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 assembly and a first insulating part, the shell comprises a bottom wall and a side wall, the side wall comprises a side wall main body and a bending part, the side wall main body is connected to the bottom wall, and the bending part extends from one end, far away from the bottom wall, of the side wall main body and is bent towards an axis; the end cover assembly and the bottom wall are arranged in the axial direction, the end cover assembly and the side wall are insulated and connected, and in the axial direction, part of the bending part is located on the side, back to the bottom wall, of the end cover assembly; the first insulating part comprises a first insulating part and a plurality of limiting parts, one part of the first insulating part is arranged between the bending part and the end cover assembly, and in the radial direction, one of the limiting parts covers at least one part of the end face, facing the axis, of the bending part and is connected to the end face; therefore, the corrosion resistance of the bending part is improved, and the anti-seismic property of the cylindrical battery is improved.

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 seismic resistance and corrosion resistance 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 shock resistance and corrosion resistance 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 cap assembly and a first insulating member, the shell includes a bottom wall and a side wall, the side wall includes a side wall body and a bending portion, the side wall body is connected to the bottom wall, and the bending portion extends from one end of the side wall body away from the bottom wall and bends toward the axis of the cylindrical battery; the electrode assembly is accommodated in the shell; the end cap assembly and the bottom wall are arranged along the axial direction of the cylindrical battery, the end cap assembly is insulated and connected to the side wall, in the axial direction, part of the bending portion is located on the side of the end cap assembly facing away from the bottom wall, and the shell and the end cap assembly have different polarities; the first insulating member includes a first insulating portion and a plurality of limiting portions provided on the first insulating portion, the first insulating portion is provided on the side of the end cap assembly facing the bending portion, a portion of the first insulating portion is provided between the bending portion and the end cap assembly, the plurality of limiting portions are arranged along the radial direction of the cylindrical battery, and in the radial direction, one of the limiting portions covers at least a portion of the end face of the bending portion facing the axis and is connected to the end face.

[0006] One of the multiple limiting portions radially covers at least a portion of the end face of the bent portion facing the axis and is connected to the end face. On the one hand, when the cylindrical battery is impacted or falls, the limiting portion can limit the bent portion in the radial direction, reducing the risk of deformation of the bent portion, thereby reducing the risk of relative displacement between the bent portion and the first insulating portion causing a leakage gap, helping to improve the sealing effect of the first insulating member and the shock resistance of the cylindrical battery. On the other hand, the limiting portion can also protect at least a portion of the end face of the bent portion facing the axis, helping to improve the corrosion resistance of at least a portion of the end face of the bent portion facing the axis. In addition, the limiting portion covering at least a portion of the end face of the bent portion facing the axis can also play a sealing role to a certain extent, which helps to extend the sealing path between the first insulating member and the bent portion, thereby improving the sealing effect of the first insulating member.

[0007] In one or more of the above optional embodiments, the limiting portion protrudes from the surface of the first insulating portion facing away from the end cover assembly along the direction of the bottom wall pointing to the end cover assembly. Therefore, in the radial direction, one side surface of a limiting portion can cover at least a portion of the end face of the bending portion facing the axis, and press against the end face, thereby achieving limitation of the bending portion.

[0008] In one or more of the above optional embodiments, among the multiple limiting portions, the axial height of the limiting portion closest to the axis is greater than the axial heights of the other limiting portions.

[0009] In the axial direction, the limiting portion closest to the axis can protrude relative to the other limiting portions. When the cylindrical battery is impacted or falls, the limiting portion closest to the axis can provide additional support in the axial direction, which helps to disperse the axial load on other limiting portions and the bending portion, and reduce the risk of deformation of other limiting portions and the bending portion in the axial direction due to excessive load.

[0010] In one or more of the above optional embodiments, at least one of the plurality of limiting portions protrudes from the surface of the bending portion facing away from the end cover assembly along the direction of the bottom wall pointing toward the end cover assembly.

[0011] When a cylindrical battery is impacted or dropped, the limiting portion not only provides radial support for the bent portion but also distributes the load axially, thereby reducing the risk of deformation of the bent portion due to excessive axial load. Furthermore, by providing at least one of the multiple limiting portions protruding from the surface of the bent portion facing away from the end cap assembly, the contact area between the limiting portion and the end surface of the bent portion facing the axis is increased, allowing the limiting portion to cover the entire end surface of the bent portion facing the axis, thereby enhancing the limiting portion's radial limiting effect on the bent portion and its protective effect on the end surface of the bent portion facing the axis.

[0012] In one or more of the above optional embodiments, in the radial direction, gaps are provided between adjacent limiting portions.

[0013] The provision of this gap provides a certain amount of buffer space for each stopper in the radial direction. When the cylindrical battery is impacted or dropped, the gap can absorb radial loads to a certain extent, thereby improving the restraint effect on the bend. Furthermore, the provision of the gap can reduce the risk of structural resonance and friction loss in the stopper when the stopper undergoes slight deformation due to external forces, thereby reducing the mutual interference and influence between two adjacent stoppers.

[0014] In one or more of the above optional embodiments, the radial dimension of the gap is smaller than the axial dimension of the limiting portion, so as to reasonably design the size of the gap and reduce the impact of the gap setting on the radial dimension of the cylindrical battery while improving the buffering capacity of the gap.

[0015] In one or more optional embodiments above, the multiple limiting portions include a first limiting portion; the first limiting portion includes a first part and a second part, the first part connecting the first insulating portion and the second part; in the radial direction, the first part covers the end face of the bending portion close to the axis and is connected to the end face; in the axial direction, at least part of the second part is arranged on the side of the bending portion away from the electrode assembly.

[0016] The first part can limit the bent portion in the radial direction, reducing the risk of deformation of the bent portion. In addition, the first part can also provide protection for at least part of the end face of the bent portion facing the axis, reducing the risk of corrosion and other conditions on the end face of the bent portion facing the axis. The second part can provide insulation and protection for the bent portion on the side of the bent portion facing away from the electrode assembly. When multiple cylindrical batteries are connected by a busbar, the second part can be located axially between the busbar and the bent portion to act as an insulator and buffer, reducing the risk of short circuit caused by contact between the busbar and the bent portion.

[0017] In one or more optional embodiments above, the multiple limiting portions also include a second limiting portion arranged adjacent to the first limiting portion, and the second limiting portion is located on the side of the first limiting portion close to the axis; the second limiting portion is inclined toward the side close to the first limiting portion.

[0018] When the cylindrical battery is impacted or falls, the inclined second limiting portion can effectively decompose the axial and radial loads, providing good support and restraint for the first limiting portion and the bending portion.

[0019] In one or more of the above optional embodiments, one end of the second limiting portion is connected to the first insulating portion, and the other end contacts a surface of the first limiting portion near the axis. The second limiting portion, the first limiting portion, and the first insulating portion can form a stable triangular structure, which helps to improve the restraining effect of the first and second limiting portions on the bent portion.

[0020] In one or more optional embodiments above, the first insulating member further includes an insulating protrusion, which protrudes from the side of the first insulating member facing the end cover assembly; the end cover assembly includes an end cover and an explosion-proof disk, the end cover includes an end cover body and an end cover protrusion, and in the axial direction, the end cover protrusion protrudes away from the electrode assembly relative to the end cover body; the explosion-proof disk includes an explosion-proof disk body and a connecting portion, the explosion-proof disk body is provided on the side of the end cover facing the electrode assembly, and the connecting portion is provided on the side of the end cover body away from the electrode assembly, and in the radial direction, at least a portion of the insulating protrusion is located between the connecting portion and the end cover protrusion.

[0021] The insulating protrusion acts as a buffer between the connecting portion and the end cap protrusion, reducing the risk of interference between the connecting portion and the end cap protrusion under external forces. Furthermore, the connecting portion and the end cap protrusion radially clamp the insulating protrusion to limit its position. This, in turn, limits the position of the first insulating portion and the limiting portion through the insulating protrusion, thereby reducing the risk of the first insulating portion and the limiting portion shifting relative to the bent portion, thereby improving the stability of the first insulating member and its sealing effectiveness.

[0022] In one or more optional embodiments above, the minimum thickness of the first insulating portion is H1; in the axial direction, the height of the insulating protrusion is H2; and 0<H2≤0.5H1.

[0023] Set H2 to be greater than 0 and less than or equal to 0.5H1 to reasonably set the relationship between the minimum thickness of the first insulating part and the height of the insulating protrusion, thereby improving the structural strength of the insulating protrusion while improving the insulation effect and sealing effect of the first insulating part, thereby improving the stability of the first insulating part.

[0024] In one or more of the above optional embodiments, the limiting portion includes a recessed portion recessed from a surface of the first insulating portion facing away from the end cap assembly. An end of the bent portion facing the axis may be disposed within the recessed portion, and a portion of an inner wall of the recessed portion may cover at least a portion of an end surface of the bent portion facing the axis, thereby limiting the position of the bent portion via the inner wall of the recessed portion.

[0025] In one or more of the above optional embodiments, among the multiple limiting portions, the recessed portion of the limiting portion closest to the axis has a greater axial depth than the recessed portions of the other limiting portions. Because the recessed portion of the limiting portion closest to the axis has the greatest depth, it has the best limiting effect and strength. When the recessed portions of the other limiting portions fail under external forces, the limiting portion closest to the axis can provide a backup constraint for the bent portion, reducing the risk of continued deformation of the bent portion.

[0026] In one or more of the above optional embodiments, the minimum thickness of the first insulating portion is H1, the thickness of the bent portion is H3, and 0.1mm≤H1-H3≤0.5mm. This helps increase the thickness of the first insulating portion, improve the strength of the first insulating portion, and thus improve the insulation and sealing capabilities of the first insulating portion. It also helps reduce the impact of the first insulating portion on the size of the cylindrical battery. And / or, 0.2mm≤H3≤0.5mm. This helps increase the strength of the bent portion and reduce the risk of deformation of the bent portion under external force, thereby reducing the risk of relative displacement between the bent portion and the first insulating portion causing leakage gaps, improving the sealing effect of the first insulating member, and also helps reduce the impact of the bent portion on the radial size of the cylindrical battery.

[0027] In one or more of the above optional embodiments, the limiting portion is arranged around the circumference of the cylindrical battery, and one of the limiting portions can cover at least a portion of the end surface of the bent portion facing the axis in the circumferential direction, thereby limiting and protecting the bent portion in the circumferential direction, and can also provide a sealing and corrosion-resistant effect in the circumferential direction. Alternatively, the limiting portion includes multiple sub-portions, and the multiple sub-portions are arranged at intervals along the circumference of the cylindrical battery. The multiple sub-portions can cover multiple areas of the end surface of the bent portion facing the axis in the circumferential direction to improve the limiting and protection effects of the bent portion.

[0028] 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.

[0029] 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

[0030] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0031] Figure 1 A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0032] Figure 2 for Figure 1 A schematic cross-sectional view of a cylindrical battery is shown;

[0033] Figure 3 for Figure 1 Another schematic cross-sectional view of a cylindrical battery shown;

[0034] Figure 4 for Figure 2 A partial enlarged view of the middle circle;

[0035] Figure 5 for Figure 3A partial enlarged view of the middle circle;

[0036] Figure 6 for Figure 1 A schematic cross-sectional view of a first insulating member of a cylindrical battery shown;

[0037] Figure 7 for Figure 1 A cross-sectional view of the cylindrical battery after the first insulating member and the end cap assembly are assembled;

[0038] Figure 8 for Figure 1 Another cross-sectional schematic diagram of the first insulating member of the cylindrical battery shown

[0039] Figure 9 A schematic diagram of a battery module provided in some embodiments of the present application;

[0040] Figure 10 Schematic diagram of electrical equipment provided in some embodiments of the present application.

[0041] The reference numerals for the specific embodiments are as follows:

[0042] Cylindrical battery 1000; box 2000; battery module 3000; electrical equipment 4000;

[0043] Electrode assembly 1; shell 2; bottom wall 21; side wall 22; side wall body 221; bending portion 222; end face 2221; end cap assembly 3; end cap 31; end cap body 311; end cap protrusion 312; explosion-proof disk 32; explosion-proof disk body 321; connecting portion 322; first insulating member 4; first insulating portion 41; limiting portion 42; first limiting portion 421; first part 4211; second part 4212; second limiting portion 422; recess 423; insulating protrusion 43; second insulating member 5; insulating film 6; radial direction X; axial direction Z; axis S; gap K1. DETAILED DESCRIPTION

[0044] 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.

[0045] 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.

[0046] 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.

[0047] 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.

[0048] 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.

[0049] The cylindrical battery, battery module and electrical equipment of the present application are described below with reference to the accompanying drawings.

[0050] Reference Figures 1 to 8 , an embodiment of the present application provides a cylindrical battery 1000.

[0051] 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.

[0052] The cylindrical battery 1000 may be a 21700 battery, an 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries 1000 .

[0053] 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.

[0054] In some embodiments, the cylindrical battery 1000 includes a housing 2 and an electrode assembly 1 housed in the housing 2 .

[0055] In some embodiments, the electrode assembly 1 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.

[0056] In some embodiments, the electrode assembly 1 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.

[0057] In some embodiments, the first pole piece, the diaphragm, and the second pole piece are wound together.

[0058] 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.

[0059] In some embodiments, the first empty foil region is wound into multiple turns.

[0060] 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 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.

[0061] In other embodiments, the first electrode tab can be formed by flattening the first empty foil area. For example, the first empty foil area is squeezed in the axial direction Z of the electrode assembly 1 from the side of the first empty foil area away from the first coated area, and the end of the first empty foil area away from the first coated area is bent to form the first electrode tab.

[0062] 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.

[0063] In some embodiments, the second empty foil region is wound into multiple turns.

[0064] In some embodiments, the second electrode sheet includes a second electrode tab, which can be formed by flattening or smoothing 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.

[0065] In other embodiments, the second electrode tab can be formed by flattening the second hollow foil area. For example, the second hollow foil area is squeezed in the axial direction Z of the electrode assembly 1 from the side of the second hollow foil area away from the second coated area, and the end of the second hollow foil area away from the second coated area is bent to form the second electrode tab.

[0066] 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 1 .

[0067] In some embodiments, one end of the housing 2 along the axial direction Z is provided with a housing opening.

[0068] In some embodiments, the housing 2 includes a bottom wall 21 and a side wall 22. The side wall 22 is connected to the bottom wall 21 and surrounds the electrode assembly 1. An end of the side wall 22 away from the bottom wall 21 along the axial direction Z forms a housing opening.

[0069] The bottom wall 21 and the side wall 22 can be integrally formed. Alternatively, the bottom wall 21 and the side wall 22 can also be independently formed and connected by welding or other means.

[0070] In some embodiments, cylindrical battery 1000 includes an end cap assembly 3, which is connected to housing 2 and covers the housing opening. End cap assembly 3 can close the housing opening, thereby forming a relatively closed accommodation space between housing 2 and end cap assembly 3, which can accommodate components such as electrode assembly 1 and electrolyte.

[0071] In some embodiments, the bottom wall 21 and the end cap assembly 3 are arranged along the axial direction Z of the cylindrical battery 1000. The end cap assembly 3 and the bottom wall 21 are respectively located on both sides of the electrode assembly 1.

[0072] In some embodiments, the sidewall 22 includes a sidewall body 221 and a bent portion 222. The sidewall body 221 is connected to the bottom wall 21. The bent portion 222 extends from one end of the sidewall body 221 away from the bottom wall 21 and bends toward the axis S of the cylindrical battery 1000. In the axial direction Z, a portion of the bent portion 222 can be located on the side of the end cap assembly 3 away from the bottom wall 21, thereby exerting a certain restraining effect on the end cap assembly 3 in the axial direction Z and improving the stability of the end cap assembly 3.

[0073] In some embodiments, the bent portion 222 extends in a ring shape along the circumference of the cylindrical battery 1000 to improve the limiting effect on the end cap assembly 3.

[0074] In some embodiments, the end cap assembly 3 is insulated from and connected to the side wall 22 .

[0075] In some embodiments, the housing 2 and the end cap assembly 3 have different polarities. For example, one of the housing 2 and the end cap assembly 3 has a positive polarity and the other has a negative polarity.

[0076] In some embodiments, the first tab is connected to the end cap assembly 3 , and the second tab is connected to the bottom wall 21 .

[0077] In some embodiments, the cylindrical battery 1000 further includes a first insulating member 4, which includes a first insulating portion 41. The first insulating portion 41 is disposed on the side of the end cap assembly 3 facing the bent portion 222, with a portion of the first insulating portion 41 disposed between the bent portion 222 and the end cap assembly 3. On the one hand, the provision of the first insulating portion 41 can be used to insulate the bent portion 222 and the end cap assembly 3, reducing the risk of a short circuit between the end cap assembly 3 and the sidewall 22. On the other hand, the first insulating portion 41 can also provide a seal between the bent portion 222 and the end cap assembly 3, reducing the risk of leakage and corrosion in the cylindrical battery 1000.

[0078] In some embodiments, the first insulating member 4 further includes a plurality of limiting portions 42 provided on the first insulating portion 41, and the plurality of limiting portions 42 are arranged along the radial direction X of the cylindrical battery 1000. In the radial direction X, one of the limiting portions 42 covers at least a portion of the end face 2221 of the bending portion 222 facing the axis S and is connected to the end face 2221.

[0079] The limiting portion 42 may be integral with the first insulating portion 41 or may be separate and connected to the first insulating portion 41. The limiting portion 42 may protrude relative to the first insulating portion 41 or may be recessed relative to the first insulating portion 41.

[0080] In an embodiment of the present application, one of the multiple limiting portions 42 covers at least a portion of the end face 2221 of the bent portion 222 facing the axis S in the radial direction X and is connected to the end face 2221. On the one hand, when the cylindrical battery 1000 is impacted or falls, the limiting portion 42 can limit the bent portion 222 in the radial direction X, reducing the risk of deformation of the bent portion 222, and thereby reducing the risk of relative displacement between the bent portion 222 and the first insulating portion 41 and generating a leakage gap, thereby helping to improve the sealing effect of the first insulating member 4. On the other hand, the limiting portion 42 can also protect at least a portion of the end face 2221 of the bent portion 222 facing the axis S, thereby helping to improve the corrosion resistance of at least a portion of the end face 2221 of the bent portion 222 facing the axis S. In addition, the limiting portion 42 covering at least part of the end surface 2221 of the bending portion 222 facing the axis S can also play a sealing role to a certain extent, which helps to extend the sealing path between the first insulating member 4 and the bending portion 222 and improve the sealing effect of the first insulating member 4.

[0081] Moreover, in the embodiment of the present application, a plurality of limiting portions 42 can realize graded limiting of the bending portion 222. When the limiting effect of the limiting portion 42 covering the end face 2221 of the bending portion 222 facing the axis S is reduced or fails under the action of external force, the other limiting portions 42 located on the side of the limiting portion 42 close to the axis S can provide backup constraints for the bending portion 222, which helps to improve the fault tolerance capability of each limiting portion 42 in limiting the bending portion 222.

[0082] In addition, in the embodiment of the present application, a plurality of limiting portions 42 are arranged along the radial direction X of the cylindrical battery 1000, so that the bent portion 222 of the cylindrical battery 1000 can be selectively pressed against one of the limiting portions 42 according to actual conditions, which helps to improve the flexibility of assembly of the cylindrical battery 1000.

[0083] In some embodiments, the limiting portion 42 protrudes from the surface of the first insulating portion 41 facing away from the end cover assembly 3 .

[0084] The limiting portion 42 is a convex portion protruding from the side surface of the first insulating portion 41 facing away from the end cover assembly 3. In the radial direction X, one side surface of the limiting portion 42 can cover at least a portion of the end surface 2221 of the bending portion 222 facing the axis S, and press against the end surface 2221, thereby achieving the limitation of the bending portion 222.

[0085] In some embodiments, among the plurality of limiting portions 42 , the height of the limiting portion 42 closest to the axis S along the axial direction Z is greater than the heights of the other limiting portions 42 along the axial direction Z.

[0086] In the axial direction Z, the limiting portion 42 closest to the axis S can protrude relative to the other limiting portions 42. When the cylindrical battery 1000 is impacted or falls, the limiting portion 42 closest to the axis S can provide additional support in the axial direction Z, which helps to disperse the axial load on other limiting portions 42 and the bending portion 222, and reduce the risk of deformation of other limiting portions 42 and the bending portion 222 in the axial direction Z due to excessive load.

[0087] In some embodiments, of two adjacent limiting portions 42 , the height of the limiting portion 42 closer to the axis S in the radial direction X may be greater than the height of the limiting portion 42 farther from the axis S. The height difference between the plurality of limiting portions 42 helps to improve the effect of graded limiting of the bent portion 222 .

[0088] In some embodiments, at least one of the plurality of limiting portions 42 protrudes from a surface of the bent portion 222 facing away from the end cover assembly 3 along a direction from the bottom wall 21 toward the end cover assembly 3 .

[0089] When the cylindrical battery 1000 is impacted or falls, the limiting portion 42 can not only provide support for the bending portion 222 in the radial direction X, but also disperse the load for the bending portion 222 in the axial direction Z, thereby reducing the risk of deformation of the bending portion 222 due to excessive axial load.

[0090] Moreover, in the embodiment of the present application, at least one of the multiple limiting portions 42 is provided to protrude from the surface of the bending portion 222 facing away from the end cover assembly 3, which can also increase the contact area between the limiting portion 42 and the end surface 2221 of the bending portion 222 facing the axis S, so that the limiting portion 42 covers the entire end surface 2221 of the bending portion 222 facing the axis S, thereby helping to improve the radial limiting effect of the limiting portion 42 on the bending portion 222 and the protective effect on the end surface 2221 of the bending portion 222 facing the axis S.

[0091] In an embodiment of the present application, in the direction in which the bottom wall 21 points to the end cover assembly 3, a portion of the multiple limiting portions 42 may protrude from the surface of the bending portion 222 facing away from the end cover assembly 3, or all of the multiple limiting portions 42 may protrude from the surface of the bending portion 222 facing away from the end cover assembly 3.

[0092] In some embodiments, in the radial direction X, a gap K1 is provided between adjacent limiting portions 42 .

[0093] The setting of the gap K1 can provide a certain buffer space for each limiting portion 42 in the radial direction X. When the cylindrical battery 1000 is impacted or falls, the gap K1 can absorb the radial load to a certain extent, thereby improving the restraint effect on the bent portion 222.

[0094] Furthermore, the setting of the gap K1 can also reduce the risk of structural resonance and friction loss in the limiting portion 42 when the limiting portion 42 is slightly deformed due to external force, thereby reducing the mutual interference and influence between two adjacent limiting portions 42.

[0095] In some embodiments, the size of the gap K1 along the radial direction X is smaller than the size of the limiting portion 42 along the axial direction Z, so as to reasonably design the size of the gap K1. On the basis of improving the buffering capacity of the gap K1, the influence of the setting of the gap K1 on the size of the cylindrical battery 1000 in the radial direction X is reduced.

[0096] In some embodiments, the plurality of limiting portions 42 include a first limiting portion 421 .

[0097] In some embodiments, the first limiting portion 421 includes a first portion 4211 and a second portion 4212 , and the first portion 4211 connects the first insulating portion 41 and the second portion 4212 .

[0098] In some embodiments, in the radial direction X, the first portion 4211 covers the end surface 2221 of the bent portion 222 close to the axis S and is connected to the end surface 2221 .

[0099] The first portion 4211 can limit the position of the bent portion 222 in the radial direction X, reducing the risk of deformation of the bent portion 222. In addition, the first portion 4211 can also provide protection for at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, reducing the risk of corrosion and the like on the end surface 2221 of the bent portion 222 facing the axis S.

[0100] In some embodiments, in the axial direction Z, at least a portion of the second portion 4212 is disposed on a side of the bent portion 222 facing away from the electrode assembly 1 .

[0101] The second portion 4212 can provide insulation and protection for the bent portion 222 on the side of the bent portion 222 facing away from the electrode assembly 1. When multiple cylindrical batteries 1000 are connected via a busbar, the second portion 4212 can be located between the busbar and the bent portion 222 along the axial direction Z to provide insulation and buffering, reducing the risk of a short circuit caused by contact between the busbar and the bent portion 222.

[0102] In some embodiments, the second portion 4212 may cover a side of the bent portion 222 facing away from the electrode assembly 1 .

[0103] The second portion 4212 forms an effective seal with the side of the bent portion 222 facing away from the electrode assembly 1, further extending the sealing path between the first insulating member 4 and the bent portion 222, thereby enhancing the insulating and sealing effect of the first insulating member 4. Furthermore, the second portion 4212 helps improve the corrosion resistance of at least a portion of the surface of the bent portion 222 facing away from the electrode assembly 1, thereby improving the performance of the cylindrical battery 1000.

[0104] In other embodiments, the second portion 4212 may be spaced apart from a surface of the bent portion 222 facing away from the electrode assembly 1 .

[0105] In some embodiments, the plurality of limiting portions 42 further include a second limiting portion 422 disposed adjacent to the first limiting portion 421 . The second limiting portion 422 is located on a side of the first limiting portion 421 close to the axis S.

[0106] The second limiting portion 422 may be connected to the first limiting portion 421 , or the second limiting portion 422 may be spaced apart from the first limiting portion 421 .

[0107] When the cylindrical battery 1000 is impacted or falls, the second limiting portion 422 can provide further support and restraint for the first limiting portion 421 and the bent portion 222 .

[0108] For example, when the cylindrical battery 1000 is impacted or falls, if the bending portion 222 and the first limiting portion 421 are deformed in the radial direction X toward the side close to the axis S under the action of external force, the second limiting portion 422 can support the first limiting portion 421 to reduce the risk of continued deformation of the bending portion 222.

[0109] In some embodiments, the second limiting portion 422 is tilted toward a side close to the first limiting portion 421 .

[0110] The second limiting portion 422 arranged obliquely can effectively decompose the load in the axial direction Z and the radial direction X, and provide good support and restraint for the first limiting portion 421 and the bent portion 222 .

[0111] In some embodiments, one end of the second limiting portion 422 is connected to the first insulating portion 41, and the other end contacts a surface of the first limiting portion 421 that is closer to the axis S. In other words, along the direction from the bottom wall 21 toward the end cap assembly 3, the second limiting portion 422 can be tilted toward a side away from the axis S. Therefore, the second limiting portion 422, the first limiting portion 421, and the first insulating portion 41 form a stable triangular structure, which helps to enhance the restraining effect of the first limiting portion 421 and the second limiting portion 422 on the bent portion 222.

[0112] In other embodiments, the second limiting portion 422 may be inclined toward a side close to the axis S along the direction of the bottom wall 21 pointing toward the end cover assembly 3 .

[0113] In some embodiments, the minimum thickness of the second limiting portion 422 is H4, the minimum thickness of the first insulating portion 41 is H1, and 0.25≤H4 / H1≤1.

[0114] As an example, H4 / H1 may be 0.25, 0.3, 0.35, 0.5, 0.6, 0.75, 0.8, 0.9, 1, or a value between any two of the above values.

[0115] In these embodiments, setting H4 / H1 to be greater than or equal to 0.25 helps to increase the strength of the second limiting portion 422 and improve its support and restraint effect on the first limiting portion 421 and the bent portion 222. Setting H4 / H1 to be less than or equal to 1 helps to increase the thickness of the first insulating portion 41 and improve the sealing effect of the first insulating portion 41.

[0116] In some embodiments, the length of the second limiting portion 422 is H5, the thickness of the bent portion 222 is H3, and H5 ≥ H3 + 2H4. This helps the second limiting portion 422 completely cover the end surface 2221 and cover at least a portion of the surface of the bent portion 222 facing away from the end cap assembly 3, thereby improving the shock resistance of the cylindrical battery 1000 and the corrosion resistance of the bent portion 222. The length of the second limiting portion 422 can refer to the distance from one end of the second limiting portion 422 connected to the first insulating portion 41 to the other end thereof.

[0117] In some embodiments, the cylindrical battery 1000 further includes a second insulating member 5 . In the axial direction Z, the second insulating member 5 is disposed on a side of the bent portion 222 facing away from the electrode assembly 1 .

[0118] When multiple cylindrical batteries 1000 are connected via a busbar, the second insulating member 5 can provide insulation and buffering between the busbar and the bent portion 222 along the axial direction Z, thereby further reducing the risk of short circuit caused by contact between the busbar and the bent portion 222 .

[0119] In some embodiments, the cylindrical battery 1000 further includes an insulating film 6 , which is sleeved on the shell 2 to insulate and seal the shell 2 , thereby reducing the risk of short circuit in the shell 2 .

[0120] In some embodiments, a portion of the insulating film 6 is located on the side of the bent portion 222 facing away from the electrode assembly 1 in the axial direction Z. When multiple cylindrical batteries 1000 are connected via a busbar, a portion of the insulating film 6 can be provided along the axial direction Z to insulate between the busbar and the bent portion 222, further reducing the risk of a short circuit caused by contact between the busbar and the bent portion 222.

[0121] In some embodiments, the first insulating member 4 further includes an insulating protrusion 43, which protrudes from a side of the first insulating portion 41 facing the end cap assembly 3. The insulating protrusion 43 may correspond to one of the plurality of limiting portions 42 in the axial direction Z.

[0122] In some embodiments, the end cap assembly 3 includes an end cap 31 and a bursting disk 32 .

[0123] The explosion-proof disc 32 can be provided on the end cap 31. When the air pressure inside the cylindrical battery 1000 exceeds the upper limit that the explosion-proof disc 32 can withstand, the air pressure inside the cylindrical battery 1000 can cause the explosion-proof disc 32 to flip away from the electrode assembly 1 and explode, thereby achieving the purpose of power outage and pressure relief. This helps to reduce the risk of explosion of the cylindrical battery 1000 due to excessive internal air pressure and improve the safety performance of the cylindrical battery 1000.

[0124] In some embodiments, the end cap 31 includes an end cap body 311 and an end cap protrusion 312 . In the axial direction Z, the end cap protrusion 312 protrudes relative to the end cap body 311 in a direction away from the electrode assembly 1 .

[0125] The end cap protrusion 312 may be of any suitable shape protruding from the side of the end cap body 311 facing away from the electrode assembly 1 . For example, the end cap protrusion 312 may be annular, arc-shaped, block-shaped, columnar, or the like.

[0126] In some embodiments, the explosion-proof disc 32 includes an explosion-proof disc body 321 and a connecting portion 322 . The explosion-proof disc body 321 is provided on the side of the end cover 31 facing the electrode assembly 1 , and the connecting portion 322 is provided on the side of the end cover body 311 facing away from the electrode assembly 1 .

[0127] The provision of the connection portion 322 can increase the connection area between the explosion-proof disc 32 and the end cover body 311 , thereby improving the reliability of the connection between the explosion-proof disc 32 and the end cover body 311 .

[0128] In some embodiments, in the radial direction X, at least a portion of the insulating protrusion 43 is located between the connecting portion 322 and the end cover protrusion 312 .

[0129] In the radial direction X, a portion of the insulating protrusion 43 may be located between the connecting portion 322 and the end cover protrusion 312 , or the entire insulating protrusion 43 may be located between the connecting portion 322 and the end cover protrusion 312 .

[0130] In the embodiment of the present application, the insulating protrusion 43 can act as a buffer between the connecting portion 322 and the end cap protrusion 312, reducing the risk of mutual interference between the connecting portion 322 and the end cap protrusion 312 under the action of external forces. At the same time, in the radial direction X, the insulating protrusion 43 can cover the end face of the connecting portion 322 facing the end cap protrusion 312, thereby improving the corrosion resistance of the end face of the connecting portion 322 facing the end cap protrusion 312. In addition, the connecting portion 322 and the end cap protrusion 312 can also clamp the insulating protrusion 43 in the radial direction X to limit the insulating protrusion 43, thereby limiting the position of the first insulating portion 41 and the limiting portion 42 through the insulating protrusion 43, thereby reducing the risk of the first insulating portion 41 and the limiting portion 42 being displaced relative to the bending portion 222, thereby helping to improve the stability of the first insulating member 4 and the sealing effect of the first insulating member 4.

[0131] In some embodiments, the minimum thickness of the first insulating portion 41 is H1 ; in the axial direction Z, the height of the insulating protrusion 43 is H2 ; 0<H2≤0.5H1.

[0132] The height of the insulating protrusion 43 refers to the height of the insulating protrusion 43 in the axial direction Z. As an example, H2 may be 0.05H1, 0.1H1, 0.2H1, 0.35H1, 0.4H1, 0.45H1, 0.5H1, or a value between any two of the above values.

[0133] In the embodiment of the present application, H2 is set to be greater than 0 and less than or equal to 0.5H1, so as to reasonably set the relationship between the minimum thickness of the first insulating part 41 and the height of the insulating protrusion 43. On the basis of improving the insulation effect and sealing effect of the first insulating part 41, the structural strength of the insulating protrusion 43 is improved, thereby improving the stability of the first insulating part 4.

[0134] In some embodiments, the limiting portion 42 includes a recessed portion 423 recessed from the surface of the first insulating portion 41 facing away from the end cap assembly 3. The end of the bent portion 222 facing the axis S can be disposed within the recessed portion 423, and a portion of the inner wall of the recessed portion 423 can cover at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, thereby limiting the position of the bent portion 222 via the inner wall of the recessed portion 423.

[0135] In some embodiments, among the multiple limiting portions 42, the depth of the recess 423 of the limiting portion 42 closest to the axis S along the axial direction Z is greater than the depth of the recesses 423 of the other limiting portions 42 along the axial direction Z. Because the recess 423 of the limiting portion 42 closest to the axis S has the greatest depth, it has the best limiting effect and strength. When the recesses 423 of other limiting portions 42 fail under the action of external forces, the limiting portion 42 closest to the axis S can provide a backup constraint for the bent portion 222, thereby reducing the risk of continued deformation of the bent portion 222.

[0136] In some embodiments, among the plurality of limiting portions 42 , the recess 423 of the limiting portion 42 closest to the axis S has a depth H6 in the axial direction Z, where H6≤0.5H1, to reduce the risk of the first insulating member 4 breaking at the recess 423 .

[0137] In some embodiments, the minimum thickness of the first insulating portion 41 is H1, the thickness of the bent portion 222 is H3, and 0.1 mm ≤ H1 - H3 ≤ 0.5 mm.

[0138] As an example, H1-H3 may be 0.1 mm, 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, or a value between any two of the above values.

[0139] In the embodiment of the present application, the difference between the minimum thickness of the first insulating portion 41 and the thickness of the bent portion 222 is set to be greater than or equal to 0.1 mm, which helps increase the thickness of the first insulating portion 41, improve the strength of the first insulating portion 41, and thus enhance the insulation and sealing capabilities of the first insulating portion 41. Furthermore, the difference between the minimum thickness of the first insulating portion 41 and the thickness of the bent portion 222 is set to be less than or equal to 0.5 mm, which helps reduce the impact of the first insulating portion 41 on the size of the cylindrical battery 1000.

[0140] In some embodiments, 0.3 mm ≤ H1 ≤ 1 mm.

[0141] As an example, H1 may be 0.3 mm, 0.5 mm, 0.6 mm, 0.8 mm, 0.9 mm, 1 mm, or a value between any two of the above values.

[0142] In the embodiment of the present application, setting the minimum thickness H1 of the first insulating portion 41 to be greater than or equal to 0.3 mm helps to improve the strength of the first insulating portion 41, thereby enhancing the insulation and sealing capabilities of the first insulating portion 41. Furthermore, setting the minimum thickness H1 of the first insulating portion 41 to be less than or equal to 1 mm helps to reduce the impact of the first insulating portion 41 on the size of the cylindrical battery 1000.

[0143] In some embodiments, the thickness of the bent portion 222 is H3, 0.2 mm ≤ H3 ≤ 0.5 mm.

[0144] The thickness of the bent portion 222 may refer to the minimum thickness of the bent portion 222 in its thickness direction. As an example, the thickness H3 of the bent portion 222 may be 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, or a value between any two of the above values.

[0145] In the embodiment of the present application, the thickness H3 of the bent portion 222 is set to be greater than or equal to 0.2 mm, which helps to improve the strength of the bent portion 222 and reduce the risk of deformation of the bent portion 222 under external forces. This further reduces the risk of relative displacement between the bent portion 222 and the first insulating portion 41, which may cause leakage gaps, and helps improve the sealing effect of the first insulating member 4. Furthermore, the thickness H3 of the bent portion 222 is set to be less than or equal to 0.5 mm, which helps to reduce the impact of the bent portion 222 on the radial dimension X of the cylindrical battery 1000.

[0146] In some embodiments, the limiting portions 42 are disposed around the circumference of the cylindrical battery 1000. Each limiting portion 42 is annular, and one of the limiting portions 42 can circumferentially cover at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, thereby limiting and protecting the bent portion 222 in the circumferential direction, and providing sealing and corrosion resistance in the circumferential direction.

[0147] In other embodiments, the limiting portion 42 includes multiple sub-portions, which are spaced apart along the circumference of the cylindrical battery 1000. The multiple sub-portions of the limiting portion 42 can cover multiple areas of the end surface 2221 of the bent portion 222 facing the axis S in the circumferential direction to improve the limiting effect and protection of the bent portion 222.

[0148] Reference Figure 9, an embodiment of the present application further provides a battery module, the battery module including a plurality of cylindrical batteries 1000 provided according to any embodiment of the present application.

[0149] In some embodiments, the battery module 3000 further includes a plurality of bus bars (not shown) that connect the plurality of cylindrical batteries 1000 .

[0150] 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 .

[0151] Reference Figure 10 , an embodiment of the present application further provides an electrical device, 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.

[0152] 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.

[0153] 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 comprising a bottom wall and a side wall, wherein the side wall comprises a side wall body and a bent portion, the side wall body being connected to the bottom wall, and the bent portion extending from an end of the side wall body away from the bottom wall and bending toward the axis of the cylindrical battery; an electrode assembly, housed in the housing; an end cap assembly, wherein the end cap assembly and the bottom wall are arranged along the axial direction of the cylindrical battery, the end cap assembly is insulated from and connected to the side wall, and in the axial direction, the bent portion is located on a side of the end cap assembly facing away from the bottom wall, and the housing and the end cap assembly have different polarities; The first insulating member includes a first insulating portion and a plurality of limiting portions provided on the first insulating portion, wherein the first insulating portion is provided on a side of the end cover assembly facing the bent portion, a portion of the first insulating portion is provided between the bent portion and the end cover assembly, and the plurality of limiting portions are arranged along the radial direction of the cylindrical battery. In the radial direction, one of the limiting portions covers at least a portion of the end surface of the bent portion facing the axis and is connected to the end surface.

2. The cylindrical battery according to claim 1, characterized in that: Along the direction of the bottom wall pointing to the end cover assembly, the limiting portion protrudes from the surface of the first insulating portion facing away from the end cover assembly.

3. The cylindrical battery according to claim 2, characterized in that: Among the plurality of limiting portions, a height of the limiting portion closest to the axis along the axial direction is greater than heights of the other limiting portions along the axial direction.

4. The cylindrical battery according to claim 2 or 3, characterized in that: At least one of the plurality of limiting portions protrudes from a surface of the bent portion facing away from the end cover assembly along a direction from the bottom wall toward the end cover assembly.

5. The cylindrical battery according to any one of claims 2 to 4, characterized in that: In the radial direction, gaps are provided between adjacent limiting portions.

6. The cylindrical battery according to claim 5, characterized in that: A dimension of the gap along the radial direction is smaller than a dimension of the limiting portion along the axial direction.

7. The cylindrical battery according to any one of claims 2 to 6, characterized in that: The plurality of limiting portions include a first limiting portion; The first limiting portion includes a first portion and a second portion, the first portion connecting the first insulating portion and the second portion; In the radial direction, the first portion covers the end surface of the bent portion close to the axis and is connected to the end surface; In the axial direction, at least a portion of the second portion is disposed on a side of the bent portion facing away from the electrode assembly.

8. The cylindrical battery according to claim 7, characterized in that: The plurality of limiting portions further include a second limiting portion disposed adjacent to the first limiting portion, the second limiting portion being located on a side of the first limiting portion close to the axis; The second limiting portion is inclined toward a side close to the first limiting portion.

9. The cylindrical battery according to claim 8, characterized in that: One end of the second limiting portion is connected to the first insulating portion, and the other end is in contact with a surface of the first limiting portion close to the axis.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: The first insulating member further includes an insulating protrusion, which protrudes from a side of the first insulating portion facing the end cap assembly; The end cap assembly includes an end cap and a burst-proof disk, the end cap includes an end cap body and an end cap protrusion, and in the axial direction, the end cap protrusion protrudes relative to the end cap body in a direction away from the electrode assembly; The explosion-proof disk includes an explosion-proof disk body and a connecting portion. The explosion-proof disk body is arranged on the side of the end cover facing the electrode assembly, and the connecting portion is arranged on the side of the end cover body away from the electrode assembly. In the radial direction, at least part of the insulating protrusion is located between the connecting portion and the end cover protrusion.

11. The cylindrical battery according to claim 10, characterized in that: The minimum thickness of the first insulating portion is H1; in the axial direction, the height of the insulating protrusion is H2; 0<H2≤0.5H1.

12. The cylindrical battery according to claim 1, characterized in that: The limiting portion includes a recessed portion recessed from a surface of the first insulating portion facing away from the end cap assembly.

13. The cylindrical battery according to claim 12, characterized in that: Among the plurality of limiting portions, a depth of the recessed portion of the limiting portion closest to the axis along the axial direction is greater than a depth of the recessed portions of the other limiting portions along the axial direction.

14. The cylindrical battery according to any one of claims 1 to 13, characterized in that: The minimum thickness of the first insulating portion is H1, the thickness of the bent portion is H3, and 0.1 mm ≤ H1 - H3 ≤ 0.5 mm; and / or, 0.2mm≤H3≤0.5mm.

15. The cylindrical battery according to any one of claims 1 to 14, characterized in that: The limiting portion is arranged around the circumference of the cylindrical battery; or, The limiting portion includes a plurality of sub-portions, and the plurality of sub-portions are arranged at intervals along the circumference of the cylindrical battery.

16. A battery module, characterized in that: The invention comprises a plurality of cylindrical batteries according to any one of claims 1 to 15.

17. An electrical device, characterized in that: Comprising the cylindrical battery according to any one of claims 1-15.

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