Secondary battery and battery pack

Abstract

The utility model provides a kind of secondary battery, including shell, electrode assembly, adapter piece, cover plate and support structure;The first end of shell is equipped with opening, the inside of the side wall of shell first end is equipped with rolling groove;Electrode assembly is housed in shell;Adapter piece is between electrode assembly and rolling groove;Cover plate is connected with the first end of shell, and opening is closed with sealing element between shell and rolling groove;Support structure is housed between electrode assembly and cover plate, and there is gap between rolling groove and electrode assembly, and gap size is not less than 1.5mm.The utility model is through the support structure of being additionally arranged between electrode assembly and cover plate, ensure that the exhaust passage formed in shell has stable gap, maintain the pressure relief efficiency under heat runaway condition, to solve the problem that high-temperature active substance is easily accumulated in the rolling groove dead corner area of shell when heat runaway, leading to pressure cannot be released in time, increase the risk of explosion or shell tearing.

Description

Technical Field

[0001] This utility model relates to the field of battery cell structure technology, and in particular to a secondary battery and battery pack. Background Technology

[0002] To improve the sealing reliability, safety, and long lifespan of cylindrical batteries, a specific groove (i.e., a grooving groove) is machined into the cylindrical battery casing (usually a steel or aluminum casing) using a grooving process. This grooving groove, in conjunction with the battery cover and sealing ring, achieves a high-pressure seal between the battery's interior and the external environment through mechanical compression.

[0003] However, during thermal runaway, high-temperature active materials tend to accumulate in the dead corners of the casing's grooves, preventing timely pressure release and increasing the risk of explosion or casing tearing. Utility Model Content

[0004] In view of the shortcomings of the prior art described above, the present invention provides a secondary battery and battery pack. By adding a support structure between the electrode assembly and the cover plate, the exhaust channel formed in the shell has a stable gap, maintaining the pressure relief efficiency under thermal runaway conditions. This solves the problem that high-temperature active materials tend to accumulate in the dead corner area of ​​the shell's grooves during thermal runaway, resulting in pressure not being released in time and increasing the risk of explosion or shell tearing.

[0005] This utility model provides a secondary battery, comprising:

[0006] The housing has an opening at its first end and a groove on the inner side wall of the first end of the housing.

[0007] The electrode assembly is housed within the housing;

[0008] The adapter plate is located between the electrode assembly and the groove;

[0009] A cover plate, located between the groove and the first end of the housing, closes the opening; a seal is provided between the housing and the cover plate; and

[0010] The support structure is housed between the electrode assembly and the cover plate, and a gap is provided between the groove and the electrode assembly, with the gap size being not less than 1.5 mm.

[0011] In one embodiment of the present invention, the support structure is located on the pin of the connecting groove of the adapter piece, and the two ends of the support structure form a joint interface with the body of the adapter piece and the pin of the adapter piece, respectively.

[0012] In one embodiment of the present invention, the support structure is located on the body of the adapter plate connecting the electrode assembly, and the two ends of the support structure form a joint interface with the electrode assembly and the body of the adapter plate, respectively.

[0013] In one embodiment of the present invention, the support structure is located on the groove, and the two ends of the support structure form a joint interface with the electrode assembly and the groove, respectively.

[0014] In one embodiment of the present invention, at least one of the joint interfaces at both ends of the support structure is in a connected state, and at most one of the joint interfaces is in an abutting state.

[0015] In one embodiment of the present invention, the two ends of the support structure form a joint interface with the adapter piece and the cover plate respectively, and the joint interface of the support structure at the cover plate end is located in the area outside the explosion-proof valve of the cover plate.

[0016] In one embodiment of this utility model, the joint interface of the support structure at the adapter plate end is a structure integral with the adapter plate formed by welding.

[0017] In one embodiment of this utility model, the joint interface of the support structure at the adapter plate end is snapped into the groove of the adapter plate, and the support structure and the cover plate are an integral structure.

[0018] This utility model also provides a battery pack, including the aforementioned secondary battery.

[0019] The beneficial effects of this invention are as follows: By adding a support structure between the electrode assembly and the cover plate, a stable gap is ensured in the exhaust channel formed within the housing, maintaining pressure relief efficiency under thermal runaway conditions and avoiding the risk of explosion caused by the accumulation of active materials. Furthermore, the added support structure, together with the support of the adapter plate itself, forms a dual support for the electrode assembly, preventing excessive deformation of the adapter plate and ensuring the effectiveness of the exhaust channel. Simultaneously, the modular design of the support structure is compatible with housings manufactured using both grooving and laser welding processes. When used in laser-welded cells, it also avoids the leakage problems that may occur in traditional laser welding processes due to the cover plate and adapter plate penetrating during welding.

[0020] It should be understood that the above general description and the following detailed description are exemplary and explanatory only, and do not limit the present invention. Attached Figure Description

[0021] The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments conforming to the present invention and, together with the description, serve to explain the principles of the present invention. Obviously, the drawings described below are merely some embodiments of the present invention, and those skilled in the art can obtain other drawings based on these drawings without any inventive effort. In the drawings:

[0022] Figure 1 This is a schematic diagram of the structure of the secondary battery of this utility model in the first embodiment;

[0023] Figure 2 This is a schematic diagram of the secondary battery of this utility model in the second embodiment;

[0024] Figure 3 This is a schematic diagram of the structure of the secondary battery of this utility model in the third embodiment;

[0025] Figure 4 This is a schematic diagram of the structure of the secondary battery of this utility model in the fourth embodiment;

[0026] Figure 5 This is a schematic diagram of the structure of the secondary battery of this utility model in the fifth embodiment;

[0027] Figure 6 This is a schematic diagram of the structure of the secondary battery of this utility model in the sixth embodiment;

[0028] Figure 7 This is a schematic diagram of the connection between the support structure and the adapter plate in the secondary battery of this utility model.

[0029] In the diagram: 100, housing; 101, groove; 200, electrode assembly; 300, adapter plate; 301, body; 302, pin; 400, cover plate; 401, explosion-proof valve; 500, support structure. Detailed Implementation

[0030] The following specific examples illustrate the implementation of this utility model. Those skilled in the art can easily understand other advantages and effects of this utility model from the content disclosed in this specification. This utility model can also be implemented or applied through other different specific embodiments, and various details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of this utility model. It should be noted that, in the absence of conflict, the following embodiments and features in the embodiments can be combined with each other. It should also be understood that the terminology used in the embodiments of this utility model is for describing specific implementation schemes and not for limiting the scope of protection of this utility model.

[0031] Please see Figures 1 to 7It should be understood that the structures, proportions, sizes, etc., illustrated in the accompanying drawings are merely for illustrative purposes to aid those skilled in the art and to facilitate understanding. They are not intended to limit the scope of this invention and therefore have no substantial technical significance. Any modifications to the structure, changes in proportions, or adjustments to size, without affecting the effectiveness or purpose of this invention, should still fall within the scope of the technical content disclosed herein. Furthermore, the terms used in this specification regarding position, quantity, etc., are merely for clarity and not intended to limit the scope of this invention. Changes or adjustments to these relative relationships, without substantially altering the technical content, should also be considered within the scope of this invention's implementation.

[0032] The negative electrode adapter plate inside a cylindrical battery is a key structural component of a multi-tab power battery. Current mainstream designs connect the body of the negative electrode adapter plate to the negative electrode tab of the electrode assembly. Multiple pins are arranged circumferentially on the body, and these pins are soldered to grooves to achieve a negative charge on the casing. However, this pin structure is insufficient to support the electrode assembly or maintain spacing between the grooves. Especially during thermal runaway, high-temperature active materials can easily accumulate in the dead zones of the grooves, preventing timely pressure release and increasing the risk of explosion or casing tearing. Furthermore, mechanically pressing the cylindrical battery at its open end causes the portion of the groove near the center of the cylinder to move closer to the electrode assembly, creating dead zones in the groove.

[0033] In light of the above issues, please refer to Figures 1 to 5 This utility model provides a secondary battery, including a housing 100, an electrode assembly 200, an adapter piece 300, a cover plate 400, and a support structure 500; the first end of the housing 100 has an opening, and the inner side wall of the first end of the housing 100 has a groove 101; the electrode assembly 200 is housed in the housing 100; the adapter piece 300 is located between the electrode assembly 200 and the groove 101; the cover plate 400 is located between the groove 101 and the first end of the housing 100 to close the opening, and a sealing element is provided between the housing 100 and the cover plate 400; the support structure 500 is housed between the electrode assembly 200 and the cover plate 400, and a gap is provided between the groove 101 and the electrode assembly 200, and the gap size is not less than 1.5mm.

[0034] Specifically, in this embodiment of the present invention, by providing a support structure 500 between the electrode assembly 200 and the cover plate 400, the adapter piece 300 arranged between the electrode assembly 200 and the groove 101 can still maintain sufficient venting gap between the electrode assembly 200 and the groove 101 on the inner wall of the housing 100 when the adapter piece 300 is deformed by the force of the electrode assembly 200, so that the active material will not be blocked in the dead corner of the groove 101 on the inner wall of the housing 100 when the battery undergoes thermal runaway and pressure relief.

[0035] Furthermore, the support structure 500 can replace the pin 302 structure of the original adapter piece 300. By arranging it at the edge of the adapter piece 300 structure, that is, between the groove 101 formed by the rolling groove of the housing 100 and the electrode assembly 200, or between the housing 100 and the electrode assembly 200 in the laser welding process, it supports and fixes the position of the electrode assembly 200 within the housing 100. This ensures the venting gap between the electrode assembly 200 and the groove 101 formed by the rolling groove of the housing 100, or in the cell structure of the laser welding process, it avoids leakage that may be caused by penetration welding at the cover plate 400 and the adapter piece 300. The support structure 500 can also retain the original structure of the pin 302 of the adapter plate 300, and by setting the support structure 500 on the cover plate 400, the displacement of the electrode assembly 200 under thermal runaway conditions is blocked by the support structure 500 on the cover plate 400, thereby maintaining the positional relationship of the electrode assembly 200 and the adapter plate 300 within the housing 100, and avoiding local blockage caused by the discharge of active material from the electrode assembly 200 during thermal runaway.

[0036] Thus, the support structure 500 ensures a stable gap in the exhaust channel formed within the housing 100, maintaining pressure relief efficiency under thermal runaway conditions, optimizing cell weight loss, and preventing the risk of explosion caused by the accumulation of active materials. Simultaneously, the modular design of the support structure 500 is compatible with housings 100 manufactured using grooving and laser welding processes. Furthermore, the added support structure 500, together with the support of the adapter plate 300 itself, forms a dual support for the electrode assembly 200, providing additional protection under extreme conditions. This prevents excessive deformation of the adapter plate 300 and ensures the effectiveness of the exhaust channel.

[0037] More specifically, the gap between the groove 101 and the electrode assembly 200 is not less than 1.5 mm. That is, after the battery casing 100 is formed and packaged, the distance between the groove 101 and the bottom area of ​​the electrode assembly 200 can be in the range of 2.5 mm to 3.5 mm, and is generally 3 mm (since the plane of the groove 101 is not parallel to the bottom area of ​​the electrode assembly 200, this distance generally refers to the farthest distance from the bottom area of ​​the electrode assembly 200 within the groove 101 area). Correspondingly, the added support structure 500 creates a corresponding gap between the groove 101 and the electrode assembly 200, and limits the gap size to not less than 1.5 mm (the gap size corresponds to the closest distance from the bottom area of ​​the electrode assembly 200 within the groove 101 area). This ensures that, under thermal runaway conditions, the gap size prevents the accumulation of high-temperature active materials in the dead zones of the groove 101, ensuring timely pressure release and reducing the risk of explosion and casing 100 tearing under thermal runaway conditions.

[0038] Please see Figure 1 In one embodiment, the support structure 500 is located on the pin 302 of the connecting groove 101 of the adapter piece 300, and the two ends of the support structure 500 form a joint interface with the body 301 of the adapter piece 300 and the pin 302 of the adapter piece 300, respectively.

[0039] Specifically, in this embodiment of the invention, by optimizing the design of the pin 302 structure of the adapter 300, a support structure 500 is added between the adapter 300 body 301 and the pin 302 structure to improve the battery's safety performance under extreme conditions. The two ends of the support structure 500 form a stable interface with the adapter 300 body 301 and the pin 302, respectively, which not only strengthens the mechanical strength of the traditional pin 302 structure but also solves the problem of easy blockage of the exhaust channel during thermal runaway.

[0040] More specifically, by arranging the support structure 500 between the body 301 and the pin 302 of the adapter 300, the shape of the pin 302 structure of the adapter 300 is reinforced. When the battery cell experiences thermal runaway, the huge displacement force generated by the electrode assembly 200 will be transmitted to the pin 302 structure through the adapter 300. At this time, the support structure 500 can effectively disperse and absorb these stresses, preventing the pin 302 from undergoing plastic deformation or breakage. Furthermore, when the electrode assembly 200 is displaced due to thermal runaway of the battery cell, the support strength of the electrode assembly 200 can be met, maintaining the stability of the pin 302 structure of the adapter 300, thereby ensuring that there is sufficient venting clearance at the groove 101 position of the housing 100 where the pin 302 structure of the adapter 300 is located.

[0041] Furthermore, the introduced support structure 500 transforms the traditional single pin 302 structure into a composite structure with higher rigidity. The dual interface formed by the support structure 500, the adapter plate 300 body 301, and the pins 302 creates a stable force transmission path, enhancing the axial and radial load-bearing capacity of the entire adapter plate 300 assembly. This allows the adapter plate 300 to distribute stress more evenly to the connection points of the housing 100 when subjected to the displacement force of the electrode assembly 200, avoiding premature failure caused by localized stress concentration.

[0042] Thus, the support structure 500 ensures the stability of the venting gap, improving the battery's thermal safety performance. Furthermore, the modular design of the support structure 500 facilitates its application in different battery models. The addition of the support structure 500 does not require changes to the existing production process, providing a reliable solution for enhancing battery thermal safety performance.

[0043] Please see Figure 2In one embodiment, the support structure 500 is located on the body 301 of the electrode assembly 200 connected to the adapter piece 300, and the two ends of the support structure 500 form a joint interface with the electrode assembly 200 and the body 301 of the adapter piece 300, respectively.

[0044] Specifically, in this embodiment of the present invention, by arranging the support structure 500 between the body 301 of the adapter piece 300 and the electrode assembly 200, and with the support structure 500 being symmetrical about the body 301 of the adapter piece 300 and its pin 302 structure, the support structure 500 is located in the area between the groove 101 of the housing 100 and the electrode assembly 200, thereby replacing the support function of the pin 302 structure of the adapter piece 300 and maintaining the gap between the electrode assembly 200 and the groove 101 of the housing 100 to meet the exhaust requirements under thermal runaway conditions.

[0045] More specifically, the two ends of the support structure 500 form a stable mechanical connection with the electrode assembly 200 and the body 301 of the adapter plate 300, respectively. Its symmetrical arrangement places it in the area between the groove 101 of the housing 100 and the electrode assembly 200, thus replacing the support function of the traditional adapter plate 300 pin 302 structure. When the electrode assembly 200 displaces due to thermal runaway, the support structure 500 provides a balanced constraint force, effectively preventing the adapter plate 300 from deflecting or twisting. The direct connection between the support structure 500 and the electrode assembly 200 shortens the force transmission path and significantly improves structural stiffness, ensuring that the exhaust gap between the electrode assembly 200 and the groove 101 of the housing 100 remains stable even under extreme thermal runaway conditions.

[0046] Thus, the support structure 500 ensures a stable exhaust gap to reduce the risk of thermal runaway. The arrangement of the support structure 500 optimizes its force transmission path, thereby extending the structural functional stability.

[0047] Please see Figure 3 In one embodiment, the support structure 500 is located on the groove 101, and the two ends of the support structure 500 form a joint interface with the electrode assembly 200 and the groove 101, respectively.

[0048] Specifically, in this embodiment of the invention, the internal structure of the battery is optimized by directly placing the support structure 500 between the electrode assembly 200 and the groove 101 of the housing 100. The two ends of the support structure 500 form joint interfaces with the electrode assembly 200 and the groove 101, respectively, constructing a mechanical support structure 500 independent of the adapter piece 300. In this case, the function of the adapter piece 300 is simplified to only ensuring electrical connection with the housing 100; its pin 302 structure can be arranged on the lower side of the groove 101 of the housing 100, thereby achieving functional separation of electrical connection and mechanical support. This structural reconfiguration fundamentally solves the performance limitations caused by the adapter piece 300 simultaneously undertaking both conductive and support functions in traditional designs.

[0049] Furthermore, the direct arrangement of the support structure 500, by placing its support points on the direct contact surface between the electrode assembly 200 and the groove 101, creates the shortest force transmission path. When the battery experiences thermal runaway, the enormous expansion force generated by the electrode assembly 200 is directly transmitted to the groove 101 of the housing 100 through the support structure 500, avoiding the drawback of indirect transmission via the pins 302 of the adapter piece 300 in traditional designs. This not only improves the overall rigidity of the structure but also significantly reduces the stress on the adapter piece 300.

[0050] Thus, stable exhaust under extreme operating conditions is ensured by the independently designed support structure 500. Its optimized force transmission path extends the strength performance of the support structure 500, and the simplified functional requirements of the adapter plate 300 reduce manufacturing costs.

[0051] Please see Figures 1 to 3 In one embodiment, at least one of the joint interfaces at both ends of the support structure 500 is in a connected state, and at most one of the joint interfaces is in an abutting state.

[0052] Specifically, in this embodiment of the invention, the support structure 500 is used to enhance the support strength of the adapter plate 300 for the electrode assembly 200, thereby ensuring structural stability under the force of the electrode assembly 200 during thermal runaway. During the assembly of the adapter plate 300 into the housing 100 to form an electrical connection with the electrode assembly 200, and during the process of forming the groove 101 through the grooving process of the housing 100, there is a tendency for relative displacement caused by deformation between the adapter plate 300 and the housing 100, and between the adapter plate 300 and the electrode assembly 200 and the housing 100 at the contact points during thermal runaway. At this time, by ensuring that one side of the joint interface between the arranged support structure 500 and the electrode assembly 200, the adapter plate 300, or the groove 101 is a fixed connection and the other side is an abutment, a margin is provided for the relative displacement caused by the deformation of the adapter plate 300, maintaining the structural integrity of the adapter plate 300 and avoiding affecting the exhaust gap space between them.

[0053] More specifically, the fixed connection end of the support structure 500 is typically rigidly connected to the body 301 of the adapter piece 300 or the groove 101 of the housing 100, and permanent fixation can be achieved using processes such as laser welding, riveting, or integral molding. The movable abutment end maintains a relatively sliding contact relationship with the electrode assembly 200 or other structural components. This design fully considers the various deformation requirements of the battery components during assembly and use. When the battery undergoes the groove 101 forming process in the housing 100, assembly stress will be generated between the adapter piece 300 and the housing 100; under thermal runaway conditions, the expansion of the electrode assembly 200 will cause additional displacement tendencies. At this time, the abutment design of the movable end of the support structure 500 can effectively absorb these deformation displacements, preventing the structural components from undergoing plastic deformation or fracture due to over-constraint.

[0054] Furthermore, by employing connection methods with different joint interfaces, the fixed connection end ensures the basic positioning and main load-bearing function of the support structure 500, while the movable abutment end enables the structure to adapt to necessary deformation. In the event of thermal runaway, the expansion force of the electrode assembly 200 is first transmitted to the support structure 500 through the abutment interface. As the displacement increases, the abutment interface gradually transforms into a tight contact state, ultimately forming a complete force transmission path. This progressive force characteristic ensures deformation buffering in the initial stage while providing sufficient support strength under extreme conditions.

[0055] Furthermore, the abutment end of the support structure 500 is designed with reserved deformation compensation space to ensure that the adapter plate 300 will not exert a squeezing effect on the exhaust channel when it is displaced. At the same time, the presence of the fixed connection end prevents the overall displacement of the support structure 500 and provides a reference positioning for the exhaust gap. This effectively ensures the smooth discharge of active materials in the electrode assembly 200 under thermal runaway conditions. Moreover, the two types of joint interfaces, fixed connection and abutment, have good implementation convenience. The fixed connection end can use mature connection technology to ensure connection reliability; the movable abutment end achieves the designed gap through size control and requires no additional process.

[0056] Thus, by employing different joint interface designs, structural integrity and venting smoothness are ensured during thermal runaway. The relatively movable joint between the fixed end and the abutting end enhances the strength of the support structure 500. Furthermore, the abutting joint interface design reduces manufacturing costs. The single-sided fixed joint also facilitates the inspection and replacement of the support structure 500.

[0057] Please see Figures 4 to 6 In one embodiment, the two ends of the support structure 500 form a joint interface with the adapter piece 300 and the cover plate 400, respectively, and the joint interface of the support structure 500 at the end of the cover plate 400 is located in the area outside the explosion-proof valve 401 of the cover plate 400.

[0058] Specifically, in this embodiment of the invention, the support structure 500 is arranged between the cover plate 400 and the adapter plate 300 to replace the support provided by the pin 302 structure of the adapter plate 300 at the location of the groove 101 formed by the grooving in the housing 100. Furthermore, the cover plate 400 serves as the base point of the bottom of the support structure 500, providing higher structural strength compared to the groove 101 location, thereby ensuring the support structure 500's support for the electrode assembly 200 under thermal runaway conditions. Simultaneously, the explosion-proof valve 401 on the cover plate 400 will open under pressure during thermal runaway, thus excluding the location where the support structure 500 is connected to the cover plate 400 from the area of ​​the explosion-proof valve 401.

[0059] More specifically, by using the cover plate 400 as the pressure-bearing component of the electrode assembly 200, its structural strength and stiffness are far superior to those of the groove 101 section of the housing 100. The support structure 500, with the cover plate 400 as a fixed reference, can establish a more stable force transmission path. Under thermal runaway conditions, when the electrode assembly 200 generates enormous expansion force, the support structure 500 directly transmits the load to the cover plate 400 via the adapter plate 300, avoiding the deformation amplification effect caused by indirect force transmission through the groove 101 of the housing 100 in traditional designs. This effectively resists the impact load caused by the displacement of the electrode assembly 200.

[0060] Furthermore, the connection point of the support structure 500 on the cover plate 400 avoids the working area of ​​the explosion-proof valve 401, ensuring that the normal function of the explosion-proof valve 401 is not affected. When the internal pressure of the battery reaches a critical value, the explosion-proof valve 401 can open and release pressure without obstruction. The presence of the support structure 500 not only does not interfere with this process, but also creates more favorable conditions for the pressure release process by maintaining the venting gap between the electrode assembly 200 and the housing 100. In this way, the thermal runaway protection capability is improved by optimizing the force transmission path of the support structure 500, and the structural stability for long-term use is ensured by utilizing the robust cover plate 400 reference.

[0061] Please see Figures 4 to 7 In one embodiment, the interface between the support structure 500 and the adapter piece 300 is formed by welding, making it an integral structure with the adapter piece 300.

[0062] Specifically, in this embodiment of the invention, the support structure 500 is integrated into a single structure at the interface of the adapter piece 300 using a welding process, replacing the traditional pin 302 structure of the adapter piece 300. This connection method not only improves its structural strength but also solves the problem of dimensional fluctuations in the traditional split design. The support structure 500 can be permanently connected to the body 301 of the adapter piece 300 by welding, forming an integrated mechanical transmission structure to demonstrate its stability under thermal runaway conditions.

[0063] For more specific details, please refer to Figure 5 Alternatively, the pin 302 structure of the original negative electrode adapter 300 can be eliminated, and a support structure 500 can be introduced between the cover plate 400 and the negative electrode adapter 300. This support structure 500 can be welded to the negative electrode adapter 300 to form an integral structure (this can be applied to both grooved and laser-welded battery cells). Please refer to [link to relevant documentation]. Figure 6 When the support structure 500 is applied to the cell using laser welding process, there is no need to form the groove 101 structure on its housing 100. By limiting the welding area between the support structure 500 and the adapter plate 300, and by avoiding the intersection of the welding heat-affected zone and the key sealing area, the potential for electrolyte leakage caused by welding is fundamentally eliminated. This solves the leakage problem that may be caused by the penetration welding of the cover plate 400 and the adapter plate 300 in the traditional laser welding process.

[0064] Thus, the welded connection with an integrated structure eliminates the gaps and stress concentration problems inherent in traditional mechanical connections, creating a continuous material transition between the support structure 500 and the adapter plate 300. In the event of thermal runaway, the expansion force of the electrode assembly 200 can be uniformly transmitted through this integrated structure, avoiding the localized plastic deformation common in traditional pin 302 designs, and maintaining a stable exhaust gap even under extreme conditions. Therefore, the integrated support structure 500 ensures stable support under extreme thermal runaway conditions.

[0065] Please see Figures 4 to 7 In one embodiment, the interface between the support structure 500 and the adapter plate 300 is engaged in the groove of the adapter plate 300 by snapping it in. The support structure 500 and the cover plate 400 are an integral structure.

[0066] Specifically, in this embodiment of the present invention, a support structure 500 is introduced on the cover plate 400. The support structure 500 and the cover plate 400 are designed as a single unit. The support structure 500 is engaged by the groove of the adapter piece 300. When the battery cell experiences thermal runaway, the electrode assembly 200 is squeezed towards the explosion-proof valve 401. The presence of the support structure 500 on the cover plate 400 ensures the exhaust gap between the electrode assembly 200 and the groove 101 of the housing 100, eliminating exhaust dead angles and avoiding the problem of battery cell safety caused by excessive accumulation of substances in exhaust dead angles.

[0067] More specifically, by employing a snap-fit ​​support structure 500 to connect the adapter plate 300, and making the support structure 500 and the cover plate 400 an integral structure, the connection strength and dimensional accuracy between them are ensured, eliminating the assembly errors present in traditional split structures. Furthermore, the snap-fit ​​mechanism and the groove of the adapter plate 300 form a reliable constraint. When the electrode assembly 200 displaces under thermal runaway conditions, this snap-fit ​​structure can efficiently transfer the force to the robust cover plate 400, while maintaining the relative position of the adapter plate 300 to ensure a stable exhaust gap.

[0068] In one embodiment, the support structure 500 has an elastic deformation allowance.

[0069] Specifically, in this embodiment of the invention, by employing an elastic support structure 500, a certain dimensional allowance for elastic deformation is provided while ensuring support strength. This addresses the issue of dimensional tolerance accumulation between the cover plate 400 and the adapter piece 300 during battery assembly, thereby improving product yield and reliability. This material characteristic enables it to maintain stable elastic deformation when subjected to the force of the electrode assembly 200, without undergoing plastic deformation.

[0070] More specifically, its elastic properties allow for automatic compensation of dimensional deviations between components during assembly, thereby reducing the traditionally required precision control of assembly tolerances. During battery assembly, the support structure 500 automatically adapts to the positional changes of the adapter piece 300 through elastic deformation, ensuring uniform pressure distribution on the contact surface. This adaptive characteristic eliminates the need for complex adjustment procedures during assembly, shortening single-piece assembly time and improving production line yield. Furthermore, its design is fully compatible with existing automated assembly equipment, eliminating the need for additional, expensive precision positioning systems.

[0071] Thus, by employing the flexible support structure 500, the requirements for assembly precision and production costs can be reduced. It also provides more reliable support protection and thermal safety performance. Simultaneously, the flexible structure has better fatigue resistance, extending the service life of the support structure 500 and facilitating adaptation to different battery sizes.

[0072] This utility model also provides a battery pack, including the aforementioned secondary batteries. Specifically, the battery pack integrates multiple of the aforementioned secondary batteries to construct a battery system with high safety and reliability. In each secondary battery of the battery pack, its independent support structure 500 ensures individual structural safety. In the event of thermal runaway in a single battery, the battery's own support structure 500 ensures unobstructed venting, confining the thermal runaway within a single module and effectively preventing a chain reaction.

[0073] In summary, the secondary battery and battery pack provided by this utility model, through the addition of a support structure between the electrode assembly and the cover plate, ensures a stable gap in the exhaust channel formed within the casing, maintains pressure relief efficiency under thermal runaway conditions, optimizes cell weight loss, and avoids the risk of explosion caused by the accumulation of active materials. Simultaneously, the modular design of the support structure is compatible with casings manufactured using grooving and laser welding processes. Furthermore, the added support structure, together with the support of the adapter plate itself, forms a dual support for the electrode assembly, preventing excessive deformation of the adapter plate and ensuring the effectiveness of the exhaust channel.

[0074] The above embodiments are merely illustrative of the principles and effects of this utility model and are not intended to limit the scope of this utility model. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this utility model. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this utility model should still be covered by the claims of this utility model.

Claims

1. A secondary battery, characterized in that, include: The housing has an opening at its first end and a groove on the inner side wall of the first end of the housing. The electrode assembly is housed within the housing; The adapter piece is located between the electrode assembly and the groove; A cover plate is located between the groove and the first end of the housing to close the opening, and a sealing element is provided between the housing and the cover plate; as well as A support structure is housed between the electrode assembly and the cover plate, and a gap is provided between the groove and the electrode assembly, wherein the gap dimension is not less than 1.5 mm.

2. The secondary battery according to claim 1, characterized in that, The support structure is located on the pin of the adapter piece that connects to the groove, and the two ends of the support structure form a joint interface with the body of the adapter piece and the pin of the adapter piece, respectively.

3. The secondary battery according to claim 1, characterized in that, The support structure is located on the body of the adapter piece connecting the electrode assembly, and the two ends of the support structure form a joint interface with the electrode assembly and the body of the adapter piece, respectively.

4. The secondary battery according to claim 1, characterized in that, The support structure is located on the groove, and the two ends of the support structure form a joint interface with the electrode assembly and the groove, respectively.

5. The secondary battery according to any one of claims 2-4, characterized in that, At least one of the joint interfaces at both ends of the support structure is in a connected state, and at most one of the joint interfaces is in an abutting state.

6. The secondary battery according to claim 1, characterized in that, The two ends of the support structure form joint interfaces with the adapter piece and the cover plate, respectively, and the joint interface of the support structure at the cover plate end is located in the area outside the explosion-proof valve of the cover plate.

7. The secondary battery according to claim 6, characterized in that, The support structure is integral with the adapter piece at the interface of the adapter piece formed by welding.

8. The secondary battery according to claim 6, characterized in that, The support structure is engaged in the groove of the adapter plate at the interface of the adapter plate by snapping it in. The support structure and the cover plate are an integral structure.

9. The secondary battery according to claim 1, characterized in that, The support structure has an elastic deformation allowance.

10. A battery pack, characterized in that, Includes the secondary battery as described in any one of claims 1-9.

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