Electrolyte, electrolytic copper foil with high tensile strength and preparation method of electrolytic copper foil

Abstract

The invention discloses an electrolyte, an electrolytic copper foil with high tensile strength and a preparation method of the electrolytic copper foil, and relates to the technical field of electrolytic copper foils. The electrolyte provided by the invention comprises H2SO4, Cu < 2 + >, Cl <->, N, N-dimethyl dithiocarbonyl sodium propane sulfonate, polyvinyl alcohol, hydroxyethyl cellulose, sodium hyaluronate and baicalin. The electrolytic copper foil prepared through the method is lighter and thinner, and meanwhile the tensile strength is higher.

Description

Technical Field

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

[0002] Electrolytic copper foil is the basic raw material of the electronics industry. Through direct current electroplating technology, insoluble metals (such as lead, titanium plated with iridium) are used as anodes and titanium rollers are used as cathodes. The copper sulfate solution is passed through the electrolytic cell composed of the anode and the cathode and direct current is passed for electrolysis. The copper ions in the electrolyte obtain electrons and are deposited on the surface of the titanium roller to form copper foil. It has gradually been widely used in various fields, especially in the electronics industry. For example, it is used in printed circuit boards (PCBs) and copper-clad laminates (CCLs), which play an important role in electronic signal transmission, power transmission, and communication, and is called a "neural network". In the practical production of electrolytic copper foil, the quality and stability of the product mainly depend on the formula and addition method of the additives. There are many formulas for electrolytic copper foil additives, and different formulas can adjust different product grain structures. In the industrial production of electrolytic copper foil, multiple additives are usually used for compounding to obtain copper foil with better comprehensive performance. Since there may be synergistic or antagonistic effects between different additives, the joint use of multiple additives can effectively improve the copper electrodeposition process and improve the effect of the additives.

[0003] Copper foil is the negative electrode current collector of lithium-ion batteries, and its tensile strength and other properties directly affect the performance of lithium-ion batteries. By adjusting the additive system, the electrolytic copper foil process can be effectively improved, thereby improving the performance of copper foil. The additives of electrolytic copper foil are mainly divided into three types: brightener, leveler and wetting agent according to their different functions. In the copper electrodeposition process, adding suitable additives can effectively improve the crystallization of the copper layer and control the grain growth, thereby reducing the thickness of the copper foil and improving the surface properties of the copper foil, resulting in a thinner, lower-cost copper foil with better mechanical properties.

[0004] Chinese patent CN117822066A discloses an additive for preparing electrolytic copper foil, electrolytic copper foil and preparation method thereof. The additive comprises functional carbon nanotubes, brightener, leveler and wetting agent, wherein the surface groups of the functional carbon nanotubes can react with the brightener to generate thiourea-like groups. The electrolytic copper foil prepared by using the additive of the invention has excellent elongation and tensile strength.

[0005] Chinese patent CN111286745A discloses an additive for high-tensile electrolytic copper foil, an electrolytic copper foil and a preparation method thereof, and a lithium-ion battery, and relates to the technical field of electrolytic copper foil. The additive for high tensile electrolytic copper foil comprises an agent A and an agent B, wherein the agent A comprises the following components in parts by mass: 6-17 parts of sulfur-containing propane sulfonate, 5-30 parts of polyethyleneimine and its derivatives and 0.5-10 parts of thiourea; the agent B comprises the following components in parts by mass: 5-15 parts of gelatin and 0.01-0.5 parts of tea polyphenols; the mass ratio of the agent A to the agent B is 55-520:40-240, which alleviates the technical problems of unstable winding, easy wrinkling, easy tearing, rough crystallization, and easy breakage and wrinkling of traditional electrolytic copper foil during the production process, and the additive for high tensile electrolytic copper foil can improve the tensile strength and elongation of the electrolytic copper foil, reduce the roughness of the rough surface, and effectively improve the energy density of the battery core. At the same time, the preparation method is simple and the use is simple and quick.

[0006] Currently, lithium-ion batteries are mainly developing towards the trend of "lightness and thinness". It is still urgent to study how to make electrolytic copper foil have good elongation and tensile strength while having a low thickness. Summary of the invention

[0007] In view of this, an object of the present invention is to provide an electrolyte, an electrolytic copper foil with high tensile strength and a preparation method thereof, wherein the prepared electrolytic copper foil is lighter and thinner and has higher tensile strength.

[0008] To achieve the above-mentioned purpose of the invention, the technical solution of the present invention is as follows:

[0009] In one aspect, the present invention provides an electrolyte comprising H2SO4, Cu 2+ , Cl - , sodium N,N-dimethyldithiocarbonylpropane sulfonate, polyvinyl alcohol, hydroxyethyl cellulose, sodium hyaluronate and baicalin.

[0010] Preferably, the electrolyte includes H2SO4 100-120g / L, Cu 2+ 60-100g / L, Cl - 10-30mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1-5mg / L, polyvinyl alcohol 1-10mg / L, hydroxyethyl cellulose 10-30mg / L, sodium hyaluronate 1-10mg / L and baicalin 0.1-2mg / L.

[0011] Further preferably, the electrolyte includes H2SO4 110g / L, Cu 2+ 80g / L, Cl -20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 20mg / L, sodium hyaluronate 5mg / L and baicalin 1mg / L.

[0012] In another aspect, the present invention provides a method for preparing an electrolytic copper foil, comprising the following steps: electrolyzing the above-mentioned electrolyte to obtain the electrolytic copper foil.

[0013] Preferably, the method for preparing the electrolytic copper foil comprises the following steps:

[0014] An electrolyte is supplied between an anode plate and a cathode roller, and a voltage is applied between the anode plate and the cathode roller to perform electrolysis, thereby forming the electrolytic copper foil on the surface of the cathode roller.

[0015] Further preferably, the conditions for the electrolysis are:

[0016] Electrolysis temperature 50-55℃, bath flow 3-7m 3 / h, current density 40-70A / dm 2 .

[0017] More preferably, the conditions for the electrolysis are:

[0018] Constant current power supply, anode is titanium plated with iridium, cathode is pure titanium, electrolysis temperature is 52°C, plating solution flow rate is 5m 3 / h, current density is 60A / dm 2 , the copper foil thickness is 4μm.

[0019] More preferably, the roughness of the cathode roller is 0.13-0.15 Ra.

[0020] More preferably, the rotation speed of the cathode roller during electrolysis is 7-9 m / min.

[0021] In another aspect, the present invention provides an electrolytic copper foil prepared by the above preparation method.

[0022] Preferably, the copper foil has a thickness of 3-5 μm and a tensile strength of >450 MPa.

[0023] Further preferably, the copper foil has a thickness of 4 μm and a tensile strength of >460 MPa.

[0024] In another aspect, the present invention provides a copper-clad laminate comprising the above-mentioned electrolytic copper foil.

[0025] In still another aspect, the present invention provides a printed wiring board comprising the above-mentioned electrolytic copper foil.

[0026] In another aspect, the present invention provides a method for manufacturing a printed wiring board, which is prepared using the electrolytic copper foil.

[0027] On the other hand, the present invention provides a method for manufacturing a printed wiring board, comprising the following steps: laminating the above-mentioned electrolytic copper foil and an insulating substrate to form a copper-clad laminate, and then forming a circuit by any one of a semi-additive method, a subtractive method, a partial additive method or a modified semi-additive method.

[0028] In still another aspect, the present invention provides a method for manufacturing an electronic device, wherein the method comprises manufacturing the electronic device using the printed wiring board.

[0029] The beneficial effects of the present invention are:

[0030] The invention provides an electrolytic copper foil with high tensile strength and a preparation method thereof. A new electrolytic additive formula is screened and formulated. Sodium N,N-dimethyldithiocarbonylpropane sulfonate, polyvinyl alcohol, hydroxyethyl cellulose, sodium hyaluronate and baicalin show a synergistic promotion effect in the copper electrocrystallization process, strengthen the grain refinement effect, and significantly improve the tensile strength and other properties of the electrolytic copper foil, thereby ensuring that the prepared electrolytic copper foil is lighter and thinner while having higher tensile strength. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The following are electron microscope images of copper foils prepared in the embodiments and comparative examples of the present invention. DETAILED DESCRIPTION

[0032] The following non-limiting examples can enable those skilled in the art to more fully understand the present invention, but do not limit the present invention in any way. The following content is merely an exemplary description of the scope of the present invention, and those skilled in the art can make various changes and modifications to the present invention based on the disclosed content, which should also fall within the scope of the present application.

[0033] Electrolyte preparation method:

[0034] (1) adding the formulated amount of sodium N,N-dimethyldithiocarbonylpropane sulfonate, polyvinyl alcohol, hydroxyethyl cellulose, and sodium hyaluronate to a hydrochloric acid solution, and ultrasonically treating the solution at 500 W for 15 min to obtain a mixed solution 1;

[0035] (2) Mix the mixed solution 1 and the acidic copper sulfate solution, add the formulated amount of baicalin, mix well, and obtain an electrolyte.

[0036] Experimental Materials:

[0037]

[0038] Example 1

[0039] Electrolyte composition: H2SO4 110g / L, Cu 2+ 80g / L, Cl - 20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 20mg / L, sodium hyaluronate 5mg / L and baicalin 1mg / L.

[0040] Preparation of electrolytic copper foil:

[0041] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0042] Example 2

[0043] Electrolyte composition: H2SO4 100g / L, Cu 2+ 60g / L, Cl - 10mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1mg / L, polyvinyl alcohol 1mg / L, hydroxyethyl cellulose 10mg / L, sodium hyaluronate 1mg / L and baicalin 0.1mg / L.

[0044] Preparation of electrolytic copper foil:

[0045] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0046] Example 3

[0047] Electrolyte composition: H2SO4 120g / L, Cu 2+ 10g / L, Cl - 30mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 5mg / L, polyvinyl alcohol 10mg / L, hydroxyethyl cellulose 30mg / L, sodium hyaluronate 10mg / L and baicalin 2mg / L.

[0048] Preparation of electrolytic copper foil:

[0049] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0050] Comparative Example 1

[0051] Electrolyte composition: H2SO4 110g / L, Cu 2+ 80g / L, Cl - 20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 20mg / L and baicalin 1mg / L.

[0052] Preparation of electrolytic copper foil:

[0053] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0054] Comparative Example 2

[0055] Electrolyte composition: H2SO4 110g / L, Cu 2+ 80g / L, Cl - 20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 20mg / L and sodium hyaluronate 5mg / L.

[0056] Preparation of electrolytic copper foil:

[0057] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0058] Comparative Example 3

[0059] Electrolyte composition: H2SO4 110g / L, Cu 2+ 80g / L, Cl - 20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 10mg / L, sodium hyaluronate 15mg / L and baicalin 5mg / L.

[0060] Preparation of electrolytic copper foil:

[0061] Electrolyte was supplied between the titanium-plated iridium anode plate and the pure titanium cathode roller, and voltage was applied between the anode plate and the cathode roller to perform electrolysis at an electrolysis temperature of 52°C and a plating solution flow rate of 5m 3 / h, current density is 60A / dm 2 The roughness of the cathode roller is 0.14Ra, the rotation speed of the cathode roller is 8m / min, and the electrolytic copper foil is formed on the surface of the cathode roller, and the thickness of the copper foil is 4μm.

[0062] Results

[0063] The tensile strength of the copper foil was tested using an electronic universal testing machine, and the roughness of the matte surface of the copper foil was measured using an M300C surface roughness tester. Ten samples were tested for each embodiment or comparative example and the average value was taken. The results are as follows:

[0064]

[0065] The results show that the tensile strength of the electrolytic copper foil prepared in Examples 1-3 of the present invention is increased to above 463.3 MPa and the roughness of the matte surface is reduced to below 1.45 μm by selecting specific additives and appropriate proportions, thereby reducing the thickness of the copper foil and improving the strength of the copper foil.

[0066] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. An electrolyte, characterized in that: Including H2SO4, Cu 2+ , Cl - , sodium N,N-dimethyldithiocarbonylpropane sulfonate, polyvinyl alcohol, hydroxyethyl cellulose, sodium hyaluronate and baicalin.

2. The electrolyte according to claim 1, characterized in that Including H2SO4100-120g / L, Cu 2+ 60-100g / L, Cl - 10-30mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1-5mg / L, polyvinyl alcohol 1-10mg / L, hydroxyethyl cellulose 10-30mg / L, sodium hyaluronate 1-10mg / L and baicalin 0.1-2mg / L.

3. The electrolyte according to claim 1, characterized in that Including H2SO4110g / L, Cu 2+ 80g / L, Cl - 20mg / L, sodium N,N-dimethyldithiocarbonylpropane sulfonate 1.5mg / L, polyvinyl alcohol 5mg / L, hydroxyethyl cellulose 20mg / L, sodium hyaluronate 5mg / L and baicalin 1mg / L.

4. A method for preparing an electrolytic copper foil, characterized in that: The following steps are involved: The electrolyte described in any one of claims 1 to 3 is electrolyzed to obtain an electrolytic copper foil.

5. The preparation method according to claim 4, characterized in that: The following steps are involved: An electrolyte is supplied between an anode plate and a cathode roller, and a voltage is applied between the anode plate and the cathode roller to perform electrolysis, thereby forming the electrolytic copper foil on the surface of the cathode roller.

6. The preparation method according to claim 4, characterized in that: The conditions of the electrolysis are: Electrolysis temperature 50-55℃, bath flow 3-7m 3 / h, current density 40-70A / dm 2 .

7. The preparation method according to claim 6, characterized in that: The conditions of the electrolysis are: Constant current power supply, anode is titanium plated with iridium, cathode is pure titanium, electrolysis temperature is 52°C, plating solution flow rate is 5m 3 / h, current density is 60A / dm 2 , the copper foil thickness is 4μm.

8. The preparation method according to claim 4, characterized in that: The roughness of the cathode roller is 0.13-0.15 Ra.

9. The preparation method according to claim 4, characterized in that: During electrolysis, the rotation speed of the cathode roller is 7-9 m / min.

10. The electrolytic copper foil prepared according to the preparation method according to any one of claims 4 to 9.

11. The electrolytic copper foil according to claim 10, characterized in that: The copper foil has a thickness of 3-5 μm and a tensile strength of more than 450 MPa.

12. The electrolytic copper foil according to claim 11, characterized in that: The copper foil has a thickness of 4 μm and a tensile strength of more than 460 MPa.

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