Cylindrical battery, battery module and electric equipment

Abstract

The invention discloses a cylindrical battery, a battery module and electric equipment. The cylindrical battery comprises a shell, an electrode assembly, an end cover, an anti-explosion sheet and a pore plate, wherein the shell is provided with a shell opening; the electrode assembly is accommodated in the shell; the end cover is connected to the shell and covers the opening of the shell; the anti-explosion sheet is connected to the end cover; the pore plate is arranged between the anti-explosion piece and the electrode assembly, the pore plate is connected with the electrode assembly and the anti-explosion piece, the pore plate is welded to the anti-explosion piece to form a welding part, and the pore plate is provided with a first concave part surrounding the welding part; the section, coplanar with the central axis of the cylindrical battery, of the first concave part comprises a first bottom edge, a first side edge and a second side edge, and the second side edge is located on the side, away from the welding part, of the first side edge in the radial direction of the cylindrical battery; wherein the angle between the first side edge and the first bottom edge is beta, the angle between the second side edge and the first bottom edge is alpha, and alpha < beta < = 90 degrees.

Description

Technical Field

[0001] The present application relates to the field of batteries, and in particular to a cylindrical battery, a battery module and an electrical device. Background Art

[0002] With the rapid development of the battery industry, the application of batteries in electric vehicles, electric bicycles, power tools and other fields has become a trend. Cylindrical batteries are highly favored due to their advantages such as good grouping and high stability, and are gradually being used in various complex scenarios.

[0003] Since cylindrical batteries need to be used in multiple scenarios and multiple working conditions, how to improve the safety performance of cylindrical batteries has always been a research direction in the industry. Summary of the Invention

[0004] The present application provides a cylindrical battery, a battery module and an electrical device, which are beneficial to improving the current carrying capacity of the cylindrical battery and enhancing the safety performance of the cylindrical battery.

[0005] In the first aspect, the present application provides a cylindrical battery, which includes a shell, an electrode assembly, an end cover, an explosion-proof disk and an orifice plate, the shell having a shell opening; the electrode assembly is accommodated in the shell; the end cover is connected to the shell and covers the shell opening; the explosion-proof disk is connected to the end cover; the orifice plate is arranged between the explosion-proof disk and the electrode assembly, the orifice plate connects the electrode assembly and the explosion-proof disk, the orifice plate is welded to the explosion-proof disk and forms a welding portion, and the orifice plate is provided with a first recess surrounding the welding portion; the cross-section of the first recess coplanar with the central axis of the cylindrical battery includes a first bottom edge, a first side edge and a second side edge, and in the radial direction of the cylindrical battery, the second side edge is located on the side of the first side edge away from the welding portion; wherein the angle between the first side edge and the first bottom edge is β, the angle between the second side edge and the first bottom edge is α, and α<β≤90°.

[0006] In the embodiments of the present application, α<β, and the connection between the second side and the first bottom edge is more acute. When the cylindrical battery experiences thermal runaway, the explosion-proof disc can drive the orifice plate to bulge away from the electrode assembly through the weld, and the portion of the orifice plate near the connection between the second side and the first bottom edge is more likely to experience stress concentration. As the orifice plate bulges and deforms, the first bottom edge tilts toward the explosion-proof disc, and the angle between the second side and the first bottom edge further decreases, making the portion of the orifice plate near the connection between the second side and the first bottom edge more likely to break. Under the premise of a certain internal pressure design value that causes the orifice plate to break, through the differentiated design of α and β, the thickness of the first weak portion can be correspondingly increased, that is, the flow area of ​​the first weak portion is increased, and the resistance of the first weak portion is reduced. This can further reduce the temperature rise of the first weak portion when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery.

[0007] In one or more optional embodiments above, the welding portion is annular, and the outer diameter of the welding portion is φ1; in the radial direction of the cylindrical battery, the width of the welding portion is X1; 3.7≤φ1 / X1≤20.

[0008] In the embodiments of the present application, setting φ1 / X1 to be greater than or equal to 3.7 helps increase the outer diameter of the weld, thereby reducing the radial distance between the weld and the first recess. This also reduces the radial distance between the weld and the first weak portion, allowing the first weak portion to be subjected to greater stress when thermal runaway occurs in the cylindrical battery, further reducing the difficulty of fracture of the first weak portion. Setting φ1 / X1 to be less than or equal to 20, on the one hand, helps limit the outer diameter of the weld, reducing the thermal stress transmitted to the first weak portion during welding, and reducing the impact of welding on the fracture consistency of the first weak portion. On the other hand, it also helps increase the cross-section of the weld, improving the connection reliability between the explosion-proof disk and the orifice plate.

[0009] In one or more of the above optional embodiments, 1.3 mm ≤ φ1 ≤ 5 mm.

[0010] In the embodiment of the present application, setting φ1 to greater than or equal to 1.3 mm helps reduce the radial distance between the weld and the first weak portion, allowing the first weak portion to be subjected to greater stress when thermal runaway occurs in the cylindrical battery, further reducing the difficulty of breaking the first weak portion. Setting φ1 to less than or equal to 5 mm can limit the outer diameter of the weld, reducing the risk of the weld being too close to the first weak portion, thereby increasing the structural strength of the first weak portion and making it difficult to break.

[0011] In one or more of the above optional embodiments, 0.25 mm ≤ X1 ≤ 0.35 mm.

[0012] In the embodiment of the present application, setting X1 to be greater than or equal to 0.25 mm helps increase the cross-section of the weld, thereby improving the connection reliability between the rupture disk and the orifice plate. Setting X1 to be less than or equal to 0.35 mm helps reduce the effect of the weld on the weak portion of the rupture disk and the first weak portion of the orifice plate.

[0013] In one or more optional embodiments above, the diameter of the first recess is φ2, the diameter of the cylindrical battery is φ3; and 0.033≤φ2 / φ3≤0.35.

[0014] In the embodiment of the present application, setting Φ2 / φ3 to be greater than or equal to 0.033 helps increase the diameter of the first recess, thereby increasing the flow area of ​​the pressure relief channel formed after the first weak portion corresponding to the first recess breaks, thereby improving pressure relief efficiency. Setting Φ2 / φ3 to be less than or equal to 0.35 helps reduce the distance between the first recess and the weld, that is, the distance between the first weak portion and the weld, so that the first weak portion is subjected to greater stress when thermal runaway occurs in the cylindrical battery, further reducing the difficulty of breaking the first weak portion.

[0015] In one or more of the above optional embodiments, 1.8 mm ≤ φ2 ≤ 6 mm.

[0016] In the embodiment of the present application, setting φ2 to be greater than or equal to 1.8 mm helps increase the flow area of ​​the pressure relief channel formed after the first weak portion corresponding to the first recess breaks, thereby improving pressure relief efficiency. Setting φ2 to be less than or equal to 6 mm helps shorten the distance between the first recess and the weld, and thus shorten the distance between the first weak portion and the weld, reducing the risk of the first weak portion being too far from the weld and difficult to break.

[0017] In one or more of the above optional embodiments, 17 mm ≤ φ3 ≤ 55 mm.

[0018] In the embodiment of the present application, φ3 is set to be greater than or equal to 17 mm and less than or equal to 55 mm to optimize the size of the cylindrical battery.

[0019] In one or more optional embodiments above, 45°≤β≤90°, and 30°≤α≤80°.

[0020] In the embodiments of the present application, setting β to greater than or equal to 45° helps increase the angle between the first side and the first base, thereby adjusting the stress concentration area at the connection between the first side and the first base, so that the majority of this stress concentration area is located at the first weak portion, thereby reducing the difficulty of breaking the first weak portion. Setting β to less than or equal to 90° allows the explosion-proof disc to transfer stress to the first side through the weld when a cylindrical battery experiences thermal runaway, causing the first side to undergo significant deformation, thereby causing the first weak portion to break. Furthermore, setting α to greater than or equal to 30° and less than or equal to 80° allows the angle between the second side and the first base to be adjusted, making the connection between the second side and the first base more pointed, further increasing the likelihood of stress concentration at the connection between the second side and the first base, thereby reducing the difficulty of breaking the first weak portion.

[0021] In one or more optional embodiments above, in the radial direction of the cylindrical battery, the width of the first bottom side is X2; 0.05 mm ≤ X2 ≤ 0.15 mm.

[0022] In the embodiment of the present application, setting X2 to be greater than or equal to 0.05 mm helps increase the width of the first weak portion. This can increase the stress area of ​​the first weak portion when thermal runaway occurs in the cylindrical battery, thereby reducing the difficulty of breaking the first weak portion. Setting X2 to be less than or equal to 0.15 mm can reduce the risk of excessive stress dispersion caused by an excessively large width of the first weak portion.

[0023] In one or more optional embodiments above, the orifice plate is provided with a second recess, the bottom wall of the second recess is connected to the explosion-proof disk, and the bottom wall of the second recess is provided with a first recess; the bottom wall of the second recess includes a first weak portion corresponding to the first recess, the thickness of the first weak portion is H1, and the thickness of the bottom wall of the second recess is H2; 0.26≤H1 / H2≤0.6.

[0024] The first recess is positioned on the bottom wall of the second recess. In this case, the first weak portion is also positioned on the bottom wall of the second recess, and the thickness of the first weak portion can be smaller than that of the bottom wall of the second recess, thereby further reducing the difficulty of breaking the first weak portion. On this basis, setting H1 / H2 to greater than or equal to 0.26 helps increase the thickness of the first weak portion, thereby increasing the flow area of ​​the first weak portion and reducing the resistance of the first weak portion. This, in turn, can reduce the temperature rise of the first weak portion when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery. Setting H1 / H2 to less than or equal to 0.6 can reduce the risk of the first weak portion being difficult to break due to excessive thickness.

[0025] In one or more of the above optional embodiments, 0.06 mm ≤ H1 ≤ 0.09 mm.

[0026] In the embodiment of the present application, setting H1 to be greater than or equal to 0.06 mm helps increase the thickness of the first weak portion, thereby increasing the flow area of ​​the first weak portion and reducing the resistance of the first weak portion. This can further reduce the temperature rise of the first weak portion when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery. Setting H1 to be less than or equal to 0.09 can reduce the risk of the first weak portion being difficult to break due to excessive thickness.

[0027] In one or more of the above optional embodiments, 0.15 mm ≤ H2 ≤ 0.23 mm.

[0028] In the present embodiment, setting H2 to be greater than or equal to 0.15 mm helps increase the thickness of the bottom wall of the second recess, thereby improving the structural strength of the bottom wall of the second recess and thereby enhancing the reliability of the connection between the bottom wall of the second recess and the burst-proof disk. Setting H2 to be less than or equal to 0.23 mm can reduce the risk of the bottom wall of the second recess being too thick and thus affecting the fracture of the first weak portion.

[0029] In one or more optional embodiments above, in the axial direction of the cylindrical battery, the size of the portion of the weld formed on the explosion-proof disk is H3, and the thickness of the explosion-proof disk is H4; 0.2≤H3 / H4≤0.54.

[0030] In the present embodiment, setting H3 / H4 to greater than or equal to 0.2 helps increase the axial dimension of the weld portion formed on the rupture disk, thereby enhancing the connection reliability between the weld portion and the rupture disk. Setting H3 / H4 to less than or equal to 0.54 can reduce the impact of the weld portion on the rupture disk while also reducing the difficulty of welding the rupture disk to the orifice plate and improving welding efficiency.

[0031] In one or more of the above optional embodiments, 0.08 mm ≤ H3 ≤ 0.16 mm.

[0032] In the present embodiment, setting H3 to greater than 0.08 mm helps increase the axial dimension of the weld portion formed on the rupture disk, thereby enhancing the connection reliability between the weld portion and the rupture disk. Setting H3 to less than or equal to 0.16 mm can not only reduce the impact of the weld portion on the rupture disk, but also help reduce the difficulty of welding the rupture disk to the orifice plate, thereby improving welding efficiency.

[0033] In one or more of the above optional embodiments, 0.3 mm ≤ H4 ≤ 0.4 mm.

[0034] In the embodiment of the present application, H4 is set to be greater than or equal to 0.3 mm and less than or equal to 0.4 mm, which can optimize the thickness of the explosion-proof disk, on the one hand, enhancing the structural strength of the explosion-proof disk, and on the other hand, reducing the difficulty of breaking the explosion-proof disk.

[0035] In one or more of the above optional embodiments, the first recess is provided on the side of the orifice plate facing the end cap, which helps to drive the first side of the first recess to deform away from the electrode assembly through the explosion-proof disk, thereby tearing the first weak portion.

[0036] In one or more optional embodiments above, the welding portion is annular, the outer diameter of the welding portion is φ1, the diameter of the cylindrical battery is φ3; 0.05≤φ1 / φ3≤0.15.

[0037] In the embodiment of the present application, setting φ1 / φ3 to greater than or equal to 0.05 helps increase the outer diameter of the weld, thereby reducing the radial distance between the weld and the first recess. This also reduces the radial distance between the weld and the first weak portion. This allows the first weak portion to be subjected to greater stress when thermal runaway occurs in the cylindrical battery, further reducing the difficulty of fracturing the first weak portion. Setting φ1 / φ3 to less than or equal to 0.15 can reduce the risk of the weld being too close to the first weak portion, increasing the structural strength of the first weak portion and making it difficult to fracture.

[0038] In a second aspect, an embodiment of the present application further provides a battery module, which includes a plurality of cylindrical batteries provided by any embodiment of the first aspect.

[0039] In a third aspect, an embodiment of the present application further provides an electrical device comprising a plurality of cylindrical batteries provided in any one embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0041] Figure 1 A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0042] Figure 2 for Figure 1 A schematic cross-sectional view of a cylindrical battery is shown;

[0043] Figure 3 for Figure 1 Another schematic cross-sectional view of a cylindrical battery shown;

[0044] Figure 4 for Figure 3 Enlarged schematic diagram at AA;

[0045] Figure 5 for Figure 1 A schematic cross-sectional view of the orifice plate of the cylindrical battery shown;

[0046] Figure 6 for Figure 5 Enlarged schematic diagram at BB;

[0047] Figure 7 for Figure 5 Another enlarged schematic diagram at BB;

[0048] Figure 8 for Figure 1 Schematic diagram of the structure of the orifice plate of the cylindrical battery shown;

[0049] Figure 9 A schematic diagram of a battery module provided in some embodiments of the present application;

[0050] Figure 10 Schematic diagram of electrical equipment provided in some embodiments of the present application.

[0051] The reference numerals for the specific embodiments are as follows:

[0052] Cylindrical battery 1000; box 2000; battery module 3000; electrical equipment 4000;

[0053] Shell 10; electrode assembly 20; end cap 30; explosion-proof disk 40; orifice plate 50; welding portion 510; first recess 520; first bottom edge 521; first side edge 522; second side edge 523; first weak portion 530; second recess 540; orifice plate body 550; first sub-block 560; second sub-block 570; third recess 580; insulating member 60; collecting plate 70; shell opening K1; opening K2; radial direction X; axial direction Z. DETAILED DESCRIPTION

[0054] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in combination with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0055] The terms "first," "second," "third," and the like in the specification and claims of this application or the accompanying drawings are used to distinguish different objects, rather than to describe a specific order or a primary-secondary relationship. In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components in different embodiments are omitted.

[0056] References to "embodiments" in this application mean that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearance of this phrase in various places in the specification does not necessarily refer to the same embodiment, nor does it constitute an independent or alternative embodiment that is mutually exclusive of other embodiments.

[0057] In the description of this application, it should be noted that, unless otherwise specified or limited, the terms "mounted" and "connected" should be understood broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to direct connections, indirect connections through an intermediate medium, or internal connections between two components. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0058] In the embodiments of this application, "parallel" includes not only absolute parallelism but also approximately parallelism as commonly understood in engineering practice. Similarly, "perpendicular" also includes not only absolute perpendicularity but also approximately perpendicularity as commonly understood in engineering practice. For example, if the angle between two directions is 80°-90°, they are considered perpendicular; if the angle between two directions is 0°-10°, they are considered parallel.

[0059] The cylindrical battery, battery module and electrical equipment of the present application are described below with reference to the accompanying drawings.

[0060] Reference Figures 1 to 8 , an embodiment of the present application provides a cylindrical battery 1000.

[0061] The cylindrical battery 1000 may be, but is not limited to, a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, or a magnesium-ion battery.

[0062] The cylindrical battery 1000 may be a 21700 battery, an 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries.

[0063] In some embodiments, the cylindrical battery 1000 is a secondary battery. After discharge, the secondary battery can be recharged to activate the active material for continued use.

[0064] In some embodiments, the cylindrical battery 1000 includes a case 10 and an electrode assembly 20 housed in the case 10 .

[0065] In some embodiments, the electrode assembly 20 includes a first electrode sheet and a second electrode sheet with opposite polarities. During the charge and discharge process of the cylindrical battery 1000, active ions (e.g., lithium ions) are intercalated and released back and forth between the first electrode sheet and the second electrode sheet. One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet.

[0066] In some embodiments, the electrode assembly 20 includes a separator disposed between the first electrode sheet and the second electrode sheet, the separator insulating the first electrode sheet from the second electrode sheet. The separator can reduce the risk of short circuit between the positive and negative electrode sheets while allowing active ions to pass through.

[0067] In some embodiments, the first pole piece, the diaphragm, and the second pole piece are wound together.

[0068] In some embodiments, the first electrode sheet includes a first current collector and a first active material layer. The first current collector includes a first coated region coated with the first active material layer and a first hollow foil region not coated with the first active material layer. The first coated region and the first hollow foil region may be arranged along the axial direction Z of the cylindrical battery 1000.

[0069] In some embodiments, the first empty foil region is wound into multiple turns.

[0070] In some embodiments, the first electrode sheet includes a first electrode tab, which can be formed by flattening, smoothing, or patting the first hollow foil region. For example, the first hollow foil region can be squeezed from the outside to the inside along the radial direction X of the cylindrical battery 1000, and the end of the first hollow foil region away from the first coated region is bent to form the first electrode tab.

[0071] In other embodiments, the first electrode tab can be formed by flattening the first hollow foil region. For example, the first hollow foil region is squeezed in the axial direction Z of the electrode assembly 20 from a side of the first hollow foil region away from the first coated region, and the end of the first hollow foil region away from the first coated region is bent to form the first electrode tab.

[0072] In some embodiments, the second electrode sheet includes a second current collector and a second active material layer. The second current collector includes a second coated region coated with the second active material layer and a second hollow foil region not coated with the second active material layer. The second coated region and the second hollow foil region may be arranged in the axial direction Z of the cylindrical battery 1000.

[0073] In some embodiments, the second empty foil region is wound into multiple turns.

[0074] In some embodiments, the second electrode sheet includes a second electrode tab, which can be formed by flattening, smoothing, or patting the second hollow foil region. For example, the second hollow foil region can be squeezed from the outside to the inside along the radial direction X of the cylindrical battery 1000, and the end of the second hollow foil region away from the second coated region is bent to form the second electrode tab.

[0075] In other embodiments, the second electrode tab can be formed by flattening the second hollow foil region. For example, the second hollow foil region is squeezed in the axial direction Z of the electrode assembly 20 from a side of the second hollow foil region away from the second coated region, and the end of the second hollow foil region away from the second coated region is bent to form the second electrode tab.

[0076] In some embodiments, along the axial direction Z of the cylindrical battery 1000 , the first tab and the second tab are located at both ends of the electrode assembly 20 .

[0077] In some embodiments, one end of the housing 10 along the axial direction Z is provided with a housing opening K1 .

[0078] In some embodiments, the housing 10 includes a bottom wall and a side wall, wherein the side wall is connected to the bottom wall and surrounds the electrode assembly 20. An end of the side wall away from the bottom wall along the axial direction Z forms a housing opening.

[0079] The bottom wall and the side wall can be integrally formed. Alternatively, the bottom wall and the side wall can also be independently formed and connected by welding or other means.

[0080] In some embodiments, the cylindrical battery 1000 includes an end cap 30, which is connected to the housing 10 and covers the housing opening. The end cap 30 can close the housing opening, thereby forming a relatively closed accommodation space between the housing 10 and the end cap 30, which can accommodate components such as the electrode assembly 20 and the electrolyte.

[0081] In some embodiments, the bottom wall and the end cap 30 are arranged along the axial direction Z of the cylindrical battery 1000. The end cap 30 and the bottom wall are located on both sides of the electrode assembly 20, respectively.

[0082] In some embodiments, the end cap 30 is insulated from the side wall.

[0083] In some embodiments, the housing 10 and the end cap 30 may be made of steel, aluminum, composite metal, or other conductive materials. The housing 10 and the end cap 30 may be made of the same or different materials.

[0084] In some embodiments, the first tab is connected to the end cap 30 , and the second tab is connected to the bottom wall.

[0085] In some embodiments, the cylindrical battery 1000 includes an insulating structure disposed between the end cap 30 and the side wall. For example, the insulating structure may be insulating rubber or ceramic.

[0086] In some embodiments, the cylindrical battery 1000 includes a current collecting plate 70 , which is disposed between the end cap 30 and the electrode assembly 20 . The current collecting plate 70 is connected to the end cap 30 and the electrode assembly 20 .

[0087] In some embodiments, the current collecting plate 70 is connected to the first tab and the end cap 30. By providing the current collecting plate 70, an electrical connection between the end cap 30 and the electrode assembly 20 can be achieved, which is beneficial to improving the current carrying capacity and simplifying the assembly process of the cylindrical battery 1000.

[0088] In some embodiments, the current collecting plate 70 is welded to the first tab.

[0089] In some embodiments, the cylindrical battery 1000 further includes an explosion-proof disc 40 , which is disposed on the end cap 30 .

[0090] When the air pressure inside the cylindrical battery 1000 exceeds the upper limit that the explosion-proof plate 40 can withstand, the air pressure inside the cylindrical battery 1000 can cause the explosion-proof plate 40 to flip and explode away from the electrode assembly 20, thereby achieving the purpose of power off and pressure relief, which is beneficial to reducing the risk of explosion of the cylindrical battery 1000 due to excessive internal air pressure and improving the safety performance of the cylindrical battery 1000.

[0091] In some embodiments, the burst disk 40 may be connected to the end cap 30 by welding, riveting, bonding, or other suitable means.

[0092] In some embodiments, at least a portion of burst disk 40 may be located between end cap 30 and electrode assembly 20 .

[0093] In some embodiments, burst disk 40 connects collector plate 70 and end cap 30 .

[0094] In some embodiments, a portion of the burst disk 40 is located between the end cap 30 and the electrode assembly 20, and another portion of the burst disk 40 is bent toward the outside of the end cap 30 away from the electrode assembly 20 to cover the edge of the end cap 30. Optionally, an insulating structure is provided between the burst disk 40 and the sidewall.

[0095] In some embodiments, the cylindrical battery 1000 includes an orifice plate 50, which is disposed on the side of the burst disc 40 facing the electrode assembly 20, that is, between the current collecting plate 70 and the burst disc 40. The orifice plate 50 is connected to the current collecting plate 70 and the burst disc 40, and the orifice plate 50 enables electrical connection between the current collecting plate 70 and the burst disc 40. The end cap 30 is electrically connected to the first tab through the burst disc 40, the orifice plate 50, and the current collecting plate 70.

[0096] In some embodiments, the orifice plate 50 may be provided with an opening K2. The opening K2 of the orifice plate 50 may serve as a gas flow channel, allowing the gas inside the cylindrical battery 1000 to act on the explosion-proof disc 40 through the opening K2. This allows the explosion-proof disc 40 to flip when the air pressure inside the cylindrical battery 1000 is too high, thereby disconnecting the power supply from the orifice plate 50 and reducing safety risks. When the explosion-proof disc 40 flips, its weak portion breaks, thereby forming a channel, and the gas inside the cylindrical battery 1000 is discharged to the outside through the channel, thereby reducing safety risks.

[0097] In some embodiments, the cylindrical battery 1000 further includes an insulating member 60, at least a portion of which is disposed between a portion of the burst disc 40 and the orifice plate 50. The burst disc 40 can axially pass through the insulating member 60 and connect to the orifice plate 50. The insulating member 60 can separate the burst disc 40 and the orifice plate 50 in the event of thermal runaway of the cylindrical battery 1000, thereby reducing the risk of reconnection between the burst disc 40 and the orifice plate 50.

[0098] In some embodiments, the orifice plate 50 is welded to the explosion-proof disc 40 to form a welding portion 510, which, on the one hand, helps to form a continuous connection portion and improve the connection strength and reliability between the explosion-proof disc 40 and the orifice plate 50, and on the other hand, helps to reduce the resistance between the explosion-proof disc 40 and the orifice plate 50.

[0099] In some embodiments, the orifice plate 50 defines a first recess 520 surrounding the welding portion 510 .

[0100] The orifice plate 50 has a first weak portion 530 corresponding to the first recess 520. The thickness of the first weak portion 530 is smaller than the thickness of the other portions of the orifice plate 50. In the event of thermal runaway within the cylindrical battery 1000, the first weak portion 530 corresponding to the first recess 520 can rupture under the action of the rupture disk 40 and air pressure, thereby disconnecting the rupture disk 40 and reducing safety risks.

[0101] Furthermore, when thermal runaway occurs within the cylindrical battery 1000, the explosion-proof disc 40 can cause deformation of the orifice plate 50 at the weld 510. Therefore, the weld 510 is the region of greatest stress within the orifice plate 50. Therefore, in this embodiment of the present application, the first recess 520 is disposed around the weld 510, i.e., the first weak portion 530 is disposed around the weld 510. This helps increase the stress in the first weak portion 530 and reduces the difficulty of fracturing the first weak portion 530.

[0102] In some embodiments, a cross-section of the first recess 520 coplanar with the central axis of the cylindrical battery 1000 includes a first bottom edge 521 , a first side edge 522 , and a second side edge 523 . In the radial direction of the cylindrical battery 1000 , the second side edge 523 is located on the side of the first side edge 522 away from the welding portion 510 .

[0103] For example, the cross section of the first recess 520 may be trapezoidal.

[0104] The first side 522 and the second side 523 are disposed on opposite sides of the first bottom edge 521. In the radial direction, the second side 523 is located on the side of the first side 522 away from the welding portion 510, that is, the second side 523 is located on the side of the first side 522 away from the center of the orifice plate 50.

[0105] In some embodiments, the angle between the first side 522 and the first bottom 521 is β, the angle between the second side 523 and the first bottom 521 is α, and α<β≤90°.

[0106] The angle between the first side 522 and the first bottom 521 may be an acute angle or a right angle, and the angle between the second side 523 and the first bottom 521 may be an acute angle.

[0107] For example, in the axial direction away from the first bottom edge 521, the radial spacing between the first side edge 522 and the second side edge 523 tends to decrease, that is, in the radial direction, the width of the first bottom edge 521 may be greater than the width of the open end of the first recess 520, thereby helping to increase the width of the first weak portion 530. When thermal runaway occurs in the cylindrical battery 1000, the stress area of ​​the first weak portion 530 can be increased, thereby reducing the difficulty of breaking the first weak portion 530.

[0108] In the embodiment of the present application, α is less than β, and the connection between the second side 523 and the first bottom edge 521 is sharper. When the cylindrical battery 1000 experiences thermal runaway, the explosion-proof disc 40 can drive the orifice plate 50 to bulge away from the electrode assembly 20 through the welding portion 510, and the portion of the orifice plate 50 near the connection between the second side 523 and the first bottom edge 521 is more likely to produce stress concentration; as the orifice plate 50 bulges and deforms, the first bottom edge 521 tilts toward the explosion-proof disc 40, and the angle between the second side 523 and the first bottom edge 521 is further reduced, causing the portion of the orifice plate 50 near the connection between the second side 523 and the first bottom edge 521 to be more likely to break. Under the premise that the internal pressure that causes the orifice plate 50 to break is constant, through the differentiated design of α and β, the thickness of the first weak portion 530 can be increased accordingly, that is, the flow area of ​​the first weak portion 530 is increased, and the resistance of the first weak portion 530 is reduced. As a result, the temperature rise of the first weak portion 530 when current passes through can be reduced to a certain extent, thereby improving the flow capacity and cycle performance of the cylindrical battery 1000.

[0109] In some embodiments, the welding portion 510 is annular, which helps to increase the connection area between the orifice plate 50 and the explosion-proof disk 40 and improve the connection reliability between the two.

[0110] In some embodiments, the outer diameter of the welding portion 510 is φ1, and the width of the welding portion 510 in the radial direction of the cylindrical battery 1000 is X1. 3.7≤φ1 / X1≤20.

[0111] As examples, φ1 / X1 may be 3.7, 4, 5, 7, 9, 10, 13, 15, 17, 19, or 20.

[0112] In the embodiment of the present application, setting φ1 / X1 to be greater than or equal to 3.7 helps to increase the outer diameter of the welding portion 510, thereby reducing the radial distance between the welding portion 510 and the first recess 520, that is, reducing the radial distance between the welding portion 510 and the first weak portion 530, so that the first weak portion 530 can be subjected to greater stress when thermal runaway occurs in the cylindrical battery 1000, thereby further reducing the difficulty of breaking the first weak portion 530.

[0113] Setting φ1 / X1 to less than or equal to 20 helps, on the one hand, limit the outer diameter of the weld portion 510, reducing the thermal stress transmitted to the first weak portion 530 during welding, and lowering the impact of welding on the fracture consistency of the first weak portion 530. It also helps increase the cross-section of the weld portion 510, improving the connection reliability between the rupture disk 40 and the orifice plate 50.

[0114] In some embodiments, 1.3 mm ≤ φ1 ≤ 5 mm.

[0115] As an example, φ1 may be 1.3 mm, 1.5 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, or 5 mm.

[0116] In the embodiment of the present application, setting φ1 to be greater than or equal to 1.3 mm helps to reduce the radial distance between the welding portion 510 and the first weak portion 530, so that the first weak portion 530 can be subjected to greater stress when thermal runaway occurs in the cylindrical battery 1000, thereby further reducing the difficulty of breaking the first weak portion 530.

[0117] Setting φ1 to be less than or equal to 5 mm can limit the outer diameter of the welding portion 510 , thereby reducing the risk of the welding portion 510 being too close to the first weak portion 530 , which may increase the structural strength of the first weak portion 530 and make it difficult to break.

[0118] In some embodiments, 0.25 mm ≤ X1 ≤ 0.35 mm.

[0119] As an example, X1 may be 0.25 mm, 0.26 mm, 0.27 mm, 0.28 mm, 0.29 mm, 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, or 0.35 mm.

[0120] In the embodiment of the present application, setting X1 to be greater than or equal to 0.25 mm helps to increase the cross-section of the welding portion 510 and improve the connection reliability between the explosion-proof disk 40 and the orifice plate 50 .

[0121] Setting X1 to be less than or equal to 0.35 mm helps reduce the impact of the weld portion 510 on the weak portion of the burst disk 40 and the first weak portion 530 of the orifice plate 50 .

[0122] In some embodiments, the diameter of the first recess 520 is φ2, and the diameter of the cylindrical battery 1000 is φ3. 0.033≤φ2 / φ3≤0.35.

[0123] The diameter of the first recess 520 may be the diameter of a center line of the bottom wall of the first recess 520 in the radial direction.

[0124] As an example, Φ2 / φ3 may be 0.033, 0.04, 0.07, 0.09, 0.1, 0.15, 0.2, 0.25, 0.3, or 0.35.

[0125] In the embodiment of the present application, setting Φ2 / φ3 to be greater than or equal to 0.033 helps to increase the diameter of the first recess 520, increase the flow area of ​​the pressure relief channel formed after the first weak portion 530 corresponding to the first recess 520 is broken, and improve the pressure relief efficiency.

[0126] Setting Φ2 / φ3 to be less than or equal to 0.35 is beneficial for reducing the distance between the first recess 520 and the welding portion 510, that is, reducing the distance between the first weak portion 530 and the welding portion 510, so that the first weak portion 530 can be subjected to greater stress when thermal runaway occurs in the cylindrical battery 1000, thereby further reducing the difficulty of breaking the first weak portion 530.

[0127] In some embodiments, 1.8 mm ≤ φ2 ≤ 6 mm.

[0128] As an example, φ2 may be 1.8 mm, 2 mm, 2.5 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, 5.5 mm, or 6 mm.

[0129] In the embodiment of the present application, setting φ2 to be greater than or equal to 1.8 mm helps to increase the flow area of ​​the pressure relief channel formed after the first weak portion 530 corresponding to the first recess 520 is broken, thereby improving the pressure relief efficiency.

[0130] Setting φ2 to be less than or equal to 6 mm helps shorten the distance between the first recess 520 and the welding portion 510 , that is, shorten the distance between the first weak portion 530 and the welding portion 510 , thereby reducing the risk of the first weak portion 530 and the welding portion 510 being too far apart and difficult to break.

[0131] In some embodiments, 17 mm ≤ φ3 ≤ 55 mm.

[0132] As an example, Φ3 may be 17 mm, 20 mm, 21 mm, 25 mm, 30 mm, 35 mm, 40 mm, 45 mm, 50 mm, or 55 mm.

[0133] In the embodiment of the present application, φ3 is set to be greater than or equal to 17 mm and less than or equal to 55 mm to optimize the size of the cylindrical battery 1000 .

[0134] In some embodiments, 45°≤β≤90°.

[0135] As an example, β may be 45°, 50°, 55°, 60°, 65°, 70°, 75°, 80°, 85°, or 90°.

[0136] In the embodiment of the present application, setting β to be greater than or equal to 45° helps to increase the angle between the first side 522 and the first bottom edge 521, thereby adjusting the stress concentration area at the connection between the first side 522 and the first bottom edge 521, so that most of the stress concentration area is located at the first weak portion 530, thereby reducing the difficulty of breaking the first weak portion 530.

[0137] β is set to be less than or equal to 90°. Therefore, when the cylindrical battery 1000 experiences thermal runaway, the explosion-proof plate 40 can transfer stress to the first side 522 through the welding portion 510, causing the first side 522 to undergo a large deformation, thereby causing the first weak portion 530 to break.

[0138] In some embodiments, 30°≤α≤80°.

[0139] As an example, α may be 30°, 35°, 40°, 45°, 50°, 55°, 60°, 65°, 70°, 75°, or 80°.

[0140] In the embodiment of the present application, α is set to be greater than or equal to 30° and less than or equal to 80°, so that the angle between the second side 523 and the first bottom edge 521 can be adjusted, so that the connection between the second side 523 and the first bottom edge 521 is sharper, so as to further increase the possibility of stress concentration at the connection between the second side 523 and the first bottom edge 521, thereby reducing the difficulty of breaking the first weak portion 530.

[0141] In some embodiments, in the radial direction of the cylindrical battery 1000 , the width of the first bottom side 521 is X2. 0.05 mm ≤ X2 ≤ 0.15 mm.

[0142] As an example, X2 may be 0.05 mm, 0.06 mm, 0.07 mm, 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, or 0.15 mm.

[0143] In the embodiment of the present application, setting X2 to be greater than or equal to 0.05 mm helps to increase the width of the first weak portion 530. When thermal runaway occurs in the cylindrical battery 1000, the stress area of ​​the first weak portion 530 can be increased, thereby reducing the difficulty of breaking the first weak portion 530.

[0144] Setting X2 to be less than or equal to 0.15 mm can reduce the risk of excessive stress dispersion caused by the excessive width of the first weak portion 530 .

[0145] In some embodiments, in the radial direction, the width of the open end of the first recess 520 is X3. 0.5≤X3 / X2<1.

[0146] As an example, X3 / X2 may be 0.5, 0.6, 0.7, 0.8, or 0.9.

[0147] In the embodiment of the present application, X3 / X2 is set to be greater than or equal to 0.5 and less than 1, which can cooperate with the angle between the first side 522 and the first bottom edge 521 and the angle between the second side 523 and the first bottom edge 521 to achieve flexible adjustment of the stress concentration area of ​​the first weak portion 530, so as to further reduce the difficulty of breaking the first weak portion 530.

[0148] In some embodiments, the orifice plate 50 is provided with a second recess 540 , the bottom wall of the second recess 540 is connected to the explosion-proof disk 40 , and the bottom wall of the second recess 540 is provided with a first recess 520 .

[0149] The bottom wall of the second recess 540 can be connected to the bursting disc 40 and connected to the end cap 30 via the bursting disc 40. The bottom wall of the second recess 540 can be welded to the bursting disc 40 to form a weld 510. The thickness of the bottom wall of the second recess 540 can be thinner than the thickness of other areas of the orifice plate 50. The first recess 520 is disposed in the bottom wall of the second recess 540. In this case, the first weakened portion 530 is also disposed in the bottom wall of the second recess 540. The thickness of the first weakened portion 530 can be thinner than the thickness of the bottom wall of the second recess 540, thereby further reducing the difficulty of breaking the first weakened portion 530.

[0150] In some embodiments, the bottom wall of the second recess 540 includes a first weak portion 530 corresponding to the first recess 520 , the first weak portion 530 has a thickness H1 , and the bottom wall of the second recess 540 has a thickness H2 . 0.26≤H1 / H2≤0.6.

[0151] As examples, H1 / H2 may be 0.26, 0.3, 0.35, 0.4, 0.41, 0.45, 0.5, 0.55, or 0.6.

[0152] In the embodiment of the present application, setting H1 / H2 to be greater than or equal to 0.26 helps to increase the thickness of the first weak portion 530, thereby increasing the flow area of ​​the first weak portion 530 and reducing the resistance of the first weak portion 530. This can further reduce the temperature rise of the first weak portion 530 when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery 1000.

[0153] Setting H1 / H2 to be less than or equal to 0.6 can reduce the risk of the first weak portion 530 being difficult to break due to excessive thickness.

[0154] In some embodiments, 0.06 mm ≤ H1 ≤ 0.09 mm.

[0155] As an example, H1 may be 0.06 mm, 0.065 mm, 0.07 mm, 0.075 mm, 0.08 mm, 0.085 mm, or 0.09 mm.

[0156] In the embodiment of the present application, setting H1 to be greater than or equal to 0.06 mm helps to increase the thickness of the first weak portion 530, thereby increasing the flow area of ​​the first weak portion 530 and reducing the resistance of the first weak portion 530. This can further reduce the temperature rise of the first weak portion 530 when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery 1000.

[0157] Setting H1 to be less than or equal to 0.09 can reduce the risk of the first weak portion 530 being difficult to break due to excessive thickness.

[0158] In some embodiments, 0.15 mm ≤ H2 ≤ 0.23 mm.

[0159] As an example, H2 may be 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.2 mm, 0.21 mm, 0.22 mm, or 0.23 mm.

[0160] In the embodiment of the present application, setting H2 to be greater than or equal to 0.15 mm helps to increase the thickness of the bottom wall of the second recess 540, improve the structural strength of the bottom wall of the second recess 540, and further improve the connection reliability between the bottom wall of the second recess 540 and the explosion-proof disk 40.

[0161] Setting H2 to be less than or equal to 0.23 mm can reduce the risk of the bottom wall of the second recess 540 being too thick and affecting the breakage of the first weak portion 530 .

[0162] In some embodiments, in the axial direction of the cylindrical battery 1000 , the size of the portion of the weld 510 formed on the explosion-proof disk 40 is H3 , and the thickness of the explosion-proof disk 40 is H4 . 0.2≤H3 / H4≤0.54.

[0163] Welding portion 510 connects bursting disk 40 and orifice plate 50. Axially, welding portion 510 includes a first portion and a second portion. The first portion is formed in bursting disk 40 and located within bursting disk 40, while the second portion is formed in orifice plate 50 and located within orifice plate 50. Axially, the first portion has a dimension H3, which can be either the maximum dimension of the first portion in the axial direction or the average dimension of the first portion in the axial direction.

[0164] As examples, H3 / H4 may be 0.2, 0.25, 0.3, 0.35, 0.4, 0.43, 0.45, 0.5, or 0.54.

[0165] In the embodiment of the present application, setting H3 / H4 to be greater than or equal to 0.2 helps to increase the axial size of the portion of the weld 510 formed on the burst disk 40, thereby enhancing the connection reliability between the weld 510 and the burst disk 40.

[0166] Setting H3 / H4 to be less than or equal to 0.54 can, on the one hand, reduce the impact of the setting of the welding portion 510 on the explosion-proof disk 40, and on the other hand, help reduce the difficulty of welding the explosion-proof disk 40 and the orifice plate 50, thereby improving welding efficiency.

[0167] In some embodiments, 0.08 mm ≤ H3 ≤ 0.16 mm.

[0168] As an example, H3 may be 0.08 mm, 0.09 mm, 0.1 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, or 0.16 mm.

[0169] In the embodiment of the present application, setting H3 to be greater than 0.08 mm helps to increase the axial size of the portion of the weld portion 510 formed on the burst-proof disk 40 , thereby enhancing the connection reliability between the weld portion 510 and the burst-proof disk 40 .

[0170] Setting H3 to be less than or equal to 0.16 mm can, on the one hand, reduce the impact of the setting of the welding portion 510 on the explosion-proof disk 40, and on the other hand, help reduce the difficulty of welding the explosion-proof disk 40 and the orifice plate 50, thereby improving welding efficiency.

[0171] In some embodiments, 0.3 mm ≤ H4 ≤ 0.4 mm.

[0172] As examples, H4 may be 0.3 mm, 0.31 mm, 0.32 mm, 0.33 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.37 mm, 0.38 mm, 0.39 mm, or 0.4 mm.

[0173] In the embodiment of the present application, H4 is set to be greater than or equal to 0.3 mm and less than or equal to 0.4 mm, which can optimize the thickness of the explosion-proof plate 40, on the one hand, enhancing the structural strength of the explosion-proof plate 40, and on the other hand, reducing the difficulty of breaking the explosion-proof plate 40.

[0174] In some embodiments, the first recess 520 is disposed on the side of the orifice plate 50 facing the end cover 30 , which helps to drive the first side 522 of the first recess 520 to deform away from the electrode assembly 20 through the explosion-proof plate 40 , thereby tearing the first weak portion 530 .

[0175] In some embodiments, the welding portion 510 is annular, the outer diameter of the welding portion 510 is φ1, and the diameter of the cylindrical battery 1000 is φ3. 0.05≤φ1 / φ3≤0.15.

[0176] As an example, φ1 / φ3 may be 0.05, 0.06, 0.07, 0.08, 0.09, 0.1, 0.11, 0.12, 0.13, 0.14, or 0.15.

[0177] In the embodiment of the present application, setting φ1 / φ3 to be greater than or equal to 0.05 helps to increase the outer diameter of the welding portion 510, thereby reducing the radial distance between the welding portion 510 and the first recess 520, that is, reducing the distance between the welding portion 510 and the first weak portion 530 in the radial direction X, so that the first weak portion 530 can be subjected to greater stress when thermal runaway occurs in the cylindrical battery 1000, thereby further reducing the difficulty of breaking the first weak portion 530.

[0178] Setting φ1 / φ3 to be less than or equal to 0.15 can reduce the risk that the structural strength of the first weak portion 530 increases and becomes difficult to break due to the welding portion 510 being too close to the first weak portion 530 .

[0179] In some embodiments, the orifice plate 50 includes an orifice plate body 550, a first sub-block 560, and a second sub-block 570. The orifice plate body 550 is provided with a third recess 580 surrounding the welding portion 510. The cross section of the third recess 580 can be square, which helps to reduce its manufacturing difficulty.

[0180] In some embodiments, the first sub-block 560 and the second sub-block 570 are disposed in the third recess 580 and are both disposed around the welding portion 510. Radially, the first sub-block 560 and the second sub-block 570 are spaced apart, and the first sub-block 560, the second sub-block 570, and the bottom wall of the third recess 580 define the first recess 520.

[0181] The first side 522 and the second side 523 of the first recess 520 are respectively located on the two side surfaces of the first sub-block 560 and the second sub-block 570 that are close to each other. The two side surfaces of the first sub-block 560 and the second sub-block 570 that are close to each other and a part of the bottom wall of the third recess 580 can jointly define the first recess 520, thereby reducing the difficulty of preparing the first recess 520 and improving the production efficiency of the orifice plate 50.

[0182] In some embodiments, in the radial direction, the second sub-block 570 is located on the side of the first sub-block 560 away from the welding portion 510, and the hardness of the second sub-block 570 is greater than the hardness of the orifice plate body 550, so that the stress area at the connection between the side of the second sub-block 570 and the bottom wall of the third recess 580 can be adjusted. When the cylindrical battery 1000 has thermal runaway, the stress at the connection can be concentrated on the orifice plate body 550 corresponding to the third recess 580, that is, located at the first weak portion 530, thereby contributing to the rupture of the first weak portion 530.

[0183] Reference Figure 9 , an embodiment of the present application further provides a battery module 3000, the battery module 3000 including a plurality of cylindrical batteries 1000 provided according to any embodiment of the present application.

[0184] In some embodiments, the battery module 3000 further includes a plurality of bus bars (not shown) that connect the plurality of cylindrical batteries 1000 .

[0185] In some embodiments, the battery module 3000 further includes a box body 2000 , and the cylindrical batteries 1000 are accommodated in the box body 2000 .

[0186] Reference Figure 10 , an embodiment of the present application further provides an electric device 4000, which includes the cylindrical battery 1000 provided in any embodiment of the present application or the battery module 3000 provided in any embodiment of the present application.

[0187] The electrical device 4000 in the embodiments of the present application may be a portable device, an electric toy, a drone, an electric tool, an energy storage system, and the like. Electric tools include metal cutting tools and cleaning tools, such as electric drills, electric wrenches, vacuum cleaners, robot vacuums, power-assisted bicycles, and the like. The embodiments of the present application do not impose any particular restrictions on the aforementioned electrical devices.

[0188] Example:

[0189] Example 1:

[0190] <Cylindrical Battery Preparation>

[0191] The steel shell is grooved according to the production line process, one end of the conductive aluminum sheet is welded to the inner wall of the steel shell, and the other end is welded to the lower surface of the orifice plate. Then, the components consisting of the end cover, explosion-proof plate, orifice plate and other structures are inserted into the steel shell, and the shell is sealed to obtain a cylindrical battery with a specification of 21700 for testing; a circular hole with a diameter of 5mm is drilled at the bottom of the cylindrical battery shell using drilling equipment.

[0192] Among them, the thickness H1 of the first weak portion 530 of the orifice plate is 0.07 mm, the thickness H2 of the bottom wall of the second recess 540 is 0.17 mm, the angle β between the first side 522 and the first bottom 521 of the first recess 520 is 85°, and the angle α between the second side 523 and the first bottom 521 is 70°.

[0193] Example 2: The preparation method of the cylindrical battery is the same as that of Example 1, and the differences are shown in Table 1.

[0194] Example 3: The preparation method of the cylindrical battery is the same as that of Example 1, and the differences are shown in Table 1.

[0195] Comparative Example 1: The preparation method of the cylindrical battery is the same as that of Example 1, and the differences are shown in Table 1.

[0196] <External circuit>

[0197] The two magnetic terminals are respectively attached to the end cover and the shell wall to form a loop, and the loop current is monitored by a current sensor.

[0198] <Explosion Test>

[0199] The cylindrical batteries prepared in Examples 1-3 and Comparative Example 1 were tested.

[0200] Use a pneumatic burst tester (model SC-QYBP-10, Xiamen Sanchuang Scientific Instrument Testing Equipment Co., Ltd.), open the inflation valve, and inflate the interior of the shell 10 through the circular hole at the bottom of the shell 10 at a speed of 0.1 MPa / s until the external circuit is disconnected and the current sensor detects the circuit break, and records the power-off pressure (i.e., the internal pressure of the shell when the circuit is disconnected).

[0201] The experimental results are shown in Table 1 below:

[0202]

[0203] Referring to Examples 1-2 and Comparative Example 1, when α < β ≤ 90°, the junction between the second side and the first bottom edge is more acute. When the cylindrical battery experiences thermal runaway, the rupture disc can cause the orifice plate to bulge away from the electrode assembly via the weld, making the portion of the orifice plate near the junction of the second side and the first bottom edge more susceptible to stress concentration. Furthermore, as the orifice plate bulges and deforms, the first bottom edge tilts toward the rupture disc, further reducing the angle α between the second side and the first bottom edge, making the portion of the orifice plate near the junction of the second side and the first bottom edge more susceptible to fracture. Referring to Example 3 and Comparative Example 1, under the premise of a constant internal pressure that causes the orifice plate to fracture, by differentially designing α and β, the thickness of the first weak portion can be correspondingly increased, thereby increasing the flow area of ​​the first weak portion and reducing its resistance. This, in turn, can reduce the temperature rise of the first weak portion when current passes through it to a certain extent, thereby improving the flow capacity of the cylindrical battery.

[0204] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and components may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features described in the various embodiments may be combined in any manner as long as there are no structural conflicts. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions within the scope of the claims.

Claims

1. A cylindrical battery, characterized in that: include: a housing having a housing opening; an electrode assembly, housed in the housing; an end cover connected to the housing and covering the housing opening; a bursting disc connected to the end cover; an orifice plate disposed between the explosion-proof disk and the electrode assembly, the orifice plate connecting the electrode assembly and the explosion-proof disk, the orifice plate being welded to the explosion-proof disk to form a weld portion, and the orifice plate being provided with a first recess surrounding the weld portion; A cross section of the first recessed portion coplanar with the central axis of the cylindrical battery includes a first bottom edge, a first side edge, and a second side edge, wherein in the radial direction of the cylindrical battery, the second side edge is located on a side of the first side edge away from the welding portion; The angle between the first side and the first bottom is β, the angle between the second side and the first bottom is α, and α<β≤90°.

2. The cylindrical battery according to claim 1, characterized in that: The welding portion is annular, and the outer diameter of the welding portion is φ1; in the radial direction of the cylindrical battery, the width of the welding portion is X1; 3.7≤φ1 / X1≤20.

3. The cylindrical battery according to claim 2, characterized in that: 1.3mm≤φ1≤5mm; and / or, 0.25mm≤X1≤0.35mm.

4. The cylindrical battery according to any one of claims 1 to 3, characterized in that: The diameter of the first concave portion is φ2, and the diameter of the cylindrical battery is φ3; 0.033≤Φ2 / φ3≤0.

35.

5. The cylindrical battery according to claim 4, characterized in that: 1.8mm≤φ2≤6mm; and / or, 17mm≤φ3≤55mm.

6. The cylindrical battery according to any one of claims 1 to 5, characterized in that: 45°≤β≤90°，30°≤α≤80°。 7. The cylindrical battery according to any one of claims 1 to 6, characterized in that: In the radial direction of the cylindrical battery, the width of the first bottom side is X2; 0.05mm≤X2≤0.15mm.

8. The cylindrical battery according to any one of claims 1 to 7, characterized in that: The orifice plate is provided with a second recess, the bottom wall of the second recess is connected to the explosion-proof disk, and the bottom wall of the second recess is provided with the first recess; The bottom wall of the second recess includes a first weak portion corresponding to the first recess, the thickness of the first weak portion is H1, and the thickness of the bottom wall of the second recess is H2; 0.26≤H1 / H2≤0.

6.

9. The cylindrical battery according to claim 8, characterized in that: 0.06mm≤H1≤0.09mm, and / or, 0.15mm≤H2≤0.23mm.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: In the axial direction of the cylindrical battery, the size of the portion of the weld formed on the explosion-proof disk is H3, and the thickness of the explosion-proof disk is H4; 0.2≤H3 / H4≤0.

54.

11. The cylindrical battery according to claim 10, characterized in that: 0.08mm≤H3≤0.16mm; and / or, 0.3mm≤H4≤0.4mm.

12. The cylindrical battery according to any one of claims 1 to 11, characterized in that: The first recess is provided on a side of the orifice plate facing the end cover.

13. The cylindrical battery according to any one of claims 1 to 12, characterized in that: The welding portion is annular, the outer diameter of the welding portion is φ1, and the diameter of the cylindrical battery is φ3; 0.05≤φ1 / φ3≤0.

15.

14. A battery module, characterized in that: The invention comprises a plurality of cylindrical batteries according to any one of claims 1 to 13.

15. An electrical device, characterized in that: The invention comprises a cylindrical battery according to any one of claims 1 to 13.

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