A sealing assembly, an electric cell, a battery pack and a mounting method thereof

Abstract

The application belongs to the technical field of battery packs, and provides a sealing assembly, a battery cell, a battery pack and a mounting method thereof, mainly comprising a bearing surface, a ball and an end cover, wherein the ball is arranged on the bearing surface; a groove is arranged on the end cover, the bottom end of the groove is provided with a via hole, the diameter of the via hole is smaller than the diameter of the ball; the groove is sleeved on the ball, and the inner wall surface of the groove is in abutment with the outer surface of the ball to form a sealed contact. In the scheme, the via hole is sealed by mechanical pressing, which can effectively avoid the influence of residual electrolyte on the welding sealing, compared with the welding sealing method in the traditional technology. Moreover, the mechanical pressing method does not need to weld the via hole, so that the assembly efficiency can be improved, and mass production of products can be facilitated.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery pack, and particularly relates to a sealing assembly, a battery cell, a battery pack and a mounting method thereof. BACKGROUND

[0002] At present, for a middle-large size cylindrical battery, a small round hole needs to be formed on an end cover, electrolyte is injected into the battery cell through the small round hole on the end cover, and then the sealing nail is welded to the small round hole by laser, so that the battery is sealed. However, it is found in actual use that electrolyte residues often occur around the injection port formed by the small round hole, and the electrolyte residues are prone to form crystalline substances in a low-humidity environment. The crystalline substances as impurities form welding explosion points, causing poor welding sealing. In addition, the efficiency of laser welding is low, which is not conducive to mass production of products. SUMMARY

[0003] In order to overcome the above-mentioned defects in the prior art, the purpose of the application is to provide a sealing assembly, a battery cell, a battery pack and a mounting method thereof, which can effectively avoid the influence of residual electrolyte on the sealing operation and facilitate mass production of products.

[0004] The technical means adopted by the application to solve the above technical problems is:

[0005] The application provides a sealing assembly, which comprises:

[0006] a bearing surface;

[0007] a ball, which is arranged on the bearing surface;

[0008] an end cover, which is provided with a groove, the bottom end of the groove is provided with a through hole, the diameter of the through hole is smaller than the diameter of the ball, the groove is sleeved on the ball, and the inner wall surface of the groove is in abutment with the outer surface of the ball to form a sealed contact.

[0009] In the implementation process, the via hole is arranged at the bottom end of the groove. In application, electrolyte can be delivered through the via hole. After the delivery of electrolyte is completed, the groove is sleeved on the ball by pressure sealing, so as to form a sealed contact between the groove and the ball, and the via hole is sealed. Compared with the conventional technology of welding the via hole, the mechanical pressure sealing method can effectively avoid the influence of residual electrolyte on poor welding. Moreover, the mechanical pressure sealing method does not need to weld the via hole, so that the assembly efficiency can be improved, and mass production of products can be facilitated. In addition, in the mechanical pressure sealing method, the groove and the ball have a certain deformation range under the condition that the pressure meets the condition. Therefore, the via hole can also be used as a pressure relief hole, and the design is ingenious.

[0010] Preferably, the outer surface of the ball is coated with a sealing structure layer.

[0011] In the implementation process, the sealing structure layer can improve the sealing effect between the groove and the ball.

[0012] Preferably, the inner wall surface of the groove has a bending section, and the bending range of the bending section is matched with the surface shape of the ball.

[0013] In the implementation process, the bending section can further improve the sealing effect between the groove and the ball.

[0014] Preferably, the end cover includes a body, the bottom end of the groove is protrudingly arranged towards one side of the body, and the opening end of the groove is protrudingly arranged towards the other side of the body. The opening end of the groove and the body are connected to form an inner recessed rib groove.

[0015] In the implementation process, the inner recessed rib groove makes the groove have a deeper side wall structure, improves the fitting degree between the groove and the ball, and facilitates deformation of the side wall structure of the groove when the pressure on the ball side increases, so as to meet the structural design requirements when the stress suddenly changes.

[0016] The application also provides an electric core including a core body, a shell arranged outside the core body, and a sealing assembly arranged at the end of the core body. The end cover is sealingly connected to the shell.

[0017] In the implementation process, the secondary injection and sealing of the electrolyte can be realized by controlling the gap between the groove and the ball by applying the sealing assembly in the battery cell; this structure does not need to be laser welded around the via, which can effectively eliminate the adverse effects of residual electrolyte on welding and improve the production yield; at the same time, the via has a directional pressure relief function, so there is no need to perform a notch operation on the end cover, which avoids the unstable pressure phenomenon caused by poor notching; when the internal pressure of the battery cell increases to a certain extent, the side wall of the groove arches outward and separates from the ball; when the internal pressure of the battery cell continues to increase, the ball arches outward to cause the via to crack around and realize directional pressure relief.

[0018] Preferably, the shell is bent towards the inside to form a limiting portion; the core body is arranged on one side of the limiting portion, and the end cover is arranged on the other side of the limiting portion.

[0019] In the implementation process, the limiting portion formed can facilitate the limiting operation of the installation position of the core body and facilitate the cooperation and installation of the subsequent current collecting member.

[0020] Preferably, the end of the shell is bent towards the inside to form an inward flanging structure, an installation groove is formed between the inward flanging structure and the limiting portion, the end cover is embedded in the installation groove, and the end cover and the installation groove are sealingly connected.

[0021] In the implementation process, the installation groove formed can facilitate the installation and sealing connection between the end cover and the shell.

[0022] Preferably, the end of the core body is provided with a current collecting member, the current collecting member is provided with a stand shoulder structure, the cross-sectional shape of the stand shoulder structure is matched with the cross-sectional shape of the limiting portion, and the stand shoulder structure is connected with the limiting portion.

[0023] In the implementation process, the stand shoulder structure formed can be lapped and cooperated with the limiting portion to make the contact between the current collecting member and the shell more sufficient.

[0024] Preferably, a supporting rod is arranged in the core body, the end of the supporting rod is provided with an adjusting member, and the ball is arranged on the adjusting member.

[0025] In the implementation process, the adjusting member arranged can facilitate the adjustment of the relative setting height of the ball and can avoid the damage of the ball directly acting on the core body.

[0026] The application also provides a battery pack provided with the sealing assembly.

[0027] Or, it is provided with an electric core as described above.

[0028] The application also provides an installation method, which is suitable for the electric core and includes the following steps:

[0029] The core body and the current collector are placed in the shell in sequence, wherein the shell has a first extension part arranged above the core body, the edge of the current collector has a second extension part, and a deformation gap is reserved between the first extension part and the second extension part;

[0030] The first extension part and the second extension part are synchronously deformed to form a limiting part bent towards the inner side of the shell on the first extension part, a stand shoulder structure matched with the cross-sectional shape of the limiting part on the second extension part, and a connecting treatment between the limiting part and the stand shoulder structure;

[0031] The sealing assembly is arranged on the core body, and the end cover is sealingly connected with the shell. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed to be used in the embodiments of the application will be briefly introduced as follows. It should be understood that the following drawings only show some embodiments of the application, and therefore should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can also be obtained without creative labor on the basis of these drawings.

[0033] Figure 1 It is a schematic diagram of the installation structure of the sealing assembly of the application.

[0034] Figure 2 It is a schematic diagram of the top view structure of the current collector of the application.

[0035] Figure 3 It is a schematic diagram of the pre-installation structure of the current collector on the core body of the application.

[0036] Figure 4 It is a schematic diagram of the structure of the shell and the current collector after deformation treatment of the application.

[0037] Figure 5 It is a schematic diagram of the connecting structure of the stand shoulder structure and the limiting part of the application.

[0038] Label explanation:

[0039] 1-rolling ball, 11-sealing structure layer;

[0040] 2-end cover, 21-groove, 211-bent section, 22-via hole, 23-internal recessed rib groove, 24-sealing element;

[0041] 3-core, 31-supporting rod, 32-adjusting member;

[0042] 4-housing, 41-limiting part, 42-inward flanging structure, 43-first extending part;

[0043] 5-current collecting member, 51-through hole, 52-stiffener, 53-shoulder structure, 54-second extending part. DETAILED DESCRIPTION

[0044] In order to more clearly understand the above-mentioned purposes, features and advantages of the present application, the present application will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be noted that the embodiments and features in the embodiments can be combined with each other without conflict. In the following description, a large number of specific details are described in order to facilitate a full understanding of the present application, and the described embodiments are only part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

[0045] It should be noted that: unless otherwise defined, all technical and scientific terms used herein have the same meaning as understood by those skilled in the art to which the present application belongs. The terms used in the specification of the present application herein are only for the purpose of describing the specific embodiments and are not intended to limit the present application. Similar reference numbers and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in subsequent drawings. At the same time, in the description of the present application, the terms "first", "second", etc. are only used for distinction and cannot be understood as indicating or implying relative importance.

[0046] As Figures 1-5 shown, the sealing assembly provided in the embodiment mainly includes a bearing surface, a plurality of balls 1 and an end cover 2. The bearing surface is mainly used for bearing the balls 1, so the specific structure to which the bearing surface is attached is not unique and needs to be determined according to the bearing structure in actual application.

[0047] The balls 1 in the embodiment are spherical beads, which can be made of metal material or non-metal material, which is not specifically limited here. As a preferred scheme, a sealing structure layer 11 is provided on the outer surface of the ball 1 in the embodiment, such as an elastic colloidal material coated on the surface of the ball 1, so as to improve the sealing effect of the ball 1 in the sealed installation state.

[0048] Furthermore, a groove 21 is provided on the end cap 2. During installation, the groove 21 is fitted onto the ball bearing 1. At the same time, a through hole 22 is provided at the bottom end of the groove 21, and the diameter of the through hole 22 is set to be smaller than the diameter of the ball bearing 1. In application, electrolyte can be transported through the through hole 22. After the electrolyte is transported, a pressure sealing method is used to make the inner wall surface of the groove 21 abut against the outer surface of the ball bearing 1, thereby forming a sealed contact between the groove 21 and the ball bearing 1 to seal the through hole 22.

[0049] As a preferred embodiment, the inner wall of the groove 21 has a bent section 211, wherein the bent section 211 is located at the bottom end of the groove 21 and close to the through hole 22, and the bending radius of the bent section 211 is adapted to the surface shape of the ball 1, so that the ball 1 and the bent section 211 can fit better, further improving the sealing effect between the groove 21 and the ball 1.

[0050] As a preferred embodiment, in this case, the end cap 2 includes a body, and the groove 21 and the through hole 22 are disposed at the center of the body; wherein, the bottom end of the groove 21 protrudes towards one side of the body, and the opening end of the groove 21 protrudes towards the other side of the body, as shown below. Figure 1 As shown, the opening end of the groove 21 is connected to the body to form an inner concave groove 23. The formed inner concave groove 23 allows the groove 21 to have a deeper sidewall structure, unrestricted by the thickness of the body, resulting in a larger contact area between the groove 21 and the ball 1, thus improving the fit between them. Simultaneously, when the pressure on the ball 1 side increases, the ball 1 will first promote deformation of the sidewall structure of the groove 21 under pressure to achieve pressure relief. When the groove 21 has a shorter sidewall structure, the ball 1 often needs to deform the entire end cap 2 under pressure to achieve pressure relief. Therefore, this solution better meets the structural design requirements under sudden stress changes.

[0051] In the embodiment, the mechanical pressure sealing between the groove 21 and the ball 1 can effectively avoid the influence of residual electrolyte on the welding operation in the conventional technology, and the mechanical pressure sealing does not need to weld the via hole, so that the welding process is avoided, the assembly efficiency is improved, and the mass production of products is facilitated. In addition, the mechanical pressure sealing in the embodiment allows the groove 21 and the ball 1 to have a certain deformation amplitude under the condition that the pressure meets the condition, so that the via hole 22 can also be used as a pressure relief hole, and the design is ingenious.

[0052] In addition, the embodiment also provides an electric core, which is exemplified by a cylindrical winding type electric core; the electric core comprises a core body 3 and a shell 4 arranged outside the core body 3 and used for covering the core body 3, and a sealing assembly as described above is arranged at the end of the core body 3, and the end cover 2 is sealingly connected with the shell 4.

[0053] As one of the application examples, the ball 1 is arranged at the end of the core body 3, and thus the end plane of the core body 3 is the bearing surface.

[0054] As a preferred scheme, in the embodiment, the core body 3 is wound on a support rod 31, and an adjusting member 32 is detachably arranged at the end of the support rod 31, and the ball 1 is arranged on the adjusting member 32; at this time, the end plane of the adjusting member 32 is the bearing surface. By arranging the adjusting member 32, the relative arrangement height of the ball 1 can be adjusted, and the ball 1 directly acting on the core body 3 can be avoided.

[0055] In addition, the shell 4 is bent towards the inner side to form a limiting portion 41; at this time, the core body 3 is arranged at the bottom side of the limiting portion 41, and the end cover 2 is arranged at the top side of the limiting portion 41, as shown in the accompanying drawings. The limiting portion 41 can limit the installation position of the core body 3, and can also facilitate the cooperation and installation of the subsequent current collecting member 5. Figure 1

[0056] Further, in the embodiment, the end of the shell 4 is also bent towards the inner side to form an inward turning edge structure 42, and the inward turning edge structure 42 and the limiting portion 41 form an installation groove, and the edge of the end cover 2 is embedded in the installation groove.

[0057] ​As a preferred scheme, in the embodiment, the seal 24 is arranged at the edge of the end cover 2; when installed, the seal 24 is clamped into a U shape between the inward flanging structure 42 and the limiting portion 41, so that the seal connection between the end cover 2 and the installation groove is realized through the arrangement of the seal 24.

[0058] Further, in the embodiment, the current collector 5 is further arranged at the end of the core 3, a plurality of through holes 51 are arranged at the center of the current collector 5 and around the center, and a reinforcing rib 52 in the form of a protrusion is further arranged between two through holes arranged around the center, so that a certain height difference is formed between the through holes and the reinforcing rib 52, so as to facilitate the effective contact between the welding position of the current collector 5 and the tab.

[0059] As a preferred scheme, in the embodiment, the shoulder structure 53 is arranged at the edge of the current collector 5, and the cross-sectional shape of the shoulder structure 53 is matched with the cross-sectional shape of the limiting portion 41, such as both being in the form of a U shape; the formed shoulder structure 53 can be lapped and matched with the limiting portion 41, so that the contact between the current collector 5 and the shell 4 can be more sufficient.

[0060] The top end of the shoulder structure 53 is lapped and arranged on the top end side of the limiting portion 41, and the top end of the shoulder structure 53 is welded with the limiting portion 41.

[0061] In the embodiment, the seal assembly is applied in the battery cell, and the secondary injection and sealing of the electrolyte can be realized by controlling the gap between the groove 21 and the ball 1; such a structure does not need to be laser welded around the via hole 22, can effectively eliminate the adverse effects of residual electrolyte on welding, and improve the production yield; at the same time, the via hole 22 has a directional pressure relief function, so that the scoring operation of the end cover 2 is not needed, and the unstable pressure resistance phenomenon introduced by the scoring defect is avoided; when the internal pressure of the battery cell increases to a certain extent, the side wall of the groove 21 is arched outward and separated from the ball 1, and after the internal pressure of the battery cell continues to increase, the ball 1 is arched outward, the via hole 22 is cracked around, and the directional pressure relief is realized.

[0062] In addition, the embodiment also provides a battery pack, and the battery pack is provided with the seal assembly or the battery cell as described above.

[0063] In the embodiment, the specific structure of the battery pack can be referred to the prior art, and details are not described herein.

[0064] In addition, in order to facilitate further understanding of the scheme, the embodiment also provides an installation method, which is suitable for the battery cell as described above, and mainly includes the following steps:

[0065] S10. After the core 3 is wound on the support rod 31, it is placed in the shell 4, and then the current collector 5 is placed on the top end face of the core 3; wherein the current collector 5 is coaxially arranged with the support rod 31. At this time, the shell 4 has a first extension 43 arranged higher than the core 3, and the current collector 5 has a second extension 54 arranged higher than the body thereof, and in this embodiment, a deformation gap is reserved between the first extension 43 and the second extension 54.

[0066] S20. The first extension 43 and the second extension 54 are subjected to synchronous deformation processing, such as roller groove processing. After the roller groove processing, the limiting portion 41 is formed on the first extension 43, which is bent towards the inside of the shell 4, and the vertical shoulder structure 53 is formed on the second extension 54, which is also bent towards the inside of the shell 4; at this time, the limiting portion 41 has a large bending deformation, and the deformation amplitude of the vertical shoulder structure 53 is relatively small, and the cross-sectional shape between the limiting portion 41 and the vertical shoulder structure 53 is adapted, so that the vertical shoulder structure 53 can better fit the limiting portion 41, and then the vertical shoulder structure 53 and the limiting portion 41 after fitting are welded and connected, as shown in Figure 5

[0067] S30. After the welding connection between the vertical shoulder structure 53 and the limiting portion 41 is completed, the first electrolyte injection operation can be performed. At this time, during the negative pressure formation, the adjusting piece 32 is installed on the support rod 31, then the ball 1 and the end cover 2 are placed, and the mechanical seal between the edge of the end cover 2 and the shell 4 is completed. At this time, there is a certain distance between the ball 1 and the via hole 22, so the via hole 22 can be used as a release channel for formation gas during the formation operation.

[0068] S40. According to actual needs, the core 3 is subjected to secondary liquid supplementing through the via hole 22, and then the secondary mechanical pressure sealing operation is performed on the battery cell to eliminate the gap between the adjusting piece 32, the ball 1 and the end cover 2, and form a sealed structure.

[0069] ​The above description is only the specific implementation of this application, and is not used to limit the protection scope of this application. For those skilled in the art, this application can have various modifications and changes. Any modification, equivalent replacement, improvement, etc. within the spirit and principle of this application should be included in the protection scope of this application. Any person skilled in the art can easily think of changes or replacements within the technical range disclosed in this application, which should also be included in the protection scope of this application. Therefore, the protection scope of this application should be subject to the protection scope of the claims.

[0070] It should be noted that the relative terms such as first and second, and the like, are used herein only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between such entities or operations. Moreover, the terms "comprises", "comprising", or any other variations thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element preceded by "comprises a" does not, without more limitations, preclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

Claims

1. A seal assembly characterized by, The application relates to a sealing assembly for an electrolyte injection device. The sealing assembly comprises a bearing surface, a ball arranged on the bearing surface, and an end cover provided with a groove, wherein the bottom end of the groove is provided with a through hole, the diameter of the through hole is smaller than that of the ball, the groove is sleeved on the ball, the inner wall surface of the groove is in abutting contact with the outer surface of the ball to form a sealed contact, and the groove and the ball are allowed to have a certain deformation range to serve as a pressure relief hole when the pressure meets the condition. The outer surface of the ball is provided with a sealing structure layer. The inner wall surface of the groove is provided with a bending section, and the bending range of the bending section is matched with the surface shape of the ball. The end cover comprises a body, the bottom end of the groove is protruded towards one side of the body, the opening end of the groove is protruded towards the other side of the body, and the opening end of the groove is connected with the body to form an inner recessed rib groove. The application further discloses a battery cell comprising a core body, a shell arranged outside the core body, and a sealing assembly arranged at the end of the core body.

2. The seal assembly of claim 1, wherein, The shell is bent towards the inner side to form a limiting part, the core body is arranged on one side of the limiting part, and the end cover is arranged on the other side of the limiting part.

3. The seal assembly of claim 1 or 2, wherein, The end of the shell is bent towards the inner side to form an inner turned edge structure, the inner turned edge structure and the limiting part form an installation groove, the end cover is embedded in the installation groove, and the end cover is sealingly connected with the installation groove.

4. The seal assembly of claim 3, wherein, The end of the core body is provided with a current collector, the current collector is provided with a vertical shoulder structure, the cross-sectional shape of the vertical shoulder structure is matched with that of the limiting part, and the vertical shoulder structure is connected with the limiting part.

5. An electric cell characterized by The core body is provided with a supporting rod, the end of the supporting rod is provided with an adjusting piece, and the ball is arranged on the adjusting piece.

6. The electric cell of claim 5, wherein, The application further discloses a battery cell comprising a sealing assembly as claimed in any one of claims 1-4.

7. The electric cell of claim 6, wherein, The application further discloses a battery cell comprising a sealing assembly as claimed in any one of claims 5-9.

8. The cell of claim 6 or 7, wherein, The application further discloses a battery cell comprising the following steps.

9. The electric cell of claim 8, wherein, The core body and the current collector of a battery cell are sequentially arranged in a shell, the shell is provided with a first extension part higher than the core body, the edge of the current collector is provided with a second extension part, and a deformation gap is reserved between the first extension part and the second extension part.

10. A battery pack, characterized by, The first extension part and the second extension part are synchronously deformed to form a limiting part bent towards the inner side of the shell on the first extension part, a vertical shoulder structure matched with the cross-sectional shape of the limiting part on the second extension part, and a connecting process between the limiting part and the vertical shoulder structure. The sealing assembly is arranged on the core body, and the end cover is sealingly connected with the shell.

11. A method of installation suitable for use with an electrical core as claimed in any one of claims 5 to 9, characterised in that, ​ ​ ​ ​

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