Energy storage battery and battery cell thereof

Abstract

The utility model discloses a battery cell of an energy storage battery, which comprises a plurality of laminations which are laminated one by one along a first direction, and tabs are respectively arranged at the end parts of the laminations; all the laminations are divided into a plurality of lamination groups which are arranged one by one along the first direction; each lamination group comprises a plurality of laminations; tabs of the same kind of all the laminations in the lamination group are gathered in the middle area of the lamination group along the first direction to form group tabs; and all groups of tabs at the same end of the battery cell are mutually staggered along the first direction. The battery cell comprises a plurality of lamination groups, the same kind of tabs of all laminations of each lamination group are gathered in the middle area of the lamination group along the lamination arrangement direction of the laminations, and compared with the scheme that the same kind of tabs of all the laminations are gathered in one place in the prior art, the quantity of the gathered group tabs is increased, and the thickness is reduced; and each group of tabs is not easy to bend poorly after being bent, and more laminations can be connected in parallel, so that the internal resistance of the battery cell is reduced, and the discharge efficiency of the battery cell is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of energy storage batteries, and more specifically, to a battery core of an energy storage battery and also to an energy storage battery. Background Art

[0002] See also Figure 1-5 The cell of the energy storage battery includes a plurality of stacked laminates 12, and a tab 11 extends from the end of each laminate 12. The tabs 11 of the same type of all laminates 12 in the cell are aligned and gathered to the middle area of ​​the cell along the thickness direction (i.e., the direction in which the laminates are stacked). After the tabs 11 of the same type of all laminates 12 are gathered to the middle area of ​​the cell, they need to be bent and connected to the connecting sheet 13, or they need to be bent and directly welded to the top cover 14 of the cell.

[0003] However, in the existing battery cells, the overall thickness of the same type of pole ears 11 of all the stacked sheets 12 is large after being folded, while the thickness of a single pole ear 11 is small, which is prone to poor bending when the whole is bent, affecting the performance of the finished battery cell. Therefore, the number of stacked sheets 12 in the existing battery cell cannot be set to too many, which is not conducive to improving the discharge efficiency.

[0004] Therefore, how to increase the number of stacked sheets in a battery cell so that more stacked sheets can be connected in parallel, reduce the internal resistance of the battery cell, and improve the discharge efficiency of the battery cell is an urgent problem to be solved by those skilled in the art. Utility Model Content

[0005] In view of this, the utility model provides a battery cell, which includes a plurality of stacked sheets, and the same type of pole ears of all stacked sheets of each stacked sheet group are gathered in the middle area of ​​the stacked sheet group along the stacked arrangement direction of the stacked sheets. Compared with the solution in the prior art that the same type of pole ears of all stacked sheets are gathered in one place, the number of group pole ears formed after the gathering increases, the thickness of a single group pole ear is reduced, and each group pole ear after the gathering is not prone to poor bending after bending, and more stacked sheets can be connected in parallel, reducing the internal resistance of the battery cell and improving the discharge efficiency of the battery cell. The utility model also provides an energy storage battery using the above battery cell, which has low internal resistance and high discharge efficiency.

[0006] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0007] A battery cell of an energy storage battery comprises a plurality of laminates stacked one by one along a first direction, wherein the ends of the laminates are respectively provided with pole ears; all the laminates are divided into a plurality of laminate groups arranged one by one along the first direction; each of the laminate groups comprises a plurality of the laminates; the same pole ears of all the laminates in the laminate group are gathered in the middle area of ​​the laminate group along the first direction to form a group pole ear; all the group pole ears located at the same end of the battery cell are staggered with each other along the first direction.

[0008] Optionally, in the above-mentioned battery cell, the positive tabs and negative tabs of the stack are distributed at opposite ends of the stack; all the positive tabs of the stack are located on one side of the battery cell, and all the negative tabs of the stack are located on the other side of the battery cell.

[0009] Optionally, in the above-mentioned battery cell, the same type of pole tabs of different stacks are staggered along the first direction.

[0010] Optionally, in the above battery cell, all the positive electrode group tabs of the laminated stack are connected to one top cover of the battery cell through a same first connecting sheet; and all the negative electrode group tabs of the laminated stack are connected to another top cover of the battery cell through a same second connecting sheet.

[0011] Optionally, in the above-mentioned battery cell, the lamination group is an even number group, and every two of the lamination groups constitute a pair of lamination groups; the positive electrode group tabs of the two lamination groups in each pair are connected to one top cover of the battery cell through the same first connecting plate, and the negative electrode group tabs are connected to the other top cover of the battery cell through the same second connecting plate; different pairs of lamination groups are connected to different first connecting plates and different second connecting plates.

[0012] Optionally, in the above-mentioned battery cell, the stack is arranged in a shell of the battery cell, and the two ends of the shell are open; the two top covers of the battery cell are respectively sealed at the openings at both ends of the shell; the top covers are equipped with poles, and the positive electrode group tabs and negative electrode group tabs of the stack group are respectively connected to the poles of the two top covers through different connecting sheets.

[0013] Optionally, in the above battery core, the number of the laminations in each of the lamination groups is the same.

[0014] Optionally, in the above-mentioned battery core, the same type of tabs of all the laminations in the lamination group are aligned along the first direction.

[0015] Optionally, in the above-mentioned battery cell, the pole lug of the lamination in the lamination group that is not in the middle position along the first direction is bent, including a first bent portion and a second bent portion that are connected to each other; the first bent portion is connected to the lamination, and the first bent portion is parallel to the first direction; the pole lug of the lamination in the lamination group that is in the middle position along the first direction and the second bent portions of other laminations are tightly attached to each other.

[0016] Optionally, in the above-mentioned battery cell, the length of the tabs of the laminations in the lamination group gradually increases from the middle to the two ends.

[0017] An energy storage battery comprises at least one battery cell, wherein the battery cell is the battery cell described in any one of the above technical solutions.

[0018] The utility model provides a battery cell of an energy storage battery, comprising a plurality of laminates which are stacked one by one along a first direction, and pole ears are respectively arranged at the ends of each laminate; all the laminates are divided into a plurality of laminate groups which are arranged one by one along the first direction; each laminate group comprises a plurality of laminates; the same pole ears of all the laminates in the laminate group are gathered in the middle area of ​​the laminate group along the first direction to form a group pole ear; all the group pole ears located at the same end of the battery cell are staggered with each other along the first direction.

[0019] In the above-mentioned battery cell, all the laminates are divided into a plurality of laminate groups, and the pole ears of each laminate are gathered in groups respectively, and can be directly connected to the pole column of the top cover of the battery cell or connected to the pole column through a connecting sheet after being gathered and bent respectively. Compared with the scheme in the prior art that the same pole ears of all the laminates of the battery cell are gathered at one place at the same time, the thickness of each pole ear gathered at one place is reduced by increasing the number of pole ears gathered at one place, so as to avoid the situation that the pole ears gathered at one place are not bent properly when bent, and the performance of the finished battery cell is prevented; at the same time, the number of laminates can be set to be more, so that more laminates can be connected in parallel, the internal resistance of the battery cell is reduced, and the discharge efficiency of the battery cell is improved.

[0020] At the same time, in the battery cell provided by the utility model, all the groups of pole tabs located at the same end of the battery cell are staggered along the first direction, which can avoid mutual interference between the groups of pole tabs of different groups when they are folded and bent.

[0021] The utility model also provides an energy storage battery using the battery core, which has the advantages of small internal resistance and high discharge efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0023] Figure 1 It is a schematic diagram of the structure of the stacked arrangement of the battery cells in the prior art;

[0024] Figure 2 It is a schematic diagram of the same type of tabs of all stacked sheets of a battery cell in the prior art being gathered to the middle area of ​​the battery cell along the thickness direction;

[0025] Figure 3 for Figure 2 A magnified view of part A;

[0026] Figure 4 It is a structural schematic diagram of a battery cell in the prior art;

[0027] Figure 5 for Figure 4 A magnified view of part B;

[0028] Figure 6 A schematic diagram of a first assembly of multiple lamination stacks in a battery cell provided by an embodiment of the utility model;

[0029] Figure 7 for Figure 6 a side view of the structure shown;

[0030] Figure 8 for Figure 7 Enlarged view of part C;

[0031] Fig. 9 A schematic diagram of the structure of a battery cell provided in an embodiment of the utility model;

[0032] Fig.10 for Fig. 9 A magnified view of part D in the middle;

[0033] Fig.11 A second schematic diagram of assembling a plurality of lamination stacks in a battery cell provided by an embodiment of the utility model;

[0034] Fig.12 A third schematic diagram of assembling a plurality of lamination stacks in a battery cell provided by an embodiment of the utility model;

[0035] Fig.13 A fourth schematic diagram of assembling a plurality of lamination stacks in a battery cell provided by an embodiment of the utility model;

[0036] Fig.14 A fifth schematic diagram of assembling a plurality of lamination stacks in a battery cell provided by an embodiment of the utility model;

[0037] Fig.15 A sixth assembly schematic diagram of multiple lamination stacks in a battery cell provided by an embodiment of the utility model;

[0038] Fig.16 A seventh schematic diagram of assembling a plurality of lamination stacks in a battery cell provided by an embodiment of the utility model;

[0039] in, Figure 6-Figure 16 middle:

[0040] The laminated sheet group 100 ; the electrode tab 101 ; the laminated sheet 102 ; the outer shell 201 ; the top cover 202 ; and the first connecting sheet 203 . DETAILED DESCRIPTION

[0041] The utility model embodiment discloses a battery cell, which includes a plurality of stacked sheets, and the same type of pole ears of all stacked sheets of each stacked sheet group are gathered in the middle area of ​​the stacked sheet group along the stacked arrangement direction of the stacked sheets. Compared with the solution in the prior art that the same type of pole ears of all stacked sheets are gathered in one place, the number of group pole ears formed after the gathering increases, the thickness of a single group pole ear is reduced, and each gathered group pole ear is not prone to poor bending after bending, and more stacked sheets can be connected in parallel, reducing the internal resistance of the battery cell and improving the discharge efficiency of the battery cell. The utility model embodiment also discloses an energy storage battery using the above battery cell, which has low internal resistance and high discharge efficiency.

[0042] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0043] See also Figure 6-16 The embodiment of the utility model provides a battery cell of an energy storage battery, comprising a plurality of laminates 102 stacked one by one along a first direction, and pole ears are respectively provided at the ends of each laminate 102; all the laminates 102 are divided into a plurality of laminate groups 100 arranged one by one along the first direction; each laminate group 100 comprises a plurality of laminates 102; the same pole ears of all the laminates 102 in the laminate group 100 are gathered in the middle area of ​​the laminate group 100 along the first direction to form a group pole ear 101; all the group pole ears 101 located at the same end of the battery cell are staggered with each other along the first direction.

[0044] The same stack 100 has a plurality of tabs 101, including positive tabs and negative tabs. All the tabs 101 at the same end of the battery cell are staggered along the first direction, which means that the projections of all the tabs 101 at the same end of the battery cell on the first surface are neither completely nor partially overlapped; and the first surface is perpendicular to the first direction.

[0045] In the above-mentioned battery cell, all the laminates 102 are divided into a plurality of laminate groups 100, and the pole ears of each laminate 102 are gathered in groups, and can be directly connected to the pole of the top cover 202 of the battery cell or connected to the pole through a connecting sheet after being gathered and bent. Compared with the solution in the prior art that the same pole ears of all the laminates 102 of the battery cell are gathered at one place at the same time, the thickness of each group of pole ears 101 gathered at one place is reduced by increasing the number of group pole ears 101 gathered at one place, so as to avoid the situation that the group pole ears 101 gathered at one place are poorly bent when bent, thereby preventing the performance of the finished battery cell from being affected; at the same time, the number of laminates 102 can be set to be more, so that more laminates 102 can be connected in parallel, the internal resistance of the battery cell is reduced, and the discharge efficiency of the battery cell is improved.

[0046] At the same time, in the above-mentioned battery cell, all the groups of electrode tabs 101 located at the same end of the battery cell are staggered along the first direction, so as to avoid mutual interference between the groups of electrode tabs 101 of different groups when they are folded and bent.

[0047] The positive and negative tabs of the stack 102 are distributed at opposite ends of the stack 102; the positive tabs of all stacks 102 are located on one side of the battery cell, and the negative tabs of all stacks 102 are located on the other side of the battery cell, so that the positive tabs of all stacks 102 are connected to the positive pole column of one top cover in the battery cell, and the negative tabs of all stacks 102 are connected to the negative pole column of another top cover in the battery cell.

[0048] Furthermore, in the above-mentioned battery cell, the same group of tabs 101 of different laminate groups 100 are staggered along the first direction; the above-mentioned staggered along the first direction means that the projections of the same group of tabs 101 of different laminate groups 100 on the first surface neither completely overlap nor partially overlap.

[0049] In one embodiment, the positive electrode group tabs of all the laminated stacks 100 are connected to the poles of one top cover 202 of the battery cell through the same first connecting sheet 203; the negative electrode group tabs of all the laminated stacks 100 are connected to the poles of another top cover 202 of the battery cell through the same second connecting sheet.

[0050] In another embodiment, the positive electrode group tabs of each stack 100 are connected to the poles of one top cover 202 of the battery cell through different first connecting sheets 203; or, the positive electrode group tabs of some stacks 100 are connected to the poles of one top cover 202 of the battery cell through the same first connecting sheet 203, and the positive electrode group tabs of some stacks 100 are connected to the poles of the top cover 202 through different first connecting sheets 203. The negative electrode group tabs of each stack 100 are connected to the poles of another top cover 202 of the battery cell through different second connecting sheets; or, the negative electrode group tabs of some stacks 100 are connected to the poles of another top cover 202 of the battery cell through the same second connecting sheet, and the negative electrode group tabs of some stacks 100 are connected to the poles of the top cover 202 through different second connecting sheets.

[0051] In another embodiment, the positive electrode group tabs of all the laminated stacks 100 are directly connected to the poles of one top cover 202 of the battery cell; and the negative electrode group tabs of all the laminated stacks 100 are directly connected to the poles of another top cover 202 of the battery cell.

[0052] In another embodiment, the lamination groups 100 are arranged in an even number, such as 2 groups, 4 groups, 6 groups, etc.; every two lamination groups 100 constitute a pair of lamination groups 100; the positive electrode group tabs of the two lamination groups 100 in each pair are connected to the poles of one top cover 202 of the battery cell through the same first connecting plate 203, and the negative electrode group tabs are connected to the poles of the other top cover 202 of the battery cell through the same second connecting plate; different pairs of lamination groups 100 are connected to different first connecting plates 203 and different second connecting plates.

[0053] The stack 102 is arranged in the outer shell 201 of the battery cell; the outer shell 201 is annular, and the two ends of the outer shell 201 are open; the two top covers 202 of the battery cell are respectively sealed at the openings at the two ends of the outer shell 201; the top cover 202 is installed with a pole; in the scheme where the group tab 101 is connected to the top cover 202 through a connecting piece, the connecting piece is specifically connected to the pole of the top cover 202, and the positive group tab and the negative group tab of the stack group 100 are respectively connected to the poles of the two top covers 202 through different connecting pieces.

[0054] In the above-mentioned battery core, the number of laminations 102 in each lamination group 100 is the same. Of course, the number of laminations 102 in different lamination groups 100 can also be set to be different, which is not limited in this embodiment.

[0055] The same type of tabs of all the laminations 102 in the lamination stack 100 are aligned along the first direction, that is, the projections of the same type of tabs of all the laminations 102 in the lamination stack 100 on the first surface overlap.

[0056] The same group of tabs 101 of each lamination group 100 can be arranged in sequence along the second direction (the second direction is perpendicular to the first direction), that is, the same group of tabs of the lamination group 100 arranged one by one along the first direction are arranged one by one in the second direction according to this order, such as Figure 6 , 11 , 14. The same group of tabs 101 of each lamination group 100 can also be arranged non-sequentially along the second direction, such as Fig.12 , 13 , 15, and 16.

[0057] The tabs of the laminations 102 that are not in the middle position along the first direction in the lamination stack 100 are bent, including a first bent portion and a second bent portion that are connected to each other. The first bent portion is connected to the lamination 102, and the first bent portion is parallel to the first direction; it should be noted that the parallel here includes completely parallel or nearly parallel. The tabs of the laminations 102 that are in the middle position along the first direction in the lamination stack 100, and the second bent portions of other laminations 102 that are not in the middle position along the first direction are pressed against each other. The number of laminations 102 that are in the middle position along the first direction in the lamination stack 100 can be set to 1, 2, 3, etc., which is not limited in this embodiment.

[0058] In the battery cell provided in this embodiment, by setting the tabs of the laminations 102 that are not in the middle position of the lamination group 100 along the first direction to be bent, the second bent portion of each lamination 102 and the tabs of the lamination 102 in the middle position along the first direction are closely attached to each other, so that the tabs of all the laminations 102 in the group are completely retracted.

[0059] The same type of tabs of all the laminations 102 in the lamination stack 100 may be arranged to be only close to each other, or may be arranged to be welded to each other, or the same type of tabs of any two adjacent laminations 102 in the lamination stack 100 may be connected by conductive adhesive.

[0060] The length of the tab of the lamination 102 in the lamination stack 100 increases gradually from the middle of the first direction to the two ends of the first direction. The length of the tab refers to the length from the end of the tab connected to the lamination 102 to the end away from the lamination 102.

[0061] Those skilled in the art can understand that, in the production process of the battery cell, the stacking sheets 102 need to be prepared first, and in the prepared stacking sheets 102 products, the tabs are coplanar with the stacking sheets 102, and the length of the tabs in all stacking sheets 102 (i.e., the distance from the end of the tab connected to the stacking sheets 102 to the end away from the stacking sheets 102) is the same. After the stacking sheets 102 are stacked one by one along the first direction, the tabs need to be folded.

[0062] See also Figure 3In the prior art, after all the laminations 12 are stacked along the first direction, the pole lugs 11 are folded together, wherein the height dimension of the pole lug 11 located at the middle position along the first direction is the highest, which is L1+L2; along the middle position to the two ends, the height dimension of the pole lug 11 gradually decreases, wherein the height dimension of the pole lug at the end is the lowest, which is L2. In order to facilitate the connection of the folded pole lug 11 with the connecting plate or the top cover, the L1 area needs to be cut off, and the L1 area is the pole lug shaping area; the remaining L2 area is used for welding with the connecting plate or the top cover, which is recorded as the welding area. In order to facilitate welding, the size of the welding area L2 is generally set to 10mm. The two sides of the center position of all the laminations 12 along the first direction are respectively recorded as convergence areas, and the pole lugs 11 of the laminations 12 in the convergence area need to converge to the center position. The thickness of all stacking sheets 12, L5, is equal to the thickness of the convergence area, L3, and the thickness of the convergence area, L4. The thickness of the convergence area, L3, is equal to the thickness of the convergence area, L4, and the ear shaping area, L1. The length of the welding area, L2, is about 10 mm. The thickness of the battery cell, × 0.9, is approximately L5. Therefore, the overall length of the ear 11, = L1 + L2, = the thickness of the battery cell, × 0.9 / 2, + 10 mm, = 0.45 × the thickness of the battery cell, + 10. It can be seen that the length of the ear 11 (L1 + L2) is positively correlated with the thickness of the battery cell. In the prior art, when the length of the ear 11 is greater than 26 mm, since the thickness of the ear 11 itself is less than 12 μm, the ear 11 will bend and other defects will occur, affecting the performance of the finished battery cell, resulting in the overall thickness of the battery cell in the prior art being generally less than 30 mm. The limited thickness of the battery cell also results in the number of stacking sheets 12 not being able to be set to too many.

[0063] In the battery cell provided in this embodiment, a battery cell having two stacking sheets 102 with the same number of stacking sheets 102 is used as an example for description. Figure 8 , the thickness of all the laminations 102 is H7 = convergence area H3 + convergence area H4 + convergence area H5 + convergence area H6, convergence area H3 = convergence area H4 = convergence area H5 = convergence area H6 = pole ear shaping area H1, the length of the welding area H2 is about 10mm, the thickness of the battery cell × 0.9 ≈ H7, the overall length of the pole ear = H1 + H2 = battery cell thickness × 0.9 ÷ (2 × n) + 10mm = 0.45 × battery cell thickness ÷ n + 10, where n refers to the number of groups of the lamination group 100; it can be seen that when the overall length of the pole ear remains consistent with the prior art, the more groups of the laminations 102, the thicker the battery cell. It can be seen that the battery cell provided in this embodiment can break through the thickness limit of the existing battery cell and can be provided with more laminations 102.

[0064] In addition, the battery cell provided in this embodiment can increase the thickness compared with the existing battery cell, which can reduce the proportion of structural parts, reduce costs, and improve the energy density of the battery cell.

[0065] An embodiment of the utility model further provides an energy storage battery, comprising at least one battery cell, which is the battery cell provided in the above embodiment.

[0066] In a solution where the energy storage battery includes a plurality of battery cells, the battery cells are preferably connected in series one by one.

[0067] The energy storage battery provided in this embodiment uses the battery cell provided in the above embodiment, and has the effects of small internal resistance and high discharge efficiency. Of course, the energy storage battery provided in this embodiment also has other effects related to the battery cell provided in the above embodiment, which will not be repeated here.

[0068] The various embodiments in this specification are described in a progressive manner, and each embodiment focuses on the differences from other embodiments. The same or similar parts between the various embodiments can be referenced to each other.

[0069] The above description of the disclosed embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery cell for an energy storage battery, characterized in that: It comprises a plurality of laminates stacked one by one along a first direction, and each end of the laminate is provided with a pole ear; all the laminates are divided into a plurality of laminate groups arranged one by one along the first direction; each of the laminate groups comprises a plurality of the laminates; the same pole ears of all the laminates in the laminate group are gathered in the middle area of ​​the laminate group along the first direction to form a group of pole ears; all the group of pole ears located at the same end of the battery cell are staggered with each other along the first direction.

2. The battery cell according to claim 1, characterized in that: The positive tabs and negative tabs of the stack are distributed at opposite ends of the stack; all the positive tabs of the stack are located on one side of the battery core, and all the negative tabs of the stack are located on the other side of the battery core.

3. The battery cell according to claim 2, characterized in that: The same type of pole lugs in different lamination groups are staggered with each other along the first direction.

4. The battery cell according to claim 3, characterized in that: All the positive electrode group tabs of the laminated stack are connected to one top cover of the battery cell through a same first connecting sheet; and all the negative electrode group tabs of the laminated stack are connected to another top cover of the battery cell through a same second connecting sheet.

5. The battery cell according to claim 3, characterized in that: The lamination group is an even number, and every two lamination groups constitute a pair of lamination groups; the positive electrode group tabs of the two lamination groups in each pair are connected to one top cover of the battery cell through the same first connecting plate, and the negative electrode group tabs are connected to the other top cover of the battery cell through the same second connecting plate; different pairs of lamination groups are connected to different first connecting plates and different second connecting plates.

6. The battery cell according to claim 2, characterized in that: The stack is arranged in the outer shell of the battery cell, and the two ends of the outer shell are open; the two top covers of the battery cell are respectively sealed at the openings at the two ends of the outer shell; the top covers are installed with poles, and the positive electrode group tabs and negative electrode group tabs of the stack group are respectively connected to the poles of the two top covers through different connecting sheets.

7. The battery cell according to claim 1, characterized in that: The number of the laminations in each lamination group is the same.

8. The battery cell according to claim 1 or 7, characterized in that: The same type of tabs of all the laminations in the lamination group are aligned along a first direction.

9. The battery cell according to claim 1, characterized in that: The tabs of the laminations in the lamination group that are not in the middle along the first direction are bent, and include a first bent portion and a second bent portion that are connected to each other; the first bent portion is connected to the laminations, and the first bent portion is parallel to the first direction; The tabs of the laminations in the middle of the lamination group along the first direction and the second bent portions of other laminations are pressed tightly one by one.

10. The battery cell according to claim 1, characterized in that: The length of the tabs of the laminations in the lamination stack increases gradually from the middle to the two ends.

11. An energy storage battery, characterized in that: The invention comprises at least one battery cell, wherein the battery cell is the battery cell according to any one of claims 1 to 10.

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