Battery cell

Abstract

The utility model belongs to the technical field of batteries, and discloses a battery monomer, the battery monomer comprises a shell and a pole group assembly, the pole group assembly is arranged in the shell, the pole group assembly comprises a supporting element and at least two pole groups, the at least two pole groups are arranged at intervals along a first direction and are conductively connected, the first direction is the length direction of the pole groups, and the supporting element is arranged in the shell. A supporting element is arranged between every two adjacent pole groups, each supporting element comprises a supporting part, the size of each supporting part in the first direction is equal to the distance between the corresponding two adjacent pole groups, and the two opposite sides of each supporting part are fixedly connected with the corresponding two adjacent pole groups respectively. The problems of wrinkling, deformation, channeling or breakage and the like of the pole pieces due to the fact that the pole group is too long can be avoided, and the difficulty of installing the pole group assembly into the shell can be reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, and particularly relates to a battery cell. Background Art

[0002] A battery cell generally includes a battery case, a pole group, a cover plate, etc. Among them, the pole group is arranged in the battery case, and the cover plate seals the opening of the battery case.

[0003] The existing pole groups are generally short in length, which limits the capacity of the battery cell. If the length of the pole group is to be extended, the length of the pole piece needs to be extended. However, extending the length of the pole piece easily causes the pole piece to form wrinkles and the pole piece is prone to problems such as deformation, layer displacement, or fracture. In addition, if the length of the pole group is extended, the structural strength of the pole group will be reduced, thereby increasing the difficulty of installing the pole group into the battery case and being unfavorable for improving production efficiency.

[0004] Therefore, it is urgent to propose a battery cell to solve the above technical problems. Summary of the Utility Model

[0005] The purpose of the utility model is to provide a battery cell, which not only has a high capacity, but also can avoid problems such as wrinkles, deformation, layer displacement, or fracture of the pole piece caused by the excessive length of the pole group, and can also reduce the difficulty of installing the pole group assembly into the housing.

[0006] To achieve this purpose, the utility model adopts the following technical solutions:

[0007] A battery cell, comprising:

[0008] A housing;

[0009] A pole group assembly, the pole group assembly is arranged in the housing, and the pole group assembly includes a support element and at least two pole groups;

[0010] At least two pole groups are arranged at intervals along a first direction and are conductively connected, and the first direction is the length direction of the pole group;

[0011] A support element is arranged between every two adjacent pole groups. The support element includes a support portion. The dimension of the support portion in the first direction is equal to the distance between the corresponding two adjacent pole groups, and the two opposite sides of the support portion are respectively fixedly connected to the corresponding two adjacent pole groups.

[0012] Optionally, one of every two adjacent pole groups is a first pole group, and the other is a second pole group. A first pole ear protrudes from the side of the first pole group facing the second pole group, and a second pole ear protrudes from the side of the second pole group facing the first pole group. The first pole ear is fixedly connected to the second pole ear, and the support element is an insulating part.

[0013] Optionally, the first tab includes a first connecting portion, a first bending portion, and a first extending portion. The first connecting portion is connected to the first electrode group, and the first connecting portion is connected to the first extending portion through the first bending portion;

[0014] The second tab includes a second connecting portion, a second bending portion, and a second extending portion. The second connecting portion is connected to the second electrode group, and the second connecting portion is connected to the second extending portion through the second bending portion. The first extending portion and the second extending portion are fixedly connected.

[0015] Optionally, the second extending portion and the first extending portion are fixedly connected to the side of the first connecting portion facing the first connecting portion.

[0016] Optionally, the number of the supporting portions is two. In the second direction, the two supporting portions are respectively located on both sides of the first tab and the second tab. The second direction is perpendicular to the first direction.

[0017] Optionally, the supporting element further includes a partition portion. The partition portion is connected to the supporting portion. The first connecting portion, the first bending portion, and the first extending portion form a first through groove. The second connecting portion, the second bending portion, and the second extending portion form a second through groove. The axes of the first through groove and the second through groove are both parallel to the second direction. The partition portion is disposed in the first through groove and / or the second through groove. The second direction is perpendicular to the first direction.

[0018] Optionally, for at least two electrode groups, the ratio of the lengths of any two electrode groups is A, and 0.3 ≤ A ≤ 1.2.

[0019] Optionally, the battery cell further includes a cover plate assembly. An opening is provided at an end of the housing in the first direction, and the cover plate assembly covers the opening.

[0020] Optionally, the battery cell further includes an insulating film, and the insulating film is wrapped around the outer periphery of the electrode group assembly.

[0021] Optionally, the battery cell further includes a separator. The housing includes a splicing wall, and a weld seam is provided on the splicing wall. The separator is located between the inner wall of the splicing wall and the insulating film, and the orthographic projection of the weld seam on the splicing wall is located within the orthographic projection of the separator on the splicing wall.

[0022] The beneficial effects of the present utility model:

[0023] The battery cell provided by the present utility model has a pole group assembly disposed inside the housing. The pole group assembly includes a support element and at least two pole groups. The at least two pole groups are spaced apart along the length direction of the pole group and are electrically connected, which can not only increase the capacity of the battery cell but also avoid problems such as wrinkles, deformations, layer displacements, or fractures of the pole pieces caused by the excessive length of the pole group, providing guarantees for the use safety and reliability of the battery cell. In addition, a support element is provided between every two adjacent pole groups. The size of the support portion of the support element in the first direction is equal to the distance between the corresponding two adjacent pole groups, and the two opposite sides of the support portion are respectively fixedly connected to the corresponding two adjacent pole groups, so that the at least two pole groups are connected by the support element to form a pole group assembly, and the support portion plays a supporting role for the two adjacent pole groups, making the pole group assembly have a high structural strength. Furthermore, it can reduce the difficulty of installing the pole group assembly into the housing and is beneficial to improving the production efficiency of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 is an exploded structural schematic diagram of the battery cell provided by an embodiment of the present utility model;

[0025] Figure 2 is a structural schematic diagram of the support element provided by an embodiment of the present utility model;

[0026] Figure 3 is a structural schematic diagram of the pole group assembly provided by an embodiment of the present utility model;

[0027] Figure 4 is an assembled structural schematic diagram of the first pole ear and the second pole ear provided by an embodiment of the present utility model;

[0028] Figure 5 is a sectional structural schematic diagram of the pole group assembly provided by an embodiment of the present utility model.

[0029] In the figure:

[0030] 100, housing; 110, opening; 120, splicing wall; 200, support element; 210, support portion; 220, partition portion; 300, pole group; 310, first pole group; 311, first pole ear; 3111, first connection portion; 3112, first bending portion; 3113, first extension portion; 3114, first through groove; 320, second pole group; 321, second pole ear; 3211, second connection portion; 3212, second bending portion; 3213, second extension portion; 3214, second through groove; 400, cover plate assembly; 500, insulating film; 600, separator. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0031] The present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It can be understood that the specific embodiments described herein are only used to explain the present utility model, rather than limiting the present utility model. In addition, it should be noted that for the convenience of description, only the parts related to the present utility model rather than all the structures are shown in the drawings.

[0032] In the description of the present utility model, unless otherwise clearly defined and limited, the terms "connected", "connected", and "fixed" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral body; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific situations.

[0033] In the present utility model, unless otherwise clearly defined and limited, the first feature being "above" or "below" the second feature may include the direct contact between the first and second features, or may include the situation where the first and second features are not in direct contact but in contact through other features therebetween. Moreover, the first feature being "above", "above", and "on" the second feature includes that the first feature is directly above and obliquely above the second feature, or merely indicates that the horizontal height of the first feature is higher than that of the second feature. The first feature being "below", "below", and "under" the second feature includes that the first feature is directly below and obliquely below the second feature, or merely indicates that the horizontal height of the first feature is lower than that of the second feature.

[0034] In the description of this embodiment, the orientation or positional relationships such as "above", "below", "right", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of description and simplifying the operation, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and thus should not be construed as a limitation to the present utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meanings.

[0035] This embodiment provides a battery cell, which not only has a high capacity, but also can avoid problems such as wrinkles, deformation, layer displacement, or fracture of the electrode sheets caused by the excessive length of the electrode group, and can also reduce the difficulty of installing the electrode group assembly into the housing.

[0036] Specifically, as Figures 1 to 3 shown, the battery cell includes a housing 100 and an electrode group assembly. Among them, the electrode group assembly is arranged in the housing 100, and the electrode group assembly includes a support element 200 and at least two electrode groups 300. The at least two electrode groups 300 are arranged at intervals in a first direction and are electrically connected. The first direction is the length direction of the electrode group 300 ( Figure 1In the x-direction), the electrode group 300 includes a plurality of stacked electrode plates (not shown in the figure). A support element 200 is provided between every two adjacent electrode groups 300. The support element 200 includes a support portion 210. The dimension of the support portion 210 in the first direction is equal to the distance between the corresponding two adjacent electrode groups 300, and the two opposite sides of the support portion 210 are respectively fixedly connected to the corresponding two adjacent electrode groups 300.

[0037] For the battery cell provided in this embodiment, an electrode group assembly is provided in the housing 100. The electrode group assembly includes a support element 200 and at least two electrode groups 300. The at least two electrode groups 300 are arranged at intervals along the length direction of the electrode group 300 and are electrically connected. This can not only extend the length dimension of the electrode group assembly (the length can reach more than 1 meter), achieving the effect of increasing the capacity of the battery cell, but also avoid problems such as wrinkling, deformation, layer displacement or fracture of the electrode plates caused by the excessive length of the electrode group 300, providing guarantee for the use safety and reliability of the battery cell. In addition, a support element 200 is provided between every two adjacent electrode groups 300. The dimension of the support portion 210 of the support element 200 in the first direction is equal to the distance between the corresponding two adjacent electrode groups 300, and the two opposite sides of the support portion 210 are respectively fixedly connected to the corresponding two adjacent electrode groups 300, so that the at least two electrode groups 300 are connected by the support element 200 to form an electrode group assembly. And the support portion 210 plays a supporting role for the two adjacent electrode groups 300, making the electrode group assembly have a high structural strength, and then being able to reduce the difficulty of installing the electrode group assembly into the housing 100, which is beneficial to improving the production efficiency of the battery cell.

[0038] In this embodiment, the number of the electrode groups 300 is two. In other embodiments, the number of the electrode groups 300 can also be three, four or five, etc., which can be determined according to actual application requirements and will not be listed one by one here.

[0039] Optionally, the support portion 210 and the electrode group 300 are fixedly connected by means of bonding or hot melting.

[0040] Optionally, as Figures 1 to 4As shown, one of every two adjacent pole groups 300 is a first pole group 310, and the other is a second pole group 320. A first pole tab 311 protrudes from one side of the first pole group 310 facing the second pole group 320, and a second pole tab 321 protrudes from one side of the second pole group 320 facing the first pole group 310. The first pole tab 311 and the second pole tab 321 are fixedly connected, so that the first pole group 310 and the second pole group 320 are electrically connected through the first pole tab 311 and the second pole tab 321. Moreover, the direct fixed connection method of the first pole tab 311 and the second pole tab 321 eliminates other electrical connection components (such as copper bars, etc.) arranged between the first pole group 310 and the second pole group 320. On the one hand, it can reduce the resistance between the first pole group 310 and the second pole group 320, thereby reducing the internal resistance of the battery cell. On the other hand, it can reduce the structural components of the battery cell, thereby reducing the production cost. In addition, the support element 200 in this embodiment is an insulating part, so that the first pole group 310 and the second pole group 320 can only be electrically connected through the first pole tab 311 and the second pole tab 321, avoiding the short - circuit problem caused by the contact between other positions of the first pole group 310 and other positions of the second pole group 320.

[0041] Further, as Figures 1 to 4 shown, the first pole tab 311 includes a first connection part 3111, a first bending part 3112 and a first extension part 3113. The first connection part 3111 is connected to the first pole group 310, and the first connection part 3111 is connected to the first extension part 3113 through the first bending part 3112; the second pole tab 321 includes a second connection part 3211, a second bending part 3212 and a second extension part 3213. The second connection part 3211 is connected to the second pole group 320, and the second connection part 3211 is connected to the second extension part 3213 through the second bending part 3212. The first extension part 3113 and the second extension part 3213 are fixedly connected. The designs of the first bending part 3112 and the second bending part 3212 can shorten the lengths of the first pole tab 311 and the second pole tab 321, thereby reducing the volume of the battery cell and having the effect of improving the energy density of the battery cell.

[0042] On the other hand, since there is a support element 200 between the first pole group 310 and the second pole group 320, and the dimension of the support part 210 in the first direction is equal to the distance between the first pole group 310 and the second pole group 320, the support part 210 can prevent the first bending part 3112 and the second bending part 3212 from being over - bent, providing a strong guarantee for the reliability and stability of the electrical connection between the first pole group 310 and the second pole group 320.

[0043] Further, as Figures 1 to 4As shown, the second extension part 3213 is fixedly connected to the side of the first extension part 3113 facing the first connection part 3111, so as to improve the reliability of the connection between the first extension part 3113 and the second extension part 3213. Especially when the first pole group 310 and the second pole group 320 are subjected to reverse acting forces, this structural design can avoid the problem of the connection failure between the first extension part 3113 and the second extension part 3213.

[0044] Optionally, as Figures 1 to 5 shown, the support element 200 further includes a partition part 220. The partition part 220 is connected to the support part 210. The first connection part 3111, the first bending part 3112 and the first extension part 3113 form a first through groove 3114, and the second connection part 3211, the second bending part 3212 and the second extension part 3213 form a second through groove 3214. The axes of the first through groove 3114 and the second through groove 3214 are both parallel to the second direction. The second direction is perpendicular to the first direction. The design of the partition part 220 can further prevent the problem of excessive bending of the first bending part 3112. In this embodiment, the second extension part 3213 is fixedly connected to the side of the first extension part 3113 facing the first connection part 3111, that is, the second extension part 3213 is connected to the inner wall of the first through groove 3114. The partition part 220 is located between the second extension part 3213 and the first connection part 3111. This structural design has an isolating effect on the second extension part 3213 and the first connection part 3111, preventing them from contacting each other and causing a short - circuit problem.

[0045] In another embodiment, the partition part 220 can also be arranged in the second through groove 3214, and the partition part 220 is located between the first extension part 3113 and the second connection part 3211, which can prevent the problem of excessive bending of the second bending part 3212 and has an isolating effect on the first extension part 3113 and the second connection part 3211.

[0046] In still another embodiment, the partition part 220 can be arranged in both the first through groove 3114 and the second through groove 3214. The partition part 220 in the first through groove 3114 is between the second extension part 3213 and the first connection part 3111, and the partition part 220 in the second through groove 3214 is between the first extension part 3113 and the second connection part 3211.

[0047] In this embodiment, the second direction is the height direction of the pole group 300, that is Figure 1 and Figure 5 the z - direction in Figure 1 . In other embodiments, the second direction can also be the width direction of the pole group 300, that is

[0048] Optionally, as Figures 1 to 5 shown, the number of the supporting parts 210 is two, and both ends of the blocking part 220 are respectively connected to the two supporting parts 210. In the second direction ( Figure 1 and Figure 5 the z-direction in ), the two supporting parts 210 are respectively located on both sides of the first tab 311 and the second tab 321. The design of the two supporting parts 210 can improve the stability and uniformity of the supporting effect on the first electrode group 310 and the second electrode group 320, and when the sizes of the first tab 311 and the second tab 321 in the second direction are relatively large, this structural design can further reduce the problem of excessive bending of the first bending part 3112 and the second bending part 3212.

[0049] Optionally, among at least two electrode groups 300, the ratio of the lengths (the sizes of the electrode groups 300 in the first direction) of any two electrode groups 300 is A, where 0.3 ≤ A ≤ 1.2. Exemplarily, A can be 0.3, 0.5, 1.0, or 1.2, etc., to prevent the length of an individual electrode group 300 from being too long, further reducing the probability of problems such as wrinkles, deformation, layer displacement, or fracture of the electrode sheet, and further improving the structural strength of the electrode group assembly.

[0050] Optionally, among at least two electrode groups 300, the length of the longest electrode group 300 is less than or equal to 950 mm. Exemplarily, the length of the longest electrode group 300 can be 600 mm, 800 mm, 900 mm, or 950 mm, etc., to avoid problems such as wrinkles, deformation, layer displacement, or fracture of the electrode sheet. At the same time, it can also prevent the problem of low structural strength of an overly long electrode group 300.

[0051] Optionally, among at least two electrode groups 300, the length of the shortest electrode group 300 is greater than or equal to 350 mm. Exemplarily, the length of the shortest electrode group 300 can be 350 mm, 400 mm, 450 mm, or 500 mm, etc., which is convenient for the production and processing of the electrode group 300.

[0052] Optionally, as Figures 1 to 5 shown, the battery cell further includes an insulating film 500, and the insulating film 500 is wrapped around the outer periphery of the electrode group assembly to achieve an insulating effect.

[0053] Optionally, as Figures 1 to 5As shown, the battery cell further includes a cover plate assembly 400. An opening 110 is provided at an end of the housing 100 in the first direction, and the cover plate assembly 400 is covered at the opening 110 to form a sealed space inside the housing 100. In this embodiment, openings 110 are provided at both ends of the housing 100 in the first direction, and a cover plate assembly 400 is covered at each opening 110. The electrode group assembly wrapped with the insulating film 500 is inserted into the housing 100 through one of the openings 110, and then the two cover plate assemblies 400 are respectively covered at the two openings 110.

[0054] Optionally, as Figures 1 to 5 shown, the battery cell further includes a separator 600. The housing 100 includes a splicing wall 120, and a weld (not shown in the figure) is provided on the splicing wall 120. The separator 600 is located between the inner wall of the splicing wall 120 and the insulating film 500, and the orthographic projection of the weld on the splicing wall 120 is located within the orthographic projection of the separator 600 on the splicing wall 120. The setting of the separator 600 avoids the problem that the weld cuts the insulating film 500, plays a protective role for the insulating film 500, and further can avoid the short - circuit problem caused by the contact between the electrode group 300 and the splicing wall 120.

[0055] Furthermore, as Figures 1 to 5 shown, the number of the separators 600 is equal to and corresponds one - to - one with the number of the electrode groups 300.

[0056] Obviously, the above - mentioned embodiments of the present utility model are merely examples for clearly explaining the present utility model, rather than limitations on the implementation manners of the present utility model. For those of ordinary skill in the art, various obvious changes, re - adjustments and substitutions can be made without departing from the protection scope of the present utility model. It is not necessary and impossible to enumerate all the implementation manners here. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the present utility model shall be included in the protection scope of the claims of the present utility model.

Claims

1. Battery cell, characterized in that, Comprising: A housing (100); A pole group assembly, which is arranged inside the housing (100), and the pole group assembly includes a support element (200) and at least two pole groups (300); At least two of the pole groups (300) are arranged at intervals in a first direction and are conductively connected, and the first direction is the length direction of the pole group (300); A support element (200) is provided between every two adjacent pole groups (300), and the support element (200) includes a support portion (210). The dimension of the support portion (210) in the first direction is equal to the distance between the corresponding two adjacent pole groups (300), and the two opposite sides of the support portion (210) are respectively fixedly connected to the corresponding two adjacent pole groups (300).

2. The battery cell according to claim 1, wherein, One of every two adjacent pole groups (300) is a first pole group (310), and the other is a second pole group (320). A first pole tab (311) protrudes from the side of the first pole group (310) facing the second pole group (320), and a second pole tab (321) protrudes from the side of the second pole group (320) facing the first pole group (310). The first pole tab (311) is fixedly connected to the second pole tab (321), and the support element (200) is an insulating member.

3. The battery cell according to claim 2, wherein The first pole tab (311) includes a first connection portion (3111), a first bending portion (3112), and a first extension portion (3113). The first connection portion (3111) is connected to the first pole group (310), and the first connection portion (3111) is connected to the first extension portion (3113) through the first bending portion (3112); The second pole tab (321) includes a second connection portion (3211), a second bending portion (3212), and a second extension portion (3213). The second connection portion (3211) is connected to the second pole group (320), and the second connection portion (3211) is connected to the second extension portion (3213) through the second bending portion (3212). The first extension portion (3113) is fixedly connected to the second extension portion (3213).

4. The battery cell according to claim 3, wherein The second extension portion (3213) is fixedly connected to the side of the first extension portion (3113) facing the first connection portion (3111).

5. The battery cell according to claim 3, characterized in that, The number of the support portions (210) is two. In a second direction perpendicular to the first direction, the two support portions (210) are respectively located on both sides of the first pole tab (311) and the second pole tab (321).

6. The battery cell according to claim 3, characterized in that The support element (200) further includes a partition portion (220). The partition portion (220) is connected to the support portion (210). The first connecting portion (3111), the first bending portion (3112), and the first extending portion (3113) form a first through groove (3114). The second connecting portion (3211), the second bending portion (3212), and the second extending portion (3213) form a second through groove (3214). The axes of the first through groove (3114) and the second through groove (3214) are both parallel to the second direction. The partition portion (220) is disposed in the first through groove (3114) and / or the second through groove (3214). The second direction is perpendicular to the first direction.

7. The battery cell according to any one of claims 1-6, characterized in that, Among at least two of the pole groups (300), the ratio of the lengths of any two of the pole groups (300) is A, where 0.3 ≤ A ≤ 1.

2.

8. The battery cell according to any one of claims 1-6, characterized in that, The battery cell further includes a cover plate assembly (400). An opening (110) is provided at an end of the housing (100) in the first direction. The cover plate assembly (400) is disposed to cover the opening (110).

9. The battery cell according to any one of claims 1-6, characterized in that, The battery cell further includes an insulating film (500). The insulating film (500) is wrapped around the outer periphery of the pole group assembly.

10. The battery cell according to claim 9, characterized in that, The battery cell further includes a separator (600). The housing (100) includes a splicing wall (120). A weld seam is provided on the splicing wall (120). The separator (600) is located between the inner wall of the splicing wall (120) and the insulating film (500), and the orthographic projection of the weld seam on the splicing wall (120) is located within the orthographic projection of the separator (600) on the splicing wall (120).

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