O-ring for preventing leakage of electrolyte

Abstract

An O-ring according to one embodiment of the present invention comprises a first part that is seated on a beading portion into which a battery housing is inserted, and a second part that is provided above the first part and configured to cover the upper surface of the battery housing.

Description

Technology Field

[0001] The present invention relates to an O-ring for preventing electrolyte leakage. Background Technology

[0002] Secondary batteries, which possess electrical characteristics such as high energy density and high applicability across product groups, are widely applied not only to portable devices but also to electric vehicles (EVs) or hybrid electric vehicles (HEVs) powered by electric sources. These secondary batteries are attracting attention as a new energy source for enhancing eco-friendliness and energy efficiency, as they possess not only the primary advantage of drastically reducing the use of fossil fuels but also the advantage of generating no by-products from energy use.

[0003] Currently, widely used types of secondary batteries include lithium-ion batteries, lithium-polymer batteries, nickel-cadmium batteries, nickel-hydrogen batteries, and nickel-zinc batteries. The operating voltage of these unit secondary battery cells, or unit battery cells, is approximately 2.5V to 4.5V. Therefore, if a higher output voltage is required, multiple battery cells are connected in series to form a battery pack. Additionally, depending on the charge / discharge capacity required for the battery pack, multiple battery cells are connected in parallel to form a battery pack. Accordingly, the number of battery cells included in the battery pack can be varied depending on the required output voltage and / or charge / discharge capacity.

[0004] Meanwhile, when manufacturing cylindrical secondary batteries, an electrolyte injection process is performed after inserting the electrode assembly into the battery housing to activate it. At this time, an O-ring is installed to prevent the electrolyte from leaking outside the battery housing during injection; however, conventional O-rings had a problem in which electrolyte leakage occurred due to reduced leakage performance caused by contact with the battery housing. The problem to be solved

[0005] Accordingly, the present invention aims to provide an O-ring capable of preventing the electrolyte from leaking to the outside of the battery housing when the electrolyte is injected into a cylindrical battery cell in order to solve the above problem.

[0006] More specifically, the present invention aims to increase sealing characteristics by expanding the contact area between the battery housing and the O-ring.

[0007] However, the technical problems that the present invention aims to solve are not limited to those described above, and other unmentioned problems will be clearly understood by those skilled in the art from the description of the invention below. means of solving the problem

[0008] An O-ring according to one embodiment of the present invention for solving the above-described problem comprises: a first part that is seated on a beading portion into which a battery housing is inserted; and a second part that is provided above the first part and configured to cover the upper surface of the battery housing.

[0009] In one aspect of the present invention, the first part may be configured in a cylindrical shape.

[0010] In another aspect of the present invention, the O-ring may have elasticity.

[0011] Preferably, the O-ring may include at least one of NBR, VMQ, FKM, and FPM.

[0012] In another aspect of the present invention, the O-ring may include a fluid injection hole penetrating in the vertical direction at the center.

[0013] In one aspect of the present invention, the O-ring may have a groove into which a hopper capable of pressurizing the O-ring can be fitted.

[0014] In another aspect of the present invention, the outer surface of the first part may be configured to be spaced apart from the inner surface of the battery housing by a predetermined distance.

[0015] Preferably, the outer surface of the first part may be configured to be spaced 0.2 to 0.8 mm apart from the inner surface of the battery housing.

[0016] In another aspect of the present invention, the lower surface of the second part may be configured to be spaced apart from the upper surface of the battery housing by a predetermined distance.

[0017] In one aspect of the present invention, the O-ring may include a pressure surface provided on the inside or outside of the O-ring and configured to be pressed downward by the hopper.

[0018] Preferably, when the pressure surface is pressed downward, the first part may be configured to be compressed in the vertical direction and have its width increased in the radial direction.

[0019] In another aspect of the present invention, when the pressurized surface is pressed downward, the second part may be configured to move downward and come into contact with the upper surface of the battery housing.

[0020] In another aspect of the present invention, when pressure is applied from the outside of the battery housing toward the beading portion of the battery housing, the O-ring may be configured to block the outside and the inside of the battery housing.

[0021] In another aspect of the present invention, the thickness of the first part may alternately increase and decrease along the circumferential direction. Effects of the invention

[0022] According to the present invention, when an electrolyte is injected into a cylindrical battery cell, leakage of the electrolyte to the outside of the battery housing can be prevented.

[0023] In addition, according to the present invention, the contact area between the battery housing and the O-ring can be expanded.

[0024] Accordingly, according to the present invention, the sealing performance of the battery cell can be improved when injecting the electrolyte.

[0025] However, the effects obtainable through the present invention are not limited to those described above, and other unmentioned technical effects will be clearly understood by those skilled in the art from the description of the invention below. Brief explanation of the drawing

[0026] The following drawings attached to this specification illustrate preferred embodiments of the present invention and serve to further enhance understanding of the technical concept of the present invention together with the detailed description of the invention provided below; therefore, the present invention should not be interpreted as being limited only to the matters described in such drawings. FIG. 1 is a drawing for illustrating a battery cell according to one embodiment of the present invention. Figure 2 is a longitudinal perspective view of Figure 1. Figure 3 is a cross-sectional view of the battery cell of Figure 1. Figure 4 is a drawing illustrating a conventional O-ring. Figure 5 is a diagram illustrating the state of a conventional O-ring before compression. Figure 6 is a drawing illustrating the state of a conventional O-ring after compression. FIG. 7 is a drawing for illustrating an O-ring according to one embodiment of the present invention. Figure 8 is a diagram illustrating the state of the O-ring of Figure 7 before it is compressed. Figure 9 is an enlarged view of a part of Figure 8. Figure 10 is a diagram illustrating the state of the O-ring of Figure 7 after it has been compressed. FIG. 11 is a drawing for illustrating an O-ring according to another embodiment of the present invention. FIG. 12 is a drawing for illustrating an O-ring according to another embodiment of the present invention. FIG. 13 is a drawing for illustrating an O-ring according to another embodiment of the present invention. Specific details for implementing the invention

[0027] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. Prior to this, terms and words used in this specification and claims should not be interpreted as being limited to their ordinary or dictionary meanings, but should be interpreted in a meaning and concept consistent with the technical spirit of the present invention, based on the principle that the inventor can appropriately define the concept of the terms to best describe his invention. Accordingly, the embodiments described in this specification and the configurations illustrated in the drawings are merely some of the most preferred embodiments of the present invention and do not represent all of the technical spirit of the present invention; therefore, it should be understood that various equivalents and modifications capable of replacing them may exist at the time of filing this application.

[0028] Additionally, to aid in understanding the invention, the attached drawings are not drawn to actual scale, and the dimensions of some components may be exaggerated. Furthermore, the same reference numerals may be assigned to identical components in different embodiments.

[0029] The statement that two subjects of comparison are identical means that they are 'substantially identical.' Therefore, substantial identity may include deviations considered low in the industry, for example, deviations within 5%. Additionally, the statement that a parameter is uniform in a given area may mean that it is uniform from an average perspective.

[0030] Although terms such as "first," "second," etc., are used to describe various components, it goes without saying that these components are not limited by these terms. These terms are used merely to distinguish one component from another, and unless specifically stated otherwise, the first component may also be the second component.

[0031] Throughout the specification, unless specifically stated otherwise, each component may be singular or plural.

[0032] The fact that any configuration is placed on the "upper (or lower)" of a component or on the "upper (or lower)" of a component may mean not only that any configuration is placed in contact with the upper (or lower) surface of said component, but also that another configuration may be interposed between said component and any configuration placed on (or below) said component.

[0033] In addition, where it is stated that one component is "connected," "combined," or "connected" to another component, it should be understood that while the components may be directly connected or connected to each other, another component may be "interposed" between each component, or each component may be "connected," "combined," or "connected" through another component.

[0034] Throughout the specification, "A and / or B" means A, B, or A and B unless specifically stated otherwise, and "C to D" means C or more and D or less unless specifically stated otherwise.

[0036] FIG. 1 is a drawing for explaining a battery cell (1) according to an embodiment of the present invention, and FIG. 2 is a cross-sectional perspective view of FIG. 1. FIG. 3 is a cross-sectional view of the battery cell (1) of FIG. 1.

[0037] Referring to FIG. 1, a battery cell (1) according to one embodiment of the present invention comprises an electrode assembly (10), a battery housing (20), and a current collector (30). The battery cell (1) may further comprise a housing cover (40) and / or a terminal (50) and / or a second current collector (60). The present invention is not limited by the shape of the battery and is applicable to batteries of other shapes, such as prismatic batteries.

[0038] The electrode assembly (10) comprises a first uncoated portion (11) and a second uncoated portion (12). More specifically, the electrode assembly (10) has a structure in which the first electrode and the second electrode and the separator interposed between them are wound around a winding axis with a separator interposed between them, thereby defining a core and an outer surface. That is, the electrode assembly (10) applied to the present invention may be a jelly-roll type electrode assembly (10). The electrode assembly (10) may be wound around a winding center hole (H1). In this case, an additional separator may be provided on the outer surface of the electrode assembly (10) to provide insulation from the battery housing (20). The electrode assembly (10) may have a winding structure well known in the art without limitation. Meanwhile, in the present invention, the positive active material coated on the positive plate and the negative active material coated on the negative plate may be used without limitation as long as they are active materials known in the art.

[0040] Referring to FIG. 1, the battery housing (20) is a roughly cylindrical receptacle with an opening formed on one side and is made of a conductive metal material. The side of the battery housing (20) and the bottom surface located opposite the opening are generally formed as a single unit. That is, the battery housing (20) generally has an open top in the height direction and a closed bottom. The bottom surface of the battery housing (20) may have a roughly flat shape. The bottom surface of the battery housing (20) may form the outer surface (20a) of the closed portion. In this case, the outer surface (20a) of the closed portion may function as a second electrode terminal.

[0041] The battery housing (20) accommodates an electrode assembly (10) through an opening formed on one side in the height direction. The battery housing (20) can also accommodate an electrolyte through the opening. The upper surface (25) of the battery housing (20) constituting the opening can be folded horizontally by a crimping process after the electrolyte is injected.

[0042] The battery housing (20) may have a beading portion (21) formed at an end adjacent to an opening provided at the top of the battery housing (20). The battery housing (20) may further have a crimping portion (22) formed on the beading portion (21). The beading portion (21) has a shape in which the outer circumference of the battery housing (20) is recessed to a predetermined depth. More specifically, the beading portion (21) may have a shape in which it is recessed inward in the area between an opening formed on one side of the battery housing (20) and a receiving portion that accommodates the electrode assembly (10).

[0043] The beading portion (21) may provide a support surface on which at least a portion of the edge perimeter of the current collector (30), which will be described later, can be seated and joined. That is, at least a portion of the edge perimeter of the current collector (30) of the present invention and / or the edge perimeter of the housing cover (40) may be seated on the upper surface of the beading portion (21). In order to stably support at least a portion of the edge perimeter of the current collector (30), the upper surface of the beading portion (21) may have a shape that extends along a direction approximately parallel to the lower surface of the battery housing (20), that is, along a direction approximately perpendicular to the side wall of the battery housing (20).

[0045] Referring to FIGS. 1 to 3, a current collector (30) according to one embodiment of the present invention is housed inside a battery housing (20), is electrically connected to an electrode assembly (10), and is also electrically connected to the battery housing (20). That is, the current collector (30) electrically connects the electrode assembly (10) and the battery housing (20). The current collector (30) includes a support member (31) located on one side of the electrode assembly (10), a tab coupling member (32) extending from the support member (31) and coupled to a first non-supporting member (11), and a housing coupling member (33) extending from the support member (31) and coupled to the inner surface of the battery housing (20). The current collector (30) may include a current collector hole (H2) in the center for injecting an electrolyte.

[0046] The housing coupling portion (33) may include a contact portion (33a) coupled to the inner surface of the battery housing (20) and a connecting portion (33b) connecting the support portion (31) and the contact portion (33a). In one aspect of the present invention, the first tab coupling portion (32) may have a greater width than the connecting portion (33b). In another aspect of the present invention, the contact portion (33a) may have a greater width than the connecting portion (33b).

[0047] The contact portion (33a) is coupled to the inner surface of the battery housing (20). Preferably, the contact portion (33a) may be coupled to the beading portion (21) of the battery housing (20). In this case, for stable contact and coupling, both the beading portion (21) and the contact portion (33a) may have a shape that extends along a direction approximately parallel to the lower surface of the battery housing (20), that is, a direction approximately perpendicular to the side wall of the battery housing (20).

[0049] FIG. 4 is a drawing for explaining a conventional O-ring (100). FIG. 5 is a drawing for explaining the state of the conventional O-ring (100) before compression, and FIG. 6 is a drawing for explaining the state of the conventional O-ring (100) after compression.

[0050] Generally, the battery housing (20) of a cylindrical battery cell undergoes an electrolyte injection process for activation after the electrode assembly (10) is inserted. At this time, an O-ring (100) is installed to prevent the electrolyte from leaking out of the battery housing (20) during the electrolyte injection process. However, in the case of a conventional O-ring (100), electrolyte leakage occurs due to a decrease in sealing performance, such as electrolyte leakage caused by contact with the battery housing (20).

[0051] For example, a conventional O-ring (100) is placed on the contact portion (33a) of the housing coupling portion (33) that is seated on the beading portion (21). At this time, when the O-ring (100) is compressed in the height direction of the battery cell, that is, in the winding axis direction of the electrode assembly (10), the shape of the O-ring (100) is deformed by elasticity. For example, as shown in FIG. 5, when the O-ring (100) is seated on the beading portion (21) and the O-ring (100) is pressed downward, the O-ring (100) is compressed in the vertical direction as shown in FIG. 6, and its shape is deformed. Consequently, as shown in FIG. 6, the contact area of ​​the O-ring (100) with the current collector (30) and / or the battery housing (20) is reduced. That is, since the O-ring (100) is in line contact with the current collector (30) and / or the battery housing (20) after compression, the battery housing (20) cannot be perfectly sealed. Accordingly, the possibility of the electrolyte leaking to the outside when the electrolyte is injected becomes very high.

[0052] More specifically, referring to FIGS. 4 to 6, in the conventional O-ring (100), the first part (110) has a shape with extended legs rather than a cylindrical shape. At this time, when the O-ring (100) is pressed in the up and down direction, the leg portion of the first part (110) is lifted upward, and the first part (110) comes into line contact with the current collector (30) and / or the battery housing (20). Consequently, the battery housing (20) cannot be perfectly sealed, and the possibility of the electrolyte leaking to the outside when the electrolyte is injected becomes very high. That is, the structure of the conventional O-ring (100) is such that a downward force is applied by the hopper (H), causing the bottom surface to come into contact with the upper surface of the beading portion (21) of the battery housing (20), and subsequently, the side of the O-ring (100) is lifted to seal the side surface of the battery housing (20). According to this structure, the O-ring (100) and the battery housing (20) maintain sealing through line contact, so the sealing effect is not sufficient.

[0053] Accordingly, the inventors have derived an O-ring (100) structure for improving sealing performance by expanding the contact area between the battery housing (20) and the O-ring (100) compared to a conventional O-ring (100). That is, the present invention relates to an O-ring (100) structure capable of preventing electrolyte leakage when the electrolyte is injected into a cylindrical battery cell. This will be explained in detail below through FIGS. 7 to 10.

[0055] FIG. 7 is a drawing for explaining an O-ring (100) according to one embodiment of the present invention. FIG. 8 is a drawing for explaining the state of the O-ring (100) of FIG. 7 before compression, and FIG. 9 is an enlarged view of a part of FIG. 8. FIG. 10 is a drawing for explaining the state of the O-ring (100) of FIG. 7 after compression.

[0056] Referring to FIG. 7, the O-ring (100) comprises a first part (110) and a second part (120). The O-ring (100) may further comprise a pressure surface (130). More specifically, the O-ring (100) may comprise a first part (110) that is seated on a beading portion (21) into which a battery housing (20) is inserted; and a second part (120) that is provided above the first part (110) and configured to cover the upper surface (25) of the battery housing (20). The first part (110) and the second part (120) may be formed integrally. The O-ring (100) may be applied to the state after the beading portion (21) is formed on the battery cell and before the crimping process is performed. That is, the O-ring (100) can be used when the upper part is not closed by the housing cover after the beading portion (21) is formed on the battery cell. That is, the O-ring (100) can be applied when the upper part of the battery cell is open.

[0057] The first part (110) may be configured, for example, in a roughly cylindrical shape. That is, since the first part (110) is seated on the beading portion (21) of the cylindrical battery cell, it is preferable that it have a shape roughly similar to the battery housing (20). Accordingly, it is preferable that the first part (110) have a roughly cylindrical shape.

[0058] According to this structure, surface contact between the O-ring (100) and the battery housing (20) is possible, thereby expanding the contact area. That is, according to the above structure of the present invention, when the O-ring (100) is compressed in the total direction, most of the area where the battery housing (20) and the O-ring (100) come into contact is in the form of surface contact, so that the electrolyte can be effectively prevented from leaking to the outside of the battery housing (20) when the electrolyte is injected.

[0060] Meanwhile, the second part (120) is provided on the upper part of the first part (110) and must be able to cover the upper surface (25) of the battery housing (20), so it may likewise be configured in a roughly cylindrical shape. More specifically, the second part (120) may have a shape that extends further in the horizontal direction from the first part (110). Accordingly, the second part (120) may be configured in a cylindrical shape with a larger radius than the first part (110). However, the shape of the second part (120) is not limited to a cylindrical shape, and any shape that protrudes further outward in the radial direction than the first part (110) to cover the upper surface (25) of the battery housing (20) is included within the scope of the present invention.

[0061] Preferably, the outer surface of the first part (110) may be formed in a cylindrical shape having a radius of approximately constant. In this case, the distance from the center of the first part (110) to the outer surface of the first part (110) is preferably smaller than or equal to the inner diameter of the battery housing (20). If the distance from the center of the first part (110) to the outer surface of the first part (110) is larger than the inner diameter of the battery housing (20), the first part (110) cannot be smoothly inserted into the inner side of the battery housing (20).

[0063] In one aspect of the present invention, the O-ring (100) may be configured to have elasticity. That is, the O-ring (100) may be configured so that its shape is deformed by external pressure. For example, the O-ring (100) may include at least one of NBR, VMQ, FKM, and FPM.

[0064] According to this configuration, when the O-ring (100) is inserted into the battery housing (20) and then compressed in one direction, the shape of the O-ring (100) is deformed, thereby sealing the battery housing (20). For example, if the O-ring (100) is compressed in the vertical direction, the horizontal thickness of the O-ring (100) can be increased. Accordingly, the horizontal gap existing between the O-ring (100) and the battery housing (20) can be filled by the deformation of the O-ring (100). In this way, due to the elastic characteristics of the O-ring (100), the sealing performance can be improved, thereby effectively preventing leakage of the electrolyte. Additionally, the internal pressure of the battery housing (20) can be maintained or smoothly controlled.

[0066] In another aspect of the present invention, the O-ring (100) may include a liquid injection hole (H3) that penetrates vertically in the center. Through the liquid injection hole (H3), the electrolyte may be injected into the battery housing (20).

[0067] According to the above structure, when the O-ring (100) is inserted into the battery housing (20) and then compressed in the vertical direction, the O-ring (100) and the inner surface of the battery housing (20) come into surface contact, thereby improving the sealing performance. Therefore, leakage of the electrolyte can be prevented when the electrolyte is injected. In addition, since the sealing performance between the O-ring (100) and the battery housing (20) is secured, the internal pressure of the battery housing (20) can be stably controlled.

[0069] In one aspect of the present invention, the O-ring (100) may have a groove (G) into which a hopper (H) capable of pressing the O-ring (100) can be fitted. That is, the O-ring (100) and the hopper (H) may be configured to be detachable.

[0070] Referring again to FIG. 7, a hopper (H) capable of pressing the O-ring (100) may be inserted inside the O-ring (100). The hopper (H) may be configured to press at least a portion of the O-ring (100). For example, referring to FIG. 7, the hopper (H) may be inserted into a groove (G) provided inside the O-ring (100), and the hopper (H) may be configured to press the pressing surface (130) of the O-ring (100). Accordingly, the O-ring (100) may be pressed in the winding axis direction of the electrode assembly (10). More specifically, the O-ring (100) may be pressed downward.

[0071] According to the above structure, the replacement of the O-ring (100) is facilitated. That is, damage may frequently occur to the surface of the O-ring (100) that comes into contact with the battery housing (20) due to repeated compression. At this time, according to the structure of the present invention as described above, by providing a groove (G) in at least a portion of the O-ring (100) to make the hopper (H) detachable, the replacement of only the O-ring (100) can be facilitated. Furthermore, when the hopper (H) is mounted inside the O-ring (100) by providing a groove (G) inside the O-ring (100), the hopper (H) occupies most of the internal space of the O-ring (100), thereby reducing the cost of materials required to manufacture the O-ring (100).

[0073] In another aspect of the present invention, the outer surface of the first part (110) may be configured to be spaced apart from the inner surface of the battery housing (20) by a predetermined distance.

[0074] For example, referring to FIG. 8, the outer surface of the first part (110) may be spaced apart from the inner surface of the battery housing (20) by a predetermined distance. More specifically, the outer surface of the first part (110) and the inner surface of the battery housing (20) may be spaced apart by a predetermined distance in the radial direction. For example, when the outer diameter of the battery housing (20) is about 46 mm and the inner diameter is about 45 mm, the outer surface of the first part (110) may be configured to be spaced apart from the inner surface of the battery housing (20) by about 0.2 to 0.8 mm. If the distance (D1) between the outer surface of the first part (110) and the inner surface of the battery housing (20) is less than about 0.2 mm, the process of inserting the O-ring (100) into the battery housing (20) may not be smooth. In another aspect, if the distance (D1) between the outer surface of the first part (110) and the inner surface of the battery housing (20) is greater than about 0.8 mm, surface contact for sealing may not be achieved when the O-ring (100) is compressed. Therefore, it is preferable that the outer surface of the first part (110) be configured to be spaced about 0.2 to 0.8 mm apart from the inner surface of the battery housing (20), and it is even more preferable that it be spaced about 0.5 to 0.7 mm apart. For example, as an example, the outer surface of the first part (110) may be configured to be spaced about 0.6 mm apart from the inner surface of the battery housing (20). Meanwhile, the present invention is not limited to such absolute values, and relative values ​​converted in relation to the size of the battery housing (20) are included within the scope of the present invention.

[0075] According to the above structure, the O-ring (100) can be smoothly inserted into the battery housing (20). In addition, when the O-ring (100) is compressed in one direction after being inserted, the shape of the O-ring (100) is deformed and comes into contact with the inner surface of the battery housing (20), thereby effectively sealing the battery housing (20).

[0077] In another aspect of the present invention, the lower surface of the second part (120) may be configured to be spaced apart from the upper surface (25) of the battery housing (20) by a predetermined distance.

[0078] For example, referring to FIG. 8, the lower surface of the second part (120) may be spaced apart from the upper surface (25) of the battery housing (20) by a predetermined distance. More specifically, the lower surface of the second part (120) and the upper surface (25) of the battery housing (20) may be spaced apart by a predetermined distance in the radial direction. For example, when the outer diameter of the battery housing (20) is about 46 mm and the inner diameter is about 45 mm, the lower surface of the second part (120) may be configured to be spaced apart from the upper surface (25) of the battery housing (20) by about 0.2 to 0.8 mm. If the distance (D2) between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20) is less than about 0.2 mm, the likelihood of damage to the lower surface of the second part (120) increases when contact between the upper surface (25) of the battery housing (20) and the lower surface of the second part (120) is repeated due to the repeated compression of the O-ring (100). On the other hand, if the distance (D2) between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20) is greater than about 0.8 mm, surface contact for sealing may not occur during the compression of the O-ring (100). Therefore, it is preferable that the lower surface of the second part (120) be configured to be spaced about 0.2 to 0.8 mm apart from the upper surface (25) of the battery housing (20), and it is even more preferable that it be spaced about 0.5 to 0.7 mm apart. For example, as an example, the lower surface of the second part (120) may be configured to be spaced about 0.6 mm apart from the upper surface (25) of the battery housing (20). Meanwhile, the present invention is not limited to such absolute values, and relative values ​​converted in relation to the size of the battery housing (20) are included within the scope of the present invention.

[0079] According to the above structure, when the O-ring (100) is compressed, the second part (120) comes into contact with the upper surface (25) of the battery housing (20) as the shape of the O-ring (100) is deformed, so the battery housing (20) can be additionally sealed.

[0081] In another aspect of the present invention, the outer diameter of the second part (120) may match the outer diameter of the battery housing (20).

[0082] For example, referring to FIG. 9, the outer surface of the battery housing (20) and the outer surface of the second part (120) can be configured to have nearly similar diameters. With such a configuration, the outer diameters of the battery housing (20) and the O-ring (100) are similar, so even if contact between the upper surface (25) of the battery housing (20) and the lower surface of the second part (120) is repeated, the end of the O-ring (100) is deformed, thereby reducing the possibility of damage to the lower surface of the second part (120).

[0083] For example, in a conventional O-ring (100), since the outer diameter of the second part (120) is larger than the outer diameter of the battery housing (20), if contact between the upper surface (25) of the battery housing (20) and the lower surface of the second part (120) is repeated, there is a high possibility that the point where the second part (120) contacts the upper surface (25) of the battery housing (20) will be gouged inward and damaged. However, according to the structure of the present invention, since the outer diameters of the battery housing (20) and the O-ring (100) are similar, the phenomenon of gouging inward can be prevented even if the point where the second part (120) contacts the upper surface (25) of the battery housing (20) is deformed upward.

[0085] In one aspect of the present invention, the O-ring (100) may include a pressure surface (130) provided in at least a portion of the O-ring (100) and configured to be pressed downward by the hopper (H). For example, the O-ring (100) may include a pressure surface (130) provided inside or outside the O-ring (100) and configured to be pressed downward by the hopper (H).

[0086] For example, referring to FIG. 7, the pressure surface (130) may be configured to press the O-ring (100) downward. For example, among the surfaces forming the groove (G) provided inside the O-ring (100), the upward-facing surface may correspond to the pressure surface (130). That is, among the surfaces forming the groove (G) provided inside the O-ring (100), the upward-facing surface comes into contact with the lower surface of the hopper (H), so the surface pressed by the lower surface of the hopper (H) may correspond to the pressure surface (130) of the O-ring (100). Alternatively, the upper surface of the O-ring (100) shown in FIG. 7 may also correspond to the pressure surface (130). For example, the hopper (H) may be fitted into the groove (G) provided inside the O-ring (100), but may also be shaped to press the upper surface of the O-ring (100). That is, in the O-ring (100) shown in the embodiment of FIG. 7, the surface facing upward among the surfaces forming the groove (G) provided inside the O-ring (100) and the upper surface of the O-ring (100) may correspond to the pressing surface (130).

[0087] In another aspect of the present invention, when the pressure surface (130) is pressed downward, the first part (110) may be configured to be compressed in the vertical direction and to increase in width in the radial direction. That is, when pressure is applied from the outside of the battery housing (20) toward the beading portion (21) of the battery housing (20), the first part (110) may be configured to come into contact with the inner surface of the battery housing (20).

[0088] At this time, in order to reliably prevent leakage, it is desirable that the contact pressure between the outer surface of the first part (110) and the inner surface of the battery housing (20) be greater than the electrolyte injection pressure. For example, when the electrolyte injection pressure is about 8 bar, the contact pressure between the outer surface of the first part (110) and the inner surface of the battery housing (20) must be greater than about 8 bar to maintain the seal.

[0090] In another aspect of the present invention, when the pressing surface (130) is pressed downward, the second part (120) may be configured to move downward and come into contact with the upper surface (25) of the battery housing (20). That is, when pressure is applied from the outside of the battery housing (20) in a direction toward the beading portion (21) of the battery housing (20), the second part (120) may be configured to come into contact with the upper surface (25) of the battery housing (20).

[0091] According to the above configuration, a primary sealing is possible between the outer surface of the first part (110) and the inner surface of the battery housing (20), and a secondary sealing is possible between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20).

[0092] At this time, in order to reliably prevent leakage, it is preferable that the contact pressure between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20) be greater than the electrolyte injection pressure. For example, when the electrolyte injection pressure is about 8 bar, if the contact pressure between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20) is greater than about 8 bar, a secondary sealing effect can be achieved.

[0093] That is, according to the above configuration, when pressure is applied from the outside of the battery housing (20) toward the beading portion (21) of the battery housing (20), the O-ring (100) can be configured to block the outside and inside of the battery housing (20). Accordingly, the sealing performance of the battery housing (20) can be improved, and leakage of the electrolyte can be effectively prevented. In addition, the internal pressure of the battery housing (20) can be maintained or smoothly controlled.

[0095] FIG. 11 is a drawing for illustrating an O-ring (100) according to another embodiment of the present invention.

[0096] Since the O-ring (100) according to the present embodiment is similar to the O-ring (100) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0097] Referring to FIG. 11, the second part (120) of the O-ring (100) may further include an extension cover portion (121). The extension cover portion (121) may be configured to extend downward from the second part (120) and cover the outer surface of the upper surface (25) of the battery housing (20). The extension cover portion (121) may be configured to contact the outer surface of the battery housing (20). The end surface of the extension cover portion (121) may be configured to be parallel to the horizontal direction.

[0098] According to the above configuration, a first sealing is achieved by sealing between the outer surface of the first part (110) and the inner surface of the battery housing (20), and a second sealing is achieved between the lower surface of the second part (120) and the upper surface (25) of the battery housing (20). Furthermore, a third sealing is achieved between the inner surface of the extension cover part (121) and the outer surface of the battery housing (20). In other words, additional sealing force can be secured. At this time, it is preferable that the contact pressure between the inner surface of the extension cover part (121) and the outer surface of the battery housing (20) be greater than the injection pressure of the electrolyte.

[0100] FIG. 12 is a drawing for illustrating an O-ring (100) according to another embodiment of the present invention.

[0101] Since the O-ring (100) according to the present embodiment is similar to the O-ring (100) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0102] Referring to FIG. 12, the O-ring (100) may include a lower surface (111). In this case, the lower surface (111) may be the lower surface (111) of the first part (110). That is, among the surfaces constituting the first part (110), the surface located at the bottom may correspond to the lower surface (111) of the O-ring (100). Referring again to FIG. 7, the lower surface (111) of the O-ring (100) is configured to contact the beading portion (21) and / or the current collector (30). More specifically, the lower surface (111) of the O-ring (100) may be configured to contact the upper surface of the beading portion (21) and / or the contact portion (33a) of the housing coupling portion (33) of the current collector (30). That is, the structure is such that the contact portion (33a) of the current collector (30) is seated on the upper surface of the beading portion (21). At this time, since the current collector (30) has a predetermined thickness, when the O-ring (100) is seated on the beading portion (21) and / or the current collector (30), a fine gap may exist between the O-ring (100) and the upper surface of the beading portion (21). At this time, the size of the fine gap may be the same as the thickness of the current collector (30). That is, a fine gap may exist between the O-ring (100) and the beading portion (21), and there is a possibility that the electrolyte may leak through this gap. Meanwhile, since the O-ring (100) has elasticity, the size of the gap may be reduced when the O-ring (100) is pressed in the up and down direction. However, since there is a possibility that the gap may not be completely eliminated, it is preferable that the lower surface of the O-ring (100) be provided with at least one lower groove (113) so as to match the shape of the contact portion (33a) of the current collector (30).

[0103] More specifically, referring to FIG. 12, the thickness of the first part (110) may alternately increase and decrease along the circumferential direction. For example, the lower surface of the first part (110) may be provided with grooves (G) at predetermined intervals along the circumferential direction. Preferably, the grooves (G) may be configured to match the shape of the current collector (30). That is, the lower surface of the first part (110) is provided with at least one lower groove (113) that is cut upward. For example, in one embodiment, if the contact portion (33a) of the current collector (30) is provided with four, the lower grooves (113) provided on the lower surface of the O-ring (100) may also be provided with four. At this time, it is preferable that the shape of the contact portion (33a) and the shape of the lower groove (113) of the O-ring (100) are shapes that match each other. For example, the contact portion (33a) of the current collector (30) may have an arc shape that extends circumferentially along the beading portion (21) of the battery housing (20) for at least a portion. Thus, the circumferential extension length of the contact portion (33a) may be formed to be longer than the width of the connecting portion (33b). In another embodiment, the contact portion (33a) may have an arc shape that extends in opposite directions along the circumferential direction on the beading portion (21) from the intersection point of the connecting portion (33b) and the contact portion (33a). However, the number or shape of the contact portion (33a) of the current collector (30) or the number or shape of the lower groove (113) of the O-ring (100) is not limited to this embodiment. That is, if the shape of the contact portion (33a) and the shape of the lower groove (113) of the O-ring (100) are mutually matched, it may be considered to be included within the scope of the present invention.

[0104] According to the above configuration, a gap can be prevented from forming between the O-ring (100) and the beading portion (21). That is, the O-ring (100) can seal the battery housing (20) more effectively. Accordingly, the possibility of leakage of the electrolyte can be further reduced. In addition, an environment can be created to maintain a constant internal pressure of the battery housing (20).

[0106] FIG. 13 is a drawing for illustrating an O-ring (100) according to another embodiment of the present invention.

[0107] Since the O-ring (100) according to the present embodiment is similar to the O-ring (100) of the preceding embodiment, redundant descriptions of configurations that are substantially identical or similar to the preceding embodiment are omitted, and the following description focuses on the differences from the preceding embodiment.

[0108] Referring to FIG. 13, the O-ring (100) does not include a groove (G) inside. The O-ring (100) may include a groove (G) on the outside. For example, the center of the O-ring (100) shown in FIG. 13 is provided with only a liquid injection hole (H3) for liquid injection, and a groove (G) for inserting a hopper (H) is not provided. Instead, a groove (G) for inserting a hopper (H) may be provided on the outer surface of the O-ring (100). In this way, a groove (G) may be provided on the outside or inside of the O-ring (100), and depending on the shape of the groove (G), the hopper (H) may also be attached to the outside or inside of the O-ring (100). That is, the location where the groove (G) is provided is not limited, and a hopper (H) can be mounted in the groove (G), and if the hopper (H) is in a form capable of compressing the O-ring (100), it is considered to be included within the scope of the present invention.

[0110] Although the present invention has been described above with reference to limited embodiments and drawings, the present invention is not limited thereto, and it is obvious that various modifications and variations are possible within the scope of the technical spirit of the present invention and the equivalent scope of the claims described below by those skilled in the art to which the present invention belongs. Explanation of the symbols

[0112] 1 battery cell 10 electrode assemblies 11 1st Department of Indefinite Expenses 12 2nd Department of Indefinite Service H1 winding center hole 20 battery housings 20a External surface of the closure 21 Bidding Department 22 Climbing section 25 Top surface 30 whole house H2 Entire House Hall 31 Support Unit 32 Tab Joint 33 Housing joint 33a Contact part 33b Connection 50 terminals 60 The entire second house H Hopper 100 O-rings 110 Part 1 111 bottom surface 113 Lower groove 120 Part 2 121 Extension cover part 130 pressurized surface G Groove H3 Central Hall

Claims

Claim 1 An O-ring comprising: a first part that is seated on a beading portion into which a battery housing is inserted; and a second part provided above the first part and configured to cover the upper surface of the battery housing, wherein the outer surface of the first part is configured in a cylindrical shape having a certain radius. Claim 2 delete Claim 3 In claim 1, the O-ring is characterized by having elasticity. Claim 4 In claim 1, the O-ring is characterized by comprising at least one of NBR, VMQ, FKM, and FPM. Claim 5 The O-ring according to claim 1, characterized in that the O-ring includes a liquid injection hole penetrating in the vertical direction in the center. Claim 6 In claim 1, the O-ring is characterized by having a groove into which a hopper capable of pressing the O-ring can be fitted. Claim 7 An O-ring according to claim 1, characterized in that the outer surface of the first part is configured to be spaced apart from the inner surface of the battery housing by a predetermined distance. Claim 8 An O-ring according to claim 1, characterized in that the outer surface of the first part is configured to be spaced apart from the inner surface of the battery housing by 0.2 to 0.8 mm. Claim 9 An O-ring according to claim 1, characterized in that the lower surface of the second part is configured to be spaced apart from the upper surface of the battery housing by a predetermined distance. Claim 10 In claim 1, the O-ring is characterized by including a pressure surface provided on the inside or outside of the O-ring and configured to be pressed downward by a hopper. Claim 11 An O-ring according to claim 10, characterized in that when the pressure surface is pressed downward, the first part is compressed in the vertical direction and its width increases in the radial direction. Claim 12 An O-ring according to claim 10, characterized in that when the pressure surface is pressed downward, the second part is configured to move downward and come into contact with the upper surface of the battery housing. Claim 13 An O-ring according to claim 1, characterized in that when pressure is applied from the outside of the battery housing toward the beading portion of the battery housing, the O-ring is configured to block the outside and inside of the battery housing. Claim 14 An O-ring according to claim 1, characterized in that the thickness of the first part alternately increases and decreases along the circumferential direction.

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