JP7236033B2 - sealed battery - Google Patents

Description

The present invention relates to sealed batteries.

Secondary batteries such as lithium-ion secondary batteries and nickel-hydrogen batteries are becoming more and more important as power sources for vehicles, personal computers, mobile terminals, and the like. Such a secondary battery is constructed, for example, as a sealed battery in which an electrode assembly is sealed within a case. This sealed battery has a structure for electrically connecting an electrode body in the case and an external device (another battery, a motor, etc.). For example, a sealed battery has an internal terminal connected to an electrode body inside the case and an external terminal connected to an external device outside the case, and the internal terminal and the external terminal are joined outside the case. ing.

An example of a sealed battery having such a connection structure is disclosed in Patent Document 1. The sealed battery described in Patent Document 1 includes a metal first terminal (corresponding to an external terminal) and a metal second terminal (corresponding to an internal terminal). The first terminal has an insertion hole, a slope formed at the edge of the insertion hole, the outer diameter of which gradually increases toward the outside, and a recess opening in the slope. On the other hand, the second terminal has a shaft portion that is inserted through the insertion hole of the first terminal. In this sealed battery, the tip of the shaft portion of the second terminal is crimped, and a portion of the shaft portion of the second terminal is recessed into the recess of the first terminal. Thereby, the bonding strength between the first terminal and the second terminal can be improved.

JP 2018-78027 A

By the way, in recent years, the demand for safety and durability of sealed batteries has been increasing, and it is required to ensure higher bonding strength between internal terminals and external terminals. SUMMARY OF THE INVENTION The present invention has been made in view of such demands, and an object of the present invention is to provide a technique for improving the bonding strength between internal terminals and external terminals.

In order to achieve the above objects, the present invention provides a sealed battery having the following configuration.

The sealed battery disclosed herein includes a case containing an electrode body, an internal terminal connected to the electrode body inside the case, and a plate-shaped external terminal joined to the internal terminal outside the case. there is The internal terminals of this sealed battery include: a current collecting portion connected to the electrode body inside the case; and a crimped portion that is provided on the portion and deformed under pressure so as to extend along the outer surface of the external terminal. Further, the external terminal has an internal terminal insertion hole into which the shaft portion of the internal terminal is inserted, and at least one notch formed on the outer surface of the peripheral edge of the internal terminal insertion hole. In the sealed battery disclosed herein, a part of the crimped portion of the internal terminal is inserted into the cutout portion of the external terminal, and the crimped portion positioned above the cutout portion is An extending portion is formed that extends outward in the axial radial direction from the portion of .

In the sealed battery disclosed herein, the end portion of the shaft portion outside the case is pressurized and deformed so that the extension portion is formed above the notch portion of the external terminal. As a result, the crimped portion of the internal terminal can be properly inserted into the cutout portion of the external terminal, so that the bonding strength between the internal terminal and the external terminal can be improved more than before.

1 is a cross-sectional view schematically showing a connection structure between internal terminals and external terminals in a sealed battery according to an embodiment of the present invention; FIG. FIG. 2 is a plan view schematically showing the vicinity of the shaft portion of the internal terminal in FIG. 1; FIG. 4 is a perspective view schematically showing the vicinity of the shaft portion of the internal terminal used in one embodiment of the present invention; 4 is a perspective view schematically showing the vicinity of internal terminal insertion holes of external terminals used in one embodiment of the present invention. FIG. FIG. 2 is a cross-sectional view schematically showing a state of the sealed battery shown in FIG. 1 before a caulking process; FIG. 6 is a plan view schematically showing the vicinity of the shaft portion of the internal terminal in FIG. 5; FIG. 10 is a plan view schematically showing the vicinity of the shaft portion of the internal terminal before the crimping process of the sealed battery according to another embodiment of the present invention; FIG. 10 is a plan view schematically showing the vicinity of the shaft portion of the internal terminal before the crimping process of the sealed battery according to another embodiment of the present invention;

A sealed battery according to an embodiment of the present invention will be described below with reference to the drawings. In the drawings below, members and portions having the same function are denoted by the same reference numerals. Note that the dimensional relationships (length, width, thickness, etc.) in each drawing do not reflect the actual dimensional relationships. In addition, matters other than the matters specifically mentioned in this specification and necessary for the implementation of the present invention (for example, general techniques related to construction of sealed batteries such as the structure and manufacturing method of electrode bodies and electrolytes, etc. ) can be grasped as a design matter of a person skilled in the art based on the prior art in the field. In this embodiment, a lithium ion secondary battery is described as an example of a sealed battery, but the sealed battery disclosed herein is not limited to a lithium ion secondary battery, and may be, for example, a nickel metal hydride battery. There may be.

1. 1. Configuration of Sealed Battery FIG. 1 is a cross-sectional view schematically showing a connection structure between an internal terminal and an external terminal in a sealed battery according to the present embodiment, and FIG. It is a top view which shows the vicinity typically. FIG. 3 is a perspective view schematically showing the vicinity of the shaft portion of the internal terminal used in this embodiment. FIG. 4 is a perspective view schematically showing the vicinity of internal terminal insertion holes of external terminals used in the present embodiment. In each figure, the symbol X indicates the "width direction (of the sealed battery)", the symbol Y indicates the "thickness direction (of the sealed battery)", and the symbol Z indicates the "height direction (of the sealed battery)." ” is shown. These directions are determined for the convenience of explanation, and are not intended to limit the directions in which the sealed battery disclosed herein is installed.

As shown in FIG. 1 , a sealed battery 100 according to this embodiment includes a case 10 , internal terminals 20 and external terminals 30 . Each member will be described below.

(1) Case The case 10 includes a rectangular case body 12 with an open top, and a plate-like lid 14 that closes the opening on the top of the case body 12 . It is preferable that the case 10 is mainly made of an inexpensive metal material having a predetermined strength, such as an aluminum alloy. Further, the cover 14 of the case 10 is formed with an opening 14a into which the internal terminal 20 is inserted.

Although not shown, the case 10 accommodates an electrode assembly. For example, the electrode assembly includes a sheet-like positive electrode having a positive electrode mixture layer applied to the surface of the positive electrode current collector foil, a sheet-like negative electrode having a negative electrode mixture layer applied to the surface of the negative electrode current collector foil, and a positive electrode. and an insulating separator interposed between the negative electrode and the negative electrode. Further, like the electrode body, although not shown, the case 10 also contains an electrolyte such as a non-aqueous electrolyte. Regarding the materials of the electrode body and the electrolyte, the same materials as those of conventional general lithium-ion secondary batteries can be used without particular limitation, and detailed description is omitted because they do not characterize the technology disclosed herein. .

(2) Internal Terminal The internal terminal 20 is a conductive member connected to an electrode body inside the case 10 . The internal terminal 20 has a collector portion 22 , a shaft portion 24 and a crimped portion 26 .

The current collecting portion 22 is a portion connected to the electrode body inside the case 10 . Specifically, the current collector 22 is a plate-like member extending downward in the height direction Z (inward of the case 10). A lower end of the current collecting portion 22 is joined to an electrode body (typically, a positive electrode current collecting foil or a negative electrode current collecting foil). In addition, it is preferable that the current collector 22 and the electrode body are joined by conventionally known welding means such as ultrasonic welding, laser welding, and resistance welding.

A shaft portion 24 of the internal terminal 20 penetrates the case 10 and the external terminal 30 and is exposed to the outside of the case 10 . In the sealed battery 100 according to the present embodiment, the shaft portion 24 of the internal terminal 20 passes through the cover 14 of the case 10, the insulating holder 40, and the external terminal 30, and is exposed to the outside of the case 10. parts are placed.

The crimped portion 26 is provided at the end portion of the shaft portion 24 outside the case 10 (that is, the upper end portion of the shaft portion 24 in the height direction Z). The crimped portion 26 presses and deforms the upper end portion 24a (see FIG. 3) of the columnar shaft portion 24 having a circular concave portion 24c in plan view so as to extend along the outer surface 30a of the external terminal 30. formed by In the sealed battery 100 according to this embodiment, the crimped portion 26 of the internal terminal 20 is crimped (bonded) to the external terminal 30 . From the viewpoint of improving the bonding strength between the internal terminal 20 and the external terminal 30 , a welding process such as laser welding may be performed so as to straddle the crimped portion 26 and the external terminal 30 . Further, although the detailed structure will be described later, as shown in FIG. Four portions 26a are formed. Furthermore, as shown in FIGS. 1 and 3 , in the internal terminal 20 of the present embodiment, a plate-shaped pedestal portion 28 is formed between the collector portion 22 and the shaft portion 24 .

For the internal terminal 20, a desired metal material can be appropriately selected in consideration of the material, conductivity, bonding strength, material cost, etc. of the object to be connected (current collector foil of the electrode body). Typically, it is preferable that the internal terminal 20 is made of the same kind of metal material as the collector foil of the electrode body. Thereby, the internal terminal 20 and the electrode body can be connected with low resistance and high strength. For example, since copper or a copper alloy is used for the negative electrode current collector foil of a general lithium ion secondary battery, the internal terminal 20 connected to the negative electrode current collector foil is made of copper or a copper alloy. is preferred. On the other hand, since aluminum or an aluminum alloy is used for the positive electrode current collector foil of a general lithium ion secondary battery, the internal terminal 20 connected to the positive electrode current collector foil is made of aluminum or an aluminum alloy. is preferred.

(3) External Terminal The external terminal 30 is a plate-like conductive member joined to the internal terminal 20 outside the case 10 . As described above, the external terminal 30 is joined to the crimped portion 26 of the internal terminal 20 . Further, the external terminal 30 is provided with an internal terminal insertion hole 32 into which the shaft portion 24 of the internal terminal 20 is inserted. Specifically, the external terminal 30 extends along the outer side surface 14b of the lid 14 (case 10), and an internal terminal insertion hole 32 is formed at one end in the width direction X. As shown in FIG. Further, in this embodiment, a bolt insertion hole 36 is formed at the other end of the external terminal 30 in the width direction X. As shown in FIG.

As shown in FIG. 4, a notch portion 34 is formed in the peripheral edge portion of the internal terminal insertion hole 32 on the outer surface 30a of the external terminal 30. As shown in FIG. The notch portion 34 is a groove-shaped concave portion extending along the radial direction of the internal terminal insertion hole 32 . In this embodiment, the external terminal 30 is formed with four notches 34 . The four notches 34 are formed at intervals of 90° in the circumferential direction of the peripheral portion of the internal terminal insertion hole 32 . In other words, in this embodiment, two pairs of notch portions 34 are formed facing each other with the internal terminal insertion hole 32 interposed therebetween. As will be described later in detail, in the sealed battery 100 according to the present embodiment, as shown in FIG. 1 and 2, the extension 26a of the crimped portion 26 is located above the notch 34 of the external terminal 30. As shown in FIGS.

(4) Other Members As shown in FIG. 1, the sealed battery 100 according to this embodiment includes an insulating holder 40 and a bolt 50 in addition to the above-described members. Note that these members (the insulating holder 40 and the bolt 50) do not limit the technology disclosed here.

The insulating holder 40 is an insulating member for preventing conduction between the above-described conductive terminals (the internal terminals 20 and the external terminals 30) and the case 10 (the lid 14). The insulating holder 40 is made of insulating resin such as polyamide resin, polyacetal resin, or polyimide resin. The insulating holder 40 has an outer holder 42 and an inner holder 44 . The external holder 42 is arranged between the outer surface 14 b of the lid 14 and the external terminal 30 . The external holder 42 has a bolt housing portion 42a for housing the lower end of a bolt 50, which will be described later, and a first insertion hole 42b for inserting the shaft portion 24 of the internal terminal 20 therethrough. On the other hand, the inner holder 44 is arranged between the inner side surface 14 c of the lid 14 and the pedestal portion 28 of the inner terminal 20 . The internal holder 44 has a second insertion hole 44a through which the shaft portion 24 of the internal terminal 20 is inserted, and a cylindrical protrusion 44b formed around the second insertion hole 44a. The protrusion 44b of the inner holder 44 is inserted into the opening 14a of the lid 14 and crimped to the bottom surface of the outer holder 42. As shown in FIG.

The bolt 50 is a columnar metal member standing along the height direction Z, and has a screw groove (not shown) formed on its outer peripheral surface. A lower end portion of the bolt 50 is accommodated in the bolt accommodating portion 42a of the external holder 42. As shown in FIG. Also, the bolt 50 is inserted through the bolt insertion hole 36 of the external terminal 30 . In the sealed battery 100 having such a bolt 50, a connection member (bus bar) with an external device is arranged on the peripheral edge portion 36a of the bolt insertion hole 36 of the external terminal 30, and a nut is tightened on the bolt 50, The bus bar and the external terminal 30 can be easily and firmly connected.

(5) Joint Portion Between Internal Terminal and External Terminal As described above, in the sealed battery 100 according to the present embodiment, the upper end portion 24a of the shaft portion 24 of the internal terminal 20 is deformed under pressure to form the crimped portion 26. Thus, the internal terminal 20 and the external terminal 30 are joined. At this time, by partially inserting the crimped portion 26 of the internal terminal 20 into the notch portion 34 of the external terminal 30, the bonding strength between the internal terminal 20 and the external terminal 30 can be improved. Here, in the present embodiment, the shaft portion 24 is pressurized and deformed (crimped) so that the extended portion 26 a is formed in the crimped portion 26 located above the notch portion 34 . As a result, the crimped portion 26 of the internal terminal 20 can be appropriately inserted into the notch portion 34 of the external terminal 30, so that the bonding strength between the internal terminal 20 and the external terminal 30 can be improved more than before. can. A procedure for manufacturing a sealed battery 100 having such an extension portion 26a will be described below.

2. Manufacturing Method The sealed battery 100 according to the present embodiment is manufactured by performing (1) an assembly step and (2) a crimping step in this order. Each step will be described below. 5 is a cross-sectional view schematically showing the state of the sealed battery shown in FIG. 1 before the caulking process. 6 is a plan view schematically showing the vicinity of the shaft portion of the internal terminal in FIG. 5. FIG.

(1) Assembly process As shown in FIG. 5, in this process, the upper end portion 24a of the shaft portion 24 of the internal terminal 20 is positioned outside the case (above the height direction Z) relative to the external terminal 30. , the internal terminal 20 and the external terminal 30 are assembled to the case 10 (cover body 14). Specifically, in this step, first, the external holder 42 is placed on the outer surface 14b of the lid 14 so that the opening 14a of the lid 14 and the first insertion hole 42b of the external holder 42 overlap. . With the lower end of the bolt 50 housed in the bolt housing portion 42a of the external holder 42, the bolt 50 is inserted into the bolt insertion hole 36 of the external terminal 30, and the external terminal 30 is inserted into the outer surface 42c of the external holder 42. Place on top. Next, the inner holder 44 is arranged below the inner surface 14c of the lid 14 so that the projection 44b is inserted into the opening 14a of the lid 14 . Then, the external terminal 30, the external holder 42, the lid 14, and the internal holder 44 are sandwiched, and the area around the internal terminal insertion hole 32 of the external terminal 30 is pressurized. As a result, the upper surface of the projection 44b of the inner holder 44 and the lower surface of the outer holder 42 are crimped to temporarily fix the above members. Next, the shaft portion 24 of the internal terminal 20 is inserted into the internal terminal insertion hole 32 of the external terminal 30 from the inside of the lid 14 (lower side in the height direction Z). As a result, the pedestal portion 28 of the internal terminal 20 is fitted into the internal holder 44 of the insulating holder 40 , and the upper end portion 24 a of the shaft portion 24 is arranged above the external terminal 30 .

Here, in this embodiment, an internal terminal 20 having a shaft portion 24 as shown in FIG. 3 is used. Specifically, the shaft portion 24 of the internal terminal 20 shown in FIG. 3 has a columnar upper end portion 24a extending in the axial direction (height direction Z). Four projecting portions 25 projecting outward are formed. The four projections 25 are formed at intervals of 90° in the circumferential direction, similarly to the notch 34 of the external terminal 30 described above. Then, in this step, as shown in FIG. 6, each of the four projections 25 of the internal terminal 20 is aligned with each of the four cutouts 34 of the external terminal 30 so as to be in close proximity to each other. The arrangement position of the portion 24 is adjusted. In other words, in the present embodiment, the internal terminal 20 is attached to the case 10 so that the protrusion 25 of the internal terminal 20 and the cutout 34 of the external terminal 30 are close to each other in the circumferential direction.

As shown in FIG. 3, a concave portion 24c is formed on the upper surface of the shaft portion 24 of the internal terminal 20 and has a circular shape in a plan view and is recessed along the axial direction (height direction Z). A lower end portion 24b of the shaft portion 24 is shaped like a disc. As shown in FIG. 5 , the disk-shaped lower end portion 24 b is fitted into the second insertion hole 44 a of the internal holder 44 when the internal terminal 20 is assembled to the case 10 .

(3) Crimping Process In this process, the upper end portion 24a of the shaft portion 24 exposed to the outside of the case 10 is pressed and deformed along the outer surface 30a of the external terminal 30 for crimping. As a result, the crimped portion 26 as shown in FIG. 1 is formed, and the internal terminal 20 and the external terminal 30 are joined. Specifically, in the caulking process in this step, a pressing jig is inserted into the recess 24c of the shaft portion 24, and while rotating the pressing jig, the upper end of the shaft portion 24 is bent so as to expand the diameter of the recess 24c. The portion 24a is press-deformed outward in the axial radial direction. As a result, the crimped portion 26 extending along the outer side surface 30a of the external terminal 30 as shown in FIG. 1 is formed, and the crimped portion 26 and the external terminal 30 are crimped.

At this time, in the present embodiment, as shown in FIG. 6, each projecting portion 25 of the internal terminal 20 is close to the notch portion 34 of the external terminal 30 . Therefore, when the crimping process is performed, the upper end portion 24a of the shaft portion 24 is deformed into a plate-like shape after the tip of each protrusion 25 enters the notch portion 34 . As a result, a part of the crimped portion 26 can be inserted into the notch portion 34 more easily than in the conventional art, so that the bonding strength between the internal terminal 20 and the external terminal 30 can be improved. Then, when the internal terminal 20 and the external terminal 30 are crimped according to the above-described procedure, the projection 25 of the internal terminal 20 is crushed so that the crimped portion 26 is pushed outward in the axial radial direction relative to the other portions of the crimped portion 26 . An extending portion 26a (see FIGS. 1 and 2) is formed. As described above, in the present embodiment, each protrusion 25 is adjacent to the notch 34 of the external terminal 30 , so that the extension 26 a after crimping is formed above the notch 34 . be.

As described above, in the present embodiment, the internal terminal 20 having the projection 25 formed on the shaft 24 is used, and the crimping process is performed while the projection 25 is brought close to the cutout 34 of the external terminal 30. conduct. As a result, the crimped portion 26 can be properly inserted into the notch portion 34, so that the bonding strength between the internal terminal 20 and the external terminal 30 can be improved more than before. When the internal terminal 20 and the external terminal 30 are joined by such a procedure, the crimped portion 26 positioned above the notch portion 34 is radially outward of the other portion of the crimped portion 26 . An extension portion 26a extending toward is formed.

It should be noted that the effect of improving the bonding strength according to the present embodiment is particularly favorably exhibited when the internal terminals and the external terminals are made of different metal materials. In a normal sealed battery, the internal terminals and the external terminals are made of the same kind of metal material from the viewpoint of ensuring sufficient bonding strength. However, in recent years, from the viewpoint of material cost reduction, it has been studied to configure the external terminals with a metal material that is cheaper than the internal terminals. For example, when the internal terminals are made of copper, the use of a metal material (such as aluminum) that is less expensive than copper for the external terminals is under study. However, when such different kinds of metal members are joined (dissimilar metal joining), the bonding strength may decrease due to insufficient viscosity and toughness of the crimped portion between the internal terminal and the external terminal. Also, if the internal terminal and the external terminal have different hardness, the one using a soft metal material will be crushed during the crimping process, and the crimped part of the internal terminal may enter the notch of the external terminal. can become difficult.
In contrast, in the sealed battery 100 according to the present embodiment, after the tip of the protrusion 25 enters the notch 34, the upper end 24a of the shaft 24 is deformed into the plate-like crimped portion 26. A part of the crimped portion 26 can be appropriately inserted into the notch portion 34 without being affected by the material of the internal terminal 20 and the external terminal 30 . Therefore, according to the present embodiment, even when dissimilar metal bonding is performed between the internal terminal 20 and the external terminal 30, sufficiently strong bonding strength can be ensured.

3. Other Embodiments Although one embodiment of the sealed battery disclosed herein has been described above, the present invention is not limited to the above-described embodiment, and various structures can be changed.

For example, in the above-described embodiment, since the shaft portion 24 having four protrusions 25 as shown in FIG. 6 is press-deformed, the crimped portion 26 after crimping has four extension portions 26a (see FIG. 2). is formed. However, the number of extending portions (that is, projections before crimping) in the crimped portion is not limited to the above-described embodiment, as long as the number corresponds to the cutout portions of the external terminals.

For example, as shown in FIG. 7, when three notches 34 are formed in the periphery of the internal terminal insertion hole 32 on the outer surface of the external terminal 30, three projections adjacent to each of the notches 34 are formed. It is preferable that the portion 25 is formed at the upper end portion 24a of the shaft portion 24 . In such a case, the sealed battery after crimping is formed with three extending portions corresponding to the above-described three protrusions 25 . Further, as shown in FIG. 8, when five notches 34 are formed in the external terminal 30, the five protrusions 25 adjacent to the respective notches 34 are located at the upper end portion 24a of the shaft portion 24. is preferably formed.

From the viewpoint of properly inserting the protrusion 25 into the notch 34 during caulking, the angle θ of the tip of the protrusion 25 is preferably an acute angle (90° or less), and preferably 85° or less. It is more preferably 80° or less, and particularly preferably 75° or less. The outer shape of the upper end portion 24a of the shaft portion 24 is not particularly limited as long as the angle θ of the tip of the projection portion 25 satisfies a desired angle. For example, when four protrusions 25 are formed as shown in FIG. 3, the outer shape of the upper end portion 24a of the shaft portion 24 can be a quadrangular prism. On the other hand, when five or more protrusions are formed, if the outer shape of the upper end of the shaft is polygonal, the tip of the protrusion has an obtuse angle, making it difficult for the protrusion to enter the notch. In such a case, as shown in FIG. 8, it is possible to form a cylindrical upper end portion 24a and project a protrusion 25 having an acute angle from the outer peripheral surface of the cylindrical upper end portion 24a in the axial radial direction. preferable. As a result, even when five or more protrusions are formed, the angle θ of the tips of the protrusions can be easily made acute. Moreover, from the viewpoint of properly inserting the protrusion 25 into the notch 34, the lower limit of the angle θ of the tip of the protrusion 25 is not particularly limited, and may be 10° or more. However, considering the strength of the protrusion 25, the angle θ of the tip of the protrusion 25 is preferably 30° or more, more preferably 35° or more, still more preferably 40° or more, and particularly preferably 45° or more.

In addition, as described above, the number of notches and projections (that is, extensions after crimping) is not particularly limited, and as long as at least one of each is formed, the internal terminal and the external terminal It is possible to appropriately improve the bonding strength with. However, from the viewpoint of obtaining stronger bonding strength, it is preferable to form two or more of each of the notches and the protrusions. By forming two or more notches and protrusions in this way, it is possible to restrict the rotation of the shaft of the internal terminal after crimping, thereby suppressing damage to the joint due to the rotation of the shaft. can. From the viewpoint of more reliably restricting the rotation of the shaft, the number of notches and protrusions is preferably three or more, more preferably four or more, and even more preferably five or more. Moreover, from the viewpoint of improving the bonding strength, the upper limit of the number of notches and protrusions is not particularly limited, and may be 10 or less. However, considering manufacturing efficiency, the upper limit of the number of notches and projections is preferably 9 or less, more preferably 8 or less, and even more preferably 7 or less.

Although specific examples of the present invention have been described in detail above, these are merely examples and do not limit the scope of the claims. The technology described in the claims includes various modifications and changes of the specific examples illustrated above.

10 Case 12 Case body 14 Lid 14a Opening 14b Lid outer surface 14c Lid inner surface 20 Internal terminal 22 Current collector 24 Shaft 24a Shaft upper end 24b Shaft lower end 24c Recess 25 Projection 26 Crimped portion 26a Extension portion 28 Pedestal portion 30 External terminal 30a External terminal outer surface 32 Internal terminal insertion hole 34 Notch portion 36 Bolt insertion hole 36a Peripheral portion 40 of bolt insertion hole Insulation holder 42 External holder 42a Bolt storage portion 42b First insertion hole 42c Outer surface 44 of outer holder Inner holder 44a Second insertion hole 44b Projection 50 Bolt 100 Sealed battery X Width direction Y Depth direction Z Height direction θ Angle of tip of protrusion

Claims (1)

A sealed battery comprising a case containing an electrode body, an internal terminal connected to the electrode body inside the case, and a plate-shaped external terminal joined to the internal terminal outside the case,
The internal terminal is
a current collector connected to the electrode body inside the case;
a shaft penetrating through the case and the external terminal and exposed to the outside of the case;
a crimped portion provided at the end portion of the shaft portion outside the case and deformed under pressure so as to extend along the outer surface of the external terminal;
The external terminal is
an internal terminal insertion hole into which the shaft portion of the internal terminal is inserted;
at least one notch formed in a peripheral edge of the internal terminal insertion hole on the outer surface,
A part of the crimped portion of the internal terminal enters the cutout portion of the external terminal, and the crimped portion located above the cutout portion is more axial than the other portions of the crimped portion. A sealed battery, wherein an extension extending radially outward is formed.

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