KR20200050769A - Electrolytic Fe-Ni Alloy Foil for Secondary Battery and Manufacturing Method Thereof - Google Patents

Abstract

The present invention provides an electrolytic iron-nickel (Fe-Ni) alloy foil having high strength and durability for a secondary battery and a manufacturing method thereof. According to the present invention, the electrolytic Fe-Ni alloy foil comprises: an electrolytic Fe-Ni alloy foil consisting of 36 to 50 wt% of Ni and the balance of Fe and inevitable impurities; and a copper-plated layer formed on the electrolytic Fe-Ni alloy foil and having a thickness of 0.1 to 5.0 μm with respect to both surfaces. When a sum of the thickness (T_Fe-Ni) of the electrolytic Fe-Ni alloy foil and the thickness (T_Cu) of the copper-plated layer is the total thickness (T_total), the total thickness (T_total) is 4 to 20 μm and a ratio (T_Cu/T_total) of the thickness (T_Cu) of the copper-plated layer to the total thickness (T_total) is 0.5 or less.

Description

Electrolytic Fe-Ni Alloy Foil for Secondary Battery and Manufacturing Method Thereof

The present invention relates to a copper-plated electrolytic iron-nickel alloy foil used as a negative electrode current collector for a lithium secondary battery.

In recent years, the lithium secondary battery industry has become increasingly important as it is positioned as a core technology in various applications ranging from electric vehicles and energy storage to robots, as well as small phones and laptops. Accordingly, high capacity, high power, long life, efficiency, and low price are becoming important.

In the case of a lithium secondary battery In the reaction to charge and discharge lithium ion battery is a lithium ion (Li ⁺⁾ and electrons (e ^-) which was in the positive (+) when it is this charge is negative (-) enters the plate, whereas the discharge In this case, lithium ions and electrons in the negative electrode move to the positive electrode. Currently, the negative electrode is made of a current collector in which a negative electrode active material is applied to a negative electrode base material (Cu), and an electrolytic copper foil and a rolled copper foil are used as the material of the negative electrode current collector. However, in the case of a rolled copper foil, the manufacturing cost is high, and there is difficulty in manufacturing a large width, and thus, electrolytic copper foil is mainly used as a negative electrode current collector material.

Since the copper foil used as a negative electrode current collector for a lithium secondary battery has low strength, deformation due to temperature and external force is likely to occur in the manufacturing process of applying the active material. Therefore, in order to manufacture a current collector with high shape accuracy, excellent quality control (high strength, plate shape) of copper foil is required. If the quality control for copper foil is insufficient, the copper foil may break in the active material application process, or the active material may be unevenly applied due to wrinkles, wrinkles, or the like to cause defects. In addition, the active material applied to the surface of the current collector is deformed by the external impact of the lithium secondary battery, and damage to the current collector is likely to occur. In addition, a change in the volume of the active material and a heat generation phenomenon due to overcharge occur due to the charge / discharge cycle according to the use of the battery product. When this phenomenon occurs, if the strength of the current collector is low, damage is caused.

Meanwhile, in order to realize a high capacity of the battery, it is required that the discharge capacity per unit volume of the current collector is large. To this end, it is advantageous that the active material applied to the surface of the copper foil is present at a high density, and in order to increase the density of the active material layer, it is important to strengthen the roll press after applying the active material. However, in the case of the existing electrolytic copper foil, it is difficult to increase the density to a higher level with low tensile strength. In addition, in the case of a copper foil having a low tensile strength, a difference in thickness occurs between the center portion and the edge of the active material coating due to plastic deformation during roll pressing, resulting in a problem of shape defects or deterioration of dimensional accuracy.

Electrolytic copper foil can increase the capacity by applying a large amount of active material as the thickness is thinner, but in the prior art, it is difficult to handle due to the decrease in strength according to the thin thickness, and has a problem of reduced productivity and yield due to fracture. In addition, in the case of a metal-based (Si, Sn) active material that is attracting attention for high-capacity use, the volume expansion is severe.

According to the above-mentioned problems, a high-strength negative electrode current collector that is not deformed even in a high rolling-down amount is required. In particular, in the case of ultra-thin (thin) copper foil, tensile strength characteristics are becoming very important, and the demand for high-strength ultra-thin copper foil increases. It is doing.

In order to overcome the above-mentioned problems of the prior art, in the present invention, as one of the element technologies that can contribute to the high capacity of a lithium secondary battery, copper plated electrolytic iron-nickel alloy foil for high strength and durability is higher than commercial electrolytic copper foil and for durability. It is intended to provide a manufacturing method.

The subject of the present invention is not limited to the above. Those of ordinary skill in the art to which the present invention pertains will have no difficulty in understanding additional problems of the present invention from the general details of the present specification.

According to an aspect of the present invention, in weight percent, Ni: 36-50%, the balance of Fe and other inevitable impurities electrolytic iron-nickel alloy foil; And a copper plating layer formed on the electrolytic iron-nickel alloy foil and having a thickness of 0.1 to 5.0 μm on both sides; When the sum of the thickness of the electrolytic iron-nickel alloy foil (T _Fe-Ni ) and the thickness of the copper plating layer (T _Cu ) is called the _total thickness (T _total ), the total thickness (T _total ) is 4 A copper plated electrolytic iron-nickel alloy foil is provided that is ˜20 μm and has a ratio (T _Cu / T _total ) of the thickness (T _Cu ) of the copper plating layer to the _total thickness (T _total ) of 0.5 or less.

A chromate-treated rust-preventing layer may be formed on the copper plating layer.

A surface roughness (Rz) of the copper-plated electrolytic iron-nickel alloy foil may be 2 μm or less.

The copper-plated electrolytic iron-nickel alloy foil may have a tensile strength of 0.8 to 1.6 GPa and an elongation of 1 to 12%.

According to another aspect of the present invention, using electroforming, 5-20 g / L iron ions, 20-50 g / L nickel ions, 30 g / L or less (excluding 0) sodium, 5 g / An electrolytic iron-nickel alloy foil manufacturing step for producing an alloy foil with an iron-nickel alloy foil electrolyte consisting of boron of L or less (excluding 0), saccharin of 0.8 to 3 g / L and residual solvent; And 30 to 100 g / L of copper ions, 70 to 150 g / L of sulfuric acid, 30 ppm or less of chlorine, and a residual solvent. An electrolytic solution for copper plating, wherein the electrolytic iron-nickel alloy foil has a double-sided standard of 0.1 to 5.0 µm. Copper plating step of copper plating to a thickness; A method of manufacturing a copper-plated electrolytic iron-nickel alloy foil is provided.

After the copper plating step, the copper plating electrolytic iron-nickel alloy foil may be further immersed in an rust preventing solution containing chromic acid to further include a rust preventing step of chromating.

In the electrolytic iron-nickel alloy foil manufacturing step, the saccharin may be added at 1.0 to 2.0 g / L.

In the electrolytic iron-nickel alloy foil manufacturing step, electroplating may be carried out at an electrolyte temperature of pH 1.0 to 3.0, 45 to 70 ° C, a current density of 10 to 100 A / dm ² and a flow rate of 10 to 100 m ³ / hr. .

In the copper plating step, copper plating may be performed at an electrolyte temperature of 30 to 60 ° C. and a current density of 10 to 50 A / dm ² .

The present invention has an effect that it is possible to provide a material for a negative electrode current collector having a higher strength than a conventional copper foil by appropriately controlling the thickness of the iron-nickel alloy foil and the copper plating layer on both surfaces of the electrolytic iron-nickel alloy foil. In addition, by providing a high-strength negative electrode current collector material, it is possible to obtain not only a high capacity of the battery, but also an effect that can contribute to improved durability and long life.

Various and beneficial advantages and effects of the present invention are not limited to the above, and will be more readily understood in the course of describing the specific embodiments of the present invention.

The drawings attached to the present specification illustrate preferred embodiments of the present invention, and serve to further understand the technical idea of the present invention together with the detailed description of the present invention, and therefore, the present invention is limited to interpretations described in those drawings. It should not be.
1 is a cross-sectional view of a copper-plated electrolytic iron-nickel alloy foil manufactured according to the manufacturing method of the present invention.
Figure 2 is a schematic view showing an apparatus for manufacturing an electrolytic iron-nickel alloy foil using an electroforming method.
3 is a schematic view showing an apparatus for forming a copper plating layer and an anti-corrosion layer on both sides of an electrolytic iron-nickel alloy foil.

The present inventors provide a high-strength, high-durability alloy foil that can be suitably used as a negative electrode current collector material for lithium secondary batteries when copper is plated on both sides of the iron-nickel alloy foil manufactured using electroforming. It has been confirmed that it can, and has come to the completion of the present invention.

Hereinafter, a copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention will be described in detail. On the other hand, in the present invention, it should be noted that, unless otherwise specified, when referring to the content of each element, it means weight percent.

[Copper plated electrolytic iron-nickel alloy foil]

The copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention includes an electrolytic iron-nickel alloy foil 101 and a copper plating layer 102 formed on both surfaces of the electrolytic iron-nickel alloy foil.

The electrolytic iron-nickel alloy foil may be prepared by electroforming, and in weight percent, Ni: 36-50%, balance Fe and other inevitable impurities. When the nickel content is less than 36%, plating may not be smooth and blacking or tearing may occur. On the other hand, when the nickel content exceeds 50%, there is a problem in that the manufacturing cost increases and cannot be suitably used as a material for a negative electrode current collector of a lithium secondary battery. Therefore, the nickel content of the electrolytic iron-nickel alloy foil of the present invention is preferably limited to 36-50%.

In the electrolytic iron-nickel alloy foil, the rest of the components except for the nickel content are Fe. However, in the normal manufacturing process, impurities that are not intended from the raw material or the surrounding environment may be inevitably mixed, and therefore cannot be excluded. Since these impurities are known to anyone skilled in the ordinary manufacturing process, they are not specifically mentioned in this specification.

Meanwhile, a copper plating layer may be formed on both sides of the electrolytic iron-nickel alloy foil. The copper plating layer may be formed using a conventionally known method such as vapor deposition (sputtering, gas phase chemistry, heat, etc.), electroless copper plating, and is preferably formed through electroplating, but is not limited thereto.

The thickness (T _Cu ) of the copper plating layer is preferably 0.1 to 5.0 μm on both sides. If the thickness (T _Cu ) of the copper plating layer is less than 0.1 μm, the absolute amount of copper having high conductivity is small, and defects such as pinholes are generated, which makes it difficult to stably maintain a high discharge capacity of the secondary battery. On the other hand, when the thickness (T _Cu ) of the copper plating layer exceeds 5.0 μm, it is difficult to suppress the plastic deformation of the copper plating layer in the roll press process, which is one of the secondary battery manufacturing processes, thereby realizing high density of the active material layer while maintaining high dimensional accuracy. It becomes difficult. Therefore, the thickness (T _Cu ) of the copper plating layer may be 0.1 to 5.0 μm, and in some cases, may be 1.0 to 2.0 μm.

As another embodiment of the present invention, an antirust layer may be additionally formed on the copper plating layer. The anti-corrosion layer may be formed by immersing copper-plated electrolytic iron-nickel alloy foil in an anti-corrosive solution containing chromic acid as a main component, but is not limited thereto. The anti-rust effect can be obtained by subjecting the copper-plated electrolytic iron-nickel alloy foil to an anti-rust treatment.

When the thickness of the electrolytic iron-nickel alloy foil is T _Fe-Ni , the thickness of the copper plating layer is T _Cu , and the total thickness of the thickness of the electrolytic iron-nickel alloy foil and the thickness of the copper plating layer is T _total , T _total May be 4-20 μm. If an anti-rust layer is formed on the copper plating layer through a chromate treatment, the total thickness (T _total ) also includes the thickness of the anti-rust layer. If the total thickness (T _total ) is less than 4 μm, the material is easily broken, which causes difficulty in continuous winding as well as a problem in handling. On the other hand, when the total thickness (T _total ) exceeds 20 μm, there is a limit to realizing high capacity of the secondary battery. Therefore, the total thickness T _total may be 4 to 20 μm, and in some cases, 6 to 10 μm.

Meanwhile, a ratio (T _Cu / T _total ) of the thickness T _Cu of the copper plating layer to the _total thickness T _total may be 0.5 or less. When the ratio of the thickness is 0.5 or less, the plastic strain of the copper plating layer can be effectively constrained by the electrolytic iron-nickel alloy foil during roll pressing, thereby realizing a cathode current collector with high dimensional accuracy. Therefore, in the present invention, the ratio (T _Cu / T _total ) of the thickness (T _Cu ) of the copper plating layer to the total thickness (T _total ) may be 0.5 or less, and in some cases, it is more preferably 0.3 or less. The lower limit of the thickness ratio may not be limited, but the lower limit of the ratio of the thickness is 0.005 or more in consideration of the maximum value of 20 μm of the _total thickness T _total and the minimum value of 0.1 μm of the thickness of the copper plating layer T _Cu . Can be done with

The copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention having the above-described configuration may satisfy the condition (JISB0601-1994 standard) required as a material for a negative electrode current collector having a surface roughness (Rz) of 2 μm or less. have. If the surface roughness (Rz) exceeds 2 µm, the surface may be non-uniform, resulting in a difference in the thickness of the negative active material coating.

In addition, the copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention has a tensile strength of 0.8 to 1.6 GPa and an elongation of 1 to 12%.

Hereinafter, a method of manufacturing a copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention will be described in detail.

[Method for manufacturing copper-plated electrolytic iron-nickel alloy foil]

Method of manufacturing a copper-plated electrolytic iron-nickel alloy foil according to an aspect of the present invention by using electroforming, in weight percent, Ni: 36-50%, the balance is Fe and an alloy containing unavoidable impurities An electrolytic iron-nickel alloy foil manufacturing step of manufacturing the foil; And a copper plating step of copper plating on both sides of the electrolytic iron-nickel alloy foil to a thickness of 0.1 to 5.0 μm on both sides.

Electrolytic iron-nickel alloy foil manufacturing step

FIG. 2 schematically shows an apparatus for manufacturing an iron-nickel alloy foil using an electroforming method. Referring to FIG. 2, the apparatus is provided with a rotating cylindrical cathode drum 12 installed in the electrolytic cell 11 and a pair of arc-shaped insoluble anodes 13 opposed thereto, and the cathode drum ( 12) and a liquid supply part 14 for supplying the electrolyte to the gap surrounded by the insoluble anode 13 is provided. Here, when the electrolyte is supplied through the liquid supply part 14 and the electric current is supplied to the gap, a Fe-Ni-based alloy is electrodeposited on the surface of the cathode drum 12, and this is separated and wound up to obtain an electrolytic iron-nickel alloy foil. It can be easily manufactured.

The electrolytic iron-nickel alloy foil manufactured by the electroplating method has an advantage in that the average grain size is fine, and thus has excellent mechanical properties, and furthermore, it is possible to manufacture a material having a thin thickness at a low cost.

The electrolytic solution for iron-nickel alloy foil used in the electroplating method is an electrolytic solution containing an iron compound and a nickel compound, wherein the electrolytic solution is 5-20 g / L iron ion, 20-50 g / L nickel ion, 30 g / L or less ( Sodium, 5 g / L or less (excluding 0), boron, 0.8-3 g / L saccharin, and residual solvent. In addition, the solvent is preferably pure water, more preferably ultrapure water may be used.

Iron ion: 5 to 20 g / L, nickel ion: 20 to 50 g / L

The concentration of iron ions and the concentration of nickel ions in the electrolyte is determined by the components of the iron-nickel alloy foil to be produced. If the concentration of iron ions and the concentration of nickel ions are lower than the above-described range, a problem occurs in that the nickel component is too low in the iron-nickel alloy foil, while the concentration of iron ions and the concentration of nickel ions are higher than the above range. The metal ions in the electrolytic solution become excessively high, making it impossible to provide an iron-nickel alloy foil containing an intended amount of nickel.

In addition, iron ions of the above-described concentration may be used by dissolving them in the form of salts such as iron sulfate, iron chloride, and iron sulfate, or by supplying electrolytic iron or iron powder in hydrochloric acid or sulfuric acid. In addition, nickel ions of the above-described concentration may be used in the form of salts such as nickel chloride, nickel sulfate, and nickel sulfamate, or may be supplied by dissolving ferronickel in the acid.

Sodium: 30g / L or less (excluding 0)

In the electrolyte solution for iron-nickel alloy foil according to the present invention, sodium may be included at a concentration of 30 g / L or less (excluding 0). Sodium can be added to control the proper cell voltage because it can reduce the cell voltage of the cathode, anode, and electrolyte by reducing the resistance of the electrolyte. have. However, if the concentration of sodium exceeds 30 g / L, the cell voltage may be lowered, but there is a problem in that a target product cannot be manufactured due to a red powder phenomenon. Effect can be obtained.

Boron: 5g / L or less (excluding 0)

The boron is a component that is added to maintain the pH of the electrolyte solution for iron-nickel alloy foils, and the desired effect can be obtained when it is preferably added at 5 g / L or less. The pH of the electrolyte solution for iron-nickel alloy foil is an important factor affecting not only the electrolyte solution itself, but also the overall properties of the product. Particularly, it is very important to keep the pH at a constant value because the area around the cathode is a region where the local pH is easily changed. If the concentration of boron exceeds 5 g / L, a surface quality defect problem may occur where white stains are formed on the surface.

Saccharin: 0.8 ~ 3g / L

The saccharin can be included in the electrolyte solution for iron-nickel alloy foils to lower the surface roughness of the iron-nickel alloy foil and increase the tensile strength. When the iron-nickel alloy foil is manufactured through the electroforming method, if stress is concentrated on the plated surface, it is discharged and interferes with crystallization of the adsorbed element, so it appears as a powdering phenomenon in appearance. You won't get noodles. In order to prevent this, in one embodiment of the present invention, it is characterized in that it contains saccharin in the electrolyte as a structure for alleviating stress and minimizing grains to increase tensile strength.

When saccharin is added at 0.8 to 3 g / L, a desired effect can be obtained. If the content of saccharin is less than 0.8 g / L, the product cannot be manufactured by a powdering phenomenon, whereas when it exceeds 3 g / L, curl occurs in the alloy foil due to variation in thickness direction components. Therefore, in the present invention, saccharin included in the electrolyte solution for iron-nickel alloy foil may be added at 0.8 to 3 g / L, preferably 1.0 to 2.0 g / L, and more preferably 1.2 to 1.5 g / L. .

According to one embodiment of the present invention, in the preparation of the iron-nickel alloy foil, electroplating is pH 1.0-3.0, electrolyte temperature of 45-70 ° C, current density of 10-100 A / dm ² and 10-100 m3 / hr. It can be carried out on the condition that the flow rate of.

First, it is preferable that the electrolyte for the iron-nickel alloy foil having the above-described composition has a pH of 1.0 to 3.0. When the pH of the electrolyte solution for the iron-nickel alloy foil is less than 1.0 or exceeds 3.0, it is not easy to manufacture the iron-nickel alloy foil using the electroforming method. Therefore, it is preferable to control the pH of the electrolyte solution for the iron-nickel alloy foil to 1.0 to 3.0.

In addition, if the temperature of the electrolyte exceeds 75 ° C or the flow rate is less than 10 m 3 / hr, the nickel composition in the alloy foil is lowered, whereas when the temperature is less than 45 ° C. or the flow rate exceeds 100 m 3 / hr, the nickel composition increases. Can be.

In addition, if the current density is lower than 10A / dm ² , the work speed is too slow, and accordingly, productivity is deteriorated. On the other hand, if the current density exceeds 100 A / dm ^{2, the} stress increases, and the overvoltage required for the high current density increases, and the side reactions on the anode and cathode surfaces are relatively increased in addition to the main reaction. Due to this, the current efficiency is lowered, and there is a problem that deterioration of the electrodeposited materials such as burning and hydrogen embrittlement occurs. Therefore, it is preferable that the current density when manufacturing the iron-nickel alloy foil is 10 to 100 A / dm ² .

Copper plating step and rust prevention step

3 shows a schematic configuration of an apparatus for performing copper plating and rust prevention according to a preferred embodiment of the present invention. Referring to FIG. 3, a copper plating bath 201 for copper plating on both surfaces of the iron-nickel alloy foil 101 and an antirust plating bath 202 capable of chromating with chromic acid as a main component are provided. .

The electrolytic iron-nickel alloy foil 101 manufactured by the aforementioned electroforming method is plated and rust-prevented by electroplating by successively passing through the copper plating bath 201 and optionally the anti-rust plating bath 202 in sequence.

Specifically, the electrolytic iron-nickel alloy foil 101 is guided to the inside of the copper plating bath 201 by the guide roll 203 to be copper-plated. Thereafter, the copper-plated iron-nickel alloy foil can be selectively subjected to chromate treatment on the surface through an immersion process in a rust-preventing liquid containing chromic acid as a main component, thereby providing a rust-preventing effect. Finally, the copper-plated electrolytic iron-nickel alloy foil 100 is wound up by a winding roll 204.

The copper plating may be performed by applying a copper plating method commonly used in the prior art. However, as a non-limiting example, the electrolytic solution for copper plating used in copper plating according to the present invention may be made of 30 to 100 g / L copper ions, 70 to 150 g / L sulfuric acid, 30 ppm or less of chlorine, and a residual solvent. . In addition, the solvent is preferably pure water, more preferably ultrapure water may be used.

In addition, according to one embodiment of the present invention, the copper plating may be carried out under an electrolyte temperature of 30 to 60 ° C. and a current density of 10 to 50 A / dm ² .

Hereinafter, the present invention will be described in more detail through examples. However, it is necessary to note that the following examples are only intended to exemplify the present invention and are not intended to limit the scope of the present invention. This is because the scope of the present invention is determined by matters described in the claims and reasonably inferred therefrom.

(Example)

First, an electrolytic iron-nickel alloy foil was manufactured using the electroforming apparatus shown in FIG. 2. At this time, 11.0 g / L of iron ions, 31.5 g / L of nickel ions, 25 g / L of sodium, 2.5 g / L of boron, 1.3 g / L of saccharin, and an electrolyte solution containing pure water are used as the electrolyte. Became. In addition, an alloy foil was prepared by supplying the electrolytic solution to the electroplating apparatus at a flow rate of 35 m 3 / hr under the condition that the pH of the electrolytic solution was 2.0, the temperature was 55 ° C., and the current density was 30 A / dm ² .

Thereafter, copper plating and rust prevention treatment were performed on both surfaces of the prepared electrolytic iron-nickel alloy foil using the electroplating apparatus shown in FIG. 3. As the electrolytic solution for copper plating, 50 g / L copper ion, 100 g / L sulfuric acid, 15 ppm chlorine ion, and an electrolyte solution containing pure water as a residual solvent were used. When plating, the temperature was 40 ° C and the current density was 20 A / dm ² Plating was performed under phosphorus conditions. And after passing through the copper plating to pass through the anti-corrosion plating bath to form an anti-corrosion layer, it was finally wound up.

Meanwhile, as a comparative example for comparison with the present invention, a copper foil widely used as a current collector for a secondary battery is prepared. Comparative Example 1 is a product of ILJIN Materials, and Comparative Example 2 is a product of KCFT.

After the specimens were prepared according to ASTM-SUB standards for the copper-plated electrolytic iron-nickel alloy foil and the copper foil of the comparative example, tensile was performed using a fine tensile tester based on a strain speed of 1 µm / sec. The strength and elongation were measured, and the results are shown in Table 1. In addition, the surface roughness of Rz was measured according to the JISB0601-1994 standard, and the results are shown in Table 1.

division Thickness (㎛) T _Cu / T _total Surface roughness
(Rz, ㎛) The tensile strength
(GPa) Elongation
(%) T _total T _Fe-Ni T _Cu Inventive Example 1 6 5 One 0.167 1.13 0.98 2.2 Inventive Example 2 8 6 2 0.250 1.21 1.07 2.4 Inventive Example 3 10 8 2 0.200 1.27 1.24 2.8 Comparative Example 1 6 - 6 1.000 1.45 0.52 2.4 Comparative Example 2 6 - 6 1.000 1.32 0.42 6.2

Comparative Examples 1 and 2 are commercially available electrolytic copper foils that are currently used as negative electrode current collectors for secondary batteries, and it can be seen that the tensile strength was less than 0.8 GPa and the strength was weak.

On the other hand, Inventive Examples 1 to 3 are examples prepared by conducting copper plating on the electrolytic iron-nickel alloy foil according to the manufacturing method of the present invention, and it was possible to obtain a high strength alloy foil for a secondary battery having a tensile strength of 0.8 GPa or more.

Although described with reference to the above embodiments, those skilled in the art understand that various modifications and changes can be made to the present invention without departing from the spirit and scope of the present invention as set forth in the claims below. Will be able to.

100 copper plated electrolytic iron-nickel alloy foil
101 Electrolytic iron-nickel alloy foil
102 copper plating layer
11 Electrolyzer
12 cathode drum
13 Insoluble anode
14 Payment section
201 copper plating bath
202 Anti-rust plating bath
203 guide roll
204 winding roll

Claims (9)

A copper-plated electrolytic iron-nickel alloy foil,
In weight percent, Ni: 36-50%, the balance of Fe and other inevitable impurities, an electrolytic iron-nickel alloy foil; And
A copper plating layer formed on the electrolytic iron-nickel alloy foil and having a thickness of 0.1 to 5.0 μm on both sides;
It includes,
When the sum of the thickness of the electrolytic iron-nickel alloy foil (T _Fe-Ni ) and the thickness of the copper plating layer (T _Cu ) is called the _total thickness (T _total ), the total thickness (T _total ) is 4 to 20 μm, ,
The copper-plated electrolytic iron-nickel alloy foil in which the ratio (T _Cu / T _total ) of the thickness (T _Cu ) of the copper plating layer to the _total thickness (T _total ) is 0.5 or less.
According to claim 1,
Copper plated electrolytic iron-nickel alloy foil, characterized in that a rust-prevented chromate layer is formed on the copper plated layer.
According to claim 1,
A copper-plated electrolytic iron-nickel alloy foil, characterized in that the surface roughness (Rz) of the copper-plated electrolytic iron-nickel alloy foil is 2 µm or less.
According to claim 1,
The copper-plated electrolytic iron-nickel alloy foil is copper-plated electrolytic iron-nickel alloy foil, characterized in that the tensile strength is 0.8 to 1.6 GPa, and the elongation is 1 to 12%.
A method for manufacturing copper-plated electrolytic iron-nickel alloy foil,
5-20 g / L iron ions, 20-50 g / L nickel ions, 30 g / L or less (excluding 0) sodium, and 5 g / L or less (excluding 0) boron using electroforming , 0.8 ~ 3g / L of an iron-nickel alloy foil manufacturing step of producing an alloy foil with an electrolyte for an iron-nickel alloy foil consisting of saccharin and the balance solvent; And
An electrolytic solution for copper plating consisting of 30 to 100 g / L copper ions, 70 to 150 g / L sulfuric acid, 30 ppm or less of chlorine, and a residual solvent, with a thickness of 0.1 to 5.0 µm on both sides of the electrolytic iron-nickel alloy foil. Copper plating step of copper plating with;
Method for producing a copper-plated electrolytic iron-nickel alloy foil comprising a.
The method of claim 5,
After the copper plating step, the copper-plated electrolytic iron-nickel alloy foil is immersed in an rust-preventing solution containing chromic acid, and further comprising a rust-preventing step for chromating the copper-plated electrolytic iron-nickel alloy foil. .
The method of claim 5,
In the electrolytic iron-nickel alloy foil manufacturing step,
The saccharin is a method for producing copper-plated electrolytic iron-nickel alloy foil, characterized in that it is added at 1.0 to 2.0 g / L.
The method of claim 5,
In the electrolytic iron-nickel alloy foil manufacturing step,
Electroplated electroplating is copper-plated electrolytic iron-nickel alloy foil characterized in that it is carried out at a pH of 1.0 to 3.0, an electrolyte temperature of 45 to 70 ° C, a current density of 10 to 100 A / dm ² and a flow rate of 10 to 100 m3 / hr. Method of manufacturing.
The method of claim 5,
In the copper plating step,
Copper plating is a method of manufacturing a copper-plated electrolytic iron-nickel alloy foil, characterized in that it is carried out at an electrolyte temperature of 30 to 60 ° C and a current density of 10 to 50 A / dm ² .

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