte by adding alcohol compounds and surfactants. Since polyethylene glycol and polypropylene glycol, as alcohol compounds, have good wettability and fluidity, the physical properties of the electrolyte can be effectively improved, and the uniform dispersion of copper ions and the uniform deposition of the electroplating layer can be promoted. The molecular weight range of polyethylene glycol is between 400-10000, so that it can adjust the viscosity of the electrolyte as needed to adapt to different electroplating process requirements. At the same time, these alcohol compounds can also form a protective film during the electroplating process to prevent unnecessary impurities from depositing, thereby improving the compactness and uniformity of the electroplating layer. In addition, polypropylene glycol, as another option, has a moderate molecular weight that makes it have good fluidity and dispersibility in the electrolyte. These effects together make the electrolyte more stable in the production of lithium copper foil, and the quality of electroplating is significantly improved, providing a more reliable basis for subsequent battery applications.
[0018] Secondly, the present application uses fatty amine polyoxyethylene ether and modified hydroxyethyl cellulose ether, which can significantly improve the interfacial properties and fluidity of the electrolyte. These surfactants help reduce the bubbles generated during the electrolysis process by reducing the surface tension of the liquid, maintain the stability of the electrolyte, and thus prevent the occurrence of uneven electroplating. Fatty amine polyoxyethylene ether can effectively improve the wettability of the electrolyte, so that it forms good adhesion on the surface of the copper-based material, which is conducive to the uniform deposition of the copper layer. Modified hydroxyethyl cellulose ether can enhance the adhesion and fluidity of the electrolyte, ensuring the uniform distribution of copper ions on the electrode surface during the electroplating process. These effects not only improve the surface quality and finish of the electroplated layer, but also improve the conductivity of the lithium battery copper foil and its overall performance in the battery, ensuring the high efficiency and long life of the battery.
[0019] Furthermore, the modifier also includes thiourea derivatives and thiazoline compounds.
[0020] Furthermore, the thiourea derivatives include at least one of ethylenethiourea and propylenethiourea.
[0021] Furthermore, the thiazoline compound is sodium thiazoline dithiopropane sulfonate.
[0022] Through the above technical scheme, the present application further introduces thiourea derivatives and thiazoline compounds as modifiers, aiming to improve the functionality and performance stability of the electrolyte. Ethylene thiourea and propylene thiourea, due to their good chemical properties, can effectively control the foam generation of the electrolyte and prevent bubbles from disturbing the electroplating process. Through the interaction with copper ions and other components, thiourea compounds can promote the uniform deposition of the electroplating layer, improve the hardness and wear resistance of the electroplating layer, thereby significantly improving the performance of lithium battery copper foil. In addition, the protective effect of these derivatives in the electroplating process helps to form a denser electroplating layer, reduce the generation of pores and defects, and ensure the overall quality stability of the electroplating layer. In this way, the lithium battery copper foil finally produced not only performs well in conductivity, but also meets the needs of high-performance batteries in terms of service life and corrosion resistance.
[0023] Secondly, thiazoline compounds can promote the smooth deposition of copper ions through interaction with copper ions, improve the adhesion and structural density of the electroplating layer. In addition, they can form a protective film during the electroplating process to prevent the intrusion of external impurities and improve the wear resistance and corrosion resistance of the electroplating layer.
[0024] Furthermore, the mass ratio of the thiourea derivatives, thiazoline compounds, surfactant compounds, alcohol compounds, sulfur-containing compounds and polypeptide proteins with a molecular weight of 1000-10000 in the modifier is 1:3:30:30:30:30.
[0025] In summary, this application has the following beneficial effects:
[0026] First, the present application optimizes the basic composition of the electrolyte to ensure that the copper ion concentration, sulfuric acid concentration and chloride ion concentration during the electroplating process are within a reasonable range. The addition of sulfuric acid not only provides an acidic environment, but also improves the conductivity and promotes the reduction deposition of copper ions.
[0027] At the same time, the present application optimizes the chloride ion content, which can effectively inhibit the foam generation of the electrolyte and reduce the interference of the foam on the electroplating process. The addition of modifiers and the use of high molecular weight polypeptide proteins further enhance the stability and functionality of the electrolyte, optimize the electroplating effect, reduce surface defects, and ensure the high-quality production of lithium battery copper foil.
[0028] Second, the application can effectively reduce the surface tension of the electrolyte, further reduce the generation of bubbles, and maintain the stability of the electrolyte by adding sulfur-containing compounds. The sulfur-containing compounds improve the deposition behavior of copper ions and promote the formation of a uniform electroplating layer, thus avoiding the common problems of uneven electroplating and roughness in the electroplating process. In addition, these modifiers can combine with copper ions through chemical reactions to form a protective film, enhance the adhesion and corrosion resistance of the electroplating layer, and further improve the performance of the final product.
[0029] Third, the present application significantly enhances the functionality of the electrolyte by adding alcohol compounds and surfactants, especially alcohol compounds can effectively improve the fluidity of the electrolyte and promote the uniform distribution and deposition of copper ions. The surfactant further reduces the generation of bubbles by reducing the surface tension, ensuring the continuity and stability of the electroplating process. In addition, the surfactant helps to improve the compactness and smoothness of the electroplating layer, thereby reducing the formation of microscopic defects and holes. This optimized electrolyte can effectively improve the conductivity and mechanical strength of the lithium battery copper foil, and ultimately makes the lithium battery copper foil show more excellent electrical properties and service life in practical applications.
[0030] Fourth, the present application further introduces thiourea derivatives and thiazoline compounds as modifiers, aiming to improve the functionality and performance stability of the electrolyte. Thiourea derivatives such as ethylenethiourea and propylenethiourea, due to their excellent chemical stability and reactivity, can form effective antifoaming agents during the electrolysis process, reduce the generation of bubbles, and ensure the smooth progress of the electroplating process. At the same time, this type of compound can form a protective film during the deposition process of the electroplating layer, which helps to improve the adhesion and corrosion resistance of the electroplating layer, making the quality of the final product more excellent. In addition, the introduction of thiazoline compounds can further improve the dispersibility and stability of the electrolyte, improve the uniformity and density of the electroplating layer, and reduce the generation of macro and micro defects. These combined effects ensure the application quality of lithium battery copper foil in high-performance batteries and meet the strict requirements of battery materials in different fields. DETAILED DESCRIPTION
[0031] The present application is further described in detail below with reference to the embodiments.
[0032] In the examples of the present application, the raw materials and instruments used are as follows, but not limited thereto. Raw materials not otherwise described are of analytical grade:
[0033] Preparation Example 1
[0034] 300 parts of polypeptide protein with a molecular weight of 1000-10000, 400 parts of MD2, 200 parts of MD3 and 500 parts of MD4 were taken and stirred to prepare modifier 1, wherein the thiourea derivative and the thiazoline compound were prepared by combining ethylene thiourea and sodium thiazoline dithiopropane sulfonate in a ratio of 1:3, and the surfactant compound and the alcohol compound were prepared by combining modified hydroxyethyl cellulose ether and polyethylene glycol 400 in a ratio of 1:1.
[0035] Preparation Example 2
[0036] Take 400 parts of polypeptide protein with a molecular weight of 1000-10000, 500 parts of MD2, 250 parts of MD3 and 600 parts of MD4, stir and mix, and prepare modifier 2, wherein the thiourea derivative and the thiazoline compound are prepared by combining propylene thiourea and sodium thiazoline dithiopropane sulfonate in a ratio of 1:3, and the surfactant compound and the alcohol compound are prepared by combining modified hydroxyethyl cellulose ether and polypropylene glycol 200 in a ratio of 1:1.
[0037] Preparation Example 3
[0038] Take 500 parts of polypeptide protein with a molecular weight of 1000-10000, 600 parts of MD2, 300 parts of MD3 and 700 parts of MD4, stir and mix, and prepare modifier 3, wherein the thiourea derivative and the thiazoline compound are prepared by combining ethylene thiourea and sodium thiazoline dithiopropane sulfonate in a ratio of 1:3, and the surfactant compound and the alcohol compound are prepared by combining fatty amine polyoxyethylene ether and polyethylene glycol 800 in a ratio of 1:1.
[0039] Preparation Example 4
[0040] Take 550 parts of polypeptide protein with a molecular weight of 1000-10000, 650 parts of MD2, 300 parts of MD3 and 800 parts of MD4, stir and mix, and prepare modifier 4, wherein the thiourea derivative and the thiazoline compound are prepared by combining ethylene thiourea and sodium thiazoline dithiopropane sulfonate in a ratio of 1:3, and the surfactant compound and the alcohol compound are prepared by combining fatty amine polyoxyethylene ether and polypropylene glycol 800 in a ratio of 1:1.
[0041] Example 1
[0042] An application method of an anti-foaming electrolyte for lithium battery copper foil production comprises the following preparation steps:
[0043] The electrolyte composition is 85g / L copper ion, 110g / L sulfuric acid and 25mg / L chloride ion; at an addition rate of 200g / h, modifier 1 is added to the electrolyte and circulated to the clean liquid tank for 3h. After the cathode roller surface acid spraying is turned off, there is no foam accumulation in the foil machine. Except for a small amount of foam observed in the copper dissolving tank, no foam is found in other tanks. The electrolyte temperature is 52℃; the current density of the cathode rod is 60A / cm 2 ; The linear speed of the cathode rod is 11.3m / min; and the flow rate of the copper sulfate electrolyte containing the additive through the electrolytic cell is 55m 3 / h. The 6-micron copper foil is produced by the foil machine. The raw foil is treated with conventional chromic anhydride aqueous solution to obtain electrolytic raw foil.
[0044] Example 2
[0045] An application method of an anti-foaming electrolyte for lithium battery copper foil production comprises the following preparation steps:
[0046] The electrolyte composition is 85g / L copper ion, 110g / L sulfuric acid and 25mg / L chloride ion; at an addition rate of 200g / h, modifier 2 is added to the electrolyte and circulated to the clean liquid tank for 3h. After the cathode roller surface acid spray is turned off, there is no foam accumulation in the foil machine. Except for a small amount of foam observed in the copper dissolving tank, no foam is found in other tanks. The electrolyte temperature is 52℃; the current density of the cathode rod is 60A / cm 2 ; The linear speed of the cathode rod is 11.3m / min; and the flow rate of the copper sulfate electrolyte containing the additive through the electrolytic cell is 55m 3 / h. The 6-micron copper foil is produced by the foil machine. The raw foil is treated with conventional chromic anhydride aqueous solution to obtain electrolytic raw foil.
[0047] Example 3
[0048] An application method of an anti-foaming electrolyte for lithium battery copper foil production comprises the following preparation steps:
[0049] The electrolyte composition is 85g / L copper ion, 110g / L sulfuric acid and 25mg / L chloride ion; at an addition rate of 200g / h, modifier 3 is added to the electrolyte to the clean liquid tank for circulation for 3h. After the cathode roller surface acid spraying is turned off, there is no foam accumulation in the foil machine. Except for a small amount of foam observed in the copper dissolving tank, no foam is found in other tanks. The electrolyte temperature is 52℃; the current density of the cathode roller is 60A / cm 2 ; The linear speed of the cathode rod is 11.3m / min; and the flow rate of the copper sulfate electrolyte containing the additive through the electrolytic cell is 55m 3 / h. The 6-micron copper foil is produced by the foil machine. The raw foil is treated with conventional chromic anhydride aqueous solution to obtain electrolytic raw foil.
[0050] Example 4
[0051] An application method of an anti-foaming electrolyte for lithium battery copper foil production comprises the following preparation steps:
[0052] The electrolyte composition is 85g / L copper ion, 110g / L sulfuric acid and 25mg / L chloride ion; at an addition rate of 200g / h, modifier 4 is added to the electrolyte and circulated to the clean liquid tank for 3h. After the cathode roller surface acid spraying is turned off, there is no foam accumulation in the foil machine. Except for a small amount of foam observed in the copper dissolving tank, no foam is found in other tanks. The electrolyte temperature is 52℃; the current density of the cathode rod is 60A / cm 2 ; The linear speed of the cathode rod is 11.3m / min; and the flow rate of the copper sulfate electrolyte containing the additive through the electrolytic cell is 55m 3 / h. The 6-micron copper foil is produced by the foil machine. The raw foil is treated with conventional chromic anhydride aqueous solution to obtain electrolytic raw foil.
[0053] Performance Testing
[0054] The electrolytic raw foils prepared in Examples 1-4 were subjected to performance tests, specifically testing their mechanical properties and the number of foil surface spots:
[0055] (1) Elongation: The test method and specimen size shall be in accordance with GB / T 29847-2013.
[0056] (2) Tensile strength: The test method and specimen size shall be in accordance with GB / T 29847-2013.
[0057] (3) Foil surface spots (number): Observation method
[0058] The recorded results are shown in Table 1 below:
[0059] Table 1 Performance test table
[0060] sample Tensile strength(Mpa) Elongation(%) Foil surface spot printing (number) Example 1 554.35 6.82 0 Example 2 572.25 6.02 0 Example 3 581.42 5.72 0 Example 4 590.33 5.52 0
[0061] From the comparison of the test results of the above embodiments 1-4, it can be found that:
[0062] The technical schemes of Examples 1-4 further illustrate that the additives prepared in the present application can effectively break and suppress bubbles when added to copper sulfate electrolyte, shield the harm caused by bubbles, and the lithium battery copper foil prepared under certain conditions has good physical properties, and the baking tensile strength and elongation are both high. The present invention uses thiourea derivatives and thiazoline compounds to enhance the physical properties of copper foil.
[0063] The present invention has been described in detail above in conjunction with specific implementations and exemplary examples, but these descriptions cannot be understood as limiting the present invention. Those skilled in the art understand that, without departing from the spirit and scope of the present invention, a variety of equivalent substitutions, modifications or improvements may be made to the technical solution of the present invention and its implementation methods, all of which fall within the scope of the present invention. The scope of protection of the present invention shall be subject to the attached claims.
[0064] All publications, patent applications, patents and other references mentioned in this specification are incorporated herein by reference. Unless otherwise defined, all technical and scientific terms used in this specification have the meanings conventionally understood by those skilled in the art. In the event of a conflict, the definition in this specification shall prevail.
[0065] When this specification uses the prefix "well-known to those skilled in the art", "prior art" or similar terms to introduce materials, substances, methods, steps, devices or components, etc., the objects introduced by the prefix cover those commonly used in the art when this application is filed, but also include those that are not commonly used at present but will become recognized in the art as being suitable for similar purposes.
[0066] In the context of the present specification, any matters or items not mentioned are directly applicable to those known in the art without any changes except those explicitly stated.
Claims
1. A foam-suppressing electrolyte for lithium battery copper foil production, characterized in that: The composition includes the following materials in parts by weight: The additives include polypeptide proteins with a molecular weight of 1000-10000.
2. The anti-foaming electrolyte for lithium battery copper foil production according to claim 1, characterized in that: The modifier further includes a sulfur-containing compound, and the sulfur-containing compound includes at least one of sodium polydisulfide propane sulfonate, sodium alcohol mercaptopropane sulfonate, sodium 3-mercaptopropane cyclophosphate, and sodium 2-methyl-2-thiocarboxamidopropane sulfonate.
3. The anti-foaming electrolyte for lithium battery copper foil production according to claim 2, characterized in that: The modifier also includes alcohol compounds and surfactant compounds.
4. The anti-foaming electrolyte for lithium battery copper foil production according to claim 3, characterized in that: The alcohol compound includes at least one of polyethylene glycol 400-10000 or polypropylene glycol 200-1000.
5. The anti-foaming electrolyte for lithium battery copper foil production according to claim 3, characterized in that: The surfactant compound includes one or two of fatty amine polyoxyethylene ether and modified hydroxyethyl cellulose ether.
6. The anti-foaming electrolyte for lithium battery copper foil production according to claim 3, characterized in that: The modifier also includes thiourea derivatives and thiazoline compounds.
7. The anti-foaming electrolyte for lithium battery copper foil production according to claim 6, characterized in that: The thiourea derivatives include at least one of ethylenethiourea and propylenethiourea.
8. The anti-foaming electrolyte for lithium battery copper foil production according to claim 6, characterized in that: The thiazoline compound is sodium thiazoline dithiopropane sulfonate.
9. The anti-foaming electrolyte for lithium battery copper foil production according to claim 6, characterized in that: The mass ratio of thiourea derivatives, thiazoline compounds, surfactant compounds, alcohol compounds, sulfur-containing compounds and polypeptide proteins with a molecular weight of 1000-10000 in the modifier is 1:3:30:30:30:30.