Electrode manufacturing method

Abstract

To provide a method for manufacturing an electrode capable of suppressing warpage.SOLUTION: A method for manufacturing an electrode includes a preparation step of preparing a first precursor sheet including a metal foil having a longitudinal direction in a first direction and a first coated part arranged on a first surface of the metal foil, and a coated part pressing step of pressing the first coated part in a thickness direction while transporting the first precursor sheet in the first direction. The first coated part contains an electrode material A. In the coated part pressing step, the method performs roll-press while pressing the first coated part in the thickness direction using a roll A and a roll B being a pair of rolls. When the rolls perform roll-press, the method arranges the roll A in the first coated part side of the first precursor sheet in the thickness direction, and arranges the roll B on the metal foil side of the first precursor sheet in the thickness direction. The method also arranges an elastic body sheet between the metal foil and the roll B, and performs roll-press.SELECTED DRAWING: Figure 1

Description

[Technical field]

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

[0002] As a method for manufacturing an electrode, a method of rolling a sheet in which an electrode mixture is applied onto a long metal foil is known. For example, Patent Document 1 discloses a method for manufacturing an electrode by pressing an electrode mixture layer formed on a metal foil in the thickness direction. Specifically, the method discloses a method for manufacturing an electrode in which a negative electrode active material layer is formed on a first surface of a first metal foil, the negative electrode active material layer is pressed in a state in which the first surface of a second metal foil faces the second surface of the first metal foil, a positive electrode active material layer is formed on the second surface of the second metal foil, and the positive electrode active material layer is pressed. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2021-082504 A Summary of the Invention [Problem to be solved by the invention]

[0004] When a sheet having an electrode mixture layer (coated portion) is pressed (roll pressed) in the thickness direction, the applied compressive force stretches the coated portion and the metal foil. On the other hand, the elongation rate of the coated portion and the metal foil generally differs. In addition, when coated portions made of different materials are formed on both sides of the metal foil, the elongation rate of the coated portions differs due to, for example, the difference in materials. In this case, the side of the sheet with a higher elongation rate stretches more than the side of the sheet with a lower elongation rate due to pressing, which may cause the sheet to warp.

[0005] The present disclosure has been made in consideration of the above-mentioned circumstances, and has as its main object to provide a manufacturing method for an electrode that can suppress the occurrence of warping. [Means for solving the problem]

[0006] [1] A method for manufacturing an electrode, comprising: a preparation step of preparing a first precursor sheet having a metal foil having a longitudinal direction in a first direction and a first coated portion arranged on a first surface of the metal foil; and a coated portion pressing step of pressing the first coated portion in a thickness direction while transporting the first precursor sheet in the first direction, wherein the first coated portion contains an electrode material A, and in the coated portion pressing step, a pair of rolls, roll A and roll B, are used to perform roll pressing while pressing the first coated portion in the thickness direction, and during the roll pressing, the roll A is disposed on the first coated portion side of the first precursor sheet in the thickness direction, and the roll B is disposed on the metal foil side of the first precursor sheet in the thickness direction, and an elastic sheet is disposed between the metal foil and the roll B, and the roll pressing is performed.

[0007] [2] The method for producing an electrode according to [1], wherein the electrode material A contains a positive electrode active material.

[0008] [3] The method includes a preparation step of preparing a second precursor sheet having a metal foil having a longitudinal direction in a first direction, a second coated portion arranged on a first surface of the metal foil, and a third coated portion arranged on a second surface of the metal foil opposing the first surface, and a coated portion pressing step of pressing the second coated portion and the third coated portion in a thickness direction while conveying the second precursor sheet in the first direction, wherein the second coated portion contains an electrode material B, the third coated portion contains an electrode material C, and the third coated portion has an elongation in the first direction smaller than that of the second coated portion. a coated portion pressing step using a pair of rolls, roll A and roll B, to press the second coated portion and the third coated portion in the thickness direction, wherein, during the roll pressing, roll A is disposed on the second coated portion side of the second precursor sheet in the thickness direction and roll B is disposed on the third coated portion side of the second precursor sheet in the thickness direction, and an elastic sheet is disposed between the third coated portion and roll B, and the roll pressing is performed.

[0009] [4] The method for producing an electrode according to [3], wherein the electrode material B contains a positive electrode active material, and the electrode material C contains a negative electrode active material.

[0010] [5] The method for manufacturing an electrode according to any one of [1] to [4], wherein the roll A and the roll B are elastic rolls each having a shaft body and an elastic body covering the shaft body. Effect of the Invention

[0011] The present disclosure has an effect of suppressing the occurrence of warping. [Brief description of the drawings]

[0012] [Figure 1] FIG. 1 is a flow diagram illustrating a method for manufacturing an electrode in the present disclosure. [Diagram 2] FIG. 1 is a diagram illustrating the mechanism in the present disclosure. [Diagram 3]FIG. 2 is a diagram illustrating a coating section pressing step in the present disclosure. [Figure 4] FIG. 2 is a diagram illustrating a first precursor sheet in the present disclosure. [Diagram 5] FIG. 2 is a diagram illustrating a second precursor sheet in the present disclosure. [Figure 6] FIG. 13 is a diagram illustrating an experimental example. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] Hereinafter, the manufacturing method of an electrode according to the present disclosure will be described in detail. In this specification, when expressing an aspect in which another member is disposed on a certain member, the term "on" includes both a case in which another member is disposed directly on a certain member so as to be in contact with the certain member, and a case in which another member is disposed above a certain member via another member, unless otherwise specified.

[0014] In addition, in this disclosure, when a component is described without designations such as "first" and "second," both the components designated with the designations "first" and "second" are intended to be described unless otherwise specified.

[0015] FIG. 1 is a flow diagram showing an example of a method for producing an electrode according to the present disclosure. In FIG. 1, first, a predetermined precursor sheet is prepared (preparation step). Next, while the precursor sheet is transported in the first direction, the coated part is pressed in the thickness direction (coated part pressing step). In the coated part pressing step, roll pressing is performed using a pair of rolls (roll A and roll B) arranged at predetermined positions. In the present disclosure, roll pressing is performed by placing an elastic sheet between the metal foil and roll B, or between the third coated part and roll B. Here, in the present disclosure, the "thickness direction" is synonymous with the lamination direction of the metal foil and the coated part.

[0016] According to the present disclosure, by placing an elastic sheet between the metal foil and roll B, or between the third coating unit and roll B, and performing roll pressing, the occurrence of warping can be suppressed.

[0017] The mechanism of the manufacturing method of the electrode in the present disclosure will be explained with reference to the drawings. As shown in FIG. 2(a), in order to densify the coated portion 2 arranged on the metal foil 1, the precursor sheet 10 is conveyed in the first direction D and passed between a pair of rolls (rolls 20A and 20B) to perform roll pressing. The sheet is also stretched and thinned by roll pressing. On the other hand, generally, the metal foil is harder and less stretchable than the coated portion. Therefore, a difference in elongation occurs between the coated portion and the metal foil. As a result, as shown in FIG. 2(b), the coated portion with a large elongation rate may warp outward so that the perimeter matches, causing warping of the sheet. In contrast, in the present disclosure, as shown in FIG. 3(a), the elastic sheet 30 is placed between the metal foil 1 and the roll (roll 20B) to perform roll pressing. This allows the metal foil to be given the compressive force of pressing the pair of rolls against the precursor sheet and the deformation force of the elastic sheet due to the compressive force, so that the metal foil can be further stretched. As a result, the difference in elongation rate between the coated portion and the metal foil can be reduced, and the occurrence of warping in the electrode can be suppressed. In the precursor sheet shown in FIG. 2(a), the coated portion is disposed only on one side (first side) of the metal foil. However, even if the coated portion is disposed on both sides of the first side and the second side of the metal foil facing the first side, if the material (electrode material) of the coated portion is different, the elongation rate may differ between the coated portions. For example, the coated portion using a metal active material as the active material has a relatively low elongation rate, and the coated portion using an oxide active material as the active material has a relatively high elongation rate. In that case, as shown in FIG. 3(b), by disposing an elastic body between the coated portion with a low elongation rate and the roll, the difference in elongation rate can be reduced, and the occurrence of warping can be suppressed.

[0018] Furthermore, the electrode manufacturing method according to the present disclosure can suppress the occurrence of warping of the electrode, thereby suppressing breakage of the electrode during transportation. Furthermore, the accuracy of stacking multiple electrodes can be improved, and deterioration of the performance of the battery (stacked battery) can be suppressed.

[0019] 1. Preparation process The preparation step in this disclosure is a step of preparing a first precursor sheet or a second precursor sheet.

[0020] (1) First precursor sheet FIG. 4 is a diagram illustrating a first precursor sheet. Specifically, FIG. 4(a) is a plan view of the precursor sheet observed from the width direction of the metal foil, and FIG. 4(b) is a plan view of the precursor sheet 10A of FIG. 4(a) observed from the first coated part 2A side. As shown in FIG. 4(a), the first precursor sheet 10A has a metal foil 1 having a longitudinal direction in a first direction D and a first coated part 2A arranged on a first surface X of the metal foil. In addition, in the first precursor sheet 10A, a coated part is not usually arranged on a second surface Y of the metal foil opposite to the first surface X. That is, in the first precursor sheet, the coated part is arranged only on the first surface of the metal foil.

[0021] The material of the metal foil can be a metal used as a material of a battery current collector. Details will be 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.

[0022] The first coated portion of the first precursor sheet is disposed on the first surface of the metal foil and contains an electrode material A. The electrode material A usually contains at least an active material. The active material may be a negative electrode active material or a positive electrode active material, with the latter being preferred.

[0023] The positive electrode active material is typically an oxide active material. Examples of the oxide active material include LiCoO2, LiMnO2, LiNiO2, LiVO2, and LiNi 1 / 3 Co 1 / 3 Mn 1 / 3 O2, etc., rock salt layered active materials, LiMn2O4, Li(Ni 0.5 Mn 1.5 )O4 and other spinel-type active materials, and LiFePO4, LiMnPO4, LiNiPO4, LiCuPO4 and other olivine-type active materials.

[0024] 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 Nb2O5, Li4Ti5O 12 and SiO. Metal active materials include, for example, In, Al, Si, and Sn.

[0025] Furthermore, the electrode material A may contain at least one of a solid electrolyte, a conductive material, and a binder, as necessary. The solid electrolyte, the conductive material, and the binder are described in "4. Electrodes."

[0026] The first coated portion becomes an electrode layer through a coated portion pressing process described below. When electrode material A contains a positive electrode active material, the first coated portion becomes a positive electrode active material layer after pressing, and when electrode material A contains a negative electrode active material, the first coated portion becomes a negative electrode active material layer after pressing.

[0027] Moreover, the first coated portion is preferably arranged along the first direction of the metal foil. Moreover, the first coated portion may be arranged continuously along the first direction D of the metal foil 1 as shown in FIG. 4(b). On the other hand, the first coated portion 1 may be arranged intermittently along the first direction D of the metal foil 1.

[0028] The thickness of the first coated portion is not particularly limited and can be appropriately adjusted according to the desired electrode size. The thickness of the first coated portion is, for example, 0.2 mm or more, may be 0.3 mm or more, or may be 0.5 mm or more. On the other hand, the thickness of the first coated portion is, for example, 1.5 mm or less, may be 1.0 mm or less, or may be 0.6 mm or less.

[0029] The width of the first coated portion (the length in the direction perpendicular to the first direction of the metal foil) is not particularly limited and can be adjusted appropriately according to the desired electrode size. The ratio of the width of the first coated portion to the width of the metal foil is, for example, 30% or more, or may be 50% or more, or may be 70% or more. Moreover, the ratio is, for example, 90% or less, or may be 80% or less.

[0030] 4(b), the first precursor sheet of the present disclosure may have an uncoated portion 3 disposed at an end of the first coated portion in a direction perpendicular to the first direction. The uncoated portion is, for example, a portion where the metal foil is exposed. Although not shown, the uncoated portion may have a protective layer containing a resin at the boundary with the coated portion.

[0031] The width of the uncoated portion (the length in the direction perpendicular to the first direction of the metal foil) is not particularly limited and can be adjusted appropriately according to the desired electrode size. The ratio of the width of the uncoated portion to the width of the metal foil is, for example, 3% or more, and may be 5% or more. On the other hand, the ratio is, for example, 20% or less, and may be 10% or less.

[0032] The first precursor sheet can be prepared, for example, by applying an electrode material A containing a dispersion medium to the first surface of a metal foil and drying it. Examples of the dispersion medium include organic solvents such as butyl butyrate, dibutyl ether, and heptane. The method for applying the electrode material A is not particularly limited, and a general application method can be used. In addition, the drying temperature is not particularly limited as long as it is a temperature at which the dispersion medium volatilizes.

[0033] As shown in Fig. 4(b), the first precursor sheet 10A may have one row of first coated sections 2A and two rows of uncoated sections 3 arranged in a striped pattern at both ends of the first coated sections 2A. Although not shown, the first precursor sheet may be a sheet having N rows (N is an integer of 2 or more) of first coated sections in a plan view and uncoated sections arranged at both ends of each of the N rows of first coated sections. In this case, the number of rows of uncoated sections is N+1.

[0034] (2) Second precursor sheet Fig. 5 is a diagram illustrating the second precursor sheet, and is a plan view of the precursor sheet observed from the width direction of the metal foil. As shown in Fig. 5, the second precursor sheet 10B has a metal foil 1 having a longitudinal direction in a first direction D, a second coated section 2B arranged on a first surface X of the metal foil, and a third coated section 2C arranged on a second surface Y of the metal foil opposite to the first surface X. The metal foil is the same as that of the first precursor sheet, so a description thereof will be omitted.

[0035] The second coated portion of the second precursor sheet contains electrode material B. The third coated portion of the second precursor sheet contains electrode material C. Electrode material B and electrode material C each usually contain at least an active material. The active material contained in electrode material B and electrode material C may be a negative electrode active material or a positive electrode active material, respectively, but it is preferable that electrode material B contains a positive electrode active material and electrode material C contains a negative electrode active material. The positive electrode active material and the negative electrode active material are the same as those described in "(1) First precursor sheet".

[0036] Furthermore, electrode material B and electrode material C may each contain at least one of a solid electrolyte, a conductive material, and a binder, as necessary. The solid electrolyte, the conductive material, and the binder are the same as those described in "(1) First precursor sheet."

[0037] The third coated section has a lower elongation rate in the first direction than the second coated section. It is preferable to confirm the elongation rates of the second coated section and the third coated section in advance by a preliminary experiment. For example, in a preliminary test, a sample is roll-pressed, and the length of the sample in the first direction after the roll press is calculated relative to the length of the sample in the first direction before the roll press, to confirm the elongation rate (%).

[0038] If the elongation percentage of the second coated portion is X and the elongation percentage of the third coated portion is Y, Y / X is, for example, 0.1 or more, may be 0.3 or more, or may be 0.5 or more. Meanwhile, Y / X is, for example, 0.9 or less, may be 0.8 or less, may be 0.7 or less, or may be 0.6 or less. The elongation percentages X and Y may be, for example, 105% or more, 110% or more, or 120% or more, respectively.

[0039] The elongation percentages X and Y can be adjusted by changing the materials and the ratios of the materials in electrode material B and electrode material C. For example, when a metal active material is used as the active material, the elongation percentages are higher than when an oxide active material is used.

[0040] The coated portion of the second precursor sheet becomes an electrode layer through a coated portion pressing step described below.

[0041] The arrangement methods (continuous coating, intermittent coating) of the second coated portion and the third coated portion in the second precursor sheet are the same as those of the first coated portion described above. The thickness and width of the second coated portion and the third coated portion are also the same as those of the first coated portion described above.

[0042] The second precursor sheet may have uncoated sections at the ends of the second coated section and the third coated section in a direction perpendicular to the first direction. The uncoated sections are the same as those of the first precursor sheet described above.

[0043] The second precursor sheet can be prepared, for example, by coating a first surface of a metal foil with an electrode material B containing a dispersion medium, and then coating a second surface of the metal foil opposite to the first surface with an electrode material C containing a dispersion medium, followed by drying. The dispersion medium is the same as that for the first precursor sheet described above.

[0044] 2. Coating press process The pressing step in the present disclosure is a step of performing roll pressing while pressing the coated part in the thickness direction using a pair of rolls, roll A and roll B. In the roll pressing, roll A and roll B are disposed at predetermined positions. Then, roll pressing is performed with an elastic sheet disposed between the metal foil and roll B, or between the third coated part and roll A.

[0045] As shown in FIG. 3(a), roll A (20A) is disposed on the first coated section 2A side of the first precursor sheet 10A in the thickness direction, and roll B (20B) is disposed on the metal foil 1 side of the first precursor sheet 10A in the thickness direction. Then, an elastic sheet 30 is disposed between the metal foil 1 and roll B (20B) to perform roll pressing. By disposing the elastic sheet between the metal foil and roll B, the deformation force of the elastic sheet can be applied to the metal foil, so that the metal foil can be further stretched. As a result, the difference in elongation rate with the first coated section is reduced. In addition, in FIG. 3(a), roll A (20A) can be said to be disposed on the first coated section 2A side in the thickness direction with respect to the metal foil 1. Similarly, roll B (20B) can be said to be disposed on the opposite side of the first coated section 2A with respect to the metal foil 1 in the thickness direction.

[0046] As shown in FIG. 3(b), roll A (20A) is disposed on the second coated section 2B side of the second precursor sheet 10B in the thickness direction, and roll B (20B) is disposed on the third coated section 2C side of the second precursor sheet 10B in the thickness direction. Then, an elastic sheet 30 is disposed between the third coated section 2C and roll B (20B) to perform roll pressing. Although the third coated section has a lower elongation rate (is less likely to elongate) than the second coated section, disposing an elastic sheet between the third coated section and roll B allows the deformation force of the elastic sheet to be applied to the third coated section, so that the third coated section can be stretched more. As a result, the difference in elongation rate with the second coated section is reduced. In addition, in FIG. 3(b), roll A (20A) can be said to be disposed on the second coated section 2B side in the thickness direction with respect to the metal foil 1. Similarly, in other words, roll B (20B) is disposed on the third coating unit 2C side with respect to the metal foil 1 in the thickness direction.

[0047] The material of the elastic sheet is not particularly limited, but examples thereof include rubber, urethane, and other resins. The size of the elastic sheet is not particularly limited, but it is preferably larger than the precursor sheet.

[0048] Here, roll A and roll B may each be a metal roll, or as shown in Fig. 3, roll A and roll B may each be an elastic roll having a shaft body 21 and an elastic body 22 covering the shaft body.

[0049] The material of the shaft body is not particularly limited, but is preferably a material having a larger Young's modulus than the elastic body, and may be, for example, a metal.

[0050] The elastic body preferably has a predetermined Young's modulus, for example, not less than 11.1 MPa and not more than 86.1 MPa. Examples of materials for the elastic body include rubber and resins such as urethane.

[0051] 3.Other processes The manufacturing method of an electrode according to the present disclosure may include, before or after the coated portion pressing step, an uncoated portion pressing step of pressing the uncoated portion in the thickness direction while conveying the precursor sheet in the first direction. In the uncoated portion pressing step, it is preferable to roll press the uncoated portion while pressing it in the thickness direction using a pair of elastic rolls having a shaft and an elastic body covering the shaft.

[0052] By pressing the uncoated part, the uncoated part can be stretched to adjust the difference in elongation with the coated part. In addition, by using an elastic roll for roll pressing, breakage of the uncoated part (metal foil) can be suppressed. This is because both a compressive force pressing the elastic roll in the thickness direction and a deformation force resulting from the deformation of the elastic body can be applied to the uncoated part. The amount of elongation of the uncoated part can be adjusted by changing the deformation force resulting from the deformation of the elastic body. Details of the shaft body and the elastic body are the same as those of Roll A and Roll B described above.

[0053] 4. 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.

[0054] The metal foil typically functions as a current collector (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.

[0055] 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, and when the electrode layer is a negative electrode layer, the active material is a negative electrode active material. The positive electrode active material and the negative electrode active material are as described above in "1. Preparation step."

[0056] Furthermore, the electrode layer may contain at least one of a solid electrolyte, a conductive material, and a binder, as necessary.

[0057] The solid electrolyte may be, for example, an inorganic solid electrolyte. The inorganic solid electrolyte may be, for example, a sulfide solid electrolyte, an oxide solid electrolyte, a nitride solid electrolyte, or a halide solid electrolyte. In addition, the inorganic solid electrolyte may preferably have, for example, Li ion conductivity.

[0058] Examples of conductive materials include carbon materials, metal particles, and conductive polymers. Examples of carbon materials include particulate carbon materials such as acetylene black (AB) and ketjen black (KB); and fibrous carbon materials such as carbon fiber, carbon nanotubes (CNT), and carbon nanofibers (CNF). Examples of binders include fluorine-containing binders such as polyvinylidene fluoride (PVDF) and polytetrafluoroethylene (PTFE), rubber-based binders such as butadiene rubber, and acrylic binders.

[0059] Examples of applications of the electrodes in the present disclosure include Li-ion batteries. The battery in the present disclosure may be an all-solid-state battery in which the electrolyte layer contains an inorganic solid electrolyte. Applications of the batteries in the present disclosure are not particularly limited, and examples include 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, the batteries are preferably used as driving power sources for hybrid electric vehicles, plug-in hybrid electric vehicles, or electric vehicles. The batteries in the present 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 appliances such as information processing devices.

[0060] The present disclosure is not limited to the above-described embodiment. The above-described embodiment is merely an example, and any configuration that is substantially the same as the technical idea described in the claims of the present disclosure and that exhibits similar effects is included in the technical scope of the present disclosure. EXAMPLES

[0061] [Experimental Example 1] As shown in FIG. 6(a), a test sample having an elastic sheet, metal foil, and a positive electrode layer in this order was prepared. Then, as shown in FIG. 6(b), the test sample was placed on a base, and a loading tool was placed at a position 50 mm from the end of the coated portion in the longitudinal direction of the test sample to press it. After pressing, the distance (warping amount) by which the test sample moved away from the base was measured. In addition, the elongation rate of the metal foil and the positive electrode layer was measured before and after pressing. The results are shown in Table 1. A PET sheet with a thickness of 580 μm was used as the elastic sheet. The pressing pressure was a linear pressure of 0.35 ton / cm (one-sided load: 8.5 kN). The density of the positive electrode layer was 1.90 mg / cm. 3 The thickness of the positive electrode layer after pressing was 380 μm.

[0062] [Experimental Example 2] The amount of warping was measured in the same manner as in Experimental Example 1, except that no elastic sheet was used. The results are shown in Table 1. The density of the positive electrode layer was 1.93 mg / cm 3 The thickness of the positive electrode layer after pressing was 378 μm.

[0063] [Table 1]

[0064] As shown in Table 1, in Experimental Example 2, the positive electrode layer was stretched but the metal foil was not stretched, and the difference in the elongation rate between the two was large. This resulted in a large amount of warping. On the other hand, in Experimental Example 1, the difference in the elongation rate between the two was small, and as a result, the amount of warping was small. From these results, it was confirmed that the occurrence of warping in the electrode can be suppressed by using an elastic sheet for roll pressing. [Explanation of symbols]

[0065] 1...Metal foil 2 … Coating section 2A…1st coating section 2B: 2nd Coating Section 2C…Third Coating Department 3 … Uncoated area 10 ... Precursor sheet 10A ... First precursor sheet 10B ... second precursor sheet 20...Roll 20A…Roll A 20B…Roll B 21 ... Shaft body 22...Elastic body

Claims

1. a preparation step of preparing a second precursor sheet having a metal foil having a longitudinal direction in a first direction, a second coated portion disposed on a first surface of the metal foil, and a third coated portion disposed on a second surface of the metal foil opposite to the first surface; a coated portion pressing step of pressing the second coated portion and the third coated portion in a thickness direction while transporting the second precursor sheet in the first direction; having The second coating section contains an electrode material B, The third coating section contains an electrode material C, the third coated portion has a lower elongation in the first direction than the second coated portion; In the coating section pressing step, a pair of rolls, a roll A and a roll B, are used to roll-press the second coated portion and the third coated portion while pressing them in the thickness direction; During the roll press, the roll A is disposed on the second coated portion side of the second precursor sheet in the thickness direction; the roll B is disposed on the third coated portion side of the second precursor sheet in the thickness direction; and an elastic sheet is placed between the third coating unit and the roll B, and the roll pressing is performed.

2. The method for producing an electrode according to claim 1 , wherein the electrode material B comprises a positive electrode active material, and the electrode material C comprises a negative electrode active material.

3. 3. The method for manufacturing an electrode according to claim 1, wherein the roll A and the roll B are elastic rolls each having a shaft body and an elastic body covering the shaft body.

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