Secondary battery sealing device

Abstract

The present invention relates to a sealing device for a secondary battery that manufactures a secondary battery by sealing the outer peripheral surface of a pouch case having an electrode assembly built in, the sealing device for a secondary battery including: a sealing tool that seals the outer peripheral surface of the pouch case and has a heat-insulating coating layer on its sides; a pair of sealing blocks that heat the sealing tool or support the pouch case; and a heating member that is located inside the sealing block and heats the sealing block.

Description

[Technical Field]

[0001] This application claims the benefit of the filing date of Korean Patent Application No. 10-2022-0147040, filed with the Korean Intellectual Property Office on November 7, 2022, the entire contents of which are incorporated herein by reference.

[0002] The present invention relates to a sealing device for a secondary battery. [Background technology]

[0003] In general, a secondary battery refers to a battery that can be charged and discharged, unlike a primary battery that cannot be charged. Such secondary batteries are widely used in the field of cutting-edge electronic devices such as mobile phones, laptops, and video cameras.

[0004] The secondary battery is crimped on one side with a crimping machine and undergoes a stability test to measure internal short circuits to ensure stability.

[0005] Depending on the shape of the battery case, secondary batteries are classified into cylindrical batteries and prismatic batteries, in which the electrode assembly is housed in a cylindrical or prismatic metal can, and pouch case batteries, in which the electrode assembly is housed in a pouch case made of an aluminum laminate sheet.

[0006] In manufacturing the pouch case type battery, the electrode assembly is housed inside the pouch case, and then the outer periphery of the pouch case is sealed by applying pressure and heat from above and below using a sealing tool.

[0007] In this case, the area of ​​the sealing tool where the electrode lead is located is located inside the sealing tool and is heated to a relatively higher temperature than the outside of the sealing tool, so the sealing part is not sealed at a uniform temperature, which causes a problem of not being able to ensure uniform sealing quality.

[0008] In addition, since the heat inside the sealing tool is released to the outside through the surface, it takes a long time to heat up after sealing one pouch case before sealing the next pouch case, which limits the reduction of the secondary battery processing time. Summary of the Invention [Problem to be solved by the invention]

[0009] In view of the above-mentioned problems of the prior art, the present invention aims to provide a sealing device for a secondary battery that prevents the temperature of the sealing tool from diffusing to the outside. [Means for solving the problem]

[0010] One embodiment of the present invention provides a sealing device for a secondary battery that seals the outer periphery of a pouch case containing an electrode assembly to manufacture a secondary battery, the sealing device including: a sealing tool that seals the outer periphery of the pouch case and has a heat-insulating coating layer on its side; a pair of sealing blocks that heat the sealing tool or support the pouch case; and a heating member that is located inside the sealing block and heats the sealing block.

[0011] In one embodiment of the present invention, a sealing device for a secondary battery is provided, wherein the secondary battery includes an electrode lead extending outside the pouch case, and the sealing tool includes a pouch case sealing portion that applies pressure and heat to an area of ​​the pouch case where the electrode lead is not located, and a lead sealing portion that applies pressure and heat to an area where the electrode lead is located.

[0012] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the lead seal portion is lower in height than the pouch case seal portion.

[0013] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the heat insulating coating layer located at the lead seal portion is thinner than the heat insulating coating layer located at the pouch case seal portion.

[0014] In one embodiment of the present invention, a sealing device for a secondary battery is provided, in which the pair of seal blocks have the heat insulating coating layer located on the outer surfaces other than the area where the seal tool is located.

[0015] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the thermal insulating coating layer includes an adhesive layer on one surface thereof that adheres to the sealing tool.

[0016] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the pair of seal blocks includes a space into which the heating member is drawn.

[0017] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the heating member is configured in a rod shape or a coil shape.

[0018] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein the sealing tool is located on one surface of at least one of a pair of the sealing blocks.

[0019] In one embodiment of the present invention, there is provided a sealing device for a secondary battery, wherein at least one of the pair of seal blocks further includes a moving member that moves the pair of seal blocks up and down. [Effects of the Invention]

[0020] A sealing device for a secondary battery according to an embodiment of the present invention may have a heat insulating coating layer positioned on the outer surface of the sealing tool that does not contact the pouch case, thereby minimizing the diffusion of heat from inside the sealing tool to the outside.

[0021] Furthermore, the sealing device for secondary batteries can make the temperature of the sealing tools uniform and make it easier to ensure uniform sealing quality by providing different thicknesses of the insulating coating layer on the sealing tool that seals the area where the pouch case and leads are stacked and the sealing tool that seals the area where only the pouch case is stacked. [Brief explanation of the drawings]

[0022] [Figure 1] 1 is a perspective view of a sealing device for a secondary battery according to an embodiment of the present invention. [Figure 2] 1 is an exploded perspective view of a sealing device for a secondary battery according to an embodiment of the present invention. [Figure 3] 1 is a plan view of a sealing device for a secondary battery according to an embodiment of the present invention. [Figure 4] 1(a) is a front view of a sealing device for a secondary battery according to one embodiment of the present invention, and FIG. 1(b) is a front view showing the state in which the sealing device for a secondary battery according to one embodiment of the present invention pressurizes the secondary battery. [Figure 5] FIG. 10 is a perspective view of a sealing device for a secondary battery according to another embodiment of the present invention. [Figure 6] 1 is a cross-sectional view illustrating heat generated by a heating element being transferred to a seal block and a seal tool according to one embodiment of the present invention. [Figure 7] 1 is a schematic diagram illustrating the structure of a thermal barrier coating layer according to one embodiment of the present invention. [Explanation of symbols]

[0023] 100 Sealing device for secondary battery 1 Pouch Case 2. Electrode lead 10. Sealing tool 11 Pouch case seal part 12 Lead seal part 20 Seal Block 30 Heating element 40 Thermal barrier coating layer 41...Adhesive layer 42 Insulation layer 50 Moving member DETAILED DESCRIPTION OF THE INVENTION

[0024] The detailed description of the present invention is intended to fully explain the present invention to those skilled in the art. Throughout the specification, when a part is described as "comprising" a certain element or "featuring" a certain structure and shape, this does not mean that other elements are excluded or that other structures and shapes are not present, and other elements, structures, and shapes may be included, unless otherwise specified.

[0025] The present invention may be modified in various ways and may have various embodiments, and specific embodiments will be presented and described in detail in the detailed description, but it should be understood that this is not intended to limit the content of the invention to the embodiments, and that all modifications, equivalents, or alternatives within the spirit and technical scope of the present invention are included.

[0026] The present invention will be described in detail below with reference to the drawings. However, the drawings are for illustrative purposes only and the scope of the present invention is not limited by the drawings.

[0027] FIG. 1 is a perspective view of a sealing device 100 for a secondary battery according to one embodiment of the present invention, FIG. 2 is an exploded perspective view of a sealing device 100 for a secondary battery according to one embodiment of the present invention, and FIG. 3 is a plan view of a sealing device for a secondary battery according to one embodiment of the present invention.

[0028] The sealing device 100 for a secondary battery according to the present invention includes a sealing tool 10 , a sealing block 20 , and a heating member 30 .

[0029] The sealing device 100 for a secondary battery seals the outer peripheral surface of a pouch case 1 that has an electrode assembly (not shown) built in. Here, the secondary battery is a pouch case type that can include the electrode assembly and the pouch case 1.

[0030] The electrode assembly may include a positive electrode, a negative electrode, and a separator. The electrode assembly may be accommodated in a pouch case to maximize its volume, thereby increasing energy density. This allows the secondary battery to have a large capacity and high output compared to a battery of the same size.

[0031] The pouch case 1 includes a storage space capable of accommodating the electrode assembly, and a sealed space located on the periphery of the storage space, in which either the pouch case 1 alone is stacked or the pouch case 1 and an electrode lead 2 (described later) are stacked and sealed. The storage space may be provided so that the electrode assembly occupies a maximum volume. The storage space may have the same volume or area as the electrode assembly.

[0032] The secondary battery may include an electrode lead 2 extending to the outside of the pouch case 1. The electrode lead 2 may protrude to the outside through the periphery of the pouch case 1.

[0033] More specifically, the electrode assembly may include a negative electrode tab and a positive electrode tab, on which the negative and positive electrode current collector plates are extended. The electrode lead 2 may extend from the negative electrode tab and the positive electrode tab and protrude to the outside through the sealed space of the pouch case 1. Therefore, the electrode lead 2 may be positioned between the pouch case 1 in the sealed space of the pouch case 1.

[0034] The sealing device 100 for a secondary battery according to the present invention can heat and pressurize the sealing space of the pouch case 1, thereby sealing the sealing space of the pouch case 1.

[0035] The sealing tool 10 seals the periphery of the pouch case 1. The contact surface of the sealed space of the pouch case 1 is coated with a sealant. The sealing tool 10 applies pressure and heat to the sealed space of the pouch case 1, thereby sealing the pouch case 1 in the sealed space.

[0036] The sealing tool 10 can include a pouch case sealing section 11 that applies pressure and heat to the area where only the pouch cases 1 are stacked and where the electrode leads 2 are not located, and a lead sealing section 12 that applies pressure and heat to the area where the electrode leads 2 are located between the pouch cases 1.

[0037] The electrode lead 2 can be located on one of the four sides of the electrode assembly or on two opposing sides thereof. Therefore, the sealing area of ​​the pouch case 1 can include a first sealing area including the electrode lead 2 and a second sealing area not including the electrode lead 2.

[0038] The sealing tool 10 may have different structures for sealing the first sealing area and the second sealing area. The sealing tool 10 for sealing the first sealing area may include both the pouch case sealing portion 11 and the lead sealing portion 12. The sealing tool 10 for sealing the second sealing area may include only the pouch case sealing portion 11.

[0039] Figure 4(a) is a front view of a sealing device 100 for a secondary battery according to one embodiment of the present invention, and Figure 4(b) is a front view showing the state in which the sealing device 100 for a secondary battery according to one embodiment of the present invention is pressurizing the secondary battery.

[0040] The lead seal portion 12 may be shorter in height than the pouch case seal portion 11. Here, the height refers to the distance between one surface of the sealing tool 10 that contacts the seal block 20 and the opposite surface.

[0041] The electrode lead 2 has a constant thickness, and the portion of the seal area where the electrode lead 2 is located is thicker than the portion where the electrode lead 2 is not located. Therefore, the lead seal part 12 is provided lower in height than the pouch case seal part 11, and can come into contact with the seal area that has become thicker due to the electrode lead 2. In other words, the lead seal part 12 can be provided lower in height than the pouch case seal part 11 by the thickness of the electrode lead 2.

[0042] When the secondary battery sealing device 100 pressurizes the pouch case 1 at the same pressure, the pouch case seal portion 11 and the lead seal portion 12 are pressurized at the same pressure by the electrode lead 2, regardless of the difference in thickness of the sealing area, and the same sealing quality can be ensured for both the first sealing area and the second sealing area.

[0043] The sealing tool 10 may have a heat insulating coating layer 40 on its side. Here, the side of the sealing tool 10 refers to a surface perpendicular to the surface that contacts the pouch case 1. In other words, the heat insulating coating layer 40 may be located on the outer surface excluding the surface opposite to the surface that contacts the sealing block 20.

[0044] The sealing tool 10 loses heat to the outside before, during, and after sealing the pouch case 1, but the heat insulating coating layer 40 can prevent the sealing tool 10 from losing heat to the outside, thereby achieving the economic effect of reducing the amount of heat source supplied when sealing the secondary battery.

[0045] The sealing tool 10 may have different thicknesses of the heat insulating coating layer 40 located on the side of the pouch case seal portion 11 and the lead seal portion 12.

[0046] In one embodiment, the sealing tool 10 may be provided with a pouch case seal portion 11, a lead seal portion 12, and a pouch case seal portion 11 in this order along the length of the seal block 20. In this case, the lead seal portion 12 located between the pouch case seal portions 11 has a higher temperature than the pouch case seal portion 11, and receives less convection heat (heat escaping from the sealing tool 10 to the outside). Therefore, the sealing tool 10 may be provided with a thermal insulating coating layer 40 located on the lead seal portion 12 that is thinner than the thermal insulating coating layer 40 located on the pouch case seal portion 11.

[0047] Because the heat insulating coating layer 40 located on the pouch case seal portion 11 is thicker than the heat insulating coating layer 40 located on the lead seal portion 12, the convection heat of the pouch case seal portion 11 is smaller than the convection heat of the lead seal portion 12, and the temperature of the sealing tool 10 can be maintained uniformly. And, because the temperature of the sealing tool 10 is maintained uniformly, the sealing quality of the pouch case 1 can be maintained uniformly.

[0048] FIG. 7 is a schematic diagram illustrating the structure of a thermal barrier coating layer 40 according to one embodiment of the present invention.

[0049] The thermal barrier coating layer 40 may include an adhesive layer 41 that is bonded to a base material such as the seal tool 10 or the seal block 20, and a thermal barrier layer 42 that is provided on one side of the adhesive layer 41 and prevents heat from the base material from radiating to the outside. The adhesive layer 41 must change phase depending on the temperature of the base material, and may include, for example, one or more of NiCoCrAlY, NiCrAlY, and CoCrAlY. The thermal barrier layer 42 may include, for example, one or more of stabilized zirconia, yttria, and aluminum oxide.

[0050] The sealing block 20 heats the sealing tool 10 or supports the pouch case 1. The sealing block 20 can be configured in pairs.

[0051] In one embodiment, the sealing block 20 may have the sealing tool 10 positioned on one side thereof. In this case, the sealing block 20 heats the sealing tool 10 and does not come into contact with the pouch case 1.

[0052] In another embodiment, the sealing block 20 may not have the sealing tool 10 positioned on one side thereof. In this case, the sealing block 20 may support the pouch case 1 in which the electrode assembly is housed, more specifically, the sealing area of ​​the pouch case 1.

[0053] FIG. 5 is a perspective view showing a sealing device 100 for a secondary battery according to another embodiment of the present invention.

[0054] Referring to FIG. 1, both of the pair of seal blocks 20 may be constructed of seal blocks 20 according to one embodiment.

[0055] 5, one may be configured with a sealing block 20 according to one embodiment and the other with a sealing block 20 according to another embodiment. In this case, the sealing block 20 according to another embodiment does not have a heat insulating coating layer 40 positioned in an area corresponding to the sealing tool 10 of the sealing block 20 according to the one embodiment. Therefore, the sealing block 20 according to another embodiment can support and heat the pouch case 1 at the area corresponding to the sealing tool 10.

[0056] The sealing device 100 for a secondary battery may further include a moving member 50 that moves the sealing block 20 up and down. The moving member 50 moves the sealing block 20 to apply pressure to the pouch case 1, and may be provided on the other side of the sealing block 20, i.e., the side opposite to the side on which the sealing tool 10 is located.

[0057] For example, when a pair of seal blocks 20 both include the seal block 20 according to one embodiment, the moving member 50 can be provided on both of the pair of seal blocks 20 .

[0058] Alternatively, when a pair of seal blocks 20 includes seal blocks 20 according to one embodiment and another embodiment, the moving member 50 may be provided on only one of the pair of seal blocks 20. In this case, the seal block 20 according to the one embodiment may be located on top of the pouch case 1, and the pouch case 1 may be mounted on one surface of the seal block 20 according to another embodiment.

[0059] Alternatively, when a pair of seal blocks 20 includes seal blocks 20 according to one embodiment and another embodiment, respectively, the moving member 50 can be provided on both of the pair of seal blocks 20 .

[0060] The seal block 20 may have a thermal barrier coating layer 40 on the surface where the sealing tool 10 is not located to prevent convection heat from occurring through the surface where the sealing tool 10 is not located. The thermal barrier coating layer 40 may be located on the portion of the surface where the sealing tool 10 is located where the sealing tool 10 is not located, as well as on the side and bottom surface of the seal block 20. The side surface of the seal block 20 refers to the surface perpendicular to the surface where the sealing tool 10 is located, and the bottom surface refers to the surface opposite to the surface where the sealing tool 10 is located.

[0061] The heat insulating coating layer 40 located on the side and bottom surfaces of the seal block 20 is either adhered to the side surfaces of the seal block 20 or configured as a case having a shape corresponding to the side surfaces and bottom surfaces of the seal block 20, and is detachable.

[0062] The sealing device 100 for a secondary battery according to the present invention includes a heating member 30 that heats the seal block 20. The heating member 30 may be located inside the seal block 20. Therefore, the seal block 20 may include a space into which the heating member 30 is drawn.

[0063] For example, the seal block 20 may include a cylindrical hollow space along its length, and the heating element 30 may be recessed into the cylindrical or coiled hollow space of the seal block 20.

[0064] FIG. 6 is a cross-sectional view illustrating the transfer of heat generated by heating element 30 to seal block 20 and seal tool 10 according to one embodiment of the present invention.

[0065] The heating element 30 heats the seal block 20, and the heated seal block 20 heats the seal tool 10 that is in direct contact with one surface of the seal block 20. The heat insulating coating layer 40 located on the surfaces of the seal block 20 and the seal tool 10 prevents the heat of the seal block 20 and the seal tool 10 from radiating to the outside.

[0066] Although the present invention has been described above with reference to preferred embodiments, those skilled in the art will understand that the present invention can be modified and changed in various ways without departing from the spirit and scope of the present invention as set forth in the claims below.

Claims

1. A sealing device for a secondary battery that manufactures a secondary battery by sealing the outer periphery of a pouch case containing an electrode assembly, comprising: a sealing tool for sealing the outer periphery of the pouch case, the sealing tool having a heat insulating coating layer on its side; a pair of sealing blocks for heating the sealing tool or supporting the pouch case; and a heating element positioned inside the seal block and configured to heat the seal block; Including, the secondary battery includes electrode leads extending to the outside of the pouch case; the sealing tool includes a pouch case sealing portion that applies pressure and heat to an area of ​​the pouch case where the electrode lead is not located, and a lead sealing portion that applies pressure and heat to an area where the electrode lead is located, The sealing device for a secondary battery, wherein the heat insulating coating layer located at the lead seal portion is thinner than the heat insulating coating layer located at the pouch case seal portion.

2. A sealing device for a secondary battery that manufactures a secondary battery by sealing the outer periphery of a pouch case containing an electrode assembly, comprising: a sealing tool for sealing the outer periphery of the pouch case, the sealing tool having a heat insulating coating layer on its side; a pair of sealing blocks for heating the sealing tool or supporting the pouch case; and a heating element positioned inside the seal block and configured to heat the seal block; Including, The heat insulating coating layer includes an adhesive layer on one surface thereof that adheres to the sealing tool.

3. the secondary battery includes electrode leads extending to the outside of the pouch case; 3. The sealing device for a secondary battery according to claim 2, wherein the sealing tool includes a pouch case sealing portion that applies pressure and heat to an area of ​​the pouch case where the electrode lead is not located, and a lead sealing portion that applies pressure and heat to an area where the electrode lead is located.

4. The sealing device for a secondary battery according to claim 1 or 3, wherein the lead seal portion is lower in height than the pouch case seal portion.

5. 4. The sealing device for a secondary battery according to claim 3, wherein the heat insulating coating layer located at the lead seal portion is thinner than the heat insulating coating layer located at the pouch case seal portion.

6. The sealing device for a secondary battery according to claim 1 or 2, wherein the heat insulating coating layer is located on the outer surfaces of the pair of seal blocks other than the area where the seal tool is located.

7. The sealing device for a secondary battery according to claim 1 , wherein the heat insulating coating layer includes an adhesive layer on one surface thereof that adheres to the sealing tool.

8. The sealing device for a secondary battery according to claim 1 or 2, wherein the pair of seal blocks includes a space into which the heating member is drawn.

9. The sealing device for a secondary battery according to claim 1 or 2, wherein the heating member is configured in a rod shape or a coil shape.

10. The sealing device for a secondary battery according to claim 1 or 2, wherein the sealing tool is located on one surface of at least one of the pair of seal blocks.

11. 3 . The sealing device for a secondary battery according to claim 1 , wherein at least one of the pair of seal blocks further includes a moving member that moves the pair of seal blocks up and down.

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