Cover plate, monomer battery cell and battery pack

Abstract

The utility model relates to battery technical field provides a cover plate, single battery and battery package. The cover plate constructs at least two thinning area interval setting along the circumference, and the score connected in every adjacent two thinning area. Therefore, can reduce the valve resistance of cover plate, promotes the valve stability of cover plate to improve the security of single battery.

Description

Technical Field

[0001] This utility model relates to the field of battery technology, specifically to a cover plate, a single battery cell, and a battery pack. Background Technology

[0002] In related technologies, the cover plate of a single battery cell typically has grooves as a safety feature. When a single battery cell experiences thermal runaway, the grooves break, opening the valve and releasing gas, ensuring safety. However, the grooves on the cover plate are usually circular, making it difficult to control the stability of the valve opening, reducing its reliability and impacting the safety of the single battery cell. Utility Model Content

[0003] The embodiments of this utility model provide a cover plate, a single battery cell, and a battery pack, which can reduce the valve opening resistance of the cover plate, improve the valve opening stability of the cover plate, and thus improve the safety of the single battery cell.

[0004] In a first aspect, embodiments of the present invention provide a cover plate having at least two circumferentially spaced thinning zones and grooves connecting each adjacent pair of thinning zones.

[0005] This reduces valve opening resistance, makes it easier to open the cover plate, increases valve opening stability, and thus improves the safety of individual battery cells.

[0006] In one embodiment, at least two of the thinning regions are located on a first circumference of the cover plate, and the diameter of the first circumference is D1; ​​at least two of the grooves are located on a second circumference of the cover plate, and the diameter of the second circumference is D2, satisfying: D2 < D1.

[0007] Therefore, when a certain pressure is reached, the thinning zone at the outer end tears first, which in turn causes the scoring to tear and open the valve.

[0008] In one embodiment, the groove includes an arc-shaped segment and a first connecting segment and a second connecting segment connecting the two ends of the arc-shaped segment. The arc-shaped segment and the cover plate share the same center. The first connecting segment is connected to one of the thinning areas, and the second connecting segment is connected to another thinning area.

[0009] Therefore, the thinning zone can sequentially drive the first connecting segment and the arc-shaped segment to tear, and / or sequentially drive the second connecting segment and the arc-shaped segment to tear.

[0010] In one embodiment, the diameter of the cover plate is D0, and the diameter of the arc segment is D2, satisfying: 30%D0≤D2≤85%D0.

[0011] This ensures that the gas and core ejection speeds during valve opening are met, guaranteeing safe valve opening.

[0012] In one embodiment, the thickness of the cover plate is T1, and the thickness of the thinning region is T2, satisfying: 0.16T1≤T1-T2≤0.8T1.

[0013] This ensures the stress concentration effect after the thinning zone and the groove are matched, and prevents premature pressure release or false triggering of pressure release due to an excessively small valve opening threshold.

[0014] In one embodiment, the width of the groove decreases along the direction from the opening of the groove to the bottom surface.

[0015] This helps increase the strength of the forming mold and reduce the resistance during stamping.

[0016] In one embodiment, the thickness of the cover plate is T1, and the width of the notch opening is B1, satisfying: 0.1T1≤B1≤2T1.

[0017] This ensures that the grooves can be formed and avoids excessive resistance during the groove-making process.

[0018] In one embodiment, the width of the bottom surface of the groove is B2, which satisfies: 0.1B1≤B2≤0.8B1.

[0019] This prevents the valve opening threshold of the cover plate from being too high or too low, ensuring the stability of valve opening.

[0020] In one embodiment, the thickness of the cover plate is T1, and the depth of the groove is H, satisfying: 0.3T1≤H≤0.95T1.

[0021] This prevents the valve opening threshold of the cover plate from being too high or too low, ensuring the stability of valve opening.

[0022] Secondly, embodiments of this utility model provide a single battery cell, including the cover plate as described above.

[0023] This reduces valve opening resistance, makes it easier to open the cover plate, increases valve opening stability, and thus improves the safety of individual battery cells.

[0024] Thirdly, embodiments of this utility model provide a battery pack, including the single battery cell as described above.

[0025] This reduces valve opening resistance, makes it easier to open the cover, increases valve opening stability, and thus improves battery pack safety.

[0026] The beneficial effects of the embodiments of this utility model are as follows:

[0027] In embodiments of this invention, by constructing a thinning zone on the cover plate and connecting the scoring to the thinning zone, the internal stress of the individual cell is concentrated in the thinning zone. The thinning zone fractures first, causing the scoring to tear and open the valve. This reduces valve opening resistance, makes it easier to open the cover plate, increases valve opening stability, and thus improves the safety of the individual cell. Attached Figure Description

[0028] To more clearly illustrate the technical solutions in the embodiments of this utility model, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0029] Figure 1 This is a schematic diagram of the structure of a single battery cell provided in an embodiment of this utility model;

[0030] Figure 2 This is a schematic diagram of the structure of the cover plate provided in an embodiment of this utility model;

[0031] Figure 3 This is one of the partial cross-sectional views of a single battery cell provided in an embodiment of this utility model;

[0032] Figure 4 This is a second partial cross-sectional view of a single battery cell provided in an embodiment of this utility model.

[0033] Explanation of reference numerals in the attached figures:

[0034] 1. Cover plate; 11. Thinning area; 111. Arc-shaped segment; 112. First connecting segment; 113. Second connecting segment; 12. Score;

[0035] 2. Individual battery cell. Detailed Implementation

[0036] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of the present utility model. In addition, it should be understood that the specific embodiments described herein are only for illustration and explanation of the present utility model and are not intended to limit the present utility model. In the present utility model, unless otherwise stated, directional terms such as "upper" and "lower" generally refer to the upper and lower positions of the device in actual use or operation, specifically the drawing directions in the accompanying drawings; while "inner" and "outer" refer to the outline of the device.

[0037] This application provides a battery pack. The battery pack includes a battery box and battery modules disposed within the battery box. The battery modules include multiple individual battery cells 2. The battery box provides a space for accommodating the individual battery cells 2, and the battery box can adopt various structures. In some embodiments, the battery box includes a casing and a top cover that overlap each other. The casing and the top cover together define an accommodating space for accommodating the individual battery cells 2. The casing can be a hollow structure, and the top cover can be a plate-like structure, with the top cover covering the opening side of the casing so that the top cover and the casing together define the accommodating space. Both the casing and the top cover can be hollow structures with an opening on one side, with the opening of the top cover covering the opening side of the casing. Of course, the battery box formed by the top cover and the casing can be of various shapes, such as a cylinder, a cuboid, etc.

[0038] In a battery pack, there can be multiple individual battery cells 2. These cells can be connected in series, parallel, or in a hybrid configuration. A hybrid configuration means that multiple individual battery cells 2 are connected in both series and parallel connections. Multiple individual battery cells 2 can be directly connected in series, parallel, or in a hybrid configuration, and then the entire assembly of these cells 2 is housed within a battery box. Alternatively, the battery pack can consist of multiple individual battery cells 2 first connected in series, parallel, or in a hybrid configuration to form battery modules, and then these battery modules are connected in series, parallel, or in a hybrid configuration to form a whole, which is then housed within a battery box. The battery pack can also include other structures; for example, it can include a busbar component for electrical connection between the multiple individual battery cells 2.

[0039] Each individual cell 2 can be a secondary battery or a primary battery; it can also be a lithium-sulfur battery, a sodium-ion battery, or a magnesium-ion battery, but is not limited to these. The individual cell 2 can be cylindrical, flat, cuboid, or other shapes.

[0040] This application also provides a single battery cell 2. The single battery cell 2 includes a housing, a cover plate 1, and electrode assemblies and other functional components located within the housing.

[0041] like Figures 1 to 4 As shown, this application embodiment also provides a cover plate 1. The cover plate 1 is constructed with at least two thinning regions 11 arranged circumferentially, and a groove 12 connecting each two adjacent thinning regions 11.

[0042] In this embodiment, by constructing a thinning region 11 on the cover plate 1 and connecting the groove 12 to the thinning region 11, the internal stress of the individual cell 2 is concentrated in the thinning region 11. The thinning region 11 breaks first, causing the groove 12 to tear and open the valve. This reduces the valve opening resistance, makes it easier to open the cover plate 1, increases the stability of valve opening, and thus improves the safety of the individual cell 2.

[0043] It is understandable that if the thickness of the thinning region 11 is less than the thickness of the cover plate 1, then the thinning region 11 is more easily torn than the cover plate 1 itself. In this embodiment, based on connecting the groove 12 with the thinning region 11, both the thinning region 11 and the groove 12 can make the stress more concentrated when there is pressure inside the single cell 2, thereby making it easier for the cover plate 1 to open.

[0044] In some embodiments, the shape of the thinning area 11 can be set to any shape such as circle, square, rhombus, or ellipse, ensuring that the thickness of the thinning area 11 is less than the thickness of the cover plate 1, and that the thinning area 11 is connected to the groove 12.

[0045] In some embodiments, the thinning region 11 can also improve the strength of the stamping die at the edge of the notch 12, thereby increasing the strength of the forming die and reducing the resistance during stamping.

[0046] In some embodiments, the number of thinning regions 11 can be set to eight, and the number of notches 12 can also be set to eight, which are interleaved and connected to form a closed structure.

[0047] In some embodiments, the number of thinning regions 11 can be set to any number such as 2, 3, 5, or 10. The position and number of thinning regions 11 can be reasonably set based on the shape and size of the thinning regions 11 and the shape and size of the cover plate 1. The number of grooves 12 is the same as the number of thinning regions 11.

[0048] In some embodiments, at least two thinning regions 11 are arranged in a centrally symmetrical manner on the surface of the cover plate 1. At least two notches 12 are also arranged in a centrally symmetrical manner.

[0049] like Figure 2 As shown, in some embodiments, at least two thinning regions 11 are located on the first circumference of the cover plate 1, and the diameter of the first circumference is D1; ​​at least two grooves 12 are located on the second circumference of the cover plate 1, and the diameter of the second circumference is D2, satisfying: D2 < D1.

[0050] Understandably, since the diameter of the first circumference is larger than the diameter of the second circumference, the thinning region 11 is located outside the notch 12. That is, the thinning region 11 can be regarded as an outwardly convex structure of the notch 12, so that the stress of the notch 12 is more concentrated when subjected to internal pressure. When a certain pressure is reached, the thinning region 11 located at the outer end tears first, and drives the notch 12 to tear open.

[0051] For example, the diameter D1 of the first circumference is set to 35 mm, and the diameter D2 of the second circumference is set to 30 mm.

[0052] like Figure 2As shown, in some embodiments, the notch 12 includes an arc segment 111 and a first connecting segment 112 and a second connecting segment 113 connected to both ends of the arc segment 111. The arc segment 111 is concentric with the cover plate 1. The first connecting segment 112 is connected to a thinning area 11, and the second connecting segment 113 is connected to another thinning area 11.

[0053] It is understandable that the notch 12 is configured as an arc-shaped segment 111 and a first connecting segment 112 and a second connecting segment 113 connecting both ends of the arc-shaped segment 111. When the thinning area 11 breaks, the thinning area 11 can sequentially tear the first connecting segment 112 and the arc-shaped segment 111, and / or sequentially tear the second connecting segment 113 and the arc-shaped segment 111. Since the thinning area 11 is located outside the notch 12, it is also located outside the arc-shaped segment 111. The first connecting segment 112 and the second connecting segment 113 are segments of the notch 12 extending radially outward along the cover plate 1.

[0054] In some embodiments, the arc segment 111 and the cover plate 1 are concentric. After all the arc segments 111 are torn open, the core can also be ejected from the opening after the valve is opened, ensuring the safety of the individual battery cell 2.

[0055] In some embodiments, the arc segment 111, the first connecting segment 112, and the second connecting segment 113 have the same groove depth. Alternatively, the arc segment 111, the first connecting segment 112, and the second connecting segment 113 have different groove depths.

[0056] Please continue reading. Figure 2 In some embodiments, the diameter of the cover plate 1 is D0, and the diameter of the arc segment 111 is D2, satisfying: 30%D0≤D2≤85%D0.

[0057] It is understandable that setting the diameter D2 of the arc segment 111 within the range of 30%D0 to 85%D0 can meet the requirements of gas and core ejection speed during valve opening while taking into account the size of the individual cell 2, thus ensuring safe valve opening.

[0058] For example, the diameter D2 of the arc segment 111 can be set to 30%D0, 50%D0, 70%D0, 85%D0, or any value between the two.

[0059] In some embodiments, if the diameter D0 of the cover plate 1 is set to 50 mm, then the diameter D2 of the arc segment 111 is set in the range of 15 mm to 42.5 mm. For example, the diameter D2 of the arc segment 111 is set to 15 mm, 30 mm, 40 mm, 42.5 mm, or any value between the two.

[0060] In some embodiments, the diameter of the arc segment 111 is the mean diameter of the arc segment 111. That is, the diameter corresponding to the circumference line between the inner diameter and the outer diameter of the arc segment 111.

[0061] like Figure 3 As shown, in some embodiments, the thickness of the cover plate 1 is T1, and the thickness of the thinning region 11 is T2, satisfying: 0.16T1≤T1-T2≤0.8T1.

[0062] It is understandable that T1-T2 represents the cavity height at the thinning zone 11. If T1-T2 is less than 0.16T1, the thinning effect of the thinning zone 11 is not significant, resulting in a weak stress concentration effect. If T1-T2 is greater than 0.8T1, the thickness of the thinning zone 11 will approach the thickness of the notch 12 itself, leading to an excessively low valve opening threshold and potentially causing premature or accidental pressure release.

[0063] In some embodiments, the thickness difference between the cover plate 1 and the thinning region 11 can be set to 0.16T1, 0.5T1, 0.8T1, or any value between the two.

[0064] like Figure 4 As shown, in some embodiments, the width of the notch 12 decreases along the direction from the opening of the notch 12 to the bottom surface.

[0065] Understandably, setting the notch 12 to a shape with a large opening and a small bottom surface helps to increase the strength of the forming mold and reduce the resistance during stamping.

[0066] In some embodiments, the cross-section of the notch 12 is configured as an inverted trapezoidal structure so that the opening width of the notch 12 is large and the bottom width is small.

[0067] Please continue reading. Figure 4 In some embodiments, the thickness of the cover plate 1 is T1, and the width of the opening of the notch 12 is B1, satisfying: 0.1T1≤B1≤2T1.

[0068] It is understandable that setting the width of the opening of the notch 12 within the range of 0.1T1 to 2T1 ensures that the notch 12 can be formed while avoiding excessive processing resistance. If the width of the opening of the notch 12 is less than 0.1T1, the bottom surface of the notch 12 will be too narrow to form properly because its width is smaller than the width of the opening. If the width of the opening of the notch 12 is greater than 2T, the forming mold will be too wide, resulting in excessive resistance during the forming process. Excessive forming resistance will accelerate mold wear, increase maintenance costs, prolong downtime, and reduce production efficiency. Excessive forming resistance will also cause a decrease in processing accuracy, resulting in uneven depth and width of the notch 12, and even defects such as burrs and cracks. Excessive forming resistance may also cause deformation of the cover plate 1, reducing its yield.

[0069] In some embodiments, the width of the opening of the notch 12 is set to 0.1T1, 0.5T1, 1.0T1, 1.5T1, 2.0T1, or any value between the two.

[0070] In some embodiments, if the thickness of the cover plate 1 is set to 1 mm, then the width of the opening of the notch 12 is set to a range of 0.1 mm to 2 mm. For example, the width of the opening of the notch 12 is set to 0.1 mm, 0.5 mm, 1.0 mm, 1.5 mm, 2.0 mm, or any value between any two.

[0071] Please continue reading. Figure 4 In some embodiments, the width of the bottom surface of the notch 12 is B2, satisfying: 0.1B1≤B2≤0.8B1.

[0072] Understandably, if the width of the bottom surface of the notch 12 is less than 0.1B1, the valve opening threshold of the cover plate 1 will be too small, leading to premature pressure release or accidental triggering of pressure release in the individual cell 2, and there may also be a risk of leakage. A width of less than 0.1B1 may also make it difficult to form the notch 12. If the width of the bottom surface of the notch 12 is greater than 0.8B1, the valve opening threshold of the cover plate 1 will be too large, easily leading to delayed pressure release, reducing the safety of the individual cell 2, and making it more susceptible to thermal runaway propagation and increased risk of explosion.

[0073] In some embodiments, the width of the bottom surface of the notch 12 is set to 0.1B1, 0.5B1, 0.8B1, or any value between the two.

[0074] In some embodiments, if the width of the opening of the notch 12 is set to 1 mm, then the width of the bottom surface of the notch 12 is set to 0.1 mm, 0.5 mm, 1.0 mm, or any value between the two.

[0075] Please continue reading. Figure 4 In some embodiments, the thickness of the cover plate 1 is T1, and the depth of the notch 12 is H, satisfying: 0.3T1≤H≤0.95T1.

[0076] Understandably, if the depth of the notch 12 is less than 0.3T1, the valve opening threshold of the cover plate 1 will be too high, which will easily lead to delayed pressure relief, reduce the safety of the individual cell 2, and make the individual cell 2 more prone to thermal runaway propagation and increased risk of explosion. If the depth of the notch 12 is greater than 0.95T1, the valve opening threshold of the cover plate 1 will be too low, causing the individual cell 2 to depressurize prematurely or be accidentally depressurized, and there may also be a risk of leakage.

[0077] In some embodiments, the depth of the notch 12 is set to 0.3T1, 0.5T1, 0.7T1, 0.95T1, or any value between the two.

[0078] In some embodiments, if the thickness of the cover plate 1 is set to 1 mm, then the depth of the notch 12 is set to 0.3 mm, 0.5 mm, 0.95 mm, or any value between the two.

[0079] The embodiments of this utility model have been described in detail above. Specific examples have been used to illustrate the principles and implementation methods of this utility model. The description of the above embodiments is only for the purpose of helping to understand the method and core ideas of this utility model. At the same time, for those skilled in the art, there will be changes in the specific implementation methods and application scope based on the ideas of this utility model. Therefore, the content of this specification should not be construed as a limitation of this utility model.

Claims

1. A cover plate (1), characterized in that, The cover plate (1) has at least two thinning areas (11) spaced apart in the circumferential direction, and a groove (12) connecting each two adjacent thinning areas (11). At least two of the thinning regions (11) are located on the first circumference of the cover plate (1), and the diameter of the first circumference is D1. At least two of the grooves (12) are located on the second circumference of the cover plate (1), and the diameter of the second circumference is D2, satisfying: D2 < D1.

2. The cover plate (1) according to claim 1, characterized in that, The groove (12) includes an arc segment (111) and a first connecting segment (112) and a second connecting segment (113) connected to both ends of the arc segment (111). The arc segment (111) shares the same center with the cover plate (1). The first connecting segment (112) is connected to one of the thinning areas (11), and the second connecting segment (113) is connected to another thinning area (11).

3. The cover plate (1) according to claim 2, characterized in that, The diameter of the cover plate (1) is D0, and the diameter of the arc segment (111) is D2, satisfying: 30%D0≤D2≤85%D0.

4. The cover plate (1) according to any one of claims 1 to 3, characterized in that, The thickness of the cover plate (1) is T1, and the thickness of the thinning region (11) is T2, satisfying: 0.16T1≤T1-T2≤0.8T1.

5. The cover plate (1) according to any one of claims 1 to 3, characterized in that, The width of the groove (12) decreases from the opening to the bottom surface.

6. The cover plate (1) according to claim 5, characterized in that, The thickness of the cover plate (1) is T1, and the width of the opening of the groove (12) is B1, satisfying: 0.1T1≤B1≤2T1.

7. The cover plate (1) according to claim 6, characterized in that, The width of the bottom surface of the groove (12) is B2, which satisfies: 0.1B1≤B2≤0.8B1.

8. The cover plate (1) according to claim 5, characterized in that, The thickness of the cover plate (1) is T1, and the depth of the groove (12) is H, satisfying: 0.3T1≤H≤0.95T1.

9. A single-cell battery cell (2), characterized in that, Includes the cover plate (1) as described in any one of claims 1 to 8.

10. A battery pack, characterized in that, Includes the single-cell battery cell (2) as described in claim 9.

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