Method for manufacturing electrodes

Abstract

To provide a method for manufacturing an electrode body which can suppress positional displacement of an electrode from a separator while reducing the number of steps necessary to manufacture a plurality of electrodes.SOLUTION: A method for manufacturing an electrode 100 includes the steps of: preparing a separator 130; arranging a plurality of positive electrodes 110 on the separator; forming a folding unit 132 for determining the positions of the positive electrodes with respect to the separator by folding back the separator and arranging the separator on the positive electrodes; arranging a plurality of negative electrodes 120 on the separator arranged on the positive electrodes; forming a folding unit 132 for determining the positions of the negative electrodes with respect to the separator by folding back the separator and arranging the separator on the negative electrodes; and cutting the separator in a position which passes among the positive electrodes and among the negative electrodes, thereby forming a plurality of electrode bodies 100.SELECTED DRAWING: Figure 6

Description

Technical Field

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

Background Art

[0002] Japanese Patent Application Laid-Open No. 2021-57217 discloses a process for producing a unit by forming a welded portion between a plurality of electrodes by welding together a pair of separator sheets with the plurality of electrodes disposed therebetween, a process for producing a laminated unit by laminating a plurality of the units, and a process for producing a plurality of electrode assemblies by cutting the laminated unit at the welded portion.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In the method for manufacturing an electrode body as described in Japanese Patent Application Laid-Open No. 2021-57217, the electrodes may shift with respect to the separator during lamination of the units or the like.

[0005] An object of the present disclosure is to provide a method for manufacturing an electrode body capable of suppressing displacement of the electrodes with respect to the separator while reducing the man-hours required for manufacturing a plurality of electrode bodies.

Means for Solving the Problems

[0006] A method for manufacturing an electrode body according to one aspect of the present disclosure is a method for manufacturing an electrode body in which a positive electrode and a negative electrode are arranged side by side with a separator in between, comprising the steps of: preparing the separator; arranging a plurality of the positive electrodes on the separator; forming a folded portion for positioning the positive electrodes relative to the separator by folding the separator back, and arranging the separator on the plurality of positive electrodes; arranging a plurality of the negative electrodes on the separator arranged on the plurality of positive electrodes; forming a folded portion for positioning the negative electrodes relative to the separator by folding the separator back, and arranging the separator on the plurality of negative electrodes; and forming a plurality of the electrode bodies by cutting the separator at a position passing between the plurality of positive electrodes and between the plurality of negative electrodes. [Effects of the Invention]

[0007] According to this disclosure, it is possible to provide a method for manufacturing electrode bodies that can reduce the number of steps required to manufacture multiple electrode bodies while suppressing misalignment of the electrodes relative to the separator. [Brief explanation of the drawing]

[0008] [Figure 1] This is a schematic perspective view of an energy storage cell in one embodiment of the present disclosure. [Figure 2] Figure 1 is a cross-sectional view of the energy storage cell. [Figure 3] This diagram schematically shows the manufacturing method of the electrode body. [Figure 4] This diagram schematically shows the manufacturing method of the electrode body. [Figure 5] This diagram schematically shows the manufacturing method of the electrode body. [Figure 6] This diagram schematically shows the manufacturing method of the electrode body. [Modes for carrying out the invention]

[0009] Embodiments of this disclosure will be described with reference to the drawings. In the drawings referred to below, the same or equivalent components are given the same number.

[0010] Figure 1 is a schematic perspective view of an energy storage cell in one embodiment of the present disclosure. Figure 2 is a cross-sectional view of the energy storage cell shown in Figure 1.

[0011] As shown in Figures 1 and 2, the energy storage cell 1 comprises an electrode body 100, a cell case 200, a pair of external terminals 300, a pair of connecting members 400, and an insulating member 500.

[0012] The electrode body 100 comprises a plurality of electrodes 110, 120 (see Figure 6, etc.) and a separator 130.

[0013] Multiple electrodes 110, 120 are arranged in a unidirectional direction (a direction perpendicular to the plane of the paper in Figure 2). Each of the multiple electrodes 110, 120 comprises multiple positive electrodes 110 and multiple negative electrodes 120.

[0014] Each positive electrode 110 is formed in a rectangular shape that is elongated in the width direction (a direction perpendicular to both the unidirectional and vertical directions). Each positive electrode 110 has a positive electrode current collector foil and a positive electrode active material layer provided on both sides of the positive electrode current collector foil. As shown in Figure 2, the positive electrode current collector foil has a positive electrode tab 112p on which the positive electrode active material layer is not provided. The positive electrode tab 112p protrudes toward one side in the width direction.

[0015] Each negative electrode 120 is formed in a rectangular shape that is elongated in the width direction. Each negative electrode 120 has a negative electrode current collector foil and a negative electrode active material layer provided on both sides of the negative electrode current collector foil. As shown in Figure 2, the negative electrode current collector foil has a negative electrode tab 122n on which the negative electrode active material layer is not provided. The negative electrode tab 122n protrudes toward the other side in the width direction.

[0016] The separator 130 insulates between the positive electrode 110 and the negative electrode 120. The separator 130 is made of an insulating material and has minute voids that allow the permeation of ions. The separator 130 may be formed in a zigzag shape. That is, the separator 130 may be arranged while being formed in a zigzag shape between the respective electrodes 110 and 120.

[0017] The cell case 200 houses the electrode body 100. An electrolytic solution (not shown in the figure) is housed in the cell case 200. The cell case 200 is sealed. The cell case 200 has a case body 210 and a lid 220.

[0018] The case body 210 has an opening that opens upward. The case body 210 is made of a metal such as aluminum. As shown in FIG. 2, the case body 210 has a bottom wall 212 and a peripheral wall 214. The bottom wall 212 is formed in a rectangular and flat plate shape. The peripheral wall 214 stands up from the bottom wall 212. The peripheral wall 214 is formed in a rectangular tube shape. The length of the peripheral wall 214 in the width direction is longer than the length of the peripheral wall 214 in the thickness direction. The length of the peripheral wall 214 in the height direction is longer than the length of the peripheral wall 214 in the thickness direction.

[0019] The lid 220 closes the opening of the case body 210. The lid 220 is connected to the opening by welding or the like. The lid 220 is formed in a flat plate shape. The lid 220 is made of a metal such as aluminum. The lid 220 has a pressure relief valve 222 and a sealing member 224.

[0020] The pressure relief valve 222 is formed at the center of the lid 220. The pressure relief valve 222 is formed so as to break when the internal pressure of the cell case 200 becomes a predetermined pressure or more. When the pressure relief valve 222 breaks, the gas in the cell case 200 is discharged to the outside of the cell case 200 through the pressure relief valve 222, so that the internal pressure of the cell case 200 decreases.

[0021] The sealing member 224 seals the liquid injection port h formed in the lid 220. The liquid injection port h is a through hole for injecting an electrolytic solution into the cell case 200 during the manufacturing process of the power storage cell 1. After the electrolytic solution is injected into the case body 210 through the liquid injection port h, the liquid injection port h is sealed by the sealing member 224.

[0022] The pair of external terminals 300 are fixed on the cell case 200. One of the pair of external terminals 300 is the external terminal of the positive electrode, and the other is the external terminal of the negative electrode. Each external terminal 300 is fixed to the upper surface of the lid 220 via the upper insulating portion 510 described later. Each external terminal 300 is made of a metal such as aluminum. Each external terminal 300 is formed in, for example, a rectangular parallelepiped shape. A bus bar (not shown) is connected to each external terminal 300 by welding or the like.

[0023] The pair of connecting members 400 connect the plurality of electrode tabs 112p, 122n and the external terminals 300. One connecting member 400 connects the plurality of positive electrode tabs 112p and the external terminal 300 of the positive electrode, and the other connecting member 400 connects the plurality of negative electrode tabs 122n and the external terminal 300 of the negative electrode. Since each of the pair of connecting members 400 has substantially the same structure as each other, one of the connecting members 400 will be described below.

[0024] The connecting member 400 has a current collector tab 410, a sub-tab 420, and a connecting pin 430.

[0025] The current collector tab 410 has a side portion 412 and an upper portion 414. The side portion 412 is located on the side of the electrode body 100 in the width direction. The upper portion 414 is located above the electrode body 100. The upper portion 414 extends from the upper end of the side portion 412 toward the inside in the width direction.

[0026] The sub-tab 420 connects multiple positive electrode tabs 112p to the current collection tab 410. One end 422 of the sub-tab 420 is connected to the multiple positive electrode tabs 112p by welding or the like, and the other end 424 of the sub-tab 420 is connected to the side portion 412 of the current collection tab 410 by welding or the like.

[0027] The connecting pin 430 connects the current collection tab 410 and the external terminal 300. The connecting pin 430 also connects the upper part 414 and the external terminal 300. Specifically, the lower end of the connecting pin 430 is inserted into a through hole provided in the upper part 414 and connected to the upper part 414 by welding or the like, and the upper end of the connecting pin 430 is inserted into a through hole provided in the external terminal 300 and connected to the external terminal 300 by welding, crimping or the like.

[0028] The insulating member 500 insulates the cell case 200 from the connecting member 400. The insulating member 500 has an upper insulating portion 510, a lower insulating portion 520, an insulator 530, and an insulating plate 540.

[0029] The upper insulating portion 510 is fixed to the upper surface of the lid 220. The upper insulating portion 510 is positioned between the lid 220 and the external terminal 300. The upper insulating portion 510 is provided with an insertion hole for inserting the connecting pin 430.

[0030] The lower insulating portion 520 is fixed to the lower surface of the lid 220. The lower insulating portion 520 is positioned between the lid 220 and the upper portion 414 and the lower part of the connecting pin 430. The lower insulating portion 520 is provided with an insertion hole for inserting the connecting pin 430.

[0031] The insulator 530 is positioned between the connecting pin 430 and the cover 220. The insulator 530 is formed in a cylindrical shape and surrounds the connecting pin 430.

[0032] The insulating plate 540 is fixed to the lower surface of the upper portion 414. The insulating plate 540 is positioned above the electrode body 100. Through holes are provided in the portion of the insulating plate 540 located below the pressure relief valve 222 and below the liquid injection port h.

[0033] Next, the manufacturing process of the electrode body 100 will be described with reference to Figures 3 to 6, etc. The manufacturing method of the electrode body 100 includes a preparation step, a positive electrode placement step, a folding step, a negative electrode placement step, and a cutting step.

[0034] In the preparation process, a long separator 130 is prepared.

[0035] In the positive electrode placement process, multiple positive electrodes 110 are arranged on the separator 130 so as to be spaced apart from each other. Figure 3 shows the state after the positive electrode placement process.

[0036] In the folding process, the separator 130 is folded back so that it is positioned on multiple positive electrodes 110. This creates a folded portion 132 on the separator 130. This folded portion 132 positions the positive electrodes 110 relative to the separator 130. In other words, in this process, the separator 130 is folded back to form a folded portion 132 that positions the positive electrodes 110 relative to the separator 130, and the separator 130 is positioned on multiple positive electrodes 110.

[0037] In the negative electrode placement process, multiple negative electrodes 120 are arranged on a separator 130 placed on multiple positive electrodes 110, spaced apart from each other. Figure 4 shows the state after the negative electrode placement process.

[0038] In the folding step of the negative electrode placement step, similar to the previous folding step, a folded portion 132 is formed by folding the separator 130 to position the negative electrode 120 relative to the separator 130, and the separator 130 is placed on multiple negative electrode 120s.

[0039] Subsequently, the positive electrode placement process, the folding process, and the negative electrode placement process are repeated in this order.

[0040] Then, the separator 130 is cut at a position passing between multiple positive electrodes 110 and multiple negative electrodes 120 (indicated by the dashed line L in Figure 6), thereby forming multiple electrode bodies 100.

[0041] As described above, in the manufacturing method of the electrode body 100 in this embodiment, each electrode 110 and 120 is positioned relative to the separator 130 by the folded portion 132 of the separator 130, thereby achieving both a reduction in the number of man-hours required to manufacture multiple electrode bodies 100 and suppression of misalignment of each electrode 110 and 120 relative to the separator 130.

[0042] In the above embodiment, an example was shown in which multiple positive electrodes 110 and multiple negative electrodes 120 are arranged in the direction connecting the folded portions 132 of the separator 130 (the left-right direction in Figure 6). However, the multiple positive electrodes 110 and multiple negative electrodes 120 may also be arranged in an orthogonal direction perpendicular to the direction connecting the folded portions 132 and the thickness direction of each electrode 110, 120 (the direction perpendicular to the plane of the paper in Figure 6). In this embodiment, after the cutting process, all electrodes 110, 120 are positioned in each electrode body 100 by the folded portions of the separator 130.

[0043] Those skilled in the art will understand that the exemplary embodiments described above are specific examples of the following embodiments.

[0044] [Aspect 1] A method for manufacturing an electrode body in which a positive electrode and a negative electrode are arranged side by side with a separator in between, The process of preparing the separator, The steps include: arranging a plurality of positive electrodes on the separator; The steps include: forming a folded portion for positioning the positive electrode relative to the separator by folding the separator back, and arranging the separator on the plurality of positive electrodes; A step of arranging a plurality of negative electrodes on a separator arranged on a plurality of positive electrodes, The steps include: forming a folded portion for positioning the negative electrode relative to the separator by folding the separator back, and arranging the separator on the plurality of negative electrodes; A method for manufacturing an electrode body, comprising the step of forming a plurality of electrode bodies by cutting the separator at a position passing through the plurality of positive electrodes and the plurality of negative electrodes.

[0045] In this electrode manufacturing method, each electrode is positioned relative to the separator by the folded portion of the separator, thus achieving both a reduction in the number of steps required to manufacture multiple electrode bodies and suppression of misalignment of the electrodes relative to the separator.

[0046] [Aspect 2] In the step of arranging the plurality of positive electrodes, the plurality of positive electrodes are arranged in an orthogonal direction that is perpendicular to both the direction connecting the folded portions and the thickness direction of the positive electrodes. The method for manufacturing an electrode body according to Embodiment 1, wherein in the step of arranging the plurality of negative electrodes, the plurality of negative electrodes are arranged so as to be aligned in the orthogonal direction.

[0047] In this embodiment, both the positive and negative electrodes are positioned by each folded portion.

[0048] It should be noted that the embodiments disclosed herein are illustrative in all respects and not restrictive. The scope of the present invention is indicated by the claims rather than the description of the embodiments above, and further includes all modifications within the meaning and scope equivalent to the claims. [Explanation of Symbols]

[0049] 1 Energy storage cell, 100 Electrode body, 110 Positive electrode, 112 Positive electrode current collector foil, 112p Positive electrode tab, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative electrode current collector foil, 122n Negative electrode tab, 130 Separator, 132 Folded section, 200 Cell case, 210 Case body, 220 Lid, 300 External terminal, 400 Connecting member, 410 Current collector tab, 420 Sub-tab, 430 Connecting pin, 500 Insulating member, 510 Upper insulating section, 520 Lower insulating section, 530 Insulator, 540 Insulating plate.

Claims

[Claim 1] A method for manufacturing an electrode body in which a positive electrode and a negative electrode are arranged side by side with a separator in between, The process of preparing the separator, The steps include: arranging a plurality of positive electrodes on the separator; The steps include: forming a folded portion for positioning the positive electrode relative to the separator by folding the separator back, and arranging the separator on the plurality of positive electrodes; A step of arranging a plurality of negative electrodes on a separator arranged on a plurality of positive electrodes, The steps include: forming a folded portion for positioning the negative electrode relative to the separator by folding the separator back, and arranging the separator on the plurality of negative electrodes; The process includes the step of forming a plurality of electrode bodies by cutting the separator at a position passing through the plurality of positive electrodes and the plurality of negative electrodes, In the step of arranging the plurality of positive electrodes, the plurality of positive electrodes are arranged in an orthogonal direction that is perpendicular to both the direction connecting the folded portions and the thickness direction of the positive electrodes. A method for manufacturing an electrode body, wherein in the step of arranging the plurality of negative electrodes, the plurality of negative electrodes are arranged so as to be aligned in the orthogonal direction.

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