Battery cell, and battery pack and vehicle comprising same

Abstract

A battery cell according to an embodiment of the present invention 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, the first electrode includes an active material portion coated with an active material layer along 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 configured to accommodate the electrode assembly through an opening formed on one side thereof; a housing cover configured to cover the opening and including a through hole at a center thereof; and an intaglio ball configured to be inserted into the through hole.

Description

Technical Field

[0001] This disclosure relates to battery cells, battery packs including the battery cells, and vehicles.

[0002] This application is based on and claims priority to Korean Patent Application No. 10-2024-0040379, filed on March 25, 2024, and Korean Patent Application No. 10-2025-0015117, filed on February 6, 2025, the disclosures of which are incorporated herein by reference in their entirety. Background Technology

[0003] 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. These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency because their main advantage is a significant reduction in fossil fuel use, and another advantage is that they do not produce byproducts resulting from energy use.

[0004] 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 these single-cell rechargeable batteries (i.e., single-cell batteries) is approximately 2.5 V to 4.5 V. Therefore, when a higher output voltage than this operating voltage is required, a battery pack can be configured by connecting multiple cells in series. Alternatively, depending on the required charge / discharge capacity of the battery pack, a battery pack can be configured by connecting multiple cells in parallel. 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.

[0005] Furthermore, battery cells with rolled and pressed structures have existed in the past, and these structures are achieved through rolling, pressing, and sizing processes. A problem with battery cells incorporating such rolled and pressed structures is that the unusable space increases towards the winding axis inside the battery, thereby reducing energy density. Summary of the Invention

[0006] Technical issues

[0007] Therefore, this disclosure aims to increase energy density by eliminating the crimped and press-fitted structures from the battery cell.

[0008] In addition, this disclosure aims to prevent pores from occurring when welding the housing cover and the debossed ball.

[0009] Furthermore, this disclosure aims to prevent the formation of cracks in the welded areas of the housing cover and the recessed ball.

[0010] In addition, this disclosure aims to improve the sealing performance of the contact area between the housing cover and the recessed ball.

[0011] 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.

[0012] Technical solution

[0013] In one aspect of this disclosure, a battery cell is provided, comprising: an electrode assembly defining a core and an outer surface by winding a first electrode and a second electrode and a separator inserted between the first electrode and the second electrode around a winding axis, wherein the first electrode includes an active material portion coated with an active material layer along the winding direction and a first uncoated portion uncoated with an active material layer, at least a portion of the first uncoated portion itself serving as an electrode tab; a battery housing configured to receive the electrode assembly through an opening formed on one side; a housing cover configured to cover the opening and having a through hole in the center; and a recessed ball configured to be inserted into the through hole.

[0014] In embodiments of this disclosure, the side surface of the battery casing may have a cylindrical shape with a constant radius.

[0015] In another embodiment of this disclosure, the housing cover may have a plate shape and may be configured to attach to an opening in the battery housing.

[0016] In another embodiment of this disclosure, the diameter of the through hole may be smaller than the diameter of the winding center hole of the electrode assembly.

[0017] In another embodiment of this disclosure, the diameter of the etched ball may be smaller than the diameter of the winding center hole of the electrode assembly.

[0018] In another embodiment of this disclosure, the etched sphere may have grooves formed on its periphery.

[0019] Preferably, the edge region of the through hole in the housing cover can fit into the groove.

[0020] In another embodiment of this disclosure, the groove may be provided in a region outward in the axial direction of the battery cell based on the center of the etched sphere.

[0021] In another embodiment of this disclosure, based on the groove, the volume of the etched sphere located outside the battery cell can be smaller than the volume of the etched sphere located inside the battery cell.

[0022] In another embodiment of this disclosure, the connection angle between the housing cover and the recessed ball can be greater than 90 degrees.

[0023] In another embodiment of this disclosure, a weld bead can be formed by welding at the contact point between the housing cover and the recessed ball.

[0024] In another embodiment of this disclosure, the weld bead may be formed up to the inner surface of the housing cover.

[0025] In another aspect of this disclosure, a method for manufacturing a battery cell is provided, which may include the steps of: inserting an electrode assembly through an opening in a battery casing; covering the opening in the battery casing with a casing cover; and inserting a recessed ball with grooves formed on its periphery into a through hole formed in the casing cover.

[0026] In another aspect of this disclosure, a battery pack is provided, which includes at least one battery cell according to the above embodiments.

[0027] In another aspect of this disclosure, a vehicle is provided that includes at least one battery pack according to the above embodiments.

[0028] Beneficial effects

[0029] According to this disclosure, energy density can be increased by excluding the rolled edge structure and the crimped structure from the battery cell.

[0030] In addition, according to this disclosure, pores can be prevented when welding the shell cover and the engraved ball.

[0031] Furthermore, according to this disclosure, cracks can be prevented from forming in the welding area of ​​the housing cover and the recessed ball.

[0032] In addition, this disclosure enables improvements in the sealing performance of the contact area between the housing cover and the recessed ball.

[0033] However, the effects that can be obtained according to this disclosure are not limited to those described above, and other effects not mentioned above will be clearly understood by those skilled in the art based on the following description of the invention. Attached Figure Description

[0034] The accompanying drawings illustrate preferred embodiments of the present disclosure and, together with the foregoing disclosure, serve to provide a further understanding of the technical features of the present disclosure; therefore, the present disclosure is not to be construed as limited to the drawings.

[0035] Figure 1 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure.

[0036] Figure 2 yes Figure 1 An exploded 3D view of the battery cell.

[0037] Figure 3 yes Figure 1 A cross-sectional view of the battery cell.

[0038] Figure 4 This is a diagram illustrating the connection process of the engraved ball and the housing cover according to a comparative example of this disclosure.

[0039] Figure 5 This is a diagram showing the shape of a recessed sphere according to an embodiment of the present disclosure.

[0040] Figure 6 This is a diagram showing the state of the concave ball before it is attached to the housing cover according to an embodiment of the present disclosure.

[0041] Figure 7 This is a diagram illustrating the process of inserting a recessed ball into the housing cover according to an embodiment of the present disclosure.

[0042] Figure 8 This is a diagram showing the connection angle between the etched ball and the housing cover according to an embodiment of the present disclosure.

[0043] Figure 9 This is a diagram illustrating the process of performing laser welding when connecting the etched ball and the housing cover according to an embodiment of the present disclosure.

[0044] Figure 10 This is a diagram specifically illustrating the contact area between the etched ball and the housing cover according to an embodiment of the present disclosure.

[0045] Figure 11 It shows including Figure 1 A diagram of the battery module and battery pack.

[0046] Figure 12 It shows including Figure 11 A picture of a vehicle with a battery pack. Detailed Implementation

[0047] Preferred embodiments of the present disclosure will be described in detail below 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 interpreted according to the meaning and concept corresponding to the technical aspects of the present disclosure, based on the principle that inventors are allowed to appropriately define the terms for 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.

[0048] For ease of explanation and clarification of this disclosure, 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 across embodiments.

[0049] The statement that two objects being compared are identical indicates that they are "approximately identical." Therefore, "approximately identical" can include cases with deviations considered low in the art, such as less than 5%. Additionally, parameters that are uniform in a region can indicate uniformity from an average perspective.

[0050] 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, the first element may also be the second element.

[0051] Throughout this specification, unless otherwise stated, each element may include a single element or multiple elements.

[0052] The configuration of a component being positioned in the "upper (or lower) part" or "top (or bottom)" of the target component not only indicates that the component can be positioned to contact the upper (or lower) surface of the target component, but also indicates that another component can be inserted between the target component and the component positioned at the top (or bottom) of the target component.

[0053] In addition, the phrase “a component is ‘connected,’ ‘joined,’ or ‘fastened’ to another component” should be understood as meaning that two components can be directly connected or joined to each other, and that another component can be “inserted” between the two components, or that two components can be “connected,” “joined,” or “fastened” through another component.

[0054] 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 mean “equal to or greater than C and equal to or less than D”.

[0055] For ease of explanation, in this specification, the length direction of the winding axis of the electrode assembly 10 wound into a core shape will be referred to as the "axial direction (Y)". Furthermore, the direction around the winding axis will be referred to as the "circumferential direction (X)". Additionally, 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".

[0056] Figure 1 This is a diagram illustrating a battery cell according to an embodiment of the present disclosure. Figure 2 yes Figure 1 An exploded 3D view of the battery cell, and Figure 3 yes Figure 1 A cross-sectional view of the battery cell.

[0057] Reference Figures 1 to 3According to embodiments of the present disclosure, the battery cell 1 includes an electrode assembly 10, a battery casing 20, a casing cover 30, and a recessed ball 40. The battery cell 1 may also include a current collector 50. This disclosure is not limited to batteries of a specific shape, but can be applied to batteries of other shapes.

[0058] Reference Figure 3 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 a first electrode, a second electrode, and a separator inserted therebetween are wound around a winding axis to define a core and an outer surface. That is, the electrode assembly 10 used in this disclosure can be a 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, but is not limited to, a winding structure known in the art.

[0059] Reference Figure 3 The first electrode includes a first electrode current collector and a first electrode active material coated on one or both surfaces of the first electrode current collector. In the width direction of the first electrode (with... Figure 1 An uncoated portion, uncoated with the first electrode active material, is provided at one end of the battery cell 1 (parallel to the height direction shown). That is, the first electrode includes an uncoated portion at its long side end along the winding direction, exposed to the outside of the separator. Hereinafter, the uncoated portion serving as the first electrode tab will be referred to as the first uncoated portion 11. The first uncoated portion 11 is provided in the height direction (parallel to the height direction) of the electrode assembly 10 stored in the battery housing 20. Figure 1 The battery cell 1 shown is positioned at the top of the battery (parallel to the height direction). That is, the first electrode includes a first uncoated portion 11 on its long side end that is not coated with an active material layer and is exposed to the outside of the separator, and at least a portion of the first uncoated portion 11 itself serves as an electrode tab. The first uncoated portion 11 may be, for example, a negative electrode tab.

[0060] Reference Figure 3 The second electrode includes a second electrode current collector and a second electrode active material coated on one or both sides of the second electrode current collector. In the width direction of the second electrode (with... Figure 1The battery cell 1 shown (parallel in the height direction) has an uncoated portion at one end that is not coated with the second electrode active material. That is, the second electrode includes an uncoated portion at its long side end along the winding direction, where the active material is not coated and it is exposed to the outside of the separator. Hereinafter, the uncoated portion serving as the second electrode tab will be referred to as the second uncoated portion 12. The second uncoated portion 12 is located at the bottom of the electrode assembly 10 stored in the battery housing 20 in the height direction. That is, the second electrode includes a second uncoated portion 12 at its long side end where the active material layer is not coated and it is exposed to the outside of the separator, and at least a portion of the second uncoated portion 12 itself serves as an electrode tab. The second uncoated portion 12 can be, for example, a positive electrode tab.

[0061] Furthermore, in this disclosure, any active material known in the art can be used for the positive electrode active material coated on the positive electrode plate and the negative electrode active material coated on the negative electrode plate, without any limitation.

[0062] Reference Figures 1 to 3 The battery casing 20 can be configured as a generally cylindrical container with an opening on one side. The battery casing 20 may comprise a conductive metallic material. The side surface and the lower surface opposite the opening of the battery casing 20 can be integrally formed together. That is, the battery casing 20 may also have an opening on its upper side in the height direction and a closure on its lower side. The lower surface of the battery casing 20 can be configured to be generally flat. The battery casing 20 can receive the electrode assembly 10 through the opening formed on one side in the height direction. The battery casing 20 can also receive the electrolyte through the opening.

[0063] The side surface of the battery housing 20 can be configured as a cylindrical shape with a constant radius. Preferably, the entire area of ​​the side surface of the battery housing 20 can be configured as a cylindrical shape with a constant radius. For example, a conventional battery housing 20 may also include a rolled edge portion formed at an end adjacent to the opening and a press-fit portion formed on the rolled edge portion, while the battery housing 20 of this disclosure does not have a rolled edge structure and a press-fit structure formed on the side surface. That is, the battery housing 20 of this disclosure is not configured such that its side surface is recessed inward. In other words, the battery housing 20 of this disclosure is configured to have a constant radius over the entire area of ​​its side surface.

[0064] According to this structure, by eliminating the crimping and pressing structures from the cylindrical battery cell 1, various process errors that may be caused by the crimping and pressing structures can be prevented. Furthermore, the process can be simplified by eliminating the crimping, pressing, and shaping processes. Additionally, this prevents the increase of unusable space along the winding axis of the electrode assembly 10 due to the crimping and pressing structures in the battery, thus preventing a decrease in energy density. In other words, according to the structure of this disclosure, the energy density of the battery cell 1 can be improved.

[0065] In another embodiment of this disclosure, the battery housing 20 may be electrically connected to the first uncoated portion 11. Therefore, the battery housing 20 may have a first polarity.

[0066] Return to reference Figures 1 to 3 The housing cover 30 can be configured to cover an opening formed on one side of the battery housing 20. The housing cover 30 can be configured generally as a plate, for example. The housing cover 30 can be attached to the opening of the battery housing 20. More specifically, the housing cover 30 can be attached to the top of the battery housing 20. Preferably, the housing cover 30 can be secured to the top of the battery housing 20 by a coupling. For example, see... Figure 1 and Figure 3 The housing cover 30 can be positioned on the top edge of the opening of the battery housing 20. In this case, the battery housing 20 and the housing cover 30 can be joined together at the contact point between the top edge of the battery housing 20 and the housing cover 30. For example, the battery housing 20 and the housing cover 30 can be joined together by welding at the contact point between the top edge of the battery housing 20 and the housing cover 30. The battery housing 20 and the housing cover 30 can also be joined together by other connection methods besides welding, and the connection method is not limited to these. By joining the battery housing 20 and the housing cover 30, it can be ensured that the battery cell 1 is sealed.

[0067] The housing cover 30 can be made of a metallic material. Therefore, the housing cover 30 can be conductive. For example, the housing cover 30 can include aluminum. Since the battery housing 20 is also made of a conductive metal, the housing cover 30, which is connected to the battery housing 20, can also be configured to have the same polarity as the battery housing 20. For example, the housing cover 30 can be configured to have a first polarity.

[0068] In another embodiment of this disclosure, the housing cover 30 may have a through hole H in at least a portion of its area. In this case, the through hole H can be blocked by a recessed ball 40, described later. For example, the recessed ball 40 can be pressed into the through hole H. Thus, since the through hole H is blocked by the recessed ball 40, the sealing of the battery cell 1 can be ensured.

[0069] Furthermore, the through-hole H can be configured to discharge gases generated during the pre-charging process. That is, after a degassing process to discharge all gases generated during the pre-charging process through the through-hole H, the recessed ball 40 can be configured to connect to the through-hole H. Therefore, expansion of the battery cell 1 can be prevented.

[0070] In another aspect of this disclosure, the housing cover 30 may have a through hole H in the center. The through hole H can serve, for example, as an electrolyte injection port. The center of the through hole H may coincide with the center of the winding center hole H1 of the electrode assembly 10. That is, the through hole H of the housing cover 30 may be located above the winding center hole H1 of the electrode assembly 10 along the winding axis direction. Preferably, the diameter of the through hole H may be configured to be smaller than the diameter of the winding center hole H1 of the electrode assembly 10.

[0071] According to this structure, when the etched ball 40 is pressed into the through hole H and moves downward, it can prevent the etched ball 40 from damaging the electrode assembly 10 or the current collector 50 connected to the electrode assembly 10. That is, even if the etched ball 40 is pressed downward, the etched ball 40 is configured to enter the winding center hole H1 of the electrode assembly 10, so it will not affect the curved surface of the electrode assembly 10 or the electrode tab.

[0072] Similarly, the diameter of the etched ball 40 can be configured to be smaller than the diameter of the winding center hole H1 of the electrode assembly 10. The diameter of the etched ball 40 is preferably 70% or less of the diameter of the winding center hole H1 of the electrode assembly 10. For example, when the diameter of the winding center hole H1 is about 6 mm, the diameter of the etched ball 40 can be configured to be about 4 mm.

[0073] According to this structure, since the diameter of the engraved ball 40 is smaller than the winding center hole H1 of the electrode assembly 10, even if the engraved ball 40 is pressed down, it will enter the winding center hole H1 of the electrode assembly 10, so it will not affect the curved surface or electrode tab of the electrode assembly 10.

[0074] In another embodiment of this disclosure, reference is made to Figures 1 to 3 The concave ball 40 can be configured to be inserted into the through hole H.

[0075] For example, the etched ball 40 can be configured to have a generally spherical shape. Alternatively, as implemented in embodiments of this disclosure, it can be configured to have a slightly flattened spherical shape obtained by pressing up and down. By inserting the etched ball 40 into the through hole H of the housing cover 30, the sealing of the battery cell 1 can be ensured.

[0076] This structure eliminates the need for edge-rolling, pressing, and shaping processes, thus simplifying the manufacturing process. Furthermore, it prevents the increase in unproductive space along the winding axis of the electrode assembly 10 due to the edge-rolling and pressing structures, which would otherwise reduce energy density. In other words, according to the structure disclosed above, the energy density of the battery cell 1 can be improved.

[0077] Figure 4 This is a diagram showing the connection process of the engraved ball 40 and the housing cover 30 according to a comparative example of this disclosure.

[0078] For example, the concave sphere 40 according to the comparative example of this disclosure can be configured as a generally spherical structure with a convex outer surface. Figure 4 As shown, when the approximately spherical engraved ball 40 is pressed into the through hole H of the housing cover 30, the connection angle between the engraved ball 40 and the housing cover 30 becomes smaller due to excessive pressing. For example, when the engraved ball 40 according to the comparative example of this disclosure is pressed into the housing cover 30, the connection angle can be configured to be approximately acute. As described above, when the connection angle between the engraved ball 40 and the housing cover 30 is acute, when the connection point between the housing cover 30 and the engraved ball 40 is irradiated with a laser beam L, the welding energy cannot be sufficiently transferred to the exact point where the engraved ball 40 and the housing cover 30 are in contact. For example, refer to... Figure 4 When the point where the edge of the laser beam L intersects with the etched sphere 40 is P1, the point where the edge of the laser beam L intersects with the housing cover 30 is P2, and the point where the etched sphere 40 and the housing cover 30 meet is P3, the laser beam L irradiates the entire area including P1, P2, and P3. However, as the connection angle narrows, the most energy is transferred to points P1 and P2, which are the areas first reached by the laser beam L, while relatively less energy is transferred to P3. Therefore, pores are likely to form in the area where the etched sphere 40 and the housing cover 30 meet. More specifically, when the laser beam is focused on points P1 and P2, the areas near point P1 of the etched sphere 40 and the areas near point P2 of the housing cover 30 melt down to point P3. In this case, an air gap is formed at point P3, and the air in the air gap meets the molten substrate near point P1 of the etched sphere 40 and the molten substrate near point P2 of the housing cover 30. Therefore, the filling material solidifies into a porous structure. As a result, the pores in the porous structure can lead to cracks and deteriorate the sealing performance.

[0079] On the other hand, the above-mentioned problems can be solved by the concave ball 40 according to the embodiments of this disclosure. Figure 5 This is a diagram showing the shape of the recessed ball 40 according to an embodiment of the present disclosure.

[0080] Reference Figure 5The etched sphere 40 may have a groove G on its periphery. The groove G of the etched sphere 40 may also be recessed inwards. That is, the etched sphere 40 may be configured such that at least a portion of its periphery is recessed inwards. The recessed groove G is not limited to a specific shape. For example, as... Figure 5 As shown, the groove G can be configured to have a right-angled cross-section.

[0081] In embodiments of this disclosure, the edge region of the through hole H of the housing cover 30 can be configured to fit into the groove G. Preferably, the edge region of the through hole H of the housing cover 30 can be configured to press into the groove G.

[0082] In other words, the groove G can also fit into the through hole H of the housing cover 30. For example, both the engraved ball 40 and the housing cover 30 can be made of rigid metal, but when the engraved ball 40 is pressed into the housing cover 30, due to the elasticity of the relatively thin housing cover 30, the edge area of ​​the through hole H of the housing cover 30 can fit into the groove G provided in the engraved ball 40.

[0083] Preferably, the cross-sectional shape of the groove G can be configured to match the cross-sectional shape of the through hole H of the housing cover 30. For example, refer to Figure 3 The cross-section of the groove in the etched ball 40 can be configured to have a right-angled shape. In this case, the cross-section of the through hole H can be configured to have a right-angled shape that matches the cross-section of the groove. In this case, the sealing performance between the housing cover 30 and the etched ball 40 can be further improved.

[0084] According to the above structure, since the edge region of the through hole H of the housing cover 30 fits into the groove G, there is no gap between the housing cover 30 and the recessed ball 40. That is, it is difficult for an air gap to form between the housing cover 30 and the recessed ball 40. Therefore, it is possible to prevent the molten substrate from solidifying into a porous structure by interacting with the air gap during welding. As a result, according to the configuration of this disclosure, cracks caused by pores can be prevented at the welding position. Therefore, the sealing performance of the battery cell 1 can be improved.

[0085] Furthermore, according to the above configuration, the connection angle between the housing cover 30 and the engraved ball 40 can be ensured to be a predetermined angle or greater. Therefore, the ease of welding can be improved. More specifically, due to the wide connection angle between the housing cover 30 and the engraved ball 40, the formation of pores in the welding area can be minimized, thereby preventing cracks from forming in the welding area during laser welding. Therefore, the sealing performance between the housing cover 30 and the engraved ball 40 can be ensured. Additionally, the joint strength between the housing cover 30 and the engraved ball 40 can be ensured to be at a predetermined level or higher.

[0086] Return to reference Figure 5The groove G can be positioned outward in the axial direction of the battery cell 1, based on the center of the etched sphere 40. For example, Figure 5 The dashed line shown indicates a virtual line passing through the center of the engraved sphere 40. That is, the dashed line can be the center line of the engraved sphere 40.

[0087] The recessed sphere 40 may include a first region 41 located outward in the axial direction of the battery cell 1 based on a center line, and a second region 42 located inward in the axial direction of the battery cell 1 based on a center line. In this case, the groove G may be provided on the first region 41.

[0088] Preferably, that is, the volume of the etched sphere 40 positioned outward from the groove G of the battery cell 1 can be configured to be smaller than the volume of the etched sphere 40 positioned inward from the groove G of the battery cell 1. In other words, the volume of the first region 41 of the etched sphere 40 can be configured to be smaller than the volume of the second region 42 of the etched sphere 40.

[0089] This structure allows the laser beam L to more easily reach the contact area between the groove G and the through hole H when welding is performed between the etched ball 40 and the housing cover 30. In other words, the laser beam L is emitted in direct contact with the first region 41 of the etched ball 40. In this case, since the thickness of the first region 41 of the etched ball 40 is smaller than the thickness of the second region 42, the distance from the first region 41 of the laser beam L directly irradiating the etched ball 40 to the contact point between the groove G and the through hole H can be reduced. Therefore, the welding performance of the contact point between the groove G and the through hole H can be improved.

[0090] In another embodiment of this disclosure, the etched ball 40 can be configured to be conductive. That is, the etched ball 40 can include a metal. For example, the etched ball 40 can include an aluminum material. Therefore, the etched ball 40 can have the same polarity as the housing cover 30 it directly contacts. For example, the etched ball 40 can have a first polarity.

[0091] In embodiments of this disclosure, the housing cover 30 can be configured as a plate with a central region recessed inward. For example, the central region including the through hole H of the housing cover 30 can be recessed into the battery cell 1 to a predetermined depth. For example, a region with a predetermined radius from the center of the housing cover 30 can be recessed into the battery cell 1 to a predetermined depth.

[0092] According to the above structure, when the etched ball 40 is inserted into the housing cover 30, the etched ball 40 protrudes upward from the housing cover 30 by the height of the first region 41. In this case, if the central region of the housing cover 30 is recessed towards the interior of the battery cell 1 by the height of the first region 41, the etched ball 40, even if it protrudes upward from the housing cover 30 by the height of the first region 41, will not protrude beyond the outer side of the upper surface of the battery cell 1. Therefore, when the battery cell 1 is upright such that its upper surface faces the floor, it can remain horizontal.

[0093] In another embodiment of this disclosure, the recessed ball 40 may have a generally flat flat portion F in the region facing the outer side of the battery cell 1.

[0094] For example, refer to Figure 5 The upper part of the first region 41 of the concave sphere 40 may be provided with a flat portion F, wherein a certain area is configured to be flat. That is to say, the first region 41 may also be configured to be approximately flat.

[0095] With this configuration, the force applied when the etched ball 40 is pressed into place can be uniformly applied to the etched ball 40. Furthermore, with the above structure, since the thickness of the first region 41 of the etched ball 40 is reduced, the irradiation distance from the first region 41 of the direct irradiation laser beam L of the etched ball 40 to the contact point between the groove G and the through hole H can be decreased. Therefore, the welding performance of the contact point between the groove G and the through hole H can be improved.

[0096] Figure 6 This is a diagram showing the state of the recessed ball 40 before it is attached to the housing cover 30 according to an embodiment of the present disclosure, and Figure 7 This is a diagram illustrating the process of inserting the engraved ball 40 into the housing cover 30 according to an embodiment of the present disclosure.

[0097] Reference Figure 6 and Figure 7 The diameter of the engraved sphere 40 can be configured to be larger than the diameter of the through hole H. That is, since the diameter of the through hole H of the housing cover 30 is smaller than the diameter of the engraved sphere 40, therefore, as... Figure 6 As shown, before pressing the engraved ball 40 into the through hole of the housing cover 30, the engraved ball 40 is placed on the through hole of the housing cover 30.

[0098] According to the above configuration, since the diameter of the engraved ball 40 is larger than the diameter of the through hole H, once the engraved ball 40 is pressed and connected to the through hole H, it is difficult for the engraved ball 40 to separate from the through hole H.

[0099] In another embodiment, the diameter of the through hole H can be greater than or equal to the diameter of the groove G. Therefore, when the recessed ball 40 is pressed in the direction toward the housing cover 30, the housing cover 30 in the area surrounding the through hole H can be slightly deformed downwards due to the elasticity of the housing cover 30, and then return to its initial flat state due to the elasticity of the housing cover 30, so that the groove G can fit into the through hole H. That is, the edge region of the through hole H of the housing cover 30 can fit into the groove G. In this case, it is more preferable that the diameter of the groove G is configured to be the same as the diameter of the through hole H.

[0100] According to the above configuration, since the diameter of the groove G and the diameter of the through hole H are configured to be the same, it is possible to prevent the formation of a small gap between the groove G and the through hole H. Therefore, when the contact point between the groove G and the through hole H is irradiated with a laser beam L, welding can be performed smoothly. In other words, welding performance can be improved.

[0101] Figure 8 This is a diagram showing the connection angle between the recessed ball 40 and the housing cover 30 according to an embodiment of the present disclosure, and Figure 9 This is a diagram illustrating the process of performing laser welding when connecting the etched ball 40 and the housing cover 30 according to an embodiment of the present disclosure.

[0102] Reference Figure 8 and Figure 9 The connection angle formed by the housing cover 30 and the recessed ball 40 can be configured to approximately 90 degrees or greater. On the other hand, refer to... Figure 4 According to the comparative example of this disclosure, the connection angle formed by the housing cover 30 and the engraved ball 40 is configured to be less than approximately 90 degrees. As described above, if the connection angle formed by the housing cover 30 and the engraved ball 40 becomes smaller, the most energy can be transferred to points P1 and P2, which are the regions first reached by the laser beam L, and relatively less energy can be transferred to point P3. Therefore, pores are easily formed in the region where the engraved ball 40 and the housing cover 30 are in contact. As a result, cracks may occur due to these pores, which may degrade the sealing performance.

[0103] On the other hand, according to the shape of the engraved ball 40 in the embodiments of the present disclosure, the connection angle formed by the housing cover 30 and the engraved ball 40 can be approximately 90 degrees or greater. Preferably, according to the shape of the engraved ball 40 in the embodiments of the present disclosure, the connection angle formed by the housing cover 30 and the engraved ball 40 can be approximately 90 degrees or greater, i.e., an obtuse angle.

[0104] More specifically, the connection angle indicates the angle between the etched ball 40 and the tangent of the housing cover 30 at the intersection of the etched ball 40 and the housing cover 30. That is, the connection angle indicates the angle between the etched ball 40 and the tangent of the housing cover 30 at the point in the first region 41 starting from the groove G. In other words, according to the structure of the etched ball 40 of this disclosure, at the point in the first region 41 starting from the groove G, the slope of the tangent of the etched ball 40 is configured to be gentle. That is, at the point in the first region 41 starting from the groove G, the tangent of the etched ball 40 can be inclined towards the winding center of the electrode assembly 10. Preferably, the connection angle formed by the housing cover 30 and the etched ball 40 can be configured as an obtuse angle.

[0105] This structure prevents energy from being concentrated at points P1 and P2 where the laser beam L first arrives. In other words, since the connection angle between the housing cover 30 and the engraved sphere 40 is approximately 90 degrees or greater, sufficient energy can be transferred to the intersection point P3 where the engraved sphere 40 and the housing cover 30 meet. Therefore, pores are less likely to form in the area where the engraved sphere 40 and the housing cover 30 meet.

[0106] More specifically, according to the shape of the etched sphere 40 in the embodiments of this disclosure, the connection angle between the housing cover 30 and the etched sphere 40 exceeds approximately 90 degrees, preventing the formation of an air gap near point P3. In other words, according to the structure of this disclosure, since the connection angle between the housing cover 30 and the etched sphere 40 becomes an obtuse angle, the phenomenon of the laser beam focusing on points P1 and P2 can be prevented. Therefore, melting down to point P3 in the areas near point P1 of the etched sphere 40 and near point P2 of the housing cover 30 can be prevented. Therefore, the phenomenon of the substrate molten by welding solidifying into a porous structure can be effectively prevented. As a result, according to this disclosure, the generation of cracks caused by such pores can be prevented. Therefore, the sealing performance of the battery cell 1 can be improved.

[0107] In embodiments of this disclosure, the contact point between the housing cover 30 and the recessed ball 40 can be configured to have a weld bead formed by welding.

[0108] For example, refer to Figure 9The laser beam L can irradiate point P3, which is the intersection of the etched ball 40 and the housing cover 30. In this case, the laser beam L is configured to have a predetermined cross-sectional area, so that the laser beam L can not only be incident on point P3, but also on the surrounding area of ​​point P3. That is, the laser beam L can irradiate the area from point P1, where the edge of the laser beam L intersects with the etched ball 40, to point P2, where the edge of the laser beam L intersects with the housing cover 30. In this case, as described above, since the connection angle formed by the housing cover 30 and the etched ball 40 is approximately 90 degrees or greater, sufficient energy can be transferred to the intersection point P3 where the etched ball 40 and the housing cover 30 intersect. Therefore, a weld bead can be formed in the area including points P1, P2, and P3.

[0109] If the engraved ball 40 is pressed into the through hole H of the housing cover 30, and welding is not performed, the sealing performance at the contact point between the engraved ball 40 and the housing cover 30 may be relatively low. However, according to the above configuration, the bonding strength at the connection point between the engraved ball 40 and the housing cover 30 can be improved. In addition, the sealing performance at the connection point between the engraved ball 40 and the housing cover 30 can be improved.

[0110] Figure 10 This is a diagram specifically showing the contact area between the recessed ball 40 and the housing cover 30 according to an embodiment of the present disclosure.

[0111] In embodiments of this disclosure, the area where the housing cover 30 is attached to the recessed ball 40 can be subdivided. For example, refer to... Figure 10 On the outer surface of the housing cover 30, the area where the housing cover 30 begins to contact the recessed ball 40 can be defined as region A. Furthermore, on the outer surface of the housing cover 30, the area where the housing cover 30 is inserted into the groove G of the recessed ball 40 can be defined as region B. Next, the area where the inner surface of the through hole H of the housing cover 30 contacts the innermost point of the groove G of the recessed ball 40 can be defined as region C. On the inner surface of the housing cover 30, the area where the housing cover 30 is inserted into the groove G of the recessed ball 40 can be defined as region D. Finally, on the inner surface of the housing cover 30, the area where the housing cover 30 begins to contact the recessed ball 40 can be defined as region E.

[0112] Here, the laser beam L can directly irradiate region A. In this case, if the cross-sectional area of ​​the laser beam L is adjusted, region B may also be affected by the laser beam L. In some cases, if the power and irradiation depth of the laser beam L are adjusted, the influence of the laser beam L may also reach regions C, D, and E. Preferably, the power and irradiation depth of the laser beam L can be adjusted so that the laser beam L irradiates all regions A to E. That is, according to the above configuration, the first to fifth welds can be performed on each of regions A to E.

[0113] According to this configuration, the weld can be formed up to the inner surface of the housing cover 30. That is, even if the laser beam L irradiates this area from the outside of the battery cell 1, the laser beam L can affect all areas A to E, thus enabling welding between the housing cover 30 and the engraved ball 40 even on the inner surface of the housing cover 30. In other words, depending on the weld depth and angle, first to fifth seals can be performed on all areas A to E. Therefore, according to the above configuration, the joint strength at the connection point between the engraved ball 40 and the housing cover 30 can be improved. Furthermore, the sealing performance at the connection point between the engraved ball 40 and the housing cover 30 can be improved. Although the area where the housing cover 30 and the engraved ball 40 are joined is subdivided into five sections A to E for ease of explanation, this is not a limitation, and the area can be subdivided into more segments.

[0114] Return to reference Figure 2 and Figure 3 The battery cell 1 may also include a current collector 50, which is connected to the first uncoated portion 11 and electrically connected to the inner surface of the housing cover 30.

[0115] According to embodiments of the present disclosure, the current collector 50 is stored inside the battery housing 20, electrically connected to the electrode assembly 10, and also electrically connected to the battery housing 20. That is, the current collector 50 electrically connects the electrode assembly 10 to the battery housing 20. In other words, the current collector 50 may include a conductive metal.

[0116] The current collector 50 can also be configured generally as a plate. In this case, the lower surface of the plate can be electrically connected to the first uncoated portion 11. The upper surface of the plate can be electrically connected to the housing cover 30. Alternatively, the upper surface of the plate can be indirectly electrically connected to the housing cover 30 via, for example, a lead tab structure, rather than directly connected to the housing cover 30. That is, the current collector 50 can also be configured to electrically connect the housing cover 30 and the first uncoated portion 11. The current collector 50 and the first uncoated portion 11 and / or the housing cover 30 can be joined, for example, by welding.

[0117] The current collector 50 may have a current collector hole formed at a position corresponding to the winding center hole H1 formed approximately at the center of the electrode assembly 10. The winding center hole H1 and the current collector hole, which are in communication with each other, can be used as an insertion point for welding electrodes for welding between the terminal and the second current collector or between the terminal and the lead tab (not shown), or as a channel for laser beam irradiation.

[0118] Additionally, the current collector 50 may have at least one injection hole. For example, the injection holes may be arranged radially based on the orifices of the current collector 50. For example, multiple injection holes may be provided. In this case, the injection holes can improve the injection efficiency.

[0119] The battery cell 1 with the above configuration can be manufactured by the following steps: inserting the electrode assembly 10 through the opening of the battery housing 20; covering the opening of the battery housing 20 with the housing cover 30; and inserting a recessed ball 40 with a groove G on its periphery into the through hole H provided in the housing cover 30.

[0120] According to this manufacturing method, the gas generated during the pre-charging process can be smoothly discharged. That is, after a degassing process to discharge all the gas generated during the pre-charging process through the through-hole H, the etched ball 40 can be configured to connect to the through-hole H. Therefore, expansion of the battery cell 1 can be prevented. Furthermore, according to the above manufacturing method, electrolyte can be smoothly injected through the through-hole H provided in the housing cover 30. In addition, according to the above configuration, the sealing between the housing cover 30 and the etched ball 40 can be ensured. Furthermore, the bonding strength between the housing cover 30 and the etched ball 40 can be ensured to be at a predetermined level or higher.

[0121] Figure 11 This is a diagram showing a battery pack including battery cell 1 according to an embodiment of the present disclosure.

[0122] Reference Figure 11 The battery pack 3 according to an embodiment of the present disclosure includes a battery assembly electrically connected to a plurality of battery cells 1 according to an embodiment of the present disclosure, and a battery pack housing 2 for storing the battery assembly. For ease of explanation, components such as busbars, cooling units, and power terminals for electrical connection are omitted in the drawings of this disclosure. In addition, the battery pack 3 may also include various components of the battery pack 3 known at the time of filing of this disclosure, such as a BMS, a battery pack housing, relays, and current sensors.

[0123] Figure 12 It shows including Figure 11 Image of a vehicle with battery pack 3.

[0124] Reference Figure 12 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 may include 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. In addition to the battery cell 1 or the battery pack 3, vehicle 5 according to the present disclosure may also include various other components included in the vehicle. For example, in addition to the battery cell 1 of the present disclosure, vehicle 5 according to the present disclosure may also include a vehicle body, a motor, a control device such as an ECU (electronic control unit), etc.

[0125] Although terms such as up and down indicating direction are used in this specification, it will be apparent to those skilled in the art to which this disclosure pertains that these terms are merely for ease of interpretation with reference to the accompanying drawings and may vary depending on the position of the target object or the observer's position.

[0126] As described above, although this disclosure has been described with reference to limited embodiments and drawings, this disclosure is not limited thereto, and various modifications and variations can be made by those skilled in the art without departing from the technical concept of this disclosure and the equivalent scope of the described claims.

[0127] [Explanation of reference numerals in the attached figures]

[0128] 5 vehicles

[0129] 3 Battery Pack

[0130] 2. Battery pack casing

[0131] 1. Battery cell

[0132] 10 Electrode Assembly

[0133] 11 First Uncoated Section

[0134] 12 Second Uncoated Section

[0135] H1 winding center hole

[0136] 20 Battery casing

[0137] 30. Housing cover

[0138] H Through Hole

[0139] 40. Engraved sphere

[0140] G groove

[0141] 41 First District

[0142] 42 Second Region

[0143] F Flat section

[0144] D Insertion depth

[0145] 50 current collector

[0146] L laser beam

Claims

1. A battery cell, the battery cell comprising: An electrode assembly that defines a core and an outer surface by winding a first electrode and a second electrode and a diaphragm inserted between the first electrode and the second electrode around a winding axis, wherein 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 tab. A battery housing configured to receive the electrode assembly through an opening formed on one side; A housing cover, configured to cover the opening and having a through hole in the center; and A recessed ball, which is configured to be inserted into the through hole.

2. The battery cell according to claim 1, in, The side surface of the battery casing has a cylindrical shape with a constant radius.

3. The battery cell according to claim 1, in, The housing cover has a plate shape and is configured to attach to the opening of the battery housing.

4. The battery cell according to claim 1, in, The diameter of the through hole is smaller than the diameter of the winding center hole of the electrode assembly.

5. The battery cell according to claim 1, in, The diameter of the etched sphere is smaller than the diameter of the winding center hole of the electrode assembly.

6. The battery cell according to claim 1, in, The etched sphere has grooves formed on its periphery.

7. The battery cell according to claim 6, in, The edge region of the through hole in the housing cover fits into the groove.

8. The battery cell according to claim 6, in, The groove is located in the region of the battery cell in the axial direction outward, based on the center of the etched sphere.

9. The battery cell according to claim 6, in, Based on the groove, the volume of the etched sphere located outside the battery cell is smaller than the volume of the etched sphere located inside the battery cell.

10. The battery cell according to claim 1, in, The connection angle between the housing cover and the recessed ball is greater than 90 degrees.

11. The battery cell according to claim 1, in, A weld bead is formed by welding at the contact point between the housing cover and the recessed ball.

12. The battery cell according to claim 11, in, The weld bead is formed up to the inner surface of the housing cover.

13. A method for manufacturing a battery cell, the method comprising the following steps: The electrode assembly is inserted through the opening in the battery casing; Cover the opening of the battery casing with a casing cover; as well as A concave ball with grooves formed on its periphery is inserted into a through hole formed in the housing cover.

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

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

Images