High-temperature ultrahigh-strength high-elongation copper foil for lithium-ion battery, and production process therefor

Abstract

Disclosed in the present invention are a high-temperature ultrahigh-strength high-elongation copper foil for a lithium-ion battery, and a production process therefor. The production process comprises the following steps: step S1, preparing an electrolyte by dissolving raw copper in a sulfuric acid solution to form a dissolved solution, filtering same to remove impurities and then mixing same with a composite additive to obtain the electrolyte, wherein the composite additive comprises an organic sulfide, gelatin, polyethylene glycol, a nitrogen-containing compound, a polyether compound and Cl-; step S2, preparing a primary copper foil by introducing the electrolyte into an electrolytic cell of a crude foil machine via a pipeline and carrying out electroplating to obtain the primary copper foil; and step S3, subjecting the primary copper foil to a surface passivation treatment, drying and winding to obtain an ultrahigh-strength copper foil for a lithium-ion battery. A high-performance additive is introduced to control the grain refinement and uniform distribution of the copper foil, thereby improving the strength and ductility thereof; the thermal stability and strength of the improved copper foil in a high-temperature environment are maintained, thereby ensuring long-term stable operation of the improved copper foil after high-temperature cyclic charging and discharging of a silicon negative-electrode battery.

Description

A high-temperature, ultra-high-strength, high-elongation lithium battery copper foil and its production process

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202410028131.4 filed on January 9, 2024, entitled “High-temperature, ultra-high-strength, high-elongation lithium battery copper foil and its production process,” and the entire contents of that application are incorporated herein by reference. Technical Field

[0003] The present invention relates to the technical field of copper foil, and in particular to a high-temperature, ultra-high-strength, high-elongation lithium battery copper foil and a production process thereof. Background Art

[0004] With the rapid development of energy transition and electronic devices, the demand for high-performance and safer energy storage systems is growing. Against this backdrop, lithium-ion batteries have become the market's top choice due to their high energy density, long cycle life, and excellent stability. In recent years, to further increase battery energy density, silicon anode materials have attracted research attention due to their much higher theoretical capacity than traditional graphite anode materials.

[0005] However, silicon negative electrode materials undergo huge volume changes (up to 300%) during the charge and discharge process, resulting in material crushing and a decrease in the battery's cycle performance. In addition, the higher operating temperatures that silicon negative electrode lithium batteries usually need to withstand during charge and discharge also place higher performance requirements on the current carrier of copper foil. Therefore, developing a copper foil that can maintain high mechanical properties, excellent elongation and stable chemical properties after high temperatures is of great significance for achieving high-performance silicon negative electrode lithium batteries.

[0006] As a carrier for battery positive and negative electrode materials, copper foil not only serves as a conductor but also must withstand various stresses and high temperatures during battery manufacturing and application. Existing lithium battery copper foil products, after high-temperature baking and high-stress conditions, often exhibit strength and ductility that fail to meet the requirements of silicon anode materials. For example, conventional copper foil is prone to softening, strength loss, and grain growth under high-temperature cycling conditions. This can cause the copper foil to separate from the silicon anode material, thereby affecting battery performance.

[0007] To address these challenges, the present invention proposes a new type of high-temperature, ultra-high-strength, high-elongation copper foil. This foil not only exhibits high strength and elongation at room temperature but also maintains its exceptional mechanical properties and stability even after exposure to high temperatures. The manufacturing process for this copper foil emphasizes raw material selection, preparation technology, and post-processing to ensure both surface and bulk quality.

[0008] The preparation process may include multiple steps, such as using special high-performance additive technology to improve the crystal structure of the copper foil, control grain growth, and maintain excellent thermal stability. Furthermore, it may be possible to optimize the deformation hardening and grain boundary strengthening effects by controlling the annealing process, thereby achieving ultra-high mechanical properties.

[0009] Summary of the Invention

[0010] The purpose of the present invention is to provide a high-temperature, ultra-high-strength and high-elongation electrolytic copper foil and its production method, so as to solve the cracking problems of existing copper foil caused by high temperature, high stress, such as wrinkling during coating, multi-layer winding and expansion and fracture during use in the manufacturing process of lithium-ion and lithium-silicon batteries.

[0011] A first aspect of the present application provides a high-temperature, ultra-high-strength, high-elongation lithium battery copper foil production process, comprising the following steps:

[0012] Step S1, preparing an electrolyte, dissolving raw copper in a sulfuric acid solution to form a solution, filtering and removing impurities, and mixing with a composite additive to obtain an electrolyte; wherein the composite additive includes an organic sulfide, gelatin, polyethylene glycol, a nitrogen-containing compound, a polyether compound, and Cl-;

[0013] Step S2: preparing a primary copper foil product, introducing the electrolyte into the electrolytic cell of the foil production machine through a pipeline, and obtaining the primary copper foil product after electroplating;

[0014] Step S3: The primary copper foil is subjected to surface passivation treatment, dried, and rolled up to obtain an ultra-high-strength lithium battery copper foil.

[0015] Preferably, the raw copper is a copper plate or a copper wire.

[0016] Preferably, the concentration of concentrated sulfuric acid in the electrolyte is 110-130 g / L, the concentration of copper ions is 85-95 g / L, and the temperature of the electrolyte is 48-52°C.

[0017] Preferably, the composite additive comprises 30-100 parts of organic sulfide, 5-15 parts of gelatin, 1-20 parts of polyethylene glycol, 10-20 parts of nitrogen-containing compound, 1-20 parts of polyether compound and 10-40 parts of Cl-;

[0018] The organic sulfide includes one or more selected from the group consisting of 3-mercaptopropane sulfonate, bis-(3-sulfopropyl)-disulfide, bis-(sodium sulfoethyl)-disulfide), 2-methyl sulfoxide, 2-methyl-2-thiazoline, 2-mercaptothiazoline, 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid and alcohol thiopropane sulfonate;

[0019] The weight average molecular weight of the gelatin is 30,000-60,000; the average molecular weight of the polyethylene glycol is 100-10,000;

[0020] The nitrogen-containing compound includes one or more selected from the group consisting of polyethyleneimine, ethoxypolyethyleneimine, N,N,2-methyl-formamide and polyacrylamide;

[0021] The polyether compound includes one or more selected from the group consisting of polyether carboxylate, octylphenol polyoxyethylene ether, polyether polyacrylate and carboxyethyl cellulose.

[0022] Preferably, the Cl- is derived from HCl.

[0023] Preferably, the content of the organic sulfide in the electrolyte is 30mg / L-100mg / L; the content of the gelatin in the electrolyte is 5mg / L-15mg / L; the content of the polyethylene glycol in the electrolyte is 1mg / L-20mg / L; the content of the nitrogen-containing compound in the electrolyte is 10mg / L-20mg / L; the content of the polyether compound in the electrolyte is 1mg / L-20mg / L; the Cl - The content in the electrolyte is 10-40ppm.

[0024] Preferably, the electrolyte flow rate is 40m 3 / h-50m 3 / h, the current density of electroplating is 6000A / m 2 -7000A / m 2 .

[0025] The present invention also provides a high-temperature, ultra-high-strength, high-elongation lithium battery copper foil. The electrolytic copper foil meets the following baking conditions: the high temperature is 150°C for 160 minutes, and the physical property attenuation after baking is less than 5%.

[0026] Preferably, the copper foil satisfies at least two of the following conditions:

[0027] The tensile strength is between 600MPa-700MPa, and the elongation is 4%-6%;

[0028] Preferably, the reasonable structure of the copper foil is such that the average grain size is 0.3-0.4 μm and the twin ratio is 50%-70%.

[0029] Compared with the existing technology, the beneficial effects of the present invention are: introducing high-performance additives to control the grain refinement and uniform distribution of the copper foil, thereby improving the strength and ductility; improving the thermal stability and strength retention of the copper foil in a high-temperature environment, ensuring its long-term stable operation after passing through the high-temperature cycle charge and discharge conditions of a silicon negative electrode battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] FIG1 is an EBSD photograph of the thickness of the copper foil prepared in Example 4;

[0031] FIG2 is an EBSD photograph of the thickness of the copper foil prepared in Comparative Example 2;

[0032] FIG3 is a TEM image of the copper foil prepared in Example 4;

[0033] FIG4 is a schematic diagram illustrating the high temperature baking test procedure.

[0034] In the figure, the double-bright copper foil has an M (matte) side and an S (glossy) side. The S side is the side that is attached to the cathode roller, and the other side is the M side. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0036] The first embodiment of the present application provides an electrolyte additive for electrolytic copper foil, which includes, by weight, 30-100 parts of organic sulfide, 5-15 parts of gelatin, 1-20 parts of polyethylene glycol, 10-20 parts of nitrogen-containing compounds, 1-20 parts of polyether compounds and Cl - 10-40 parts, preferably the electrolyte additives include 40-80 parts of organic sulfide, 5-10 parts of gelatin, 5-15 parts of polyethylene glycol, 10-15 parts of nitrogen-containing compounds, 1-10 parts of polyether compounds and 15-35 parts of Cl-.

[0037] The additive formula includes not only an organic sulfide as a brightener but also a nitrogen-containing compound as a leveler. The combination of these two additives produces a copper foil with extremely high tensile strength and significantly increases its elongation while maintaining surface stability.

[0038] This effect is achieved by rationally combining these two types of additives. The organic sulfide, acting as a brightener, combined with gelatin and nitrogen-containing compound levelers, makes the copper foil's crystal structure smoother and denser, creating a large number of nanocrystalline regions. This crystal structure strengthening effect gives the copper foil higher tensile strength. Simultaneously, the synergistic effect of this formula promotes the formation of large numbers of twins within the copper foil, greatly increasing the proportion and probability of nanotwin formation. The excellent structural interaction between fine crystals and nanotwins not only improves the copper foil's tensile strength but also increases its elongation.

[0039] By applying the theoretical principles of grain refinement and increasing the proportion of nano-twins, this innovative approach breaks through the limitations of traditional formulations. By employing specific additives and optimizing the formulation, the introduction of impurities is reduced. This process generates a large number of nanocrystalline regions, significantly increasing the twin ratio of the copper foil and forming a distinct nano-twin structure.

[0040] This innovation offers numerous advantages. First, it successfully increases the tensile strength of copper foil, giving it improved mechanical properties. Second, through grain refinement and the formation of a nanotwin structure, we achieve a high elongation in the copper foil. This demonstrates that this technology ensures both the strength of the copper foil and its excellent ductility.

[0041] This formulation offers significant advantages over traditional methods. By optimizing the composition and ratio of additives, we successfully reduced the introduction of impurities, thereby improving the purity and quality of the copper foil. Furthermore, we created a large number of nanocrystalline regions, providing the copper foil with more grain boundary strengthening mechanisms, further enhancing its mechanical properties.

[0042] In summary, this innovation, based on the theoretical principles of grain refinement and increased nanotwin ratio, through optimized formulation and the use of specific additives, has achieved a breakthrough in copper foil production. Our technology improves ductility while maintaining the foil's tensile strength, effectively overcoming the limitations of traditional formulations. This innovation is expected to bring significant progress to the field of copper foil production and provide higher-quality copper foil materials for related applications.

[0043] The additives in this solution use organic sulfides as brighteners. The organic divalent sulfides used in the present invention can be selected from commonly used sulfur-containing organic compounds used as brighteners. In some embodiments, the organic sulfides include, but are not limited to, 3-mercaptopropane sulfonate, bis-(3-sulfopropyl) disulfide, 2-mercaptothiazoline, and 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid. Organic sulfides are widely considered to be particle refiners. They can adsorb on the crystal growth surfaces of copper ions, reducing the crystal surface energy of metallic copper, thereby disrupting the orderly growth of the copper lattice and promoting fine grains. The increase in the number of fine grains and the corresponding increase in the number of grain boundaries in the copper foil achieve an increase in material strength (applied to the Hall-Petch relationship), which is one of the physical properties required for ultra-high strength.

[0044] The additive of the present invention uses gelatin as a leveling agent. The gelatin used in the present invention is conventional commercial gelatin. In order to improve the dispersibility of gelatin in the electrolyte, in some embodiments, the weight average molecular weight of collagen is selected to be 30,000-60,000. Gelatin contains a large number of functional groups, such as carboxyl and amino groups, which can form stable complexes with copper ions. During the growth of electrolytic copper foil, these complexes will selectively adsorb on specific crystal growth surfaces, slowing down the deposition rate of copper foil on these surfaces. The selective adsorption of gelatin slows down the reduction reaction of copper ions on the electrode, thereby helping to form smaller and more uniform grains. At the same time, the active groups in its molecules can strongly bind to copper ions and form a complex at the copper deposition interface, blocking or slowing down the regular growth of the copper lattice, thereby prompting the copper foil to form more grain boundaries, which also helps to refine the grains and enhance the strength of the material.

[0045] The additive of the present invention uses polyethylene glycol as a displacement agent. The polyethylene glycol used in the present invention is conventional commercial polyethylene glycol. In some embodiments, the average molecular weight of the polyethylene glycol selected is 6000. The mechanism of action of polyethylene glycol in the copper deposition process is to adsorb on the copper crystal growth surface and form a barrier layer. This barrier layer changes and slows the diffusion rate of copper ions on the crystal surface, slowing the crystal growth rate and causing the shape of the grains to become more equiaxed. In addition, the molecular weight and concentration parameters of the polyethylene glycol have a significant impact on its inhibitory effect: polyethylene glycol with a larger molecular weight has a stronger inhibitory effect on grain growth.

[0046] The additives of the present invention utilize nitrogen-containing compounds as the second leveling agent. The nitrogen compounds used in the present invention can be selected from commonly used nitrogen-containing compounds used as leveling agents, including one or more selected from the group consisting of polyethyleneimine, ethoxypolyethyleneimine, and N,N,2-methyl-formamide. The present invention does not have any particular requirements for the molecular weight of the nitrogen-containing leveling compound. Nitrogen-containing compounds, particularly nitrogen-containing heterocyclic compounds such as pyridine, are generally considered to act as nucleophiles during the deposition process. Their effects may be somewhat similar to those of gelatin and organosulfides, also slowing the deposition reaction and affecting the quality of the deposited layer by forming complexes with copper ions. However, they may have a differential effect on the nucleation mechanism of crystals, sometimes even increasing the density of crystal nuclei and thereby refining the grains.

[0047] The additives of the present invention utilize polyether compounds as the second dislodging agent. In some embodiments, such polyether compounds include, but are not limited to, polyether carboxylates, octylphenol polyoxyethylene ethers, and carboxyethyl cellulose. Polyether compounds stabilize the crystallization process by forming coordination bonds between their oxygen atoms and copper. Their effects may affect the degree of lattice distortion during deposition, thereby affecting the crystal quality and uniformity of the final deposited layer. Polyether compounds may also reduce the internal stress of the copper foil, contributing to the formation of more complete grains and improving ductility.

[0048] The additives of the present invention utilize Cl- as a third leveling agent. In some embodiments, the Cl- is derived from HCl. Chloride ions play a key role in the electrolysis process because they adsorb onto specific surfaces on which crystals grow, influencing their growth behavior and properties. During electrodeposition, chloride ions often alter surface morphology and contribute to grain refinement.

[0049] The above additives can not only act alone, but also interact with each other to shape the properties of copper foil. The interaction between additives usually involves the following points:

[0050] Competitive adsorption: Different additive molecules may compete with each other for spatial positions on copper ions or copper crystal growth surfaces.

[0051] Synergistic effect: One additive may alter the chemical kinetics in a solution, thereby enhancing or inhibiting the efficiency of another additive.

[0052] Chemical interactions: Additives can change their chemical properties by reacting with other factors in solution, for example, through redox reactions or the formation of more complex complexes.

[0053] Organosulfides typically interfere with the growth of copper crystal faces by forming a thin copper sulfide layer, which means they can affect copper deposition through direct interaction with copper ions. When organosulfides coexist with other inhibitors, such as polyethylene glycol or polyether compounds, their effects may be enhanced by interactions between the inhibitors. For example, the adsorption layer provided by polyethylene glycol may reduce the number of crystal faces that the organosulfide needs to cover, making its effect more focused and effective. Gelatin contains functional groups that can form complexes with copper ions, slowing the growth of specific crystal faces and potentially imparting selectivity for copper ion reduction at the electrode. Polyethylene glycol can also adsorb on crystal faces, forming a barrier layer. When used together, they may form a more stable and uniform barrier layer on the crystal faces, effectively restricting the growth direction of copper crystals in certain directions, resulting in finer and more uniform grains. Chloride ions have a unique effect on electrolytic copper foil. Chloride ions increase the conductivity of the solution and can form copper(I) chloride complexes with copper, which facilitates deposition. This property makes it possible to combine chloride ions with other additives, such as chloride ions and organic sulfides, to further refine grain size. The addition of chloride ions may also lead to more selective adsorption of other additives on copper crystal surfaces, as the potential for copper deposition is altered by chloride ions. Certain nitrogen-containing compounds, such as pyridine and its derivatives, may increase the density of crystal nuclei by forming complexes with copper, thereby refining grain size. When used with inhibitors such as polyethers, these compounds may have a complementary effect: the polyethers slow copper reduction and crystal growth, providing a more uniform deposition, while the nitrogen-containing compounds catalyze nucleation at lower coverage, resulting in more nuclei and smaller grains. The combination of these organic sulfide brighteners with gelatin and nitrogen-containing polymer levelers results in a smoother and denser copper foil structure, producing numerous nanocrystalline regions and enhancing grain refinement. This synergistic effect also promotes the formation of numerous twins within the copper foil, significantly increasing the probability and proportion of nanotwin formation. The fine grains and nanotwins interact to improve the copper foil's tensile strength and elongation. The high-temperature performance of copper foil depends on the stability of the microstructure formed during the manufacturing process. Certain additives, such as polyethylene glycol and polyether compounds, can inhibit grain growth at high temperatures, preventing performance degradation during heat treatment. Furthermore, the fine grains provide more interfaces that absorb and release thermal stress, reduce dislocation motion at high temperatures, and improve the material's thermal stability.

[0054] In some embodiments, the weight parts of the organic sulfide include, but are not limited to, 40 parts, 45 parts, 50 parts, 55 parts, 60 parts, 65 parts, 70 parts, 75 parts, or 80 parts.

[0055] In some embodiments, the weight parts of gelatin include, but are not limited to, 5 parts, 8 parts, or 10 parts.

[0056] In some embodiments, the weight parts of polyethylene glycol include but are not limited to 5 parts, 10 parts or 15 parts.

[0057] In some embodiments, the nitrogen-containing compound leveler includes, but is not limited to, 10 parts, 11 parts, 12 parts, 13 parts, 14 parts, or 15 parts.

[0058] In some embodiments, the ether compound includes, but is not limited to, 1 part, 2 parts, 3 parts, 4 parts, 5 parts, 6 parts, 7 parts, 8 parts, 9 parts, or 10 parts.

[0059] In some embodiments, the chloride ion includes, but is not limited to, 15, 20, 25, 30, or 35 parts.

[0060] A second embodiment of the present invention provides a production process for copper foil, the production process comprising:

[0061] Step S1', mixing raw copper, sulfuric acid and an electrolyte additive to form an electrolyte, wherein the electrolyte additive is any one of the electrolyte additives mentioned above;

[0062] Step S2', electrolyzing the raw copper to obtain raw foil;

[0063] Step S3 ′: passivating and drying the original foil to obtain copper foil.

[0064] In some embodiments, the above production process comprises the following steps:

[0065] Step S1, preparing an electrolyte: dissolving raw copper in a sulfuric acid solution to form a solution, filtering and removing impurities, and mixing with a composite additive to obtain an electrolyte; wherein the composite additive includes an organic sulfide, gelatin, polyethylene glycol, a nitrogen-containing compound, a polyether compound, and Cl-;

[0066] Step S2, preparing a primary copper foil: introducing the electrolyte into the electrolytic cell of the foil production machine through a pipeline, and obtaining the primary copper foil after electroplating;

[0067] Step S3: The primary copper foil is subjected to surface passivation treatment, drying, and rolling to obtain a high-temperature, ultra-high-strength, high-elongation lithium battery copper foil.

[0068] The production method of the present invention adopts the above-mentioned specific additives. On the one hand, a large number of nanocrystalline regions are generated during electrolysis, while at the same time the twin ratio of the copper foil is increased and a clear nanotwin structure is generated, thereby ensuring the tensile strength of the copper foil while maintaining a high elongation. On the other hand, a more uniform and reasonable fine grain structure is provided, thereby maintaining the stability of the copper foil at high temperatures.

[0069] In some embodiments of the present invention, the copper ion concentration in the above-mentioned electrolyte is 85g / L-95g / L, the sulfuric acid concentration is 110g / L-130g / L, and the electrolyte temperature is 50°C to improve the stability of electrolysis.

[0070] In some embodiments of the present invention, the electrolyte additives in the electrolyte meet any one or more of the following conditions: the content of the above-mentioned organic sulfide in the electrolyte is 40 mg / L-80 mg / L; the content of the gelatin in the electrolyte is 5 mg / L-10 mg / L; the content of the polyethylene glycol in the electrolyte is 1 mg / L-15 mg / L; the content of the nitrogen-containing compound in the electrolyte is 10 mg / L-15 mg / L; the content of the polyether compound in the electrolyte is 1 mg / L-10 mg / L; the Cl - The content in the electrolyte is 15-35ppm. By controlling the content of each component in the electrolyte within the above range during the electrolysis process, the components can fully cooperate with each other, thereby better improving the tensile strength, elongation and high temperature stability of the copper foil.

[0071] The electrolysis conditions of the present invention can refer to the conventional copper foil electrolysis conditions, that is, the use of the electrolyte additive of the present invention does not require any changes to the conventional electrolysis conditions, so its applicability is relatively wide. In some embodiments, the electrolysis conditions are as follows: the flow rate of the electrolyte is 40m 3 / h-50m 3 / h, the current density of electrolysis is 6000A / m 2 -7000A / m 2 . To promote the full play of the role of electrolyte additives.

[0072] The washing and passivation after electrolysis can refer to the washing process and passivation process commonly used in electrolytic copper foil, which will not be described in detail in the present invention.

[0073] A third embodiment of the present invention provides an electrolytic copper foil, which meets the following baking conditions: a high temperature of 150° C. for 160 min, and a physical property attenuation after baking of less than 5%.

[0074] The third embodiment of the present application further provides an electrolytic copper foil, which meets the following conditions: a tensile strength between 600 MPa and 700 MPa, and an elongation of 4% to 6%.

[0075] The third embodiment of the present application further provides an electrolytic copper foil, wherein the electrolytic copper foil has a reasonable structure with an average grain size of 0.3-0.4 μm and a twin ratio of 50%-70%.

[0076] The electrolytic copper foil of the present invention is a high-temperature, ultra-high-strength, high-elongation copper foil. Its ultra-high tensile strength and good elongation can effectively improve the production efficiency and safety of lithium-ion battery manufacturing. For example, it is suitable for coating, wrinkling, and multi-layer winding processes in the production process of lithium-ion batteries.

[0077] The above tensile strength and elongation are obtained by testing the copper foil at room temperature (about 25°C) using a HY-0230 universal material testing machine manufactured by Shanghai Hengyi Precision Instrument Co., Ltd. in accordance with the test method GB / T29847-2013.

[0078] A fourth embodiment of the present invention provides an electrolytic copper foil produced using any of the aforementioned production methods. The electrolytic copper foil of the present invention is a high-temperature, ultra-high-strength, high-elongation copper foil. Its ultra-high tensile strength and excellent elongation can effectively improve the production efficiency and safety of lithium-ion batteries. For example, this foil is useful in processes such as coating, corrugation, and multi-layer winding in the lithium-ion battery manufacturing process.

[0079] The following examples and comparative examples further illustrate the beneficial effects of the present invention. Where specific techniques or conditions are not specified in the examples, the techniques or conditions described in the literature in the art or in the product instructions were used. Reagents or instruments used without manufacturer specified are commercially available conventional products.

[0080] Example 1

[0081] The raw copper is dissolved in a sulfuric acid solution to form a solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate concentration of 45 mg / L, a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol (average molecular weight of 6,000) concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0082] Example 2

[0083] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a total concentration of 3-mercaptopropane sulfonate (10 mg / L) and bis-(3-sulfopropyl)-disulfide (35 mg / L) of 45 mg / L, a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0084] Example 3

[0085] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 2-mercaptothiazoline concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0086] Example 4

[0087] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0088] Example 5

[0089] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a formyl-1-propane sulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0090] Example 6

[0091] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 15 mg / L (the mass ratio of the two is 2:1), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0092] Example 7

[0093] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 60 mg / L (the mass ratio of the two is 1:3), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0094] Example 8

[0095] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 5 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, the upper liquid flow rate of the electrolyte is 45 m3 / h, and the electrolysis current density is 6500 A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0096] Example 9

[0097] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 10 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0098] Example 10

[0099] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 30,000-40,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0100] Example 11

[0101] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 5 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0102] Example 12

[0103] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 10 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0104] Example 13

[0105] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 15 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0106] Example 14

[0107] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, a polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0108] Example 15

[0109] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an N, N, 2-methyl-formamide concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0110] Example 16

[0111] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 15 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0112] Example 17

[0113] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 35 ppm, and a polyether carboxylate concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0114] Example 18

[0115] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 1 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0116] Example 19

[0117] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a polyether carboxylate concentration of 10 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0118] Example 20

[0119] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether (wherein the n value is 15) concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0120] Example 21

[0121] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxypolyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and a carboxyethyl cellulose concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0122] Example 22

[0123] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 85 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0124] Example 23

[0125] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 110 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0126] Example 24

[0127] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 130 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0128] Example 25

[0129] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 40 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0130] Example 26

[0131] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 50 m 3 / h, the electrolysis current density is 6500A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0132] Example 27

[0133] The raw copper is dissolved in a sulfuric acid solution to form a dissolution solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 6000A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0134] Example 28

[0135] The raw copper is dissolved in a sulfuric acid solution to form a dissolving solution, which is filtered to remove impurities and then mixed with a composite additive to obtain an electrolyte; the obtained electrolyte has a copper ion concentration of 95 g / L, a sulfuric acid concentration of 115 g / L, a 3-mercaptopropane sulfonate and a 3-N, N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid concentration of 45 mg / L (the mass ratio of the two is 1:2), a gelatin (molecular weight of 50,000-60,000) concentration of 8 mg / L, a polyethylene glycol concentration of 8 mg / L, an ethoxylated polyethyleneimine concentration of 10 mg / L, a chloride ion concentration of 25 ppm, and an octylphenol polyoxyethylene ether concentration of 5 mg / L; the electrolysis temperature is 50°C, and the upper liquid flow rate of the electrolyte is 45 m 3 / h, the electrolysis current density is 7000A / m 2 The electrolyte is introduced into the electrolytic cell of the foil machine through a pipe, and the primary copper foil is obtained after electroplating. The primary copper foil is surface passivated, dried and rolled up to obtain ultra-high strength lithium battery copper foil.

[0136] Comparative Example 1

[0137] The same as Example 1, except that 3-mercaptopropane sulfonate was replaced by bis-(sodium sulfoethyl)-disulfide in the electrolyte.

[0138] Comparative Example 2

[0139] The same as Example 1, except that 3-mercaptopropane sulfonate is replaced by 2-methyl sulfoxide in the electrolyte.

[0140] Comparative Example 3

[0141] The same as Example 1, except that 3-mercaptopropane sulfonate is replaced by 2-methyl-2-thiazoline in the electrolyte.

[0142] Comparative Example 4

[0143] The same as Example 1, except that 3-mercaptopropane sulfonate is replaced by alcohol thiopropane sulfonate in the electrolyte.

[0144] Comparative Example 5

[0145] The same as Example 1, except that bis-(sodium sulfoethyl)-disulfide was newly added to the electrolyte.

[0146] Comparative Example 6

[0147] The same as Example 4, except that the concentrations of 3-mercaptopropane sulfonate and 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid in the electrolyte were adjusted to 15 mg / L (the mass ratio of the two was 1:2).

[0148] Comparative Example 7

[0149] The same as Example 4, except that the concentrations of 3-mercaptopropane sulfonate and 3-N,N-dimethylaminodithiocarbamoyl-1-propanesulfonic acid in the electrolyte were adjusted to 60 mg / L.

[0150] Comparative Example 8

[0151] The same as Example 4, except that the concentration of gelatin in the electrolyte was adjusted to 0 mg / L.

[0152] Comparative Example 9

[0153] The same as Example 4, except that the concentration of polyethylene glycol in the electrolyte was adjusted to 20 mg / L.

[0154] Comparative Example 10

[0155] The same as Example 4, except that the ethoxypolyethyleneimine in the electrolyte is replaced by polyacrylamide.

[0156] Comparative Example 11

[0157] The same as Example 4, except that the concentration of ethoxypolyethyleneimine in the electrolyte was adjusted to 5 mg / L.

[0158] Comparative Example 12

[0159] The same as Example 4, except that the concentration of chloride ions in the electrolyte was adjusted to 50 mg / L.

[0160] Comparative Example 13

[0161] The same as Example 4, except that the polyether carboxylate in the electrolyte is replaced by polyether polyacrylate.

[0162] Comparative Example 14

[0163] The same as Example 4, except that the concentration of polyether carboxylate in the electrolyte was adjusted to 15 mg / L.

[0164] Comparative Example 15

[0165] The same as Example 4, except that the concentration of copper ions in the electrolyte was adjusted to 80 g / L.

[0166] Comparative Example 16

[0167] The same as Example 4, except that the concentration of copper ions in the electrolyte was adjusted to 100 g / L.

[0168] Comparative Example 17

[0169] The same as Example 4, except that the concentration of sulfuric acid in the electrolyte was adjusted to 100 g / L.

[0170] Comparative Example 18

[0171] Same as Example 4, except that the electrolyte flow rate was adjusted to 35m 3 / h.

[0172] Comparative Example 19

[0173] Same as Example 4, except that the current density of electrolysis is adjusted to 5000A / m2.

[0174] The microstructure and basic physical properties of the electrolytic copper foils prepared in Examples 1-28 and Comparative Examples 1-19 were tested. The testing methods for the microstructure and basic physical properties are as follows:

[0175] EBSD (Electrode Backscatter Diffraction) Testing: A C-Swift EBSD detector manufactured by Oxford Instruments, UK, was used to observe the microstructure of copper foil samples from various examples and comparative examples. The EBSD images of Example 4 and Comparative Example 6 are shown in Figures 1 and 2. Figure 1 shows a large number of nanocrystalline and twin regions, while Figure 2 shows large overall grains with only a small number of nanocrystalline regions and a relatively small number of twin regions. The TEM image of Example 3, shown in Figure 3, shows a distinct nanoscale twin structure.

[0176] Tensile strength and elongation test: According to the test method GB / T29847-2013, the tensile strength and elongation of the copper foil were tested at room temperature (about 25°C) using a HY-0230 universal material testing machine manufactured by Shanghai Hengyi Precision Instrument Co., Ltd.

[0177] The test results of the microstructure and basic physical properties of the electrolytic copper foils prepared in each embodiment and each comparative example are shown in Table 1.

[0178] Table 1 Performance test results of electrolytic copper foil

[0179] The high-temperature, ultra-high-strength, high-elongation copper foil of the present invention can improve the overall performance of silicon negative electrode lithium batteries and extend their service life, which has far-reaching significance for the development of future energy storage systems.

[0180] At the same time, for conventional lithium batteries, high-temperature ultra-high-strength high-elongation copper foil, with its ultra-high tensile strength and good elongation, can also effectively improve the production efficiency and safety of lithium-ion battery manufacturing. For example, it can be used in coating, wrinkling, and multi-layer winding processes in the production process of lithium-ion batteries.

[0181] Coating wrinkling: During the coating process for the positive and negative electrodes of lithium-ion batteries, the active material needs to be evenly applied to the copper foil. Using ultra-high-strength and high-ductility copper foil can better withstand the mechanical and tensile stresses during the coating process, preventing coating shedding and damage. This helps improve battery consistency and performance stability.

[0182] Multi-layer winding: In lithium-ion battery manufacturing, the positive and negative electrode layers are stacked into a multi-layer structure through winding. Ultra-high-strength and high-ductility copper foil can better maintain its shape and structural stability during the winding process. This helps reduce the contact impedance and internal resistance between the electrode layers, improving battery performance and cycle life.

[0183] Lithium battery copper foil, with its high-temperature ultra-high strength and high ductility, can provide better mechanical properties, stability, and high-temperature resistance in the manufacturing process of lithium-ion batteries. This helps improve battery consistency, cycle life, and safety, and promotes the development and application of lithium-ion battery technology.

[0184] In the copper foil production process, the use of electrolyte additives is crucial. Generally, they include three components: brightener, leveler, and spacer. These additives work synergistically to give the copper foil a fine microstructure and thus excellent mechanical properties.

[0185] Brighteners are a class of sulfur-containing organic compounds whose primary function is to promote the nucleation of copper ions, resulting in fine-grained copper foil and a bright surface. Brighteners form coordination bonds with copper ions or copper crystal faces, regulating the deposition rate and grain formation, ultimately refining the grain size. Levelers promote face-centered growth of copper foil grains. These additives, typically composed of proteins of varying molecular weights, form a protective film during copper foil crystal growth, thereby regulating the growth rate and crystal morphology and enhancing the flatness and regularity of the grains. Levelers can smooth the copper foil surface, improving its finish and surface quality. Distributors improve the dispersion of the electrolyte, ensuring that other additives are evenly and effectively applied to all areas during the copper plating process. Polyether compounds are commonly used as distributing agents. They increase electrolyte fluidity, facilitate rapid transport and uniform distribution of additives, and ensure the full effectiveness of various additives throughout the copper plating process.

[0186] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A production process for high-temperature, ultra-high-strength, and high-elongation lithium-ion battery copper foil, characterized in that, It includes the following steps: Step S1: Prepare the electrolyte. Dissolve raw copper in sulfuric acid solution to form a dissolution solution. After filtering to remove impurities, mix it with a composite additive to obtain the electrolyte. Among them, the composite additive includes organic sulfide, gelatin, polyethylene glycol, nitrogen-containing compounds, polyether compounds, and Cl-; Step S2: Prepare the initial copper foil product. Introduce the electrolyte into the electrolytic cell of the copper foil production machine through a pipeline, and obtain the initial copper foil product after electroplating; Step S3: After performing surface passivation treatment, drying, and winding on the initial copper foil product, obtain an ultra-high-strength lithium battery copper foil.

2. The production process of a high-temperature, ultra-high strength, and high-elongation lithium battery copper foil according to claim 1, characterized in that: The raw copper is copper plate or copper wire.

3. The production process of a high-temperature, ultra-high strength, and high-elongation lithium-ion battery copper foil according to claim 1, characterized in that: In the electrolyte, the concentration of concentrated sulfuric acid is 110 - 130 g / L, the concentration of copper ions is 85 - 95 g / L, and the temperature of the electrolyte is 48 - 52 °C.

4. The production process of a high-temperature, ultra-high strength, and high-elongation lithium-ion copper foil according to claim 1, characterized in that: The composite additive contains 30-100 parts of organic sulfide, 5-15 parts of gelatin, 1-20 parts of polyethylene glycol, 10-20 parts of nitrogen-containing compounds, 1-20 parts of polyether compounds, and 10-40 parts of Cl - 10-40 parts; The organic sulfide is selected from one or more of the group consisting of 3-mercaptopropane sulfonate, bis-(3-sulfopropyl)-disulfide, bis-(sodium sulfonylethyl)-disulfide, 2-methyl sulfoxide, 2-methyl-2-thiazoline, 2-mercapto-thiazoline, 3-N,N-dimethylaminodithiocarbamoyl-1-propane sulfonic acid, and alkanethiol propane sulfonate; The weight-average molecular weight of the gelatin is 30000 - 60000; the average molecular weight of the polyethylene glycol is 100 - 10000; The nitrogen-containing compound is selected from one or more of the group consisting of polyethyleneimine alkane, ethoxypolyethyleneimine, N,N,2-methyl-formamide, and polyacrylamide; The polyether compound is selected from one or more of the group consisting of polyether carboxylic ester, octylphenol polyoxyethylene ether, polyether polyacrylate, and carboxyethyl cellulose; 5. The production process of a high-temperature, ultra-high strength, and high-elongation lithium-ion battery copper foil according to claim 1, characterized in that, The Cl- comes from HCl.

6. The production process of a high-temperature, ultra-high strength, and high-elongation lithium battery copper foil according to claim 4, wherein, The content of the organic sulfide in the electrolyte is 30 mg / L - 100 mg / L; the content of the gelatin in the electrolyte is 5 mg / L - 15 mg / L; the content of the polyethylene glycol in the electrolyte is 1 mg / L - 20 mg / L; the content of the nitrogen-containing compound in the electrolyte is 10 mg / L - 20 mg / L; the content of the polyether compound in the electrolyte is 1 mg / L - 20 mg / L; the Cl - content in the electrolyte is 10 - 40 ppm.

7. The production process of a high-temperature, ultra-high strength, and high-elongation lithium battery copper foil according to claim 4, characterized in that, The electrolyte flow rate is 40 m 3 / h - 50 m 3 / h, and the current density for electroplating is 6000 A / m2 - 7000 A / m2.

8. A high-temperature, ultra-high strength, and high-elongation lithium-ion battery copper foil, characterized in that, The electrolytic copper foil meets the following baking conditions: the high temperature is 150 °C for 160 min, and the physical property attenuation after baking is < 5%.

9. The high-temperature, ultra-high-strength, and high-elongation lithium-ion copper foil according to claim 8, wherein, The copper foil meets the following conditions: The tensile strength is between 600 MPa and 700 MPa, and the elongation is 4% - 6%; 10. A high-temperature, ultra-high-strength, and high-elongation lithium-ion battery copper foil according to claim 8, characterized in that The reasonable structure of the copper foil is that the average grain diameter is 0.3 - 0.4 μm, and the twin crystal ratio is 50% - 70%.

11. An electrolyte additive for electrolytic copper foil, characterized in that, Calculated by weight parts, the composite additive includes 30 - 100 parts of organic sulfide, 5 - 15 parts of gelatin, 1 - 20 parts of polyethylene glycol, 10 - 20 parts of nitrogen-containing compounds, 1 - 20 parts of polyether compounds, and 10 - 40 parts of Cl-.

12. The electrolyte additive according to claim 11, wherein Calculated by weight parts, the electrolyte additive includes: 40 - 80 parts of organic sulfide, 5 - 10 parts of gelatin, 5 - 15 parts of polyethylene glycol, 10 - 15 parts of nitrogen-containing compounds, 1 - 10 parts of polyether compounds, and 15 - 35 parts of Cl-.

13. The electrolyte additive according to claim 11, wherein The electrolyte additive meets any one or more of the following conditions: The organic sulfide is selected from one or more of the group consisting of 3-mercaptopropane sulfonate, bis-(3-sulfopropyl)-disulfide, bis-(sodium sulfonylethyl)-disulfide, 2-methyl sulfoxide, 2-methyl-2-thiazoline, 2-mercapto-thiazoline, 3-N,N-dimethylaminodithiocarbamoyl-1-propane sulfonic acid, and alkanethiol propane sulfonate; preferably, the electrolyte additive includes 1 - 15 parts of 3-mercaptopropane sulfonate; The weight-average molecular weight of the gelatin is 30,000-60,000; The average molecular weight of the polyethylene glycol is 100-10,000; The nitrogen-containing compound includes one or more selected from the group consisting of polyethyleneimine alkane, ethoxypolyethyleneimine, N,N,2-methylformamide, and polyacrylamide; the polyether compound includes one or more selected from the group consisting of polyether carboxylate, octylphenol polyoxyethylene ether, polyether polyacrylate, and carboxyethyl cellulose; The Cl⁻ comes from HCl.

14. A production process of copper foil, characterized in that, The production process includes: Step S1’, mixing raw material copper, sulfuric acid, and an electrolyte additive to form an electrolyte, and the electrolyte additive is the electrolyte additive described in any one of claims 11 to 13; Step S2’, electrolyzing the raw material copper to obtain a raw foil; Step S3’, subjecting the raw foil to surface passivation and drying to obtain a copper foil.

15. The production process according to claim 14, characterized in that, The raw material copper is copper plate or copper wire.

16. The production process according to claim 14 or 15, characterized in that, The electrolyte additive satisfies any one or more of the following conditions: The content of the organic sulfide in the electrolyte additive in the electrolyte is 30 mg / L-100 mg / L; The content of the gelatin in the electrolyte additive in the electrolyte is 5 mg / L-15 mg / L; The content of the polyethylene glycol in the electrolyte additive in the electrolyte is 1 mg / L-20 mg / L; The content of the nitrogen-containing compound in the electrolyte additive in the electrolyte is 10 mg / L-20 mg / L; The content of the polyether compound in the electrolyte additive in the electrolyte is 1 mg / L-20 mg / L; Cl in the electrolyte additive - has a content of 10 - 40 ppm in the electrolyte.

17. The production process according to any one of claims 14 to 16, characterized in that, The concentration of concentrated sulfuric acid in the electrolyte is 110-130 g / L, the copper ion concentration is 85-95 g / L, and the electrolyte temperature is 48-52 °C.

18. The production process according to any one of claims 14 to 17, characterized in that, In the step S2', the electrolyte flow rate is 40 m 3 / h - 50 m 3 / h, and the current density of electroplating is 6000 A / m 2 - 7000 A / m 2 .

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