Battery cell
Patent Information
- Authority / Receiving Office
- WO · WO
- Patent Type
- Applications
- Current Assignee / Owner
- LG ENERGY SOLUTION LTD
- Filing Date
- 2026-01-08
- Publication Date
- 2026-07-30
Smart Images
Figure KR2026000472_30072026_PF_FP_ABST
Abstract
Description
battery cell
[0001] Cross-citation with related applications
[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2025-0010935 filed on January 24, 2025, and all contents disclosed in the document of said Korean Patent Application are incorporated herein as part of this specification.
[0003] Technology field
[0004] The present invention relates to a battery cell, and more specifically, to a battery cell in which the occurrence of lithium precipitation at the edge of the electrode assembly is reduced and the versatility of the cell use is increased.
[0005] Recently, with rising energy prices due to the depletion of fossil fuels and growing concern over environmental pollution, the demand for eco-friendly alternative energy sources has become an indispensable factor for future life. Accordingly, research on various power generation technologies, such as solar, wind, and tidal power, is ongoing, and there is also significant interest in power storage devices, such as batteries, to utilize this generated electrical energy more efficiently.
[0006] Rechargeable batteries are attracting significant attention as an energy source in various product categories, including mobile devices and electric vehicles. As an excellent energy resource capable of replacing existing products that use fossil fuels, these batteries are gaining prominence as an eco-friendly energy source because they do not generate byproducts associated with energy consumption.
[0007] A battery cell may include an electrode assembly in which electrodes and separators are alternately interposed. Separators may be placed between electrodes and may be attached to the electrodes by applying heat and pressure to the separators. However, in this case, the polymer of the separator may melt again during the high-temperature process, which may weaken the bonding strength. In particular, the bonding at the edges of the separator may weaken, causing gaps between the electrodes and leading to lithium precipitation at the edges.
[0008] The present invention has been devised to solve the above problems, and the objective of the present invention is to provide a battery cell in which the bond between the electrode and the separator at the edge of the electrode assembly can be reliably maintained without artificial pressure in a high-temperature environment.
[0009] A battery cell according to one embodiment of the present invention may include an electrode assembly having an electrode and a separator alternately interposed therein; and an adhesive portion attached to the electrode assembly to fix the electrode and the separator. The adhesive portion may include an inner member disposed on the inside and shrinking when heat is applied; and an outer member disposed on the outside and expanding when heat is applied.
[0010] Each of the inner member and the outer member may include: a first part covering a side of the electrode assembly; a second part connected to one end of the first part and attached to a separator defining one side of the electrode assembly; and a third part connected to the other end of the first part and attached to a separator defining the other side of the electrode assembly.
[0011] The outer member can cover at least a portion of the second and third portions of the inner member.
[0012] The end of the second part of the outer member and the end of the second part of the inner member may be aligned, and the end of the third part of the outer member and the end of the third part of the inner member may be aligned.
[0013] The end of the second part of the outer member may be located outside the end of the second part of the inner member, and the end of the third part of the outer member may be located outside the end of the third part of the inner member.
[0014] The above inner member may include a polymer material.
[0015] The above outer member may include a metallic material.
[0016] The inner member may comprise at least one of linear low-density polyethylene (LLDPE) or ethylene vinyl acetate (EVA), and the outer member may comprise at least one of aluminum or copper.
[0017] When heat is applied, the inner member contracts and the outer member expands, so that the adhesive portion can be bent into an arch shape to press both sides of the electrode assembly.
[0018] The above adhesive portion may include a first adhesive portion covering one side of the electrode assembly and a second adhesive portion covering the other side of the electrode assembly facing the one side.
[0019] The first adhesive portion and the second adhesive portion are provided in a plurality of units, and the plurality of first adhesive portions are spaced apart to cover one side of the electrode assembly, and the plurality of second adhesive portions are spaced apart to cover the other side of the electrode assembly.
[0020] The first adhesive portion or the second adhesive portion can cover at least 15% of the one side or the other side of the electrode assembly, respectively.
[0021] The adhesive portion may further include an additional adhesive member disposed between the inner member and the outer member to bond the inner member and the outer member.
[0022] According to a preferred embodiment of the present invention, the edge portion of an electrode assembly can be pressurized by an adhesive portion comprising an inner member that contracts at high temperatures and an outer member that expands, without artificially pressurizing the electrode and the separator. As a result, the adhesion of the edge portion of the separator does not weaken and gaps between electrodes do not occur, thereby reducing or eliminating the occurrence of lithium precipitation at the edge portion of the electrode assembly. Furthermore, the degree of bonding between the electrode and the separator does not weaken even when a high-temperature process is performed, which can increase the versatility of cell use.
[0023] In addition to this, the configurations according to the preferred embodiments of the present invention may include effects that are easily predictable by those skilled in the art.
[0024] 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.
[0025] FIG. 1 is a perspective view of a battery cell according to one embodiment of the present invention.
[0026] FIG. 2 is a front view of a battery cell according to one embodiment of the present invention.
[0027] FIG. 3 is a front view of a first adhesive portion according to one embodiment of the present invention.
[0028] FIG. 4 is a front view of a first adhesive portion according to another embodiment of the present invention.
[0029] Figure 5 is a drawing showing the deformed appearance when heat is applied to the adhesive part shown in Figure 3 or Figure 4.
[0030] FIG. 6 is a perspective view of a battery cell according to another embodiment of the present invention.
[0031] Hereinafter, preferred embodiments of the present invention are described in detail with reference to the attached drawings so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.
[0032] In order to clearly explain the present invention, detailed descriptions of related prior art that are irrelevant to the explanation or that may unnecessarily obscure the essence of the invention have been omitted. Furthermore, when assigning reference numerals to the components of each drawing in this specification, identical or similar reference numerals are assigned to identical or similar components throughout the entire specification.
[0033] Furthermore, 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 invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention.
[0034] FIG. 1 is a perspective view of a battery cell (BC) according to one embodiment of the present invention. FIG. 2 is a front view of a battery cell (BC) according to one embodiment of the present invention.
[0035] Referring to FIGS. 1 and 2, the battery cell (BC) of the present invention may include an electrode assembly (1) and an adhesive portion (2). The electrode assembly (1) may alternately have an electrode (10) and a separator (11). More specifically, a positive electrode active material slurry is applied to a positive electrode current collector and a negative electrode active material slurry is applied to a negative electrode current collector to manufacture a positive electrode (100) and a negative electrode (101), respectively, and an electrode assembly (1) of a predetermined shape can be formed by stacking them on both sides of a separator (11).
[0036] The electrode assembly (1) can be a stack type, a jelly roll type, a stack and folding type, etc., and the type of electrode assembly (1) is not limited.
[0037] The adhesive portion (2) can be attached to the electrode assembly (1) to fix the electrode (10) and the separator (11). The adhesive portion (2) may include a first adhesive portion (20) covering one side of the electrode assembly (1) and a second adhesive portion (21) covering the other side of the electrode assembly (1) facing the one side. In one embodiment, the first adhesive portion (20) and the second adhesive portion (21) may have symmetrical shapes.
[0038] The first adhesive part (20) or the second adhesive part (21) can each cover at least 15% of one side or the other side of the electrode assembly (1). For example, the first adhesive part (20) can cover at least 15% of one side of the electrode assembly (1), and the second adhesive part (21) can cover at least 15% of the other side of the electrode assembly (1).
[0039] Accordingly, both sides (upper or lower surface) of the electrode assembly (1) can be sufficiently pressed by the first adhesive part (20) or the second adhesive part (21). As a result, no gaps are created between the electrodes (10), so the occurrence of lithium precipitation at the edges of the electrode assembly (1) can be reduced or eliminated.
[0040] The adhesive portion (2) may include an inner member (200) disposed on the inside and shrinking when heat is applied, and an outer member (201) disposed on the outside and expanding when heat is applied. Each of the first adhesive portion (20) and the second adhesive portion (21) may include an inner member (200) and an outer member (201). The inner member (200) may come into direct contact with the electrode assembly (1), and the outer member (201) may cover the inner member (200) from the outside of the inner member (200).
[0041] The inner member (200) may include a polymer material. In one embodiment, the inner member (200) may include at least one of linear low-density polyethylene (LLDPE) or ethylene vinyl acetate (EVA). The outer member (201) may include a metallic material. In one embodiment, the outer member (201) may include at least one of aluminum or copper. The adhesive portion (2) of the present invention may be bent into an arch shape so that when heat is applied, the inner member (200) contracts and the outer member (201) expands to press against both sides (upper and / or lower surfaces) of the electrode assembly (1).
[0042] FIG. 3 is a front view of a first adhesive part (20) according to an embodiment of the present invention. In FIG. 3, the first adhesive part (20) is described primarily for convenience, but the description of the first adhesive part (20) can be applied equally to the second adhesive part (21).
[0043] Referring to FIGS. 2 and 3, the inner member (200) and the outer member (201) may each include a first part (P1_200, P1_201), a second part (P2_200, P2_201), and a third part (P3_200, P3_201). That is, the inner member (200) may include a first part (P1_200), a second part (P2_200), and a third part (P3_200), and the outer member (201) may include a first part (P1_201), a second part (P2_201), and a third part (P3_201).
[0044] The first part (P1_200, P1_201) may cover the side of the electrode assembly (1). The first part (P1_200, P1_201) may be a part that extends along the stacking direction of the electrode (10) and the separator (11). The second part (P2_200, P2_201) may be connected to one end of the first part (P1_200, P1_201) and may be adhered to the separator (or outermost separator) defining one side of the electrode assembly (1). The second part (P2_200, P2_201) may be a part that presses the upper surface of the electrode assembly (1). The third part (P3_200, P3_201) may be connected to the other end of the first part (P1_200, P1_201) and may be attached to a separator (or outermost separator) defining the other side of the electrode assembly (1). The third part (P3_200, P3_201) may be a part that presses the lower surface of the electrode assembly (1).
[0045] The outer member (201) can cover the inner member (200). The outer member (201) can cover at least a portion of the second part (P2_200) and the third part (P3_200) of the inner member (200). In one embodiment, the outer member (201) can cover the entire inner member (200). For example, the end of the second part (P2_201) of the outer member (201) and the end of the second part (P2_200) of the inner member (200) may be aligned, and the end of the third part (P3_201) of the outer member (201) and the end of the third part (P3_200) of the inner member (200) may be aligned.
[0046] The adhesive portion (2, the first adhesive portion (20) in FIG. 3) may further include an additional adhesive member (202) disposed between the inner member (200) and the outer member (201) to bond the inner member (200) and the outer member (201).
[0047] FIG. 4 is a front view of a first adhesive portion (20a) according to another embodiment of the present invention. In FIG. 4, the first adhesive portion (20A) is described primarily for convenience, but the description of the first adhesive portion (20a) can be applied equally to the second adhesive portion.
[0048] Referring to FIGS. 2 and FIGS. 4, the inner member (200) may include a first part (P1_200), a second part (P2_200), and a third part (P3_200), and the outer member (201a) may include a first part (P1_201a), a second part (P2_201a), and a third part (P3_201a).
[0049] The first part (P1_200, P1_201a) may cover the side of the electrode assembly (1). The first part (P1_200, P1_201a) may be a part that extends along the stacking direction of the electrode (10) and the separator (11). The second part (P2_200, P2_201a) may be connected to one end of the first part (P1_200, P1_201a) and may be adhered to the separator (or outermost separator) defining one side of the electrode assembly (1). The second part (P2_200, P2_201a) may be a part that presses the upper surface of the electrode assembly (1). The third part (P3_200, P3_201a) may be connected to the other end of the first part (P1_200, P1_201a) and may be attached to a separator (or outermost separator) defining the other side of the electrode assembly (1). The third part (P3_200, P3_201a) may be a part that presses the lower surface of the electrode assembly (1).
[0050] The outer member (201a) can cover the inner member (200). The outer member (201a) can cover at least a portion of the second part (P2_200) and the third part (P3_200) of the inner member (200).
[0051] In this embodiment, the outer member (201a) may cover only a portion of the inner member (200). For example, the end of the second part (P2_201a) of the outer member (201a) may be located further outward than the end of the second part (P2_200) of the inner member (200), and the end of the third part (P3_201a) of the outer member (201a) may be located further outward than the end of the third part (P3_200) of the inner member (200). As the end of the outer member (201a) is located further outward than the end of the inner member (200), the problem of the outer member (201a) expanding and coming into contact with the electrode assembly (1) can be prevented, and damage to the electrode assembly (1) can be prevented.
[0052] The adhesive portion (2, the first adhesive portion (20a) in FIG. 4) may further include an additional adhesive member (202a) disposed between the inner member (200) and the outer member (201a) to bond the inner member (200) and the outer member (201a).
[0053] FIG. 5 is a drawing showing the deformed appearance of the adhesive portion shown in FIG. 3 or FIG. 4 when heat is applied. For convenience of explanation, additional adhesive members (202, 202a, see FIG. 3 or FIG. 4) are omitted in FIG. 5. Also, for convenience of explanation, the deformed adhesive portion is labeled '2-1'.
[0054] Referring to FIGS. 2 and FIGS. 5, when heat is applied, the inner member (200-1) of the adhesive part (2-1) may contract and the outer member (201-1) may expand. As a result, the end of the adhesive part (2-1) may be bent, and the bent adhesive part (2-1) may press against both sides (upper and lower surfaces) of the electrode assembly (1). FIG. 5 illustrates an exemplary deformed adhesive part (2-1) when heat is applied, but the shape is not limited to the above shape as long as the adhesive part (2-1) presses against both sides of the electrode assembly (1).
[0055] According to the present invention, even without artificially pressurizing the electrode (10) and the separator (11), the edge portion of the electrode assembly (1) can be pressed by an adhesive portion (2-1) comprising an inner member (200-1) that shrinks at high temperatures and an outer member (201-1) that expands. As a result, the adhesion of the edge portion of the separator (11) does not weaken and no gaps are created between the electrodes (10), thereby reducing or eliminating the occurrence of lithium precipitation at the edge portion of the electrode assembly (1). Furthermore, even when a high-temperature process is performed, the degree of bonding between the electrode (10) and the separator (11) does not weaken, thereby increasing the versatility of cell use.
[0056] FIG. 6 is a perspective view of a battery cell (BC) according to another embodiment of the present invention. In describing FIG. 6, reference is made to FIG. 1 and FIG. 2, and descriptions of the same reference numerals are omitted.
[0057] Referring to FIGS. 2 and FIGS. 6, the first adhesive portion (20b) and the second adhesive portion (21b) may be provided in multiple numbers. The multiple first adhesive portions (20b) may be spaced apart from each other to cover one side of the electrode assembly (1), and the multiple second adhesive portions (21b) may be spaced apart from each other to cover the other side of the electrode assembly (1). Each of the multiple first adhesive portions (20b) and the multiple second adhesive portions (21b) may be spaced apart and arranged along the extension direction of the electrode assembly (1).
[0058] A plurality of first adhesive portions (20b) can cover at least 15% of one side of the electrode assembly (1), and a plurality of second adhesive portions (21b) can cover at least 15% of the other side of the electrode assembly (1). In FIG. 6, three regularly spaced first adhesive portions (20b) and three second adhesive portions (21b) are illustrated as examples, but the number and spacing / rules of the first adhesive portions (20b) and second adhesive portions (21b) are not limited to the above example as long as each first adhesive portion (20) or second adhesive portion (21) covers at least 15% of one side or the other side of the electrode assembly (1). As the first adhesive portions (20b) and the second adhesive portions (21b) are provided in multiple numbers, they can be freely arranged according to the shape and design purpose of the secondary battery, thereby optimizing the design and reducing the amount of material required to manufacture the adhesive portions, which can reduce production costs.
[0059] Although the present invention has been described above by limited embodiments and drawings, the present invention is not limited thereto, and various implementations 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.
[0060] [Explanation of the symbol]
[0061] BC, BCb: battery cell
[0062] 1: Electrode assembly
[0063] 10: Electrode
[0064] 100: Anode
[0065] 101: Cathode
[0066] 11: Separator
[0067] 2, 2-1: Adhesive part
[0068] 20, 20a, 20b: First adhesive part
[0069] 200, 200-1: Inner absence
[0070] P1_200: First part of the inner member
[0071] P2_200: Second part of the inner member
[0072] P3_200: Third part of the inner member
[0073] 201, 201a, 201-1: Outer missing
[0074] P1_201, P1_201a: First part of the outer member
[0075] P2_201, P2_201a: Second part of the outer member
[0076] P3_201, P3_201a: Third part of the outer member
[0077] 202, 202a: Additional adhesive member
[0078] 21, 21b: Second adhesive part
Claims
1. An electrode assembly having alternating electrodes and separators; and It includes an adhesive portion attached to the electrode assembly to fix the electrode and the separator, The above adhesive part is, An inner member positioned on the inside and shrinking when heat is applied; and A battery cell comprising an outer member positioned on the outside and expanding when heat is applied.
2. In Paragraph 1, Each of the above inner member and outer member is, A first part covering the side of the electrode assembly; A second portion connected to one end of the first portion and adhered to a separator defining one surface of the electrode assembly; and A battery cell comprising a third part connected to the other end of the first part and adhered to a separator defining the other surface of the electrode assembly.
3. In Paragraph 2, The above outer member is a battery cell that covers at least a portion of the second and third portions of the above inner member.
4. In Paragraph 2, The end of the second part of the outer member and the end of the second part of the inner member are aligned, The end of the third part of the outer member and the end of the third part of the inner member are aligned battery cells.
5. In Paragraph 2, The end of the second part of the outer member is located further outward than the end of the second part of the inner member, and The end of the third part of the outer member is a battery cell located outside the end of the third part of the inner member.
6. In Paragraph 1, The above inner member is a battery cell containing a polymer material.
7. In Paragraph 1, The above outer member is a battery cell comprising a metal material.
8. In Paragraph 1, The inner member comprises at least one of linear low-density polyethylene (LLDPE) or ethylene vinyl acetate (EVA), and The above outer member is a battery cell comprising at least one of aluminum or copper.
9. In Paragraph 1, A battery cell in which, when heat is applied, the inner member contracts and the outer member expands, so that the adhesive portion is bent into an arch shape to press both sides of the electrode assembly.
10. In Paragraph 1, A battery cell comprising a first adhesive portion covering one side of the electrode assembly and a second adhesive portion covering the other side of the electrode assembly facing the one side.
11. In Paragraph 10, The first adhesive part and the second adhesive part are provided in a plurality of numbers, A battery cell in which a plurality of first adhesive portions are spaced apart to cover one side of the electrode assembly, and a plurality of second adhesive portions are spaced apart to cover the other side of the electrode assembly.
12. In Paragraph 10, A battery cell in which the first adhesive portion or the second adhesive portion each covers at least 15% of the one side or the other side of the electrode assembly.
13. In Paragraph 1, A battery cell comprising an additional adhesive member disposed between the inner member and the outer member to bond the inner member and the outer member.