Cylindrical battery cell, and battery pack and vehicle including same

Abstract

Disclosed are a cylindrical battery cell, and a battery pack and a vehicle including the same. A cylindrical battery cell according to one embodiment of the present invention comprises: an electrode assembly having a structure in which a positive electrode plate having a positive electrode tab, a negative electrode plate having a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, and in which a center hole is formed; a cylindrical battery can in which the electrode assembly is accommodated, and an electrolyte is injected into the cylindrical battery can; and an insulator having a central opening formed and provided on the negative tab side for electrical insulation, in which at least a portion of the negative tab is configured to rotate according to changes in the electrode assembly during charging and discharging.

Description

Technical Field

[0001] This application claims the priority of Korean Patent Application No. 10-2023-0104435, filed on August 9, 2023, in the Republic of Korea, the disclosure of which is incorporated herein by reference.

[0002] The present disclosure relates to a cylindrical battery cell, a battery pack, and a vehicle including the cylindrical battery cell, and more particularly, to a cylindrical battery cell that avoids short circuits by preventing the shape of an electrode assembly from collapsing, and a battery pack and a vehicle including the cylindrical battery cell. Background Art

[0003] Secondary batteries are easily applicable according to product groups and have electrical characteristics such as high energy density, and are generally used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) driven by an electric drive source, as well as portable devices.

[0004] These secondary batteries are attracting attention as new energy sources for improving eco-friendliness and energy efficiency because their main advantages are a significant reduction in the use of fossil fuels and another advantage is that they do not produce by-products generated by energy use.

[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 the unit secondary battery cell is about 2.5V to 4.5V.

[0006] Therefore, when a higher output voltage is required, a battery module or a battery pack is constructed by connecting a plurality of battery cells in series. In addition, according to the required charge / discharge capacity, a plurality of battery cells may be connected in parallel to construct a battery module or a battery pack. Therefore, the number of battery cells included in the battery module or the battery pack and their electrical connection types can be set in various ways according to at least one of the required output voltage or charge / discharge capacity.

[0007] Meanwhile, as types of secondary battery cells, cylindrical battery cells, prismatic battery cells, and pouch-type battery cells are known. In the case of a cylindrical battery cell, a separator as an insulator is interposed between a positive electrode plate and a negative electrode plate, and it is wound to form a wound-type electrode assembly, and then the wound-type electrode assembly and an electrolyte are inserted into a battery can to form a battery.

[0008] Figure 1 is a diagram illustrating changes in the lengths of two side plates and a negative electrode plate of an electrode assembly when a cylindrical battery cell is repeatedly charged and discharged.

[0009] Generally, if a cylindrical battery cell is repeatedly charged and discharged, the positive electrode plate 2 or the negative electrode plate 4 of the electrode assembly 1 repeatedly contracts and relaxes, causing the length of the positive electrode plate 2 or the negative electrode plate 4 to increase.

[0010] However, since the electrode assembly 1 is stored inside a cylindrical battery can ( Figure 1 not shown herein) (e.g., made of metal), even if the length of the positive electrode plate 2 or the negative electrode plate 4 increases, it cannot be deformed outside the battery can.

[0011] Therefore, as Figure 1 shown, the positive electrode plate 2, the separator 3, or the negative electrode plate 4 is deformed toward the center of the electrode assembly 1. However, if the positive electrode plate 2, the separator 3, or the negative electrode plate 4 is folded toward the center of the electrode assembly 1 such that the shape of the electrode assembly 1 collapses, a short circuit may occur inside the battery, which may cause stability problems. SUMMARY OF THE INVENTION

[0012] TECHNICAL PROBLEM

[0013] The present disclosure is designed to solve the problems of the prior art, and thus, the present disclosure aims to provide a cylindrical battery cell capable of preventing the shape of an electrode assembly from collapsing during repeated charging and discharging of a cylindrical battery cell, as well as a battery pack and a vehicle including the cylindrical battery cell.

[0014] In addition, the present disclosure provides a cylindrical battery cell capable of preventing a short circuit of the cylindrical battery cell according to the present disclosure, as well as a battery pack and a vehicle including the cylindrical battery cell.

[0015] However, the technical problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art will clearly understand other problems not mentioned above from the description of the present invention described below.

[0016] TECHNICAL SOLUTION

[0017] According to an aspect of the present disclosure, there is provided a cylindrical battery cell including: an electrode assembly having a structure in which a positive electrode plate provided with a positive electrode tab, a negative electrode plate provided with a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, and a central hole is formed in the electrode assembly; a cylindrical battery can configured to store the electrode assembly and in which an electrolyte is injected; and an insulator having a central opening formed therein and disposed on the negative electrode tab side to be coupled to the electrode assembly, wherein at least a part of the negative electrode tab is configured to rotate according to changes in the electrode assembly during charging and discharging.

[0018] In an embodiment, the negative electrode tab may include: a first negative electrode tab fixed to the battery can; a second negative electrode tab positioned in the central hole of the electrode assembly, the second negative electrode tab being coupled to the electrode assembly and configured to rotate relative to the first negative electrode tab; and a coupling shaft coupled to the first negative electrode tab and the second negative electrode tab such that the second negative electrode tab can rotate.

[0019] In an embodiment, the second negative electrode tab may rotate inside the central opening of the insulator.

[0020] In an embodiment, the second negative electrode tab may rotate as the length of at least one of the positive and negative plates increases due to charging and discharging.

[0021] In an embodiment, the first negative electrode tab may include: a horizontal fixed tab formed in the horizontal direction based on the arrangement state of the battery can; and a vertical fixed tab configured to extend and bend from the horizontal fixed tab and positioned between the outermost side of the electrode assembly and the battery can.

[0022] In an embodiment, the second negative electrode tab may include: a horizontal rotating tab formed in the horizontal direction based on the arrangement state of the battery can; and a vertical rotating tab configured to extend and bend from the horizontal rotating tab and coupled to the electrode assembly in the central hole of the electrode assembly.

[0023] In an embodiment, an inner groove may be formed in the inner portion of the second negative electrode tab, and an outer protrusion may be formed on the outer surface of the coupling shaft so as to contact the inner groove and move only in one direction along the inner groove.

[0024] In an embodiment, the inner groove may include: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to meet the first line, wherein the inclination angles of the first line and the second line may be different from each other.

[0025] In an embodiment, the inner groove may include: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to meet the first line, wherein the lengths of the first line and the second line may be different from each other.

[0026] In an embodiment, an inner groove may be formed in the inner portion of the central opening of the insulator, and the second negative electrode tab may be configured to contact the inner groove and move only in one direction along the inner groove.

[0027] In an embodiment, the inner groove may include: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to connect with the first line, wherein the inclination angle of the first line and the inclination angle of the second line may be different from each other.

[0028] In an embodiment, the inner groove may include: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to connect with the first line, wherein the length of the first line and the length of the second line may be different from each other.

[0029] According to another aspect of the present disclosure, a battery pack including at least one of the above-described cylindrical battery cells may be provided, and a vehicle including at least one of the above-described cylindrical battery cells may be provided.

[0030] Advantageous Effects

[0031] Embodiments of the present disclosure have the effect of preventing the shape collapse of the electrode assembly during repeated charging and discharging of the cylindrical battery cell by configuring at least a part of the negative electrode tab to be rotatable.

[0032] In addition, there is also an effect of preventing a short circuit from occurring in the cylindrical battery cell according to the present disclosure.

[0033] However, the effects obtainable in the present disclosure are not limited to the above effects, and those skilled in the art will clearly understand other effects not mentioned above from the description of the present invention described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 is a diagram illustrating changes in the lengths of two side plates and a negative electrode plate of an electrode assembly when repeatedly charging and discharging a conventional cylindrical battery cell.

[0035] Figure 2 is a cross-sectional view of a cylindrical battery cell according to a first embodiment of the present disclosure.

[0036] Figure 3 is a schematic perspective view illustrating a coupling shaft of a first negative electrode tab and a second negative electrode tab coupled to a negative electrode tab in a cylindrical battery cell according to a first embodiment of the present disclosure.

[0037] Figure 4 is a diagram illustrating Figure 3 the state in which the first negative electrode tab in the negative electrode tab rotates relative to the second negative electrode tab.

[0038] Figure 5Schematic perspective view of a first negative tab and a second negative tab of a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure.

[0039] Figure 6 Schematic perspective view of a coupling shaft of a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure.

[0040] Figure 7 Schematic perspective view of a coupling shaft of a first negative tab and a second negative tab coupled to a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure.

[0041] Figure 8 View showing a state in which a first negative tab of a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure rotates relative to a second negative tab within a central opening of an insulator.

[0042] Figure 9 View showing an insulator in which an inner groove is formed in a central opening of a cylindrical battery cell according to a third embodiment of the present disclosure.

[0043] Figure 10 Schematic perspective view showing a state in which a negative tab is coupled to an inner groove of a central opening of an insulator in a cylindrical battery cell according to a third embodiment of the present disclosure.

[0044] Figure 11 View showing where Figure 10 a first negative tab of the negative tab rotates relative to a second negative tab.

[0045] Figure 12 View showing according to Figure 9 a modified embodiment of the insulator of

[0046] Figure 13 View schematically showing a configuration of a battery pack including a cylindrical battery cell according to various embodiments of the present disclosure.

[0047] Figure 14 View showing a vehicle including a battery pack according to various embodiments of the present disclosure. Detailed Description

[0048] Hereinafter, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be construed as limited to the general meaning and dictionary meaning, but should be interpreted based on the meaning and concept corresponding to the technical aspects of the present disclosure on the basis of the principle that allows the inventor to appropriately define the terms for the best explanation. Therefore, the configurations presented in the embodiments of the present specification and the drawings only indicate the most preferred embodiments of the present disclosure and do not represent all the technical concepts of the present disclosure. Therefore, it should be understood that various equivalent replacements and modifications can be made to the present application when submitting the present application.

[0049] The dimensions of the corresponding elements or specific parts of each element shown in the drawings are exaggerated, omitted, or simplified for ease of their explanation and clarification. Therefore, the dimensions of the corresponding elements do not fully reflect their actual dimensions. Descriptions of related known functions or configurations that may obscure the subject matter of the present disclosure will be omitted.

[0050] The expression that "one element is 'coupled' or 'fastened' to another element" should be understood that the elements can be directly coupled or fastened to each other, and the elements can be indirectly coupled or fastened to each other through another element.

[0051] Figure 2 is a cross-sectional view of a cylindrical battery cell according to a first embodiment of the present disclosure, Figure 3 is a schematic perspective view of a coupling shaft of a first negative electrode tab and a second negative electrode tab coupled to the negative electrode tab in the cylindrical battery cell according to the first embodiment of the present disclosure, and Figure 4 is a view illustrating where Figure 3 the first negative electrode tab in the negative electrode tab rotates relative to the second negative electrode tab.

[0052] Referring to Figure 2 , the cylindrical battery cell 10 according to the first embodiment of the present disclosure includes an electrode assembly 100, a battery can 200, and an insulator 400.

[0053] Referring to Figure 2 , the electrode assembly 100 has the following structure: a positive electrode plate 110 provided with a positive electrode tab 500, a negative electrode plate 120 provided with a negative electrode tab 600, and a separator 130 interposed between the positive electrode plate 110 and the negative electrode plate 120 are wound in one direction. In addition, a central hole 140 may be formed at the center of the electrode assembly 100 as a wound member.

[0054] For example, the electrode assembly 100 can be manufactured by winding a laminate obtained by sequentially stacking the negative electrode plate 120, the separator 130, the positive electrode plate 110, and the separator 130 at least once. Here, the positive electrode plate 110 and the negative electrode plate 120 may be formed in a sheet shape.

[0055] That is to say, the electrode assembly 100 applied to this embodiment may be a wound electrode assembly 100. In this case, an additional separator (not shown) may be provided on the outer surface of the electrode assembly 100 for insulation from the battery can 200. That is to say, the electrode assembly 100 may have a wound structure known in the prior art, but is not limited thereto.

[0056] The positive electrode plate 110 has positive electrode active material applied on one or both of its sides. Herein, the positive electrode plate 110 is provided with a positive electrode tab 500. In addition, the negative electrode plate 120 has negative electrode active material applied to one or both of its sides. Herein, the negative electrode plate 120 is provided with a negative electrode tab 600. The negative electrode tab 600 will be described in more detail later.

[0057] In addition, any active material known in the art may be used for the positive electrode active material coated on the positive electrode plate 110 and the negative electrode active material coated on the negative electrode plate 120, but is not limited thereto.

[0058] The separator 130 may be configured as a single porous polymer film or as a stack thereof, such as a porous polymer film made of a polyolefin polymer, such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc.

[0059] As another example, conventional porous nonwoven fabrics, such as nonwoven fabrics made of high melting point glass fibers, polyethylene terephthalate fibers, etc., may be used for the separator 130.

[0060] The separator 130 may include a coating of inorganic particles on at least one of its surfaces. In addition, the separator 130 itself may be formed of a coating of inorganic particles. The particles constituting the coating may have the following structure: they are bound to an adhesive such that there is an interstitial volume between adjacent particles.

[0061] Refer to Figure 2 , the electrode assembly 100 is stored in the battery can 200 and an electrolyte is injected into the battery can 200. For example, the battery can 200 may be formed in a cylindrical shape such that the electrode assembly 100 is stored inside the battery can 200 and can be electrically connected to the negative electrode plate 120 of the electrode assembly 100. Accordingly, the battery can 200 may have the same polarity as the negative electrode plate 120, i.e., a negative polarity.

[0062] Herein, the diameter of the battery can 200 is formed to be larger than the diameter of the electrode assembly 100. In addition, the battery can 200 may be made of a conductive material such as metal. The battery can 200 may be made of a conductive metal, such as aluminum, steel, stainless steel, etc., but is not limited thereto.

[0063] The insulator 400 is coupled to the electrode assembly 100 for electrical insulation. In Figure 2 it, the insulator 400 is coupled to the bottom of the electrode assembly 100. Additionally, the insulator 300 is coupled to the electrode assembly 100 for electrical insulation. In Figure 2 it, the insulator 300 is coupled to the top of the electrode assembly 100.

[0064] The insulator 300 is disposed on the positive tab 500 side and connected to the electrode assembly 100, and the insulator 400 is disposed on the negative tab 600 side and connected to the electrode assembly 100. Hereinafter, for convenience of description, the insulator 400 disposed on the negative tab 600 side and connected to the electrode assembly 100 will be described. However, the description of the insulator 400 common to the insulator 300 can be applied to the insulator 300.

[0065] The insulator 400 can be formed in a shape corresponding to the cross-section of the wound electrode assembly 100. For example, if the cross-section of the wound electrode assembly 100 is circular, the shape of the insulator 400 can also be circular. Additionally, the insulator 400 has a central opening 410, for example, in a circular shape. Additionally, the insulator 300 has a central opening 310, for example, in a circular shape.

[0066] The insulator 400 can include, for example, an elastic material. Thus, when vibration or an external shock is applied to the cylindrical battery cell 10, the insulator 400 can absorb the shock while being elastically compressed and then restored to its original state. Thus, even if vibration or an external shock is applied to the battery cell, damage to the internal components of the battery cell can be minimized.

[0067] The insulator 400 can be made of a material having insulating properties. Preferably, the insulator 400 can include an insulating polymer material, but is not limited thereto. For example, the insulator 400 can be made of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polypropylene (PP).

[0068] The cylindrical battery cell 10 according to the first embodiment of the present disclosure is configured such that when, for example, the length or shape of the electrode assembly 100 changes, at least a part of the negative tab 600 rotates, thereby preventing the shape of the electrode assembly 100 from collapsing and short-circuiting of the cylindrical battery cell 10.

[0069] As described above, if the cylindrical battery cell 10 is repeatedly charged and discharged, the positive electrode plate 110 or the negative electrode plate 120 repeatedly contracts and relaxes, so that the length of the positive electrode plate 110 or the negative electrode plate 120 increases. However, since the electrode assembly 100 is stored inside the cylindrical battery can 200, even if the length of the positive electrode plate 110 or the negative electrode plate 120 increases, it cannot be deformed outside the battery can 200.

[0070] However, if at least a part of the negative electrode tab 600 is configured to rotate, then even if the length of the positive electrode plate 110 or the negative electrode plate 120 increases during charging and discharging, the positive electrode plate 110 or the negative electrode plate 120 will not fold toward the center.

[0071] That is, in Figure 1 In the case of the conventional cylindrical battery cell shown, even if the positive electrode plate 1 or the negative electrode plate 4 is stretched by force during charging and discharging, since the negative electrode tab is fixed to the battery can and cannot move, the positive electrode plate 1 or the negative electrode plate 4 will fold toward the center hole of the electrode assembly 1 at the part where the force is concentrated.

[0072] However, in the cylindrical battery cell 10 according to the first embodiment of the present disclosure, if the positive electrode plate 110 or the negative electrode plate 120 is stretched by force during charging and discharging, at least a part of the negative electrode tab 600 rotates instead of being fixed, so that the positive electrode plate 110 or the negative electrode plate 120 does not fold toward the center hole 140 of the electrode assembly 100.

[0073] That is, in the first embodiment of the present disclosure, the force generated during charging and discharging is converted into the rotational force of the negative electrode tab 600, so that the shape of the electrode assembly 100 does not collapse, thereby preventing a short circuit of the cylindrical battery cell 10.

[0074] Referring to Figure 2 and Figure 3 both, the negative electrode tab 600 may be configured to include a first negative electrode tab 610, a second negative electrode tab 620, and a coupling shaft 630.

[0075] The first negative electrode tab 610 is fixed to the battery can 200. The first negative electrode tab 610 can be fixed in various ways and can be fixed to the battery can 200 by welding, for example.

[0076] The first negative electrode tab 610 may include a horizontal fixed tab 611 and a vertical fixed tab 612.

[0077] The horizontal fixed tab 611 is formed in the horizontal direction in the arrangement state of the battery can 200. For example, in the case where the battery can 200 is arranged as Figure 2 shown, the horizontal fixed tab 611 can be arranged in the left - right direction at the bottom of the battery can 200.

[0078] In addition, the vertical fixing tab 612 can extend to be bent from the horizontal fixing tab 611 so as to be positioned between the outermost side of the electrode assembly 100 and the battery can 200. The vertical fixing tab 612 can extend to be vertically bent from the horizontal fixing tab 611, for example, but is not necessarily limited thereto.

[0079] In addition, the first negative electrode tab 610 is fixedly coupled to at least one of the bottom and the side surface of the battery can 200. That is, the horizontal fixing tab 611 can be coupled to the bottom of the battery can 200 by welding or the like, and the vertical fixing tab 612 can be coupled to the side surface of the battery can 200 by welding or the like.

[0080] The second negative electrode tab 620 is positioned in the central hole 140 of the electrode assembly 100 to be coupled to the electrode assembly 100, and is configured to rotate relative to the first negative electrode tab 610. That is, the second negative electrode tab 620 is configured to rotate about the coupling shaft 630 as the rotation axis.

[0081] In addition, since one side of the second negative electrode tab 620 is coupled to the electrode assembly 100, if a force is applied to the electrode assembly 100 due to the charging and discharging of the cylindrical battery cell 10 as the length of at least one of the positive electrode plate 110 and the negative electrode plate 120 increases, the second negative electrode tab 620 rotates by this force.

[0082] In addition, when the second negative electrode tab 620 rotates, the force applied to the electrode assembly 100 is converted into the rotational force as described above, thereby preventing the shape of the electrode assembly 100 from collapsing.

[0083] Referring to Figure 2 and Figure 3 , the second negative electrode tab 620 can be configured to rotate inside the central opening 410 of the insulator 400 (see Figure 8 in the second embodiment). That is, the diameter of the central opening 410 of the insulator 400 can be formed to be larger than the rotational diameter of the second negative electrode tab 620 so that the second negative electrode tab 620 does not interfere with the insulator 400 when rotating.

[0084] The second negative electrode tab may include a horizontal rotating tab 621 and a vertical rotating tab 622.

[0085] The horizontal rotating tab 621 is formed in the horizontal direction in the arrangement state of the battery can 200. For example, in the case where the battery can 200 is arranged as shown in Figure 2 , the horizontal rotating tab 621 can be arranged in the left - right direction at the bottom of the battery can 200.

[0086] In addition, as the length of at least one of the positive electrode plate 110 and the negative electrode plate 120 increases, the horizontal rotating tab 621 rotates together with the vertical rotating tab 622.

[0087] The vertical rotating tab 622 extends so as to be bent from the horizontal rotating tab 621 and is connected to the electrode assembly 100 in the central hole 140 of the electrode assembly 100. The vertical rotating tab 622 may extend, for example, vertically bent from the horizontal rotating tab 621, but is not necessarily limited thereto.

[0088] As the length of at least one of the positive electrode plate 110 and the negative electrode plate 120 increases, the vertical rotating tab 622 also rotates together with the horizontal rotating tab 621.

[0089] The connecting shaft 630 is connected to the first negative electrode tab 610 and the second negative electrode tab 620 so that the second negative electrode tab 620 can rotate. In addition, the connecting shaft 630 is fixed to the battery can 200 in various ways. For example, the connecting shaft 630 may be connected by welding, but is not limited thereto. The connecting shaft 630 serves as a rotating shaft for the second negative electrode tab 620.

[0090] Refer to Figure 2 , the top cover 700 may be configured to be electrically connected to the positive electrode tab 500 and electrically insulated from the battery can 200. Therefore, the top cover 700 can be used as the positive terminal of the cylindrical battery cell 10. The top cover 700 may be made of a conductive metal and is configured to cover the top opening of the battery can 200.

[0091] The top cover 700 may be seated on the curled portion 210 formed on the battery can 200 and fixed by forming a crimped portion 220. Here, a sealing gasket 230 may be inserted between the top cover 700 and the crimped portion 220 of the battery can 200 to ensure the airtightness of the battery can 200 and electrically insulate the battery can 200 from the top cover 700.

[0092] The curled portion 210 is formed by pressing the outer periphery of the battery can 200 inward. The curled portion 210 can support the electrode assembly 100. The curled portion 210 has a size substantially corresponding to the width of the battery can 200 so that the electrode assembly 100 does not come out of the top of the battery can 200, and can also be used as a support on which the top cover 700 is seated. In addition, the curled portion 210 can support the outer surface of the sealing gasket 230.

[0093] The crimped portion 220 is provided to extend and bend into the interior of the battery can 200 and together with the sealing gasket 230 wraps and fixes the edge of the top cover 700. Here, for example, refer to Figure 2 , in the configured state of the battery can 200, the crimped portion 220 may be formed in the upper portion of the battery can 200. In addition, as Figure 2As shown, the crimping portion 220 may be formed above the curled portion 210. However, this is merely an embodiment, and the positions of the crimping portion 220 and the curled portion 210 are not limited thereto.

[0094] In addition, the present disclosure does not exclude the case where the battery can 200 does not have at least one of the curled portion 210 and the crimping portion 220. In the present disclosure, if the battery can 200 does not have at least one of the curled portion 210 and the crimping portion 220, the fixing of the electrode assembly 100, the fixing of the top cover 700, or the sealing of the battery can 200 can be achieved by at least one of the following: additionally applying a component that can be used as a stopper for the electrode assembly 100, additionally applying a structure on which the top cover 700 can sit, and welding between the battery can 200 and the top cover 700.

[0095] In Figure 2 it, the crimping portion 220 is formed above the curled portion 210. The crimping portion 220 is configured to extend and bend so as to surround the edge of the top cover 700 provided on the curled portion 210. The top cover 700 is fixed to the curled portion 210 by the bent shape of the crimping portion 220.

[0096] Although not shown in the drawings of the present specification, a vent notch (not shown) may be formed to break the top cover 700 when the pressure inside the battery can 200 exceeds a threshold value.

[0097] Figure 5 is a schematic perspective view of a first negative tab and a second negative tab of a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure, Figure 6 is a schematic perspective view of a coupling shaft of a negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure, Figure 7 is a schematic perspective view of a coupling shaft coupling the first negative tab and the second negative tab of the negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure, and Figure 8 is a view illustrating a state in which the first negative tab of the negative tab in a cylindrical battery cell according to a second embodiment of the present disclosure rotates relative to the second negative tab inside the central opening of the insulator.

[0098] The second embodiment of the present disclosure is different from the first embodiment in configuration in that the second negative tab 620 is formed with an inner groove 625, and the coupling shaft 630 is formed with an outer protrusion 631. Here, for the same configuration, the description of the first embodiment can also be applied to this embodiment. In addition, the description of the second embodiment applicable to the first embodiment can also be applied to the first embodiment.

[0099] Referring to Figure 5, an inner groove 625 is formed in the inner portion of the second negative electrode tab 620. Here, the inner groove 625 can be formed in various ways.

[0100] For example, the inner groove 625 may include a first line 626 and a second line 627. The first line 626 is formed to be inclined from an arbitrary point. Additionally, the second line 627 is formed to be inclined from the opposite point of the arbitrary point toward the first line 626 to meet the first line 626.

[0101] Here, the inclination angle of the first line 626 and the inclination angle of the second line 627 can be formed to be different from each other.

[0102] Alternatively, the length of the first line 626 and the length of the second line 627 can be formed to be different from each other.

[0103] Referring to Figure 6 , an outer protrusion 631 can be formed on the outer surface of the coupling shaft 630. Although Figure 6 only one outer protrusion 631 is shown to be formed, a plurality of outer protrusions 631 can also be provided.

[0104] Referring to Figure 7 , the outer protrusion 631 is configured to contact the inner groove 625 and move along the inner groove 625 only in one direction.

[0105] That is, referring to Figure 7 and Figure 8 both, the outer protrusion 631 formed on the outer surface of the coupling shaft 630 moves along the inner groove 625 formed in the inner portion of the second negative electrode tab 620 only in one direction and cannot move in the opposite direction.

[0106] As the length of at least one of the positive electrode plate 110 and the negative electrode plate 120 increases due to the charging and discharging of the cylindrical battery cell 10, the second negative electrode tab 620 rotates only in one direction, thereby preventing the shape of the electrode assembly 100 from collapsing and short - circuiting of the cylindrical battery cell 10.

[0107] Figure 9 is a view showing an insulator in which an inner groove is formed in the central opening of a cylindrical battery cell according to a third embodiment of the present disclosure, Figure 10 is a schematic perspective view showing a state in which a negative electrode tab is coupled to the inner groove of the central opening of an insulator in a cylindrical battery cell according to a third embodiment of the present disclosure, and Figure 11 is a view showing a state in which Figure 10 the first negative electrode tab in the negative electrode tab rotates relative to the second negative electrode tab.

[0108] The third embodiment of the present disclosure differs in configuration from the first embodiment or the second embodiment in that an inner groove 411 is formed in the insulator 400. Here, for the same configuration, the descriptions of the first embodiment or the second embodiment can also be applied to this embodiment. Additionally, the descriptions of the third embodiment applicable to the first embodiment or the second embodiment can be applied to the first embodiment or the second embodiment.

[0109] Referring Figure 9 , an inner groove 411 is formed in the inner part of the central opening 410 of the insulator 400. Here, the inner groove 411 can be formed in various ways.

[0110] For example, the inner groove 411 may include a first line 412 and a second line 413. The first line 412 is formed to be inclined from an arbitrary point. Additionally, the second line 413 is formed to be inclined from the opposite point of the arbitrary point toward the first line 412 to meet the first line 412.

[0111] Here, the inclination angle of the first line 412 and the inclination angle of the second line 413 can be formed to be different from each other.

[0112] Alternatively, the length of the first line 412 and the length of the second line 413 can be formed to be different from each other.

[0113] Referring Figure 10 , the second negative electrode tab 620 is configured to contact the inner groove 411 and move only in one direction along the inner groove 411. That is, the side surface of the horizontal rotating tab 621 of the second negative electrode tab 620 is configured to rotate in a state of being caught by the inner groove 411 of the central opening 410 of the insulator 400. For this purpose, an angled portion 629, such as a corner, is formed on at least one side of the horizontal rotating tab 621 of the second negative electrode tab 620 so as to be caught by the inner groove 411 of the insulator 400.

[0114] Additionally, the angled portion 629 of the horizontal rotating tab 621 of the second negative electrode tab 620 is formed to contact the inner groove 411 of the central opening 410 of the insulator 400 and move only in one direction along the inner groove 411.

[0115] That is, the angled portion 629 of the horizontal rotating tab 621 of the second negative electrode tab 620 moves only in one direction along the inner groove 411 formed in the inner part of the central opening 410 of the insulator 400 and cannot move in the opposite direction.

[0116] Accordingly, as the length of at least one of the positive electrode plate 110 and the negative electrode plate 120 increases due to charging and discharging of the cylindrical battery cell 10, the second negative electrode tab 620 rotates only in one direction, thereby preventing the shape of the electrode assembly 100 from collapsing and short - circuiting of the cylindrical battery cell 10.

[0117] Figure 12 is a diagram according to Figure 9 a modified embodiment of the insulator in

[0118] Referring to Figure 12 , the insulator 400a according to the modified embodiment has a first line 412a that is longer than the first line in Figure 9 . That is, Figure 12 the length of the first line 412a of the inner groove 411a of the insulator 400a in Figure 9 is greater than the length of the first line 412 of the inner groove 411 of the insulator 400 in Figure 12 is Figure 9 a modified embodiment of Figure 9 and various modifications of the embodiment in

[0119] Figure 13 is a diagram schematically illustrating the configuration of a battery pack including cylindrical battery cells according to each embodiment of the present disclosure.

[0120] Referring to Figure 13 , the battery pack 20 according to an embodiment of the present disclosure may include one or more cylindrical battery cells 10 according to each of the above - described embodiments of the present disclosure. Additionally, the battery pack 20 may further include a pack housing 200 for storing the cylindrical battery cells 10, and various devices for controlling the charging and discharging of the cylindrical battery cells 10, such as a BMS, a current sensor, a fuse, etc.

[0121] Figure 14 is a diagram illustrating a vehicle including a battery pack according to each embodiment of the present disclosure.

[0122] Referring to Figure 14 , the vehicle 30 according to an embodiment of the present disclosure may include one or more cylindrical battery cells 10 or battery packs 20 according to each of the above - described embodiments. Here, the vehicle 30 includes various vehicles designed to use electricity, such as an electric vehicle or a hybrid vehicle.

[0123] Although terms indicating directions such as upward direction, downward direction, leftward direction, and rightward direction are used in this specification, it is obvious to those skilled in the art that these terms are for convenience of explanation only and may vary according to the position of the target object or the position of the observer.

[0124] As described above, although the present disclosure has been described with reference to limited embodiments and drawings, the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure pertains can make various modifications and variations within the equivalent scope of the technical concept of the present disclosure and the claims described below. Therefore, the previously disclosed embodiments should be regarded as those intended to describe the present disclosure, rather than those intended to limit the present disclosure. In other words, the true scope of the technical concept of the present disclosure is shown in the claims, and all differences within the equivalent scope thereof should be construed as being included in the present disclosure.

[0125] Industrial Applicability

[0126] The present disclosure relates to a cylindrical battery cell, a battery pack, and a vehicle including the cylindrical battery cell, and the present disclosure is particularly applicable to industries related to secondary batteries.

Claims

1. A cylindrical battery cell, comprising: An electrode assembly having the following structure: a positive electrode plate provided with a positive electrode tab, a negative electrode plate provided with a negative electrode tab, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, and a central hole is formed in the electrode assembly; A cylindrical battery can configured to store the electrode assembly, and an electrolyte is injected into the cylindrical battery can; And An insulator having a central opening formed therein, and the insulator is disposed on the negative electrode tab side to be coupled to the electrode assembly, Wherein at least a part of the negative electrode tab is configured to rotate according to changes in the electrode assembly during charging and discharging.

2. The cylindrical battery cell according to claim 1, Among them, The negative electrode tab includes: A first negative electrode tab fixed to the battery can; A second negative electrode tab positioned in the central hole of the electrode assembly, the second negative electrode tab being coupled to the electrode assembly and configured to rotate relative to the first negative electrode tab; and A coupling shaft coupling the first negative electrode tab and the second negative electrode tab such that the second negative electrode tab can rotate.

3. The cylindrical battery cell according to claim 2, Among them, The second negative electrode tab rotates within the central opening of the insulator.

4. The cylindrical battery cell according to claim 2, Among them, The second negative electrode tab rotates as the length of at least one of the positive electrode plate and the negative electrode plate increases due to charging and discharging.

5. The cylindrical battery cell according to claim 2, Among them, The first negative electrode tab includes: A horizontally fixed tab formed in the horizontal direction based on the arrangement state of the battery can; and A vertically fixed tab configured to extend and bend from the horizontally fixed tab and positioned between the outermost side of the electrode assembly and the battery can.

6. The cylindrical battery cell according to claim 2, Among them, The second negative electrode tab includes: A horizontally rotating tab formed in the horizontal direction based on the arrangement state of the battery can; and A vertically rotating tab configured to extend and bend from the horizontally rotating tab and coupled to the electrode assembly in the central hole of the electrode assembly.

7. The cylindrical battery cell according to claim 2, Among them, An inner groove is formed in the inner side portion of the second negative electrode tab, and Wherein, an outer protrusion is formed on the outer surface of the coupling shaft so as to contact the inner groove and move only in one direction along the inner groove.

8. The cylindrical battery cell according to claim 7, Among them, The inner groove includes: A first line formed to be inclined from an arbitrary point; and A second line formed to be inclined from the opposite point of the arbitrary point toward the first line to meet the first line, Wherein, the inclination angle of the first line and the inclination angle of the second line are different from each other.

9. The cylindrical battery cell according to claim 7, Among them, The inner groove includes: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to join the first line, wherein the length of the first line and the length of the second line are different from each other.

10. The cylindrical battery cell according to claim 1, Among them, wherein an inner portion of the central opening of the insulator is formed with an inner groove, and wherein the second negative tab is configured to contact the inner groove and move only in one direction along the inner groove.

11. The cylindrical battery cell according to claim 10, Among them, the inner groove includes: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to join the first line, wherein the inclination angle of the first line and the inclination angle of the second line are different from each other.

12. The cylindrical battery cell according to claim 10, Among them, the inner groove includes: a first line formed to be inclined from an arbitrary point; and a second line formed to be inclined from the opposite point of the arbitrary point toward the first line to join the first line, wherein the length of the first line and the length of the second line are different from each other.

13. A battery pack including at least one cylindrical battery cell according to any one of claims 1 to 12.

14. A vehicle including at least one cylindrical battery cell according to any one of claims 1 to 12.

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