US-20260128274-A1 - ELECTRODE SHEET MANUFACTURING DEVICE AND METHOD FOR MANUFACTURING ELECTRODE SHEET

US20260128274A1US 20260128274 A1US20260128274 A1US 20260128274A1US-20260128274-A1

Abstract

An electrode sheet manufacturing device includes a conveyance device, a first press device, a second press device, and a stepped roll pressing device. The first press device is a device that roll-presses a non-formed portion of an electrode sheet by a pair of rubber rolls. At least one of the pair of rubber rolls includes a shaft and an elastic body. A diameter of the shaft in a portion thereof that presses a boundary portion between the non-formed portion and the electrode active material layer is larger than a diameter of the shaft in a portion thereof that presses a more outer side than the boundary portion. A thickness of the elastic body in the portion thereof that presses the boundary portion is smaller than a thickness of the elastic body in the portion thereof that presses the more outer side than the boundary portion.

Inventors

Daichi UMINO
Haruya Nakai

Assignees

Prime Planet Energy & Solutions, Inc.

Dates

Publication Date: 20260507
Application Date: 20251031
Priority Date: 20241107

Claims (14)

1 . An electrode sheet manufacturing device that manufactures an electrode sheet including a current collector formed of a long metal foil, a non-formed portion set along a length direction in a preset position of the current collector in a width direction, and an electrode active material layer formed in a portion of the current collector excluding the non-formed portion, the electrode sheet manufacturing device comprising: a conveyance device that conveys the electrode sheet along a preset conveyance path; a first press device that is arranged on the conveyance path and roll-presses the non-formed portion of the electrode sheet by a pair of rubber rolls; a second press device that is arranged at a downstream side of the first press device on the conveyance path and roll-presses the electrode active material layer; and a stepped roll pressing device that is arranged at a downstream side of the second press device on the conveyance path and presses a stepped roll against the non-formed portion of the electrode sheet to apply a tension thereto, wherein the stepped roll includes a step in a portion thereof that contacts a boundary portion of the non-formed portion that is a boundary with the electrode active material layer and a diameter of a portion thereof that contacts the non-formed portion is larger than a diameter of a portion thereof that contacts the electrode active material layer, at least one of the pair of rubber rolls includes a shaft and an elastic body wound around the shaft, in the at least one of the pair of rubber rolls, a diameter of the shaft in a portion thereof that presses the boundary portion between the non-formed portion and the electrode active material layer is larger than a diameter of the shaft in a portion thereof that presses a more outer side than the boundary portion, and a thickness of the elastic body in the portion thereof that presses the boundary portion is smaller than a thickness of the elastic body in the portion thereof that presses the more outer side than the boundary portion.
2 . The electrode sheet manufacturing device according to claim 1 , wherein the tension applied to the non-formed portion when the stepped roll is pressed against the non-formed portion is smaller than a tension applied to the non-formed portion at front and behind the pair of the rubber roll.
3 . The electrode sheet manufacturing device according to claim 1 , wherein the at least one of the pair of rubber rolls includes a first portion that presses the boundary portion, and a second portion and a third portion that press the more outer portion than the boundary portion, in the first portion, the thickness of the elastic body is constant, in the second portion, the thickness of the elastic body gradually increases from an end portion of the first portion toward an outer side in an axial direction, and in the third portion, the thickness of the elastic body is constant from an end portion of the second portion toward the outer side in the axial direction.
4 . The electrode sheet manufacturing device according to claim 3 , wherein the at least one of the pair of rubber rolls is arranged in a position where an inner end portion thereof corresponds to an end portion of the electrode active material layer, the first portion covers the boundary portion, a length of the second portion is smaller than a width of the non-formed portion, and a combined length of the first portion and the second portion is 0.6 times a width along which the electrode sheet and the at least one of the pair of rubber rolls overlap or more and 0.85 times the width or less.
5 . The electrode sheet manufacturing device according to claim 3 , wherein a length along which the at least one of the pair of rubber rolls is pressed against at least one of the electrode sheet and the other one of the pair of rubber rolls is 1.2 times a width along which the non-formed portion is pressed by the pair of rubber rolls or more and 2.1 times the width or less.
6 . The electrode sheet manufacturing device according to claim 5 , wherein in the second portion, the elastic body is inclined at an angle of 10 degrees or more and 25 degrees or less such that the thickness thereof increases from the end portion of the first portion toward the outer side in the axial direction.
7 . The electrode sheet manufacturing device according to claim 5 , wherein the thickness of the elastic body in the third portion is 1.3 times the thickness of the elastic body in the first portion or more and 2.0 times the thickness of the elastic body in the first portion or less.
8 . A method for manufacturing an electrode sheet including a current collector formed of a long metal foil, a non-formed portion set along a length direction in a preset position of the current collector in a width direction, and an electrode active material layer formed in a portion of the current collector excluding the non-formed portion, the method comprising: a first pressing step of roll-pressing the non-formed portion of the electrode sheet by a pair of rubber rolls while conveying the electrode sheet along a preset conveyance path; a second pressing step of roll-pressing the electrode active material layer after the first pressing step; and a stepped roll pressing step of pressing a stepped roll against the non-formed portion of the electrode sheet to apply a tension thereto after the first pressing step, wherein the stepped roll includes a step in a portion thereof that contacts a boundary portion of the non-formed portion that is a boundary with the electrode active material layer and a diameter of a portion thereof that contacts the non-formed portion is larger than a diameter of a portion thereof that contacts the electrode active material layer, at least one of the pair of rubber rolls includes a shaft and an elastic body wound around the shaft, in the at least one of the pair of rubber rolls, a diameter of the shaft in a portion thereof that presses the boundary portion between the non-formed portion and the electrode active material layer is larger than a diameter of the shaft in a portion thereof that presses a more outer side than the boundary portion, and a thickness of the elastic body in the portion thereof that presses the boundary portion is smaller than a thickness of the elastic body in the portion thereof that presses the more outer side than the boundary portion.
9 . The method for manufacturing an electrode sheet according to claim 8 , wherein in the stepped roll pressing step, the tension applied to the non-formed portion when the stepped roll is pressed against the non-formed portion is caused to be smaller than a tension applied to the non-formed portion at front and behind the pair of the rubber roll.
10 . The method for manufacturing an electrode sheet according to claim 8 , wherein the at least one of the pair of rubber rolls includes a first portion that presses the boundary portion, and a second portion and a third portion that press the more outer portion than the boundary portion, in the first portion, the thickness of the elastic body is constant, in the second portion, the thickness of the elastic body gradually increases from an end portion of the first portion toward an outer side in an axial direction, and in the third portion, the thickness of the elastic body is constant from an end portion of the second portion toward the outer side in the axial direction.
11 . The method for manufacturing an electrode sheet according to claim 10 , wherein the at least one of the pair of rubber rolls is arranged in a position where an inner end portion thereof corresponds to an end portion of the electrode active material layer, the first portion covers the boundary portion, a length of the second portion is smaller than a width of the non-formed portion, and a combined length of the first portion and the second portion is 0.6 times a width along which the electrode sheet and the at least one of the pair of rubber rolls overlap or more and 0.85 times the width or less.
12 . The method for manufacturing an electrode sheet according to claim 10 , wherein a length along which the at least one of the pair of rubber rolls is pressed against at least one of the electrode sheet and the other one of the pair of rubber rolls is 1.2 times a width along which the non-formed portion is pressed by the pair of rubber rolls or more and 2.1 times the width or less.
13 . The method for manufacturing an electrode sheet according to claim 12 , wherein in the second portion, the elastic body is inclined at an angle of 10 degrees or more and 25 degrees or less such that the thickness thereof increases from the end portion of the first portion toward the outer side in the axial direction.
14 . The method for manufacturing an electrode sheet according to claim 12 , wherein the thickness of the elastic body in the third portion is 1.3 times the thickness of the elastic body in the first portion or more and 2.0 times the thickness of the elastic body in the first portion or less.

Description

CROSS REFERENCE OF RELATED APPLICATION The present application claims priority from Japanese Patent Application No. 2024-194837 filed on November 7, 2024, which is incorporated by reference herein in its entirety. BACKGROUND The present disclosure relates to an electrode sheet manufacturing device and a method for manufacturing an electrode sheet. Japanese Laid-open Patent Publication No. 2023-036089 discloses a method for manufacturing an electrode, the method including a coated portion pressing step of pressing a coated portion provided on a metal foil in a thickness direction and a non-coated portion pressing step of pressing a non-coated portion in the thickness direction. SUMMARY Incidentally, the present inventors found that there is a phenomenon that, in roll-pressing the electrode sheet, even when the non-coated portion is pressed by a pair of elastic rolls, wrinkles are generated in the electrode sheet. An electrode sheet manufacturing device disclosed herein is a manufacturing device that manufactures an electrode sheet including a current collector, a non-formed portion, and an electrode active material layer. The current collector is formed of a long metal foil. The non-formed portion is set along a length direction in a preset position of the current collector in a width direction. The electrode active material layer is formed in a portion of the current collector excluding the non-formed portion. The electrode sheet manufacturing device includes a conveyance device, a first press device, a second press device, and a roll pressing device. The conveyance device conveys the electrode sheet along a preset conveyance path. The first press device is arranged on the conveyance path and roll-presses the non-formed portion of the electrode sheet by a pair of rubber rolls. The second press device is arranged at a downstream side of the first press device on the conveyance path and roll-presses the electrode active material layer. The stepped roll pressing device is arranged at a downstream side of the second press device on the conveyance path and presses a stepped roll against the non-formed portion of the electrode sheet to apply a tension thereto. The stepped roll includes a step in a portion thereof that contacts a boundary portion of the non-formed portion that is a boundary with the electrode active material layer. In the stepped roll, a diameter of a portion thereof that contacts the non-formed portion is larger than a diameter of a portion thereof that contacts the electrode active material layer. At least one of the pair of rubber rolls includes a shaft and an elastic body wound around the shaft. In the at least one of the pair of rubber rolls, a diameter of the shaft in a portion thereof that presses the boundary portion between the non-formed portion and the electrode active material layer is larger than a diameter of the shaft in a portion thereof that presses a more outer side than the boundary portion. In the at least one of the pair of rubber rolls, a thickness of the elastic body in the portion thereof that presses the boundary portion is smaller than a thickness of the elastic body in the portion thereof that presses the more outer side than the boundary portion. According to the electrode sheet manufacturing device described above, wrinkles of the electrode sheet are likely to be suppressed. BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a flowchart of manufacturing in a method for manufacturing an electrode sheet. FIG. 2 is a schematic view of an electrode sheet 10. FIG. 3 is a schematic view illustrating another embodiment of the electrode sheet 10. FIG. 4 is a schematic view illustrating an example of a roll-pressing step S6 proposed herein. FIG. 5 is a schematic view of a first press device 104. FIG. 6 is a schematic view illustrating a stepped roll pressing step S6c. FIG. 7 is a schematic view illustrating stretch of the electrode sheet 10 that is roll-pressed in a first pressing step S6a. FIG. 8 is a schematic view illustrating stretch of a current collector 12. DETAILED DESCRIPTION OF THE EMBODIMENTS Embodiments of a technology disclosed herein will be described below with reference to the accompanying drawings. As a matter of course, the embodiments described herein are not intended to be particularly limiting the present disclosure. The accompanying drawings are schematic and do not necessarily reflect actual members or portions. Members/portions that have the same effect will be denoted by the same sign as appropriate, and the overlapping description will be omitted as appropriate. As used herein, the expression “X to Y” that indicates a numerical value range means “equal to or more than X and equal to or less than Y,” unless specifically stated otherwise. FIG. 1 is a flowchart of manufacturing in a method for manufacturing an electrode sheet. As illustrated in FIG. 1, the method for manufacturing an electrode sheet includes a conveying step S1, a measuring step S2, a kneading s