Roll core, secondary battery, battery pack, and vehicle

Abstract

The invention provides a winding core, a secondary battery, a battery pack and a vehicle. The winding core includes an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound, and a tube structure surrounding at least a portion of a side surface of the electrode assembly and at least a portion of one end portion of the electrode assembly perpendicular to a winding axis. The tube structure includes a hole formed at a center of one end of the electrode assembly perpendicular to the winding axis.

Description

Technical Field

[0001] The invention relates to a winding core, a secondary battery, a battery pack and a vehicle.

[0002] This application claims priority to and the benefit of Korean Patent Application No. 10-2022-0154665 filed in the Korean Intellectual Property Office on November 17, 2022, the entire contents of which are incorporated herein by reference. Background Art

[0003] Secondary batteries are widely used not only in portable devices but also in electric vehicles (EVs), hybrid electric vehicles (HEVs), etc. driven by electric drive sources due to their easy application to various products and electrical characteristics such as high energy density.

[0004] Secondary batteries are attracting attention as a new energy source that improves eco-friendliness and energy efficiency due to their primary advantage of significantly reducing the use of fossil fuels and their secondary advantage of using energy without generating byproducts.

[0005] Currently widely used secondary batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of a unit secondary battery cell is about 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack can be constructed by connecting a plurality of secondary batteries in series. In addition, a battery pack can be constructed by connecting a plurality of secondary batteries in parallel according to the charge / discharge capacity required for the battery pack. Therefore, the number of secondary batteries included in the battery pack and the form of electrical connection can be set in various ways according to the required output voltage and / or charge / discharge capacity.

[0006] Note that as types of secondary batteries, cylindrical, square and pouch-type secondary batteries are known. The above-mentioned secondary battery may be a cylindrical secondary battery. In the secondary battery, a diaphragm as an insulator is inserted between the positive electrode and the negative electrode, which is then wound to form a roll-type electrode assembly, and the electrode assembly is inserted into a battery can together with an electrolyte to construct a battery. A strip-shaped electrode connector may be connected to an uncoated portion of each of the positive and negative electrodes, and the electrode connector electrically connects the electrode assembly and the electrode terminal exposed to the outside. For reference, the positive terminal is a cover plate of a sealing body that seals the opening portion of the battery can, and the negative terminal is a battery can.

[0007] According to the related art secondary battery having such a structure, current is concentrated on the strip-shaped electrode tab connected to the positive electrode uncoated portion and / or the negative electrode uncoated portion, so resistance is large, a large amount of heat is generated, and current collecting efficiency is poor.

[0008] For a small cylindrical secondary battery having a form factor of 18650 or 21700, resistance and heat generation are not major issues. However, when the form factor of a cylindrical secondary battery is increased in order to apply the cylindrical secondary battery to an electric vehicle, the following problem may occur: during a fast charging process, the cylindrical secondary battery catches fire due to a large amount of heat generated around the electrode joint. Therefore, there is a need to develop a cylindrical secondary battery with an increased form factor. Summary of the invention

[0009] Technical issues

[0010] The present invention is directed to providing a winding core and a secondary battery capable of achieving high energy density by including a tube structure disposed to surround a side surface of an electrode assembly and one end portion of the electrode assembly perpendicular to a winding axis.

[0011] Another object of the present invention is to provide a battery pack including a secondary battery having the improved structure as above and a vehicle including the battery pack.

[0012] However, the technical problems to be solved by the present invention are not limited to the above-mentioned problems, and other problems not described will be clearly understood by those skilled in the art from the following description.

[0013] Technical Solution

[0014] An exemplary embodiment of the present invention provides a winding core, which includes: an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and a tube structure, which is configured to surround at least a portion of a side surface of the electrode assembly and at least a portion of an end of the electrode assembly perpendicular to a winding axis, wherein the tube structure is configured to include a hole formed in a central portion of one end of the electrode assembly perpendicular to the winding axis.

[0015] Another exemplary embodiment of the present invention provides a secondary battery, comprising: a winding core according to an exemplary embodiment of the present invention; and a battery can configured to accommodate the winding core, wherein the battery can comprises an electrode terminal riveted via a through hole formed in the bottom of the battery can, and a gasket disposed between the electrode terminal and an outer diameter portion of the through hole.

[0016] Still another exemplary embodiment of the present invention provides a battery pack including the secondary battery according to the above exemplary embodiment.

[0017] Yet another exemplary embodiment of the present invention provides a vehicle including the battery pack according to the above exemplary embodiment.

[0018] Technical Effects

[0019] In order to develop secondary batteries that require high capacity and high output, the positive electrode uncoated portion and the negative electrode uncoated portion are respectively located at one end of the core-wound electrode assembly perpendicular to the winding axis and the other end as the opposite surface of the one end, and the current collector plate is welded to the uncoated portion, thereby improving the current collection efficiency. This makes it possible to reduce the internal resistance of the secondary battery and increase the energy density.

[0020] In the prior art, after the positive current collector plate of the electrode assembly is laser welded to the positive uncoated portion, an insulating tape is attached to the exposed uncoated portion and the current collector plate to insulate the uncoated portion and the portion of the current collector plate in contact with the battery can. Attaching the insulating tape is disadvantageous in terms of appearance quality and workmanship, and causes a problem in which the insulating tape falls off due to wrinkles or bulges when the winding core is inserted into the battery can.

[0021] According to an exemplary embodiment of the present invention, a tube structure is provided to surround at least a portion of a side surface of an electrode assembly and one end of the electrode assembly perpendicular to a winding axis, so that the problem of wrinkling or bulging of the insulating tape does not occur, so that the insulation quality can be improved, the cycle time required to produce one product can be shortened, and the processing capacity can be improved. In addition, it is easy to insert into a battery can and easy to rework, which is also conducive to cost saving.

[0022] This allows the current applied to the battery to be stably increased, achieving high energy density, and providing a high-capacity, high-power secondary battery.

[0023] However, advantageous effects to be obtained by the present invention are not limited to the above-mentioned effects, and other effects not described herein can be clearly understood by those skilled in the art from the following description of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings illustrate preferred exemplary embodiments of the present invention and, together with the following description of the present invention, serve to provide a further understanding of the technical spirit of the present invention, and therefore, the present invention should not be construed as being limited to the accompanying drawings.

[0025] Figure 1 (a) and Figure 1 (b) are views schematically showing a winding core including a tube structure according to an exemplary embodiment of the present invention.

[0026] Figure 2 is a view schematically showing a structure of a secondary battery including a winding core according to an exemplary embodiment of the present invention.

[0027] Figure 3The present invention is a comparative example of a winding core with an insulating tape attached thereto, and shows (a) a process, (b) one end of an electrode assembly perpendicular to the winding axis, (c) the insulating tape in the form of wrinkles and ridges, and (d) the insulating tape falling off when inserted into a battery can.

[0028] Figure 4 are photographs showing (a) a process, (b) one end portion of an electrode assembly perpendicular to a winding axis, and (c) a side surface of an electrode assembly in a tube structure of a small cylindrical secondary battery having a form factor of 21700 according to a comparative example of the present invention.

[0029] Figure 5 is a view showing a schematic configuration of a battery pack including a secondary battery according to an exemplary embodiment of the present invention.

[0030] Figure 6 is a view illustrating a schematic configuration of a vehicle including a battery pack according to an exemplary embodiment of the present invention.

[0031] [Explanation of Reference Numerals]

[0032] 1: Electrode assembly

[0033] 2: Side surface of electrode assembly

[0034] 3: One end of the electrode assembly perpendicular to the winding axis

[0035] 4: The other end of the electrode assembly perpendicular to the winding axis

[0036] 6: Uncoated part of the positive electrode

[0037] 7: Positive current collector plate

[0038] 10: Tube structure

[0039] 11: Holes in tube structures

[0040] 12A: Area of ​​the tube structure provided at the end of the electrode assembly perpendicular to the winding axis

[0041] 12W: Width of the tube structure provided at the end of the electrode assembly perpendicular to the winding axis

[0042] 20: Core

[0043] 30: Secondary battery

[0044] 31: Battery Can

[0045] 40: Battery Pack

[0046] 50: Battery pack housing

[0047] 60: Vehicles

[0048] 100: Electrode terminal

[0049] 110: Main part

[0050] 120: Outer flange part

[0051] 130: Inner flange part

[0052] 140: Flat part

[0053] 200: Bottom of battery tank

[0054] 300: Through hole

[0055] 400: Washer

[0056] C: Winding axis DETAILED DESCRIPTION

[0057] The terms or words used in the specification and claims should not be construed as limited to their ordinary meanings or dictionary meanings, but should be construed as having meanings and concepts consistent with the technical concept of the present invention based on the principle that the inventor can appropriately define the concepts of the words or terms to best explain the present invention.

[0058] The terms used in this specification are only used to describe various exemplary embodiments of the present invention and are not intended to limit the present invention. Unless the context clearly indicates otherwise, the singular forms "a", "an" and "the" are intended to include the plural forms.

[0059] In the present specification, it should be understood that terms such as “include,” “comprising,” “provide,” or “have” are used to describe the presence of specific components, and do not exclude the possibility of the presence of other components or the addition of other components.

[0060] Furthermore, terms such as “part” and “means” described in the specification should be understood as units that perform at least one function or operation.

[0061] In the present specification, the expression “existing on” a specific component is intended to mean “existing on” “one side” of the specific component, and is not intended to restrict the upper and lower relationship and is not limited to physical contact with the component, but means that another member may be additionally disposed between the components.

[0062] In this specification, unlike an insulating tape, a "tube structure" refers to a structure that surrounds a winding core without a seam.

[0063] The configurations described with reference to the accompanying drawings in the following description do not represent all technical concepts or ideas of the present invention, but should be considered as exemplary embodiments of the present disclosure. Therefore, it should be understood that various modifications and equivalents of the exemplary embodiments can be designed within the scope of the present invention when the application is submitted.

[0064] To help understanding the present invention, in the drawings, some components may not be drawn to scale, but their sizes may be exaggerated. In addition, the same reference numerals may be assigned to the same components in different exemplary embodiments.

[0065] Hereinafter, exemplary embodiments of the present invention will be described with reference to the accompanying drawings.

[0066] An exemplary embodiment of the present invention provides a winding core comprising: an electrode assembly having a structure in which a positive electrode, a separator, and a negative electrode are stacked and wound; and a tube structure configured to surround at least a portion of a side surface of the electrode assembly and at least a portion of an end of the electrode assembly perpendicular to a winding axis, wherein the tube structure is configured to include a hole formed at a central portion of one end of the electrode assembly perpendicular to the winding axis.

[0067] The tube structure is different from the insulating tape and refers to a structure that surrounds the roll core without a seam.

[0068] The invention comprises a tube structure arranged to surround the side surface of the electrode assembly and at least a portion of one end of the electrode assembly perpendicular to the winding axis, so that no wrinkles or bulges occur compared to an insulating tape, so that the insulation quality can be improved, the cycle time required to produce one product can be shortened, and the processing capacity can be improved. In addition, it is convenient to insert into the battery can and easy to rework, which is also conducive to cost saving.

[0069] The tube structure has a shape in which a hole is formed in a central portion of one end portion of the electrode assembly perpendicular to the winding axis, so that the one end portion is open, making it easy to apply the tube structure to the electrode assembly. Specifically, the tube fabric for the tube structure is provided in a reel type so that it can be cut and fed, which facilitates the process of producing the tube structure including the hole.

[0070] Figure 1 (a) and Figure 1 (b) are views schematically showing a winding core including a tube structure according to an exemplary embodiment of the present invention.

[0071] Reference Figure 1 (a) and Figure 1 In (b), a tube structure 10 may be provided to surround at least a portion of a side surface 2 of the electrode assembly and at least a portion of one end 3 of the electrode assembly perpendicular to the winding axis.

[0072] For secondary batteries that require high capacity and high output, the positive uncoated portion and the negative uncoated portion can be located at one end of the electrode assembly perpendicular to the winding axis and the other end opposite to the one end, respectively, and the current collector plate can be welded to the uncoated portion to improve the current collection efficiency. This makes it possible to reduce the internal resistance of the secondary battery and increase the energy density. After the positive current collector plate 7 of the electrode assembly 1 is laser welded to the positive uncoated portion 6, a tube structure 10 may be included to insulate the portion where the positive uncoated portion 6 and the positive current collector plate 7 are in contact with the battery can 31.

[0073] A tube structure 10 is included, which is arranged to surround a side surface 2 of the electrode assembly and an end 3 of the electrode assembly perpendicular to the winding axis, where the positive electrode uncoated portion 6 and the positive electrode current collector plate 7 are exposed and may therefore contact the battery can 31, so that the insulation quality can be improved and the electrode assembly can be easily inserted into the battery can.

[0074] Reference Figure 1 (a), according to an exemplary embodiment of the present invention, the tube structure 10, which is arranged to surround at least a portion of the side surface 2 of the electrode assembly and at least a portion of one end 3 of the electrode assembly perpendicular to the winding axis, is configured to include a hole 11 formed in the central portion of one end of the electrode assembly perpendicular to the winding axis. The tube structure 10 can be configured to be used for insulation of the portion where the positive electrode uncoated portion 6 and the positive electrode current collector plate 7 are exposed and therefore in contact with the battery can 31 on the side surface 2 of the electrode assembly and one end 3 of the electrode assembly perpendicular to the winding axis. In addition, compared with the insulating tape, there is no problem of wrinkles or bulges, which makes it possible to improve the insulation quality, shorten the cycle time required to produce a product, and improve the processing capacity by replacing the tape process. Therefore, it is easy to insert into the battery can and easy to rework, which is also conducive to cost saving.

[0075] Reference Figure 1 (b), according to another exemplary embodiment of the present invention, the tube structure 10 may be provided to surround at least a portion of one end portion 3 of the electrode assembly perpendicular to the winding axis, so as to have a hole 11 formed in the central portion of the one end portion, and to surround the entire side surface 2 of the electrode assembly instead of a portion thereof. Therefore, the tube structure 10 may be provided for insulation of the portion where the positive electrode uncoated portion 6 and the positive electrode current collector plate 7 are exposed and thus contact the battery can 31 on the side surface 2 of the electrode assembly and the one end portion 3 of the electrode assembly perpendicular to the winding axis. This is advantageous in terms of process because the tube structure can replace the role of the fixing tape that fixes the winding core 20 before insertion into the battery can 31.

[0076] In an exemplary embodiment of the present invention, the tube structure is configured to include a hole formed in a central portion of one end portion of the electrode assembly perpendicular to the winding axis.

[0077] The hole formed in the central portion of one end portion 3 of the electrode assembly perpendicular to the winding axis refers to a hole formed from the central point of a circle which is a cross section of the electrode assembly perpendicular to the winding axis.

[0078] Figure 2 is a view schematically showing a structure of a secondary battery including a winding core according to an exemplary embodiment of the present invention.

[0079] according to Figure 2 As will be discussed below, a secondary battery according to an exemplary embodiment of the present invention is a secondary battery 30 including a winding core 20 according to an exemplary embodiment of the present invention; and a battery can 31 configured to accommodate the winding core 20, wherein the battery can 31 includes an electrode terminal 100 riveted via a through hole 300 formed in a bottom 200 of the battery can, and a gasket 400 disposed between the electrode terminal 100 and an outer diameter portion of the through hole 300.

[0080] In the electrode assembly, the positive current collector plate 7 welded to the positive electrode uncoated portion 6 may be electrically connected to the electrode terminal 100 riveted via a through hole 300 formed in the bottom 200 of the battery can. To this end, the positive current collector plate 7 and the riveted electrode terminal 100 should be welded together and may be electrically connected via a hole 11 formed in the center portion of one end portion 3 of the electrode assembly perpendicular to the winding axis disposed in the tube structure 10. In addition, the exposed positive electrode uncoated portion 6 and the positive current collector plate 7 of the electrode assembly 1 in contact with the remaining battery can 31 may be insulated by the tube structure 10. This allows the current applied to the battery to be stably increased, achieving high energy density, and providing a high-capacity, high-power secondary battery.

[0081] Figure 3 are photographs showing, in a winding core with an insulating tape attached according to a comparative example of the present invention, (a) a process, (b) one end portion of an electrode assembly perpendicular to the winding axis, (c) the insulating tape in the form of wrinkles and ridges, and (d) the insulating tape falling off when inserted into a battery can, and Figure 4 are photographs showing (a) a process, (b) one end portion of an electrode assembly perpendicular to a winding axis, and (c) a side surface of an electrode assembly in a tube structure of a small cylindrical secondary battery having a form factor of 21700 according to a comparative example of the present invention.

[0082] Reference Figure 3 (a) to Figure 3In (d), after the positive current collector plate of the electrode assembly is laser welded to the positive uncoated portion, an insulating tape may be attached to the exposed positive uncoated portion and the positive current collector plate to insulate the positive uncoated portion and the portion of the positive current collector plate that contacts the battery can. Pasting the insulating tape is disadvantageous in terms of appearance quality and workmanship because when the winding core is inserted into the battery can, the insulating tape may fall off due to wrinkles or bulges of the insulating tape.

[0083] In addition, refer to Figure 4 (a) to Figure 4 In (c), the tube structure of the small cylindrical secondary battery with a shape factor of 21700 is arranged outside the battery can, and therefore, the effect of improving insulation quality and facilitating insertion into the battery can achieved by the tube structure arranged in the electrode assembly according to an exemplary embodiment of the present invention cannot be achieved.

[0084] An exemplary embodiment of the present invention provides a winding core, wherein at least one of the positive electrode and the negative electrode includes a current collector and an electrode active material layer disposed on the current collector, the current collector includes an uncoated portion on which the electrode active material layer is not disposed, at least a portion of the uncoated portion is exposed to a side surface of the electrode assembly, and a tube structure is disposed to surround the uncoated portion on the side surface of the electrode assembly.

[0085] For high capacity and high output of the secondary battery, the positive electrode uncoated portion and the negative electrode uncoated portion are respectively located at one end of the electrode assembly perpendicular to the winding axis and the other end which is the opposite surface of the one end, thereby reducing the internal resistance of the secondary battery and increasing the energy density.

[0086] In this case, the tube structure is provided to surround the uncoated portion on the side surface of the electrode assembly, so that the problem of wrinkles or bulges does not occur compared with the insulating tape, so that the insulation quality can be improved, the takt time required to produce one product can be shortened, and the processing capacity can be improved. In addition, it is easy to insert into the battery can and easy to rework, which can also contribute to cost saving.

[0087] An exemplary embodiment of the present invention provides a winding core further comprising a current collector plate disposed at an end of the electrode assembly perpendicular to the winding axis, wherein the current collector plate is located between the tube structure and the electrode assembly, or at the other end of the electrode assembly perpendicular to the winding axis.

[0088] Among the current collector plates disposed at the end of the electrode assembly perpendicular to the winding axis, the current collector plate located between the tube structure and the electrode assembly may be a positive current collector plate, and the current collector plate located at the other end of the electrode assembly perpendicular to the winding axis may be a negative current collector plate.

[0089] For high capacity and high output of the secondary battery, the positive electrode uncoated portion and the negative electrode uncoated portion are respectively located at one end of the electrode assembly perpendicular to the winding axis and the other end as the opposite surface to the one end, and the current collector plate is welded to the uncoated portion, thereby improving the current collection efficiency. This makes it possible to reduce the internal resistance of the secondary battery and increase the energy density.

[0090] Including a tube structure disposed to surround a current collector plate on a side surface of an electrode assembly makes it possible to improve insulation quality and handling capability and facilitate insertion of the electrode assembly into a battery can.

[0091] An exemplary embodiment of the present invention provides an electrode assembly in which the tube structure is not provided to extend to the other end portion opposite to one end portion of the electrode assembly perpendicular to the winding axis.

[0092] In the tube structure, the electrode assembly may be exposed on the entire surface of the other end opposite to the one end of the electrode assembly perpendicular to the winding axis. That is, the tube structure may not be provided at the other end opposite to the one end of the electrode assembly perpendicular to the winding axis.

[0093] Reference Figure 1 (a) and Figure 1 In (b), the tube structure 10 can be configured to extend to surround at least a portion of the side surface 2 of the electrode assembly and at least a portion of one end 3 of the electrode assembly perpendicular to the winding axis, but is not configured to extend to the other end 4 opposite to the one end 3 of the electrode assembly perpendicular to the winding axis.

[0094] The other end 4 opposite to the end 3 of the electrode assembly perpendicular to the winding axis may be an opposite surface of the one end 3 of the electrode assembly perpendicular to the winding axis.

[0095] As described above, the positive electrode uncoated portion and the negative electrode uncoated portion may be located at one end 3 of the electrode assembly perpendicular to the winding axis and the other end 4 as the opposite surface to the one end, respectively, and the current collector plate may be welded to the uncoated portion, thereby being able to improve the current collection efficiency. If the tube structure 10 is provided to extend to the other end 4 opposite to the one end 3 of the electrode assembly perpendicular to the winding axis, the negative electrode uncoated portion of the electrode assembly 1 and the negative electrode current collector plate may not be electrically connected to the battery can, or the resistance may increase, resulting in a decrease in energy density.

[0096] In an exemplary embodiment of the present invention, the tube structure is configured to extend from the outer peripheral surface of one end of the electrode assembly perpendicular to the winding axis to the hole, and the area of ​​the tube structure arranged at one end of the electrode assembly perpendicular to the winding axis is less than 50% relative to 100% of the area of ​​one end of the electrode assembly perpendicular to the winding axis.

[0097] Reference Figure 1 (a) and Figure 1 In (b), the area 12A of the tube structure arranged at one end of the electrode assembly perpendicular to the winding axis is less than 45%, less than 40%, less than 35%, less than 30%, less than 25%, or less than 20% relative to 100% of the area of ​​one end of the electrode assembly perpendicular to the winding axis.

[0098] The area 12A of the tube structure provided at one end of the electrode assembly perpendicular to the winding axis may be 5% or more, or 10% or more relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding axis.

[0099] According to an exemplary embodiment, the area of ​​the tube structure provided at one end of the electrode assembly perpendicular to the winding axis may be within a range in which the area does not affect the subsequent assembly process, and may not be limited to the above range. The area of ​​one end of the electrode assembly perpendicular to the winding axis may be the sum of the area 12A of the tube structure provided at one end portion of the electrode assembly perpendicular to the winding axis and the area of ​​the hole. The area of ​​the hole may be 50% or more relative to the area of ​​one end of the electrode assembly perpendicular to the winding axis.

[0100] The area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding axis may be 50% or more, 55% or more, or 60% or more relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding axis. The area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding axis may be 95% or less, or 90% or less relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding axis.

[0101] According to an exemplary embodiment, the area 12A of the tube structure provided at one end of the electrode assembly perpendicular to the winding axis may be 5% to 50%, 10% to 50%, 10% to 40%, 10% to 30%, or 10% to 20% relative to 100% of the area of ​​one end of the electrode assembly perpendicular to the winding axis.

[0102] According to exemplary embodiments, the area of ​​the hole provided at one end of the electrode assembly perpendicular to the winding axis may be 50% to 95%, 50% to 90%, 60% to 90%, 70% to 90%, or 80% to 90% relative to 100% of the area of ​​one end of the electrode assembly perpendicular to the winding axis.

[0103] When the above range is satisfied, the tube structure 10 can insulate the positive electrode uncoated portion and the positive electrode current collector plate 7 at one end portion 3 of the electrode assembly perpendicular to the winding axis and thus a portion contacting the battery can, and improve handling capability.

[0104] In an exemplary embodiment of the present invention, the tube structure is configured to extend from the outer peripheral surface of one end of the electrode assembly perpendicular to the winding axis to the hole, and the width of the tube structure arranged at one end of the electrode assembly perpendicular to the winding axis is less than 30% relative to 100% of the diameter of one end of the electrode assembly perpendicular to the winding axis.

[0105] Reference Figure 1 (a) and Figure 1 In (b), the width 12W of the tube structure provided at one end 3 of the electrode assembly perpendicular to the winding axis may be 27% or less, 24% or less, 21% or less, or 18% or less relative to 100% of the diameter of the one end 3 of the electrode assembly perpendicular to the winding axis. The width 12W of the tube structure provided at one end 3 of the electrode assembly perpendicular to the winding axis may be 9% or more, 12% or more, or 15% or more relative to 100% of the diameter of the one end 3 of the electrode assembly perpendicular to the winding axis.

[0106] According to exemplary embodiments, the width of the tube structure provided at one end portion of the electrode assembly perpendicular to the winding axis may be within a range in which the width does not affect a subsequent assembly process, and may not be limited to the above range.

[0107] When the above range is satisfied, the tube structure 10 can insulate the positive electrode uncoated portion and the positive electrode current collector plate 7 at one end portion 3 of the electrode assembly perpendicular to the winding axis and thus a portion contacting the battery can, and improve handling capability.

[0108] In an exemplary embodiment of the present invention, a roll core is provided wherein the tube structure comprises a stretchable material.

[0109] When the tube structure includes a stretchable material, even if the electrode assembly expands to a certain extent due to repeated charge and discharge in an electrolyte solution, a tube structure suitable for its shape can be provided, compared to the case where the tube structure includes a non-stretchable material.

[0110] The case including a non-stretchable material may refer to the case including a material having little or no stretchability.

[0111] According to another exemplary embodiment of the present invention, a winding core can be provided in which a tube structure has insulating, flame retardant and heat resistant properties. By including the above properties, the tube structure does not experience problems of wrinkling or bulging compared to an insulating tape, so that the insulation quality can be improved, the cycle time required to produce one product can be shortened, and the processing capacity can be improved.

[0112] In an exemplary embodiment of the present invention, the pipe structure includes a polyvinyl chloride based (PVC+EVE) compound. However, the pipe structure is not limited thereto as long as it has insulating properties.

[0113] Due to this compound, the tube structure can have an insulating effect and an expansion effect. Specifically, unlike PET, which is generally used for ordinary tube structures, the inclusion of the above compound allows the tube structure to shrink at room temperature. PET can shrink by heat shrinking at high temperatures above 80°C.

[0114] In an exemplary embodiment of the present invention, a winding core is provided in which the tube structure shrinks at room temperature.

[0115] The room temperature may be a temperature selected from 20°C to 27°C (eg, 22°C to 26°C, 24°C to 26°C, or 25°C).

[0116] Compared with a tube structure that is heat-shrunk at a high temperature of more than 80°C, shrinking the tube structure at room temperature can shorten the cycle time required to produce one product, thereby improving processing capabilities and facilitating rework, which is also conducive to cost savings. That is, since the tube structure shrinks at room temperature, the tube heating process of applying heat to the tube structure can be omitted, and unlike the process of the prior art, the tube structure can be realized with a simple process.

[0117] The tube structure may include a polyvinyl chloride (PVC+EVE) compound and shrink at room temperature.

[0118] In an exemplary embodiment of the present invention, a winding core in which a shrinkage rate of a tube structure at room temperature is 30% or less is provided.

[0119] The shrinkage rate at room temperature refers to the degree of shrinkage relative to 100% of the tube structure at room temperature.

[0120] The shrinkage rate of the tube structure at room temperature may be less than 28%, less than 26%, less than 24%, less than 22%, or less than 20%. The shrinkage rate of the tube structure at room temperature may be greater than 3%, greater than 5%, greater than 7%, greater than 9%, or greater than 11%.

[0121] When the above range is satisfied, the tube structure shrinks at room temperature compared to a tube structure heat-shrunk at high temperature, thereby improving processing capacity by shortening the tact time required to produce one product and facilitating rework, which is also conducive to cost saving.

[0122] In an exemplary embodiment of the present invention, a winding core is provided wherein the tube structure comprises an insulating material.

[0123] The tube structure may have a dielectric strength of 14KV / mm and a dielectric constant of 9.0. Here, the dielectric strength may be measured according to the KSC2105 test method, and the dielectric constant may be measured according to the AS1977 test method.

[0124] Within the above range, the tube structure is provided around the side surface of the electrode assembly and one end portion of the electrode assembly perpendicular to the winding axis where the positive electrode uncoated portion and the positive current collector plate are exposed and can contact the battery can, thereby improving insulation quality.

[0125] Since the tube structure provided to surround the side surface of the electrode assembly and one end of the electrode assembly perpendicular to the winding axis includes an insulating material, there is no problem of wrinkles or bulges compared to the case where an insulating tape is attached, so that the insulation quality can be improved, the time required to produce the product can be shortened, and the processing capacity can be improved. In addition, it is easy to insert into the battery can and easy to rework, which is also conducive to cost saving.

[0126] In an exemplary embodiment of the present invention, a winding core is provided in which the tube structure has a thickness of 3 mm or less.

[0127] The thickness of the tube structure may be 2.5 mm or less, 2 mm or less, 1.5 mm or less, or 1 mm or less. The thickness of the tube structure may be 0.04 mm or more, or 0.05 mm or more.

[0128] When the above range is satisfied, it may be advantageous to secure the capacity of the winding core including the tube structure of the present invention.

[0129] An exemplary embodiment of the present invention provides a secondary battery, which includes: a winding core according to the above exemplary embodiment; and a battery can configured to accommodate the winding core, wherein the battery can includes an electrode terminal riveted via a through hole formed in the bottom of the battery can, and a gasket arranged between the electrode terminal and the outer diameter portion of the through hole.

[0130] Reference Figure 2 , shows a secondary battery 30 having a structure in which both a positive electrode terminal and a negative electrode terminal are electrically connected at a bottom 200 of a battery can on opposite sides of an opening portion on one side of a battery can 31 .

[0131] The secondary battery 30 includes an electrode terminal 100 riveted via a through hole 300 formed in the bottom 200 of the battery can and a gasket 400 disposed between the electrode terminal and an outer diameter portion of the through hole 300 to insulate the electrode terminal 100 from the battery can 31 .

[0132] The secondary battery may be a cylindrical secondary battery in which a negative terminal is disposed on the bottom 200 of the battery can and the riveted electrode terminal 100 may be a positive terminal.

[0133] The positive current collector plate 7 welded to the positive electrode uncoated portion 6 in the electrode assembly 1 can be electrically connected to the electrode terminal 100 riveted via the through hole 300 formed in the bottom 200 of the battery can, and the exposed positive electrode uncoated portion 6 and the positive current collector plate 7 of the electrode assembly 1 in contact with the battery can 31 can be insulated by the tube structure 10. This allows the current applied to the battery to be stably increased, achieving high energy density, and providing a high-capacity, high-power secondary battery.

[0134] In an exemplary embodiment of the present invention, a secondary battery is provided, wherein an electrode terminal includes: a main body portion inserted into a through hole; an outer flange portion extending along an outer surface from a periphery of one side of the main body portion exposed through an outer surface of a bottom portion; an inner flange portion extending toward an inner surface from a periphery of another side of the main body portion exposed through an inner surface of a bottom portion; and a flat portion disposed on an inner side of the inner flange portion.

[0135] The battery can according to the exemplary embodiment of the present invention may include an electrode terminal riveted to the bottom of the battery can. For example, the electrode terminal riveted to the bottom of the battery can may have a riveting structure.

[0136] Reference Figure 2 , the riveted structure of the electrode terminal 100 according to the exemplary embodiment may include a cylindrical battery can 31 opened at one side, an electrode terminal riveted through a through hole 300 formed in the bottom 200 of the battery can, and a gasket 400 disposed between the electrode terminal 100 and the outer diameter portion of the through hole 300.

[0137] The battery can 31 is made of a conductive metal material. In one example, the battery can 31 may be made of a steel material, but the present invention is not limited thereto.

[0138] The electrode terminal 100 is made of a conductive metal material. In one example, the electrode terminal 100 may be made of aluminum, but the present invention is not limited thereto.

[0139] The gasket 400 may be made of a polymer resin having insulating and elastic properties. In one example, the gasket 400 may be made of polypropylene, polybutylene terephthalate, polyvinyl fluoride, etc., but the present invention is not limited thereto.

[0140] Preferably, the electrode terminal 100 may include a main body portion 110 inserted into the through hole 300, an outer flange portion 120 extending along the outer surface from the periphery of one side of the main body portion 110 exposed through the outer surface of the bottom 200 of the battery can, an inner flange portion 130 extending toward the inner surface from the periphery of the other side of the main body portion 110 exposed through the inner surface of the bottom 200 of the battery can, and a flat portion 140 arranged on the inner side of the inner flange portion 130.

[0141] Preferably, the flat portion 140 and the inner surface of the bottom 200 of the battery can may be parallel to each other. Here, "parallel" means substantially parallel when observed with the naked eye.

[0142] According to an exemplary embodiment of the present invention, a caulking jig that moves up and down may be used to form a riveted structure of the electrode terminal 100. First, a preform (not shown) of the electrode terminal 100 is inserted into the through hole 300 formed at the bottom of the battery can, and the gasket 400 is interposed therebetween. The preform refers to the electrode terminal before riveting.

[0143] Next, a caulking jig is inserted into the inner space of the battery can. The caulking jig has grooves and protrusions corresponding to the final shape of the electrode terminal 100 on a surface facing the preform so as to form the electrode terminal 100 by riveting the preform.

[0144] Next, the caulking jig is moved downward to compression-mold the upper portion of the preform, thereby transforming the preform into the riveted electrode terminal 100 .

[0145] When the preform is pressed by the caulking jig, the portion of the gasket 400 interposed between the outer flange portion 120 and the outer surface of the battery can bottom is elastically compressed and reduced in thickness. Therefore, the sealing performance and airtightness between the riveted electrode terminal 100 and the battery can can be significantly improved.

[0146] Preferably, the gasket 400 is sufficiently compressed to ensure the desired seal strength without being physically damaged during the riveting process of the preform.

[0147] In one example, when the gasket 400 is made of polybutylene terephthalate, the gasket 400 preferably has a compression ratio of 50% or more at the point where it is compressed to its minimum thickness. The compression ratio is the ratio of the thickness change before and after compression to the thickness before compression.

[0148] In another example, when the gasket 400 is made of polyvinyl fluoride, the gasket 400 preferably has a compression rate of 60% or more at a point where it is compressed to its minimum thickness.

[0149] In another example, when the gasket 400 is made of polypropylene, the gasket 400 preferably has a compression rate of more than 60% at the point where it is compressed to its minimum thickness.

[0150] Preferably, the extrusion molding of the upper part of the preform can be performed step by step by moving the caulking jig up and down at least twice. That is, the preform can be deformed several times by gradually extruding the preform. In this case, the pressure applied to the caulking jig can be gradually increased. By doing so, the stress applied to the preform is distributed multiple times, so that the gasket 400 can be prevented from being damaged during the caulking process.

[0151] When the caulking jig is separated from the battery can after the preform is extruded using the caulking jig, as shown in FIG. Figure 2 As shown, the riveting structure of the electrode terminal 100 according to the exemplary embodiment of the present disclosure can be obtained.

[0152] According to the above exemplary embodiment, the caulking jig extrudes the upper portion of the preform by moving up and down inside the battery can. In some cases, a rotary jig used in the prior art may be used to extrusion-mold the preform.

[0153] However, the rotary jig rotates while being tilted at a predetermined angle relative to the central axis of the battery can. Therefore, a rotary jig having a large rotation radius may interfere with the inner wall of the battery can. In addition, when the depth of the battery can is large, the length of the rotary jig also becomes longer accordingly. In this case, as the rotation radius of the end of the rotary jig increases, the extrusion molding of the preform may not be performed correctly. Therefore, extrusion molding using a caulking jig is more effective than using a rotary jig.

[0154] The rivet structure of the electrode terminal 100 according to the exemplary embodiment of the present invention described above may be applied to the secondary battery 30 .

[0155] In one example, the secondary battery 30 may include a battery can 31. The battery can 31 may be cylindrical. The size of the battery may be 30 mm to 55 mm in diameter and 60 mm to 120 mm in height at each of the two ends. Preferably, the diameter × height of the circle of the cylindrical battery can 31 may be 46 mm × 60 mm, 46 mm × 80 mm, 46 mm × 90 mm, or 46 mm × 120 mm.

[0156] Preferably, the cylindrical secondary battery may be, for example, a cylindrical secondary battery having a shape factor ratio (defined as a value obtained by dividing the diameter of the cylindrical secondary battery by the height, ie, a ratio of the diameter Φ to the height H) greater than about 0.4.

[0157] Here, the form factor refers to a value representing the diameter and height of a cylindrical secondary battery. The cylindrical secondary battery according to an exemplary embodiment of the present invention may be, for example, a 46110 cell,

[0158] 48750 cells, 48110 cells, 48800 cells, 46800 cells, or 46900 cells. In the numerical value representing the shape factor, the first two digits represent the diameter of the cell, the second two digits represent the height of the cell, and the last digit 0 represents that the cross section of the cell is circular.

[0159] The secondary battery according to the exemplary embodiment of the present invention may be a cylindrical secondary battery having an approximately cylindrical shape with a diameter of approximately 46 mm, a height of approximately 110 mm, and a shape factor ratio of 0.418.

[0160] A secondary battery according to another exemplary embodiment may be a cylindrical secondary battery having a cylindrical shape with a diameter of about 48 mm, a height of about 75 mm, and a shape factor ratio of 0.640.

[0161] A secondary battery according to still another exemplary embodiment may be a cylindrical secondary battery having a cylindrical shape with a diameter of about 48 mm, a height of about 110 mm, and a shape factor ratio of 0.418.

[0162] A secondary battery according to still another exemplary embodiment may be a cylindrical secondary battery having a cylindrical shape with a diameter of about 48 mm, a height of about 80 mm, and a form factor ratio of 0.600.

[0163] A secondary battery according to still another exemplary embodiment may be a cylindrical secondary battery having a cylindrical shape with a diameter of about 46 mm, a height of about 80 mm, and a form factor ratio of 0.575.

[0164] A secondary battery according to still another exemplary embodiment may be a cylindrical secondary battery having a cylindrical shape with a diameter of about 46 mm, a height of about 90 mm, and a form factor ratio of 0.511.

[0165] In the prior art, secondary batteries having a shape factor ratio of about 0.4 or less have been used. That is, in the prior art, for example, 18650 cells, 21700 cells, etc. have been used. For the 18650 cells, the diameter is about 18 mm, the height is about 65 mm, and the shape factor ratio is 0.277. For the 21700 cells, the diameter is about 21 mm, the height is about 70 mm, and the shape factor ratio is 0.300.

[0166] According to an exemplary embodiment of the present invention, there is provided a secondary battery including a negative terminal disposed at the bottom of a battery can, the riveted electrode terminal is a positive terminal, and the positive terminal is electrically connected to one end of an electrode assembly perpendicular to a winding axis.

[0167] According to an exemplary embodiment of the present invention, there is provided a secondary battery in which the electrode assembly further includes a positive current collector plate disposed at one end portion of the electrode assembly perpendicular to the winding axis, and the positive terminal is electrically connected to the positive current collector plate.

[0168] According to an exemplary embodiment of the present invention, a secondary battery is provided in which a tube structure is provided including a hole formed in a central portion of one end portion of an electrode assembly perpendicular to a winding axis, and a positive terminal and a positive current collector plate are electrically connected to each other via the hole.

[0169] The current collector plate and the tube structure in the secondary battery according to the exemplary embodiment of the present invention are the same as the above-described current collector plate and the tube structure in the electrode assembly.

[0170] In the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may be used without limitation as long as they are active materials known in the art.

[0171] Non-limiting examples of the positive electrode active material may include common positive electrode active materials that can be used for positive electrodes of conventional electrochemical devices, and specifically, lithium manganese oxide, lithium cobalt oxide, lithium nickel oxide, lithium iron oxide, or a lithium composite oxide prepared by combining them may be used.

[0172] In one example, the positive electrode active material may include a x M y ]O 2+z An alkali metal compound represented by (A includes at least one element selected from Li, Na and K; M includes at least one element selected from Ni, Co, Mn, Ca, Mg, Al, Ti, Si, Fe, Mo, V, Zr, Zn, Cu, Al, Mo, Sc, Zr and Ru; x≥0, 1≤x+y≤2, -0.1≤z≤2; the stoichiometric coefficients of the components included in M ​​and x, y and z are selected so that the compound remains electrically neutral).

[0173] In another example, the positive electrode active material may be an alkali metal compound xLiM disclosed in US Pat. No. 6,677,082, US Pat. No. 6,680,143, etc. 1 O2-(1-x)Li2M 2 O3(M 1 including at least one element having an average oxidation state of 3; M 2 Includes at least one element having an average oxidation state of 4; 0≤x≤1).

[0174] In another example, the positive electrode active material may be a material of the general formula Li a M 1 x Fe1-x M 2 y P 1-y M 3 z O 4-z (M 1 comprises at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, Al, Mg, and Al; M 2 comprises at least one element selected from Ti, Si, Mn, Co, Fe, V, Cr, Mo, Ni, Nd, A1, Mg, Al, As, Sb, Si, Ge, V, and S; M 3 comprises an element in the halogen group, optionally including F; 0 < a ≤ 2, 0 ≤ x ≤ 1, 0 ≤ y < 1, 0 ≤ z < 1; M is selected 1 、M 2 and M 3 such that the stoichiometric coefficients of the components included in and a, x, y, z are selected such that the compound remains electrically neutral) or a lithium metal phosphate represented by Li3M2(PO4)3 [M comprises at least one element selected from Ti, Si, Mn, Fe, Co, V, Cr, Mo, Ni, Al, Mg, and Al].

[0175] Preferably, the positive electrode active material may include primary particles and / or secondary particles in which the primary particles are aggregated.

[0176] Non-limiting examples of the negative electrode active material may include common negative electrode active materials that can be used for the negative electrode of an electrochemical device in the prior art, and in particular, lithium adsorption materials such as lithium metal or lithium alloys, carbon, petroleum coke, activated carbon, graphite, or other carbonaceous materials may be used.

[0177] In one example, carbon materials, lithium metal or lithium metal compounds, silicon or silicon compounds, tin or tin compounds, etc. may be used as the negative electrode active material. Metal oxides such as TiO2 and SnO2 with a potential less than 2V may also be used as the negative electrode active material. As the carbon material, both low-crystalline carbon and high-crystalline carbon may be used.

[0178] Non-limiting examples of the positive electrode current collector include foils made of aluminum, nickel, or a combination thereof, while non-limiting examples of the negative electrode current collector include foils made of copper, gold, nickel, or a copper alloy or a combination thereof.

[0179] For the separator, a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer (such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, or an ethylene / methacrylate copolymer) can be used alone, or a structure obtained by laminating polymers can be used. In another example, for the separator, a typical porous nonwoven fabric (for example, a nonwoven fabric formed of a high melting point glass fiber, a polyethylene terephthalate fiber, etc.) can be used.

[0180] At least one surface of the separator may include a coating layer of inorganic particles.

[0181] Furthermore, it is also feasible that the separator itself is made of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder so that there is a gap volume between adjacent particles.

[0182] The inorganic particles may be made of an inorganic material having a dielectric constant of 5 or more. Non-limiting examples of the inorganic particles may include a material selected from the group consisting of Pb(Zr,Ti)O3(PZT), Pb 1-x La x Zr 1-y Ti y O3(PLZT), PB(Mg3Nb 2 / 3 )At least one material from the group consisting of O3-PbTiO3 (PMN-PT), BaTiO3, hafnium (HfO2), SrTiO3, TiO2, Al2O3, ZrO2, SnO2, CeO2, MgO, CaO, ZnO and Y2O3.

[0183] The electrolyte may be a + B-like structure. Here, A + including alkali metal cations (such as Li + 、Na + and K + or a combination thereof). B- includes any one or more anions selected from the group consisting of: F - , Cl - Br - ,I - 、NO3 - 、N(CN)2 - 、BF4 - 、ClO4 - 、AlO4 - 、AlCl4 - PF6 - 、SbF6 - 、AsF6 - 、BF2C2O4 - , BC4O8- 、(CF3)2PF4 - 、(CF3)3PF3 - 、(CF3)4PF2 - 、(CF3)5PF - 、(CF3)6P - CF3SO3 - 、C4F9SO3 - CF3CF2SO3 - 、(CF3SO2)2N - 、(FSO2)2N - CF3CF2(CF3)2CO - 、(CF3SO2)2CH - 、(SF5)3C - 、(CF3SO2)3C - CF3(CF2)7SO3 - CF3CO2 - 、CH3CO2 - 、SCN - and (CF3CF2SO2)2N - .

[0184] The electrolyte can also be used by dissolving it in an organic solvent. As the organic solvent, propylene carbonate (PC), ethylene carbonate (EC), diethyl carbonate (DEC), dimethyl carbonate (DMC), dipropyl carbonate (DPC), dimethyl sulfoxide, acetonitrile, dimethoxyethane, diethoxyethane, tetrahydrofuran, N-methyl-2-pyrrolidone (NMP), ethyl methyl carbonate (EMC), γ-butyrolactone or a mixture thereof can be used.

[0185] Still another exemplary embodiment of the present invention provides a battery pack including at least one secondary battery according to the above exemplary embodiment.

[0186] The cylindrical secondary battery according to the above exemplary embodiment may be used to manufacture a battery pack.

[0187] Figure 5 is a view showing a schematic configuration of a battery pack including a secondary battery according to an exemplary embodiment of the present invention.

[0188] Reference Figure 5 , a battery pack 40 according to an exemplary embodiment of the present invention includes an assembly in which a cylindrical secondary battery is electrically connected, and a battery pack case 50 for accommodating the assembly. The cylindrical secondary battery is the secondary battery 30 according to the above exemplary embodiment. In the figure, for the convenience of illustration, components such as bus bars, cooling units, and external terminals for electrical connection of the cylindrical secondary battery 30 are omitted.

[0189] Yet another exemplary embodiment of the present invention provides a vehicle including the above-mentioned at least one battery pack.

[0190] The battery pack may be mounted on a vehicle. The vehicle may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle. The vehicle may include a four-wheel vehicle or a two-wheel vehicle.

[0191] Figure 6 It is used to illustrate the Figure 5 View of the battery pack of a vehicle.

[0192] Reference Figure 6 , a vehicle 60 according to an exemplary embodiment of the present invention includes a battery pack 40 according to an exemplary embodiment of the present invention. According to the exemplary embodiment of the present invention, the vehicle operates by receiving power from the battery pack 40.

[0193] Although the present invention has been described with reference to limited exemplary embodiments and drawings, the present invention is not limited thereto, and those skilled in the art to which the present invention pertains may make various modifications and variations within the technical spirit of the present invention and the equivalent scope of the following claims.

Claims

1. A winding core, comprising: An electrode assembly having a structure in which a positive electrode, a separator and a negative electrode are stacked and wound; as well as a tube structure provided to surround at least a portion of a side surface of the electrode assembly and at least a portion of an end portion of the electrode assembly perpendicular to a winding axis, The tube structure is configured to include a hole formed in a central portion of one end portion of the electrode assembly perpendicular to the winding axis.

2. The winding core according to claim 1, wherein: At least one of the positive electrode and the negative electrode includes a current collector and an electrode active material layer disposed on the current collector, and the current collector includes an uncoated portion where the electrode active material layer is not disposed, wherein at least a portion of the uncoated portion is exposed to a side surface of the electrode assembly, and Wherein, the tube structure is disposed to surround the uncoated portion on the side surface of the electrode assembly.

3. The winding core according to claim 1, further comprising a current collector plate disposed at at least one end of the electrode assembly perpendicular to the winding axis, and in, The current collector plate is located between the tube structure and the electrode assembly, or the current collector plate is located at the other end of the electrode assembly perpendicular to the winding axis.

4. The winding core according to claim 1, wherein: The tube structure is not provided to extend to the other end portion opposite to one end portion of the electrode assembly perpendicular to the winding axis.

5. The winding core according to claim 1, wherein: The tube structure is provided to extend from an outer peripheral surface of one end portion of the electrode assembly perpendicular to the winding axis to the hole, and The area of ​​the tube structure provided at one end of the electrode assembly perpendicular to the winding axis is less than 50% relative to 100% of the area of ​​the one end of the electrode assembly perpendicular to the winding axis.

6. The winding core according to claim 1, wherein: The tube structure is provided to extend from an outer peripheral surface of one end portion of the electrode assembly perpendicular to the winding axis to the hole, and The width of the tube structure disposed at one end of the electrode assembly perpendicular to the winding axis is less than 30% relative to 100% of the diameter of the one end of the electrode assembly perpendicular to the winding axis.

7. The winding core according to claim 1, wherein: The tube structure comprises a stretchable material.

8. The winding core according to claim 1, wherein: The tube structure includes a polyvinyl chloride based (PVC+EVE) compound.

9. The winding core according to claim 1, wherein: The tube structure shrinks at room temperature.

10. The winding core according to claim 1, wherein: The shrinkage rate of the tube structure at room temperature is less than 30%.

11. The winding core according to claim 1, wherein: The tube structure comprises an insulating material.

12. The winding core according to claim 1, wherein: The tube structure has a thickness of 3 mm or less.

13. A secondary battery, comprising: The winding core according to any one of claims 1 to 12; as well as a battery can configured to accommodate the winding core, The battery can includes an electrode terminal and a gasket, the electrode terminal is riveted via a through hole formed at the bottom of the battery can, and the gasket is disposed between the electrode terminal and an outer diameter portion of the through hole.

14. The secondary battery according to claim 13, wherein The electrode terminal comprises: a main body portion, the main body portion being inserted into the through hole; an outer flange portion extending from a periphery of a side of the main body portion exposed through the outer surface of the bottom portion along the outer surface; an inner flange portion extending from a periphery of the other side of the body portion exposed through the inner surface of the bottom toward the inner surface; and A flat portion is disposed inside the inner flange portion.

15. The secondary battery according to claim 13, wherein The secondary battery includes a negative terminal provided on the bottom of the battery can, and the riveted electrode terminal is a positive terminal, and The positive terminal is electrically connected to one end of the electrode assembly that is perpendicular to the winding axis.

16. The secondary battery according to claim 15, wherein The electrode assembly further includes a positive current collector plate disposed at one end of the electrode assembly perpendicular to the winding axis, and Wherein, the positive terminal is electrically connected to the positive current collector.

17. The secondary battery according to claim 16, wherein The positive terminal and the positive current collector plate are electrically connected to each other via the holes of the tube structure.

18. A battery pack comprising at least one secondary battery according to claim 13.

19. A vehicle comprising at least one battery pack according to claim 18.

Images