Cylindrical battery, battery pack and electric equipment

Abstract

The invention discloses a cylindrical battery, a battery pack and electric equipment. The cylindrical battery comprises an electrode assembly and a shell, the electrode assembly is contained in the shell, the shell comprises a side wall arranged around the electrode assembly, the side wall comprises a side wall main body and a thinning part connected to the side wall main body, the thinning part extends in the circumferential direction of the cylindrical battery, the minimum thickness of the thinning part is T1, the thickness of the side wall main body is T2, and T1 / T2 is larger than or equal to 0.2 and smaller than or equal to 0.4. Therefore, the shell has relatively high strength, and the thinned part can be broken when the internal air pressure of the cylindrical battery is too large so as to timely relieve pressure, so that the safety performance is improved while the structural stability of the cylindrical battery is balanced.

Description

Technical Field

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

[0002] Rechargeable batteries are batteries that can be recharged to activate the active materials after being discharged and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, drones, etc.

[0003] The development of battery technology takes into account many design factors, such as energy density, cycle life, assembly efficiency, processing technology, etc., as well as battery reliability. Summary of the invention

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

[0005] In the first aspect, the present application provides a cylindrical battery, which includes an electrode assembly and a shell. The electrode assembly is contained in the shell, and the shell includes a side wall arranged around the electrode assembly, and the side wall includes a side wall body and a thinning portion connected to the side wall body, and the thinning portion extends along the circumference of the cylindrical battery. The minimum thickness of the thinning portion is T1, and the thickness of the side wall body is T2, 0.2≤T1 / T2≤0.4. As a result, the shell has a high strength, and the thinning portion can be ruptured when the internal air pressure of the cylindrical battery is too high so as to release the pressure in time, which is conducive to balancing the structural stability of the cylindrical battery and improving the safety performance of the battery.

[0006] In one or more optional embodiments above, 0.2mm≤T2≤0.6mm. T2 is greater than or equal to 0.2mm, which is beneficial to improving the mechanical strength of the side wall body, thereby improving the overall strength of the side wall; T2 is less than or equal to 0.6mm, which can reduce the weight of the side wall body and reduce the space occupied by the side wall as a whole, which is beneficial to improving the energy density of the cylindrical battery.

[0007] In one or more of the above optional embodiments, the thinned portion has a first end and a second end opposite to each other in the circumferential direction, and the first end and the second end are spaced apart in the circumferential direction. After the thinned portion ruptures to form a fracture, the two parts of the side wall located on both sides of the fracture can be connected by the part of the side wall body located between the first end and the second end, thereby reducing the risk of the side wall being broken into two completely separated parts.

[0008] In one or more of the above optional embodiments, the thinning portion is in the shape of an arc; the central angle corresponding to the thinning portion is 240°-330°, and can be optionally 270°-300°. γ is greater than or equal to 240°, and the length of the thinning portion extending along the circumference of the cylindrical battery does not account for too small a proportion of the entire circumference of the circle where the thinning portion is located, and the thinning portion can be broken in time; γ is less than or equal to 330°, and the portion of the side wall body between the first end and the second end is not too small, which is conducive to reducing the risk of the portion being pulled apart when the thinning portion breaks, causing the side wall to explode into two completely separated parts, thereby reducing the safety hazards of the cylindrical battery.

[0009] In one or more of the above optional embodiments, the housing includes a bottom wall, the cylindrical battery includes an end cover and an explosion-proof valve disposed on the end cover, the bottom wall and the end cover are disposed along the axial direction of the cylindrical battery, and the two ends of the side wall are respectively connected to the bottom wall and the end cover; along the axial direction, the distance between the thinning portion and the bottom wall is greater than the distance between the thinning portion and the end cover. Under different internal pressures, the cylindrical battery can release pressure in different directions through two pressure relief structures, which is conducive to improving the pressure relief efficiency and further improving the safety performance and reliability of the cylindrical battery.

[0010] In one or more optional embodiments above, the spacing between the thinning portion and the bottom wall along the axial direction is 3mm-15mm, and can be optionally 4mm-7mm. The spacing between the thinning portion and the bottom wall is greater than or equal to 3mm, which can reduce the stress from the bottom wall on the thinning portion, and is conducive to the timely rupture of the thinning portion when the cylindrical battery is in thermal runaway. The spacing between the thinning portion and the bottom wall is less than or equal to 15mm. When the pressure inside the cylindrical battery is too high, the thinning portion does not require too much turning space when it ruptures, which is conducive to improving the pressure relief effect.

[0011] In one or more optional embodiments above, the size of the side wall is 40 mm-210 mm in the axial direction. The size of the side wall is greater than or equal to 40 mm, which is conducive to increasing the size of the electrode assembly that can be accommodated by the shell and improving the capacity of the cylindrical battery. The size of the side wall is less than or equal to 210 mm, which can shorten the gas exhaust path inside the cylindrical battery, reduce the difficulty of gas exhaust, and improve the exhaust efficiency.

[0012] In one or more of the above optional embodiments, the bursting pressure of the thinned portion is greater than the bursting pressure of the explosion-proof valve. The explosion-proof valve may burst before the thinned portion, and the cylindrical battery may be depressurized by flipping and bursting the explosion-proof valve first, which may reduce the possibility of rupture of the thinned portion and reduce electrolyte leakage, short circuit and other phenomena that may be caused by shell rupture. When the venting passage of the explosion-proof valve is blocked by the electrode assembly, or by the electrolyte, pole piece and diaphragm residue, etc., resulting in the pressure in the cylindrical battery continuing to increase, the thinned portion may burst to exhaust gas, which is beneficial to improve the pressure relief efficiency.

[0013] In one or more of the above optional embodiments, the outer surface of the side wall is recessed to form a thinning portion; and / or the inner surface of the side wall is recessed to form a thinning portion. The thinning portion can be formed by stamping, cutting or other suitable methods, and the forming process is simple, which is conducive to improving the production efficiency of cylindrical batteries.

[0014] In one or more optional embodiments above, the side wall is provided with a concave portion to form a thinning portion, and the cross section of the concave portion coplanar with the axis of the cylindrical battery is triangular or trapezoidal. The thickness of the thinning portion along the radial direction of the cylindrical battery is gradual, which is more conducive to the thinning portion rupturing at the part with the smallest thickness, thereby releasing the pressure inside the cylindrical battery.

[0015] In one or more optional embodiments above, the side wall forms a thinning portion by setting a recess; the cross section of the recess coplanar with the axis of the cylindrical battery includes a first straight side and a second straight side, the first straight side and the second straight side are respectively located on both sides of a virtual straight line, the virtual straight line is perpendicular to the axis and intersects with the axis; the angle between the first straight side and the virtual straight line is α, and the angle between the second straight side and the virtual straight line is β, α≤β. Thus, it is beneficial to reduce the deviation of the bursting pressure of the thinning portion, improve the consistency of the bursting pressure of the thinning portion, reduce the risk of accidental bursting of the thinning portion under a smaller pressure less than its set bursting pressure value, and reduce the risk of the thinning portion not bursting under a larger pressure greater than its set bursting pressure value, and also help to improve the directional consistency of the bursting of the thinning portion, thereby improving the bursting stability of the thinning portion.

[0016] In one or more optional embodiments above, 10°≤β-α≤40°. β-α is greater than or equal to 10°, which is beneficial to reducing the deviation of the bursting pressure of the thinning portion and improving the bursting stability and directional consistency of the thinning portion. β-α is less than or equal to 40°, which can reduce the stress influence from the side wall body on the part with the smallest thickness of the thinning portion, which is beneficial to the timely bursting of the thinning portion when the cylindrical battery is thermally runaway.

[0017] In one or more optional embodiments above, 60°≤α+β≤150°. α+β is greater than or equal to 60°, and the dimension of the thinning portion along the axial direction X of the cylindrical battery is not too small, which is conducive to the thinning portion turning outward and deforming under the pressure inside the cylindrical battery, thereby facilitating the smooth explosion of the thinning portion. α+β is less than or equal to 150°, and the dimension of the thinning portion along the axial direction X of the cylindrical battery is not too large, which is conducive to reducing the impact on the overall structural strength of the side wall.

[0018] In one or more optional embodiments above, 20°≤α≤60°. α is greater than or equal to 20°, which is beneficial to reducing the stress effect on the thinned portion with the smallest thickness from the side wall body, thereby facilitating the smooth explosion of the thinned portion. α is less than or equal to 60°, and the size of the thinned portion along the axial direction X of the cylindrical battery is not too large, which is beneficial to reducing the impact on the overall structural strength of the side wall.

[0019] In one or more optional embodiments above, the shell includes a bottom wall, the bottom wall is connected to the side wall, and the bottom wall and the electrode assembly are arranged along the axial direction of the cylindrical battery; along the axial direction, the spacing between the thinned portion and the bottom wall is 3mm-15mm, and the second straight side is closer to the bottom wall than the first straight side. Thus, the overall thickness of the portion of the thinned portion corresponding to the second straight side can be reduced, so as to be more conducive to the portion to overcome the stress and turn outward and deform, thereby improving the blasting orientation consistency of the thinned portion.

[0020] In a second aspect, the present application provides a battery pack comprising a cylindrical battery according to any embodiment of the first aspect.

[0021] In a third aspect, the present application provides an electrical device comprising a battery pack according to any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0023] Figure 1 A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0024] Figure 2 for Figure 1 A schematic cross-sectional view of a cylindrical battery shown;

[0025] Figure 3 for Figure 2 A schematic diagram of the enlarged structure of the middle area A;

[0026] Figure 4 for Figure 1 A schematic cross-sectional view of a housing of a cylindrical battery;

[0027] Figure 5 A schematic cross-sectional view of a portion of the structure of a cylindrical battery provided in some other embodiments of the present application;

[0028] Figure 6 A schematic cross-sectional view of a portion of the structure of a cylindrical battery provided in some embodiments of the present application;

[0029] Figure 7 A schematic cross-sectional view of a portion of the structure of a cylindrical battery provided in some embodiments of the present application;

[0030] Figure 8 A schematic diagram of the structure of a battery pack provided in some embodiments of the present application;

[0031] Fig. 9 A schematic diagram of the structure of electrical equipment provided in some embodiments of the present application.

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

[0033] Cylindrical battery 1, electrode assembly 10, shell 20, side wall 21, side wall body 211, thinning portion 212, first end 212a, second end 212b, recess 213, first straight edge 2141, second straight edge 2142, virtual straight line 2143, transition arc edge 2144, third straight edge 2145, outer surface 21a, inner surface 21b, bottom wall 22, end cover 30, explosion-proof valve 40, electrode terminal 50, axis a, axial direction X;

[0034] Battery pack 100;

[0035] 1000 electrical equipment. 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 conjunction 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", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and 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 are omitted in different embodiments.

[0038] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0039] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0040] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "vertical" also includes not only the absolutely vertical situation, but also the roughly vertical situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered to be perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered to be parallel.

[0041] The cylindrical battery, battery pack and electrical equipment of the present application are described below in conjunction with the accompanying drawings.

[0042] The embodiment of the present application provides a cylindrical battery 1, which may be a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or other types of batteries.

[0043] Exemplarily, the cylindrical battery 1 may be a 21700 battery, a 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries.

[0044] In some embodiments, the cylindrical battery 1 is a secondary battery. After being discharged, the secondary battery can be charged to activate the active material and continue to be used.

[0045] In some embodiments, the cylindrical battery 1 includes an electrode assembly 10. The electrode assembly 10 includes a first electrode sheet and a second electrode sheet with opposite polarities. During the charge and discharge process of the cylindrical battery 1, active ions (such as lithium ions) are inserted and removed 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.

[0046] In some embodiments, the electrode assembly 10 further includes a diaphragm disposed between the first electrode sheet and the second electrode sheet, the diaphragm insulating the first electrode sheet from the second electrode sheet. The diaphragm is provided to reduce the risk of short circuit between the positive and negative electrode sheets, while allowing active ions to pass through.

[0047] In some embodiments, the first pole piece includes a first pole piece body and a first pole ear, and the second pole piece includes a second pole piece body and a second pole ear. The first pole piece body includes a first current collector and a first active material layer coated on the surface of the first current collector, and the first pole ear is connected to the first current collector. The second pole piece body includes a second current collector and a second active material layer coated on the surface of the second current collector, and the second pole ear is connected to the second current collector. One of the first pole ear and the second pole ear is a positive pole ear, and the other is a negative pole ear. Optionally, the first pole ear is integrally formed with the first current collector, and the second pole ear is integrally formed with the second current collector.

[0048] In some embodiments, the cylindrical battery 1 includes a housing 20, and the electrode assembly 10 is accommodated in the housing 20. The housing 20 defines a cylindrical space inside, and the shape of the electrode assembly 10 can match the shape of the space defined inside the housing 20.

[0049] In some embodiments, the housing 20 includes a side wall 21 disposed around the electrode assembly 10. The side wall 21 is generally in a cylindrical structure.

[0050] In some embodiments, the housing 20 may be a structure with an opening at one end. The housing 20 may be provided with a housing opening at one end along the axial direction X of the cylindrical battery 1, and the cylindrical space in the housing 20 may be opened to the outside through the housing opening.

[0051] In some embodiments, the housing 20 further includes a bottom wall 22, which is connected to the side wall 21. The bottom wall 22 may be connected to one end of the side wall 21 along the axial direction X of the cylindrical battery 1. Along the axial direction X of the cylindrical battery 1, the bottom wall 22 is disposed opposite to the housing opening.

[0052] The bottom wall 22 and the side wall 21 may be an integrally formed structure, or may be connected by welding, bonding, riveting or other suitable means.

[0053] In some embodiments, the cylindrical battery 1 includes an end cap 30, the bottom wall 22 and the end cap 30 are arranged along the axial direction X of the cylindrical battery 1, and the two ends of the side wall 21 are respectively connected to the bottom wall 22 and the end cap 30. The end cap 30 can cover the shell opening, thereby closing the cylindrical space in the shell 20.

[0054] The end cover 30 may be directly connected to the side wall 21 , or may be indirectly connected to the side wall 21 through other structures.

[0055] The material of the housing 20 and the end cover 30 can be steel, aluminum, composite metal or other conductive materials. The material of the housing 20 and the end cover 30 can be the same or different.

[0056] In some embodiments, the cylindrical battery 1 further includes an electrode terminal 50 , which can be used to be electrically connected to the electrode assembly 10 to output electrical energy from the cylindrical battery 1 or input electrical energy into the cylindrical battery 1 .

[0057] In some embodiments, the electrode terminal 50 may be disposed on the end cap 30 .

[0058] In some embodiments, the side wall 21 includes a side wall body 211 and a thinned portion 212 connected to the side wall body 211 , and the thinned portion 212 extends along the circumference of the cylindrical battery 1 .

[0059] The thinned portion 212 is weaker than the side wall body 211 . When the thinned portion 212 and the side wall body 211 are subjected to external forces of the same magnitude, the thinned portion 212 is more likely to break than the side wall body 211 .

[0060] Optionally, along the radial direction of the cylindrical battery 1 , the thickness of the thinned portion 212 may be smaller than the thickness of the side wall body 211 , so that the thinned portion 212 is more easily broken than the side wall body 211 .

[0061] In some embodiments, the side wall body 211 and the thinned portion 212 are integrally formed. The thinned portion 212 can be formed by providing structures such as notches and grooves on the side wall 21 .

[0062] In some embodiments, the thinned portion 212 may be a closed annular structure extending along the circumference of the cylindrical battery 1 , an arc-shaped structure extending along the circumference of the cylindrical battery 1 , or a spiral structure extending along the circumference of the cylindrical battery 1 .

[0063] In some embodiments, the bottom wall 22 and the end cover 30 are both connected to the side wall body 211, and neither the bottom wall 22 nor the end cover 30 is directly connected to the thinning portion 212. The thinning portion 212 can avoid the connection position between the bottom wall 22 and the side wall 21, and the connection position between the end cover 30 and the side wall 21, which is conducive to the formation of the thinning portion 212.

[0064] The side wall body 211 has two opposite ends arranged along the axial direction X of the cylindrical battery 1, and the two ends of the side wall body 211 are respectively connected to the bottom wall 22 and the end cover 30. Along the axial direction X of the cylindrical battery 1, the thinning portion 212 is spaced apart from the two ends of the side wall body 211, and the thinning portion 212 can be connected to the portion of the side wall body 211 located between the two ends thereof.

[0065] In the cylindrical battery 1 provided in the embodiment of the present application, the side wall 21 is provided with a relatively weak thinning portion 212. When the internal pressure of the cylindrical battery 1 is too high due to excessive charge and discharge, thermal runaway or other reasons, the thinning portion 212 can be promptly ruptured under the action of the air pressure inside the cylindrical battery 1, thereby releasing the pressure inside the cylindrical battery 1, which is beneficial to reducing the risk of explosion of the cylindrical battery 1 due to excessive internal air pressure and improving the safety performance and reliability of the cylindrical battery 1.

[0066] In some embodiments, reference Figure 3 , the minimum thickness of the thinned portion 212 is T1, the thickness of the side wall body 211 is T2, and 0.2≤T1 / T2≤0.4.

[0067] The side wall body 211 may be a structure of uniform thickness or a structure of unequal thickness. In some examples, the side wall body 211 is a structure of uniform thickness, and the thickness at any position of the side wall body 211 is T2. In other examples, the side wall body 211 may be a structure of unequal thickness, and the thickness T2 of the side wall body 211 may be the average thickness of the side wall body 211. For example, the thickness of any 50 positions of the side wall body 211 may be measured, and then the average value is taken.

[0068] The thinning portion 212 may be a structure of uniform thickness or a structure of unequal thickness. In some examples, the thinning portion 212 is a structure of uniform thickness, and the minimum thickness T1 of the thinning portion 212 is the thickness at any position of the thinning portion 212. In other examples, the thinning portion 212 is a structure of unequal thickness, for example, the thickness of the thinning portion 212 may be gradually set along the axial direction of the cylindrical battery 1, and T1 is the thickness at the thinnest position of the thinning portion 212.

[0069] Optionally, T1 / T2 may be 0.20, 0.22, 0.24, 0.26, 0.28, 0.30, 0.32, 0.34, 0.36, 0.38, 0.40 or any value therebetween.

[0070] The minimum thickness of the thinned portion 212 can, to some extent, characterize the ability of the thinned portion 212 to break. For example, when other structures are the same, the thinner the minimum thickness of the thinned portion 212, the easier it is for the portion of the thinned portion 212 with the smallest thickness to break.

[0071] In the embodiment of the present application, T1 / T2 is set to be greater than or equal to 0.2, so that the minimum thickness of the thinned portion 212 is not too thin relative to the side wall body 211, thereby reducing the risk of cracking and failure of the thinned portion 212 when the cylindrical battery 1 vibrates or is squeezed, thereby improving the structural stability of the cylindrical battery 1 and extending its service life.

[0072] In the embodiment of the present application, T1 / T2 is set to be greater than or equal to 0.4, so that when the cylindrical battery 1 thermally runs away, the thinned portion 212 can rupture in time and release the internal pressure of the cylindrical battery 1, thereby reducing the risk of explosion of the cylindrical battery 1 and improving the safety performance and reliability of the cylindrical battery 1.

[0073] In the embodiment of the present application, the ratio between the minimum thickness T1 of the thinned portion 212 and the thickness T2 of the side wall body 211 is set to 0.2-0.4, the shell 20 has a high strength, and the thinned portion 212 can be ruptured when the internal air pressure of the cylindrical battery 1 is too high to release the pressure in time, which is beneficial to balance the structural stability and safety performance of the cylindrical battery 1 and extend the service life of the cylindrical battery 1.

[0074] In some embodiments, 0.2 mm ≤ T2 ≤ 0.6 mm.

[0075] Optionally, the thickness T2 of the side wall body 211 may be 0.20 mm, 0.25 mm, 0.30 mm, 0.35 mm, 0.40 mm, 0.45 mm, 0.50 mm, 0.55 mm, 0.60 mm or any value therebetween.

[0076] In the embodiment of the present application, the thickness T2 of the side wall body 211 is set to be greater than or equal to 0.2 mm, which is beneficial to improving the mechanical strength of the side wall body 211 , thereby improving the overall strength of the side wall 21 .

[0077] In the embodiment of the present application, the thickness T2 of the side wall body 211 is set to be less than or equal to 0.6 mm, which can reduce the weight of the side wall body 211 and reduce the space occupied by the side wall 21 as a whole, which is beneficial to improving the energy density of the cylindrical battery 1.

[0078] In the embodiment of the present application, the thickness T2 of the side wall body 211 is set to 0.2 mm-0.6 mm, which is beneficial to balance the overall strength of the side wall 21 and the energy density of the cylindrical battery 1.

[0079] In some embodiments, the material of the side wall 21 may be steel. The thickness T2 of the side wall body 211 may be 0.2 mm-0.4 mm, and the minimum thickness T1 of the thinned portion 212 may be 0.04 mm-0.08 mm.

[0080] In some embodiments, the material of the side wall 21 may be aluminum. The thickness T2 of the side wall body 211 may be 0.4 mm-0.6 mm, and the minimum thickness T1 of the thinned portion 212 may be 0.08 mm-0.16 mm.

[0081] In some embodiments, along the circumference of the cylindrical battery 1, the thinned portion 212 has a first end 212a and a second end 212b opposite to each other, and the first end 212a and the second end 212b are spaced apart in the circumference of the cylindrical battery 1. In other words, the thinned portion 212 surrounds the electrode assembly 10 for less than one circle. Along the circumference of the cylindrical battery 1, a portion of the side wall body 211 is connected between the first end 212a and the second end 212b of the thinned portion 212.

[0082] Optionally, the thinned portion 212 may be an arc-shaped structure extending along the circumference of the cylindrical battery 1 .

[0083] Compared with the thinning portion 212, the side wall body 211 is thicker, and the side wall body 211 is not easy to break when the cylindrical battery 1 is thermally runaway. After the thinning portion 212 breaks to form a fracture, the two parts of the side wall 21 located on both sides of the fracture can be connected through the part of the side wall body 211 located between the first end 212a and the second end 212b, reducing the risk of the side wall 21 breaking into two completely separated parts.

[0084] In some embodiments, reference Figure 4 The thinning portion 212 is in an arc shape. The center angle γ corresponding to the thinning portion 212 is 240°-330°. In some optional embodiments, the center angle γ corresponding to the thinning portion 212 may be 270°-300°.

[0085] Optionally, the central angle γ corresponding to the thinned portion 212 may be 240°, 250°, 260°, 270°, 280°, 290°, 300°, 310°, 320°, 330° or any angle value therebetween.

[0086] In the embodiment of the present application, the central angle γ corresponding to the thinning portion 212 is set to be greater than or equal to 240°, and the length of the thinning portion 212 extending along the circumferential direction of the cylindrical battery 1 does not account for too small a proportion of the entire circumference of the circle where the thinning portion 212 is located, so that the thinning portion 212 can be broken in time.

[0087] In the embodiment of the present application, the central angle γ corresponding to the thinning portion 212 is set to be less than or equal to 330°, and the portion of the side wall body 211 between the first end 212a and the second end 212b is not too small, which is beneficial to reducing the risk of the portion being pulled off when the thinning portion 212 breaks, causing the side wall 21 to explode into two completely separated parts, thereby reducing the safety hazards of the cylindrical battery 1.

[0088] The embodiment of the present application sets the central angle γ corresponding to the thinning portion 212 to 240°-330°, which is beneficial to the rupture of the thinning portion 212 and reduces the possibility of the side wall 21 bursting into two completely separated parts, thereby reducing safety risks.

[0089] In some embodiments, the cylindrical battery 1 includes an explosion-proof valve 40 disposed on the end cover 30 .

[0090] The explosion-proof valve 40 may be connected to the end cover 30 by welding, riveting or other suitable methods.

[0091] When the gas pressure inside the cylindrical battery 1 exceeds the upper limit that the explosion-proof valve 40 can withstand, the gas inside the cylindrical battery 1 can cause the explosion-proof valve 40 to flip and explode away from the electrode assembly 10, thereby achieving the purpose of pressure relief, which is beneficial to reducing the risk of explosion of the cylindrical battery 1 due to excessive internal gas pressure and improving the safety performance of the cylindrical battery 1.

[0092] In some embodiments, along the axial direction X of the cylindrical battery 1 , the distance between the thinned portion 212 and the bottom wall 22 is greater than the distance between the thinned portion 212 and the end cover 30 .

[0093] Along the axial direction X of the cylindrical battery 1 , the thinned portion 212 is disposed closer to the bottom wall 22 .

[0094] The explosion-proof valve 40 and the thinning portion 212 respectively form two pressure relief structures of the cylindrical battery 1. The explosion-proof valve 40 is provided on the end cover 30. When the internal pressure of the cylindrical battery 1 is too high, the gas inside the cylindrical battery 1 can be discharged through the flipping and explosion of the explosion-proof valve 40; the thinning portion 212 is closer to the bottom wall 22. When the internal pressure of the cylindrical battery 1 continues to increase, the gas inside the cylindrical battery 1 can also be discharged through the rupture of the thinning portion 212. Under different internal pressures, the cylindrical battery 1 can release pressure in different directions through the two pressure relief structures, which is conducive to improving the pressure relief efficiency and further improving the safety performance and reliability of the cylindrical battery 1.

[0095] In some embodiments, along the axial direction X of the cylindrical battery 1, the distance between the thinned portion 212 and the bottom wall 22 is 3 mm-15 mm. In some optional embodiments, the distance between the thinned portion 212 and the bottom wall 22 may be 4 mm-7 mm.

[0096] Optionally, the spacing between the thinned portion 212 and the bottom wall 22 may be 3 mm, 4 mm, 5 mm, 6 mm, 7 mm, 8 mm, 9 mm, 10 mm, 11 mm, 12 mm, 13 mm, 14 mm, 15 mm or any value therebetween.

[0097] In the embodiment of the present application, the spacing between the thinning portion 212 and the bottom wall 22 is set to be greater than or equal to 3 mm, and the connection position between the thinning portion 212 and the bottom wall 22 and the side wall 21 has an appropriate distance, which can reduce the stress on the thinning portion 212 from the bottom wall 22, which is conducive to the timely rupture of the thinning portion 212 when the cylindrical battery 1 is thermally runaway.

[0098] In the embodiment of the present application, the distance between the thinning portion 212 and the bottom wall 22 is set to be less than or equal to 15 mm, so that the distance between the thinning portion 212 and the bottom wall 22 is not too large. When the pressure inside the cylindrical battery 1 is too high, the thinning portion 212 does not require too much turning space when it ruptures, which is beneficial to improving the pressure relief effect.

[0099] In some embodiments, along the axial direction X of the cylindrical battery 1 , the size of the side wall 21 is 40 mm-210 mm.

[0100] Optionally, the dimension of the side wall 21 in the axial direction X of the cylindrical battery 1 can be 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm or any value therebetween.

[0101] The size of the side wall 21 in the axial direction X of the cylindrical battery 1 directly affects the size of the accommodation space in the shell 20, thereby affecting the size of the electrode assembly 10 that can be accommodated in the shell 20, and further affecting the capacity of the cylindrical battery 1. The size of the side wall 21 in the axial direction X of the cylindrical battery 1 will also affect the gas flow path inside the cylindrical battery 1, thereby affecting the exhaust efficiency of the cylindrical battery 1.

[0102] In the embodiment of the present application, the dimension of the side wall 21 in the axial direction X of the cylindrical battery 1 is set to be greater than or equal to 40 mm, which is beneficial to increase the size of the electrode assembly 10 that can be accommodated in the shell 20 and improve the capacity of the cylindrical battery 1.

[0103] In the embodiment of the present application, the dimension of the side wall 21 in the axial direction X of the cylindrical battery 1 is set to be less than or equal to 210 mm, which can shorten the gas exhaust path inside the cylindrical battery 1, reduce the difficulty of gas exhaust, and improve the exhaust efficiency.

[0104] In the embodiment of the present application, the dimension of the side wall 21 in the axial direction X of the cylindrical battery 1 is set to 40 mm-210 mm, which is beneficial to balance the capacity and exhaust efficiency of the cylindrical battery 1.

[0105] In some embodiments, the bursting pressure of the thinned portion 212 is greater than the bursting pressure of the explosion-proof valve 40. In other words, the maximum pressure value that the thinned portion 212 withstands when it bursts is greater than the maximum pressure value that the explosion-proof valve 40 withstands when it bursts.

[0106] When the pressure in the cylindrical battery 1 is relatively high but has not reached a certain level, the explosion-proof valve 40 may explode before the thinned portion 212. The cylindrical battery 1 is depressurized by flipping and exploding the explosion-proof valve 40 first, which can reduce the possibility of rupture of the thinned portion 212 and reduce the electrolyte leakage, short circuit and other phenomena that may be caused by the breakage of the shell 20.

[0107] In some embodiments, the venting passage of the explosion-proof valve 40 is blocked by the electrode assembly 10, or by electrolyte, electrode and diaphragm residues, etc. When the pressure in the cylindrical battery 1 continues to increase, the thinned portion 212 can explode to exhaust gas, which is beneficial to improve the pressure relief efficiency.

[0108] In some embodiments, the bursting pressure of the thinned portion 212 may be 2.7 MPa-3.5 MPa.

[0109] In some embodiments, the explosion pressure of the explosion-proof valve 40 may be 1.6 MPa-3.5 MPa.

[0110] In some embodiments, the bursting pressure of the thinned portion 212 can be measured in the following manner: prepare a shell 20 with a thinned portion 212 on the side wall 21; prepare an end cover 30; drill a circular hole on the end cover 30, and the diameter of the circular hole can be 4 mm; after assembling the shell 20 and the end cover 30, a cylindrical battery is obtained; use a clamp to fix the obtained cylindrical battery about 10 mm close to the end cover 30; open the inflation valve of the air pressure bursting tester (model SC-QYBP-10, Xiamen Sanchuang Keyi Testing Equipment Co., Ltd.), and inflate the interior of the shell 20 through the circular hole of the end cover 30 at a speed of 0.1 MPa / s until the thinned portion 212 of the side wall 21 bursts.

[0111] In some embodiments, the bursting pressure of the explosion-proof valve 40 can be measured in the following manner: prepare a shell 20 with a thinned portion 212 on the side wall 21; prepare an end cover 30 with an explosion-proof valve 40; drill a circular hole on the end cover 30, and the diameter of the circular hole can be 4 mm; after assembling the shell 20 and the end cover 30, a cylindrical battery is obtained; use a clamp to fix the obtained cylindrical battery about 10 mm close to the end cover 30; open the inflation valve of the air pressure burst testing machine (model SC-QYBP-10, Xiamen Sanchuang Keyi Testing Equipment Co., Ltd.), and inflate the inside of the shell 20 through the circular hole of the end cover 30 at a speed of 0.1 MPa / s until the explosion-proof valve 40 explodes.

[0112] In some embodiments, reference Figure 3 and Figure 5 The outer surface 21 a of the side wall 21 is recessed to form a thinned portion 212 .

[0113] Along the radial direction of the cylindrical battery 1, the outer surface 21a of the side wall 21 may be recessed toward the direction close to the axis a of the cylindrical battery 1 to form a thinning portion 212. A concave portion 213 is formed on the side of the side wall 21 facing away from the electrode assembly 10, and along the radial direction of the cylindrical battery 1, the concave portion 213 corresponds to the thinning portion 212.

[0114] A recess may or may not be provided at a position corresponding to the thinned portion 212 on the inner side of the side wall 21 facing the electrode assembly 10 .

[0115] In other embodiments, reference Figure 6 The inner surface 21 b of the side wall 21 is recessed to form a thinned portion 212 .

[0116] In the radial direction of the cylindrical battery 1, the inner surface 21b of the side wall 21 may be recessed in a direction away from the axis a of the cylindrical battery 1 to form a thinning portion 212. A concave portion 213 is formed on the side of the side wall 21 facing the electrode assembly 10, and in the radial direction of the cylindrical battery 1, the concave portion 213 corresponds to the thinning portion 212.

[0117] A recess may or may not be provided at a position of the side wall 21 at the outer side facing away from the electrode assembly 10 and corresponding to the thinned portion 212 .

[0118] In some other embodiments, reference Figure 7 The outer surface 21 a of the side wall 21 and the inner surface 21 b of the side wall 21 are recessed to form a thinned portion 212 .

[0119] Along the radial direction of the cylindrical battery 1 , the outer surface 21 a of the side wall 21 may be recessed toward the axis a of the cylindrical battery 1 , and the inner surface 21 b of the side wall 21 may be recessed toward the axis a of the cylindrical battery 1 to form a thinned portion 212 .

[0120] A concave portion 213 is formed on the side of the side wall 21 facing the electrode assembly 10 and on the side of the side wall 21 facing away from the electrode assembly 10 . Along the radial direction of the cylindrical battery 1 , the concave portion 213 corresponds to the thinned portion 212 .

[0121] In the embodiment of the present application, the thinning portion 212 is formed by a surface depression of the side wall 21 . The thinning portion 212 can be formed by stamping, cutting or other suitable methods. The forming process is simple, which is conducive to improving the production efficiency of the cylindrical battery 1 .

[0122] In some embodiments, reference Figures 3 to 7 The side wall 21 forms a thinned portion 212 by providing a recess 213 , and the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 is a triangle or a trapezoid.

[0123] In some examples, there may be one recess 213 , which may be formed on a side of the side wall 21 facing the electrode assembly 10 , or on a side of the side wall 21 facing away from the electrode assembly 10 .

[0124] In some examples, there may be two recesses 213 , which are respectively formed on a side of the side wall 21 facing the electrode assembly 10 and a side of the side wall 21 facing away from the electrode assembly 10 , and the two recesses 213 are arranged opposite to each other along the radial direction of the cylindrical battery 1 .

[0125] The cross section of the recess 213 being triangular or trapezoidal means that the cross section of the recess 213 is triangular or trapezoidal as a whole, but is not required to be a triangle or trapezoid in a strict sense.

[0126] In some embodiments, the size of the recess 213 in the axial direction X of the cylindrical battery 1 gradually decreases from the outside to the inside along the radial direction of the cylindrical battery 1. Exemplarily, the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 may be a triangle, wherein one of the angles of the triangle is closest to the axis a of the cylindrical battery 1. Exemplarily, the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 may be a trapezoid, wherein the upper base of the trapezoid is closer to the axis a than the lower base.

[0127] In the embodiment of the present application, by providing the concave portion 213 with a triangular or trapezoidal cross-section, the thickness of the thinned portion 212 along the radial direction of the cylindrical battery 1 can be gradually changed. For example, along the axial direction X of the cylindrical battery 1, the thickness of the thinned portion 212 first gradually decreases and then gradually increases. As a result, it is more conducive to the thinned portion 212 to rupture at the part with the smallest thickness, thereby releasing the pressure inside the cylindrical battery 1.

[0128] In some embodiments, reference Figure 3 and Figure 5 The side wall 21 forms a thinned portion 212 by providing a recess 213. The cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 includes a first straight edge 2141 and a second straight edge 2142, and the first straight edge 2141 and the second straight edge 2142 are respectively located on both sides of a virtual straight line 2143, and the virtual straight line 2143 is perpendicular to the axis a and intersects the axis a.

[0129] The virtual straight line 2143 may extend along the radial direction of the cylindrical battery 1 , and the first straight edge 2141 and the second straight edge 2142 are respectively located on both sides of the virtual straight line 2143 in the axial direction X of the cylindrical battery 1 .

[0130] The virtual straight line 2143 may be any straight line located between the first straight side 2141 and the second straight side 2142 in the axial direction X of the cylindrical battery 1. The first straight side 2141 may intersect the virtual straight line 2143, or may be spaced apart from the virtual straight line 2143. The second straight side 2142 may intersect the virtual straight line 2143, or may be spaced apart from the virtual straight line 2143.

[0131] In some examples, the first straight side 2141 and the second straight side 2142 intersect at a virtual straight line 2143, and the intersection point between the first straight side 2141 and the virtual straight line 2143 coincides with the intersection point between the second straight side 2142 and the virtual straight line 2143. In these examples, the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 may be a standard triangle.

[0132] In other examples, refer to Figure 3 , at least one of the first straight side 2141 and the second straight side 2142 is spaced from the virtual straight line 2143, and the first straight side 2141 and the second straight side 2142 are connected by a transition arc side 2144. In these examples, the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 is substantially triangular.

[0133] In some other examples, reference Figure 5, at least one of the first straight side 2141 and the second straight side 2142 is spaced from the virtual straight line 2143, and the first straight side 2141 and the second straight side 2142 are connected by a third straight side 2145 parallel to the axis a. In these examples, the cross section of the recess 213 coplanar with the axis a of the cylindrical battery 1 may be trapezoidal.

[0134] In some embodiments, the angle between the first straight edge 2141 and the virtual straight line 2143 is α, the angle between the second straight edge 2142 and the virtual straight line 2143 is β, and α≤β.

[0135] The angle α between the first straight side 2141 and the virtual straight line 2143 may be the angle formed by the intersection of the first straight side 2141 and the virtual straight line 2143 , or may be the angle formed by the intersection of the extended side of the first straight side 2141 and the virtual straight line 2143 .

[0136] The angle β between the second straight side 2142 and the virtual straight line 2143 may be the angle formed by the intersection of the second straight side 2142 and the virtual straight line 2143 , or may be the angle formed by the intersection of the extended side of the second straight side 2142 and the virtual straight line 2143 .

[0137] In the axial direction X of the cylindrical battery 1 , the first straight edge 2141 may be closer to the bottom wall 22 than the second straight edge 2142 , and the first straight edge 2141 may be farther away from the bottom wall 22 than the second straight edge 2142 .

[0138] The embodiment of the present application sets the angle between the first straight edge 2141 and the virtual straight line 2143 and the angle between the second straight edge 2142 and the virtual straight line 2143 to be different, which is beneficial to reducing the deviation of the bursting pressure of the thinning portion 212, improving the consistency of the bursting pressure of the thinning portion 212, reducing the risk of accidental bursting of the thinning portion 212 under a smaller pressure less than its set bursting pressure value, and reducing the risk of the thinning portion 212 not bursting under a larger pressure greater than its set bursting pressure value, and is also beneficial to improving the directional consistency of the bursting of the thinning portion 212, thereby improving the blasting stability of the thinning portion 212.

[0139] In some embodiments, 10°≤β-α≤40°.

[0140] Optionally, β-α may be 10°, 15°, 20°, 25°, 30°, 35°, 40° or any value therebetween.

[0141] In the embodiment of the present application, β-α is set to be greater than or equal to 10°, which is beneficial to reducing the deviation of the bursting pressure of the thinned portion 212 and improving the bursting stability and directional consistency of the thinned portion 212.

[0142] In the embodiment of the present application, β-α is set to be less than or equal to 40°, so that the portion of the thinned portion 212 corresponding to the second straight edge 2142 is not thinned too much, which can reduce the stress influence from the side wall body 211 on the portion with the smallest thickness of the thinned portion 212, and is conducive to the timely explosion of the thinned portion 212 when the cylindrical battery 1 has thermal runaway.

[0143] In the embodiment of the present application, β-α is set to 10°-40°, which is beneficial to balancing the blasting stability of the thinned portion 212 and the blasting directional consistency of the thinned portion 212 .

[0144] In some embodiments, 60°≤α+β≤150°.

[0145] Optionally, α+β may be 60°, 70°, 80°, 90°, 100°, 110°, 120°, 130°, 140°, 150° or any value therebetween.

[0146] In the embodiment of the present application, α+β is set to be greater than or equal to 60°, and the dimension of the thinned portion 212 along the axial direction X of the cylindrical battery 1 is not too small, which is conducive to the thinned portion 212 turning over and deforming outward under the pressure inside the cylindrical battery 1, thereby facilitating the smooth explosion of the thinned portion 212.

[0147] In the embodiment of the present application, α+β is set to be less than or equal to 150°, and the dimension of the thinned portion 212 along the axial direction X of the cylindrical battery 1 is not too large, which is beneficial to reducing the impact on the overall structural strength of the side wall 21 .

[0148] In the embodiment of the present application, α+β is set to 60°-150°, which is beneficial to balance the blasting smoothness of the thinning portion 212 and the overall structural strength of the side wall 21 .

[0149] In some embodiments, 20°≤α≤60°.

[0150] α is the smaller angle between the first straight edge 2141 and the second straight edge 2142 and the virtual straight line 2143 .

[0151] Optionally, α may be 20°, 25°, 30°, 35°, 40°, 45°, 50°, 55°, 60° or any value therebetween.

[0152] The embodiment of the present application sets α to be greater than or equal to 20°, which is beneficial to reducing the stress influence from the side wall body 211 on the portion with the smallest thickness of the thinning portion 212, thereby facilitating the smooth blasting of the thinning portion 212.

[0153] In the embodiment of the present application, α is set to be less than or equal to 60°, so that the dimension of the thinned portion 212 along the axial direction X of the cylindrical battery 1 is not too large, which is beneficial to reducing the impact on the overall structural strength of the side wall 21 .

[0154] In the embodiment of the present application, α is set to 20°-60°, which is beneficial to balance the blasting smoothness of the thinning portion 212 and the overall structural strength of the side wall 21 .

[0155] In some embodiments, the bottom wall 22 and the electrode assembly 10 are disposed along the axial direction X of the cylindrical battery 1 . Along the axial direction X of the cylindrical battery 1 , the second straight edge 2142 is closer to the bottom wall 22 than the first straight edge 2141 .

[0156] The thinned portion 212 is disposed closer to the bottom wall 22 as a whole, and the minimum distance between the second straight edge 2142 and the bottom wall 22 is smaller than the minimum distance between the first straight edge 2141 and the end cover 30. The second straight edge 2142 is subjected to greater stress from the connection position between the side wall 21 and the bottom wall 22.

[0157] To this end, the embodiment of the present application makes the angle between the second straight edge 2142 closer to the bottom wall 22 and the virtual straight line 2143 larger, which can reduce the overall thickness of the portion of the thinning portion 212 corresponding to the second straight edge 2142, so as to be more conducive to overcoming the stress and deforming outward, thereby improving the blasting orientation consistency of the thinning portion 212.

[0158] According to the second aspect of the present application, referring to Figure 8 The embodiment of the present application also provides a battery pack 100, and the battery pack 100 includes a cylindrical battery 1 provided according to any embodiment of the present application.

[0159] In some embodiments, the battery pack 100 further includes a plurality of bus bars. The bus bars connect the cylindrical batteries 1. At least two cylindrical batteries 1 may be connected in series or in parallel via the bus bars.

[0160] According to the third aspect of the present application, referring to Fig. 9 The embodiment of the present application further provides an electric device 1000, and the electric device 1000 includes the battery pack 100 provided in any embodiment of the present application. The battery pack 100 can provide electric energy for the operation of the electric device 1000.

[0161] The electric device 1000 of the embodiment of the present application may be a portable device, an electric toy, a drone, an electric tool, an energy storage system, etc. The electric tool includes a metal cutting electric tool, a cleaning tool, etc., for example, an electric drill, an electric wrench, a vacuum cleaner, a sweeping robot, etc. The embodiment of the present application does not impose any special restrictions on the above-mentioned electric devices.

[0162] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cylindrical battery, characterized in that: include: Electrode assembly; A shell, wherein the electrode assembly is accommodated in the shell, the shell includes a side wall arranged around the electrode assembly, the side wall includes a side wall body and a thinning portion connected to the side wall body, the thinning portion extends along the circumference of the cylindrical battery, the minimum thickness of the thinning portion is T1, the thickness of the side wall body is T2, 0.2≤T1 / T2≤0.

4.

2. The cylindrical battery according to claim 1, characterized in that: 0.2mm≤T2≤0.6mm.

3. The cylindrical battery according to claim 1 or 2, characterized in that: The thinned portion has a first end and a second end opposite to each other along the circumferential direction, and the first end and the second end are spaced apart from each other in the circumferential direction.

4. The cylindrical battery according to any one of claims 1 to 3, characterized in that: The thinned portion is in an arc shape; The central angle corresponding to the thinned portion is 240°-330°, and can be optionally 270°-300°.

5. The cylindrical battery according to any one of claims 1 to 4, characterized in that: The housing includes a bottom wall, the cylindrical battery includes an end cover and an explosion-proof valve arranged on the end cover, the bottom wall and the end cover are arranged along the axial direction of the cylindrical battery, and the two ends of the side wall are respectively connected to the bottom wall and the end cover; Along the axial direction, the distance between the thinned portion and the bottom wall is greater than the distance between the thinned portion and the end cover.

6. The cylindrical battery according to claim 5, characterized in that: Along the axial direction, the spacing between the thinned portion and the bottom wall is 3 mm-15 mm, and can be optionally 4 mm-7 mm.

7. The cylindrical battery according to claim 5 or 6, characterized in that: Along the axial direction, the size of the side wall is 40mm-210mm.

8. The cylindrical battery according to any one of claims 5 to 7, characterized in that: The bursting pressure of the thinned portion is greater than the bursting pressure of the explosion-proof valve.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: The outer surface of the side wall is recessed to form the thinned portion; and / or the inner surface of the side wall is recessed to form the thinned portion.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: The side wall is provided with a concave portion to form the thinning portion, and the cross section of the concave portion coplanar with the axis of the cylindrical battery is a triangle or a trapezoid.

11. The cylindrical battery according to any one of claims 1 to 10, characterized in that: The side wall is provided with a recessed portion to form the thinned portion; The cross section of the concave portion coplanar with the axis of the cylindrical battery includes a first straight side and a second straight side, wherein the first straight side and the second straight side are respectively located on both sides of a virtual straight line, and the virtual straight line is perpendicular to the axis and intersects the axis; The included angle between the first straight side and the virtual straight line is α, the included angle between the second straight side and the virtual straight line is β, and α≤β.

12. The cylindrical battery according to claim 11, characterized in that: 10°≤β-α≤40°。 13. The cylindrical battery according to claim 11 or 12, characterized in that: 60°≤α+β≤150°。 14. The cylindrical battery according to any one of claims 11 to 13, characterized in that: 20°≤α≤60°。 15. The cylindrical battery according to any one of claims 11 to 14, characterized in that: The shell includes a bottom wall, the bottom wall is connected to the side wall, and the bottom wall and the electrode assembly are arranged along the axial direction of the cylindrical battery; Along the axial direction, the distance between the thinned portion and the bottom wall is 3 mm-15 mm, and the second straight edge is closer to the bottom wall than the first straight edge.

16. A battery pack, characterized in that: Comprising a cylindrical battery according to any one of claims 1-15.

17. An electrical equipment, characterized in that: Comprising a battery pack according to claim 16.

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