Pouch sealing apparatus and pouch sealing method

Abstract

The pouch sealing device related to an embodiment of the present invention comprises: a sealing unit provided to seal a sealing target area of any one edge part among a plurality of edge parts of a pouch in which an electrode assembly is accommodated; a cooling unit provided to cool a cooling target area of the pouch positioned between the sealing target area and an inner space of the pouch in which the electrode assembly is accommodated; and a control unit provided to perform a sealing mode for heating the sealing target area through the sealing unit after completing a pre-cooling mode for cooling the cooling target area through the cooling unit.

Description

Pouch sealing device and pouch sealing method

[0001] The present invention relates to a pouch sealing device and a pouch sealing method, and more particularly, to a pouch sealing device and a pouch sealing method that pre-cool the periphery of a sealing target area of ​​a pouch requiring sealing and then seal the sealing target area.

[0002] This application claims the benefit of priority to Korean Patent Application No. 10-2023-0106025, filed August 14, 2023, the entire contents of which are incorporated herein by reference.

[0003] Figure 1 is a schematic diagram showing a conventional pouch sealing process.

[0004] As illustrated in FIG. 1, a secondary battery cell (10) includes an electrode assembly (20) and a pouch (30).

[0005] The above electrode assembly (20) may be formed in a laminated form with a separator interposed between one or more positive electrodes and one or more negative electrodes.

[0006] The above pouch (30) is a case for protecting the electrode assembly (20). The electrode assembly (20) is stored in the internal space (31) of the pouch (30). In addition, the pouch (30) has a sealed border (32) surrounding the internal space (31).

[0007] The edge portion (32) of the above pouch (30) is sealed by a sealing member (1) so that the internal space (31) of the pouch (30) is sealed. A sealing target area (60) sealed by the sealing member (1) is provided for each edge portion (32) of the pouch (30).

[0008] In addition, the sealing member (1) is provided to heat (Q) while pressurizing the sealing target area (60) to heat-seal the edge portion (32) of the pouch (30).

[0009] However, in the process of the sealing member (1) sealing the edge portion (32) of the pouch (30), the heat (Q) of the sealing member (1) is transferred to the periphery of the sealing target area (60). Due to the heat (Q) provided by the sealing member (1), the adhesive layer of the pouch (30) melts not only in the sealing target area (60) but also in the periphery of the sealing target area (60).

[0010] In particular, if the inner peripheral area (50) adjacent to the electrode assembly (20) among the peripheral areas of the sealing target area (60) is adhered by the heat (Q) of the sealing member (1), it may have a direct effect on the electrode assembly (20) and cause a defect in the battery cell (10).

[0011] The present invention aims to provide a pouch sealing device and a pouch sealing method that seal a sealing target area of ​​a pouch after pre-cooling the periphery of the sealing target area of ​​the pouch where sealing is required.

[0012] In addition, the present invention aims to provide a pouch sealing device and a pouch sealing method capable of preventing adhesion of the inner peripheral region of a pouch by heat conduction during sealing of the pouch by pre-cooling the inner peripheral region of the pouch extending from the sealing target region to the inner space of the pouch.

[0013] A pouch sealing device according to one embodiment of the present invention includes a sealing unit configured to seal a sealing target area of ​​one of a plurality of edge areas of a pouch containing an electrode assembly, a cooling unit configured to cool a cooling target area of ​​the pouch located between an internal space of the pouch containing the electrode assembly and the sealing target area, and a control unit configured to perform a sealing mode of heating the sealing target area through the sealing unit after completing a pre-cooling mode of cooling the cooling target area through the cooling unit.

[0014] Additionally, the cooling target area of ​​the pouch may extend from the sealing target area toward the inner space of the pouch.

[0015] Additionally, the cooling unit may include a first cooling member arranged parallel to the length direction of one edge of the pouch and provided so as to be in contact with the cooling target area.

[0016] Additionally, the first cooling member may include a Peltier element.

[0017] Additionally, the first cooling member may have a bar shape having a length longer than the length of the edge portion.

[0018] Additionally, the cooling unit may include a second cooling member arranged symmetrically with respect to the first cooling member with respect to the cooling target area.

[0019] Additionally, the first and second cooling members may be arranged to be movable toward or away from each other.

[0020] Additionally, the second cooling member may include a Peltier element.

[0021] Additionally, the second cooling member may have a bar shape having a length longer than the length of the edge portion.

[0022] Additionally, the first and second cooling members can be arranged symmetrically vertically with respect to the cooling target area.

[0023] In addition, the sealing portion may include first and second sealing members arranged symmetrically with respect to the sealing target area and arranged to heat the sealing target area upward and downward in the sealing mode.

[0024] Additionally, the first and second sealing members may be configured to seal one edge of the pouch in the form of a line having a predetermined width. Each sealing member may have a bar shape and may include a heater for applying heat to the sealing target area.

[0025] Additionally, the first and second sealing members may be spaced apart from the sealing target area of ​​the pouch in the pre-cooling mode of the cooling unit.

[0026] In addition, the first and second sealing members may have a bar shape having a length longer than the length of the edge of the pouch, and may be provided to be movable toward or away from each other.

[0027] Additionally, the control unit may be arranged to repeatedly perform the sealing mode after the pre-cooling mode for each edge of the pouch.

[0028] In addition, a pouch sealing method related to one embodiment of the present invention is a pouch sealing method using the pouch sealing device, including a pre-cooling step of cooling a cooling target area extending inwardly from one edge portion of the pouch, and a sealing step of sealing the sealing target area of ​​the edge portion after the pre-cooling is completed.

[0029] As described above, the pouch sealing device and pouch sealing method related to one embodiment of the present invention have the following effects.

[0030] Before sealing any one edge portion of the pouch, the inner peripheral area of ​​the pouch between the sealing target area to be sealed and the inner space of the pouch is pre-cooled to prevent heat from the sealing portion from being transferred to the inner peripheral area of ​​the pouch, thereby preventing damage to the pouch due to heat conduction of the sealing portion.

[0031] In addition, by pre-cooling the inner peripheral area of ​​the pouch as a cooling target area, only the sealing target area is thermally fused when sealing the pouch, and adhesion of the inner peripheral area of ​​the pouch can be prevented.

[0032] Figure 1 is a schematic diagram showing a conventional pouch sealing process.

[0033] Figure 2 is a configuration diagram of a pouch sealing device according to one embodiment of the present invention.

[0034] FIG. 3 is a plan view showing a cooling target area and a sealing target area of ​​a battery cell in one embodiment of the present invention.

[0035] Figure 4 is an operating state diagram of a cooling unit according to one embodiment of the present invention.

[0036] Figure 5 is a plan view showing a state in which the first cooling member is positioned in the cooling target area.

[0037] Figure 6 is an operating state diagram of a sealing part according to one embodiment of the present invention.

[0038] Fig. 7 is a plan view showing a state in which the first sealing member is positioned in the sealing target area of ​​the pouch.

[0039] Figure 8 is a plan view of a battery cell in which a long-side sealing line is formed.

[0040] Figures 9 to 11 are schematic diagrams for explaining the process of a pouch sealing device sealing a piercing portion provided in a gas pocket of a pouch in a gas removal process.

[0041] Referring to the attached drawings below, a pouch sealing device and a pouch sealing method according to one embodiment of the present invention will be described.

[0042] In addition, regardless of the drawing symbol, identical or corresponding components are given identical or similar reference numbers and redundant descriptions thereof are omitted, and for the convenience of explanation, the size and shape of each component depicted may be exaggerated or reduced.

[0043] FIG. 2 is a configuration diagram of a pouch sealing device according to one embodiment of the present invention, and FIG. 3 is a plan view showing a cooling target area and a sealing target area of ​​a battery cell according to one embodiment of the present invention.

[0044] A pouch sealing device (100) related to one embodiment of the present invention includes a sealing portion (130) provided to seal a sealing target area (60) of one of a plurality of edge portions (32) of a pouch (30) in which an electrode assembly (20) is stored.

[0045] In this document, the battery cell (10) is a secondary battery battery cell (10), which includes an electrode assembly (20), a pair of lead tabs (21) electrically connected to the electrode assembly (20), and a pouch (30) surrounding the electrode assembly (20).

[0046] As described through Fig. 1, the electrode assembly (20) may be formed in a laminated form with a separator interposed between one or more positive electrodes and one or more negative electrodes.

[0047] The above pouch (30) is a case for protecting the electrode assembly (20). The electrode assembly (20) is stored in the internal space (31) of the pouch (30). The pouch (30) has a plurality of border portions (32) provided to surround the internal space (31).

[0048] Each edge portion (32) of the pouch (30) is sealed by the sealing portion (130) so that the internal space (31) of the pouch (30) containing the electrode assembly (20) is sealed. The pouch (30) is formed of an aluminum material and may include an adhesive layer. The adhesive layer may be formed of a resin material (e.g., a polypropylene material), and when the adhesive layer is melted by the sealing portion (130), the edge portion (32) of the pouch (30) may be sealed.

[0049] Here, the plurality of edge portions (32) of the pouch (30) may include a long edge portion (33) or a short edge portion (34). For example, in the sealing mode of the pouch (30), a sealing process may be performed on each of one long edge portion (33) and a pair of cross-sectional edge portions (34).

[0050] In this document, the long edge portion (33) may be an edge portion extending along the direction (L) connecting a pair of lead tabs (21), and the short edge portion (34) may be an edge portion in which the lead tabs (21) protrude outside the pouch (30). Referring to Fig. 3, the edge portion parallel to the x-axis direction may be the long edge portion (33), and the edge portion parallel to the y-axis direction may be the short edge portion (34).

[0051] In addition, the pouch sealing device (100) can be used in a process of sealing the edge portion (32) of the pouch (30) after the electrode assembly (20) is housed in the internal space (31, cup portion) of the pouch (30) during the assembly step of the battery cell (10), or can be used in a process of sealing the piercing portion (40) provided in the gas pocket (39) of the pouch (30) after the activation process and gas removal process of the assembled battery cell (1) are performed.

[0052] Fig. 4 is a diagram showing the operation status of a cooling unit according to one embodiment of the present invention, and Fig. 5 is a plan view showing a state in which a first cooling member is positioned in a cooling target area.

[0053] In addition, the pouch sealing device (100) includes a cooling unit (110) provided to cool a cooling target area (50) located between the internal space (31) of the pouch (30) in which the electrode assembly (20) is stored and the sealing target area (60).

[0054] Additionally, the cooling target area (50) of the pouch (30) may extend from the sealing target area (60) toward the inner space (31) of the pouch (30).

[0055] The above cooling target area (50) may be an inner peripheral area of ​​the sealing target area (60) of the edge portion (32) of the pouch (30).

[0056] In addition, the pouch sealing device (100) includes a control unit (150) configured to perform a sealing mode in which the sealing target area (60) is heated through the sealing unit (130) after completing a pre-cooling mode in which the cooling target area (50) is cooled through the cooling unit (110).

[0057] In addition, FIG. 6 is a diagram showing the operating state of a sealing part according to one embodiment of the present invention, FIG. 7 is a plan view showing a state in which a first sealing member is seated in a sealing target area of ​​a pouch, and FIG. 8 is a plan view of a battery cell in which a long-side sealing line is formed.

[0058] Hereinafter, with reference to FIGS. 2 to 8, the process of sealing the edge portion (32) of the pouch (30) in the assembly step of the battery cell (10) will be described.

[0059] The above pouch sealing device (100) includes a cooling unit (110) that pre-cools the edge of the pouch (30) prior to the sealing process of the edge of the pouch (30).

[0060] The above cooling unit (110) is provided to cool a cooling target area (50) extending from a sealing target area (60) to the inside of a long edge portion (33) adjacent to the internal space (31) of a pouch (30) in which the electrode assembly (20) is stored.

[0061] Referring to FIGS. 2 and 3, the cooling target area (50) may be an inner peripheral area (50) between the internal space (31) and the sealing target area (60). The cooling target area (50) is an area to be cooled by the cooling unit (110).

[0062] In this specification, the cooling target area (50) refers to the same area as the inner peripheral area (50), and the same drawing number is used.

[0063] The cooling unit (110) includes a first cooling member (111) configured to cool the cooling target area (50). In addition, the first cooling member (111) is arranged parallel to the longitudinal direction of one of the edge portions (32). The first cooling member (111) may have a predetermined width (w1).

[0064] The first cooling member (111) is provided so as to be in contact with the cooling target area (50). The first cooling member (111) may have a bar shape having a length longer than the length of the edge portion (32) of the pouch (30). In addition, the first cooling member (111) may include a Peltier element. At this time, the Peltier element may include a heat absorbing portion and a heat generating portion, and the heat absorbing portion may be in contact with the cooling target area (50).

[0065] In addition, the cooling unit (110) may include a second cooling member (113) arranged symmetrically vertically with respect to the first cooling member (111) with respect to the cooling target area (50).

[0066] The second cooling member (113) may be configured in the same manner as the first cooling member (111). The second cooling member (113) may include a Peltier element. In this case, the Peltier element may include a heat absorbing portion and a heat generating portion, and the heat absorbing portion may be in contact with the cooling target area (50).

[0067] In addition, the first and second cooling members (111, 113) may be spaced apart from each other vertically in the stacking direction (Z) of the electrode assembly (20). In addition, the first and second cooling members (111, 113) are provided to be able to be raised and lowered along the stacking direction (Z) of the electrode assembly (20). The cooling unit (110) may include a first driving unit (170) for raising and lowering the first and second cooling members (111, 113). The first driving unit (170) may be configured to include a cylinder or a motor.

[0068] In addition, in the pre-cooling mode, the first and second cooling members (111, 113) can be moved to contact the cooling target area (50), respectively. Thereafter, the first and second cooling members (111, 113) can cool the cooling target area (50). In the pre-cooling mode, the first and second cooling members (111, 113) can contact the cooling target area (50) from above and below, respectively. In addition, in the pre-cooling mode, the first and second cooling members (111, 113) can press the cooling target area (50) from above and below.

[0069] Additionally, in the pre-cooling mode, the temperature of the cooling target area (50) can be lowered by approximately 5°C to 10°C compared to the process temperature by the first and second cooling members (111, 113).

[0070] In addition, before performing the sealing mode of the sealing portion (130), by pre-cooling the inner peripheral area (50) of the pouch (30) between the sealing target area (60) to be sealed and the inner space (31) of the pouch (30) to the cooling target area (50), the heat (Q) of the sealing portion (130) can be delayed from being transferred to the inner peripheral area (50) of the pouch (30).

[0071] Additionally, after the pre-cooling mode is completed, the sealing mode may be performed. In the sealing mode, the first and second cooling members (111, 113) may be separated from the cooling target area (50) and spaced apart above and below the cooling target area (50).

[0072] In addition, the pouch sealing device (100) includes a sealing portion (130) provided to seal a sealing target area (60) of the pouch (30). Here, the sealing target area (60) is an area where one edge portion (32) of the pouch (30) is to be sealed by the sealing portion (130).

[0073] As described above, one of the border portions (32) may correspond to a long-side border portion (33) or a short-side border portion (34).

[0074] Referring to FIGS. 2 and 6, the sealing portion (130) may be arranged symmetrically vertically with respect to the sealing target area (60). The sealing portion (130) may include first and second sealing members (131, 133).

[0075] As illustrated in FIG. 6, the first and second sealing members (131, 133) may have a bar shape extending along the edge portion (32) of the pouch (30), and the first and second sealing members (131, 133) may have a bar shape having a length longer than the length of the edge portion (32) of the pouch (30). The first and second sealing members (131, 133) may have a predetermined width (w2).

[0076] In addition, the first and second sealing members (131, 133) are provided to be able to be moved up and down along the stacking direction (Z) of the electrode assembly (20). The sealing member (130) may include a second driving unit (160) for moving the first and second sealing members (131, 133) up and down. The second driving unit (160) may be configured to include a cylinder or a motor.

[0077] In the pre-cooling mode of the above cooling unit (110), the first and second sealing members (131, 133) can be spaced apart from each other above and below the sealing target area (60).

[0078] In addition, after the pre-cooling mode is completed, in the sealing mode, the first and second sealing members (131, 133) are moved to contact the sealing target area (60). Thereafter, the first and second sealing members (131, 133) can heat the sealing target area (60) upward and downward. That is, in the sealing mode, the first and second sealing members (131, 133) can pressurize and heat the sealing target area (60) upward and downward.

[0079] Accordingly, the sealing target area (60) can be thermally fused by the heat (Q) of the sealing portion (130). The long edge portion (33) is sealed by the first and second sealing members (131, 133), and a long edge sealing line (71) can be provided in the pouch (30).

[0080] In the above sealing mode, the first and second sealing members (131, 133) can seal one edge portion (32) by heating and pressurizing the sealing target area (60).

[0081] At this time, the pre-cooled cooling target area (50) is in a state of having a lower temperature than other parts of the edge portion (32), so that even if the heat (Q) generated when the sealing portion (130) seals the sealing target area (60) is transferred, the temperature rise is delayed, so that in the sealing mode by the sealing portion (130), the part adjacent to the internal space (31) of the pouch (30) can be prevented from sticking due to heat conduction.

[0082] In addition, the pouch sealing device (100) according to one embodiment of the present invention includes a control unit (150) configured to perform a sealing mode in which the sealing unit (130) heats the sealing target area (60) after a pre-cooling mode in which the cooling unit (110) cools the cooling target area (50). The control unit (150) is configured to control the cooling unit (110) and the sealing unit (130), and may be configured to control the first and second driving units (160, 170).

[0083] Additionally, the control unit (150) causes the cooling unit (110) to cool the cooling target area (50) until the temperature of the cooling target area (50) reaches a preset cooling temperature.

[0084] The above control unit (150) can cause the cooling unit (110) to cool the cooling target area (50) until the temperature of the cooling target area (50) drops to a temperature 5°C to 10°C lower than the process temperature. Before cooling, the temperature of the cooling target area (50) can be approximately 23°C, which is the process temperature (atmospheric temperature). However, the cooling temperature of the pouch (30) can vary depending on the specifications of the pouch (30) for each product.

[0085] The above control unit (150) is provided so that the sealing portion (130) seals the sealing target area (60) at a preset sealing temperature. The sealing temperature of the sealing portion (130) may be in the range of 105°C to 125°C. However, the sealing temperature of the pouch (30) may vary depending on the specifications of the pouch (30) for each product.

[0086] In addition, the control unit (150) can repeatedly perform the sealing mode after the pre-cooling mode for each edge portion (32) of the pouch (30).

[0087] This document shows an example of sealing the long edge portion (33), but the same process as above can also be performed on the short edge portion (34) to seal the short edge portion (34).

[0088] Figures 9 to 11 are schematic diagrams for explaining the process of a pouch sealing device sealing a piercing portion provided in a gas pocket of a pouch in a gas removal process.

[0089] The gas removal process is a process for removing gas generated during the activation process of the battery cell. To remove gas within the battery cell (10), a portion of the gas pocket (39) of the pouch (30) is pierced, and the gas is vented to the outside of the battery cell through the piercing portion (40). In the gas removal process, after the gas within the battery cell (10) is removed, a sealing process is performed to separate the internal space containing the electrode assembly (20) from the piercing portion (40).

[0090] The above pouch sealing device (100) can seal the gas pocket (39) in the same manner as the process of sealing the edge portion (32) of the pouch (30) described above.

[0091] Referring to FIG. 9, the first cooling member (111) contacts the cooling target area (50) of the pouch (30) between the sealing target area (60) and the electrode assembly (20) and cools the cooling target area (50). When the cooling target area (50) is pre-cooled to a preset cooling temperature, the first cooling member (111) is separated from the cooling target area (50).

[0092] Referring to FIGS. 10 and 11, the first sealing member (131) pressurizes and heats the sealing target area (60) to seal the gas pocket. Accordingly, a pocket sealing line (73) is provided in the gas pocket (39) after the gas removal process. The pocket sealing line (73) is provided to separate the electrode assembly (20) and the piercing portion (40).

[0093] The preferred embodiments of the present invention described above are disclosed for the purpose of illustration, and those skilled in the art having ordinary knowledge of the present invention will be able to make various modifications, changes, and additions within the spirit and scope of the present invention, and such modifications, changes, and additions should be considered to fall within the scope of the following claims.

[0094] According to a pouch sealing device and a pouch sealing method related to one embodiment of the present invention, when sealing a pouch, only a sealing target area is thermally fused, and adhesion of an inner peripheral area of ​​the pouch can be prevented.

Claims

1. A sealing portion provided to seal a sealing target area of ​​one of a plurality of edge portions of a pouch storing an electrode assembly; A cooling unit provided to cool a cooling target area of ​​the pouch located between the inner space of the pouch in which the electrode assembly is stored and the sealing target area; and A pouch sealing device including a control unit configured to perform a sealing mode for heating the sealing target area through the sealing unit after completing a pre-cooling mode for cooling the cooling target area through the cooling unit.

2. In paragraph 1, A pouch sealing device in which the cooling target area of ​​the pouch extends from the sealing target area toward the inner space of the pouch.

3. In paragraph 1, A pouch sealing device including a first cooling member arranged parallel to the length direction of one edge of the pouch and provided so as to be in contact with the cooling target area.

4. In paragraph 3, The above first cooling member is a pouch sealing device including a Peltier element.

5. In paragraph 3, A pouch sealing device in which the first cooling member is a bar-shaped device having a length longer than the length of the edge portion.

6. In paragraph 3, The cooling unit further includes a second cooling member arranged symmetrically with respect to the first cooling member with respect to the cooling target area, A pouch sealing device in which the first and second cooling members are arranged to be movable toward or away from each other.

7. In paragraph 1, A pouch sealing device, wherein the sealing member is arranged symmetrically with respect to the sealing target area and includes first and second sealing members arranged to heat the sealing target area upward and downward in the sealing mode.

8. In paragraph 7, A pouch sealing device in which the first and second sealing members are arranged to seal one edge of the pouch in the form of a line having a predetermined width.

9. In paragraph 7, A pouch sealing device in which the first and second sealing members are arranged to be spaced apart from the pouch in the pre-cooling mode of the cooling unit.

10. In paragraph 7, A pouch sealing device in which the first and second sealing members have a bar shape having a length longer than the length of the edge of the pouch and are arranged to be able to move toward or away from each other.

11. In paragraph 1, The above control unit is a pouch sealing device configured to repeatedly perform the sealing mode after the pre-cooling mode for each edge of the pouch.

12. A pouch sealing method using a pouch sealing device according to Article 1, A pre-cooling step of cooling a cooling target area extending inwardly toward one edge of the above pouch; and A pouch sealing method comprising a sealing step of sealing a sealing target area of ​​the edge portion after pre-cooling is completed.

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