Cover plate assembly and battery

Abstract

The invention belongs to the technical field of batteries, and discloses a cover plate assembly and a battery, the cover plate assembly is connected with a pole group, the pole group is connected with a tab, the cover plate assembly comprises a cover plate body, a pole column, a first lower plastic cement and a second lower plastic cement, the first lower plastic cement and the second lower plastic cement are connected with each other, and the pole column is arranged on the cover plate body; the first lower plastic is connected with the side, facing the pole group, of the cover plate body, the second lower plastic is arranged between the first lower plastic and the pole group and comprises a bottom plate, a first protrusion and a second protrusion, and the first protrusion and the second protrusion are both arranged on the side, facing the first lower plastic, of the bottom plate. And the first bulge and the second bulge are respectively arranged on two sides of the tab along the length direction of the tab. Therefore, the bottom plate is abutted against the pole group, so that the pressure on the pole group is more uniform, a naked battery core insulating film and a tab on the end surface of the pole group are prevented from being crushed, and the battery core assembly yield and the safety performance are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cover plate assembly and a battery. Background Art

[0002] Lithium batteries occupy an important position in the field of modern high-performance batteries due to their advantages such as high working voltage, high specific energy, large capacity, low self-discharge, good cycle performance, long service life, light weight, and small volume.

[0003] The long-core lithium-ion battery includes a cover plate, a housing, a bare cell insulating film, a pole group, an electrolyte, etc. The cover plate includes structures such as pole columns, light aluminum sheets, lower plastics, explosion-proof valves, etc. After the light aluminum sheet is welded to the housing, it forms a sealed space with a certain mechanical strength to protect the pole group and realizes the assembly of the housing and the cover. The pole group is welded to the pole column on the cover plate through pole tabs to achieve electrical connection, so that the pole column leads out the current inside the cell. The lower plastic is arranged between the pole group and the light aluminum sheet. On the one hand, it plays an insulating and protective role and provides an insulating space for protecting the pole tabs. On the other hand, it can abut against the pole group and realize the press-fitting and fixing of the pole group to prevent the pole group from shaking inside the housing.

[0004] The long-core lithium-ion battery usually adopts a design with the positive and negative pole tabs leading out from both sides. During assembly, first weld one of the pole tabs to the corresponding cover plate, wrap the bare cell insulating film around the pole group and thermally fix it with the lower plastic of the cover plate, insert the pole group into the housing, and weld the cover plate and the housing. Then weld the other pole tab to the corresponding cover plate, and weld the cover plate with the welded pole tab to the housing. Since the pole tabs are usually not centered on the end face of the pole group, the areas of the lower plastic bosses on both sides of the pole tab are different, and the lower plastic bosses directly abut against the end face of the pole group. During the process of inserting the cover plate into the housing, it is easy to cause uneven stress on the positions of the corresponding bosses on both sides of the pole group, and then the bare cell insulating film and the pole tabs of the pole group are easily damaged, seriously affecting the assembly yield and safety performance of the cell. Summary of the Invention

[0005] The purpose of the present invention is to provide a cover plate assembly and a battery to solve the problems of uneven stress on the pole group, low assembly yield of the cell, and poor safety performance.

[0006] To achieve this purpose, the present invention adopts the following technical solutions:

[0007] In a first aspect, a cover plate assembly is connected to a pole group, and the pole group is connected with a pole tab. The cover plate assembly includes: a cover plate body and a pole column, and the pole column is arranged on the cover plate body; a first lower plastic and a second lower plastic which are connected to each other, the first lower plastic is connected to one side of the cover plate body facing the pole group, the second lower plastic is arranged between the first lower plastic and the pole group, the second lower plastic includes a bottom plate, a first protrusion and a second protrusion, and the first protrusion and the second protrusion are both arranged on one side of the bottom plate facing the first lower plastic, and the first protrusion and the second protrusion are respectively arranged on two sides of the pole tab along its length direction.

[0008] Preferably, the height range of the first lower plastic is 2 mm - 2.5 mm; and / or, the height range of the second lower plastic is 2 mm - 2.5 mm.

[0009] Preferably, the bottom plate is provided with an avoidance hole for the pole tab to pass through, and the length direction of the avoidance hole is parallel to the length direction of the pole tab.

[0010] Preferably, the width range of the avoidance hole is 1.5 mm - 3 mm.

[0011] Preferably, the connection between the hole wall of the avoidance hole and the bottom plate is smoothly transitioned.

[0012] Preferably, connection bosses are arranged at positions of the first lower plastic corresponding to the first protrusion and the second protrusion, so that the first lower plastic is inserted into the second lower plastic.

[0013] Preferably, the cover plate assembly further includes a positioning member, and the positioning member is arranged on the first lower plastic or the second lower plastic to limit the relative positions of the first lower plastic and the second lower plastic.

[0014] Preferably, the positioning member is a positioning buckle, the positioning buckle is arranged on one of the first lower plastic and the second lower plastic, and a positioning groove is opened at the position of the other corresponding to the positioning buckle, and the positioning buckle is inserted into the positioning groove.

[0015] Preferably, the first lower plastic and the second lower plastic enclose to form an accommodation space for accommodating the pole tab, and one end of the pole column facing the pole group is located in the accommodation space, so that the pole column is electrically connected to the pole tab.

[0016] In a second aspect, a battery includes a pole group, a housing and the cover plate assembly as described above, the cover plate body is connected to the housing, and the pole group is arranged inside the housing.

[0017] Advantages of the present invention:

[0018] A cover plate assembly is connected to a pole group, and a pole ear is connected to the pole group. The cover plate assembly includes a cover plate body, a pole column, and a first lower plastic and a second lower plastic connected to each other. The pole column is arranged on the cover plate body; the first lower plastic is connected to a side of the cover plate body facing the pole group, and the second lower plastic is arranged between the first lower plastic and the pole group. The second lower plastic includes a bottom plate, a first protrusion and a second protrusion. The first protrusion and the second protrusion are both arranged on a side of the bottom plate facing the first lower plastic, and the first protrusion and the second protrusion are respectively arranged on both sides of the pole ear along its length direction.

[0019] In this way, a bottom plate is provided and the first protrusion and the second protrusion are located on the side of the bottom plate away from the pole group, so that the bottom plate can provide uniform pressure to the end face of the pole group while maintaining the structural strength of the area of ​​the end face of the pole group where the pole ear is not provided, and the position of the pole ear is limited by the first protrusion and the second protrusion, so as to avoid displacement of the pole ear during assembly, and avoid crushing of the bare battery cell insulating film and the pole ear due to uneven force during assembly, thereby improving the assembly yield and safety performance of the battery cell, and the split design of the first lower plastic and the second lower plastic can simplify the assembly steps, improve the assembly efficiency, facilitate the stable connection of the pole ear and the pole column, and realize the rapid assembly of the cover plate assembly. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic structural diagram of a battery in one embodiment of the present invention;

[0021] Figure 2 is a first partial exploded schematic diagram of a battery in one embodiment of the present invention;

[0022] Figure 3 is a second partial exploded schematic diagram of a battery in one embodiment of the present invention;

[0023] Figure 4 Schematic diagram of the structure of the second lower plastic in one embodiment of the present invention.

[0024] In the figure:

[0025] 1. Cover plate body; 2. Pole; 3. First lower plastic; 31. Connecting boss; 4. Second lower plastic; 41. Bottom plate; 42. First protrusion; 43. Second protrusion; 44. Avoidance hole; 45. Positioning groove; 5. Positioning piece; 6. Pole group; 61. Pole ear; 7. Shell. DETAILED DESCRIPTION

[0026] The present invention will be further described in detail below in conjunction with the accompanying drawings and embodiments. It is to be understood that the specific embodiments described herein are only used to explain the present invention, rather than to limit the present invention. It should also be noted that, for ease of description, only parts related to the present invention, rather than all structures, are shown in the accompanying drawings.

[0027] In the description of the present invention, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" shall be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, or integrated; it may be a mechanical connection or an electrical connection; it may be directly connected or indirectly connected through an intermediate medium, and it may be the communication inside two components or the interaction relationship between two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0028] In the present invention, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features between them. Moreover, the first feature being "above", "over", and "on top of" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "beneath", and "underneath" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0029] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or component referred to must have a specific orientation, be constructed and operated in a specific orientation, so it should not be construed as a limitation to the present invention. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0030] Referring to Figure 1 and Figure 2 , the present invention provides a cover plate assembly, which is connected to the electrode group 6. The electrode group 6 is connected with an electrode tab 61. The cover plate assembly includes: a cover plate body 1, a terminal post 2, a first lower plastic 3 and a second lower plastic 4 which are connected to each other. The terminal post 2 is arranged on the cover plate body 1; the first lower plastic 3 is connected to the side of the cover plate body 1 facing the electrode group 6, the second lower plastic 4 is arranged between the first lower plastic 3 and the electrode group 6. The second lower plastic 4 includes a bottom plate 41, a first protrusion 42 and a second protrusion 43. Both the first protrusion 42 and the second protrusion 43 are arranged on the side of the bottom plate 41 facing the first lower plastic 3, and the first protrusion 42 and the second protrusion 43 are respectively arranged on both sides of the electrode tab 61 along its length direction.

[0031] In this embodiment, pole lugs 61 are respectively connected to both ends of the pole group 6. The length direction of the cover plate body 1 is parallel to the height direction of the pole group 6. The pole column 2 is fixedly arranged on the cover plate body 1, and one end of the pole column 2 facing the pole group 6 passes through the cover plate body 1 and is fixedly connected to the pole lug 61 by welding. The length directions of the first lower plastic 3 and the second lower plastic 4 are both parallel to the length direction of the cover plate body 1. The first protrusion 42 and the second protrusion 43 are integrally formed on the bottom plate 41, and the first protrusion 42 and the second protrusion 43 are respectively arranged at both ends of the bottom plate 41 and are flush with the two end faces of the bottom plate 41. When the first lower plastic 3 is connected to the second lower plastic 4, along the length direction of the bottom plate 41, the first protrusion 42, the pole lug 61, and the second protrusion 43 are arranged in sequence, and the side surface of the bottom plate 41 facing away from the first lower plastic 3 abuts against the end face of the pole group 6; a plurality of exhaust holes (not shown in the figure) are opened at positions corresponding to the first protrusion 42 and the second protrusion 43 on the bottom plate 41.

[0032] In this way, by arranging the bottom plate 41 to abut against the pole group 6, the force on the end face of the pole group 6 can be made more uniform during the process of inserting the pole group 6 into the shell, avoiding damage to the bare cell insulation film on the end face of the pole group 6 and the pole lug 61, improving the assembly yield and safety performance of the cell. Moreover, the first protrusion 42 and the second protrusion 43 can stably support the end face of the pole group 6 and limit the position of the pole lug 61. The connection of the first lower plastic 3 and the second lower plastic 4 can improve the overall structural strength of the cover plate assembly and enhance the insulation between the cover plate body 1 and the pole group 6. Furthermore, the pole lug 61 can be protected by the first lower plastic 3 and the second lower plastic 4, and the current inside the cell can be stably transmitted to the outside through the pole column 2; by arranging the pole lug 61 between the first lower plastic 3 and the second lower plastic 4, the assembly efficiency can be improved, facilitating the assembly of the cover plate assembly.

[0033] It can be understood that the setting positions of the first protrusion 42 and the second protrusion 43 on the bottom plate 41 can be adjusted according to actual needs and will not be elaborated here.

[0034] Refer to Figure 2 , in some embodiments, the height range of the first lower plastic 3 is 2 mm - 2.5 mm, and the height range of the second lower plastic 4 is 2 mm - 2.5 mm.

[0035] In this embodiment, the height of the first lower plastic 3 can be any value between 2 mm and 2.5 mm or the range between any two values, such as 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, etc.; the height of the second lower plastic 4 can be any value between 2 mm and 2.5 mm or the range between any two values, such as 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, etc.

[0036] It should be noted that the heights of the first protrusion 42 and the second protrusion 43 are equal, and the height of the second lower plastic 4 is the sum of the heights of the first protrusion 42 and the bottom plate 41.

[0037] In this way, the first lower plastic 3 and the second lower plastic 4 can have sufficient structural strength, making the force on the electrode group 6 more uniform during the assembly process, reducing the damage to the insulation film of the bare battery cell and the tab 61, improving the assembly yield and safety performance of the battery cell. Moreover, the first protrusion 42 and the second protrusion 43 can improve the structural strength at the end face of the electrode group 6 where no tab 61 is provided. The bottom plate 41 abuts against the end face of the electrode group 6, which can avoid uneven stress on both sides of the tab 61 and improve the connection stability between the cover plate assembly and the electrode group 6.

[0038] It can be understood that the height of the first lower plastic 3 cannot be too large. If it is too large, it will increase the overall size of the cover plate assembly, and may interfere with other components during assembly, affecting the assembly yield and being unfavorable for heat dissipation. The height of the first lower plastic 3 cannot be too small either. If it is too small, the structural strength of the first lower plastic 3 will be insufficient, making it difficult to provide stable support for the second lower plastic 4 and the electrode group 6, making it difficult for the electrode group 6 to be fixed by the first lower plastic 3 and the second lower plastic 4, affecting the structural stability and reliability of the battery, and having poor insulation performance. The height of the second lower plastic 4 cannot be too large. If it is too large, it will cause uneven stress on the electrode group 6 during the assembly process and cause local stress concentration, further resulting in uneven stress on the end face of the electrode group 6, affecting the assembly yield and safety performance of the battery cell. The height of the second lower plastic 4 cannot be too small either. If it is too small, the structural strength will be insufficient, making it difficult to play a role in supporting and protecting the electrode group 6, and having poor insulation performance. The heights of the first lower plastic 3 and the second lower plastic 4 can be equal or unequal, as long as the first lower plastic 3 and the second lower plastic 4 can have sufficient structural strength and can be stably connected, which will not be elaborated here.

[0039] Refer to Figure 3 , in some embodiments, the bottom plate 41 is provided with an avoidance hole 44 for the tab 61 to pass through, and the length direction of the avoidance hole 44 is parallel to the length direction of the tab 61.

[0040] In this embodiment, the avoidance hole 44 is provided on one side in the width direction of the bottom plate 41 and is set corresponding to the position of the tab 61. The length of the avoidance hole 44 is greater than the length of the tab 61. The first protrusion 42 and the second protrusion 43 are respectively arranged on both sides in the length direction of the avoidance hole 44 to prevent the tab 61 from interfering with the first protrusion 42 and the second protrusion 43.

[0041] It should be noted that when assembling the cover plate assembly, first connect the pole column 2 with the cover plate body 1 and the first lower plastic 3, then weld the pole ear 61 to the pole column 2 to achieve the electrical connection between the pole ear 61 and the pole column 2. Assemble the second lower plastic 4 to the first lower plastic 3 and make the pole ear 61 located in the avoidance hole 44, which can protect and position the pole ear 61.

[0042] In this way, by setting the avoidance hole 44, when the second lower plastic 4 is connected to the first lower plastic 3, it can avoid the interference between the pole ear 61 and the second lower plastic 4, which may cause the pole ear 61 to be crushed. At the same time, the first protrusion 42 and the second protrusion 43 can provide a stable supporting force for the bottom plate 41, so that the bottom plate 41 is in close contact with the end face of the pole group 6 and the force is more uniform, avoiding one end of the end face of the pole group 6 from being under greater pressure, reducing the crushing of the insulation film of the bare battery cell and the pole ear 61, and improving the assembly yield and safety performance of the battery cell. And the first lower plastic 3 and the second lower plastic 4 are designed separately, which can facilitate the stable connection between the pole ear 61 and the pole column 2 and then assemble the cover plate assembly to the pole group 6, so that the bottom plate 41 provides a stable and uniform pressure on the pole group 6, improving the assembly efficiency.

[0043] It can be understood that the setting position and length of the avoidance hole 44 can be adjusted according to the position of the pole ear 61 on the pole group 6, as long as the interference between the second lower plastic 4 and the pole ear 61 can be avoided, and no more examples will be listed here.

[0044] Refer to Figure 3 , in some embodiments, the width a of the avoidance hole 44 ranges from 1.5 mm to 3 mm.

[0045] In this embodiment, the width of the avoidance hole 44 can be any value between 1.5 mm and 3 mm or the range between any two values, such as 1.5 mm, 2 mm, 2.5 mm, 3 mm, etc.

[0046] In this way, during the process of assembling the second lower plastic 4 to the first lower plastic 3 and welding the cover plate body 1 to the housing 7, even if the cover plate assembly is turned over, the avoidance hole 44 can provide sufficient bending space for the pole ear 61, so that the pole ear 61 located between the first lower plastic 3 and the second lower plastic 4 can be well protected, avoiding the pole ear 61 from being crushed by the first lower plastic 3 or the second lower plastic 4, and enabling the bottom plate 41 to have sufficient structural strength, so that the bottom plate 41 can provide a uniform pressure on the end face of the pole group 6 when it abuts against the end face of the pole group 6.

[0047] It can be understood that the width of the avoidance hole 44 cannot be too large, as this will result in insufficient structural strength of the bottom plate 41 and reduce the contact area between the bottom plate 41 and the end face of the electrode group 6. Nor can the width of the avoidance hole 44 be too small, as this will cause interference with the tab 61 and increase the risk of the tab 61 being crushed or scratched. The width of the avoidance hole 44 can be adjusted according to the size of the tab 61, and no more details will be listed here.

[0048] Refer to Figure 4 , in some embodiments, the connection between the hole wall of the avoidance hole 44 and the bottom plate 41 is provided with a smooth transition.

[0049] In this way, it is possible to reduce the rubbing between the hole wall of the avoidance hole 44 and the tab 61, avoid the tab 61 being scratched or cut, enable the tab 61 to remain intact during the bending process, improve the assembly yield and safety performance of the battery cell, and since the hole wall of the avoidance hole 44 is smooth, it is convenient to assemble the second lower plastic 4 to the first lower plastic 3 and reduce the interference with the tab 61, improving the reliability of the cover plate assembly.

[0050] Refer to Figure 2 , in some embodiments, connection bosses 31 are provided at the positions of the first lower plastic 3 corresponding to the first protrusion 42 and the second protrusion 43, so that the first lower plastic 3 and the second lower plastic 4 are plugged together.

[0051] In this embodiment, there are two connection bosses 31, and the two connection bosses 31 are integrally formed at both ends of the first lower plastic 3 respectively, and the shapes of the two connection bosses 31 are respectively adapted to the shapes of the first protrusion 42 and the second protrusion 43, so that the first protrusion 42 and the second protrusion 43 are respectively plugged into the corresponding connection bosses 31, which can limit the relative positions of the first lower plastic 3 and the second lower plastic 4 and facilitate the assembly of the cover plate assembly.

[0052] In this way, the first lower plastic 3 and the second lower plastic 4 are positioned through the connection bosses 31, which can improve the assembly efficiency, avoid the second lower plastic 4 from shifting during the assembly process and causing crushing or scratching of the tab 61, improve the assembly yield and safety performance of the battery cell, and improve the connection stability between the cover plate assembly and the electrode group 6, so that the current inside the battery cell is transmitted to the external circuit through the pole post 2, improving the reliability of the cover plate assembly.

[0053] It can be understood that the positions where the connection bosses 31 are provided can be adjusted according to the positions of the first protrusion 42 and the second protrusion 43, and no further elaboration will be given here.

[0054] Refer to Figure 2 and Figure 3, in some embodiments, the cover plate assembly further includes a positioning member 5, and the positioning member 5 is disposed on the first lower plastic 3 or the second lower plastic 4 to limit the relative positions of the first lower plastic 3 and the second lower plastic 4. In this embodiment, the positioning member 5 is disposed on the first lower plastic 3.

[0055] In this way, the positioning member 5 can further limit the relative positions of the first lower plastic 3 and the second lower plastic 4, so that the first lower plastic 3 and the second lower plastic 4 protect the tab 61, and the first protrusion 42 and the second protrusion 43 always correspond to the positions on the end face of the electrode group 6 where no tab 61 is provided, so as to achieve stable abutment and support of the bottom plate 41 against the end face of the electrode group 6, and make the positions on the end face of the electrode group 6 corresponding to the first protrusion 42, the positions where the tabs 61 are provided, and the positions corresponding to the second protrusion 43 receive more uniform forces, avoiding damage to the insulation film of the bare battery cell and the tabs 61 after the cover plate body 1 and the electrode group 6 are assembled, and improving the assembly yield and safety performance of the battery cell.

[0056] It can be understood that the setting position of the positioning member 5 can be adjusted according to actual needs and will not be elaborated here.

[0057] Refer to Figure 2 , in some embodiments, the positioning member 5 is a positioning buckle. The positioning buckle is disposed on one of the first lower plastic 3 and the second lower plastic 4, and a positioning groove 45 is provided at the position corresponding to the positioning buckle on the other one, and the positioning buckle is inserted into the positioning groove 45.

[0058] In this embodiment, the positioning buckle is integrally formed with the first lower plastic 3. The positioning buckle is disposed perpendicular to the surface of the first lower plastic 3 facing the second lower plastic 4. There are multiple positioning buckles. Four positioning buckles are provided on the connecting boss 31 corresponding to the first protrusion 42, and the four positioning buckles are symmetrically disposed along the length direction of the first lower plastic 3. Two positioning buckles are provided on the connecting boss 31 corresponding to the second protrusion 43, and the two positioning buckles are symmetrically disposed along the length direction of the first lower plastic 3. Positioning grooves 45 are provided at the positions corresponding to the positioning buckles on the second lower plastic 4, that is, the positioning grooves 45 are respectively provided on the surface of the first protrusion 42 facing the first lower plastic 3 and the surface of the second protrusion 43 facing the first lower plastic 3.

[0059] In this way, inserting the positioning buckle into the positioning groove 45 can quickly position and fix the first lower plastic 3 and the second lower plastic 4, avoiding the positional deviation between the first lower plastic 3 and the second lower plastic 4 during the subsequent assembly process, enabling a tight connection between the first lower plastic 3 and the second lower plastic 4, thereby protecting the tab 61 and restricting the relative position of the tab 61 between the first lower plastic 3 and the second lower plastic 4, reducing the risk of the tab 61 becoming loose or being scratched by other structures during assembly and use, and improving the structural strength of the connection between the first lower plastic 3 and the second lower plastic 4, thereby enhancing the stability of the cover assembly, enabling the bottom plate 41 to stably apply pressure to the end face of the electrode assembly 6, avoiding damage to the bare cell insulation film and the tab 61 of the electrode assembly 6, and improving the assembly yield and safety performance of the cell.

[0060] It can be understood that the positioning member 5 can also be a positioning pin. In this embodiment, an integrally formed positioning buckle is used, which can improve the processing efficiency of the first lower plastic 3 and is conducive to mass production. The specific type of the positioning member 5 can be adjusted according to actual needs and will not be listed in detail here.

[0061] Refer to Figure 2 , in some embodiments, the first lower plastic 3 and the second lower plastic 4 enclose to form a receiving space (not shown in the figure) for receiving the tab 61, that is, the side walls of the first protrusion 42 and the second protrusion 43 close to each other, the surface of the bottom plate 41 facing the first lower plastic 3, and the surface of the first lower plastic 3 facing the bottom plate 41 form the receiving space, and one end of the terminal post 2 facing the electrode assembly 6 is located in the receiving space to enable electrical connection between the terminal post 2 and the tab 61.

[0062] In this embodiment, one end of the terminal post 2 facing the electrode assembly 6 is arranged close to the second protrusion 43, and the terminal post 2 and one end of the tab 61 are fixedly connected by welding.

[0063] It should be noted that after the terminal post 2 is connected to the cover body 1, one end of the terminal post 2 facing the electrode assembly 6 passes through the first lower plastic 3 and is located between the two connecting bosses 31. The tab 61 and the terminal post 2 are welded to achieve electrical connection between the tab 61 and the terminal post 2, and the positioning buckle is inserted into the positioning groove 45, and the first protrusion 42 and the second protrusion 43 are respectively inserted into the corresponding connecting bosses 31 to fix the first lower plastic 3 and the second lower plastic 4, and the tab 61 is located in the receiving space, so that the first lower plastic 3 and the second lower plastic 4 provide protection and limitation for the tab 61. Then, the electrode assembly 6 is put into the shell, and after the tab 61 is bent, the cover body 1 and the shell 7 are fixedly connected by welding to complete the assembly of the cover assembly.

[0064] Thus, the tab 61 is located within the accommodation space, which can not only avoid interference with external structures, but also achieve stable electrical connection with the terminal post 2 under the protection of the first lower plastic 3 and the second lower plastic 4, enabling the current generated by the battery cell to be transmitted to the external circuit through the terminal post 2. The first protrusion 42 and the second protrusion 43 can improve the structural strength of the area of the end face of the electrode assembly 6 where no tab 61 is provided, limit the position of the tab 61, prevent the tab 61 from shifting, and provide a stable supporting force and pressure to the electrode assembly 6. The bottom plate 41 can be evenly abutted against the end face of the electrode assembly 6, making the force on the end face of the electrode assembly 6 more uniform, avoiding damage to the insulating film of the bare battery cell and the tab 61 during the assembly process, improving the assembly yield and safety performance of the battery cell, and further enhancing the stability and reliability of the battery.

[0065] Referring to Figure 1 , the present invention further provides a battery, which includes an electrode assembly 6, a housing 7, and a cover plate assembly. The cover plate body 1 is connected to the housing 7, and the electrode assembly 6 is disposed inside the housing 7.

[0066] In this embodiment, two tabs 61 are provided, which are a positive tab and a negative tab respectively. Two cover plate assemblies are correspondingly provided, and the two cover plate assemblies are respectively connected to the positive tab and the negative tab. The cover plate body 1 and the housing 7 are welded to form a sealed space, so that the electrode assembly 6 can be protected by the cover plate body 1 and the housing 7, and electrolyte leakage can be avoided.

[0067] Obviously, the above embodiments of the present invention are merely examples for clearly explaining the present invention, rather than limitations on the implementation manners of the present invention. For those of ordinary skill in the art, various obvious changes, re-adjustments, and substitutions can be made without departing from the protection scope of the present invention. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions, and improvements made within the spirit and principle of the present invention shall be included in the protection scope of the claims of the present invention.

Claims

1. A cover plate assembly, characterized in that, It is connected to the electrode group (6), and the electrode group (6) is connected with an electrode tab (61). The cover plate assembly includes: A cover plate body (1) and a pole column (2), and the pole column (2) is arranged on the cover plate body (1); A first lower plastic (3) and a second lower plastic (4) which are connected to each other. The first lower plastic (3) is connected to the side of the cover plate body (1) facing the electrode group (6). The second lower plastic (4) is arranged between the first lower plastic (3) and the electrode group (6). The second lower plastic (4) includes a bottom plate (41), a first protrusion (42) and a second protrusion (43). The first protrusion (42) and the second protrusion (43) are both arranged on the side of the bottom plate (41) facing the first lower plastic (3). The first protrusion (42) and the second protrusion (43) are respectively arranged on both sides of the electrode tab (61) along its length direction.

2. The cover plate assembly according to claim 1, characterized in that, The height range of the first lower plastic (3) is 2 mm - 2.5 mm; and / or, the height range of the second lower plastic (4) is 2 mm - 2.5 mm.

3. The cover plate assembly according to claim 1, wherein, The bottom plate (41) is provided with an avoidance hole (44) for the electrode tab (61) to pass through, and the length direction of the avoidance hole (44) is parallel to the length direction of the electrode tab (61).

4. The cover plate assembly according to claim 3, characterized in that, The width range of the avoidance hole (44) is 1.5 mm - 3 mm.

5. The cover plate assembly according to claim 3, wherein, The connection between the hole wall of the avoidance hole (44) and the bottom plate (41) is set with a smooth transition.

6. The cover plate assembly according to claim 1, wherein The first lower plastic (3) is provided with connection bosses (31) at positions corresponding to the first protrusion (42) and the second protrusion (43) respectively, so that the first lower plastic (3) is inserted into the second lower plastic (4).

7. The cover plate assembly according to any one of claims 1-6, characterized in that, The cover plate assembly further includes a positioning member (5), and the positioning member (5) is arranged on the first lower plastic (3) or the second lower plastic (4) to limit the relative position between the first lower plastic (3) and the second lower plastic (4).

8. The cover plate assembly according to claim 7, wherein, The positioning member (5) is a positioning buckle. The positioning buckle is arranged on one of the first lower plastic (3) and the second lower plastic (4), and the other is provided with a positioning groove (45) corresponding to the position of the positioning buckle. The positioning buckle is inserted into the positioning groove (45).

9. The cover plate assembly according to any one of claims 1-6, characterized in that, The first lower plastic (3) and the second lower plastic (4) enclose a receiving space for receiving the electrode tab (61). One end of the pole column (2) facing the electrode group (6) is located in the receiving space, so that the pole column (2) is electrically connected to the electrode tab (61).

10. A battery, characterized in that, It includes an electrode group (6), a housing (7) and the cover plate assembly according to any one of claims 1 - 9. The cover plate body (1) is connected to the housing (7), and the electrode group (6) is arranged inside the housing (7).

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