阅读说明：本技术 一种利用密度函理论筛选电解铜箔添加剂的方法 (Method for screening electrolytic copper foil additive by using density function theory ) 是由 唐谊平 陈海波 张建力 陈强 侯广亚 于 2021-06-08 设计创作，主要内容包括：本发明属于电解铜箔领域,为解决电解铜箔添加剂能够非常地改善电解铜箔的力学性能甚至电化学性能,而现有技术无法实现电解铜箔添加剂的高效、有效筛选的问题,公开一种利用密度函理论筛选电解铜箔添加剂的方法,通过计算官能团与金属铜以及阴极辊的特定晶面的吸附能,并根据吸附能的绝对值判定金属铜和阴极辊的特定晶面的吸附性,根据吸附性对官能团进行功能性分类；基于所述功能性分类对添加剂进行筛选。本发明的方法1)能够高效地对大量官能团进行筛选；2)对官能团进行效果分类,归纳官能团能够实现相应的技术效果,对官能团进行分类；3)通过官能团分类能够快速筛选添加剂,以实现对电解铜箔的特定性能强化。(The invention belongs to the field of electrolytic copper foil, and discloses a method for screening an electrolytic copper foil additive by using a density function theory, aiming at solving the problem that the electrolytic copper foil additive can greatly improve the mechanical property and even the electrochemical property of the electrolytic copper foil and the problem that the prior art can not realize the efficient and effective screening of the electrolytic copper foil additive; screening the additive based on the functional classification. The method 1) of the invention can efficiently screen a large number of functional groups; 2) classifying the functional groups according to the effect, inducing the functional groups to realize corresponding technical effects, and classifying the functional groups; 3) the additives can be rapidly screened through functional group classification so as to realize specific performance enhancement of the electrolytic copper foil.)

1. A method for screening an electrolytic copper foil additive by using a density function theory is characterized in that,

the method comprises the following steps: functional groups are functionally classified according to the adsorbability by calculating the adsorbability of the functional groups, the metal copper and the specific crystal face of the cathode roller and judging the adsorbability of the metal copper and the specific crystal face of the cathode roller according to the absolute value of the adsorbability;

screening the additive based on the functional classification.

2. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 1, wherein,

the method specifically comprises the following steps:

1) constructing a unit cell model consisting of a plurality of substrate atoms, and creating a vacuum layer in the adsorption direction of the unit cell model;

2) the bottom layer substrate atoms of the cell model are fixed, the top layer substrate atoms are released, and the functional groups are set to be adsorbed by the top layer of the cell model;

3) performing Hellmann-Feynman force calculation until the calculation result is less than or equal to 0.01 eV/A, and finishing primary screening;

4) based on the screening result, calculating the adsorption energy;

the adsorption energy was calculated by the following formula:

Eads=Etotal-Esubstrate-Eadsorbate；

in the formula: eads is the adsorption energy, Etotal is the total energy of the system after adsorption, Esubstrate is the total energy of the clean substrate before adsorption, Eadsorbate is the energy of the free adsorbent;

5) judging the adsorbability of the unit cell model to the functional group based on the absolute value of the adsorption energy calculation result, classifying the functional group based on the adsorbability and judging the corresponding effect of the functional group;

6) based on the above classification and the corresponding effect, an additive having a specific functional group is selected.

3. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 2, wherein,

step 1), constructing the crystal cell model by using a Vienna Ab-initio Simulation Package;

and used for electron-ion interactions in the form of projective longwave.

4. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 3, wherein,

in the process of constructing the cell model in the step 1), an exchange correlation functional is calculated and obtained by adopting a generalized gradient approximation method of Perdev, Burke and Ernzerhof.

5. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 2, wherein,

the unit cell model constructed in the step 1) takes Cu (111), Cu (220), Cu (200) or Ti (101) as an adsorption surface of a functional group;

the thickness of the vacuum layer is 8-12A.

6. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 2, wherein,

in the process of the step 2), the number of fixed atomic layers at the bottom layer is more than or equal to 3, and the number of relaxed atomic layers at the top layer is more than or equal to 1.

7. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 2, wherein,

step 3) the Hellmann-Feynman force is calculated by Vienna Ab-initio Simulation Package.

8. The method for screening an electrolytic copper foil additive using a density function theory as claimed in claim 2, wherein,

the classification and the corresponding effect of the functional groups in the step 5) comprise the following steps:

a) the I-type functional group is selectively adsorbed on a crystal face of a copper crystal grain to inhibit the oriented growth of the copper foil;

b) the II-type functional group is selectively adsorbed on certain crystal faces of copper crystal grains to promote the oriented growth of the copper foil;

c) the III-type functional group is uniformly adsorbed on the surface of each crystal face of the copper crystal grain, and the crystal grain is not oriented, so that the effect of refining the crystal grain is enhanced in an auxiliary manner;

d) the IV functional groups are adsorbed on the surface of the cathode roller, so that the grain refinement of the copper grains is realized.

Technical Field

The invention belongs to the field of electrolytic copper foil, and particularly relates to a method for screening an additive of the electrolytic copper foil by using a density function theory.

Background

The electrolytic copper foil is a metal foil, is an important raw material in the electronic and electrical industries, and is mainly used for manufacturing copper clad laminates, printed circuit boards, lithium batteries and the like. With the miniaturization of electronic devices, the continuous development of printed circuit surface mounting technology and the continuous increase of the requirements of multilayer printed circuit boards, the ultrathin high-performance electrolytic copper foil with few defects, fine grains, lower roughness, high strength, good ductility and wide application range is realized.

The quality of the electrolytic copper foil is mainly determined by the organization structure, the impurity content and the like of the electrolytic copper foil, and if the high-quality copper foil is obtained, the current density, the temperature of the electrolyte, the liquid inlet mode and the liquid inlet amount of an electrolytic bath, additives and the like must be strictly controlled. The additive is the most main control factor, and practice proves that adding a proper amount of additive is an effective measure for obtaining high-quality electrolytic copper foil with compact structure, smooth surface and low impurity content.

Known from a fine grain strengthening mechanism, the strength and toughness of the material can be improved after the internal crystal grains of the metal are refined, namely the mechanical property of the electrolytic copper foil can be expected to be improved by obtaining the refined crystal grains. The most common and feasible method of grain refinement is to use suitable additives. However, the types of additives are very diverse and the functions of different types of additives are different. How to efficiently screen out proper additives is a difficulty of project research.

Disclosure of Invention

The invention provides a method for screening an electrolytic copper foil additive by using a density function theory, which aims to solve the problems that the mechanical property and even the electrochemical property of an electrolytic copper foil can be greatly improved, and the high-efficiency and effective screening of the electrolytic copper foil additive cannot be realized in the prior art.

The invention aims to:

firstly, the screening of the electrolytic copper foil additive can be effectively realized;

secondly, classifying the performance functionality of the screened additives;

and thirdly, the proper additives can be conveniently selected according to classification for strengthening different properties of the electrolytic copper foil.

In order to achieve the purpose, the invention adopts the following technical scheme.

A method for screening an electrolytic copper foil additive by using a density function theory,

the method comprises the following steps: functional groups are functionally classified according to the adsorbability by calculating the adsorbability of the functional groups, the metal copper and the specific crystal face of the cathode roller and judging the adsorbability of the metal copper and the specific crystal face of the cathode roller according to the absolute value of the adsorbability; screening the additive based on the functional classification.

As a preference, the first and second liquid crystal compositions are,

the method specifically comprises the following steps:

1) constructing a unit cell model consisting of a plurality of substrate atoms, and creating a vacuum layer in the adsorption direction of the unit cell model;

2) the bottom layer substrate atoms of the cell model are fixed, the top layer substrate atoms are released, and the functional groups are set to be adsorbed by the top layer of the cell model;

3) computing Hellmann-Feynman force until the computed resultFinishing primary screening;

4) based on the screening result, calculating the adsorption energy;

the adsorption energy was calculated by the following formula:

Eads＝Etotal-Esubstrate-Eadsorbate；

in the formula: eads is the adsorption energy, Etotal is the total energy of the system after adsorption, Esubstrate is the total energy of the clean substrate before adsorption, Eadsorbate is the energy of the free adsorbent;

5) judging the adsorbability of the unit cell model to the functional group based on the absolute value of the adsorption energy calculation result, classifying the functional group based on the adsorbability and judging the corresponding effect of the functional group;

6) based on the above classification and the corresponding effect, an additive having a specific functional group is selected.

The invention utilizes a Density Functional Theory (DFT) method to calculate the adsorption energy of typical functional groups to the surfaces of metallic copper and titanium (cathode roller), screens out a batch of functional groups, reduces the selection range of additives through the combination of the functional groups and achieves the aim of high-efficiency screening.

In the production process of the electrolytic copper foil, a proper additive can be preferentially adsorbed on a specific crystal face of a crystal so as to inhibit texture. The metal atoms are adsorbed on the cathode surface. When present in the solution, the additive will significantly affect the deposition process of the metal ions, mainly the adsorption process of the metal. Many additives can be adsorbed on the surface of the cathode to form a compact adsorption layer, and the discharge process of metal ions or the surface diffusion of metal adsorption atoms is hindered, so that a coating with fine grains is obtained. The various effects of the additives on the coating are due to their diffusion depletion, adsorption polarization, and possible contamination of the coating with reduction products. Therefore, the amount of adsorption capacity of the additive on the cathode surface and the plating surface can be considered as the key to determine the function thereof.

The strength of the adsorption capacity of the additive on the cathode surface and the coating surface is expressed as the absolute value of the adsorption capacity, and the larger the absolute value of the adsorption capacity is, the stronger the adsorption capacity of the functional group on the crystal face is. And (3) screening functional groups and common adsorption surfaces in common additives, and calculating the adsorption energy through a DFT theory so as to judge the strength of the adsorption capacity of the additives.

As a preference, the first and second liquid crystal compositions are,

step 1), constructing the crystal cell model by using a Vienna Ab-initio Simulation Package;

and used for electron-ion interactions in the form of projective longwave.

As a preference, the first and second liquid crystal compositions are,

in the process of constructing the cell model in the step 1), an exchange correlation functional is calculated and obtained by adopting a generalized gradient approximation method of Perdev, Burke and Ernzerhof.

As a preference, the first and second liquid crystal compositions are,

the unit cell model constructed in the step 1) is Cu (111), Cu (220) and Cu (2)00) Or Ti (101) as an adsorption surface of the functional group; the thickness of the vacuum layer is

Copper is a face-centered cubic structure, and after electrolytic deposition, crystal planes (111), (220) and (200) are low-energy planes and are easy to expose, while the (101) crystal plane is the most common crystal plane for substrate titanium. Therefore, Cu (111), Cu (220), Cu (200), Ti (101), etc. are selected as the adsorption surface of the functional group.

As a preference, the first and second liquid crystal compositions are,

in the process of the step 2), the number of fixed atomic layers at the bottom layer is more than or equal to 3, and the number of relaxed atomic layers at the top layer is more than or equal to 1.

As a preference, the first and second liquid crystal compositions are,

step 3) the Hellmann-Feynman force is calculated by Vienna Ab-initio Simulation Package.

As a preference, the first and second liquid crystal compositions are,

the classification and the corresponding effect of the functional groups in the step 5) comprise the following steps:

a) the I-type functional group is selectively adsorbed on a crystal face of a copper crystal grain to inhibit the oriented growth of the copper foil;

b) the II-type functional group is selectively adsorbed on certain crystal faces of copper crystal grains to promote the oriented growth of the copper foil;

c) the III-type functional group is uniformly adsorbed on the surface of each crystal face of the copper crystal grain, and the crystal grain is not oriented, so that the effect of refining the crystal grain is enhanced in an auxiliary manner;

d) the IV functional groups are adsorbed on the surface of the cathode roller, so that the grain refinement of the copper grains is realized.

The common additives for the electrolytic copper plating are finished. The comparison shows that the functional groups are ether bond, carbonyl, sulfonyl, amino, hydroxyl, sulfydryl, alkyl, quaternary ammonium salt, carbonyl, imidazole, pyrrole and the like, and can be used as DFT calculation objects.

The invention has the beneficial effects that:

1) a large number of functional groups can be efficiently screened;

2) classifying the functional groups according to the effect, inducing the functional groups to realize corresponding technical effects, and classifying the functional groups;

3) the additives can be rapidly screened through functional group classification so as to realize specific performance enhancement of the electrolytic copper foil.

Drawings

FIG. 1 is a schematic representation of selected functional groups, unit cell models, and combinations thereof, in accordance with an embodiment of the present invention.

Fig. 2 is a plain SEM image of the electrodeposited copper foil under the action of the carbonyl diphenylamine additive in proof test 1.

FIG. 3 is a SEM image of the matte side of the electrodeposited copper foil with the carbonyl diphenylamine additive of proof test 1.

FIG. 4 is a plain SEM image of electrodeposited copper foil with methanesulfonyl chloride additive in validation test 2.

FIG. 5 is a SEM image of the matte side of the electrodeposited copper foil with methanesulfonyl chloride additive in validation test 2.

Fig. 6 is a STEM profile of the blank control group.

FIG. 7 is a STEM representation of the shiny side of electrodeposited copper foil made with a 0.1mg/L concentration of carbonyldiphenylamine additive.

FIG. 8 is a STEM representation of the polished surface of electrolytic copper foil prepared with 0.5mg/L concentration of methanesulfonyl chloride additive.

Detailed Description

The invention is described in further detail below with reference to specific embodiments and the attached drawing figures. Those skilled in the art will be able to implement the invention based on these teachings. Moreover, the embodiments of the present invention described in the following description are generally only some embodiments of the present invention, and not all embodiments. Therefore, all other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort shall fall within the protection scope of the present invention.

In the description of the present invention, it is to be understood that the terms "thickness", "upper", "lower", "horizontal", "top", "bottom", "inner", "outer", "circumferential", and the like, indicate orientations and positional relationships based on those shown in the drawings, and are used merely for convenience in describing the present invention and for simplicity in description, and do not indicate or imply that the device or element being referred to must have a particular orientation, be constructed and operated in a particular orientation, and thus, should not be construed as limiting the present invention. In the description of the present invention, "a plurality" means at least two, e.g., two, three, etc., and "several" means one or more unless specifically limited otherwise.

Unless otherwise specified, the raw materials used in the examples of the present invention are all commercially available or available to those skilled in the art; unless otherwise specified, the methods used in the examples of the present invention are all those known to those skilled in the art.

Examples

A method for screening an electrolytic copper foil additive by using a density function theory,

the method comprises the following steps:

1) the method comprises the steps of constructing a cell model consisting of a plurality of substrate atoms by using a Vienna Ab-initio Simulation Package, calculating and obtaining an exchange correlation functional by adopting a generalized gradient approximation method of PBE (Perew, Burke and Ernzerhof) during construction, using the substrate atoms in the constructed cell model for electron-ion interaction in a projection growth (PAW) wave form, and creating the cell model in the adsorption direction (Z-axis direction) of the cell modelA vacuum layer of (2);

in this embodiment, the functional groups selected in this step are shown in fig. 1(a), the constructed unit cell model is shown in fig. 1(b), the adsorption planes of the constructed unit cell functional groups are, from left to right, Cu (111), Cu (200), Cu (220), and Ti (101), and the functional groups subjected to calculation screening are, from left to right, an ether bond, a carbonyl group, a sulfonyl group, an amino group, a hydroxyl group, and a thiol group in this order;

subsequently, the unit cell model and the functional group are subjected to Simulation calculation, and the calculation process is realized through a Vienna Ab-initio Simulation Package;

2) in the calculation process, the substrate atoms of the bottom layer 3 layer of the cell model are fixed, the substrate atoms of the top layer 1 layer are released, and a functional group is set to be adsorbed by the top layer of the cell model, and subsequent calculation is performed as shown in fig. 1(c) after adsorption;

3) computing Hellmann-Feynman force until the computed resultFinishing primary screening;

both the selected functional group and the unit cell model satisfy the computational requirements;

4) based on the screening result, calculating the adsorption energy;

the adsorption energy was calculated by the following formula:

Eads＝Etotal-Esubstrate-Eadsorbate；

in the formula: eads is the adsorption energy, Etotal is the total energy of the system after adsorption, Esubstrate is the total energy of the clean substrate before adsorption, Eadsorbate is the energy of the free adsorbent;

the results of the adsorption energy calculation are shown in the following table:

functional group	Ether bond	Carbonyl radical	Sulfonyl radical	Amino group	Hydroxy radical	Mercapto group
							Cu(111)	-4.049	-1.170	-5.106	-3.429	-3.811	-3.132
Cu(200)	-1.718	-0.995	-4.940	-3.532	-3.710	-3.182
							Cu(220)	-1.763	-1.056	-5.062	-3.688	-4.034	-3.179
Ti(101)	-4.211	-3.104	-8.797	-4.912	-6.256	-4.102

5) Judging the adsorbability of the unit cell model to the functional group based on the absolute value of the adsorption energy calculation result, classifying the functional group based on the adsorbability and judging the corresponding effect of the functional group;

the absolute values of the adsorption energies are shown in the following table:

functional group	Ether bond	Carbonyl radical	Sulfonyl radical	Amino group	Hydroxy radical	Mercapto group
							Cu(111)	4.049	1.170	5.106	3.429	3.811	3.132
Cu(200)	1.718	0.995	4.940	3.532	3.710	3.182
							Cu(220)	1.763	1.056	5.062	3.688	4.034	3.179
Ti(101)	4.211	3.104	8.797	4.912	6.256	4.102

Classifying the functional groups based on the absolute values and judging the effects corresponding to the accumulated functional groups, as shown in the following table;

6) screening out additives with specific functional groups based on the classification and the corresponding effect;

such as:

additives containing ether linkages with group I functional groups include, but are not limited to: diethyl ether, n-butyl ether, tetrahydrofuran, dioxane, etc.;

additives containing a group I functional hydroxyl group include, but are not limited to: polyethylene glycol, polyvinyl alcohol, and the like;

additives containing a group II functional carbonyl group include, but are not limited to: carbonyldiphenylamine, formamide, ethyl acetate, and the like;

additives containing a sulfonyl group of a class II functional group include, but are not limited to: p-toluenesulfonyl chloride, sodium polydithio-dipropanesulfonate, and the like;

additives containing a mercapto group with a group III functionality include, but are not limited to: ethanethiol, ethanedithiol, and the like;

additives containing amino groups of group IV functional groups include, but are not limited to: polyethyleneimine, polyvinylamine, and the like;

and the sulfonyl group and the hydroxyl group have the effects of I-type functional groups or II-type functional groups and IV-type functional groups, so that polyethylene glycol, polyvinyl alcohol and the like, and paratoluensulfonyl chloride, sodium polydithio-dipropyl sulfonate and the like also belong to the additives containing IV-type functional groups.

The additives screened by the above method were subjected to the following verification test. The verification tests were all compared with a blank control group, which was prepared in the same manner except that no additive was added.

Verification test 1

The additive containing the II-type functional group is selected to inhibit the growth of Cu (100) and Cu (200) crystal planes of copper crystal grains and the preferred orientation growth of a Cu (220) crystal plane, thereby improving the texture coefficient of the electrolytic copper foil.

The basic formula for preparing the electrolytic copper foil in the verification test is as follows: 0.5mol/L of copper sulfate and 1.0mol/L of sulfuric acid.

Selecting additives of carbonyl diphenylamine, formamide and ethyl acetate, adding the additives into a basic formula, regulating and controlling the concentration of the additives, and carrying out tensile mechanical property test and Cu (220) crystal face texture coefficient measurement and calculation on the prepared electrolytic copper foil, wherein the results are shown in the following table.

As can be seen from the table, the tensile strength is greatly improved under four concentrations of the additive, namely the carbonyl diphenylamine, the lowest tensile strength can reach more than 430MPa, the highest tensile strength is reached under the concentration of 0.1mg/L, the highest tensile strength is 476.6MPa, and the elongation is 5.9 percent; the additives of formamide and ethyl acetate are improved and can reach about 430MPa under a certain concentration, but the strengthening effect is weaker than that of the carbonyl diphenylamine. Therefore, better results can be obtained, and the requirements of lithium battery customers on high-strength copper foil are completely met. Meanwhile, it can be found that the selected additives can generate corresponding effects indeed, the texture coefficient of the Cu (220) crystal face is increased, but the concentration needs to be regulated and selected according to different additives.

Moreover, the results of the verification test on the table above show that the additive containing the II-type functional group can realize a good modification effect by improving the texture coefficient of the Cu (220) crystal face, and remarkably improve the mechanical property of the electrolytic copper foil.

Wherein, the electrolytic copper foil prepared by the carbonyl diphenylamine additive with the concentration of 0.1mg/L is characterized, as shown in figures 2 and 3, the figures 2 and 3 are scales of 50 μm, the figure 2 is a smooth surface SEM characterization figure, and the figure 3 is a rough surface SEM characterization figure. It can be seen from fig. 3 that the microstructure of the matte side thereof was very significantly flattened by the additive without significant large grain structure in the planar direction, indicating that Cu (111) and Cu (200) were significantly suppressed.

Verification test 2

After the DFT theory is adopted for calculation, the electrolytic copper foil is continuously tested according to the result, and according to the research result, the following can be considered: the tensile strength of the electrolytic copper foil can be obviously improved by refining crystal grains and strengthening texture. The copper foil is subjected to typical epitaxial growth in the initial electrolytic deposition stage, and the copper crystal growing in contact with the cathode titanium roller obviously influences the nucleation and growth of subsequent crystals, so that the primary copper crystal on the smooth surface is further refined, and an important effect is generated on the grain refinement of the whole copper foil. Therefore, on the basis of the verification test 1, additives containing IV-type functional groups, such as methanesulfonyl chloride, p-toluenesulfonyl chloride and dansyl chloride, are respectively added. 4 possible concentration values of the additive are selected, the raw foil test is respectively carried out, and the mechanical property test is shown in the following table.

As can be seen from the table, the additive methanesulfonyl chloride reaches the maximum tensile strength of 534.8MPa and the elongation of 7.4% at the concentration of 0.3 mg/L; the additives of tosyl chloride and dansyl chloride are improved, which shows that the additives have better enhancing effect.

Further, the electrolytic copper foil prepared by the methanesulfonyl chloride additive at a concentration of 0.5mg/L was characterized as shown in FIGS. 4 and 5, in which FIGS. 4 and 5 are both on a scale of 50 μm, FIG. 4 is a plain SEM characterization chart, and FIG. 5 is a matte SEM characterization chart. As can be seen from FIGS. 4 and 5, under the action of the methanesulfonyl chloride additive, both the glossy surface and the matte surface were very flat, without significant defects, and had a bright appearance.

In addition, STEM characterization was performed on the plain finish of the blank control, the plain finish of the electrolytic copper foil prepared with the carbonyl diphenylamine additive at a concentration of 0.1mg/L, and the plain finish of the electrolytic copper foil prepared with the methanesulfonyl chloride additive at a concentration of 0.5 mg/L. The characterization results are shown in fig. 6, 7 and 8, in which fig. 6 is a blank control, fig. 7 is an electrolytic copper foil prepared by the carbonyl diphenylamine additive, and fig. 8 is an electrolytic copper foil prepared by the methanesulfonyl chloride additive. It can be seen from the figure that as the mechanical properties of the electrodeposited copper foil are improved, the dislocation density and substructure inside the actual crystal grains are gradually increased, as expected from the change in texture coefficients. With the enhancement of texture, namely crystal face preferred orientation, the internal stress of the electrolytic copper foil is continuously increased. When the internal stress of the copper foil is released, a large amount of dislocation and substructure are generated inside crystal grains. The dislocation strengthening theory shows that the dislocation and the substructure increase the deformation resistance, thereby improving the mechanical property of the copper foil.

Through the verification test 1 and the verification test 2, it can be obviously seen that the additive obtained by screening by the method can be very effectively used for strengthening and modifying the electrolytic copper foil, the texture characteristic of the electrolytic copper foil is improved, and the mechanical property of the electrolytic copper foil is further obviously improved.