Battery cell and battery pack

Abstract

The utility model relates to the technical field of batteries, and discloses a battery cell and a battery pack, the battery cell mainly comprises a shell, a first cover plate, a second cover plate, a sealing plate and an insulating plate; openings are respectively formed in two opposite sides of the shell, a pole group is arranged in the shell, and a pole lug is arranged at one end of the pole group; the first cover plate and the second cover plate respectively cover the opening of the shell, a through hole and a first pole are arranged on the first cover plate at an interval, a first connecting piece is arranged in the first cover plate, one end of the first connecting piece is connected with the first pole, and the other end of the first connecting piece extends to the through hole and is connected with the tab; the sealing plate and the insulating plate are arranged in the through hole, a groove is formed in the bottom face of the sealing plate, a hot melting column is arranged on the top face of the insulating plate, the insulating plate is connected with the sealing plate through hot melting, and the hot melting column is connected with the groove in an inserted mode. According to the utility model, the first connecting sheets and the tabs are arranged in the through holes, so that the bending times can be reduced, the space utilization rate is improved, the sealing plate is connected with the insulating plate through hot melting, the connecting strength is higher, and the use cost is lower.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to an electric core and a battery pack. Background Art

[0002] With the development of new energy technologies, battery packs are increasingly used in various new energy products. In a battery pack, a pole column is connected to an electrode tab of an electric core through a connecting piece to achieve electrical conduction.

[0003] However, during the connection process of the connecting piece and the electrode tab, bending is required, and the connecting piece, the pole column, and the electrode tab are usually located on the same vertical plane. Therefore, a relatively large thickness space needs to be occupied, resulting in low space utilization rate of the electric core. Summary of the Utility Model

[0004] In view of this, the utility model provides an electric core and a battery pack to solve the problem that the existing connecting piece for connecting the pole column and the electrode tab needs to occupy a relatively large thickness space, resulting in low space utilization rate of the electric core.

[0005] In a first aspect, the utility model provides an electric core, comprising:

[0006] A housing having openings on opposite sides respectively, a pole group is provided inside the housing, and an electrode tab is provided at one end of the pole group;

[0007] A first cover plate and a second cover plate, which are respectively covered on the openings of the housing. A through hole and a first pole column are provided at intervals along the length direction on the first cover plate. A first connecting piece is provided inside the first cover plate. One end of the first connecting piece is connected to the first pole column, and the opposite end extends to the through hole and is connected to the electrode tab; A second pole column is provided on the second cover plate, and the second pole column is connected to the opposite end of the pole group through a second connecting piece;

[0008] A sealing plate and an insulating plate are provided in the through hole. At least one groove is provided on the bottom surface of the sealing plate, and at least one hot melt column is correspondingly provided on the top surface of the insulating plate. The top surface of the insulating plate is connected to the bottom surface of the sealing plate by hot melting, and the hot melt column is inserted into the groove.

[0009] Beneficial effects: A through hole is formed in the first cover plate, and one end of the first connecting piece is connected to the tab at the through hole, reducing the number of bends of the first connecting piece and the tab, thereby reducing the thickness dimension. The other end of the first connecting piece is connected to the first pole column, and the first pole column is arranged offset from the tab, further reducing the thickness dimension and improving the space utilization rate and production efficiency of the battery cell. The sealing plate is used to seal the through hole, and the insulating plate can ensure the insulation performance between the tab and the sealing plate, improving the reliability of the battery cell. The bottom surface of the sealing plate is thermally fused to the top surface of the insulating plate, with a relatively low cost. The sealing plate is provided with a groove into which the thermal fusion post of the insulating plate is inserted, which can ensure the connection strength after the thermal fusion of the sealing plate and the insulating plate.

[0010] In an alternative embodiment, the groove gradually contracts from the inside to the outside, and the thermal fusion post is clamped in the groove.

[0011] Beneficial effects: The groove gradually contracts from the inside to the outside, that is, the bottom area of the groove is larger than the notch area. Correspondingly, the top area of the thermal fusion post is larger than the bottom area, enabling the thermal fusion post to be clamped in the groove, increasing the contact area between the sealing plate and the insulating plate, and further improving the connection stability between the two.

[0012] In an alternative embodiment, the groove is an inverted conical groove, and the thermal fusion post is correspondingly provided as an inverted conical thermal fusion post. The outer diameter of the inverted conical groove is d, satisfying: 0.5 mm ≤ d ≤ 6 mm.

[0013] Beneficial effects: The groove is an inverted conical groove, and the thermal fusion post is correspondingly provided as an inverted conical thermal fusion post, which can ensure that the thermal fusion post is tightly inserted into the groove, and has a simple structure and is convenient for processing and manufacturing.

[0014] In an alternative embodiment, the outer diameter d of the inverted conical groove and the inner diameter D of the inverted conical groove satisfy: d - D ≥ 0.3 mm.

[0015] Beneficial effects: By setting the dimensions of the outer diameter and the inner diameter of the inverted conical groove, it can ensure that the inverted conical thermal fusion post is clamped in the inverted conical groove, thereby ensuring the connection strength after the thermal fusion of the sealing plate and the insulating plate.

[0016] In an alternative embodiment, the thickness t of the thermal fusion rib plane of the sealing plate satisfies: 0.2 mm ≤ t ≤ 1.5 mm.

[0017] Beneficial effects: The thickness of the thermal fusion rib plane of the sealing plate, that is, the distance between the upper surface of the sealing plate and the bottom of the groove. By setting the thickness of the thermal fusion rib plane of the sealing plate, the structural strength of the sealing plate can be ensured.

[0018] In an alternative embodiment, the height h of the thermal fusion post and the depth H of the groove satisfy: h - H ≥ 0.25 mm.

[0019] Beneficial effects: Since the height of the hot melt column is greater than the depth of the groove, after the bottom surface of the sealing plate and the bottom surface of the insulating plate are hot melt connected into a whole, the hot melt column is compressed in the groove to fully ensure the connection strength between the sealing plate and the insulating plate.

[0020] In an alternative embodiment, a plurality of the hot melt columns are arranged at intervals along the length direction of the top surface of the insulating plate, and a plurality of the grooves are correspondingly arranged on the bottom surface of the sealing plate.

[0021] Beneficial effects: By arranging a plurality of hot melt columns in cooperation with a plurality of grooves, it is beneficial for the sealing plate and the insulating plate to be stressed evenly, so as to improve the connection stability between the sealing plate and the insulating plate.

[0022] In an alternative embodiment, liquid injection holes and explosion-proof valves are further arranged at intervals on the second cover plate.

[0023] Beneficial effects: The liquid injection holes and the explosion-proof valves are arranged on the second cover plate to reserve a setting space for the through holes on the first cover plate. The liquid injection holes are used for injecting electrolyte. The explosion-proof valve opens when the internal air pressure of the battery cell is greater than the preset air pressure, so that the chamber inside the battery cell communicates with the outside through the explosion-proof valve and discharges the high-pressure gas, so as to avoid explosion due to too high internal air pressure of the battery cell.

[0024] In an alternative embodiment, the tab includes a bent portion formed by converging the end of the electrode group, a notch is left on the portion of the first connecting piece extending to the through hole, the bent portion passes through the notch and is bent 90° relative to the electrode group and then welded to the upper surface of the first connecting piece.

[0025] Beneficial effects: After the tab is converged to form a bent portion, it only needs to be bent 90° to realize welding with the first connecting piece, and the connecting piece does not need to be bent. Therefore, the total number of bends is less, the thickness space occupied by the bending of the tab and the first connecting piece is reduced, thereby improving the space utilization rate of the battery cell, and the bending process of the first connecting piece can also be omitted, improving the production efficiency of the battery cell.

[0026] In a second aspect, the present invention further provides a battery pack, including: a plurality of the above-mentioned battery cells.

[0027] Beneficial effects: Since the battery pack includes battery cells and has the same effects as the battery cells, that is, through holes are provided on the first cover plate, one end of the first connecting piece is connected to the tab at the through hole, reducing the number of bends of the connecting piece and the tab, thereby reducing the thickness dimension. The other end of the first connecting piece is connected to the first pole, and the first pole is arranged offset from the tab, further reducing the thickness dimension and improving the space utilization rate and production efficiency of the battery cell. The sealing plate is used to seal the through hole, and the insulating plate can ensure the insulation performance between the tab and the sealing plate, improving the reliability of the battery cell. The bottom surface of the sealing plate and the top surface of the insulating plate are connected by hot melting, with relatively low cost. The sealing plate is provided with grooves inserted into the hot melting posts of the insulating plate, which can ensure the connection strength after hot melting of the sealing plate and the insulating plate. Description of the Drawings

[0028] In order 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 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 invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0029] Figure 1 Partial structural schematic diagram of one end of a battery cell according to an embodiment of the present invention;

[0030] Figure 2 Partial structural schematic diagram of the opposite end of a battery cell according to an embodiment of the present invention;

[0031] Figure 3 Partial cross-sectional view of one end of a battery cell according to an embodiment of the present invention;

[0032] Figure 4 Structural schematic diagram of the first cover plate of a battery cell according to an embodiment of the present invention;

[0033] Figure 5 Another perspective structural schematic diagram of the first cover plate of a battery cell according to an embodiment of the present invention;

[0034] Figure 6 Structural schematic diagram of the sealing plate and the insulating plate of a battery cell according to an embodiment of the present invention;

[0035] Figure 7 Structural schematic diagram of the insulating plate of a battery cell according to an embodiment of the present invention;

[0036] Figure 8 Cross-sectional view of the sealing plate and the insulating plate of a battery cell according to an embodiment of the present invention;

[0037] Figure 9 For Figure 8Enlarged view of part A;

[0038] Figure 10 Partial cross-sectional view of an insulating plate of a battery cell according to an embodiment of the present utility model;

[0039] Figure 11 Partial structural schematic diagram of an ear of a battery cell before bending according to an embodiment of the present utility model;

[0040] Figure 12 Partial structural schematic diagram of an ear of a battery cell after bending according to an embodiment of the present utility model.

[0041] Explanation of reference numerals in the drawings:

[0042] 1. Housing; 2. Electrode group; 3. Ear; 301. Bending part; 4. First cover plate; 401. Through hole; 402. First pole; 403. First connecting piece; 5. Second cover plate; 501. Second pole; 6. Sealing plate; 601. Groove; 7. Insulating plate; 701. Hot melt column; 8. Liquid injection hole; 9. Explosion-proof valve. Specific embodiments

[0043] 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.

[0044] The following combines with Figures 1 to 12 , to describe the embodiments of the present utility model.

[0045] According to an embodiment of the present utility model, on the one hand, as Figures 1 to 3As shown, a battery cell is provided, mainly including: a housing 1, a first cover plate 4, a second cover plate 5, a sealing plate 6, and an insulating plate 7. Openings are respectively provided on two opposite sides of the housing 1. A pole group 2 is provided inside the housing 1, and a pole tab 3 is provided at one end of the pole group 2. The first cover plate 4 and the second cover plate 5 are respectively covered on the openings on two opposite sides of the housing 1. Through holes 401 and a first pole column 402 are spaced along the length direction on the first cover plate 4. A first connecting piece 403 is provided inside the first cover plate 4. One end of the first connecting piece 403 is connected to the first pole column 402, and the opposite end extends to the through hole 401 and is connected to the pole tab 3. A second pole column 501 is provided on the second cover plate 5, and the second pole column 501 is connected to the opposite end of the pole group 2 through a second connecting piece. The sealing plate 6 and the insulating plate 7 are arranged in the through hole 401. At least one groove 601 is provided on the bottom surface of the sealing plate 6, and at least one hot melt column 701 is correspondingly provided on the top surface of the insulating plate 7. The top surface of the insulating plate 7 is connected to the bottom surface of the sealing plate 6 by hot melting, and the hot melt column 701 is inserted into the groove 601.

[0046] For the battery cell provided by the embodiment of the present utility model, through holes 401 are opened on the first cover plate 4, and one end of the first connecting piece 403 is connected to the pole tab 3 at the through hole 401, reducing the number of bends of the first connecting piece 403 and the pole tab 3, thereby reducing the thickness dimension. The other end of the first connecting piece 403 is connected to the first pole column 402, and the first pole column 402 is arranged in a staggered manner with the pole tab 3, further reducing the thickness dimension, improving the space utilization rate and production efficiency of the battery cell. The sealing plate 6 is used to seal the through hole 401, and the insulating plate 7 can ensure the insulation performance between the pole tab 3 and the sealing plate 6, improving the reliability of the battery cell. The bottom surface of the sealing plate 6 and the top surface of the insulating plate 7 are connected by hot melting, with a relatively low cost. The sealing plate 6 is provided with grooves 601 inserted with the hot melt columns 701 of the insulating plate 7, which can ensure the connection strength after the sealing plate 6 and the insulating plate 7 are hot melted.

[0047] Specifically, the through holes 401 are used to reserve installation space for the connection of the first connecting piece 403 and the pole tab 3. The sealing plate 6 is used to seal the through hole 401. The insulating plate 7 can play an insulating effect on the sealing plate 6. Arranging the sealing plate 6 and the insulating plate 7 in the through hole 401 and connecting the top surface of the insulating plate 7 to the bottom surface of the sealing plate 6 can reduce the occupied space of the sealing plate 6 and the insulating plate 7. As Figure 6 shown, the top surface of the insulating plate 7 is completely attached to the bottom surface of the sealing plate 6.

[0048] The top and bottom directions of the embodiment of the present utility model are as Figure 1 shown. The length direction of the first cover plate 4 is as Figure 4 shown by the arrow L in

[0049] It should be noted that the embodiments of the present utility model do not limit the materials of the sealing plate 6 and the insulating plate 7, and any existing materials can be selected according to needs. For example, the sealing plate 6 can be made of aluminum plate, and the insulating plate 7 can be made of polypropylene plate (PP plate).

[0050] In addition, the connection manner between the first cover plate 4, the second cover plate 5 and the housing 1 is not limited either. A detachable connection structure can be adopted, such as being snap-connected through a buckle and a slot for quick installation, or a fixed connection structure can be adopted, such as welding the first cover plate 4, the second cover plate 5 and the housing 1 into an integral whole for firm connection.

[0051] Specifically, as Figure 1 and Figure 2 shown, a surrounding plate is provided around the housing 1, and openings are respectively formed at the upper and lower ends. The first cover plate 4 covers the upper opening, and the second cover plate 5 covers the lower opening. The surrounding plate, the first cover plate 4 and the second cover plate 5 enclose a closed cavity. As Figure 3 , Figure 11 and Figure 12 shown, the electrode group 2 is arranged in the cavity. An electrode tab 3 is arranged on the side of the electrode group 2 close to the first cover plate 4. The electrode post generally includes a positive electrode post and a negative electrode post. The first electrode post 402 in the embodiment of the present utility model can be a positive electrode post, and correspondingly, the second electrode post 501 is a negative electrode post. The first electrode post 402 can also be a negative electrode post, and correspondingly, the second electrode post 501 is a positive electrode post. The first connecting piece 403 is correspondingly connected to the first electrode post 402, and the second connecting piece is correspondingly connected to the second electrode post 501.

[0052] During assembly, one end of the electrode group 2 is first welded to the second connecting piece, and then the second connecting piece is welded to the second cover plate 5, so that the electrode group 2, the second connecting piece and the second cover plate 5 form an integral whole and are installed in the cavity of the housing 1. The electrode tab 3 of the electrode group 2 is not bent before being connected to the first connecting piece 403, that is, the extending direction of the electrode tab 3 is the same as the length direction of the electrode group 2. After the electrode tab 3 is installed in the housing 1, it passes through the first cover plate 4, and the electrode tab 3 is bent at the through hole 801, and the electrode tab 3 is welded to the first connecting piece 403. Finally, the sealing plate 6 is welded at the through hole 401 to achieve sealing.

[0053] In one embodiment, the groove 601 gradually contracts from inside to outside, and the hot melt column 701 is clamped in the groove 601. The groove 601 gradually contracts from inside to outside, that is, the bottom area of the groove 601 is larger than the notch area, and correspondingly, the top area of the hot melt column 701 is larger than the bottom area, so that the hot melt column 701 can be clamped in the groove 601, increasing the contact area between the sealing plate 6 and the insulating plate 7 and further improving the connection stability between the two.

[0054] Furthermore, in one embodiment, as Figures 7 to 9 shown, the groove 601 is an inverted conical groove. AsFigure 10 As shown, the hot melt column 701 is correspondingly set as an inverted conical hot melt column. The outer diameter of the inverted conical groove is d, satisfying: 0.5 mm ≤ d ≤ 6 mm. It can ensure that the hot melt column 701 is tightly inserted into the groove 601, and the structure is simple, facilitating processing and manufacturing.

[0055] Furthermore, in one embodiment, as Figure 9 shown, the outer diameter d of the inverted conical groove and the inner diameter D of the inverted conical groove satisfy: d - D ≥ 0.3 mm. By setting the dimensions of the outer diameter and the inner diameter of the inverted conical groove, it can ensure that the inverted conical hot melt column is clamped in the inverted conical groove, thereby guaranteeing the connection strength after the sealing plate 6 and the insulating plate 7 are hot melted.

[0056] Furthermore, in one embodiment, as Figure 9 shown, the thickness t of the hot melt rib plane of the sealing plate 6 satisfies: 0.2 mm ≤ t ≤ 1.5 mm. The thickness of the hot melt rib plane of the sealing plate 6 is also the distance between the upper surface of the sealing plate 6 and the bottom of the groove 601. By setting the thickness of the hot melt rib plane of the sealing plate 6, the structural strength of the sealing plate 6 can be ensured.

[0057] In one embodiment, as Figure 9 and Figure 10 shown, the height h of the hot melt column 701 and the depth H of the groove 601 satisfy: h - H ≥ 0.25 mm. Since the height of the hot melt column 701 is greater than the depth of the groove 601, after the bottom surface of the sealing plate 6 and the bottom surface of the insulating plate 7 are hot melted and connected as a whole, the hot melt column 701 is compressed in the groove 601 to fully guarantee the connection strength between the sealing plate 6 and the insulating plate 7.

[0058] In one embodiment, as Figure 7 and Figure 8 shown, a plurality of hot melt columns 701 are arranged at intervals along the length direction of the top surface of the insulating plate 7, and a plurality of grooves 601 are correspondingly arranged on the bottom surface of the sealing plate 6. By arranging a plurality of hot melt columns 701 in cooperation with a plurality of grooves 601, it is beneficial for the sealing plate 6 and the insulating plate 7 to be uniformly stressed, so as to improve the connection stability between the sealing plate 6 and the insulating plate 7.

[0059] In one embodiment, as Figure 2 shown, the second cover plate 5 is also provided with a liquid injection hole 8 and an explosion-proof valve 9 at intervals. Specifically, the second cover plate 5 is sequentially provided with a liquid injection hole 8, an explosion-proof valve 9 and a second pole column 501 along the length direction. The liquid injection hole 8 and the explosion-proof valve 9 are arranged on the second cover plate 5 to leave a setting space for the through hole 401 of the first cover plate 4. The liquid injection hole 8 is used for injecting electrolyte. The explosion-proof valve 9 opens when the internal pressure of the battery cell is greater than the preset pressure, so that the chamber inside the battery cell is communicated with the outside through the explosion-proof valve 9, and the high-pressure gas is discharged to avoid explosion due to excessive internal pressure of the battery cell.

[0060] In one embodiment, as Figure 11 and Figure 12 shown, the tab 3 includes a bent portion 301 formed by gathering the end of the electrode group 2. A notch is left on the portion of the first connecting piece 403 extending to the through hole 401. The bent portion 301 passes through the notch and is bent 90° relative to the electrode group 2 and then welded to the upper surface of the first connecting piece 403.

[0061] After the tab 3 is gathered to form the bent portion 301, it only needs to be bent 90° to achieve welding with the first connecting piece 403, and the connecting piece does not need to be bent. Therefore, the total number of bends is small, reducing the thickness space occupied by the bending of the tab 3 and the first connecting piece 403, thereby improving the space utilization rate of the battery cell, and it can also omit the bending process of the first connecting piece 403, improving the production efficiency of the battery cell.

[0062] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, mainly including: a plurality of battery cells.

[0063] Since the battery pack includes battery cells and has the same effects as the battery cells, that is, a through hole 401 is formed in the first cover plate 4, one end of the first connecting piece 403 is connected to the tab 3 at the through hole 401, reducing the number of bends between the first connecting piece 403 and the tab 3, thereby reducing the thickness dimension. The other end of the first connecting piece 403 is connected to the first pole column 402, and the first pole column 402 is arranged offset from the tab 3, further reducing the thickness dimension, improving the space utilization rate and production efficiency of the battery cell. The sealing plate 6 is used to seal the through hole 401, and the insulating plate 7 can ensure the insulation performance between the tab 3 and the sealing plate 6, improving the reliability of the battery cell. The bottom surface of the sealing plate 6 and the top surface of the insulating plate 7 are connected by hot melting, with a lower cost. The sealing plate 6 is provided with a groove 601 inserted with the hot melting column 701 of the insulating plate 7, which can ensure the connection strength after the hot melting of the sealing plate 6 and the insulating plate 7.

[0064] Specifically, the plurality of battery cells can be connected in series, in parallel, or in a form of series-parallel combination. In this regard, the embodiments of the present invention do not have many restrictions.

[0065] 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 shell having openings on two opposite sides, a pole group is arranged in the shell, and a pole ear is arranged at one end of the pole group; A first cover plate and a second cover plate are respectively covered on the opening of the housing, the first cover plate is provided with through holes and first poles at intervals along the length direction, a first connecting piece is provided in the first cover plate, one end of the first connecting piece is connected to the first pole, and the other end of the first connecting piece extends to the through hole and is connected to the pole ear; a second pole is provided on the second cover plate, and the second pole is connected to the other end of the pole group through the second connecting piece; A sealing plate and an insulating plate are arranged in the through hole. The bottom surface of the sealing plate is provided with at least one groove, and the top surface of the insulating plate is correspondingly provided with at least one hot melt column. The top surface of the insulating plate is connected to the bottom surface of the sealing plate by hot melting, and the hot melt column is plugged into the groove.

2. The battery cell according to claim 1, characterized in that: The groove gradually shrinks from the inside to the outside, and the hot melt column is clamped in the groove.

3. The battery cell according to claim 2, characterized in that: The groove is an inverted conical groove, and the hot melt column is correspondingly set to an inverted conical hot melt column. The outer diameter of the inverted conical groove is d, which satisfies: 0.5mm≤d≤6mm.

4. The battery cell according to claim 3, characterized in that: The outer diameter d of the inverted tapered groove and the inner diameter D of the inverted tapered groove satisfy: dD≥0.3mm.

5. The battery cell according to claim 4, characterized in that: The thickness t of the hot melt rib surface of the sealing plate satisfies: 0.2mm≤t≤1.5mm.

6. The battery cell according to claim 2, characterized in that: The height h of the hot melt column and the depth H of the groove satisfy: hH≥0.25mm.

7. The battery cell according to any one of claims 1 to 6, characterized in that: The top surface of the insulating plate is provided with a plurality of the heat-melting columns at intervals along the length direction, and the bottom surface of the sealing plate is correspondingly provided with a plurality of the grooves.

8. The battery cell according to any one of claims 1 to 6, characterized in that: The second cover plate is also provided with injection holes and explosion-proof valves at intervals.

9. The battery cell according to any one of claims 1 to 6, characterized in that: The pole ear includes a bent portion formed by gathering the end of the pole group, and a gap is left at the portion of the first connecting piece extending to the through hole. The bent portion passes through the gap and is bent 90° relative to the pole group and then welded to the upper surface of the first connecting piece.

10. A battery pack, characterized in that: include: A plurality of battery cells according to any one of claims 1 to 9.

Images