Battery cell, battery pack and vehicle including the battery cell.

Description

1 / 32 BATTERY CELL, BATTERY SET AND VEHICLE INCLUDING THE BATTERY CELL FIELD OF TECHNIQUE

[0001] The present invention relates to a battery cell, a battery pack and a vehicle that includes the battery cell.

[0002] This application is based on and claims priority from Korean Patent Application Number 10-2023-0135959, filed on October 12, 2023 with the Korean Intellectual Property Office, the description of which is incorporated herein by reference in its entirety. BACKGROUND OF THE TECHNIQUE

[0003] Secondary batteries, which are easy to apply depending on the product group and have electrical characteristics such as high energy density and the like, are commonly used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) that are powered by an electric drive source, as well as in portable devices. These secondary batteries are attracting attention as a new energy source to improve sustainability and energy efficiency due to the primary advantage of dramatically reducing the use of fossil fuels and another advantage of not generating byproducts resulting from energy use.

[0004] A battery pack can be configured by connecting multiple battery cells in series / parallel, depending on the charge / discharge capacity of the battery pack required for the electric vehicle (EV) or hybrid electric vehicle (HEV). In this case, it is common to prefer forming a battery module that includes at least one battery cell and then adding other components using at least one battery module, thereby forming a battery pack or battery rack. Alternatively, a battery pack has recently been manufactured in a cell-to-pack type, in which multiple battery cells are directly stored in Petition 870250088736, dated 09 / 30 / 2025, page 12 / 72 2 / 32 a combined housing unit, instead of being modularized.

[0005] However, if a fire or explosion occurs in such a battery pack that includes a large number of secondary lithium cells, the damage will certainly be even greater. A fire that occurs in a battery starts from an abnormal temperature increase and the generation of internal gas by the battery cells arranged in it due to overcharging or similar factors. Consequently, if the internal pressure of the battery cell rises above a certain level, venting occurs, so that high-temperature gases and high-temperature sparks, which include active electrode materials and aluminum particles, are ejected to the outside of the battery cell.

[0006] Meanwhile, an existing cylindrical battery cell is provided with an inwardly formed crimp portion to be recessed at one end adjacent to the opening of a battery housing to prevent vertical movement of the electrode assembly within the battery housing.

[0007] In this case, when a thermal event, such as thermal runaway, occurs within the cylindrical battery cell, high temperature and pressure are applied to the side of the battery housing, including the crimp portion. This causes a side rupture phenomenon, in which the flame does not move towards the opening, but is ejected upon destroying the side of the battery housing, such as the crimp portion. If the side rupture phenomenon occurs, the surrounding flame moves directly to other cylindrical battery cells, which can cause a thermal runaway chain reaction.

[0008] Therefore, there is a need to develop a battery cell capable of minimizing the high temperature and pressure applied to the side of the battery housing, such as the crimp portion, when a thermal event occurs, thereby suppressing the lateral rupture phenomenon. Petition 870250088736, dated 09 / 30 / 2025, page 13 / 72 3 / 32

[0009] Specifically, it is necessary to develop a battery cell that guides the flame to move towards the opening of the battery housing when a thermal event occurs, thereby suppressing the lateral rupture phenomenon. DETAILED DESCRIPTION OF THE INVENTION TECHNICAL PROBLEM

[0010] The present invention is designed to solve the problems of the related art and, therefore, the present invention is directed to providing a battery cell capable of ensuring safety and reliability in the event of thermal runaway of the battery cell, and a battery pack and a vehicle, which include the same.

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

[0012] According to one aspect of the present invention, a battery cell is provided comprising: an electrode assembly comprising a first electrode having a first uncoated portion, a second electrode having a second uncoated portion and a separator interposed between them; a battery housing configured to receive the electrode assembly through an opening provided on one side; and a first current collector provided in the opening and configured to electrically connect the first uncoated portion and the battery housing, wherein the first current collector may be configured so that at least a part thereof is separated from the battery housing when the internal pressure increases to a reference value or more.

[0013] A weld portion can be formed between the first Petition 870250088736, dated 09 / 30 / 2025, page 14 / 72 4 / 32 current collector and an inner surface of the battery housing, so that at least a portion of the first current collector can be soldered to the inner surface of the battery housing.

[0014] The first current collector may include a first uncoated coupling portion disposed on top of the electrode assembly and coupled to the first uncoated portion, and a plurality of housing coupling portions disposed on the inner surface of the battery housing, and at least one welding portion may be provided between at least one of the plurality of housing coupling portions and the inner surface of the battery housing.

[0015] The first current collector may also include a support disposed on top of the electrode assembly, and the first uncoated coupling portion and the plurality of housing coupling portions may be configured to extend from the support.

[0016] Each of the plurality of housing coupling portions may include a contact portion soldered onto the inner surface of the battery housing and a connection portion configured to connect the support and the contact portion.

[0017] The contact portions may be provided to be spaced from each other along a circumferential direction of the electrode array.

[0018] The welding portion may be provided in each of the plurality of housing coupling portions.

[0019] The weldable portion may include a vulnerable portion that has low weldability.

[0020] The weldability of the vulnerable portion may be approximately 10 kgf / cm2 or less.

[0021] A plurality of weld portions can be formed Petition 870250088736, dated 09 / 30 / 2025, page 15 / 72 5 / 32 between the inner surface of the battery housing and one of the plurality of housing coupling portions.

[0022] The number of weld portions formed for each housing coupling portion varies among the plurality of housing coupling portions.

[0023] The battery housing may include a crimped portion formed at one end adjacent to the opening so as to be recessed inward by pressure, and the welding portion may be provided between the crimped portion and the plurality of housing coupling portions.

[0024] The crimp portion may have a flat section parallel to a lower surface of the battery housing in at least a portion thereof, and the radial width of the weld portion may be configured to be 20% or less of the length of the flat section.

[0025] The welding portion may be provided only in some of the plurality of housing coupling portions.

[0026] The battery cell according to the present invention may further include a housing cover configured to seal the opening and which has a ventilation portion.

[0027] The battery cell according to the present invention may further include a terminal configured to penetrate the battery housing on the opposite side of the opening, so as to be electrically connected to the second uncoated portion.

[0028] The battery cell according to the present invention may further include a second current collector positioned between the electrode assembly and the terminal, and the second current collector may include a second uncoated portion coupling portion coupled to the second uncoated portion, and a terminal coupling portion coupled to the terminal. Petition 870250088736, dated 09 / 30 / 2025, page 16 / 72 6 / 32

[0029] According to another aspect of the present invention, a battery pack is provided which includes a plurality of battery cells, according to an embodiment of the present invention described above.

[0030] According to another aspect of the present invention, a vehicle is provided that includes a battery pack, according to an embodiment of the present invention described above. ADVANTAGEOUS EFFECTS OF THE INVENTION

[0031] According to one aspect of the present invention, it is possible to suppress the lateral rupture phenomenon by minimizing the high temperature and pressure applied to the side of the housing when a thermal event occurs in the battery cell, thereby ensuring the safety and reliability of the battery cell.

[0032] According to another aspect of the present invention, when a thermal event occurs in the battery cell, the current collector can be quickly separated from the housing, so that the electrode assembly is ejected from the housing, thereby minimizing heat and pressure within the housing.

[0033] Furthermore, according to another aspect of the present invention, it is possible to quickly discharge the gas or flames generated when the battery cell is in an abnormal state to the outside of the housing, while guiding their direction, thereby minimizing thermal damage to the other battery cells.

[0034] As a result, events due to thermal runaway from the battery pack or a device equipped with it, such as fire or explosion, can be avoided or delayed.

[0035] Specifically, in the case of an electric vehicle, it is possible to ensure sufficient time for occupants to escape or drive, by suppressing or delaying the propagation of thermal runaway between battery cells. Petition 870250088736, dated 09 / 30 / 2025, p. 17 / 72 7 / 32

[0036] In addition, the present invention may have several other effects, and these will be described in the respective embodiments, or the description of effects that can be easily inferred by those skilled in the art will be omitted. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] The accompanying drawings illustrate a preferred embodiment of the present invention and, together with the detailed description of the invention, serve to provide a further understanding of the technical idea of ​​the present invention and, thus, the present invention is not interpreted as being limited to the drawings.

[0038] Figure 1 is a perspective view of a battery cell, according to an embodiment of the present invention.

[0039] Figure 2 is a perspective view of an electrode assembly included in a battery cell, according to an embodiment of the present invention.

[0040] Figure 3 is a cross-sectional view of a battery cell, according to an embodiment of the present invention.

[0041] Figure 4 is a cross-sectional view that schematically illustrates the state in which a first current collector included in a battery cell is separated from the battery housing when a thermal event occurs, according to one embodiment of the present invention.

[0042] Figure 5 is a perspective view of a first current collector included in a battery cell, according to an embodiment of the present invention.

[0043] Figure 6 is a plan view illustrating the internal structure of a battery cell, according to an embodiment of the present invention.

[0044] Figure 7 is an enlarged view of part A of Figure 3, which illustrates a soldering portion included in a battery cell, of Petition 870250088736, dated 09 / 30 / 2025, page 18 / 72 8 / 32 in accordance with an embodiment of the present invention.

[0045] Figure 8 is a cross-sectional view illustrating the state in which a first current collector included in a battery cell is separated from a battery housing when a thermal event occurs, according to one embodiment of the present invention.

[0046] Figure 9 is a plan view of a battery cell, according to another embodiment of the present invention.

[0047] Figure 10 is a cross-sectional view illustrating the state in which a portion of a first current collector included in a battery cell is coupled to a battery housing, according to one embodiment of the present invention.

[0048] Figure 11 is a cross-sectional view illustrating the state in which a portion of a first current collector included in a battery cell is separated from a battery housing when a thermal event occurs, according to one embodiment of the present invention.

[0049] Figure 12 is a drawing illustrating a second current collector included in a cylindrical battery cell, according to an embodiment of the present invention.

[0050] Figure 13 is a drawing illustrating a schematic configuration of a battery pack that includes cylindrical battery cells, according to an embodiment of the present invention.

[0051] Figure 14 is a drawing illustrating a schematic configuration of a vehicle that includes a battery pack, according to an embodiment of the present invention. BEST WAY TO IMPLEMENT THE INVENTION

[0052] Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the descriptive report and appended claims do not Petition 870250088736, dated 09 / 30 / 2025, p. 19 / 72 9 / 32 should be interpreted as limited to general and dictionary meanings, but interpreted based on the meanings and concepts that correspond to the technical aspects of the present invention, based on the principle that the inventor is permitted to define the terms appropriately for the best explanation.

[0053] Therefore, the configurations proposed in the embodiments and drawings of this descriptive report indicate only the most preferable embodiment of the present invention and do not represent all the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications may be made to this invention at the time of filing the application.

[0054] Furthermore, the present invention may include several embodiments. Redundant descriptions of substantially identical or similar configurations will be omitted from the respective embodiments, and a description will be made based on the differences between them.

[0055] Meanwhile, although terms indicating directions such as up, down, left, right, forward and backward are used in this descriptive report, it is obvious to those skilled in the art that these terms are only for convenience of explanation and may vary depending on the position of the target object or the position of the observer.

[0056] For ease of explanation, the longitudinal direction of a geometric winding axis of a jelly-roll wound electrode assembly will be referred to as an axial direction in this descriptive report. Furthermore, the direction encircling the geometric winding axis will be referred to as a circumferential direction. Moreover, the direction approaching or moving away from the geometric winding axis will be referred to as a radial direction. Specifically, the direction approaching the geometric winding axis will be referred to as a centripetal direction, and the direction moving away from it will be referred to as a centripetal direction. Petition 870250088736, dated 09 / 30 / 2025, page 20 / 72 10 / 32 of the geometric axis of winding will be referred to as a centrifugal direction.

[0057] Figure 1 is a perspective view of a battery cell according to an embodiment of the present invention, Figure 2 is a perspective view of an electrode assembly included in a battery cell according to an embodiment of the present invention, and Figure 3 is a cross-sectional view of a battery cell according to an embodiment of the present invention. Furthermore, Figure 4 is a cross-sectional view that schematically illustrates the state in which a first current collector included in a battery cell is separated from the battery housing when a thermal event occurs, according to an embodiment of the present invention.

[0058] Referring to Figure 1, the battery cell 1, according to one embodiment of the present invention, includes an electrode assembly 10, a battery housing 20 and a first current collector 30. The battery cell 1 of the present invention is not limited to a specific battery cell shape and may be, for example, a cylindrical battery cell.

[0059] If the battery cell 1, according to one embodiment of the present invention, is provided as a cylindrical battery cell, referring to Figure 2, the electrode assembly 10 may include a winding hole H1 formed in the core of the electrode assembly 10. Furthermore, the electrode assembly 10 may include a first uncoated portion 11 and a second uncoated portion 12.

[0060] More specifically, the electrode assembly 10 may have a structure in which a first electrode, a second electrode, and a separator interposed between them are wound around a geometric winding axis, thereby defining a core and an outer surface. That is, the electrode assembly 10 applied to the present Petition 870250088736, dated 09 / 30 / 2025, page 21 / 72 11 / 32 The invention may be a jelly-roll type electrode assembly 10. In this case, an additional separator may be provided on the outer surface of the electrode assembly 10 for insulation from the battery housing 20. The electrode assembly 10 may have a winding structure well known in the art.

[0061] The first electrode may include a first electrode current collector and a first electrode active material applied to one or both sides of the first electrode current collector. An uncoated portion, in which the first electrode active material is not applied, may be provided at one end of the first electrode in the width direction (the direction parallel to the height direction of battery cell 1 illustrated in Figure 1). That is, the first electrode may include an uncoated portion that is not coated with an active material, so as to be exposed to the outside of the separator at a long-side end in the winding direction. The uncoated portion that functions as a first electrode tab will be referred to as a first uncoated portion 11 below.

[0062] The first uncoated portion 11 may be provided on top of the electrode assembly 10, accommodated in the battery housing 20, in the height direction (the direction parallel to the height direction of the battery cell 1 illustrated in Figure 1). That is, the first electrode may include a first uncoated portion 11 that is not coated with a layer of active material, so as to be exposed to the outside of the separator at a long-sided end, and at least a portion of the first uncoated portion 11 may be used as an electrode tab by itself. The first uncoated portion 11 may be, for example, a negative electrode tab.

[0063] The second electrode may include a second electrode current collector and a second electrode active material applied to one or both sides of the second electrode current collector. A Petition 870250088736, dated 09 / 30 / 2025, page 22 / 72 12 / 32 The uncoated portion, in which the second electrode active material is not applied, may be provided at the other end of the second electrode in the width direction (the direction parallel to the height direction of battery cell 1 illustrated in Figure 1). That is, the second electrode may include an uncoated portion that is not coated with an active material, so as to be exposed to the outside of the separator at a long-side end along the winding direction. The uncoated portion that functions as a second electrode tab will be referred to as a second uncoated portion 12 below.

[0064] The second uncoated portion 12 may be provided at the bottom of the electrode assembly 10, accommodated in the battery housing 20 in the height direction. That is, the second electrode may include a second uncoated portion 12 that is not coated with a layer of active material, so as to be exposed to the outside of the separator at a long side end, and at least a portion of the second uncoated portion 12 may be used as an electrode tab by itself. The second uncoated portion 12 may be, for example, a positive electrode tab.

[0065] Meanwhile, any active material known in the art can be used as the active material of the coated positive electrode in the positive electrode current collector and the active material of the coated negative electrode in the negative electrode current collector in the present invention, without limitation.

[0066] At least part of the first uncoated portion 11 may include a plurality of segments 11a split along the winding direction of the electrode assembly 10. In this case, the plurality of segments 11a may be bent in the radial direction of the electrode assembly 10.

[0067] Referring to Figure 2, the uncoated portions 11 and 12 can be bent in the radial direction of the electrode assembly 10, by Petition 870250088736, dated 09 / 30 / 2025, page 23 / 72 13 / 32 example, from the outer circumference towards the core. In this case, the plurality of segments 11a of the first uncoated folded portion 11 can overlap in multiple layers to form a folded surface. In this case, a current collector 30, to be described later, can be placed on the folded surface of the first uncoated portion 11 and then welded in a certain area. This structure of the first electrode can be applied to the second electrode in the same way.

[0068] Meanwhile, referring to Figures 1 to 4, the battery housing 20 may have an opening formed on one side in the vertical direction (the direction parallel to the geometric Z axis). The battery housing 20 may receive the electrode assembly 10 through the opening. That is, the battery housing 20 may have an upper opening and a closed lower portion in the vertical direction. The battery housing 20 may be a substantially cylindrical container and may include a conductive metal.

[0069] Referring to Figures 1 and 2, the first current collector 30 included in the battery cell 1, according to one embodiment of the present invention, can be configured to be electrically connected to the electrode assembly 10 and the battery housing 20. That is, the first current collector 30 can electrically connect the electrode assembly 10, for example, the first uncoated portion 11, and the battery housing 20. The first current collector 30 can be accommodated within the battery housing 20 and can be provided in the opening. In this case, the first current collector 30 can be coupled to the inner surface of the battery housing 20.

[0070] As in the embodiment illustrated in Figure 4, the first current collector 30 can be configured so that at least part of it is separated from the battery housing 20 if the internal pressure increases to a reference value or more due to a Petition 870250088736, dated 09 / 30 / 2025, page 24 / 72 14 / 32 Thermal event. Only a portion of the first current collector 30 can be separated from the battery housing 20, or the entirety of the first current collector 30 can be separated from the battery housing 20. According to the above implemented configuration of the present invention, before the high pressure generated due to a thermal event occurring within the battery housing 20 ruptures the lateral surface of the battery housing 20, at least a portion of the first current collector 30 can be separated from the battery housing 20 by gas pressure or similar, forming an opening. That is, when a thermal event occurs, at least a portion of the first current collector 30 can be separated from the battery housing 20, thereby providing a space through which the gas, flame and / or electrode assembly 10 can move.

[0071] When at least part of the first current collector 30 is separated from the battery housing 20, the first current collector 30 may have an inverted shape, compared to that in a normal state, as illustrated in Figure 4. That is, in the normal state, a portion (housing coupling portion 32 to be described below) of the first current collector 30, which is coupled to the battery housing 20, may be positioned higher than a portion (first uncoated portion coupling portion 31 to be described below) of the first current collector 30, which is coupled to the first uncoated portion 11.On the other hand, when a thermal event occurs, a portion (the first uncoated portion coupling portion 31 to be described below) of the first current collector 30, which is coupled to the first uncoated portion 11, may rise so that the portion of the first current collector 30, which is coupled to the first uncoated portion 11, is positioned higher than a portion (the housing coupling portion 32 to be described below). Petition 870250088736, dated 09 / 30 / 2025, page 25 / 72 15 / 32 crita) of the first current collector 30, which is coupled to the battery housing 20.

[0072] For example, so that at least part of the first current collector 30 is easily separated from the battery housing 20, the first current collector 30 can be soldered to the battery housing 20 with a weak soldering force. Alternatively, the first current collector 30 can be partially soldered to the battery housing 20.

[0073] When a thermal event, such as thermal runaway, occurs within the battery housing 20, a side rupture phenomenon may occur, whereby the side of the battery housing 20 is destroyed due to high temperature and pressure, such as gas or flame. According to the above implemented configuration of the present invention, when a thermal event occurs in the battery cell 1, the first current collector 30 can be quickly separated from the battery housing 20, so that the electrode assembly 10 can be quickly ejected from the battery housing. Consequently, the high temperature and pressure applied to the inner surface of the battery housing 20 can be minimized, thereby suppressing the occurrence of the side rupture phenomenon and ensuring the safety and reliability of the battery cell 1.

[0074] Furthermore, according to the above implemented configuration of the present invention, the gas or flame is rapidly discharged out of the battery housing 20 while being guided in a direction towards the opening rather than the side of the battery housing 20, so that thermal damage to other battery cells can be minimized.

[0075] More specifically, at least a portion of the first current collector 30 can be coupled to the inner surface of the battery housing 20. For example, at least a portion of the first Petition 870250088736, dated 09 / 30 / 2025, page 26 / 72 16 / 32 current collector 30 and the inner surface of the battery housing 20 can be welded together. Therefore, as illustrated in Figure 3, a weld portion W can be formed between at least a portion of the first current collector 30 and the inner surface of the battery housing 20. For example, laser welding, ultrasonic welding, or spot welding can be applied to weld the battery housing 20 and the first current collector 30. After inserting the electrode assembly 10 into the battery housing 20 through the opening, the battery housing 20 and at least a portion of the first current collector 30 can be pre-welded.

[0076] Figure 5 is a perspective view of a first current collector included in a battery cell, according to an embodiment of the present invention.

[0077] Referring to Figure 5, in addition to Figure 3, the first current collector 30, according to one embodiment of the present invention, will be described in detail. The first current collector 30 may include a first uncoated coupling portion 31 and a housing coupling portion 32.

[0078] The first uncoated portion coupling portion 31 can be arranged on top of the electrode assembly 10 and coupled to the first uncoated portion 11. One or more first uncoated portion coupling portions 31 can be provided. The first uncoated portion coupling portion 31 can be coupled to the first uncoated portion 11 by welding, for example, in the radial direction of the electrode assembly 10.

[0079] The housing coupling portion 32 may be disposed on the inner surface of the battery housing 20. One or more housing coupling portions 32 may be provided. For example, as illustrated in Figure 5, the first current collector 30 may include a plurality of housing coupling portions. Petition 870250088736, dated 09 / 30 / 2025, page 27 / 72 17 / 32 32.

[0080] One or more first uncoated portion coupling portions 31 and the plurality of housing coupling portions 32 may be arranged, for example, approximately in a radial form, in a cross form or a combination thereof around the center of the first current collector 30. In another aspect, each of the plurality of housing coupling portions 32 may be arranged between adjacent first uncoated portion coupling portions 31.

[0081] In this case, at least one of the plurality of housing coupling portions 32 can be welded to the inner surface of the battery housing 20. That is, at least one welding portion W can be provided between at least one of the plurality of housing coupling portions 32 and the inner surface of the battery housing 20.

[0082] Meanwhile, the first current collector 30 may still include a support portion 33. The support portion 33 may be disposed on top of the electrode assembly 10. The first uncoated coupling portions 31 and the plurality of housing coupling portions 32 may be configured to extend from the support portion 33.

[0083] The first uncoated coupling portion 31 and the housing coupling portion 32 can be indirectly connected through the support portion 33, instead of being directly connected to each other. According to the above implemented configuration of the present invention, when an external impact is applied to the cylindrical battery 1 of the present invention, the possibility of damage to the coupling portion between the first current collector 30 and the electrode assembly 10 and to the coupling portion between the pri Petition 870250088736, dated 09 / 30 / 2025, page 28 / 72 18 / 32 current collector 30 and battery housing 20 can be minimized.

[0084] The first uncoated portion coupling portions 31 can be configured to extend approximately radially from the support portion 33 towards the side wall of the battery housing 20. The first uncoated portion coupling portions 31 can be positioned apart from each other along the perimeter of the support portion 33.

[0085] The plurality of housing coupling portions 32 can be configured to extend approximately radially from the support portion 33 towards the side wall of the battery housing 20. The respective housing coupling portions 32 can be positioned apart from each other along the perimeter of the support portion 33.

[0086] In order to ensure bonding resistance by increasing the bonding area between the first current collector 30 and the electrode assembly 10 and reducing electrical resistance, the support portion 33, as well as the first uncoated coupling portion 31, can be coupled to the first uncoated portion 11. The support portion 33 and the first uncoated portion 11 can be coupled by welding.

[0087] Each of the plurality of housing coupling portions 32 may include a contact portion 32a and a connection portion 32b. The contact portion 32a may be welded to the inner surface of the battery housing 20. A plurality of contact portions 32a may be provided, and at least one of the plurality of contact portions 32a may be welded to the inner surface of the battery housing 20. The plurality of contact portions 32a may be provided to be spaced from each other along the circumferential direction of the electrode assembly 10. Petition 870250088736, dated 09 / 30 / 2025, page 29 / 72 19 / 32

[0088] The connection portion 32b can be configured to connect the support portion 33 and the contact portion 32a. The connection portion 32b can be arranged so that at least one portion of it is in contact with the first uncoated portion 11.

[0089] Meanwhile, referring to Figure 5, the support portion 33 may have a current collector hole H2 formed in a position that corresponds to the winding hole H1 formed approximately in the center of the electrode assembly 10. The winding hole H1 and the current collector hole H2, which communicate with each other, may function as a passage for the insertion of a welding rod or for the irradiation of a laser beam to weld a terminal 50 and a second current collector 60, which will be described below, or to weld the terminal 50 and a conductor tab (not shown).

[0090] Furthermore, the first current collector 30 of the present invention may have at least one injection hole H3. The injection hole H3 may be provided in the first uncoated coupling portion 31. Thus, in the manufacture of the battery cell 1 according to an embodiment of the present invention, an assembly including the electrode assembly 10 and the first current collector 30 may be received within the battery housing 20, and then an electrolyte may be injected. In this case, the injection performance may be improved by means of the injection hole H3.

[0091] Figure 6 is a plan view of a battery cell according to an embodiment of the present invention, and Figure 7 is an enlarged view of part A of Figure 3, which illustrates a soldering portion included in a battery cell according to an embodiment of the present invention. Furthermore, Figure 8 is a cross-sectional view illustrating the state in which a first current collector included in a battery cell is separated from a housing. Petition 870250088736, dated 09 / 30 / 2025, page 30 / 72 20 / 32 of battery power when a thermal event occurs, according to one embodiment of the present invention.

[0092] According to one embodiment of the present invention, as illustrated in Figure 6, the welding portion W can be provided in each of the plurality of housing coupling portions 32. That is, all contact portions 32a of the plurality of housing coupling portions 32 can be welded to the inner surface of the battery housing 20.

[0093] According to the above implemented configuration of the present invention, the coupling between the first current collector 30 and the battery housing 20 can be stably maintained in a normal state. Furthermore, when a thermal event occurs, at least a part of the first current collector 30 can be easily separated from the battery housing 20, thereby ensuring the thermal stability of the battery cell 1.

[0094] In this case, the weldable portion W may include a vulnerable portion V that has low weldability. Preferably, the weldability of the vulnerable portion V may be approximately 10 kgf / cm2 or less. Furthermore, preferably, the weldability of the vulnerable portion V may be approximately more than 0 kgf / cm2.

[0095] As shown in Figure 6, the vulnerable portion V can be provided between all the housing coupling portions 32 and the inner surface of the battery housing 20, respectively. In this case, as shown in Figure 8, if the internal pressure of the battery housing 20 reaches a reference value or higher due to a thermal event occurring therein, the first current collector 30 can be separated from the battery housing 20.

[0096] According to the above implemented configuration of the present invention, when a thermal event occurs, the first collector of Petition 870250088736, dated 09 / 30 / 2025, page 31 / 72 21 / 32 current 30 entire is completely separated from the battery housing 20 to form an opening, so that the electrode assembly 10 can be ejected more easily through the opening. Therefore, according to the above implemented configuration of the present invention, when a thermal event occurs, the heat and pressure inside the battery housing 20 can be effectively discharged to the outside of the battery housing 20.

[0097] Unlike the embodiment above, the vulnerable portion V can be provided in only some of the plurality of welding portions W between all the plurality of housing coupling portions 32 and the inner surface of the battery housing 20. That is, the connection resistance between the housing coupling portion 32 and the inner surface of the battery housing 20 can vary between the couplings themselves. In this case, when a thermal event occurs, only a part of the first current collector 30 can be separated from the battery housing 20, forming an opening.

[0098] Referring to Figures 6 and 7, a plurality of welding portions W can be provided between the inner surface of the battery housing 20 and one of the plurality of housing coupling portions 32. In this case, the plurality of welding portions W can be configured in a certain welding pattern. The number of welding portions W formed in a housing coupling portion 32 can vary among the plurality of housing coupling portions 32. That is, the bonding resistance between the housing coupling portion 32 and the inner surface of the battery housing 20 can vary among the couplings thereof. In other words, the bonding force between some of the plurality of housing coupling portions 32 and the inner surface of the battery housing 20 can be configured to be weaker than the bonding force. Petition 870250088736, dated 09 / 30 / 2025, page 32 / 72 22 / 32 between the remaining housing coupling portions 32 and the inner surface of the battery housing 20.

[0099] For example, four housing coupling portions 32 can be provided such that three welding portions W are provided between two of the four housing coupling portions 32 and the inner surface of the battery housing 20, respectively, and such that two welding portions W are provided between the two remaining housing coupling portions 32 and the inner surface of the battery housing 20, respectively. Therefore, the bonding force between the two remaining housing coupling portions 32 and the inner surface of the battery housing 20 can be configured to be smaller. In this case, when a thermal event occurs, only a portion of the first current collector 30 can be separated from the battery housing 20, so that the opening remains open.

[0100] Meanwhile, referring to Figure 7, the battery housing 20 may include a crimp portion 21.The crimp portion 21 can be formed on top of the electrode assembly 10. The crimp portion 21 can be formed inwards to be recessed by pressing one end of the battery housing 20 adjacent to the opening. More specifically, the crimp portion 21 can be provided between the opening formed on one side of the battery housing 20 and a receiving portion that receives the electrode assembly 10. The crimp portion 21 can be configured so that the outer circumference of the battery housing 20 is pressed inwards to a predetermined depth. The vertical distance from the inner surface of the battery housing 20 to the innermost point of the crimp portion 21 can be defined as a pressing depth PD. As a result, the inner diameter of the battery housing 20 in the area where the crimp portion 21 is formed can be smaller than the diameter of the electrode assembly 10.

[0101] The 21 crimp portion can prevent the electrode assembly. Petition 870250088736, dated 09 / 30 / 2025, p. 33 / 72 23 / 32 10, which may have a size approximately corresponding to the inner diameter of the battery housing 20, jumps through the opening formed in the top of the battery housing 20, and may function as a support on which the first current collector 30 is seated. The crimp portion 21 may function as a support for attaching a housing cover 40 or a sealing gasket G1, which will be described later, as well as the first current collector 30.

[0102] In the case where the crimp portion 21 is formed in the battery housing 20, the housing coupling portion 32 may be coupled to the crimp portion 21. In this case, the contact portion 32a may be welded to the crimp portion 21. That is, the welding portion W may be provided between the crimp portion 21 and at least one of the plurality of housing coupling portions.Both the trim portion 21 and the contact portion 32a can be configured to extend in a direction approximately parallel to the lower surface of the battery housing 20, that is, a direction approximately perpendicular to the side wall of the battery housing 20.

[0103] According to the above implemented configuration of the present invention, when coupling the housing coupling portion 32 to the crimp portion 21, the bonding resistance between the housing coupling portion 32 and the crimp portion 21 can be increased, and the resistance reduction effect can be increased according to the increase in the contact area.

[0104] The crimp portion 21 may have a flat section F in at least one part, which is parallel to the lower surface of the battery housing 20. The flat section F may be formed on the upper surface of the crimp portion 21. The housing coupling portion 32, that is, the contact portion 32a, may be welded to the flat section F.

[0105] The length of the flat section F of the frieze portion 21 in contact with the first current collector 30 can be obtained from OV Petition 870250088736, dated 09 / 30 / 2025, page 34 / 72 24 / 32 R1. Referring to Figure 7, the shortest distance from the end of the contact portion 32a to the vertical line passing through the innermost point of the crimp portion 21 can be defined as an overlap length OV. The length of the flat section F can correspond to the length obtained by subtracting the radius of curvature R1 of the crimp portion 21 from the overlap length OV. The weld area between the contact portion 32a and the crimp portion 21 can be formed to be smaller than the length of the flat section F.

[0106] The radial width WD of the welding portion W can be configured to be 20% or less of the length of the flat section F. If the above ratio satisfies the above range, the welding resistance between the first current collector 30 and the crimping portion 21 of the battery housing 20 can be reduced. Consequently, when a thermal event occurs in the battery cell 1, the first current collector 30 can be quickly separated from the battery housing 20, so that the electrode assembly 10 can be smoothly ejected from the battery housing 20. Therefore, the heat and pressure inside the battery housing 20 can be minimized, so that the thermal stability of the battery cell 1 can be ensured.

[0107] Figure 9 is a plan view of a battery cell according to another embodiment of the present invention, and Figure 10 is a cross-sectional view illustrating the state in which a portion of a first current collector included in a battery cell is coupled to the battery housing, according to an embodiment of the present invention. Furthermore, Figure 11 is a cross-sectional view illustrating the state in which a portion of a first current collector included in a battery cell is separated from the battery housing when a thermal event occurs, according to an embodiment of the present invention. Petition 870250088736, dated 09 / 30 / 2025, page 35 / 72 25 / 32

[0108] The welding portion W can be provided only in some of the plurality of housing coupling portions 32. For example, as shown in Figure 9 and Figure 10, four housing coupling portions 32 can be provided, and the welding portion W can be provided only between one of the four housing coupling portions 32 and the inner surface of the battery housing 20. The total number of housing coupling portions 32 and the number of welding portions W can be configured differently from the embodiment above.

[0109] In this case, as shown in Figure 11, when a thermal event occurs, only a portion of the first current collector 30, i.e., the housing coupling portions 32 without the welding portion W, can be separated from the battery housing 20, so that the opening remains open. As a result according to the above implemented configuration of the present invention, when a thermal event occurs in the battery cell 1, a portion of the first current collector 30 can be quickly separated from the battery housing 20, so that the electrode assembly 10 can be smoothly ejected from the battery housing 20. Therefore, the heat and pressure inside the battery housing 20 can be minimized, so that the thermal stability of the battery cell 1 can be ensured.

[0110] Referring to Figure 1, Figure 3 and Figure 4, the battery cell according to an embodiment of the present invention may further include a housing cover 40.The housing cover 40 can be configured to seal the opening formed on one side of the battery housing 20. The housing cover 40 can be secured by a crimping portion 22 formed on top of the battery housing 20. In this case, a sealing gasket G1 can be interposed between the battery housing 20 and the housing cover 40 and between the current collector 30 and the housing cover 40, so as to... Petition 870250088736, dated 09 / 30 / 2025, p. 36 / 72 26 / 32 improve the clamping force and sealing of the battery housing 20.

[0111] The crimp portion 21 may provide a support surface on which the housing cover 40 may be seated. The upper surface of the crimp portion 21 may be configured to extend in a direction approximately parallel to the lower surface of the battery housing 20, that is, in a direction approximately perpendicular to the side wall of the battery housing 20, so as to stably support the edge of the housing cover 40.

[0112] Meanwhile, the battery housing 20 may still include a crimping portion 22. The crimping portion 22 may be formed above the crimping portion 21. The crimping portion 22 may be configured to extend and form a band so as to encircle the edge of the housing cover 40 disposed in the crimping portion 21. The housing cover 40 may be attached to the crimping portion 21 by the crimping portion 22 configured above. The crimping portion 22 may be omitted, and the housing cover 40 may be attached while covering the opening of the battery housing 20 by means of another fastening structure.

[0113] The housing cover 40 may have a vent portion 41 formed to prevent an increase in internal pressure due to gas generated within 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 reference value or more. For example, the vent portion 41 may be an area formed in a portion of the housing cover 40 to be structurally vulnerable, compared to the surrounding area, so as to be easily ruptured when internal pressure is applied. The vent portion 41 may be, for example, an area that is thinner than the surrounding area. Referring to Figure 1 and Figure 3, the vent portion 41 may form a closed loop in an approximately circular shape. Petition 870250088736, dated 09 / 30 / 2025, page 37 / 72 27 / 32

[0114] According to the above implemented configuration of the present invention, as shown in Figure 4, Figure 8 and Figure 12, if the internal pressure of the battery housing 20 increases to a reference value or more due to a thermal event occurring therein, the vent portion 41 may be ruptured, so that at least a part of the first current collector 30 may be separated from the battery housing 20. In this case, only the connection portion 32b, the first uncoated coupling portion 31 and the support portion 33 may be forced outwards towards the vent portion 41. As a result, the first current collector 30 may have a shape that is inverted, compared to that in the normal state.According to the above implemented configuration of the present invention, the first current collector 30 can be separated from the electrode assembly 10 to have an inverted shape, thereby discharging high temperature and pressure heat through the ventilation portion 41.

[0115] Meanwhile, referring to Figure 3, terminal 50 can penetrate the opposite side of the battery housing opening 20, so as to be electrically connected to the second uncoated portion 12 of the electrode assembly 10. Terminal 50 can penetrate approximately the center of the lower surface of the battery housing 20.

[0116] Meanwhile, in the present invention, the outer surface 20a of the closed portion, located on the opposite side of the opening provided at the top of the battery housing 20, can function as a first electrode terminal T1. If the first uncoated portion 11 is a negative electrode tab, the first electrode terminal T1 can be a negative electrode terminal.

[0117] The battery cell 1 according to the present invention has a structure in which the terminal 50 exposed through the lower surface opposite the opening of the battery housing 20 can be used Petition 870250088736, dated 09 / 30 / 2025, p. 38 / 72 28 / 32 as a second electrode terminal T2, and in which the remaining area of ​​the lower surface of the battery housing 20, excluding the area occupied by terminal 50 (including the area where the insulating gasket G2 is exposed in the case where the insulating gasket G2 is exposed to the outside of terminal 50 through the outer surface 20a of the closed portion), can be used as the first electrode terminal T1.

[0118] Therefore, the battery cell 1 according to the present invention can simplify the electrical connection structure by connecting both the positive and negative electrodes in one direction when electrically connecting multiple battery cells 1. Furthermore, the battery cell 1 according to the present invention has a structure in which most of the lower surface opposite the opening of the battery housing 20 can be used as the electrode terminal, thereby ensuring a sufficient area for soldering components for electrical connection.

[0119] Figure 12 is a drawing illustrating a second current collector included in a cylindrical battery cell, according to an embodiment of the present invention.

[0120] Referring to Figure 12, in addition to Figure 1, a second current collector 60 may be coupled to the bottom of the electrode assembly 10. The second current collector 60 may include a conductive metallic material and may be electrically coupled to the second uncoated portion 12. The second current collector 60 may be coupled to a coupling surface (bending surface) formed by bending the end of the second uncoated portion 12 in a direction parallel to the current collector 60. This is the same as the first uncoated portion 11 described above.

[0121] The second current collector 60 may include an edge portion 61 and a second uncoated portion coupling 62. The edge portion 61 may be disposed under the assembly of Petition 870250088736, dated 09 / 30 / 2025, page 39 / 72 29 / 32 electrodes 10 and can be configured substantially in the form of a border with an empty space S formed therein. Although Figure 12 in the present invention shows only the border portion 61 in the form of a circular border, the present invention is not limited to this. Alternatively, the border portion 61 can be configured as an approximately square shape, a hexagonal shape, an octagonal shape, or other shapes.

[0122] The second uncoated portion coupling 62 may extend into the edge portion 61, so as to be coupled to the second uncoated portion 12.

[0123] Meanwhile, for example, terminal 50 can be coupled to the second current collector 60 connected to the second uncoated portion 12 or it can be coupled to a conductor tab (not shown) connected to the second uncoated portion 12, so as to be electrically connected to the electrode assembly 10.

[0124] In this case, the current collector (second current collector) 60 may include a terminal coupling portion 63. The terminal coupling portion 63 may be spaced from the second uncoated coupling portion 62. The terminal coupling portion 63 may be positioned within the edge portion 61. The terminal coupling portion 63 may be coupled to the terminal 50 by soldering. The terminal coupling portion 63 may have a diameter substantially equal to or greater than the diameter of a flat portion formed on the lower surface of the terminal 50, so as to ensure a soldering area for coupling with the flat portion formed on the lower surface of the terminal 50. The terminal coupling portion 63 may be positioned, for example, approximately in the center of the internal space surrounded by the edge portion 61. The terminal coupling portion 63 may be arranged in a position that corresponds to the winding hole H1 formed Petition 870250088736, dated 09 / 30 / 2025, p. 40 / 72 30 / 32 in the core of electrode array 10.

[0125] The second uncoated coupling portion 62 and the terminal coupling portion 63 are arranged to be spaced apart from each other, rather than being directly connected to each other, and are electrically connected by the edge portion 61. As described above, the current collector 60 of the present invention has a structure in which the uncoated coupling portion 62 and the terminal coupling portion 63 are indirectly connected through the edge portion 6, rather than being directly connected to each other, so that when an impact and / or vibration is applied to the battery cell 1, the impact applied to the coupling portion between the uncoated coupling portion 62 and the second uncoated portion 12 and the coupling portion between the terminal coupling portion 63 and the terminal 50 can be dispersed.Therefore, the current collector 60 of the present invention can minimize or prevent damage to the weld portion due to external impact.

[0126] The current collector 60 may also include a bridge portion 64 that extends into the edge portion 61 to be connected to the terminal coupling portion 63.

[0127] A plurality of second uncoated portion coupling portions 62 and / or a plurality of bridge portions 64 may be provided. The number of second uncoated portion coupling portions 62 and / or bridge portions 64 may be determined in consideration of the required resistance level for the battery cell 1, the required opening ratio for the current collector 60, or the like.

[0128] Meanwhile, the second uncoated portion 12 and / or the second current collector 60 may remain in a state of isolation from the battery housing 20. For this purpose, an insulator 70 may be interposed between the second uncoated portion 12 and the housing. Petition 870250088736, dated 09 / 30 / 2025, page 41 / 72 31 / 32 of battery 20 and / or between the second current collector 60 and the battery housing 20. In the case where the insulator 70 is applied, the terminal 50 can penetrate the insulator 70 for electrical connection with the second uncoated portion 12.

[0129] Figure 13 is a drawing illustrating a schematic configuration of a battery pack that includes cylindrical battery cells according to an embodiment of the present invention.

[0130] Referring to Figure 13, a battery assembly 3, according to an embodiment of the present invention, may include a battery cell assembly in which a plurality of battery cells 1, according to an embodiment of the present invention described above, are electrically connected, and an assembly housing 2 that accommodates the same.

[0131] The plurality of battery cells 1 can be accommodated within the assembly housing 2 with the ventilation portion 41 facing downwards. According to the above implemented configuration of the present invention, if the battery pack 3 is mounted in a vehicle or similar, the electrode assembly 10 can be prevented from moving towards the conductor located above when a thermal event occurs in the battery cell 1.

[0132] Meanwhile, the battery pack 3, according to one embodiment of the present invention, may also include components such as a busbar for electrical connection, a cooling unit and a power terminal, which have been omitted from the drawing for convenience.

[0133] Figure 14 is a drawing illustrating a schematic configuration of a vehicle that includes a battery pack, according to an embodiment of the present invention.

[0134] Referring to Figure 14, a vehicle 5, according to a mo Petition 870250088736, dated 09 / 30 / 2025, p. 42 / 72 32 / 32 The present invention may, for example, be an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack 3, according to one embodiment of the present invention. The vehicle 5 may include a four-wheeled vehicle and a two-wheeled vehicle. The vehicle 5 may operate by receiving energy from the battery pack 3, according to one embodiment of the present invention.

[0135] As described above, although the present invention has been described with reference to limited embodiments and designs, the present invention is not limited thereto, and various modifications and variations are possible within the technical idea of ​​the present invention and the scope of equivalence of the claims to be described below by those skilled in the art to which the present invention pertains. Petition 870250088736, dated 09 / 30 / 2025, p. 43 / 72

Claims

1 / 4 CLAIMS 1. Battery cell characterized in that it comprises: an electrode assembly comprising a first electrode having a first uncoated portion, a second electrode having a second uncoated portion and a separator interposed between them; a battery housing configured to receive the electrode assembly through an opening provided on one side; and a first current collector provided in the opening and configured to electrically connect the first uncoated portion and the battery housing, wherein the first current collector is configured so that at least a part thereof is separated from the battery housing when the internal pressure increases to a reference value or more.

2. Battery cell according to claim 1, characterized in that a welded portion is formed between the first current collector and an inner surface of the battery housing, such that at least a portion of the first current collector is welded to the inner surface of the battery housing.

3. Battery cell according to claim 2, characterized in that the first current collector comprises a first uncoated coupling portion disposed on one top of the electrode assembly and coupled to the first uncoated portion, and a plurality of housing coupling portions disposed on the inner surface of the battery housing, and wherein at least one welding portion is provided between at least one of the plurality of housing coupling portions and the inner surface of the battery housing.

4. Battery cell according to claim 3, characterized in that the first current collector further comprises a support portion disposed on top of the electrode assembly, and in that the first uncoated coupling portion and the plurality of housing coupling portions are configured to extend from the support portion.

5. Battery cell according to claim 4, characterized in that each of the plurality of housing coupling portions comprises a contact portion soldered onto the inner surface of the battery housing and a connection portion configured to connect the support portion and the contact portion.

6. Battery cell according to claim 5, characterized in that the contact portions are provided to be spaced from each other along a circumferential direction of the electrode assembly.

7. Battery cell according to claim 3, characterized in that the welding portion is provided in each of the plurality of housing coupling portions.

8. Battery cell according to claim 7, characterized in that the welding portion comprises a vulnerable portion that has low weldability.

9. Battery cell according to claim 8, characterized in that the welding resistance of the vulnerable portion is approximately 10 kgf / cm2 or less. Petition 870250088736, dated 09 / 30 / 2025, pp. 63 / 72 3 / 4 10. Battery cell according to claim 7, characterized in that a plurality of welding portions is formed between the inner surface of the battery housing and one of the plurality of housing coupling portions.

11. Battery cell according to claim 10, characterized in that the number of solder portions formed for each housing coupling portion varies among the plurality of housing coupling portions.

12. Battery cell according to claim 7, characterized in that the battery housing comprises a crimped portion formed at one end adjacent to the opening so as to be recessed inward by pressure, and wherein the welding portion is provided between the crimped portion and the plurality of housing coupling portions.

13. Battery cell according to claim 12, characterized in that the crimp portion has a flat section parallel to a lower surface of the battery housing in at least a portion thereof, and wherein a radial width of the welding portion is configured to be 20% or less of a length of the flat section.

14. Battery cell according to claim 3, characterized in that the welding portion is provided only in some of the plurality of housing coupling portions.

15. Battery cell according to claim 1, characterized in that it further comprises a housing cover configured to seal the opening and that it has a ventilation portion.

16. Battery cell according to claim 1, characterized in that it further comprises a terminal configured to penetrate the battery housing on an opposite side of the opening, so as to be electrically connected to the second uncoated portion.

17. Battery cell according to claim 16, characterized in that it further comprises a second current collector positioned between the electrode assembly and the terminal, wherein the second current collector comprises a second uncoated portion coupling portion coupled to the second uncoated portion and a terminal coupling portion coupled to the terminal.

18. Battery pack characterized in that it comprises a plurality of battery cells, as defined in any one of claims 1 to 17.

19. Vehicle characterized by the fact that it comprises a battery pack, as defined in claim 18. Petition 870250088736, dated 09 / 30 / 2025, pp. 65 / 72

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