TW201316589A - Rolled copper foil for secondary battery collector and production method therefor - Google Patents

Abstract

Provided are: a rolled copper foil having a wide area wherein striated irregularities are formed and having excellent uniformity of roughening plating; and a production method therefor. The rolled copper foil (20) comprises copper or copper alloy formed by rolling, and the area ratio within 13 DEG of the RDW orientation {012} <100> is no more than 15% in the crystal orientation of the surface.

Description

Rolled copper foil for secondary battery current collector and manufacturing method thereof

The present invention relates to a rolled copper foil which can be applied to a current collector for a secondary battery, and a method for producing the same, and more particularly to a roughening plating property which can be improved for the purpose of increasing adhesion to an active material. Rolled copper foil, and a method of manufacturing the same.

The rolled copper foil can be applied to a negative electrode current collector of a secondary battery such as a lithium ion battery, and is usually coated with an active material.

Therefore, when the adhesion between the current collector and the active material is poor, various problems occur. For example, the active material is detached due to external stress in the battery process. Further, the expansion and contraction of the active material caused by charge and discharge during use of the battery cause peeling between the current collector and the active material.

Therefore, the surface of the rolled copper foil is roughened by wet plating, and a surface having large irregularities is actively formed to improve the adhesion between the current collector and the active material.

Since the unevenness uniformity of the surface after the roughening treatment is secured by the unevenness of the surface of the rolled copper foil, the control of the surface unevenness during the production of the rolled copper foil for a battery is an important technical issue that is closely related to the battery characteristics.

In recent years, due to the further demand for battery capacity, the separation of active materials is the main cause of capacity reduction. Further, since the active material is expected to use an active material such as cerium (Si) or tin (Sn) which is so-called expanded and contracted, this problem is particularly important.

Usually, stripe-like irregularities in the rolling direction of 60 to 120 are formed on the surface after rolling. However, a strip-shaped, non-concavo-convex region having a size of 10 μm (μm) formed in the width direction with respect to the rolling direction and having a size of 100 μm (μm) in the longitudinal direction causes a problem.

When the surface of the rolled copper foil contains a large amount of the region which is small and coarse with respect to the surrounding unevenness, when the roughening plating is applied thereto, a roughened surface having a large variation of the uneven portion is formed. A problem that causes some of the active material to peel off occurs.

Several methods have been proposed for controlling the unevenness of the surface of the rolled copper foil (for example, refer to Patent Documents 1 to 3).

Patent Document 1 proposes a method of improving the average interval of unevenness by optimizing the rolling conditions, and Patent Document 2 proposes a method of reducing the average interval of the unevenness.

Patent Document 3 discloses an optimum range of the average interval S between the surface roughness Ra and the local peaks.

Conventional technical literature

Patent literature

Patent Document 1: Japanese Patent Laid-Open Publication No. 2006-281249

Patent Document 2: Japanese Patent Laid-Open Publication No. 2007-268596

Patent Document 3: World Patent Publication No. WO 2001/029912

In the above patent documents, only the interval of the primary concavities and convexities in a certain direction is Controlled by indicators, there is no area control. In addition, gloss, surface roughness Ra, Rz, etc. are average indicators of a wide range of measurement, and there is no control over the heterogeneity.

Further, in Patent Documents 1 and 2, the control method is an optimum rolling condition, and the unevenness cannot be effectively eliminated. Therefore, it is often impossible to meet the 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 having a wide range of strip-shaped irregularities and having excellent roughening plating uniformity, and a method for producing the same.

The present inventors have actively studied the influence of the crystal orientation on the unevenness of the formation of the strip-like irregularities at each position. Then, the inventors have found that the crystal orientation of the unformed strip-shaped concavo-convex region is mainly {012}<100>, and by reducing the position of the copper foil to the surface, the surface irregularities can be uniformized. The present invention has been proposed in view of good adhesion to an active material.

In addition, the RDW position in the rolled copper foil is greatly affected by the final annealed structure in the process, and thus the process steps for controlling the influence are invented.

The invention provides a rolled copper foil which is a rolled copper foil composed of copper or a copper alloy formed by calendering, comprising: in the surface crystal orientation direction, the RDW position is within 13° of the {012}<100> direction The area ratio is 15% or less.

Further, the rolled copper foil is also referred to as a rolled foil of pure copper, but in this case, it is generally referred to as a rolled foil of a copper alloy.

The area of the area where the stripe pattern of the strip pattern in the direction of 60° to 120° in the rolling direction is found is preferably 60% or more.

The rolled copper foil preferably comprises a Cu-(Cr, Zr)-based copper alloy having a main component of at least one of Cr and Zr, and a total content of at least one of Cr and Zr as a main component is 0.01 to 0.9% by weight.

Further, the Cu-(Cr, Zr)-based rolled copper foil preferably includes a sub-addition component having a total content of at least one of Sn, Zn, Si, Mn, and Mg of 0.01 to 0.45 wt%.

Further, the Cu-(Cr, Zr)-based rolled copper foil is composed of the remainder except the main component, or the remainder except the main component and the sub-additive component, which are composed of unavoidable impurities.

The rolled copper foil preferably comprises a Cu-Ag-based copper alloy having a main component of Ag, and a total content of Ag of the main component is 0.01 to 0.9% by weight.

The Cu-Ag-based rolled copper foil preferably includes a sub-addition component having a total content of at least one of Sn, Zn, Si, Mn, and Mg of 0.01 to 0.45 wt%.

Further, the remaining portion of the Cu-Ag-based rolled copper foil except for the main component, or the remainder other than the main component and the sub-additive component, is composed of unavoidable impurities.

The rolled copper foil preferably comprises a Cu-Sn-based copper alloy having a main component of Sn, and the total content of Sn of the main component is 0.01 to 4.9% by weight.

The Cu-Sn-based rolled copper foil preferably includes a sub-additive component having a total content of at least one of Zn, Si, P, and Mg of 0.01 to 0.45 wt%.

Moreover, the remaining portion of the Cu-Sn-based rolled copper foil except for the main component, or the remainder except the main component and the sub-additive component, is an unavoidable impurity. Composed of.

The rolled copper foil preferably comprises a Cu-Ni-Si-based copper alloy having a main component of Ni and Si, and has a Ni content of 1.4 to 4.8% by weight and a Si content of 0.2 to 1.3% by weight.

The Cu-Ni-Si-based rolled copper foil preferably includes a sub-additive component having a total content of at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co of 0.005 to 0.9% by weight.

Further, the remaining portion of the Cu-Ni-Si-based rolled copper foil except for the main component, or the remainder other than the main component and the sub-additive component, is composed of unavoidable impurities.

The rolled copper foil preferably comprises a pure copper system of oxygen and has an oxygen content of 2 to 200 ppm.

Moreover, the remainder of the pure copper-based rolled copper foil is composed of unavoidable impurities.

Further, the production method of the present invention is a method for producing a rolled copper foil of a rolled copper foil according to any one of the above-described rolled copper foils, comprising: a heat-calendering step of heating the rolled material to a temperature higher than a recrystallization temperature For performing inter-heat rolling; at least 2 intermediate cold rolling steps, after the hot pressing step, performing cold rolling at a temperature at which no recrystallization occurs; at least one intermediate annealing step, Between intermediate cold rolling steps, cold rolling is performed at a temperature at which no recrystallization occurs; and final annealing step, after the last intermediate cold rolling step, at a specific temperature, and at a specific heating rate To perform the final annealing, in the above intermediate annealing step before the final annealing step, the temperature increasing rate is set to be not given the time for generating the recrystallization precursor phenomenon. The degree of arrival temperature is set to suppress the preferential movement of the specific boundary particle size, and the high temperature of the randomized recrystallized structure can be obtained.

In the above intermediate annealing step before the final annealing step, the above-mentioned reaching temperature is preferably a temperature higher than the recrystallization upper limit temperature of the copper alloy.

In the intermediate annealing step before the final annealing step, the temperature increase rate is preferably 2 ° C /sec or more, and the reaching temperature is preferably 800 ° C or higher.

Preferably, the method for manufacturing a rolled copper foil further comprises: a first intermediate cold rolling step, performing cold rolling after the hot pressing step; and a first intermediate annealing step, performing intermediate annealing after the first intermediate cold rolling step a second intermediate cold rolling step, performing cold rolling after the first intermediate annealing step; a second intermediate annealing step, performing intermediate annealing after the second intermediate cold rolling step; and a third intermediate cold rolling step Performing cold rolling after the second intermediate annealing step, wherein the final annealing step is preferably performed after the third intermediate cold rolling step, and the second intermediate annealing step is preferably performed before the final annealing step. In the intermediate annealing step, the temperature increase rate is preferably set to a rate at which the recrystallization precursor phenomenon is not given, and the arrival temperature is preferably set to suppress the preferential movement of the specific boundary particle diameter, and the high temperature of the randomized recrystallized structure can be obtained.

Preferably, before the intercalation step, a homogenization heat treatment step is further included to perform a homogenization heat treatment on the calendered material.

According to the present invention, it is possible to obtain a rolled copper foil having a wide formation area of strip-like irregularities and excellent roughening plating uniformity, thereby obtaining good adhesion between the current collector and the active material.

As a result, an external force formed in a process such as a battery can make the active material less likely to fall off from the current collector, and the capacity of the secondary battery can be improved. Furthermore, even if the active material such as tin (Sn) and cerium (Si) which are expanded and ‧ contracted during charging and discharging are deformed, not only the active material and the current collector can be prevented from being separated, but also the second can be improved. The secondary battery is charged and discharged.

1 is a schematic view showing a lithium secondary battery using a rolled copper foil as a negative electrode current collector according to an embodiment of the present invention.

Fig. 2 is a schematic enlarged view showing a rolled copper foil according to an embodiment of the present invention.

The lithium secondary battery 10 of 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 package 18.

The positive electrode 11 and the negative electrode 12 are arranged to face each other with the separator 15 interposed therebetween. The positive electrode 11, the negative electrode 12, and the separator 15 are housed in a battery case formed of the positive electrode side battery can 16 and the negative electrode side battery can 17 .

In the storage 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 configuration, the battery 10 can be charged and discharged.

In the present embodiment, the rolled copper foil 20 shown in Fig. 2 is used as the negative electrode current collector 14.

The rolled copper foil 20 of the present embodiment is configured by, for example, setting the thickness d to 12 μm or less.

The area ratio of the region of the rolled copper foil 20 which is found to have a strip-like pattern in the direction of 60° to 120° in the rolling direction is 60% or more.

Further, the area ratio of the RDW position of the rolled copper foil 20 to the center in the {012}<100> direction of the crystal orientation of the surface is 15% or less.

The crystal orientation can be measured, for example, by electron backscatter diffraction (EBSD method).

Further, the rolled copper foil 20 of the present embodiment is formed of a copper alloy or a pure copper system represented by the following (1) to (5).

(1): Cu-(Cr, Zr) copper alloy

The rolled copper foil 20 includes a Cu-(Cr, Zr)-based copper alloy having a main component of at least one of Cr and Zr, and the copper alloy is composed of a total content of at least one of Cr and Zr of the main component of 0.01 to 0.9% by weight. Formed.

In addition, the Cu-(Cr, Zr)-based copper alloy may add a sub-additive component as needed. At this time, the total content of at least one of Sn, Zn, Si, Mn, and Mg in the copper alloy is 0.01-0.45. The weight % is formed.

The remainder of the Cu-(Cr,Zr)-based copper alloy except for the main component, or the remainder except the main component and the sub-additive component, is composed of unavoidable impurities.

(2): Cu-Ag copper alloy

The rolled copper foil 20 includes a Cu-Ag-based copper alloy having a main component of Ag, which is formed by a total content of the main component Ag of 0.01 to 0.9% by weight.

In addition, the Cu-Ag-based copper alloy may be added with a sub-additive component as needed, and the copper alloy is formed by adding a total content of at least one of Sn, Zn, Si, Mn, and Mg of the sub-additive component to 0.01 to 0.45 wt%. .

The remainder of the Cu-Ag-based copper alloy except for the main component, or the remainder except the main component and the sub-additive component, is composed of unavoidable impurities.

(3): Cu-Sn copper alloy

The rolled copper foil 20 includes a Cu-Sn-based copper alloy having a main component of Sn, which is formed by a total content of the main component Sn of 0.01 to 4.9% by weight.

Further, the Cu-Sn-based copper alloy may be added with a sub-additive component as needed, and the copper alloy is formed by a total content of at least one of Zn, Si, P, and Mg of the sub-additive component of 0.01 to 0.45 wt%.

The remainder of the Cu-Sn-based copper alloy except for the main component, or the remainder except the main component and the sub-additive component, is composed of unavoidable impurities.

(4): Cu-Ni-Si copper alloy

The rolled copper foil 20 includes a Cu-Ni-Si-based copper alloy having a main component of Ni and Si, and the copper alloy is formed by a Ni content of the main component of 1.4 to 4.8% by weight and a Si content of 0.2 to 1.3% by weight.

In addition, Cu-Ni-Si copper alloy can be added as needed to add In this case, the copper alloy is formed by a total content of at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co as a by-additive component of 0.005 to 0.9% by weight.

The remainder of the Cu-Ni-Si copper alloy except for the main component, or the remainder except the main component and the sub-additive component, is composed of unavoidable impurities.

(5): Pure copper system containing oxygen (TPC system)

The rolled copper foil 20 is an oxygen-containing pure copper-based (TPC-based) copper material having an oxygen content of 2 to 200 ppm, and the remainder is composed of unavoidable impurities.

The unavoidable impurities are basically metal products, which are present in the raw materials and are inevitably mixed in the manufacturing process. They are originally components which are not intended to be present, but have little influence on the properties of the metal products. Therefore, it is allowed to exist as an impurity.

Fig. 3 is an explanatory view showing a method of manufacturing the rolled copper foil 20 according to the embodiment of the present invention.

As shown in FIG. 3, the rolled copper foil 20 is produced by the basic processes of the first step ST1 to the thirteenth step ST13.

The first step ST1 is a dissolution step of dissolving the raw material, the second step ST2 is a casting step of casting the dissolved raw material to form a rolled material (ingot), and the third step ST3 is a heat treatment for homogenizing the cast structure of the rolled material. Homogenization heat treatment step.

The fourth step ST4 is a hot rolling step. The term "intercalation" refers to rolling in which the metal is heated to a temperature higher than the recrystallization temperature. The fifth step ST5 is a water cooling step, and the sixth step ST6 is for removing the rust scale. Face turning steps.

The seventh step ST7 is a first (intermediate) cold rolling step, and the eighth step ST8 is a first intermediate annealing step for performing intermediate annealing. The term "cold rolling" refers to rolling performed at a temperature range (for example, normal temperature) in which no recrystallization occurs.

The ninth step ST9 is a second intermediate cold rolling step, the tenth step ST10 is a second intermediate annealing step, and the eleventh step ST11 is a third intermediate cold rolling step.

The twelfth step is a final annealing step for performing the final annealing, and the thirteenth step ST13 is a calendering completion step.

The process of manufacturing the rolled copper foil 20 of the present embodiment is characterized by the first intermediate annealing step of the eighth step ST8 and the second intermediate annealing step of the tenth step ST10, the second before the final annealing step of the twelfth step ST12. In the intermediate annealing step, the temperature increase rate and the reaching temperature are set under the following conditions.

In the second intermediate annealing step of the tenth step ST10, the temperature increase rate is set to be higher than the temperature increase rate of the general intermediate annealing, and the speed at which the recrystallization precursor phenomenon is generated is not given, and the annealing temperature is set. In order to suppress the preferential movement of the specific boundary particle diameter, a randomized recrystallized structure can be obtained, which is higher than the upper limit temperature of the recrystallization of the copper alloy.

The rolled copper foil 20 of the present embodiment is characterized in that the temperature rise rate of the second intermediate annealing in the tenth step ST10 is 2 ° C /sec or more, and the temperature reaches 800 ° C or higher.

That is, the rolled copper foil 20 of the present embodiment is heated at a speed of several ° C or at a speed of several tens of ° C.

The characteristics of the surface structure, the crystal orientation, the method of controlling the crystal orientation, the alloy composition, and the like of the rolled copper foil 20 of the present embodiment will be specifically described below, and the above (1) to (5) are also specifically described. The examples of the copper alloy will be described in comparison with the reference examples and the comparative examples.

[surface texture]

Fig. 4 is a schematic view showing a strip-shaped uneven portion in the surface structure of the rolled copper foil and a low uneven portion found in the strip-shaped uneven portion.

In Fig. 4, 1H indicates a strip-shaped uneven region, and 1L indicates a low uneven portion.

Fig. 5 is a schematic view showing a state in which the surface of the rolled copper foil 20 of the present embodiment has a large number of strip-like irregularities.

In the present embodiment, the area of the strip-shaped uneven region 1H shown in Fig. 4 is divided by the entire area as the area ratio.

An area ratio of more than 60% is a necessary condition for guaranteeing the uniformity of roughening plating. It is preferably 70% or more, more preferably 80% or more.

The rolled copper foil 20 of the present embodiment shown in Fig. 5 has a state in which strips have a large number of irregularities.

[crystal orientation]

In the rolled copper foil 20, the smaller the RDW orientation, the higher the area ratio of the strip-shaped uneven regions, and the better the roughening plating is performed, and the area ratio of the RDW is 15% or less, preferably 12% or less. More preferably, it is 8% or less.

Figure 6 is a graphical representation of the EBSD measurement results.

Figure 4 shows the Brass direction, S-bit defined as the calendered assembly. The angle formed by the angle between the region facing the RDW and the adjacent measurement point is 15° or more.

The Brass orientation and the S-direction region RGN-BS are divided into crystal grains having a size of about 10 μm in the rolling direction (RD, the left-right direction of the figure), and the size thereof corresponds to the strip-shaped unevenness.

On the other hand, in the region RGN-R where the RDW is located, although the crystal grain has a slope in the orientation, it does not have a crystal grain boundary, and coarse crystal grains are formed in the RD direction, which corresponds to a region having no strip-like irregularities.

The cause of the specificity of this RDW orientation is due to the fact that the work of the crystal slip is small. The influence on the crystal orientation of the slip deformation of the polycrystalline material is a Taylor model (for example, J. Inst. Metals, 62 (1938), 307-324), and the Taylor factor corresponds to the above work amount.

The Taylor factor in the Brass orientation and the S-position calender deformation is 3.3 and 3.5, respectively, whereas the RDW position has a Taylor factor of 2.4, which is the lowest of all crystal orientations.

That is, in the case where the high-work rate foil rolling step, the lattice defect density such as the misalignment and the void are remarkably high, the Brass position and the S-position are less likely to cause crystal slip, by the shear band and the crystal boundary The formation assumes deformation, causing the crystal grains to break, and as a result, a cavity is formed in the calendered surface.

On the other hand, the RDW position undergoes deformation due to crystal slip, and only one crystal grain is elongated, and a new crystal boundary is not formed in the crystal, and as a result, a surface having few pits is formed.

In this specification, the crystal orientation indicates that the method is to take the rolling direction of the material. (RD) is the X-axis, the width direction (TD) of the material is taken as the Y-axis, and the normal direction of the rolling (ND) is taken as the coordinate system of the Z-axis, and each region in the material is perpendicular to the Z-axis (with the calendering surface). The index (hk1) of the crystal plane of (XY plane) parallel and the index [uvw] of the crystal plane perpendicular to the X axis (parallel to the YZ plane) is expressed as the form of (hk1) [uvw].

Further, as in (120) [001] and (210) [001], etc., the symmetry of the cubic crystal of the copper alloy is referred to, and the equivalent bitwise direction is expressed by the brackets {hk1}<uvw> indicating the same series.

In the present embodiment, the analysis of the crystal orientation described above uses the EBSD method. The so-called EBSD method is the abbreviation of Electron Back Scatter Diffraction, which refers to the reflection of the reflected electron Kikuchi line generated by irradiating an electron beam to a sample in a Sacnning Electron Microscope (SEM). (Kikuchi diagram) crystal orientation analysis technology.

In the present embodiment, the sample area of 5 square micrometers or more is scanned in steps of 0.2 μm for analysis of the orientation.

The area ratio refers to the area of the area within 13° from the ideal position deviation angle, divided by the ratio calculated by dividing the entire measurement area.

From the ideal position to the deviation angle, the rotation angle is calculated from the common rotation axis to set the deviation angle.

Fig. 7 is a diagram showing an example in which the direction of deviation from the RDW position is within 13°.

Although the orientations within 13° of the (001), (101) and (111) axes are shown in Figure 7, the RDW position is calculated for all the axes here. Corner. Here, the shaft can be used to exhibit the smallest deviation angle.

Although the data obtained by the analysis of the EBSD position includes the electron beam to carry out the bit direction data of the depth of the sample of 10 nm, it is relatively small with respect to the breadth of the measurement, and is represented by the area ratio in the present specification. In addition, the orientation distribution is measured from the surface of the board.

[Controlling the process of crystallization to the process]

This shows the manufacturing process for controlling the effectiveness of the crystallographic orientations studied in the embodiment of the present invention.

Further, as described above, the area ratio of the region where the surface unevenness of the strip pattern in the direction of 60° to 120° in the rolling direction is satisfied is 60% or more, and the RDW position of the crystal on the surface is directed thereto. The area ratio of the area within 13 degrees from the {012}<100> direction is 15% or less, and is not limited to the manufacturing process shown here.

As shown in FIG. 3, the manufacturing process for controlling the rolled copper foil 20 in the crystal orientation is the basic step from the first step ST1 to the thirteenth step ST13.

That is, including a dissolution step, a casting step, a homogenization heat treatment step, an inter-heat rolling step, a water cooling step, a face turning step, a first (intermediate) cold rolling step, a first intermediate annealing step, and a second intermediate cooling step The manufacturing process of the second intermediate annealing step, the third intermediate cooling step, the final annealing step, the calendering completion step, and the like is a basic step.

In general, the purpose of the intermediate annealing step is to form a process that can be processed by recrystallizing the structure and softening it to cause the material to be hardened by processing and difficult to be processed.

Although the recrystallization temperature of the copper alloy is different from the temperature of the alloy, its It is about 150~800°C (here less than 800°C).

In the embodiment of the present invention, the RDW position to be controlled to be low tends to be not only the preferential growth direction of the recrystallization, but also tends to remain in the non-rotation state even if the rolling is performed.

Therefore, the RDW orientation in the tissue must be reduced in the final annealing of the 12th step ST12.

According to the method for producing a rolled copper foil 20 of the present embodiment, in the second intermediate annealing step of the tenth step ST10, the temperature rise rate can be set to 2 ° C /sec or more, and the temperature can be 80 ° C or higher. .

The formation of the preferential orientation during recrystallization can be considered to be affected by the difference in the recovery rate of each crystallographic position, but it is to increase the temperature increase rate, not to give the recrystallization precursor phenomenon, and to arrive. The temperature is increased to suppress the preferential movement of a specific crystal boundary to obtain a randomized recrystallized structure.

The annealing speed is preferably in the range of 5 ° C / sec or more, more preferably 10 ° C / sec or more. Although the upper limit is not set here, the maximum is 200 ° C / sec.

The preferred temperature range is 870 ° C or higher, and more preferably 950 ° C or higher. The upper limit is 1000 ° C where the material will exhibit high temperature brittleness.

When this randomized recrystallization heat treatment is performed in the final annealing in the twelfth step ST12, since the coarse crystal grains are caused by surface cracks and cracks in the corners, they are not intended to be carried out. Therefore, the crystal grain size after the final annealing is preferably 30 μm or less.

[alloy composition]

The above-described effect of controlling the crystal orientation can be applied to various alloys.

Moreover, the necessary characteristics of the copper foil may vary depending on the overall design of the battery, and it is preferable to select an appropriate alloy in response to this characteristic. The relationship between the strength and electrical conductivity of the calendered foil is the same, and the properties of each alloy are listed in Table 1.

In Table 1, the Cu-(Cr, Zr)-based copper alloy of the present embodiment has a tensile strength of 400 to 700 MPa, and the conductivity is 70 to 95% IACS (International Annealed Copper Standard; International Annealed Copper Standard).

Here, the 70% IACS system is a wire having 100% conductivity when the "standard annealed copper" of the resistivity IACS (International Annealing Copper Standard) is 100%.

The Cu-(Cr, Zr)-based copper alloy has an electrical conductivity of 70 to 95% IACS and has good electrical properties.

Similarly, the Cu-Ag-based copper alloy of the present embodiment has a tensile strength of 350 to 550 MPa and an electrical conductivity of 80 to 98% IACS.

This Cu-Ag-based copper alloy has high electrical conductivity of 80 to 98% IACS.

The Cu-Sn-based copper alloy of the present embodiment has a tensile strength of 400 to 750 MPa and an electrical conductivity of 15 to 95% IACS.

The conductivity of this Cu-Sn-based copper alloy is 15 to 95% different. However, high electrical (battery) characteristics can be obtained by optimizing the amount of ingredients added to the main component and the sub-additive component.

The Cu-Ni-Si-based copper alloy of the present embodiment has a tensile strength of 600 to 1000 MPa and a conductivity of 20 to 50% IACS.

The conductivity of the Cu-Ni-Si-based copper alloy is slightly lower than that of 20 to 50%. However, by optimizing the amount of the main component and the sub-additive component, it is known that electrical properties can be obtained according to the purpose ( Battery) characteristics.

The pure copper-based (TPC) copper material of the present embodiment has a tensile strength of 350 to 550 MPa and a conductivity of 95 to 100% IACS.

This pure copper-based copper material is known to have a high electrical conductivity of 95 to 100% IACS.

When the predetermined upper limit component of the copper alloy of each of the above (1) to (5) is added, the second phase is dispersed in the form of an oxide, a precipitate, or a crystal, and the second phase is dispersed. When it is extended to a thickness of 12 μm or less, it is not recommended because it causes pinholes and breakage. In addition, it is not recommended because of the significant decrease in conductivity.

Further, when the predetermined lower limit component of the copper alloys of the above (1) to (5) is not added, sufficient addition effect cannot be obtained. It is preferable that the amount of the component to be added is appropriately adjusted in accordance with the above use.

The total content of the main components Cr and Zr contained in the Cu-(Cr, Zr)-based copper alloy is preferably from 0.15 to 0.43 mass%, more preferably from 0.22 to 0.31 mass%.

The content of Ag as a main component of the Cu-Ag system is preferably 0.02 to 0.15 mass%, more preferably 0.03 to 0.05 mass%.

The content of the main component Sn of the Cu-Sn system is preferably 0.1 to 2.3% by mass. More preferably, it is 0.6 to 0.9% by mass.

The content of the main component Ni of the Cu-Ni-Si system is preferably from 2.1 to 4.2% by mass, more preferably from 3.4 to 3.9% by mass.

In addition to the above main components, in order to improve strength, heat resistance, and the like, a sub-additive element such as Sn, Zn, Si, Mn, Mg, or P may be added.

In particular, in the rolling to a thickness of 12 μm or less, the addition of Si, Mg, P, or the like can deoxidize the molten metal, suppress the formation of the oxide, and suppress the formation of sulfide by the addition of Mn. , can effectively solve the pinhole problem caused by the internal second phase.

Alloys containing more added elements have a tendency to form more RDW orientations than pure copper. This is because the calendered assembly is converted from pure copper to brass.

Therefore, in the embodiment of the present invention, the higher the concentration of the alloy, the more remarkable the effect. That is, the preferred alloy to which the embodiment of the present invention is applied is a Cu-Ag system, and more preferably, the alloy is a Cu-Sn system, a Cu-Ni-Si system, and a Cu-Cr system.

Further, in the present embodiment, a copper foil having a thickness of 12 μm or less is used as an example, but it may be applied to a copper foil having a thickness of 12 μm or more.

[Examples]

Specific embodiments of the invention are described below.

The results of the examples are shown in Tables 2 to 6 below.

The evaluation results of the examples of the Cu-(Cr, Zr) system are shown in Table 2. The evaluation results of the examples of the Cu-Ag system are shown in Table 3. The evaluation results of the examples of the Cu-Sn system are shown in Table 4, Cu. The results of the evaluation of the -Ni-Si system are listed in The results of the evaluation of the examples in Table 5 and pure copper are listed in Table 6.

The evaluation results of the copper alloy examples of the above (1) to (5) are also compared with the reference examples and the comparative examples in Tables 2 to 6.

Before describing the evaluation results of the examples in Tables 2 to 6, the method for producing the rolled copper foil of the present embodiment and the comparative example, the method for evaluating the rolled copper foil before roughening plating, and the battery evaluation method are used. Description.

[Manufacturing method of rolled copper foil]

Here, a method of manufacturing a rolled copper foil according to an embodiment of the present embodiment will be described with reference to Fig. 3 .

In the first step ST1, the raw material is melted in a high-frequency melting furnace, and the melted raw material is cast in a second step ST2 at a cooling rate of 0.1 to 100 ° C / sec to obtain an ingot. The ingot contains the alloy composition as shown in Tables 2 to 6, and the remainder is formed by Cu and inevitable impurities.

In the third step ST3, the ingot obtained in the second step ST2 is subjected to a homogenization heat treatment at a temperature of 800 to 1030 ° C for 5 minutes to 10 hours, and in the state thereof, the heat is performed in the fourth step ST4. Calendering.

After the hot working is performed in the fourth step ST4, the water is cooled in the fifth step ST5, and the surface turning is performed in the sixth step ST6 to remove the scale.

Thereafter, the first (intermediate) cold rolling is performed in the seventh step ST7, the first intermediate annealing is performed in the eighth step ST8, and the second intermediate cold rolling is performed in the ninth step ST9. Further, in the tenth step ST10, the second intermediate annealing is performed, the third intermediate cold rolling is performed in the eleventh step ST11, and the final annealing is performed in the twelfth step ST12. The step of calendering is carried out in ST13 to produce a rolled foil having a foil thickness of 12 μm or less.

The first (intermediate) cold rolling in the seventh step ST7, the second intermediate cold rolling in the ninth step ST9, the third intermediate cold rolling in the eleventh step ST11, and the calendering completion step in the thirteenth step ST13 The calendering process is carried out at a foil thickness reduction rate of 66 to 99%.

The first intermediate annealing in the eighth step ST8 and the annealing heat treatment in the final annealing in the twelfth step ST12 are maintained at a temperature of 300 ° C or more and less than 800 ° C at a normal recrystallization temperature for 3 seconds to 10 hours.

Here, the second intermediate annealing in the tenth step ST10 is carried out under the conditions of a temperature increase rate of 2 ° C /sec or more and a temperature of 800 ° C or more and 1000 ° C or less.

After each heat treatment and rolling, oxygen removal and surface grinding are performed in accordance with the state of oxidation and roughness of the surface of the material, and the shape is adjusted by a tension leveler.

An example of the production method of the above embodiment is referred to as step A.

Further, the comparisons in Tables 2 to 6 are as shown in Fig. 8, and are produced by any of the following steps E to I.

[Step E]

Step E is the same as step A except that the temperature increase rate of the second intermediate annealing in the tenth step ST10 is set to 0.2 to 1.8 ° C / sec, and the reaching temperature is set to 300 ° C or more and less than 800 ° C or less.

[Step F]

Step F except for the second intermediate annealing of the tenth step ST10 The speed is set to 0.2 to 1.8 ° C / sec, and the arrival temperature is set to 800 ~ 1000 ° C, the rest are the same as step A.

[Step G]

Step G is the same as step A except that the temperature increase rate of the second intermediate annealing in the tenth step ST10 is set to 0.2 ° C /sec or more, and the reaching temperature is set to 300 ° C or more and less than 800 ° C or less.

[Step H] (method described in Japanese Patent Laid-Open Publication No. 2000-328159)

In the H step, the electric furnace is melted under the coating of charcoal in the atmosphere to melt into an ingot of 50 mm x 80 mm x 180 mm, which is heat-calendered to form a thick piece having a thickness of 15 mm, and then After hot-rolling at 820 ° C to form a sheet having a thickness of 3.3 mm, water cooling was performed.

For these sheets, the thickness of 1.2 mm is subjected to cold rolling, and the intermediate annealing is performed at a furnace temperature of 750 ° C for x 20 s, and the thickness is 0.4 mm for cold rolling, and then the intermediate annealing is performed at a furnace temperature of 700 ° C for x 20 s. The 0.2 mm was subjected to cold rolling, and then annealed at a furnace temperature of 650 ° C for x 20 s, followed by cold rolling to prepare a copper alloy foil having a thickness of 10 μm.

This step H is disclosed in Patent Document 4 (Japanese Patent Laid-Open Publication No. 2000-328159).

[Step I] (method described in Japanese Patent Laid-Open Publication No. Hei 11-310864)

In the step I, after the ingot is subjected to the soaking treatment, the inter-heat rolling is performed at the end temperature of 500 ° C, and then, the crystal grain of the copper foil is used to cool the room. The conditions of each step of rolling and final annealing are carried out in the range of 10 to 95% of the cold rolling ratio before the final annealing, the final annealing temperature of 400 ° C or more, and the cold rolling ratio after the final annealing of 10 to 99%.

This step I is disclosed in Patent Document 5 (Japanese Patent Laid-Open Publication No. Hei 11-310864).

The following test was performed on the rolled copper foil before roughening plating. The test results are listed in Table 2 to Table 6.

[Area ratio of strip-shaped concave and convex areas: AR1]

In the optical micrograph, the area ratio of the strip-shaped uneven area is AR1, and the area where the strip-shaped unevenness is confirmed in the direction of the rolling direction of 60° to 120° is blackened, and then image processing is performed to perform black and white color gradation. The black area divided by the entire area is the area ratio. The area of the field of view is 200,000 square microns, which is the average of the three fields of view.

[RDW bit-to-area ratio: AR2]

The RDW orientation area ratio AR2 was measured by the above-described method from the calendered surface by the above-described EBSD method. When the pattern is not clear due to the thickness of the processed surface of the rolled surface, the measurement can be performed by chemically grinding only the outermost layer.

[tensile strength (TS), elongation (EL)]

Tensile strength (TS) and elongation (EL) were measured in a tensile test in the direction of parallel rolling according to JIS Z2241.

[Electrical conductivity (EC)]

The specific resistivity was measured by a four-probe method in a thermostat maintained at 20 ° C (± 0.5 ° C) to calculate the conductivity. In addition, the distance between the probes is 100 mm.

Thereafter, a battery was fabricated in the following manner, and its battery characteristics were evaluated.

[Method of roughening plating]

The finely roughened particles on the surface of the rolled copper foil were subjected to the following copper plating conditions.

<Electrolysis cell composition>

Cu (metal): 60~70 g/L

Sulfuric acid: 110~130 g/L

<Electrolysis conditions>

Temperature: 45~55°C

Current density: 60~70 A/dm ²

Processing time: 0.4~2.0 seconds

[Battery test 1: Carbon-based anode active material]

(i) positive electrode

90% by weight of LiCoO ₂ powder, 7% by weight of graphite powder, and 3% by weight of polyvinylidene chloride were mixed, and then a solution prepared by dissolving N-methylpyrrolidone in ethanol was added and mixed to prepare a positive electrode slurry. After uniformly coating the slurry on the aluminum foil, it was dried in nitrogen to volatilize the ethanol, and then rolled by a roller to prepare a foil.

After the sheet was cut, the aluminum foil pin was ultrasonically welded to one end thereof to assemble the positive electrode.

(ii) Negative electrode

90% by weight of natural graphite powder (average particle diameter: 10 μm) and 10% by weight of polyvinylidene chloride were mixed, and then a solution prepared by dissolving N-methylpyrrolidone in ethanol was added and mixed to prepare a slurry. Next, the slurry was applied onto both surfaces of the rolled copper foil produced in the examples and the comparative examples, and then The coated copper foil was dried in nitrogen to volatilize the solvent, and then rolled by a roller to form a foil.

After the sheet was cut, the aluminum foil pin was ultrasonically welded to one end thereof to assemble the negative electrode.

(iii) Assembly of the battery

A separator made of polypropylene having a thickness of 25 μm was interposed between the positive electrode and the negative electrode produced by the above method, and this was placed in a battery can plated with nickel on the surface of the soft steel, and the negative electrode pin was placed at the bottom of the can. Welding. Next, it is placed on the cover of the insulating material, inserted into the buffer material, and then ultrasonically welded to the positive electrode lead and the aluminum safety valve to be connected, and then, the propylene carbonate, diethyl carbonate, and ethylene carbonate are used. After the non-aqueous electrolyte solution was injected into the battery can, a lid was attached to the above-mentioned safety valve to assemble a lithium ion secondary battery having a hermetic structure.

(iv) Determination of battery characteristics

The battery produced above was subjected to a charge and discharge cycle test in which a charge of 50 mA was charged to 4.2 V and a cycle of discharging at 50 mA to 2.5 V was performed for one cycle. The battery capacity at the time of initial charge is listed in Table 2 to Table 6.

[Battery test 2: negative electrode active material of lanthanide system]

(i) positive electrode

Using Li ₂ CO ₃ and CoCO ₃ as starting materials, the raw material of the Li:Co atomic ratio of 1:1 is mixed in a mortar, and subjected to heavy pressing and pressure molding in a mold, and then 800 in air. The firing was carried out for 24 hours at ° C to obtain a fired body of Li ₂ CoO ₂ . This was mashed in a mortar to form a powder having an average particle diameter of 20 μm.

90 parts by weight of the obtained Li ₂ CoO ₂ powder, 5 parts by weight of artificial graphite powder as a conductive agent, and 5 parts by weight of N-methyl group containing 5 parts by weight of polyvinylidene chloride as a binder A solution of pyrrolidone to prepare a positive electrode mixed slurry.

This positive electrode mixture slurry was applied onto an aluminum foil as a current collector, dried, and then rolled. After cutting this, it was used as a positive electrode.

(ii) Negative electrode

80.2 parts by weight of an antimony powder (purity: 99.9%) having an average particle diameter of 3 μm as an active material, and mixed with 8.6% by weight of 19.8 parts by weight of polyglycine (adhesive α 1) as a binder A solution of N-methylpyrrolidone was prepared to prepare a negative electrode mixed slurry.

This negative electrode mixture slurry was applied onto the rolled copper foil produced in the examples and the comparative examples, dried, and then rolled. Thereafter, this was subjected to heat treatment at 400 ° C for 30 hours in argon gas, followed by sintering to obtain a negative electrode.

(iii) Assembly of the battery

To a volume-mixed solvent such as ethylene carbonate and diethyl carbonate, LiPF _{6 was} dissolved in a solution of 1 mol/liter to prepare an electrolytic solution. A lithium secondary battery was produced using the above positive electrode, negative electrode, and electrolytic solution.

The positive electrode and the negative electrode are arranged opposite to each other with a separator interposed therebetween.

(iv) Determination of battery characteristics

The battery was evaluated for charge and discharge cycle characteristics. After charging each of the above batteries at a current of 1 mA to 4.2 V at 25 ° C, The discharge was further carried out at 1 mA to 2.75 V, and this was set as a charge and discharge test for one cycle. The discharge capacity after 50 cycles was measured with respect to the discharge capacity of the first cycle to calculate the discharge capacity retention rate.

The test results are listed in Table 2 to Table 6.

In the following, as shown in the respective test results, the strip-shaped uneven regions of the region found in the surface irregularities having the stripe pattern in the direction of 60° to 120° in the rolling direction defined in the embodiment of the present invention are satisfied. When the area ratio AR1 is 60% or more, and the RDW position of the surface crystallization position in the direction of {012}<100> is less than or equal to 15%, the area ratio AR2 is 15% or less. The characteristic results are quite good. On the other hand, in the comparative example manufactured by the manufacturing steps E to I, the area ratio AR1 and the RDW orientation area ratio AR2 of the strip-shaped uneven areas were not satisfied, and the battery test result was poor.

The alloys of Tables 2 through 5 exhibited better battery characteristics relative to the pure copper system as shown in Table 6.

Table 2 lists the test results for Cu-(Cr, Zr) copper alloys.

Here, the rolled copper foil of the present embodiment (in this example) was produced in the production examples in the production steps A to 1-1 to 1-8, in the production step A, the reference examples 1-11, the manufacturing steps E, F, and G, respectively. The test examples 1-21 to 1-25 produced by H and I were tested.

Examples 1-1 to 1-7 and Comparative Examples 1-21 to 1-25 satisfy the condition that the total content of the main components Cr and Zr is 0.01 to 0.9% by mass, and also satisfy the sub-addition components Sn, Zn, Si, Mn, The total content of Mg is 0.01 to 0.45 mass%.

Here, the total content of the sub-addition components of Examples 1-6 was 0.52% by mass, slightly exceeding the condition that the total content of the sub-addition components was 0.01 to 0.45 mass%.

Further, Reference Example 1-11 did not satisfy the condition that the total content of the main components Cr and Zr was 0.01 to 0.9% by mass.

Examples 1-1 to 1-8 satisfy the condition that the area ratio AR1 of the strip-shaped uneven regions is 60% or more.

Examples 1-1 to 1-8 satisfy the condition that the RDW orientation area ratio AR2 is 15% or less.

Further, from the values of the initial charge capacity of the battery test 1 of Examples 1-1 to 1-8 and the maintenance rate of the battery test 2, the characteristic results in the battery test were good.

Further, as described above, the total content of the sub-addition components of Examples 1-6 is 0.52% by mass, although slightly exceeding the condition that the total content of the sub-addition components is 0.01 to 0.45 mass%, the characteristics of the battery test are good, It is known that the content of the main component is within the range defined in the embodiment, and the influence on the electrical characteristics is large.

Examples 1-4 and 1-7 did not contain a sub-additive but satisfied the battery test.

As described above, the content of Cr in the main components Cr and Zr of Reference Example 1-11 was 0.93% by mass, and the condition that the total content of the main component was not satisfied was 0.01 to 0.9% by mass.

Reference Example 1-11 stopped the manufacture because of the large number of pinholes.

From the results of Reference Examples 1 to 11, it can be seen whether or not the content of the main component is within the range defined in the present embodiment, and the influence on the electrical characteristics is large.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 1-21 was 45%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 1-21 was 22% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 1-21 was 342 mAh, which was lower than 481 mAh of Example 1-1, and the battery test 2 retention rate was 16%, which was also half of the 36% of Example 1-1. Still low.

Therefore, the battery test characteristics of Comparative Example 1-21 were inferior to those of the examples.

This result is estimated not because of the manufacturing step A, but because the heating rate of the second intermediate annealing in the tenth step ST10 is set to 0.2 to 1.8 ° C / sec, and the reaching temperature is 300 ° C or higher and less than 800 ° C. The reason for manufacturing.

That is, the temperature rise rate of the second intermediate annealing is not set to the temperature increase rate at which the recrystallization precursor phenomenon is not given, and the reaching temperature is not set to a higher temperature than the recrystallization upper limit temperature of the copper alloy. In order to suppress the preferential movement of the specific particle size boundary and obtain the randomized recrystallized structure, the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, so that the battery characteristics are low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 1-22 was 57%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 1-22 was 16% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 1-22 was 385 mAh, which was lower than 481 mAh of Example 1-1, and the maintenance rate of Battery Test 2 was 13%, which was also half of that of Example 1-1. Still low.

Therefore, the battery test characteristics of Comparative Example 1-22 were inferior to those of the examples.

This is because the second intermediate annealing in the tenth step ST10 of the feature of the manufacturing method (step A) is set to 0.2 to 1.8 ° C / sec without increasing the temperature increase rate for giving the recrystallization precursor phenomenon.

In other words, in the second intermediate annealing characterized by the manufacturing method (step A), even if the reaching temperature is set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and Obtaining a randomized recrystallized structure, since the temperature rise rate of the second intermediate annealing is not high, it is 0.2 to 1.8 ° C / sec, so the area ratio of the strip-shaped uneven area to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and finally the battery is caused. The characteristics are lower.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 1 to 23 was 52%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Examples 1-23 was 17% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 1-23 was 372 mAh, which was lower than 481 mAh of Example 1-1, and the battery test 2 retention rate was 16%, which was also half of the 36% of Example 1-1. Still low.

Therefore, the battery test characteristics of Comparative Examples 1-23 were inferior to those of the examples.

This result is inferred not because of manufacturing step A, but because of the manufacturer In the second intermediate annealing in the tenth step ST10 of the method (step A), the reaching temperature is not set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, and is set to be 300 ° C or higher and less than 800 ° C. Temperature to suppress preferential movement of specific particle size boundaries and to obtain randomized recrystallized structures.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, the reaching temperature is not set to be higher than that of the copper alloy. The high temperature at which the upper limit temperature of the recrystallization is high also suppresses the preferential movement of the specific particle size boundary and obtains the randomized recrystallized structure, so that the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, and finally This causes the battery characteristics to become low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 1 to 24 was 51%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Examples 1-24 was 18% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 1-24 was 362 mAh, which was lower than 481 mAh of Example 1-1, and the battery test 2 retention rate was 17%, which was also half of the 36% of Example 1-1. Still low.

Therefore, the battery test characteristics of Comparative Examples 1-24 were inferior to those of the examples.

This result is inferred not because of the manufacturing step A, but because the second intermediate annealing of the last feature of the manufacturing method (step A) does not set the reaching temperature to a temperature higher than the recrystallization upper limit temperature of the copper alloy to suppress The preferential movement of the specific particle size boundary and the randomized recrystallized structure are obtained.

That is, in the final intermediate annealing of the feature of the manufacturing method (step A), since the reaching temperature is not set to a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and The randomized recrystallized structure is obtained, so that the area ratio of the strip-shaped uneven areas to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and eventually the battery characteristics are lowered.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 1 to 25 was 48%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Example 1-25 was 19% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 1-25 was 362 mAh, which was lower than 481 mAh of Example 1-1, and the maintenance rate of Battery Test 2 was 21%, which was also lower than 36% of Example 1-1. .

Therefore, the battery test characteristics of Comparative Examples 1-25 were inferior to those of the examples.

This result is inferred because the feature of the present manufacturing method (step A) is before the final annealing, and in the feature of the manufacturing method (step A), the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, and In order to suppress the preferential movement of the specific particle size boundary and obtain the randomized recrystallized structure, the second intermediate annealing which sets the reaching temperature to a higher temperature than the recrystallization upper limit temperature of the copper alloy is not performed.

That is, since the present manufacturing method is characterized by the final annealing, due to the feature of the manufacturing method (step A), in order to suppress the preferential movement of the specific particle size boundary and obtain the randomized recrystallized structure, the temperature setting is not performed. It is a second intermediate annealing which is higher than the upper limit temperature of the recrystallization of the copper alloy, and thus the area ratio AR1 and RDW of the strip-shaped uneven regions cannot be satisfied. The condition of the orientation ratio AR2 eventually leads to a decrease in battery characteristics.

Table 3 lists the test results for Cu-Ag copper alloys.

Here, the rolled copper foil of the present embodiment (in this example) was produced in the production examples 2-1 to 2-5 produced in the step A, the reference example 2-11 produced in the production step A, and the manufacturing steps G, H, and I. Comparative Example 2-21~2-23 was tested.

Examples 2-1 to 2-5 and Comparative Examples 2-21 to 2-23 satisfy the condition that the total content of the main component Ag is 0.01 to 0.9% by mass, and also satisfy the sub-addition components Sn, Zn, Si, Mn, and Mg. The total content is 0.01 to 0.45 mass%.

In addition, the total content of the main component Ag of Reference Example 2-11 did not satisfy the condition of 0.01 to 0.9% by mass.

Examples 2-1 to 2-5 satisfy the condition that the area ratio AR1 of the strip-shaped uneven regions is 60% or more.

Examples 2-1 to 2-5 satisfy the condition that the RDW bit orientation area ratio AR2 is 15% or less.

Further, from the values of the initial charge capacity of the battery test 1 of Examples 2-1 to 2-5 and the maintenance rate of the battery test 2, the characteristic results in the battery test were good.

As described above, Reference Example 2-11 satisfies the condition that the content of the main component Ag is 0.95% by mass and the total content of the main components is 0.01 to 0.9% by mass.

Reference Example 2-11 stopped the manufacture because of the large number of pinholes.

From the results of Reference Examples 2 to 11, it can be seen whether or not the content of the main component is within the range defined in the present embodiment, and the influence on the electrical characteristics is large.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 2-21 was 51%, and the condition of 60% or more was not satisfied. RDW bit-to-area ratio AR2 of Comparative Example 2-21 It is 20%, and the condition of 15% or less is not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 2-21 was 355 mAh, which was lower than 432 mAh of Example 2-2, and the maintenance rate of Battery Test 2 was 15%, which was also half of 31% of that of Example 2-2. Still low.

Therefore, the battery test characteristics of Comparative Example 2-21 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-23 produced by the manufacturing step G shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, the reaching temperature is not set to be higher than that of the copper alloy. The high temperature at which the upper limit temperature of the recrystallization is high also suppresses the preferential movement of the specific particle size boundary and obtains the randomized recrystallized structure, so that the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, and finally This causes the battery characteristics to become low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 2-22 was 53%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Example 2-22 was 18% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 2-22 was 361 mAh, which was lower than 432 mAh of Example 2-2, and the battery test 2 retention rate was 13%, which was also 31% higher than that of Example 2-2. Half is still low.

Therefore, the battery test characteristics of Comparative Example 2-22 were inferior to those of the present embodiment.

This reasoning is based on the reason of Comparative Example 1-24 produced by the manufacturing step H shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2. with.

That is, in the final intermediate annealing of the feature of the manufacturing method (step A), since the reaching temperature is not set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and The randomized recrystallized structure is obtained, so that the area ratio of the strip-shaped uneven areas to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and eventually the battery characteristics are lowered.

The area ratio of the strip-shaped uneven regions of Comparative Examples 2 to 23 was 45%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Example 2-23 was 20% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Moreover, the initial charge capacity of Battery Test 1 of Comparative Example 2-23 was 355 mAh, which was lower than 432 mAh of Example 2-2, and the maintenance rate of Battery Test 2 was 11%, which was also half of 31% of Example 2-2. Still low.

Therefore, the battery test characteristics of Comparative Examples 2-23 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-25 produced in the manufacturing step I shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, since the feature of the present manufacturing method is subjected to the final annealing, the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, and the temperature is set to be reached because the feature of the present manufacturing method (step A) is not performed. In order to suppress the preferential movement of the specific particle size boundary and obtain the second intermediate annealing of the randomized recrystallized structure at a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy, the area ratio AR1 of the strip-shaped uneven region cannot be satisfied. The condition of the RDW to the area ratio AR2 eventually leads to a decrease in battery characteristics.

Table 4 lists the test results for Cu-Sn copper alloys.

Here, the rolled copper foil of the present embodiment (in this example) was produced in the production examples 3-1 to 3-6 in the production step A, the reference example 3-111 manufactured in the production step A, and the manufacturing steps G, H, and I. The comparative examples 3-21 to 3-23 were manufactured for testing.

Examples 3-1 to 3-6 and Comparative Examples 3-21 to 3-23 satisfy the condition that the total content of the main component Sn is 0.01 to 4.9 mass%, and it is also satisfied if the sub-addition components Zn, Si, P, and Mg are used. In one case, the total content is 0.01 to 0.45 mass%.

In addition, the total content of the main component Sn of Reference Example 3-11 did not satisfy the condition of 0.01 to 4.9 mass%.

Examples 3-1 to 3-6 satisfy the condition that the area ratio AR1 of the strip-shaped uneven regions is 60% or more.

Examples 3-1 to 3-6 satisfy the condition that the RDW orientation area ratio AR2 is 15% or less.

Further, from the values of the initial charge capacity of the battery test 1 of Examples 3-1 to 3-6 and the maintenance rate of the battery test 2, the characteristic results in the battery test were good.

The content of the main component Sn in Reference Example 3-11 was 5.12% by mass, and the condition that the content of the main component was not satisfied was 0.01 to 4.9% by mass.

Reference Example 3-11 stopped the manufacture because of the large number of pinholes.

From the results of Reference Example 3-11, it was found that whether or not the content of the main component is within the range defined in the present embodiment has a large influence on electrical characteristics.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 3-21 was 57%, and the condition of 60% or more was not satisfied. Comparative Example 3-21 RDW bitwise area ratio AR2 It is 18%, and the condition of 15% or less is not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 3-21 was 375 mAh, which was lower than 441 mAh of Example 3-1, and the maintenance rate of Battery Test 2 was 15%, which was also half of 31% of that of Example 3-1. Still low.

Therefore, the battery test characteristics of Comparative Example 3-21 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-23 produced by the manufacturing step G shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, the reaching temperature is not set to be higher than that of the copper alloy. The high temperature at which the upper limit temperature of the recrystallization is high also suppresses the preferential movement of the specific particle size boundary and obtains the randomized recrystallized structure, so that the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, and finally This causes the battery characteristics to become low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 3-22 was 51%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 3-22 was 22% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 3-22 was 375 mAh, which was lower than 441 mAh of Example 3-1, and the battery test 2 retention rate was 13%, which was also 31% of that of Example 3-1. Still low.

Therefore, the battery test characteristics of Comparative Example 3-22 were inferior to those of the examples.

This reasoning is based on the reason of Comparative Example 1-24 produced by the manufacturing step H shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2. with.

That is, in the final intermediate annealing of the feature of the manufacturing method (step A), since the reaching temperature is not set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and The randomized recrystallized structure is obtained, so that the area ratio of the strip-shaped uneven areas to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and eventually the battery characteristics are lowered.

The area ratio of the strip-shaped uneven regions of Comparative Examples 3 to 23 was 40%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Example 3-23 was 23% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 3-23 was 340 mAh, which was lower than 441 mAh of Example 3-1, and the maintenance rate of Battery Test 2 was 11%, which was also 31% of that of Example 3-1. Still low.

Therefore, the battery test characteristics of Comparative Examples 3-23 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-25 produced in the manufacturing step I shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, since the feature of the present manufacturing method is subjected to the final annealing, the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, and the temperature is set to be reached because the feature of the present manufacturing method (step A) is not performed. In order to suppress the preferential movement of the specific particle size boundary and obtain the second intermediate annealing step of the randomized recrystallized structure at a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy, the area ratio AR1 of the strip-shaped uneven region cannot be satisfied. The condition of the ratio of the RDW to the area ratio AR2 eventually leads to a decrease in battery characteristics.

The test results of the Cu-Ni-Si copper alloy are listed in Table 5.

Here, the rolled copper foil of this embodiment (this example) is separately manufactured in steps. In the examples 4-1 to 4-8 of the production of the step A, the comparative examples 4-21 to 4-23 produced in the reference example 4-11 and the production steps G, F, and I produced in the production step A were tested.

Examples 4-1 to 4-8 and Comparative Examples 4-21 to 4-23 satisfy the condition that the content of the main component Ni is 1.4 to 4.8% by mass, and the content of the main component Si is 0.2 to 1.3% by mass. The condition that the total content of the sub-additive components Sn, Zn, Si, Cr, Mn, Mg, and Co is 0.005 to 0.9% by mass is satisfied.

Among them, the content of the main component Ni of Reference Example 4-11 did not satisfy the condition of 1.4 to 4.8% by mass.

Examples 4-1 to 4-8 satisfy the condition that the area ratio AR1 of the strip-shaped uneven regions is 60% or more.

Examples 4-1 to 4-8 satisfy the condition that the RDW orientation area ratio AR2 is 15% or less.

Further, from the values of the initial charge capacity of the battery test 1 of Examples 4-1 to 4-8 and the maintenance rate of the battery test 2, the characteristic results in the battery test were good.

Reference Example 4-11 did not satisfy the condition that the Ni content in the main component Ni and Si was 4.92 mass%, and the content of the main component Ni was 1.4 to 4.8% by mass.

From the results of Reference Examples 4 to 11, it can be seen whether or not the content of the main component is within the range defined in the present embodiment, and the influence on the electrical characteristics is large.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 4-21 was 54%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 4-21 was 17% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Moreover, the initial charging capacity of Battery Test 1 of Comparative Example 4-21 was 381 mAh was lower than 441 mAh of Example 4-1, and the battery test 2 retention rate was 14%, which was also lower than half of 32% of Example 4-1.

Therefore, the battery test characteristics of Comparative Example 4-21 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-23 produced by the manufacturing step G shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, the reaching temperature is not set to be higher than that of the copper alloy. The high temperature at which the upper limit temperature of the recrystallization is high also suppresses the preferential movement of the specific particle size boundary and obtains the randomized recrystallized structure, so that the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, and finally This causes the battery characteristics to become low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 4-22 was 49%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 4-22 was 21% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 4-22 was 351 mAh, which was lower than 441 mAh of Example 4-1, and the battery test 2 retention rate was 13%, which was also 32% higher than that of Example 4-1. Half is still low.

Therefore, the battery test characteristics of Comparative Example 4-22 were inferior to those of the present embodiment.

This inference is the same as the reason of Comparative Example 1-22 shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the reaching temperature is set to be higher than the recrystallization upper limit temperature of the copper alloy The temperature is also high to suppress the preferential movement of the specific particle size boundary, and the randomized recrystallized structure is obtained. Since the temperature rise rate of the second intermediate annealing is not high, it is 0.2 to 1.8 ° C / sec, so the strip-shaped uneven region cannot be satisfied. The ratio of the area ratio AR1 to the RDW to the area ratio AR2 eventually leads to a decrease in battery characteristics.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 4 to 23 was 43%, and the condition of 60% or more was not satisfied. The RDW of Comparative Examples 4 to 23 had an area ratio AR2 of 24% and did not satisfy the condition of 15% or less.

Moreover, the initial charge capacity of Battery Test 1 of Comparative Example 4-23 was 326 mAh, which was lower than 441 mAh of Example 4-1, and the maintenance rate of Battery Test 2 was 11%, which was also 32% higher than that of Example 4-1. Half is still low.

Therefore, the battery test characteristics of Comparative Examples 4-23 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-25 produced in the manufacturing step I shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, since the present manufacturing method is characterized by the fact that the final heating method is performed, the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, and the temperature is set to be reached because the feature of the present manufacturing method (step A) is not performed. In order to suppress the preferential movement of the specific particle size boundary and obtain the second intermediate annealing step of the randomized recrystallized structure at a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy, the area ratio AR1 of the strip-shaped uneven region cannot be satisfied. The condition of the ratio of the RDW to the area ratio AR2 eventually leads to a decrease in battery characteristics.

The test results for pure copper are listed in Table 6.

Here, Comparative Examples 5-21 of the rolled copper foil of the present embodiment (in this example), which were produced in the manufacturing step A, and the manufacturing steps E, F, G, H, and I, respectively, were carried out. 5-25 for testing.

The oxygen content of Example 5-1 and Comparative Example 5-21 to 5-25 was 180 ppm, and the oxygen content was 2 to 200 ppm.

The oxygen content of Example 5-2 was 6 ppm, and the oxygen content was 2 to 200 ppm.

Examples 5-1 and 5-2 satisfy the condition that the area ratio AR1 of the strip-shaped uneven regions is 60% or more.

Examples 5-1 and 5-2 satisfy the condition that the RDW bit orientation area ratio AR2 is 15% or less.

Further, from the values of the initial charge capacity of the battery test 1 of Examples 5-1 and 5-2 and the maintenance rate of the battery test 2, the characteristic results in the battery test were good.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Example 5-21 was 51%, and the condition of 60% or more was not satisfied. The RDW position of Comparative Example 5-21 was 16% in area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 5-21 was 385 mAh, which was lower than 451 mAh of Example 5-1, and the maintenance rate of Battery Test 2 was 9%, which was about 27% of Example 5-1. /3.

Therefore, the battery test characteristics of Comparative Example 5-21 were inferior to those of the examples.

This reasoning is based on the reason of Comparative Example 1-21 produced by the manufacturing step E shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2. with.

That is, in the second intermediate annealing which is characterized by the present manufacturing method, the temperature increase rate of the second intermediate annealing which is not characterized by the present manufacturing method is set to a temperature increase rate at which the recrystallization precursor phenomenon is not applied, and the temperature setting is reached. In order to suppress the preferential movement of the specific particle size boundary and obtain the randomized recrystallized structure at a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy, the area ratio of the strip-shaped uneven area to the AR1 and RDW aspect ratio cannot be satisfied. The conditions of AR2 eventually lead to lower battery characteristics.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 5 to 22 was 57%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Example 5-22 was 17% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Moreover, the initial charge capacity of Battery Test 1 of Comparative Example 5-22 was 375 mAh, which was lower than 451 mAh of Example 5-1, and the maintenance rate of Battery Test 2 was 8%, which was 27% higher than that of Example 5-1. /3 is still low.

Therefore, the battery test characteristics of Comparative Examples 5-22 were inferior to those of the present embodiment.

This reasoning is the same as that of Comparative Example 1-22 which is produced in the manufacturing step F shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

In other words, in the second intermediate annealing characterized by the manufacturing method (step A), even if the reaching temperature is set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and Obtaining a randomized recrystallized structure, since the temperature rise rate of the second intermediate annealing is not high, it is 0.2 to 1.8 ° C / sec, so the area ratio of the strip-shaped uneven area to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and finally the battery is caused. The characteristics are lower.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 5 to 23 was 43%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Examples 5 to 23 was 24% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 5-23 was 355 mAh, which was lower than 451 mAh of Example 5-1, and the maintenance rate of Battery Test 2 was 6%, which was 1/7% of that of Example 5-1. 4 or less.

Therefore, the battery test characteristics of Comparative Examples 5-23 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-23 produced by the manufacturing step G shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the second intermediate annealing characterized by the manufacturing method (step A), even if the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, the reaching temperature is not set to be higher than that of the copper alloy. The high temperature at which the upper limit temperature of the recrystallization is high also suppresses the preferential movement of the specific particle size boundary and obtains the randomized recrystallized structure, so that the area ratio of the strip-shaped uneven area to the AR1 and RDW bit area ratio AR2 cannot be satisfied, and finally This causes the battery characteristics to become low.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 5 to 24 was 55%, and the condition of 60% or more was not satisfied. The RDW of Comparative Examples 5 to 24 had an area ratio AR2 of 19% and did not satisfy the condition of 15% or less.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 5-24 was 365 mAh, which was lower than 451 mAh of Example 5-1, and the maintenance rate of Battery Test 2 was 9%, which was about 27% of Example 5-1. /3.

Therefore, the battery test characteristics of Comparative Examples 5-24 were inferior to those of the present embodiment.

This reasoning is the same as the reason of Comparative Example 1-24 produced by the manufacturing step H shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, in the final intermediate annealing of the feature of the manufacturing method (step A), since the reaching temperature is not set to a temperature higher than the recrystallization upper limit temperature of the copper alloy, the preferential movement of the specific particle size boundary is suppressed, and The randomized recrystallized structure is obtained, so that the area ratio of the strip-shaped uneven areas to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and eventually the battery characteristics are lowered.

The area ratio AR1 of the strip-shaped uneven regions of Comparative Examples 5 to 25 was 46%, and the condition of 60% or more was not satisfied. The RDW orientation of Comparative Examples 5-25 was 17% in the area ratio AR2, and the condition of 15% or less was not satisfied.

Further, the initial charge capacity of Battery Test 1 of Comparative Example 5-25 was 370 mAh, which was lower than 451 mAh of Example 5-1, and the maintenance rate of Battery Test 2 was 6%, which was 1/7% of Example 5-1. 4 or less.

Therefore, the battery test characteristics of Comparative Examples 5-25 were inferior to those of the examples.

This reasoning is the same as the reason of Comparative Example 1-25 produced in the manufacturing step I shown in the test results of the Cu-(Cr, Zr)-based copper alloy of Table 2.

That is, since the feature of the present manufacturing method is subjected to the final annealing, the temperature increase rate is set to a temperature increase rate at which the recrystallization precursor phenomenon is not given, and the temperature is set to be reached because the feature of the present manufacturing method (step A) is not performed. A high temperature higher than the upper limit temperature of the recrystallization of the copper alloy to suppress the preferential movement of the specific particle size boundary and obtain a randomized recrystallization group Since the second intermediate annealing is woven, the area ratio of the strip-shaped uneven areas to the AR1 and RDW orientation area ratio AR2 cannot be satisfied, and eventually the battery characteristics are lowered.

As described above, the area ratio AR1 of the strip-shaped unevenness region which is found in the surface unevenness of the strip pattern in the direction of 60° to 120° in the rolling direction which is proposed in the embodiment of the present invention is 60% or more, and the surface is crystallized. When the RDW bit of the bit direction is less than or equal to 15% of the RDW bit area ratio AR2 within the range of {012}<100>, the battery test characteristics are good.

Further, in the second intermediate annealing in the method for producing a rolled copper foil according to the present embodiment (manufacturing step A), the temperature increase rate is set so as not to give a temperature increase rate at which the recrystallization precursor phenomenon occurs, and the temperature is set to be reached. It is a high temperature higher than the upper limit temperature of the recrystallization of the copper alloy to suppress the preferential movement of the specific particle size boundary, and obtain a randomized recrystallized structure to satisfy the area ratio of the strip-shaped uneven area to the area ratio of the AR1 and the RDW. The conditions of AR2, in turn, give good battery test characteristics.

On the other hand, the comparative example manufactured by the manufacturing steps E to I did not satisfy the conditions defined by the area ratio AR1 and the RDW bit area ratio AR2 of the strip-shaped uneven areas, and the battery test result was inferior.

Further, the alloys of Tables 2 to 5 showed better battery characteristics with respect to the pure copper system shown in Table 6.

According to the present embodiment, since the roughened plating surface having uniform unevenness is formed, the adhesion between the current collector and the active material is good, and thus the separation of the current collector and the active material in the production and use of the manufactured product such as a battery can be prevented. . Moreover, as the initial discharge capacity of the battery is good, it is possible to prevent repeated charging. The discharge capacity after the discharge cycle is lowered, and the high performance of the secondary battery can be achieved.

The present invention is not limited to the alloys shown in the examples, and may be applied to, for example, a Cu-Fe system, a Cu-Ti system, a Cu-Be system, a Cu-Zn system, a Cu-Ni system, a Cu-Al system, or the like. Any copper alloy.

The present invention can be applied not only to the above-mentioned carbon-based and cerium (Si)-based negative electrode active materials, but also to battery negative electrode current collectors composed of various active materials such as tin (Sn) and the above-mentioned composite system, and the present invention The effect is not limited to the battery configuration shown in this embodiment.

The rolled copper foil according to the embodiment of the present invention can be applied to a flexible circuit board (FPC), a tape carrier type wafer carrier package (TCP, TAB), a soft board wafer (COF), or the like.

10‧‧‧Lithium secondary battery

11‧‧‧ positive

12‧‧‧negative

13‧‧‧ positive current collector

14‧‧‧Negative current collector

15‧‧‧Baffle

16‧‧‧positive side battery can

17‧‧‧Negative side battery can

18‧‧‧Insulated packaging

20‧‧‧Depressed copper foil

1 is a schematic view showing a lithium secondary battery using a rolled copper foil as a negative electrode current collector according to an embodiment of the present invention.

Fig. 2 is a schematic enlarged view showing a rolled copper foil according to an embodiment of the present invention.

Fig. 3 is an explanatory view showing a method of manufacturing a rolled copper foil according to an embodiment of the present invention.

Fig. 4 is a schematic view showing a strip-shaped uneven portion in the surface structure of the rolled copper foil and a low uneven portion found in the strip-shaped uneven portion.

Fig. 5 is a schematic view showing a state in which the surface of the rolled copper foil according to the present embodiment has a large number of strip-like irregularities.

Figure 6 is a graphical representation of the EBSD measurement results.

Fig. 7 is a diagram showing an example in which the direction of deviation from the RDW position is within 13°.

Fig. 8 is a flow chart showing the manufacturing method of the comparative example.

10‧‧‧Lithium secondary battery

11‧‧‧ positive

12‧‧‧negative

13‧‧‧ positive current collector

14‧‧‧Negative current collector

15‧‧‧Baffle

16‧‧‧positive side battery can

17‧‧‧Negative side battery can

18‧‧‧Insulated packaging

Claims (17)

A rolled copper foil for a secondary battery current collector, which is a rolled copper foil composed of copper or a copper alloy formed by calendering, wherein the surface crystallization position is 13° from the RDW position to the {012}<100> direction The area ratio within the area is 15% or less. The rolled copper foil for a secondary battery current collector according to the first aspect of the invention, wherein the area ratio of the area of the strip pattern of the strip pattern of 60° to 120° with respect to the rolling direction is 60%. the above. The rolled copper foil for a secondary battery current collector according to claim 1 or 2, which comprises a Cu-(Cr, Zr)-based copper alloy whose main component is at least one of Cr and Zr, the main component thereof The total content of at least one of Cr and Zr is from 0.01 to 0.9% by weight. The rolled copper foil for a secondary battery current collector according to claim 3, wherein a total content of at least one of Sn, Zn, Si, Mn, and Mg in the sub-additive component is 0.01 to 0.45 wt%. The rolled copper foil for a secondary battery current collector according to claim 1 or 2, which comprises a Cu-Ag-based copper alloy whose main component is Ag, and the total content of Ag of the main component is 0.01 to 0.9 weight. %. The rolled copper foil for a secondary battery current collector according to claim 5, wherein a total content of at least one of Sn, Zn, Si, Mn, and Mg of the sub-additive component is 0.01 to 0.45 wt%. The rolled copper foil for a secondary battery current collector according to claim 1 or 2, wherein the Cu-Sn-based copper alloy having a main component of Sn has a total content of Sn of 0.01 to 4.9 by weight. %. The rolled copper foil for a secondary battery current collector according to claim 7, wherein a total content of at least one of Zn, Si, P, and Mg of the sub-additive component is 0.01 to 0.45 wt%. The rolled copper foil for a secondary battery current collector according to claim 1 or 2, wherein the Cu-Ni-Si-based copper alloy having a main component of Ni and Si has a Ni content of 1.4 to a main component. 4.8% by weight, the Si content is 0.2 to 1.3% by weight. The rolled copper foil for a secondary battery current collector according to claim 9, wherein the total content of at least one of Sn, Zn, Si, Cr, Mn, Mg, and Co of the sub-additive component is 0.005 to 0.9. weight%. The rolled copper foil for a secondary battery current collector according to claim 1 or 2, which comprises a pure copper system of oxygen, having an oxygen content of 2 to 200 ppm. The rolled copper foil for a secondary battery current collector according to any one of claims 3 to 11, wherein the remaining portion except the main component or the remaining portion other than the main component and the sub-additive component It consists of unavoidable impurities. A method for producing a rolled copper foil for a secondary battery current collector, which comprises a rolled copper foil for a rolled copper foil for a secondary battery current collector according to any one of claims 1 to 12, comprising: heat The inter-calendering step of heating the calendered material to a temperature above the recrystallization temperature for inter-heat rolling; at least two intermediate cold-column rolling steps, after the inter-heat rolling step, at a temperature at which no recrystallization occurs Performing cold rolling; at least one intermediate annealing step, in the above intermediate cold rolling step Intermediate annealing is performed at a specific temperature and at a specific temperature increase rate; and a final annealing step is performed at a specific temperature and at a specific temperature increase rate after the last intermediate cold rolling step Performing the final annealing, in the intermediate annealing step before the final annealing step, the temperature increase rate is set to a speed at which no recrystallization precursor phenomenon occurs, and the reaching temperature is set to suppress the preferential movement of the specific boundary particle diameter, and The high temperature of the randomized recrystallized structure can be obtained. The method for producing a rolled copper foil for a secondary battery current collector according to claim 13, wherein in the intermediate annealing step before the final annealing step, the reaching temperature is higher than a recrystallization upper limit of the copper alloy The temperature is high. The method for producing a rolled copper foil for a secondary battery current collector according to claim 13 or claim 14, wherein in the intermediate annealing step before the final annealing step, the temperature increase rate is 2 ° C /sec or more The above-mentioned reaching temperature is a high temperature of 800 ° C or higher. The method for producing a rolled copper foil for a secondary battery current collector according to any one of claims 13 to 15, further comprising: a first intermediate cold rolling step, after the hot pressing step Cold rolling; a first intermediate annealing step, performing intermediate annealing after the first intermediate cold rolling step; a second intermediate cold rolling step, performing cold rolling after the first intermediate annealing step; and second intermediate annealing a step of performing an intermediate annealing after the second intermediate cold rolling step; and a third intermediate cold rolling step, performing cold rolling after the second intermediate annealing step, wherein the final annealing step is performed in the third intermediate cooling chamber After the calendering step, the second intermediate annealing step is performed in the intermediate annealing step performed before the final annealing step, and the temperature increasing rate is set to a speed at which no recrystallization precursor phenomenon is generated, and the reaching temperature is set to suppress specific boundary particles. The diameter moves preferentially and the high temperature of the randomized recrystallized structure can be obtained. The method for producing a rolled copper foil for a secondary battery current collector according to any one of claims 13 to 16, wherein before the hot pressing step, a homogenization heat treatment step is further included to The material is calendered and subjected to homogenization heat treatment.