Battery cell, and battery pack and vehicle comprising same

Abstract

The battery cell according to the present invention comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis; a battery housing having an open end to allow the electrode assembly to be inserted therein; and a lid assembly comprising a housing lid configured to seal the open end and a first current collector plate detachably assembled to the housing lid, wherein the first current collector plate is seated in the open end so as to be electrically connected to the first electrode.

Description

Battery cells, battery packs including the same, and automobiles

[0001] The present invention relates to a battery cell, and more specifically, to a battery cell having an improved assembly structure between a battery housing, a current collector plate, and a housing lead, and to a battery pack and an automobile including the same.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2024-0193088 filed on December 20, 2024, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Secondary batteries, which offer high applicability across product categories and possess electrical characteristics such as high energy density, are widely applied not only to portable devices but also to electric vehicles (EVs) and hybrid electric vehicles (HEVs) powered by electric driving sources.

[0004] These secondary batteries are attracting attention as a new energy source for improving eco-friendliness and energy efficiency, as they not only have the primary advantage of being able to drastically reduce the use of fossil fuels but also the advantage of not generating any by-products from the use of energy.

[0005] Cylindrical, prismatic, and pouch-type battery cells are widely known as types of secondary batteries. In the case of a cylindrical battery cell, an insulating separator is placed between the positive and negative electrodes and wound to form a jellyroll-shaped electrode assembly, which is then inserted into a housing along with an electrolyte to constitute the battery. Additionally, strip-shaped electrode tabs can be connected to the uninsulated portions of the positive and negative electrodes, and these electrode tabs electrically connect the electrode assembly with the externally exposed electrode terminals. For reference, the positive electrode terminal is the cap of the seal that seals the opening of the housing, and the negative electrode terminal is the housing.

[0006] However, conventional cylindrical batteries having such a structure had the problem that current was concentrated in the strip-shaped electrode tabs connected to the positive electrode unoccupied part and / or the negative electrode unoccupied part, resulting in high resistance, excessive heat generation, and poor current collection efficiency.

[0007] For small cylindrical batteries with 1865 or 2170 form factors, resistance and heat generation are not major issues. However, if the form factor is increased to apply cylindrical batteries to electric vehicles, a problem may arise where the cylindrical battery catches fire as a large amount of heat is generated around the electrode tabs during fast charging.

[0008] To solve these problems, a cylindrical battery (so-called tab-less cylindrical battery) is proposed that has a structure with improved current collection efficiency by designing a positive electrode-free section and a negative electrode-free section to be located at the top and bottom, respectively, of a jellyroll-type electrode assembly, and welding a current collection plate to these non-parts.

[0009] Meanwhile, conventional cylindrical battery cells, as disclosed in Korean Published Patent No. 10-2024-0069584, include a beading section and a crimping section for assembly between a current collector, a battery housing, and a housing cover. The beading section has a shape that is pressed inward in the area between an opening formed on one side of the battery housing and a receiving section that accommodates an electrode assembly. The crimping section has a shape that extends and is bent from the beading section to wrap around the outer perimeter of the housing cover. A cylindrical battery having the beading section and the crimping section has the advantage of facilitating the fixation of the negative electrode current collector and providing excellent airtightness between the battery housing and the housing cover. However, the process for forming the beading section and the crimping section is not a simple process that requires precision. Consequently, product defects frequently occur during the beading or crimping fixation process, which can lead to a decrease in production yield. Furthermore, it has been pointed out that a cylindrical battery having the beading section and the crimping section is disadvantageous in terms of energy density. Accordingly, it is necessary to eliminate the beading part and the clamping part in the battery housing and to improve the sealing structure to be simpler.

[0010] The present invention was devised in consideration of the aforementioned problems and aims to provide a battery cell that, unlike conventional battery cells, eliminates the beading and crimping portions, seals the battery housing with a housing lid, and electrically connects the current collector plate.

[0011] One objective of the present invention is to provide a battery cell that allows for easy alignment of the housing lead and the current collector plate with respect to the battery housing during the manufacturing process, thereby improving the welding quality between the battery housing, the housing lead, the current collector plate, and the electrode assembly.

[0012] The technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below.

[0013] According to the present invention, an electrode assembly comprising a first electrode and a second electrode and a separator interposed between them, wound around a winding axis; a battery housing having an open end into which the electrode assembly is inserted; and a lead assembly comprising a housing lead configured to seal the open end and a first current collector plate detachably assembled to the housing lead, wherein the first current collector plate is seated at the open end so as to be electrically connected to the first electrode.

[0014] The above lead assembly may be configured such that the first collector plate surrounds the outer perimeter of the housing lead, and the housing lead is press-fitted into the inner area of ​​the first collector plate.

[0015] The above lead assembly may be configured so that the housing lead and the first collector plate come into face-to-face contact with each other.

[0016] The first current collector plate may be configured to have a welding tip portion that contacts the inner surface of the open end and the outer surface of the housing lead, and has an end portion that protrudes beyond the open end and is exposed to the outside of the battery housing, and the welding tip portion may be heat-melted so that the open end, the first current collector plate, and the housing lead are integrally joined.

[0017] The first current collector plate is provided so that the welding tip portion surrounds the outer perimeter of the housing lead, and the housing lead may be configured to be positioned in the inner area of ​​the first current collector plate surrounded by the welding tip portion.

[0018] The above welding tip portion may be configured to elastically press the outer circumference of the housing lead.

[0019] The first collector plate comprises: a central portion extending in the radial direction; an outer portion offset axially from the central portion and located radially outside the central portion; and an inclined connecting portion connecting the central portion and the outer portion, wherein the welding tip portion may be bent at the end of the outer portion and extended in the axial direction.

[0020] The housing lead comprises: an inner lead portion extending radially; an outer lead portion offset axially from the inner lead portion and located radially outside the inner lead portion; and a connection lead portion connecting the inner lead portion and the outer lead portion, and may be configured so as to face and contact the central portion of the first current collector plate and the inner lead portion axially.

[0021] The central part of the first current collector plate and the electrode assembly may be configured to face and contact each other in the axial direction.

[0022] The electrode assembly may include a first non-removable portion extending from the first electrode, and may be configured such that the housing lead, the first current collector plate, and the first non-removable portion are triple-welded.

[0023] The outer portion of the first current collector plate may be configured to face and contact the outer lead portion of the housing lead in the axial direction and to be spaced apart from the electrode assembly in the axial direction.

[0024] The outer portion of the first collector plate has a projection formed protruding in the axial direction, and the outer lead portion of the housing lead may have a groove portion that matches the shape of the projection.

[0025] The above housing lead has an electrolyte injection hole in the center and a center hole facing the electrolyte injection hole in the center of the first current collector plate, and the center hole may be arranged to face a cavity in the center of the winding core provided in the electrode assembly in the axial direction.

[0026] The battery housing is provided with a closed portion on the axially opposite side of the open end, and a cell terminal electrically connected to a second electrode of the electrode assembly may be provided in the closed portion.

[0027] According to another aspect of the present invention, a battery pack comprising the battery cell described above may be provided.

[0028] According to another aspect of the present invention, an automobile comprising the battery pack described above may be provided.

[0029] According to one aspect of the present invention, unlike conventional battery cells, a battery cell can be provided in which a beading portion and a crimping portion are eliminated, the battery housing is sealed with a housing lead, and a current collector plate can be electrically connected.

[0030] In particular, according to one aspect of the present invention, by applying a lead assembly in which a housing lead and a current collector plate are pre-assembled, alignment between the battery housing, the housing lead, the current collector plate, and the electrodes of the electrode assembly is facilitated, and accordingly, the welding quality between the components can be improved.

[0031] The effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by a person skilled in the art from the description of the invention below.

[0032] FIG. 1 is a schematic perspective view of a battery cell according to one embodiment of the present invention.

[0033] Figure 2 is a schematic cross-sectional view of the battery cell of Figure 1.

[0034] FIG. 3 is a cross-sectional view illustrating the process of housing an electrode assembly according to one embodiment of the present invention in a battery housing.

[0035] FIG. 4 is a drawing showing an electrode assembly inserted into the battery housing of FIG. 3 and a second current collector plate attached thereto.

[0036] Figure 5 is a drawing showing the electrode assembly of Figure 4 turned upside down.

[0037] FIG. 6 is a cross-sectional view showing the process of seating a lead assembly in a battery housing into which an electrode assembly according to one embodiment of the present invention is inserted.

[0038] FIG. 7 is a perspective view of a lead assembly according to one embodiment of the present invention.

[0039] Figure 8 is an exploded perspective view of the lead assembly of Figure 7.

[0040] FIG. 9 is a cross-sectional view of a lead assembly according to A-A' of FIG. 7.

[0041] FIG. 10 is a partial enlarged view of FIG. 2, showing the welding structure between the battery housing, the first current collector plate, and the housing lead.

[0042] FIG. 11 is a drawing corresponding to FIG. 10, and is a drawing showing an assembly structure of a battery cell according to another embodiment of the present invention.

[0043] FIG. 12 is a cross-sectional view showing a part of the housing lead and a part of the first collector plate according to another embodiment of the present invention.

[0044] FIG. 13 is a combined view of the housing lead of FIG. 12 and the first collector plate.

[0045] FIG. 14 is a drawing for illustrating a battery pack including a battery cell according to one embodiment of the present invention.

[0046] FIG. 15 is a drawing for explaining a vehicle including the battery pack of FIG. 14.

[0047] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0048] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0049] FIG. 1 is a schematic perspective view of a battery cell according to one embodiment of the present invention, and FIG. 2 is a schematic cross-sectional view of the battery cell of FIG. 1.

[0050] Referring to FIGS. 1 and 2, a battery cell (10) according to one embodiment of the present invention includes an electrode assembly (100), a battery housing (200), a lead assembly (300), and a cell terminal (400).

[0051] The electrode assembly (100) comprises a first unwound section (110) and a second unwound section (120). Specifically, the electrode assembly (100) has a structure in which the first electrode and the second electrode and a separator interposed between them are wound around a winding axis to define a core and an outer surface. That is, the electrode assembly (100) applied to the present invention may be a jelly-roll type electrode assembly (100). In this case, an additional separator may be provided on the outer surface of the electrode assembly (100) to provide insulation from the battery housing (200). The electrode assembly (100) may have a winding structure well known in the art without limitation.

[0052] The first electrode comprises a first electrode current collector and a first electrode active material applied on one or both sides of the first electrode current collector. At one end of the first electrode in the width direction (the Z direction parallel to the height direction of the battery cell (10) shown in FIG. 2), there is a non-coated portion where the first electrode active material is not applied. That is, the first electrode includes a non-coated portion exposed to the outside of the separator, where the active material is not coated at the long end along the winding direction. The non-coated portion functioning as an electrode tab of the first electrode is hereinafter referred to as the first non-coated portion (110). The first non-coated portion (110) is provided on the upper side in the height direction (the Z direction parallel to the height direction of the battery cell (10) shown in FIG. 2) of the electrode assembly (100) housed within the battery housing (200). That is, the first electrode includes a first uncoated portion (110) that is exposed to the outside of the separator and has no active material layer coated on the long side end, and at least a portion of the first uncoated portion (110) is used as an electrode tab itself. The first uncoated portion (110) may be, for example, a negative electrode tab.

[0053] Meanwhile, at least a portion of the first bare portion (110) may include a plurality of segments divided along the winding direction of the electrode assembly (100). In this case, the plurality of segments may be bent along the radial direction of the electrode assembly (100). The bent plurality of segments may be overlapped in multiple layers. A first current collector plate (320) may be disposed on the upper portion of the first bare portion (110). For example, the first bare portion (110) and the first current collector plate (320) may be in contact, and at least one part of the contact may be welded.

[0054] The second electrode comprises a second electrode current collector and a second electrode active material coated on one or both sides of the second electrode current collector. At the other end of the second electrode current collector in the width direction (a direction parallel to the Z-axis), there exists a non-coated portion where the second electrode active material is not coated. The non-coated portion functioning as an electrode tab of the second electrode is hereinafter referred to as the second non-coated portion (120). The second non-coated portion (120) is located at the bottom of the electrode assembly (100) housed within the battery housing (200) in FIG. 2. That is, the second electrode current collector includes a second non-coated portion (120) that is exposed to the outside of the separator and where the active material layer is not coated at the long end, and at least a portion of the second non-coated portion (120) is used as an electrode tab itself. The second non-coated portion (120) may be, for example, a positive electrode tab.

[0055] Meanwhile, at least a portion of the second non-reinforced portion (120) may include a plurality of segments divided along the winding direction of the electrode assembly (100). In this case, the plurality of segments may be bent along the radial direction of the electrode assembly (100). The bent plurality of segments may be overlapped in multiple layers. A second current collector plate (340) may be disposed on the lower part of the second non-reinforced portion (120). For example, the second non-reinforced portion (120) and the second current collector plate (340) may be connected by welding.

[0056] The first non-removable portion (110) and the second non-removable portion (120) extend in opposite directions along the height direction of the battery (a direction parallel to the Z-axis). The first non-removable portion (110) extends toward the open end (210) of the battery housing (200), and the second non-removable portion (120) extends toward the closed portion (220) located opposite the open end (210).

[0057] Referring to FIGS. 1 to 3, the battery housing (200) may be configured to accommodate an electrode assembly (100). The battery housing (200) is a roughly cylindrical receptacle having an open end (210) formed on one side and is made of a conductive material, such as metal. The material of the battery housing (200) may be steel, stainless steel, or nickel-plated steel.

[0058] Specifically, the battery housing (200) may include a side wall portion, a closed portion (220) connected to one end of the side wall portion in the axial direction (Z direction), and an open portion (210) provided at the other end of the side wall portion in the axial direction. The side wall portion and the closed portion (220) of the battery housing (200) may be formed integrally. The closed portion (220) has a roughly flat shape. The side wall portion may be cylindrical, connected to the closed portion (220), and may extend in the axial direction. The side of the side wall portion that is not connected to the closed portion (220) may be defined as the open portion (210) of the battery housing (200). As shown in FIG. 3, the electrode assembly (100) may be housed in the internal space of the battery housing (200) through the open portion (210). At this time, the electrode assembly (100) can be accommodated inside the battery housing (200) such that the first non-removable portion (110) faces the open end (210) and the second non-removable portion (120) faces the closed portion.

[0059] The battery housing (200) is electrically connected to the first electrode of the electrode assembly (100). The battery housing (200) is electrically connected, for example, to the first non-electrode portion (110) of the electrode assembly (100). The battery housing (200) may be configured to be in direct contact with the first current collector plate (320) connected to the first non-electrode portion (110). In this case, the battery housing (200) has the same polarity as the first non-electrode portion (110).

[0060] The cell terminal (400) is made of a conductive metal material. For example, aluminum (Al) may be used as the material for the cell terminal (400). The cell terminal (400) is provided in a closed portion (220) located on the opposite side of the open end (210) of the battery housing (200) in FIG. 2. The cell terminal (400) is configured to be electrically connected to the second non-conducting portion (120) of the electrode assembly (100). For instance, as shown in FIG. 2, the second non-conducting portion (120) is connected to a second current collector, and the cell terminal may pass through the closed portion (220) axially to be connected to the second current collector. In this case, the cell terminal (400) has the same polarity as the second electrode. Therefore, the cell terminal (400) is electrically connected to the second electrode of the electrode assembly (100) and has the same second polarity as the second electrode. The cell terminal (400) is configured to be electrically connected to the first electrode and electrically insulated from the battery housing (200) having the first polarity.

[0061] Electrical insulation between the cell terminal (400) and the battery housing (200) can be achieved in various ways. For example, insulation can be achieved by interposing an insulator (224) between the second current collector plate (340) and the closed portion (220) of the battery housing (200), and by interposing an insulating gasket (223) between the cell terminal (400) and the battery housing (200). Alternatively, insulation can be achieved by forming an insulating coating layer on a part of the cell terminal (400). Alternatively, a method of structurally and firmly fixing the cell terminal (400) so that contact between the cell terminal (400) and the battery housing (200) is impossible may be applied. Alternatively, multiple methods among those described above may be applied together.

[0062] Meanwhile, in this embodiment, as illustrated in FIGS. 4 and 5, for example, the electrode assembly (100) is inserted into the battery housing (200) through the open end (210) with the second current collector plate (340) pre-welded to the second non-contact portion (120) and the first current collector plate (320) unwelded to the first non-contact portion (110). The open end (210) of the battery housing (200) can be sealed with a lead assembly (300) to be described later.

[0063] Specifically, as illustrated in FIG. 6, in the assembly process of the battery cell (10) according to the present embodiment, an electrode assembly (100) is inserted into the battery housing (200) such that the second current collector plate (340) has the second non-contact portion (120) facing the closed portion and the first non-contact portion (110) faces the open end (210), and then a lead assembly (300) is fitted into the open end (210). Here, the lead assembly (300) includes a housing lead (310) and a first current collector plate (320), and refers to an assembly in which the housing lead (310) and the first current collector plate (320) are pre-assembled and integrated.

[0064] In the case of a conventional battery cell (10), for example, a current collector plate is welded to the first non-conforming part (110) of an electrode assembly (100), and then inserted into a battery housing (200), and a housing lead (310) is inserted into the open end (210). Then, a second process is performed to weld between the battery housing (200) and the current collector plate and to weld between the battery housing (200) and the housing lead (310), or a first process is performed to weld the battery housing (200), the current collector plate, and the housing lead (310) together. However, regardless of how the welding is performed in such a conventional battery cell (10), if the alignment between the components is not correct, a problem may arise where the welding quality deteriorates, such as a failure to seal due to welding defects.

[0065] However, by applying the lead assembly (300) according to the present invention, alignment between the components can be done more easily and accurately. For example, since the lead assembly (300) according to the present invention is an assembly in which the housing lead (310) and the first current collector plate (320) are pre-assembled, the lead assembly (300) can be aligned and fitted into the open end (210) of the battery housing (200). In conventional battery cells, when assembling the housing lead to the battery housing, if the alignment between the housing lead and the battery housing, as well as the alignment between the housing lead and the current collector plate, is not accurately matched, the subsequent welding process cannot be performed smoothly. However, according to the present invention, as shown in FIG. 6, the lead assembly (300), in which the housing lead (310) and the first current collector plate (320) are pre-aligned and assembled, is seated on the open end (210) of the battery housing (200). In this case, alignment and welding between the components can be performed more easily and accurately during the process of assembling the housing lead (310) and the first current collector plate (320) to the battery housing (200) than in the conventional method.

[0066] FIG. 7 is a perspective view of a lead assembly according to one embodiment of the present invention, FIG. 8 is an exploded perspective view of the lead assembly of FIG. 7, FIG. 9 is a cross-sectional view of the lead assembly along A-A' of FIG. 7, and FIG. 10 is a partial enlarged view of FIG. 2 showing a welding structure between a battery housing, a first current collector plate, and a housing lead.

[0067] Referring to the drawings above, the lead assembly (300) according to the present invention includes a housing lead (310) and a first collector plate (320).

[0068] As shown in FIGS. 7 and 8, the lead assembly (300) may be configured such that the first collector plate (320) surrounds the outer perimeter of the housing lead (310), and the housing lead (310) is press-fitted into the inner area of ​​the first collector plate (320). Additionally, the lead assembly (300) may be configured such that the housing lead (310) and the first collector plate (320) come into face-to-face contact with each other.

[0069] The above lead assembly (300) is an assembly in which a housing lead (310) and a first collector plate (320) are pre-assembled and can be configured to be integrally seated in the battery housing (200). By using such a lead assembly (300), assembly tolerances caused by misalignment, such as the housing lead (310) being tilted up or down at a predetermined angle relative to the first collector plate (320) or rotated left or right, can be significantly reduced compared to the conventional method of inserting the first collector plate (320) and the housing lead (310) into the battery housing (200) individually.

[0070] More specifically, the first current collector plate (320) may include a center hole (325) that can communicate with the core hollow portion of the electrode assembly (100) as shown in FIGS. 8 and 9, a central portion (321) that extends radially with respect to the center hole (325), an outer portion (322) that is offset axially (Z direction) from the central portion (321) and is located radially outside the central portion (321), an inclined connecting portion (323) that connects the central portion (321) and the outer portion (322), and a welding tip portion (324) that is bent at the end of the outer portion (322) and extends axially.

[0071] And the housing lead (310) may include an inner lead portion (311) extending in a radial direction, an outer lead portion (312) offset in an axial direction (Z direction) from the inner lead portion (311) and located radially outside the inner lead portion (311), and a connection lead portion (313) connecting the inner lead portion (311) and the outer lead portion (312).

[0072] When the housing lead (310) is press-fitted onto the first collector plate (320), as shown in FIG. 9, the central portion (321) of the first collector plate (320) and the inner lead portion (311) may be configured to face each other in the axial direction and come into contact with each other. Additionally, the outer portion (322) of the first collector plate (320) may be configured to face each other in the axial direction and come into contact with the outer lead portion (312) of the housing lead (310).

[0073] Additionally, the welding tip portion (324) of the first current collector plate (320) may be provided in an annular ring shape at the outermost edge of the first current collector plate (320) and configured to surround the outer circumference of the housing lid (310). The welding tip portion (324) may be configured to elastically press the outer circumference of the housing lid (310) when the housing lid (310) is placed in the inner region of the first current collector plate (320) surrounded by the welding tip portion (324). Accordingly, the housing lid (310) and the first current collector plate (320) can be fixed in close contact with each other. When such a lid assembly (300) is inserted into the battery housing (200), the housing lid (310) does not tilt or rotate in the up-and-down direction relative to the first current collector plate (320). Therefore, when the lead assembly (300) is inserted into the battery housing (200), there is no need to specifically check for an alignment error between the housing lead (310) and the first current collector plate (320).

[0074] Meanwhile, the housing lid (310) according to the present embodiment may be provided with a vent notch (317) configured to rupture when the pressure inside the battery housing (200) exceeds a critical value. For example, the vent notch (317) may be formed on both sides of the housing lid (310) and may be formed as at least one of a continuous circular pattern, a discontinuous circular pattern, and a straight line pattern on the surface of the housing lid (310). Additionally, the vent notch (231) may be formed in various other patterns.

[0075] Next, we will examine the welding structure of the battery cell (10) according to the present embodiment.

[0076] Referring to FIG. 2 and FIG. 10, when the lead assembly (300) is inserted into the battery housing (200), the central portion (321) of the first current collector plate (320) may face and contact the electrode assembly (100) in the axial direction, and the outer portion (322) of the first current collector plate (320) may be spaced apart from the electrode assembly (100) by 'D2' in the axial direction.

[0077] The first current collector plate (320) of the lead assembly (300) may be positioned to contact a first non-circulating portion (110) extending from the first electrode of the electrode assembly (100). Accordingly, the first current collector plate (320) may be electrically connected to the first electrode.

[0078] Additionally, the housing lead (310), the first collector plate (320), and the first non-coupling portion (110) can be triple-welded. That is, the inner lead portion of the housing lead (310), the central portion (321) of the first collector plate (320), and the first non-coupling portion (110) of the first electrode can be welded together. As described above, the inner lead portion (311) and the central portion (321) are in close contact, and the inner lead portion (311) and the first non-coupling portion (110) are arranged to be in contact, so that the inner lead portion, the central portion (321), and the first non-coupling portion (110) can be welded by irradiating a laser from the outside of the battery cell (10), for example, as indicated by 'W2' in FIG. 10.

[0079] In addition, in the case of the battery cell (10) according to the present embodiment, since the housing lead (310) and the first current collector plate are in close contact, when heat is generated in the electrode assembly (100), the heat can be conducted to the housing lead (310) more quickly. Therefore, if a cooling means (not shown) is placed on the housing lead (310), the heat of the electrode assembly can be dissipated more efficiently.

[0080] Additionally, the battery housing (200), the housing lead (310), and the first current collector plate (320) can be triple welded.

[0081] As illustrated in FIG. 10, when the lead assembly (300) is inserted into the battery housing (200), the weld tip portion (324) of the first collector plate (320) may be positioned so that it contacts the inner surface (211) of the open end (210) and the outer surface (312a) of the housing lead (310), and the end protrudes beyond the open end (210) and is exposed to the outside as indicated by 'D1'.

[0082] Triple welding between the battery housing (200), the housing lead (310), and the first current collector plate (320) can be performed by thermally melting the welding tip portion (324) so ​​that the open end (210) of the battery housing (200), the first current collector plate (320), and the housing lead (310) are joined as a single unit. For example, a laser can be irradiated from outside the battery cell (10) onto the welding tip portion (324) to melt the welding tip portion (324), as indicated by 'W1' in FIG. 10, thereby joining the open end (210) and the housing lead (310). At this time, as the welding tip portion (324) melts, it can be filled into the gap that may occur when the lead assembly (300) is seated on the open end (210) of the battery housing (200), thereby increasing airtightness through a gap-filling effect. In addition, since welding is performed by melting only the first collector plate (320), there is an advantage that welding can be performed at a low output. In particular, according to this embodiment, the outer portion (322) of the first collector plate (320) is separated from the first non-coupling portion (110) by 'D2', and furthermore, the welding tip portion (324) can be welded at a low output, so the risk of damage to the first non-coupling portion (110) due to welding heat can be significantly reduced.

[0083] Meanwhile, the housing lead (310) may be provided with an electrolyte injection hole (314) in the center of the inner lead portion (311). The electrolyte injection hole (314) may be formed to penetrate the inner lead portion (311) of the housing lead (310) so as to face a cavity formed in the center of the winding core of the electrode assembly (100). A center hole (325) facing the electrolyte injection hole (314) may be provided in the center of the first current collector plate (320). The center hole (325) may be formed to penetrate the central portion (321) of the first current collector plate (320).

[0084] For example, as described above, welding between the battery housing (200), the housing lead (310), and the first current collector plate (320), and welding between the housing lead (310), the first current collector plate (320), and the first non-container portion (110) can be performed, and then the electrolyte can be injected into the battery housing (200) through the electrolyte injection hole (314) and the center hole (325). After the electrolyte injection is completed, the electrolyte injection hole (314) can be closed. For example, the electrolyte injection hole (314) can be covered by a lead hole cap (330) provided in the form of a metal disc, and the circumference of the lead hole cap (330) can be welded to ensure airtightness.

[0085] Although not illustrated, unlike the present embodiment, the electrolyte injection hole (314) may be closed by pressing a ball into the electrolyte injection hole (314). In this case, welding may be performed or an adhesive may be applied to the contact interface between the ball and the electrolyte injection hole (314). Meanwhile, unlike the present embodiment, the electrolyte injection may be performed by making a terminal hole in the cell terminal (400) provided in the closed part of the battery housing (200), injecting the electrolyte, and closing the terminal hole. In this case, the electrolyte injection hole (314) does not need to be formed in the housing lid (310).

[0086] Next, a battery cell (10) according to another embodiment of the present invention will be described.

[0087] FIG. 11 is a drawing corresponding to FIG. 10, showing an assembly structure of a battery cell (10) according to another embodiment of the present invention, FIG. 12 is a cross-sectional view showing a part of a housing lead (310) and a part of a first current collector plate (320) according to another embodiment of the present invention, and FIG. 13 is a combined view of the housing lead (310) and the first current collector plate (320) of FIG. 12.

[0088] Reference numbers identical to those in previous drawings indicate identical components. Duplicate descriptions of identical components will be omitted, and the explanation will focus on the differences from the previously described embodiments.

[0089] A battery cell (10) according to another embodiment of the present invention differs from the above-described embodiment in the assembly structure of the lead assembly (300), and the rest of the configuration is the same.

[0090] A lead assembly (300) according to another embodiment of the present invention, as shown in FIG. 12, has a projection (327) formed axially on the outer portion (322) of the first collector plate (320), and a groove (318) that is shaped to match the projection (327) on the outer lead portion (312) of the housing lead (310).

[0091] The above protrusion (327) and the above groove (318) can function as an assembly guide to guide the assembly position so that the housing lead (310) and the first collector plate (320) can be assembled to each other at an accurate position. In addition, the above protrusion (327) and the above groove (318) can function as a stopper to suppress relative movement after the housing lead (310) and the first collector plate (320) are assembled.

[0092] For example, as illustrated in FIG. 12, the housing lead (310) can be seated on the first collector plate (320) such that the groove (318) of the housing lead (310) fits into the projection (327) of the first collector plate (320) while the welding tip portion (324) of the first collector plate (320) is opened. After the housing lead (310) is seated on the first collector plate (320), the welding tip portion (324) can be returned to its original state so that the outer circumference of the housing lead (310) is elastically compressed. Then, the housing lead (310) and the first collector plate (320) can be stably fixed to each other. As described above, after assembling the lead assembly (300) to the open end (210) of the battery housing (200) such that the welding tip portion (324) protrudes outwardly from the open end (210) of the battery housing (200), the welding tip portion (324) is melted to join the battery housing (200), the housing lead (310), and the first current collector plate (320) together, thereby reducing the number of welding steps while ensuring sufficient airtightness of the battery housing (200).

[0093] The battery cell (10) described above can be housed in the housing (2) of the battery pack (1) as shown in FIG. 14. The battery pack (1) may be constructed using a battery module, which is an intermediate form of assembly, or may be constructed directly without a battery module as shown. As in the present embodiment, the battery pack (1) in which the battery cell (10) is housed directly in the housing of the battery pack without a battery module can be realized with a higher energy density.

[0094] A battery pack (1) with such increased energy density can store the same amount of energy while reducing its volume and weight. Therefore, if a battery pack (1) with such battery cells (10) is installed in a vehicle, such as a car that uses electricity as an energy source as shown in FIG. 15, the vehicle's mileage relative to energy can be further increased.

[0095] An automobile according to one embodiment of the present invention includes a battery pack (1) according to one embodiment of the present invention. The automobile may be configured to operate by receiving power from the battery pack (1) according to one embodiment of the present invention.

[0096] The embodiments described above should be understood as exemplary in all respects and not limiting, and the scope of the invention will be defined by the claims set forth below rather than by the detailed description above. Furthermore, the meaning and scope of the claims set forth below, as well as all modifications and variations derived from equivalents thereof, should be interpreted as being included within the scope of the invention.

[0097] Although the present invention has been described above with reference to the illustrated drawings, the present invention is not limited by the embodiments and drawings disclosed in this specification, and it is obvious that various modifications can be made by a person skilled in the art within the scope of the technical concept of the present invention. Furthermore, even if the effects of the configuration according to the present invention were not explicitly described while describing the embodiments of the present invention above, it is natural to acknowledge that the effects predictable by said configuration should also be recognized.

Claims

1. An electrode assembly comprising a first electrode and a second electrode and a separator interposed between them, wound around a winding axis; A battery housing having an open end so that the electrode assembly is inserted therein; and A battery cell characterized by comprising a housing lead configured to seal the open end and a first current collector plate detachably assembled to the housing lead, and a lead assembly seated at the open end such that the first current collector plate is electrically connected to the first electrode.

2. In Paragraph 1, The above lead assembly is, A battery cell characterized in that the first current collector plate surrounds the outer perimeter of the housing lead, and the housing lead is configured to be press-fitted into the inner region of the first current collector plate.

3. In Paragraph 1, The above lead assembly is, A battery cell characterized by the above housing lead and the above first current collector plate being configured to come into face-to-face contact and stick together.

4. In Paragraph 1, The first current collector plate has a welded tip portion that contacts the inner surface of the open end and the outer surface of the housing lid, and whose end protrudes beyond the open end and is exposed to the outside of the battery housing. A battery cell characterized by the fact that the above-mentioned welding tip portion is heat-melted to integrally join the above-mentioned open end, the above-mentioned first current collector plate, and the above-mentioned housing lead.

5. In Paragraph 4, The first current collector plate is arranged so that the welding tip portion surrounds the outer perimeter of the housing lead, and A battery cell characterized in that the housing lead is configured to be positioned in the inner region of the first current collector plate surrounded by the welding tip portion.

6. In Paragraph 4, A battery cell characterized by the above-mentioned welding tip portion being configured to elastically press the outer circumference of the housing lead.

7. In Paragraph 4, The first collector plate comprises: a central portion extending in a radial direction; an outer portion offset axially from the central portion and located radially outside the central portion; and an inclined connecting portion connecting the central portion and the outer portion. A battery cell characterized in that the welding tip portion is bent at the end of the outer portion and extended in the axial direction.

8. In Paragraph 7, The housing lead comprises: an inner lead portion extending radially; an outer lead portion offset axially from the inner lead portion and located radially outside the inner lead portion; and a connection lead portion connecting the inner lead portion and the outer lead portion. A battery cell characterized by the central portion of the first current collector plate and the inner lead portion being configured to face and contact each other in the axial direction.

9. In Paragraph 8, A battery cell characterized in that the central part of the first current collector plate and the electrode assembly are configured to face and contact each other in the axial direction.

10. In Paragraph 9, The electrode assembly includes a first non-removable portion extending from the first electrode, and A battery cell characterized by the above housing lead, the above first collector plate, and the above first non-removable portion being triple-welded.

11. In Paragraph 8, A battery cell characterized in that the outer portion of the first current collector plate faces and contacts the outer lead portion of the housing lead in the axial direction and is spaced apart from the electrode assembly in the axial direction.

12. In Paragraph 8, The outer portion of the first collector plate has a projection formed protruding in the axial direction, and A battery cell characterized in that the outer lead portion of the housing lead has a groove portion that matches the shape of the projection.

13. In Paragraph 1, The above housing lead is provided with an electrolyte injection hole in the center. The center of the first current collector plate is provided with a center hole facing the electrolyte injection hole, A battery cell characterized in that the center hole is positioned to face a cavity in the center of the winding core provided in the electrode assembly in the axial direction.

14. In Paragraph 1, A battery cell characterized in that the battery housing has a closed portion on the axially opposite side of the open end, and the closed portion is provided with a cell terminal electrically connected to the second electrode of the electrode assembly.

15. A battery pack characterized by including at least one battery cell described in any one of claims 1 to 14.

16. An automobile comprising the battery pack described in paragraph 15.

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