Battery cell cover plate assembly, battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell cover plate assembly, a battery cell and a battery pack. The battery cell cover plate assembly comprises a cover plate, a sealing plate and an insulating plate, a welding through hole is formed in the cover plate; the sealing plate is arranged in the welding through hole, an anti-explosion valve mounting hole and a liquid injection hole are formed in the sealing plate, a plurality of injection molding grooves are formed in one surface of the sealing plate, the maximum width of a groove opening of each injection molding groove is smaller than that of the groove bottom of the injection molding groove, and a plurality of barb structures deviating from the first surface are arranged on the inner wall of each injection molding groove; an exhaust channel is formed in the position, corresponding to the explosion-proof valve mounting hole, of the insulating plate; a liquid injection through hole is formed in the position, corresponding to the liquid injection hole, of the insulating plate; an injection molding boss is arranged at the position, corresponding to the sealing plate, of the insulating plate, and the injection molding boss is matched with the injection molding groove; the insulating plate and the sealing plate are in injection molding connection. According to the utility model, the sealing plate and the insulating plate are not easy to fall off under the condition that the temperature of the battery cell is increased during long-time working, so that the sealing performance and the insulating performance of the battery cell are ensured.

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 cell cover plate assembly is an important part of the cell, including structures such as a cover plate, a pole column, a connecting piece, an explosion-proof valve, a liquid injection hole, a sealing plate and an insulating plate.

[0004] Among them, the connecting piece needs to be connected to the pole column and at the same time to the tab of the electrode group. In traditional cells, there are many welding processes for the connecting piece and the tab, which affects the production efficiency of the cell. In addition, the sealing plate plays an important role in the sealing performance and insulation performance of the cell cover plate assembly. In traditional cells, the connection strength between the sealing plate and the insulating plate is low. After the cell works, the temperature rises, which easily causes the connection between the sealing plate and the insulating plate to fall off, thereby affecting the sealing performance and insulation performance 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 there are many welding processes for the connecting piece and the tab, which affects the production efficiency of the cell, and the connection between the sealing plate and the insulating plate is not firm and is prone to detachment.

[0006] In a first aspect, the utility model provides a cell cover plate assembly, including a cover plate, a sealing plate and an insulating plate. The cover plate is provided with a welding through hole; the sealing plate is arranged in the welding through hole. The sealing plate is provided with an explosion-proof valve mounting hole and a liquid injection hole. One surface of the sealing plate is provided with a plurality of injection molding grooves. The maximum width of the notch of the injection molding groove is smaller than the maximum width of its groove bottom. The inner wall of the injection molding groove is provided with a plurality of barbs structures deviating from the first surface; the corresponding position of the insulating plate to the explosion-proof valve mounting hole is provided with an exhaust passage, and the corresponding position of the insulating plate to the liquid injection hole is provided with a liquid injection through hole; the corresponding position of the insulating plate to the sealing plate is provided with an injection molding boss, and the injection molding boss and the injection molding groove cooperate; the insulating plate and the sealing plate are injection-molded and connected.

[0007] Beneficial effects: For the cell cover plate assembly provided by the present utility model, since the sealing plate is provided with an injection molding groove, the sealing plate and the insulating plate are connected by injection molding, and an injection molding boss adapted to the injection molding groove is formed on the insulating plate. The sealing plate and the insulating plate are integrally injection molded, with high connection strength, which can improve the sealing performance of all the joint surfaces of the two connecting parts, make the combination of the injection molding groove and the injection molding boss closer, and achieve a better connection effect. At the same time, the notch size of the injection molding groove is smaller than the size of the bottom of the injection molding groove, so that a limit is formed between the injection molding groove and the injection molding boss. At the same time, a barb structure is provided on the inner wall of the injection molding groove. After injection molding, an inclined groove matching the barb structure will be formed on the injection molding boss. The barb structure plays a role in strengthening the anchoring between the sealing plate and the insulating plate, and can ensure that the sealing plate and the insulating plate are not easily separated even when the cell works for a long time and heats up, thus ensuring the sealing performance and insulating performance of the cell. At the same time, the injection molding groove and the injection molding boss increase the contact surface between the sealing plate and the insulating plate, improve the binding force of the sealing plate on the insulating plate, and improve the sealing performance.

[0008] In an alternative embodiment, the maximum width of the bottom of the injection molding groove is D, and the maximum width of the notch of the injection molding groove is d, and D - d ≥ 0.3 mm.

[0009] In an alternative embodiment, the range of the maximum width D of the bottom of the injection molding groove is: 0.8 mm ≤ D ≤ 6.5 mm, and the range of the maximum width d of the notch of the injection molding groove is: 0.5 mm ≤ d ≤ 6 mm.

[0010] In an alternative embodiment, the depth of the injection molding groove is H, and 0.6 mm ≤ H ≤ 3 mm.

[0011] In an alternative embodiment, the remaining thickness of the sealing plate at the bottom of the injection molding groove is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0012] In an alternative embodiment, the barb structures are arranged at intervals on the inner wall of the injection molding groove. The extension direction of the barb structure and the inner wall of the injection molding groove form an angle α, and the inner wall of the injection molding groove and the first surface form an angle β, and α < β.

[0013] In an alternative embodiment, two groups of injection molding grooves are provided on both sides of the explosion-proof valve mounting hole, and at least two are provided at intervals in each group.

[0014] In an alternative embodiment, it further includes two connecting pieces and two pole columns. The connecting piece includes a pole column connecting part and an ear connecting part. The pole column connecting part is welded to the pole column. The ear connecting parts of the two connecting pieces both extend to the positions corresponding to the welding through holes, and each ear connecting part is welded to the ear of the cell through the welding through hole.

[0015] In a second aspect, the present utility model further provides an electric core, which includes a housing, an electrode assembly, and the electric core cover plate assembly according to any one of the above technical solutions. The housing has an open end; the electrode assembly is disposed inside the housing; the electric core cover plate assembly is disposed at the open end of the housing to encapsulate the electrode assembly inside the housing.

[0016] Beneficial effects: Since the electric core includes the electric core cover plate assembly, it has the same effects as the electric core cover plate assembly, which will not be elaborated herein.

[0017] In a third aspect, the present utility model further provides a battery pack, which includes a plurality of electric cores according to the above technical solutions.

[0018] Beneficial effects: Since the battery pack includes the electric core, it has the same effects as the electric core, which will not be elaborated herein. Description of the Drawings

[0019] 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 use in the description of the specific embodiments or the prior art. Obviously, the drawings in the following description 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.

[0020] Figure 1 It is a schematic structural diagram of a sealing plate and an insulating plate after connection in a first perspective view in an electric core cover plate assembly according to an embodiment of the present utility model;

[0021] Figure 2 For Figure 1 It is a schematic structural diagram in a second perspective view;

[0022] Figure 3 For Figure 1 It is a top view;

[0023] Figure 4 For Figure 3 It is a cross-sectional view taken along line A-A in

[0024] Figure 5 For Figure 4 It is an enlarged view of a partial structure in

[0025] Figure 6 It is a schematic structural diagram of an insulating plate in a first perspective view;

[0026] Figure 7 For Figure 6 It is a schematic structural diagram of the insulating plate shown in a second perspective view;

[0027] Figure 8 It is a schematic diagram of a partial structure of an electric core cover plate assembly according to an embodiment of the present utility model;

[0028] Figure 9 is the top view of Figure 8 ;

[0029] Figure 10 is the sectional view taken along line B-B in Figure 9 ;

[0030] Figure 11 is the enlarged view of the local structure in Figure 10 ;

[0031] Figure 12 is the schematic structural view of the battery cell in the first assembly state;

[0032] Figure 13 is the schematic structural view of the battery cell in the second assembly state;

[0033] Figure 14 is the schematic structural view of the battery cell in the third assembly state;

[0034] Figure 15 is the top view of Figure 14 ;

[0035] Figure 16 is the sectional view taken along line C-C in Figure 15 ;

[0036] Figure 17 is the enlarged view of the local structure in Figure 16 ;

[0037] Description of reference numerals:

[0038] 1. Cover plate; 101. Welding through hole; 2. Sealing plate; 201. Explosion-proof valve mounting hole; 202. Liquid injection hole; 203. Injection molding groove; 2031. Barbed structure; 3. Insulating plate; 301. Exhaust passage; 302. Liquid injection through hole; 303. Injection molding boss; 4. Connecting piece; 401. Terminal connecting part; 402. Tab connecting part; 5. Terminal; 6. Explosion-proof valve; 7. Housing; 8. Electrode group; 801. Tab; 9. Lower plastic. Detailed implementation manners

[0039] 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. Obviously, the described embodiments are some, but not all, of the embodiments of the present utility model. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0040] The following describes the embodiments of the present utility model with reference to Figures 1 to 17 .

[0041] According to an embodiment of the present invention, in a first aspect, a cell cover plate assembly is provided, which includes a cover plate 1, a sealing plate 2, and an insulating plate 3. The cover plate 1 is provided with a welding through hole 101; the sealing plate 2 is disposed in the welding through hole 101, the sealing plate 2 is provided with an explosion-proof valve mounting hole 201 and a liquid injection hole 202, one surface of the sealing plate 2 is provided with a plurality of injection molding grooves 203, the maximum width of the notch of the injection molding groove 203 is smaller than the maximum width of its groove bottom, and the inner wall of the injection molding groove 203 is provided with a plurality of barbs 2031 deviating from the first surface; the corresponding position of the insulating plate 3 to the explosion-proof valve mounting hole 201 is provided with an exhaust passage 301, and the corresponding position of the insulating plate 3 to the liquid injection hole 202 is provided with a liquid injection through hole 302; the corresponding position of the insulating plate 3 to the sealing plate 2 is provided with an injection molding boss 303, and the injection molding boss 303 and the injection molding groove 203 are matched; the insulating plate 3 and the sealing plate 2 are injection-molded and connected.

[0042] In the cell cover plate assembly provided by the embodiment of the present invention, the connecting piece 4 on the positive electrode side is welded to the tab 801 on the positive electrode side, and the connecting piece 4 on the negative electrode side is welded to the tab 801 on the negative electrode side. Since only one welding through hole 101 is provided on the cover plate 1, through this welding through hole 101, the welding work of the tabs 801 on the positive electrode side and the negative electrode side can be completed. The welding process is continuous, the welding process can be reduced, and the production efficiency of the cell can be improved.

[0043] In the cell cover plate assembly provided by the embodiment of the present invention, since the injection molding groove 203 is provided on the sealing plate 2, and the sealing plate 2 and the insulating plate 3 are injection-molded and connected, an injection molding boss 303 adapted to the injection molding groove 203 is formed on the insulating plate 3. The sealing plate 2 and the insulating plate 3 are integrally injection-molded, and the connection strength is high, which can improve the sealing performance of all the joint surfaces of the two connecting parts, make the combination of the injection molding groove 203 and the injection molding boss 303 closer, and achieve a better connection effect. At the same time, the notch size of the injection molding groove 203 is smaller than the size of the groove bottom of the injection molding groove 203, so that a limit is formed between the injection molding groove 203 and the injection molding boss 303. At the same time, barbs 2031 are provided on the inner wall of the injection molding groove 203. After injection molding, an inclined groove matching the barbs 2031 will be formed on the injection molding boss 303. The barbs 2031 play a role in strengthening the anchoring between the sealing plate 2 and the insulating plate 3, which can ensure that the sealing plate 2 and the insulating plate 3 are not easily separated even when the cell works for a long time and heats up, thereby ensuring the sealing performance and insulating performance of the cell. At the same time, the injection molding groove 203 and the injection molding boss 303 increase the contact surface between the sealing plate 2 and the insulating plate 3, improve the binding force of the sealing plate 2 on the insulating plate 3, and improve the sealing performance.

[0044] The cell cover assembly provided by the embodiment of the present utility model. Since the sealing plate 2 is provided with an explosion-proof valve mounting hole 201, and an exhaust passage 301 is provided at the corresponding position of the insulating plate 3 to the explosion-proof valve mounting hole 201. In this way, an explosion-proof valve 6 is installed on the explosion-proof valve mounting hole 201 of the sealing plate 2, and the gas generated inside the cell can reach the explosion-proof valve 6 through the exhaust passage 301 of the insulating plate 3, realizing pressure relief and improving the safety performance of the cell. Specifically, in this embodiment, the exhaust passage 301 of the insulating plate 3 includes a plurality of exhaust through holes. Further, the cell cover assembly further includes a lower plastic 9, the lower plastic 9 is disposed on the lower surface of the cover plate 1, the lower plastic 9 is provided with an exhaust cavity, and the positions of the explosion-proof valve mounting hole 201 of the sealing plate 2 and the exhaust passage 301 of the insulating plate 3 correspond to each other.

[0045] The cell cover assembly provided by the embodiment of the present utility model. Since the sealing plate 2 is provided with a liquid injection hole 202, and a liquid injection through hole 302 is provided at the corresponding position of the insulating plate 3 to the liquid injection hole 202, and the liquid injection through hole 302 is communicated with the liquid injection hole 202 for injecting electrolyte into the cell. Because the welding through hole 101 occupies a relatively large space on the cover plate 1, and by arranging both the explosion-proof valve mounting hole 201 and the liquid injection hole 202 on the sealing plate 2, the structure of the sealing plate 2 can be fully utilized to optimize the structural layout of the cover plate 1, making the structure more compact and reducing the space occupied by the cover plate 1 in the length direction.

[0046] Specifically, the first surface of the sealing plate 2 is the surface of the sealing plate 2 facing the cover plate 1. In the state of a complete cell, the first surface of the sealing plate 2 is the surface facing the electrode group 8, and in Figure 17 it is shown as its lower surface.

[0047] In some embodiments, the maximum width of the bottom of the injection molding groove 203 is D, the maximum width of the opening of the injection molding groove 203 is d, and D - d ≥ 0.3 mm.

[0048] Since the maximum width of the opening of the injection molding groove 203 is smaller than the maximum width of the bottom of the injection molding groove 203, therefore, a non-detachable and firm connection effect between the insulating plate 3 and the sealing plate 2 can be achieved. By controlling the difference between the maximum width D of the bottom of the injection molding groove 203 and the maximum width d of the opening of the injection molding groove 203 within a range of at least 0.3 mm, a good non-detachable effect between the injection molding groove 203 and the injection molding boss 303 can be ensured.

[0049] In some embodiments, the range of the maximum width D of the bottom of the injection molding groove 203 is: 0.8 mm ≤ D ≤ 6.5 mm, and the range of the maximum width d of the opening of the injection molding groove 203 is: 0.5 mm ≤ d ≤ 6 mm.

[0050] By controlling the maximum width D of the bottom of the injection molding groove 203 within the range of 0.8 mm to 6.5 mm and the maximum width d of the opening of the injection molding groove 203 within the range of 0.5 mm to 6 mm, the connection strength and injection molding efficiency between the sealing plate 2 and the insulating plate 3 can be ensured, thereby ensuring the sealing performance and insulating performance of the battery cell and improving the production efficiency of the battery cell.

[0051] In some embodiments, the depth of the injection molding groove 203 is H, and 0.6 mm ≤ H ≤ 3 mm.

[0052] By controlling the depth H of the injection molding groove 203 within the range of 0.6 mm to 3 mm, the connection strength and injection molding efficiency between the sealing plate 2 and the insulating plate 3 can be ensured, thereby ensuring the sealing performance and insulating performance of the battery cell and improving the production efficiency of the battery cell.

[0053] In some embodiments, the remaining thickness of the sealing plate 2 at the bottom of the injection molding groove 203 is t, and 0.2 mm ≤ t ≤ 1.5 mm.

[0054] Since the injection molding groove 203 is provided on the sealing plate 2, the remaining part of the sealing plate 2 at the bottom of the injection molding groove 203 is relatively thin. The remaining thickness t of the sealing plate 2 here is at least 0.2 mm, which can ensure the strength of the sealing plate 2 here and ensure that the sealing plate 2 is not easily deformed. The remaining thickness t of the sealing plate 2 here is at most 1.5 mm, which can ensure that the overall thickness of the sealing plate 2 is not too large and ensure that the sealing plate 2 does not occupy too much space in the thickness direction of the cover plate 1.

[0055] In some embodiments, as Figure 5 shown, the barb structures 2031 are arranged at intervals on the inner wall of the injection molding groove 203. The extension direction of the barb structures 2031 forms an angle α with the inner wall of the injection molding groove 203, and the inner wall of the injection molding groove 203 forms an angle β with the first surface, and α < β.

[0056] With such a setting, it can be ensured that the extension direction of the barb structures 2031 is always inclined away from the first surface. While playing the role of anchoring and anti - detachment between the sealing plate 2 and the insulating plate 3, it is convenient for injection molding and improves the injection molding efficiency.

[0057] In some embodiments, the injection molding boss 303 is a frustum - of - a - cone - inverted structure or a frustum - of - a - pyramid - inverted structure.

[0058] In this embodiment, the injection molding boss 303 is an inverted frustum - of - a - cone structure. At this time, D is the diameter of the bottom of the injection molding groove 203, and d is the diameter of the opening of the injection molding groove 203.

[0059] Certainly, in some other embodiments, the injection molding boss 303 has an inverted frustum structure, D is the maximum diagonal dimension of the bottom of the injection molding groove 203, and d is the maximum diagonal dimension of the notch of the injection molding groove 203.

[0060] In some embodiments, two sets of injection molding grooves 203 are provided on both sides of the explosion-proof valve mounting hole 201, and at least two are provided at intervals in each set.

[0061] Since the sealing plate 2 has a rectangular structure, by dispersedly arranging a plurality of injection molding grooves 203, it is possible to ensure that the overall connection strength of the sealing plate 2 and the insulating plate 3 is strong everywhere. In this embodiment, four injection molding grooves 203 are arranged at intervals in each set, and the four injection molding grooves 203 are distributed in a matrix.

[0062] In some embodiments, it further includes two connecting pieces 4 and two pole columns 5. The connecting piece 4 includes a pole column connecting portion 401 and an ear connecting portion 402. The pole column connecting portion 401 is welded to the pole column 5. The ear connecting portions 402 of the two connecting pieces 4 both extend to the positions corresponding to the welding through holes 101, and each ear connecting portion 402 is welded to the ear 801 of the battery cell through the welding through hole 101.

[0063] Through one welding through hole 101, it is possible to weld the ear connecting portion 402 of the connecting piece 4 on the positive electrode side and the ear 801 on the positive electrode side, and to weld the ear connecting portion 402 of the connecting piece 4 on the negative electrode side and the ear 801 on the negative electrode side. Specifically, in this embodiment, two ears 801 are provided corresponding to each pole column 5 in the pole group 8. The two ears 801 extend from both sides of the ear connecting portion 402 of the connecting piece 4, are bent by 90°, pressed on the upper surface of the ear connecting portion 402, and then the ear 801 and the ear connecting portion 402 of the connecting piece 4 are welded. This setting improves the space utilization rate inside the battery, reduces the welding process between the connecting piece 4 and the pole group 8 and the bending process of the connecting piece 4, and improves the production efficiency.

[0064] According to an embodiment of the present invention, in a second aspect, a battery cell is further provided, including a housing 7, a pole group 8, and the battery cell cover assembly according to any one of the above embodiments. The housing 7 has an open end; the pole group 8 is disposed inside the housing 7; the battery cell cover assembly is disposed at the open end of the housing 7 to encapsulate the pole group 8 inside the housing 7.

[0065] Since the battery cell includes the battery cell cover assembly and has the same effects as the battery cell cover assembly, it will not be elaborated here.

[0066] According to an embodiment of the present invention, in a third aspect, a battery pack is further provided, including a plurality of battery cells according to the above embodiments.

[0067] Since the battery pack includes the battery cell and has the same effects as the battery cell, it will not be elaborated here.

[0068] Although 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: A cover plate, wherein the cover plate is provided with a welding through hole; A sealing plate, the sealing plate is arranged at the welding through hole, the sealing plate is provided with an explosion-proof valve mounting hole and a liquid injection hole, a first surface of the sealing plate is provided with a plurality of injection molding grooves, the maximum width of the notch of the injection molding groove is smaller than the maximum width of the groove bottom thereof, and the inner wall of the injection molding groove is provided with a plurality of barb structures away from the first surface; An insulating plate, wherein an exhaust passage is provided at a position of the insulating plate corresponding to the installation hole of the explosion-proof valve, and an injection through hole is provided at a position of the insulating plate corresponding to the injection hole; an injection boss is provided at a position of the insulating plate corresponding to the sealing plate, and the injection boss cooperates with the injection groove; the insulating plate and the sealing plate are connected by injection molding.

2. The battery cover assembly according to claim 1, characterized in that: The maximum width of the bottom of the injection molding groove is D, and the maximum width of the notch of the injection molding groove is d, where Dd≥0.3 mm.

3. The battery cover assembly according to claim 2, characterized in that: The maximum width D of the bottom of the injection molding groove is in the range of 0.8 mm ≤ D ≤ 6.5 mm, and the maximum width d of the notch of the injection molding groove is in the range of 0.5 mm ≤ d ≤ 6 mm.

4. The battery cover assembly according to claim 1 or 2, characterized in that: The depth of the injection molding groove is H, 0.6mm≤H≤3mm.

5. The battery cover assembly according to claim 1 or 2, characterized in that: The remaining thickness of the sealing plate at the bottom of the injection molding groove is t, 0.2 mm≤t≤1.5 mm.

6. The battery cover assembly according to claim 1 or 2, characterized in that: The barb structures are arranged at intervals on the inner wall of the injection groove, the angle between the extension direction of the barb structures and the inner wall of the injection groove is α, the angle between the inner wall of the injection groove and the first surface is β, α<β.

7. The battery cover assembly according to claim 1 or 2, characterized in that: The injection molding grooves are provided in two groups on both sides of the explosion-proof valve installation hole, and at least two are provided in each group at intervals.

8. The battery cover assembly according to claim 1 or 2, characterized in that: It also includes two connecting plates and two poles, the connecting plate includes a pole connecting part and a pole lug connecting part, the pole connecting part and the pole are welded, the pole lug connecting parts of the two connecting plates extend to positions corresponding to the welding through holes, and each pole lug connecting part is welded to the pole lug of the battery cell through the welding through holes.

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; 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, and the electrode group is encapsulated in the shell.

10. A battery pack, characterized in that: The invention comprises a plurality of battery cells as claimed in claim 9.

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