Secondary batteries

Abstract

To improve sealability inside a battery case.SOLUTION: A lithium ion battery 10 includes: a battery case 12 which has a first through-hole 20A and houses an electrode body 70; a flexible inner insulation member 50 which is provided so as to be in contact with the battery case 12 and has a second through-hole 52A; a collector terminal 60 which is provided inside the battery case 12 and has a third through-hole 62A; an external terminal 30 which is inserted into the first through-hole 20A, the second through-hole 52A, and the third through-hole 62A so as to sandwich the collector terminal 60, the battery case 12, and the inner insulation member 50; and a protrusion 56 which is provided so as to interfere with the external terminal 30 while protruding radially inside over the entire part of an inner circumferential surface of the second through-hole 52A, and which is bent when the external terminal is inserted into the second through-hole 52A.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a secondary battery.

Background Art

[0002] It is known that a secondary battery includes an external terminal connected to a current collecting terminal joined to an electrode body housed inside a battery case, and drawn out to the outside of the battery case through a through hole of the battery case (see, for example, Patent Document 1).

[0003] Patent Document 1 discloses a sealed battery including: a battery case having a terminal lead-out hole; an electrode terminal having a rivet portion protruding from a pedestal portion; and a sealing member that seals a gap between the case and the electrode terminal, wherein a tip end of the rivet portion is caulked at a constant pressure so as to compress a flat plate portion in a terminal axial direction.

[0004] By the way, in a secondary battery, it is preferable to improve the sealing performance inside the battery case.

Prior Art Literature

Patent Literature

[0005]

Patent Document 1

Summary of the Invention

Problem to be Solved by the Invention

[0006] An object of the present invention, in consideration of the above facts, is to provide a secondary battery with improved sealing performance inside the battery case.

Means for Solving the Problem

[0007] A secondary battery according to a first aspect of the present invention comprises: a battery case having a first through-hole and housing an electrode body; a flexible insulating member provided in contact with the battery case and having a second through-hole; a current collector terminal provided on the inside of the battery case and having a third through-hole; an external terminal inserted into the first through-hole, the second through-hole and the third through-hole, sandwiching the current collector terminal, the battery case and the insulating member; and a protrusion on the inner circumferential surface of the second through-hole, projecting radially inward over its entire circumference, and provided so as to interfere with the external terminal, and which bends when the external terminal is inserted into the second through-hole.

[0008] In a secondary battery according to a second aspect of the present invention, the protrusion is provided on the exit side of the second through hole in the insertion direction of the external terminal, as in the secondary battery according to the first aspect of the present invention.

[0009] In a secondary battery according to a third aspect of the present invention, in a secondary battery according to the first or second aspect of the present invention, the protrusion is provided in a position that does not protrude from the insulating member when the external terminal is inserted into the second through hole and bends.

[0010] In the secondary battery of the fourth aspect of the present invention, in any one of the secondary batteries of the first to third aspects of the present invention, the inlet side of the second through hole is formed to have a larger diameter than the outlet side of the second through hole in the insertion direction of the external terminal.

[0011] In the fifth embodiment of the present invention, in the secondary battery of any one of the first to fourth embodiments of the present invention, the external terminal is inserted from the outside to the inside of the battery case.

[0012] In the sixth embodiment of the present invention, in the secondary battery according to any one of the first to fifth embodiments of the present invention, the insulating member on which the protrusion is provided is located inside the battery case. [Effects of the Invention]

[0013] In the secondary battery according to the first aspect of the present invention, a protrusion is provided on the inner circumferential surface of the second through-hole, projecting radially inward along its entire circumference and interfering with the external terminal, and bending when the external terminal is inserted into the second through-hole. As a result, when the external terminal is inserted into the second through-hole, the protrusion bends in the direction of insertion of the external terminal. Therefore, the insulating member is attached in close contact with the external terminal. Consequently, the airtightness inside the battery case can be improved.

[0014] In the secondary battery according to the second aspect of the present invention, the protrusion is provided on the exit side of the second through-hole in the direction of insertion of the external terminal, so that the inlet side of the second through-hole has a larger diameter than the exit side in the direction of insertion of the external terminal. Therefore, it is possible to easily insert the external terminal into the second through-hole.

[0015] In the secondary battery according to the third aspect of the present invention, the protrusion is positioned so that it does not protrude from the insulating member when the external terminal is inserted into the second through-hole and bends. As a result, when the external terminal is inserted into the second through-hole and the protrusion bends in the direction of insertion of the external terminal, the bent protrusion does not protrude from the insulating member. Therefore, interference between the bent protrusion and the current collection terminal can be prevented. Consequently, the current collection terminal can be positioned at the desired location.

[0016] In the secondary battery according to the fourth aspect of the present invention, in the direction of insertion of the external terminals, the inlet side of the second through-hole is formed to have a larger diameter than the outlet side of the second through-hole, thereby making it easier to insert the external terminals into the second through-hole.

[0017] In the fifth embodiment of the present invention, the external terminals are inserted from the outside to the inside of the battery case, causing the protrusions to bend inward towards the inside of the battery case. Therefore, compared to the case where the protrusions bend outward towards the outside of the battery case, leakage of electrolyte from the inside of the battery case can be suppressed.

[0018] In the secondary battery according to the sixth aspect of the present invention, the insulating member provided with the convex portion is disposed inside the battery case, whereby the insulating member and the external terminal are in close contact with each other inside the battery case. Therefore, leakage of the electrolytic solution inside the battery case can be further suppressed. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] [Figure 1] FIG. 1 is an exploded perspective view showing the lithium ion battery according to the present embodiment. [Figure 2] FIG. 2 is a cross-sectional view schematically showing the cap assembly according to the present embodiment, showing the A-A cross-section of FIG. 1. [Figure 3] FIG. 3 is an exploded cross-sectional view showing the cap assembly according to the present embodiment. [Figure 4] FIGS. 4(A) and 4(B) are cross-sectional views schematically showing the insulating member and the external terminal according to the present embodiment, wherein FIG. 4(A) shows a state before the external terminal is inserted into the second through hole of the insulating member, and FIG. 4(B) shows a state after the external terminal is inserted into the second through hole of the insulating member. [Figure 5] FIG. 5 is a view for explaining a method of assembling the cap assembly according to the present embodiment. [Figure 6] FIG. 6 is a cross-sectional view showing a cap assembly according to a comparative example. [Figure 7] FIGS. 7(A) and 7(B) are cross-sectional views schematically showing an insulating member and an external terminal according to another embodiment, wherein FIG. 7(A) shows a state before the external terminal is inserted into the second through hole of the insulating member, and FIG. 7(B) shows a state after the external terminal is inserted into the second through hole of the insulating member. [Figure 8] FIG. 8 is a cross-sectional view schematically showing a cap assembly according to another embodiment. DESCRIPTION OF EMBODIMENTS

[0020] The secondary battery according to this embodiment will be described below with reference to the drawings. The secondary battery according to this embodiment will be described as a lithium-ion battery that constitutes a battery pack used as an on-board power source for vehicles such as electric vehicles and hybrid vehicles. In each figure, arrow D indicates the longitudinal direction D of the lithium-ion battery 10, arrow E indicates the width direction E of the lithium-ion battery 10, and arrow F indicates the vertical direction F of the lithium-ion battery 10. When simply describing the outside and inside, unless otherwise specified, it refers to the lid member 20 of the battery case 12.

[0021] [Composition of Lithium-ion Battery 10] As shown in Figures 1 and 2, the lithium-ion battery 10 includes a battery case 12, a lid assembly 14, an electrode body 70, and an insulating film 80.

[0022] (Battery case 12) The battery case 12 includes a housing 15 and a lid member 20.

[0023] <Containment Unit 15> The housing 15 is made of aluminum, for example, and is formed in the shape of a rectangular box that is long in the longitudinal direction D and has an open top.

[0024] <Lid member 20> The lid member 20 is made of, for example, aluminum and is formed in the shape of a rectangular plate extending in the longitudinal direction D. The lid member 20 is provided with a safety valve 22, an inlet 24, and a first through hole 20A.

[0025] The safety valve 22 is located near the center of the lid member 20 in the longitudinal direction D. The safety valve 22 opens when the internal pressure of the battery case 12 reaches a predetermined pressure, and discharges the gas generated inside the battery case 12.

[0026] The filling port 24 is located near the safety valve 22 and is formed as a through-hole that penetrates the lid member 20 in the thickness direction. The filling port 24 is used when injecting electrolyte into the battery case 12. A cap 26 is attached to the filling port 24, sealed airtightly, for example by laser welding.

[0027] The first through-hole 20A is formed to penetrate the lid member 20 in the thickness direction. The first through-hole 20A is provided on one end and the other end of the lid member 20 in the longitudinal direction D. The first through-hole 20A has an inner diameter slightly larger than the outer diameter of the inner flange portion 46 of the outer insulating member 40, which will be described later.

[0028] With the electrode body 70, insulating film 80, current collector terminal 60, and inner insulating member 50 housed inside the housing 15, the lid member 20 is attached, for example, by laser welding, to close the opening of the housing 15.

[0029] (electrode body 70) As shown in Figure 1, the electrode body 70 is formed by winding together a positive electrode sheet, a negative electrode sheet, and a separator sheet in a laminated state, so that its cross-section is flattened. The electrode body 70 includes a power generator 72, a positive electrode current collector 76, and a negative electrode current collector 74.

[0030] The power generator 72 is formed by laminating a region of a positive electrode sheet coated with positive electrode active material, a region of a negative electrode sheet coated with negative electrode active material, and a separator sheet. The power generator 72 has the function of storing electrical energy from the lithium-ion battery 10.

[0031] The positive electrode current collector 76 is formed by winding a positive electrode sheet without being coated with an active material. The negative electrode current collector 74 is formed by winding a negative electrode sheet without being coated with an active material.

[0032] (Insulating film 80) The insulating film 80 is formed in the shape of a bag that opens to the opening side of the housing 15, using an insulating material such as polypropylene. The insulating film 80 is housed in the battery case 12 together with the electrode body 70, so that the electrode body 70 and the housing 15 are insulated from each other.

[0033] (Lid assembly 14) The cover assembly 14 includes an external terminal 30, an outer insulating member 40 as an insulating member, an inner insulating member 50 as an insulating member, a cover member 20, and a current collection terminal 60.

[0034] A positive terminal 16 is provided at one end of the battery case 12 in the longitudinal direction D, and a negative terminal 17 is provided at the other end of the battery case 12 in the longitudinal direction D. The external terminal 30 and current collector terminal 60 constituting the positive terminal 16 are made of, for example, aluminum, and the external terminal 30 and current collector terminal 60 constituting the negative terminal 17 are made of, for example, copper. Since the positive terminal 16 and the negative terminal 17 have similar configurations except for the difference in the materials of the external terminal 30 and current collector terminal 60, the positive terminal 16 will be described in detail below.

[0035] (External terminal 30) As shown in Figures 2 and 3, the external terminal 30 comprises a seat portion 32 and a shaft portion 34.

[0036] The base portion 32 is formed in the shape of a rectangular plate with the vertical direction F being the thickness direction, and is positioned on the outside of the battery case 12. The shaft portion 34 is formed in the shape of a cylinder extending downward from the center of the lower surface of the base portion 32, and is inserted from the outside of the battery case 12 into the first through hole 20A of the lid member 20, extending into the inside of the battery case 12. The tip (lower end) of the shaft portion 34 is provided with a crimped portion 36 to which the tip of the shaft portion 34 is crimped.

[0037] (Outer insulating member 40) The outer insulating member 40 is made of an insulating material such as fluororesin, and is positioned on the outside of the battery case 12, in contact with the lid member 20. The outer insulating member 40 is rectangular in shape when viewed from the vertical direction F. The outer insulating member 40 has a main body portion 42, an outer flange portion 44, an inner flange portion 46, and a fourth through hole 46A.

[0038] The main body portion 42 is formed in the shape of a rectangular plate with the vertical direction F being the thickness direction. A circular fourth through hole 46A is formed in the center of the main body portion 42, penetrating in the thickness direction of the main body portion 42. The fourth through hole 46A is formed with an inner diameter L1 (for example, 4.0 mm) that is slightly larger than the outer diameter of the shaft portion 34 of the external terminal 30.

[0039] The shaft portion 34 of the external terminal 30 is inserted into the fourth through-hole 46A of the outer insulating member 40. The seat portion 32 of the external terminal 30 is installed on the main body portion 42 of the outer insulating member 40.

[0040] The outer flange portion 44 is formed in a rib shape that extends upward from the outer peripheral edge of the main body portion 42. The outer flange portion 44 is positioned to surround the outer circumference of the seat portion 32 of the external terminal 30.

[0041] The inner flange portion 46 is formed in a rib shape that extends downward from the inner peripheral edge of the main body portion 42. The inner flange portion 46 is inserted into the first through hole 20A of the lid member 20.

[0042] (Inner insulating member 50) The inner insulating member 50 is made of a liquid-resistant, flexible, and insulating material such as polyphenylene sulfide, and is positioned inside the battery case 12 in contact with the lid member 20. The inner insulating member 50 is rectangular in shape when viewed from the vertical direction F. The inner insulating member 50 has a main body portion 52, an outer flange portion 54, a second through hole 52A, and a protrusion portion 56.

[0043] The main body portion 52 is formed in a rectangular plate shape with the vertical direction F being the plate thickness direction. A circular second through hole 52A is formed in the center of the main body portion 52, penetrating in the plate thickness direction of the main body portion 52. The second through hole 52A is formed with an inner diameter L1 (for example, 4.0 mm) that is slightly larger than the outer diameter of the shaft portion 34 of the external terminal 30.

[0044] The outer flange portion 54 is formed in a rib shape that extends downward from the outer peripheral edge of the main body portion 52. The outer flange portion 54 is arranged to surround the outer circumference of the base portion 62 of the current collection terminal 60, which will be described later.

[0045] <Protrusion 56> As shown in Figure 4(A), the protrusion 56 is formed in a rectangular cross-section that protrudes radially inward along the entire circumference of the inner surface of the second through-hole 52A. In the vertical direction F, the protrusion 56 is located below the middle of the second through-hole 52A. In the insertion direction G of the external terminal 30, the protrusion 56 is located on the exit side (lower side) of the second through-hole 52A.

[0046] The presence of the protrusion 56 ensures that, in the insertion direction G of the external terminal 30, the entrance side (upper side) of the second through hole 52A has a larger diameter than the exit side (lower side) of the second through hole 52A.

[0047] The protrusion 56 is formed to interfere with the shaft portion 34, which is inserted into the second through hole 52A, for a predetermined length W (e.g., 10 μm). The thickness T2 (e.g., 1 μm) of the protrusion 56 is formed to be thinner than the thickness T1 (e.g., 0.6 mm) of the main body portion 52.

[0048] As shown in Figure 4(B), the protrusion 56 is positioned so that when the shaft portion 34 of the external terminal 30 is inserted into the second through-hole 52A from the outside to the inside of the battery case 12 and bends, it does not protrude downward from the lower surface of the inner insulating member 50.

[0049] (Collection terminal 60) As shown in Figures 1 and 2, the current collector terminal 60 is located inside the battery case 12, in contact with the lower surface of the main body portion 52 of the inner insulating member 50. The current collector terminal 60 has a base portion 62 and a connecting piece 64.

[0050] As shown in Figures 2 and 3, the base portion 62 is formed in the shape of a rectangular plate with the vertical direction F being the thickness direction. A circular third through-hole 62A is formed in the center of the base portion 62, penetrating through the base portion 62 in the thickness direction. The third through-hole 62A is formed with an inner diameter L2 (for example, 4.0 mm) that is slightly larger than the outer diameter of the shaft portion 34 of the external terminal 30.

[0051] As shown in Figure 1, the connecting piece 64 is formed in the shape of a rectangular plate with the width direction E as the plate thickness direction. The connecting piece 64 of the positive electrode terminal 16 is joined to the positive electrode current collector portion 76 of the electrode body 70, for example, by resistance welding. The connecting piece 64 of the negative electrode terminal 17 is joined to the negative electrode current collector portion 74 of the electrode body 70, for example, by resistance welding.

[0052] [How to assemble the lid assembly 14] As shown in Figure 5, the external terminal 30 is fixed to the jig 2 with the tip of the shaft portion 34 facing upward. Next, the outer insulating member 40 is moved from top to bottom and the shaft portion 34 is inserted into the fourth through hole 46A of the outer insulating member 40. Next, the cover member 20 is moved from top to bottom and the shaft portion 34 and the inner flange portion 46 are inserted into the first through hole 20A of the cover member 20.

[0053] Next, the inner insulating member 50 is moved from top to bottom, and the shaft portion 34 is inserted into the second through hole 52A of the inner insulating member 50. At this time, as shown in Figure 4(B), the protrusion 56 collides with the shaft portion 34 of the external terminal 30 and bends toward the exit side in the insertion direction G.

[0054] Next, as shown in Figure 5, the current collector terminal 60 is moved from top to bottom, and the shaft portion 34 is inserted into the third through hole 62 of the base portion 62 of the current collector terminal 60.

[0055] Next, as shown in Figure 2, the tip of the shaft portion 34 of the external terminal 30 is crimped to form a crimped portion 36, thereby forming the lid assembly 14. In the lid assembly 14, the current collector terminal 60, the inner insulating member 50, the lid member 20, and the outer insulating member 40 are sandwiched between the seat portion 32 and the crimped portion 36 of the external terminal 30.

[0056] [Lithium-ion battery operation 10] In the lithium-ion battery 10 configured as described above, the output of the electrode body 70 is taken out from the external terminal 30 and used as a power source for electric vehicles, hybrid vehicles, etc.

[0057] [Effect] The lithium-ion battery 10 of this embodiment includes a battery case 12 having a first through-hole 20A and housing an electrode body 70; an inner insulating member 50 that is in contact with the battery case 12, has a second through-hole 52A and is flexible; a current collector terminal 60 provided inside the battery case 12 and having a third through-hole 62A; an external terminal 30 that is inserted into the first through-hole 20A, the second through-hole 52A and the third through-hole 62A and sandwiches the current collector terminal 60, the battery case 12 and the inner insulating member 50; and a protrusion 56 that protrudes radially inward along the entire circumference of the inner surface of the second through-hole 52A and is provided so as to interfere with the external terminal 30, and which bends when the external terminal is inserted into the second through-hole 52A (see Figure 2).

[0058] The inner surface of the second through-hole 52A is provided with a projection 56 that extends radially inward along its entire circumference and interferes with the external terminal 30, and which flexes when the external terminal 30 is inserted into the second through-hole 52A. As a result, when the external terminal 30 is inserted into the second through-hole 52A, the projection 56 flexes in the insertion direction G of the external terminal 30. Therefore, the inner insulating member 50 is attached in close contact with the external terminal 30. Consequently, the airtightness inside the battery case 12 can be improved.

[0059] By the way, as shown in Figure 6, if the protrusion 56 is not provided in the second through hole 52A, the inner insulating member 50 may be positioned misaligned with the outer terminal 30. In that case, the current collector terminal 60 may ride up on a protrusion such as the outer flange portion 54 provided on the inner insulating member 50, and there is a problem that the current collector terminal 60 cannot be positioned in the desired location.

[0060] In this embodiment, the inner circumferential surface of the second through-hole 52A is provided with a protrusion 56 that projects radially inward along its entire circumference and interferes with the external terminal 30, and which flexes when the external terminal 30 is inserted into the second through-hole 52A. As a result, when the external terminal 30 is inserted into the second through-hole 52A, the inner insulating member 50 is positioned at the desired location relative to the external terminal 30. Therefore, the current collector terminal 60 can be mounted in the desired location relative to the inner insulating member 50.

[0061] In the lithium-ion battery 10 of this embodiment, the protrusion 56 is provided on the exit side of the second through-hole 52A in the insertion direction G of the external terminal 30 (see Figure 3).

[0062] The protrusion 56 is provided on the exit side of the second through-hole 52A in the insertion direction G of the external terminal 30. As a result, in the insertion direction G of the external terminal 30, the inlet side of the second through-hole 52A has a larger diameter than the exit side of the second through-hole 52A. Therefore, it is possible to easily insert the external terminal 30 into the second through-hole 52A.

[0063] In the lithium-ion battery 10 of this embodiment, the protrusion 56 is positioned so that it does not protrude from the inner insulating member 50 when the external terminal 30 is inserted into the second through hole 52A and bends (see Figure 4B).

[0064] The protrusion 56 is positioned so that it does not protrude from the inner insulating member 50 when the external terminal 30 is inserted into the second through hole 52A and bends. As a result, when the external terminal 30 is inserted into the second through hole 52A and the protrusion 56 bends in the insertion direction G of the external terminal 30, the bent protrusion 56 does not protrude from the inner insulating member 50. Therefore, interference between the bent protrusion 56 and the current collection terminal 60 can be prevented. Consequently, the current collection terminal 60 can be positioned at the desired location.

[0065] In the lithium-ion battery 10 of this embodiment, in the insertion direction G of the external terminal 30, the inlet side of the second through hole 52A is formed to have a larger diameter than the outlet side of the second through hole 52A (see Figure 4A).

[0066] In the insertion direction G of the external terminal 30, the inlet side of the second through hole 52A is formed with a larger diameter than the outlet side of the second through hole 52A, thereby making it easier to insert the external terminal 30 into the second through hole 52A.

[0067] In the lithium-ion battery 10 of this embodiment, the external terminals 30 are inserted from the outside to the inside of the battery case 12 (see Figure 3).

[0068] Because the external terminal 30 is inserted from the outside to the inside of the battery case 12, the protrusion 56 bends toward the inside of the battery case 12. Therefore, compared to the case where the protrusion 56 bends toward the outside of the battery case 12, leakage of electrolyte from the inside of the battery case 12 can be suppressed. In addition, because the external terminal 30 is inserted from the outside to the inside of the battery case 12, a shape can be formed on the seat portion 32 of the external terminal 30 for welding a busbar.

[0069] In the lithium-ion battery 10 of this embodiment, the inner insulating member 50, which is provided with the protrusion 56, is located inside the battery case 12 (see Figure 2).

[0070] The inner insulating member 50, which has a protrusion 56, is provided on the inside of the battery case 12, so that the inner insulating member 50 and the external terminal 30 are in close contact on the inside of the battery case 12. Therefore, leakage of electrolyte from the inside of the battery case 12 can be further suppressed.

[0071] The secondary battery of the present invention has been described above based on the above embodiments. However, the specific configuration is not limited to these embodiments, and changes to the design are permitted as long as they do not deviate from the gist of the invention as described in each claim of the patent claims.

[0072] In the above embodiment, the protrusion 56 is shown as being provided on the exit side (lower side) of the second through hole 52A in the insertion direction G of the external terminal 30. However, the protrusion may also be provided on the entrance side of the second through hole 52A in the insertion direction G of the external terminal 30.

[0073] In the above embodiment, the protrusion 56 was shown as being formed in a rectangular cross-section projecting radially inward. However, as shown in Figure 7(A), the protrusion 156 may be formed in a triangular cross-section projecting radially inward. In this case, as shown in Figure 7(B), when the shaft portion 34 of the external terminal 30 is inserted into the second through hole 52A, the protrusion 156 bends toward the exit side in the insertion direction G.

[0074] In the above embodiment, the protrusion 56 is shown as being provided on the inner insulating member 50. However, as shown in Figure 8(A), the protrusion 248 can also be provided on the outer insulating member 40. In this case, the protrusion 248 can be provided on the exit side of the fourth through hole 46A in the insertion direction G of the external terminal 30.

[0075] In the above embodiment, the inner flange portion 46 inserted into the first through hole 20A of the lid member 20 is shown to be provided on the outer insulating member 40. However, as shown in Figure 8(B), the inner flange portion 358 inserted into the first through hole 20A of the lid member 20 may be provided on the inner insulating member 50.

[0076] In the above embodiment, an example was shown in which the tip of the shaft portion 34 of the external terminal 30 is crimped to form a crimped portion 36. However, the tip of the shaft portion 34 of the external terminal 30 can also be fastened by other fastening methods such as a nut.

[0077] In the above embodiment, the external terminal 30 was shown as being inserted from the outside to the inside of the battery case 12. However, the external terminal may also be inserted from the inside to the outside of the battery case.

[0078] In the above embodiment, the electrode body 70 was shown as being formed by winding to create a flattened cross-section. However, the electrode body may also be a laminated type in which a positive electrode sheet, a negative electrode sheet, and a separator sheet are stacked.

[0079] In the above embodiment, the secondary battery is shown as a lithium-ion battery that constitutes a battery pack used as an on-board power source for electric vehicles, hybrid vehicles, etc. However, the secondary battery is not limited to this embodiment and may be other secondary batteries such as nickel-metal hydride batteries. [Explanation of symbols]

[0080] 10. Lithium-ion battery (an example of a rechargeable battery) 12 Battery Case 20A 1st through hole 30 External terminals 50. Inner insulating material (an example of an insulating material) 52A 2nd through hole 56 Convex part 60 Current collector terminal 62A Third through hole 70 Electrode body G Insertion direction

Claims

1. A battery case having a first through-hole and housing an electrode body, A flexible insulating member having a main body portion that is in contact with the battery case and has a second through-hole formed therein, A current collection terminal having a third through-hole is provided inside the aforementioned battery case, It has a shaft portion that is inserted into the first through hole, the second through hole and the third through hole, and an external terminal that sandwiches the current collection terminal, the battery case and the insulating member, Equipped with, A secondary battery comprising an annular protrusion which bends when the external terminal is inserted into the second through hole, with the external terminal in contact with the outer surface of the shaft when the external terminal is inserted into the second through hole, and the end face on the current collection terminal side faces the annular space formed between the current collection terminal and the external terminal.

2. The aforementioned protrusion is provided on the exit side of the second through hole in the insertion direction of the external terminal. The secondary battery according to claim 1.

3. The aforementioned protrusion is positioned so that it does not protrude from the main body toward the current collection terminal when the external terminal is inserted into the second through hole and bends. The secondary battery according to claim 1.

4. In the insertion direction of the external terminal, the entrance side of the second through-hole is formed to have a larger diameter than the exit side of the second through-hole. The secondary battery according to claim 1.

5. The external terminal is inserted into the battery case from the outside toward the inside. The secondary battery according to claim 1.

6. The insulating member on which the protrusion is provided is located inside the battery case. The secondary battery according to claim 1.

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