Battery cell manufacturing method

Abstract

A battery cell manufacturing method according to one embodiment of the present disclosure comprises: a battery cell assembling step of mounting an electrode assembly, which includes a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode, into a housing part of a battery case; a needle insertion step of inserting a needle into the inside of the electrode assembly; and an electrolyte injection and sealing step of injecting an electrolyte solution into the interior of the battery case in a state in which the needle portion is inserted into the electrode assembly, and then sealing the battery case.

Description

Technical Field

[0001] Cross - Reference to Related Applications

[0002] This application claims the benefit of Korean Patent Application No. 10-2023-0146682, filed with the Korean Intellectual Property Office on October 30, 2023, the entire disclosure of which is incorporated herein by reference.

[0003] The present disclosure relates to a method for manufacturing a battery cell, and more particularly, to a method for manufacturing a battery cell that makes it easier to discharge air and / or gas generated inside the battery cell during a process, while improving the wettability of an electrolyte solution to an electrode. Background Art

[0004] With the technological development of mobile devices and the increase in their demand, the demand for secondary batteries as an energy source has also rapidly increased. In particular, secondary batteries have attracted a great deal of attention as an energy source not only for power-driven devices such as electric bicycles, electric vehicles, and hybrid electric vehicles, but also for mobile devices such as mobile phones, digital cameras, laptop computers, and wearable devices.

[0005] Based on the shape of the battery case, secondary batteries can be classified into cylindrical batteries in which an electrode assembly is installed in a cylindrical metal container, prismatic batteries in which an electrode assembly is installed in a prismatic metal container, or pouch-type batteries in which an electrode assembly is installed in a pouch-shaped case made of an aluminum laminate. Here, the electrode assembly installed in the battery case serves as a power generation element capable of charging / discharging, and includes a stacked structure of a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode. The electrode assembly can be classified into a jelly roll type formed by interposing a separator between a long sheet-type positive electrode and a long sheet-type negative electrode and winding them, and a stacked type formed by sequentially stacking a plurality of positive electrodes and negative electrodes with a separator interposed therebetween.

[0006] Among them, in particular, due to advantages such as low manufacturing cost, light weight, and easy shape change, the use of pouch-type batteries configured to have a structure in which such a stacked type or stacked / folded type electrode assembly is installed in a pouch-shaped battery case made of an aluminum laminate is gradually increasing.

[0007] However, when manufacturing a pouch-type battery, an electrolyte solution can be injected into the pouch-type battery case in a state where the electrode assembly is installed in the pouch-type battery case. In particular, during the process of manufacturing a pouch-type battery, air, gas, etc. trapped between the electrodes and the separator of the electrode assembly or between the electrodes may not be discharged. Such air, gas, etc. may interfere with the charging and discharging of the battery, which will cause problems such as the generation of lithium plating and a reduction in battery capacity.

[0008] Therefore, it is necessary to develop a method for manufacturing a battery cell that makes it easier to discharge air and / or gas generated inside the battery cell during the manufacturing process, while improving the wettability of the electrolyte solution to the electrodes. Summary of the Invention

[0009] Technical Problem

[0010] An object of the present disclosure is to provide a method for manufacturing a battery cell that makes it easier to discharge air and / or gas generated inside the battery cell during the manufacturing process, while improving the wettability of the electrolyte solution to the electrodes.

[0011] The technical object of the present disclosure is not limited to the above object, and those skilled in the art should clearly understand other objects not mentioned herein from the following detailed description and drawings.

[0012] Technical Solution

[0013] According to an embodiment of the present disclosure, there is provided a method for manufacturing a battery cell, including: a battery cell assembly step of installing an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode into a receiving portion of a battery case; a needle portion insertion step of inserting a needle portion into the interior of the electrode assembly; and an electrolyte injection and sealing step of injecting an electrolyte solution into the interior of the battery case in a state where the needle portion is inserted into the electrode assembly, and then sealing the battery case.

[0014] In the needle portion insertion step, the needle portion may be inserted between the separator and the positive electrode disposed adjacent to each other, or may be inserted between the separator and the negative electrode disposed adjacent to each other.

[0015] In the needle portion insertion step, the needle portion may be inserted between the separator and the positive electrode disposed adjacent to each other, and may be inserted between the separator and the negative electrode disposed adjacent to each other.

[0016] The needle portion may be inserted into a central portion of the electrode assembly.

[0017] The needle portion may include at least one needle extending in the width direction of the electrode assembly.

[0018] The at least one needle may have a thickness of 0.2 mm or more and 1 mm or less.

[0019] The at least one needle may be arranged in an inclined direction with respect to the thickness direction of the electrode assembly.

[0020] The needle portion may further include a connecting portion extending in the thickness direction of the electrode assembly, and one end of the at least one needle may be fixed to the connecting portion.

[0021] The connecting portion may be located between the electrode assembly and the sealing portion.

[0022] After the electrolyte injection and sealing step, the method may further include: an activation step of activating the battery cell, and a degassing and needle portion removal step of removing the gas generated inside the battery cell and removing the needle portion.

[0023] In the degassing and needle portion removal step, a cut is made between the sealing portion of the battery case and the electrode assembly, so that an opening portion may be formed on one side surface of the battery case.

[0024] In the degassing and needle portion removal step, a needle removal portion may be inserted into the opening portion to remove the needle portion from the electrode assembly.

[0025] After the degassing and needle portion removal step, the method may further include: a pressing and rolling step of pressing and rolling the outer surface of the battery cell, and a resealing step of resealing the portion cut between the sealing portion of the battery case and the electrode assembly.

[0026] The activation step may include: a pre-aging step of storing the battery cell at room temperature, a forming step of performing at least one charge and discharge on the battery cell, and an aging step of storing the battery cell at a high temperature.

[0027] Advantageous Effects

[0028] According to an embodiment, the method for manufacturing a battery cell of the present disclosure can make it easier to discharge the air and / or gas generated inside the battery cell during the process, and at the same time improve the wettability of the electrolyte solution to the electrodes.

[0029] The effects of the present disclosure are not limited to the above effects, and those of ordinary skill in the art will clearly understand additional other effects not mentioned herein from the detailed description and the drawings. Description of the Drawings

[0030] Figure 1 is a flowchart showing a method for manufacturing a battery cell according to an embodiment of the present disclosure.

[0031] Figure 2 is a perspective view of a battery cell after the electrolyte injection and sealing step in Figure 1

[0032] Figure 3 shows alongFigure 2 An enlarged view of a part of a cross-section cut along the a-a' axis.

[0033] Figure 4 It shows a cross-section along Figure 2 a cross-section cut along the b-b' axis.

[0034] Figure 5 It shows a perspective view of a battery cell during Figure 1 the degassing and needle removal steps.

[0035] Figure 6 It shows a perspective view of a needle removal part and a needle part inserted into an opening of a battery cell in Figure 5 a battery cell. Detailed Description of Embodiments

[0036] Hereinafter, various embodiments of the present disclosure will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily implement them. The present disclosure can be modified in various different ways and is not limited to the embodiments set forth herein.

[0037] To clearly describe the present disclosure, parts irrelevant to the description will be omitted, and the same reference numerals denote the same or similar elements throughout the specification.

[0038] In addition, in the drawings, the dimensions and thicknesses of each element are arbitrarily shown for convenience of description, and the present disclosure is not necessarily limited to those dimensions and thicknesses shown in the drawings. In the drawings, the thicknesses of layers, regions, etc. are exaggerated for clarity. In the drawings, the thicknesses of some layers and regions are exaggerated for convenience of description.

[0039] In addition, throughout the application, when a part is referred to as "including" or "comprising" a certain component, it means that the part may further include other components without excluding other components, unless there is an explicit contrary description.

[0040] In addition, throughout the application, when referred to as a "plane", it means when viewing the target part from the upper side, and when referred to as a "cross-section", it means when viewing the target part from one side of a vertically cut cross-section.

[0041] Now, a method for manufacturing a battery cell according to an embodiment of the present disclosure will be described.

[0042] Figure 1 It is a flowchart showing a method for manufacturing a battery cell according to an embodiment of the present disclosure. Figure 2 It shows a perspective view of a battery cell after Figure 1 the electrolyte injection and sealing steps. Figure 3 It shows along Figure 2An enlarged view of a part of a cross-section cut along the a-a' axis. Figure 4 is a view showing a cross-section cut along Figure 2 the b-b' axis.

[0043] A method for manufacturing a battery cell according to an embodiment of the present disclosure includes: a battery cell assembly step S100 of installing an electrode assembly 110 including a positive electrode 111, a negative electrode 113, and a separator 115 interposed between the positive electrode 111 and the negative electrode 113 into a receiving portion 123 of a battery case 120; a needle portion insertion step S200 of inserting a needle portion 200 into the interior of the electrode assembly 110; and an electrolyte injection and sealing step S300 of injecting an electrolyte solution into the interior of the battery case 120 while the needle portion 200 is inserted into the electrode assembly 110, and then forming a sealing portion 120s in the battery case 120.

[0044] Referring to Figure 2 , the battery cell 100 assembled in the battery cell assembly step S100 is a pouch-type battery cell, and the battery cell 100 includes the electrode assembly 110 inside the battery case 120. In addition, the battery cell 100 is configured such that an electrode lead 150 connected to an electrode tab (not shown) of the electrode assembly 110 is exposed to the outside, and upper and lower portions of the electrode lead 150 are attached with a lead film (not shown).

[0045] The electrode assembly 110 includes a positive electrode 111, a negative electrode 113, and a separator 115. More specifically, the electrode assembly 110 may have a structure in which the positive electrode 111 and the negative electrode 113 are sequentially stacked and formed in an insulated state from each other with the separator 115 interposed between the positive electrode 111 and the negative electrode 113. Herein, the electrode assembly 110 may be a stacked-type electrode assembly or a stacked / folded-type electrode assembly. However, the shape of the electrode assembly 110 is not limited thereto, and as long as it is a component shape including the positive electrode 111, the negative electrode 113, and the separator 115, it may be included in the present embodiment. In addition, the positive electrode 111, the negative electrode 113, and the separator 115 may be made of materials typically included in a battery cell.

[0046] The electrode lead 150 may include a positive electrode lead 151 connected to a positive electrode tab (not shown) of the electrode assembly 110; and a negative electrode lead 155 connected to a negative electrode tab (not shown) of the electrode assembly 110. In addition, upper and lower portions of the positive electrode lead 151 may be attached with a first lead film 161, and upper and lower portions of the negative electrode lead 155 may be attached with a second lead 165. However, the position of the electrode lead 150 is not limited to being located at both ends of the electrode assembly 110 as shown in Figure 2 , and the positive electrode lead 151 and the negative electrode lead 155 may be together located at one end of the electrode assembly 110.

[0047] The battery cell 100 assembled in the battery cell assembly step S100 may be configured such that with the electrode assembly 110 installed in the recessed receiving portion 123 formed in the battery case 120, the outer peripheral surface of the battery case 120 may be heat-sealed to form a sealed outer peripheral portion 125.

[0048] As Figure 2 shown, one side of the battery case 120 may have a structure extending outward from the receiving portion 123, and one side of the battery case 120 may extend with a relatively wider width than the other side of the battery case 120. In addition, the battery cell 100 assembled in the battery cell assembly step S100 may have the electrode assembly 110 installed in the receiving portion 123 in a state where at least one side of the battery case 120 is unsealed. Here, at least one side of the battery case 120 may be a side among the sides of the electrode assembly 110 where the electrode lead 150 is not provided.

[0049] Referring to Figure 1 and Figure 3 , in the needle portion insertion step S200, the needle portion 200 may be inserted between components that are adjacently arranged among the positive electrode 111, the negative electrode 113, and the separator 115 included in the electrode assembly 100. More specifically, the needle portion 200 may be inserted between the separator 115 and the positive electrode 111 that are adjacently arranged, or may be inserted between the separator 115 and the negative electrode 113 that are adjacently arranged. In addition, the needle portion 200 may be inserted between the separator 115 and the positive electrode 111 that are adjacently arranged, and may be inserted between the separator 115 and the negative electrode 113 that are adjacently arranged.

[0050] As an example, as Figure 3 shown, the needle portion 200 may be respectively located between the positive electrode 111 and / or the negative electrode 113 and the separator 115 that are adjacently arranged with different separators 115. As another example, although not shown in the figure, the needle portion 200 may be respectively located between the positive electrode 111 and the negative electrode 113 and the separator 115 that are adjacently arranged with the same separator 115.

[0051] Therefore, in the battery cell manufacturing method according to the present embodiment, the needle portion insertion step S200 may insert the needle portion 200 into the interior of the electrode assembly 100 to discharge air or gas trapped between the positive electrode 111 and / or the negative electrode 113 and the separator 115 to the outside of the electrode assembly 100, preventing lithium plating (Li-Plating) and capacity reduction that may occur due to such air or gas.

[0052] In addition, the needle part 200 can form a minute step between the positive electrode 111 and / or the negative electrode 113 and the separator 115, and this step can induce capillary force. That is to say, when the electrolyte solution is injected in a state where the needle part 200 is inserted into the electrode assembly 100, the wettability of the electrolyte solution to the positive electrode 111 and / or the negative electrode 113 can be further improved.

[0053] The needle part 200 can be inserted into the central part of the electrode assembly 110. In other words, the needle part 200 can be located between the separator 115 provided in the central part of the electrode assembly 110 and the positive electrode 111 and / or the negative electrode 113 provided adjacent to the separator 115. Here, the central part of the electrode assembly 110 can refer to the central part based on the thickness direction of the electrode assembly 110.

[0054] Therefore, in the method for manufacturing a battery cell according to the present embodiment, in the needle part insertion step S200, the needle part 200 is inserted into the central part of the electrode assembly 110, which can further improve the wettability of the positive electrode 111 and / or the negative electrode 113 located in the central part of the electrode assembly 110, and thus can make the wettability of the electrolyte solution relatively uniform based on the position of the electrode assembly 110.

[0055] More specifically, as Figure 3 shown, the needle part 200 can include at least one needle 210 extending in the width direction of the electrode assembly 110.

[0056] As Figure 3 shown, the needle 210 can extend in the width direction of the electrode assembly 110 to a part passing through the center of the electrode assembly 110. As another example, different from Figure 3 this, the needle 210 can extend in the width direction of the electrode assembly 110 to the center of the electrode assembly 110, or can extend to the end of the electrode assembly 110. Here, the length of the needle 210 can be adjusted to a level that does not hinder the wetting of the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 by the electrolyte solution.

[0057] Therefore, in the method for manufacturing a battery cell according to the present embodiment, in the needle part insertion step S200, the length of at least one needle 210 is adjusted, so that the wettability of the electrolyte solution to the positive electrode 111 and / or the negative electrode 113 can be further improved without hindering the wetting of the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 by the electrolyte solution.

[0058] As an example, the thickness of the needle 210 may be 0.2 mm or more and 1 mm or less. However, the thickness of the needle 210 is not limited thereto, and the thickness of the needle 210 may be adjusted to a degree that does not prevent the wetting of the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 by the electrolyte solution.

[0059] Therefore, in the method for manufacturing a battery cell according to the present embodiment, the needle portion insertion step S200 adjusts the thickness of at least one needle 210, so that the wettability of the electrolyte solution to the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 can be further improved without preventing the wetting of the positive electrode 111 and / or the negative electrode 113 by the electrolyte solution.

[0060] In addition, as Figure 3 shown, at least one needle 210 may be arranged in an oblique direction with respect to the thickness direction of the electrode assembly 110. However, the arrangement direction of the needle 210 is not limited thereto, and it may be arranged in the same direction as the thickness direction of the electrode assembly 110.

[0061] Therefore, in the method for manufacturing a battery cell according to the present embodiment, the needle portion insertion step S200 can insert at least one needle 210 at multiple positions inside the electrode assembly 110, thereby further improving the wettability of the electrode assembly 110 to the positive electrode 111 and / or the negative electrode 113, and making the wettability of the electrolyte solution based on the position of the electrode assembly 110 more uniform.

[0062] In particular, as Figure 3 shown, when at least one needle 210 is arranged in an oblique direction with respect to the thickness direction of the electrode assembly 110, each needle 210 may be arranged at different positions with respect to the thickness direction of the electrode assembly 110, so that the wettability of the electrolyte solution based on the position of the electrode assembly 110 is more uniform.

[0063] As an example, at least one needle 210 may have a bar or stick structure with a circular or square cross-section, or may have a porous structure. However, the shape of the needle 210 is not limited thereto, and the shape of the needle 210 may be a shape that does not prevent the wetting of the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 by the electrolyte solution.

[0064] As an example, at least one needle 210 may be made of a non-metallic material. As another example, at least one needle 210 may be made of a material resistant to chemicals, acids, and alkalis. However, the material of the needle 210 is not limited thereto, and the material of the needle 210 may be a material that does not react with the electrolyte solution and does not prevent the wetting of the positive electrode 111 and / or the negative electrode 113 of the electrode assembly 110 by the electrolyte solution.

[0065] In addition, as Figure 3 and Figure 4 shown, the needle part 200 may further include a connection part 250 extending in the thickness direction of the electrode assembly 110. In the needle part 200, one end of at least one needle 210 may be fixed to the connection part 250. As an example, one end of at least one needle 210 and the connection part 250 may be fixed to each other by a joining method such as welding, bonding, etc. As another example, one end of at least one needle 210 and the connection part 250 may be an integral structure fixed to each other.

[0066] Therefore, in the method for manufacturing a battery cell according to the present embodiment, the needle part 200 inserted into the electrode assembly 110 in the needle part insertion step S200 has a structure in which one end of at least one needle 210 is fixed to the connection part 250, which can help ensure that at least one needle 210 is fixed to a predetermined position. In addition, it has the advantage that in the subsequent needle part removal step S700, at least one needle 210 included in the needle part 200 can be collectively removed.

[0067] In addition, the connection part 250 may be located between the electrode assembly 110 and the sealing part 120s. As an example, if the space inside the accommodation part 123 is sufficient, the connection part 250 may be located inside the accommodation part 123 together with the electrode assembly 110. Different from this, if the space inside the accommodation part 123 is insufficient, the connection part 250 may be located outside the accommodation part 123.

[0068] Therefore, in the needle part insertion step S200 of the method for manufacturing a battery cell according to the present embodiment, the connection part 250 included in the needle part 200 is located between the electrode assembly 110 and the sealing part 120s, so that the needle part 200 can be easily inserted into the battery cell 100, and the needle part 200 can be easily removed from the battery cell 100.

[0069] However, the structure of the needle part 200 is not limited to this. Different from Figure 3 this, the structure in which the connection part 250 is omitted from the needle part 200 may also be included in the present embodiment. In addition, in the case of the structure in which the connection part 250 is omitted from the needle part 200, at least one needle 210 may be removed separately in the above-mentioned needle part removal step S700.

[0070] Referring to Figure 1, in the electrolyte injection and sealing step S300, the electrolyte solution injected into the battery cell 100 refers to a liquid electrolyte in which ions can transfer between the positive electrode and the negative electrode, and through the ion exchange between the positive electrode and the negative electrode, the battery cell 100 can be charged and discharged. As an example, the electrolyte solution may include, but is not limited to, organic liquid electrolytes, inorganic liquid electrolytes, solid polymer electrolytes, gel-type polymer electrolytes, solid inorganic electrolytes, molten inorganic electrolytes, etc.

[0071] Refer to Figure 1 and Figure 2 , in the electrolyte injection and sealing step S300, the battery cell 100 can be configured such that in a state where the needle portion 200 is inserted into the electrode assembly 110, the electrolyte solution can be sufficiently injected into the battery case 120, and then an unsealed side surface of the battery case 120 is heat-sealed to form a sealing portion 120s.

[0072] Therefore, in the method for manufacturing a battery cell according to the present embodiment, in the electrolyte injection and sealing step S300, the electrolyte solution is sufficiently injected into the battery cell 100 through an unsealed side surface of the battery cell 100, and then a sealing portion 120s is formed on the unsealed side surface of the battery cell 100 to hermetically seal the internal space of the battery cell 100.

[0073] Figure 5 is a perspective view of the battery cell in the Figure 1 degassing and needle portion removal step. Figure 6 is a perspective view of the needle removal portion and the needle portion inserted into the Figure 5 opening portion of the battery cell.

[0074] After the electrolyte injection and sealing step S300, the method may further include: an activation step of activating the battery cell, and a degassing (Degasing) and needle portion removal step S700 of removing the needle portion 200.

[0075] Refer to Figure 1 , the activation step may include: a pre-aging step S400 of storing the battery cell 100 at room temperature, a forming step S500 of performing at least one charge and discharge on the battery cell 100, and an aging step S600 of storing the battery cell 100 at a high temperature.

[0076] Here, the battery cell 100 manufactured by the battery cell manufacturing method according to the present embodiment undergoes an activation step in a state where the needle portion 200 is inserted into the electrode assembly 110. As a result, the gas generated inside the battery cell 100 during the activation step can be more effectively discharged to the outside of the electrode assembly 110, and the lithium plating (Li-Plating) and capacity reduction that may occur due to such air or gas can be more effectively prevented.

[0077] Referring to Figure 1 , Figure 2 and Figure 5 , in the degassing and needle removal step S700, cutting is performed between the sealing portion 120s of the battery case 120 and the electrode assembly 110 so that an opening 127 can be formed on one side of the battery case 120. More specifically, the battery cell 100 is cut along the first line L1 located between the sealing portion 120s of the battery case 120 and the electrode assembly 110 as shown in Figure 2 so that an opening 127 can be formed on one side of the battery cell 100 as shown in Figure 5 .

[0078] Therefore, in the battery cell manufacturing method according to the present embodiment, the degassing and needle removal step S700 can discharge the air or gas generated inside the battery cell 100 to the outside through the opening 127 formed on one side of the battery cell 100.

[0079] Referring to Figure 5 and Figure 6 , in the degassing and needle removal step S700, the needle removal portion 300 can be inserted into the opening 127 to remove the needle portion 200 from the electrode assembly 110. As an example, as shown in Figure 6 , the needle removal portion 300 contacts the needle portion 200, and as the needle removal portion 300 moves toward the opening 127, the needle portion 200 also moves accordingly, so that the needle portion 200 can be removed from the electrode assembly 110.

[0080] Therefore, in the battery cell manufacturing method according to the present embodiment, the degassing and needle removal step S700 can relatively easily remove the needle portion 200 from the electrode assembly 110 through the needle removal portion 300.

[0081] Referring to Figure 1 and Figure 2 , after the degassing and needle removal step S700, the battery cell manufacturing method according to the present embodiment may further include a pressing and rolling step S800 of pressing and rolling the outer surface of the battery cell 100.

[0082] Therefore, in the method for manufacturing a battery cell according to the present embodiment, the pressing and rolling step S800 can discharge air or gas trapped inside the electrode assembly 110, which was not removed in the degassing and needle removal step S700, to the outside through the opening 127.

[0083] Referring to Figure 1 and Figure 2 , the method for manufacturing a battery cell according to the present embodiment may include a resealing step S900 of resealing a portion cut between the sealing portion 120s of the battery case 120 and the electrode assembly 110. More specifically, the battery cell 100 may be heat-sealed along a second line L2 disposed adjacent to the accommodating portion 123 of the battery case 120 as shown in Figure 2 to seal one side of the battery case 120.

[0084] Therefore, in the method for manufacturing a battery cell according to the present embodiment, the resealing step S900 reseals one side of the battery cell 100 in a state where air or gas inside the battery cell 100 has been sufficiently removed, thereby hermetically sealing the internal space of the battery cell 100.

[0085] Although the present invention has been described in detail above with reference to the preferred embodiments of the present invention, those skilled in the art will understand that the scope of the present disclosure is not limited thereto, and various modifications and improvements can be made to these embodiments without departing from the principles and spirit of the present invention defined by the appended claims and their equivalents.

[0086] [Reference Numeral Explanation]

[0087] 100: Battery cell

[0088] 110: Electrode assembly

[0089] 111: Positive electrode

[0090] 113: Negative electrode

[0091] 115: Separator

[0092] 120: Battery case

[0093] 120s: Sealing portion

[0094] 123: Accommodating portion

[0095] 125: Outer peripheral portion

[0096] 127: Opening

[0097] 150: Electrode lead

[0098] 200: Needle portion

[0099] 210: Needle

[0100] 250: Connection part

[0101] 300: Needle removal part.

Claims

1. A method for manufacturing a battery cell, comprising: A battery cell assembly step of installing an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the positive electrode and the negative electrode into a receiving portion of a battery case; a needle inserting step of inserting the needle into the interior of the electrode assembly; and The electrolyte injection and sealing step injects an electrolyte solution into the interior of the battery case in a state where the needle portion is inserted into the electrode assembly, and then seals the battery case.

2. The method for manufacturing a battery cell according to claim 1, wherein: In the needle inserting step, The needle portion is inserted between the separator and the positive electrode disposed adjacent to each other, or between the separator and the negative electrode disposed adjacent to each other.

3. The method for manufacturing a battery cell according to claim 1, wherein: In the needle inserting step, The needle portion is inserted between the separator and the positive electrode disposed adjacent to each other, and is inserted between the separator and the negative electrode disposed adjacent to each other.

4. The method for manufacturing a battery cell according to claim 1, wherein: The needle portion is inserted into a central portion of the electrode assembly.

5. The method for manufacturing a battery cell according to claim 1, wherein: The needle portion includes at least one needle extending in a width direction of the electrode assembly.

6. The method for manufacturing a battery cell according to claim 5, wherein: The at least one needle has a thickness of 0.2 mm or more and 1 mm or less.

7. The method for manufacturing a battery cell according to claim 5, wherein: The at least one needle is arranged along an oblique direction based on a thickness direction of the electrode assembly.

8. The method for manufacturing a battery cell according to claim 5, wherein: The needle portion further includes a connecting portion extending in a thickness direction of the electrode assembly, and One end of the at least one needle is fixed to the connecting portion.

9. The method for manufacturing a battery cell according to claim 8, wherein: The connecting portion is located between the electrode assembly and the sealing portion.

10. The method for manufacturing a battery cell according to claim 1, wherein: After the electrolyte injection and sealing steps, the method further comprises: an activation step of activating the battery cell, and A degassing and needle removal step of removing gas generated inside the battery cell and removing the needle.

11. The method for manufacturing a battery cell according to claim 10, wherein: In the degassing and needle portion removing step, cutting is performed between the sealing portion of the battery case and the electrode assembly so that an opening portion is formed on one side surface of the battery case.

12. The method for manufacturing a battery cell according to claim 11, wherein: In the degassing and needle removal step, a needle removal portion is inserted into the opening portion to remove the needle portion from the electrode assembly.

13. The method for manufacturing a battery cell according to claim 10, wherein: After the degassing and needle removal steps, the method further comprises: a pressing and rolling step of pressing and rolling the outer surface of the battery cell, and A resealing step of resealing a portion cut between the sealing portion of the battery case and the electrode assembly.

14. The method for manufacturing a battery cell according to claim 10, wherein: The activation steps include: a pre-aging step of storing the battery cell at room temperature, performing at least one charge and discharge formation step on the battery cell, and An aging step of storing the battery cell at an elevated temperature.

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