JPWO2013021969A1 - Rolled copper foil for secondary battery negative electrode current collector and method for producing the same - Google Patents

Abstract

There are provided a rolled copper foil for a secondary battery current collector and a method for producing the same, which are difficult to plastically deform due to a large amount of elastic deformation, and can improve the yield and electrical characteristics of a battery or the like. A rolled copper foil 20 for a secondary battery current collector made of copper or a copper alloy formed by rolling, wherein the area ratio S (111) of the region whose (111) plane faces in the rolling direction with respect to the crystal orientation, and in the rolling direction The area ratio [S (111) / S (100)] with the area ratio S (100) of the region facing the (100) plane is 2 or less.

Description

  The present invention relates to a rolled copper foil applicable to a current collector for a secondary battery and a method for producing the same, and more particularly, to a rolled copper foil having an expanded elastic limit and a method for producing the same.

  The rolled copper foil is used for a negative electrode current collector of a secondary battery such as a lithium ion battery. For example, a rolled active material is applied with a carbon-based active material. Such a negative electrode current collector is manufactured by applying an active material to a rolled copper foil by a roll press. However, in the press using a roll, there is a problem that the copper foil is deformed and the active material is dropped or the yield is lowered due to the shape defect. In recent years, the current collector has been made thinner, and this problem has become more prominent.

In addition, with the recent demand for battery capacity improvement, changes from carbon-based to silicon (Si) -based or tin (Sn) -based active materials are being studied.
However, these new active materials have a problem that they are detached from the current collector during use because the amount of expansion / contraction caused by charging / discharging is larger than that of carbon. This is considered to be one of the causes that the current collector is plastically deformed when the active material expands.

  Against the backdrop of further demands for improving battery capacity in recent years, the detachment of the active material is the main cause of capacity reduction, and since active materials with large expansion and contraction such as Si-based and Sn-based materials are expected to be applied. Its importance is increasing.

  As described above, since plastic deformation of the rolled copper foil for a battery becomes a problem during the manufacturing process and in use, it is required to increase the critical elastic deformation amount. In order to increase the critical elastic deformation amount, it is necessary not only to increase the yield stress but also to decrease the longitudinal elastic modulus (Young's modulus) with respect to the tensile stress.

Several proposals have been made for improving the mechanical properties of rolled copper foil (see, for example, Patent Documents 1 to 6).
In Patent Document 1, it is proposed to increase the tensile strength by alloying. If tensile strength is high, it is estimated that the yield stress is also high.
Patent Document 2 proposes increasing the tensile strength of the current collector. If tensile strength is high, it is estimated that the yield stress is also high.
Patent Document 3 proposes increasing the Young's modulus after softening the copper alloy foil by heat treatment at 300 ° C. for 30 minutes.
Patent Document 4 shows that the Young's modulus decreases by rolling a copper sheet of pure copper at a rolling rate of 96% and increasing the cube texture by heat treatment at 250 ° C. for 1 hour.
Patent Documents 5 and 6 propose a method of reducing the Young's modulus with respect to the tensile stress of a material by controlling the amount of Zn and the amount of Sn.

JP 11-339811 A WO2001 / 031723 publication JP 2009-2442846 A JP 55-055454 A JP 2001-294957 A JP 2003-306732 A

By the way, in the copper foil disclosed by the said patent document 1 and 2, only the yield stress was raised, and the longitudinal elastic modulus with respect to the tensile stress was not able to be lowered.
In addition, the copper foil disclosed in Patent Document 3 has a low yield stress because it has been softened, and also has a narrow limit elastic deformation amount in order to increase the longitudinal elastic modulus against tensile stress.
In the copper foil disclosed in Patent Document 4, since it is after being softened, the yield stress is low, so that it is insufficient for expanding the limit elastic deformation amount.
In the copper foils disclosed in Patent Documents 5 and 6, the electrical conductivity was remarkably reduced due to the large amount of solid solution elements.
Therefore, these copper foils may not be able to satisfy the advanced requirements for batteries in recent years.

  An object of the present invention is to provide a rolled copper foil for a secondary battery current collector that is difficult to be plastically deformed due to its large amount of elastic deformation, and that can improve the yield of the manufacturing process of batteries and the electrical characteristics of the product. And providing a manufacturing method thereof.

  In the present invention, the longitudinal elastic modulus with respect to the tensile stress is controlled by controlling the crystal orientation of the rolled copper foil. Moreover, especially about the manufacturing method before performing the rolling process to foil, it showed that control of a hot rolling process was very effective for control of crystal orientation.

According to the present invention, a rolled copper foil for a secondary battery current collector made of copper or a copper alloy formed by rolling, wherein the area ratio S (111) of the region whose (111) plane faces in the rolling direction with respect to the crystal orientation And the rolled copper foil whose area ratio [S (111) / S (100)] of the area ratio S (100) of the area | region where a (100) surface turns to a rolling direction is 2 or less is provided.
Here, the area ratio is calculated by dividing (dividing) the area of the region whose deviation angle from the ideal orientation is within 15 ° by the total measurement area.
Moreover, although a rolled copper foil may mean the rolled foil of pure copper, in this application, it widely means the rolled foil of a copper alloy.

Preferably, the rolled copper foil is a Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, and at least one of Cr and Zr as main components is included. A total of 0.01-0.9 mass% is contained.
Moreover, the Cu- (Cr, Zr) -based rolled copper foil may contain 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg as auxiliary additives. .
In addition, the Cu- (Cr, Zr) -based rolled copper foil is formed with inevitable impurities in the remainder excluding the main component, or the remainder excluding the main component and the auxiliary additive component.

Preferably, the rolled copper foil is a Cu-Ag copper alloy containing Ag as a main component, and contains 0.01 to 0.9 mass% of Ag as a main component.
In addition, the Cu-Ag-based rolled copper foil may contain 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg serving as auxiliary additives.
In the Cu-Ag-based rolled copper foil, the remaining part excluding the main component or the remaining part excluding the main component and the auxiliary additive component is formed by inevitable impurities.

Preferably, the rolled copper foil is a Cu—Sn based copper alloy containing Sn as a main component, and contains 0.01 to 4.9 mass% of Sn as a main component in total.
In addition, the Cu—Sn-based rolled copper foil may contain 0.01 to 0.45 mass% in total of at least one of Zn, Si, P, and Mg serving as auxiliary additives.
In addition, as for the Cu-Sn type rolled copper foil, the remainder except a main component, or the remainder except a main component and a secondary additive component is formed with an unavoidable impurity.

Preferably, the rolled copper foil is a Cu—Ni—Si based copper alloy containing Ni and Si as main components, wherein Ni as a main component is 1.4 to 4.8 mass%, and Si is 0.2. Contains ~ 1.3 mass%.
In addition, the Cu-Ni-Si-based rolled copper foil contains 0.005 to 0.9 mass% in total of at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co, which are auxiliary additives. Also good.
In addition, as for the Cu-Ni-Si type rolled copper foil, the remainder except a main component, or the remainder except a main component and an auxiliary additive component is formed with an unavoidable impurity.

Preferably, the rolled copper foil is pure copper containing oxygen and has an oxygen content of 2 to 200 ppm.
In addition, the remainder of the pure copper-based rolled copper foil is formed of inevitable impurities.

  Moreover, according to this invention, it is a manufacturing method of the rolled copper foil which manufactures any one of above-mentioned rolled copper foils, Comprising: The homogenization which performs a homogenization heat processing with respect to the forged rolling material A heat treatment step, a hot rolling step in which a plurality of high-temperature rollings are performed across the cooling step, and a first cooling step in which post-cooling is performed after the hot rolling step. A chamfering step for chamfering after the first cooling step, an intermediate cold rolling step for performing intermediate cold rolling at a predetermined sheet thickness reduction rate after the chamfering step, and a predetermined temperature after the intermediate cold rolling A final recrystallization annealing step for performing a final recrystallization annealing at a predetermined time, and a final cold rolling step for performing a final cold rolling after the final recrystallization annealing, and the hot rolling step is a recrystallization A first high temperature rolling step of performing a first high temperature rolling at a first heating temperature equal to or higher than the temperature, and the first high temperature A rolled copper comprising: a second cooling step for cooling after performing the rolling; and a second high temperature rolling step for performing second high temperature rolling at a second heating temperature lower than the first heating temperature after the second cooling step. A method of manufacturing a foil is provided.

  Preferably, in the first cooling step, only the cooling is performed without performing the processing.

According to the present invention, since the limit elastic deformation amount of the rolled copper foil as the current collector is large, it is possible to prevent the current collector from being plastically deformed against an external force in the manufacturing process of the secondary battery or the like. Further, this makes it difficult for the active material to fall off from the current collector, so that the capacity of the secondary battery can be improved.
Furthermore, when the rolled copper foil, which is a current collector, deforms due to deformation of an active material such as Sn-based or Si-based material that has a large expansion / contraction during charge / discharge, the deformation of the current collector is within the elastic limit. Therefore, the current collector can follow the shape change of the active material. Therefore, separation of the active material and the current collector can be prevented, and the charge / discharge cycle characteristics of the secondary battery can be improved.

It is a figure which shows schematic structure of the lithium secondary battery with which the rolled copper foil which concerns on embodiment of this invention is applied as a negative electrode collector. It is a figure which expands and shows typically a rolled copper foil concerning an embodiment of the present invention. It is a figure for demonstrating the manufacturing process of the rolled copper foil which concerns on embodiment of this invention. It is a figure which shows the relationship between area ratio [S (111) / S (100)] and the elastic modulus with respect to a lead stress. It is a figure which shows the manufacturing process of a comparative example.

FIG. 1 is a diagram showing a schematic configuration of a lithium secondary battery to which a rolled copper foil according to an embodiment of the present invention is applied as a negative electrode current collector.
FIG. 2 is a schematic enlarged view showing the rolled copper foil according to the embodiment of the present invention.

  A lithium secondary battery 10 in FIG. 1 includes a positive electrode 11, a negative electrode 12, a positive electrode current collector 13, a negative electrode current collector 14, a separator 15, a positive electrode side battery can 16, a negative electrode side battery can 17, and an insulating packing 18. It is configured.

The positive electrode 11 and the negative electrode 12 are disposed so as to face each other with the separator 15 interposed therebetween. The positive electrode 11, the negative electrode 12, and the separator 15 are accommodated in a battery case formed by the positive electrode side battery can 16 and the negative electrode side battery can 17.
In this housed state, the positive electrode 11 is connected to the positive electrode side battery can 16 via the positive electrode current collector 13, and the negative electrode 12 is connected to the negative electrode side battery can 17 via the negative electrode current collector 14.
With this structure, the secondary battery 10 can be charged and discharged.

In the present embodiment, a rolled copper foil 20 as shown in FIG. 2 is applied as the negative electrode current collector 14.
The rolled copper foil 20 according to this embodiment has a thickness d set to 12 μm or less, for example, and is formed with the following characteristics.
The rolled copper foil 20 has an area ratio S [111] of a region where the (111) plane faces in the rolling direction with respect to the crystal orientation and an area ratio S (100) of a region where the (100) plane faces in the rolling direction [ S (111) / S (100)} is 2 or less.
As the crystal orientation, crystal orientation measurement by electron backscatter diffraction (EBSD method) can be applied.
Moreover, the rolled copper foil 20 which concerns on this embodiment is formed as a copper alloy as shown in the following (1)-(5), or a pure copper type | system | group.

(1): Cu— (Cr, Zr) -based copper alloy The rolled copper foil 20 is a Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component. It is formed as a copper alloy containing 0.01 to 0.9 mass% in total of at least one of Cr and Zr as components.
Further, the Cu— (Cr, Zr) -based copper alloy contains 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg as sub-addition components as necessary. It is formed as a copper alloy.
In the Cu— (Cr, Zr) -based copper alloy, the remainder excluding the main component or the remainder excluding the main component and the auxiliary additive component is formed by inevitable impurities.

(2): Cu-Ag-based copper alloy The rolled copper foil 20 is a Cu-Ag-based copper alloy containing Ag as a main component, and 0.01 to 0.9 mass% of Ag as a main component in total. It is formed as a copper alloy containing.
In addition, the Cu-Ag-based copper alloy is formed as a copper alloy containing 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg, which are sub-addition components as necessary. Is done.
In the Cu-Ag-based copper alloy, the remaining part excluding the main component, or the remaining part excluding the main component and the auxiliary additive component is formed by inevitable impurities.

(3): Cu-Sn-based copper alloy The rolled copper foil 20 is a Cu-Sn-based copper alloy containing Sn as a main component, and the total amount of Sn as the main component is 0.01 to 4.9 mass%. It is formed as a copper alloy containing.
In addition, the Cu—Sn based copper alloy is formed as a copper alloy containing 0.01 to 0.45 mass% in total of at least one of Zn, Si, P, and Mg as sub-addition components as necessary. .
In the Cu—Sn-based copper alloy, the remainder excluding the main component or the remainder excluding the main component and the auxiliary additive component is formed by inevitable impurities.

(4): Cu—Ni—Si based copper alloy The rolled copper foil 20 is a Cu—Ni—Si based copper alloy containing Ni and Si as main components, and the main component Ni is 1.4 to It is formed as a copper alloy containing 4.8 mass% and 0.2 to 1.3 mass% of Si.
In addition, the Cu—Ni—Si based copper alloy is 0.005 to 0.9 mass% in total of at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co, which are sub-addition components as necessary. It is formed as a copper alloy containing.
In the Cu-Ni-Si-based copper alloy, the remainder excluding the main component, or the remainder excluding the main component and the auxiliary additive component is formed by inevitable impurities.

(5): Pure copper system containing oxygen (TPC system)
The rolled copper foil 20 is a pure copper-based (TPC-based) copper material containing oxygen, and has an oxygen amount of 2 to 200 ppm, with the remainder being inevitable impurities.

  Here, the unavoidable impurities generally exist in the raw materials in metal products or are inevitably mixed in the manufacturing process. Although it is originally unnecessary, it is a very small amount and is an acceptable impurity because it does not affect the properties of the metal product.

FIG. 3 is a diagram for explaining a manufacturing process of the rolled copper foil 20 according to the present embodiment.
As shown in FIG. 3, the rolled copper foil 20 is manufactured using the first step (step) ST1 to the eleventh step (step) ST11 as a basic step.

The first step ST1 is a melting step for melting the raw material, the second step ST2 is a casting step for casting the molten raw material to form a material to be rolled (ingot), and the third step ST3 is a material for rolling the material to be rolled. This is a homogenization heat treatment step that is a heat treatment for homogenizing the cast structure.
The fourth step ST4 is a first high temperature rolling step, the fifth step ST5 is a cooling step, and the sixth step ST6 is a second high temperature rolling step. A hot rolling process is formed including these first high temperature rolling process, cooling process, and second high temperature rolling process. Hot rolling refers to rolling performed by heating a metal to a recrystallization temperature or higher.
The seventh step ST7 is a water cooling step, the eighth step ST8 is a chamfering step for removing oxide scale, the ninth step ST9 is an intermediate cold rolling step, and the tenth step ST10 is final annealing. The eleventh step ST11 is a final cold rolling step. Note that cold rolling refers to rolling performed in a temperature range (for example, room temperature) where recrystallization does not occur.

  A characteristic process for producing the rolled copper foil 20 according to the present embodiment is that the first high-temperature rolling in the fourth step ST4 is performed at a first heating temperature, for example, 670 ° C. or higher, and the sixth step ST6 The second high temperature rolling is to perform high temperature rolling at a second heating temperature lower than the first heating temperature, for example, 650 ° C. or less.

  Hereinafter, the above-described crystal orientation of the rolled copper foil 20 according to the present embodiment, 0.2% proof stress, manufacturing process for controlling the crystal orientation, and characteristic features such as alloy components will be specifically described, and the above (1) Examples of the copper alloy of (5) will be described in comparison with reference examples and comparative examples.

[Crystal orientation]
In a normal rolled copper foil, a rolled texture is developed. For the problem of lowering the longitudinal elastic modulus with respect to the tensile strength, the rolling texture (rolling stable orientation) of a general copper alloy has a certain spread, but the Brass orientation in which the (112) plane is oriented in the rolling direction. In general, the S orientation in which the (346) plane faces in the rolling direction and the Copper orientation in which the (111) plane faces are common. However, these (112) and (346) plane orientations have no significant effect on the decrease in the longitudinal elastic modulus with respect to the tensile strength, and the (111) plane orientation increases the longitudinal elastic modulus with respect to the tensile strength.
On the other hand, in the embodiment of the present invention, it was confirmed that (100) plane orientation is effective.
In the embodiment of the present invention, the area ratio of the region in which the (100) plane is oriented in the rolling direction is S (100), and the area ratio of the region in which the (111) plane is oriented in the rolling direction is S (111). And reducing the area ratio [S (111) / S (100)] was found to be effective.

4A and 4B are diagrams showing the relationship between the area ratio [S (111) / S (100)] and the longitudinal elastic modulus (Young's modulus) with respect to the tensile strength.
In addition, the longitudinal elastic modulus (Young's modulus) with respect to the tensile strength shown in FIG. 4 was measured as follows. The distance between the gauge points during the short axis tensile test was measured with a camera-type non-contact extensometer, and the strain was measured. The slope of the linear portion of the elastic region in the collected stress-strain curve was measured. As the camera-type non-contact extensometer, DVE-201 (trade name) manufactured by Shimadzu Corporation was used. The extension is measured by automatically tracking the marked line mark from the CCD camera image. The test piece was strip-shaped with a width of 13 mm.

In addition, as a measurement of the longitudinal elastic modulus (Young's modulus) of foil, it may be measured by a vibration method. The vibration method is a measurement method in which a forced vibration is applied, a resonance frequency (natural frequency) is measured, and a Young's modulus is calculated from the resonance frequency. There are some problems in applying this measurement method to a rolled copper foil having a plate thickness of about 10 μm, and there are cases where correct evaluation is difficult. For one thing, there was a problem that because the measurement was performed with a small amount of displacement, the elastic vibration was not stabilized due to slight wrinkles or creases in the specimen, and the evaluation results varied greatly. Secondly, since bending stress is applied, there is a problem that the influence of the irregularities in the vicinity of the deformed foil surface layer is strongly influenced and the influence inside the foil is not reflected. Third, when a rolled copper foil is used as a battery, it is compressed / tensile deformed by the active material applied on both sides, whereas the flexural deformation by the vibration method is that one side is compressed and the other side is tensile. Therefore, the deformation state which is essentially different from the usage environment was to be evaluated. Therefore, in this application, the longitudinal elastic modulus (Young's modulus) was evaluated by a tensile test.
In addition, as described in the Japan Society of Mechanical Engineers, “Technical Data Elastic Modulus of Metallic Materials”, p19 (1980), Maruzen Publishing, the dynamic method represented by the vibration method and the tensile test are representative. It is known that the evaluation result of Young's modulus is different from the static method. Generation | occurrence | production of the difference of this evaluation result is not restricted to foil.

FIG. 4 shows the influence of the area ratio [S (111) / S (100)] on the longitudinal elastic modulus with respect to the tensile strength of the copper alloy. A normal copper alloy has a longitudinal elastic modulus with respect to tensile strength of about 130 GPa, but it has been confirmed that it can be reduced by 20% or more.
In FIG. 4, the area ratio [S (111) / S (100)] is 0.43 to 1.98 of 2 or less, and the longitudinal elastic modulus is 103 to 125 GPa and 130 GPa or less. Further, when the area ratio [S (111) / S (100)] exceeds 2 and 2.2, 2.4, the longitudinal elastic modulus with respect to the tensile strength is 132 GPa, 136 GPa, and tends to increase.
That is, as shown in FIG. 4, by forming the rolled copper foil 20 so that the area ratio [S (111) / S (100)] is 2 or less, an increase in the longitudinal elastic modulus with respect to the tensile strength is suppressed. Can do.

When the area ratio [S (111) / S (100)] was 2 or less, the battery characteristics were excellent as described later.
In other words, by forming the rolled copper foil 20 so that the area ratio [S (111) / S (100)] is 2 or less, an increase in the longitudinal elastic modulus with respect to the tensile strength can be suppressed, which is excellent. Battery characteristics can be obtained.
The ratio [S (111) / S (100)] is preferably 2 or less, more preferably 1.5 or less, and most preferably 1.0 or less. Although a minimum is not specifically limited, It is 0.05 or more.

For the analysis of the crystal orientation in the present embodiment, an EBSD method (Electron Back Scatter Diffraction (electron backscatter diffraction)) is used. EBSD is a crystal orientation analysis technique using reflected electron Kikuchi diffraction (Kikuchi pattern) generated when a sample is irradiated with an electron beam in a scanning electron microscope (SEM).
In the present embodiment, a sample area of 50,000 square μm or more is scanned in 0.2 μm steps and the orientation is analyzed.

The area ratio is calculated by dividing (dividing) the area of the region whose deviation angle from the ideal orientation is within 15 ° by the total measurement area.
The information obtained in the azimuth analysis by the EBSD method includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates into the sample, but is sufficiently small with respect to the measured width. Then, it described as an area ratio.

[0.2% yield strength]
In order to increase the limit elastic deformation, the 0.2% proof stress is preferably 400 MPa or more. More preferably, it is 500 MPa or more, More preferably, it is 600 MPa or more. The design of this strength band depends on the selection of the alloy system described later.
Here, the 0.2% proof stress is defined as follows.
In order to set the boundary between elastic deformation and plastic deformation for the sake of convenience, the stress corresponding to the yield stress is taken as the proof stress, and the permanent strain at yield of the steel is about 0.2% (0.002). The stress at which the permanent set is 0.2% is called 0.2% proof stress.

[Process for controlling crystal orientation]
For example, as shown in Patent Documents 3 and 4, if a cubic texture is developed, the area ratio S (100) of the region in which the rolling direction (100) plane is oriented can be increased.
However, the cubic texture develops by recrystallization and cannot be increased into a processed structure such as a rolled copper foil. An increase in yield strength is indispensable for expanding the limit elastic deformation amount, and work hardening by rolling is indispensable, and the technique of annealing the foil and applying the preferred recrystallization orientation cannot be applied.

  The manufacturing process for controlling to the crystal orientation in which effectiveness was found in embodiment of this invention is shown. As described above, the area ratio of the region in which the (100) plane is oriented in the rolling direction is S (100), and the area ratio of the region in which the (111) plane is oriented in the rolling direction is S (111). As long as these area ratios [S (111) / S (100)] are satisfied, the manufacturing process is not limited thereto.

As a manufacturing process of the rolled copper foil 20 for controlling the crystal orientation, the first process ST1 to the eleventh process ST11 are basic processes as shown in FIG.
That is, a melting process, a casting process, a homogenization heat treatment process, a first high temperature rolling process, a cooling process, a second high temperature rolling process, a water cooling process, a chamfering process, an intermediate cold rolling process, a final recrystallization annealing process, and a final cold process. The manufacturing process consisting of a rolling process is fundamental.

In the manufacturing method of the rolled copper foil 20 according to the present embodiment, the first heating temperature in the first high-temperature rolling is 670 ° C. or higher, more preferably 700 ° C. or higher, and most preferably 730 ° C. or higher.
The second heating temperature in the second high temperature rolling is 650 ° C. or lower, more preferably 620 ° C. or lower, and most preferably 590 ° C. or lower.
The upper limit temperature of the first high temperature rolling is 1030 ° C., and the lower limit temperature of the second high temperature rolling is 300 ° C. The temperature zone between the first high temperature rolling and the second high temperature rolling is not processed and must be cooled by a method such as air cooling or water cooling. The processing rate of the first high temperature rolling is 50 to 80%, and the processing rate of the second high temperature rolling is 30 to 60%.

A feature of the method for producing a rolled copper foil according to the present embodiment is that hot rolling is performed with the first high-temperature rolling (ST4) at a first heating temperature equal to or higher than the recrystallization temperature of copper with the cooling step (ST5) interposed therebetween. The second step is the second high temperature rolling (ST6) at the second heating temperature lower than the first heating temperature.
In normal hot rolling, rolling is performed at a high temperature as much as possible in order to increase the operation efficiency by reducing the rolling load and the number of rolling passes.
On the other hand, in the manufacturing method of the present embodiment, the material is actively cooled between the first high-temperature rolling and the second high-temperature rolling, and a warm rolling structure is formed at a dynamic recrystallization temperature or lower.

[Alloy components]
The effects of the above-described crystal orientation control can be applied to various alloy systems.
Depending on the overall battery design, the required characteristics of the copper foil differ, and an appropriate alloy system may be selected accordingly. The strength and conductivity of the rolled foil are approximately in a trade-off relationship, and the characteristics of each alloy system are as shown in Table 1 below.

In Table 1, the tensile strength of the Cu— (Cr, Zr) -based copper alloy according to the present embodiment is 400 to 700 MPa, and the conductivity is 70 to 95% IACS (International Annealed Copper Standard). It is shown that.
Here, 70% IACS means that the electrical resistance has a conductivity of 70% when the standard annealed copper wire named IACS (International Annealed Copper Wire Standard) is 100%. ing.
The conductivity of this Cu— (Cr, Zr) -based copper alloy is 70 to 95% IACS, and the electrical characteristics are also good.

Similarly, the tensile strength of the Cu-Ag copper alloy according to this embodiment is 350 to 550 MPa, and the conductivity is 80 to 98% IACS.
This Cu-Ag-based copper alloy exhibits high electrical characteristics with conductivity of 80 to 98% IACS.

The tensile strength of the Cu—Sn based copper alloy according to the present embodiment is 400 to 750 MPa, and the conductivity is 15 to 95% IACS.
This Cu-Sn-based copper alloy has a wide range of electrical conductivity of 15 to 95%, but exhibits high electrical (battery) characteristics by optimizing the component addition amount of the main component and sub-addition components. can do.

The tensile strength of the Cu—Ni—Si based copper alloy according to this embodiment is 600 to 1000 MPa, and the conductivity is 20 to 50% IACS.
This Cu-Ni-Si-based copper alloy has a slightly low conductivity of 20 to 50%. However, by optimizing the component addition amount of the main component and sub-addition components, the electricity (battery according to the application) ) It can develop characteristics.

The tensile strength of the pure copper-based (TPC) copper material according to the present embodiment is 350 to 550 MPa, and the conductivity is 95 to 100% IACS.
This pure copper-based copper material exhibits electrical properties as high as 95 to 100% IACS.

When added in excess of the upper limit of the components defined in each of the copper alloys of (1) to (5) above, the coarse size of submicron order in the form of oxide, precipitate, crystallized product, etc. It is not preferable because it is dispersed as two phases and causes pinholes or plate breakage during rolling to a plate thickness of 12 μm or less. Further, it is not preferable because the conductivity is remarkably lowered.
Moreover, when it adds less than the lower limit of the component prescribed | regulated by each of the said copper alloy of (1)-(5), the addition effect is not fully acquired. The component addition amount is appropriately adjusted according to the above-mentioned application.

A preferable range of the total amount of the main components Cr and Zr contained in the Cu— (Cr, Zr) alloy is 0.15 to 0.43 mass%, and a more preferable range is 0.22 to 0.31 mass%.
A preferable range of the Cu-Ag main component Ag is 0.02 to 0.15 mass%, and a more preferable range is 0.03 to 0.05 mass%.
A preferable range of the Cu—Sn-based main component Sn is 0.1 to 2.3 mass%, and a more preferable range is 0.6 to 0.9 mass%.
The preferable range of the Cu-Ni-Si-based main component Ni is 2.1 to 4.2 mass%, and the more preferable range is 3.4 to 3.9 mass%.
In addition to the main components described above, addition of sub-additive elements such as Sn, Zn, Si, Mn, Mg, and P is allowed for the purpose of improving strength and heat resistance.
In particular, in the case of rolling up to a foil having a thickness of 12 μm or less, for the problem that pinholes are generated due to the inherent second phase, the melt is deoxidized by adding Si, Mg, P, etc. to form an oxide. It is effective to suppress the formation of sulfide by addition of Mn.

  In the present embodiment, a copper foil having a thickness of 12 μm or less is particularly targeted, but it can be applied to a copper foil having a thickness of 12 μm or more.

Specific examples of the present invention will be described below.
The results of the examples are shown in Tables 2 to 6 below.
Table 2 shows evaluation results of Cu- (Cr, Zr) -based examples, Table 3 shows evaluation results of Cu-Ag-based examples, and Table 4 shows evaluation results of Cu-Sn-based examples. The evaluation results of the Cu—Ni—Si based examples are shown in Table 5 and the evaluation results of the pure copper based examples are shown in Table 6.
In Tables 2 to 6, the evaluation results of the examples of the copper alloys (1) to (5) are shown in comparison with the reference examples and the comparative examples.
Before describing the results evaluation of the examples in Table 2 to Table 6, the manufacturing method of the rolled copper foil of this embodiment and the comparative example, the evaluation method of the rolled copper foil before rough plating, the battery evaluation method, etc. will be described. To do.

[Method for producing rolled copper foil]
[Process A]
The Example of the manufacturing method of the rolled copper foil which concerns on this embodiment is demonstrated with reference to FIG.
In the first step ST1, the raw material was melted in a high-frequency melting furnace, and the melted raw material was cast in the second step ST2 at a cooling rate of 0.1 to 100 ° C./second to obtain an ingot. The ingot contains the alloy components shown in Tables 2 to 6, and the remainder is formed of Cu and inevitable impurities.

In the third step ST3, the ingot obtained in the second step ST2 was subjected to homogenization heat treatment at a temperature of 800 to 1030 ° C. for 5 minutes to 10 hours, and then subjected to high temperature rolling in the fourth step ST4.
In the fourth step ST4, first high-temperature rolling is performed at a temperature of 670 to 1030 ° C. and a processing rate of 50 to 80%. Next, in a fifth step ST5, cooling is performed by air cooling to 300 to 650 ° C. or less. In step ST6, the second high-temperature rolling of 30 to 60% was performed at a temperature of 300 to 650 ° C.
Next, water cooling was performed in the seventh step ST7, and chamfering was performed in order to remove the oxide scale in the eighth step ST8.

Thereafter, in the ninth step ST9, the intermediate cold rolling is performed at a sheet thickness reduction rate of 66 to 99%, and in the tenth step ST10, the final recrystallization annealing is performed at 300 to 800 ° C. for 3 seconds to 10 hours. In the eleventh step ST11, final cold rolling was performed to produce a rolled foil having a thickness of 12 μm or less.
After each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface, and correction with a tension leveler was performed according to the shape.
An example of the manufacturing method according to the present embodiment is referred to as [Step A].

  In addition, the comparative example in Table 2-Table 6 was manufactured by either of following process EI shown in FIG.

[Step E]
Step E is an intermediate annealing that is held at a temperature of 300 to 800 ° C. for 3 seconds to 10 hours between the first intermediate cold rolling in the ninth step ST9 and the final recrystallization annealing in the tenth step ST10, 66 to 99% The second intermediate cold rolling was carried out at the processing rate of, and the others were in accordance with step A.

[Step F]
In the process F, the cooling in the fifth process ST5 and the second high-temperature rolling in the sixth process ST6 in the process A were not performed, and the others were in accordance with the process A.

[Step G]
In step G, the cooling in the fifth step ST5 and the second high-temperature rolling in the sixth step ST6 in the step A are not performed, but the second intermediate cold rolling in the ninth step ST9 and the final recrystallization in the tenth step ST10. During annealing, intermediate annealing held at a temperature of 300 to 800 ° C. for 3 seconds to 10 hours, second intermediate cold rolling with a processing rate of 66 to 99% was performed, and the others were in accordance with Step A.

[Step H] (Construction method described in JP 2000-328159 A)
Process H is melted in the atmosphere under a charcoal coating in an electric furnace, melts an ingot of 50 mm × 80 mm × 180 mm, hot-rolls it into a slab having a thickness of 15 mm, and further heats at 820 ° C. It was cold-rolled and finished with a plate material having a thickness of 3.3 mm, followed by water cooling.
About these plate materials, after cold rolling to a thickness of 1.2 mm, intermediate annealing at a furnace temperature of 750 ° C. × 20 S, cold rolling to a thickness of 0.4 mm, and then intermediate annealing at a furnace temperature of 700 ° C. × 20 S Then, after cold rolling to a thickness of 0.2 mm, intermediate annealing at a furnace temperature of 650 ° C. × 20 S was performed, and further cold rolling was performed to produce a copper alloy foil having a thickness of 10 μm.
This process H is disclosed by patent document 7 (Unexamined-Japanese-Patent No. 2000-328159).

[Step I] (Construction method described in JP-A-11-310864)
In step I, the ingot is hot-rolled at a finish temperature of 500 ° C. after the soaking process, and then the conditions of each step of cold rolling and final annealing governing the crystal orientation of the copper foil are determined according to the conditions before the final annealing. The rolling rate was 10 to 95%, the final annealing temperature was 400 ° C or higher, and the cold rolling rate after the final annealing was 10 to 99%.
This step I is disclosed in Patent Document 8 (Japanese Patent Laid-Open No. 11-310864).

  In addition, trial manufacture under the conditions disclosed in Patent Document 3 (Japanese Patent Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Laid-Open No. 55-055454) was also performed for comparison.

  The following evaluation was performed about this rolled copper foil before roughening plating. The evaluation results are shown in Tables 2 to 6.

[Area ratio [S (111) / S (100)]]
The area ratio [S (111) between the area ratio S (100) of the region in which the (100) plane is oriented in the rolling direction and the area ratio S (111) of the region in which the (111) plane is oriented in the rolling direction. ) / S (100)] was measured from the rolling surface by the EBSD method according to the method described above. If the pattern was not clear due to the thick work-affected layer on the rolled surface, only the outermost layer was dissolved by chemical polishing and measured.
Using the crystal orientation analysis technique using reflected electron Kikuchi line diffraction (Kikuchi pattern) generated when the sample is irradiated with an electron beam in the SEM by the EBSD method described above, for a sample area of 50,000 square μm or more, Scanning was performed with a 0.2 μm step, and the orientation was analyzed.

[Tensile strength (TS), 0.2% yield strength (YS), elongation (EL)]
Tensile strength (TS), 0.2% proof stress (YS), and elongation (EL) were measured by a tensile test in the rolling parallel direction according to JIS Z2241.

[Conductivity (EC)]
The resistivity was calculated by measuring the specific resistance by a four-terminal method in a constant temperature bath maintained at 20 ° C. (± 0.5 ° C.). In addition, the distance between terminals was 100 mm.

Then, the battery was produced by the following method and the characteristic as a battery was evaluated.
[Roughening plating method]
Finely roughened particles were provided on the rolled copper foil surface under the following conditions under the following conditions.
<Plating bath composition>
Cu (as metal): 60-70 g / l
Sulfuric acid: 110-130 g / l
<Plating conditions>
Temperature: 45-55 ° C
Current density: 60 to 70 A / dm ²
Processing time: 0.4 to 2.0 seconds

[Battery Evaluation 1: Carbon-based negative electrode active material]
(I) Positive electrode 90% by weight of LiCoO ₂ powder, 7% by weight of graphite powder and 3% by weight of polyvinylidene fluoride powder were mixed and added to a solution in which N-methylpyrrolidone was dissolved in ethanol. did. After this paste was uniformly applied to the aluminum foil, it was dried in a nitrogen atmosphere to evaporate ethanol, and then roll-rolled to produce a sheet.
After this sheet was cut, an aluminum foil lead terminal was attached to one end thereof by ultrasonic welding to form a positive electrode.

(Ii) Negative electrode 90% by weight of natural graphite powder (average particle size 10 μm) and 10% by weight of polyvinylidene fluoride powder were mixed, and a solution prepared by dissolving N-methylpyrrolidone in ethanol was added and kneaded to prepare a paste. Subsequently, this paste was applied to both surfaces of the rolled copper foil produced in Examples and Comparative Examples. The coated copper foil was dried in a nitrogen atmosphere to evaporate the solvent, and then roll-rolled to form a sheet.
After this sheet was cut, a nickel foil lead was ultrasonically attached to one end of the sheet to form a negative electrode.

(Iii) Battery assembly A polypropylene separator having a thickness of 25 μm is sandwiched between the positive electrode and negative electrode manufactured as described above, and this is accommodated in a battery can plated with nickel on the surface of the mild steel, and the lead terminal of the negative electrode can be Spot welded to the bottom. Next, place the top cover of the insulating material, insert the gasket, connect the positive lead terminal and the aluminum safety valve by ultrasonic welding, and connect the non-aqueous electrolyte consisting of propylene carbonate, diethyl carbonate and ethylene carbonate in the battery can. Then, a lid was attached to the safety valve, and a lithium ion secondary battery having a sealed structure was assembled.

(Iv) Measurement of battery characteristics The battery produced as described above was subjected to a charge / discharge cycle test in which a cycle of charging to 4.2 V at a charging current of 50 mA and discharging to 2.5 V at 50 mA was taken as one cycle. The battery capacities at the time of the first charge are shown in Tables 2 to 6.

[Battery evaluation 2: Silicon-based negative electrode active material]
(I) Positive electrode Using Li ₂ CO ₃ and CoCO ₃ as starting materials, weigh them so that the atomic ratio of Li: Co is 1: 1, mix in a mortar, press this with a mold and pressurize After molding, it was fired in the air at 800 ° C. for 24 hours to obtain a LiCoO ₂ fired body. This was pulverized in a mortar to prepare an average particle size of 20 μm.
90 parts by weight of the obtained LiCoO ₂ powder, 5 parts by weight of artificial graphite powder as a conductive agent, and 5% by weight of polyvinylidene fluoride as a binder were mixed in a 5% by weight N-methylpyrrolidone solution, and a positive electrode mixture A slurry was obtained.
This positive electrode mixture slurry was applied onto an aluminum foil as a current collector, dried and then rolled. The obtained product was cut out to obtain a positive electrode.

(Ii) Negative electrode 8.6% by weight containing 80.2 parts by weight of silicon powder having an average particle size of 3 μm as an active material (purity 99.9%) and 19.8 parts by weight of polyamic acid (binder α1) as a binder Was mixed with an N-methylpyrrolidone solution to prepare a negative electrode mixture slurry.
This negative electrode mixture slurry was applied to the rolled copper foil prepared in Examples and Comparative Examples, dried, and then rolled. This was heat-treated at 400 ° C. for 30 hours in an argon atmosphere and sintered to obtain a negative electrode.

(Iii) Battery assembly As an electrolytic solution, a solution obtained by dissolving 1 mol / liter of LiPF ₆ in an equal volume mixed solvent of ethylene carbonate and diethylene carbonate was prepared. A lithium secondary battery was produced using the positive electrode, the negative electrode, and the electrolytic solution.
The positive electrode and the negative electrode are opposed via a separator.

(Iv) Evaluation of battery characteristics The charge / discharge cycle characteristics of the above batteries were evaluated. Each battery was charged to 4.2 V at a current value of 1 mA at 25 ° C., and then discharged to 2.75 V at a current value of 1 mA. The discharge capacity after 50 cycles was measured as the discharge capacity retention rate with respect to the discharge capacity at the first cycle.

Tables 2 to 6 show the evaluation results.
In the following, as shown in the evaluation results for each table, when the area ratio [S (111) / S (100)] of the area ratio S defined in the embodiment of the present invention satisfies 2 or less, etc., the battery The characteristic in evaluation was favorable. On the other hand, the comparative example manufactured by the manufacturing processes E to I did not satisfy the condition of the area ratio [S (111) / S (100)], and the battery evaluation result was inferior.
In the process of recrystallization after rolling up to the foils of Patent Document 3 (Japanese Patent Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Laid-Open No. S55-054554), deformation or breakage of the foil occurs in the battery manufacturing process. The characteristics could not be evaluated remarkably.
As reference values, the absolute value of S (111) shown in this example is in the range of 22.1% to 44.6%, and the absolute value of S (100) is in the range of 11.4% to 39.5%. Met.

  Compared with the pure copper system shown in Table 6, the alloy systems in Tables 2 to 5 showed better battery characteristics.

Table 2 shows the evaluation results of the Cu— (Cr, Zr) -based copper alloy.
In the examples in Table 2, Examples 1-1 to 1-8, Reference Example 1-11, and Comparative Examples 1-21 to 1 manufactured by Manufacturing Process A as rolled copper foils (this example) according to the present embodiment. Evaluation was made for -25.

In Examples 1-1 to 1-8 and Comparative Examples 1-21 to 1-25, only the main component Cr, only the main component Zr, or the total of the main components Cr and Zr is 0.01 to 0.9 mass. %, And when the auxiliary additive components Sn, Zn, Si, Mn, and Mg are contained, the total satisfies the condition of 0.01 to 0.45 mass%.
However, Example 3-6 contains 0.52 mass% of the total amount of auxiliary additive components, and slightly exceeds the condition of 0.01 to 0.45 mass% in total of the auxiliary additive components.
In addition, Examples 1-4 and 1-7 do not contain a secondary additive.
In Reference Example 1-11, the total of the main components Cr and Zr deviates from the condition of 0.01 to 0.9 mass%.

In Examples 1-1 to 1-8, the area ratio [S (111) / S (100)] satisfies the condition of 2 or less.
In Examples 1-1 to 1-8, since the 0.2% proof stress (YS) is 400 MPa or more, which is a condition, it is presumed that the amount of limit elastic deformation is increased.

  In Examples 1-1 to 1-8, as can be seen from the values of the initial charge capacity as the battery evaluation 1 and the maintenance factor as the battery evaluation 2, the characteristics in the battery evaluation were good.

  In addition, although Examples 1-4, 1-6, and 1-7 are out of the range where the sub-addition components are 0.01 to 0.45 mass% in total, the characteristics in battery evaluation are good. The result is obtained. This is presumed that whether or not the content of the main component is within the range defined in the present embodiment greatly affects the electrical characteristics.

As described above, Reference Example 1-11 does not satisfy the condition of containing 0.93 mass% of Cr among the main components Cr and Zr, and the total of the main components is 0.01 to 0.9 mass%.
In Reference Example 1-11, production was stopped due to a large number of pinholes.
From the results of Reference Example 1-11, it is presumed that whether or not the content of the main component is within the range defined in the present embodiment greatly affects the electrical characteristics.

In Comparative Example 1-21, the area ratio [S (111) / S (100)] is 2.85 and does not satisfy the condition of 2 or less.
In Comparative Example 1-21, the initial charge capacity as battery evaluation 1 is as low as 341 mAh compared to 478 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 is also 38% of Example 1-1. It is 18% of less than half.
As described above, Comparative Example 1-21 is inferior to Examples in characteristics in battery evaluation.

This is not the manufacturing process A, but the intermediate annealing that is held for 3 seconds to 10 hours at a temperature of 300 to 800 ° C. between the first intermediate cold rolling in the ninth process and the final recrystallization annealing in the tenth process, 66 It is guessed that it originates in having manufactured by the manufacturing process E which performs the 2nd intermediate cold rolling of a process rate of -99%.
That is, the hot rolling, which is a feature of this manufacturing method, is performed between the first high-temperature rolling at the first heating temperature and the second high-temperature rolling at the second heating temperature lower than the first heating temperature with the cooling period interposed therebetween. Even if pressure is applied as the two steps, the area ratio [S (111) / S (100)] is 2 or less when the intermediate annealing step and the second intermediate cold rolling step are performed in addition to each step of the manufacturing step A. This condition is not satisfied, and it is presumed that the battery characteristics are low.

In Comparative Example 1-22, the area ratio [S (111) / S (100)] is 2.32 and does not satisfy the condition of 2 or less.
In Comparative Example 1-22, the initial charge capacity as battery evaluation 1 is as low as 383 mAh compared to 478 mAh in Example 1-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 1-1. It is 15% which is less than half of 38%.
Thus, Comparative Example 1-22 is inferior to the Examples in the battery evaluation.

This is a feature of the present production method (step A). The hot rolling is cooled after the first high temperature rolling at the first heating temperature is performed, and then the second heating temperature is lower than the first heating temperature. It is inferred that this is caused by not performing the second high temperature rolling.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

In Comparative Example 1-23, the area ratio [S (111) / S (100)] is 2.41 and does not satisfy the condition of 2 or less.
In Comparative Example 1-23, the initial charge capacity as battery evaluation 1 is as low as 370 mAh compared to 478 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 is also 38% of Example 1-1. It is 18% of less than half.
Thus, Comparative Example 1-23 is inferior to this example in the battery evaluation characteristics.

This is not the manufacturing process A, but is a feature of the present manufacturing method (process A). After performing the first high-temperature rolling at the first heating temperature, the hot rolling is cooled to be lower than the first heating temperature. Intermediate annealing without performing the second high temperature rolling at the second heating temperature and holding at a temperature of 300 to 800 ° C. for 3 seconds to 10 hours during the final recrystallization annealing with the first intermediate cold rolling, 66 It is guessed that it originates in having manufactured by the manufacturing process G which performs 2nd intermediate cold rolling of a process rate of -99%.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 When the intermediate annealing process and the second intermediate cold rolling process that are not in the manufacturing process A are performed without performing the high temperature rolling, the area ratio [S (111) / S (100)] may satisfy the condition of 2 or less. It is assumed that the battery characteristics are low as a result.

In Comparative Example 1-24, the area ratio [S (111) / S (100)] is 2.51 and does not satisfy the condition of 2 or less.
In Comparative Example 1-24, the initial charge capacity as battery evaluation 1 is as low as 360 mAh compared to 478 mAh in Example 1-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 1-1. That is 19%, half of 38%.
Thus, Comparative Example 1-24 is inferior to this example in battery evaluation characteristics.

This is not the manufacturing process A, but is a feature of the present manufacturing method (process A). After performing the first high-temperature rolling at the first heating temperature, the hot rolling is cooled to be lower than the first heating temperature. It is surmised that the second high-temperature rolling at the second heating temperature is not performed and the manufacturing process H is performed by two intermediate annealings in which cold rolling is sandwiched.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 If high-temperature rolling is not performed and two intermediate annealing steps that are not included in the manufacturing process A are performed, the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less. It is inferred that the characteristics are low.

In Comparative Example 1-25, the area ratio [S (111) / S (100)] is 2.95, which does not satisfy the condition of 2 or less.
In Comparative Example 1-25, the initial charge capacity as Battery Evaluation 1 is as low as 360 mAh compared to 478 mAh in Example 1-1 of this example, and the maintenance rate as Battery Evaluation 2 is also Example 1-1. It is 23% lower than 38%.
Thus, Comparative Example 1-25 is inferior to the Examples in the battery evaluation characteristics.

This is a feature of the present production method (step A). The hot rolling is cooled after the first high temperature rolling at the first heating temperature is performed, and then the second heating temperature is lower than the first heating temperature. It is inferred that this is caused by not performing the second high temperature rolling.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

Table 3 shows the evaluation results of the Cu-Ag copper alloy.
Evaluation was performed on Examples 2-1 to 2-4, Reference Example 2-11, and Comparative Examples 2-21 to 2-23 manufactured by Manufacturing Process A as rolled copper foils (this example) according to the present embodiment. .

Examples 2-1 to 2-4 and Comparative Examples 2-21 to 2-23 satisfy the condition that the total of the main component Ag is contained in an amount of 0.01 to 0.9 mass%. When Si, Mn and Mg are contained, the total satisfies the condition of 0.01 to 0.45 mass%.
However, Reference Example 2-11 does not satisfy the condition that the total amount of the main component Ag is 0.01 to 0.9 mass%.

In Examples 2-1 to 2-4, the area ratio [S (111) / S (100)] satisfies the condition of 2 or less.
In Examples 2-1 to 2-4, the 0.2% proof stress (YS) is 400 MPa or more, which is four conditions, and thus it is surmised that the amount of limit elastic deformation is increased.

  And Examples 2-1 to 2-4 had good characteristics in battery evaluation, as can be seen from the values of the initial charge capacity as battery evaluation 1 and the maintenance factor as battery evaluation 2.

As described above, Reference Example 2-11 contains 0.95 mass% of the main component Ag, and the total of the main components does not satisfy the condition of 0.01 to 0.9 mass%.
In Reference Example 2-11, production was stopped due to a large number of pinholes.
From the results of Reference Example 2-11, it is presumed that the electrical characteristics are greatly influenced by whether or not the content of the main component is within the range defined in the present embodiment.

In Comparative Example 2-21, the area ratio [S (111) / S (100)] is 2.66 and does not satisfy the condition of 2 or less.
In Comparative Example 2-21, the initial charge capacity as battery evaluation 1 is 353 mAh lower than 430 mAh in Example 2-2 of this example, and the maintenance rate as battery evaluation 2 is also in Example 2-2. 17%, almost half of 33%.
Thus, Comparative Example 2-21 has inferior characteristics in battery evaluation as compared with Examples.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 When the intermediate annealing process and the second intermediate cold rolling process that are not in the manufacturing process A are performed without performing the high temperature rolling, the area ratio [S (111) / S (100)] may satisfy the condition of 2 or less. It is assumed that the battery characteristics are low as a result.

In Comparative Example 2-22, the area ratio [S (111) / S (100)] was 2.7, and the condition of 2 or less was not satisfied.
In Comparative Example 2-22, the initial charge capacity as battery evaluation 1 is as low as 359 mAh compared to 430 mAh in Example 2-2 of this example, and the maintenance rate as battery evaluation 2 is also in Example 2-2. It is 15% which is less than half of 33%.
Thus, Comparative Example 2-22 is inferior to Examples in characteristics in battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 If high-temperature rolling is not performed and two intermediate annealing steps that are not included in the manufacturing process A are performed, the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less. It is inferred that the characteristics are low.

In Comparative Example 2-23, the area ratio [S (111) / S (100)] is 2.3 and does not satisfy the condition of 2 or less.
In Comparative Example 2-23, the initial charge capacity as battery evaluation 1 is as low as 353 mAh compared to 430 mAh in Example 2-2 of this example, and the maintenance rate as battery evaluation 2 is also in Example 2-2. 13% which is less than half of 33%.
Thus, Comparative Example 2-23 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as that of Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

Table 4 shows the evaluation results of the Cu—Sn based copper alloy.
In Table 4, about Examples 3-1 to 3-6, Reference Example 3-11, and Comparative Examples 3-21 to 3-23 manufactured by Manufacturing Process A as rolled copper foil (this example) according to the present embodiment Evaluation was performed.

In Examples 3-1 to 3-6 and Comparative Examples 3-21 to 3-23, the total amount of the main component Sn satisfies the condition of 0.01 to 4.9 mass%, and the auxiliary additive components Zn, Si, P When Mg is contained, the total satisfies the condition of 0.01 to 0.45 mass%.
However, Reference Example 3-11 does not satisfy the condition that the total amount of the main component Sn is 0.01 to 4.9 mass%.

In Examples 3-1 to 3-6, the area ratio [S (111) / S (100)] satisfies the condition of 2 or less.
In Examples 3-1 to 3-6, since the 0.2% yield strength (YS) is 400 MPa or more, which is a condition, it is presumed that the amount of limit elastic deformation is increased.

  In Examples 3-1 to 3-6, as can be seen from the values of the initial charge capacity as the battery evaluation 1 and the maintenance factor as the battery evaluation 2, the characteristics in the battery evaluation were good.

As described above, Reference Example 3-11 contains 5.12 mass% of the main component Sn, and does not satisfy the condition of 0.01 to 4.9 mass% of the main component.
Reference Example 3-11 was discontinued due to the large number of pinholes.
From the results of Reference Example 3-11, it is presumed that the electrical characteristics are greatly influenced by whether or not the content of the main component is within the range defined in the present embodiment.

In Comparative Example 3-21, the area ratio [S (111) / S (100)] is 2.15, which does not satisfy the condition of 2 or less.
In Comparative Example 3-21, the initial charge capacity as battery evaluation 1 is as low as 373 mAh compared to 439 mAh in Example 3-1 of this example, and the maintenance rate as battery evaluation 2 is also the example of this example. It is 17%, almost half of 33% of 3-1.
Thus, Comparative Example 3-21 is inferior to this example in battery evaluation characteristics.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 When the intermediate annealing process and the second intermediate cold rolling process that are not in the manufacturing process A are performed without performing the high temperature rolling, the area ratio [S (111) / S (100)] may satisfy the condition of 2 or less. It is assumed that the battery characteristics are low as a result.

In Comparative Example 3-22, the area ratio [S (111) / S (100)] is 2.33 and does not satisfy the condition of 2 or less.
In Comparative Example 3-22, the initial charge capacity as battery evaluation 1 is as low as 373 mAh compared to 439 mAh in Example 3-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 3-1. It is 15% which is less than half of 33%.
Thus, Comparative Example 3-22 has inferior characteristics in battery evaluation to the Examples.

This is presumed to be the same reason as for Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 If high-temperature rolling is not performed and two intermediate annealing steps that are not included in the manufacturing process A are performed, the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less. It is inferred that the characteristics are low.

In Comparative Example 3-23, the area ratio [S (111) / S (100)] was 2.82, which did not satisfy the condition of 2 or less.
In Comparative Example 3-23, the initial charge capacity as battery evaluation 1 is as low as 339 mAh compared to 439 mAh in Example 3-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 3-1. 13% which is less than half of 33%.
Thus, Comparative Example 3-23 is inferior to Examples in characteristics in battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

Table 5 shows the evaluation results of the Cu—Ni—Si based copper alloy.
In the Example of Table 5, Examples 4-1 to 4-8 manufactured by the manufacturing process A as the rolled copper foil (this example) according to the present embodiment, Reference Example 4-11 manufactured by the manufacturing process A, Evaluation was performed on Comparative Examples 4-21 to 4-23 manufactured in the manufacturing processes G, F, and I.

Examples 4-1 to 4-8 and Comparative Examples 4-21 to 4-23 satisfy the condition of containing 1.4 to 4.8 mass% of the main component Ni, and 0.2 to 1. of the main component Si. The condition of containing 3 mass% is satisfied, and the total of the sub-addition components Sn, Zn, Si, Cr, Mn, Mg, Co is satisfied from 0.005 to 0.9 mass%.
However, Reference Example 4-11 does not satisfy the condition of containing 1.4 to 4.8 mass% of the main component Ni.

In Examples 4-1 to 4-8, the area ratio [S (111) / S (100)] satisfies the condition of 2 or less.
In Examples 4-1 to 4-8, since the 0.2% yield strength (YS) is 400 MPa or more, which is a condition, it is surmised that the amount of limit elastic deformation is increased.

  And Examples 4-1 to 4-8 had good characteristics in battery evaluation, as can be seen from the values of the initial charge capacity as battery evaluation 1 and the maintenance factor as battery evaluation 2.

Reference Example 4-11 contains 4.92 mass% of Ni among the main components Ni and Si and does not satisfy the condition of 1.4 to 4.8 mass% of the main component Ni.
Reference Example 4-11 was discontinued due to the large number of pinholes.
From the results of Reference Example 4-11, it is presumed that the electrical characteristics are greatly influenced by whether or not the content of the main component is within the range defined in the present embodiment.

In Comparative Example 4-21, the area ratio [S (111) / S (100)] is 2.25, which does not satisfy the condition of 2 or less.
In Comparative Example 4-21, the initial charge capacity as battery evaluation 1 is as low as 379 mAh compared to 439 mAh in Example 4-1 of this example, and the maintenance rate as battery evaluation 2 is also Example 4-1 It is 16% which is less than half of 34%.
Thus, Comparative Example 4-21 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 When the intermediate annealing process and the second intermediate cold rolling process that are not in the manufacturing process A are performed without performing the high temperature rolling, the area ratio [S (111) / S (100)] may satisfy the condition of 2 or less. It is assumed that the battery characteristics are low as a result.

In Comparative Example 4-22, the area ratio [S (111) / S (100)] is 2.46, which does not satisfy the condition of 2 or less.
In Comparative Example 4-22, the initial charge capacity as the battery evaluation 1 is as low as 349 mAh compared to 439 mAh in the Example 4-1, and the maintenance rate as the battery evaluation 2 is also 34% of the Example 4-1. It is 15% of less than half.
Thus, Comparative Example 4-22 is inferior to this example in terms of battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-22 manufactured in Manufacturing Process F shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

In Comparative Example 4-23, the area ratio [S (111) / S (100)] is 2.78 and does not satisfy the condition of 2 or less.
In Comparative Example 4-23, the initial charge capacity as battery evaluation 1 is as low as 325 mAh compared to 439 mAh in Example 4-1, and the maintenance rate as battery evaluation 2 is also 34% of Example 4-1. 13%, which is less than half.
Thus, Comparative Example 4-23 is inferior to Examples in characteristics in battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

Table 6 shows the pure copper-based evaluation results.
In the Example of Table 6, it manufactures with Examples 5-1 to 5-2 manufactured by the manufacturing process A as a rolled copper foil (this example) which concerns on this embodiment, and the manufacturing processes E, F, G, H, and I. The comparative examples 5-21 to 5-25 were evaluated.

In Example 5-1 and Comparative Examples 5-21 to 5-25, the oxygen amount was 180 ppm, and the oxygen amount condition of 2 to 200 ppm was satisfied.
In Example 5-2 of this example, the oxygen amount is 6 ppm, and the oxygen amount condition of 2 to 200 ppm is satisfied.

In Examples 5-1 and 5-2, the area ratio [S (111) / S (100)] satisfies the condition of 2 or less.
In Examples 5-1 and 5-2, since the 0.2% proof stress (YS) is 400 MPa or more, which is a condition, it is presumed that the limit elastic deformation amount is increased.

  Examples 5-1 and 5-2 had good battery evaluation characteristics as can be seen from the initial charge capacity as battery evaluation 1 and the maintenance factor value as battery evaluation 2.

In Comparative Example 5-21, the area ratio [S (111) / S (100)] is 2.09 and does not satisfy the condition of 2 or less.
In Comparative Example 5-21, the initial charge capacity as battery evaluation 1 is 383 mAh lower than 448 mAh in Example 5-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 5-1. 11%, which is about 1/3 of 29%.
Thus, Comparative Example 5-21 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-21 manufactured in the manufacturing process E shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of this manufacturing method, is performed between the first high-temperature rolling at the first heating temperature and the second high-temperature rolling at the second heating temperature lower than the first heating temperature with the cooling period interposed therebetween. Even if pressure is applied as the two steps, the area ratio [S (111) / S (100)] is 2 or less when the intermediate annealing step and the second intermediate cold rolling step are performed in addition to each step of the manufacturing step A. This condition is not satisfied, and it is presumed that the battery characteristics are low.

In Comparative Example 5-22, the area ratio [S (111) / S (100)] is 2.44 and does not satisfy the condition of 2 or less.
In Comparative Example 5-22, the initial charge capacity as battery evaluation 1 is 373 mAh lower than 448 mAh in Example 5-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 5-1. It is 10% which is about 1/3 of 29%.
Thus, Comparative Example 5-22 is inferior to the Examples in terms of battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-22 manufactured in Manufacturing Process F shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

In Comparative Example 5-23, the area ratio [S (111) / S (100)] is 2.85 and does not satisfy the condition of 2 or less.
In Comparative Example 5-23, the initial charge capacity as battery evaluation 1 is as low as 353 mAh compared to 448 mAh in Example 5-1, and the maintenance rate as battery evaluation 2 is also 29% of Example 5-1. It is 8% of 1/3 or less.
Thus, Comparative Example 5-23 is inferior to this example in battery evaluation characteristics.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 When the intermediate annealing process and the second intermediate cold rolling process that are not in the manufacturing process A are performed without performing the high temperature rolling, the ratio [S (111) / S (100)] can satisfy the condition of 2 or less. Therefore, it is presumed that the battery characteristics are low.

In Comparative Example 5-24, the area ratio [S (111) / S (100)] is 2.35 and does not satisfy the condition of 2 or less.
In Comparative Example 5-24, the initial charge capacity as battery evaluation 1 is 363 mAh lower than 448 mAh in Example 5-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 5-1. 11%, which is about 1/3 of 29%.
Thus, Comparative Example 5-24 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 If high-temperature rolling is not performed and two intermediate annealing steps that are not included in the manufacturing process A are performed, the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less. It is inferred that the characteristics are low.

In Comparative Example 5-25, the area ratio [S (111) / S (100)] is 2.54 and does not satisfy the condition of 2 or less.
In Comparative Example 5-25, the initial charge capacity as battery evaluation 1 is as low as 368 mAh compared to 448 mAh in Example 5-1 of this example, and the maintenance rate as battery evaluation 2 is also in Example 5-1. It is 8% which is 1/3 or less from 29%.
Thus, Comparative Example 5-25 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling at the first heating temperature and then cooled to the second temperature at the second heating temperature lower than the first heating temperature. 2 Since high temperature rolling is not performed, it is presumed that the area ratio [S (111) / S (100)] cannot satisfy the condition of 2 or less, and the battery characteristics are lowered.

As described above, when the area ratio [S (111) / S (100)] of the area ratio defined in the embodiment of the present invention satisfies 2 or less, the characteristics in battery evaluation were good. .
Moreover, after performing the 1st high temperature rolling of the 1st heating temperature which is the manufacturing method (manufacturing process A) of the rolled copper foil which concerns on this embodiment, it cools and is lower than 1st heating temperature By performing the second high temperature rolling at the second heating temperature and not performing the intermediate annealing step or the like not in the manufacturing step A, the area ratio [S (111) / S (100)] and the like are satisfied, and the battery evaluation The characteristics in were good.

On the other hand, the comparative example manufactured by the manufacturing steps E to I did not satisfy the condition that the area ratio [S (111) / S (100)] was 2 or less, and the battery evaluation result was inferior.
In the process of recrystallization after rolling up to the foils of Patent Document 3 (Japanese Patent Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Laid-Open No. S55-054554), deformation or breakage of the foil occurs in the battery manufacturing process. The characteristics could not be evaluated remarkably.
Moreover, it can be said that the alloy system of Table 2-Table 5 shows a favorable battery characteristic with respect to the pure copper system shown in Table 6.

  According to this embodiment, since the amount of critical elastic deformation is large, plastic deformation is difficult, and the yield of the manufacturing process of the battery and the cycle characteristics of charging and discharging of the battery can be improved.

  The present invention is not limited to the alloys shown in the present embodiment, but includes Cu-Fe, Cu-Ti, Cu-Be, Cu-Zn, Cu-Ni, and Cu-Al. It can be applied to all types of copper alloys.

  The present invention can be applied not only to the above-mentioned carbon-based and silicon (Si) -based negative electrode active materials, but also to negative electrode current collectors for batteries made of various active materials such as tin (Sn) -based materials and composite materials thereof. However, the effects of the present invention are not limited to the structure of the battery shown in this embodiment.

  The rolled copper foil of the embodiment of the present invention can also be used for a flexible substrate (FPC), a tape carrier package (TCP, TAB), and a chip-on-flex (COF).

DESCRIPTION OF SYMBOLS 10 ... Secondary battery 11 ... Positive electrode 12 ... Negative electrode 13 ... Positive electrode collector 14 ... Negative electrode collector 15 ... Separator 16 ... Positive electrode side battery can 17 ... Negative side battery can 18 ... Insulation packing 20 ... Rolled copper foil

An object of the present invention is to provide a rolled copper for a secondary battery negative electrode current collector that is difficult to be plastically deformed due to a large amount of critical elastic deformation, and that can improve the yield of a manufacturing process of a battery and the electrical characteristics of a product. It is to provide a foil and a manufacturing method thereof.

According to the present invention, a rolled copper foil for a secondary battery negative electrode current collector made of copper or a copper alloy formed by rolling, and an area ratio S (111) of a region in which the (111) plane faces in the rolling direction with respect to the crystal orientation. ) And the area ratio S (100) of the region facing the (100) plane in the rolling direction [S (111) / S (100)] is 2 or less, for a secondary battery negative electrode current collector A rolled copper foil is provided.
Here, the area ratio is calculated by dividing (dividing) the area of the region whose deviation angle is within 15 ° from the ideal orientation by the total measurement area.
Moreover, although rolled copper foil may mean the rolled copper foil of pure copper, in this invention, it means the rolled copper foil of a copper alloy widely.

Moreover, according to this invention, it is a manufacturing method of the rolled copper foil which manufactures the rolled copper foil for secondary battery negative electrode collectors in any one of Claims 1-11, Comprising: The melt | dissolution process which melt | dissolves a raw material, A casting process for casting the melted raw material, a homogenization heat treatment process for subjecting the material to be rolled obtained by casting to a homogenization heat treatment at 300 to 1030 ° C. for 5 minutes to 10 hours, and the homogenization with respect to the material to be rolled which is heat-treated at 670 to 1,030 ° C, a first hot rolling step carried out at 50-80% of working ratio, after the first hot rolling step, the cooling of the material to be rolled and line cormorant cooling step, after as the cold 却工, the relative material to be rolled, with 300 to 650 ° C, a second hot rolling step carried out at 30% to 60% of processing rate, the second hot rolling after the step, a water-cooling step of cooling the material to be rolled, after the water cooling step, before A chamfering process for chamfering the rolled material, an intermediate cold rolling process for cold rolling the rolled material after the chamfering process, and after the intermediate cold rolling process , After the final recrystallization annealing step for performing heat treatment at 300 to 800 ° C. for 3 seconds to 10 hours with respect to the material to be rolled , and after the final recrystallization annealing step, the cold material is finally cold- treated. to chromatic and final cold rolling step of performing rolling, the secondary battery negative electrode current collector production method of the rolled copper foil.

Preferably, in the higher pre Kihiya却工, without processing, for cooling only.

According to the present invention, a rolled copper foil made of copper or a copper alloy formed by rolling,
a. A Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, and a total of at least one of Cr and Zr as main components is 0.01 to 0.9 mass. % Contained, or
b. It is a Cu-Ag based copper alloy containing Ag as a main component, and contains 0.01 to 0.9 mass% of Ag as a main component, or
c. It is a Cu-Sn based copper alloy containing Sn as a main component, and contains 0.01 to 4.9 mass% of Sn as a main component, or
d. It is a pure copper system containing oxygen, and the oxygen amount is 2 to 200 ppm,
The area ratio [S (111) / S] of the area ratio S (111) of the region whose (111) plane faces in the rolling direction with respect to the crystal orientation and the area ratio S (100) of the region whose (100) plane faces in the rolling direction. (100)] is provided, and the rolled copper foil for secondary battery negative electrode collector is provided .
Here, the area ratio is calculated by dividing (dividing) the area of the region whose deviation angle is within 15 ° from the ideal orientation by dividing the entire measurement area.
Moreover, although rolled copper foil may mean the rolled copper foil of pure copper, in this invention, it means the rolled copper foil of a copper alloy widely.

According to the present invention, there is also provided a method for producing a rolled copper foil for producing the rolled copper foil for a secondary battery negative electrode current collector,
A melting step for melting the raw materials;
A casting process for casting the melted raw material;
A homogenized heat treatment step of performing a homogenized heat treatment at 800 to 1030 ° C. for 5 minutes to 10 hours on the material to be rolled obtained by casting,
A first high-temperature rolling step, which is performed at a processing rate of 50 to 80% at 670 to 1030 ° C. with respect to the material to be rolled that has been subjected to the homogenization heat treatment;
A first cooling step for cooling the material to be rolled after the first high-temperature rolling step;
After the first cooling step, a second high temperature rolling step performed at a processing rate of 30 to 60 minutes at 300 to 650 ° C. with respect to the material to be rolled,
A second cooling step for cooling the material to be rolled after the first high-temperature rolling step;
A chamfering step for chamfering the material to be rolled after the second cooling step;
After the chamfering step, a final recrystallization annealing step of performing heat treatment at 300 to 800 ° C. for 3 seconds to 10 hours with respect to the material to be rolled,
There is provided a method for producing a rolled copper foil for a secondary battery negative electrode current collector , comprising a final cold rolling step of performing final cold rolling on the material to be rolled after the final recrystallization annealing step.

A rolled copper foil made of copper or a copper alloy formed by rolling of the present invention,
a. A Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, wherein at least one of Cr and Zr as the main component is 0.01 to 0.00 in total. Containing 9 mass%, the balance excluding the main component is made of Cu and inevitable impurities, or
b. A Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, wherein at least one of Cr and Zr as the main component is 0.01 to 0.00 in total. 9 mass% contained , 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg as sub-additive components, with the remainder excluding the main component and the sub-addition components being inevitable impurities It consists of, or,
c. A Cu-Ag based copper alloy containing Ag as a main component, a Ag serving as the main component contains 0.01～0.9Mass% in total, the balance excluding the main component being Cu and unavoidable impurities , or,
d. A Cu-Ag based copper alloy containing Ag as a main component, containing 0.01 to 0.9 mass% of Ag as the main component in total, and Sn, Zn, Si, Mn, Mg as sub-addition components containing 0.01～0.45Mass% of at least one total from the balance excluding the main component and the sub-additive component comprises unavoidable impurities, or,
e. A Cu-Sn based copper alloy containing Sn as a main component, a Sn serving as the main component contains 0.01～4.9Mass% in total, the balance excluding the main component being Cu and unavoidable impurities , or,
f. A Cu—Sn based copper alloy containing Sn as a main component, containing 0.01 to 4.9 mass% of Sn as the main component, and at least from Zn, Si, P, and Mg as sub-addition components 1 type is contained in total in a range of 0.01 to 0.45 mass%, and the balance excluding the main component and the auxiliary additive component consists of inevitable impurities, or
g. A pure copper including oxygen, oxygen content Ri 2~200ppm der, and the balance of Cu and inevitable impurities,
The area ratio [S (111) / S] of the area ratio S (111) of the region whose (111) plane faces in the rolling direction with respect to the crystal orientation and the area ratio S (100) of the region whose (100) plane faces in the rolling direction. (100)] is a rolled copper foil for secondary battery negative electrode current collector, which is 2 or less.
Here, the area ratio is calculated by dividing (dividing) the area of the region whose deviation angle is within 15 ° from the ideal orientation by dividing the entire measurement area.
Moreover, although rolled copper foil may mean the rolled copper foil of pure copper, in this invention, it means the rolled copper foil of a copper alloy widely.

Claims (13)

A rolled copper foil made of copper or a copper alloy formed by rolling,
The area ratio [S (111) / S] of the area ratio S (111) of the region whose (111) plane faces in the rolling direction with respect to the crystal orientation and the area ratio S (100) of the region whose (100) plane faces in the rolling direction. (100)] is 2 or less. The rolled copper foil for a secondary battery current collector. A Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, and a total of at least one of Cr and Zr as main components is 0.01 to 0.9 mass. The rolled copper foil for a secondary battery current collector according to claim 1. The rolled copper foil for a secondary battery current collector according to claim 2, containing a total of 0.01 to 0.45 mass% of Sn, Zn, Si, Mn, and Mg as auxiliary additives. The rolled copper foil for a secondary battery current collector according to claim 1, wherein the copper alloy is a Cu-Ag-based copper alloy containing Ag as a main component, and contains 0.01 to 0.9 mass% of Ag as a main component. . The rolled copper foil for a secondary battery current collector according to claim 4, comprising 0.01 to 0.45 mass% in total of at least one of Sn, Zn, Si, Mn, and Mg serving as auxiliary additives. The rolled copper foil for a secondary battery current collector according to claim 1, which is a Cu-Sn based copper alloy containing Sn as a main component, and contains 0.01 to 4.9 mass% of Sn as a main component in total. . The rolled copper foil for a secondary battery current collector according to claim 6, comprising at least one of Zn, Si, P, and Mg as auxiliary additives in a total amount of 0.01 to 0.45 mass%. A Cu-Ni-Si based copper alloy containing Ni and Si as main components, comprising 1.4 to 4.8 mass% of Ni as a main component and 0.2 to 1.3 mass% of Si. 1. A rolled copper foil for a secondary battery current collector according to 1. The rolled copper foil for a secondary battery current collector according to claim 8, comprising at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co, which are auxiliary additives, in a total amount of 0.005 to 0.9 mass%. . The rolled copper foil for a secondary battery current collector according to claim 1, which is a pure copper system containing oxygen and has an oxygen amount of 2 to 200 ppm. The rolled copper foil for a secondary battery current collector according to any one of claims 2 to 10, wherein the remainder excluding the main component or the remainder excluding the main component and the auxiliary additive component is formed by inevitable impurities. A method for producing a rolled copper foil for producing a rolled copper foil for a secondary battery current collector according to any one of claims 1 to 11,
A homogenization heat treatment step of performing a homogenization heat treatment on the forged material to be rolled;
A hot rolling process in which a plurality of high-temperature rolling is performed across the cooling process for the material to be rolled that has been subjected to homogenization heat treatment,
A first cooling step for performing post-cooling in the hot rolling step;
A chamfering step for chamfering after the second cooling step;
An intermediate cold rolling step of performing intermediate cold rolling at a predetermined sheet thickness reduction rate after the chamfering step;
After the intermediate cold rolling, a final recrystallization annealing step for performing a final recrystallization annealing at a predetermined temperature for a predetermined time;
A final cold rolling step of performing a final cold rolling after the final recrystallization annealing,
The hot rolling step,
A first high temperature rolling step of performing a first high temperature rolling at a first heating temperature equal to or higher than a recrystallization temperature;
A second cooling step of cooling after performing the first high temperature rolling;
A second high-temperature rolling step of performing a second high-temperature rolling at a second heating temperature lower than the first heating temperature after the second cooling step, and a method for producing a rolled copper foil for a secondary battery current collector. The method for producing a rolled copper foil for a secondary battery current collector according to claim 12, wherein the second cooling step performs only cooling without performing processing.

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