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

Abstract

The present invention provides a battery cell, an insulator applied thereto, and a battery pack and a vehicle comprising same. The battery cell comprises: 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 accommodated through the opening of the battery can and having a first electrode, a second electrode, and a separator therebetween, which are wound around a winding axis; an insulator arranged between one end of the electrode assembly in the winding axis direction and the bottom member, having a central hole formed along the central axis direction, and including a central hole expansion part formed in a region closer to the central hole than the outer circumferential surface in the central axis direction with respect to the radial direction; and a cap covering the opening of the battery can.

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. 10-2025-0011584 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 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 a first electrode, a second electrode, and a separator interposed between them are wound around a winding axis; an insulator interposed between one end of the winding axis of the electrode assembly and the bottom member, having a center hole formed along a center axis direction, and including a center hole extension formed in an area adjacent to the center hole relative to the outer surface in the center axis direction with respect to the radial direction; and a cap covering the opening of the battery can.

[0013] For example, the center hole extension may be arranged radially at a position spaced radially outward from the center hole.

[0014] For example, the battery can includes a vent portion configured to break upon an increase in internal pressure of the battery can in the bottom member, and the center hole expansion portion may be positioned radially inward from the vent portion with respect to the center axis of the insulator.

[0015] For example, the central hole defines the inner surface of the insulator surrounding the central axis of the insulator, and the central axis of the insulator and the winding axis of the electrode assembly may be located on the same line.

[0016] For example, the insulator may be configured to expand the size of the central hole as the inner surface of the insulator ruptures and is simultaneously lifted along the central axis direction in response to an increase in the internal pressure of the battery can.

[0017] For example, the insulator may be configured such that, as the internal pressure of the battery can increases, the area between the center hole and the center hole expansion portion ruptures to expand the size of the center hole.

[0018] For example, the size of the center hole may be extended along the radial direction with respect to the center axis of the insulator to a point where at least the outer perimeter of the center hole extension is formed.

[0019] For example, the central hole extension may be formed as an ellipse where the length in the radial direction is longer than the length in the circumferential direction.

[0020] For example, the apparatus 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.

[0021] For example, 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 can be discharged from the central hole of the insulator, which has expanded in size within the removed region.

[0022] 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.

[0023] 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.

[0024] 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.

[0025] For example, the insulator may further include a plurality of peripheral holes formed radially outward from the central hole extension with respect to the central axis.

[0026] For example, the plurality of peripheral holes may be formed along the radial direction at a location where the damper part is not formed along the circumferential direction.

[0027] 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 expansion portion radially arranged and spaced radially inward from said central hole, wherein the region between said central hole expansion portion and said central hole is ruptured by a pressure greater than a certain amount applied in the direction of the central axis to expand the size of said central hole.

[0028] For example, the central hole may be configured to define the inner surface of the insulator surrounding the central axis of the insulator, and to expand in size by being lifted along the central axis direction to a point where at least the outer circumference of the central hole expansion portion is formed, while the inner surface of the insulator ruptures due to pressure exceeding a certain level applied in the direction of the central axis.

[0029] For example, the central hole extension may be formed as an ellipse where the length in the radial direction is longer than the length in the circumferential direction.

[0030] In addition, the present invention provides a battery pack comprising a battery cell according to the present invention.

[0031] In addition, the present invention provides an automobile comprising a battery pack according to the present invention.

[0032] 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.

[0033] 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.

[0034] 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.

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

[0036] FIG. 1 is a schematic diagram showing a battery cell according to one embodiment of the present invention.

[0037] 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.

[0038] Figure 4 is a schematic diagram showing an electrode assembly fabricated by winding the laminate of Figure 3 into a jelly-roll shape.

[0039] Figure 5 is a side cross-sectional view of the battery cell of Figure 1.

[0040] Figure 6 is a schematic diagram showing an insulator applied to the battery cell of Figure 1.

[0041] Figure 7 is a partial enlarged view of Figure 5.

[0042] Figure 8 is a top view of the battery cell of Figure 1.

[0043] Figures 9 and 10 are drawings to explain the process of the insulator of Figure 6 rupturing due to a certain pressure.

[0044] FIG. 11 is a drawing to explain the appearance of the electrode assembly being discharged when the bottom member of the battery cell of FIG. 1 is fractured.

[0045] FIG. 12 is a schematic diagram showing an insulator of another embodiment applied to the battery cell of FIG. 1.

[0046] FIG. 13 is a drawing to explain how the outer diameter changes as the insulator of FIG. 12 is inserted into the battery can of the battery cell of FIG. 1.

[0047] FIG. 14 is a schematic diagram showing a battery pack including a battery cell of the present invention.

[0048] FIG. 15 is a schematic diagram showing a vehicle including a battery pack of the present invention.

[0049] 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.

[0050] 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.

[0051] 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.

[0052] 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.

[0053] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0054] 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.

[0055] 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.

[0056] Throughout the specification, when "A and / or B" is used, it may mean A, B, or A and B unless specifically stated otherwise.

[0057] 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.

[0058] 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.

[0059] 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.

[0060]

[0061] First, a schematic structure of a battery cell (1) according to one embodiment of the present invention will be described.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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).

[0068] 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.

[0069] 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.

[0070] The battery cell (1) can accommodate an electrode assembly (20) inside the battery can (10) through an opening of the battery can (10).

[0071] 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.

[0072] 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.

[0073] 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.

[0074] 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.

[0075] 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.

[0076] 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.

[0077] 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.

[0078] This non-removable part (26) can itself function as an electrode tab.

[0079] 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.

[0080] 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).

[0081] A current collector plate (31) made of a conductive material may be connected to at least one end in the direction of the winding axis of such an electrode assembly (20). The current collector plate (31) is electrically connected to the first electrode (21) and / or the second electrode (22) of the electrode assembly (20), respectively, so that the electrode terminal (13) is connected to the second electrode (22) to have a positive charge and the bottom member (12) is connected to the first electrode (21) to have a negative charge and functions as a negative terminal (15), and vice versa.

[0082] A vent portion (16) for a vent may be provided radially outward from such an electrode terminal (13).

[0083] 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).

[0084] 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).

[0085] 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.

[0086] 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.

[0087] 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.

[0088]

[0089] FIG. 6 is a schematic diagram showing an insulator (50) applied to the battery cell (1) of FIG. 1.

[0090] Referring to FIG. 6, the insulator (50) includes a center hole (51) and a center hole extension (52).

[0091] 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.

[0092] The center hole expansion portion (52) may be provided in the outer perimeter area of ​​the center hole (51) and 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.

[0093] The center hole expansion portion (52) may be formed in an area adjacent to the center hole (51) rather than the outer surface of the insulator (50) in the direction of the center axis, based on the radial direction. For example, among the two areas (R1, R2) divided based on the dotted line shown in FIG. 6, the center hole expansion portion (52) may be formed at a location (R1) adjacent to the center hole (51) rather than the area (R2) adjacent to the outer surface along the radial direction. As an example, the dotted line may be the point where the vent portion (16 in FIG. 5) is formed. By doing so, the stress concentration occurring in the center hole expansion portion (52) is directly connected to the expansion of the center hole (51), thereby allowing internal pressure relief and discharge efficiency to be optimized simultaneously.

[0094] The center hole extension (52) can be arranged radially at a position spaced radially outward from the center hole (51).

[0095] The center hole expansion portion (52) can be arranged radially at a certain distance from the center hole (51) in a radial direction outward. By doing so, stress concentration is induced in the surrounding area surrounding the center hole (51) during venting, thereby allowing the expansion of the center hole (51) to proceed smoothly when the internal pressure of the battery cell (1) increases. The center hole expansion portion (52) arranged radially in this way ensures uniform stress distribution and expansion efficiency, and can relieve the internal pressure of the battery cell (1) and maximize the discharge amount of the electrode assembly (20 in FIG. 5).

[0096] The central hole expansion portion (52) can be designed to induce stress concentration when the internal pressure of the battery cell (1) increases, so that it can easily break at an intended location. For example, the central hole expansion portion (52) can be formed in the shape of a through hole of a predetermined size, a thin film (a thin film portion with a thickness smaller than the surroundings), a V-shaped notch, a U-shaped notch, or a slit. However, it is not limited to these examples, and any structure capable of easily tearing or breaking when a certain pressure is reached is sufficient.

[0097] As an example, the center hole extension (52) may be formed as an ellipse where the radial length is longer than the circumferential length. This elliptical structure can be designed to efficiently concentrate stress on the internal pressure of the battery cell (1) generated during venting, thereby facilitating tearing or fracture at specific locations. For example, the elliptical center hole extension (52) may be configured such that stress concentration is maximized at the narrowest point, i.e., the longitudinal end of the ellipse, so that fracture may easily begin due to external force or internal pressure. Once such fracture begins, the tearing gradually expands along the major axis of the ellipse, thereby rapidly expanding the size of the center hole (51).

[0098] Accordingly, the battery cell (1) of the present embodiment can further expand the discharge path of the internal gas and the electrode assembly (20) through the design structure of the central hole expansion part (52), thereby ensuring that the internal pressure is safely relieved during the venting process of the battery cell (1), and that the discharge of the electrode assembly (20 in FIG. 5) is smooth, contributing to minimizing the internal residual pressure. In addition, this ensures rapid responsiveness in the initial stage of venting and can increase safety in dangerous situations such as thermal runaway.

[0099]

[0100] Fig. 7 is a partial enlarged view of Fig. 5, and Fig. 8 is a top view of the battery cell of Fig. 1.

[0101] Hereinafter, with reference to FIGS. 7 and FIGS. 8, we will examine the specific arrangement structure of the insulator (50) inside the battery cell (1) of the present invention.

[0102] According to the present embodiment, a through hole may be formed in the bottom member (12) of the battery can (10), 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).

[0103] 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.

[0104] 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 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).

[0105] 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).

[0106] 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.

[0107] The vent portion (16) may be formed spaced outward along the radial direction from the electrode terminal (13). For example, the vent portion (16) may be provided as a closed curve having a predetermined diameter (d1) centered on the winding axis of the electrode assembly (20). In this way, when the internal pressure of the battery cell (1) rises above a certain level, the vent portion (16) is intentionally broken, and the closed curve area having the predetermined diameter (d1) is removed, allowing the internal gas and the electrode assembly (20) to be discharged smoothly.

[0108] 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 inside 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 as the vent portion (16) is broken and the area having a predetermined diameter (d1) is removed, thereby maximizing the discharge efficiency of the electrode assembly (20).

[0109] Accordingly, the battery cell (1) of the present embodiment can improve the internal pressure relief of the battery cell (1) and the discharge performance of the electrode assembly (20) during the venting process through the interconnected fracture structure of the vent portion (16) and the central hole expansion portion (52).

[0110] The center hole (51) surrounds the center axis (A) 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 center axis (A) within the insulator (50) and can be designed to be aligned with the winding axis of the electrode assembly (20).

[0111] In this embodiment, 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 but also structural stability of the battery cell (1) and venting efficiency can be achieved simultaneously.

[0112]

[0113] FIGS. 9 and FIGS. 10 are drawings for explaining the process of the insulator (50) of FIG. 6 rupturing due to a certain pressure, and FIG. 11 is a drawing for explaining the appearance of the electrode assembly (20) being discharged after the bottom member (12) of the battery cell (1) of FIG. 1 is broken.

[0114] Referring to FIGS. 9 and 10, the insulator (50) of the present embodiment may be configured such that a central hole expansion portion (52) is positioned adjacent to the central hole (51), so that as the internal pressure of the battery can increases, the inner surface (501) of the insulator (50) is intentionally ruptured and simultaneously lifted along the central axis direction to expand the size of the central hole (51). By doing so, the size of the central 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.

[0115] As an example, the insulator (50) can be designed so that as the internal pressure of the battery can (10) increases, the area between the center hole (51) and the center hole extension (52) is intentionally broken, thereby expanding the size of the center hole (51). In this process, as the area between the center hole extension (52) and the center hole is broken, the area between the center hole extension (52) arranged along the circumferential direction with respect to the center axis is all lifted, thereby effectively expanding the size of the center hole (51).

[0116] As a result, the size of the center hole (51) of the insulator (50) can be extended to the furthest region where the center hole extension (52) is formed along the radial direction with respect to the center axis. For example, it can be extended to the dotted line region shown in FIG. 9, which has a predetermined diameter (d2) with respect to the center axis. This design secures a wider and more efficient discharge path for relieving internal pressure during venting, and can induce smooth discharge of internal gas and the electrode assembly (20).

[0117] Referring to FIG. 11, in the battery cell (1) of the present embodiment, as the internal pressure of the battery can (10) increases through the exemplary central hole expansion portion (52) as described above, the radially inner region from the vent portion (16 in FIG. 8) in the bottom member (12) is removed, and at the same time, the size of the central hole (51) of the insulator (50) located within the removed region is expanded. In this process, the residue of the electrode assembly (20) can be efficiently and sufficiently discharged to the outside through the expanded central hole (51).

[0118] 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).

[0119]

[0120] FIG. 12 is a schematic diagram showing an insulator (50a) of another embodiment applied to the battery cell (1) of FIG. 1, and FIG. 13 is a diagram explaining how the outer diameter of the insulator (50a) of FIG. 12 changes as it is inserted into the battery can (10) of the battery cell (1) of FIG. 1.

[0121] Here, the description of the insulator (50) of the above-described embodiment with reference to FIGS. 6 to 11 may be applied in the same way to the insulator (50a) of the present embodiment in terms of matters common to it, and redundant descriptions are omitted below.

[0122] Referring to FIGS. 12 and 13, the insulator (50a) of the present embodiment may additionally include a plurality of peripheral holes (53) and / or at least one damper part (54).

[0123] A plurality of peripheral holes (53) are formed radially outwardly spaced from the central hole (51) and can be formed radially outwardly from the central hole extension (52) with respect to the central axis. By doing so, an additional path is formed for the discharge of gas generated inside the battery cell (1), thereby supporting pressure relief during venting.

[0124] The damper portion (54) is inserted through the opening of the battery can (10) 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 axial axis 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 (d3) than at the remaining locations.

[0125] 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.

[0126] Multiple peripheral holes (53) may 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.

[0127] Through this, the multiple peripheral 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.

[0128] 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 peripheral holes (53) and damper parts (54).

[0129]

[0130] FIG. 14 is a schematic diagram showing a battery pack (P) equipped with a battery cell (1) according to one embodiment of the present invention, and FIG. 15 is a schematic diagram showing a vehicle (V) equipped with a battery pack (P) according to one embodiment of the present invention.

[0131] A battery pack (P) according to one embodiment of the present invention comprises a pack case (C) capable of accommodating 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.

[0132] In addition, 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 pack (P). For example, a vehicle (V) according to one embodiment of the present invention may include, in addition to the battery pack (P) according to one embodiment of the present invention, a vehicle body, a motor, an electronic control unit (ECU), or other control devices.

[0133] 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).

[0134]

[0135] 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.

[0136] [Explanation of the symbol]

[0137] 1: Battery cell

[0138] 10: Battery can

[0139] 11: Sidewall member

[0140] 111: If you give it to me

[0141] 12: Floor member

[0142] 13: Electrode terminal

[0143] 14: Terminal gasket

[0144] 16: Banting Department

[0145] 20: Electrode assembly

[0146] 21: First electrode

[0147] 22: Second electrode

[0148] 23: Metal foil

[0149] 24: Active material layer

[0150] 25: Maintenance Department

[0151] 26: Mujibu

[0152] 27: Electrode tab

[0153] 28: Separator

[0154] 40: Cap

[0155] 50, 50a: Insulator

[0156] 501: If you give it to me

[0157] 502: Outsourcing

[0158] 51: Central Hall

[0159] 52: Central hall extension

[0160] 53: Peripheral Hall

[0161] 54: Damper section

[0162] A: Central axis

[0163] C: Pack Housing

[0164] P: Battery pack

[0165] 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 including an insulator interposed between one end of the electrode assembly in the winding axis direction and the bottom member, having a center hole formed along the center axis direction, and including a center hole extension formed in an area adjacent to the center hole in the center axis direction with respect to the radial direction.

2. In Paragraph 1, The above-mentioned central hole expansion part is, A battery cell characterized by being radially arranged at a position spaced radially outward from the above-mentioned center hole.

3. In Paragraph 1, The above-mentioned central hole expansion part is, A battery cell characterized by being formed in an elliptical shape where the length in the radial direction is longer than the length in the circumferential direction.

4. 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.

5. 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 The above-mentioned central hole expansion part is, A battery cell characterized by being positioned radially inward from the vent portion with respect to the central axis of the insulator.

6. In Paragraph 1, The above central hole is, A battery cell characterized by defining an inner surface of the insulator surrounding the central axis of the insulator, wherein the central axis of the insulator and the winding axis of the electrode assembly are located on the same line.

7. In Paragraph 6, The above insulator is, A battery cell characterized by being configured such that, as the internal pressure of the battery can increases, the inner surface of the insulator ruptures and is simultaneously lifted along the central axis direction to expand the size of the central hole.

8. In Paragraph 1, The above insulator is, A battery cell characterized by being configured such that, as the internal pressure of the battery can increases, the region between the central hole and the central hole expansion portion ruptures to expand the size of the central hole.

9. In Paragraph 1, The size of the above central hole is, A battery cell characterized by extending along the radial direction relative to the central axis of the insulator to a point where the outer perimeter of the central hole expansion portion is formed.

10. In Paragraph 5, A battery cell characterized by the fact that, 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 is discharged from the central hole of the insulator, which has expanded in size within the removed region.

11. 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.

12. In Paragraph 11, 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.

13. 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.

14. In Paragraph 11, The above insulator is, A battery cell characterized by further including a plurality of peripheral holes formed radially outward from the central hole extension portion based on the central axis.

15. In Paragraph 14, The above plurality of peripheral 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 It includes a center hole extension portion radially arranged and spaced inwardly in the radial direction from the center hole, and An insulator characterized by being configured such that the area between the central hole expansion part and the central hole is ruptured by a pressure greater than a certain amount applied in the direction of the central axis, thereby expanding the size of the central hole.

17. In Paragraph 16, The above central hole is, An insulator characterized by defining an inner surface of the insulator surrounding the central axis of the insulator, and being configured such that when a pressure greater than a certain amount applied in the direction of the central axis causes the inner surface of the insulator to rupture, it is simultaneously lifted along the direction of the central axis to a point where at least the outer circumference of the central hole expansion portion is formed, thereby expanding in size.

18. In Paragraph 16, The above-mentioned central hole expansion part is, An insulator characterized by being formed in an elliptical shape, wherein the length in the radial direction is longer than the length in the circumferential direction.

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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