Secondary battery sealing device

Abstract

The secondary battery sealing device according to an embodiment of the present invention includes a pair of sealing blocks provided to pressurize a pouch and a bonding target area of a lead film of a mounted battery cell, on which the battery cell is mounted, and a pair of lead blocks provided to cover the mounted leads, on which leads of the battery cell exposed outside the pouch are mounted. At least one of the pair of lead blocks is provided with a recess for accommodating the leads.

Description

Technical Field

[0001] The present invention relates to a secondary battery sealing device capable of minimizing damage to a lead and heat loss of the lead during the sealing process of a pouch-type secondary battery.

[0002] This application claims the benefit of priority based on Korean Patent Application No. 10-2023-0022551 filed on February 21, 2023, and all contents disclosed in the document of the Korean patent application are included as part of this specification.

Background Art

[0003] Secondary batteries can be classified into coin-type secondary batteries, square-type secondary batteries, cylindrical secondary batteries, pouch-type secondary batteries, etc., according to the shape of the battery case.

[0004] In particular, the pouch-type secondary battery has advantages such as a simple structure, a large capacitance per unit volume, low manufacturing costs, a small weight, and easy shape change. Therefore, recently, pouch-type secondary batteries in which an aluminum pouch is packaged around a battery cell in which an electrode and a separator are laminated are widely used.

[0005] The pouch-type secondary battery is formed by performing the steps of slurry mixing, electrode (anode material / cathode material) coating, electrode plate pressing, electrode plate slitting and electrode plate notching / punching, electrode plate drying, electrode plate lamination, electrode plate stacking, pouch packaging, electrolyte injection, formation, and pouch degassing in this order.

[0006] At this time, in the packaging process, an electrode assembly in which electrodes and a separation film are alternately laminated is packaged with a pouch, and when packaging with the pouch, a pair of leads electrically connected to the electrodes of the electrode assembly are exposed to the outside of the pouch. Further, the packaging process includes a sealing process for joining the pouch and the leads via a lead film.

[0007] FIGS. 1 and 2 are diagrams for explaining a conventional secondary battery sealing device and a lead block, FIG. 3 is a diagram for explaining a state in which leads of a battery cell are placed on the lead block shown in FIG. 1, and FIG. 4 is a diagram for explaining the positions of a battery cell, a pair of sealing blocks, and a pair of lead blocks when a sealing process is performed by the conventional secondary battery sealing device shown in FIG. 3.

[0008] Referring to FIGS. 1 to 4, a conventional secondary battery sealing device 1 includes a main body 2, a pair of sealing blocks 10 provided on the main body 2 for joining a sealing target region of a battery cell 3, and a pair of lead blocks 20 provided on each of the pair of sealing blocks 10 on which leads 4 of the battery cell 3 exposed to the outside of the pouch are placed.

[0009] At this time, below the battery cell 3, a first sealing block 12 that supports the lower side of the battery cell 3 and on which the battery cell 3 is placed, and a first lead block 22 provided on the first sealing block 12 on which the lead 4 of the battery cell 3 is placed are positioned. Further, above the battery cell 3, a second sealing block 14 for pressing the battery cell 3 placed on the first sealing block 12, and a second lead block 24 provided on the second sealing block 14 and covering the lead 4 of the battery cell 3 placed on the first block 22 are positioned.

[0010] During the pouch sealing process, using the heat applied to the first sealing block 12 and the second sealing block 14, the sealant applied to the lead film 5 and the pouch (not shown) is melted to seal the lead 4 and the pouch. In the process of sealing the lead 4 and the pouch by the first sealing block 12 and the second sealing block 14, there is a problem that the lead film 5 made of polypropylene material PP (PolyPropylene) cannot be properly melted only by the heat of the first sealing block 12 and the second sealing block 14.

[0011] To solve such a problem, heating members (not shown) are provided not only on the first sealing block 12 and the second sealing block 14 but also on each of the first lead block 22 and the second lead block 24 to apply heat to the first lead block 22 and the second lead block 24. Then, the lead 4 disposed between the first lead block 22 and the second lead block 24 and the lead film connected to the lead 4 will have a certain amount of heat.

[0012] In this state, when the battery cell 3 is pressurized by the first sealing block 12 and the second sealing block 14, the lead film 5 melts well by the first sealing block 12, the second sealing block 14, the first lead block 22, and the second lead block 24, so that the lead 4 and the pouch can be easily sealed.

[0013] On the other hand, when the battery cell 3 is pressurized by the first sealing block 12 and the second sealing block 14, the lead 4 placed on the opposing surface 23 of the first lead block 23 having a flat surface contacts the opposing surface 23 of the first lead block 22 and the opposing surface 25 of the second lead block 24 respectively. At this time, since the opposing surface 23 of the first lead block 22 and the opposing surface 25 of the second lead block 24 have flat surfaces, the contact area with the lead 4 becomes large, and there is a problem that damage such as scratches occurs on the outer surface of the lead 4.

[0014] In order to solve this problem, a method is used such that the first lead block 22 and the second lead block 24 do not come into direct contact with the lead 4, for example, by winding heat insulation tape around each of the first lead block 22 and the second lead block 24.

[0015] However, there is a problem in that a gap g is generated between the first lead block 22 and the second lead block 24 due to the heat insulation tape wound around each of the first lead block 22 and the second lead block 24, and heat loss of the lead 4 occurs due to the lead 4 being exposed to the atmosphere through the gap g.

[0016] In addition, if the first lead block 22 and the second lead block 24 do not come into contact with the lead 4, there is a problem in that the original functions of the first lead block 22 and the second lead block 24 for supporting the lead 4 are reduced.

Summary of the Invention

Problems to be Solved by the Invention

[0017] An object of the present invention is to provide a secondary battery sealing device capable of preventing damage such as scratches on a lead due to contact with a lead block during the sealing process of a secondary battery.

[0018] Another object of the present invention is to provide a secondary battery sealing device capable of preventing heat loss of a lead during the sealing process of a secondary battery.

Means for Solving the Problems

[0019] In order to solve the above-described problems, according to one aspect of the present invention, there is provided a sealing device for joining a pouch of a battery cell and a lead film, including: a pair of sealing blocks provided to pressurize a joining target region of the pouch and the lead film of the placed battery cell; and a pair of lead blocks provided to cover the lead of the battery cell exposed outside the pouch. At least one of the pair of lead blocks is provided with a recess for accommodating the lead, and a secondary battery sealing device is provided.

[0020] Further, the pair of lead blocks may be provided such that regions excluding the recesses contact each other along the edges of the leads.

[0021] Further, the width of the recess may be equal to or greater than the width of the lead.

[0022] Further, the depth of the recess may be equal to or greater than the thickness of the lead.

[0023] Further, the pair of lead blocks may be provided to cover the placed leads when the pair of sealing blocks pressurize the joining target region with the leads placed thereon. As an example, each lead block may be provided on each of the pair of sealing blocks and may be provided to be movable together with each sealing block.

[0024] Further, when the leads are accommodated in the recesses by the pair of lead blocks, the pair of lead blocks may be provided to be in surface contact with each other at least in a partial region along the edges of the leads, excluding the regions where the recesses are formed. In such a structure, when the pair of lead blocks contact each other, the recesses can form an accommodation space for the leads, and by confining heat in the accommodation space, it is possible to prevent the heat of the leads from being lost to the outside.

[0025] Further, the pair of sealing blocks can include a first sealing block that supports the lower side of the battery cell so that the battery cell is placed thereon, and a second sealing block that pressurizes the battery cell placed on the first sealing block by moving toward the first sealing block.

[0026] Further, the pair of lead blocks can include a first lead block coupled to the first sealing block so that the lead is placed thereon when the battery cell is placed on the first sealing block, and a second lead block coupled to the second sealing block and provided so as to cover the lead placed on the first lead block when the second sealing block moves toward the first sealing block.

[0027] Further, the recessed portion can be provided in the first lead block.

[0028] Further, the width of the recessed portion may be equal to or greater than the width of the lead.

[0029] Further, the depth of the recessed portion may be equal to or greater than the thickness of the lead.

[0030] Further, when the lead is covered by the second lead block, the opposing surfaces of the first lead block and the second lead block may be provided to be in surface contact with each other along the edge of the lead, excluding the region where the recessed portion is formed.

[0031] Further, the lead and the lead film exposed on the open side of the recessed portion can be pressurized by the first sealing block and the second sealing block. When the lead is covered by the second lead block, the recessed portion can have a structure in which one surface facing the pouch is open.

[0032] Further, the recessed portion may be provided in each of the first lead block and the second lead block. In such a structure, the total depth of the recessed portion formed in each lead block may be equal to or greater than the thickness of the lead.

Advantages of the Invention

[0033] As described above, the secondary battery sealing device according to an embodiment of the present invention has the following effects.

[0034] During the sealing process of the secondary battery, the lead of the battery cell exposed outside the pouch is inserted into the recessed portion formed in one of the pair of lead blocks and covered by the other lead block. As a result, the portion where the lead is exposed to the atmosphere is minimized, so that the heat loss of the lead can be minimized.

[0035] In addition, after the lead is inserted into the recessed portion of one of the lead blocks, it is covered by the other lead block, so that the contact area with the pair of lead blocks can be minimized, and appearance damage such as scratches on the lead can be reduced by the pair of lead blocks.

[0036] In particular, since damage such as scratches does not occur on the appearance of the lead, the appearance defect of the lead can be improved.

Brief Description of the Drawings

[0037]

Figure 1

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DETAILED DESCRIPTION OF THE INVENTION

[0038] Hereinafter, a secondary battery sealing device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

[0039] Also, for the same or corresponding components regardless of the reference numerals, the same or similar reference numerals are attached, and duplicate explanations thereof are omitted. For the convenience of explanation, the sizes and shapes of the respective components shown may be exaggerated or reduced.

[0040] FIG. 5 is a diagram showing an enlarged view of a secondary battery sealing device 100 and a lead block according to an embodiment of the present invention, and FIG. 6 is a diagram showing a battery cell 101 to be sealed by the sealing device for a secondary battery according to an embodiment of the present invention shown in FIG. 5.

[0041] A secondary battery sealing device 100 according to an embodiment of the present invention can be used during a pouch packaging process performed between a plate stacking process and an electrolyte injection process in a process of manufacturing a pouch type secondary battery.

[0042] Specifically, the sealing device 100 of the secondary battery is used in a sealing process for joining a preset joining target area S between the pouch 104 and the lead 102 of the battery cell 101 through the lead film 103 of the battery cell 101.

[0043] FIG. 7 is a diagram for explaining the positions of the battery cell, a pair of sealing blocks, and a pair of lead blocks when the sealing process is performed by the secondary battery sealing device shown in FIG. 5. FIG. 8 is a diagram showing the leads of the battery cell, and FIG. 9 is a diagram showing the first lead block.

[0044] Referring to FIGS. 5 to 7, the secondary battery sealing device 100 according to an embodiment of the present invention may include a pair of sealing blocks 110 for pressing the battery cell 101, and a pair of lead blocks 120 provided on each of the pair of sealing blocks 110, on which the leads 102 of the battery cell 101 exposed outside the pouch are placed and which cover the placed leads 102.

[0045] The pair of sealing blocks 110 is a part for thermally pressing the battery cell 101, and functions to thermally press the joining target area S to seal the joining target area S.

[0046] Referring to FIGS. 6 and 7, the battery cell 101 may be a pouch-type secondary battery, and may include an electrode laminate 101a in which a plurality of electrodes and a separator are alternately laminated, and a pouch 104 surrounding the electrode laminate 101a. At this time, the electrode laminate 101a is accommodated inside the pouch 104, and a pair of leads 102 provided at both ends of the electrode laminate 101a are packaged by the pouch 104 so as to be respectively exposed outside the pouch 104.

[0047] The secondary battery sealing device 100 includes a pair of sealing blocks 110 on which the battery cell 101 is placed and which are arranged to pressurize the pouch 104 of the placed battery cell 101 and the bonding target area S of the lead film 103, and a pair of lead blocks 120 on which the leads 102 of the battery cell 101 exposed to the outside of the pouch 104 are placed and which are arranged to cover the placed leads 102.

[0048] At least one of the pair of lead blocks 120 is provided with a recess 121 for accommodating the lead 102 .

[0049] Here, a pair of sealing blocks 110 applies heat and pressure to a predetermined bonding target area S between the pouch 104 and the lead 102 via the lead film 103 .

[0050] The pair of sealing blocks 110 may include a first sealing block 112 and a second sealing block 114. The first sealing block 112 and the second sealing block 114 may be installed at a predetermined interval from each other in the vertical direction of the main body 100a of the secondary battery sealing device 100.

[0051] At least one of the first sealing block 112 and the second sealing block 114 may be connected to a driving unit 170 such as a cylinder and may be installed to be able to move up and down within the main body 100a. The driving unit 170 can adjust the gap between the first sealing block 112 and the second sealing block 114, and when pressure is applied to the bonding target area S, at least one of the first sealing block 112 and the second sealing block 114 moves in a direction approaching each other, thereby reducing the gap between the first sealing block 112 and the second sealing block 114.

[0052] The first sealing block 112 and the second sealing block 114 press a preset bonding target area S of the battery cell 101.

[0053] Specifically, the battery cell 101 is placed on the first sealing block 112. For example, the lower surface of the bonding target area S of the battery cell 101 is placed on the first sealing block 112.

[0054] The second sealing block 114 presses the upper surface of the battery cell 101 placed on the first sealing block 112. Specifically, the second sealing block 114 presses the upper surface of the bonding area S of the battery cell 101 placed on the first sealing block 112.

[0055] As an example, the second sealing block 114 can descend in a direction approaching the first sealing block 112 to press the battery cell 101 placed on the first sealing block 112.

[0056] Also, the second sealing block 114 and the first sealing block 112 can transfer heat to the bonding target area S of the battery cell 101 while pressing the bonding target area S.

[0057] Here, heating members 161, 162 such as heaters can be respectively connected to the first sealing block 112 and the second sealing block 114. Thereby, the first sealing block 112 and the second sealing block 114 receive heat from the connected heating members 161, 162 and thermally press the bonding target area S of the battery cell 101. The heating members 161, 162 can be arranged inside the respective sealing blocks 112, 114, or can also be attached to one surface of the sealing blocks 112, 114.

[0058] On the other hand, a pair of lead blocks 120 can be respectively provided on the first sealing block 112 and the second sealing block 114.

[0059] The pair of lead blocks 120 are parts for supporting the leads 102 of the battery cell 101 exposed to the outside of the pouch 104 when the joining target area S of the battery cell 101 is pressurized by the first sealing block 112 and the second sealing block 114.

[0060] The pair of lead blocks 120 can include a first lead block 122 and a second lead block 124.

[0061] The first lead block 122 can be provided on the first sealing block 112. As an example, the first lead block 122 can be integrally formed with the first sealing block 112, and the first lead block 122 can be connected to the first sealing block 112 with a predetermined interval.

[0062] Also, the leads 102 of the battery cell 101 placed on the first sealing block 112 are placed on the first lead block 122. Specifically, when the lower surface of the joining target area S of the battery cell 101 is placed on the first sealing block 112, the lower surface of the lead 102 can be placed on the first lead block 122.

[0063] A recess 121 for accommodating the lead 102 can be formed on the opposing surface 123 of the first lead block 122 facing the second lead block 124.

[0064] The opposing surface 123 of the first lead block 122 can be formed flat along the edge except for the area where the recess 121 is formed.

[0065] The second lead block 124 can be provided on the second sealing block 114 so as to face the first lead block 122. As an example, the second lead block 124 can be integrally formed with the second sealing block 114, and the second lead block 124 can be connected to the second sealing block 114 with a predetermined interval.

[0066] At this time, unlike the first lead block 122, the opposing surface 125 of the second lead block 124 can be formed flat over the entire area.

[0067] When the second sealing block 114 is lowered toward the first sealing block 112 to press the battery cell 101, the second lead block 124 covers the lead 102 placed on the first lead block 122. Specifically, when the second sealing block 114 presses the upper surface of the bonding target area S of the battery cell 101, the second lead block 124 comes to surround the upper surface of the lead 102.

[0068] At this time, the area of the opposing surface 123 of the first lead block 122 excluding the recessed portion 121 can be in surface contact with the opposing surface 125 of the second lead block 124 along the edge.

[0069] On the other hand, the recessed portion 121 of the first lead block 122 can be formed to be recessed inward with respect to the opposing surface 121 of the first lead block 122 so as to accommodate the lead 102 inside. Therefore, the opposing surface 123 of the first lead block 122 has a step between the edge regions of the recessed portion 121.

[0070] Also, the recessed portion 121 can be formed only in a partial area of the first lead block 122. Alternatively, although the recessed portion 121 can be formed in the entire area of the first lead block 122, in order to minimize the portion of the lead 102 covered by the first lead block 122 and the second lead block 124 that is exposed to the atmosphere, it is preferable to form the recessed portion 121 only in a partial area (for example, the central area) excluding the edge of the opposing surface 123.

[0071] Referring to FIGS. 8 and 9, the width L2 of the recessed portion 121 can be formed to be equal to or greater than the width L1 of the lead 102. Preferably, the width L2 of the recessed portion 121 can be formed to be larger than the width L1 of the lead 102 exposed to the outside of the pouch.

[0072] For example, the width L2 of the recessed portion 121 can be formed to be approximately 2 mm to 4 mm larger than the width L1 of the lead 102, but is not necessarily limited thereto.

[0073] Also, the depth D2 of the recessed portion 121 can be formed to be equal to or greater than the thickness D1 of the lead 102. Preferably, the depth D2 of the recessed portion 121 can be formed to be greater than the thickness D1 of the lead 102 exposed outside the pouch.

[0074] For example, the depth D2 of the recessed portion 121 can be formed to be approximately 0.5 mm to 1 mm larger than the thickness D1 of the lead 102, but is not necessarily limited thereto.

[0075] At this time, heating members 131 and 132 can be provided on the pair of lead blocks 120, respectively. Heating members 131 and 132 such as heaters can be connected to the first lead block 122 and the second lead block 124, respectively. In such a configuration, the first lead block 122 and the second lead block 124 receive heat from the connected heating members 131 and 132, and the lead 102 disposed between the first lead block 122 and the second lead block 124 and the lead film 103 connected to the lead 102 can be heated. The heating members 131 and 132 can be disposed inside the respective lead blocks 122 and 124, or can also be attached to one surface of the respective lead blocks 122 and 124.

[0076] When the lead 102 having a certain amount of heat is accommodated inside the recessed portion 121, the portions of the lead 102 exposed to the atmosphere by the first lead block 122 and the second lead block 124 are minimized. As a result, there is an effect that the heat loss of the lead 102 can be minimized.

[0077] On the other hand, only a partial area of the lead 102 of the battery cell 101 exposed to the outside of the pouch can be inserted into the recessed portion 121. The lead 102 and the lead film 103 not accommodated inside the recessed portion 121 are exposed to the outside of the first lead block 122 and the second lead block 124.

[0078] In other words, when the first lead block 122 and the second lead block 124 are in surface contact with each other, both side surfaces 102a and the terminal end portion 102b of the lead 102 are inserted into the recessed portion 121. At this time, the lead film 103 is provided, and the connecting portion 102c of the lead 102 adjacent to the electrode assembly is not located inside the recessed portion 121 and is exposed to the outside of the first lead block 122 and the second lead block 124.

[0079] The recessed portion 121 has a bottom surface 121b and a plurality (for example, three) of side surfaces 121a connected to the bottom surface 121b. At this time, when the lead 102 is placed on the bottom surface 121b, two of the plurality of side surfaces 121a face both side surfaces 102a of the lead 102, and one side surface 121a faces the terminal end portion 102b of the lead 102.

[0080] The joining target region S between the connecting portion 102c of the lead 102 and the lead film 103 exposed from the first lead block 122 and the second lead block 124 is heat-pressed and sealed by the first sealing block 112 and the second sealing block 114.

[0081] In this way, since both side surfaces 102a and the terminal end portion 102b of the lead 102 are accommodated inside the first lead block 122 and the second lead block 124 by the recessed portion 121, the remaining surfaces of the lead 102 excluding the connecting portion 102c provided with the lead film 103 are not exposed to the atmosphere, so that there is an effect that heat loss of the lead 102 can be minimized.

[0082] As described above, the embodiment in which the recessed portion 121 for accommodating the lead 102 is formed in the first lead block 122 has been described. However, the present invention is not limited to this, and the recessed portion may be provided in the first lead block and the second lead block, respectively.

[0083] At this time, the recessed portion formed in the first lead block (also referred to as the "first recessed portion") and the recessed portion formed in the second lead block (also referred to as the "second recessed portion") can also form a housing space for the lead 102 together.

[0084] At this time, the total depth of the recessed portions formed in the respective lead blocks 122 and 124 may be equal to or greater than the thickness of the lead. For example, the thickness of the first recessed portion may be equal to or greater than 1 / 2 of the thickness of the lead, and the thickness of the second recessed portion may be equal to or greater than 1 / 2 of the thickness of the lead.

[0085] The preferred embodiments of the present invention described above are disclosed for illustrative purposes. Those skilled in the art with ordinary knowledge of the present invention can make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be regarded as belonging to the following claims.

Industrial Applicability

[0086] According to the secondary battery sealing device according to an embodiment of the present invention, during the pouch sealing process of the secondary battery, the portion of the lead exposed to the atmosphere is minimized, so that the heat loss of the lead can be minimized.

Claims

1. A sealing device for joining a pouch of a battery cell and a lead film, comprising: a pair of sealing blocks provided to press a joining target area of the pouch and the lead film of the placed battery cell; a pair of lead blocks on which leads of the battery cell exposed outside the pouch are placed and which are provided to cover the placed leads. A secondary battery sealing device, wherein at least one of the pair of lead blocks is provided with a recess for accommodating the lead.

2. The secondary battery sealing device according to claim 1, wherein the pair of lead blocks are provided such that regions excluding the recess contact each other along the edge of the lead.

3. The secondary battery sealing device according to claim 1, wherein the width of the recess is equal to or greater than the width of the lead.

4. The secondary battery sealing device according to claim 1, wherein the depth of the recess is equal to or greater than the thickness of the lead.

5. The secondary battery sealing device according to claim 1, wherein the pair of lead blocks are provided to cover the placed lead when the pair of sealing blocks press the joining target area with the lead placed thereon.

6. The secondary battery sealing device according to claim 2, wherein when the lead is accommodated in the recess by the pair of lead blocks, the pair of lead blocks are provided to be in surface contact with each other at least in a partial region along the edge of the lead, excluding the region where the recess is formed.

7. The pair of sealing blocks include a first sealing block that supports the lower side of the battery cell so that the battery cell can be placed thereon, and a second sealing block that moves toward the first sealing block to press the battery cell placed on the first sealing block. The pair of lead blocks includes a first lead block coupled to the first sealing block such that the lead is placed thereon when the battery cell is placed on the first sealing block, and a second lead block coupled to the second sealing block and provided so as to cover the lead placed on the first lead block when the second sealing block moves toward the first sealing block. The secondary battery sealing device according to claim 1.

8. The recessed portion is provided in the first lead block. The secondary battery sealing device according to claim 7.

9. The width of the recessed portion is equal to or greater than the width of the lead. The secondary battery sealing device according to claim 7.

10. The depth of the recessed portion is equal to or greater than the thickness of the lead. The secondary battery sealing device according to claim 7.

11. When the lead is covered by the second lead block, the opposing surfaces of the first lead block and the second lead block are provided to be in surface contact with each other along the edge of the lead, excluding the region where the recessed portion is formed. The secondary battery sealing device according to claim 10.

12. The lead and the lead film exposed on the open side of the recessed portion are pressed by the first sealing block and the second sealing block. The secondary battery sealing device according to claim 11.

13. The recessed portion is provided in each of the first lead block and the second lead block. The total depth of the recessed portion formed in each lead block is equal to or greater than the thickness of the lead. The secondary battery sealing device according to claim 7.

14. Heating members are provided in each of the pair of lead blocks. The secondary battery sealing device according to any one of claims 1 to 13.

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