Side sealing device for stack-type electrode assembly

Abstract

The present invention relates to a side sealing device for a stack-type electrode assembly and, more specifically, to a side sealing device for sealing a side surface of a stack-type electrode assembly having a separator interposed between a first electrode and a second electrode. The side sealing device for a stack-type electrode assembly comprises: a first sealing tool positioned on one side surface of the stack-type electrode assembly; and a second sealing tool positioned on the other side surface of the stack-type electrode assembly, wherein at least one of the first sealing tool and the second sealing tool has a protruding part and a recessed part which are provided on an inner surface thereof facing a side surface of the stack-type electrode assembly.

Description

Side sealing device of stacked electrode assembly

[0001] This application claims the benefit of priority to Korean Patent Application No. 10-2024-0109272, filed August 14, 2024, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a side sealing device for a stacked electrode assembly, and more particularly, to a side sealing device for a stacked electrode assembly for sealing both sides of a stacked electrode assembly in which a first electrode, a separator, and a second electrode are alternately stacked.

[0003]

[0004] As technological development and demand for mobile devices increase, rechargeable secondary batteries are increasingly being used as energy sources for a variety of mobile devices. Secondary batteries are also attracting attention as an energy source for electric and hybrid electric vehicles, offering an alternative to conventional gasoline and diesel vehicles that rely on fossil fuels.

[0005] Secondary batteries are classified into cylindrical and prismatic batteries, in which the electrode assembly is built into a cylindrical or prismatic metal can, and pouch-type batteries, in which the electrode assembly is built into a pouch-type case made of aluminum laminate sheet, depending on the shape of the battery case.

[0006] The typical pouch-type secondary battery manufacturing process includes storing the electrode assembly in a battery case pocket made of a laminated sheet, injecting an electrolyte inside the battery case, sealing it, and activating the battery case.

[0007] A stacked electrode assembly, which is a type of electrode assembly, is stacked so that a separator is interposed between the positive and negative electrodes. As illustrated in Fig. 1, in the case of a stacked electrode assembly, a separator (13) is disposed between the first electrode (11) and the second electrode (12), thereby preventing electrical short circuits caused by physical contact between the first electrode (11) and the second electrode (12).

[0008] At this time, the separator (13) is generally manufactured to have a wider width in both the horizontal and vertical directions than the first electrode (11) and the second electrode (12).

[0009] The stacked electrode assembly laminated in this manner is completed as a single secondary battery through subsequent processes such as heating and pressing in the height direction, lateral heating, and packaging.

[0010] In this regard, a side sealing device that heats the side of an electrode assembly (10) to adhesively seal the separators together is known. That is, as illustrated in Fig. 2, a pair of heating members (1) are positioned on both sides of the electrode assembly (10) to adhesively seal the separators (13) extending outside the first electrode (11) and the second electrode (12).

[0011] However, although the side of the electrode assembly (10) can be sealed by a pair of heating elements (1), there is a problem in that it is difficult for the electrolyte to permeate into the first electrode (11), the second electrode (12), and the separator (13).

[0012]

[0013] (Prior art literature)

[0014] (Patent Document 1) Korean Patent Publication No. 10-2023-0171902

[0015] In order to solve the above problems, the present invention aims to provide a side sealing device for a stacked electrode assembly that has excellent electrolyte impregnation properties while fixing the end of a separator constituting the stacked electrode assembly.

[0016]

[0017] In order to achieve the above object, a side sealing device of a stacked electrode assembly according to the present invention is a side sealing device that seals a side of a stacked electrode assembly (10) in which a separator (13) is interposed between a first electrode (11) and a second electrode (12), and comprises: a first sealing tool (100) positioned on one side of the stacked electrode assembly (10); and a second sealing tool (200) positioned on the other side of the stacked electrode assembly (10); wherein at least one of the first sealing tool (100) and the second sealing tool (200) is characterized in that a protrusion and a depression are provided on an inner surface facing the side of the stacked electrode assembly (10).

[0018] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the first sealing tool (100) and the second sealing tool (200) are characterized in that protrusions and depressions are provided on the inner surfaces thereof.

[0019] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, when the first sealing tool (100) and the second sealing tool (200) are positioned on both sides of the stacked electrode assembly (10), the inner side of the first sealing tool (100) and the second sealing tool (200) is characterized in that it has an area that can completely cover both sides of the stacked electrode assembly (10).

[0020] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the first sealing tool (100) is provided with a plurality of first protrusions (110) having a bar shape that protrudes continuously along the height direction, and one or more first depressions (120) located between the first protrusions (110).

[0021] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the first sealing tool (100) is provided with a plurality of first protrusions (110) having a cylindrical shape that protrude toward the side of the stacked electrode assembly (10) at a predetermined interval along the height direction and the length direction, and a first recessed portion (120) positioned between the first protrusions (110).

[0022] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the first sealing tool (100) is provided with a plurality of first protrusions (110) having a cone shape that protrude toward the side of the stacked electrode assembly (10) at a predetermined interval along the height direction and the length direction, and a first recessed portion (120) positioned between the first protrusions (110).

[0023] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the first recessed portion (120) is characterized in that it is positioned in a shape that surrounds the first protruding portion (110).

[0024] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the second sealing tool (200) is provided with a plurality of second protrusions (210) having a bar shape that protrudes continuously along the height direction, and one or more second recessed portions (220) located between the second protrusions (210).

[0025] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the second sealing tool (200) is provided with a plurality of second protrusions (210) having a cylindrical shape that protrude toward the side of the stacked electrode assembly (10) at a predetermined interval along the height direction and the length direction, and a second recessed portion (220) positioned between the second protrusions (210).

[0026] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the inner surface of the second sealing tool (200) is provided with a plurality of second protrusions (210) having a cone shape that protrude toward the side of the stacked electrode assembly (10) at a predetermined interval along the height direction and the length direction, and a second recessed portion (220) positioned between the second protrusions (210).

[0027] In addition, in the side sealing device of the stacked electrode assembly according to the present invention, the second recessed portion (220) is characterized in that it is positioned in a shape that surrounds the second protruding portion (210).

[0028]

[0029] According to the side sealing device of the stacked electrode assembly according to the present invention, a pair of sealing tools positioned on the side of the stacked electrode assembly are provided with both a protrusion and a depression, so that a sealing portion and an unsealed portion are formed together on the side of the electrode assembly, which can contribute to manufacturing a stacked electrode assembly having excellent electrolyte impregnation properties while preventing the end of the separator constituting the stacked electrode assembly from being peeled off.

[0030]

[0031] Figure 1 is a conceptual diagram of a stacked electrode assembly.

[0032] Figure 2 is a conceptual diagram of a sealing device for a stacked electrode assembly according to the prior art.

[0033] Figure 3 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to the first embodiment of the present invention.

[0034] Figure 4 is an enlarged view of the side sealing device shown in Figure 3.

[0035] Figure 5 is a drawing of the side sealing device shown in Figure 3 viewed from above.

[0036] Figure 6 is a front view of the side sealing device illustrated in Figure 3.

[0037] FIG. 7 is a drawing for explaining a stacked electrode assembly after sealing using the side sealing device illustrated in FIG. 3.

[0038] Figure 8 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to a second embodiment of the present invention.

[0039] FIG. 9 is a drawing for explaining a stacked electrode assembly after sealing using the side sealing device illustrated in FIG. 8.

[0040] Fig. 10 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to a third embodiment of the present invention.

[0041]

[0042] Hereinafter, with reference to the attached drawings, embodiments of the present invention will be described in detail, so that those skilled in the art can easily implement the present invention. However, when describing the operating principles of preferred embodiments of the present invention in detail, if a detailed description of a related known function or configuration is judged to unnecessarily obscure the gist of the present invention, such detailed description will be omitted.

[0043] Additionally, the same drawing reference numerals are used for parts with similar functions and actions throughout the drawings. Throughout the specification, when a part is said to be connected to another part, this includes not only direct connections but also indirect connections with other elements intervening. Furthermore, inclusion of a component does not exclude other components unless specifically stated otherwise, but rather implies the inclusion of additional components.

[0044]

[0045] Hereinafter, a side sealing device of a stacked electrode assembly according to the present invention will be described.

[0046] FIG. 3 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to a first embodiment of the present invention, and FIG. 4 is an enlarged view of the side sealing device illustrated in FIG. 3. In addition, FIG. 5 is a view of the side sealing device illustrated in FIG. 3 as viewed from above, and FIG. 6 is a view of the side sealing device illustrated in FIG. 3 as viewed from the front.

[0047] Referring to FIG. 1 and FIGS. 3 to 5 together, a side sealing device of a stacked electrode assembly according to the first embodiment of the present invention may be configured to include a first sealing tool (100) and a second sealing tool (200) positioned on each side of the electrode assembly (10).

[0048] First, the electrode assembly (10) is a stack-type electrode assembly in which a separator (13) is arranged in a zigzag shape between the first electrode (11) and the second electrode (13).

[0049] For example, the stacked electrode assembly may have a shape in which a separator (13) is positioned at the bottom, followed by a first electrode (11), which is a cathode, a separator (13), and a second electrode (12), which is an anode, repeatedly arranged.

[0050] As another example, the stacked electrode assembly may be formed by stacking multiple monocells in the order of a separator (13), a first electrode (11) which is a cathode, a separator (13), and a second electrode (12) which is an anode from the bottom, and a half-cell in which a separator (13), a first electrode (11), and a separator (13) are stacked may be positioned at the top, but is not necessarily limited thereto.

[0051] The first electrode (11), which is a negative electrode, is composed of a negative electrode current collector and a negative electrode active material applied to the lower and upper surfaces of the negative electrode current collector. A conductive material and a binder may be additionally mixed into the negative electrode active material and coated on the negative electrode current collector.

[0052] The second electrode (12), which is a positive electrode, is composed of a positive electrode current collector and a positive electrode active material applied to the upper and lower surfaces of the positive electrode current collector. A conductive material and a binder may be mixed with the positive electrode active material, and a filler may be further added as needed.

[0053] The separator (13) prevents a short between the first electrode (11) and the second electrode (12) described above and only allows the movement of lithium ions. The material of the separator is preferably one selected from among polyethylene, polypropylene, a polyethylene / polypropylene double layer, a polyethylene / polypropylene / polyethylene triple layer, a polypropylene / polyethylene / polypropylene triple layer, and an organic fiber filter paper, but is not limited thereto.

[0054] Since the first electrode (11), separator (13), and second electrode (12) described above correspond to known technologies, a more detailed description will be omitted.

[0055] The first sealing tool (100) is located on one side of the stacked electrode assembly (10), and is provided with a first protrusion (110), a first recessed portion (120), and a first heating means (130). Specifically, the outer shape is roughly an elongated hexahedron, and the inner side, that is, the side facing the one side of the stacked electrode assembly (10), is provided with a first protrusion (110) and a first recessed portion (120).

[0056] In the side sealing step, the first protrusion (110) is heated by the first heating means (130) and is a part that performs sealing by coming into close contact with one side of the stacked electrode assembly (10). It is a bar shape that protrudes continuously along the height direction (Y-axis direction) of the first sealing tool (100), and it is preferable that a plurality of such first protrusions (110) are provided at a predetermined interval along the length direction (Z-axis direction) of the first sealing tool (100).

[0057] Here, the first heating means (130) is not particularly limited as long as it can heat the first sealing tool (100), but may be, for example, a heating coil and may be stored inside the first sealing tool (100).

[0058] The first recessed portion (120) is positioned between the first protrusions (110) and has a bar shape that is continuously recessed along the height direction (Y-axis direction) of the first sealing tool (100). It is preferable that a plurality of such first recessed portions (120) are provided at a predetermined interval along the length direction (Z-axis direction) of the first sealing tool (100).

[0059] During the side sealing step, unlike the first protrusion (110), the first recessed portion (120) does not come into close contact with one side of the stacked electrode assembly (10) due to the recessed portion, and therefore, the portion facing the first recessed portion (120) is not sealed and can thus function as a passage through which the electrolyte moves.

[0060] The second sealing tool (200) is located on the other side of the stacked electrode assembly (10), and is provided with a second protrusion (210), a second recessed portion (220), and a second heating means (230). Specifically, the outer shape is roughly an elongated hexahedron, and the inner side, that is, the side facing the other side of the stacked electrode assembly (10), is provided with a second protrusion (210) and a second recessed portion (220).

[0061] In the side sealing step, the second protrusion (210) is heated by the second heating means (230) and is a part that performs sealing by coming into close contact with the other side of the stacked electrode assembly (10). It is a bar shape that protrudes continuously along the height direction (Y-axis direction) of the second sealing tool (200), and it is preferable that a plurality of such second protrusions (210) are provided at a predetermined interval along the length direction (Z-axis direction) of the second sealing tool (200).

[0062] Here, the second heating means (230) is not particularly limited as long as it can heat the second sealing tool (200), but may be, for example, a heating coil and may be stored inside the second sealing tool (200).

[0063] The second recessed portion (220) is positioned between the second protrusions (210) and has a bar shape that is continuously recessed along the height direction (Y-axis direction) of the second sealing tool (200). It is preferable that a plurality of such second recessed portions (220) are provided at a predetermined interval along the length direction (Z-axis direction) of the second sealing tool (200).

[0064] During the side sealing step, the second recessed portion (220) is not in close contact with the other side of the stacked electrode assembly (10) due to the recessed portion, unlike the second protrusion (210), and therefore, the portion facing the second recessed portion (220) is not sealed and can thus function as a passage through which the electrolyte moves.

[0065] Meanwhile, it is preferable that the inner surfaces of the first sealing tool (100) and the second sealing tool (200), that is, the surface provided with the first protrusion (110) and the first recessed portion (120) in the case of the first sealing tool (100), and the surface provided with the second protrusion (210) and the second recessed portion (220) in the case of the second sealing tool (200), have an area that can completely cover each side of the stacked electrode assembly (10).

[0066] For example, as shown in FIGS. 5 and 6, it is preferable that the first sealing tool height (D1) and the second sealing tool height (D2) be greater than or equal to the electrode assembly thickness (D3), and that the first sealing tool length (L1) and the second sealing tool length (L2) be greater than or equal to the electrode assembly length (L3).

[0067] FIG. 7 is a drawing for explaining a stacked electrode assembly after sealing using the side sealing device illustrated in FIG. 3.

[0068] When the side of the stacked electrode assembly (10) is sealed using the side sealing device according to the first embodiment described with reference to FIGS. 3 to 6, as shown in FIG. 7, the portions that are in close contact with the first protrusion (110) and the second protrusion (210) respectively have the separators melted to form a sealing portion (S). However, the portions that faced the first recessed portion (120) and the second recessed portion (220) remain as unsealed portions (NS) because sufficient heat is not applied to melt the separators.

[0069] Therefore, when the stack-type electrode assembly (10) is stored in a cell case (not shown) and an electrolyte is injected, the electrolyte can easily move through the unsealed portion (NS) of the stack-type electrode assembly (10), so that the electrode assembly can be sufficiently impregnated.

[0070] Meanwhile, although not described in the drawings, it is obvious that the vertical sealing process of the stacked electrode assembly can be performed through a sealing device (not shown) that heats and pressurizes the upper surface of the stacked electrode assembly, and side sealing can be performed after the vertical sealing, or these can be performed simultaneously.

[0071] FIG. 8 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to a second embodiment of the present invention, and FIG. 9 is a drawing for explaining a stacked electrode assembly after sealing using the side sealing device illustrated in FIG. 8.

[0072] The side sealing device of the stacked electrode assembly according to the second embodiment of the present invention is identical to the side sealing device of the first embodiment except for the shapes of the protrusions and depressions, so only the different configurations will be described below.

[0073] In the side sealing device of the stacked electrode assembly according to the second embodiment, a plurality of first protrusions (110) positioned on the inner surface of the first sealing tool (100) may be provided at predetermined intervals along the height direction (Y-axis direction) and the length direction (Z-axis direction).

[0074] Here, each of the first protrusions (110) has a cylindrical shape that protrudes in a direction toward one side of the stacked electrode assembly (10).

[0075] And the first depression (120) is shaped to surround the first protrusion (110), that is, it is the remaining part excluding the first protrusion (110).

[0076] In addition, a plurality of second protrusions (210) located on the inner surface of the second sealing tool (200) may be provided at predetermined intervals along the height direction (Y-axis direction) and the length direction (Z-axis direction).

[0077] Like the first protrusion (110), each of the second protrusions (210) has a cylindrical shape that protrudes in a direction toward the other side of the stacked electrode assembly (10).

[0078] And the second depression (220) is shaped to surround the second protrusion (210), that is, it is the remaining part excluding the second protrusion (210).

[0079] When the side of the stacked electrode assembly (10) is sealed using the side sealing device according to the second embodiment, as illustrated in FIG. 9, the portions that are in close contact with the first protrusion (110) and the second protrusion (210) are formed by melting the separators to form a sealing portion (S). However, the portions that face the first recessed portion (120) and the second recessed portion (220) remain as unsealed portions (NS) because sufficient heat is not applied to melt the separators.

[0080] In particular, since the first protrusion (110) and the second protrusion (210) are positioned at a predetermined interval along the height direction (Y-axis direction) and length direction (Z-axis direction) of the sealing tool, the electrolyte injected into the cell case (not shown) can move through multiple paths, making the impregnation of the electrode assembly much more advantageous.

[0081] Fig. 10 is a conceptual diagram of a side sealing device of a stacked electrode assembly according to a third embodiment of the present invention.

[0082] The side sealing device of the stacked electrode assembly according to the third embodiment of the present invention is identical to the side sealing device of the second embodiment except for the shapes of the protrusions and depressions, so only the different configurations will be described below.

[0083] In the side sealing device of the stacked electrode assembly according to the third embodiment, each of the first protrusions (110) located on the inner surface of the first sealing tool (100) has a cone-shaped shape that protrudes in a direction toward one side of the stacked electrode assembly (10).

[0084] As with the first protrusion (110), each of the second protrusions (210) has a cone-shaped shape that protrudes in the direction toward the other side of the stacked electrode assembly (10).

[0085] A side sealing method of a stacked electrode assembly according to the present invention comprises a first step of preparing a stacked electrode assembly, and a second step of positioning a pair of sealing tools on both sides of the prepared stacked electrode assembly to seal both sides.

[0086] In the second step, a pair of sealing tools can be pressed against both sides of the stacked electrode assembly while being heated to a certain temperature, and it is also possible to heat the sealing tools to a certain temperature after pressing a pair of sealing tools against both sides of the stacked electrode assembly.

[0087] Additionally, a step of heating and pressurizing the upper surface of the stacked electrode assembly may be performed before the second step, simultaneously with the second step, or after the second step.

[0088] Meanwhile, the stacked electrode assembly obtained through the aforementioned process is stored in a battery case having a pocket section, and then a pouch-type battery cell is manufactured through processes such as electrolyte injection and charge / discharge.

[0089]

[0090] As described above, specific parts of the present invention have been described in detail. To those skilled in the art, such specific descriptions are merely preferred embodiments, and the scope of the present invention is not limited thereby. It is obvious to those skilled in the art that various changes and modifications are possible within the scope and technical idea of ​​the present invention, and it is natural that such changes and modifications fall within the scope of the appended patent claims.

[0091] (Explanation of symbols)

[0092] 10: Stacked electrode assembly

[0093] 11: First electrode 12: Second electrode

[0094] 13: Membrane

[0095] 100: 1st sealing tool

[0096] 110: First protrusion

[0097] 120: First depression

[0098] 130: First heating means

[0099] 200: Second sealing tool

[0100] 210: Second protrusion

[0101] 220: Second depression

[0102] 230: Second heating means

[0103] S: Sealing part

[0104] NS: Mishilling Department

[0105] D1: Height of the first sealing tool

[0106] D2: Second sealing tool height

[0107] D3: Electrode assembly thickness

[0108] L1: Length of the first sealing tool

[0109] L2: Second sealing tool length

[0110] L3: Electrode assembly length

Claims

1. A side sealing device for sealing the side of a stacked electrode assembly with a separator interposed between the first electrode and the second electrode, A first sealing tool located on one side of the stacked electrode assembly; and A second sealing tool positioned on the other side of the stacked electrode assembly; A side sealing device for a stacked electrode assembly, characterized in that at least one of the first sealing tool and the second sealing tool has a protrusion and a depression on the inner surface facing the side of the stacked electrode assembly.

2. In paragraph 1, A side sealing device for a stacked electrode assembly, characterized in that the inner surfaces of the first sealing tool and the second sealing tool are provided with protrusions and depressions.

3. In paragraph 2, A side sealing device for a stacked electrode assembly, characterized in that when the first sealing tool and the second sealing tool are positioned on both sides of the stacked electrode assembly, the inner surfaces of the first sealing tool and the second sealing tool have an area that can completely cover both sides of the stacked electrode assembly.

4. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the first sealing tool is provided with a plurality of first protrusions having a bar shape that protrudes continuously along the height direction, and at least one first depression located between the first protrusions.

5. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the first sealing tool is provided with a plurality of first protrusions having a cylindrical shape protruding toward the side of the stacked electrode assembly at a predetermined interval along the height direction and the length direction, and a first recessed portion positioned between the first protrusions.

6. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the first sealing tool is provided with a plurality of first protrusions having a cone shape protruding toward the side of the stacked electrode assembly at a predetermined interval along the height direction and the length direction, and a first recessed portion located between the first protrusions.

7. In paragraph 5 or 6, A side sealing device of a stacked electrode assembly, characterized in that the first recessed portion is positioned in a shape that surrounds the first protrusion.

8. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the second sealing tool is provided with a plurality of second protrusions having a bar shape that protrudes continuously in the height direction, and at least one second recessed portion located between the second protrusions.

9. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the second sealing tool is provided with a plurality of second protrusions having a cylindrical shape protruding toward the side of the stacked electrode assembly at a predetermined interval along the height direction and the length direction, and a second recessed portion positioned between the second protrusions.

10. In paragraph 3, A side sealing device for a stacked electrode assembly, characterized in that the inner surface of the second sealing tool is provided with a plurality of second protrusions having a conical shape that protrude toward the side of the stacked electrode assembly at a predetermined interval along the height direction and the length direction, and a second recessed portion located between the second protrusions.

11. In paragraph 9 or 10, A side sealing device of a stacked electrode assembly, characterized in that the second recessed portion is positioned in a shape that surrounds the second protrusion.

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