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. Wherein the battery cell comprises a shell, one side of which is provided with a pair of pole columns; the pole group is arranged in the shell and is provided with a pair of pole lugs, and the pair of pole lugs and the pair of pole columns are arranged in a staggered manner; the tab 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 pair of connecting sheets are arranged on the pole group and used for connecting the pole and the tab, and the connecting sheets are fixed in a space defined by the body and the bending part and are attached to the lower surface of the bending part. According to the utility model, the poles and the tabs are arranged in a staggered manner, and the space in other directions in the shell is utilized, so that the internal space of the shell, which is occupied by the poles and the tabs in the height direction of the shell in a connected state, is shortened, the utilization rate of the internal space of the shell is improved, and further, the battery cell can store more energy under the same volume. And secondly, the tabs are connected with the connecting sheets through the bending parts, so that the operation difficulty of connecting the tabs with the connecting sheets can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates 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 pole ear of the pole group. It ensures the smooth flow of current between the pole column and the pole 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 pole ear adopted in the related art is not only complicated to operate, but also occupies a relatively large 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 pole ear in the related art is complicated and occupies a relatively large internal space of the battery cell.

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

[0006] A housing with a pair of pole columns provided on one side;

[0007] A pole group disposed in the housing and provided with a pair of pole ears, the pair of pole ears being arranged in a staggered manner with the pair of pole columns; the pole ear includes a body connected to the pole group and a bent portion bent from the end of the body towards one side;

[0008] A pair of connecting pieces disposed on the pole group for connecting the pole column and the pole ear, the connecting piece being fixed in the space defined by the body and the bent portion and fitting with the lower surface of the bent portion;

[0009] A plastic plate disposed in the housing and located above the pair of connecting pieces, the plastic plate being provided with a pair of pole column mounting holes, the pair of pole column mounting holes corresponding to the pair of pole columns one by one, and the pole column being connected to the connecting piece by passing through the pole column mounting hole; the plastic plate extends downward at opposite ends along its length direction to form flanges.

[0010] Beneficial effects: In the present utility model, the terminal post is integrated on the housing, indicating that the housing in the present utility model is an integrally formed structure. In this way, the gaps on the housing can be reduced, improving the dust and water protection level of the battery cell and the structural strength of the housing itself. In addition, in the present utility model, the terminal post and the tab are arranged in a staggered manner, making use of the space in other directions inside the housing. Compared with the existing connection piece and tab both arranged along the axial direction of the terminal post, the internal space of the housing occupied by the connection piece and the tab in the height direction of the housing in the connected state is reduced, improving the utilization rate of the internal space of the housing. Furthermore, more energy can be stored in the battery cell with the same volume. Secondly, the tab is connected to the connection piece through a bending portion, which can reduce the operation difficulty of connecting the tab and the connection piece and also reduce the occupation of the internal space of the housing when they are in the connected state. Further, making the connection piece fit the lower surface of the bending portion helps to ensure good electrical contact between the connection piece and the tab, reducing the contact resistance and improving the electrical conductivity of the battery cell. In addition, by providing a flanging on the plastic plate, the anti-deformation ability of the plastic plate can be improved, ensuring that the plastic plate is closely attached to the inner surface of the housing.

[0011] In an optional embodiment, the connection piece includes a terminal post connection portion connected to the terminal post and a tab connection portion connected to the tab, and a transition connection portion is formed between the tab connection portion and the terminal post connection portion.

[0012] Beneficial effects: Since the tab and the terminal post in the present utility model are arranged in a staggered manner, the connection piece is divided into a terminal post connection portion and a tab connection portion, enabling the connection piece to be adapted to the positions of the tab and the terminal post, thereby connecting the tab and the terminal post and realizing the smooth flow of current between the tab and the terminal post. In addition, by forming a transition connection portion between the tab connection portion and the terminal post connection portion, the stress concentration phenomenon between the tab connection portion and the terminal post connection portion can be avoided, ensuring the connection strength between the two.

[0013] In an optional embodiment, the number of the electrode groups is four, and the four electrode groups are arranged side by side along the width direction of the housing; a notch extending along the length direction of the electrode group is provided on the tab connection portion, the notch divides the tab connection portion into two sub-connection portions, and tabs are provided on the opposite sides of each sub-connection portion along the width direction of the electrode group. The bending portions of the tabs on the opposite sides are bent towards each other and connected to the upper surface of the corresponding sub-connection portion.

[0014] Beneficial effects: Since the welding method of the bending portion and the connection piece can adopt ultrasonic welding, compared with taking the tab connection portion as a whole, in the present utility model, the tab connection portion is divided into two sub-connection portions by using the notch, which can avoid the influence of the vibration generated during the ultrasonic welding process on the entire tab connection portion, ensuring the stability and quality of the welding of each sub-connection portion and the corresponding tab.

[0015] In an alternative embodiment, there is a gap between the ends of the bent portions on the opposite sides that are close to each other.

[0016] Beneficial effects: Compared with stacking the bent portions of two tab ears on one connecting piece, the present utility model leaves a gap between the ends of the bent portions on the opposite sides that are close to each other, which can reduce the thickness when the two tab ears are connected to one connecting piece, that is, reduce the occupation of the internal space of the housing and improve the energy density of the battery cell.

[0017] In an alternative embodiment, the length of the gap between the side of the body facing the bent portion and the side wall of the sub-connecting portion is ≥ 0.2 mm.

[0018] Beneficial effects: By defining the size of the gap length, the present utility model can, on the one hand, avoid interference between the tab ear and the connecting piece, and on the other hand, prevent the connecting piece from tearing the tab ear.

[0019] In an alternative embodiment, a transition fillet is formed at the connection between the body and the bent portion, and the radius R of the transition fillet is 0.1 mm to 0.3 mm.

[0020] Beneficial effects: By providing the transition fillet, the structural strength of the tab ear can be ensured and the tab ear can be prevented from being torn.

[0021] In an alternative embodiment, the connection between the body and the electrode group is biased towards the side of the electrode group, and the offset W ≤ 1 / 2T1, where T1 is the thickness of the electrode group and T1 is 6 mm to 30 mm.

[0022] Beneficial effects: By setting the offset W within a reasonable range, the present utility model can ensure the flatness of the end face of the bent portion after folding, omit the tab ear die-cutting process, reduce the use cost and improve the production efficiency.

[0023] In an alternative embodiment, a converging inclined surface is formed at one end of the electrode group connected to the body, and the height h of the converging inclined surface is 0.2 mm to 3.5 mm.

[0024] 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 tab ear after folding and enable the electrode group to have a certain load-bearing capacity.

[0025] In an alternative embodiment, the thickness T2 of the bent portion is 0.1 mm to 2.5 mm.

[0026] Beneficial effects: By setting the thickness T2 of the bent portion within a reasonable range, the present 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.

[0027] In a second aspect, the present utility model also provides a battery pack, comprising: a plurality of the above-described battery cells.

[0028] Beneficial effects: By adopting the above-described battery cells, the battery pack of the present utility model can improve its own space utilization rate, so that without changing its own volume, it can improve its own energy density, extend its own usage time or reduce the charging frequency. In addition, the battery pack of the present utility model has all the advantages of the above-described 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 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, without creative efforts, other drawings can also be obtained based on these drawings.

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

[0031] Figure 2 is Figure 1 a schematic cross-sectional view of the battery cell shown;

[0032] Figure 3 is Figure 1 a schematic structural diagram of the battery cell shown without assembling the sealing plate;

[0033] Figure 4 is Figure 1 a schematic structural diagram of the battery cell shown without assembling the housing;

[0034] Figure 5 is Figure 4 a side view of [];

[0035] Figure 6 is Figure 5 a partial enlarged view of A shown in [];

[0036] Figure 7 It is a partial structural diagram of a pole group in an embodiment of the present utility model.

[0037] Description of the Reference Numerals:

[0038] 1. Housing; 101. Terminal post; 102. Through hole; 103. Sealing plate; 104. Explosion-proof valve; 2. Electrode group; 201. Tab; 2011. Body; 2012. Bent portion; 2013. Transition fillet; 202. Converging inclined surface; 3. Connecting piece; 301. Terminal post connecting portion; 302. Tab connecting portion; 3021. Notch; 3022. Sub-connecting portion; 303. Transition connecting portion; 4. Plastic plate; 401. Flange. 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. 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.

[0040] In view of the problem that the connection manner between the connecting piece and the tab in the related art 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.

[0041] The following combines Figures 1 to 7 , and describes the embodiments of the present utility model.

[0042] According to the embodiments of the present utility model, on the one hand, as Figures 1 to 4 shown, a battery cell is provided, including: a housing 1, an electrode group 2, a pair of connecting pieces 3, and a plastic plate 4.

[0043] Specifically, a pair of terminal posts 101 are provided on one side of the housing 1; the electrode group 2 is disposed in the housing 1 and is provided with a pair of tabs 201, and the pair of tabs 201 are arranged in a staggered manner with the pair of terminal posts 101; the tab 201 includes a body 2011 connected to the electrode group 2 and a bent portion 2012 bent from the end of the body 2011 toward one side; a pair of connecting pieces 3 are disposed on the electrode group 2 for connecting the terminal posts 101 and the tabs 201, and the connecting piece 3 is fixed in the space defined by the body 2011 and the bent portion 2012 and is in contact with the lower surface of the bent portion 2012; the plastic plate 4 is disposed in the housing 1 and above the pair of connecting pieces 3, the plastic plate 4 is provided with a pair of terminal post mounting holes, and the pair of terminal post mounting holes correspond to the pair of terminal posts 101 one by one, and the terminal posts 101 are connected to the connecting piece 3 by passing through the terminal post mounting holes; the plastic plate 4 extends downward at opposite ends along its length direction to form flanges 401.

[0044] In this embodiment, the terminal post 101 is integrated on the housing 1, indicating that the housing 1 in this embodiment is an integrally formed structure. In this way, the gaps on the housing 1 can be reduced, improving the dust and water protection level of the battery cell and the structural strength of the housing 1 itself. In addition, in this embodiment, the terminal post 101 and the tab 201 are arranged in a staggered manner, making use of the space in other directions inside the housing 1. Compared with the existing connection piece 3 and tab 201 both being arranged along the axial direction of the terminal post 101, the internal space of the housing 1 occupied by the connection piece 3 and the tab 201 in the height direction of the housing 1 in the connected state is reduced, improving the utilization rate of the internal space of the housing 1. Furthermore, more energy can be stored by the battery cell under the same volume. Secondly, the tab 201 is connected to the connection piece 3 through the bending part 2012, which can reduce the operation difficulty of connecting the tab 201 and the connection piece 3 and also reduce the occupation of the internal space of the housing 1 when they are in the connected state. Further, making the connection piece 3 fit the lower surface of the bending part 2012 helps to ensure good electrical contact between the connection piece 3 and the tab 201, reducing the contact resistance and improving the electrical conductivity of the battery cell. In addition, by providing the flanging 401 on the plastic plate 4, the anti-deformation ability of the plastic plate 4 can be improved, ensuring that the plastic plate 4 fits tightly with the inner surface of the housing 1.

[0045] It should be noted that the height direction of the housing 1 and the length direction of the plastic plate 4 in this embodiment are consistent with the directions shown in Figure 1 the figure.

[0046] According to an embodiment of the present invention, as Figures 4 to 6 shown, the connection piece 3 includes a terminal post connection part 301 connected to the terminal post 101 and a tab connection part 302 connected to the tab 201. A transition connection part 303 is formed between the tab connection part 302 and the terminal post connection part 301. Since the tab 201 and the terminal post 101 in this embodiment are arranged in a staggered manner, the connection piece 3 is divided into the terminal post connection part 301 and the tab connection part 302, which can make the position of the connection piece 3 adapt to the tab 201 and the terminal post 101, so that the tab 201 and the terminal post 101 can be connected, realizing the smooth flow of current between the tab 201 and the terminal post 101. In addition, by forming the transition connection part 303 between the tab connection part 302 and the terminal post connection part 301, the stress concentration phenomenon between the tab connection part 302 and the terminal post connection part 301 can be avoided, ensuring the connection strength between the two.

[0047] According to an embodiment of the present invention, as Figures 4 to 6As shown, the number of the electrode groups 2 is four, and the four electrode groups 2 are arranged side by side in the width direction of the housing 1; a notch 3021 extending in the length direction of the electrode group 2 is provided on the ear connecting portion 302, and the notch 3021 divides the ear connecting portion 302 into two sub-connecting portions 3022. Ear tabs 201 are provided on opposite sides of each sub-connecting portion 3022 in the width direction of the electrode group 2, and the bent portions 2012 of the ear tabs 201 on the opposite sides are bent towards each other and connected to the upper surface of the corresponding sub-connecting portion 3022. Since the welding method of the bent portion 2012 and the connecting piece 3 can adopt ultrasonic welding, compared with taking the ear connecting portion 302 as a whole, in this embodiment, using the notch 3021 to divide the ear connecting portion 302 into two sub-connecting portions 3022 can avoid the influence of the vibration generated during ultrasonic welding on the entire ear connecting portion 302, and ensure the stability and quality of the welding of each sub-connecting portion 3022 and the corresponding ear tab 201.

[0048] It should be noted that in this embodiment, the width direction of the housing 1 and the length direction of the electrode group 2 are Figure 1 consistent with the directions shown in

[0049] In addition, in order to reserve an operation space for the operator in advance to facilitate the subsequent connection of the ear tab 201 and the connecting piece 3, in a specific embodiment, as shown in Figure 1 and Figure 2 a pair of welding through holes 102 are further provided on one side of the housing 1 where the pole column 101 is provided. The pair of welding through holes 102 are located between the pair of pole columns 101 and are arranged in one-to-one correspondence with the pair of ear tabs 201. It can be understood that since the plastic plate 4 is located above the pair of connecting pieces 3, in order to avoid interference of the plastic plate 4 on the connection between the ear tab 201 and the connecting piece 3, through holes communicating with the pair of welding through holes 102 can be opened at positions corresponding to the plastic plate 4 and the pair of welding through holes 102.

[0050] Furthermore, as shown in Figure 1 and Figure 2 in order to improve the sealing performance of the housing 1, a sealing plate 103 for sealing the above-mentioned welding through holes 102 can be provided on the housing 1. In addition, in order to improve the use safety of the battery cell, an explosion-proof valve 104 can also be provided on the housing 1. Exemplarily, in one example, as shown in Figures 1 to 3 the explosion-proof valve 104 is located between the pair of welding through holes 102.

[0051] According to an embodiment of the present invention, as shown in Figure 4As shown, there is a gap between the ends of the bent portions 2012 on the opposite sides that are close to each other. Compared with stacking the bent portions 2012 of the two tab ears 201 on one connecting piece 3 together, in this embodiment, leaving a gap between the ends of the bent portions 2012 on the opposite sides that are close to each other can reduce the thickness when the two tab ears 201 and one connecting piece 3 are in a connected state, that is, reduce the occupation of the internal space of the housing 1 and improve the energy density of the battery cell.

[0052] According to an embodiment of the present invention, as Figure 7 shown, the gap length between the side of the body 2011 facing the bent portion 2012 and the side wall of the sub-connecting portion 3022 is ≥ 0.2 mm. By limiting the size of the gap length in this embodiment, on the one hand, it can avoid interference between the tab ear 201 and the connecting piece 3, and on the other hand, it can prevent the connecting piece 3 from tearing the tab ear 201.

[0053] According to an embodiment of the present invention, as Figure 7 shown, a transition fillet 2013 is formed at the connection between the body 2011 and the bent portion 2012, and the radius R of the transition fillet 2013 is 0.1 mm to 0.3 mm. By providing the transition fillet 2013 at the connection between the body 2011 and the bent portion 2012 in this embodiment, the structural strength of the tab ear 201 can be improved, and the problem of stress concentration of the tab ear 201 can be avoided. Further, the angle of the transition fillet 2013 is limited within a relatively reasonable range to avoid excessive occupation of the internal space of the housing 1.

[0054] According to an embodiment of the present invention, as Figure 7 shown, the connection between the body 2011 and the battery cell group 2 is biased towards the side of the battery cell group 2, and the offset W ≤ 1 / 2T1, where T1 is the thickness of the battery cell group 2, and T1 is 6 mm to 30 mm. By setting the offset W within a reasonable range in this embodiment, the flatness of the end face of the bent portion 2012 after folding can be ensured, the die-cutting process of the tab ear 201 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 bent portion 2012 is as Figure 7 shown by S in

[0055] According to an embodiment of the present invention, as Figure 7 shown, a converging inclined surface 202 is formed at the end of the battery cell group 2 connected to the body 2011, and the height h of the converging inclined surface 202 is 0.2 mm to 3.5 mm. Since the height of the converging inclined surface 202 is determined by the thickness of the battery cell group 2, by setting the height of the converging inclined surface 202 within a reasonable range, the folded tab ear 201 can be compacted, and the battery cell group 2 can have a certain load-bearing capacity.

[0056] It should be noted that, as Figure 7As shown, since a converging inclined surface 202 is formed at one end where the electrode group 2 is connected to the main body 2011, the position of the tab connection part 302 in the height direction of the housing 1 is higher than the position of the pole connection part 301 in the height direction of the housing 1.

[0057] According to an embodiment of the present invention, as Figure 7 shown, the thickness T2 of the bending part 2012 is 0.1 mm to 2.5 mm. In this embodiment, the thickness T2 of the bending part 2012 is set within a reasonable range, which can further save the space in the height direction of the electrode group 2 and improve the space utilization rate of the battery cell.

[0058] It should be noted that in this embodiment, the height direction of the electrode group 2 is consistent with the height direction of the housing 1.

[0059] In one embodiment, as Figure 7 shown, the height H of the bending part 2012 relative to the electrode group 2 is 1.5 mm to 5 mm. It can 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 part 2012, and improve the space utilization rate of the battery cell.

[0060] According to an embodiment of the present invention, on the other hand, a battery pack is also provided, including: a plurality of the above-mentioned battery cells. By adopting the above-mentioned battery cells, the battery pack of this embodiment can improve its own space utilization rate, so that without changing its own volume, it can improve its energy density, extend its usage time or reduce the charging frequency. In addition, the battery pack of this embodiment has all the advantages of the above-mentioned battery cells, which will not be elaborated here.

[0061] It should be noted that the battery cells in this embodiment can be, but are not limited to, lithium-ion batteries, lithium manganate batteries, and nickel cobalt manganese ternary material batteries. Specifically, taking lithium-ion batteries as an example, the battery pack in this embodiment can be formed by connecting a plurality of lithium-ion batteries in series, or by connecting a plurality of lithium-ion batteries in parallel, or by a combination of series and parallel connections of a plurality of lithium-ion batteries. Specific adjustments can be made according to the actual application scenarios and requirements, and the present invention does not make specific limitations in this regard. Secondly, a plurality of battery cells can be grouped and electrically connected through a bus bar to form a plurality of battery cell modules, and a plurality of battery cell modules form a battery pack.

[0062] In addition, to realize 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 the other necessary modules or components included in the battery pack can be selected from any suitable existing structures. For the sake of clearly and briefly explaining the technical solutions provided in this embodiment, the above parts will not be elaborated here, and the accompanying drawings of the specification have also been correspondingly simplified. However, it should be understood that the scope of the present invention is not limited thereby.

[0063] 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 fall within the scope defined by the appended claims.

Claims

1. A battery cell, characterized in that: include: A housing, with a pair of poles disposed on one side; A pole group is arranged in the shell and is provided with a pair of pole ears, wherein the pair of pole ears are staggered with the pair of pole posts; the pole ears include a body connected to the pole group and a bending portion bent toward one side from the end of the body; A pair of connecting pieces, arranged on the pole group, for connecting the pole column and the pole lug, the connecting pieces being fixed in the space defined by the body and the bent portion and being in contact with the lower surface of the bent portion; A plastic plate is arranged in the shell and located above the pair of connecting plates. The plastic plate is provided with a pair of pole mounting holes, the pair of pole mounting holes correspond to the pair of poles one by one, and the poles are connected to the connecting plates by passing through the pole mounting holes; the opposite ends of the plastic plate along the length direction thereof extend downward to form flanges.

2. The battery cell according to claim 1, characterized in that: The connecting piece includes a pole connecting portion connected to the pole and a pole tab connecting portion connected to the pole tab, and a transition connecting portion is formed between the pole tab connecting portion and the pole connecting portion.

3. The battery cell according to claim 2, characterized in that: There are four pole groups, which are arranged side by side along the width direction of the shell; a notch extending along the length direction of the pole group is provided on the pole ear connecting portion, and the notch separates the pole ear connecting portion into two sub-connecting portions, and each of the sub-connecting portions is provided with pole ears on opposite sides along the width direction of the pole group, and the bending portions of the pole ears on the opposite sides are bent toward each other and connected to the corresponding upper surfaces of the sub-connecting portions.

4. The battery cell according to claim 3, characterized in that: A gap is left between the ends of the bending portions on the opposite sides that are close to each other.

5. The battery cell according to claim 3, characterized in that: The length of the gap between the side of the main body facing the bending portion and the side wall of the sub-connecting portion is ≥0.2 mm.

6. The battery cell according to any one of claims 1 to 5, characterized in that: A transition fillet is formed at a connection between the main body and the bending portion, and a radius R of the transition fillet is 0.1 mm to 0.3 mm.

7. The battery cell according to any one of claims 1 to 5, 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 W is ≤ 1 / 2T1, wherein T1 is the thickness of the pole group, and T1 is 6 mm to 30 mm.

8. The battery cell according to any one of claims 1 to 5, 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.

9. The battery cell according to any one of claims 1 to 5, characterized in that: The thickness T2 of the bending portion is 0.1 mm to 2.5 mm.

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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