JP5480444B2 - Rolled copper foil for secondary battery current collector and method for producing the same - Google Patents

Description

  The present invention relates to a rolled copper foil applicable to a current collector for a secondary battery and a method for producing the rolled copper foil, and in particular, rolled copper with improved rough plating performance for the purpose of improving adhesion to an active material. The present invention relates to a foil and a manufacturing method thereof.

The rolled copper foil is used as a negative electrode current collector of a secondary battery such as a lithium ion battery, and is usually used by applying an active material.
Accordingly, various problems occur when the adhesion between the current collector and the active material is poor. For example, the active material falls off due to external stress in the battery manufacturing process. Further, the current collector and the active material are peeled off due to the expansion and contraction of the active material accompanying charging / discharging during use of the battery.

For this reason, the surface of the rolled copper foil is subjected to a roughening treatment by wet plating to positively form a surface with large irregularities, thereby improving the adhesion between the current collector and the active material.
Since the uniformity of the unevenness on the surface after the roughening treatment is ensured by the uniformity of the unevenness on the surface of the copper foil after rolling, the control of the unevenness on the surface during the production of the rolled copper foil for a battery is directly linked to the battery characteristics. It is an important technical issue.

  Against the backdrop of further demands for increasing battery capacity in recent years, the withdrawal of active material is the main cause of capacity reduction. Furthermore, in the active material, since the application of an active material having a large expansion / contraction such as silicon (Si) or tin (Sn) is expected, its importance is particularly increased.

Usually, striped irregularities of 60 to 120 ° with respect to the rolling direction are formed on the surface after rolling. However, there is a problem in that a region having a size of several tens of microns (μm) in the width direction and 100 μm in the longitudinal direction and having no striped unevenness may be formed with respect to the rolling direction.
If the rolled copper foil surface contains many rough areas with less irregularities than the surroundings, when rough plating is performed on the rolled copper foil surface, a rough surface with large variations including small irregularities will be formed. In particular, the active material is exfoliated.

Several proposals have been made regarding the control of the unevenness of the surface of the rolled copper foil (see, for example, Patent Documents 1 to 3).
Patent Document 1 proposes a method of increasing the average interval of unevenness by optimizing rolling conditions, and Patent Document 2 proposes to reduce the average interval of unevenness.
In patent document 3, surface roughness Ra and the average space | interval S of a local peak are shown by the optimal range.

JP 2006-281249 A JP2007-268596 International Publication Number WO2001 / 029912

In the above-mentioned patent document, the area is not controlled only by controlling the interval between one-dimensional irregularities in a certain direction as an index. In addition, glossiness, surface roughness Ra, Rz, and the like are indices based on an average over a wide measurement range, and nonuniformity therein is not controlled.
Moreover, in patent document 1 and 2, the control method is optimization of rolling conditions, and is not a radical thing which eliminates nonuniformity. Therefore, there have been cases where the recent demand for battery applications is not satisfied.

  An object of the present invention is to provide a rolled copper foil for a secondary battery current collector that has a wide region where striped irregularities are formed and is excellent in the uniformity of roughening plating, and a method for producing the same.

The present inventors diligently studied the influence of the crystal orientation on the non-uniform formation of the striped unevenness at each location. And the crystal orientation of the area | region where a striped unevenness | corrugation is not formed is mainly RDW direction {0 1 2} <1 0 0>, and surface unevenness | corrugation is equalized by reducing this orientation of a rolled copper foil surface. The present inventors have found that good adhesion to an active material can be realized, and have reached the present invention.
In addition, the RDW orientation in the rolled copper foil is strongly influenced by the final annealing structure in the manufacturing process and invented a process for controlling it.

According to the present invention, a rolled copper foil made of copper or a copper alloy formed by rolling, and in the crystal orientation of the surface, the area ratio within 13 ° from the RDW orientation {012} <100> orientation is 15% or less. A rolled copper foil is provided.
The rolled copper foil may mean a pure copper rolled foil, but in the present application, it means a rolled copper alloy foil.

  Suitably, the area ratio of the area | region where the surface unevenness | corrugation of the striped pattern of the direction of 60 degrees-120 degrees with respect to a rolling direction is seen is 60% or more.

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

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

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

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

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

  Further, according to the present invention, there is provided a rolled copper foil manufacturing method for manufacturing any one of the rolled copper foils described above, wherein the material to be rolled is heated to a recrystallization temperature or higher and heated. Between the hot rolling step for performing hot rolling, at least two intermediate cold rolling steps for performing cold rolling at a temperature at which recrystallization does not occur after the hot rolling step, and the intermediate cold rolling step , After at least one intermediate annealing step in which intermediate baking is not performed at a predetermined temperature and at a heating rate, and after the final intermediate cold rolling step, at a predetermined temperature and at a predetermined heating rate In the intermediate annealing step that is performed before entering the final annealing step, the temperature increase rate is set to a rate that does not give time for the recrystallization precursor phenomenon. , The reached temperature suppresses the preferential movement of specific grain boundaries, Phased recrystallization texture is set to a high temperature obtained, the production method is provided.

  Preferably, in the intermediate annealing step performed before entering the final annealing step, the reached temperature is higher than the upper limit of the recrystallization temperature of the copper alloy.

  Preferably, in the intermediate annealing step performed before entering the final annealing step, the rate of temperature increase is 2 ° C / second or more, and the ultimate temperature is a high temperature of 800 ° C or more.

  Preferably, the first intermediate cold rolling step in which cold rolling is performed after the hot rolling step, and the first intermediate annealing step in which intermediate annealing is performed following the first intermediate cold rolling step. A second intermediate cold rolling step for performing cold rolling subsequent to the first intermediate annealing step, and a second intermediate annealing step for performing intermediate annealing subsequent to the second intermediate cold rolling step, A third intermediate cold rolling step for performing cold rolling subsequent to the second intermediate annealing step, wherein the final annealing step is performed subsequent to the third intermediate cold rolling step, The annealing step is the intermediate annealing step that is performed before entering the final annealing step, the rate of temperature increase is set to a rate that does not give time for the recrystallization precursor phenomenon, and the ultimate temperature is a specific grain boundary The temperature is set to a high temperature at which the preferential movement is suppressed and a randomized recrystallized structure is obtained.

  Preferably, a homogenization heat treatment step of performing a homogenization heat treatment on the material to be rolled is included before the hot rolling step.

According to the present invention, it is possible to realize a rolled copper foil having a wide area where striped irregularities are formed and having excellent uniformity of rough plating, and to improve the adhesion between the current collector and the active material. it can.
As a result, it is difficult for the active material to drop off from the current collector due to an external force in the manufacturing process of the battery, and the capacity of the secondary battery can be improved. Furthermore, even if an active material such as tin (Sn) or silicon (Si), which has a large expansion / contraction during charging / discharging, is deformed, the active material and the current collector are prevented from being separated, and the secondary battery is charged. -The cycle characteristics of discharge can be improved.

It is a figure which shows schematic structure of the lithium secondary battery with which the rolled copper foil which concerns on embodiment of this invention is applied as a negative electrode collector. It is a figure which expands and shows typically a rolled copper foil concerning an embodiment of the present invention. It is a figure for demonstrating the manufacturing process of the rolled copper foil which concerns on embodiment of this invention. It is a figure which shows the striped uneven | corrugated area | region and the low uneven | corrugated area | region seen between striped uneven | corrugated area | regions in the surface structure of a rolled copper foil. It is a figure which shows a state with many striped unevenness | corrugations in the surface structure of the rolled copper foil which concerns on this embodiment. It is a figure which shows the measurement result by EBSD. It is a figure which shows the example of the azimuth | direction in which the deviation | shift angle from RDW azimuth | direction is within 13 degrees. It is a figure which shows the manufacturing method of a comparative example.

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

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

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

In the present embodiment, a rolled copper foil 20 as shown in FIG. 2 is applied as the negative electrode current collector 14.
The rolled copper foil 20 according to this embodiment has a thickness d set to 12 μm or less, for example, and is formed with the following characteristics.
The rolled copper foil 20 has an area ratio of 60% or more in a region where surface irregularities of a striped pattern in a direction of 60 ° to 120 ° with respect to the rolling direction are seen.
The rolled copper foil 20 has an area ratio within 15 ° of 15% or less from the RDW orientation {012} <100> orientation in the surface crystal orientation.
As the crystal orientation, crystal orientation measurement by electron backscatter diffraction (EBSD method) can be applied.
Moreover, the rolled copper foil 20 which concerns on this embodiment is formed as a copper alloy as shown in the following (1)-(5), or a pure copper type | system | group.

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

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

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

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

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

  Here, inevitable impurities are generally present in raw materials in metal products, or are inevitably mixed in the manufacturing process, and are essentially unnecessary, but are insignificant and affect the characteristics of metal products. It is an acceptable impurity because it does not affect

FIG. 3 is a diagram for explaining a manufacturing process of the rolled copper foil 20 according to the present embodiment.
As shown in FIG. 3, the rolled copper foil 20 is manufactured using the first step ST1 to the thirteenth step ST13 as a basic step.

The first step ST1 is a melting step for melting the raw material, the second step ST2 is a casting step for casting the molten raw material to form a material to be rolled (ingot), and the third step ST3 is a material for rolling the material to be rolled. This is a homogenization heat treatment step that is a heat treatment for homogenizing the cast structure.
The fourth step ST4 is a hot rolling step. Hot rolling refers to rolling performed by heating a metal to a recrystallization temperature or higher. The fifth step ST5 is a water cooling step, and the sixth step ST6 is a chamfering step for removing oxide scale.
The seventh step ST7 is a first (intermediate) cold rolling step, and the eighth step ST8 is a first intermediate annealing step in which intermediate annealing is performed. Cold rolling refers to rolling performed in a temperature range (for example, room temperature) where recrystallization does not occur.
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 in which final annealing is performed, and the thirteenth step ST13 is a finish rolling step.

The characteristic process for producing the rolled copper foil 20 according to the present embodiment is the final annealing step of the twelfth step ST12 among the first intermediate annealing step of the eighth step ST8 and the second intermediate annealing step of the tenth step ST10. In the second intermediate annealing step performed before, the rate of temperature increase and the reached temperature are set as follows.
In the present embodiment, in the second intermediate annealing step of the tenth step ST10, the rate of temperature increase is set to a rate that does not give the time for the recrystallization precursor phenomenon by increasing the temperature increase rate of the normal intermediate annealing, and the arrival of annealing. The temperature is set to a temperature higher than the upper limit of the recrystallization temperature of the copper alloy so that the preferential movement of a specific grain boundary is suppressed and a random recrystallized structure is obtained.
In the production of the rolled copper foil 20 according to the present embodiment, the temperature increase rate in the second intermediate annealing in the tenth step ST10 is 2 ° C./second or more, and the ultimate temperature is 800 ° C. or more. .
Thus, in the manufacture of the rolled copper foil 20 according to the present embodiment, the temperature is increased in steps of several degrees Celsius or steps of several tens of degrees Celsius per second.

  Hereinafter, the above-described surface structure, crystal orientation, manufacturing process for controlling the crystal orientation, the alloy components, and other features of the rolled copper foil 20 according to the present embodiment will be described in detail, and the above (1) to (5) ) Will be described in comparison with reference examples and comparative examples.

[Surface texture]
FIG. 4 is a diagram showing a striped uneven region and a low uneven region seen between the striped uneven region in the surface texture of the rolled copper foil.
In FIG. 4, 1H indicates a striped uneven region, and 1L indicates a low uneven region.
FIG. 5 is a diagram showing a state in which the surface texture of the rolled copper foil 20 according to the present embodiment has a large number of striped irregularities.

In the present embodiment, the area ratio is obtained by dividing the area of the striped uneven region 1H as shown in FIG. 4 by the total area.
An area ratio of 60% or more is necessary to ensure the uniformity of the rough plating. Preferably it is 70% or more, More preferably, it is 80% or more.
The rolled copper foil 20 according to this embodiment shown in FIG. 5 is in a state where there are many striped irregularities.

[Crystal orientation]
In the rolled copper foil 20, the smaller the RDW orientation, the higher the area ratio of the striped uneven region, and good roughening plating is possible. The area ratio of the RDW orientation is 15% or less. Preferably it is 12% or less, More preferably, it is 8% or less.

FIG. 6 is a diagram showing a measurement result by EBSD.
In FIG. 6, the grain boundaries defined by the areas of the Brass orientation, the S orientation, and the RDW orientation, which are rolling textures, and an angle between adjacent measurement points of 15 ° or more are displayed.
The regions RGN-BS of the Brass orientation and the S orientation are divided into crystal grains having a size of about 10 μm in the rolling direction (RD, the left-right direction in the figure), and the size corresponds to the striped unevenness.
On the other hand, the region RGN-R with the RDW orientation has an orientation gradient within the crystal grains, but does not have a crystal grain boundary and is a coarse crystal grain in the RD direction, which does not have a striped unevenness. It can be seen that it corresponds to the area.

The origin of the specificity of such an RDW orientation is that crystal slip is performed with a small amount of work. There is a Taylor model for the influence of crystal orientation on the slip deformation of a polycrystalline material (for example, J. Inst. Metals, 62 (1938), 307-324.), And the Taylor factor corresponds to this work amount.
The Taylor factor in the rolling deformation in the Brass orientation and the S orientation is 3.3 and 3.5, respectively, whereas the Taylor factor in the RDW orientation is 2.4, which is the lowest value among all crystal orientations.
In other words, under the condition that the foil rolling process at a high processing rate is performed and the density of lattice defects such as dislocations and vacancies is remarkably high, the crystallographic slip is less likely to occur in the Brass orientation and S orientation, so that shear bands and grain boundaries are formed. As a result, deformation is carried out and the crystal grains are divided, and as a result, pits are formed on the rolling surface.
On the other hand, since the RDW orientation is deformed by crystal slip, only one crystal grain is elongated and no new grain boundary is formed in the grain, resulting in a surface with few pits.

The crystal orientation display method in the present specification takes a rectangular coordinate system in which the rolling direction (RD) of the material is the X axis, the sheet width direction (TD) is the Y axis, and the rolling normal direction (ND) is the Z axis. The index (h k l) of the crystal plane perpendicular to the Z axis (parallel to the rolling surface (XY plane)) and the index [u of the crystal plane perpendicular to the X axis (parallel to the YZ plane) [u vw] and in the form of (h k l) [u v w].
In addition, parentheses representing families are given for equivalent orientations under the symmetry of copper alloy cubic crystals, such as (1 2 0) [0 0 1] and (2 1 0) [0 0 1]. Symbols are used and denoted as {h k l} <u v w>.

The EBSD method is used for the analysis of the crystal orientation in the present embodiment. EBSD is an abbreviation for Electron Back Scatter Diffraction (Electron Backscatter Diffraction). Reflected Electron Kikuchi Line Diffraction (Kikuchi pattern) generated when a sample is irradiated with an electron beam in a Scanning Electron Microscope (SEM). This is the crystal orientation analysis technology used.
In this embodiment, a sample area of 50,000 square μm or more is scanned in a 0.2 μm step, and the orientation is analyzed.
The area ratio is calculated by dividing (dividing) the area of the region whose deviation angle from the ideal orientation is within 13 ° by the total measurement area.
Regarding the deviation angle from the ideal orientation, the rotation angle was calculated around the common rotation axis, and was taken as the deviation angle.

FIG. 7 is a diagram illustrating an example of an orientation whose deviation angle from the RDW orientation is within 13 °.
In FIG. 7, azimuths within 13 ° are shown with respect to the rotation axes of (001), (101), and (111), but the rotation angle with the RDW azimuth was calculated for every rotation axis. The rotation axis that can be expressed at the smallest angle is adopted.
The information obtained in the azimuth analysis by EBSD includes azimuth information up to a depth of several tens of nanometers at which the electron beam penetrates into the sample. It was described as an area ratio. The orientation distribution was measured from the plate surface.

[Process for controlling crystal orientation]
The manufacturing process for controlling to the crystal orientation in which effectiveness was found in embodiment of this invention is shown.
In addition, as described above, the area ratio of the region where the surface irregularities of the striped pattern in the direction of 60 ° to 120 ° with respect to the rolling direction is 60% or more, and the RDW orientation { As long as the area ratio within 13 ° from the 012} <100> orientation is 15% or less, the manufacturing process is not limited thereto.

As a manufacturing process of the rolled copper foil 20 for controlling the crystal orientation, the first process ST1 to the 13th process ST13 are basic processes as shown in FIG.
That is, a melting process, a casting process, a homogenization heat treatment process, a hot rolling process, a water cooling process, a chamfering process, a first (intermediate) cold rolling process, a first intermediate annealing process, a second intermediate cold process, a second The manufacturing process is basically composed of an intermediate annealing process, a third intermediate cold process, a final annealing process, and a finish rolling process.

In general, the purpose of the intermediate annealing step is to make a material that is hardened by processing and difficult to further process by recrystallizing and softening the structure so that it can be processed.
The recrystallization temperature of the copper alloy is approximately 150 to 800 ° C. (here, less than 800 ° C.) although there are differences depending on the alloy.
In the embodiment of the present invention, the RDW orientation to be controlled low is the preferential growth orientation in recrystallization and tends to remain non-rotated even after rolling.
Therefore, it is necessary to reduce the RDW orientation in the structure in the final annealing in the twelfth step ST12.

According to the manufacturing method of the rolled copper foil 20 which concerns on this embodiment, in 2nd intermediate annealing of 10th process ST10, by making temperature increase rate 2 degrees C / sec or more and ultimate temperature to 800 degrees C or more, And found that control is possible.
The formation of the preferred orientation in the recrystallization process is thought to be affected by the difference in the recovery rate for each crystal orientation, but it does not give the time for the recrystallization precursor phenomenon by increasing the temperature rise rate, This is because preferential movement of specific grain boundaries is suppressed by increasing the temperature, and a random recrystallized structure is obtained.
A preferable range of the annealing rate is 5 ° C./second or more, and a more preferable range is 10 ° C./second or more. There is no particular upper limit, but the maximum is 200 ° C / sec.
A preferable range of the reached temperature is 870 ° C or higher, and a more preferable range is 950 ° C or higher. The upper limit is 1000 ° C. at which the high temperature brittleness of the material becomes significant.

  Note that it is not preferable to perform this randomized recrystallization heat treatment in the final annealing in the twelfth step ST12, since it causes cracks and cracks when the crystal grains are coarse. Therefore, the crystal grain size after the final annealing is preferably 30 μm or less.

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

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

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

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

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

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

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

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

It has been confirmed that the RDW orientation tends to be formed more as the alloy system contains more additive elements than in the pure copper system. This is because the rolling texture changes from a pure copper type to a brass type.
Therefore, the effect of the embodiment of the present invention becomes more remarkable as the concentration of the alloy becomes higher. That is, in applying the embodiment of the present invention, a preferable alloy system is a Cu-Ag system, and a more preferable alloy system is a Cu-Sn system, a Cu-Ni-Si system, or a Cu-Cr system.

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

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

[Method for producing rolled copper foil]
The Example of the manufacturing method of the rolled copper foil which concerns on this embodiment is linked | related with FIG. 3, and is demonstrated.
In the first step ST1, the raw material was melted in a high-frequency melting furnace, and the melted raw material was cast in the second step ST2 at a cooling rate of 0.1 to 100 ° C./second to obtain an ingot. The ingot contains the alloy components shown in Tables 2 to 6, and the remainder is formed of Cu and inevitable impurities.

In the third step ST3, the ingot obtained in the second step ST2 was subjected to a homogenization heat treatment at a temperature of 800 to 1030 ° C. for 5 minutes to 10 hours, and then subjected to hot rolling in the fourth step ST4.
After hot working in the fourth step ST4, water cooling was performed in the fifth step ST5, and chamfering was performed for removing the oxide scale in the sixth step ST6.
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, the second intermediate annealing is performed in the tenth step ST10, the third intermediate cold rolling is performed in the eleventh step ST11, the final annealing is performed in the twelfth step ST12, and the finish rolling is performed in the thirteenth step ST13. Produced a rolled foil of 12 μm or less.

Each rolling process of 1st (intermediate) cold rolling of 7th process ST7, 2nd intermediate cold rolling of 9th process ST9, 3rd intermediate cold rolling of 11th process ST11, and finish rolling of 13th process ST13 Was carried out at a plate thickness reduction rate of 66 to 99%.
The annealing process of the first intermediate annealing in the eighth step ST8 and the final annealing in the twelfth step ST12 was held at a normal recrystallization temperature of 300 ° C. or higher and lower than 800 ° C. for 3 seconds to 10 hours.
However, the second intermediate annealing in the tenth step ST10 was performed under the conditions of a temperature increase rate of 2 ° C./second or more and an ultimate temperature of 800 ° C. or more and 1000 ° C. or less.
After each heat treatment and rolling, acid cleaning and surface polishing were performed according to the state of oxidation and roughness of the material surface, and correction with a tension leveler was performed according to the shape.
An example of the manufacturing method according to the present embodiment is referred to as a process A.

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

[Step E]
In step E, the temperature increase rate of the second intermediate annealing in the tenth step ST10 is set to 0.2 to 1.8 ° C./second, the ultimate temperature is set to 300 ° C. or higher and lower than 800 ° C. Same as above.

[Step F]
In the process F, the temperature increase rate of the second intermediate annealing in the tenth process ST10 is set to 0.2 to 1.8 ° C./second, the ultimate temperature is set to 800 to 1000 ° C., and other processes are the same as those in the process A. .

[Step G]
In the step G, the temperature increase rate of the second intermediate annealing in the tenth step ST10 is set to 2 ° C./second or higher, the ultimate temperature is set to 300 ° C. or higher and lower than 800 ° C., and the other steps are the same as the step A.

[Step H] (Construction method described in JP 2000-328159 A)
Process H is melted in the atmosphere under a charcoal coating in an electric furnace, melts an ingot of 50 mm × 80 mm × 180 mm, hot-rolls it into a slab having a thickness of 15 mm, and further heats at 820 ° C. It was cold-rolled and finished with a plate material having a thickness of 3.3 mm, followed by water cooling.
About these plate materials, after cold rolling to a thickness of 1.2 mm, intermediate annealing at a furnace temperature of 750 ° C. × 20 S, cold rolling to a thickness of 0.4 mm, and then intermediate annealing at a furnace temperature of 700 ° C. × 20 S Then, after cold rolling to a thickness of 0.2 mm, intermediate annealing at a furnace temperature of 650 ° C. × 20 S was performed, and further cold rolling was performed to produce a copper alloy foil having a thickness of 10 μm.
This process H is disclosed by patent document 4 (Unexamined-Japanese-Patent No. 2000-328159).

[Step I] (Construction method described in JP-A-11-310864)
In step I, the ingot is hot-rolled at a finish temperature of 500 ° C. after the soaking process, and then the conditions of each step of cold rolling and final annealing governing the crystal orientation of the copper foil are determined according to the conditions before the final annealing. The rolling rate was 10 to 95%, the final annealing temperature was 400 ° C or higher, and the cold rolling rate after the final annealing was 10 to 99%.
This process I is disclosed in Patent Document 5 (Japanese Patent Laid-Open No. 11-310864).

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

[Area ratio of striped uneven area: AR1]
The area ratio AR1 of the striped uneven area is blackened in the optical micrograph in the area where the striped unevenness in the direction of 60 ° to 120 ° with respect to the rolling direction is confirmed, and then image processing is performed to obtain the second floor. The black area was divided by the total area to obtain the area ratio. The area of the visual field was 200,000 square μm, and the average of three field measurements was measured.

[RDW orientation area ratio: AR2]
RDW azimuth | direction area ratio AR2 was measured from the rolling surface by the method mentioned above by the EBSD method mentioned above. If the pattern was not clear due to the thick work-affected layer on the rolled surface, only the outermost layer was dissolved by chemical polishing and measured.

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

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

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

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

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

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

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

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

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

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

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

Tables 2 to 6 show the evaluation results.
Below, as shown in the evaluation results for each table, the area ratio of the striped uneven region where the surface unevenness of the striped pattern in the direction of 60 ° to 120 ° with respect to the rolling direction defined in the embodiment of the present invention is seen. When AR1 is 60% or more and the RDW orientation area ratio AR2 within 13 ° from the RDW orientation {012} <100> orientation in the surface crystal orientation satisfies 15% or less, the characteristics in battery evaluation Was good. On the other hand, the comparative example manufactured by the manufacturing steps E to I did not satisfy the area ratio AR1 and the RDW orientation area ratio AR2 of the striped uneven region, and the battery evaluation result was inferior.

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

Table 2 shows the evaluation results of the Cu— (Cr, Zr) -based copper alloy.
Examples 1-1 to 1-8 manufactured by manufacturing process A as rolled copper foil (this example) according to this embodiment, Reference Example 1-11 manufactured by manufacturing process A, and manufacturing processes E, F, and G , H and I were evaluated for Comparative Examples 1-21 to 1-25 manufactured.

Examples 1-1 to 1-7 and Comparative Examples 1-21 to 1-25 satisfy the condition that the sum of the main components Cr and Zr is 0.01 to 0.9 mass%, and the auxiliary additive components Sn and Zn When Si, Mn, and Mg are contained, the total satisfies the condition of 0.01 to 0.45 mass%.
However, Example 1-6 contains 0.52 mass% of the total amount of auxiliary additive components, and slightly exceeds the condition of 0.01 to 0.45 mass% in total of the auxiliary additive components.
Reference Example 1-11 does not satisfy the condition that the total of the main components Cr and Zr is 0.01 to 0.9 mass%.

In Examples 1-1 to 1-8, the striped uneven region area ratio AR1 satisfies the condition of 60% or more.
In Examples 1-1 to 1-8, the RDW azimuth area ratio AR2 satisfies the condition of 15% or less.

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

In addition, as described above, Example 1-6 contained 0.52 mass% of the total amount of auxiliary additive components, and slightly exceeded the condition of 0.01 to 0.45 mass% in total of the auxiliary additive components. Since the result that the characteristic in the evaluation is good is obtained, it is presumed that the electric characteristic is greatly influenced by whether or not the content of the main component is within the range specified in the present embodiment. .
Examples 1-4 and 1-7 do not contain any secondary additive, but the battery evaluation is satisfactory.

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

As for Comparative Example 1-21, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 45%. In Comparative Example 1-21, the RDW orientation area ratio AR2 is 22% and does not satisfy the condition of 15% or less.
In Comparative Example 1-21, the initial charge capacity as battery evaluation 1 was as low as 342 mAh compared to 481 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 was also 36% of Example 1-1. It is 16% of less than half.
As described above, Comparative Example 1-21 is inferior to Examples in characteristics in battery evaluation.

This is not a manufacturing process A, but a manufacturing method in which the temperature increase rate of the second intermediate annealing in the tenth process ST10 is 0.2 to 1.8 ° C / second and the ultimate temperature is 300 ° C or higher and lower than 800 ° C. This is presumably due to the fact that it was manufactured by the process E.
That is, the temperature rise rate of the second intermediate annealing, which is the feature of this production method, is not set to a temperature rise rate that does not give the time for the recrystallization precursor phenomenon, and the preferential movement of specific grain boundaries is suppressed and randomized. In order to obtain the recrystallized structure, the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy. Therefore, the conditions of the striped uneven area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, As a result, it is assumed that the battery characteristics are low.

As for Comparative Example 1-22, striped uneven | corrugated area | region area ratio AR1 is 57%, and is not satisfying | fulfilling 60% or more of conditions. As for Comparative Example 1-22, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 16%.
In Comparative Example 1-22, the initial charge capacity as battery evaluation 1 was as low as 385 mAh compared to 481 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 was also 36% of Example 1-1. It is 13% of less than half.
Thus, Comparative Example 1-22 is inferior to the present example in battery evaluation characteristics.

This is a characteristic of the present manufacturing method (step A), and in the second intermediate annealing of the tenth step ST10, the temperature rising rate is not increased so as not to give the time for the recrystallization precursor phenomenon. It is assumed that it is caused by the fact that the temperature is set to 8 ° C / second.
That is, in the second intermediate annealing, which is a feature of the present manufacturing method (step A), the ultimate temperature of the copper alloy is set to the recrystallization temperature in order to suppress the preferential movement of specific grain boundaries and obtain a randomized recrystallized structure. Even if the temperature is higher than the upper limit, it is set to 0.2 to 1.8 ° C./second without increasing the rate of temperature increase in the second intermediate annealing, so that the striped uneven region area ratio AR1 and the RDW orientation area ratio It is presumed that the condition of AR2 cannot be satisfied, and as a result, the battery characteristics are low.

As for Comparative Example 1-23, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 52%. In Comparative Example 1-23, the RDW orientation area ratio AR2 is 17% and does not satisfy the condition of 15% or less.
In Comparative Example 1-23, the initial charge capacity as battery evaluation 1 is as low as 372 mAh compared to 481 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 is also 36% of Example 1-1. It is 16% of less than half.
Thus, Comparative Example 1-23 is inferior to the Examples in the battery evaluation characteristics.

This is not a manufacturing process A, but a characteristic of the present manufacturing method (process A). In the second intermediate annealing of the tenth process ST10, a preferential movement of a specific grain boundary is suppressed, and a randomized recrystallized structure is formed. In order to obtain this, it is presumed that the ultimate temperature is not higher than the upper limit of the recrystallization temperature of the copper alloy but is set to a normal temperature of 300 ° C. or higher and lower than 800 ° C.
That is, in the second intermediate annealing that is a feature of the present manufacturing method (step A), even if the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, the specific movement of specific grain boundaries is suppressed, Since the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure, the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 can be satisfied. Therefore, it is presumed that the battery characteristics are low.

As for Comparative Example 1-24, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 51%. As for Comparative Example 1-24, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 18%.
In Comparative Example 1-24, the initial charge capacity as battery evaluation 1 is as low as 362 mAh compared to 481 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 is also 36% of Example 1-1. It is 17% of less than half.
Thus, Comparative Example 1-24 is inferior to the Examples in the battery evaluation characteristics.

In order to obtain a random recrystallized structure by suppressing the preferential movement of specific grain boundaries in the final second intermediate annealing, which is the feature of the present manufacturing method (step A), not the manufacturing step A. This is presumably because the ultimate temperature is not higher than the upper limit of the recrystallization temperature of the copper alloy.
That is, in the final intermediate annealing, which is a feature of the present manufacturing method (step A), the preferential movement of specific grain boundaries is suppressed, and the ultimate temperature is set to the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure. Since the temperature is not higher than the upper limit, it is presumed that the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, and the battery characteristics are lowered.

As for Comparative Example 1-25, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 48%. In Comparative Example 1-25, the RDW orientation area ratio AR2 is 19% and does not satisfy the condition of 15% or less.
In Comparative Example 1-25, the initial charge capacity as battery evaluation 1 is as low as 362 mAh as compared with 481 mAh in Example 1-1, and the maintenance rate as battery evaluation 2 is also 36% of Example 1-1. Lower 21%.
In Comparative Example 1-25, the characteristics in battery evaluation are inferior to those of the examples.

This is a feature of the present production method (Step A), and before the final annealing, the temperature rise rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a feature of the present production method (Step A), In addition, in order to suppress the preferential movement of specific grain boundaries and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that
That is, before the final annealing, which is a characteristic of the present manufacturing method, the temperature rising rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a characteristic of the present manufacturing method (Step A), and a specific grain boundary In order to suppress the preferential movement of copper and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that the conditions of AR1 and RDW azimuth area ratio AR2 cannot be satisfied, and as a result, the battery characteristics are low.

Table 3 shows the evaluation results of the Cu-Ag copper alloy.
Examples 2-1 to 2-5 manufactured by manufacturing process A as rolled copper foil (this example) according to this embodiment, Reference Example 2-11 manufactured by manufacturing process A, and manufacturing processes G, H, and I Evaluation was performed on Comparative Examples 2-21 to 2-23 manufactured in (1).

In Examples 2-1 to 2-5 and Comparative Examples 2-21 to 2-23, the total amount of the main component Ag satisfies the condition of 0.01 to 0.9 mass%, and the auxiliary additive components Sn, Zn, Si When Mn and Mg are contained, the total satisfies the condition of 0.01 to 0.45 mass%.
However, Reference Example 2-11 does not satisfy the condition that the total amount of the main component Ag is 0.01 to 0.9 mass%.

In Examples 2-1 to 2-5, the striped uneven area area ratio AR1 satisfies the condition of 60% or more.
In Examples 2-1 to 2-5, the RDW orientation area ratio AR2 satisfies the condition of 15% or less.

  In Examples 2-1 to 2-5, as can be seen from the initial charge capacity as the battery evaluation 1 and the retention rate as the battery evaluation 2, the characteristics in the battery evaluation were good.

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

As for Comparative Example 2-21, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 51%. As for Comparative Example 2-21, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 20%.
In Comparative Example 2-21, the initial charge capacity as battery evaluation 1 is as low as 355 mAh compared to 432 mAh in Example 2-2, and the maintenance rate as battery evaluation 2 is also 31% of Example 2-2. It is 15% of less than half.
Thus, Comparative Example 2-21 has inferior characteristics in battery evaluation as compared with Examples.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing that is a feature of the present manufacturing method (step A), even if the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, the specific movement of specific grain boundaries is suppressed, Since the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure, the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 can be satisfied. Therefore, it is presumed that the battery characteristics are low.

As for Comparative Example 2-22, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 53%. As for Comparative Example 2-22, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 18%.
In Comparative Example 2-22, the initial charge capacity as battery evaluation 1 is 361 mAh lower than 432 mAh in Example 2-2 of this example, and the maintenance rate as battery evaluation 2 is also in Example 2-2. 13%, which is less than half of 31%.
Thus, Comparative Example 2-22 is inferior to this example in battery evaluation characteristics.

This is presumed to be the same reason as for Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the final intermediate annealing, which is a feature of the present manufacturing method (step A), the preferential movement of specific grain boundaries is suppressed, and the ultimate temperature is set to the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure. Since the temperature is not higher than the upper limit, it is presumed that the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, and the battery characteristics are lowered.

As for Comparative Example 2-23, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 45%. As for Comparative Example 2-23, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 20%.
In Comparative Example 2-23, the initial charge capacity as battery evaluation 1 is 355 mAh lower than 432 mAh in Example 2-2, and the maintenance rate as battery evaluation 2 is also half of 31% of Example 2-2. 11% of the following.
Thus, Comparative Example 2-23 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, before the final annealing, which is a characteristic of the present manufacturing method, the temperature rising rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a characteristic of the present manufacturing method (Step A), and a specific grain boundary In order to suppress the preferential movement of copper and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that the conditions of AR1 and RDW azimuth area ratio AR2 cannot be satisfied, and as a result, the battery characteristics are low.

Table 4 shows the evaluation results of the Cu—Sn based copper alloy.
Examples 3-1 to 3-6 manufactured by manufacturing process A as rolled copper foil (this example) according to the present embodiment, Reference Example 3-11 manufactured by manufacturing process A, and manufacturing processes G, H, I Evaluation was performed on Comparative Examples 3-21 to 3-23 manufactured in (1).

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

In Examples 3-1 to 3-6, the striped uneven region area ratio AR1 satisfies the condition of 60% or more.
In Examples 3-1 to 3-6, the RDW orientation area ratio AR2 satisfies the condition of 15% or less.

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

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

As for Comparative Example 3-21, striped uneven | corrugated area | region area ratio AR1 is 57%, and is not satisfying | fulfilling 60% or more of conditions. As for Comparative Example 3-21, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 18%.
In Comparative Example 3-21, the initial charge capacity as the battery evaluation 1 is 375 mAh lower than the 441 mAh of the Example 3-1, and the maintenance rate as the battery evaluation 2 is also 31% of the Example 3-1. It is 15% of less than half.
Thus, Comparative Example 3-21 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing that is a feature of the present manufacturing method (step A), even if the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, the specific movement of specific grain boundaries is suppressed, Since the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure, the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 can be satisfied. Therefore, it is presumed that the battery characteristics are low.

As for Comparative Example 3-22, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 51%. As for Comparative Example 3-22, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 22%.
In Comparative Example 3-22, the initial charge capacity as battery evaluation 1 is as low as 375 mAh compared to 441 mAh in Example 3-1, and the maintenance rate as battery evaluation 2 is also 31% of Example 3-1. It is 13% of less than half.
Thus, Comparative Example 3-22 has inferior characteristics in battery evaluation to the Examples.

This is presumed to be the same reason as for Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the final intermediate annealing, which is a feature of the present manufacturing method (step A), the preferential movement of specific grain boundaries is suppressed, and the ultimate temperature is set to the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure. Since the temperature is not higher than the upper limit, it is presumed that the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, and the battery characteristics are lowered.

As for Comparative Example 3-23, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 40%. As for Comparative Example 3-23, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 23%.
In Comparative Example 3-23, the initial charge capacity as battery evaluation 1 is as low as 340 mAh compared to 441 mAh in Example 3-1, and the maintenance rate as battery evaluation 2 is also half of 31% of Example 3-1. 11% of the following.
Thus, Comparative Example 3-23 is inferior to Examples in characteristics in battery evaluation.

-This is presumed to be the same reason as Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu- (Cr, Zr) -based copper alloy in Table 2.
That is, before the final annealing, which is a characteristic of the present manufacturing method, the temperature rising rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a characteristic of the present manufacturing method (Step A), and a specific grain boundary In order to suppress the preferential movement of copper and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that the conditions of AR1 and RDW azimuth area ratio AR2 cannot be satisfied, and as a result, the battery characteristics are low.

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

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

In Examples 4-1 to 4-8, the striped uneven region area ratio AR1 satisfies the condition of 60% or more.
In Examples 4-1 to 4-8, the RDW orientation area ratio AR2 satisfies the condition of 15% or less.

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

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

In Comparative Example 4-21, the striped uneven region area ratio AR1 is 54% and does not satisfy the condition of 60% or more. As for Comparative Example 4-21, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 17%.
In Comparative Example 4-21, the initial charge capacity as the battery evaluation 1 is 381 mAh lower than the 441 mAh in the Example 4-1, and the maintenance rate as the battery evaluation 2 is also 32% of the Example 4-1. It is 14% of less than half.
Thus, Comparative Example 4-21 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing that is a feature of the present manufacturing method (step A), even if the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, the specific movement of specific grain boundaries is suppressed, Since the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure, the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 can be satisfied. Therefore, it is presumed that the battery characteristics are low.

As for Comparative Example 4-22, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 49%. As for Comparative Example 4-22, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 21%.
In Comparative Example 4-22, the initial charge capacity as battery evaluation 1 is as low as 351 mAh compared to 441 mAh in Example 4-1 of this example, and the maintenance rate as battery evaluation 2 is also Example 4-1 13%, which is less than half of 32%.
Thus, Comparative Example 4-22 has inferior characteristics in battery evaluation to the Examples.

This is presumed to be the same reason as for Comparative Example 1-22 shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing, which is a feature of the present manufacturing method (step A), the ultimate temperature of the copper alloy is set to the recrystallization temperature in order to suppress the preferential movement of specific grain boundaries and obtain a randomized recrystallized structure. Even if the temperature is higher than the upper limit, it is set to 0.2 to 1.8 ° C./second without increasing the rate of temperature increase in the second intermediate annealing, so that the striped uneven region area ratio AR1 and the RDW orientation area ratio It is presumed that the condition of AR2 cannot be satisfied, and as a result, the battery characteristics are low.

As for Comparative Example 4-23, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 43%. As for Comparative Example 4-23, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 24%.
In Comparative Example 4-23, the initial charge capacity as battery evaluation 1 is as low as 326 mAh compared to 441 mAh in Example 4-1 of this example, and the maintenance rate as battery evaluation 2 is also Example 4-1. 11%, which is less than half of 32%.
Thus, Comparative Example 4-23 is inferior to Examples in characteristics in battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, before the final annealing, which is a characteristic of the present manufacturing method, the temperature rising rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a characteristic of the present manufacturing method (Step A), and a specific grain boundary In order to suppress the preferential movement of copper and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that the conditions of AR1 and RDW azimuth area ratio AR2 cannot be satisfied, and as a result, the battery characteristics are low.

Table 6 shows the pure copper-based evaluation results.
Examples 5-1 to 5-2 manufactured by the manufacturing process A as a rolled copper foil (this example) according to the present embodiment, and Comparative Example 5-21 manufactured by the manufacturing processes E, F, G, H, and I. Evaluation was made for ˜5-25.

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

In Examples 5-1 and 5-2, the striped uneven region area ratio AR1 satisfies the condition of 60% or more.
In Examples 5-1 and 5-2 of this example, the RDW orientation area ratio AR2 satisfies the condition of 15% or less.

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

As for Comparative Example 5-21, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 51%. As for Comparative Example 5-21, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 16%.
In Comparative Example 5-21, the initial charge capacity as battery evaluation 1 is 385 mAh lower than 451 mAh in Example 5-1, and the maintenance rate as battery evaluation 2 is also 27% of Example 5-1. It is 9% of 1/3.
Thus, Comparative Example 5-21 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-21 manufactured in the manufacturing process E shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, the temperature rise rate of the second intermediate annealing, which is the feature of this production method, is not set to a temperature rise rate that does not give the time for the recrystallization precursor phenomenon, and the preferential movement of specific grain boundaries is suppressed and randomized. In order to obtain the recrystallized structure, the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy. Therefore, the conditions of the striped uneven area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, As a result, it is assumed that the battery characteristics are low.

As for Comparative Example 5-22, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 57%. As for Comparative Example 5-22, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 17%.
In Comparative Example 5-22, the initial charge capacity as battery evaluation 1 is as low as 375 mAh compared to 451 mAh in Example 5-1, and the maintenance rate as battery evaluation 2 is also 27% of Example 5-1. It is 8% of 1/3 or less.
Thus, Comparative Example 5-22 is inferior to the Examples in terms of battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-22 manufactured in Manufacturing Process F shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing, which is a feature of the present manufacturing method (step A), the ultimate temperature of the copper alloy is set to the recrystallization temperature in order to suppress the preferential movement of specific grain boundaries and obtain a randomized recrystallized structure. Even if the temperature is higher than the upper limit, it is set to 0.2 to 1.8 ° C./second without increasing the rate of temperature increase in the second intermediate annealing, so that the striped uneven region area ratio AR1 and the RDW orientation area ratio It is presumed that the condition of AR2 cannot be satisfied, and as a result, the battery characteristics are low.

As for Comparative Example 5-23, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 43%. As for Comparative Example 5-23, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 24%.
In Comparative Example 5-23, the initial charge capacity as the battery evaluation 1 is as low as 355 mAh compared to 451 mAh in the Example 5-1, and the maintenance rate as the battery evaluation 2 is also 27% of the Example 5-1. It is 6% of 1/4 or less.
Thus, Comparative Example 5-23 has inferior characteristics in battery evaluation as compared with Examples.

This is presumed to be the same reason as for Comparative Example 1-23 manufactured in the manufacturing process G shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the second intermediate annealing that is a feature of the present manufacturing method (step A), even if the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, the specific movement of specific grain boundaries is suppressed, Since the ultimate temperature is not set higher than the upper limit of the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure, the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 can be satisfied. Therefore, it is presumed that the battery characteristics are low.

As for Comparative Example 5-24, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 55%. As for Comparative Example 5-24, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 19%.
In Comparative Example 5-24, the initial charge capacity as battery evaluation 1 was as low as 365 mAh compared to 451 mAh in Example 5-1, and the maintenance rate as battery evaluation 2 was also 27% of Example 5-1. It is 9% of 1/3.
Thus, Comparative Example 5-24 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as that of Comparative Example 1-24 manufactured in the manufacturing process H shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, in the final intermediate annealing, which is a feature of the present manufacturing method (step A), the preferential movement of specific grain boundaries is suppressed, and the ultimate temperature is set to the recrystallization temperature of the copper alloy in order to obtain a randomized recrystallized structure. Since the temperature is not higher than the upper limit, it is presumed that the conditions of the striped uneven region area ratio AR1 and the RDW orientation area ratio AR2 cannot be satisfied, and the battery characteristics are lowered.

As for Comparative Example 5-25, striped uneven | corrugated area | region area ratio AR1 is not satisfying | fulfilling 60% or more of conditions at 46%. As for Comparative Example 5-25, RDW azimuth | direction area ratio AR2 is not satisfying | fulfilling 15% or less of conditions at 17%.
In Comparative Example 5-25, the initial charge capacity as battery evaluation 1 is as low as 370 mAh compared to 451 mAh in Example 5-1, and the maintenance rate as battery evaluation 2 is also 27% of Example 5-1. It is 6% of 1/4 or less.
Thus, Comparative Example 5-25 is inferior to the Examples in the battery evaluation.

This is presumed to be the same reason as for Comparative Example 1-25 manufactured in Manufacturing Process I shown in the evaluation results of the Cu— (Cr, Zr) -based copper alloy in Table 2.
That is, before the final annealing, which is a characteristic of the present manufacturing method, the temperature rising rate is increased so as not to give the time for the recrystallization precursor phenomenon, which is a characteristic of the present manufacturing method (Step A), and a specific grain boundary In order to suppress the preferential movement of copper and to obtain a randomized recrystallized structure, the second intermediate annealing in which the ultimate temperature is higher than the upper limit of the recrystallization temperature of the copper alloy is not performed. It is presumed that the conditions of AR1 and RDW azimuth area ratio AR2 cannot be satisfied, and as a result, the battery characteristics are low.

  As described above, the area ratio AR1 of the striped uneven region where the surface unevenness of the striped pattern in the direction of 60 ° to 120 ° with respect to the rolling direction defined in the embodiment of the present invention is 60% or more. When the RDW orientation area ratio AR2 within 13 ° from the RDW orientation {012} <100> orientation in the surface crystal orientation satisfies 15% or less, the characteristics in battery evaluation were good.

Further, in the second intermediate annealing in the method for manufacturing rolled copper foil according to the present embodiment (manufacturing step A), the rate of temperature rise is increased so as not to give the time for the recrystallization precursor phenomenon, and priority movement of specific grain boundaries is performed. In order to obtain a random recrystallized structure, the area ratio AR1 of the striped uneven region and the RDW orientation area ratio AR2 are defined by setting the reached temperature higher than the upper limit of the recrystallization temperature of the copper alloy. The conditions were satisfied and the characteristics in battery evaluation were good.
On the other hand, in the comparative example manufactured in the manufacturing steps E to I, the area ratio AR1 and the RDW azimuth area ratio AR2 of the striped uneven region did not satisfy the prescribed conditions, and the battery evaluation results were inferior.
Moreover, it can be said that the alloy system of Table 2-Table 5 shows a favorable battery characteristic with respect to the pure copper system shown in Table 6.

  According to the present embodiment, a roughened plated surface having uniform unevenness is formed, and the adhesion between the current collector and the active material is improved. Therefore, the current collection during the production process and in use of a product such as a battery The separation of the belt and the active material is prevented. And while making the initial discharge capacity of a battery favorable, the fall of the discharge capacity after repeating the cycle of charging / discharging can be prevented, and the high functionalization of a secondary battery can be implement | achieved.

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

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

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

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

Claims (13)

A rolled copper foil made of copper or a copper alloy formed by rolling,
In the crystal orientation of the surface, the area ratio within 13 ° from the RDW orientation {012} <100> orientation is 15% or less.
Rolled copper foil for secondary battery current collector. The area ratio of the region where the surface irregularities of the striped pattern in the direction of 60 ° to 120 ° with respect to the rolling direction is 60% or more,
A rolled copper foil for a secondary battery current collector according to claim 1. A Cu— (Cr, Zr) -based copper alloy containing at least one of Cr and Zr as a main component, and a total of at least one of Cr and Zr as main components is 0.01 to 0.9 mass%. contains,
The rolled copper foil for secondary battery collectors of Claim 1 or 2. Containing at least one of Sn, Zn, Si, Mn, and Mg as sub-addition components in a total of 0.01 to 0.45 mass%,
A rolled copper foil for a secondary battery current collector according to claim 3. A Cu-Ag based copper alloy containing Ag as a main component, containing 0.01 to 0.9 mass% of Ag as a main component in total.
The rolled copper foil for secondary battery collectors of Claim 1 or 2. Containing at least one of Sn, Zn, Si, Mn, and Mg as sub-addition components in a total of 0.01 to 0.45 mass%,
A rolled copper foil for a secondary battery current collector according to claim 5. A Cu-Sn based copper alloy containing Sn as a main component, containing 0.01 to 4.9 mass% of Sn as a main component in total.
The rolled copper foil for secondary battery collectors of Claim 1 or 2. 0.01-0.45 mass% in total containing at least one kind from Zn, Si, P, and Mg as sub-addition components,
The rolled copper foil for a secondary battery current collector according to claim 7. A Cu—Ni—Si based copper alloy containing Ni and Si as main components, and containing 1.4 to 4.8 mass% of Ni as a main component and 0.2 to 1.3 mass% of Si,
The rolled copper foil for secondary battery collectors of Claim 1 or 2. 0.005 to 0.9 mass% in total containing at least one of Sn, Zn, Mn, Mg, and Co, which are sub-addition components,
A rolled copper foil for a secondary battery current collector according to claim 9. It is a pure copper system containing oxygen, and the oxygen amount is 2 to 200 ppm
The rolled copper foil for secondary battery collectors of Claim 1 or 2. The remainder excluding the main component, or the remainder excluding the main component and the auxiliary additive component is formed by inevitable impurities.
The rolled copper foil for secondary battery electrical power collectors in any one of Claims 3-11. It is a manufacturing method of the rolled copper foil which manufactures the rolled copper foil for secondary battery collectors in any one of Claims 1-12,
A melting step for melting the raw materials;
A casting process for casting the melted raw material;
A homogenized heat treatment step of performing a homogenized heat treatment at 800 to 1030 ° C. for 5 minutes to 10 hours on the material to be rolled obtained by casting,
After the homogenization heat treatment step, a hot rolling step in which the material to be rolled is heated to a recrystallization temperature and hot rolled,
After the hot rolling step, a first intermediate cold rolling step for performing cold rolling through a water cooling and a chamfering step;
Following the first intermediate cold rolling step, a first intermediate annealing step of annealing at 300 to 800 ° C for 3 seconds to 10 hours,
Following the first intermediate annealing step, a second intermediate cold rolling step for performing cold rolling,
Following the second intermediate cold rolling step, a second intermediate annealing step in which annealing is performed at a temperature increase rate of 2 ° C / second or more and an ultimate temperature of 800 to 1000 ° C,
A third intermediate cold rolling step for performing cold rolling subsequent to the second intermediate annealing step;
A final annealing step of performing annealing at 300 to 800 ° C. for 3 seconds to 10 hours after the third intermediate cold rolling step, and a method for producing a rolled copper foil for a secondary battery current collector.

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