Lithium ion cell and power battery

Abstract

The invention provides a lithium ion battery cell and a power battery, and belongs to the technical field of power battery, the lithium ion battery cell comprises a naked battery cell, a top cover and a shell, the top cover and the shell enclose to form a containing cavity, the top cover comprises a top cover main body provided with a pole structure, the pole column structure comprises a positive pole column structure and a negative pole column structure which are correspondingly and electrically connected with a positive pole piece on a naked battery cell; the pole structure comprises a tenon part and a mortise structure, the tenon part can be connected with an external busbar, the mortise structure penetrates through the top cover main body, the mortise structure comprises a bottom plate and a side wall, the bottom plate can be connected with a positive pole piece or a negative pole piece on a naked battery cell, and the periphery of the side wall is in sealed connection with the top cover main body; and the tenon part and the mortise structure are matched to form detachable connection. The tenon part is connected with the external busbar, and the tenon part is matched with the mortise structure to form detachable mechanical connection, so that the pole structure can be detached as required, the external busbar does not need to be replaced, and maintenance and replacement are facilitated.

Description

Technical Field

[0001] The present application relates to the technical field of power batteries, and in particular to a lithium-ion battery cell and a power battery. Background Art

[0002] Power batteries refer to power sources that provide power for vehicles. Currently, they mainly refer to batteries on new energy vehicles, and lithium-ion cells are the basic units that constitute power batteries, generally lithium-ion batteries. Power batteries can be composed of multiple lithium-ion cells in series and parallel to meet the needs of high voltage and large capacity. In order to provide sufficient voltage and capacity to drive electric vehicles, multiple cells need to be combined into modules or CTP battery packs. In the process of assembling lithium-ion cells to form battery modules or CTP battery packs, welding is generally used to arrange and combine the individual cells in series, parallel, or series-parallel parallel through busbars to connect and fix them to each other, so as to ensure the electrical connection stability and normal use of the module or battery pack.

[0003] However, since multiple lithium-ion battery cells are fixedly connected to a busbar by welding to form a module or battery pack, when one or more battery cells in the module or battery pack are damaged and the module or battery pack cannot be used, the entire module or battery pack needs to be disassembled and repaired, and the busbar and abnormal battery cells need to be replaced, which reduces the maintenance convenience of the module or battery pack and increases the maintenance cost. Summary of the invention

[0004] The present application provides a lithium-ion battery cell and a power battery to solve the problems of reduced maintenance convenience and high maintenance cost of current modules or battery packs.

[0005] In a first aspect, the present application provides a lithium-ion battery cell, comprising: a bare battery cell, a top cover and a shell, wherein the top cover and the shell are combined to form a accommodating cavity, and the bare battery cell is located in the accommodating cavity; the top cover comprises a top cover body, and a pole structure is arranged on the top cover body; the pole structure comprises a tenon head and a tenon groove structure, the tenon groove structure runs through the top cover body, and the tenon head and the tenon groove structure cooperate to form a detachable connection.

[0006] Through the above scheme, the top cover and the shell together constitute the external structure of the lithium-ion battery cell, which encloses a cavity for accommodating the bare battery cell. Since the tenon head is connected to the external busbar, the lithium-ion battery cell can be integrated into the battery module or battery pack, and the tenon head cooperates with the tenon groove structure to form a detachable mechanical connection. This design allows the pole structure to be disassembled when necessary, which is convenient for maintenance and replacement. Improve maintenance efficiency and reduce maintenance costs.

[0007] In a possible design, the tenon portion includes a welding portion and a flange portion connected to the welding portion, the welding portion can form a welding connection with the external busbar, and the flange portion can cooperate to extend into the interior of the tenon and groove structure to form a detachable connection.

[0008] Through the above solution, the welding part is a part of the tenon head, which is designed to be welded to the external busbar, so that the connection between the welding part and the external busbar provides a stable electrical connection. The flange part is another part of the tenon head, which is connected to the welding part and can extend into the interior of the tenon groove structure. The cooperation between the flange part and the tenon groove structure can ensure that the flange part can smoothly extend and form a detachable connection, which is convenient for disassembling the pole structure when necessary, so that the battery cell can be maintained and replaced.

[0009] In a possible design, the tongue and groove structure includes an elastic portion, which is fixedly disposed within the tongue and groove structure, and the flange portion can be clamped within the elastic portion to form a detachable connection with the elastic portion.

[0010] Through the above solution, an elastic part is arranged in the tongue-and-groove structure, so that the flange part can be stuck in the elastic part to form a detachable connection, and the outer periphery of the side wall of the tongue-and-groove structure forms a sealing connection with the top cover body, so that the tongue-and-groove structure can achieve a sealing effect with the top cover and a detachable connection with the flange part at the same time. This design makes the top cover as a whole firm and reliable, and also has a certain degree of flexibility and detachability, which is convenient for maintenance and replacement.

[0011] In a possible design, the elastic part includes a bottom substrate, a movable waist plate and a clamping plate, the movable waist plate is fixedly arranged along the outer periphery of the bottom substrate to form a mortise, the shape of the mortise matches the shape of the flange part; the flange part has an insertion end and a clamping end away from the insertion end, and the cross-sectional diameter of the flange part gradually increases along the direction from the clamping end to the insertion end; the cross-sectional diameter of the mortise gradually increases along the direction from the entrance of the mortise to the bottom substrate; the flange part is inserted along the entrance of the mortise in the direction of the bottom substrate, and when the flange part is inserted into the mortise, the clamping end of the mortise is clamped by the entrance of the mortise.

[0012] Through the above scheme, the flange portion has an insertion end and a clamping end, the insertion end is used to insert into the mortise, and the clamping end is used to form a clamping connection with the clamping plate of the mortise. The cross-sectional diameter of the mortise gradually increases from the entrance to the bottom substrate, matching the change in the cross-sectional diameter of the flange portion, so that the flange portion can be gradually "locked" in the mortise when inserted into the mortise. This self-locking mechanism ensures the stability of the connection and prevents the flange portion from accidentally falling off due to vibration or impact. The flange portion is inserted into the bottom substrate along the entrance of the mortise, and when the flange portion is inserted into the mortise, the clamping end of the mortise is clamped by the entrance of the mortise to achieve clamping. This clamping method provides a secure connection while allowing the flange portion to be disassembled by appropriate operation when necessary.

[0013] In a possible design, the insertion end is provided with an inclined surface, and the inclined surface enables the flange portion to be inserted from the entrance of the mortise.

[0014] Through the above scheme, when the flange is inserted into the mortise, the inclined surface first contacts the side wall of the mortise. Due to the design of the inclined surface, this can reduce the force required for insertion, making the entire insertion process smoother. The presence of the inclined surface also helps to guide the flange to correctly align with the mortise, reducing the risk of misalignment or jamming. Even if the cross-sectional diameter of the flange gradually increases from the clamping end to the insertion end, the design of the inclined surface allows the flange to be easily inserted in the initial stage. Once passing through the inclined surface part, the increase in the diameter of the flange will cause it to be clamped in the mortise, achieving self-locking. The design of the insertion end being provided with an inclined surface balances the convenience of insertion and the stability of the connection.

[0015] In one possible design, the clip plate is fixed at the entrance of the mortise, the clip plate is fixed on the outside of the mortise and extends toward the mortise structure, or the clip plate is fixed on the inside of the mortise and extends away from the mortise structure.

[0016] Through the above solution, the clamping plate is fixed on the outside of the mortise and extends in the direction of the mortise structure. In this design, when the flange is inserted into the mortise, its clamping end will contact and be clamped with the clamping plate. Since the clamping plate extends in the direction of the mortise structure, it forms a barrier on the outside of the mortise to prevent the flange from falling out of the mortise. The clamping plate provides additional support on the outside of the mortise, enhancing the stability of the connection.

[0017] The clamping plate is fixed on the inner side of the mortise and extends in the direction away from the mortise structure. In this design, after the clamping end of the flange is inserted into the mortise, the clamping end will be clamped by the clamping plate. The clamping plate forms a reverse block on the inner side of the mortise, so that the flange cannot easily escape from the mortise. The design of the clamping plate on the inner side of the mortise makes the overall structure more compact, reduces the external protruding part, and is more suitable for applications with limited space.

[0018] Each of these two methods of fixing the card plate has its own advantages, and which one to choose depends on the specific application requirements and design considerations. The first method may be more suitable for scenarios that require higher stability and easy operation, while the second method may be more suitable for applications with limited space or requiring a concealed card connection mechanism. The appropriate method of fixing the card plate can be selected based on factors such as the specific use environment of the battery cell, maintenance requirements, and manufacturing costs.

[0019] In a possible design, conductive glue is provided between the flange portion and the movable waist plate.

[0020] According to the above scheme, the conductive adhesive is an adhesive with certain conductive properties after curing or drying, mainly composed of a base resin and a conductive filler (such as metal powder). The conductive particles are combined together by the bonding effect of the base resin to form a conductive path to achieve conductive connection of the bonded materials. By arranging the conductive adhesive between the flange and the movable waist plate, not only a stable conductive connection can be achieved, but also good mechanical bonding performance can be provided.

[0021] In one possible design, the pole structure includes a positive pole structure for electrically connecting to the positive pole piece on the bare battery cell and a negative pole structure for electrically connecting to the negative pole piece on the bare battery cell; the mortise and tenon structure includes a bottom plate and a side wall, the bottom plate can be connected to the positive pole piece or the negative pole piece on the bare battery cell, and the outer periphery of the side wall forms a sealed connection with the top cover body.

[0022] Through the above scheme, the pole structure on the top cover includes a positive pole structure and a negative pole structure, the positive pole structure and the negative pole structure are electrically connected to the positive pole sheet and the negative pole sheet on the bare battery cell respectively, and the sealed connection between the side wall and the top cover body helps to protect the interior of the battery cell from being affected by the external environment.

[0023] In a possible design, the top cover further includes an upper plastic, a lower plastic and a sealing ring; the upper plastic is disposed above the outer periphery of the side wall of the tongue and groove portion, the lower plastic is disposed below the outer periphery of the side wall of the tongue and groove portion, and the sealing ring is disposed between the upper plastic and the lower plastic. The top cover further includes an explosion-proof structure and a sealing member, which are disposed on the main body of the top cover.

[0024] Through the above solution, the upper plastic, lower plastic and sealing ring together constitute the sealing structure of the battery top cover, which can effectively protect the electrical components inside the battery and extend the service life of the battery. The design of the sealing structure needs to take into account the sealing requirements of the battery in different use environments, including factors such as temperature changes, pressure changes and chemical corrosion.

[0025] The explosion-proof structure is an important part of battery safety design. When the pressure inside the battery increases due to abnormal conditions, the explosion-proof structure can be opened in time to release the internal pressure and prevent the battery from exploding, thereby protecting the safety of the battery and the surrounding environment. The injection hole is a channel for injecting electrolyte during the battery manufacturing process. After the injection is completed, it is necessary to ensure the sealing of the injection hole to prevent electrolyte leakage and the intrusion of external contaminants. The seal design can prevent the generation of metal particles and burrs, which may fall into the battery and cause a short circuit. The use of seals can ensure the cleanliness of the inside of the battery and improve the reliability and safety of the battery.

[0026] In a second aspect, the present application provides a power battery, comprising a busbar and any of the above-mentioned lithium-ion battery cells, wherein the tenon head can be connected to the busbar so that the lithium-ion battery cell is connected to the busbar.

[0027] The beneficial effects of the power battery provided in the second aspect and each possible design of the second aspect can be referred to the beneficial effects brought about by the first aspect and each possible implementation method of the first aspect, which will not be repeated here.

[0028] The above description is only an overview of the technical solution of the embodiment of the present application. In order to more clearly understand the technical means of the embodiment of the present application, it can be implemented in accordance with the contents of the specification. In order to make the above and other purposes, features and advantages of the embodiment of the present application more obvious and easy to understand, the specific implementation methods of the present application are listed below. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the present application, a brief introduction will be given below to the drawings required for use in the description of the embodiments. Obviously, the drawings described below are some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0030] Figure 1 Schematic diagram of a lithium-ion battery cell provided in one embodiment of the present application.

[0031] Figure 2 An exploded view of a lithium-ion battery cell provided in one embodiment of the present application.

[0032] Figure 3 Schematic diagram of a top cover of a lithium-ion battery cell provided in one embodiment of the present application.

[0033] Figure 4 for Figure 3 A cross-sectional view of the top cover of the lithium-ion battery cell provided in the figure along the A-A1 direction.

[0034] Figure 5 for Figure 3 A partial enlarged view of the D area in the middle.

[0035] Figure 6 This is a schematic diagram of an elastic portion provided in an embodiment of the present application.

[0036] Figure 7 for Figure 6 A schematic diagram of the elastic portion from another perspective is provided.

[0037] Figure 8 for Figure 7 A cross-sectional view of the elastic portion along the B-B1 direction is provided.

[0038] Fig. 9 This is a schematic diagram of an elastic portion provided in another embodiment of the present application.

[0039] Fig.10 for Fig. 9 A schematic diagram of the elastic portion from another perspective is provided.

[0040] Fig.11 for Fig.10 A cross-sectional view of the elastic portion along the C-C1 direction is provided.

[0041] Explanation of the reference numerals: 100, top cover body; 110, upper plastic; 120, lower plastic; 130, explosion-proof structure; 140, seal; 150, sealing ring; 200, shell; 201, bare battery cell; 202, pole ear; 203, insulating member; 210, connecting piece; 300, pole structure; 310, tenon head; 320, tenon and groove structure; 321, bottom plate; 322, side wall; 311, welding part; 312, flange part; 313, inclined plane; 330, elastic part; 331, bottom substrate; 332, movable waist plate; 333, snap-in plate; D area; section line A-A1; section line B-B1; section line C-C1. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the embodiments of the present application clearer, the technical solution in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0043] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by technicians in the technical field to which this application belongs; the terms used in the specification of the application are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification, claims and drawings of this application are intended to cover non-exclusive inclusions.

[0044] Reference to "embodiments" herein means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase "embodiments" in various locations in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. It is explicitly and implicitly understood by those skilled in the art that the embodiments described herein may be combined with other embodiments.

[0045] The term "and / or" in this article is only a description of the association relationship of the associated objects, indicating that there can be three relationships. For example, A and / or B can mean: A exists, A and B exist at the same time, and B exists. In addition, the character " / " in this article generally indicates that the associated objects before and after are in an "or" relationship.

[0046] The directional words appearing in the following description are all directions shown in the figures, and do not limit the specific structure of the lithium-ion battery cell of the present application. For example, in the description of the present application, the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the drawings, which are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction, and therefore cannot be understood as a limitation on the present application.

[0047] In addition, the terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order, and may explicitly or implicitly include one or more of the features.

[0048] In the description of the present application, unless otherwise specified, "plurality" means more than two (including two), and similarly, "multiple groups" means more than two groups (including two).

[0049] In the description of the present application, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected" and "connected" should be understood in a broad sense. For example, the "connection" or "connection" of a mechanical structure may refer to a physical connection. For example, the physical connection may be a fixed connection, such as a fixed connection through a barrier, such as a fixed connection through screws, bolts or other barrier; the physical connection may also be a detachable connection, such as a mutual snap-on or snap-fit ​​connection; the physical connection may also be an integral connection, such as a connection formed by welding, bonding or integral molding. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0050] Power batteries are made of lithium-ion cells (hereinafter referred to as cells) as basic units, which are combined into modules through different series and parallel methods, and then composed of multiple modules plus battery management systems to form a battery pack, which is finally installed in electric vehicles to provide power. Cells are the core components of power batteries and determine the core performance of batteries such as energy density, power performance, safety and life.

[0051] As the core component of new energy vehicles, power batteries are generally welded to arrange and combine individual cells in series, parallel or series-parallel through busbars during the process of assembling lithium-ion cells to form modules or CTP battery packs, so as to ensure the electrical connection stability and normal use of the modules or battery packs. However, when a module or battery pack is formed by arranging and combining multiple lithium-ion cells together by welding, if one or more cells are damaged or unusable, the entire module or battery pack needs to be disassembled and the busbar and abnormal cells need to be replaced, which reduces the convenience of battery maintenance and increases maintenance costs.

[0052] In view of this, the present application provides a lithium-ion battery cell and a power battery, wherein the pole structure in the top cover of the lithium-ion battery cell is designed to be a detachable mechanical connection including a tenon head and a tenon groove structure, so that the pole structure of the lithium-ion battery cell can be disassembled when necessary, which is convenient for maintenance and replacement, thereby improving maintenance efficiency and reducing maintenance costs.

[0053] Figure 1 Schematic diagram of a lithium-ion battery cell provided in one embodiment of the present application. Figure 2 This is a schematic diagram of an exploded view of a lithium-ion battery cell provided in one embodiment of the present application. Figure 3 Schematic diagram of a top cover of a lithium-ion battery cell provided in one embodiment of the present application. Figure 4 for Figure 3 The cross-sectional view of the top cover of the lithium-ion battery cell along the A-A1 direction is provided in. Please refer to Figures 1 to 4 In this embodiment, a lithium-ion battery cell is provided, including: a bare battery cell 201, a top cover and a shell 200. The top cover and the shell 200 are enclosed to form a receiving cavity, and the bare battery cell 201 is located in the receiving cavity.

[0054] Please refer to Figure 1 The bare cell 201 is a basic component of the cell, including a positive electrode sheet, a negative electrode sheet, and an electrolyte and a separator between the positive electrode sheet and the negative electrode sheet.

[0055] The bare cell 201 in this embodiment is formed by stacking and winding the positive electrode sheet, the negative electrode sheet and the isolation film around the central axis, and the pole ear 202 extends from the top of the bare cell 201, and the pole ear 202 is electrically connected to the connecting piece 210 by welding. The number of bare cells 201 in the accommodating cavity is at least one, and multiple bare cells 201 are connected to the connecting piece 210, and then the connecting piece 210 is electrically connected to the pole in the top cover. An insulating member 203 is provided on the outside of the bare cell 201, and the bare cell 201 is wrapped by the insulating member 203, so that the bare cell 201 is insulated from the outer shell to avoid contact between the bare cell 201 and the outer shell to cause a short circuit of the cell.

[0056] The top cover and the shell 200 together constitute the external structure of the battery cell, and they enclose to form a receiving cavity for accommodating the bare battery cell 201 .

[0057] The shell 200 is designed as a cavity structure with an opening on the top, so that the bare battery 201 can be wrapped inside the shell 200. By closing the top cover on the shell 200 and sealing it with the top cover, the bare battery 201 is isolated from the outside world or the bare battery 201 is prevented from contacting the external environment and causing failure of the bare battery 201.

[0058] The top cover includes a top cover body 100, on which a pole structure 300 is arranged, the pole structure 300 includes a positive pole structure 300 for electrically connecting to the positive pole piece on the bare battery cell 201 and a negative pole structure 300 for connecting to the negative pole piece on the bare battery cell 201; the pole structure 300 includes a tenon portion 310 and a tenon-groove structure 320, the tenon portion 310 can be connected to an external busbar (not shown), the tenon-groove structure 320 is arranged throughout the top cover body 100, the tenon-groove structure 320 includes a bottom plate 321 and a side wall 322, the bottom plate 321 can be connected to the positive pole piece or the negative pole piece on the bare battery cell 201, the outer periphery of the side wall 322 forms a sealed connection with the top cover body 100, and the tenon portion 310 cooperates with the tenon-groove structure 320 to form a detachable connection.

[0059] Through the above scheme, the top cover and the shell 200 together constitute the external structure of the lithium-ion battery cell. They enclose to form a receiving cavity for receiving the bare battery cell 201. The pole structure 300 on the top cover includes a positive pole structure 300 and a negative pole structure 300. The positive pole structure 300 and the negative pole structure 300 are electrically connected to the positive pole piece and the negative pole piece on the bare battery cell 201, respectively. The sealed connection between the side wall 322 and the top cover body 100 helps to protect the inside of the battery cell from the external environment. Since the tenon head 310 is connected to the external busbar, the lithium-ion battery cell can be integrated into the battery module or battery pack, and the tenon head 310 cooperates with the tongue and groove structure 320 to form a detachable mechanical connection. This design allows the pole structure 300 to be disassembled when necessary, which is convenient for maintenance and replacement. When one or more cells in a module or battery pack are damaged and the module or battery pack cannot be used, there is no need to replace the busbar. Instead, the tenon head 310 and the tenon groove structure 320 need only be separated to replace the corresponding broken lithium-ion cells, thereby improving the maintenance convenience of the module or battery pack and reducing maintenance costs.

[0060] In this embodiment, the tenon portion 310 includes a welding portion 311 and a flange portion 312 connected to the welding portion 311. The welding portion 311 can form a welding connection with the external busbar, and the flange portion 312 can cooperate to extend into the interior of the tenon structure 320 to form a detachable connection. The welding portion 311 realizes a stable connection between the battery cell and the external busbar, and the design of the flange portion 312 realizes the detachable connection with the bare battery cell 201.

[0061] The welding part 311 is welded to the external busbar, so that the connection between the welding part 311 and the external busbar provides a stable electrical connection. The welding connection method can be laser welding, ultrasonic welding or resistance welding, etc. The specific method can depend on the corresponding welding technology in the battery cell manufacturing process.

[0062] The flange portion 312 is another part of the tenon portion 310, one end of which is fixed to the welding portion 311, and the other end is able to extend into the interior of the tenon structure 320. The cooperation between the flange portion 312 and the tenon structure 320 can ensure that the flange portion 312 can be smoothly extended and form a detachable connection, which is convenient for disassembling the pole structure 300 when necessary, so that the battery cell can be maintained and replaced.

[0063] In some embodiments, the flange portion 312 may be configured to be elastically designed so as to provide a certain degree of flexibility in the connection and disassembly process. The elastic design of the flange portion 312 may be a structural design that sets the structure of the flange portion 312 to be able to cooperate with the tongue and groove structure 320 and to be able to be stuck in the tongue and groove structure 320 and has a rebound effect.

[0064] In some embodiments, the flange portion 312 may also include an elastic structural member sleeved on the outer periphery of the flange portion, and the elastic structural member is a structural design with a rebound effect that can be inserted into and stuck in the tenon structure 320, so that the pole structure 300 can be easily disassembled, thereby maintaining and replacing the battery cell.

[0065] Figure 5 for Figure 3 A partial enlarged view of the D area in the middle. Please refer to Figure 5 An elastic portion 330 is provided in the mortise and tenon structure 320 , and the elastic portion 330 is fixed inside the mortise and tenon structure 320 . The flange portion 312 can be stuck inside the elastic portion 330 to form a detachable connection with the elastic portion 330 .

[0066] Through the above solution, the elastic part 330 is arranged in the tongue-and-groove structure 320, so that the flange part 312 can be stuck in the elastic part 330 to form a detachable connection, and the outer periphery of the side wall 322 of the tongue-and-groove structure 320 forms a sealing connection with the top cover body 100, so that the tongue-and-groove structure 320 can achieve a sealing effect with the top cover, and at the same time can achieve a detachable connection with the flange part 312. This design makes the top cover as a whole firm and reliable, and also has a certain degree of flexibility and detachability, which is convenient for maintenance and replacement.

[0067] Please continue to refer to Figure 5 In this embodiment, the elastic part 330 includes a bottom substrate 331, a movable waist plate 332 and a clamping plate 333. The movable waist plate 332 is fixedly arranged along the outer periphery of the bottom substrate 331 to form a mortise. The shape of the mortise matches the shape of the flange part 312. The flange part 312 has an insertion end and a clamping end away from the insertion end. The cross-sectional diameter of the flange part 312 gradually increases in the direction from the clamping end to the insertion end. The cross-sectional diameter of the mortise gradually increases in the direction from the entrance of the mortise to the bottom substrate 331. The flange part 312 is inserted into the direction of the bottom substrate 331 along the entrance of the mortise. When the flange part 312 is inserted into the mortise, the clamping end of the mortise is clamped by the entrance of the mortise.

[0068] Through the above scheme, the flange portion 312 has an insertion end and a clamping end, the insertion end is used to insert into the mortise, and the clamping end is used to form a clamping connection with the clamping plate 333 of the mortise. The cross-sectional diameter of the mortise gradually increases from the entrance to the bottom substrate 331, matching the change in the cross-sectional diameter of the flange portion 312, so that the flange portion 312 can be gradually "locked" in the mortise when inserted into the mortise. This self-locking mechanism ensures the stability of the connection and prevents the flange portion 312 from accidentally falling off due to vibration or impact. The flange portion 312 is inserted into the bottom substrate 331 along the entrance of the mortise. When the flange portion 312 is inserted into the mortise, the clamping end of the mortise is clamped by the entrance of the mortise to achieve clamping. This clamping method provides a firm connection while allowing the flange portion 312 to be disassembled by appropriate operations when necessary.

[0069] Please refer to Figure 5 In this embodiment, the insertion end is provided with an inclined surface 313, and the inclined surface 313 enables the flange portion 312 to be inserted from the entrance of the mortise.

[0070] The inclined surface 313 is an inclined surface of the insertion end of the flange 312, which helps to reduce the friction during insertion, so that the flange 312 can be inserted into the mortise more easily. Through the above scheme, when the flange 312 is inserted into the mortise, the inclined surface 313 first contacts the side wall 322 of the mortise. Due to the design of the inclined surface 313, this can reduce the force required for insertion, making the entire insertion process smoother. The existence of the inclined surface 313 also helps to guide the flange 312 to align with the mortise correctly, reducing the risk of misalignment or jamming. Even if the cross-sectional diameter of the flange 312 gradually increases from the clamping end to the insertion end, the design of the inclined surface 313 allows the flange 312 to be easily inserted in the initial stage. Once passing through the inclined surface 313, the increase in the diameter of the flange 312 will cause it to be clamped in the mortise, achieving self-locking. The design of the insertion end being provided with the inclined surface 313 balances the convenience of insertion and the stability of the connection.

[0071] Figure 6 Schematic diagram of the elastic portion 330 provided in one embodiment of the present application. Figure 7 for Figure 6 The cross-sectional view of the elastic portion 330 along the B-B1 direction provided in FIG. Figure 5 , Figure 6 and Figure 7 The clamping plate 333 is fixed at the entrance of the mortise, the clamping plate 333 is fixed at the outside of the mortise and the clamping plate 333 extends toward the direction of the mortise structure 320.

[0072] Through the above solution, the clamping plate 333 is fixed on the outside of the mortise and extends in the direction of the mortise structure 320. In this design, when the flange 312 is inserted into the mortise, its clamping end will contact and be clamped by the clamping plate 333. Since the clamping plate 333 extends in the direction of the mortise structure 320, it forms a barrier on the outside of the mortise to prevent the flange 312 from falling out of the mortise. The clamping plate 333 provides additional support on the outside of the mortise, enhancing the stability of the connection.

[0073] Figure 8 It is a schematic diagram of an elastic portion 330 provided in another embodiment of the present application. Fig. 9 for Figure 8 The cross-sectional view of the elastic portion 330 along the C-C1 direction provided in FIG. Figure 8 and Fig. 9 The clamping plate 333 is fixed on the inner side of the mortise and the clamping plate 333 extends in a direction away from the mortise and tenon structure 320 .

[0074] The clamping plate 333 is fixed on the inner side of the mortise and extends in a direction away from the mortise structure 320. In this design, after the clamping end of the flange 312 is inserted into the mortise, the clamping end will be clamped by the clamping plate 333. The clamping plate 333 forms a reverse block on the inner side of the mortise, so that the flange 312 cannot easily escape from the mortise. The design of the clamping plate 333 on the inner side of the mortise makes the overall structure more compact, reduces the external protruding part, and is more suitable for applications with limited space.

[0075] The above two methods of fixing the clamping plate 333 each have their own advantages, and which one to choose depends on the specific application requirements and design considerations. The first method may be more suitable for scenarios that require higher stability and easy operation, while the second method may be more suitable for applications with limited space or requiring a concealed clamping mechanism. The appropriate method of fixing the clamping plate 333 can be selected based on factors such as the specific use environment of the battery cell, maintenance requirements, and manufacturing costs.

[0076] Please refer to Figure 6 and Figure 8 The movable waist plate 332 may be composed of a plurality of dispersed plates, which surround a circle to form the main body of the mortise. When the flange 312 is inserted, the plurality of dispersed plates may be automatically adjusted according to the shape of the flange 312 to form a mortise with an elastic effect. Figure 6 and Figure 8 The movable waist plate 332 is respectively composed of four dispersed plates.

[0077] In one embodiment, a conductive adhesive is provided between the flange portion 312 and the movable waist plate 332. The conductive adhesive is an adhesive having certain conductive properties after curing or drying, and is mainly composed of a base resin and a conductive filler (such as metal powder). The conductive particles are combined together by the bonding effect of the base resin to form a conductive path, thereby realizing a conductive connection of the bonded material. The conductive adhesive can provide a stable conductive connection, and its conductive mechanism is mainly that the conductive particles are in contact with each other to form an electrical path. After curing or drying, the volume of the adhesive shrinks due to the volatilization of the solvent and the curing of the adhesive, so that the conductive particles are in stable and continuous contact with each other, thus showing conductivity. By providing a conductive adhesive between the flange portion 312 and the movable waist plate 332, not only a stable conductive connection can be achieved, but also good mechanical bonding performance can be provided.

[0078] Please refer to Figure 4 In this embodiment, the top cover also includes an upper plastic 110, a lower plastic 120 and a sealing ring 150; the upper plastic 110 is provided above the outer periphery of the side wall 322 of the tenon portion, and the lower plastic 120 is provided below the outer periphery of the side wall 322 of the tenon portion, and the sealing ring 150 is arranged between the upper plastic 110 and the lower plastic 120.

[0079] By arranging the upper plastic 110 above the outer periphery of the side wall 322 of the tongue and groove portion, and ensuring that it is electrically connected to the positive pole and insulated from the negative pole, it is possible to prevent accidental short circuits during battery use, thereby improving the safety of the battery. The lower plastic 120 can be laid flat below the top cover body 100, forming an insulated connection with the pole structure 300, which helps to reasonably distribute and manage the heat inside the battery, prevent local overheating, and reduce the risk of thermal runaway of the battery. The tongue and groove portion passes through the lower plastic 120 and the bottom plate 321 is electrically connected to the connecting piece 210 by welding. The use of the upper and lower plastics 120 can enhance the connection strength between the pole and the top cover, and improve the structural stability of the entire battery top cover.

[0080] The design of the sealing structure needs to take into account the sealing requirements of the battery cell in different use environments, including factors such as temperature changes, pressure changes, and chemical corrosion. A sealing ring 150 is provided between the upper plastic 110 and the lower plastic 120, which can effectively prevent the exchange of substances between the inside of the accommodation cavity where the bare battery cell 201 is located and the external environment, prevent moisture, dust, etc. from invading the battery interior, and improve the protection level of the battery.

[0081] Through the above solution, the upper plastic 110, the lower plastic 120 and the sealing ring 150 together constitute the sealing structure of the battery cell top cover, which can effectively protect the electrical components inside the battery cell and extend the service life of the battery cell.

[0082] In this embodiment, the top cover further includes an explosion-proof structure 130 and a sealing member 140 , and the explosion-proof structure 130 and the sealing member 140 are disposed on the top cover body 100 .

[0083] Through the above scheme, the explosion-proof structure 130 is an important part of the battery safety design. When the pressure inside the battery increases due to abnormal conditions, the explosion-proof structure 130 can be opened in time to release the internal pressure and prevent the battery from exploding, thereby protecting the safety of the battery and the surrounding environment. The injection hole is a channel for injecting electrolyte during the battery manufacturing process. After the injection is completed, it is necessary to ensure the sealing of the injection hole to prevent electrolyte leakage and the intrusion of external contaminants. The design of the seal 140 can prevent the generation of metal particles and burrs, which may fall into the battery and cause a short circuit. The use of the seal 140 can ensure the cleanliness of the inside of the battery and improve the reliability and safety of the battery.

[0084] Based on the lithium-ion battery cell mentioned above, this embodiment further provides a power battery, including a busbar and any one of the lithium-ion battery cells mentioned above, wherein the lithium-ion battery cell is connected to the busbar.

[0085] Since the structure and beneficial effects of the lithium-ion battery cell have been described in detail in the previous embodiments, they will not be described in detail in this application.

[0086] The above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application.

Claims

1. A lithium-ion battery cell, characterized in that: include: A bare cell, a top cover and a shell, wherein the top cover and the shell together form a receiving cavity, and the bare cell is located in the receiving cavity; The top cover comprises a top cover body, and a pole structure is arranged on the top cover body; The pole structure includes a tenon head and a tenon groove structure, the tenon groove structure is arranged through the top cover body, and the tenon head cooperates with the tenon groove structure to form a detachable connection.

2. The lithium-ion battery cell according to claim 1, characterized in that: The tenon portion includes a welding portion and a flange portion connected to the welding portion, the welding portion can form a welding connection with an external busbar, and the flange portion can cooperate and extend into the interior of the tenon-groove structure to form a detachable connection.

3. The lithium-ion battery cell according to claim 2, characterized in that: The tongue-and-groove structure comprises an elastic portion, the elastic portion is fixedly disposed within the tongue-and-groove structure, and the flange portion can be clamped within the elastic portion to form a detachable connection with the elastic portion.

4. The lithium-ion battery cell according to claim 3, characterized in that: The elastic part includes a bottom base plate, a movable waist plate and a clamping plate, wherein the movable waist plate is fixedly arranged along the outer periphery of the bottom base plate to form a mortise groove, and the shape of the mortise groove matches the shape of the flange part; The flange portion has an insertion end and a clamping end away from the insertion end, and the cross-sectional diameter of the flange portion gradually increases in the direction from the clamping end to the insertion end; The cross-sectional diameter of the mortise gradually increases along the direction from the entrance of the mortise to the bottom substrate; The flange portion is inserted along the entrance of the mortise toward the bottom substrate. When the flange portion is inserted into the mortise, the clamping end of the mortise is clamped by the entrance of the mortise.

5. The lithium-ion battery cell according to claim 4, characterized in that: The insertion end is provided with an inclined surface, and the inclined surface enables the flange portion to be inserted from the entrance of the mortise.

6. The lithium-ion battery cell according to claim 4, characterized in that: The clamping plate is fixed at the entrance of the mortise, the clamping plate is fixed on the outside of the mortise and extends in the direction of the mortise structure, or the clamping plate is fixed on the inside of the mortise and extends away from the mortise structure.

7. The lithium-ion battery cell according to claim 4, characterized in that: Conductive glue is arranged between the flange portion and the movable waist plate.

8. The lithium-ion battery cell according to claim 1, characterized in that: The pole structure includes a positive pole structure for electrically connecting to the positive pole piece on the bare battery cell and a negative pole structure for electrically connecting to the negative pole piece on the bare battery cell; the tongue and groove structure includes a bottom plate and a side wall, the bottom plate can be connected to the positive pole piece or the negative pole piece on the bare battery cell, and the outer periphery of the side wall forms a sealed connection with the top cover body.

9. The lithium-ion battery cell according to claim 1, characterized in that: The top cover also includes an upper plastic, a lower plastic, a sealing ring, an explosion-proof structure and a sealing member. The upper plastic is provided above the outer periphery of the side wall of the tenon-groove portion, and the lower plastic is provided below the outer periphery of the side wall of the tenon-groove portion. The sealing ring is provided between the upper plastic and the lower plastic. The explosion-proof structure and the sealing member are provided on the top cover body.

10. A power battery, characterized in that: The invention comprises a busbar and a lithium-ion battery cell as claimed in any one of claims 1 to 9, wherein the tenon head can be connected to the busbar so that the lithium-ion battery cell is connected to the busbar.

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