Current collector, battery cell, battery pack and vehicle comprising battery pack

Abstract

A battery cell according to an embodiment of the present invention comprises: an electrode assembly in which first and second electrodes and a separator interposed therebetween are wound around a winding axis to define a core and an outer peripheral surface, the first electrode comprising a first uncoated portion not coated with an active material in a winding direction; a battery case having an opening on one side and accommodating the electrode assembly through the opening; and a current collector including a support portion disposed on the top of the electrode assembly, a tab coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion and electrically coupled to an inner surface of the battery case, a fracture portion having a lower strength than the surrounding area is provided at a boundary between the support portion and the joint coupling portion.

Description

Technical Field

[0001] The present disclosure relates to a current collector, a battery cell, a battery pack including the battery cell, and a vehicle.

[0002] This application is based upon and claims the benefit of priority from Korean Patent Application No. 10-2023-0077637 filed on June 16, 2023, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

[0003] This application is based upon and claims the benefit of priority from Korean Patent Application No. 10-2024-0030857 filed on March 4, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference.

[0004] This application is based upon and claims the benefit of priority from Korean Patent Application No. 10-2024-0067269 filed on May 23, 2024, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein in its entirety by reference. Background Art

[0005] Secondary batteries, with their high adaptability depending on the product category and electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electric drive sources. These secondary batteries offer the major advantage of significantly reducing fossil fuel use and producing no byproducts from energy use. Consequently, secondary batteries are attracting significant attention as a new energy source that can improve eco-friendliness and energy efficiency.

[0006] The types of secondary batteries currently in widespread use include, for example, lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells (i.e., unit battery cells) is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, a battery pack can be formed by connecting multiple battery cells in series. In addition, a battery pack can be formed by connecting multiple battery cells in parallel according to the required charge and discharge capacity of the battery pack. Therefore, the number of battery cells included in the battery pack can be set in various ways according to the required output voltage and / or charge and discharge capacity.

[0007] At the same time, when heat in battery cells is not properly managed, a phenomenon called thermal runaway can occur, in which the electrochemical cell heats itself in an uncontrollable way, causing the environment to change in a direction that further accelerates temperature changes. Summary of the Invention

[0008] Technical issues

[0009] The present disclosure provides a battery cell, wherein when thermal runaway occurs, a flame generated inside the battery cell can be smoothly discharged.

[0010] Furthermore, the present disclosure prevents the bead portion of the battery cell from being damaged when thermal runaway occurs.

[0011] The present disclosure prevents a pinhole phenomenon from occurring in a crimped portion of a battery cell when thermal runaway occurs.

[0012] However, the technical problems to be solved by the present disclosure are not limited to the above problems, and those skilled in the art can clearly understand other problems not mentioned above from the description of the present disclosure set forth below.

[0013] Technical Solution

[0014] A battery cell according to an embodiment of the present disclosure includes: an electrode assembly including a first electrode and a second electrode and a separator interposed between the first electrode and the second electrode, wherein the first electrode, the second electrode, and the separator are wound around a winding axis to define a core and an outer peripheral surface, wherein the first electrode includes a first uncoated portion that is not coated with an active material layer along the winding direction; a battery case having an opening on one side and configured to accommodate the electrode assembly through the opening; and a current collector including a support portion provided on the electrode assembly, a tab coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion and electrically coupled to an inner surface of the battery case. A fracture portion is provided at a boundary between the support portion and the tab coupling portion, the fracture portion being configured to have lower strength than a surrounding area.

[0015] For example, the fracture portion includes a notch line including a plurality of notches.

[0016] The current collector according to an embodiment of the present disclosure may include a through hole passing through the current collector.

[0017] For example, the through-hole may be located on the notch line.

[0018] According to an embodiment of the present disclosure, the through hole may be located at a center of the boundary between the support portion and the joint coupling portion.

[0019] According to an embodiment of the present disclosure, at least one through hole may be provided on the support portion.

[0020] According to an embodiment of the present disclosure, at least one through hole may be provided on the joint coupling portion.

[0021] According to an embodiment of the present disclosure, the notch line may be configured to have a curved shape.

[0022] According to an embodiment of the present disclosure, the joint coupling portion may be configured to have a greater width than the housing coupling portion.

[0023] According to an embodiment of the present disclosure, the first non-coating portion and the joint coupling portion may be coupled by welding in a radial direction of the electrode assembly.

[0024] For example, a weld bead may be formed between the first uncoated portion and the joint coupling portion.

[0025] The weld beads may form a linear weld pattern extending in a radial direction of the electrode assembly.

[0026] The welding pattern is arranged perpendicular to the notch line.

[0027] For example, the joint coupling portion may be located below a bottom surface of the crimping portion.

[0028] According to an embodiment of the present disclosure, a current collector may include: a support portion provided on an electrode assembly; a joint coupling portion extending from the support portion and coupled to a first uncoated portion; and a case coupling portion extending from the support portion and electrically coupled to an inner surface of a battery case. A fracture portion may be provided at a boundary between the support portion and the joint coupling portion, the fracture portion being configured to be lower in strength than surrounding areas.

[0029] Alternatively, the present disclosure provides a battery pack comprising at least one battery cell according to the above embodiment.

[0030] Furthermore, the present disclosure provides a vehicle including at least one battery pack according to the above-described embodiment.

[0031] Furthermore, the present disclosure provides a battery module, comprising at least one battery cell according to the above embodiment.

[0032] The present disclosure provides an energy storage system, which includes at least one battery module according to the above embodiment.

[0033] According to another embodiment of the present disclosure, a battery cell includes: an electrode assembly, the electrode assembly including a first electrode and a second electrode and a separator interposed between the first electrode and the second electrode, and the first electrode, the second electrode, and the separator are wound around a winding axis to define a core and an outer peripheral surface, wherein the first electrode includes a first uncoated portion that is not coated with an active material layer along the winding direction; a battery case having an opening on one side and configured to accommodate the electrode assembly through the opening; and a current collector, the current collector including a support portion provided on the electrode assembly, a tab coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion and electrically coupled to an inner surface of the battery case. The current collector is provided with a channel or passage configured to discharge flames toward the outside when thermal runaway occurs in the electrode assembly.

[0034] For example, the channel or passage includes a break portion at a boundary between the support portion and the joint coupling portion, the break portion is configured to be lower in strength than a surrounding area, and the break portion includes a notch line including a plurality of notches.

[0035] Beneficial effects

[0036] According to an embodiment of the present disclosure, when thermal runaway occurs, the flame generated inside the battery cell can be smoothly discharged.

[0037] According to the embodiments of the present disclosure, when thermal runaway occurs, the curling portion of the battery cell can be effectively prevented from being damaged.

[0038] For example, the present disclosure can prevent a pinhole phenomenon from occurring in a bead portion of a battery cell when thermal runaway occurs.

[0039] However, the effects that can be achieved by the present disclosure are not limited to the above-mentioned effects, and those skilled in the art can clearly understand other technical effects not mentioned above from the description of the present disclosure set forth below. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The following drawings illustrate embodiments of the present disclosure and are used to help further understand the technical concept of the present disclosure and the detailed description of the present disclosure to be described later. Therefore, the present disclosure should not be interpreted as being limited to the matters shown in the drawings.

[0041] Figure 1 is a view showing a battery cell according to an embodiment of the present disclosure.

[0042] Figure 2 yes Figure 1 Vertical cross-sectional view of .

[0043] Figure 3 yes Figure 1 A vertical cross-sectional view of a battery cell.

[0044] Figure 4 is a perspective view illustrating a current collector according to an embodiment of the present disclosure.

[0045] Figure 5 is a perspective view illustrating a current collector according to another embodiment of the present disclosure.

[0046] Figure 6 is a perspective view illustrating a current collector according to another embodiment of the present disclosure.

[0047] Figure 7 is a perspective view illustrating a current collector according to another embodiment of the present disclosure.

[0048] Figure 8 is a perspective view illustrating a current collector according to another embodiment of the present disclosure.

[0049] Figure 9 is a perspective view illustrating a current collector according to another embodiment of the present disclosure.

[0050] Figure 10 is a diagram illustrating a situation in which thermal runaway occurs in a battery cell to which a conventional current collector is applied.

[0051] Figure 11 is a view illustrating a situation where thermal runaway occurs in a battery cell according to an embodiment of the present disclosure.

[0052] Figure 12 is a view illustrating another case where thermal runaway occurs in a battery cell according to an embodiment of the present disclosure.

[0053] Figure 13 is a view illustrating another case where thermal runaway occurs in a battery cell according to an embodiment of the present disclosure.

[0054] Figure 14 is a view showing a battery pack including a battery cell according to an embodiment of the present disclosure.

[0055] Figure 15 It is shown that Figure 14 View of the battery pack of a vehicle.

[0056] In some figures, corresponding parts are given the same reference numerals. Those skilled in the art will understand that the figures illustrate elements simply and clearly and are not necessarily drawn to scale. For example, to aid understanding of the various embodiments, the sizes of some elements shown in the figures may be exaggerated compared to other elements. In addition, to avoid obstructing understanding of the spirit of the various embodiments of the present disclosure, elements that are useful or necessary in commercially feasible embodiments but are known in the art may not generally be described. DETAILED DESCRIPTION

[0057] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. Prior to this, the terms and words used in the specification and claims should not be interpreted as limited to their ordinary or dictionary meanings, but should be interpreted as meanings and concepts consistent with the technical ideas of the present disclosure based on the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. Therefore, since the embodiments described in this specification and the configurations shown in the drawings are merely some exemplary embodiments of the present disclosure and do not represent all the technical ideas of the present disclosure, it should be understood that various equivalent examples and variations that can replace the embodiments may exist when this application is filed.

[0058] In addition, to help understand the present disclosure, the accompanying drawings are not drawn to scale, and the sizes of some components may be exaggerated. In addition, in different embodiments, the same components may be assigned the same reference numerals.

[0059] A description of two compared objects as being the same means that the objects are "substantially the same." Thus, "substantially the same" may include situations where there is a deviation that is considered low in the art (e.g., less than 5%). Furthermore, uniformity of a parameter in a region may refer to uniformity from an average perspective.

[0060] Although terms such as first and second are used to describe various elements, the components are of course not limited by these terms. These terms are only used to distinguish one component from another, and the first component can of course be the second component unless otherwise specified.

[0061] Throughout the specification, unless explicitly stated otherwise, each component may be in the singular or the plural.

[0062] When any component is described as being disposed “on top (or bottom)” of a component or “above (or below)” this component, this may mean that the arbitrary component is disposed in contact with the top surface (or bottom surface) of the component, and another component may be interposed between the component and any component disposed above (or below) the component.

[0063] In addition, when any component is described as being “connected,” “coupled,” or “engaged” to another component, it should be understood that these components can be directly connected or engaged to each other, but another component can be “interposed” between the components, or the components can be “connected,” “coupled,” or “engaged” to each other via another component.

[0064] Throughout the description, unless expressly stated otherwise, when referred to as "A and / or B," this means A, B, or A and B, and when referred to as "C to D," this means C or greater and D or less, unless expressly stated otherwise.

[0065] As used herein, the terms "about," "approximately," and "substantially" are used to indicate a range of values or degrees or their approximate values, taking into account inherent manufacturing and material tolerances, and to prevent an infringer from taking unfair advantage of the content described, where exact or absolute values are mentioned to aid in understanding the disclosure.

[0066] For ease of explanation, in this description, the direction along the longitudinal direction of the winding axis of the electrode assembly 10 wound into a jellyroll shape is referred to as the axial direction Y. Furthermore, the direction around the winding axis is referred to as the circumferential direction or peripheral direction X. Furthermore, the direction approaching or away from the winding axis is referred to as the radial direction. The direction approaching the winding axis is referred to as the centripetal direction, and the direction away from the winding axis is referred to as the centrifugal direction.

[0067] When thermal runaway occurs in a secondary battery, pinholes may appear on the side surfaces of the battery cells. In this case, the resulting thermal runaway phenomenon can directly damage nearby battery cells, causing them to explode one after another and potentially leading to chain ignition. Therefore, it is necessary to reduce the frequency of pinhole phenomena.

[0068] In addition, in view of the fact that the frequency of pinhole phenomenon occurring in the curling portion is high when thermal runaway occurs, and considering that when thermal runaway occurs, the explosion flame cannot be smoothly discharged to the exhaust portion and is guided to the side portion, thereby directly contacting the curling portion located nearby, thereby generating pinholes, the present disclosure provides a structure of an electrode assembly, with the help of which the flame can be smoothly discharged.

[0069] For example, the battery cell according to an embodiment of the present disclosure is provided with a channel or passage through which the explosion flame can be smoothly discharged to the exhaust portion when thermal runaway occurs.

[0070] Figure 1 is a view showing a battery cell 1 according to an embodiment of the present disclosure, Figure 2 yes Figure 1 Vertical sectional perspective view of . Figure 3 yes Figure 1 A vertical cross-sectional view of a battery cell 1 is shown.

[0071] refer to Figure 1 and Figure 2 The battery cell 1 according to an embodiment of the present disclosure includes an electrode assembly 10, a battery case 20, and a current collector 30. The battery cell 1 may further include a case cover 40. The present disclosure is not limited by the shape of the battery and may also be applied to batteries having other shapes, such as prismatic batteries.

[0072] refer to Figure 2 and Figure 3 , the electrode assembly 10 includes a first uncoated portion 11 and a second uncoated portion 12. For example, the electrode assembly 10 according to the embodiment has a wound structure in which the first electrode and the second electrode are wound around a winding axis with a separator sandwiched therebetween to define a core and an outer peripheral surface. For example, the electrode assembly 10 applied to the present disclosure may be a jellyroll-type electrode assembly 10. In this case, an additional separator may be provided on the outer peripheral surface of the electrode assembly 10 to insulate the electrode assembly from the battery case 20.

[0073] According to an embodiment of the present disclosure, the first electrode may include a first electrode current collector and a first electrode active material, and the first electrode active material is applied to one or both surfaces of the first electrode current collector. Figure 1 There is an uncoated portion to which the first electrode active material is not applied in one end portion in the direction parallel to the height direction of the battery cell 1 shown in FIG. For example, the first electrode includes an uncoated portion that is not coated with an active material at the end portion of the long side along the winding direction and is exposed to the outside of the separator. Hereinafter, the uncoated portion serving as the first electrode tab is referred to as the first uncoated portion 11. The first uncoated portion 11 is in the height direction (parallel to the height direction of the battery cell 1 shown in FIG. Figure 1 The first electrode 10 is disposed in the upper portion of the electrode assembly 10 housed in the battery case 20 in a direction parallel to the height direction of the battery cell 1 shown in FIG. For example, the first electrode includes a first uncoated portion 11 that is not coated with an active material layer in the long side end portion and is exposed to the outside of the separator, and at least a portion of the first uncoated portion 11 itself serves as an electrode tab. The first uncoated portion 11 can be, for example, a negative electrode tab.

[0074] Meanwhile, at least a portion of the first non-coating portion 11 may include a plurality of segmented pieces divided along the winding direction of the electrode assembly 10. In this case, the plurality of segmented pieces may be bent along the radial direction of the electrode assembly 10.

[0075] refer to Figure 2 and Figure 3, according to an embodiment of the present disclosure, a plurality of bent segmented pieces of the first uncoated portion 11 may overlap in several layers to form a bent surface. In this case, the joint connection portion 32 (to be described later) of the current collector 30 may be connected to the bent surface. The joint connection portion 32 may be connected to an area where a plurality of segmented pieces overlap in several layers. In this case, welding may be performed on a predetermined area in a state where the joint connection portion 32 is placed on the bent surface of the first uncoated portion 11. For example, the joint connection portion 32 may be connected to an area where a plurality of segmented pieces of the first uncoated portion 11 overlap in several layers. For example, from Figure 5 It can be seen that the joint coupling portion 32 may have at least one welded portion welded to a predetermined area when seated on the bent surface of the first non-coating portion 11 .

[0076] According to an embodiment of the present disclosure, the second electrode may include a second electrode current collector and a second electrode active material, and the second electrode active material is applied to one or both surfaces of the second electrode current collector. Figure 1 There is an uncoated portion to which the second electrode active material is not applied in the other end portion (in a direction parallel to the height direction of the battery cell 1 shown in ). For example, the second electrode includes an uncoated portion, which is not coated with an active material on the long side end portion along the winding direction and is exposed to the outside of the diaphragm. Hereinafter, the uncoated portion used as the second electrode connector is referred to as a second uncoated portion 12. For example, the second uncoated portion 12 is arranged in the lower portion along the height direction of the electrode assembly 10 housed in the battery case 20. For example, the second electrode includes a second uncoated portion 12, which is not coated with an active material layer in the long side end portion and is exposed to the outside of the diaphragm, and at least a portion of the second uncoated portion 12 itself is used as an electrode connector. The second uncoated portion 12 can be, for example, a positive electrode connector.

[0077] Meanwhile, in the present disclosure, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may be used without limitation as long as they are active materials known in the art.

[0078] refer to Figure 1 According to an embodiment of the present disclosure, the battery case 20 is a substantially cylindrical receiver with an opening formed on one side thereof, and is made of a conductive metal material. The side surface of the battery case 20 and the bottom surface located on the side opposite to the opening are generally formed integrally as a single piece. For example, the battery case 20 generally has an open top and a closed bottom in the height direction. The bottom surface of the battery case 20 may have a substantially flat shape. The battery case 20 accommodates the electrode assembly 10 through an opening formed on one side in the height direction. The battery case 20 can also accommodate an electrolyte through the opening.

[0079] For example, the battery case 20 includes a curling portion 21 formed at an end adjacent to an opening provided at the top of the battery case 20. The battery case 20 also includes a crimping portion 22 formed on the curling portion 21. The curling portion 21 has a shape in which the outer peripheral surface of the battery case 20 is pressed to a predetermined depth. Alternatively, the curling portion 21 may be pressed inwardly in an area between an opening formed at one side of the battery case 20 and a receiving portion configured to receive the electrode assembly 10.

[0080] According to an embodiment of the present disclosure, the beading portion 21 is formed in the upper portion of the electrode assembly 10. The inner diameter of the battery case 20 in the region where the beading portion 21 is formed is smaller than the diameter of the electrode assembly 10. One or more joint coupling portions 32 (to be described later) of the current collector 30 may be located below the beading portion 21. Alternatively, the joint coupling portion 32 may be located below the bottom surface of the beading portion 21.

[0081] According to an embodiment of the present disclosure, the curling portion 21 provides a support surface on which the case cover 40 can be placed. In addition, the curling portion 21 can provide a support surface on which at least a portion of the outer peripheral edge of the current collector 30 (to be described later) can be placed and coupled. For example, at least a portion of the outer peripheral edge of the current collector 30 of the present disclosure and / or the outer peripheral edge of the case cover 40 can be placed on the top surface of the curling portion 21. In order to stably support at least a portion of the outer peripheral edge of the current collector 30 and / or the outer peripheral edge of the case cover 40, the top surface of the curling portion 21 can have a shape extending in a direction substantially parallel to the bottom surface of the battery case (e.g., in a direction approximately perpendicular to the side wall of the battery case 20).

[0082] According to an embodiment of the present disclosure, the beaded portion 21 may serve as a support portion 31 configured to: prevent the electrode assembly 10 (which may have a size approximately corresponding to the inner diameter of the battery case 20) from being removed through the opening formed at the top of the battery case 20; and allow the case cover 40 to be seated thereon. The upper beaded portion 21 may serve as a support portion 31 configured to secure, for example, the contact portion of the current collector 30 and the sealing gasket G1 in addition to the case cover 40.

[0083] According to an embodiment of the present disclosure, the crimping portion 22 is formed above the beading portion 21. The crimping portion 22 has an extended and bent shape to surround the outer peripheral edge of the housing cover 40 provided on the beading portion 21. Due to the shape of the crimping portion 22, the housing cover 40 is fixed to the beading portion 21.

[0084] Return Reference Figure 1 and Figure 2The current collector 30 according to an embodiment of the present disclosure is housed inside the battery case 20, is electrically connected to the electrode assembly 10, and is also electrically connected to the battery case 20. For example, the current collector 30 electrically interconnects the electrode assembly 10 and the battery case 20.

[0085] Figure 4 is a perspective view showing a current collector 30 according to an embodiment of the present disclosure, and Figure 5 is a perspective view illustrating a current collector 30 according to another embodiment of the present disclosure. Figures 6 to 9 is a perspective view illustrating a current collector 30 according to another embodiment of the present disclosure.

[0086] refer to Figures 4 to 7 According to an embodiment of the present disclosure, the current collector 30 includes: a support portion 31 located on one surface of the electrode assembly 10; a joint connection portion 32 extending from the support portion 31 and connected to the first uncoated portion 11; and a shell connection portion 33 extending from the support portion 31 and connected to the inner surface of the battery shell 20.

[0087] refer to Figures 4 to 9 According to an embodiment of the present disclosure, a fracture portion 34 is provided at the boundary between the support portion 31 and each joint coupling portion 32, and the fracture portion is configured to be lower in strength than the surrounding area. For example, the fracture portion 34 can be configured to be structurally weaker than the surrounding area. For example, the fracture portion 34 can be configured to be thinner than the thickness of the surrounding area. Alternatively, the fracture portion 34 can be configured to be lower in density than the surrounding area. According to an embodiment of the present disclosure, the fracture portion 34 can include, for example, a notch line NL including a plurality of notches or a through hole HC.

[0088] With the structure described above in which the rupture portion 34 according to the embodiment of the present disclosure is provided at the boundary between the support portion 31 and each joint coupling portion 32, when a thermal runaway phenomenon occurs inside the battery cell 1 and a flame is generated and discharged, strong pressure can be applied to the rupture portion 34, thereby causing rupture in the rupture portion 34. Therefore, the support portion 31 of the current collector 30 can be separated from the joint coupling portion 32. For example, when a flame is discharged from the interior of the battery cell 1, the rupture portion 34 can rupture to allow the joint coupling portion 32 of the current collector 30 to separate. As a result, due to the rupture of the rupture portion 34, the flame generated inside the battery cell 1 can be smoothly discharged to the outside.

[0089] refer to Figures 5 to 9 , the current collector 30 according to an embodiment of the present disclosure may include through holes HC passing through the current collector 30. The through holes HC may be as follows Figure 5The through hole HC is shown as a circle, but the shape is not limited to this. For example, the through hole HC can be configured into a polygonal shape other than a circle, such as a triangle or a square. The flame generated inside the battery cell 1 can be smoothly discharged through the through hole HC.

[0090] For example, when thermal runaway begins on the electrode assembly 10 side, the current collector 30 is located above the electrode assembly 10. With the structure of a conventional battery cell 1, the flames generated from the electrode assembly 10 are blocked by the current collector 30 and cannot be smoothly discharged. Consequently, there is a problem: the flames move toward the bead portion 21 located in the area near the electrode assembly 10 and the current collector 30, thereby forming pinholes in the bead portion 21. When pinholes form in the bead portion 21, the possibility of direct damage to other battery cells 1 located around the battery cell 1 where the fire occurred increases. Ultimately, the spread of the fire to other battery cells 1 is unavoidable.

[0091] According to embodiments of the present disclosure, since current collector 30 is provided with through-holes HC, flames generated in electrode assembly 10 can be discharged through through-holes HC. Consequently, the flames can be prevented from advancing toward beaded portion 21. According to the present disclosure, damage to beaded portion 21 by the flames can ultimately be prevented. Alternatively, according to the present disclosure, the formation of pinholes in beaded portion 21 can be effectively prevented.

[0092] According to an embodiment of the present disclosure, the through hole HC may be located on the notch line NL of the fracture portion 34. Since the structure includes both the fracture portion 34 and the through hole HC, the strength of the boundary region between the support portion 31 and the joint coupling portion 32 may be configured to be lower than the strength of the surrounding region, compared to a structure including only one of the fracture portion and the through hole.

[0093] For example, reference Figure 5 Since the through holes HC are provided on the current collector 30 , exhaust gas and / or flame generated due to thermal runaway on the electrode assembly 10 side may be smoothly discharged to the outside through the through holes HC.

[0094] refer to Figure 5 According to an embodiment of the present disclosure, when the through-holes HC are formed in the boundary region between the support portion 31 and the joint connection portion 32, the width of the connection portion in the boundary region between the support portion 31 and the joint connection portion 32 is reduced due to the removal of material from the current collector 30 in the region where the through-holes HC are formed. Therefore, the strength of the boundary region between the support portion 31 and the joint connection portion 32 can be configured to be lower than that of the surrounding region. Therefore, when exhaust gas generated due to thermal runaway, etc., is ejected upward from the electrode assembly 10, only the joint connection portion 32 will separate and fall off. Ultimately, the flame generated in the electrode assembly 10 can be smoothly discharged through the empty space formed when the joint connection portion 32 separates.

[0095] refer to Figure 5 According to an embodiment of the present disclosure, when a notch line NL including a plurality of notches is formed in the boundary region between the support portion 31 and the joint coupling portion 32, the thickness and / or density of the current collector 30 is reduced in the region where the notches are formed. Therefore, the strength of the boundary region between the support portion 31 and the joint coupling portion 32 can be configured to be lower than that of the surrounding region. Therefore, when exhaust gas generated due to thermal runaway, etc., is ejected upward from the electrode assembly 10, only the joint coupling portion 32 will separate and fall off. Ultimately, flames generated in the electrode assembly 10 can be smoothly discharged through the empty space formed when the joint coupling portion 32 separates.

[0096] refer to Figure 5 According to an embodiment of the present disclosure, the through hole HC may be configured to be located at the center of the boundary between the support portion 31 and the joint coupling portion 32. For example, the connection portions on opposite sides of the through hole HC provided in the boundary region between the support portion 31 and the joint coupling portion 32 may be configured to have the same width.

[0097] With this structure, since the connection portions on opposite sides of the through hole HC provided in the boundary region between the support portion 31 and the joint coupling portion 32 are configured to have the same width, the joint coupling portion 32 is pressed upward by the exhaust gas, and thus the same force can be applied to each connection portion. As a result, since all the connection portions are broken, it is possible to prevent the joint coupling portion 32 from being incompletely separated due to the breaking of only one connection portion.

[0098] At least one through hole HC according to another embodiment of the present disclosure may be provided on the support portion 31 .

[0099] For example, reference Figure 6 , a plurality of through holes HC may be provided on the support portion 31 of the current collector 30. Meanwhile, the through holes HC may have a circular shape, for example, but is not necessarily limited thereto. For example, a plurality of through holes HC may be provided along the periphery of the current collector hole H2. For example, Figure 6 An embodiment is shown in which four through holes HC are provided along the outer circumference of the current collector hole H2.

[0100] In this way, when the through holes HC are provided on the support portion 31, the exhaust gas and / or flame generated from the electrode assembly 10 can be smoothly discharged to the outside. For example, since the current collector 30 covers the upper portion of the electrode assembly 10, in order to discharge the gas and / or flame from the electrode assembly 10, there should be holes on the current collector 30, or the current collector 30 should be separated. In this regard, according to an embodiment of the present disclosure, since a plurality of through holes HC are provided on the current collector 30, the gas and / or flame generated from the electrode assembly 10 can be smoothly discharged. For example, the core side region of the electrode assembly 10 is covered by the support portion 31 of the current collector 30, and when a plurality of through holes HC are provided on the support portion 31, the exhaust gas and / or flame generated in the core side region can be smoothly discharged upward.

[0101] According to another embodiment of the present disclosure, the joint coupling portion 32 may be provided with at least one through hole HC.

[0102] For example, reference Figure 7 , a through hole HC may be provided on each joint coupling portion 32 of the current collector 30. For example, Figure 7 An embodiment is shown in which a through hole HC is provided in each region corresponding to the joint coupling portion 32 .

[0103] In this manner, when the through-holes HC are provided on the joint coupling portion 32, exhaust gas and / or flames generated from the electrode assembly 10 can be smoothly discharged to the outside through the through-holes HC. In particular, the outer peripheral area of the electrode assembly 10 is covered by the joint coupling portion 32 of the current collector 30, and when a plurality of through-holes HC are provided on the joint coupling portion 32, exhaust gas and / or flames generated in the outer peripheral area can be smoothly discharged upward.

[0104] However, when too many through-holes HC are provided on the joint coupling portion 32, the weldable area between the joint coupling portion 32 and the electrode assembly 10 may be excessively reduced. In this case, considering that the welded area between the joint coupling portion 32 and the electrode assembly 10 may be reduced and the coupling strength may be weakened, an appropriate balance is required between the area of the joint coupling portion 32 and the number of through-holes HC to be formed.

[0105] refer to Figure 8 According to an embodiment of the present disclosure, the through hole HC may be further provided on the joint coupling portion 32 of the current collector 30 and at the same time provided on the support portion 31. Figure 9According to an embodiment of the present disclosure, through holes HC may be further provided on the support portion 31 while being formed in the boundary region between the support portion 31 and the joint coupling portion 32. In addition, although not shown in the drawings, as another embodiment of the present disclosure, through holes HC may be further provided on the support portion 31 while being formed in the boundary region between the support portion 31 and the joint coupling portion 32. In addition, the position where the through holes HC are provided is not limited to the above-mentioned embodiment, and may be provided at any position or combination of positions on the current collector 30 as appropriate, and these embodiments should be considered to fall within the scope of the present disclosure.

[0106] According to an embodiment of the present disclosure, the notch line may be configured to have a curved shape. Figures 4 to 9 , the notch line NL may be configured in the form of a curve that is convex toward the center of the current collector 30. Alternatively, although not shown in the drawings, the notch line NL may be configured in the form of a curve that is concave toward the center of the current collector 30. Alternatively, the notch line NL may be configured in a substantially linear shape. For example, the shape of the notch line NL is not limited to one shape and may have various shapes, and such various embodiments are included within the scope of the present disclosure.

[0107] According to an embodiment of the present disclosure, each joint coupling portion 32 may be formed such that a position spaced apart from the connection portion by a predetermined distance toward a longitudinal end of the joint coupling portion 32 has a greater width than the width of the connection portion between the joint coupling portion 32 and the support portion 31. Figures 4 to 9 , each joint connection portion 32 can be configured to have a generally fan-shaped shape, wherein a position spaced a predetermined distance from the connection portion toward the longitudinal end of the joint connection portion 32 has a larger width than the width of the connection portion between the joint connection portion 32 and the support portion 31 .

[0108] With this structure, the joint connection portion 32 can be configured to have a smaller width at the connection between the joint connection portion 32 and the support portion 31. Consequently, the joint connection portion 32 can be configured to have lower strength at the connection between the joint connection portion 32 and the support portion 31. Therefore, when thermal runaway occurs within the battery cell 1 and flames are exhausted, strong pressure can be applied to the connection between the joint connection portion 32 and the support portion 31, causing the connection between the joint connection portion 32 and the support portion 31 to break. Consequently, the support portion 31 of the current collector 30 can be separated from the joint connection portion 32. For example, when flames are exhausted from the interior of the battery cell 1, the connection between each joint connection portion 32 and the support portion 31 can break, allowing the joint connection portion 32 of the current collector 30 to separate. As a result, due to the rupture of the connection between each joint connection portion 32 and the support portion 31, the flame generated within the battery cell 1 can be smoothly exhausted to the outside.

[0109] In addition, with this structure, since the width at the position spaced a predetermined distance from the connecting portion toward the longitudinal end of each joint coupling portion 32 is formed larger, the total cross-sectional area of the joint coupling portion 32 can be ensured to be large. For example, since the joint coupling portion 32 has a generally fan-shaped shape, a large contact area can be ensured between the joint coupling portion 32 and the electrode assembly 10. Therefore, the joint coupling portion 32 and the electrode assembly 10 can be smoothly welded together. In addition, the contact area between each joint coupling portion 32 and the electrode assembly 10 becomes larger, so that the internal resistance of the battery can be effectively reduced.

[0110] According to an embodiment of the present disclosure, the longitudinal end portion of the joint coupling portion 32 may have a substantially arc shape to correspond to the inner circumferential surface of the battery case 20. For example, referring to Figures 4 to 9 , the longitudinal end portion of each joint coupling portion 32 may be configured to have an arc shape, so that the joint coupling portion 32 may be configured to have a substantially fan-shaped shape.

[0111] With this structure, since the longitudinal ends of each joint connection portion 32 can be arranged further away from the center of the current collector 30, the total cross-sectional area of the joint connection portion 32 can be ensured to be large. For example, since the joint connection portion 32 has a generally fan-shaped shape, a large contact area between the joint connection portion 32 and the electrode assembly 10 can be ensured. Therefore, the joint connection portion 32 and the electrode assembly 10 can be smoothly welded. In addition, the contact area between each joint connection portion 32 and the electrode assembly 10 becomes larger, so that the internal resistance of the battery can be effectively reduced.

[0112] According to an embodiment of the present disclosure, the joint coupling portion 32 may be configured to have a greater width than the housing coupling portion 33. For example, referring to Figures 4 to 9 , the joint coupling portion 32 is formed in a wide fan shape, and the housing coupling portion 33 may be configured to have a substantially rectangular band shape.

[0113] This structure ensures that the total cross-sectional area of each joint coupling portion 32 is large. For example, each joint coupling portion 32 is shaped and configured to have a greater width than the housing coupling portion 33, thereby ensuring a large contact area between the joint coupling portion 32 and the electrode assembly 10. As a result, the joint coupling portion 32 and the electrode assembly 10 can be welded smoothly. In addition, the contact area between each joint coupling portion 32 and the electrode assembly 10 becomes larger, effectively reducing the internal resistance of the battery.

[0114] Meanwhile, in the foregoing, as an embodiment for ensuring a large area of the joint coupling portion 32, the joint coupling portion 32 has a substantially fan-shaped shape, but the scope of the present disclosure is not limited thereto. Any shape that can ensure that the contact area between the joint coupling portion 32 and the electrode assembly 10 is higher than a certain level is within the scope of the present disclosure.

[0115] According to an embodiment of the present disclosure, a support portion 31 and a joint connection portion 32 are provided on the electrode assembly 10. The joint connection portion 32 may be connected to the first uncoated portion 11 of the electrode assembly 10. The joint connection portion 32 may be connected to the first uncoated portion 11 along, for example, the radial direction of the electrode assembly 10 by welding. For example, the joint connection portion 32 may be welded to the first uncoated portion 11 in a state substantially parallel to the bottom surface of the battery case 20. A weld bead may be formed between the first uncoated portion 11 and the joint connection portion 32. For example, the weld bead may form a substantially linear welding pattern extending along the radial direction of the electrode assembly 10. For example, the welding pattern may have a linear shape connecting spot welds. The welding pattern may include one pattern or two or more patterns extending along the radial direction of the electrode assembly 10.

[0116] For example, the weld pattern may be configured to be approximately perpendicular to the notch line NL. Alternatively, as described above, the weld pattern may have a substantially linear shape along the radial direction from the center of the current collector 30. In this case, the notch line NL may be configured to be curved, with its curvature convex toward the center of the current collector 30. A tangent to the notch line NL at the point where the distance from the weld pattern to the notch line NL is shortest may be configured to be approximately perpendicular to the weld pattern. For example, the weld pattern and the notch line NL may be configured to be approximately perpendicular to each other.

[0117] With this structure, easy welding can be ensured during the process. In addition, with this structure, since the welding pattern is formed along the radial direction of the electrode assembly 10, the current can flow uniformly from the electrode assembly 10. In addition, with the above structure, the current path is shortened, so that the resistance in the battery can be effectively reduced.

[0118] refer to Figures 4 to 9 According to an embodiment of the present disclosure, the joint coupling portion 32 and the case coupling portion 33 are indirectly connected via the support portion 31 and are not directly connected to each other. Therefore, when an external impact is applied to the battery cell 1 of the present disclosure, the possibility of damage to the coupling portion between the current collector 30 and the electrode assembly 10 and the coupling portion between the current collector 30 and the battery case 20 can be minimized.

[0119] refer to Figures 4 to 9According to an embodiment of the present disclosure, one or more joint couplings 32 and / or one or more shell couplings 33 may be provided. The one or more joint couplings 32 and the one or more shell couplings 33 may be arranged, for example, in a substantially radial shape, a cross shape, or a combination thereof relative to the center of the current collector 30. On the other hand, each of the plurality of shell couplings 33 may be disposed between adjacent joint couplings among the joint couplings 32.

[0120] Reference again Figure 3 and Figure 4 According to an embodiment of the present disclosure, a support portion 31 and a plurality of joint coupling portions 32 are provided on the electrode assembly 10. For example, the joint coupling portion 32 is coupled to the first uncoated portion 11 of the electrode assembly 10. The joint coupling portion 32 may be coupled to the first uncoated portion 11 by welding, for example, along the radial direction of the electrode assembly 10. For example, the joint coupling portion 32 may be welded to the first uncoated portion 11 in a state substantially parallel to the bottom surface of the battery case 20. The weld formed between the first uncoated portion 11 and the joint coupling portion 32 may form, for example, a substantially linear weld pattern extending along the radial direction of the electrode assembly 10.

[0121] According to an embodiment of the present disclosure, not only the joint coupling portion 32 but also the support portion 31 can be coupled to the first uncoated portion 11. The joint coupling portion 32 and the first uncoated portion 11 can be coupled by welding. When the beading portion 21 is formed in the battery case 20, the support portion 31 and the joint coupling portion 32 are located below the beading portion 21.

[0122] For example, the support portion 31 may include a current collector hole H2 formed at a position corresponding to the winding hole H1 formed approximately at the center of the electrode assembly 10. The winding hole H1 and the current collector hole H2, which are connected to each other, can be used as a channel for inserting a welding rod or emitting a laser beam for welding between the terminal and the second current collector 30 or between the terminal and the lead joint (not shown). The diameter of the current collector hole H2 may be approximately equal to or larger than the diameter of the winding hole H1 of the electrode assembly 10 to prevent the winding hole H1 in the core of the electrode assembly 10 from being covered. Considering that when the diameter of the current collector hole H2 is much smaller than the diameter of the winding hole H1, the winding hole H1 will be covered and the liquid injectability will be reduced, and it may be difficult to ensure sufficient space for laser emission, the diameter of the current collector hole H2 and the diameter of the winding hole H1 can be appropriately adjusted.

[0123] According to an embodiment of the present disclosure, the plurality of joint couplings 32 may have a shape extending substantially radially from the support portion 31 of the current collector 30 toward the sidewall of the battery case 20. The plurality of joint couplings 32 may be positioned spaced apart from each other along the circumference of the support portion 31.

[0124] According to an embodiment of the present disclosure, the plurality of case coupling portions 33 may have a shape extending generally radially from the support portion 31 of the current collector 30 toward the sidewall of the battery case 20. The plurality of case coupling portions 33 may be positioned to be spaced apart from each other along the circumference of the support portion 31. At least one case coupling portion 33 may be located between adjacent joint coupling portions 32.

[0125] For example, the housing coupling portion 33 may extend from the support portion 31 and be electrically coupled to the inner surface of the battery housing 20. For example, the housing coupling portion 33 may be coupled to the inner surface of the battery housing 20, such as the beaded portion 21. In particular, the housing coupling portion 33 may be coupled to the top surface of the beaded portion 21.

[0126] Alternatively, the case coupling portion 33 may include a contact portion coupled to the inner surface of the battery case 20 and a connecting portion interconnecting the support portion 31 and the contact portion.

[0127] According to an embodiment of the present disclosure, the contact portion is coupled to the inner surface of the battery case 20. When the beaded portion 21 is formed in the battery case 20, the contact portion may be coupled to the beaded portion 21. In this case, for stable contact and coupling, both the beaded portion 21 and the contact portion may have a shape extending in a direction substantially parallel to the bottom surface of the battery case 20 (i.e., substantially perpendicular to the side wall of the battery case 20).

[0128] According to an embodiment of the present disclosure, the contact portion may be welded to the top surface of the bead portion 21. For example, the weld portion may be formed in the top surface region of the bead portion 21. The weld portion formed between the contact portion and the bead portion 21 may be formed to be narrower than the top surface of the bead portion 21. The welding method for coupling the battery case 20 and the current collector 30 may include, for example, laser welding, ultrasonic welding, or spot welding.

[0129] Figure 10 is a diagram illustrating a case where thermal runaway occurs in a battery cell 1 to which a conventional current collector 30 is applied.

[0130] Figure 10 The battery cell 1 of the prior art shown includes a current collector 30, and the current collector 30 does not include any holes other than the current collector hole H2 located in the center. With the structure of the current collector 30 of the prior art, the flame generated in the electrode assembly 10 is blocked by the current collector 30 and may not be able to be discharged smoothly. As a result, there may be a problem in which the flame moves toward the bead portion 21 located in the area near the electrode assembly 10 and the current collector 30, thereby forming pinholes in the bead portion 21. When pinholes are formed in the bead portion 21, there is a high possibility that other battery cells 1 located around the battery cell 1 where the fire occurred will be directly damaged, and ultimately, the spread of the fire to other battery cells 1 may be unavoidable.

[0131] Figure 11 is a diagram illustrating a situation where thermal runaway occurs in the battery cell 1 according to an embodiment of the present disclosure.

[0132] Figure 11 The battery cell 1 according to an embodiment of the present disclosure shown includes a current collector 30 having a fracture portion 34. The current collector 30 may have a through hole HC. With this structure, the flame generated in the electrode assembly 10 can be discharged to the outside of the electrode assembly 10 through the through hole HC. Therefore, it is possible to prevent the flame from advancing toward the bead portion 21. According to the present disclosure, the bead portion 21 can ultimately be prevented from being damaged by the flame. Alternatively, according to an embodiment of the present disclosure, the generation of pinholes in the bead portion 21 can be effectively prevented.

[0133] Figure 12 is a view showing another case where thermal runaway occurs in the battery cell 1 according to an embodiment of the present disclosure, and Figure 13 is a view showing another case where thermal runaway occurs in the battery cell 1 according to an embodiment of the present disclosure.

[0134] because Figure 12 and Figure 13 The illustrated current collector 30 is similar to the current collector 30 of the previous embodiment, and thus redundant descriptions of substantially the same or similar components as the previous embodiment will be omitted, and hereinafter, the current collector 30 will be described focusing on differences from the previous embodiment.

[0135] refer to Figure 12 According to an embodiment of the present disclosure, a notch line NL including a plurality of notches may be formed in the boundary region between the support portion 31 and each joint coupling portion 32. With this structure, when exhaust gas, for example due to thermal runaway, is ejected upward from the electrode assembly 10, the joint coupling portion 32 receives upward pressure from the exhaust gas, allowing the joint coupling portion 32 to bend upward relative to the notch line NL. When the joint coupling portion 32 bends upward, flames generated in the electrode assembly 10 can be smoothly discharged through the empty space formed between the electrode assembly 10 and the joint coupling portion 32.

[0136] Figure 13 is shown with Figure 12 Compared with the case of , the exhaust gas according to the embodiment of the present disclosure is ejected more powerfully. Figure 13 In the embodiment, the joint coupling portion 32 receives upward pressure from the exhaust gas, and as a result, the joint coupling portion 32 can be separated from the current collector 30 along the notch line NL and fall off. The flame generated in the electrode assembly 10 can eventually be smoothly discharged through the empty space formed when the joint coupling portion 32 is separated.

[0137] In this manner, in the embodiment of the present disclosure, by providing a structure with through holes HC and / or notch lines NL at the boundary between the support portion 31 and each joint coupling portion 32, flames generated in the electrode assembly 10 can be smoothly discharged to the outside. Therefore, it is possible to prevent the flames from spreading to the beading portion 21 located near the side portions of the electrode assembly 10 and the current collector 30. As a result, by using the structure of the present disclosure, damage such as pinhole phenomena can be prevented from occurring in the beading portion 21.

[0138] Return Reference Figures 1 to 3 According to an embodiment of the present disclosure, the housing cover 40 has a vent portion 41 formed to prevent an increase in internal pressure due to gas generated inside the battery housing 20. The vent portion 41 may be configured to rupture when the internal pressure of the battery housing 20 increases to a predetermined level or higher. For example, the vent portion 41 may be formed in a portion of the housing cover 40 and be an area that is structurally weaker than the surrounding area so as to be easily ruptured when internal pressure is applied. For example, the vent portion 41 may be an area having a thinner thickness than the surrounding area. Reference Figure 1 and Figure 2 , the exhaust portion 41 can form a substantially circular closed loop.

[0139] Referring back to the embodiment of the present disclosure Figures 1 to 3 , the case cover 40 covers the opening formed at one side of the battery case 20. The case cover 40 can be fixed by a crimping portion 22 formed at the top of the battery case 20. In this case, the sealing gasket G1 can be inserted between the battery case 20 and the case cover 40 and between the current collector 30 and the case cover 40 to improve the fixing force and sealing characteristics of the battery case 20. In this case, the contact portion can be inserted between the crimping portion 21 of the battery case 20 and the sealing gasket G1. In this way, the contact portion inserted between the crimping portion 21 and the sealing gasket G1 can be fixed by bending the crimping portion 22 extending upward from the crimping portion 21.

[0140] According to an embodiment of the present disclosure, a battery module includes a plurality of battery cells, the basic unit cell of which is a cell used in various embodiments of the present disclosure, so that when thermal runaway occurs, flames generated within the battery cells can be smoothly discharged. The battery module also includes a battery assembly in which the plurality of battery cells are electrically connected, and a module housing that houses the battery assembly. Alternatively, the battery module is used to supply power to an energy storage system.

[0141] Figure 14 is a view showing a battery pack 3 including the battery cell 1 according to an embodiment of the present disclosure.

[0142] refer to Figure 14A battery pack 3 according to an embodiment of the present disclosure includes: a battery assembly in which a plurality of battery cells 1 according to an embodiment of the present disclosure are electrically connected as described above; and a battery pack case 2 configured to house the battery assembly. In the drawings of the present disclosure, components such as bus bars for electrical connection, cooling units, and power terminals are omitted for ease of illustration.

[0143] Figure 15 It is shown that Figure 14 5. View of the battery pack 3 of the vehicle 5.

[0144] refer to Figure 15 The vehicle 5 according to the embodiment of the present disclosure may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes the battery pack 3 according to the embodiment of the present disclosure. The vehicle 5 includes a four-wheeled vehicle and a two-wheeled vehicle. The vehicle 5 operates by receiving power from the battery pack 3 according to the embodiment of the present disclosure.

[0145] Although the present disclosure has been described above with reference to several embodiments thereof, the present disclosure is not limited to the embodiments, and various changes and modifications may be made by one of ordinary skill in the art without departing from the technical idea and equivalent scope of the present disclosure defined by the appended claims.

Claims

1. A battery cell, comprising: an electrode assembly in which a first electrode and a second electrode and a separator interposed between the first electrode and the second electrode are wound about a winding axis to define a core and an outer peripheral surface, wherein the first electrode includes a first uncoated portion not coated with an active material layer along a winding direction; a battery case having an opening at one side thereof and configured to accommodate the electrode assembly through the opening; and a current collector comprising a support portion provided on the electrode assembly, a joint coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion and electrically coupled to an inner surface of the battery case, A breaking portion is provided at a boundary between the supporting portion and the joint connecting portion, and the breaking portion is configured to have lower strength than a surrounding area.

2. The battery cell according to claim 1, wherein: The fracture portion includes a notch line including a plurality of notches.

3. The battery cell according to claim 2, wherein: The current collector includes a through hole passing through the current collector.

4. The battery cell according to claim 3, wherein: The through hole is located on the notch line.

5. The battery cell according to claim 3, wherein: The through hole is located at the center of the boundary between the support portion and the joint coupling portion.

6. The battery cell according to claim 3, wherein: At least one through hole is provided on the supporting portion.

7. The battery cell according to claim 3, wherein: At least one through hole is provided on the joint connecting portion.

8. The battery cell according to claim 2, wherein: The notch line has a curved shape.

9. The battery cell according to claim 1, wherein: The joint coupling portion has a greater width than the housing coupling portion.

10. The battery cell according to claim 2, wherein: The first non-coating portion and the joint coupling portion are coupled by welding in a radial direction of the electrode assembly.

11. The battery cell according to claim 10, wherein: A weld bead is formed between the first uncoated portion and the joint coupling portion, and The weld beads form a linear welding pattern extending along a radial direction of the electrode assembly.

12. The battery cell according to claim 11, wherein: The welding pattern is arranged perpendicular to the notch line.

13. A current collector, comprising: a supporting portion, the supporting portion being disposed on the electrode assembly; a joint coupling portion extending from the support portion and electrically coupled to the electrode assembly; as well as a case coupling portion extending from the support portion and electrically coupled to an inner surface of a battery case accommodating the electrode assembly, A breaking portion is provided at a boundary between the supporting portion and the joint connecting portion, and the breaking portion is configured to have lower strength than a surrounding area.

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

15. A vehicle comprising at least one battery pack according to claim 14. 16 . A battery module comprising at least one battery cell according to claim 1 . 17 . An energy storage system comprising at least one battery module according to claim 16 .

18. A battery cell, comprising: an electrode assembly in which a first electrode and a second electrode and a separator interposed between the first electrode and the second electrode are wound about a winding axis to define a core and an outer peripheral surface, wherein the first electrode includes a first uncoated portion not coated with an active material layer along a winding direction; a battery case having an opening at one side thereof and configured to accommodate the electrode assembly through the opening; and a current collector comprising a support portion provided on the electrode assembly, a joint coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion and electrically coupled to an inner surface of the battery case, The current collector is provided with a channel or passage configured to discharge flames toward the outside when thermal runaway occurs in the electrode assembly.

19. The battery cell according to claim 18, wherein: The channel or passage includes a break portion at a boundary between the support portion and the joint coupling portion, the break portion being configured to be lower in strength than a surrounding area.

20. The battery cell according to claim 19, wherein: The fracture portion includes a notch line including a plurality of notches.

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