Cap assembly, battery and battery pack

Abstract

The utility model provides a cap assembly, a battery and a battery pack. The cap assembly comprises an anti-explosion sheet, the pore plate comprises a pore plate welding area, and the anti-explosion sheet is welded to the pore plate welding area; wherein the pore plate welding area is provided with a hollow structure, the hollow structure comprises at least two through holes which are uniformly distributed along the circumferential direction of the pore plate welding area, a connecting bridge is arranged between the two through holes, and the connecting bridge is provided with pore plate nicks.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, concretely relates to a cap subassembly, battery and battery package. BACKGROUND

[0002] The cap subassembly of the cylindrical lithium ion secondary battery includes a hole plate and a rupture disc, the rupture disc is welded in the hole plate welding area, and a notch is arranged in the hole plate welding area, with the increase of the pressure in the battery, the hole plate at the notch breaks, and then the rupture disc and the hole plate are disconnected.

[0003] In the related art, the hole plate is made of 1 series aluminum material, the strength of the hole plate itself is low and thus is prone to deformation, so that the rupture disc deforms after being pressed against the hole plate in the process of turning over, and then the rupture disc and the hole plate are in contact and reconnected, so that the internal circuit of the battery cannot be disconnected. The applicant found that after using 3 series aluminum, the strength of the hole plate itself can be increased, but the residual wall thickness of the hole plate notch at the hole plate welding position is difficult to break due to the increase of the strength of the hole plate, and thus the explosion pressure threshold of the cap subassembly is affected. SUMMARY

[0004] Embodiments of the utility model provide a cap subassembly, battery and battery package, which can improve the technical problem that the hole plate is prone to deformation.

[0005] In a first aspect, embodiments of the utility model provide a cap subassembly, which comprises:

[0006] a rupture disc; and

[0007] a hole plate, the hole plate comprising a hole plate welding area, and the rupture disc being welded in the hole plate welding area;

[0008] The hole plate welding area is provided with a hollow structure, the hollow structure comprising at least two through holes uniformly distributed along the circumference of the hole plate welding area, and a connecting bridge being arranged between the two through holes, and the connecting bridge being provided with a hole plate notch.

[0009] In some embodiments, the center of the hole plate notch coincides with the center of the connecting bridge.

[0010] In some embodiments, the ratio between the residual wall thickness of the position where the hole plate notch is located and the overall wall thickness of the hole plate is 1 / 12-8 / 15.

[0011] In some embodiments, the wall thickness of the hole plate is 0.15-0.30 mm, and the residual wall thickness of the position where the hole plate notch is located is 0.025-0.08 mm.

[0012] In some embodiments, the center of the hole plate welding area coincides with the center of the hole plate, the diameter of the hole plate welding area is set to 4mm-6mm; and / or, a through hole area is arranged in the hole plate welding area, the through hole is arranged in the through hole area, the center of the through hole area coincides with the center of the hole plate, and the through hole area is arranged in an annular area 2mm-3.5mm away from the center of the hole plate.

[0013] In some embodiments, the hole plate is further provided with a plurality of hole plate pressure relief holes, the plurality of hole plate pressure relief holes are arranged outside the hole plate welding area, and the hole plate pressure relief holes are arranged in a waist-shaped hole.

[0014] In some embodiments, the hole plate is further provided with a plurality of hole plate pressure relief holes, the plurality of hole plate pressure relief holes are arranged outside the hole plate welding area, and the plurality of hole plate pressure relief holes are arranged in a grid shape.

[0015] In some embodiments, the plurality of hole plate pressure relief holes includes a first circle of pressure relief holes and a second circle of pressure relief holes arranged around the first circle of pressure relief holes, and the number of pressure relief holes in each circle is not less than 3.

[0016] In some embodiments, the plurality of hole plate pressure relief holes in the first circle of pressure relief holes and / or the second circle of pressure relief holes are uniformly distributed about the center of the hole plate.

[0017] In some embodiments, the hole plate further includes a plurality of first pressure relief hole connecting bridges and a plurality of second pressure relief hole connecting bridges, each first pressure relief hole connecting bridge connects two adjacent hole plate pressure relief holes in the first circle of pressure relief holes, and each second pressure relief hole connecting bridge connects two adjacent hole plate pressure relief holes in the second circle of pressure relief holes.

[0018] In some embodiments, the distance between the outer edges of the hole plate pressure relief holes and the outer edges of the hole plate is not less than 1mm.

[0019] In a second aspect, embodiments of the utility model provide a battery, the battery includes a shell and a cap assembly connected to one end of the shell, and the cap assembly is arranged as the above cap assembly.

[0020] In a third aspect, embodiments of the utility model provide a battery pack, the battery pack includes a box body and a plurality of batteries arranged in the box body, and the batteries are arranged as the above battery.

[0021] The beneficial effects of embodiments of the utility model are as follows:

[0022] In the embodiment of the utility model, through set up the openwork structure in the hole plate welding area, the openwork structure includes at least two through holes, at least two through holes are connected with a bridge, the hole plate notch is set on the bridge, because the both sides of the bridge are set as the through hole, thus the both sides of hole plate notch are configured as the non closed structure, thereby can weaken the structural strength of hole plate notch itself, make the residual wall of hole plate notch can also break off when under the same pressure effect after the hole plate uses the 3 series aluminum, 5 series aluminum or 7 series aluminum with higher hardness to enhance the structure, thereby keep the stability of battery's anti -explosion pressure threshold. BRIEF DESCRIPTION OF DRAWINGS

[0023] In order to more clearly illustrate the technical scheme in the embodiment of the utility model, the drawings needed in the embodiment description will be briefly introduced, obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can also be obtained according to these drawings without creating labor.

[0024] Figure 1 It is the top view of the hole plate in the related art;

[0025] Figure 2 It is the sectional view of the cap assembly provided by the embodiment one of the utility model;

[0026] Figure 3 It is the top view of the hole plate provided by the embodiment one of the utility model;

[0027] Figure 4 It is the perspective view of the hole plate provided by the embodiment one of the utility model;

[0028] Figure 5 It is the bottom view of the hole plate provided by the embodiment one of the utility model;

[0029] Figure 6 It is the test method diagram of the deformation resistance of the hole plate of the cap assembly provided by the embodiment of the utility model;

[0030] Figure 7 It is the top view of the hole plate provided by the embodiment two of the utility model;

[0031] Figure 8 It is the bottom view of the hole plate provided by the embodiment two of the utility model;

[0032] Related technical drawing reference numeral:

[0033] 6, hole plate;61, hole plate welding area;62, notch;

[0034] The drawing reference numeral of the embodiment of the application:

[0035] 10, cap assembly;

[0036] 1. Top cover; 11. Top cover pressure relief hole;

[0037] 2. Explosion-proof plate; 21. Score; 22. Bossed part;

[0038] 3. Orifice plate gasket; 31. Gasket pressure relief hole; 32. Through hole;

[0039] 4. Orifice plate; 41. Orifice plate pressure relief hole; 411. First ring of pressure relief hole; 412. Second ring of pressure relief hole; 42. Orifice plate notch; 43. Orifice plate welding area; 44. Hollow structure; 45. Through hole; 451. Through hole area; 46. Connecting bridge; 47. Pressure relief hole connecting bridge; 471. First pressure relief hole connecting bridge; 472. Second pressure relief hole connecting bridge;

[0040] 5. Insulating sleeve;

[0041] 7. Test column Detailed Implementation

[0042] 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 scope of protection 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.

[0043] In related technologies, such as Figure 1 As shown, the cap assembly of the cylindrical lithium-ion secondary battery includes a perforated plate 6 and an explosion-proof sheet. The explosion-proof sheet is welded to the welding area 61 of the perforated plate, and a groove 62 is provided in the welding area 61 of the perforated plate. As the internal pressure of the battery increases, the residual wall where the groove 62 of the perforated plate 6 is located breaks, thereby causing the explosion-proof sheet to disconnect from the perforated plate 6.

[0044] In related technologies, the perforated plate is made of 1-series aluminum material. The perforated plate itself has low strength and is therefore easily deformed. During the flipping process of the explosion-proof sheet, the explosion-proof sheet squeezes the perforated plate, causing the plate to deform and then reconnect with the explosion-proof sheet, preventing the internal circuit of the battery from being broken. The applicant found that after changing to 3-series aluminum, the strength of the perforated plate itself can be increased. However, due to the increased strength of the perforated plate, the residual wall thickness at the notch 62 is difficult to break, thus affecting the explosion-proof pressure threshold of the cap assembly.

[0045] In the embodiments of the present application, a cap assembly 10 is provided, as shown in the drawings, which comprises a top cover 1, a rupture disc 2, a hole plate gasket 3, a hole plate 4 and an insulating sleeve 5, wherein the top cover 1, the rupture disc 2, the hole plate gasket 3 and the hole plate 4 are sequentially stacked from top to bottom, the top cover 1, the rupture disc 2, the hole plate gasket 3 and the hole plate 4 are all arranged inside the insulating sleeve 5, the hole plate gasket 3 is arranged between the rupture disc 2 and the hole plate 4, and is used to prevent the hole plate 4 and the rupture disc 2 from being connected except for the welding area. Figures 2 to 4

[0046] The hole plate 4 comprises a hole plate welding area 43, the center of the rupture disc 2 is provided with a boss portion 22 protruding towards the side of the hole plate 4, and the center of the hole plate gasket 3 is provided with a through hole 32, and the boss portion 22 of the rupture disc 2 is welded on the hole plate welding area 43 through the through hole 32.

[0047] The cap assembly 10 comprises an explosion-proof structure, which comprises a plurality of top cover pressure relief holes 11 arranged on the top cover 1, a rupture disc notch 21 arranged on the rupture disc 2, a plurality of gasket pressure relief holes 31 arranged on the hole plate gasket 3, and a plurality of hole plate pressure relief holes 41 arranged on the outer circumferential side of the hole plate welding area 43 of the hole plate 4, wherein the number of the plurality of top cover pressure relief holes 11 can be 3, and the number of the plurality of gasket pressure relief holes 31 can be 2, 3, 4 or 5. The shape of the top cover pressure relief hole 11 and the gasket pressure relief hole 31 can be a waist-shaped hole. Each hole plate pressure relief hole 41 and each gasket pressure relief hole 31 are configured to be at least partially arranged in opposition to each other, the orthographic projection of the rupture disc notch 21 on the hole plate gasket 3 is located in the gasket pressure relief hole 31, and the high-pressure gas flow generated inside the battery sequentially passes through the hole plate pressure relief hole 41 and the gasket pressure relief hole 31 and acts on the rupture disc 2, so that the rupture disc 2 is turned over towards the side close to the top cover 1.

[0048] In the embodiments of the present application, in order to enhance the strength of the hole plate 4, the hole plate 4 is made of 3-series aluminum, 5-series aluminum or 7-series aluminum, as shown in Table 1 below, the hardness HB of the material of the 3-series aluminum, 5-series aluminum and 7-series aluminum increases relative to the 1-series aluminum, thereby increasing the strength of the hole plate 4.

[0049] Table 1 Composition and hardness of different aluminum series materials

[0050] 1-series aluminum 3-series aluminum 5-series aluminum 7-series aluminum Material composition Al Al, Mn Al, Mg Al, Zn Hardness HB 20～30 Slightly greater than 1-series aluminum 40～60 140～150

[0051] According to the data in Table 1, the 3-series aluminum, 5-series aluminum and 7-series aluminum are doped with other metal materials with higher hardness relative to the 1-series aluminum, thereby increasing the strength of the hole plate and improving the anti-deformation ability of the hole plate.

[0052] The applicant found that after using 3-series aluminum, the strength of the hole plate itself can be increased, but the residual wall thickness where the notch 62 is located is difficult to break due to the increase in the strength of the hole plate, thereby affecting the explosion-proof pressure threshold of the cap assembly.​

[0053] As shown in Figure 3 and Figure 4 embodiment of the present application further comprises a hollow structure 44 arranged in the welding area 43 of the hole plate 4, the hollow structure 44 comprises at least two through holes 45, and a connecting bridge 46 is arranged between the two through holes 45, and the hole plate notch 42 is arranged on the connecting bridge 46.

[0054] It can be understood that, in the related art, the notch of the hole plate is arranged in a closed structure, and the residual wall at the position of the notch is also arranged in a closed structure, so that when the strength of the hole plate is increased, the residual wall at the position of the notch will be difficult to break under the same pressure, thereby affecting the stability of the explosion pressure threshold of the battery. In the embodiment of the present application, the hollow structure is arranged in the welding area of the hole plate, the hollow structure comprises at least two through holes, and a connecting bridge is arranged between the two through holes, and the hole plate notch is arranged on the connecting bridge. Since the two sides of the connecting bridge are arranged as through holes, the two sides of the hole plate notch are arranged as non-closed structures, thereby weakening the structural strength of the hole plate notch itself, so that when the hole plate is made of 3-series aluminum, 5-series aluminum or 7-series aluminum with high hardness for structural reinforcement, the residual wall at the position of the hole plate notch can also be broken under the same pressure, thereby maintaining the stability of the explosion pressure threshold of the battery.

[0055] The inventors found through tests that, in the related art, the battery adopts the hole plate structure shown in Figure 1 , and the explosion pressure threshold of the battery is 1.1±0.2Mpa. When the battery adopts the hole plate structure shown in Figure 3 , the explosion pressure threshold of the battery is still 1.1±0.2Mpa.

[0056] In some embodiments, the hollow structure 44 comprises three through holes 45 arranged around the center of the hole plate 4, and three connecting bridges 46 are arranged between the three through holes 45, and a hole plate notch 42 is arranged on each connecting bridge 46. The center of each hole plate notch 42 coincides with the center of the connecting bridge 46. The three through holes 45 are all arranged as waist-shaped holes, and the center lines of the centers of the adjacent two through holes 45 and the center of the hole plate 4 form an included angle of 60°. Correspondingly, the center lines of the centers of the adjacent two connecting bridges 46 and the center of the hole plate 4 also form an included angle of 60°. By arranging the hollow structure 44 of the hole plate 4 as a symmetrical structure, and arranging the center of the hole plate notch 42 to coincide with the center of the connecting bridge 46, the stress of the residual wall at the position of the hole plate notch 42 is uniformly distributed, which is conducive to the breaking of the hole plate notch 42. At the same time, the three hole plate notches 42 are uniformly spaced about the center of the hole plate 4, which is conducive to the simultaneous breaking of the three hole plate notches 42 under the same pressure, thereby forming a break between the explosion-proof sheet and the hole plate.

[0057] In some embodiments, continuing to refer toFigure 3 and Figure 4 The ratio between the residual wall thickness of the portion where the perforated plate notch 42 is located and the overall wall thickness of the perforated plate 4 is 1 / 12-8 / 15, thereby facilitating the simultaneous maintenance of moderate deformation resistance of the perforated plate 4 and stability of the explosion pressure threshold of the battery.

[0058] The overall wall thickness of the perforated plate 4 is understood as the sum of the depth of the perforated plate notch and the residual wall thickness of the portion where the perforated plate notch is located.

[0059] In some embodiments, the overall wall thickness of the perforated plate 4 is 0.15-0.30 mm. The wall thickness of the perforated plate 4 can be 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.20 mm, 0.25 mm, 0.30 mm, or a value between any two of the above values or a range between any two of the above values. Correspondingly, the residual wall thickness of the portion where the perforated plate notch 42 is located is 0.025-0.08 mm. In specific embodiments, the residual wall thickness of the portion where the perforated plate notch 42 is located is 0.025 mm, 0.03 mm, 0.035 mm, 0.04 mm, 0.045 mm, 0.05 mm, 0.052 mm, 0.056 mm, 0.06 mm, 0.062 mm, 0.065 mm, 0.066 mm, 0.07 mm, 0.075 mm, 0.08 mm, and a range between any two of the above values or a value between any two of the above values.

[0060] The inventors used the cap assembly made of the perforated plate structure as shown in Figure 1 as Comparative Example 1, and used the cap assembly made of the perforated plate structure as shown in Figure 3 as Example 1, and tested the deformation resistance force of the cap assembly provided by Comparative Example 1 at the perforated plate and the deformation resistance force of the cap assembly provided by Example 1 at the perforated plate using a universal testing machine.

[0061] The testing method is as follows: as shown in Figure 6 , the planar end of the cylindrical testing column 7 with a diameter of 8 mm of the universal testing machine is used to extrude the perforated plate of the cap assembly, the extrusion speed is 0.1 mm / min, and the stroke is 0.5 mm.

[0062] The test results are as follows: the deformation resistance pressure of the perforated plate of the cap assembly provided by Comparative Example 1 is 99 N, and the deformation resistance pressure of the perforated plate of the cap assembly provided by Example 1 is 117 N.

[0063] It is found through the test that the perforated plate 4 provided by the embodiments of the present application can significantly increase the deformation resistance pressure of the perforated plate, while the stability of the explosion pressure threshold of the cap assembly is also maintained.

[0064] With reference to Figures 2 to 4 , the center of the hole plate welding area 43 is arranged to coincide with the center of the hole plate 4, the hole plate welding area 43 is arranged as a circular welding area, and the diameter of the hole plate welding area 43 is 4mm-6mm. The diameter of the hole plate welding area 43 can be 4mm, 4.5mm, 5mm, 5.5mm, 6mm, or a value between any two of the above values or a range between any two of the above values. The upper surface of the hole plate welding area 43 is used for welding the explosion-proof sheet 2, and the lower surface of the hole plate welding area 43 is used for welding the tab of the battery tab. It can be understood that if the diameter of the hole plate welding area 43 is less than 4mm, the welding force of the hole plate and the explosion-proof sheet will not be enough, or the hole plate welding area will be difficult to weld all the tabs of the tab. If the diameter of the hole plate welding area 43 is greater than 6mm, the hole plate welding area will occupy too much of the hole plate itself, thereby affecting the arrangement of the hole plate relief hole. In a specific implementation, the outer diameter of the hole plate 4 is arranged to be 14mm, and the diameter of the hole plate welding area 43 is arranged to be 5mm.

[0065] A through hole area 451 is arranged in the hole plate welding area 43, and the through hole 45 is arranged in the through hole area 451. The through hole area 451 is an annular area as shown by the dashed line in Figure 3 , the center of the through hole area 451 coincides with the center of the hole plate 4, and the through hole area 451 is arranged in an annular area 2-3.5mm from the center of the hole plate 4. It can be understood that the explosion-proof sheet 2 is mainly welded to the area inside the through hole area 451, and if the annular area where the through hole area 451 is located is arranged to be less than 2mm from the center of the hole plate 4, the welding force of the explosion-proof sheet 2 and the hole plate 4 will be affected. If the annular area where the through hole area 451 is located is arranged to be greater than 3.5mm from the center of the hole plate 4, the structural strength of the hole plate welding area 43 will be affected.

[0066] In some embodiments, with reference to Figures 3 to 5 , the plurality of hole plate relief holes 41 are located outside the hole plate welding area 43, and a relief hole connecting bridge 47 is connected between two adjacent hole plate relief holes 41. The area where the plurality of hole plate relief holes 41 are located is arranged as an annular area, and when the size of the hole plate 4 is fixed, the cross-sectional area of the relief hole annular area where the plurality of hole plate relief holes 41 are located remains fixed. The cross-sectional area of the relief hole annular area = the cross-sectional area of the plurality of hole plate relief holes + the cross-sectional area of the plurality of relief hole connecting bridges 47. When the cross-section of the plurality of relief hole connecting bridges 47 is larger, correspondingly, the strength of the relief hole annular area is higher, thereby making the strength of the hole plate 4 higher, thereby facilitating the improvement of the anti-deformation ability of the hole plate 4. Conversely, the larger the cross-section of the plurality of relief hole connecting bridges 47, the smaller the cross-sectional area of the plurality of hole plate relief holes 41, thereby weakening the relief capacity of the hole plate 4.

[0067] In an embodiment provided in the present application, with reference toFigures 3 to 5 The orifice plate 4 is made of 3-series aluminum, 5-series aluminum or 7-series aluminum with higher material strength, and the number of orifice plate relief holes 41 is set to 3, 4 or 5, respectively. The orifice plate relief holes 41 are set as waist-shaped holes.

[0068] In another embodiment provided in the present application, referring to Figure 7 and Figure 8 The orifice plate 4 is made of 1-series aluminum, and the plurality of orifice plate relief holes 41 are set in a grid shape. The plurality of orifice plate relief holes 41 are set in multiple circles, and the number of orifice plate relief holes in each circle is the same, and the number of orifice plate relief holes in each circle is not less than 3, as shown in Figure 7 , the number of orifice plate relief holes in each circle is 8. The shape of each orifice plate relief hole can be trapezoidal, annular, sector-shaped, circular or square.

[0069] Compared with the orifice plate structure shown in Figure 3 of the above embodiment, the orifice plate structure shown in Figure 6 of the present embodiment, the cross-sectional area of each orifice plate relief hole 41 is reduced, and the cross-sectional area of the plurality of relief hole connecting bridges 47 is increased, thereby facilitating the enhancement of the structural strength of the orifice plate 4 and the improvement of the orifice plate deformation resistance.

[0070] The multiple circles of orifice plate relief holes include adjacent first circle of orifice plate relief holes 411 and second circle of orifice plate relief holes 412, the second circle of orifice plate relief holes 412 is arranged around the first circle of orifice plate relief holes 411, and the number of orifice plate relief holes in each circle is the same. The first circle of orifice plate relief holes 411 includes a first relief hole connecting bridge 471 connecting adjacent two orifice plate relief holes, and the second circle of orifice plate relief holes 412 includes a second relief hole connecting bridge 472 connecting adjacent two orifice plate relief holes 41, wherein the orifice plate relief holes 41 of the first circle of orifice plate relief holes 411 correspond to the orifice plate relief holes 41 of the second circle of orifice plate relief holes 412 one by one, and the first relief hole connecting bridge 471 and the second relief hole connecting bridge 472 are connected. It can be understood that the orifice plate relief holes 41 of the first circle of orifice plate relief holes 411 are closer to the center of the orifice plate 4 than the orifice plate relief holes 412 of the second circle of orifice plate relief holes 412, and correspondingly, the size of the holes of the first circle of orifice plate relief holes 411 is smaller than the size of the holes of the second circle of orifice plate relief holes 412.

[0071] By connecting the first relief hole connecting bridge 471 to the second relief hole connecting bridge 472, the structural strength of the relief hole connecting bridge is enhanced, thereby enhancing the structural strength of the orifice plate 4.

[0072] In some embodiments, the plurality of hole plate pressure relief holes 41 are arranged outside the hole plate welding area 43, and the distance between the outer edges of the plurality of hole plate pressure relief holes 41 and the outer edges of the hole plate 4 is not less than 1mm. It can be understood that if the distance between the outer edges of the plurality of hole plate pressure relief holes 41 and the outer edges of the hole plate 4 is greater than 1mm, it will cause the hole plate 4 to be difficult to process. In a specific embodiment, the diameter of the hole plate 4 is 14mm, the diameter of the hole plate welding area 43 is 5mm, and the plurality of hole plate pressure relief holes 41 are arranged in an annular area 5-13mm away from the center of the hole plate.

[0073] Embodiments of the present application also provide a battery, which can be a cylindrical lithium ion battery or a cylindrical nickel-hydrogen battery. The battery comprises a shell and a cap assembly, which can be the cap assembly provided by the above embodiments.

[0074] Embodiments of the present application also provide a battery pack, which can be a power battery pack or an energy storage battery pack. The battery pack comprises a box body and a plurality of batteries accommodated in the box body, and the batteries comprise the batteries provided by the above embodiments.

[0075] The above has carried on the detailed introduction to the embodiment of the utility model, the principle and implementation mode of the utility model have been described in this paper by applying specific examples, the above embodiment explanation is only for helping to understand the method and core idea of the utility model; At the same time, for the skilled in the art, according to the idea of the utility model, there will be changes in specific implementation mode and application range, and the above-mentioned, the content of the specification should not be understood as the limitation of the utility model.

Claims

1. A cap assembly, characterized in that, include: Explosion-proof sheet; as well as An orifice plate, the orifice plate including an orifice plate welding area, wherein the explosion-proof sheet is welded to the orifice plate welding area; The orifice plate welding area is provided with a hollow structure, the hollow structure including at least two through holes evenly distributed along the circumference of the orifice plate welding area, a connecting bridge between the two through holes, and the connecting bridge having orifice plate grooves.

2. The cap assembly according to claim 1, characterized in that, The center of the perforated plate groove coincides with the center of the connecting bridge.

3. The cap assembly according to claim 2, characterized in that, The ratio between the residual wall thickness at the location of the perforated plate groove and the overall wall thickness of the perforated plate is 1 / 12 to 8 / 15.

4. The cap assembly according to claim 3, characterized in that, The overall wall thickness of the perforated plate is 0.15mm to 0.30mm, and the residual wall thickness at the location of the perforated plate groove is 0.025mm to 0.08mm.

5. The cap assembly according to claim 1, characterized in that, The center of the orifice plate welding area coincides with the center of the orifice plate, and the diameter of the orifice plate welding area is set to 4mm to 6mm; and / or, the orifice plate welding area is provided with a through hole area, the through hole is set in the through hole area, the center of the through hole area coincides with the center of the orifice plate, and the through hole area is set in an annular area 2mm to 3.5mm away from the center of the orifice plate.

6. The cap assembly according to any one of claims 1-5, characterized in that, The orifice plate is also provided with a plurality of orifice plate pressure relief holes, which are located on the outside of the welding area of ​​the orifice plate. The orifice plate pressure relief holes are configured as waist-shaped holes, and the number of the plurality of orifice plate pressure relief holes is 3 to 5.

7. The cap assembly according to any one of claims 1-5, characterized in that, The orifice plate is also provided with a plurality of orifice plate pressure relief holes, which are located on the outside of the welding area of ​​the orifice plate and are arranged in a grid pattern.

8. The cap assembly according to claim 7, characterized in that, The plurality of orifice plate pressure relief holes include a first ring of pressure relief holes and a second ring of pressure relief holes arranged around the first ring of pressure relief holes, with each ring containing no less than 3 pressure relief holes.

9. The cap assembly according to claim 8, characterized in that, The pressure relief holes in the first ring and / or the second ring are evenly distributed about the center of the orifice plate.

10. The cap assembly according to claim 8, characterized in that, The orifice plate also includes a plurality of first pressure relief hole bridges and a plurality of second pressure relief hole bridges. Each first pressure relief hole bridge connects to two adjacent pressure relief holes in the first ring of pressure relief holes. Each second pressure relief hole bridge connects to two adjacent pressure relief holes in the second ring of pressure relief holes. The second pressure relief hole bridge is connected to the second pressure relief hole bridge.

11. The cap assembly according to any one of claims 1-5, characterized in that, The distance between the outer edge of the pressure relief hole of the orifice plate and the outer edge of the orifice plate is set to be no less than 1 mm.

12. A battery, characterized in that, The battery includes a housing and a cap assembly connected to one end of the housing, the cap assembly being configured as the cap assembly according to any one of claims 1-11.

13. A battery pack, characterized in that, The battery pack includes a housing and a plurality of batteries disposed within the housing, wherein the batteries are configured as described in claim 12.

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