Battery cell and battery module

Abstract

The utility model belongs to battery technical field discloses a kind of battery cell and battery monomer, the battery cell is roll-shaped, including first pole piece and second pole piece, at least two first tabs are provided on first pole piece, at least two second tabs are provided on second pole piece, first pole piece and second pole piece are stacked and wound to form battery cell, along the axial direction of battery cell, at least two first tabs and at least two second tabs are located on the same side of battery cell, the battery cell structure can improve the uniformity of current distribution on battery cell, also can improve the internal space utilization of battery monomer shell, conducive to realizing battery cell large rate discharge and fast charging, also conducive to improving the volumetric energy density of battery monomer.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, and in particular to a battery cell and a battery unit. Background Technology

[0002] Button batteries often use a single tab structure: a positive tab is welded to the head or tail of the positive electrode, and a negative tab is welded to the head or tail of the negative electrode.

[0003] This single-tab structure means that the electrode and the tab have only one connection point. During battery charging and discharging, the problem of uneven current distribution is very obvious: the current density in the area of ​​the electrode near the tab is significantly higher than the current density in the area of ​​the electrode far from the tab. This will cause an imbalance in the reaction dynamics of the local active material in the electrode, which is not conducive to high-rate discharge and fast charging of the battery.

[0004] In addition, the positive and negative tabs of the button cell are often distributed on both sides of the core axis, which means that space needs to be reserved at both ends of the battery case axis to accommodate the tabs. This structure reduces the utilization rate of the internal space of the battery case and is not conducive to improving the volumetric energy density of the button cell.

[0005] Therefore, there is an urgent need to propose a new type of battery cell and battery unit to solve the above-mentioned technical problems. Utility Model Content

[0006] The first objective of this invention is to provide a battery cell structure that can improve the uniformity of current distribution on the battery cell and also improve the utilization rate of the internal space of the battery cell casing.

[0007] To achieve this objective, the present invention adopts the following technical solution:

[0008] The battery cell is in a coil shape and includes:

[0009] The first electrode plate has at least two first electrode tabs;

[0010] The second electrode has at least two second tabs. The first electrode and the second electrode are stacked and wound together to form a battery cell. Along the axial direction of the battery cell, at least two first tabs and at least two second tabs are located on the same side of the battery cell.

[0011] Optionally, at least two first electrode tabs are evenly distributed on the first electrode along the winding direction of the first electrode, and at least two second electrode tabs are evenly distributed on the second electrode along the winding direction of the second electrode.

[0012] Optionally, along the winding direction of the first electrode sheet, the first electrode tab located at the non-end of the first electrode sheet is a first middle electrode tab, and the number of first middle electrode tabs is at least one. The first electrode sheet includes a first current collector and a first active material layer disposed on the first current collector. The first active material layer is provided with a first notch region, and the number of first notch regions is the same as the number of first middle electrode tabs. Each first middle electrode tab is disposed on the first current collector through a corresponding first notch region.

[0013] Along the winding direction of the second electrode sheet, the second electrode tab located at the non-end of the second electrode sheet is the second middle electrode tab. The number of second middle electrode tabs is at least one. The second electrode sheet includes a second current collector and a second active material layer disposed on the second current collector. The second active material layer is provided with a second notch region. The number of second notch regions is the same as the number of second middle electrode tabs. Each second middle electrode tab is disposed on the second current collector through a corresponding second notch region.

[0014] Optionally, along the radial direction of the battery cell, any first tab and any second tab do not overlap. The first tab includes a first connecting portion and a second connecting portion connected together. The first connecting portion is connected to the first electrode plate. The second connecting portion extends out of the end of the battery cell and is bent in a direction toward the battery cell axis. The second tab includes a third connecting portion and a fourth connecting portion connected together. The third connecting portion is connected to the second electrode plate. The fourth connecting portion extends out of the end of the battery cell and is bent in a direction away from the battery cell axis.

[0015] The second objective of this invention is to provide a battery cell that exhibits high uniformity of current distribution during charging and discharging, and also has a high volumetric energy density.

[0016] To achieve this objective, the present invention adopts the following technical solution:

[0017] The battery cell includes a casing, a cover assembly, and the aforementioned battery cell. The casing has an opening, and the battery cell is disposed inside the opening. The cover assembly includes a cover body, which seals the opening of the opening.

[0018] Optionally, both the first tab and the second tab extend from the side of the cell facing the cover plate body.

[0019] Optionally, the second electrode tab includes a third connecting part and a fourth connecting part connected to each other. The third connecting part is connected to the second electrode plate, and the fourth connecting part extends out of the end of the battery cell and bends in a direction away from the battery cell axis. The end of the fourth connecting part away from the third connecting part is clamped between the cover plate body and the inner wall of the opening.

[0020] Optionally, the fourth connecting part sandwiched between the cover plate body and the inner wall of the opening is a fixing area, and the fixing areas of at least two second pole ears are evenly distributed along the circumference of the cover plate body.

[0021] Optionally, the cover plate assembly further includes a pole post, which is sealed and insulated through the cover plate body. The first pole tab includes a first connecting part and a second connecting part connected to each other. The first connecting part is connected to the first electrode plate, and the second connecting part extends out of the cell. The side of the second connecting part opposite to the first connecting part is connected to the pole post.

[0022] Optionally, the electrode post includes a first post and a second post, the first post and the second post are connected, the first post is located on the side of the cover plate body away from the battery cell, the second post is located on the side of the cover plate body facing the battery cell, the side of the second connection portion away from the first connection portion is connected to the side of the second post facing the battery cell, the area of ​​the first post projected onto the cover plate body is A, the area of ​​the second post projected onto the cover plate body is B, where B > A.

[0023] The beneficial effects of this utility model are:

[0024] The battery cell provided by this utility model has at least two first tabs on the first electrode plate and at least two second tabs on the second electrode plate. The first electrode plate and the second electrode plate are stacked and wound to form a rolled battery cell, thereby forming a battery cell with at least two first tabs and at least two second tabs. When the battery cell is charged and discharged, it can improve the uniformity of the current distribution on the battery cell, which is beneficial to the high-rate discharge and fast charging of the battery cell.

[0025] On the other hand, along the axial direction of the cell, at least two first tabs and at least two second tabs are located on the same side of the cell, so only one side of the battery cell's casing needs to be reserved to accommodate the tabs. This structure improves the utilization rate of the internal space of the casing and is conducive to improving the volumetric energy density of the battery cell. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the structure of the first electrode provided in Embodiment 1 of this utility model;

[0027] Figure 2 This is a schematic diagram of the structure of the second electrode provided in Embodiment 1 of this utility model;

[0028] Figure 3 This is a schematic diagram of the first structure of the battery cell provided in Embodiment 1 of this utility model;

[0029] Figure 4 This is a schematic diagram of the second structure of the battery cell provided in Embodiment 1 of this utility model;

[0030] Figure 5 This is a schematic diagram of the structure of a battery cell provided in Embodiment 1 of this utility model;

[0031] Figure 6 This is a schematic diagram of the cover plate assembly provided in Embodiment 1 of this utility model;

[0032] Figure 7 This is a schematic diagram of the shell structure provided in Embodiment 1 of this utility model;

[0033] Figure 8 This is a schematic diagram of the assembly structure of the second electrode tab and the housing provided in Embodiment 1 of this utility model;

[0034] Figure 9 This is a schematic diagram of the assembly structure of the first electrode tab and the electrode post provided in Embodiment 1 of this utility model;

[0035] Figure 10 This is a schematic diagram of the assembly structure of the second electrode tab and the housing provided in Embodiment 2 of this utility model;

[0036] Figure 11 This is a schematic diagram of the assembly structure of the first electrode tab and the electrode post provided in Embodiment 2 of this utility model;

[0037] Figure 12 This is a schematic diagram of the assembly structure of the second electrode tab and the housing provided in Embodiment 3 of this utility model;

[0038] Figure 13 This is a schematic diagram of the assembly structure of the first electrode tab and the electrode post provided in Embodiment 3 of this utility model;

[0039] Figure 14 This is a schematic diagram of the assembly structure of the second electrode tab and the housing provided in Embodiment 4 of this utility model;

[0040] Figure 15 This is a schematic diagram of the assembly structure of the first electrode tab and the electrode post provided in Embodiment 4 of this utility model.

[0041] In the picture:

[0042] 100, First electrode; 110, First current collector; 120, First active material layer; 121, First notch region; 200, First tab; 210, First middle tab; 221, First connecting part; 222, Second connecting part; 2221, Welding position; 300, Second electrode; 310, Second current collector; 320, Second active material layer; 321, Second notch region; 400, Second tab; 410, Second middle tab; 421, Third connecting part 422. Fourth connecting part; 423. Fixing area; 500. Housing; 510. Opening mouth; 520. Flared part; 600. Cover plate assembly; 610. Cover plate body; 611. First bending part; 612. First pressing part; 613. Second bending part; 614. Second pressing part; 620. Terminal post; 621. First post; 622. Second post; 623. Third post; 630. Insulating adhesive layer; 700. Battery cell; 710. Through hole. Detailed Implementation

[0043] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0044] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0046] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0047] Example 1

[0048] This embodiment provides a battery cell, which is mainly used in button-type batteries or cylindrical batteries. The battery cell structure can improve the uniformity of current distribution on the battery cell and also improve the utilization rate of the internal space of the battery cell casing.

[0049] Specifically, such as Figures 1 to 4As shown, the battery cell 700 is in a coil shape. The battery cell 700 includes a first electrode 100 and a second electrode 300. The first electrode 100 is provided with at least two first tabs 200, and the second electrode 300 is provided with at least two second tabs 400. The first electrode 100 and the second electrode 300 are stacked and wound to form the battery cell 700. Along the axial direction of the battery cell 700, at least two first tabs 200 and at least two second tabs 400 are located on the same side of the battery cell 700.

[0050] Based on the above design, the first electrode 100 is provided with at least two first tabs 200, and the second electrode 300 is provided with at least two second tabs 400. The first electrode 100 and the second electrode 300 are stacked and wound to form a rolled battery cell 700, thereby forming a battery cell 700 with at least two first tabs 200 and at least two second tabs 400. When the battery cell 700 is charged and discharged, it can improve the uniformity of the current distribution on the battery cell 700, which is beneficial to the high-rate discharge and fast charging of the battery cell 700.

[0051] On the other hand, along the axial direction of the cell 700, at least two first tabs 200 and at least two second tabs 400 are located on the same side of the cell 700, so only one side of the housing 500 of the battery cell needs to be reserved to accommodate the tabs. This structure improves the utilization rate of the internal space of the housing 500 and is conducive to improving the volumetric energy density of the battery cell.

[0052] In this embodiment, there are five first electrodes 200 and five second electrodes 400. In other embodiments, the number of first electrodes 200 and two electrodes 400 may be two, three, or six, etc.

[0053] In this embodiment, the first electrode 100 is a positive electrode, the first tab 200 is a positive tab, the second electrode 300 is a negative electrode, and the second tab 400 is a negative tab. Of course, in other embodiments, the first electrode 100 can be a negative electrode, the first tab 200 a negative tab, the second electrode 300 a positive electrode, and the second tab 400 a positive tab.

[0054] Furthermore, along the direction in which the first electrode 100 is wound (usually the length direction of the first electrode 100, i.e.) Figure 1 In the x1 or x2 direction, at least two first tabs 200 are evenly distributed on the first electrode plate 100, thus the tab connection positions on the first electrode plate 100 are relatively evenly distributed, along the winding direction of the second electrode plate 300 (usually the length direction of the second electrode plate 300, i.e. Figure 2In the x1 or x2 direction, at least two second tabs 400 are evenly distributed on the second electrode 300, and the tab connection positions on the second electrode 300 are more evenly distributed. This structure improves the uniformity of the distribution of multiple first tabs 200 and multiple second tabs 400 on the cell 700, thereby reducing the impedance of the cell 700, further improving the uniformity of the current distribution on the cell 700 during charging and discharging, and improving the rate performance of the cell 700.

[0055] Furthermore, along the winding direction of the first electrode 100, the first electrode tab 200 located at the non-end of the first electrode 100 is a first middle electrode tab 210. The number of first middle electrode tabs 210 is at least one; for example, the number of first middle electrode tabs 210 can be one, two, three, or four, etc. The first electrode 100 includes a first current collector 110 and a first active material layer 120 disposed on the first current collector 110. The first active material layer 120 is provided with first notch regions 121, and the number of first notch regions 121 is the same as the number of first middle electrode tabs 210. Each first middle electrode tab 210 is respectively connected via a corresponding... A first notch region 121 is disposed on the first current collector 110. By simply removing a corresponding area of ​​the first active material layer 120 to form a number of first notch regions 121 on the first active material layer 120 equal to the number of first central tabs 210, each first central tab 210 can be fixed to the first current collector 110 through a corresponding first notch region 121. This structure achieves connection between the first central tabs 210 and the first current collector 110, while preserving as much of the load on the first active material layer 120 as possible, thereby improving the energy density of the battery cell 700. In this embodiment, the first electrode 100 is a positive electrode, the first current collector 110 is an aluminum foil, and the first active material layer 120 is a positive active material layer.

[0056] Along the winding direction of the second electrode 300, the second electrode tab 400 located at the non-end end of the second electrode 300 is a second middle electrode tab 410. The number of second middle electrode tabs 410 is at least one; for example, the number of second middle electrode tabs 410 can be one, two, three, or four, etc. The second electrode 300 includes a second current collector 310 and a second active material layer 320 disposed on the second current collector 310. The second active material layer 320 is provided with second notch regions 321. The number of second notch regions 321 is the same as the number of second middle electrode tabs 410. Each second middle electrode tab 410 is connected to a corresponding one The second notch region 321 is disposed on the second current collector 310. By simply removing the corresponding area of ​​the second active material layer 320 to form a second notch region 321 on the second active material layer 320 equal in number to the second central electrode tabs 410, each second central electrode tab 410 can be fixed to the second current collector 310 through a corresponding second notch region 321. This structure achieves the connection between the second central electrode tabs 410 and the second current collector 310, while also preserving as much of the load of the second active material layer 320 on the second current collector 310 as possible, thereby improving the energy density of the battery cell 700. In this embodiment, the second electrode 300 is a negative electrode, the second current collector 310 is a copper foil, and the second active material layer 320 is a negative active material layer.

[0057] It should be noted that the non-end of the first electrode 100 mentioned above refers to the non-winding start section and the non-winding end section of the first electrode 100; the non-end of the second electrode 300 mentioned above refers to the non-winding start section and the non-winding end section of the second electrode 300. Typically, the winding start section and winding end section of the current collector do not have an active material layer. Therefore, if it is necessary to provide tabs in the winding start section and winding end section of the current collector, the tabs can be directly fixed to the winding start section and winding end section.

[0058] In this embodiment, there are five first tabs 200. The five first tabs 200 are evenly distributed along the winding direction of the first electrode 100. Three of the five first tabs 200 are first middle tabs 210, and the other two are welded and fixed to the winding start section and winding end section of the first electrode 100, respectively. The three first middle tabs 210 correspond one-to-one with the three first notch areas 121. Each first middle tab 210 is welded and fixed to the first current collector 110 through a corresponding first notch area 121. Along the winding direction of the first electrode 100, the three first middle tabs 210 are approximately located at 1 / 5, 1 / 2, and 4 / 5 of the first electrode 100, thereby forming a structure in which the five first tabs 200 are evenly distributed along the winding direction of the first electrode 100. There are five second tabs 400, which are evenly distributed along the winding direction of the second electrode 300. Three of the five second tabs 400 are second middle tabs 410, and the other two are welded and fixed to the winding start section and winding end section of the second electrode 300, respectively. The three second middle tabs 410 correspond one-to-one with the three second notch areas 321. Each second middle tab 410 is welded and fixed to the second current collector 310 through a corresponding second notch area 321. Along the winding direction of the second electrode 300, the three second middle tabs 410 are approximately located at 1 / 5, 1 / 2 and 4 / 5 of the second electrode 300, thus forming a structure in which the five second tabs 400 are evenly distributed along the winding direction of the second electrode 300.

[0059] In actual production, a portion of the first active material layer 120 can be laser-cleaned using an appropriate power based on the material and thickness of the first active material layer 120 to form a first notch area 121. Similarly, a portion of the second active material layer 320 can be laser-cleaned using an appropriate power based on the material and thickness of the second active material layer 320 to form a second notch area 321. The aforementioned power is typically 50W-500W.

[0060] Optionally, the first tab 200 includes a first connecting portion 221 and a second connecting portion 222 connected together. The first connecting portion 221 is connected to the first electrode 100. The second connecting portion 222 extends from the end of the cell 700 and is bent in the direction toward the axis of the cell 700, so that the second connecting portion 222 can be connected to the conductive components of the battery cell (terminal 620, cover plate body 610, or housing 500, etc.). The second tab 400 includes a third connecting portion 421 and a fourth connecting portion 422 connected together. The third connecting portion 421... Connected to the second electrode 300, the fourth connecting part 422 extends out of the end of the cell 700 and bends in a direction away from the axis of the cell 700 so that the fourth connecting part 422 can be connected to the conductive parts of the battery cell (terminal 620, cover plate body 610 or housing 500, etc.). Along the radial direction of the cell 700, any first electrode 200 and any second electrode 400 do not overlap, so as to achieve mutual avoidance between the first electrode 200 and the second electrode 400 and avoid mutual interference when bending the first electrode 200 and the second electrode 400.

[0061] This embodiment also provides a single battery cell, such as Figure 5 As shown, the battery cell includes a housing 500, a cover assembly 600, and the aforementioned battery cell 700. The housing 500 has an opening 510, and the battery cell 700 is disposed within the opening 510. The cover assembly 600 includes a cover body 610, which seals the opening of the opening 510. The battery cell uses the aforementioned battery cell 700, which exhibits high uniformity of current distribution and high volumetric energy density. In this embodiment, both the housing 500 and the cover body 610 are made of steel. In other embodiments, the housing 500 and the cover body 610 may also be made of aluminum or other materials.

[0062] Furthermore, both the first tab 200 and the second tab 400 extend from the side of the cell 700 facing the cover plate body 610, so that the first tab 200 and the second tab 400 can be connected to the pole post 620, the cover plate body 610 or the housing 500 and other components.

[0063] Optionally, such as Figure 2 and Figure 5As shown, the second tab 400 includes a third connecting portion 421 and a fourth connecting portion 422 connected together. The third connecting portion 421 is connected to the second current collector 310 of the second electrode 300. The fourth connecting portion 422 extends out of the end of the battery cell 700 and is bent in a direction away from the axis of the battery cell 700. One end of the fourth connecting portion 422 away from the third connecting portion 421 is clamped between the inner wall of the cover plate body 610 and the opening 510 to achieve conductive connection between the second tab 400 and the housing 500 and the cover plate body 610. In actual production, the length of the fourth connecting portion 422 can be appropriately extended. After the battery cell 700 is installed into the housing 500 and the fourth connecting portion 422 is clamped between the inner wall of the cover plate body 610 and the opening 510, the part of the fourth connecting portion 422 extending out of the cover plate body 610 is cut off. Then, the cover plate body 610, the housing 500 and the fourth connecting portion 422 are welded and fixed by laser welding.

[0064] Optionally, such as Figures 5 to 7 As shown, the edge of the cover plate body 610 is provided with a first bending portion 611, a first pressing portion 612, a second bending portion 613, and a second pressing portion 614. The first bending portion 611 is bent at 90° in the direction toward the battery cell 700. The two ends of the first pressing portion 612 are respectively connected to one end of the first bending portion 611 and the second bending portion 613. The second bending portion 613 is bent at 180° in the direction away from the battery cell 700. The second pressing portion 614 is connected to the other end of the second bending portion 613. The first pressing portion 612 and the second pressing portion 614 are in close contact. The opening of the housing 500 (i.e., the opening of the oral cavity 510) is provided with a flared portion 520. The inner wall of the flared portion 520 cooperates with the side of the second pressing portion 614 away from the first pressing portion 612 to clamp the fourth connecting portion 422 of the second electrode 400, so as to improve the reliability and stability of clamping the fourth connecting portion 422. In actual production, the first bending part 611, the first pressing part 612, the second bending part 613, the second pressing part 614, and the flared part 520 can be manufactured by a capping molding process.

[0065] Optionally, such as Figures 5 to 8 As shown, the fourth connecting portion 422 sandwiched between the inner wall of the cover plate body 610 and the opening 510 is a fixing area 423. The fixing areas 423 of at least two second tabs 400 are evenly distributed along the circumference of the cover plate body 610, and the fixing areas 423 of at least two second tabs 400 are evenly distributed along the circumference of the flared portion 520. On the one hand, this can improve the uniformity of force on the cell 700 along the circumference of the cell 700, thereby improving the stability of the cell 700 inside the casing 500, improving the reliability of the battery cell, and enabling the battery cell to adapt to application scenarios such as impact, vibration, and drop. On the other hand, this structure can improve the sealing performance of the cover plate body 610 in sealing the opening 510, thereby improving the sealing performance of the battery cell.

[0066] Optionally, such as Figure 1 , Figure 5 and Figure 6 As shown, the cover plate assembly 600 also includes a pole post 620 and an insulating layer 630. The pole post 620 is sealed and insulated through the insulating layer 630 and passes through the cover plate body 610. The first tab 200 includes a first connecting part 221 and a second connecting part 222 connected to each other. The first connecting part 221 is connected to the first electrode 100. The second connecting part 222 extends out of the cell 700. The side of the second connecting part 222 away from the first connecting part 221 is connected to the pole post 620 to realize the conductive connection between the first tab 200 and the pole post 620.

[0067] Furthermore, such as Figure 5 and Figure 6 As shown, the electrode post 620 includes a first post 621, a second post 622, and a third post 623. The first post 621 is located on the side of the cover plate body 610 away from the battery cell 700, the second post 622 is located on the side of the cover plate body 610 facing the battery cell 700, and the third post 623 is sealed and insulated through the cover plate body 610 by an insulating adhesive layer 630. The first post 621 is connected to the second post 622 through the third post 623. The second connecting part 222 is connected to the side of the second post 622 facing the battery cell 700 on the side away from the first connecting part 221. The area of ​​the first post 621 projected onto the cover plate body 610 is A, and the area of ​​the second post 622 projected onto the cover plate body 610 is B, where B > A, so that the second post 622 has a sufficiently large area to connect with the second connecting part 222.

[0068] In this embodiment, the second connecting part 222 extends out of the end of the cell 700 and bends toward the axis of the cell 700. The side of the second connecting part 222 away from the first connecting part 221 is connected to the side of the second column 622 toward the cell 700. Figure 9 A schematic diagram of the structure of the first tab 200 and the second post 622 is shown. The side of the second connecting portion 222 facing away from the first connecting portion 221 is the welding position 2221. The second connecting portion 222 and the second post 622 are welded at this welding position 2221. Of course, in other embodiments, when B is large enough, the second connecting portion 222 does not need to be bent, and the second connecting portion 222 extending from the end of the cell 700 can be directly connected to the side of the second post 622 facing the cell 700.

[0069] Optionally, such as Figures 3 to 5As shown, a through hole 710 is provided in the middle of the coiled battery cell 700. The through hole 710 is coaxial with the battery cell 700. In actual production, the welding needle can pass through the through hole 710 from the bottom of the battery cell 700 to the top of the battery cell 700, and resistance welding is performed on the side of the second connecting part 222 away from the first connecting part 221 and the side of the second column 622 facing the battery cell 700.

[0070] Example 2

[0071] This embodiment provides a single battery cell. The following mainly describes the differences between this embodiment and Embodiment 1, while the similarities will not be repeated.

[0072] like Figure 10 and Figure 11 As shown, the battery cell 700 includes four first tabs 200 and four second tabs 400. The four first tabs 200 are evenly distributed on the first electrode 100 along the winding direction of the first electrode 100, and the four second tabs 400 are evenly distributed on the second electrode 300 along the winding direction of the second electrode 300. The fixing area 423 of the four second tabs 400 is evenly distributed along the circumference of the cover body 610, that is, the fixing area 423 of the four second tabs 400 is evenly distributed along the circumference of the flared portion 520.

[0073] Example 3

[0074] This embodiment provides a single battery cell. The following mainly describes the differences between this embodiment and Embodiment 1, while the similarities will not be repeated.

[0075] like Figure 12 and Figure 13 As shown, the battery cell 700 includes three first tabs 200 and three second tabs 400. The three first tabs 200 are evenly distributed on the first electrode 100 along the winding direction of the first electrode 100, and the three second tabs 400 are evenly distributed on the second electrode 300 along the winding direction of the second electrode 300. The fixing area 423 of the three second tabs 400 is evenly distributed along the circumference of the cover body 610, that is, the fixing area 423 of the three second tabs 400 is evenly distributed along the circumference of the flared portion 520.

[0076] In this embodiment, there are three first tabs 200 and three second tabs 400. At this time, there is one first middle tab 210, one first notch area 121, one second middle tab 410 and one second notch area 321. Specifically, two of the three first tabs 200 are located at the starting and ending sections of the winding of the first current collector 110, respectively, and the remaining first tab 200 is the first middle tab 210. A first notch area 121 is provided on the first active material layer 120. The aforementioned first middle tab 210 is welded and fixed to the first current collector 110 through the first notch area 121, thereby forming a structure in which the three first tabs 200 are evenly distributed along the winding direction of the first electrode 100. Two of the three second tabs 400 are located at the beginning and end of the winding of the second current collector 310, respectively, and the remaining second tab 400 is the second middle tab 410. A second notch region 321 is provided on the second active material layer 320. The aforementioned second middle tab 410 is welded and fixed to the second current collector 310 through the second notch region 321, thereby forming a structure in which the three second tabs 400 are evenly distributed along the winding direction of the second electrode 300.

[0077] Example 4

[0078] This embodiment provides a single battery cell. The following mainly describes the differences between this embodiment and Embodiment 1, while the similarities will not be repeated.

[0079] like Figure 14 and Figure 15 As shown, the battery cell 700 includes two first tabs 200 and two second tabs 400. The two first tabs 200 are evenly distributed on the first electrode 100 along the winding direction of the first electrode 100, and the two second tabs 400 are evenly distributed on the second electrode 300 along the winding direction of the second electrode 300. The fixing area 423 of the two second tabs 400 is evenly distributed along the circumference of the cover body 610, that is, the fixing area 423 of the two second tabs 400 is evenly distributed along the circumference of the flared portion 520.

[0080] In this embodiment, there are two first tabs 200 and two second tabs 400. At this time, there are also two first middle tabs 210, two first notch regions 121, two second middle tabs 410, and two second notch regions 321. Specifically, both first tabs 200 are first middle tabs 210. The first active material layer 120 has two first notch regions 121. The two first middle tabs 210 are respectively welded and fixed to the first current collector 110 through a corresponding first notch region 121, thereby forming a structure in which the two first tabs 200 are evenly distributed along the winding direction of the first electrode 100. Similarly, both second tabs 400 are second middle tabs 410. The second active material layer 320 has two second notch regions 321. The two second middle tabs 410 are respectively welded and fixed to the second current collector 310 through a corresponding second notch region 321, thereby forming a structure in which the two second tabs 400 are evenly distributed along the winding direction of the second electrode 300.

[0081] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A battery cell, characterized in that, The battery cell is in a coil shape, and the battery cell includes: A first electrode plate (100) is provided with at least two first electrode tabs (200); The second electrode (300) has at least two second tabs (400). The first electrode (100) and the second electrode (300) are stacked and wound together to form the battery cell (700). Along the axial direction of the battery cell (700), at least two first tabs (200) and at least two second tabs (400) are located on the same side of the battery cell (700).

2. The battery cell according to claim 1, characterized in that, Along the winding direction of the first electrode (100), at least two first electrode tabs (200) are evenly distributed on the first electrode (100), and along the winding direction of the second electrode (300), at least two second electrode tabs (400) are evenly distributed on the second electrode (300).

3. The battery cell according to claim 2, characterized in that, Along the winding direction of the first electrode (100), the first tab (200) located at the non-end of the first electrode (100) is a first middle tab (210). The number of the first middle tabs (210) is at least one. The first electrode (100) includes a first current collector (110) and a first active material layer (120) disposed on the first current collector (110). The first active material layer (120) is provided with a first notch region (121). The number of the first notch regions (121) is the same as the number of the first middle tabs (210). Each first middle tab (210) is disposed on the first current collector (110) through a corresponding first notch region (121). Along the winding direction of the second electrode (300), the second electrode tab (400) located at the non-end of the second electrode (300) is a second middle electrode tab (410). The number of the second middle electrode tabs (410) is at least one. The second electrode (300) includes a second current collector (310) and a second active material layer (320) disposed on the second current collector (310). The second active material layer (320) is provided with a second notch region (321). The number of the second notch regions (321) is the same as the number of the second middle electrode tabs (410). Each second middle electrode tab (410) is disposed on the second current collector (310) through a corresponding second notch region (321).

4. The battery cell according to any one of claims 1-3, characterized in that, Along the radial direction of the battery cell (700), any of the first tabs (200) and any of the second tabs (400) do not overlap. The first tab (200) includes a first connecting portion (221) and a second connecting portion (222) connected together. The first connecting portion (221) is connected to the first electrode (100). The second connecting portion (222) extends out of the end of the battery cell (700) and is bent in a direction toward the axis of the battery cell (700). The second tab (400) includes a third connecting portion (421) and a fourth connecting portion (422) connected together. The third connecting portion (421) is connected to the second electrode (300). The fourth connecting portion (422) extends out of the end of the battery cell (700) and is bent in a direction away from the axis of the battery cell (700).

5. A single battery cell, characterized in that, The device includes a housing (500), a cover assembly (600), and a battery cell (700) as described in any one of claims 1-4. The housing (500) has an opening (510), and the battery cell (700) is disposed within the opening (510). The cover assembly (600) includes a cover body (610), which is sealed at the opening of the opening (510).

6. The battery cell according to claim 5, characterized in that, Both the first tab (200) and the second tab (400) extend from the side of the cell (700) facing the cover plate body (610).

7. The battery cell according to claim 6, characterized in that, The second electrode tab (400) includes a third connecting part (421) and a fourth connecting part (422) connected to each other. The third connecting part (421) is connected to the second electrode plate (300). The fourth connecting part (422) extends out of the end of the cell (700) and bends in a direction away from the axis of the cell (700). The end of the fourth connecting part (422) away from the third connecting part (421) is clamped between the cover plate body (610) and the inner wall of the opening (510).

8. The battery cell according to claim 7, characterized in that, The fourth connecting portion (422) sandwiched between the inner wall of the cover plate body (610) and the opening (510) is a fixing area (423), and the fixing areas (423) of at least two second pole ears (400) are evenly distributed along the circumference of the cover plate body (610).

9. The battery cell according to any one of claims 6-8, characterized in that, The cover plate assembly (600) further includes a pole post (620), which is sealed and insulated through the cover plate body (610). The first electrode tab (200) includes a first connecting part (221) and a second connecting part (222) connected to each other. The first connecting part (221) is connected to the first electrode plate (100), and the second connecting part (222) extends out of the cell (700). The side of the second connecting part (222) opposite to the first connecting part (221) is connected to the pole post (620).

10. The battery cell according to claim 9, characterized in that, The electrode post (620) includes a first post (621) and a second post (622). The first post (621) is connected to the second post (622). The first post (621) is located on the side of the cover plate body (610) away from the battery cell (700). The second post (622) is located on the side of the cover plate body (610) facing the battery cell (700). The second connecting part (222) is connected to the side of the second post (622) facing the battery cell (700) on the side away from the first connecting part (221). The area of ​​the first post (621) projected onto the cover plate body (610) is A, and the area of ​​the second post (622) projected onto the cover plate body (610) is B, where B > A.

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