Battery unit, battery pack, and vehicle including same

Abstract

According to one embodiment of the present invention, a battery cell comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed between the first electrode and the second electrode are wound around a winding axis to define a core and an outer peripheral surface, in which the first electrode includes a first uncoated portion not coated with an active material layer in a winding direction; a battery case having an opening on one side thereof and receiving the electrode assembly through the opening; and a current collector including a support portion disposed on an upper portion of the electrode assembly, a tab coupling portion extending from the support portion and coupled to the first uncoated portion, and a case coupling portion extending from the support portion, electrically coupled to an inner surface of the battery case, and configured to be extendable in length.

Description

Technical Field

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

[0002] This application claims priority to Korean Patent Application No. 10-2022-0150570 filed in Korea on November 11, 2022, and Korean Patent Application No. 10-2023-0069484 filed in Korea on May 30, 2023, the disclosures of which are incorporated herein by reference. Background Art

[0003] Secondary batteries, which are easy to apply according to product groups and have electrical properties such as high energy density, are generally used in electric vehicles (EV) or hybrid electric vehicles (HEV) driven by electric drive sources, and portable devices. These secondary batteries have attracted much attention as new energy sources that improve eco-friendliness and energy efficiency because they have the main advantage of being able to significantly reduce the use of fossil fuels and do not produce byproducts due to energy use.

[0004] The types of secondary batteries widely used at present include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, nickel-zinc batteries, etc. The operating voltage of the unit secondary battery cell (i.e., unit battery cell) is about 2.5V to 4.5V. Therefore, when an output voltage higher than this is required, the battery pack can be configured by connecting a plurality of battery cells in series. In addition, depending on the charge / discharge capacity required for the battery pack, the battery pack can be configured by connecting a plurality of battery cells in parallel. Therefore, depending on the required output voltage and / or charge / discharge capacity, the number of battery cells included in the battery pack can be set in various ways.

[0005] In addition, in a current collector configured to electrically connect an electrode assembly to a battery case, a portion disposed on the electrode assembly and a portion disposed on a pressure edge portion of the battery case are different in height from each other, so that the connecting portion connecting them must be configured to have a length greater than a connection distance on a plane or to be elongated.

[0006] For this reason, in the past, the connection portion was applied with, for example, wrinkles formed thereon, but in this case, it is difficult to manufacture the current collector only by processing the plate to keep it flat, so it is also necessary to perform a separate forming process on the processed plate to change the shape three-dimensionally. In addition, as in the above case, if a structure that allows the connection portion to be extended is not applied to the current collector, there is a problem that the connection portion is damaged during the extension.

[0007] Therefore, a new current collector structure is needed to solve this problem. Summary of the invention

[0008] Technical issues

[0009] The present disclosure is designed to solve the problems of the related art, and thus the present disclosure aims to provide a current collector that can be elongated without wrinkling or damage without the assistance of a separate structure.

[0010] On the other hand, the present disclosure aims to enable the manufacture of current collectors simply by machining the plate while maintaining its flat shape.

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

[0012] Technical Solution

[0013] According to the present disclosure, a battery cell is provided, which includes: an electrode assembly, in which a first electrode and a second electrode are wound around a winding axis while a separator is interposed between the first electrode and the second electrode, thereby defining a core portion and an outer peripheral surface, the first electrode including a first uncoated portion that is not coated with an active material layer along a winding direction; a battery case having an opening provided on one side thereof and configured to accommodate the electrode assembly through the opening; and a current collector including a support portion provided on an upper portion of the electrode assembly, a joint connection portion extending from the support portion and connected to the first uncoated portion, and a case connection portion extending from the support portion to be electrically connected to an inner surface of the battery case and configured so that its length can be extended.

[0014] In one aspect of the present disclosure, a boundary between the support portion and the case coupling portion may be bent so that an end of the case coupling portion faces the opening and an inner surface of the battery case.

[0015] In another aspect of the present disclosure, the case coupling portion may extend in a winding axis direction of the electrode assembly as well as in a radial direction thereof.

[0016] In one aspect of the present disclosure, the case coupling portion may include: a contact portion coupled to an inner surface of the battery case; and a connection portion connecting the support portion and the contact portion.

[0017] In another aspect of the present disclosure, the housing coupling portion may be configured such that its length is compressible.

[0018] In another aspect of the present disclosure, at least a portion of the housing coupling portion may have a flange shape having a hollow center.

[0019] For example, at least a portion of the housing coupling portion may have an elliptical planar shape.

[0020] In another embodiment of the present disclosure, at least a portion of the housing coupling portion may have a polygonal planar shape.

[0021] In another aspect of the present disclosure, an outer edge of the connection portion may have at least one notch, and the at least one notch is configured to be recessed toward an interior of the connection portion.

[0022] In another aspect of the present disclosure, the connecting portion may have at least one bent portion.

[0023] Preferably, the bent portion may have a convex shape in a direction toward the opening.

[0024] In another aspect of the present disclosure, the contact portion may have a continuous shape along the inner surface of the battery case.

[0025] Furthermore, the present disclosure provides a battery pack including at least one battery cell according to the above-described embodiments.

[0026] Furthermore, the present disclosure provides a vehicle including at least one battery pack according to the above-described embodiments.

[0027] Technical Effects

[0028] According to the present disclosure, the current collector can be effectively elongated.

[0029] More specifically, according to the present disclosure, even without a separate structure, wrinkles or damage do not occur when the current collector is elongated.

[0030] On the other hand, according to the present disclosure, a current collector can be manufactured only by processing a plate while maintaining a flat shape of the plate.

[0031] However, the effects obtainable according to the present disclosure are not limited to the above-mentioned effects, and other technical effects not mentioned above will be clearly understood by those skilled in the art from the description of the present disclosure described below. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the detailed description of the present invention, are used to provide further understanding of the technical concept of the present disclosure, and therefore, the present disclosure should not be construed as being limited to the accompanying drawings.

[0033] Figure 1 is a schematic diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0034] Figure 2 yes Figure 1 Longitudinal cross-sectional view of .

[0035] Figure 3 yes Figure 1 Longitudinal cross-sectional view of a battery cell in FIG.

[0036] Figure 4is a diagram illustrating a current collector according to an embodiment of the present disclosure.

[0037] Figure 5 It is an example Figure 4 A diagram showing a state in which the current collector is stretched.

[0038] Figure 6 is along Figure 4 A cross-sectional view of the current collector taken in FIG.

[0039] Figure 7 is a diagram illustrating a case coupling portion of a current collector according to an embodiment of the present disclosure.

[0040] Figure 8 It is an example Figure 7 A diagram showing the process in which the shell connecting part is elongated.

[0041] Fig. 9 is a diagram illustrating a current collector according to another embodiment of the present disclosure.

[0042] Fig.10 is a diagram illustrating a current collector according to another embodiment of the present disclosure.

[0043] Fig.11 is a diagram illustrating a current collector according to another embodiment of the present disclosure.

[0044] Fig.12 is a diagram illustrating a current collector according to another embodiment of the present disclosure.

[0045] Fig.13 It is an example Fig.12 A diagram showing a state in which the current collector is stretched.

[0046] Fig.14 is a diagram illustrating a battery pack including a battery cell according to an embodiment of the present disclosure.

[0047] Fig.15 It is an example including Fig.14 Diagram of a battery pack in a vehicle. DETAILED DESCRIPTION

[0048] Hereinafter, the preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before the description, it should be understood that the terms used in the specification and the appended claims should not be interpreted as limited to the general and dictionary meanings, but should be interpreted based on the meanings and concepts corresponding to the technical aspects of the present disclosure on the basis of the principle that the inventor is allowed to appropriately define the terms for the best interpretation. Therefore, the configurations proposed in the embodiments of this specification and the accompanying drawings only represent the most preferred embodiments of the present disclosure, and do not represent all technical concepts of the present disclosure, so it should be understood that various equivalents and modifications may be made to them when filing an application.

[0049] Furthermore, to aid understanding of the present disclosure, the drawings are not drawn to scale and the sizes of some elements may be exaggerated. In addition, the same reference numerals may represent the same components between different embodiments.

[0050] Referring to two objects being compared as being the same means that they are "substantially the same." Thus, "substantially the same" can include situations where the deviation is considered low in the art (e.g., less than 5%). In addition, a parameter that is uniform in a region can mean that it is uniform from an average perspective.

[0051] Although "first", "second", etc. are used to describe various elements, these elements are not limited to these terms. These terms are only used to distinguish one element from another element, and unless otherwise mentioned, the first element may also be the second element.

[0052] Throughout the specification, unless otherwise mentioned, various elements may include a single element or a plurality of elements.

[0053] The configuration of setting an element "in the upper part (or lower part)" or "at the top (or bottom)" of a target element may mean that the element may be set to contact the upper surface (or lower surface) of the target element, and another element may be inserted between the target element and the element set on the top (or bottom) of the target element.

[0054] Furthermore, the expression “an element is ‘connected’, ‘coupled’ or ‘fastened’ to another element” should be understood that the elements may be directly connected or fastened to each other, another element may be “interposed” between the elements, or the elements may be “connected”, “coupled” or “fastened” through other elements.

[0055] Throughout the specification, unless otherwise mentioned, “A and / or B” may mean A or B, or A and B, and “C to D” may mean “equal to or greater than C and equal to or less than D” unless otherwise mentioned.

[0056] For the sake of convenience, in this specification, the longitudinal direction of the winding axis of the electrode assembly 10 wound in a winding core shape is referred to as the "axial direction (Y)". In addition, the direction around the winding axis is referred to as the "circumferential direction (X)". In addition, the direction close to or away from the winding axis is referred to as the "radial direction". Among them, the direction close to the winding axis is referred to as the "centripetal direction", and the direction away from the winding axis is referred to as the "centrifugal direction".

[0057] Figure 1 is a diagram illustrating a battery cell 1 according to an embodiment of the present disclosure, and Figure 2 yes Figure 1 Longitudinal cross-sectional view of the . Figure 3yes Figure 1 A longitudinal cross-sectional view of a battery cell 1 in FIG.

[0058] Reference Figure 1 The battery cell 1 according to the embodiment of the present disclosure includes an electrode assembly 10, a battery case 20, and a current collector 30. The battery cell 1 may further include a case cover 40. The present disclosure is not limited to a specific type of battery and may be applied to other types of batteries (such as square batteries).

[0059] The electrode assembly 10 includes a first uncoated portion 11 and a second uncoated portion 12. More specifically, the electrode assembly 10 has a structure in which the first electrode and the second electrode are wound around a winding axis while a separator is interposed between the first electrode and the second electrode, thereby defining a core and a peripheral surface. That is, the electrode assembly 10 applied to the present disclosure may be a core-wound electrode assembly 10. In this case, an additional separator may be provided on the peripheral surface of the electrode assembly 10 to insulate it from the battery case 20. The electrode assembly 10 may have a winding structure known in the art without limitation.

[0060] The first electrode includes a first electrode current collector and a first electrode active material coated on one side or both sides of the first electrode current collector. Figure 1 An uncoated portion not coated with the first electrode active material is provided at one end of the battery cell 1 (in a direction parallel to the height direction of the battery cell 1 shown). That is, the first electrode includes an uncoated portion that is not coated with the active material at the end of its long side along the winding direction and is exposed to the outside of the separator. Hereinafter, the uncoated portion used as the first electrode tab will be referred to as the first uncoated portion 11. The first uncoated portion 11 is provided at the electrode assembly 10 accommodated in the battery case 20 in the height direction (in a direction parallel to the height direction of the battery cell 1 shown). Figure 1 The first electrode 1 is formed by a first uncoated portion 11, which is not coated with an active material at the end of the long side and is exposed to the outside of the separator, and at least a portion of the first uncoated portion 11 itself serves as an electrode terminal. The first uncoated portion 11 can be, for example, a negative electrode terminal.

[0061] In addition, at least a portion of the first non-coating portion 11 may include a plurality of sections divided along the winding direction of the electrode assembly 10. In this case, the plurality of sections may be bent in the radial direction of the electrode assembly 10.

[0062] Reference Figure 2 and Figure 3, multiple bending sections of the first uncoated portion 11 may overlap in multiple layers to form a bending surface. In this case, the joint connection portion 32 (described later) of the current collector 30 may be connected to the bending surface. The joint connection portion 32 may be connected to an area where multiple sections overlap in multiple layers. In this case, the joint connection portion 32 may be placed on the bending surface of the first uncoated portion 11, and then welding may be performed on a certain area thereof. That is, the joint connection portion 32 may be connected to an area where multiple sections of the first uncoated portion 11 overlap in multiple layers. For example, as Figure 5 As shown, the joint coupling portion 32 may have at least one welding portion that is welded to a certain area while being seated on the bent surface of the first non-coating portion 11 .

[0063] The second electrode includes a second electrode current collector and a second electrode active material coated on one side or both sides of the second electrode current collector. Figure 1 At the other end of the battery cell 1 shown in the figure (in a direction parallel to the height direction of the battery cell 1), an uncoated portion not coated with the second electrode active material is provided. That is, the second electrode includes an uncoated portion, which is not coated with an active material at the end of the long side along the winding direction and is exposed to the outside of the diaphragm. Hereinafter, the uncoated portion used as the second electrode connector will be referred to as the second uncoated portion 12. The second uncoated portion 12 is provided at the bottom of the electrode assembly 10 accommodated in the battery case 20 in its height direction. That is, the second electrode includes a second uncoated portion 12, which is not coated with an active material at the end of the long side and is exposed to the outside of the diaphragm, and at least a portion of the second uncoated portion 12 itself is used as an electrode connector. The second uncoated portion 12 can be, for example, a positive electrode connector.

[0064] Furthermore, in the present disclosure, any active material known in the art may be used as a positive electrode active material coated on a positive electrode plate and a negative electrode active material coated on a negative electrode plate without limitation.

[0065] Reference Figure 1 The battery case 20 is a substantially cylindrical container having an opening formed on one side thereof, and is made of a conductive metal material. Typically, the side surface of the battery case 20 and the bottom surface opposite to the opening are formed integrally. That is, the battery case 20 is typically configured so that the top in the height direction is open and the bottom is closed. The bottom surface of the battery case 20 may be configured in a substantially flat shape. The battery case 20 receives the electrode assembly 10 through an opening formed on one side in the height direction. The battery case 20 may also receive an electrolyte through the opening.

[0066] The battery case 20 may have a press-edge portion 21 formed at an end adjacent to an opening provided at the top of the battery case 20. The battery case 20 may further include a curling portion 22 formed on the press-edge portion 21. The press-edge portion 21 may be configured so that the outer peripheral surface of the battery case 20 is press-fitted to a predetermined depth. More specifically, the press-edge portion 21 may be configured to be press-fitted inwardly in a region between an opening formed on one side of the battery case 20 and a receiving portion that receives the electrode assembly 10.

[0067] The beading portion 21 is formed above the electrode assembly 10. The inner diameter of the battery case 20 in the region where the beading portion 21 is formed is smaller than the diameter of the electrode assembly 10. At least one joint coupling portion 32 of the current collector 30 to be described later may be positioned lower than the beading portion 21.

[0068] The edge pressing portion 21 provides a support surface on which the case cover 40 is placed. In addition, the edge pressing portion 21 can provide a support surface on which at least a portion of the edge of the current collector 30 to be described later is placed and connected. That is, at least a portion of the edge of the current collector 30 and / or the edge of the case cover 40 of the present disclosure can be placed on the upper surface of the edge pressing portion 21. In order to stably support at least a portion of the edge of the current collector 30 and / or the edge of the case cover 40, the upper surface of the edge pressing portion 21 can be configured to extend in a direction substantially parallel to the bottom surface of the battery case 20, that is, in a direction substantially perpendicular to the side wall of the battery case 20.

[0069] The edge clamping portion 21 may prevent the electrode assembly 10 (whose size roughly corresponds to the inner diameter of the battery case 20) from escaping through the opening formed at the top of the battery case 20, and serves as a support portion on which the case cover 40 is placed. The upper edge clamping portion 21 may function as a support portion for fixing the contact portion 33a of the current collector 30 and the sealing gasket G1 and the case cover 40.

[0070] The beading portion 22 is formed on the top of the beading portion 21. The beading portion 22 is configured to extend and bend to surround the edge of the housing cover 40 disposed above the beading portion 21. Such a configuration of the beading portion 22 can fix the housing cover 40 to the beading portion 21.

[0071] First, refer to Figure 1 and Figure 2 The current collector 30 according to an embodiment of the present disclosure is accommodated inside the battery case 20 and is electrically connected to the electrode assembly 10 and the battery case 20. That is, the current collector 30 electrically connects the electrode assembly 10 and the battery case 20.

[0072] Figure 4 is a diagram illustrating a current collector 30 according to an embodiment of the present disclosure.

[0073] Reference Figure 4 The current collector 30 includes a support portion 31 located on one surface of the electrode assembly 10 , a joint coupling portion 32 extending from the support portion 31 and coupled to the first uncoated portion 11 , and a case coupling portion 33 extending from the support portion 31 and coupled to the inner surface of the battery case 20 .

[0074] The joint coupling portion 32 and the case coupling portion 33 are indirectly connected to each other through the support portion 31, rather than being directly connected to each other. Therefore, when an external impact is applied to the battery cell 1 of the present disclosure, the possibility of damage to the coupling portion between the current collector 30 and the electrode assembly 10 and the coupling portion between the current collector 30 and the battery case 20 can be minimized.

[0075] Reference Figure 4 , at least one joint connection portion 32 and / or at least one shell connection portion 33 may be provided. At least one joint connection portion 32 and at least one shell connection portion 33 may be provided, for example, in a substantially radial shape, a cross shape, or a combination thereof relative to the center of the current collector 30. On the other hand, the corresponding shell connection portion 33 may be provided between adjacent joint connection portions 32.

[0076] Reference Figure 3 , a support portion 31 and a plurality of joint connection portions 32 are disposed at the top of the electrode assembly 10. The joint connection portion 32 is connected to the first uncoated portion 11 of the electrode assembly 10. The joint connection portion 32 may be connected to the first uncoated portion 11 in the radial direction of the electrode assembly 10 by, for example, welding. For example, the joint connection portion 32 may be welded to the first uncoated portion 11 so as to be substantially parallel to the bottom surface of the battery case 20. The welded portion formed between the first uncoated portion 11 and the joint connection portion 32 may form a straight line welding pattern extending substantially in, for example, the radial direction of the electrode assembly 10.

[0077] In addition, the support portion 31 and the joint connection portion 32 may also be connected to the first uncoated portion 11. The joint connection portion 32 and the first uncoated portion 11 may be connected by welding. In the case where the edge pressing portion 21 is formed in the battery case 20, the support portion 31 and the joint connection portion 32 are positioned lower than the edge pressing portion 21.

[0078] The support portion 31 may include a current collector hole H2 formed at a position corresponding to the winding hole H1 formed approximately at the center of the electrode assembly 10. The winding hole H1 and the current collector hole H2, which are connected to each other, may be used as a channel for welding rod insertion or laser beam irradiation for welding between the terminal 50 and the second current collector 30 or for welding between the terminal and the lead tab (not shown). The diameter of the current collector hole H2 is substantially equal to or greater than the diameter of the winding hole H1 of the electrode assembly 10 so as not to cover the winding hole H1 formed in the core of the electrode assembly 10. If the diameter of the current collector hole H2 is much smaller than the diameter of the winding hole H1, the winding hole H1 may be blocked, thereby reducing the liquid injection performance, and it is difficult to ensure sufficient space to insert a welding device or irradiate a laser beam.

[0079] The plurality of joint coupling portions 32 may extend substantially radially from the support portion 31 of the current collector 30 toward the sidewall of the battery case 20. The respective joint coupling portions 32 may be positioned to be spaced apart from each other along the circumferential direction of the support portion 31.

[0080] A plurality of case coupling portions 33 may extend substantially radially from the support portion 31 of the current collector 30 toward the sidewall of the battery case 20. The respective case coupling portions 33 may be positioned to be spaced apart from each other along the circumference of the support portion 31. At least one case coupling portion 33 may be located between adjacent joint coupling portions 32.

[0081] The housing coupling portion 33 may extend from the support portion 31 to be electrically coupled to the inner surface of the battery housing 20. For example, the housing coupling portion 33 may be coupled to, for example, the edge holding portion 21 on the inner surface of the battery housing 20. In particular, the housing coupling portion 33 may be coupled to the upper surface of the edge holding portion 21.

[0082] In one aspect of the present disclosure, the housing coupling portion 33 can be configured such that its length can be extended. This will be described below with reference to Figure 4 and Figure 5 Describe in detail.

[0083] Figure 4 is a diagram illustrating a current collector 30 according to an embodiment of the present disclosure, and Figure 5 It is an example Figure 4 FIG. 4 is a diagram showing a state in which the current collector 30 is stretched.

[0084] Reference Figure 4 and Figure 5 , the housing coupling portion 33 may be configured to be elongated in length. That is, the housing coupling portion 33 may be configured such that the length of the housing coupling portion 33 when the housing coupling portion 33 is elongated is greater than its length when the housing coupling portion 33 is not elongated. For example, Figure 4The shape of the current collector 30 before being elongated is shown. Figure 4 The current collector 30 in the embodiment can be made of a flat plate. That is, when manufacturing the current collector 30, the flat plate can be cut and processed to produce Figure 4 The current collector 30 shown. Figure 5 As shown, the current collector 30 may be elongated before or while being assembled into a battery cell.

[0085] That is, according to the present disclosure, the current collector 30 configured as a single flat plate can be easily extended without a separate structure. More specifically, according to this structure, even without a separate structure, no wrinkles or damage will occur when the current collector 30 is extended. In other words, the current collector 30 configured as a single plate can be extended without wrinkles or damage. In addition, according to the present disclosure, even if the current collector 30 is only manufactured in a flat plate form without an additional process, wrinkles or damage can be prevented when the current collector 30 is extended. In particular, in the case of forming a separate wrinkle in the connecting portion 33b in order to extend the connecting portion 33b of the conventional current collector 30, the risk of the connecting portion 33b becoming vulnerable to damage according to the wrinkle formation direction can be reduced. In addition, there are no wrinkles or separate structures in the current collector 30, thereby facilitating the flow of current. In addition, according to the present disclosure, the production cost in the production process of the current collector 30 can be reduced and the production process can be simplified. In particular, according to the present disclosure, the separate wrinkles provided in the conventional connecting portion 33b for extending the connecting portion 33b can be omitted.

[0086] In another aspect of the present disclosure, a boundary between the support portion 31 and the case coupling portion 33 may be configured to be bent such that an end of the case coupling portion 33 faces the opening and the inner surface of the battery case 20 .

[0087] For example, refer to Figure 3 and Figure 5 , the housing coupling portion 33 is bent in a direction toward the top of the battery cell. That is, the current collector 30 manufactured as a flat plate may be bent and deformed in some portions thereof and then assembled inside the battery cell. In particular, the boundary between the support portion 31 and the housing coupling portion 33 may be bent, and in this case, the boundary may be bent so that the end of the housing coupling portion 33 faces the opening.

[0088] Preferably, the case coupling portion 33 may be configured to extend in a winding axis direction and a radial direction of the electrode assembly 10 .

[0089] Reference Figure 2 and Figure 3 The case coupling portion 33 may extend upward from the winding axis of the electrode assembly 10 to be inclined. As a result, in order to transform the current collector 30 from the flat plate state when it is initially manufactured to the state as Figure 5 In the state shown in which the housing coupling portion 33 extends upward, the support portion 31 and the housing coupling portion 33 must be bent upward at the boundary therebetween, and as a result, the current collector 30 can be formed to have a predetermined height in the vertical direction. That is, the current collector 30 has a predetermined total height, in which case the total height can be configured to vary within a predetermined range.

[0090] Reference Figures 3 to 5 The case coupling portion 33 includes a contact portion 33 a coupled to the inner surface of the battery case 20 , and a connection portion 33 b connecting the support portion 31 and the contact portion 33 a .

[0091] The contact portion 33a is coupled to the inner surface of the battery case 20. In the case where the edge pressing portion 21 is formed in the battery case 20, the contact portion 33a may be coupled to the edge pressing portion 21. In this case, for stable contact and coupling, both the edge pressing portion 21 and the contact portion 33a may be configured to extend in a direction substantially parallel to the bottom surface of the battery case 20, that is, in a direction substantially perpendicular to the side wall of the battery case 20.

[0092] In addition, the contact portion 33a may be welded to the upper surface of the edge pressing portion 21. That is, the welding portion may be formed on the upper surface area of ​​the edge pressing portion 21. The welding portion formed between the contact portion 33a and the edge pressing portion 21 may be formed to be narrower than the upper surface of the edge pressing portion 21. For example, laser welding, ultrasonic welding, or spot welding may be applied as welding between the battery case 20 and the current collector 30.

[0093] Figure 6 is along Figure 4 A is a cross-sectional view of the current collector 30 shown in FIG.

[0094] Reference Figure 6 , the housing coupling portion 33 may be configured such that its length may be compressed.

[0095] The current collector 30 is manufactured by cutting and processing the flat plate as described above. That is, when initially manufactured, the current collector 30 is in a flat plate state. This state will be defined as the first state S1. For example, the current collector 30 according to an embodiment of the present disclosure may have a total height of 0 mm in the first state S1 (the distance between the upper surface of the contact portion 33a and the upper surface of the support portion 31 in the extension direction of the winding axis, or the distance between the upper surface of the contact portion 33a and the upper surface of the joint connection portion 32 in the extension direction of the winding axis). In addition, as will be described in detail later, the shell connection portion 33 may have a flange shape with an empty center. For example, the shell connection portion 33 may have an elliptical shape with a major axis L and a minor axis S. As an example, in the first state S1, the major axis L of the ellipse may be about 10 mm, and its minor axis S may be about 6 mm.

[0096] In addition, in order for the current collector 30 to function as a component, a certain area of ​​the current collector 30 must be in a bent state. For example, as described above, since the current collector 30 electrically connects the electrode assembly 10 and the battery case 20, if there is a height difference between the connection surface of the battery case 20 and the current collector 30 and the connection surface of the electrode assembly 10 and the current collector 30, the current collector 30 must be shaped to match the height difference. Specifically, referring to Figure 3 and Figure 5 , the boundary between the support portion 31 of the current collector 30 and the shell connection portion 33 must be in an upwardly bent state. This state in which the current collector 30 is deformed to bend and has not yet been assembled into the battery cell will be defined as the second state S2. The current collector 30 in the second state S2 can eventually be received inside the battery case 20 to be assembled into the battery cell. At this time, the overall height of the current collector 30 can be configured to be greater than or equal to the axial distance between the upper surface of the electrode assembly 10 and the upper surface of the edge pressing portion 21 (the distance along the extension direction of the winding axis of the electrode assembly 10). If the total height of the current collector 30 is less than the axial distance between the upper surface of the electrode assembly 10 and the upper surface of the edge pressing portion 21, the contact portion 33a of the current collector 30 may interfere with the edge pressing portion 21, so that the support portion 31 and / or the joint connection portion 32 may not contact the electrode assembly 10. Alternatively, if the current collector 30 is preferentially coupled to the electrode assembly 10 and then received inside the battery case 20, the contact portion 33a may interfere with the edge holding portion 21, so that the electrode assembly 10 may not reach the bottom of the battery case 20. As a result, this may create a blank space, thereby reducing energy efficiency. For example, in the second state S2, the total height of the current collector 30 (ie, the height between the support portion 31 and the contact portion 33a in the winding axis direction) can be set to about 5 mm, and in this case, the connecting portion 33b may need to have a structural extension length of about 1.18 mm.

[0097] In addition, as described above, the total height of the current collector 30 is preferably configured to be greater than or equal to the axial distance between the upper surface of the electrode assembly 10 and the upper surface of the edge pressing portion 21. According to this structure, the contact portion 33a of the current collector 30 is positioned higher than the edge pressing portion 21. Here, the connecting portion 33b can be compressed so that the contact portion 33a is in contact with the edge pressing portion 21. At this time, welding can be performed in a state where the contact portion 33a is in contact with the edge pressing portion 21. This state in which the contact portion 33a is in contact with the edge pressing portion 21 will be defined as the third state S3. For example, in the third state S3, the total height of the current collector 30 can be set to about 3.38mm, and in this case, the connecting portion 33b can be compressed to a predetermined length. That is, the connecting portion 33b stretched to a total height of about 5mm can be compressed back to 3.38mm.

[0098] That is, according to the present disclosure, the shell coupling portion 33 can be configured so that its length is extended and / or compressed. Specifically, when changing from the first state S1 to the second state S2, the shell coupling portion 33 can be extended in its length. In addition, when changing from the second state S2 to the third state S3, the shell coupling portion 33 can be compressed in its length. According to the structure in which the shell coupling portion 33 is configured to be extended and compressed in its length, a single design of the current collector 30 can be applied to several battery cells having various sizes and specifications.

[0099] In addition, according to the present disclosure, the current collector 30 configured as a single flat plate can be easily stretched and / or compressed without a separate structure. In addition, according to this structure, even without a separate structure, wrinkles or damage will not occur when stretching and / or compressing the current collector 30. In other words, according to the present disclosure, even if the current collector 30 is manufactured only in the form of a flat plate without further processing, wrinkles or damage can be prevented when the current collector 30 is stretched and / or compressed.

[0100] Figure 7 is a diagram illustrating a case coupling portion 33 of a current collector 30 according to an embodiment of the present disclosure, and Figure 8 It is an example Figure 7 FIG. 3 is a diagram showing a process in which the shell connecting portion 33 is extended.

[0101] According to one aspect of the present disclosure, at least a portion of the housing coupling portion 33 may be configured to have a hollow-center flange shape. In particular, the connection portion 33b of the housing coupling portion 33 may be configured to have a hollow-center flange shape.

[0102] Here, the flange shape includes a circular shape, but is not necessarily limited to a circular shape. For example, the flange shape in the present disclosure may be a polygonal structure such as a triangle or a square, or may represent a specific shape with a curved edge. That is, the flange shape in the present disclosure includes all shapes with a hollow center and continuous edges.

[0103] For example, in an embodiment of the present disclosure, at least a portion of the housing coupling portion 33 may be configured to have an elliptical shape in a plan view, such as Figure 7 and Figure 8 Here, the ellipse includes a circle. In particular, the connecting portion 33b of the housing coupling portion 33 may have an elliptical plane shape. Both the connecting portion 33b before elongation and the connecting portion 33b after elongation may have an elliptical shape. For example, Figure 7 As shown, the connection portion 33b before elongation can be configured to have a substantially elliptical shape. Figure 8 When stretched as shown, the connecting portion 33b can be deformed into another elliptical shape having a longer major axis L and a shorter minor axis S.

[0104] As described above, according to the structure in which at least a portion of the shell connection portion 33 has a shape with a hollow center and continuous edges, even when the shell connection portion 33 having a flat plate shape is stretched and / or compressed, wrinkles and / or damage can be prevented from occurring. In other words, according to the present disclosure, even with a simple manufacturing process, the durability of the current collector 30 can be improved.

[0105] Fig. 9 is a diagram illustrating a current collector 30 according to another embodiment of the present disclosure.

[0106] because Fig. 9 The illustrated current collector 30 is similar to the current collector 30 in the previous embodiment, and thus redundant description of elements substantially the same as or similar to those in the previous embodiment will be omitted, and the following description will be made based on differences from the previous embodiment.

[0107] As another embodiment of the present disclosure, at least a portion of the housing coupling portion 33 may be configured to have a polygonal planar shape. In particular, the connecting portion 33b may be configured to have a polygonal planar shape.

[0108] For example, refer to Fig. 9 , the connecting portion 33b may have a rhombus-shaped planar shape. However, the shape of the connecting portion 33b of the present disclosure is not limited to the rhombus shape, and may include all polygonal shapes such as triangles, squares, and pentagons. That is, the connecting portion 33b of the present disclosure may include all shapes of polygonal shapes with a hollow center and continuous edges.

[0109] Fig.10 is a diagram illustrating a current collector 30 according to another embodiment of the present disclosure.

[0110] because Fig.10 The illustrated current collector 30 is similar to the current collector 30 in the previous embodiment, and thus redundant description of elements substantially the same as or similar to those in the previous embodiment will be omitted, and the following description will be made based on differences from the previous embodiment.

[0111] As another embodiment of the present disclosure, the outer edge of the connection portion 33 b may have at least one notch N formed to be recessed toward the inside of the connection portion 33 b.

[0112] Reference Fig.10 , the connection portion 33b may be configured to have an approximately elliptical shape, and a plurality of notches N may be provided on the outer edge of the ellipse. In order to make the connection portion 33b having an elliptical shape elongate in the direction of the major axis L, the length of the outer edge of the connection portion 33b must be reduced, while the length of the inner edge is increased. In this regard, the current collector 30 may be made of metal to ensure conductivity, but the shape of the high-strength metal may not be easily deformed.

[0113] However, according to the present disclosure, since the connection portion 33b has the notches N recessed toward the inside of the connection portion 33b on its outer edge, when the connection portion 33b is elongated, the areas between the notches N can become close to each other. Therefore, the circumference of the outer edge of the connection portion 33b can be easily reduced.

[0114] according to Figures 4 to 10 In the embodiment of FIG. 1 , when the current collector 30 is assembled to the battery cell 1, the connection portion 33b can be easily extended. That is, the current collector 30 made of a single plate can be extended without wrinkles or damage without the assistance of a separate structure. Specifically, referring to Figure 3 , the support portion 31 of the current collector 30 is in a state where it is spaced apart from the contact portion 33a of the case coupling portion 33 of the current collector 30 by a predetermined distance in the direction of the central axis of the battery cell 1. To this end, Figure 4 The flat-shaped current collector 30 shown must be deformed while being elongated in the vertical direction. For example, the boundary between the support portion 31 and the connection portion 33b and the boundary between the connection portion 33b and the contact portion 33a may be bent, respectively. At this time, in order to keep the radial length from the center of the current collector 30 to the end of the case connection portion 33 constant, the length of the connection portion 33b must be increased. Therefore, when the case connection portion 33 is as Figure 5When bent as shown, the shape of the connecting portion 33b is deformed, so that the housing coupling portion 33 can be easily extended along its extending direction. At the same time, the occurrence of wrinkles and / or damage during the extension process can be suppressed.

[0115] Fig.11 is a diagram illustrating a current collector 30 according to another embodiment of the present disclosure.

[0116] In one aspect of the present disclosure, the connection portion 33b may include at least one bent portion F. Preferably, the bent portion F may have a convex shape in a direction toward the opening.

[0117] Reference Fig.11 , the bent portion F may be located above an imaginary plane that passes through the center of an imaginary straight line connecting one end of the contact portion 33a and one end of the joint coupling portion 32 and is parallel to the bottom plate of the battery case 20. At least one bent portion F may be bent at an obtuse angle so that the current collectors 30 do not overlap each other when viewed from the longitudinal axis of the battery case 20. As another embodiment, the connecting portion 33b may include a plurality of bent portions F. In this case, the boundary between the contact portion 33a and the connecting portion 33b may be bent at an obtuse angle. That is, the inclination of the connecting portion 33b may gradually decrease as the connecting portion 33b becomes closer to the edge pressing portion 21.

[0118] The shell coupling portion 33 according to the present disclosure has the structure of the bent portion F as described above, which can further improve the variability of the overall height of the current collector 30. In other words, the bent portion F can further improve the ability of the current collector 30 to be stretched or compressed in the vertical direction. In addition, the stress applied to the current collector 30 can be effectively dispersed in the subsequent battery sizing process.

[0119] In another aspect of the present disclosure, the contact portion 33 a may be configured to have a continuous shape along the inner surface of the battery case 20 .

[0120] In order to maximize the contact area, the current collector 30 may be configured such that the sum of the circumferential extension lengths of the respective contact portions 33a of the plurality of case coupling portions 33 is substantially equal to or slightly less than the inner circumference of the battery case 20. In particular, as Figure 4 and Figure 5As shown, the contact portion 33a can be configured to have a continuous shape along the inner surface of the battery case 20. That is, the contact portion 33a can have an annular shape extending along the inner surface of the battery case 20. However, in the case where the contact portion 33a is configured as a ring as described above, when the current collector 30 is deformed in the longitudinal direction of the battery cell, the connecting portion 33b must be elongated in the longitudinal direction to maintain the shape of the contact portion 33a. Therefore, at least a portion of the housing coupling portion 33 can be configured to be elongated as described in the present disclosure, thereby maintaining a constant shape of the contact portion 33a.

[0121] In addition, according to the structure in which the contact portion 33a is configured as a continuous shape along the inner surface of the battery case 20, the contact area between the current collector 30 and the battery case 20 can be maximized. Therefore, the bonding force between the current collector 30 and the battery case 20 can be increased. In addition, the internal resistance of the battery can be reduced.

[0122] On the other hand, since the contact portion 33a is interposed between the edge pressing portion 21 and the sealing gasket G1, according to the above structure, the distance between the edge pressing portion 21 and the sealing gasket G1 can be kept constant. Therefore, during the crimping process, the overall uniform compression rate of the sealing gasket G1 can be ensured. Therefore, the risk of electrolyte leakage after the crimping process can be reduced.

[0123] For example, Figure 3 As shown, the sealing gasket G1 can be placed on the edge holding portion 21 and the contact portion 33a, and then the contact portion 33a, the edge holding portion 21 and the sealing gasket G1 can be compressed by the curling portion 22. In this case, if the contact portion 33a is configured to have a predetermined width while extending in two directions from the end of the connecting portion 33b instead of having a continuous shape along the inner surface of the battery case 20, the edge holding portion 21 can have an area in contact with the contact portion 33a and an area in contact with the non-contact portion 33a. That is, there is an area where the contact portion 33a is inserted between the edge holding portion 21 and the sealing gasket G1, and an area where the contact portion 33a is not inserted between the edge holding portion 21 and the sealing gasket G1. In addition, the curling portion 22 is formed by the same compression force in the circumferential direction without change, so that the elements arranged inside the curling portion 22 receive a constant force. Therefore, the compression ratio of the sealing gasket G1 in the region where the contact portion 33a is interposed between the pressure edge portion 21 and the sealing gasket G1 becomes greater than the compression ratio of the sealing gasket G1 in the region where the contact portion 33a is not interposed between the pressure edge portion 21 and the sealing gasket G1. As a result, the compression ratio of the sealing gasket G1 repeats increasing and decreasing alternately along the circumferential direction. Therefore, the sealing performance of the sealing gasket G1 may be deteriorated, thereby increasing the risk of leakage of electrolyte, etc.

[0124] On the other hand, according to the present disclosure, since the contact portion 33a is configured to have a continuous shape along the inner surface of the battery case 20, the contact portion 33a is always interposed between the edge holding portion 21 and the sealing gasket G1. As a result, the compression rate of the sealing gasket G1 can be kept constant in the circumferential direction. Therefore, the sealing performance of the sealing gasket G1 can be enhanced, and the risk of leakage of the electrolyte, etc. can be effectively reduced.

[0125] Fig.12 is a diagram illustrating a current collector 30 according to another embodiment of the present disclosure, and Fig.13 It is an example Fig.12 FIG. 4 is a diagram showing a state in which the current collector 30 is stretched.

[0126] Reference Fig.12 and Fig.13 As another embodiment of the present disclosure, at least a portion of the contact portion 33a may be formed into an arc shape extending in the circumferential direction along the edge holding portion 21 of the battery case 20. Therefore, the circumferential extension length of the contact portion 33a may be formed to be greater than the width of the connecting portion 33b. For example, the contact portion 33a may have an arc shape extending in opposite directions along the circumferential direction of the edge holding portion 21 from the intersection of the connecting portion 33b and the contact portion 33a.

[0127] Reference Figures 1 to 3 , the case cover 40 may have a vent portion 41 formed to prevent an increase in internal pressure due to gas generated inside the battery case 20. If the internal pressure of the battery case 20 increases above a predetermined level, the vent portion 41 may be configured to rupture. For example, the vent portion 41 may be formed in a portion of the case cover 40 and may be an area that is structurally more fragile than surrounding areas so as to be easily ruptured when internal pressure is applied. For example, the vent portion 41 may be an area having a smaller thickness than surrounding areas. Referring to Figure 1 and Figure 2 , the exhaust portion 41 can form an approximately circular closed loop.

[0128] Reference Figures 1 to 3 , the case cover 40 covers the opening formed on one side of the battery case 20. The case cover 40 may be fixed by a curling portion 22 formed on the top of the battery case 20. In this case, the sealing gasket G1 may be inserted between the battery case 20 and the case cover 40 and between the current collector 30 and the case cover 40 to improve the fixing force and airtightness of the battery case 20. In this case, the contact portion 33a may be inserted between the edge pressing portion 21 of the battery case 20 and the sealing gasket G1. By bending the curling portion 22 extending upward from the edge pressing portion 21, the contact portion 33a inserted between the edge pressing portion 21 and the sealing gasket G1 as described above may be fixed.

[0129] Fig.14 is a diagram illustrating a battery pack 3 including a battery cell 1 according to an embodiment of the present disclosure.

[0130] Reference Fig.14 The battery pack 3 according to the embodiment of the present disclosure includes: a battery assembly in which a plurality of battery cells 1 according to the embodiment of the present disclosure are electrically connected as described above, and a battery pack housing 2 accommodating the same. For ease of explanation, components such as bus bars for electrical connection, cooling units, and power terminals are omitted from the drawings of the present disclosure.

[0131] Fig.15 It is an example including Fig.14 FIG. 5 is a diagram of a vehicle 5 having a battery pack 3 in the vehicle.

[0132] Reference Fig.15 The vehicle 5 according to the embodiment of the present disclosure may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes the battery pack 3 according to the embodiment of the present disclosure. The vehicle 5 includes a four-wheel vehicle and a two-wheel vehicle. According to the embodiment of the present disclosure, the vehicle 5 operates by receiving power from the battery pack 3.

[0133] As described above, although the present disclosure has been described with reference to limited embodiments and drawings, the present disclosure is not limited thereto, and those skilled in the art to which the present disclosure belongs may make various modifications and variations within the technical concept of the present disclosure and the equivalent scope of the appended claims.

[0134] [reference numerals list]

[0135] 5: Vehicles

[0136] 3: Battery Pack

[0137] 2: Battery pack housing

[0138] 1: Battery Cell

[0139] 10: Electrode assembly

[0140] 11: First uncoated portion

[0141] 12: Second uncoated portion

[0142] H1: Winding hole

[0143] 20: Battery housing

[0144] 21: Edge pressing part

[0145] 22: Curling part

[0146] 30: Current collector

[0147] H2: Current collector hole

[0148] 31: Support part

[0149] 32: Joint connection part

[0150] 33: Shell connection part

[0151] 33a: Contact part

[0152] 33b: Connection part

[0153] N: Notch

[0154] F: Bending part

[0155] S1: First state

[0156] S2: Second state

[0157] S3: The third state

[0158] 40: Shell cover

[0159] 41: Exhaust part

[0160] G1: Sealing pad

Claims

1. A battery cell, comprising: an electrode assembly in which a first electrode and a second electrode are wound around a winding axis while a separator is interposed between the first electrode and the second electrode to define a core portion and an outer peripheral surface, the first electrode including a first uncoated portion not coated with an active material layer in a winding direction; a battery case having an opening disposed on one side of the battery case and configured to accommodate the electrode assembly through the opening; as well as A current collector comprising: a support portion disposed on an upper portion of the electrode assembly, a joint connection portion extending from the support portion and connected to the first uncoated portion, and a case connection portion extending from the support portion to be electrically connected to an inner surface of the battery case and configured so that its length can be extended.

2. The battery cell according to claim 1, in, A boundary between the support portion and the case coupling portion is bent so that an end portion of the case coupling portion faces the opening and the inner surface of the battery case.

3. The battery cell according to claim 1, in, The case coupling portion extends in a winding axis direction of the electrode assembly and in a radial direction of the electrode assembly.

4. The battery cell according to claim 1, in, The housing connection portion comprises: a contact portion coupled to the inner surface of the battery case; and A connecting portion connects the supporting portion and the contact portion.

5. The battery cell according to claim 1, in, The housing coupling portion is configured such that its length can be compressed.

6. The battery cell according to claim 1, in, At least a portion of the housing coupling portion has a flange shape with a hollow center.

7. The battery cell according to claim 1, in, At least a portion of the housing coupling portion has an elliptical planar shape.

8. The battery cell according to claim 1, in, At least a portion of the housing coupling portion has a polygonal planar shape.

9. The battery cell according to claim 4, in, The outer edge of the connecting portion has at least one notch, and the at least one notch is arranged to be recessed toward the inside of the connecting portion.

10. The battery cell according to claim 4, in, The connecting portion has at least one bent portion.

11. The battery cell according to claim 10, in, The bent portion has a convex shape in a direction toward the opening.

12. The battery cell according to claim 4, in, The contact portion has a continuous shape along the inner surface of the battery case.

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

14. A vehicle comprising at least one battery pack according to claim 13.

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