Sealing assembly and battery cell

Abstract

This application relates to a sealing assembly and a battery cell. The sealing assembly includes: a base, comprising a base body, a protrusion, and a first through hole; the base body has a first groove; the protrusion is located within the first groove and protrudes from the bottom wall of the first groove; the first through hole sequentially passes through the protrusion and the base body; a sealing element, comprising a first sealing portion, a second sealing portion, and a third sealing portion sequentially connected; the first sealing portion is located within the first groove and sleeved outside the protrusion; the second sealing portion is located within the first sealing portion and defines a second groove with the first sealing portion; the second groove is disposed away from the first through hole; the second sealing portion covers the first through hole; and the third sealing portion is at least partially located within the first through hole; and a fixing unit, at least partially detachably disposed within the second groove, and used to jointly compress the sealing element with the base. The sealing assembly and battery cell provided by this application can perform lithium replenishment, electrolyte replenishment, and pressure reduction on the battery cell.

Description

Technical Field

[0001] This application relates to the field of battery technology, specifically to a sealing assembly and a battery cell. Background Technology

[0002] Taking batteries as an example, during the charging and discharging process of a battery cell, the electrolyte and lithium (such as lithium-ion battery cells) in the battery cell are all lost to a certain extent. In addition, gas is also generated, which can lead to the risk of the battery cell bulging.

[0003] To address the above issues, after a period of battery use, it is necessary to replenish the electrolyte and lithium appropriately, and to periodically vent and depressurize the individual battery cells to extend the battery's lifespan.

[0004] Therefore, designing a method to replenish lithium, replenish electrolyte, and reduce pressure in battery cells has become an urgent problem to be solved. Summary of the Invention

[0005] Therefore, it is necessary to provide a sealed assembly and battery cell capable of replenishing lithium, replenishing electrolyte, and reducing pressure in a single battery cell to address the aforementioned problems.

[0006] In a first aspect, this application provides a sealing assembly, the sealing assembly comprising:

[0007] The base includes a base body, a protrusion and a first through hole. The base body has a first groove. The protrusion is located in the first groove and protrudes from the bottom wall of the first groove. The first through hole passes through the protrusion and the base body in sequence.

[0008] A sealing element includes a first sealing part, a second sealing part, and a third sealing part connected in sequence. The first sealing part is located in the first groove and is sleeved on the outside of the protrusion. The second sealing part is located in the first sealing part and defines a second groove with the first sealing part. The second groove is disposed away from the first through hole. The second sealing part covers the first through hole. The third sealing part is at least partially located in the first through hole.

[0009] A fixing unit, at least partially detachably disposed within the second groove, is used to press the seal together with the base.

[0010] In some embodiments, the sidewall of the first groove and the peripheral surface of the first sealing part facing the sidewall are both inclined surfaces that are inclined relative to the bottom wall of the first groove. In the through direction of the first through hole, the cross-sectional area of ​​the sidewall of the first groove and the cross-sectional area of ​​the peripheral surface of the first sealing part gradually increase.

[0011] In some embodiments, the angle of inclination of the side wall surface of the first groove relative to the bottom wall surface of the first groove is A, and the angle of inclination of the side peripheral surface of the first sealing part relative to the bottom wall surface of the first groove is B.

[0012] 80°≤A≤90°; and / or, 80°≤B≤90°; and / or, A=B.

[0013] In some embodiments, the fixing unit includes an expansion member and a fixing member. The expansion member is at least partially disposed in the second groove and has a through-hole. The fixing member is at least partially disposed in the second through-hole and is used to compress the expansion member and the second sealing portion.

[0014] In some embodiments, the second through hole includes a first sub-hole, a second sub-hole, and a third sub-hole, wherein the first sub-hole, the second sub-hole, and the third sub-hole gradually approach the first through hole;

[0015] The cross-sectional area of ​​the first sub-hole is greater than the cross-sectional area of ​​the second sub-hole, which is greater than the cross-sectional area of ​​the third sub-hole.

[0016] In some embodiments, the expansion member includes a first expansion portion and a plurality of second expansion portions. The first expansion portion is annular and surrounds the first sub-hole. The second expansion portions are connected to the first expansion portion, and all the second expansion portions are spaced apart and surround the second sub-hole and the third sub-hole.

[0017] In some embodiments, the second expansion portion has a connected first wall surface and a second wall surface, the first wall surface of all the second expansion portions surrounds to form the second sub-hole, and the second wall surface of all the second expansion portions surrounds to form the third sub-hole;

[0018] The first wall surface is an inclined surface that is inclined relative to the central axis of the second through hole, and in the direction from the first sub-hole to the third sub-hole, the distance between the first wall surface and the central axis of the second through hole gradually decreases, while the distance between the second wall surface and the central axis of the second through hole is equal.

[0019] In some embodiments, the third sealing portion includes a first segment and a second segment, the first segment being located inside the first through hole and the second segment being located outside the first through hole, and the cross-sectional area of ​​the second segment being larger than the cross-sectional area of ​​the first segment.

[0020] In some embodiments, the base includes a first portion and a second portion connected together;

[0021] The first part includes a first main body and a first protrusion. The first protrusion is disposed on one side of the first main body. The first part has a third through hole, which passes through the first main body and the first protrusion in sequence.

[0022] The second part includes a second main body and a second protrusion. The second main body, together with the first main body and the first protrusion, forms the seat body. The second main body has a first surface facing the third through hole. The first surface and the hole wall of the third through hole define the first groove. The second protrusion is disposed on the first surface and forms the protrusion. The first through hole passes through the second protrusion and the second main body.

[0023] In some embodiments, the wall surface of the third through hole is an inclined surface that is inclined relative to the central axis of the first through hole, and the cross-sectional area of ​​the third through hole gradually increases in the through direction of the first through hole.

[0024] And / or, the first sealing portion extends to the first surface.

[0025] In some embodiments, the first main body portion is recessed in a direction away from the second main body portion to form a first recess, and the first convex portion is located in the first recess; and

[0026] The second main body portion is recessed in a direction away from the first main body portion to form a second recess, and the second convex portion is at least partially located in the second recess.

[0027] In some embodiments, the first protrusion extends at least partially into the second recess.

[0028] In some embodiments, the first body portion further includes a first straight portion circumferentially disposed around the first recess, and the second body portion further includes a second straight portion circumferentially disposed around the second recess, wherein the sealing assembly satisfies at least one of (1) to (6):

[0029] (1) The first straight portion and the second straight portion are stacked and connected;

[0030] (2) The surface of the first straight portion facing the second straight portion has the third groove, and the third groove extends from the inside to the outside through the side periphery of the first straight portion;

[0031] (3) The thickness of the first straight section is H1, 1mm≤H1≤5mm;

[0032] (4) The second straight portion has a second surface disposed toward the first straight portion, and the distance between the second surface and the first surface is H2, 2mm≤H2≤6mm;

[0033] (5) The distance between the two surfaces of the second convex part and the second concave part that are far apart from each other is H3, 1.5mm≤H3≤3mm;

[0034] (6) The second straight portion has a third surface away from the first straight portion, and the second recess has a fourth surface disposed opposite to the first surface. The distance between the third surface and the fourth surface is H4, 3mm≤H4≤6mm.

[0035] In some embodiments, the surfaces of the seal, the fixing unit, and the seat body that are away from the first through hole are flush; and / or, the diameter of the opening of the first groove away from the first through hole is D, 5mm≤D≤20mm.

[0036] Secondly, this application also provides a battery cell, which includes a housing, an electrode assembly, and a sealing assembly as described in any of the above embodiments, wherein the sealing assembly is mounted on the housing and the electrode assembly is disposed inside the housing.

[0037] Compared with the prior art, this application has the following beneficial effects:

[0038] The aforementioned sealing components and battery cells, base, seals and fixing units work together. By disassembling the fixing unit and seals, operations such as replenishing electrolyte, replenishing lithium, venting and depressurizing can be repeatedly performed through the first through hole to improve the safety of the battery cells and extend the battery's service life. By installing and removing the fixing unit and seals, the first through hole and the first groove can be sealed, and a better sealing effect can be achieved to effectively isolate the inside and outside of the battery cells. Attached Figure Description

[0039] Figure 1 This is a schematic diagram of the sealing assembly in one embodiment of this application;

[0040] Figure 2 for Figure 1 An exploded view of the sealing assembly shown;

[0041] Figure 3 for Figure 1 A top view of the sealing assembly shown;

[0042] Figure 4 for Figure 3 The sealing assembly shown is a cross-sectional view along the MM direction;

[0043] Figure 5 for Figure 4 An exploded view of the sealing assembly shown;

[0044] Figure 6 for Figure 1 The diagram shows the structure of the seal in the sealing assembly.

[0045] Figure 7 for Figure 1 The diagram shows the structure of the expansion element in the sealing assembly.

[0046] Figure 8 for Figure 1 The diagram shows the structure of the first part of the sealing assembly.

[0047] Figure 9 for Figure 1 The diagram shows the structure of the second part of the sealing assembly.

[0048] Icon labels:

[0049] 100. Sealing components;

[0050] 10. Base; 20. Seal; 30. Fixing unit;

[0051] 11. Seat body; 111. First groove; 1111. Side wall surface; 12. Protrusion; 13. First part; 131. First main body part; 1311. First recess; 1312. First straight part; 13121. Third groove; 132. First protrusion; 133. Third through hole; 14. Second part; 141. Second main body part; 1411. Second recess; 14111. First surface; 14112. Fourth surface; 1412. Second straight part; 14121. Second surface; 14122. Third surface; 15. First through hole;

[0052] 21. First sealing part; 211. Side peripheral surface; 22. Second sealing part; 23. Third sealing part; 231. First section; 232. Second section; 24. Second groove;

[0053] 31. Expansion member; 311. Second through hole; 3111. First sub-hole; 3112. Second sub-hole; 3113. Third sub-hole; 312. First expansion part; 313. Second expansion part; 3131. First wall surface; 3132. Second wall surface; 32. Fixing member; 321. Fourth groove. Detailed Implementation

[0054] To make the above-mentioned objectives, features, and advantages of this application more apparent and understandable, the specific embodiments of this application are described in detail below with reference to the accompanying drawings. Many specific details are set forth in the following description to provide a thorough understanding of this application. However, this application can be implemented in many other ways different from those described herein, and those skilled in the art can make similar modifications without departing from the spirit of this application. Therefore, this application is not limited to the specific embodiments disclosed below.

[0055] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0056] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0057] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "joining," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0058] In this application, unless otherwise expressly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "on top of," and "over" the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0059] It should be noted that when an element is referred to as being "fixed to" or "set on" another element, it can be directly on the other element or there may be an intervening element. When an element is considered to be "connected to" another element, it can be directly connected to the other element or there may be an intervening element. The terms "vertical," "horizontal," "upper," "lower," "left," "right," and similar expressions used herein are for illustrative purposes only and do not represent the only possible implementation.

[0060] Taking batteries as an example, during the charging and discharging process of a battery cell, the electrolyte and lithium (such as lithium-ion battery cells) in the battery cell are all lost to a certain extent. In addition, gas is also generated, which can lead to the risk of the battery cell bulging.

[0061] To address the aforementioned issues, after a period of use, it is necessary to replenish the electrolyte and lithium appropriately, and to periodically vent and depressurize the battery cells to extend their lifespan.

[0062] Please see Figures 1 to 5 Based on this, the applicant, after in-depth research, designed a sealing assembly 100. The sealing assembly 100 can be used, but is not limited to, for operations such as lithium replenishment, electrolyte replenishment (hereinafter referred to as electrolyte replenishment), and pressure reduction. The sealing assembly 100 includes a base 10, a sealing element 20, and a fixing unit 30. The base 10 includes a base body 11, a protrusion 12, and a first through hole 15. The base body 11 has a first groove 111. The protrusion 12 is located in the first groove 111 and protrudes from the bottom wall surface of the first groove 111. The first through hole 15 passes through the protrusion 12 and the base body 11 in sequence. The sealing element 20 includes a first sealing portion 21, a second sealing portion 22, and a third sealing portion 23 connected in sequence. The first sealing portion 21 is located within the first groove 111 and is fitted over the protrusion 12. The second sealing portion 22 is located within the first sealing portion 21 and defines a second groove 24 with the first sealing portion 21. The second groove 24 is disposed away from the first through hole 15, and the second sealing portion 22 covers the first through hole 15. The third sealing portion 23 is at least partially located within the first through hole 15. The fixing unit 30 is at least partially detachably disposed within the second groove 24 and is used to jointly press the sealing element 20 with the seat body 11.

[0063] like Figure 1 , Figure 4 and Figure 5As shown, the base 10 mainly serves for installation and support. Optionally, the base 10 may be, but is not limited to, a flat plate, an irregular shape, etc. The base body 11 of the base 10 has a first groove 111. The protrusion 12 of the base 10 protrudes from the bottom wall of the first groove 111. The first through hole 15 passes through the protrusion 12 and the base body 11. The first through hole 15 may be used, but is not limited to, for injecting electrolyte (hereinafter referred to as electrolyte injection), replenishing electrolyte, replenishing lithium, venting and depressurizing, etc.

[0064] Optionally, the seal 20 may be made of elastic materials such as rubber or silicone.

[0065] like Figure 4 and Figure 5 As shown, the first sealing portion 21 of the seal 20 is located in the first groove 111, and the side peripheral surface 211 of the first sealing portion 21 contacts the side wall surface 1111 of the first groove 111. The second sealing portion 22 of the seal 20 covers the first through hole 15 and contacts the end face of the protrusion 12 facing the second sealing portion 22. An opening of the first through hole 15 is located on the end face. The second sealing portion 22 and the first sealing portion 21 define a second groove 24. The third sealing portion 23 of the seal 20 is at least partially located in the first through hole 15 and contacts and seals the hole wall surface of the first through hole 15.

[0066] like Figures 1 to 5 As shown, the fixing unit 30 is at least partially detachably disposed in the second groove 24 in a manner that may be, but is not limited to, an interference fit between the fixing unit 30 and the second groove 24.

[0067] The fixing unit 30 is at least partially disposed in the second groove 24 and, together with the base 10, presses against the sealing member 20 to achieve a seal. Specifically, the fixing unit 30 and the base body 11 are arranged radially parallel to the first through hole 15 (in one embodiment, the first through hole 15 is radially as shown in the image). Figure 4 The first sealing part 21 is pressed together in the direction indicated by the middle arrow X, so that the side peripheral surface 211 of the first sealing part 21 can form a seal with the side wall surface 1111 of the first groove 111. The fixing unit 30 and the protrusion 12 are aligned along the through direction of the first through hole 15 (as shown by the middle arrow X). Figure 4 (As indicated by the middle arrow Z) By compressing the second sealing part 22, the second sealing part 22 can form a seal with the end face of the protrusion 12 facing the second sealing part 22. Combined with the seal between the third sealing part 23 and the first through hole 15, the sealing member 20 and the base 10 can achieve multi-position and multiple seals, and can form a relatively tortuous, complex and long sealing path (the sealing path is as follows). Figure 4 As shown in a→b→c→d→e, the sealing effect between the sealant 20 and the base 10 is improved, thereby preventing electrolyte leakage to the outside or preventing external moisture and other substances from entering the battery cell.

[0068] After the fixing unit 30 is removed from the second groove 24, the sealing element 20 can be easily removed from the base 10, so that operations such as liquid injection, lithium replenishment, liquid replenishment and degassing can be performed on the battery cell.

[0069] Please see Figure 1 and Figure 4 Therefore, in this application, the base 10, the seal 20 and the fixing unit 30 cooperate to repeatedly perform operations such as replenishing liquid, replenishing lithium, venting and depressurizing by disassembling the fixing unit 30 and the seal 20 through the first through hole 15, thereby improving the safety of the battery cell and extending the battery's service life. By installing and removing the fixing unit 30 and the seal 20, the first through hole 15 and the first groove 111 can be sealed, and a better sealing effect can be achieved to achieve the purpose of effectively isolating the inside and outside of the battery cell.

[0070] Please see Figure 4 and Figure 5 In some embodiments, the side wall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21 facing the side wall surface 1111 are both inclined surfaces that are inclined relative to the bottom wall surface of the first groove 111. In the through direction of the first through hole 15, the cross-sectional area of ​​the side wall surface 1111 of the first groove 111 and the cross-sectional area of ​​the side peripheral surface 211 of the first sealing part 21 gradually increase.

[0071] like Figure 4 and Figure 5 As shown, in this design, both the first groove 111 and the first sealing part 21 form a structure that gradually widens from narrow. Therefore, in the through direction of the first through hole 15, the tightness of the fit between the first sealing part 21 and the first groove 111 gradually increases, which is equivalent to the first sealing part 21 and the first groove 111 having a self-locking effect, increasing the sealing reliability of the seal 20. In addition, gas will be generated inside the battery cell, and the gas will push the seal 20. Assuming that the force of the gas pushing the seal 20 is F, since the side circumferential surface 211 of the first sealing part 21 facing the side wall 1111 is an inclined surface, the force F set along the inclined direction of this inclined surface will be decomposed into a force F1 along the axial direction of the first through hole 15 and opposite to the through direction of the first through hole 15, and a force F1 along the radial direction of the first through hole 15 (e.g., in one embodiment, ...). Figure 4 (as indicated by X) and pointing to the central axis of the first through hole 15 (as shown by X). Figure 5The force F2 (shown in L1) is applied. It can be understood that the direction of penetration of the first through hole 15 and the direction opposite to it are two sub-directions of the axial direction of the first through hole 15. The force F1 is mainly used to push the seal 20, but since force F1 is a component force, it is smaller than force F, thus reducing the pushing effect of gas on the seal 20 and preventing the seal 20 from being pushed out. Force F2 compresses the seal 20 from the outside in, thereby ensuring that the seal 20 and the fixing unit 30 inside the seal 20 will not be pushed out. Furthermore, in the direction of penetration of the first through hole 15, the cross-sectional area of ​​the side wall surface 1111 of the first groove 111 and the cross-sectional area of ​​the side peripheral surface 211 of the first sealing part 21 gradually increase, which can also reduce the risk of the seal 20 coming out of the groove of the first groove 111, improving the reliability of the seal 20 assembly.

[0072] It is worth mentioning that, since the seal 20 is made of an elastic material, although the first sealing part 21 of the seal 20 has a structure that widens from narrow, the seal 20 can be assembled into the first groove 111 by compressing the seal 20.

[0073] Please continue reading. Figure 4 and Figure 5 Furthermore, in some embodiments, the angle of inclination of the side wall surface 1111 of the first groove 111 relative to the bottom wall surface of the first groove 111 is A, and the angle of inclination of the side peripheral surface 211 of the first sealing part 21 relative to the bottom wall surface of the first groove 111 is B; 80°≤A≤90°; and / or, 80°≤B≤90°.

[0074] Among them, A can be, but is not limited to, 80°, 83°, 87°, 90°, etc., and B can be, but is not limited to, 80°, 83°, 87°, 90°, etc.

[0075] When A and / or B are too small, the inclination of at least one of the sidewall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21 will be too large, which will increase the molding difficulty of at least one of the sidewall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21. When A and / or B are too large and exceed 90°, the first groove 111 and the first sealing part 21 cannot form a self-locking effect. Based on this, the design is 80°≤A≤90°, and / or 80°≤B≤90°, which simplifies the molding difficulty while allowing the first groove 111 and the first sealing part 21 to form a self-locking effect, thus improving the sealing effect.

[0076] Preferably, 85°≤A≤90°; and / or 85°≤B≤90°, which simplifies the molding difficulty of at least one of the first groove 111 and the first sealing part 21, while also enabling the first groove 111 and the first sealing part 21 to form a self-locking mechanism, further improving the sealing effect.

[0077] It is understood that when A=90°, the side wall surface 1111 of the first groove 111 extends along the axial direction of the first through hole 15, and when B=90°, the side peripheral surface 211 of the first sealing part 21 extends along the axial direction of the first through hole 15.

[0078] In some embodiments, A=B, so that the sidewall surface 1111 of the first groove 111 has the same inclination angle as the side peripheral surface 211 of the first sealing part 21 and can fit completely, thereby further improving the sealing effect.

[0079] In some embodiments, A≠B, and -10°≤AB<0°, or 0°<AB≤10°.

[0080] As an example, AB can be, but is not limited to, -10°, -5.5°, -3°, -1°, or AB can be, but is not limited to, 1°, 4°, 8°, 10°.

[0081] When the difference between A and B is too large, i.e., the difference between A and B is greater than 10° or less than -10°, the fit between the side wall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21 is poor, resulting in a poor sealing effect. Therefore, it is designed that -10°≤AB<0° or 0°<AB≤10° to make the difference between A and B smaller. In this way, the inclination of the side wall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21 is approximately the same, which facilitates the contact and fit between the side wall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21, thereby improving the sealing effect.

[0082] In this embodiment, the size of A and B can be set according to the requirements. If A > B, it is easier to assemble the seal 20 into the first groove 111. If A < B, the sealing effect between the seal 20 and the first groove 111 will be better.

[0083] Preferably, -5°≤AB<0°, or 0°<AB≤5°. This design facilitates further contact and fit between the sidewall surface 1111 of the first groove 111 and the side peripheral surface 211 of the first sealing part 21, greatly improving the sealing effect.

[0084] Please see Figures 1 to 5 And see also Figure 7In some embodiments, the fixing unit 30 includes an expansion member 31 and a fixing member 32. The expansion member 31 is at least partially disposed in the second groove 24 and has a through hole 311. The fixing member 32 is at least partially disposed in the second through hole 311 and is used to compress the expansion member 31 and the second sealing part 22.

[0085] In actual operation, after the seal 20 is installed into the base 10, the expansion member 31 and the fixing member 32 are installed in sequence. When it is necessary to perform operations such as replenishing liquid, replenishing lithium, or venting and depressurizing, the fixing member 32, the expansion member 31 and the seal 20 are removed in sequence, and the first through hole 15 is exposed to facilitate subsequent operations such as replenishing liquid, replenishing lithium, or venting and depressurizing through the first through hole 15.

[0086] The expansion member 31 can be made of elastic materials such as rubber or silicone, and the expansion member 31 and the sealing member 20 can be made of the same or different materials, depending on the requirements. The fixing member 32 can be made of elastic or rigid materials. Preferably, the fixing member 32 is made of rigid materials to stably provide extrusion force to the expansion member 31 and the second sealing part 22.

[0087] Specifically, the fixing member 32 presses the expansion member 31 in a direction parallel to the radial direction of the first through hole 15, and the expansion member 31 in turn presses the first sealing part 21 to form a seal between the side peripheral surface 211 of the first sealing part 21 and the side wall surface 1111 of the first groove 111. The fixing member 32 presses the second sealing part 22 in the through direction of the first through hole 15, so that the second sealing part 22 can form a seal with the end face of the protrusion 12 facing the second sealing part 22. Moreover, under the pressing action of the fixing member 32, the third sealing part 23 is also difficult to dislodge from the first through hole 15. It can be seen that by designing the expansion member 31 and the fixing member 32, the sealing member 20 and the base 10 can achieve multiple seals and form a relatively tortuous, complex and long sealing path, thereby improving the sealing effect of the sealing member 20 and the base 10.

[0088] Please see Figure 5Furthermore, in some embodiments, the second through hole 311 includes a first sub-hole 3111, a second sub-hole 3112, and a third sub-hole 3113, which gradually approach the first through hole 15; the cross-sectional area of ​​the first sub-hole 3111 is greater than that of the second sub-hole 3112, which is greater than that of the third sub-hole 3113. That is, in the through direction of the first through hole 15, the cross-sectional areas of the first sub-hole 3111, the second sub-hole 3112, and the third sub-hole 3113 gradually decrease. Therefore, as the insertion depth of the fixing member 32 increases, the portion of the expansion member 31 with the second sub-hole 3112 and the third sub-hole 3113, due to its smaller cross-sectional area, will be compressed and expand outwards, thereby compressing the sealing member 20, causing the sealing member 20 to reach the designed compression amount and seal the first groove 111. The portion of the fastener 32 with the first sub-hole 3111 has a larger cross-sectional area, resulting in less mutual compression with the expansion member 31, thus allowing the fastener 32 to be subsequently removed from the expansion member 31.

[0089] It is worth mentioning that, in order to prevent the fixing member 32 from sliding out of the second through hole 311, threads can be provided on both the hole wall of the second through hole 311 and the outer peripheral surface of the fixing member 32. Since the expansion member 31 is an elastic material and the elastic material is a non-metallic material, the fixing member 32 will not slip when it is screwed into the second through hole 311, and will not cause the problem of short circuit of the battery cell.

[0090] Please see Figure 5 and Figure 7 In some embodiments, the expansion member 31 includes a first expansion portion 312 and a plurality of second expansion portions 313. The first expansion portion 312 is annular and surrounds a first sub-hole 3111. The second expansion portions 313 are connected to the first expansion portion 312, and all the second expansion portions 313 are spaced apart and surround a second sub-hole 3112 and a third sub-hole 3113.

[0091] Understandably, the first expansion portion 312 can be used to install the second expansion portion 313. With all the second expansion portions 313 spaced apart and surrounding the second sub-hole 3112 and the third sub-hole 3113, all the second expansion portions 313 can be uniformly expanded outward and squeezed by the pressure of the fixing member 32, thereby the sealing member 20 can uniformly seal the first groove 111, improving the sealing uniformity and the sealing effect.

[0092] Please see Figure 5Furthermore, in some embodiments, the second expansion portion 313 has a connected first wall surface 3131 and a second wall surface 3132, with the first wall surface 3131 of all the second expansion portions 313 surrounding a second sub-hole 3112, and the second wall surface 3132 of all the second expansion portions 313 surrounding a third sub-hole 3113. The first wall surface 3131 is relative to the central axis of the second through hole 311 (e.g., ...). Figure 5 As shown in L2, the inclined surface is tilted, and in the direction from the first sub-hole 3111 to the third sub-hole 3113, the distance between the central axis of the first wall surface 3131 and the second through hole 311 gradually decreases, while the distance between the central axis of the second wall surface 3132 and the second through hole 311 is equal. The method of forming the second sub-holes 3112 and 3113 with different cross-sectional areas using the first wall surface 3131 and the second wall surface 3132 is simple and convenient, improving the manufacturing efficiency of the sealing assembly 100.

[0093] The central axis of the second through hole 311 is parallel to or coincides with the central axis of the first through hole 15. The direction from the first sub-hole 3111 to the third sub-hole 3113 is parallel to or coincides with the through direction of the first through hole 15.

[0094] Please see Figure 1 and Figure 3 In some embodiments, a fourth groove 321 is provided on the top surface of the fastener 32 facing away from the second sealing part 22. The fourth groove 321 is used to cooperate with a tool to screw the fastener 32 in or out.

[0095] Please see Figure 4 and Figure 6 In some embodiments, the third sealing portion 23 includes a first segment 231 and a second segment 232. The first segment 231 is located inside the first through hole 15, and the second segment 232 is located outside the first through hole 15, with the cross-sectional area of ​​the second segment 232 being larger than that of the first segment 231. In this design, when the seal 20 is subjected to an external force in a direction opposite to the through direction of the first through hole 15, the second segment 232 abuts against the plane of the first through hole 15 away from the opening of the second sealing portion 22, preventing itself and the first segment 231 from dislodging from the first through hole 15, thus ensuring reliable assembly of the seal 20.

[0096] Please see Figure 1 , Figure 2 , Figure 4 , Figure 5 , Figure 8 and Figure 9In some embodiments, the base 10 includes a first portion 13 and a second portion 14 connected together. The first portion 13 includes a first main body portion 131 and a first protrusion 132, the first protrusion 132 being disposed on one side of the first main body portion 131. The first portion 13 has a third through hole 133, which sequentially passes through the first main body portion 131 and the first protrusion 132. The second portion 14 includes a second main body portion 141 and a second protrusion. The second main body portion 141, the first main body portion 131, and the first protrusion 132 together form a base body 11. The second main body portion 141 has a first surface 14111 facing the third through hole 133. The first surface 14111 and the hole wall of the third through hole 133 define a first groove 111. The second protrusion is disposed on the first surface 14111 and forms a protrusion 12. The first through hole 15 passes through the second protrusion and the second main body portion 141.

[0097] It is understood that the wall surface of the third through hole 133 is the side wall surface 1111 of the first groove 111, and at least a portion of the first surface 14111 forms the bottom wall surface of the first groove 111.

[0098] The base 10 is formed by connecting the split first part 13 and the second part 14, so that the complex base 10 can be assembled from the relatively simple first part 13 and the second part 14. This design reduces the processing difficulty of the base 10.

[0099] In actual operation, the first sealing part 21 is installed in the third through hole 133, and the third sealing part 23 is installed in the first through hole 15. Then, the first part 13 and the second part 14 are connected to complete the assembly of the base 10 and the sealing element 20. It can be seen that connecting the base 10 with the separate first part 13 and the second part 14 also facilitates the assembly of the sealing element 20.

[0100] Of course, the assembly method of the base 10 and the seal 20 is not limited to the one described above. In some other embodiments, the first part 13 and the second part 14 can be connected first, and then the seal 20 can be assembled.

[0101] The first part 13 is formed by combining the first main body 131 and the first protrusion 132, and the second part 14 includes the second main body 141 and the second protrusion. The first main body 131, the first protrusion 132 and the second main body 141 together form the first groove 111, and the first through hole 15 passes through the second protrusion and the second main body 141. This can meet the depth requirements for installing the seal 20 in the first groove 111 and the first through hole 15, and improve the reliability of the seal 20 installation.

[0102] The first part 13 and the second part 14 are connected by connecting the first main body 131 and the second main body 141. Optionally, the first main body 131 and the second main body 141 can be connected by adhesive bonding, fastener connection, or other methods. Preferably, the first main body 131 and the second main body 141 are connected by welding. Welding provides good sealing, reducing the risk of electrolyte leakage to the outside through the gap between the first main body 131 and the second main body 141, or reducing the risk of external moisture or other substances entering the battery cell through the gap between the first main body 131 and the second main body 141.

[0103] Please see Figure 4 and Figure 5 Furthermore, in some embodiments, the wall surface of the third through hole 133 is an inclined surface that is inclined relative to the central axis of the first through hole 15, and the cross-sectional area of ​​the third through hole 133 gradually increases in the through direction of the first through hole 15.

[0104] By designing the cross-sectional area of ​​the third through hole 133 to gradually increase, the seal 20 can be easily installed inside. When the side peripheral surface 211 of the first sealing part 21 of the seal 20 is also an inclined surface with the same inclination as the hole wall surface of the third through hole 133, the first sealing part 21 and the third through hole 133 can be self-locked, thereby helping to improve the sealing performance.

[0105] Please see Figure 4 and Figure 5 In some embodiments, the first sealing portion 21 extends to and seals against the first surface 14111. This sealing design prevents electrolyte from flowing out of the first through-hole 15 and leaking to the outside. Furthermore, it can prevent leakage from that portion to the outside when cracks or other welding quality problems occur at the weld between the first body portion 131 of the first portion 13 and the second body portion 141 of the second portion 14, leading to leakage.

[0106] Please see Figure 4 , Figure 5 , Figure 8 and Figure 9In some embodiments, the first main body portion 131 is recessed in a direction away from the second main body portion 141 to form a first recess 1311, and the first protrusion 132 is partially located in the first recess 1311. The second main body portion 141 is recessed in a direction away from the first main body portion 131 to form a second recess 1411, and the second protrusion is at least partially located in the second recess 1411. Thus, in the through-direction of the first through-hole 15, the first main body portion 131 and the first protrusion 132 at least partially overlap in height, and the second main body portion 141 and the second protrusion at least partially overlap in height, thereby reducing the size of the sealing assembly 100 in the through-direction of the first through-hole 15 and improving the space utilization of the sealing assembly 100.

[0107] Please continue reading. Figure 4 Furthermore, in some embodiments, the first protrusion 132 extends at least partially into the second recess 1411. In this design, the first protrusion 132 and the second main body 141 at least partially overlap in height in the through-hole 15, thereby reducing the size of the sealing assembly 100 in the through-hole 15, further improving the space utilization of the sealing assembly 100, and making the structure of the sealing assembly 100 more compact.

[0108] Please see Figure 4 The first main body 131 further includes a first straight portion 1312, which is arranged circumferentially around the first recess 1311. The second main body 141 further includes a second straight portion 1412, which is arranged circumferentially around the second recess 1411.

[0109] In some embodiments, the first straight portion 1312 and the second straight portion 1412 are stacked and connected. This design can increase the contact area between the first straight portion 1312 and the second straight portion 1412, so as to facilitate welding of the first straight portion 1312 and the second straight portion 1412, thereby realizing the connection between the first portion 13 and the second portion 14.

[0110] In some embodiments, the surface of the first straight portion 1312 facing the second straight portion 1412 has a third groove 13121, which extends from the inside to the outside through the side periphery of the first straight portion 1312. The third groove 13121 is used to achieve the overlapping function of the mounting reference of the base 10 and the mounting base 10, so as to facilitate the positioning of the base 10 during the installation process and improve the installation efficiency of the sealing assembly 100.

[0111] In some embodiments, the thickness of the first straight portion 1312 is H1, where 1mm ≤ H1 ≤ 5mm.

[0112] H1 can be, but is not limited to, 1mm, 2.1mm, 4mm, or 5mm.

[0113] If H1 is too small, the structural strength of the first straight section 1312 will be poor, making it prone to cracking during welding. If H1 is too large, it will occupy a large dimension in the through-hole direction of the first through-hole 15, resulting in low space utilization of the sealing assembly 100. Therefore, the design is 1mm≤H1≤5mm, which can ensure structural strength while improving space utilization.

[0114] In some embodiments, the second straight portion 1412 has a second surface 14121 disposed toward the first straight portion 1312, and the distance between the second surface 14121 and the first surface 14111 is H2, where 2mm≤H2≤6mm.

[0115] H2 can be, but is not limited to, 2mm, 3mm, 5mm, 6mm, etc.

[0116] If H2 is too small, the structural strength of the second part 14 will be poor, making it prone to cracking during welding. If H2 is too large, it will occupy a large dimension in the through-hole direction of the first through-hole 15, resulting in low space utilization of the sealing assembly 100. Therefore, the design is 2mm≤H2≤6mm, which can ensure structural strength while improving space utilization.

[0117] In some embodiments, the distance between the two mutually distant surfaces of the second protrusion and the second recess 1411 is H3, where 1.5mm ≤ H3 ≤ 3mm.

[0118] H3 can be, but is not limited to, 1.5mm, 2mm, 2.6mm, 3mm, etc.

[0119] If H3 is too small, the depth of the first through hole 15 is shallow, and the length of the fit between the third sealing part 23 and the hole wall of the first through hole 15 in the through direction of the first through hole 15 is short, resulting in poor sealing performance. If H3 is too large, the depth of the first through hole 15 is large, occupying a large space in the through direction of the first through hole 15, leading to reduced space utilization. Therefore, the design is 1.5mm≤≤H3≤3mm, which can balance sealing performance and space utilization.

[0120] In some embodiments, the second straight portion 1412 has a third surface 14122 that is away from the first straight portion 1312, and the second recess 1411 has a fourth surface 14112 that is disposed opposite to the first surface 14111. The distance between the third surface 14122 and the fourth surface 14112 is H4, where 3mm≤H4≤6mm.

[0121] H4 can be, but is not limited to, 3mm, 3.5mm, 5mm, 6mm, etc.

[0122] If H4 is too small, the structural strength of the second part 14 will be poor, making it prone to cracking during welding. If H4 is too large, it will occupy a large dimension in the through-hole direction of the first through-hole 15, resulting in low space utilization of the sealing assembly 100. Therefore, the design is 3mm≤H4≤6mm, which can ensure structural strength while improving space utilization.

[0123] Please continue reading. Figure 4 In some embodiments, the surfaces of the seal 20, the fixing unit 30, and the base body 11 that are furthest from the first through hole 15 are flush. This allows the seal 20 and the fixing unit 30 to be neatly concealed, reducing the risk of them protruding from the base 10 and being scraped off or damaged. Furthermore, this design also reduces the dimensions of the sealing assembly 100 in the through direction of the first through hole 15, improving the space utilization of the sealing assembly 100.

[0124] Please see Figure 4 and Figure 5 In some embodiments, the diameter of the opening of the first groove 111 away from the first through hole 15 is D, where 5mm≤D≤20mm.

[0125] Where D can be, but is not limited to, 5mm, 12mm, 18mm, 20mm, etc.

[0126] If D is too small, it will be inconvenient to install and remove the seal 20; if D is too large, it will occupy a large space in the radial direction of the first groove 111, resulting in low space utilization of the sealing assembly 100 in this direction. Therefore, the design is 5mm≤D≤20mm, which not only facilitates the installation and removal of the seal 20, but also improves the space utilization of the sealing assembly 100 in the radial direction of the first groove 111.

[0127] It is understood that the radial direction of the first groove 111 is parallel to the radial direction of the first through hole 15.

[0128] This application also provides a battery cell, which includes a housing, an electrode assembly, and a sealing assembly 100 as described in any of the above embodiments. The sealing assembly 100 is mounted on the housing, and the electrode assembly is disposed inside the housing.

[0129] It is understandable that the housing is the mounting reference mentioned above.

[0130] Specifically, the housing has a receiving cavity and an opening communicating with the receiving cavity. The electrode assembly is disposed in the receiving cavity, and the base 10 of the sealing assembly 100 covers the opening of the housing to seal the electrode assembly. Specifically, the first part 13 of the base 10 covers the opening of the housing.

[0131] Optionally, the housing includes any two of the bottom plate, side plate and top plate, and these two are arranged to form a receiving cavity, with the base 10 serving as the third of the bottom plate, side plate and top plate and covering the opening.

[0132] Optionally, the housing includes a bottom plate, a side plate, and a top plate. The side plate is connected between the bottom plate and the top plate and is arranged circumferentially around the bottom plate. The bottom plate, the side plate, and the top plate define a receiving cavity. A partial area of ​​one of the bottom plate, the side plate, and the top plate has an opening, and the base 10 covers the opening.

[0133] The battery cell in this application has the effects of any of the above embodiments, so it will not be described again here.

[0134] The aforementioned sealing assembly 100 and battery cell, base 10, seal 20 and fixing unit 30 cooperate to repeatedly perform operations such as replenishing electrolyte, replenishing lithium, venting and depressurizing through the first through hole 15 by disassembling the fixing unit 30 and the seal 20, thereby improving the safety of the battery cell and extending the battery's service life. By installing and removing the fixing unit 30 and the seal 20, the first through hole 15 and the first groove 111 can be sealed, and a better sealing effect can be achieved to achieve the purpose of effectively isolating the inside and outside of the battery cell.

[0135] The technical features of the above embodiments can be combined in any way. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0136] The embodiments described above are merely illustrative of several implementation methods of this application, and while the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the patent application. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Therefore, the protection scope of this patent application should be determined by the appended claims.

Claims

1. A seal assembly characterized by, The sealing assembly includes: The base (10) includes a base body (11), a protrusion (12) and a first through hole (15). The base body (11) has a first groove (111). The protrusion (12) is located in the first groove (111) and protrudes from the bottom wall of the first groove (111). The first through hole (15) passes through the protrusion (12) and the base body (11) in sequence. The sealing element (20) includes a first sealing part (21), a second sealing part (22) and a third sealing part (23) connected in sequence. The first sealing part (21) is located in the first groove (111) and sleeved on the outside of the protrusion (12). The second sealing part (22) is located in the first sealing part (21) and defines a second groove (24) with the first sealing part (21). The second groove (24) is disposed away from the first through hole (15). The second sealing part (22) covers the first through hole (15). The third sealing part (23) is at least partially located in the first through hole (15). The fixing unit (30) is at least partially detachably disposed in the second groove (24) and is used to press the seal (20) together with the base (10).

2. The sealing assembly according to claim 1, characterized in that, The side wall surface (1111) of the first groove (111) and the side peripheral surface (211) of the first sealing part (21) facing the side wall surface (1111) are both inclined surfaces that are inclined relative to the bottom wall surface of the first groove (111). In the through direction of the first through hole (15), the cross-sectional area of ​​the side wall surface (1111) of the first groove (111) and the cross-sectional area of ​​the side peripheral surface (211) of the first sealing part (21) gradually increase.

3. The sealing assembly according to claim 1, characterized in that, The fixing unit (30) includes an expansion member (31) and a fixing member (32). The expansion member (31) is at least partially disposed in the second groove (24) and has a through hole (311). The fixing member (32) is at least partially disposed in the second through hole (311) and is used to squeeze the expansion member (31) and the second sealing part (22).

4. The sealing assembly according to claim 3, characterized in that, The second through hole (311) includes a first sub-hole (3111), a second sub-hole (3112) and a third sub-hole (3113), with the first sub-hole (3111), the second sub-hole (3112) and the third sub-hole (3113) gradually approaching the first through hole (15); The cross-sectional area of ​​the first sub-hole (3111) is greater than the cross-sectional area of ​​the second sub-hole (3112) and the cross-sectional area of ​​the third sub-hole (3113).

5. The sealing assembly according to claim 4, characterized in that, The expansion member (31) includes a first expansion portion (312) and a plurality of second expansion portions (313). The first expansion portion (312) is annular and surrounds the first sub-hole (3111). The second expansion portions (313) are connected to the first expansion portion (312), and all the second expansion portions (313) are spaced apart and surround the second sub-hole (3112) and the third sub-hole (3113).

6. The sealing assembly according to claim 5, characterized in that, The second expansion portion (313) has a first wall surface (3131) and a second wall surface (3132) connected together. The first wall surface (3131) of all the second expansion portions (313) surrounds to form the second sub-hole (3112), and the second wall surface (3132) of all the second expansion portions (313) surrounds to form the third sub-hole (3113). The first wall surface (3131) is an inclined surface that is inclined relative to the central axis of the second through hole (311), and in the direction from the first sub-hole (3111) to the third sub-hole (3113), the distance between the first wall surface (3131) and the central axis of the second through hole (311) gradually decreases, and the distance between the second wall surface (3132) and the central axis of the second through hole (311) is equal.

7. The sealing assembly according to claim 1, characterized in that, The third sealing part (23) includes a first section (231) and a second section (232). The first section (231) is located inside the first through hole (15), and the second section (232) is located outside the first through hole (15). The cross-sectional area of ​​the second section (232) is greater than that of the first section (231).

8. The sealing assembly according to claim 1, characterized in that, The base (10) includes a first part (13) and a second part (14) connected together. The first part (13) includes a first main body (131) and a first protrusion (132). The first protrusion (132) is disposed on one side of the first main body (131). The first part (13) has a third through hole (133), which passes through the first main body (131) and the first protrusion (132) in sequence. The second part (14) includes a second main body (141) and a second protrusion. The second main body (141), together with the first main body (131) and the first protrusion (132), forms the seat body (11). The second main body (141) has a first surface (14111) facing the third through hole (133). The first surface (14111) and the hole wall of the third through hole (133) define the first groove (111). The second protrusion is disposed on the first surface (14111) and forms the protrusion (12). The first through hole (15) passes through the second protrusion and the second main body (141).

9. The sealing assembly according to claim 8, characterized in that, The wall surface of the third through hole (133) is an inclined surface that is inclined relative to the central axis of the first through hole (15). In the penetrating direction of the first through hole (15), the cross-sectional area of ​​the third through hole (133) gradually increases. And / or, the first sealing portion (21) extends to the first surface (14111).

10. The sealing assembly according to claim 8, characterized in that, The first main body portion (131) is recessed in a direction away from the second main body portion (141) to form a first recess (1311), and the first protrusion (132) is partially located in the first recess (1311); and The second main body portion (141) is recessed in a direction away from the first main body portion (131) to form a second recess (1411), and the second protrusion is at least partially located in the second recess (1411).

11. The sealing assembly according to claim 10, characterized in that, The first protrusion (132) extends at least partially into the second recess (1411).

12. The sealing assembly according to claim 10, characterized in that, The first main body portion (131) further includes a first straight portion (1312) disposed circumferentially around the first recess (1311), and the second main body portion (141) further includes a second straight portion (1412) disposed circumferentially around the second recess (1411), wherein the sealing assembly satisfies at least one of (1) to (6): (1) The first straight portion (1312) and the second straight portion (1412) are stacked and connected; (2) The surface of the first straight portion (1312) facing the second straight portion (1412) has a third groove (13121), which extends from the inside to the outside through the side periphery of the first straight portion (1312); (3) The thickness of the first straight part (1312) is H1, 1mm≤H1≤5mm; (4) The second straight portion (1412) has a second surface (14121) disposed toward the first straight portion (1312), and the distance between the second surface (14121) and the first surface (14111) is H2, 2mm≤H2≤6mm; (5) The distance between the two surfaces of the second convex part and the second concave part (1411) that are far apart from each other is H3, 1.5mm≤H3≤3mm; (6) The second straight portion (1412) has a third surface (14122) away from the first straight portion (1312), and the second recess (1411) has a fourth surface (14112) opposite to the first surface (14111). The distance between the third surface (14122) and the fourth surface (14112) is H4, 3mm≤H4≤6mm.

13. The sealing assembly according to claim 1, characterized in that, The surfaces of the sealing element (20), the fixing unit (30), and the seat body (11) are flush with the surfaces away from the first through hole (15); and / or, the diameter of the opening of the first groove (111) away from the first through hole (15) is D, 5mm≤D≤20mm.

14. A single battery cell, characterized in that, It includes a housing, an electrode assembly, and a sealing assembly as described in any one of claims 1 to 13, wherein the sealing assembly is mounted on the housing and the electrode assembly is disposed within the housing.

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