JP2022078624A - Battery and manufacturing method of the same - Google Patents

Abstract

To provide a battery with high manufacturing efficiency and a manufacturing method of the same.SOLUTION: A battery includes an electrode body including a first laminated group and a second laminated group. The electrode body includes a positive electrode plate, a negative electrode plate, and a separator laminated with the positive electrode plate and the negative electrode plate. The positive electrode plate includes a first positive electrode body part included in the first laminated group, a second positive electrode body part included in the second laminated group, and a positive electrode tab connecting between the first positive electrode body part and the second positive electrode body part. The negative electrode plate includes a first negative electrode body part included in the first laminated group, a second negative electrode body part included in the second laminated group, and a negative electrode tab connecting between the first negative electrode body part and the second negative electrode body part. The first laminated group and the second laminated group are overlapped while the positive electrode tab and the negative electrode tab are bent.SELECTED DRAWING: Figure 9

Description

This technique relates to a battery and a method for manufacturing the same.

Conventionally, an electrode body formed by alternately laminating positive electrode plates and negative electrode plates has been known. Such a structure is described in, for example, Japanese Patent Application Laid-Open No. 2018-73679 (Patent Document 1).

Japanese Unexamined Patent Publication No. 2018-73679

When a plurality of electrode body elements are configured and stored in a battery case, if the electrode body elements are individually stored in the battery case, the manufacturing efficiency of the battery may decrease. The conventional structure is not always sufficient from the viewpoint of improving the manufacturing efficiency of the battery.
An object of the present technology is to provide a battery having high manufacturing efficiency and a manufacturing method thereof.

The battery according to the present technology includes an electrode body including a first laminated group and a second laminated group. The electrode body includes a positive electrode plate, a negative electrode plate, and a separator laminated with the positive electrode plate and the negative electrode plate. The positive electrode plate includes a first positive electrode main body included in the first laminated group, a second positive electrode main body included in the second laminated group, and a positive electrode tab connecting the first positive electrode main body and the second positive electrode main body. including. The negative electrode plate includes a first negative electrode main body included in the first laminated group, a second negative electrode main body included in the second laminated group, and a negative electrode tab connecting the first negative electrode main body and the second negative electrode main body. including. The first laminated group and the second laminated group are overlapped with the positive electrode tab and the negative electrode tab bent.

The method for manufacturing a battery according to the present technology is a step of manufacturing a positive electrode plate including a first positive electrode main body portion, a second positive electrode main body portion, and a positive electrode tab connecting the first positive electrode main body portion and the second positive electrode main body portion. A step of manufacturing a negative electrode plate including a first negative electrode main body portion, a second negative electrode main body portion, and a negative electrode tab connecting the first negative electrode main body portion and the second negative electrode main body portion, and a positive electrode plate and a negative electrode plate. By alternately laminating the positive electrode tabs and the negative electrode tabs through the separator, the first laminated group including the first positive electrode main body and the first negative electrode main body, the second positive electrode main body, and the second negative electrode main body. It is provided with a step of superimposing the second laminated group including the portion.

According to this technique, it is possible to provide a battery having high manufacturing efficiency and a manufacturing method thereof.

It is a perspective view of a square secondary battery. FIG. 2 is a cross-sectional view taken along the line II-II in FIG. It is a top view which shows the electrode body. It is a figure which shows the attachment structure of the positive electrode current collector member and the negative electrode current collector member to a sealing plate. FIG. 6 is a sectional view taken along line VV in FIG. FIG. 4 is a sectional view taken along line VI-VI in FIG. It is a top view which shows the electrode body in the manufacturing process. It is a side view of the electrode body in the manufacturing process shown in FIG. 7. It is a figure which shows the state which the electrode tab of the electrode body shown in FIGS. 7 and 8 is bent and two electrode body elements are overlapped. It is a figure which shows the connection part of the electrode body and the current collector which concerns on one example. It is a figure which shows the one which extracted the electrode body shown in FIG. It is a figure which shows the process of manufacturing a positive electrode plate. It is a figure which shows the process of manufacturing a negative electrode plate. It is a figure which shows the positive electrode plate manufactured through the process shown in FIG. It is a figure which shows the negative electrode plate manufactured through the process which shows FIG. It is a figure which shows an example of a separator. It is a figure which shows the modification of the separator.

Hereinafter, embodiments of the present technology will be described. In some cases, the same or corresponding parts are designated by the same reference numeral and the description thereof may not be repeated.

In the embodiments described below, when the number, quantity, etc. are referred to, the scope of the present technique is not necessarily limited to the number, quantity, etc., unless otherwise specified. Further, in the following embodiments, each component is not necessarily essential for the present technique unless otherwise specified.

In addition, in this specification, the description of "comprise", "include", and "have" is in an open-ended format. That is, it includes a certain configuration, but does not exclude the inclusion of other configurations other than the configuration.

FIG. 1 is a perspective view of the square secondary battery 1. FIG. 2 is a cross-sectional view taken along the line II-II in FIG.

As shown in FIGS. 1 and 2, the square secondary battery 1 includes a battery case 100, an electrode body 200, an electrode body holder 300, a positive electrode terminal 400, a negative electrode terminal 500, a positive electrode current collector 600, and the like. The negative electrode current collecting member 700 and the cover member 800 are included.

The battery case 100 includes a bottomed square cylinder-shaped square exterior body 110 having an opening, and a sealing plate 120 (sealing member) for sealing the opening of the square exterior body 110. The square exterior body 110 and the sealing plate 120 are preferably made of metal, and preferably made of aluminum or an aluminum alloy.

The sealing plate 120 is provided with an electrolytic solution injection hole 121. A non-aqueous electrolytic solution is injected into the battery case 100 from the electrolytic solution injection hole 121. As the non-aqueous electrolyte solution, for example, a non-aqueous solvent in which ethylene carbonate (EC), ethylmethyl carbonate (EMC), and diethyl carbonate (DEC) are mixed at a volume ratio (25 ° C.) of 30:30:40. In addition, LiPF ₆ dissolved at a concentration of 1.2 mol / L can be used.

After the non-aqueous electrolytic solution is injected into the battery case 100 from the electrolytic solution injection hole 121, the electrolytic solution injection hole 121 is sealed by the sealing member 122. As the sealing member 122, for example, a blind rivet and other metal members can be used.

The sealing plate 120 is provided with a gas discharge valve 123. The gas discharge valve 123 breaks when the pressure in the battery case 100 exceeds a predetermined value. As a result, the gas inside the battery case 100 is discharged to the outside of the battery case 100.

The electrode body 200 is housed in the battery case 100 together with the electrolytic solution. In the electrode body 200, positive electrode plates and negative electrode plates are alternately laminated via a separator. A resin electrode body holder 300 (insulator holder) is arranged between the electrode body 200 and the square exterior body 110.

A positive electrode tab 210A and a negative electrode tab 210B are provided at the end of the electrode body 200 on the sealing plate 120 side.

The positive electrode tab 210A and the positive electrode terminal 400 are electrically connected to each other via a positive electrode current collector member 600. The positive electrode current collector 600 includes a first positive electrode current collector 610 and a second positive electrode current collector 620. The positive electrode current collector member 600 may be composed of one component. The positive electrode current collector member 600 is preferably made of metal, and more preferably made of aluminum or an aluminum alloy.

The negative electrode tab 210B and the negative electrode terminal 500 are electrically connected via the negative electrode current collector member 700. The negative electrode current collector 700 includes a first negative electrode current collector 710 and a second negative electrode current collector 720. The negative electrode current collector 700 may be composed of one component. The negative electrode current collector 700 is preferably made of metal, more preferably copper or a copper alloy.

The positive electrode terminal 400 is fixed to the sealing plate 120 via a resin outer insulating member 410. The negative electrode terminal 500 is fixed to the sealing plate 120 via a resin outer insulating member 510.

The positive electrode terminal 400 is preferably made of metal, more preferably aluminum or an aluminum alloy. The negative electrode terminal 500 is preferably made of metal, more preferably copper or a copper alloy. The negative electrode terminal 500 may have a region made of copper or a copper alloy arranged on the inner side of the battery case 100 and a region made of aluminum or an aluminum alloy arranged on the outer side of the battery case 100.

The cover member 800 (insulator) is provided between the electrode body 200 and the sealing plate 120. The cover member 800 suppresses an unintended electrical short circuit around the electrode body 200. Details such as the shape of the cover member 800 will be described later.

FIG. 3 is a plan view showing the electrode body 200. The electrode body 200 has a main body portion 210, a positive electrode tab 210A, and a negative electrode tab 210B.

FIG. 4 is a diagram showing an attachment structure of the positive electrode current collector member 600 and the negative electrode current collector member 700 to the sealing plate 120. FIG. 5 shows a VV cross section in FIG. FIG. 6 shows a VI-VI cross section in FIG.

First, the attachment of the positive electrode current collector member 600 to the sealing plate 120 will be described with reference to FIGS. 4 and 5.

An external insulating member 410 made of resin is arranged on the outer surface side of the sealing plate 120. A first positive electrode current collector 610 and a resin insulating member 630 (positive electrode current collector holder) are arranged on the inner surface side of the sealing plate 120. Next, the positive electrode terminal 400 is inserted into a through hole of the external insulating member 410, a positive electrode terminal mounting hole of the sealing plate 120, a through hole of the first positive electrode current collector 610, and a through hole of the insulating member 630. Then, the caulking portion 400A located at the tip of the positive electrode terminal 400 is caulked and connected onto the first positive electrode current collector 610. As a result, the positive electrode terminal 400, the external insulating member 410, the sealing plate 120, the first positive electrode current collector 610, and the insulating member 630 are fixed. The portions of the positive electrode terminal 400 and the first positive electrode current collector 610 that are caulked and connected are preferably welded and connected by laser welding or the like.

Further, the second positive electrode current collector 620 is arranged on the insulating member 630 so that a part of the second positive electrode current collector 620 overlaps with the first positive electrode current collector 610. In the first opening 620A provided in the second positive electrode current collector 620, the second positive electrode current collector 620 is welded and connected to the first positive electrode current collector 610 by laser welding or the like.

As shown in FIG. 5, the insulating member 630 has a cylindrical portion 630A protruding toward the electrode body 200. The tubular portion 630A defines a hole portion 630B that penetrates the second opening 620B of the second positive electrode current collector 620 and the positive electrode tab 210A and communicates with the electrolytic solution injection hole 121.

When attaching the positive electrode current collector 600 to the sealing plate 120, first, the first positive electrode current collector 610 is connected to the insulating member 630 on the sealing plate 120. Subsequently, the second positive electrode current collector 620 connected to the electrode body 200 is attached to the first positive electrode current collector 610. At this time, the second positive electrode current collector 620 is arranged on the insulating member 630 so that a part of the second positive electrode current collector 620 overlaps with the first positive electrode current collector 610. Subsequently, the periphery of the first opening 620A provided in the second positive electrode current collector 620 is welded and connected to the first positive electrode current collector 610 by laser welding or the like.

Next, the attachment of the negative electrode current collector 700 to the sealing plate 120 will be described with reference to FIGS. 4 and 6.

A resin-made external insulating member 510 is arranged on the outer surface side of the sealing plate 120. A first negative electrode current collector 710 and a resin insulating member 730 (negative electrode current collector holder) are arranged on the inner surface side of the sealing plate 120. Next, the negative electrode terminal 500 is inserted into a through hole of the external insulating member 510, a negative electrode terminal mounting hole of the sealing plate 120, a through hole of the first negative electrode current collector 710, and a through hole of the insulating member 730. Then, the caulking portion 500A located at the tip of the negative electrode terminal 500 is caulked and connected onto the first negative electrode current collector 710. As a result, the negative electrode terminal 500, the external insulating member 510, the sealing plate 120, the first negative electrode current collector 710, and the insulating member 730 are fixed. The portions of the negative electrode terminal 500 and the first negative electrode current collector 710 that are caulked and connected are preferably welded and connected by laser welding or the like.

Further, the second negative electrode current collector 720 is arranged on the insulating member 730 so that a part of the second negative electrode current collector 720 overlaps with the first negative electrode current collector 710. In the first opening 720A provided in the second negative electrode current collector 720, the second negative electrode current collector 720 is welded and connected to the first negative electrode current collector 710 by laser welding or the like.

When attaching the negative electrode current collector 700 to the sealing plate 120, first, the first negative electrode current collector 710 is connected to the insulating member 730 on the sealing plate 120. Subsequently, the second negative electrode current collector 720 connected to the electrode body 200 is attached to the first negative electrode current collector 710. At this time, the second negative electrode current collector 720 is arranged on the insulating member 730 so that a part of the second negative electrode current collector 720 overlaps with the first negative electrode current collector 710. Subsequently, the periphery of the first opening 720A provided in the second negative electrode current collector 720 is welded and connected to the first negative electrode current collector 710 by laser welding or the like.

As shown in FIG. 5, the second positive electrode current collector 620 and the positive electrode tab 210A are joined by welding. Further, as shown in FIG. 6, the second negative electrode current collector 720 and the negative electrode tab 210B are joined by welding. As a result, the electrode body 200 is connected to the sealing plate 120, and the electrode body 200, the positive electrode terminal 400, and the negative electrode terminal 500 are electrically connected.

FIG. 7 is a top view showing the electrode body 200 in the manufacturing process. FIG. 8 is a side view of the electrode body 200 in the manufacturing process shown in FIG. 7.

As shown in FIGS. 7 and 8, the electrode body 200 includes a first electrode body element 201 (first laminated group) and a second electrode body element 202 (second laminated group). As shown in FIG. 7, the positive electrode tab 210A and the negative electrode tab 210B are separated from each other with a distance L3 larger than the width L1 of the positive electrode tab 210A and the width L2 of the negative electrode tab 210B. By doing so, it is possible to suppress a short circuit between the positive electrode tab 210A and the negative electrode tab 210B.

FIG. 9 shows a state in which the positive electrode tab 210A and the negative electrode tab 210B of the electrode body 200 shown in FIGS. 7 and 8 are bent. As shown in FIG. 9, the first electrode body element 201 and the second electrode body element 202 are overlapped by bending the positive electrode tab 210A and the negative electrode tab 210B. That is, in the square secondary battery 1 according to the present embodiment, the first electrode body element 201 and the second electrode body element 202 are overlapped with the positive electrode tab 210A and the negative electrode tab 210B bent.

FIG. 10 is a diagram showing a connection portion between the electrode body 200 and the second positive electrode current collector 620 and the second negative electrode current collector 720. As shown in FIG. 10, the positive electrode tab 210A and the second positive electrode current collector 620 are joined, and the negative electrode tab 210B and the second negative electrode current collector 720 are joined. The positive electrode tab 210A and the second positive electrode current collector 620 are welded to each other at the joint portion A located at the central portion of the positive electrode tab 210A in the longitudinal direction, and the negative electrode tab is formed at the joint portion B located at the central portion of the negative electrode tab 210B in the longitudinal direction. The 210B and the second negative electrode current collector 720 are welded to each other.

FIG. 11 is a top view showing the electrode body 200 according to the modified example. In the modification shown in FIG. 11, the positive electrode tab 210A has a widening portion 220A at a position including the joint portion A with the second positive electrode current collector 620, and the negative electrode tab 210B has a widening portion 220A with the second negative electrode current collector 720. It has a widening portion 220B at a position including the joint portion B. By forming the widening portions 220A and 220B at the positions including the joint portions A and B in this way, the area of the joint portions A and B can be expanded. As a result, the bonding strength between the positive electrode tab 210A and the negative electrode tab 210B and the second positive electrode current collector 620 and the second negative electrode current collector 720 is improved.

FIG. 12 is a diagram showing a process of manufacturing the positive electrode plate 211β, and FIG. 13 is a diagram showing a process of manufacturing the negative electrode plate 212β. 14 is a diagram showing a positive electrode plate 211β manufactured through the process shown in FIG. 12, and FIG. 15 is a diagram showing a negative electrode plate 212β manufactured through the process shown in FIG. 13.

As shown in FIG. 12, the positive electrode active material mixture layer 211A, the uncoated portion 211B, and the positive electrode protective layer 211C are formed on both sides of the positive electrode core body 211α made of a long aluminum foil. The positive electrode active material mixture layer 211A contains a positive electrode active material (for example, lithium nickel cobalt manganese composite oxide, etc.), a binder (polyvinylidene fluoride (PVdF), etc.), and a conductive material (for example, carbon material, etc.). The positive electrode protective layer 211C contains alumina particles, a binder, and a conductive material.

As shown in FIG. 13, the negative electrode active material layer 212A and the uncoated portion 212B are formed on both sides of the negative electrode core body 212α made of a long copper foil.

From the positive electrode core body 211α and the negative electrode core body 212α shown in FIGS. 12 and 13, the positive electrode plate 211β shown in FIG. 14 and the negative electrode plate 212β shown in FIG. 15 are cut out, respectively. The positive electrode plate 211β and the negative electrode plate 212β are alternately laminated via the separator 230.

16 and 17 illustrate the shape of the separator 230. As shown in FIG. 16, the separator 230 may be formed in a rectangular shape, or as shown in FIG. 17, the separator 230 includes two main body portions 230A and a connection portion 230B connecting the two main body portions 230A. May be used. As the separator 230, for example, one made of polyolefin may be used.

The separator 230 preferably has an adhesive layer for adhering to the positive electrode plate 211β and the negative electrode plate 212β. Further, the separator 230 may be adhered to any of the positive electrode plate 211β and the negative electrode plate 212β before the step of laminating the positive electrode plate 211β and the negative electrode plate 212β. Further, the long separator 230 may be folded in a zigzag manner for use.

Although the embodiments of the present technology have been described above, it should be considered that the embodiments disclosed this time are exemplary in all respects and are not restrictive. The scope of the present invention is indicated by the scope of claims and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Square secondary battery, 100 battery case, 110 square exterior body, 120 sealing plate, 121 electrolyte injection hole, 122 sealing member, 123 gas discharge valve, 200 electrode body, 201 1st electrode body element, 202 2nd Electrode body element, 210 main body, 210A positive electrode tab, 210B negative electrode tab, 211A positive electrode active material mixture layer, 211B uncoated part, 211C positive electrode protective layer, 211α positive electrode core, 211β positive electrode plate, 212A negative electrode active material layer, 212B uncoated part, 212α negative electrode core, 212β negative electrode plate, 220A, 220B widening part, 230 separator, 230A main body, 230B connection part, 300 electrode body holder, 400 positive electrode terminal, 400A caulking part, 410 external insulation member , 500 Negative electrode terminal, 500A caulking part, 510 external side insulating member, 600 positive electrode current collector, 610 first positive electrode current collector, 620 second positive electrode current collector, 620A first opening, 620B second opening, 630 insulating member , 630A tubular part, 630B hole part, 700 negative electrode current collector, 710 first negative electrode current collector, 720 second negative electrode current collector, 720A first opening, 730 insulating member, 800 cover member.

Claims (12)

An electrode body including a first laminated group and a second laminated group is provided.
The electrode body includes a positive electrode plate, a negative electrode plate, the positive electrode plate, and a separator laminated with the negative electrode plate.
The positive electrode plate includes a first positive electrode main body portion included in the first laminated group, a second positive electrode main body portion included in the second laminated group, a first positive electrode main body portion, and a second positive electrode main body portion. Including positive tab to connect
The negative electrode plate includes a first negative electrode main body portion included in the first laminated group, a second negative electrode main body portion included in the second laminated group, a first negative electrode main body portion, and a second negative electrode main body portion. Including the negative electrode tab to connect
A battery in which the first laminated group and the second laminated group are stacked with the positive electrode tab and the negative electrode tab bent. Further equipped with a positive electrode current collector and a negative electrode current collector,
The positive electrode tab and the positive electrode current collector are joined to each other.
The battery according to claim 1, wherein the negative electrode tab and the negative electrode current collector are joined. The positive electrode tab and the positive electrode current collector are joined at the central portion in the longitudinal direction of the positive electrode tab.
The battery according to claim 2, wherein the negative electrode tab and the negative electrode current collector are joined at a central portion in the longitudinal direction of the negative electrode tab. The positive electrode tab has a first widening portion at a junction with the positive electrode current collector.
The battery according to claim 2 or 3, wherein the negative electrode tab has a second widening portion at a joint with the negative electrode current collector. Any one of claims 1 to 4, wherein the positive electrode tab and the negative electrode tab are separated from each other with a distance (L3) larger than the width (L1) of the positive electrode tab and the width (L2) of the negative electrode tab. Batteries described in the section. Further equipped with a battery case for accommodating the electrode body,
The positive electrode tab or the negative electrode tab has a through hole and has a through hole.
The battery according to any one of claims 1 to 5, wherein the battery case has an electrolytic solution injection hole at a position facing the through hole. A step of manufacturing a positive electrode plate including a first positive electrode main body portion, a second positive electrode main body portion, and a positive electrode tab connecting the first positive electrode main body portion and the second positive electrode main body portion.
A step of manufacturing a negative electrode plate including a first negative electrode main body portion, a second negative electrode main body portion, and a negative electrode tab connecting the first negative electrode main body portion and the second negative electrode main body portion.
A step of alternately laminating the positive electrode plate and the negative electrode plate via a separator, and
By bending the positive electrode tab and the negative electrode tab, the first laminated group including the first positive electrode main body and the first negative electrode main body, and the second laminated group including the second positive electrode main body and the second negative electrode main body are included. A method of manufacturing a battery, which includes a process of stacking groups. The step of joining the positive electrode tab and the positive electrode current collector,
The method for manufacturing a battery according to claim 7, further comprising a step of joining the negative electrode tab and the negative electrode current collector. The positive electrode tab and the positive electrode current collector are joined at the central portion in the longitudinal direction of the positive electrode tab.
The method for manufacturing a battery according to claim 8, wherein the negative electrode tab and the negative electrode current collector are joined at a central portion in the longitudinal direction of the negative electrode tab. The positive electrode tab and the positive electrode current collector are joined to each other at the first widening portion provided on the positive electrode tab.
The method for manufacturing a battery according to claim 8 or 9, wherein the negative electrode tab and the negative electrode current collector are joined in a second widening portion provided on the negative electrode tab. In the step of laminating the positive electrode plate and the negative electrode plate, the positive electrode tab and the negative electrode tab are separated from each other with a distance (L3) larger than the width (L1) of the positive electrode tab and the width (L2) of the negative electrode tab. The method for manufacturing a battery according to any one of claims 7 to 10. Claims 7 to 11 further include a step of injecting an electrolytic solution into a battery case for accommodating the first laminated group and the second laminated group through a through hole provided in the positive electrode tab or the negative electrode tab. The method for manufacturing a battery according to any one of the following items.

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