JP2024100486A - Manufacturing method for electrode - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a manufacturing method for an electrode, in which occurrence of a crease is suppressed.

SOLUTION: A manufacturing method for an electrode includes: a step of preparing a precursor sheet including a metal foil with a longitudinal direction in a first direction X, and a coated part and an uncoated part disposed on the metal foil; a first uncoated part pressing step of roll-pressing the uncoated part in a thickness direction of the precursor sheet while conveying the precursor sheet in the first direction using an elastic roll A1 and an elastic roll A2; a coated part pressing step of pressing the coated part in the thickness direction while conveying the precursor sheet in the first direction after the first uncoated part pressing step; and a second uncoated part pressing step of roll-pressing the uncoated part again in the thickness direction while conveying the precursor sheet in the first direction after the coated part pressing step.

SELECTED DRAWING: Figure 1

COPYRIGHT: (C)2024,JPO&INPIT

Description

This disclosure relates to a method for manufacturing an electrode.

One known method for manufacturing electrodes is to roll a sheet in which an electrode mixture is applied onto a long metal foil.

For example, Patent Document 1 discloses a method for pressing a battery electrode having a coated portion coated with an electrode active material and an uncoated portion not coated with the electrode active material. Patent Document 2 discloses stretching the uncoated portion with a rolling roll in a roll press equipped with a wrinkle prevention device. Patent Document 3 discloses a method for stretching only the uncoated portion of the electrode material under tension between guide rolls using an uncoated portion stretching mechanism.

Patent No. 5760366 JP 2019-102172 A JP 2014-220113 A

When pressing a sheet having coated and uncoated areas, the coated and uncoated areas may be pressed separately to adjust the difference in elongation to prevent wrinkles from occurring. In addition, the uncoated areas may be roll pressed using an elastic roll to prevent breakage of the uncoated areas when pressed.

In this case, the coated portion acts as a resistance in the uncoated portion on the coated side, and sufficient stretching may not be achieved. In that case, the uncoated portion cannot be stretched uniformly as a whole, causing wrinkles in the uncoated portion, which may result in wrinkles (waviness) in the resulting electrode.

This disclosure was made in consideration of the above-mentioned circumstances, and its main objective is to provide a method for manufacturing electrodes that suppresses the occurrence of wrinkles.

[1]
a preparation 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 arranged on the metal foil; a first uncoated portion pressing step of using an elastic roll A1 and an elastic roll A2 to roll-press the uncoated portion in a thickness direction of the precursor sheet while transporting the precursor sheet in the first direction; a coated portion pressing step of pressing the coated portion in the thickness direction while transporting the precursor sheet after the first uncoated portion pressing step in the first direction; and a second uncoated portion pressing step of roll-pressing again in the thickness direction, wherein the coated portion contains an electrode material including at least an active material and is arranged on at least a first surface of the metal foil in the thickness direction, the uncoated portions do not contain the electrode material and are arranged on both ends of the coated portion in a second direction perpendicular to the first direction, the elastic roll A1 comprises a metal shaft A1 and an elastic body A1 covering a portion of the shaft A1 in the axial direction of the shaft A1, and the elastic roll A2 comprises a metal shaft A2 and an elastic body A2 covering a portion of the shaft A2 in the axial direction of the shaft A2.

[2]
The elastic roll A1 is a stepped roll having, in the axial direction of the shaft A1, a pair of roll portions A1 in which the shaft A1 is covered with the elastic body A1, and a non-roll portion A1 that is disposed between the pair of roll portions A1 and in which the shaft A1 is not covered with the elastic body A1, and the elastic roll A2 is a cylindrical roll having one roll portion A2 in the axial direction of the shaft A2, and in the first uncoated portion pressing step, the roll press is performed by disposing the elastic roll A1 so as to be located on the first surface side with respect to the precursor sheet and the pair of roll portions A1 so as to be in contact with the uncoated portions, and disposing the elastic roll A2 so as to be located on the second surface side of the metal foil that faces the first surface with respect to the precursor sheet.

[3]
In the second uncoated portion pressing step, the roll press is performed using an elastic roll B1 and an elastic roll B2, the elastic roll B1 includes a metal shaft B1 and an elastic body B1 covering a portion of the shaft B1 in an axial direction of the shaft B1, the elastic roll B2 includes a metal shaft B2 and an elastic body B2 covering a portion of the shaft B2 in the axial direction of the shaft B2, a portion of the shaft B1 covered with the elastic body B1 is a roll portion B1, and when the roll portion B1 is viewed in cross section along the axial direction of the shaft B1, the roll portion B1 has a first side, a second side opposite to the first side, a third side connecting the first side and the second side, and a fourth side opposite to the third side, the amount of strain of the elastic body B1 in the first direction is greater at the first side than at the second side, and the amount of strain increases continuously or intermittently from the second side to the first side, and the thickness of the elastic body B1 changes continuously or intermittently from the second side to the first side, and in the second uncoated portion pressing step, the elastic roll B1 is positioned on the first surface side with respect to the precursor sheet, the first side is positioned on the coated portion side in the second direction, the elastic roll B1 is positioned so that the roll portion B1 is in contact with the uncoated portion, and the elastic roll B2 is positioned so that the elastic roll B2 is positioned on the second surface side, and the roll pressing is performed.

[4]
The method for producing an electrode according to [1] or [2], wherein in the second uncoated portion pressing step, the roll pressing is performed using a pair of metal rolls.

The present disclosure has the effect of making it possible to manufacture electrodes that suppress the occurrence of wrinkles.

FIG. 1 is a flow diagram illustrating a method for manufacturing an electrode in the present disclosure. FIG. 2 is a schematic plan view illustrating a precursor sheet in the present disclosure. FIG. 2 is a schematic plan view illustrating an elastic roll A1 and an elastic roll A2 according to the present disclosure. FIG. 2 is a schematic plan view illustrating a first uncoated portion pressing step in the present disclosure. 3 is a schematic cross-sectional view illustrating an example of the shape and arrangement of an elastic roll B1 in the present disclosure. FIG.

The manufacturing method of the electrode in this disclosure will be described in detail below. In this specification, when expressing the manner in which another member is disposed relative to a certain member, the term "above" or "below" refers to both the case where another member is disposed directly above or below a certain member so as to be in contact with the certain member, and the case where another member is disposed above or below a certain member via another member, unless otherwise specified.

Figure 1 is a flow diagram showing an example of a method for manufacturing an electrode according to the present disclosure. In Figure 1, first, a precursor sheet is prepared (preparation step) having a metal foil with a longitudinal direction in a first direction, and a coated portion and an uncoated portion arranged on the metal foil. In the precursor sheet, the coated portion contains an electrode material including at least an active material, and is arranged on at least the first surface of the metal foil in the thickness direction of the precursor sheet. The uncoated portion does not contain the electrode material, and is arranged on both ends of the coated portion in a second direction perpendicular to the first direction.

Next, the uncoated portion is roll-pressed in the thickness direction of the precursor sheet using the elastic roll A1 and the elastic roll A2 while transporting the precursor sheet in the first direction (first uncoated portion pressing process). The elastic roll A1 includes a metal shaft A1 and an elastic body A1 that covers a part of the shaft A1 in the axial direction of the shaft A1. The elastic roll A2 includes a metal shaft A2 and an elastic body A2 that covers a part of the shaft A2 in the axial direction of the shaft A2.

Next, the precursor sheet after the first uncoated portion pressing process is conveyed in the first direction while pressing the coated portion in the thickness direction (coated portion pressing process).

Then, while conveying the precursor sheet after the coated portion pressing process in the first direction, the uncoated portion is roll-pressed again in the thickness direction (second uncoated portion pressing process)

According to the present disclosure, the first uncoated section press process is performed before the coated section press process, and the second uncoated section press process is performed after the coated section press process, so that an electrode in which the occurrence of wrinkles is suppressed can be manufactured.

As described above, in the portion of the uncoated part on the coated part side, the coated part may provide resistance and a sufficient amount of stretching may not be obtained. In such a case, the entire uncoated part may not be stretched uniformly with only one roll press, and wrinkles may occur in the uncoated part. Furthermore, even if the coated part is pressed after the uncoated part is pressed, the uncoated part is not stretched, and the wrinkles in the uncoated part are not eliminated. As a result, wrinkles may occur in the obtained electrode. In contrast, in the present disclosure, the uncoated part is roll pressed a total of two times before and after pressing the coated part, so that the difference in the amount of stretching in the uncoated part can be reduced. As a result, the occurrence of wrinkles (waviness) can be suppressed in the manufactured electrode.

Here, the metal foil generally contains a hard tissue harder than the material of the metal foil as an inclusion. By including the hard tissue, for example, the strength of the metal foil can be increased. When a tensile force (horizontal force) is applied to stretch the metal foil, the hard tissue does not deform, but the surrounding metal foil, which is softer than the hard tissue, deforms. As a result, voids are formed around the hard tissue. When multiple voids are connected to each other, breakage is likely to occur. In contrast, in the first uncoated part pressing process in the present disclosure, the elastic roll A1 and the elastic roll A2 are used to perform roll pressing while applying a compressive force pressing in the thickness direction. This allows the uncoated part to be applied with the above compressive force and a deformation force due to the deformation of the elastic body. As a result, it is believed that the manufacturing method of the electrode in the present disclosure can suppress the generation of voids around the hard tissue and also suppress breakage of the uncoated part (metal foil). The above compressive force corresponds to a force in the thickness direction, and the above deformation force corresponds to a force in a direction perpendicular to the thickness direction. In other words, the deformation force acts in the same direction as the tensile force and stretches the metal foil in the same way as the tensile force.

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.

2 is a schematic diagram illustrating a precursor sheet prepared in the first preparation step. Specifically, FIG. 2(a) is a schematic plan view of the precursor sheet viewed from the thickness direction Z. FIGS. 2(b) and 2(c) are schematic plan views of the precursor sheet viewed from the first direction X of the metal foil. As shown in FIGS. 2(a) to 2(c), the precursor sheet 10 has a metal foil 1 having a longitudinal direction in the first direction X, a coated portion 2, and an uncoated portion 3. The coated portion is disposed at least on the first surface P of the metal foil in the thickness direction. As shown in FIG. 2(b), the coated portion 2 may be disposed only on the first surface P of the metal foil 1 in the thickness direction Z. On the other hand, as shown in FIG. 2(c), the coated portion 2 may be disposed on both the first surface P and the second surface Q opposite the first surface P in the thickness direction Z.

Examples of materials for the metal foil include metals used as materials for battery current collectors. Details are described in "5. Electrodes." The thickness of the metal foil is, for example, 1 μm or more and 100 μm or less. Here, the metal foil in this disclosure may be a foil (laminated foil) in which multiple metal foils are laminated via adhesive layers. In this case, the first surface and the second surface refer to the main surfaces (outermost surfaces) of the laminated foil.

The coated portion of the precursor sheet contains an electrode material that includes at least an active material. The coated portion becomes an electrode layer through the coated portion pressing process described below.

The electrode material contains at least an active material. The electrode material may also contain at least one of an electrolyte, a conductive material, and a binder, as necessary. The active material, electrolyte, conductive material, and binder are described in "5. Electrodes."

The coated portions are preferably arranged along the first direction of the metal foil. Also, the coated portions may be arranged continuously along the first direction X of the metal foil 1 as shown in FIG. 2(a). On the other hand, the coated portions may be arranged intermittently along the first direction of the metal foil.

The thickness of the coated portion is not particularly limited and can be adjusted appropriately according to the desired electrode size. The thickness of the coated portion is, for example, 0.2 mm or more and 1.5 mm or less.

The uncoated portion is disposed on the metal foil and does not contain an electrode material. The uncoated portion is usually disposed on the same surface of the metal foil as the coated portion. The uncoated portion is, for example, a portion where the metal foil is exposed. As shown in Figures 2(a) to (c) , the uncoated portion 3 in this disclosure is disposed at both ends of the coated portion 2 in the second direction Y perpendicular to the first direction X of the metal foil 1.

As shown in Figs. 2(a) to (c), the uncoated portion 3 in the precursor sheet 10 may have a protective layer 4 at the boundary with the coated portion 2. The material of the protective layer is not particularly limited, but examples include resins such as polyvinylidene fluoride (PVDF).

The ratio of coated and uncoated areas in the precursor sheet (ratio of length in the second direction) and the ratio of protective layer in the uncoated areas are not particularly limited and can be adjusted as appropriate.

2. First Uncoated Portion Pressing Step The first uncoated portion pressing step in the present disclosure is a step of roll-pressing the uncoated portion in the thickness direction of the precursor sheet using the elastic roll A1 and the elastic roll A2 while transporting the precursor sheet in the first direction.

The elastic roll A1 and the elastic roll A2 used in the first uncoated portion pressing process are described with reference to the drawings. FIG. 3(a) is a schematic plan view illustrating the elastic roll A1, and FIG. 3(b) is a schematic plan view illustrating the elastic roll A2. As shown in FIGS. 3(a) and (b), the elastic roll A1 (20A) includes a metal shaft A (21A) and an elastic body A (22A) that covers a part of the shaft A1 (21A) in the axial direction D of the shaft A1 (21A). Similarly, the elastic roll A2 (30A) includes a metal shaft A2 (31A) and an elastic body A2 (32A) that covers a part of the shaft A2 (31A) in the axial direction D of the shaft A2 (31A).

The metal used for shaft A1 and shaft A2 is not particularly limited, and may be a conventionally known material such as iron or SUS. Elastic body A1 and elastic body A2 preferably have a predetermined Young's modulus. The Young's modulus is, for example, 11.1 MPa or more and 86.1 MPa or less. Examples of materials for elastic body A1 and elastic body A2 include rubber, urethane, and other resins.

As shown in FIG. 3(a), the elastic roll A1 is preferably a stepped roll having a pair of roll parts A1 (20Aa) in which the shaft A1 (21A) is covered with an elastic body A1 (22A) in the axial direction D of the shaft A1 (21A), and a non-roll part A1 (20Ab) disposed between the pair of roll parts A1 (20Aa) and in which the shaft A1 (21A) is not covered with the elastic body A1 (22A). As shown in FIG. 3(b), the elastic roll A2 (30A) is preferably a cylindrical roll having one roll part A2 (30Aa) in which the shaft A2 (31A) is covered with an elastic body A2 (32A) in the axial direction D of the shaft A2 (31A).

As shown in Figures 3(a) and (b), whether the elastic roll is a stepped roll or a cylindrical roll, the roll portions (20Aa and 30Aa) are usually provided at both ends in the axial direction D with non-roll portions (20Ab and 30Ab).

Figure 4(a) is a schematic plan view of the first uncoated portion pressing process viewed from the second direction Y, and Figure 4(b) is a schematic plan view of the first uncoated portion pressing process viewed from the first direction (conveying direction) X. As shown in Figures 4(a) and (b), in the first uncoated portion pressing process, it is preferable to perform roll pressing by arranging the elastic roll A1 (20A) so that the elastic roll A1 (20A) is located on the first surface P side of the precursor sheet 10 and the pair of roll parts A1 (20Aa) are in contact with the uncoated portion 3, and arranging the elastic roll A2 (30A) so that the elastic roll A2 (30A) is located on the second surface Q side of the metal foil 3 facing the first surface P of the precursor sheet 10.

Here, the elastic rolls A1 and A2 are typically arranged so that their axial directions are parallel to the second direction. In addition, in the direction of gravity, it is preferable that the elastic roll A1 is arranged above the precursor sheet, and the elastic roll A2 is arranged below the precursor sheet.

3. Coated Section Pressing Step The coated section pressing step in the present disclosure is a step of pressing the coated section in a thickness direction while transporting the precursor sheet after the first uncoated section pressing step in the first direction.

The method for the coating section pressing step is not particularly limited. For example, a roll pressing method can be used in which a pair of cylindrical rolls are placed on the first and second sides of the precursor sheet.

The compression force in the coated section press step is not particularly limited, but is preferably greater than the compression force in the first uncoated section press step and the second uncoated section press step. This is because wrinkles may occur in the coated section of the precursor sheet when it is wetted with the electrode material (slurry) containing a dispersion medium, and a large stretching force is required to remove these wrinkles.

4. Second Uncoated Portion Pressing Step The second uncoated portion pressing step in the present disclosure is a step of roll-pressing the uncoated portion again in the thickness direction while transporting the precursor sheet after the coated portion pressing step in the first direction.

The roll press in the second uncoated portion pressing step is not particularly limited, but may be, for example, a method using a pair of elastic rolls (elastic roll B1 and elastic roll B2). Elastic roll B1 comprises a metal shaft B1 and an elastic body B1 that covers a part of shaft B1 in the axial direction of shaft B1. Similarly, elastic roll B2 comprises a metal shaft B2 and an elastic body B2 that covers a part of shaft B2 in the axial direction of shaft B2. Metal shafts B1 and B1, and elastic bodies B1 and B2 may be similar to shafts A1 and A2, and elastic bodies A1 and A2 described above.

The elastic roll B1 used in the roll press in the second uncoated portion pressing step will be described with reference to FIG. 5. As shown in FIGS. 5(a) and (c), when the portion of the shaft B1 (21B) covered with the elastic body B1 (22B) is the roll portion B1 (20Ba) and the roll portion B (20Ba) is viewed in cross section along the axial direction D of the shaft B (21B), it is preferable that the roll portion B1 (20Ba) has a first side s1, a second side s2 opposite the first side s1, a third side s3 connecting the first side s1 and the second side s2, and a fourth side s4 opposite the third side s3.

In the roll portion B1 of the first elastic roll B1, it is preferable that the amount of strain of the elastic body B1 is greater on the first side than on the second side, and that the amount of strain increases continuously or intermittently from the second side toward the first side. Here, in this specification, "amount of strain" refers to the ratio (T'/T) of the compressed length T' (deformation amount of the elastic body B1) of the elastic body B1 to the original length T (thickness) of the elastic body B1 when a compressive force is applied to the first elastic roll B1 in the thickness direction (direction perpendicular to the axial direction).

When a compressive force is applied to the roll portion B1 (20Ba) of the first elastic roll B1 as shown in Figures 5(a) and (c) in the direction Z perpendicular to the axial direction D, the elastic body 22B shrinks (distorts) in the direction Z as shown in Figures 5(b) and (d). In the first elastic roll B1, the amount of distortion (T'/T) of the elastic body 22B is larger at the first side s1 than at the second side s2 ((T1'/T1)>(T2'/T2)). In addition, the amount of distortion (T'/T) increases continuously or intermittently from the second side s2 toward the first side s1. It can be considered that the deformation force of the elastic body described above is large on the side with the larger amount of distortion (the first side). Therefore, as shown in FIG. 5(e), by performing roll pressing with the first elastic roll B1 positioned so that the side with the larger amount of strain (the first side) is located on the coated side of the uncoated part, the amount of stretching can be increased on the coated side of the uncoated part. As a result, an electrode with more suppressed wrinkles can be manufactured.

As shown in Fig. 5(a) and Fig. 5(c), it is preferable that the thickness T of the elastic body B1 (21B) changes continuously or intermittently from the second side s2 toward the first side s1. Here, the thickness of the elastic body refers to the thickness of the elastic body on one side based on the axis in a direction perpendicular to the axial direction in the above cross-sectional view. Furthermore, the thickness changes continuously (increases or decreases) means that the thickness of the elastic body changes gradually, for example, as shown in Fig. 5(c). Furthermore, the thickness changes intermittently (increases or decreases) means that the thickness of the elastic body has both a region where the thickness of the elastic body changes and a region where it does not change, for example, as shown in Fig. 5(a). In Fig. 5(a), the region where the thickness of the axis decreases in the direction from the first side toward the second side (tapered region) is a region where the thickness of the elastic body changes (increases), and the region where the thickness of the axis is constant in the direction from the first side toward the second side (non-tapered region) is a region where the thickness of the elastic body does not change (does not increase or decrease). The above strain relationship can be obtained by changing the thickness of the elastic body.

As shown in FIG. 5(e), in the second uncoated portion pressing step, it is preferable to perform roll pressing by arranging the elastic roll B1 (20Ba) so that the elastic roll B1 (20B) is located on the first surface side P with respect to the precursor sheet 10, the first side s1 is located on the coated portion 2 side in the second direction Y, and the roll portion B1 (20Ba) is in contact with the uncoated portion 3. By arranging the elastic roll B1 in this manner, the amount of strain of the elastic body can be increased on the coated portion side of the uncoated portion, and the deformation force of the elastic body can be increased on the coated portion side. As a result, the coated portion side of the uncoated portion can be stretched in a concentrated manner, and wrinkles in the uncoated portion can be further suppressed. In addition, although not shown, it is preferable to perform roll pressing by arranging the elastic roll B2 so that the elastic roll B2 is located on the second surface side.

In addition, the roll press in the second uncoated portion press step can be a method using a pair of metal rolls. As the pair of metal rolls, it is preferable to use a metal stepped roll and a metal cylindrical roll. It is preferable to perform roll press by placing the stepped roll on the first surface side of the precursor sheet and the cylindrical roll on the second surface side of the precursor sheet. In addition, when using a pair of metal rolls for roll press, it is preferable to perform the roll press while applying tension to the electrode precursor sheet. In addition, in the second uncoated portion press step, it is assumed that the amount of stretching of the uncoated portion required is small, and the tension can be reduced. Therefore, even when metal rolls are used, breakage of the uncoated portion is suppressed.

5. Electrode In the electrode manufactured by the method of the present disclosure, an electrode layer is formed on at least one surface of the metal foil. The electrode layer is a layer obtained by pressing the coated portion. The electrode manufactured by the method of the present disclosure may be a positive electrode or a negative electrode. In other words, the electrode layer may be a positive electrode active material layer or a negative electrode active material layer.

The metal foil typically functions as a 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.

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. The positive electrode active material typically includes an oxide active material. Examples of the oxide active material include rock salt layer type active materials such as LiCoO ₂ , LiMnO ₂ , LiNiO ₂ , LiVO ₂ , and LiNi _1/3 Co _1/3 Mn _1/3 O ₂ , spinel type active materials such as LiMn ₂ O ₄ and Li (Ni _0.5 Mn _1.5 ) O ₄ , and olivine type active materials such as LiFePO ₄ , LiMnPO ₄ , LiNiPO ₄ , and LiCuPO ₄ .

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 material, oxide active material, and metal active material. Examples of the carbon active material include mesocarbon microbeads (MCMB), highly oriented graphite (HOPG), hard carbon, and soft carbon. Examples of the oxide active material include NB ₂ O ₅ , Li ₄ Ti ₅ O ₁₂ , and SiO. Examples of the metal active material include In, Al, Si, and Sn.

The electrode layer may also contain at least one of an electrolyte, a conductive material, and a binder, as necessary.

The electrolyte may be, for example, a non-aqueous electrolyte containing a non-aqueous solvent and a supporting salt. The non-aqueous solvent may be, for example, an organic solvent such as carbonates, ethers, esters, nitriles, sulfones, or lactones. The supporting salt may be, for example, a lithium salt such as LiPF6. The conductive material may be, for example, a carbon material, metal particles, or a conductive polymer. The carbon material may be, for example, a particulate carbon material such as acetylene black (AB) or ketjen black (KB); or a fibrous carbon material such as carbon fiber, carbon nanotube (CNT), or carbon nanofiber (CNF). The binder may be, for example, a fluorine-containing binder such as polyvinylidene fluoride (PVDF) or polytetrafluoroethylene (PTFE), a rubber-based binder such as butadiene rubber, or an acrylic binder.

The use of the electrodes in this disclosure includes, for example, Li-ion batteries. The battery in this disclosure may also be a liquid-based battery in which the electrolyte layer contains a liquid electrolyte (electrolytic solution). The use of the batteries in this disclosure is not particularly limited, but may include, for example, power sources for vehicles such as hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles (PHEVs), electric vehicles (BEVs), gasoline-powered vehicles, and diesel-powered vehicles. In particular, it is preferable to use the batteries as driving power sources for hybrid electric vehicles, plug-in hybrid electric vehicles, or electric vehicles. The batteries in this disclosure may also be used as power sources for moving objects other than vehicles (for example, railways, ships, and aircraft), and may also be used as power sources for electrical products such as information processing devices.

This disclosure is not limited to the above-mentioned embodiments. The above-mentioned embodiments are merely examples, and anything that has substantially the same configuration as the technical ideas described in the claims of this disclosure and has similar effects is included within the technical scope of this disclosure.

Reference Signs List 1: Metal foil 2: Coated portion 3: Uncoated portion 10: Precursor sheet 20A: Elastic roll A1
20B ... Elastic roll B1
30A ... Elastic roll A2
30B ... Elastic roll B2

Claims (4)

A preparation 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;
a first uncoated portion pressing step of roll-pressing the uncoated portion in a thickness direction of the precursor sheet using an elastic roll A1 and an elastic roll A2 while transporting the precursor sheet in the first direction;
a coated portion pressing step of pressing the coated portion in the thickness direction while conveying the precursor sheet after the first uncoated portion pressing step in the first direction;
a second uncoated portion pressing step of roll-pressing the uncoated portion again in the thickness direction while transporting the precursor sheet after the coated portion pressing step in the first direction,
the coated portion contains an electrode material including at least an active material, and is disposed on at least a first surface of the metal foil in the thickness direction;
the uncoated portions do not contain the electrode material and are arranged on both ends of the coated portion in a second direction perpendicular to the first direction,
The elastic roll A1 includes a metal shaft A1 and an elastic body A1 that covers a part of the shaft A1 in the axial direction of the shaft A1,
The elastic roll A2 includes a metal shaft A2 and an elastic body A2 covering a portion of the shaft A2 in the axial direction of the shaft A2. The elastic roll A1 is a stepped roll having, in the axial direction of the shaft A1, a pair of roll portions A1 in which the shaft A1 is covered with the elastic body A1, and a non-roll portion A1 disposed between the pair of roll portions A1 and in which the shaft A1 is not covered with the elastic body A1,
The elastic roll A2 is a cylindrical roll having one roll portion A2 in which the shaft A2 is covered with the elastic body A2 in the axial direction of the shaft A2,
In the first uncoated portion pressing step,
The elastic roll A1 is disposed so that the elastic roll A1 is located on the first surface side of the precursor sheet and the pair of roll portions A1 are in contact with the uncoated portions, and
The method for manufacturing an electrode according to claim 1 , wherein the roll pressing is performed by disposing the elastic roll A2 so that the elastic roll A2 is located on a second surface side of the metal foil that faces the first surface of the precursor sheet. In the second uncoated portion pressing step, the roll pressing is performed using an elastic roll B1 and an elastic roll B2,
The elastic roll B1 includes a metal shaft B1 and an elastic body B1 that covers a part of the shaft B1 in the axial direction of the shaft B1,
The elastic roll B2 includes a metal shaft B2 and an elastic body B2 that covers a part of the shaft B2 in the axial direction of the shaft B2,
When a portion of the shaft B1 covered with the elastic body B1 is defined as a roll portion B1 and the roll portion B1 is viewed in cross section along the axial direction of the shaft B1,
The roll portion B1 has a first side, a second side opposite to the first side, a third side connecting the first side and the second side, and a fourth side opposite to the third side,
In the roll section B1,
The amount of strain of the elastic body B1 in a direction perpendicular to the axial direction of the axis B1 is greater on the first side than on the second side, and
the amount of strain increases continuously or intermittently from the second side toward the first side,
The thickness of the elastic body B1 changes continuously or intermittently from the second side toward the first side,
In the second uncoated portion pressing step,
the elastic roll B1 is disposed so that the elastic roll B1 is located on the first surface side of the precursor sheet, the first side is located on the coated portion side in the second direction, and the roll portion B1 is in contact with the uncoated portion; and
The method for manufacturing an electrode according to claim 1 or 2, wherein the roll pressing is performed by disposing the elastic roll B2 so as to be located on the second surface side. The method for manufacturing an electrode according to claim 1 or 2, wherein the roll press in the second uncoated portion pressing step is performed using a pair of metal rolls.