Electrode assembly

Abstract

An electrode assembly according to an embodiment of the present invention comprises, on at least one of the side surfaces of the electrode assembly, a region in which the end of at least some separators among a plurality of stacked separators is bent, and an adhesive-coated region in which the bent separators are coated with an adhesive, wherein the adhesive in the adhesive-coated region may be obliquely applied at an incline with respect to the height direction of the electrode assembly.

Description

electrode assembly

[0001] Cross-citation with related application(s)

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0023674 dated February 24, 2025, and all contents disclosed in the document of said Korean patent application are incorporated herein as part of this specification.

[0003] The present invention relates to an electrode assembly, and more specifically, to an electrode assembly in which a separator is fixed with an adhesive without affecting the performance of the electrode.

[0004] In modern society, as the use of portable devices such as mobile phones, laptops, camcorders, and digital cameras, as well as energy storage systems (ESS), has become commonplace, the development of technologies in related fields is becoming active. Furthermore, rechargeable secondary batteries are being utilized as power sources for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (P-HEVs) as a solution to address air pollution caused by conventional gasoline vehicles using fossil fuels; consequently, the need for the development of secondary batteries is increasing.

[0005] Currently commercialized rechargeable batteries include nickel-cadmium, nickel-hydrogen, nickel-zinc, and lithium-ion batteries. Among these, lithium-ion batteries are receiving the most attention due to their advantages of free charging and discharging, low self-discharge rate, and high energy density.

[0006] These lithium secondary batteries primarily use lithium-based oxides and carbon materials as the positive and negative active materials, respectively. The lithium secondary battery comprises an electrode assembly in which a positive plate and a negative plate, each coated with the positive and negative active materials, are arranged with a separator in between, and an outer casing, namely a battery case, that seals and houses the electrode assembly together with an electrolyte.

[0007] These battery cells are manufactured in a form where the electrode assembly is contained within a battery case along with the electrolyte.

[0008] FIG. 1 schematically illustrates a method of bonding a separator of an electrode assembly (1) according to conventional technology.

[0009] To fix the electrode assembly (1), a sealing unit (2) is included to fuse the stacked separators of the electrode assembly (1). The sealing unit (2) is positioned on the side of the electrode assembly (1) and heats and fuses the stacked separators. One side of the sealing unit (2) includes a heating portion (2a), and the heating portion (2a) of the sealing unit (2) is positioned on the side of the electrode assembly (1) to heat the separators on the side of the electrode assembly (1) so that fusion is achieved between the stacked separators. The portion where fusion is achieved between the stacked separators of the electrode assembly (1) becomes the sealing portion (S), and the electrode assembly (1) is fixed by the sealing portion (S).

[0010] Meanwhile, depending on the type of separator, etc., even if heated with the sealing unit (2), fusion between the stacked separators may not occur or fusion may be incomplete.

[0011] To solve this problem, according to other conventional technologies, there is a method of fixing the electrode assembly (1) by applying an adhesive to the side of the electrode assembly (1). However, according to this conventional technology, there is a concern that the adhesive applied to the side of the electrode assembly (1) may penetrate between the separators and have an undesirable effect on the performance of the electrode. A solution is needed to solve this problem.

[0012] The present invention aims to provide an electrode assembly in which a separator is fixed with an adhesive without affecting the performance of the electrode.

[0013] However, the problems that the embodiments of the present invention aim to solve are not limited to the problems described above and can be expanded in various ways within the scope of the technical ideas included in the present invention.

[0014] An electrode assembly according to one embodiment of the present invention includes, on at least one side surface of the electrode assembly, an area in which the end of at least some of the separators among a plurality of stacked separators is bent, and an adhesive application area in which an adhesive is applied over the bent separator, wherein the adhesive application area may be applied diagonally at an angle with respect to the height direction of the electrode assembly.

[0015] At least some of the ends of the separators among the above-mentioned multiple stacked separators are folded in sequence and an adhesive is applied thereon, so that the applied adhesive may not penetrate between adjacent separators.

[0016] One surface of the electrode assembly may include a first region in which the end of at least some of the separators among the plurality of stacked separators is bent in a first direction, and a second region in which the end of at least some of the separators among the plurality of stacked separators is bent in a second direction.

[0017] In the first region, the end of the separator is bent in the first direction from the separator of the uppermost layer of the electrode assembly, and the adhesive application region is formed by extending from the separator of the uppermost layer, and in the second region, the end of the separator is bent in the second direction from the separator of the lowermost layer of the electrode assembly, and the adhesive application region can be formed by extending from the separator of the lowermost layer.

[0018] The adhesive application area may be integrally formed by applying the adhesive across the first area and the second area.

[0019] The first region and the second region may be arranged side by side in the horizontal direction of the electrode assembly.

[0020] The above first direction and the above second direction may be different.

[0021] The first direction may be a direction facing downward of the electrode assembly, and the second direction may be a direction facing upward of the electrode assembly.

[0022] In the first region, the direction in which the outermost edge of the folded separator faces may have an angle greater than 0 degrees and less than or equal to 90 degrees downward relative to the horizontal axis of the electrode assembly, and in the second region, the direction in which the outermost edge of the folded separator faces may have an angle greater than 0 degrees and less than or equal to 90 degrees upward relative to the horizontal axis of the electrode assembly.

[0023] An electrode assembly in which at least the lowest layer of the electrode assembly in the first region is not folded, and at least the uppermost layer of the electrode assembly in the second region is not folded.

[0024] One side of the electrode assembly may further include a third region in which the direction in which the end of the separator is bent is changed between the first region and the second region.

[0025] The adhesive application area may be included on the third area above.

[0026] The adhesive application area in the first region and the adhesive application area in the second region are formed spaced apart from each other in the horizontal direction of the electrode assembly and may have a height that overlaps with each other in the height direction of the electrode assembly.

[0027] At least one of the adhesive application area in the first region and the adhesive application area in the second region may include an application area that extends further than half the height of the electrode assembly.

[0028] When viewed from the one side of the electrode assembly, the set of the first region, the second region, and the adhesive application region may be provided as a plurality of sets.

[0029] A set of the first region, the second region, and the adhesive application region may be provided on at least one of the two sides in the long side direction and the two sides in the short side direction of the electrode assembly.

[0030] The electrode assembly further includes an electrode tab on at least one of the opposing sides, and a set of the first region, the second region, and the adhesive application region may be provided on each side based on the electrode tab.

[0031] According to the present invention, the efficiency of the separator bonding process of an electrode assembly can be maximized, and the production cost of the electrode assembly can be lowered while maintaining or improving the quality of the electrode assembly.

[0032] As the area where the adhesive is applied is formed in a diagonal direction, simultaneous bonding in the height direction and the horizontal direction can be achieved between multiple stacked separators of the electrode assembly.

[0033] The effects of the present invention are not limited to those mentioned above, and other unmentioned effects will be clearly understood by those skilled in the art from the description in the claims.

[0034] FIG. 1 schematically illustrates a method of bonding a separator of an electrode assembly according to conventional technology.

[0035] FIG. 2 schematically illustrates a membrane bonding process according to one embodiment of the present invention.

[0036] FIG. 3 illustrates embodiments of the push unit of FIG. 2.

[0037] Figure 4 shows a partially enlarged view of the electrode assembly in the state where the adhesive application is completed in Figure 2 (c).

[0038] Figure 5 schematically illustrates the application principle of the adhesive of the present invention by enlarging the part indicated by the dotted line in Figure 4.

[0039] FIG. 6 illustrates a case where the separator bonding process performed on one side of the electrode assembly in the embodiment of FIG. 2 is performed in the same way on the other side of the electrode assembly.

[0040] Figure 7 illustrates Figure 2 from a different angle (i.e., an orthogonal angle).

[0041] FIG. 8 illustrates one embodiment of FIG. 7.

[0042] Figure 9 shows a partial enlarged view of Figure 8.

[0043] FIG. 10 illustrates another embodiment of FIG. 7.

[0044] FIG. 11 illustrates another embodiment of FIG. 10 and FIG. 7.

[0045] FIG. 12 illustrates an embodiment of the bonding of the separator of the electrode assembly described above in FIG. 2 to FIG. 11.

[0046] FIG. 13 illustrates a comparative example of the present invention.

[0047] Hereinafter, various embodiments of the present invention will be described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. The present invention may be embodied in various different forms and is not limited to the embodiments described herein.

[0048] To clearly explain the present invention, parts unrelated to the explanation have been omitted, and the same reference numerals are used for identical or similar components throughout the specification.

[0049] Furthermore, the size and thickness of each component shown in the drawings are depicted arbitrarily for convenience of explanation, and thus the present invention is not necessarily limited to what is illustrated. Thicknesses have been enlarged in the drawings to clearly represent various layers and regions. Additionally, for convenience of explanation, the thickness of some layers and regions has been exaggerated in the drawings.

[0050] Furthermore, when a part such as a layer, membrane, region, or plate is said to be "on" or "on" another part, this includes not only the case where it is "directly on" another part, but also the case where there is another part in between. Conversely, when a part is said to be "directly on" another part, it means that there is no other part in between. Also, saying that a part is "on" or "on" a reference part means that it is located above or below the reference part, and does not necessarily mean that it is located "on" or "on" facing the opposite direction of gravity.

[0051] Furthermore, throughout the specification, when a part is described as "including" a certain component, this means that, unless specifically stated otherwise, it does not exclude other components but may include additional components.

[0052] Additionally, throughout the specification, "planar" means when the subject part is viewed from above, and "cross-sectional" means when the cross-section obtained by vertically cutting the subject part is viewed from the side.

[0053] Hereinafter, embodiments of the present invention will be described with reference to the drawings.

[0054] FIG. 2 schematically illustrates a membrane bonding process according to one embodiment of the present invention. FIG. 3 illustrates embodiments of the push unit (10) of FIG. 2.

[0055] First, FIG. 2(a) illustrates an electrode assembly (1) in a stacked state. The electrode assembly (1) includes a separator (100) and a first electrode plate (110) and a second electrode plate (120) having different polarities. The first electrode plate (110) is either a negative electrode plate or a positive electrode plate, and the second electrode plate (120) is the other of a negative electrode plate and a positive electrode plate. The first electrode plate (110) and the second electrode plate (120), having different polarities, are alternately stacked with the separator (100) in between.

[0056] In FIG. 2(a), an electrode assembly (1) stacked using a lamination and stacking method is illustrated as an example, in which a plurality of monocells, each consisting of a single electrode plate and a separator, are stacked. However, it should be noted that the present invention is not limited to what is illustrated and can also be applied to an electrode assembly (1) stacked using a Z-stacking method.

[0057] Next, referring to FIG. 2(b), according to one embodiment of the present invention, at least one of the four sides excluding the upper and lower surfaces of the electrode assembly (1) is pressed by a push unit (10) to bend at least a portion of the multiple stacked separators (100). To elaborate, the portion where the multiple stacked separators (100) in the electrode assembly (1) are stacked together is bent by extending further from the end (outermost edge) of the electrode plate (i.e., the first electrode plate (110) and / or the second electrode plate (120)).

[0058] In the specification of the present invention, the term “folding” of the separator (100) means that the portion of the separator (100) where the electrode plate extends further from the end (referred to as “end of the separator (100) for convenience of explanation”) is inclined from the direction parallel to the adjacent electrode plate, so that the end of the separator (100) faces a direction different from the direction parallel to the adjacent electrode plate.

[0059] The “folding” of the separator (100) may be such that the end portion of the separator (100) (i.e., the portion of the separator (100) that extends further from the end of the electrode plate) is gently curved from the area where the separator (100) faces the electrode plate, or it may be bent at one part. In the former case, it may be bent in a round shape between the area where the separator (100) faces the electrode plate and the area where the separator (100) is folded. In the latter case, the separator (100) may be bent to form an angle of inclination between the area where the separator (100) faces the electrode plate and the area where the separator (100) is folded.

[0060] In the embodiment of FIG. 2, one side of the electrode assembly (1) and the other side facing it are illustrated exemplarily based on the two sides in the horizontal direction (width direction; X-axis direction of FIG. 2) of the electrode assembly (1). However, the present invention is not limited thereto, and the description of the embodiment of the present invention to be described below from FIG. 2 may be applied in the same manner to one or both sides in the vertical direction (length direction; Y-axis direction of FIG. 2) of the electrode assembly (1), where an electrode tab (not shown) is located on one or both sides, and to one or both sides in the vertical direction of the electrode assembly (1). That is, the present invention may be applied as a substitute for either the separator sealing on the long side or the separator sealing on the short side of the electrode assembly (1), but the present invention may also be applied to both the long and short sides of the electrode assembly (1).

[0061] A push unit (10) is positioned along the height direction of the electrode assembly (1) (the Z-axis direction in FIG. 2, the direction in which the electrode assembly is stacked) and presses a plurality of stacked separators (100). At this time, as shown in FIG. 6 and others, the push unit (10) may press a part of the one surface of the electrode assembly (1). Or, in some cases, it may press the entire one surface of the electrode assembly (1).

[0062] The portion of the separator (100) folded by the push unit (10) is formed to cover the side of each of the first electrode plate (110) and the second electrode plate (120). Preferably, the portion of the separator (100) folded may cover the entire side of each of the first electrode plate (110) and the second electrode plate (120) (see FIG. 4(a)). However, the present invention is not limited thereto, and depending on the length of the separator (100) or the degree of folding of the separator (100), the side of each of the first electrode plate (110) and the second electrode plate (120) may be partially exposed between the respective folded portions of adjacent separators (100) (see FIG. 4(b)).

[0063] FIG. 3 illustrates various exemplary embodiments in which a push unit (10) presses and bends a separator (100) on one side of an electrode assembly (1). First, FIG. 3 illustrates an example in which the separator (100) of the electrode assembly (1) is bent in a direction opposite to the stacking direction of the electrode assembly (1) (the -Z-axis direction in FIG. 3).

[0064] In FIG. 3(a), the push unit (10) may be positioned above adjacent to the side of the electrode assembly (1), and then move in the opposite direction (downward) to the stacking direction of the electrode assembly (1), thereby pressing and bending the stacked separators (100) from the top layer separator (100) of the electrode assembly (1) in sequence.

[0065] In FIG. 3(b), the push unit (10) may be positioned above and spaced apart from the side of the electrode assembly (1), and then move downward at an angle toward the electrode assembly (1), thereby pressing and bending the stacked separators (100) from the top layer of the electrode assembly (1) downward in sequence.

[0066] In Fig. 3(c), the push unit (10) may press and bend the uppermost separator (100) of the electrode assembly (1) while rotating with the end of the uppermost separator (100) as the axis of rotation, and then press and bend the stacked separators (100) one after another.

[0067] The present invention is not limited to the embodiment shown in FIG. 3, and can be applied by various modifications and changes depending on the environment in which the present invention is implemented or the type and specifications of the electrode assembly.

[0068] Referring again to FIG. 2, an adhesive (A) is applied as in FIG. 2 (c) over a separator (100) that is pressed and folded by a push unit (10) as in FIG. 2 (b).

[0069] As shown in FIG. 2(c), the adhesive application unit (20) may apply the adhesive (A) while moving along the area to be applied. Alternatively, the adhesive application unit (20) may be equipped with multiple nozzles or one large nozzle, so that the adhesive application unit (20) applies the adhesive (A) to the area to be applied at once while the adhesive application unit (20) is fixed.

[0070] The adhesive (A) may be applied to the folded separator (100) of the electrode assembly (1) using a line application method or a surface application method. Here, the line application method or the surface application method means applying the adhesive (A) densely so that the adhesive (A) is applied without gaps at the target location where the adhesive (A) is to be applied. Among these, the line application method means that the adhesive (A) applied to the folded separator (100) is applied in the form of a line that is generally narrow in width and long in length. The surface application method means that it is applied in the form of a surface that is wider in width and long in length than the line application method.

[0071] There are no special restrictions on the method of applying the adhesive (A), and as illustrated in FIG. 4, which will be described later, it is sufficient that the applied adhesive (A) does not enter the gap between adjacent separators (100) and does not come into contact with the first electrode plate (110) or the second electrode plate (120) located in that part. For example, the adhesive (A) can be applied by inkjet application, spray application, slot application, or other methods.

[0072] After the adhesive (A) is applied, a separate curing process may or may not be required depending on the type of adhesive (A). For example, the curing of the adhesive (A) may be thermal curing or UV curing, but the present invention is not limited thereto, and it is sufficient if the curing of the adhesive (A) is performed to an extent that does not affect the performance of the electrode assembly (1). In some cases, if the adhesive (A) cures quickly, a separate curing process may not be required.

[0073] FIGS. 4 and FIGS. 5 each illustrate a state in which an adhesive (A) is applied to a folded separator (100) of an electrode assembly (1) according to one embodiment of the present invention.

[0074] FIG. 4 shows a partially enlarged view of the electrode assembly (1) in the state where the adhesive (A) is applied in FIG. 2 (c). FIG. 5 shows a schematic diagram of the principle of applying the adhesive (A) of the present invention by enlarging the part indicated by the dotted line in FIG. 4.

[0075] First, referring to the embodiment of FIG. 4 (a), the folded regions of adjacent separators (100) may overlap each other. That is, the separators (100) may be folded in succession in the stacking direction of the separators (100) of the electrode assembly (1) or in the opposite direction.

[0076] In this case, the side surface of the first electrode plate (110) or the second electrode plate (120) interposed between two adjacent separators (100) is covered entirely with respect to the bending direction of the end of the separator (100) (height direction, Z-axis direction of the electrode assembly (1) in FIG. 4). As will be described later in FIG. 7 and FIG. 8, it should be noted that this does not mean that it is also covered entirely in the horizontal direction (width direction; X-axis direction in FIG. 4) and vertical direction (length direction; Y-axis direction in FIG. 4) of the electrode assembly (1).

[0077] Accordingly, as schematically illustrated in FIG. 5, the adhesive (A) applied to the separator (100) folded along the bending direction of the end of the separator (100) can be prevented from unintentionally penetrating between two adjacent separators (100).

[0078] Alternatively, referring to the embodiment of FIG. 4(b), even if the folded regions of adjacent separators (100) do not overlap each other, the folded portion of the separator (100) may cover the sides of the first electrode plate (110) and the second electrode plate (120), respectively, entirely based on the folded direction of the end of the separator (100) (the height direction of the electrode assembly (1) in FIG. 4, the Z-axis direction).

[0079] In some cases, in the embodiment of FIG. 4 (b), depending on the length of the separator (100) or the degree of bending of the separator (100), the sides of the first electrode plate (110) and the second electrode plate (120) may be partially exposed between the respective bent portions of adjacent separators (100) with respect to the bending direction of the end of the separator (100) (height direction, Z-axis direction of the electrode assembly (1) in FIG. 4).

[0080] In the embodiment of FIG. 4 (b), whether in the former case or the latter case, the adhesive (A) applied on the folded separator (100) can be prevented from unintentionally penetrating between two adjacent separators (100).

[0081] In the latter case, various modifications and changes are possible, such as the side of each of the first electrode plate (110) and the second electrode plate (120) being exposed within the error range when implementing the former case, or using an adhesive (A) with higher viscosity or faster curing so that the adhesive (A) applied on the folded separator (100) does not unintentionally penetrate between two adjacent separators (100).

[0082] For reference, in FIG. 17 as a comparative example of FIG. 4, when the end of the separator (100) is not pressed by the push unit (10) and the end of the separator (3) is not bent, the adhesive (A) flows between two adjacent separators (3) and unintentionally penetrates to the electrode plates (4, 5).

[0083] FIG. 6 illustrates a case where the separator bonding process performed on one side of the electrode assembly (1) in the embodiment of FIG. 2 is performed in the same way on the other side of the electrode assembly (1).

[0084] FIG. 6(a) shows the state in which the separator bonding process performed on one side of the electrode assembly (1) of FIG. 2 is completed. Referring to FIG. 6(b), the other side facing the one side of the electrode assembly (1) (see FIG. 2) is pressed by a push unit (10) to fold a plurality of stacked separators (100). Next, as shown in FIG. 6(b), an adhesive (A) is applied over the separator (100) that has been folded by pressing with the push unit (10) as shown in FIG. 6(b), as shown in FIG. 6(c).

[0085] The separator bonding process performed on the other side of the electrode assembly (1) of FIG. 6 is identical to the separator bonding process performed on one side of the electrode assembly (1) of FIG. 2, except that the location where the separator bonding is performed is different; therefore, for a detailed explanation, refer to FIG. 2 to FIG. 5.

[0086] In addition, it should be noted that the present invention is not limited to what is described above, and the separator bonding process of FIGS. 2 and FIGS. 6 may be performed simultaneously. That is, the separator bonding process may be performed simultaneously on one side and the other side of the electrode assembly (1) as described above in FIGS. 2 and FIGS. 6.

[0087] FIG. 7 illustrates FIG. 2 (particularly FIG. 2 (b) and (c))) from different angles (orthogonal angles).

[0088] For example, while FIGS. 2 and FIGS. 6 correspond to a view from one of the front and rear sides of the electrode assembly (1), FIGS. 7 corresponds to a view from one of the left and right sides of the electrode assembly (1). FIGS. 7 illustrates, for example, a view from the right side (+X-axis in FIGS. 2) of the electrode assembly (1). However, it should be noted that the present invention is not limited thereto and can be applied in the same way to a view from the left side (-X-axis in FIGS. 6) of the electrode assembly (1).

[0089] Referring to FIG. 7, the adhesive (A) is applied so as to be inclined at a predetermined angle (in a diagonal direction) with respect to the height direction (Z-axis direction in FIG. 7) of the electrode assembly (1). In other words, the longitudinal direction of the applied adhesive (A) is formed so as to be inclined at a predetermined angle with respect to the height direction (Z-axis direction in FIG. 7) of the electrode assembly (1). The predetermined angle may be any value selected from, for example, greater than 0 degrees and less than or equal to 80 degrees with respect to the height direction of the electrode assembly (1), or any value selected from, for example, greater than 10 degrees and less than or equal to 70 degrees, or any value selected from, for example, greater than 30 degrees and less than or equal to 60 degrees.

[0090] As the area where the adhesive (A) is applied is formed to be inclined at a predetermined angle (in a diagonal direction) with respect to the height direction (Z-axis direction in FIG. 7) of the electrode assembly (1), the connection between the multiple stacked separators (100) of the electrode assembly (1) in the height direction and the horizontal direction can be simultaneously realized.

[0091] Figure 7 (a) illustrates a case where an adhesive (A) is applied to a separator (100) that has been folded such that, for example, with respect to the height direction (Z-axis direction of Figure 7) of the electrode assembly (1), the folding direction of the end of the separator (100) faces downward from the electrode assembly (1).

[0092] In FIG. 7(b), for example, an adhesive (A) is applied to a separator (100) that has been folded such that the folding direction of the end of the separator (100) is facing upward with respect to the height direction (Z-axis direction of FIG. 7) of the electrode assembly (1).

[0093] In the specification of the present invention, the meaning that the bending direction of the end of the separator (100) is directed toward the bottom of the electrode assembly (1) means that the part of the separator (100) that extends further from the end (outermost edge) of the electrode plate is bent or tilted downward. At this time, the direction in which the end (outermost edge) of the separator (100) faces has an angle greater than 0 degrees and less than or equal to 90 degrees in the -Z axis direction with respect to the horizontal axis (i.e., the axis parallel to the large area of ​​the electrode assembly, e.g., the X-axis).

[0094] Likewise, the meaning that the bending direction of the end of the separator (100) is directed toward the top of the electrode assembly (1) is that the part of the separator (100) that extends further from the end (outermost edge) of the electrode plate is bent or tilted upward. At this time, the direction in which the end (outermost edge) of the separator (100) faces has an angle greater than 0 degrees and less than or equal to 90 degrees in the +Z axis direction with respect to the horizontal axis (i.e., the axis parallel to the large area of ​​the electrode assembly, e.g., the X-axis).

[0095] Figure 7 illustrates a part of the electrode assembly (1), and the adhesive (A) may be applied entirely along the height direction (Z-axis direction in Figure 7) of the electrode assembly (1) from the top layer separator to the bottom layer separator. Alternatively, the adhesive (A) may be applied only to a part of the electrode assembly (1) along the height direction (Z-axis direction in Figure 7) from the top layer separator to the bottom layer separator.

[0096] Whether in the former case or the latter case, according to one embodiment of the present invention, the longitudinal direction of the applied adhesive (A) is inclined at a predetermined angle with respect to the height direction of the electrode assembly (1). Furthermore, the present invention is not limited to what is shown in FIG. 7, and the longitudinal direction of the applied adhesive (A) may be inclined symmetrically to the left and right as shown in FIG. 7.

[0097] FIG. 8 illustrates an embodiment of FIG. 7. FIG. 9 is a partial enlarged view of FIG. 8, where FIG. 9 (a) shows a first region (P1) of FIG. 8 in a perspective view, and FIG. 9 (b) shows a second region (P2) of FIG. 8 in a perspective view.

[0098] FIG. 8 illustrates, for example, a view from the right side (+X-axis of FIG. 2) of the electrode assembly (1). However, it should be noted that the present invention is not limited thereto and can be applied in the same way when viewed from the left side (-X-axis of FIG. 6) of the electrode assembly (1). That is, FIG. 8 may correspond to a view of one side of the electrode assembly (1) of FIG. 2, or a view of the other side of the electrode assembly (1) of FIG. 6.

[0099] According to one embodiment of FIG. 8, one side and / or the other side of the electrode assembly (1) in the longitudinal direction of the electrode assembly (1) largely comprises a first region (P1) and a second region (P2) along the longitudinal direction of the electrode assembly (1) (length direction of the electrode assembly (1); Y-axis direction of FIG. 8).

[0100] The direction in which the end of the separator (100) is bent in the first region (P1) and the direction in which the end of the separator (100) is bent in the second region (P2) are different.

[0101] For example, based on the height direction of the electrode assembly (1) (Z-axis direction in FIG. 8), if the bending direction of the end of the separator (100) in the first region (P1) is directed toward the bottom of the electrode assembly (1), then the bending direction of the end of the separator (100) in the second region (P2) is directed toward the top of the electrode assembly (1).

[0102] At this time, when the end (outermost edge) of the separator (100) is pressed by the push unit (11) in the first region (P1), the direction in which it faces has an angle greater than 0 degrees and less than or equal to 90 degrees in the -Z axis direction relative to the X axis.

[0103] Likewise, in the second region (P2), when pressed by the push unit (11), the direction in which the end (outermost edge) of the separator (100) faces has an angle greater than 0 degrees and less than or equal to 90 degrees in the +Z axis direction relative to the X axis.

[0104] Referring to FIGS. 8 and 9, in the example of FIG. 8, in the first region (P1), the first push unit (11) presses the end of the stacked multiple separator membranes (100) so that the bending direction is directed toward the bottom of the electrode assembly (1). In addition, in the second region (P2), the second push unit (12) presses the end of the stacked multiple separator membranes (100) so that the bending direction is directed toward the top of the electrode assembly (1).

[0105]

[0106] With the first push unit (11) pressing the end of the separator (100) in the first region (P1) and the second push unit (12) pressing the end of the separator (100) in the second region (P2), the adhesive application unit (20, see FIG. 9) applies the adhesive (A) in a diagonal direction.

[0107] At this time, an adhesive (A) is applied diagonally (i.e., tilted relative to the height direction of the electrode assembly (1)) from the separator (100-n) located at the top of the electrode assembly (1) in the first region (P1) to the separator (100-1) located at the bottom of the electrode assembly (1) in the second region (P2).

[0108] Meanwhile, depending on the type and thickness of the separator (100), the degree of pressure applied by the push unit (10), etc., in the first region (P1) where the adhesive (A) is not applied, the end of the separator (100) that was bent may be restored in whole or in part after the push unit (11) is removed. That is, in the first region (P1) where the adhesive (A) is not applied, the end of the separator (100) may not be bent after the push unit (11) is removed. Similarly, in the second region (P2) where the adhesive (A) is not applied, the end of the separator (100) that was bent may be restored in whole or in part after the push unit (12) is removed. That is, in the second region (P2) where the adhesive (A) is not applied, the end of the separator (100) may not be bent after the push unit (12) is removed.

[0109] That is, after the adhesive (A) is applied and cured, when the first push unit (11) and the second push unit (12) are removed from the surface of the electrode assembly (1), the separator (100) that was folded by the pressure of the first push unit (11) and the second push unit (12) can be restored by unfolding it again.

[0110] However, in the area where the adhesive (A) provided thereon is applied after being folded in sequence and in the vicinity thereof, the separator (100) maintains the folded shape due to the cured adhesive (A).

[0111] Accordingly, in the first region (P1), the adhesive (A) applied and cured allows the separator (100-n) located at the top layer and the partial separator (100) located nearby and folded in sequence to maintain a state in which they are folded downwards. That is, it prevents the separator (100-1) located at the bottom layer and the partial separator (100) located nearby and folded in sequence from protruding outward from the electrode assembly (1) beyond the outermost edge (bottom surface) of the electrode assembly (1).

[0112] Likewise, in the second region (P2), the applied and cured adhesive (A) allows the separator (100-1) located at the bottom layer and the portion of the separator (100) located near it, which are sequentially folded, to maintain a state in which they are folded upward. That is, it prevents the separator (100-n) located at the top layer and the portion of the separator (100) located near it, which are sequentially folded, from protruding outward from the outermost edge (topmost surface) of the electrode assembly (1).

[0113] This can prevent problems that may occur as the folded portion of the separator (100) of the electrode assembly (1) protrudes outward from the electrode assembly (1) beyond the uppermost or lowermost surface of the electrode assembly (1) (e.g., having an unwanted effect on the alignment of the electrode assembly (1)). In addition, space efficiency can be increased when the electrode assembly (1) is housed inside the case of the battery cell.

[0114] In addition, the outermost separator (i.e., the lowest layer separator (100-1) or the top layer separator (100-n)) among the multiple stacked separators (100) of the electrode assembly (1) can be protected from adhesion or contamination.

[0115]

[0116] Meanwhile, referring to FIG. 8, since the bending direction of the end of the separator (100) in the first region (P1) of the electrode assembly (1) and the bending direction of the end of the separator (100) in the second region (P2) of the electrode assembly (1) are different from each other, a third region (P3) may be included between the first region (P1) and the second region (P2) of the electrode assembly (1) as a transition region that changes the bending direction of the end of the separator (100). In this case, the gap between the first region (P1) and the second region (P2) can be designed and implemented such that the adhesive (A) does not penetrate between the stacked separator (100) even in the third region (P3), and the gap can be implemented according to the process environment in which the present invention is implemented or the specifications of the electrode assembly.

[0117] In the third region (P3), the end (outermost edge) of at least some of the folded portions of the multiple stacked separators (100) may have a shape that is inclined with respect to the horizontal axis of the electrode assembly (1) (e.g., the Y-axis direction in FIG. 8). In some cases, at least some of the multiple stacked separators (100) in the third region (P3) may not be folded.

[0118] Meanwhile, the adhesive (A) may be applied at once between the first region (P1) and the second region (P2) (including, in some cases, the third region (P3) which is a transition region between them), as shown in FIG. 8.

[0119] Alternatively, in some cases, the adhesive (A) may be applied separately between the first region (P1) and the second region (P2), as in the modified embodiment of FIG. 10 or FIG. 11.

[0120] FIG. 10 illustrates another embodiment of FIG. 7, and FIG. 11 illustrates yet another embodiment of FIG. 7. FIG. 10 is a modified embodiment of FIG. 8, and FIG. 11 is a modified embodiment of FIG. 10.

[0121] The adhesive (A) applied including the first region (P1) is referred to as “A1” for convenience, and the adhesive (A) applied including the second region (P2) is referred to as “A2” for convenience.

[0122] In FIGS. 10 and 11, an adhesive (A1) is applied in a diagonal direction between the first region (P1) and the third region (P3) at once, and an adhesive (A2) is applied in a diagonal direction between the second region (P2) and the third region (P3) at once. The adhesive (A1) applied including the first region (P1) and the adhesive (A2) applied including the second region (P2) are spaced apart from each other in the longitudinal direction of the electrode assembly (1).

[0123] For example, instead of the embodiment of FIG. 8, it may be implemented in the embodiment of FIG. 10 or FIG. 11 when the gap between the first region (P1) where the separator (100) is pressed and folded by the first push unit (11) and the second region (P2) where the separator (100) is pressed and folded by the second push unit (12) is relatively larger, or when the size of the electrode assembly (1) is relatively larger.

[0124] In FIGS. 10 and 11, while the first push unit (11) presses the end of the separator (100) in the first region (P1), the adhesive application unit (20, see FIG. 9) applies the adhesive (A; A1) in a diagonal direction from the separator (100-n) located on the uppermost layer of the electrode assembly (1) in the first region (P1) to the third region (P3).

[0125] At this time, in the first region (P1), the adhesive (A1) is not applied to the separator (100-1) located at the bottom layer of the electrode assembly (1) and the separator (100) in the vicinity thereof. That is, it is possible to prevent the separator (100-1) located at the bottom layer and the separator (100) located in the vicinity thereof, which are folded in sequence, from protruding outwardly from the outermost edge (bottom surface) of the electrode assembly (1) to the outside of the electrode assembly (1).

[0126] Additionally, while the second push unit (12) presses the end of the separator (100) in the second region (P2), the adhesive application unit (20, see FIG. 9) applies the adhesive (A; A2) in a diagonal direction from the separator (100-1) located at the bottom layer of the electrode assembly (1) in the second region (P2) to the third region (P3).

[0127] At this time, in the second region (P2), the adhesive (A2) is not applied to the separator (100-n) located on the uppermost layer of the electrode assembly (1) and the separator (100) in the vicinity thereof. That is, it is possible to prevent the separator (100-n) located on the uppermost layer and the portion of the separator (100) that is folded sequentially in the vicinity thereof from protruding outwardly from the outermost edge (uppermost surface) of the electrode assembly (1) to the outside of the electrode assembly (1).

[0128] In the example of FIG. 10, an adhesive (A1) and an adhesive (A2) are each applied to the entire electrode assembly (1) along the height direction from the separator (100-n) located at the top layer to the separator (100-1) located at the bottom layer.

[0129] In the example of FIG. 11, the adhesive (A1) is applied diagonally from the separator (100-n) located at the top layer of the electrode assembly (1) in the first region (P1) to the third region (P3), but only partially applied with respect to the height direction of the electrode assembly (1). Additionally, the adhesive (A2) is applied diagonally from the separator (100-1) located at the bottom layer of the electrode assembly (1) in the second region (P2) to the third region (P3), but only partially applied with respect to the height direction of the electrode assembly (1). In FIG. 11, the push unit is omitted for ease of understanding, but the details regarding the push unit are described in FIG. 8 and FIG. 10.

[0130]

[0131] In the case of FIG. 11, the adhesive (A1) applied including the first region (P1) and the adhesive (A2) applied including the second region (P2) have a height (h) that overlaps with each other in the height direction of the electrode assembly (1). s has ).

[0132] To elaborate, the adhesive (A1) applied to the first region (P1) is applied in the height direction of the electrode assembly (1) from either the bottom layer separator (100-1) or the top layer separator (100-n) of the electrode assembly (1). Additionally, the adhesive (A2) applied to the second region (P2) is applied in the height direction of the electrode assembly (1) from the other of the bottom layer separator (100-1) and the top layer separator (100-n). At this time, the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) overlap each other in the height direction of the electrode assembly (1) at a height (h s has ).

[0133] Accordingly, even if the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) are applied spaced apart from each other in the vertical direction of the electrode assembly (1), they are ultimately applied to all separators (100) in the height direction of the electrode assembly (1). Therefore, in the case where the adhesive (A1) applied to the first region (P1) is applied only partially along the height direction of the electrode assembly (1) and the adhesive (A2) applied to the second region (P2) is applied only partially along the height direction of the electrode assembly (1), it is possible to prevent the concern that some of the separators (100) along the height direction of the electrode assembly (1) will not be applied.

[0134] As an example, as illustrated in FIG. 11, the adhesive (A1) applied to the first region (P1) is applied at least partially along the height of the electrode assembly (1) from the separator (100) located at the top layer of the electrode assembly (1) (along the -Z axis direction of FIG. 11), and along the centerline (C) in the horizontal direction of the electrode assembly (1). h It can be applied extending further than ). Additionally, the adhesive (A2) applied to the second region (P2) is applied at least partially along the height of the electrode assembly (1) (along the +Z axis direction in FIG. 11) from the separator (100) located at the bottom layer of the electrode assembly (1), and along the centerline (C) in the horizontal direction of the electrode assembly (1). h It can be applied with a longer extension than ).

[0135] Here, the centerline (C) in the horizontal direction h ) means a line that evenly divides the electrode assembly (1) along the height direction of the electrode assembly (1).

[0136] To summarize, the above example is such that the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) are each along the centerline (C) in the horizontal direction of the electrode assembly (1). h This corresponds to a case where it is applied extending further than ), and in this case, the overlapping height of the adhesive (A1) applied in the first region (P1) and the adhesive (A2) applied in the second region (P2) is the centerline (C) in the horizontal direction. h It will be located in the vicinity of ).

[0137] To elaborate, in the example described above, the height (h1) of the adhesive (A1) applied to the first region (P1) may be greater than half the height (H) of the electrode assembly (1) and equal to or less than the height (H) of the electrode assembly (1), where the lowest surface of the electrode assembly (1) is set to 0. That is, it has the relationship 1 / 2 × (H) < (h1) ≤ (H) (where H is the dimension in the height direction of the electrode assembly). Similarly, the height (h2) of the adhesive (A2) applied to the second region (P2) may be greater than half the height (H) of the electrode assembly (1) and equal to or less than the height (H) of the electrode assembly (1), where the lowest surface of the electrode assembly (1) is set to 0. That is, it has the relationship 1 / 2 × (H) < (h2) ≤ (H) (where H is the dimension in the height direction of the electrode assembly).

[0138] The present invention is not limited to what is exemplarily illustrated in FIG. 11, and the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) have a height (h) that overlaps with each other in the height direction of the electrode assembly (1). s It is also possible to implement the height (h1) of the adhesive (A1) applied to the first region (P1) by adjusting the height (h2) of the adhesive (A2) applied to the second region (P2).

[0139] Accordingly, when the lowest surface of the electrode assembly (1) is set to 0, for example, the portion where the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) overlap in the height direction is the centerline (C) of the electrode assembly (1) in the horizontal direction. h Located below ) (i.e., 0<(h s It may also be implemented as )<1 / 2×(H)). Or, for example, the portion where the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) overlap in the height direction is the centerline (C) in the horizontal direction of the electrode assembly (1). hLocated above ) (i.e., 1 / 2×(H)<(h s It can also be implemented as )<(H)).

[0140] In addition, the degree to which the adhesive (A1) applied to the first region (P1) and the adhesive (A2) applied to the second region (P2) overlap each other in the height direction of the electrode assembly (1) (i.e., (h s The size of the electrode assembly (1) can be implemented by varying and changing it according to the environment in which the present invention is implemented and the specifications (size, type, etc.) of the electrode assembly (1).

[0141] In FIGS. 10 and 11, the type of adhesive (A1) and the type of adhesive (A2) may be the same. That is, the same type of adhesive (A) may be applied to the first region (P1) and the second region (P2), respectively, and the areas where the adhesive is applied may be distinguished and labeled as such for convenience in FIG. 8. However, depending on the environment in which the present invention is implemented or the specifications of the electrode assembly (1), the type of adhesive (A1) and the type of adhesive (A2) may be different in some cases.

[0142] For further detailed explanations regarding FIGS. 10 and FIGS. 11, refer to FIG. 8. Meanwhile, although not illustrated in FIGS. 8 to 11, in the opposite case, if the bending direction of the end of the separator (100) in the first region (P1) of the electrode assembly (1) is directed toward the top of the electrode assembly (1), it can also be implemented in the case where the bending direction of the end of the separator (100) in the second region (P2) of the electrode assembly (1) is directed toward the bottom of the electrode assembly (1).

[0143] In addition, depending on the environment in which the present invention is implemented or the specifications (type, size, etc.) of the electrode assembly (1), various modifications and changes are possible, such as implementing the first region (P1) in multiple numbers or implementing the second region (P2) in multiple numbers.

[0144] The above description in FIGS. 2 to 11 may be applied to at least one of the two sides in the horizontal direction (width direction; X-axis direction in FIG. 2) of the electrode assembly (1), may be applied to at least one of the two sides in the vertical direction (length direction; Y-axis direction in FIG. 2), and may be applied to all four remaining sides excluding the upper and lower surfaces of the electrode assembly (1).

[0145] FIG. 12 illustrates an embodiment of the bonding of the separator (100) of the electrode assembly (1) described in FIG. 2 to 11. FIG. 12 exemplarily illustrates a case in which the bonding method of the separator (100) described in FIG. 2 to 11 is applied to all four surfaces of the electrode assembly (1), excluding the upper and lower surfaces (i.e., both sides in the stacking direction of the electrode assembly (1)). That is, it exemplarily illustrates a case in which the bonding method of the separator (100) according to the present invention is applied to both the long and short sides of the electrode assembly (1).

[0146] First, an exemplary case is illustrated in which multiple adhesives (A) are applied to each of the two sides in the horizontal direction (width direction; X-axis direction in FIG. 12) of the electrode assembly (1). Based on one side, the number of applied adhesives (A) may be one or multiple, and the number may be adjusted according to the dimensions in the horizontal direction of the electrode assembly (1).

[0147] Additionally, one or more adhesives (A) applied to each of the two sides in the longitudinal direction (length direction; Y-axis direction in FIG. 12) may be included based on one side. FIG. 12 illustrates, as an example, a case in which one adhesive (A) is applied to each side based on the electrode tab (130). However, the present invention is not limited to what is illustrated, and various modifications are possible, such as providing different numbers of adhesives (A) applied to each side based on the electrode tab (130) depending on the position of the electrode tab (130).

[0148] FIG. 12 illustrates an embodiment in which the embodiment of FIG. 8 is applied as an example. However, the present invention is not limited to what is shown in FIG. 12, and it is understood that the present invention can be implemented by applying the embodiment of FIG. 10 or FIG. 11, or by applying a modified version thereof to suit the actual implementation of the present invention.

[0149] The embodiments of the present invention described in FIGS. 2 to 12 can be advantageously applied in cases where the sealing of the separator (100) is not well achieved by the conventional long-side and / or short-side sealing method (see FIG. 1) of heating and pressurizing the separator (100).

[0150] By applying embodiments of the present invention instead of the conventional long side and / or short side sealing method while lowering the unit cost of the separator (100), the bonding of the separator (100) of the electrode assembly (1) can be easily implemented.

[0151] In addition, according to the embodiments of the present invention, even compared to the comparative example of the present invention in Fig. 13 below, concerns regarding the degradation of electrode performance that may occur when an adhesive enters the gap between the stacked separators and comes into contact with the electrode plate can also be resolved.

[0152] For reference, FIG. 13 illustrates a comparative example of the present invention in which, when the end of the separator (100) is not pressed by a push unit (10) and the end of the separator (3) is not folded, the adhesive (A) flows between two adjacent separators (3) and unintentionally penetrates to the electrode plates (4, 5). In the comparative example, since the adhesive (A) is present on the surface of the electrode plates (4, 5), this may cause a decrease in the performance of the electrode, and consequently, a decrease in the quality of the produced electrode assembly (1) and battery cell.

[0153] Although preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention as defined in the following claims also fall within the scope of the present invention.

[0154] [Explanation of the symbol]

[0155] 1: Electrode assembly

[0156] 10: Push unit

[0157] 20: Adhesive application unit

[0158] 100: Separator

[0159] 110: First electrode plate

[0160] 120: Second electrode plate

[0161] A: Adhesive

[0162] P1: Area 1

[0163] P2: Area 2

[0164] P3: Third Area

Claims

1. On at least one side surface of the electrode assembly, there is a region in which the end of at least some of the separators among the plurality of stacked separators is bent, and an adhesive application region in which an adhesive is applied over the bent separator. The above adhesive application area is an electrode assembly in which the adhesive is applied diagonally at an angle with respect to the height direction of the electrode assembly.

2. In Paragraph 1, An electrode assembly in which at least some of the ends of the separators among the plurality of stacked separators are folded in sequence and an adhesive is applied thereon, such that the applied adhesive does not penetrate between adjacent separators.

3. In Paragraph 1, The electrode assembly comprises, wherein one surface of the electrode assembly comprises a first region in which the end of at least some of the separators among the plurality of stacked separators is bent in a first direction and a second region in which the end of at least some of the separators among the plurality of stacked separators is bent in a second direction.

4. In Paragraph 3, In the first region, the end of the separator is bent in the first direction from the separator of the uppermost layer of the electrode assembly, and the adhesive application region is formed by extending from the separator of the uppermost layer. An electrode assembly in which, in the second region, the end of the separator is bent in the second direction from the separator of the lowest layer of the electrode assembly, and the adhesive application region is formed by extending from the separator of the lowest layer.

5. In Paragraph 3, The above adhesive application area is an electrode assembly formed integrally by applying the adhesive across the first area and the second area.

6. In Paragraph 3, The first region and the second region are arranged side by side in the horizontal direction of the electrode assembly, the electrode assembly.

7. In Paragraph 3, The above first direction and the above second direction are different electrode assemblies.

8. In Paragraph 3, An electrode assembly in which the first direction is a direction toward the bottom of the electrode assembly and the second direction is a direction toward the top of the electrode assembly.

9. In Paragraph 8, In the first region, the direction in which the outermost edge of the folded separator faces has an angle of greater than 0 degrees and less than or equal to 90 degrees downward with respect to the horizontal axis of the electrode assembly, An electrode assembly in which the direction in which the outermost edge of the folded separator in the second region faces has an angle of greater than 0 degrees and less than or equal to 90 degrees upward with respect to the horizontal axis of the electrode assembly.

10. In Paragraph 3, An electrode assembly in which at least the lowest layer of the electrode assembly in the first region is not folded, and at least the uppermost layer of the electrode assembly in the second region is not folded.

11. In Paragraph 3, An electrode assembly, wherein one side of the electrode assembly further comprises a third region in which the direction in which the end of the separator is bent is changed between the first region and the second region.

12. In Paragraph 11, An electrode assembly comprising the adhesive application area on the third area.

13. In Paragraph 3, The adhesive application area in the first region and the adhesive application area in the second region are formed spaced apart from each other in the horizontal direction of the electrode assembly and have heights that overlap each other in the height direction of the electrode assembly, an electrode assembly.

14. In Paragraph 13, An electrode assembly comprising at least one of the adhesive application area in the first region and the adhesive application area in the second region, the application area extending further than half the height of the electrode assembly.

15. In Paragraph 3, An electrode assembly in which, when viewed from one side of the electrode assembly, the set of the first region, the second region, and the adhesive application region is provided as a plurality of sets.

16. In Paragraph 3, An electrode assembly having a set of the first region, the second region, and the adhesive application region provided on at least one of the two sides in the long side direction and the two sides in the short side direction of the electrode assembly.

17. In Paragraph 3, The electrode assembly further includes an electrode tab on at least one of the opposing sides, and An electrode assembly having a set of the first region, the second region, and the adhesive application region, respectively, on both sides based on the electrode tab.

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