Battery case, semi-assembly for secondary battery including the same, and method for manufacturing a secondary battery

Abstract

The present invention relates to a battery case, a semi-assembly for a secondary battery including the same, and a method for manufacturing a secondary battery. A battery case according to one aspect of the present invention is a battery case for housing an electrode assembly and an electrolyte, comprising: a housing section having a housing space for housing the electrode assembly; and a pocket section connected to one side of the housing section, wherein the pocket section comprises a main pocket portion having a main pocket space for housing the electrolyte; and a connecting portion providing a connecting space that connects the main pocket space and the housing space, and the connecting space may have a larger cross-sectional area than the main pocket space.

Description

Technical Field

[0001] [Cross - reference to Related Applications] This application claims the benefit of priority based on Korean Patent Application No. 10 - 2023 - 0138570 filed on October 17, 2023 and Korean Patent Application No. 10 - 2024 - 0138644 filed on October 11, 2024, and all the contents disclosed in the literature of the Korean patent applications are included as part of this specification.

[0002] The present invention relates to a battery case, a half - assembly for a secondary battery including the same, and a method of manufacturing a secondary battery.

Background Art

[0003] Recently, due to the depletion of fossil fuels, the price of energy sources has increased, and concerns about environmental pollution have amplified. The demand for environmentally friendly alternative energy sources has become an essential and indispensable factor for future life. Therefore, research on various power production technologies such as solar power, wind power, and tidal power has continued, and power storage devices such as batteries for more efficiently using the electrical energy produced in this way have also received great attention.

[0004] Furthermore, with the development of technologies and the increasing demand for electronic mobile devices and battery - powered vehicles that use batteries, the demand for batteries as an energy source has increased rapidly, and accordingly, many studies have been conducted on batteries that can meet various requirements.

[0005] Batteries have received a lot of attention as an energy source in various product groups such as mobile devices and electric vehicles. In particular, secondary batteries are excellent energy resources that can replace the use of existing products that use fossil fuels, do not generate by - products due to energy use, and have received the spotlight as an environmentally friendly energy source.

[0006] On the other hand, secondary batteries are also attracting attention as a power source for electric vehicles (EVs), hybrid electric vehicles (HEVs), and plug-in hybrid electric vehicles (Plug-In HEVs), which are being proposed as solutions to address air pollution caused by existing gasoline and diesel vehicles that use fossil fuels. In other words, such secondary batteries are used in the form of battery packs containing a large number of battery modules.

[0007] In secondary batteries, the electrolyte acts as a medium for the movement of ions in the electrodes. During the manufacturing process of secondary batteries, the electrolyte is injected and the electrodes are impregnated with it. For secondary batteries to perform and be safe, problems must be avoided if the electrolyte permeates the electrodes evenly. Conventionally, during the electrolyte injection process, enough electrolyte was injected to completely submerge the electrodes, and the pressure was adjusted to ensure that the electrodes were permeated with the electrolyte. In this case, the electrolyte permeates from the outside of the electrodes to the center, which has the problem of trapping gas in the center of the electrodes.

[0008] To address these problems, the battery manufacturing apparatus disclosed in Japanese Patent Publication No. 2014-207244 includes an under-pocket section 24 on one side of the outer casing material 2 that houses the battery element 1, which can accommodate excess electrolyte. However, in such a battery manufacturing apparatus, the portion connecting the outer casing material 2 and the under-pocket section 24 is very narrow, making it prone to a bottleneck in electrolyte flow. This not only makes it difficult for excess electrolyte to enter the under-pocket section 24, but also makes it difficult for the electrolyte contained in the under-pocket section 24 to escape into the containment space of the outer casing material 2 during the impregnation process. [Overview of the project] [Problems that the invention aims to solve]

[0009] The present invention was devised to solve the above-mentioned problems, and the object of the present invention is to provide a battery case in which the impregnation process of the electrode assembly can be carried out with high quality, a semi-assembly for a secondary battery including the same, and a method for manufacturing a secondary battery.

[0010] The problems that the present invention will address are not limited to those mentioned above, and any other problems not mentioned will be clearly understood by a person ordinary to the art to which the present invention pertains from the following description. [Means for solving the problem]

[0011] According to one aspect of the present invention, a battery case for housing an electrode assembly and an electrolyte is provided, comprising: a housing section having a housing space for housing the electrode assembly; and a pocket section connected to one side of the housing section, wherein the pocket section includes a main pocket portion having a main pocket space for housing the electrolyte; and a connecting portion providing a connecting space that connects the main pocket space and the housing space, the connecting space having a larger cross-sectional area than the main pocket space.

[0012] In this case, the cross-sectional area of ​​the connecting space can increase as it moves from the main pocket space to the storage space.

[0013] In this case, the connecting portion may have a stepped shape or a rounded shape.

[0014] In this case, the storage space has a predetermined width in one direction, and the width of the storage space may be greater than the width of the main pocket space.

[0015] In this case, the storage space has a predetermined width in one direction and a predetermined thickness in a direction perpendicular to the one direction, and the thickness of the storage space may be greater than the thickness of the main pocket space.

[0016] In this case, the other side of the housing may be provided with an opening that is open to the outside.

[0017] In this case, electrode leads extending outward through the opening may be connected to the electrode assembly.

[0018] In this case, the pocket portion can face the open portion.

[0019] In this case, the storage portion may be provided with a bottom surface facing the opening, and the pocket portion may be located between the bottom surface and the opening.

[0020] In this case, the storage space and the main pocket space are arranged at a predetermined distance from each other in one direction, and the cross-sectional area may be the area of ​​the cross-section perpendicular to that one direction.

[0021] According to another aspect of the present invention, a semi-assembly for a secondary battery for manufacturing a secondary battery is provided, comprising a battery case including an electrode assembly; a housing portion having a housing space for housing the electrode assembly; and a pocket portion connected to one side of the housing portion, wherein the pocket portion includes a main pocket portion having a main pocket space for housing an electrolyte; and a connecting portion providing a connecting space for connecting the main pocket space and the housing space, the connecting space having a larger cross-sectional area than the main pocket space.

[0022] In this case, the electrode assembly may be supported by the connecting portion.

[0023] In this case, the electrode assembly has a predetermined width in one direction, and the width of the main pocket space may be smaller than the width of the electrode assembly.

[0024] In this case, the electrode assembly has a predetermined width in one direction and a predetermined thickness in a direction perpendicular to the one direction, and the thickness of the main pocket space may be less than the thickness of the electrode assembly.

[0025] According to another aspect of the present invention, there is provided a method for manufacturing a secondary battery, including the steps of: disposing an electrode assembly in the accommodation space of a battery case including an accommodation part having an accommodation space and a pocket part connected to one side of the accommodation part; injecting an electrolyte into the interior of the battery case; reducing the pressure of the battery case so that the electrolyte is impregnated into the electrode assembly; and a sealing step of sealing the battery case. In the step of injecting the electrolyte, at least a part of the electrolyte is accommodated in the pocket part of the battery case.

[0026] At this time, in the step of reducing the pressure, the electrolyte accommodated in the pocket part may be moved to the accommodation space.

[0027] At this time, in the step of injecting the electrolyte, the electrolyte may be injected so that a part of the electrode assembly is immersed in the electrolyte.

[0028] At this time, the method may further include an additional sealing step of additionally sealing the boundary between the accommodation part and the pocket part; and a removing step of removing the pocket part.

[0029] At this time, the pocket part includes a main pocket part having a main pocket space in which the electrolyte can be accommodated; and a connecting part providing a connecting space for communicating the main pocket space and the accommodation space, and the connecting space may have a cross-sectional area wider than the main pocket space.

Advantages of the Invention

[0030] According to one aspect of the present invention, the cross-sectional area of the connecting space connecting the accommodation space and the main pocket space is configured to be wider than the main pocket space, and the electrolyte can easily flow between the accommodation space and the main pocket space. Thereby, the electrolyte accommodated in the main pocket space can smoothly move in the accommodation space to impregnate the electrode assembly, so that the impregnation process can be performed with high quality.

[0031] The effects of the present invention are not limited to those described above, and any effects not mentioned herein should be clearly understood by a person with ordinary skill in the art to which the present invention pertains from this specification and the accompanying drawings. [Brief explanation of the drawing]

[0032] [Figure 1] This is a view from the front of a semi-assembled secondary battery according to the first embodiment of the present invention. [Figure 2] This is an enlarged view of section A in Figure 1. [Figure 3] This is a side view of a semi-assembled secondary battery according to the first embodiment of the present invention. [Figure 4] This is an enlarged view of section B in Figure 3. [Figure 5] This is a view from the front of a semi-assembled secondary battery according to a second embodiment of the present invention. [Figure 6] This is a front view of a semi-assembled secondary battery according to a third embodiment of the present invention. [Figure 7] This is a flowchart of a method for manufacturing a secondary battery according to one embodiment of the present invention. [Figure 8] This is a diagram illustrating the S2 stage in Figure 7. [Figure 9] Figure 7 shows a view from the front of the rising water level of the impregnation liquid injected into the battery case during stage S3. [Figure 10] This figure shows a side view of the rising water level of the impregnation liquid injected into the battery case during stage S3 of Figure 7. [Figure 11] Figure 7 shows the state in which the electrode assembly housed in the battery case is completely impregnated at stage S3. [Figure 12] This figure explains stages S5 and S6 in Figure 7.

[0033] In this case, the battery case is shown in cross-section in Figures 1 to 6 and Figures 8 to 12. [Modes for carrying out the invention]

[0034] Preferred embodiments of the present invention will be described in detail so that they can be easily implemented by those with the necessary knowledge. However, the present invention may be embodied in a variety of different forms and is not limited to or restricted by the following embodiments.

[0035] In order to clearly explain the present invention, detailed descriptions of relevant prior art that are not relevant to the description or that could unnecessarily obscure the gist of the invention have been omitted. In this specification, when assigning reference numerals to components in each figure, the same or similar reference numerals are assigned to components that are the same or similar throughout the specification.

[0036] Furthermore, the terms and words used in this specification and the claims shall not be interpreted to be limited to their ordinary or dictionary meanings, but rather to be interpreted in a way that is consistent with the technical idea of ​​the present invention, in accordance with the principle that inventors may define the concepts of terms as appropriate to best describe their invention.

[0037] In the following, a semi-assembly for a secondary battery according to the first embodiment of the present invention (hereinafter referred to as the semi-assembly) will be described.

[0038] Figure 1 is a front view of a semi-assembly for a secondary battery according to the first embodiment of the present invention. Figure 2 is an enlarged view of portion A in Figure 1. Figure 3 is a side view of the semi-assembly for a secondary battery according to the first embodiment of the present invention. Figure 4 is an enlarged view of portion B in Figure 3.

[0039] Referring to Figures 1 to 4, the semi-assembly 1 according to the first embodiment of the present invention may be a semi-assembly for manufacturing a secondary battery. In this embodiment, the semi-assembly 1 may include an electrode assembly 10. The electrode assembly 10 may be an assembly having a charge-discharge function.

[0040] Therefore, the electrode assembly 10 can have a structure in which multiple electrodes and separation membranes are sequentially stacked. The electrode assembly 10 may be stacked, stacked and folded, or cylindrical, but the type and shape of the electrode assembly 10 are not particularly limited.

[0041] In this embodiment, the electrode assembly 10 may have a predetermined width w_10 in one direction. In this case, the one direction may be a direction aligned with the Y-axis with reference to Figure 1. The electrode assembly 10 may have a predetermined thickness t_10 in another direction perpendicular to the one direction. In this case, the other direction may be a direction aligned with the X-axis with reference to Figure 3.

[0042] On the other hand, in this embodiment, electrode leads 12 may be connected to the electrode assembly 10. The electrode leads 12 may be leads for conducting electricity to the electrode assembly 10 with an external configuration. The electrode leads 12 may consist of a film or busbar made of a conductive material, but their type and structure are not particularly limited.

[0043] In this embodiment, the electrode leads 12 may consist of a pair. One of the pair of electrode leads 12 may be a negative electrode lead connected to the negative electrode of the electrode assembly 10, and the other may be a positive electrode lead connected to the positive electrode of the electrode assembly 10.

[0044] In this case, the electrode lead 12 may extend from the inside to the outside of the battery case 20 through an opening 21 of the battery case 20, which will be described later. This allows the electrode assembly 10 housed inside the battery case 20 to be energized with the outside via the electrode lead 12.

[0045] Referring to Figures 1 to 4, the semi-assembly 1 according to the first embodiment of the present invention may include a battery case 20. The battery case 20 may be a case for housing the electrode assembly 10 and electrolyte described above. The battery case 20 may be a pouch-type battery case made of a film-shaped pouch.

[0046] At this time, the electrode assembly 10 may be impregnated with the electrolyte contained within it. The electrolyte can perform the function of mediating the movement of ions contained in the electrodes of the electrode assembly 10. Therefore, in the manufacturing process of a secondary battery using the semi-assembly 1, it is important that the electrode assembly 10 is properly impregnated with the electrolyte.

[0047] On the other hand, in this embodiment, the battery case 20 may include a housing section 22. The housing section 22 may be configured to provide a housing space 23. The electrode assembly 10 may be placed in the housing space 23.

[0048] In this case, the accommodation space 23 can have a width w_23 and a thickness t_23 that are larger than the electrode assembly 10 so as to accommodate the electrode assembly 10. Furthermore, the accommodation space 23 can have a length longer than the electrode assembly 10 in the vertical direction (Z-axis direction). The shape of the accommodation section 22 and the accommodation space 23 is not particularly limited as long as they can accommodate the electrode assembly 10.

[0049] On the other hand, in this embodiment, the housing section 22 may be provided with an opening section 21. The opening section 21 may be a portion that is open to the outside. The housing space 23 may be in communication with the outside through the opening section 21.

[0050] In the illustrated embodiment, the opening 21 may be provided on the upper side (positive Z-axis direction) of the housing 22. The electrolyte may be injected into the housing space 23 through such an opening 21. The opening 21 may be sealed in a subsequent step.

[0051] Referring to Figures 2 and 4, the battery case 20 of the semi-assembly 1 according to one embodiment of the present invention may include a pocket portion 24 extending from the housing portion 22. The pocket portion 24 may be configured to accommodate excess electrolyte.

[0052] For this reason, the pocket portion 24 may be provided with a pocket space 25. During the impregnation process, the electrolyte contained in the pocket space 25 can be moved to the containment space 23 to impregnate the electrode assembly 10.

[0053] In this embodiment, the pocket portion 24 may be connected to the lower (negative Z-axis direction) portion of the housing portion 22. Alternatively, the pocket portion 24 may be positioned so as to face the opening portion 21 with respect to the housing portion 22. This allows the electrolyte injected through the opening portion 21 to flow downward due to gravity and fill the pocket space 25 of the battery case 20.

[0054] Thus, in the semi-assembly 1 according to one embodiment of the present invention, the battery case 20 is further provided with extra space (i.e., pocket space) than in the conventional invention, so even if the same positive electrolyte as in the conventional invention is injected, the electrolyte level may be lower than in the conventional invention. In other words, a part of the electrode assembly 10 may be immersed in the electrolyte, while the rest may not be immersed.

[0055] This prevents gases and other substances that could not escape from the central part of the electrode assembly 10 from being collected. This can improve the quality of the impregnation process. This will be explained in detail along with a method for manufacturing a secondary battery according to one embodiment of the present invention.

[0056] In the following, the pocket portion 24 of the battery case 20 according to the first embodiment of the present invention will be specifically described. Referring to Figures 2 and 4, in this embodiment, the pocket portion 24 may include a main pocket portion 26, and the pocket space 25 may include a main pocket space 27 provided inside the main pocket portion 26.

[0057] In this embodiment, the main pocket space 27 may mainly contain an electrolyte. The main pocket portion 26 may be arranged at a predetermined distance from the storage portion 22 in the vertical direction (Z-axis direction). The main pocket portion 26 may have a cylindrical shape that is open to the storage portion 22 side. The main pocket space 27 may be in communication with the storage space 23 via a connecting space 29, which will be described later.

[0058] In this case, the main pocket space 27 may have a width w_27 smaller than the storage space 23. The main pocket space 27 may have a thickness t_27 smaller than the storage space 23. Alternatively, the main pocket space 27 may have a width w_27 smaller than the electrode assembly 10. The main pocket space 27 may have a thickness t_27 smaller than the electrode assembly 10. This can prevent the electrode assembly 10 from entering the main pocket space 25.

[0059] In this embodiment, the pocket portion 24 may include a connecting portion 28. The connecting portion 28 may be provided between the main pocket portion 26 and the storage portion 22. The connecting portion 28 can provide a connecting space 29. The connecting space 29 can connect the main pocket space 27 and the storage space 23. This allows electrolyte that has entered the storage space 23 to flow into the main pocket space 27.

[0060] According to this embodiment, the connecting space 29 may have a larger cross-sectional area than the main pocket space 27. This may be to allow the electrolyte to flow smoothly through the containment space 23 and the main pocket space 27. This can expedite the impregnation process of the electrode assembly 10.

[0061] In this embodiment, the cross-sectional area may be the area of ​​a cross-section perpendicular to the vertical direction (Z-axis direction) where the main pocket space 27 and the housing portion 22 are separated. The cross-section may be a cross-section parallel to the X-axis and Y-axis with reference to Figures 2 and 4.

[0062] In this embodiment, the cross-sectional area of ​​the connecting portion 28 may increase as it moves from the main pocket portion 26 towards the storage portion 22. As shown in the figure, the connecting portion 28 may be rounded. The cross-sectional area of ​​the connecting space 29 may gradually increase as it moves towards the storage portion 22.

[0063] As a result, the lower part of the electrode assembly 10 is supported by the connecting portion 28, while smooth flow can occur between the main pocket space 27 and the containment space 23.

[0064] Of course, the shape of the connecting portion 28 may be appropriately modified as needed. For example, the connecting portion 28 may have a stepped shape (or a staircase shape). In such a case, the cross-sectional area of ​​the connecting space 29 can increase gradually from the main pocket space 27 towards the storage space 23.

[0065] Thus, in the semi-assembly 1 according to one embodiment of the present invention, the electrolyte can flow smoothly between the pocket space 25 and the containment space 23. This allows the electrolyte impregnation process by the pocket portion 24 to be carried out more effectively.

[0066] The following describes a semi-assembly according to another embodiment of the present invention. In describing the semi-assembly according to another embodiment of the present invention, the differences from the semi-assembly according to the first embodiment of the present invention described above will be the main focus.

[0067] Figure 5 is a front view of a semi-assembled secondary battery according to the second embodiment of the present invention. Figure 6 is a front view of a semi-assembled secondary battery according to the third embodiment of the present invention.

[0068] Figure 5 discloses a semi-assembly according to a second embodiment of the present invention. Referring to Figure 5, the pocket portion 124 of the semi-assembly 101 according to this embodiment may be provided on the shaft portion in the width direction (Y-axis direction) of the electrode assembly 10.

[0069] To put it another way, the pocket portion 124 may be located between the bottom surface 22a of the storage portion 22 and the opening portion 21. Here, the bottom surface 22a may be the surface on the inner surface of the storage portion 22 that faces the opening portion 21.

[0070] Figure 6 discloses a semi-assembly according to a third embodiment of the present invention. Referring to Figure 6, the electrode lead 112 of the semi-assembly 201 according to this embodiment may be provided on one side in the width direction (Y-axis direction) of the electrode assembly 110. The electrode lead 112 may penetrate one side in the width direction (Y-axis direction) of the housing portion 22 and extend to the outside of the battery case 20.

[0071] On the other hand, in this embodiment, the length of the electrode assembly 10 in the width direction (Y-axis direction) is shown to be longer than the length in the vertical direction (Z-axis direction). However, the relative size and ratio of the width direction length and the vertical direction length of the electrode assembly 10 are not particularly limited.

[0072] The following describes a method for manufacturing a secondary battery according to one embodiment of the present invention (hereinafter referred to as the manufacturing method).

[0073] Figure 7 is a flowchart of a method for manufacturing a secondary battery according to one embodiment of the present invention. Figure 8 is a diagram illustrating step S2 of Figure 7. Figure 9 is a front view of the rising water level of the impregnation liquid injected into the battery case in step S3 of Figure 7. Figure 10 is a side view of the rising water level of the impregnation liquid injected into the battery case in step S3 of Figure 7. Figure 11 shows the state in which the electrode assembly housed in the battery case is completely impregnated by step S3 of Figure 7. Figure 12 is a diagram illustrating steps S5 and S6 of Figure 7.

[0074] A manufacturing method according to one embodiment of the present invention may be a method for manufacturing a secondary battery using a semi-assembly according to the embodiment of the present invention described above. In the following description, it is assumed that a secondary battery is manufactured using a semi-assembly according to the first embodiment of the present invention.

[0075] Referring to Figures 7 to 12, the method for manufacturing a battery cell according to the present invention may include a placement step S1 in which the electrode assembly 10 is placed inside the battery case 20, an injection step S2 in which an electrolyte is injected, a depressurization step S3 in which the electrolyte is impregnated into the electrode assembly 10, and a sealing step S4 in which the battery case 20 is sealed.

[0076] Referring to Figures 7 and 8, in step S1, where the electrode assembly 10 is placed inside the battery case 20, the electrode assembly 10 can be placed in the housing section 22. The electrode leads connected to the electrode assembly 10 can be positioned so that they are exposed towards the open section 21.

[0077] Referring to Figures 7 to 11, in the injection step S2 in which the electrolyte is injected, the electrolyte can be injected into the housing portion 22 of the battery case 20 through the opening 21 formed in the battery case 20. At this time, in the injection step S2, a portion of the electrolyte may be contained in the pocket portion 24 of the battery case 20.

[0078] In injection step S2, the electrolyte may be injected such that a portion of the electrode assembly 10 is submerged while the rest is not. Since the electrolyte is also contained in the pocket portion 24, the electrode assembly 10 may not be completely submerged in the electrolyte. The water level of the electrolyte contained in the containment portion 22 may be determined according to the size of the pocket portion 24, that is, the volume of electrolyte that can be contained in the pocket portion 24.

[0079] In the depressurization step S3, when the electrolyte is impregnated into the electrode assembly 10, the pressure in the housing 22 may be reduced to allow the electrolyte to seep into the electrode assembly 10. Alternatively, the pressure in the housing 22 may be gradually reduced to allow the electrolyte to be impregnated into the electrode assembly 10 under vacuum conditions.

[0080] During the depressurization stage S3, the electrolyte contained in the pocket portion 24 can seep into the electrode assembly 10. At this time, the pocket portion 24 shrinks, reducing the volume of the pocket space 25, and the electrolyte may be pushed into the containment space 23. Consequently, the electrolyte that was in the pocket portion 24 seeps into the electrode assembly 10, and the pocket portion 24 may become somewhat empty.

[0081] In the depressurization step S3 of the manufacturing method according to this embodiment, the electrolyte can seep in from the surface where the pocket portion 23 is formed toward the open portion 21 of the battery case 20. In the injection step S2, a portion of the electrode assembly 10 becomes submerged.

[0082] Due to gravity, the electrolyte fills the area from the opposite side of where the opening 21 is formed. Therefore, when the pressure in the storage area 22 is reduced, the electrolyte gradually seeps in from the area where the pocket 24 is formed towards the direction where the opening 21 was formed.

[0083] As a result, when the electrode assembly 10 is impregnated with the electrolyte, the electrolyte does not seep into the electrode assembly 10 from the outer part to the central part, but rather the impregnation may begin from the part of the electrode assembly 10 that is immersed in the electrolyte.

[0084] As the electrolyte level rises, the area of ​​the electrode assembly 10 immersed in the electrolyte expands, allowing the electrolyte to gradually seep into the electrode assembly 10.

[0085] During this process, any gas remaining inside the electrode assembly 10 can be pushed out and escaped by the electrolyte, reaching the parts not immersed in it. This prevents the accumulation of gas and other substances that could not escape in the central part of the electrode assembly 10. This improves the quality of the impregnation process.

[0086] Referring to Figures 7 and 12, the method for manufacturing a battery cell according to the present invention may further include an additional sealing step S5 and a removal step S6. In the additional sealing step S5, the boundary between the housing portion 22 and the pocket portion 24 can be additionally sealed. This can form a pocket sealing portion 24'.

[0087] As the electrolyte soaks into the electrode assembly 10, the pocket portion 24 becomes somewhat empty, so the boundary between the housing portion 22 and the pocket portion 24 can be sealed to break the connection between the housing portion 22 and the pocket portion 24.

[0088] In removal step S6, the pocket section 24 can be removed. Since the storage section 22 and the pocket section 24 are sealed, the two spaces can become completely independent spaces. After sealing, the pocket section 24 is no longer needed, so it can be removed to secure additional space.

[0089] Therefore, the battery case 20 can be cut along the incision line L to remove the pocket portion 24. Thus, the pocket portion 24 does not affect the overall size of the battery cell 1. The incision line L can also cross the pocket sealing portion 24', or it can be located to some extent outside the pocket sealing portion 24'.

[0090] On the other hand, the manufacturing method according to one embodiment of the present invention was described as manufacturing a secondary battery using a semi-assembly according to the embodiment of the present invention described above. However, the manufacturing method according to one embodiment of the present invention may also be applied to the process of manufacturing a secondary battery using other structures or types of semi-assemblies, including a battery case equipped with a pocket portion capable of containing an electrolyte.

[0091] The present invention is not limited by the limited embodiments and drawings described herein, and can be implemented in various ways by a person with ordinary skill in the art to which the present invention pertains, within the equivalent scope of the technical concept of the present invention and the claims described below. [Explanation of Symbols]

[0092] 1, 101, 201: Secondary battery subassembly 10, 110: Electrode assembly 12, 112: Electrode leads 20, 120: Battery case 22, 222: Storage Unit 23, 223: Containment space 24, 124: Pocket section 24': Pocket sealing section 15, 125: Pocket Space F: Electrolyte L: Incision line

Claims

1. A battery case for housing an electrode assembly and an electrolyte, A housing section having a housing space for housing the electrode assembly; and Including a pocket portion connected to one side of the aforementioned storage portion, The aforementioned pocket portion is A main pocket portion having a main pocket space for containing the aforementioned electrolyte; and Includes a connecting portion that provides a connecting space that connects the main pocket space and the storage space, The aforementioned connecting space is a battery case having a larger cross-sectional area than the aforementioned main pocket space.

2. The battery case according to claim 1, wherein the cross-sectional area of ​​the connecting space increases as you move from the main pocket space to the storage space.

3. The battery case according to claim 1, wherein the connecting portion has a stepped shape or a rounded shape.

4. The aforementioned storage space has a predetermined width in one direction, The battery case according to claim 1, wherein the width of the storage space is greater than the width of the main pocket space.

5. The aforementioned storage space has a predetermined width in one direction and a predetermined thickness in a direction perpendicular to the aforementioned direction. The battery case according to claim 1, wherein the thickness of the storage space is greater than the thickness of the main pocket space.

6. The battery case according to claim 1, wherein the other side of the housing is provided with an opening that is open to the outside.

7. The battery case according to claim 6, wherein electrode leads extending outward through the opening are connected to the electrode assembly.

8. The battery case according to claim 6, wherein the pocket portion faces the opening portion.

9. The aforementioned storage section is provided with a bottom surface facing the aforementioned opening, The battery case according to claim 6, wherein the pocket portion is located between the bottom surface and the opening portion.

10. The aforementioned storage space and the main pocket space are arranged at a predetermined distance from each other in one direction. The battery case according to claim 1, wherein the cross-sectional area is the area of ​​the cross-section perpendicular to the one direction.

11. A semi-assembly for secondary batteries for manufacturing secondary batteries, Electrode assembly; and The battery case includes a housing section having a housing space for housing the electrode assembly and a pocket section connected to one side of the housing section, The aforementioned pocket portion is A main pocket portion having a main pocket space for containing the electrolyte; and Includes a connecting portion that provides a connecting space that connects the main pocket space and the storage space, The aforementioned connecting space has a larger cross-sectional area than the main pocket space, and is a semi-assembly for a secondary battery.

12. The electrode assembly is supported by the connecting portion, as described in claim 11.

13. The electrode assembly has a predetermined width in one direction, The semi-assembly for a secondary battery according to claim 11, wherein the width of the main pocket space is smaller than the width of the electrode assembly.

14. The electrode assembly has a predetermined width in one direction and a predetermined thickness in a direction perpendicular to the one direction. The semi-assembly for a secondary battery according to claim 11, wherein the thickness of the main pocket space is smaller than the thickness of the electrode assembly.

15. A step of arranging an electrode assembly in the housing space of a battery case, which includes a housing section having a housing space and a pocket section connected to one side of the housing section; The step of injecting electrolyte into the battery case; A step of reducing the pressure in the battery case so that the electrolyte is impregnated into the electrode assembly; and This includes a sealing step of sealing the battery case, A method for manufacturing a secondary battery, wherein, in the step of injecting the electrolyte, at least a portion of the electrolyte is contained in the pocket portion of the battery case.

16. In the step of reducing the pressure, the electrolyte contained in the pocket is moved to the containment space, as described in claim 15.

17. The method for manufacturing a secondary battery according to claim 15, wherein, in the step of injecting the electrolyte, a portion of the electrode assembly is injected so as to be immersed in the electrolyte.

18. An additional sealing step of additionally sealing the boundary between the housing portion and the pocket portion; and The method for manufacturing a secondary battery according to claim 15, further comprising a removal step of removing the aforementioned pocket portion.

19. The aforementioned pocket portion is A main pocket portion having a main pocket space in which the electrolyte can be contained; and Includes a connecting portion that provides a connecting space that connects the main pocket space and the storage space, The method for manufacturing a secondary battery according to claim 15, wherein the connecting space has a wider cross-sectional area than the main pocket space.

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