Current collector, battery cell, battery module, battery pack and vehicle comprising same

Abstract

A battery cell according to one embodiment of the present invention comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis so as to define a core part and an outer peripheral surface, the first electrode includes an active material portion coated with an active material layer in the winding direction and a first uncoated portion not coated with the active material layer, and at least a portion of the first uncoated portion itself serves as an electrode tab; a battery case for accommodating the electrode assembly through an opening formed on one side thereof; and a current collector including a tab coupling portion coupled to the first uncoated portion, and a case coupling portion extending from the tab coupling portion and electrically coupled with an inner surface of the battery case, the case coupling portion having at least one notch portion.

Description

Technical Field

[0001] This disclosure relates to current collectors, battery cells, battery modules, battery packs, and vehicles including the same. This application claims priority to and is based on Korean Patent Application No. 10-2023-0191777 filed with the Korean Intellectual Property Office on December 26, 2023; Korean Patent Application No. 10-2024-0025957 filed with the Korean Intellectual Property Office on February 22, 2024; and Korean Patent Application No. 10-2024-0067268 filed with the Korean Intellectual Property Office on May 23, 2024, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0002] Secondary batteries, based on their ease of application and electrical properties such as high energy density, are commonly used in electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric drive sources, as well as portable devices. Due to their primary advantage of significantly reducing fossil fuel use and another advantage of not producing byproducts from energy consumption, these secondary batteries are attracting attention as a new energy source for improving environmental friendliness and energy efficiency.

[0003] Currently widely used rechargeable batteries include lithium-ion batteries, lithium polymer batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and nickel-zinc batteries. The operating voltage of a single rechargeable battery cell (i.e., a single battery cell) is approximately 2.5V to 4.5V. Therefore, when a higher output voltage is required, multiple battery cells can be connected in series to configure a battery pack. Alternatively, depending on the required charge / discharge capacity of the battery pack, multiple battery cells can be connected in parallel to configure the battery pack. Therefore, the number of battery cells included in a battery pack can be set in various ways according to the required output voltage or charge / discharge capacity.

[0004] Furthermore, the current collector included in conventional battery cells is designed with four-way blades and is welded to the flat portion of the CBD. Therefore, in major welding management projects, welding debris spatter may be introduced during welding in the worst-case scenario. Specifically, when welding is performed on the raised portion between the upper bend of the crimp neck and the current collector due to the thickness tolerance of the raw material wall of the can, the tolerance of the flat portion of the upper crimp neck, and welding adjustment tolerances, debris may flow in. Summary of the Invention

[0005] Technical issues

[0006] This disclosure aims to solve the problems of the related technology. Therefore, this disclosure aims to perform welding in a local area by forming a notch on the contact portion of the current collector included inside the battery cell, thereby reducing the size of the laser irradiation unit.

[0007] In addition, this disclosure aims to improve welding performance while reducing the power of the laser beam.

[0008] Furthermore, this disclosure aims to reduce the inflow of debris during the process.

[0009] In addition, the purpose of this disclosure is to reduce the back bead of the weld.

[0010] However, the technical problems sought to be solved by this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of the invention that are not mentioned above.

[0011] Technical solution

[0012] In one aspect of this disclosure, a battery cell is provided, comprising: an electrode assembly configured by winding a first electrode, a second electrode, and a separator inserted between the first and second electrodes around a winding axis to define a core and an outer surface, the first electrode comprising an active material portion coated with an active material layer along a winding direction and a first uncoated portion uncoated with an active material layer, and at least a portion of the first uncoated portion itself serving as an electrode connector; a battery housing configured to receive the electrode assembly through an opening formed on one side; and a current collector comprising a connector connection portion and a housing connection portion, the connector connection portion being connected to the first uncoated portion, the housing connection portion extending from the connector connection portion and electrically connected to an inner surface of the battery housing, wherein at least one notch is provided in the housing connection portion.

[0013] The battery casing may have a rolled edge that is recessed inward at the end adjacent to the opening.

[0014] According to embodiments of the present disclosure, the housing connection portion may include: a contact portion connected to the rolled edge portion of the battery housing; and a connection portion connecting the connector connection portion and the contact portion.

[0015] Here, the notch can be provided on the contact part.

[0016] According to embodiments of this disclosure, the notch is configured to be irradiated by a laser beam.

[0017] The width of the notch can be configured to be 10% to 90% of the width of the laser beam.

[0018] According to another embodiment of this disclosure, the notch may extend in a direction perpendicular to the radial direction of the battery cell.

[0019] According to another embodiment of this disclosure, a plurality of notches may be provided in a contact portion.

[0020] For example, the notches can be configured to be spaced apart from each other by a predetermined distance in the radial direction of the battery cells.

[0021] According to another embodiment of this disclosure, a plurality of notches may be included within the width of the laser beam.

[0022] According to an embodiment of this disclosure, the notch may be located on the flat upper surface of the rolled edge.

[0023] According to another embodiment of this disclosure, the contact portion may have a weld bead formed by irradiation with a laser beam.

[0024] The notch can be formed by cutting a predetermined portion of the housing connection to partially reduce the thickness of the housing connection.

[0025] The notch can be located on the flat upper surface of the rolled edge, and the center of the weld can be located inward from the center of the flat upper surface of the rolled edge.

[0026] According to another embodiment of this disclosure, the width of the weld bead can be configured to be 10% to 35% of the recess depth of the rolled edge.

[0027] In addition, this disclosure provides a battery pack including at least one battery cell according to this disclosure.

[0028] Additionally, this disclosure provides a vehicle that includes at least one battery pack according to this disclosure.

[0029] Beneficial effects

[0030] According to this disclosure, the notch provided in the contact portion of the current collector included in the cylindrical battery cell enables smooth welding even in localized areas.

[0031] Furthermore, according to this disclosure, the size of the laser beam can be reduced.

[0032] Furthermore, according to this disclosure, welding performance can be improved by reducing the power of the laser beam.

[0033] Furthermore, according to this disclosure, the inflow of debris splashes during the process can be reduced.

[0034] In addition, according to this disclosure, it is possible to reduce the number of weld beads on the back side of the weld.

[0035] However, the effects that can be obtained from this disclosure are not limited to those described above, and those skilled in the art will clearly understand from the following description of the invention that are not mentioned above. Attached Figure Description

[0036] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, are intended to provide a further understanding of the technical features of the present disclosure. Therefore, the present disclosure should not be construed as being limited to the drawings.

[0037] Figure 1 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0038] Figure 2 yes Figure 1 A three-dimensional cross-sectional view of the battery cell.

[0039] Figure 3 yes Figure 1 A cross-sectional view of the battery cell.

[0040] Figure 4 This is a plan view showing a current collector according to an embodiment of the present disclosure.

[0041] Figure 5 It is shown Figure 4 The diagram shows the current collector being placed on the rolled edge.

[0042] Figure 6 yes Figure 4 Enlarged view of the contact portion of the current collector.

[0043] Figure 7 yes Figure 6 Enlarged view of the notch and weld bead in the contact area.

[0044] Figure 8 It shows the setting Figure 4 A diagram showing the relationship between the notch in the current collector and the laser beam.

[0045] Figure 9 It is shown Figure 4 A cross-sectional view showing the current collector being placed on the rolled edge.

[0046] Figure 10 This is a diagram illustrating a comparative example of the present disclosure.

[0047] Figure 11 This is a diagram showing the location where a weld bead is formed in the current collector according to an embodiment of the present disclosure.

[0048] Figure 12 This is a diagram showing a battery pack including battery cells according to embodiments of the present disclosure.

[0049] Figure 13 It shows including Figure 12 A diagram of a vehicle with a battery pack. Detailed Implementation

[0050] In the following, preferred embodiments of the present disclosure will be described in detail with reference to the accompanying drawings. Before description, it should be understood that the terminology used in the specification and appended claims should not be construed as limited to its general or dictionary meaning, but rather should be interpreted according to the meaning and concept corresponding to the technical aspects of the present disclosure, based on the principle that the inventors are allowed to appropriately define the terms to obtain the best interpretation. Therefore, the description presented herein is merely a preferred example for illustrative purposes and is not intended to limit the scope of the present disclosure; thus, it should be understood that other equivalents and modifications can be made thereto without departing from the scope of the present disclosure.

[0051] For ease of explanation and clarification, the dimensions of some elements shown in the accompanying drawings may be exaggerated rather than reflecting their actual dimensions. Additionally, the same reference numerals may indicate the same elements between embodiments.

[0052] The statement that two objects being compared are essentially the same means that they are "substantially identical". Therefore, "substantially identical" can include cases where the deviation is considered low in the art (e.g., less than 5%). Additionally, a parameter that is uniform in a region can also indicate uniformity from an average perspective.

[0053] Although terms such as "first" and "second" 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, and unless otherwise stated, a first element may also be a second element.

[0054] Throughout this specification, unless otherwise stated, each element may include a single element or multiple elements.

[0055] The configuration of a component being positioned "above (or below)" or "top (or bottom)" of a target component indicates that the component can be configured to contact the upper (or lower) surface of the target component, and that another component can be inserted between the target component and the component positioned at the top (or bottom) of the target component.

[0056] In addition, the phrase “a component is ‘connected,’ ‘joined,’ or ‘fastened’ to another component” should be understood as meaning that components can be directly connected or joined to each other, and that another component can be “inserted” between components, or that components can be “connected,” “joined,” or “fastened” to another component.

[0057] Throughout this specification, unless otherwise stated, “A and / or B” may mean A or B or A and B, and unless otherwise stated, “C to D” may indicate “equal to or greater than C and equal to or less than D”.

[0058] For ease of explanation, in this specification, the length direction of the winding axis of the electrode assembly wound in a core shape will be referred to as the axial direction. Additionally, the direction around the winding axis will be referred to as the circumferential direction. Furthermore, the direction approaching or away from the winding axis will be referred to as the radial direction. The direction approaching 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.

[0059] Figure 1 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure. Figure 2 yes Figure 1 A three-dimensional cross-sectional view of the battery cell. Figure 3 yes Figure 1 A cross-sectional view of the battery cell.

[0060] Reference Figures 1 to 3 According to embodiments of the present disclosure, the battery cell 1 includes an electrode assembly 10, a battery casing 20, and a current collector 30. In addition, the battery cell 1 may also include a casing cover 40, terminals 50, a sealing gasket G1, a second current collector 60, and / or an insulator 70. This disclosure is not limited to a specific type of battery and is applicable to other types of batteries, such as prismatic batteries.

[0061] The electrode assembly 10 includes a first uncoated portion 11 and a second uncoated portion 12. More specifically, the electrode assembly 10 is configured to define a core and an outer surface by winding a first electrode and a second electrode around a winding axis (parallel to the Z-axis direction) with a separator inserted therebetween. That is, the electrode assembly 10 used in this disclosure can be a wound-core type electrode assembly 10. In this case, an additional separator can be provided on the outer surface of the electrode assembly 10 for insulation from the battery housing 20. The electrode assembly 10 can have a winding structure known in the art without limitation.

[0062] The electrode assembly 10 has a first uncoated portion 11 and a second uncoated portion 12 arranged in opposite directions. Furthermore, the first uncoated portion 11 and the second uncoated portion 12 are exposed outside the diaphragm. In this electrode assembly 10, only a portion of the first uncoated portion 11 and the second uncoated portion 12 can be defined as an electrode connector and used.

[0063] 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. The first electrode is in the width direction (with...) Figure 1The battery cell 1 shown has an uncoated portion at one end (parallel to the height direction) (Z-axis direction) where no first electrode active material is coated. That is, the first electrode includes an uncoated portion at its long side end in the winding direction that is exposed to the outside of the separator where no active material is coated. Hereinafter, the uncoated portion serving as the first electrode connector will be referred to as the first uncoated portion 11. The first uncoated portion 11 extends along the height direction (parallel to the height direction) (Z-axis direction). Figure 1 The battery cell 1 shown (parallel in height direction) is positioned at the top of the electrode assembly 10 housed within the battery casing 20. That is, the first electrode includes a first uncoated portion 11 at its long side end, where no active material layer is coated, exposing it to the outside of the separator, and at least a portion of the first uncoated portion 11 itself serves as an electrode connector. The first uncoated portion 11 can be, for example, a negative electrode connector. In this case, the first electrode is a negative electrode plate.

[0064] Furthermore, at least a portion of the first uncoated portion 11 may include multiple segments divided along the winding direction of the electrode assembly 10. In this case, the multiple segments may be bent in the radial direction (perpendicular to the Z-axis direction) (e.g., the X-axis direction) of the electrode assembly 10.

[0065] Reference Figure 2 and Figure 3 The multiple curved segments of the first uncoated portion 11 can overlap each other in multiple layers to form a curved surface. In this case, the connector connection portion 32 of the current collector 30 (described later) can be connected to the curved surface. The connector connection portion 32 can be connected to the area where the multiple segments overlap each other in multiple layers. In this case, welding can be performed in a specific area when the connector connection portion 32 is placed on the curved surface of the first uncoated portion 11. That is, the connector connection portion 32 can be connected to the area where the multiple segments of the first uncoated portion 11 overlap in multiple layers. For example, as Figure 5 As shown, the joint connection portion 32 may have at least one weld portion in a specific area when it is placed on the curved surface of the first uncoated portion 11.

[0066] The second electrode includes a second electrode current collector and a second electrode active material coated on one or both surfaces of the second electrode current collector. The second electrode is in the width direction (with...) Figure 1The battery cell 1 shown has an uncoated portion (without a second electrode active material coated on its other end, parallel to the height direction) at one end. That is, the second electrode includes an uncoated portion exposed to the outside of the separator at its long side end in the winding direction. Hereinafter, the uncoated portion serving as the second electrode connector will be referred to as the second uncoated portion 12. The second uncoated portion 12 is disposed at the bottom of the electrode assembly 10 housed in the battery casing 20 along the height direction. That is, the second electrode includes a second uncoated portion 12 with an uncoated active material layer at its long side end exposed to the outside of the separator, and at least a portion of the second uncoated portion 12 itself serves as an electrode connector. The second uncoated portion 12 can be, for example, a positive electrode connector. In this case, the second electrode is a positive electrode plate.

[0067] Furthermore, in this disclosure, any active material known in the art can be used as the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate. Preferably, the battery cell 1 can be, for example, a cylindrical secondary battery having a shape factor ratio (diameter to height ratio) greater than about 0.4. Preferably, the diameter of the cylindrical secondary battery can be 40 mm to 50 mm, and the height can be 60 mm to 130 mm. The shape factor of the battery cell 1 can be, for example, 46110, 4875, 48110, 4880, or 4680.

[0068] Reference Figures 1 to 3 The battery housing 20 is a generally cylindrical container with an opening formed on one side and is made of a conductive metallic material. In one example, the battery housing 20 may be made of steel, nickel-plated steel, or stainless steel (SUS), and may be a battery can, but this disclosure is not limited thereto. The side surface of the battery housing 20 and the lower surface positioned opposite the opening are generally formed as one workpiece. That is, the battery housing 20 generally has an upper opening in the height direction (Z-axis direction) and a closed portion at the bottom. The lower surface of the battery housing 20 may have a substantially flat shape. The battery housing 20 accommodates the electrode assembly 10 through the opening formed on one side in the height direction. The battery housing 20 may also accommodate the electrolyte through the opening.

[0069] The battery housing 20 may have a rolled edge 21 formed at an end adjacent to an opening provided at the top of the battery housing 20. The battery housing 20 may also include a press-fit portion 22 formed on the rolled edge 21. The rolled edge 21 is configured by recessing the outer periphery of the battery housing 20 to a predetermined depth. More specifically, the rolled edge 21 may be configured to be recessed inwardly in the region between the opening formed on one side of the battery housing 20 and the receiving portion for receiving the electrode assembly 10.

[0070] A rolled edge 21 is formed above the electrode assembly 10. The inner diameter of the battery housing 20 in the region where the rolled edge 21 is formed is configured to be smaller than the diameter of the electrode assembly 10. At least one connector connection 32 of the current collector 30 (described later) may be positioned lower than the rolled edge 21.

[0071] The crimped portion 21 provides a support surface on which the housing cover 40 can be disposed. Additionally, the crimped portion 21 provides a support surface on which at least a portion of the edge of the current collector 30, described later, can be disposed and attached. That is, at least a portion of the edge of the current collector 30 and / or the edge of the housing cover 40 can be disposed on the upper surface of the crimped portion 21. To stably support at least a portion of the edge of the current collector 30 and / or the edge of the housing cover 40, the upper surface of the crimped portion 21 can extend in a direction substantially parallel to the lower surface of the battery housing 20, that is, in a direction substantially perpendicular to the sidewall of the battery housing 20.

[0072] The rolled edge 21 prevents the electrode assembly 10, which may have a size that approximately corresponds to the inner diameter of the battery housing 20, from detaching through the opening formed at the top of the battery housing 20, and can also serve as a support for the housing cover 40. The upper rolled edge 21 can also serve as a support for fixing the contact portion 33a of the current collector 30, the sealing gasket G1, and the housing cover 40.

[0073] A crimping portion 22 is formed on the rolled edge portion 21. The crimping portion 22 extends and bends to wrap around the edge of the housing cover 40 provided on the rolled edge portion 21. This shape of the crimping portion 22 secures the housing cover 40 to the rolled edge portion 21.

[0074] Next, refer to Figures 1 to 11 The current collector 30 according to embodiments of the present disclosure will be described in detail compared with conventional current collectors.

[0075] Reference Figures 1 to 3 According to embodiments of the present disclosure, the current collector 30 is housed inside the battery housing 20, electrically connected to the electrode assembly 10, and also electrically connected to the battery housing 20. In other words, the current collector 30 electrically connects the electrode assembly 10 and the battery housing 20.

[0076] Figure 4 This is a diagram illustrating a current collector according to an embodiment of the present disclosure. Figure 5 It is shown Figure 4 The diagram shows the current collector being placed on the rolled edge.

[0077] Reference Figure 4 and Figure 5The current collector 30 includes a support portion 31 located on one surface of the electrode assembly 10, a connector connection portion 32 extending from the support portion 31 and connected to the first uncoated portion 11, and a housing connection portion 33 extending from the support portion 31 and connected to the inner surface of the battery housing 20.

[0078] The connector 32 and the housing connector 33 are indirectly connected via the support 31, rather than being directly connected to each other. Therefore, when an external impact is applied to the battery cell 1 of this disclosure, damage to the connection between the current collector 30 and the electrode assembly 10, as well as the connection between the current collector 30 and the battery housing 20, can be minimized.

[0079] Return to reference Figure 4 The housing connection portion 33 has at least one notch N. A laser beam can irradiate the notch N. Therefore, the inner surface of the housing connection portion 33 and the battery housing 20 can be welded together.

[0080] As described above, according to this disclosure, at least one notch N provided in the housing connection portion 33 of the current collector 30 facilitates local welding of the housing connection portion 33. That is, if the notch N is provided in this disclosure, the laser beam can irradiate the notch N, thereby significantly reducing the possibility of welding defects. Furthermore, according to the above configuration, since welding performance is improved, it is not necessary to set the laser power unnecessarily high. In other words, according to this disclosure, the desired welding performance can be achieved while reducing the size of the laser beam irradiation unit and the power of the laser beam.

[0081] For example, if the power of the welding laser is too high, impurities known as back weld beads are generated on the back surface of the weld. However, according to the configuration of this disclosure, the occurrence of back weld beads can be prevented due to the reduced power of the laser beam.

[0082] Reference Figure 4 One or more connector joints 32 and / or one or more housing joints 33 may be provided. The connector joints 32 and housing joints 33 may be arranged around the center of the current collector 30, for example, substantially radially, intersectingly, or a combination thereof. Alternatively, each of the plurality of housing joints 33 may be disposed between adjacent connector joints 32.

[0083] Reference Figure 3A support portion 31 and multiple connector portions 32 are disposed on the top of the electrode assembly 10. The connector portions 32 are connected to a first uncoated portion 11 of the electrode assembly 10. The connector portions 32 can be connected to the first uncoated portion 11, for example, by welding in the radial direction of the electrode assembly 10. The connector portions 32 can be welded to the first uncoated portion 11 in a state substantially parallel to the lower surface of the battery housing 20. Furthermore, the support portion 31 and the connector portions 32 can be connected to the first uncoated portion 11.

[0084] The current collector 30 can be made of the same type of metal as the first electrode current collector, or of a material to which it is well welded. For example, it can be copper or a copper alloy, nickel or a nickel alloy, steel, SUS, or a composite thereof.

[0085] The support portion 31 may have 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 interconnected winding hole H1 and current collector hole H2 can serve as channels for inserting welding rods or irradiating a laser beam for welding between the terminal 50 and the second current collector 60, as will be described later, or for welding between the terminal 50 and a lead connector (not shown). The current collector hole H2 may have a diameter substantially the same as or larger than that 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 excessively smaller than the diameter of the winding hole H1, the hole formed in the winding hole H1 may be covered, which may reduce injection performance and may also make it difficult to ensure sufficient space for inserting welding devices or for laser irradiation.

[0086] Multiple connectors 32 may be configured to extend generally radially from the support 31 of the current collector 30 toward the sidewall of the battery housing 20. The multiple connectors 32 may be positioned to be spaced apart from each other along the periphery of the support 31.

[0087] Multiple housing connection portions 33 may be configured to extend generally radially from the support portion 31 of the current collector 30 toward the sidewall of the battery housing 20. The multiple housing connection portions 33 may be positioned spaced apart from each other along the periphery of the support portion 31. At least one housing connection portion 33 may be positioned between adjacent connector connection portions 32.

[0088] Reference Figure 5 The housing connection portion 33 can extend from the support portion 31 and be electrically connected to the inner surface of the battery housing 20. For example, the housing connection portion 33 can be connected to, for example, the rolled edge portion 21 of the inner surface of the battery housing 20. In particular, the housing connection portion 33 can be connected to the upper surface of the rolled edge portion 21.

[0089] In the battery cell 1 of this disclosure, the housing connection portion 33 can be fixed to the rolled edge portion 21 by storing the electrode assembly 10, to which the current collector 30 is connected, inside 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... Figure 5 As shown, at least one weld bead BW can be provided between the rolled edge portion 21 and the housing connecting portion 33. That is, the current collector 30 can include at least one weld bead BW welded to the inner surface of the battery housing 20. The battery housing 20 and the current collector 30 can be welded by, for example, laser welding, ultrasonic welding, or spot welding. In addition, the upper surface of the rolled edge portion 21 can be configured to extend in a direction substantially parallel to the lower surface of the battery housing 20, that is, in a direction substantially perpendicular to the sidewall of the battery housing 20, and the housing connecting portion 33 can also be configured to extend in the same direction, that is, in both the radial and circumferential directions, so that the housing connecting portion 33 can be in stable contact with the rolled edge portion 21. Furthermore, as described above, since the housing connecting portion 33 is in stable contact with the rolled edge portion 21, the two components can be welded smoothly, thereby improving the joint strength between the two components and minimizing the increase in resistance at the joint.

[0090] Reference Figure 4 and Figure 5 The housing connection portion 33 may include: a contact portion 33a, which is coupled to the inner surface of the battery housing 20; and a connection portion 33b, which connects the support portion 31 and the contact portion 33a. In one aspect of this disclosure, the first connector connection portion 32 may have a wider width than the connection portion 33b. In another aspect of this disclosure, the contact portion 33a may have a wider width than the connection portion 33b. Here, "width" refers to the dimension along a direction perpendicular to the radial direction.

[0091] The contact portion 33a is attached to the inner surface of the battery housing 20. Preferably, the contact portion 33a can be attached to the rolled edge portion 21 of the battery housing 20. In this case, for stable contact and connection, both the rolled edge portion 21 and the contact portion 33a can be configured to extend in a direction substantially parallel to the lower surface of the battery housing 20, that is, in a direction substantially perpendicular to the sidewall of the battery housing 20.

[0092] At least a portion of the contact portion 33a may have an arcuate shape extending circumferentially along the rolled edge 21 of the battery housing 20. Therefore, the circumferential extension length L_33a of the contact portion 33a may be larger than the width L_33b of the connecting portion 33b. In this case, to maximize the contact area, the current collector 30 may be configured such that the sum of the circumferential extension lengths of the contact portions 33a of the plurality of housing connecting portions 33 is substantially the same as or slightly smaller than the inner circumference of the battery housing 20. On the other hand, the contact portion 33a may be configured in an arcuate shape extending in opposite directions circumferentially from the intersection of the connecting portion 33b and the contact portion 33a on the rolled edge 21.

[0093] Reference Figure 4 The current collector 30 of this disclosure may have at least one injection hole H3. The injection hole H3 may be provided, for example, in a connector connection portion 32. In the case where multiple connector connection portions 32 are provided, the injection hole H3 may be provided in at least one connector connection portion 32. (Refer to...) Figure 3 and Figure 4 When manufacturing the battery cell 1 according to an embodiment of the present disclosure, an assembly including the electrode assembly 10 and the current collector 30 can be stored inside the battery casing 20, and then an electrolyte can be injected. In this case, the injection performance can be improved due to the injection holes H3. A connector connection portion 32 may have a plurality of injection holes H3. The plurality of injection holes H3 may be arranged substantially symmetrically in the left-right direction with respect to the center in the width direction of the connector connection portion 32.

[0094] Preferably, the battery casing 20 and the current collector 30 are welded by laser welding. Applying laser welding is advantageous in ensuring quality and performance, and improving product yield, by preventing deformation caused by contact pressure welding such as resistance welding. Furthermore, since it eliminates the need to replace welding rods or welding heads, it is advantageous in improving production efficiency, reducing production costs, and shortening manufacturing process time. Laser welding has higher joint strength than ultrasonic welding and, compared to resistance welding, also ensures uniformity in weld performance and quality. The laser beam travels directly downwards from the top of the battery casing 20 to the surface to be welded at the contact portion 33a. The laser welding apparatus can be configured to include: a laser source (laser beam source); a laser irradiation unit including optical components such as collimators, lenses, and mirrors for focusing the laser from the laser source to generate a laser beam with a predetermined spot diameter, and irradiating the laser beam onto the workpiece to be welded; and a system for spraying welding atmosphere gas and removing byproducts. The spot diameter indicates the diameter at the precise focal position. Although welding can be performed in air, it may be desirable to partially inject an inert gas such as nitrogen (N2) or argon (Ar), and therefore a welding atmosphere gas injection system may be included, which includes an inert gas supply unit. Additionally, a byproduct removal system may be included, which includes a dust collector for suction and removal of welding fumes.

[0095] Figure 6 yes Figure 4 An enlarged view of the contact portion of the current collector. Figure 7 yes Figure 6 Enlarged view of the notch and weld bead at the contact area. Figure 7 The figure below shows a cross-section taken along line A-A' in the figure above. Figure 8 It shows the setting Figure 4 A diagram showing the relationship between the notch in the current collector and the laser beam.

[0096] Reference Figures 4 to 6 A notch N can be provided on the contact portion 33a. A laser beam can irradiate the notch N. Therefore, the contact portion 33a and the inner surface of the battery casing 20 can be welded to each other. More preferably, the contact portion 33a and the rolled edge portion 21 can be welded. That is, a weld bead BW can be formed between the contact portion 33a and the rolled edge portion 21 by irradiation with a laser beam.

[0097] A weld bead typically indicates the deposited metal produced by a single welding operation (one laser beam pass), and can also be referred to as a weld spot. The size, shape, location, and degree of overlap of a weld bead can vary depending on the welding conditions. In this specification, the term weld bead (BW) is used to indicate a welded portion, including individually formed and therefore distinct weld beads, as well as weld beads that at least partially overlap to form a single block. Weld bead BW can be formed by wobble welding, spot welding, weaving hatching welding, or scanning welding.

[0098] According to this structure, at least one notch N provided in the contact portion 33a of the current collector 30 facilitates welding, even in a localized area of ​​the contact portion 33a. That is, if the notch N is provided in this disclosure, the laser beam can irradiate the notch N, thereby significantly reducing the possibility of welding defects. Furthermore, according to the above configuration, since welding performance is improved, it is not necessary to set the laser power unnecessarily high. In other words, according to this disclosure, the desired welding performance can be achieved while reducing the size of the laser beam irradiation unit and the power of the laser beam.

[0099] Reference Figure 7 and Figure 8 The notch N can indicate a portion of the current collector 30 (especially the housing connection portion 33), and more specifically, a portion formed by cutting into the contact portion 33a to partially reduce its thickness. However, the notch N herein is not limited to a notch formed by an opening as defined in the dictionary, and can also indicate a space formed by cutting or pressing the current collector 30 by other methods, and can also include a groove inherently formed in the current collector 30 according to the mold shape when the current collector 30 is manufactured by casting. Additionally, the notch N can also comprise a groove or trench-like recess recessed inward from the upper surface of the contact portion 33a of the current collector 30. The depth d_N of the notch N is smaller than the thickness d_33a of the contact portion 33a. Preferably, the depth d_N of the notch N can be less than or equal to 50% of the thickness d_33a of the contact portion 33a. The cross-sectional shape of the notch N can be a V-shaped triangle according to the dictionary definition of a notch, but can also include shapes such as trapezoidal, square, semi-elliptical, semi-circular, etc. In addition, the lower corner of the notch N can be rounded to prevent stress concentration at the corner during opening, thereby preventing cracks.

[0100] The length L_BW of the weld bead BW is a dimension in a direction substantially perpendicular to the radial direction of the battery cell 1, and can be formed in the direction of laser beam irradiation to have a length of approximately 1 mm to 3 mm. The length L_N of the notch N is also a dimension in a direction substantially perpendicular to the radial direction of the battery cell 1, and can be less than or equal to the length L_BW of the weld bead BW.

[0101] The width B of the weld bead BW is a dimension in the radial direction of the battery cell 1, and can be approximately 0.3 mm to 1 mm. The width S of the notch N is also a dimension in the radial direction of the battery cell 1, but is smaller than the width B of the weld bead BW.

[0102] The weld bead BW is not limited to a specific size and shape, as long as it can maintain the joint strength. Regarding the joint strength, it is preferred that the tensile force through the weld bead BW at the joint between the current collector 30 and the battery casing 20 is 2 kgf or greater, preferably 3 kgf to 15 kgf, and more preferably 5 kgf to 15 kgf. The tensile force is a force applied perpendicular to the joint surface. The tensile force can be converted into tensile strength by multiplying by the area of ​​the surface to which the force is applied. If the tensile force is 2 kgf or greater, preferably 3 kgf or greater, the performance of the battery cell 1 will not be affected when using the battery cell 1, and the current collector 30 will not detach from the battery casing 20 due to vibration or pressure generated from the equipment during the process.

[0103] The goal is to maximize tensile force within permissible limits by selecting the optimal welding method. Since the joint strength in terms of tensile force is also related to the area and depth of the weld bead (BW)... Figure 11 This relates to the D_BW (in the context of weld bead), therefore the bonding strength can be adjusted by controlling the area and depth of the weld bead BW. For example... Figure 11 As shown in the cross-section, the weld bead BW is not merely provided on the surface, but should be formed on the contact surfaces of the two components to be welded, having a three-dimensional shape with thickness. The depth of the weld bead BW can be adjusted by the laser beam output and irradiation time. The higher the laser beam output, the deeper the weld bead, and the longer the irradiation time, the deeper the weld bead. The laser beam output and irradiation time can be adjusted so that the weld bead BW does not form sufficiently deep to expose the outer surface of the rolled edge 21 when there is appropriate bonding force. In actual processes, the thickness range of the current collector 30 and the battery casing 20 is fixed, so the depth of the laser beam needs to be adjusted to a level that prevents over-welding. In this disclosure, since at least one notch N is provided in the contact portion 33a of the current collector 30, welding can be performed on a local area of ​​the contact portion 33a, thereby preventing the laser beam depth from becoming too large. A small laser beam depth can be achieved by using a low-output laser beam, thus reducing manufacturing costs and reducing the generation of welding debris spatter. A small laser beam depth can also be achieved by shortening the irradiation time, thus shortening manufacturing time and increasing productivity.

[0104] In one aspect of this disclosure, the width S of the notch N can be configured within the range of approximately 10% to 90% of the width L of the laser beam. Here, the width L of the laser beam can indicate the spot diameter. The spot diameter of the laser beam can be from 10 μm to 200 μm. When the spot diameter of the laser beam exceeds 200 μm, there is a disadvantage that the impact on corrosion increases and the aspect ratio of the weld bead (BW) decreases, which may reduce welding efficiency. Furthermore, when the laser beam size is less than 10 μm, there is a disadvantage that the welding area is small, and sufficient bonding force cannot be ensured in a single weld. Therefore, it is desirable for the laser beam spot diameter to meet the above-mentioned range. Preferably, the laser beam spot diameter can be approximately 50 μm.

[0105] For example, refer to Figure 8 The width S of the notch N can be configured to be smaller than the width L of the laser beam. That is, within the scope of this disclosure, a configuration in which the width S of the notch N is included within the width L of the laser beam is possible. If the width S of the notch N becomes larger than the width L of the laser beam, it may no longer function as a notch N. This is due to the fact that the notch N used as a guide wire for laser beam irradiation to perform welding can only perform this function when it is smaller than the width L of the laser beam.

[0106] On the other hand, if the width S of the notch N is less than about 10% of the width L of the laser beam, the notch N becomes too small, making it difficult to detect the notch N used for welding. In another embodiment, if the width S of the notch N is greater than about 90% of the width L of the laser beam, the notch N becomes too large, becoming almost the same as the width L of the laser beam, thus increasing the positional offset of the weld bead BW. For example, the center of the laser beam can be positioned within the notch N, but if the width of the notch N is excessively increased, the area where the center of the laser beam can be positioned may increase. As a result, the positional offset of the weld bead BW to be welded becomes larger, making it difficult to ensure an accurate welding position. Therefore, it is preferable that the width of the notch N is in the range of about 10% to 90% of the width L of the laser beam.

[0107] In another embodiment of this disclosure, the notch N can be configured to extend in a direction substantially perpendicular to the radial direction of the battery cell 1. For example, refer to... Figures 6 to 8The notch N can be configured to extend in a straight line along a direction substantially perpendicular to the radial direction of the battery cell 1. Therefore, the weld bead BW can be formed on the rolled edge 21 as a straight weld pattern having a length L_BW extending substantially along the circumferential direction. Alternatively, as another embodiment, the notch N can be configured as an arcuate shape substantially perpendicular to the radial direction of the cylindrical battery cell 1. Therefore, at least one weld bead BW formed between the rolled edge 21 and the contact portion 33a can be formed on the rolled edge 21 as an arcuate weld pattern extending substantially along the circumferential direction. The weld bead BW formed on the contact portion 33a can be configured to extend in the circumferential direction.

[0108] If the notch N extends substantially parallel to the radial direction of the battery cell 1, the weld length may be shortened, potentially making it impossible to ensure sufficient weld performance. Furthermore, if the notch N extends substantially parallel to the radial direction of the battery cell 1, the number of weld operations required to ensure the necessary weld strength increases. As a result, the efficiency of this process may decrease. On the other hand, according to the structure of the present disclosure, where the notch N extends substantially perpendicular to the radial direction of the battery cell 1, the efficiency of the process can be improved.

[0109] In another embodiment of this disclosure, a plurality of notches N may be provided in a single contact portion 33a. For example, two or more notches may be provided. For example, see reference... Figures 6 to 8 Multiple notches N can be provided in a contact portion 33a in a direction substantially perpendicular to the radial direction of the battery cell 1. Preferably, the notches N can be arranged to be spaced apart from each other by a predetermined distance along the radial direction of the battery cell 1. For example, refer to Figure 7 Multiple notches N can be configured with a spacing P between them. Welding applied to the notches N may have positional deviations between welding operations. In this case, if multiple notches N are provided, the positional offset of the final weld bead BW can be minimized compared to a structure with only one notch N.

[0110] For example, multiple notches N can be configured to be included within the width L of the laser beam. Therefore, multiple weld points can be formed within a single laser beam. For this purpose, the width S of the notch N needs to be smaller than the width L of the laser beam. As mentioned above, the width S of the notch N is preferably configured in the range of approximately 10% to 90% of the width L of the laser beam.

[0111] Because the welding area may have alignment deviations, it is difficult to perform welding in the same area every time, thus requiring management within a certain level of tolerance. Since the notch N is welded centrally during laser beam irradiation, defects can be reduced during welding if multiple notches N are provided. For example, even if welding is performed slightly off-center from the notch N due to alignment deviations, errors such as reduced welding force and weak welds are reduced when multiple notches N are provided compared to the case with only one notch N. Therefore, it is desirable to provide multiple notches N.

[0112] According to the structure disclosed herein, the welding defect rate can be significantly reduced. Furthermore, since the structure with multiple notches N improves welding strength and prevents errors such as weak welds, it is desirable to have multiple notches N.

[0113] Furthermore, the width S and spacing P of the notch N can be determined taking into account the number of notches N falling within the width B of the weld bead BW and the width L of the laser beam. For example, when the number of notches N is n, n×S+(n-1)×P can be less than B, and S can be less than P. The width S and spacing P of the notch N can be designed to prevent damage, cracking, or deformation of the current collector 30 when forming fine notches N.

[0114] Figure 9 It is shown Figure 4 A cross-sectional view showing the current collector positioned on the rolled edge. Figure 10 This is a diagram illustrating a comparative example of the present disclosure. Figure 11 This is a diagram showing the location where a weld bead is formed in the current collector according to an embodiment of the present disclosure.

[0115] In embodiments of this disclosure, the contact portion 33a may have a flat surface that is connected to the upper surface of the rolled edge portion 21 facing the opening. (See also...) Figures 9 to 11 The contact portion 33a can be disposed on the flat upper surface of the rolled edge portion 21. In this case, the notch N can be located on the flat upper surface of the rolled edge portion 21. In this case, since laser welding is applied to the notch N, the contact portion 33a can be welded to the flat upper surface of the rolled edge portion 21 by a laser beam. More specifically, the contact portion 33a can have a weld bead BW formed by irradiation of the laser beam.

[0116] For example, referring to the comparative examples corresponding to this disclosure Figure 10A predetermined gap G may exist between the contact portion 33a of the housing connection portion 33 and the rolled edge portion 21. More specifically, since the rolled edge portion 21 is configured to be recessed to a predetermined depth D through the outer periphery of the battery housing 20, the rolled edge portion 21 has a substantially flat section 21a and a curved region 21b in the region near the innermost point of the rolled edge portion 21, the curved region 21b having a predetermined radius of curvature. That is, the vertical distance to the contact portion 33a gradually increases from the point starting from the curved region 21b in the radial direction inward from the flat section 21a of the rolled edge portion 21. In other words, as... Figure 10 As shown, there is a small space between the contact portion 33a and the rolled edge portion 21 that gradually widens towards the inner side in the radial direction. In this case, as... Figure 10 As shown, when welding is performed on the area where the micro-gap G is located to form weld bead BW', weld spatter may enter. Weld spatter refers to various impurities (slag) generated during welding, collectively referred to as particles that adhere to or detach from the substrate surface due to failed transition from molten metal to weld metal during welding. As mentioned above, in the past, weld spatter may have entered micro-spaces, and this can be a factor causing defects in post-weld processes as well as during the welding process.

[0117] In this disclosure, because the notch N is provided, the weld bead BW can be formed even if the power of the laser beam required to form a weld bead BW' without the notch is reduced or the size of the laser beam irradiation unit is reduced. Therefore, the generation of welding debris can be reduced, and even if welding is performed in the area where the micro-gap G is located, the problem of introducing welding debris spatter can be significantly solved. Furthermore, in the battery cell 1 according to an embodiment of this disclosure, as... Figure 11 As shown, the notch N can be located on the flat upper surface of the rolled edge portion 21. That is, the notch N is located within the flat section 21a of the rolled edge portion 21, so the contact portion 33a can be welded to the flat upper surface of the rolled edge portion 21 by a laser beam. Preferably, the width B of the weld bead BW formed between the contact portion 33a and the rolled edge portion 21 can be formed to be smaller than the flat section 21a of the rolled edge portion 21.

[0118] As a result, according to this structure of the present disclosure, since welding is performed only in the area where there is no gap G between the contact portion 33a and the rolled edge portion 21 by controlling the formation position of the weld bead BW, the inflow of debris spatter can be reduced during this process.

[0119] In another embodiment of this disclosure, the center of the weld bead BW may be set further inward than the center of the flat upper surface of the rolled edge 21.

[0120] For example, refer to Figure 11The center C_BW of the weld bead BW can be positioned further inward than the center C_21a of the flat upper surface of the rolled edge portion 21. That is, the weld bead BW can be positioned closer to the inner side in the radial direction rather than the outer side on the flat section where no gap G is provided between the contact portion 33a and the rolled edge portion 21.

[0121] With this structure, since welding is performed only in the area where there is no gap between the contact portion 33a and the rolled edge portion 21, the inflow of debris spatter can be reduced during this process. At the same time, since the welding area is further positioned inward in the radial direction, the welding strength between the rolled edge portion 21 and the current collector 30 can be relatively improved. In other words, according to the above structure, the current collector 30 can be more stably bonded to the rolled edge portion 21.

[0122] Since the flat section 21a of the rolled edge portion 21 has a value determined according to the specifications of the battery cell 1, the position of the center C_21a of the flat upper surface of the rolled edge portion 21 is a fixed value in the determined battery cell 1. To ensure that the center C_BW of the weld bead BW is positioned further inward than the center C_21a of the flat upper surface of the rolled edge portion 21, and to ensure that the weld bead BW is formed in a region where there is no gap G between the contact portion 33a and the rolled edge portion 21, it is desirable that the width B of the weld bead BW be smaller. According to this disclosure, since the notch N is formed on the contact portion 33a of the current collector 30, welding can be performed in a localized area, and therefore the width B of the weld bead BW can be configured to be smaller than the width of a conventional weld bead BW'. In another embodiment of this disclosure, the weld bead BW can be formed between the contact portion 33a and the rolled edge portion 21, and the width B of the weld bead BW can be configured to be smaller than the depth D of the rolled edge portion 21. The width B of the weld bead BW can, for example, be greater than or equal to the width L of the laser beam.

[0123] For example, refer to Figure 11 The width B of the weld bead BW is less than the depth D of the rolled edge 21. Preferably, the width B of the weld bead BW can be configured to be about 10% to 35% of the depth D of the rolled edge 21. More preferably, the width B of the weld bead BW can be configured to be about 15% to 31.67% of the depth D of the rolled edge 21. According to the configuration of this disclosure, sufficient weld strength can be ensured while maximizing the efficiency of the welding process.

[0124] The depth D_BW of the weld bead BW can be from 2 mm to 4 mm. If the power of the welding laser is too high, a back weld bead may be generated on the back side of the weld. In this disclosure, since the power of the laser beam can be reduced by the configuration of the notch N, the occurrence of a back weld bead when forming a weld bead BW with a small depth D_BW of 2 mm to 4 mm can be prevented.

[0125] Return to reference Figures 1 to 3The housing cover 40 covers an opening formed on one side of the battery housing 20. The housing cover 40 can be secured by a crimping portion 22 formed on the top of the battery housing 20. In this case, a sealing gasket G1 can be inserted between the battery housing 20 and the housing cover 40, and between the current collector 30 and the housing cover 40, to improve the fixing force and sealing performance of the battery housing 20. In this case, the contact portion 33a and / or the second contact portion 33a can be inserted between the rolled edge portion 21 of the battery housing 20 and the sealing gasket G1. As described above, the contact portion 33a and / or the second contact portion 33a inserted between the rolled edge portion 21 and the sealing gasket G1 can be secured by bending the crimping portion 22 extending upward from the rolled edge portion 21.

[0126] Reference Figure 3 Terminal 50 is electrically connected to the second uncoated portion 12 of the electrode assembly 10 by passing through the battery housing 20 on the opposite side of the opening in the battery housing 20. Terminal 50 may pass approximately through the center of the lower surface of the battery housing 20. Terminal 50 may be connected to a second current collector 60 connected to the second uncoated portion 12, or it may be connected to a lead connector (not shown) connected to the second uncoated portion 12 for electrical connection to the electrode assembly 10. Therefore, terminal 50 may have the same polarity as the second electrode of the electrode assembly 10 and may be used as the second electrode terminal T2. If the second uncoated portion 12 is a positive terminal, terminal 50 may be used as the positive terminal.

[0127] Considering the polarity and function of terminal 50, terminal 50 needs to be insulated from battery housing 20, which has the opposite polarity. For this purpose, an insulating gasket can be provided between terminal 50 and battery housing 20. Alternatively, insulation can be achieved by coating a portion of the surface of terminal 50 with an insulating material.

[0128] For the same reason, the second uncoated portion 12 and / or the second current collector 60 need to be insulated from the battery housing 20. For this purpose, an insulator 70 can be inserted 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 applied, the terminal 50 can pass through the insulator 70 to make an electrical connection with the second uncoated portion 12.

[0129] Furthermore, in this disclosure, the outer surface 20a of the closed portion, positioned opposite to the opening at the top of the battery housing 20, can be used as the first electrode terminal T1. If the first uncoated portion 11 is a negative terminal, then the first electrode terminal T1 can be the negative terminal. The battery cell 1 according to this disclosure has a structure in which the terminal 50 exposed by the lower surface opposite to the opening of the battery housing 20 can be used as the second electrode terminal T2, and the remaining area on the lower surface of the battery housing 20, excluding the area occupied by the terminal 50 (including the area exposed by the insulating gasket when it is exposed on the outer surface 20a of the closed portion to the outside of the terminal 50), can be used as the first electrode terminal T1. Therefore, when multiple battery cells 1 are electrically connected, the battery cell 1 according to this disclosure can connect both the positive and negative terminals in one direction, thereby simplifying the electrical connection structure. In addition, the battery cell 1 according to this disclosure has a structure in which a large portion of the lower surface opposite to the opening of the battery housing 20 can be used as an electrode terminal, thus ensuring sufficient area for welding components for electrical connection.

[0130] Return to reference Figure 2 and Figure 3 The second current collector 60 is connected to the bottom of the electrode assembly 10. The second current collector 60 is made of a conductive metal material and is electrically connected to the second uncoated portion 12.

[0131] Reference Figure 12 The battery pack 3 according to an embodiment of the present disclosure includes: a battery assembly in which a plurality of battery cells 1 according to the above-described embodiment of the present disclosure are electrically connected; and a battery pack housing 2 that houses the battery assembly. In the accompanying drawings of this disclosure, components such as busbars, cooling units, and power terminals for electrical connections are omitted for ease of drawing. The plurality of battery cells 1 are arranged in a predetermined number of rows, and terminals 50 exposed on the lower surface of each battery cell 1 serve as second electrode terminals T2, while the remaining area on the lower surface of the battery housing 20 serves as first electrode terminals T1. Therefore, when multiple battery cells 1 are electrically connected, the positive and negative terminals can be connected in one direction, thereby simplifying the electrical connection structure. This allows for an increase in the number of battery cells 1 to be stored in the same space, thereby increasing energy density and facilitating electrical wiring. Therefore, due to good space efficiency and high electrical wiring efficiency, workability is significantly improved in terms of battery pack 3 assembly and maintenance during the assembly process of electric vehicles.

[0132] Reference Figure 13 The vehicle 5 according to embodiments of the present disclosure may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack 3 according to embodiments of the present disclosure. Vehicle 5 includes four-wheeled vehicles and two-wheeled vehicles. Vehicle 5 operates by electricity supplied from the battery pack 3 according to embodiments of the present disclosure.

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

[0134] [Explanation of reference numerals in the attached figures]

[0135] 5: Vehicles

[0136] 3: Battery pack

[0137] 2: Battery pack casing

[0138] 1: Battery cells

[0139] 10: Electrode assembly

[0140] 11: First uncoated area

[0141] 12: Second uncoated area

[0142] H1: Winding hole

[0143] 20: Battery casing

[0144] 20a: Outer surface of the closed part

[0145] T1: First electrode terminal

[0146] 21: Rolled edge

[0147] 22: Crimping section

[0148] 30: Current collector (first current collector)

[0149] H2: Current collector hole

[0150] 31: Support section

[0151] 32: Connector connection part

[0152] H3: Injection Hole

[0153] 33: Housing connection part

[0154] 33a: Contact part

[0155] 33b: Connecting part

[0156] N: Notch

[0157] BW: Weld bead

[0158] 40: Housing cover

[0159] 41: Exhaust section

[0160] G1: Sealing gasket

[0161] 50: terminal

[0162] T2: Second electrode terminal

[0163] 60: Second current collector

[0164] 70: Insulator

Claims

1. A battery cell, the battery cell comprising: An electrode assembly is configured by winding a first electrode, a second electrode, and a diaphragm inserted between the first electrode and the second electrode around a winding axis to define a core and an outer surface. The first electrode includes an active material portion coated with an active material layer along the winding direction and a first uncoated portion without an active material layer, and at least a portion of the first uncoated portion itself serves as an electrode connector. A battery housing configured to receive the electrode assembly through an opening formed on one side; as well as The current collector includes a connector and a housing connector. The connector is connected to the first uncoated portion, and the housing connector extends from the connector and is electrically connected to the inner surface of the battery housing. At least one notch is provided in the housing connector.

2. The battery cell according to claim 1, in, The battery casing has a rolled edge portion, which is formed to be recessed inward at an end adjacent to the opening.

3. The battery cell according to claim 2, in, The housing connection portion includes: Contact portion, the contact portion being connected to the rolled edge portion of the battery housing; and A connecting part that connects the connector connecting part and the contact part.

4. The battery cell according to claim 3, in, The notch is provided on the contact portion.

5. The battery cell according to claim 3, in, The notch is configured to be illuminated by a laser beam.

6. The battery cell according to claim 5, in, The width of the notch is 10% to 90% of the width of the laser beam.

7. The battery cell according to claim 1, in, The notch extends in a direction perpendicular to the radial direction of the battery cell.

8. The battery cell according to claim 3, in, A plurality of the notches are provided in a contact portion.

9. The battery cell according to claim 1, in, The notches are configured to be spaced apart from each other by a predetermined distance in the radial direction of the battery cells.

10. The battery cell according to claim 5, in, The laser beam includes a plurality of notches within its width.

11. The battery cell according to claim 2, in, The notch is positioned on the flat upper surface of the rolled edge.

12. The battery cell according to claim 5, in, The contact portion has a weld bead formed by the irradiation of the laser beam.

13. The battery cell according to claim 1, in, The notch is formed by cutting a predetermined portion of the housing connection to partially reduce the thickness of the housing connection.

14. The battery cell according to claim 12, in, The notch is positioned on the flat upper surface of the rolled edge, and The center of the weld bead is located inward from the center of the flat upper surface of the rolled edge portion.

15. A current collector comprising a connector portion and a housing portion, the connector portion being connected to an uncoated portion of an electrode assembly of a battery cell, and the housing portion extending from the connector portion and electrically connected to the inner surface of the battery housing of the battery cell. in, At least one notch is provided in the housing connection portion. The notch is configured to be irradiated by a laser beam, and The width of the notch is 10% to 90% of the width of the laser beam.

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

17. A vehicle comprising at least one battery pack according to claim 16.

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