Secondary batteries

Abstract

To provide a secondary battery that is easily assembled.SOLUTION: A secondary battery comprises: an outer container that has long side walls and a lid body; an electrode body that has an electrode group and collector tabs extending from the electrode group, and is stored in the outer container; output terminals; leads that has junctions facing the lid body and connected with the output terminals, a first extension part extending from the junction along an inner face of one long side wall, and a second extension part extending from the junction along an inner face of the other long side wall; a first insulator that has an inner face engaged with an outer face of the first extension part; and a second insulator that has an inner face engaged with an outer face of the second extension part.SELECTED DRAWING: Figure 9

Description

[Technical Field]

[0001] FIELD An embodiment of the present invention relates to a secondary battery. [Background technology]

[0002] In recent years, high-energy-density secondary batteries, such as lithium-ion secondary batteries, have been widely used as power sources for electronic devices and electric vehicles. Such secondary batteries are constructed by housing an electrode assembly and a nonaqueous electrolyte in a rectangular outer container made of aluminum or an aluminum alloy. It is known that a predetermined gap is provided between the lid of the outer container and the electrode assembly, and an insulator is used as a spacer to maintain the gap. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-204799 A [Patent Document 2] JP 2020-136010 A Summary of the Invention [Problem to be solved by the invention]

[0004] An object of this embodiment is to provide a secondary battery that is easy to assemble. [Means for solving the problem]

[0005] A secondary battery according to one embodiment includes an outer container having a pair of long side walls opposed to each other with a gap therebetween and a lid body fixed to one end of the pair of long side walls; Has current collecting tabsan electrode body accommodated in the outer container; an output terminal provided on the lid; a lead provided between the electrode body and the lid inside the outer container, electrically connecting the output terminal and the current collecting tab, the lead having a joint portion facing the lid and connected to the output terminal, a first extension portion extending from the joint portion along the inner surface of one of the long side walls, and a second extension portion extending from the joint portion along the inner surface of the other long side wall; a first insulator provided between the electrode body and the lid inside the outer container, the first insulator being disposed opposite the inner surface of one of the long side walls and having an inner surface engaged with the outer surface of the first extension portion; and a second insulator provided between the electrode body and the lid inside the outer container, the second insulator being disposed opposite the inner surface of the other long side wall and having an inner surface engaged with the outer surface of the second extension portion. an adhesive member bonded across a pair of side surfaces of the electrode body and outer surfaces of the first insulator and the second insulator facing the long side wall; It is equipped with: [Brief explanation of the drawings]

[0006] [Figure 1] FIG. 1 is a perspective view showing the appearance of a secondary battery according to a first embodiment. [Figure 2] FIG. 2 is an exploded perspective view of the secondary battery shown in FIG. [Figure 3] FIG. 3 is a perspective view showing a lead. [Figure 4] FIG. 4 is a perspective view of the lead shown in FIG. 3 as viewed from the rear surface side. [Figure 5] FIG. 5 is a perspective view showing one of the insulators. [Figure 6] FIG. 6 is a perspective view showing the electrode body, the positive electrode lead, the negative electrode lead, the insulator, and the adhesive member. [Figure 7] FIG. 7 is a cross-sectional view taken along line BB in FIG. 6, seen from the direction of arrow C, and shows the positive electrode lead and the insulator. [Figure 8] FIG. 8 is a cross-sectional view taken along line BB in FIG. 6, seen from the direction of arrow D, and shows the positive electrode lead and the insulator. [Figure 9] FIG. 9 is a cross-sectional view taken along line AA in FIG. [Figure 10]FIG. 10 is a perspective view showing an electrode assembly, a positive electrode lead, a negative electrode lead, and an insulator in a secondary battery according to the second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0007] Hereinafter, embodiments of the present invention will be described with reference to the drawings. The disclosure is merely an example, and appropriate modifications that those skilled in the art can easily make while maintaining the spirit of the invention are naturally included within the scope of the present invention. Furthermore, to clarify the drawings and explanations, the width, thickness, shape, etc. of each part may be shown schematically compared to the actual embodiment, but these are merely examples and are not intended to limit the interpretation of the present invention. Furthermore, in this specification and each drawing, elements similar to those previously described with reference to the previous drawings may be designated by the same reference numerals, and detailed descriptions may be omitted where appropriate.

[0008] (First embodiment) The secondary battery according to the first embodiment will be described in detail below. FIG. 1 is a perspective view showing the appearance of a secondary battery according to a first embodiment. As shown in FIG. 1 , the secondary battery 10 is, for example, a nonaqueous electrolyte secondary battery such as a lithium ion battery, and includes a flat, approximately rectangular parallelepiped outer container 12 and an electrode assembly 30 (described below) housed inside the outer container 12 together with a nonaqueous electrolyte. The outer container 12 is, for example, a resin container made of resin. The outer container 12 has a container body 16 with an open top end and a plate-shaped lid body 14 fixed to the container body 16 and closing the opening of the container body 16, forming an airtight interior. In the first embodiment, as described above, the container body 16 and the lid body 14 are made of an electrically insulating resin.

[0009] The cover 14 is provided with a pair of output terminals 20 and an injection port 29 . Here, the longitudinal direction of the lid 14 and the container body 16 is defined as X, the width direction of the lid 14 and the container body 16 perpendicular to the longitudinal direction X is defined as Y, and the height direction of the container body 16 is defined as Z. The outer container 12 is not limited to resin, and may be a metal container made of metal such as aluminum alloy, iron, or stainless steel.

[0010] FIG. 2 is an exploded perspective view of the secondary battery shown in FIG. 2, the container body 16 of the outer container 12 has a rectangular long side wall 16a, a rectangular long side wall 16b that faces the long side wall 16a in parallel with and spaced apart from the long side wall 16a, a pair of opposing short side walls 16c, and a bottom wall 16d. A rectangular upper opening 17 is defined by the upper edges of the pair of long side walls 16a, 16b and the upper edges of the pair of short side walls 16c. The lid 14 is formed in the shape of a rectangular plate having a size approximately equal to that of the upper opening 17. The lid 14 is fixed to the container body 16 in a state in which the upper opening 17 is closed. A pair of circular through-holes 26 are formed in the lid 14. Each through-hole 26 is a through-hole formed by penetrating the lid 14 in the height direction (thickness direction) Z. The pair of through-holes 26 are located at both ends of the lid 14 in the longitudinal direction X and are spaced apart from each other in the longitudinal direction X. An inlet 29 is located between the pair of through-holes 26. After the nonaqueous electrolyte is injected into the exterior container 12 through the inlet 29, the inlet 29 is sealed with, for example, a disk-shaped sealing lid 25. The output terminal 20 is formed in a columnar shape extending along the height direction Z and integrally includes a first male threaded portion 20a formed at one end, a second male threaded portion 20b formed at the other end, and an annular flange portion 20c located between the first male threaded portion 20a and the second male threaded portion 20b. The flange portion 20c is formed, for example, in a hexagonal shape and forms a nut. The output terminal 20 is attached to the lid 14 with the first male threaded portion 20a inserted into the through-hole 26 of the lid 14. As shown in Fig. 2, the electrode assembly 30 housed in the outer container 12 is formed by, for example, stacking a plurality of sheet-like positive electrode plates and a plurality of sheet-like negative electrode plates alternately with a separator sandwiched between them. The positive electrode plate has a plate-like positive electrode current collector, a positive electrode active material layer formed on at least one surface of the positive electrode current collector, and a positive electrode current collector tab 32a extending from one end of the positive electrode current collector in the height direction Z. The negative electrode plate has a plate-like negative electrode current collector, a negative electrode active material layer formed on at least one surface of the negative electrode current collector, and a negative electrode current collector tab 32b extending from one end of the negative electrode current collector in the height direction Z. The separator is electrically insulating and electrically insulates the positive electrode plate from the negative electrode plate. The current collectors and current collecting tabs of the positive and negative electrode plates are formed, for example, from a metal foil having a thickness of about 5 to 50 μm. The material of the metal foil can vary depending on the type of active material used in the positive and negative electrodes, but examples of the material that can be used include aluminum, an aluminum alloy, copper, and a copper alloy.

[0011] The positive electrode current collecting tabs 32a extend outward from one end of the electrode assembly (electrode group) 30 and are stacked in the width direction Y. The extending ends of the positive electrode current collecting tabs 32a may be collectively held by a backup lead 34 bent into a U-shape. The positive electrode current collecting tabs 32a are located on one end side of the electrode assembly 30 in the longitudinal direction X. The negative electrode current collecting tabs 32b extend outward from one end of the electrode body 30 and are stacked in the width direction Y. The extending portions of the negative electrode current collecting tabs 32b are collectively clamped by a backup lead 34 bent into a U-shape, and the negative electrode current collecting tabs 32b are located on the other end side of the electrode body 30 in the longitudinal direction X.

[0012] In this way, the positive electrode current collecting tab 32a and the negative electrode current collecting tab 32b extend in the same direction from one end of the electrode body 30, and are positioned at a distance from each other in the longitudinal direction X of the electrode body 30. Furthermore, the positive electrode current collecting tab 32a and the negative electrode current collecting tab 32b have spring properties and exert an upward biasing force in the height direction Z. The electrode assembly 30 configured as described above is housed inside the container body 16 with one end face of the electrode assembly 30, the positive electrode current collecting tab 32a, and the negative electrode current collecting tab 32b facing the lid 14 in the height direction Z. A predetermined gap is provided between the one end face of the electrode assembly 30 and the lid 14.

[0013] As shown in FIG. 2, the secondary battery 10 includes a pair of insulators 50, an adhesive member 38, a positive electrode lead 40A, and a negative electrode lead 40B, which are provided in the space between the electrode body 30 and the lid body 14 inside the outer container 12. The insulator 50 is formed, for example, from an electrically insulating resin. The insulator 50 is formed in a frame shape so as to surround the space between the lid 14 and the electrode assembly 30, and is disposed in contact with the inner surface of the container body 16. The insulator 50 electrically insulates the positive electrode lead 40A, the negative electrode lead 40B, the positive electrode current collector tab 32a, and the negative electrode current collector tab 32b from the container body 16, and also functions as a spacer that maintains the distance between the lid 14 and the electrode assembly 30. In one example, the insulator 50 is divided into a pair of insulators 50, which are combined to form a frame. The detailed shape of the insulator 50 will be described later in the description of FIG.

[0014] The adhesive member 38 is, for example, a strip-shaped adhesive tape. The adhesive member 38 maintains the integrated state of each insulator 50 and the electrode body 30. The position where the adhesive member 38 is attached will be described later in the description of FIG. 6.

[0015] The positive electrode lead 40A is located between the insulators 50 in the width direction Y, and electrically connects the output terminal 20 and the positive electrode current collecting tab 32a. The negative electrode lead 40B is located between the insulators 50 in the width direction Y, and electrically connects the output terminal 20 and the negative electrode current collecting tab 32b. In the first embodiment, the positive electrode lead 40A and the negative electrode lead 40B have the same configuration and the same shape. The structure of the positive electrode lead 40A of the leads of the secondary battery 10 according to the first embodiment will be described in detail below.

[0016] FIG. 3 is a perspective view showing the positive electrode lead, and FIG. 4 is a perspective view of the positive electrode lead as seen from a different direction. 3 and 4, the positive electrode lead 40A is formed by bending a conductive metal plate. In one example, the positive electrode lead 40A integrally includes a rectangular joint 41, a rectangular first extension portion 45 extending from one side edge of the joint 41 substantially perpendicular to the joint 41, and a pair of rectangular second extension portions 43 extending from both ends of the other side edge of the joint 41 substantially perpendicular to the joint 41. The joint portion 41 is formed in the shape of a rectangular plate having a pair of side edges extending in the longitudinal direction X, and has an upper surface 41a facing the lid body 14 and a lower surface 41b located on the opposite side of the upper surface 41a. The joint portion 41 has a pair of first engaging protrusions 48 that protrude in the planar direction beyond the first extending portion 45 from both ends of one side edge, and a second engaging protrusion 49 that protrudes in the planar direction beyond the second extending portion 43 from the center of the other side edge. Furthermore, the joint 41 has a cylindrical protrusion 47 protruding from approximately the center of the lower surface 41b, and a female thread 42 formed to penetrate the joint 41 and the protrusion 47 in the height direction Z. The female thread 42 has a length of 2 mm or more in the direction along the axis 42a, and is provided for screwing in the first male thread 20a of the output terminal 20.

[0017] The first extending portion 45 extends in a plate shape along the height direction Z and has an outer surface 45a that faces parallel to the long side wall 16b of the container body 16. First engaged portions 46 are recesses formed by recessing a pair of side edges of the first extending portion 45 extending in the height direction Z. Each of the second extending portions 43 has an outer surface 43a that faces and is parallel to the long side wall 16a of the container body 16. The second extending portions 43 have second engaged portions 44 that are through-holes formed to penetrate the second extending portions 43 in the width direction Y. However, in one example, the second engaged portions 44 are elongated holes that extend in the longitudinal direction X.

[0018] The shape of the insulator 50 according to the first embodiment will be described below. 5 is a perspective view showing one of the insulators 50. In one example, each insulator 50 has the same shape. As shown in FIG. 5 , the insulator 50 is formed in the shape of a long, narrow plate extending in the longitudinal direction X, and has an inner surface 52 that engages with the positive electrode lead 40A and the negative electrode lead 40B, an outer surface 54 that abuts against the inner surface of the container body 16, an upper surface 53 that faces the lid body 14 between the inner surface 52 and the outer surface 54, and connecting portions 56 that are formed by bending both end portions in the longitudinal direction X in the width direction Y. The inner surface 52 of the insulator 50 is formed with two ribs 58 protruding from the inner surface at the center in the longitudinal direction X, and multiple, for example, four, engagement protrusions 60 protruding between the ribs 58 and the connecting portion 56. The rib 58 has an end surface 59 that faces the lid 14 and is located on the same plane as the top surface 53. The rib 58 increases the rigidity of the insulator 50 and prevents the adhesive member 38 from sagging. The multiple engaging protrusions 60 are formed at positions and with dimensions that allow them to engage with the first engaged portion 46 or the second engaged portion 44 of the positive electrode lead 40A or the negative electrode lead 40B. The connecting portion 56 has a protrusion 56a on one end surface and a recess 56b on the other end surface. The protrusion 56a and the recess 56b are formed in positions and with dimensions that allow them to engage with each other. The pair of insulators 50 are connected by the protrusion 56a of one insulator engaging with the recess 56b of the other insulator 50 and the recess 56b of one insulator engaging with the protrusion 56a of the other insulator 50. Furthermore, by connecting the pair of insulators 50 to each other, the rib 58 of one insulator 50 abuts against the rib 58 of the other insulator 50.

[0019] The positions where the adhesive members 38 according to the first embodiment are attached will be described below. 6 is a perspective view showing the electrode assembly 30, the positive electrode lead 40A, the negative electrode lead 40B, the insulator 50, and the adhesive member 38. In addition, parts of the positive electrode lead 40A, the negative electrode lead 40B, and the pair of insulators 50 are indicated by dashed lines. As shown in FIG. 6, a pair of insulators 50 are connected above the electrode body 30, and the inner surfaces 52 of the pair of insulators are engaged with and connected to the first extension portion 45 and the second extension portion 43 of the positive electrode lead 40A and the negative electrode lead 40B.

[0020] The adhesive member 38 holds the electrode body 30, the positive electrode lead 40A, the negative electrode lead 40B, and the insulators 50 in an integrated state. More specifically, the biasing force of the positive electrode current collecting tab 32a and the negative electrode current collecting tab 32b prevents the positive electrode lead 40A, the negative electrode lead 40B, and the insulators 50 from separating from the electrode body 30. The adhesive member 38 is attached to the pair of side surfaces 31 of the electrode body 30 in the width direction Y, the outer surfaces 54 of each insulator 50, and the upper surfaces 53 of each insulator 50. In one example, the adhesive member 38 is attached so as to overlap the end surfaces 59 of the ribs 58. This prevents the adhesive member 38 from sagging in the height direction Z. However, the position where the adhesive member 38 is attached is not limited to the above position, and it is sufficient if the insulator 50 can be fixed so as not to separate from the electrode body 30. For example, it is possible to attach the adhesive member 38 along the longitudinal direction X so as to overlap the outer surface 54 of each insulator 50 and a pair of side surfaces 31 of the electrode body 30.

[0021] The engagement between the positive electrode lead 40A and each insulator 50 according to the first embodiment will be described below. 7 is a cross-sectional view taken along line BB in FIG. 6, seen from the direction of arrow C, and shows the positive electrode lead 40A and the insulator 50. In FIG. 7, the positive electrode lead 40A is connected by engagement between the first engaged portion 46 of the positive electrode lead 40A and the engaging protrusion 60 of the insulator 50. A gap is provided between the first engaged portion 46 and the engaging protrusion 60 in the longitudinal direction X. The first engaged portion 46 and the engaging protrusion 60 abut against each other in the height direction Z.

[0022] 8 is a cross-sectional view taken along line BB in FIG. 6, seen from the direction of arrow D, and shows the positive electrode lead 40A and the insulator 50. In FIG. 8, the positive electrode lead 40A is connected by engagement between the second engaged portion 44 of the positive electrode lead 40A and the engaging protrusion 60 of the insulator 50. A gap is provided between the second engaged portion 44 and the engaging protrusion 60 in the longitudinal direction X. The second engaged portion 44 and the engaging protrusion 60 abut against each other in the height direction Z. That is, the positive electrode lead 40A is configured to be movable in the longitudinal direction X with respect to the insulator 50, but movement in the height direction Z is restricted. The reason for restricting movement of the positive electrode lead 40A in the height direction Z is to prevent the positive electrode lead 40A from shifting relative to each insulator 50 due to the biasing force of the positive electrode current collecting tab 32a and the negative electrode current collecting tab 32b.

[0023] The internal structure of the assembled secondary battery 10 will now be described. FIG. 9 is a cross-sectional view taken along line AA in FIG. 9, the outer container 12 has a container body 16 that is open at the top end, and a lid 14 that closes the opening of the container body 16. The electrode body 30, a positive electrode lead 40A, and a pair of insulators 50 are housed inside the outer container 12. An output terminal 20 is attached from the outside of the outer container 12 (above the lid 14). The electrode body 30 is located between the pair of long side walls 16a, 16b of the container body 16 and has a positive electrode current collecting tab 32a extending toward the lid body 14. The tip of the positive electrode current collecting tab 32a is held by the backup lead 34 and connected to the first extending portion 45 of the positive electrode lead 40A. The pair of insulators 50 are aligned in the width direction Y and positioned between the electrode body 30 and the lid body 14. The outer surface of each insulator 50 abuts against the inner surface of the container body 16, and the inner surface of each insulator 50 engages with the outer surface of the positive electrode lead 40A.

[0024] The positive electrode lead 40A is located between the electrode body 30 and the cover body 14, and is connected to the insulators 50 by the first engaged portion 46 and the second engaged portion 44 engaging with the engaging protrusions 60 of the insulators 50. (See Figures 3, 4, and 5 for the first engaged portion 46, the second engaged portion 44, and the engaging protrusions 60.) The positive electrode lead 40A has a joint 41 in contact with the inner surface of the lid 14, a first extension 45 extending from the joint 41 along the long side wall 16a, and a second extension 43 extending from the joint 41 along the long side wall 16b. The joint portion 41 has a first engaging protrusion 48, a second engaging protrusion 49, a protrusion 47 protruding from the lower surface of the joint portion 41, and a female screw portion 42 formed by penetrating the joint portion 41 and the protrusion 47. The first engaging protrusion 48 abuts against the upper surface 53 of one insulator 50, and the second engaging protrusion 49 abuts against the upper surface 53 of the other insulator 50, thereby holding the positive electrode lead 40A to each insulator 50. The outer surface 45a of the first extending portion 45 abuts against the inner surface 52 of one insulator 50, and the outer surface of the second extending portion 43 abuts against the inner surface 52 of the other insulator 50. The positive electrode lead 40A is engaged with the insulator 50 by the abutment of the outer surfaces 43a of the first extending portion 45 and the second extending portion 43 with the inner surface 52 of the insulator 50. The output terminal 20 has a first male threaded portion 20a, a second male threaded portion 20b, and a flange portion 20c located between the first male threaded portion and the second male threaded portion. The first male thread portion 20a is screwed into the female thread portion 42 of the positive electrode lead 40A through the through hole 26 of the lid body 14 until the flange portion 20c abuts against the outer surface of the lid body 14. As a result, the output terminal 20 and the positive electrode lead 40A are fixed to the outer surface and inner surface of the lid body 14, respectively, and the output terminal 20 is electrically connected to the positive electrode lead 40A.

[0025] The effects of the secondary battery according to the first embodiment will be described. 2 and 9, the secondary battery 10 includes an outer container 12, an electrode assembly 30, an output terminal 20, leads (a positive electrode lead 40A and a negative electrode lead 40B), and a pair of insulators 50. The leads have a first extending portion 45 and a second extending portion 43 that engage with the inner surface 52 of each insulator 50. This prevents the leads from shifting due to the biasing force of the positive electrode current collector tab 32a and the negative electrode current collector tab 32b, and allows the lid 14 to be stably fixed to the container body 16.

[0026] As shown in Figure 6, by attaching adhesive material 38 to a pair of side surfaces 31 of the electrode body 30 and the outer surface 54 of the insulator 50, the electrode body 30 and the insulator 50 can be maintained in an integrated state, making it easier to store them in the container body 16. 3, 4, and 5, by providing the first engaged portion 46 and the second engaged portion 44 on the leads and providing engaging protrusions 60 on each insulator 50, it becomes easy to determine the position of the leads and to connect them to the output terminals 20. In other words, it is possible to obtain a secondary battery that is easy to assemble.

[0027] (Second embodiment) The secondary battery according to the second embodiment will be described below. 10 is a perspective view showing an electrode body 30, a positive electrode lead 40A, a negative electrode lead 40B, and an insulator 50 according to the second embodiment. The secondary battery 10 has the same configuration as that of the first embodiment, except for the configuration described in the second embodiment. As shown in FIG. 10, the secondary battery according to the second embodiment is configured without an adhesive member 38. The electrode body 30 and each insulator 50 are fixed together by an adhesive 39. The adhesive 39 is provided between the electrode body 30 and each insulator 50 in the height direction Z.

[0028] According to the second embodiment configured as described above, the electrode body 30 and the insulator 50 can be maintained in an integrated state, which makes it easy to store them in the container body 16. In other words, it is possible to obtain a secondary battery that is easy to assemble.

[0029] Although several embodiments of the present invention have been described, these embodiments are presented as examples and are not intended to limit the scope of the invention. These novel embodiments can be embodied in various other forms, and various omissions, substitutions, and modifications can be made without departing from the spirit of the invention. These embodiments and their modifications are included within the scope and spirit of the invention, as well as within the scope of the invention and its equivalents as set forth in the claims. Multiple embodiments can also be combined as necessary. [Explanation of symbols]

[0030] 10... Secondary battery, 12... Outer container, 14... Lid, 16... Container body, 16a, 16b... Long side walls, 20... Output terminal, 30... Electrode body, 31... Side, 32a... Positive electrode current collecting tab, 32b... Negative electrode current collecting tab, 38... Adhesive member, 39... Adhesive, 40A... Positive electrode lead, 40B... Negative electrode lead, 41... Joint portion, 43... Second extension portion, 44... Second engaged portion, 45... First extension portion, 46... First engaged portion, 50... Insulator, 52... Inner surface, 53... Upper surface, 54... Outer surface, 58... Rib, 60... Engagement protrusion

Claims

1. a pair of long side walls opposed to each other at a distance; and a lid body fixed to one end of the pair of long side walls; an outer container having an electrode assembly having a current collecting tab and housed in the outer container; an output terminal provided on the cover; a lead provided between the electrode body and the lid body inside the outer container, electrically connecting the output terminal and the current collecting tab, the lead having: a joint portion facing the lid body and connected to the output terminal; a first extension portion extending from the joint portion along the inner surface of one of the long side walls; and a second extension portion extending from the joint portion along the inner surface of the other long side wall; a first insulator provided inside the outer container between the electrode body and the lid body, disposed opposite an inner surface of one of the long side walls, and having an inner surface engaged with an outer surface of the first extension portion; a second insulator provided inside the outer container between the electrode body and the lid body, disposed opposite the inner surface of the other long side wall, and having an inner surface engaged with the outer surface of the second extension portion; an adhesive member bonded to a pair of side surfaces of the electrode body and outer surfaces of the first insulator and the second insulator facing the long side wall; Secondary battery.

2. the first insulator and the second insulator each have an engaging protrusion protruding from the inner surface, The first extending portion and the second extending portion of the lead each have an engaged portion that engages with the engaging protrusion. The secondary battery according to claim 1 .

3. A secondary battery as described in claim 1 or 2, wherein the adhesive member is an adhesive tape.

4. the first insulator and the second insulator each have a rib protruding from the inner surface, The adhesive tape is attached to the first insulator and the second insulator, overlapping the rib. The secondary battery according to claim 3 .

5. the first insulator and the second insulator are fixed to the electrode body with an adhesive. The secondary battery according to claim 1 or 2.

6. The engaged portion is a through hole formed through the first extending portion or the second extending portion. The secondary battery according to claim 2 .

7. The engaged portion is an engagement groove formed by recessing a side edge of the first extending portion or the second extending portion. The secondary battery according to claim 2 .

8. a pair of long side walls opposed to each other at a distance; and a lid body fixed to one end of the pair of long side walls; an outer container having an electrode assembly having a current collecting tab and housed in the outer container; an output terminal provided on the cover; a lead provided between the electrode body and the lid body inside the outer container, electrically connecting the output terminal and the current collecting tab, the lead having: a joint portion facing the lid body and connected to the output terminal; a first extension portion extending from the joint portion along the inner surface of one of the long side walls; and a second extension portion extending from the joint portion along the inner surface of the other long side wall; a first insulator provided between the electrode body and the lid body inside the outer container, disposed opposite to the inner surface of one of the long side walls, and having an inner surface engaged with the outer surface of the first extension portion and an engaging protrusion protruding from the inner surface; a second insulator provided between the electrode body and the lid body inside the outer container, disposed opposite the inner surface of the other long side wall, and having an inner surface engaged with the outer surface of the second extension portion and an engaging protrusion protruding from the inner surface, the first extending portion and the second extending portion of the lead each have an engaged portion that engages with the engaging protrusion, and the engaged portion is a through hole formed by penetrating the first extending portion or the second extending portion; Secondary battery.

9. a pair of long side walls opposed to each other at a distance; and a lid body fixed to one end of the pair of long side walls; an outer container having an electrode assembly having a current collecting tab and housed in the outer container; an output terminal provided on the cover; a lead provided between the electrode body and the lid body inside the outer container, electrically connecting the output terminal and the current collecting tab, the lead having: a joint portion facing the lid body and connected to the output terminal; a first extension portion extending from the joint portion along the inner surface of one of the long side walls; and a second extension portion extending from the joint portion along the inner surface of the other long side wall; a first insulator provided between the electrode body and the lid body inside the outer container, disposed opposite to the inner surface of one of the long side walls, and having an inner surface engaged with the outer surface of the first extension portion and an engaging protrusion protruding from the inner surface; a second insulator provided between the electrode body and the lid body inside the outer container, disposed opposite the inner surface of the other long side wall, and having an inner surface engaged with the outer surface of the second extension portion and an engaging protrusion protruding from the inner surface, the first extending portion and the second extending portion of the lead each have an engaged portion that engages with the engaging protrusion, and the engaged portion is an engaging groove formed by recessing a side edge of the first extending portion or the second extending portion; Secondary battery.

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