KR20190143191A - Copper foil with high stability, electrode comprisng the same, secondary battery comprising the same and method for manufacturing the same - Google Patents

Abstract

One embodiment of the present invention provides a copper foil including a copper layer and having proportion of thickness to profile peak height (PTP) of 0.02 to 0.37, bias for proportion of thickness to profile peak height (BPTP) of 0.71, and full width at half maximum (FWHM) variation rate of 0.79 to 1.21. The copper foil has the excellent resistance to wrinkles or tearing.

Description

High reliability copper foil, electrode comprising the same, secondary battery comprising the same, and a method for manufacturing the same

The present invention relates to a copper foil having excellent reliability by minimizing wrinkles and tears, an electrode comprising the same, a secondary battery comprising the same, and a manufacturing method thereof.

Copper foil is used to manufacture a variety of products, such as secondary battery negative electrode, flexible printed circuit board (FPCB).

Among these, the copper foil manufactured by electroplating is also called electrolytic copper foil. Such copper foil is generally manufactured through a roll to roll (RTR) process, and is also used to manufacture a negative electrode, a flexible printed circuit board (FPCB), and the like of a secondary battery through a roll to roll (RTR) process. Since continuous production is possible, the roll-to-roll (RTR) process is known to be suitable for mass production of products. Since the copper foil has a thin thickness, if the production conditions are not precisely controlled during the production of the copper foil or during the manufacture of the product using the copper foil, the copper foil may be torn or wrinkles may occur in the electrolytic copper foil. In this case, productivity is reduced because the process equipment has to be shut down and the problems caused must be restarted.

9 is a photograph of a state where tearing occurs in the copper foil.

When the tearing or wrinkles as shown in Figure 9 occurs in the manufacturing process of the copper foil, or when the wrinkles or tearing occurs in the copper foil in the process of manufacturing a secondary battery using the copper foil, it is difficult to produce a stable product, the production yield of the product This lowers and causes the manufacturing cost of the product to increase.

Among the causes of wrinkles and tearing defects generated in the manufacturing process of a product using a copper foil, for example, a secondary battery, a method of controlling the weight deviation of the copper foil to a low level is known as a method for solving the cause caused by the copper foil. . However, there is a limit in solving the problem of wrinkles and tears occurring in the secondary battery manufacturing process only by controlling the weight deviation of the copper foil. In particular, as the ratio of ultra-thin copper foil, for example, a copper foil having a thickness of 8 μm or less is used as a negative electrode current collector to increase the capacity of a secondary battery in recent years, even if the weight deviation of the copper foil is precisely controlled, the secondary battery Wrinkles and tearing defects are intermittently occurring in the manufacturing process of. Therefore, in the manufacturing process of a secondary battery, it is necessary to prevent or suppress that wrinkles and tearing generate | occur | produce in a copper foil.

The present invention is to provide a copper foil that can solve the above problems, an electrode comprising the same, a secondary battery comprising the same, and a manufacturing method thereof.

One embodiment of the present invention is to provide a copper foil minimized wrinkles or tearing. One embodiment of the present invention is to provide a copper foil having excellent processability and reliability by preventing wrinkles, tearing, and crying in the manufacturing process of a secondary battery, even though it has a thin thickness.

Another embodiment of the present invention is to provide a secondary battery electrode including such a copper foil and a secondary battery comprising such a secondary battery electrode.

Another embodiment of the present invention is to provide a flexible copper foil laminated film comprising such a copper foil.

Another embodiment of the present invention, to prevent the occurrence of wrinkles, tearing or crying during the manufacturing process to provide a method for producing a copper foil with improved reliability.

In addition to the above-mentioned aspects of the present invention, other features and advantages of the present invention will be described below, or from such description will be clearly understood by those skilled in the art.

In order to solve this problem, an embodiment of the present invention includes a copper layer, a thickness of profile peak ratio (PTP) of 0.02 to 0.37, thickness profile peak ratio of 0.71 or less ( Bias for Proportion of Thickness to Profile peak height (BPTP) and Full Width at Half Maximum (FWHM) variation rate of 0.79 to 1.21.

Here, the thickness profile peak ratio (PTP) is obtained by Equation 1 below.

[Equation 1]

PTP = Rp / T _copper

In Equation 1, Rp is the peak roughness of the copper foil, and T _copper is the thickness of the _copper foil.

The thickness profile peak ratio bias (BPTP) is obtained by Equation 2 below.

[Equation 2]

BPTP = (PTPmax-PTPmin) / PTPave

In Equation 2, PTPmax is the maximum value of the thickness profile peak ratio (PTP), PTPmin is the minimum value of the thickness profile peak ratio (PTP), PTPave is the average value of the thickness profile peak ratio (PTP).

The FWHM fluctuation rate is obtained by the following Equation 3.

[Equation 3]

Half-width variation = (half-width after heat treatment) / (half-width before heat treatment)

The half width after the heat treatment in Equation 3 indicates the half width (FWHM) of the (220) surface of the copper foil after the heat treatment at 110 ° C. for 30 minutes, and the half width before the heat treatment is the (220) of the copper foil before the heat treatment at 110 ° C. for 30 minutes. The half width (FWHM) of the plane is shown.

At room temperature (25 ± 15 ° C.), the texture coefficient [TC (220)] of the (220) plane is 0.48 to 1.28.

The copper foil has a maximum height roughness Rmax of 0.6 to 3.5 mu m.

The copper foil has a weight deviation of 3% or less.

The copper foil further includes an antirust film disposed on the copper layer.

The rust preventive film includes at least one of chromium (Cr), a silane compound, and a nitrogen compound.

Another embodiment of the present invention provides an electrode for a secondary battery including the copper foil and an active material layer disposed on the copper foil.

Another embodiment of the present invention, a cathode (cathode), an anode facing the anode, an electrolyte (electrolyte) disposed between the anode and the cathode to provide an environment in which lithium ions can move and A separator is provided to electrically insulate the positive electrode and the negative electrode, and the negative electrode provides a secondary battery including the copper foil and an active material layer disposed on the copper foil.

Another embodiment of the present invention provides a flexible copper foil laminated film comprising a polymer film and the copper foil disposed on the polymer film.

Another embodiment of the present invention, the electrode layer (anode) and the rotating electrode drum (cathode) disposed to be spaced apart from each other in the electrolytic solution containing copper ions to the current density of 40 to 80 A / dm ² copper layer It provides a step, wherein the electrolyte provides a method for producing a copper foil containing 70 to 90 g / L copper ions, 50 to 150 g / L sulfuric acid and 15 ppm or less arsenic (As).

The electrolyte solution contains 2 to 20 ppm of auramine.

The electrolyte solution contains 2 to 20 ppm citric acid.

Before forming the copper layer, polishing the surface of the rotating electrode drum with a brush having a particle size of # 800 to # 3000.

The electrolyte is circulated at a flow rate of 39 to 46 m ³ / hour.

The flow rate deviation of the electrolyte is 5% or less per unit time (seconds).

The general description of the present invention as described above is only for illustrating or explaining the present invention, and does not limit the scope of the present invention.

Copper foil according to an embodiment of the present invention has excellent resistance to wrinkles or tearing, the occurrence of wrinkles, tearing or crying in the manufacturing process of the copper foil or the manufacturing process of the secondary battery using the copper foil. As a result, a stable product can be produced, a production yield of the product is improved, and a rise in the manufacturing cost of the product is prevented, and the reliability of the product is improved.

In addition, the copper foil according to an embodiment of the present invention has excellent roll-to-roll (RTR) processability, according to another embodiment of the present invention can be produced an electrode for secondary batteries that is prevented or minimized generation of wrinkles, tearing or crying have.

The accompanying drawings are included to assist in understanding the invention and to form a part of the specification, to illustrate embodiments of the invention, and to explain the principles of the invention in conjunction with the description.
1 is a schematic cross-sectional view of a copper foil according to an embodiment of the present invention.
FIG. 2A is an example for the graph of the roughness profile, and FIG. 2B is an example for the XRD graph of the copper foil.
3 is a schematic cross-sectional view of a copper foil according to another embodiment of the present invention.
4 is a schematic cross-sectional view of an electrode for a secondary battery according to another embodiment of the present invention.
5 is a schematic cross-sectional view of an electrode for a secondary battery according to another embodiment of the present invention.
6 is a schematic cross-sectional view of a secondary battery according to another embodiment of the present invention.
7 is a cross-sectional view of a flexible copper clad laminate according to another embodiment of the present invention.
8 is a schematic view of the manufacturing process of the copper foil shown in FIG.
9 is a photograph of a state where tearing occurs in the copper foil.

Hereinafter, with reference to the accompanying drawings will be described embodiments of the present invention;

It will be apparent to those skilled in the art that various changes and modifications of the present invention are possible without departing from the spirit and scope of the present invention. Accordingly, the invention includes all modifications and variations within the scope of the invention as set forth in the claims and their equivalents.

Shapes, sizes, ratios, angles, numbers, and the like disclosed in the drawings to describe embodiments of the present invention are exemplary, and thus the present invention is not limited by the matters shown in the drawings. Like elements may be referred to by like reference numerals throughout the specification.

In the case where 'comprises', 'haves', 'consists of' and the like mentioned in the present specification are used, other parts may be added unless the expression 'only' is used. When a component is expressed in the singular, the plural is included unless specifically stated otherwise. In addition, in interpreting a component, even if there is no separate description, it is interpreted as including an error range.

In the case of the description of the positional relationship, for example, if the positional relationship of the two parts is described as 'on', 'upon', 'lower', 'next to', etc. Alternatively, one or more other parts may be located between the two parts unless the expression 'direct' is used.

In the case of a description of a temporal relationship, for example, if the temporal after-term relationship is described as 'after', 'following', 'after', 'before', or the like, 'directly' or 'direct' It may also include non-contiguous cases unless the expression is used.

In order to describe the various components, expressions such as 'first', 'second' and the like are used, but these components are not limited by these terms. These terms are only used to distinguish one component from another. Therefore, the first component mentioned below may be a second component within the technical spirit of the present invention.

The term "at least one" should be understood to include all combinations which can be presented from one or more related items.

Each of the features of the various embodiments of the invention may be combined or combined with one another, in whole or in part, and various technically interlocking and driving are possible, and each of the embodiments may be independently implemented with respect to each other or may be implemented together in an association. It may be.

1 is a schematic cross-sectional view of a copper foil 100 according to an embodiment of the present invention.

Referring to FIG. 1, the copper foil 100 includes a copper layer 110. According to an embodiment of the present invention, the copper foil 100 may further include an antirust film 210 disposed on the copper layer 110. The rustproof film 210 may be omitted.

According to one embodiment of the present invention, the copper layer 110 has a matte surface MS and a shiny surface SS on the opposite side.

The copper layer 110 may be formed on the rotating electrode drum, for example, by electroplating (see FIG. 8). At this time, the shiny surface (SS) refers to the surface that was in contact with the rotating electrode drum during the electroplating process, the mat surface (MS) refers to the surface opposite to the shiny surface (SS).

Although it is common for the shiny surface SS to have a lower surface roughness Rz than the mat surface MS, one embodiment of the present invention is not limited thereto. The surface roughness Rz of the shiny surface SS may be equal to or higher than the surface roughness Rz of the mat surface MS.

The rustproof layer 210 may be disposed on at least one of the mat surface MS and the shiny surface SS of the copper layer 110. Referring to FIG. 1, the rustproof membrane 210 is disposed on the mat surface MS. However, one embodiment of the present invention is not limited thereto, and the rustproof film 210 may be disposed only on the shiny surface SS or may be disposed on both the mat surface MS and the shiny surface SS.

The rust preventive layer 210 protects the copper layer 110. The rustproof film 210 may prevent the copper layer 110 from being oxidized or deteriorated during the preservation process. Therefore, the antirust film 210 is also called a protective layer.

According to an embodiment of the present invention, the rustproof membrane 210 may include at least one of chromium (Cr), a silane compound, and a nitrogen compound.

For example, the rust-preventing film 210 may be made of a rust-preventing solution containing chromium (Cr), that is, a rust preventing solution containing a chromic acid compound.

According to an embodiment of the present invention, the copper foil 100 has a first surface S1 that is a surface in the mat plane MS direction and a second surface that is a surface in the SHINee surface SS direction based on the copper layer 110. Has (S2). In FIG. 1, the first surface S1 of the copper foil 100 is the surface of the rustproof film 210, and the second surface S2 is the shiny surface SS. When the rustproof film 210 is not disposed on the copper layer 110, the mat surface MS of the copper layer 110 becomes the first surface S1 of the copper foil 100.

According to an embodiment of the present invention, the copper foil 100 has a Proportion of Thickness to Profile peak height (PTP) of 0.02 to 0.37.

The thickness profile peak ratio (PTP) of the copper foil 100 is obtained by the following equation.

[Equation 1]

PTP = Rp / T _copper

In formula 1, "Rp" is the peak roughness of the copper foil, and "T _copper " is the thickness of the copper foil.

According to one embodiment of the invention, the "peak roughness (Rp)" can be measured with a roughness meter according to JIS B 0601-2001 standard. For example, the peak roughness Rp may be measured by an illuminometer (SJ-310) manufactured by Mitutotyo. Specifically, using Mitutotyo's SJ-310 roughness meter, the measurement length excluding the cut off length is 4mm, the initial and the end cutoff lengths are 0.8mm, respectively, and the stylus tip (Stylus) Tip) After setting the radius (Radius) to 2㎛ and the measurement pressure to 0.75mN Rp value can be measured. The measured value corresponds to the peak roughness Rp based on the Mitutoyo illuminometer measurement value.

2A is an example of a graph of a surface roughness profile. As shown in FIG. 2A, peak roughness Rp means the height of the highest peak from the mean line ML of the surface roughness profile (sampling length: 4 mm).

The thickness T _copper of the copper foil 100 is obtained from the weight of the copper foil per unit area and the density of the copper foil.

For example, the thickness of the copper foil 100 may be obtained from a sample of the copper foil 100 having an area of 10 cm x 10 cm. Specifically, when the weight of the copper foil 100 having an area of 10cm x 10cm is C g, considering that the density of copper is 8.94g / cm ³ , the thickness of the copper foil 100 according to the following equation 1 Can be done.

[Calculation 1]

When the thickness profile peak ratio (PTP) is less than 0.02, the surface profile of the copper foil 100 may be low, such that wrinkles may occur due to slip in a product using the copper foil 100, for example, a secondary battery manufacturing process. When the thickness profile peak ratio (PTP) exceeds 0.37, the thickness profile of the copper foil 100 is high, so that the secondary battery is manufactured by a roll to roll process. Notch) may cause tearing of the copper foil 100.

According to one embodiment of the present invention, the copper foil 100 has a bias for Proportion of Thickness to Profile peak height (BPTP) of 0.71 or less.

Thickness profile peak ratio bias (BPTP) of copper foil 100 is calculated | required by following formula (2).

[Equation 2]

BPTP = (PTPmax-PTPmin) / PTPave

In Equation 2, PTPmax is the maximum value of the thickness profile peak ratio (PTP), PTPmin is the minimum value of the thickness profile peak ratio (PTP), and PTPave is the average value of the thickness profile peak ratio (PTP).

PTPmax, PTPmin and PTPave can be obtained as follows. PTP is measured and averaged three times in three width directions (left L, center C, and right R) of the copper foil 100, and the average value of the lowest point is called PTPmin, and the average value of the highest point is The average of all nine PTP values measured at three points is called RRTmax.

When the thickness profile peak ratio bias (BPTP) exceeds 0.71, due to the difference in the local thickness profile peak ratio, the copper foil 100 may be used in the manufacturing process of a product using a roll to roll process, for example, a secondary battery. ) Tear or wrinkles may occur.

In addition, the copper foil 100 has a full width at half maximum (FWHM) variation rate of 0.79 to 1.21.

The change in FWHM is given by Equation 3 below.

[Equation 3]

Half-width variation = (half-width after heat treatment) / (half-width before heat treatment)

The half width after the heat treatment in Equation 3 is the half width (FWHM) of the (220) surface of the copper foil 100 after the heat treatment at 110 ℃ for 30 minutes, the half width before heat treatment before the heat treatment at 110 ℃ for 30 minutes copper foil (100) Measured at room temperature (25 ° C. ± 15 ° C.) at half width (FWHM) of the (220) plane.

The full width can be obtained from the XRD graph of the copper foil 100.

2B is an example of the XRD graph of the copper foil. Referring to FIG. 2B, X-ray diffraction analysis (XRD) in the diffraction angle (2θ) range of 30 ° to 95 ° [(i) Target: Copper K alpha 1, (ii) 2θ interval: 0.01 °, (iii) 2θ scan speed: 3 [deg.] / min], an XRD graph having peaks corresponding to n crystal planes can be obtained. The half width (FWHM) of the (220) surface of the copper foil 100 is measured from the obtained XRD graph of the copper foil 100. The full width (FWHM) can be obtained from the software of an X-ray diffraction analysis (XRD) device.

The FWHM fluctuation rate of the XRD peak (FWHM) of the (220) plane of the copper foil 100 is less than 0.79 or more than 1.21, for example, a product manufactured using the copper foil 100, for example, a secondary battery. It means that the dimensions of the copper foil 100 is greatly changed by the thermal history received in the manufacturing process. Due to such dimensional variation, wrinkles may occur in a secondary battery manufacturing process by roll-to-roll (RTR).

According to an embodiment of the present invention, the copper foil 100 has a (220) plane, and the texture coefficient [TC (220)] of the (220) plane of the copper foil 100 at room temperature (25 ± 15 ° C.) is 0.48. To 1.28. The texture coefficient TC 220 is related to the crystal structure of the copper foil 100 surface.

Hereinafter, with reference to FIG. 2B, the method of measuring and calculating the texture coefficient (TC 220) of the (220) plane of copper foil is demonstrated.

Referring to FIG. 2B, first, X-ray diffraction analysis (XRD) in a diffraction angle (2θ) range of 30 ° to 95 ° [Target: Copper K alpha 1, 2θ interval: 0.01 °, 2θ scan speed: 3 ° / min ] Results in an XRD graph with peaks corresponding to n crystal planes. For example, as illustrated in FIG. 2B, an XRD graph showing peaks corresponding to the (111) plane, the (200) plane, the (220) plane, and the (311) plane may be obtained.

Next, the XRD diffraction intensity [I (hkl)] of each crystal plane hkl is obtained from this graph. In addition, the XRD diffraction intensity [I ₀ (hkl)] for each of the n crystal planes of the standard copper powder defined by Joint Committee on Powder Diffraction Standards (JCPDS) is obtained. Subsequently, an arithmetic mean value of I (hkl) / I ₀ (hkl) of the n crystal planes is calculated, and the I (220) / I ₀ (220) of the (220) plane is divided by the arithmetic mean value so that the (220) plane is obtained. The collective organization coefficient [TC 220] of is calculated. Specifically, the aggregated tissue coefficient (TC 220) of the (220) plane is calculated based on the following equation (4).

[Equation 4]

According to one embodiment of the invention, the (220) surface of each of the first and second surfaces (S1, S2) of the copper foil 100 may have a texture coefficient [TC (220)] of 0.48 to 1.28.

 If the texture coefficient [TC (220)] of the (220) plane is less than 0.48, the crystal structure of the copper foil 100 is not dense, and the structure is deformed by the stress and heat received in the secondary battery manufacturing process, and the copper foil 100 Wrinkles are generated. If the coefficient of texture of the (220) plane exceeds 1.28, the structure of the copper foil 100 is too dense and brittle, resulting in tearing of the copper foil 100 in the secondary battery manufacturing process, which may cause difficulty in producing a stable product. have.

According to one embodiment of the invention, the copper foil 100 has a maximum height roughness (Rmax) of 0.6 to 3.5㎛.

The maximum height roughness Rmax can be measured with an illuminometer according to JIS B 0601-2001. For example, the maximum height roughness Rmax may be measured by Mitutoyo SJ-310 model. Specifically, the measurement length 4mm, excluding the cut off length, the cut-off length of the beginning and end of each 0.8mm, the radius of the stylus tip (Radius) is 2㎛, the measurement pressure 0.75mN Rmax value can be obtained by measuring with. The measured value corresponds to the maximum height roughness (Rmax) of the Mitutoyo illuminometer measurement standard.

If the maximum height roughness (Rmax) of the copper foil 100 is less than 0.6 μm, there may not be enough active sites on the surface of the copper foil 100 to which the active material may be coated, and thus the active material may not be sufficiently bonded to the copper foil 100 with sufficient bonding strength. have. Accordingly, peeling of the active material may occur on the surface of the copper foil 100.

When the maximum height roughness Rmax of the copper foil 100 exceeds 3.5 μm, the active material may not be uniformly coated on the surface of the copper foil 100 due to the unevenness of the surface of the copper foil 100.

According to one embodiment of the invention, the copper foil 100 has a weight deviation of 3% or less.

The weight deviation is to take the 10cm x 10cm samples from each of the three points arranged along the width direction of the copper foil 100, that is, TD (Transverse Direction), and then measure the weight of each sample to calculate the weight per unit area, From the weight per unit area of three samples can be obtained by calculating "average weight of three points" and "standard deviation of weight". The weight deviation can be calculated by the following equation.

[Equation 5]

When the weight variation of the copper foil 100 exceeds 3%, wrinkles or crying may occur in the copper foil 100 due to the tension or weight overlap applied to the copper foil 100 during the roll-to-roll process for manufacturing the secondary battery.

In addition, according to an embodiment of the present invention, the copper foil 100 may have a thickness of 4 ㎛ to 30 ㎛. When the thickness of the copper foil 100 is less than 4 micrometers, workability | operativity falls in the manufacturing process of the secondary battery electrode or secondary battery using the copper foil 100. FIG. When the thickness of the copper foil 100 exceeds 30㎛, the thickness of the electrode for the secondary battery using the copper foil 100 is increased, due to such a large thickness may cause difficulties in implementing high capacity of the secondary battery.

3 is a schematic cross-sectional view of a copper foil 200 according to another embodiment of the present invention. Hereinafter, in order to avoid duplication, the description of the components already described will be omitted.

Referring to FIG. 3, the copper foil 200 according to another embodiment of the present invention includes two rust preventive layers disposed on the mat layer MS and the shiny surface SS of the copper layer 110 and the copper layer 110, respectively. Membranes 210 and 220. Compared to the copper foil 100 shown in FIG. 1, the copper foil 200 shown in FIG. 3 further includes an rust-proof film 220 disposed on the shiny surface SS of the copper layer 110.

For convenience of description, the rustproof film 210 disposed on the mat surface MS of the copper layer 110 among the two rustproof films 210 and 220 is called a first protective layer and is disposed on the shiny surface SS. The rustproof film 220 may be referred to as a second protective layer.

The first surface S2 of the copper foil 200 illustrated in FIG. 3 is the surface of the rustproof film 210 disposed on the mat surface MS, and the second surface S2 is the rust preventive surface disposed on the shiny surface SS. The surface of the membrane 220.

According to another embodiment of the present invention, the two rust preventive membranes 210 and 220 may each include at least one of chromium (Cr), a silane compound, and a nitrogen compound.

The copper foil 200 shown in FIG. 3 has a thickness profile peak ratio (PTP) of 0.02 to 0.37, a thickness profile peak ratio bias (BPTP) of 0.71 or less, a half width (FWHM) variation rate of 0.79 to 1.21, and 0.6 to 3.5 µm. Maximum height roughness Rmax and weight deviation of 3% or less.

In addition, in the copper foil 200 shown in FIG. 3, the texture coefficient (TC 220) of the (220) plane at room temperature (25 ± 15 ° C) is 0.48 to 1.28. The copper foil 200 shown in FIG. 3 may have a thickness of 4 μm to 30 μm.

4 is a schematic cross-sectional view of a secondary battery electrode 300 according to another embodiment of the present invention.

Referring to FIG. 4, a secondary battery electrode 300 according to another embodiment of the present invention includes a copper foil 100 and an active material layer 310 disposed on the copper foil 100. For example, the secondary battery electrode 300 illustrated in FIG. 4 may be applied to the secondary battery 500 illustrated in FIG. 6.

Although the structure in which the active material layer 310 is disposed only on the first surface S1 of the surfaces S1 and S2 of the copper foil 100 is illustrated in FIG. 4, another embodiment of the present invention is not limited thereto. . The active material layer 310 may be disposed on both the first surface S1 and the second surface S2 of the copper foil 100, and the active material layer 310 may be formed only on the second surface S2 of the copper foil 100. It may be arranged.

Specifically, the secondary battery electrode 300 according to another embodiment of the present invention is the copper foil 100 having the first surface (S1) and the second surface (S2) and the first surface (S1) of the copper foil (100) ) And the active material layer 310 disposed on at least one of the second surface S2.

4 shows that the copper foil 100 of FIG. 1 is used as the current collector. However, another embodiment of the present invention is not limited thereto, and the copper foil 200 illustrated in FIG. 3 may be used as the current collector of the electrode 300 for secondary batteries.

In the secondary battery electrode 300, the copper foil 100 is used as a current collector. For example, the copper foil 100 may be used as a cathode current collector or a cathode current collector.

The active material layer 310 shown in FIG. 4 is made of an electrode active material, and in particular, may be made of a negative electrode active material. For example, the secondary battery electrode 300 illustrated in FIG. 4 may be used as a negative electrode.

The active material layer 310 may include at least one of carbon, a metal, an oxide of metal, and a complex of metal and carbon. As the metal, at least one of Ge, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe may be used. In addition, in order to increase the charge / discharge capacity of the secondary battery, the active material layer 310 may include silicon (Si).

When the copper foil 100 according to an embodiment of the present invention is used, tearing or wrinkle of the copper foil 100 is prevented in the manufacturing process of the electrode 300 for secondary batteries. Accordingly, the manufacturing efficiency of the secondary battery electrode 300 may be improved, and the charge and discharge efficiency and the capacity retention rate of the secondary battery including the secondary battery electrode 300 may be improved.

5 is a schematic cross-sectional view of a secondary battery electrode 400 according to another embodiment of the present invention.

The secondary battery electrode 400 according to another exemplary embodiment of the present invention includes the copper foil 200 and the active material layers 310 and 320 disposed on the copper foil 200.

Referring to FIG. 5, the copper foil 200 includes a copper layer 110 and two antirust films 210 and 220 disposed on both surfaces of the copper layer 110.

In addition, the electrode 300 for secondary batteries illustrated in FIG. 5 includes two active material layers 310 and 320 disposed on both surfaces of the copper foil 200. Here, the active material layer 310 disposed on the first surface S1 of the copper foil 200 is referred to as a first active material layer, and the active material layer 320 disposed on the second surface S2 of the copper foil 200 is referred to as a first active material layer. It may be referred to as a second active material layer.

The two active material layers 310 and 320 may be made of the same material by the same material, or may be made of different materials or different methods.

6 is a schematic cross-sectional view of a secondary battery 500 according to another embodiment of the present invention. The secondary battery 500 illustrated in FIG. 6 is, for example, a lithium secondary battery.

Referring to FIG. 6, the secondary battery 500 includes a cathode 370, an anode 340 disposed opposite the anode 370, and ions between the cathode 370 and the cathode 340. An electrolyte 350 provides a mobile environment, and a separator 360 electrically insulates the positive electrode 370 and the negative electrode 340. Here, the ions moving between the anode 370 and the cathode 340 are lithium ions. The separator 360 separates the positive electrode 370 and the negative electrode 340 to prevent the charge generated from one electrode from moving unnecessarily through the inside of the secondary battery 500 to the other electrode. Referring to FIG. 6, the separator 360 is disposed in the electrolyte 350.

The positive electrode 370 includes a positive electrode current collector 371 and a positive electrode active material layer 372. Aluminum foil may be used as the positive electrode current collector 371.

The negative electrode 340 includes a negative electrode current collector 341 and a negative electrode active material layer 342. The negative electrode active material layer 342 includes a negative electrode active material.

As the negative electrode current collector 341, the copper foils 100 and 200 disclosed in FIGS. 1 and 3 may be used. In addition, the secondary battery electrodes 300 and 400 illustrated in FIGS. 4 and 5 may be used as the negative electrode 340 of the secondary battery 500 illustrated in FIG. 6.

7 is a schematic cross-sectional view of the flexible copper clad laminate 600 according to another embodiment of the present invention.

The flexible copper clad laminate 600 according to another embodiment of the present invention includes a polymer film 410 and a copper foil 100 disposed on the polymer film 410. Although the flexible copper foil laminated film 600 including the copper foil 100 illustrated in FIG. 1 is illustrated in FIG. 7, another embodiment of the present invention is not limited thereto. For example, it may be used for the copper foil 200 shown in FIG. 3 or the flexible copper foil laminated film 600 of FIG. 7.

The polymer film 410 has flexibility and nonconductivity. There is no particular limitation on the type of the polymer film 410. The polymer film 410 may include polyimide, for example. The polyimide film and the copper foil 100 may be laminated through a roll press to make the flexible copper clad laminated film 600. Alternatively, the polyimide precursor solution may be coated on the copper foil 100 and then heat-treated to make the flexible copper foil laminated film 600.

The copper foil 100 may be formed of at least one of a copper layer 110 having a mat surface MS and a shiny surface SS and at least one of a mat surface MS and a shiny surface SS of the copper layer 110. 210). Here, the rust preventive film 210 may be omitted.

Referring to FIG. 7, although the polymer film 410 is disposed on the rustproof film 210, another embodiment of the present invention is not limited thereto. The polymer film 410 may be disposed on the shiny surface SS of the copper layer 110.

Hereinafter, with reference to FIG. 8, the manufacturing method of the copper foil 200 which concerns on other embodiment of this invention is demonstrated concretely.

8 is a schematic diagram of a manufacturing method of the copper foil 200 shown in FIG. 3.

First, the electrode plate 13 and the rotating electrode drum 12 which are spaced apart from each other in the electrolyte solution 11 containing copper ions are energized at a current density of 40 to 80 ASD (A / dm ² ), thereby forming the copper layer 110. ).

The electrolyte solution 11 contains 70 to 90 g / L of copper ions and 50 to 150 g / L of sulfuric acid.

The electrolyte solution 11 contains arsenic (As) of 15 ppm or less. Here, arsenic (As) contains arsenic ions in the state dissociated in the electrolyte (11).

Arsenic (As) corresponds to impurities in the electrolyte solution 11, and the concentration of arsenic (As) is controlled to 15 ppm or less. When the concentration of arsenic (As) in the electrolyte solution 11 exceeds 15 ppm, the peak roughness Rp of the copper foil 200 is increased so that the thickness profile peak ratio PTP of the copper foil 200 exceeds 0.37. . This phenomenon becomes worse when the thickness of the copper foil 200 is 6 µm or less.

In order to adjust the arsenic (As) concentration in the electrolyte solution 11 to 15 ppm or less, a raw material containing no arsenic (As) may be used, or arsenic (As) may be used during the formation of the copper layer 110 by plating. (11) Do not flow into. In order to maintain the concentration of arsenic (As) in the electrolyte solution 11 to 15 ppm or less, chlorine (Cl) is added to the electrolyte solution 11, so that arsenic (As) precipitates in the form of an arsenic chloride compound (AsClx), Arsenic (As) can be removed.

According to another embodiment of the present invention, the electrolyte solution 11 may include an additive. As an additive, for example, auramine may be used. The electrolyte solution 11 may include 2 to 20 ppm of auramine.

Oramine (auramine) may be represented by the following formula (1).

[Formula 1]

According to an embodiment of the present invention, the rate of change of the full width at half maximum (FWHM) of the (220) surface of the copper foil 100 may be controlled by the type and concentration of the additive. In particular, the copper foil 200 may be controlled by adjusting the concentration of oramin. The rate of change of the full width at half maximum (FWHM) of the (220) plane may be adjusted. If the concentration of oramin is less than 2 ppm, the rate of change of the half width (FWHM) of the copper foil 200 is less than 0.79. If the concentration of the oramin exceeds 20 ppm, the rate of change of the half width (FWHM) of the copper foil 200 is 1.21. Wrinkles may occur in excess of the copper foil 200.

As another additive, citric acid (CA) can be used. For example, the electrolyte solution 11 may include 2 to 20 ppm of citric acid (CA). Citric acid (CA) can be used as a polish.

When the concentration of citric acid (CA) in the electrolyte solution 11 is excessively high exceeding 20 ppm, the texture of the (220) plane of the copper foil 200 develops, and the texture coefficient of the (220) plane exceeds 1.28. On the contrary, when the concentration of citric acid (CA) in the electrolyte solution 11 is less than 2 ppm, the texture coefficient of the (220) plane of the copper foil 200 is less than 0.48.

According to another embodiment of the present invention, the electrode plate 13 and the rotating electrode drum 12 disposed spaced apart from each other in the electrolyte solution 11 contained in the electrolytic cell 10 are 40 to 80 ASD (A / dm ² ). The copper may be electrodeposited on the rotating electrode drum 12 by being energized at a current density of about 100 to form a copper layer 110. The spacing between the electrode plate 13 and the rotating electrode drum 12 can be adjusted in the range of 8 to 13 mm.

The higher the current density applied between the electrode plate 13 and the rotating electrode drum 12, the more uniform the plating is, so that the surface roughness of the mat surface MS of the copper layer 110 decreases, and the lower the current density, the more uneven. One plating is performed to increase the surface roughness of the mat surface MS.

The surface roughness of the shiny surface SS of the copper layer 110 may vary depending on the degree of polishing of the surface of the rotating electrode drum 12. In order to adjust the surface roughness of the shiny surface SS, the surface of the rotating electrode drum 12 may be polished with a brush having a grain size (Grit) of, for example, # 800 to # 3000, before the copper layer 110 is formed. have. For example, if the particle size (#) of the brush exceeds # 3000, the thickness profile peak ratio (PTP) may be less than 0.02.

In the process of forming the copper layer 110, the electrolyte solution 11 may be maintained at a temperature of 40 to 65 ℃.

In order to reduce the content of impurities in the electrolyte solution 11, the copper wire which is a material of copper ions is heat-treated, and after the heat-treated copper wire is pickled, the pickled copper wire may be introduced into sulfuric acid for the electrolyte.

The electrolyte solution 11 may be circulated at a flow rate of 39 to 46 m ³ / hour. During the circulation of the electrolyte solution 11, the electrolyte solution 11 may be filtered to remove solid impurities present in the electrolyte solution 11 while the electroplating for forming the copper layer 110 is performed. By filtration of the electrolyte solution 110, for example, by removing the arsenic chloride compound (AsClx), the arsenic (As) content in the electrolyte solution 11 can be maintained below 15 ppm.

When the flow rate of the electrolyte solution 11 is less than 39 m ³ / hour, a low flow rate may cause overvoltage, and the copper layer 110 may be formed unevenly. On the other hand, if the flow rate exceeds 46 m ³ / hour, the filter may be damaged and foreign matter may flow into the electrolyte 11.

In order for the copper foil 200 to have a weight variation of 3% or less in the width direction, the flow rate variation of the electrolyte solution 11 per unit time (seconds) may be controlled to 5% or less. When the flow rate deviation of the electrolyte solution 11 per unit time (seconds) exceeds 5%, a nonuniform copper layer 110 may be formed by non-uniform plating, thereby increasing the weight variation of the copper foil 200. can do.

In addition, when the flow rate deviation of the electrolyte solution 11 per unit time (seconds) exceeds 5%, the thickness profile peak ratio bias (BPTP) of the copper foil 200 may exceed 0.71 by non-uniform plating.

In order to maintain or improve the cleanliness of the electrolyte solution 11, hydrogen peroxide and air may be introduced into the electrolyte solution 11 while the electrolyte solution 11 is ozone-treated or the copper layer 110 is formed by electroplating.

Next, the copper layer 110 is cleaned in the cleaning tank 20.

For example, in order to remove impurities on the surface of the copper layer 110, water washing may be performed in the cleaning tank 20. Alternatively, acid cleaning may be performed to remove impurities on the surface of the copper layer 110, and then water cleaning may be performed to remove an acid solution used for pickling. The cleaning process may be omitted.

Next, antirust films 210 and 220 are formed on the copper layer 110.

Referring to FIG. 8, the copper layer 110 may be immersed in the rust preventive liquid 31 contained in the rust prevention tank 30, and the rust preventive layers 210 and 220 may be formed on the copper layer 110. Here, the rust preventive solution 31 may include chromium, and chromium (Cr) may exist in an ionic state in the rust preventive solution 31. The rust preventive solution 31 may comprise 0.5 to 5 g / L of chromium. The antirust films 210 and 220 formed as described above are also referred to as protective layers.

Meanwhile, the rust preventive films 210 and 220 may include a silane compound obtained by a silane treatment or a nitrogen compound obtained by a nitrogen treatment.

The copper foil 200 is made by the formation of the rust preventive films 210 and 220.

Next, the copper foil 200 is washed in the washing tank 40. This cleaning process can be omitted.

Next, after the drying process is performed, the copper foil 200 is wound on the winder WR.

Hereinafter, the present invention will be described in detail through examples and comparative examples. However, the following examples are merely to help understanding of the present invention, the scope of the present invention is not limited to these embodiments.

Example 1-7 and Comparative Example 1-7

Copper foil was manufactured using the electromechanical tank 10, the rotating electrode drum 12 arrange | positioned at the electrolytic cell 10, and the slicing machine containing the electrode plate 13 arrange | positioned apart from the rotating electrode drum 12. The electrolyte solution 11 was a copper sulfate solution, the copper ion concentration of the electrolyte solution 11 was 75g / L, the sulfuric acid concentration was 100g / L, and the temperature of the electrolyte solution 11 was maintained at 55 degreeC.

The rotating electrode drum 12 was polished by a brush having a particle size as shown in Table 1.

The electrolyte solution 11 contains 10 mg / L polyethylene glycol as an additive. In addition, the electrolyte solution 11 includes arsenic (As), oramin and citric acid (CA), the content of which is shown in Table 1. The electrolyte solution 11 is circulated at a flow rate of 42 m ³ / hour, and the flow rate variation per unit time (seconds) is as shown in Table 1.

A copper layer 110 was formed by applying a current density of 60 ASD between the rotating drum 12 disposed in the electrolyte solution 11 and the electrode plate 13. Next, the copper layer 110 was immersed in the rust preventive solution 31 contained in the rust prevention tank 30 to form the rust preventive films 210 and 220 including chromium on the surface of the copper layer 110. The temperature of the rust preventive liquid 31 was maintained at 30 ° C., and the rust preventive liquid 31 contained 2.2 g / L of chromium (Cr). As a result, copper foils of Examples 1-7 and Comparative Examples 1-7 were produced.

division Brush granularity (#) As (ppm) Oramine (ppm) CA (ppm) Flow rate deviation (% / sec) Example 1 3000 8 11 11 3 Example 2 2000 14 11 11 2.8 Example 3 2000 8 3 11 2.8 Example 4 2000 8 19 11 2.8 Example 5 2000 8 11 11 4.8 Example 6 2000 8 11 3 2.8 Example 7 2000 8 11 19 2.8 Comparative Example 1 4000 8 11 11 0.18 Comparative Example 2 2000 16 11 11 0.18 Comparative Example 3 2000 8 One 11 0.18 Comparative Example 4 2000 8 22 11 0.18 Comparative Example 5 2000 8 11 11 5.3 Comparative Example 6 2000 8 11 One 0.18 Comparative Example 7 2000 8 11 22 0.18

For copper foils of Examples 1-7 and Comparative Examples 1-7 thus prepared, (i) thickness profile peak ratio (PTP), (ii) thickness profile peak ratio bias (BPTP), (iii) half width (FWHM) ) Variation rate and (iv) texture coefficient [TC (220)] of (220) plane were measured. In addition, wrinkling, tearing and weeping occurred in the copper foil during the manufacturing process of the secondary battery using the copper foil. The results are shown in Table 2.

(i) Thickness Profile Peak Ratio (PTP)

The copper foils of Examples 1-7 and Comparative Examples 1-7 were cut to a size of 10 cm x 10 cm to measure the weight to obtain a weight per unit area thereof, and the copper foil was obtained using the density of copper (8.94 g / cm ³ ) and Formula 1 _Their thickness (T _copper ) was calculated.

In addition, using Mitutotyo's SJ-310 roughness meter, the measurement length excluding the cut off length is 4 mm, the initial and end cut off lengths are 0.8 mm, respectively, and the radius of the stylus tip ( Radius) was set to 2 µm and the measurement pressure of 0.75 mN, and the peak roughness Rp was measured.

Thickness profile peak ratio (PTP) of copper foil is calculated | required by following formula (1).

[Equation 1]

PTP = Rp / T _copper

(ii) thickness profile peak ratio bias (BPTP)

PTP is measured and averaged three times in three width directions (left L, center C, and right R) of the copper foil 100, and the average value of the lowest point is called PTPmin, and the average value of the highest point is The average of all nine PTP values measured at three points was called RRTmax. Next, the thickness profile peak ratio bias (BPTP) of the copper foil was measured using PTPmax, PTPmin, and PTPave according to the following Equation 2.

[Equation 2]

BPTP = (PTPmax-PTPmin) / PTPave

(iii) FWHM rate of change

First, the XRD graph of copper foil was obtained at normal temperature (25 degreeC +/- 15 degreeC). Specifically, the X-ray diffraction method (XRD) in the diffraction angle (2θ) range of 30 ° to 95 ° [(i) Target: Copper K alpha 1, (ii) 2θ interval: 0.01 °, (iii) 2θ scan speed: 3 ° / min], an XRD graph having peaks corresponding to n crystal planes was obtained. The full width (FWHM) before heat treatment of the (220) plane of the copper foil was measured from the XRD graph of the obtained copper foil. Next, after heat-processing copper foil for 30 minutes at 110 degreeC, the XRD graph of copper foil was calculated | required, and the half width (FWHM) after heat processing of the (220) surface of copper foil was measured from this. FWHM variation rate is calculated | required by following formula (3).

[Equation 3]

FWHM% change = (half-width after heat treatment) / (half-width before heat treatment)

(iv) Collective coefficient of surface (220) [TC (220)]

First, the X-ray diffraction method (XRD) in the diffraction angle (2θ) range of 30 ° to 95 ° [(i) Target: Copper K alpha 1, (ii) 2θ interval: 0.01 °, (iii) 2θ scan speed: 3 ° / min], an XRD graph having peaks corresponding to n crystal planes was obtained. Next, the XRD diffraction intensity [I (hkl)] of each crystal plane (hkl) was obtained from this graph. In addition, the XRD diffraction intensity [I ₀ (hkl)] for each of the n crystal planes of the standard copper powder defined by Joint Committee on Powder Diffraction Standards (JCPDS) was obtained. Subsequently, the arithmetic mean value of I (hkl) / I ₀ (hkl) of n crystal planes is obtained, and the (220) plane of copper foil is divided by dividing I (220) / I ₀ (220) of (220) plane by the calculated arithmetic mean value. The aggregated tissue coefficient [TC (220)] of was calculated. The texture coefficient [TC (220)] of the (220) plane was calculated based on the following equation (4).

[Equation 4]

(v) observation of wrinkles and tearing

1) cathode manufacturing

2 parts by weight of styrene butadiene rubber (SBR) and 2 parts by weight of carboxymethyl cellulose (CMC) were mixed with 100 parts by weight of commercially available carbon for negative electrode active material, and a slurry for negative electrode active material was prepared using distilled water as a solvent. A slurry for the negative electrode active material was applied to the copper foils of Example 1-7 and Comparative Example 1-7 having a width of 10 cm using a doctor blade at a thickness of 40 μm, dried at 120 ° C., and a pressure of 1 ton / cm 2. Pressurized to prepare a negative electrode for a secondary battery.

2) Manufacture of electrolyte

Solute LiPF ₆ was dissolved in a non-aqueous organic solvent in which ethylene carbonate (EC) and ethyl methyl carbonate (EMC) were mixed at a ratio of 1: 2 at a concentration of 1 M to prepare a basic electrolyte solution. A non-aqueous electrolyte was prepared by mixing 99.5 wt% of the basic electrolyte solution and 0.5 wt% of succinic anhydride.

 3) anode manufacturing

A lithium active material was prepared by mixing lithium manganese oxide of Li _1.1 Mn _1.85 Al _0.05 O ₄ and lithium manganese oxide of orthorhombic crystal structure of o-LiMnO ₂ in a ratio of 90:10 (weight ratio). The positive electrode active material, carbon black, and PVDF [Poly (vinylidenefluoride)] as a binder were mixed at 85: 10: 5 (weight ratio), and mixed with an organic solvent, NMP, to prepare a slurry. The slurry thus prepared was coated on both sides of a 20 μm thick Al foil and dried to prepare a positive electrode.

4) Production of test lithium secondary battery

A positive electrode and a negative electrode were disposed inside the aluminum can so as to be insulated from the aluminum can, and a nonaqueous electrolyte and a separator were disposed therebetween to prepare a coin-type lithium secondary battery. Polypropylene (Celgard 2325; thickness 25㎛, average poresize φ 28 nm, porosity 40%) was used as the separator.

5) Observe wrinkles, tears and crying

Wrinkles, tears, and weeping of copper foils were observed in a series of lithium secondary battery manufacturing. The case where wrinkles, tears or tears occurred was marked as "occurrence", and the case where it did not occur was marked as "good".

The above test and observation results are shown in Table 2 below.

PTP BPTP FWHM Change (220) cotton
Collective organization coefficient wrinkle Tearing weeping Example 1 0.02 0.34 0.99 0.89 Good Good Good Example 2 0.37 0.34 0.98 0.87 Good Good Good Example 3 0.19 0.33 0.79 0.86 Good Good Good Example 4 0.19 0.34 1.21 0.87 Good Good Good Example 5 0.18 0.71 0.99 0.86 Good Good Good Example 6 0.19 0.36 1.01 0.48 Good Good Good Example 7 0.20 0.35 1.01 1.28 Good Good Good Comparative Example 1 0.01 0.33 0.97 0.88 Occur Good Good Comparative Example 2 0.39 0.33 0.98 0.87 Good Occur Good Comparative Example 3 0.18 0.34 0.78 0.86 Occur Good Good Comparative Example 4 0.19 0.35 1.23 0.86 Occur Good Good Comparative Example 5 0.20 0.73 1.01 0.87 Occur Occur Occur Comparative Example 6 0.18 0.36 0.99 0.47 Occur Good Good Comparative Example 7 0.18 0.35 0.98 1.30 Good Occur Good

Wrinkles, tearing, or crying occurred in the process of manufacturing the lithium secondary battery using the copper foil according to Comparative Example 1-7, but the process of manufacturing the lithium secondary battery using the copper foil according to Example 1-7 No wrinkles, tears or crying occurred. As such, the thin film according to Example 1-7 has excellent reliability.

According to one embodiment of the present invention, crying (bagginess) refers to a state or a portion in which the copper foil 100 is not stretched flat due to local extension. Wrinkle refers to the state or portion of the copper foil 100 is locally folded. Table 2 of the present invention distinguished bagginess and wrinkles. However, since bagginess and wrinkle are identical in that they refer to uneven portions of a film, film or layer, they do not distinguish between them, but they do not distinguish between bagginess and wrinkle. They are all expressed as wrinkles.

Specifically, wrinkles or tearing occurred in the copper foil in the process of manufacturing the lithium secondary battery using the following copper foil.

(1) Comparative Example 1 (wrinkling), wherein the surface of the rotating electrode drum 12 was polished with a brush having a grain size (Grit) of more than # 3000, so that the PTP was less than 0.02;

(2) Comparative Example 2 in which the content of arsenic (As) in the electrolytic solution exceeded 15 ppm and the PTP exceeded 0.37 (breaking occurred);

(3) Comparative Example 3 (wrinkling), in which the content of oramin in the electrolyte solution was less than 2 ppm and the half-width (FWHM) variation rate was less than 0.79;

(4) Comparative Example 4 (wrinkle generation) in which the content of oramine in the electrolyte exceeded 20 ppm and the half-width variation exceeded 1.21;

(5) Comparative Example 5 (wrinkles, tears and crying occurred) in which the flow rate variation of the electrolyte solution exceeded 5% per second and the BPTP exceeded 0.71;

(6) Comparative Example 6 (wrinkling), wherein the content of citric acid (CA) was less than 2 ppm and the texture coefficient [TC (220)] of the (220) plane was less than 0.48;

(7) Comparative Example 7 in which the content of citric acid (CA) exceeds 20 ppm and the texture coefficient [TC (220)] of the (220) plane exceeds 1.28 (the occurrence of tearing).

The copper foil which concerns on such a comparative example 1-7 can be evaluated as unsuitable as the negative electrode electrical power collector for lithium secondary batteries.

On the other hand, the copper foils of Examples 1 to 7 manufactured in the range of the conditions according to the present invention did not tear during the manufacturing process of the lithium secondary battery, and no crying or wrinkles occurred on the copper foil. Therefore, the copper foil according to embodiments of the present invention has excellent roll-to-roll (RTR) processability and process reliability, and thus may be usefully used as a negative electrode current collector for a lithium secondary battery.

The present invention described above is not limited to the above-described embodiments and the accompanying drawings, and various substitutions, modifications, and changes can be made without departing from the technical details of the present invention. It will be apparent to those of ordinary skill in the art. Therefore, the scope of the present invention is expressed by the following claims, and it should be construed that all changes or modifications derived from the meaning, scope and equivalent concept of the claims are included in the scope of the present invention.

100, 200: copper foil
210, 220: antirust membrane
310: active material layer
300, 400: secondary battery electrode
340: negative electrode for a secondary battery
370: positive electrode for a secondary battery
MS: matte cotton
SS: Shiny cotton

Claims (15)

A copper layer,
Proportion of Thickness to Profile peak height (PTP) from 0.02 to 0.37;
Bias for Proportion of Thickness to Profile peak height (BPTP); And
Full Width at Half Maximum (FWHM) variation rate of 0.79 to 1.21;
Copper foil having:
Here, the thickness profile peak ratio (PTP) is obtained by Equation 1 below.
[Equation 1]
PTP = Rp / T _copper
In Formula 1, Rp is the peak roughness of the _copper foil, T _copper is the thickness of the _copper foil,
The thickness profile peak ratio bias (BPTP) is obtained by Equation 2 below.
[Equation 2]
BPTP = (PTPmax --TPmin) / PTPave
In Equation 2, PTPmax is the maximum value of the thickness profile peak ratio (PTP), PTPmin is the minimum value of the thickness profile peak ratio (PTP), PTPave is the average value of the thickness profile peak ratio (PTP),
The FWHM fluctuation rate is obtained by the following Equation 3.
[Equation 3]
Half-width variation = (half-width after heat treatment) / (half-width before heat treatment)
The half width after the heat treatment in Equation 3 indicates the half width (FWHM) of the (220) surface of the copper foil after the heat treatment at 110 ° C. for 30 minutes, and the half width before the heat treatment is the (220) of the copper foil before the heat treatment at 110 ° C. for 30 minutes. The half width (FWHM) of the plane is shown. The method of claim 1,
At room temperature (25 ± 15 ℃), the texture coefficient [TC (220)] of the (220) plane is copper foil of 0.48 to 1.28. The method of claim 1,
Copper foil with maximum height roughness (Rmax) of 0.6 to 3.5 μm. The method of claim 1,
Copper foil with a weight deviation of 3% or less. The method of claim 1,
Copper foil which further contains the antirust film arrange | positioned on the said copper layer. The method of claim 5,
The rust preventive film is a copper foil containing at least one of chromium (Cr), a silane compound and a nitrogen compound. Copper foil according to any one of claims 1 to 6; And
An active material layer disposed on the copper foil;
Secondary battery electrode comprising a. A cathode;
An anode disposed opposite the anode;
An electrolyte disposed between the anode and the cathode to provide an environment in which lithium ions may move; And
And a separator for electrically insulating the anode and the cathode.
The negative electrode,
Copper foil according to any one of claims 1 to 6; And
An active material layer disposed on the copper foil;
Secondary battery comprising a. Polymer membranes; And
Copper foil according to any one of claims 1 to 6, disposed on the polymer film;
Flexible copper foil laminated film comprising a. And conducting an electrode plate and a rotating electrode drum disposed apart from each other in an electrolyte solution containing copper ions at a current density of 40 to 80 A / dm ² to form a copper layer.
The electrolyte solution,
70 to 90 g / L of copper ions;
50 to 150 g / L sulfuric acid; And
Arsenic (As) of 15 ppm or less;
Manufacturing method of copper foil containing. The method of claim 10,
The electrolytic solution is a method for producing a copper foil containing 2 to 20 ppm oramin (auramine). The method of claim 10,
The said electrolytic solution is a manufacturing method of the copper foil containing 2-20 ppm citric acid. The method of claim 10,
Before forming the copper layer, polishing the surface of the rotating electrode drum with a brush having a particle size of # 800 to # 3000. The method of claim 10,
The electrolyte solution is a copper foil manufacturing method circulated at a flow rate of 39 to 46m ³ / hour. The method of claim 14,
Flow rate variation of the electrolyte is 5% or less per unit time (second, second) manufacturing method of copper foil.

Images