Electrode assembly and battery cell, battery pack, and vehicle including same

Abstract

An electrode assembly according to an embodiment of the present invention is an electrode assembly in which a first electrode, a second electrode, and a separator therebetween are wound around an axis to define a core and an outer circumferential surface, wherein at least one of the first electrode and the second electrode includes, at the long side end thereof, an uncoated portion that is not coated with an active material in a winding direction, the uncoated portion includes a core-side uncoated portion and an outer circumferential uncoated portion, and the core-side uncoated portion and the outer circumferential uncoated portion are bent in opposite directions.

Description

Electrode assembly and battery cell, battery pack and automobile including the same

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

[0002] This application is a priority application for Korean Patent Application No. 10-2025-0035907 filed on March 20, 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, conventional cylindrical battery cells feature a foil tab structure in which the unmarked portion is notched to form a tab. In this process, the foil is notched to create the tab, which is then welded to the current collector plate. However, in such conventional cylindrical cells, pressure caused by the expansion and contraction of the electrodes during repeated charging and discharging is applied to the core, resulting in a phenomenon called Core Collapse, where the concentric circles of the electrode assembly become crumpled or disrupted. Consequently, in conventional battery cells, the occurrence of Core Collapse may lead to damage to the separator and cracking of the electrodes, potentially causing an internal short circuit in the battery.

[0006] Accordingly, the present invention has one objective of preventing core collapse by preventing the slippage of the electrode near the core of the electrode assembly.

[0007] In addition, the present invention has another purpose of reducing the internal resistance of the battery.

[0008] In another aspect, the present invention has another objective of reducing the manufacturing cost of the electrode.

[0009] 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.

[0010] An electrode assembly according to an embodiment of the present invention for solving the above-mentioned problem is an electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around an axis to define a core and an outer surface, wherein at least one of the first electrode and the second electrode includes an uncoated portion at the end of the long side in the winding direction in which an active material is not coated, and the uncoated portion includes a core-side uncoated portion and an outer-side uncoated portion, and the core-side uncoated portion and the outer-side uncoated portion are folded in opposite directions.

[0011] In one aspect of the present invention, the core-side unoccupied portion and the outer-side unoccupied portion may be bent in the radial direction of the electrode assembly.

[0012] Preferably, the core-side unworn portion is bent toward the outer circumference, and the outer circumference-side unworn portion can be bent toward the core.

[0013] In another aspect of the present invention, the unworn portion may include a plurality of segments that can be folded independently of each other.

[0014] Preferably, the segment included in the core-side region, which is the area where the core-side unwound portion is wound, can be folded toward the outer circumference.

[0015] Preferably, the segment included in the outer side area, which is the area where the outer side unwound portion is wound, can be folded toward the core.

[0016] In one aspect of the present invention, the width of the core side region may be set such that the radial width of the coil turns formed by the core side region is greater than or equal to the height of the segment.

[0017] In another aspect of the present invention, the number of segments included in the core side region may be configured to be fewer than the number of segments included in the outer side region.

[0018] Preferably, the segments included in the core-side region may be arranged to be spaced apart at equal intervals along the circumferential direction.

[0019] For example, the segments included in the core side region may be arranged at intervals of 90 degrees or 180 degrees along the circumferential direction.

[0020] In one aspect of the present invention, the segment provided in the core side region may be configured to overlap with the segment provided in the outer circumference side region.

[0021] In another aspect of the present invention, the height of the segment provided in the core side region may be configured to be greater than the height of the segment provided in the outer side region.

[0022] Meanwhile, the present invention provides a battery cell comprising at least one electrode assembly according to the above-described embodiment as a battery cell.

[0023] Meanwhile, the present invention provides a battery pack comprising at least one battery cell according to the above-described embodiment as a battery pack.

[0024] In addition, the present invention provides a vehicle comprising at least one battery pack according to the above-described embodiment.

[0025] According to the present invention, by preventing the slippage of the electrode near the core of the electrode assembly, the core collapse phenomenon can be prevented.

[0026] In addition, according to the present invention, it is possible to implement a low-resistance battery cell by reducing the internal resistance of the battery.

[0027] In another aspect, according to the present invention, the manufacturing cost of the electrode can be effectively reduced.

[0028] 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.

[0029] 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.

[0030] FIG. 1 is a plan view showing the structure of an electrode according to an embodiment of the present invention.

[0031] FIG. 2 is a perspective view showing an electrode assembly according to an embodiment of the present invention.

[0032] Figure 3 is a drawing showing the state in which the segments of a conventional electrode assembly are bent from the outer circumference to the core side.

[0033] Figure 4 is a diagram illustrating the phenomenon of the winding center being crumpled in a conventional electrode assembly.

[0034] FIG. 5 is a drawing for explaining the structure of an electrode assembly according to one embodiment of the present invention.

[0035] FIG. 6 is a drawing for explaining the structure of an electrode assembly according to another embodiment of the present invention.

[0036] FIG. 7 is a drawing for explaining the structure of an electrode assembly according to another embodiment of the present invention.

[0037] FIG. 8 is a drawing for explaining the structure of an electrode assembly according to another embodiment of the present invention.

[0038] FIG. 9 is a drawing for illustrating a battery cell including an electrode assembly according to one embodiment of the present invention.

[0039] FIG. 10 is a schematic diagram showing the configuration of a battery pack according to an embodiment of the present invention.

[0040] FIG. 11 is a drawing for explaining a vehicle including the battery pack of FIG. 10.

[0041] 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.

[0042] 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.

[0043] 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.

[0044] 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.

[0045] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] 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.

[0050]

[0051] FIG. 1 is a plan view showing the structure of an electrode (40) according to an embodiment of the present invention, and FIG. 2 is a perspective view showing an electrode assembly (80) according to an embodiment of the present invention.

[0052] An electrode assembly (80) according to one embodiment of the present invention is a jellyroll type electrode assembly (80) having a structure in which a first electrode (40) having a sheet shape, a second electrode, and a separator interposed between them are wound around an axis. The electrode assembly (80) has a core (C) and an outer surface defined by the first electrode (40), the second electrode, and the separator interposed between them being wound around an axis. However, since the present invention is not limited by a specific type of electrode assembly (80), the electrode assembly (80) may be provided with any winding structure well known in the art.

[0053] For convenience of explanation, the following description is limited to the first electrode (40), but the details regarding the first electrode (40) described later can be applied equally to the second electrode.

[0054] Referring to FIG. 1, the first electrode (40) includes a non-coated portion (43) at the long end of the winding direction in which the active material is not coated. At least a portion of the non-coated portion (43) is used as itself as an electrode (40) tab. At this time, the non-coated portion (43) is exposed to the outside of the separator along the winding axis direction of the electrode assembly (80).

[0055] Referring to FIG. 1, the electrode (40) comprises an electrode plate (41) made of a metal foil and an active material layer (42). The metal foil may be aluminum or copper and is appropriately selected according to the polarity of the electrode (40). The active material layer (42) is formed on at least one surface of the electrode plate (41) and includes an uncoated portion (43) at the long end of the winding direction. The uncoated portion (43) is an area where the active material is not coated. Specifically, the first electrode (40) may comprise a first electrode plate (41) and an active material layer (42) formed on at least one surface thereof. Preferably, the first electrode plate (41) may comprise aluminum.

[0056] Meanwhile, the second electrode may include a second electrode plate and an active material layer formed on at least one surface thereof. In this case, the second electrode plate may include copper.

[0057]

[0058] Referring to FIG. 1, the portion that is folded in the unbound portion (43) of the electrode (40) may include a plurality of segments (61). The segments (61) may be divided so that they can be folded independently of each other. That is, the unbound portion (43) of the first electrode (40) or the second electrode may be divided into a plurality of segments (61) that can be folded independently of each other. In one aspect of the present invention, the segments (61) may be notched with a laser. The segments (61) may be formed by a known metal foil cutting process, such as ultrasonic cutting or stamping.

[0059] When the electrode (40) is wound, a plurality of segments (61) may be bent radially along the bending line of the electrode assembly (80). The segments (61) may be bent, for example, toward the core (C) or toward the outer circumference. The core (C) refers to a cavity located at the center of the winding of the electrode assembly (80).

[0060] Multiple segments (61) have the shape of a geometric figure with a bending line as the base. In the geometric figure, the width of the lower part may be greater than the width of the upper part. Also, in the geometric figure, the width of the lower part may increase gradually or stepwise (not shown) as it goes upward. Preferably, the geometric figure may have a trapezoidal shape. Alternatively, the geometric figure may have a shape formed by connecting at least one straight line, at least one curve, or a combination thereof. In one example, the geometric figure may be a polygon such as a triangle, a square, or a parallelogram. In another example, the geometric figure may have an arc shape such as a semicircle or a semi-ellipse.

[0061] When the unworn portion (43) is bent in the radial direction, a bent surface area (F) is formed on the upper and lower parts of the electrode assembly (80), as shown in FIG. 2. That is, referring to FIG. 2, a plurality of segments (61) are bent toward the core (C) side or the outer circumference side of the electrode assembly (80) and overlapped in multiple layers along the radial direction.

[0062]

[0063] Referring to FIG. 1, the unoccupied portion (43) may include a core-side unoccupied portion (B1) adjacent to the core (C) side of the electrode assembly (80) and an outer-side unoccupied portion (B2) adjacent to the outer-side of the electrode assembly (80).

[0064] The core-side unwound portion (B1) can be defined as the unwound portion (43) of the area adjacent to the core (C) side when the electrode (40) is wound into a jelly roll type electrode assembly (80). Specifically, the core-side unwound portion (B1) may correspond to the unwound portion (43) of the electrode (40) area including the innermost winding turn.

[0065] Meanwhile, the outer side unwound portion (B2) can be defined as the unwound portion (43) of the area adjacent to the outer side when the electrode (40) is wound into a jelly roll type electrode assembly (80). Specifically, the outer side unwound portion (B2) may correspond to the unwound portion (43) of the electrode (40) area including the outermost winding turn.

[0066] The number of turns can be counted based on the core (C) side end of the electrode assembly (80). In one example, the boundary of B1 / B2 can be appropriately defined at a point of a predetermined % based on the radius of the electrode assembly (80) (e.g., a point of 5%, 10%, 15% of the radius, etc.).

[0067]

[0068] In one aspect of the present invention, the core-side unworn portion (B1) and the outer-side unworn portion (B2) may be bent in opposite directions. Specifically, the core-side unworn portion (B1) and the outer-side unworn portion (B2) may be bent in the radial direction of the electrode assembly (80). At this time, referring to FIG. 2, the core-side unworn portion (B1) may be bent toward the outer side. Meanwhile, the outer-side unworn portion (B2) may be bent toward the core (C). Preferably, the core-side unworn portion (B1) may be fixed at a position adjacent to the core (C) so that the electrode (40) cannot move due to pressure.

[0069] According to this structure, the core-side unsold portion (B1) is bent toward the outer circumference and comes into direct contact with a plurality of unsold portions (43) that form a concentric circle of the electrode assembly (80). Accordingly, the core-side unsold portion (B1) can be joined to the plurality of unsold portions (43) that form a concentric circle of the electrode assembly (80) by welding. That is, the core-side unsold portion (B1) can be configured to fix the concentric circle of the core-side region in a certain shape. That is, the core-side unsold portion (B1) can be configured to prevent slippage of the electrode (40) that forms the electrode assembly (80). Therefore, according to the above configuration, the rigidity of the core (C) side of the electrode assembly (80) can be increased, and at the same time, the core collapse phenomenon can be prevented. Accordingly, according to the present invention, the safety of the battery cell (301) can be improved by preventing cracks in the electrode (40) and perforation of the separator.

[0070]

[0071] FIG. 3 is a drawing showing the state in which the segments (61) of a conventional electrode assembly (80) are bent from the outer side toward the core (C), and FIG. 4 is a drawing explaining the phenomenon of the winding center being crumpled in a conventional electrode assembly (80).

[0072] In a conventional electrode assembly (80) as shown in Fig. 3, the segment (61) is included only in the outer circumference side unoccupied portion (B2). That is, in a conventional electrode assembly (80), the segment (61) is not included in the core side unoccupied portion (B1).

[0073] Meanwhile, the phenomenon in which the center of the winding in the electrode assembly (80) is crumpled is called Core Collapse. Specifically, referring to FIG. 4, the pressure caused by the expansion of the electrode (40) during charging and discharging of the cylindrical cell returns to the core (C), causing the concentric circles of the electrode assembly (80) to be crumpled or disrupted. Accordingly, in conventional battery cells, when Core Collapse occurs, there is a possibility that damage to the separator by the electrode (40) and cracking of the electrode (40) may occur, thereby causing an internal short circuit of the battery.

[0074]

[0075] FIG. 5 is a drawing for explaining the structure of an electrode assembly (80) according to one embodiment of the present invention.

[0076] In an electrode assembly (80) according to one embodiment of the present invention, a plurality of segments (61) may form a plurality of segments (61) group as they extend from the core (C) side to the outer circumference side. For example, referring to FIG. 5, the first electrode (40) constituting the electrode assembly (80) may be divided into two regions. More specifically, the first electrode (40) may be divided into a core side region (A1) and an outer circumference side region (A2).

[0077] Referring to FIGS. 1 and FIGS. 5, the core side region (A1) can be defined as the region where the core side unwound portion (B1) is wound. The segment (61) included in the core side region (A1), which is the region where the core side unwound portion (B1) is wound, can be folded toward the outer circumference.

[0078] Meanwhile, the outer side area (A2) can be defined as the area where the outer side unwound portion (B2) is wound. The segment (61) included in the outer side area (A2), which is the area where the main side unwound portion (B2) is wound, can be folded toward the core.

[0079] In one aspect of the present invention, the width of the core side region (A1) can be designed by applying a condition that does not obscure the core (C) of the electrode assembly (80) when the segments (61) of the outer side region (A2) are bent toward the core (C).

[0080] In one example, referring to FIG. 5, the width of the core side area (A1) can be increased in proportion to the bending length of the segment (61). The bending length corresponds to the height (H) of the segment (61) based on the bending point.

[0081] Preferably, the width of the core side region (A1) can be set so that the radial width of the coils formed by the core side region (A1) is greater than or equal to the height (H) of the segment (61). In a variation, the width of the core side region (A1) can be configured so that the value obtained by subtracting the radial width of the coils formed by the core side region (A1) from the height (H) of the segment (61) is less than or equal to 0.

[0082]

[0083] In one aspect of the present invention, the core-side unoccupied portion (B1) may include at least one segment (61). Preferably, the core-side unoccupied portion (B1) may include a plurality of segments (61). In another aspect of the present invention, the outer-side unoccupied portion (B2) may include at least one segment (61). Preferably, the outer-side unoccupied portion (B2) may include a plurality of segments (61).

[0084] According to the above configuration, the manufacturing cost can be reduced compared to a conventional battery cell (301). Specifically, in a conventional battery cell (301), the core-side unoccupied portion (B1) is not provided with a segment (61), so the core-side unoccupied portion (B1) is manufactured by straight notching. Consequently, the area of ​​the electrode plate (40) that is removed increases, which caused the problem of the cell manufacturing cost to rise. However, according to the present invention, since at least one segment (61) is included in the core-side unoccupied portion (B1), the area of ​​the electrode plate (40) that is removed from the core-side unoccupied portion (B1) is reduced. That is, the present invention can reduce unnecessary removal of the Al or Cu foil constituting the electrode plate (40). Therefore, according to the present invention, the manufacturing cost of the battery cell (301) can be effectively reduced.

[0085]

[0086] In another aspect of the present invention, the bent segment (61) may be fixed by welding. For example, when the segment (61) provided on the outer circumference side unoccupied portion (B2) is bent toward the core (C), a bent surface area (F) may be formed on the upper and / or lower part of the electrode assembly (80). At this time, a plurality of segments (61) forming the bent surface area (F) may be joined together by welding.

[0087] In another aspect, when the segment (61) provided in the core-side unwound portion (B1) is bent toward the outer circumference, the segment (61) provided in the core-side unwound portion (B1) can be joined by welding to the wound unwound portion (43) located in the core-side region (A1). That is, the segment (61) provided in the core-side unwound portion (B1) can be welded and fixed at a position adjacent to the core (C) so that the electrode (40) cannot move due to pressure. In this case, the segment (61) provided in the core-side unwound portion (B1) can form a bent surface region (F).

[0088] More preferably, a current collector configured to be electrically connected to the electrode assembly (80) may be provided on the upper and / or lower surface of the electrode assembly (80). For example, a first current collector may be placed on the bent surface area (F) formed by the segment (61) of the first electrode (40). In this case, the bent surface area (F) and the first current collector may be joined together by welding. In another aspect, a second current collector may be placed on the bent surface area (F) formed by the segment (61) of the second electrode. In this case, the bent surface area (F) and the second current collector may be joined together by welding.

[0089]

[0090] In another aspect of the present invention, the number of segments (61) included in the core side region (A1) may be configured to be fewer than the number of segments (61) included in the outer side region (A2).

[0091] For example, referring to FIG. 5, the electrode assembly (80) includes two segments (61) in the core side region (A1). In this case, the segments (61) included in the core side region (A1) may be configured to face each other. That is, the segments included in the core side region (A1) may be arranged to be spaced apart at equal intervals along the circumferential direction. In this case, the segments (61) included in the core side region (A1) may be arranged at intervals of approximately 180 degrees along the circumferential direction.

[0092] Meanwhile, the electrode assembly (80) includes a plurality of segments (61) in the outer circumference area (A2). Specifically, the electrode assembly (80) includes two or more segments (61) in the outer circumference area (A2). In other words, referring to FIG. 1, the number of segments (61) included in the core side unoccupied portion (B1) may be configured to be fewer than the number of segments (61) included in the outer circumference side unoccupied portion (B2).

[0093] According to this configuration, the structure is such that welding between the current collector and the cell terminal (110) is easy through the empty space of the core (C) of the electrode assembly (80). Specifically, referring to FIG. 5, when the distance from the center of the electrode assembly (80) to a point not covered by the segment (61) included in the outer circumference area (A2) is called the first radius (R1) and the radius of the electrode assembly (80) is called the second radius (R2), welding between the current collector and the cell terminal (110) can be easily performed by securing an area not covered by the segment (61) included in the outer circumference area (A2). That is, by configuring the number of segments (61) in the core side area (A1) of the electrode assembly (80) to be less than the number of segments (61) in the outer circumference area (A2), welding between the current collector and the cell terminal (110) can be easily performed. At the same time, the core collapse phenomenon of the electrode assembly (80) can be effectively prevented by at least one segment (61) provided in the core side region (A1).

[0094] Furthermore, according to the above configuration, the area of ​​the folded surface region (F) increases compared to the conventional electrode assembly (80). That is, in the conventional electrode assembly (80) as shown in FIG. 3, the segmented section (61) is not provided in the core side region (A1), so the folded surface region (F) is not formed in the core side region (A1). On the other hand, according to the electrode assembly (80) of the present invention as shown in FIG. 5, the segmented section (61) is included in the core side region (A1), so the folded surface region (F) is formed in the core side region (A1) as well. Therefore, the total area of ​​the folded surface region (F) of the electrode assembly (80) becomes larger than the area of ​​the folded surface region (F) of the conventional electrode assembly (80). Accordingly, the current passage area becomes larger, and thus the internal resistance of the battery is lowered. Therefore, according to the present invention, a low-resistance battery cell (301) can be realized.

[0095]

[0096] In another aspect of the present invention, a segment (61) provided in the core side region (A1) may be configured to overlap with a segment (61) provided in the outer side region (A2).

[0097] For example, referring to FIG. 5, the segment (61) provided in the core side region (A1) may be configured to overlap with the segment (61) located at the innermost coil turn of the outer side region (A2). More specifically, the height (H) of the segment (61) provided in the core side region (A1) may be configured to be greater than or equal to the value obtained by subtracting the height (H) of the segment (61) provided in the outer side region (A2) from the radial length of the core side region (A1).

[0098] According to this configuration, the rigidity of the core (C) side of the electrode assembly (80) can be increased, and at the same time, the core collapse phenomenon can be prevented. In addition, according to the above configuration, the rigidity of the entire area along the radius of the electrode assembly (80), not just the core (C) side of the electrode assembly (80), can be increased.

[0099]

[0100] FIG. 6 is a drawing for explaining the structure of an electrode assembly (80) according to another embodiment of the present invention.

[0101] Since the electrode assembly (80) according to the present embodiment is similar to the electrode assembly (80) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0102] In one embodiment of the present invention, the segment (61) provided in the core side region (A1) may overlap with the segment (61) provided in the outer side region (A2). For example, as shown in FIG. 5 or FIG. 6, the segment (61) located in the outer side region (A2) may be bent toward the core (C), and the segment (61) located in the core side region (A1) may be bent toward the outer side. Conversely, the segment (61) located in the core side region (A1) may be bent toward the outer side, and the segment (61) located in the outer side region (A2) may be bent toward the core (C).

[0103] Meanwhile, as shown in FIG. 6, the height (H) of the segment (61) provided in the core side region (A1) may be configured to be greater than the height (H) of the segment (61) provided in the outer side region (A2). For example, the height (H) of the segment (61) provided in the core side region (A1) may be configured to be greater than or equal to the value obtained by subtracting the height (H) of the segment (61) located in the outer side region (A2) from the distance from the point where the innermost winding turn of the electrode assembly (80) is located to the point where the outermost winding turn of the electrode assembly (80) is located. In this case, the segment (61) provided in the core side region (A1) may overlap with the segment (61) located in the outermost winding turn.

[0104] According to this configuration, the rigidity of the core (C) side of the electrode assembly (80) can be increased, and at the same time, the core collapse phenomenon can be prevented. In addition, according to the above configuration, the rigidity of the entire area along the radius of the electrode assembly (80), not just the core (C) side of the electrode assembly (80), can be increased.

[0105]

[0106] FIG. 7 is a drawing for explaining the structure of an electrode assembly (80) according to another embodiment of the present invention.

[0107] Since the electrode assembly (80) according to the present embodiment is similar to the electrode assembly (80) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0108] In another embodiment of the present invention, referring to FIG. 7, the core-side unoccupied portion (B1) may include a plurality of segments (61). In this case, the plurality of segments (61) may be arranged to be spaced apart at equal intervals along the circumferential direction. For example, as shown in FIG. 7, the core-side region (A1) may include four segments (61). In this case, the four segments (61) may be configured to be spaced apart from each other at intervals of approximately 90 degrees along the circumferential direction.

[0109] According to the above configuration, slipping of the electrode (40) constituting the electrode assembly (80) can be effectively prevented by the plurality of segments (61) provided in the core side region (A1). Accordingly, according to the above configuration, the rigidity of the core (C) side of the electrode assembly (80) can be increased, and at the same time, the core collapse phenomenon can be prevented.

[0110] In addition, according to the above configuration, the manufacturing cost can be reduced compared to a conventional battery cell (301). Specifically, according to the present invention, since a plurality of segments (61) are included in the core-side unoccupied portion (B1), the area of ​​the electrode plate (40) removed from the core-side unoccupied portion (B1) is reduced. That is, in the present invention, unnecessary removal of the Al or Cu foil constituting the electrode plate (40) can be reduced. Therefore, according to the present invention, the manufacturing cost of the battery cell (301) can be effectively reduced.

[0111] Meanwhile, although the present invention has been described as being limited to an embodiment in which four segments (61) are included in the core side region (A1), it is obvious that the number of segments (61) included in the core side region (A1) is not limited to this embodiment.

[0112]

[0113] FIG. 8 is a drawing for explaining the structure of an electrode assembly (80) according to another embodiment of the present invention.

[0114] Since the electrode assembly (80) according to the present embodiment is similar to the electrode assembly (80) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0115] In another embodiment of the present invention, referring to FIG. 8, some of the segments (61) included in the core side region (A1) may be provided at a point spaced apart by a predetermined distance (D) from the innermost winding turn of the core side region (A1). That is, the segments (61) included in the core side region (A1) do not necessarily have to be located at the innermost winding turn.

[0116] According to this configuration, by appropriately positioning the segment (61), the deformation of the electrode (40) that may occur due to the bending of the segment (61) located in the core side area (A1) can be effectively prevented.

[0117]

[0118] Meanwhile, it goes without saying that the characteristic structure of the present invention described above can be applied equally to the first electrode (40) as well as the second electrode. That is, the electrode (40) plate structure of the above-described embodiments (variants) can be applied to the first electrode (40) and / or the second electrode having different polarities included in the jellyroll type electrode assembly (80). Furthermore, if the electrode (40) structure of the embodiments (variants) is applied to either the first electrode (40) or the second electrode, the conventional electrode (40) plate structure can be applied to the other. Additionally, the electrode (40) plate structures applied to the first electrode (40) and the second electrode may not be identical to each other and may be different.

[0119] The electrode assembly (80) according to an embodiment of the present invention is a jellyroll type electrode assembly (80) in which the electrode (40) of the embodiment is applied to the first electrode (40) and the second electrode. However, the present invention is not limited by the specific type of the electrode assembly (80).

[0120]

[0121] Hereinafter, a battery cell (301) according to an embodiment of the present invention included in a battery pack (300) will be described in detail.

[0122] FIG. 9 is a drawing for explaining a battery cell (301) including an electrode assembly (80) according to one embodiment of the present invention.

[0123] A battery cell (301) according to one embodiment of the present invention comprises an electrode assembly (80) including a first electrode (40), a separator, and a second electrode, a battery housing (90) that houses the electrode assembly (80), a housing cover (100) that seals an open end of the battery housing (90), and a cell terminal (110) provided on the opposite side of the open end of the battery housing (90).

[0124] Preferably, the unseen portion (43) of the electrode assembly (80) is divided into a plurality of segments (61), and the folded surface area (F) is formed by the plurality of segments (61) being folded radially.

[0125] The battery housing (90) is a cylindrical container with an opening formed at the top. The battery housing (90) is made of a conductive metal material such as aluminum or steel. The battery housing (90) accommodates an electrode assembly (80) in the inner space through the top opening and also accommodates an electrolyte.

[0126] Meanwhile, the battery cell (301) may further include a first current collector and / or a second current collector.

[0127] The first current collector has a plate shape and is coupled to the upper part of the electrode assembly (80). The first current collector is made of a conductive metal material such as aluminum, copper, nickel, etc. and is electrically connected to a bent surface area (F) formed by bending the uncoated portion (43) of the first electrode (40). Preferably, the current collector can be welded to the bent surface area (F).

[0128] The connection between the bent surface area (F) of the non-removable portion (43) and the first current collector can be achieved, for example, by laser welding. Laser welding can be performed by partially melting the current collector base material. Laser welding can be replaced by resistance welding, ultrasonic welding, etc.

[0129]

[0130] FIG. 10 is a schematic diagram showing the configuration of a battery pack (300) according to an embodiment of the present invention.

[0131] A battery cell (301) according to the above-described embodiments (variants) can be used to manufacture a battery pack (300).

[0132] Referring to FIG. 10, a battery pack (300) according to an embodiment of the present invention includes an assembly in which battery cells (301) are electrically connected and a pack housing (302) that accommodates the same. The battery cells (301) may be any one of the batteries according to the embodiments (variations) described above. In the drawings, for convenience of drawing, components such as busbars, cooling units, and external terminals for electrically connecting the battery cells (301) are omitted. Additionally, the battery pack (300) may further include various components, such as components of a battery pack (1) known at the time of filing the present invention, such as a BMS, a pack case, a relay, a current sensor, etc.

[0133]

[0134] FIG. 11 is a drawing for explaining a vehicle (V) including the battery pack (300) of FIG. 10.

[0135] Referring to FIG. 11, a vehicle (V) 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 (300) according to one embodiment of the present invention. The vehicle (V) includes four-wheeled vehicles and two-wheeled vehicles. The vehicle (V) operates by receiving power from the battery pack (300) according to one embodiment of the present invention. In addition, the vehicle (V) according to the present invention may further include various other components included in the vehicle in addition to the battery cell (301) or battery pack (300). For example, the vehicle (V) according to the present invention may further include a vehicle body, a motor, a control device such as an ECU (electronic control unit), in addition to the battery cell (301) according to the present invention.

[0136]

[0137] 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.

[0138] 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.

[0139]

[0140] [Explanation of the symbol]

[0141] 40 electrodes

[0142] 41 First electrode plate

[0143] 42 active material layer

[0144] 43 Uninformed

[0145] 61 segments

[0146] C core

[0147] F bending surface area

[0148] 80 electrode assemblies

[0149] B1 core side non-restricted area

[0150] B2 Outsourcing Side Unauthorized Department

[0151] A1 core side area

[0152] A2 Outsourcing Area

[0153] H height of the segment

[0154] 90 battery housing

[0155] 100 housing cover

[0156] 110 cell terminal

[0157] 300 battery pack

[0158] 301 battery cell

[0159] 302 Pack Housing

[0160] V Car

Claims

1. An electrode assembly in which a first electrode and a second electrode and a separator interposed between them are wound around an axis to define a core and an outer surface, At least one of the first electrode and the second electrode comprises an uncoated portion at the long end of the winding direction in which the active material is not coated, and The above-mentioned blank portion includes a core-side blank portion and an outer-side blank portion, and An electrode assembly characterized in that the core-side unworn portion and the outer-side unworn portion are bent in opposite directions.

2. In Paragraph 1, An electrode assembly characterized in that the core-side blank portion and the outer-side blank portion are bent in the radial direction of the electrode assembly.

3. In Paragraph 1, An electrode assembly characterized in that the core-side non-removable portion is bent toward the outer circumference, and the outer circumference-side non-removable portion is bent toward the core.

4. In Paragraph 1, The above-mentioned non-removable portion comprises a plurality of segments that can be folded independently of each other, characterized as an electrode assembly.

5. In Paragraph 4, An electrode assembly characterized in that the segment included in the core side region, which is the region where the core side unwound portion is wound, is bent toward the outer circumference.

6. In Paragraph 5, An electrode assembly characterized in that the segment included in the outer side region, which is the region where the outer side unwound portion is wound, is bent toward the core side.

7. In Paragraph 5, The width of the core-side region mentioned above is, An electrode assembly characterized in that the radial width of the coil turns formed by the core side region is set to be greater than or equal to the height of the segment.

8. In Paragraph 6, The number of segments included in the core-side region above is, An electrode assembly characterized by being composed of fewer segments than the number of segments included in the outer circumference area above.

9. In Paragraph 6, An electrode assembly characterized in that the segments included in the core side region are arranged to be spaced apart at equal intervals along the circumferential direction.

10. In Paragraph 6, An electrode assembly characterized in that the segments included in the core side region are arranged at intervals of 90 degrees or 180 degrees along the circumferential direction.

11. In Paragraph 6, An electrode assembly characterized in that the segment provided in the core side region is configured to overlap with the segment provided in the outer side region.

12. In Paragraph 6, An electrode assembly characterized in that the height of the segment provided in the core side region is configured to be greater than the height of the segment provided in the outer side region.

13. A battery cell characterized by comprising an electrode assembly described in any one of claims 1 to 12.

14. A battery pack characterized by including at least one battery cell as described in claim 13.

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

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