Cap assembly, battery and battery pack

Abstract

The utility model discloses a cap assembly, a battery and a battery pack, the battery comprises a top cover, an anti-explosion sheet, a pore plate gasket and a pore plate which are sequentially arranged from top to bottom, and a first pressure relief hole is formed in the top cover; wherein the anti-explosion piece comprises a first body, a first inclined part and a second body which are sequentially connected in the radial direction of the anti-explosion piece, the first body is attached to the top cover, the second body is located on the side, away from the top cover, of the first body, and in the thickness direction of the anti-explosion piece, the projection of the first pressure relief hole is located in the first inclined part and the second body. The first inclined part and the second body are spaced from the top cover by a certain distance, the projection of the first pressure relief hole is in the first inclined part and the second body, the first inclined part and the second inclined part do not shield the pressure relief area of the first pressure relief hole, and an existing anti-explosion piece shields the exhaust area of the pressure relief hole of the top cover. And the area of the first pressure relief hole can be properly increased, the exhaust effect of the top cover is improved, and the reliability of the battery is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of batteries, and particularly relates to a cap assembly, a battery and a battery pack. BACKGROUND

[0002] Lithium ion batteries have the advantages of high energy density, fast charging and discharging, long cycle life, no pollution and the like, and have been widely applied in the fields of portable electronic devices, communication, energy storage and electric vehicles.

[0003] The cylindrical battery comprises a cap structure, a shell and a battery cell and the like. The cap structure comprises a top cover, a sealing element, a burst disc and the like. The top cover is provided with a pressure relief hole structure. In order to avoid the burst disc shielding the exhaust area of the pressure relief hole on the top cover, the area of the pressure relief hole on the top cover is designed to be small, which affects the exhaust effect. CONTENT OF THE UTILITY MODEL

[0004] The cap assembly, the battery and the battery pack provided by the embodiments of the application solve the problem that the existing burst disc shields the exhaust area of the pressure relief hole of the top cover.

[0005] In a first aspect, the embodiments of the application provide a cap assembly, comprising:

[0006] A top cover, a burst disc, a hole plate gasket and a hole plate are sequentially arranged from top to bottom, and a first pressure relief hole is arranged on the top cover.

[0007] The burst disc comprises a first body, a first inclined portion and a second body which are sequentially connected in a radial direction of the burst disc, the first body is attached to the top cover, the second body is located on a side of the first body away from the top cover, and a projection of the first pressure relief hole is located in the first inclined portion and the second body in a thickness direction of the burst disc.

[0008] Optionally, the first inclined portion comprises a starting end and a terminal end, the starting end is closer to the first body than the terminal end, and the starting end is located between an inner wall of the first pressure relief hole on the top cover close to an edge of the top cover and the edge of the top cover.

[0009] Optionally, a second pressure relief hole is arranged on the hole plate, and the terminal end is located between an inner wall of the second pressure relief hole on the hole plate close to an edge of the hole plate and the edge of the hole plate.

[0010] Optionally, a diameter of a circle in which the terminal end is located is S2, wherein,

[0011] S2=S3+2a,

[0012] S3 is an outer diameter of the second pressure relief hole.

[0013] a is a constant of the punched edge width on the orifice plate, a is in the range of.

[0014] Optionally, 7.7mm≤S3≤9.8mm, 0.3mm≤a≤0.5mm.

[0015] Optionally, the first inclined portion comprises a starting end and a terminal end, the starting end is closer to the first body than the terminal end, a diameter of a circle where the starting end is located is S1,

[0016] 11mm≤S1≤12mm.

[0017] Optionally, a diameter of a circle where the terminal end is located is S2, 8.3mm≤S2≤10.8mm.

[0018] Optionally, 0.15mm≤N1≤0.3mm.

[0019] Optionally, the orifice plate gasket is provided with a second inclined portion, the second inclined portion is connected with the first inclined portion.

[0020] Optionally, the orifice plate is provided with a third inclined portion, the third inclined portion is connected with the second inclined portion.

[0021] In a second aspect, the embodiments of the present application further provide a battery comprising the cap assembly.

[0022] In a third aspect, the embodiments of the present application further provide a battery pack comprising the battery.

[0023] The cap assembly, the battery and the battery pack provided by the embodiments of the present application, the top cap assembly comprises a top cap, a rupture disc, an orifice plate gasket and an orifice plate, the top cap is provided with a first pressure relief hole, the rupture disc comprises a first body, a first inclined portion and a second body, wherein the first body is connected with the top cap, the first inclined portion is arranged from the first body to the second body, the first inclined portion and the second body are spaced apart from the top cap, a projection of the first pressure relief hole is in the first inclined portion and the second body, the first inclined portion and the second inclined portion do not shield the pressure relief area of the first pressure relief hole, the problem that the existing rupture disc shields the exhaust area of the pressure relief hole of the top cap can be solved, the area of the first pressure relief hole can be appropriately increased, the exhaust effect of the top cap is improved, and the reliability of the battery is improved. BRIEF DESCRIPTION OF DRAWINGS

[0024] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings needed to be used in the embodiment description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0025] For a more complete understanding of the present application and its advantages, reference is now made to the following description taken in conjunction with the accompanying drawings in which like reference numerals refer to like parts throughout the several figures.

[0026] Figure 1 A side view of a battery provided by an embodiment of the present application.

[0027] Figure 2 A side view of a battery provided by an embodiment of the present application. Figure 1 A cross-sectional view of A-A in the middle.

[0028] Figure 3 A side view of a battery provided by an embodiment of the present application. Figure 2 An enlarged view of a part at B in the middle.

[0029] Figure 4 A side view of a battery provided by an embodiment of the present application. Figure 3 An enlarged view of a part at C in the middle.

[0030] Figure 5 A perspective view of a top cover provided by an embodiment of the present application.

[0031] Figure 6 A cross-sectional view of an assembled cap assembly provided by an embodiment of the present application.

[0032] Figure 7 A labeled view of a rupture disc provided by an embodiment of the present application.

[0033] Figure 8 A labeled view of a partial structure of a battery provided by an embodiment of the present application.

[0034] Figure 9 A cross-sectional view of an assembled cap assembly provided by an embodiment of the present application.

[0035] The reference numerals in the drawings are as follows:

[0036] 1, battery; 10, cap assembly; 20, shell; 21, necked-down structure; 22, flange; 30, battery cell;

[0037] 100, sealing structure; 110, sealing inner cavity; 120, annular body; 121, second sealing protrusion; 130, support table; 131, first sealing protrusion; 140, bottom support;

[0038] 200, top cover; 210, first cover body; 220, second cover body; 230, first pressure relief hole; 240, connecting portion;

[0039] 300, rupture disc; 310, first body; 320, second body; 330, third body; 340, first inclined portion; 341, starting end; 342, ending end; 350, first vertical plate;

[0040] 400, hole plate gasket; 410, second inclined portion;

[0041] 500, hole plate; 510, second pressure relief hole; 520, third inclined portion. DETAILED DESCRIPTION

[0042] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by a person of ordinary skill in the art without creative work fall within the protection scope of the present application.

[0043] Referring to Figure 1 , Figure 2 , Figure 3 and Figure 4 , the present embodiment provides a cap assembly 10 applied to a battery, such as a cylindrical battery. The battery 1 comprises the cap assembly 10, a shell 20 and an electrode core 30. The shell 20 is open at one end, the electrode core 30 is installed in the shell 20, the cap assembly 10 is sealingly connected with the shell 20, and the cap assembly 10 blocks the opening. The shell 20 comprises a necked structure 21 and a flange 22. The end of the shell 20 extends inwardly along the radial direction of the shell 20 to form the flange 22. The flange 22 is in the shape of a ring. The necked structure 21 is formed by concave inwardly along the radial direction of the shell 20 at a position of the shell 20 away from the flange 22 by a certain distance.

[0044] In the present embodiment, referring to Figure 3 and Figure 4 , the cap assembly 10 comprises, from top to bottom, a top cover 200, a rupture disc 300, a hole plate gasket 400 and a hole plate 500. In some embodiments, the cap assembly 10 further comprises a sealing structure 100, which has a sealing inner cavity 110, and the top cover 200, the rupture disc 300, the hole plate gasket 400 and the hole plate 500 are installed in the sealing inner cavity 110. The cap assembly 10 is fixed between the necked structure 21 and the flange 22. The sealing structure 100 is attached to the necked structure 21, the flange 22 and the part of the shell 20 between the necked structure 21 and the flange 22. The necked structure 21 and the flange 22 press the sealing structure 100 along the axial direction of the shell 20, so that the sealing structure 100 is sealingly connected with the top cover 200 and the rupture disc 300.

[0045] In the present embodiment, referring to Figure 7, the explosion-proof sheet 300 includes a first body 310, a first inclined portion 340, a second body 320 and a third body 330 connected in sequence along the radial direction of the explosion-proof sheet 300. In the thickness direction of the explosion-proof sheet 300, the first body 310, the first inclined portion 340 and the second body 320 are sequentially away from the top cover 200. The first body 310 is attached to the top cover 200. The second body 320 is provided with explosion-proof marks. The top cover 200 is provided with a first pressure relief hole 230, and the projection of the first pressure relief hole 230 is located in the first inclined portion 340 and the second body 320 along the axial direction of the battery 1.

[0046] Compared with the related art, the first body 310 and the second body 320 are vertically connected, and the first body 310 can cover a part of the first pressure relief hole 230, affecting the pressure relief effect. In the embodiment of the application, the first inclined portion 340 connects the first body 310 and the second body 320, the first inclined portion 340 and the second body 320 are spaced apart from the top cover 200, the projection of the first pressure relief hole 230 is in the first inclined portion 340 and the second body 320, the first inclined portion 340 and the second body 320 do not block the pressure relief area of the first pressure relief hole 230, the existing explosion-proof sheet blocks the exhaust area of the top cover pressure relief hole, and the area of the first pressure relief hole 230 can be appropriately increased, the exhaust effect of the top cover 200 is increased, and the reliability of the battery is improved.

[0047] In some embodiments, referring to Figure 7 , the first inclined portion 340 includes a starting end 341 and an ending end 342, and the starting end 341 is closer to the first body 310 than the ending end 342. The starting end 341 is located between the inner wall of the first pressure relief hole 230 close to the edge of the top cover 200 and the edge of the top cover 200.

[0048] In the embodiment of the application, the position of the starting end 341 of the first inclined portion 340 is set between the outer edge of the first pressure relief hole 230 and the outer edge of the top cover 200, so that the first inclined portion 340 avoids the first pressure relief hole 230 and ensures the pressure relief effect.

[0049] In some embodiments, referring to Figure 4 , the hole plate 500 is provided with a second pressure relief hole 510, and the ending end 342 is located between the inner wall of the second pressure relief hole 510 close to the edge of the hole plate gasket 400 and the edge of the hole plate 500.

[0050] In the embodiment of the application, the position of the ending end 342 of the first inclined portion 340 is set between the outer edge of the second pressure relief hole 510 and the outer edge of the hole plate 500, so that the first inclined portion 340 avoids covering the second pressure relief hole 510, ensures the exhaust effect of the hole plate 500, ensures the pressure relief effect, and improves the reliability of the battery.

[0051] In some embodiments, referring toFigure 6 and Figure 7 The diameter of the circle where the terminal end 342 is located is S2, wherein S2 satisfies formula (1):

[0052] S2 = S3 + 2a (1);

[0053] S3 is the outer diameter of the second pressure relief hole 510;

[0054] a is the stamping edge width constant of the hole plate 500, and a is in the range of

[0055] In this embodiment, the stamping edge width constant of the hole plate 500 refers to the distance between the outer edge of the second pressure relief hole 510 and the inner edge of the third inclined portion 520 on the hole plate 500.

[0056] In this embodiment, the position of the terminal end 342 is determined according to formula (1), so as to avoid covering the second pressure relief hole 510 by the terminal end 342, and to ensure the pressure relief effect of the hole plate 500. In the case where the specifications of the hole plate 500 are unchanged, the position of the terminal end 342 is determined according to formula (1), which facilitates the design of the rupture disc 300.

[0057] In some embodiments, 7.7mm≤S3≤9.8mm, 0.3mm≤a≤0.5mm.

[0058] In this embodiment, the value of S3 is 7.7mm, 7.9mm, 8.2mm, 8.5mm, 8.9mm, 9.1mm, 9.5mm, 9.8mm or other values not listed. If the value of S3 is less than 7.7mm, the hole diameter of the second pressure relief hole 510 is too small to meet the exhaust requirement, and if the value of S3 is greater than 9.8mm, the hole diameter of the second pressure relief hole 510 is too large to affect the structural strength of the hole plate 500. The parameter design of S3 can meet the specification requirements of the second pressure relief hole 510 on the hole plate 500, ensure the pressure relief effect, and meet the structural strength requirements of the hole plate 500.

[0059] In this embodiment, the value of a is 0.3mm, 0.4mm, 0.5mm or other values not listed. The value of a is determined by the machining precision.

[0060] In some embodiments, referring to Figure 6 The first inclined portion 340 includes a starting end 341 and a terminal end 342, the starting end 341 is closer to the first body 310 than the terminal end 342, the diameter of the circle where the starting end 341 is located is S1, and 11mm≤S1≤12mm. The value of S1 can be 11mm, 11.3mm, 11.5mm, 11.6mm, 11.8mm, 12mm or other values not listed.

[0061] In the embodiments of the present application, the diameter of the explosion-proof sheet 300 is adapted to the shell 20, the size of the explosion-proof sheet 300 is fixed, the size of the first body 310 is indirectly determined by limiting the diameter of the circle where the starting end 341 is located, which is convenient for product design. When the size of S1 is less than 11 mm, in order to avoid that the explosion-proof sheet 300 blocks the first pressure relief hole 230, it is necessary to reduce the size of the first pressure relief hole 230, which affects the exhaust effect. If the size of S1 is greater than 12 mm, the size of the first body 310 is reduced, the fitting area of the first body 310 and the top cover 200 is reduced, which affects the assembly relationship of the first body 310 and other components.

[0062] In some embodiments, referring to Figure 6 and Figure 7 , the diameter of the circle where the terminal end 342 is located is S2, and 8.3 mm≤S2≤10.8 mm. Among them, the value of S2 can be 8.4 mm, 8.5 mm, 8.7 mm, 8.9 mm, 9.2 mm, 9.5 mm, 9.7 mm, 9.9 mm, 10.2 mm, 10.5 mm, 10.8 mm or other values not listed.

[0063] In the embodiments, if the value of the terminal end 342 is small, it is not conducive to the processing and forming of the first inclined part 340, and if the value of the terminal end 342 is large, it will cover the second pressure relief hole 510, affecting the pressure relief effect. In the embodiments of the present application, the diameter range of the circle where the terminal end 342 is located is reasonably designed.

[0064] In some embodiments, referring to Figure 7 In some embodiments, 0.15 mm≤N1≤0.3 mm. Among them, the value of N1 is 0.15 mm, 0.18 mm, 0.19 mm mm, 0.22 mm mm, 0.25 mm mm, 0.28 mm, 0.3 mm or other values not listed.

[0065] For example, the included angle between the first inclined part 340 and the plane where the second body 320 is located is β, which satisfies formula (2):

[0066] β=180°-arctan[N1 / S1-S2] (2),

[0067] Among them, N1 is the distance between the lower surface of the first body 310 and the lower surface of the second body 320;

[0068] S1 is the diameter of the circle where the starting end 341 of the first inclined part 340 is located;

[0069] S2 is the diameter of the circle where the terminal end 342 of the first inclined part 340 is located.

[0070] In the embodiment of the present application, when the distance between the starting end 341 and the ending end 342 of the first inclined portion 340 and the lower surface of the second body 320 is determined, the inclination angle of the first inclined portion 340 can be determined. The distance between the lower surface of the first body 310 and the lower surface of the second body 320 is designed to meet the requirements of the explosion-proof sheet 300 in terms of the height of the explosion-proof sheet 300 after explosion and the material stretching requirement of the first inclined portion 340.

[0071] In some embodiments, the orifice plate gasket 400 is provided with a second inclined portion 410, which is connected to the first inclined portion 340.

[0072] In the embodiment of the present application, referring to Figure 4 , the orifice plate gasket 400 is attached to the side of the explosion-proof sheet 300 away from the top cover 200, and the shape of the orifice plate gasket 400 is adapted to the shape of the explosion-proof sheet 300. The second inclined portion 410 is connected to the first inclined portion 340, thereby ensuring the overall height of the cap assembly 10.

[0073] In some embodiments, referring to Figure 4 , the orifice plate 500 is provided with a third inclined portion 520, which is connected to the second inclined portion 410.

[0074] In the embodiment of the present application, the orifice plate 500 and the explosion-proof sheet 300 are welded and fixed, and the orifice plate 500 and the explosion-proof sheet 300 clamp and fix the orifice plate gasket 400. The first inclined portion 340, the second inclined portion 410 and the third inclined portion 520 are connected in sequence, and the explosion-proof sheet 300, the orifice plate gasket 400 and the orifice plate 500 are closely attached, thereby occupying a small height space and ensuring the overall height of the cap assembly 10.

[0075] In some embodiments, the explosion-proof sheet 300 further includes a third body 330, which is located on the side of the second body 320 away from the first body 310. The first body 310 and the second body 320 are annular structures, and the third body 330 is circular. The third body 330 is farther away from the top cover 200 than the second body 320. The side of the third body 330 away from the top cover 200 is welded to the orifice plate 500.

[0076] In the embodiment of the present application, the first body 310, the second body 320 and the third body 330 of the explosion-proof sheet 300 are located at different heights, thereby increasing the material of the explosion-proof sheet 300 and providing the material required for the explosion-proof sheet 300 to be turned over, and ensuring the turning height of the explosion-proof sheet 300 after explosion.

[0077] In the embodiment of the present application, referring to Figure 4The explosion-proof sheet 300 includes a first vertical plate 350 located at an edge of the explosion-proof sheet 300. The first vertical plate 350 extends to the side of the top cover 200, and an inner side of the first vertical plate 350 is attached to a side of the top cover 200. An outer side of the first vertical plate 350 is sealed to the sealing structure 100. An end surface of the first vertical plate 350 is located at a plane lower than a plane where a surface of the top cover 200 faces away from the explosion-proof sheet 300, that is, the end surface of the first vertical plate 350 is spaced apart from an upper surface of the top cover 200 by a certain distance. The sealing structure 100 includes a second sealing protrusion 121 that is in abutment and sealing with the end surface of the first vertical plate 350 and the side of the top cover 200.

[0078] In the embodiments of the present application, referring to Figure 8 , a gap is formed between the first vertical plate 350 and the top cover 200, and the second sealing protrusion 121 fills the gap. Even if the battery is subjected to external forces such as impact and jolt, the second sealing protrusion 121 is always filled in the gap, ensuring the sealing performance of the battery and improving the reliability of the battery.

[0079] In some embodiments, referring to Figure 6 , the maximum distance between the top cover 200 and the explosion-proof sheet 300 is H, and 1.35mm≤H<2.2mm. The value of D can be 1.35mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or other values not listed. The maximum distance between the top cover 200 and the explosion-proof sheet 300 refers to the maximum distance between a side of the top cover 200 close to the explosion-proof sheet 300 and a side of the explosion-proof sheet 300 close to the top cover 200 along the battery axial direction.

[0080] In the embodiments of the present application, the size design of the maximum distance D between the top cover 200 and the explosion-proof sheet 300 can meet the space required for the explosion-proof sheet 300 to shrink and flip up after explosion, and the height of the cap assembly 10 is reduced as much as possible. In the case of a certain height of the battery, the smaller the height of the cap assembly 10, the larger the space available for the battery cell 30, which is beneficial to improve the battery capacity.

[0081] In some embodiments, referring to Figure 6 , the height of the top cover 200 is H1, and 1.5mm≤H1≤2.05mm. The height of the top cover 200 refers to the distance between two parallel planes virtually abutting the two sides of the top cover 200. The value of H1 can be 1.5mm, 1.6mm, 1.75mm, 1.7mm, 1.9mm, 2.0mm, 2.05mm or other values not listed.

[0082] In the embodiment of the present application, the height of the cap assembly 10 is reduced by reducing the height of the top cover 200, so as to increase the space available for the battery cell 30. The size of the top cover 200 is designed to meet the space required for the explosion-proof disc 300 to flip up after explosion and the assembly requirement of the cap assembly 10.

[0083] In some embodiments, referring to Figure 5 , the top cover 200 includes a first cover body 210 and a second cover body 220 connected in sequence along the radial direction of the top cover 200. The first cover body 210 is annular, and the first cover body 210 is attached to the explosion-proof disc 300. The second cover body 220 is located on the inner side of the first cover body 210, and the second cover body 220 is circular. The second cover body 220 protrudes away from the side of the explosion-proof disc 300. The second sealing protrusion 121 is sealed and abuts against the side of the first cover body 210 away from the second cover body 220. In the embodiment, the first cover body 210 and the second cover body 220 can be integrally formed by stamping. The height of the top cover 200 refers to the distance between the plane where the side of the first cover body 210 attached to the explosion-proof disc 300 is located and the plane where the side of the second cover body 220 away from the explosion-proof disc 300 is located.

[0084] In some embodiments, referring to Figure 8 , the diameter of the sealing position between the second sealing protrusion 121 and the top cover 200 is R1, and the inner diameter of the buckle edge 22 is R2, and 1mm≤R1-R2≤1.7mm. The value of R1-R2 can be 1mm, 1.2mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm or other values not listed.

[0085] In the embodiment of the present application, the outermost edge of the second sealing protrusion 121 is sealingly connected to the side of the top cover 200. The buckle edge 22 holds the sealing structure 100, so as to sealingly connect the sealing structure 100 to the top cover 200 and the explosion-proof disc 300. If R2

[0086] In some embodiments, referring to Figure 9 , the sealing structure 100 further includes a first sealing protrusion 131, which abuts and seals against the side of the explosion-proof disc 300 away from the top cover 200.

[0087] In the embodiment of the present application, the first sealing protrusion 131 and the second sealing protrusion 121 jointly seal the explosion-proof sheet 300 and the top cover 200, so as to realize double sealing of the cap assembly 10, and the sealing effect is good and the reliability is high.

[0088] In some embodiments, referring to Figure 9 , the sealing structure 100 further comprises an annular body 120, a supporting platform 130 and a bottom support 140.

[0089] In the embodiment of the present application, the annular body 120 is in a cylindrical structure, and the second sealing protrusion 121 is arranged on the inner side wall of the annular body 120. The annular body 120 is sealingly connected with the buckle edge 22. The buckle edge 22 and the necked structure 21 jointly press and hold the sealing structure 100 to adapt to the shape of the shell 20 between the buckle edge 22 and the necked structure 21. The supporting platform 130 is arranged at one end of the annular body 120 away from the buckle edge 22, and the supporting platform 130 is connected with the annular body 120. The supporting platform 130 is sealingly attached to the side of the explosion-proof sheet 300 away from the top cover 200. The first sealing protrusion 131 is arranged on the supporting platform 130, and the side of the supporting platform 130 away from the explosion-proof sheet 300 is sealingly connected with the necked structure 21. The bottom support 140 extends along the radial direction of the annular body 120, and the bottom support 140 is connected with the side of the supporting platform 130 away from the annular body 120, and the bottom support 140 is located between the hole plate 500 and the battery cell 30. The annular body 120, the supporting platform 130 and the bottom support 140 enclose the sealed inner cavity 110. In some embodiments, the annular body 120, the supporting platform 130 and the bottom support 140 are integrally formed by injection molding process, and the processing is simple.

[0090] In some embodiments, when the sealing structure 100 is in an assembled state, the compaction density of the first sealing protrusion 131 on the supporting platform 130 is greater than the compaction density of other positions on the supporting platform 130. The compaction density refers to the material density of the supporting platform 130 at all positions when the sealing structure 100 is in a squeezed state. After the sealing structure 100 is assembled, the sealing structure 100 is squeezed, and the first sealing protrusion 131 is squeezed to be flush with the surface of the supporting platform 130. The supporting platform 130 at the first sealing protrusion 131 is subjected to a greater squeezing force, and the material is deformed after being squeezed. Therefore, the compaction density of the supporting platform 130 at the first sealing protrusion 131 is greater than the compaction density of other positions, so as to improve the sealing effect.

[0091] In some embodiments, the compacted density of the annular body 120 at the second sealing protrusion 121 is greater than the compacted density of the annular body 120 at other positions when the sealing structure 100 is in the assembled state. The compacted density refers to the density of the material at different positions of the annular body 120 when the sealing structure 100 is in the extruded state. After the sealing structure 100 is assembled, it is in the extruded state, and the second sealing protrusion 121 is extruded flush with the inner side of the annular body 120. The annular body 120 at the second sealing protrusion 121 is subjected to a greater extrusion force, and the material deforms greatly, so the compacted density of the annular body 120 at the second sealing protrusion 121 is greater than the compacted density at other positions, thereby improving the sealing effect.

[0092] In some embodiments, referring to Figure 9 , the cross-sectional shape of the second sealing protrusion 121 is triangular, trapezoidal, rectangular, arc-shaped, or the like along the axial direction of the sealing structure 100 before the sealing structure 100 is assembled. Before the sealing structure 100 is assembled, the second sealing protrusion 121 satisfies at least one of the following conditions:

[0093] (1) The width of the second sealing protrusion 121 is L1, and 0 < L1 ≤ 1.2 mm. The value of L1 can be 0.2 mm, 0.4 mm, 0.5 mm, 0.7 mm, 0.9 mm, 1.2 mm, or other values not listed. The width of the second sealing protrusion 121 refers to the distance between the two ends of the second sealing protrusion 121 connected to the annular body 120 along the axial direction of the annular body 120. For example, the distance between the end of the second sealing protrusion 121 close to the support 130 and the support 130 is L11, and the distance between the end of the second sealing protrusion 121 away from the support 130 and the support 130 is L12, where 0.6 mm ≤ L11 < 1.2 mm and 1.2 mm ≤ L12 ≤ 1.8 mm. The value of L11 can be 0.6 mm, 0.7 mm, 0.9 mm, 1.1 mm, or other values not listed. The value of L12 can be 1.2 mm, 1.4 mm, 1.6 mm, 1.7 mm, 1.8 mm, or other values not listed.

[0094] (2) The distance between the second sealing protrusion 121 and the support 130 is L2, and 0.8 mm ≤ L2 ≤ 1.4 mm. The value of L2 can be 0.8 mm, 0.9 mm, 1.1 mm, 1.2 mm, 1.4 mm, or other values not listed. The distance between the second sealing protrusion 121 and the support 130 refers to the distance between the second sealing protrusion 121 and the inner wall of the support 130 at the highest position of the annular body 120. For example, when the cross-sectional shape of the second sealing protrusion 121 is triangular, L2 is the distance between the point of the triangle away from the support 130 and the inside of the support 130.

[0095] (3) The height of the second sealing protrusion 121 protruding from the inner wall of the annular body 120 is L3, and 0.10 mm≤L3≤0.25 mm. The value of L3 can be 0.10 mm, 0.13 mm, 0.15 mm, 0.17 mm, 0.18 mm, 0.20 mm, 0.21 mm, 0.23 mm, 0.24 mm, or other values not listed. The width of the second sealing protrusion 121 refers to the distance between the plane virtually abutting the side of the second sealing protrusion 121 away from the annular body 120 and the plane virtually abutting the inner wall of the annular body 120.

[0096] In the embodiments of the present application, after the sealing structure 100 is assembled, the size of the second sealing protrusion 121 can meet the requirement of filling the gap between the annular body 120, the top cover 200, and the explosion-proof sheet 300. This reduces the probability of poor sealing due to the small size of the second sealing protrusion 121, and reduces the probability of new gaps being formed between the annular body 120, the top cover 200, or the explosion-proof sheet 300 due to the large size of the second sealing protrusion 121, thereby ensuring the sealing reliability of the sealing structure 100.

[0097] In some embodiments, referring to Figure 4 , the end of the support platform 130 close to the bottom support 140 is in the same plane as the side wall of the necked structure 21.

[0098] For example, referring to Figure 4 , the necked structure 21 includes an upper side wall, a lower side wall, and an inner side wall. The upper side wall and the lower side wall are oppositely spaced apart, and the inner side wall is located between the upper side wall and the lower side wall and connects the ends of the upper side wall and the lower side wall away from the edge of the shell 20. The necked structure 21 has a U-shaped groove structure. The support platform 130 is sealingly connected to the upper side wall. The end of the support platform 130 close to the bottom support 140 is in the same plane as the side wall of the necked structure 21. That is, the end of the support platform 130 close to the bottom support 140 is in the extension plane of the inner side wall of the necked structure 21.

[0099] In the embodiments of the present application, the assembled sealing structure 100 is deformed by being squeezed by the necked structure 21 and the edge 22. The deformed size of the support platform 130 is adapted to the size of the upper side wall of the necked structure 21, which ensures the sealing effect while reducing the probability of the support platform 130 being squeezed due to the large size after being deformed, thereby facilitating the improvement of the capacity of the battery cell.

[0100] In some embodiments, referring to Figure 8, the width of the sealing surface formed by the sealing fit between the support platform 130 and the necked structure 21 is D8, where 1.2mm≤D8≤1.9mm. That is, the width of the sealing surface formed by the sealing fit between the support platform 130 and the inner side wall of the necked structure 21 is D8. The value of D8 can be 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.9mm, or other values not listed.

[0101] In the embodiments of the present application, the width of the sealing surface formed by the sealing fit between the support platform 130 and the necked structure 21 ensures the sealing requirement while reducing the probability of the support platform 130 being excessively squeezed against the battery cell 30 due to the size of the sealing surface, which is conducive to improving the capacity of the battery cell.

[0102] In some embodiments, referring to Figure 8 , the width of the sealing surface formed by the sealing fit between the support platform 130 and the necked structure 21 is D8, which satisfies formula (3):

[0103] D8=D3+D4+D5 (3);

[0104] where D3 is the thickness of the side wall of the annular body 120;

[0105] D4 is the thickness of the first vertical plate 350;

[0106] D5 is the distance between the plane where the edge of the top cover 200 is located and the plane where the side wall of the necked structure 21 is located. That is, the horizontal distance between the plane where the edge of the top cover 200 is located and the plane where the inner side wall of the necked structure 21 is located.

[0107] In the embodiments of the present application, the width D8 of the sealing surface is related to the thickness D3 of the side wall of the annular body 120, the thickness D4 of the first vertical plate 350, and the distance D5 between the plane where the edge of the top cover 200 is located and the plane where the side wall of the necked structure 21 is located. That is, the width D8 of the sealing surface is related to the size of the inner side wall of the necked structure 21. This reduces the probability of the support platform 130 interfering with the necked structure 21 due to the small size of the sealing surface and the small size of the support platform 130, and reduces the probability of the support platform 130 being excessively squeezed against the battery cell 30 due to the large size of the sealing surface.

[0108] In some embodiments, D3, D4, and D5 at least satisfy one of the following conditions:

[0109] (1) 0.45mm≤D3≤0.60mm, where the value of D3 can be 0.45mm, 0.55mm, 0.57mm, 0.58mm, 0.59mm, 0.6mm, or other values not listed;

[0110] (2), 0.25mm≤D4≤0.30mm, wherein the value of D4 can be 0.25mm, 0.26mm, 0.28mm, 0.29mm, 0.30mm or other values not listed;

[0111] (3), 0.5mm≤D5≤1.0mm, wherein the value of D5 can be 0.5mm, 0.6mm, 0.8mm, 0.9mm, 1.0mm or other values not listed.

[0112] In the embodiments of the present application, the size design of D3, D4 and D5 can meet the width design requirement of the sealing surface and ensure the sealing effect.

[0113] In some embodiments, referring to Figure 6 and Figure 8 , the width of the sealing surface formed by the sealing fit of the support 130 and the necked structure 21 is D8, and the deformation height of the support 130 is D7, wherein the deformation height D7 of the support 130 refers to the vertical distance between one end of the support 130 close to the annular body 120 and the other end along the axial direction of the annular body 120. Wherein D8 and D7 satisfy formula (4):

[0114] D7=0.7452D8+0.0048 (4).

[0115] In the embodiments of the present application, the linear relationship between the width of the sealing surface and the deformation height of the support 130 satisfies formula (4). The width of the sealing surface is the same as the radial dimension of the upper side wall of the necked structure 21, and when designing the product, the size of the upper side wall of the necked structure 21 can be directly obtained, and formula (4) can be substituted to obtain the deformation height of the support 130. Combined with the compression deformation amount of the sealing structure 100, the size of the sealing structure 100 can be designed. It is beneficial to product design.

[0116] In some embodiments, referring to Figure 5 , the first cover 210 further comprises a connecting portion 240, the connecting portion 240 is located between the first cover 210 and the second cover 220, the inner diameter of the first cover 210 is greater than the outer diameter of the second cover 220, and the connecting portion 240 connects the first cover 210 and the second cover 220. A plurality of first pressure relief holes 230 are formed on the top cover 200 and are arranged at intervals along the circumferential direction of the top cover 200. The first pressure relief hole 230 is arranged on the connecting portion 240 and extends to the first cover 210 and the second cover 220.

[0117] In some embodiments, referring to Figure 6 and Figure 7The height of the explosion-proof sheet 300 is H2, where 0.65mm≤H2≤0.95mm. The height of the explosion-proof sheet 300 refers to the distance between the plane on which the side of the explosion-proof sheet 300 that is attached to the first cover body 210 is located and the plane on which the side of the explosion-proof sheet 300 that is attached to the hole plate 500 is located. The value of H2 can be 0.65mm, 0.72mm, 0.74mm, 0.75mm, 0.80mm, 0.87mm, or other values not listed.

[0118] In the embodiments of the present application, the height of the cap assembly 10 is reduced by reducing the height of the explosion-proof sheet 300, thereby increasing the space available for the battery cell 30. The size of the top cover 200 is designed to meet the space required for the explosion-proof sheet 300 to flip up after explosion and the assembly requirements of the explosion-proof sheet 300.

[0119] The embodiments of the present application also provide a battery 1 comprising the cap assembly 10 described in any of the above embodiments.

[0120] The embodiments of the present application also provide a battery pack comprising the battery 1 described above.

[0121] In the above embodiments, the description of each embodiment focuses on different aspects, and the parts not described in detail in a certain embodiment can be referred to the relevant description of other embodiments.

[0122] In the description of the present application, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first" and "second" can explicitly or implicitly include one or more features.

[0123] The cap assembly, battery, and battery pack provided by the embodiments of the present application are described in detail above, and the principles and implementation modes of the present application are described by applying specific examples. The above description of the embodiments is only used to help understand the method of the present application and its core idea; at the same time, for those skilled in the art, according to the idea of the present application, the specific implementation mode and application range will be changed, and the above description of the embodiments should not be understood as limiting the present application.

Claims

1. A cap assembly (10) characterized by, Comprising: From top to bottom, a top cover (200), an explosion-proof sheet (300), a hole plate gasket (400) and a hole plate (500) are sequentially arranged, and a first pressure relief hole (230) is arranged on the top cover (200); Wherein, the explosion-proof sheet (300) comprises a first body (310), a first inclined portion (340) and a second body (320) connected in sequence along the radial direction of the explosion-proof sheet (300), the first body (310) is attached to the top cover (200), and the second body (320) is located on the side of the first body (310) away from the top cover (200), along the thickness direction of the explosion-proof sheet (300), the projection of the first pressure relief hole (230) is located in the first inclined portion (340) and the second body (320).

2. The cap assembly (10) according to claim 1, characterized in that The first inclined portion (340) comprises a starting end (341) and an ending end (342), the starting end (341) is closer to the first body (310) than the ending end (342), and the starting end (341) is located between the inner wall of the first pressure relief hole (230) on the top cover (200) close to the edge of the top cover (200) and the edge of the top cover (200).

3. The cap assembly (10) according to claim 2, characterized in that The hole plate (500) is provided with a second pressure relief hole (510), and the ending end (342) is located between the inner wall of the second pressure relief hole (510) on the hole plate (500) close to the edge of the hole plate (500) and the edge of the hole plate (500).

4. The cap assembly (10) according to claim 3, characterized in that The diameter of the circle where the ending end (342) is located is S2, wherein, S2=S3+2a, Wherein, S3 is the outer diameter of the second pressure relief hole (510); a is the constant width of the punched edge on the hole plate (500), and the value range of a is.

5. The cap assembly of claim 4, wherein, 7.7mm≤S3≤9.8mm, 0.3mm≤a≤0.5mm.

6. The cap assembly (10) according to claim 1, characterized in that The first inclined portion (340) comprises a starting end (341) and an ending end (342), the starting end (341) is closer to the first body (310) than the ending end (342), and the diameter of the circle where the starting end (341) is located is S1, 11mm≤S1≤12mm.

7. The cap assembly (10) according to claim 6, characterized in that: The diameter of the circle where the ending end (342) is located is S2, 8.3mm≤S2≤10.8mm.

8. The cap assembly (10) according to claim 1, characterized in that: 0.15mm≤N1≤0.3mm.

9. The cap assembly (10) according to claim 1, characterized in that The hole plate gasket (400) is provided with a second inclined portion (410), and the second inclined portion (410) is attached to the first inclined portion (340).

10. The cap assembly (10) according to claim 9, characterized in that The hole plate (500) is provided with a third inclined portion (520), and the third inclined portion (520) is attached to the second inclined portion (410).

11. A battery (1) characterized in that Comprising: The cap assembly (10) according to any one of claims 1 to 10.

12. A battery pack, characterized by The battery according to claim 11.

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