Battery cell and battery pack

Abstract

The utility model relates to the technical field of battery cells, and discloses a battery cell and a battery pack. Wherein the battery cell comprises a shell, two ends of the shell are provided with openings and cover plates for sealing the openings, the cover plates are provided with pole columns, and one of the cover plates is provided with a through hole; the pole group is arranged in the shell, the two ends of the pole group are provided with pole lugs, the pole lugs and the corresponding pole columns are arranged in a staggered manner, one pole lug comprises a body connected with the pole group and a bending part which is bent towards one side from the end part of the body, and the bending part is arranged corresponding to the through hole; the pair of connecting sheets are arranged in the shell and are respectively arranged at the two ends of the pole group, the connecting sheets are used for connecting the pole columns and the corresponding tabs, and one connecting sheet is fixed in a space defined by the body and the bending part and is attached to the lower surface of the bending part. The tabs and the poles are arranged in a staggered manner, so that the installation thickness of the poles and the tabs in a connection state is reduced, and the utilization rate of the internal space of the shell is improved; and secondly, the tabs are connected with the connecting sheets through the bending parts, so that the operation difficulty in the connecting process can be reduced.

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] The connecting piece in the battery cell is a metal piece used to connect the pole column of the battery cell and the ear of the pole group, which ensures the smooth flow of current between the pole column and the ear, and realizes the storage and release of electric energy of the battery cell.

[0003] However, the method of connecting the connecting piece to the ear in the related art is not only relatively complex to operate, but also occupies more internal space of the battery cell. Summary of the Utility Model

[0004] In view of this, the utility model provides a battery cell and a battery pack to solve the problems that the connection method between the connecting piece and the ear in the related art is complex and occupies more internal space of the battery cell.

[0005] In a first aspect, the utility model provides a battery cell, comprising:

[0006] A housing with openings at both ends and a cover plate for sealing the openings, the cover plate is provided with a pole column, and a through hole is provided on one of the cover plates, and a liquid injection hole and an explosion-proof valve are provided on the other cover plate;

[0007] A pole group disposed in the housing and having ears at both ends, the ears are arranged in a staggered manner with the corresponding pole columns, and one of the ears includes a body connected to the pole group and a bent portion bent from the end of the body toward one side, and the bent portion is disposed corresponding to the through hole;

[0008] A pair of connecting pieces disposed in the housing and respectively disposed at both ends of the pole group, the connecting pieces are used to connect the pole column and its corresponding ear, and one of the connecting pieces is fixed in the space defined by the body and the bent portion and is attached to the lower surface of the bent portion.

[0009] Beneficial effects: By providing an opening on the housing that communicates with its interior, the utility model facilitates the assembly of components such as the electrode group into the housing by the operator, improving the convenience of assembly. Further, a cover plate is used to seal the opening, ensuring the tightness of the battery cell, reducing the possibility of external moisture, dust, and other impurities entering the interior of the battery cell, guaranteeing the cleanliness and stability of the internal environment of the battery cell, and thus being conducive to extending the service life of the battery cell. Secondly, the pole column and the pole ear of the utility model are arranged in a staggered manner, making use of the space in other directions inside the housing. Compared with the existing connection piece and pole ear both arranged along the axial direction of the pole column, the internal space of the housing occupied by the connection piece and the pole ear in the connection state in the height direction (axial direction of the pole column) of the housing is reduced, improving the utilization rate of the internal space of the housing. Furthermore, the pole ear is connected to the connection piece through a bending portion, which can reduce the operation difficulty of connecting the pole ear and the connection piece and also reduce the occupation of the internal space of the housing when they are in the connected state.

[0010] In addition, the utility model arranges the liquid injection hole and the explosion-proof valve on the cover plate. On the one hand, it can make the structure of the cover plate itself more compact and optimize the structural layout on the cover plate. On the other hand, it is convenient to add electrolyte into the battery cell, and at the same time, it can prevent the pressure inside the battery cell from being too high, improving the safety of using the battery cell.

[0011] In an optional embodiment, the connection position between the body and the electrode group is biased towards one side of the electrode group, and the offset W1 ≤ 1 / 2W, where W is the thickness of the electrode group, and W ranges from 6 mm to 30 mm.

[0012] Beneficial effects: By setting the offset W1 within a reasonable range, the utility model can ensure the flatness of the end face of the folded bending portion, omit the pole ear die-cutting process, reduce the use cost, and improve the production efficiency.

[0013] In an optional embodiment, one end of the electrode group connected to the body forms a converging inclined surface, and the height h of the converging inclined surface ranges from 0.2 mm to 3.5 mm.

[0014] Beneficial effects: Since the height of the converging inclined surface is determined by the thickness of the electrode group, setting the height of the converging inclined surface within a reasonable range can compact the folded pole ear and endow the electrode group with a certain bearing capacity.

[0015] In an optional embodiment, the thickness t of the bending portion ranges from 0.1 mm to 2.5 mm.

[0016] Beneficial effects: By setting the thickness t of the bending portion within a reasonable range, the utility model can further save the space in the height direction of the electrode group and improve the space utilization rate of the battery cell.

[0017] In an optional implementation, a height H of the bent portion relative to the pole group is 1.5 mm to 5 mm.

[0018] Beneficial effect: By setting the height of the bending portion relative to the pole group, the space of the battery cell in the pole group height direction can be saved to the maximum extent while ensuring the strength and reliability of the bending portion, thereby improving the space utilization of the battery cell.

[0019] In an optional embodiment, the connecting piece includes a pole connecting portion connected to the pole and a tab connecting portion connected to the tab.

[0020] Beneficial effect: Since the pole lug and pole post in the utility model are staggered, the connecting piece is divided into a pole post connecting part and a pole lug connecting part, so that the connecting piece can be adapted to the position of the pole lug and the pole post, so that the pole lug and the pole post can be connected, realizing smooth flow of current between the pole lug and the pole post.

[0021] In an optional embodiment, a first gap is left between the tab connection portion and the inner wall of the shell extending along its length direction, and the bending portion passes through the body through the first gap and the through hole and is arranged on the upper surface of the tab connection portion.

[0022] Beneficial effect: Since the lower surface of the bent portion needs to fit with the upper surface of the tab connection portion, if the bent portion is to come to the upper surface of the tab connection portion, it is usually necessary to set a passage opening suitable for the body to pass through on the tab connection portion. However, this will make the structure of the tab connection portion relatively complicated and increase the initial production cost. Therefore, in order to solve the above problem, the utility model allows the body to pass through the first gap between the tab connection portion and the inner wall of the shell extending along the length direction thereof and the through hole on the cover plate, so that there is no need to make complex adjustments to the structure of the connecting piece, simplifying the structure of the connecting piece itself.

[0023] In an optional embodiment, a second gap is left between a side of the body facing the bending portion and a side wall of the tab connecting portion, and a length a of the second gap is ≥ 0.2 mm.

[0024] Beneficial effect: The utility model limits the size of the second gap length, which can avoid interference between the pole ear and the connecting sheet on the one hand, and prevent the connecting sheet from tearing the pole ear on the other hand.

[0025] In an optional implementation, a sealing plate is provided on the cover plate, and the sealing plate is welded to the through hole and seals the through hole.

[0026] Beneficial effects: In the present utility model, the sealing plate and the through hole are welded and connected by welding. On the one hand, the connection strength between the two can be improved, reducing the possibility of the sealing plate falling off during the use of the battery cell. On the other hand, the appearance of gaps between the sealing plate and the hole wall of the through hole can be avoided, improving the self-sealing performance of the housing and reducing the possibility of external impurities entering the interior of the battery cell.

[0027] Second, the present utility model also provides a battery pack including: a plurality of the above-mentioned battery cells.

[0028] Beneficial effects: By adopting the above-mentioned battery cells, the battery pack of the present utility model can improve its space utilization rate, so that without changing its own volume, its energy density can be increased, its service time can be extended or the charging frequency can be reduced. In addition, the battery pack of the present utility model has all the advantages of the above-mentioned battery cells, which will not be elaborated here. Description of the Drawings

[0029] 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, without creative efforts, other drawings can also be obtained based on these drawings.

[0030] Figure 1 Partial structural schematic diagram of a battery cell according to an embodiment of the present utility model;

[0031] Figure 2 Partial structural schematic diagram of another battery cell according to an embodiment of the present utility model;

[0032] Figure 3 Structural schematic diagram of a battery cell without assembling the housing and the cover plate according to an embodiment of the present utility model;

[0033] Figure 4 Structural schematic diagram of a pole group according to an embodiment of the present utility model;

[0034] Figure 5 Cross-sectional schematic diagram of a cover plate according to an embodiment of the present utility model;

[0035] Figure 6 Bottom view schematic diagram of a cover plate according to an embodiment of the present utility model;

[0036] Figure 7 Structural schematic diagram of another cover plate according to an embodiment of the present utility model;

[0037] Figure 8 For Figure 7 Cross-sectional schematic diagram of the shown cover plate;

[0038] Figure 9 is Figure 7 The bottom view schematic diagram of the shown cover plate.

[0039] Explanation of the reference numerals in the drawings:

[0040] 1. Housing; 101. Cover plate; 1011. Liquid injection hole; 1012. Explosion-proof valve; 1013. Sealing plate; 102. Terminal post; 103. Through hole; 2. Electrode group; 201. Converging inclined surface; 3. Tab; 301. Body; 302. Bent portion; 303. Transition fillet; 4. Connecting piece; 401. Terminal post connecting portion; 402. Tab connecting portion; 5. First gap; 6. Second gap. Specific embodiments

[0041] In order 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.

[0042] Aiming at the problems in the related art that the connection method between the connecting piece and the tab is complex and occupies a relatively large internal space of the battery cell, the present utility model provides a battery cell and a battery pack.

[0043] Next, in conjunction with Figures 1 to 9 , the embodiments of the present utility model will be described.

[0044] According to the embodiments of the present utility model, on the one hand, as Figures 1 to 9 shown, a battery cell is provided, including: a housing 1, an electrode group 2 and a pair of connecting pieces 4.

[0045] Specifically, openings are provided at both ends of the housing 1 and a cover plate 101 for sealing the openings, the cover plate 101 is provided with a terminal post 102, a through hole 103 is provided on one of the cover plates 101, and a liquid injection hole 1011 and an explosion-proof valve 1012 are provided on the other cover plate 101; the electrode group 2 is arranged in the housing 1 and tabs 3 are provided at both ends, the tabs 3 are arranged in a staggered manner with the corresponding terminal posts 102, one of the tabs 3 includes a body 301 connected to the electrode group 2 and a bent portion 302 bent from the end of the body 301 toward one side, and the bent portion 302 is arranged corresponding to the through hole 103; a pair of connecting pieces 4 are arranged in the housing 1 and are respectively arranged at both ends of the electrode group 2, the connecting pieces 4 are used to connect the terminal posts 102 and their corresponding tabs 3, and one of the connecting pieces 4 is fixed in the space defined by the body 301 and the bent portion 302 and is attached to the lower surface of the bent portion 302.

[0046] In this embodiment, an opening communicating with the interior is provided on the housing 1, facilitating the operator to assemble structures such as the electrode group 2 into the housing 1 and improving the assembly convenience. Further, the cover plate 101 is used to seal the opening, ensuring the tightness of the battery cell, reducing the possibility of external moisture, dust and other impurities entering the interior of the battery cell, guaranteeing the cleanliness and stability of the interior environment of the battery cell, and thus being conducive to extending the service life of the battery cell. Secondly, the pole post 102 and the pole tab 3 of this embodiment are arranged in a staggered manner, making use of the space in other directions inside the housing 1. Compared with the existing connection piece 4 and the pole tab 3 both arranged along the axial direction of the pole post 102, the internal space of the housing 1 occupied by the connection piece 4 and the pole tab 3 in the height direction (axial direction of the pole post) of the housing 1 in the connected state is reduced, improving the utilization rate of the internal space of the housing 1, and thus enabling the battery cell to store more energy under the same volume. Moreover, the pole tab 3 is connected to the connection piece 4 through the bending part 302, which can reduce the operation difficulty of connecting the pole tab 3 and the connection piece 4 and also reduce the occupation of the internal space of the housing 1 by the two in the connected state.

[0047] In addition, in this embodiment, the liquid injection hole 1011 and the explosion-proof valve 1012 are arranged on the cover plate 101. On the one hand, it can make the self-structure of the cover plate 101 more compact and optimize the structural layout on the cover plate 101; on the other hand, it is convenient to add electrolyte into the battery cell, and at the same time, it can avoid the pressure inside the battery cell from being too high, improving the use safety of the battery cell.

[0048] It should be noted that the height direction of the above-mentioned housing 1 is Figure 1 and Figure 2 consistent with the direction shown in

[0049] To improve the connection strength between the body 301 and the bending part 302, in a specific embodiment, as Figure 3 and Figure 4 shown, a transition fillet 303 is formed at the connection between the body 301 and the bending part 302. Such a setting can avoid the occurrence of stress concentration. In addition, the radius of the transition fillet 303 in this embodiment is 0.1 mm to 0.3 mm.

[0050] According to an embodiment of the present invention, as Figure 4 shown, the connection between the body 301 and the electrode group 2 is biased towards one side of the electrode group 2, and the offset W1 ≤ 1 / 2W, where W is the thickness of the electrode group 2 and W is 6 mm to 30 mm. By setting the offset W1 within a reasonable range in this embodiment, the flatness of the end face of the bent part 302 after folding can be ensured, the die-cutting process of the pole tab 3 can be omitted, the use cost can be reduced and the production efficiency can be improved. It should be noted that the end face of the bending part 302 is as Figure 4 s shown in

[0051] According to an embodiment of the present utility model, as Figure 4 shown, one end of the electrode group 2 connected to the body 301 forms a converging inclined surface 201, and the height h of the converging inclined surface 201 is 0.2 mm to 3.5 mm. Since the height of the converging inclined surface 201 is determined by the thickness of the electrode group 2, setting the height of the converging inclined surface 201 within a reasonable range can compact the folded tab 3, enabling the electrode group 2 to have a certain load-bearing capacity.

[0052] According to an embodiment of the present utility model, as Figure 4 shown, the thickness t of the bending portion 302 is 0.1 mm to 2.5 mm. In this embodiment, setting the thickness t of the bending portion 302 within a reasonable range can further save the space in the height direction of the electrode group 2 and improve the space utilization rate of the battery cell.

[0053] According to an embodiment of the present utility model, as Figure 4 shown, the height H of the bending portion 302 relative to the electrode group 2 is 1.5 mm to 5 mm. By setting the height of the bending portion 302 relative to the electrode group 2 in this embodiment, it is possible to save the space of the battery cell in the height direction of the electrode group 2 to the greatest extent while ensuring the strength and reliability of the bending portion 302, and improve the space utilization rate of the battery cell.

[0054] According to an embodiment of the present utility model, as Figure 6 shown, the connecting piece 4 includes a pole connection portion 401 connected to the pole 102 and an ear connection portion 402 connected to the tab 3. Since the tab 3 and the pole 102 in this embodiment are arranged in a staggered manner, the connecting piece 4 is divided into the pole connection portion 401 and the ear connection portion 402, which can adapt the position of the connecting piece 4 to the tab 3 and the pole 102, so that the tab 3 and the pole 102 can be connected, realizing the smooth flow of current between the tab 3 and the pole 102.

[0055] According to an embodiment of the present utility model, as Figure 1As shown, a first gap 5 is left between the tab connection part 402 and the inner wall of the housing 1 extending along its length direction. The bent part 302 is disposed on the upper surface of the tab connection part 402 through the body 301 passing through the first gap 5 and the through hole 103. Since the lower surface of the bent part 302 needs to be fitted to the upper surface of the tab connection part 402, generally, a channel opening suitable for the body 301 to pass through needs to be provided on the tab connection part 402. However, this will make the structure of the tab connection part 402 relatively complex and increase the production cost in the early stage. Therefore, to solve the above problems, in this embodiment, the body 301 passes through the first gap 5 between the tab connection part 402 and the inner wall of the housing 1 extending along its length direction and the through hole 103 on the cover plate 101, and the structure of the connecting piece 4 can be simplified without making complex adjustments to the structure of the connecting piece 4.

[0056] It should be noted that the length direction of the above-mentioned housing 1 is consistent with Figure 1 and Figure 2 the direction shown in

[0057] According to an embodiment of the present invention, as Figure 3 shown, a second gap 6 is left between the side wall of the tab connection part 402 and the side of the body 301 facing the bent part 302, and the length a of the second gap 6 ≥ 0.2 mm. By limiting the length dimension of the second gap 6 in this embodiment, on the one hand, interference between the tab 3 and the connecting piece 4 can be avoided, and on the other hand, the connecting piece 4 can be prevented from tearing the tab 3.

[0058] According to an embodiment of the present invention, as Figure 5 shown, a sealing plate 1013 is provided on the cover plate 101, and the sealing plate 1013 is welded to and seals the through hole 103. By welding the sealing plate 1013 to the through hole 103 in this embodiment, on the one hand, the connection strength between the two can be improved, reducing the possibility of the sealing plate 1013 falling off during the use of the battery cell; on the other hand, the appearance of a gap between the sealing plate 1013 and the hole wall of the through hole 103 can be avoided, improving the self-sealing performance of the housing 1 and reducing the possibility of external impurities entering the interior of the battery cell.

[0059] According to an embodiment of the present invention, on the other hand, a battery pack is further provided, including: a plurality of the above-mentioned battery cells.

[0060] It can be understood that by adopting the above-mentioned battery cells, the battery pack of this embodiment can improve its space utilization rate, so that without changing its own volume, its energy density can be improved, its service time can be extended or the charging frequency can be reduced. In addition, the battery pack of the present invention has all the advantages of the above-mentioned battery cells and will not be elaborated here.

[0061] It should be noted that the battery cell in this embodiment can be a blade battery. Specifically, the battery pack in this embodiment can be formed by connecting multiple blade batteries in series, or by connecting multiple blade batteries in parallel, or by a combination of series and parallel connections of multiple blade batteries. Specific adjustments can be made according to the actual application scenarios and requirements, and the present utility model does not make specific limitations thereto.

[0062] In addition, to achieve the basic functions of the battery pack, the battery pack in this embodiment may further include other necessary modules or components, such as a battery management system, a heat dissipation system, etc. It should be noted that for the other necessary modules or components included in the battery pack, any suitable existing structure can be selected. To clearly and briefly illustrate the technical solution provided in this embodiment, the above parts will not be elaborated herein, and the accompanying drawings of the specification have also been correspondingly simplified. However, it should be understood that the scope of the present utility model is not limited thereby.

[0063] 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 cell, characterized in that: include: The shell has openings and covers for sealing the openings at both ends, the covers are provided with poles, one of the covers is provided with a through hole, and the other cover is provided with a liquid injection hole and an explosion-proof valve; A pole group is arranged in the shell and has pole ears at both ends, the pole ears are staggered with the corresponding pole column, one of the pole ears includes a body connected to the pole group and a bending portion bent toward one side from the end of the body, and the bending portion is arranged corresponding to the through hole; A pair of connecting plates are arranged in the shell and respectively arranged at the two ends of the pole group, and the connecting plates are used to connect the pole column and its corresponding pole ear. One of the connecting plates is fixed in the space defined by the main body and the bending portion and is in contact with the lower surface of the bending portion.

2. The battery cell according to claim 1, characterized in that: The connection between the main body and the pole group is biased toward one side of the pole group, and the offset W1≤1 / 2W, wherein W is the thickness of the pole group, and W is 6mm to 30mm.

3. The battery cell according to claim 1, characterized in that: One end of the pole group connected to the body forms a convergence slope, and the height h of the convergence slope is 0.2mm to 3.5mm.

4. The battery cell according to claim 1, characterized in that: The thickness t of the bending portion is 0.1 mm to 2.5 mm.

5. The battery cell according to claim 1, characterized in that: A height H of the bent portion relative to the pole group is 1.5 mm to 5 mm.

6. The battery cell according to any one of claims 1 to 5, characterized in that: The connecting piece includes a pole connecting portion connected to the pole and a tab connecting portion connected to the tab.

7. The battery cell according to claim 6, characterized in that: A first gap is left between the tab connection portion and the inner wall of the shell extending along the length direction thereof, and the bending portion passes through the body, through the first gap and the through hole, and is arranged on the upper surface of the tab connection portion.

8. The battery cell according to claim 7, characterized in that: A second gap is left between a side of the body facing the bent portion and a side wall of the tab connecting portion, and a length a of the second gap is ≥0.2 mm.

9. The battery cell according to any one of claims 1 to 5, characterized in that: A sealing plate is disposed on the cover plate, and the sealing plate is welded to the through hole and seals the through hole.

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

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