Electrolyte and method for preparing high-tensile electrolytic copper foil

Abstract

The invention discloses an electrolyte and a method for preparing high-tensile-strength electrolytic copper foil, and relates to the technical field of electrolytic copper foil manufacturing, the electrolyte and the method for preparing the high-tensile-strength electrolytic copper foil comprise main salt copper sulfate pentahydrate, deionized water, concentrated sulfuric acid and 2-mercaptothiazolin.According to the technical scheme, the high-tensile-strength electrolytic copper foil is prepared from the main salt copper sulfate pentahydrate, the deionized water, the concentrated sulfuric acid and the 2-mercaptothiazoline. The concentration of the copper sulfate pentahydrate in the electrolyte is 85-120 g / L, preferably 85 g / L, 100 g / L or 120 g / L. According to the technical scheme, the concentration of the concentrated sulfuric acid is 40-100 g / L, preferably 40 g / L, 70 g / L or 100 g / L. According to the technical scheme, the concentration of the 2-mercaptothiazoline is 9-18 mg / L, preferably 9 mg / L, 12 mg / L or 18 mg / L. According to the electrolyte and the method for preparing the high-tensile electrolytic copper foil, a copper sulfate plating solution system is adopted for preparing the electrolyte, and a novel additive 2-mercaptothiazoline is added, so that the high-tensile electrolytic copper foil is prepared. The method can effectively refine crystal grains and enhance electrochemical polarity and nucleation density, the prepared copper foil is good in brightness and high in strength, the application stability of the electrolytic copper foil is greatly improved, and meanwhile operation is easy.

Description

Technical Field

[0001] The invention relates to the technical field of electrolytic copper foil manufacturing, in particular to an electrolyte and a method for preparing high-tensile-strength electrolytic copper foil. Background Art

[0002] Copper foil, a crucial "connector" for electronic information transmission, is a key building block for lithium-ion batteries, copper-clad laminates, and circuit boards. It is widely used in new energy vehicles, electronic circuits, aerospace, and other fields. With the rapid advancement of technology in recent years, various electronic products have gradually become thinner and lighter, with longer battery life. Electrolytic copper foil, a key material for circuit boards and lithium battery anodes, has become increasingly prominent, but also faces greater challenges. Lithium battery copper foil typically serves as the anode current collector in lithium batteries. The thickness of the copper foil directly affects the battery's energy density and battery life: thinner copper foil improves battery life and increases performance requirements. Kataoka et al. have pointed out that current collectors with high tensile strength can provide higher battery capacity after certain electrochemical cycles. During the battery's electrochemical cycle, the electrode material undergoes repeated expansion and contraction due to continuous charge and discharge. This volume change can lead to fracture and battery damage. Therefore, lithium battery copper foil used in battery anodes must not only be lightweight but also possess high tensile strength to meet the application environment and stress requirements. Summary of the Invention

[0003] In view of the deficiencies in the prior art, the present invention provides an electrolyte and method for preparing high-tensile-strength electrolytic copper foil, which solves the problems raised in the above-mentioned background technology.

[0004] To achieve the above objectives, the present invention is implemented through the following technical solutions: a preparation method of a high-tensile electrolytic copper foil electrolyte, including a main salt of copper sulfate pentahydrate, deionized water, concentrated sulfuric acid and 2-mercaptothiazoline.

[0005] According to the above technical solution, the concentration of the copper sulfate pentahydrate in the electrolyte is 85-120 g / L, preferably 85 g / L, 100 g / L or 120 g / L.

[0006] According to the above technical solution, the concentration of concentrated sulfuric acid is 40-100 g / L, preferably 40 g / L, 70 g / L or 100 g / L.

[0007] According to the above technical solution, the concentration of 2-mercaptothiazoline is 9-18 mg / L, preferably 9 mg / L, 12 mg / L or 18 mg / L.

[0008] According to the above technical solution, polyvinyl pyrrolidone (PVP) is also included, and the concentration of polyvinyl pyrrolidone (PVP) is 0.45-0.9 mg / L, preferably 0.45 mg / L, 0.6 mg / L or 0.9 mg / L.

[0009] According to the above technical solution, the following steps are also included: S1. Raw material purification: Filter concentrated sulfuric acid through a 5μm polypropylene filter element and filter deionized water through a 0.45μm microporous membrane at one time; S2. Dissolve the main salt: Add copper sulfate pentahydrate to 52°C deionized water, stir (200-300 rpm) and dissolve until clear, then slowly pour concentrated sulfuric acid into it in multiple times to generate a basic acidic electrolyte; S3. Solution combination: dissolve 2-mercaptothiazoline and polyvinylpyrrolidone (PVP) in 40°C deionized water, stir for 10 minutes until completely dissolved, and then introduce the cooled basic acid electrolyte; S4, mixed filtration: Stir the mixed solution for 30 minutes to ensure that there is no stratification, and then filter it using a 5 μm disposable filter cartridge; S5. Filtration to prevent precipitation: Keep stirring at a low speed (100-150rpm) during the electrolysis process to prevent precipitation. Rinse the surface with clean water after leaving the tank and dry naturally.

[0010] The present invention provides an electrolyte and method for preparing high-tensile-strength electrolytic copper foil. It has the following beneficial effects: (1) The electrolyte and method for preparing high-tensile electrolytic copper foil adopt a copper sulfate plating solution system to prepare the electrolyte, and add a new additive 2-mercaptothiazoline, which can effectively refine the grains, enhance the electrochemical polarity and nucleation density. The prepared copper foil has good brightness and high strength, greatly improving the stability of the application of electrolytic copper foil and simple operation.

[0011] (2) The electrolyte and method for preparing high-tensile electrolytic copper foil can quickly intercept large particles of impurities and mechanical pollutants by filtering concentrated sulfuric acid through a polypropylene filter element, reducing the wear on subsequent reaction equipment. At the same time, the microporous filter membrane filters deionized water at one time, which can effectively remove suspended particles and some large molecular organic matter, reduce the impurity content in the electrolyte, improve the purity and density of the copper foil, and thus enhance its tensile properties.

[0012] (3) The electrolyte and method for preparing high-tensile electrolytic copper foil are as follows: copper sulfate pentahydrate is dissolved in deionized water at 52°C. This temperature can accelerate the dissolution rate of copper sulfate while avoiding excessive evaporation of water due to excessive temperature; concentrated sulfuric acid is slowly poured in multiple times, which can effectively control the reaction temperature, prevent local overheating, make the basic acid electrolyte more evenly mixed, ensure the stability of the electrolyte components, and lay the foundation for the subsequent uniform deposition of copper ions.

[0013] (4) The method for preparing the electrolyte of high-tensile electrolytic copper foil comprises the following steps: dissolving 2-mercaptothiazoline and polyvinylpyrrolidone (PVP) in deionized water at 40°C and stirring for 10 minutes, which can fully dissolve the additive to form a uniform pre-activated solution, and introducing the pre-activated solution into the cooled basic acidic electrolyte to reduce the uneven local reaction caused by temperature differences, and help the additive to be evenly dispersed in the electrolyte, further enhancing its regulating effect on the crystallization process of the copper foil, refining the copper foil grains, and improving the tensile strength.

[0014] (5) The electrolyte and method for preparing high-tensile electrolytic copper foil use a disposable filter element for filtration, which can effectively intercept undissolved tiny particles, impurities and additive agglomerates, prevent them from affecting the surface quality of the copper foil during the electrolysis process, reduce the probability of defects such as pinholes and pitting, and improve the surface flatness and smoothness of the copper foil.

[0015] (6) The electrolyte and method for preparing high-tensile electrolytic copper foil maintain low-speed stirring during the electrolysis process, which can prevent the sedimentation of additives and copper ions without affecting the electrolysis reaction, maintain the stability of the electrolyte composition, and ensure the uniform growth of the copper foil during the electrolysis process. After leaving the tank, the surface is rinsed with clean water and dried naturally to remove residual electrolyte and impurities on the surface, avoiding the adverse effects of residual substances on the performance of the copper foil. At the same time, the natural drying method is simple and easy to operate, reducing additional energy consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the process structure of the present invention; Figure 2 Schematic diagram of experimental results of the present invention; Figure 3 This is the SEM image obtained in Example 1 of the present invention; Figure 4 This is the SEM image obtained in Example 2 of the present invention; Figure 5 This is the SEM image obtained in Example 3 of the present invention. DETAILED DESCRIPTION

[0017] The following will provide a clear and complete description of the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. All other embodiments obtained by ordinary technicians in this field based on the embodiments of the present invention without making any creative efforts shall fall within the scope of protection of the present invention.

[0018] See also Figure 1-Figure 5 One embodiment of the present invention is: a method for preparing an electrolyte for high-tensile electrolytic copper foil, comprising a main salt of copper sulfate pentahydrate, deionized water, concentrated sulfuric acid and 2-mercaptothiazoline.

[0019] Example 1: comprising 85 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 40 g of concentrated sulfuric acid, 9 mg of 2-mercaptothiazoline and 0.45 mg of polyvinylpyrrolidone (PVP).

[0020] A method for preparing an electrolyte for high-tensile-strength electrolytic copper foil comprises the following steps: S1. Raw material purification: Filter 40 g of concentrated sulfuric acid through a 5 μm polypropylene filter cartridge and simultaneously filter 1 L of deionized water through a 0.45 μm microporous membrane. S2. Dissolve the main salt: Add 85g of copper sulfate pentahydrate to 52°C deionized water, stir (200-300rpm) and dissolve until clear, then slowly pour 40g of concentrated sulfuric acid in several times to generate a basic acidic electrolyte; S3. Solution combination: Dissolve 9 mg of 2-mercaptothiazoline and 0.45 mg of polyvinylpyrrolidone (PVP) in 40°C deionized water, stir for 10 minutes until completely dissolved, and then introduce the cooled basic acidic electrolyte; S4, mixed filtration: Stir the mixed solution for 30 minutes to ensure that there is no stratification, and then filter it using a 5 μm disposable filter cartridge; S5. Filtration to prevent precipitation: Keep stirring at a low speed (100-150rpm) during the electrolysis process to prevent precipitation. Rinse the surface with clean water after leaving the tank and dry naturally.

[0021] Example 2: comprising 100 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 70 g of concentrated sulfuric acid, 12 mg of 2-mercaptothiazoline and 0.6 mg of polyvinylpyrrolidone (PVP).

[0022] A method for preparing an electrolyte for high-tensile-strength electrolytic copper foil comprises the following steps: S1. Raw material purification: Filter 70 g of concentrated sulfuric acid through a 5 μm polypropylene filter cartridge and simultaneously filter 1 L of deionized water through a 0.45 μm microporous membrane. S2. Dissolve the main salt: Add 100g of copper sulfate pentahydrate to 52°C deionized water, stir (200-300rpm) and dissolve until clear, then slowly pour 70g of concentrated sulfuric acid in several times to generate a basic acidic electrolyte; S3. Solution combination: dissolve 12 mg of 2-mercaptothiazoline and 0.6 mg of polyvinylpyrrolidone (PVP) in 40°C deionized water, stir for 10 minutes until completely dissolved, and then introduce the cooled basic acidic electrolyte; S4, mixed filtration: Stir the mixed solution for 30 minutes to ensure that there is no stratification, and then filter it using a 5 μm disposable filter cartridge; S5. Filtration to prevent precipitation: Keep stirring at a low speed (100-150rpm) during the electrolysis process to prevent precipitation. Rinse the surface with clean water after leaving the tank and dry naturally.

[0023] Example 3: comprising 120 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 100 g of concentrated sulfuric acid, 18 mg of 2-mercaptothiazoline and 0.9 mg of polyvinylpyrrolidone (PVP).

[0024] A method for preparing an electrolyte for high-tensile-strength electrolytic copper foil comprises the following steps: S1. Raw material purification: Filter 100 g of concentrated sulfuric acid through a 5 μm polypropylene filter cartridge and simultaneously filter 1 L of deionized water through a 0.45 μm microporous membrane. S2. Dissolve the main salt: Add 120g of copper sulfate pentahydrate to 52°C deionized water, stir (200-300rpm) and dissolve until clear, then slowly pour 100g of concentrated sulfuric acid in several times to generate a basic acidic electrolyte; S3. Solution combination: Dissolve 18 mg of 2-mercaptothiazoline and 0.9 mg of polyvinylpyrrolidone (PVP) in 40°C deionized water, stir for 10 minutes until completely dissolved, and then introduce the cooled basic acidic electrolyte; S4, mixed filtration: Stir the mixed solution for 30 minutes to ensure that there is no stratification, and then filter it using a 5 μm disposable filter cartridge; S5. Filtration to prevent precipitation: Keep stirring at a low speed (100-150rpm) during the electrolysis process to prevent precipitation. Rinse the surface with clean water after leaving the tank and dry naturally.

[0025] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions, and variations may be made to these embodiments without departing from the principles and spirit of the invention, and that the scope of the invention is defined by the appended claims and their equivalents.

Claims

1. A method for preparing an electrolyte for high-tensile electrolytic copper foil, characterized in that: The invention comprises main salt copper sulfate pentahydrate, deionized water, concentrated sulfuric acid and 2-mercaptothiazoline.

2. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 1, characterized in that: The concentration of the copper sulfate pentahydrate in the electrolyte is 85-120 g / L, preferably 85 g / L, 100 g / L or 120 g / L.

3. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 2, characterized in that: The concentration of the concentrated sulfuric acid is 40-100 g / L, preferably 40 g / L, 70 g / L or 100 g / L.

4. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 3, characterized in that: The concentration of the 2-mercaptothiazoline is 9-18 mg / L, preferably 9 mg / L, 12 mg / L or 18 mg / L.

5. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 4, characterized in that: Polyvinyl pyrrolidone (PVP) is also included, and the concentration of polyvinyl pyrrolidone (PVP) is 0.45-0.9 mg / L, preferably 0.45 mg / L, 0.6 mg / L or 0.9 mg / L.

6. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 5, characterized in that: The following steps are also included: S1. Raw material purification: Filter concentrated sulfuric acid through a 5μm polypropylene filter element and filter deionized water through a 0.45μm microporous membrane at one time; S2. Dissolve the main salt: Add copper sulfate pentahydrate to 52°C deionized water, stir (200-300 rpm) and dissolve until clear, then slowly pour concentrated sulfuric acid into it in multiple times to generate a basic acidic electrolyte; S3. Solution combination: dissolve 2-mercaptothiazoline and polyvinylpyrrolidone (PVP) in 40°C deionized water, stir for 10 minutes until completely dissolved, and then introduce the cooled basic acid electrolyte; S4, mixed filtration: Stir the mixed solution for 30 minutes to ensure that there is no stratification, and then filter it using a 5 μm disposable filter cartridge; S5. Filtration to prevent precipitation: Keep stirring at a low speed (100-150rpm) during the electrolysis process to prevent precipitation. Rinse the surface with clean water after leaving the tank and dry naturally.

7. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 6, characterized in that: The preparation method comprises 85 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 40 g of concentrated sulfuric acid, 9 mg of 2-mercaptothiazoline and 0.45 mg of polyvinylpyrrolidone (PVP).

8. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 6, characterized in that: The preparation method comprises 100 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 70 g of concentrated sulfuric acid, 12 mg of 2-mercaptothiazoline and 0.6 mg of polyvinylpyrrolidone (PVP).

9. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 6, characterized in that: The preparation method comprises 120 g of main salt copper sulfate pentahydrate, 1 L of deionized water, 100 g of concentrated sulfuric acid, 18 mg of 2-mercaptothiazoline and 0.9 mg of polyvinylpyrrolidone (PVP).

10. The electrolyte and method for preparing high-tensile strength electrolytic copper foil according to claim 1, characterized in that: This method is used in the production of electrolytic copper foil.

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