Battery cell and method for manufacturing battery cell

Description

1 / 49 BATTERY CELL AND METHOD FOR MANUFACTURING BATTERY CELL TECHNICAL FIELD

[001] The present invention relates to a battery cell and a method for manufacturing the battery cell.

[002] The present invention relates to a battery cell, and a battery pack and a vehicle that includes the same.

[003] This application is based on and claims priority from Korean Patent Application No. 10-2023-0101856, filed on August 3, 2023 with the Korean Intellectual Property Office, the description of which is incorporated herein by reference in its entirety. Furthermore, this application is based on and claims priority from Korean Patent Application No. 10-2024-0102303, filed on August 1, 2024 with the Korean Intellectual Property Office, the description of which is incorporated herein by reference in its entirety. BACKGROUND OF THE TECHNIQUE

[004] The process for manufacturing a battery cell using a cylindrical container includes forming a circular bottom and a cylindrical side wall member connected to it by deep drawing using a sheet metal, storing an electrode assembly in it, and then covering and finishing an open end of the side wall member with a cap.

[005] Meanwhile, a collector plate is provided at one end facing the open end, between both axial ends of the electrode assembly, so as to make electrical contact with the electrode tab of the electrode assembly. The collector plate is connected to the cover or side wall member by welding or similar means, so as to be electrically connected to the cover or side wall member.

[006] The collector plate must remain in close contact with Petition 870250093429, dated 10 / 13 / 2025, page 8 / 94 2 / 49 the cover or side wall member in the welding process of the collector plate to the cover or side wall member and, for this purpose, a jig is required for close contact between the collector plate and the cover or between the collector plate and the side wall member and, in addition, a mask is required to expose the welding area.

[007] In order to place the collector plate in close contact with the cover or side wall member using the mask or jig, a space to receive the mask or jig must be provided inside the container. However, this space remains empty after the mask or jig is removed, causing a problem in which the internal space of the container is not efficiently used. This makes it difficult to design to increase the energy density per unit volume of the container.

[008] In addition, in order to close the open end of the cylindrical container, unit volume, a process for electrically connecting the collector plate to the lid or to the side wall member and a process for connecting the lid to the side wall member are performed, respectively. Such an increase in the number of processes reduces the production efficiency of the cylindrical battery cell and increases the production cost.

[009] Therefore, it is necessary to provide a method capable of efficiently coupling the collector plate to the container and efficiently closing the open end of the container, and / or a method capable of achieving the efficiency of the welding process and the reliable strength of the welding when performing the welding process of the components. INVENTION TECHNICAL PROBLEM

[0010] The present invention is designed to solve the problems of the relevant art and, therefore, the present invention is directed to providing a welding structure for a battery container, a Petition 870250093429, dated 10 / 13 / 2025, page 9 / 94 3 / 49 collector plate and a lid, which excludes a separate welding mask or jig, thereby efficiently utilizing the internal space of the vessel when welding the collector plate provided at the open end of the vessel to the vessel and allowing the design to increase the energy density per unit volume of the vessel and a battery cell to which the welding structure is applied.

[0011] According to another aspect, the present invention is also to provide a welding structure for a battery container, a collector plate and a lid, which improves the stability of the welding process, giving the functions of mask and template to the container, the collector plate and the lid, and a battery cell to which the welding structure is applied.

[0012] According to another aspect, the present invention is also to provide a welding structure for a battery container, a collector plate and a lid, which integrates a welding process of the collector plate to the container, and a welding process of the lid to the side wall member in a single welding process, thereby increasing the production efficiency of a cylindrical battery cell and reducing the production cost, and a battery cell to which the welding structure is applied.

[0013] According to another aspect, the present invention is also to provide a welding structure of a container, a collector plate and a lid, which minimizes the generation of welding heat while welding the container, the collector plate and the lid together, thereby simplifying the assembly process of the collector plate and the lid without adversely affecting the electrode assembly, and a battery cell to which the welding structure is applied.

[0014] According to another aspect, the present invention is also to provide a welding structure for a container, a collecting plate and a lid capable of improving the seal between the re Petition 870250093429, dated 10 / 13 / 2025, page 10 / 94 4 / 49 container and lid while welding the container, collector plate and lid together, and a battery cell to which the welding structure is applied.

[0015] According to another aspect, the present invention is also to provide a welding structure for a container, a collector plate and a lid capable of ensuring weldability, increasing the stability of the process and ensuring the durability of the welding, and a battery cell to which the welding structure is applied.

[0016] According to another aspect, the present invention is also to provide a welding structure of a container, a collector plate and a lid capable of performing a stable and fast weld when welding the container, collector plate and lid together to be suitable for mass production, and a battery cell to which the welding structure is applied.

[0017] The technical problems that the present invention seeks to solve are not limited to the problems mentioned above, and other objects and advantages of the present invention not mentioned above will be understood from the description below and will be more clearly understood from the embodiments of the present invention. Furthermore, it will be easily understood that the objects and advantages of the present invention can be realized by the means shown in the appended claims and combinations thereof. TECHNICAL SOLUTION

[0018] The above technical problems can be solved by forming a first weld portion (triple weld portion) in which the container, the collector plate and the lid are intermittently or partially welded together during a seam welding process to seal the container, and by forming a second weld portion (double weld portion) in which at least the container Petition 870250093429, dated 10 / 13 / 2025, page 11 / 94 5 / 49 and the cover are welded together at the remaining seam weld section.

[0019] This can be implemented by forming a second weld portion by means of radiation from a laser beam in a scanning mode, so as to seam weld at least the container and the lid together along the contact portion of the container and the lid that extends in the circumferential direction and by triple welding of the container, the collector plate and the lid together in the section forming a first weld portion with a laser energy density and / or a scanning speed which are different from those in the section forming the second weld portion.

[0020] Consequently, it is possible to suppress the generation of excessive welding heat and reliably seal the container while maintaining the simplicity of the welding process for the container, collector plate, and lid.

[0021] Energy density control or scan speed control can be performed in order to maintain consistency in the generation, propagation and solidification of the molten pool, so that the propagation of the molten pool can be smoothly performed even at the boundary between the first weld portion and the second weld portion.

[0022] Therefore, seam welding can be performed continuously, and the molten pool propagation can be smoothly performed only in the section where triple welding is required for electrical connection with the electrode, so that the welding range is varied, thereby maintaining the consistency of the generation, propagation and solidification of the molten pool during the molten pool propagation process, and the molten pool propagation can be smoothly performed, allowing a reliable seal without any defects.

[0023] The present invention to solve the above problems Petition 870250093429, dated 10 / 13 / 2025, page 12 / 94 6 / 49 described can be applied to a battery cell that includes an electrode assembly, a collector plate electrically connected to the electrode assembly, and a container that houses the electrode assembly and the collector plate.

[0024] The container includes a lower member, a side wall member connected to the lower member and extending in an axial direction, and a cover configured to cover an open end provided at an axial end of the side wall member.

[0025] The electrode array may be in the form of a jelly roll wrapped around a predetermined geometric axis.

[0026] An electrode tab may be provided at one end facing the open end, between both axial ends of the electrode assembly, and the collector plate may be connected to the electrode tab.

[0027] The collector plate may include an electrode tab connection portion that is in electrical contact with the electrode tab.

[0028] The collector plate includes a container connection portion that is in electrical contact with the container.

[0029] The container connection portion and the electrode tab connection portion can be electrically connected.

[0030] The container connection portion may be arranged radially further out than the electrode tab connection portion.

[0031] First weld portions in which an edge of the open end of the side wall member, an edge of the cover and the container connection portion are welded together are formed in multiple positions so as to be spaced from each other along the circumferential direction.

[0032] The first portions of solder may be intermittently formed in the process of forming a second portion of solder. Petition 870250093429, dated 10 / 13 / 2025, page 13 / 94 7 / 49 of, in which at least one edge of the open end of the side wall member and one edge of the cover are welded together by seam welding.

[0033] The first portions of solder may be provided in four or more locations.

[0034] The first weld portions can be provided in 24 or more locations.

[0035] The second weld portion may be provided to be connected to the first weld portion in the circumferential direction.

[0036] The second weld portion may be provided between neighboring first weld portions in the circumferential direction.

[0037] The first weld portion and the second weld portion can be formed by laser welding.

[0038] The first weld portion and the second weld portion can be formed by common scan welding, that is, by a scan weld.

[0039] The circumferential length of the first weld portion can be approximately 0.1 mm to 6 mm.

[0040] Consequently, the generation of welding heat to form the first portion of the weld can be suppressed.

[0041] The output of a laser beam in the section that forms the first weld portion may be greater than the output of a laser beam in the section that forms the second weld portion.

[0042] The energy density of a laser radiation area of ​​the section that forms the first weld portion may be greater than the energy density of a laser radiation area of ​​the section that forms the second weld portion.

[0043] The laser scanning speed in the section that forms the first weld portion and the laser scanning speed in the section that forms the second weld portion can be constant. Petition 870250093429, dated 10 / 13 / 2025, page 14 / 94 8 / 49

[0044] The laser scanning speed in the section that forms the second weld portion may be lower than the laser scanning speed in the section that forms the first weld portion.

[0045] The scanning speed relative to the laser output in the section that forms the first weld portion may be lower than the scanning speed relative to the laser output in the section that forms the second weld portion.

[0046] The scanning speed relative to the energy density in the laser radiation area to form the first weld portion may be lower than the scanning speed relative to the energy density in the laser radiation area to form the second weld portion.

[0047] The depth at which the first weld portion is formed in the axial direction may be greater than the depth at which the second weld portion is formed.

[0048] The cross-sectional area of ​​the first weld portion may be larger than the cross-sectional area of ​​the second weld portion when viewed in the circumferential direction.

[0049] In addition, third weld portions, in which an edge of the open end of the side wall member and an edge of the cap are welded together, can be formed to be spaced from each other in the circumferential direction.

[0050] The third weld portion may be a preliminary weld portion.

[0051] The first weld portion and the second weld portion can be the main weld portions. If the third weld portion is formed by preliminary welding before the main welding to form the first weld portion and the second weld portion, the gap caused by the tolerance of the container and lid components can be fixed, and resistance to deformation can be provided. Petition 870250093429, dated 10 / 13 / 2025, page 15 / 94 9 / 49 thermal stress that occurs during the welding process.

[0052] The main weld portion can be formed over the preliminary weld portion. Consequently, the preliminary weld portion can overlap the main weld portion.

[0053] The welding depth and / or welding area of ​​the third weld section may be smaller than those of the second weld section.

[0054] The welding depth and / or welding area of ​​the second weld portion may be smaller than those of the first weld portion.

[0055] The section where the third weld portion is formed in the circumferential direction can be configured so as not to overlap the section where the first weld portion is formed. Consequently, the laser beam does not encounter the boundary surface of the third weld portion, i.e., the preliminary weld portion, in the section where the triple welding is performed, so that the molten pool can be stably propagated.

[0056] The section where the third weld portion is formed in the circumferential direction can be configured to overlap the section where the second weld portion is formed. Since there is a normal relationship between the preliminary weld and the main weld, the sealing reliability of the second weld portion can be ensured.

[0057] The container connection portion may include a first portion in contact with the side wall member and a second portion in contact with the lid.

[0058] The first portion may include an external contact surface that faces the internal surface of the side wall member in the radial direction. A first section, which is at least a portion of the axial section of the external contact surface, may contact the internal surface of the side wall member. Petition 870250093429, dated 10 / 13 / 2025, page 16 / 94 10 / 49

[0059] The second portion may include a cover contact surface that faces and contacts the inner surface of the cover in the axial direction.

[0060] The cover may include an external bonding surface that faces the internal surface of the side wall member in the radial direction.

[0061] The outer bonding surface of the cover may face and contact the inner surface of the side wall member in the radial direction.

[0062] The cover may include a collector plate contact surface defined by the axially inner surface of the cover and axially facing and being in contact with the cover contact surface of the collector plate container connection portion.

[0063] The outer bonding surface of the cover can be arranged axially outward from the collector plate contact surface and arranged radially outward.

[0064] The cover may include a sloped surface arranged inward toward the collector plate contact surface in the radial direction on the axially inner surface of the cover and extending axially inward as it approaches the inner side in the radial direction.

[0065] The inclined surface may contact at least one corner portion of an axially external end and one radially internal end of the collector plate's container connection portion.

[0066] Consequently, the centers of the collector plate and the lid can be aligned.

[0067] Consequently, the axially external end of the container connection portion can receive a force acting outward in the radial direction.

[0068] The outer diameter of the first section of the surface of Petition 870250093429, dated 10 / 13 / 2025, page 17 / 94 11 / 49 The outer contact surface is larger than the inner diameter of the inner surface of the side wall member in contact with it. Consequently, the first section of the outer contact surface can be forcibly pressed against the side wall member.

[0069] The collector plate may be softer than the side wall member of the container.

[0070] At one axial end, the inner diameter of the side wall member can be extended.

[0071] The side wall member may include an internal diameter expansion portion in which the internal diameter of the side wall member is increased, a first internal surface provided inward in the axial direction of the internal diameter expansion portion and a second internal surface provided outward in the axial direction of the internal diameter expansion portion and having an internal diameter larger than that of the first internal surface.

[0072] The outer contact surface of the container connection portion may face and come into contact with the second inner surface.

[0073] The outer bonding surface of the cover may face or come into contact with the second inner surface.

[0074] The outer diameter of the first section of the outer contact surface may be larger than the inner diameter of the first inner surface and may match or be smaller than the inner diameter of the second inner surface.

[0075] The container connection portion can be configured to extend axially outward from a folded portion obtained by folding the collector plate, extending outward in the radial direction, outward in the axial direction.

[0076] If the outer diameter of the outer contact surface is defined to be slightly larger than the inner diameter of the se Petition 870250093429, dated 10 / 13 / 2025, page 18 / 94 12 / 49 second inner surface, the outer contact surface can be pressed against the second inner surface during the process of inserting the collector plate, so that the outer contact surface and the second inner surface can be in close radial contact.

[0077] As a result, in the state where the collector plate is inserted, the outer diameter of the outer contact surface can match the inner diameter of the second inner surface.

[0078] The outer bonding surface of the cover and the axial end of the inner surface of the side wall member, which face each other in the radial direction, may be axially exposed outwards.

[0079] The first weld portion and the second weld portion can be formed by a laser beam irradiated from the axially external side of the battery cell to the external bonding surface of the cover and the axial end of the inner surface of the side wall member.

[0080] In this case, as the outer contact surface of the collector plate, which is axially arranged inwards into the lid, can face and come into contact with the inner surface of the side wall member, the laser beam can be prevented from being directly irradiated into the internal space of the container.

[0081] The internal diameter expansion portion can prevent the laser, which may be irradiated within the gap between the side wall member and the collector plate, from penetrating the interior.

[0082] The collector plate may have higher thermal conductivity than the side wall member. Consequently, the heat generated when forming the first weld portion and the second weld portion may be dispersed to the electrode assembly through the collector plate, thus preventing the welding heat from damaging the separation. Petition 870250093429, dated 10 / 13 / 2025, page 19 / 94 13 / 49 electrode assembly sensor.

[0083] A projection may be provided at one axial end of the side wall member so as to project further outward than the cap in the axial direction.

[0084] The overhang can be fused to flow into a weld portion of the inner surface of the side wall member and into the outer bonding surface during the process of forming the first weld portion and the second weld portion. Consequently, the weld portion can be formed over the entire outer bonding surface of the cap in the axial direction, despite the differences between the welding processes.

[0085] The protrusion can be fused in the process of forming the first weld portion and the second weld portion in the main weld. Consequently, the height of the battery cell can be defined by the surface of the cover and, as a result, the height dimension of the battery cell can be managed at a constant level.

[0086] The present invention provides a method for manufacturing the battery cell described above.

[0087] The battery cell includes a container comprising a lower member, a side-wall member connected to the lower member and extending in the axial direction, and a cap covering an open end provided at an axial end of the side-wall member, and an electrode assembly housed within the container.

[0088] The method for manufacturing the battery cell may include a preparatory step of connecting a collector plate to an electrode tab provided at one end facing the open end, between both axial ends of the electrode assembly.

[0089] The manufacturing method includes a first step of inserting the collector plate into the container and placing a contact surface ex Petition 870250093429, dated 10 / 13 / 2025, page 20 / 94 14 / 49 a portion of a container connection provided on a radially outer edge of the collector plate in contact with an inner surface of the side wall member.

[0090] The manufacturing method includes a second step of covering the open end of the side wall member with the cap, causing an external bonding surface provided on an edge of the cap to face the internal surface of the side wall member in a radial direction, and bringing the collector plate contact surface into contact with a collector plate cap contact surface in the axial direction.

[0091] The manufacturing method includes a third step of forming a weld portion in a contact portion between the inner surface of the side wall member and an outer bonding surface of the cover.

[0092] In this case, the overhang of the side wall member, which projects further outward in the axial direction than the cover, can be fused to flow into the weld portion between the inner surface of the side wall member and the outer bonding surface of the cover.

[0093] In the third stage, a laser beam is irradiated onto a bumping portion of the inner surface of the side wall member and the outer bonding surface of the cover in the axial direction from an axially external side, while continuously irradiating the laser beam along the circumferential direction and performing the welding so that a first weld portion in which the inner surface of the side wall member, the outer bonding surface of the cover and the container connection portion of the collector plate are welded together alternates with a second weld portion in which at least the inner surface of the side wall member and the outer bonding surface of the cover are welded together.

[0094] In this case, the first portion of solder and the second portion Petition 870250093429, dated 10 / 13 / 2025, page 21 / 94 15 / 49 of the weld can be alternately formed so that the circumferential length of the second weld portion is longer than the circumferential length of the first weld portion.

[0095] A preliminary welding step may also be performed between the second and third steps.

[0096] In the preliminary welding stage, a plurality of third weld portions, in which an edge of the open end of the side wall member and an edge of the cover are welded, can be formed to be spaced from each other in the circumferential direction.

[0097] In the third stage, the intensity of a laser beam irradiated onto a section for welding the first weld portion or the energy density of a laser radiation area of ​​the same may be stronger or greater than the intensity of a laser beam irradiated onto a section for welding the second weld portion or the energy density of a laser radiation area of ​​the same.

[0098] In the third stage, the speed of movement of a radiation area of ​​the laser beam irradiated on the section to weld the first weld portion and the speed of movement of a radiation area of ​​the laser beam irradiated on the section to weld the second weld portion can be constant.

[0099] In the third stage, the scanning speed relative to the laser beam output at the section to form the first weld portion may be lower than the scanning speed relative to the laser beam output at the section to form the second weld portion.

[00100] In the third stage, the scanning speed in relation to the energy density of the laser radiation area to form Petition 870250093429, dated 10 / 13 / 2025, page 22 / 94 16 / 49 the first weld portion may be smaller than the scanning speed relative to the energy density of the laser radiation area to form the second weld portion. ADVANTAGEOUS EFFECTS

[00101] According to the present invention, it is possible to ensure the electrical connection of the collector plate and the sealing of the container, suppressing the generation of welding heat, compared with welding the entire circumferential section of the container, the collector plate and the lid together.

[00102] In another aspect, according to the present invention, it is possible to sufficiently implement a required internal resistance and reliably seal the container while suppressing the generation of welding heat.

[00103] In another aspect, according to the present invention, it is possible to ensure weldability, stability and durability during welding of the side wall member, cover and collector plate together.

[00104] In another aspect, according to the present invention, it is possible to significantly reduce the assembly work of the battery cell by welding the side wall member, the cover and the collector plate together.

[00105] In another aspect, according to the present invention, since welding is not required inside the container, the risk of foreign substances, such as welding spatter, penetrating the electrode assembly and causing defects can be eliminated.

[00106] In another aspect, according to the present invention, the volume of the electrode assembly housed within the container can be fixed to the maximum, thereby increasing the energy density of the battery cell.

[00107] In addition to the effects described above, the specific effects of Petition 870250093429, dated 10 / 13 / 2025, page 23 / 94 17 / 49 of the present invention will be described in the detailed description of the invention below. BRIEF DESCRIPTION OF THE DRAWINGS

[00108] Figure 1 is a perspective view of a cylindrical battery cell of one embodiment.

[00109] Figure 2 is an exploded perspective view of an electrode array which has not yet been wound, housed inside a container in Figure 1.

[00110] Figure 3 is a perspective view of the electrode assembly of Figure 2 in a laminated state, which has not yet been wound.

[00111] Figure 4 is a perspective view of an electrode assembly mounted in a cylindrical jelly-roll form by winding the laminate in Figure 3.

[00112] Figure 5 is a perspective view illustrating a state in which a first collector plate is attached to an electrode tab of a first electrode in an electrode array.

[00113] Figure 6 is a perspective view illustrating a state in which a second collector plate is attached to an electrode tab of a second electrode in an electrode array.

[00114] Figure 7 is a side cross-sectional view illustrating a process for storing an electrode array with an attached collector plate inside a container.

[00115] Figure 8 is a side cross-sectional view illustrating a process of connecting a first collector plate of an electrode array housed in a container to a first electrode terminal.

[00116] Figure 9 is a side cross-sectional view illustrating the process of covering an open end of a container in which an electrode array is housed with a lid. Petition 870250093429, dated 10 / 13 / 2025, page 24 / 94 18 / 49

[00117] Figure 10 is a side cross-sectional view illustrating the state in which one open end of a container in which an electrode array is housed is covered with a lid.

[00118] Figure 11 is an enlarged view of the rectangular area in Figure 9.

[00119] Figure 12 is an enlarged view of the rectangular area in Figure 10.

[00120] Figure 13 is an enlarged view of the portion where the collection plate, lid, and container of Figure 12 meet.

[00121] Figure 14 is a plan view illustrating the state in which a lid and a container are preliminarily welded together.

[00122] Figure 15 is a cross-sectional view illustrating the configuration in Figure 14.

[00123] Figure 16 is a plan view illustrating the state in which a lid and a container are permanently welded together.

[00124] Figure 17 is a cross-sectional view illustrating the configuration in Figure 16.

[00125] Figure 18 is a cross-sectional view illustrating the configuration in Figure 16.

[00126] Figure 19 is a cross-sectional view illustrating the configuration in Figure 16.

[00127] Figure 20 is an enlarged view illustrating an example modified from the container in Figure 12.

[00128] Figure 21 is a flowchart that illustrates an example of a process for manufacturing a battery cell according to one embodiment.

[00129] Figures 22 and 23 illustrate a battery pack to which the battery cell of the embodiment is applied and a vehicle equipped with such a battery pack. BEST WAY Petition 870250093429, dated 10 / 13 / 2025, page 25 / 94 19 / 49

[00130] The aforementioned purposes, features, and advantages will be described in detail below with reference to the accompanying drawings, so that persons skilled in the art to which the present invention pertains may easily implement the technical ideas of the present invention. In describing the present invention, descriptions of known related technologies, which may obscure the subject matter of the present invention, will be omitted. Hereafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In the drawings, the same reference numbers are used to indicate the same or similar elements.

[00131] Although first, second, etc. are used to describe various elements, these elements are not limited to these terms. These terms are only used to distinguish one member from another element, and unless otherwise stated, a first member may also be a second element.

[00132] Throughout the specification, unless otherwise stated, the respective elements may include a single element or a plurality of elements.

[00133] From now on, the configuration in which an element is arranged in the upper (or lower) portion or on top (or bottom) of a target element may indicate that the element may be arranged in contact with the upper (or lower) surface of the target element and that another element may be interposed between the target element and the element arranged on top (or bottom) of the target element.

[00134] Additionally, the expression an element is 'connected to', 'coupled to' or 'in contact with' another element should be understood to mean that the elements may be directly connected, coupled or in contact with each other, and that another element may be interposed between the elements or that the elements may be Petition 870250093429, dated 10 / 13 / 2025, p. 26 / 94 20 / 49 connected to, coupled to, or in contact with each other through other elements.

[00135] As used herein, singular expressions include plural expressions unless clearly stated otherwise. In this document, terms configured to have or include should not be interpreted as necessarily including all the various elements or steps described in the specification, and should be interpreted in such a way that some of the elements or steps may be excluded or that additional elements or steps may be additionally included.

[00136] Throughout the specification, A and / or B, unless otherwise stated, may denote A, B, or A and B, and C to D, unless otherwise stated, may denote equal to or greater than C and equal to or less than D.

[00137] In the description of the embodiments, the axial direction indicates a direction in which a geometric winding axis of an electrode array wound in a jelly-roll form extends, and the radial direction indicates a direction of approach (centripetal direction) or recession (centrifugal direction) from the geometric winding axis, and the circumferential direction indicates a direction that encircles the geometric winding axis.

[00138] Hereafter, the embodiments of a battery cell to which a welding structure of the present invention is applied will be described in detail, with reference to Figures 1 to 19.

[00139] The battery cell in this configuration can be, for example, a cylindrical battery cell that has a form factor ratio (defined as the ratio between the diameter (Φ) and the height (H) of the cylindrical battery cell) greater than approximately 0.4.

[00140] Here, the form factor ratio denotes a value that indicates the diameter and height of the cylindrical battery cell. The battery cell Petition 870250093429, dated 10 / 13 / 2025, page 27 / 94 A 21 / 49 cylindrical cell could be, for example, a 46110 cell, a 48750 cell, a 48110 cell, a 48800 cell, a 46800 cell, a 4690 cell, or a 4695 cell. In the form factor ratio value, the first two digits indicate the cell diameter, the next two digits indicate the cell height, and the last digit, 0, indicates that the cell's cross-section is circular.

[00141] The battery cell may be a cylindrical battery cell that has a diameter of approximately 46 mm, a height of approximately 110 mm, and a form factor ratio of 0.418.

[00142] According to another embodiment, the battery cell may be a cylindrical battery cell that has a diameter of approximately 48 mm, a height of approximately 75 mm and a form factor ratio of 0.640.

[00143] According to another embodiment, the battery cell may be a cylindrical battery cell that has a diameter of approximately 48 mm, a height of approximately 110 mm and a form factor ratio of 0.418.

[00144] According to another embodiment, the battery cell may be a cylindrical battery cell that has a diameter of approximately 48 mm, a height of approximately 80 mm and a form factor ratio of 0.600.

[00145] According to another embodiment, the battery cell may be a cylindrical battery cell that has a diameter of approximately 46 mm, a height of approximately 80 mm and a form factor ratio of 0.575.

[00146] The present invention can also be applied to battery cells that have a form factor ratio of approximately 0.4 or less, such as an 18650 cell, a 21700 cell, and the like. In the case of the 18650 cell, the diameter is approximately 18 mm, the height is approximately 65 mm, and the form factor ratio is approximately 0.4. Petition 870250093429, dated 10 / 13 / 2025, page 28 / 94 22 / 49 ma is 0.277. In the case of cell 21700, the diameter is approximately 21 mm, the height is approximately 70 mm, and the form factor ratio is 0.300.

[00147] The battery cell of this embodiment may include an electrode assembly 20, collector plates 31 and 32 electrically connected to the electrode assembly 20 and a container 10 that accommodates the electrode assembly 20 and the collector plates 31 and 32.

[00148] The container 10 may include a lower member 12, a side wall member 11 connected to the lower member 12 and extending in the axial direction, and a cover 16 covering an open end provided at an axial end of the side wall member 11. Herein, the axial direction may indicate a direction parallel to the geometric winding axis of the electrode assembly 20 of the present invention.

[00149] The lower member 12 may have the shape of a disc with a hole formed in the center. The side wall member 11 may have the shape of a circular tube. That is, the side wall member 11 may have a hollow cylindrical shape.

[00150] The lower member 12 and the side wall member 11 can be formed as one piece. The lower member 12 and the side wall member 11 can be manufactured by forming a nickel-plated sheet metal on the steel surface through a deep drawing process, and trimming the front end of the side wall member 11 with a punch, while holding it with a sheet support. Furthermore, the material of the container 10 is not limited to this.

[00151] A first electrode terminal 13 can be fitted into the hole. The first electrode terminal 13 can be fixed to the lower member 12 by riveting. A gasket 14 can be interposed between the first electrode terminal 13 and the container 10. The gasket 14 can be Petition 870250093429, dated 10 / 13 / 2025, page 29 / 94 23 / 49 interposed between the first electrode terminal 13 and the lower member 12 to seal the portion between the inside and outside of the container 10, thereby preventing leakage of the electrolyte and electrically isolating the first electrode terminal 13 and the lower member 12 from each other.

[00152] However, the method of connecting the first electrode terminal 13 and the lower member 12 is not limited to this. For example, various other fastening methods, such as a screw and nut joining method, the glass sealing method or a chrome & PP-MAH coating thermal bonding method, can also be applied, provided they are able to seal the portion between the first electrode terminal 13 and the lower member 12 and electrically isolate the first electrode terminal 13 and the lower member 12 from each other.

[00153] The first electrode terminal 13 may have a first polarity, and the container 10 may have a second polarity opposite to the first polarity. That is, the lower member 12 of the container 10, the side wall member 11 connected to it, and the lid 16 connected to the side wall member 11, which will be described later, may all have a second polarity.

[00154] Consequently, the battery cell can have either the first electrode terminal 13 or the second electrode terminal 15 located at the axial end, i.e., the closed end, where the lower member 12 is provided. Then, the battery cell can have either a busbar connected to the first electrode terminal 13 or a busbar connected to the second electrode terminal 15, which are positioned at the top of the battery cell.

[00155] In one example, the first electrode terminal 13 could be a positive electrode terminal, and the second electrode terminal 15 could be a negative electrode terminal. Furthermore, the opposite... Petition 870250093429, dated 10 / 13 / 2025, page 30 / 94 24 / 49 may also be possible.

[00156] An electrode assembly 20 is accommodated within the container 10. The electrode assembly 20 can be manufactured in jelly-roll form by preparing a first electrode 21, a second electrode 22 and a separator 28, which have a predetermined width and extend in the longitudinal direction, as shown in Figure 2, forming a laminate by sequentially stacking the first electrode 21, the separator 28, the second electrode 22 and the separator 28, as shown in Figure 3, and then winding them around a geometric winding axis, as shown in Figure 4.

[00157] The first electrode 21 can be a positive electrode and the second electrode 22 can be a negative electrode. Furthermore, the opposite is also possible.

[00158] The first electrode 21 and the second electrode 22 can be manufactured in the form of sheets. The electrode sheet is manufactured so that a layer of active material 24 is applied to the surface of a metal sheet 23. The electrode sheet has a coated area 25 where the layer of active material 24 is applied and an uncoated area 26 where the layer of active material 24 is not applied. The positive electrode sheet may have an uncoated area 26 on one side in the width direction. The negative electrode sheet may have an uncoated area 26 on the other side in the width direction.

[00159] The uncoated area 26 may be exposed or project from the laminate in the width direction. The width direction of the laminate may indicate a direction parallel to the geometric winding axis of the electrode assembly 20. The uncoated area 26 may function as an electrode tab 27 by itself.

[00160] Notches can be formed at a predetermined interval in the uncoated area 26 to form flag-shaped notched flaps 27. Petition 870250093429, dated 10 / 13 / 2025, page 31 / 94 25 / 49

[00161] The embodiment shows an example in which the notched tabs 27 are configured in an equilateral trapezoidal shape. However, these have various shapes, such as semicircles, semiovals, triangles, rectangles and parallelograms.

[00162] Furthermore, the embodiment shows an example in which the notched tabs 27 arranged in the longitudinal direction have the same width. However, the widths of the notched tabs may be gradually or stepwise increased from the core to the outer side.

[00163] Furthermore, the embodiment shows an example in which the heights of the notched flanges 27 gradually increase from the core to the outer side. However, the heights of the notched flanges can be implemented to be constant or to be gradually reduced.

[00164] Furthermore, the embodiment shows an example in which the notched tabs 27 are excluded from a predetermined section adjacent to the core of the uncoated area 26 and from a predetermined section adjacent to the outer side. However, it is obvious that the notched tabs may not be excluded from the predetermined section adjacent to the core of the uncoated area, and that the notched tabs may not be excluded from the predetermined section adjacent to the outer side of the uncoated area.

[00165] In the jelly-roll type electrode assembly 20, the notched tab 27 can be radially bent and flattened, as shown in Figure 4. The notched tab 27 can be radially bent inwards or outwards. The embodiment shows an example in which the notched tab 27 is radially bent inwards.

[00166] The notched tab 27 can be folded one by one during the process of forming the jelly-roll type electrode assembly 20, rolling the laminate. On the other hand, the notched tab 27 can be Petition 870250093429, dated 10 / 13 / 2025, page 32 / 94 26 / 49 folded in one go after the jelly-roll type electrode assembly is formed by rolling up the laminate.

[00167] The notched tabs 27 of the first electrode 21 and the notched tabs 27 of the second electrode 22, which are radially bent and stacked as described above, can provide a plane substantially perpendicular to the axial direction at both axial ends of the electrode assembly 20.

[00168] As shown in Figures 5 and 6, the first collector plate 31 and the second collector plate 32 can be attached to the substantially flat surface provided by folding the notched tabs 27 exposed through both axial ends of the electrode assembly 20, respectively.

[00169] The embodiment shows an example in which the first collector plate 31 is a positive electrode collector plate and the second collector plate 32 is a negative electrode collector plate. The first collector plate 31 can be made of aluminum and the second collector plate 32 can be made of copper.

[00170] Collector plates 31 and 32 can be manufactured by punching, trimming, drilling and bending a metal sheet.

[00171] Referring to Figure 5, the first collector plate 31 may include a terminal connection portion 312 extending radially from the center, an edge portion 313 connected to an outer end of the terminal connection portion 312 and extending in a circumferential direction, and an electrode connection portion 314 extending from the edge portion 313 toward the core. The electrode connection portion 314 may be spaced radially from the terminal connection portion 312. The center of the terminal connection portion 312 covers at least a portion of the core void of the electrode assembly 20. The central area of ​​the terminal connection portion Petition 870250093429, dated 10 / 13 / 2025, page 33 / 94 27 / 49 312 can be coupled to the first electrode terminal 13.

[00172] The electrode connection portion 314 can be connected to the notched tab 27 of the first electrode 21 of the electrode assembly 20 by laser welding or similar means before the electrode assembly 20 is stored inside the container 10. The laser welding line can extend radially.

[00173] Referring to Figure 6, the second collector plate 32 may have a hole 322 that corresponds to the core void (central winding hole) of the electrode assembly 20. The second collector plate 32 may include an inner ring portion 321 configured to encircle the core void, an electrode tab connection portion 323 extending radially from the inner ring portion 321, and a container connection portion 324 disposed further out than the electrode tab connection portion 323 and connected to the inner ring portion 321. The container connection portion 324 may be configured as a rim that encircles the rim of the second collector plate 32.

[00174] The electrode tab connection portion 323 can be connected to the notched tab 27 of the second electrode 22 of the electrode assembly 20 by laser welding or similar means before inserting the electrode assembly 20 into the container 10. The laser welding line can extend radially.

[00175] The first collector plate 31 and the second collector plate 32 can be connected to the electrode assembly 20 before the electrode assembly 20 is inserted into the container 10, as shown in the embodiment.

[00176] Furthermore, it is also possible to store the electrode assembly 20, to which only the first collector plate 31 is connected, inside the container 10 and then insert the second collector plate 32 into the container 10, thereby connecting it to the electrode assembly. Petition 870250093429, dated 10 / 13 / 2025, page 34 / 94 28 / 49 all 20.

[00177] As shown in Figures 7 and 8, the electrode assembly 20 can be stored inside the container 10 in the state where the first collector plate 31 is aligned to face the lower member 12 of the container 10. In this case, an insulator 19 can be interposed between the first collector plate 31 and the lower member 12 of the container 10, so that the first collector plate 31 and the lower member 12 are electrically isolated from each other. In the state where the electrode assembly 20 is inserted, the edge of the second collector plate 32 comes into contact with the container 10.

[00178] Furthermore, the terminal connection portion 312 of the first collector plate 31 can be connected to the first electrode terminal 13 fixed to the container 10 by resistance welding, ultrasonic welding, laser welding or similar methods. A welding device A for welding the first collector plate 31 and the first electrode terminal 13 can approach the center of the terminal connection portion 312 of the first collector plate 31 through the core void of the electrode assembly 20 at the open end of the container 10, thereby performing welding. Alternatively, a laser beam can be irradiated onto the inner surface of the center of the terminal connection portion 312 of the first collector plate 31 through the core void of the electrode assembly 20, thereby welding the terminal connection portion 312 and the first electrode terminal 13.Furthermore, the first collector plate 31 and the first electrode terminal 13 can also be connected by brazing or welding. That is, any method can be applied, provided it is capable of electrically connecting and securing the first collector plate 31 and the first electrode terminal 13 to each other.

[00179] In the state where the electrode assembly 20 is housed inside the container 10, the electrode tab 27 of the second electrode Petition 870250093429, dated 10 / 13 / 2025, page 35 / 94 29 / 49 and the second collector plate 32 can be arranged so as to face the open end of the side wall member 11.

[00180] After the first collector plate 31 and the first electrode terminal 13 are joined, an electrolyte can be injected into the container 10.

[00181] After the electrolyte is injected, the open end of the side wall member 11 can be covered and closed by a cap 16, as shown in Figure 9.

[00182] The edge of the lid 16 can rest against the container 10 and the edge of the second collecting plate 32, as shown in Figure 10.

[00183] Referring to Figure 11 and Figure 12, the side wall member 11 of the container 10 may have an expansion portion of internal diameter 113 at the open end. The expansion portion of internal diameter 113 may have a sloped surface provided on the inner surface of the side wall member 11, such that the internal diameter of the side wall member 11 increases as it approaches the outside in the axial direction. That is, the expansion portion of internal diameter 113 may include a sloped surface provided on the inner surface of the side wall member 11 that extends radially outward as it approaches the outside in the axial direction.

[00184] Consequently, the inner surface of the side wall member 11 may include a first inner surface 111 provided axially further inward than the inner diameter expansion portion 113, and a second inner surface 115 provided axially further outward than the inner diameter expansion portion 113.

[00185] The outer diameter of the side wall member 11 may be uniform in the axial direction, while the second inner surface 115 may have an inner diameter larger than that of the first sub Petition 870250093429, dated 10 / 13 / 2025, page 36 / 94 30 / 49 inner surface 111. Consequently, the radial thickness of the side wall member 11 in the section of the second inner surface 115 may be less than the radial thickness in the section of the first inner surface 111.

[00186] The container connection portion 324 provided on the edge of the second collector plate 32 and in electrical contact with the container 10 may include a first portion that, at least in part, faces or contacts the inner surface 111, 113 or 115 of the side wall member 11. An external contact surface 325 may be provided on the first portion so as to face or contact the inner surface 111, 113 or 115 of the side wall member 11 in the radial direction.

[00187] The container connection portion 324 may include a second portion that contacts the lid 16. A lid contact surface 326 may be provided on the second portion so as to face and contact the axially inner surface of the lid 16.

[00188] The second collector plate 32 may include a bent portion 327. The bent portion 327 is configured so that the second collector plate 32, which extends outward in the radial direction, bends outward in the axial direction. The container connection portion 324 of the second collector plate 32 may be connected to the electrode tab connection portion 323 through the bent portion 327 and the inner ring portion 321 described above.

[00189] The container connection portion 324 can be connected to the axially external side of the bent portion 327 and can be configured to extend from the bent portion 327 outwards in the axial direction. Consequently, the area and axial length of the external contact surface 325 of the second collector plate 32 can be further secured. Petition 870250093429, dated 10 / 13 / 2025, page 37 / 94 31 / 49

[00190] The material of the second collector plate 32 may be softer than the material of the side wall member 11.

[00191] The thermal conductivity of the second collector plate 32 may be greater than the thermal conductivity of the side wall member 11.

[00192] For example, the material of the second collector plate 32 may include copper. The material of the side wall member 11 may include iron. However, the materials of the second collector plate 32 and the side wall member 11 of the present invention are not limited to this.

[00193] The outer diameter of the outer contact surface 325 of the container connection portion 324 can be adjusted to be larger than the inner diameter of the first inner surface 111.0 The outer diameter of the outer contact surface 325 can match or be smaller than the inner diameter of the second inner surface 115.

[00194] Then, the folded portion 327 is elastically deformed by inserting the second collector plate 32, and the outer contact surface 325 is forcibly pressed against the first inner surface 111, so that the outer contact surface 325 and the first inner surface 111 can come into close contact in the radial direction. Consequently, as a result, the outer diameter of a first section a of the outer contact surface 325 pressed against the first inner surface 111 in the axial direction corresponds to the inner diameter of the first inner surface 111.

[00195] As described above, the multi-stage internal surface structure of the side wall member 11 and the structure of the container connection portion 324 of the collector plate 32 can certainly cause at least an axial portion of the external contact surface 325 to come into close contact with the internal surface. Petition 870250093429, dated 10 / 13 / 2025, page 38 / 94 32 / 49 of side wall member 11.

[00196] The folded portion 327 can provide a curved surface whose outer diameter gradually decreases from the axial inner end to the axial inner side, compared to the container connection portion 324. Furthermore, the minimum outer diameter d of the curved surface measured at the lower end of the second collector plate 32 can be smaller than the inner diameter of the first inner surface 111. This shape can guide the container connection portion 324 to be forcibly pressed against the first inner surface 111 during the process of inserting the second collector plate 32 into the inner space of the side wall member 11. Therefore, the process of forcibly pressing the second collector plate 32 can be performed more easily.

[00197] As a result, according to the present invention, if only the dimensional relationship is maintained such that the minimum external diameter d of the folded portion 327 is smaller than the internal diameter of the first internal surface 111 of the side wall member 11 and such that the external diameter of the external contact surface 325 of the second collector plate 32 is larger than the internal diameter of the first internal surface 111, despite the dimensional tolerances of the components, it is possible to obtain the effect in which the first section a of the external contact surface 325 comes into close contact with the first internal surface 111 of the side wall member 11 in the forced fitting portion P. Furthermore, such dimensional management can be easily achieved.

[00198] Consequently, in the present invention, even if a portion of the laser beam L is irradiated into the interior of the container, as shown in Figure 13 during the welding process described below, the second inner surface 115, the outer contact surface 325 and the inner diameter expansion portion 113 po Petition 870250093429, dated 10 / 13 / 2025, page 39 / 94 33 / 49 dem block it, so that the laser beam L may not reach the components housed inside the container 10.

[00199] The cap 16 may have a cap body 160, a thickness-reducing portion 161, and a connecting portion 17 in sequence from the radial center to the outer side. That is, the thickness-reducing portion 161 may be provided adjacent to the radially outer side of the cap body 160, and the connecting portion 17 may be provided on the radially outer side of the thickness-reducing portion 161.

[00200] Consequently, a first thickness t1 of the connecting portion 17 measured in the axial direction can be configured to be smaller than a second thickness t2 of the cover body 160 measured in the axial direction.

[00201] An external connecting surface 171 may be provided on the connecting portion 17 of the cover 16 so as to face the second internal surface 115 of the side wall member 11 to be close to or contact it in the radial direction. In addition, a collector plate contact surface 173 may be provided on the axially internal surface of the connecting portion 17 of the cover 16 so as to face and contact the cover contact surface 326 of the container connection portion 324 of the second collector plate 32 in the axial direction.

[00202] The weld portion described below can be formed between the outer bonding surface 171 of the cover 16 and the second inner surface 115 of the side wall member 11. Accordingly, even if the cover 16 and the side wall member 11 are welded to a depth of the first thickness t1, the contact portion between the cover 16 and the side wall member 11 can be completely bonded and connected. Then, even if a bulging phenomenon occurs in the cover 16 due to an increase in the internal pressure of the container 10, no stress concentration occurs in the Petition 870250093429, dated 10 / 13 / 2025, page 40 / 94 34 / 49 connecting portion of container 10 and lid 16, and the thick lid body 160 can strongly resist bulging.

[00203] The thickness reduction portion 161 is a thickness change portion provided in the cap 16.

[00204] By appropriately selecting the position of the thickness-reducing portion 161 so that at least a portion of the thickness-reducing portion 161 contacts the second collector plate 32, the thickness-reducing portion 161 of the cover 16 can contact the second collector plate 32 during the process of inserting the cover 16, facilitating the alignment of the cover 16.

[00205] In this embodiment, the thickness-reducing portion 161 is implemented in the form of an inclined surface that extends axially outward as it approaches the radially outer side of the cover 16, so as to improve the alignment effect.

[00206] During the process of inserting the cover 16 into the inner side wall member 11, the thickness-reducing portion 161 in the form of an inclined surface can come into contact with the radially inner edge of the cover contact surface 326. Consequently, the axially outer end of the container connection portion 324 of the second collector plate 32 provided with the cover contact surface 326 can be radially pressed outwards by the thickness-reducing portion 161 so as to be disposed closer to or in closer contact with the second inner surface 115 of the side wall member 11.

[00207] That is, the thickness-reducing portion 161 in the form of an inclined surface can come into contact with the container connection portion 324 of the second collector plate 32 during the process of inserting the lid 16 through the open end of the side wall member 11, thereby guiding the alignment of the lid 16 in relation to the center of the second collector plate 32 and pressing Petition 870250093429, dated 10 / 13 / 2025, page 41 / 94 35 / 49 the axially outer end of the container connection portion 324 of the second collector plate 32 radially outward to bring the axially outer end of the container connection portion 324 of the second collector plate 32 into close contact with the second inner surface 115 of the side wall member 11.

[00208] According to cover 16 of the embodiment, the radial position of the thickness-reducing portion 161 can be arranged as close as possible to the weld portion, so that the area of ​​the cover body 160 that resists bulging can be maximally safe. Furthermore, such a selection of the position of the thickness-reducing portion 161 can also provide a guide function to align the cover 16 while it is in contact with the second collector plate 32.

[00209] In the state where the cover 16 is inserted through the open end of the side wall member 11, the outer bonding surface 171 of the cover 16 and the outer contact surface 325 of the second collector plate 32 can closely face or contact the second inner surface 115 of the side wall member 11 in the radial direction. That is, the outer bonding surface 171 of the cover 16 can face or contact the second inner surface 115 in the radial direction, and the outer contact surface 325 of the container connection portion 324 can face or contact the second inner surface 115 in a position axially more inward than the outer bonding surface 171 in the radial direction.

[00210] Furthermore, the contact surface of the cover 326, provided on the axially outer end of the container connection portion 324 of the second collector plate 32, may come into contact with the contact surface of the collector plate 173, provided on the inner surface of the connection portion 17 of the cover 16 in the axial direction. Petition 870250093429, dated 10 / 13 / 2025, page 42 / 94 36 / 49

[00211] According to this mounting structure, the insertion depth of the lid 16 can be precisely determined by the height H of the second collector plate 32, which can be influenced by the axial extension length of the container connection portion 324.

[00212] Meanwhile, there may be some errors in the outer diameter of the outer bonding surface 171 of the cover 16, in the inner diameter of the second inner surface 115 of the side wall member 11 and / or in the outer diameter of the outer contact surface 325 of the second collector plate 32 due to dimensional differences resulting from the component manufacturing process or similar. The occurrence of such errors may prevent the outer bonding surface 171 of the cover 16 and the outer contact surface 325 of the second collector plate 32 from coming into close contact with the second inner surface 115 of the side wall member 11.However, according to the battery cell structure of the present invention described above, the structure provided with the forced-fit portion P and the internal diameter expansion portion 113 shown in Figure 3 can significantly reduce the risk of the laser beam L irradiated for welding penetrating the container 10, thereby damaging the electrode assembly 20.

[00213] According to one aspect of the present invention, as shown in the drawing, the outer bonding surface 171 of the cover 16 and the axial end of the inner surface of the side wall member 11, which meet each other in the radial direction, can be exposed to the axially outer side.

[00214] The cover 16 can be welded to the container 10 by the laser beam L irradiated on the axial end of the contact portion between the outer bonding surface 171 of the cover 16 and the second inner surface 115 of the side wall member 11, on the axially outer side of the battery cell. Petition 870250093429, dated 10 / 13 / 2025, page 43 / 94 37 / 49

[00215] The second collector plate 32 above may be made of a material that has higher thermal conductivity than the side wall member 11. As described above, if the thermal conductivity of the side wall member 11 is relatively low, the risk of damage to the separator provided in the electrode assembly 20 due to heat conduction generated during welding can be reduced. The second collector plate 32 may be in contact with the side wall member 11. Therefore, the welding heat generated by the laser beam in the side wall member 11 may be conducted to the electrode assembly 20 through the second collector plate 32, and the conducted welding heat may be transmitted to the separator of the electrode assembly 20 facing the side wall member 11, thereby damaging the separator.However, as described above, if the thermal conductivity of the side wall member 11 is set to be lower than that of the second collector plate 32, the risk of damage to the separator due to heat conduction through the side wall member 11 can be reduced.

[00216] The process of connecting and electrically attaching the second collector plate 32 to the side wall member 11 of the container 10 and the process of sealing the container 10 by connecting the edge of the lid 16 to the side wall member 11 of the container 10 can be performed together by seam welding.

[00217] By seam welding, the edge of the lid 16 can be connected to the side wall member 11 of the container 10 to be sealed and, at the same time, the second collector plate 32 can be connected to the side wall member 11 of the container 10.

[00218] As shown in Figure 14, this seam welding can be performed by irradiating a laser beam L onto the contact portion of the outer bonding surface 171 of the cover 16 and the second inner surface 115 of the side wall member 11, extending into Petition 870250093429, dated 10 / 13 / 2025, page 44 / 94 38 / 49 circumferential direction, that is, irradiating the laser beam by scanning over the entire contact portion in the circumferential direction.

[00219] As the scanning radiation is performed, the laser radiation area B moves along the contact portion (see C in Figure 14) and, consequently, the molten pool is continuously generated, propagated and solidified in the circumferential direction in the contact portion.

[00220] If the consistency of the generation, propagation and solidification of the molten pool is ensured during a seam welding process, the quality of the weld portion between the edge of the cover 16 and the end of the side wall member 11 of the container 10 can be improved, thereby sufficiently ensuring the required sealing performance.

[00221] According to the embodiment, preliminary welding can be performed before seam welding, thereby increasing the match between container 10 and lid 16 and increasing the resistance to deformation of container 10 and lid 16, which can occur due to the welding heat during the main welding. Furthermore, seam welding can be performed as the main welding performed after the preliminary welding described above.

[00222] The embodiment shows an example in which the main weld is performed after the preliminary weld. However, it is obvious that seam welding can be performed without preliminary welding.

[00223] Referring to Figures 14 and 15, preliminary welding can be performed in multiple positions spaced apart from each other in the circumferential direction of the contact portion of the container 10 and the lid 16. This preliminary welding can be performed, for example, by irradiating a laser beam with lower output or lower density of Petition 870250093429, dated 10 / 13 / 2025, page 45 / 94 39 / 49 energy than the main welding to lightly fix container 10 and lid 16.

[00224] For reference, energy density is proportional to the value obtained by dividing the laser output by the area of ​​the radiation region. That is, the greater the laser output, the greater the energy density, and the wider the radiation area, the lower the energy density.

[00225] The preliminary welding positions and the degree of welding can be determined to minimize the inhibition of molten pool propagation that can occur at the boundary of the preliminary welding area when performing the main welding, while increasing the match and resistance to deformation. Consequently, by scanning the laser in the circumferential direction during the main welding process, the consistency and stability of the molten pool can be ensured.

[00226] The embodiment shows an example in which the W3 preliminary weld portions are formed to have a minimum weld area by preliminary welding in a minimum number of positions required, i.e., in four positions, so that no weld discontinuity occurs at the weld interface.

[00227] Seam welding can be performed as the main welding continuously on the contact portion along the circumferential direction, so that the first weld portions W1, in which the container 10, the second collector plate 32 and the cover 16 are welded together, are intermittently formed, and so that the second weld portions W2, in which at least the container 10 and the cover 16 are welded together, are formed on the remaining seam welding sections.

[00228] This seam welding can be performed with a laser output, a radiation area, an energy density and Petition 870250093429, dated 10 / 13 / 2025, page 46 / 94 40 / 49 a scanning speed capable of basically forming the second weld portion W2 to seal and fix the container 10 and the lid 16, while maximally suppressing the generation of welding heat. Meanwhile, seam welding can be performed by intermittently varying at least one of the laser output, radiation area, energy density, and scanning speed during the laser scanning process. By intermittently varying the laser scanning conditions, as described above, the first weld portion W1, which is a triple weld portion in which the container 10, the lid 16, and the second collector plate 32 are welded together, can be formed.

[00229] As the number of first W1 solder portions increases and the formation section of the first W1 solder portions becomes longer, the internal resistance can be reduced.

[00230] However, to triple weld the container 10, the lid 16 and the second collector plate 32 together, the weld depth must be greater than the second weld portion W2 or the weld cross-sectional area must be wider when viewed in the circumferential direction. However, this can cause excessive welding heat. Therefore, it is preferable that the first weld portion W1 be formed to the minimum extent possible, to the point of reducing the internal resistance to the required degree. Referring to Figure 16, the embodiment shows an example in which four first weld portions W1 are arranged at equal intervals, and in which each first weld portion W1 is formed in a section smaller than approximately 15 degrees in the circumferential direction.

[00231] In the section that forms the first portion of weld W1, it is necessary to satisfy at least one of the following conditions: an increase in laser output or energy density, a decrease in radiation area, and a decrease in laser scanning speed. Petition 870250093429, dated 10 / 13 / 2025, page 47 / 94 41 / 49 compared to the section that forms the second portion of weld W2.

[00232] Meanwhile, as the process of forming the first weld portion W1 is intermittently performed during the seam welding process for forming the second weld portion W2, it is desirable to continuously maintain the stability and consistency of the molten pool maintained in the second weld portion W2.

[00233] In consideration of this, the embodiment proposes a method to increase the energy density by increasing the laser output, while maintaining the radiation area and scanning speed, when forming the first weld portion W1 in the middle of the formation of the second weld portion W2 during the laser scanning welding process. According to this embodiment, when forming the second weld portion W2 in the middle of the formation of the first weld portion W1, the radiation area and scanning speed can be maintained and the laser output can be reduced again.

[00234] Furthermore, in the output increase section, where the second solder portion W2 alternates to the first solder portion W1, and in the output decrease section, where the first solder portion W1 alternates to the second solder portion W2, it is desirable to control the laser output to increase or decrease continuously, rather than abruptly increasing or decreasing in a stepped manner.

[00235] In addition, the output increase rate in the output increase section can be set to be greater than the output decrease rate in the output decrease section.

[00236] When the laser irradiated with a first output (lower output) in the second weld section W2 is increased to a second output (upper output), which is larger than the first output, to form the first weld section W1, the output is increased very rapidly at a first increase / decrease rate, so that the heat generation of welding increases Petition 870250093429, dated 10 / 13 / 2025, page 48 / 94 42 / 49 quickly. Then, the generated welding heat can be intensively used to melt the portion to be welded before being transferred to another portion, so that the triple welding of container 10, lid 16 and second collector plate 32 can be reliably performed, and the side effect of the welding heat transfer being to the electrode assembly can be reduced.

[00237] When the laser irradiated with the second output in the section for forming the first portion of weld W1 is reduced to the first output for forming the first portion of weld W1, the output is reduced slowly at a second rate of increase / decrease, which is lower than the first rate of increase / decrease, so that the molten pool can be stably propagated.

[00238] Referring to Figures 16 to 19, it is preferable that the formation section of the first weld portion W1 be arranged so as not to overlap the preliminary weld portion, that is, the formation position of the third weld portion W3, in the circumferential direction. That is, the formation section of the first weld portion W1 and the formation section of the third weld portion W3 cannot overlap each other. In other words, the formation section of the third weld portion W3 can be included within the formation section of the second weld portion W2.

[00239] However, the third solder portion W3 can be placed in the formation section of the first solder portion W1, provided that the degree of interference with the propagation of the molten pool, which may be caused by the third solder portion W3, is not large.

[00240] Referring to Figure 20, the side wall member 11 of the container 10 can extend longer than the side wall member 11 in the previous embodiment. Consequently, as shown in Figure 20, in the state in which the second collector plate 32 and the lid 16 are inserted into the container 20, a projection 117 Petition 870250093429, dated 10 / 13 / 2025, page 49 / 94 43 / 49 axially further out than cap 16 may be provided at the end of side wall member 11.0 side wall member 11 may have a thickness less than cap 16.

[00241] In this case, the protrusion 117 can retard the fusion time of the side wall member 11, which is thinner than the cap 16, thereby reducing the difference in fusion time between the side wall member 11 and the cap 16. In the process of forming the weld portion, the protrusion 117 can be fused to flow into the weld portion of the second inner surface 115 of the side wall member 11 and the outer bonding surface 171 of the cap 16 (see Figure 13). Consequently, despite the deviation in the welding process, the weld portion can be formed over the entire outer bonding surface 171 of the cap 16 in the axial direction.

[00242] In the forming section of the first weld portion W1, the protrusion 117 can be completely fused to flow to the contact portion of the second inner surface 115 of the side wall member 11, the outer bonding surface 171 of the cover 16 and the container connection portion 324 of the second collector plate 32, as shown in Figure 19.

[00243] In the forming section of the second weld portion W2, the protrusion 117 can be completely fused to flow to the contact portion of the second inner surface 115 of the side wall member 11 and the outer bonding surface 171 of the cover 16, as shown in Figure 17. Consequently, the height of the battery cell can be defined by the outer surface of the cover 16. That is, according to a modified example, since the protrusion 117 and the weld portion do not determine the height of the battery cell, the height dimension of the battery cell can be consistently managed as a result.

[00244] Hereafter, a method of manufacturing the baPetition 870250093429, dated 10 / 13 / 2025, page 50 / 94 44 / 49 would have been described above will be described with reference to Figure 21.

[00245] According to the battery cell manufacturing method, first, a container 10 having a first electrode terminal 13 attached to a lower member 12 is prepared, and an electrode assembly 20 having a first collector plate 31 and a second collector plate 32 connected at both axial ends, respectively.

[00246] Next, the electrode assembly 20 is inserted and received inside the container 10 with the first collector plate 31 facing the lower member 12. Then, the second collector plate 32 is positioned at the open end of the container 10. In the process of storing the electrode assembly 20 inside the container 10, the first section a of the outer contact surface 325 of a container connection portion 324 provided on the radially outer edge of the second collector plate 32 comes into close contact with the first inner surface 111 of the side wall member 11.

[00247] Next, the first collector plate 31 and the first electrode terminal 13 are connected.

[00248] In addition, an electrolyte is injected into container 10.

[00249] After the electrolyte injection is completed, the open end of the side wall member 11 is covered with a cap 16, and the outer bonding surface 171 and the collector plate contact surface 173, provided on the edge of the cap 16, are placed in contact or face the second inner surface 115 of the side wall member 11 and the cap contact surface 326 of the second collector plate 32, respectively.

[00250] In this case, the thickness reduction portion 161 configured in the form of an inclined surface on the axially inner surface of the cover 16 is placed in contact with the container connection portion 324 of the second collector plate 32, by means of this there Petition 870250093429, dated 10 / 13 / 2025, page 51 / 94 45 / 49 nhando a tampa 16, e a superfície de contato externa 325 da porção de ligação de container 324 pode ser prensa em sentido a segundo superfície interna 115 do membro de parede lateral 11.

[00251] Next, a laser beam is irradiated onto the contact portion of the second inner surface 115 of the side wall member 11 and the outer bonding surface 171 of the cover 16 in the axial direction of the axially external side, thereby performing the welding.

[00252] In this case, the projection 117 of the side wall member 11, which projects further out than the cover 16 in the axial direction, can be fused to flow into the weld portion between the inner surface of the side wall member 11 and the outer bonding surface 171 of the cover 16.

[00253] When performing welding, the preliminary welding process can be performed first, and then the main welding can be performed.

[00254] In the preliminary welding process, a laser beam is irradiated onto the contact portion of the inner surface of the side wall member 11 and the outer bonding surface 171 of the cover 16 in the axial direction of the axially outer side at multiple positions spaced apart from each other along the circumferential direction, thereby forming a plurality of preliminary weld portions W3 by welding the inner surface of the side wall member 11 and the outer bonding surface 171 of the cover 16. The preliminary welding is performed at a low output so that the generation of a discontinuous surface can be suppressed.

[00255] Preliminary welding can be omitted.

[00256] Next, in the main welding process, a laser beam is continuously irradiated along the circumferential direction onto the contact portion of the inner surface of the wall member. Petition 870250093429, dated 10 / 13 / 2025, page 52 / 94 46 / 49 side 11 and the outer bonding surface 171 of the cover 16 in the axial direction of the axially external side, so as to form a second weld portion W2 in which at least the inner surface of the side wall member 11 and the outer bonding surface 171 of the cover 16 are welded together.

[00257] In this case, in the process of forming the second weld portion W2, at least one of the laser output, radiation area, energy density in the radiation area, and scanning speed can be adjusted to intermittently increase the welding depth and / or the weld cross-sectional area, so as to weld the inner surface of the side wall member 11, the outer connection surface 171 of the cover 16, and the container connection portion 324 of the second collector plate 32 together, thereby forming the first weld portion W1 as a triple weld portion.

[00258] The battery cell 72 manufactured using the welding structure and welding process described above can be accommodated in a housing 71 of a battery pack 70, as shown in Figure 22. The battery pack 70 can be configured using a battery module, as an intermediate mounting method, or it can be directly configured without the battery module, as shown.

[00259] Because the battery cell 72 described above has a large volume, there is no specific difficulty in implementing the battery pack 70, even without using an intermediate battery module structure. Furthermore, the battery cell 72 has low internal resistance and higher energy density. Consequently, the energy density of the battery pack 70 equipped with the battery cell 72 can be implemented at a higher level.

[00260] The 70 battery pack with energy density au Petition 870250093429, dated 10 / 13 / 2025, page 53 / 94 47 / 49 can store the same energy while reducing its volume and weight. Therefore, if the battery pack 70 to which the battery cell 72 is applied is mounted in a vehicle, such as vehicle 80, which uses electricity as a power source, as shown in Figure 23, the vehicle's energy mileage can be further increased.

[00261] It should be understood that the embodiments described above are exemplary in all respects, rather than limiting the present invention, and the scope of the present invention will be indicated by the claims described below, rather than the detailed description described above. Furthermore, the scope of the present invention should be interpreted to encompass all alterations and modifications derived from the equivalent concept, as well as the meaning and scope of the claims to be described subsequently.

[00262] As described above, although the present invention has been described with reference to limited embodiments and designs, the present invention is not limited to this, and it is obvious to those skilled in the art that various modifications and variations are possible within the technical idea of ​​the present invention. Furthermore, even though the effects according to the configuration of the present invention have not been explicitly described when explaining the embodiments of the present invention, it is apparent that the effects foreseeable by the configuration should also be accepted. [DESCRIPTION OF SYMBOLS / REFERENCE NUMBERS] 10: Container 11: Side wall member 111: First inner surface 113: Internal diameter expansion portion 115: Second inner surface 117: Protrusion Petition 870250093429, dated 10 / 13 / 2025, p. 54 / 94 48 / 49 12: Lower limb 13: First electrode terminal (positive electrode terminal) 14: Joint 15: Second electrode terminal 16: Lid 160: Lid body 161: Thickness reduction portion 17: Binding portion 171: External bonding surface 173: Collector plate contact surface 19: Insulator 20: Electrode assembly 21: First electrode 22: Second electrode 23: Metal sheet 24: Active material layer 25: Covered area 26: Unpaved area 27: Electrode tab (notched tab) 28: Separator 31: First collector plate (positive electrode collector plate) 312: Terminal connection portion 313: Ring portion 314: Electrode connection portion 32: Second collector plate (negative electrode collector plate) 321: Inner ring portion 322: Hole 323: Electrode tab connection portion 324: Container connection portion 325: External contact surface Petition 870250093429, dated 10 / 13 / 2025, page 55 / 94 49 / 49 326: Cover contact surface 327: Double Portion 70: Battery pack 71: Accommodation 72: Battery cell 80: Vehicle A: Welding device B: Laser radiation area C: Laser scanning path W1: First portion of solder W2: Second solder joint W3: Third solder section Petition 870250093429, dated 10 / 13 / 2025, page 56 / 94

Claims

1 / 7 CLAIMS 1. Battery cell, characterized in that it comprises: a container comprising a lower member, a side wall member connected to the lower member and extending in an axial direction, and a cover configured to cover an open end provided at an axial end of the side wall member;and an electrode array housed within the vessel, wherein a vessel connection portion is provided on an edge of a collector plate electrically connected to an electrode of the electrode array so as to make electrical contact with the vessel, wherein a plurality of first weld portions, in which an edge of the open end of the side wall member, an edge of the cover and the vessel connection portion are welded together, are formed to be spaced from each other in a circumferential direction, and in which a second weld portion, in which at least one edge of the open end of the side wall member and an edge of the cover are welded, is formed continuously along the circumferential direction between two first weld portions that are adjacent in the circumferential direction so as to be connected to the two first weld portions.

2. Battery cell, according to claim 1, characterized in that third weld portions, in which an edge of the open end of the side wall member and an edge of the cover are welded, are formed to be spaced from each other in the circumferential direction, and in which the weld depth of the second weld portion is greater than the weld depth of the third weld portion or a cross-sectional area of ​​the second weld portion is greater than the cross-sectional area of ​​the third weld portion when viewed in the circumferential direction.

3. Battery cell, according to claim 2, characterized in that a section where the third weld portion is formed does not overlap a section where the first weld portion is formed in the circumferential direction.

4. Battery cell, according to claim 2, characterized in that a section where the third solder portion is formed overlaps a section where the second solder portion is formed in the circumferential direction.

5. Battery cell, according to claim 1, characterized in that the welding depth of the first welding portion is greater than the welding depth of the second welding portion, or in that the cross-sectional area of ​​the first welding portion is greater than the cross-sectional area of ​​the second welding portion when viewed in the circumferential direction.

6. Battery cell, according to claim 1, characterized in that the container connection portion comprises: an external contact surface in which a first section, which is at least a portion of an axial section, faces and contacts an internal surface of the side wall member in a radial direction; and a cover contact surface configured to face and contact an internal surface of the cover in the axial direction, and in which the cover comprises an external contact surface configured to face or contact the internal surface of the side wall member in the radial direction.

7. Battery cell, according to claim 6, characterized in that the cover comprises a collector plate contact surface defined by an axially inner cover surface configured to face and contact a cover contact surface of the collector plate container connection portion in the axial direction, and wherein the outer cover connection surface is disposed axially further outward and radially further outward than the collector plate contact surface.

8. Battery cell, according to claim 7, characterized in that the cover comprises a radially inclined surface disposed further inward than the collector plate contact surface on the axially inner surface of the cover and extending axially inward as it approaches the radially inner side, and wherein the inclined surface contacts at least one corner portion that forms a boundary between an axially outer end and a radially inner end of the collector plate container connection portion.

9. Battery cell, according to claim 6, characterized in that an outer diameter of the first section of the outer contact surface is larger than an inner diameter of the inner surface of the side wall member in contact with it, such that the first section of the outer contact surface is forcibly pressed against the side wall member.

10. Battery cell, according to claim 6, characterized in that the lateral wall member comprises, at one axial end: an internal diameter expansion portion having an inclined shape, so that an internal diameter of the lateral wall member is increased; a first internal surface provided axially inward, based on the internal diameter expansion portion; and a second internal surface provided axially outward, based on the internal diameter expansion portion, and having an internal diameter larger than that of the first internal surface, wherein the external contact surface of the container connection portion faces or contacts the second internal surface, and wherein the external connection surface of the cover faces or contacts the second internal surface.

11. Battery cell, according to claim 10, characterized in that an outer diameter of the first section of the outer contact surface is larger than an inner diameter of the first inner surface.

12. Battery cell, according to claim 10, characterized in that an outer diameter of the outer contact surface is equal to or smaller than an inner diameter of the second inner surface.

13. Battery cell, according to claim 6, characterized in that a protrusion is provided on an axial end of the side wall member so as to project further outward than the cover in the axial direction, and in that the protrusion is fused to flow into a welded portion of the inner surface of the side wall member and the outer bonding surface of the cover. Petition 870250093429, dated 10 / 13 / 2025, p. 60 / 94 5 / 7 14. Battery cell, according to claim 13, characterized in that a height of the battery cell is defined by a surface of the cap.

15. Method for manufacturing a battery cell, comprising: a container comprising a lower member, a side-wall member connected to the lower member and extending in an axial direction, and a lid configured to cover an open end provided at an axial end of the side-wall member; an electrode assembly accommodated within the container; and a collector plate coupled to one side of the electrode assembly, the method characterized in that it comprises: a first step of placing an external contact surface of a container connection portion provided on a radially external edge of the collector plate in contact with an internal surface on the open end of the side-wall member;A second step involves covering the open end of the side wall member with the cap, causing an external bonding surface provided on one edge of the cap to face the internal surface of the side wall member in a radial direction, and placing an internal surface of the cap in contact with a contact surface of the collector plate cap in the axial direction;and a third step of irradiating a laser beam onto a contact portion of the inner surface of the side wall member and the outer bonding surface of the cover in the axial direction from an axially external side, while continuously irradiating the laser beam along a circumferential direction, and performing the welding so that a first weld portion in which the inner surface of the side wall member, the outer bonding surface of the cover and the container connection portion of the collector plate are welded together alternates with a second weld portion in which at least the inner surface of the side wall member and the outer bonding surface of the cover are welded together.

16. Method for manufacturing a battery cell, according to claim 15, characterized in that it comprises alternately forming the first solder portion and the second solder portion in such a way that a circumferential length of the second solder portion is formed that is longer than a circumferential length of the first solder portion.

17. Method for manufacturing a battery cell, according to claim 15, characterized in that it further comprises a preliminary welding step, performed between the second and third steps, forming a plurality of third weld portions, in which an edge of the open end of the side wall member and an edge of the cap are welded, spaced from each other in the circumferential direction.

18. Method for manufacturing a battery cell, according to claim 17, characterized in that the third step comprises a step of melting a protrusion of the side wall member, which projects further outward in the axial direction than the cover, to flow into a weld portion of the inner surface of the side wall member and the outer bonding surface of the cover.

19. Method for manufacturing a battery cell, according to claim 15, characterized in that the intensity of a laser beam irradiated onto a section for welding the first weld portion or the energy density of a laser radiation area thereof is stronger or greater than the intensity of a laser beam irradiated onto a section for welding the second weld portion or the energy density of a laser radiation area thereof.

20. Method for manufacturing a battery cell, according to claim 19, characterized in that the speed of movement of a radiation area of ​​the laser beam irradiated onto the section for welding the first weld portion and the speed of movement of a radiation area of ​​the laser beam irradiated onto the section for welding the second weld portion are constant. Petition 870250093429, dated 10 / 13 / 2025, pp. 63 / 94

Images