Method for Sealing an Electrode Assembly and Sealing Apparatus Therefor

Abstract

According to an embodiment of the present invention, there is provided a method for sealing an electrode assembly including a plurality of electrodes stacked alternately with a separator interposed therebetween, the method may include seating the electrode assembly in a nest, and spraying hot air toward corners of the electrode assembly to seal them. According to another embodiment of the present invention, a sealing device for an electrode assembly including a plurality of electrodes stacked alternately with a separator sandwiched therebetween may include a nest supporting the electrode assembly, and a hot air device for spraying hot air to corners of the electrode assembly to contactlessly seal the corners. According to an embodiment of the present invention, since sealing is performed in a contactless manner, it is possible to minimize impact and damage to the sealing target or parts other than the sealing area that may occur due to physical contact during sealing. Also, it is possible to adaptively ensure uniform and stable sealing quality by controlling the sealing conditions according to the situation.

Description

Technical Field

[0001] [Cross - Reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2021 - 0182155, filed on December 17, 2021, and all the contents disclosed in the literature of the Korean patent application are included as part of this specification.

[0002] The present invention relates to a method for sealing an electrode assembly and a sealing device for sealing an electrode assembly.

Background Art

[0003] In response to the need for an energy source that can replace petroleum energy which induces environmental pollution, research and development related to power generation based on energy sources with less impact on environmental pollution, such as solar heat, hydropower, wind power, ocean energy, biomass energy, etc., are underway. In particular, research on rechargeable secondary batteries is actively underway, and development is being carried out on aspects such as materials, efficiency, structure, and stability of secondary batteries.

[0004] Various processes are involved in producing secondary batteries, and processes corresponding to various forms of secondary batteries, such as pouch type, rectangular type, cylindrical type, etc., are applied. Usually, secondary batteries are produced through processes such as an electrode process, an assembly process, a formation process, etc., and there are differences in the processes depending on the form of the secondary battery. In particular, regarding the assembly process, a winding process, a stacking process, a folding process, etc. are carried out depending on the form of the secondary battery.

[0005] In the assembly process of secondary batteries, sealing for assembling and sealing secondary batteries is performed. Generally, sealing is performed by bringing a sealing block at a set temperature into contact with the sealing area and heat - welding it at a set pressure.

[0006] However, according to the conventional technology, since the sealing block physically contacts the sealing area for sealing, there is a possibility that heat is applied to an unintended area or an impact is applied to an object that is not the sealing target.

Summary of the Invention

Problems to be Solved by the Invention

[0007] The problem to be solved by the present invention is to provide a sealing method and a sealing device that can perform sealing on a sealing target or a sealing area without physical contact, and can control the conditions related to sealing to ensure the quality of sealing.

Means for Solving the Problems

[0008] A sealing method for an electrode assembly including a plurality of electrodes alternately laminated with a separation membrane according to an embodiment of the present invention may include a step of fixing the electrode assembly in a nest, and a step of sealing by injecting hot air toward a corner portion of the electrode assembly.

[0009] In the step of sealing, the hot air can be injected toward the corner portion using a hot air device including a nozzle.

[0010] In the sealing method, the hot air device can adjust at least one of the temperature, pressure, injection time, and injection angle of the hot air.

[0011] The sealing method may further include a step of moving the hot air device toward the corner portion of the electrode assembly using a driving device before the step of sealing.

[0012] In the sealing method, the driving device can adjust the distance between the hot air device and the corner portion.

[0013] In the sealing method, the electrode assembly may include a long side formed parallel to a first direction and a short side formed in a second direction perpendicular to the first direction, and may include a step of adjusting an injection angle of the hot air with respect to the first direction and the second direction.

[0014] In the sealing method, a plurality of corner portions are provided, and the hot air can be blown using the same number of hot air devices corresponding to the plurality of corner portions.

[0015] A sealing device for an electrode assembly including a plurality of electrodes laminated alternately with a separation membrane according to another embodiment of the present invention may include a nest that supports the electrode assembly and a hot air device that injects hot air into a corner portion of the electrode assembly to perform non-contact sealing of the corner portion.

[0016] The hot air device may include a main body and a nozzle whose angle with respect to the main body is variable.

[0017] The sealing device may include a driving device that moves the hot air device with respect to the corner portion.

[0018] The hot air device can adjust at least one of a temperature, a pressure, an injection time, and an injection angle of the hot air.

[0019] The electrode assembly includes a long side formed parallel to a first direction and a short side formed in a second direction perpendicular to the first direction, and the hot air device can control the nozzle to adjust an injection angle of the hot air with respect to the first direction and the second direction.

Advantages of the Invention

[0020] According to an embodiment of the present invention, since sealing is performed in a non-contact manner, it is possible to minimize impacts and damages to portions that are not a sealing target or a sealing region that may be caused by physical contact during sealing.

[0021] According to an embodiment of the present invention, by controlling the conditions for sealing according to the situation, it is possible to adaptively ensure uniform and stable sealing quality.

Brief Description of the Drawings

[0022]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Modes for Carrying Out the Invention

[0023] Hereinafter, with reference to the accompanying drawings, preferred embodiments of the present invention will be described in detail so that those having ordinary knowledge in the technical field to which the present invention pertains can easily implement it. However, the present invention may be embodied in various different forms and is not limited or restricted by the following embodiments.

[0024] In order to clearly explain the present invention, detailed descriptions of parts not related to the description or known technologies that may obscure the gist of the present invention are omitted. In this specification, when adding reference numerals to the components of each drawing, the same or similar reference signs are given to the same or similar components throughout the specification.

[0025] In addition, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary and dictionary meanings. In accordance with the principle that the inventor himself / herself can appropriately define the concept of the terms in order to explain the invention in the best way, they must be construed in a meaning and concept that conforms to the technical idea of the present invention.

[0026] FIG. 1 shows an electrode assembly 100 and the arrangement of the electrode assembly 100 according to an embodiment of the present invention.

[0027] The electrode assembly 100 may include a negative electrode 110, a separator 120, and a positive electrode 130. For example, the electrode assembly 100 may include electrodes alternately laminated with the separator 120 interposed therebetween. The electrodes may include a plurality of negative electrodes 110 and a plurality of positive electrodes 130.

[0028] The electrode assembly 100 may include a negative electrode tab 140 and a negative electrode lead 141. For example, the plurality of negative electrodes 110 of the electrode assembly 100 may be electrically connected to the negative electrode tab 140. The negative electrode tab 140 may be electrically connected to the negative electrode lead 141, and the negative electrode lead 141 may be electrically connected to the outside of the electrode assembly 100. The plurality of negative electrodes 110 of the electrode assembly 100 may be electrically connected to the outside of the electrode assembly 100 by being electrically connected to the negative electrode tab 140 and the negative electrode lead 141.

[0029] The electrode assembly 100 may include a positive electrode tab 150 and a positive electrode lead 151. For example, the plurality of positive electrodes 130 of the electrode assembly 100 may be electrically connected to the positive electrode tab 150. The positive electrode tab 150 may be electrically connected to the positive electrode lead 151, and the positive electrode lead 151 may be electrically connected to the outside of the electrode assembly 100. The plurality of positive electrodes 130 of the electrode assembly 100 may be electrically connected to the outside of the electrode assembly 100 by being electrically connected to the positive electrode tab 150 and the positive electrode lead 151.

[0030] The electrode assembly 100 may include corner portions 301, 302, 303, and 304. For example, the electrode assembly 100 may include a long side formed parallel to the first direction and a short side formed in a second direction perpendicular to the first direction. The corner portions 301, 302, 303, and 304 may mean the portions where the aforementioned long side and short side meet. As another example, when the electrode assembly 100 has a shape corresponding to a quadrilateral having four sides (or edges) when viewed from above, four corner portions may be formed. As yet another example, when the electrode assembly 100 has a shape corresponding to a hexahedron, four sides (or edges) connecting two opposite faces may become the corner portions.

[0031] Sealing for the electrode assembly 100 may be performed based on a sealing device.

[0032] The sealing device may include a nest 10. For example, the electrode assembly 100 may be disposed on the nest 10. When the sealing device performs sealing, sealing for the electrode assembly 100 may be performed with the electrode assembly 100 disposed on the nest 10.

[0033] The sealing device may include hot air devices 310, 320, 330, and 340, and the sealing device can control the hot air devices 310, 320, 330, and 340. The hot air devices will be described later with reference to FIGS. 2 to 5.

[0034] FIG. 2 shows the flow of a method for sealing the electrode assembly 100 according to another embodiment of the present invention.

[0035] According to step 210, the electrode assembly 100 may be seated on the nest 10.

[0036] Sealing may be performed with the electrode assembly 100 seated on the nest 10 of the sealing device. However, it is not limited thereto.

[0037] According to step 220, the hot air devices 310, 320, 330, and 340 may be moved toward the corner portions 301, 302, 303, and 304 of the electrode assembly 100.

[0038] The sealing device may include the hot air devices 310, 320, 330, and 340.

[0039] The sealing device can be controlled to move the hot air devices 310, 320, 330, and 340 so as to be close to the corner portions 301, 302, 303, and 304 of the electrode assembly 100. The sealing device can also be controlled to move the hot air devices 310, 320, 330, and 340 away from the corner portions 301, 302, 303, and 304 of the electrode assembly 100.

[0040] The sealing device may be provided with a plurality of hot air devices 310, 320, 330, and 340. For example, the same number of hot air devices 310, 320, 330, and 340 corresponding to the number of the corner portions 301, 302, 303, and 304 of the electrode assembly 100 may be provided.

[0041] The sealing device may include a driving device.

[0042] The sealing device can control the movement of the hot air devices 310, 320, 330, and 340 by using (or controlling) the driving device. For example, the sealing device can use the driving device to move the hot air devices 310, 320, 330, and 340 toward the corner portions 301, 302, 303, and 304 of the electrode assembly 100. As another example, the sealing device can use the driving device to move the hot air devices 310, 320, 330, and 340 away from the corner portions 301, 302, 303, and 304 of the electrode assembly 100. As still another example, the sealing device can use the driving device to adjust the distance between the hot air devices 310, 320, 330, and 340 and the corner portions 301, 302, 303, and 304.

[0043] The sealing device may be provided with a plurality of driving devices. For example, the sealing device may include a number of driving devices corresponding to the number of corner portions 301, 302, 303, and 304 of the electrode assembly 100.

[0044] The sealing device can control a plurality of driving devices simultaneously, or can control them separately. For example, the sealing device can control a plurality of driving devices simultaneously to control the movements of the hot air devices 310, 320, 330, and 340 simultaneously. Another example is that the sealing device can separately control the movements of the hot air devices 310, 320, 330, and 340 by using a plurality of driving devices corresponding to the hot air devices 310, 320, 330, and 340 respectively.

[0045] According to step 230, the separation films at the corner portions 301, 302, 303, and 304 can be sealed by injecting hot air using the hot air devices 310, 320, 330, and 340.

[0046] The hot air devices 310, 320, 330, and 340 can inject hot air.

[0047] The hot air devices 310, 320, 330, and 340 may at least include main bodies 311, 321, 331, and 341 and nozzles 312, 322, 332, and 342.

[0048] The hot air devices 310, 320, 330, and 340 can control the hot air and the nozzles 312, 322, 332, and 342. For example, the hot air devices 310, 320, 330, and 340 can adjust at least one of the temperature, pressure, and injection time of the hot air. Another example is that the hot air devices 310, 320, 330, and 340 can also control the nozzles 312, 322, 332, and 342 to adjust the injection angle.

[0049] The angles of the nozzles 312, 322, 332, 342 with respect to the main bodies 311, 321, 331, 341 can be variable. For example, as the hot air devices 310, 320, 330, 340 adjust the injection angles of the nozzles 312, 322, 332, 342, the angles of the nozzles 312, 322, 332, 342 with respect to the main bodies 311, 321, 331, 341 can change.

[0050] The hot air devices 310, 320, 330, 340 can inject hot air into the corner portions 301, 302, 303, 304 of the electrode assembly 100 using the nozzles 312, 322, 332, 342. For example, the hot air devices 310, 320, 330, 340 can adjust at least one of the temperature, pressure, and injection time of the injected hot air, and the hot air devices 310, 320, 330, 340 can inject hot air with at least one of the temperature, pressure, and injection time adjusted into the corner portions 301, 302, 303, 304. Another example is that the hot air devices 310, 320, 330, 340 can adjust the injection angle so that the nozzles 312, 322, 332, 342 face the corner portions 301, 302, 303, 304, and the hot air devices 310, 320, 330, 340 can inject hot air into the corner portions 301, 302, 303, 304 through the nozzles 312, 322, 332, 342 at the adjusted injection angle.

[0051] The adjustment (or control) of the hot air of the hot air devices 310, 320, 330, 340 and the nozzles 312, 322, 332, 342 may be performed in real time even during the injection of the hot air.

[0052] The hot air devices 310, 320, 330, 340 (or the main bodies 311, 321, 331, 341) may be electrically connected to a driving device. For example, the control of the hot air of the hot air devices 310, 320, 330, 340 and the nozzles 312, 322, 332, 342 described above may be performed by the driving device.

[0053] The corner portions 301, 302, 303, and 304 may include a part of the separation membrane 130, and a part of the separation membrane 130 may be sealed by hot air. For example, a part of the separation membrane 130 may be melted by hot air, and the melted part of the separation membrane 130 may be crimped, and the corner portions 301, 302, 303, and 304 of the electrode assembly 100 may be sealed.

[0054] As described above, the sealing device can non - contact seal a part of the separation membrane 130 corresponding to the corner portions 301, 302, 303, and 304 of the electrode assembly 100 using the hot air devices 310, 320, 330, and 340, and can minimize damage to the electrodes and other components during the non - contact sealing process.

[0055] FIG. 3 shows some steps of the sealing method of the electrode assembly according to an embodiment of the present invention.

[0056] The electrode assembly 100 may be in a state of being seated on the nest 10.

[0057] The electrode assembly 100 may include electrodes including a plurality of negative electrodes 110 and a plurality of positive electrodes 130 alternately stacked with the separation membrane 120 interposed therebetween.

[0058] The electrode assembly 100 may include a plurality of corner portions 301, 302, 303, and 304. For example, the electrode assembly 100 may include a first corner portion 301, a second corner portion 302, a third corner portion 303, and a fourth corner portion 304.

[0059] The plurality of corner portions 301, 302, 303, and 304 may include a part of the separation membrane 120. More specifically, the separation membrane 120 may protrude outside the negative electrode 110 and the positive electrode 130 to form the peripheral edge of the electrode assembly 100, particularly the plurality of corner portions 301, 302, 303, and 304.

[0060] For example, the first corner portion 301 may include a portion corresponding to the first corner portion 301 in the separation membrane 120. For another example, each of the second corner portion 302, the third corner portion 303, and the fourth corner portion 304 may include a portion corresponding to the second corner portion 302, the third corner portion 303, and the fourth corner portion 304 in the separation membrane 120.

[0061] The hot air devices 310, 320, 330, 340 may standby (or, be prepared) at positions corresponding to the plurality of corner portions 301, 302, 303, 304. For example, the first hot air device 310 and the second hot air device 320 may standby at positions corresponding to a standby line (for example, line A). For another example, the third hot air device 330 and the fourth hot air device 340 may standby at positions corresponding to a standby line (for example, line A'). The above-described standby lines are examples, and each of the hot air devices 310, 320, 330, 340 may be located separated from the plurality of corner portions 301, 302, 303, 304 and is not limited to the above examples.

[0062] FIG. 4 shows a sealing stage of a sealing method for an electrode assembly according to an embodiment of the present invention.

[0063] The hot air devices 310, 320, 330, 340 can move so as to be close to the plurality of corner portions 301, 302, 303, 304 at positions (or, standby positions) corresponding to standby lines (for example, line A, line A').

[0064] The sealing device can move each of the hot air devices 310, 320, 330, 340 close to a plurality of corner portions 301, 302, 303, 304 by using a driving device. For example, the sealing device can move the first hot air device 310 and the second hot air device 320 from a position corresponding to line A to a position corresponding to line B by using a driving device. As another example, the sealing device can move the third hot air device 330 and the fourth hot air device 340 from a position corresponding to line A' to a position corresponding to line B' by using a driving device. The above description regarding the positions is merely illustrative and not limited thereto.

[0065] The sealing device can control the driving device or the hot air devices 310, 320, 330, 340 to adjust at least one of the temperature, pressure, and injection time of the hot air ejected from the nozzles 312, 322, 332, 342. For example, the sealing device can control the driving device or the hot air devices 310, 320, 330, 340 to adjust the temperature, pressure, and injection time of the hot air required for sealing, and can satisfy the conditions necessary for sealing.

[0066] The sealing device can also control the driving device or the hot air devices 310, 320, 330, 340 to adjust the injection angle at which the nozzles 312, 322, 332, 342 eject hot air. For example, the electrode assembly 100 may include a long side formed parallel to the first direction and a short side formed in a second direction perpendicular to the first direction. The sealing device can control the driving device or the hot air devices 310, 320, 330, 340 to control the injection angle of the nozzles 312, 322, 332, 342 so that hot air is ejected in a third direction at an angle with respect to the first direction and the second direction. As another example, the sealing device can control the driving device or the hot air devices 310, 320, 330, 340 to control the injection angle of the nozzles 312, 322, 332, 342 so that hot air is ejected in an oblique direction with respect to the plurality of corner portions 301, 302, 303, 304.

[0067] The sealing device can control the driving device to adjust (or set) the distances between a plurality of corner portions 301, 302, 303, 304 and each of the hot air devices 310, 320, 330, 340. For example, the sealing device can control the driving device to adjust the distance between the first hot air device 310 and the first corner portion 301, the distance between the second hot air device 320 and the second corner portion 302, the distance between the third hot air device 330 and the third corner portion 303, and the distance between the fourth hot air device 340 and the fourth corner portion 304.

[0068] When there is a preset distance value, the sealing device can control the driving device so that the distances between a plurality of corner portions 301, 302, 303, 304 and each of the hot air devices 310, 320, 330, 340 become the preset distance value.

[0069] The hot air devices 310, 320, 330, 340 can inject hot air at specific positions close to the plurality of corner portions 301, 302, 303, 304. For example, when the distances from the corner portions 301, 302, 303, 304 and the injection angles of the nozzles 312, 322, 332, 342 are adjusted, the sealing device can inject hot air toward the corner portions 301, 302, 303, 304 based on the temperature, pressure, and injection time of the hot air set using the hot air devices 310, 320, 330, 340.

[0070] A part of the separation film 130 may be included in the corner portions 301, 302, 303, 304, and a part of the separation film 130 may be sealed in a non-contact manner by hot air. For example, a part of the separation film 130 may be melted by hot air, and a part of the melted separation film 130 may be crimped, and the corner portions 301, 302, 303, 304 of the electrode assembly 100 may be sealed.

[0071] Since the sealing device performs sealing in a non-contact manner using the hot air devices 310, 320, 330, 340, it is possible to minimize the impact and damage caused to the sealing target and the parts that are not the sealing area due to physical contact during sealing. Further, the sealing device adaptively ensures uniform and stable sealing quality by controlling the conditions under which sealing is performed, such as the temperature of the hot air, the injection pressure, the injection time, the injection angle, and the distance between the hot air devices 310, 320, 330, 340 and the corner portions 301, 302, 303, 304, according to the situation.

[0072] FIG. 5 shows some steps of the sealing method of the electrode assembly according to an embodiment of the present invention.

[0073] The sealing device can control the driving device to readjust (or reset) the distances between the plurality of corner portions 301, 302, 303, 304 and each of the hot air devices 310, 320, 330, 340. For example, the sealing device can control the driving device to return the hot air devices 310, 320, 330, 340 to their original positions.

[0074] The sealing device can use the driving device to move each of the hot air devices 310, 320, 330, 340 away from the plurality of corner portions 301, 302, 303, 304. For example, the sealing device can use the driving device to move the first hot air device 310 and the second hot air device 320 from the position corresponding to the B line to the position corresponding to the A line. As another example, the sealing device can use the driving device to move the third hot air device 330 and the fourth hot air device 340 from the position corresponding to the B' line to the position corresponding to the A' line.

[0075] The sealing device can control the driving device to move the hot air devices 310, 320, 330, 340 from the positions close to the plurality of corner portions 301, 302, 303, 304 to the positions (or standby positions) corresponding to the standby lines (for example, the A line, the A' line).

[0076] As described above, although the present invention has been described with reference to limited embodiments and drawings, the present invention is not limited thereto, and various modifications can be made by those having ordinary knowledge in the technical field to which the present invention pertains within the equivalent scope of the technical idea of the present invention and the claims described below.

Explanation of Reference Numerals

[0077] 10 Nest 100 Electrode Assembly 110 Negative Electrode 120 Separator 130 Positive Electrode 140 Negative Electrode Tab 141 Negative Electrode Lead 150 Positive Electrode Tab 151 Positive Electrode Lead 301 First Corner Portion 302 Second Corner Portion 303 Third Corner Portion 304 Fourth Corner Portion 310 First Hot Air Device 311 First Main Body 312 First Nozzle 320 Second Hot Air Device 321 Second Main Body 322 Second Nozzle 330 Third Hot Air Device 331 Third Main Body 332 Third Nozzle 340 Fourth Hot Air Device 341 Fourth Main Body 342 Fourth Nozzle

Claims

1. A sealing method for an electrode assembly including a plurality of electrodes alternately laminated with a separation membrane therebetween, comprising: a step of seating the electrode assembly in a nest; a step of spraying hot air toward a corner portion of the electrode assembly to perform sealing, wherein a part of the separation membrane is melted by the hot air, a part of the melted separation membrane is pressure-bonded, and the corner portion of the electrode assembly is sealed. A sealing method for an electrode assembly.

2. The step of performing the sealing is to spray the hot air onto the corner portion using a hot air device including a nozzle. The sealing method for an electrode assembly according to claim 1.

3. The hot air device is to adjust at least one of the temperature, pressure, injection time, and injection angle of the hot air. The sealing method for an electrode assembly according to claim 2.

4. Before the step of performing the sealing, the method further includes a step of moving the hot air device toward the corner portion of the electrode assembly using a driving device. The sealing method for an electrode assembly according to claim 2.

5. The driving device is to adjust the distance between the hot air device and the corner portion. The sealing method for an electrode assembly according to claim 4.

6. The electrode assembly includes a long side formed parallel to a first direction and a short side formed in a second direction perpendicular to the first direction, and includes a step of adjusting the injection angle of the hot air with respect to the first direction and the second direction. The sealing method for an electrode assembly according to claim 2.

7. There are a plurality of the corner portions, and the hot air is blown using the same number of hot air devices corresponding to the plurality of corner portions. The sealing method for an electrode assembly according to claim 2.

8. A method for manufacturing a secondary battery, including the sealing method for an electrode assembly according to any one of claims 1 to 7.

9. A sealing device for an electrode assembly including a plurality of electrodes alternately laminated with a separation membrane therebetween, comprising: a nest for supporting the electrode assembly; a hot air device for spraying hot air onto a corner portion of the electrode assembly to perform non-contact sealing of the corner portion, wherein a part of the separation membrane is melted by the hot air, a part of the melted separation membrane is pressure-bonded, and the corner portion of the electrode assembly is sealed. A sealing device.

10. The hot air device includes a main body, and a nozzle with a variable angle with respect to the main body. The sealing device according to claim 9.

11. The sealing device according to claim 10, further comprising a driving device for moving the hot air device relative to the corner portion.

12. The hot air device The sealing device according to claim 10, which adjusts at least one of the temperature, pressure, injection time, and injection angle of the hot air.

13. The electrode assembly includes a long side formed parallel to the first direction and a short side formed in a second direction perpendicular to the first direction. The sealing device according to claim 10, wherein the hot air device controls the nozzle to adjust the injection angle of the hot air with respect to the first direction and the second direction.

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