Method for manufacturing an electrode

Abstract

To provide a manufacturing method of an electrode capable of uniformizing an elongation rate in an uncoated part.SOLUTION: A manufacturing method of an electrode comprises: a precursor sheet preparation step of preparing a precursor sheet including a metal foil having a longitudinal direction in a first direction, and a coated part and an uncoated part arranged on the metal foil; a coated part pressing step of pressing the coated part in a thickness direction while transporting the precursor sheet in the first direction; and an uncoated part pressing step of pressing the uncoated part in the thickness direction while transporting the precursor sheet in the first direction before or after the coated part pressing step. The coated part contains an electrode material including at least an active substance, and the uncoated part does not contain the electrode material and is arranged at an end part of the coated part in a direction orthogonal to the first direction. In the uncoated part pressing step, the uncoated part is roll-pressed using a pair of elastic rolls having a shaft body and an elastic body covering the shaft body, and at least one of (i) compressive force and (ii) a gap between the pair of elastic rolls is adjusted according to a transportation speed so as to obtain constant deformation force applied to the uncoated part.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The present disclosure relates to a method for manufacturing an electrode.

Background Art

[0002] As a method for manufacturing an electrode, a method of rolling a sheet obtained by applying an electrode mixture on a long metal foil is known. For example, Patent Document 1 discloses a pressing method for a battery electrode having a coated portion coated with an electrode active material and an uncoated portion not coated with the electrode active material.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] As described above, when pressing a sheet having a coated portion and an uncoated portion, the coated portion and the uncoated portion may be individually pressed to adjust the elongation difference so that wrinkles do not occur. In addition, when pressing the uncoated portion, the uncoated portion may be roll-pressed using an elastic roll so that breakage does not occur.

[0005] The present inventors have found that when using an elastic roll, a difference may occur in the elongation rate of the uncoated portion depending on the conveyance speed in roll pressing. When a difference occurs in the elongation rate of the uncoated portion, a reduction in yield due to non-uniform elongation rate is likely to occur. The present disclosure has been made in view of the above circumstances, and the main object thereof is to provide a method for manufacturing an electrode capable of equalizing the elongation rate in the uncoated portion.

Means for Solving the Problems

[0006] [1] Prepare a precursor sheet having a metal foil with a longitudinal direction in a first direction, and a coated portion and an uncoated portion disposed on the metal foil. A preparation step, while transporting the precursor sheet in the first direction, press the coated portion in the thickness direction. A coated portion pressing step, before or after the coated portion pressing step, while transporting the precursor sheet in the first direction, press the uncoated portion in the thickness direction. An uncoated portion pressing step, wherein the coated portion contains an electrode material containing at least an active material, the uncoated portion does not contain the electrode material, and is disposed at an end of the coated portion in a direction orthogonal to the first direction. In the uncoated portion pressing step, use a pair of elastic rolls having a shaft body and an elastic body covering the shaft body to apply a compressive force to press the uncoated portion in the thickness direction, and during the roll pressing, adjust at least one of (i) the compressive force and (ii) the gap between the pair of elastic rolls according to the transport speed so that the deformation force applied to the uncoated portion becomes constant. A method for manufacturing an electrode.

[0007] [2] When adjusting the compressive force, let the first transport speed be V 1 and the compressive force at the above V 1 be C 1 Let the reference transport speed be V B and the compressive force at the above V B be C B When the above V 1 is smaller than the above V B , make the above C 1 smaller than the above C B The method for manufacturing an electrode according to [1].

[0008] [3] When adjusting the compressive force, (i-A) corresponding to the behavior of the above V 1 increasing to the above V B , increase the above C 1 to the above C B and (i-B) corresponding to the behavior of the above V 1 decreasing from the above V B , the above C1 Reduce at least one of the above C B The method for manufacturing an electrode according to [2], which performs at least one of the above operations.

[0009] [4] When adjusting the gap between the pair of elastic rolls, the first conveyance speed is V 1 And the gap at the above V 1 Is G 1 The reference conveyance speed is V B And the gap at the above V B Is G B And the above V 1 Is less than the above V B In this case, the above G 1 Is in a state larger than the above G B The method for manufacturing an electrode according to [1].

[0010] [5] When adjusting the gap between the pair of elastic rolls, (ii-A) the above V 1 In response to the behavior of increasing up to the above V B The above G 1 Is reduced to the above G B And, (ii-B) the above V 1 In response to the behavior of decreasing from the above V B The above G 1 Is increased from the above G B The method for manufacturing an electrode according to [4], which performs at least one of the above operations.

Effect of the Invention

[0011] In the present disclosure, there is an effect that an electrode with a uniform elongation rate in the uncoated portion can be manufactured.

Brief Description of the Drawings

[0012]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Mode for Carrying Out the Invention

[0013] Hereinafter, the method for manufacturing an electrode in the present disclosure will be described in detail. Here, in this specification, when expressing the mode of arranging one member with respect to another member and simply writing "above", unless otherwise specified, it includes both the case of arranging another member directly above so as to be in contact with one member and the case of arranging another member above one member via another member.

[0014] FIG. 1 is a flowchart showing an example of a method for manufacturing an electrode according to the present disclosure. In FIG. 1, first, a precursor sheet having a metal foil having a longitudinal direction in a first direction and a coated portion and an uncoated portion disposed on the metal foil is prepared (preparation step). The coated portion contains an electrode material containing at least an active material. The uncoated portion does not contain the electrode material and is disposed at an end of the coated portion in a direction orthogonal to the first direction. Next, while conveying the precursor sheet in the first direction, the coated portion is pressed in the thickness direction (coated portion pressing step). Then, while conveying the precursor sheet in the first direction, the uncoated portion is pressed in the thickness direction (uncoated portion pressing step). In FIG. 1, the uncoated portion pressing step is performed after the coated portion pressing step, but it may be performed before the coated portion pressing step. Further, in the uncoated portion pressing step, while applying a compressive force for pressing the uncoated portion in the thickness direction using a pair of elastic rolls having a shaft body and an elastic body covering the shaft body, roll pressing is performed. During the roll pressing, at least one of (i) the compressive force and (ii) the gap between the pair of elastic rolls is adjusted according to the conveyance speed so that the deformation force applied to the uncoated portion becomes constant.

[0015] According to the present disclosure, since the uncoated portion is roll-pressed using a predetermined elastic roll and at least one of (i) the compressive force and (ii) the gap between the pair of elastic rolls is adjusted according to the conveyance speed so that the deformation force applied to the uncoated portion becomes constant during the roll pressing, an electrode with a uniform elongation rate in the uncoated portion can be manufactured. That is, by varying the roll gap or the roll pressure so as to be synchronized with the conveyance speed, an uncoated portion having a uniform elongation rate is formed regardless of the conveyance speed.

[0016] As a method for manufacturing an electrode, a method of pressing a precursor sheet in which an electrode mixture is coated on a metal foil (current collector foil) is known. Also, depending on the presence or absence of the electrode mixture, a difference in elongation rate occurs after pressing between the coated portion and the uncoated portion of the metal foil, and there is a risk that wrinkles may occur in the electrode. In this regard, as in Patent Document 1 described above, the coated portion and the uncoated portion are pressed individually to suppress the occurrence of wrinkles. Also, in the pressing of the uncoated portion (metal foil), a pair of elastic rolls may be used to perform roll pressing while applying a compressive force that presses in the thickness direction. By performing such roll pressing, it is possible to apply, to the uncoated portion, a deformation force resulting from the deformation of the elastic body together with the above-mentioned compressive force. Thereby, for example, breakage of the uncoated portion can be effectively prevented.

[0017] Here, generally, a hard tissue harder than the material of the metal foil is included as an inclusion in the metal foil. By including the hard tissue, for example, the strength of the metal foil can be increased. When a tensile force (horizontal force) for stretching the metal foil is applied, although the hard tissue does not deform, the surrounding metal foil that is softer than the hard tissue deforms. As a result, voids are formed around the hard tissue. And when a plurality of voids are connected to each other, breakage is likely to occur. On the other hand, in the present disclosure, a pair of elastic rolls are used to perform roll pressing while applying a compressive force that presses in the thickness direction. Thereby, it is considered that it is possible to suppress the generation of voids around the hard tissue by applying, to the uncoated portion, a deformation force resulting from the deformation of the elastic body together with the above-mentioned compressive force. The above-mentioned compressive force corresponds to a force in the thickness direction, and the above-mentioned deformation force corresponds to a force in a direction orthogonal to the thickness direction. That is, the above-mentioned deformation force acts in the same direction as the tensile force and is a force that stretches the metal foil in the same way as the tensile force.

[0018] In the present disclosure, as shown in FIG. 2(a), while applying a compressive force for pressing in the thickness direction to the uncoated portion 3 using a pair of elastic rolls 20A and 20B, roll pressing is performed. Here, as shown in FIG. 2(b), the conveyance speed in roll pressing, for example, increases from a stop to a processing speed (acceleration section), then is maintained at the processing speed (constant section), and then decreases from the acceleration speed to a stop (deceleration section). Further, since the amount of deformation of the elastic body 22 in the elastic roll 20 depends on the conveyance speed, in the acceleration section and the deceleration section, the elongation rate of the uncoated portion 3 is different from that in the constant section. Specifically, in the acceleration section and the deceleration section, since the deformation force applied to the uncoated portion is larger than that in the constant section, the uncoated portion 3 is likely to elongate. As a result, a decrease in yield due to a non-uniform elongation rate is likely to occur.

[0019] On the other hand, in the present disclosure, at least one of (i) the compressive force applied by the pair of elastic body rolls and (ii) the gap between the pair of elastic rolls is adjusted according to the conveyance speed so that the deformation force applied to the uncoated portion becomes constant. For example, in the acceleration section and the deceleration section, the compressive force applied by the pair of elastic body rolls is adjusted to be smaller than that in the constant section. Alternatively, in the acceleration section and the deceleration section, the gap between the pair of elastic rolls is adjusted to be larger than that in the constant section. Thereby, for example, the difference between the elongation rate of the uncoated portion in the acceleration section and the deceleration section and the elongation rate of the uncoated portion in the constant section becomes smaller, and the elongation rate in the uncoated portion can be made uniform.

[0020] 1. Preparation step The preparation step in the present disclosure is a step of preparing a precursor sheet having a metal foil having a longitudinal direction in a first direction, and a coated portion and an uncoated portion disposed on the metal foil.

[0021] FIG. 3 is a schematic plan view illustrating a precursor sheet prepared in the preparation step. As shown in FIG. 3, the precursor sheet 10 has a metal foil 1 having a longitudinal direction in a first direction D, a coated portion 2, and an uncoated portion 3.

[0022] Examples of the material of the metal foil include metals used as the material of the current collector of the battery. Details are described in "4. Electrodes". The thickness of the metal foil is, for example, 1 μm or more, and may be 10 μm or more. On the other hand, the thickness of the metal foil is, for example, 100 μm or less.

[0023] The coated portion of the precursor sheet contains an electrode material containing at least an active material. Further, the coated portion is disposed on the metal foil. The coated portion becomes an electrode layer through a coated portion pressing process described later.

[0024] The electrode material contains at least an active material. Further, the electrode material may contain at least one of a solid electrolyte, a conductive material, and a binder, if necessary. The active material, conductive material, and binder are described in "4. Electrodes".

[0025] In the thickness direction, the coated portion may be disposed only on the first surface of the metal foil, or may be disposed on both the first surface and the second surface opposite to the first surface.

[0026] The coated portion is preferably disposed along the first direction of the metal foil. Further, as shown in FIG. 3, the coated portion may be continuously disposed along the first direction D of the metal foil 1. On the other hand, the coated portion 1 may be intermittently disposed along the first direction D of the metal foil 1.

[0027] The thickness of the coated portion is not particularly limited and can be appropriately adjusted according to the desired electrode size. The thickness of the coated portion is, for example, 0.2 mm or more, may be 0.3 mm or more, and may be 0.5 mm or more. On the other hand, the thickness of the coated portion is, for example, 1.5 mm or less, may be 1.0 mm or less, and may be 0.6 mm or less.

[0028] The width of the coating section (the length in the direction perpendicular to the first direction of the metal foil) is not particularly limited and can be appropriately adjusted according to the desired electrode size. The ratio of the width of the coating section to the width of the metal foil can be, for example, 30% or more, may be 50% or more, and may be 70% or more. Also, the above ratio can be, for example, 90% or less, and may be 80% or less.

[0029] The uncoated section is disposed on the metal foil. Also, the uncoated section is usually disposed on the same surface as the surface of the metal foil on which the coating section is disposed. The uncoated section is, for example, a portion where the metal foil is exposed. As shown in FIG. 3, in the present disclosure, the uncoated section 3 is disposed at the end of the coating section 2 in the direction perpendicular to the first direction D of the metal foil 1.

[0030] The width of the uncoated section (the length in the direction perpendicular to the first direction of the metal foil) is not particularly limited and can be appropriately adjusted according to the desired electrode size. The ratio of the width of the uncoated section to the width of the metal foil can be, for example, 3% or more, and may be 5% or more. On the other hand, the above ratio can be, for example, 20% or less, and may be 10% or less.

[0031] The precursor sheet can be prepared, for example, by coating an electrode material containing a dispersion medium on a metal foil and drying it. Examples of the dispersion medium include organic solvents such as butyl butyrate, dibutyl ether, and heptane. The coating method of the electrode material is not particularly limited, and general coating methods can be mentioned. Also, the drying temperature is not particularly limited as long as it is a temperature at which the dispersion medium volatilizes.

[0032] The precursor sheet prepared in the preparation step may be, for example, a precursor sheet 10 having, in plan view, a stripe-like arrangement of one row of coating sections 2 and two rows of uncoated sections 3 disposed at both ends of the coating section 2, as shown in FIG. 3. Also, although not shown, the precursor sheet may be a sheet having, in plan view, N rows (N is an integer of 2 or more) of coating sections and uncoated sections disposed at both ends of each of the N rows of coating sections. In this case, the number of rows of the uncoated sections is N + 1 rows.

[0033] 2. Coating Section Pressing Step The coating part pressing process is a process of pressing the coating part in the thickness direction while conveying the precursor sheet in the first direction. The coating part pressing process may be performed before or after the uncoated part pressing process described later.

[0034] The method and conditions of the coating part pressing process are not particularly limited as long as the coating part can be pressed and stretched. Examples of the pressing method include a roll pressing method of roll-pressing the coating part. For example, while passing the precursor sheet between a pair of press rolls, the coating part can be pressed by pressing the press rolls against both surfaces of the precursor sheet in the thickness direction.

[0035] The compressive force in the coating part pressing process is not particularly limited, but it is preferably greater than the compressive force in the uncoated part pressing process described later. In the coating part of the precursor sheet, wrinkles may occur due to wetting by the electrode material (slurry) containing the dispersion medium. In order to stretch these wrinkles, a large stretching force is required.

[0036] 3. Uncoated part pressing process The uncoated part pressing process is a roll pressing process in which a pair of elastic rolls having a shaft body and an elastic body covering the shaft body are used to apply a compressive force to press the uncoated part in the thickness direction.

[0037] Here, the uncoated part pressing process will be described with reference to the drawings. Fig. 4(a) is a schematic side view of the uncoated part pressing process as seen from the width direction of the metal foil. Fig. 4(b) is a schematic plan view of Fig. 4(a) as seen from the thickness direction (vertical direction of the paper surface) of the precursor sheet. Fig. 4(c) is a schematic front view of Fig. 4(a) as seen from the conveyance direction (left-right direction of the paper surface) of the precursor sheet.

[0038] As shown in FIGS. 4(a) and 4(c), in the press process of the unpainted part, while the precursor sheet 10 is being conveyed in the first direction D, the precursor sheet 10 is passed between a pair of predetermined elastic rolls 20A and 20B, and a compressive force for pressing the elastic rolls 20A and 20B against both surfaces in the thickness direction of the precursor sheet is applied, and the unpainted part 3 (metal foil 1) is roll-pressed.

[0039] The elastic roll 20 generally has a roll shape in which an elastic body 22 is disposed around a shaft body 21. Also, as shown in FIG. 4(c), the elastic roll is a so-called stepped roll and can press only the unpainted part. If it has a roll shape, since the shaft body and the elastic body of the elastic roll are connected, compared with a sheet shape, deformation of the elastic body in the conveyance direction of the precursor sheet is suppressed. Further, the deformation direction of the elastic body is stabilized, and the generation of wrinkles can be more suppressed.

[0040] The material of the shaft body is not particularly limited, but a material having a larger compressive Young's modulus than the elastic body is preferable. Examples of the material of the shaft body include metals.

[0041] The elastic body is not particularly limited as long as it is a member having elasticity, and examples thereof include resins such as rubber and urethane.

[0042] The elastic body preferably has a predetermined compressive Young's modulus. The compressive Young's modulus is, for example, 11.1 MPa or more and 86.1 MPa or less. If the compressive Young's modulus is too low, the deformation amount of the elastic body becomes too large, and there is a risk that an excessive deformation force is applied to the unpainted part. As a result, there is a risk that breakage cannot be sufficiently suppressed. On the other hand, if the compressive Young's modulus is too high, the deformation amount of the elastic body becomes too small, and there is a risk that a sufficient deformation force cannot be applied to the unpainted part.

[0043] In the press process for the uncoated portion in the present disclosure, during the above roll press, at least one of (i) the compression force and (ii) the gap between the pair of elastic rolls is adjusted according to the conveyance speed so that the deformation force applied to the uncoated portion becomes constant. The "compression force" is the force with which a pair of elastic rolls presses against the precursor sheet in the thickness direction during roll pressing. On the other hand, the "gap between the pair of elastic rolls" is the distance between the pair of elastic rolls before sandwiching the precursor sheet (roll gap). The compression force and the roll gap are appropriately adjusted according to the settings of the roll press machine. Further, in the press process for the uncoated portion, the deformation force applied to the uncoated portion is preferably adjusted to be 0.5P or more and 1.0P or less when the deformation force in the above-mentioned constant section is P.

[0044] When adjusting the compression force, let the first conveyance speed be V 1 and the compression force at the above V 1 be C 1 Let the reference conveyance speed be V B and the compression force at the above V B be C B When the above V 1 is smaller than the above V B , it is preferable to make the above C 1 smaller than the above C B . When the first conveyance speed is smaller than the reference conveyance speed, making C 1 smaller than C B reduces the deformation amount of the elastic body and also reduces the deformation force applied to the uncoated portion. Thereby, an increase in the deformation force at low speed is suppressed, and an uncoated portion having a uniform elongation rate is formed.

[0045] Also, when adjusting the compression force, (i-A) corresponding to the behavior of increasing the above V 1 to the above V B , increasing the above C 1 to the above C B , and (i-B) corresponding to the behavior of decreasing the above V 1 from the above V B , decreasing the above C 1Reduce at least one of the above C B from, which is preferably performed. For example, as shown in FIG. 5(a), in the section where the first conveyance speed V 1 increases to the reference conveyance speed V B (the section of V 1 <V B on the left side of the figure, the acceleration section), in accordance with the behavior, C 1 is continuously increased to C B . Also, in the section where V 1 is equal to V B (the section of V 1 = V B in the center of the figure, the constant section), adjustment is made so that C 1 is equal to C B . Then, in the section where V 1 decreases from V B (the section of V 1 <V B on the right side of the figure, the deceleration section), in accordance with the behavior, C 1 is decreased from C B .

[0046] Also, when adjusting the compression force, only (i - A) may be performed, only (i - B) may be performed, or both (i - A) and (i - B) may be performed. The conveyance speeds (V B and V 1 ) are not particularly limited, but for example, they are 1 m / min or more and 100 m / min or less. Also, the compression forces (C B and C 1 ) are not particularly limited, but for example, they are 10 kgf / cm or more and 100 kgf / cm or less.

[0047] When adjusting the gap between a pair of elastic rolls, the first conveyance speed is V 1 , the gap at the above V 1 is G 1 , the reference conveyance speed is V B , and the gap at the above V B is G B . When the above V 1 is smaller than the above V B , the above G1 is preferably set to be larger than the above G B When the first conveyance speed is smaller than the reference conveyance speed, by setting G 1 to be larger than G B the amount of deformation of the elastic body is reduced, and the deformation force applied to the non-coated portion is also reduced. As a result, an increase in the deformation force due to the low speed is suppressed, and a non-coated portion having a uniform elongation rate is formed.

[0048] Further, when adjusting the gap between the pair of elastic rolls, (ii-A) corresponding to the behavior in which the above V 1 increases up to the above V B reducing the above G 1 to the above G B and, (ii-B) corresponding to the behavior in which the above V 1 decreases from the above V B increasing the above G 1 from the above G B at least one of them is preferably performed. For example, as shown in FIG. 5(b), in the section where the first conveyance speed V 1 increases up to the reference conveyance speed V B (the section of V 1 <V B on the left side of the figure, the acceleration section), in accordance with the behavior, G 1 is continuously reduced to G B . Also, in the section where V 1 and V B are equal (the section of V 1 =V B in the center of the figure, the constant section), adjustment is made such that G 1 becomes equal to G B . Then, in the section where the first conveyance speed V 1 decreases from the reference conveyance speed V B (the section of V 1 <V B on the right side of the figure, the deceleration section), in accordance with the behavior, G 1 is increased from G B .

[0049] Also, when adjusting the gap between a pair of elastic rolls, only (ii-A) may be performed, only (ii-B) may be performed, or both (ii-A) and (ii-B) may be performed. The gap (G B and G 1 ) is not particularly limited, but is, for example, 1 μm or more and 100 μm or less.

[0050] 4. Electrode In the electrode manufactured by the method of the present disclosure, an electrode layer is formed on at least one surface of a metal foil. Note that the electrode layer is a layer obtained by pressing the above coating portion. The electrode manufactured by the method of the present disclosure may be a positive electrode or a negative electrode. That is, the electrode layer may be a positive electrode layer or a negative electrode layer.

[0051] The metal foil typically functions as a current collector foil (current collector). That is, the metal foil may be a positive electrode current collector or a negative electrode current collector. When the metal foil is a positive electrode current collector, examples of the material of the metal foil include Al, SUS, and Ni. When the metal foil is a negative electrode current collector, examples of the material of the metal foil include Cu, SUS, and Ni.

[0052] The electrode layer contains at least an active material. When the electrode layer is a positive electrode layer, the active material is a positive electrode active material. Typical examples of the positive electrode active material include oxide active materials. Examples of the oxide active material include LiCoO 2 , LiMnO 2 , LiNiO 2 , LiVO 2 , LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O 2 and other rock salt layer type active materials, LiMn 2 O 4 , Li(Ni 0.5 Mn 1.5 )O 4 and other spinel type active materials, LiFePO 4 , LiMnPO 4 , LiNiPO 4 , LiCuPO 4Examples of the olivine type active materials include the like.

[0053] When the electrode layer is a negative electrode layer, the active material is a negative electrode active material. Examples of the negative electrode active material include carbon active materials, oxide active materials, and metal active materials. Examples of the carbon active materials include mesocarbon microbeads (MCMB), highly oriented pyrolytic graphite (HOPG), hard carbon, and soft carbon. Examples of the oxide active materials include Nb 2 O 5 、Li 4 Ti 5 O 12 and SiO. Examples of the metal active materials include In, Al, Si, and Sn.

[0054] In addition, the electrode layer may contain at least one of a conductive material and a binder as needed.

[0055] Examples of the conductive material include carbon materials, metal particles, and conductive polymers. Examples of the carbon materials include particulate carbon materials such as acetylene black (AB) and ketjen black (KB); fibrous carbon materials such as carbon fibers, carbon nanotubes (CNT), and carbon nanofibers (CNF). Examples of the binder include fluorine-containing binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), rubber-based binders such as butadiene rubber, and acrylic binders.

[0056] Examples of the use of the electrode in the present disclosure include, for example, lithium ion batteries. Further, the battery in the present disclosure may be a liquid-based battery in which the electrolyte layer contains a liquid-based electrolyte (electrolyte solution). Further, the use of the battery in the present disclosure is not particularly limited, and examples thereof include power sources for vehicles such as hybrid vehicles (HEV), plug-in hybrid vehicles (PHEV), battery electric vehicles (BEV), gasoline vehicles, and diesel vehicles. In particular, it is preferably used as a driving power source for a hybrid vehicle or a battery electric vehicle. Further, the battery in the present disclosure may be used as a power source for a moving body other than a vehicle (for example, a railway, a ship, an aircraft), or may be used as a power source for an electric product such as an information processing device.

[0057] Note that the present disclosure is not limited to the above-described embodiments. The above-described embodiments are examples, and any configuration that has substantially the same configuration as the technical idea described in the claims of the present disclosure and exhibits the same operational effects is included in the technical scope of the present disclosure.

Example

[0058] [Experimental Example 1] A precursor sheet as shown in FIG. 3 was prepared. Further, an elastic roll in which an elastic body was disposed on the surface of the shaft body was prepared. While conveying the precursor sheet in the first direction, the unpainted portion was pressed using the elastic roll. The pressing was performed with the compressive force of the elastic roll being 22 kgf / cm or 53 kgf / cm while changing the conveying speed of the precursor sheet. The results are shown in FIG. 6(a).

[0059] As shown in FIG. 6(a), it was confirmed that when the compressive force of the elastic roll was small or large, the elongation rate of the unpainted portion tended to decrease as the conveying speed increased. This is considered to be because the amount of deformation of the elastic body is larger (the deformation force applied to the unpainted portion is larger) as the conveying speed is lower, and the amount of deformation of the elastic body is smaller (the deformation force applied to the unpainted portion is smaller) as the conveying speed is higher. From this, it was confirmed that the elongation rate of the unpainted portion changes depending on the conveying speed of the precursor sheet.

[0060] [Experimental Example 2] Similar to Experimental Example 1, a precursor sheet and an elastic roll were prepared. While the precursor sheet was conveyed in the first direction, the unpainted portion was pressed using the elastic roll. The pressing was performed with a constant compressive force of the elastic roll while changing the roll gap from 30 mm to 70 mm. The results are shown in Fig. 6(b).

[0061] As shown in Fig. 6(b), the elongation rate of the unpainted portion decreased as the roll gap increased. This is presumably because the larger the roll gap, the smaller the deformation amount of the elastic body (the smaller the deformation force applied to the unpainted portion), and the smaller the roll gap, the larger the deformation amount of the elastic body (the larger the deformation force applied to the unpainted portion). From this, it was confirmed that the deformation amount of the elastic body (the deformation force applied to the unpainted portion) can be adjusted by the roll gap.

Explanation of Reference Numerals

[0062] 1... Metal foil 2... Painted portion 3... Unpainted portion 10... Precursor sheet 21... Shaft body 22... Elastic body 20... Elastic roll

Claims

Claim 1 A preparation step of preparing a precursor sheet having a metal foil with a longitudinal direction in a first direction, and a coated portion and an uncoated portion disposed on the metal foil; A coated portion pressing step of pressing the coated portion in a thickness direction while conveying the precursor sheet in the first direction; An uncoated portion pressing step of pressing the uncoated portion in the thickness direction while conveying the precursor sheet in the first direction before or after the coated portion pressing step; characterized by comprising: The coated portion contains an electrode material containing at least an active material; The uncoated portion does not contain the electrode material and is disposed at an end of the coated portion in a direction orthogonal to the first direction; In the uncoated portion pressing step, while applying a compressive force for pressing the uncoated portion in the thickness direction using a pair of elastic rolls having a shaft body and an elastic body made of rubber or resin covering the shaft body, roll pressing is performed; A method for manufacturing an electrode, wherein at least one of (i) the compressive force and (ii) a gap between the pair of elastic rolls is adjusted according to a conveyance speed so that a deformation force applied to the uncoated portion becomes constant during the roll pressing. Claim 2 When adjusting the compression force, the first conveyance speed is V １ and the compression force at the V １ is C １ The reference conveyance speed is V Ｂ and the compression force at the V Ｂ is C Ｂ When the V １ is smaller than the V Ｂ , the C １ is made smaller than the C Ｂ The method for manufacturing an electrode according to claim 1. Claim 3 When adjusting the compression force, (i-A) corresponding to the behavior in which the V １ increases to the V Ｂ , the C １ is increased to the C Ｂ , and (i-B) corresponding to the behavior in which the V １ decreases from the V Ｂ , the C １ is decreased from the C Ｂ , at least one of which is performed. The method for manufacturing an electrode according to claim 2. Claim 4 When adjusting the gap between the pair of elastic rolls, the first conveyance speed is V １ and the gap at the V １ is G １ The reference conveyance speed is V Ｂ and the gap at the V Ｂ is G Ｂ When the V １ is smaller than the V Ｂ , the G １ is set to be larger than the G Ｂ The method for manufacturing an electrode according to claim 1. Claim 5 When adjusting the gap between the pair of elastic rolls, (ii-A) corresponding to the behavior in which the V １ increases up to the V Ｂ , the G １ is decreased to the G Ｂ , and, (ii-B) corresponding to the behavior in which the V １ decreases from the V Ｂ , the G １ is increased from the G Ｂ , at least one of which is performed. The method for manufacturing an electrode according to claim 4.

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