Battery cell, and battery pack and vehicle comprising same

Abstract

A battery cell according to an embodiment of the present invention comprises: an electrode assembly in which a first electrode, a second electrode, and a separator interposed therebetween are wound around a winding axis to define a core and an outer circumferential surface, wherein the first electrode comprises a first uncoated portion along which no active material layer is coated in the winding direction; a housing which comprises an open portion on one side, is configured to receive the electrode assembly through the open portion, and comprises a closed portion located on the opposite side of the open portion and having a through-hole formed through at least a portion thereof; and a current collector which is coupled to one end of the electrode assembly, has the same polarity as the first electrode, and is exposed to the outside through the through-hole.

Description

Battery cells and battery packs including the same and automobiles

[0001] The present invention relates to a battery cell, a battery pack including the same, and an automobile.

[0002] This application is a priority claim application for Korean Patent Application No. 10-2025-0009652 filed on January 22, 2025, and all contents disclosed in the specification and drawings of said application are incorporated into this application by reference.

[0003] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, as they possess not only the primary advantage of drastically reducing the use of fossil fuels but also the advantage of generating no by-products from energy use.

[0004] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage and / or charge / discharge capacity.

[0005] Meanwhile, in some models of conventional cylindrical battery cells, an ultrasonic welding process such as Continuous Resistance Welding (CRW) is performed between the non-conductive portion of the electrode assembly and the current collector plate. However, issues such as separator damage and reduced battery capacity and lifespan are arising due to spatter generated during such CRW welding.

[0006] Furthermore, conventional cylindrical battery cells have faced limitations in increasing the energy density of the electrode assembly because it is difficult to reduce the diameter of the welding horn tip during CRW welding. Specifically, there is a problem where the volume inside the battery can is occupied due to the presence of rivets and insulators.

[0007] Meanwhile, as battery development advances, the issue of cost reduction is also emerging; however, conventional battery cells are facing difficulties in reducing costs due to the diverse and complex shapes of components and complex manufacturing processes.

[0008] Accordingly, the present invention has the objective of preventing damage to the separator and simultaneously preventing a decrease in battery capacity and battery life by preventing fragments from entering the battery cell during the welding process of the battery cell.

[0009] In another aspect, the present invention has another objective of increasing energy density by reducing dead space within the cell by reducing the number of unnecessary parts in the battery cell.

[0010] Furthermore, another objective of the present invention is to reduce manufacturing costs by omitting the number of parts, etc.

[0011] However, 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 a person skilled in the art from the description of the invention below.

[0012] A battery cell according to an embodiment of the present invention for solving the above-mentioned problem comprises: an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis to define a core and an outer surface, wherein the first electrode includes a first uncoated portion in which an active material layer is not coated along the winding direction; a housing including a closed portion having an opening on one side and configured to accommodate the electrode assembly through the opening, and having a through hole located on the opposite side of the opening and having at least a portion of the area drilled; and a current collector coupled to one end of the electrode assembly, having the same electrode as the first electrode, and configured to be exposed to the outside through the through hole.

[0013] In one aspect of the present invention, the current collector may include: a horizontal extension portion disposed on the upper part of the electrode assembly and configured to face the first non-removable portion; a terminal portion located at the center of the horizontal extension portion and exposed to the outside of the housing; and a rivet portion protruding from the horizontal extension portion and bent and extended to wrap around the housing.

[0014] Preferably, the horizontal extension may include a non-reinforcement portion configured to be coupled to the first non-reinforcement portion.

[0015] At this time, the above-mentioned non-reinforced joint portion may be provided in an area within the region of the above-mentioned horizontal extension portion that is located radially inward from the rivet portion.

[0016] In another aspect of the present invention, the first non-removable portion and the current collector may be configured to be welded together on the outside of the battery cell.

[0017] In another aspect of the present invention, the rivet portion may be inserted into the through hole of the housing.

[0018] In one aspect of the present invention, the rivet portion may include a first part extending perpendicularly from the horizontal extension portion toward the outside of the battery cell from the horizontal extension portion; and a second part bent from the end of the first part and extending parallel to the closure portion.

[0019] Preferably, the above-mentioned non-bonded portion may be provided with at least one first welded portion formed by welding the first non-bonded portion.

[0020] At this time, the first weld can be configured as a circle based on the winding center.

[0021] In another aspect of the present invention, an insulating gasket interposed between the housing and the current collector may be provided on the closed side of the housing.

[0022] Preferably, the insulating gasket may include a gasket exposure portion interposed between the rivet portion and the housing; and a gasket insertion portion interposed between the horizontal extension portion of the current collector and the housing.

[0023] More preferably, the length of the gasket exposure portion may be configured to be equal to or longer than the length of the rivet portion.

[0024] In one aspect of the present invention, the end of the gasket insertion portion may be located radially further outward than the end of the horizontal extension portion of the current collector.

[0025] Meanwhile, the present invention provides a battery pack comprising at least one battery cell according to the above-described embodiment as a battery pack.

[0026] In addition, the present invention provides a vehicle comprising at least one battery pack according to the above-described embodiment.

[0027] According to the present invention, it is possible to prevent fragments from entering the battery cell during the welding process of the battery cell. Accordingly, damage to the separator can be prevented, and at the same time, a reduction in battery capacity and battery life can be prevented.

[0028] In addition, according to the present invention, energy density can be improved by reducing dead space within the cell by reducing the number of unnecessary parts in the battery cell.

[0029] Furthermore, according to the present invention, manufacturing costs can be reduced by omitting the number of parts, etc.

[0030] However, 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.

[0031] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings.

[0032] FIG. 1 is a drawing for explaining a battery cell according to one embodiment of the present invention.

[0033] Figure 2 is a longitudinal section of Figure 1.

[0034] FIG. 3 is a drawing for explaining an electrode assembly included in a battery cell according to one embodiment of the present invention.

[0035] FIG. 4 is an enlarged cross-sectional view of the upper part of the battery cell of FIG. 1, and is a drawing to explain the process of inserting the current collector into the housing.

[0036] FIG. 5 is an enlarged cross-sectional view of the upper part of the battery cell of FIG. 1, and is a drawing to explain the state in which the current collector is riveted after being inserted into the housing.

[0037] FIG. 6 is an enlarged cross-sectional view of the upper part of the battery cell of FIG. 1, and is a drawing to explain the state in which the current collector is welded to the electrode assembly.

[0038] FIG. 7 is a drawing for illustrating a current collector according to another embodiment of the present invention.

[0039] FIG. 8 is a drawing for explaining the combined state of an electrode assembly and a lower cap according to one embodiment of the present invention.

[0040] FIG. 9 is a drawing for explaining a battery pack including the battery cell of FIG. 1.

[0041] FIG. 10 is a drawing for explaining a vehicle including the battery pack of FIG. 9.

[0042] 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.

[0043] 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.

[0044] The statement that two subjects of comparison are identical means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0045] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0046] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0047] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0048] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0049] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0050] For convenience of explanation, in this specification, the direction following the length direction of the winding axis of the electrode assembly (10) wound in a jelly roll shape is referred to as the axial direction. The direction surrounding the winding axis is referred to as the circumferential direction or the periphery direction. The direction approaching the winding axis or moving away from the winding axis is referred to as the radial direction. In particular, the direction approaching the winding axis is referred to as the centripetal direction, and the direction moving away from the winding axis is referred to as the centrifugal direction.

[0051]

[0052] FIG. 1 is a drawing for explaining a battery cell (1) according to one embodiment of the present invention, and FIG. 2 is a cross-sectional view of FIG. 1.

[0053] Referring to FIGS. 1 and 2, a battery cell (1) according to one embodiment of the present invention may be, for example, a cylindrical battery cell. The cylindrical battery cell (1) includes an electrode assembly (10), a housing (20), and a current collector (30).

[0054] The above-described cylindrical battery cell (1) may additionally include an insulating gasket (40) and / or a bottom cap (50) in addition to the components described above. The present invention is not limited by the shape of the battery and is applicable to batteries of other shapes, such as prismatic batteries.

[0055]

[0056] FIG. 3 is a drawing for explaining an electrode assembly (10) included in a battery cell (1) according to one embodiment of the present invention.

[0057] Referring to FIG. 3, the electrode assembly (10) includes a first electrode having a first polarity, a second electrode having a second polarity, and a separator interposed between the first electrode and the second electrode. The first electrode is a negative electrode or a positive electrode, and the second electrode corresponds to an electrode having a polarity opposite to that of the first electrode.

[0058] The electrode assembly (10) may have, for example, a jelly-roll structure. That is, the electrode assembly (10) may be manufactured by winding a laminate formed by stacking a first electrode plate and a second electrode plate having a sheet shape at least once with a separator interposed between them in one direction with respect to the winding center. In this case, an additional separator may be provided on the outer surface of the electrode assembly (10) to insulate it from the housing (20). Any structure of a wound electrode assembly (10) known in the art may be applied to the present invention without limitation.

[0059] The first electrode comprises a first electrode plate and a first electrode active material applied on one or both sides of the first electrode plate. The first electrode includes a first uncoated portion (11) in which the active material layer is not coated along the winding direction. That is, an uncoated portion in which the first electrode active material is not coated exists at one end in the width direction (direction parallel to the Z-axis) of the first electrode plate. The uncoated portion functioning as a first electrode tab will be referred to as the first uncoated portion (11) below. The first uncoated portion (11) is provided on the upper side in the height direction (direction parallel to the Z-axis) of the electrode assembly (10) housed within the housing (20). That is, the first electrode plate includes a first uncoated portion (11) in which the active material layer is not coated at the long end and is exposed to the outside of the separator, and a part of the first uncoated portion (11) is used as an electrode tab itself. The first uncoated portion (11) may be, for example, an anode tab.

[0060] Meanwhile, at least a portion of the first non-reinforced portion (11) may include a plurality of segments (11a) divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments (11a) may be folded along the radial direction of the electrode assembly (10). The folded plurality of segments (11a) may be overlapped in multiple layers. In this case, the non-reinforced portion coupling portion (310) (310), which will be described later, may be coupled to the area where the plurality of segments (11a) are overlapped in multiple layers.

[0061] The second electrode comprises a second electrode plate and a second electrode active material applied on one or both sides of the second electrode plate. At the other end of the second electrode plate in the width direction (direction parallel to the Z-axis), there exists a non-exposed portion where the second electrode active material is not applied. The non-exposed portion functioning as a second electrode tab is hereinafter referred to as the second non-exposed portion (12). The second non-exposed portion (12) is provided at the lower end in the height direction (direction parallel to the Z-axis) of the electrode assembly (10) housed within the housing (20). That is, the second electrode plate includes a second non-exposed portion (12) 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-exposed portion (12) is used as an electrode tab itself. The second non-exposed portion (12) may be, for example, a negative electrode tab.

[0062] Meanwhile, at least a portion of the second non-reinforced portion (12) may include a plurality of segments (12a) divided along the winding direction of the electrode assembly (10). In this case, the plurality of segments (12a) may be bent along the radial direction of the electrode assembly (10). The bent plurality of segments (12a) may be overlapped in multiple layers. In this case, the lower cap (50) described later may be coupled to the area where the plurality of segments (12a) are overlapped in multiple layers.

[0063] The first non-removable portion (11) and the second non-removable portion (12) extend in opposite directions along the height direction (a direction parallel to the Z-axis) of the cylindrical battery cell (1). For example, referring to FIG. 2, the first non-removable portion (11) may extend toward the closed portion (22) of the housing (20), and the second non-removable portion (12) may extend toward the open portion (21) of the housing (20).

[0064] Meanwhile, in the present invention, the positive active material coated on the positive plate and the negative active material coated on the negative plate may be used without limitation as long as they are active materials known in the art.

[0065]

[0066] Referring again to FIGS. 1 and 2, the housing (20) may be composed of a roughly cylindrical receptacle with an opening (21) formed on one side. The housing (20) is made of a conductive material, such as metal, for example. For the material of the housing (20), steel, stainless steel, or nickel-plated steel may be used, for example. The upper surface located opposite the opening (21) is referred to as the closed portion (22).

[0067] The closure portion (22) is located on the opposite side of the opening portion (21). For example, referring to FIGS. 1 and 2, the opening portion (21) of the housing (20) may be located at the bottom of the battery cell (1). In this case, the closure portion (22) of the housing (20) is located at the top of the battery cell (1). The closure portion (22) may have a through hole (22H) in which at least a portion of the area is open. In one aspect of the present invention, the through hole (22H) may be provided in the approximately central area of ​​the closure portion (22). In another aspect of the present invention, the through hole (22H) may be configured to be approximately circular. Of course, the shape of the through hole (22H) is not limited thereto.

[0068] The side wall portion and the closure portion (22) of the housing (20) may be formed integrally. Alternatively, the side wall portion and the closure portion (22) of the housing (20) may be provided separately from each other and joined together by welding or the like. The upper surface of the housing (20) (a surface parallel to the XY plane), that is, the outer surface of the closure portion (22), may have a roughly flat shape. The housing (20) may accommodate an electrode assembly (10) through an opening (21) formed on one side.

[0069] The housing (20) is electrically connected to the electrode assembly (10). The housing (20) may be electrically connected, for example, to the second non-electrode portion (12) of the electrode assembly (10). In this case, the housing (20) has the same polarity as the second non-electrode portion (12).

[0070] Meanwhile, the side wall portion of the housing (20) may be composed of a cylinder with a constant diameter. That is, unlike the housing (20) of other conventional cylindrical battery cells (1), the housing (20) according to one embodiment of the present invention does not include a beading portion or a crimping portion. Accordingly, according to the present invention, unnecessary dead space in the vertical direction can be reduced, and thus energy density can be improved.

[0071]

[0072] FIG. 4 is an enlarged cross-sectional view of the upper part of the battery cell (1) of FIG. 1, and is a drawing to explain the process of inserting the current collector (30) into the housing (20), and FIG. 5 is an enlarged cross-sectional view of the upper part of the battery cell (1) of FIG. 1, and is a drawing to explain the state of the current collector (30) being riveted after being inserted into the housing (20).

[0073] Referring to FIGS. 4 and 5, the current collector (30) is coupled to the upper part of the electrode assembly (10). The current collector (30) may be made of a conductive metal material. The current collector (30) may be connected to the first non-conductive portion (11). More specifically, the current collector (30) is electrically connected to the first non-conductive portion (11). The current collector (30) may be coupled to a coupling surface formed by bending the end of the first non-conductive portion (11) in a direction parallel to the current collector (30). For example, the current collector (30) may be coupled to a coupling surface formed by bending a segment (11a) of the first non-conductive portion (11) in a direction parallel to the current collector (30). For example, referring to FIGS. 4 and 5, the current collector (30) may be coupled to the upper part of the electrode assembly (10). In this case, the current collector (30) has the same polarity as the first electrode.

[0074] In one aspect of the present invention, the material of the current collector (30) may be, for example, aluminum (Al). With such a configuration, processing is facilitated during riveting. Meanwhile, the current collector (30) may be made of 10 series aluminum, which has relatively low electrical resistance.

[0075] In another aspect of the present invention, the current collector (30) may be configured to be exposed to the outside. For example, the current collector (30) may be configured to be exposed to the outside through a through hole (22H) of the housing (20). Here, "outside" means the outside of the battery cell (1). That is, the current collector (30) may have an outside-facing surface and an inside-facing surface, the inside-facing surface may be in contact with and / or coupled with the electrode assembly (10), and the outside-facing surface may be exposed to the outside of the battery cell (1).

[0076] According to this configuration, the first non-removable portion (11) and the current collector (30) can be welded outside the battery cell (1), so even if spatter is generated during welding, the spatter does not enter the interior of the battery cell (1). Accordingly, issues such as damage to the separator and reduction in battery capacity and lifespan caused by spatter during welding can be resolved. In addition, according to the present invention, since the welding is performed outside the battery cell (1), a welding horn tip is not required, so the diameter of the winding center hole of the electrode assembly (10) can be reduced, and thus the energy density can be improved.

[0077]

[0078] In another aspect of the present invention, the current collector (30) may include a horizontal extension part (31), a terminal part (32), and a rivet part (33).

[0079] A horizontal extension (31) may be positioned on the upper part of the electrode assembly (10). The horizontal extension (31) may be configured to face the first non-removable portion (11). The horizontal extension (31) may be configured to have a roughly plate shape extending in a horizontal direction. For example, the shape of the horizontal extension (31) may be configured to be a roughly circular shape. The lower surface of the horizontal extension (31) may be contacted and coupled with the electrode assembly (10) in a state facing one end of the electrode assembly (10).

[0080] Specifically, the lower surface of the horizontal extension (31) may be connected to a connecting surface formed by bending the end of the first non-removable portion (11) in a direction parallel to the current collector (30). More specifically, the lower surface of the horizontal extension (31) may be connected to a connecting surface formed by bending the segment (11a) of the first non-removable portion (11) in a direction parallel to the current collector (30). At least a portion of the upper surface of the horizontal extension (31) may be configured to be exposed to the outside of the battery cell (1).

[0081] The above horizontal extension portion (31) may include a non-reinforced portion coupling portion (310) configured to be coupled with the first non-reinforced portion (11). That is, the lower surface of the non-reinforced portion coupling portion (310) may be coupled to a coupling surface formed by bending the end of the first non-reinforced portion (11) in a direction parallel to the current collector (30). More specifically, the lower surface of the non-reinforced portion coupling portion (310) may be coupled to a coupling surface formed by bending the segment (11a) of the first non-reinforced portion (11) in a direction parallel to the current collector (30). At least a portion of the upper surface of the non-reinforced portion coupling portion (310) may be configured to be exposed to the outside of the battery cell (1).

[0082] In one aspect of the present invention, the first non-removable portion (11) and the current collector (30) may be configured to be welded together outside the battery cell (1). More specifically, the first non-removable portion (11) and the current collector (30) may be configured to be welded together through the upper surface of the horizontal extension portion (31). That is, the first non-removable portion (11) and the non-removable portion joining portion (310) may be configured to be welded together outside the battery cell (1).

[0083] According to this configuration, the first non-removable portion (11) and the current collector (30) can be welded outside the battery cell (1), so even if fragments are generated during welding, the fragments do not enter the interior of the battery cell (1). Accordingly, issues such as damage to the separator and reduction in battery capacity and lifespan caused by fragments during welding can be resolved. In addition, according to the present invention, since the welding is performed outside the battery cell (1), a welding horn tip is not required, so the diameter of the winding center hole of the electrode assembly (10) can be reduced, and thus the energy density can be improved.

[0084]

[0085] In another aspect of the present invention, the terminal portion (32) may be located at the center of the horizontal extension portion (31). The terminal portion (32) may be exposed to the outside of the housing (20). The terminal portion (32) may be configured to have the same electrode as the first electrode. In this case, the terminal portion (32) may function as the first electrode terminal. In this case, the terminal portion (32) is electrically insulated from the housing (20) having the second polarity.

[0086] Meanwhile, the terminal portion (32) may be configured to have, for example, a roughly cylindrical shape. That is, the terminal portion (32) may have a structure protruding in the direction of the winding axis from the horizontal extension portion (31). Specifically, the terminal portion (32) may protrude from the horizontal extension portion (31) in a direction parallel to the winding axis and toward the outside of the battery cell (1). For example, referring to FIG. 1, the terminal portion (32) may have a structure protruding upward from the battery cell (1).

[0087]

[0088] In another aspect of the present invention, the rivet portion (33) may protrude from the horizontal extension portion (31). The rivet portion (33) may be bent and extended to wrap around the housing (20). The rivet portion (33) may be provided in the area between the terminal portion (32) and the end of the horizontal extension portion (31). For example, referring to FIG. 4, the rivet portion (33) may be provided in the approximately middle area of ​​the area between the end of the horizontal extension portion (31).

[0089] At this time, the non-reinforced coupling portion (310) may be provided in an area of ​​the horizontal extension portion (31) that is located radially inward from the rivet portion (33). For example, referring to FIG. 4, the non-reinforced coupling portion (310) may be provided in an area between the terminal portion (32) and the rivet portion (33). With the rivet portion (33) as the center, the radially inward area may be exposed to the outside of the battery cell (1), and the radially outward area may be inserted into the inside of the battery cell (1).

[0090] The above rivet portion (33) can be inserted into the through hole (22H) of the housing (20). At this time, a gasket, which will be described later, can also be inserted into the through hole (22H) of the housing (20). In this case, the gasket can be interposed between the rivet portion (33) and the through hole (22H).

[0091]

[0092] In one aspect of the present invention, the rivet portion (33) may include a first part (331) and a second part (332).

[0093] The first part (331) may extend perpendicularly from the horizontal extension (31) toward the outside of the battery cell (1). That is, the first part (331) may extend in a direction parallel to the winding axis. For example, the first part (331) may be configured to have a hollow pipe shape. However, the shape of the first part (331) is not limited to this, and any shape that is hollow and extends in the direction of the winding axis is considered to be included within the scope of the present invention.

[0094] The second part (332) may be bent from the end of the first part (331). The bent second part (332) may be extended parallel to the closure (22). That is, the second part (332) may be extended in a horizontal direction.

[0095] According to the above configuration, the number of parts can be reduced compared to conventional battery cells. Accordingly, cost reduction can be achieved. For example, by configuring the structure of the current collector (30) as described above, the present invention can reduce the number of parts by combining the current collector plate and terminal of a conventional battery cell (1) into a single part. Due to the above configuration, components such as a top insulator become unnecessary, thereby enabling further reduction in the number of parts and cost reduction. That is, according to the above configuration, the top insulator, the positive current collector plate, and the negative current collector plate can all be omitted, thereby increasing the total height of the electrode assembly (10). Ultimately, according to the present invention, energy density can be further improved.

[0096]

[0097] FIG. 6 is an enlarged cross-sectional view of the upper part of the battery cell (1) of FIG. 1, and is a drawing to explain the state in which the current collector (30) is welded to the electrode assembly (10).

[0098] In another aspect of the present invention, referring to FIG. 6, the non-bonded portion joining portion (310) may be provided with at least one first welded portion (W) formed by welding with the first non-bonded portion (11). Specifically, at least one first welded portion (W) formed by welding with the first non-bonded portion (11) may be provided on the upper surface of the non-bonded portion joining portion (310). Preferably, referring to FIG. 6, the non-bonded portion joining portion (310) may be provided with a plurality of first welded portions (W) formed by welding with the first non-bonded portion (11).

[0099] In one embodiment of the present invention, the first weld (W) may be configured as a circle based on the winding center. For example, in the case where the first weld (W) is provided in multiple numbers, the first weld (W) may be configured as multiple concentric circles based on the winding center. However, the shape of the first weld (W) is not limited thereto, and any weld shape in which the first non-welded portion (11) and the current collector (30) can be combined is included within the scope of the present invention.

[0100] The first weld (W) may be a weld formed by laser welding. In this case, the laser welding may be performed on the upper surface of the non-reinforced joint (310). That is, laser through-welding may be performed on the upper surface of the non-reinforced joint (310).

[0101] According to the above configuration, large-area welding becomes possible compared to conventional ultrasonic welding (CRW). That is, a low-resistance battery cell (1) can be realized through a laser penetration welding (RFW) process. In addition, according to the above configuration, costs can be reduced in terms of the process due to process simplification. For example, according to the present invention, CCW and ISI processes can be omitted compared to the conventional method in the assembly process of a cylindrical battery cell (1).

[0102]

[0103] FIG. 7 is a drawing for explaining a current collector (30) according to another embodiment of the present invention.

[0104] In one aspect of the present invention, the non-reinforced portion joining portion (310) may be provided with at least one notch portion (N) for welding with a first non-reinforced portion (11). The notch portion (N) may be an area where the thickness of the non-reinforced portion joining portion (310) is relatively thin compared to other areas.

[0105] Referring to FIG. 7, the notch portion (N) may be provided in multiple numbers spaced apart at a predetermined interval along the radial direction. In the case where the notch portion (N) is provided in multiple numbers, the notch portion (N) may be composed of multiple concentric circles based on the winding center. At this time, laser welding may be performed on the outside of the battery cell (1) along the notch portion (N).

[0106] According to the above configuration, uniform welding can be performed on each battery cell (1). That is, according to the above configuration, since welding is performed along the notch (N), welding ease is improved, and a uniform amount of welding can be performed at a uniform location on each cell. In addition, large-area welding becomes possible compared to conventional CRW. That is, a low-resistance battery cell (1) can be realized through the RFW process.

[0107]

[0108] In another aspect of the present invention, an insulating gasket (40) interposed between the housing (20) and the current collector (30) may be provided on the side of the closing portion (22) of the housing (20). The insulating gasket (40) may be made of, for example, a resin material having insulating and elastic properties.

[0109] Referring to FIG. 5, the insulating gasket (40) may include a gasket exposure portion (41) and a gasket insertion portion (42).

[0110] The gasket exposure portion (41) is interposed between the rivet portion (33) and the housing (20). The gasket exposure portion (41) may be deformed together with the rivet portion (33) during riveting and exposed to the outside of the closed portion (22) of the housing (20). Specifically, the gasket exposure portion (41) may be in close contact with the outer surface of the closed portion (22) of the housing (20).

[0111] Preferably, the length of the gasket exposure portion (41) may be configured to be equal to or longer than the length of the rivet portion (33). For example, the gasket exposure portion (41) may be extended longer than the rivet portion (33), thereby being exposed to the outside of the rivet portion (33) when the cylindrical battery cell (1) is viewed from above. More specifically, the gasket exposure portion (41) may be extended longer than the second part (332) of the rivet portion (33). With such a structure, the insulating gasket (40) can reliably insulate the current collector (30) and the housing (20).

[0112] The gasket insertion portion (42) is interposed between the horizontal extension portion (31) of the current collector (30) and the housing (20). The gasket insertion portion (42) may be in close contact with the inner surface of the closure portion (22) of the housing (20). Preferably, the end of the gasket insertion portion (42) may be configured to be located radially further outward than the end of the horizontal extension portion (31) of the current collector (30). For example, the end of the gasket insertion portion (42) may be configured to extend to the side wall of the housing (20).

[0113] According to this configuration, the insulating gasket (40) can cover the entire inner surface of the closed portion (22) of the housing (20). Accordingly, the insulating gasket (40) can effectively prevent contact between the first uninsulated portion (11) of the electrode assembly (10) and the inner surface of the housing (20).

[0114] Accordingly, the top insulator, which was an essential component of conventional battery cells, can be omitted. That is, according to the above configuration, further reduction in the number of parts and cost reduction are possible. In addition, the total height of the electrode assembly (10) can be increased by removing the top insulator. Ultimately, according to the present invention, energy density can be further improved.

[0115]

[0116] FIG. 8 is a drawing for explaining the combined state of an electrode assembly (10) and a lower cap (50) according to one embodiment of the present invention.

[0117] Referring to FIG. 8, the electrode assembly (10) represents the electrode assembly (10) of FIG. 3 in an inverted state. That is, based on FIG. 8, the first non-removable portion (11) is located downward, and the second non-removable portion (12) is located upward. A lower cap (50) may be positioned on the second non-removable portion (12). The lower cap (50) is welded to the second non-removable portion (12). That is, the lower cap (50) may be attached to a joining surface formed by bending the end of the second non-removable portion (12) in a direction parallel to the lower cap (50). More specifically, the lower cap (50) may be attached to a joining surface formed by bending the segment (12a) of the second non-removable portion (12) in a direction parallel to the lower cap (50). At this time, the welding joint between the second non-welded portion (12) and the lower cap (50) can be performed on the outer surface of the lower cap (50). In this case, a second weld (51) is formed on the lower cap (50).

[0118] According to the above configuration, welding of the lower cap (50) and the second non-removable part (12) can be performed outside the battery cell (1). Accordingly, even if spatter is generated during welding, the spatter does not enter the interior of the battery cell (1). Accordingly, issues such as damage to the separator and reduction in battery capacity and lifespan caused by spatter during welding can be resolved. In addition, according to the present invention, since the welding is performed outside the battery cell (1), a welding horn tip is not required, so the diameter of the winding center hole of the electrode assembly (10) can be reduced, and thus energy density can be improved.

[0119] In addition, according to the above configuration, there is no need to include a separate negative electrode collector plate. That is, according to the above configuration, cost reduction can be achieved through the omission and / or deletion of parts. Furthermore, according to the above configuration, since there is no need to provide a separate negative electrode collector plate, the total height of the electrode assembly (10) can be increased. Accordingly, energy density can be further improved.

[0120]

[0121] In one aspect of the present invention, the lower cap (50) may be coupled to the opening (21) of the housing (20). That is, after the electrode assembly (10) is received into the housing (20) through the opening (21), the lower cap (50) may be seated on the opening (21) of the housing (20). Then, the housing (20) and the lower cap (50) may be joined by welding. In this case, seam welding may be performed along the edge of the opening (21).

[0122] In another aspect of the present invention, the lower cap (50) may have a central hole (50H) approximately in the center. The central hole (50H) may be composed of a roughly circular hole centered on the center of the lower cap (50). Electrolyte may be injected into the housing (20) through the central hole (50H). Once the injection of electrolyte is complete, a hole cover (53) configured to cover the central hole (50H) may be attached to the central hole (50H). For example, the hole cover (53) may be attached by press-fitting it onto the central hole (50H). Subsequently, the edge of the central hole (50H) and the edge of the hole cover (53) may be joined by welding.

[0123]

[0124] A manufacturing process of a battery cell (1) according to one embodiment of the present invention is described below.

[0125] First, as can be seen in FIG. 8, a lower cap (50) is placed on the surface where the second non-removable portion (12) is located among the two ends of the electrode assembly (10) wound in a jelly roll shape. Then, the lower cap (50) and the electrode assembly (10) are welded together on the upper surface of the lower cap (50). At this time, a second weld (51) is formed. After that, the combination of the electrode assembly (10) and the lower cap (50) shown in FIG. 8 is inserted through the opening (21) of the housing (20) in an upside-down state. At this time, the first non-removable portion (11) is located on the upper part of the electrode assembly (10). When the electrode assembly (10) is inserted to the inner surface of the closing portion (22) of the housing (20), the state shown in FIG. 5 is achieved. At this time, the non-removable portion connecting portion (310) of the current collector (30) is in contact with the first non-removable portion (11). After that, as shown in FIG. 6, the non-reinforced joint (310) and the first non-reinforced part (11) are joined by welding. Specifically, laser welding is performed on the upper surface of the current collector (30). At this time, the first weld (W) is formed. Again, after turning the battery cell (1) over, the lower cap (50) is joined to the housing (20) by performing seam welding along the edge of the opening (21) of the housing (20). Then, the electrolyte is injected through the central hole (50H) provided on the lower cap (50). Once the electrolyte injection is completed, a hole cover (53) configured to cover the central hole (50H) is press-fitted onto the central hole (50H), and then the contact area between the hole cover (53) and the central hole (50H) is welded together.

[0126] According to such a manufacturing process, process simplification can be achieved. Accordingly, costs can be reduced in terms of the process. For example, according to the present invention, CCW and ISI processes can be omitted compared to conventional methods in the cylindrical battery cell assembly process. Furthermore, according to the above configuration, large-area welding becomes possible compared to conventional CRW. That is, a low-resistance battery cell (1) can be realized through the RFW process.

[0127]

[0128] FIG. 9 is a drawing for illustrating a battery pack including a battery cell (1) according to one embodiment of the present invention.

[0129] Referring to FIG. 9, a battery pack (3) according to one embodiment of the present invention comprises a battery assembly in which a plurality of battery cells (1) according to one embodiment of the present invention as described above are electrically connected, and a pack housing (2) that accommodates the same. In the drawings of the present invention, components such as a busbar for electrical connection, a cooling unit, and a power terminal are omitted for convenience of drawing. In addition, the battery pack (3) may further include various components, such as a BMS, a pack case, a relay, a current sensor, etc., components of a battery pack (1) known at the time of filing the present invention.

[0130]

[0131] FIG. 10 is a drawing for explaining a vehicle including the battery pack (3) of FIG. 9.

[0132] Referring to FIG. 10, a vehicle (5) according to one embodiment of the present invention may be, for example, an electric vehicle, a hybrid vehicle, or a plug-in hybrid vehicle, and includes a battery pack (3) according to one embodiment of the present invention. The vehicle (5) includes four-wheeled vehicles and two-wheeled vehicles. The vehicle (5) operates by receiving power from the battery pack (3) according to one embodiment of the present invention. In addition, the vehicle (5) according to the present invention may further include various other components included in the vehicle in addition to the battery cell (1) or battery pack (3). For example, the vehicle (5) according to the present invention may further include, in addition to the battery cell (1) according to the present invention, a vehicle body, a motor, an ECU (electronic control unit), or a control device.

[0133]

[0134] Meanwhile, although terms indicating direction such as up and down have been used in this specification, these terms are used merely for convenience of explanation, and it is obvious to a person skilled in the art that they may vary depending on the location of the object or the position of the observer.

[0135] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs.

[0136]

[0137] [Explanation of the symbol]

[0138] 5: Cars

[0139] 3: Battery Pack

[0140] 2: Pack Housing

[0141] 1: Battery cell

[0142]

[0143] 10: Electrode assembly

[0144] 11: 1st Department of Indefinite Use

[0145] 11a: segment

[0146] 12: 2nd Department of Indefinite Use

[0147] H1: Winding center hole

[0148]

[0149] 20: Housing

[0150] 21: Open section

[0151] 22: Closure

[0152] 22H: Through hole

[0153]

[0154] 30: Whole house

[0155] 31: Horizontal extension

[0156] 310: Joint of the thumb

[0157] 32: Terminal section

[0158] 33: Rivet section

[0159] 331: Part 1

[0160] 332: Part 2

[0161] W: 1st weld

[0162] N: Notch

[0163]

[0164] 40: Insulation gasket

[0165] 41: Gasket exposure

[0166] 42: Gasket insertion part

[0167]

[0168] 50: Bottom cap

[0169] 50H: Central Hall

[0170] 51: Second weld

[0171] 53: Hole cover

Claims

1. An electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around a winding axis to define a core and an outer surface, wherein the first electrode comprises a first uncoated portion in which an active material layer is not coated along the winding direction; A housing comprising a closure portion having an opening on one side and configured to accommodate the electrode assembly through the opening, and having a through hole located on the opposite side of the opening and having at least a portion of the opening formed therein; and A current collector coupled to one end of the electrode assembly, having the same electrode as the first electrode, and configured to be exposed to the outside through the through hole. A battery cell containing 2. In Paragraph 1, The entire house mentioned above is, A horizontal extension portion disposed on the upper part of the electrode assembly and configured to face the first non-removable portion; A terminal portion located at the center of the horizontal extension portion and exposed to the outside of the housing; and A rivet portion that protrudes from the horizontal extension and is bent and extended to wrap around the housing. A battery cell characterized by including 3. In Paragraph 2, A battery cell characterized in that the above horizontal extension includes a non-reinforced portion coupling portion configured to be coupled with the first non-reinforced portion.

4. In Paragraph 3, The above-mentioned non-removable joint part is, A battery cell characterized by being provided in a region of the horizontal extension portion located radially inward from the rivet portion.

5. In Paragraph 1, A battery cell characterized in that the first non-removable portion and the current collector are configured to be welded together on the outside of the battery cell.

6. In Paragraph 2, A battery cell characterized in that the above-mentioned rivet portion is inserted into the through hole of the above-mentioned housing.

7. In Paragraph 2, The above rivet part is, A first part extending vertically from the horizontal extension towards the outside of the battery cell from the horizontal extension; and A second part bent from the end of the first part and extended parallel to the closure. A battery cell characterized by including 8. In Paragraph 3, A battery cell characterized by having at least one first welded portion formed by welding a first welded portion on the upper surface of the above-mentioned non-welded portion.

9. In Paragraph 8, A battery cell characterized by the first weld being configured in a circular shape based on the winding center.

10. In Paragraph 2, A battery cell characterized by having an insulating gasket interposed between the housing and the current collector on the closed side of the housing.

11. In Paragraph 10, The above insulating gasket is, A gasket exposure portion interposed between the above-mentioned rivet portion and the housing; and A gasket insert interposed between the horizontal extension of the above-mentioned house and the housing. A battery cell characterized by including 12. In Paragraph 11, A battery cell characterized in that the length of the gasket exposure portion is configured to be equal to or longer than the length of the rivet portion.

13. In Paragraph 12, A battery cell characterized in that the end of the gasket insertion portion is located radially further outward than the end of the horizontal extension portion of the current collector.

14. A battery pack characterized by comprising at least one battery cell described in any one of claims 1 to 13.

15. An automobile characterized by comprising at least one battery pack as described in claim 14.

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