Can lid, battery cell, battery pack, and vehicle comprising same

Abstract

A battery cell according to the present invention may comprise an electrode assembly, a cell housing, and a can lid. The cell housing includes a sidewall portion, an opening at a first end of the cell housing in the axial direction, and a bottom portion at a second end of the cell housing in the axial direction. The cell housing may be configured to accommodate the electrode assembly. The can lid comprises a vent notch portion, an edge portion, and an electrode coupling portion. The can lid is disposed to cover the opening of the cell housing, the can lid includes a first surface spaced apart from the electrode assembly in the axial direction and a second surface facing the electrode assembly, and the vent notch portion is formed on the first surface of the can lid.

Description

Can lid, battery cell, battery pack, and automobile including the same

[0001] The present invention relates to a can lid, a battery cell, a battery pack, and an automobile including the same. This application is a priority application for Korean Patent Application No. 10-2024-0129269 filed on September 24, 2024, and all contents disclosed in the specification and drawings of said application are incorporated by reference into this application.

[0002] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, as they possess not only the primary advantage of drastically reducing the use of fossil fuels but also the advantage of generating no by-products from energy use.

[0003] Secondary 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. In this case, it is common practice to first construct a battery module containing at least one battery cell, and then use this at least one battery module to construct a battery pack by adding other components. Alternatively, recently, battery packs in the form of a Cell-to-Pack, in which multiple battery cells are directly housed within a pack housing or a similar structure without modularizing them, are also being manufactured.

[0004] There is increasing demand for metal can-type battery cells for application in automotive battery packs. The metal cans can be prismatic or cylindrical; cylindrical battery cells feature a structure that accommodates a jelly-roll type electrode assembly inside a cylindrical can, offering the advantage of being more robust against shock and temperature than pouch-type battery cells.

[0005] The process of manufacturing a battery cell using a cylindrical can may include the steps of manufacturing a can by deep drawing a metal sheet to form a circular bottom (closed surface) and a circular tubular side wall connected thereto, accommodating an electrode assembly inside the can, and then finishing the open end of the can by covering it with a can lid. Butt welding or beading and crimping methods may be used for the finishing process. Battery cells using butt welding are attracting attention because they have the advantage of being able to increase the internal capacity more significantly than battery cells using beading and crimping methods while maintaining the same external shape.

[0006] Meanwhile, battery cells can be exposed to various environments depending on their usage conditions, and preventing the risk of explosion is particularly required for user safety. Generally, high temperatures and high pressures within a battery cell, which can be caused by abnormal operating conditions such as internal short circuits, charging states exceeding permissible current or voltage, exposure to high temperatures, or impacts from drops, can lead to the explosion of the battery cell. Therefore, means to relieve high pressure, which is the direct cause of battery cell explosions, must be provided. If proper high-pressure relief measures are provided for battery cells constructed using butt welding, the safety of battery packs containing such cells will be further enhanced.

[0007] The present invention was devised in consideration of the aforementioned problems and has one objective of providing a can lid equipped with a high-pressure relief means.

[0008] Another objective of the present invention is to provide a battery cell comprising such a can lid.

[0009] Another objective of the present invention is to provide a battery pack comprising such battery cells and a vehicle comprising the same.

[0010] A battery cell according to the present invention may include an electrode assembly, a cell housing, and a can lid.

[0011] The cell housing comprises a side wall portion, an opening at a first end of the cell housing in the axial direction, and a bottom portion at a second end of the cell housing in the axial direction. The cell housing may be configured to accommodate the electrode assembly.

[0012] The can lid includes a vent notch portion, an edge portion, and an electrode coupling portion. The can lid is positioned to cover the opening of the cell housing, and the can lid includes a first surface spaced apart from the electrode assembly in the axial direction and a second surface facing the electrode assembly, and the vent notch portion is formed on the first surface of the can lid.

[0013] In another aspect, the bent notch portion is located radially between the electrode coupling portion and the edge portion.

[0014] In another aspect, the bent notch portion has a V-shaped cross section or a U-shaped cross section in the axial direction.

[0015] In another aspect, the bent notch portion defines a closed-loop shape along the first surface of the can lid.

[0016] In another aspect, the can lid comprises a first plating layer on the first surface, and the can lid comprises a second plating layer on the second surface.

[0017] In another aspect, the can lid comprises nickel-plated steel (NPS).

[0018] In another aspect, the edge portion of the can lid is joined to the side wall portion of the cell housing at the first end of the cell housing.

[0019] In another aspect, the electrode coupling portion of the can lid extends axially further into the interior of the cell housing than the edge portion of the can lid.

[0020] In another aspect, the electrode coupling portion of the can lid contacts the electrode assembly, and the edge portion of the can lid is spaced apart from the electrode assembly.

[0021] In another aspect, the can lid includes a plurality of electrode coupling portions, and each of the plurality of electrode coupling portions contacts the electrode assembly.

[0022] In another aspect, the plurality of electrode coupling parts are spaced apart from each other in the circumferential direction.

[0023] In another aspect, the can lid includes a plurality of bridges, and each of the plurality of bridges is located between adjacent electrode coupling portions in the circumferential direction.

[0024] In another aspect, the plurality of electrode coupling parts are arranged rotationally symmetrically with respect to the center of the can lid.

[0025] In another aspect, the can lid further includes an injection port in the center.

[0026] In another aspect, the can lid further includes a flat portion surrounding the injection port, and the flat portion is located radially between the injection port and the electrode coupling portion.

[0027] In another aspect, the electrode assembly comprises a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode.

[0028] In another aspect, the first electrode includes a first non-restricted portion, and the second electrode includes a second non-restricted portion, and the second non-restricted portion of the second electrode is directly connected to the electrode coupling portion of the can lid.

[0029] In another aspect, the bottom portion of the cell housing includes a through hole, and a terminal extends through the through hole of the bottom portion, and the terminal is electrically connected to the first non-existent portion of the first electrode.

[0030] A battery pack according to the present invention may include a battery cell according to the present invention.

[0031] An automobile according to the present invention may include a battery pack according to the present invention.

[0032] According to the present invention, a can lid is provided that includes a vent notch portion which serves as a means for relieving high pressure in a battery cell.

[0033] A battery cell including a can lid according to the present invention can relieve high pressure, which is the direct cause of battery cell explosion, by causing the vent notch portion to rupture when gas inside fills above a certain pressure.

[0034] The can lid of the present invention also has a stable and evenly formed flat surface with respect to the electrode assembly, so that the welding quality with respect to the electrode assembly can be improved.

[0035] The can lid of the present invention can also have various dimensions, such as welding flatness with the electrode assembly, welding length, and injection port diameter, optimized.

[0036] According to another aspect of the present invention, a battery cell using butt welding is provided, so that energy density can be improved compared to a battery cell using beading and crimping methods.

[0037] According to another aspect of the present invention, the joint between the can lid and the cell housing is simplified, and there is no need to use a current collector plate when electrically connecting the electrode assembly to the can lid, thereby reducing the number of parts and assembly steps, and further increasing the internal volume of the battery cell to further increase the energy density of the battery cell.

[0038] 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.

[0039] FIG. 1 is a schematic perspective view of a battery cell according to one embodiment of the present invention.

[0040] FIG. 2 is a side cross-sectional view of a battery cell according to one embodiment of the present invention.

[0041] FIG. 3 is a plan view showing a can lid according to one embodiment of the present invention.

[0042] FIG. 4a is a side cross-sectional view taken along the cutting line AA' of FIG. 3.

[0043] FIG. 4b is a side cross-sectional view showing an enlarged view of the area around the liquid injection port of a battery cell according to one embodiment of the present invention.

[0044] FIG. 5 is a side cross-sectional view of a battery cell according to another embodiment of the present invention.

[0045] FIG. 6 is a perspective view showing a can lid according to another embodiment of the present invention.

[0046] FIG. 7 is a plan view showing a can lid according to another embodiment of the present invention.

[0047] FIG. 8 is a side cross-sectional view taken along the cutting line AA' of FIG. 7.

[0048] FIG. 9 is a perspective view of a conventional can lid.

[0049] Figure 10 is a table showing a comparison of the vent pressure of a can lid according to the present invention and a conventional can lid.

[0050] FIG. 11 is a schematic perspective view of a battery pack according to an embodiment of the present invention.

[0051] FIG. 12 is a schematic diagram of a vehicle including a battery pack according to an embodiment of the present invention.

[0052] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.

[0053] Therefore, the embodiments described in this specification and the configurations illustrated in the drawings are merely the most preferred embodiments of the present invention and do not represent all of the technical ideas of the present invention; thus, it should be understood that various equivalents and modifications that can replace them may exist at the time of filing this application.

[0054] In addition, the present invention includes various embodiments. For each embodiment, redundant descriptions of substantially identical or similar configurations are omitted, and the focus is on the differences.

[0055] Meanwhile, although terms indicating directions such as up, down, left, right, front, and back may be used in the present invention, these terms are merely for the convenience of explanation to distinguish different relative directions, and it is obvious to those skilled in the art that they may vary depending on the position of the object or the position of the observer, and such terms should not be interpreted as being limited, for example, to a specific orientation with respect to the direction of gravity.

[0056] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of the electrode assembly (100) wound in a jelly-roll shape is referred to as the axial direction. The direction surrounding the winding axis is referred to as the circumferential direction or perimeter direction. The direction approaching or moving away from the winding axis is referred to as the radial direction.

[0057] FIG. 1 is a schematic perspective view of a battery cell according to one embodiment of the present invention, and FIG. 2 is a side cross-sectional view of a battery cell according to one embodiment of the present invention.

[0058] Referring to FIGS. 1 and 2, a battery cell (10) according to one embodiment of the present invention may include an electrode assembly (100), a cell housing (200), and a can lid (300).

[0059] The battery cell (10) may be a secondary battery configured to be rechargeable. For example, the battery cell (10) may be a cylindrical battery cell.

[0060] The electrode assembly (100) may comprise a first electrode and a second electrode and a separator interposed between them. The first electrode may have a first polarity, and the second electrode may have a second polarity opposite to the first polarity. For example, the first polarity may be positive and the second polarity may be negative. In the following description, the first electrode may be referred to as the positive electrode and the second electrode as the negative electrode. However, it should be understood that in any embodiment described herein, the polarities of the first electrode and the second electrode may be modified or reversed.

[0061] The first electrode and the second electrode and the separator interposed between them can be laminated to form a laminate. The laminate of the first electrode, the second electrode, and the separator of the electrode assembly (100) can be wound around the winding center hole (C) to form a jelly roll. Each electrode (the first electrode and the second electrode) may have a blank portion (112a, 112b) that does not contain an active material. The blank portion (112a, 112b) may be positioned along the longitudinal edge of each electrode prior to winding, thereby allowing the blank portion (112a, 112b) to be placed at the axial end of the electrode assembly (100) after winding. The blank portion (112a, 112b) may have a plurality of notched foil tabs. Further details regarding an electrode having a blank portion and a notched tab can be found in U.S. Patent Application No. 2023 / 0395950 (hereinafter “Incorporated ‘950”), the entire contents of which are incorporated herein by reference.

[0062] The electrode assembly (100) can be accommodated inside the cell housing (200). The cell housing (200) may include an opening (210) at a first end of the cell housing (200) in the axial direction. The electrode assembly (100) can be inserted through the opening (210) formed at the first end of the cell housing (200) and accommodated in the cell housing (200).

[0063] The cell housing (200) may be a can comprising a side wall portion (205), an opening (210) provided at a first axial end of the side wall portion (205), and a bottom portion (220) connected to a second axial end of the side wall portion (205). In other words, the can may include a bottom portion (220) and a side wall portion (205) connected to the bottom portion (220) and extending in the axial direction, and the side wall portion (205) that is not connected to the bottom portion (220) may define the opening (210) of the can.

[0064] The terminal (400) may be disposed on the bottom portion (220) of the cell housing (200). The center of the bottom portion (220) may include a through hole, and at least a portion of the terminal (400) may extend through the through hole. The terminal (400) may be fixed to the bottom portion (220) by interposing a terminal gasket (500) between the bottom portion (220) and the terminal (400). The terminal (400) may be connected to the first electrode of the electrode assembly (100) and may have a first polarity. The terminal (400) may have a rivet shape. The terminal (400) is electrically connected to the first non-removable portion (112a) of the first electrode.

[0065] The bottom portion (220) and the side wall portion (205) of the cell housing (200) can be manufactured by forming a metal sheet using a deep drawing process and trimming the leading edge of the side wall portion (205) with a punch while holding it with a blank holder. In one embodiment, the metal sheet may be a nickel-plated steel sheet. Of course, the material of the cell housing (200) is not limited to this. For example, the material of the cell housing (200) may be made of a conductive metal such as aluminum, steel, or stainless steel, but is not limited to this.

[0066] An insulator (700) is interposed between the positive current collector plate (600) and the bottom portion (220) of the cell housing (200) to electrically insulate the positive current collector plate (600) and the bottom portion (220). The positive current collector plate (600) and the terminal (400) can be joined by a method such as resistance welding, ultrasonic welding, or laser welding, and thereby the terminal (400) can be connected to the first electrode of the electrode assembly (100).

[0067] The can lid (300) can be coupled to the side wall portion (205) at the first end of the cell housing (200) in the axial direction. The can lid (300) can cover the opening (210). The can lid (300) can cover the electrode assembly (100). The can lid (300) can be forcibly fitted into the opening (210) and secured within the opening (210) by a press fit at least temporarily. Subsequently, the can lid (300) can be secured more permanently to the cell housing (200) by a method such as welding, as described below.

[0068] The can lid (300) can be electrically connected to the cell housing (200). In embodiments, the edge of the can lid (300) is joined to the side wall portion (205) at the first end of the cell housing (200) in the axial direction so that the cell housing (200) and the can lid (300) are electrically connected while the electrode assembly (100) is housed inside the cell housing (200).

[0069] The above joining can be achieved by welding, brazing, or soldering.

[0070] The can lid (300) may have a disc shape so as to cover the opening (210) of the cell housing (200). The can lid (300) may be pressed through the opening (210) of the cell housing (200).

[0071] The can lid (300) can be joined to the cell housing (200) using butt welding. In this respect, the battery cell (10) can have a larger internal capacity in the same external shape than a battery cell using beading and crimping methods. Thus, the energy density of the battery cell (10) can be increased.

[0072] The can lid (300) can be electrically connected to the cell housing (200). The can lid (300) can be connected to the second electrode of the electrode assembly (100). In this respect, the can lid (300) may have a second polarity, and the cell housing (200) electrically connected to the can lid (300) may also have a second polarity. In the embodiments, the bottom portion (220) of the cell housing (200) and the side wall portion (205) connected thereto may both have a second polarity.

[0073] In the embodiments, the cell housing (200) may have a positive terminal and a negative terminal positioned at the same end of the cell housing (200) in the axial direction. For example, the cell housing (200) may have a positive terminal and a negative terminal at a second end, i.e., the bottom, in the axial direction. Busbars connected to both the positive and negative terminals may all be positioned at the same end of the cell housing (200) in the axial direction. In these embodiments, since the positive and negative terminals of the battery cell (10) face the same direction in the axial direction, the electrical connection structure of a plurality of battery cells (10) can be simplified. Additionally, the battery cell (10) according to the present specification has a structure in which most of the bottom of the cell housing (200) can be used as a second polarity terminal, thus having the advantage of securing a sufficient area for a welding member for electrical connection.

[0074] In the embodiments, the battery cell (10) may be a cylindrical secondary battery, for example, having a form factor ratio (ratio of height to diameter) greater than approximately 0.4. For example, the diameter of the battery cell (10) may be 40 mm to 50 mm, and the height may be 60 mm to 130 mm. The form factor of the battery cell (10) may be, for example, 46110, 4875, 48110, 4880, or 4680.

[0075] FIG. 3 is a plan view showing a can lid according to one embodiment of the present invention, and FIG. 4a is a side cross-sectional view taken along the cutting line AA' of FIG. 3. FIG. 4b is a side cross-sectional view showing an enlarged portion around the liquid injection port of a battery cell according to one embodiment of the present invention.

[0076] Referring to FIGS. 3 and 4, a can lid (300) according to one embodiment of the present invention may include an injection port (H), a flat portion (320), an edge portion (370), and a plurality of electrode coupling portions (310).

[0077] The injection port (H) can be configured so that an electrolyte can be injected into the cell housing (200) through the injection port (H). The injection port (H) can be located approximately in the center of the can lid (300). For example, the central axis (MA) of the cell housing (200) can pass through the injection port (H).

[0078] The flat portion (320) may surround the injection port (H). The flat portion (320) may extend radially from the injection port (H) and may surround the injection port (H) in a circumferential direction. The flat portion (320) may have a shape that is at least partially flat. In some embodiments, the flat portion (320) may include one or more main faces that are substantially perpendicular to the central axis (MA) of the cell housing (200).

[0079] The edge portion (370) of the can lid (300) may include the edge of the can lid (300) configured to be coupled to the cell housing (200). The edge portion (370) may be coupled to the opening (210) of the first end of the cell housing (200) by a press-fit method. The edge portion (370) may be coupled to the cell housing (200) by butt welding after being press-fitted to the opening (210) of the first end of the cell housing (200). The cross-section of the edge portion (370) may be approximately U-shaped. The edge portion (370) of the can lid (300) may be spaced at least slightly apart from the electrode assembly (100) along the axial direction as shown in FIG. 4a.

[0080] As illustrated in FIG. 5, the edge portion (370) of the can lid (300) may include a butt surface (372), a curved surface (371a), and an inclined surface (371b) extending radially from the outer to the inner side. The curved surface (371a) may be located between the butt surface (372) and the inclined surface (371b). The butt surface (372) may be radially further from the central axis (MA) of the battery cell (10) than the curved surface (371a) and the inclined surface (371b). In one or more embodiments, the butt surface (372) may be formed along the periphery of the can lid (300). The butt surface (372), the curved surface (371a), and the inclined surface (371b) may form a roughly U-shaped curved portion.

[0081] In the radial direction, the outer edge of the can lid (300) may include a butt surface (372). The butt surface (372) may be extended in the axial direction so that its outer surface contacts the inner surface of the side wall (205). The curved surface (371a) has a downwardly convex cross-sectional shape that is connected to the lower end of the butt surface (372) of the can lid (300), that is, the axial inner end of the butt surface (372), and extends radially inward as it moves axially inward. The slope of the curved surface (371a) becomes gradually gentler as it moves away from the butt surface (372). Since the butt surface (372) extends parallel in the axial direction, the slope of the tangent of the outer surface of the curved surface (371a) may gradually decrease from 90 degrees as it moves away from the butt surface (372). The inclined surface (371b) continues from the curved surface (371a). The inclined surface (371b) extends axially outward as it moves radially inward, but the slope may be constant. The U-shaped edge of the can lid (300) may be configured so that the can lid (300) can be press-fitted into the opening (210) at the first end of the cell housing (200).

[0082] The curved surface (371a) and the inclined surface (371b) provide a shape that allows the edge of the can lid (300) to be elastically deformed radially inward. Accordingly, when the can lid (300) is pressed into the opening (210), the U-shape is compressed and then expanded so that the can lid (300) can be fitted into the opening (210) without causing deformation of other parts of the can lid (300). Accordingly, a radial contact force can be secured between the side wall (205) of the cell housing (200) and the butting surface (372) of the can lid (300). In other words, during the process of pressing the can lid (300) into the opening (210) of the cell housing (200), the butting surfaces (372) can be strongly butted without twisting.

[0083] The butt joint (372) may have a length of 0.7 mm or more in the axial direction.

[0084] The electrode coupling portion (310) of the can lid (300) can be coupled to the electrode assembly (100). In one or more embodiments, the electrode coupling portion (310) of the can lid (300) can be directly connected to the electrode assembly (100). The electrode coupling portion (310) can be welded to the electrode assembly (100). In one or more embodiments, the lower surface (the surface facing the electrode assembly (100)) of the electrode coupling portion (310) can be coupled face-to-face with the electrode assembly (100). The second non-electrode portion (112b) of the second electrode is directly connected to the electrode coupling portion (310) of the can lid (300). The lower surface of the electrode coupling portion (310) can be coupled to the second non-electrode portion (112b) of the electrode assembly (100). That is, the second blank portion (112b) formed along the upper axial end of the electrode assembly (100) may include a foil tab, and the foil tab may be folded radially (e.g., radially inward), and after folding, the upwardly oriented surface of the foil tab may come into contact with and be welded to the electrode coupling portion (310) (e.g., the lower surface of the electrode coupling portion (310)) of the can lid (300). This is similar to the method disclosed in the incorporated '950 public document.

[0085] The electrode coupling portion (310) may be located between the flat portion (320) and the edge portion (370) of the can lid (300). For example, the flat portion (320), the electrode coupling portion (310), and the edge portion (370) of the can lid (300) may be arranged sequentially along the radial direction. The can lid (300) includes a plurality of electrode coupling portions (310), and 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 in the circumferential direction.

[0086] Each of the plurality of electrode coupling portions (310) may be formed axially concave downward relative to the flat portion (320) and edge portion (370) of the can lid (300). Specifically, the electrode coupling portion (310) may be formed concave toward the electrode assembly (100). The lower surface of each of the plurality of electrode coupling portions (310) may be closer to the electrode assembly (100) than the remaining lower surface of the can lid (300). In this embodiment, when the electrode coupling portion (310) is coupled to the electrode assembly (100), the remaining portion of the can lid (300) may be at least slightly spaced apart from the electrode assembly (100).

[0087] A can lid (300) according to one embodiment of the present invention may include a plurality of electrode coupling portions (310) formed spaced apart from each other and formed in a concave shape, and each of the plurality of electrode coupling portions (310) may have a flat portion located substantially on the same plane. This may form a relatively flat surface that can be stably coupled to an electrode assembly (100). This configuration may improve the welding quality between the can lid (300) and the electrode assembly (100) according to an embodiment of the present invention.

[0088] The electrode coupling portion (310) may include a lower surface that extends radially and is perpendicular to the axial direction of the cell housing (200). The height of the lower surface of the electrode coupling portion (310) may be lower than the height of the lower portion of the curved surface (371a). For example, the electrode coupling portion (310) may protrude further axially into the cell housing (200) than the curved surface (371a). In the embodiments, the lower portion of the curved surface (371a) may be spaced axially from the electrode assembly (100) inside the cell housing (200), while the lower surface of the electrode coupling portion (310) may be in close contact with the electrode assembly (100). Accordingly, the bonding process between the electrode coupling portion (310) and the electrode assembly (100) can be performed smoothly.

[0089] Meanwhile, since the can lid (300) according to an embodiment of the present invention is coupled to the cell housing (200) to cover the opening (210) of the cell housing (200) and can be electrically connected to the electrode assembly (100) at the same time, there is no need to separately include a current collector plate, such as a negative electrode current collector plate. In one or more embodiments, the can lid (300) of the present invention may be an integrated can lid (300) capable of simultaneously performing the functions of a current collector plate and a can lid (300). In such embodiments, a current collector plate is not interposed between the can lid (300) and the electrode assembly (100). In some embodiments, the battery cell (10) may not include a negative electrode current collector plate.

[0090] The can lid (300) can be electrically connected to the cell housing (200). For example, the can lid (300) can be electrically connected to the cell housing (200) through the bonding portion (372) of the edge portion (370) of the can lid (300) and the bonding portion of the inner circumference of the side wall portion (205) of the cell housing (200). The can lid (300) can be laser welded to the cell housing (200), and the electrode coupling portion (310) of the can lid (300) can be laser welded to the second non-removable portion (112b) of the second electrode of the electrode assembly (100). Then, the can lid (300) can serve as a negative electrode collector plate.

[0091] The electrode coupling portion (310) may extend toward the flat portion (320) and the edge portion (370) of the can lid (300). Specifically, the electrode coupling portion (310) may extend radially inward toward the flat portion (320), and the electrode coupling portion (310) may extend radially outward toward the edge portion (370). In this case, the radial length (d) of the electrode coupling portion (310), which can affect the welding length (LFW, Lid Foil tab welding) between the electrode coupling portion (310) and the foil tab, may be secured to an extent that the internal resistance of the battery cell (10) can be reduced.

[0092] The can lid (300) may include a plurality of electrode coupling portions (310), which may be spaced apart in a circumferential direction with respect to the center of the can lid (300). In one or more embodiments, the can lid (300) may include three electrode coupling portions (310). When the can lid (300) includes three electrode coupling portions (310), the plurality of electrode coupling portions (310) can easily form a single plane, so a stable coupling with the electrode assembly (100) can be more easily secured. However, it should be understood that the can lid (300) may include an appropriate number of electrode coupling portions (310). For example, the can lid (300) may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more electrode coupling portions (310).

[0093] The electrode coupling portion (310) can be formed by a suitable manufacturing method, such as plastic processing, so that a predetermined portion of the metal sheet-shaped can lid (300) is indented downward in the axial direction. Each of the joining portions of the electrode coupling portion (310) and the electrode assembly (100) can be extended in the radial direction.

[0094] The inner surface of the side wall portion (205) of the cell housing (200) and the butting surface (372) of the can lid (300) can be butted together and joined.

[0095] A can lid (300) according to one embodiment of the present invention may further include at least one bridge (350). In some embodiments, the can lid (300) may include a plurality of bridges (350). For example, the can lid (300) may include 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more bridges (350). In some embodiments, the can lid (300) may include three bridges (350). Each bridge (350) may extend radially from a flat portion (320). In one or more embodiments, a bridge (350) may partition two adjacent electrode coupling portions (310). A bridge (350) may extend from a flat portion (320) toward an edge portion (370). Alternatively, the bridge (350) may extend from the flat section (320) toward the picking section (360) described later.

[0096] A plurality of electrode coupling portions (310) can be partitioned by a plurality of bridges (350) and spaced apart from each other. Additionally, the bridges (350) can improve the rigidity of the can lid (300).

[0097] In one or more embodiments, the upper surface of the bridge (350) may be higher than the upper surface of the electrode coupling portion (310) but lower than the upper surface of the flat portion (320). When the bridge (350) is formed in this way, the rigidity of the can lid (300) may be further improved.

[0098] A plurality of electrode coupling portions (310) may be formed and arranged symmetrically with respect to the center of the can lid (300). Each electrode coupling portion (310) may be formed with the same shape as one another and may be arranged to form equal angles with respect to the center of the can lid (300). In this way, when a plurality of electrode coupling portions (310) are formed and arranged symmetrically, a stable coupling between the can lid (300) and the electrode assembly (100) can be secured, and the electrical stability of the battery cell (10) can also be improved.

[0099] A can lid (300) according to one embodiment of the present invention may further include a plug coupling portion (340). The plug coupling portion (340) may surround the injection port (H) in a circumferential direction. The injection port (H) may be located in the center of the plug coupling portion (340). The plug coupling portion (340) may be formed so that a plug (330) can be inserted and seated therein. The plug (330) may be configured to seal the injection port (H) when inserted and seated in the plug coupling portion (340). The plug (330) may be formed by deep drawing a thin metal sheet with a thickness of 0.3 mm. If the metal sheet is too thin, it may be difficult to form and may lack rigidity. The total height of the plug (330) may be 1.5 mm to 1.7 mm.

[0100] The plug coupling portion (340) may be provided with an insertion portion (341) and a seating portion (342). A plug (330) may be inserted into the insertion portion (341). The insertion portion (341) of the plug coupling portion (340) may extend axially toward the inside of the cell housing (200). The plug (330) may have a protrusion (331) formed to be inserted into the insertion portion (341). The protrusion (331) may be coupled to the insertion portion (341) of the plug coupling portion (340) in a press-fit manner. The insertion portion (341) of the plug coupling portion (340) may be the outer edge of the injection port (H), and the injection port (H) may be sealed when the protrusion (331) of the plug (330) is inserted into the insertion portion (341) of the plug coupling portion (340).

[0101] A plug (330) may be seated in the seating portion (342). The plug (330) may be provided with an extension portion (332) to be seated in the seating portion (342). The extension portion (332) may be in a shape that extends radially from the insertion portion (341). The seating portion (342) of the plug coupling portion (340) may extend radially from the insertion portion (341) of the plug coupling portion (340). The seating portion (342) of the plug coupling portion (340) may be formed with a step so that the extension portion (332) of the plug (330) can be seated. The extension portion (332) of the plug (330) and the seating portion (342) of the plug coupling portion (340) of the can lid (300) may be welded together.

[0102] As described above, when the can lid (300) includes a plug coupling portion (340), the coupling between the plug (330) and the can lid (300) is improved, and the injection port (H) can be effectively sealed.

[0103] In one or more embodiments, the insertion portion (341) may protrude less axially into the cell housing (200) than the electrode coupling portion (310) of the can lid (300). Since the insertion portion (341) is formed slightly higher than the electrode coupling portion (310), a gap can be created between it and the electrode assembly (100). By preventing heat generated during plug (330) welding from being transferred to the separator of the electrode assembly (100), damage to the electrode assembly (100) can be prevented.

[0104] Referring to FIG. 4a, the length (b) of the seating portion (342) is the radial distance from the injection port (H) to the flat portion (320) of the can lid (300). The greater the length (b) of the seating portion (342) from the injection port (H) to the end of the flat portion (320), the better the weldability between the extension portion (332) of the plug (330) and the seating portion (342) can be improved. The length (b) can be designed to prevent welding defects of the plug (330) caused by the heat of vaporization of the electrolyte. In one or more embodiments, the length (b) may be 1 mm to 3 mm. For example, the length (b) may be 2 mm. In these embodiments, the outer diameter of the seating portion (342) may be 4 mm larger than the diameter of the injection port (H). The seating portion (342) may be formed, for example, by a forging method.

[0105] Referring again to FIG. 4a, the length (c) of the flat portion (320) is a length that extends radially from the plug coupling portion (340) to the electrode coupling portion (310). The length (c) of the flat portion (320) may be a length suitable for securing a flat surface of the electrode coupling portion (310). For example, the length (c) may be 3 mm or more. If the length (c) is less than 3 mm, it may be difficult to form the flat portion (320).

[0106] The injection port (H) may be shaped to have a tubular portion through piercing and burring, or it may be a hole pierced through the insertion portion (341).

[0107] FIG. 5 is a side cross-sectional view of a battery cell according to another embodiment of the present invention. Referring to FIG. 5, the injection port (H) is formed by piercing.

[0108] Referring to FIG. 4b, the can lid (300) can have the center of the winding center hole (C) and the center of the injection port (H) aligned with the center axis (MA) of the cell housing (200). Accordingly, the can lid (300) and the electrode assembly (100) can be arranged in a concentric structure with respect to each other.

[0109] When the can lid (300) is configured as described above, uniform injection of the electrolyte is possible when injecting the electrolyte through the injection port (H). Additionally, when the welding rod is inserted into the winding center hole (C) through the injection port (H), interference with the winding center hole (C) can be prevented, and the insertion can be performed easily and precisely.

[0110] In FIGS. 4 and 5, the injection port (H) may be a hole through which an electrolyte is injected and a hole through which a welding rod passes. For example, a current collector plate (e.g., a positive current collector plate (600)) and a rivet-shaped terminal (400) may be disposed on the opposite side of the injection port (H) in the battery cell (10), and a welding rod may pass through the injection port (H) and be inserted into the winding center hole (C) of the electrode assembly (100) to weld the current collector plate and the terminal (400).

[0111] Accordingly, it may be desirable for the diameter (a) of the injection port (H) to be larger than the diameter of the welding rod in order to avoid interference with the welding rod. Additionally, the diameter (a) of the injection port (H) may be formed smaller than the size (a') of the winding center hole (C) for stable injection of the electrolyte. If the diameter (a) of the injection port (H) is larger than the size (a') of the winding center hole (C), the separator in the winding center hole (C) of the electrode assembly (100) may unravel or come out when the electrolyte is injected at high pressure. Taking this into consideration, the diameter (a) of the injection port (H) may be 5mm to 5.5mm in the embodiments.

[0112] FIG. 6 is a perspective view showing a can lid according to another embodiment of the present invention, FIG. 7 is a plan view showing a can lid according to another embodiment of the present invention, and FIG. 8 is a side cross-sectional view taken along the cutting line AA' of FIG. 7.

[0113] Referring to FIGS. 6 to 8, another can lid (300) of another embodiment of the present invention has a folded portion (321) and an electrode coupling portion (310), and the electrode coupling portion (310) may include an extension portion (311).

[0114] It may be a depression formed axially along the circumference of the flat portion (320). For example, if the flat portion (320) of the can lid (300) is substantially circular, the fold portion (321) may be a depression formed axially along the substantially circular circumference of the flat portion (320) toward the injection port (H). The can lid (300) may include one or more fold portions (321). In some embodiments, the can lid (300) may have the same number of fold portions (321) and electrode coupling portions (310). The extension portion (311) may extend radially from the electrode coupling portion (310) toward the fold portion (321). The extension portion (311) may occupy at least a portion of the depression of the flat portion (320) formed by the fold portion (321). The extension portion (311) may be further extended toward the injection port (H) to the extent that the bend portion (321) is formed concavely. For example, the radial edge of the extension portion (311) toward the bend portion (321) may have substantially the same shape as the radial edge of the bend portion (321) toward the extension portion (311). In one or more embodiments, the bend portion (321) may be directly connected to the extension portion (311).

[0115] In this embodiment, when the flat portion (320) and the electrode coupling portion (310) each have a bent portion (321) and an extended portion (311), the radial length (d) of the electrode coupling portion (310) that affects the welding length (LFW) between the electrode coupling portion (310) and the electrode assembly (100) may be further increased. This may reduce the internal resistance of the battery cell (10). For example, if the can lid (300) does not have a bent portion (321) and an extended portion (311), the length (d) may be about 9 mm, and if the can lid (300) has a bent portion (321) and an extended portion (311), the length (d) may be longer to about 12 mm.

[0116] In this embodiment, the length (c) in the remaining part of the flat portion (320), excluding the bent portion (321), can be easily secured. Additionally, the length (a) and / or length (b) can be easily secured. Furthermore, the rigidity of the can lid (300) can be further reinforced. Additionally, as the internal resistance of the battery cell (10) can be reduced, the width (circumferential direction) of the electrode coupling portion (310) can be reduced, thereby easily securing the picking portion (360) described later.

[0117] As described above, when lengths (a), (b), (c) and (d) are designed, various dimensions of the can lid (300), including the weld flatness and weld length of the can lid (300) and the diameter (a) of the injection port (H), can be optimized.

[0118] By using the above-described can lid (300), the joint between the can lid (300) and the cell housing (200) is simplified, and there is no need to use a current collector plate when electrically connecting the electrode assembly (100) to the cell housing (200). This can reduce the number of parts and assembly steps required for manufacturing the battery cell (10). This can also increase the internal volume of the battery cell (10) for the electrode assembly (100), thereby increasing the energy density of the battery cell (10).

[0119] Referring to FIGS. 2 to 8, a can lid (300) according to embodiments of the present invention further includes a bent notch portion (380).

[0120] A vent notch (380) may be included on the surface of the can lid (300) facing in the opposite direction to the electrode assembly (100). In one or more embodiments, the can lid (300) may include a first surface facing in the opposite direction to the electrode assembly (100) in the axial direction and a second surface facing in the axial direction to the electrode assembly (100). The vent notch (380) may be located on the first surface of the can lid (300). For example, the vent notch (380) may be located on the outer surface of the can lid (300) facing in the opposite direction to the inside of the cell housing (200).

[0121] In one or more embodiments, the vent notch (380) may be formed on the upper part of the can lid (300). The vent notch (380) may be formed on the upper surface of the can lid (300).

[0122] The vent notch (380) may be configured to rupture when the internal pressure of the battery cell (10) exceeds the maximum internal pressure. The vent notch (380) may be configured to discharge 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 through the ruptured vent notch (380). The vent notch (380) may include a notch extending along the circumferential direction on the inner side of the edge portion (370) of the can lid (300).

[0123] The rupture pressure of the cell housing (200) can be controlled by controlling the depth and width of the vent notch portion (380). For example, the vent notch portion (380) allows the pressure inside the cell housing (200) to be 15 kgf / cm² 2 Up to 35 kgf / cm² 2It can be set to rupture when within the range. The vent notch (380) can be formed by forming a notch or a depression to partially reduce the thickness of the can lid (300). The vent notch (380) may have a thickness gradient. A thickness gradient means that when checking the cross-section of the vent notch (380), it is formed at a certain angle relative to a predetermined horizontal plane. This vent notch (380) ruptures when the pressure inside the cell housing (200) rises above a predetermined pressure, allowing at least a portion of the internal gas to be discharged to the outside of the battery cell (10).

[0124] In one or more embodiments, the thickness of the can lid (300) may be 0.4 mm to 0.8 mm. For example, the thickness of the can lid (300) may be 0.6 mm.

[0125] In one or more embodiments, the battery cell (10) may be a 4680 battery cell. In the case of a 4680 battery cell, taking into account the thickness of the side wall portion (205), if the unilateral press fit amount is designed to be about 110 μm, the diameter of the can lid (300) may be 45.2 mm.

[0126] In the axial cross-section of the can lid (300), the bent notch portion (380) may have a V-shape or a U-shape.

[0127] On the upper surface of the can lid (300), the vent notch portion (380) may have a closed-loop shape. In this embodiment, the vent notch portion (380) may extend continuously along the upper surface of the can lid (300) in a circumferential direction, surrounding at least a portion of the can lid (300).

[0128] The vent notch (380) may rupture when the pressure inside the cell housing (200) exceeds a critical threshold. The vent notch (380) may form a continuous or discontinuous circular pattern, a straight pattern, or other pattern on the surface of the can lid (300). For example, the vent notch (380) may be formed in the shape of a roughly circular ring with a certain width. This circular ring-shaped vent notch (380) may have the same center as the center of the can lid (300).

[0129] The vent notch portion (380) may be formed by notching only one side of the can lid (300) (unidirectionally). For example, the surface of the can lid (300) facing the inside of the cell housing (200) may not have a notch formed, and the surface of the can lid (300) facing the opposite direction from the inside of the cell housing (200) may have a notch formed.

[0130] When a vent notch (380) is formed in the can lid (300), venting gas can be easily discharged from the battery cell (10). Since the vent notch (380) is provided in the can lid (300) and does not occupy a separate space inside the battery cell (10), the energy density of the battery cell (10) can be improved.

[0131] The can lid (300) may be a metal sheet having plating layers on both sides. The can lid (300) may include a first plating layer on a first surface and a second plating layer on a second surface.

[0132] For example, the can lid (300) may be a nickel-plated steel sheet (NPS).

[0133] In an embodiment where the can lid (300) includes NPS, the nickel plating may peel off during notching. Therefore, if the vent notch portion (380) is formed only on the upper part of the can lid (300), there is no risk of foreign matter entering toward the electrode assembly (100).

[0134] If the steel at the bottom of the nickel plating is exposed through notching, there may be corrosion problems such as the formation of fluoride when in contact with the electrolyte. As in the embodiment of the present invention, if the vent notch portion (380) is formed on the can lid (300) side that does not face the electrode assembly (100), there is no concern that the electrolyte will come into contact with the vent notch portion (380), so there is no problem with corrosion.

[0135] If there is a notch on the side facing the electrode assembly (100), there is a concern that damage to the notched portion may occur due to the expansion and contraction of the electrode assembly (100) during the activation and charging / discharging process. As in the embodiment of the present invention, if the vent notch portion (380) is formed on the side not facing the electrode assembly (100), the problem of damage to the vent notch portion (380) due to the expansion and contraction of the electrode assembly (100) is fundamentally prevented.

[0136] By forming the vent notch portion (380) on the upper surface of the can lid (300) in this manner, corrosion of the can lid (300) or contact with the electrode assembly (100) is avoided. As a result, normal operation of the battery cell (10) and maintenance of the shape of the vent notch portion (380) are possible.

[0137] The vent notch (380) may be formed at a location further away from the injection port (H) than the electrode coupling portion (310) in the radial direction. For example, the vent notch (380) may be formed between the electrode coupling portion (310) and the edge portion (370) of the can lid (300).

[0138] In one or more embodiments, the electrode coupling portion (310) may be formed axially concave compared to the flat portion (320) and edge portion (370) of the can lid (300). In these embodiments, the vent notch portion (380) may be located in a portion of the can lid (300) that is not formed concavely, either equally or more than the electrode coupling portion (310). In these embodiments, the portion of the can lid (300) including the vent notch portion (380) may be spaced axially apart from the electrode assembly (100). Referring to FIG. 5, a space (S) is formed between the vent notch portion (380) and the electrode assembly (100) so that gas can be collected in this space (S). When the gas pressure in this portion exceeds a predetermined value, the vent notch portion (380) may rupture and the gas may be discharged to an external area of ​​the battery cell (10). If the vent notch (380) is located in the part of the can lid (300) that is concave toward the electrode assembly (100), it is difficult to collect gas between the vent notch (380) of the can lid (300) and the electrode assembly (100) as described above, making it difficult to rupture the vent notch (380).

[0139] In one or more embodiments, the can lid (300) may further include a support surface (390) that provides a flat surface between the inclined surface (371b) of the edge portion (370) and the electrode coupling portion (310). A bent notch portion (380) may be formed on this support surface (390). The electrode coupling portion (310) is connected to the radially inner side of the support surface (390), and the electrode coupling portion (310) may be formed concavely toward the inside of the cell housing (200) relative to the support surface (390).

[0140] The support surface (390) may extend horizontally in the radial direction. The support surface (390) may be located radially further inward toward the center axis (MA) of the cell housing (200) than the curved surface (371a) of the can lid (300). The support surface (390) is connected to the radially inner end of the inclined surface (371b) and may extend radially horizontally from the connection portion toward the center axis (MA) of the cell housing (200). The support surface (390) includes a flat surface between the inclined surface (371b) and the electrode coupling portion (310). In one or more embodiments, the surface of the support surface (390) may have a flat ring shape.

[0141] The vent notch portion (380) may not be deformed by the force applied to the can lid (300) when the can lid (300) is pressed into the cell housing (200). The vent notch portion (380) may be damaged when the internal pressure of the battery cell (10) increases rapidly due to a short circuit or the like occurring inside the cell housing (200), thereby separating the electrode coupling portion (310) of the can lid (300) from the abutting surface (372) of the can lid (300). Accordingly, the electrical connection between the electrode coupling portion (310) connected to the electrode assembly (100) and the cell housing (200) is severed, and the internal space of the cell housing (200) is opened to the external environment of the battery cell (10), thereby discharging the gas that caused the increase in internal pressure.

[0142] The axial upper surface of the support surface (390) may be positioned lower in the axial direction than the axial upper surface of the abutting surface (372). In this embodiment, there is a gap (G) between the upper surface of the abutting surface (372) and the upper surface of the support surface (390). Accordingly, when the battery cell (10) is placed on the floor, the vent notch portion (380) does not come into direct contact with the floor, thereby preventing the vent notch portion (380) from being unintentionally damaged or ruptured.

[0143] In one or more embodiments, the total height (h) of the can lid (300) may be 1.0 mm to 3.0 mm. If the total height (h) of the can lid (300) is less than 1.0 mm, the peripheral portion of the electrode coupling portion (310) may not be reliably separated from the electrode assembly (100). If the total height (h) of the can lid (300) exceeds 3.0 mm, the volume occupied by the can lid (300) increases, and the energy density of the battery cell (10) may decrease.

[0144] FIG. 9 is a perspective view of a conventional can lid. FIG. 10 is a table showing a comparison of the vent pressure of a can lid according to the present invention and a conventional can lid.

[0145] Referring to FIGS. 9 and FIGS. 10, the vent pressure of a battery cell (10) using a can lid (300) according to an embodiment of the present invention is lower than that of a conventional battery cell.

[0146] A battery cell using the conventional can lid (300) illustrated in FIG. 9 may include a separate current collector between the can lid (300) and the electrode assembly. The conventional can lid (300) illustrated in FIG. 9 may have a flat plate shape that is entirely flat without curvature along the periphery of the flat portion (320) where the electrode coupling portion (310) surrounds the injection port (H).

[0147] It was very difficult to ensure adequate flatness with respect to the electrode assembly in the conventional battery cell can lid (300). In other words, it was very difficult to ensure adequate adhesion with respect to the electrode assembly in the conventional can lid (300). Specifically, the electrode assembly may be incompletely flattened, such as when a number of foil tabs are formed to be finely partially curved rather than completely flattened. As shown in FIG. 9, the electrode coupling portion (310) of the conventional battery cell can lid (300) could be formed as a single continuous flat shape without curvature along the circumferential direction. Due to this single flat shape, the conventional can lid (300) was highly likely to form an unstable or inconsistent adhesion with the electrode assembly that was incompletely flattened as described above, making it very difficult to ensure adequate adhesion between the can lid (300) and the electrode assembly.

[0148] FIG. 10 shows a comparative experimental example of the vent pressure of a can lid (300) (integrated type) according to one embodiment of the present invention and a conventional can lid (300) (separated type) shown in FIG. 9. Here, vent pressure refers to the magnitude of the internal pressure of a battery cell at which the vent notch portion (380) begins to break.

[0149] According to FIG. 10, the notch thickness of the vent notch portion (380) of a can lid (300) (integrated type) according to one embodiment of the present invention and the thickness of the vent notch portion (380) of a conventional can lid (300) (separated type) are approximately similar, at 91 μm and 95 μm, respectively. However, the vent pressure of the can lid (300) (integrated type) according to one embodiment of the present invention is an average of 19.4 kgf / cm² 2 (Dispersion 2.05 kgf / cm² 2 This is the average vent pressure of a conventional can lid (300") (separable type), which is 28.7 kgf / cm². 2 (Dispersion 2.92 kgf / cm² 2It is lower than ). That is, the can lid (300) (integrated type) according to one embodiment of the present invention has the advantage of being able to secure a thickness of the vent notch portion (380) similar to that of a conventional can lid (300) (separated type), thereby ensuring moldability of the vent notch portion (380), while also being able to form a lower vent pressure. Forming a lower vent pressure means that safety can be secured to that extent.

[0150] Referring again to FIG. 3 or FIG. 7, the can lid (300) according to the present invention may further include a picking portion (360).

[0151] The picking portion (360) may be located between two adjacent electrode coupling portions (310) and edge portions (370). A picking area (361) may be formed in the picking portion (360). The picking area (361) may be configured to be grasped by a picking device. The diameter of the picking area (361) may be 2 mm to 6 mm. For example, the diameter of the picking area (361) may be about 4 mm.

[0152] When the can lid (300) according to the present invention is equipped with a picking portion (360), the picking equipment may not come into contact with the electrode coupling portion (310). Accordingly, foreign substances such as foreign matter may be prevented from entering the electrode coupling portion (310) from the picking equipment, and the can lid (300) may be stably gripped and transported during the assembly process of the battery cell (10).

[0153] FIG. 11 is a schematic perspective view of a battery pack according to an embodiment of the present invention. FIG. 12 is a schematic diagram of a vehicle including a battery pack according to an embodiment of the present invention.

[0154] The battery cell (10) described above can be accommodated in the housing (20) of the battery pack (30) as shown in FIG. 11. The battery pack (30) can be constructed using multiple battery modules, which are intermediate assembly forms that each contain multiple battery cells (10). Thus, the battery pack (30) can be constructed in a form in which multiple battery modules containing multiple battery cells are arranged, or it can be constructed by directly assembling multiple battery cells (10) without passing through battery modules, as shown in FIG. 11. Since the battery cell (10) itself has a large volume, there is no particular difficulty in implementing the battery pack (30) even without using an intermediate structure called a battery module. In addition, since the negative electrode of the battery cell (10) can be connected through the can lid (300), the internal resistance is low and the energy density is high. Furthermore, since a vent notch (380) is provided on the can lid (300) and does not occupy a separate space, the energy density can be further secured. Accordingly, the energy density of the battery pack (30) including the battery cell (10) can be improved.

[0155] In one or more embodiments, a plurality of battery cells (10) may be included in the battery pack (30). The battery cells (10) may be arranged in a predetermined number of rows, and both the positive terminal and the negative terminal of each battery cell (10) may be arranged facing the upper side of the battery pack (30). Thus, when electrically connecting the plurality of battery cells (10), both the positive and negative terminals can be connected in one direction, thereby simplifying the electrical connection structure. Through this, the number of battery cells (10) that can be mounted in the same space can be increased to improve energy density, and electrical wiring work can be performed easily. Therefore, space efficiency is good and the efficiency of electrical wiring can be improved, resulting in significant work improvement effects during the assembly process of the electric vehicle and during the assembly and maintenance of the battery pack (30). In addition, as previously described, each battery cell (10) may also have a higher energy density than conventional ones. A battery pack (30) with such increased energy density can store the same amount of energy while reducing the volume and weight of the battery pack (30).

[0156] Therefore, if a battery pack (30) with such battery cells (10) is installed in a vehicle such as a car (40) that uses electricity as an energy source as shown in FIG. 12, the vehicle's mileage relative to energy can be further increased.

[0157] The automobile (40) according to the present invention may include a battery pack (30). The automobile (40) may be a hybrid automobile or an electric automobile. The automobile (40) according to the present invention may further include various other components included in the automobile in addition to the battery pack (30). For example, the automobile (40) according to the present invention may further include a vehicle body, a motor, an ECU (electronic control unit), and other control devices in addition to the battery pack (30) according to the present invention.

[0158] In one or more embodiments, electrical wiring may be performed on the side where the bottom portion (220) or terminal (400) of the cell housing (200) is located, and electrical wiring may not be placed on the can lid (300) located on the opposite side. This can maximize the effect of the vent notch portion (380) formed on the can lid (300). Additionally, if a heat sink, cooling plate, or tray is located on the side of the can lid (300), purposes such as assembly and cooling can be effectively achieved regardless of the electrical wiring connection area.

[0159] Additionally, by assembling the vent notch portion (380) so that it is positioned downward, the gas emitted from inside the secondary battery is discharged downward. Typically, secondary batteries are mounted at a position lower than the occupants of a vehicle. Therefore, if gas is discharged upward from the secondary battery, it can cause harm to the occupants. On the other hand, the battery cell (10) of the present invention can effectively discharge high-pressure gas inside the secondary battery downward, in the opposite direction to the occupants. This reduces the possibility of vehicle occupants being harmed by the gas emitted from the secondary battery, and consequently improves the safety of the vehicle. Furthermore, the possibility of damage to the electrical wiring connection on the upper part of the battery cell due to the gas emitted from the secondary battery is also reduced.

[0160] As described above, although the present invention has been described with reference to preferred embodiments with reference to the accompanying drawings, it is evident to those skilled in the art that many diverse and obvious variations are possible from this description without departing from the scope of the invention. Accordingly, the scope of the invention should be interpreted by the claims described to include examples of such many variations.

[0161] [Explanation of the symbol]

[0162] 10: Battery cell 20: Housing

[0163] 30: Battery pack 40: Car

[0164] 100: Electrode assembly 112a, 112b: Uninhibited portion

[0165] 200: Cell housing 205: Sidewall

[0166] 210: Opening 220: Bottom

[0167] 300: Can lid 310: Electrode coupling part

[0168] 311: Extension section 320: Flat section

[0169] 321: Bending section 330: Plug

[0170] 331: Protrusion 332: Extension

[0171] 340: Plug connection part 341: Insertion part

[0172] 342: Seating section 350: Bridge

[0173] 360: Picking Section 361: Picking Area

[0174] 370: Edge section 372: Butt joint surface

[0175] 380: Bent notch 390: Support surface

[0176] 400: Terminal 500: Terminal gasket

[0177] 600: Positive current collector 700: Insulator

[0178] H: Injection port

Claims

1. Electrode assembly; A cell housing for accommodating the above electrode assembly, wherein the cell housing comprises a side wall portion, an opening at a first end of the cell housing in the axial direction, and a bottom portion at a second end of the cell housing in the axial direction; and A can lid including a bent notch portion, an edge portion, and an electrode coupling portion; Includes, The above can lid is positioned to cover the opening of the cell housing, and The can lid includes a first surface spaced apart from the electrode assembly in the axial direction and a second surface facing the electrode assembly, A battery cell characterized in that the above-mentioned vent notch is formed on the first surface of the above-mentioned can lid.

2. A battery cell according to claim 1, characterized in that the vent notch portion is located radially between the electrode coupling portion and the edge portion.

3. A battery cell according to claim 1, wherein the bent notch portion has a V-shaped cross-section or a U-shaped cross-section in the axial direction.

4. A battery cell according to claim 1, wherein the vent notch portion defines a closed-loop shape along the first surface of the can lid.

5. A battery cell according to claim 1, wherein the can lid comprises a first plating layer on the first surface and the can lid comprises a second plating layer on the second surface.

6. A battery cell according to claim 1, wherein the can lid comprises a nickel-plated steel plate.

7. A battery cell according to claim 1, characterized in that the edge portion of the can lid is joined to the side wall portion of the cell housing at the first end portion of the cell housing.

8. A battery cell according to claim 1, characterized in that the electrode coupling portion of the can lid extends further into the interior of the cell housing in the axial direction than the edge portion of the can lid.

9. A battery cell according to claim 1, wherein the electrode coupling portion of the can lid contacts the electrode assembly, and the edge portion of the can lid is spaced apart from the electrode assembly.

10. A battery cell according to claim 1, wherein the can lid comprises a plurality of electrode coupling portions, and each of the plurality of electrode coupling portions contacts the electrode assembly.

11. A battery cell according to claim 10, characterized in that the plurality of electrode coupling portions are spaced apart from each other in the circumferential direction.

12. A battery cell according to claim 11, wherein the can lid comprises a plurality of bridges, and each of the plurality of bridges is located between adjacent electrode coupling portions in the circumferential direction.

13. A battery cell according to claim 10, characterized in that the plurality of electrode coupling portions are arranged rotationally symmetrically with respect to the center of the can lid.

14. A battery cell according to claim 1, wherein the can lid further comprises an injection port in the center.

15. A battery cell according to claim 14, wherein the can lid further comprises a flat portion surrounding the injection port, and the flat portion is located radially between the injection port and the electrode coupling portion.

16. A battery cell according to claim 1, wherein the electrode assembly comprises a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode.

17. A battery cell according to claim 16, wherein the first electrode comprises a first non-removable portion and the second electrode comprises a second non-removable portion, and the second non-removable portion of the second electrode is directly connected to the electrode coupling portion of the can lid.

18. A battery cell according to claim 17, wherein the bottom portion of the cell housing includes a through hole, the terminal extends through the through hole of the bottom portion, and the terminal is electrically connected to the first non-existent portion of the first electrode.

19. A battery pack comprising a battery cell according to any one of paragraphs 1 through 18.

20. An automobile comprising a battery pack pursuant to paragraph 19.

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