KR102518398B1 - Copper foil with high stability, electrode comprisng the same, secondary battery comprising the same and method for manufacturing the same - Google Patents

Abstract

An embodiment of the present invention includes a copper layer and 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, and a full width at half maximum (FWHM) variation of 0.79 to 1.21. Provide copper foil.

Description

High-reliability copper foil, electrode including the same, secondary battery including the same, and manufacturing method thereof

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

Copper foil is used to manufacture various products such as anodes of secondary batteries and flexible printed circuit boards (FPCB).

Among these, copper foil manufactured by electroplating is also referred to as electrodeposited copper foil. Such copper foil is generally manufactured through a roll-to-roll (RTR) process, and is also used in the manufacture of a negative electrode of a secondary battery, a flexible printed circuit board (FPCB), and the like through a roll-to-roll (RTR) process. Since continuous production is possible, the roll-to-roll (RTR) process is known as a process suitable for mass production of products. Since copper foil has a thin thickness, if production conditions are not precisely controlled when manufacturing copper foil or products using copper foil, the copper foil may be torn or wrinkles may occur in the electrodeposited copper foil. In this case, since the process equipment must be stopped and the equipment must be restarted after resolving the problems, productivity is lowered.

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

When tears or wrinkles occur in the copper foil manufacturing process as shown in FIG. 9, or when wrinkles or tears occur in the copper foil in the process of manufacturing a secondary battery using copper foil, stable product production becomes difficult, and product manufacturing yield This decline becomes a factor in increasing the manufacturing cost of the product.

Among the causes of wrinkles and tear defects occurring in the manufacturing process of products using copper foil, for example, secondary batteries, a method of controlling the weight variation of copper foil to a low level is known as a method of solving the cause caused by copper foil. . However, there is a limit to solving the problem of wrinkles and tears occurring in the secondary battery manufacturing process only by controlling the weight variation of the copper foil. In particular, as the ratio of ultra-thin copper foil, for example, copper foil having a thickness of 8 μm or less, is used as an anode current collector to increase the capacity of a secondary battery, even if the weight deviation of the copper foil is precisely controlled, the secondary battery Wrinkles and tear defects occur intermittently in the manufacturing process of Therefore, it is necessary to prevent or suppress the occurrence of wrinkles or tears in the copper foil in the manufacturing process of the secondary battery.

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

One embodiment of the present invention is to provide a copper foil with minimized wrinkles or tears. In particular, one embodiment of the present invention is to provide a copper foil having excellent processability and reliability by preventing wrinkles, tears, and crying in the manufacturing process of a secondary battery, even if 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 including such a secondary battery electrode.

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

Another embodiment of the present invention is to provide a method for manufacturing a copper foil with improved reliability by preventing wrinkles, tears, or cries during the manufacturing process.

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

In order to solve these problems, an embodiment of the present invention includes a copper layer, a thickness profile peak ratio of 0.02 to 0.37 (Proportion of Thickness to Profile peak height, PTP), a thickness profile peak ratio bias of 0.71 or less ( Provided is a copper foil having a Bias for Proportion of Thickness to Profile peak height (BPTP) and a Full Width at Half Maximum (FWHM) variation 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), and PTPave is the average value of the thickness profile peak ratio (PTP).

The full width at half maximum (FWHM) fluctuation rate is obtained by Equation 3 below,

[Equation 3]

Rate of change in half width = (half width after heat treatment)/(half width before heat treatment)

In Equation 3, the half width after heat treatment represents the half width (FWHM) of the (220) surface of the copper foil after heat treatment at 110 ° C. for 30 minutes, and the half width before heat treatment is the half width of the copper foil before heat treatment at 110 ° C. for 30 minutes (220 ) represents the full width at half maximum (FWHM) of the plane.

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

The copper foil has a maximum height roughness (Rmax) of 0.6 to 3.5 μm.

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

The copper foil further includes an anti-rust film disposed on the copper layer.

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

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

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

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

In another embodiment of the present invention, an electrode plate (anode) and a rotating electrode drum (cathode) disposed spaced apart from each other in an electrolyte solution containing copper ions are energized at a current density of 40 to 80 A/dm ² to form a copper layer. Including the step of forming, wherein the electrolyte solution provides a method for manufacturing a copper foil containing copper ions of 70 to 90 g / L, sulfuric acid of 50 to 150 g / L and arsenic (As) of 15 ppm or less.

The electrolyte solution contains 2 to 20 ppm of auramine.

The electrolyte solution contains 2 to 20 ppm of citric acid.

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

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

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

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

The copper foil according to an embodiment of the present invention has excellent resistance to wrinkles or tears, and wrinkles, tears, or cries are prevented during the manufacturing process of the copper foil or the manufacturing process of a secondary battery using the copper foil. Accordingly, stable product production is possible, and product manufacturing yield is improved, thereby preventing an increase in manufacturing cost of the product and improving product reliability.

In addition, the copper foil according to an embodiment of the present invention has excellent roll-to-roll (RTR) processability, and according to another embodiment of the present invention, an electrode for a secondary battery in which wrinkles, tears, or crying is prevented or minimized can be manufactured there is.

The accompanying drawings are intended to aid understanding of the present invention and constitute a part of this specification, illustrate embodiments of the present invention, and explain the principles of the present invention together with the detailed description of the present invention.
1 is a schematic cross-sectional view of a copper foil according to an embodiment of the present invention.
2A is an example of a graph of a surface roughness profile, and FIG. 2B is an example of an XRD graph of a 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.
Figure 8 is a schematic diagram of a manufacturing process of the copper foil shown in Figure 3.
9 is a photograph of a state where tearing has occurred in the copper foil.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

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 present invention includes all modifications and variations within the scope of the invention described in the claims and equivalents thereof.

The shape, size, ratio, angle, number, etc. disclosed in the drawings to describe the embodiments of the present invention are exemplary, and the present invention is not limited by the details shown in the drawings. Like elements may be referred to by like reference numerals throughout the specification.

When 'includes', 'has', 'consists of', etc. mentioned in this specification is 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 the components, even if there is no separate explicit description, it is interpreted as including the error range.

In the case of a description of a positional relationship, for example, 'on top of', 'on top of', 'at the bottom of', 'next to', etc. Or, unless the word 'directly' is used, one or more other parts may be located between the two parts.

In the case of a description of a temporal relationship, for example, 'immediately' or 'directly' when a temporal precedence relationship is described in terms of 'after', 'following', 'next to', 'before', etc. Unless the expression is used, non-continuous cases may also be included.

Expressions such as 'first', 'second', etc. are used to describe various components, 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 also be the second component within the technical spirit of the present invention.

The term “at least one” should be understood to include all possible combinations from one or more related items.

Each feature of the various embodiments of the present invention can be partially or entirely combined or combined with each other, technically various interlocking and driving are possible, and each embodiment can be implemented independently of each other or can be implemented together in a related relationship. 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 one embodiment of the present invention, the copper foil 100 may further include a rust-prevention film 210 disposed on the copper layer 110 . The anti-rust film 210 may be omitted.

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

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

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

The anti-rust film 210 protects the copper layer 110 . The anti-rust film 210 can prevent the copper layer 110 from being oxidized or deteriorated during preservation. Therefore, the anti-rust film 210 is also referred to as a protective layer.

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

For example, the anti-rust film 210 may be made by using an anti-rust liquid containing chromium (Cr), that is, a anti-rust liquid containing a chromic acid compound.

According to one embodiment of the present invention, the copper foil 100 has a first surface S1 that is a surface in the direction of the mat surface (MS) and a second surface that is a surface in the direction of the shiny surface (SS) with respect to the copper layer 110. (S2). In FIG. 1 , the first surface S1 of the copper foil 100 is the surface of the anti-rust film 210, and the second surface S2 is the shiny surface SS. When the anti-rust film 210 is not disposed on the copper layer 110, the matte surface MS of the copper layer 110 becomes the first surface S1 of the copper foil 100.

According to one embodiment of the present invention, the copper foil 100 has a thickness profile peak ratio (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 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.

According to one embodiment of the present invention, "peak roughness (Rp)" may be measured with a roughness meter according to the JIS B 0601-2001 standard. For example, the peak roughness (Rp) may be measured with a roughness meter (SJ-310) manufactured by Mitutotyo. Specifically, using Mitutotyo's SJ-310 roughness meter, the measurement length excluding the cut-off length was 4 mm, the initial and final cut-off lengths were each 0.8 mm, and the stylus tip (Stylus The Rp value can be measured after setting the radius of Tip) to 2㎛ and the measurement pressure to 0.75mN. The value measured in this way corresponds to the peak roughness (Rp) based on the measured value of the Mitutoyo illuminance meter.

2A is an example of a graph of a surface roughness profile. As shown in FIG. 2A, the 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 10 cm x 10 cm is C g, considering that the density of copper is 8.94 g / cm ³ , the thickness of the copper foil 100 is obtained according to the following formula 1 it can be done

[Calculation 1]

If the thickness profile peak ratio (PTP) is less than 0.02, the surface profile of the copper foil 100 is low, and wrinkles due to slip may occur in the manufacturing process of a product using the copper foil 100, for example, a secondary battery. When the thickness profile peak ratio (PTP) exceeds 0.37, the profile to the thickness of the copper foil 100 is high, and in the process of manufacturing a secondary battery by the Roll to Roll process, a relatively high surface profile to the thickness is notched ( It acts as a notch, and tearing may occur in the copper foil 100.

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

The thickness profile peak ratio shift (BPTP) of the copper foil 100 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), and PTPave is the average value of the thickness profile peak ratio (PTP).

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

If the thickness profile peak ratio bias (BPTP) exceeds 0.71, due to the difference in the local thickness profile peak ratio, copper foil (100 ) tear or crease 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 full width at half maximum (FWHM) rate of change is obtained by Equation 3 below.

[Equation 3]

Rate of change in half width = (half width after heat treatment)/(half width before heat treatment)

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

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

2B is an example of an XRD graph of copper foil. Referring to Figure 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°/min], an XRD graph having peaks corresponding to n crystal planes can be obtained. From the XRD graph of the obtained copper foil 100, the full width at half maximum (FWHM) of the (220) plane of the copper foil 100 is measured. The full width at half maximum (FWHM) can be obtained from the software of the X-ray diffraction analysis (XRD) instrument.

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

According to one 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 surface of the copper foil 100.

Hereinafter, a method of measuring and calculating the texture coefficient [TC(220)] of the (220) plane of copper foil will be described with reference to FIG. 2B.

Referring to FIG. 2B, first, X-ray diffraction analysis (XRD) in the diffraction angle (2θ) range of 30 ° to 95 ° [Target: Copper K alpha 1, 2θ interval: 0.01 °, 2θ scan speed: 3 ° / min ], an XRD graph having peaks corresponding to n crystal planes is obtained. 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 can 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 specified by the Joint Committee on Powder Diffraction Standards (JCPDS) is obtained. Subsequently, the arithmetic average value of I(hkl)/I ₀ (hkl) of the n crystal planes is calculated, and the arithmetic average value is divided by I(220)/I ₀ (220) of the (220) plane to (220) plane. The texture coefficient [TC (220)] of is calculated. Specifically, the texture coefficient [TC(220)] of the (220) plane is calculated based on the following Equation 4.

[Equation 4]

According to one embodiment of the present invention, the (220) surface of each of the first and second surfaces S1 and 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, so that the copper foil 100 wrinkles occur. If the coefficient of the texture of the (220) plane exceeds 1.28, 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 difficulties in stable product production. there is.

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

The maximum height roughness (Rmax) may be measured with a roughness meter according to the JIS B 0601-2001 standard. For example, the maximum height roughness (Rmax) can be measured by the Mitutoyo SJ-310 model. Specifically, the measurement length excluding the cut off length is 4 mm, the initial and final cut off lengths are each 0.8 mm, the radius of the stylus tip is 2 μm, and the measurement pressure is 0.75 mN. After setting to , the Rmax value can be obtained by measuring. The value measured in this way corresponds to the maximum height roughness (Rmax) of the Mitutoyo roughness meter measurement standard.

If the maximum height roughness (Rmax) of the copper foil 100 is less than 0.6 μm, the surface of the copper foil 100 may not have enough active sites where the active material can be coated, so the active material may not be bonded to the copper foil 100 with a sufficiently strong bonding force. there is. Accordingly, peeling of the active material may occur on the surface of the copper foil 100 .

If 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 non-uniformity of the surface of the copper foil 100 .

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

The weight deviation is calculated by measuring the weight of each sample after taking samples of 10 cm x 10 cm from three points arranged along the width direction of the copper foil 100, that is, TD (Transverse Direction), It can be obtained by calculating the "average weight of three points" and the "standard deviation of weight" from the weight per unit area of the three samples. The weight deviation can be obtained by Equation 5 below.

[Equation 5]

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

Also, according to one embodiment of the present invention, the copper foil 100 may have a thickness of 4 μm to 30 μm. When the thickness of the copper foil 100 is less than 4 μm, workability is reduced in the process of manufacturing a secondary battery electrode or a secondary battery using the copper foil 100 . When the thickness of the copper foil 100 exceeds 30 μm, the thickness of the secondary battery electrode using the copper foil 100 increases, and this large thickness may cause difficulties in implementing a high capacity secondary battery.

3 is a schematic cross-sectional view of a copper foil 200 according to another embodiment of the present invention. Hereinafter, descriptions of components already described are omitted to avoid redundancy.

Referring to FIG. 3 , the copper foil 200 according to another embodiment of the present invention includes a copper layer 110 and two anti-rust surfaces disposed on the matte surface MS and the shiny surface SS of the copper layer 110, respectively. It includes 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 anti-rust film 220 disposed on the shiny surface SS of the copper layer 110 .

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

The first surface S2 of the copper foil 200 shown in FIG. 3 is the surface of the anti-rust film 210 disposed on the mat surface MS, and the second surface S2 is disposed on the shiny surface SS. It is the surface of the film 220.

According to another embodiment of the present invention, each of the two anti-rust films 210 and 220 may 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 deviation (BPTP) of 0.71 or less, a full width at half maximum (FWHM) variation of 0.79 to 1.21, and a variation of 0.6 to 3.5 μm. It has a maximum height roughness (Rmax) and a weight deviation of less than 3%.

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 an electrode 300 for a secondary battery according to another embodiment of the present invention.

Referring to FIG. 4 , an electrode 300 for a secondary battery 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 . The secondary battery electrode 300 shown in FIG. 4 may be applied to, for example, the secondary battery 500 shown in FIG. 6 .

A 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 shown in FIG. 4, but 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, respectively, and the active material layer 310 is provided only on the second surface S2 of the copper foil 100. may be placed.

Specifically, the electrode 300 for a secondary battery according to another embodiment of the present invention includes a copper foil 100 having a first surface S1 and a second surface S2 and a 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 a current collector. However, another embodiment of the present invention is not limited thereto, and the copper foil 200 shown in FIG. 3 may be used as a current collector of the electrode 300 for a secondary battery.

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 an anode current collector or an anode 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 an anode active material. For example, the secondary battery electrode 300 shown 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 a metal, and a composite of metal and carbon. As the metal, at least one of Ge, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe may be used. Also, 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 wrinkles of the copper foil 100 are prevented during the manufacturing process of the electrode 300 for a secondary battery. Accordingly, the manufacturing efficiency of the secondary battery electrode 300 may be improved, and the charge/discharge efficiency and capacity retention rate of the secondary battery including the secondary battery electrode 300 may be improved.

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

An electrode 400 for a secondary battery according to another embodiment of the present invention includes a copper foil 200 and 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 anti-rust films 210 and 220 disposed on both sides of the copper layer 110 .

In addition, the secondary battery electrode 300 shown in FIG. 5 includes two active material layers 310 and 320 disposed on both sides 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 the first active material layer, and the active material layer 320 disposed on the second surface S2 of the copper foil 200 It may be referred to as the second active material layer.

The two active material layers 310 and 320 may be made of the same material using the same method, or may be made of different materials or 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 shown in FIG. 6 is, for example, a lithium secondary battery.

Referring to FIG. 6, the secondary battery 500 has a cathode 370, an anode 340 opposite to the cathode 370, and ions between the anode 370 and the cathode 340. An electrolyte 350 providing a movable environment and a separator 360 electrically insulating the anode 370 and the cathode 340 are included. Here, ions moving between the positive electrode 370 and the negative electrode 340 are lithium ions. The separator 360 separates the positive electrode 370 and the negative electrode 340 to prevent charges generated from one electrode from moving to the other electrode through the inside of the secondary battery 500 and being useless. Referring to FIG. 6 , a separator 360 is disposed within an electrolyte 350 .

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

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

As the negative 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 shown in FIGS. 4 and 5 may be used as the negative electrode 340 of the secondary battery 500 shown in FIG. 6 .

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

The flexible copper clad laminated film 600 according to another embodiment of the present invention includes a polymer film 410 and the copper foil 100 disposed on the polymer film 410 . Although the flexible copper clad laminated film 600 including the copper foil 100 shown in FIG. 1 is shown 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 clad laminated film 600 shown in FIG. 7 .

The polymer film 410 has flexibility and non-conductivity. The type of polymer film 410 is not particularly limited. The polymer film 410 may include, for example, polyimide. The flexible copper clad laminated film 600 may be made by laminating the polyimide film and the copper foil 100 through a roll press. Alternatively, after the polyimide precursor solution is coated on the copper foil 100, the flexible copper clad laminated film 600 may be made by heat treatment.

The copper foil 100 includes a copper layer 110 having a matte surface MS and a shiny surface SS, and an anticorrosive film disposed on at least one of the matte surface MS and the shiny surface SS of the copper layer 110 ( 210). Here, the anti-rust film 210 may be omitted.

Referring to FIG. 7 , the arrangement of the polymer film 410 on the anti-rust film 210 is exemplified, but another embodiment of the present invention is not limited thereto. A polymer film 410 may be disposed on the shiny surface SS of the copper layer 110 .

Hereinafter, with reference to FIG. 8, a manufacturing method of copper foil 200 according to another embodiment of the present invention will be described in detail.

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 disposed 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 ) to form a copper layer 110 ) to form

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 15 ppm or less of arsenic (As). Here, arsenic (As) includes arsenic ions in a dissociated state in the electrolyte 11 .

In the electrolyte 11, arsenic (As) corresponds to an impurity, and the concentration of arsenic (As) is managed to 15 ppm or less. When the concentration of arsenic (As) in the electrolyte 11 exceeds 15 ppm, the peak roughness (Rp) of the copper foil 200 rises so that the thickness profile peak ratio (PTP) of the copper foil 200 exceeds 0.37. . This phenomenon becomes more severe when the thickness of the copper foil 200 is 6 μm or less.

In order to adjust the concentration of arsenic (As) in the electrolyte 11 to 15 ppm or less, a raw material that does not contain arsenic (As) is used, or arsenic (As) is added to the electrolyte during the formation process of the copper layer 110 by plating. (11) Make sure that it does not flow into the interior. In order to maintain the concentration of arsenic (As) in the electrolyte 11 below 15 ppm, chlorine (Cl) is added to the electrolyte 11 so that arsenic (As) is precipitated 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.

Auramine may be represented by Formula 1 below.

[Formula 1]

According to one embodiment of the present invention, the variation rate of the full width at half maximum (FWHM) of the (220) plane of the copper foil 100 can be controlled by the type and concentration of the additive. In particular, the copper foil 200 The rate of change of the full width at half maximum (FWHM) of the (220) plane of can be adjusted. When the concentration of auramine is less than 2 ppm, the rate of change of the full width at half maximum (FWHM) of the copper foil 200 is less than 0.79, and when the concentration of auramine is greater than 20 ppm, the rate of change of the full width at half maximum (FWHM) of the copper foil 200 is 1.21 Wrinkles may be generated in the copper foil 200 in excess of .

As another additive, citric acid (CA) may 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 brightener.

If the concentration of citric acid (CA) in the electrolyte 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. Conversely, 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 becomes 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 11 contained in the electrolytic cell 10 are 40 to 80 ASD (A / dm ² ) The copper layer 110 may be formed by electrodepositing copper on the rotary electrode drum 12 by being energized at a current density of . The gap 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, the lower the surface roughness of the matte surface MS of the copper layer 110, and the lower the current density. 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 control the surface roughness of the shiny surface SS, the surface of the rotating electrode drum 12 may be polished with a brush having a grit of #800 to #3000 before forming the copper layer 110, for example. there is. For example, when 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 °C.

In order to reduce the content of impurities in the electrolyte 11, a copper wire serving as a material for copper ions is heat-treated, and after the heat-treated copper wire is pickled, the pickled copper wire may be put 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 process of the electrolyte 11 , the electrolyte 11 is filtered, and solid impurities present in the electrolyte 11 may be removed while electroplating for forming the copper layer 110 is performed. By filtering the electrolyte 110, for example, by removing arsenic chloride (AsClx), the content of arsenic (As) in the electrolyte 11 may be maintained at 15 ppm or less.

If the flow rate of the electrolyte 11 is less than 39 m ³ /hour, the flow rate is low and overvoltage may occur and the copper layer 110 may be non-uniformly formed. On the other hand, if the flow rate exceeds 46 m ³ /hour, foreign substances may flow into the electrolyte 11 due to damage to the filter.

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 11 per unit time (second) may be managed to 5% or less. When the flow rate deviation of the electrolyte 11 per unit time (second) exceeds 5%, the non-uniform copper layer 110 may be formed by non-uniform plating, and accordingly, the weight deviation of the copper foil 200 increases. can do.

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

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

Next, the copper layer 110 is cleaned in the cleaning bath 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, followed by water cleaning to remove an acidic solution used for pickling. A 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 anti-rust solution 31 contained in the anti-rust bath 30, and thus the anti-rust films 210 and 220 may be formed on the copper layer 110. Here, the anti-rust liquid 31 includes chromium, and chromium (Cr) may exist in an ionic state in the anti-rust liquid 31 . The anti-rust solution 31 may contain 0.5 to 5 g/L of chromium. The anti-rust films 210 and 220 thus formed are also referred to as protective layers.

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

The copper foil 200 is made by forming the anti-rust films 210 and 220 .

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

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

Hereinafter, the present invention will be specifically described through Examples and Comparative Examples. However, the following examples are only for helping understanding of the present invention, and the scope of the present invention is not limited to these examples.

Example 1-7 and Comparative Example 1-7

Copper foil was manufactured using a stripping machine including an electrolytic bath 10, a rotating electrode drum 12 disposed in the electrolytic bath 10, and an electrode plate 13 disposed spaced 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 75 g/L, the sulfuric acid concentration was 100 g/L, and the temperature of the electrolyte solution 11 was maintained at 55°C.

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

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

A current density of 60 ASD was applied between the rotary drum 12 and the electrode plate 13 disposed in the electrolyte 11 to form the copper layer 110 . Next, the copper layer 110 was immersed in the antirust liquid 31 contained in the antirust bath 30 to form anticorrosive films 210 and 220 containing chromium on the surface of the copper layer 110 . The temperature of the anti-rust liquid 31 was maintained at 30°C, and the anti-rust 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 manufactured.

division Brush granularity (#) As (ppm) Auramine (ppm) CA (ppm) Flow 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 the copper foils of Examples 1-7 and Comparative Examples 1-7 prepared as described above, (i) thickness profile peak ratio (PTP), (ii) thickness profile peak ratio bias (BPTP), (iii) full width at half maximum (FWHM) ) and (iv) the texture coefficient [TC(220)] of the (220) plane was measured. In addition, wrinkles, tears, and cries generated in the copper foil during the manufacturing process of the secondary battery using the copper foil were observed. The results are disclosed in Table 2.

(i) Thickness Profile Peak Ratio (PTP)

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

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

The thickness profile peak ratio (PTP) of the copper foil is obtained by Equation 1 below.

[Equation 1]

PTP = Rp/T _copper

(ii) Thickness Profile Peak Ratio Bias (BPTP)

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

[Equation 2]

BPTP = (PTPmax - PTPmin)/PTPave

(iii) FWHM change rate

First, an XRD graph of copper foil was obtained at room temperature (25°C ± 15°C). Specifically, X-ray diffraction (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 at half maximum (FWHM) of the (220) plane of the copper foil before heat treatment was measured from the XRD graph of the obtained copper foil. Next, after heat-treating the copper foil at 110 ° C. for 30 minutes, an XRD graph of the copper foil was obtained, and from this, the full width at half maximum (FWHM) after heat treatment of the (220) surface of the copper foil was measured. The full width at half maximum (FWHM) fluctuation rate is obtained by Equation 3 below.

[Equation 3]

Fluctuation rate of half width (FWHM) = (half width after heat treatment) / (half width before heat treatment)

(iv) Texture factor of (220) plane [TC(220)]

First, X-ray diffraction (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 specified by the Joint Committee on Powder Diffraction Standards (JCPDS) was obtained. Subsequently, the arithmetic average of I(hkl)/I ₀ (hkl) of the n crystal planes is calculated, and then I(220)/I ₀ (220) of the (220) plane is divided by the obtained arithmetic average value to (220) plane of the copper foil. The texture 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) Observe the occurrence of wrinkles, tears and crying

1) Cathode manufacturing

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

2) Manufacture of electrolyte solution

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

3) Anode manufacturing

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

4) Production of lithium secondary battery for testing

Inside the aluminum can, a positive electrode and a negative electrode are disposed so as to be insulated from the aluminum can, and a non-aqueous electrolyte and a separator are disposed therebetween to prepare a coin-type lithium secondary battery. Polypropylene (Celgard 2325; thickness 25㎛, average poresize φ28 nm, porosity 40%) was used as the separator.

5) Observe the occurrence of wrinkles, tears and crying

During the manufacturing process of a series of lithium secondary batteries, wrinkles, tears, and cries of copper foil were observed. A case where wrinkles, tears or weeping occurred was marked as "Occurred", and a case where it did not occur was marked as "Good".

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

PTP BPTP Full width at half maximum (FWHM) rate of change (220) cotton
texture factor wrinkle tear 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 generation Good Good Comparative Example 2 0.39 0.33 0.98 0.87 Good generation Good Comparative Example 3 0.18 0.34 0.78 0.86 generation Good Good Comparative Example 4 0.19 0.35 1.23 0.86 generation Good Good Comparative Example 5 0.20 0.73 1.01 0.87 generation generation generation Comparative Example 6 0.18 0.36 0.99 0.47 generation Good Good Comparative Example 7 0.18 0.35 0.98 1.30 Good generation Good

In the process of manufacturing a lithium secondary battery using the copper foil according to Comparative Example 1-7, wrinkles, tears or crying occurred in the copper foil, but in the process of manufacturing a lithium secondary battery using the copper foil according to Example 1-7, the copper foil No wrinkles, tears or weeping occurred. As such, the thin films according to Examples 1-7 have excellent reliability.

According to one embodiment of the present invention, bagginess refers to a state or a portion thereof in which the copper foil 100 is not flattened due to local stretching. A wrinkle refers to a state or a portion thereof in which the copper foil 100 is locally folded. In Table 2 of the present invention, bagginess and wrinkles were distinguished. However, since bagginess and wrinkles are identical in that they refer to non-flat areas in a certain film, film or layer, we do not differentiate between them and use bagginess and wrinkle. All of them are also expressed as wrinkles.

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

(1) Comparative Example 1 in which the surface of the rotating electrode drum 12 was polished with a brush having a grit greater than #3000, and the PTP was less than 0.02 (wrinkling);

(2) Comparative Example 2 in which the arsenic (As) content in the electrolyte exceeds 15 ppm and the PTP exceeds 0.37 (tear occurs);

(3) Comparative Example 3 in which the content of auramine in the electrolyte solution is less than 2 ppm and the full width at half maximum (FWHM) fluctuation rate is less than 0.79 (wrinkling);

(4) Comparative Example 4 in which the content of auramine in the electrolyte exceeds 20 ppm and the rate of change at half maximum exceeds 1.21 (wrinkles);

(5) Comparative Example 5 in which the flow rate deviation of the electrolyte exceeds 5% per second and the BPTP exceeds 0.71 (wrinkles, tears, and crying);

(6) Comparative Example 6 in which the content of citric acid (CA) is less than 2 ppm and the texture coefficient [TC (220)] of (220) cotton is less than 0.48 (wrinkling);

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

The copper foil according to Comparative Examples 1-7 may be evaluated as unsuitable for a negative current collector for a lithium secondary battery.

On the other hand, the copper foils of Examples 1 to 7 manufactured within the range of conditions according to the present invention were not torn during the manufacturing process of the lithium secondary battery, and no weeping or wrinkles were generated in the copper foil. Therefore, the copper foil according to the embodiments of the present invention has excellent roll-to-roll (RTR) processability and process reliability, and can be usefully used as an anode current collector for a lithium secondary battery.

The present invention described above is not limited by the foregoing embodiments and the accompanying drawings, and various substitutions, modifications, and changes are possible within the scope of the technical details of the present invention. will be clear to those skilled in the art. Therefore, the scope of the present invention is expressed by the following claims, and all changes or modifications derived from the meaning, scope and equivalent concepts of the claims should be construed as being included in the scope of the present invention.

100, 200: copper foil
210, 220: anti-rust film
310: active material layer
300, 400: electrode for secondary battery
340: negative electrode for secondary battery
370: anode for secondary battery
MS: matte side
SS: if it's shiny

Claims (15)

It contains a copper layer,
a Proportion of Thickness to Profile peak height (PTP) of 0.02 to 0.37;
a Bias for Proportion of Thickness to Profile peak height (BPTP) of 0.71 or less; and
Full Width at Half Maximum (FWHM) change 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 Equation 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 - 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 full width at half maximum (FWHM) fluctuation rate is obtained by Equation 3 below,
[Equation 3]
Rate of change in half width = (half width after heat treatment)/(half width before heat treatment)
In Equation 3, the half width after heat treatment represents the half width (FWHM) of the (220) surface of the copper foil after heat treatment at 110 ° C. for 30 minutes, and the half width before heat treatment is the half width of the copper foil before heat treatment at 110 ° C. for 30 minutes (220 ) represents the full width at half maximum (FWHM) of the plane. According to claim 1,
At room temperature (25 ± 15 ℃), the texture coefficient [TC (220)] of the (220) plane is 0.48 to 1.28 copper foil. According to claim 1,
Copper foil having a maximum height roughness (Rmax) of 0.6 to 3.5 μm. According to claim 1,
Copper foil having a weight variation of 3% or less. According to claim 1,
Copper foil further comprising a rust-preventive film disposed on the copper layer. According to claim 5,
The rust-preventive film includes at least one of chromium (Cr), a silane compound, and a nitrogen compound. The copper foil according to any one of claims 1 to 6; and
an active material layer disposed on the copper foil;
An electrode for a secondary battery comprising a. cathode;
a cathode disposed opposite to the anode;
an electrolyte disposed between the positive electrode and the negative electrode to provide an environment in which lithium ions can move; and
Including; a separator that electrically insulates the anode and the cathode;
The cathode is
The copper foil according to any one of claims 1 to 6; and
an active material layer disposed on the copper foil;
A secondary battery comprising a. polymer membrane; and
The copper foil according to any one of claims 1 to 6 disposed on the polymer film;
A flexible copper clad laminated film comprising a. Forming a copper layer by conducting an anode and a rotating electrode drum (cathode) spaced apart from each other in an electrolyte solution containing copper ions at a current density of 40 to 80 A/dm ² ,
The electrolyte is
70 to 90 g/L copper ions;
50 to 150 g/L sulfuric acid; and
8 ppm to 15 ppm arsenic (As);
Method for manufacturing a copper foil comprising a. According to claim 10,
The electrolyte solution is a method of manufacturing a copper foil containing 2 to 20 ppm of auramine. According to claim 10,
The method of manufacturing copper foil, wherein the electrolyte solution contains 2 to 20 ppm of citric acid. According to claim 10,
and polishing the surface of the rotating electrode drum with a brush having a particle size of #800 to #3000 before the step of forming the copper layer. According to claim 10,
The method of manufacturing a copper foil in which the electrolyte is circulated at a flow rate of 39 to 46 m ³ /hour. According to claim 14,
The flow rate deviation of the electrolyte is 5% or less per unit time (second, second).

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