Method for manufacturing an electrode body

Abstract

To provide a method for manufacturing an electrode body which can prevent a positive electrode and a negative electrode from being shifted in a direction perpendicular to a lamination direction.SOLUTION: A method for manufacturing an electrode body includes: a lamination step of alternately laminating a plurality of positive electrode units 111 each including a first resin part 11, a second resin part 12, a positive electrode 110 and a bag separator 131, and a plurality of negative electrodes 120; a first cutting step of cutting the plurality of first resin parts 11 together with the bag separator along a lamination direction; a second cutting step of cutting the plurality of second resin parts 12 together with the bag separator along the lamination direction; a first welding step of welding the pair of first resin parts 11 adjacent to each other in the lamination direction; and a second welding step of welding the pair of second resin parts 12 adjacent to each other in the lamination direction.SELECTED DRAWING: Figure 3

Description

Technical Field

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

Background Art

[0002] International Publication No. 2018 / 021263 discloses a method for manufacturing an electrode body in which a laminate in which a first separator and a second separator are adhered to both sides of a negative electrode sheet and a positive electrode sheet are alternately laminated to form an electrode body.

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 described in International Publication No. 2018 / 021263, after the formation of the electrode body, the laminate and the positive electrode sheet may shift relative to each other in a direction orthogonal to the lamination direction.

[0005] An object of the present disclosure is to provide a method for manufacturing an electrode body capable of suppressing the relative shift of the positive electrode and the negative electrode in a direction orthogonal to the lamination direction.

Means for Solving the Problems

[0006] According to one aspect of the present disclosure, a method for manufacturing an electrode body includes a plurality of positive electrode units, each of the positive electrode units including a first resin part, a second resin part, a positive electrode disposed between the first resin part and the second resin part, and a bag separator formed in a bag shape having an opening and accommodating the first resin part, the second resin part, and the positive electrode; a lamination step of forming a laminated electrode body by alternately laminating the positive electrode units and a plurality of negative electrode electrodes; a first cutting step of cutting the plurality of first resin parts arranged side by side in the lamination direction of the positive electrode units and the negative electrode electrodes together with the bag separator along the lamination direction; a second cutting step of cutting the plurality of second resin parts arranged side by side in the lamination direction together with the bag separator along the lamination direction; a first welding step of welding a pair of adjacent first resin parts among the plurality of first resin parts to each other in the lamination direction; and a second welding step of welding a pair of adjacent second resin parts among the plurality of second resin parts to each other in the lamination direction.

Advantages of the Invention

[0007] According to the present disclosure, it is possible to provide a method for manufacturing an electrode body that can suppress the displacement of a positive electrode and a negative electrode from each other in a direction orthogonal to the lamination direction.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Embodiments for Carrying Out the Invention

[0009] Embodiments of the present disclosure will be described with reference to the drawings. In the drawings referred to below, the same or corresponding members are given the same numbers.

[0010] FIG. 1 is a perspective view schematically showing a power storage cell according to an embodiment of the present disclosure. FIG. 2 is a cross-sectional view of the power storage cell shown in FIG. 1.

[0011] As shown in FIGS. 1 and 2, the power storage cell 1 includes 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 includes a plurality of electrodes 110 and 120 (see FIGS. 3 to 5) and a separator 130.

[0013] The plurality of electrodes 110 and 120 are arranged so as to be aligned in one direction (a direction perpendicular to the plane of the paper in FIG. 2). The plurality of electrodes 110 and 120 include a plurality of positive electrodes 110 and a plurality of negative electrodes 120.

[0014] Each positive electrode 110 is formed in a rectangular shape that is long in the width direction (a direction perpendicular to both the one direction and the vertical direction). Each positive electrode 110 has a positive current collector foil and positive active material layers provided on both sides of the positive current collector foil. As shown in FIG. 2, the positive current collector foil has a positive tab 112p on which no positive active material layer is provided. The positive tab 112p protrudes toward one side in the width direction.

[0015] Each negative electrode 120 is formed in a rectangular shape that is long in the width direction. Each negative electrode 120 has a negative current collector foil and negative active material layers provided on both sides of the negative current collector foil. As shown in FIG. 2, the negative current collector foil has a negative tab 122n on which no negative active material layer is provided. The negative 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.

[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 square 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 central portion of the lid 220. The pressure relief valve 222 is formed 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 inside the cell case 200 is discharged to the outside of the cell case 200 through the pressure relief valve 222, so 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 the 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 a rectangular parallelepiped shape, for example. 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 collecting tab 410, a sub-tab 420, and a connecting pin 430.

[0025] The current collecting 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 inward in the width direction from the upper end of the side portion 412.

[0026] The sub-tab 420 connects a plurality of positive electrode tabs 112p to the current collecting tab 410. One end 422 of the sub-tab 420 is connected to the plurality of 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 collecting tab 410 by welding or the like.

[0027] The connecting pin 430 connects the current collecting tab 410 and the external terminal 300. The connecting pin 430 connects the upper portion 414 and the external terminal 300. Specifically, the lower end portion of the connecting pin 430 is connected to the upper portion 414 by welding or the like while being inserted into the through hole provided in the upper portion 414, and the upper end portion of the connecting pin 430 is connected to the external terminal 300 by welding, caulking or the like while being inserted into the through hole provided in the external terminal 300.

[0028] The insulating member 500 insulates between the cell case 200 and 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 disposed 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 disposed 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 disposed between the connecting pin 430 and the lid 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 disposed 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 in the portion located below the liquid injection port h.

[0033] Next, with reference to FIGS. 3 to 5 and the like, the manufacturing process of the electrode body 100 will be described. The manufacturing method of the electrode body 100 includes a lamination process, a first cutting process, a second cutting process, a first welding process, and a second welding process.

[0034] In the lamination process, a plurality of positive electrode units 111 and a plurality of negative electrodes 120 are alternately laminated. As shown in FIG. 3, each positive electrode unit 111 includes a first resin portion 11, a second resin portion 12, a positive electrode 110, and a bag separator 131. Note that FIG. 3 shows the state after the lamination process.

[0035] The first resin portion 11 and the second resin portion 12 may be formed of the same resin as each other or may be formed of different resins from each other. The length of each of the resin portions 11 and 12 in the arrangement direction (the left - right direction in FIG. 3) is shorter than the length of the positive electrode 110 in the arrangement direction. The thickness of each of the resin portions 11 and 12 is the same as or smaller than the thickness of the positive electrode 110.

[0036] The positive electrode 110 is disposed between the first resin portion 11 and the second resin portion 12. The end portions of the positive electrode 110 in the arrangement direction may be in contact with each of the resin portions 11 and 12 or may be spaced apart from each of the resin portions 11 and 12.

[0037] The bag separator 131 is formed in a bag shape having an opening 132. The bag separator 131 houses the first resin portion 11, the second resin portion 12, and the positive electrode 110 such that the positive electrode 110 is disposed between the first resin portion 11 and the second resin portion 12. It is preferable that the second resin portion 12 is in contact with the folded - back portion of the bag separator 131 so that the positioning of the second resin portion 12 with respect to the bag separator 131 is performed.

[0038] In the first cutting step, a plurality of first resin parts 11 arranged side by side in the stacking direction of the positive electrode unit 111 and the negative electrode 120 are cut along the stacking direction together with the bag separator 131. In FIG. 3, the part cut in the first cutting step is indicated by a dashed-dotted line L1.

[0039] In the second cutting step, a plurality of second resin parts 12 arranged side by side in the stacking direction are cut along the stacking direction together with the bag separator 131. In FIG. 3, the part cut in the second cutting step is indicated by a dashed-dotted line L2. FIG. 4 shows the state after the first cutting step and the second cutting step. The separator 130 is formed by the bag separator 131 undergoing the first cutting step and the second cutting step.

[0040] In the first welding step, a pair of adjacent first resin parts 11 among the plurality of first resin parts 11 in the stacking direction are welded together. In the first welding step, the pair of first resin parts 11 are heated by a heating means (not shown). Thereby, the melted first resin parts 11 are welded together. In the first welding step, the pair of first resin parts 11 are welded together so that the first resin part 11 contacts the negative electrode 120 positioned between the pair of first resin parts 11.

[0041] In the second welding step, a pair of adjacent second resin parts 12 among the plurality of second resin parts 12 in the stacking direction are welded together. In the second welding step, the second resin parts 12 are heated in the same manner as in the first welding step. In the second welding step, the pair of second resin parts 12 are welded together so that the second resin part 12 contacts the negative electrode 120 positioned between the pair of second resin parts 12. Note that FIG. 5 shows the state after the first welding step and the second welding step.

[0042] As described above, in the method for manufacturing the electrode body 100 according to the present embodiment, by using the bag separator 131, the first resin portion 11, the positive electrode 110, and the second resin portion 12 are effectively positioned. Further, since the pair of first resin portions 11 arranged so as to sandwich the negative electrode 120 in the stacking direction and the pair of second resin portions 12 are welded together, the positive electrode 110 and the negative electrode 120 are suppressed from shifting from each other in a direction orthogonal to the stacking direction.

[0043] It is understood by those skilled in the art that the above-described exemplary embodiments are specific examples of the following aspects.

[0044] [Aspect 1] A plurality of positive electrode units, each of the positive electrode units including a first resin portion, a second resin portion, a positive electrode disposed between the first resin portion and the second resin portion, and a bag separator formed in a bag shape having an opening and accommodating the first resin portion, the second resin portion, and the positive electrode, and a plurality of negative electrodes, and a stacking step of alternately stacking the positive electrode units and the negative electrodes; A first cutting step of cutting the plurality of first resin portions arranged side by side in the stacking direction of the positive electrode unit and the negative electrode together with the bag separator along the stacking direction; A second cutting step of cutting the plurality of second resin portions arranged side by side in the stacking direction together with the bag separator along the stacking direction; A first welding step of welding a pair of adjacent first resin portions among the plurality of first resin portions in the stacking direction; A second welding step of welding a pair of adjacent second resin portions among the plurality of second resin portions in the stacking direction, the method for manufacturing an electrode body comprising the steps.

[0045] In this method for manufacturing an electrode body, by using the bag separator, the first resin portion, the positive electrode, and the second resin portion are effectively positioned. Further, since the pair of first resin portions arranged so as to sandwich the negative electrode in the stacking direction and the pair of second resin portions are welded together, the positive electrode and the negative electrode are suppressed from shifting from each other in a direction orthogonal to the stacking direction.

[0046] [Aspect 2] In the first welding step, the pair of first resin parts are welded to each other such that the first resin part contacts the negative electrode. The method for manufacturing an electrode body according to Aspect 1, wherein in the second welding step, the pair of second resin parts are welded to each other such that the second resin part contacts the negative electrode.

[0047] In this aspect, it is more reliably suppressed that the positive electrode and the negative electrode shift from each other in a direction orthogonal to the stacking direction.

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

Explanation of Reference Numerals

[0049] 1 Power storage cell, 11 First resin part, 12 Second resin part, 100 Electrode body, 110 Positive electrode, 111 Positive electrode unit, 112 Positive current collector foil, 112p Positive tab, 114 Positive electrode active material layer, 120 Negative electrode, 122 Negative current collector foil, 122n Negative tab, 130 Separator, 131 Bag separator, 132 Opening, 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 part, 520 Lower insulating part, 530 Insulator, 540 Insulating plate.

Claims

1. A plurality of positive electrode units, each of the positive electrode units including a first resin part, a second resin part, a positive electrode disposed between the first resin part and the second resin part, and a bag separator formed in a bag shape having an opening and accommodating the first resin part, the second resin part, and the positive electrode; and a plurality of negative electrode electrodes; a lamination step of alternately laminating the positive electrode units and the negative electrode electrodes; a first cutting step of cutting the plurality of first resin parts arranged side by side in the lamination direction of the positive electrode unit and the negative electrode electrode together with the bag separator along the lamination direction; a second cutting step of cutting the plurality of second resin parts arranged side by side in the lamination direction together with the bag separator along the lamination direction; a first welding step of welding a pair of adjacent first resin parts in the lamination direction among the plurality of first resin parts; a second welding step of welding a pair of adjacent second resin parts in the lamination direction among the plurality of second resin parts; a method for manufacturing an electrode body.

2. In the first welding step, the pair of first resin parts are welded so that the first resin part contacts the negative electrode electrode. In the second welding step, the pair of second resin parts are welded so that the second resin part contacts the negative electrode electrode. The method for manufacturing an electrode body according to claim 1.

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