KR20140057584A - Rolled copper foil for secondary battery collector and production method therefor - Google Patents

Abstract

Provided is a rolled copper foil for a secondary battery current collector which is difficult to be plastically deformed due to its large amount of elastic deformation and which can improve the yield and electrical characteristics of a manufacturing process of a battery and the like. A rolled copper foil (20) for a secondary battery current collector made of copper or a copper alloy formed by rolling, characterized in that the area ratio S (111) of the region facing the (111) face in the rolling direction with respect to the crystal orientation, (111) / S (100)] of the area ratio S (100) of the area facing the (100)

Description

TECHNICAL FIELD [0001] The present invention relates to a rolled copper foil for a secondary battery current collector,

The present invention relates to a rolled copper foil applicable to a current collector for a secondary battery and a method of manufacturing the same. More particularly, the present invention relates to a rolled copper foil having a wide elastic limit and a method of manufacturing the same.

The rolled copper foil is used for an anode current collector of a secondary battery such as a lithium ion battery, and is coated with, for example, a carbon-based active material. Such an anode current collector is manufactured by applying an active material to a rolled copper foil by a roll press. However, in a press by a roll, the copper foil is deformed, and there is a problem that the active material falls off or yield deteriorates due to the defective shape. In recent years, the thinning of the whole house has been progressed, and this problem becomes more and more prominent.

Further, in accordance with a recent demand for improvement of the battery capacity, a change from a carbon system to a silicon (Si) system or a tin (Sn) system active material has been studied.

However, such a new active material has a problem that the expansion / contraction amount due to charging / discharging is larger than that of the carbon system, so that the new active material is separated from the current collector during use. This is considered to be one of the causes of the plastic deformation of the current collector when the active material expands.

BACKGROUND ART [0002] With the recent demand for improving the capacity of a battery, the release of active material is a main cause of capacity decrease. Furthermore, the importance of active materials having a large expansion and shrinkage such as Si or Sn system is expected to increase.

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

Several improvements have been proposed for improving the mechanical properties of the rolled copper foil (see, for example, Patent Documents 1 to 6).

In Patent Document 1, it has been proposed to increase the tensile strength by alloying. The higher the tensile strength, the higher the yield stress.

In Patent Document 2, it has been proposed to increase the tensile strength of the current collector. If the tensile strength is high, it is estimated that the yield stress also increases.

Patent Document 3 proposes to increase the Young's modulus after softening the copper alloy foil by a heat treatment at 300 캜 for 30 minutes.

In Patent Document 4, it is shown that the Young's modulus is reduced by rolling the pure copper copper plate at a rolling rate of 96% and increasing the cube texture by heating at 250 ° C for one hour.

In Patent Documents 5 and 6, a method of reducing the Young's modulus to the tensile stress of the material by controlling the Zn amount and the Sn amount has been proposed.

Japanese Patent Application Laid-Open No. H11-339811 WO2001 / 031723 Japanese Patent Application Laid-Open No. 2009-242846 Japanese Patent Application Laid-Open No. 55-05454 Japanese Patent Application Laid-Open No. 2001-294957 Japanese Patent Application Laid-Open No. 2003-306732

However, in the copper foils disclosed in the above Patent Documents 1 and 2, only the yield stress is increased, and the modulus of longitudinal elasticity against tensile stress can not be lowered.

In the case of the copper foil disclosed in Patent Document 3, since the softening is performed, the yield stress is low and the longitudinal elastic modulus against the tensile stress is increased, so that the limit elastic deformation amount is narrowed.

In the case of the copper foil disclosed in Patent Document 4, since the yield stress is low since it is softened, it is insufficient to enlarge the limit elastic deformation amount.

In the copper foils disclosed in Patent Documents 5 and 6, since the amount of the solid solution element is large, the conductivity is remarkably lowered.

Therefore, there has been a case where such a copper foil can not satisfy a high demand for a recent battery.

An object of the present invention is to provide a rolled copper foil for a secondary battery current collector and a method of manufacturing the same, in which plastic deformation is difficult due to a large amount of critical elastic deformation, and yield and yield of a manufacturing process of a battery and the like can be improved It is on.

In the present invention, the longitudinal elastic modulus with respect to tensile stress is controlled by controlling the crystal orientation of the rolled copper foil. Moreover, it has been shown that the control method of the hot rolling step is very effective for controlling the crystal orientation, especially for the production method before rolling to the foil.

According to the present invention, there is provided a rolled copper foil for a secondary battery current collector made of copper or a copper alloy formed by rolling, which has an area ratio S (111) of a region facing a (111) face in the rolling direction, (S (111) / S (100)) of the area ratio S (100) of the area facing the (100) face is 2 or less.

Here, the area ratio is calculated by dividing the area of the area where the deviation angle from the ideal orientation is within 15 占 by the entire measurement area.

The rolled copper foil refers to a rolled foil of pure copper, but it means a rolled foil of a copper alloy widely in the present application.

Preferably, the rolled copper foil is a Cu- (Cr, Zr) based copper alloy containing at least one of Cr and Zr as a main component, and contains 0.01 to 0.9 mass% of at least one of Cr and Zr as main components.

Also, the Cu- (Cr, Zr) based rolled copper foil may contain 0.01 to 0.45 mass% of at least one of Sn, Zn, Si, Mn, and Mg as additive components in total.

In addition, the remainder of Cu- (Cr, Zr) based rolled copper foil is formed of unavoidable impurities (inevitable impurities) except for the main component or the main component and auxiliary addition component.

Preferably, the rolled copper foil is a Cu-Ag-based copper alloy containing Ag as a main component and contains Ag in a total amount of 0.01 to 0.9 mass% as a main component.

In addition, the Cu-Ag-based rolled copper foil may contain 0.01 to 0.45% by mass of at least one of Sn, Zn, Si, Mn, and Mg as additive components in total.

Further, the remainder of the Cu-Ag-based rolled copper foil, except for the main component, except for the main component and the minor additive component, is formed by unavoidable impurities.

Preferably, the rolled copper foil is a Cu-Sn-based copper alloy containing Sn as a main component and contains 0.01 to 4.9 mass% of Sn as a main component in total.

In addition, the Cu-Sn-based rolled copper foil may contain 0.01 to 0.45% by mass of at least one of Zn, Si, P, and Mg as additive components in total.

In addition, the remainder of the Cu-Sn-based rolled copper foil, except for the main component, except for the main component and the minor additive component, is formed by unavoidable impurities.

Preferably, the rolled copper foil is a Cu-Ni-Si based copper alloy containing Ni and Si as main components and contains 1.4 to 4.8% by mass of Ni and 0.2 to 1.3% by mass of Si as main components.

Further, the Cu-Ni-Si-based rolled copper foil may contain 0.005 to 0.9 mass% in total of at least one of Sn, Zn, Si, Cr, Mn, Mg,

In addition, the remainder of the Cu-Ni-Si-based rolled copper foil, except for the main component, except for the main component and the minor additive component, is formed by unavoidable impurities.

Preferably, the rolled copper foil is a pure copper system containing oxygen and has an oxygen content of 2 to 200 ppm.

Further, the pure copper-based rolled copper foil is formed by unavoidable impurities.

According to the present invention, there is also provided a method of manufacturing a rolled copper foil for producing a rolled copper foil, which comprises the steps of: A first cooling step of performing cooling after the hot rolling step; a surface finishing step of performing a surface finishing step after the first cooling step; A final cold recrystallization annealing step for performing final recrystallization annealing for a predetermined time at a predetermined temperature after the intermediate cold rolling and a final cold recrystallization annealing step for performing final cold rolling after the final recrystallization annealing, Rolling process, wherein the hot rolling process is carried out at a first heating temperature above the recrystallization temperature A second high temperature rolling process is performed at a second heating temperature lower than the first heating temperature after a first high temperature rolling process in which high temperature rolling is performed, a second cooling process in which cooling is performed after the first high temperature rolling process, and a second cooling process And a second high-temperature rolling step in which the second hot rolling step is performed.

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

According to the present invention, since the amount of critical elastic deformation of the rolled copper foil as a current collector is large, plastic deformation of the current collector can be prevented with respect to an external force in a manufacturing process of a secondary battery or the like. This also makes it difficult for the active material to detach from the current collector, thereby improving the capacity of the secondary battery.

Furthermore, when the rolled copper foil as the current collector deforms due to the deformation of Sn or Si-based active materials having large amounts of expansion and contraction during charging and discharging, deformation of the current collector is within the elastic limit, . ≪ / RTI > Therefore, the separation of the active material and the collector can be prevented, and the charge / discharge cycle characteristics of the secondary battery can be improved.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a schematic configuration of a lithium secondary battery to which a rolled copper foil according to an embodiment of the present invention is applied as an anode current collector. FIG.
2 is a schematic enlarged view of a rolled copper foil according to an embodiment of the present invention.
Fig. 3 is a view for explaining the manufacturing process of the rolled copper foil according to the embodiment of the present invention.
4 is a diagram showing the relationship between the area ratio [S (111) / S (100)] and the elastic modulus against tensile stress.
5 is a view showing a manufacturing process of a comparative example.

BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a diagram showing a schematic configuration of a lithium secondary battery to which a rolled copper foil according to an embodiment of the present invention is applied as an anode current collector. FIG.

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

The lithium secondary battery 10 shown in Fig. 1 includes a positive electrode 11, a negative electrode 12, a positive electrode collector 13, a negative electrode collector 14, a separator 15, a positive electrode side battery can 16, A battery can 17, and an insulating packing 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 by the positive electrode side battery can 16 and the negative electrode side battery can 17.

In this accommodated state, the anode 11 is connected to the anode-side battery can 16 via the cathode current collector 13, and the cathode 12 is connected to the cathode-side battery can 17 via the anode current collector 14. [ Respectively.

With this structure, the secondary battery 10 can be charged and discharged.

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

The rolled copper foil 20 according to the present embodiment is formed with the following characteristics, for example, the thickness d being set to 12 μm or less.

The rolled copper foil 20 has an area ratio S (111) of the area ratio S (111) of the region facing the (111) face in the rolling direction to the area ratio S ) / S (100)] is 2 or less.

As the crystal orientation, crystal orientation measurement by electron backscattering diffraction (EBSD method) is applicable.

The rolled copper foil 20 according to the present embodiment is formed as a copper alloy or a pure copper system as shown in the following (1) to (5).

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

The rolled copper foil 20 is a Cu- (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component and is formed as a copper alloy containing at least one of Cr and Zr as a main component in a total amount of 0.01 to 0.9 mass% do.

Also, the Cu- (Cr, Zr) based copper alloy is formed as a copper alloy containing at least one kind of Sn, Zn, Si, Mn, and Mg as total of 0.01 to 0.45 mass%

The Cu- (Cr, Zr) based copper alloy is formed by inevitable impurities (inevitable impurities) with the remainder excluding the main component, or the remainder excluding the main component and the additive component.

(2): Cu-Ag-based copper alloy

The rolled copper foil 20 is a Cu-Ag-based copper alloy containing Ag as a main component and is formed as a copper alloy containing Ag in a total amount of 0.01 to 0.9 mass% as a main component.

Further, the Cu-Ag-based copper alloy is formed as a copper alloy containing 0.01 to 0.45% by mass of at least one of Sn, Zn, Si, Mn, and Mg as auxiliary addition components, if necessary.

In the Cu-Ag-based copper alloy, the remainder excluding the main component, or the remainder excluding the main component and the minor additive component, is formed by unavoidable impurities.

(3): Cu-Sn-based copper alloy

The rolled copper foil 20 is a Cu-Sn-based copper alloy containing Sn as a main component and is formed as a copper alloy containing 0.01 to 4.9 mass% of Sn as a main component in total.

Further, the Cu-Sn-based copper alloy is formed as a copper alloy containing 0.01 to 0.45% by mass of at least one of Zn, Si, P, and Mg as auxiliary addition components, if necessary.

In the Cu-Sn-based copper alloy, the remainder excluding the main component or the remainder excluding the main component and the auxiliary additive component is formed by the inevitable impurities.

(4): Cu-Ni-Si based copper alloy

The rolled copper foil 20 is a Cu-Ni-Si based copper alloy containing Ni and Si as main components and is formed as a copper alloy containing 1.4 to 4.8% by mass of Ni and 0.2 to 1.3% by mass of Si as main components.

Also, the Cu-Ni-Si based copper alloy is formed as a copper alloy containing 0.005 to 0.9 mass% in total of at least one of Sn, Zn, Si, Cr, Mn, Mg,

In the Cu-Ni-Si-based copper alloy, the remainder excluding the main component, or the remainder excluding the main component and the minor additive component, is formed by inevitable impurities.

(5): pure oxygen system (TPC system)

The rolled copper foil 20 is a pure copper (TPC) copper material containing oxygen with an oxygen content of 2 to 200 ppm and the balance of unavoidable impurities.

Here, inevitable impurities are generally present in raw materials in metal products or inevitably incorporated in the manufacturing process. Although it is originally unnecessary, it is an impurity that is allowed because it has a small amount and does not affect the characteristics of a metal product.

3 is a diagram for explaining a manufacturing process of the rolled copper foil 20 according to the present embodiment.

As shown in Fig. 3, the rolled copper foil 20 is manufactured by using the first step (ST1) to eleventh step (ST11) as basic steps.

The first step ST1 is a dissolving step for dissolving the raw material and the second step ST2 is a casting step for casting the molten raw material to form ingots under pressure. The third step (ST3) It is a homogenization heat treatment process that is a heat treatment to homogenize the casting structure of serial materials.

The fourth step (ST4) is a first high temperature rolling step, the fifth step (ST5) is a cooling step, and the sixth step (ST6) is a second high temperature rolling step. The hot rolling process including the first high temperature rolling process, the cooling process and the second high temperature rolling process is formed. Hot rolling refers to rolling performed by heating a metal to a recrystallization temperature or higher. The seventh step ST9 is a intermediate cold rolling step, the tenth step ST10 is a final cold rolling step, and the seventh step ST7 is a water cooling step, the eighth step ST8 is a cutting step for removing an oxide scale, Annealing, and the eleventh step (ST11) is a final cold rolling step. Cold rolling refers to rolling performed at a temperature range (for example, room temperature) in which recrystallization does not occur.

The characteristic process for manufacturing the rolled copper foil 20 according to the present embodiment is that the first high-temperature rolling in the fourth step (ST4) is a high-temperature rolling at a first heating temperature, for example, 670 DEG C or higher, And the second high-temperature rolling in step (ST6) is a high-temperature rolling at a second heating temperature lower than the first heating temperature, for example, 650 DEG C or lower.

The characteristic points of the above-described 0.2% strength of the crystal orientation of the rolled copper foil 20 according to the present embodiment, the manufacturing process for controlling the crystal orientation, the alloy components, etc. will be described in detail. Examples of the copper alloy will be described in connection with the reference examples and comparative examples.

[Crystal orientation]

In a typical rolled copper foil, rolling aggregate structure is developed. (Rolling stability orientation) of a general copper alloy has a certain width, but the brass direction in which the (112) plane is oriented in the rolling direction and the brass direction in which the (112) ) Face, and Copper bearing facing the (111) face are generally used. However, these (112) and (346) plane orientations have no significant effect on the decrease of the longitudinal elastic modulus with respect to the tensile strength, and the (111) plane orientation increases the longitudinal elastic modulus with respect to the tensile strength.

On the other hand, it has been confirmed that (100) plane orientation is effective in the embodiment of the present invention.

In the embodiment of the present invention, the area ratio of the region in which the (100) plane is oriented in the rolling direction is S (100) and the area ratio of the region in which the (111) plane is oriented in the rolling direction is S It is effective to lower the area ratio [S (111) / S (100)].

4 (A) and 4 (B) are diagrams showing the relationship between the area ratio [S (111) / S (100)] and the longitudinal elastic modulus (Young's modulus) against tensile strength.

The longitudinal elastic modulus (Young's modulus) against the tensile strength shown in Fig. 4 was measured as follows. The distance between the gaps between the gaps in the short axis tensile test was measured by a camera type non-contact extensometer, and the distortion was measured. And the slope of the straight portion of the elastic region in the obtained stress-strain curve was measured. The camera type non-contact extensometer was DVE-201 (trade name) manufactured by Shimadzu Corporation. The marking mark is automatically followed by the CCD camera image to measure the elongation rate. The test specimens were strips with a width of 13 mm.

Further, the measurement of the longitudinal elastic modulus (Young's modulus) of the foil may be measured by a vibration method. The vibration method is a measurement method in which a forced vibration is applied to measure a resonance frequency (natural frequency), and a Young's modulus is calculated from the resonance frequency. There are some problems in applying this measurement method to a rolled copper foil having a thickness of about 10 mu m, and it has been sometimes difficult to evaluate it correctly. First, since the measurement is performed by a small amount of displacement, the elastic vibration is not stable due to a small number of wrinkles or bent portions of the test material, resulting in a large variation in the evaluation result. Secondly, since the bending stress is applied, the influence of the unevenness in the vicinity of the thin surface layer which is mainly deformed is strongly received, and the influence of the inside of the foil is not reflected. Third, when the rolled copper foil is used as a battery, the compression and tensile deformation are performed by the active material applied on both sides, whereas the bending deformation by the vibration method is essentially compressive on one side and tensioned on the other side. And to evaluate different deformation states. Therefore, in this application, the longitudinal elastic modulus (Young's modulus) was evaluated by a tensile test.

Also, as described in Maruzen Publishing Co., Ltd., p19 (1980), "Mechanical Properties of Metallic Materials" published by the Society of Mechanical Engineers of Japan, the dynamic method represented by the vibration method and the static method represented by the tensile test, Are different from each other. The occurrence of the difference in the evaluation result is not limited to the night.

4 shows the influence of the area ratio [S (111) / S (100)] on the longitudinal elastic modulus with respect to the tensile strength of the copper alloy. It has been confirmed that a typical copper alloy has a longitudinal elastic modulus to tensile strength of about 130 GPa but can be reduced by 20% or more.

In Fig. 4, the area ratio [S (111) / S (100)] is 0.43 to 1.98, which is 2 or less, and the modulus of longitudinal elasticity is 130 GPa to 125 GPa. In addition, when the area ratio [S (111) / S (100)] is more than 2 and 2.2 and 2.4, the longitudinal elastic modulus with respect to tensile strength is 132 GPa and 136 GPa, respectively.

That is, by forming the rolled copper foil 20 so that the area ratio [S (111) / S (100)] is 2 or less as shown in Fig. 4, it is possible to suppress the increase in the longitudinal elastic modulus with respect to the tensile strength.

When the area ratio [S (111) / S (100)] was 2 or less, the battery characteristics were excellent as described later.

In other words, by forming the rolled copper foil 20 so that the area ratio [S (111) / S (100)] is 2 or less, it is possible to suppress the increase in the longitudinal elastic modulus with respect to the tensile strength, .

The ratio [S (111) / S (100)] is preferably 2 or less, more preferably 1.5 or less, and most preferably 1.0 or less. The lower limit is not particularly limited but is 0.05 or more.

The EBSD method (Electron Back Scatter Diffraction) is used for the analysis of the crystal orientation in the present embodiment. EBSD is a crystal orientation analysis technique using a reflected electron Kikuchi ray diffraction (Kikuchi pattern) that occurs when a sample is irradiated with an electron beam in a scanning electron microscope (SEM).

In the present embodiment, the sample is scanned in steps of 0.2 占 퐉 for a sample area of 50,000 square micrometers or more and the orientation is analyzed.

The area ratio is calculated by dividing the area of a region where the deviation angle from the ideal orientation is within 15 占 by the entire measurement area.

The information obtained in the orientation analysis by the EBSD method includes azimuth information to the depth of several tens of nm at which the electron beam penetrates the sample but is sufficiently small for the area to be measured and is therefore described as the area ratio in this specification.

[0.2% proof strength]

To increase the critical elastic deformation amount, the 0.2% proof stress is preferably 400 MPa or more. More preferably at least 500 MPa, and even more preferably at least 600 MPa. The design of such an intensity band depends on the selection of an alloy system described later.

Here, the 0.2% history is defined as follows.

In order to provide a boundary between elastic deformation and plastic deformation for convenience, the stress corresponding to the yield stress is used as the proof stress, and the permanent strain at yielding of the steel is about 0.2% (0.002). The stress is referred to as 0.2% proof stress.

[Process for controlling crystal orientation]

For example, as shown in Patent Documents 3 and 4, if the cube texture is developed, the area ratio S (100) of the region in which the (100) surface in the rolling direction is oriented can be increased.

However, the cubic texture is developed by recrystallization and can not be increased in the processed tissue such as rolled copper foil. In order to widen the critical elastic deformation amount, an increase in the proof stress is also indispensable and work hardening by rolling is indispensable, and a technique of annealing the foil and applying the recrystallization preferential orientation can not be applied.

The manufacturing process for controlling the crystal orientation in which the effectiveness is found in the embodiment of the present invention. As described above, the area ratio of the region in which the (100) plane is oriented in the rolling direction is S (100) and the area ratio of the region in which the (111) plane is oriented in the rolling direction is S Is not limited to the manufacturing process shown here if it satisfies [S (111) / S (100)].

As a manufacturing process of the rolled copper foil 20 for controlling the crystal orientation, the first step (ST1) to the eleventh step (ST11) are the basic steps as shown in Fig.

That is, the manufacturing process includes the melting process, the casting process, the homogenization heat treatment process, the first high temperature rolling process, the cooling process, the second high temperature rolling process, the water cooling process, the machining process, the intermediate cold rolling process, the final recrystallization annealing process, The process becomes the basis.

In the production method of the rolled copper foil 20 according to the present embodiment, the first heating temperature in the first high-temperature rolling is 670 캜 or higher, more preferably 700 캜 or higher, and most preferably 730 캜 or higher.

The second heating temperature in the second high-temperature rolling is 650 ° C or lower, more preferably 620 ° C or lower, and most preferably 590 ° C or lower.

The upper limit temperature of the first high-temperature rolling is 1030 캜, and the lower limit temperature of the second high-temperature rolling is 300 캜. The temperature range between the first high-temperature rolling and the second high-temperature rolling is not processed, and it is necessary to cool by a method such as air cooling or water cooling. The processing ratio of the first high-temperature rolling is 50 to 80%, and the processing ratio of the second high-temperature rolling is 30 to 60%.

A feature of the method of manufacturing a rolled copper foil according to the present embodiment is that the hot rolling is carried out through the cooling step (ST5), the first high temperature rolling (ST4) at a first heating temperature higher than the recrystallization temperature of copper, And the second high-temperature rolling (ST6) of the second heating temperature.

In conventional hot rolling, rolling is carried out at extremely high temperatures in order to reduce the rolling load or rolling pass times and to improve the operating efficiency.

In contrast, in the manufacturing method of the present embodiment, the material is positively cooled between the first high-temperature rolling and the second high-temperature rolling, and a warm rolling structure is formed below the dynamic recrystallization temperature.

[Alloy Ingredients]

The effect of the above-described crystal orientation control can be applied to various alloy systems.

The characteristics required for the copper foil are changed by the design of the whole battery, and an appropriate alloy system may be selected accordingly. The strength and the conductivity of the rolled foil are roughly in trade-off relation, and the characteristics of each alloy system are as shown in Table 1 below.

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

Here, 70% IACS indicates that the conductor has a conductivity of 70% when the electrical resistivity is 100% of the "standard annealing copper wire" referred to as IACS (International Annealing Wire Standard).

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

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

Such a Cu-Ag-based copper alloy exhibits high electrical properties with an electrical conductivity of 80 to 98% IACS.

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

Although such a Cu-Sn-based copper alloy has a conductivity of 15 to 95% and a large variation range, it can exhibit high electric (battery) characteristics by optimizing the amount of added components of the main component and the auxiliary addition component.

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

Although such a Cu-Ni-Si based copper alloy has a slightly low conductivity of 20 to 50%, it can exhibit electric (battery) characteristics depending on the application by optimizing the addition amount of components of the main component and the auxiliary addition component.

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

Such pure copper based copper material exhibits high electrical properties with a conductivity of 95 to 100% IACS.

When the upper limit of the component specified by each of the copper alloys of (1) to (5) is added, it is possible to obtain a copper alloy having a large and submicron sized submicron order in the form of oxides, precipitates, It is dispersed as the second phase, and pinholes and plate breakage are caused at the time of rolling to a thickness of 12 탆 or less, which is not preferable. And the conductivity is remarkably lowered, which is not preferable.

Further, when it is added at less than the lower limit of the component specified by each of the copper alloys of (1) to (5), the effect of the addition is not sufficiently obtained. The amount of the component added is appropriately adjusted according to the use described above.

A preferable range of the total amount of the main components Cr and Zr contained in the Cu- (Cr, Zr) based alloy is 0.15 to 0.43 mass%, and more preferably 0.22 to 0.31 mass%.

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

The preferable range of Sn of the main component of the Cu-Sn system is 0.1 to 2.3 mass%, more preferably 0.6 to 0.9 mass%.

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

Addition of auxiliary additive elements such as Sn, Zn, Si, Mn, Mg and P is allowed for the purpose of improving strength, heat resistance and the like in addition to the above-mentioned main components.

Particularly, the problem that pinholes are generated by the second phase inherent in the rolling up to the thickness of 12 탆 or less can be solved by deoxidizing the molten metal by the addition of Si, Mg, P, It is effective to suppress the formation of sulfides and to inhibit the formation of sulfides by addition of Mn.

The present embodiment is particularly applicable to a copper foil having a thickness of 12 탆 or less, but it can also be applied to a copper foil having a thickness of 12 탆 or more.

Example

Hereinafter, a specific embodiment of the present invention will be described.

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

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

Tables 2 to 6 show evaluation results of the copper alloy examples of (1) to (5) above in comparison with the reference examples and comparative examples.

Before describing the result evaluation of the examples of Tables 2 to 6, a method of manufacturing a rolled copper foil of this embodiment and a comparative example, a method of evaluating a rolled copper foil before roughening plating, a battery evaluation method, and the like will be described.

[Production method of rolled copper foil]

[Process A]

An embodiment of a method for manufacturing a rolled copper foil according to the present embodiment will be described with reference to Fig.

In the first step (ST1), the raw material was dissolved by a high-frequency melting furnace, and the dissolved raw material was cast at a cooling rate of 0.1 to 100 DEG C / sec in the second step (ST2) to obtain an ingot. The ingot contains the alloy components shown in Tables 2 to 6, and the remainder is formed of Cu and unavoidable impurities.

In the third step (ST3), the ingot obtained in the second step (ST2) was subjected to a homogenizing heat treatment at a temperature of 800 to 1030 占 폚 for 5 minutes to 10 hours, and the hot rolling was carried out in the fourth step (ST4).

The first high-temperature rolling with a machining ratio of 50 to 80% at a temperature of 670 to 1030 占 폚 is carried out in a fourth step (ST4), followed by cooling by air cooling to 300 to 650 占 폚 or less in the fifth step (ST5) And subjected to a second high-temperature rolling at a temperature of 300 to 650 占 폚 in the sixth step (ST6) at 30 to 60%.

Subsequently, water cooling was carried out in the seventh step (ST7), and machining was performed in order to remove the oxide scale in the eighth step (ST8).

Thereafter, intermediate cold rolling is performed at a plate thickness reduction rate of 66 to 99% in the ninth step (ST9), and final recrystallization annealing is performed at 300 to 800 DEG C for 3 seconds to 10 hours in the tenth step (ST10) And then subjected to final cold rolling in the eleventh step (ST11) to produce a rolled foil having a thickness of 12 m or less.

After each heat treatment or rolling, pickling or surface polishing was carried out depending on the oxidation or roughness of the material surface, and correction by tension leveler was performed depending on the shape.

An example of the production method according to the present embodiment described above is referred to as [Step A].

The comparative examples in Tables 2 to 6 were produced by any one of the following steps E to I shown in Fig.

[Process E]

Step E is an intermediate annealing in which the first intermediate cold rolling in the ninth step (ST9) and the final recrystallization annealing in the tenth step (ST10) are carried out at a temperature of 300 to 800 DEG C for 3 seconds to 10 hours, And the second intermediate cold rolling at a machining rate was carried out.

[Step F]

The step F was carried out in the same manner as in the step A except that the cooling in the fifth step (ST5) in the step A and the second high-temperature rolling in the sixth step (ST6) were not performed.

[Process G]

Step G is a step in which the second intermediate cold rolling in the ninth step (ST9) and the tenth step (ST10) are carried out without performing the fifth step (ST5) cooling in step A and the second high temperature rolling in the sixth step (ST6) Intermediate annealing in which the temperature was maintained at 300 to 800 占 폚 for 3 seconds to 10 hours, and second intermediate cold rolling at a machining rate of 66 to 99% were carried out during the final recrystallization annealing of the second recrystallization annealing.

[Process H] (a process described in Japanese Patent Laid-Open No. 2000-328159)

Process H was melted in an atmosphere of charcoal in an atmosphere by an electric furnace, and a 50 mm x 80 mm x 180 mm ingot was melted and hot-rolled into a slab having a thickness of 15 mm and hot rolled at 820 캜 to form a slab having a thickness of 3.3 mm Followed by water-cooling.

The sheet material was cold-rolled to a thickness of 1.2 mm, subjected to intermediate annealing at a furnace temperature of 750 ° C x 20S, cold-rolled at a thickness of 0.4 mm, subjected to intermediate annealing at a furnace temperature of 700 ° C x 20S, After cold rolling, intermediate annealing was performed at a furnace temperature of 650 DEG C x 20S, and cold rolling was further performed to produce a copper alloy foil having a thickness of 10 mu m.

This process H is disclosed in Patent Document 7 (Japanese Patent Application Laid-Open No. 2000-328159).

[Process I] (a process described in Japanese Patent Laid-Open No. H11-310864)

Step I is a step of subjecting the ingot to hot rolling at a finish temperature of 500 占 폚 after a soaking treatment and then subjecting each of the steps of cold rolling and final annealing to control the crystal orientation of the copper foil to a cold rolling rate of 10 to & 95%, a final annealing temperature of 400 占 폚 or higher, and a cold rolling rate after final annealing of 10 to 99%.

This process I is disclosed in Patent Document 8 (Japanese Patent Laid-Open Publication H11-310864).

The test production under the conditions disclosed in Patent Document 3 (Japanese Patent Application Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Application Laid-Open No. S55-05455) were also conducted for comparison.

The rolled copper foil before the roughening plating was subjected to the following evaluation. The evaluation results are shown in Tables 2 to 6.

[Area ratio [S (111) / S (100)]]

The area ratio S (111) / S (100) of the area ratio S (100) of the region in which the (100) plane is oriented in the rolling direction and the areal ratio S (111) Was measured from the rolled surface by the above-mentioned method by the EBSD method. When the pattern is not clear because the damaged layer on the rolled surface is thick, only the outermost layer is dissolved by chemical polishing and measured.

By using the crystal orientation analysis technique using the reflected electron Kikuchi ray diffraction (Kikuchi pattern) generated when the electron beam is irradiated on the sample in the SEM by the above-mentioned EBSD method, the sample area of 50,000 square micrometers or more I scanned and interpreted the orientation.

[Tensile strength (TS), 0.2% proof stress (YS), elongation (EL)]

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

[Conductivity (EC)]

The resistivity was measured by a four-terminal method in a thermostatic chamber maintained at 20 ° C (± 0.5 ° C) to calculate the conductivity. The distance between the terminals was set to 100 mm.

Thereafter, a battery was prepared by the following method, and the battery characteristics were evaluated.

[Coating method]

Fine roughened particles were prepared on the surface of the rolled copper foil under the following copper plating conditions.

<Plating bath composition>

Cu (as metal): 60 to 70 g / l

Sulfuric acid: 110 to 130 g / L

&Lt; Plating condition >

Temperature: 45 to 55 DEG C

Current density: 60 to 70 A / dm ²

Processing time: 0.4 to 2.0 seconds

[Battery evaluation 1: Carbon type anode active material]

(i) an anode

90 weight% of LiCoO ₂ powder, 7 weight% of graphite powder and 3 weight% of polyvinylidene fluoride powder were mixed and dissolved in ethanol, and the mixture was kneaded to prepare a positive electrode paste. This paste was uniformly applied to an aluminum foil, and then dried in a nitrogen atmosphere to volatilize ethanol, followed by roll rolling to obtain a sheet.

After cutting the sheet, a lead terminal of an aluminum foil was attached to one end thereof by ultrasonic welding to form a positive electrode.

(ii) cathode

90% by weight of natural graphite powder (average particle diameter 10 占 퐉) and 10% by weight of polyvinylidene fluoride powder were mixed and N-methylpyrrolidone dissolved in ethanol was added and kneaded to prepare a paste. Subsequently, this paste was applied to both surfaces of the rolled copper foil produced in Examples and Comparative Examples. The coated copper foil was dried in a nitrogen atmosphere, the solvent was volatilized, and then rolled to form a sheet.

After cutting the sheet, a lead of nickel foil was attached to one end thereof by ultrasonic welding to form a negative electrode.

(iii) assembly of the battery

A separator made of polypropylene having a thickness of 25 mu m was sandwiched between the positive electrode and the negative electrode manufactured as described above, and this was housed in a nickel-plated battery can on the mild steel surface, and the lead terminal of the negative electrode was spot welded to the bottom of the can. Subsequently, a top cover of an insulating material is provided, and a gasket is inserted. Then, the lead terminals of the positive electrode and the aluminum safety valve are ultrasonically welded to each other. A nonaqueous electrolyte solution composed of propylene carbonate, diethyl carbonate and ethylene carbonate is injected into the battery can , And a cover was attached to the safety valve to assemble a sealed lithium ion secondary battery.

(iv) Measurement of cell characteristics

A charging / discharging cycle test was performed in which the prepared battery was charged up to 4.2 V at a charging current of 50 mA and discharged at 50 mA until it became 2.5 V. The battery capacity at the time of the first charging is shown in Tables 2 to 6.

[Battery evaluation 2: Silicon-based anode active material]

(i) an anode

Using Li ₂ CO ₃ and CoCO ₃ as starting materials, the mixture was weighed so that the atomic ratio of Li: Co was 1: 1, and mixed in a mortar. The mixture was press-molded by a die and then calcined in air at 800 ° C for 24 hours To obtain a sintered body of LiCoO ₂ . This was pulverized in a mortar to prepare an average particle size of 20 mu m.

90 parts by weight of the obtained LiCoO ₂ powder and 5 parts by weight of an artificial graphite powder as a conductive agent were mixed in a 5 wt% N-methylpyrrolidone solution containing 5 parts by weight of polyvinylidene fluoride as a binder to prepare a positive electrode mixture slurry .

The positive electrode mixture slurry was coated on an aluminum foil as a collector, dried and then rolled. The obtained product was cut out to obtain a positive electrode.

(ii) cathode

80.2 parts by weight of silicon powder (purity 99.9%) having an average particle diameter of 3 μm as an active material was mixed with 8.6% by weight of N-methylpyrrolidone solution containing 19.8 parts by weight of polyamic acid (binder α1) as a binder to obtain an anode mixture slurry.

The negative electrode mixture slurry was applied to the rolled copper foil prepared in Examples and Comparative Examples, dried and then rolled. This was heat-treated at 400 ° C for 30 hours in an argon atmosphere and sintered to obtain a negative electrode.

(iii) assembly of the battery

LiPF ₆ in an amount of 1 mol / liter was dissolved in an equal volume of a mixed solvent of ethylene carbonate and diethylene carbonate as an electrolytic solution. A lithium secondary battery was fabricated by using the positive electrode, the negative electrode, and the electrolytic solution.

The positive electrode and the negative electrode are opposed to each other via a separator.

(iv) Evaluation of battery characteristics

The charge-discharge cycle characteristics of the battery were evaluated. Each battery was charged to 4.2 V at a current value of 1 mA at 25 캜, and then discharged to 2.75 V at a current value of 1 mA. This was charged and discharged in one cycle. The discharge capacity after 50 cycles with respect to the discharge capacity in the first cycle was measured as the discharge capacity retention rate.

The evaluation results are shown in Tables 2 to 6.

When the area ratio [S (111) / S (100)] of the areal ratio S specified in the embodiment of the present invention is 2 or less, as shown in the evaluation results of the evaluation of the present invention, did. On the other hand, the comparative example prepared in the production process E to I did not satisfy the condition of the area ratio [S (111) / S (100)] and the battery evaluation result was inferior.

In the process of recrystallization after rolling to the foil of Patent Document 3 (Japanese Patent Application Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Application Laid-Open No. S55-05455), deformation of foil The fracture was remarkable and the characteristics could not be evaluated.

Also, the absolute values of S (111) and S (100) shown in this example were 22.1% to 44.6% and 11.4% to 39.5%, respectively.

Compared to the pure copper system shown in Table 6, the alloy system of Tables 2 to 5 exhibited good battery characteristics.

Table 2 shows the evaluation results of Cu- (Cr, Zr) based copper alloy.

In the examples of Table 2, Examples 1-1 to 1-8, Reference Examples 1-11 and Comparative Examples 1-21 to 1-25 (Comparative Examples 1-21 to 1-25) produced by the manufacturing process A as the rolled copper foil .

The examples 1-1 to 1-8 and the comparative examples 1-21 to 1-25 satisfy the condition that only the main component Cr or the main component Zr or the total of the main components Cr and Zr is contained in the range of 0.01 to 0.9 mass% And when the additive component contains Sn, Zn, Si, Mn, and Mg, the total amount is 0.01 to 0.45 mass%.

However, in Examples 3-6, 0.52% by mass of the total of auxiliary addition components was contained in a total amount of 0.01 to 0.45% by mass.

Examples 1-4 and 1-7 do not contain additions.

Reference Example 1-11 is out of the condition that the total of the main components Cr and Zr is 0.01 to 0.9 mass%.

Examples 1-1 to 1-8 satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less.

It is presumed that Examples 1-1 to 1-8 increase the critical elastic deformation amount in that 0.2% proof stress (YS) is 400 MPa or more under the condition.

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

In addition, Examples 1-4, 1-6, and 1-7 were found to deviate from the range of 0.01 to 0.45 mass% of the total amount of the additive components, but the results were excellent in battery evaluation. It is presumed that whether or not the content of the main component is within the range specified in the present embodiment largely affects the electrical characteristics.

As described above, Reference Example 1-11 contains 0.93% by mass of Cr in the main components Cr and Zr and does not satisfy the condition that the total of the main components is 0.01 to 0.9% by mass.

In Reference Example 1-11, the production was stopped because there were many pinholes.

The results of this Reference Example 1-11 also suggest that whether or not the content of the main component is within the range specified in the present embodiment greatly influences the electrical characteristics.

Comparative Example 1-21 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.85 and is 2 or less.

In Comparative Example 1-21, the first charge capacity as the battery evaluation 1 is low as 341 mAh as compared with 478 mAh in Example 1-1, and the retention rate as the battery evaluation 2 is 18% which is less than half of 38% in Example 1-1.

As described above, in Comparative Example 1-21, the characteristics in evaluating the cell are inferior to those in Examples.

This is an intermediate annealing in which the intermediate annealing is carried out at a temperature of 300 to 800 占 폚 for 3 seconds to 10 hours between the first intermediate cold rolling of the ninth step and the final annealing of the final recrystallization of the ninth step, It is presumed that it is produced by the manufacturing process E which carries out the second intermediate cold rolling.

That is, the hot rolling, which is a feature of the present manufacturing method, was performed as two steps of the first high-temperature rolling at the first heating temperature and the second high-temperature rolling at the second heating temperature lower than the first heating temperature via the cooling period (111) / S (100)] of 2 or less can not be satisfied by carrying out the intermediate annealing step and the second intermediate cold rolling step in addition to the respective steps of the manufacturing process A. Further, It is presumed that the characteristic is lowered.

Comparative Example 1-22 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.32, which is 2 or less.

In Comparative Example 1-22, the initial charge capacity as the battery evaluation 1 was as low as 383 mAh as compared with 478 mAh in Example 1-1 of this example, and the retention rate as the battery evaluation 2 was 15% or less that of 38% to be.

As described above, in Comparative Example 1-22, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is attributed to the fact that the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high temperature rolling at the first heating temperature and then the second high temperature rolling at a second heating temperature lower than the first heating temperature It is estimated that it is doing.

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

Comparative Example 1-23 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.41 and is 2 or less.

In Comparative Example 1-23, the first charge capacity as the battery evaluation 1 is as low as 370 mAh as compared with 478 mAh in Example 1-1, and the retention rate as the battery evaluation 2 is 18% which is less than half of 38% in Example 1-1.

As described above, in Comparative Example 1-23, the characteristics in the evaluation of the cell are inferior to those in this example.

This is because the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high temperature rolling at the first heating temperature and then the second high temperature rolling at the second heating temperature lower than the first heating temperature Intermediate annealing is carried out at a temperature of 300 to 800 占 폚 for 3 seconds to 10 hours between the first intermediate cold rolling and the final recrystallization annealing and the second intermediate cold rolling at a machining ratio of 66 to 99% It is presumed that this is due to that produced by the manufacturing process G.

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is impossible to satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less and the battery characteristics are lowered by performing the intermediate annealing step and the second intermediate cold rolling step which are not in the manufacturing step A. do.

Comparative Example 1-24 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.51 and 2 or less.

In Comparative Example 1-24, the initial charge capacity as the battery evaluation 1 was low as 360 mAh as compared with 478 mAh in Example 1-1 of this example, and the retention rate as the battery evaluation 2 was 19 %to be.

As described above, in Comparative Example 1-24, the characteristics in evaluation of the cell are inferior to those in this example.

This is because the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high temperature rolling at the first heating temperature and then the second high temperature rolling at the second heating temperature lower than the first heating temperature It is presumed that this is produced by the production process H in which the intermediate annealing is carried out twice without performing the cold rolling and the intermediate annealing is carried out through the cold rolling.

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is presumed that the condition that the area ratio [S (111) / S (100)] is 2 or less can not be satisfied and further the battery characteristics are lowered.

Comparative Example 1-25 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.95 and is 2 or less.

In Comparative Example 1-25, the first charge capacity as the battery evaluation 1 is low as 360 mAh as compared with 478 mAh in Example 1-1 of this example, and the retention rate as the battery evaluation 2 is 23% lower than 38% in Example 1-1 .

Thus, in Comparative Example 1-25, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is attributed to the fact that the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high temperature rolling at the first heating temperature and then the second high temperature rolling at a second heating temperature lower than the first heating temperature It is estimated that it is doing.

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

Table 3 shows the evaluation results of the Cu-Ag-based copper alloy.

Evaluation was made on Examples 2-1 to 2-4, Reference Example 2-11 and Comparative Examples 2-21 to 2-23 produced by the manufacturing process A as the rolled copper foil (this example) according to the present embodiment .

In Examples 2-1 to 2-4 and Comparative Examples 2-21 to 2-23, the additive components Sn, Zn, Si, Mn, and Mg were added in such amounts that the total amount of the main components Ag was 0.01 to 0.9 mass% , The total content thereof is 0.01 to 0.45 mass%.

However, Reference Example 2-11 does not satisfy the condition that the total amount of the main component Ag is 0.01 to 0.9 mass%.

Examples 2-1 to 2-4 satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less.

In Examples 2-1 to 2-4, 0.2% proof stress (YS) is 400 MPa or more, which is four conditions, and it is estimated that the limit elastic deformation amount is increased.

As can be seen from the values of the first charging capacity as the battery evaluation 1 and the retention ratios as the battery evaluation 2, the performance in the battery evaluation was good in Examples 2-1 to 2-4.

In Examples 2-11 of Reference Examples, 0.95 mass% of the main component Ag is contained, and the condition that the total of the main components is 0.01 to 0.9 mass% is not satisfied.

In Reference Example 2-11, the production was stopped because there were many pinholes.

It is presumed also from the results of this Reference Example 2-11 that whether or not the content of the main component is within the range specified in this embodiment greatly affects the electrical characteristics.

2-21 of the comparative example does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.66 and is 2 or less.

In Comparative Example 2-21, the first charge capacity as the battery evaluation 1 was 353 mAh as compared with 430 mAh in Example 2-2 of this example, and the retention rate as the battery evaluation 2 was almost half of 33% of Example 2-2 17%.

As described above, in Comparative Example 2-21, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-23 produced in the manufacturing process G shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is impossible to satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less and the battery characteristics are lowered by performing the intermediate annealing step and the second intermediate cold rolling step which are not in the manufacturing step A. do.

2-22 of the comparative example does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.7 or less.

In Comparative Example 2-22, the initial charge capacity as the battery evaluation 1 was 359 mAh as compared with 430 mAh of Example 2-2 of this example, and the retention rate as the battery evaluation 2 was 15% or less, which is half of 33% to be.

Thus, in Comparative Example 2-22, the characteristics in the evaluation of the cell are inferior to those in the examples.

This is presumed to be the same reason as that of Comparative Example 1-24 produced in the manufacturing process H shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is presumed that the condition that the area ratio [S (111) / S (100)] is 2 or less can not be satisfied and further the battery characteristics are lowered.

In Comparative Example 2-23, the condition that the area ratio [S (111) / S (100)] is 2.3 or less is not satisfied.

In Comparative Example 2-23, the initial charge capacity as the battery evaluation 1 was 353 mAh as compared with 430 mAh of Example 2-2 of the present example, and the maintenance rate as the battery evaluation 2 was 13%, which is less than half of 33% to be.

As described above, in Comparative Example 2-23, the characteristics in the evaluation of the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-25 produced in the manufacturing process I shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

Table 4 shows the evaluation results of the Cu-Sn-based copper alloy.

Table 4 shows the evaluation results of Examples 3-1 to 3-6, Reference Example 3-11, and Comparative Examples 3-21 to 3-23 prepared by the manufacturing process A as the rolled copper foil (this example) according to the present embodiment .

In Examples 3-1 to 3-6 and Comparative Examples 3-21 to 3-23, the total amount of main component Sn was 0.01 to 4.9 mass%, and the addition amount of Zn, Si, P and Mg , The total amount is 0.01 to 0.45 mass%.

However, Reference Example 3-11 does not satisfy the condition that the total of the main component Sn is 0.01 to 4.9 mass%.

Examples 3-1 to 3-6 satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less.

It is presumed that Examples 3-1 to 3-6 increase the critical elastic deformation amount in that 0.2% proof stress (YS) is 400 MPa or more under the condition.

As can be seen from the values of the first charge capacity as the battery evaluation 1 and the retention ratios as the battery evaluation 2, the characteristics in the battery evaluation were good in Examples 3-1 to 3-6.

As described above, Reference Example 3-11 contains 5.12 mass% of the main component Sn and does not satisfy the condition of 0.01 to 4.9 mass% of the main component.

In Reference Example 3-11, the production was stopped because there were many pinholes.

It is also presumed from the results of Reference Example 3-11 that whether or not the content of the main component is within the range specified in this embodiment greatly affects the electrical characteristics.

In Comparative Example 3-21, the condition that the area ratio [S (111) / S (100)] is 2.15 or less is not satisfied.

In Comparative Example 3-21, the first charge capacity as the battery evaluation 1 was as low as 373 mAh as compared with 439 mAh in Example 3-1 of this example, and the retention rate as the battery evaluation 2 was almost half of 33% of Example 3-1 in this example Which is about 17%.

As described above, in Comparative Example 3-21, the characteristics in the evaluation of the cell are inferior to those in this example.

This is presumed to be the same reason as that of Comparative Example 1-23 produced in the manufacturing process G shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is impossible to satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less and the battery characteristics are lowered by performing the intermediate annealing step and the second intermediate cold rolling step which are not in the manufacturing step A. do.

In Comparative Example 3-22, the condition that the area ratio [S (111) / S (100)] is 2.33, which is 2 or less, is not satisfied.

In Comparative Example 3-22, the first charge capacity as the battery evaluation 1 was as low as 373 mAh as compared with 439 mAh in Example 3-1 of this example, and the retention rate as the battery evaluation 2 was 15% to be.

As described above, in Comparative Example 3-22, the characteristics in the evaluation of the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-24 produced in the manufacturing process H shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is presumed that the condition that the area ratio [S (111) / S (100)] is 2 or less can not be satisfied and further the battery characteristics are lowered.

3-23 of the comparative example does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.82 and is 2 or less.

In Comparative Example 3-23, the initial charge capacity as the battery evaluation 1 was low as 339 mAh as compared with 439 mAh in Example 3-1 of this example, and the maintenance rate as the battery evaluation 2 was 13%, which is less than half of 33% to be.

As described above, in Comparative Example 3-23, the characteristics in the evaluation of the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-25 produced in the manufacturing process I shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

Table 5 shows the evaluation results of Cu-Ni-Si based copper alloy.

In Examples of Table 5, Examples 4-1 to 4-8 manufactured by Manufacturing Process A, Reference Example 4-11 manufactured by Manufacturing Process A, Manufacturing Process G (Manufacturing Example) manufactured by Manufacturing Process A as the rolled copper foil , F and I in Comparative Examples 4-21 to 4-23 were evaluated.

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

However, Reference Example 4-11 does not satisfy the condition of containing 1.4 to 4.8% by mass of the main component Ni.

In Examples 4-1 to 4-8, the condition that the area ratio [S (111) / S (100)] is 2 or less is satisfied.

It is presumed that Examples 4-1 to 4-8 increase the critical elastic deformation amount in that 0.2% proof stress (YS) is 400 MPa or more under the condition.

As can be seen from the values of the first charge capacity as the battery evaluation 1 and the retention ratios as the battery evaluation 2 in Examples 4-1 to 4-8, the characteristics in the battery evaluation were good.

Reference Example 4-11 does not satisfy the condition of containing 4.92% by mass of Ni in the main component Ni and Si and containing 1.4 to 4.8% by mass of the main component Ni.

In Reference Example 4-11, the production was stopped because the number of pinholes was large.

It is also presumed from the results of Reference Example 4-11 that whether or not the content of the main component is within the range specified in this embodiment greatly influences the electrical characteristics.

4-21 of the comparative example does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.25 and 2 or less.

In Comparative Example 4-21, the initial charge capacity as the battery evaluation 1 was as low as 379 mAh as compared with 439 mAh in Example 4-1 of this example, and the maintenance rate as the battery evaluation 2 was also lower than that of Example 4-1 by 16% to be.

As described above, in Comparative Example 4-21, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-23 produced in the manufacturing process G shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is impossible to satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less and the battery characteristics are lowered by performing the intermediate annealing step and the second intermediate cold rolling step which are not in the manufacturing step A. do.

In Comparative Example 4-22, the area ratio [S (111) / S (100)] is 2.46, which is 2 or less.

In Comparative Example 4-22, the first charge capacity as the battery evaluation 1 is low as 349 mAh as compared with 439 mAh in Example 4-1, and the retention rate as the battery evaluation 2 is 15% which is less than half of 34% in Example 4-1.

As described above, in Comparative Example 4-22, the characteristics in the evaluation of the cell are inferior to those in this example.

This is presumed to be the same reason as that of Comparative Example 1-22 produced in the manufacturing process F shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

In Comparative Example 4-23, the condition that the area ratio [S (111) / S (100)] is 2.78, which is 2 or less, is not satisfied.

In Comparative Example 4-23, the first charge capacity as the battery evaluation 1 is low as 325 mAh as compared with 439 mAh in Example 4-1, and the retention rate as the battery evaluation 2 is 13% which is less than half of 34% in Example 4-1.

As described above, in Comparative Example 4-23, the characteristics in evaluating the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-25 produced in the manufacturing process I shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

Table 6 shows the evaluation results of the pure copper system.

In the examples of Table 6, the comparison made in Examples 5-1 to 5-2 and the manufacturing steps E, F, G, H, I prepared by the manufacturing process A as the rolled copper foil (the present example) Evaluation was conducted for Examples 5-21 to 5-25.

In Example 5-1 and Comparative Examples 5-21 to 5-25, the oxygen amount is 180 ppm and the oxygen amount condition is 2 to 200 ppm.

In Example 5-2 of this example, the oxygen amount is 6 ppm, and the condition of the oxygen amount is 2 to 200 ppm.

In Examples 5-1 and 5-2, the condition that the area ratio [S (111) / S (100)] is 2 or less is satisfied.

It is presumed that Examples 5-1 and 5-2 increase the critical elastic deformation amount in that 0.2% proof stress (YS) is 400 MPa or more under the condition.

As can be seen from the values of the first charge capacity as the battery evaluation 1 and the retention ratios as the battery evaluation 2 in Examples 5-1 and 5-2, the characteristics in the battery evaluation were good.

In Comparative Example 5-21, the condition that the area ratio [S (111) / S (100)] is 2.09 or less is not satisfied.

In Comparative Example 5-21, the first charge capacity as the battery evaluation 1 was low as 383 mAh as compared with 448 mAh in Example 5-1 of the present example, and the retention ratio as the battery evaluation 2 was about 1/3 of 29% of Example 5-1 Of the total.

As described above, in Comparative Example 5-21, the characteristics in the evaluation of the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-21 produced in the manufacturing process E shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method, is rolled as two steps of a first high-temperature rolling at a first heating temperature and a second high-temperature rolling at a second heating temperature lower than the first heating temperature through a cooling period , It is impossible to satisfy the condition that the area ratio [S (111) / S (100)] is 2 or less by performing the intermediate annealing step and the second intermediate cold rolling step in addition to the respective steps of the manufacturing step A. Further, It is presumed that the battery characteristics are lowered.

5-22 of the comparative example does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.44 and is 2 or less.

In Comparative Example 5-22, the initial charge capacity as the battery evaluation 1 was as low as 373 mAh as compared with 448 mAh in Example 5-1 of this example, and the retention rate as the battery evaluation 2 was about 1/3 of 29% of Example 5-1 Of the total.

As described above, in Comparative Example 5-22, the characteristics in the evaluation of the cell are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-22 produced in the manufacturing process F shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

Comparative Example 5-23 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.85 and is 2 or less.

In Comparative Example 5-23, the initial charge capacity as the battery evaluation 1 was 353 mAh as compared with 448 mAh in Example 5-1, and the retention ratio as the battery evaluation 2 was 8% or less, which is 1/3 or less of 29% to be.

As described above, in Comparative Example 5-23, the characteristics in evaluation of the cell are inferior to those in this example.

This is presumed to be the same reason as that of Comparative Example 1-23 produced in the manufacturing process G shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is impossible to satisfy the condition that the ratio [S (111) / S (100)] is 2 or less and the battery characteristics are lowered by performing the intermediate annealing step and the second intermediate cold rolling step which are not in the manufacturing step A do.

Comparative Example 5-24 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.35 and is 2 or less.

In Comparative Example 5-24, the first charge capacity as the battery evaluation 1 was as low as 363 mAh as compared with 448 mAh in Example 5-1 of this example, and the retention rate as the battery evaluation 2 was about 1/3 of 29% of Example 5-1 Of the total.

As described above, in Comparative Example 5-24, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-24 produced in the manufacturing process H shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy of Table 2. [

That is, the hot rolling, which is a feature of the present manufacturing method (step A), is performed after the first high-temperature rolling of the first heating temperature is performed and then the second high-temperature rolling with the second heating temperature lower than the first heating temperature is not performed, It is presumed that the condition that the area ratio [S (111) / S (100)] is 2 or less can not be satisfied and further the battery characteristics are lowered.

Comparative Example 5-25 does not satisfy the condition that the area ratio [S (111) / S (100)] is 2.54 and 2 or less.

In Comparative Example 5-25, the first charge capacity as the battery evaluation 1 was as low as 368 mAh as compared with 448 mAh in Example 5-1 of this example, and the retention rate as the battery evaluation 2 was 1/3 or less of 29% of Example 5-1 8%.

As described above, in Comparative Example 5-25, the characteristics in the evaluation of the battery are inferior to those in Examples.

This is presumed to be the same reason as that of Comparative Example 1-25 produced in the manufacturing process I shown in the evaluation results of the Cu- (Cr, Zr) based copper alloy in Table 2. [

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

As described above, when the area ratio [S (111) / S (100)] of the areal ratio defined in the embodiment of the present invention is 2 or less, the characteristics in evaluation of the battery are good.

The hot rolling as the manufacturing method (manufacturing step A) of the rolled copper foil according to the present embodiment is performed after the first hot rolling of the first heating temperature is performed and then the second hot rolling of the second hot rolling S (111) / S (100)] and the like were satisfied, and the characteristics in the evaluation of the battery were good.

On the other hand, the comparative examples prepared in the production steps E to I did not satisfy the conditions such as the area ratio [S (111) / S (100)] 2 or less, and the battery evaluation results were inferior.

In the process of recrystallization after rolling to the foil of Patent Document 3 (Japanese Patent Application Laid-Open No. 2009-242846) and Patent Document 4 (Japanese Patent Application Laid-Open No. S55-05455), deformation of foil The fracture was remarkable, and the characteristics could not be evaluated.

It can be said that the alloy system of Tables 2 to 5 exhibits good battery characteristics as compared with the pure copper system shown in Table 6.

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

The present invention is not limited to the alloys shown in the present embodiment, but may be applied to copper alloys of all the alloys such as Cu-Fe, Cu-Ti, Cu-Be, Cu-Zn, Cu- Applicable.

The present invention is also applicable to an anode current collector of a battery made of a variety of active materials such as a tin (Sn) system, a system obtained by combining them, as well as the carbon-based or silicon (Si) Is not limited to the configuration of the battery shown in Fig.

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

10 ... Secondary battery
11 ... anode
12 ... cathode
13 ... Anode collector
14 ... Cathode collector
15 ... Separator
16 ... Anode-side battery cans
17 ... Cathode-side battery can
18 ... Insulation packing
20 ... Rolled copper foil

Claims (13)

1. A rolled copper foil made of copper or a copper alloy formed by rolling,
S (100)] of the area ratio S (111) of the region facing the (111) face to the area ratio S (100) of the region facing the (100) face in the rolling direction with respect to the crystal orientation, Is less than or equal to 2
Rolled copper foil for secondary battery collectors. The Cu- (Cr, Zr) -based copper alloy according to claim 1, wherein the Cu- (Cr, Zr) -based alloy containing at least one of Cr and Zr as a main component contains 0.01 to 0.9% by mass of at least one of Cr and Zr as main components
Rolled copper foil for secondary battery collectors. The positive electrode active material according to claim 2, which contains 0.01 to 0.45% by mass of at least one of Sn, Zn, Si, Mn, and Mg as auxiliary addition components
Rolled copper foil for secondary battery collectors. The Cu-Ag-based copper alloy according to claim 1, wherein the main component is Ag-containing Cu-Ag-based copper alloy, which contains 0.01 to 0.9 mass%
Rolled copper foil for secondary battery collectors. 5. The positive electrode active material according to claim 4, which contains 0.01 to 0.45% by mass of at least one of Sn, Zn, Si, Mn, and Mg,
Rolled copper foil for secondary battery collectors. The Cu-Sn-based copper alloy according to claim 1, which contains Sn as a main component and contains 0.01 to 4.9 mass% of Sn as a main component in total
Rolled copper foil for secondary battery collectors. The positive electrode active material according to claim 6, wherein the total amount of at least one of Zn, Si, P, and Mg as additive components is 0.01 to 0.45 mass%
Rolled copper foil for secondary battery collectors. The Cu-Ni-Si-based copper alloy according to claim 1, which contains Ni and Si as main components and contains 1.4 to 4.8% by mass of Ni and 0.2 to 1.3% by mass of Si as main components
Rolled copper foil for secondary battery collectors. 9. The nonaqueous electrolyte secondary battery according to claim 8, wherein 0.005 to 0.9 mass% of at least one of Sn, Zn, Si, Cr, Mn, Mg,
Rolled copper foil for secondary battery collectors. The pure copper system according to claim 1, wherein the oxygen content is in the range of 2 to 200 ppm
Rolled copper foil for secondary battery collectors. 11. The method according to any one of claims 2 to 10, wherein the remainder excluding the main component, or the remainder excluding the main component and the auxiliary addition component is formed of an unavoidable impurity (inevitable impurity)
Rolled copper foil for secondary battery collectors. 12. A method for producing a rolled copper foil for a secondary battery current collector according to any one of claims 1 to 11,
A homogenizing heat treatment process in which a homogenized heat treatment is performed on a forged pressure-
A hot rolling process in which hot rolled steel sheets subjected to homogenization heat treatment are subjected to a plurality of hot rolling processes through a cooling process,
A first cooling step of cooling after the hot rolling step,
A surface finishing step of performing surface finishing after the second cooling step,
An intermediate cold rolling step of performing intermediate cold rolling at a predetermined plate thickness reduction rate after the above-mentioned surface finishing step,
A final recrystallization annealing step for performing final recrystallization annealing for a predetermined time at a predetermined temperature after the intermediate cold rolling, and
A final cold rolling step of performing final cold rolling after the final recrystallization annealing,
The hot rolling process
A first high-temperature rolling step of performing a first high-temperature rolling at a first heating temperature equal to or higher than a recrystallization temperature,
A second cooling step of cooling after the first high-temperature rolling, and
And a second high-temperature rolling step of performing a second high-temperature rolling at a second heating temperature lower than the first heating temperature after the second cooling step
(Method for manufacturing rolled copper foil for secondary battery current collector). 13. The method according to claim 12, wherein the second cooling step is performed only by cooling without performing the processing
(Method for manufacturing rolled copper foil for secondary battery current collector).

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