Pouch-shaped battery case sealing device and pouch-shaped secondary battery sealing method using the same

Abstract

The present invention relates to a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device. When manufacturing a pouch-shaped battery, in the process of applying heat and pressure to the outer periphery of a battery case made of a laminate sheet to seal the outer periphery of the battery case, the pouch-shaped battery case sealing device can adjust the direction in which an upper sealing block used to press the laminate sheet applies pressure to the laminate sheet.

Description

Technical Field

[0001] This application claims the benefit of priority to Korean Patent Application No. 2020-0184336, filed on December 28, 2020, and the disclosure of that Korean Patent Application is incorporated herein by reference in its entirety.

[0002] The present invention relates to a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device. More specifically, the present invention relates to a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device, which can adjust the direction in which an upper sealing block for pressing a laminate sheet applies pressure to the laminate sheet during the process of applying heat and pressure to the outer periphery of a battery case made of a laminate sheet to seal the outer periphery of the battery case when manufacturing a pouch-shaped battery. Background Art

[0003] The demand for secondary batteries as energy sources for mobile devices, electric vehicles, etc. has been drastically increasing. In particular, the demand for lithium secondary batteries having high energy density and high discharge voltage is high.

[0004] Based on the shape and material of the battery case, lithium secondary batteries can be classified into cylindrical secondary batteries made of metal materials, prismatic secondary batteries made of metal materials, or pouch-shaped batteries made of laminated sheets. Pouch-shaped batteries have the following advantages: pouch-shaped secondary batteries are stacked with high integrity to have high energy density per unit weight, low manufacturing cost, and can be easily deformed. Therefore, pouch-shaped batteries are used in a variety of devices.

[0005] Generally, a laminate sheet including an outer coating layer, a metal barrier layer and an inner adhesive layer is formed to serve as a battery case of a pouch-shaped battery. An electrode assembly is accommodated in an accommodation portion formed in the laminate sheet together with an electrolyte solution, and the accommodation portion is sealed, thereby manufacturing a pouch-shaped battery.

[0006] like Figure 1 As shown, the pouch-shaped battery 50 is configured such that the electrode assembly 20 is installed in the accommodating portion 13 of the battery case 10, and the battery case 10 is composed of the pouch-shaped lower portion 11 and the pouch-shaped upper portion 12. In the electrode assembly 20, the positive electrode tab 21 and the negative electrode tab 22 are exposed to the outside of the battery case 10 in a state of being welded to two electrode leads 31 and 32, respectively. In a state where a pair of insulating films 41 are respectively provided at the upper and lower portions of the electrode lead 31 and a pair of insulating films 42 are respectively provided at the upper and lower portions of the electrode lead 32, the outer periphery of the battery case 10 is sealed.

[0007] The outer periphery of the battery case 10 is sealed by heat-melting and pressing the inner adhesive layer of the laminated sheet using a sealing tool that is long in the longitudinal direction.

[0008] Figure 2 1 is an exploded perspective view of a pouch-shaped battery case sealing device 500 according to Patent Document 1. The outer periphery of the pouch-shaped battery is disposed between a holder 100 and a sealing block 200. The holder 100, which is movable up and down, is moved downward by a lifting device 110, and the outer periphery of the pouch-shaped battery is heated and melted, thereby sealing the outer periphery of the pouch-shaped battery. The holder 100 and the lifting device 110 are fixed or tiltable in only one direction.

[0009] Traditionally, the holder 100 and the lifting device 110 are fixed. In recent years, the demand for secondary batteries has increased rapidly, and therefore various attempts have been made to reduce the process time for each step. Traditionally, the holder 100 fixed to the lifting device 110 fully presses the outer periphery of the laminate to seal the outer periphery of the laminate. Attempts have been made to change the structure of the holder so that it can be tilted in the direction toward the sealing block 200 so as to quickly and evenly perform the pressing. However, due to the tilting in only one direction, the defect rate of the pouch-shaped secondary battery is not reduced, and the yield is also reduced.

[0010] Patent document 1 relates to a battery cell having a welding excess portion, the battery cell comprising an electrode assembly and a battery case, the electrode assembly comprising a positive electrode, a negative electrode and a separator inserted between the positive electrode and the negative electrode, the battery case comprising a sealing excess portion, wherein the outer periphery of the battery case is sealed at the sealing excess portion when the electrode assembly is accommodated in the battery case, wherein the battery case is made of a laminate sheet, the laminate sheet having a first resin layer, a metal layer and a second resin layer stacked in sequence from a side facing the electrode assembly, the sealing excess portion having a structure in which a first sheet portion and a second sheet portion of the laminate sheet facing each other are joined to each other, and at least a portion of the sealing excess portion comprises a resin layer melting portion formed by a first resin layer of the first sheet portion and a first resin layer of the second sheet portion and a metal layer welding portion formed by an end portion of the metal layer of the first sheet portion and an end portion of the metal layer of the second sheet portion.

[0011] Patent document 1 discloses that first and second sealing tools are provided above and below the sheet portion, and these sealing tools are rotated so as to be tilted at a predetermined angle; however, as mentioned above, these sealing tools are configured to be tilted in only one direction. In addition, Patent document 1 discloses a device configured to further press a part of the portion to be sealed rather than the entire portion to be sealed, and the device cannot uniformly seal the entire portion to be sealed, while the present invention achieves uniform sealing of the entire portion to be sealed.

[0012] Patent document 2 relates to a sealing device for sealing secondary battery packaging materials, the sealing device comprising: a first sealing tool; a second sealing tool configured to perform sealing while facing the first sealing tool; a first pulling unit attached to an end of the first sealing tool; and a second pulling unit attached to an end of the second sealing tool to correspond to the first pulling unit, wherein, during the sealing process, the first pulling unit pulls the end of the first sealing tool in a direction toward the second sealing tool, and the second pulling unit pulls the end of the second sealing tool in a direction toward the first sealing tool.

[0013] Patent document 3 relates to a device for bending a sealing excess portion in a direction toward an electrode assembly accommodating portion of a battery cell, the sealing excess portion being formed on the outer periphery of the electrode assembly accommodating portion, the device comprising: a battery cell fixing clamp, to which the battery cell is mounted in a state in which the outer end of the sealing excess portion protrudes outward from the outer side of the clamp; a guide member, configured to press downwardly an inner end of the sealing excess portion adjacent to the electrode assembly accommodating portion in a first direction perpendicular to the ground to form a bending point; and a bending member, configured to press upwardly an outer end of the sealing excess portion while moving in a second direction opposite to the first direction, so that the outer end of the sealing excess portion is bent in a second direction based on the bending point; wherein, in a state in which the outer end of the sealing excess portion is bent in the second direction, the guide member returns to its position before being pressed, and the bending member rotates in a third direction perpendicular to the first direction and the second direction to further bend the outer end of the sealing excess portion in the third direction.

[0014] Patent document 4 relates to an electric power storage device and its packaging structure, wherein an electric power storage device unit is accommodated in two frames coupled to each other, the electric power storage device unit is configured so that the bottom of the electrode terminal is fixed to an adapter, the adapter is pressed and held by the frame, and the electric power storage unit floats relative to the frame using the adapter as a support point, whereby the electric power storage device unit is positioned by the frame and the electric power storage device unit can be easily manipulated.

[0015] Patent Documents 2 to 4 do not disclose a structure for freely moving the sealing tool, and therefore do not recognize the problem to be solved by the present invention.

[0016] As described above, in the sealing of the pouch-shaped battery which is recognized as an important problem in the present invention, a technology capable of uniformly sealing the surface to be sealed in a short time, thereby improving the sealing efficiency, has not been proposed.

[0017] (Patent Document 1) Korean Patent Application Publication No. 2016-0073097 (June 24, 2016) (“Patent Document 1”)

[0018] (Patent Document 2) Korean Patent Publication No. 1816333 (January 2, 2018) (“Patent Document 2”)

[0019] (Patent Document 3) Korean Patent Publication No. 2088214 (2020.03.06) (“Patent Document 3”)

[0020] (Patent Document 4) Japanese Patent Application Publication No. 2006-278263 (October 12, 2006) ("Patent Document 4") Summary of the invention

[0021] Technical issues

[0022] The present invention is made in view of the above problems, and an object of the present invention is to provide a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device, wherein the pouch-shaped battery case sealing device can evenly seal the portion to be sealed on the outer periphery of the pouch-shaped secondary battery, thereby improving the sealing efficiency and reducing the sealing time.

[0023] Technical Solution

[0024] In order to achieve the above-mentioned purpose, the present invention provides a pouch-shaped battery case sealing device, which includes an upper sealing block and a lower sealing block, wherein the surface to be sealed of the pouch-shaped battery case is arranged in an XY plane, the upper sealing block and the lower sealing block are arranged parallel to the Y axis, the upper sealing block is fixed to a fixed shaft that moves up and down along the Z axis so as to move up and down along the Z axis, and the upper sealing block and the fixed shaft are coupled to each other via a hip-joint coupling unit.

[0025] The coupling unit may be disposed in the middle of the upper sealing block, and the upper sealing block may tilt relative to the XY plane around the Z axis. Meanwhile, a guide member for preventing the upper sealing block from rotating around the Z axis may be formed near the upper sealing block.

[0026] The coupling unit may include a first inserting portion extending from the fixing shaft and a first supporting portion fixed to the upper sealing block, a distal end of the first inserting portion being spherical, and the first inserting portion being inserted into and fixed to the first supporting portion.

[0027] The coupling unit may include a second inserting portion extending from the upper sealing block and a second supporting portion provided at a distal end of the fixing shaft, the distal end of the second inserting portion being spherical, and the second inserting portion being inserted into and fixed to the second supporting portion.

[0028] The fixed shaft can move in a precession manner around the coupling unit relative to the Z axis.

[0029] The hip-jointed coupling unit can be replaced by a coupling unit having two or more joints.

[0030] In another aspect, the present invention provides a method of sealing a pouch-shaped battery using a pouch-shaped battery case sealing apparatus.

[0031] In still another aspect, the present invention provides a pouch-shaped battery sealed using the pouch-shaped battery case sealing apparatus.

[0032] Furthermore, the present invention can provide all possible combinations of the above solutions.

[0033] Beneficial Effects

[0034] It is obvious from the above description that the present invention can provide a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device, wherein the pouch-shaped battery case sealing device can evenly seal the sealed portion of the outer periphery of the pouch-shaped secondary battery, thereby improving the sealing efficiency while reducing the sealing time.

[0035] The sealing device according to the present invention can ensure a uniformly sealed surface in a shorter time while reducing the sealing defect rate. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 is an exploded perspective view of a conventional pouch-shaped battery.

[0037] Figure 2 is an exploded perspective view of the pouch-shaped battery case sealing device according to Patent Document 1.

[0038] Figure 3 is a schematic diagram of a conventional pouch-shaped battery case sealing device configured for tilting movement about only one axis.

[0039] Figure 4 is a schematic diagram of a pouch-shaped battery case sealing apparatus according to a first embodiment of the present invention.

[0040] Figure 5 is a schematic diagram of a pouch-shaped battery case sealing apparatus according to a second embodiment of the present invention.

[0041] Figure 6 Another example of the coupling unit is shown. DETAILED DESCRIPTION

[0042] Now, the preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement the preferred embodiments of the present invention. However, when describing the operating principle of the preferred embodiments of the present invention in detail, when the detailed description of the known functions and structures incorporated herein may confuse the subject matter of the present invention, the detailed description will be omitted.

[0043] In addition, the same reference numerals will be used throughout the drawings to represent components that perform similar functions or operations. In the case where a component is referred to as being connected to another component throughout the specification, the component may not only be directly connected to the other component, but the component may also be indirectly connected to the other component via other components. In addition, including a certain element does not mean excluding other elements, but means that these elements may be further included unless otherwise specified.

[0044] In addition, unless particularly limited, the description embodying elements by limitation or addition can be applied to all the inventions and does not limit the specific invention.

[0045] Furthermore, in the description of the invention and the claims of the present application, the singular form is intended to include the plural form unless otherwise specified.

[0046] Moreover, in the description of the present invention and the claims of this application, "or" includes "and", unless otherwise specified. Therefore, "including A or B" means three cases, namely, the case including A, the case including B, and the case including A and B.

[0047] Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

[0048] Figure 3 is a schematic diagram of a conventional pouch-shaped battery case sealing apparatus 1000 configured to perform tilting motion only about one axis.

[0049] The pouch-shaped battery case sealing device 1000 includes an upper sealing block 1100 and a lower sealing block 1200. In the pouch-shaped battery case sealing device 2000 or 3000 according to the present invention and the conventional pouch-shaped battery case sealing device 1000, the outer periphery of the pouch-shaped battery case to be sealed is positioned between the upper sealing block 1100, 2100 or 3100 and the lower sealing block 1200, 2200 or 3200 in the same manner.

[0050] In addition, the surface to be sealed of the pouch-shaped battery case is set in the XY plane, the upper sealing block 1100, 2100 or 3100 and the lower sealing block 1200, 2200 or 3200 are set parallel to the Y axis, the upper sealing block 1100, 2100 or 3100 is fixed to a fixed shaft 1110, 2110 or 3110 that moves up and down along the Z axis direction so as to move up and down along the Z axis direction, and the upper sealing block 1100, 2100 or 3100 and the fixed shaft 1110, 2110 or 3110 are coupled to each other via a coupling unit 1120, 2120 or 3120.

[0051] In the conventional pouch-shaped battery case sealing device 1000, the coupling unit 1120 is configured to perform uniaxial coupling. Thus, the upper sealing block 1100 performs rotational motion only in a plane parallel to the YZ plane around the center of the coupling unit 1120. The rotational motion may also be referred to as a spin motion around the X-axis.

[0052] In contrast, in the pouch-shaped battery case sealing apparatus 2000 or 3000 according to the first embodiment or the second embodiment of the present invention, coupling is achieved by a hip-jointed coupling unit 2120 or 3120 .

[0053] The coupling unit 2120 or 3120 may be disposed in the middle of the upper sealing block 2100 or 3100, and the upper sealing block 2100 or 3100 may perform a tilting motion around the Z axis, specifically, around the coupling unit 2120 or 3120 relative to the XY plane. Rotational motion around the Z axis is undesirable when performing the tilting motion. Thus, a guide (not shown) may be formed near the upper sealing block 2100 or 3100 to prevent rotational motion of the upper sealing block around the Z axis.

[0054] The upper sealing block 2100 or 3100 may perform a spinning motion around the X axis and a spinning motion around the Y axis. Thus, the pouch-shaped battery case sealing apparatus according to the present invention can perform sealing more efficiently than the conventional apparatuses 500 and 1000, thereby reducing processing time.

[0055] The coupling unit 2120 may include a first inserting portion 2124 extending from the fixing shaft 2110 and a first supporting portion 2126 fixed to the upper sealing block 2100, the end of the first inserting portion 2124 being spherical, and the first inserting portion 2124 being inserted into and fixed to the first supporting portion 2126. Figure 4 , A is an enlarged view of the first insert portion 2124 and the first support portion 2126. The first insert portion 2124 and the first support portion 2126 may be coupled to each other by interference fit, and a separate lubricant may be added therebetween.

[0056] The coupling unit 3120 may include a second inserting portion 3124 extending from the upper sealing block 3100 and a second supporting portion 3126 provided at the end of the fixing shaft 3110, the end of the second inserting portion 3124 being spherical, and the second inserting portion 3124 being inserted and fixed to the second supporting portion 3126. Figure 5 , B is an enlarged view of the second insert portion 3124 and the second support portion 3126. The second insert portion 3124 and the second support portion 3126 may be coupled to each other by interference fit, and a separate lubricant may be added therebetween.

[0057] At the same time, the fixed shaft 2110 or 3110 can move in a precession manner around the coupling unit 2120 or 3120 relative to the Z axis. Through this movement, the upper sealing block 2100 or 3100 is further pressed in the direction inclined from the lower sealing block 2200 or 3200. Assuming that the fixed shaft 2110 or 3110 is inclined from the Z axis by an angle t to precess, the central axis of the fixed shaft becomes R, and R can precess along the circle above. The up and down movement, inclination, and precession related to the drive of the upper end of the fixed shaft 2110 or 3110 are not particularly limited and are not shown in the figure. Those skilled in the art can select this configuration as needed.

[0058] Moreover, in the present invention, the hip-jointed coupling unit 2120 or 3120 may be replaced by a coupling unit 4120 having two or more joints. A representative example of a coupling unit having two or more joints is shown in FIG. Figure 6 .exist Figure 6 , C and C' are portions coupled to the upper sealing block and the fixed shaft, respectively, or portions coupled to the fixed shaft and the upper sealing block, respectively.

[0059] In another aspect, the present invention provides a method of sealing a pouch-shaped battery using a pouch-shaped battery case sealing apparatus. In yet another aspect, the present invention provides a pouch-shaped battery sealed using a pouch-shaped battery case sealing apparatus.

[0060] Those skilled in the art to which the present invention pertains will appreciate that various applications and modifications are possible within the scope of the present invention based on the above description.

[0061] (Explanation of Reference Numerals)

[0062] 10: Battery housing

[0063] 11: Lower part

[0064] 12: Upper part

[0065] 13: Accommodation

[0066] 20: Electrode assembly

[0067] 21, 22: Electrode tabs

[0068] 31, 32: Electrode leads

[0069] 41, 42: Insulation film

[0070] 50: Pouch cell

[0071] 100: Holder

[0072] 110: Lifting device

[0073] 200: Sealing block

[0074] 300: Spacer

[0075] 500: Conventional pouch battery case sealing equipment

[0076] 1000: Conventional pouch cell housing sealing equipment

[0077] 2000: Pouch-shaped battery case sealing device according to the first embodiment of the present invention

[0078] 3000: Pouch-shaped battery case sealing device according to the second embodiment of the present invention

[0079] 1100, 2100, 3100: Upper sealing block

[0080] 1200, 2200, 3200: Lower sealing block

[0081] 1110, 2110, 3110: Fixed shaft

[0082] 1120, 2120, 3120, 4120: coupling unit

[0083] 2124, 3124: first insertion part, second insertion part

[0084] 2126, 3126: first support part, second support part

[0085] R: The center axis of the fixed axis when it is tilted from the Z axis by angle t to precess

[0086] A, B: Enlarged view of the coupling unit

[0087] Industrial Applicability

[0088] The present invention relates to a pouch-shaped battery case sealing device and a pouch-shaped secondary battery sealing method using the pouch-shaped battery case sealing device. When manufacturing a pouch-shaped battery, in the process of applying heat and pressure to the outer periphery of a battery case made of a laminate sheet to seal the outer periphery of the battery case, the pouch-shaped battery case sealing device can adjust the direction in which an upper sealing block used to press the laminate sheet applies pressure to the laminate sheet, so the present invention has industrial applicability.

Claims

1. A pouch-shaped battery housing sealing device, the pouch-shaped battery housing sealing device comprising an upper sealing block and a lower sealing block, wherein The surface to be sealed of the pouch-shaped battery housing is arranged in the XY plane, The upper sealing block and the lower sealing block are arranged parallel to the Y axis, The upper sealing block is fixed to a fixed shaft that moves up and down along the Z-axis direction so as to move up and down along the Z-axis direction, and The upper sealing block and the fixed shaft are coupled to each other via a hip-jointed coupling unit. 2 . The pouch-shaped battery case sealing apparatus according to claim 1 , wherein the coupling unit is disposed in the middle of the upper sealing block. 3 . The pouch-shaped battery case sealing apparatus according to claim 1 , wherein the upper sealing block is configured to perform a tilting motion around the Z axis relative to the XY plane. 4 . The pouch-shaped battery case sealing apparatus of claim 1 , wherein a guide for preventing rotational movement of the upper sealing block about the Z axis is formed near the upper sealing block.

5. The pouch-shaped battery case sealing device according to claim 1, wherein the coupling unit comprises: a first insertion portion extending from the fixed shaft, the first insertion portion having a spherical distal end; and A first supporting portion is fixed to the upper sealing block, and the first inserting portion is inserted into and fixed to the first supporting portion.

6. The pouch-shaped battery case sealing device according to claim 1, wherein the coupling unit comprises: a second insert portion extending from the upper sealing block, the distal end of the second insert portion being spherical; and A second supporting portion is provided at a distal end of the fixing shaft, and the second insertion portion is inserted into and fixed to the second supporting portion. 7 . The pouch-shaped battery case sealing apparatus of claim 1 , wherein the fixing shaft is configured to move in a precession manner around the coupling unit with respect to the Z axis. 8 . The pouch-shaped battery case sealing apparatus according to claim 1 , wherein the hip-jointed coupling unit is replaced by a coupling unit having two or more engaging portions. 9 . A method of sealing a pouch-shaped battery using the pouch-shaped battery case sealing apparatus according to any one of claims 1 to 8 . 10 . A pouch-shaped battery sealed using the pouch-shaped battery case sealing apparatus according to any one of claims 1 to 8 .

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