Cylindrical battery cell, and battery pack and vehicle comprising same

Abstract

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

Description

Cylindrical battery cells and battery packs and vehicles including the same

[0001] This application claims priority to Korean Patent Application No. 10-2023-0104435, filed on August 9, 2023, and all contents disclosed in the specification and drawings of the said application are incorporated herein by reference.

[0002] The present invention relates to a cylindrical battery cell, a battery pack including the same, and a vehicle, and more particularly, to a cylindrical battery cell capable of preventing a short circuit by preventing the shape collapse of an electrode assembly, and a battery pack including the same and a vehicle.

[0003] Secondary batteries, which have high applicability according to product group and electrical characteristics such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) driven by electrical power sources.

[0004] These secondary batteries are attracting attention as a new energy source for environmental friendliness and energy efficiency because they not only have the primary advantage of drastically reducing the use of fossil fuels, but also have the advantage of producing no byproducts from energy use.

[0005] Commonly used secondary battery types include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells ranges from approximately 2.5 V to 4.5 V.

[0006] Therefore, when a higher output voltage is required, multiple battery cells are connected in series to form a battery module or battery pack. Furthermore, depending on the required charge / discharge capacity, a number of battery cells are connected in parallel to form a battery module or battery pack. Accordingly, the number and electrical connection configuration of battery cells included in a battery module or battery pack can be varied depending on at least one of the required output voltage and charge / discharge capacity.

[0007] Meanwhile, known secondary battery cell types include cylindrical, square, and pouch-shaped battery cells. Cylindrical battery cells are formed by interposing a separator, which serves as an insulator, between the positive and negative plates, winding the separator to form a jelly-roll-shaped electrode assembly. This assembly, along with an electrolyte, is then inserted into a battery can to form the battery.

[0008] Figure 1 is a drawing showing changes in the length of the positive and negative plates of an electrode assembly when a conventional cylindrical battery cell is repeatedly charged and discharged.

[0009] In general, when charging and discharging of a cylindrical battery cell is continuously performed, the length of the positive plate (2) or negative plate (4) of the electrode assembly (1) increases as contraction and relaxation are repeated.

[0010] However, since the electrode assembly (1) is housed inside a cylindrical battery can (not shown in FIG. 1, for example, made of metal material), the shape cannot change outside the battery can even if the length of the positive electrode plate (2) or the negative electrode plate (4) increases.

[0011] Accordingly, as shown in Fig. 1, the shape of the positive electrode plate (2), the separator (3), or the negative electrode plate (4) changes toward the center of the electrode assembly (1). However, if the positive electrode plate (2), the separator (3), or the negative electrode plate (4) folds toward the center of the electrode assembly (1) and the shape of the electrode assembly (1) collapses, a short circuit may occur inside the cell, which may cause stability problems.

[0012] Accordingly, the technical problem to be solved by the present invention is to provide a cylindrical battery cell capable of preventing the shape of the electrode assembly from collapsing when the cylindrical battery cell is repeatedly charged and discharged, and a battery pack and a vehicle including the same.

[0013] In addition, the present invention provides a cylindrical battery cell capable of preventing a short circuit in the cylindrical battery cell, and a battery pack and a vehicle including the same.

[0014] However, the technical problems to be solved by the present invention are not limited to the problems described above, and other problems not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0015] According to one aspect of the present invention, a cylindrical battery cell can be provided, comprising: an electrode assembly having a structure in which a positive electrode plate having a positive tab, a negative electrode plate having a negative 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; a cylindrical battery can in which the electrode assembly is accommodated and an electrolyte is injected; and an insulator having a central opening formed therein and arranged on the negative electrode tab side and coupled to the electrode assembly, wherein at least a portion of the negative electrode tab is configured to rotate according to a change in the electrode assembly during charging and discharging.

[0016] In one 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 center hole of the electrode assembly and coupled to the electrode assembly, the second negative electrode tab rotating with respect 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.

[0017] In one embodiment, the second negative tab can rotate inside the central opening of the insulator.

[0018] In one embodiment, the second negative electrode tab can rotate as the length of at least one of the positive electrode plate and the negative electrode plate increases due to charging and discharging.

[0019] In one embodiment, the first negative tab may include a fixed horizontal tab formed in a horizontal direction based on the arrangement of the battery can; and a fixed vertical tab extending in a bent manner from the fixed horizontal tab and positioned between the outermost side of the electrode assembly and the battery can.

[0020] In one embodiment, the second negative electrode tab may include a rotating horizontal tab formed in a horizontal direction based on the arrangement of the battery can; and a rotating vertical tab extending in a bent manner from the rotating horizontal tab and coupled to the electrode assembly in the central hole of the electrode assembly.

[0021] In one embodiment, an inner groove may be formed on the inner side of the second negative tab, and an outer protrusion may be formed on the outer side of the coupling shaft so as to contact the inner groove and move in only one direction along the inner groove.

[0022] In one embodiment, the inner groove includes a first line formed inclined from an arbitrary point; and a second line formed inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, wherein the inclined angle of the first line and the inclined angle of the second line may be different from each other.

[0023] In one embodiment, the inner groove includes a first line formed inclined from an arbitrary point; and a second line formed inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, wherein the length of the first line and the length of the second line may be different from each other.

[0024] In one embodiment, an inner groove is formed inside the central opening of the insulator, and the second negative electrode tab may be formed to contact the inner groove and move in only one direction along the inner groove.

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

[0026] In one embodiment, the inner groove includes a first line formed inclined from an arbitrary point; and a second line formed inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, wherein the length of the first line and the length of the second line may be different from each other.

[0027] Meanwhile, according to another aspect of the present invention, a battery pack including at least one cylindrical battery cell as described above may be provided, and further, a vehicle including at least one cylindrical battery cell as described above may be provided.

[0028] Embodiments of the present invention have the effect of preventing the shape of the electrode assembly from collapsing when the cylindrical battery cell is repeatedly charged and discharged by configuring at least a portion of the negative tab to rotate.

[0029] In addition, this has the effect of preventing short circuits in cylindrical battery cells.

[0030] However, the effects that can be obtained through the present invention are not limited to the effects described above, and other technical effects not mentioned can be clearly understood by those skilled in the art from the description of the invention described below.

[0031] Figure 1 is a drawing showing changes in the length of the positive and negative plates of an electrode assembly when a conventional cylindrical battery cell is repeatedly charged and discharged.

[0032] FIG. 2 is a cross-sectional view of a cylindrical battery cell according to the first embodiment of the present invention.

[0033] FIG. 3 is a schematic perspective view of a cylindrical battery cell according to the first embodiment of the present invention, wherein a coupling shaft is coupled to the first negative tab and the second negative tab of the negative tab.

[0034] FIG. 4 is a drawing showing the first negative tab of the negative tab in FIG. 3 rotating relative to the second negative tab.

[0035] FIG. 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 invention.

[0036] FIG. 6 is a schematic perspective view of the coupling axis of the negative tab in a cylindrical battery cell according to the second embodiment of the present invention.

[0037] FIG. 7 is a schematic perspective view of a cylindrical battery cell according to a second embodiment of the present invention, wherein a coupling shaft is coupled to a first negative tab and a second negative tab of the negative tab.

[0038] FIG. 8 is a drawing illustrating a state in which a first negative tab of a negative tab rotates relative to a second negative tab within a central opening of an insulator in a cylindrical battery cell according to a second embodiment of the present invention.

[0039] FIG. 9 is a drawing showing an insulator having an inner groove formed in a central opening in a cylindrical battery cell according to a third embodiment of the present invention.

[0040] FIG. 10 is a schematic perspective view of a cylindrical battery cell according to a third embodiment of the present invention, in which a negative tab is coupled to an inner groove of a central opening of an insulator.

[0041] FIG. 11 is a drawing showing the first negative tab of the negative tab in FIG. 10 rotating relative to the second negative tab.

[0042] Fig. 12 is a drawing showing an insulator according to a modified embodiment of the insulator of Fig. 9.

[0043] FIG. 13 is a schematic drawing showing the configuration of a battery pack including a cylindrical battery cell according to each embodiment of the present invention.

[0044] FIG. 14 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0045] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Terms or words used in this specification and claims should not be interpreted as limited to their conventional or dictionary meanings, but should be interpreted with meanings and concepts that conform to the technical idea of ​​the present invention based on the principle that the inventor can appropriately define the concept of the term to best explain his or her own invention. Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are only the most preferred embodiments of the present invention and do not represent all of the technical idea of ​​the present invention, and various equivalents and modifications may exist as of the time of this application.

[0046] In the drawings, the sizes of each component or specific parts of that component are exaggerated, omitted, or schematically illustrated for convenience and clarity of explanation. Therefore, the size of each component does not entirely reflect its actual size. If a detailed description of a related known function or configuration is deemed to unnecessarily obscure the gist of the present invention, such description will be omitted.

[0047] The term 'joint' or 'connection' as used herein includes not only cases where one member is directly joined or directly connected to another member, but also cases where one member is indirectly joined or indirectly connected to another member through a connecting member.

[0048] FIG. 2 is a cross-sectional view of a cylindrical battery cell according to a first embodiment of the present invention, FIG. 3 is a schematic perspective view of a state in which a coupling shaft is coupled to a first negative tab and a second negative tab of a negative tab in a cylindrical battery cell according to the first embodiment of the present invention, and FIG. 4 is a drawing illustrating a state in which the first negative tab of the negative tab in FIG. 3 rotates relative to the second negative tab.

[0049] Referring to FIG. 2, a cylindrical battery cell (10) according to the first embodiment of the present invention includes an electrode assembly (100), a battery can (200), and an insulator (400).

[0050] Referring to FIG. 2, the electrode assembly (100) has a structure in which a positive electrode plate (110) having a positive electrode tab (500), a negative electrode plate (120) having 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) is formed in the center of the electrode assembly (100), and can be formed in a jelly roll type.

[0051] For example, the electrode assembly (100) can be manufactured by winding a laminate formed by sequentially stacking a negative electrode plate (120), a separator (130), a positive electrode plate (110), and a separator (130) at least once. Here, the positive electrode plate (110) and the negative electrode plate (120) can be formed in a sheet shape.

[0052] That is, the electrode assembly (100) applied to the present embodiment may be a coil-type electrode assembly (100). In this case, an additional separator (not shown) may be provided on the outer circumferential surface of the electrode assembly (100) for insulation from the battery can (200). That is, the electrode assembly (100) may have a coil-type structure well known in the related art without limitation.

[0053] A positive electrode plate (110) has a positive electrode active material applied to one or both sides. Here, a positive electrode tab (500) is provided on the positive electrode plate (110). In addition, a negative electrode active material is applied to one or both sides of the negative electrode plate (120). Here, a negative electrode tab (600) is provided on the negative electrode plate (120). A detailed description of the negative electrode tab (600) will be described later.

[0054] In addition, 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) can be used without limitation as long as they are active materials known in the art.

[0055] The separation membrane (130) may be a porous polymer film, for example, 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., which may be used alone or in a laminated manner.

[0056] As another example, the separator (130) may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fiber, polyethylene terephthalate fiber, etc.

[0057] At least one surface of the separator (130) may include a coating layer of inorganic particles. Furthermore, the separator (130) itself may be formed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure in which they are combined with a binder such that an interstitial volume exists between adjacent particles.

[0058] Referring to FIG. 2, an electrode assembly (100) is housed in a battery can (200), and an electrolyte is injected therein. For example, the battery can (200) is formed in a cylindrical shape, and the electrode assembly (100) is housed 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) can have the same polarity as the negative electrode plate (120), i.e., a negative electrode.

[0059] Here, 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 material of the battery can (200) may be made of a conductive metal, such as aluminum, steel, stainless steel, etc., but is not limited thereto.

[0060] An insulator (400) is coupled to the electrode assembly (100) for electrical insulation. In FIG. 2, the insulator (400) is coupled to the lower side of the electrode assembly (100). In addition, an insulator (300) is coupled to the electrode assembly (100) for electrical insulation. In FIG. 2, the insulator (300) is coupled to the upper side of the electrode assembly (100).

[0061] The insulator (300) is positioned on the positive tab (500) side and coupled to the electrode assembly (100), and the insulator (400) is positioned on the negative tab (600) side and coupled to the electrode assembly (100). For convenience of explanation, the insulator (400) positioned on the negative tab (600) side and coupled to the electrode assembly (100) will be described below. However, common content regarding the insulator (300) in the description regarding the insulator (400) is replaced with a description regarding the insulator (400).

[0062] The insulator (400) may be formed in a shape corresponding to the cross-sectional shape of the jellyroll-type electrode assembly (100). For example, if the cross-sectional shape of the jellyroll-type electrode assembly (100) is circular, the shape of the insulator (400) may also be circular. In addition, the insulator (400) is formed with, for example, a circular central opening (410). In addition, the insulator (300) is formed with, for example, a circular central opening (310).

[0063] The insulator (400) may, for example, include an elastic material. Accordingly, when vibration or an external impact is applied to the cylindrical battery cell (10), the insulator (400) can absorb the impact by being compressed by its elasticity and then returning to its original state. Accordingly, even when vibration or an external impact is applied to the battery cell, damage to the internal components of the battery cell can be minimized.

[0064] The insulator (400) may be made of a material having insulating properties. Preferably, the insulator (400) may include, but is not limited to, an insulating polymer material. For example, the insulator (400) may be made of polyethylene terephthalate (PET), polybutylene terephthalate (PBT), or polypropylene (PP).

[0065] The cylindrical battery cell (10) according to the first embodiment of the present invention is configured so that at least a portion of the negative tab (600) rotates when the length or shape of the electrode assembly (100) changes, for example, in order to prevent the shape of the electrode assembly (100) from collapsing and to prevent a short circuit of the cylindrical battery cell (10).

[0066] As described above, when charging and discharging of a cylindrical battery cell (10) is continuously performed, the length of the positive plate (110) or negative plate (120) increases as contraction and relaxation of the positive plate (110) or negative plate (120) are repeated. However, since the electrode assembly (100) is housed inside a cylindrical battery can (200), even if the length of the positive plate (110) or negative plate (120) increases, the shape cannot change outside the battery can (200).

[0067] However, if at least a portion of the negative electrode tab (600) is configured to rotate, the positive electrode plate (110) or negative electrode plate (120) does not fold toward the center even if the length of the positive electrode plate (110) or negative electrode plate (120) increases during charging and discharging.

[0068] That is, in the case of a conventional cylindrical battery cell as shown in Fig. 1, even if the positive electrode plate (1) or the negative electrode plate (4) is stretched due to force during charging and discharging, the negative electrode tab is fixed to the battery can and cannot move, and eventually the positive electrode plate (1) or the negative electrode plate (4) is folded toward the center hole of the electrode assembly (1) at the part receiving the force.

[0069] However, in the cylindrical battery cell (10) according to the first embodiment of the present invention, when the positive electrode plate (110) or the negative electrode plate (120) is stretched due to force during charging and discharging, at least a portion of the negative electrode tab (600) is not fixed and rotates, so the positive electrode plate (110) or the negative electrode plate (120) does not fold toward the center hole (140) of the electrode assembly (100).

[0070] That is, in the first embodiment of the present invention, the force generated during charging and discharging is converted into a rotational force of the negative electrode tab (600), so that the shape of the electrode assembly (100) is not collapsed, and thus, a short circuit of the cylindrical battery cell (10) can be prevented.

[0071] Referring to FIGS. 2 and 3 together, 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).

[0072] The first negative tab (610) is fixed to the battery can (200). The method by which the first negative tab (610) is fixed may vary, and for example, it may be fixed to the battery can (200) through welding.

[0073] The first negative tab (610) may include a fixed horizontal tab (611) and a fixed vertical tab (612).

[0074] The fixed horizontal tab (611) is formed in a horizontal direction based on the arrangement of the battery can (200). For example, when the battery can (200) is arranged as in FIG. 2, the fixed horizontal tab (611) can be arranged in a left-right direction at the bottom of the battery can (200).

[0075] In addition, the fixed vertical tab (612) may be extended in a bent manner from the fixed horizontal tab (611) and positioned between the outermost side of the electrode assembly (100) and the battery can (200). The fixed vertical tab (612) may be extended in a vertical manner from the fixed horizontal tab (611), for example, but is not necessarily limited to being vertical.

[0076] In addition, the first negative tab (610) is fixedly connected to at least one of the bottom of the battery can (200) and the side of the battery can (200). That is, the fixed horizontal tab (611) can be connected to the bottom of the battery can (200) by welding or the like, and further, the fixed vertical tab (612) can be connected to the side of the battery can (200) by welding or the like.

[0077] The second negative electrode tab (620) is positioned in the center hole (140) of the electrode assembly (100) and is coupled to the electrode assembly (100) and is configured to rotate with respect to the first negative electrode tab (610). That is, the second negative electrode tab (620) is provided to be rotatable about the coupling axis (630) as the rotation axis.

[0078] And, since one side of the second negative electrode tab (620) is connected to the electrode assembly (100), when 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), when force is applied to the electrode assembly (100), the second negative electrode tab (620) rotates due to the force.

[0079] And, since the second negative electrode tab (620) rotates, as described above, the force acting on the electrode assembly (100) is changed into a rotational force, and thus the collapse of the shape of the electrode assembly (100) can be prevented.

[0080] Referring to FIGS. 2 and 3, the second negative electrode tab (620) may be configured to rotate inside the central opening (410, see FIG. 8 of the second embodiment) of the insulator (400). That is, the diameter of the central opening (410) of the insulator (400) may be formed larger than the rotation diameter of the second negative electrode tab (620), so that the second negative electrode tab (620) may not interfere with the insulator (400) when rotating.

[0081] The second cathode tab may include a rotating horizontal tab (621) and a rotating vertical tab (622).

[0082] The rotary horizontal tab (621) is formed in a horizontal direction based on the arrangement of the battery can (200). For example, when the battery can (200) is arranged as in FIG. 2, the rotary horizontal tab (621) can be arranged in a left-right direction at the bottom of the battery can (200).

[0083] And, the rotary horizontal tab (621) rotates together with the rotary vertical tab (622) as the length of at least one of the positive electrode plate (110) and the negative electrode plate (120) increases.

[0084] The rotary vertical tab (622) extends in a bent manner from the rotary horizontal tab (621) and is coupled to the electrode assembly (100) in the center hole (140) of the electrode assembly (100). The rotary vertical tab (622) may extend in a vertical manner from the rotary horizontal tab (621), for example, but is not necessarily limited to being vertical.

[0085] The rotary vertical tab (622) also rotates together with the rotary horizontal tab (621) as the length of at least one of the positive electrode plate (110) and the negative electrode plate (120) increases.

[0086] The coupling shaft (630) is coupled to the first negative tab (610) and the second negative tab (620) so that the second negative tab (620) can rotate. In addition, the coupling shaft (630) is coupled and fixed to the battery can (200) in various ways. For example, it may be coupled by welding, but is not limited thereto. The coupling shaft (630) functions as a rotational axis for the second negative tab (620).

[0087] Referring to FIG. 2, the top cap (700) may be configured to be electrically connected to the positive electrode tab (500) and electrically insulated from the battery can (200). Accordingly, the top cap (700) may function as a positive electrode terminal of the cylindrical battery cell (10). The top cap (700) may be made of a conductive metal material and configured to cover the upper opening of the battery can (200).

[0088] The top cap (700) can be placed on the beading portion (210) formed on the battery can (200) and fixed by forming the crimping portion (220). Here, a sealing gasket (230) can be interposed between the top cap (700) and the crimping portion (220) of the battery can (200) to ensure airtightness of the battery can (200) and electrical insulation between the battery can (200) and the top cap (700).

[0089] The beading portion (210) is formed by pressing the outer circumference of the battery can (200) inward. The beading portion (210) supports the electrode assembly (100) so that the electrode assembly (100), which has a size roughly corresponding to the width of the battery can (200), does not come out through the upper portion of the battery can (200), and can also function as a support on which the top cap (700) is secured. In addition, the beading portion (210) can support the outer circumferential surface of the sealing gasket (230).

[0090] The crimping portion (220) is provided to extend and bend inwardly of the battery can (200) and to wrap and secure the edge of the top cap (700) together with the sealing gasket (230). Here, for example, referring to FIG. 2, the crimping portion (220) may be formed on the upper portion of the battery can (200) based on the arrangement of the battery can (200). In addition, as shown in FIG. 2, the crimping portion (220) may be formed on the upper portion of the beading portion (210). However, this is only one embodiment, and the positions of the crimping portion (220) and the beading portion (210) are not limited thereto.

[0091] In addition, the present invention does not exclude a case where the battery can (200) does not have at least one of the beading portion (210) and the crimping portion (220). In the present invention, when the battery can (200) does not have at least one of the beading portion (210) and the crimping portion (220), fixing of the electrode assembly (100) or fixing of the top cap (700) or sealing of the battery can (200) can be realized through at least one of additional application of a component that can function as a stopper for the electrode assembly (100), additional application of a structure on which the top cap (700) can be secured, and welding between the battery can (200) and the top cap (700).

[0092] Referring to Fig. 2, the crimping portion (220) is formed on the upper portion of the beading portion (210). The crimping portion (220) has an extended and bent shape so as to wrap around the edge of the top cap (700) positioned on the upper portion of the beading portion (210). Due to the shape of the folded crimping portion (220), the top cap (700) is fixed on the beading portion (210).

[0093] Although not shown in the drawings of this specification, a vent notch (not shown) may be formed to cause the top cap (700) to rupture when the pressure inside the battery can (200) exceeds a threshold.

[0094] FIG. 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 invention, FIG. 6 is a schematic perspective view of a coupling axis of a negative tab in a cylindrical battery cell according to a second embodiment of the present invention, FIG. 7 is a schematic perspective view of a state in which a coupling axis is coupled to 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 invention, and FIG. 8 is a drawing illustrating 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 invention rotates relative to a second negative tab within a central opening of an insulator.

[0095] The second embodiment of the present invention differs in structure from the first embodiment in that an inner groove (625) is formed in the second negative tab (620) and an outer protrusion (631) is formed in the coupling shaft (630). Here, the common content described in the first embodiment is replaced with the description of the first embodiment described above. In addition, the content applicable to the first embodiment among the parts described in the second embodiment can be applied to the first embodiment.

[0096] Referring to Fig. 5, an inner groove (625) is formed on the inner side of the second negative tab (620). Here, the inner groove (625) can be formed in various ways.

[0097] 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. And, the second line (627) is formed to be inclined toward the first line (626) so as to meet the first line (626) from an opposite point of the arbitrary point.

[0098] Here, the inclined angle of the first line (626) and the inclined angle of the second line (627) can be formed differently.

[0099] Alternatively, the length of the first line (626) and the length of the second line (627) may be formed differently.

[0100] Referring to Fig. 6, an outer protrusion (631) may be formed on the outer side of the coupling shaft (630). In Fig. 6, only one outer protrusion (631) is formed, but there may be multiple outer protrusions (631).

[0101] Referring to Fig. 7, the outer protrusion (631) is formed to contact the inner groove (625) and move in only one direction along the inner groove (625).

[0102] That is, referring to FIGS. 7 and 8 together, the outer protrusion (631) formed on the outer side of the coupling shaft (630) moves only in one direction along the inner groove (625) formed on the inner side of the second negative tab (620), and movement in the opposite direction is prevented.

[0103] 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 collapse of the electrode assembly (100) and also preventing a short circuit of the cylindrical battery cell (10).

[0104] FIG. 9 is a drawing showing an insulator having an inner groove formed in a central opening in a cylindrical battery cell according to a third embodiment of the present invention, FIG. 10 is a 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 invention, and FIG. 11 is a drawing showing a state in which a first negative tab of the negative tab in FIG. 10 rotates relative to a second negative tab.

[0105] The third embodiment of the present invention differs in structure from the first or second embodiment in that an inner groove (411) is formed in the insulator (400). Here, the common content described in the first or second embodiment is replaced with the description of the first or second embodiment described above. In addition, the content applicable to the first or second embodiment among the parts described in the third embodiment can be applied to the first or second embodiment.

[0106] Referring to Fig. 9, an inner groove (411) is formed inside the central opening (410) of the insulator (400). Here, the inner groove (411) can be formed in various ways.

[0107] 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. And, the second line (413) is formed to be inclined toward the first line (412) so as to meet the first line (412) from an opposite point of the arbitrary point.

[0108] Here, the inclined angle of the first line (412) and the inclined angle of the second line (413) can be formed differently.

[0109] Alternatively, the length of the first line (412) and the length of the second line (413) may be formed differently.

[0110] Referring to FIG. 10, the second negative electrode tab (620) is formed to contact the inner groove (411) and move in only one direction along the inner groove (411). That is, the side portion of the rotational transverse tab (621) of the second negative electrode tab (620) is configured to rotate while being caught in the inner groove (411) of the central opening (410) of the insulator (400). To this end, an angled portion (629) such as a corner is formed on at least one side of the rotational transverse tab (621) of the second negative electrode tab (620) so as to be caught in the inner groove (411) of the insulator (400).

[0111] And, the angled portion (629) of the rotary transverse tab (621) of the second negative tab (620) is formed to contact the inner groove (411) of the central opening (410) of the insulator (400) and move in only one direction along the inner groove (411).

[0112] That is, the angled portion (629) of the rotary transverse tab (621) of the second negative tab (620) moves only in one direction along the inner groove (411) formed on the inside of the central opening (410) of the insulator (400), and movement in the opposite direction is prevented.

[0113] 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 collapse of the electrode assembly (100) and also preventing a short circuit of the cylindrical battery cell (10).

[0114] Fig. 12 is a drawing showing an insulator according to a modified embodiment of the insulator of Fig. 9.

[0115] Referring to Fig. 12, in the case of the insulator (400a) according to the modified embodiment, the length of the first line (412a) is longer than that of Fig. 9. That is, the length of the first line (412a) of the inner groove (411a) of the insulator (400a) of Fig. 12 is longer than the length of the first line (412) of the inner groove (411) of the insulator (400) of Fig. 9. Accordingly, there is also a difference in the number of inner grooves (411, 411a). Fig. 12 is one modified embodiment of Fig. 9, and the modified embodiment of Fig. 9 may be more diverse.

[0116] FIG. 13 is a schematic drawing showing the configuration of a battery pack including a cylindrical battery cell according to each embodiment of the present invention.

[0117] Referring to FIG. 13, a battery pack (20) according to one embodiment of the present invention may include one or more cylindrical battery cells (10) according to each embodiment of the present invention as described above. In addition, the battery pack (20) may further include a pack housing (200) for storing the cylindrical battery cells (10), and various devices for controlling charging and discharging of the cylindrical battery cells (10), such as a BMS, a current sensor, a fuse, etc.

[0118] FIG. 14 is a drawing for explaining a vehicle including a battery pack according to each embodiment of the present invention.

[0119] Referring to FIG. 14, a vehicle (30) according to one embodiment of the present invention 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 types of vehicles that are designed to use electricity, such as electric vehicles or hybrid vehicles.

[0120] In this specification, when terms indicating directions such as up, down, left, and right are used, these terms are only for convenience of explanation, and it is obvious to those skilled in the art that these terms may vary depending on the location of the target object or the location of the observer.

[0121] Although the present invention has been described above with reference to limited 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 scope of the technical spirit of the present invention and the equivalent scope of the claims to be described below. Therefore, the embodiments disclosed above should be considered in an illustrative rather than a restrictive sense. In other words, the true scope of the technical spirit of the present invention is set forth in the claims, and all differences within the scope of equivalents thereof should be construed as being included in the present invention.

[0122] The present invention relates to a cylindrical battery cell, a battery pack including the same, and an automobile, and is particularly applicable to industries related to secondary batteries.

Claims

1. An electrode assembly having a structure in which a positive electrode plate having a positive tab, a negative electrode plate having a negative tab, and a separator interposed between the positive electrode plate and the negative electrode plate are wound in one direction, and a center hole is formed; A cylindrical battery can in which the electrode assembly is housed and into which an electrolyte is injected; and An insulator having a central opening formed therein and positioned on the negative tab side and coupled to the electrode assembly, A cylindrical battery cell characterized in that at least a portion of the negative electrode tab is configured to rotate according to a change in the electrode assembly during charging and discharging.

2. In paragraph 1, The above negative tab is, A first negative tab fixed to the battery can; A second negative electrode tab positioned in the center hole of the electrode assembly and coupled to the electrode assembly, and rotating with respect to the first negative electrode tab; and A cylindrical battery cell characterized in that it includes a coupling shaft coupled to the first negative tab and the second negative tab so that the second negative tab can rotate.

3. In paragraph 2, A cylindrical battery cell characterized in that the second negative tab rotates inside the central opening of the insulator.

4. In paragraph 2, A cylindrical battery cell characterized in that the second negative electrode tab rotates as the length of at least one of the positive electrode plate and the negative electrode plate increases by charging and discharging.

5. In paragraph 2, The above first negative tab is, A fixed horizontal tab formed in a horizontal direction based on the arrangement of the above battery cans; and A cylindrical battery cell characterized by including a fixed vertical tab extending from the fixed horizontal tab and positioned between the outermost side of the electrode assembly and the battery can.

6. In paragraph 2, The above second negative tab is, A rotary horizontal tab formed in a horizontal direction based on the arrangement of the above battery cans; and A cylindrical battery cell characterized by including a rotating vertical tab extending in a bending manner from the rotating horizontal tab and coupled to the electrode assembly in the central hole of the electrode assembly.

7. In paragraph 2, An inner groove is formed on the inner side of the second negative tab, A cylindrical battery cell characterized in that an outer protrusion is formed on the outer side of the above-mentioned coupling shaft so as to come into contact with the inner groove and move in only one direction along the inner groove.

8. In paragraph 7, The inner groove above is, A first line formed inclined from an arbitrary point; and A second line formed to be inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, A cylindrical battery cell characterized in that the inclined angle of the first line and the inclined angle of the second line are different from each other.

9. In paragraph 7, The inner groove above is, A first line formed inclined from an arbitrary point; and A second line formed to be inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, A cylindrical battery cell characterized in that the length of the first line and the length of the second line are different from each other.

10. In paragraph 1, An inner groove is formed inside the central opening of the above insulator, A cylindrical battery cell characterized in that the second negative tab is formed to contact the inner groove and move in only one direction along the inner groove.

11. In paragraph 10, The inner groove above is, A first line formed inclined from an arbitrary point; and A second line formed to be inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, A cylindrical battery cell characterized in that the inclined angle of the first line and the inclined angle of the second line are different from each other.

12. In paragraph 10, The inner groove above is, A first line formed inclined from an arbitrary point; and A second line formed to be inclined toward the first line so as to meet the first line from an opposite point of the arbitrary point, A cylindrical battery cell characterized in that the length of the first line and the length of the second line are different from each other.

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

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

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