Battery cells, battery modules, battery packs and automobiles including the same

Abstract

A battery cell according to one embodiment of the present invention provides an electrode assembly in which first and second electrodes and a separator sandwiched therebetween are wound around a winding shaft to define a core and an outer peripheral surface, wherein the first electrode includes: an electrode assembly including a first uncoated region that is not coated with an active material layer along the winding direction; a battery housing having an open portion on one side and accommodating the electrode assembly through the open portion; a support portion disposed on an upper portion of the electrode assembly; a current collector including a tab connecting portion extending from the support portion and connected to the first uncoated region; and a housing connecting portion extending from the support portion and electrically connected to an inner surface of the battery housing, the housing connecting portion including at least one weld portion welded to the inner surface of the battery housing; and a housing cover covering the open portion, wherein the number of weld portions is less than or equal to the number of tab connecting portions, or a fracture portion configured to have a lower strength than a surrounding region is provided at the boundary between the support portion and the housing connecting portion.

Description

[Technical Field]

[0001] The present invention relates to a battery cell, a battery module, a battery pack, and a vehicle including the same.

[0002] This application claims priority based on Korean Patent Application No. 10-2022-0187775 filed on December 28, 2022 and Korean Patent Application No. 10-2023-0069489 filed on May 30, 2023, and the contents disclosed in the specifications and drawings of those applications are incorporated herein in their entirety. [Background technology]

[0003] Secondary batteries, which are easily applicable to various products and have electrical properties such as high energy density, are widely used not only in portable devices but also in electric vehicles (EVs) and hybrid electric vehicles (HEVs) that are driven by electrical sources. These secondary batteries not only have the temporary advantage of dramatically reducing the use of fossil fuels, but also have the advantage of not producing any by-products associated with energy use, and are therefore attracting attention as a new energy source that is environmentally friendly and improves energy efficiency.

[0004] Currently widely used types of secondary batteries include lithium ion batteries, lithium polymer batteries, nickel cadmium batteries, nickel metal hydride batteries, and nickel zinc batteries. The operating voltage of such a unit secondary battery cell, i.e., a unit battery cell, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, a battery pack may be configured by connecting multiple battery cells in series. Furthermore, depending on the charge / discharge capacity required for the battery pack, a battery pack may also be configured by connecting multiple battery cells in parallel. Therefore, the number of battery cells included in the battery pack may be variously set depending on the required output voltage and / or charge / discharge capacity.

[0005] On the other hand, conventional battery cells use an aluminum tab on the positive electrode to allow current to flow, and are designed to induce fusing of the aluminum tab, improving safety even when a high current flows instantaneously.

[0006] On the other hand, in the case of a battery cell having the structure of the present disclosure, the current collector plate and the foil tab are welded together for a low resistance design, and the positive current collector plate and the rivet are directly welded together. Therefore, since there is no separate electrode tab, it is not easy to achieve fusing. Even if the design of the positive current collector plate is changed to allow fusing, there is the inconvenience of an increase in the internal resistance of the battery cell. Summary of the Invention [Problem to be solved by the invention]

[0007] Therefore, an object of the present invention is to provide a current collector that can cut off current under conditions where a high current flows while minimizing an increase in the internal resistance of a battery cell.

[0008] However, the technical problems that the present invention aims to solve are not limited to the above-mentioned problems, and other problems not mentioned will be clearly understood by those skilled in the art from the description of the invention given below. [Means for solving the problem]

[0009] According to one embodiment of the present invention, a battery cell includes an electrode assembly in which a first electrode, a second electrode, and a separator sandwiched therebetween are wound around a winding shaft to define a core and an outer peripheral surface, the first electrode including a first uncoated region that is not coated with an active material layer along the winding direction; a battery housing having an opening on one side and accommodating the electrode assembly through the opening; a support disposed on an upper portion of the electrode assembly; a current collector including: a tab connecting portion extending from the support and connected to the first uncoated region; and a housing connecting portion extending from the support and electrically connected to an inner surface of the battery housing, the housing connecting portion including at least one weld portion connected by welding to the inner surface of the battery housing; and a housing cover covering the opening, wherein the number of the weld portions is less than or equal to the number of the tab connecting portions, or a breaking portion configured to have a lower strength than a surrounding region may be provided at a boundary between the support portion and the housing connecting portion.

[0010] Preferably, the number of the housing coupling portions may be configured to be even smaller than the number of the tab coupling portions.

[0011] In one aspect of the present invention, the housing coupling portion may include a contact portion coupled to an inner surface of the battery housing, and a connecting portion connecting the support portion and the contact portion.

[0012] Preferably, the connection portion and the contact portion may have the same width along the extension direction.

[0013] In another aspect of the present invention, a break portion may be provided at the boundary between the support portion and the housing coupling portion, the break portion being configured to have a strength lower than that of the surrounding area.

[0014] In yet another aspect of the present invention, the break portion may have the shape of a notch forming line including a plurality of notches.

[0015] In yet another aspect of the present invention, the housing coupling portion may be configured so that its length is extendable.

[0016] Preferably, at least a portion of the housing coupling portion may have the shape of a rim with a hollow center.

[0017] In yet another aspect of the present invention, the housing cover may include a vent configured to rupture if pressure inside the battery housing increases above a certain level.

[0018] Preferably, the radial length of the vent portion may be configured to be greater than the radial length of the support portion.

[0019] In yet another aspect of the present invention, the battery housing may include a beading portion formed on an end adjacent to the open portion and pressed inward.

[0020] Here, the battery cell may include an insulator interposed between the beading portion and the electrode assembly.

[0021] Preferably, the insulator may be configured to have a shape that is matched with the inner surface of the beading portion.

[0022] Meanwhile, the present invention provides a battery pack including at least one battery cell according to the above-described embodiments.

[0023] The present invention also provides a motor vehicle, the motor vehicle including at least one battery pack according to the above-described embodiment. [Effects of the Invention]

[0024] According to the present invention, it is possible to provide a current collector that can interrupt current under conditions where a high current flows, while minimizing an increase in the internal resistance of the battery cell.

[0025] However, the effects obtained through the present invention are not limited to the above-mentioned effects, and other technical effects not mentioned will be clearly understood by those skilled in the art from the description of the invention described below.

[0026] The drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further understand the technical concepts of the present invention as well as the content of the invention, and therefore the present invention should not be interpreted as being limited to only the matters depicted in the drawings. [Brief explanation of the drawings]

[0027] [Figure 1] 1 is a diagram illustrating a battery cell according to an embodiment of the present invention; [Figure 2] FIG. 2 is a vertical cross-sectional perspective view of FIG. [Figure 3] FIG. 2 is a vertical cross-sectional view of the battery cell in FIG. [Figure 4] FIG. 2 is a diagram illustrating a current collector according to an embodiment of the present invention. [Figure 5] FIG. 10 is a diagram illustrating a current collector corresponding to a comparative example of the present invention. [Figure 6] FIG. 2 is a diagram illustrating a current collector according to an embodiment of the present invention. [Figure 7] FIG. 10 is a diagram illustrating a current collector according to another embodiment of the present invention. [Figure 8] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 9] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 10] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 11] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 12] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 13] FIG. 10 is a diagram illustrating a current collector according to still another embodiment of the present invention. [Figure 14] FIG. 14 is a diagram illustrating a state in which the current collector in FIG. 13 is stretched. [Figure 15] 10A and 10B are diagrams illustrating a state after venting in a battery cell according to an embodiment of the present invention. [Figure 16] 16 is a diagram for explaining the battery cell in FIG. 15 as viewed from the outside. FIG. [Figure 17] 10A and 10B are diagrams illustrating a battery cell according to another embodiment of the present invention. [Figure 18] 10A and 10B are diagrams illustrating a battery cell according to still another embodiment of the present invention. [Figure 19] 1 is a diagram illustrating a battery pack including a battery cell according to an embodiment of the present invention; [Figure 20] FIG. 20 is a diagram for explaining a car including the battery pack in FIG. 19. DETAILED DESCRIPTION OF THE INVENTION

[0028] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. Prior to this, the terms and words used in this specification and claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts corresponding to the technical ideas of the present invention, in accordance with the principle that the inventor can appropriately define the concepts of terms himself / herself in order to best describe the invention. Therefore, it should be understood that the embodiment described in this specification and the configuration shown in the drawings are merely a preferred embodiment of the present invention and do not represent the entire technical ideas of the present invention, and therefore, various equivalent and modified embodiments may be available as of the time of filing this application.

[0029] In addition, in order to facilitate understanding of the invention, the accompanying drawings may not be drawn to scale, and the dimensions of some components may be exaggerated. In addition, the same reference numerals may be used for the same components in different embodiments.

[0030] A statement that two comparison objects are identical means that they are "substantially identical." Therefore, being substantially identical may include cases where there is a deviation that is recognized as a low level in the art, for example, a deviation of 5% or less. Furthermore, the uniformity of a certain parameter in a given region may mean that it is uniform from an average perspective.

[0031] Although phrases such as "first" and "second" can be used to describe various components, it goes without saying that these components are not limited by these phrases in any way. These phrases are used merely to distinguish one component from another, and unless otherwise specified, it goes without saying that a first component may also be a second component.

[0032] Throughout the specification, unless otherwise indicated herein or clearly contradicted by context, each element is to be construed as covering both the singular and the plural.

[0033] The phrase "above (or below)" a component or "above (or below)" a component means that the component is placed in contact with the upper surface (or lower surface) of the component, and may also mean that there may be other components interposed between the component and the component placed above (or below) the component.

[0034] Furthermore, when a component is described as being "coupled," "coupled," or "connected" to another component, it should be understood that the components may be directly coupled or connected to each other, or that other components may be "intervening" between the components, or that the components may be "coupled," "coupled," or "connected" via other components.

[0035] Throughout the specification, when "A and / or B" is used, this means A, B or A and B, unless otherwise specified in the specification or clearly contradicted by the context, and when "C to D" is used, this means C or more and D or less, unless otherwise specified.

[0036] For ease of explanation, in this specification, the direction along the longitudinal direction of the winding shaft of the electrode assembly 10 wound in a jelly roll shape will be referred to as the axial direction Y. The direction surrounding the winding shaft will be referred to as the circumferential direction or the peripheral direction X. The direction toward the winding shaft or the direction away from the winding shaft will be referred to as the radial direction. Of these, the direction toward the winding shaft will be particularly referred to as the centripetal direction, and the direction away from the winding shaft will be particularly referred to as the centrifugal direction.

[0037] Fig. 1 is a diagram for explaining a battery cell 1 according to one embodiment of the present invention, and Fig. 2 is a vertical cross-sectional perspective view of Fig. 1. Fig. 3 is a vertical cross-sectional view of the battery cell 1 in Fig. 1.

[0038] 1, a battery cell 1 according to one embodiment of the present invention includes an electrode assembly 10, a battery housing 20, a current collector 30, and a housing cover 40. In addition to the above, the battery cell 1 may further include an insulator S and / or a terminal 50 and / or a seal gasket G1 and / or an insulating gasket G2 and / or a second current collector 60 and / or an insulator 70. The present invention is not limited by the shape of the battery, and may also be applied to batteries of other shapes, such as prismatic batteries.

[0039] The electrode assembly 10 includes a first uncoated region 11 and a second uncoated region 12. More specifically, the electrode assembly 10 has a structure in which a first electrode, a second electrode, and the separator sandwiched therebetween are wound around a winding shaft to define a core and an outer circumferential surface. That is, the electrode assembly 10 applied to the embodiment of the present invention may be a jelly roll-type electrode assembly 10. In this case, an additional separator may be provided on the outer circumferential surface of the electrode assembly 10 for insulation from the battery housing 20. The electrode assembly 10 may have any winding structure known in the art, without limitation.

[0040] The first electrode includes a first electrode current collector and a first electrode active material coated on one or both sides of the first electrode current collector. An uncoated portion, where the first electrode active material is not coated, is present at one end of the first electrode in the width direction (the direction parallel to the height direction of the battery cell 1 shown in FIG. 1 ). That is, the first electrode includes a uncoated portion at the end of the long side along the winding direction that is not coated with an active material and is exposed to the outside of the separator. Hereinafter, the uncoated portion functioning as the first electrode tab will be referred to as the first uncoated portion 11. The first uncoated portion 11 is provided at the upper portion of the electrode assembly 10 housed in the battery housing 20 in the height direction (the direction parallel to the height direction of the battery cell 1 shown in FIG. 1 ). That is, the first electrode includes a first uncoated portion 11 at the end of the long side that is not coated with an active material layer and is exposed to the outside of the separator, and at least a portion of the first uncoated portion 11 itself is used as an electrode tab. The first uncoated portion 11 may be, for example, a negative electrode tab.

[0041] Meanwhile, at least a portion of the first uncoated portion 11 may include a plurality of segments separated along the winding direction of the electrode assembly 10. In this case, the plurality of segments may be bent along the radial direction of the electrode assembly 10.

[0042] 2 and 3, the plurality of segments of the bent first non-coating portion 11 may overlap in multiple layers to form a folded surface. In this case, a tab connection portion 32 of a current collector 30 (described later) may be bonded to the folded surface. The tab connection portion 32 may be bonded to a region where the plurality of segments overlap in multiple layers. In this case, welding may be performed on a certain region while the tab connection portion 32 is placed on the folded surface of the first non-coating portion 11. That is, the tab connection portion 32 may be bonded to a region where the plurality of segments of the first non-coating portion 11 overlap in multiple layers. For example, as can be seen from FIG. 5, the tab connection portion 32 may have at least one weld TW welded to a certain region while placed on the folded surface of the first non-coating portion 11.

[0043] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both sides of the second electrode current collector. The other end of the second electrode in the width direction (the direction parallel to the height direction of the battery cell 1 shown in FIG. 1 ) has an uncoated portion where the second electrode active material is not coated. That is, the second electrode includes a uncoated portion at the end of the long side along the winding direction that is not coated with an active material and is exposed to the outside of the separator. Hereinafter, the uncoated portion functioning as the second electrode tab will be referred to as the second uncoated portion 12. The second uncoated portion 12 is provided at the lower part of the height direction of the electrode assembly 10 housed in the battery housing 20. That is, the second electrode includes a second uncoated portion 12 at the end of the long side that is not coated with an active material layer and is exposed to the outside of the separator, and at least a portion of the second uncoated portion 12 itself can be used as an electrode tab. The second uncoated portion 12 may be, for example, a positive electrode tab.

[0044] Meanwhile, in the embodiment of the present invention, the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate may be any active material known in the art without any limitation.

[0045] Referring to FIG. 1, the battery housing 20 is a generally cylindrical container having an opening on one side and is made of a conductive metal material. The side surface of the battery housing 20 and the bottom surface opposite the opening are generally formed as a single unit. That is, the battery housing 20 generally has an open upper end in its height direction and a closed lower end. The bottom surface of the battery housing 20 may have a generally flat shape. The battery housing 20 accommodates the electrode assembly 10 through an opening formed on one side in its height direction. The battery housing 20 may also accommodate an electrolyte through the opening.

[0046] The battery housing 20 may include a beading portion 21 formed at an end adjacent to an opening provided at the upper end of the battery housing 20. The battery housing 20 may further include a clamping portion 22 formed on the beading portion 21. The beading portion 21 has a shape in which the periphery of the battery housing 20 is pressed to a predetermined depth. More specifically, the beading portion 21 may have a shape in which the periphery of the battery housing 20 is pressed inward in a region between an opening formed on one side of the battery housing 20 and a receiving portion that receives the electrode assembly 10.

[0047] The beading portion 21 is formed on the upper portion of the electrode assembly 10. The inner diameter of the battery housing 20 in the area where the beading portion 21 is formed is formed to be smaller than the diameter of the electrode assembly 10. At least one tab coupling portion 32 of the current collector 30, which will be described later, may be located further below the beading portion 21.

[0048] The beading portion 21 provides a support surface on which the housing cover 40 can be placed. The beading portion 21 may also provide a support surface on which at least a portion of the peripheral edge of the current collector 30 (described later) can be placed and coupled. That is, at least a portion of the peripheral edge of the current collector 30 and / or the peripheral edge of the housing cover 40 according to an embodiment of the present invention may be placed on the upper surface of the beading portion 21. To stably support at least a portion of the peripheral edge of the current collector 30 and / or the peripheral edge of the housing cover 40, the upper surface of the beading portion 21 may have a shape extending in a direction generally aligned with the lower surface of the battery housing 20, i.e., in a direction generally perpendicular to the sidewall of the battery housing 20.

[0049] The beading portion 21 prevents the electrode assembly 10, which has a size roughly corresponding to the inner diameter of the battery housing 20, from slipping out through an opening formed at the upper end of the battery housing 20, and can function as a support portion on which the housing cover 40 is placed. The upper beading portion 21 can function as a support portion for fixing not only the housing cover 40 but also the contact portion 33a of the current collector 30, the seal gasket G1, etc.

[0050] The clamping portion 22 is formed on the upper portion of the beading portion 21. The clamping portion 22 has an extended and curved shape so as to enclose the peripheral portion of the housing cover 40 disposed on the upper portion of the beading portion 21. Due to the shape of the clamping portion 22, the housing cover 40 is fixed onto the beading portion 21.

[0051] Next, a current collector 30 according to an embodiment of the present invention will be described in detail in comparison with a conventional current collector with reference to FIGS.

[0052] 1 and 2, a current collector 30 according to an embodiment of the present invention is housed inside a battery housing 20 and is electrically connected to the electrode assembly 10 and the battery housing 20. That is, the current collector 30 electrically connects the electrode assembly 10 and the battery housing 20.

[0053] FIG. 4 is a diagram illustrating a current collector 30 according to one embodiment of the present invention.

[0054] Referring to FIG. 4, the current collector 30 includes a support portion 31 located on one side of the electrode assembly 10, a plurality of tab connecting portions 32 extending from the support portion 31 and connecting to the first plain portion 11, and a plurality of housing connecting portions 33 extending from the support portion 31 and connecting to the inner surface of the battery housing 20.

[0055] The tab coupling portion 32 and the housing coupling portion 33 are indirectly connected via the support portion 31 and are not directly connected to each other. Therefore, when an external impact is applied to the battery cell 1 according to an embodiment of the present invention, the possibility of damage to the coupling portion between the current collector 30 and the electrode assembly 10 and the coupling portion between the current collector 30 and the battery housing 20 can be minimized.

[0056] 4, there may be at least one or more tab coupling portions 32 and / or housing coupling portions 33. The at least one tab coupling portion 32 and the at least one housing coupling portion 33 may be arranged, for example, in a substantially radial pattern, a cross pattern, or a combination thereof, with respect to the center of the current collector 30. In another embodiment, each of the multiple housing coupling portions 33 may be arranged between adjacent tab coupling portions 32.

[0057] 3, the support portion 31 and the plurality of tab connecting portions 32 are disposed on the upper portion of the electrode assembly 10. The tab connecting portions 32 are connected to the first uncoated portion 11 of the electrode assembly 10. The tab connecting portions 32 may be connected to the first uncoated portion 11 by welding along the radial direction of the electrode assembly 10, for example. The tab connecting portions 32 may be connected to the first uncoated portion 11 by welding in a state generally parallel to the lower surface of the battery housing 20, for example. Referring to FIG. 4, the welds TW formed between the first uncoated portion 11 and the tab connecting portions 32 may form a generally linear weld pattern extending along the radial direction of the electrode assembly 10, for example.

[0058] Meanwhile, not only the tab coupling portion 32 but also the support portion 31 may be coupled to the first uncoated portion 11. The tab coupling portion 32 and the first uncoated portion 11 may be coupled by welding. When a beading portion 21 is formed on the battery housing 20, the support portion 31 and the tab coupling portion 32 are located below the beading portion 21.

[0059] The support portion 31 may have a current collector hole H2 formed at a position corresponding to a winding hole H1 formed in approximately the center of the electrode assembly 10. The winding hole H1 and the current collector hole H2, which are connected to each other, may function as a passage for inserting a welding rod or irradiating a laser beam for welding the terminal 50 to the second current collector 60 (described later) or for welding the terminal 50 to a lead tab (not shown). The current collector hole H2 may have a diameter substantially the same as or larger than the diameter of the winding hole H1 of the electrode assembly 10 so as not to obstruct the winding hole H1 formed in the core of the electrode assembly 10. If the diameter of the current collector hole H2 is excessively smaller than the diameter of the winding hole H1, the hole formed in the winding hole H1 may be obstructed, resulting in a decrease in liquid injection performance and a risk of making it difficult to secure sufficient space for inserting a welding device or for irradiating a laser.

[0060] The plurality of tab bonding portions 32 may have a shape that extends generally radially from the support portion 31 of the current collector 30 toward the side wall of the battery housing 20. Each of the plurality of tab bonding portions 32 may be located apart from one another along the circumference of the support portion 31.

[0061] The multiple housing joints 33 may have a shape that extends substantially radially from the support portion 31 of the current collector 30 toward the side wall of the battery housing 20. Each of the multiple housing joints 33 may be located apart from one another along the circumference of the support portion 31. At least one housing joint 33 may be located between adjacent tab joints 32.

[0062] The housing coupling portion 33 may extend from the support portion 31 and be electrically coupled to the inner surface of the battery housing 20. For example, the housing coupling portion 33 may be coupled to the inner surface of the battery housing 20, such as the beading portion 21. In particular, the housing coupling portion 33 may be coupled to the upper surface of the beading portion 21.

[0063] When this structure is adopted in the battery cell 1 according to an embodiment of the present invention, the electrode assembly 10, to which the current collector 30 is coupled, can be placed on the beading portion 21 by using a process of accommodating the electrode assembly 10, to which the current collector 30 is coupled, in the battery housing 20. Therefore, the welding process between the battery housing 20 and the current collector 30 can be easily performed. For example, as can be seen from FIG. 6 , at least one weld BW may be included between the beading portion 21 and the housing coupling portion 33. That is, the current collector 30 may include at least one weld BW that is coupled to the inner surface of the battery housing 20 by welding. The welding for coupling the battery housing 20 and the current collector 30 can be, for example, laser welding, ultrasonic welding, or spot welding. In addition, the upper surface of the beading portion 21 is shaped to extend in a direction that is generally aligned with the lower surface of the battery housing 20, i.e., in a direction that is generally perpendicular to the side wall of the battery housing 20, and the housing coupling portion 33 is similarly shaped to extend in the same direction, i.e., in the radial and circumferential directions, so that the housing coupling portion 33 can stably contact the beading portion 21. Furthermore, since the housing coupling portion 33 stably contacts the beading portion 21 in this manner, welding between the two parts can be performed smoothly, thereby achieving the effects of improving the bonding strength between the two parts and minimizing an increase in resistance at the bonding site.

[0064] 3 and 4, the housing coupling portion 33 includes a contact portion 33a coupled to the inner surface of the battery housing 20 and a connection portion 33b connecting the support portion 31 and the contact portion 33a. In one embodiment of the present invention, the first tab coupling portion 32 may have a width greater than that of the connection portion 33b. In another embodiment of the present invention, the contact portion 33a may have a width greater than that of the connection portion 33b.

[0065] The contact portion 33a is bonded onto the inner surface of the battery housing 20. In the case where the beading portion 21 is formed on the battery housing 20, the contact portion 33a may be bonded onto the beading portion 21 as described above. In this case, for stable contact and bonding, both the beading portion 21 and the contact portion 33a may have a shape extending in a direction that is generally aligned with the lower surface of the battery housing 20, i.e., in a direction that is generally perpendicular to the side wall of the battery housing 20.

[0066] Meanwhile, the contact portion 33a may be joined to the upper surface of the beading portion 21 by welding. That is, the welded portion BW may be formed in the upper surface region of the beading portion 21. The welded portion BW formed between the contact portion 33a and the beading portion 21 may be formed to be narrower than the upper surface of the beading portion 21.

[0067] The contact portion 33a may have an arc shape, at least a portion of which extends circumferentially along the beading portion 21 of the battery housing 20. This allows the circumferential extension length of the contact portion 33a to be formed to be longer than the width of the connecting portion 33b. In this case, to maximize the contact area, the current collector 30 may be configured so that the sum of the circumferential extension lengths of the contact portions 33a of the multiple housing coupling portions 33 is substantially equal to or shorter than the inner circumference of the battery housing 20. According to another embodiment, the contact portions 33a may have arc shapes extending in opposite directions along the circumferential direction on the beading portion 21 from the intersection of the connecting portion 33b and the contact portion 33a.

[0068] Referring to FIG. 4, the current collector 30 according to an embodiment of the present invention may include at least one liquid inlet H3. The liquid inlet H3 may be provided, for example, in the tab coupling portion 32. When a plurality of tab coupling portions 32 are provided, the liquid inlet H3 may be provided in at least one of the tab coupling portions 32. The liquid inlet H3 may be provided, for example, on one side or both sides of at least one weld TW formed on the tab coupling portion 32. Referring to FIGS. 3 and 4, in manufacturing the battery cell 1 according to an embodiment of the present invention, an electrolyte may be injected after the assembly including the electrode assembly 10 and the current collector 30 is housed in the battery housing 20. At this time, the liquid inlet H3 improves the liquid inlet efficiency. A plurality of liquid inlet holes H3 may be provided in one tab coupling portion 32. The plurality of liquid inlet holes H3 may be arranged approximately symmetrically on the left and right sides with respect to the center of the tab coupling portion 32 in the width direction. In this way, a welded portion TW for joining the tab joining portion 32 and the first uncoated portion 11 can be formed between the liquid filling holes H3 arranged so as to be approximately symmetrical on the left and right.

[0069] 4, the distance A from the center of the current collector 30 to the end of the tab coupling portion 32 may be formed to be substantially equal to or shorter than the distance B from the center of the winding hole H1 of the electrode assembly 10 to the innermost portion of the beading portion 21 formed on the battery housing 20. In this case, it is possible to prevent interference between the beading portion 21 and the current collector 30 during the sizing process, thereby preventing the beading portion 21 from pressing the current collector 30 and damaging the current collector 30 and / or the electrode assembly 10. In addition, as will be described later, if vent gas is generated inside the battery cell 1, the vent gas may cause the current collector 30 to detach upward. In this case, the distance A from the center of the current collector 30 to the end of the tab coupling portion 32 must be substantially equal to or shorter than the distance B from the center of the winding hole H1 of the electrode assembly 10 to the innermost part of the beading portion 21 formed on the battery housing 20, otherwise the current collector 30 will not be able to smoothly detach upward from the battery cell 1. In other words, this structure maximizes the upward movement and distance of the current collector 30.

[0070] 4, at least one weld TW may be provided for each tab connection portion 32. The weld TW may be formed not only at the tab connection portion 32 but also at the support portion 31 of the current collector 30.

[0071] As described above, a flat portion may be provided on the beading portion 21. At least one weld BW may be formed between the beading portion 21 and the contact portion 33a. At least one weld BW may form a linear weld pattern extending substantially along the circumferential direction on the beading portion 21. Alternatively, in another embodiment of the present invention, at least one weld BW formed between the beading portion 21 and the contact portion 33a may form an arc-shaped weld pattern extending substantially along the circumferential direction on the beading portion 21. The weld BW formed on the contact portion 33a may have a shape extending along the circumferential direction.

[0072] In one embodiment of the present invention, the total number of welds BW formed on the contact portion 33a is less than or equal to the number of tab coupling portions 32. The number of welds BW formed on the contact portion 33a will be described in detail below with reference to FIGS.

[0073] FIG. 5 is a diagram illustrating a conventional current collector 30 corresponding to a comparative example of the present invention, and FIG. 6 is a diagram illustrating a current collector 30 according to one embodiment of the present invention.

[0074] 5, in the conventional current collector 30, the number of welds BW formed on the contact portion 33a is configured to be greater than the number of tab coupling portions 32. This improves the bonding strength between the battery housing 20 and the current collector 30. However, in this case, when venting occurs within the battery cell 1, the bonding strength between the battery housing 20 and the current collector 30 is strong, which is inconvenient as the current collector 30 does not detach smoothly. That is, because the housing coupling portion 33 of the current collector 30 is strongly bonded onto the beading portion 21 of the battery housing 20, there is a limit to the increase in the upward movement distance of the current collector 30.

[0075] In contrast, referring to Fig. 6 showing a current collector 30 according to an embodiment of the present invention, the number of welds BW formed on the contact portions 33a may be the same as the number of tab coupling portions 32. That is, according to an embodiment of the present invention, the number of welds BW is reduced compared to the conventional current collector 30. For example, in Fig. 6, one weld BW may be provided on each contact portion 33a, for a total of four welds BW. Meanwhile, four tab coupling portions 32 may be provided.

[0076] FIG. 7 is a diagram illustrating a current collector 30 according to another embodiment of the present invention.

[0077] 7, the number of welds BW formed on the contact portion 33a can be configured to be even smaller than the number of tab bonding portions 32. For example, in FIG. 7, a total of two welds BW can be provided on the contact portion 33a. Meanwhile, four tab bonding portions 32 can be provided.

[0078] In this manner, a structure in which the number of welds BW formed on the contact portion 33a is less than or equal to the number of tab coupling portions 32 weakens the coupling force between the housing coupling portion 33 and the battery housing 20. As a result, the current collector 30 can be more easily deformed upward when the battery cell 1 is vented. That is, the upward movement distance of the current collector 30 can be further increased when the battery cell 1 is vented. For example, because the coupling force between the contact portion 33a and the beading portion 21 is weakened, the contact portion 33a can be separated from the beading portion 21, to which it was welded, by the vent gas ejected upward. At the same time, the welded connection between the first non-coating portion 11 and the current collector 30, which was welded to the current collector 30, can be released. As a result, the shape of the current collector 30 is deformed to bend upward, allowing the current collector 30 to move upward. Therefore, the current collector 30 can be smoothly detached from the first non-coating portion 11. As a result, the fusing characteristics within the battery cell 1 are enhanced.

[0079] On the other hand, Figures 6 and 7 merely correspond to one embodiment of the present invention, and it goes without saying that the number of welded portions BW and the number of tab connecting portions 32 are not limited to the numbers shown in Figures 6 or 7.

[0080] Meanwhile, the housing coupling portion 33 coupled onto the beading portion 21 can maintain a certain level of resistance even if the number of welds BW is relatively small. However, if the number of welds TW between the first plain portion 11 and the tab coupling portion 32 is reduced, the internal resistance of the battery cell 1 increases sharply and the degree of resistance dispersion increases significantly. Therefore, reducing the number of welds TW between the first plain portion 11 and the tab coupling portion 32 is not preferable from a process perspective. Therefore, it is preferable to ensure fusing characteristics by reducing the number of welds BW between the inner surface of the battery housing 20 and the housing coupling portion 33.

[0081] 8 to 13 are diagrams illustrating a current collector 30 according to still another embodiment of the present invention, and FIG. 14 is a diagram illustrating a state in which the current collector 30 in FIG. 13 has been stretched.

[0082] The current collector 30 shown in Figures 8 to 14 is substantially similar to the current collector 30 of the above-mentioned embodiment, so redundant explanations of configurations that are substantially the same as or similar to those of the above-mentioned embodiment will be omitted, and the following description will focus on the differences from the above-mentioned embodiment.

[0083] In another embodiment of the present invention, the number of the housing coupling portions 33 can be configured to be even less than the number of the tab coupling portions 32 .

[0084] For example, referring to Fig. 8, the number of the housing coupling portions 33 may be configured to be smaller than the number of the tab coupling portions 32. In Fig. 8, the number of the housing coupling portions 33 may be two, while the number of the tab coupling portions 32 may be four.

[0085] In this manner, a structure in which the number of housing coupling portions 33 is configured to be smaller than the number of tab coupling portions 32 weakens the coupling force between the housing coupling portions 33 and the battery housing 20. As a result, the current collector 30 can be more easily deformed upward when the battery cell 1 is vented. That is, the upward movement distance of the current collector 30 can be further increased when the battery cell 1 is vented. As the current collector 30 is deformed while being turned upside down in this manner, the coupling between the first non-coating portion 11 and the current collector 30, which was welded to the current collector 30, can be easily released. That is, the current collector 30 can be smoothly detached from the first non-coating portion 11. Therefore, the fusing characteristics within the battery cell 1 are enhanced.

[0086] 8 merely corresponds to one embodiment of the present invention, and it goes without saying that the number of housing coupling portions 33 and the number of tab coupling portions 32 are not limited to those shown in FIG. 8 . However, it is preferable that the shape of the current collector 30 is symmetrical with respect to a line passing through the center of the current collector 30. For example, as shown in FIG. 8 , when two housing coupling portions 33 are provided, it is preferable that they are configured symmetrically by providing one on each side of the line passing through the center of the current collector 30 as the reference. Alternatively, another embodiment may be envisioned in which three housing coupling portions 33 and three tab coupling portions 32 are configured symmetrically with respect to the line passing through the center of the current collector 30 as the reference. Therefore, in such an embodiment, three housing coupling portions 33 may be formed at intervals of 120° from each other, and three tab coupling portions 32 may be formed at intervals of 120° from each other.

[0087] In yet another embodiment of the present invention, the connecting portion 33b and the contact portion 33a may be configured to have substantially the same width along the extending direction.

[0088] For example, referring to FIG. 9, the connection portion 33b and the contact portion 33a have substantially the same width. According to this structure, the width is narrower than the connection portion 33b of the current collector 30 shown in FIG. 6 and other figures. That is, the area of the contact portion 33a coupled to the beading portion 21 is narrower, and therefore the coupling force between the contact portion 33a and the beading portion 21 is also reduced. Therefore, the coupling force between the housing coupling portion 33 and the battery housing 20 is weakened. This allows the current collector 30 to more easily deform upward when the battery cell 1 is vented. That is, the upward movement distance of the current collector 30 can be further increased when the battery cell 1 is vented. That is, the current collector 30 can be smoothly detached from the electrode assembly 10. Therefore, the fusing characteristics within the battery cell 1 are enhanced.

[0089] 10, in yet another embodiment of the present invention, the connection portion 33b and the contact portion 33a may be configured to have substantially the same width along the extension direction, and at the same time, the number of welds BW formed on the contact portion 33a may be configured to be smaller than the number of tab coupling portions 32. With this structure, the coupling force between the housing coupling portion 33 and the battery housing 20 is further reduced compared to the current collector 30 of FIG. 9, thereby further enhancing the fusing characteristics.

[0090] In yet another embodiment of the present invention, a break portion NL may be provided at the boundary between the support portion 31 and the housing coupling portion 33, which is configured to have a lower strength than the surrounding region. That is, the break portion NL may be configured to be structurally weaker than the surrounding region. For example, the break portion NL may be configured to have a thinner thickness than the surrounding region. Alternatively, the break portion NL may be configured to have a lower density than the surrounding region.

[0091] 11, a break portion NL may be provided at the boundary between the support portion 31 and the housing coupling portion 33. For example, the break portion NL may have the shape of a notch forming line including a plurality of notches. That is, the break portion NL may be provided in a substantially linear shape. More specifically, the break portion NL may be provided at the boundary between the support portion 31 and the connecting portion 33b. Although not shown, in another embodiment, the break portion NL may be provided on the connecting portion 33b. Alternatively, the break portion NL may be provided at the boundary between the connecting portion 33b and the contact portion 33a.

[0092] In this structure in which the breaking portion NL is provided at the boundary between the support portion 31 and the housing coupling portion 33, when the current collector 30 is bent upward and deformed during venting of the battery cell 1, strong pressure is applied to the breaking portion NL, causing a break at the breaking portion NL. As a result, the support portion 31 of the current collector 30 can be separated from the housing coupling portion 33. At this time, the tab coupling portion 32, which was welded to the first plain portion 11, can also be separated from the housing coupling portion 33. That is, when venting occurs, the breaking portion NL is torn, and the current collector 30 is separated into a portion including the support portion 31 and the tab coupling portion 32 and another portion corresponding to the housing coupling portion 33. As a result, the fusing characteristics are enhanced due to the breaking at the breaking portion NL.

[0093] Meanwhile, in this case, an insulator S, which will be described later, may be interposed between the beading portion 21 and the electrode assembly 10. In this case, the insulator S can more reliably prevent the electrical connection between the electrode assembly 10 and the battery housing 20 via the beading portion 21 from continuing.

[0094] In yet another embodiment of the present invention, a breaking portion NL may be provided at the boundary between the support portion 31 and the tab connecting portion 32 so as to have a lower strength than the surrounding area.

[0095] For example, referring to FIG. 12, a break portion NL may be provided not only at the boundary between the support portion 31 and the housing connecting portion 33 but also at the boundary between the support portion 31 and the tab connecting portion 32 .

[0096] According to this structure, when the current collector 30 is deformed upward during venting, strong pressure is applied to the breaking portion NL, causing a break at the breaking portion NL, and therefore, only the support portion 31 of the current collector plate can be separated from the surrounding area of the support portion 31. Because the support portion 31 serves to indirectly connect the tab coupling portion 32 and the housing coupling portion 33, when the support portion 31 is separated from the current collector 30, the electrical connection between the tab coupling portion 32 and the housing coupling portion 33 can be cut off. Furthermore, in this embodiment, because the breaking portion NL is provided along the periphery of the support portion 31, the probability of the support portion 31 being detached during venting is further increased. This further strengthens the fusing characteristics.

[0097] In yet another embodiment of the present invention, the housing coupling portion 33 may be configured so that its length is extendable.

[0098] 13 and 14, the housing coupling part 33 may be configured so that the length when the housing coupling part 33 is pulled is greater than the length when the housing coupling part 33 is not pulled. For example, at least a portion of the housing coupling part 33 may be configured to have a rim shape with a hollow center. In particular, the connection part 33b of the housing coupling part 33 may be configured to have a rim shape with a hollow center.

[0099] Here, the rim shape includes, but is not necessarily limited to, a circle. For example, the rim shape referred to in this invention may be a polygonal structure such as a triangle or a rectangle, or may have a specific shape with curved edges. In other words, the rim shape referred to in this invention can be said to encompass any shape that has a hollow center and continuous edges.

[0100] For example, in one embodiment of the present invention, at least a portion of the housing coupling portion 33 may be configured to have an oval ring shape in plan view, as shown in Fig. 13. In particular, the plan view of the connecting portion 33b of the housing coupling portion 33 may have an oval ring shape. Here, the elongation of the connecting portion 33b may lengthen the major axis of the oval and shorten the minor axis. Alternatively, although not shown, in yet another embodiment of the present invention, the housing coupling portion 33 may have a diamond shape in plan view.

[0101] This structure allows the connection portion 33b to be easily stretched when the current collector 30 is assembled to the battery cell 1. That is, the current collector 30, which is manufactured from a single, seamless plate material without the need for a separate structure, can be stretched without wrinkling or breakage. Specifically, referring to FIG. 3 , the support portion 31 of the current collector 30 is spaced a predetermined distance from the contact portion 33a of the housing coupling portion 33 of the current collector 30 in the direction of the central axis of the battery cell 1. To achieve this state, the current collector 30, which has a planar shape as shown in FIG. 13 , must be deformed while being stretched vertically. For example, bending may occur at the boundary between the support portion 31 and the connection portion 33b and at the boundary between the connection portion 33b and the contact portion 33a. In this case, the length of the connection portion 33b must be increased in order to maintain a constant radial length from the center of the current collector 30 to the end of the housing coupling portion 33. Therefore, as shown in FIG. 14, when the housing coupling part 33 is bent, the shape of the oval ring is deformed, and the housing coupling part 33 can be stretched along its extending direction.

[0102] 1 to 3, the housing cover 40 may include a vent portion 41 formed to prevent an increase in internal pressure due to gas generated inside the battery housing 20. The vent portion 41 may be configured to rupture when the internal pressure of the battery housing 20 increases above a certain level. For example, the vent portion 41 may be formed in a portion of the housing cover 40 and may be a region that is structurally weaker than the surrounding region so that it can be easily ruptured when internal pressure is applied. The vent portion 41 may be, for example, a region that is thinner than the surrounding region. Referring to FIGS. 1 and 2, the vent portion 41 may form a substantially circular closed loop.

[0103] In one embodiment of the present invention, the radial length of the vent portion 41 may be configured to be greater than the radial length of the support portion 31. Preferably, the radial length of the vent portion 41 may be formed to be greater than the distance A from the center of the current collector 30 to the end of the tab coupling portion 32.

[0104] 2 and 3, the distance from the center of the current collector 30 to the outermost point of the support portion 31 may be configured to be smaller than the distance from the center of the housing cover 40 to the vent portion 41. With this structure, when the battery cell 1 is vented, the area inside the vent portion 41 is detached, thereby facilitating the process of the current collector 30 being turned over to the outside of the battery cell 1. Preferably, when the radial length of the vent portion 41 is configured to be larger than the distance A from the center of the current collector 30 to the end of the tab coupling portion 32, the process of the current collector 30 being turned over to the outside of the battery cell 1 may be more easily performed. This will be described in detail below with reference to FIGS. 15 and 16.

[0105] FIG. 15 is a diagram illustrating the state after venting in a battery cell 1 according to one embodiment of the present invention, and FIG. 16 is a diagram illustrating the battery cell 1 in FIG. 15 as viewed from the outside.

[0106] A thermal event may occur inside the battery cell 1 for some reason, generating vent gas, which may increase the pressure inside the battery housing 20. At this time, the vent portion 41 may rupture because it corresponds to a structurally weaker area than the surrounding area and is more likely to rupture when the pressure inside the battery cell 1 increases. As a result, as shown in FIGS. 15 and 16 , the portion of the housing cover 40 corresponding to the inner area of the vent portion may be torn upward. That is, when viewed from above the battery cell 1, the inner area of the vent portion 41 appears completely open. At the same time, as shown in FIGS. 15 and 16 , the high-pressure vent gas ejected upward may cause the portion of the housing cover 40 corresponding to the outer area of the vent portion 41 to bend upward.

[0107] Meanwhile, the high-pressure vent gas ejected upward can also detach the current collector 30 upward. That is, the welded joint TW between the current collector 30 and the first uncoated portion 11 can be torn. As a result, the current collector 30 can move upward as shown in FIGS. 15 and 16 . Among various portions of the current collector 30, the support portion 31 has the largest movement distance. Therefore, in order for the support portion 31 to move smoothly to the outside of the battery cell 1, it is preferable that the detached region of the housing cover 40 be larger than or equal to the size of the support portion 31. That is, according to an embodiment of the present invention, a structure in which the radial length of the vent portion 41 is larger than or equal to the radial length of the support portion 31 can maximize the upward movement distance of the current collector 30.

[0108] On the other hand, in a structure in which the total number of welds BW formed on the contact portions 33a is configured to be less than or equal to the number of tab coupling portions 32, as in the embodiment of the present invention, the coupling force between the housing coupling portion 33 and the battery housing 20 is weakened. For example, the current collector 30 can be detached from the inner surface of the battery housing 20. In particular, the contact portions 33a can be detached from the upper surface of the beading portion 21 in the direction of the arrow shown in FIG. 15. This allows the current collector 30 to be more easily deformed upward when the battery cell 1 is vented. That is, the upward movement distance of the current collector 30 can be further increased when the battery cell 1 is vented.

[0109] FIG. 17 is a diagram illustrating a battery cell 1 according to another embodiment of the present invention, and FIG. 18 is a diagram illustrating a battery cell 1 according to yet another embodiment of the present invention.

[0110] 17, in yet another embodiment of the present invention, the battery cell 1 may include an insulator S interposed between the beading portion 21 and the electrode assembly 10. The insulator S may include a material having insulating properties. The insulator S may have, for example, a tape or sheet shape.

[0111] In this way, a structure in which the insulator S having insulating properties is interposed between the beading portion 21 and the electrode assembly 10 can prevent a phenomenon in which a residual contact portion 33a is generated and fusing is not performed properly even after the current collector 30 is detached. That is, by interposing the insulator S between the beading portion 21 and the electrode assembly 10 as shown in FIG. 17, it is possible to prevent a current path from being formed.

[0112] Preferably, the insulator S may have a shape that is matched with the inner surface of the beading portion 21 .

[0113] For example, referring to FIG. 18 , the insulator S may have a shape in which it is bent upward and extends toward the beading portion 21. This structure can reliably block contact between the first non-coating portion 11 and the battery housing 20. That is, as shown in FIG. 18 , as the current collector 30 moves upward due to the pressure of the vent gas, the first non-coating portion 11, which was welded to the current collector 30, may also be deformed and bent upward. This increases the likelihood that the bent first non-coating portion 11 will come into contact with the inner surface of the battery housing 20. In particular, because the beading portion 21 has a recessed structure on the inside of the battery housing 20, the probability of contact with the bent first non-coating portion 11 increases. That is, a current path may be formed due to contact between the first non-coating portion 11 and the battery housing 20. However, in the embodiment of the present invention, the insulator S has a shape that matches the inner surface of the beading portion 21, so that the insulator S encases the inner surface of the beading portion 21, preventing the first uncoated portion 11 from coming into contact with the beading portion 21. In other words, the formation of a current path can be firmly blocked.

[0114] 1 to 3, the housing cover 40 covers the opening formed on one side of the battery housing 20. The housing cover 40 may be fixed by a clamping portion 22 formed on the upper end of the battery housing 20. In this case, to improve fixing strength and sealing performance of the battery housing 20, a seal gasket G1 may be interposed between the battery housing 20 and the housing cover 40 and between the current collector 30 and the housing cover 40. In this case, the contact portion 33a and / or the second contact portion may be interposed between the beading portion 21 of the battery housing 20 and the seal gasket G1. In this manner, the contact portion 33a and / or the second contact portion interposed between the beading portion 21 and the seal gasket G1 may be fixed by bending the clamping portion 22 extending upward from the beading portion 21.

[0115] Referring to FIG. 3 , the terminal 50 penetrates the battery housing 20 from the opposite side of the open portion thereof to be electrically connected to the second uncoated portion 12 of the electrode assembly 10. The terminal 50 may penetrate approximately the center of the bottom surface of the battery housing 20. The terminal 50 may be electrically connected to the electrode assembly 10, for example, by being coupled to a second current collector 60 coupled to the second uncoated portion 12 or by being coupled to a lead tab (not shown) coupled to the second uncoated portion 12. Therefore, the terminal 50 has the same polarity as the second electrode of the electrode assembly 10 and can function as a second electrode terminal T2. When the second uncoated portion 12 is a positive electrode tab, the terminal 50 can function as a positive electrode terminal.

[0116] Considering the polarity and function of the terminal 50, the terminal 50 must be insulated from the battery housing 20, which has the opposite polarity. For this purpose, an insulating gasket G2 may be used between the terminal 50 and the battery housing 20. Alternatively, insulation may be achieved by coating part of the surface of the terminal 50 with an insulating material.

[0117] For the same reason, the second uncoated portion 12 and / or the second current collector 60 must be insulated from the battery housing 20. For this reason, an insulator 70 may be interposed between the second uncoated portion 12 and the battery housing 20 and / or between the second current collector 60 and the battery housing 20. When the insulator 70 is used, the terminal 50 may penetrate the insulator 70 to electrically connect with the second uncoated portion 12.

[0118] Meanwhile, in an embodiment of the present invention, the outer surface 20a of the closed portion located opposite the open portion provided at the upper end of the battery housing 20 may function as the first electrode terminal T1. If the first uncoated portion 11 is a negative electrode tab, the first electrode terminal T1 may be a negative electrode terminal. The battery cell 1 according to an embodiment of the present invention has a structure in which the terminal 50 exposed on the lower surface located opposite the open portion of the battery housing 20 can be used as the second electrode terminal T2, and the remaining area of the lower surface of the battery housing 20 excluding the area occupied by the terminal 50 (including the area where the insulating gasket G2 is exposed, if the insulating gasket G2 is exposed outside the terminal 50 on the outer surface 20a of the closed portion) can be used as the first electrode terminal T1. Therefore, the battery cell 1 according to an embodiment of the present invention can connect both the positive and negative electrodes in one direction when electrically connecting multiple battery cells 1, thereby simplifying the electrical connection structure. In addition, the battery cell 1 according to the embodiment of the present invention has a structure in which most of the bottom surface located opposite the open portion of the battery housing 20 can be used as an electrode terminal, which has the advantage of ensuring a sufficient area for welding components for electrical connection.

[0119] 2 and 3, the second current collector 60 is coupled to the lower part of the electrode assembly 10. The second current collector 60 is made of a conductive metal material and is electrically coupled to the second uncoated portion 12.

[0120] 19, a battery pack 3 according to one embodiment of the present invention includes a battery assembly in which a plurality of battery cells 1 according to one embodiment of the present invention are electrically connected as described above, and a pack housing 2 that accommodates the battery assembly. For ease of illustration, components such as bus bars for electrical connections, a cooling unit, and power terminals are omitted from the drawings of the present application.

[0121] 20, an automobile 5 according to an embodiment of the present invention may be, for example, an electric automobile, a hybrid automobile, or a plug-in hybrid automobile, and includes a battery pack 3 according to an embodiment of the present invention. The automobile 5 includes a four-wheeled automobile and a two-wheeled automobile. The automobile 5 operates by receiving a supply of power from the battery pack 3 according to an embodiment of the present invention.

[0122] Although the present invention has been described above using limited embodiments and drawings, the present invention is not limited to these, and it goes without saying that various modifications and variations can be made by a person having ordinary knowledge in the technical field to which the present invention pertains within the technical spirit of the present invention and the scope of equivalents of the claims. [Explanation of symbols]

[0123] 5. Automobiles 3 Battery Pack 2-pack housing 1 battery cell 10 Electrode assembly 11 First plain area 12 Second plain area H1 Winding hole 20 Battery housing 20a Outer surface of closure T1 First electrode terminal 21 Beading section 22 Clamping part 30 Current collector (first current collector) H2 collector hole 31 Support part 32 Tab joint H3 liquid injection hole 33 Housing joint 33a Contact part 33b Connection NL fractured part 40 Housing cover 41 Vent G1 seal gasket S insulator 50 terminals T2 Second electrode terminal G2 Insulation Gasket 60 Second current collector N Current interruption section 70 Insulator

Claims

1. An electrode assembly in which a first electrode, a second electrode, and a separator sandwiched therebetween are wound around a winding shaft to define a core and an outer peripheral surface, the first electrode including a first uncoated portion that is not coated with an active material layer along the winding direction; a battery housing having an opening on one side thereof and accommodating the electrode assembly through the opening; a current collector including a support portion disposed on an upper portion of the electrode assembly; a tab connection portion extending from the support portion and connected to the first plain portion; and a housing connection portion extending from the support portion and electrically connected to an inner surface of the battery housing, the housing connection portion including at least one weld portion connected to the inner surface of the battery housing by welding; a housing cover that covers the opening; Including, A battery cell, wherein the number of the welds is less than or equal to the number of the tab connections, or wherein a break is provided at the boundary between the support portion and the housing connection portion so that the boundary is weaker than the surrounding area.

2. The battery cell of claim 1 , wherein the number of the housing joints is smaller than the number of the tab joints.

3. The housing coupling portion is contacts coupled onto an inner surface of the battery housing; a connection portion that connects the support portion and the contact portion; 10. The battery cell of claim 1, comprising:

4. The battery cell according to claim 3 , wherein the connection portion and the contact portion have the same width along an extension direction.

5. The breaking portion is The battery cell according to claim 1 , wherein the battery cell has a shape of a notch molding line including a plurality of notches.

6. The battery cell according to claim 1 , wherein a break portion is provided at a boundary between the support portion and the tab connection portion, the break portion being configured to have a strength lower than that of a surrounding region.

7. The housing coupling portion is The battery cell of claim 1 , wherein the battery cell is configured so that its length is extensible.

8. At least a portion of the housing coupling portion is 5. The battery cell according to claim 1, wherein the battery cell has a rim shape with a hollow center.

9. The housing cover is 5. The battery cell of claim 1, further comprising a vent configured to rupture if pressure inside the battery housing increases above a certain level.

10. The radial length of the vent portion is The battery cell according to claim 9 , wherein the radial length is greater than the radial length of the support portion.

11. The battery housing comprises: The battery cell according to claim 1 , further comprising a beading portion formed at an end adjacent to the opening and pressed inward.

12. The battery cell The battery cell according to claim 11 , further comprising an insulator interposed between the beading portion and the electrode assembly.

13. The insulator is The battery cell of claim 12 , having a shape that is aligned with an inner surface of the beading portion.

14. A battery pack comprising at least one battery cell according to any one of claims 1 to 4.

15. A motor vehicle comprising at least one battery pack according to claim 14.

Images