Pouch cell sealing apparatus including stopper and pouch cell sealing method using the same

Abstract

The present invention relates to a pouch cell sealing apparatus including a stopper, which is capable of adjusting a sealing thickness after sealing an outer edge of a cell case made of a laminated sheet by applying heat and pressure to the outer edge of the cell case when a pouch cell is manufactured, and a pouch cell sealing method using the same.

Description

Technical Field

[0001] This application claims priority to Korean Patent Application No. 2020-0146813, filed on November 5, 2020, the entire contents of which are incorporated herein by reference.

[0002] This invention relates to a pouch battery sealing device including a stop and a method for sealing a pouch battery using the same device. More specifically, this invention relates to a pouch battery sealing device including a stop and a method for sealing a pouch battery using the same device, which allows for adjusting the seal thickness after sealing during the manufacturing process of a pouch battery by applying heat and pressure to the outer edge of the battery casing, which is made of laminated sheet material. Background Technology

[0003] The demand for secondary batteries, which serve as energy sources for mobile devices, electric vehicles, and the like, is increasing dramatically. In particular, there is a high demand for lithium-ion secondary batteries with high energy density and high discharge voltage.

[0004] Based on their shape and materials, lithium-ion batteries can be categorized into cylindrical batteries made of metallic materials, prismatic batteries made of metallic materials, and pouch batteries made of laminated sheets. Pouch batteries offer advantages such as high energy density per unit weight due to their high-integrity stacking, low manufacturing cost, and ease of deformation. Therefore, pouch batteries are used in a variety of devices.

[0005] In pouch cells, a laminated sheet comprising an outer coating, a metal barrier layer, and an inner adhesive layer is typically formed to serve as the cell housing. Electrode assemblies, along with the electrolyte, are housed within a housing formed in the laminated sheet, and the housing is hermetically sealed to manufacture the pouch cell.

[0006] like Figure 1 As shown, the pouch battery 50 is configured to have an electrode assembly 20 mounted in a receiving portion 13 of a battery housing 10 formed by a lower pouch portion 11 and an upper pouch portion 12. In the electrode assembly 20, a positive electrode contact 21 and a negative electrode contact 22 are respectively welded to two electrode leads 31 and 32 and exposed outwards from the battery housing 10. With insulating films 41 and 42 disposed on the upper and lower surfaces of the electrode leads 31 and 32, the outer edge of the battery housing 10 is hermetically sealed.

[0007] As the inner adhesive layer of the laminated sheet is heated and melted and pressed by a longitudinally elongated cuboid sealing tool, the outer edge of the battery casing 10 is hermetically sealed.

[0008] Figure 2This is an exploded perspective view of a pouch-shaped battery sealing device 500 according to Patent Document 1. The outer edge of the pouch-shaped battery is positioned between a retainer 100 and a sealing block 200. The retainer 100, configured to move up and down via a lifting device 110, heats and fuses the outer edge of the pouch-shaped battery as it moves downward, thereby achieving an airtight seal. Since there is no separate spacing or distance control device between the retainer 100 and the sealing block 200, the pressure applied to the pouch-shaped battery varies depending on the pressure applied by the lifting device 110. If excessive pressure is applied, a thermal deformation problem occurs, i.e., the inner adhesive layer of the laminated sheet melts and bulges outward.

[0009] In Patent Document 1, to solve this problem, a spacer member 300 is inserted so that a uniform distance is maintained between the retainer 100 and the sealing block 200, thereby solving the problem of thermal deformation.

[0010] As a result of ongoing investigation into the aforementioned sealing issues, the inventors have discovered that the distance between the retainer 100 and the sealing block 200 is one of the most fundamental factors in sealing a pouch cell. The inventors have also found that the defect rate can be significantly reduced while simultaneously increasing the sealing strength by adjusting the distance between them. Even a change of only a few micrometers in the distance between the retainer 100 and the sealing block 200 can result in a substantial difference in sealing strength and, based on this, the defect rate.

[0011] The distance, which is a sensitive response variable, is also affected by various factors, including whether electrode leads are provided, the type and thickness of the metal barrier layer of the laminate, the thickness and composition of the inner adhesive layer of the laminate, the thickness and composition of the insulating film, and the temperature of the retainer and the sealing block. The distance between the retainer 100 and the sealing block 200 needs to be adjusted based on these factors.

[0012] As can also be seen from Patent Document 1, this problem was not recognized, and the spacer 100 and the sealing block 200 were spaced apart by a predetermined distance solely to address the issue of thermal deformation. Therefore, in the conventional technology, including Patent Document 1, only spacer members of fixed dimensions are used.

[0013] As previously stated, the inventors have discovered that the distance between the retainer 100 and the sealing block 200 is a very important factor in sealing, and that the defect rate can be greatly reduced when various sealing distances based on various process conditions are provided for this purpose.

[0014] In the initial stages, the inventors attempted to manufacture spacers of various heights and use them to check distance-based sealing results. However, the inventors discovered that it was physically nearly impossible to experiment using spacers typically made of metallic materials and manufactured to differ from each other on a micrometer scale, and the present invention was derived in the process of solving this problem.

[0015] Patent Document 2 relates to a battery module manufacturing method and an instrument characteristic measuring device. Patent Document 2 includes a step of measuring the correspondence between a load applied between a first circumferential surface of a battery cell and a second circumferential surface of the battery cell opposite to the first circumferential surface, and the distance between the first and second circumferential surfaces; a step of calculating the distance between the first and second circumferential surfaces based on the measured correspondence, where a first load is preset according to the measured correspondence; and a step of inserting the battery cell between a base contacting the first circumferential surface and a support plate contacting the second circumferential surface, and mounting the support plate to the base, with the distance between the first and second circumferential surfaces set to a desired distance between them.

[0016] In Patent Document 2, under the condition of added load, the battery cell is compressed between the first circumferential surface and the second circumferential surface, and a core is formed between the first circumferential surface and the second circumferential surface to adjust the distance between the first circumferential surface and the second circumferential surface; however, there is no structure for measuring the movement to calculate the precise distance, which is one of the structures according to the present invention used to solve this problem.

[0017] Patent Document 3 relates to an apparatus and method for measuring the thickness of a secondary battery cell. Patent Document 3 includes: a mounting platform on which a secondary battery cell of thickness to be measured is placed; a pressure plate opposite the mounting platform, wherein the pressure plate is mounted such that the distance between the pressure plate and the mounting platform is variable, with the secondary battery cell positioned between the mounting platform and the pressure plate; a pressure applying device configured to push or pull the pressure plate toward or from the mounting platform to apply pressure to the secondary battery cell placed on the mounting platform in the thickness direction of the mounting platform; a measuring device configured to measure the pressure applied to the pressure plate by the pressure applying device and the thickness of the secondary battery cell at time intervals; and a controller configured to control the charging, discharging, or temperature of the secondary battery cell according to measurement conditions input by an operator, receive measured pressure values ​​and measured thickness values ​​from the measuring device at time intervals, determine the magnitude of the pressure applied to the pressure plate and the thickness of the secondary battery cell, store the determined pressure magnitude and the determined thickness of the secondary battery cell together with time information in a memory, and maintain or change the pressure applied to the pressure plate by the pressure applying device during the measurement of the thickness of the secondary battery cell.

[0018] Patent document 3 only relates to a device for measuring the thickness of a secondary battery cell, and therefore cannot be considered a solution to the problem to be solved by the present invention.

[0019] Patent document 4 relates to a clamping device for stacking electrochemical cells, and patent document 5 relates to a battery cell pressing device and a battery cell pressing method using the battery cell pressing device. These patent documents do not describe whether distance is measured.

[0020] As mentioned above, a measuring device and a measuring method using the measuring device that can precisely adjust the distance between the retainer and the sealing block when sealing a pouch cell have not yet been proposed, and such a measuring device is considered an important issue of the present invention.

[0021] Korean Patent Application Publication No. 2015-0025684 (March 11, 2015) (“Patent Document 1”)

[0022] Japanese Patent Application Publication No. 2019-185929 (October 24, 2019) (“Patent Document 2”)

[0023] Korean Patent Application Publication No. 2016-0063278 (June 3, 2016) (“Patent Document 3”)

[0024] Korean Patent Application Publication No. 2015-0141966 (December 21, 2015) (“Patent Document 4”)

[0025] Korean Patent Application Publication No. 2015-0089555 (August 5, 2015) (“Patent Document 5”) Summary of the Invention

[0026] Technical issues

[0027] The present invention addresses the aforementioned problems. The object of the present invention is to provide a pouch battery sealing device and a pouch battery sealing method using the sealing device. The pouch battery sealing device can precisely adjust the distance between the retainer and the sealing block and the degree of sealing based on the distance during the process of sealing the outer edge of the battery casing made of laminated sheet by applying heat and pressure during the manufacture of the pouch battery.

[0028] Technical solution

[0029] To achieve the above objectives, the present invention provides a pouch-shaped battery sealing device, comprising an upper sealing block, a lower sealing block, and a stop unit configured to maintain a minimum distance between the upper and lower sealing blocks, wherein the stop unit includes a stop configured to contact the upper sealing block to prevent downward movement of the upper sealing block; a support shaft disposed on at least one side of the upper sealing block, the support shaft being configured to allow the stop to support the upper sealing block while changing the position of the stop by vertical or rotational movement; a measuring unit configured to measure changes in the movement of the stop; and a height adjusting unit configured to adjust the position where the stop is fixed.

[0030] The stop unit can be symmetrically arranged on the left and right surfaces of the upper sealing block, and has the same structure.

[0031] The measuring unit can be a micrometer, configured to measure the upward and downward movement distance of the stop, and the height adjustment unit can adjust the height of the stop by rotating its threaded portion.

[0032] In another aspect, the pouch-shaped battery sealing device may also include a fixing part configured to fix the height adjustment part and the measuring part at a constant position relative to the lower sealing block.

[0033] The support shaft can be disposed between the upper sealing block and the measuring part and the height adjustment part. The support shaft can be disposed perpendicular to the plane of the fixed lower sealing block. The support shaft can be provided with a guide or a rotating shaft. The guide is configured to allow the stop to move horizontally along the support shaft, and the rotating shaft is configured to allow the stop to rotate around the support shaft.

[0034] The stop can be set on each of the left and right sides of the upper sealing block, and the left and right distances between the upper and lower sealing blocks can be fixed differently by the stop.

[0035] The stop can be set on each of the left and right sides of the upper sealing block, and the plane that fixes the upper sealing block can be tilted by the stop.

[0036] In another aspect, the present invention provides a method for adjusting the sealing thickness of a pouch battery using the pouch battery sealing device.

[0037] Furthermore, the present invention can provide all feasible combinations of the above-described solutions.

[0038] Beneficial effects

[0039] As can be clearly seen from the above description, the present invention provides a pouch battery sealing device and a pouch battery sealing method using the pouch battery sealing device. The pouch battery sealing device is capable of precisely adjusting the distance between the retainer and the sealing block and the degree of sealing based on the distance during the process of sealing the outer edge of the battery housing made of laminated sheet by applying heat and pressure to the outer edge of the battery housing during the manufacturing of the pouch battery.

[0040] In this invention, the height is precisely adjusted by the height adjustment unit, and the change in height is observed by the measuring unit. Therefore, the sealing distance can be adjusted precisely and consistently, thereby providing consistent results.

[0041] According to the present invention, the left and right stops are adjustable independently. Therefore, when the lower sealing block is not horizontal, the upper sealing block can be adjusted according to the state of the lower sealing block.

[0042] Each stop according to the invention has a constant position because its axis of rotation is fixed, and the upper sealing block is supported by the height adjustment part and the measuring part according to the lever principle, thereby achieving a very high fixing force and easy height adjustment. Attached Figure Description

[0043] Figure 1 This is an exploded perspective view of a traditional pouch battery.

[0044] Figure 2 This is an exploded perspective view of a pouch-shaped battery sealing device based on Patent Document 1.

[0045] Figure 3 a)-b) are cross-sectional views of a pouch-shaped battery sealing device according to a first embodiment of the present invention.

[0046] Figure 4 a)-b) are cross-sectional views illustrating a first operational example of a pouch-shaped battery sealing device according to a second embodiment of the present invention.

[0047] Figure 5 a)-b) are cross-sectional views illustrating a second operational example of the pouch-shaped battery sealing device according to a second embodiment of the present invention.

[0048] Figure 6 a)-b) are cross-sectional views illustrating a third operational example of the pouch-shaped battery sealing device according to a second embodiment of the present invention.

[0049] Figure 7 a)-b) are cross-sectional views illustrating a fourth operational example of the pouch-shaped battery sealing device according to a second embodiment of the present invention. Detailed Implementation

[0050] Preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, enabling those skilled in the art to readily implement these preferred embodiments. However, in describing the operational principles of the preferred embodiments in detail, detailed descriptions of known functions and configurations included herein will be omitted where such descriptions may obscure the subject matter of the invention.

[0051] Furthermore, the same reference numerals are used throughout the drawings to indicate parts that perform similar functions or operations. Where one part is referred to as being connected to another part throughout the specification, this means not only that the one part can be directly connected to the other part, but also that the one part can be indirectly connected to the other part via the other part. Additionally, including an element does not mean excluding other elements, but rather that these elements can be further included, unless otherwise specified.

[0052] Furthermore, unless otherwise specified, descriptions of elements by limiting or adding to them can be applied to all inventions and do not limit any particular invention.

[0053] Furthermore, in the description of the invention and the claims of this application, the singular form is intended to include the plural form, unless otherwise stated.

[0054] Furthermore, in the description and claims of this application, unless otherwise stated, "or" includes "and". Therefore, "including A or B" refers to three cases: including A, including B, and including both A and B.

[0055] In the following description, embodiments of the present invention will be described with reference to the accompanying drawings.

[0056] Figure 3 a)-b) are cross-sectional views of the pouch-shaped battery sealing device 5000 according to the first embodiment of the present invention, showing operational examples a) and b).

[0057] The pouch-shaped battery sealing device according to the invention includes an upper sealing block 5100, a lower sealing block 5200, and a left stop unit 5300 and a right stop unit 5400 configured to maintain a minimum distance between the upper sealing block 5100 and the lower sealing block 5200. Figure 3 a)-b) to Figure 7 In a)-b), the left stop unit and the right stop unit with the same structure are arranged symmetrically on the left and right sides.

[0058] The left stop unit 5300 and the right stop unit 5400 include: a left stop 5310 and a right stop 5410 configured to contact the upper sealing block 5100 to prevent the upper sealing block 5100 from moving downward; a left support shaft 5330 and a right support shaft 5430 disposed on at least one side of the upper sealing block 5100, the support shafts being configured to allow the left stop 5310 and the right stop 5410 to support the upper sealing block 5100, while changing the position of the left stop 5310 and the right stop 5410 by moving upward and downward; measuring units 5350 and 5450 configured to measure the movement changes of the left stop 5310 and the right stop 5410; and height adjusting units 5370 and 5470 configured to adjust the fixed position of the left stop 5310 and the right stop 5410.

[0059] Measuring units 5350 and 5450 are micrometers configured to measure the vertical movement distance of the left stop 5310 and the right stop 5410. Height adjusting units 5370 and 5470 adjust the height of the left stop 5310 and the right stop 5410 by rotating their threaded portions.

[0060] When the sealing distance used for pouch cells varies in micrometers, the degree of sealing and defect rate differ. A micrometer is used to measure the change in height.

[0061] In a first embodiment of the invention, the left stop 5310 and the right stop 5410 move vertically parallel to each other along the left support shaft 5330 and the right support shaft 5430. For this purpose, the left support shaft 5330 and the right support shaft 5430 are provided with guides (not shown) configured to allow the left stop 5310 and the right stop 5410 to move thereal.

[0062] Height adjustment parts 5370 and 5470 are threadedly engaged with through holes formed in the left stop 5310 and right stop 5410. When the threaded portions of the height adjustment parts 5370 and 5470 rotate, the left stop 5310 and right stop 5410 move upward and downward in response.

[0063] For this purpose, height adjustment units 5370 and 5470 and measuring units 5350 and 5450 are fixed to fixing units 5390 and 5490 so that they are located at a constant distance from the lower sealing block 5200. As a result, the height of the left stop 5310 and the right stop 5410 can be adjusted, and the change value for height adjustment can be accurately measured at the same time.

[0064] Figure 3 Figure b) of a)-b) shows that the upper sealing block 5100 and the lower sealing block 5200 are constantly adjusted by the left stop 5310 and the right stop 5410 so that there is a distance d5 between them.

[0065] Figure 4 a)-b) are cross-sectional views illustrating a first operational example 1000 of the pouch-shaped battery sealing device according to a second embodiment of the present invention. Figure 5 a)-b) are cross-sectional views illustrating a second operational example 2000 of the pouch-shaped battery sealing device according to a second embodiment of the present invention. Figure 6 a)-b) are cross-sectional views illustrating a third operational example 3000 of the pouch battery sealing device according to a second embodiment of the present invention. Figure 7 a)-b) are cross-sectional views showing a fourth operational example 4000 of the pouch battery sealing device according to a second embodiment of the present invention.

[0066] The pouch-shaped battery sealing device according to the first embodiment of the present invention and the pouch-shaped battery sealing device according to the second embodiment of the present invention differ from each other in terms of the movement of the stop members. In the first embodiment, the left stop member 5310 and the right stop member 5410 move upward and downward parallel to each other along the left support shaft 5330 and the right support shaft 5430.

[0067] In the second embodiment, the stop rotates about left rotation axes 1330, 2330, 3330, 4330 and right rotation axes 1430, 2430, 3430 and 4430 provided on the support shaft (not shown).

[0068] Unlike the first embodiment, in the second embodiment, the stop member performs a rotational motion. Therefore, instead of using the value measured by the measuring unit as is, the distance from the rotation axis is measured, and the distances d1, d2, d3, d4, d4L, and d4R between the upper and lower sealing blocks are calculated using their arithmetic expressions, or the distances d1, d2, d3, d4, d4L, and d4R between the upper and lower sealing blocks are calculated using the correlation between the value measured by the measuring unit and the actual measured distance between the upper and lower sealing blocks.

[0069] Figure 4 a)-b) show the upper sealing block 1100 fixed with both the left stop 1310 and the right stop 1410 horizontal. Figure 5 a)-b) show that the upper sealing block 2100 is fixed in a state where both the left stop 2310 and the right stop 2410 have moved downwards due to rotational motion. Figure 6 a)-b) show that the upper sealing block 3100 is fixed in a state where both the left stop 3310 and the right stop 3410 have moved upward due to rotational motion. Figure 7 a)-b) show that the upper sealing block 4100 is fixed with one of the left stop 4310 and the right stop 4410 moving upwards while the other moves downwards due to rotational motion. Therefore, even when the lower sealing block is not horizontal, the same distance is maintained. It can be seen that d4, d4L, and d4R are equal to each other.

[0070] Those skilled in the art will understand that, based on the above description, various applications and modifications are possible within the scope of this invention.

[0071] (Description of reference numerals in the attached figures)

[0072] 10: Battery casing

[0073] 11: Lower part

[0074] 12: Upper part

[0075] 13: Reception Department

[0076] 20: Electrode assembly

[0077] 21, 22: Electrode contacts

[0078] 31, 32: Electrode leads

[0079] 41, 42: Insulating film

[0080] 50: Pocket battery

[0081] 100: Holder

[0082] 110: Lifting device

[0083] 200: Sealing block

[0084] 300: Spacing member

[0085] 500: Traditional pouch battery sealing device

[0086] 1000: First operational example of the pouch-shaped battery sealing device according to the second embodiment of the present invention

[0087] 2000: A second operational example of the pouch-shaped battery sealing device according to a second embodiment of the present invention.

[0088] 3000: A third operational example of the pouch-shaped battery sealing device according to the second embodiment of the present invention.

[0089] 4000: Fourth operational example of the pouch-shaped battery sealing device according to the second embodiment of the present invention

[0090] 5000: Operational example of the pouch-shaped battery sealing device according to the first embodiment of the present invention

[0091] 1100, 2100, 3100, 4100, 5100: Upper sealing block

[0092] 1200, 2200, 3200, 4200, 5200: Lower sealing block

[0093] 1300, 2300, 3300, 4300, 5300: Left stop unit

[0094] 1400, 2400, 3400, 4400, 5400: Right stop unit

[0095] 1310, 2310, 3310, 4310, 5310: Left stop

[0096] 1410, 2410, 3410, 4410, 5410: Right stop

[0097] 1330, 2330, 3330, 4330: Left rotation axis

[0098] 1430, 2430, 3430, 4430: Right-hand rotation axis

[0099] 5330: Left support shaft

[0100] 5430: Right support shaft

[0101] 1350, 2350, 3350, 4350, 5350, 1450, 2450, 3450, 4450, 5450: Measurement Department

[0102] 1370, 2370, 3370, 4370, 5370, 1470, 2470, 3470, 4470, 5470: Height adjustment unit

[0103] 1390, 2390, 3390, 4390, 5390, 1490, 2490, 3490, 4490, 5490: Fixed parts

[0104] d1, d2, d3, d4, d4L, d4R, d5: Distances between the upper and lower sealing blocks.

[0105] Industrial applicability

[0106] This invention relates to a pouch battery sealing device including a stop and a method for sealing a pouch battery using the pouch battery sealing device. The pouch battery sealing device is capable of adjusting the seal thickness after sealing during the manufacturing process of a pouch battery by applying heat and pressure to the outer edge of the battery housing made of laminated sheet material. Therefore, this invention has industrial applicability.

Claims

1. A bag-shaped battery sealing device, comprising an upper sealing block, a lower sealing block, and a stop unit, the stop unit being configured to maintain a minimum distance between the upper sealing block and the lower sealing block, wherein, The stop unit includes: A stop is configured to contact the upper sealing block to prevent the upper sealing block from moving downward; A support shaft is disposed on at least one side of the upper sealing block, the support shaft being configured to allow the stop to support the upper sealing block while changing the position of the stop by vertical or rotational movement; The measuring unit is configured to measure the movement changes of the stop member; and The height adjustment unit is configured to adjust the position where the stop is fixed. The height adjustment part is threadedly connected to a threaded opening formed in the stop, and the height adjustment part is configured such that rotation of the height adjustment part causes the stop to move along the support shaft.

2. The pouch-shaped battery sealing device according to claim 1, wherein the stop unit is symmetrically arranged on the left and right surfaces of the upper sealing block and has the same structure.

3. The bag-shaped battery sealing device according to claim 1, wherein the measuring unit is a micrometer configured to measure the vertical movement distance of the stop member.

4. The bag-shaped battery sealing device according to claim 1, wherein, The height adjustment unit adjusts the height of the stop member by rotating the threaded portion of the height adjustment unit.

5. The pouch-shaped battery sealing device according to claim 1 further includes a fixing part configured to fix the height adjusting part and the measuring part at a constant position from the lower sealing block.

6. The bag-shaped battery sealing device according to claim 1, wherein the support shaft is disposed between the upper sealing block and the measuring part and the height adjusting part.

7. The pouch-shaped battery sealing device according to claim 1, wherein the support shaft is arranged perpendicular to the plane that fixes the lower sealing block.

8. The pouch-shaped battery sealing device of claim 7, wherein the support shaft is provided with a guide or a rotating shaft, the guide being configured to allow the stop to move horizontally along the support shaft, and the rotating shaft being configured to allow the stop to rotate about the support shaft.

9. The pouch-shaped battery sealing device according to claim 1, wherein... The stop is provided on each of the left and right sides of the upper sealing block, and The left and right distances between the upper sealing block and the lower sealing block are fixed differently by the stop.

10. The pouch-shaped battery sealing device according to claim 1, wherein... The stop is provided on each of the left and right sides of the upper sealing block, and The plane that fixes the upper sealing block is inclined by the stop.

11. A method for adjusting the sealing thickness of a pouch battery using the pouch battery sealing device according to any one of claims 1 to 10.

Images