Battery assembly and battery module
By designing the manifold through-hole to be smaller than the tab width and connecting it to the cover plate, the problem of tabs sticking out was solved, improving the reliability and safety of the battery, ensuring uniform electrolyte wetting and normal operation of the explosion-proof valve.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-31
- Publication Date
- 2026-03-10
AI Technical Summary
The openings on the manifolds at both ends of the battery cause the tabs to stick out, affecting the flow of electrolyte and the normal operation of the explosion-proof valve, thus reducing the reliability and safety of the battery.
Design a manifold with a through hole whose maximum width in the electrode winding direction is smaller than the electrode tab width and is connected to a cover plate to form a tight seal to prevent the electrode tab from popping out. At the same time, at least two through holes are provided to ensure that the pressure relief function is not affected.
This improves battery reliability and safety, ensures uniform electrolyte wetting, prevents accidental contact of the explosion-proof valve with the tabs, ensures normal pressure relief function, and enhances the overall reliability and safety of the battery.
Smart Images
Figure CN223986676U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of battery manufacturing technology, and in particular to a battery component and battery module. Background Technology
[0002] A battery typically consists of a metal casing, a winding core, a busbar, and a cover plate. The winding core may include stacked positive and negative electrode plates, and a separator located between the positive and negative electrode plates. Here, the positive electrode plate, separator, and negative electrode plate can be wound together to form the winding core.
[0003] The core has multiple evenly arranged positive electrode tabs on one side of the positive electrode sheet and multiple evenly arranged negative electrode tabs on one side of the negative electrode sheet. The multiple positive electrode tabs can be bent and welded to one busbar, and the multiple negative electrode tabs can also be bent and welded to another busbar, and these two busbars can be distributed at both ends of the battery.
[0004] However, the battery has openings on the busbars at both ends. One of the positive tabs can easily pop out of the opening of the corresponding busbar, and one of the negative tabs can also easily pop out of the opening of the corresponding busbar, resulting in low battery reliability. Utility Model Content
[0005] This application provides a battery assembly and a battery module. It can solve the problem of poor battery reliability in existing technologies. The technical solution is as follows:
[0006] On one hand, a battery assembly is provided, comprising:
[0007] Core, busbar and cover plate;
[0008] The core includes: an electrode sheet wound into one piece, and a plurality of tabs connected to one side of the electrode sheet, wherein the plurality of tabs can be bent in a direction toward the central axis of the core;
[0009] The busbar is located at one end of the core, and the busbar is welded to at least a portion of the bent electrode tab; the busbar has at least two through holes, and in the winding direction of the electrode sheet, the maximum width of each through hole is less than the width of the electrode tab;
[0010] The cover plate is connected to the side of the manifold away from the core, and the cover plate has an installation opening that is connected to the at least two through holes.
[0011] Optionally, each of the through holes includes: a rectangular region and a fan-shaped region connected together, wherein the rectangular region is closer to the outer boundary of the manifold than the fan-shaped region;
[0012] Wherein, in the winding direction of the electrode sheet, the maximum width of the through hole is the width of the rectangular region.
[0013] Optionally, if the number of through holes in the manifold is two, the manifold further includes a support strip located between the two through holes;
[0014] The two through holes are symmetrically distributed on both sides of the center line of the support strip.
[0015] Optionally, the diameter of the circle containing the sector area is equal to the sum of the widths of the two rectangular areas in the two through holes and the width of the support strip.
[0016] Optionally, within the same through-hole, the distance between the side of the rectangular region facing away from the fan-shaped region and the outer boundary of the manifold is greater than 0.
[0017] Optionally, the orthographic projection of the at least two through holes on the end face of the core is located within the orthographic projection of the mounting opening in the cover plate on the end face of the core.
[0018] Optionally, the manifold includes: a manifold body and a connecting portion connected together; the at least two through holes are located on the manifold body, and the cover plate is connected to the connecting portion.
[0019] Optionally, there are two pole pieces, namely a first pole piece and a second pole piece; the pole tab connected to the first pole piece is the first pole tab, and the pole tab connected to the second pole piece is the second pole tab, and multiple first pole tabs and multiple second pole tabs are respectively distributed at both ends of the winding core;
[0020] The number of busbars is two, namely a first busbar and a second busbar. The first busbar is welded to at least a portion of the first electrode tab after bending, and the second busbar is welded to at least a portion of the second electrode tab after bending.
[0021] Optionally, the cover plate includes: a first cover plate and a second cover plate, wherein the first cover plate is located on the side of the first manifold away from the core, and the mounting opening on the first cover plate is used for injecting electrolyte; the second cover plate is located on the side of the second manifold away from the core, and the mounting opening on the second cover plate is used for installing an explosion-proof valve.
[0022] On the other hand, battery modules are provided, including:
[0023] Multiple interconnected battery modules, wherein the battery modules are any of the battery modules described above.
[0024] The beneficial effects of the technical solutions provided in this application include at least the following:
[0025] Because the maximum width of each through-hole in the busbar is smaller than the width of the tab in the winding direction of the electrode, the busbar can tightly press the tab together, effectively preventing any one of the multiple tabs from prying out of the through-hole in the busbar, thus improving battery reliability. For example, when the busbar is the first busbar, it can tightly press the first tab, effectively preventing any one of the multiple first tabs from prying out of the through-hole in the first busbar, avoiding obstruction of the electrolyte flow path by the first tab, ensuring uniform electrolyte wetting, and improving battery reliability. When the busbar is the second busbar, it can tightly press the second tab, preventing any one of the multiple second tabs from prying out of the through-hole in the second busbar. This avoids abnormal opening caused by the second tab accidentally activating the explosion-proof valve, enhancing battery reliability. Furthermore, since at least two through holes are provided, even if the maximum width of each through hole is less than the width of the second tab, it will not affect the overall pressure relief area of the battery. This allows excess gas generated by a battery malfunction to be smoothly discharged through at least two through holes and the explosion-proof valve at the installation opening, ensuring that the normal pressure relief function of the explosion-proof valve is not affected, thereby further enhancing the safety and reliability of the battery. Attached Figure Description
[0026] To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0027] Figure 1 This is an exploded view of a battery assembly provided in an embodiment of this application;
[0028] Figure 2 This is a schematic diagram of the structure of a core provided in this application;
[0029] Figure 3 yes Figure 2 A top view of the end face of the winding core is shown;
[0030] Figure 4 This is a schematic diagram of the structure of a busbar and cover plate before installation, as provided in an embodiment of this application.
[0031] Figure 5 This is a schematic diagram of another type of core provided in this application;
[0032] Figure 6 This is a schematic diagram of the structure of another busbar and cover plate before installation, provided in an embodiment of this application;
[0033] Figure 7 This is a schematic diagram of the structure of the busbar and cover plate before installation, as provided in another embodiment of this application;
[0034] Figure 8 This is a welding power waveform diagram provided in an embodiment of this application;
[0035] Figure 9 This is another welding power waveform diagram provided in the embodiments of this application. Detailed Implementation
[0036] To make the objectives, technical solutions, and advantages of this application clearer, the embodiments of this application will be described in further detail below with reference to the accompanying drawings.
[0037] In related technologies, batteries typically consist of a metal casing, a core, a busbar, and a cover plate. The core may include stacked positive and negative electrode sheets, and a separator located between the positive and negative electrode sheets. Multiple positive electrode tabs are evenly arranged on one side of the positive electrode sheet, and multiple negative electrode tabs are evenly arranged on the other side of the negative electrode sheet. The multiple positive electrode tabs can be bent and welded to one busbar, and the multiple negative electrode tabs can also be bent and welded to another busbar.
[0038] However, both ends of the battery have openings on the busbars, and one of the multiple positive electrode tabs can easily pry off from the opening of its corresponding busbar. Since the openings on the busbars at the positive electrode tabs are typically used for injecting electrolyte, once the positive electrode tab easily pries off, it obstructs the flow path of the electrolyte, thus affecting the wetting effect and leading to lower battery reliability.
[0039] Similarly, one of the multiple negative electrode tabs can easily pry open from the opening of the corresponding busbar. Since the opening on the busbar at the negative electrode tab is usually used to connect to the explosion-proof valve on the cover, once the negative electrode tab is easily pried out, it may accidentally touch the explosion-proof valve, causing the explosion-proof valve to open abnormally, thus affecting the safety of the battery and resulting in lower battery reliability.
[0040] Please refer to Figure 1 , Figure 1 This is an exploded view of a battery assembly provided in an embodiment of this application. The battery assembly 000 may include: a core 100, a busbar 200, and a cover plate 300.
[0041] The battery assembly 000 may also include a housing 400, which can be used to house the winding core 100.
[0042] To see the structure of core 100 more clearly, please refer to... Figure 2 and Figure 3 , Figure 2 This is a schematic diagram of the structure of a core provided in this application. Figure 3 yes Figure 2 The diagram shows a top view of the end face of the winding core. The winding core 100 in the battery assembly 000 may include: an electrode 102 wound integrally, and a plurality of tabs 101 connected to one side of the electrode, and the plurality of tabs 101 are all capable of being bent in a direction toward the central axis L of the winding core 100.
[0043] To see the structure of the busbar 200 and cover plate 300 more clearly, please refer to... Figure 4 , Figure 4 This is a schematic diagram of the structure of a busbar and cover plate before installation, as provided in an embodiment of this application. The busbar 200 in the battery assembly 000 can be located at one end of the core 100, and the busbar 200 can be welded to at least a portion of the bent tab 101.
[0044] It should be noted that the busbar 200 and the cover plate 300 are connected together and in an unfolded state before installation. The busbar 200 in the battery assembly 000 may include: a connected busbar body 201 and a connecting portion 202; the cover plate 300 can be connected to the connecting portion 202. After the busbar body 201 is welded to at least a portion of the bent tab 101, the connecting portion 202 can be bent so that the cover plate 300 can be located on the side of the busbar body 201 opposite to the core 100.
[0045] The busbar 200 may have at least two through holes C, and the maximum width of each through hole C in the winding direction X of the electrode sheet is less than the width of the tab 101. For example, at least two through holes C may be located on the busbar body 201.
[0046] The cover plate 300 in the battery assembly 000 can be connected to the side of the busbar 200 opposite to the core 100. The cover plate 300 can have a mounting opening K, and the mounting opening K can communicate with at least two through holes C.
[0047] In this configuration, because the maximum width of each through-hole C in the busbar 200 is smaller than the width of the tab 101 in the winding direction X of the electrode sheet, the busbar 200 can tightly press the tab 101a together, effectively preventing one of the multiple tabs from popping out of the through-hole C of the busbar 200, thereby improving the reliability of the battery 000.
[0048] For example, please refer to Figure 5 , Figure 5This is a schematic diagram of another type of core provided in this application. The core 100 can have two pole pieces 102, namely a first pole piece 102a and a second pole piece 102b; wherein, the pole piece connected to the first pole piece 102a is the first pole piece 101a, and the pole piece connected to the second pole piece 102b is the second pole piece 101b.
[0049] Here, one of the first electrode 102a and the second electrode 102b is the positive electrode in the core 102, and the other is the negative electrode in the core 102. This embodiment is illustrated using the example of the first electrode 102a as the positive electrode and the second electrode 102b as the negative electrode.
[0050] The core 102 may further include a diaphragm 102c located between the first electrode 102a and the second electrode 102b, which ensures that the first electrode 102a and the second electrode 102b will not short-circuit. It should be noted that the stacked first electrode 102a and the second electrode 102b, and the diaphragm 102c between them, can be wound together to form the core 102. Here, the plurality of first tabs 101a connected to the first electrode 102a can be evenly arranged at one end of the core 102; the plurality of second tabs 101b connected to the second electrode 102b can be evenly arranged at the other end of the core 102.
[0051] In this configuration, the battery assembly 000 contains two busbars 200, namely a first busbar 210 and a second busbar 220. The first busbar 210 is welded to at least a portion of the bent first tab 101a, allowing the first busbar 210 to be electrically connected to the first electrode 102a via multiple first tabs 101a; the second busbar 220 is welded to at least a portion of the bent second tab 101b, allowing the second busbar 220 to be electrically connected to the second electrode 102b via multiple second tabs 101b.
[0052] The cover plate 300 in the battery assembly 000 may include a first cover plate 301 and a second cover plate 302. The first cover plate 301 may be located on the side of the first busbar 210 opposite to the core 100, and the mounting opening K on the first cover plate 301 may be used for injecting electrolyte; the second cover plate 302 may be located on the side of the second busbar 220 opposite to the core 100, and the mounting opening K on the second cover plate 302 may be used for installing an explosion-proof valve.
[0053] In this embodiment, because the maximum width of each through hole C in the first busbar 210 is smaller than the width of the first tab 101a in the winding direction X of the first electrode 101a, the first busbar 210 can tightly press the first tab 101a, effectively preventing any one of the multiple first tabs 101a from prying out of the through hole C of the first busbar 210. This avoids the first tab 101a obstructing the electrolyte flow path, ensures uniform electrolyte wetting, and improves the reliability of the battery 000.
[0054] Similarly, because the maximum width of each through-hole C in the second busbar 220 is smaller than the width of the second tab 101b in the winding direction X of the second electrode 101b, the second busbar 220 can tightly press the second tab 101b, preventing any one of the multiple second tabs 101b from prying out of the through-hole C of the second busbar 220. This avoids abnormal opening caused by the second tab 101b accidentally triggering the explosion-proof valve, thus enhancing the reliability of the battery.
[0055] Furthermore, since at least two through holes C are provided, even if the maximum width of each through hole C is less than the width of the second tab 101b, it will not affect the overall pressure relief area of the battery. This allows excess gas generated by a battery malfunction to still be discharged smoothly through at least two through holes C and the explosion-proof valve at the installation opening K, ensuring that the normal pressure relief function of the explosion-proof valve is not affected, thereby further enhancing the safety and reliability of the battery.
[0056] In summary, this application provides a battery assembly including a winding core, a busbar, and a cover plate. Since the maximum width of each through-hole in the busbar is smaller than the width of the tab in the winding direction of the electrode sheet, the busbar can tightly press the tab together, effectively preventing any one of the multiple tabs from prying out of the through-hole of the busbar, thereby improving battery reliability. For example, when the busbar is the first busbar, the first busbar can tightly press down on the first tab, effectively preventing any one of the multiple first tabs from prying out of the through-hole of the first busbar, avoiding obstruction of the electrolyte flow path by the first tab, ensuring uniform electrolyte wetting, and improving battery reliability. When the busbar is the second busbar, the second busbar can tightly press down on the second tab, preventing any one of the multiple second tabs from prying out of the through-hole of the second busbar. This avoids abnormal opening caused by the second tab accidentally activating the explosion-proof valve, enhancing battery reliability. Furthermore, since at least two through holes are provided, even if the maximum width of each through hole is less than the width of the second tab, it will not affect the overall pressure relief area of the battery. This allows excess gas generated by a battery malfunction to be smoothly discharged through at least two through holes and the explosion-proof valve at the installation opening, ensuring that the normal pressure relief function of the explosion-proof valve is not affected, thereby further enhancing the safety and reliability of the battery.
[0057] In the embodiments of this application, please refer to Figure 6 , Figure 6 This is a schematic diagram of the structure of the manifold and cover plate before installation, as provided in another embodiment of this application. Each through hole C in the manifold 200 may include: a rectangular area C1 and a fan-shaped area C2 connected to each other, wherein the rectangular area C1 is closer to the outer boundary of the manifold 200 than the fan-shaped area C2.
[0058] In the winding direction X of the electrode sheet, the maximum width of the through hole C in the manifold 200 is the width of the rectangular region C1.
[0059] In this configuration, since the maximum width of the through hole C in the busbar 200 is the width of the rectangular area C1, and the maximum width of each through hole C in the busbar 200 is smaller than the width of the tab 101, the busbar 200 can tightly press the tab 101 in place, effectively preventing the tab 101 from prying out of the rectangular area C1 on the busbar 200. This avoids the tab 101 from abnormally triggering the explosion-proof valve, preventing the explosion-proof valve from opening abnormally, and thus improving the overall safety and reliability of the battery.
[0060] Optional, please refer to Figure 7 , Figure 7 This is a schematic diagram of the structure of the manifold and cover plate before installation, as provided in another embodiment of this application. When there are two through holes C in the manifold 200, the manifold 200 may also have a support strip D located between the two through holes C.
[0061] Among them, the two through holes C are symmetrically distributed on both sides of the center line of the support strip D.
[0062] In this configuration, the tab 101 can be tightly held in place by the support strip D, effectively preventing it from prying out of the through hole C on the busbar 200. This avoids the tab 101 abnormally triggering the explosion-proof valve, preventing its abnormal opening and thus improving the overall safety and reliability of the battery. Furthermore, the symmetrical distribution of the two through holes C on both sides of the support strip D results in a more compact and aesthetically pleasing overall layout.
[0063] In the embodiments of this application, such as Figure 7 As shown, the diameter of the circle containing the fan-shaped region C2 in the through hole C is equal to the sum of the widths d1 of the two rectangular regions C1 in the two through holes C and the width d2 of the support strip D. For example, the diameter of the circle containing the fan-shaped region C2 can be 4.5 mm, the width of the rectangular region C1 can be 1.85 mm, and the width of the support strip D can be 0.8 mm.
[0064] Optionally, within the same through-hole C, the distance between the side of the rectangular region C1 facing away from the fan-shaped region C2 and the outer boundary of the manifold 200 is greater than 0. That is, the rectangular region C1 does not extend to the outermost edge of the manifold 200. For example, the distance between the side of the rectangular region C1 facing away from the fan-shaped region C2 and the outer boundary of the manifold 200 ranges from 0.5 mm to 1.5 mm. For instance, the distance between the side of the rectangular region C1 facing away from the fan-shaped region C2 and the outer boundary of the manifold 200 is 1 mm.
[0065] In this configuration, maintaining a certain distance between the rectangular region C1 and the outer boundary of the busbar 200 makes it more difficult for the tab 101 to warp off the edge of the busbar 200, reducing the risk of tab 101 warping and thus lowering the probability of tab 101 accidentally triggering the explosion-proof valve, significantly improving battery reliability. Furthermore, maintaining a certain distance between the rectangular region C1 and the outer boundary of the busbar 200 enhances the mechanical strength of the busbar 200's edge, preventing cracking or deformation under external pressure or impact, and improving the overall durability and reliability of the busbar 200.
[0066] In this embodiment of the application, the orthographic projection of at least two through holes C in the manifold 200 onto the end face of the core 100 is located within the orthographic projection of the mounting opening K in the cover plate 300 onto the end face of the core 100.
[0067] This design allows excess gas generated by battery malfunctions to be discharged more smoothly through at least two through holes C and the explosion-proof valve at the installation opening K, reducing the resistance that the gas may encounter during discharge and shortening the response time of the explosion-proof valve to ensure timely pressure relief, thereby further enhancing the safety and reliability of the battery.
[0068] It should be noted that the above embodiments use the busbar 200 as an example of the second busbar to illustrate the shape and size of the through holes C provided on the busbar 200. Here, the shape and size of the through holes provided on the first busbar are the same as those on the second busbar. Further details will not be provided here.
[0069] In summary, this application provides a battery assembly including a winding core, a busbar, and a cover plate. Since the maximum width of each through-hole in the busbar is smaller than the width of the tab in the winding direction of the electrode sheet, the busbar can tightly press the tab together, effectively preventing any one of the multiple tabs from prying out of the through-hole of the busbar, thereby improving battery reliability. For example, when the busbar is the first busbar, the first busbar can tightly press down on the first tab, effectively preventing any one of the multiple first tabs from prying out of the through-hole of the first busbar, avoiding obstruction of the electrolyte flow path by the first tab, ensuring uniform electrolyte wetting, and improving battery reliability. When the busbar is the second busbar, the second busbar can tightly press down on the second tab, preventing any one of the multiple second tabs from prying out of the through-hole of the second busbar. This avoids abnormal opening caused by the second tab accidentally activating the explosion-proof valve, enhancing battery reliability. Furthermore, since at least two through holes are provided, even if the maximum width of each through hole is less than the width of the second tab, it will not affect the overall pressure relief area of the battery. This allows excess gas generated by a battery malfunction to be smoothly discharged through at least two through holes and the explosion-proof valve at the installation opening, ensuring that the normal pressure relief function of the explosion-proof valve is not affected, thereby further enhancing the safety and reliability of the battery.
[0070] In related technologies, after multiple tabs are bent along the direction towards the central axis of the core, the number of tab layers gradually decreases from the outer ring to the inner ring of the core. This causes the inner tabs of the core to easily receive excessive welding heat input during laser welding, resulting in the diaphragm in the core being burned by the heat, which may lead to direct contact between the positive and negative electrodes in the core, causing a short circuit risk.
[0071] Therefore, this application provides a welding method. Please refer to... Figure 8 and Figure 9 , Figure 8 This is a welding power waveform diagram provided in an embodiment of this application. Figure 9 This is another welding power waveform diagram provided in the embodiments of this application. During the welding process between the busbar 200 and at least a portion of the bent tab 101, when welding from the inner ring to the outer ring of the core 100, the following can be used: Figure 9The welding process uses a gradually increasing waveform. By progressively increasing the welding power, the inner tab receives a low heat input in the initial stage. As the welding process continues, the power is gradually increased, preventing damage to the separator (not shown) in the core 100 due to excessive heat in the initial stage. When welding from the outer to the inner ring, a gradually decreasing waveform can be used. By progressively decreasing the welding power, the outer tab is welded at a higher power, while the inner tab is welded at a lower power, effectively controlling the heat input to the inner tab and preventing scalding of the separator in the core 100. This gradual increase or decrease in welding power effectively manages the heat input to the inner tab 101 of the core 100, significantly reducing the risk of short circuits caused by weld penetration. This not only improves welding quality but also enhances the safety and reliability of the battery.
[0072] This application embodiment also provides a battery module, which may include: a plurality of interconnected battery components 000, wherein the battery components 000 are any of the aforementioned battery components 000.
[0073] This application also provides a vehicle that may include a battery module, wherein the battery module is the battery module described above.
[0074] In this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. The term "multiple" refers to two or more unless otherwise expressly defined.
[0075] The above description is merely an optional embodiment of this application and is not intended to limit this application. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A battery assembly, characterized in that, The application relates to a winding core (100), a busbar (200) and a cover plate (300). The winding core (100) comprises: a winding-together pole piece and a plurality of pole tabs (101) connected to one side of the pole piece, wherein each of the plurality of pole tabs (101) can be bent in a direction towards a central axis of the winding core (100). The busbar (200) is located at one end of the winding core (100), and the busbar (200) is welded with at least part of the bent pole tabs (101); the busbar (200) has at least two through holes (C), and the maximum width of each of the through holes (C) is smaller than the width of the pole tabs (101) in the winding direction of the pole piece. The cover plate (300) is connected to one side of the busbar (200) away from the winding core (100), and the cover plate (300) has a mounting opening (K) which is in communication with the at least two through holes (C). Each of the through holes (C) comprises a rectangular area (C1) and a sector area (C2) which are connected, and the rectangular area (C1) is closer to the outer boundary of the busbar (200) than the sector area (C2).
2. The battery assembly of claim 1, wherein, In the winding direction of the pole piece, the maximum width of the through hole (C) is the width of the rectangular area (C1). When the number of the through holes (C) in the busbar (200) is two, the busbar (200) further has a support strip (D) located between the two through holes (C).
3. The battery assembly of claim 2, wherein, The two through holes (C) are symmetrically distributed on both sides of the center line of the support strip (D). The diameter of the circle where the sector area (C2) is located is equal to the sum of the width of the two rectangular areas (C1) in the two through holes (C) and the width of the support strip (D).
4. The battery assembly of claim 3, wherein, In the same through hole (C), the distance between one side of the rectangular area (C1) away from the sector area (C2) and the outer boundary of the busbar (200) is greater than 0.
5. The battery assembly of any one of claims 2 to 4, wherein, The orthographic projection of the at least two through holes (C) on the end face of the winding core (100) is located in the orthographic projection of the mounting opening (K) in the cover plate (300) on the end face of the winding core (100).
6. The battery assembly of any one of claims 1 to 4, wherein, The busbar (200) comprises a busbar body (201) and a connecting part (202) which are connected, the at least two through holes (C) are located on the busbar body (201), and the cover plate (300) is connected with the connecting part (202).
7. The battery assembly of any one of claims 1 to 4, wherein, The number of the pole pieces is two, which are a first pole piece and a second pole piece; the pole tabs connected with the first pole piece are first pole tabs, the pole tabs connected with the second pole piece are second pole tabs, and the plurality of first pole tabs and the plurality of second pole tabs are respectively distributed on two ends of the winding core (100).
8. The battery assembly of any one of claims 1 to 4, wherein, The number of the busbars (200) is two, which are a first busbar (210) and a second busbar (220), the first busbar (210) is welded with at least part of the bent first pole tabs, and the second busbar (220) is welded with at least part of the bent second pole tabs. 9. The battery assembly of claim 8, wherein, The cover plate (300) comprises: a first cover plate (301) and a second cover plate (302), the first cover plate (301) is located on the side of the first busbar (210) away from the roll core (100), and a mounting opening (K) on the first cover plate (301) is used for injecting electrolyte; the second cover plate (302) is located on the side of the second busbar (220) away from the roll core (100), and a mounting opening (K) on the second cover plate (302) is used for mounting an explosion-proof valve.
10. A battery module, characterized by Comprising: a plurality of connected battery assemblies, the battery assemblies being any of the battery assemblies of claims 1-9.