Battery cell, battery pack and vehicle including same

Abstract

A battery cell according to the present invention comprises: an electrode assembly which is provided while being wound around the center axis of a winding center hole, with a separator interposed between a first electrode and a second electrode; a can housing which accommodates the electrode assembly and has an opening portion at one end portion thereof; and a can lead which comprises a plurality of electrode coupling portions that are coupled to the electrode assembly and spaced apart from one another, and is coupled to one end portion of the can housing, wherein the plurality of electrode coupling portions are each provided with a welding coupling portion which is a portion to be welded to the electrode assembly and is configured such that a first width in a direction perpendicular to the radial direction is greater than or equal to a second width in the radial direction.

Description

Battery cells, battery packs, and automobiles including the same

[0001] The present invention relates to a battery cell, a battery pack, and an automobile including the same, and more specifically, to a battery cell, a battery pack, and an automobile including the same with improved weldability.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2025-0011781 filed on January 24, 2025, and all contents disclosed in the specification of said application are incorporated into this application by reference.

[0003] Recently, as the demand for portable electronic products such as laptops, video cameras, and mobile phones has increased rapidly, and the development of electric vehicles, energy storage batteries, robots, and satellites has accelerated, research on high-performance secondary batteries capable of repeated charging and discharging is actively underway.

[0004] Currently commercialized rechargeable batteries include nickel-cadmium batteries, nickel-hydrogen batteries, nickel-zinc batteries, and lithium-ion batteries. Among these, lithium-ion batteries are gaining attention for their advantages, such as the ability to freely charge and discharge with almost no memory effect compared to nickel-based batteries, a very low self-discharge rate, and high energy density.

[0005] These lithium-ion secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. Additionally, the lithium-ion secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing that seals and encloses the electrode assembly together with an electrolyte.

[0006] Meanwhile, lithium-ion rechargeable batteries can be classified according to the shape of the battery case into pouch-type rechargeable batteries, in which the electrode assembly is embedded in an aluminum laminate sheet pouch, and can-type rechargeable batteries, in which the electrode assembly is embedded in a metal can. Furthermore, can-type rechargeable batteries can be further classified into cylindrical batteries and prismatic batteries depending on the shape of the metal can. These lithium-ion rechargeable batteries are utilized as battery modules or battery packs, in which multiple battery cells are assembled into a dense structure by overlapping or stacking them to provide high voltage and high current, and then electrically connected.

[0007] A battery cell may include an electrode assembly provided by being wound with a separator interposed between the electrodes, and a can housing that accommodates the electrode assembly. Additionally, the conventional battery cell may have a beading section and a crimping section. The beading section was formed in an indented shape on the side of the opening of the can housing to secure the electrode assembly and adjust the form factor of the battery cell, and the crimping section was a bent and extended section to seal the opening.

[0008] Meanwhile, recently, in order to improve space efficiency and energy density and increase productivity, battery cells that do not have parts such as the beading and crimping sections mentioned above (hereinafter referred to as conventional battery cells) are being developed. Such conventional battery cells could include a component such as a can lid that is coupled to the end of the opening of the can housing.

[0009] The above can lid may be configured to be welded together with the electrode assembly. However, the can lid of a conventional battery cell is difficult to adhere to the electrode assembly due to tilting or uneven flatness, which poses a high risk of welding defects such as over-welding or under-welding. Furthermore, because the welding area is not sufficiently secured, the welding strength may be low. Therefore, there is an urgent need to develop a battery cell that includes a can lid while having improved weldability.

[0010] The present invention was conceived in consideration of the technical background described above, and has one objective of providing a battery cell with improved weldability, a battery pack, and an automobile including the same.

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

[0012] A battery cell according to the present invention comprises: an electrode assembly provided by being wound around the central axis of a winding center hole with a separator interposed between a first electrode and a second electrode; a can housing that accommodates the electrode assembly and has an opening formed at one end; and a can lid that is coupled to one end of the can housing and has a plurality of electrode coupling parts spaced apart from each other and coupled to the electrode assembly, wherein each of the plurality of electrode coupling parts is a part for being welded to the electrode assembly and has a welded coupling part configured such that the length of a first width along a direction perpendicular to the radial direction is greater than or equal to the length of a second width along the radial direction.

[0013] The above welded joint can be formed over the entire area of ​​the electrode joint.

[0014] The above welded joint can be provided in a flat shape.

[0015] The above electrode coupling part may be provided in three parts.

[0016] A plurality of the above electrode coupling portions can be formed and arranged radially and rotationally symmetrically.

[0017] The above can lid may further comprise a plurality of spacing portions disposed between any two adjacent electrode coupling portions and spaced apart from the electrode assembly.

[0018] When viewed from the direction of the central axis of the winding center hole, the total area of ​​the welded joint can be formed to be larger than the total area of ​​the spaced-out portion.

[0019] The can lid may further comprise an injection port that opens toward the interior of the can housing; and a flat portion that surrounds the injection port and is spaced apart from the electrode assembly.

[0020] The flat portion above has a folded portion formed by being sunken toward the injection port, and the electrode coupling portion may further have a first extension portion extended toward the folded portion.

[0021] The above electrode coupling portion may further include a second extension portion extended in the circumferential direction.

[0022] The above can lid may further have a plurality of bridges that extend radially and are formed to partition any two adjacent electrode coupling portions.

[0023] The above can lid further comprises an edge portion formed at the edge so as to be coupled to the can housing, and the edge portion may be configured to be deformable in a direction parallel to the radial direction.

[0024] The above can lid may further have a vent notch formed by notching between the edge and the electrode coupling portion.

[0025] A battery pack according to the present invention comprises at least one battery cell according to the present invention.

[0026] The automobile according to the present invention includes at least one battery pack according to the present invention.

[0027] According to the present invention, a battery cell with improved weldability, a battery pack, and an automobile including the same can be provided.

[0028] In addition, according to one aspect of the present invention, a battery cell with improved quality, a battery pack, and a vehicle including the same can be provided.

[0029] In addition, according to one aspect of the present invention, a battery cell, a battery pack, and an automobile including the same can be provided, with improved structural rigidity and stability.

[0030] In addition, according to one aspect of the present invention, a battery cell having low electrical resistance, a battery pack, and an automobile including the same can be provided.

[0031] In addition, according to one aspect of the present invention, a battery cell with improved energy density, a battery pack, and a vehicle including the same can be provided.

[0032] In addition, according to one aspect of the present invention, a battery cell with improved productivity, a battery pack, and an automobile including the same can be provided.

[0033] In addition, according to one aspect of the present invention, a battery cell capable of effective venting, a battery pack, and an automobile including the same can be provided.

[0034] In addition, according to one aspect of the present invention, a battery cell, a battery pack, and an automobile including the same can be provided, which are easy to change in design.

[0035] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0036] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0037] FIG. 1 is a perspective view showing the overall appearance of a battery cell according to one embodiment of the present invention.

[0038] FIG. 2 is a side cross-sectional view showing a cross- section of a battery cell according to one embodiment of the present invention.

[0039] FIG. 3 is a perspective view showing a can lid according to one embodiment of the present invention.

[0040] FIG. 4 is a plan view showing a can lid according to one embodiment of the present invention.

[0041] Figure 5 is a side cross-sectional view showing a part of the AA' section of Figure 4.

[0042] Figure 6 is a plan view showing the can lids of a conventional battery cell.

[0043] FIG. 7 is a plan view showing examples of can lids according to one embodiment of the present invention.

[0044] FIG. 8 is a side cross-sectional view showing another part of the AA' section of FIG. 4.

[0045] FIG. 9 is a plan view showing a can lid according to another embodiment of the present invention.

[0046] FIG. 10 is a plan view showing each can lid according to an embodiment of the present invention and a variation of an embodiment.

[0047] FIG. 11 is a side cross-sectional view showing each can lid according to an embodiment of the present invention and a modified example of an embodiment.

[0048] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0049] FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention.

[0050] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, and should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0051] Therefore, it should be understood that the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the invention and do not represent all of the technical ideas of the invention, and that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0052] In this specification, unless otherwise specified, the X-axis and Y-axis directions may be left-right and front-back directions, or front-back and left-right directions, respectively, and the Z-axis direction orthogonal to the XY plane may be up-down direction (vertical direction).

[0053]

[0054] FIG. 1 is a perspective view showing the overall appearance of a battery cell according to one embodiment of the present invention, and FIG. 2 is a side cross-sectional view showing a cross- section of a battery cell according to one embodiment of the present invention.

[0055] Referring to FIGS. 1 and FIGS. 2, another battery cell (10) in one embodiment of the present invention may include an electrode assembly (100), a can housing (200), and a can lid (300).

[0056] The electrode assembly (100) may include an electrode (110) and a separator (120). The electrode (110) may include electrodes (110) of different polarities. Specifically, the electrode (110) may include a first electrode (110a) and a second electrode (110b). The first electrode (110a) may have a first polarity, and the second electrode (110b) may have a second polarity opposite to the first polarity. For example, the first polarity may be a positive electrode and the second polarity may be a negative electrode. The separator (120) may be interposed between electrodes (110) of different polarities. The separator (120) may be interposed between the first electrode (110a) and the second electrode (110b). The separator (120) may be an insulator.

[0057] The electrode assembly (100) may have a jelly-roll structure. That is, the electrode assembly (100) may be manufactured by winding a laminate formed by stacking at least once with a separator (120) interposed between a sheet-shaped first electrode (110a) and a second electrode (110b) around the central axis of a winding center hole (C). Any jelly-roll structure known in the art may be applied to the present invention without limitation.

[0058] The can housing (200) can accommodate the electrode assembly (100). The can housing (200) may be provided in a hollow cylindrical shape to accommodate the electrode assembly (100), for example. An opening (210) may be provided on one side of the can housing (200) (for example, the side in the +Z direction to the upper side). A closing part (220) may be formed on the other side of the can housing (200) (for example, the side in the -Z direction to the lower side).

[0059] The can lid (300) can be attached to the opening (210). The can lid (300) can be welded to the opening (210). The edge of the can lid (300) can be welded to the end of the can housing (200) forming the opening (210). The can lid (300) can cover the opening (210) of the can housing (200).

[0060]

[0061] Meanwhile, a battery cell (10) according to one embodiment of the present invention may further include an electrode terminal (400). The electrode terminal (400) may be electrically connected to an electrode assembly (100). For example, the electrode terminal (400) may be electrically connected to a first electrode (110a). The electrode terminal (400) may be disposed through a closed portion (220). The electrode terminal (400) may be formed such that at least a portion is exposed to the outside of the can housing (200) and another portion protrudes into the inside of the can housing (200). The electrode terminal (400) may be provided in the form of a rivet.

[0062]

[0063] FIG. 3 is a perspective view showing a can lid according to one embodiment of the present invention, FIG. 4 is a plan view showing a can lid according to one embodiment of the present invention, FIG. 5 is a side cross-sectional view showing a part of the AA' cross-section of FIG. 4, FIG. 6 is a plan view showing can lids of a conventional battery cell, and FIG. 7 is a plan view showing examples of a can lid according to one embodiment of the present invention.

[0064] Hereinafter, a battery cell (10) according to one embodiment of the present invention will be described in detail with reference to FIGS. 3 to 5.

[0065] The can lid (300) may be provided with an electrode coupling portion (310). The electrode coupling portion (310) may be coupled to the electrode assembly (100). The electrode coupling portion (310) may be welded to the electrode assembly (100).

[0066] The can lid (300) may be provided with a plurality of electrode coupling portions (310). The plurality of electrode coupling portions (310) may be spaced apart from each other. For example, the plurality of electrode coupling portions (310) may be spaced apart from each other along the circumferential direction.

[0067] Each of the multiple electrode coupling portions (310) may be provided with a welded coupling portion (WL). The welded coupling portion (WL) may be a part of the can lid (300) that is welded to the electrode assembly (100). The welded coupling portion (WL) may be welded to the second electrode (110b) of the electrode assembly (100). In this regard, a blank portion in which no active material is laminated is formed on the upper portion of the second electrode (110b), and the blank portion may be provided with, for example, a plurality of notched foil tabs, and the welded coupling portion (WL) may be welded to at least some of these plurality of foil tabs. The welded coupling portion (WL) may be formed on the bottom surface of the electrode coupling portion (310) facing the upper portion of the electrode assembly (100).

[0068] The welded joint (WL) can be configured such that the length of the first width (W1) is greater than or equal to the length of the second width (W2).

[0069] The first width (W1) may refer to any width following a direction perpendicular to the radial direction. For example, in the welded joint (WL), if the width following a direction perpendicular to the radial direction is formed uniformly along the radial direction, this width following a direction perpendicular to the radial direction may be referred to as the first width (W1). Additionally, for example, in the welded joint (WL), if the width following a direction perpendicular to the radial direction is not formed uniformly along the radial direction, the width following a direction perpendicular to the radial direction at the center point of the second width (W2) described later may be referred to as the first width (W1).

[0070] The second width (W2) may refer to a width along the radial direction. The second width (W2) may be approximately the width from the inner side to the outer side in the radial direction. If the can lid (300) is provided with a flat portion (350) and a bent notch portion (380) as described below, the second width (W2) may be formed to be slightly smaller than the radial length from the flat portion (350) to the bent notch portion (380).

[0071] The welded joint (WL) may be formed such that the length of the first width (W1) is equal to the length of the second width (W2), or the length of the first width (W1) may be formed to be greater than the length of the second width (W2).

[0072] In a battery cell (10) according to one embodiment of the present invention, since the can lid (300) has a plurality of electrode coupling portions (310), tilting with the electrode assembly (100) or unevenness in flatness with the electrode assembly (100) can be effectively prevented. Accordingly, the can lid (300) and the electrode assembly (100) can be uniformly and effectively adhered to each other, so welding defects such as over-welding or under-welding between the can lid (300) and the electrode assembly (100) can be significantly prevented.

[0073] In addition, in a battery cell (10) according to one embodiment of the present invention, the first width (W1) and the second width (W2) of the welded joint portion (WL) are formed as described above, so that the area of ​​the welded joint portion (WL), that is, the welding area between the can lid (300) and the electrode assembly (100), can be sufficiently wide. Accordingly, the welding strength between the can lid (300) and the electrode assembly (100) can be sufficiently high.

[0074] In this way, the battery cell (10) according to one embodiment of the present invention can significantly prevent welding defects between the can lid (300) and the electrode assembly (100), and can also sufficiently secure the welding area and welding strength, thereby significantly improving weldability.

[0075] As described above, if weldability is improved, the quality of the battery cell (10) can be improved, and the structural rigidity and stability of the battery cell (10) can also be improved.

[0076] In addition, in a battery cell (10) according to one embodiment of the present invention, the electrical resistance of the battery cell (10) can be formed low because the welding area between the can lid (300) and the electrode assembly (100) is sufficiently secured.

[0077] In addition, a battery cell (10) according to one embodiment of the present invention does not have a part such as a conventional beading part, so the space efficiency inside the battery cell (10) is improved and the energy density can be improved, and since a separate beading process or crimping process is not required, the productivity of the battery cell (10) can be improved.

[0078]

[0079] Additionally, with reference to FIGS. 6 and 7, a conventional battery cell (10', 10”) and a battery cell (10) according to one embodiment of the present invention are compared.

[0080] Referring to FIG. 6 (a), the electrode coupling portion (310') provided on the can lid (300') of a conventional battery cell (10') could be configured as a single unit rather than multiple units. In this case, while the welding area of ​​the can lid (300') could be sufficiently secured, it was difficult to prevent tilting or uneven flatness of the can lid (300'). Also, referring to FIG. 6 (b), when multiple electrode coupling portions (310") are provided on the can lid (300") of another conventional battery cell (10"), such that the length of the first width (W1) is shorter than the length of the second width (W2), while tilting or uneven flatness of the can lid (300") can be effectively resolved, there was a disadvantage that the welding area could not be sufficiently secured.

[0081] FIG. 7 (a) illustrates a can lid (300) according to one embodiment of the present invention, and FIG. 7 (b) illustrates a can lid (300) in which the first width (W1) is further increased compared to the case of FIG. 7 (a). The battery cell (10) according to one embodiment of the present invention as illustrated in FIG. 7 can effectively resolve tilting or unevenness of flatness of the can lid (300) compared to the aforementioned conventional battery cell (10', 10”), while simultaneously ensuring a sufficient welding area.

[0082]

[0083] Referring to FIGS. 3 to 5, the welded joint (WL) can be formed over the entire area of ​​the electrode joint (310). Accordingly, when viewed from the upper and lower directions, the shape of the welded joint (WL) and the shape of the electrode joint (310) can match each other. The welded joint (WL) can be formed over the entire area of ​​the bottom surface of the electrode joint (310), for example.

[0084] When the weld joint (WL) is formed in this way, the welding area between the can lid (300) and the electrode assembly (100) can be maximized.

[0085]

[0086] The welded joint (WL) can be provided in a flat shape. The bottom surface of the electrode joint (310) where the welded joint (WL) is formed can be provided in a flat shape.

[0087] When the weld joint (WL) is formed in this way, the flatness between the can lid (300) and the electrode assembly (100) can be formed more uniformly, and the can lid (300) can be more closely attached to the electrode assembly (100), thereby further improving the weldability of the battery cell (10).

[0088]

[0089] Referring to FIGS. 3 and FIGS. 4, the electrode coupling portion (310) may be provided in three parts.

[0090] In this case, the three electrode coupling parts (310) can easily form a single plane, so tilting or unevenness in flatness between the can lid (300) and the electrode assembly (100) can be significantly prevented.

[0091]

[0092] A plurality of electrode coupling portions (310) may be formed and arranged radially and rotationally symmetrically. Each electrode coupling portion (310) may be formed with the same shape as one another and arranged to be at equal angles to one another with respect to the center of the can lid (300). For example, three electrode coupling portions (310) of the same shape may be arranged on the can lid (300) at equal angles of 120 degrees.

[0093] In this way, when a plurality of electrode coupling parts (310) are provided symmetrically, tilting or uneven flatness between the can lid (300) and the electrode assembly (100) can be significantly prevented.

[0094]

[0095] FIG. 8 is a side cross-sectional view showing another part of the AA' section of FIG. 4.

[0096] Referring to FIGS. 3, FIGS. 4 and FIGS. 8, a can lid (300) according to one embodiment of the present invention may further include a plurality of spaced portions (320).

[0097] The separation portion (320) can be separated from the electrode assembly (100). The bottom surface of the separation portion (320) and the top surface of the electrode assembly (100) can be separated so as to face each other.

[0098] A spacing portion (320) may be positioned between any two adjacent electrode coupling portions (310). A spacing portion (320) may be provided between each of the two electrode coupling portions (310). Multiple spacing portions (320) may be formed and arranged rotationally symmetrically.

[0099] When viewed from the upper side or the +Z direction side, the electrode coupling part (310) may be formed in a negative shape, and the separation part (320) may be formed in a positive shape.

[0100] If the can lid (300) further comprises a separation portion (320) as described above, any two adjacent electrode coupling portions (310) can be clearly separated from each other. Additionally, a gap can be secured between the separation portion (320) and the electrode assembly (100), so that when the internal pressure inside the battery cell (10) increases due to thermal events, the increase in internal pressure can be effectively mitigated.

[0101]

[0102] When viewed from the central axis direction (e.g., Z-axis direction) of the winding center hole (C), the total area of ​​the welded joint (WL) can be formed to be larger than the total area of ​​the gap (320).

[0103] Here, the total area of ​​the welded joint (WL) can be understood as the sum of the areas of each of the plurality of welded joints (WL), and the total area of ​​the separated portion (320) can be understood as the sum of the areas of each of the plurality of separated portions (320).

[0104] When the can lid (300) is configured as described above, a void space can be formed inside the battery cell (10) to alleviate the increase in internal pressure, while at the same time, a wider welding area can be secured between the can lid (300) and the electrode assembly (100).

[0105]

[0106] Meanwhile, the separation portion (320) may be composed of a picking portion (P). The picking portion (P) may be an area that can be grasped by a picking device. In this case, foreign substances such as foreign matter can be prevented from entering the electrode coupling portion (310) from the picking device during the picking operation of the can lid (300), and the can lid (300) can be stably grasped and transported during the assembly process of the battery cell (10).

[0107]

[0108] Referring to FIGS. 3 to 5, the can lid (300) may further include an injection port (330) and a flat portion (350).

[0109] The injection port (330) can be opened toward the interior of the can housing (200). Electrolyte can be injected into the interior of the can housing (200) through the injection port (330). The shape and structure of the injection port (330) are not limited to the drawings and can be provided in various ways.

[0110] A plug (340) may be connected to the injection port (330). The plug (340) may cover the injection port (330). When the plug (340) is connected to the injection port (330), the injection port (330) may be closed. The plug (340) may be connected to the injection port (330), for example, by fitting. The plug (340) may be connected to the injection port (330), for example, by welding. Various methods may be applied to the connection method between the injection port (330) and the plug (340). The shape and structure of the plug (340) are not limited to the drawings and may be provided in various ways.

[0111] The flat portion (350) may surround the injection port (330). The flat portion (350) may surround the injection port (330) approximately along the circumferential direction. The flat portion (350) may be provided with a shape in which at least a portion is flat.

[0112] The flat portion (350) may be spaced apart from the electrode assembly (100). A void space may be formed between the flat portion (350) and the electrode assembly (100), and the void space may be in communication with the void space formed between the spaced portion (320) and the electrode assembly (100).

[0113] When the can lid (300) is configured as described above, the electrolyte can be easily injected into the battery cell (10) through the injection port (330). In addition, by means of the flat portion (350) spaced apart from the electrode assembly (100), damage to the electrode assembly (100) can be prevented when the plug (340) is joined to the injection port (330) by welding or the like. Furthermore, due to the empty space formed between the flat portion (350) and the electrode assembly (100), more effective internal pressure relief can be achieved.

[0114]

[0115] Meanwhile, the plug (340) may be provided with a protrusion (341) and an extension (342). The protrusion (341) may protrude vertically toward the inside of the can housing (200), and the extension (342) may extend horizontally from the protrusion (341). The can lid (300) may further be provided with a seating portion (331). The seating portion (331) may be a portion on which the extension (342) is seated. The upper surface of the seating portion (331) may be formed by being recessed toward the inside of the can housing (200) so as to be formed at a lower height than the upper surface of the flat portion (350).

[0116]

[0117] FIG. 9 is a plan view showing a can lid according to another embodiment of the present invention.

[0118] Hereinafter, with reference to FIG. 9, a battery cell (10) according to another embodiment of the present invention will be described in detail. The can lid (300) of the battery cell (10) according to another embodiment of the present invention may further include at least one of a first extension part (311) and a second extension part (312).

[0119] As previously explained, the can lid (300) may further be provided with a flat portion (350), and the flat portion (350) may be provided with a folded portion (351). The folded portion (351) may be formed by being sunken inward from the flat portion (350) toward the injection port (330).

[0120] The electrode coupling portion (310) of the can lid (300) may further be provided with a first extension portion (311). The first extension portion (311) may be formed to extend toward the bend portion (351). The first extension portion (311) may extend toward the injection port (330) by an amount equal to the indentation of the bend portion (351).

[0121] A welded joint (WL) may also be formed in the first extension portion (311). Therefore, if the electrode joint portion (310) further includes the first extension portion (311) as described above, the welding area between the can lid (300) and the electrode assembly (100) can be further expanded.

[0122] In addition, in this case, the welding length (LFW, Lid Foil tab Welding) between the electrode coupling part (310) and the electrode assembly (100) (which can be formed parallel to the radial direction) is increased, so that the internal resistance of the battery cell (10) can be reduced more effectively.

[0123]

[0124] The electrode coupling portion (310) of the can lid (300) may further include a second extension portion (312). The second extension portion (312) may be formed by extending in a circumferential direction.

[0125] The second extension (312) may be provided at a location adjacent to the center side or flat portion (350) of the can lid (300).

[0126] A welded joint (WL) may also be formed in the second extension (312). Therefore, if the electrode joint (310) further includes the second extension (312) as described above, the welding area between the can lid (300) and the electrode assembly (100) can be further expanded.

[0127]

[0128] Referring to FIGS. 3 to 5, a can lid (300) according to one embodiment of the present invention may further include a plurality of bridges (360).

[0129] The bridge (360) may be extended radially. The bridge (360) may be extended radially from the flat section (350). The bridge (360) may be extended from the flat section (350) toward the separated section (320).

[0130] Each of the multiple bridges (360) may be positioned between any two adjacent electrode coupling portions (310). The multiple bridges (360) may be formed and positioned radially and rotationally symmetrically.

[0131] If the can lid (300) further includes a bridge (360) as described above, two adjacent electrode coupling parts (310) can be more clearly separated and spaced apart, and the structural rigidity of the can lid (300) can be increased.

[0132] Meanwhile, the bridge (360) may be spaced apart from the electrode assembly (100) to form a void space between them. In this case, the void space between the bridge (360) and the electrode assembly (100) may be connected to the void space between the spaced-out section (320) and the electrode assembly (100) and the void space between the flat section (350) and the electrode assembly (100), respectively. The height of the upper surface of the bridge (360) may be lower than the height of the upper surface of the spaced-out section (320) and the upper surface of the flat section (350), but higher than the upper surface of the electrode coupling section (310).

[0133]

[0134] A can lid (300) according to one embodiment of the present invention may further comprise an edge portion (370). The edge portion (370) may be formed on the edge of the can lid (300) so as to be coupled to the can housing (200). The edge portion (370) may be coupled to the end of the opening portion (210) of the can housing (200) in a snap-fit ​​manner.

[0135] The edge portion (370) can be configured to be deformable in a direction parallel to the radial direction. In this case, the can lid (300) can be easily and strongly fitted to the end of the opening (210) of the can housing (200).

[0136] In addition, if the can lid (300) further comprises an edge portion (370) as described above, when the can lid (300) is coupled to the can housing (200), the tilting of the can lid (300) is adjustable, so that the close contact between the can lid (300) and the electrode assembly (100) can be carried out securely and easily.

[0137]

[0138] FIG. 10 is a plan view showing each can lid according to an embodiment of the present invention and a modified example of the embodiment, and FIG. 11 is a side cross-sectional view showing each can lid according to an embodiment of the present invention and a modified example of the embodiment.

[0139] Hereinafter, with reference to FIGS. 3 to 5, FIGS. 10 and FIGS. 11, particularly FIGS. 10 and FIGS. 11, a battery cell (10) according to one embodiment of the present invention will be described in more detail.

[0140] A can lid (300) of a battery cell (10) according to one embodiment of the present invention may further have a vent notch portion (380).

[0141] Referring to FIGS. 3 to 5, the vent notch portion (380) may be formed by notching between the edge of the can lid (300) and the electrode coupling portion (310). The vent notch portion (380) may be configured to break due to the internal pressure of the high-temperature venting gas when a thermal event occurs in the battery cell (10), so that the venting gas can be discharged from the battery cell (10) to the outside. Accordingly, when the vent notch portion (380) is provided on the can lid (300), the venting gas can be easily discharged from the battery cell (10). This vent notch portion (380) may be formed by notching along the circumferential direction on the inner side of the edge (for example, the inner side of the edge portion (370).

[0142] FIG. 10 (a) shows a can lid (300) with a radius of R-1, a first width (W1-1) following a direction perpendicular to the radial direction in the welded joint (WL) provided in the electrode joint (310) formed larger than a second width (W2-1) following the radial direction, and a bent notch (380) with a radius of r-1. FIG. 11 (a) shows a side cross-sectional view revealing the electrode joint (310) of the can lid (300) of FIG. 10 (a).

[0143] FIG. 10 (b) shows that the radius of the can lid (300) is R-2, which is the same as R-1, and the first-2 width (W1-2) following the direction perpendicular to the radial direction in the welded joint (WL) provided in the electrode joint (310) is formed larger than the second-2 width (W2-2) following the radial direction, and the radius of the bent notch (380) is formed as r-2. FIG. 11 (b) shows a side cross-sectional view revealing the electrode joint (310) of the can lid (300) of FIG. 10 (b).

[0144] r-2 is smaller than r-1, the 1-2 width (W1-2) is larger than the 1-1 width (W1-1), and the 2-2 width (W2-2) may be smaller than the 2-1 width (W2-1).

[0145] In one embodiment of the present invention, the can lid (300) may have the diameter of the vent notch portion (380) formed relatively large as in FIG. 10 (a) and FIG. 11 (a), or the diameter of the vent notch portion (380) may be formed relatively small as in FIG. 10 (b) and FIG. 11 (b).

[0146] And, even when the diameter of the bent notch portion (380) is formed to be relatively small as in FIG. 10 (b) and FIG. 11 (b), the weld joint portion (WL) is configured to have a first-2 width (W1-2) and a second-2 width (W2-2), so that the welding area between the can lid (300) and the electrode assembly (100) can still be sufficiently secured.

[0147] Accordingly, the battery cell (10) according to one embodiment of the present invention can have the diameter of the bent notch portion (380) varied while maintaining a sufficient welding area between the can lid (300) and the electrode assembly (100), so that design changes of the battery cell (10) or the battery pack (30) described later can be easily made.

[0148]

[0149] FIG. 12 is a drawing showing a battery pack according to one embodiment of the present invention.

[0150] Referring to FIG. 12, the battery pack (30) according to the present invention may include at least one battery cell (10) according to the present invention. The battery pack (30) may include a pack case (20) that accommodates at least one battery cell (10).

[0151] In the drawing, for the convenience of drawing, components such as busbars, cooling units, and external terminals for electrical connection of the battery cells (10) have been omitted. The structure of a plurality of battery cells (10) for manufacturing the battery pack (30) has been described above as an example.

[0152] Meanwhile, the battery pack (30) according to the present invention may further include various devices for controlling the charging and discharging of battery cells (10), such as a Battery Management System (BMS), a current sensor, a fuse, etc., although not shown.

[0153]

[0154] FIG. 13 is a drawing showing an automobile according to one embodiment of the present invention.

[0155] Referring to FIG. 13, a battery pack (30) according to one embodiment of the present invention may be applied to a vehicle (40), such as an electric vehicle or a hybrid vehicle. That is, the vehicle (40) according to the present invention may include a battery pack (30) according to the present invention. The battery pack (30) may be installed in a vehicle body frame or trunk space under the vehicle seat. In addition, the vehicle (40) according to the present invention may include various other components included in the vehicle (40) in addition to the battery pack (30). For example, the vehicle (40) according to one embodiment of the present invention may include, in addition to the battery pack (30) according to the present invention, a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc.

[0156] In addition, it goes without saying that the battery pack (30) according to the present invention may also be provided in other devices, mechanisms, and facilities, such as an energy storage system using a secondary battery, in addition to a vehicle (40).

[0157]

[0158] In this specification, terms indicating directions such as up, down, left, right, front, and back have been used; however, these terms are used merely for convenience of explanation, and it is obvious to those skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0159] As described above, although the present invention has been explained by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0160] [Explanation of the symbol]

[0161] 10: Battery cell

[0162] 20 : Pack case

[0163] 30: Battery pack

[0164] 40 : Car

[0165] 100 : Electrode assembly

[0166] 110 : Electrode

[0167] 110a: First electrode

[0168] 110b : Second electrode

[0169] 120 : Separator

[0170] 200 : Can housing

[0171] 210 : Opening

[0172] 220 : Closure

[0173] 300 : Can lid

[0174] 310: Electrode coupling part

[0175] 311: First extension

[0176] 312 : 2nd extension

[0177] 320 : Separation

[0178] 330 : Injection port

[0179] 331 : Seating part

[0180] 340 : Plug

[0181] 341 : Protrusion

[0182] 342 : Extension

[0183] 350 : Flat section

[0184] 351 : Bent section

[0185] 360: Bridge

[0186] 370 : Edge part

[0187] 380 : Vent notch

[0188] 400 : Electrode terminal

[0189] C : Winding center hole

[0190] WL: Welded joint

[0191] W1 : 1st width

[0192] W2 : 2nd width

Claims

1. An electrode assembly provided by being wound around the central axis of a winding center hole with a separator interposed between the first electrode and the second electrode; A can housing that accommodates the electrode assembly and has an opening formed at one end; and It comprises a plurality of electrode coupling parts coupled to the electrode assembly and spaced apart from each other, and includes a can lid coupled to one end of the can housing. Each of the above electrode coupling parts is, A battery cell characterized by having a welded joint portion configured such that the length of a first width along a direction perpendicular to the radial direction is greater than or equal to the length of a second width along the radial direction, as a portion for being welded to the electrode assembly.

2. In Paragraph 1, The above welded joint is, A battery cell characterized by being formed over the entire area of ​​the electrode coupling portion.

3. In Paragraph 1, The above welded joint is, A battery cell characterized by being provided in a flat shape.

4. In Paragraph 1, The above electrode coupling part is, A battery cell characterized by being provided with three.

5. In Paragraph 1, A plurality of the above electrode coupling parts, A battery cell characterized by being formed and arranged radially and rotationally symmetrically.

6. In Paragraph 1, The above can lid is, A battery cell characterized by further comprising a plurality of spacing portions disposed between any two adjacent electrode coupling portions and spaced apart from the electrode assembly.

7. In Paragraph 6, A battery cell characterized in that, when viewed from the direction of the central axis of the winding center hole, the total area of ​​the welded joint is formed to be larger than the total area of ​​the spaced-out portion.

8. In Paragraph 1, The above can lid is, An injection port that opens toward the interior of the can housing; and A battery cell characterized by further comprising a flat portion surrounding the above-mentioned injection port and spaced apart from the above-mentioned electrode assembly.

9. In Paragraph 8, The above flat section is, It is provided with a bent portion formed by being sunken toward the above injection port, The above electrode coupling part is, A battery cell characterized by further comprising a first extension portion extended toward the above-mentioned bend portion.

10. In Paragraph 1, The above electrode coupling part is, A battery cell characterized by further comprising a second extension portion extended in the circumferential direction.

11. In Paragraph 1, The above can lid is, A battery cell characterized by further comprising a plurality of bridges that extend radially and are formed to partition any two adjacent electrode coupling portions.

12. In Paragraph 1, The above can lid is, It further comprises an edge portion formed at the edge so as to be coupled to the above-mentioned can housing, and The above edge portion is, A battery cell characterized by being configured to be deformable in a direction parallel to the radial direction.

13. In Paragraph 1, The above can lid is, A battery cell characterized by further comprising a bent notch portion formed by notching between the edge and the electrode coupling portion.

14. A battery pack characterized by including at least one battery cell according to any one of claims 1 to 13.

15. An automobile characterized by including at least one battery pack according to paragraph 14.

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