Device and method for folding a sealing portion of a pouch-type secondary battery

Abstract

The folding method according to the present invention is a method for folding a sealing part of a pouch-type secondary battery in which a sealing part protrudes in a lateral direction of a pouch incorporating an electrode assembly, and includes a sealing part heating step of heating the sealing part; and a folding step of pressing and folding the heated sealing part; wherein the heating step includes a non-contact heating step of using a heat lamp to irradiate light to the sealing part to heat it. The folding device according to the present invention is a folding device for a sealing part of a pouch-type secondary battery in which a sealing part protrudes in a lateral direction of a pouch incorporating an electrode assembly, and includes: a heating part for heating the sealing part; and a folding part for pressurizing and folding the heated sealing part; the heating part includes a heating lamp for irradiating light to the sealing part to heat it, and the heating lamps are respectively disposed above and below the sealing part, and heat the upper and lower surfaces of the sealing part simultaneously.

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0015836 filed on February 7, 2022, and all contents disclosed in the documents of that Korean patent application are incorporated herein by reference.

[0002] The present invention relates to a folding device and a folding method for folding a sealing part formed along a periphery of a pouch-type secondary battery, and more particularly to a folding device and a folding method for a sealing part of a pouch-type secondary battery, which can solve a problem in a conventional structure in which excessive pressure is applied to the sealing part, causing damage to the sealing part. [Background technology]

[0003] Demand for secondary batteries as an energy source in various fields, including personal portable terminals and electric vehicles, is rapidly increasing.

[0004] Unlike primary batteries, secondary batteries, which can be charged and discharged, are being developed not only for digital devices but also for transportation means such as electric vehicles.

[0005] Secondary batteries can be classified into various types according to the materials of the positive and negative electrodes and the external shapes. Among them, lithium secondary batteries using lithium compounds have a large capacity and a low self-discharge rate, and are therefore widely used as an alternative to conventional nickel-cadmium secondary batteries.

[0006] The lithium secondary battery can be manufactured in various shapes, typically a cylinder type, a prismatic type, or a pouch type.

[0007] Among these, the pouch-type secondary battery includes a pouch and an electrode assembly that is housed in the pouch and charges and discharges electrical energy.

[0008] The electrode assembly is constructed by alternately stacking negative and positive electrodes together with a separator, and an electrode tab consisting of a negative electrode tab protruding from the negative electrode and a positive electrode tab protruding from the positive electrode is joined to an electrode lead, and one end of the electrode lead is manufactured to protrude outside the pouch. In this case, depending on a manufacturing method of the positive and negative electrodes, the positive and negative electrode tabs may be disposed on opposite sides to each other or may be disposed spaced apart from each other on the same side.

[0009] Meanwhile, the pouch is manufactured in a structure that can be separated into two parts (for example, a structure that can be separated into an upper part and a lower part) so that it can cover and accommodate one side and the other side of the electrode assembly, and when the electrode assembly and electrolyte are loaded inside, the two separated parts are joined to form a sealing part 1.

[0010] For example, the pouch 2 may be manufactured such that the upper and lower portions each have a recessed groove of a predetermined size to accommodate the electrode assembly, and the periphery of the groove is flat along the periphery.

[0011] Therefore, when the upper and lower parts of the pouch 2 are closed after the electrode assembly is mounted, their peripheral edges come into contact with each other, and in that state, a sealing part 1 is formed along the peripheral edge of the pouch 2, where the two parts are heat-sealed to each other to seal.

[0012] Referring to Fig. 1, which shows a conventional method of folding a sealing part of a pouch-type secondary battery, a sealing part 1 of a pouch 2 is heated through heating blocks 3a and 3b. The heating blocks 3a and 3b are composed of an upper mold 3a and a lower mold 3b that can slide to move away from or close to each other, and the upper mold 3a and the lower mold 3b are provided in a heated state at a predetermined temperature.

[0013] When the sealing part 1 enters between the upper mold 3a and the lower mold 3b, the upper mold 3a and the lower mold 3b pressurize and heat the sealing part 1 from above and below to heat-seal the sealing part 1. Then, with the lower mold 3b supporting the sealing part 1 from below, the upper mold 3a slides in a lateral direction (left and right direction in FIG. 1) to fold the sealing part 1. Alternatively, the sealing part 1 may be folded by a separate folding device (not shown) after being removed from the heating block.

[0014] However, such a heating method using pressure from the upper and lower dies 3a and 3b could cause damage such as dielectric breakdown in the synthetic resin layer made of thermoplastic resin contained in the pouch 2. In addition, the heating blocks 3a and 3b have a problem in that temperature deviation occurs with repeated use, making it difficult to maintain sealing quality. Summary of the Invention [Problem to be solved by the invention]

[0015] Therefore, the main object of the present invention is to provide a folding device and a folding method for a sealing part of a pouch-type secondary battery that can solve the problem of damage to the synthetic resin layer due to pressure generated by direct contact when heating the sealing part and can heat the sealing part by maintaining a uniform temperature. [Means for solving the problem]

[0016] In order to achieve the above-mentioned object, the present invention provides a method and device for folding a sealing part of a pouch-type secondary battery in which a sealing part protrudes in a lateral direction (left and right direction in FIG. 2, etc.) along the periphery of a pouch incorporating an electrode assembly.

[0017] The folding method according to the present invention is a folding method for a sealing part of a pouch-type secondary battery, and includes a sealing part heating step of heating the sealing part; and a folding step of pressing and folding the heated sealing part; and the heating step includes a non-contact heating step of using a heat lamp to irradiate light to the sealing part to heat it.

[0018] The sealing portion includes a layer made of a thermoplastic resin, the thermoplastic resin being polypropylene.

[0019] The light emitted by the heat lamp is infrared light.

[0020] The heating step may further include a contact heating step of contacting a heated heating block with the sealing portion to heat the sealing portion.

[0021] The heating step is configured such that a contact heating step is performed followed by a non-contact heating step, or a non-contact heating step is performed followed by a contact heating step.

[0022] In this case, one of the contact heating step and the non-contact heating step is carried out first, and then a part of the folding step is carried out, and the other of the contact heating step and the non-contact heating step is carried out, and then the remaining part of the folding step is carried out.

[0023] The heating step is a non-contact heating step in which a heat lamp irradiates light onto the sealing portion to heat it, which is performed multiple times. After the non-contact heating step is performed first, a part of the folding step is performed, and in that state, the non-contact heating step is performed again, and then the remaining part of the folding step is performed.

[0024] and a taping step of attaching a fixing tape to fix the folded sealing portion after the folding step is completed.

[0025] The folding device according to the present invention is a folding device for a pouch-type secondary battery sealing part in which a sealing part protrudes in a lateral direction of a pouch containing an electrode assembly, and includes a heating part for heating the sealing part and a folding part for pressing and folding the heated sealing part, and the heating part includes a heating lamp for irradiating light to the sealing part to heat it. In this case, the heating lamps are respectively disposed above and below the sealing part, and heat the upper and lower surfaces of the sealing part simultaneously.

[0026] The heating unit includes an upper mold and a lower mold that can slide between each other to move away from each other or to move closer to each other, at least one of the upper mold and the lower mold is heated to a predetermined temperature, and further includes a heating block that contacts and heats the sealing part when the sealing part enters between the upper mold and the lower mold. In this case, the heating lamp and the heating block are configured to be slidable so that their positions can be changed relative to each other.

[0027] The folding unit includes a fixing unit that fixes a folding point of the sealing unit when folding is performed, and a pressing unit that presses the sealing unit in a folding direction. Effect of the Invention

[0028] The present invention having the above technical features heats the sealing part by irradiating infrared rays to the sealing part using a heating lamp, eliminating the conventional problem of damage caused by pressure acting on the sealing part (due to direct contact with a heating block).

[0029] In addition, since the heating temperature can be maintained uniformly compared to the conventional contact heating method, the sealing quality of the sealing part can be maintained constant.

[0030] At the same time, in the present invention, contact heating may be performed by contacting a heated heating block with the sealing part to heat it, so that the sealing part can be heated by applying an appropriate pressure. In this case, since contact heating is performed before or after non-contact heating, the pressure applied to the sealing part can be lower than that of the conventional method, so that damage to the sealing part can be prevented. [Brief description of the drawings]

[0031] [Figure 1] 1 is a diagram showing a manner in which a sealing part of a pouch-type secondary battery is folded in a conventional manner; [Diagram 2] 13 is a view showing a manner in which a sealing part of a pouch-type secondary battery is folded while non-contact heating is performed in the heating step according to the present invention; FIG. [Diagram 3] 3 is a diagram showing a manner in which the next step is performed after the step shown in FIG. 2 is performed. [Figure 4] FIG. 3 is a diagram showing a state in which the folding of the sealing portion is performed through steps similar to those of FIG. 2, contact heating is performed in the first heating step, and non-contact heating is performed in the second heating step. [Diagram 5] FIG. 3 is a diagram showing a state in which the folding of the sealing portion is performed through steps similar to those of FIG. 2, non-contact heating is performed in the first heating step, and contact heating is performed in the second heating step. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0032] DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will now be described in detail with reference to the accompanying drawings in order to enable those skilled in the art to easily carry out their practice of the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments set forth herein.

[0033] In order to clearly describe the present invention, parts that are not relevant to the description will be omitted, and the same reference numerals will be used throughout the specification to refer to the same or similar components.

[0034] Furthermore, the terms and words used in this specification and the claims should not be interpreted limited to their ordinary and dictionary meanings, but should be interpreted in a way that is consistent with the technical ideas of the present invention, based on the principle that the inventor himself / herself can appropriately define the concepts of terms in order to explain the invention in the best possible manner.

[0035] The present invention relates to a method and device for folding a sealing part of a pouch-type secondary battery in which a sealing part 1 protrudes in a lateral direction (left and right direction in FIG. 2) along a periphery of a pouch 2 incorporating an electrode assembly. Hereinafter, an embodiment of the present invention will be described in more detail with reference to the accompanying drawings.

[0036] First embodiment The present invention provides a method for folding the sealing portion 1 of a pouch-type secondary battery as a first embodiment.

[0037] The folding method according to the present invention includes a heating step and a folding step, and the heating step includes a non-contact heating step in which no direct contact occurs between the sealing part 1 and a heat source.

[0038] The heating step is a process of heating the sealing part 1 to a predetermined temperature, and is performed at least twice during the folding method provided in this embodiment, and at least one of the heating steps is a non-contact heating step of irradiating light to the sealing part 1 with a heating lamp 11 to heat it. The heating lamp 11 described here is regarded as being capable of providing an output capable of heating the sealing part 1 to a predetermined temperature and irradiating light evenly to the entire sealing part 1 so that the heating lamp 11 can heat the sealing part 1 with radiant heat.

[0039] FIG. 2 is a diagram showing a state in which the sealing part of the pouch-type secondary battery is folded in a state in which non-contact heating is performed in the heating step according to the present invention. , First folding stage , 2nd folding stage <c>, 2nd heating stage <d>FIG. 3 shows the process of folding the stencil sheet 10 after the process shown in FIG. 2 is completed. <e>, 4th folding stage <f>, Taping stage <g>) is performed.

[0040] As shown in the drawings, in the folding method according to the present invention, each of the heating step and the folding step is repeated multiple times.

[0041] First heating stage< / g> < / f> < / e> < / d> < / c> This is done with the sealing part 1 open flat. Heating lamps 11 are arranged on the upper and lower sides of the sealing part 1, and infrared rays are irradiated onto the upper and lower surfaces of the sealing part 1 to heat the sealing part 1 to a predetermined temperature.

[0042] Meanwhile, the infrared rays irradiated in this embodiment are preferably near-infrared rays belonging to the shortest wavelength region. Near-infrared rays are infrared rays having a wavelength in the range of 750 nm to 4 μm, and have the advantage that heating can be performed in a relatively short time compared to mid-infrared rays and far-infrared rays, and the stability of the worker can be ensured even during long-term exposure. Heating can be performed by irradiating ultraviolet rays having a shorter wavelength instead of infrared rays, but when ultraviolet rays are used, the stability of the worker cannot be guaranteed, so in this application, near-infrared rays that have high heating efficiency and can ensure stability are provided as a heat source. Therefore, the heating lamp may be a halogen lamp, an LED lamp, a diode lamp, or the like that can irradiate near-infrared rays.

[0043] In this case, the sealing part 1 includes a layer made of a thermoplastic resin, and the thermoplastic resin is polypropylene. Therefore, when heat is applied, the sealing part 1 becomes more flexible.

[0044] Then, when the sealing unit 1 is heated to a predetermined temperature, a folding step is performed. The folding step may be performed by a folding unit 20 included in a folding device, which will be described later.

[0045] The folding unit 20 includes fixing units 21, 23 for fixing the folding point of the sealing unit 1 when folding is performed, and pressure units 22, 24 for applying pressure to the sealing unit 1 in the folding direction. Thus, while the fixing units 21, 23 support the sealing unit in a fixed state, the pressure units 22, 24 slide to fold the sealing unit 1 at a predetermined point, thereby performing the folding step of the sealing unit 1.

[0046] In this case, the folding step may be performed in the order of the first folding step shown in FIG. 2 according to the length and thickness of the sealing part 1 and the number of folding steps. , 2nd folding stage <c>, and the third folding stage shown in FIG. <e>, 4th folding stage <f>That is, the folding step may be selectively omitted, repeated or added depending on the length and thickness of the sealing portion 1.

[0047] In addition, the fixing parts 21, 23 and the pressing parts 22, 24 may be provided with different types of devices in each folding stage. In order to fold the sealing part 1 at a right angle, the fixing part 21 is provided in the form of a plate having a slit or hole, and when the sealing part enters the slit or hole, the pressure part 22 slides vertically to fold the sealing part at a 90° angle.

[0048] In the second folding step, the fixing part 23 may be provided (in the form of a plate or block) to support the underside of the sealing part 1 so that the sealing part 1 can be folded at an angle of 180°, and the pressure part 24 may slide horizontally (left and right in FIG. 2) on the fixing part 23 to fold the sealing part 1 at an angle of 180°.

[0049] If the sealing part 1 cools down to a certain temperature or lower during the folding step, the second heating step is started. <d>will be carried out.

[0050] Then the first folding stage The third folding step is carried out in a similar manner. <e>After the above, a fourth folding step is performed to maintain the pattern of the folded part or to adjust the folding angle. <f>is selectively performed.

[0051] Finally, after the folding step is completed, a taping step is performed in which a fixing tape 30 is attached so as to fix the folded sealing portion.

[0052] Meanwhile, in this embodiment, it has been described that two heating steps are performed during the folding step, but the heating step may be performed only once or additionally as necessary during the folding step.

[0053] However, at least one of the multiple heating steps is a non-contact heating step in which the heating lamp 11 irradiates the sealing portion 1 with light to heat it (in this case, if the heating step is performed once, it is a non-contact heating step).

[0054] However, in order to apply an appropriate pressure when heating the sealing portion 1, the heating step may further include a contact heating step of contacting the heating blocks 12a and 12b with the sealing portion 1 to heat it.

[0055] That is, the heating step provided in this embodiment is configured such that a contact heating step is performed followed by a non-contact heating step, or a non-contact heating step is performed followed by a contact heating step.

[0056] In this case, one of the contact heating step and the non-contact heating step is carried out first, and then a part of the folding step is carried out, and the other of the contact heating step and the non-contact heating step is carried out, and then the remaining part of the folding step is carried out.

[0057] FIG. 4 is a diagram showing a state in which the sealing portion is folded through the same steps as FIG. 2, contact heating is performed in the first heating step, and non-contact heating is performed in the second heating step. FIG. 5 is a diagram showing a state in which the sealing portion is folded through the same steps as FIG. 2, non-contact heating is performed in the first heating step, and contact heating is performed in the second heating step.

[0058] That is, the heating step may be performed multiple times. As shown in FIG. 4, a contact heating step using heating blocks 12a and 12b may be performed first, and then a part of the folding step may be performed. In this state, a non-contact heating step may be performed in which heating lamps 11 irradiate light to the sealing part 1 to heat it, and then the remaining steps of the folding step may be performed in sequence.

[0059] Alternatively, as shown in FIG. 5, a non-contact heating step may be performed first, and then a portion of the folding step may be performed, and in that state, a contact heating step may be performed again, and then the remaining part of the folding step may be performed.

[0060] That is, the folding method provided in the first embodiment may include one or more non-contact heating steps while multiple heating steps are performed, and may also include a contact heating step selectively.

[0061] Second embodiment The present invention provides a device for folding a sealing part 1 of a pouch-type secondary battery as a second embodiment. The folding device according to the present invention is a folding device for a sealing part of a pouch-type secondary battery in which a sealing part protrudes in a lateral direction of a pouch incorporating an electrode assembly, and includes a heating unit and a folding unit 20.

[0062] The heating unit is configured to heat the sealing unit 1 at a predetermined temperature and includes heating lamps 11 that irradiate light to the sealing unit 1 to heat it, and the heating lamps 11 are disposed on the upper and lower sides of the sealing unit 1, respectively, to heat the upper and lower surfaces of the sealing unit 1 simultaneously.

[0063] More specifically, the heating unit provided in this embodiment may further include heating blocks 12a and 12b in addition to the heating lamp 11 for irradiating light to heat the sealing unit.

[0064] The heating blocks 12a and 12b include an upper mold 12a and a lower mold 12b that can slide to move away from or toward each other, and at least one of the upper mold 12a and the lower mold 12b is heated to a predetermined temperature, and when the sealing part 1 enters between the upper mold 12a and the lower mold 12b, it comes into contact with the sealing part 1 and heats it. At this time, the upper mold 12a and the lower mold 12b may apply an appropriate pressure to the sealing part 1.

[0065] The heating lamp 11 and the heating blocks 12a, 12b are configured to be slidable so that their positions relative to each other can be changed.

[0066] At the same time, the folding unit 20 is configured to pressurize and fold the heated sealing unit 1. As described above, the folding unit includes fixing units 21 and 23 that fix the folding point of the sealing unit when folding is performed, and pressing units 22 and 24 that pressurize the sealing unit 1 in the folding direction.

[0067] The fixing parts 21, 23 may be provided in the form of a plate having a slit or hole for the sealing part to enter (as described above) so as to efficiently fix the sealing part according to the length, thickness and number of folding of the sealing part 1. Alternatively, the fixing parts may be provided in the form of a plate or block to support the bottom surface while the sealing part is folded 180°.

[0068] The pressure members 22, 24 may be configured to slide so that appropriate pressure can be applied in various directions so that folding can be performed according to the rotational position of the sealing unit 1.

[0069] The present invention having the above-mentioned technical features can solve the problem of the conventional method in which pressure acts on the sealing part 1, causing damage, by irradiating infrared rays to the sealing part 1 using the heating lamp 11 to heat it.

[0070] Also, since the heating temperature can be maintained uniformly compared to the conventional contact heating method, the sealing quality of the sealing part 1 can be maintained constant.

[0071] At the same time, in the present invention, contact heating may be performed by contacting the heated heating blocks 12a and 12b with the sealing part 1 to heat it, so that the sealing part 1 can be heated by applying an appropriate pressure. In this case, since the contact heating is performed before or after the non-contact heating, the pressure applied to the sealing part 1 can be lower than that of the conventional method. Therefore, damage to the sealing part can be prevented.

[0072] Although the present invention has been described above using limited embodiments and figures, the present invention is not limited thereto, and various implementations are possible within the technical spirit of the present invention and the equivalent scope of the claims described below by a person having ordinary skill in the art to which the present invention pertains. [Explanation of symbols]

[0073] 1 Sealing part 11 Heat Lamp 12a upper mold 12b Lower mold 20 Folding section 21, 23 Fixed part 22, 24 Pressurizing section< / f> < / e> < / d> < / f> < / e> < / c>

Claims

1. A method for folding a sealing part of a pouch-type secondary battery in which a sealing part protrudes in a lateral direction of a pouch containing an electrode assembly, comprising: a sealing portion heating step of heating the sealing portion; and a folding step of pressing and folding the heated sealing portion, The method for folding a sealing part of a pouch-type secondary battery, wherein the heating of the sealing part includes a non-contact heating step of using a heat lamp to irradiate light to the sealing part to heat it.

2. The method of claim 1 , wherein the sealing part includes a layer made of a thermoplastic resin.

3. The method for folding a sealing part of a pouch-type secondary battery according to claim 2 , wherein the thermoplastic resin is polypropylene.

4. The method for folding a sealing part of a pouch-type secondary battery according to claim 1 , wherein the light irradiated by the heat lamp is infrared light.

5. The method of claim 1 , wherein the heating of the sealing part comprises a contact heating step of contacting a heated heating block with the sealing part to heat the sealing part.

6. The method of claim 5 , wherein the heating of the sealing part is performed by performing a contact heating step and then a non-contact heating step.

7. The method of claim 5, wherein the heating of the sealing part is performed by a contact heating step after a non-contact heating step.

8. Either the contact heating step or the non-contact heating step is performed first, and then a part of the folding step is performed, 8. The method of claim 6, wherein the remaining process of the folding step is performed after the other of the contact heating step and the non-contact heating step is performed.

9. The heating step of the sealing part includes a non-contact heating step in which the heating lamp irradiates the sealing part with light to heat the sealing part, the non-contact heating step being performed multiple times, 2. The method of claim 1, wherein the non-contact heating step is performed first, and then a part of the folding step is performed, and in that state, the non-contact heating step is performed again, and then the remaining part of the folding step is performed.

10. The method for folding a sealing part of a pouch-type secondary battery according to any one of claims 1 to 7 and 9, further comprising a taping step of attaching a fixing tape to fix the folded sealing part after the folding step is completed.

11. A device for folding a sealing part of a pouch-type secondary battery, the sealing part of which is protruded in a lateral direction of a pouch containing an electrode assembly, A heating unit that heats the sealing unit; a folding unit that pressurizes and folds the heated sealing unit; The heating unit includes a heating lamp for irradiating light to the sealing unit to heat it.

12. The heating unit includes: The sealing device further includes an upper mold and a lower mold that are slidable between each other to move away from each other or to approach each other, at least one of the upper mold and the lower mold is heated at a predetermined temperature, and further includes a heating block that contacts and heats the sealing part when the sealing part enters between the upper mold and the lower mold, The folding device for a sealing part of a pouch-type secondary battery according to claim 11 , wherein the heating lamp and the heating block are slidable so as to change their positions relative to each other.

13. The folding portion is A fixing part for fixing a folding point of the sealing part when folding is performed; The folding device for a sealing part of a pouch-type secondary battery according to claim 11 or 12, further comprising: a pressurizing unit that presses the sealing part in a folding direction.

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