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, and the side wall comprises a side wall main body connected to the bottom wall and a bending part which extends from one end, far away from the bottom wall, of the side wall main body and is bent towards the axis of the cylindrical battery; 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; in the first insulating part, at least part of a first insulating part is clamped between the bending part and the end cover assembly, at least part of a second insulating part is clamped between the side wall body and the end cover assembly, a gap is formed between the second insulating part and the first insulating part, and the gap is located between the end cover assembly and the bending part in the axial direction.

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 sealing performance of cylindrical batteries has always been a research direction in the industry. Summary of the Invention

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

[0005] In the first aspect, the present application provides a cylindrical battery, which includes a shell, an electrode assembly, an end 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 second insulating portion, at least a portion of the first insulating portion is clamped between the bending portion and the end cap assembly, at least a portion of the second insulating portion is clamped between the side wall body and the end cap assembly, a gap is provided between the second insulating portion and the first insulating portion, and in the axial direction, the gap is located between the end cap assembly and the bending portion.

[0006] When the cylindrical battery is impacted or dropped, the gap can be used to provide deformation space between the first and second insulating parts, buffering pressure and reducing the risk of a gap between the first and second insulating parts and the end cap assembly or sidewall due to deformation, thereby reducing the possibility of electrolyte leakage in the cylindrical battery and helping to improve the sealing performance of the cylindrical battery. In addition, because the gap is axially located between the end cap assembly and the bent portion, when the cylindrical battery is impacted or dropped, causing the bent portion to be pressed axially toward the side closest to the bottom wall, the gap can reduce the risk of the first insulating part moving radially under the action of the bent portion and contacting the second insulating part, thereby affecting the sealing effect of the second insulating part.

[0007] In one or more of the above optional embodiments, at least a portion of the first insulating part is bonded to the end cap assembly, which can reduce the difficulty of connecting the first insulating part and the end cap assembly while improving the reliability of the connection between the first insulating part and the end cap assembly, thereby helping to improve the production efficiency of cylindrical batteries.

[0008] In one or more optional embodiments above, the first insulating portion includes a first part and a second part. In the axial direction of the cylindrical battery, at least a portion of the first part is located between the bent portion and the end cover assembly and is fixedly connected to the end cover assembly, and the second part protrudes from the surface of the first part facing the bent portion; in the radial direction of the cylindrical battery, at least a portion of the second part is located on the side of the bent portion facing the axis.

[0009] At least a portion of the second portion of the first insulating portion is radially disposed on the side of the bent portion facing the axis. When the cylindrical battery is impacted or dropped, at least a portion of the second portion can provide a certain radial cushion for the bent portion, thereby reducing the degree of radial deformation of the bent portion. Furthermore, when the bent portion deforms radially and contacts the second portion, an effective seal is formed between the bent portion and the second portion, thereby improving the safety performance of the cylindrical battery.

[0010] In one or more of the above optional embodiments, in the radial direction, the second part covers at least a portion of the end face of the bending portion facing the axis. On the one hand, it helps to increase the contact area between the first insulating portion and the side wall, so that an effective seal can be formed between the second part and at least a portion of the end face of the bending portion facing the axis, extending the sealing path between the first insulating portion and the side wall, and improving the insulating sealing effect of the first insulating portion. On the other hand, it also helps to improve the corrosion resistance of at least a portion of the end face of the bending portion facing the axis, thereby improving the performance of the cylindrical battery.

[0011] In one or more of the above optional embodiments, the end cap assembly includes an end cap, which includes an end cap body and a protrusion. In the axial direction, the protrusion is arranged on the side of the end cap body facing away from the electrode assembly and protrudes relative to the end cap body. In the radial direction, at least a portion of the second portion is arranged between the protrusion and the bent portion. When the cylindrical battery is impacted or dropped, at least a portion of the second portion can act as a stress buffer and insulating seal between the bent portion and the protrusion, thereby reducing the risk of direct contact between the bent portion and the protrusion, which may cause damage, short circuit, etc.

[0012] In one or more optional embodiments above, the first insulating portion further includes a third portion, which surrounds the second portion and is connected to the second portion. In the axial direction, at least a portion of the third portion is located on the side of the bend away from the electrode assembly.

[0013] The provision of the third portion can further increase the contact area between the first insulating portion and the bent portion. The third portion can be used to form an effective seal with the side of the bent portion facing away from the electrode assembly, extending the sealing path between the first insulating portion and the bent portion, thereby improving the insulating sealing effect of the first insulating portion. In addition, the third portion is insulated and sealed with at least part of the surface of the bent portion facing away from the electrode assembly, which helps to reduce the possibility of external impurities contacting the end face of the bent portion facing the axis, helps to improve the corrosion resistance of the end face, and improves the performance of the cylindrical battery. In addition, when multiple cylindrical batteries are connected by a bus bar, the bus bar is connected to the protrusion of the end cover, and the third portion can be located axially between the bus bar and the bent portion to play an insulating and buffering role, reducing the risk of short circuit caused by contact between the bus bar and the bent portion.

[0014] In one or more of the above optional embodiments, in the same plane perpendicular to the axial direction, the orthographic projection of the end face of the bending portion facing the axis is located within the orthographic projection of the third part, and the orthographic projection of the end face of the third part away from the axis is located within the orthographic projection of the bending portion. On the one hand, the third part can effectively cover the bending portion, thereby improving the insulation, sealing and protection effects of the third part on the bending portion. On the other hand, it can also reduce the influence of the setting of the third part on the radial size of the cylindrical battery.

[0015] In one or more of the above optional embodiments, the cylindrical battery further comprises a second insulating member, axially disposed on a side of the third portion away from the bend. When multiple cylindrical batteries are connected via a busbar, the second insulating member provides insulation and buffering between the busbar and the third portion along the axial direction, further reducing the risk of a short circuit caused by contact between the busbar and the bend.

[0016] In one or more of the above optional embodiments, the sidewall body includes a first sub-section, a second sub-section, and a third sub-section. The first sub-section surrounds the electrode assembly, the third sub-section surrounds the end cap assembly, and the second sub-section connects the first and third sub-sections. The second sub-section protrudes from the surface of the first sub-section facing the electrode assembly, and the second sub-section protrudes from the surface of the third sub-section facing the end cap assembly. In the axial direction, a portion of the second sub-section may be located between the end cap assembly and the electrode assembly to provide a certain degree of axial positioning of the end cap assembly and the electrode assembly. In the axial direction, a portion of the end cap assembly is located between the bent portion and the second sub-section. The second sub-section and the bent portion may axially clamp the end cap assembly and limit the end cap assembly. In the axial direction, a portion of the second insulating portion is located between the second sub-section and the end cap assembly to insulate the second sub-section from the end cap assembly, reducing the risk of contact between the second sub-section and the end cap assembly, thereby causing a short circuit. In the radial direction of the cylindrical battery, another portion of the second insulating portion is located between the end cap assembly and the third sub-section to insulate the end cap assembly and the third sub-section, thereby reducing the risk of contact between the end cap assembly and the third sub-section, thereby causing a short circuit.

[0017] In one or more of the above optional embodiments, in the axial direction, the minimum thickness of the portion of the first insulating portion sandwiched between the end cap assembly and the bent portion is H1, and the thickness of the side wall body is H3, 0.5≤H1 / H3≤2, 0.3mm≤H1≤1mm. This helps to 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. On the other hand, it also helps to reduce the impact of the provision of the first insulating portion on the size of the cylindrical battery. And / or, in the radial direction of the cylindrical battery, the minimum thickness of the portion of the second insulating portion sandwiched between the end cap assembly and the side wall body is H4, 1≤H4 / H1≤1.5, 0.3mm≤H4≤1.5mm. On the one hand, it helps to increase the thickness of the portion of the second insulating portion sandwiched between the end cap assembly and the side wall body, improve the strength of the second insulating portion, and thus improve the insulation and sealing capabilities of the second insulating portion. On the other hand, it helps to reduce the impact of the provision of the second insulating portion on the size of the cylindrical battery.

[0018] In one or more of the above optional embodiments, in the radial direction of the cylindrical battery, the width of the gap is G, the thickness of the side wall body is H3, 0.25≤G / H3≤2; 0.2mm≤G≤1mm, on the one hand, it also helps to increase the width of the gap, improve the ability of the gap to buffer the pressure between the first insulating part and the second insulating part, and reduce the risk of the first insulating part and the second insulating part being deformed under the action of external pressure and thus generating a gap. On the other hand, it also helps to improve the insulation capacity of the first insulating part and the second insulating part, and reduce the risk of the side wall and the end cover assembly contacting at the gap and causing a short circuit.

[0019] In one or more optional embodiments above, in the axial direction, the gap includes a first end close to the end cover assembly and a second end close to the bend portion, and the width of the second end in the radial direction of the cylindrical battery is smaller than the width of the first end in the radial direction.

[0020] In one or more of the above optional embodiments, at least a portion of the sidewall surface of the gap between the first and second ends is an inclined surface, thereby better buffering stress. Furthermore, when the cylindrical battery is impacted or dropped, causing the bent portion to be axially pressed downward toward the side closest to the bottom wall, the greater width of the first end of the gap can reduce the risk of stress concentration at the first end of the gap, thereby helping to reduce the impact of this stress on the end cap assembly.

[0021] 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.

[0022] 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

[0023] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0024] Figure 1 A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0025] Figure 2 for Figure 1 A schematic cross-sectional view of a cylindrical battery is shown;

[0026] Figure 3 for Figure 1 A schematic cross-sectional view of a cylindrical battery shown;

[0027] Figure 4 for Figure 1 Another schematic cross-sectional view of a partial cylindrical battery shown;

[0028] Figure 5 for Figure 4 An enlarged schematic diagram at the circle;

[0029] Figure 6 A schematic diagram of a battery module provided in some embodiments of the present application;

[0030] Figure 7 Schematic diagram of electrical equipment provided in some embodiments of the present application.

[0031] The reference numerals for the specific embodiments are as follows:

[0032] Cylindrical battery 1000; box 2000; battery module 3000; electrical equipment 4000;

[0033] Electrode assembly 1; housing 2; bottom wall 21; side wall 22; side wall body 221; first sub-portion 2211; second sub-portion 2212; third sub-portion 2213; bent portion 222; end surface 2221;

[0034] End cover assembly 3; end cover 31; end cover body 311; protrusion 312;

[0035] First insulating member 4; first insulating portion 41; first part 411; second part 412; third part 413; second insulating portion 42; second insulating member 5; insulating film 6; gap K1; axis S; first end K11; second end K12; radial direction X; axial direction Z. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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.

[0041] The cylindrical battery, battery module and electrical equipment of the present application are described below with reference to the accompanying drawings.

[0042] Reference Figures 1 to 5 , an embodiment of the present application provides a cylindrical battery 1000.

[0043] 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.

[0044] The cylindrical battery 1000 may be a 21700 battery, an 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries.

[0045] 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.

[0046] In some embodiments, the cylindrical battery 1000 includes a housing 2 and an electrode assembly 1 housed in the housing 2 .

[0047] 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.

[0048] 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.

[0049] In some embodiments, the first pole piece, the diaphragm, and the second pole piece are wound together.

[0050] 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.

[0051] In some embodiments, the first empty foil region is wound into multiple turns.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] In some embodiments, the second empty foil region is wound into multiple turns.

[0056] 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.

[0057] 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.

[0058] 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 .

[0059] In some embodiments, one end of the housing 2 along the axial direction Z is provided with a housing opening.

[0060] 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. One end of the side wall 22 away from the bottom wall 21 along the axial direction Z forms a housing opening.

[0061] 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.

[0062] 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.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] In some embodiments, the end cap assembly 3 is insulated from and connected to the side wall 22 .

[0067] 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.

[0068] 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 .

[0069] In some embodiments, the cylindrical battery 1000 also includes a first insulating member 4, which includes a first insulating portion 41. At least a portion of the first insulating portion 41 is clamped between the bending portion 222 and the end cover assembly 3. On the one hand, the setting of the first insulating portion 41 can be used to insulate the bending portion 222 and the end cover assembly 3, reducing the risk of short circuit between the end cover assembly 3 and the side wall 22. On the other hand, the first insulating portion 41 can also play a sealing role between the bending portion 222 and the end cover assembly 3, reducing the risk of leakage and corrosion of the cylindrical battery 1000.

[0070] In some embodiments, at least a portion of the first insulating portion 41 is fixed to the end cap assembly 3. When the cylindrical battery 1000 is impacted or dropped, the first insulating portion 41 can move synchronously with the end cap assembly 3 to reduce the risk of relative displacement between the first insulating portion 41 and the end cap assembly 3 and thereby improve the insulation and sealing effects of the first insulating portion 41.

[0071] There are various ways to secure the first insulating portion 41 to the end cap assembly 3. In one example, the first insulating portion 41 can be bonded to the end cap assembly 3. In another example, a retaining protrusion can be provided on one side of the first insulating portion 41 facing the end cap assembly 3, or on the other side of the end cap assembly 3 facing the first insulating portion 41, so that the bent portion 222 can press the first insulating portion 41 against the end cap assembly 3.

[0072] In some embodiments, the first insulating member 4 further includes a second insulating portion 42, at least a portion of which is clamped between the sidewall body 221 and the end cap assembly 3. The second insulating portion 42 can be used to insulate the sidewall body 221 and the end cap assembly 3, and can also provide a seal between the sidewall body 221 and the end cap assembly 3, thereby reducing the risk of leakage and corrosion in the cylindrical battery 1000 and improving the safety performance of the cylindrical battery 1000.

[0073] In some embodiments, a gap K1 is provided between the first insulating portion 41 and the second insulating portion 42 .

[0074] When the cylindrical battery 1000 is impacted or falls, the gap K1 can be used to provide deformation space between the first insulating part 41 and the second insulating part 42 to buffer pressure and reduce the risk of a gap being generated between the first insulating part 41 and the second insulating part 42 and the end cover assembly 3 or the side wall 22 due to deformation, thereby helping to improve the sealing effect of the cylindrical battery 1000 and enhance the safety performance of the cylindrical battery 1000.

[0075] Moreover, in the embodiment of the present application, the setting of the gap K1 enables either the first insulating part 41 or the second insulating part 42 to independently seal the cylindrical battery 1000 , which helps to reduce the mutual interference between the first insulating part 41 and the second insulating part 42 .

[0076] In some embodiments, in the axial direction Z, the gap K1 is located between the end cover assembly 3 and the bent portion 222 .

[0077] The gap K1 of the embodiment of the present application is located on the side of the end cover assembly 3 facing away from the bottom wall 21 in the axial direction Z. The ends of the first insulating portion 41 and the second insulating portion 42 close to the gap K1 can be arranged at intervals in the radial direction X of the cylindrical battery 1000. This can reduce the risk that when the cylindrical battery 1000 is impacted or falls, causing the bent portion 222 to be pressed downward along the axial direction Z toward the side close to the bottom wall 21, the first insulating portion 41 moves along the radial direction X under the action of the bent portion 222 and contacts the second insulating portion 42, thereby affecting the sealing effect of the second insulating portion 42.

[0078] The gap K1 is located between the end cover assembly 3 and the bent portion 222 along the axial direction Z. It can also buffer the pressure between the bent portion 222 and the end cover assembly 3 along the axial direction Z, reducing the extrusion of the end cover assembly 3 when the bent portion 222 is pressed downward.

[0079] In some embodiments, the gap K1 may be arranged around the circumference of the end cover assembly 3 .

[0080] In some embodiments, a plurality of gaps K1 may be spaced apart along the circumference of the end cap assembly 3 and arranged in a centrally symmetrical manner around the axis S of the cylindrical battery 1000 .

[0081] In some embodiments, at least a portion of the first insulating part 41 is bonded to the end cap assembly 3, which can reduce the difficulty of connecting the first insulating part 41 and the end cap assembly 3 while improving the reliability of the connection between the first insulating part 41 and the end cap assembly 3, thereby helping to improve the production efficiency of the cylindrical battery 1000.

[0082] In other embodiments, at least a portion of the first insulating portion 41 may be fixed to the end cover assembly 3 by riveting, clamping or other means.

[0083] In some embodiments, the first insulating portion 41 includes a first portion 411 and a second portion 412. In the axial direction Z of the cylindrical battery 1000, at least a portion of the first portion 411 is located between the bent portion 222 and the end cover assembly 3 and is fixedly connected to the end cover assembly 3. The second portion 412 protrudes from the surface of the first portion 411 toward the bent portion 222.

[0084] In the axial direction Z, at least a portion of the first portion 411 is disposed on the side of the end cap assembly 3 facing away from the bottom wall 21. It is spaced apart from the second insulating portion 42, forming the aforementioned gap K1. Furthermore, at least a portion of the first portion 411 is fixedly connected to the end cap assembly 3, for example, by being bonded to the end cap assembly 3. The second portion 412 protrudes from the surface of the first portion 411 facing the bent portion 222.

[0085] In some embodiments, in the radial direction X of the cylindrical battery 1000 , at least a portion of the second portion 412 is located on a side of the bent portion 222 facing the axis S.

[0086] There are various positional relationships between the second part 412 and the bending portion 222. For example, at least a portion of the second part 412 can be spaced apart from the side of the bending portion 222 toward the axis S in the radial direction X, or at least a portion of the second part 412 can also cover at least a portion of the end surface 2221 of the bending portion 222 toward the axis S.

[0087] In the embodiment of the present application, at least a portion of the second portion 412 of the first insulating portion 41 is disposed along the radial direction X on the side of the bent portion 222 facing the axis S. When the cylindrical battery 1000 is impacted or dropped, at least a portion of the second portion 412 can provide a certain cushioning effect for the bent portion 222 in the radial direction X, thereby reducing the degree of deformation of the bent portion 222 in the radial direction X. Furthermore, when the bent portion 222 deforms in the radial direction X and contacts the second portion 412, an effective seal can be formed between the bent portion 222 and the second portion 412, thereby helping to improve the safety performance of the cylindrical battery 1000.

[0088] In some embodiments, in the radial direction X, the second portion 412 covers at least a portion of the end surface 2221 of the bent portion 222 facing the axis S. The second portion 412 may completely cover the end surface 2221 of the bent portion 222 facing the axis S in the radial direction X, or the second portion 412 may cover a portion of the end surface 2221 of the bent portion 222 facing the axis S in the radial direction X. When the second portion 412 covers at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, the second portion 412 may contact and be connected to the end surface 2221.

[0089] The second portion 412 of the embodiment of the present application covers at least a portion of the end surface 2221 of the bent portion 222 facing the axis S in the radial direction X. On the one hand, it helps to increase the contact area between the first insulating portion 41 and the side wall 22, so that an effective seal can be formed between the second portion 412 and at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, extending the sealing path between the first insulating portion 41 and the side wall 22, and improving the insulating sealing effect of the first insulating portion 41. On the other hand, it also helps to improve the corrosion resistance of at least a portion of the end surface 2221 of the bent portion 222 facing the axis S, thereby improving the performance of the cylindrical battery 1000.

[0090] In some embodiments, the second portion 412 is bonded to the end surface 2221 of the bent portion 222 facing the axis S.

[0091] In some embodiments, the minimum thickness of the first portion 411 is H1, the minimum width of the second portion 412 is H2, and 0.5≤H2 / H1≤1.

[0092] The minimum thickness of the first portion 411 is the minimum dimension of the first portion 411 in the axial direction Z, and the minimum width of the second portion 412 is the minimum dimension of the second portion 412 in the radial direction X.

[0093] As an example, H2 / H1 may be 0.5, 0.6, 0.65, 0.7, 0.8, 0.95, 1, or a value between any two of the above values.

[0094] In the embodiment of the present application, setting H2 / H1 to be greater than or equal to 0.5 helps increase the width of the second portion 412, reducing the risk of the second portion 412 breaking when the cylindrical battery 1000 is impacted or dropped, thereby causing leakage of the cylindrical battery 1000. Furthermore, setting H2 / H1 to be less than or equal to 1 helps limit the thickness of the first portion 411, reducing the impact of the first insulating portion 41 on the size of the cylindrical battery 1000 in the axial direction Z.

[0095] In some embodiments, the sidewall body 221 has a thickness H3, where 0.2 mm ≤ H3 ≤ 0.8 mm.

[0096] As an example, the thickness H3 of the sidewall body 221 may be 0.2 mm, 0.25 mm, 0.3 mm, 0.4 mm, 0.45 mm, 0.5 mm, 0.55 mm, 0.6 mm, 0.65 mm, 0.7 mm, 0.75 mm, 0.8 mm, or a value between any two of the above values.

[0097] In the embodiment of the present application, setting the thickness H3 of the side wall body 221 to be greater than or equal to 0.2 mm helps to improve the strength of the side wall body 221 and enhance its protective effect on the electrode assembly 1. In addition, setting the thickness H3 of the side wall body 221 to be less than or equal to 0.8 mm helps to reduce the impact of the setting of the side wall body 221 on the size of the cylindrical battery 1000 in the radial direction X.

[0098] In some embodiments, the end cap assembly 3 includes an end cap 31 .

[0099] In some embodiments, the material of the housing 2 and the end cover 31 can be steel, aluminum, alloy or other materials. The materials of the housing 2 and the end cover 31 can be the same or different.

[0100] In some embodiments, the end cap 31 includes an end cap body 311 and a protrusion 312 . In the axial direction Z, the protrusion 312 is disposed on a side of the end cap body 311 facing away from the electrode assembly 1 and protrudes relative to the end cap body 311 .

[0101] The protrusion 312 may be of any suitable shape protruding from the side of the end cover body 311 away from the electrode assembly 1 . For example, the protrusion 312 may be annular, arc-shaped, block-shaped, columnar, or the like.

[0102] In some embodiments, at least a portion of the second portion 412 is disposed between the bent portion 222 and the protruding portion 312 in the radial direction X. When the cylindrical battery 1000 is impacted or dropped, at least a portion of the second portion 412 can act as a stress buffer and insulation seal between the bent portion 222 and the protruding portion 312, thereby reducing the risk of damage or short circuit caused by direct contact between the bent portion 222 and the protruding portion 312.

[0103] In some embodiments, the first insulating portion 41 further includes a third portion 413 , which surrounds the second portion 412 and is connected to the second portion 412 . In the axial direction Z, at least a portion of the third portion 413 is located on the side of the bending portion 222 away from the electrode assembly 1 .

[0104] The provision of the third portion 413 further increases the contact area between the first insulating portion 41 and the bent portion 222. The third portion 413 can be used to form an effective seal with the side of the bent portion 222 facing away from the electrode assembly 1, extending the sealing path between the first insulating portion 41 and the bent portion 222, thereby enhancing the insulating and sealing effect of the first insulating portion 41. Furthermore, the insulating and sealing effect of the third portion 413 with at least a portion of the surface of the bent portion 222 facing away from the electrode assembly 1 helps reduce the possibility of foreign matter coming into contact with the end surface 2221 of the bent portion 222 facing the axis S, thereby improving the corrosion resistance of the end surface 2221 and enhancing the performance of the cylindrical battery 1000.

[0105] In addition, when multiple cylindrical batteries 1000 are connected through a bus, the bus is connected to the protrusion 312 of the end cover 31, and the third part 413 can be located between the bus and the bent portion 222 along the axial direction Z to play an insulating and buffering role, thereby reducing the risk of short circuit caused by contact between the bus and the bent portion 222.

[0106] In some embodiments, within the same plane perpendicular to the axial direction Z, the orthographic projection of the end surface 2221 of the bent portion 222 facing the axis S is located within the orthographic projection of the third portion 413, and the orthographic projection of the end surface 2221 of the third portion 413 away from the axis S is located within the orthographic projection of the bent portion 222. This allows the third portion 413 to effectively cover the bent portion 222, enhancing the insulation, sealing, and protection provided by the third portion 413 to the bent portion 222. Furthermore, it reduces the impact of the third portion 413 on the dimensions of the cylindrical battery 1000 in the radial direction X.

[0107] In some embodiments, in the radial direction X, a distance L3 between an end of the bent portion 222 close to the axis S and a side of the sidewall body 221 away from the axis S is 1 mm-5 mm.

[0108] As an example, L3 may be 1 mm, 1.5 mm, 2 mm, 3 mm, 3.5 mm, 4 mm, 4.5 mm, 5 mm, or a value between any two of the above values.

[0109] In these embodiments, the spacing L3 between the end of the bent portion 222 near the axis S and the side of the side wall body 221 away from the axis S in the radial direction X is set to be greater than or equal to 1 mm, which helps to increase the size of the bent portion 222 in the radial direction X and improve the limiting effect of the bent portion 222 on the end cap assembly 3 and the first insulating portion 41. In addition, the spacing L3 between the end of the bent portion 222 near the axis S and the side of the side wall body 221 away from the axis S in the radial direction X is set to be less than or equal to 5 mm, which can also reduce the risk of interference between the bent portion 222 and structures such as the protrusion 312 of the end cap 31, thereby helping to improve the performance of the cylindrical battery 1000.

[0110] In some embodiments, in the axial direction Z of the cylindrical battery 1000, the length of the second portion 412 is L1, in the radial direction X of the cylindrical battery 1000, the length of the third portion 413 is L2, and the distance in the radial direction X between the end of the bent portion 222 close to the axis S and the side of the side wall body 221 away from the axis S is L3, L1+L2≤L3.

[0111] In the embodiment of the present application, L1+L2≤L3 is set. Therefore, in the same plane perpendicular to the axial direction Z, the orthographic projection of the end surface 2221 of the third portion 413 away from the axis S is located within the orthographic projection of the bent portion 222, so as to reduce the influence of the setting of the third portion 413 on the size of the cylindrical battery 1000 in the radial direction X.

[0112] 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 third portion 413 away from the bent portion 222 .

[0113] 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 third portion 413 along the axial direction Z, thereby further reducing the risk of short circuit caused by contact between the busbar and the bent portion 222 .

[0114] 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 .

[0115] In some embodiments, a portion of the insulating film 6 is located on a side of the third portion 413 away from the bent portion 222 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 third portion 413, further reducing the risk of a short circuit caused by contact between the busbar and the bent portion 222.

[0116] In some embodiments, the sidewall body 221 includes a first sub-portion 2211, a second sub-portion 2212 and a third sub-portion 2213, the first sub-portion 2211 surrounds the electrode assembly 1, the third sub-portion 2213 surrounds the end cover assembly 3, and the second sub-portion 2212 is connected between the first sub-portion 2211 and the second sub-portion 2212.

[0117] The first sub-portion 2211, the second sub-portion 2212, and the third sub-portion 2213 may together form an annular sidewall body 221. In the axial direction Z, the end of the first sub-portion 2211 away from the second sub-portion 2212 may be connected to the bottom wall 21, and the end of the third sub-portion 2213 away from the second sub-portion 2212 may be connected to the bent portion 222.

[0118] In some embodiments, the second sub-portion 2212 protrudes from the surface of the first sub-portion 2211 facing the electrode assembly 1 , and the second sub-portion 2212 protrudes from the surface of the third sub-portion 2213 facing the end cap assembly 3 .

[0119] In the axial direction Z, a portion of the second sub-portion 2212 may be located between the end cover assembly 3 and the electrode assembly 1 to play a certain limiting role on the end cover assembly 3 and the electrode assembly 1 in the axial direction Z, thereby helping to improve the stability of the end cover assembly 3 and the electrode assembly 1.

[0120] In some embodiments, a portion of the end cap assembly 3 is located between the bent portion 222 and the second sub-portion 2212 in the axial direction Z. Therefore, in the axial direction Z, the second sub-portion 2212 and the bent portion 222 can clamp the end cap assembly 3 and limit the end cap assembly 3, thereby further improving the stability of the end cap assembly 3.

[0121] In some embodiments, in the axial direction Z, a portion of the second insulating portion 42 is located between the second sub-portion 2212 and the end cover assembly 3 to insulate the second sub-portion 2212 and the end cover assembly 3, thereby reducing the risk of the second sub-portion 2212 contacting the end cover assembly 3 and causing a short circuit.

[0122] In some embodiments, in the radial direction X, another portion of the second insulating portion 42 is located between the end cover assembly 3 and the third sub-portion 2213 to insulate the end cover assembly 3 and the third sub-portion 2213, thereby reducing the risk of contact between the end cover assembly 3 and the third sub-portion 2213 and causing a short circuit.

[0123] In some embodiments, in the axial direction Z, a portion of the second insulating portion 42 is located between the end cover assembly 3 and the bent portion 222, so as to insulate the end cover assembly 3 and the bent portion 222 to a certain extent, further reducing the risk of contact between the end cover assembly 3 and the bent portion 222 and causing a short circuit.

[0124] In some embodiments, in the axial direction Z, the minimum thickness of the portion of the first insulating portion 41 clamped between the end cover assembly 3 and the bent portion 222 is H1, the thickness of the side wall body 221 is H3, and 0.5≤H1 / H3≤2.

[0125] In the embodiment of the present application, the minimum thickness of the first insulating portion 41 in the axial direction Z is the minimum thickness of the first portion 411 in the axial direction Z. As an example, H1 / H3 can be 0.5, 0.6, 0.75, 0.8, 0.9, 1.2, 1.5, 1.8, 2, or a value between any two of the above values.

[0126] In the embodiment of the present application, setting H1 / H3 to be greater than or equal to 0.5 helps increase the thickness of the first insulating portion 41, improves the strength of the first insulating portion 41, and thus enhances the insulation and sealing capabilities of the first insulating portion 41. Furthermore, setting H1 / H3 to be less than or equal to 2 helps reduce the impact of the first insulating portion 41 on the size of the cylindrical battery 1000.

[0127] In some embodiments, 0.3 mm ≤ H1 ≤ 1 mm.

[0128] As an example, the minimum thickness of the portion of the first insulating portion 41 clamped between the end cover assembly 3 and the bent portion 222 in the axial direction Z can 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.

[0129] In the embodiment of the present application, the minimum thickness of the portion of the first insulating portion 41 sandwiched between the end cap assembly 3 and the bent portion 222 in the axial direction Z is set to be greater than or equal to 0.3 mm, which helps to improve the strength of the first insulating portion 41, thereby enhancing the insulation and sealing capabilities of the first insulating portion 41. In addition, the minimum thickness of the portion of the first insulating portion 41 sandwiched between the end cap assembly 3 and the bent portion 222 in the axial direction Z is set to be less than or equal to 1 mm, which helps to reduce the impact of the provision of the first insulating portion 41 on the size of the cylindrical battery 1000.

[0130] In some embodiments, in the radial direction X of the cylindrical battery 1000 , the minimum thickness of the portion of the second insulating portion 42 sandwiched between the end cap assembly 3 and the sidewall body 221 is H4, where 1≤H4 / H1≤1.5.

[0131] As an example, H4 / H1 may be 1, 1.1, 1.25, 1.3, 1.4, 1.45, 1.5, or a value between any two of the above values.

[0132] In the embodiment of the present application, setting H4 / H1 to be greater than or equal to 1 helps increase the thickness of the portion of the second insulating portion 42 sandwiched between the end cap assembly 3 and the side wall body 221, thereby improving the strength of the second insulating portion 42 and thereby enhancing the insulation and sealing capabilities of the second insulating portion 42. Furthermore, setting H4 / H1 to be less than or equal to 1.5 helps reduce the impact of the second insulating portion 42 on the size of the cylindrical battery 1000.

[0133] In some embodiments, 0.3 mm ≤ H4 ≤ 1.5 mm.

[0134] As an example, the minimum thickness of the portion of the second insulating portion 42 clamped between the end cover assembly 3 and the side wall body 221 in the radial direction X can be 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm or a value between any two of the above values.

[0135] In the embodiment of the present application, the minimum thickness of the portion of the second insulating portion 42 clamped between the end cap assembly 3 and the side wall body 221 in the radial direction X is set to be greater than or equal to 0.3 mm, which helps to improve the strength of the second insulating portion 42, thereby improving the insulation and sealing capabilities of the second insulating portion 42. In addition, the portion of the second insulating portion 42 clamped between the end cap assembly 3 and the side wall body 221 in the radial direction X is set to be less than or equal to 1.5 mm, which helps to reduce the impact of the provision of the second insulating portion 42 on the size of the cylindrical battery 1000.

[0136] In some embodiments, in the radial direction X, the width of the gap K1 is G, the thickness of the sidewall body 221 is H3, and 0.25≤G / H3≤2.

[0137] The width G of the gap K1 may be the average radial width of the gap K1. For example, the width G of the gap K1 = (the radial width of the gap K1 at the end closer to the end cover assembly 3 along the axial direction Z + the radial width of the gap K1 at the end farther from the end cover assembly 3 along the axial direction Z) / 2. As an example, G / H3 may be 0.25, 0.5, 0.7, 0.9, 1.1, 1.5, 1.6, 1.8, 2, or a value between any two of the foregoing values.

[0138] In the embodiment of the present application, setting G / H3 to be greater than or equal to 0.25 helps increase the width of gap K1, thereby improving the ability of gap K1 to buffer pressure between the first insulating portion 41 and the second insulating portion 42, and reducing the risk of deformation of the first insulating portion 41 and the second insulating portion 42 under external pressure, thereby creating a gap. Furthermore, setting G / H3 to be less than or equal to 2 helps improve the insulation capacity of the first insulating portion 41 and the second insulating portion 42, thereby reducing the risk of contact between the side wall 22 and the end cap assembly 3 at gap K1, thereby causing a short circuit.

[0139] In some embodiments, 0.2 mm ≤ G ≤ 1 mm.

[0140] As an example, the width G may be 0.2 mm, 0.3 mm, 0.4 mm, 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 0.95 mm, 1 mm, or a value between any two of the above values.

[0141] In the embodiment of the present application, setting the width G to be greater than or equal to 0.2 mm helps improve the ability of the gap K1 to buffer pressure between the first insulating portion 41 and the second insulating portion 42, thereby reducing the risk of deformation of the first insulating portion 41 and the second insulating portion 42 under external pressure, thereby creating a gap. Furthermore, setting the width G to be less than or equal to 1 mm helps improve the insulation capability of the first insulating portion 41 and the second insulating portion 42, thereby reducing the risk of contact between the side wall 22 and the end cap assembly 3 at the gap K1, thereby causing a short circuit.

[0142] In some embodiments, in the axial direction Z, the gap K1 includes a first end K11 close to the end cover assembly 3 and a second end K12 close to the bent portion 222 , and the width of the second end K12 is smaller than the width of the first end K11 .

[0143] In the embodiment of the present application, because the width of the second end K12 of the gap K1 is smaller than the width of the first end K11, at least a portion of the sidewall surface of the gap K1 located between the first end K11 and the second end K12 is an inclined surface, thereby better buffering stress. Furthermore, when the cylindrical battery 1000 is impacted or dropped, causing the bent portion 222 to be pressed downward along the axial direction Z toward the side closer to the bottom wall 21, the greater width of the first end K11 of the gap K1 reduces the risk of stress concentration at the first end K11 of the gap K1, thereby helping to reduce the impact of this stress on the end cap assembly 3.

[0144] Reference Figure 6 , an embodiment of the present application further provides a battery module 3000, the battery module 3000 including a plurality of cylindrical batteries 1000 provided according to any embodiment of the present application.

[0145] In some embodiments, the battery module 3000 further includes a plurality of bus bars (not shown) that connect the plurality of cylindrical batteries 1000 .

[0146] 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 .

[0147] Reference Figure 7 , an embodiment of the present application further provides an electric device 4000, which includes the cylindrical battery 1000 provided in any embodiment of the present application or the battery module 3000 provided in any embodiment of the present application.

[0148] The electrical device 4000 in the embodiments of the present application may be a portable device, an electric toy, a drone, a power tool, an energy storage system, and the like. Power tools include metal cutting power 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 electrical device 4000 described above.

[0149] 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 second insulating portion, wherein at least a portion of the first insulating portion is clamped between the bent portion and the end cover assembly, and at least a portion of the second insulating portion is clamped between the side wall body and the end cover assembly. A gap is provided between the second insulating portion and the first insulating portion, and in the axial direction, the gap is located between the end cover assembly and the bent portion.

2. The cylindrical battery according to claim 1, characterized in that: At least a portion of the first insulating portion is bonded to the end cap assembly.

3. The cylindrical battery according to claim 1 or 2, characterized in that: The first insulating portion includes a first portion and a second portion. In the axial direction of the cylindrical battery, at least a portion of the first portion is located between the bent portion and the end cap assembly and is fixedly connected to the end cap assembly. The second portion protrudes from a surface of the first portion facing the bent portion. In the radial direction of the cylindrical battery, at least a portion of the second portion is located on a side of the bent portion facing the axis.

4. The cylindrical battery according to claim 3, characterized in that: In the radial direction, the second portion covers at least a portion of an end surface of the bent portion facing the axis.

5. The cylindrical battery according to claim 3 or 4, characterized in that: The end cap assembly includes an end cap, the end cap including an end cap body and a protruding portion, wherein in the axial direction, the protruding portion is provided on a side of the end cap body away from the electrode assembly and protrudes relative to the end cap body; In the radial direction, at least a portion of the second portion is disposed between the protruding portion and the bent portion.

6. The cylindrical battery according to any one of claims 3 to 5, characterized in that: The first insulating portion further includes a third portion, the third portion surrounding the second portion and connected to the second portion. In the axial direction, at least a portion of the third portion is located on a side of the bent portion facing away from the electrode assembly.

7. The cylindrical battery according to claim 6, characterized in that: In the same plane perpendicular to the axial direction, the orthographic projection of the end surface of the bending portion facing the axis is located within the orthographic projection of the third part, and the orthographic projection of the end surface of the third part away from the axis is located within the orthographic projection of the bending portion.

8. The cylindrical battery according to claim 6 or 7, characterized in that: The cylindrical battery further includes a second insulating member. In the axial direction, the second insulating member is disposed on a side of the third portion away from the bent portion.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: The sidewall body includes a first sub-section, a second sub-section, and a third sub-section, wherein the first sub-section surrounds the electrode assembly, the third sub-section surrounds the end cap assembly, the second sub-section connects the first sub-section and the third sub-section, and the second sub-section protrudes from a surface of the first sub-section facing the electrode assembly, and the second sub-section protrudes from a surface of the third sub-section facing the end cap assembly; In the axial direction, a portion of the end cover assembly is located between the bent portion and the second sub-portion; In the axial direction, a portion of the second insulating portion is located between the second sub-portion 2212 and the end cover assembly; In the radial direction of the cylindrical battery, another portion of the second insulating portion is located between the end cap assembly and the third sub-portion.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: In the axial direction, the minimum thickness of the portion of the first insulating portion clamped between the end cover assembly and the bent portion is H1, the thickness of the side wall body is H3, 0.5≤H1 / H3≤2, 0.3mm≤H1≤1mm; and / or, In the radial direction of the cylindrical battery, the minimum thickness of a portion of the second insulating portion sandwiched between the end cap assembly and the side wall body is H4, 1≤H4 / H1≤1.5, 0.3mm≤H4≤1.5mm.

11. The cylindrical battery according to any one of claims 1 to 10, characterized in that: In the radial direction of the cylindrical battery, the width of the gap is G, the thickness of the side wall body is H3, 0.25≤G / H3≤2; 0.2mm≤G≤1mm.

12. The cylindrical battery according to any one of claims 1 to 11, characterized in that: In the axial direction, the gap includes a first end close to the end cover assembly and a second end close to the bent portion, and a width of the second end in the radial direction of the cylindrical battery is smaller than a width of the first end in the radial direction.

13. A battery module, characterized in that: The invention comprises a plurality of cylindrical batteries according to any one of claims 1 to 12.

14. An electrical device, characterized in that: The invention comprises a cylindrical battery according to any one of claims 1 to 12.

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