阅读说明：本技术 一种高模量铜箔的制造方法 (Manufacturing method of high-modulus copper foil ) 是由 杨帅国 江泱 于 2020-11-09 设计创作，主要内容包括：本发明公开了一种高模量铜箔的制造方法,该方法为：将金属铜单质加入含有硫酸的溶铜罐中,将铜溶解制备主电解液,主电解液与特定的添加剂溶液混合得到电解液,打入电解槽；所述特定的添加剂包含A剂、B剂、C剂、D剂及氯离子,所述A剂为含巯基含氮杂环化合物,所述B剂为含醇类有机化合物,所述C剂为含氮天然或合成高分子化合物,所述D剂为含氮含氧类有机化合物和/或含氮含醇类有机化合物；在一定温度及一定的电流密度下进行电解制备原箔；收卷后分切成不同宽幅的成品。本发明的高模量铜箔的制造方法制造的高模量锂电铜箔在弹性形变期间的抗拉强度高,并且铜箔颜色、光亮度稳定易控。(The invention discloses a method for manufacturing a high modulus copper foil, which comprises the following steps: adding a simple substance of metal copper into a copper dissolving tank containing sulfuric acid, dissolving copper to prepare a main electrolyte, mixing the main electrolyte with a specific additive solution to obtain an electrolyte, and pumping the electrolyte into an electrolytic cell; the specific additive comprises an agent A, an agent B, an agent C, an agent D and chloride ions, wherein the agent A is a mercapto-containing nitrogen-containing heterocyclic compound, the agent B is an alcohol-containing organic compound, the agent C is a nitrogen-containing natural or synthetic macromolecular compound, and the agent D is a nitrogen-containing oxygen-containing organic compound and/or a nitrogen-containing alcohol-containing organic compound; electrolyzing at a certain temperature and a certain current density to prepare a raw foil; and cutting into finished products with different widths after rolling. The high-modulus lithium electrolytic copper foil manufactured by the manufacturing method of the high-modulus copper foil is high in tensile strength during elastic deformation, and the color and the brightness of the copper foil are stable and easy to control.)

1. The manufacturing method of the high modulus copper foil is characterized by comprising the following steps:

s1, adding a simple substance of metal copper into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare a main electrolyte, and mixing the main electrolyte with a specific additive solution after multi-stage filtration to obtain an electrolyte; the electrolyte is heat exchanged to a certain temperature by a heat exchanger and is pumped into an electrolytic bath; the specific additive comprises an agent A, an agent B, an agent C, an agent D and chloride ions, wherein the agent A is a mercapto-containing nitrogen-containing heterocyclic compound, the agent B is an alcohol-containing organic compound, the agent C is a nitrogen-containing natural or synthetic macromolecular compound, the agent D is a nitrogen-containing oxygen-containing organic compound and/or a nitrogen-containing alcohol-containing organic compound, and the concentrations of copper ions, sulfuric acid, chloride ions, the agent A, the agent B, the agent C and the agent D in the electrolyte are respectively 60-100 g/L, 80-140 g/L, 20-40 mg/L, 1-50 mg/L, 0.5-20 mg/L, 3-70 mg/L and 5-70 mg/L;

s2, preparing a raw foil by electrolysis at a certain temperature and a certain current density;

s3 rolling and cutting into different width finished products.

2. The method for manufacturing high modulus copper foil according to claim 1, wherein said agent A is one or more of 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-benzimidazole sulfonic acid, 2-mercapto-5-benzimidazole sulfonate, and 2-mercaptobenzothiazole.

3. The method for manufacturing high modulus copper foil according to claim 1, wherein the agent B is one or more of octadiyne diol, butynol and hexynol.

4. The method for manufacturing high modulus copper foil according to claim 1, wherein the agent C is one or more of collagen, polyethyleneimine and polyether ammonia.

5. The method of claim 1, wherein said D agent is a mixture of alcohols containing nitrogen and oxygen.

6. The method for manufacturing high modulus copper foil according to claim 1, wherein the sulfuric acid content in the electrolyte is 80-130 g/L.

7. The method for manufacturing high modulus copper foil according to claim 1, wherein the content of the agent A in the electrolyte is 1-15 mg/L.

8. The method for manufacturing high modulus copper foil according to claim 1, wherein the content of the agent B in the electrolyte is 2-10 mg/L.

9. The method for manufacturing high modulus copper foil according to claim 1, wherein the content of the agent C in the electrolyte is 5-70 mg/L.

10The method of claim 1, wherein the temperature of the electrolyte exchange heat and the temperature of the electrolysis are 50-70 ℃^oC, the current density is 30-100A/dm²。

Technical Field

The invention relates to the technical field of electrolytic copper foil, in particular to a manufacturing method of high-modulus copper foil.

Background

From a technical point of view, thinner lithium electrolytic copper foil means smaller resistance, and thus the energy density and other properties of the battery are also improved. Moreover, the smaller the thickness of the lithium-ion electrolytic copper foil is, the lighter the weight of the corresponding battery is, and the cost of the copper foil raw material can be effectively reduced. Therefore, the use of thinner lithium electrolytic copper foil is in the future.

While the thinning development is carried out, the improvement of the modulus performance is the trend of the future technical development of the lithium electrolytic copper foil. This is because the copper foil needs to withstand a large tensile force in the copper foil coating process, has a high modulus, is rigid, and is not easily bent or broken. In addition, the copper foil is subjected to pressure and tension caused by thermal expansion and contraction after being loaded into a battery, and the copper foil is required to have a high modulus.

The conventional tensile strength measurement adopts the stress in the copper foil stretching process to be divided by the cross sectional area to obtain the tensile strength, but in the process, the copper foil has both elastic deformation and plastic deformation, and the copper foil cannot recover after the plastic deformation, so the tensile strength obtained by the test method is large, and if the plastic deformation plays a large role in the whole tensile process, the risk of the copper foil breaking in the downstream client use process is large.

The high modulus copper foil ensures that the copper foil can resist deformation of the copper foil instantly when bearing large tensile force, and the characteristics represent a new trend of the future copper foil technology development.

In actual production, additives are generally needed to obtain fine and uniform grains in the electrolytic process of the electrolyte, so that the strength of the copper foil is effectively improved. In order to obtain higher modulus and lower profile and surface roughness electrodeposited copper foils, it is necessary to use specific additives, which play different roles in the electrodeposition process. For example, the leveling agent is a positive ion, occupies small salient points on the surface of a titanium roller in the production process of the copper foil and promotes the surface of the copper foil to be more flat; the brightening agent is an additive for promoting the rough surface (M surface) of the copper foil to quickly brighten, and can promote the grain refinement; inhibitors, also called migrating agents, are a class of auxiliary additives that help other functional additives adhere everywhere on the surface of the cathode roll. Different additives are combined according to different proportions, and play a vital role in the strength, hardness and smoothness of the copper foil.

Disclosure of Invention

Aiming at the technical problems in the related art, the invention provides a manufacturing method of a high-modulus copper foil, which can effectively improve the tensile strength of the copper foil in the elastic deformation process.

In order to achieve the technical purpose, the technical scheme of the invention is realized as follows:

a manufacturing method of high modulus copper foil comprises the following steps:

s1, adding a simple substance of metal copper into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare a main electrolyte, and mixing the main electrolyte with a specific additive solution after multi-stage filtration to obtain an electrolyte; the electrolyte is heat exchanged to a certain temperature by a heat exchanger and is pumped into an electrolytic bath; the electrolysis cathode is a seamless drum-type titanium roller, and the anode of the electrolysis bath is a dimensionally stable anode; the specific additive comprises an agent A, an agent B, an agent C, an agent D and chloride ions, wherein the agent A is a mercapto-containing nitrogen-containing heterocyclic compound, the agent B is an alcohol-containing organic compound, the agent C is a nitrogen-containing natural or synthetic macromolecular compound, the agent D is a nitrogen-containing oxygen-containing organic compound and/or a nitrogen-containing alcohol-containing organic compound, and the concentrations of copper ions, sulfuric acid, chloride ions, the agent A, the agent B, the agent C and the agent D in the electrolyte are respectively 60-100 g/L, 80-140 g/L, 20-40 mg/L, 1-50 mg/L, 0.5-20 mg/L, 3-70 mg/L and 5-70 mg/L;

s2, preparing a raw foil by electrolysis at a certain temperature and a certain current density;

s3 rolling and cutting into different width finished products.

Preferably, the agent A is one or more of 2-mercaptobenzoxazole, 2-mercaptobenzimidazole, 2-mercapto-5-benzimidazole sulfonic acid, 2-mercapto-5-benzimidazole sulfonate and 2-mercaptobenzothiazole.

Preferably, the agent B is one or more of subecetylene glycol, butynol and hexynol.

Preferably, the agent C is one or more of collagen, polyethyleneimine and polyether ammonia.

Preferably, the agent D is a mixture of alcohols containing nitrogen and oxygen.

Preferably, the content of sulfuric acid in the electrolyte is 80-130 g/L.

Preferably, the content of the agent A in the electrolyte is 1-15 mg/L.

Preferably, the content of the agent B in the electrolyte is 2-10 mg/L.

Preferably, the content of the agent C in the electrolyte is 5-70 mg/L.

Preferably, the heat exchange temperature and the electrolysis implementation temperature of the electrolyte are 50-70^oC, the current density is 30-100A/dm²。

The invention has the beneficial effects that: according to the manufacturing method of the high-modulus copper foil, the organic additive with specific content is added in the foil generation process, so that the number of initial crystal nuclei, the size of crystal grains and the growth direction of the crystal grains are controlled, and the tensile strength is effectively improved; by thinning crystal grains, the occurrence of crystal grain dislocation is reduced, and the tensile strength of the thinned copper foil is further improved; the agent D forms a certain barrier layer in the electrolyte to prevent the agent B from being rapidly consumed, on the basis, a complex formed by the agent B and chloride ions is adsorbed on the surface of an electrode to hinder copper ion discharge, the nucleation mechanism is gradually changed from continuous nucleation to instantaneous nucleation along with the increase of overpotential, the rapid growth of crystal grains is inhibited, the crystal grains are refined, the original strong preferred orientation crystal grains are inhibited, and the smaller the crystal grains, the higher the material strength is; the agent A has the function of refining grains, and the four agents are matched with each other to ensure that the grains are uniformly refined, so that the copper foil can keep high tensile strength in an elastic deformation range, namely, high modulus is ensured.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all embodiments. All other embodiments that can be derived by one of ordinary skill in the art from the embodiments given herein are intended to be within the scope of the present invention.

The invention firstly defines a high modulus concept calculation mode:

in the copper foil, the tensile strength at a deformation amount of 0.2% is assumed to be equal to Y, and the elastic deformation amount is 0.2% during stretching, so that the modulus E = Y/0.2%.

Example 1

Adding a metal copper simple substance into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare an acidic copper sulfate main electrolyte, performing multi-stage filtration on the main electrolyte, and mixing the main electrolyte with an additive solution to obtain an electrolyte, wherein in the obtained electrolyte, the copper ion concentration is 85 g/L, the acid content is 100 g/L, and the other additives comprise:

2-mercaptobenzimidazole: 2 mg/L;

sodium 3-mercapto-1-propanesulfonate: 30 mg/L;

0.8mg/L of lythidathion propane sodium sulfonate;

collagen (number average molecular weight 4000-;

octadiyne diol (number average molecular weight 500-: 5 mg/L;

chloride ion: 26 mg/L;

the electrolyte is subjected to heat exchange by a heat exchanger to 54 ℃, and is injected into an electrolytic cell. The cathode of the electrolytic cell is a seamless drum-type titanium roller, and the anode is a size limiting anode. At 55A/dm²At the current density of (3), preparing the original foil by electrolysis at 54 ℃, winding and cutting into finished products with different widths.

Example 2

Adding a metal copper simple substance into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare an acidic copper sulfate main electrolyte, performing multi-stage filtration on the main electrolyte, and mixing the main electrolyte with an additive solution to obtain an electrolyte, wherein in the obtained electrolyte, the copper ion concentration is 85 g/L, the acid content is 100 g/L, and the other additives comprise:

2mg/L of mercaptoimidazole propane sodium sulfonate

Sodium polydithio-dipropane sulfonate: 17 mg/L;

5mg/L of octadiyne diol;

collagen (number average molecular weight 3000-;

polyethyleneimine (with the molecular weight of 3000) is 15 mg/L;

chloride ion: 30 mg/L;

the electrolyte is subjected to heat exchange by a heat exchanger to 50 ℃, and is injected into an electrolytic cell. The cathode of the electrolytic cell is a seamless drum-type titanium roller, and the anode is a size limiting anode. At 60A/dm²At the current density of (3), preparing the original foil by electrolysis at 50 ℃, rolling and cutting into finished products with different widths.

Example 3

Adding a metal copper simple substance into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare an acidic copper sulfate main electrolyte, performing multi-stage filtration on the main electrolyte, and mixing the main electrolyte with an additive solution to obtain an electrolyte, wherein in the obtained electrolyte, the copper ion concentration is 85 g/L, the acid content is 100 g/L, and the other additives comprise:

2-mercapto-5-benzimidazolesulfonic acid: 1 mg/L;

sodium polydithio-dipropane sulfonate: 17 mg/L;

butynol 3 mg/L;

collagen (number average molecular weight 3000-;

20 mg/L of polyethyleneimine (the molecular weight of each polyethyleneimine is 3000);

chloride ion: 35 mg/L;

the electrolyte is subjected to heat exchange by a heat exchanger to 50 ℃, and is injected into an electrolytic cell. The cathode of the electrolytic cell is a seamless drum-type titanium roller, and the anode is a size limiting anode. At 60A/dm²At the current density of (3), preparing the original foil by electrolysis at 50 ℃, rolling and cutting into finished products with different widths.

Example 4

Adding a metal copper simple substance into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare an acidic copper sulfate main electrolyte, performing multi-stage filtration on the main electrolyte, and mixing the main electrolyte with an additive solution to obtain an electrolyte, wherein in the obtained electrolyte, the copper ion concentration is 85 g/L, the acid content is 100 g/L, and the other additives comprise:

2-mercaptobenzothiazole: 2 mg/L;

sodium polydithio-dipropane sulfonate: 20 mg/L;

sodium mercaptoimidazolopropane sulfonate: 2 mg/L;

collagen (number average molecular weight 3000-;

5mg/L of octadiyne diol;

20 mg/L of polyethyleneimine (the molecular weight of each polyethyleneimine is 3000);

chloride ion: 35 mg/L;

the electrolyte is subjected to heat exchange by a heat exchanger to 50 ℃, and is injected into an electrolytic cell. The cathode of the electrolytic cell is a seamless drum-type titanium roller, and the anode is a size limiting anode. At 60A/dm²At the current density of (3), preparing the original foil by electrolysis at 50 ℃, rolling and cutting into finished products with different widths.

Example 5

Adding a metal copper simple substance into a copper dissolving tank containing sulfuric acid, blowing high-temperature air by using a screw fan, dissolving copper to prepare an acidic copper sulfate main electrolyte, performing multi-stage filtration on the main electrolyte, and mixing the main electrolyte with an additive solution to obtain an electrolyte, wherein in the obtained electrolyte, the copper ion concentration is 85 g/L, the acid content is 100 g/L, and the other additives comprise:

sodium polydithio-dipropane sulfonate: 20 mg/L;

sodium thiazolophosphone propane sulfonate: 7 mg/L;

collagen (number average molecular weight 3000-;

octadiyne diol: 7 mg/L;

20 mg/L of polyethyleneimine (the molecular weight of each polyethyleneimine is 3000);

chloride ion: 35 mg/L;

the electrolyte is subjected to heat exchange by a heat exchanger to 50 ℃, and is injected into an electrolytic cell. The cathode of the electrolytic cell is a seamless drum-type titanium roller, and the anode is a size limiting anode. At 60A/dm²At the current density of (3), preparing the original foil by electrolysis at 50 ℃, rolling and cutting into finished products with different widths.

Comparative example 1

An electrodeposited copper foil was prepared in the same manner as in example 2, except that the collagen was changed to hydroxyethyl cellulose, and the other parameters were not changed.

Comparative example 2

An electrodeposited copper foil was prepared in the same manner as in example 3, except that collagen was changed to hydroxyethyl cellulose, and the other parameters were not changed.

Comparative example 3

An electrodeposited copper foil was prepared in the same manner as in example 4, except that collagen was changed to hydroxyethyl cellulose, and the other parameters were not changed.

Example 6

Basic physical properties of the electrolytic copper foils prepared in examples 1 to 5 and comparative examples 1 to 3 were measured by the following methods:

and (3) testing the glossiness: the gloss in the M-plane direction of the copper foil was measured under a light incident angle of 60 ℃ according to test method GB/T13891 using WGG60-EJ gloss meter manufactured by Koshida photoelectric instruments Co.

And (3) testing tensile strength and elongation: according to the test method GB/T29847-2013, an HY-0230 universal material tester manufactured by Shanghai Hengyi precision instruments Co., Ltd is used for testing the tensile strength and the elongation of the copper foil under the condition of room temperature (about 25 ℃).

Roughness test (Rz, ten point roughness average): according to the test method GB/T29847-2013, a TR200 roughness meter manufactured by Beijing Time Ruida technology Limited is used for testing the roughness Rz value of the M surface of the copper foil.

The results of basic physical property tests of the electrolytic copper foils prepared in examples 1 to 5 and comparative examples 1 to 3 are shown in Table 1:

TABLE 1 results of performance test of high modulus electrolytic copper foil

As shown in table 1, the physical properties of the copper foil for high modulus lithium ion battery prepared by the technical process provided by the invention, both tensile strength and elongation in elastic deformation can be controlled within a reasonable range. Meanwhile, the roughness and the glossiness of the rough surface can meet the application requirements. As is clear from comparative examples 2 to 4 and comparative examples 1 to 3, the agent A plays a very important role in the adjustment of grain refinement and the agent D in the reduction of crystal dislocations and the improvement of tensile strength.

The manufacturing method of the high-modulus copper foil can manufacture electrolytic copper foils for high-modulus 4.5-micron, 5-micron and 6-micron lithium ion batteries, the tensile strength of the position with 0.2% of elastic deformation at normal temperature can reach more than 350MPa, and the tensile strength is more than 310MPa (the tensile strength at normal temperature is 90%) after heating (150 ℃ and 10 minutes); the elongation at normal temperature is more than or equal to 4 percent, and the elongation after heating (150 ℃, 10 minutes) is more than or equal to 5 percent; roughness Rz of the rough surface is less than or equal to 2.0 μm, and the glossiness is 130-.

The copper foil has elastic deformation and plastic deformation in the stretching process, the tensile strength embodied in the elastic deformation process is more meaningful for manufacturing a downstream battery, because the copper foil has strong toughness and is not easy to break under the condition, the bearing degree of the tensile force and the pressure brought by thermal expansion and cold contraction is stronger, and the modulus is an effective quantitative representation of the tensile strength in the measurement elastic deformation process.

In summary, according to the above technical scheme of the present invention, the method for manufacturing the high modulus copper foil according to the present invention comprises dissolving copper to prepare a main electrolyte, subjecting the main electrolyte to multi-stage filtration, mixing the main electrolyte with an additive solution to obtain an electrolyte, and subjecting the electrolyte to a temperature of 50-60 ℃ and a pressure of 30-100A/dm²The high-modulus lithium electrolytic copper foil manufactured by the invention has high tensile strength during elastic deformation, and the color and the brightness of the copper foil are stable and easy to control. Macromolecular alcohols such as polyethylene glycol are used as additive displacement agents, and are combined with an additive R with displacement function and leveling function, so that the proportion of the brightening agent is increased, crystal grains are finer, dislocation is reduced, and the tensile strength of the copper foil in the elastic deformation process is obviously increased.

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like that fall within the spirit and principle of the present invention are intended to be included therein.