KR20190023382A - Method for manufacturing copper foil having nodule layer, copper foil manufactured by the method, electrode for secondary battery the same and secondary battery - Google Patents

Abstract

An embodiment of the present invention provides a manufacturing method for copper foil, including: a step of forming a copper layer; and a step of forming a nodular layer on the copper layer, wherein the step of forming the nodular layer includes: a step of preparing a plating solution including 7-10 g/L of copper ion, 90-120 g/L of sulfuric acid, and 13-17 g/L of metal ion; and a step of dipping the copper layer into the plating solution and applying an electric current between plating electrode spaced apart from the copper layer to be provided in the plating solution and the copper layer at 10 to 24 A/dm2 of current density to form a plurality of nodules on the copper layer.

Description

FIELD OF THE INVENTION [0001] The present invention relates to a method of manufacturing a copper foil having a nickel layer, a copper foil produced by the method, an electrode for a secondary battery including the same, BATTERY}

The present invention relates to a method for producing a copper foil having a nodular layer, a copper foil produced by the method, and an electrode for a secondary battery including the copper foil and a secondary battery.

Generally, a copper foil is used as an anode current collector of a secondary battery.

The copper foil can be manufactured through a roll-to-roll (RTR) process using electrolytic plating. The copper foil produced by electrolytic plating is called an electrolytic copper foil. Such an electrolytic copper foil is used for the production of a negative electrode of a secondary battery, a flexible printed circuit board (FPCB) or the like through a roll-to-roll (RTR) process.

In recent years, metal-based active materials including tin and silicon have been used as negative electrode active materials in order to increase the capacity of secondary batteries. Such a metal-based active material has a large volume expansion rate during charging and discharging, so that it is easily removed from the copper foil, which is a current collector of the negative electrode, as compared with the conventional carbon-based active material. Such desorption causes a decrease in the capacity retention rate of the secondary battery and a shortening of the service life thereof, resulting in lower reliability of the secondary battery.

To solve this problem, it is necessary to increase the adhesion between the copper foil and the active material. There is a method of increasing the surface roughness of the copper foil by a method of increasing the adhesion between the copper foil and other materials. As a method for increasing the surface roughness of the copper foil, there is a method of forming a nodule on the surface of the copper foil. However, the particle size of the nodule formed by a conventional method is not only large but also uniform. When a copper foil containing a nodule having a large and uneven particle size is used as the current collector of the electrode for a secondary battery, the active material is not uniformly applied to the copper foil. As a result, local current concentration occurs during charging and discharging, and the efficiency of the secondary battery is lowered and the service life is shortened.

It is another object of the present invention to provide a method of manufacturing a copper foil capable of preventing the problems caused by limitations and disadvantages of the related art, a copper foil manufactured by such a manufacturing method, an electrode for a secondary battery including such a copper foil, and a secondary battery.

One embodiment of the present invention provides a method of manufacturing a copper foil including a nodule layer forming process using a plating solution capable of forming a fine nodule having a small size capable of enhancing adhesion between a copper foil and an active material without increasing surface roughness I want to.

Another embodiment of the present invention is to provide a copper foil which has excellent adhesion with an active material and does not cause imbalance in application of the active material. To this end, one embodiment of the present invention provides a copper foil comprising a nodule having a small and uniform particle size.

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

Other features and advantages of the invention will be set forth in the description which follows, or may be learned by those skilled in the art from the description.

To solve this problem, an embodiment of the present invention provides a method of manufacturing a semiconductor device, comprising: forming a copper layer; And forming a nodular layer on the copper layer, wherein the step of forming the nodular layer comprises the steps of: providing 7 to 10 g / L of copper ions, 90 to 120 g / L of sulfuric acid and 13 to 17 g / L of a metal ion; And a step of immersing the copper layer in the plating solution, applying a current between the plating electrode disposed in the plating solution and the copper layer at a current density of 10 to 25 A / dm < ² > And forming a plurality of nodules on the surface of the copper foil.

The step of forming the copper layer comprises the steps of: preparing an electrolytic solution containing 60 to 120 g / L of copper ions, 80 to 150 g / L of sulfuric acid, less than 50 ppm of chloride ions, and an organic additive; And electrodepositing copper on the rotating cathode drum by passing a positive electrode plate and a rotating cathode drum spaced apart from each other in the electrolyte solution at a current density of 30 to 80 A / dm ² .

The organic additive includes at least one of Hydroxyethyl Cellulose (HEC), organic sulfide, organic nitride, and thiourea-based compound.

The metal ion includes at least one of nickel (Ni) ion, iron (Fe) ion, tungsten (W) ion and molybdenum (Mo) ion.

The temperature of the plating solution is 20 to 30 占 폚.

The step of forming a plurality of nodules on the copper layer includes passing the copper layer through the plating liquid in a state where the copper layer is separated from the plating electrode.

The plating electrode is an anode, and the copper layer is a cathode.

The nodules have a maximum diameter of 0.5 mu m or less.

The method of manufacturing the copper foil further includes forming a rust preventive film on the nodular layer.

The rustproofing film includes at least one of chromium, benzotriazole (BTA) and silane compounds.

Another embodiment of the present invention relates to a copper layer having a matte surface and a shiny surface opposite thereto; And a nodule layer disposed on at least one of the matte surface and the shiny surface, the nodule layer having a plurality of nodules, and having a gloss (Gs 60 deg.) Of 6 or more and less than 30.

The nodules have a maximum diameter of 0.5 mu m or less.

The nodules may include copper (Cu); And at least one of nickel (Ni), iron (Fe), tungsten (W), and molybdenum (Mo).

Wherein the copper foil has a first surface in the matte surface direction and a second surface in the shiny surface direction, and at least one of the first surface and the second surface has a gloss degree (Gs 60 deg.) Of 6 or more and less than 30 .

The first surface and the second surface each have a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m.

The first surface and the second surface have a surface roughness (Rz JIS) difference of less than 0.5 mu m.

The copper foil has a thickness of 4 mu m to 35 mu m.

The copper foil further includes a rustproofing film on the nodular layer, and the rustproofing film includes at least one of chromium, benzotriazole (BTA) and silane compounds.

According to another embodiment of the present invention, there is provided a semiconductor device comprising: the copper foil; And an active material layer on the copper foil.

According to another embodiment of the present invention, there is provided a fuel cell including a cathode and an anode opposing each other; An electrolyte for providing an environment in which ions can move between the anode and the cathode; A separator for electrically insulating the anode and the cathode; And the negative electrode comprises the electrode for the secondary battery.

The nodule formed in the manufacturing method according to an embodiment of the present invention has a small and uniform particle size, and the copper foil having such a nodule can have excellent adhesion with the active material without increasing the surface roughness. In addition, when such a copper foil is used as an electrode for a secondary battery, adhesion between the active material and the copper foil is enhanced by the nodule, thereby improving the capacity retention rate of the secondary battery. Therefore, the secondary battery according to an embodiment of the present invention has a long life and high reliability.

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and, together with the description, serve to explain the principles of the invention.
1 is a schematic cross-sectional view of a copper foil according to an embodiment of the present invention.
2A is a scanning electron microscope (SEM) photograph of the surface of the copper layer before nodule formation, and FIG. 2B is a scanning electron microscope (SEM) photograph of the model layer.
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 a copper foil according to another embodiment of the present invention.
5 is a schematic cross-sectional view of a copper foil according to another embodiment of the present invention.
6 is a schematic cross-sectional view of an electrode for a secondary battery according to another embodiment of the present invention.
7 is a schematic cross-sectional view of a secondary battery according to another embodiment of the present invention.
8 is a schematic cross-sectional view of a secondary battery according to another embodiment of the present invention.
9 is a schematic view of a method of manufacturing the copper foil shown in Fig.

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 modifications and variations can be made in the present invention without departing from the spirit and scope of the invention. Accordingly, the invention includes all modifications and variations within the scope of the invention as defined in the appended claims and equivalents thereof.

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

Where the terms "comprises", "having", "comprising", and the like are used herein, other portions may be added unless the expression "only" is used. Where an element is referred to in the singular, it includes the plural unless specifically stated otherwise. Further, in interpreting the constituent elements, even if there is no separate description, it is interpreted to include an error range.

In the case of a description of the positional relationship, for example, if the positional relationship between two parts is described as 'on', 'on top', 'under', and 'next to' Or " direct " is used, one or more other portions may be located between the two portions.

In the case of a description of a temporal relationship, for example, if the temporal relationship is described by 'after', 'after', 'after', 'before', etc., May not be continuous unless they are not used.

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

It should be understood that the term "at least one" includes all possible combinations from one or more related items.

It is to be understood that each of the features of the various embodiments of the present invention may be combined or combined with each other, partially or wholly, technically various interlocking and driving, and that the embodiments may be practiced independently of each other, It is possible.

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

Referring to FIG. 1, a copper foil 100 according to an exemplary embodiment of the present invention includes a copper layer 110 and a metal layer 210 on a copper layer 110.

The copper layer 110 has a matte surface MS and a shiny surface SS opposite the matte surface MS.

According to one embodiment of the present invention, the copper layer 110 may be formed on the rotating cathode drum through electroplating (see FIG. 9). In this case, the shiny surface SS refers to the surface that has contacted the rotating cathode drum in the electroplating process, and the mat surface MS refers to the opposite surface to the shiny surface SS.

Though the shiny surface SS generally has a lower surface roughness (Rz JIS) than the mat surface MS, one embodiment of the present invention is not limited thereto. The surface roughness Rz JIS of the shiny surface SS may be equal to or higher than the surface roughness Rz JIS of the mat surface MS.

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

The node layer 210 disposed on the mat surface MS of the copper layer 110 is also referred to as a first node layer.

The nodule layer 210 has a plurality of nodules 201.

The shape of the nodule 201 is not particularly limited. The nodule 201 may have, for example, a protrusion or a particle shape protruding from the copper layer 110. More specifically, nodule 201 may have a spherical, hemispherical, oval, dome, polyhedral, needle or other irregular shape. According to an embodiment of the present invention, the nodule 201 may have a spherical shape.

According to an embodiment of the present invention, the Nodule layer 210 may include 30 to 150 nodules 201 per 1 탆 ² . The number of nodules 201 per 1 μm ² can be counted using a scanning electron microscope (SEM) photograph.

When the number of the nodules 201 per 1 μm ² is less than 30, for example, when the copper foil 100 is used as a current collector of the electrode for the secondary battery, the peeling strength between the copper foil 100 and the active material is lowered, The capacity retention rate of the battery can be lowered.

On the other hand, when the number of the nodules 201 per 1 탆 ² exceeds 150, the number of the nodules 201 is excessively large and the nodule 201 is formed unevenly, and the surface roughness Rz JIS of the copper foil 100 becomes excessively large . Accordingly, when the copper foil 100 is used as the current collector of the electrode for the secondary battery, the active material is uniformly applied to the copper foil 100, so that local concentration of the current occurs during charging and discharging of the secondary battery, Can be shortened.

When the nodule 201 is not perfectly spherical, one nodule 201 may have two or more different diameters. Accordingly, with respect to the size of the nodule, the embodiments of the present invention will be described using the maximum diameter d of the nodule 201 for convenience. The maximum diameter of the nodule 201 means the largest diameter among the diameters measured in the nodule 201. [

The maximum diameter d of the nodule 201 is defined as the largest diameter among the diameters of the nodule 201 measured along a direction parallel to the interface between the nodule layer 210 and the copper layer 110 . Referring to FIG. 1, the interface between the nucleus layer 210 and the copper layer 110 is a matte surface MS, and the diameter of the nodule 201 can be measured along a direction parallel to the matte surface MS.

According to one embodiment of the present invention, the nodule 201 has a maximum diameter of 0.5 mu m or less. More specifically, the nodule 201 may have a maximum diameter of 0.01 탆 to 0.5 탆. However, the embodiment of the present invention is not limited thereto, and the nodule may have a maximum diameter of 0.05 탆 to 0.5 탆.

When the maximum diameter d of the nodule 201 exceeds 0.5 탆, the surface roughness Rz JIS of the copper foil 100 may excessively increase. In this case, when the copper foil 100 is used as the current collector of the electrode for the secondary battery, the active material is uniformly applied to the copper foil 100, so that local concentration of the current may occur during charging and discharging of the secondary battery. The local concentration of the current can shorten the lifetime of the electrode, which may result in shortening the lifetime of the secondary battery.

On the other hand, when the maximum diameter of the nodule 201 is less than 0.01 탆, the increase in the surface roughness Rz JIS of the copper foil 100 is insignificant and when the copper foil 100 is used as a current collector of the electrode for a secondary battery, ) And the active material may not be expected to increase.

According to one embodiment of the present invention, the copper foil 100 has a glossiness (Gs60 degrees) of 6 or more and less than 30.

The glossiness is measured by irradiating the copper foil 100 with light having an incident angle of 60 degrees using a gloss meter (VG7000, Nippon-denshoku) according to JIS Z 8741 standard. Referring to FIG. 1, when measuring the cohesive force (Gs60) of the copper foil 100, the gloss of the nodular layer 210 corresponding to the surface of the copper foil 100 is measured. Therefore, the gloss of the nodular layer 210 is also referred to as the gloss of the copper foil 100.

The glossiness is related to the number of the nodules 201 and the current density applied for forming the nodules 201. Generally, as the current density applied in the process of forming the nucleolar layer 210 increases, the number of nodules increases. As the number of the nodules 201 increases, the gloss of the copper foil 100 decreases.

On the other hand, as the current density applied in the process of forming the nucleolar layer 210 is decreased, the number of nodules decreases, and as the number of the nodules 201 decreases, the gloss of the copper foil 200 increases.

When the degree of gloss Gs60 of the copper foil 100 is 30 or more, the number of the nodules 201 formed in the nickel layer 210 is small and when the copper foil 100 is used as a current collector of the electrode for a secondary battery, ) Deteriorates in the peel strength of the active material, and the capacity retention rate of the secondary battery may be lowered. On the other hand, when the gloss level Gs60 of the node layer 210 is less than 6, the number of the nodules 201 formed in the nodule layer 210 is excessively large and the copper foil 100 is used as the current collector of the electrode for the secondary battery The active material is applied to the copper foil 100 in a non-uniform manner, so that local concentration of current occurs during charging and discharging of the secondary battery. As a result, the service life of the electrode and the secondary battery can be shortened.

2A is a photograph of a scanning electron microscope (SEM) (model name S4800) for the surface of the copper layer 110 and FIG. 2B is a photograph of a scanning electron microscope (SEM) (Model S4800) for the model layer 210. FIG. Referring to FIG. 2A, the copper layer 110 does not have a perfect flat surface but has a fine surface nonuniformity. Also, referring to FIG. 2B, the nucleus layer 210 includes a plurality of nodules 201 in the form of grains. The copper foil of FIG. 2B having a modulus layer 201 has low gloss.

According to one embodiment of the present invention, the nodule 201 may comprise copper (Cu) and at least one metal selected from nickel (Ni), iron (Fe), tungsten (W) and molybdenum .

More specifically, the nodule 201 may be made of a copper alloy. For example, the nodule 201 may include at least one of nickel (Ni), iron (Fe), tungsten (W), and molybdenum (Mo) and copper (Cu). When the copper foil 100 is used as the current collector of the electrode for the secondary battery, the peeling strength of the copper foil 100 and the active material can be easily adjusted, because the small size nodule 201 can be easily produced by the alloy of copper and another metal. Can be increased.

The nodule 201 may be formed integrally with the copper layer 110 in succession to the copper layer 110.

According to one embodiment of the present invention, the copper foil 100 has a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m.

When the surface roughness (Rz JIS) of the copper foil 100 is less than 0.7 mu m, when the copper foil 100 is used as a current collector for an electrode for a secondary battery, the adhesion strength between the copper foil 100 and the active material is low, Accordingly, when the secondary battery is charged or discharged, peeling of the active material may occur.

On the other hand, when the surface roughness (Rz JIS) of the copper foil 100 exceeds 3.0 mu m, the active material is not uniformly coated on the copper foil when the copper foil 100 is used as the current collector of the electrode for the secondary battery, The current is locally concentrated at the time of discharging, and the charge / discharge cycle characteristic is lowered, and the capacity retention rate of the secondary battery may be lowered.

The surface roughness (Rz JIS) according to an embodiment of the present invention is also referred to as a ten-point average roughness and can be measured by a surface roughness meter (M300, Mahr) according to JIS B 0601-2001.

According to one embodiment of the present invention, the copper foil 100 has a first surface S1 in the direction of the mat surface MS and a second surface S2 in the direction of the shiny surface SS, . The first surface S1 and the second surface S2 of the copper foil 100 are the surfaces of the copper foil, respectively. Referring to FIG. 1, the first surface S1 of the copper foil 100 is the surface of the nucleolar layer 210, and the second surface S2 is the shiny surface SS of the copper layer 110. Referring to FIG.

Since the first surface S1 of the copper foil 100 corresponds to the surface of the nodular layer 210 in Figure 1, the surface roughness of the nodular layer 210 is set such that the surface roughness of the surface of the first surface S1 of the copper foil 100 It can be illuminance. In addition, the surface roughness of the shiny surface SS can be the surface roughness of the second surface S2 of the copper foil 100. [

According to an embodiment of the present invention, the first surface S1 and the second surface S2 of the copper foil 100 may have a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m, respectively.

The first surface S1 and the second surface S2 of the copper foil 100 have a surface roughness (Rz JIS) difference of less than 0.5 mu m. When the difference in surface roughness Rz JIS between the first surface S1 and the second surface S2 of the copper foil 100 is 0.5 占 퐉 or more when the copper foil 100 is used as a current collector of the electrode for a secondary battery, The active material may not be evenly coated on the first surface S1 and the second surface S2 due to the difference in surface roughness Rz JIS between the surface S1 and the second surface S2. Accordingly, when the secondary battery is charged / discharged, the charging / discharging characteristics of the both surfaces S1 and S2 are different from each other, so that the lifetime of the secondary battery may be rapidly lowered.

According to an embodiment of the present invention, the copper foil 100 has a thickness of 4 mu m to 35 mu m.

When the copper foil 100 is used as a current collector for a secondary battery electrode, the thinner the copper foil 100 is, the more current collectors can be accommodated in the same space, which is advantageous for the high capacity of the secondary battery. However, when the thickness of the copper foil 100 is less than 4 mu m, workability is lowered in the process of manufacturing the electrode or secondary battery using the copper foil 100. [ On the other hand, when the thickness of the copper foil 100 is more than 35 μm, the thickness of the electrode for the secondary battery using the copper foil 100 becomes large, and it may be difficult to realize a high capacity of the secondary battery due to such a large thickness.

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 redundancy, a description of the components already described is omitted.

3, the copper foil 200 according to another embodiment of the present invention includes two copper layers 110 and two metal layers 210 and 210 disposed on both sides MS and SS of the copper layer 110, 220). Compared to the copper foil 100 shown in FIG. 1, the copper foil 200 shown in FIG. 3 further includes a nickel layer 220 disposed on the shiny surface SS of the copper layer 110.

The two modulus layers 210 and 220 may be made of the same material by the same process or may be made of different materials by different processes.

For convenience of description, the nodule layer 210 disposed on the mat surface MS of the copper layer 110 among the two nodule layers 210 and 220 is referred to as a first nodule layer and disposed on the shiny surface SS And the nodular layer 220 is referred to as a second node layer.

The second nodule layer 220 has a plurality of nodules 202 like the first nodule layer 210. The second nodule layer 220 has 30 to 150 nodules 202 per 1 탆 ² and the nodule 202 of the second nodule layer 220 has the second nodule layer 220 and the copper layer 110 And has a maximum diameter d2 of 0.5 mu m or less, measured along a direction parallel to the interface, that is, the shiny surface SS.

The nodule 202 of the second module layer 220 may be made of a copper alloy. More specifically, the nodule 202 of the second nucleus layer 220 may include at least one of nickel (Ni), iron (Fe), tungsten (W), and molybdenum (Mo) and copper (Cu).

3, the first surface S1 of the copper foil 200 is the surface of the first module layer 210 and the second surface S2 of the copper foil 200 is the surface of the second module layer 220 to be.

According to another embodiment of the present invention, the copper foil 200 has a glossiness (Gs60 degrees) of 6 or more and less than 30. Specifically, at least one of the first surface S1 and the second surface S2 of the copper foil 200 has a glossiness (Gs 60 deg.) Of 6 or more and less than 30. Both of the first surface S1 and the second surface S2 may have a glossiness (Gs 60 deg) of 6 or more and less than 30.

The copper foil 200 has a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m. Specifically, the first surface S1 and the second surface S2 of the copper foil 400 may have a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m, respectively.

In addition, the first surface S1 and the second surface S2 of the copper foil 200 have a surface roughness (Rz JIS) difference of less than 0.5 mu m.

The copper foil 300 shown in Fig. 3 may have a thickness of 4 to 35 mu m.

4 is a schematic cross-sectional view of a copper foil 300 according to another embodiment of the present invention.

4, the copper foil 300 according to another embodiment of the present invention includes a copper layer 110, a nucleus layer 210 disposed on the copper layer, and a rustproof film 210 disposed on the nucleus layer 210. [ (231). The anticorrosive film 231 is disposed on a plurality of nodules 201.

Compared with the copper foil 100 shown in Fig. 1, the copper foil 300 shown in Fig. 4 further includes a rust preventive film 231 disposed on the nodular layer 210

The rust preventive film 231 protects the copper layer 110 and the nodular layer 210 to prevent the copper layer 110 and the nodular layer 210 from being oxidized or deteriorated. Therefore, the anticorrosive film 231 is also referred to as a protective layer.

The anticorrosive film 231 may include at least one of chromium (Cr), benzotriazole (BTA), and silane compounds. For example, the anticorrosive film 231 can be made of a rustproofing liquid containing chromium (Cr) ions or a rustproofing liquid containing a chromate compound. The anticorrosive film 231 may be made of benzotriazole (BTA) or a silane coupling agent.

The nodule 201 constituting the nodular layer 210 has a maximum diameter of 0.5 μm or less. The nodule 201 may include at least one selected from the group consisting of copper (Cu) and nickel (Ni), iron (Fe), tungsten (W), and molybdenum (Mo)

According to another embodiment of the present invention, the copper foil 300 has a gloss degree (Gs 60 deg.) Of 6 or more and less than 30. Specifically, the copper foil 300 has a first surface S1 in the direction of the mat surface MS and a second surface S2 in the direction of the shiny surface SS, and the first surface S1 and the second surface S2 ) Has a glossiness (Gs 60 deg.) Of 6 or more and less than 30.

The copper foil 300 has a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m. Specifically, the first surface S1 and the second surface S2 of the copper foil 300 may have a surface roughness (Rz JIS) of 0.7 m or more and 3.0 m or less, respectively. The difference in surface roughness Rz JIS between the first surface S1 and the second surface S2 is less than 0.5 mu m.

Further, the copper foil 300 has a thickness of 4 mu m to 35 mu m.

5 is a schematic cross-sectional view of a copper foil 400 according to another embodiment of the present invention.

5, a copper foil 400 according to another embodiment of the present invention includes a copper layer 110, a metal layer 210 and 220 disposed on both sides MS and SS of the copper layer 110, And rustproofing films 231 and 241 disposed on the nodular layers 210 and 220, respectively.

Compared to the copper foil 100 shown in Fig. 3, the copper foil 400 shown in Fig. 5 further includes two rustproofing films 231 and 241 disposed on two node layers 210 and 220, respectively

The two modulus layers 210 and 220 may be made of the same material by the same process or may be made of different materials by different processes. Further, the two anticorrosive films 231 and 241 may be made of the same material by the same process or may be made of different materials by another process.

The anticorrosive films 231 and 241 may include at least one of chromium (Cr), benzotriazole (BTA), and silane compounds.

In the copper foil 400 shown in Fig. 5, nodules 201 and 202 constituting the nodule layers 210 and 220 have a maximum diameter of 0.5 mu m or less, respectively. The nodules 201 and 202 may include at least one selected from the group consisting of nickel (Ni), iron (Fe), tungsten (W), and molybdenum (Mo) together with copper (Cu).

According to another embodiment of the present invention, the copper foil 400 has a glossiness (Gs60 degrees) of 6 or more and less than 30. Specifically, at least one of the first surface S1 and the second surface S2 of the copper foil 400 has a glossiness (Gs 60 deg.) Of 6 or more and less than 30. Both of the first surface S1 and the second surface S2 may have a glossiness (Gs 60 deg) of 6 or more and less than 30.

The copper foil 400 has a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m. Specifically, the first surface S1 and the second surface S2 of the copper foil 400 may have a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m, respectively.

The difference in surface roughness Rz JIS between the first surface S1 and the second surface S2 of the copper foil 400 is less than 0.5 mu m.

The copper foil 400 has a thickness of 4 mu m to 35 mu m.

6 is a schematic cross-sectional view of an electrode 500 for a secondary battery according to another embodiment of the present invention.

The secondary battery electrode 500 shown in Fig. 6 can be applied to the secondary battery 700 shown in Fig. 8, for example.

An electrode 500 for a secondary battery according to another embodiment of the present invention includes a copper foil 300 and an active material layer 310 on the copper foil 300.

6, an electrode 500 for a secondary battery according to another embodiment of the present invention includes a copper foil 300 having a first surface S1 and a second surface S2, And an active material layer 310 disposed on at least one of the surface S1 and the second surface S2. In the secondary battery electrode 500, the copper foil 300 serves as a current collector.

In FIG. 6, the current collector is exemplified by the copper foil 300 shown in FIG. 4, but the present invention is not limited thereto. The copper foils 100, 200, and 400 shown in FIGS. 1, 3, and 5 may also be used as current collectors for the secondary battery electrode 500.

6, a structure in which the active material layer 310 is disposed on the first surface S1 of the copper foil 300 is shown in FIG. 6. However, the present invention is not limited thereto. The active material layer may be disposed on both the first surface S1 and the second surface S2 of the copper foil 300 and the active material layer may be disposed only on the second surface S2 of the copper foil 300 have.

The active material layer 310 shown in FIG. 6 includes an electrode active material, and particularly includes a negative active material. That is, the secondary battery electrode 500 shown in FIG. 6 can 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 complex of a metal and carbon. As the metal, at least one of Si, Ge, Sn, Li, Zn, Mg, Cd, Ce, Ni and Fe may be used. In order to increase the charge / discharge capacity of the secondary battery, the active material layer 310 may include at least one of tin (Sn) and silicon (Si).

7 is a schematic cross-sectional view of an electrode 600 for a secondary battery according to another embodiment of the present invention.

An electrode 600 for a secondary battery according to another embodiment of the present invention includes a copper foil 400 and active material layers 310 and 320 on the copper foil 400. [ The copper foil 400 includes a copper layer 110, a nodular layer 210 on both sides of the copper layer 110 and rustproofing films 231 and 241 on the nodular layers 210 and 220.

7 includes two active material layers 310 and 320 respectively disposed on the first surface S1 and the second surface S2 of the copper foil 400. In this case, . The active material layer 310 disposed on the first surface S1 of the copper foil 400 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 400, Is also 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 method, or may be made of different materials or by other methods.

The copper foil 400 is used as a current collector of the electrode 600 for the secondary battery.

7 illustrates a case where the current collector is the copper foil 300 shown in FIG. 5, but the present invention is not limited thereto. The copper foils 300 shown in FIGS. 1, 3 and 4 100, 200, and 300 may also be used as current collectors of the secondary battery electrode 600.

The secondary battery electrode 600 shown in Fig. 7 can be applied to the secondary battery 700 shown in Fig. 8, for example.

8 is a schematic cross-sectional view of a secondary battery 700 according to another embodiment of the present invention. The secondary battery 700 shown in Fig. 8 is, for example, a lithium secondary battery.

8, the secondary battery 700 includes an anode 340 and a cathode 370 facing each other and an environment in which ions can move between the anode 370 and the cathode 340 And a separator 360 that electrically isolates the anode 370 from the cathode 340. The separator 360 separates the anode 350 and the cathode 350 from each other. 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 from each other in order to prevent the charge generated from one electrode from being wasted by moving to the other electrode through the interior of the secondary battery 700. Referring to FIG. 8, a separation membrane 360 is disposed in the electrolyte 350.

The anode 370 includes a cathode current collector 371 and an active material layer 372. The active material layer 372 of the anode 370 includes a cathode active material. An aluminum foil may be used as the positive electrode current collector 371 to be combined with the active material layer 372 of the positive electrode 370. [

The cathode 340 includes an anode current collector 341 and an active material layer 342. The active material layer 342 of the cathode 340 includes a negative electrode active material.

The copper foils 100, 200, 300, and 400 disclosed in Figs. 1, 3, 4, and 5 may be used as the anode current collector 341 to be combined with the active material layer 342 of the cathode 340. The secondary battery electrode 500 shown in FIG. 6 or the secondary battery electrode 600 shown in FIG. 7 can be used as the cathode 340 of the secondary battery 700 shown in FIG.

Hereinafter, a method of manufacturing the copper foil 400 according to another embodiment of the present invention will be described in detail with reference to FIG.

9 is a schematic view of a method of manufacturing the copper foil 400 shown in Fig.

The method of manufacturing the copper foil 400 according to another embodiment of the present invention includes forming the copper layer 110 and forming the node layers 210 and 220 on the copper layer 110 .

The step of forming the copper layer 110 comprises the steps of preparing an electrolytic solution 11 comprising 60 to 120 g / L copper ions, 80 to 150 g / L sulfuric acid, less than 50 ppm of chloride ions and organic additives, and The positive electrode plate 13 and the rotating negative electrode drum 12 which are arranged so as to be spaced apart from each other in the electrolyte 11 are energized at a current density of 30 to 80 A / dm ² (ASD) to deposit copper on the rotating negative electrode drum 12 .

Specifically, the positive electrode plate 13 and the rotating negative electrode drum 12, which are spaced apart from each other in the electrolytic solution 11 contained in the electrolytic bath 10, are energized at a current density of 30 to 80 ASD (A / dm ² ) The copper layer 110 is formed by electrodepositing copper on the copper layer 12. The distance between the positive electrode plate 13 and the rotating cathode drum 12 may be 8 to 13 mm.

The electrolytic solution 11 contains 60 to 120 g / L of copper ions, 80 to 150 g / L of sulfuric acid, less than 50 ppm of chloride ions, and organic additives. The organic additive may include at least one selected from the group consisting of hydroxyethyl cellulose (HEC), organic sulfides, organic nitrides, and thiourea-based compounds.

The electrolytic solution 11 may be maintained at 40 to 60 DEG C and the electrolytic solution 11 supplied to the electrolytic bath 10 may have a flow rate of 30 to 50 m < ³ > / hour. The flow rate variation of the electrolytic solution 11 supplied to the electrolytic bath 10 can be adjusted within 2%.

The surface roughness of the mat surface MS of the copper layer 110 can be controlled by adjusting the current density, the organic additive, and the like.

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 cathode drum 12. [ The surface of the rotary cathode drum 12 can be polished with an abrasive brush having a grain size of, for example, # 800 to # 1500, for adjusting the surface roughness of the shiny surface SS.

After formation of the copper layer 110, the copper layer 110 may be cleaned, if necessary. The cleaning process may be omitted.

Next, the nodular layers 210 and 220 are formed on the copper layer 110.

According to another embodiment of the present invention, the step of forming the Nodular layers 210 and 220 includes a plating solution 31 containing plating ions other than copper ions and copper ions, a plating electrode 33, Is performed in the plating tank (30) including the drum (32).

Specifically, the step of forming the Nodular layers 210 and 220 includes a plating solution 31 containing 7 to 10 g / L of copper ion, 90 to 120 g / L of sulfuric acid and 13 to 17 g / And a step of immersing the copper layer 110 in the plating solution 31 to remove the copper layer 110 between the plating electrode 33 and the copper layer 110 disposed in the plating solution 31 and spaced apart from the copper layer 110 And forming a plurality of nodules 201, 202 on the copper layer 110 by applying a current at a current density of 25 A / dm ² (ASD).

More specifically, the step of forming a plurality of nodules 201 and 202 on the copper layer 110 may include forming the copper layer 110 on the plating liquid 31 (31) while separating the copper layer 110 from the plating electrode 33 ). ≪ / RTI > A plurality of nodules 201 and 202 are formed on the copper layer 110, thereby forming the nodule layers 210 and 220.

The metal ions contained in the plating liquid 31 include at least one of nickel (Ni) ion, iron (Fe) ion, tungsten (W) ion and molybdenum (Mo) ion.

Nodules 201 and 202 made of a copper alloy having a spherical shape and a small particle size are formed by applying a current density of 10 to 25 ASD to a plating liquid 31 produced by using copper (Cu) ions and ions of other metals together Lt; / RTI > For example, the nodules 201 and 202 may be made of an alloy of copper (Cu) and nickel (Ni).

When a current with a current density lower than 10 ASD is applied in the process of forming the nodules 201 and 202, generation of the nodules 201 and 202 is scarcely generated. Accordingly, the effect of improving adhesion between the copper foil 400 and other materials, for example, the electrode active material, does not occur.

On the other hand, when a current having a current density higher than 25 ASD is applied, the nodule grows excessively, so that the roughness of the copper foil 400 rises and the sizes of the nodules 201 and 202 become uneven. If the size of the nodules 201 and 202 is uneven, uneven appearance occurs in the width direction of the copper foil 400 apparently, and the capacity retention rate of the secondary battery manufactured using the copper foil 400 may be lowered.

According to an embodiment of the present invention, a spherical copper alloy nodule smaller in size than a conventional nodule is formed on the surface of the copper layer 110 so that the surface roughness of the copper foil 400 is not increased, The adhesion between the active material 400 and the active material can be increased.

In the step of forming the nucleus layers 210 and 220, the temperature of the plating solution 31 is maintained at 20 to 30 ° C.

The plating electrode 33 disposed in the plating bath 30 is an anode and the copper layer 110 is a cathode. The plating electrode 33 may be connected to the anode of the external power source, and the copper layer 110 may be connected to the cathode of the external power source. For example, the step of forming the Nodular layers 210 and 220 may include a step of forming the copper layer 110 and a continuous process, so that the copper layer 110 is maintained in contact with the rotating cathode drum 12 So that the copper layer 110 can function as a cathode.

The nodules 201 and 202 thus formed have a maximum diameter of 0.5 mu m or less.

According to an embodiment of the present invention, as the current density applied in the process of forming the Nodule layers 210 and 220 increases, the number of nodules 201 and 202 having a maximum diameter d of 0.5 μm or less increases, 400) is reduced (Gs 60 deg.). On the other hand, as the current density applied in the process of forming the nodular layers 210 and 220 decreases, the number of the nodules 201 having the maximum diameter d of 0.5 m or less decreases and the gloss of the copper foil 400 increases.

Then, the copper layer 110 and the nodular layers 210 and 220 may be selectively cleaned. Such cleaning may be omitted.

Next, rust preventive films 231 and 241 are formed on the Nodular layers 210 and 220.

The step of forming the anticorrosive films 231 and 241 on the nodular layers 210 and 220 may be performed in the anticorrosive tank 50 including the anticorrosive solution 51.

For example, the anticorrosive films 231 and 241 can be made of the anticorrosive solution 51 containing chromium (Cr) ions or the anticorrosive solution 51 containing chromic acid compounds. At this time, the rust preventive liquid 51 may contain 0.5 to 5 g / L of chromium ions.

The rust preventive films 231 and 241 may be formed by a silane coupling agent. Silanes having an olefin group, an epoxy group, an amino group, or a mercapto group may be used as the silane coupling agent.

Further, the anticorrosive films 231 and 241 may be made of benzotriazole (BTA).

The thus formed rust preventive films 231 and 241 may include at least one of chromium (Cr), benzotriazole (BTA) and silane compounds.

The copper foil 400 is completed by forming the antirust films 231 and 241.

The completed copper foil 400 can be cleaned. Cleaning may be omitted.

Next, after the drying process is performed, the copper foil 400 is wound on the winder WR.

Hereinafter, the present invention will be described in detail with reference to production examples and comparative examples. However, the following production examples are provided only to aid understanding of the present invention, and do not limit the scope of the present invention.

≪ Preparation Example 1-4 and Comparative Example 1-5 >

A copper foil was fabricated using a negative electrode plate including an electrolytic bath 10, a rotating negative electrode drum 12 disposed in the electrolytic bath 10, and a positive electrode plate 13 spaced apart from the rotating negative electrode drum 12. The electrolytic solution (11) was a copper sulfate solution. The copper ion concentration of the copper sulfate solution was maintained at 90 g / L, the sulfuric acid concentration was 120 g / L and the chlorine concentration was less than 50 ppm. Hydroxyethyl cellulose (HEC), which is an organic additive, and thiourea system were added to the electrolytic solution 11 in amounts of 5 ppm each.

Copper was electrodeposited on the rotating cathode drum 12 in a state where the temperature of the electrolytic bath was maintained at 50 캜 and the current density of 55 ASD to prepare a copper foil 110 having a circular shape.

Next, a nucleus layer 210 having a plurality of nodules 201 is formed on the surface of the copper layer 110 by using a plating bath 30 including a nucleus layer forming plating solution 31. However, in the case of Comparative Example 1, the process of forming a nodule layer is omitted.

The nodule layer forming plating liquid 31 contains 9 g / L of copper (Cu) ions, 100 g / L of sulfuric acid and nickel (Ni) ions of the concentrations shown in Table 1 below. A plurality of nodules 201 were formed on the surface of the copper layer 110 by applying a current of the current density shown in Table 1 to the nickel layer forming plating solution 31 at a room temperature of 25 占 폚.

At this time, only the plating electrode 33 spaced apart from and opposite to the mat surface MS of the copper layer 110 is used, so that only the nodule 201 and the moduli layer MS are formed on the mat surface MS of the copper layer 110, (210).

After the formation of the nodular layer 210, a rust preventive film 231 was formed on the nodular layer 210 through a chromate treatment using a rust preventive solution having a chromium concentration of 1 g / L.

(I) surface roughness (R _z JIS) and (ii) gloss were measured for the copper foils of Production Examples 1-4 and Comparative Example 1-5 thus produced, and (iii) .

(i) Surface roughness (R _z  JIS)

The surface roughness (Rz JIS) of the copper foil was measured using a surface roughness meter (M300, Mahr) according to JIS B 0601-2001.

(ii) glossiness (Gs60 degrees)

(Gs60 占) of the copper foil was measured using a gloss meter (VG7000, Nippon-denshoku) according to JIS Z 8741 standard. At this time, the copper foil was irradiated with light having an incident angle of 60 ° to measure the light intensity (Gs 60 °).

(iii) appearance stain

The surface of the copper foil was visually observed to evaluate whether appearance unevenness occurred. Quot; no "if appearance unevenness was not observed, and" uncolored "when appearance unevenness was observed.

(iv) Peel strength of active material

Using the copper foils of Production Example 1-4 and Comparative Example 1-5, an electrode for a secondary battery was prepared and the peel strength of the active material was measured.

1) Active material coating

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 carbonaceous material for negative electrode active material, and distilled water was used as a solvent to prepare a slurry for an anode active material. Subsequently, a slurry for negative electrode active material was coated on the copper foil of Production Example 1-4 and Comparative Example 1-5 having a width of 10 cm with a doctor blade to a thickness of 40 mu m, dried at 120 DEG C for 10 minutes, / Cm < 2 > to form an anode active material layer, thereby manufacturing an electrode (cathode) for a secondary battery.

2) Peel strength measurement

The peel strength of the copper foil and the anode active material layer was measured using a universal testing machine (UTM) according to the IPC-TM-650 standard. The width of the measurement sample was 12.7 mm and the measurement speed was 50 mm / min. The supporting plate and the anode active material layer were attached with double-sided tape and the peeling strength was measured while peeling the copper foil with 90..

(v) capacity retention rate

A test secondary battery was manufactured and the capacity retention rate was measured.

1) Negative electrode 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 carbonaceous material for negative electrode active material, and distilled water was used as a solvent to prepare a slurry for an anode active material. Using a doctor blade, a slurry for negative electrode active material was coated on the copper foil of Production Example 1-4 and Comparative Example 1-5 having a width of 10 cm to a thickness of 40 탆, dried at 120 캜 and subjected to a pressure of 1 ton / To prepare a negative electrode for a secondary battery.

2) Manufacture of electrolytic solution

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

 3) Anode manufacturing

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 were mixed at a ratio of 90:10 (weight ratio) to prepare a cathode active material. The cathode active material, carbon black, and PVDF [poly (vinylidenefluoride)] as a binder were mixed at a ratio of 85: 10: 5 (weight ratio) and mixed with NMP as an organic solvent to prepare a slurry. The slurry thus prepared was coated on both sides of an aluminum foil having a thickness of 20 탆 and dried to prepare a positive electrode.

4) Preparation of test 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 non-aqueous electrolyte and a separation membrane were disposed therebetween to produce a coin-shaped lithium secondary battery. The separator used was polypropylene (Celgard 2325, thickness 25 μm, average poresize 28 nm, porosity 40%).

5) Capacity retention rate evaluation

Using the thus prepared lithium secondary battery, the capacity per g of the positive electrode was measured by driving the cell at a charge voltage of 4.3 V and a discharge voltage of 3.4 V. In order to evaluate the high-temperature lifetime, 50 charge / discharge experiments were performed at a high temperature of 50 ° C at a current rate (C-rate) of 0.2 C to calculate the capacity retention rate. When the capacity retention rate is less than 90%, it is determined that the copper foil is unsuitable as a negative electrode current collector for a lithium ion battery

The capacity retention rate can be calculated by the following equation (1).

[Formula 1]

Capacity retention rate (%) = (50 cycles before / after charge / 1 charge before / after charge) x 100

The above test results are shown in Table 1 below.

In plating solution
Ni concentration
(g / L) Nodule formation
Current density
(ASD) Surface roughness
Rz JIS
(탆) Glossiness
(Gs60 degrees) Appearance stain
Occurrence
(Visual confirmation) Active material
Peel strength
(N / mm ² ) Volume
Retention rate
(%) Production Example 1 17 10 1.02 25 radish 21.5 92 Production Example 2 13 15 1.05 19 radish 23.2 92 Production Example 3 15 20 1.09 11 radish 22.1 90 Production Example 4 14 25 1.11 8 radish 24.4 91 Comparative Example 1 0 - 0.95 130 radish 11.6 83 Comparative Example 2 18 5 1.01 79 radish 11.4 85 Comparative Example 3 15 8 1.02 46 radish 12.0 85 Comparative Example 4 10 28 1.35 5 U 23.8 83 Comparative Example 5 12 30 1.41 4 U 25.1 86

Referring to Table 1, when the applied current density is less than 10 ASD (A / cm ² ) in the process of forming the nodule layer, nodules are hardly generated and it is difficult to expect adhesion enhancement between the copper foil and the active material layer. In addition, when the current density applied in the process of forming the nodule layer is larger than 25 ASD, the nodule grows excessively and the roughness of the copper foil rises. As a result, the size of the nodules is uneven, and the appearance of unevenness along the width direction of the copper foil occurs. Therefore, the current density in the nomodelayer formation process is suitably in the range of 10 to 25 A / dm ² (ASD)

Specifically, in the case of Comparative Example 1 in which no nodular layer is formed, the capacity retention rate and the peel strength are lowered.

In Comparative Examples 2 and 3 in which the current density was less than 10 ASD, the capacity retention ratio and the peel strength were lowered.

In Comparative Examples 4 and 5 in which the current density exceeded 20 ASD, the peel strength between the copper foil and the active material layer was excellent but the capacity retention rate was lowered. In Comparative Examples 4 and 5, the gloss (Gs 60 deg) of the copper foil was lowered and the surface roughness (Rz JIS) was increased as compared with Production Example 1-4. In the case of Comparative Examples 4 and 5, it was judged that the active material was uniformly applied to the copper foil, thereby decreasing the capacity retention rate. In addition, appearance unevenness occurred due to unevenness of nodules.

The gloss (Gs 60 °) is related to the change in current density. As the applied current density increases during the nomodelayer formation process, the surface of the copper foil becomes darker in color and the gloss decreases. Referring to Production Example 1-4, the glossiness is preferably less than 30. Further, referring to Comparative Example 4-5, the glossiness is preferably 6 or more.

The roughness (Rz JIS) is adjusted to 0.7 mu m or more and 3.0 mu m or less.

Comparing the production examples 1-4 and the comparison examples 1-3, it can be confirmed that the copper foil according to the present invention has excellent adhesion with the active material without a large increase in surface roughness.

Referring to the production examples of the present invention, a spherical small nodule can be formed by applying an appropriate current to a plating solution for forming a nodule layer containing ions of copper and another metal. Since a small-sized spherical alloy nodule is formed on the copper layer, adhesion between the copper foil and the active material can be increased without increasing the surface roughness of the copper foil. Therefore, the electrode for a secondary battery using such a copper foil can have excellent peel strength and capacity retention rate.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. To those skilled in the art. Therefore, the scope of the present invention is defined by the appended claims, and all changes or modifications derived from the meaning, scope and equivalents of the claims are to be construed as being included in the scope of the present invention.

100, 200, 300, 400: copper
110: copper layer
201, 202: Nodule
210, 220, 230, 240: Nodular layer
310, 320: active material layer
500, 600: electrode for secondary battery
MS: Matte cotton
SS: Shiny Face

Claims (20)

Forming a copper layer; And
And forming a nodular layer on the copper layer,
The step of forming the nodule layer comprises:
Preparing a plating solution containing 7 to 10 g / L of copper ion, 90 to 120 g / L of sulfuric acid, and 13 to 17 g / L of metal ion; And
The copper layer is immersed in the plating solution, and a current is applied between the copper layer and the plating electrode disposed in the plating solution and spaced apart from the copper layer at a current density of 10 to 25 A / dm < ^{2 &} Forming a nodule of the first layer;
Wherein the copper foil is a copper foil. The method according to claim 1,
Wherein forming the copper layer comprises:
Preparing an electrolytic solution containing 60 to 120 g / L of copper ions, 80 to 150 g / L of sulfuric acid, less than 50 ppm of chlorine ions, and an organic additive; And
Electrodepositing copper on the rotating cathode drum by energizing the positive electrode plate and the rotating cathode drum spaced apart from each other in the electrolyte solution at a current density of 30 to 80 A / dm ² ;
Wherein the copper foil is a copper foil. 3. The method of claim 2,
Wherein the organic additive comprises at least one of hydroxyethyl cellulose (HEC), organic sulfide, organic nitride, and thiourea based compound. The method according to claim 1,
Wherein the metal ion comprises at least one of nickel (Ni) ion, iron (Fe) ion, tungsten (W) ion and molybdenum (Mo) ion. The method according to claim 1,
Wherein the temperature of the plating solution is 20 to 30 占 폚. The method according to claim 1,
Wherein the step of forming a plurality of nodules on the copper layer includes passing the copper layer through the plating liquid while leaving the copper layer away from the plating electrode. The method according to claim 1,
Wherein the plating electrode is an anode and the copper layer is a cathode. The method according to claim 1,
Wherein the nodule has a maximum diameter of 0.5 mu m or less. The method according to claim 1,
And forming a rust preventive film on the nodular layer. 10. The method of claim 9,
Wherein the rustproofing film comprises at least one of chromium, benzotriazole (BTA) and silane compounds. A copper layer having a matte side and a shiny side opposite thereto; And
And a nodule layer disposed on at least one of the matte surface and the shiny surface, the nodule layer having a plurality of nodules,
A copper foil having a gloss (Gs 60 deg.) Of 6 or more and less than 30. 12. The method of claim 11,
Wherein the nodule has a maximum diameter of 0.5 mu m or less. 12. The method of claim 11,
In the nodule,
Copper (Cu); And
At least one of nickel (Ni), iron (Fe), tungsten (W) and molybdenum (Mo);
≪ / RTI > 12. The method of claim 11,
Wherein the copper foil has a first surface in the matte surface direction and a second surface in the shiny surface direction,
Wherein at least one of the first surface and the second surface has a gloss degree (Gs 60 deg.) Of 6 or more and less than 30. 15. The method of claim 14,
Wherein the first surface and the second surface each have a surface roughness (Rz JIS) of 0.7 mu m to 3.0 mu m. 16. The method of claim 15,
Wherein the first surface and the second surface have a surface roughness (Rz JIS) difference of less than 0.5 mu m. 12. The method of claim 11,
A copper foil having a thickness of 4 탆 to 35 탆. 12. The method of claim 11,
Further comprising a rustproofing film on the nodular layer,
Wherein the rustproofing film comprises at least one of chromium, benzotriazole (BTA) and silane compounds. The copper foil according to any one of claims 11 to 18, And
An active material layer on the copper foil;
And an electrode for a secondary battery. A cathode and an anode opposing each other;
An electrolyte for providing an environment in which ions can move between the anode and the cathode; And
A separator for electrically insulating the anode and the cathode; / RTI >
And the negative electrode comprises the electrode for a secondary battery according to claim 19.

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