Cylindrical battery, battery pack, and electric device

Abstract

A cylindrical battery (100), a battery pack (200), and an electric device (300). The cylindrical battery (100) comprises a casing (10), an electrode assembly (20), an end cap (30), and a first insulating member (41). The casing (10) has an accommodation cavity (13), the casing (10) comprises a side wall (11), the electrode assembly (20) is arranged in the accommodation cavity (13), the end cap (30) is connected to the electrode assembly (20), and the end cap (30) and the electrode assembly (20) are arranged in the axial direction of the cylindrical battery (100). The first insulating member (41) comprises a first section (411), a second section (412), and a third section (413), wherein the second section (412) is connected to the first section (411) and the third section (413); at least a part of the first section (411) is located between the side wall (11) and the end cap (30), and the first section (411) is connected to the side wall (11) and the end cap (30); and in the axial direction X, at least a part of the third section (413) is located between the end cap (30) and the electrode assembly (20), and the third section (413) is connected to the end cap (30) and the electrode assembly (20). The average thickness of the second section (412) is defined as T2, the average thickness of the third section (413) is defined as T3, and 1 / 4≤T2 / T3≤4 / 5.

Description

Cylindrical batteries, battery packs and electrical devices Technical Field

[0001] This application relates to the field of energy storage technology, and in particular to a cylindrical battery, a battery pack, and an electrical device. Background Technology

[0002] With the rapid development of the lithium battery industry, its application in electric vehicles, electric bicycles, and power tools has become an inevitable trend. Cylindrical batteries, due to their advantages such as good assembly properties and high stability, are highly favored and are increasingly being used in various complex scenarios. Cylindrical batteries typically have insulating components connecting the end caps and the side walls of the casing to provide sealing and insulation. When the electrode components inside a cylindrical battery shift, they can compress the insulating components, affecting the battery's sealing and safety.

[0003] Summary of the Invention

[0004] In view of the above situation, it is necessary to provide a cylindrical battery that reduces the risk of insulation components being squeezed by electrode assemblies, affecting sealing and safety.

[0005] Embodiments of this application provide a cylindrical battery, including a housing, an electrode assembly, an end cap, and a first insulating member. The housing has a receiving cavity and includes a sidewall; the electrode assembly is disposed within the receiving cavity. The end cap connects to the electrode assembly, and the end cap and the electrode assembly are arranged axially along the cylindrical battery. The first insulating member includes a first segment, a second segment, and a third segment; the second segment connects the first segment and the third segment; at least a portion of the first segment is located between the sidewall and the end cap, and connects the sidewall and the end cap. Across the axial direction, at least a portion of the third segment is located between the end cap and the electrode assembly, and connects the end cap and the electrode assembly. The average thickness of the second segment is defined as T2, and the average thickness of the third segment is defined as T3, where 1 / 4 ≤ T2 / T3 ≤ 4 / 5.

[0006] In the aforementioned cylindrical battery, the first insulating component includes a first segment, a second segment, and a third segment. The first segment connects the sidewall and the end cap, serving as insulation and sealing. The third segment connects the end cap and the electrode assembly, serving as insulation and buffering. The second segment connects the first segment and the third segment. Furthermore, the average thickness T2 of the second segment and the average thickness T3 of the third segment satisfy 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly shifts, the second segment has a smaller average thickness and occupies less space, providing a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly's shifting impact on the third segment on the first segment, and reducing the risk of the first segment being excessively compressed, affecting its sealing and safety.

[0007] In one or more embodiments of this application, the average thickness T2 of the second segment and the average thickness T3 of the third segment satisfy 2 / 5≤T2 / T3≤3 / 5. This is beneficial to reduce the impact of the electrode assembly moving and impacting the third segment on the first segment, reduce the risk of the first segment being excessively squeezed, affecting its sealing and safety, and reduce the risk of the second segment breaking due to its smaller thickness.

[0008] In one or more embodiments of this application, the average thickness of the first segment is defined as T1, where T2 < T1. The first segment serves as an insulating seal between the sidewall and the end cap. Compared to the second segment, the first segment has a larger thickness, which is beneficial for improving the insulation and sealing effect between the sidewall and the end cap, thereby enhancing the safety performance of the cylindrical battery. Furthermore, the average thickness T2 of the second segment is simultaneously less than both the average thickness T1 of the first segment and the average thickness T3 of the third segment. This allows the second segment to provide cushioning through deformation, reducing the impact of electrode assembly movement on the first segment when it impacts the third segment, further mitigating the risk of the first segment being excessively compressed, affecting its sealing and safety.

[0009] In one or more embodiments of this application, the average thickness T1 of the first segment satisfies 0.6mm≤T1≤1.3mm, which is beneficial to balance the reliability of the insulation and sealing of the first segment and reduce the impact of its thickness on the space utilization of the cylindrical battery.

[0010] In one or more embodiments of this application, the average thickness T2 of the second segment satisfies 0.15mm≤T2≤1.04mm, which is beneficial to balance the structural reliability and elastic deformation capability of the second segment, reduce the risk of the second segment failing due to excessive thickness, and reduce the risk that the second segment will be excessively compressed due to excessive thickness, affecting the deformation buffer and thus affecting the sealing and safety of the first segment.

[0011] In one or more embodiments of this application, the average thickness T3 of the third segment satisfies 0.6mm≤T3≤1.3mm, which is beneficial to balance the insulation and buffering reliability of the third segment and reduce the impact of its thickness on the length of the cylindrical battery.

[0012] In one or more embodiments of this application, the second segment is provided with a first groove. By providing a first groove in the second segment, the volume occupied by the second segment can be reduced, which is beneficial to increasing the deformation space of the second segment, facilitating elastic deformation of the second segment and providing buffering. This is beneficial to reducing the risk of the first segment being excessively squeezed and undergoing plastic deformation or fatigue failure when the electrode assembly moves. In addition, the first groove is also beneficial to reduce the stiffness of the second segment, making the second segment easier to undergo elastic deformation and reducing the impact on the first segment.

[0013] In one or more embodiments of this application, the thickness of the thinnest region of the second segment is d, where d ≥ 0.1 mm. This helps to reduce the risk of stress concentration in the second segment and the risk of fracture failure in the second segment.

[0014] In one or more embodiments of this application, the first groove is shaped as an arc, triangle, square or trapezoid in a cross-section passing through the axis of the cylindrical battery.

[0015] In one or more embodiments of this application, the projection of the first groove along the axial direction is a closed annulus, which helps to improve the uniformity of each region of the first seal along the circumferential direction and extend the service life of the first seal.

[0016] In one or more embodiments of this application, the end cap includes a base connected to a first segment, a portion of the base protruding axially to form a convex portion, and the convex portion connecting to a third segment. The cylindrical battery also includes a second insulating member disposed in the receiving cavity and connecting the third segment and the electrode assembly. Along the axial direction, the projections of the convex portion, the third segment, the second insulating member, and the electrode assembly overlap. When the electrode assembly shifts, the convex portion can press against the electrode assembly through the third segment and the second insulating member, restricting the movement of the electrode assembly. Furthermore, the overlapping of the third segment and the second insulating member increases the thickness of the buffer for the electrode assembly, which helps reduce the risk of damage to the electrode assembly.

[0017] In one or more embodiments of this application, the sidewall includes a recess that is recessed towards the axis of the cylindrical battery. Along the axial direction, a portion of the second insulating member is located between the recess and the electrode assembly, connecting the recess and the electrode assembly. The second insulating member not only provides insulation and protection, reducing the risk of short circuits between the casing and the electrode assembly, but also acts as a filler, ensuring axial insulation between the recess and the electrode assembly. When the electrode assembly shifts, the recess, through the second insulating member, can limit the movement of the electrode assembly away from the bottom wall, improving the shock and drop resistance of the cylindrical battery. Furthermore, the protrusion and recess can form a mating connection, with the protrusion and recess respectively connecting different positions of the electrode assembly to enhance the limiting effect on the electrode assembly, further improving the shock and drop resistance of the cylindrical battery.

[0018] In one or more embodiments of this application, the third segment does not extend beyond the recess along the axial direction. When the electrode assembly shifts, the impact force generated by the shifting electrode assembly acts first on the recess, or simultaneously on the recess and the third segment. This helps the sidewall withstand the impact force, reducing the impact force on the structure located in the middle region of the top of the cylindrical battery (e.g., the end cap and other parts adjacent to the end cap), and reducing the risk of damage to the structure located in the middle region of the top of the cylindrical battery due to the impact force.

[0019] In one or more embodiments of this application, the projection of the protrusion is located within the projection of the third segment along the axial direction. When the electrode assembly shifts, the protrusion limits the electrode assembly through the third segment and the second insulating member. At this time, the entire axial end face of the protrusion presses against the third segment, which is beneficial for the third segment to support the protrusion and transmit pressure to the second insulating member, which is beneficial for uniform pressure distribution, reducing the risk of stress concentration in the third segment, thereby reducing the risk of fatigue damage to the first insulating member and extending the service life of the first insulating member.

[0020] In one or more embodiments of this application, the projection of the third segment is located within the projection of the second insulating member along the axial direction. When the electrode assembly shifts, the protrusion acts as a limiter for the electrode assembly through the third segment and the second insulating member. At this time, the entire axial end face of the third segment presses against the second insulating member, which helps the second insulating member support the third segment and transmit pressure to the electrode assembly, promotes uniform pressure distribution, reduces the risk of stress concentration in the second insulating member, and extends the service life of the second insulating member.

[0021] In one or more embodiments of this application, the diameter of the cylindrical battery ranges from 30 to 100 mm. The larger size of the cylindrical battery is advantageous for increasing battery capacity. Simultaneously, the smaller average thickness of the second segment of the first insulating member increases the deformation space, facilitating elastic deformation of the second segment and providing cushioning. This reduces the risk of fatigue failure due to excessive compression of the first segment when the electrode assembly shifts, extending the service life of the first insulating member and consequently extending the service life of the large-size battery.

[0022] Embodiments of this application also provide a battery pack, including the cylindrical battery of any of the foregoing embodiments.

[0023] In the aforementioned battery pack, the first insulating component in the cylindrical battery includes a first segment, a second segment, and a third segment. The first segment connects the sidewall and the end cap, serving as insulation and sealing. The third segment connects the end cap and the electrode assembly, serving as insulation and buffering. The second segment connects the first segment and the third segment. Furthermore, the average thickness T2 of the second segment and the average thickness T3 of the third segment satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly shifts, the average thickness of the second segment is smaller, occupying less space and having a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly's shifting impact on the third segment on the first segment. It also helps to reduce the risk of the first segment being over-compressed and experiencing fatigue failure, and reduces the risk of the cylindrical battery affecting the battery pack due to the failure of the first insulating component.

[0024] Embodiments of this application also provide an electrical device, including the cylindrical battery or battery pack of any of the foregoing embodiments.

[0025] In the aforementioned electrical equipment, the first insulating component in the cylindrical battery includes a first segment, a second segment, and a third segment. The first segment connects the sidewall and the end cap, serving as insulation and sealing. The third segment connects the end cap and the electrode assembly, serving as insulation and buffering. The second segment connects the first segment and the third segment. Furthermore, the average thickness T2 of the second segment and the average thickness T3 of the third segment satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly shifts, the second segment has a smaller average thickness and occupies less space, providing greater deformation space within a limited area. This allows the second segment to provide buffering through deformation, reducing the impact of the electrode assembly's shifting impact on the third segment on the first segment. This also reduces the risk of the first segment being over-compressed and experiencing fatigue failure, and lowers the risk of the cylindrical battery affecting the electrical equipment due to the failure of the first insulating component. Attached Figure Description

[0026] Figure 1 is a schematic diagram of the structure of a cylindrical battery in one embodiment of this application.

[0027] Figure 2 is an exploded view of a cylindrical battery in one embodiment of this application.

[0028] Figure 3 is a cross-sectional view of a cylindrical battery through an axis in one embodiment of this application.

[0029] Figure 4 is a magnified view of region IV in Figure 3.

[0030] Figure 5 is a schematic diagram of the structure of the first insulating element in one embodiment of this application.

[0031] Figure 6 is a partial structural schematic diagram of the first insulating element in one embodiment of this application.

[0032] Figure 7 is a schematic diagram of the end cap structure in one embodiment of this application.

[0033] Figure 8 is a cross-sectional view of the end cap in one embodiment of this application.

[0034] Figure 9 is a schematic diagram of the battery pack structure in one embodiment of this application.

[0035] Figure 10 is a schematic diagram of the structure of an electrical device in one embodiment of this application.

[0036] Explanation of main component symbols

[0037] 100 cylindrical batteries

[0038] Casing 10

[0039] Side wall 11

[0040] Recess 111

[0041] Bending section 112

[0042] Bottom wall 12

[0043] Receiving cavity 13

[0044] Electrode assembly 20

[0045] First film 21

[0046] First kneading part 211

[0047] Second pole piece 22

[0048] Second kneading flat section 221

[0049] Diaphragm 23

[0050] End cap 30

[0051] Base 31

[0052] Area 1, 311

[0053] Second Zone 312

[0054] Projection 32

[0055] Connecting part 33

[0056] First insulating component 41

[0057] First paragraph 411

[0058] Second paragraph 412

[0059] First groove 4121

[0060] Third paragraph 413

[0061] Second insulating component 42

[0062] 50 collector disks

[0063] Explosion-proof sheet 60

[0064] Second groove 61

[0065] Bending structure 62

[0066] First structural component 71

[0067] Through hole 711

[0068] Second structural component 72

[0069] Axis 80

[0070] Battery pack 200

[0071] 300 electrical appliances

[0072] Axial X

[0073] The following detailed description, in conjunction with the accompanying drawings, will further illustrate this application. Detailed Implementation

[0074] The technical solutions of the embodiments of this application will be described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments.

[0075] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances. The term "and / or" as used herein includes any and all combinations of one or more of the related listed items.

[0076] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0077] In the description of the embodiments of this application, technical terms such as "first" and "second" are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0078] In the description of the embodiments of this application, the term "perpendicular" is used to describe the ideal state between two components. In actual production or use, two components may exist in a state that is approximately perpendicular. For example, combined with numerical description, perpendicular can refer to the angle between two straight lines within the range of 90±10°, perpendicular can also refer to the dihedral angle between two planes within the range of 90°±10°, and perpendicular can also refer to the angle between a straight line and a plane within the range of 90±10°. The two components described as "perpendicular" do not have to be absolutely straight lines or planes, but can be approximately straight lines or planes. From a macroscopic perspective, if the overall extension direction is a straight line or plane, the component can be considered a "straight line" or "plane".

[0079] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a mutually exclusive, independent, or alternative embodiment. Where there is no conflict, the various embodiments in this application can be combined with each other.

[0080] It should be noted that the thickness, length, width, and other dimensions of various components in the embodiments of this application shown in the accompanying drawings, as well as the overall thickness, length, width, and other dimensions of the integrated device, are merely illustrative examples and should not constitute any limitation on this application.

[0081] Embodiments of this application provide a cylindrical battery, including a housing, an electrode assembly, an end cap, and a first insulating member. The housing has a receiving cavity and includes a sidewall, and the electrode assembly is disposed in the receiving cavity. The end cap connects to the electrode assembly, and the end cap and the electrode assembly are arranged along the axial direction of the cylindrical battery. The first insulating member includes a first segment, a second segment, and a third segment. The second segment connects the first segment and the third segment. At least a portion of the first segment is located between the sidewall and the end cap, and connects the sidewall and the end cap. Along the axial direction, at least a portion of the third segment is located between the end cap and the electrode assembly, and connects the end cap and the electrode assembly. The average thickness of the second segment is defined as T2, the average thickness of the third segment is defined as T3, and 1 / 4 ≤ T2 / T3 ≤ 4 / 5.

[0082] In the aforementioned cylindrical battery, the first insulating component includes a first segment, a second segment, and a third segment. The first segment connects the sidewall and the end cap, serving as insulation and sealing. The third segment connects the end cap and the electrode assembly, serving as insulation and buffering. The second segment connects the first segment and the third segment. Furthermore, the average thickness T2 of the second segment and the average thickness T3 of the third segment satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly shifts, the second segment has a smaller average thickness and occupies less space, providing a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly's shifting impact on the third segment on the first segment, and reducing the risk of the first segment being excessively compressed, affecting its sealing and safety.

[0083] The embodiments of this application will be further described below with reference to the accompanying drawings.

[0084] As shown in Figures 1 to 3, an embodiment of this application provides a cylindrical battery 100, including a housing 10, an electrode assembly 20, and an end cap 30. The housing 10 has a receiving cavity 13 and includes a sidewall 11. The electrode assembly 20 is disposed in the receiving cavity 13. The end cap 30 connects the sidewall 11 and the electrode assembly 20, and the end cap 30 and the electrode assembly 20 are arranged along the axial direction X of the cylindrical battery 100.

[0085] In one embodiment, the housing 10 further includes a bottom wall 12, which connects the side wall 11 and the electrode assembly 20. The electrode assembly 20 and the bottom wall 12 are arranged along the axial direction X.

[0086] In one embodiment, the electrode assembly 20 is electrically connected to the bottom wall 12, the electrode assembly 20 is electrically connected to the end cap 30, the end cap 30 is insulated from the side wall 11, the end cap 30 and the housing 10 form the positive and negative terminals of the cylindrical battery 100, and the cylindrical battery 100 is electrically connected to an external device through the end cap 30 and the housing 10, thereby charging or discharging.

[0087] Here, axial direction X refers to the direction from end cap 30 toward bottom wall 12.

[0088] In one embodiment, both the housing 10 and the end cap 30 are made of metal, which helps to improve the current carrying capacity of the cylindrical battery 100 and reduce the risk of deformation or damage to the housing 10, thereby improving the reliability of the cylindrical battery 100.

[0089] In one embodiment, the cylindrical battery 100 further includes a current collector 50 disposed in the receiving cavity 13. The current collector 50 is located on the side of the electrode assembly 20 opposite to the bottom wall 12 and connects the electrode assembly 20 and the end cap 30. By providing the current collector 50 to connect the electrode assembly 20 and the end cap 30, it is convenient to realize the electrical connection between the end cap 30 and the electrode assembly 20, which helps to simplify the assembly process of the cylindrical battery 100 and improve the assembly efficiency of the cylindrical battery 100.

[0090] In one embodiment, the electrode assembly 20 includes a first electrode 21, a second electrode 22, and a diaphragm 23, with the diaphragm 23 disposed between the first electrode 21 and the second electrode 22. The first electrode 21, the diaphragm 23, and the second electrode 22 are wound together. One of the first electrode 21 and the second electrode 22 is a positive electrode, and the other is a negative electrode.

[0091] In one embodiment, the first electrode 21 is electrically connected to the current collector 50, and the second electrode 22 is electrically connected to the bottom wall 12.

[0092] As shown in Figures 2 to 5, in one embodiment, the cylindrical battery 100 further includes a first insulating member 41. The first insulating member 41 includes a first segment 411, at least a portion of which is located between the end cap 30 and the side wall 11, and connects the end cap 30 and the side wall 11. The first segment 411 can provide insulation and sealing between the end cap 30 and the side wall 11, reducing the risk of short circuit between the end cap 30 and the side wall 11, reducing the risk of electrolyte leakage in the receiving cavity 13, reducing the risk of external impurities entering the receiving cavity 13 of the housing 10, and improving the safety and reliability of the cylindrical battery 100.

[0093] In one embodiment, the first insulating member 41 further includes a third segment 413, which connects to the first segment 411 along the axial direction X. At least a portion of the third segment 413 is located between the end cap 30 and the electrode assembly 20, and connects the end cap 30 and the electrode assembly 20. The third segment 413 provides insulation protection, reducing the risk of short circuit between the end cap 30 and the electrode assembly 20. It also provides buffer protection, reducing the risk of damage to the electrode assembly 20. Furthermore, in the event of movement of the electrode assembly 20, the end cap 30 can press against the electrode assembly 20 via the third segment 413, restricting the movement of the electrode assembly 20.

[0094] In one embodiment, the first insulating member 41 further includes a second segment 412, which connects the first segment 411 and the third segment 413.

[0095] The applicant discovered that when the electrode assembly 20 moves, the electrode assembly 20 applies a force to the third segment 413 in the direction opposite to the axial direction X, causing the third segment 413 to be squeezed and deformed. The squeezing force on the third segment 413 will be transmitted to the first segment 411 through the second segment 412 and squeeze the first segment 411. The first segment 411 is at risk of being damaged by the pressure, which will affect the sealing and safety.

[0096] In one embodiment, the average thickness of the second segment 412 is defined as T2, and the average thickness of the third segment 413 is defined as T3, where T2 < T3. When the electrode assembly 20 shifts, the second segment 412 has a smaller average thickness and occupies less space, providing a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly 20's shifting impact on the third segment 413 on the first segment 411, and reducing the risk of the first segment 411 being excessively compressed, affecting its sealing and safety.

[0097] Taking the second segment 412 as an example, the average thickness is measured as follows: along the direction extending from the first segment 411 towards the third segment 413 on the first insulating member 41, the second segment 412 is divided into 10 equal unit segments. The thickness of all unit segments is measured with a micrometer, and then the average value of all thicknesses is taken as the average thickness of the second segment 412. The average thickness of the first segment 411 and the average thickness of the third segment 413 are measured using the aforementioned method, and will not be repeated here.

[0098] In one embodiment, the average thickness T2 of the second segment 412 and the average thickness T3 of the third segment 413 satisfy 1 / 4≤T2 / T3≤4 / 5, which is beneficial to reduce the impact of the electrode assembly 20 on the first segment 411 when it moves and impacts the third segment 413, reduce the risk of the first segment 411 being excessively squeezed and affecting its sealing and safety, and reduce the risk of the second segment 412 breaking due to its smaller thickness.

[0099] In one embodiment, the average thickness T2 of the second segment 412 and the average thickness T3 of the third segment 413 satisfy 2 / 5≤T2 / T3≤3 / 5, which is beneficial to further reduce the impact of the electrode assembly 20 on the first segment 411 when it moves and impacts the third segment 413, reduce the risk of the first segment 411 being excessively squeezed and affecting its sealing and safety, and reduce the risk of the second segment 412 breaking due to its small thickness.

[0100] In one embodiment, the value of T2 / T3 is any one of 1 / 4, 3 / 10, 7 / 20, 2 / 5, 9 / 20, 1 / 2, 11 / 20, 3 / 5, 13 / 20, 7 / 10, 3 / 4, and 4 / 5. This is beneficial for reducing the impact of the electrode assembly 20 on the first section 411 when it moves and impacts the third section 413, reducing the risk of the first section 411 being excessively compressed and affecting its sealing and safety, and reducing the risk of the second section 412 breaking due to its smaller thickness.

[0101] In one embodiment, the average thickness of the first segment 411 is defined as T1, where T2 < T1. The first segment 411 serves as an insulating seal between the sidewall 11 and the end cap 30. Compared to the second segment 412, the first segment 411 has a larger thickness, which is beneficial for improving the insulation and sealing effect between the sidewall 11 and the end cap 30, thereby improving the safety performance of the cylindrical battery 100. In addition, the average thickness T2 of the second segment 412 is simultaneously less than the average thickness T1 of the first segment 411 and the average thickness T3 of the third segment 413. This is beneficial for the second segment 412 to provide buffering through deformation, reducing the impact of the electrode assembly 20 moving and impacting the third segment 413 on the first segment 411, and further reducing the risk of the first segment 411 being excessively compressed, affecting its sealing and safety.

[0102] In one embodiment, the average thickness T1 of the first segment 411 satisfies 0.6mm ≤ T1 ≤ 1.3mm, which is beneficial for balancing the reliability of the insulation and sealing of the first segment 411 and reducing the impact of its thickness on the space utilization of the cylindrical battery 100. In one embodiment, the thickness of each region of the first segment 411 is the same. In another embodiment, the thickness of each region of the first segment 411 is different.

[0103] In one embodiment, the average thickness T1 of the first segment 411 is any one of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm and 1.3mm, which is beneficial to balance the reliability of the insulation and sealing of the first segment 411 and reduce the impact of its thickness on the space utilization of the cylindrical battery 100.

[0104] In one embodiment, the average thickness T2 of the second segment 412 satisfies 0.15mm ≤ T2 ≤ 1.04mm. This balances the structural reliability and elastic deformation capacity of the second segment 412, reducing the risk of fracture failure due to excessive thickness, and mitigating the impact of excessive thickness on deformation buffering, as well as reducing the risk of excessive compression affecting the sealing and safety of the first segment 411. In one embodiment, the thickness of each region of the second segment 412 is the same. In another embodiment, the thickness of each region of the second segment 412 is different.

[0105] In one embodiment, the average thickness T2 of the second segment 412 is 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.2mm, 0.21mm, 0.22mm, 0.23mm, 0.24mm, 0.25mm, 0.26mm, 0.27mm, 0.28mm, 0.29mm, 0.3mm, 0.32mm, 0.34mm, 0.36mm, 0.38mm, 0.4mm, 0.42mm, 0.44mm, 0.46mm, 0.48mm, 0.5mm, 0.52mm, 0.54mm, 0.56mm, 0.58mm, 0.6mm, 0.62mm, 0. Any of the following thicknesses—64mm, 0.66mm, 0.68mm, 0.7mm, 0.72mm, 0.74mm, 0.76mm, 0.78mm, 0.8mm, 0.82mm, 0.84mm, 0.86mm, 0.88mm, 0.9mm, 0.92mm, 0.94mm, 0.96mm, 0.98mm, 1mm, 1.02mm, and 1.04mm—is beneficial in balancing the structural reliability and elastic deformation capacity of the second segment 412, reducing the risk of fracture failure due to excessive thinness of the second segment 412, and reducing the risk that excessive thickness of the second segment 412 will affect deformation buffering, leading to excessive compression of the first segment 411 and affecting its sealing and safety.

[0106] In one embodiment, the average thickness T3 of the third segment 413 satisfies 0.6mm ≤ T3 ≤ 1.3mm, which is beneficial for balancing the insulation and buffering reliability of the third segment 413 and reducing the impact of its thickness on the length of the cylindrical battery 100. In one embodiment, the thickness of each region of the third segment 413 is the same. In another embodiment, the thickness of each region of the third segment 413 is different.

[0107] In one embodiment, the average thickness T3 of the third segment 413 is any one of 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm and 1.3mm, which is beneficial to balance the insulation buffer reliability of the third segment 413 and reduce the impact of its thickness on the length of the cylindrical battery 100.

[0108] In one embodiment, the average thickness T3 of the third segment 413 is the same as the average thickness T1 of the first segment 411. In another embodiment, the average thickness T3 of the third segment 413 is different from the average thickness T1 of the first segment 411.

[0109] In one embodiment, the second segment 412 is provided with a first groove 4121. By providing the first groove 4121 in the second segment 412, the volume occupied by the second segment 412 can be reduced, which is beneficial to increasing the deformation space of the second segment 412, which is beneficial to the elastic deformation of the second segment 412 and provides buffering. This is beneficial to reducing the risk of the first segment 411 being excessively squeezed and undergoing plastic deformation or fatigue failure when the electrode assembly 20 moves. In addition, the first groove 4121 also helps to reduce the stiffness of the second segment 412, making the second segment 412 easier to undergo elastic deformation and reducing the impact on the first segment 411.

[0110] As shown in Figures 3 to 6, in one embodiment, the thickness of the thinnest region of the second segment 412 is defined as d, where d ≥ 0.1 mm. This helps to reduce the risk of stress concentration on the second segment 412 and reduce the risk of fracture failure of the second segment 412.

[0111] In one embodiment, on a cross-section passing through the axis 80 of the cylindrical battery 100, the shape of the first groove 4121 includes, but is not limited to, any one of the following: arc-shaped (as shown in FIG5), triangular, square, or trapezoidal (as shown in FIG6).

[0112] In one embodiment, the projection of the first groove 4121 along the axial direction X is a closed annulus, which helps to improve the uniformity of each region of the first seal along the circumferential direction and extend the service life of the first seal.

[0113] In one embodiment, the material of the first insulating element 41 includes, but is not limited to, any one of polybutylene terephthalate (PBT), polypropylene (PP), and polyphenylene sulfide (PPS), which helps the first insulating element 41 to play the role of insulation protection and sealing.

[0114] As shown in Figures 2 to 4, in one embodiment, the sidewall 11 includes a recess 111, which is recessed toward the axis 80 of the cylindrical battery 100.

[0115] The cylindrical battery 100 also includes a second insulating member 42, which is disposed in the receiving cavity 13 along the axial direction X. A portion of the second insulating member 42 is located between the recess 111 and the electrode assembly 20, connecting the recess 111 and the electrode assembly 20. The second insulating member 42 not only provides insulation and protection, reducing the risk of short circuit between the housing 10 and the electrode assembly 20, but also acts as a filler, insulating the electrode assembly 20 along the axial direction X of the recess 111. When the electrode assembly 20 shifts, the recess 111, through the second insulating member 42, can limit the movement of the electrode assembly 20 in the direction away from the bottom wall 12, thereby improving the shock resistance and drop resistance of the cylindrical battery 100.

[0116] In one embodiment, the material of the second insulating member 42 includes, but is not limited to, any one of polybutylene terephthalate (PBT), polypropylene (PP), and polyphenylene sulfide (PPS), which helps the second insulating member 42 to play an insulating and protective role, as well as an elastic buffering role, reducing the risk of damage to the electrode assembly 20.

[0117] In one embodiment, along the axial direction X, a portion of the second insulating member 42 is located between the third segment 413 and the electrode assembly 20. When the electrode assembly 20 shifts, the second insulating member 42 and the third segment 413 connect and overlap to press against the electrode assembly 20, which helps to improve the restriction effect on the movement of the electrode assembly 20. Furthermore, the overlap of the second insulating member 42 and the third segment 413 increases the thickness of the buffer for the electrode assembly 20, which helps to reduce the risk of damage to the electrode assembly 20.

[0118] In one embodiment, the second insulating member 42 and the third segment 413 remain connected at all times, which is beneficial for applying pre-pressure to the electrode assembly 20 along the axial direction X and improving the restriction effect on the movement of the electrode assembly 20.

[0119] In one embodiment, the second insulating member 42 is an annular insulating pad with a through hole in the center in the thickness direction to facilitate the exposure of the flattened portion.

[0120] As shown in Figures 2 to 4, 7, and 8, in one embodiment, the end cap 30 includes a protrusion 32 that protrudes toward the electrode assembly 20. The protrusion 32 connects to the third segment 413. Along the axial direction X, the projections of the protrusion 32, the third segment 413, the second insulating member 42, and the electrode assembly 20 overlap. When the electrode assembly 20 shifts, the protrusion 32 can press against the electrode assembly 20 through the third segment 413 and the second insulating member 42, restricting the movement of the electrode assembly 20 and improving the limiting effect on the electrode assembly 20. Furthermore, the protrusion 32 and the recess 111 can form a fit, connecting different positions of the electrode assembly 20 respectively, to improve the limiting effect on the electrode assembly 20 and enhance the shock resistance and drop resistance of the cylindrical battery 100.

[0121] In one embodiment, the projections of the protrusion 32 and the recess 111 are arranged radially along the axial direction X in the cylindrical battery 100. When the electrode assembly 20 shifts, the position where the protrusion 32 presses against the second insulating member 42 via the third segment 413 is different from the position where the recess 111 presses against the second insulating member 42, and they are arranged radially. This helps to increase the area of ​​the second insulating member 42 pressing against the electrode assembly 20, thereby improving the limiting effect on the electrode assembly 20, improving the shock resistance and drop resistance of the cylindrical battery 100, and also helps to reduce the risk of interference and compression of the protrusion 32 by the recess 111, thus extending the service life of the cylindrical battery 100.

[0122] The radial direction of the cylindrical battery 100 refers to the direction from the axis 80 of the cylindrical battery 100 toward the sidewall 11.

[0123] In one embodiment, the projections of the third segment 413 and the recess 111 are arranged radially along the axial direction X in the cylindrical battery 100. When the electrode assembly 20 shifts, the position where the third segment 413 presses against the electrode assembly 20 and the position where the recess 111 presses against the electrode assembly 20 via the second insulating member 42 are different and arranged radially. This arrangement helps to increase the area of ​​the second insulating member 42 pressing against the electrode assembly 20, thereby improving the limiting effect on the electrode assembly 20, improving the shock resistance and drop resistance of the cylindrical battery 100, and also helps to reduce the risk of interference and compression of the third segment 413 by the recess 111, thus extending the service life of the cylindrical battery 100.

[0124] In one embodiment, the end cap 30 further includes a base 31 connected to the first segment 411, and a portion of the base 31 protrudes along the axial direction X to form a protrusion 32. In one embodiment, the protrusion 32 is formed by stamping the base 31.

[0125] In one embodiment, the end cap 30 further includes a connecting portion 33, which connects to the base 31 and extends in a direction opposite to the axial direction X. The connecting portion 33 can serve as a terminal of the cylindrical battery 100 for connecting to external devices.

[0126] In one embodiment, a portion of the connecting portion 33 extends beyond the sidewall 11 in a direction opposite to the axial direction X, facilitating the connection of the connecting portion 33 to an external structure.

[0127] In one embodiment, at least a portion of the structure of the first segment 411 is located between the base 31 and the sidewall 11 to provide insulation and sealing, thereby reducing the risk of short circuits or leakage in the housing 10 and the end cap 30.

[0128] In one embodiment, the end of the sidewall 11 is bent toward the axis 80 in a direction opposite to the axial direction X, forming a bent segment 112. The bent segment 112 and the recess 111 are arranged along the axial direction X, with the radially upward end of the base 31 located between the bent segment 112 and the recess 111. Furthermore, a portion of the structure of the first segment 411 is located between the bent segment 112 and the base 31, and a portion of the structure of the first segment 411 is located between the recess 111 and the base 31. The first segment 411 connects the bent segment 112 and the base 31, and the first segment 411 connects the recess 111 and the base 31. In this embodiment, the sidewall 11 can limit the first insulating member 41 and the base 31 through its own structure, improving the connection stability and reliability between the housing 10 and the end cap 30, enhancing the shock resistance and drop resistance of the cylindrical battery 100, and also simplifying the limiting structure of the end cap 30, reducing the number of accessories of the cylindrical battery 100, saving the cost of the cylindrical battery 100, and improving the space utilization and energy density of the cylindrical battery 100. Simultaneously, this embodiment also helps to increase the connection area between the first insulating member 41 and the sidewall 11, and the connection area between the first insulating member 41 and the end cap 30, improving the sealing effect of the first insulating member 41.

[0129] In one embodiment, the end cap 30 is made by a stamping process, which helps to simplify the processing and manufacturing process of the end cap 30, save the manufacturing cost of the end cap 30, and thus save the cost of the cylindrical battery 100.

[0130] In one embodiment, the end face of the protrusion 32 along the axial direction X is perpendicular to the axial direction X, which is beneficial for the protrusion 32 to apply a uniform force to the electrode assembly 20 and improve the limiting effect on the electrode assembly 20.

[0131] In one embodiment, the third segment 413 does not extend beyond the recess 111 along the axial direction X. When the electrode assembly 20 shifts, the impact force generated by the shifting of the electrode assembly 20 acts first on the recess 111, or simultaneously on the recess 111 and the third segment 413. This helps the sidewall 11 withstand the impact force, reducing the impact of the impact force on the structure located in the middle region of the top of the cylindrical battery 100 (e.g., the end cap 30 and other parts adjacent to the end cap 30), and reducing the risk of damage to the structure located in the middle region of the top of the cylindrical battery 100 caused by the impact force.

[0132] In one embodiment, along the axial direction X, the end face of the third segment 413 is flush with the end region of the recess 111.

[0133] In one embodiment, along the axial direction X, the end of the recess 111 extends beyond the end face of the third segment 413.

[0134] In one embodiment, along the axial direction X, a portion of the third segment 413 extends beyond the recess 111. In one embodiment, the dimension by which the third segment 413 extends beyond the recess 111 along the axial direction X is no greater than 0.5 mm, which helps to reduce the impact of electrode assembly 20 movement on the structure located in the middle region of the top of the cylindrical battery 100, and reduces the risk of impact force damaging the structure located in the middle region of the top of the cylindrical battery 100.

[0135] In one embodiment, the base 31 includes a first region 311 and a second region 312, the first region 311 being connected to the connecting portion 33, and the protrusion 32 being connected to the first region 311 and the second region 312. Viewed along the axial direction X, the first region 311 surrounds the connecting portion 33, and the second region 312 surrounds the protrusion 32 and the first region 311.

[0136] In one embodiment, in the axial direction X, the first region 311 is closer to the electrode assembly 20 than the second region 312, which helps to reduce the height of the connection portion 33 relative to the electrode assembly 20, reduce the overall length of the cylindrical battery 100, and increase the energy density of the cylindrical battery 100.

[0137] In one embodiment, along the axial direction X, the length of the protrusion 32 extending beyond the first region 311 is defined as L1, where 1 mm ≤ L1 ≤ 1.3 mm. This range of values ​​for the length L1 of the protrusion 32 extending beyond the first region 311 helps to limit the movement of the protrusion 32 when the electrode assembly 20 shifts, improving the shock resistance and drop resistance of the cylindrical battery 100. Simultaneously, this range also helps to reduce the impact of the end cap 30 on the length of the cylindrical battery 100, improving the space utilization and energy density of the cylindrical battery 100.

[0138] In one embodiment, the length L1 of the protrusion 32 extending beyond the first region 311 is any one of 1 mm, 1.05 mm, 1.1 mm, 1.15 mm, 1.2 mm, 1.25 mm, and 1.3 mm.

[0139] In one embodiment, the thickness D of the base 31 along the axial direction X is 0.8mm-1mm, which is beneficial to balance the structural strength of the base 31 and reduce the impact of the thickness of the base 31 on the length of the cylindrical battery 100.

[0140] In one embodiment, along the axial direction X, the projection of the protrusion 32 lies within the projection of the third segment 413. When the electrode assembly 20 shifts, the protrusion 32, through the third segment 413 and the second insulating member 42, limits the electrode assembly 20. At this time, the entire end face of the protrusion 32 along the axial direction X presses against the third segment 413, which is beneficial for the third segment 413 to support the protrusion 32 and transmit pressure to the second insulating member 42. This facilitates uniform pressure distribution, reduces the risk of stress concentration in the third segment 413, thereby reducing the risk of fatigue damage to the first insulating member 41 and extending its service life.

[0141] The projection of the protrusion 32 along the axial direction X refers to the projection of the upper end face of the protrusion 32 along the axial direction X, that is, the projected area of ​​the annular region with a width of L2 in the radial direction.

[0142] In one embodiment, along the axial direction X, the projection of the third segment 413 lies within the projection of the second insulating member 42. When the electrode assembly 20 shifts, the protrusion 32, through the third segment 413 and the second insulating member 42, limits the electrode assembly 20. At this time, the entire end face of the third segment 413 along the axial direction X presses against the second insulating member 42, which helps the second insulating member 42 support the third segment 413 and transmit pressure to the electrode assembly 20, promotes uniform pressure distribution, reduces the risk of stress concentration in the second insulating member 42, and extends the service life of the second insulating member 42.

[0143] In one embodiment, along the axial direction X, the area of ​​the projected region of the protrusion 32 is defined as S1, and the area of ​​the electrode assembly 20 is defined as S2, where 0.04 ≤ S1 / S2 ≤ 0.3. When the electrode assembly 20 shifts, the ratio of the projected area S1 of the protrusion 32 to the projected area S2 of the electrode assembly satisfies this range, which is beneficial to improving the limiting effect of the protrusion 32 on the electrode assembly 20, reducing the impact of the width of the protrusion 32 on the space utilization rate within the receiving cavity 13, reducing the impact of the width of the protrusion 32 on the energy density of the cylindrical battery 100, and reducing the risk of the second insulating member 42 coming into contact with the recess 111 and being squeezed by the recess 111, thereby extending the service life of the second insulating member 42.

[0144] In one embodiment, 0.06≤S1 / S2≤0.3 is beneficial to both improve the limiting effect of the protrusion 32 on the electrode assembly 20 and reduce the impact of the width of the protrusion 32 on the space utilization rate of the receiving cavity 13.

[0145] In one embodiment, 0.18≤S1 / S2≤0.24 is beneficial to further improve the limiting effect of the protrusion 32 on the electrode assembly 20 and reduce the impact of the width of the protrusion 32 on the space utilization rate of the receiving cavity 13.

[0146] In one embodiment, the value of S1 / S2 is any one of 0.04, 0.06, 0.08, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28 and 0.3, which is beneficial to both improve the limiting effect of the protrusion 32 on the electrode assembly 20 and reduce the impact of the width of the protrusion 32 on the space utilization rate within the receiving cavity 13.

[0147] In one embodiment, the projection area of ​​the protrusion 32 along the axial direction X is annular. The inner radius r1 and outer radius r2 of the annular projection can be calculated using a Keyence IM 8000 tester to calculate the projection area S1 of the protrusion 32, where S1 = π*(r2)^2 - π*(r1)^2, and π is taken as 3.14.

[0148] In one embodiment, the radius of the outer contour of the electrode assembly 20 can be obtained by taking 20 points evenly around the outer contour of the electrode assembly 20 using a Keyence IM 8000 tester, fitting the center of the circle by taking the points, calculating the distance from the 20 points to the center of the circle, taking the average value to obtain the radius of the electrode assembly 20, and calculating the cross-sectional area S2 of the electrode assembly 20, where π is taken as 3.14.

[0149] In one embodiment, the width of the protrusion 32 along the radial direction of the cylindrical battery 100 is defined as L2, where 0.7mm ≤ L2 ≤ 11.1mm. This is beneficial for balancing the limiting effect of the protrusion 32 on the electrode assembly 20 and reducing the impact of the protrusion 32 on the space utilization and energy density of the cylindrical battery 100. The radial width L2 of the protrusion 32 refers to the width of the end face of the protrusion 32 along the axial direction X.

[0150] In one embodiment, the width L2 of the protrusion 32 is 0.7mm, 0.9mm, 1.1mm, 1.3mm, 1.5mm, 1.7mm, 1.9mm, 2.1mm, 2.3mm, 2.5mm, 2.7mm, 2.9mm, 3.1mm, 3.3mm, 3.5mm, 3.7mm, 3.9mm, 4.1mm, 4.3mm, 4.5mm, 4.7mm, 4.9mm, 5.1mm, 5.3mm, 5.5mm, 5.7mm, 5.9mm, 6.1mm, 6.3mm, 6.5mm, 6... Any of the following sizes—7mm, 6.9mm, 7.1mm, 7.3mm, 7.5mm, 7.7mm, 7.9mm, 8.1mm, 8.3mm, 8.5mm, 8.7mm, 8.9mm, 9.1mm, 9.3mm, 9.5mm, 9.7mm, 9.9mm, 10.1mm, 10.3mm, 10.5mm, 10.7mm, 10.9mm, and 11.1mm—is beneficial in balancing the limiting effect of the protrusion 32 on the electrode assembly 20 with reducing the impact of the protrusion 32 on the space utilization and energy density of the cylindrical battery 100.

[0151] In one embodiment, along the axial direction X, the area of ​​the projected region of the base 31 is defined as S3, where 0.06 ≤ S1 / S3 ≤ 0.45. When the electrode assembly 20 shifts, the ratio of the projected area S1 of the protrusion 32 to the projected area S2 of the base 31 satisfies this range, which is beneficial to improving the limiting effect of the protrusion 32 on the electrode assembly 20, reducing the impact of the width of the protrusion 32 on the space utilization rate within the receiving cavity 13, reducing the impact of the width of the protrusion 32 on the energy density of the cylindrical battery 100, and reducing the risk of the second insulating member 42 coming into contact with the recess 111 and being squeezed by the recess 111, thereby extending the service life of the second insulating member 42.

[0152] In one embodiment, the projected area of ​​the base 31 along the axial direction X is annular, and the radial width of this annular area is L3. The projected area of ​​the base 31 along the axial direction X is the projected area of ​​the annular area of ​​width L3 formed by the base 31, not the outer contour area of ​​the projected area of ​​the base 31. In one embodiment, the inner radius r3 and outer radius r4 of the annular projection can be calculated using a Keyence IM 8000 tester to calculate the projected area S3 of the base 31, where S3 = π*(r4)^2 - π*(r3)^2, and π is taken as 3.14.

[0153] In one embodiment, 0.09≤S1 / S3≤0.36 is beneficial to both improve the limiting effect of the protrusion 32 on the electrode assembly 20 and reduce the impact of the width of the protrusion 32 on the space utilization rate of the receiving cavity 13.

[0154] In one embodiment, the ratio of the projected area S1 of the protrusion 32 to the projected area S3 of the base 31 is any one of 0.06, 0.08, 0.09, 0.1, 0.12, 0.14, 0.16, 0.18, 0.2, 0.22, 0.24, 0.26, 0.28, 0.3, 0.32, 0.34, 0.36, 0.38, 0.4, 0.42, 0.44, and 0.45. This is beneficial for balancing the limiting effect of the protrusion 32 on the electrode assembly 20 and reducing the impact of the width of the protrusion 32 on the space utilization rate within the receiving cavity 13.

[0155] In one embodiment, the cylindrical battery 100 further includes an explosion-proof sheet 60, which is disposed in the receiving cavity 13. The explosion-proof sheet 60 is located on the side of the current collector 50 away from the electrode assembly 20. The explosion-proof sheet 60 connects the current collector 50 and the end cap 30. When the gas pressure in the receiving cavity 13 exceeds the upper limit that the explosion-proof sheet 60 can withstand, the gas in the receiving cavity 13 can break through the explosion-proof sheet 60, thereby achieving the purpose of pressure relief. This helps to reduce the risk of the cylindrical battery 100 exploding due to excessive internal gas pressure and improves the safety performance of the cylindrical battery 100.

[0156] In one embodiment, the explosion-proof sheet 60 is provided with a second groove 61 recessed along the axial direction X. The second groove 61 reduces the local thickness of the explosion-proof sheet 60, thereby forming a weak area. This weak area can be damaged when the gas pressure in the receiving cavity 13 is too high, thereby forming a pressure relief channel.

[0157] In one embodiment, a portion of the explosion-proof sheet 60 is located between the protrusion 32 and the third segment 413, and the explosion-proof sheet 60 connects the protrusion 32 and the third segment 413. The protrusion 32 and the third segment 413 can clamp and limit the explosion-proof sheet 60, which helps to reduce the risk of the explosion-proof sheet 60 shaking and improves the shock resistance and drop resistance of the cylindrical battery 100.

[0158] In one embodiment, the radially upward end of the explosion-proof sheet 60 is a bent structure 62, which wraps around the edge of the base 31, thereby improving the connection stability between the explosion-proof sheet 60 and the end cap 30, and further improving the shock resistance and drop resistance of the cylindrical battery 100. In one embodiment, the bent structure 62 wraps around the edge of the second region 312.

[0159] In one embodiment, at least a portion of the structure of the first segment 411 is located between the bent structure 62 and the sidewall 11, and the first segment 411 connects the bent structure 62 and the sidewall 11 to achieve an insulating and sealing effect.

[0160] In one embodiment, the cylindrical battery 100 further includes a first structural member 71, which is disposed between the explosion-proof sheet 60 and the current collector 50 and connects the explosion-proof sheet 60 and the current collector 50, so that the current collector 50 and the explosion-proof sheet 60 are electrically connected.

[0161] In one embodiment, the first structural member 71 is provided with a through hole 711, which can serve as a channel for the flow of gas or electrolyte, so that the gas or liquid in the receiving cavity 13 can act on the explosion-proof sheet 60 through the through hole 711, thereby reducing the risk of the cylindrical battery 100 exploding due to excessive internal gas pressure.

[0162] In one embodiment, a portion of the separator 23 extends beyond the second electrode 22 in a direction opposite to the axial direction X, and a portion of the first electrode 21 extends beyond the separator 23. The portion of the first electrode 21 extending beyond the separator 23 is flattened to form a first flattened portion 211, which connects to the current collector 50. By providing the first flattened portion 211 to connect to the current collector 50, the connection process between the first electrode 21 and the current collector 50 is simplified, improving the assembly efficiency of the cylindrical battery 100 and enhancing the connection stability between the first electrode 21 and the current collector 50. In one embodiment, the first flattened portion 211 and the current collector 50 are welded together.

[0163] In one embodiment, along the axial direction X, a portion of the separator 23 extends beyond the first electrode 21, and a portion of the second electrode 22 extends beyond the separator 23. The portion of the second electrode 22 extending beyond the separator 23 is flattened to form a second flattened portion 221, which connects to the bottom wall 12. By providing the second flattened portion 221 to connect to the bottom wall 12, the connection process between the second electrode 22 and the bottom wall 12 is simplified, improving the assembly efficiency of the cylindrical battery 100 and enhancing the connection stability between the second electrode 22 and the bottom wall 12. In one embodiment, the second flattened portion 221 and the bottom wall 12 are welded together.

[0164] In one embodiment, the cylindrical battery 100 further includes a second structural member 72, which is disposed between the bottom wall 12 and the second flattened portion 221 and connects the bottom wall 12 and the second flattened portion 221. By providing the second structural member 72 to connect the bottom wall 12 and the second flattened portion 221, it is beneficial to simplify the connection process between the second electrode 22 and the bottom wall 12 and improve the assembly efficiency of the cylindrical battery 100.

[0165] In one embodiment, the second structural member 72 and the bottom wall 12 are welded together, which helps to improve the connection stability between the second structural member 72 and the bottom wall 12.

[0166] In one embodiment, the second structural member 72 and the second flattened portion 221 are welded together, which helps to improve the connection stability between the second structural member 72 and the second electrode 22.

[0167] In one embodiment, the diameter of the cylindrical battery 100 ranges from 30 to 100 mm. The larger size of the cylindrical battery 100 is advantageous for increasing battery capacity. Simultaneously, the smaller average thickness of the second segment 412 of the first insulating member 41 increases deformation space, facilitating elastic deformation of the second segment 412 and providing cushioning. This reduces the risk of fatigue failure due to excessive compression of the first segment 411 when the electrode assembly 20 shifts, extending the service life of the first insulating member 41 and consequently extending the service life of the large-size battery.

[0168] drop test

[0169] To verify the reliability of the cylindrical battery 100 in this application, multiple sets of embodiment and comparative tests were conducted, as follows:

[0170] In each embodiment, there are 12 cylindrical batteries, which are the cylindrical batteries 100 described in any of the foregoing embodiments of this application.

[0171] Each comparative example contains 12 cylindrical batteries.

[0172] Drop tests were conducted on each of the aforementioned examples and comparative examples. After all examples and comparative examples had completed the tests, the number of those that passed the test and the number that failed the test in each group were counted, as shown in Table 1.

[0173] The drop test method is as follows: place the cylindrical battery vertically with the bottom facing down at a height of 1.2 meters, and let it fall freely. Then observe whether the end cap of the cylindrical battery leaks liquid.

[0174] After the tests are completed, count the number of tests that passed and the number of tests that failed in each test group.

[0175] The test is judged as follows: no liquid seepage is detected on the outer surface of the casing. The test is judged as follows: liquid seepage is detected on the outer surface of the casing.

[0176] Table 1

[0177] As can be seen from Table 1 above, the cylindrical battery 100 adopted in the embodiment of this application has good drop resistance and shock resistance.

[0178] In summary, in the cylindrical battery 100 of this application, the first insulating member 41 includes a first segment 411, a second segment 412, and a third segment 413. The first segment 411 connects the side wall 11 and the end cap 30, serving as insulation and sealing. The third segment 413 connects the explosion-proof sheet 60 and the electrode assembly 20, serving as insulation and buffering. The second segment 412 connects the first segment 411 and the third segment 413. Furthermore, the average thickness T2 of the second segment 412 and the average thickness T3 of the third segment 413 satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly 20 moves, the average thickness of the second segment 412 is smaller, occupying less space and having a larger elastic deformation space in a limited area. This is beneficial for providing buffering through deformation, reducing the impact of the electrode assembly 20 moving and impacting the third segment 413 on the first segment 411, and reducing the risk of the first segment 411 being excessively squeezed, affecting its sealing and safety.

[0179] As shown in Figure 9, an embodiment of this application also provides a battery pack 200, including the cylindrical battery 100 in any of the foregoing embodiments.

[0180] In the aforementioned battery pack 200, the first insulating component 41 in the cylindrical battery 100 includes a first segment 411, a second segment 412, and a third segment 413. The first segment 411 connects the side wall 11 and the end cap 30, serving as insulation and sealing. The third segment 413 connects the explosion-proof sheet 60 and the electrode assembly 20, serving as insulation and buffering. The second segment 412 connects the first segment 411 and the third segment 413. Furthermore, the average thickness T2 of the second segment 412 and the average thickness T3 of the third segment 413 satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly 20 shifts, the average thickness of the second segment 412 is smaller, occupying less space and having a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly 20 shifting and impacting the third segment 413 on the first segment 411, reducing the risk of the first segment 411 being excessively compressed, affecting its sealing and safety, and reducing the risk of the cylindrical battery 100 being affected by the failure of the first insulating component 41.

[0181] As shown in Figure 10, an embodiment of this application also provides an electrical device 300, including the cylindrical battery 100 or battery pack 200 in any of the foregoing embodiments.

[0182] In the aforementioned electrical equipment 300, the first insulating component 41 in the cylindrical battery 100 includes a first segment 411, a second segment 412, and a third segment 413. The first segment 411 connects the side wall 11 and the end cap 30, serving as insulation and sealing. The third segment 413 connects the explosion-proof sheet 60 and the electrode assembly 20, serving as insulation and buffering. The second segment 412 connects the first segment 411 and the third segment 413. Furthermore, the average thickness T2 of the second segment 412 and the average thickness T3 of the third segment 413 satisfy: 1 / 4 ≤ T2 / T3 ≤ 4 / 5. When the electrode assembly 20 shifts, the average thickness of the second segment 412 is smaller, occupying less space and having a larger elastic deformation space in a limited area. This helps to provide buffering through deformation, reducing the impact of the electrode assembly 20's shifting impact on the third segment 413 on the first segment 411, reducing the risk of the first segment 411 being excessively compressed, affecting its sealing and safety, and reducing the risk of the cylindrical battery 100 affecting the electrical equipment 300 due to the failure of the first insulating component 41.

[0183] In one embodiment, the electrical equipment 300 includes, but is not limited to, electric vehicles, drones, electric two-wheelers, home appliances, consumer electronics, and power tools.

[0184] In addition, those skilled in the art may make other changes within the spirit of this application. Of course, all such changes made in accordance with the spirit of this application should be included within the scope disclosed in this application.

Claims

1. A cylindrical battery, characterized in that, include: A housing having a receiving cavity, the housing including sidewalls; Electrode assembly is disposed in the receiving cavity; An end cap is connected to the electrode assembly, and the end cap and the electrode assembly are arranged along the axial direction of the cylindrical battery; A first insulating element includes a first segment, a second segment, and a third segment, wherein the second segment connects the first segment and the third segment, and at least a portion of the first segment is located between the sidewall and the end cap, and connects the sidewall and the end cap; Along the axial direction, at least a portion of the third segment is located between the end cap and the electrode assembly, and connects the end cap and the electrode assembly; The average thickness of the second segment is defined as T2, and the average thickness of the third segment is defined as T3, where 1 / 4 ≤ T2 / T3 ≤ 4 / 5.

2. The cylindrical battery as described in claim 1, characterized in that, 2 / 5≤T2 / T3≤3 / 5.

3. The cylindrical battery as described in claim 1 or 2, characterized in that, The average thickness of the first segment is defined as T1, where T2 < T1.

4. The cylindrical battery according to any one of claims 1 to 3, characterized in that, The average thickness of the first segment is defined as T1, satisfying 0.6mm ≤ T1 ≤ 1.3mm; and / or, The average thickness T2 of the second segment satisfies 0.15mm ≤ T2 ≤ 1.04mm; and / or, The average thickness T3 of the third segment satisfies 0.6mm≤T3≤1.3mm.

5. The cylindrical battery according to any one of claims 1 to 4, characterized in that, The second segment has a first groove.

6. The cylindrical battery as described in claim 5, characterized in that, The thickness of the thinnest region in the second segment is d, where d ≥ 0.1 mm.

7. The cylindrical battery as described in claim 5 or 6, characterized in that, On a cross-section passing through the axis of the cylindrical battery, the shape of the first groove is any one of an arc, a triangle, a square, or a trapezoid.

8. The cylindrical battery according to any one of claims 5 to 7, characterized in that, Along the axial direction, the projection of the first groove is a closed annulus.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that, The end cap includes a base that connects to the first segment, and a portion of the base protrudes along the axial direction to form a protrusion that connects to the third segment; The cylindrical battery further includes a second insulating member, which is disposed in the receiving cavity and connects the third segment and the electrode assembly; Along the axial direction, the projections of the protrusion, the third segment, the second insulating member, and the electrode assembly overlap.

10. The cylindrical battery as described in claim 9, characterized in that, The sidewall includes a recess that is recessed toward the axis of the cylindrical battery; Along the axial direction, a portion of the second insulating member is located between the recess and the electrode assembly, and connects the recess and the electrode assembly.

11. The cylindrical battery as described in claim 10, characterized in that, Along the axial direction, the third segment does not extend beyond the recess.

12. The cylindrical battery as described in claim 9 or 10, characterized in that, Along the axial direction, the projection of the protrusion lies within the projection of the third segment; and / or, Along the axial direction, the projection of the third segment lies within the projection of the second insulating element.

13. The cylindrical battery according to any one of claims 1-12, characterized in that, The diameter of the cylindrical battery ranges from 30 to 100 mm.

14. A battery pack, characterized in that, Including the cylindrical battery as described in any one of claims 1 to 13.

15. An electrical appliance, characterized in that, Includes a cylindrical battery as described in any one of claims 1 to 13, or a battery pack as described in claim 14.

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