JP6769412B2 - Sealed battery - Google Patents

Description

The present disclosure relates to a closed-type battery, and more particularly to a configuration of a current collecting terminal provided in the closed-type battery.

Japanese Unexamined Patent Publication No. 2007-299536 (Patent Document 1) discloses a sealed square non-aqueous electrolyte secondary battery. This sealed battery has an electrode body having an edge portion in which uncoated portions of a sheet-shaped electrode plate not coated with the electrode active material are laminated, and a current collecting terminal welded to the edge portion of the electrode body. And. A plurality of slits are formed in the current collector terminal, and the current collector (electrode body) and the current collector terminal are welded together with the current collector at the edge of the electrode body inserted into these slits. (See Patent Document 1).

JP-A-2007-299536

When the current collector and the current collector terminal are welded (generally laser welding) with the current collector of the electrode body inserted in the slit, the current collector should be firmly sandwiched in the slit. Welding is performed between the current collector and the current collector terminal in a state where the current collector terminal is deformed by applying an external force (pinching force) to the current collector terminal.

However, when the current collecting terminal is deformed, if a gap remains in the slit due to twisting of the leg forming the slit, laser light may escape from the gap during welding, or it may occur during welding. The metal pieces may scatter toward the electrode body and affect the electrode body.

The present disclosure has been made to solve such a problem, and an object thereof is to seal the current collecting terminal to the electrode body in a good manner and to suppress the influence on the electrode body at the time of welding. It is to provide a mold battery.

The sealed battery of the present disclosure includes an electrode body and a current collecting terminal. The electrode body is configured to include a plurality of laminated electrode plates, and a current collector is formed on a side surface of the plurality of electrode plates along the stacking direction. The current collector terminal is welded to the current collector. The current collecting terminal includes a pedestal portion, a plurality of legs portions, and a member. The plurality of legs extend from the pedestal portion along the side surface of the electrode body at intervals from each other. The current collector is sandwiched between the plurality of legs and welded to the plurality of legs. Then, the member is provided on one leg of the plurality of legs and extends from one leg toward the other leg adjacent to the outside thereof, and the one leg of the other leg. It is configured to regulate the movement of other legs in the direction of the electrode body while allowing the movement in the direction of.

In the sealed battery of the present disclosure, since the above-mentioned member is provided at the current collector terminal, twisting of the leg portion is suppressed when the current collector of the electrode body is sandwiched between the plurality of legs. As a result, the current collector can be firmly sandwiched between the plurality of legs without any gaps, so that good welding can be performed, and laser light can escape from the gaps during welding, which occurs during welding. It is possible to prevent the metal pieces from scattering toward the electrode body side. As described above, according to the sealed battery of the present disclosure, the current collecting terminal can be satisfactorily welded to the electrode body, and the influence on the electrode body at the time of welding can be suppressed.

It is sectional drawing of the closed type battery according to embodiment of this disclosure. It is a top view when the positive electrode current collector terminal attached to the electrode body is seen in the X direction. It is a top view of the positive electrode current collecting terminal when the positive electrode current collecting terminal is viewed from the −X direction (from the electrode body side). It is sectional drawing along IV-IV in FIG. It is sectional drawing which shows typically the state when the slit between the legs is closed by applying an external force (pinching force) to a leg. It is sectional drawing which shows typically the state when the slit between the legs is closed by applying an external force (pinching force) to a leg. It is sectional drawing which shows typically the state when the slit between the legs is closed by applying an external force (pinching force) to a leg. It is a flowchart which shows the manufacturing process of a closed type battery. It is a top view of the positive electrode sheet. It is a top view of the negative electrode sheet. It is a perspective view of the electrode body. It is a perspective view of the electrode body. It is a figure which showed typically the mode that the positive electrode current collector is molded in the current collector pre-molding step S2. It is a figure which showed typically the mode that the positive electrode current collector is molded in the current collector pre-molding step S2. It is a top view before the positive electrode current collector terminal is shaped. It is a figure which showed the state which the plate member was attached to the positive electrode current collector terminal. It is a figure which showed the state which the positive electrode external terminal and the negative electrode external terminal, and the positive electrode current collecting terminal and the negative electrode current collecting terminal were assembled to the lid of the accommodating case. It is a figure which showed the state which the lid of the accommodating case, the positive electrode current collecting terminal and the negative electrode current collecting terminal were assembled to an electrode body. It is a figure which showed how the positive electrode current collecting terminal is assembled to an electrode body. It is a perspective view which shows the state that the positive electrode current collector is welded to the leg part of the positive electrode current collector terminal. It is sectional drawing which shows the state that the positive electrode current collector is welded to the leg part of the positive electrode current collector terminal. It is sectional drawing which shows the state that the positive electrode current collector is welded to the leg part of the positive electrode current collector terminal. It is sectional drawing which shows the state that the positive electrode current collector is welded to the leg part of the positive electrode current collector terminal. It is a top view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the comparative example is seen from the electrode body side. It is a top view when the positive electrode current collector terminal in the comparative example is seen in the Y direction. It is sectional drawing which shows typically the leg part of the positive electrode current collector terminal at the time of the current collector terminal pressurization process in the comparative example. It is sectional drawing which shows typically the leg part of the positive electrode current collector terminal at the time of the current collector terminal pressurization process in the comparative example. It is sectional drawing which showed the state that the positive electrode current collector is welded to the leg part of the positive electrode current collector terminal in the comparative example. It is a figure which showed the evaluation result of the welding of the current collector terminal and the current collector in the closed type battery which follows the embodiment of this disclosure, and the closed type battery of a comparative example. FIG. 5 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the first modification of the embodiment is viewed from the −X direction (from the electrode body side). It is sectional drawing which follows XXXI-XXXI in FIG. FIG. 5 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the second modification of the embodiment is viewed from the −X direction (from the electrode body side). It is sectional drawing which follows XXXIII-XXXIII in FIG. FIG. 5 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the modified example 3 of the embodiment is viewed from the −X direction (from the electrode body side). FIG. 3 is a plan view of the positive electrode current collecting terminal attached to the electrode body in the third modification when viewed in the X direction.

Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings. The same or corresponding parts in the drawings are designated by the same reference numerals, and the description thereof will not be repeated.

<Overall configuration of sealed battery>
FIG. 1 is a cross-sectional view of a sealed battery 1 according to an embodiment of the present disclosure. With reference to FIG. 1, the sealed battery 1 includes a housing case 2, an electrode body 3, an electrolytic solution 6, a positive electrode external terminal 9, a negative electrode external terminal 10, a positive electrode current collecting terminal 11, and a negative electrode current collector. It is provided with a terminal 12. A positive electrode current collector 7 is formed on the side surface 4 of the electrode body 3, and a negative electrode current collector 8 is formed on the side surface 5 of the electrode body 3. The electrode body 3, the positive electrode current collecting terminal 11, and the negative electrode current collecting terminal 12 are housed in a storage case 2, and the electrolytic solution 6 is injected into the storage case 2.

The storage case 2 includes a case body 20 and a lid 21. The case body 20 is formed with an opening that opens upward. The lid 21 is arranged so as to close the opening of the case body 20, and the lid 21 is welded to the case body 20. A positive electrode external terminal 9 and a negative electrode external terminal 10 are arranged on the upper surface of the lid 21.

The electrode body 3 includes a plurality of positive electrode sheets, a plurality of separators, and a plurality of negative electrode sheets (each of which is not shown). The electrode body 3 is formed by alternately laminating positive electrode sheets and negative electrode sheets with a separator interposed therebetween.

The positive electrode current collector 7 is formed by laminating the ends of the positive electrode sheets, and constitutes the positive electrode of the electrode body 3. The negative electrode current collector 8 is formed by laminating the ends of the negative electrode sheets, and constitutes the negative electrode of the electrode body 3.

The positive electrode current collecting terminal 11 includes a pedestal portion 22, a leg portion 23, and a plate member 24. The pedestal portion 22 is arranged on the upper surface of the electrode body 3 (in the −Y direction of the electrode body 3), and is electrically connected to the positive electrode external terminal 9 through a hole formed in the lid 21. The leg portion 23 is connected to the pedestal portion 22 and is provided so as to extend in the Y direction along the side surface 4 of the electrode body 3. The legs 23 are welded to the positive electrode current collector 7. Although not shown in FIG. 1, the leg portion 23 is composed of a plurality of leg portions extending along the side surface 4 at intervals (slits) from each other.

The plate member 24 is a surface of the leg portion 23 facing the electrode body 3, and is provided above the connecting portion between the leg portion 23 and the positive electrode current collector 7 (on the pedestal portion 22 side). When the positive electrode current collector 7 is sandwiched between the slits of the leg portion 23 when the leg portion 23 and the positive electrode current collector 7 are connected (welded), the plate member 24 is formed by a plurality of leg portions constituting the leg portion 23. It is a member for suppressing arrangement disorder. The arrangement and configuration of the plate member 24 will be described in detail later.

The negative electrode current collecting terminal 12 includes a pedestal portion 25, a leg portion 26, and a plate member 27. The pedestal portion 25 is also arranged on the upper surface of the electrode body 3 (in the −Y direction of the electrode body 3), and is electrically connected to the negative electrode external terminal 10 through a hole formed in the lid 21. The leg portion 26 is connected to the pedestal portion 25 and is provided so as to extend in the Y direction along the side surface 5 of the electrode body 3. The leg portion 26 is welded to the negative electrode current collector 8. Although not shown in FIG. 1, the leg portion 26 is also composed of a plurality of leg portions extending along the side surface 5 at intervals (slits) from each other.

The plate member 27 is a surface of the leg portion 26 facing the electrode body 3, and is provided above the connecting portion between the leg portion 26 and the negative electrode current collector 8 (on the pedestal portion 25 side). When the negative electrode current collector 8 is sandwiched between the slits of the leg portion 26 when the leg portion 26 and the negative electrode current collector 8 are connected (welded), the plate member 27 is formed by a plurality of leg portions constituting the leg portion 26. It is a member for suppressing arrangement disorder.

<Current collector terminal configuration>
FIG. 2 is a plan view of the positive electrode current collecting terminal 11 attached to the electrode body 3 when viewed in the X direction. Further, FIG. 3 is a plan view of the positive electrode current collecting terminal 11 when the positive electrode current collecting terminal 11 is viewed from the −X direction (from the electrode body 3 side), and FIG. 4 shows IV-IV in FIG. It is a cross-sectional view along. The configuration of the negative electrode current collecting terminal 12 is the same as that of the positive electrode current collecting terminal 11, and the positive electrode current collecting terminal 11 will be typically described below.

With reference to FIGS. 2 to 4, the leg 23 of the positive electrode current collecting terminal 11 is composed of four legs 23A to 23D. The number of legs is not limited to four, and may be more or less than this. A gap (slit) is provided between the legs 23A to 23D. The positive electrode current collector 7 is gathered together with the slit and inserted into the slit. Then, while applying external force (narrow force) from both sides of the legs 23A to 23D so as to narrow the width of the slit, the positive electrode current collector 7 inserted in the slit is irradiated with the laser beam, so that the leg is formed at the welded portion 28. The portions 23A to 23D are welded to the positive electrode current collector 7 (FIG. 2).

The plate member 24 is composed of plate members 24A and 24B. The plate members 24A and 24B are provided on the back surface side (electrode body 3 side) of the leg portion 23, above the positive electrode current collector 7 of the electrode body 3 (side close to the pedestal portion 22). The plate members 24A and 24B are joined to the legs 23B and 23C by the joints 29, respectively. The plate member 24A is formed so as to extend from the leg portion 23B toward the leg portion 23A adjacent to the outside thereof and to hang on the leg portion 23A. The plate member 24B is formed so as to extend from the leg portion 23C toward the leg portion 23D adjacent to the outside thereof and to extend over the leg portion 23D.

By providing such a plate member 24, the positive electrode current collector 7 is sandwiched in the slit between the legs 23A to 23D when welding the leg portions 23A to 23D and the positive electrode current collector 7, and the leg portions 23A to 23D are provided. When an external force (narrow force) is applied from both sides, the disorder of the arrangement of the legs 23A to 23D is suppressed. As a result, the positive electrode current collector 7 is firmly sandwiched between the legs 23A to 23D without any gaps, so that good welding is performed at the welded portion 28, and laser light escapes from the gaps during welding or welding. It is possible to prevent the metal pieces generated in the process from scattering toward the electrode body 3.

5 to 7 are cross-sectional views schematically showing a state when an external force (pinching force) is applied to the legs 23A to 23D to close the slit between the legs 23A to 23D. FIG. 5 shows the arrangement of the legs 23A to 23D before the slit is closed. FIG. 6 shows the arrangement of the legs 23A to 23D when the slits between the legs 23A and 23B and the slits between the legs 23C and 23D are closed by applying a pinching force to the legs 23A to 23D. FIG. 7 shows the arrangement of the legs 23A to 23D when the slit between the legs 23B and 23C is also closed by further applying a pinching force. In reality, since the positive electrode current collector 7 is sandwiched between the legs 23A to 23D, the slits are not completely closed as shown in FIGS. 6 and 7.

As shown in FIG. 6, when the legs 23A and 23D are moved (deformed) in the Z direction by applying an external force (pinching force) in the Z direction to the legs 23A and 23D so as to close the slit, the legs 23A Since the roots of the legs 23A and 23D are connected to the pedestal portion 22 (not shown), a twisting moment as shown by an arrow is generated in the leg portions 23A and 23D. However, in the sealed battery 1 according to this embodiment, the plate members 24A and 24B serve as stoppers to suppress the twisting of the legs 23A and 23D. As a result, as shown in FIG. 7, twisting of the legs 23B and 23C, which receive loads from the legs 23A and 23D, respectively, is also suppressed.

In this way, the plate member 24A (24B) restricts the movement of the leg 23A (23D) in the direction of the electrode body 3 while allowing the leg 23A (23D) to move in the direction of the leg 23B (23C). ) Is provided, so that when the positive electrode current collectors 7 are gathered together and sandwiched in the slit between the legs 23A to 23D, the twisting of the legs 23A to 23D is suppressed and the arrangement of the legs 23A to 23D is disturbed. Is suppressed.

<Manufacturing method of sealed battery>
FIG. 8 is a flowchart showing a manufacturing process of the sealed battery 1. With reference to FIG. 8, the manufacturing process of the sealed battery 1 includes an electrode body molding step S1, a current collector preforming step S2, a current collecting terminal molding step S3, a plate plate mounting step S4, and a lid molding step. S5, lid / electrode body assembly step S6, current collecting terminal pressurizing step S7, current collecting terminal welding step S8, accommodating step S9, lid welding step S10, injection step S11, and sealing step S12. And include.

In the electrode body forming step S1, a plurality of positive electrode sheets and negative electrode sheets are produced, and the positive electrode body 3 is formed by alternately laminating the positive electrode sheets and the negative electrode sheets with the insulator separator interposed therebetween.

FIG. 9 is a plan view of the positive electrode sheet. With reference to FIG. 9, in the positive electrode sheet 30, the rectangular active material mixture layer 31 coated on the front and back surfaces of the aluminum alloy foil sheet and the uncoated portion provided on one side of the aluminum alloy foil sheet have predetermined dimensions. Includes the uncoated foil portion 32 cut into. The uncoated foil portion 32 is a portion of the positive electrode sheet 30 where the active material mixture layer 31 is not formed, and is a portion where the aluminum alloy foil sheet is exposed from the active material mixture layer 31. The uncoated foil portion 32 becomes a positive electrode current collector 7 when the positive electrode sheet 30, the negative electrode sheet 33 and the separator are laminated to form the electrode body 3.

FIG. 10 is a plan view of the negative electrode sheet. With reference to FIG. 10, in the negative electrode sheet 33, the rectangular active material mixture layer 34 coated on the front and back surfaces of the copper foil sheet and the uncoated portion provided on one side of the copper foil sheet are cut to predetermined dimensions. Includes the unpainted foil portion 35 and the like. The uncoated foil portion 35 is a portion of the negative electrode sheet 33 where the active material mixture layer 34 is not formed, and is a portion where the copper foil sheet is exposed from the active material mixture layer 34. The uncoated foil portion 35 becomes the negative electrode current collector 8 when the positive electrode sheet 30, the negative electrode sheet 33 and the separator are laminated to form the electrode body 3.

FIG. 11 is a perspective view of the electrode body 3. With reference to FIG. 11, in the electrode body 3, the positive electrode sheet 30 (FIG. 9) and the negative electrode sheet 33 (FIG. 10) are alternately and sequentially laminated with a separator (not shown) containing a porous insulating layer interposed therebetween. Formed by At this time, as shown in the figure, the plurality of positive electrode sheets 30 are laminated so that the uncoated foil portions 32 of each positive electrode sheet 30 are aligned, and the laminated uncoated foil portions 32 form the positive electrode current collector 7. Will be done.

Although not shown, the plurality of negative electrode sheets 33 are laminated and laminated so that the uncoated foil portions 35 of each negative electrode sheet 33 are aligned on the side opposite to the uncoated foil portion 32 of the positive electrode sheet 30. The negative electrode current collector 8 is formed by the uncoated foil portion 35.

With reference to FIG. 8 again, in the current collector preforming step S2, the positive electrode current collector 7 is formed so that the positive electrode current collector 7 can be inserted into the slit between the legs 23A to 23D of the positive electrode current collector terminal 11. Will be done. In this embodiment, as shown in FIG. 12, the positive electrode current collector 7 is formed into three aggregates according to the number of slits (three) of the positive electrode current collector terminal 11. Although not shown, the negative electrode current collector 8 is also formed on the negative electrode side so that the negative electrode current collector 8 can be inserted into the slit between the legs of the negative electrode current collector terminal 12.

13 and 14 are diagrams schematically showing how the positive electrode current collector 7 is molded in the current collector preforming step S2. With reference to FIGS. 13 and 14, the positive electrode current collector 7 is formed by using the foil collecting jigs 50 and 51. The foil collecting jigs 50 and 51 have a convex shape at the tip, and after moving the foil collecting jigs 50 and 51 toward the positive electrode current collector 7, the foil collecting jigs 50 and 51 collect the positive electrodes. By sandwiching the electric body 7, the positive electrode current collector 7 is formed (habited).

With reference to FIG. 8 again, in the current collecting terminal forming step S3, the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12 are manufactured.

FIG. 15 is a plan view of the positive electrode current collecting terminal 11 before being shaped. With reference to FIG. 15, the positive electrode current collecting terminal 11 is made of aluminum, and the original plate of the positive electrode current collecting terminal 11 is formed by punching an aluminum plate with a predetermined mold. The original plate is provided with a pedestal portion 22 and legs 23A to 23D extending from the pedestal portion 22, and the positive electrode current collecting terminal 11 is formed by bending the original plate at 90 degrees along the dotted line in the figure. Although not shown, the negative electrode current collecting terminal 12 is made of copper, and the original plate of the negative electrode current collecting terminal 12 is formed by punching a copper plate with a predetermined mold, and the original plate is bent in the same manner as the positive electrode current collecting terminal 11. The negative electrode current collecting terminal 12 is formed.

With reference to FIG. 8 again, in the plate plate attaching step S4, the plate member 24 is attached to the positive electrode current collecting terminal 11 and the plate member 27 is attached to the negative electrode current collecting terminal 12.

FIG. 16 is a diagram showing a state in which the plate member 24 is attached to the positive electrode current collecting terminal 11. With reference to FIG. 16, the pedestal portion 22 is bent 90 degrees with respect to the plurality of leg portions 23A to 23D (in this figure, it is bent toward the front side of the paper surface). Then, the plate members 24 (24A, 24B) are attached to the surfaces of the legs 23A to 23D on the side where the pedestal portion 22 is bent.

The plate members 24 (24A, 24B) are located above the positive electrode current collector 7 (pedestal portion 22 side) of the electrode body 3 when the positive electrode current collector terminal 11 is assembled to the electrode body 3. It is attached to the positive electrode current collecting terminal 11. Specifically, the plate member 24A is attached to the leg portion 23B by the joint portion 29 so as to extend from the leg portion 23B toward the leg portion 23A adjacent to the outside thereof and to cover the leg portion 23A. The plate member 24B is attached to the leg portion 23C by the joint portion 29 so as to extend from the leg portion 23C toward the leg portion 23D adjacent to the outside thereof and to cover the leg portion 23D. The plate member 27 is also attached to the negative electrode current collector terminal 12 in the same manner.

With reference to FIG. 8 again, in the lid forming step S5, the positive electrode external terminal 9, the negative electrode external terminal 10, the positive electrode current collecting terminal 11, and the negative electrode current collecting terminal 12 are assembled to the lid 21 of the housing case 2.

FIG. 17 is a diagram showing a state in which the positive electrode external terminal 9 and the negative electrode external terminal 10, and the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12 are assembled to the lid 21 of the housing case 2. With reference to FIG. 17, the positive electrode external terminal 9 is assembled to one end of the upper surface of the lid 21, and the negative electrode external terminal 10 is assembled to the other end of the upper surface of the lid 21.

Then, below the positive electrode external terminal 9, the positive electrode current collecting terminal 11 is assembled on the lower surface of the lid 21, and the positive electrode external terminal 9 and the pedestal portion 22 of the positive electrode current collecting terminal 11 are electrically connected through a hole formed in the lid 21. Is connected. Similarly, below the negative electrode external terminal 10, the negative electrode current collecting terminal 12 is assembled on the lower surface of the lid 21, and the negative electrode external terminal 10 and the pedestal portion 25 of the negative electrode current collecting terminal 12 are connected through a hole formed in the lid 21. It is electrically connected.

With reference to FIG. 8 again, in the lid / electrode body assembling step S6, the lid 21, the positive electrode external terminal 9, the negative electrode external terminal 10, the positive electrode current collecting terminal 11, and the negative electrode current collecting as assembled in the lid molding step S5. The terminal 12 is assembled to the electrode body 3.

FIG. 18 is a diagram showing a state in which the lid 21, the positive electrode current collecting terminal 11, and the negative electrode current collecting terminal 12 of the accommodating case 2 are assembled to the electrode body 3. FIG. 19 is a diagram showing how the positive electrode current collecting terminal 11 is assembled to the electrode body 3.

With reference to FIGS. 18 and 19, the lid 21, the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12 are assembled to the electrode body 3 from above the electrode body 3. At this time, the positive electrode current collector terminal 11 is assembled to the electrode body 3 so that the positive electrode current collector 7 is inserted into the slit of the leg 23 of the positive electrode current collector terminal 11. Although not shown, the negative electrode current collector terminal 12 is also assembled to the electrode body 3 on the negative electrode side so that the negative electrode current collector 8 is inserted into the slit of the leg 26 of the negative electrode current collector terminal 12. ..

With reference to FIG. 8 again, in the current collecting terminal pressurizing step S7, the legs 23 of the positive electrode current collecting terminal 11 are pressurized from both side surfaces, and the gap between the legs 23 and the positive electrode current collector 7 is narrowed. Similarly, the legs 26 of the negative electrode current collector terminal 12 are also pressurized from both side surfaces, and the gap between the legs 26 and the negative electrode current collector 8 is narrowed.

In the current collecting terminal welding step S8, the leg portion 23 of the positive electrode current collecting terminal 11 and the positive electrode current collector 7 are welded, and the leg portion 26 of the negative electrode current collecting terminal 12 and the negative electrode current collector 8 are welded.

FIG. 20 is a perspective view showing how the positive electrode current collector 7 is welded to the legs 23 of the positive electrode current collector terminal 11. 21 to 23 are cross-sectional views showing how the positive electrode current collector 7 is welded to the legs 23 of the positive electrode current collector terminal 11.

With reference to FIGS. 20 to 23, the tip of the positive electrode current collector 7 projects from the slit between the legs 23A to 23D. In the current collector terminal pressurizing step S7, the positive electrode current collector 7 is subjected to the leg 23A by irradiating the tip of the positive electrode current collector 7 with the laser beam LB while the legs 23A to 23D are pressurized from both sides. Welded to ~ 23D.

In this embodiment, since the plate members 24 (24A, 24B) are provided on the legs 23A to 23D, the legs are twisted when the legs 23A to 23D are pressurized in the current collecting terminal pressurizing step S7. Is suppressed, and the disorder of the arrangement of the legs 23A to 23D is suppressed. As a result, in the current collecting terminal pressurizing step S7, the positive electrode current collector 7 can be firmly sandwiched between the legs 23A to 23D without any gap, and the legs 23A to 23D are collected by the positive electrode in the welded portion 28. It is well welded to the body 7.

With reference to FIG. 8 again, in the accommodating step S9, the electrode body 3, the lid 21, the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12 assembled to the electrode body 3 are attached to the case body 20 of the accommodating case 2. Be housed. The lid 21 is arranged so as to close the opening of the case body 20.

In the lid welding step S10, the outer peripheral edge of the lid 21 and the opening edge of the case body 20 are welded. In the injection step S11, the electrolytic solution 6 is injected into the storage case 2 from an injection port (not shown) of the lid 21. Then, in the sealing step S12, the injection port is closed by the sealing member. As a result, the sealed battery 1 shown in FIG. 1 is completed.

<Explanation of comparative example>
Hereinafter, a comparative example in which the plate members 24 and 27 are not provided on the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12, respectively, will be briefly described.

FIG. 24 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the comparative example is viewed from the electrode body side. FIG. 25 is a plan view of the positive electrode current collecting terminal in the comparative example when viewed in the Y direction. With reference to FIGS. 24 and 25, the positive electrode current collector terminal in the comparative example is not provided with the plate member 24 according to the embodiment. Then, in the current collecting terminal pressurizing step, when the legs of the positive electrode current collecting terminal are pressurized from both side surfaces, the outer legs 23A and 23D are deformed in the load direction.

26 and 27 are cross-sectional views schematically showing the legs of the positive electrode current collector terminal during the current collector terminal pressurization step in the comparative example. FIG. 26 shows the arrangement of the legs 23A to 23D when the slits between the legs 23A and 23B and the slits between the legs 23C and 23D are closed by applying a pinching force to the legs 23A to 23D. FIG. 27 shows the arrangement of the legs 23A to 23D when the slit between the legs 23B and 23C is also closed by further applying a pinching force. In reality, since the positive electrode current collector is sandwiched between the legs 23A to 23D, the slits are not completely closed as shown in FIGS. 26 and 27.

With reference to FIGS. 26 and 27 as well as FIG. 25, the positive electrode current collecting terminal in the comparative example is not provided with the plate member 24 according to the embodiment of the present disclosure. When an external force (pinching force) in the Z direction is applied to ~ 23D, the legs 23A and 23D are twisted from the base of the slit (FIG. 25), and the legs 23A and 23D are twisted on the slit side (the legs 23B of the legs 23A). The adjacent side and the side of the leg 23D adjacent to the leg 23C) are deformed in the X direction (direction of the electrode body).

When an external force (pinching force) is further applied to the legs 23A to 23D to the extent that the slit between the legs 23B and 23C is also closed (FIG. 27), the base of the slit between the legs 23B and 23C is deformed in the Y direction. As a result, the legs 23B and 23C are deformed in the −X direction (the direction opposite to the legs 23A and 23D).

As described above, in the comparative example, when the legs 23A to 23D are pressurized from both side surfaces in the current collecting terminal pressurizing step, the outer legs 23A and 23D are twisted and the inner legs 23B and 23C are also deformed. Therefore, the arrangement of the legs 23A to 23D is disturbed in the current collecting terminal pressurizing step, and a gap remains between the legs 23A to 23D and the positive electrode current collector 7. If the legs 23A to 23D are welded to the positive electrode current collector in the current collector terminal welding process in this state, the laser beam may escape from the gap or the metal pieces generated by the welding may be scattered toward the electrode body. There is a risk of

FIG. 28 is a cross-sectional view showing how the positive electrode current collector 7 is welded to the legs 23 of the positive electrode current collector terminal in the comparative example. With reference to FIG. 28, the positive electrode current collector 7 is welded to the legs 23A to 23D by irradiating the tip of the positive electrode current collector 7 protruding from the slit between the legs 23A to 23D with the laser beam LB. To.

In the comparative example, since the arrangement of the legs 23A to 23D is disturbed, there is a possibility that a gap is formed between the legs 23A to 23D and the positive electrode current collector 7. Then, the laser beam LB may escape from the gap, or as shown in the figure, metal pieces generated by welding may be scattered toward the electrode body side (current collector side).

On the other hand, in the sealed battery 1 according to this embodiment, as shown in FIGS. 2 to 7, the legs 23A (23D) are allowed to move in the direction of the legs 23B (23C) while being allowed to move. A plate member 24A (24B) for restricting the movement of the leg portion 23A (23D) in the direction of the electrode body 3 is provided. As a result, in the current collector terminal pressurizing step S7, when the positive electrode current collector 7 is sandwiched between the slits between the legs 23A to 23D, the legs 23A to 23D are arranged as shown in FIGS. 5 to 7. The disturbance of the current collector 7 is suppressed, and the positive electrode current collector 7 can be firmly sandwiched between the legs 23A to 23D without any gap. As a result, good welding can be performed, and it is possible to prevent the laser beam LB from coming out from the gap during welding and the metal pieces generated by welding from being scattered toward the electrode body 3.

FIG. 29 is a diagram showing the evaluation results of welding between the current collector terminal and the current collector in the sealed battery 1 according to the embodiment of the present disclosure and the sealed battery of the above comparative example. In the evaluation of welding, the welded part was disassembled, damage to the separator due to laser light leakage was confirmed, and the presence or absence of scattered melt was confirmed. Damage to the separator Regarding damage, it was confirmed with a magnifying glass whether or not a transparent part due to heat was generated on the separator. Regarding the scattering of the melt, the presence or absence of the scattering on the back side of the current collector terminal was confirmed with a magnifying glass. Regarding the evaluation, those with no damage to the separator and no scattering of melt were regarded as good products (evaluation OK).

With reference to FIG. 29, for the sealed battery of the comparative example, at least one of damage to the separator and scattering of melt was confirmed in 5 out of 10 samples. In the current collecting terminal pressurizing step, the arrangement of the legs of the current collecting terminal was disturbed, so that the laser light escaped from the gap and the metal pieces generated by welding were scattered.

On the other hand, all 10 samples of the sealed battery 1 according to the embodiment of the present disclosure were good products. In the sealed battery 1, since the plate members 24 and 27 are provided on the positive electrode current collecting terminal 11 and the negative electrode current collecting terminal 12, respectively, the arrangement disorder of the legs of the current collecting terminal is suppressed in the current collecting terminal pressurizing step. To. As a result, the laser light escape from the gap is suppressed, the damage of the separator and the scattering of the molten material due to welding into the battery are suppressed.

As described above, according to the embodiment of the present disclosure, the positive electrode current collector terminal 11 and the negative electrode current collector terminal 12 can be satisfactorily welded to the electrode body 3 (positive electrode current collector 7 and negative electrode current collector 8). Moreover, the influence on the electrode body 3 at the time of welding can be suppressed.

[Modification 1]
FIG. 30 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the first modification of the embodiment is viewed from the −X direction (from the electrode body 3 side), and FIG. 31 is a plan view of the positive electrode current collecting terminal in FIG. It is sectional drawing along XXXI-XXXI. The configuration of the negative electrode current collecting terminal is also the same as that of the positive electrode current collecting terminal, and the positive electrode current collecting terminal will be typically described below.

With reference to FIGS. 30 and 31, in this modification 1, the positive electrode current collector terminal 11A is the plate member 24 (24A, in the positive electrode current collector terminal 11 in the above embodiment shown in FIGS. 3 and 4). 24B) is replaced with the plate member 40 (40A, 40B).

The plate member 40A is different from the plate member 24A in that a step portion 41A is formed at a portion extending over the leg portion 23A. The step portion 41A is formed so as to have a gap with the leg portion 23A. The plate member 40B is also different from the plate member 24B in that a step portion 41B is formed at a portion extending over the leg portion 23D. The step portion 41B is formed so as to have a gap with the leg portion 23D.

Regarding the gap between the step portion 41A and the leg portion 23A and the gap between the step portion 41B and the leg portion 23D, for example, the leg portion when pressurizing the leg portions 23A to 23D in the current collecting terminal pressurizing step S7. It can be determined based on the twist tolerance of 23A and 23D.

By forming such step portions 41A and 41B, the leg portions 23A (23D) become the plate member 40A (40B) in the initial stage of pressurizing the leg portions 23A to 23D in the current collecting terminal pressurizing step S7. Do not contact with. As a result, friction does not occur between the leg portions 23A (23D) and the plate member 40A (40B), and the load on the leg portions 23A to 23D and the deformation of the leg portions 23A to 23D are reduced.

[Modification 2]
FIG. 32 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the second modification of the embodiment is viewed from the −X direction (from the electrode body 3 side), and FIG. 33 is a plan view of the positive electrode current collecting terminal in FIG. 32. It is sectional drawing along XXXIII-XXXIII. The configuration of the negative electrode current collecting terminal is also the same as that of the positive electrode current collecting terminal, and the positive electrode current collecting terminal will be typically described below.

With reference to FIGS. 32 and 33, in the second modification, the positive electrode current collector terminal 11B is attached to the plate members 24A and 24B in the positive electrode current collector terminal 11 according to the above embodiment shown in FIGS. 3 and 4. Instead, the plate-shaped portions 45A and 45B are included, respectively.

The plate-shaped portions 45A and 45B are integrally formed with the leg portions 23B and 23C at the portions where the plate members 24A and 24B of the positive electrode current collecting terminals 11 shown in FIGS. 3 and 4 are attached.

The plate-shaped portion 45A is formed so as to extend from the leg portion 23B toward the leg portion 23A adjacent to the outside thereof and to extend over the leg portion 23A. The plate-shaped portion 45B is formed so as to extend from the leg portion 23C toward the leg portion 23D adjacent to the outside thereof and to extend over the leg portion 23D.

Although not particularly shown, in the portion of the plate-shaped portion 45A that covers the leg portion 23A, a step portion is provided so as to have a gap with the leg portion 23A, and the leg portion of the plate-shaped portion 45B is provided as in the above modification 1. A step portion may be provided so as to have a gap with the leg portion 23D in the portion relating to the 23D.

[Modification 3]
FIG. 34 is a plan view of the positive electrode current collecting terminal when the positive electrode current collecting terminal in the modified example 3 of the embodiment is viewed from the −X direction (from the electrode body 3 side). FIG. 35 is a plan view of the positive electrode current collecting terminal attached to the electrode body 3 in the modified example 3 when viewed in the X direction.

With reference to FIGS. 34 and 35, in the above embodiment, as shown in FIGS. 2 and 3, the plate members 24A and 24B are above the positive electrode current collector 7 of the electrode body 3 (pedestal portion). Although it was supposed to be provided on the side closer to 22), as shown in the figure, the plate members 24A and 24B are provided below the positive electrode current collector 7 of the electrode body 3 (the side far from the pedestal portion 22). May be good.

The embodiments disclosed this time should be considered as exemplary in all respects and not restrictive. The scope of the present invention is shown by the scope of claims rather than the description of the embodiment described above, and is intended to include all modifications within the meaning and scope equivalent to the scope of claims.

1 Sealed battery, 2 Storage case, 3 Electrode body, 4, 5 End face, 6 Electrode solution, 7 Positive electrode current collector, 8 Negative electrode current collector, 9 Positive electrode external terminal, 10 Negative electrode external terminal, 11, 11A, 11B Positive electrode Current collection terminal, 12 negative electrode current collection terminal, 20 case body, 21 lid, 22,25 pedestal, 23,23A to 23D, 26 legs, 24,24A, 24B, 27,40A, 40B plate member, 28 welds , 29 Joint part, 30 Positive electrode sheet, 31,34 Active material mixture layer, 32,35 Uncoated foil part, 33 Negative electrode sheet, 41A, 41B Step part, 45A, 45B Plate-shaped part, 50,51 Foil collection cure Ingredients.

Claims (1)

An electrode body composed of a plurality of laminated electrode plates and having a current collector formed on a side surface of the plurality of electrode plates along the stacking direction.
A current collector terminal welded to the current collector is provided.
The current collector terminal
With the pedestal
Including a plurality of legs extending along the side surface from the pedestal portion at intervals from each other.
The current collector is sandwiched between the plurality of legs and welded to the plurality of legs.
The current collector terminal further
It is provided on one inner leg of the plurality of legs and extends from the one leg toward the other leg adjacent to the outside of the one leg, and the other leg of the other leg. A sealed battery comprising a member configured to allow movement in the direction of one leg while restricting movement of the other leg in the direction of the electrode body.

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