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, the housing has a housing opening. The electrode assembly is housed within the case. The end cover is connected to the shell and covers the opening of the shell. And 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 and forms an annular welding part, a first concave part is arranged on the side, facing the electrode assembly, of the pore plate, and the first concave part surrounds the welding part. The outer radius of the welding part is d, the radius of the first concave part is D, and d / D is larger than or equal to 0.80 and smaller than or equal to 0.91; the radius of the cylindrical battery is A, 0.074 < = d / A < = 0.086, and 8.5 < = A < = 27.5 mm.

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

[0003] Due to the harsh working conditions of different application scenarios, higher requirements are placed on the charge and discharge rate, service life, safety and other performance of cylindrical batteries. How to improve the current capacity while ensuring the safety performance of cylindrical batteries has become the research and development direction of industry insiders. Summary of the Invention

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

[0005] In a first aspect, the present application provides a cylindrical battery comprising a shell, an electrode assembly, an end cap, an explosion-proof disc, and an orifice plate. The shell has a shell opening. The electrode assembly is accommodated in the shell. The end cap is connected to the shell and covers the shell opening. The explosion-proof disc is connected to the end cap. The orifice plate is disposed between the explosion-proof disc and the electrode assembly, the orifice plate connects the electrode assembly and the explosion-proof disc, the orifice plate is welded to the explosion-proof disc and forms an annular weld portion, and a first recess is provided on the side of the orifice plate facing the electrode assembly, the first recess surrounding the weld portion. The outer radius of the weld portion is d, the radius of the first recess is D, 0.80≤d / D≤0.91; the radius of the cylindrical battery is A, 0.074≤d / A≤0.086, 8.5mm≤A≤27.5mm.

[0006] The present application sets d / A to be greater than or equal to 0.074 to increase the circumference of the weld, improve the flow capacity and strength of the weld, reduce the risk of cracking of the weld when the cylindrical battery is subjected to external impact, and improve the reliability of the cylindrical battery. The present application sets d / A to be less than or equal to 0.086, which can shorten the welding time when the flow capacity and strength of the weld meet the requirements, and reserve more areas for the orifice plate to be provided with through holes, which is conducive to exhaust. When the cylindrical battery thermal runaway occurs, the explosion-proof plate flips in the direction away from the electrode assembly and drives the weld to move in the direction away from the electrode assembly; when the weld moves, the part of the orifice plate between the weld and the first recess is bent and deformed, and the part of the orifice plate corresponding to the first recess is subjected to force. The present application sets the first recess on the side of the orifice plate facing the electrode assembly, which can increase the stress concentration of the orifice plate near the first recess when the orifice plate is subjected to tension, thereby reducing the difficulty of breaking the orifice plate. The present application also sets d / D to be greater than or equal to 0.80, which can reduce the distance between the first recess and the welding part, increase the bending amplitude of the part of the orifice plate located between the welding part and the first recess, and the force on the part corresponding to the orifice plate and the first recess, thereby reducing the difficulty of breaking the orifice plate. When the cut-off pressure value of the orifice plate remains unchanged, the depth of the first recess can be reduced, the minimum thickness of the part corresponding to the orifice plate and the first recess can be increased, the internal resistance of the cylindrical battery can be reduced, and the temperature rise at the orifice plate can be reduced, thereby improving the safety performance and overcurrent capacity of the cylindrical battery. The present application sets d / D to be less than or equal to 0.91, and there is a certain distance between the welding part and the first recess in the radial direction of the cylindrical battery, which can reduce the heat transferred to the part corresponding to the orifice plate and the first recess during welding, and reduce the risk of welding to the first recess due to process errors.

[0007] In one or more of the above optional embodiments, 0.9 mm ≤ D ≤ 2.5 mm. In this embodiment, D is set to 0.9 mm-2.5 mm, which is compatible with cylindrical batteries of various specifications.

[0008] In one or more of the above optional embodiments, a second recess is provided on the side of the orifice plate facing the electrode assembly, the bottom wall of the second recess being welded to the explosion-proof disk to form a welded portion, and a first recess is provided on the side of the bottom wall of the second recess facing the electrode assembly. The bottom wall of the second recess includes a first weakened portion corresponding to the first recess, the first weakened portion having a thickness H1, and the bottom wall of the second recess having a thickness H2, where 0.48 ≤ H1 / H2 ≤ 0.55, and 0.15 mm ≤ H2 ≤ 0.23 mm.

[0009] In this embodiment, H2 is set to be less than or equal to 0.23mm to reduce the difficulty of welding the bottom wall of the second recess to the explosion-proof plate. In this embodiment, H2 is set to be greater than or equal to 0.15mm to take into account the strength of the bottom wall of the second recess and reduce the risk of cracking at the junction of the weld and the bottom wall of the second recess. In this application, d / D is set to be greater than or equal to 0.80, reducing the radial distance between the weld and the first recess in the cylindrical battery, which can reduce the difficulty of the first weak part breaking when the cylindrical battery thermal runaways. Therefore, in this embodiment, H1 / H2 can be set to be greater than or equal to 0.48 to increase the flow capacity of the first weak part, reduce the temperature rise at the orifice plate, and improve the safety performance and flow capacity of the cylindrical battery. In this embodiment, H1 / H2 can be set to be less than or equal to 0.55, so that the first weak part can break in time when the cylindrical battery thermal runaways, thereby disconnecting the current circuit and achieving power-off protection.

[0010] In one or more of the above optional embodiments, in the radial direction of the cylindrical battery, the minimum distance D1 between the weld portion and the first recess is greater than or equal to 0.05 mm. In this embodiment, setting D1 to be greater than or equal to 0.05 mm can reduce the heat transferred to the first weak portion during welding, alleviate fatigue of the first weak portion, and reduce the risk of welding to the first weak portion due to process errors.

[0011] In one or more of the above optional embodiments, a second recess is provided on the side of the orifice plate facing the electrode assembly, the bottom wall of the second recess is welded to the explosion-proof disk to form a weld, and the first recess is provided on the bottom wall of the second recess facing the electrode assembly. The radius of the second recess is B, and 1.05≤B / D≤1.45.

[0012] When the orifice plate is pulled by the explosion-proof disk, a stress concentration point is easily generated at the intersection of the bottom wall of the second recess and the side wall of the second recess. In this embodiment, the B / D ratio is set to less than or equal to 1.45, which can reduce the distance between the side walls of the first and second recesses. In the event of thermal runaway of the cylindrical battery, the stress on the first weak part is increased, reducing the difficulty of fracturing the orifice plate. In this embodiment, the B / D ratio is set to greater than or equal to 1.05, which can reduce the risk of unstable disconnect pressure values ​​caused by excessive influence of stress concentration points on the first weak part, and improve the consistency of disconnect pressure values.

[0013] In one or more optional embodiments above, BD≥0.1 mm. This embodiment can reduce the risk of unstable off-state pressure value caused by excessive influence of the stress concentration point on the first weak portion, and improve the consistency of the off-state pressure value.

[0014] 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, 0.3mm≤H4≤0.4mm.

[0015] In this embodiment, H3 / H4 is set to be greater than or equal to 0.2, which helps increase the axial dimension of the portion of the weld formed on the burst-proof disk, thereby enhancing the connection reliability between the weld and the burst-proof disk and improving the flow capacity between the weld and the burst-proof disk. In this embodiment, H3 / H4 is set to be less than or equal to 0.54, which can not only reduce the impact of the weld on the burst-proof disk, but also help reduce the difficulty of welding the burst-proof disk to the orifice plate, thereby improving welding efficiency.

[0016] In one or more optional embodiments above, the cross section of the first recess coplanar with the central axis of the cylindrical battery is U-shaped, trapezoidal or triangular. The first recess having a U-shaped, trapezoidal or triangular cross section is easy to shape.

[0017] In one or more of the above optional embodiments, a cross-section of the first recess coplanar with the central axis of the cylindrical battery includes a bottom edge, a first side edge, and a second side edge. The bottom edge connects the first side edge and the 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 weld portion. The angle between the first side edge and the bottom edge is α, and the angle between the second side edge and the bottom edge is β, where 88°≤α≤92° and 100°≤β≤120°.

[0018] In this embodiment, α is set to 88°-92°, making the junction between the first side and the bottom edge sharper and more prone to stress concentration near the junction. Setting β to 100°-120° also facilitates stress concentration at the junction between the first side and the bottom edge, thereby reducing the difficulty of breaking the orifice plate. While maintaining the orifice plate's cutoff pressure, the depth of the first recess can be reduced, and the minimum thickness of the portion of the orifice plate corresponding to the first recess can be increased, reducing the internal resistance of the cylindrical battery and lowering the temperature rise at the orifice plate, thereby improving the safety performance and current capacity of the cylindrical battery.

[0019] In a second aspect, the present application provides a battery module, which includes the cylindrical battery provided by any embodiment of the first aspect.

[0020] In a third aspect, the present application provides an electrical device comprising a cylindrical battery provided in any embodiment of the first aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0022] Figure 1A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0023] Figure 2 for Figure 1 A schematic front view of a cylindrical battery is shown;

[0024] Figure 3 yes Figure 2 The schematic cross-sectional view of the cylindrical battery shown is made along the TT direction;

[0025] Figure 4 for Figure 3 An enlarged schematic diagram at box E;

[0026] Figure 5 for Figure 4 An enlarged schematic diagram at box F;

[0027] Figure 6 for Figure 5 An enlarged schematic diagram at the circle;

[0028] Figure 7 A schematic bottom view of the orifice plate of a cylindrical battery provided in some embodiments of the present application along the axial direction;

[0029] Figure 8 A partial cross-sectional schematic diagram of an orifice plate of a cylindrical battery provided in some embodiments of the present application;

[0030] Figure 9 A schematic diagram of the structure of a battery module provided in some embodiments of the present application;

[0031] Figure 10 It is a structural diagram of the electrical equipment provided in some embodiments of the present application.

[0032] The reference numerals for the specific embodiments are as follows:

[0033]

[0034] DETAILED DESCRIPTION

[0035] 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.

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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 85°-95°, they are considered perpendicular; if the angle between two directions is 0°-10°, they are considered parallel.

[0040] The cylindrical battery of the present application is described below with reference to the accompanying drawings.

[0041] Reference Figures 1 to 8 , an embodiment of the present application provides a cylindrical battery 1, which can be a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery or other types of batteries.

[0042] Exemplarily, the cylindrical battery 1 is an 18650 battery, a 21700 battery, a 46800 battery, a 49480 battery, a 46950 battery or other types of cylindrical batteries.

[0043] In some embodiments, the cylindrical battery 1 is a secondary battery. After discharge, the secondary battery can be recharged to activate the active material and continue to be used.

[0044] In some embodiments, the radius of the cylindrical battery 1 is A, 8.5 mm ≤ A ≤ 27.5 mm.

[0045] As an example, A is 8.5mm, 9mm, 9.5mm, 10mm, 10.5mm, 11mm, 11.5mm, 12mm, 12.5mm, 13mm, 13.5mm, 14mm, 14.5mm, 15mm, 15.5mm, 16mm, 16.5mm, 17mm, 17.5mm, 18mm, 18.5mm, 19mm, 19.5mm, 20mm, 20.5mm, 21mm, 21.5mm, 22mm, 22.5mm, 23mm, 23.5mm, 24mm, 24.5mm, 25mm, 25.5mm, 26mm, 26.5mm, 27mm, 27.5mm or any value therebetween.

[0046] This embodiment is beneficial to improving the grouping and adaptability of the cylindrical battery 1 .

[0047] The technical solution provided in the embodiment of the present application is not only applicable to cylindrical batteries 1 with small diameters, but also to cylindrical batteries 1 with large diameters, and has a wide range of applications.

[0048] In some embodiments, the cylindrical battery 1 includes a housing 10 having a housing opening 11. Exemplarily, the housing opening 11 is provided at an end of the housing 10 along the axial direction X of the cylindrical battery 1.

[0049] In some embodiments, the shell 10 further includes a shell bottom wall 12 and a shell side wall 13. The shell bottom wall 12 is arranged opposite to the shell opening 11 along the axial direction X. The shell side wall 13 is connected to the shell bottom wall 12 and encloses the shell bottom wall 12 to form a cylindrical cavity, which is open to the outside through the shell opening 11.

[0050] The housing bottom wall 12 and the housing side wall 13 can be integrally formed. Alternatively, the housing bottom wall 12 and the housing side wall 13 can also be independently formed and connected by welding or other means.

[0051] In some embodiments, the cylindrical battery 1 further includes an electrode assembly 20, which is accommodated in the housing 10. Exemplarily, the electrode assembly 20 is accommodated in a cylindrical cavity.

[0052] In some embodiments, the electrode assembly 20 is connected to the bottom wall 12 of the housing 10 , and the housing bottom wall 12 and the electrode assembly 20 are arranged along the axial direction X. Optionally, the electrode assembly 20 and the housing bottom wall 12 are electrically connected, and the housing bottom wall 12 forms an electrode terminal of the cylindrical battery 1 , thereby eliminating a traditional electrode terminal and simplifying the structure of the cylindrical battery 1 .

[0053] 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 1, 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.

[0054] 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.

[0055] In some embodiments, the first pole piece, the diaphragm, and the second pole piece are wound together.

[0056] 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 area coated with the first active material layer and a first hollow foil area not coated with the first active material layer. The first coated area and the first hollow foil area can be arranged along the axial direction X of the cylindrical battery 1.

[0057] In some embodiments, the first empty foil region is wound into multiple turns.

[0058] In some embodiments, the first electrode sheet includes a first electrode tab, which can be formed by flattening or smoothing 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 of the electrode assembly 20, and the end of the first hollow foil region away from the first coated region is bent to form the first electrode tab.

[0059] 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 X 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.

[0060] 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 area coated with the second active material layer and a second hollow foil area not coated with the second active material layer. The second coated area and the second hollow foil area can be arranged in the axial direction X of the cylindrical battery 1.

[0061] In some embodiments, the second empty foil region is wound into multiple turns.

[0062] In some embodiments, the second electrode sheet includes a second electrode tab, which can be formed by kneading, flattening, or flattening the second hollow foil area.

[0063] In some embodiments, along the axial direction X of the cylindrical battery 1 , the first tab and the second tab are respectively located at two ends of the electrode assembly 20 .

[0064] In some embodiments, the cylindrical battery 1 includes an end cover 30 , which is connected to the housing 10 and covers the housing opening 11 .

[0065] As an example, the housing bottom wall 12 and the end cover 30 are arranged along the axial direction X of the cylindrical battery 1. The end cover 30 and the housing bottom wall 12 are respectively located on both sides of the electrode assembly 20.

[0066] The end cover 30 can close the shell opening 11 , thereby forming a relatively closed accommodation space between the shell 10 and the end cover 30 , and the accommodation space can accommodate components such as the electrode assembly 20 and the electrolyte.

[0067] In some embodiments, the housing 10 and the end cap 30 are made of steel, aluminum, alloy or other materials. The housing 10 and the end cap 30 can be made of the same or different materials.

[0068] In some embodiments, the end cap 30 is insulated from and connected to the housing side wall 13 .

[0069] In some embodiments, the first tab is connected to the end cap 30 , and the second tab is connected to the housing bottom wall 12 . The end cap 30 and the housing bottom wall 12 may serve as two electrode terminals of the cylindrical battery 1 .

[0070] In some embodiments, the cylindrical battery 1 includes an insulating structure 70, which is disposed between the end cap 30 and the housing sidewall 13. For example, the insulating structure 70 may be made of insulating rubber or ceramic.

[0071] In some embodiments, the cylindrical battery 1 includes a bursting disc 40 , which is connected to the end cap 30 .

[0072] As an example, the burst disk 40 may be connected to the end cap 30 by welding, riveting, bonding, or other suitable means.

[0073] When the air pressure inside the cylindrical battery 1 exceeds the upper limit that the explosion-proof disc 40 can withstand, the air pressure inside the cylindrical battery 1 can cause the explosion-proof disc 40 to flip and explode in a direction 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 1 due to excessive internal air pressure and improving the safety performance of the cylindrical battery 1.

[0074] In some embodiments, at least a portion of the burst disk 40 is located between the end cap 30 and the electrode assembly 20. In the axial direction X, the end cap 30 constrains the burst disk 40, thereby reducing the risk of delayed pressure relief due to excessive flipping travel.

[0075] 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 70 is provided between the burst disk 40 and the housing sidewall 13.

[0076] In some embodiments, the cylindrical battery 1 includes a perforated plate 50 , which is disposed between the explosion-proof disk 40 and the electrode assembly 20 , and the perforated plate 50 connects the electrode assembly 20 and the explosion-proof disk 40 .

[0077] In some embodiments, the orifice plate 50 is electrically connected to the electrode assembly 20. For example, the orifice plate 50 is electrically connected to the first tab or the second tab of the electrode assembly 20.

[0078] In some examples, the orifice plate 50 is directly electrically connected to the electrode assembly 20. In other examples, the orifice plate 50 is indirectly electrically connected to the electrode assembly 20 through a conductive component (eg, a current collecting plate 80 described below).

[0079] In some embodiments, the orifice plate 50 is provided with a through hole 51. The through hole 51 extends through the orifice plate 50 in the axial direction X. The through hole 51 serves as a passage for gas flow. The gas inside the cylindrical battery 1 acts on the explosion-proof disk 40 through the through hole 51, which helps reduce the risk of explosion of the cylindrical battery 1 due to excessive internal gas pressure.

[0080] In some embodiments, the cylindrical battery 1 includes a current collecting plate 80 , which is disposed between the orifice plate 50 and the electrode assembly 20 , and is connected to the orifice plate 50 and the electrode assembly 20 .

[0081] In some embodiments, a current collecting plate 80 is connected to the first electrode tab and the orifice plate 50. The end cap 30 is electrically connected to the first electrode tab via the explosion-proof disc 40, the orifice plate 50, and the current collecting plate 80. The provision of the current collecting plate 80 enables electrical connection between the end cap 30 and the electrode assembly 20, thereby improving current handling capacity and simplifying the assembly process of the cylindrical battery 1.

[0082] In some embodiments, the current collecting plate 80 is welded to the first tab.

[0083] In some embodiments, the orifice plate 50 is welded to the explosion-proof disk 40 to form an annular welding portion P. A first recess 52 is provided on a side of the orifice plate 50 facing the electrode assembly 20 , and the first recess 52 surrounds the welding portion P.

[0084] As an example, the welding portion P is provided around the central axis L of the cylindrical battery 1. The use of the annular welding portion P is beneficial to improving the uniformity of the current density distribution.

[0085] As an example, the first recess 52 is disposed around the central axis L of the cylindrical battery 1. The first recess 52 and the welding portion P may be coaxially disposed.

[0086] When the internal pressure of the cylindrical battery 1 increases, the explosion-proof disc 40 flips and deforms toward the side away from the electrode assembly 20, pulling the orifice plate 50 through the weld P, causing the orifice plate 50 to deform. When the internal pressure of the cylindrical battery 1 reaches the designed pressure value, the portion of the orifice plate 50 corresponding to the first recess 52 is broken, thereby disconnecting the current path and achieving power-off protection for the cylindrical battery 1.

[0087] In some embodiments, the cylindrical battery 1 further includes an insulating member 60. In the axial direction X, at least a portion of the insulating member 60 is located between the explosion-proof disk 40 and the orifice plate 50. The projection of the insulating member 60 along the axial direction X surrounds the projection of the first recess 52 along the axial direction X. In the radial direction of the cylindrical battery 1, the insulating member 60 is spaced a certain distance from the first recess 52. After the portion of the orifice plate 50 corresponding to the first recess 52 is severed, the insulating member 60 can separate the portion of the orifice plate 50 connected to the current collecting plate 80 from the explosion-proof disk 40, thereby disconnecting the current path.

[0088] In some embodiments, the welding method between the orifice plate 50 and the explosion-proof disk 40 includes but is not limited to laser welding, ultrasonic welding, etc.

[0089] In some embodiments, the end cap 30 , the burst disk 40 , the insulating member 60 and the orifice plate 50 are pre-assembled into an end cap assembly, which is then assembled with the housing 10 .

[0090] In some embodiments, the orifice plate 50 is a stamped part, and the first recess 52 is formed by stamping.

[0091] In some embodiments, the outer radius of the welding portion P is d, the radius of the first recess 52 is D, and 0.80≤d / D≤0.91. 0.074≤d / A≤0.086.

[0092] As an example, the projection of the welding portion P along the axial direction X is a circular ring, and d may be equal to the radius of the outer circle of the circular ring.

[0093] In some examples, the projection of the deepest point of the first recess 52 along the axial direction X is a circle, and D may be equal to the radius of the circle. In other examples, the projection of the deepest point of the first recess 52 along the axial direction X is a ring, the outer radius of the ring is r1, and the inner radius of the ring is r2, then D = (r1 + r2) / 2.

[0094] As an example, d / D is 0.8, 0.81, 0.82, 0.83, 0.84, 0.85, 0.86, 0.87, 0.88, 0.89, 0.9, 0.91, or any value therebetween.

[0095] As an example, d / A is 0.074, 0.075, 0.076, 0.077, 0.078, 0.079, 0.080, 0.081, 0.082, 0.083, 0.084, 0.085, 0.086, or any value therebetween.

[0096] When a cylindrical battery 1 experiences thermal runaway, the explosion-proof disc 40 pulls on the orifice plate 50 through the weld P, causing deformation. The stress on the orifice plate 50 is concentrated in the first recess 52. When the orifice plate 50 reaches its cutoff pressure, the explosion-proof disc 40 ruptures and flips, breaking the orifice plate 50 and disconnecting the current circuit for power-off protection. The cutoff pressure of the orifice plate 50 refers to the internal pressure of the cylindrical battery 1 when the explosion-proof disc 40 flips and the orifice plate 50 breaks, disconnecting the current circuit.

[0097] In the embodiment of the present application, d / A is set to be greater than or equal to 0.074 to increase the circumference of the weld P, improve the flow capacity and strength of the weld P, reduce the risk of cracking of the weld P when the cylindrical battery 1 is subjected to external impact, and improve the reliability of the cylindrical battery 1. In the embodiment of the present application, d / A is set to be less than or equal to 0.086. When the flow capacity and strength of the weld P meet the requirements, the welding time can be shortened, and more area for the orifice plate 50 to be provided with the through hole 51 is reserved, which facilitates exhaust.

[0098] When the cylindrical battery 1 experiences thermal runaway, the explosion-proof disc 40 flips away from the electrode assembly 20, driving the weld portion P to move away from the electrode assembly 20. As the weld portion P moves, the portion of the orifice plate 50 between the weld portion P and the first recess 52 bends and deforms, and stress is applied to the portion of the orifice plate 50 corresponding to the first recess 52. In this embodiment of the present application, the first recess 52 is positioned on the side of the orifice plate 50 facing the electrode assembly 20. This can increase stress concentration near the first recess 52 when the orifice plate 50 is subjected to tension, thereby reducing the difficulty of fracture of the orifice plate 50. This embodiment of the present application also sets d / D to be greater than or equal to 0.80, which can reduce the spacing between the first recess 52 and the weld portion P, increase the bending amplitude of the portion of the orifice plate 50 between the weld portion P and the first recess 52, and increase the stress applied to the portion of the orifice plate 50 corresponding to the first recess 52, thereby reducing the difficulty of fracture of the orifice plate 50. While maintaining the cutoff pressure of the orifice plate 50, the depth of the first recess 52 can be reduced, increasing the minimum thickness of the portion of the orifice plate 50 corresponding to the first recess 52. This reduces the internal resistance of the cylindrical battery 1 and the temperature rise at the orifice plate 50, thereby improving the safety performance and current handling capacity of the cylindrical battery 1. In this embodiment of the present application, d / D is set to be less than or equal to 0.91, and a certain distance is provided between the weld portion P and the first recess 52 in the radial direction of the cylindrical battery 1. This can reduce the heat transferred to the portion of the orifice plate 50 corresponding to the first recess 52 during welding and reduce the risk of welding to the first recess 52 due to process errors.

[0099] In some embodiments, the width W of the weld portion P is 0.2 mm to 0.4 mm. As an example, the width of the weld portion P is 0.2 mm, 0.3 mm, 0.4 mm, or any value therebetween.

[0100] As an example, the projection of the welding portion P along the axial direction X is a circular ring, and d may be equal to the width of the circular ring.

[0101] In some embodiments, 0.9 mm ≤ D ≤ 2.5 mm.

[0102] As an example, D is 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, or any value therebetween.

[0103] In the embodiment of the present application, D is set to 0.9 mm-2.5 mm, which is compatible with cylindrical batteries 1 of various specifications.

[0104] In some embodiments, 0.8 mm ≤ d ≤ 2.1 mm. For example, d is 0.8 mm, 0.9 mm, 1.0 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, or any value therebetween.

[0105] In some embodiments, a second recess 53 is defined on the side of the orifice plate 50 facing the electrode assembly 20. A bottom wall 54 of the second recess 53 is welded to the bursting disk 40 to form a weld P. A first recess 52 is defined on the side of the bottom wall 54 of the second recess 53 facing the electrode assembly 20. The bottom wall 54 of the second recess 53 includes a first weakened portion 55 corresponding to the first recess 52.

[0106] As an example, the first recess 52 is connected to the second recess 53. The bottom wall 54 of the second recess 53 has a recess bottom surface facing the electrode assembly 20. The first recess 52 and the second recess 53 are respectively located on both sides of the reference plane where the recess bottom surface is located.

[0107] The provision of the second recess 53 reduces the thickness of the bottom wall 54 of the second recess 53. Welding the bottom wall 54 of the second recess 53 to the rupture disk 40 helps reduce welding power, minimize welding heat generation, and improve welding quality. When the rupture disk 40 flips and deforms, it pulls on the bottom wall 54 of the second recess 53. The thinner bottom wall 54 of the second recess 53 is more susceptible to deformation, concentrating stress on the first weak portion 55, making it easier to break.

[0108] In some embodiments, the second recess 53 is a cylindrical recess.

[0109] In some embodiments, the first recess 52 and the second recess 53 are coaxially arranged.

[0110] In some embodiments, the thickness of the first weak portion 55 is H1, the thickness of the bottom wall 54 of the second recess 53 is H2, 0.48≤H1 / H2≤0.55, 0.15mm≤H2≤0.23mm.

[0111] As an example, H1 may be the minimum thickness of the first weak portion 55 . H2 is the thickness of the bottom wall 54 of the second recess 53 excluding the first weak portion 55 .

[0112] As an example, H1 / H2 is 0.48, 0.49, 0.50, 0.51, 0.52, 0.53, 0.54, 0.55, or any value therebetween.

[0113] As an example, H2 is 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.20 mm, 0.21 mm, 0.22 mm, 0.23 mm, or any value therebetween.

[0114] In this embodiment, H2 is set to less than or equal to 0.23 mm to reduce the difficulty of welding the bottom wall 54 of the second recess 53 to the explosion-proof disc 40. In this embodiment, H2 is set to greater than or equal to 0.15 mm to balance the strength of the bottom wall 54 of the second recess 53 and reduce the risk of cracking at the junction of the weld P and the bottom wall 54 of the second recess 53. In this application, d / D is set to greater than or equal to 0.80 to reduce the radial distance between the weld P and the first recess 52 of the cylindrical battery 1, which can reduce the difficulty of the first weak portion 55 rupturing during thermal runaway of the cylindrical battery 1. Therefore, in this embodiment, H1 / H2 can be set to greater than or equal to 0.48 to increase the flow capacity of the first weak portion 55, reduce the temperature rise at the orifice plate 50, and improve the safety performance and flow capacity of the cylindrical battery 1. In this embodiment, H1 / H2 can be set to less than or equal to 0.55 to ensure that the first weak portion 55 ruptures promptly during thermal runaway of the cylindrical battery 1, thereby disconnecting the current circuit and achieving power-off protection.

[0115] In some embodiments, 0.08 mm ≤ H1 ≤ 0.12 mm. Optionally, H1 is 0.08 mm, 0.081 mm, 0.085 mm, 0.088 mm, 0.09 mm, 0.091 mm, 0.095 mm, 0.1 mm, 0.105 mm, 0.11 mm, 0.115 mm, 0.12 mm, or any value therebetween.

[0116] In the embodiment of the present application, H1 is set to be greater than or equal to 0.08 mm, which is beneficial for increasing the flow area of ​​the first weak portion 55 and improving the flow capacity. In the embodiment of the present application, H1 is set to be less than or equal to 0.12 mm, which is beneficial for limiting the maximum strength of the first weak portion 55, reducing the risk of the first weak portion 55 failing to disconnect at the set power-off pressure value, and improving the power-off protection effect.

[0117] In some embodiments, the orifice plate 50 further includes an orifice plate body 56, which surrounds the bottom wall 54 of the second recess 53. The thickness of the orifice plate body 56 is greater than the thickness of the bottom wall 54 of the second recess 53. The orifice plate body 56 and the bottom wall 54 of the second recess 53 enclose the second recess 53.

[0118] Exemplarily, the through hole 51 is provided in the orifice plate body 56 .

[0119] In some embodiments, the thickness of the orifice plate body 56 is H5, and 2.5≤H5 / H2≤3.5.

[0120] As an example, H5 / H2 may be 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, or any value therebetween.

[0121] In this embodiment, H5 / H2 is set to be greater than or equal to 2.5, which helps reduce the maximum thickness of the bottom wall 54 of the second recess 53, reduces welding power, improves the deformation capacity of the bottom wall 54 of the second recess 53, and helps reduce the difficulty of breaking the first weak portion 55. In this embodiment, H5 / H2 is set to be less than or equal to 3.5, which helps reduce the risk of premature fracture of the orifice plate 50 if the set cut-off pressure value is not reached.

[0122] In some embodiments, in the radial direction of the cylindrical battery 1 , the minimum distance D1 between the welding portion P and the first recess 52 is greater than or equal to 0.05 mm.

[0123] In the embodiment of the present application, D1 is set to be greater than or equal to 0.05 mm, which can reduce the heat transferred to the first weak portion 55 during welding, alleviate fatigue of the first weak portion 55, and reduce the risk of welding to the first weak portion 55 due to process errors.

[0124] In some embodiments, the radius of the second concave portion 53 is B, and 1.05≤B / D≤1.45.

[0125] As an example, B / D is 1.05, 1.08, 1.10, 1.12, 1.15, 1.18, 1.20, 1.22, 1.25, 1.28, 1.30, 1.32, 1.35, 1.38, 1.40, 1.42, 1.45, or any value therebetween.

[0126] When the orifice plate 50 is pulled by the rupture disk 40, a stress concentration point is likely to form at the junction of the bottom wall 54 of the second recess 53 and the sidewall of the second recess 53. In this embodiment, setting the B / D ratio to less than or equal to 1.45 can reduce the distance between the sidewalls of the first recess 52 and the second recess 53. This increases the stress on the first weak portion 55 in the event of thermal runaway of the cylindrical battery 1, reducing the difficulty of fracturing the orifice plate 50. In this embodiment, setting the B / D ratio to greater than or equal to 1.05 can reduce the risk of unstable trip pressure values ​​caused by excessive impact of stress concentration points on the first weak portion 55, thereby improving the consistency of the trip pressure values.

[0127] In some embodiments, 1.1 mm ≤ B ≤ 3 mm.

[0128] As an example, B is 1.1 mm, 1.15 mm, 1.2 mm, 1.25 mm, 1.3 mm, 1.35 mm, 1.4 mm, 1.45 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.9 mm, 2.0 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3.0 mm or any value therebetween.

[0129] In some embodiments, BD≥0.1 mm. This embodiment can reduce the risk of unstable off-state pressure value caused by excessive influence of stress concentration point on the first weak portion 55, and improve the consistency of off-state pressure value.

[0130] In some embodiments, in the axial direction of the cylindrical battery 1 , the size of the portion of the weld P formed on the explosion-proof disc 40 is H3, and the thickness of the explosion-proof disc 40 is H4. 0.2≤H3 / H4≤0.54, 0.3mm≤H4≤0.4mm.

[0131] As an example, H3 / H4 is 0.2, 0.22, 0.25, 0.28, 0.3, 0.32, 0.35, 0.38, 0.4, 0.42, 0.43, 0.44, 0.45, 0.48, 0.5, 0.52, 0.54 or any value therebetween.

[0132] As an example, H4 is 0.3 mm, 0.32 mm, 0.34 mm, 0.35 mm, 0.36 mm, 0.38 mm, 0.4 mm, or any value therebetween.

[0133] In this embodiment, H3 / H4 is set to be greater than or equal to 0.2, which helps increase the dimension of the portion of the weld portion P formed on the burst disk 40 in the axial direction X, thereby enhancing the connection reliability between the weld portion P and the burst disk 40 and improving the flow capacity between the weld portion P and the burst disk 40. In this embodiment, H3 / H4 is set to be less than or equal to 0.54, which not only reduces the impact of the weld portion P on the burst disk 40, but also helps reduce the difficulty of welding the burst disk 40 to the orifice plate 50, thereby improving welding efficiency.

[0134] In some embodiments, 0.1 mm ≤ H3 ≤ 0.25 mm. For example, H3 is 0.1 mm, 0.12 mm, 0.13 mm, 0.15 mm, 0.16 mm, 0.18 mm, 0.2 mm, 0.22 mm, 0.23 mm, 0.25 mm, or any value therebetween.

[0135] In some embodiments, the cross section of the first recess 52 coplanar with the central axis L of the cylindrical battery 1 is U-shaped, trapezoidal, or triangular. The first recess 52 having a U-shaped, trapezoidal, or triangular cross section is easy to shape.

[0136] In some embodiments, the cross-section of the first recess 52 that is coplanar with the central axis L of the cylindrical battery 1 includes a bottom edge 523a, a first side edge 521a, and a second side edge 522a. The bottom edge 523a connects the first side edge 521a and the second side edge 522a. In the radial direction of the cylindrical battery 1, the second side edge 522a is located on the side of the first side edge 521a away from the welding portion P.

[0137] The cross section of the first recess 52 coplanar with the central axis L of the cylindrical battery 1 refers to a cross section taken along a cutting plane passing through the central axis L of the cylindrical battery 1. As an example, the cross section of the first recess 52 coplanar with the central axis L of the cylindrical battery 1 is a trapezoid.

[0138] In some embodiments, the first side 521a and the second side 522a are both straight edges.

[0139] In some embodiments, the first recess 52 includes a first side surface 521 , a second side surface 522 , and a bottom surface 523 . The bottom surface 523 connects the first side surface 521 and the second side surface 522 . The second side surface 522 surrounds the first side surface 521 .

[0140] The intersection line of any reference plane passing through the central axis L and the first side surface 521 is the first side edge 521a, the intersection line of the reference plane passing through the central axis L and the second side surface 522 is the second side edge 522a, and the intersection line of the reference plane passing through the central axis L and the bottom surface 523 is the bottom edge 523a.

[0141] In some embodiments, the bottom surface 523 is a circular plane.

[0142] In some embodiments, the first weak portion 55 includes a portion of the orifice plate 50 corresponding to the bottom surface 523 .

[0143] In some embodiments, the connection between the first side surface 521 and the bottom surface 523 is transitioned through a rounded corner, and the connection between the second side surface 522 and the bottom surface 523 is transitioned through a rounded corner.

[0144] In some embodiments, the angle between the first side 521a and the bottom 523a is α, the angle between the second side 522a and the bottom 523a is β, and 88°≤α≤92°, 100°≤β≤120°.

[0145] As an example, α is 88°, 89°, 90°, 91°, 92°, or any value therebetween.

[0146] As an example, β is 100°, 102°, 105°, 108°, 110°, 112°, 115°, 118°, 120°, or any value therebetween.

[0147] In this embodiment, α is set to 88°-92°, making the connection between the first side 521a and the bottom 523a more acute, and stress concentration is more likely to occur near the connection between the first side 521a and the bottom 523a. Setting β to 100°-120° can also make stress more likely to concentrate at the connection between the first side 521a and the bottom 523a, thereby reducing the difficulty of breaking the orifice plate 50. When the cutoff pressure value of the orifice plate 50 remains unchanged, the depth of the first recess 52 can be reduced, and the minimum thickness of the portion of the orifice plate 50 corresponding to the first recess 52 can be increased, thereby reducing the internal resistance of the cylindrical battery 1 and the temperature rise at the orifice plate 50, thereby improving the safety performance and overcurrent capacity of the cylindrical battery 1.

[0148] In some embodiments, the burst disk 40 includes a pressure relief portion 41 and a second weakened portion 42 . The second weakened portion 42 extends along the periphery of the pressure relief portion 41 .

[0149] The second weak portion 42 is a portion of the bursting disc 40 that is easily ruptured, and the bursting disc 40 releases pressure by rupturing the second weak portion 42. Optionally, the second weak portion 42 is thinner than the pressure relief portion 41, so that it is easier to rupture than the pressure relief portion 41.

[0150] In some embodiments, the second weak portion 42 is an arc-shaped structure disposed on the periphery of the pressure relief portion 41. In other words, the two ends of the second weak portion 42 are not connected to form a non-enclosed structure. In other embodiments, the second weak portion 42 is an annular closed structure surrounding the pressure relief portion 41.

[0151] In some embodiments, the bursting disc 40 includes a connecting portion 43, and a second weak portion 42 connects the pressure relief portion 41 and the connecting portion 43. The connecting portion 43 is connected to the end cap 30 to enhance the restraining effect of the end cap 30 on the bursting disc 40, facilitating the flipping and pressure relief of the bursting disc 40.

[0152] In some embodiments, the pressure relief portion 41 includes a main body 411 and a protrusion 412. The protrusion 412 protrudes from the surface of the main body 411 facing the orifice plate 50. The protrusion 412 is welded to the orifice plate 50 to form a weld P. A gap is formed between the main body 411 and the orifice plate 50, and the through hole 51 of the orifice plate 50 is connected to the gap.

[0153] In some embodiments, along the axial direction X of the cylindrical battery 1 , the projection of the bottom wall 54 of the second recess 53 and the projection of the convex portion 412 at least partially overlap. Optionally, the projection of the bottom wall 54 of the second recess 53 is located within the projection of the convex portion 412 .

[0154] In some embodiments, the insulating member 60 is disposed around the protrusion 412. Along the radial direction of the cylindrical battery 1, the insulating member 60 and the protrusion 412 are spaced apart. Along the axial direction X of the cylindrical battery 1, the insulating member 60 is clamped between the orifice plate 50 and the explosion-proof disk 40.

[0155] In some embodiments, along the axial direction X of the cylindrical battery 1 , the projection of the insulating member 60 and the projection of the through hole 51 are separated, which helps to reduce the blocking effect of the insulating member 60 on the exhaust air flow.

[0156] The convex portion 412 protrudes from the main body 411 in the direction close to the orifice plate 50, which not only facilitates the welding of the convex portion 412 and the orifice plate 50, but also forms a gap between the main body 411 and the orifice plate 50. The gas discharged through the through hole 51 acts on the main body 411 through the gap, which is conducive to the main body 411 flipping and deforming in the direction away from the orifice plate 50, thereby smoothly blasting and releasing pressure.

[0157] According to the second aspect of this application, referring to Figure 9 , an embodiment of the present application further provides a battery module 1000, the battery module 1000 including a plurality of cylindrical batteries 1 provided according to any embodiment of the present application.

[0158] In some embodiments, the battery module 1000 further includes a plurality of busbars that connect the cylindrical batteries 1. At least two cylindrical batteries 1 can be connected in series or in parallel via the busbars.

[0159] According to the third aspect of this application, referring to Figure 10 The embodiment of the present application further provides an electric device 2000, which includes the battery module 1000 provided in any embodiment of the present application. The battery module 1000 can provide power to the electric device 2000.

[0160] The electrical device 2000 of the present embodiment may be a portable device, an electric toy, a drone, a power tool, an energy storage system, or the like. Power tools include metal cutting power tools and cleaning tools, such as electric drills, electric wrenches, vacuum cleaners, and robot vacuums. The present embodiment does not impose any particular restrictions on the electrical device 2000.

[0161] Example

[0162] The following examples describe the contents disclosed in the examples of the present application in more detail. These examples are only used for illustrative purposes, because it is obvious to those skilled in the art that various modifications and changes are made within the scope of the contents disclosed in the examples of the present application.

[0163] Example 1

[0164] <Cylindrical Battery Preparation>

[0165] The steel shell 10 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 50, and then the assembly consisting of the end cover 30, the explosion-proof plate 40, the orifice plate 50 and other structures is inserted into the shell 10, and the sealing is performed to obtain a cylindrical battery 1 with a specification of 21700 for testing (there is no electrode assembly in the shell); a circular hole with a diameter of 5 mm is drilled at the bottom of the shell 10 of the cylindrical battery 1 using a drilling device.

[0166] Among them, the radius A of the cylindrical battery 1 is 10.5 mm, the outer radius d of the weld P is 0.9 mm, the width W of the weld P is 0.3 mm, the radius D of the first recess 52 is 1 mm, the radius B of the second recess 53 is 1.35 mm, the thickness H1 of the first weak portion 55 is 0.09 mm, the thickness H2 of the bottom wall 54 of the second recess 53 is 0.17 mm, the thickness H5 of the orifice plate body 56 is 0.5 mm, the thickness H4 of the explosion-proof disk 40 is 0.3 mm, and the size H3 (i.e., the penetration depth H3) of the portion of the weld P formed on the explosion-proof disk 40 is 0.13 mm.

[0167] Example 2: The preparation method of the cylindrical battery is consistent with that of Example 1, and the differences are shown in Table 1.

[0168] Example 3: The preparation method of the cylindrical battery is consistent with that of Example 1, and the differences are shown in Table 1.

[0169] Example 4: The preparation method of the cylindrical battery is consistent with that of Example 1, and the differences are shown in Table 1.

[0170] Comparative Example 1: The preparation method of the cylindrical battery is consistent with that of Example 1, and the differences are shown in Table 1.

[0171] Comparative Example 2: The preparation method of the cylindrical battery is consistent with that of Example 1, and the differences are shown in Table 1.

[0172] Power-off stress test

[0173] The cylindrical batteries prepared in each embodiment and comparative example were subjected to the following tests:

[0174] <External circuit>

[0175] The two magnetic terminals are respectively adsorbed on the end cover 30 and the housing 10 to form a loop, and the loop current is monitored by a current sensor.

[0176] <Explosion Test>

[0177] 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 0.05 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 10 when the circuit is disconnected).

[0178] Test results

[0179] The test results are shown in Table 1.

[0180] Table 1

[0181]

[0182] With reference to Examples 1-4 and Comparative Example 1-2, setting d / A within the range of 0.075-0.086 and d / D within the range of 0.8-0.91 can reduce the difficulty of breaking the orifice plate 50. Specifically, with reference to Examples 1-2 and Comparative Example 1, Example 1-2 increases the outer radius d of the weld P to increase the values ​​of d / A and d / D. When the power-off design pressure of the orifice plate 50 is 1.15 MPa, the first weak portion 55 of Example 1-2 can have a greater thickness, thereby reducing the internal resistance of the cylindrical battery 1 and lowering the temperature rise at the orifice plate 50, thereby improving the safety performance and current capacity of the cylindrical battery 1. Referring to Examples 3-4 and Comparative Example 2, in Example 3-4, the outer radius d of the welding portion P is increased to increase the value of d / A and the value of d / D. When the power-off design pressure of the orifice plate 50 is 0.95 MPa, the first weak portion 55 of Example 3-4 can have a larger thickness, thereby reducing the internal resistance of the cylindrical battery 1 and reducing the temperature rise at the orifice plate 50, thereby improving the safety performance and overcurrent capacity of the cylindrical battery 1.

[0183] 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 an annular weld portion, the orifice plate having a first recessed portion on a side facing the electrode assembly, the first recessed portion surrounding the weld portion; The outer radius of the welding portion is d, the radius of the first recess is D, and 0.80≤d / D≤0.91; The radius of the cylindrical battery is A, 0.074≤d / A≤0.086, 8.5mm≤A≤27.5mm.

2. The cylindrical battery according to claim 1, characterized in that: 0.9mm≤D≤2.5mm.

3. The cylindrical battery according to claim 1, characterized in that A second recess is provided on a side of the orifice plate facing the electrode assembly, a bottom wall of the second recess is welded to the explosion-proof disk to form the weld, and the first recess is provided on a side of the bottom wall of the second recess facing the electrode assembly; 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, the thickness of the bottom wall of the second recess is H2, 0.48≤H1 / H2≤0.55, 0.15mm≤H2≤0.23mm.

4. The cylindrical battery according to any one of claims 1 to 3, characterized in that: In the radial direction of the cylindrical battery, a minimum distance D1 between the welding portion and the first recess is greater than or equal to 0.05 mm.

5. The cylindrical battery according to any one of claims 1 to 4, characterized in that: A second recess is provided on a side of the orifice plate facing the electrode assembly, a bottom wall of the second recess is welded to the explosion-proof disk to form the weld, and the first recess is provided on a side of the bottom wall of the second recess facing the electrode assembly; The radius of the second concave portion is B, and 1.05≤B / D≤1.

45.

6. The cylindrical battery according to any one of claim 5, characterized in that: BD≥0.1mm.

7. The cylindrical battery according to any one of claims 1 to 6, 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, 0.3mm≤H4≤0.4mm.

8. The cylindrical battery according to any one of claims 1 to 7, characterized in that: The cross section of the first recessed portion coplanar with the central axis of the cylindrical battery is U-shaped, trapezoidal or triangular.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: A cross section of the first recessed portion coplanar with the central axis of the cylindrical battery includes a bottom edge, a first side edge, and a second side edge, wherein the bottom edge connects the first side edge and the second side edge, and 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 bottom is α, the angle between the second side and the bottom is β, 88°≤α≤92°, 100°≤β≤120°.

10. A battery module, characterized in that: The invention comprises a cylindrical battery according to any one of claims 1 to 9.

11. An electrical device, characterized in that: The invention comprises a cylindrical battery according to any one of claims 1 to 9.

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