Formation Method of Pouch-Type Battery Cell

Abstract

The disclosed invention relates to a method for forming a battery cell by a formation device for a pouch-type battery cell, which includes a first charging stage of charging the battery cell at a charging unit, a hole processing stage of forming a discharge hole in a gas pocket portion of the charged battery cell, a gas discharge stage of discharging internal gas generated during charging through the discharge hole, and a sealing stage of sealing the discharge hole.

Description

Technical Field

[0001] The present invention relates to a method for forming a pouch-type battery cell.

[0002] More specifically, the present invention relates to a method for forming a pouch-type battery cell that can prevent electrolyte from being discharged together when discharging gas generated during the formation process of the battery cell, thereby preventing external contamination.

[0003] This application claims the benefit of priority based on Korean Patent Application No. 10-2022-0113041 filed on September 6, 2022, and all the contents disclosed in the literature of the Korean patent application are incorporated herein by reference.

Background Art

[0004] Generally, secondary batteries can be classified into cylindrical, prismatic, or pouch-type according to their shape. Among them, the pouch-type secondary battery uses a pouch exterior material composed of a multilayer film of a metal layer (foil) and synthetic resin layers coated on the upper and lower surfaces of the metal layer to form its appearance. Therefore, it can significantly reduce the weight of the battery compared to cylindrical or prismatic batteries using metal cans, making it possible to reduce the weight of the battery and allowing for various forms of change, which has attracted much attention. In such a pouch-type secondary battery, the electrode assembly is housed in a stacked form, and an electrode tab and an electrode lead are connected to the electrode assembly, and the electrode lead protrudes from the pouch exterior material. Such an electrode lead comes into contact with an external device and is electrically connected to receive power from the external device.

[0005] The pouch-type secondary battery is manufactured through a process of assembling cells and activating the battery. In the battery activation stage, the secondary battery cell is mounted on a charge and discharge device, and charging and discharging are performed under the conditions required for activation. Thus, the process of performing predetermined charge and discharge using a charge and discharge device for battery activation is called a formation process.

[0006] During such a formation process, both sides of the battery cell can be pressurized using a pressurizing means such as a jig (Zig) including a flat pressurizing plate during activation charging, which is also referred to as jig formation.

[0007] The jig formation as described above can prevent the expansion of the negative electrode during the activation process, promote the chemical reaction of the battery, induce gas generation, and the generated internal gas is moved to the gas pocket part.

[0008] Here, when the formation process is performed in a sealed state after accommodating the electrode assembly in the pouch and injecting the electrolyte, gas is generated by the chemical reaction between the electrolyte and the electrode, and as a result, the gas pocket part of the pouch-type secondary battery expands.

[0009] When the gas pocket part expands excessively in this way, interference and collision with the transfer means may occur when the battery cell is carried out from the jig formation equipment, and defects in the appearance of the battery cell may occur due to interference between the battery cells during the transfer process, and there is a problem that an excessive amount of the pouch is required to form a sufficient internal space for the gas pocket part.

[0010] In order to solve the above-described problems, a discharge hole is formed in the gas pocket part of the battery cell during the formation process of the battery cell, and the gas generated during charging is discharged to the outside.

[0011] However, there is a problem that when a discharge hole is formed in the gas pocket part of the battery cell, the electrolyte is discharged together with the gas due to an increase in the internal pressure of the battery cell during gas discharge, contaminating the outside, and a safety accident may occur.

Prior Art Document

Patent Document

[0012]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0013] The present invention was made to solve the above problems. In the formation process, the pouch-type battery cell is partially charged to generate gas, and after being partially expanded so that the vacuum-sealed portions of the gas pocket portions are separated from each other, a discharge hole is formed in the partially expanded gas pocket portion to discharge only the internal gas to the outside without discharging the electrolyte. Another object of the present invention is to provide a formation method for a pouch-type battery cell capable of stable charge and discharge by performing residual charging again on the battery cell from which the gas has been discharged and naturally discharging the internal gas generated during the process.

[0014] Another object of the present invention is to provide a formation method for a pouch-type battery cell that can prevent peripheral contamination by preventing the discharge of the electrolyte together with the gas discharge by discharging only the internal gas generated in the battery cell during the formation process.

Means for Solving the Problems

[0015] In order to achieve the above problems, the present invention provides a method for forming a battery cell (pouch-type battery cell), including: a first charging step of charging the battery cell at a charging unit; a hole processing step of forming a discharge hole in a gas pocket portion of the charged battery cell; a gas discharge step of discharging the internal gas generated during charging through the discharge hole; and a sealing step of sealing the discharge hole.

[0016] As an embodiment, the method may further include a second charging step of charging the battery cell after the gas discharge step of discharging the internal gas through the discharge hole formed in the gas pocket portion.

[0017] As another embodiment, the first charging step may perform partial charging on the battery cell to generate gas inside the battery cell and partially expand the gas pocket portion.

[0018] As a specific embodiment, partial charging can charge the battery cell before full charge.

[0019] As another specific embodiment, partial charging can charge at 50% or less of the total charge capacity of the battery cell.

[0020] As one embodiment, partial charging can charge until the portion in vacuum contact with the gas pocket of the battery cell separates.

[0021] As another embodiment, after performing the first charging stage on the battery cell, a discharge hole can be formed in the partially expanded gas pocket portion to discharge the internal gas.

[0022] As one embodiment, the second charging stage can perform the remaining charge after discharging the gas through the discharge hole of the gas pocket portion.

[0023] As a specific embodiment, the remaining charge can be charged while discharging the gas through the discharge hole of the gas pocket portion.

[0024] As another specific embodiment, the remaining charge can be charged before the battery cell is fully charged.

[0025] As another specific embodiment, the remaining charge can be charged up to 70% of the total charge capacity of the battery cell.

Advantages of the Invention

[0026] According to the present invention, by performing partial charging on the pouch-type battery cell and partially expanding the gas pocket portion so that the portions in vacuum contact with each other separate, preventing the electrolyte from being discharged when forming the discharge hole in the gas pocket portion, and stably discharging only the internal gas.

[0027] Further, by performing partial charging and residual charging of the battery cell before and after forming a discharge hole in the gas pocket portion of the battery cell during the formation process, only the internal gas can be discharged through the discharge hole, and only the internal gas can be stably discharged without discharging the electrolyte, thereby preventing contamination of the surroundings.

Brief Description of the Drawings

[0028]

Figure 1

Figure 2

Figure 3

Figure 4

Modes for Carrying Out the Invention

[0029] Hereinafter, the present invention will be described in detail. Before that, the terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, but should be construed as meanings and concepts consistent with the technical idea of the present invention based on the principle that the inventor can appropriately define the concept of the terms in order to best explain his own invention.

[0030] As used throughout the specification of the present invention, terms such as "comprising" and "having" are intended to specify the presence of the features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, and are to be understood not to preclude in advance the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof.

[0031] Also, when a part such as a layer, film, region, or plate is said to be "on" another part, this includes not only the case where it is directly on the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is said to be "under" another part, this includes not only the case where it is directly under the other part, but also the case where there is another part in between. Also, in the specification of the present invention, being "disposed on" can include not only the upper part but also the case of being disposed on the lower part.

[0032] Also, when a part such as a layer, film, region, or plate is said to be "on" another part, this includes not only the case where it is directly on the other part, but also the case where there is another part in between. Conversely, when a part such as a layer, film, region, or plate is said to be "under" another part, this includes not only the case where it is directly under the other part, but also the case where there is another part in between. Also, in this application, being "disposed on" can include not only the upper part but also the case of being disposed on the lower part.

[0033] (First Embodiment) FIG. 1 is a flowchart showing a formation method of a pouch-type battery cell according to an embodiment of the present invention. FIG. 2 is a drawing schematically showing an embodiment of a formation apparatus for a pouch-type battery cell for explaining the formation method of the pouch-type battery cell according to the present invention. FIG. 3 is a drawing schematically showing another embodiment of a formation apparatus for a pouch-type battery cell for explaining the formation method of the pouch-type battery cell according to the present invention. FIG. 4 is a drawing schematically showing another embodiment of a formation apparatus for a pouch-type battery cell for explaining the formation method of the pouch-type battery cell according to the present invention.

[0034] As shown in FIG. 1, a formation method of a battery cell according to an embodiment of the present invention includes a first charging step (S10) of charging the battery cell in a charging unit, a hole processing step (S30) of forming a discharge hole in a gas pocket portion of the charged battery cell, a gas discharging step (S50) of discharging internal gas generated during charging through the discharge hole, and a sealing step (S70) of sealing the discharge hole.

[0035] Specifically, the present invention is a formation method for performing predetermined charge and discharge on a battery cell for activation of the battery cell, and the first charging step is performed (S10) under conditions necessary for activation of a plurality of battery cells arranged in a charging unit.

[0036] Here, charging can be performed sequentially on the battery cells arranged in the charging unit, or charging can be performed simultaneously on all the battery cells arranged in the charging unit.

[0037] In the first charging step, partial charging is performed on the battery cell to generate gas inside the battery cell and partially expand the gas pocket portion.

[0038] That is, in the first charging step, partial charging is performed on the battery cell to generate gas by a chemical reaction between the electrolyte and the electrode inside the battery cell, thereby partially expanding the gas pocket portion of the battery cell.

[0039] Here, the partial charging can be performed until before full charge of the battery cell.

[0040] In this way, by charging the battery cell until before full charge, it is possible to prevent the gas pocket portion from expanding excessively due to gas generated at the time of full charge of the battery cell in the formation process of the existing battery cell.

[0041] At this time, the partial charging can be performed at 50% or less of the total charging capacity of the battery cell.

[0042] Thus, by charging the battery cell to 50% or less of the overall charge capacity, the gas generated inside the battery cell can be adjusted to a predetermined generation amount, and the gas pocket portion can be partially expanded so that the gas pocket portion does not expand excessively, thereby controlling the pressure inside the battery cell.

[0043] Preferably, the partial charge can be performed by charging the battery cell to 5% to 50% or less of the overall charge capacity.

[0044] A hole processing step of forming a discharge hole in the gas pocket portion of the battery cell charged through the first charging step is performed (S30).

[0045] Then, the gas inside the battery cell is discharged through the discharge hole formed in the gas pocket portion of the battery cell through the hole processing step (S50).

[0046] Here, after performing the first charging step on the battery cell, a discharge hole is formed in the partially expanded gas pocket portion, and the internal gas is discharged through the discharge hole of the partially expanded gas pocket portion.

[0047] As described above, after the battery cell is partially charged and the gas pocket portion is partially expanded so as not to expand excessively, by forming a discharge hole in the gas pocket portion, it is possible to prevent the discharge of the electrolyte to the outside of the battery cell due to capillary action caused by the increase in the internal pressure of the existing battery cell when discharging the gas through the discharge hole, and it is possible to discharge only the internal gas without discharging the electrolyte.

[0048] Here, after the gas discharge step of discharging the internal gas through the discharge hole formed in the gas pocket portion, a second charging step (S60) of charging the battery cell may be further included.

[0049] At this time, the second charging step can perform the remaining charge after discharging the gas through the discharge hole of the gas pocket portion.

[0050] The above residual charging can be performed while discharging gas through the discharge holes in the gas pocket portion.

[0051] As described above, after partially charging the battery cell to partially expand the gas pocket portion, a discharge hole is formed in the partially expanded gas pocket portion to primarily discharge the gas generated inside the battery cell. Then, the battery cell from which the internal gas generated by the partial charging has been discharged is subjected to residual charging, and the residual charging is stably performed while secondarily discharging the gas generated during the residual charging. By doing so, it is possible to fundamentally prevent the external discharge of the electrolytic solution vacuum-injected into the battery cell.

[0052] Here, the above residual charging can be performed until the battery cell is fully charged, and preferably, it can be charged up to 70% of the total charging capacity of the battery cell.

[0053] Hereinafter, the formation method of the pouch-type battery cell according to an embodiment of the present invention will be described in more detail together with the formation apparatus for the pouch-type battery cell.

[0054] First, as shown in FIG. 2, a charging unit 10 that charges the battery cell 3, a loading buffer unit 20 where the battery cell 3 waits before being input into the charging unit 10 and on which the battery cell is placed by a loader / unloader 90, an unloading buffer unit 30 where the battery cell 3 unloaded after the charging is completed from the charging unit 10 waits, a hole processing unit 50 provided on one side of the loading buffer unit 20 and forming a discharge hole 3b in the gas pocket portion 3a of the battery cell 3 accommodated in the loading buffer unit 20, and a sealing unit 70 provided on one side of the unloading buffer unit 30 and sealing the discharge hole 3b formed in the gas pocket portion 3a of the battery cell 3 accommodated in the unloading buffer unit 30. A formation method by the formation apparatus 1 for the pouch-type battery cell including these components will be described.

[0055] After accommodating a laminate composed of a positive electrode, a separator, and a negative electrode in a pouch and sealing it, an electrolytic solution is injected into the pouch under vacuum to manufacture the pouch-type battery cell 3.

[0056] The manufactured battery cell 3 is supplied to the loading buffer unit 20, and the battery cell 3 supplied to the loading buffer unit 20 is transferred to the charging unit 10 for charging and discharging.

[0057] The battery cell 3 supplied to the charging unit 10 performs predetermined charging and discharging with a charging and discharging device (not shown) provided in the charging unit 10 for battery activation.

[0058] Specifically, the battery cell 3 supplied to the charging unit 10 is partially charged to generate gas inside the battery cell 3 and partially expand the gas pocket portion 3a.

[0059] After partially charging the battery cell 3 via the charging unit 10 to partially expand the gas pocket portion 3a in this way, the battery cell 3 with the partially expanded gas pocket portion 3a is transferred to the loading buffer unit 20.

[0060] The battery cells 3 transferred and arranged in the loading buffer unit 20 form a discharge hole 3b in the partially expanded gas pocket portion 3a through a hole processing unit 50 provided on one side of the loading buffer unit 20. That is, the hole processing unit 50 moves toward the battery cells 3 transferred and arranged in the loading buffer unit 20, and forms a discharge hole 3b having a predetermined size while pressing the gas pocket portion 3a via the hole processing unit 51 of the hole processing unit 50 transferred to the battery cell 3.

[0061] As described above, a discharge hole 3b is formed in the gas pocket portion 3a of the partially expanded battery cell 3 to discharge the gas inside the battery cell 3, and the discharged gas is discharged to the outside through a gas discharge portion (not shown) provided on the formation device 1.

[0062] The gas discharged from the battery cell 3 through the discharge hole 3b formed in the gas pocket portion 3a via the hole processing portion 50 in the loading buffer portion 20 is transferred back to the charging portion 10, and the battery cell 3 transferred to the charging portion 10 performs residual charging.

[0063] At this time, the gas generated inside the battery cell 3 during residual charging is discharged through the discharge hole 3b previously formed in the gas pocket portion 3a while performing residual charging.

[0064] The battery cell 3 that has completed residual charging through the charging portion 10 is transferred to the unloading buffer portion 30, and the battery cell 3 transferred to the unloading buffer portion 30 seals the discharge hole 3b through the sealing unit 71 of the sealing portion 70 provided on one side of the unloading buffer portion 30, and the sealed battery cell 3 is carried out.

[0065] On the other hand, as shown in FIG. 3, a separate hole processing buffer portion 80 is further included on the charging portion 10, and a formation method by a formation device 1' of a pouch-type battery cell in which a hole processing portion 50' is provided on one side of the hole processing buffer portion 80 will be described.

[0066] At this time, after transferring the partially charged battery cell 3 through the charging portion 10 to the hole processing buffer portion 80, the discharge hole 3b is formed in the battery cell 3 transferred to the hole processing buffer portion 80.

[0067] Specifically, the manufactured pouch-type battery cell 3 is supplied to the loading buffer portion 20, and the battery cell 3 supplied to the loading buffer portion 20 is transferred to the charging portion 10 for charging and discharging.

[0068] The battery cell 3 supplied to the charging portion 10 is partially charged, gas is generated inside the battery cell 3, and the gas pocket portion 3a is partially expanded.

[0069] In this way, after partially charging the battery cell 3 via the charging unit 10 to partially expand the gas pocket portion 3a, the battery cell 3 with the partially expanded gas pocket portion 3a is transferred to the hole processing buffer portion 80 disposed on the charging unit 10.

[0070] The battery cells 3 transferred and arranged in the hole processing buffer portion 80 form discharge holes 3b in the partially expanded gas pocket portion 3a through the hole processing portion 50' provided on one side of the hole processing buffer portion 80.

[0071] Also at this time, the hole processing portion 50' moves toward the battery cells 3 transferred and arranged in the hole processing buffer portion 80, and while pressing the gas pocket portion 3a through the hole processing unit 51' of the hole processing portion 50' transferred to the battery cell 3, a discharge hole 3b having a predetermined size is formed.

[0072] In this way, discharge holes 3b are formed in the gas pocket portion 3a of the partially expanded battery cell 3 to discharge the gas inside the battery cell 3, and the discharged gas is discharged to the outside through a gas discharge portion (not shown) provided on the formation device 1'.

[0073] The battery cell 3 from which the gas has been discharged through the discharge hole 3b formed through the hole processing portion 50' in the hole processing buffer portion 80 is transferred to the charging unit 10 again, and the battery cell 3 transferred to the charging unit 10 performs residual charging.

[0074] The battery cell 3 for which the residual charging has been completed via the charging unit 10 is transferred to the unloading buffer portion 30, and the battery cell 3 transferred to the unloading buffer portion 30 seals the discharge hole 3b through the sealing portion 70 provided on one side of the unloading buffer portion 30, and the sealed battery cell 3 is carried out.

[0075] When performing a formation process through a formation device for a pouch-type battery cell configured as described above, a hole processing buffer part 80 is provided on the charging part 10, and a hole processing part 50' for forming a discharge hole 3b is provided on one side of the hole processing buffer part 80. As a result, compared with a formation device in which the hole processing part 50' is provided on one side of the loading buffer part 20, the transfer distance of the battery cell 3 can be shortened, and the overall process time can be reduced.

[0076] Here, the hole processing part 50' provided on one side of the hole processing buffer part 80 may be formed in a plurality corresponding to the battery cells 3 arranged in the charging part 10, with a hole processing unit 51' for forming a discharge hole 3b in the gas pocket part 3a of the battery cell 3. In this case, after all the hole processing units 51' of the hole processing part 50' move toward the battery cell 3, the discharge hole 3b may be formed simultaneously for all the battery cells 3 arranged in the charging part 10.

[0077] In this way, the hole processing part 50' provided on one side of the hole processing buffer part 80 moves forward toward the battery cell 3 accommodated in the hole processing buffer part 80, forms a discharge hole 3b in the gas pocket part 3a of all the battery cells 3 arranged in the hole processing buffer part 80, and then moves backward again to return to the original position.

[0078] On the other hand, when the hole processing unit 51' is formed as one in the hole processing part 50', while the hole processing unit 51' moves forward and backward toward the battery cell 3 and slides in the thickness direction of the battery cell 3, the discharge hole 3b can be sequentially formed for the battery cells 3 arranged in the hole processing buffer part 80.

[0079] On the other hand, as shown in FIG. 4, a formation method by a formation device 1'' for a pouch-type battery cell in which a hole processing part 50'' for forming a discharge hole 3b in the gas pocket part 3a of the battery cell 3 is provided on one side of the charging part 10 will be described.

[0080] At this time, since both the process of charging the battery cell 3 and the process of forming the discharge hole 3b in the gas pocket portion 3a of the battery cell 3 can be performed in the charging unit 10, the convenience of the process can be improved and the process time can be shortened.

[0081] Specifically, the manufactured battery cell 3 is supplied to the loading buffer unit 20, and the battery cell 3 supplied to the loading buffer unit 20 is transferred to the charging unit 10 for charging and discharging.

[0082] The battery cell 3 transferred to the charging unit 10 is partially charged to generate gas inside the battery cell 3 and partially expand the gas pocket portion 3a.

[0083] In this way, after partially charging the battery cell 3 via the charging unit 10 to partially expand the gas pocket portion 3a, the hole processing unit 50'' provided on one side of the charging unit 10 moves toward the battery cell 3 in which the gas pocket portion 3a is partially expanded, and a discharge hole 3b is formed in the partially expanded gas pocket portion 3a via the hole processing unit 50''.

[0084] That is, the hole processing unit 50'' moves toward the battery cell 3 that has completed partial charging on the charging unit 10, and after pressing the gas pocket portion 3a via the hole processing unit 51'' of the hole processing unit 50'' that has moved toward the battery cell 3, a discharge hole 3b is formed.

[0085] At this time, when forming the discharge hole 3b in the gas pocket portion 3a of the battery cell 3 via the hole processing unit 50'', the charging unit 10 can temporarily stop charging the battery cell 3.

[0086] In this way, the charging unit 10 performs residual charging again on the battery cell 3 from which gas has been discharged through the discharge hole 3b formed in the gas pocket portion 3a, and the internal gas generated during the residual charging is discharged while performing the residual charging through the discharge hole 3b formed in the gas pocket portion 3a.

[0087] Via the charging unit 10, the battery cell 3 is transferred to the unloading buffer unit 30, and the battery cell 3 transferred to the unloading buffer unit 30 seals the discharge hole 3b through the sealing unit 70 provided on one side of the unloading buffer unit 30 and is then carried out after being sealed.

[0088] When performing the formation process by the formation device 1 of the pouch-type battery cell configured as described above, since the hole processing unit 50'' for forming the discharge hole 3b is provided on the charging unit 10, the transfer process of the battery cell 3 can be reduced and the process time can be significantly shortened.

[0089] In this way, by performing partial charging to partially expand the gas pocket portion 3a, forming the discharge hole 3b in the partially expanded gas pocket portion 3a and discharging only the gas, and then performing the remaining charging again, it is possible to prevent both the gas and the electrolyte inside the battery cell 3 from being discharged through the discharge hole 3b due to excessive expansion of the gas pocket portion 3a during charging of the existing battery cell 3, and it is possible to prevent contamination of the formation device by the electrolyte.

[0090] That is, conventionally, when injecting the electrolyte into the pouch-type battery cell 3 at the assembly stage in a vacuum state, and then due to the vacuum-adhered portion and the internal pressure of the gas pocket portion 3a, the electrolyte was discharged together when discharging the internal gas of the pouch battery cell 3 during the formation of the discharge hole 3b. However, by partially charging the battery cell 3 by the formation method according to the present invention to partially expand the gas pocket portion 3a, the internal pressure of the battery cell 3 can be formed to a certain magnitude and only the gas excluding the electrolyte can be stably discharged.

[0091] (Second Embodiment) In another embodiment of the present invention, the partial charging through the charging unit can be performed until the time when the portion in vacuum contact with the gas pocket portion of the battery cell separates.

[0092] That is, when forming a discharge hole in an existing battery cell, partial charging is performed until the portions of the gas pocket portion of the battery cell that are in vacuum contact are spaced apart from each other at a certain interval, so as to prevent both gas and electrolyte from being discharged along the portion in vacuum contact with the gas pocket portion of the battery cell. After that, a discharge hole can be formed in the gas pocket portion of the partially charged battery cell.

[0093] As described above, by allowing the portions of the gas pocket portion that are in vacuum contact to separate and expand, it is possible to prevent both the internal gas and the electrolyte from being discharged due to the internal pressure when forming a discharge hole in the gas pocket portion.

[0094] In this embodiment, partial charging is performed until the portions of the gas pocket portion of the battery cell that are in vacuum contact are separated. However, it is also possible to perform charging until the gas pocket portion expands to a predetermined size that is set.

[0095] That is, charging can be performed only until the gas pocket portion expands to a predetermined size compared to the reference expansion size of the gas pocket portion at full charge of the battery cell.

[0096] Thus, conventionally, during electrolyte injection into a pouch-type battery cell at the assembly stage, after injection in a vacuum state, due to the portions of the gas pocket portion that are in vacuum contact and the internal pressure, both the internal gas and the electrolyte of the pouch battery cell can be discharged when forming a discharge hole. However, in this embodiment, by partially charging the battery cell to separate the portions of the gas pocket portion that are in vacuum contact from each other, or by expanding the gas pocket portion to a predetermined size, only the gas excluding the electrolyte can be stably discharged.

[0097] Here, the set size of the gas pocket portion can be set to expand to about 1 / 3 to 2 / 3 of the size expanded by the gas generated inside the battery cell at full charge of the existing battery cell, but it is not limited to this.

[0098] At this time, a separate sensing sensor for sensing the size of the gas pocket portion, or a vision device capable of taking an image and comparing and analyzing the size of the gas pocket portion may be further included.

[0099] On the other hand, after setting the charging time during partial charging of the battery cell, partial charging is performed for a set time to partially expand the gas pocket portion, separate the vacuum - adhered portion of the gas pocket portion, or expand the gas pocket portion to a predetermined size to form a discharge hole in the gas pocket portion, and it is also possible to stably discharge only gas without discharging the electrolyte, but it is not limited thereto, and various other modifications can be implemented.

[0100] As described above, the present invention is illustrated and described in connection with specific embodiments, but it is easily understood by anyone with ordinary knowledge in the art that various modifications and changes are possible within the scope not departing from the spirit and scope of the invention shown in the claims.

Explanation of Reference Numerals

[0101] 1, 1', 1'': Formation device for pouch - type battery cell 3: Battery cell 3a: Gas pocket portion 3b: Discharge hole 10: Charging unit 20: Loading buffer unit 30: Unloading buffer unit 50, 50', 50'': Hole processing unit 51, 51', 51'': Hole processing unit 70: Sealing unit 80: Hole processing buffer unit 90: Loader / Unloader

Claims

1. In a method for forming a pouch-type battery cell, a first charging step of charging the pouch-type battery cell at a charging unit; a hole processing step of forming a discharge hole in a gas pocket portion of the charged pouch-type battery cell; a gas discharge step of discharging internal gas generated during charging through the discharge hole; a sealing step of sealing the discharge hole; A method for forming a pouch-type battery cell, comprising:

2. A method for forming a pouch-type battery cell according to claim 1, further comprising a second charging step of charging the pouch-type battery cell after the gas discharge step of discharging the internal gas through the discharge hole formed in the gas pocket portion.

3. The first charging step is A method for forming a pouch-type battery cell according to claim 2, wherein partial charging is performed on the pouch-type battery cell to generate gas inside the pouch-type battery cell and partially expand the gas pocket portion.

4. The partial charging is A method for forming a pouch-type battery cell according to claim 3, wherein charging is performed until before full charge of the pouch-type battery cell.

5. The partial charging is A method for forming a pouch-type battery cell according to claim 4, wherein charging is performed at 50% or less of the total charging capacity of the pouch-type battery cell.

6. The partial charging is A method for forming a pouch-type battery cell according to claim 3, wherein charging is performed until the portion in vacuum contact with the gas pocket portion of the pouch-type battery cell separates.

7. A method for forming a pouch-type battery cell according to claim 2, wherein after the first charging step is performed on the pouch-type battery cell, a discharge hole is formed in the partially expanded gas pocket portion to discharge the internal gas.

8. The second charging step is A method for forming a pouch-type battery cell according to claim 7, wherein after discharging gas through the discharge hole in the gas pocket portion, residual charging is performed.

9. The residual charging is A method for forming a pouch-type battery cell according to claim 8, wherein charging is performed while discharging the gas through the discharge hole in the gas pocket portion.

10. The residual charging is A method for forming a pouch-type battery cell according to claim 8, wherein charging is performed until before full charge of the pouch-type battery cell.

11. The residual charging is The method for forming a pouch-type battery cell according to claim 10, wherein the pouch-type battery cell is charged up to 70% of its total charge capacity.

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