Electrode assembly and rechargeable battery having the same

Abstract

Disclosed are an electrode assembly and a rechargeable battery having the same. The electrode assembly includes: a main body including a first electrode and a second electrode stacked and wound with a separator therebetween, and a first substrate located at an outermost portion of the main body; and a termination band attached to the main body to cover an end of the first substrate, where a circumferential length of the termination band is less than a perimeter of the main body, and the first substrate is disposed in two layers throughout an entire exposed area of the main body that is not covered by the termination band.

Description

[0001] Cross - reference to related applications

[0002] This application claims the priority and benefit of Korean Patent Application No. 10 - 2024 - 0006319, filed on January 15, 2024, with the Korean Intellectual Property Office, the entire disclosure of which is incorporated herein by reference. Technical field

[0003] Aspects of some embodiments of the present disclosure relate to rechargeable batteries. Background art

[0004] The electrode assemblies of cylindrical rechargeable batteries are becoming increasingly high - capacity and more dense, and generally, the higher the capacity of a rechargeable battery, the greater the change in volume of the electrode assembly during charging and discharging. The electrode assembly may include a termination tape covering the end of the negative electrode substrate. The termination tape may cover a part of the electrode assembly and allow a part of the negative electrode substrate to contact the can to prevent voltage drop (IR drop).

[0005] During the charging and discharging processes of the rechargeable battery, the volume of the part of the negative electrode substrate in the electrode assembly that is not covered by the termination tape may change. Shrinkage of the negative electrode substrate may occur, exposing the negative electrode composite layer inside the negative electrode substrate. The exposure of the negative electrode composite layer may cause the negative electrode substrate to peel off, which may lead to a short circuit in the rechargeable battery.

[0006] The above information disclosed in this background art section is only for enhancing the understanding of the background art, and thus the information discussed in this background art section does not necessarily constitute prior art. Summary of the invention

[0007] Aspects of some embodiments of the present disclosure relate to rechargeable batteries, and for example, to the electrode assemblies of cylindrical rechargeable batteries.

[0008] Aspects of some embodiments of the present disclosure include an electrode assembly capable of preventing or reducing short - circuit conditions in a rechargeable battery by preventing the exposure of the negative electrode composite layer even when the negative electrode substrate shrinks, and a rechargeable battery including the electrode assembly.

[0009] According to some embodiments, the electrode assembly includes a body and a termination tape. According to some embodiments, the body includes a first electrode and a second electrode stacked and wound with a separator therebetween, and a first substrate is located at the outermost part of the body. According to some embodiments, the termination tape is attached to the body to cover the end of the first substrate. According to some embodiments, the circumferential length of the termination tape is less than the circumference of the body. According to some embodiments, the first substrate is arranged in two layers over the entire exposed area of the body not covered by the termination tape.

[0010] According to some embodiments, the outermost portion of the body may include a first portion of the first substrate disposed in one layer and a second portion of the first substrate disposed in two layers. According to some embodiments, the termination tape may overlap with the entire first portion and a part of the second portion. According to some embodiments, the circumferential length of the termination tape may be in the range of 0.2 times to 0.8 times the circumference of the body.

[0011] According to some embodiments, the outermost portion of the body may include a third portion of the first substrate disposed in two layers and a fourth portion of the first substrate disposed in three layers. According to some embodiments, the termination tape may overlap with a part of the third portion and the entire fourth portion. According to some embodiments, the circumferential length of the termination tape may be 0.2 times to 0.5 times the circumference of the body.

[0012] According to some embodiments, two layers of the first substrate may be in contact with each other in the exposed area of the body, and the first composite layer may be located on the inner surface of the first substrate disposed on the inner side of the two layers of the first substrate.

[0013] According to some embodiments, the electrode assembly includes a body and a termination tape. According to some embodiments, the body includes a first electrode and a second electrode stacked and wound with a separator therebetween, and a part of the first electrode and an extended portion of the first electrode are located at the outermost portion of the body. According to some embodiments, the termination tape is attached to the body to cover the end of the extended portion. According to some embodiments, the extended portion includes a first extended portion made of the first substrate and the inner composite layer and a second extended portion made of the first substrate. According to some embodiments, the termination tape covers the part of the first electrode and the first extended portion at the outermost portion of the body and exposes the second extended portion.

[0014] According to some embodiments, the circumferential length of the second extended portion may be less than the circumference of the body, and the first substrate may be disposed in two layers in the second extended portion. According to some embodiments, two layers of the first substrate may be in contact with each other in the second extended portion, and the inner composite layer may be located on the first substrate disposed on the inner side of the two layers of the first substrate. According to some embodiments, the circumferential length of the termination tape may be in the range of 0.2 times to 0.8 times the circumference of the body.

[0015] According to some embodiments, the electrode assembly includes a body and a termination tape. According to some embodiments, the body includes a first electrode and a second electrode stacked and wound with a separator therebetween, and two or more layers of the first substrate are located at the outermost portion. According to some embodiments, the termination tape is attached to the body to cover the end of the first substrate. According to some embodiments, the circumferential length of the termination tape is less than the circumference of the body.

[0016] According to some embodiments, the outermost portion of the body may include a third portion of the first substrate disposed in two layers and a fourth portion of the first substrate disposed in three layers. According to some embodiments, the termination tape may cover the entire fourth portion and a part of the third portion. According to some embodiments, the circumferential length of the termination tape may be 0.2 times to 0.5 times the circumference of the body.

[0017] According to some embodiments, a rechargeable battery includes an electrode assembly, a can that houses the electrode assembly therein, and a lid assembly coupled to an end of the can to seal the can. The electrode assembly includes a body and a termination tape. According to some embodiments, the body includes a first electrode and a second electrode that are stacked and wound with a separator therebetween, and a first substrate is located at the outermost portion. According to some embodiments, the termination tape is attached to the body to cover an end of the first substrate. According to some embodiments, the circumferential length of the termination tape is less than the circumference of the body. According to some embodiments, an exposed area of the body that is not covered by the termination tape contacts the can, and the first substrate is disposed in two layers throughout the exposed area.

[0018] According to some embodiments, even if the first substrate shrinks during the charging and discharging processes of the rechargeable battery, only the first substrate located on the inner side may be exposed, and the first composite layer may not be exposed. Accordingly, it may be possible to prevent or reduce the situation in which the first composite layer is exposed during the charging and discharging processes of the rechargeable battery. As a result, the safety and driving stability of the rechargeable battery may be relatively improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 is a perspective view of an electrode assembly according to some embodiments.

[0020] Figure 2 is Figure 1 an enlarged view of region A shown in

[0021] Figure 3 is Figure 1 a cross-sectional view of the electrode assembly shown in

[0022] Figure 4 is a cross-sectional view of an electrode assembly according to some embodiments.

[0023] Figure 5 is a perspective view of a rechargeable battery according to some embodiments.

[0024] Figure 6 is Figure 5 a cross-sectional view of the rechargeable battery shown in

[0025] Figure 7 is Figure 6 a partial enlarged view of DETAILED DESCRIPTION

[0026] In the following, aspects of some embodiments of the present disclosure will be described more fully with reference to the accompanying drawings, which show aspects of some embodiments according to the present disclosure. As those skilled in the art will recognize, the described embodiments can be modified in various different ways without departing from the spirit or scope of the embodiments according to the present invention.

[0027] Figure 1 is a perspective view of an electrode assembly according to some embodiments, and Figure 2 is Figure 1 an enlarged view of region A shown in

[0028] Referring to Figure 1 and Figure 2 , according to some embodiments, the electrode assembly 100 may be a wound electrode assembly for a cylindrical rechargeable battery. The electrode assembly 100 may include a main body 110 and a termination tape 120 attached to the outermost portion of the main body 110. The main body 110 includes a first electrode 10 and a second electrode 20 wound into a circle with a separator 30 therebetween.

[0029] The main body 110 may include the first electrode 10, the second electrode 20, and the separator 30. The separator 30 may be located between the first electrode 10 and the second electrode 20 to insulate them. Each of the first electrode 10, the second electrode 20, and the separator 30 may be configured in a long strip shape and may be wound into the form of a pole core.

[0030] For example, the separator 30, the second electrode 20, the separator 30, and the first electrode 10 may be sequentially stacked to form a laminate 40, and the laminate 40 may be wound around a center pin 130. At this time, the second electrode 20 may be disposed closer to the center pin 130 than the first electrode 10.

[0031] The first electrode 10 may include a first substrate 11 and a first composite layer 12 located on the first substrate 11. The first electrode 10 may include a first lead tab 15 extending from the first substrate 11 to one side (lower side). The second electrode 20 may include a second substrate 21 and a second composite layer 22 located on the second substrate 21. The second electrode 20 may include a second lead tab 25 extending from the second substrate 21 to one side (upper side).

[0032] In a lithium-ion battery, the first substrate 11 may include, for example, a copper foil or a nickel foil, and the first composite layer 12 may include, for example, graphite, a conductive material, or a binder. The second substrate 21 may be composed of an aluminum foil, and the second composite layer 22 may include transition metal oxides such as LiCoO2, LiNiO2, LiMn2O4, Li(NiCoAl)O2, LiFePO4, and Li(NiCoMn)O2, a conductive material, and a binder. The first electrode 10 may be referred to as the negative electrode, and the second electrode 20 may be referred to as the positive electrode.

[0033] The separator 30 may include a polymer material such as polyethylene or polypropylene, and it insulates the first electrode 10 and the second electrode 20 while allowing the movement of lithium ions. The electrode assembly 100 is accommodated inside the can together with the electrolyte solution.

[0034] During charging and discharging of the rechargeable battery, the volume of the first electrode 10 changes. For example, the active material (graphite) of the first composite layer 12 reversibly absorbs and releases lithium ions from the active material (lithium oxide) of the second composite layer 22, and allows current to flow through the external circuit. During charging and discharging of the rechargeable battery, the volume of the first composite layer 12 changes as lithium ions enter and leave, and the first substrate 11 that supports the first composite layer 12 repeatedly contracts and expands.

[0035] In the main body 110, according to the winding direction, the lengths of the first electrode 10 and the second electrode 20 may be different from each other, and the length of the first composite layer 12 located on the inner surface of the first substrate 11 and the length of the first composite layer 12 located on the outer surface of the first substrate 11 may be different from each other. At this time, the inner surface of the first substrate 11 is the surface facing the center pin 130, and the outer surface of the first substrate 11 is the surface disposed toward the outside of the main body 110. Hereinafter, "length" refers to the circumferential length measured along the winding direction from the center pin 130.

[0036] Figure 3 is Figure 1 a cross-sectional view of the electrode assembly shown in. In Figure 3 it, for convenience, the separator 30 is omitted, and for easier understanding, it is assumed that the first electrode 10, the second electrode 20, and the termination tape 120 are disposed at a certain distance from each other.

[0037] Refer to Figures 1 to 3, in the main body 110, the second electrode 20 can be disposed closer to the center pin 130 than the first electrode 10. That is, the first electrode 10 can be wound together with the second electrode 20 outside the second electrode 20. The length of the first electrode 10 can be greater than the length of the second electrode 20, and the first electrode 10 can include an extension portion 50 that does not overlap with the second electrode 20 and is disposed separately. The length of the extension portion 50 can be less than the circumference of the main body 110.

[0038] In Figure 3 , P1 represents the end position of the second electrode 20, and P2 represents the end position of the first electrode 10. The extension portion 50 of the first electrode 10 represents the portion of the first electrode 10 from P1 to P2. The extension portion 50 does not overlap with the second electrode 20, but overlaps with the portion of the first electrode 10 located inside the extension portion 50.

[0039] The end of the second electrode 20 can be the end of the second substrate 21, and the second composite layer 22 located on two surfaces of the second substrate 21 can be disposed at a certain distance (e.g., a set or predetermined distance) from the end of the second substrate 21. The end 10A of the first electrode 10 can be the end of the first substrate 11, and the first composite layer 12 located on two surfaces of the first substrate 11 can be disposed at a certain distance (e.g., a set or predetermined distance) from the end 10A of the first substrate 11.

[0040] For convenience, the first composite layer 12 located on the inner surface of the first substrate 11 is referred to as "inner composite layer 12A", and the first composite layer 12 located on the outer surface of the first substrate 11 is referred to as "outer composite layer 12B".

[0041] The length of the inner composite layer 12A can be greater than the length of the outer composite layer 12B. In Figure 3 , P3 represents the end position of the outer composite layer 12B.

[0042] The end of the outer composite layer 12B can be disposed slightly outward along the winding direction than the end (P1 position) of the second substrate 21, and the inner composite layer 12A can be provided to be one turn longer than the outer composite layer 12B. That is, the inner composite layer 12A can be disposed by further extending one turn from the end of the outer composite layer 12B. The end position of the inner composite layer 12A can be the same as P3.

[0043] The inner composite layer 12A may be located in a part of the extension portion 50, and the remaining part of the extension portion 50 may be constituted by the first substrate 11. Among the extension portion 50 from P1 to P2, the inner composite layer 12A may be located in some of the sections from P1 to P3, and most of the section from P3 to P2 among the extension portion 50 may be constituted by the first substrate 11. The length of the inner composite layer 12A located in the extension portion 50 (the length from P1 to P3) may be 0.1 times (or approximately 0.1 times) or less of the total length of the extension portion 50.

[0044] The extension portion 50 may be divided into a first extension portion 51 where the inner composite layer 12A is disposed and a second extension portion 52 constituted by the first substrate 11 without the inner composite layer 12A. In other words, the extension portion 50 may include a first extension portion 51 made of the first substrate 11 and the inner composite layer 12A and a second extension portion 52 made of the first substrate 11. The first extension portion 51 is the section from P1 to P3, and the second extension portion 52 is the section from P3 to P2. The first substrate 11 constituting the second extension portion 52 may overlap with the first substrate 11 located inside it.

[0045] The outermost part of the main body 110 may be constituted by a first part where the first substrate 11 is disposed as one layer and a second part where the first substrate 11 is disposed as two layers. The second part may correspond to the second extension portion 52, and the first part may correspond to the remaining part excluding the second extension portion 52. In the second part, the first substrate 11 may be disposed as two layers. The two layers of the first substrate 11 may be in direct contact without any material layer therebetween. The inner composite layer 12A may be on the inner surface of the first substrate 11 on the inner side of the two layers of the first substrate 11.

[0046] The termination tape 120 may cover the end 10A of the first substrate 11 and be attached to the outermost part of the main body 110. At this time, the end 10A of the first substrate 11 has the same meaning as the end of the first electrode 10, the end of the extension portion 50, and the end of the second extension portion 52.

[0047] The termination tape 120 may be made of a polymer film having an adhesive function, and it fixes the end 10A of the first substrate 11 so that the end 10A of the first substrate 11 does not move. The termination tape 120 may be made of a polyimide (PI) film or a polyethylene terephthalate (PET) film, but is not limited to this example.

[0048] The termination tape 120 is along the axial direction of the main body 110 ( Figure 1The height in the vertical direction) may be equal to or less than the height of the main body 110. The termination strip 120 may be provided as a single piece, or may be provided as multiple pieces spaced apart from each other along the axial direction of the main body 110. In Figure 1 , the case where one termination strip 120 is provided is shown as an example.

[0049] Referring to Figure 3 , the termination strip 120 can be attached to the end 10A of the first substrate 11 while minimizing the overlapping portion with the extension portion 50. That is, the termination strip 120 can be located opposite the extension portion 50 such that most of the extension portion 50 is exposed. The circumferential length of the termination strip 120 can be less than the circumference of the main body 110, and the exposed area of the main body 110 not covered by the termination strip 120 can correspond to the second extension portion 52.

[0050] The termination strip 120 can overlap with both ends of the second extension portion 52 and be located opposite the second extension portion 52. That is, the termination strip 120 can overlap with the entire first part where the first substrate 11 is arranged in one layer and a part of the second part where the first substrate 11 is arranged in two layers.

[0051] In Figure 3 , P4 and P5 represent the positions of the two ends of the termination strip 120. The termination strip 120 can overlap with one end of the second extension portion 52 and a part of the second extension portion 52 in the section from P4 to P2, and can overlap with the first substrate 11 on which the inner composite layer 12A is arranged in the section from P2 to P3. Additionally, in the section from P3 to P5, the termination strip 120 can overlap with the opposite end of the second extension portion 52 and a part of the second extension portion 52. A part of the first electrode 10 and the extension portion 50 of the first electrode 10 can be located at the outermost part. The termination strip 120 can cover this part of the first electrode 10 and the first extension portion 51 at the outermost part of the main body 110 and expose the second extension portion 52.

[0052] The termination strip 120 can expose a part of the first substrate 11 and allow the exposed first substrate 11 to contact the can to prevent voltage drop (IR drop). The can contacts the first substrate 11 and is charged to the same polarity as the first electrode 10, and it can act as the external terminal (negative terminal) of the first electrode 10. The exposed area of the main body 110 not covered by the termination strip 120 at the outermost part of the main body 110 can be the second extension portion 52, and the first substrate 11 can be arranged in two layers in the exposed area of the main body 110.

[0053] During the charging and discharging processes of the rechargeable battery, volume changes occur in the main body 110. In the region covered by the termination band 120, the volume change is suppressed by the termination band 120, but volume changes occur in the exposed region not covered by the termination band 120. According to some embodiments, since the first substrate 11 is arranged in two layers in the exposed region of the main body 110, even if the outer first substrate 11 shrinks, only the first substrate 11 located inside it is exposed, and the first composite layer 12 is not exposed.

[0054] The circumferential length of the termination band 120 that can be attached during the manufacturing process of the electrode assembly 100 can be 0.2 times (or approximately 0.2 times) the circumference of the main body 110. Additionally, if the circumferential length of the termination band 120 exceeds 0.8 times (or approximately 0.8 times) the circumference of the main body 110, the contact area between the first substrate 11 and the can becomes smaller, which may cause a voltage drop. Accordingly, the circumferential length of the termination band 120 measured at the outermost part of the main body 110 can be 0.2 times to 0.8 times (or approximately 0.2 times to 0.8 times) the circumference of the main body 110.

[0055] The second extension part 52 can have a length slightly greater than the circumference of the main body 110 minus the circumferential length of the termination band 120 to occupy the exposed region of the main body 110. That is, the length of the second extension part 52 can correspond to the length of the two ends overlapping with the termination band 120 plus the length of the exposed region of the main body 110 in contact with the inner wall of the can.

[0056] In this way, the electrode assembly 100 according to some embodiments can prevent voltage drop by bringing the exposed region of the main body 110 into contact with the can, and at the same time prevent the phenomenon of exposing the first composite layer 12 even if the first substrate 11 shrinks during the charging and discharging processes. Therefore, the electrode assembly 100 according to some embodiments can relatively improve the safety and driving stability of the rechargeable battery.

[0057] Figure 4 is a cross-sectional view of an electrode assembly according to some embodiments. Except for the configuration of the second extension part 52 and the termination band 120 described below, regarding Figure 4 the electrode assembly 100 of the illustrated and described embodiments has the same or similar configuration as the above-described embodiments.

[0058] Refer to Figure 4 , according to some embodiments, the length of the second extension part 52 can be greater than the circumference of the main body 110. That is, the second extension part 52 can be provided with a length of one turn or more, and the second extension part 52 itself can include a double overlapping portion. In Figure 4Among them, P6 represents the starting position of the second extended portion 52, and P7 represents the ending position of the second extended portion 52. The second extended portion 52 can extend from P6 for more than one turn, and in the section from P6 to P7, the second extended portion 52 can be arranged in two layers.

[0059] Since the second extended portion 52 is provided with a length of more than one turn, the first substrate 11 can be arranged in two or more layers at the outermost part of the main body 110 regardless of its position. For example, in the section from P6 to P7, the first substrate 11 can be arranged in three layers, and in the remaining section, the first substrate 11 can be arranged in two layers.

[0060] The termination tape 120 can be attached to the main body 110 to cover the end 10A of the second extended portion 52, and it can cover the portion where the second extended portion 52 overlaps in two layers (the portion from P6 to P7). In Figure 4 Among them, P8 and P9 represent the positions of the two ends of the termination tape 120. The termination tape 120 can overlap with two layers of the first substrate 11 in the section from P8 to P6 and the section from P7 to P9, and it can overlap with three layers of the first substrate 11 in the section from P6 to P7.

[0061] That is to say, the outermost part of the main body 110 can be composed of a third part where the first substrate 11 is arranged in two layers and a fourth part where the first substrate 11 is arranged in three layers. The termination tape 120 can overlap with a part of the third part and the whole fourth part.

[0062] The circumferential length of the termination tape 120 can be 0.2 times to 0.5 times the circumference of the main body 110. Since the first substrate 11 is arranged in two or more layers in the outermost part of the entire main body 110, the circumferential length of the termination tape 120 can be less than half of the circumference of the main body 110. In this case, the contact area between the first substrate 11 and the inner wall of the can increases, thereby improving the effect of suppressing voltage drop.

[0063] Even if the first substrate 11 in the exposed area shrinks during the charging and discharging process of the rechargeable battery, only the first substrate 11 located inside it is exposed, and the first composite layer 12 is not exposed. The electrode assembly according to some embodiments can also relatively improve the safety and driving stability of the rechargeable battery by preventing the first composite layer 12 from being exposed during the charging and discharging process of the rechargeable battery.

[0064] Figure 5 is a perspective view of a rechargeable battery according to some embodiments, Figure 6 is Figure 5 a cross-sectional view of the rechargeable battery shown in Figure 7 isFigure 6 Partial enlarged view.

[0065] Referring to Figures 5 to 7 , according to some embodiments, the rechargeable battery 500 may include a can 200, an electrode assembly 100 accommodated inside the can 200, and a cap assembly 300 coupled to an end of the can 200 to seal the can 200. The electrode assembly 100 may be an electrode assembly according to one of the above-described embodiments and may include a body 110 and a termination tape 120.

[0066] The can 200 may include a circular bottom 210 and a cylindrical side 220 connected to an edge of the bottom 210. When the rechargeable battery 500 is turned upside down, the bottom 210 may be referred to as the top. During the manufacturing process of the rechargeable battery 500, an end (upper end) of the side 220 is open, and the electrode assembly 100 may be accommodated inside the can 200 together with an electrolyte solution. The can 200 may be made of steel, a steel alloy, aluminum, and an aluminum alloy.

[0067] A flange portion 230 and a curled portion 240 may be located in the side 220 of the can 200. The flange portion 230 is a portion of the side 220 where a part of the side 220 is deformed to be recessed toward the inside of the can 200. The curled portion 240 is a portion of the side 220 where an edge of the side 220 is bent inward. Movement of the electrode assembly 100 may be inhibited by the flange portion 230, and the cap assembly 300 may be fixed to the can 200 by the flange portion 230 and the curled portion 240.

[0068] In the electrode assembly 100, a first lead tab 15 and a second lead tab 25 may be located on opposite sides of each other. The first lead tab 15 may be located on a side (lower side) of the electrode assembly 100 facing the bottom 210 and may be fixed to the bottom 210. The second lead tab 25 may be located on a side (upper side) of the electrode assembly 100 facing the cap assembly 300 and may be fixed to the cap assembly 300.

[0069] A first insulating plate 410 may be located between the electrode assembly 100 and the bottom 210 of the can 200. A second insulating plate 420 may be located between the electrode assembly 100 and the cap assembly 300. The first insulating plate 410 may prevent the second electrode 20 of the electrode assembly 100 from contacting the can 200. The second insulating plate 420 may prevent the first electrode 10 of the electrode assembly 100 from contacting the cap assembly 300.

[0070] The lid assembly 300 may include a safety vent hole 310, a lower lid 320 located on the side (lower side) of the safety vent hole 310 facing the electrode assembly 100, an annular insulating portion 330 located between the safety vent hole 310 and the lower lid 320, and an upper lid 340 located on the side (upper side) of the safety vent hole 310 opposite to the lower lid 320. The configuration of the lid assembly 300 is not limited to the illustrated example and may be modified in various ways.

[0071] The safety vent hole 310 may include a central portion 311 and a peripheral portion 312 surrounding the central portion 311. The thickness of the central portion 311 may be greater than the thickness of the peripheral portion 312, and a cutout groove 313 may be located in the peripheral portion 312. The lower lid 320 may include a central portion 321 and a peripheral portion 322 surrounding the central portion 321, and the thickness of the central portion 321 may be less than the thickness of the peripheral portion 322. At least one hole may be located in each of the central portion 321 and the peripheral portion 322.

[0072] The central portion 311 of the safety vent hole 310 and the central portion 321 of the lower lid 320 may be integrally connected by a method such as welding. The safety vent hole 310 and the lower lid 320 may be disposed at a certain distance from each other in the remaining portions other than the central portions 311 and 321. The insulating portion 330 may surround the central portions 311 and 321, and it may be located between the safety vent hole 310 and the lower lid 320. The upper lid 340 may include a terminal portion 341, and at least one hole for discharging gas may be located in the upper lid 340.

[0073] The lid assembly 300 may be coupled to the side portion 220 of the can 200 via an insulating gasket 430. The insulating gasket 430 surrounds the edge of the safety vent hole 310 and the upper lid 340, and it may be squeezed between the flange portion 230 and the curled portion 240 of the can 200. The second lead tab 25 of the electrode assembly 100 may be fixed to one surface (lower surface) of the lower lid 320. The lower lid 320, the safety vent hole 310, and the upper lid 340 may be charged to have the same polarity as the second electrode 20. The terminal portion 341 of the upper lid 340 may function as a terminal (positive terminal) that allows current to flow to an external device.

[0074] The can 200 to which the first lead tab 15 is fixed may be charged to have the same polarity as the first electrode 10, and the bottom portion 210 of the can 200 may function as a terminal (negative terminal) that allows current to flow to an external device. Refer to Figure 1 and Figure 6 , the exposed area of the main body 110 not covered by the termination tape 120 contacts the side portion 220 to expand the contact area between the can 200 and the first electrode 10.

[0075] During the charging and discharging processes of the rechargeable battery 500, repetitive volume changes occur in the electrode assembly 100, and contraction and expansion of the first substrate 11 may occur in the exposed area of the main body 110 that is not covered by the termination tape 120. In the rechargeable battery 500 according to some embodiments, by disposing the first substrate 11 in two layers in the entire exposed area of the main body 110, even if the outermost first substrate 11 contracts, the first composite layer 12 can be prevented from being exposed, thereby relatively improving safety and driving stability.

[0076] Meanwhile, during the use of the rechargeable battery 500, gas may be generated for various reasons, and the internal pressure of the rechargeable battery 500 may increase due to the gas. When gas is generated, the pressure is continuously applied to the safety vent hole 310 through the hole in the lower cover 320, and at a specific pressure, the safety vent hole 310 may deform toward the outside (upper side) of the cover assembly 300, causing the safety vent hole 310 and the lower cover 320 to separate from each other.

[0077] At this time, the central portion 321 of the lower cover 320 may be detached from the peripheral portion 322 and rise together with the central portion 311 while being attached to the central portion 311 of the safety vent hole 310. The flow of current is blocked by the separation of the safety vent hole 310 and the lower cover 320. Thereafter, when the pressure continues to rise, the safety vent hole 310 ruptures around the cutout groove 313, and the internal gas is discharged through the hole in the upper cover 340. Through this process, ignition and explosion of the rechargeable battery 500 can be prevented.

[0078] Although aspects of some embodiments of the present disclosure have been described in connection with currently considered to be practical embodiments, it should be understood that the present disclosure is not limited to the disclosed embodiments, but on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the claims and their equivalents.

Claims

1. An electrode assembly, comprising: A body, including a first electrode and a second electrode that are stacked and wound with a separator therebetween, and a first substrate is located at the outermost part of the body; And A termination tape, attached to the body to cover the end of the first substrate, Wherein, the circumferential length of the termination tape is less than the circumference of the body, And the first substrate is arranged in two layers over the entire exposed area of the body not covered by the termination tape.

2. The electrode assembly according to claim 1, wherein, The outermost part of the body includes a first part where the first substrate is arranged in one layer and a second part where the first substrate is arranged in two layers, And the termination tape overlaps with the entire first part and a part of the second part.

3. The electrode assembly according to claim 2, wherein, The circumferential length of the termination tape is in the range of 0.2 times to 0.8 times the circumference of the body.

4. The electrode assembly according to claim 1, wherein, The outermost part of the body includes a third part where the first substrate is arranged in two layers and a fourth part where the first substrate is arranged in three layers, And the termination tape covers a part of the third part and the entire fourth part.

5. The electrode assembly according to claim 4, wherein, The circumferential length of the termination tape is in the range of 0.2 times to 0.5 times the circumference of the body.

6. The electrode assembly according to claim 1, wherein, The two layers of the first substrate are in contact with each other in the exposed area of the body, and a first composite layer is on the inner surface of the first substrate located inside the two layers of the first substrate.

7. An electrode assembly, comprising: A body, including a first electrode and a second electrode that are stacked and wound with a separator therebetween, and a part of the first electrode and an extended part of the first electrode are located at the outermost part of the body; And A termination tape, attached to the body to cover the end of the extended part, Wherein, the extended part includes a first extended part made of a first substrate and an inner composite layer and a second extended part made of the first substrate, and The termination tape covers the part of the first electrode and the first extended part at the outermost part of the body and exposes the second extended part.

8. The electrode assembly according to claim 7, wherein, The circumferential length of the second extended part is less than the circumference of the body, And the first substrate is arranged in two layers in the second extended part.

9. The electrode assembly according to claim 8, wherein, The two layers of the first substrate are in contact with each other in the second extended part, An inner composite layer is on the first substrate located inside the two layers of the first substrate.

10. The electrode assembly according to claim 8, wherein, The circumferential length of the termination tape is in the range of 0.2 times to 0.8 times the circumference of the body.

11. An electrode assembly, comprising: A main body, including a first electrode and a second electrode that are stacked and wound with a separator therebetween, and two or more layers of a first substrate are located at the outermost portion of the main body; and A termination tape, attached to the main body to cover the end of the first substrate, wherein the circumferential length of the termination tape is less than the circumference of the main body.

12. The electrode assembly according to claim 11, wherein, the outermost portion of the main body includes a third portion where the first substrate is arranged in two layers and a fourth portion where the first substrate is arranged in three layers, and the termination tape covers the entire fourth portion and a part of the third portion.

13. The electrode assembly according to claim 12, wherein, the circumferential length of the termination tape is in the range of 0.2 times to 0.5 times the circumference of the main body.

14. A rechargeable battery, comprising: An electrode assembly; A can, in which the electrode assembly is accommodated; and A lid assembly, coupled to the end of the can to seal the can, wherein the electrode assembly includes: A main body, including a first electrode and a second electrode that are stacked and wound with a separator therebetween, and a first substrate is located at the outermost portion of the main body; and A termination tape, attached to the main body to cover the end of the first substrate, wherein the circumferential length of the termination tape is less than the circumference of the main body, the exposed area of the main body not covered by the termination tape contacts the can, and the first substrate is arranged in two layers throughout the exposed area.

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