Electrode, electrode assembly, and secondary battery comprising same

Abstract

The present disclosure provides an electrode, an electrode assembly, and a secondary battery comprising same. The electrode includes a metal substrate, an uncoated portion formed at an end of the metal substrate, and a mixture portion formed on a portion of the metal substrate. The uncoated portion includes first cut portions and second cut portions repeatedly formed in a first direction parallel to the direction in which the metal substrate is wound. The first cut portions and the second cut portions extend along a second direction perpendicular to the first direction. The cutting length of the second cut portions is larger than that of the first cut portions. The first cut portions may be disposed between the second cut portions.

Description

Electrode, electrode assembly, and secondary battery including the same

[0001] The present disclosure relates to an electrode, an electrode assembly, and a secondary battery comprising the same.

[0002]

[0003] Unlike primary batteries, which cannot be recharged, secondary batteries are batteries capable of both charging and discharging. Low-capacity secondary batteries are used in small portable electronic devices such as smartphones, feature phones, laptop computers, digital cameras, and camcorders, while high-capacity secondary batteries are widely used as power sources for motor drive systems and power storage batteries in hybrid and electric vehicles. Such secondary batteries include an electrode assembly consisting of a positive electrode and a negative electrode, a case housing the assembly, and electrode terminals connected to the electrode assembly.

[0004] Although rechargeable batteries are used in various environments due to their excellent electrical characteristics, conventional small batteries have had limitations in terms of designable energy density. Since the amount of electrical energy that can be stored is limited relative to the size and weight of the battery, there is a gradually increasing demand for large batteries with higher energy density in applications such as electric vehicles.

[0005] Meanwhile, conventional cylindrical secondary batteries have a structure in which the positive electrode is placed on one side of the case and the negative electrode on the opposite side. In this case, components for the electrical connection between the positive and negative electrodes must be placed at both ends along the height of the case, and since the internal space of the case is not utilized to the fullest extent, there was a problem of low energy density. Additionally, because the positive and negative electrodes are separated on opposite sides, the current path becomes longer, increasing internal resistance and causing a decrease in output.

[0006] The information described above disclosed in the background technology of this invention is intended only to enhance understanding of the background of the present invention and may therefore include information that does not constitute prior art.

[0007]

[0008] The present disclosure provides an electrode, an electrode assembly, and a secondary battery including the same for solving the above-mentioned problems.

[0009] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems can be clearly understood by those skilled in the art from the description of the invention below.

[0010]

[0011] An electrode according to one embodiment of the present invention for solving the above technical problem comprises a metal substrate, a blank portion formed at the end of the metal substrate, and a composite portion formed on a part of the metal substrate. The blank portion comprises a first cutting portion and a second cutting portion formed repeatedly in a first direction parallel to the winding direction of the metal substrate, and the first cutting portion and the second cutting portion extend along a second direction perpendicular to the first direction, the cutting length of the second cutting portion is longer than that of the first cutting portion, and the first cutting portion may be disposed between the second cutting portions.

[0012] According to one embodiment of the present invention, the second cutting portion may be repeatedly arranged along the first direction for every one or two first cutting portions.

[0013] According to one embodiment of the present invention, the second cutting section may be repeatedly arranged every three or four first cutting sections along the first direction.

[0014] According to one embodiment of the present invention, the second cutting portion may be formed to be 0.5 mm to 5 mm longer than the first cutting portion.

[0015] According to one embodiment of the present invention, the unwound portion may be folded while the substrate is wound to form a plurality of tabs, and may be folded at the end of a first cutting portion adjacent to a composite portion.

[0016] An electrode assembly according to an embodiment of the present invention for solving a technical problem comprises: a first electrode including a first composite portion coated with an active material and a first uncoated portion; a second electrode including a second composite portion coated with an active material and a second uncoated portion; and a separator interposed between the first electrode and the second electrode. The first electrode, the second electrode, and the separator are wound around a winding axis. The first uncoated portion includes a first cutting portion and a second cutting portion formed repeatedly in a first direction parallel to the winding direction of the first electrode. The first cutting portion and the second cutting portion extend along a second direction perpendicular to the first direction, and the cutting length of the second cutting portion is longer than that of the first cutting portion. The first cutting portion is disposed between the second cutting portions. The second uncoated portion includes a third cutting portion and a fourth cutting portion formed repeatedly in a first direction parallel to the winding direction of the second electrode. The third cutting portion and the fourth cutting portion extend along a second direction perpendicular to the first direction. The cutting length of the fourth cutting portion is longer than that of the third cutting portion. A third cutting section may be placed in between.

[0017] According to one embodiment of the present invention, the second cutting section may be repeatedly arranged for every one or two first cutting sections along the first direction, and the fourth cutting section may be repeatedly arranged for every one or two third cutting sections along the first direction.

[0018] According to one embodiment of the present invention, the second cutting section may be repeatedly arranged every three or four first cutting sections along the first direction, and the fourth cutting section may be repeatedly arranged every three or four third cutting sections along the first direction.

[0019] According to one embodiment of the present invention, the second cutting portion may be formed to be 0.5 mm to 5 mm longer than the first cutting portion, and the fourth cutting portion may be formed to be 0.5 mm to 5 mm longer than the third cutting portion.

[0020] A secondary battery according to an embodiment of the present invention for solving the above technical problem comprises: a first electrode including a first non-reinforcing portion; a second electrode including a second non-reinforcing portion; an electrode assembly wound with a separator; a case having one side open and a through hole formed on the other side, accommodating the electrode assembly and electrically connected to the first electrode; a vent cap plate fastened to the open side of the case; and an electrode terminal disposed through the through hole and electrically connected to the second electrode. The first non-reinforcing portion includes a first cutting portion and a second cutting portion formed repeatedly in a first direction parallel to the winding direction of the first electrode, wherein the first cutting portion and the second cutting portion extend along a second direction perpendicular to the first direction, the cutting length of the second cutting portion is longer than that of the first cutting portion, and the first cutting portion is disposed between the second cutting portions. The second non-reinforcing portion includes a third cutting portion and a fourth cutting portion formed repeatedly in a first direction parallel to the winding direction of the second electrode, wherein the third cutting portion and the fourth cutting portion extend along a second direction perpendicular to the first direction, and the cutting of the fourth cutting portion The length is longer than the third section, and the third section may be placed between the fourth sections.

[0021] According to one embodiment of the present invention, the first non-removable portion and the second non-removable portion may be spaced apart and protrude from one surface of the electrode assembly and face each other.

[0022] According to one embodiment of the present invention, the first and second unwound portions may be arranged to extend radially from the core portion of the electrode assembly toward the outermost portion.

[0023] According to one embodiment of the present invention, the first and second unwound portions may be arranged in a fan shape such that the number of them distributed in the circumferential direction increases from the core portion of the electrode assembly to the outermost portion.

[0024] According to one embodiment of the present invention, it may further include a first current collector plate coupled to one end of a case and electrically connected to a first non-electrical portion, and a second current collector plate coupled to one end of an electrode terminal and electrically connected to a second non-electrical portion.

[0025] According to one embodiment of the present invention, a first current collector plate and a second current collector plate are spaced apart and facing each other, and may further include a first gasket disposed between the first current collector plate and the second current collector plate to insulate the first current collector plate and the second current collector plate.

[0026] According to one embodiment of the present invention, the first non-circular portion may be folded while overlapping toward the winding core portion and connected to the first current collector plate, and the second non-circular portion may be folded while overlapping toward the winding core portion and connected to the second current collector plate.

[0027] According to one embodiment of the present invention, a second gasket provided in a through hole and electrically insulating the case and the electrode terminal may be further included.

[0028] According to one embodiment of the present invention, the second cutting section may be repeatedly arranged for every one or two first cutting sections along the first direction, and the fourth cutting section may be repeatedly arranged for every one or two third cutting sections along the first direction.

[0029] According to one embodiment of the present invention, a first unwound portion may be folded to form a plurality of first tabs while the electrode assembly is wound, and may be folded at the end of a separator adjacent to a first composite portion, and a second unwound portion may be folded to form a plurality of second tabs while the electrode assembly is wound, and may be folded at the end of a separator adjacent to a second composite portion.

[0030] According to one embodiment of the present invention, the second cutting section may be repeatedly arranged every three or four first cutting sections along the first direction, and the fourth cutting section may be repeatedly arranged every three or four third cutting sections along the first direction.

[0031]

[0032] According to some embodiments of the present invention, the internal space utilization of the case can be increased by arranging the negative and positive electrodes of the secondary battery in one direction. Accordingly, the energy density of the secondary battery can be improved.

[0033] According to some embodiments of the present invention, the negative and positive electrodes of a secondary battery can be arranged in one direction to reduce the current path. Accordingly, the internal resistance of the secondary battery can be lowered, thereby improving the output.

[0034] According to some embodiments of the present invention, the risk of a short circuit and the problem of bending or flapping of the substrate can be solved by arranging the negative and positive electrodes of a secondary battery in one direction so that the substrate becomes longer.

[0035] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0036]

[0037] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0038] FIG. 1 is a drawing showing an example of an electrode according to one embodiment of the present disclosure.

[0039] Figure 2 is a drawing showing an example of an electrode with a second cutting portion added in Figure 1.

[0040] Figure 3 is a drawing showing an example of an electrode with a first cutting portion added in Figure 2.

[0041] FIG. 4 is a drawing showing an example of an electrode according to another embodiment of the present disclosure.

[0042] FIG. 5 is a drawing showing an uncoordinated portion spaced apart from the composite portion in an electrode according to one embodiment of the present disclosure.

[0043] FIG. 6 is a drawing showing an example of an electrode assembly according to one embodiment of the present disclosure.

[0044] Figure 7 is a drawing showing that the second uncut portion of the electrode assembly of Figure 6 has been cut.

[0045] FIG. 8 is a drawing showing an example of an electrode assembly according to one embodiment of the present disclosure, in which a first electrode and a second electrode are arranged in an alternating manner.

[0046] FIG. 9 is a drawing showing an example of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure.

[0047] FIG. 10 is a drawing showing the upper surface of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure.

[0048] FIG. 11 is a drawing showing the lower surface of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure.

[0049] FIG. 12 is a drawing showing the first and second unbent portions of an electrode assembly according to one embodiment of the present disclosure in a bent state.

[0050] FIG. 13 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0051] FIG. 14 is an exploded perspective view showing a part of the configuration of a secondary battery according to one embodiment of the present disclosure.

[0052] FIG. 15 is a perspective view showing a partial configuration of a secondary battery according to one embodiment of the present disclosure.

[0053] Figure 16 is an enlarged view of area A of Figure 13.

[0054]

[0055] Preferred embodiments of the present invention will be described in detail below with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings. Instead, based on the principle that the inventor can appropriately define the concepts of terms to best describe their invention, they should be interpreted in a meaning and concept consistent with the technical spirit of the present invention. Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention. It should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0056] Additionally, as used herein, “comprise, include” and / or “comprising, including” specify the presence of the mentioned features, numbers, steps, actions, parts, elements, and / or groups thereof, and do not exclude the presence or addition of one or more other features, numbers, actions, parts, elements, and / or groups.

[0057] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0058] The statement that two subjects of comparison are 'identical' means that they are 'substantially identical'. Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0059] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0060] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0061] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0062] Furthermore, where it is stated that one component is "connected," "coupled," or "connected" to another component, it should be understood that while said components may be directly connected or connected to each other, another component may be "interposed" between each component, or that each component may be "connected," "coupled," or "connected" through another component. Additionally, when it is stated that a part is electrically coupled with another part, this includes not only cases where they are directly connected but also cases where they are connected with an intermediate element in between.

[0063] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise. That is, "and / or" includes any combination or any combination of the enumerated items. "C to D" means C or more and D or less, unless specifically stated otherwise.

[0064] The terms used in this specification are intended to describe embodiments of the present disclosure and are not intended to limit the present disclosure.

[0065] FIG. 1 is a drawing showing an example of an electrode according to one embodiment of the present disclosure, FIG. 2 is a drawing showing an example of an electrode with a second cutting portion added in FIG. 1, and FIG. 3 is a drawing showing an example of an electrode with a first cutting portion added in FIG. 2.

[0066] Referring to FIGS. 1 to 3, the electrode may include a metal substrate (110) and a composite portion (120). The composite portion (120) may be formed on a part of the metal substrate (110) such that a non-coated portion (130) is formed at the end of the metal substrate (110). The non-coated portion (130) may be formed at the end of the metal substrate (110). The metal substrate (110) may be formed of a metal material. On one or both sides of the metal substrate (110), a composite portion (120) coated with an active material and a non-coated portion (130) not coated with an active material may be formed. The composite portion (120) may correspond to the area on the metal substrate (110) where the active material is coated. According to one embodiment, the composite portion (120) may be formed in the central part of the metal substrate (110). The central part of the metal substrate (110) may correspond to the part excluding the end of the metal substrate (110).

[0067] In one embodiment, when the electrode is a negative electrode, the metal substrate (110) may be formed from a metal material such as copper, a copper alloy, nickel, or a nickel alloy. In this case, the composite part (120) may be formed by coating a negative active material such as graphite or carbon.

[0068] In one embodiment, when the electrode is a positive electrode, the metal substrate (110) may be formed from a metal material such as aluminum or an aluminum alloy. In this case, the composite part (120) may be formed by coating a positive active material such as a transition metal oxide.

[0069] The uncut portion (130) may include a first cut portion (131) and a second cut portion (132) formed repeatedly in a first direction (D1) parallel to the winding direction of the metal substrate (110). The first cut portion (131) and the second cut portion (132) may be formed by extending along a second direction (D2) perpendicular to the first direction (D1). The first cut portion (131) and the second cut portion (132) may be formed by extending along the second direction (D2) from the edge of the uncut portion (130) toward the composite portion (120). For example, the first cut portion (131) and the second cut portion (132) may be formed by cutting the uncut portion (130). In one embodiment, the cutting length (L2) of the second cut portion (132) may be longer than the cutting length (L1) of the first cut portion (131).

[0070] In one embodiment, the uncut portion (130) may be notched by cutting both ends along the second direction (D2) to the composite portion (120). A first cutting portion (131) may be positioned between the second cutting portion (132) of the uncut portion (130).

[0071] The electrode of the secondary battery has a structure in which a positive electrode and a negative electrode protrude in both directions, and the positive electrode and negative electrode do not overlap each other, so a short circuit can be prevented. However, in the electrode of the secondary battery according to one embodiment of the present invention, the positive electrode and the negative electrode protrude in one direction, so only one non-electrode must be left in the part where the non-electrode protrudes. Accordingly, the non-electrode (130) must be relatively longer, and the notching and cutting depth must also be increased.

[0072] For example, when the length of the second direction (D2) protruding from the composite part (120) of the uncut part (130) is relatively increased, if the notching and cutting lengths are maintained, a short circuit may occur due to the uncut part (130) remaining at both ends of the composite part (120). Also, when the length of the uncut part (130) is relatively increased, if the cutting length is maintained and only the notching is deep, there are many uncut and connected uncut parts (130), so when the electrode moves along the roller, the metal substrate (110) may bend. Also, when the length of the uncut part (130) is relatively increased, if the notching and cutting are extended, each cut uncut part (130) may have a thin thickness and long length, causing it to flutter. This may lead to a winding defect in the electrode assembly and cause a decrease in productivity.

[0073] According to one embodiment of the present invention, a secondary battery having a unidirectional electrode structure for preventing the above-described phenomenon may be provided.

[0074] The unseen portion (130) may protrude to one side of the composite portion (120) in the second direction (D2). In one embodiment, the second cutting portion (132) may be arranged repeatedly along the first direction (D1) for every one or two first cutting portions (131). The second cutting portion (132) may be formed to be 0.5 mm to 5 mm longer than the first cutting portion (131).

[0075] For example, FIG. 1 illustrates that the bare portion (130) is cut 5 times in the second direction (D2) to form 5 cut sections, and 6 bare portion sections are arranged along the first direction (D1) of the composite portion (120). FIG. 2 illustrates that the bare portion (130) is cut 6 times in the second direction (D2) to form 6 cut sections, and 7 bare portion sections are arranged along the first direction (D1) of the composite portion (120). FIG. 3 illustrates that the bare portion (130) is cut 7 times in the second direction (D2) to form 7 cut sections, and 8 bare portion sections are arranged along the first direction (D1) of the composite portion (120).

[0076] For example, the unit width of the cut bare section (130) can be formed to be 3 mm from the composite section when the electrode assembly is wound and is close to the outermost part. In this case, the spacing at which the second cutting section (132) is placed can be 9 mm to 10 mm. The bare section sections of the bare section (130) can be formed repeatedly in units of three. In other words, two first cutting sections (131) are formed sequentially in the first direction (D1), and then one second cutting section (132) is formed. This prevents the bare section sections from fluttering because they are narrow in width and long in length. Additionally, by forming the second cutting section (132) between three bare section sections, the metal substrate (110) can be prevented from bending when the electrode travels on the roller due to the relatively large area of ​​the bare section sections.

[0077] FIG. 4 is a drawing showing an example of an electrode according to another embodiment of the present disclosure, and FIG. 5 is a drawing showing an uncoated portion spaced apart from a composite portion in an electrode according to one embodiment of the present disclosure.

[0078] The unseen portion (130) may protrude to one side of the composite portion (120) in the second direction (D2). In one embodiment, the second cutting portion (132) may be arranged repeatedly along the first direction (D1) for every three or four first cutting portions (131). The second cutting portion (132) may be formed to be 0.5 mm to 5 mm longer than the first cutting portion (131).

[0079] FIG. 4 illustrates that the bare portion (130) is cut in the second direction (D2) to form 11 cut portions, and 12 bare portion segments are arranged along the first direction (D1) of the composite portion (120). Two second cut portions (132) and nine first cut portions (131) may be arranged in the bare portion (130).

[0080] For example, the unit width of the cut bare portion (130) or the unit width of the bare portion segment may be formed to be 2 mm when the electrode assembly is wound close to the core portion. In this case, the spacing at which the second cut portion (132) is placed may be 8 mm to 10 mm.

[0081] The uncut sections of the uncut portion (130) can be formed repeatedly in units of four. In other words, three first cutting sections (1313) are formed sequentially in the first direction (D1), and then one second cutting section (132) can be formed. This prevents the cut uncut portion (130) from fluttering due to its narrow width and long length. Additionally, by forming the second cutting section (132) between the four uncut sections, the metal substrate (110) can be prevented from bending when the electrode travels on the roller due to the relatively large area of ​​the uncut section.

[0082] In one embodiment, the blank portion (130) may be folded while the metal substrate (110) is wound to form a plurality of tabs. For example, the blank portion (130) may be folded according to the cutting of the cutting portions (131, 132). The blank portion (130) may form a plurality of tabs and serve as a medium for electrical connection when applied to a secondary battery. For example, the blank portion (130) may be connected to a contact plate on the outer surface where it is folded. The blank portion (130) may be electrically connected to a case or electrode terminal through a current collector plate.

[0083] FIG. 5 shows that the non-electrode portions (130) are spaced apart at a predetermined interval along the first direction (D1). When forming an electrode assembly of a secondary battery using an electrode according to an embodiment of the present invention, the non-electrode portions of the positive electrode and the negative electrode protrude in the same direction, so the non-electrode portions of the positive electrode and the negative electrode may be spaced apart at a predetermined interval to prevent short circuits. Non-electrode portions (130) of different polarities may be spaced apart so that the respective non-electrode portions (130) separated by a separator do not overlap, and may be spaced apart in an alternating manner.

[0084] In one embodiment, each blank section (130) having a first cutting section (131) and / or a second cutting section (132) may have the same width along the first direction (D1) and the same length along the second direction (D2). Additionally, the blank sections along the first direction (D1) may be formed with different spacing between them. The spacing between blank sections (130) spaced apart along the first direction (D1) may be set considering the prevention of short circuits between the positive and negative electrodes.

[0085] FIG. 6 is a drawing showing an example of an electrode assembly according to one embodiment of the present disclosure, FIG. 7 is a drawing showing a second uncut portion in the electrode assembly of FIG. 6, and FIG. 8 is a drawing showing an example of an electrode assembly according to one embodiment of the present disclosure in which a first electrode and a second electrode are arranged in an alternating manner.

[0086] Referring to FIGS. 6 to 8, the electrode assembly may include a first electrode (100), a second electrode (200), and a separator (300). The first electrode (100) may include a first composite portion (120) coated with an active material and a first uncoated portion (130). The second electrode (200) may include a second composite portion (220) coated with an active material and a second uncoated portion (230). The separator (300) may be interposed between the first electrode (100) and the second electrode (200). The first electrode (100), the second electrode (200), and the separator (300) may be wound around a winding axis.

[0087] In order to provide a secondary battery with a unidirectional electrode structure, a second unoccupied portion (230) that is exposed at the top of the separator (300) and at risk of contacting the first unoccupied portion (130) can be cut and removed while the separator (300) is interposed between the first electrode (100) and the second electrode (200).

[0088] The first uncut portion (130) may include a first cut portion (131) and a second cut portion (132) formed repeatedly in a first direction (D1) parallel to the winding direction of the first electrode (100). The first cut portion (131) and the second cut portion (132) may extend along a second direction (D2) perpendicular to the first direction (D1). The first cut portion (131) and the second cut portion (132) may be formed by extending along the second direction (D2) from the edge of the uncut portion toward the composite portion. The first cut portion (131) and the second cut portion (132) may be formed by cutting the first uncut portion (130) along the second direction (D2) perpendicular to the first direction (D1). In one embodiment, the cutting length of the second cut portion (132) may be longer than the cutting length of the first cut portion (131). In one embodiment, the first bare section (130) may be notched by cutting both ends along the second direction (D2) to the first composite section (120). A first cutting section (131) may be positioned between the second cutting section (132) of the first bare section (130).

[0089] The second uncut portion (230) may include a third cut portion (231) and a fourth cut portion (232) formed repeatedly in a first direction (D1) parallel to the winding direction of the second electrode (200). The third cut portion (231) and the fourth cut portion (232) may extend along a second direction (D2) perpendicular to the first direction (D1). The third cut portion (231) and the fourth cut portion (232) may be formed by cutting the second uncut portion (230) along a second direction (D2) perpendicular to the first direction (D1). In one embodiment, the cutting length of the fourth cut portion (232) may be longer than the cutting length of the third cut portion (231). In one embodiment, both ends of the second uncut portion (230) may be notched by being cut along the second direction (D2) to the second composite portion (220). A third cutting section (231) may be placed between the fourth cutting section (232) of the second uncut section (230).

[0090] In one embodiment, the first unwound portion (130) may protrude to one side of the first composite portion (120) in the second direction (D2). In one embodiment, the second cutting portion (132) may be repeatedly arranged along the first direction (D1) for every one or two first cutting portions (131). The second cutting portion (132) may be formed to be 0.5 mm to 5 mm longer than the first cutting portion (131).

[0091] For example, the unit width of the first uncut section (130) or the width of the uncut section segment may be formed to be 3 mm when the electrode assembly is wound and is close to the outermost part. In this case, the spacing at which the second cutting section (132) is placed may be 9 mm to 10 mm. The first uncut section (130) cut by the first cutting section (131) may be connected in units of three on the side adjacent to the first composite section (120), thereby preventing the phenomenon of the cut first uncut section (130) fluttering due to its narrow width and long length. Additionally, by forming the second cutting section (132) between the three cut first uncut sections (130), the phenomenon of the first electrode (100) bending when the electrode travels on the roller due to the large surface area of ​​the uncut and connected uncut section segments can be prevented.

[0092] In one embodiment, the second unwound portion (230) may protrude to one side of the second composite portion (220) in the second direction (D2). In one embodiment, the fourth cutting portion (232) may be repeatedly arranged along the first direction (D1) for every one or two third cutting portions (231). The fourth cutting portion (232) may be formed to be 0.5 mm to 5 mm longer than the third cutting portion (231).

[0093] For example, the unit width of the cut second bare section (230) can be formed to be 3 mm when it is close to the outermost part while the electrode assembly is wound. In this case, the spacing at which the fourth cutting section (232) is placed can be 9 mm to 10 mm. The second bare section (230) cut by the third cutting section (231) can be connected in units of three on the side adjacent to the second composite section (220), thereby preventing the phenomenon of the cut second bare section (230) fluttering due to its thin thickness and long length. Additionally, by forming the fourth cutting section (232) between the three cut second bare sections (230), the phenomenon of the second electrode (200) bending when the electrode travels on the roller can be prevented because there are many second bare sections (230) connected without being cut.

[0094] In another embodiment, the first bare section (130) may protrude to one side of the first composite section (120) in the second direction (D2). In one embodiment, the second cutting section (132) may be repeatedly arranged every three or four first cutting sections (131) along the first direction (D1). Additionally, the second bare section (230) may protrude to one side of the second composite section (220) in the second direction (D2). In one embodiment, the fourth cutting section (232) may be repeatedly arranged every three or four third cutting sections (231) along the first direction (D1). For example, the unit width of the cut first bare section (130) or second bare section (230) may be formed to be 2 mm when close to the core of the electrode assembly in the wound state. In this case, the spacing between the second cutting section (132) or the fourth cutting section (232) may be 9 mm to 10 mm.

[0095] FIG. 8 shows that the first non-removable portion (130) and the second non-removable portion (230) are spaced apart at a predetermined interval along the first direction (D1). When forming an electrode assembly of a secondary battery using an electrode according to an embodiment of the present invention, the first electrode (100) and the second electrode (200) may be arranged with a separator (300) in between. Since the first non-removable portion (130) and the second non-removable portion (230) protrude in the same direction in the second direction (D2), the first non-removable portion (130) and the second non-removable portion (230) may be spaced apart at a predetermined interval to prevent short circuits.

[0096] In one embodiment, the electrode assembly may be formed such that the first non-existent portion (130) and the second non-existent portion (230) protruding in the second direction (D2) of the separator (300) do not overlap. For example, the second non-existent portion (230) may be positioned between the first non-existent portion (130) in a spaced-apart space so that each non-existent portion is positioned in an intersecting manner.

[0097] FIG. 9 is a drawing showing an example of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure, FIG. 10 is a drawing showing the upper surface of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure, FIG. 11 is a drawing showing the lower surface of an electrode assembly applied to a secondary battery according to one embodiment of the present disclosure, FIG. 12 is a drawing showing the first uncoated portion and the second uncoated portion of an electrode assembly according to one embodiment of the present disclosure in a bent state, and FIG. 13 is a cross-sectional view showing an example of a secondary battery according to one embodiment of the present disclosure.

[0098] The electrode assembly (10) may be formed by winding a first electrode (100) including a first non-removable portion (130), a second electrode (200) including a second non-removable portion (230), and a separator (300). In one embodiment, the outer surface of the electrode assembly (10) may include one or more of the first non-removable portion (130) and the second non-removable portion (230) constituting the separator (300) or the electrode. The outer surface of the electrode assembly (10) may be one end of the separator (300) that is extended from the separator (300) to prevent the active material constituting the first electrode (100) or the second electrode (200) from being exposed to the outside. Additionally, the outer surface of the electrode assembly (10) may be formed as an extended end of a first uncoated portion (130) and a second uncoated portion (230) on which the active material constituting the first electrode (100) or the second electrode (200) is not coated.

[0099] For example, the first electrode (100) can function as a negative electrode. The negative electrode substrate may be composed of, for example, copper foil or nickel foil, and the negative electrode active material may include, for example, graphite. The negative electrode active material includes a material capable of reversibly intercalating / deintercalating lithium ions, lithium metal, an alloy of lithium metal, a material capable of doping and dedoping lithium, or a transition metal oxide. A material capable of reversibly intercalating / deintercalating lithium ions may be a carbon-based negative electrode active material, for example, crystalline carbon, amorphous carbon, or a combination thereof. Examples of crystalline carbon include graphite such as natural graphite or artificial graphite, and examples of amorphous carbon include soft carbon or hard carbon, mesophase pitch carbide, calcined coke, etc.

[0100] As the above lithium metal alloy, an alloy of lithium and a metal selected from Na, K, Rb, Cs, r, Be, Mg, Ca, Sr, Si, Sb, Pb, In, Zn, Ba, Ra, Ge, Al, and Sn may be used.

[0101] As a material capable of doping and undoping the above lithium, a Si-based negative electrode active material or a Sn-based negative electrode active material may be used. The Si-based negative electrode active material may be silicon, a silicon-carbon composite, SiOx (0 < x < 2), a Si-Q alloy (wherein Q is selected from alkali metals, alkaline earth metals, group 13 elements, group 14 elements (excluding Si), group 15 elements, group 16 elements, transition metals, rare earth elements, and combinations thereof), or a combination thereof. The Sn-based negative electrode active material may be Sn, SnO2, a Sn-based alloy, or a combination thereof.

[0102] The silicon-carbon composite may be a composite of silicon and amorphous carbon. According to one embodiment, the silicon-carbon composite may be in the form of silicon particles and amorphous carbon coated on the surface of the silicon particles. For example, it may include a secondary particle (core) assembled from silicon primary particles and an amorphous carbon coating layer (shell) located on the surface of the secondary particle. The amorphous carbon may also be located between the silicon primary particles, so that, for example, the silicon primary particles may be coated with amorphous carbon. The secondary particles may be dispersed in an amorphous carbon matrix.

[0103] The silicon-carbon composite may further include crystalline carbon. For example, the silicon-carbon composite may include a core comprising crystalline carbon and silicon particles and an amorphous carbon coating layer located on the surface of the core.

[0104] The above Si-based or Sn-based negative electrode active material can be used in combination with a carbon-based negative electrode active material.

[0105] For example, the second electrode (200) can function as a positive electrode. The positive electrode substrate may be composed of aluminum foil, and the positive electrode active material may include, for example, a transition metal oxide. As the positive electrode active material, a compound capable of reversible intercalation and deintercalation of lithium (a lithated intercalation compound) may be used. Specifically, one or more composite oxides of lithium and a metal selected from cobalt, manganese, nickel, and combinations thereof may be used. The composite oxide may be a lithium transition metal composite oxide, and specific examples may include a lithium nickel-based oxide, a lithium cobalt-based oxide, a lithium manganese-based oxide, a lithium iron phosphate-based compound, a cobalt-free nickel-manganese-based oxide, or a combination thereof.

[0106] As an example, a compound represented by any one of the following chemical formulas may be used. Li a A 1-b X b O 2-c D c (0. 90≤a≤1. 8, 0≤b≤0. 5, 0≤c≤0. 05); Li a Mn 2-b X b O 4-c D c (0. 90≤a≤1. 8, 0≤b≤0. 5, 0≤c≤0. 05); Li a Ni 1-b-c Co b X c O 2-α D α (0. 90≤a≤1. 8, 0≤b≤0. 5, 0≤c≤0. 5, 0<α<2); Li a Ni 1-b-c Mn b X c O 2-α D α (0. 90≤a≤1. 8, 0≤b≤0. 5, 0≤c≤0. 5, 0<α<2); Li a Ni b Co c L 1 d G eO2(0. 90≤a≤1. 8, 0≤b≤0. 9, 0≤c≤0. 5, 0≤d≤0. 5, 0≤e≤0. 1); Li a NiG b O2(0. 90≤a≤1. 8, 0. 001≤b≤0. 1); Li a CoG b O2(0. 90≤a≤1. 8, 0. 001≤b≤0. 1); Li a Mn 1-b G b O2(0. 90≤a≤1. 8, 0. 001≤b≤0. 1); Li a Mn2G b O4(0. 90≤a≤1. 8, 0. 001≤b≤0. 1); Li a Mn 1-g G g PO4(0. 90≤a≤1. 8, 0≤g≤0. 5); Li (3-f) Fe2(PO4)3(0≤f≤2); Li a FePO4(0.90≤a≤1.8).

[0107] In the above chemical formula, A is Ni, Co, Mn, or a combination thereof; X is Al, Ni, Co, Mn, Cr, Fe, Mg, Sr, V, a rare earth element, or a combination thereof; D is O, F, S, P, or a combination thereof; G is Al, Cr, Mn, Fe, Mg, La, Ce, Sr, V, or a combination thereof; L 1 is Mn, Al, or a combination thereof.

[0108] For example, the above-mentioned positive electrode active material may be a high-nickel positive electrode active material in which the nickel content relative to 100 mol% of the metal excluding lithium in the lithium transition metal composite oxide is 80 mol% or more, 85 mol% or more, 90 mol% or more, 91 mol% or more, or 94 mol% or more and 99 mol% or less. The high-nickel positive electrode active material can achieve high capacity and can be applied to high-capacity, high-density lithium secondary batteries.

[0109] As the separator (300), polyethylene, polypropylene, polyvinylidene fluoride, or a multilayer film of two or more layers thereof may be used, and of course, a mixed multilayer film such as a polyethylene / polypropylene two-layer separator, a polyethylene / polypropylene / polyethylene three-layer separator, or a polypropylene / polyethylene / polypropylene three-layer separator may be used. The separator may include a porous substrate and a coating layer comprising an organic material, an inorganic material, or a combination thereof located on one or both sides of the porous substrate.

[0110] The porous substrate may be a polymer membrane formed from any one of the following: polyolefins such as polyethylene and polypropylene; polyesters such as polyethylene terephthalate and polybutylene terephthalate; polyacetal; polyamide; polyimide; polycarbonate; polyetherketone; polyaryletherketone; polyetherimide; polyamideimide; polybenzimidazole; polyethersulfone; polyphenylene oxide; cyclic olefin copolymer; polyphenylene sulfide; polyethylene naphthalate; glass fiber; Teflon; and polytetrafluoroethylene, or a copolymer or mixture of two or more of these.

[0111] The organic material may include a polyvinylidene fluoride-based polymer or a (meth)acrylic-based polymer. The inorganic material is Al2O3, SiO2, TiO2, SnO2, CeO2, MgO, NiO, CaO, GaO, ZnO, ZrO2, Y2O3, It may include, but is not limited to, inorganic particles selected from SrTiO3, BaTiO3, Mg(OH)2, boehmite, and combinations thereof. Organic and inorganic materials may exist mixed in a single coating layer, or may exist in a stacked form with a coating layer containing organic material and a coating layer containing inorganic material.

[0112] A secondary battery according to one embodiment of the present disclosure may include an electrode assembly (10) that performs charging and discharging, a case (20) that houses the electrode assembly (10), a vent cap plate (30), and an electrode terminal (40). Although FIG. 13 is illustrated with the vent cap plate (30) positioned on the upper part of the secondary battery and the electrode terminal (40) positioned on the lower part of the secondary battery, it is not limited thereto. Depending on the usage environment or requirements of the secondary battery, the vent cap plate (30) and the electrode terminal (40) may be changed to be positioned on the lower part and the upper part of the secondary battery, respectively.

[0113] The electrode assembly (10) can be formed into a cylindrical jelly roll shape with an empty core by winding the first electrode (100), the separator (300), and the second electrode (200). In one embodiment, the case (20) can form the overall exterior of the secondary battery. The case (20) is formed as a cylinder to house the electrode assembly (10), and the electrode terminal (40) and the vent cap plate (30) can be provided at each axial end of the case (20) so as to face each other. The vent cap plate (30) can seal the electrode assembly (10) from the outside while covering one open side of the case (20).

[0114] For the purpose of explaining the invention, the secondary battery described below is illustrated in the form of a cylindrical secondary battery, but the scope of the present disclosure is not limited thereto. The secondary battery of the present invention is not limited to a cylindrical secondary battery and includes secondary batteries of any shape, such as prismatic secondary batteries, pouch secondary batteries, and coin secondary batteries.

[0115] In one embodiment, the secondary battery may be formed with a beadingless structure as shown in FIG. 13. Compared to a secondary battery of the same size, the beadingless structure can increase capacity and output by utilizing the space inside the case (20). In addition, according to one embodiment of the present invention, when an electrode assembly (10) with a unidirectional current collection structure is applied, the positive and negative electrodes are placed on one side to maximize the utilization of the internal space of the case (20). Furthermore, unlike a structure where the positive and negative electrodes are placed on opposite sides, the positive and negative current paths are on one side, thereby lowering the internal resistance and improving the output of the secondary battery.

[0116] The case (20) may be formed of a conductive metal such as aluminum, aluminum alloy, stainless steel (e.g., SUS), or nickel-plated steel. The case (20) may have a fully open opening formed on one side to allow the electrode assembly (10) to be inserted. The case (20) may have a through hole formed on the other side to accommodate an electrode terminal (40).

[0117] A vent cap plate (30) can be fastened to an open side of the case (20). The vent cap plate (30) can be coupled to seal the opening after the electrode assembly (10) is inserted into the case (20). The vent cap plate (30) can be welded to at least a part of the case (20) to seal the case (20).

[0118] The vent cap plate (30) is configured to cover the opening of the case (20) and seals the interior of the secondary battery from the external environment to prevent leakage of electrolyte, etc., protects the internal components of the secondary battery from external moisture or dust, and provides a welded or contact area to an external component (e.g., an external terminal) to electrically connect the secondary battery cell.

[0119] For example, the vent cap plate (30) may include an alloy such as Alnico, Permalloy, Silicon Steel, Neodymium (NdFeB), composed of iron (Fe), nickel (Ni), cobalt (Co), manganese (Mn), zinc (Zn), chromium (Cr), titanium (Ti), or a combination including these.

[0120] The vent cap plate (30) may be welded to the opening of the case (20) using any one of ultrasonic welding, laser welding, resistance welding, TIG welding (Tungsten Inert Gas Welding), or a combination thereof. The welding method is not limited to the types of welding listed above, and various methods generally used for welding two materials may be used at the choice of a person skilled in the art.

[0121] In one embodiment, the vent cap plate (30) may include a notch configured to break when pressure exceeding a set value is applied. The vent cap plate (30) may function as a vent that deforms or ruptures when the internal pressure of the secondary battery exceeds a certain pressure, thereby releasing gas generated inside the secondary battery to the outside of the secondary battery. For example, the vent cap plate (30) may include a cylindrical notch.

[0122] The first unwound portion (130) and the second unwound portion (230) may be spaced apart and protrude from one side of the electrode assembly (10). For example, the first unwound portion (130) and the second unwound portion (230) may be arranged to extend radially from the core portion (11) of the electrode assembly (10) toward the outermost portion (12).

[0123] Additionally, the first unwound section (130) and the second unwound section (230) can be arranged in a fan shape, with the number of distributed in the circumferential direction increasing from the core section (11) of the electrode assembly (10) to the outermost section (12). In one embodiment, the first unwound section (130) can be folded while overlapping toward the core section (11). The second unwound section (230) can be folded while overlapping toward the core section (11).

[0124] In one embodiment, the first unwound portion (130) may be folded while the electrode assembly (10) is wound to form a plurality of first tabs and may be folded at the end of the separator (300) adjacent to the first composite portion (120). The second unwound portion (230) may be folded while the electrode assembly (10) is wound to form a plurality of second tabs and may be folded at the end of the separator (300) adjacent to the second composite portion (220).

[0125] As shown in FIG. 12, the distance (d1) from the point where the first bare part (130) is bent to the end of the second bare part (230) can be formed such that there is no mutual contact and no short circuit occurs.

[0126] Additionally, the distance (d2) from the point where the second bare section (230) is bent to the end of the first bare section (130) can be formed such that there is no mutual contact and no short circuit occurs. For example, an insulating coating layer (140) is formed on both sides of the second bare section (230), so that the distance (d2) from the point where the second bare section (230) is bent to the end of the first bare section (130) is shorter than the distance (d1) from the point where the first bare section (130) is bent to the end of the second bare section (230).

[0127] The case (20) can accommodate an electrode assembly (10) and be electrically connected to the first electrode (100). The electrode terminal (40) is positioned through a through hole and can be electrically connected to the second electrode (200). In one embodiment, the secondary battery may further include a first current collector plate (50) which is coupled to one end of the case (20) and electrically connected to the first non-conducting portion (130), and a second current collector plate (60) which is coupled to one end of the electrode terminal (40) and electrically connected to the second non-conducting portion (230). Additionally, the secondary battery may further include a first gasket (70) that insulates the first current collector plate (50) and the second current collector plate (60). Additionally, it may include a second gasket (80) that electrically insulates the case (20) and the electrode terminal (40).

[0128] FIG. 14 is an exploded perspective view showing a part of the configuration of a secondary battery according to one embodiment of the present disclosure, FIG. 15 is a perspective view showing a part of the configuration of a secondary battery according to one embodiment of the present disclosure, and FIG. 16 is an enlarged view of area A of FIG. 13.

[0129] In one embodiment, the first current collector plate (50) is coupled to one end of the case (20) and can be electrically connected to the first non-electrical portion (130). The second current collector plate (60) is coupled to one end of the electrode terminal (40) and can be electrically connected to the second non-electrical portion (230).

[0130] For example, the first current collector plate (50) may be formed to expand radially from the core (11) of the electrode assembly (10) to the outermost part (12). The shape of the first current collector plate (50) may correspond to the overlapping folded arrangement shape of the first non-circular part (130). Additionally, the second current collector plate (60) may be formed to expand radially from the core (11) of the electrode assembly (10) to the outermost part (12). The shape of the second current collector plate (60) may correspond to the overlapping folded arrangement shape of the second non-circular part (230). The first current collector plate (50) and the second current collector plate (60) may be formed from a conductive metal material.

[0131] The first current collector plate (50) and the second current collector plate (60) may be spaced apart and facing each other on the upper surface of the electrode assembly (10). The first current collector plate (50) may be placed on the upper part of the first non-circular portion (130). The first non-circular portion (130) may be folded while overlapping toward the winding core (11) and connected to the first current collector plate (50), and the second non-circular portion (230) may be folded while overlapping toward the winding core (11) and connected to the second current collector plate (60).

[0132] The first current collector plate (50) can be connected in contact with the first non-contacting portion (130). The first current collector plate (50) can be welded to the first non-contacting portion (130). The first current collector plate (50) can be electrically connected to the first non-contacting portion (130). The first current collector plate (50) can be connected to the case (20). The case (20) can be connected to the first electrode (100) through the first current collector plate (50). The first current collector plate (50) can be connected to the case (20) in a structure that reduces resistance by contacting most of the area with the first non-contacting portion (130).

[0133] The second current collector plate (60) can be connected in contact with the second non-contacting portion (230). The second current collector plate (60) can be welded to the second non-contacting portion (230). The second current collector plate (60) can be electrically connected to the second non-contacting portion (230). The second current collector plate (60) can be connected to the electrode terminal (40). The electrode terminal (40) can be connected to the second electrode (200) through the second current collector plate (60). The second current collector plate (60) can be electrically connected to the electrode terminal (40) in a structure that reduces resistance by contacting most of the area of ​​the second non-contacting portion (230) of the second electrode (200).

[0134] In one embodiment, the first gasket (70) may be placed between the first collector plate (50) and the second collector plate (60) to insulate the first collector plate (50) and the second collector plate (60). For example, the first gasket (70) may be made of a polymer comprising ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0135] As another example, the first gasket (70) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the first gasket (70) is not limited to the materials listed above and may include various materials with excellent plasticity and insulation properties depending on the choice.

[0136] In one embodiment, the secondary battery may further include a second gasket (80) that is provided in a through hole (21) and electrically insulates the case (20) and the electrode terminal (40). The through hole (21) may be formed on the other side (or bottom surface) of the case (20) opposite to the side where the opening is formed. The through hole (21) may be formed by partially opening the other side of the case (20). The electrode terminal (40) may be arranged in a rivet structure in the through hole (21).

[0137] The electrode terminal (40) can be connected to the second electrode (200) via the second current collector plate (60) through the through hole (21). The electrode terminal (40) connected to the second electrode (200) of the electrode assembly (10) inserted into the case (20) from the outside can be placed in the through hole (21).

[0138] For example, one end of the electrode terminal (40) may be welded to the second current collector plate (60). The other end of the electrode terminal (40) may be positioned on the outside of the case (20). The electrode terminal (40) may be formed to protrude above the outer surface of the case (20) around the through hole (21) and used as a positive terminal. In this case, the second current collector plate (60) may be a positive current collector plate.

[0139] At this time, the second current collector plate (60) can be electrically connected to the second non-removable portion (230) of the second electrode (200) and electrically and mechanically connected to the electrode terminal (40). The second current collector plate (60) can be electrically connected to the electrode terminal (40) in a structure that reduces resistance by contacting most of the area of ​​the second non-removable portion (130).

[0140] In one embodiment, the secondary battery may further include a second gasket (80) that is provided in a through hole (21) and electrically insulates the case (20) and the electrode terminal (40). The second gasket (80) may be positioned in an electrically insulated state from the case (20) while forming a hermetic structure with respect to the electrolyte inside the case (20).

[0141] For example, the second gasket (80) may be made of a polymer comprising ethylene propylene rubber (EPDM), polypropylene (PP), polyimide (PI), polyethylene terephthalate (PET), polycarbonate (PC), or a combination thereof.

[0142] As another example, the second gasket (80) may be made of a ceramic material including epoxy resin, alumina (Al2O3), zirconia (ZrO2), aramid fiber, Nomex, or a combination thereof. However, the material of the second gasket (80) is not limited to the materials listed above and may include various materials with excellent plasticity and insulation properties depending on the choice.

[0143] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

Claims

1. Metal substrate; A blank portion formed at the end of the metal substrate; and A composite portion formed on a part of the above metal substrate Includes, The above-mentioned blank portion includes a first cutting portion and a second cutting portion formed repeatedly in a first direction parallel to the winding direction of the metal substrate, and The first cutting portion and the second cutting portion extend along a second direction perpendicular to the first direction, and The cutting length of the second cutting section is longer than that of the first cutting section, and An electrode in which a first cutting portion is disposed between the second cutting portions.

2. In Paragraph 1, The above second cutting part is, Electrodes repeatedly arranged for every one or two of the first cutting sections along the first direction.

3. In Paragraph 1, The above second cutting part is, Electrodes repeatedly arranged for every three or four of the first cutting sections along the first direction.

4. In Paragraph 1, The above second cutting part is, An electrode formed to be 0.5 mm to 5 mm longer than the first cut portion.

5. In Paragraph 1, The above-mentioned part is, An electrode formed by folding the above-mentioned material while it is wound to form a plurality of tabs, and being folded at the end of the first cutting portion adjacent to the composite portion.

6. A first electrode comprising a first composite portion coated with an active material and a first uncoated portion; A second electrode comprising a second composite portion coated with an active material and a second uncoated portion; and A separator interposed between the first electrode and the second electrode Includes, The first electrode, the second electrode, and the separator are wound around a winding axis, and The above-mentioned first part of the non-disability section is, It includes a first cutting section and a second cutting section formed repeatedly in a first direction parallel to the winding direction of the first electrode, wherein the first cutting section and the second cutting section extend along a second direction perpendicular to the first direction, the cutting length of the second cutting section is longer than that of the first cutting section, and the first cutting section is disposed between the second cutting sections. The above second non-removable part is, An electrode assembly comprising a third cutting section and a fourth cutting section formed repeatedly in a first direction parallel to the winding direction of the second electrode, wherein the third cutting section and the fourth cutting section extend along a second direction perpendicular to the first direction, the cutting length of the fourth cutting section is longer than that of the third cutting section, and the third cutting section is disposed between the fourth cutting sections.

7. In Paragraph 6, The above second cutting part is, They are repeatedly arranged along the first direction for every one or two of the first cutting sections, and The above-mentioned fourth cutting section is, An electrode assembly that is repeatedly arranged for every one or two of the third cutting sections along the first direction.

8. In Paragraph 6, The above second cutting part is, They are repeatedly arranged along the first direction for every three or four of the first cutting sections, and The above-mentioned fourth cutting section is, An electrode assembly that is repeatedly arranged every three or four of the third cutting sections along the first direction.

9. In Paragraph 6, The above second cutting part is, It is formed to be 0.5 mm to 5 mm longer than the first cutting portion, and The above-mentioned fourth cutting section is, An electrode assembly formed to be 0.5 mm to 5 mm longer than the third cut portion.

10. An electrode assembly having a first electrode including a first non-removable portion, a second electrode including a second non-removable portion, and a separator wound thereon; A case having one side open and a through hole formed on the other side, accommodating the electrode assembly and electrically connected to the first electrode; A vent cap plate fastened to one open side of the above case; and An electrode terminal disposed through the above-mentioned through-hole and electrically connected to the second electrode. Includes, The above-mentioned first part of the non-disability section is, It includes a first cutting section and a second cutting section formed repeatedly in a first direction parallel to the winding direction of the first electrode, wherein the first cutting section and the second cutting section extend along a second direction perpendicular to the first direction, the cutting length of the second cutting section is longer than that of the first cutting section, and the first cutting section is disposed between the second cutting sections. The above second non-removable part is, A secondary battery comprising a third cutting section and a fourth cutting section formed repeatedly in a first direction parallel to the winding direction of the second electrode, wherein the third cutting section and the fourth cutting section extend along a second direction perpendicular to the first direction, the cutting length of the fourth cutting section is longer than that of the third cutting section, and the third cutting section is disposed between the fourth cutting sections.

11. In Paragraph 10, The above-mentioned first non-removable portion and the above-mentioned second non-removable portion are A secondary battery protruding from one side of the above electrode assembly and spaced apart from each other.

12. In Paragraph 10, The above-mentioned first non-removable portion and the above-mentioned second non-removable portion are A secondary battery arranged to expand radially from the core of the electrode assembly toward the outermost part.

13. In Paragraph 10, The above-mentioned first non-removable portion and the above-mentioned second non-removable portion are A secondary battery in which the number of electrodes distributed in the circumferential direction increases from the core of the electrode assembly to the outermost part and is arranged in a fan shape.

14. In Paragraph 10, A first current collector plate coupled to one end of the above case and electrically connected to the first non-removable part; A second current collector plate having one end coupled to the electrode terminal and electrically connected to the second non-electrical portion. A secondary battery that further includes 15. In Paragraph 14, The first current collector plate and the second current collector plate are spaced apart and facing each other, A first gasket disposed between the first current collector plate and the second current collector plate to insulate the first current collector plate and the second current collector plate. A secondary battery that further includes 16. In Paragraph 14, The above-mentioned first non-removable portion is folded while overlapping toward the above-mentioned core portion and connected to the above-mentioned first collector plate, and A secondary battery in which the second non-removable portion is folded while overlapping toward the core portion and connected to the second current collector plate.

17. In Paragraph 10, A secondary battery further comprising a second gasket provided in the through hole and electrically insulating the case and the electrode terminal.

18. In Paragraph 10, The above second cutting part is, They are repeatedly arranged along the first direction for every one or two of the first cutting sections, and The above-mentioned fourth cutting section is, A secondary battery that is repeatedly arranged at every one or two of the third cutting sections along the first direction.

19. In Paragraph 10, The above-mentioned first part of the non-disability section is, The above electrode assembly is bent while in a wound state to form a plurality of first tabs, and is bent at the end of the separator adjacent to the first composite part, and The above second non-removable part is, A secondary battery in which the electrode assembly is bent while in a wound state to form a plurality of second tabs, and is bent at the end of the separator adjacent to the second composite part.

20. In Paragraph 10, The above second cutting part is, They are repeatedly arranged along the first direction for every three or four of the first cutting sections, and The above-mentioned fourth cutting section is, A secondary battery that is repeatedly arranged every three or four of the third cutting sections along the first direction.

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