Battery cell and insulator applied thereto, and battery pack and vehicle comprising same

Abstract

The present invention provides a battery cell and an insulator applied thereto, and a battery pack and a vehicle comprising same, the battery cell comprising: a battery can having a side wall member, a bottom member connected to one end of the side wall member in the axial direction, and an opening provided at the other end of the side wall member in the axial direction; an electrode assembly, which is accommodated through the opening of the battery can, and in which a first electrode, a second electrode and a separator interposed therebetween are wound around a winding axis; a cap for covering the opening of the battery can; and an insulator, which is interposed between one end of the electrode assembly in the winding axis direction and the bottom member, has a central hole formed in a central axis direction, and includes at least one central hole extension part that is recessed in the central axis direction in a region of the outer circumference of the central hole and extends in a radial direction.

Description

Battery cells and insulators applied thereto, and battery packs including the same and automobiles

[0001] The present invention relates to a battery cell and an insulator applied thereto, and a battery pack and an automobile including the same. More specifically, the invention relates to a battery cell and an insulator applied thereto designed to maximize the jelly-roll discharge amount during venting, and a battery pack and an automobile including the same.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2025-0011570 filed on January 24, 2025, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, not only for the primary advantage of drastically reducing the use of fossil fuels but also because they generate no by-products from energy use.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage or charge / discharge capacity.

[0005] Meanwhile, in battery cell design, the venting structure plays a crucial role in preventing the risk of explosion or fire by rapidly releasing internal gas in the event of abnormal accumulation. The primary purpose of the venting structure is to effectively and rapidly relieve internal pressure, and a higher discharge volume from the electrode assembly is advantageous for this process. A higher discharge volume facilitates a smoother gas release path, enabling the rapid relief of internal cell pressure and significantly enhancing safety.

[0006] However, an insulator for electrical insulation may be interposed between one electrode of the electrode assembly and the battery can, and the shape of such an insulator directly affects the discharge efficiency of the electrode assembly during venting. If the insulator is not properly designed, the discharge of the electrode assembly may not be smooth, which may delay internal pressure relief and reduce the safety of the battery cell.

[0007] Therefore, it is necessary to develop a new insulator design that can maintain electrical insulation while supporting the smooth discharge of the electrode assembly during the venting process.

[0008] Accordingly, the technical problem to be solved by the present invention is to provide a battery cell capable of maximizing the jelly-roll discharge amount during battery cell venting, an insulator applied thereto, a battery pack including the same, and an automobile.

[0009] In addition, the invention provides a battery cell and an insulator applied thereto that maintain insulation function and can be ruptured more efficiently upon battery cell venting, as well as a battery pack including the same and an automobile.

[0010] In addition, the invention provides a battery cell and an insulator applied thereto, capable of smoothly ejecting internal residue, as well as a battery pack and a vehicle including the same.

[0011] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0012] To solve the above objective, the present invention provides a battery cell characterized by comprising: a battery can having a side wall member, a bottom member connected to one end in the axial direction of the side wall member, and an opening provided at the other end in the axial direction of the side wall member; an electrode assembly received through the opening of the battery can, wherein a first electrode, a second electrode, and a separator interposed between them are wound around a winding axis; a cap covering the opening of the battery can; and an insulator interposed between one end in the winding axis direction of the electrode assembly and the bottom member, having a center hole formed along the center axis direction, and including at least one center hole extension portion that is recessed in the center axis direction in a part of the outer circumference of the center hole and extends along the radial direction.

[0013] For example, the central hole defines the inner surface of the insulator surrounding the central axis of the insulator, and the central hole extension extends along the radial direction from the inner surface of the insulator and is formed radially outward from the central hole, and can form a step on the inner surface of the insulator along the circumferential direction.

[0014] For example, the insulator may include a first end positioned toward one end in the winding axis direction of the electrode assembly; and a second end positioned toward the bottom member.

[0015] For example, the central hole extension may be recessed along the central axis direction from the first end.

[0016] For example, the central hole extension may be symmetrical with respect to the central axis of the insulator and may be provided with a constant width along the radial outer side.

[0017] For example, the insulator may be configured such that, as the internal pressure of the battery can increases, the central hole expansion portion breaks outwardly in a radial direction from a point extending from the inner surface, and at the same time, the inner surface of the insulator is lifted along the central axis direction to expand the size of the central hole.

[0018] For example, the size of the center hole may be configured to expand along the radial direction from the center hole to at least the point where the center hole extension is formed, as the internal pressure of the battery can increases.

[0019] For example, the battery cell further includes an electrode terminal electrically connected to the second electrode through a through hole formed in the bottom member, and the insulator may be formed as an insulating member configured to insulate the bottom member from one end in the winding axis direction of the electrode assembly electrically connected to the electrode terminal.

[0020] For example, the battery can includes a vent portion configured to break in the bottom member as the internal pressure of the battery can increases, and as the internal pressure of the battery can increases, a radially inner region is removed from the vent portion and at the same time, a residue of the electrode assembly can be discharged from the center hole of the insulator, which has been expanded in size.

[0021] For example, the vent portion may be provided as a closed curve having a predetermined diameter centered on the winding axis of the electrode assembly.

[0022] For example, the insulator includes a plurality of through holes formed along the radial direction spaced apart from the central hole, and at least some of the plurality of through holes may be positioned radially inward from the vent portion.

[0023] For example, the extension line extending along the radial direction of the central hole expansion portion with respect to the central axis of the insulator may not overlap with the extension line extending along the radial direction of the plurality of through portions.

[0024] For example, the insulator may further include at least one damper portion that is inserted through the opening of the battery can and configured such that the outer surface of the insulator in the direction of the central axis is deformed while in contact with the inner surface of the side wall member in the direction of the axis.

[0025] For example, the insulator may be formed such that the outer diameter of the insulator is longer at the location where the damper part is formed along the circumferential direction than at the remaining location.

[0026] For example, the outer diameter of the insulator at the location where the damper part is formed can be reduced as the outer surface of the insulator in the direction of the central axis contacts the inner surface of the side wall member in the direction of the axis.

[0027] For example, the insulator may include a plurality of through holes formed along the radial direction spaced apart from the central hole, and the plurality of through holes may be formed along the radial direction at a location where the damper part is not formed along the circumferential direction.

[0028] In addition, the present invention provides an insulator interposed between one end of an electrode assembly in the direction of the winding axis, in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis, and a bottom member of a battery can accommodating said electrode assembly for electrical insulation, the insulator comprising: a central hole formed along the direction of the central axis; and a central hole extension formed by being recessed in the direction of the central axis in a portion of the outer circumference of said central hole and extending along the radial direction.

[0029] For example, the center hole expansion portion may be formed radially from the center hole, extending from the inner surface of the center axis of the insulator, and may be configured to expand the size of the center hole by causing the center hole expansion portion to break outward from the point extending from the inner surface due to a pressure greater than a certain amount applied in the direction of the center axis.

[0030] For example, the insulator may include a plurality of through holes formed along the radial direction spaced apart from the central hole.

[0031] For example, at least some of the plurality of through holes are positioned adjacent to the inner surface of the central axis of the insulator in the radial direction rather than the outer surface of the central axis of the insulator, and the extension line extending along the radial direction of the central hole expansion part with respect to the central axis may not overlap with the extension line extending along the radial direction of the plurality of through holes.

[0032] In addition, the present invention provides a battery pack comprising a battery cell according to the present invention.

[0033] In addition, the present invention provides a vehicle equipped with at least one battery pack according to the present invention.

[0034] A battery cell and an insulator applied thereto according to various embodiments of the present invention, and a battery pack and a vehicle including the same, have the effect of maintaining an insulation function and being able to break more efficiently when the battery cell vents.

[0035] In addition, the battery cell according to various embodiments, the insulator applied thereto, and the battery pack and automobile including the same have the effect of maximizing the jelly-roll discharge amount when venting the battery cell.

[0036] In addition, the battery cell according to various embodiments, the insulator applied thereto, and the battery pack and automobile including the same have the effect of enabling internal residue to be smoothly ejected.

[0037] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below.

[0038] FIG. 1 is a schematic diagram showing a battery cell according to one embodiment of the present invention.

[0039] FIGS. 2 and FIGS. 3 are schematic diagrams showing the state before and after lamination of the first electrode, the second electrode, and the separator for fabricating the electrode assembly of the battery cell of FIG. 1.

[0040] Figure 4 is a schematic diagram showing an electrode assembly fabricated by winding the laminate of Figure 3 into a jelly-roll shape.

[0041] Figure 5 is a side cross-sectional view of the battery cell of Figure 1.

[0042] Figure 6 is a schematic diagram showing an insulator applied to the battery cell of Figure 1.

[0043] Figure 7 is a side cross-sectional view of the insulator of Figure 6.

[0044] FIG. 8 is a diagram illustrating the direction in which the insulator of FIG. 6 is interposed between the electrode assembly of the battery cell of FIG. 1 and the battery can.

[0045] Figures 9 and 10 are drawings to explain the process of the insulator of Figure 6 rupturing due to a certain pressure.

[0046] Fig. 11 is a partial enlarged view of Fig. 5.

[0047] FIG. 12 is a drawing to explain the appearance of the electrode assembly being discharged when the vent portion of the battery cell of FIG. 1 is broken.

[0048] Fig. 13 is a top view of the battery cell of Fig. 1.

[0049] FIG. 14 is a schematic diagram showing an insulator of another embodiment applied to the battery cell of FIG. 1.

[0050] Figure 15 is a drawing to explain how the outer diameter changes as the insulator of Figure 14 is inserted into the battery can of the battery cell of Figure 1.

[0051] FIG. 16 is a schematic diagram showing a battery pack including a battery cell of the present invention.

[0052] FIG. 17 is a schematic diagram showing a vehicle equipped with at least one battery pack of the present invention.

[0053] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0054] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0055] In addition, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar configurations are omitted, and the focus is on the differences.

[0056] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0057] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0058] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0059] Singular expressions used in this specification include plural expressions unless the context clearly indicates otherwise. In this application, terms such as "composed of" or "comprising" should not be interpreted as necessarily including all of the various components or steps described in the specification, and should be interpreted as meaning that some of the components or steps may be omitted or additional components or steps may be included.

[0060] Throughout the specification, when "A and / or B" is used, it may mean A, B, or A and B unless specifically stated otherwise.

[0061] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in this specification, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art to which this invention pertains that they may vary depending on the position or arrangement, rotation, or position of the observer of the object in question.

[0062] The present invention may be implemented in the following embodiments, each independently. Furthermore, the present invention may be implemented in combination of two or more of the following embodiments. Each of the following embodiments may not only be implemented independently but may also be freely combined with one another.

[0063] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of an electrode assembly wound in a jelly roll shape is referred to as the winding axis direction. The direction surrounding the winding axis of the electrode assembly is referred to as the circumferential direction, and the direction in which the electrode assembly is wound along the winding axis is referred to as the winding direction. Furthermore, the direction moving away from or closer to the winding axis of the electrode assembly is referred to as the radial direction.

[0064]

[0065] First, a schematic structure of a battery cell (1) according to one embodiment of the present invention will be described.

[0066] FIG. 1 is a schematic diagram showing a battery cell (1) according to an embodiment of the present invention, FIG. 2 and FIG. 3 are schematic diagrams showing the state before and after lamination of the first electrode (21), the second electrode (22), and the separator (28) for manufacturing the electrode assembly (20) of the battery cell (1) of FIG. 1, FIG. 4 is a schematic diagram showing an electrode assembly (20) manufactured by winding the laminate of FIG. 3 into a jelly-roll shape, FIG. 5 is a side cross-sectional view of the battery cell (1) of FIG. 1.

[0067] The battery cell (1) may be a cylindrical battery cell. For example, the battery cell (1) may be a cylindrical battery cell in which the ratio of the form factor (defined as the ratio of the diameter of the cylindrical battery cell to the height, i.e., the ratio of the diameter to the height) is greater than approximately 0.4.

[0068] Here, the form factor may refer to a value representing the diameter and height of a cylindrical battery cell. The cylindrical battery cell may be a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, or a 46800 cell by applying the numerical value representing the form factor. Here, the first two digits represent the diameter of the cell, the next two digits represent the height of the cell, and the last digit 0 indicates that the cross-section of the cell is circular.

[0069] Additionally, the battery cell (1) may be a cylindrical battery cell, for example, having a form factor ratio (ratio of diameter along the radial direction to height along the core axis direction) greater than approximately 0.4. For example, the diameter of the battery cell (1) may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the battery cell (1) may be, for example, 46110, 4875, 48110, 4880, or 4680.

[0070] However, the shape of the battery cell (1) according to the present invention is not limited by the above and can be applied to batteries of other shapes. For example, it can be applied to prismatic batteries.

[0071] Referring to FIGS. 1 to 5, the battery cell (1) according to the present embodiment mainly comprises a battery can (10), an electrode assembly (20), a cap (40), and an insulator (50).

[0072] The battery can (10) may be a cylindrical structure for a cylindrical battery cell. In this case, a side wall member (11) may form the side of the cylinder of the battery can (10), and a bottom member (12) may be connected to the side wall member (11) to form one end of the cylinder. That is, the bottom member (12) may be a closed part of the battery can (10), and the other end of the battery can (10) facing the bottom member (12) may be open to form an opening.

[0073] The bottom member (12) may be in the shape of a disc with a through hole formed in the center, and the side wall member (11) may be in the shape of a cylinder surrounding the bottom member (12) and having a constant radius along the circumferential direction. The battery can (10) including the bottom member (12) and the side wall member (11) may be a member formed by a deep drawing process of a metal sheet having nickel plated on the surface of steel. Of course, the materials of the bottom member (12) and the side wall member (11) are not limited to this.

[0074] The battery cell (1) can accommodate an electrode assembly (20) inside the battery can (10) through an opening of the battery can (10).

[0075] The electrode assembly (20) may be configured such that the first electrode (21) and the second electrode (22) and the separator (28) interposed between them are wound around a winding axis.

[0076] The electrode assembly (20) after winding is completed may be in the form of a jelly-roll. The outer shape of the electrode assembly (20) along the circumferential direction may be circular. However, the structure of the electrode assembly (20) is not limited by the embodiment and may have a winding structure well known in the art.

[0077] The first electrode (21), the second electrode (22), and the separator (28) may each have a predetermined width along the winding axis direction and be formed to extend a predetermined length along the winding direction. The first electrode (21) may be an anode plate, and the second electrode (22) may be a cathode plate. Of course, the opposite may also be true.

[0078] The first electrode (21) and the second electrode (22) may be manufactured in the form of a sheet. The first electrode (21) and the second electrode (22) may be configured such that an active material layer (25) is applied to at least a portion of the surface of the metal foil (23). The first electrode (21) and the second electrode (22) may have a retaining portion (24) region where the active material layer (25) is applied and a non-retaining portion (26) region where the active material layer (25) is not applied.

[0079] The uncoated portion (26) can be exposed to the outside of the separator (28) while forming a plurality of winding turns based on the winding axis of the electrode assembly (20), and can be used as an electrode tab itself. That is, the positive plate and the negative plate may each include an uncoated portion (26) in which no active material is coated at the long side end in the direction of the winding axis. In addition, the uncoated portions (26) of the first electrode (21) and the second electrode (22) may be configured to face opposite directions in the direction of the winding axis. The uncoated portion (26) of the first electrode (21) may be housed inside the battery can (10) so that it is located at one end in the direction of the winding axis, and the uncoated portion (26) of the second electrode (22) may be located at the other end in the direction of the winding axis. Here, the positive active material coated on the positive plate and the negative active material coated on the negative plate may be used without limitation as long as they are active materials known in the art.

[0080] Also, the separator (28) may be a porous polymer film, for example, a porous polymer film made of a polyolefin-based polymer such as an ethylene homopolymer, a propylene homopolymer, an ethylene / butene copolymer, an ethylene / hexene copolymer, an ethylene / methacrylate copolymer, etc., used alone or in a laminated form. As another example, the separator may be a conventional porous nonwoven fabric, for example, a nonwoven fabric made of high-melting-point glass fibers, polyethylene terephthalate fibers, etc.

[0081] At least one surface of the separator (28) may include a coating layer of inorganic particles. Additionally, it is possible for the separator (28) itself to be composed of a coating layer of inorganic particles. The particles constituting the coating layer may have a structure combined with a binder such that interstitial volume exists between adjacent particles.

[0082] This non-removable part (26) can itself function as an electrode tab.

[0083] The unwound portion (26) can form multiple flag-shaped notching tabs (27) by forming notches at predetermined intervals along the winding direction. The multiple notching tabs (27) may be in the shape of an isosceles trapezoid arranged along the winding direction. However, they are not limited thereto and may be in various shapes such as a semicircle, semi-ellipse, triangle, rectangle, parallelogram, etc.

[0084] Additionally, a plurality of notching tabs (27) can be flattened by bending them radially in the electrode assembly (20). Additionally, the notching tabs (27) can be bent radially inward or outward in the electrode assembly (20).

[0085] Additionally, multiple notching tabs (27) may be folded one by one during the process of forming a jelly-roll type electrode assembly (20). Alternatively, the notching tabs (27) may be folded all at once after forming the jelly-roll type electrode assembly (20).

[0086] In this way, the notching tabs (27) of the first electrode (21) and the notching tabs (27) of the second electrode (22), which are folded and stacked in the radial direction, can each provide a plane that is substantially perpendicular to the winding axis direction at both ends of the winding axis direction of the electrode assembly (20).

[0087] The cap (40) may be configured to cover the opening of the battery can (10). By doing so, the battery cell (1) is sealed, the internal electrolyte and electrode assembly (20) are protected from the external environment, and the long-term performance of the battery cell (1) can be maintained. The joint point between the opening of the battery can (10) and the cap (40) may be joined by welding. For example, the cap (40) may be joined to the battery can (10) using butt welding. However, the battery can (10) and the cap (40) may be joined by other joining methods other than welding, and the joining method is not limited to this.

[0088] The cap (40) is provided with a conductive material, and the thickness of the cap (40) can be designed to provide sufficient strength to prevent deformation in a high temperature or high pressure environment and to ensure durability to prevent leakage of the internal electrolyte.

[0089] An insulator (50) may be interposed between one end of the electrode assembly (20) in the winding axis direction and the bottom member (12) to prevent contact between the second electrode (22) and the battery can (10). The insulator (50) may include an insulating material. A more detailed structure of the insulator (50) will be described below.

[0090]

[0091] FIG. 6 is a schematic diagram showing an insulator (50) applied to a battery cell (1) of FIG. 1, FIG. 7 is a side cross-sectional view of the insulator (50) of FIG. 6, and FIG. 8 is a diagram for explaining the direction in which the insulator (50) of FIG. 6 is interposed between the electrode assembly (20) of the battery cell (1) of FIG. 1 and the battery can (10).

[0092] Referring to FIGS. 6 to 8, the insulator (50) includes a center hole (51) and a center hole extension (52).

[0093] The center hole (51) may be located approximately in the center of the insulator (50). The center hole (51) may be open in a perforated form having a predetermined diameter in the center. This provides a discharge path for the internal gas and the electrode assembly (20) during venting.

[0094] The center hole expansion portion (52) may be designed to be recessed in the direction of the central axis in a portion of the outer circumference of the center hole (51) and extended along the radial direction, and may be provided as at least one along the outer circumference. This center hole expansion portion (52) may be configured to expand the size of the center hole (51) according to the increase in pressure inside the battery cell (1) during venting.

[0095] Accordingly, the battery cell (1) of the present embodiment can simultaneously optimize internal pressure relief and discharge efficiency by ensuring that the stress concentration occurring in the center hole expansion portion (52) is directly connected to the expansion of the center hole (51).

[0096] Additionally, the center hole (51) surrounds the central axis of the insulator (50), and the inner surface (501) of the insulator (50) can be defined based on this. That is, the center hole (51) forms an open area formed along the central axis within the insulator (50) and can be designed to be aligned with the winding axis of the electrode assembly (20).

[0097] The center hole expansion portion (52) can be designed to extend or expand radially outward from the inner surface (501) of the insulator (50). For example, the center hole expansion portion (52) can be designed to gradually expand or contract in the circumferential direction as it moves radially outward from the starting point of the center hole expansion portion (52), and can also be designed as a groove portion with a constant width.

[0098] The central hole extension (52) can form a step on the inner surface (501) of the insulator (50). Here, the step can be implemented as a stepped change or a protruding shape at specific points along the circumferential direction on the inner surface (501) of the insulator (50). The shape of such a step can be symmetrical with respect to the central axis (A), and the height and width of the step can be adjusted according to the design purpose.

[0099] Thus, stress concentration is induced in the central hole expansion section (52) during venting, so that when pressure exceeding a certain level is applied in the direction of the central axis (A), the expansion of the central hole (51) can be carried out smoothly. In addition, the radially arranged central hole expansion section (52) ensures uniform stress distribution and expansion efficiency, and can relieve internal pressure of the battery cell (1) and maximize the discharge amount of internal residue.

[0100] The central hole extension (52) can be designed to easily break at an intended location by inducing stress concentration when the internal pressure of the battery cell (1) increases.

[0101] Additionally, the insulator (50) of the present embodiment may have a first end (503) positioned toward one end of the winding axis direction of the electrode assembly (20) and a second end (504) positioned toward the bottom member (12).

[0102] As an example, the center hole expansion portion (52) may be designed to be recessed by a predetermined depth (d1) along the direction of the central axis (A) from the first end portion (503). For example, the first end portion (503), which has a step formed along the circumferential direction on the inner surface (501) of the insulator (50), may be positioned toward the electrode assembly (20) and inserted into the battery can (10) while in contact with the side wall member (11). Thus, when the internal pressure of the battery cell (1) increases, the structure is such that stress is further concentrated in the center hole expansion portion (52), which is provided as a relatively concave area from the first end portion (503), and accordingly, the insulator (50) can be broken more easily along the center hole expansion portion (52).

[0103] However, the arrangement direction is not limited to this, and the center hole expansion portion (52) may be designed to be recessed by a predetermined depth (d1) along the direction of the center axis (A) from the second end portion (504).

[0104] As such, the insulator (50) of the present embodiment can adjust the fracture location and stress concentration point through the shape of the recessed central hole expansion portion (52) based on the central axis (A), and can respond to various design conditions. This structure can be implemented through precision machining technology in the manufacturing process and can be optimized according to the strength and flexibility of the material.

[0105] Accordingly, the battery cell (1) of the present embodiment can not only provide a physical expansion function of the center hole (51), but also induce a stress concentration effect in a specific direction.

[0106]

[0107] FIGS. 9 and FIGS. 10 are drawings to explain the process of the insulator (50) of FIG. 6 bursting due to a certain pressure.

[0108] Referring to FIGS. 9 and 10, an insulator (50) as an example may be configured such that a center hole expansion portion (52) forming a step in the circumferential direction is fractured, and a tearing gradually extends along the radial direction from the inner surface (501) of the insulator (50), thereby rapidly expanding the size of the center hole (51). This facilitates the discharge of internal residue or gas when internal pressure rises, and contributes to minimizing unexpected structural damage or deformation of parts.

[0109] In the insulator (50) of the present embodiment, the center hole expansion portion (52) extends from the inner surface (501) of the center hole (51), so that when a certain pressure is applied in the direction of the center axis (A), the center hole expansion portion (52) extending from the inner surface (501) of the insulator (50) may be intentionally ruptured along the radial direction. At the same time, it may be configured to expand the size of the center hole (51) by being lifted along the direction of the center axis (A) to at least the point where the center hole expansion portion (52) is formed along the radial direction. For example, the insulator (50) may be lifted toward the second end (504) along the direction of the center axis (A) to expand the inner diameter of the center hole (51) to have a predetermined diameter (d2). By doing so, the size of the center hole (51) is expanded, which not only allows internal residues to be smoothly discharged during the venting process but also contributes to maximizing venting performance by dynamically securing a discharge path.

[0110] Accordingly, the battery cell (1) of the present embodiment can rapidly relieve internal pressure by utilizing a stress concentration and controlled fracture mechanism according to the shape of the central hole expansion portion (52), and can improve the safety of the secondary battery.

[0111]

[0112] FIG. 11 is a partial enlarged view of FIG. 5, and FIG. 12 is a drawing to explain the appearance of the electrode assembly (20) being discharged after the vent portion (16) of the battery cell (1) of FIG. 1 is broken.

[0113] Referring to FIGS. 11 and 12, a through hole may be formed in the bottom member (12) of the battery can (10) of the battery cell (1) of the present embodiment, and an electrode terminal (13) may be fitted into it. The electrode terminal (13) may be fixed by riveting to the bottom member (12) with a terminal gasket (14) interposed therein. The terminal gasket (14) is interposed between the electrode terminal (13) and the bottom member (12) to seal the inside of the battery can (10) to prevent leakage of the electrolyte and to electrically insulate the electrode terminal (13) and the bottom member (12).

[0114] However, the method of connecting the electrode terminal (13) and the bottom member (12) is not limited to this. For example, if there is a structure that can seal the space between the electrode terminal (13) and the bottom member (12) and electrically insulate the electrode terminal (13) and the bottom member (12), various other fixing methods, such as a bolt-nut connection method, a glass seal method, or a chrome coating & PP-MAH heat bonding method, can also be applied.

[0115] At this time, the insulator (50) may be formed as an insulating member configured to insulate one end of the electrode assembly (20) electrically connected to the electrode terminal (13) in the winding axis direction, for example, between the current collector plate (31) electrically connected to the second electrode (22) and the bottom member (12). By doing so, the insulator (50) can prevent an electrical short circuit inside the battery cell (1).

[0116] The battery can (10) of the present embodiment may include a vent portion (16) configured to break as the internal pressure of the battery can (10) increases in the bottom member (12).

[0117] The vent section (16) is configured to open at a certain pressure along the designed breakage structure. Thus, when the internal pressure of the battery can (10) exceeds the breakage pressure, the vent section (16) breaks, thereby releasing internal gas in the upward direction along the winding axis, which prevents the battery cell (1) from exploding.

[0118] The center hole expansion portion (52) may be positioned radially inward from the vent portion (16) with respect to the central axis (A) of the insulator (50). That is, the center hole expansion portion (52) may be designed to be located within the area where the vent portion (16) is removed after the vent portion (16) is broken. This arrangement allows the center hole expansion portion (52) to be additionally expanded according to internal pressure at the same time that the vent portion (16) is broken and an area having a predetermined diameter is removed, thereby maximizing the discharge efficiency of the electrode assembly (20).

[0119] In addition, by positioning the central axis (A) of the insulator (50) and the winding axis of the electrode assembly (20) on the same line, the alignment of the electrode assembly (20) can be maintained and a stable discharge path can be secured during venting. As a result, not only electrical insulation function but also structural stability of the battery cell (1) and venting efficiency can be achieved simultaneously.

[0120] In the battery cell (1) of the present embodiment, as the internal pressure of the battery can (10) increases, the radially inner region from the vent portion (16) in the bottom member (12) is removed, and at the same time, the size of the center hole (51) of the insulator (50) is expanded by tearing radially from the inner surface (501) of the insulator (50) through the center hole expansion portion (52) located within the removed region. In this process, the center axis (A) of the insulator (50) and the winding axis of the electrode assembly (20) are located on the same line, so that the residue of the electrode assembly (20) can be efficiently and sufficiently discharged in the direction of the center axis (A) through the expanded center hole (51) and the removed bottom member (12).

[0121] Accordingly, the battery cell (1) of the present embodiment rapidly relieves internal pressure during the venting process, and the expansion of the vent portion (16) and the center hole (51) operate in conjunction to smoothly discharge residue and gas from the electrode assembly (20). In particular, the removed area of ​​the vent portion (16) forms a discharge path, and the discharge of the electrode assembly (20) can be further maximized due to the expansion of the center hole (51) of the insulator (50), thereby maximizing the safety of the battery cell (1).

[0122]

[0123] FIG. 13 is a top view of the battery cell (1) of FIG. 1, FIG. 14 is a schematic diagram showing an insulator (50a) of another embodiment applied to the battery cell (1) of FIG. 1, and FIG. 15 is a diagram explaining how the outer diameter of the insulator (50a) of FIG. 14 changes as it is inserted into the battery can (10) of the battery cell (1) of FIG. 1.

[0124] Referring to FIGS. 13 to 15, the vent portion (16) of the present embodiment may be formed outwardly spaced from the electrode terminal (13) along the radial direction. For example, the vent portion (16) may be provided as a closed curve spaced outwardly in the radial direction around the winding axis of the electrode assembly (20). Through this, when the internal pressure of the battery cell (1) rises above a certain level, the vent portion (16) is intentionally broken, and a closed curve region having a predetermined diameter (d3) is removed so that internal gas and residue of the electrode assembly (20) can be smoothly discharged.

[0125] The insulator (50a) of the present embodiment may have a plurality of through holes (53), and at least some of these plurality of through holes (53) may be configured to be formed radially inward from the vent portion (16).

[0126] A plurality of through holes (53) are formed radially outwardly spaced from the center hole (51) and can be formed radially outwardly from the center hole expansion portion (52) with respect to the center axis. By doing so, an additional path is formed for the discharge of gas generated inside the battery cell (1), thereby more effectively supporting pressure relief during venting.

[0127] As an example, the insulator (50a) can be divided into a region (R1) positioned radially inward and a region (R2) positioned radially outward with respect to the central axis, compared to a vent portion (16) having a predetermined diameter (d3) based on the dotted line shown in FIG. 13.

[0128] At this time, at least some of the plurality of through holes (53) may be configured to be positioned in an area (R1) located radially inward from the vent portion (16). Thus, the plurality of through holes (53) may be arranged at relatively uniform intervals along the radial direction, thereby enabling the uniform distribution of internal pressure during venting through diversification of the gas discharge path. Additionally, the pressure difference that occurs while the internal gas travels along the discharge path may be minimized, thereby reducing resistance during the gas discharge process.

[0129] Additionally, the insulator (50a) can be configured so that the extension line (E1) extended along the radial direction of the center hole expansion part (52) with respect to the center axis does not overlap with the extension line (E2) extended along the radial direction of the plurality of through parts (53).

[0130] For example, the central hole expansion part (52) is designed to efficiently break when the internal pressure of the battery can (10 in FIG. 15) exceeds a certain threshold, whereas the multiple through-holes (53) are designed to smoothly discharge internal gas to the outside during the venting process. Since there is a possibility that the pressure or heat generated during gas discharge may affect the breaking structure of the central hole expansion part (52) when these two structures overlap, the gas discharge path (multiple through-holes-53) and the extension line of the breaking structure (central hole expansion part-52) are designed so that they do not overlap, thereby allowing each function to operate independently without mutual interference.

[0131] Additionally, as an example, the insulator (50a) may additionally include at least one damper part (54).

[0132] The damper portion (54) is inserted through the opening of the battery can (10) of the battery cell (1), and can be configured so that the outer surface (502) in the direction of the central axis of the insulator (50a) is deformed while in contact with the inner surface (111) in the direction of the side wall member (11). To this end, in the insulator (50a) of the present embodiment, the outer diameter of the insulator (50a) at the location where the damper portion (54) is formed along the circumferential direction may be formed to be longer by a predetermined length (d4) than at the remaining locations.

[0133] The insulator (50a) can be fixed to each other by being in close contact with the central axis direction outer surface (502) of the insulator (50a) as the damper portion (54) is formed, while the outer diameter of the insulator (50a) is reduced.

[0134] Multiple through holes (53) can be formed radially at locations where the damper section (54) is not formed along the circumferential direction. This allows the gas discharge path and the deformation structure of the damper section (54) to function independently without mutual interference.

[0135] Through this, the plurality of through holes (53) provide an efficient path to quickly discharge gas generated inside the battery cell (1) to the outside, and facilitate the gas flow during the venting process. At the same time, the damper part (54) strengthens the close contact and fixation between the insulator (50a) and the side wall member (11) within the battery can (10), and can maintain structural stability.

[0136] Accordingly, the battery cell (1) of the present embodiment can contribute to simultaneously securing venting performance and structural safety while maximizing the function of each element through the arrangement and design structure of a plurality of through-holes (53) and damper parts (54).

[0137]

[0138] FIG. 16 is a schematic diagram showing a battery pack (P) equipped with a battery cell (1) of the present invention, and FIG. 17 is a schematic diagram showing a vehicle (V) equipped with a battery pack (P) of the present invention.

[0139] Referring to FIG. 16, a battery pack (P) according to one embodiment of the present invention may have a pack case (C) configured to accommodate a battery cell (1) and may further include various other components of a battery pack known at the time of filing the present invention. For example, a battery pack (P) according to one embodiment of the present invention may further include components such as a current sensor, a fuse, and a service plug.

[0140] Additionally, referring to FIG. 17, a vehicle (V) according to one embodiment of the present invention may include one or more battery packs (P) according to the present invention. Furthermore, a vehicle (V) according to one embodiment of the present invention may include various other components included in the vehicle (V) in addition to the battery packs (P). For example, a vehicle (V) according to one embodiment of the present invention may include, in addition to the battery packs (P) according to one embodiment of the present invention, a vehicle body, a motor, an electronic control unit (ECU), or other control devices.

[0141] In addition, the battery pack (P) according to one embodiment of the present invention can be applied to various types of energy storage devices or power sources, and it is also possible to equip it in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to the vehicle (V).

[0142]

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

[0144] [Explanation of Symbols] 1: Battery Cell

[0145] 10: Battery can

[0146] 11: Sidewall member

[0147] 111: If you give it to me

[0148] 12: Floor member

[0149] 13: Electrode terminal

[0150] 14: Terminal gasket

[0151] 16: Banting Department

[0152] 20: Electrode assembly

[0153] 21: First electrode

[0154] 22: Second electrode

[0155] 23: Metal foil

[0156] 24: Active material layer

[0157] 25: Maintenance Department

[0158] 26: Mujibu

[0159] 27: Electrode tab

[0160] 28: Separator

[0161] 40: Cap

[0162] 50, 50a: Insulator

[0163] 501: If you give it to me

[0164] 502: Outsourcing

[0165] 503: First section

[0166] 504: Second section

[0167] 51: Central Hall

[0168] 52: Central hall extension

[0169] 53: Communion Study

[0170] 54: Damper section

[0171] A: Central axis

[0172] C: Pack case

[0173] P: Battery pack

[0174] V: Car

Claims

1. A battery can having a side wall member, a bottom member connected to one axial end of the side wall member, and an opening provided at the other axial end of the side wall member; An electrode assembly received through the opening of the battery can, wherein the first electrode and the second electrode and the separator interposed between them are wound around a winding axis; A cap covering the opening of the battery can; and A battery cell characterized by comprising an insulator interposed between one end of the electrode assembly in the winding axis direction and the bottom member, the insulator having a center hole formed along the center axis direction, and at least one center hole extension portion that is recessed in the center axis direction in a portion of the outer circumference of the center hole and extends along the radial direction.

2. In Paragraph 1, The above central hole is, Defines the inner surface of the insulator surrounding the central axis of the insulator, and The above-mentioned central hole expansion part is, A battery cell characterized by extending along the radial direction from the inner surface of the insulator and being formed radially outward from the center hole, and forming a step on the inner surface of the insulator along the circumferential direction.

3. In Paragraph 1, The above insulator is, A first end portion positioned toward one end portion in the winding axis direction of the electrode assembly; and It includes a second end portion positioned toward the floor member, and The above-mentioned central hole expansion part is, A battery cell characterized by being recessed along the central axis direction from the first end portion.

4. In Paragraph 1, The above-mentioned central hole expansion part is, A battery cell characterized by being symmetrical with respect to the central axis of the insulator and having a constant width along the radial outer side.

5. In Paragraph 2, The above insulator is, A battery cell characterized by being configured such that, as the internal pressure of the battery can increases, the central hole expansion portion is fractured radially outward from a point extending from the inner surface, and at the same time, the inner surface of the insulator is lifted along the central axis direction to expand the size of the central hole.

6. In Paragraph 5, The size of the above central hole is, A battery cell characterized by being configured to expand along the radial direction from the center hole to at least the point where the center hole expansion portion is formed, as the internal pressure of the battery can increases.

7. In Paragraph 1, It further includes an electrode terminal electrically connected to the second electrode through a through hole formed in the bottom member, and The above insulator is, A battery cell characterized by being formed with an insulating member configured to insulate one end of the electrode assembly in the winding axis direction, which is electrically connected to the electrode terminal, from the bottom member.

8. In Paragraph 1, The above battery can is, The above bottom member includes a vent portion configured to break as the internal pressure of the battery can increases, and A battery cell characterized by the fact that, as the internal pressure of the battery can increases, the radially inner region from the vent portion is removed, and at the same time, the residue of the electrode assembly is discharged from the center hole of the insulator, which has been expanded in size.

9. In Paragraph 8, The above vent part is, A battery cell characterized by being provided as a closed curve having a predetermined diameter centered on the winding axis of the electrode assembly.

10. In Paragraph 8, The above insulator is, It includes a plurality of through holes formed along the radial direction spaced apart from the above-mentioned central hole, and At least some of the above plurality of through holes, A battery cell characterized by being positioned radially inward from the above-mentioned vent portion.

11. In Paragraph 10, The above insulator is, A battery cell characterized in that the extension line extending along the radial direction of the central hole expansion portion with respect to the central axis does not overlap with the extension line extending along the radial direction of the plurality of through portions.

12. In Paragraph 1, The above insulator is, A battery cell characterized by further including at least one damper member inserted through the opening of the battery can, configured such that the outer surface of the insulator in the direction of the central axis contacts the inner surface of the side wall member in the direction of the axis and is deformed.

13. In Paragraph 12, The above insulator is, A battery cell characterized in that the outer diameter of the insulator is longer at the location where the damper part is formed along the circumferential direction than at the remaining location.

14. In Paragraph 12, The above insulator is, A battery cell characterized by the outer surface of the insulator in the direction of the central axis contacting the inner surface of the side wall member in the direction of the axis, and the outer diameter of the insulator at the position where the damper part is formed being reduced.

15. In Paragraph 12, The above insulator is, It includes a plurality of through holes formed along the radial direction spaced apart from the above-mentioned central hole, and The above plurality of through holes are, A battery cell characterized by being formed along the radial direction at a location where the damper portion is not formed along the circumferential direction.

16. An insulator interposed between one end in the direction of the winding axis of an electrode assembly, in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis, and a bottom member of a battery can accommodating said electrode assembly for electrical insulation. A central hole formed along the direction of the central axis; and An insulator characterized by including a central hole extension formed by being recessed in the direction of the central axis in a portion of the outer circumference of the central hole and extending along the radial direction.

17. In Paragraph 16, The above-mentioned central hole expansion part is, An insulator characterized by being formed radially outward from the central hole, extending from the inner surface of the central axis of the insulator, and configured such that the central hole expansion portion is fractured outward in the radial direction from the point extending from the inner surface due to a pressure greater than a certain amount applied in the direction of the central axis, thereby expanding the size of the central hole.

18. In Paragraph 16, The above insulator is, It includes a plurality of through holes formed along the radial direction spaced apart from the above-mentioned central hole, and At least some of the above plurality of through holes, It is positioned in the radial direction adjacent to the inner surface of the central axis of the insulator rather than the outer surface of the central axis of the insulator, and An insulator characterized in that the extension line extending along the radial direction of the central hole expansion portion with respect to the central axis does not overlap with the extension line extending along the radial direction of the plurality of through portions.

19. As a battery pack, A battery pack characterized by including a battery cell according to any one of claims 1 to 15.

20. As a vehicle, A vehicle equipped with at least one battery pack according to claim 19.

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