TWM583133U - Lithium-ion secondary battery and electrolytic copper foil - Google Patents

Abstract

The present invention discloses a lithium ion secondary battery and an electrolytic copper foil. The electrolytic copper foil includes a green foil layer having a first surface and a second surface opposite the first surface. Wherein, in the X-ray diffraction spectrum of the first surface, the diffraction peak intensity I (200) of the (200) crystal plane of the first surface and the diffraction peak intensity I of the (111) crystal plane of the first surface I (111 The ratio is between 0.5 and 2.0. In the X-ray diffraction spectrum of the second surface, the diffraction peak intensity I (200) of the (200) crystal plane of the second surface and the diffraction peak intensity I (111) of the (111) crystal plane of the second surface The ratio is also between 0.5 and 2.0.

Description

Lithium ion secondary battery and electrolytic copper foil

The present invention relates to a lithium ion secondary battery and an electrolytic copper foil, and more particularly to an electrolytic copper foil having a high elongation.

Electrolytic copper foil can be used to manufacture various products such as a negative electrode body of a lithium ion secondary battery. In general, in the process of manufacturing an electrolytic copper foil, an electrolytic copper foil having a large-sized crystal grainy crystal structure can be produced by using a high concentration of an additive in an electrolytic solution. Such electrolytic copper foils generally have a high elongation. In the X-ray diffraction spectrum (XRD spectrum) of such an electrolytic copper foil, the diffraction peak intensity I (111) of the (111) crystal plane is high, and the diffraction peak of the (200) crystal plane and the (220) crystal plane is high. The intensities I (200) and I (220) are lower, and the ratio of I (200) to I (111) is usually less than 0.5.

Although an electrolytic copper foil having a high elongation can be produced by using a high concentration of an additive in an electrolytic solution, it also causes a problem that high production cost and process conditions are not easily controlled.

Therefore, the creator feels the above problems, and studies and cooperates with the application of scientific principles to propose a novel that can effectively improve the above problems.

The technical problem to be solved by the present invention is that, in the prior art, it is necessary to use a high concentration of an additive to produce a problem of having a high elongation copper foil, and to provide a lithium ion secondary battery and an electrolytic copper foil.

In order to solve the above technical problem, one of the technical solutions adopted by the present invention is to provide an electrolytic copper foil comprising: a primary foil layer having a first surface and a second surface opposite to the first surface; a diffraction peak intensity I (200) of the (200) crystal plane of the first surface and a diffraction of the (111) crystal plane of the first surface in an X-ray diffraction spectrum of the first surface The ratio of the peak intensity I(111) is between 0.5 and 2.0; wherein, in the X-ray diffraction spectrum of the second surface, the diffraction peak intensity I of the (200) crystal plane of the second surface The ratio of the diffraction peak intensity I(111) of the (111) to the (111) crystal plane of the second surface is also between 0.5 and 2.0.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a method for manufacturing an electrolytic copper foil, comprising: preparing a copper electrolyte, wherein the copper electrolyte contains at least one additive, and The total weight of the copper electrolyte is based on, the concentration of at least one of the additives is not more than 12 parts per million by weight (ppm); and performing a plating step comprising: electrolyzing the copper electrolyte to form a raw foil layer; Wherein the green foil layer has a first surface and a second surface relative to the first surface; wherein, in the X-ray diffraction spectrum of the first surface, the first surface (200) a ratio of a diffraction peak intensity I (200) of the crystal face to a diffraction peak intensity I (111) of the (111) crystal face of the first surface is between 0.5 and 2.0; wherein, in the In the X-ray diffraction spectrum of the two surfaces, the diffraction peak intensity I (200) of the (200) crystal plane of the second surface and the diffraction peak intensity I of the (111) crystal plane of the second surface I (111 The ratio is also between 0.5 and 2.0.

In order to solve the above technical problem, another technical solution adopted by the present invention is to provide a lithium ion secondary battery, comprising an electrolytic cell having an accommodating space for accommodating an electrolyte; In the accommodating space of the electrolytic cell; a negative electrode disposed in the accommodating space of the electrolytic cell and spaced apart from the positive electrode; wherein the negative electrode comprises an electrolytic copper foil, And the electrolytic copper foil has a first surface and a second surface opposite to the first surface; and a separator disposed between the positive electrode and the negative electrode; wherein, the electrolytic copper foil The X-ray diffraction spectrum of the first surface, the diffraction peak intensity I (200) of the (200) crystal plane of the first surface and the diffraction peak of the (111) crystal plane of the first surface The ratio of the intensity I (111) is between 0.5 and 2.0; wherein, in the X-ray diffraction spectrum of the second surface of the electrolytic copper foil, the (200) crystal face of the second surface a diffraction peak intensity I (200) and a diffraction peak intensity I (111) of the (111) crystal plane of the second surface The ratio is also between 0.5 and 2.0.

One of the beneficial effects of the present invention is that the electrolytic copper foil provided by the present invention, the manufacturing method thereof, and the lithium ion secondary battery can pass "in the X-ray diffraction spectrum of the first surface of the electrolytic copper foil" The ratio of the diffraction peak intensity I (200) of the (200) crystal plane of the first surface to the diffraction peak intensity I (111) of the (111) crystal plane of the first surface is between 0.5 and 2.0 Between the X-ray diffraction spectrum of the second surface of the electrolytic copper foil, the diffraction peak intensity I (200) of the (200) crystal plane of the second surface and the second surface The ratio of the diffraction peak intensity I(111) of the (111) crystal face is also between 0.5 and 2.0", and "the copper electrolyte contains at least one additive, and the total weight of the copper electrolyte is The technical solution of the concentration of at least one of the additives is not more than 12 parts per million (ppm), so that the electrolytic copper foil has high elongation, and can reduce the production cost and improvement of the electrolytic copper foil. Production stability of electrolytic copper foil.

In order to further understand the features and technical contents of this creation, please refer to the following detailed description and drawings of the present invention. However, the drawings are provided for reference and description only, and are not intended to limit the creation.

The embodiments disclosed in the present disclosure are described below by way of specific embodiments, and those skilled in the art can understand the advantages and effects of the present invention from the contents disclosed in the present specification. The present invention can be implemented or applied in various other specific embodiments. The details of the present specification can also be variously modified and changed without departing from the concept of the present invention. In addition, the drawings of the present creation are only for the purpose of simple illustration, and are not stated in advance according to the actual size. The following embodiments will further explain the related technical content of the present invention, but the disclosure is not intended to limit the scope of protection of the present invention.

It should be understood that, although the terms "first", "second", "third", and the like may be used herein to describe various elements or signals, these elements or signals are not limited by these terms. These terms are primarily used to distinguish one element from another, or one signal and another. In addition, the term "or" as used herein may include a combination of any one or more of the associated listed items, depending on the actual situation.

[electrolytic copper foil]

Please refer to FIG. 1. FIG. 1 is a schematic side view of an electrolytic copper foil according to an embodiment of the present invention. The electrolytic copper foil 110 of the present embodiment is preferably applicable to a lithium ion secondary battery (also referred to as a lithium ion secondary battery), and can be used as a negative electrode body of a lithium ion secondary battery. The electrolytic copper foil 110 of the present embodiment comprises a green foil layer 111, a first oxidation resistant layer 112a, and a second oxidation resistant layer 112b. The raw foil layer 111 has a first surface S1 and a second surface S2 opposite to the first surface S1, and the first oxidation resistant layer 112a is disposed on the first surface S1. The second oxidation resistant treatment layer 112b is disposed on the second surface S2. That is, the first anti-oxidation treatment layer 112a and the second anti-oxidation treatment layer 112b are respectively disposed on two opposite surfaces of the green foil layer 111, thereby improving the oxidation resistance of the electrolytic copper foil 110. However, this creation is not limited to this. For example, in an embodiment not shown in the present creation, the electrolytic copper foil 110 may also include only the raw foil layer 111, and does not include the first oxidation resistant layer 112a and the second oxidation resistant layer. 112b.

Further, in the present embodiment, the distance between the first surface S1 and the second surface S2 may be defined as the thickness of the electrolytic copper foil 110 (including the thickness of the green foil layer 111 and the oxidation resistant treatment layers 112a and 112b). thickness). In order to enable the electrolytic copper foil 110 to be applied to a lithium ion secondary battery, the thickness of the electrolytic copper foil 110 is preferably between 2 micrometers (μm) and 20 micrometers (μm), but the creation is not limited. herein.

Referring to FIG. 2, FIG. 2 is an X-ray diffraction spectrum of an electrolytic copper foil according to an embodiment of the present invention. For example, FIG. 2 shows that in the X-ray diffraction spectrum of the two surfaces (S surface and M surface) of the electrolytic copper foil 110, the (111) crystal plane is at a diffraction angle (2θ) of 43.0°±1.0°. The diffraction peak intensity and the diffraction peak intensity of the (200) crystal plane at a diffraction angle (2θ) of 50.5 ° ± 1.0 °, and the known intensity ratio I (200) / I (111) is between about 0.5 to about Within the scope of 2.0.

More specifically, in the present embodiment, in the X-ray diffraction spectrum of the first surface S1 of the electrolytic copper foil 110, the diffraction peak intensity I of the (200) crystal plane of the first surface S1 ( 200) The ratio of the diffraction peak intensity I(111) to the (111) crystal plane of the first surface S1 is between 0.5 and 2.0. Furthermore, in the X-ray diffraction spectrum of the second surface S2 of the electrolytic copper foil 110, the diffraction peak intensity I (200) of the (200) crystal plane of the second surface S2 is opposite to the second surface The ratio of the diffraction peak intensity I(111) of the (111) crystal plane of S2 is also between 0.5 and 2.0.

That is, the ratio of I (200) to I (111) in the X-ray diffraction spectrum of the first surface S1 or the second surface S2 is not less than 0.5 and not more than 2.0.

Referring to FIG. 1, the first anti-oxidation treatment layer 112a and the second anti-oxidation treatment layer 112b each have a thickness of not more than 50 nanometers (nm). Furthermore, the first oxidation resistant layer 112a and the second oxidation resistant layer 112b each comprise a non-copper metal element. Wherein, the first anti-oxidation treatment layer 112a and the second anti-oxidation treatment layer 112b all contain a total weight content of 1 part per million (Parts per million) based on the total weight of the electrolytic copper foil 110. , ppm) to 1,000 parts by weight of the non-copper metal element, and the non-copper metal element is selected from the group consisting of chromium (Cr), zinc (Zn), nickel (Ni), molybdenum (Mo), At least one element selected from the group consisting of manganese (Mn), phosphorus (P), and combinations thereof.

According to the design of the structure and material of the above-mentioned electrolytic copper foil 110, the electrolytic copper foil 110 can have good tensile strength and ductility. More specifically, the electrolytic copper foil 110 has a temperature of 28 kgf/mm ² to a room temperature environment (e.g., 20 ° C to 30 ° C) without any heat treatment step. A tensile strength of 40 kgf/mm ² and an elongation of not less than 7% (also referred to as elongation). Furthermore, after the electrolytic copper foil 110 is subjected to a heat treatment step, the electrolytic copper foil 110 has a tensile strength of 25 kgf/mm ² to 35 kgf/mm ² and an elongation of not less than 9.5%. . Wherein, the heat treatment step comprises baking the electrolytic copper foil at a temperature of 130 ° C to 250 ° C for 0.5 hours to 1.5 hours. Preferably, the heat treatment step comprises baking the electrolytic copper foil at a temperature of 180 ° C for 1.0 hour.

That is, in the present embodiment, the tensile strength of the electrolytic copper foil 110 after the heat treatment step can be substantially maintained from 65% to 95% of the tensile strength before the heat treatment step, and The elongation of the electrolytic copper foil 110 after the heat treatment step is approximately 100% to 140% of the elongation before the heat treatment step.

Referring to FIG. 3, FIG. 3 is a view of a focused ion beam (Focused Ion Beam, FIB for short) image of an electrolytic copper foil according to an embodiment of the present invention. Wherein, the electrolytic copper foil 110 has a plurality of crystal grains (not numbered), and the grain size of the plurality of crystal grains before the heat treatment step is between 20 nm (nm) and 45 nm. Between (nm), and preferably between 21.5 nm and 40.5 nm, the creation is not limited thereto. Wherein, the above grain size is calculated by full width at half maximum (FWHM) of X-ray diffraction (XRD) spectrum.

Furthermore, in the present embodiment, the grain size of the plurality of crystal grains of the electrolytic copper foil 110 after the heat treatment step is 90% of the grain size of the plurality of crystal grains before the heat treatment step is not performed. It is between 130%, and preferably between 95% and 120%. That is, according to the design of the above-described electrolytic copper foil 110, the electrolytic copper foil 110 can maintain a bulk crystal structure having large-sized crystal grains regardless of whether or not the heat treatment step is performed, thereby having high elongation.

Referring to FIG. 2, in the X-ray diffraction (XRD) spectrum of the electrolytic copper foil of the embodiment, the ratio of I(200) to I(111) of the two surfaces of the electrolytic copper foil is between Between 0.5 and 2.0. That is, the diffraction peak intensity I (200) of the (200) crystal plane of the electrolytic copper foil is a diffraction peak intensity I (111) close to the (111) crystal plane. Furthermore, as can be seen from FIG. 2, the diffraction peak intensity I (200) of the (200) crystal plane of the electrolytic copper foil and the diffraction peak intensity I (111) of the (111) crystal plane are much higher than The diffraction peak intensity I (220) of the (220) crystal plane.

Further, since the crystal orientation of the electrodeposited copper foil 110 of the present embodiment is mainly a (200) crystal plane and a (111) crystal plane, the crystal grains of the electrodeposited copper foil 110 are likely to slip. The phenomenon of shifting allows the electrolytic copper foil 110 to have a high elongation. From another point of view, since the crystal structure of the electrolytic copper foil 110 of the present embodiment is a bulk crystal structure, the electrolytic copper foil 110 can have a high elongation.

[Method of Manufacturing Electrolytic Copper Foil]

The above is a description of the structure and material of the electrolytic copper foil 110 of the present embodiment, and a method of manufacturing the electrolytic copper foil 110 will be described in detail below based on the embodiment of the present invention.

This embodiment discloses a method of manufacturing the electrolytic copper foil 110. The manufacturing method of the electrolytic copper foil 110 includes step S110, step S120, and step S130. It should be noted that the order of the steps and the actual operation mode of the present embodiment may be adjusted according to requirements, and is not limited to the embodiment.

Step S110 is to prepare a copper electrolyte, wherein the copper electrolyte contains at least one additive, and the concentration of at least one of the additives is not more than 12 parts per million based on the total weight of the copper electrolyte. (ppm).

More specifically, in the present embodiment, in addition to the above additives, the composition of the copper electrolytic solution further contains copper ions, chloride ions, and sulfuric acid. Wherein, in the copper electrolyte, the concentration of the copper ions is preferably from 30 g/L to 90 g/L, and more preferably from 50 g/L to 70 g/L; the concentration of the sulfuric acid is preferably It is from 50 g/L to 140 g/L, and more preferably from 70 g/L to 120 g/L; the concentration of the chloride ion is preferably from 10 ppm to 50 ppm, and more preferably from 10 ppm to 30 ppm. Further, in the present embodiment, the source of the copper ions is copper sulfate, and the source of the chloride ions is hydrochloric acid, but the creation is not limited thereto.

Further, in this embodiment, at least one of the additives comprises a first additive, a second additive, and a third additive.

The first additive is a gelatin and is preferably an industrial grade electroplated gelatin. Wherein, in the copper electrolyte, the concentration of the gelatin is preferably not more than 5 ppm. Further, the gelatin preferably has a weight average molecular weight of from 1,000 to 5,000, and more preferably from 2,000 to 4,000. Further, the gelatin may be, for example, at least one selected from the group consisting of pig gum, bovine gum, or fish gelatin. In the embodiment, the first additive is preferably pig rubber, but the creation is not limited thereto.

The second additive is a sulfonic acid or a metal salt thereof containing a sulfur atom compound. Among them, in the copper electrolytic solution, the concentration of the sulfonic acid or a metal salt thereof containing the sulfur atom compound is preferably not more than 2 ppm. Further, the sulfonic acid or a metal salt thereof containing the sulfur atom compound may be, for example, selected from the group consisting of bis-(3-sulfopropyl)-disulfide disodium salt. , SPS), 3-mercapto-1-propanesulfonic acid (MPS), 3-(N,N-dimethylaminethiomethane)-thiopropane sulfonate sodium salt (3-(N,N-dimethylthiocarbamoyl)-thiopropanesulfonate sodium salt, DPS), 3-[(amino-iminomethyl)thio]-1-propanesulfonic acid sodium salt (3-[(amino-iminomethyl)) Thio]-1-propanesulfonate sodium salt, UPS), o-ethyldithiocarbonate-S-(3-sulfopropyl)-ester sodium Salt, OPX), 3-(benzothiazolyl-2-mercapto)-propyl-sulfonic acid sodium salt (ZPS), ethylene dithio Ethylenedithiodipropylsulfonic acid sodium salt, thioglycolic acid, thiophosphoric acid-o-ethyl-bis-(ω-sulfopropyl) disodium salt (thiophosphoric acid-o) -ethyl-bis-(ω-sulfopropyl)ester disodium salt) And at least one of the group consisting of thiophosphoric acid-tris-(ω-sulfopropylester ester trisodium salt). In the present embodiment, the second additive is preferably 3-mercapto-1-propanesulfonic acid (MPS), but the creation is not limited thereto.

The third additive is a nonionic water soluble polymer. Wherein, in the copper electrolyte, the concentration of the nonionic water-soluble polymer is preferably not more than 5 ppm. Further, the nonionic water-soluble polymer may be, for example, selected from the group consisting of hydroxyethyl cellulose (HEC), polyethylene (poly(ethylene oxide), PEG), polyglycerin, and carboxylate. Carboxymethylcellulose, nonylphenol polyglycol ether, octane diol-bis-(polyalkylene glycol ether), xin Otanal polyalkylene glycol ether, oleic acid polyglycol ether, polyethylene propylene glycol, polyethylene glycol dimethyl ether , polyoxypropylene glycol, polyvinyl alcohol, ß-naphthol polyglycol ether, stearic acid polyglycol ether, and stearyl alcohol At least one group consisting of stearyl alcohol polyglycol ether. In the present embodiment, the third additive is preferably hydroxyethyl cellulose (HEC), but the creation is not limited thereto.

Wherein, the sum of the concentrations of the first additive, the second additive, and the third additive is preferably not more than 12 ppm, and more preferably not more than 10 ppm, based on the total weight of the copper electrolytic solution. Further, the above various additives are mainly used for improving the surface glossiness of the electrolytic copper foil 110 and reducing the surface roughness of the electrolytic copper foil 110.

Step S120 is to perform a plating step, comprising: electrolyzing the copper electrolyte to form a green foil layer 111.

More specifically, the electroplating step comprises: heating the copper electrolyte to a predetermined temperature, wherein the predetermined temperature is between 50 ° C and 60 ° C, and more preferably between 50 ° C and 55 Between ° C; then, a current density of 30 A/dm ² to 80 A/dm ² is formed between the electrode plate and the rotating electrode drum in the copper electrolyte at the predetermined temperature. Electroplating is performed to form the green foil layer 111 on the rotating plating wheel.

Wherein, as described in the above embodiment, the green foil layer 111 has a first surface S1 and a second surface S2 opposite to the first surface S1. Wherein, in the X-ray diffraction spectrum of the first surface S1, a diffraction peak intensity I (200) of the (200) crystal plane of the first surface S1 and (111) crystallization of the first surface S1 The ratio of the diffraction peak intensity I(111) of the face is between 0.5 and 2.0. Wherein, in the X-ray diffraction spectrum of the second surface S2, a diffraction peak intensity I (200) of the (200) crystal plane of the second surface S2 and (111) crystallization of the second surface S2 The ratio of the diffraction peak intensity I(111) of the face is also between 0.5 and 2.0.

The electrolytic copper foil 110 of the present embodiment is based on the above process conditions, including: selection of the type of the additive, selection of the molecular weight of the gelatin, adjustment of the concentration of the additive (not more than 12 ppm), adjustment of the concentration of the chloride ion, and temperature adjustment of the copper electrolyte. The crystal orientation is mainly composed of a (200) crystal plane and a (111) crystal plane, so that a phenomenon of slippage between the plurality of crystal grains of the electrolytic copper foil 110 is likely to occur, so that the electrolytic copper foil 110 can Has a high elongation. That is to say, the electrolytic copper foil 110 of the present embodiment can still have good elongation characteristics under the use of a low additive concentration by the above-described process conditions, thereby greatly reducing the use cost of the additive and improving the production. The problem of poor control of the process.

Further, in the present embodiment, the first surface S1 of the green foil layer 111 is further defined as a glossy surface SS (also referred to as S surface, S surface) that is in contact with the rotating plating wheel during electroplating, and The second surface of the green foil layer 111 is further defined as another glossy surface MS (also referred to as M surface) opposite the glossy surface SS.

Wherein, in the X-ray diffraction spectrum of the S-plane, a diffraction peak intensity I (200) of the (200) crystal plane of the S-plane and a diffraction peak intensity of the (111) crystal plane of the S-plane The ratio of I(111) is defined as a first diffraction peak intensity ratio. And in the X-ray diffraction spectrum of the M-plane, the diffraction peak intensity I (200) of the (200) crystal plane of the M plane and the diffraction peak intensity I of the (111) crystal plane of the M plane The ratio of (111) is defined as a second diffraction peak intensity ratio.

In the embodiment, the first diffraction peak intensity ratio is preferably smaller than the second diffraction peak intensity ratio, and the first diffraction peak intensity ratio is preferably the same as the first The absolute value of the difference between the two diffraction peak intensity ratios is not less than 0.01 and not more than 0.30. For the related content, please refer to the analysis in Table 1 and Table 2 below.

Step S130 is to perform an anti-oxidation treatment step, comprising: forming a first anti-oxidation treatment layer 112a on the first surface S1 of the green foil layer 111, and forming on the second surface S2 of the green foil layer 111. A second oxidation resistant layer 112b is formed such that the green foil layer 111, the first oxidation resistant layer 112a, and the second oxidation resistant layer 112b are collectively formed as an electrolytic copper foil 110. Wherein, the first anti-oxidation treatment layer 112a and the second anti-oxidation treatment layer 112b all contain a total weight content of 1 part per million (Parts per million) based on the total weight of the electrolytic copper foil 110. , ppm) to a non-copper metal element of 1,000 parts by weight, and the non-copper metal element is selected from the group consisting of chromium, zinc, nickel, molybdenum, manganese, phosphorus, and combinations thereof. At least one element.

More specifically, the anti-oxidation treatment step includes: treating the green foil with a treatment solution containing the non-copper metal element (eg, at least one of chromium, zinc, nickel, molybdenum, manganese, and phosphorus) The layer 111 is subjected to a plating treatment or an impregnation treatment such that the first anti-oxidation treatment layer 112a is formed on the first surface S1 of the green foil layer 111, and the second surface S2 of the green foil layer 111 is formed thereon. The second oxidation-resistant layer 112b, whereby the oxidation resistance of the electrolytic copper foil 110 is effectively improved. Wherein, the above treatment solution may, for example, contain 0.1 g/L to 5.0 g/L of chromium oxide, zinc sulfate, nickel sulfate, sodium molybdate, sulfuric acid, or phosphoric acid. Further, the current density of the above plating treatment may be, for example, between 0.3 A/dm ² and 3.0 A/dm ² . The soaking time of the above impregnation treatment may be, for example, between 2 seconds and 20 seconds, but the present creation is not limited thereto.

[Experimental data test]

Hereinafter, the contents of the present creation will be described in detail with reference to the exemplary examples 1 to 5 and the comparative examples 1 to 3. However, the following examples are merely examples to help understand the present creation, and the scope of the present creation is not limited to these embodiments.

An electric current is generated between the electrode plates in the electrolyte and the rotating plating wheel to form a green foil layer on the rotating plating wheel. The copper electrolyte contains 50 g/L to 70 g/L of copper ions and 70 g/L to 120 g/L of sulfuric acid. The current density of the plating is between 30 A/dm ² and 80 A/dm ² . Process conditions such as copper electrolyte temperature, chloride ion concentration, gelatin weight average molecular weight, gelatin concentration (first additive concentration), MPS concentration (second additive concentration), and HEC concentration (third additive concentration) for electroplating are as follows Table 1 shows. The green foil layer is formed by electroplating by immersion, an oxidation resistant treatment layer is formed by an oxidation treatment, and then the electrolytic copper foil is dried.

It is worth mentioning that in the first to the fifth examples, the gelatin concentration (first additive concentration), the MPS concentration (second additive concentration), and the HEC concentration (the first) are based on the total weight of the copper electrolyte. The sum of the three additive concentrations) is not more than 12 ppm, and more preferably not more than 10 ppm.

[Table 1 Process Parameter Conditions of Exemplary and Comparative Examples]  Item Copper electrolyte temperature (°C) Chloride ion concentration (ppm) Gelatin Weight average molecular weight Gelatin concentration (ppm) MPS concentration (ppm) HEC concentration (ppm) Example 150302,0004.00.94.0 Example 253302,0004.00.54.0 Example 353134 , 0003.00.23.0 Example 453134,0001.00.50.5 Example 553134,0001.00.42.0 Comparative Example 153304, 00070.010.020.0 Comparative Example 253134, 00070.010.020.0 Comparative Example 35830> 10,0004.01.04.0

From the electrolytic copper foils obtained in Exemplary Examples 1 to 5 and Comparative Examples 1 to 3, the first surface of the electrolytic copper foil (that is, the glossy surface in contact with the rotary plating wheel, referred to as the S surface) and the second surface were measured (referred to as the S surface). That is, the other characteristic surface of the other glossy surface opposite to the S surface, referred to as M surface) before and after a heat treatment step, includes: XRD analysis value, tensile strength, and elongation, and testing The results are shown in Table 2 below. The heat treatment step refers to baking the electrolytic copper foil at a temperature of 180 ° C for 1.0 hour.

XRD measurement: X-ray diffraction (XRD) spectra of S and M faces of the electrodeposited copper foils obtained in Exemplary Examples 1 to 5 and Comparative Examples 1 to 3 (for example, FIG. 2) were measured. Thereby, the ratio of I(200)/I(111) and the ratio of (I220)/(I111) can be calculated. More specifically, the XRD measurement of the electrolytic copper foil was performed by Bruker's D2 Phaser machine, and X-ray diffraction was performed by a diffraction angle of 20 to 95 [target: The interval between copper K α1, 2θ: 0.01°, and the scan rate of 2θ: 0.13 degrees/minute second] obtains an XRD pattern having peaks corresponding to n crystal faces (for example, where there is a corresponding crystal face (111), ( XRD patterns of peaks of 200), (220) and (311). The XRD diffraction (light) intensity [I(hkl)] of each of the crystal faces (hkl) was obtained from the XRD pattern. Thereby, the ratio of I(200)/I(111) and the ratio of (I220)/(I111) can be calculated.

Tensile strength and elongation measurement: The electrolytic copper foils obtained in Examples 1 to 5 and Comparative Examples 1 to 3 were treated. These electrolytic copper foils can be subjected to tensile tests of these tensile specimens according to the IPC-TM-650 2.4.18B standard at a crosshead velocity of 50.8 mm/min. The maximum load of the measured tensile strength is called room temperature tensile strength (RTS), and the elongation at break is called room temperature elongation (REL). The room temperature herein represents 20 ° C to 30 ° C. Next, the same electrolytic copper foil for measuring the tensile strength at room temperature and the elongation was subjected to heat treatment at 180 ° C for 1 hour, and then the tensile strength and elongation were measured in the same manner at room temperature. The measured tensile strength and elongation are referred to as thermal post tensile strength (ATS) and post thermal extensibility (AEL).

[Table 2 Test Experimental Data of Exemplary and Comparative Examples]  Example 1 Example 2 Example 3 Example 4 Example 5 Comparative Example 1 Comparative Example 2 Comparative Example 3I (200) / I (111) S surface heat treatment before 0.580.670.520.860.830.250.240.25M face before heat treatment 0.720. After 810.581.080.930.250.240.20S surface heat treatment 0.710.710.601.170.900.290.260.32M surface heat treatment 0.750.790.671.290.950.240.230.30I(220)/I(111)S surface heat treatment before 0.150.150.130.150.140.140.330 .15M surface heat treatment before 0.160.160.140.150.140.170.190.21S surface heat treatment 0.180.150.140.180.140.200.300.16M surface heat treatment 0.140.140.160.160.160.130.270.170.20RTS (kgf/mm  2)  32.233.733.534.234.432.431.839.4REL(%)8.39.78.97.99.25.85.13.0ATS(kgf/mm  2)  31.130.729.629.730.832.229.029.6AEL(%)15.011.910.19.713.49.28.94.0

As can be seen from Table 2, the electrolytic copper foils of Examples 1 to 5 have an I(200)/I(111) ratio analyzed by XRD, which falls substantially in the range of 0.5 to 2.0, more precisely, It falls within the range of 0.52 to 1.29. In the electrolytic copper foils of Comparative Examples 1 to 3, the I(200)/I(111) ratios by XRD analysis were all less than 0.5, more precisely, falling within the range of 0.2 to 0.33. That is, the I(200)/I(111) ratio of the electrolytic copper foils of Exemplary Examples 1 to 5 was I(200)/I(111) compared with the electrolytic copper foils of Comparative Examples 1 to 3. The ratio is much higher.

From another point of view, the electrolytic copper foils of Examples 1 to 5 have a ratio of I(200)/I(111) of the S surface to I(200)/I of the M plane before heat treatment. 111) The ratio is low. Further, in the electrolytic copper foils of Exemplary Examples 1 to 5, after the heat treatment, the I (200) / I (111) ratio of the S surface is compared with the I (200) / I (111) ratio of the M surface thereof. It is also low, but the difference between the two has a tendency to shrink.

Furthermore, in Examples 1 to 5, the I(200)/I(111) ratio before heat treatment is mostly lower than the I (200) after heat treatment, whether it is the S surface or the M surface. /I(111) ratio. That is to say, the heat treatment will cause the I(200)/I(111) ratio of the electrolytic copper foil to be slightly increased.

More specifically, in the electrolytic copper foils of Exemplary Examples 1 to 5, the I (200) / I (111) ratio of the S surface of the first embodiment is in the range of 0.52 to 0.86, and after the heat treatment, The I(200)/I(111) ratio of the S plane thereof falls within the range of 0.60 to 1.17. In the electrolytic copper foils of Exemplary Examples 1 to 5, the I(200)/I(111) ratio of the M-plane before the heat treatment is in the range of 0.58 to 1.08, and after the heat treatment, the S-plane I The (200)/I(111) ratio falls within the range of 0.67 to 1.29.

Wherein, the I(200)/I(111) ratio of the S surface (glossy surface) may be defined as a first diffraction peak intensity ratio, and the above M surface (the other gloss surface) is I(200)/I ( 111) The ratio can be defined as a second diffraction peak intensity ratio. That is, the electrolytic copper foils of Examples 1 to 5 have a first diffraction peak intensity ratio smaller than the second diffraction peak intensity ratio before or after the heat treatment, and the first The absolute value of the difference between the diffraction peak intensity ratio and the second diffraction peak intensity ratio is not less than 0.01, and is not more than 0.30.

Further, as can be seen from Table 2, the electrolytic copper foils of Exemplary Examples 1 to 5 have a room temperature tensile strength (RTS) of approximately 28 kgf/mm ² to 40 kgf/mm ² before heat treatment. Within the range, and its room temperature elongation (REL) is not less than 7%.

The electrolytic copper foils of Exemplary Examples 1 to 5 have a heat tensile strength (ATS) of approximately 25 kgf/mm ² to 35 kgf/mm ² after heat treatment, and their post-heat elongation (AEL) are not less than 9.5%. It is worth mentioning that the elongation of the electrolytic copper foils of Exemplary Examples 1 to 5 was significantly higher than that of Comparative Examples 1 to 3 before and after the heat treatment. It is apparent that the electrolytic copper foils of Exemplary Examples 1 to 5 have a better elongation performance.

Further, the additive concentrations (including gelatin concentration, MPS concentration, and HEC concentration) of Examples 1 to 5 were much lower than the additive concentrations of Comparative Example 1 and Comparative Example 2. The reason why the electrolytic copper foil having high REL and AEL can be produced under the condition of using low additive concentration is the above various process conditions (including: selection of additives, molecular weight selection of gelatin, concentration adjustment of chloride ions, and The temperature adjustment of the copper electrolyte is properly matched to each other.

Thereby, the crystal orientation of the electrodeposited copper foils of the example 1 to the example 5 is mainly a (200) crystal plane and a (111) crystal plane, and thus can have a high elongation. That is, the electrolytic copper foils of Exemplary Examples 1 to 5 can still have good elongation characteristics by using the above-described process conditions, and at a low additive concentration, thereby greatly reducing the use cost of the additive, and Improved the problem of poor control of the process during production.

In addition, the importance of gelatin molecular weight selection can be seen from Comparative Example 3 of Table 2. More specifically, although the process conditions of Comparative Example 3 (including: copper electrolyte temperature, chloride ion concentration, and concentration of various additives) were close to the process conditions of Example 1. However, since the gelatin molecular weight selected in Comparative Example 3 was too large (greater than 10,000), the electrolytic peak copper obtained by the process conditions of Comparative Example 3 had a diffraction peak intensity I (200) of the (200) crystal face which could not be obtained. The diffraction peak intensity I (111) of the (111) crystal plane, and its I (200) / I (111) ratio is less than 0.5, so the electrolytic copper foil of Comparative Example 3 is inferior to the example in the performance of REL and AEL. 1 performance in REL and AEL.

[Lithium ion secondary battery]

Referring to FIG. 4 and FIG. 5, FIG. 4 is a schematic side view of the negative electrode of the present embodiment, and FIG. 5 is a schematic view of the lithium ion secondary battery of the present embodiment. In the present embodiment, the above-described electrolytic copper foil 110 can be applied to a lithium ion secondary battery E (which may also be referred to as a lithium ion secondary battery), and can be used as a material of the negative electrode 100 of the lithium ion secondary battery E.

The lithium ion secondary battery E may be an energy storage type, a power type, or an energy type storage battery, and may be applied as a battery for a vehicle. The above-described vehicle battery can be applied to an electric vehicle, an electric bus, a hybrid electric vehicle, etc., but the creation is not limited thereto.

Referring to FIG. 5, the lithium ion secondary battery E includes a negative electrode 100 (or an anode), a positive electrode 200 (or a cathode), a separator 300, and an electrolytic cell 400. The electrolytic cell 400 has an accommodating space R for accommodating an electrolyte (not shown). The anode 100 is disposed in the accommodating space R of the electrolytic cell 400. The positive electrode 200 is also disposed in the accommodating space R of the electrolytic cell 400 and is disposed at a distance from the negative electrode 100. The separator 300 is disposed between the anode 100 and the cathode 200. Wherein, when the electrolytic cell 400 houses the electrolyte, the electrolyte can provide an environment for lithium ions to move between the positive electrode 200 and the negative electrode 100, and the separator 300 can electrically insulate the positive electrode 200 and the negative electrode 100, By avoiding a short circuit inside the lithium ion secondary battery E.

The positive electrode 200 of the lithium ion secondary battery E includes an aluminum foil and a positive electrode active material (not shown) coated on the aluminum foil, but the creation is not limited thereto.

Referring to FIG. 4, the negative electrode 100 of the lithium ion secondary battery E includes the electrolytic copper foil 110, a first active material layer 120a, and a second active material layer 120b. The first active material layer 120a and the second active material layer 120b are respectively disposed on the two opposite surfaces of the electrolytic copper foil 110. More specifically, the first active material layer 120a is disposed on a surface of the first oxidation resistant layer 112a away from the raw foil layer 111, and the second active material layer 120b is disposed on the second antioxidant. The surface of the treatment layer 112b is away from the surface of the green foil layer 111.

In the present embodiment, FIGS. 4 and 5 are exemplified by the fact that the first active material layer 120a and the second active material layer 120b are respectively disposed on both surfaces of the electrolytic copper foil 110, but This creation is not limited to this. In the embodiment not shown in the present creation, the anode 100 of the lithium ion secondary battery E may include only one of the first active material layer 120a and the second active material layer 120b as its active material layer.

The first active material layer 120a and the second active material layer 120b may include at least one active material as a negative electrode active material, and the active material is selected from the group consisting of carbon, germanium, containing antimony, tin, lithium, zinc, magnesium, At least one of a group consisting of a metal of cadmium, tellurium, nickel, or iron, an alloy of the metal, an oxide of the metal, and a composition of the metal and carbon.

[Advantageous Effects of Embodiments]

One of the advantageous effects of the present invention is that the electrolytic copper foil 110 provided by the present invention, the method of manufacturing the same, and the lithium ion secondary battery E can pass the "X-ray on the first surface S1 of the electrolytic copper foil 110". The ratio of the diffraction peak intensity I (200) of the (200) crystal plane of the first surface S1 to the diffraction peak intensity I (111) of the (111) crystal plane of the first surface S1 in the diffraction spectrum Is between 0.5 and 2.0", "in the X-ray diffraction spectrum of the second surface S2 of the electrolytic copper foil 110, the diffraction peak intensity I of the (200) crystal plane of the second surface S2 ( 200) a ratio of a diffraction peak intensity I(111) of the (111) crystal plane of the second surface S2 is also between 0.5 and 2.0", and "the copper electrolyte contains at least one additive, and The concentration of at least one of the additives is not more than 12 parts by weight (ppm) based on the total weight of the copper electrolyte, so that the electrolytic copper foil 110 has a high elongation, and The production cost of the electrolytic copper foil 110 can be reduced, and the production stability of the electrolytic copper foil 110 can be improved.

Further, since the crystal orientation of the electrodeposited copper foil 110 of the present embodiment is mainly a (200) crystal plane and a (111) crystal plane, the crystal grains of the electrodeposited copper foil 110 are likely to slip. The phenomenon of shifting allows the electrolytic copper foil 110 to have a high elongation. From another point of view, since the crystal structure of the electrolytic copper foil 110 of the present embodiment is a bulk crystal structure, the electrolytic copper foil 110 can have a high elongation.

The above disclosure is only a preferred and feasible embodiment of the present invention, and is not intended to limit the scope of the patent application of the present invention. Therefore, any equivalent technical changes made by using the present specification and the content of the schema are included in the application for this creation. Within the scope of the patent.

E‧‧‧Lithium ion secondary battery

100‧‧‧negative

110‧‧‧electrolytic copper foil

111‧‧‧ Raw foil layer

S1‧‧‧ first surface

S2‧‧‧ second surface

SS‧‧‧Glossy surface (S surface)

MS‧‧‧ another glossy surface (M side)

112a‧‧‧First anti-oxidation treatment layer

112b‧‧‧Second antioxidant treatment layer

120a‧‧‧First active material layer

120b‧‧‧Second active material layer

200‧‧‧ positive

300‧‧‧Separator

400‧‧‧electrolyzer

R‧‧‧ accommodating space

Figure 1 is a side elevational view of an electrolytic copper foil of the presently-created embodiment.

2 is an X-ray diffraction spectrum of the electrolytic copper foil of the present embodiment.

Fig. 3 is a view showing a focused ion beam (FIB) image of an electrolytic copper foil according to an embodiment of the invention.

4 is a side view showing the negative electrode of the present embodiment.

Fig. 5 is a schematic view of a lithium ion secondary battery of the present embodiment.

Claims (15)

A lithium ion secondary battery comprising: an electrolytic cell having an accommodating space for accommodating an electrolyte; a positive electrode disposed in the accommodating space of the electrolytic cell; and a negative electrode disposed at the The accommodating space of the electrolytic cell is disposed at a distance from the positive electrode; wherein the negative electrode comprises an electrolytic copper foil, and the electrolytic copper foil has a first surface and opposite to the first surface a second surface; and a separator disposed between the positive electrode and the negative electrode; wherein, in the X-ray diffraction spectrum of the first surface of the electrolytic copper foil, the first surface The ratio of the diffraction peak intensity I (200) of the (200) crystal plane to the diffraction peak intensity I (111) of the (111) crystal plane of the first surface is between 0.5 and 2.0; a diffraction peak intensity I (200) of the (200) crystal plane of the second surface and (111) crystallization of the second surface in an X-ray diffraction spectrum of the second surface of the electrolytic copper foil The ratio of the diffraction peak intensity I(111) of the face is also between 0.5 and 2.0. The lithium ion secondary battery according to claim 1, wherein a distance between the first surface and the second surface is defined as a thickness, and the thickness is between 2 μm and 20 μm between. The lithium ion secondary battery according to claim 1, wherein the electrolytic copper foil has a pressure of 28 kgf/mm ² to 40 kgf/mm ² before any heat treatment step is performed. A tensile strength and an elongation of not less than 7%. The lithium ion secondary battery according to claim 1, wherein the electrolytic copper foil has a heat treatment step of 25 kgf/mm ² to 35 kgf/mm ² after a heat treatment step. a tensile strength, and an elongation of not less than 9.5%; wherein the heat treatment step comprises baking the electrolytic copper foil at a temperature of 130 ° C to 250 ° C for 0.5 hours to 1.5 hours. The lithium ion secondary battery according to claim 1, wherein the electrolytic copper foil further comprises: a first oxidation resistant layer disposed on the first surface; and a second oxidation treatment a layer disposed on the second surface; wherein, the first anti-oxidation treatment layer and the second anti-oxidation treatment layer both have a total weight content based on the total weight of the electrolytic copper foil 1 part per million (ppm) to 1,000 parts by weight of a non-copper metal element, and the non-copper metal element is selected from the group consisting of chromium, zinc, nickel, molybdenum, manganese, phosphorus At least one element of the group consisting of its composition. The lithium ion secondary battery according to claim 1, wherein the electrolytic copper foil has a plurality of crystal grains, and the crystal grain size of the plurality of crystal grains before the heat treatment step is Between 20 nm and 45 nm, and the grain size of the plurality of the crystal grains of the electrolytic copper foil after a heat treatment step is a plurality of the same as before the heat treatment step The grain size of the grains is between 90% and 130%. An electrolytic copper foil comprising: a primary foil layer having a first surface and a second surface opposite to the first surface; wherein, in the X-ray diffraction spectrum of the first surface, the first The ratio of the diffraction peak intensity I (200) of the (200) crystal plane of the surface to the diffraction peak intensity I (111) of the (111) crystal plane of the first surface is between 0.5 and 2.0; In the X-ray diffraction spectrum of the second surface, a diffraction peak intensity I (200) of the (200) crystal plane of the second surface and a diffraction peak of the (111) crystal plane of the second surface The ratio of the intensity I (111) is also between 0.5 and 2.0. The electrolytic copper foil according to claim 7, wherein a distance between the first surface and the second surface is defined as a thickness, and the thickness is between 2 micrometers and 20 micrometers. . The electrolytic copper foil according to claim 7, wherein the electrolytic copper foil has a copper foil of between 28 kgf/mm ² and 40 kgf/mm ² before any heat treatment step. A tensile strength and an elongation of not less than 7%. The electrolytic copper foil according to claim 9, wherein the electrolytic copper foil has a heat treatment step of between 25 kgf/mm ² and 35 kgf/mm ² after a heat treatment step. a tensile strength, and an elongation of not less than 9.5%; wherein the heat treatment step comprises baking the electrolytic copper foil at a temperature between 130 ° C and 250 ° C for 0.5 hours to 1.5 hours. . The electrolytic copper foil according to claim 7, wherein the electrolytic copper foil has a tensile strength after a heat treatment step of 65% to 95% of the tensile strength before the heat treatment step is not performed. Between, and the elongation of the electrolytic copper foil after the heat treatment step is between 100% and 140% of its elongation before any heat treatment step. The electrolytic copper foil according to claim 7, further comprising: a first oxidation resistant layer disposed on the first surface; and a second oxidation resistant layer disposed on the second The first anti-oxidation treatment layer and the second anti-oxidation treatment layer each comprise a total weight content of 1 part per million (Parts) based on the total weight of the electrolytic copper foil. Per million, ppm) to a non-copper metal element of 1,000 parts by weight, and the non-copper metal element is selected from the group consisting of chromium, zinc, nickel, molybdenum, manganese, phosphorus, and combinations thereof. At least one element in the group. The electrolytic copper foil according to claim 7, wherein the first surface is further defined as a surface in contact with a rotating method drum in a plating process, and is defined as an S surface ( S surface), and the second surface is further defined as a surface opposite to the S surface, and is defined as an M surface; wherein, in the X-ray diffraction spectrum of the S-plane, the The ratio of the diffraction peak intensity I (200) of the (200) crystal plane of the S plane to the diffraction peak intensity I (111) of the (111) crystal plane of the S plane is defined as a first diffraction peak intensity ratio; And in the X-ray diffraction spectrum of the M-plane, the diffraction peak intensity I (200) of the (200) crystal plane of the M plane and the diffraction peak intensity I of the (111) crystal plane of the M plane The ratio of (111) is defined as a second diffraction peak intensity ratio; wherein the first diffraction peak intensity ratio is less than the second diffraction peak intensity ratio. The electrolytic copper foil according to claim 13, wherein an absolute value of a difference between the first diffraction peak intensity ratio and the second diffraction peak intensity ratio is not less than 0.01 and not more than 0.30. The electrolytic copper foil according to claim 7, wherein the electrolytic copper foil has a plurality of crystal grains, and the crystal grain size of the plurality of crystal grains before the heat treatment step is 20 Between nanometers and 45 nanometers, and the grain size of the plurality of the crystal grains of the electrolytic copper foil after a heat treatment step is a plurality of the crystal grains before the heat treatment step The grain size is between 90% and 130%.