Pole piece, battery cell and battery

Abstract

The utility model relates to a battery technical field especially relates to a kind of pole piece, battery cell and battery.The utility model provides pole piece including pole piece main part and tab, wherein, tab includes top edge, bottom edge and two arc edges, the length size of top edge is less than the length size of bottom edge, bottom edge is connected with pole piece main part, two arc edges are oppositely arranged along the width direction of tab, one end of top edge and one end of bottom edge are connected by one of arc edges, the other end of top edge and the other end of bottom edge are connected by another arc edge.The utility model provides pole piece, effectively increases the area of tab, reduces current density, weakens overcurrent heating, meets the charge-discharge demand of large current, and by arc edge connecting the top edge and bottom edge of tab, stress received by tab can be better dispersed, the fatigue resistance of tab is enhanced, and the risk of tab fracture is avoided.

Description

Technical Field

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

[0002] In related technologies, the tabs on the electrode sheet are rectangular, and to facilitate connection between the tab and the connecting piece, the width of the tab needs to match the width of the connecting piece. To facilitate the production of the connecting piece and reduce its cost, the connecting piece is typically narrow, resulting in a narrower tab, significantly reducing the tab's area and making it unsuitable for meeting high-current charging and discharging requirements. Furthermore, existing tabs experience concentrated stress, making them prone to fatigue fracture under high-frequency vibration and impact.

[0003] Therefore, there is an urgent need for an electrode, cell, and battery to solve the above problems. Utility Model Content

[0004] The purpose of this invention is to provide an electrode, a cell, and a battery that increases the area of ​​the tab, reduces the current density, weakens overcurrent heating, meets the charging and discharging requirements of high current, enhances the fatigue resistance of the tab, and avoids the risk of tab breakage.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] An electrode sheet comprising:

[0007] Electrode body;

[0008] The electrode tab includes a top edge, a bottom edge, and two arc edges. The length of the top edge is smaller than the length of the bottom edge. The bottom edge is connected to the electrode body. The two arc edges are arranged opposite each other along the width direction of the electrode tab. One end of the top edge and one end of the bottom edge are connected through one of the arc edges, and the other end of the top edge and the other end of the bottom edge are connected through the other arc edge.

[0009] Alternatively, each of the arc edges protrudes in a direction away from the other arc edge.

[0010] As an optional solution, if the arc angle of the arc edge is θ1, then 0° < θ1 < 90°.

[0011] As an optional solution, the height dimension of the electrode tab is H, and the distance from the first end of the arc edge to the second end of the arc edge along the width direction of the electrode tab is L1, then L1 > H.

[0012] As an optional solution, the angle between the line segment between the first end and the second end of the arc edge and the bottom edge is θ2, then 0° < θ2 < 45°.

[0013] As an optional solution, the width dimension of the electrode body is B, and the distance from the first end of the arc edge to the second end of the arc edge along the width direction of the electrode tab is L1, then 0 < L1 / B < 0.5.

[0014] As an optional solution, the distance between the end of the bottom edge and the end of the electrode body is L2, then L2≥0.

[0015] As an optional solution, the surface of the end of the electrode tab that is connected to the electrode body is provided with a reinforcing coating.

[0016] A battery cell includes a separator, a positive electrode, and a negative electrode, wherein the separator is disposed between the positive electrode and the negative electrode, and at least one of the positive electrode and the negative electrode is an electrode as described above.

[0017] A battery includes a housing and a cell as described above, the cell being housed within the housing.

[0018] The beneficial effects of this utility model are:

[0019] This invention provides an electrode sheet comprising an electrode sheet body and an electrode tab. The electrode tab includes a top edge, a bottom edge, and two arc-shaped edges. The length of the top edge is less than the length of the bottom edge. The bottom edge is connected to the electrode sheet body. The two arc-shaped edges are arranged opposite each other along the width direction of the electrode tab. One end of the top edge and one end of the bottom edge are connected by one of the arc-shaped edges, and the other end of the top edge and the other end of the bottom edge are connected by the other arc-shaped edge. By making the length of the top edge of the electrode tab less than the length of the bottom edge, this invention ensures that the length of the top edge is consistent with the width of the connecting piece, facilitating the connection between the top edge and the connecting piece. Furthermore, by connecting the top and bottom edges of the electrode tab with arc-shaped edges, the width of the electrode tab gradually increases from the top edge to the bottom edge, effectively increasing the area of ​​the electrode tab, reducing the current density, mitigating overcurrent heating, and meeting the requirements of high-current charging and discharging. Furthermore, by connecting the top and bottom edges of the tab with a circular arc edge, the stress on the tab can be distributed across the entire circular arc edge, thereby better dispersing the stress on the tab, enhancing the fatigue resistance of the tab, and avoiding the risk of tab breakage.

[0020] This utility model also provides a battery cell that, by applying the aforementioned electrode plates, meets the high-current charging and discharging requirements of the battery cell, avoids the risk of electrode breakage, and improves the reliability of the battery cell.

[0021] This utility model also provides a battery that, by using the aforementioned battery cell, meets the high-current charging and discharging requirements of the battery, avoids the risk of tab breakage, and improves the reliability of the battery. Attached Figure Description

[0022] Figure 1 This is a first structural schematic diagram of the electrode sheet provided in this embodiment of the utility model;

[0023] Figure 2 This is a schematic diagram of the second structure of the electrode sheet provided in this embodiment of the utility model;

[0024] Figure 3 This is a schematic diagram of the third structure of the electrode sheet provided in this embodiment of the utility model.

[0025] In the picture:

[0026] 1. Electrode body; 2. Electrode tab; 21. Top edge; 22. Bottom edge; 23. Rounded edge. Detailed Implementation

[0027] To make the technical problem solved by this utility model, the technical solution adopted, and the technical effect achieved clearer, the technical solution of this utility model will be further described below with reference to the accompanying drawings and specific embodiments.

[0028] 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.

[0029] 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.

[0030] In the description of this embodiment, the terms "upper," "lower," "left," and "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.

[0031] In related technologies, the tabs on the electrode sheet are rectangular, and to facilitate connection between the tab and the connecting piece, the width of the tab needs to match the width of the connecting piece. To facilitate the production of the connecting piece and reduce its cost, the connecting piece is usually narrow, resulting in a narrower tab, significantly reducing the tab area and making it unsuitable for high-current charging and discharging. Furthermore, the rectangular shape of the tab leads to concentrated stress, increasing the risk of fatigue fracture under high-frequency vibration and impact, especially since the root of the tab connecting to the electrode body is at a right angle, making it more prone to fracture at the root.

[0032] To solve the above problems, such as Figures 1-3 As shown, this embodiment provides an electrode sheet, which includes an electrode sheet body 1 and an electrode tab 2. The electrode tab 2 includes a top edge 21, a bottom edge 22 and two arc edges 23. The length of the top edge 21 is smaller than the length of the bottom edge 22. The bottom edge 22 is connected to the electrode sheet body 1. The two arc edges 23 are arranged opposite each other along the width direction of the electrode tab 2. One end of the top edge 21 and one end of the bottom edge 22 are connected through one of the arc edges 23, and the other end of the top edge 21 and the other end of the bottom edge 22 are connected through the other arc edge 23. The electrode provided in this embodiment ensures that the length of the top edge 21 of the tab 2 is smaller than the length of the bottom edge 22, thus matching the width of the connecting piece. This facilitates the connection between the top edge 21 and the connecting piece. Furthermore, the arc edge 23 connects the top edge 21 and the bottom edge 22 of the tab 2, causing the width of the tab 2 to gradually increase from the top edge 21 to the bottom edge 22. This effectively increases the area of ​​the tab 2, reduces the current density, weakens overcurrent heating, and meets the requirements of high-current charging and discharging. Moreover, the arc edge 23 disperses the stress on the tab 2 across the entire arc edge 23, thereby better dispersing the stress on the tab 2, enhancing its fatigue resistance, and preventing the risk of breakage.

[0033] Optionally, in this embodiment, the top edge 21 and the bottom edge 22 are arranged opposite to each other and spaced apart, and the top edge 21 and the bottom edge 22 are arranged parallel to each other.

[0034] Optionally, in this embodiment, as Figure 1As shown, each arc edge 23 protrudes away from the other arc edge 23. This arrangement makes both arc edges 23 outwardly convex, further increasing the area of ​​the tab 2, reducing the current density, and ensuring that the charging and discharging requirements of high current are met. Furthermore, during charging and discharging, the root of the tab 2 connected to the electrode body 1 expands and contracts. The outwardly convex arc edge 23, compared to the rectangular tab 2 and the concave arc, can better disperse the stress generated by the expansion and contraction of the tab 2, preventing the active material on the tab 2 from cracking, falling off, or developing cracks, thus ensuring the safety performance of the battery cell. Moreover, when the tab 2 is subjected to external force, the outwardly convex arc edge 23 experiences tensile force, while the concave arc experiences compressive force. The fatigue strength of the electrode in the tensile state is better than that in the compressive state, thereby improving the overall fatigue resistance of the tab 2. Furthermore, under the condition of the same width of tab 2, the outwardly convex arc edge 23 can reduce the foil weight of tab 2 and increase the energy density of the cell.

[0035] Optionally, in this embodiment, as Figure 2 As shown, the arc angle of the arc edge 23 is θ1, then 0° < θ1 < 90°. Specifically, the arc angle θ1 of the arc edge 23 can be 1°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, or 85°. The above numerical limitation ensures the curvature of the arc edge 23, thereby better dispersing the stress on the electrode tab 2, and also ensures the length dimension of the top edge 21, facilitating the connection between the electrode tab 2 and the connecting piece.

[0036] Optionally, in this embodiment, as Figure 3 As shown, the height of the tab 2 is H (i.e., the distance between the top edge 21 and the bottom edge 22). Along the width direction of the tab 2, the distance from the first end to the second end of the arc edge 23 is L1, where L1 > H. This arrangement ensures that the center of the arc edge 23 is located on the electrode body 1, guaranteeing not only the curvature of the arc edge 23 but also the length of the top edge 21.

[0037] Optionally, in this embodiment, as Figure 3As shown, the angle between the line segment connecting the first and second ends of the arc edge 23 and the bottom edge 22 is θ2, where 0° < θ2 < 45°. Specifically, the angle θ2 between the line segment connecting the first and second ends of the arc edge 23 and the bottom edge 22 can be 1°, 5°, 10°, 15°, 20°, 25°, 30°, 35°, or 40°. These numerical limitations ensure the curvature of the arc edge 23, thereby better dispersing the stress on the tab 2, and also ensuring the length of the top edge 21, facilitating the connection between the tab 2 and the connecting piece.

[0038] Optionally, such as Figure 3 As shown, in this embodiment, the width of the electrode body 1 is B, and the distance from the first end to the second end of the arc edge 23 along the width direction of the electrode tab 2 is L1, then 0 < L1 / B < 0.5. Specifically, L1 / B can be 0.1, 0.2, 0.3, 0.4, or 0.45. The above numerical limitation ensures the curvature of the arc edge 23, thereby better dispersing the stress on the electrode tab 2, and also ensures the length of the top edge 21, facilitating the connection between the electrode tab 2 and the connecting piece.

[0039] Optionally, such as Figure 3 As shown, the distance between the end of the bottom edge 22 and the end of the electrode body 1 is L2, so L2≥0. The above setting can make L2=0, thereby further increasing the area of ​​the electrode tab 2, or it can make there a distance between the end of the bottom edge 22 and the end of the electrode body 1. The specific setting can be set according to the requirements.

[0040] Optionally, a reinforcing coating is provided on the surface of the end of the tab 2 that connects to the electrode body 1. This further improves the structural strength of the root of the connection between the tab 2 and the electrode body 1, preventing breakage at the connection point. Optionally, the reinforcing coating can be an adhesive layer.

[0041] This embodiment also provides a battery cell, which includes a separator, a positive electrode, and a negative electrode. The separator is disposed between the positive and negative electrode, and at least one of the positive and negative electrode is the aforementioned electrode. By using the aforementioned electrode, the battery cell provided in this embodiment meets the high-current charging and discharging requirements of the battery cell and avoids the risk of electrode tab 2 breakage, thus improving the reliability of the battery cell.

[0042] It should be noted that in this embodiment, the battery cell can be a wound core or a stacked core, and this embodiment does not limit the specific form of the battery cell.

[0043] This embodiment also provides a battery, which includes a casing and the aforementioned battery cell, with the battery cell housed within the casing. By utilizing the aforementioned battery cell, the battery provided in this embodiment meets the high-current charging and discharging requirements of the battery and avoids the risk of tab 2 breakage, thus improving battery reliability.

[0044] 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 other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations 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. An electrode sheet, characterized in that, include: Electrode body (1); The electrode tab (2) includes a top edge (21), a bottom edge (22), and two arc edges (23). The length of the top edge (21) is smaller than that of the bottom edge (22). The bottom edge (22) is connected to the electrode body (1). The two arc edges (23) are arranged opposite to each other along the width direction of the electrode tab (2). One end of the top edge (21) and one end of the bottom edge (22) are connected through one of the arc edges (23), and the other end of the top edge (21) and the other end of the bottom edge (22) are connected through the other arc edge (23).

2. The electrode sheet according to claim 1, characterized in that, Each of the arc edges (23) protrudes in a direction away from the other arc edge (23).

3. The electrode sheet according to claim 1, characterized in that, The arc angle of the arc edge (23) is θ1, then 0° < θ1 < 90°.

4. The electrode sheet according to any one of claims 1 to 3, characterized in that, The height dimension of the tab (2) is H. Along the width direction of the tab (2), the distance from the first end of the arc edge (23) to the second end of the arc edge (23) is L1, then L1 > H.

5. The electrode sheet according to any one of claims 1 to 3, characterized in that, The angle between the line segment between the first end of the arc edge (23) and the second end of the arc edge (23) and the bottom edge (22) is θ2, then 0° < θ2 < 45°.

6. The electrode sheet according to any one of claims 1 to 3, characterized in that, The width dimension of the electrode body (1) is B. Along the width direction of the electrode tab (2), the distance from the first end of the arc edge (23) to the second end of the arc edge (23) is L1. Then 0 < L1 / B < 0.

5.

7. The electrode sheet according to any one of claims 1 to 3, characterized in that, If the distance between the end of the bottom edge (22) and the end of the electrode body (1) is L2, then L2≥0.

8. The electrode sheet according to any one of claims 1 to 3, characterized in that, The surface of the end of the tab (2) that is connected to the electrode body (1) is provided with a reinforcing coating.

9. A battery cell, characterized in that, It includes a separator, a positive electrode, and a negative electrode, wherein the separator is disposed between the positive electrode and the negative electrode, and at least one of the positive electrode and the negative electrode is the electrode as described in any one of claims 1 to 8.

10. A battery, characterized in that, It includes a housing and the battery cell as described in claim 9, wherein the battery cell is housed within the housing.

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