Button-type secondary batteries

Abstract

The present invention relates to a button-type secondary battery, which includes: an electrode assembly; a lower can, which is used to accommodate the electrode assembly; an upper can, which is connected to the opening of the lower can; a gasket, which is used to provide electrical insulation between the lower can and the upper can; a first joint portion, which connects the first electrode of the electrode assembly to the lower can; and a second joint portion, which connects the second electrode of the electrode assembly to the upper can, wherein the second joint portion includes a second electrode joint and a second lead joint, the second electrode joint is connected to the second electrode, and the second lead joint connects the second electrode joint to the upper can.

Description

Technical Field

[0001] The present invention relates to a button-type secondary battery, and more particularly, to a button-type secondary battery in which an electrode tab disposed in an electrode assembly can be selectively extended in length. Background Art

[0002] Generally speaking, secondary batteries are rechargeable and dischargeable, unlike primary batteries, which are non-rechargeable. They are widely used in mobile phones, notebook computers, camcorders, electric vehicles, and the like.

[0003] Secondary batteries include button-type secondary batteries with high energy density, high output, and long life. The button-type secondary battery includes an electrode assembly, a lower can having a receiving groove for receiving the electrode assembly, an upper can coupled to the lower can to complete the receiving groove, and a gasket that seals the gap between the lower can and the upper can.

[0004] In addition, the electrode assembly has a structure in which the first electrode and the second electrode are sequentially stacked with the separator between the first electrode and the second electrode. Here, the first electrode is provided with a first electrode tap connected to the lower tank, and the second electrode is provided with a second electrode tap connected to the upper tank.

[0005] Here, one end of the second electrode tap is coupled to a distal end of a second electrode disposed on an outer surface of the electrode assembly, and the other end of the second electrode tap is coupled to a bottom surface of the upper can.

[0006] However, the second electrode tap is ensured to be as long as a set length for connecting the second electrode of the electrode assembly to the upper can. In this case, there is a problem that the second electrode is bent or folded due to the weight of the second electrode tap having the required length. Summary of the Invention

[0007] Technical issues

[0008] The present invention is invented to solve the above problems, and an object of the present invention is to provide a button-type secondary battery, in which the electrode connector is improved to be able to selectively extend in length to prevent deformation of the electrode assembly, and to fully ensure the length of the electrode connector to stably connect the electrode assembly to the upper can.

[0009] Technical Solution

[0010] A button-type secondary battery according to the present invention for achieving the above purpose includes: an electrode assembly; a lower can, which is configured to accommodate the electrode assembly; an upper can, which is connected to the opening of the lower can; a gasket, which is configured to insulate the lower can and the upper can from each other; a first joint portion, which is configured to connect the first electrode of the electrode assembly to the lower can; and a second joint portion, which is configured to connect the second electrode of the electrode assembly to the upper can, wherein the second joint portion includes a second electrode joint and a second lead joint, and the second electrode joint is connected to the second electrode, and the second lead joint connects the second electrode joint to the upper can.

[0011] A length of the second electrode tab may be smaller than a length of the second lead tab.

[0012] The thickness of the second electrode tab may be smaller than the thickness of the second lead tab.

[0013] The second electrode tap and the second lead tap may be coupled to each other by welding in a state in which end portions of the second electrode tap and the second lead tap corresponding to each other are disposed to partially overlap each other.

[0014] An overlapping portion of the second electrode tab and the second lead tab may have a length of 1.5 mm to 10.0 mm.

[0015] A protection member having insulation properties may be attached to coupling portions of the second electrode tap and the second lead tap.

[0016] The second electrode tab may include a rear end coupled to the second electrode of the electrode assembly, a front end coupled to the second lead tab, and a lead-out end disposed between the rear end and the front end and disposed on a surface of the electrode assembly corresponding to the upper can, and a length of the second electrode tab from the lead-out end to the front end may be equal to or less than a width of the second electrode tab or the second lead tab.

[0017] The second electrode tab and the second lead tab may be made of different materials from each other.

[0018] The second electrode tab may be made of a metal material that is lighter than the second lead tab.

[0019] The second lead connector may be made of a flexible metal material.

[0020] The first tab portion may include a first electrode tab and a first lead tab, and the first electrode tab may be connected to the first electrode, and the first lead tab may connect the first electrode tab to the lower can.

[0021] A length of the first electrode tab may be smaller than a length of the first lead tab.

[0022] Technical Effects

[0023] The button-type secondary battery according to the present invention may include an electrode assembly, a lower can, an upper can, a gasket, a first joint portion, and a second joint portion. The second joint portion may include a second electrode joint and a second lead joint. The second electrode joint may be connected to the second electrode of the electrode assembly, and the second lead joint may connect the second electrode joint to the upper can. Due to this characteristic, when manufacturing the electrode assembly, since only the second electrode joint of the second joint portion is connected to the second electrode, the weight of the second joint portion can be minimized to prevent the second electrode or the electrode assembly from being deformed by the second joint portion. In addition, when the electrode assembly and the upper can are coupled to each other, the length of the second joint portion can be sufficiently ensured by joining the second lead joint to the second electrode joint, thereby stably connecting the electrode assembly to the upper can. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 1 is an exploded perspective view of a button-type secondary battery according to a first embodiment of the present invention.

[0025] Figure 2 It is a cross-sectional view illustrating a state in which an upper can is opened in the button-type secondary battery according to the first embodiment of the present invention.

[0026] Figure 3 is a cross-sectional view illustrating a state in which an upper can is attached in the button-type secondary battery according to the first embodiment of the present invention.

[0027] Figure 4 is a side view illustrating another example of a second tab portion provided in the button-type secondary battery according to the embodiment of the present invention.

[0028] Figure 5 is a side view illustrating still another example of the second tab portion provided in the button-type secondary battery according to the embodiment of the present invention.

[0029] Figure 6 This is an example Figure 3 An enlarged view of a portion of .

[0030] Figure 7 is a cross-sectional view of a button-type secondary battery according to a second embodiment of the present invention.

[0031] Figure 8 is a cross-sectional view of a button-type secondary battery according to a third embodiment of the present invention.

[0032] Figure 9 is a side view of a button-type secondary battery according to a fourth embodiment of the present invention.

[0033] [Description of Reference Signs]

[0034] 100: Button-type secondary battery

[0035] 110: Electrode assembly

[0036] 111: First electrode

[0037] 112: Second electrode

[0038] 120: Lower the tank

[0039] 121: Storage tank

[0040] 130: Tank

[0041] 140: Washer

[0042] 141: Outer washer

[0043] 142: Inner washer

[0044] 143: Connecting washer

[0045] 150: First joint

[0046] 160: Second joint

[0047] 161: Second electrode connector

[0048] 162: Second lead connector

[0049] 170: Insulation tape

[0050] 180: Insulator

[0051] 190: Protective components DETAILED DESCRIPTION

[0052] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings in a manner that allows a person skilled in the art to easily implement the technical concept of the present invention. However, the present invention may be embodied in different forms and should not be construed as limited to the embodiments described herein. In the accompanying drawings, any content that is not necessary for describing the present invention will be omitted for clarity, and similar reference numerals in the drawings also represent similar elements.

[0053] [Button-Type Secondary Battery According to First Embodiment of the Present Invention]

[0054] like Figures 1 to 6As shown, a button-type secondary battery 100 according to a first embodiment of the present invention is a secondary battery having a diameter greater than its length, and includes an electrode assembly 110, a lower can 120 for accommodating the electrode assembly 110, an upper can 130 connected to an opening of the lower can 120, a gasket 140 for sealing a gap between the lower can 120 and the upper can 130 and insulating the lower can 120 from the upper can 130, a first joint portion 150 connecting the first electrode 111 of the electrode assembly 110 to the lower can 120, and a second joint portion 160 connecting the second electrode 112 of the electrode assembly to the upper can 130.

[0055] The electrode assembly 110 has a structure in which first electrodes 111 and second electrodes 112 are alternately disposed with a separator therebetween and are wound in a jelly roll shape.

[0056] Here, the distal ends of the first and second electrodes 111 and 112 are respectively disposed at the outermost sides of the electrode assembly 110. The first joint portion 150 is coupled to the distal end of the first electrode 111, and the second joint portion 160 is coupled to the distal end of the second electrode 112.

[0057] The first electrode is the negative electrode and the second electrode is the positive electrode, and vice versa.

[0058] An accommodating groove 121 accommodating the electrode assembly 110 is formed in the lower can 120 , and the first joint part 150 is coupled to a bottom surface of the accommodating groove 121 .

[0059] The upper tank 130 is coupled to the top surface of the lower tank to complete the accommodating groove 121 .

[0060] The gasket 140 is constructed to seal the gap between the lower tank and the upper tank and to insulate the lower tank and the upper tank from each other, and includes an outer gasket 141 arranged between the outer circumferential surface of the lower tank 120 and the inner circumferential surface of the upper tank 130, an inner gasket 142 in close contact with the inner circumferential surface of the lower tank 120, and a connecting gasket 143 connecting the outer gasket 141 to the inner gasket 142.

[0061] The first joint part 150 is configured to connect the first electrode provided in the electrode assembly to the lower can, and has one end coupled to the distal end of the first electrode 111 provided in the electrode assembly 110 and the other end coupled to the bottom surface of the lower can 120 .

[0062] The second joint part 160 is configured to connect the second electrode provided in the electrode assembly to the upper can, and has one end coupled to the distal end of the second electrode 112 provided in the electrode assembly 110 and the other end coupled to the upper can 130 .

[0063] Due to the weight of the second joint part 160 , the distal end of the second electrode 112 may be deformed while being bent or folded.

[0064] Therefore, the second joint portion 160 of the button-type secondary battery 100 according to the first embodiment of the present invention has a structure that can be selectively extended in length. That is, since the second joint portion 160 includes the second electrode joint and the second lead joint, deformation of the second electrode 112 is prevented and the coupling characteristics between the electrode assembly 110 and the upper can 130 are improved.

[0065] That is, the second joint part 160 has a structure in which the second electrode joint is coupled to the distal end of the second electrode 112 of the electrode assembly 110 and then the second lead joint is bonded to the second electrode joint.

[0066] For example, the second joint portion 160 has a structure including a second electrode joint 161 and a second lead joint 162. Here, the second electrode joint 161 is connected to the distal end of the second electrode 112 of the electrode assembly 110, and the second lead joint 162 connects the second electrode joint 161 to the upper can 130. In addition, the second electrode joint 161 and the second lead joint 162 can be joined to each other so that the second joint portion extends in length.

[0067] That is, second electrode tab 161 can be connected only to second electrode 112 of electrode assembly 110, significantly reducing the weight of second tab 160 and thus preventing deformation of the electrode assembly. Furthermore, when the electrode assembly and the upper can are connected to each other, second lead tab 162 can be bonded to second electrode tab 161, and then the front end of the second electrode lead can be connected to the upper can to sufficiently ensure the length of the second tab, thereby stably connecting the electrode assembly to the upper can.

[0068] More specifically, the second joint portion 160 can connect only the second electrode tab 161 to the distal end of the second electrode 112 of the electrode assembly 110, thereby minimizing the length and weight of the second joint portion 160 and preventing deformation of the distal end of the second electrode 112 of the electrode assembly 110. When it is necessary to connect the electrode assembly 110 to the upper can 130, by connecting the second lead tab 162 to the second electrode tab 161, the length of the second joint portion 160 can be extended by the length of the second lead tab 162, thereby stably connecting the electrode assembly 110 to the upper can 130.

[0069] Therefore, the button-type secondary battery 100 according to the first embodiment of the present invention may include a second tab portion 160 provided with a second electrode tab 161 and a second lead tab 162 to prevent deformation of the electrode assembly 110 , thereby stably connecting the electrode assembly 110 to the upper can 130 .

[0070] Reference Figure 3, the length of the second electrode tab 161 is less than the length of the second lead tab 162. Therefore, the length of the second electrode tab 161 coupled to the distal end of the second electrode 112 of the electrode assembly 110 can be significantly reduced to prevent deformation of the electrode assembly.

[0071] Reference Figure 4 , the thickness α1 of the second electrode tab 161 is less than the thickness β1 of the second lead tab 162. Therefore, the self-weight of the second electrode tab 161 can be significantly reduced to significantly prevent deformation of the electrode assembly.

[0072] The second electrode tab 161 and the second lead tab 162 can be made of different conductive metal materials. In other words, the second electrode tab 161 can be made of a lighter metal material than the second lead tab 162. Therefore, the weight of the second electrode tab 161 can be significantly reduced, significantly preventing deformation of the electrode assembly.

[0073] Reference Figure 5 The second electrode tab 161 and the second lead tab 162 have the same thickness, and the width α2 of the second electrode tab 161 is smaller than the width β2 of the second lead tab 162. Therefore, the weight of the second electrode tab 161 can be significantly reduced to significantly prevent deformation of the electrode assembly.

[0074] The second electrode tab 161 and the second lead tab 162 are arranged to partially overlap each other, and then the overlapping portions of the second electrode tab 161 and the second lead tab 162 can be coupled to each other by welding. Therefore, the coupling force between the second electrode tab 161 and the second lead tab 162 can be increased.

[0075] Reference Figure 4 The length of the overlapping portion A between the second electrode tab 161 and the second lead tab 162 is 1.5 mm to 10.0 mm, preferably 2.0 mm to 4.0 mm. The optimal length of the overlapping portion A is 2.5 mm. If the length of the overlapping portion A is less than 1.5 mm, welding becomes difficult. If the length of the overlapping portion A is greater than 10.0 mm, the weight of the second tab portion increases unnecessarily.

[0076] The second electrode tab 161 includes a rear end 161a connected to the distal end of the second electrode 112 disposed outside the electrode assembly 110, a front end 161b connected to the second lead tab 162, and a lead end 161c disposed between the rear end 161a and the front end 161b to match the surface of the electrode assembly 110 facing the upper can 130.

[0077] Reference Figure 6, a length α3 from the lead end 161c to the front end 161b of the second electrode tab 161 is equal to or less than the width of the second electrode tab 161 or the second lead tab 162. Specifically, the length of each of the second electrode tab 161 and the second lead tab 162 is equal to the width of the second electrode tab 161 or the second lead tab 162 to stably perform welding.

[0078] For example, the length α3 from the lead end 161c to the front end 161b of the second electrode tab 161 may be 10 mm to 40 mm. Therefore, the length of the second electrode tab 161 led out from the surface of the electrode assembly may be uniform, and as a result, product uniformity may be improved.

[0079] The length α3 from the lead end 161c to the front end 161b of the second electrode tab 161 is 30% to 50% of the diameter of the electrode assembly. Preferably, the length α3 is 40%. That is, when the length α3 from the lead end 161c to the front end 161b of the second electrode tab 161 is greater than 50% of the diameter of the electrode assembly, the weight of the second electrode tab may increase, thereby causing deformation of the electrode assembly.

[0080] The rear end of the second lead tab, which overlaps with the second electrode tab, can extend to the rear end 161a of the second electrode tab and can be joined to the rear end of the second electrode tab. Therefore, the strength of the second electrode tab can be enhanced, and as a result, deformation such as bending of the second electrode tab can be prevented.

[0081] The second lead tap 162 may be made of a flexible metal material. Therefore, when the electrode assembly and the upper can are coupled to each other, the second lead tap 162 may be stably bent, and as a result, the second lead tap 162 may be prevented from being broken or folded.

[0082] An insulating tape 170 for improving insulation performance is attached to the first joint part 150 and the second joint part 160 , and the insulating tape 170 is attached to surround the first joint part 150 or the second joint part 160 to prevent a short circuit from occurring.

[0083] The insulator 180 is disposed between the electrode assembly 110 and the lower can 120 or between the electrode assembly 110 and the upper can 130 , and insulates the first electrode of the electrode assembly from the second joint portion and the second electrode of the electrode assembly from the first joint portion.

[0084] Therefore, the button-type secondary battery 100 according to the first embodiment of the present invention includes a second tab portion provided with a second electrode tab and a second lead tab. Therefore, when manufacturing the secondary battery, the length of the second tab portion can be selectively extended to prevent deformation of the electrode assembly, thereby stably connecting the electrode assembly to the upper tank.

[0085] Hereinafter, in description of another embodiment of the present invention, components having the same functions as those of the above-described embodiment are given the same reference numerals in the drawings, and thus repeated description will be omitted.

[0086] [Button-type secondary battery according to a second embodiment of the present invention]

[0087] like Figure 7 As shown, a button-type secondary battery 100 according to a second embodiment of the present invention includes a second tab portion 160 provided with a second electrode tab 161 and a second lead tab 162, and the second electrode tab 161 and the second lead tab 162 are coupled to each other by welding in a state where corresponding ends of the second electrode tab 161 and the second lead tab 162 overlap with each other.

[0088] Here, the button-type secondary battery 100 according to the second embodiment of the present invention includes a protection member 190 for improving insulation performance relative to a coupling portion between the second electrode tab 161 and the second lead tab 162, and the protection member 190 is attached to surround the coupling portion of the second electrode tab 161 and the second lead tab 162.

[0089] The protection member 190 may be a silicone tape.

[0090] Therefore, the button-type secondary battery 100 according to the second embodiment of the present invention includes a protective member 190 to prevent the electrode assembly from being damaged by the coupling portion of the second electrode tab 161 and the second lead tab 162, and also prevent the coupling portion of the second electrode tab 161 and the second lead tab 162 from contacting the first electrode.

[0091] [Button-type secondary battery according to a third embodiment of the present invention]

[0092] like Figure 8 As shown, the button-type secondary battery 100 according to the third embodiment of the present invention includes a first joint portion 150 connecting the first electrode 111 of the electrode assembly 110 to the lower can 120 .

[0093] The first tab portion 150 includes a first electrode tab 151 and a first lead tab 152. Here, the first electrode tab 151 is connected to the first electrode 111, and the first lead tab 152 connects the first electrode tab 151 to the lower can 120.

[0094] Therefore, in the button-type secondary battery 100 according to the third embodiment of the present invention, the length of the first joint part 150 may be selectively extended to stably connect the electrode assembly 110 to the lower can 120 .

[0095] The length of the first electrode tab 151 is smaller than the length of the first lead tab 152. Therefore, deformation of the electrode assembly due to the self-weight of the first electrode tab 151 can be prevented.

[0096] The thickness of the first electrode tab 151 may be smaller than that of the first lead tab 152, and the width of the first electrode tab 151 may be larger than that of the first lead tab 152. This has the effect of reducing the weight of the first tab portion, thereby preventing deformation of the electrode assembly.

[0097] [Button-type secondary battery according to a fourth embodiment of the present invention]

[0098] like Figure 9 As shown, the button-type secondary battery 100 according to the fourth embodiment of the present invention includes a second tab portion 160 provided with a second electrode tab 161 and a second lead tab 162 .

[0099] Here, a lower groove 161 d is formed in an end portion of the second electrode tab 161 , and an upper groove 162 a fitted into the lower groove 161 d is formed in an end portion of the second lead tab 162 .

[0100] That is, the lower groove 161d is formed to open toward the end of the second electrode tab 161. The upper groove 162a is formed to open toward the end of the second lead tab 162. Therefore, since the second electrode tab 161 and the second lead tab 162 are coupled to each other through the lower groove 161d and the upper groove 162a, an increase in the thickness of the second electrode tab portion can be minimized.

[0101] Therefore, in the button-type secondary battery 100 according to the fourth embodiment of the present invention, the coupling force between the second electrode tab 161 and the second lead tab 162 can be increased by the coupling of the lower groove 161d and the upper groove 162a, and specifically, the thickness of the second electrode tab portion can be prevented from increasing.

[0102] Therefore, the scope of the present invention is defined by the appended claims rather than the foregoing description and the exemplary embodiments described herein. Various modifications made within the meaning of equivalents of the claims and within the claims should be considered to be within the scope of the present invention.

[0103] CROSS-REFERENCE TO RELATED APPLICATIONS

[0104] This application claims priority from Korean Patent Application No. 10-2020-0120950, filed on September 18, 2020, and Korean Patent Application No. 10-2021-0123505, filed on September 15, 2021, which are hereby incorporated by reference herein in their entirety.

Claims

1. A button-type secondary battery, comprising: electrode assembly; a lower can configured to accommodate the electrode assembly; an upper tank coupled to the opening of the lower tank; a gasket configured to insulate the lower tank and the upper tank from each other; a first joint portion configured to connect a first electrode of the electrode assembly to the lower can; as well as a second joint portion configured to connect the second electrode of the electrode assembly to the upper can, Wherein, the second connector portion includes a second electrode connector and a second lead connector, and The second electrode tab is connected to the second electrode, and the second lead tab connects the second electrode tab to the upper can, wherein the second electrode connector includes a rear end coupled to the second electrode of the electrode assembly, a front end coupled to the second lead connector, and a lead-out end disposed between the rear end and the front end and disposed on a surface of the electrode assembly corresponding to the upper can, and A length of the second electrode tab from the lead end to the front end is equal to or smaller than a width of the second electrode tab or the second lead tab.

2. The button-type secondary battery according to claim 1, wherein The length of the second electrode tab is smaller than the length of the second lead tab.

3. The button-type secondary battery according to claim 1, wherein The thickness of the second electrode tab is smaller than the thickness of the second lead tab.

4. The button-type secondary battery according to claim 1, wherein The second electrode tab and the second lead tab are coupled to each other by welding in a state in which end portions of the second electrode tab and the second lead tab, which correspond to each other, are disposed to partially overlap each other.

5. The button-type secondary battery according to claim 4, wherein A length of an overlapping portion of the second electrode tab and the second lead tab is 1.5 mm to 10.0 mm.

6. The button-type secondary battery according to claim 4, wherein A protection member having insulation properties is attached to a coupling portion of the second electrode tab and the second lead tab.

7. The button-type secondary battery according to claim 1, wherein The second electrode tab and the second lead tab are made of different materials from each other.

8. The button-type secondary battery according to claim 7, wherein The second electrode tab is made of a metal material that is lighter than the second lead tab.

9. The button-type secondary battery according to claim 7, wherein The second lead connector is made of a flexible metal material.

10. The button-type secondary battery according to claim 1, wherein The first connector portion includes a first electrode connector and a first lead connector, and The first electrode tab is connected to the first electrode, and the first lead tab connects the first electrode tab to the lower can.

11. The button-type secondary battery according to claim 10, wherein The length of the first electrode tab is shorter than the length of the first lead tab.

12. The button-type secondary battery according to claim 11, wherein A lower groove is formed in an end portion of the second electrode tab, and an upper groove fitted into the lower groove is formed in an end portion of the second lead tab.

13. The button-type secondary battery according to claim 12, wherein The lower groove is formed to open toward an end portion of the second electrode tab, and the upper groove is formed to open toward an end portion of the second lead tab.

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