Battery and battery module

Abstract

To provide a battery and battery module that can improve the pressure relief capability when the battery is thermally runaway and avoid the risk of explosion when the battery is thermally runaway.SOLUTION: The present disclosure provides a battery and a battery module. The battery includes a battery case and a cap assembly, the battery case includes a body, the body includes a side wall extending along the first direction and an end wall connecting to one end of the side wall, the end wall includes first and second surfaces opposite to each other in the first direction, the first surface faces the explosion-proof sheet and a recessed groove is installed in the second surface of the end wall, and the recessed groove is recessed from the second surface to the first surface.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] This disclosure claims the priority of a Chinese patent application filed with the China National Intellectual Property Administration on December 18, 2023, with an application number of 202323460665.4, the priority of a Chinese patent application filed with the China National Intellectual Property Administration on December 18, 2023, with an application number of 202311750467.3, and the priority of a Chinese patent application filed with the China National Intellectual Property Administration on December 18, 2023, with an application number of 202323459472.7. The entire content of the above applications is incorporated herein by reference. This disclosure relates to the field of battery technology, and specifically to batteries and battery modules.

Background Art

[0002] In related technologies, in order to quickly release the pressure inside the battery when the battery is in a thermal runaway situation, an explosion-proof valve is installed near the end of the battery. When the pressure inside the battery is too high, the high-pressure gas inside the battery breaks through the explosion-proof valve to release the pressure, thereby avoiding the occurrence of safety accidents.

Summary of the Invention

Problems to be Solved by the Invention

[0003] However, in such an installation method, when the pressure inside the battery increases rapidly, when the explosion-proof valve is delayed in releasing the pressure, the battery still has a risk of bursting and exploding due to excessive internal pressure.

Means for Solving the Problems

[0004] In a first aspect, the present disclosure provides a battery. The battery includes a battery case and a cap assembly. The battery case includes a main body, and the main body includes a side wall extending along a first direction and an end wall connected to one end of the side wall. The cap assembly is installed on a side of the side wall away from the end wall and includes an explosion-proof sheet. The explosion-proof sheet faces the end wall. The end wall includes a first surface and a second surface facing each other in the first direction. The first surface faces the explosion-proof sheet, and a concave groove is installed on the second surface of the end wall. The concave groove is recessed from the second surface toward the first surface. When the vertical distance from the lowermost part of the concave groove to the first surface in the first direction is D, 0.03 mm ≤ D ≤ 0.08 mm is satisfied.

[0005] In a second aspect, the present disclosure provides a battery module. The battery module includes a plurality of batteries.

Advantages of the Invention

[0006] In an embodiment of the present disclosure, a concave groove is installed on the end wall of the main body. The concave groove and the explosion-proof sheet are respectively located at both ends of the battery case in the first direction. When the battery undergoes thermal runaway and the internal pressure is too high, both the location of the concave groove on the end wall and the explosion-proof sheet collapse, and the high-pressure gas inside the battery is discharged to the outside of the battery simultaneously from the location of the end wall and the location of the explosion-proof sheet. Thereby, the pressure relief ability when the battery undergoes thermal runaway is enhanced, and the risk of explosion when the battery undergoes thermal runaway can be avoided.

Brief Description of the Drawings

[0007]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

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Figure 8

Figure 9

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Figure 11

Figure 12

Embodiments for Carrying Out the Invention

[0008] In the description of the present disclosure, unless otherwise clearly defined and limited, the terms "connected", "connected to", and "fixed" should be understood in a broad sense. For example, it may be a fixed connection, a detachable connection, integrated, a mechanical connection, an electrical connection, directly connected, indirectly connected through an intermediate medium, or refer to the internal connection or interaction relationship between two elements. Those skilled in the art can understand the specific meaning of the above terms in the present disclosure according to specific situations.

[0009] In the present disclosure, unless otherwise clearly defined and limited, the fact that the first feature is "above" or "below" the second feature may include that the first feature and the second feature are in direct contact, or may also include that the first and second features are not in direct contact but contact through another feature therebetween. And the fact that the first feature is "above", "above", "upper surface" of the second feature means that the first feature is directly above or obliquely above the second feature, and the horizontal height of the first feature is higher than that of the second feature. The fact that the first feature is "below", "below", "lower surface" of the second feature means that the first feature is directly below or obliquely below the second feature, and the horizontal height of the first feature is lower than that of the second feature.

[0010] In the description of this embodiment, the orientation or positional relationship of terms such as "upper", "lower", "left", "right", "front", and "rear" is based on the orientation or positional relationship shown in the drawings, for the purpose of simplifying the description and operation, and does not mean that the indicated device or element must have a specific orientation, be configured and operated in a specific orientation. Therefore, it should not be understood as a limitation to the present disclosure. Also, the terms "first" and "second" are used for the purpose of distinction in the description and have no special meaning.

[0011] Referring to FIGS. 1, 4, 5, and 8, the battery 1000 includes a battery case 100 and a cap assembly 200. The battery case 100 includes a main body 1. The main body 1 includes a side wall 11 extending along a first direction X and an end wall 12 connected to one end of the side wall 11. The cap assembly 200 is installed on the side away from the end wall 12 of the side wall 11 and includes an explosion-proof sheet 4. The explosion-proof sheet 4 faces the end wall 12. The end wall 12 includes a first surface 121 and a second surface 122 facing each other in the first direction X. The first surface 121 faces the explosion-proof sheet 4, and a concave groove 2 is installed on the second surface 122 of the end wall 12. The concave groove 2 is recessed from the second surface 122 toward the first surface 121. If the vertical distance from the lowermost part of the concave groove 2 in the first direction X to the first surface 121 is D, then D satisfies 0.03 mm ≤ D ≤ 0.08 mm.

[0012] In the embodiment of the present disclosure, a concave groove 2 is installed on the end wall 12 of the main body 1. The concave groove 2 and the explosion-proof sheet 4 are respectively located at both ends of the battery case 100 in the first direction X. When the battery 1000 undergoes thermal runaway and the internal pressure is too high, both the location of the concave groove 2 on the end wall 12 and the explosion-proof sheet 4 collapse, and the high-pressure gas inside the battery 1000 is discharged to the outside of the battery 1000 simultaneously from the location of the end wall 12 and the location of the explosion-proof sheet 4. Thereby, the pressure relief ability when the battery 1000 undergoes thermal runaway is enhanced, and the risk of explosion when the battery 1000 undergoes thermal runaway can be avoided.

[0013] In addition, when the D value is less than 0.03 mm, there is a risk that the structural strength of the local position of the end wall 12 of the battery case 100 is insufficient, and the pressure relief of the explosion-proof sheet 4 does not collapse, but may collapse at the concave groove 2, and there is a risk that the battery case 100 may explode. Of course, when the D value is less than 0.03 mm, when the concave groove 2 is processed and formed on the end wall 12, cracks are likely to occur on the end wall 12. When the D value exceeds 0.08 mm, if the pressure relief of the explosion-proof sheet 4 collapses, it does not collapse at the concave groove 2, and pressure relief cannot be performed on the gas inside the battery 1000 at the end wall 12, and the battery case 100 may explode.

[0014] Also, by setting the vertical distance D from the bottommost part of the concave groove 2 in the first direction X to the first surface 121 within the range of 0.03 mm to 0.08 mm, when the internal pressure of the battery 1000 reaches between 1.90 MPa and 3.15 MPa, the explosion-proof sheet 4 and the end wall 12 can both collapse, meeting the design requirement of performing pressure relief on the high-pressure gas inside the battery 1000. In some embodiments of the present disclosure, the explosion-proof sheet 4 collapses when the internal pressure of the battery 1000 reaches between 1.90 MPa and 2.73 MPa, and the explosion-proof sheet 4 also collapses when the pressure at the moment of thermal runaway of the battery 1000 exceeds 2.73 Mpa. Here, there is a structural design in which the concave groove 2 is installed on the end wall 12. When the D value satisfies 0.03 mm ≤ D ≤ 0.08 mm, the end wall 12 can collapse when the internal pressure of the battery 1000 reaches 1.90 MPa to 3.15 MPa.

[0015] In some embodiments of the present disclosure, the end wall 12 collapses when the internal pressure of the battery 1000 reaches 2.70 MPa to 3.15 MPa. With such a setting, when the internal pressure of the battery 1000 has not reached the pressure at which the end wall 12 collapses, that is, when it is between 1.90 MPa and 2.70 MPa, pressure relief can be performed through the explosion-proof sheet 4 to avoid the end wall 12 of the battery case 100 being damaged and causing danger. And when the internal pressure of the battery 1000 is too high, that is, when it is between 2.70 MPa and 3.15 MPa, in order to avoid the danger caused by the destruction of the entire battery case 100, pressure relief can be jointly performed through the explosion-proof sheet 4 and the location of the end wall 12.

[0016] Referring to FIG. 2, in one embodiment of the present disclosure, the cap assembly 200 includes a seal portion 3A, and the explosion-proof sheet 4 is installed in the space formed by the seal 3A surrounding it.

[0017] Referring to FIG. 5, in some embodiments of the present disclosure, the concave groove 2 is formed in an arc shape. The concave groove 2 includes a first groove wall 21 and a second groove wall 22 that are oppositely installed along the radial direction of the circle where the concave groove 2 is located. Both the first groove wall 21 and the second groove wall 22 are formed in an arc shape. The plane where the first groove wall 21 is located intersects with the plane where the second groove wall 22 is located. If the angle formed by the plane where the first groove wall 21 is located and the plane where the second groove wall 22 is located is θ, then the θ satisfies 25° ≤ θ ≤ 65°. With such a setting, based on the fact that the opening size of the concave groove 2 is the same, the groove bottom area of the concave groove 2 is reduced, and the collapse area at the location of the concave groove 2 during pressure relief of the battery case 100 is decreased. In one embodiment of the present disclosure, θ further satisfies 50° ≤ θ ≤ 65°. That is, in this embodiment, by further limiting the dimension of θ to be between 50° and 65°, based on the fact that the opening size of the concave groove 2 is the same, the groove bottom area of the concave groove 2 can be further restricted, and the collapse area at the location of the concave groove 2 during pressure relief of the battery case 100 can be decreased.

[0018] In some embodiments of the present disclosure, the concave groove 2 further includes a third groove wall 23 connecting the first groove wall 21 and the second groove wall 22. The lowermost part of the concave groove 2 is located on the third groove wall 23. The third groove wall 23 is formed in an arc shape. The center of the circle corresponding to the arc where the third groove wall 23 is located is located within the concave groove 2. When the radius of the circle where the arc shape of the third groove wall 23 is located is R, the R satisfies 0.05 mm ≤ R ≤ 0.1 mm. In this embodiment, since the head position of the press die for processing the concave groove 2 in the related art is provided with a rounded corner, the radius of the center of the circle corresponding to the arc where the third groove wall 23 is located is installed within the range of 0.05 mm to 0.1 mm. That is, when the press die is pressed, the third groove wall 23 with a radius R located between 0.05 mm and 0.1 mm is formed. Similarly, since the head of the press die for processing the concave groove 2 is provided with a rounded corner, it is possible to avoid damaging the pressed part of the end wall 12 during pressing, and it is possible to avoid the groove width of the concave groove 2 after pressing being too large.

[0019] Referring to FIGS. 2, 3 and 6, in some embodiments of the present disclosure, a notch 5 is provided in the explosion-proof sheet 4. The notch 5 is formed in an arc shape. If the angle between the line connecting the center of the circle where the notch 5 is located and one end of the notch 5 and the line connecting the center of the circle where the notch 5 is located and the other end of the notch 5 is α, then 0°≤α≤22°. The concave groove 2 is formed in an arc shape. If the angle between the line connecting the center of the circle where the concave groove 2 is located and both ends of the concave groove 2 is β, then 0°≤β≤22°. In this embodiment, by setting the angle α between the line connecting the center of the circle where the notch 5 is located and one end of the notch 5 and the line connecting the center of the circle where the notch 5 is located and the other end of the notch 5, and the angle β between the line connecting the center of the circle where the concave groove 2 is located and one end of the concave groove 2 and the line connecting the center of the circle where the concave groove 2 is located and the other end of the concave groove 2 to be both within the range of 0° to 22°, the similarity of the pressure relief paths at both ends of the battery 1000 in the first direction X can be enhanced, and further the effect of uniform exhaust gas pressure relief inside the battery 1000 can be enhanced. As can be understood, when the α value takes a fixed value within the range of 0° to 22°, the β value can take any value within the range of 0° to 22° to design the dimensions of the concave groove 2. Similarly, when the β value takes a fixed value within the range of 0° to 22°, the α value can take any value within the range of 0° to 22° to design the dimensions of the concave groove 5.

[0020] In one embodiment of the present disclosure, the α value is between 18° and 22°, that is, 18°≤α≤22°, and the β value is between 0° and 22°, that is, 0°≤β≤22°.

[0021] In some embodiments of the present disclosure, the notch 5 and the concave groove 2 are installed opposite to each other in the first direction X. That is, in this embodiment, by setting it in this way, the consistency of the pressure relief paths of the high-pressure gas at both ends where the battery 1000 is located in the first direction X can be further enhanced, and when the battery 1000 is in pressure relief due to thermal runaway, the explosion of the battery case 100 can be avoided.

[0022] Referring to FIGS. 7-8, the end wall 12 includes a first region 12A and a second region 12B configured to be welded to the current collector 3, and at least a part of the concave groove 2 is disposed in the first region 12A. Here, the end wall 12 has a reduced thickness in the first direction X at a local position where the concave groove 2 is formed. However, since a welding connection is required between the current collector 3 and the end wall 12 during the assembly and molding of the battery 1000, the thickness of the end wall 12 in the first direction X is reduced at the local position where the concave groove 2 is formed. In order to avoid affecting the welding of the current collector 3, and further to perform welding through the end wall 12 during the welding of the current collector 3 and the end wall 12, in this embodiment, at least a part of the opening position of the concave groove 2 is offset from the welding position of the current collector 3 on the end wall 12. That is, at least a part of the concave groove 2 is disposed in the first region 12A, and the welding region between the current collector 3 and the end wall 12 is located in the second region 12B.

[0023] As can be understood, in the second region 12B, a part of the position of the end wall 12 is welded to the current collector 3. Therefore, a part of the concave groove 2 can also be located in the region where the end wall 12 is not welded to the current collector 3 in the second region 12B. However, since the specific welding position of the current collector 3 in the second region 12B is not limited, in order to be applicable to the manufacturing process of the welding method of the current collector 3 with different opening positions of the concave groove 2, in one embodiment of the present disclosure, the entire part of the concave groove 2 is located in the first region 12A.

[0024] Also, the welding form between the current collector 3 and the end wall 12 may be spot welding or wire welding, etc. In one embodiment, when a part of the concave groove 2 is located in the second region 12B, the welding part between the current collector 3 and the end wall 12 needs to be offset from the installation position of the concave groove 2.

[0025] In some embodiments of the present disclosure, the second region 12B includes a first sub-region 1A and a second sub-region 1B, and the first region 12A is located between the first sub-region 1A and the second sub-region 1B. Here, in the related art, the welding regions of the current collector 3 and the end wall 12 are located in two different regions on the end wall 12 respectively. That is, based on this, two of the two different regions on the end wall 12 where the welding regions of the current collector 3 and the end wall 12 are located in the related art are the first sub-region 1A and the second sub-region 1B of this embodiment respectively. Here, the first region 12A is located within the first sub-region 1A and the second sub-region 1B. In order to satisfy the welding region between the end wall 12 and the current collector 3 in the related art, at least a part of the concave groove 2 is installed in the first region 12A to avoid the end wall 12 being penetrated and welded when the end wall 12 and the current collector 3 are welded.

[0026] As can be understood, in one embodiment, the welding region of the current collector 3 may be located only in the first sub-region 1A. In another embodiment, the welding region of the current collector 3 may be located only in the second sub-region 1B. In yet another embodiment, the welding region of the current collector 3 may be located in both the first sub-region 1A and the second sub-region 1B simultaneously. Here, the dimensional design of a part of the concave groove 2 can avoid the section ranges of the first sub-region 1A and the second sub-region 1B simultaneously, and the battery case 100 can be simultaneously applied to the manufacturing processes of different welding methods of the current collector 3, thereby enhancing the versatility of the battery case 100.

[0027] In some embodiments of the present disclosure, the first sub-region 1A is formed in a circular shape, the second sub-region 1B is formed in an annular shape, the concave groove 2 is formed in an arc shape, the concave groove 2 includes a first side 2A and a second side 2B that are oppositely disposed along the radial direction of the circle where the concave groove 2 is located, both the first side 2A and the second side 2B are formed in an arc shape, the diameter of the circle where the first side 2A is located is denoted as L1, the diameter of the circle where the second side 2B is located is denoted as L2, the diameter of the first sub-region 1A is denoted as L3, and the inner diameter of the second sub-region 1B is denoted as L4. Then, L1, L2, L3, and L4 satisfy L3 ≤ (L1 + L2) / 2 ≤ L4. As can be understood, since the first sub-region 1A is formed in a circular shape, the second sub-region 1B is formed in an annular shape, and the concave groove 2 is formed in an arc shape, that is, by designing such that the diameter of the circle where the concave groove 2 is located is positioned between the diameter L3 of the first sub-region 1A and the inner diameter L4 of the second sub-region 1B, it is possible to avoid the opening of the concave groove 2 interfering with the welding of the current collector 3 and the end wall 12. And based on this, since the concave groove 2 includes the first side 2A and the second side 2B in the radial direction of the circle where it is located, (L1 + L2) is the median of the shortest straight-line distance between the first side 2A and the second side 2B in the radial direction of the circle where the concave groove 2 is located. By setting it in this way, the opening of the concave groove 2 located on the end wall 12 is prevented from interfering with the welding of the end wall 12 and the current collector 3.

[0028] In some embodiments of the present disclosure, L3 and L4 further satisfy 2 mm ≤ L3 ≤ 6 mm and L4 ≥ 12 mm. That is, in this embodiment, the dimension range of L3 is the welding range between the current collector 3 and the end wall 12 in the first sub-region 1A, and the dimension range of L4 is the welding range between the current collector 3 and the end wall 12 in the second sub-region 1B. Here, the outer diameter of the second sub-region 1B is L5, and L5 further satisfies L5 ≤ 15 mm. That is, the dimension range between 12 mm and 15 mm is the welding range between the current collector 3 and the end wall 12 in the second sub-region 1B. Therefore, in one embodiment of the present disclosure, by installing such that 6 mm ≤ (L1 + L2) / 2 ≤ 12 mm, at least a part of the concave groove 2 can be located within the first region 12A, and the opening of the concave groove 2 is prevented from interfering with the specific positions of the welding of the current collector 3 and the end wall 12 in the first sub-region 1A and the second sub-region 1B.

[0029] In some embodiments of the present disclosure, L1 and L2 further satisfy 8 mm ≤ (L1 + L2) / 2 ≤ 10 mm. With such a setting, the entire concave groove 2 is located within the first interval, thereby preventing the opening of the concave groove 2 from interfering with the welding between the end wall 12 and the current collector 3 in the first sub-region 1A and / or the second sub-region 1B.

[0030] Referring to FIG. 4, in some embodiments of the present disclosure, when the vertical distance from the first surface 121 to the second surface 122 of the end wall 12 in the first direction X is H, the H satisfies 0.3 mm ≤ H ≤ 0.8 mm. That is, in this embodiment, with such a setting, the strength of the battery case 100 can meet the requirements in use. If H is less than 0.3 mm, the strength of the battery case 100 may be insufficient. If H exceeds 0.8 mm, the overall thickness of the end wall 12 in the first direction X becomes too thick, making it difficult for the end wall 12 to collapse, and there is a risk of pressure relief for the high-pressure gas inside the battery 1000.

[0031] Referring to FIG. 4, in some embodiments of the present disclosure, when the end wall 12 is formed in a circular shape and the diameter of the end wall 12 is L6, the L6 satisfies 18.10 mm ≤ L6 ≤ 21.40 mm. That is, in this embodiment, the dimensional design of the D value, R value, θ value, β value, L1 value, and L2 value of the concave groove 2 on the end wall 12 can be applied to the product of the battery 1000 with the diameter of the end wall 12 of the battery case 100 being 18.10 mm to 21.40 mm to avoid the case explosion when the product of the battery 1000 with the diameter of the end wall 12 of the battery case 100 being 18.10 mm to 21.40 mm undergoes thermal runaway. Also, in some embodiments of the present disclosure, the material of the battery case 100 is steel.

[0032] Hereinafter, some embodiments will be used to describe the technical solutions and technical effects of the present application in detail.

Table 1

[0033] Referring to FIGS. 9 to 11, the side wall 11 includes a main body portion 11A formed in a cylindrical shape and a port portion 12A connected to the main body portion 11A. An end face 2A is provided on the side of the port portion 12A away from the main body portion 11A. The cap assembly 200 further includes a seal portion 3A. The seal portion 3A includes a fitting portion 31 and a convex portion 32. The fitting portion 31 is formed by bending from the port portion 12A to the inner wall of the main body portion 11A to tighten the seal portion 3A. At least a part of the end face 2A is fitted into the fitting portion 31. The convex portion 32 is connected to the fitting portion 31, and the convex portion 32 covers the region of the end face 2A that is not fitted into the fitting portion 31.

[0034] In an embodiment of the present disclosure, the fitting portion 31 and the convex portion 32 cover and protect the end face 2A of the port portion 12A where plating protection is not provided, avoiding direct contact of the end face 2A with air and further improving the rusting of the end face 2A.

[0035] As can be understood, bending the side wall 11 of the battery 1000, that is, bending the port portion 12A, can fix the seal portion 3A and other components inside the battery 1000. In some embodiments of the present disclosure, since the seal portion 3A has a certain elastic deformation ability, when the port portion 12A presses the fitting portion 31, a part of the fitting portion 31 close to the end face 2A shields a part of the end face 2A due to its own deformation, and together with the convex portion 32 provided on the fitting portion 31, shields the entire part of the end face 2A.

[0036] Referring to FIGS. 9, 11 and 12, in some embodiments of the present disclosure, the battery 1000 further includes a cap body 6. The cap body 6 is installed in a cavity 5A close to the port portion 12A of the main body portion 11A. A seal area 6A is installed at the interval between the edge of the cap body 6 and the inner wall of the main body portion 11A. At least a part of the seal portion 3A is installed in the seal area 6A. The seal portion 3A is press-fitted with the edge of the cap body 6 and the inner wall of the main body portion 11A. That is, in this embodiment, the seal portion 3A seals the gap between the cap body 6 and the main body portion 11A, that is, seals the seal area 6A. In order to ensure the sealing performance of the seal area 6A between the cap body 6 and the main body portion 11A, the seal portion 3A and a part of the cap body 6 and a part of the main body portion 11A are press-fitted to improve the sealing performance of the seal area 6A.

[0037] In some embodiments of the present disclosure, a pressure-receiving surface 41A is installed on the cap body 6. The port portion 12A is bent on the inner wall of the main body portion 11A to tighten the seal portion 3A. The seal portion 3A abuts against the pressure-receiving surface 41A to form a fitting portion 31. That is, in this embodiment, a part of the seal portion 3A located between the port portion 12A and the pressure-receiving surface 41A of the cap body 6 is also press-fitted between a part of the port portion 12A and the cap body 6, so that a part of the seal portion 3A located on the end surface 2A is deformed to form the fitting portion 31.

[0038] Referring to FIGS. 9, 11 and 12. In some embodiments of the present disclosure, the port portion 12A is installed to extend obliquely in a direction approaching the cap body 6. That is, in this embodiment, the vertical distance in the first direction X from one end where the port portion 12A is connected to the main body portion 11A to the cap body 6 in the second direction Y is greater than the vertical distance in the first direction X from the end surface 2A to the cap body 6. Therefore, the certainty and sealing performance of the fixation of the three components, namely, the side wall 11, the cap body 6 and the seal portion 3A, can be ensured.

[0039] Refer to FIG. 9. In some embodiments of the present disclosure, when the angle formed between the extension line where the port portion 12A is located and the plane where the cap body 6 is located is γ, γ satisfies 4° ≤ γ ≤ 20°. With such a setting, when the port portion 12A bends and tightens the seal portion 3A, at least a part of the end face 2A can be wrapped and protected by the fitting portion 31, and at the same time, the gap between the port portion 12A and the seal portion 3A, and the gap between the seal portion 3A and the cap body 6 can also be sealed. When γ < 4°, the sealing performance between the side wall 11, the seal portion 3A and the cap body 6 may deteriorate. When γ > 20°, since the seal portion 3A is installed between the port portion 12A and the cap body 6, a certain interference will occur in the bending of the port portion 12A, and the bending angle of the port portion 12A will not increase. Also, if the bending angle of the port portion 12A is too large, the seal portion 3A will be overly tightened, and the deformation of the seal portion 3A will exceed its elastic limit, thereby affecting the sealing performance between the side wall 11 and the cap body 6.

[0040] Refer to FIG. 10. In some embodiments of the present disclosure, when a part of the length of the seal portion 3A on the pressure receiving surface 41A side in the second direction is L7, and the length of the fitting portion 31 in the second direction is L8, L7 and L8 satisfy 0.1×L7 ≤ L8 ≤ 0.4×L7. That is, with such a setting, when L8 is within this section range, the fitting portion 31 and the convex portion 32 can cover the end face 2A. When L8 > 0.4×L7, a part of the seal portion 3A may warp, which may cause a defective appearance of the seal portion 3A. When L8 < 0.1×L7, the fitting portion 31 and the convex portion 32 will affect the rust prevention and protection function for the end face 2A. That is, when an external force acts on the fitting portion 31 and the convex portion 32, they will easily separate from the end face 2A.

[0041] Refer to FIG. 10. In some embodiments of the present disclosure, when the maximum vertical distance from the side of the cap body 6 of the convex portion 3 away from the pressure-receiving surface 41A in the first direction is L9, and the minimum vertical distance from the end face 2A to the pressure-receiving surface 41A in the first direction is L10, L9 and L10 satisfy 0.6×L9≦L10≦0.9×L9. That is, when set in this way, the fitting portion 31 and the convex portion 32 can cover the end face 2A. When L10 < 0.6×L9, part of the sealing portion 3A may warp, which may cause poor appearance of the sealing portion 3A. When L10 > 0.9×L9, the rust prevention protection function of the fitting portion 31 and the convex portion 32 with respect to the end face 2A is affected. That is, there is a possibility that the convex portion 32 and the fitting portion 31 cannot completely cover the end face 2A.

[0042] Also, in some embodiments of the present disclosure, the battery 1000 also includes a rust inhibitor, and the rust inhibitor is installed on the end face 2A. That is, in this embodiment, the rust inhibitor, the fitting portion 31, and the convex portion 32 jointly protect to strengthen the rust prevention protection for the end face 2A.

[0043] Here, the rust inhibitor may be a rust preventive oil, a rust preventive paint, a rust preventive adhesive, or the like. In one embodiment of the present disclosure, the rust inhibitor is installed in the rust preventive oil.

[0044] The present disclosure further provides a battery module. The battery module includes a plurality of batteries 1000. Since this battery module adopts the technical solutions of all embodiments of the battery 1000, it has at least the beneficial effects brought by the technical solutions of all embodiments including the battery 1000. This is omitted here.

Description of Reference Numerals

[0045] 1000: Battery 100: Battery Case 1: Body 11: Side Wall 12: End Wall 12A: First Region 12B: Second Region 1A: First Sub-Region 1B: Second Sub-Region 2: Concave Groove 3: Current collector 200: Cap assembly 4: Explosion-proof sheet 5: Notch 121: First surface 122: Second surface 21: First groove wall 22: Second groove wall 23: Third groove wall 2A: First side 2B: Second side 6: Cap body 11A: Body part 12A: Port part 2A: End face 3A: Seal part 31: Fitting part 32: Protrusion 6: Cap body 5A: Cavity 6A: Seal area 41A: Pressure-receiving surface

Claims

1. A battery, The battery includes a battery case (100) and a cap assembly (200), The battery case (100) includes a main body (1), the main body (1) including a side wall (11) extending along a first direction and an end wall (12) connected to one end of the side wall (11); The cap assembly (200) is installed on the side of the side wall (11) away from the end wall (12) and includes an explosion-proof sheet (4), the explosion-proof sheet (4) faces the end wall (12), The end wall (12) includes a first surface (121) and a second surface (122) facing each other in the first direction, the first surface (121) faces the explosion-proof sheet (4), a groove (2) is provided in the second surface (122) of the end wall (12), the groove (2) is recessed from the second surface (122) toward the first surface (121), and the vertical distance from the bottom of the groove (2) to the first surface (121) in the first direction is D, where D satisfies 0.03 mm≦D≦0.08 mm. A battery characterized in that

2. The groove (2) is formed in an arc shape, and includes a first groove wall (21) and a second groove wall (22) that are disposed opposite each other along a radial direction of a circle in which the groove (2) is located, and both the first groove wall (21) and the second groove wall (22) are formed in an arc shape, and a plane in which the first groove wall (21) is located intersects with a plane in which the second groove wall (22) is located, When the angle between the plane on which the first groove wall (21) is located and the plane on which the second groove wall (22) is located is θ, the angle θ satisfies 25°≦θ≦65°.

2. The battery according to claim 1 .

3. The θ further satisfies 50°≦θ≦65°, 3. The battery according to claim 2 .

4. the groove (2) further includes a third groove wall (23) connecting the first groove wall (21) and the second groove wall (22), the lowest part of the groove (2) is located on the third groove wall (23), the third groove wall (23) is formed in an arc shape, and the center of a circle corresponding to the arc on which the third groove wall (23) is located is located within the groove (2); When the radius of the circle on which the arc shape of the third groove wall (23) is located is R, the radius R satisfies 0.05 mm≦R≦0.1 mm.

3. The battery according to claim 2 .

5. A cutout (5) is provided in the explosion-proof sheet (4), the cutout (5) is formed in an arc shape, and the angle between a line connecting the center of the circle in which the cutout (5) is located to one end of the cutout (5) and a line connecting the center of the circle in which the cutout (5) is located to the other end of the cutout (5) is α, where α satisfies 0°≦α≦22°, The groove (2) is formed in an arc shape, and the angle between the center of the circle in which the groove (2) is located and the line connecting both ends of the groove (2) is β, and β satisfies 0°≦β≦22°.

5. The battery according to claim 1, wherein the first and second electrodes are electrically connected to each other.

6. The notch (5) and the groove (2) are disposed opposite to each other in the first direction; 6. The battery according to claim 5 .

7. the end wall (12) includes a first region (12A) and a second region (12B) configured to be welded to a current collector (3); At least a portion of the groove (2) is provided in the first region (12A); 5. The battery according to claim 1, wherein the first and second electrodes are electrically connected to each other.

8. The second region (12B) includes a first sub-region (1A) and a second sub-region (1B), and the first region (12A) is located between the first sub-region (1A) and the second sub-region (1B).

8. The battery according to claim 7 .

9. The first sub-region (1A) is formed in a circular shape, the second sub-region (1B) is formed in an annular shape, and the groove (2) is formed in an arc shape; The groove (2) includes a first side (2A) and a second side (2B) that are arranged opposite each other along a radial direction of a circle in which the groove (2) is located, and both the first side (2A) and the second side (2B) are formed in an arc shape; If the diameter of the circle on which the first side (2A) is located is L1, the diameter of the circle on which the second side (2B) is located is L2, the diameter of the first sub-region (1A) is L3, and the inner diameter of the second sub-region (1B) is L4, The L1, the L2, the L3, and the L4 satisfy L3≦(L1+L2) / 2≦L4.

9. The battery of claim 8.

10. The L3 and L4 further satisfy 2 mm≦L3≦6 mm and L4≧12 mm, 10. The battery of claim 9.

11. The L1 and L2 further satisfy 8 mm ≦ (L1 + L2) / 2 ≦ 10 mm, The battery of claim 10.

12. When a vertical distance from the first surface (121) to the second surface (122) of the end wall (12) in the first direction is H, the H satisfies 0.3 mm≦H≦0.8 mm.

5. The battery according to claim 1, wherein the first and second electrodes are electrically connected to each other.

13. The end wall (12) is formed in a circular shape, If the diameter of the end wall (12) is L6, the L6 satisfies 18.10 mm≦L6≦21.40 mm.

5. The battery according to claim 1, wherein the first and second electrodes are electrically connected to each other.

14. When the end wall (12) is collapsed, the internal pressure of the battery case (100) is A, and A satisfies 1.90 MPa≦A≦3.15 MPa.

5. The battery according to claim 1, wherein the first and second electrodes are electrically connected to each other.

15. the side wall (11) includes a main body portion (11A) formed in a cylindrical shape and a port portion (12A) connected to the main body portion (11A), and an end surface (2A) is provided on a side of the port portion (12A) away from the main body portion (11A); the cap assembly (200) further includes a sealing portion (3A), the sealing portion (3A) including a fitting portion (31) and a protrusion (32), the fitting portion (31) being formed by folding the port portion (12A) against an inner wall of the main body portion (11A) and compacting the sealing portion (3A), at least a portion of the end face (2A) being fitted into the fitting portion (31), the protrusion (32) being connected to the fitting portion (31), and the protrusion (32) covering an area of ​​the end face (2A) that is not fitted into the fitting portion (31); 2. The battery according to claim 1 .

16. The cap assembly (200) further includes a cap body (6), the cap body (6) is installed in a cavity (5A) close to the port portion (12A) of the body portion (11A), a sealing area (6A) is installed in a gap between an edge of the cap body (6) and an inner wall of the body portion (11A), at least a portion of the sealing portion (3A) is installed in the sealing area (6A), and the sealing portion (3A) is fitted tightly with the edge of the cap body (6) and the inner wall of the body portion (11A).

16. The battery of claim 15.

17. A pressure-receiving surface (41A) is provided on the cap body (6), the port portion (12A) is folded against the inner wall of the body portion (11A) to compact the seal portion (3A), and the seal portion (3A) is abutted against the pressure-receiving surface (41A) to form the fitting portion (31).

17. The battery of claim 16.

18. The port portion (12A) is installed to extend at an angle in a direction approaching the cap body (6).

20. The battery of claim 17 .

19. When an angle between an extension line on which the port portion (12A) is located and a plane on which the cap body (6) is located is defined as γ, the angle γ satisfies 4°≦γ≦20°.

20. The battery of claim 18.

20. When a length of a part of the seal portion (3A) on the pressure-receiving surface (41A) side in the second direction is L7, and a length of the fitting portion (31) in the second direction is L8, the L7 and L8 satisfy 0.1×L7≦L8≦0.4×L7.

20. The battery of claim 17 .

21. When the maximum vertical distance in the first direction from the side of the convex portion (32) away from the cap body (6) to the pressure-receiving surface (41A) is L9, and the minimum vertical distance in the first direction from the end face (2A) to the pressure-receiving surface (41A) is L10, the L9 and the L10 satisfy 0.6×L9≦L10≦0.9×L9.

20. The battery of claim 17 .

22. The battery further includes a rust remover, and the rust remover is disposed on the end surface (2A).

22. The battery according to any one of claims 15 to 21.

23. The rust remover is a rust remover oil.

23. The battery of claim 22.

24. A battery module, A battery comprising a plurality of batteries according to any one of claims 1 to 4. A battery module comprising:

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