Battery cell cover plate assembly, battery cell and battery pack
By adopting welded pole and connecting piece structure in the battery cell cover assembly, the problem of traditional riveting solutions affecting the stability of explosion-proof valves and occupying axial space is solved, and higher assembly efficiency, performance and yield, and higher space utilization are achieved.
Patent Information
- Application Number
- CN202422101539.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-06-17
- Estimated Expiration
- 2034-08-28
AI Technical Summary
In the electrode structure of the battery, the traditional riveting scheme affects the stability of the explosion-proof valve and occupies axial space, resulting in a lower performance and yield of the battery cell.
A battery-core cover assembly is adopted, including a cover plate, a pole column and a connecting piece. The pole column is provided with a first pole column welding rib and the connecting piece is provided with a second pole column welding rib, which replaces the traditional riveting by welding.
This solution reduces riveted parts, improves assembly efficiency and performance, avoids the impact of the instantaneous impact force generated by riveting on the explosion-proof valve, improves yield, reduces the axial space occupied, and improves space utilization.
Smart Images
Figure CN222995557U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a cell cover plate assembly, a cell and a battery pack. Background Art
[0002] With the increasing maturity of lithium-ion battery technology, lithium-ion batteries are widely used as power batteries in the field of electric vehicles.
[0003] The electrode structure of the battery is generally that a cover plate and a pole post are riveted and then welded to a connecting piece.
[0004] In this traditional riveting scheme, due to the instantaneous impact force during riveting, the stability of the explosion-proof valve is seriously affected. Also, due to the existence of the riveting block, the axial space is seriously occupied, the space utilization rate is low, resulting in low performance and yield of the cell. Summary of the Utility Model
[0005] In view of this, the utility model provides a cell cover plate assembly, a cell and a battery pack to solve the problems that the riveting scheme affects the stability of the explosion-proof valve and occupies the axial space.
[0006] In a first aspect, the utility model provides a cell cover plate assembly, including a cover plate, a pole post and a connecting piece. The pole post is arranged on the cover plate. The pole post includes a pole post body and a first pole post welding rib arranged on the pole post body. The inner surface of the first pole post welding rib is recessed from the inner surface of the pole post body, and the outer surface of the first pole post welding rib is recessed from the outer surface of the pole post body. The connecting piece is arranged inside the pole post. The connecting piece includes a connecting piece body, a second pole post welding rib and an ear connecting area. The second pole post welding rib protrudes from the outer surface of the connecting piece body. The ear connecting area is connected to the side of the connecting piece body and is used for welding with the ear of the electrode group. The first pole post welding rib and the second pole post welding rib are in corresponding positions and are welded.
[0007] Beneficial Effects: For the cell cover plate assembly provided by the utility model, the pole post is provided with a first pole post welding rib, and the connecting piece is provided with a second pole post welding rib. The first pole post welding rib and the second pole post welding rib are abutted and welded through penetration. Compared with the traditional technical scheme of using a riveting block for riveting, the utility model provides a new structural combination method, reduces the riveting parts, and only needs to weld the first pole post welding rib and the second pole post welding rib of the pole post, improving the assembly efficiency and performance. The utility model does not require riveting. When an explosion-proof valve is arranged on the cover plate, the stability of the explosion-proof valve will not be affected by the instantaneous impact force generated by riveting, improving the production yield. At the same time, since the riveting block is cancelled, the axial occupied space is reduced, and the space utilization rate is improved.
[0008] In an optional embodiment, the thickness of the first pole post welding rib is T1, and the thickness of the second pole post welding rib is T2, and T1≥T2.
[0009] In an alternative embodiment, 0.8 mm ≤ T2 ≤ 1.8 mm, and T1 + T2 ≥ 2.8 mm.
[0010] In an alternative embodiment, the thickness of the terminal body is T, and the distance between the outer surface of the first terminal welding rib and the outer surface of the terminal body is D, where 0.2T ≤ D ≤ 2T.
[0011] In an alternative embodiment, the distance between the outer surface of the terminal body and the inner surface of the connection piece body is H, where 4.5 mm ≤ H ≤ 5.2 mm.
[0012] In an alternative embodiment, the thickness of the connection piece body is T3, and the thickness of the tab connection area is T4, where T2 ≥ T3 ≥ T4. The inner surface of the tab connection area is recessed from the inner surface of the connection piece body, and 0.2 mm ≤ T4 ≤ 2 mm.
[0013] In an alternative embodiment, the cover plate is provided with a mounting hole. The terminal body of the terminal is disposed at the outer end surface of the mounting hole. Along the axial direction of the mounting hole, at least part of the first terminal welding rib and at least part of the second terminal welding rib are located inside the mounting hole.
[0014] In an alternative embodiment, a combined outer column surface is formed between the terminal body and the connection piece body; the battery cell cover plate assembly further includes an upper plastic, a sealing ring, and a lower plastic sleeved on the combined outer column surface. The upper plastic is located at the outer end surface of the mounting hole, insulatingly connecting the terminal and the cover plate; the sealing ring is located between the mounting hole and the combined outer column surface, sealing the mounting hole; the lower plastic is located at the inner end surface of the mounting hole, insulatingly connecting the connection piece and the cover plate.
[0015] In a second aspect, the present utility model further provides a battery cell, including a housing, an electrode group, and the battery cell cover plate assembly according to any one of the above technical solutions. The housing is provided with an open end; the electrode group is disposed inside the housing, and the electrode group is provided with tabs; the battery cell cover plate assembly is disposed at the open end of the housing, encapsulating the electrode group inside the housing, and the connection piece of the battery cell cover plate assembly is welded to the electrode group.
[0016] Advantageous effects: Since the battery cell includes the battery cell cover plate assembly, it has the same effects as the battery cell cover plate assembly, which will not be elaborated herein.
[0017] In a third aspect, the present utility model further provides a battery pack, including a plurality of the battery cells according to the above technical solutions.
[0018] Advantageous effects: Since the battery pack includes the battery cells, it has the same effects as the battery cells, which will not be elaborated herein. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following will briefly introduce the drawings required for the description of the specific embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.
[0020] Figure 1 Schematic structural diagram of a pole column in an embodiment of the present invention;
[0021] Figure 2 For Figure 1 Top view of the shown pole column;
[0022] Figure 3 For Figure 2 Cross-sectional view taken along A-A in
[0023] Figure 4 Schematic structural diagram of a connecting piece in an embodiment of the present invention;
[0024] Figure 5 For Figure 4 Top view of the shown connecting piece;
[0025] Figure 6 For Figure 5 Cross-sectional view taken along B-B in
[0026] Figure 7 For Figure 1 The structural diagram after the pole column shown in Figure 4 is connected to the shown connecting piece;
[0027] Figure 8 For Figure 7 Top view of
[0028] Figure 9 For Figure 8 Cross-sectional view taken along C-C in
[0029] Figure 10 For Figure 4 The structural diagram after the connecting piece shown in
[0030] Figure 11 For Figure 10 Top view of
[0031] Figure 12 For Figure 11 Cross-sectional view taken along D-D in
[0032] Figure 13 For Figure 12 Enlarged view of the local structure in
[0033] Figure 14 This is a schematic diagram of the structure of a battery cell according to an embodiment of the utility model;
[0034] Figure 15 for Figure 14 A top view of the battery cell shown;
[0035] Figure 16 For along Figure 15 Sectional view at EE;
[0036] Figure 17 for Figure 16 A magnified view of the local structure.
[0037] Description of reference numerals:
[0038] 1. Cover plate; 2. Pole; 21. Pole body; 22. First pole welding rib; 3. Connecting piece; 31. Connecting piece body; 32. Second pole welding rib; 33. Pole ear connection area; 4. Upper plastic; 5. Sealing ring; 6. Lower plastic; 7. Shell; 8. Pole group; 81. Pole ear; 9. Combined outer cylindrical surface. DETAILED DESCRIPTION
[0039] In order to make the purpose, technical solution and advantages of the embodiment of the utility model clearer, the technical solution in the embodiment of the utility model will be clearly and completely described below in conjunction with the drawings in the embodiment of the utility model. Obviously, the described embodiment is a part of the embodiment of the utility model, not all the embodiments. Based on the embodiment of the utility model, all other embodiments obtained by those skilled in the art without creative work are within the scope of protection of the utility model.
[0040] The structural parts of lithium-ion batteries are also an important part of lithium-ion power batteries. They not only provide protection for lithium-ion batteries in terms of safety and reliability, but also take into account the connection between the internal chemical system of lithium-ion batteries and external modules and even the Pack. Since there are various connection relationships inside the structural parts and the requirements of sealing performance and current flow performance need to be taken into account at the same time, the design of the structural parts is particularly important.
[0041] Combine the following Figures 1 to 17 , describing an embodiment of the utility model.
[0042] According to an embodiment of the present utility model, in a first aspect, a cell cover plate assembly is provided, which includes a cover plate 1, a pole column 2, and a connecting piece 3. The pole column 2 is arranged on the cover plate 1. The pole column 2 includes a pole column body 21 and a first pole column welding rib 22 arranged on the pole column body 21. The inner surface of the first pole column welding rib 22 is recessed from the inner surface of the pole column body 21, and the outer surface of the first pole column welding rib 22 is recessed from the outer surface of the pole column body 21. The connecting piece 3 is arranged inside the pole column 2. The connecting piece 3 includes a connecting piece body 31, a second pole column welding rib 32, and a tab connecting area 33. The second pole column welding rib 32 protrudes from the outer surface of the connecting piece body 31. The tab connecting area 33 is connected to the side of the connecting piece body 31 and is used for welding with the tab 81 of the electrode group 8. The first pole column welding rib 22 and the second pole column welding rib 32 are in corresponding positions and are welded together.
[0043] In the cell cover plate assembly provided by the embodiment of the present utility model, the first pole column welding rib 22 is provided on the pole column 2, and the second pole column welding rib 32 is provided on the connecting piece 3. The first pole column welding rib 22 and the second pole column welding rib 32 are abutted and welded through. Compared with the traditional technical solution of riveting with a riveting block, the present utility model provides a new structural combination method, reduces the number of riveting parts, and only needs to weld the first pole column welding rib 22 and the second pole column welding rib 32 of the pole column 2, improving the assembly efficiency and performance. The present utility model does not require riveting. When an explosion-proof valve is provided on the cover plate 1, the stability of the explosion-proof valve will not be affected by the instantaneous impact force generated by riveting, improving the production yield. At the same time, since the riveting block is cancelled, the axial occupied space is reduced, and the space utilization rate is improved.
[0044] It should be noted that in this article, the inner surface refers to that in the state where the cell cover plate assembly is assembled to the housing 7 of the cell, the surface or end face of each component facing the electrode group 8 is the inner surface or inner end face, and the surface or end face of each component away from the electrode group 8 is the outer surface or outer end face. Specifically, in Figure 6 , the inner surface of the connecting piece body 31 is shown as the lower surface of the connecting piece body 31, and the outer surface of the connecting piece body 31 is shown as the upper surface of the connecting piece body 31.
[0045] In some embodiments, the thickness of the first pole column welding rib 22 is T1, and the thickness of the second pole column welding rib 32 is T2, where T1 ≥ T2.
[0046] With such a setting, the stability of the mating surface of the first pole column welding rib 22 and the second pole column welding rib 32 can be ensured, the welding consistency can be guaranteed, and thus the production yield of the cell can be improved.
[0047] In some embodiments, 0.8 mm ≤ T2 ≤ 1.8 mm, and T1 + T2 ≥ 2.8 mm.
[0048] Specifically, when the thickness T2 of the second pole post welding rib 32 is greater than 1.8 mm, the welding power will be too high, and defects such as explosion points and pores are likely to occur. When the thickness T2 of the second pole post welding rib 32 is less than 0.8 mm, the strength of the second pole post welding rib 32 will be insufficient, and thermal deformation is likely to occur during welding, affecting the welding reliability. Therefore, controlling the thickness T2 of the second pole post welding rib 32 within the range of 0.8 mm to 1.8 mm, and the thickness T1 of the first pole post welding rib 22 being greater than the thickness T2 of the second pole post welding rib 32, and at the same time, T1 + T2 ≥ 2.8 mm, can ensure the welding strength and welding reliability of both, thereby improving the production yield of the battery cell.
[0049] In some embodiments, the thickness of the pole post body 21 is T, and the distance between the outer surface of the first pole post welding rib 22 and the outer surface of the pole post body 21 is D, where 0.2T ≤ D ≤ 2T.
[0050] Specifically, the thickness T of the pole post body 21 should be greater than or equal to 2 mm, which can ensure the strength of the pole post body 21 and prevent the heat generated during the welding of the bus bar to the pole post 2 from radiating to the upper plastic 4 and causing deformation or melting of the upper plastic 4, thus ensuring the safety performance of the battery cell.
[0051] The minimum distance D between the outer surface of the first pole post welding rib 22 and the outer surface of the pole post body 21 does not exceed 0.2T. In this way, it can prevent the weld marks of the first pole post welding rib 22 and the second pole post welding rib 32 from protruding from the pole post body 21 and affecting the bus bar welding.
[0052] In some embodiments, the distance between the outer surface of the pole post body 21 and the inner surface of the connection piece body 31 is H, where 4.5 mm ≤ H ≤ 5.2 mm.
[0053] With such a setting, the strength of the pole post 2 and the connection piece 3 can be ensured. At the same time, in the traditional riveting scheme, the distance between the outer surface of the pole post and the inner surface of the area of the connection piece used to connect the pole post is in the range of 6.2 mm to 7.4 mm. In contrast, in this embodiment, the maximum distance between the outer surface of the pole post body 21 and the inner surface of the connection piece body 31 is 5.2 mm, which can significantly reduce the axially occupied space.
[0054] In some embodiments, the thickness of the connection piece body 31 is T3, and the thickness of the tab connection area 33 is T4, where T2 ≥ T3 ≥ T4, the inner surface of the tab connection area 33 is recessed from the inner surface of the connection piece body 31, and 0.2 mm ≤ T4 ≤ 2 mm.
[0055] With such a setting, the thickness T2 of the second pole post welding rib 32, the thickness T3 of the connection piece body 31, and the thickness T4 of the tab connection area 33 decrease in sequence, which can reduce the overall axially occupied space of the pole post 2 and the connection piece 3.
[0056] The tab connection area 33 is used for welding with the electrode group 8, thereby guiding the current inside the battery to the outside.
[0057] By controlling the thickness T4 of the tab connection area 33 within the range of 0.2 mm to 2 mm, the welding strength between the tab connection area 33 and the tab 81 can be ensured. At the same time, the space occupied by the connecting piece 3 and the terminal post 2 as a whole along the axial direction is reduced.
[0058] In some embodiments, the cover plate 1 is provided with a mounting hole. The terminal post body 21 of the terminal post 2 is arranged at the outer end face of the mounting hole. Along the axial direction of the mounting hole, at least part of the first terminal post welding rib 22 and at least part of the second terminal post welding rib 32 are located inside the mounting hole.
[0059] With such an arrangement, the terminal post 2 and the connecting piece 3 are limited within the mounting hole of the cover plate 1, ensuring the stable connection of the cover plate 1, the terminal post 2 and the connecting piece 3.
[0060] In some embodiments, a combined outer cylindrical surface 9 is formed between the terminal post body 21 and the connecting piece body 31; the battery cell cover plate assembly further includes an upper plastic 4, a sealing ring 5 and a lower plastic 6 sleeved on the combined outer cylindrical surface 9. The upper plastic 4 is located at the outer end face of the mounting hole, insulatingly connecting the terminal post 2 and the cover plate 1; the sealing ring 5 is located between the mounting hole and the combined outer cylindrical surface 9, sealing the mounting hole; the lower plastic 6 is located at the inner end face of the mounting hole, insulatingly connecting the connecting piece 3 and the cover plate 1.
[0061] Specifically, the upper plastic 4 and the terminal post 2 are inserted from the outside of the cover plate 1, the sealing ring 5, the lower plastic 6 and the connecting piece 3 are assembled from the inside of the cover plate 1, and then the terminal post 2 and the connecting piece 3 are connected by laser welding.
[0062] During welding, first, the connecting piece 3 and the tab 81 of the electrode group 8 are welded, and then the connecting piece 3 and the terminal post 2 are welded.
[0063] In some embodiments, the terminal post 2 includes a negative terminal post and a positive terminal post.
[0064] The positive terminal post is made of aluminum. Correspondingly, the connecting piece 3 connected to the positive terminal post is also made of aluminum.
[0065] The negative terminal post is made of copper. Correspondingly, the connecting piece 3 connected to the negative terminal post is also made of copper.
[0066] Furthermore, regardless of whether it is positive or negative, the structures of the terminal post 2 and the connecting piece 3 can be formed in one step by stamping, without secondary processing, with simple structures and low costs.
[0067] According to an embodiment of the present utility model, in a second aspect, a battery cell is further provided, which includes a housing 7, an electrode assembly 8, and a battery cell cover plate assembly according to any one of the above technical solutions. The housing 7 is provided with an open end; the electrode assembly 8 is disposed inside the housing 7, and the electrode assembly 8 is provided with electrode tabs 81; the battery cell cover plate assembly is disposed at the open end of the housing 7 to encapsulate the electrode assembly 8 inside the housing 7, and the connecting piece 3 of the battery cell cover plate assembly is welded to the electrode assembly 8.
[0068] Since the battery cell includes the battery cell cover plate assembly and has the same effects as the battery cell cover plate assembly, they will not be elaborated here.
[0069] According to an embodiment of the present utility model, in a third aspect, a battery pack is further provided, which includes a plurality of battery cells according to the above technical solutions.
[0070] Since the battery pack includes battery cells and has the same effects as the battery cells, they will not be elaborated here.
[0071] Although the embodiments of the present utility model have been described in conjunction with the accompanying drawings, those skilled in the art can make various modifications and variations without departing from the spirit and scope of the present utility model, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A battery cover assembly, characterized in that: include: Cover plate; A pole, the pole is arranged on the cover plate, the pole comprises a pole body and a first pole welding rib arranged on the pole body, the inner surface of the first pole welding rib is recessed in the inner surface of the pole body, and the outer surface of the first pole welding rib is recessed in the outer surface of the pole body; A connecting piece, the connecting piece is arranged on the inner side of the pole, the connecting piece includes a connecting piece body, a second pole welding rib and a pole lug connection area, the second pole welding rib is protrudingly arranged on the outer surface of the connecting piece body, the pole lug connection area is connected to the side of the connecting piece body, and is used for welding with the pole lug of the pole group; the first pole welding rib and the second pole welding rib are positioned correspondingly and welded.
2. The battery cover assembly according to claim 1, characterized in that: The thickness of the first pole welding rib is T1, the thickness of the second pole welding rib is T2, and T1≥T2.
3. The battery cover assembly according to claim 2, characterized in that: 0.8mm≤T2≤1.8mm, T1+T2≥2.8mm.
4. The battery cover assembly according to claim 2 or 3, characterized in that: The thickness of the pole body is T, the distance between the outer surface of the first pole welding rib and the outer surface of the pole body is D, and 0.2T≤D≤2T.
5. The battery cell cover plate assembly according to any one of claims 1 to 3, characterized in that: The distance between the outer surface of the pole body and the inner surface of the connecting piece body is H, 4.5 mm≤H≤5.2 mm.
6. The battery cell cover plate assembly according to any one of claims 1 to 3, characterized in that: The thickness of the connecting piece body is T3, the thickness of the tab connection area is T4, T2≥T3≥T4, the inner surface of the tab connection area is recessed in the inner surface of the connecting piece body, and 0.2mm≤T4≤2mm.
7. The battery cell cover plate assembly according to any one of claims 1 to 3, characterized in that: The cover plate is provided with a mounting hole, the pole body of the pole is arranged on the outer end surface of the mounting hole, and along the axial direction of the mounting hole, at least part of the first pole welding rib and at least part of the second pole welding rib are located in the mounting hole.
8. The battery cover assembly according to claim 7, characterized in that: A combined outer cylindrical surface is formed between the pole body and the connecting piece body; The cell cover assembly also includes: An upper plastic, the upper plastic being located on the outer end surface of the mounting hole and insulating and connecting the pole and the cover plate; A sealing ring, the sealing ring is located between the mounting hole and the combined outer cylindrical surface to seal the mounting hole; The lower plastic is located on the inner end surface of the mounting hole and insulates and connects the connecting piece and the cover plate.
9. A battery cell, characterized in that: include: a housing having an open end; A pole group, the pole group is arranged in the shell, and the pole group is provided with pole ears; The battery cell cover plate assembly according to any one of claims 1 to 8, wherein the battery cell cover plate assembly is arranged at the open end of the shell, the electrode group is encapsulated in the shell, and the connecting piece of the battery cell cover plate assembly is welded to the electrode group.
10. A battery pack, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 9.