Battery cell and battery pack
By designing the electrodes in the battery cell to pass through the mounting holes of the connecting piece, only one bending and welding is required to bend and weld, the problems of complex processes and low production efficiency of the traditional battery cell are solved, and more efficient production and higher energy density are achieved.
Patent Information
- Application Number
- CN202422106491.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-08-28
- Publication Date
- 2025-06-13
- Estimated Expiration
- 2034-08-28
AI Technical Summary
There are many welding and bending processes for traditional battery cells in the electrode ears and connecting sheets, and the processes are complex, resulting in low production efficiency and large space occupancy.
A battery cell is designed in which the electrode ears only need to be bent once after passing through the mounting holes of the connecting piece, and then welding can achieve fixed and conductive connections, simplifying the welding and bending process.
By reducing welding and bending processes, the production efficiency of the battery cell is improved and the space occupied is reduced, which is conducive to improving the energy density and packaging rate of the battery cell.
Smart Images
Figure CN222980642U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of batteries, in particular to a battery 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 connecting piece in the battery cell plays a role in conducting the electric energy of the electrode group to the electrode terminal. During the assembly process of the battery cell, it is necessary to weld the connecting piece and the electrode tab of the electrode group.
[0004] In the traditional battery cell solution, the electrode tab and the connecting piece need to be bent multiple times before welding. The welding of the connecting piece and the electrode group and the bending process of the connecting piece have many processes, complex processes, low production efficiency, and large occupied space. Summary of the Utility Model
[0005] In view of this, the utility model provides a battery cell and a battery pack to solve the problems of more welding and bending processes between the electrode group and the connecting piece, complex processes, low production efficiency, and large occupied space.
[0006] In a first aspect, the utility model provides a battery cell, including a cover plate assembly, an electrode group, and two connecting pieces. The cover plate assembly includes a cover plate and electrode terminals arranged on the cover plate. The electrode terminals include a positive electrode terminal and a negative electrode terminal. The cover plate is provided with two welding through holes; one end surface of the electrode group is provided with four electrode tabs corresponding to each welding through hole. The electrode tab includes a root connected to the electrode group and a bending part connected to the root. The root and the bending part are arranged at an angle; each connecting piece corresponds to and connects one electrode terminal. The connecting piece includes an electrode terminal connecting part and an electrode tab connecting part. The electrode terminal connecting part is welded to one electrode terminal. The electrode tab connecting part is provided with two mounting holes for the electrode tabs to pass through; the root of the electrode tab is arranged in the mounting hole, and the bending part is arranged on the outer surface of the electrode tab connecting part and is welded to the electrode tab connecting part.
[0007] Beneficial effects: For the battery cell provided by the utility model, after the electrode tab passes through the mounting hole of the connecting piece, only one bending is required, and then welding can be carried out to realize the fixation and conductive connection of the electrode tab and the connecting piece, saving the welding and bending processes, simplifying the assembly process, greatly improving the production efficiency of the battery cell, and at the same time, reducing the occupied space, which is beneficial to improving the energy density and packaging and grouping rate of the battery cell.
[0008] In an optional embodiment, the four electrode tabs are grouped in pairs. The roots of the two electrode tabs in the same group are located in the same mounting hole, and the bending directions of the bending parts of the two electrode tabs in the same group are opposite.
[0009] In an optional embodiment, the included angle between the bending part and the root is 90°.
[0010] In an alternative embodiment, the length of the mounting hole is L 1 , and the length of the tab is L 2 , L 1 ≥L 2 .
[0011] In an alternative embodiment, the mounting hole penetrates through the side of the tab connecting portion along the length direction thereof to form a groove-shaped structure with an opening.
[0012] In an alternative embodiment, the thickness of the terminal connecting portion is T 1 , 0.8 mm ≤ T 1 ≤ 1.5 mm.
[0013] In an alternative embodiment, the thickness of the tab connecting portion is T 2 , T 2 ≥ 1.5 mm.
[0014] In an alternative embodiment, the tab connecting portion includes two first welding zones located on both sides and a second welding zone located between the two mounting holes. The width of the first welding zone is W 1 , the width of the second welding zone is W 2 , the width of the bending portion is W 3 , W 1 ≥W 3 , W 2 ≥ 2W 3 .
[0015] In an alternative embodiment, the width of the mounting hole is W 4 , W 4 ≥ 5 mm.
[0016] In a second aspect, the present utility model further provides a battery pack, including the battery cell according to any one of the above technical solutions.
[0017] Beneficial effects: Since the battery pack includes the battery cell, it has the same effects as the battery cell, which will not be elaborated here. BRIEF DESCRIPTION OF THE DRAWINGS
[0018] In order to more clearly illustrate the specific embodiments of the present utility model 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 following drawings are some embodiments of the present utility model. For those of ordinary skill in the art, other drawings can be obtained based on these drawings without creative efforts.
[0019] Figure 1 FIG. is a schematic structural diagram of a connecting piece in a battery cell according to an embodiment of the present utility model;
[0020] Figure 2 is Figure 1 the top view of the connecting piece shown;
[0021] Figure 3 is Figure 2 the sectional view taken along A-A in
[0022] Figure 4 the structural schematic diagram of the tab and the connecting piece in the first assembled state;
[0023] Figure 5 the structural schematic diagram of the tab and the connecting piece in the second assembled state;
[0024] Figure 6 is Figure 5 the top view of
[0025] Figure 7 is Figure 6 the sectional view taken along B-B in
[0026] Figure 8 is Figure 7 the enlarged view of the local structure in
[0027] Figure 9 the structural schematic diagram of a battery cell in an assembled state according to an embodiment of the present utility model;
[0028] Figure 10 the structural schematic diagram of a battery cell according to an embodiment of the present utility model in another assembled state;
[0029] Figure 11 is Figure 10 the top view of
[0030] Figure 12 is Figure 11 the sectional view taken along C-C in
[0031] Figure 13 is Figure 12 the enlarged view of the local structure in
[0032] Explanation of reference numerals:
[0033] 1. Cover plate; 11. Welding through hole; 2. Terminal; 3. Electrode group; 31. Tab; 311. Root; 312. Bent part; 313. Transition part; 4. Connecting piece; 41. Terminal connecting part; 42. Tab connecting part; 421. Mounting hole; 422. First welding zone; 423. Second welding zone; 5. Sealing plate; 6. Upper plastic; 7. Sealing ring; 8. Lower plastic; 9. Explosion-proof valve; 10. Housing. Detailed implementation manners
[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present utility model clearer, the technical solutions in the embodiments of the present utility model will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present utility model. Apparently, the described embodiments are some, but not all, of the embodiments of the present utility model. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present utility model without creative efforts shall fall within the protection scope of the present utility model.
[0035] The embodiments of the present utility model will be described below in conjunction with Figures 1 to 13 , which describes the embodiments of the present utility model.
[0036] According to an embodiment of the present utility model, on the one hand, a battery cell is provided, which includes a cover plate assembly, a pole group 3, and two connecting pieces 4. The cover plate assembly includes a cover plate 1 and pole posts 2 provided on the cover plate 1. The pole posts 2 include a positive pole post and a negative pole post. The cover plate 1 is provided with two welding through holes 11; on one end face of the pole group 3, four pole tabs 31 are correspondingly arranged for each welding through hole 11. The pole tabs 31 include a root portion 311 connected to the pole group 3 and a bent portion 312 connected to the root portion 311. The root portion 311 and the bent portion 312 are arranged at an angle; each connecting piece 4 is correspondingly connected to one pole post 2. The connecting piece 4 includes a pole post connecting portion 41 and a pole tab connecting portion 42. The pole post connecting portion 41 is welded to one pole post 2. The pole tab connecting portion 42 is provided with two mounting holes 421 for the pole tabs 31 to pass through; the root portion 311 of the pole tab 31 is arranged in the mounting hole 421, and the bent portion 312 is arranged on the outer surface of the pole tab connecting portion 42 of the connecting piece 4 and is welded to the pole tab connecting portion 42 of the connecting piece 4.
[0037] For the battery cell provided by the embodiment of the present utility model, since two welding through holes 11 are provided on the cover plate 1, and the positions of the welding through holes 11 correspond to the positions of two groups of pole tabs (four in each group) of the pole group 3, the pole tabs 31 and the connecting pieces 4 can be welded through the welding through holes 11. Since two welding through holes 11 are provided on the cover plate 1 and the two welding through holes 11 are spaced apart, the portion of the cover plate 1 between the two welding through holes 11 is still connected and not disconnected, ensuring the integrity of the cover plate 1 and being able to ensure the strength of the cover plate 1 itself.
[0038] Since the connecting piece 4 is provided with the mounting holes 421, when assembling the pole tabs 31 and the connecting pieces 4, the pole tabs 31 can vertically pass through the mounting holes 421 and then be bent to form the bent portions 312. The bent portions 312 are pressed on the outer surface of the pole tab connecting portion 42 of the connecting piece 4, and the bent portions 312 of the pole tabs 31 and the pole tab connecting portion 42 of the connecting piece 4 are welded.
[0039] For the battery cell provided by the embodiment of the present utility model, after the tab 31 passes through the mounting hole 421 of the connecting piece 4, only one-time bending is required, and then welding can be carried out to realize the fixation and conductive connection of the tab 31 and the connecting piece 4, saving the welding and bending processes, simplifying the assembly process, greatly improving the production efficiency of the battery cell. At the same time, the occupied space is reduced, which is beneficial to improving the energy density and the packing and grouping rate of the battery cell.
[0040] Specifically, laser welding or ultrasonic welding can be adopted between the connecting piece 4 and the tab 31.
[0041] It should be noted that for the outer surface of the tab connecting portion 42, in the state of the battery cell, the surface on the side of the tab connecting portion 42 facing the electrode group 3 is the outer surface.
[0042] In some embodiments, the four tabs 31 are grouped in pairs. The roots 311 of the two tabs 31 in the same group are located in the same mounting hole 421, and the bending portions 312 of the two tabs 31 in the same group are bent in opposite directions.
[0043] By bending the two tabs 31 in the same group in opposite directions, the utilization rate in the width direction of the cover plate 1 can be improved, and the strength of the cover plate 1 can be enhanced.
[0044] In some embodiments, the included angle between the bending portion 312 and the root 311 is 90°.
[0045] Specifically, the tab 31 first passes through the mounting hole 421, and then the four tabs 31 are grouped in pairs. The bending portions 312 of the two tabs 31 in the same group are bent in opposite directions to form the bending portion 312. The included angle between the bending portion 312 of the tab 31 and the root 311 of the tab 31 is 90°, that is, the bending portion 312 of the tab 31 is perpendicular to the root 311 of the tab 31.
[0046] It should be noted that it can be considered perpendicular within the allowable error range.
[0047] In some embodiments, as Figure 2 and Figure 6 shown, the length of the mounting hole 421 is L 1 , the length of the tab 31 is L 2 , L 1 ≥L 2 .
[0048] Referring to Figure 2 and Figure 6 , the length of the mounting hole 421 and the width of the tab 31 are both measured along the length direction of the cover plate 1. Since the length L 1 of the mounting hole 421 is greater than or equal to the length L 2, it can ensure that the tab 31 smoothly passes through the mounting hole 421 of the tab connection part 42, reducing the assembly difficulty.
[0049] In some embodiments, the mounting hole 421 penetrates through the side of the tab connection part 42 along the length direction thereof to form a groove-shaped structure with an opening.
[0050] By setting the mounting hole 421 as a groove-shaped structure with an opening, it is convenient for the assembly of the tab 31 and the connecting piece 4, reducing the assembly difficulty and improving the production efficiency.
[0051] In some embodiments, the thickness of the pole connection part 41 is T 1 , 0.8 mm ≤ T 1 ≤ 1.5 mm.
[0052] By controlling the thickness T of the pole connection part 41 1 within the range of 0.8 mm to 1.5 mm, the strength of the pole connection part 41 and the reliability of welding can be ensured.
[0053] In some embodiments, the thickness of the tab connection part 42 is T 2 , T 2 ≥ 1.5 mm.
[0054] The thickness T of the tab connection part 42 2 is at least 1.5 mm. In this way, the strength of the connecting piece 4 itself can be ensured, it will not bend during welding, and it can ensure that the laser does not penetrate the connecting piece 4 when welding the tab 31.
[0055] In some embodiments, as Figure 1 and Figure 2 shown, the tab connection part 42 includes two first welding partitions 422 located on both sides and a second welding partition 423 located between the two mounting holes 421. The width of the first welding partition 422 is W 1 , the width of the second welding partition 423 is W 2 , the width of the bending part 312 is W 3 , W 1 ≥ W 3 , W 2 ≥ 2W 3 .
[0056] Referring to Figure 1 and Figure 2 , the tab connection part 42 is separated into two first welding partitions 422 and a second welding partition 423 by the two mounting holes 421. The bending parts 312 of the two tabs 31 located on both sides are respectively pressed on the two first welding partitions 422. Since the width W 1 of the first welding partition 422 is greater than or equal to the width W 3, in this way, the welding area between the bent portion 312 of the tab 31 and the first welding partition 422 is the largest, ensuring the reliability of welding. Also, the two bent portions 312 located in the middle are bent 90° towards each other and pressed on the second welding partition 423. Since the width W of the second welding partition 423 2 is greater than twice the width of the tab 31, therefore, both the two bent portions 312 and the second welding partition 423 can ensure the maximum welding area, ensuring the reliability of welding. At the same time, with such a structure, the two tabs 31 located in the middle are bent towards each other, which can maximize the utilization rate of the battery in the width direction, minimize the width of the welding through-hole 11 of the cover plate 1, and ensure the strength of the cover plate 1.
[0057] Specifically, in some embodiments, the bent portion 312 of the tab 31 and the root of the tab 31 are connected by a transition portion 313. Generally, the transition portion 313 is a rounded corner.
[0058] In some embodiments, the width of the mounting hole 421 is W 4 , W 4 ≥5mm.
[0059] Since the bending of the tab 31 requires a bending device, and the bending device will occupy space in the width direction, since the width W of the mounting hole 421 4 is at least 5mm, and the width occupied by a general bending device is greater than 1.5mm, in this way, during the bending process, the bending space of the tab 31 can be utilized without the need to open a large avoidance hole.
[0060] In some embodiments, the cell cover plate assembly further includes two sealing plates 5. The sealing plates 5 cooperate with the welding through-holes 11, and the sealing plates 5 are connected to the cover plate 1 to seal the welding through-holes 11.
[0061] By providing the sealing plates 5 and the sealing plates 5 cooperate with the welding through-holes 11, after the tab 31 and the connecting piece 4 are welded, the sealing plates 5 are assembled at the welding through-holes 11 to seal the welding through-holes 11.
[0062] In some embodiments, the cell cover plate assembly further includes an explosion-proof valve 9. The explosion-proof valve 9 is provided on the cover plate 1 and is located between the two welding through-holes 11.
[0063] In some embodiments, the cell cover plate assembly further includes an upper plastic 6, a lower plastic 8 and a sealing ring 7.
[0064] The cover plate 1 is provided with a mounting hole 421, the pole column 2 is arranged in the mounting hole 421, and the upper plastic 6 is arranged between the pole column 2 and the cover plate 1 to insulatively connect the pole column 2 and the cover plate 1.
[0065] The lower plastic 8 is arranged on the inner surface of the cover plate 1 for insulatively connecting the connecting piece 4 and the cover plate 1.
[0066] A sealing ring 7 is disposed between the outer cylindrical surface of the pole column 2 and the inner wall of the mounting hole 421 for sealingly connecting the pole column 2 and the cover plate 1.
[0067] After the cover plate 1, the pole column 2, the upper plastic 6, the sealing ring 7, the lower plastic 8 and the connecting piece 4 are assembled, they form a battery cell cover plate assembly and are supplied in the form of the battery cell cover plate assembly, which is beneficial to improving the production efficiency of the battery cell.
[0068] In some embodiments, the battery cell further includes a housing 10 having a receiving cavity. A pole group 3 is disposed in the receiving cavity. One end of the housing 10 is open, and the cover plate assembly is disposed at the open end of the housing 10 to encapsulate the pole group 3 in the housing 10.
[0069] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including the battery cell of any one of the above technical solutions.
[0070] Since the battery pack includes the battery cell and has the same effects as the battery cell, they will not be described herein again.
[0071] Although the embodiments of the present invention 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 invention, and such modifications and variations all fall within the scope defined by the appended claims.
Claims
1. A battery cell, characterized in that: include: A cover plate assembly, the cover plate assembly comprising a cover plate and poles arranged on the cover plate, the poles comprising a positive pole and a negative pole, and the cover plate is provided with two welding through holes; A pole group, wherein one end surface of the pole group is provided with four pole lugs corresponding to each of the welding through holes, the pole lugs comprising a root connected to the pole group and a bent portion connected to the root, the root and the bent portion being arranged at an angle; Two connecting pieces, each connecting piece is connected to a pole, the connecting piece comprises a pole connecting portion and a pole lug connecting portion, the pole connecting portion is welded to the pole, and the pole lug connecting portion is provided with two mounting holes for the pole lugs to pass through; The root of the pole lug is arranged at the mounting hole, and the bent portion is arranged at the outer surface of the pole lug connecting portion and is welded to the pole lug connecting portion.
2. The battery cell according to claim 1, characterized in that: The four pole tabs are arranged in groups of two, the roots of the two pole tabs in the same group are located in the same mounting hole, and the bending parts of the two pole tabs in the same group have opposite bending directions.
3. The battery cell according to claim 1 or 2, characterized in that: The angle between the bent portion and the root portion is 90°.
4. The battery cell according to claim 1 or 2, characterized in that: The length of the mounting hole is L1, the length of the tab is L2, and L1≥L2.
5. The battery cell according to claim 1 or 2, characterized in that: The mounting hole penetrates through the side of the pole lug connecting portion along the length direction thereof to form a slot-shaped structure with an opening.
6. The battery cell according to claim 1 or 2, characterized in that: The thickness of the pole connecting portion is T1, 0.8 mm ≤ T1 ≤ 1.5 mm.
7. The battery cell according to claim 1 or 2, characterized in that: The thickness of the tab connection portion is T2, where T2≥1.5 mm.
8. The battery cell according to claim 1 or 2, characterized in that: The tab connection portion includes two first welding partitions located on both sides and a second welding partition located between the two mounting holes, the width of the first welding partition is W1, the width of the second welding partition is W2, the width of the bending portion is W3, W1≥W3, W2≥2W3.
9. The battery cell according to claim 1 or 2, characterized in that: The width of the mounting hole is W4, W4≥5mm.
10. A battery pack, characterized in that: The invention comprises a plurality of battery cells according to any one of claims 1 to 9.