Cylindrical battery, battery pack and power utilization device

Abstract

The invention provides a cylindrical battery, a battery pack and an electric device, and relates to the technical field of energy storage. The cylindrical battery provided by the invention comprises a shell, an electrode assembly and a top cover, the top cover comprises a substrate part, an end face part and a plurality of connecting parts. On one side, far away from the center of the end face part, of the cylindrical battery in the radial direction, the connecting part is provided with a first end and a second end, a connecting line between the first end and the center of the end face part is a first connecting line, a connecting line between the second end and the center of the end face part is a second connecting line, the first connecting line and the second connecting line intersect to form first included angles, the sum of the multiple first included angles is A, 120 degrees < = A < = 210 degrees. The structural strength of the top cover is enhanced by increasing the connecting range of the connecting part, the end face part and the base plate part, the degree that the overturning distance of the anti-explosion piece is increased due to deformation of the top cover is reduced, the power-off and pressure relief stability of the cylindrical battery is improved, and the safety performance of the cylindrical battery is improved.

Description

Technical Field

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

[0002] The manufacturing process of cylindrical batteries is mature, the product quality is stable, and the demand is increasing. The top cover is an important structure of cylindrical batteries and has many functions. On the one hand, the top cover serves as the positive or negative electrode of the battery to output electrical energy to the outside. On the other hand, the top cover forms a flipping space for the explosion-proof plate. When the cylindrical battery is working abnormally, such as an external short circuit, the internal air pressure of the battery increases, and the explosion-proof plate flips and explodes under high pressure, causing the cylindrical battery to lose power and release pressure.

[0003] In the prior art, the top cover may be deformed when the explosion-proof plate is flipped, resulting in an increase in the flipping distance of the explosion-proof plate, reducing the stability of power failure and pressure relief of the cylindrical battery, and reducing the service life of the cylindrical battery. Summary of the invention

[0004] The purpose of the embodiments of the present application is to provide a cylindrical battery, a battery pack and an electrical device, which are conducive to enhancing the structural strength of the top cover of the cylindrical battery and improving the stability of power failure and pressure relief of the cylindrical battery. The specific technical solution is as follows:

[0005] The first aspect of the present application provides a cylindrical battery, comprising: a shell; an electrode assembly, arranged in the shell; a top cover, insulated and connected to the shell, and arranged along the axial direction of the cylindrical battery with the electrode assembly; the top cover comprises a substrate portion, an end face portion and a plurality of connecting portions; the substrate portion and the shell are insulated and connected, the plurality of connecting portions are arranged at intervals and surround the end face portion, and the plurality of connecting portions connect the end face portion and the substrate portion; when viewed along the axial direction, the connecting portion extends around the center of the end face portion, and the connecting portion has a first end and a second end on a side away from the center of the end face portion in the radial direction of the cylindrical battery, the line connecting the first end and the center of the end face portion is the first line, the line connecting the second end and the center of the end face portion is the second line, the first line and the second line intersect to form a first angle α, the sum of the plurality of first angles α is A, 120°≤A≤210°.

[0006] By increasing the sum A of the multiple first angles, the connection range between the connecting portion and the end surface portion and the base plate portion is increased, which is beneficial to enhancing the structural strength of the top cover, improving the deformation resistance of the top cover after being driven by the internal components of the shell (such as the overturning of the explosion-proof plate), reducing the degree to which the overturning distance of the explosion-proof plate caused by the deformation of the top cover increases, improving the stability of power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0007] In one or more embodiments, 150°≤A≤210°. By further increasing the connection range between the connecting portion and the end surface portion and the substrate portion, it is beneficial to further enhance the structural strength of the top cover, improve the deformation resistance of the top cover, improve the stability of power-off and pressure relief of the cylindrical battery, and improve the safety performance of the cylindrical battery.

[0008] In one or more embodiments, 180°≤A≤210°. By further increasing the connection range between the connection part and the end face part and the substrate part, A≥180° further enhances the structural strength of the top cover, improves the deformation resistance of the top cover, improves the stability of power-off and pressure relief of the cylindrical battery, and improves the safety performance of the cylindrical battery. A≤210°, by making the connection range between the connection part and the end face part and the substrate part within a certain degree, it is helpful to reduce the obstruction of the connection part to the pressure relief and exhaust of the cylindrical battery from the inside to the outside, reduce the pressure relief time of the cylindrical battery, and improve the safety performance of the cylindrical battery.

[0009] In one or more embodiments, when observed along the axial direction, the connecting portion includes a first supporting wall and a second supporting wall that are interconnected, and the second supporting wall protrudes radially from an end surface of the first supporting wall that is away from the center of the end surface portion, which is beneficial to improving the structural strength of the connecting portion, improving the deformation resistance of the top cover, improving the stability of power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0010] In one or more embodiments, when viewed along the axial direction, the second support wall has a third end and a fourth end on a side radially away from the center of the end face portion; a line connecting the third end and the center of the end face portion is a third line, a line connecting the fourth end and the center of the end face portion is a fourth line, and the third line and the fourth line intersect to form a second angle β, 1 / 4≤β / α≤1 / 2. In the above β / α ratio range, it is beneficial to improve the structural strength of the connection portion, thereby improving the deformation resistance of the top cover.

[0011] In one or more embodiments, when viewed along the axial direction, the distance that the second support wall protrudes from the end surface of the first support wall facing away from the center of the end surface portion in the radial direction is L1; the thickness of the end surface portion is L2; ​​1≤L1 / L2≤2. In the above L1 / L2 ratio range, the second support wall protrudes from the end surface of the first support wall facing away from the center of the end surface portion in the radial direction by a certain distance, which is beneficial to improving the structural strength of the connection portion, thereby improving the deformation resistance of the top cover.

[0012] In one or more embodiments, 0.6 mm ≤ L2 ≤ 1 mm. Setting the thickness of the end surface portion within the above range is beneficial to improving the deformation resistance of the top cover.

[0013] In one or more embodiments, the radius of the circumscribed circle of the end face is r, the radius of the top cover is R, and 1 / 3≤r / R≤2 / 3. In the above r / R ratio range, it is beneficial to provide a larger turning space for the explosion-proof plate inside the top cover, and provide a smooth pressure relief channel for the internal pressure relief of the cylindrical battery, thereby improving the stability of power-off and pressure relief of the cylindrical battery and improving the safety performance of the cylindrical battery.

[0014] In one or more embodiments, 15 mm ≤ R ≤ 50 mm. In the above range of R, the diameter of the cylindrical battery is larger, which is beneficial to improving the capacity of the cylindrical battery, making the cylindrical battery suitable for high-power and long-endurance application scenarios.

[0015] In one or more embodiments, it also includes an explosion-proof plate, which is connected to the top cover and the electrode assembly. Along the axial direction of the cylindrical battery, a portion of the explosion-proof plate is arranged between the end surface and the electrode assembly, and the portion is configured to flip when the air pressure in the cylindrical battery reaches a first threshold value, disconnected from the electrode assembly, and the explosion-proof plate explodes when the air pressure in the cylindrical battery reaches a second threshold value, so that the gas inside and outside the shell of the cylindrical battery is connected. When the explosion-proof plate is disconnected from the electrode assembly, the internal current path of the cylindrical battery is cut off, which is conducive to reducing the loss caused by the continuous short circuit of the cylindrical battery. When the explosion-proof plate explodes, the high-pressure gas in the shell of the cylindrical battery is discharged to the outside and the pressure is relieved, which is conducive to improving the safety of the cylindrical battery.

[0016] In one or more embodiments, the number of the connecting parts is three or four. The above number of connecting parts is used to facilitate production and processing, thereby reducing the production cost of the cylindrical battery.

[0017] In one or more embodiments, the material of the top cover includes nickel-plated carbon steel. The above material is not easy to rust, which is conducive to improving the durability of the top cover. In addition, the nickel-plated carbon steel has high strength, which is conducive to enhancing the structural strength of the top cover, reducing the deformation of the top cover after being impacted by the internal pressure of the shell, reducing the degree of increase in the flipping distance of the explosion-proof plate caused by the deformation of the top cover, improving the stability of the power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0018] A second aspect of the present application provides a battery pack comprising a cylindrical battery in any of the above embodiments.

[0019] A third aspect of the present application provides an electrical device comprising a cylindrical battery or a battery pack according to any of the above embodiments.

[0020] The cylindrical battery, battery pack and electrical device provided in the embodiments of the present application, the cylindrical battery includes a shell, an electrode assembly and a top cover. The top cover includes a substrate portion, an end face portion and a plurality of connecting portions. On the side of the cylindrical battery away from the center of the end face portion in the radial direction, the connecting portion has a first end and a second end, the line connecting the first end and the center of the end face portion is the first line, the line connecting the second end and the center of the end face portion is the second line, the first line and the second line intersect to form a first angle, the sum of the plurality of first angles is A, 120°≤A≤210°. By increasing the connection range between the connecting portion and the end face portion and the substrate portion, it is beneficial to enhance the structural strength of the top cover, improve the deformation resistance of the top cover, reduce the degree of increase in the flipping distance of the explosion-proof plate due to deformation of the top cover, improve the stability of power-off and pressure relief of the cylindrical battery, and improve the safety performance of the cylindrical battery.

[0021] Of course, any product implementing the present application does not necessarily need to achieve all of the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application, and a person skilled in the art can also obtain other drawings based on these drawings.

[0023] Figure 1 A schematic diagram of the structure of a cylindrical battery according to an embodiment of the present application;

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

[0025] Figure 3 for Figure 1 A schematic diagram of the top structure of the cylindrical battery shown;

[0026] Figure 4 A schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0027] Figure 5 A schematic diagram of the structure of a first electrical device provided in an embodiment of the present application;

[0028] Figure 6 A schematic diagram of the structure of a second electrical device provided in an embodiment of the present application;

[0029] Figure 7 A schematic diagram of a partial cross-sectional structure of a cylindrical battery before an explosion test according to an embodiment of the present application;

[0030] Figure 8This is a schematic diagram of a partial cross-sectional structure of a cylindrical battery after an explosion test according to an embodiment of the present application.

[0031] The reference numerals are as follows:

[0032] Shell 100, electrode assembly 200, top cover 300, substrate portion 310, substrate portion edge top 310a, end face portion 320, end face portion edge lower surface 320a, center 321, connection portion 330, first end 330a, second end 330b, third end 330c, fourth end 330d, first connecting line 331, second connecting line 332, first supporting wall 333, second supporting wall 334, third connecting line 335, fourth connecting line 336, pressure relief hole 340, explosion-proof disk 400, and a portion 410 of the explosion-proof disk;

[0033] Cylindrical battery 10, battery pack 20, power-consuming device 30;

[0034] Radial X, axial Y. DETAILED DESCRIPTION

[0035] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions 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. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field based on the present application belong to the scope of protection of the present application.

[0036] In this application, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like 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 mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in this application can be understood according to the specific circumstances. The term "and / or" used herein includes any and all combinations of one or more related listed items.

[0037] In the description of the embodiments of the present application, the technical terms "first", "second", etc. are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implicitly indicating the number, specific order or primary and secondary relationship of the indicated technical features. In the description of the embodiments of the present application, the meaning of "multiple" is more than two, unless otherwise clearly and specifically defined.

[0038] Reference to "embodiment" herein 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 locations 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. The various embodiments in the present application may be combined with each other in the absence of conflict.

[0039] Figure 1 A schematic diagram of the structure of a cylindrical battery according to an embodiment of the present application is shown in FIG. Figure 1 As shown, in the first aspect, the embodiment of the present application provides a cylindrical battery 10, which can be a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid (or lead storage) battery, a lithium-ion battery, a polymer lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, etc. The axis of the cylindrical battery 10 is L0. The radial direction of the cylindrical battery 10 is X, and X is in a plane perpendicular to the axis L0, which is the direction from the axis L0 to the outside of the cylindrical battery 10. The axial direction of the cylindrical battery 10 is Y, and Y is parallel to the axis L0 of the cylindrical battery 10.

[0040] The diameter of the cylindrical battery is D. In one or more embodiments, 31mm≦D≦101mm. But not limited to this. For example, D can be: 31mm, 35mm, 40mm, 45mm, 50mm, 55mm, 60mm, 65mm, 70mm, 75mm, 80mm, 85mm, 90mm, 95mm, 100mm, 101mm, or a value between any two values. Within this D range, the diameter D of the cylindrical battery 10 is larger, which is conducive to improving the capacity of the cylindrical battery 10, making the cylindrical battery 10 suitable for high-power and long-endurance application scenarios.

[0041] Along the axial direction Y of the cylindrical battery 10, the length of the cylindrical battery 10 is L. In one or more embodiments, 40mm≦L≦250mm. But not limited to this. For example, L can be: 40mm, 50mm, 60mm, 70mm, 80mm, 90mm, 100mm, 110mm, 120mm, 130mm, 140mm, 150mm, 160mm, 170mm, 180mm, 190mm, 200mm, 210mm, 220mm, 230mm, 240mm, 250mm, or a value between any two values. Within this L range, the length L of the cylindrical battery is relatively large, which is conducive to improving the capacity of the cylindrical battery 10, making the cylindrical battery 10 suitable for high-power and long-endurance application scenarios.

[0042] Figure 2 for Figure 1 The partial cross-sectional structure diagram of the cylindrical battery 10 is shown in FIG. Figure 2As shown, the cylindrical battery 10 includes: a shell 100, an electrode assembly 200 and a top cover 300. The electrode assembly 200 is disposed in the shell 100; the top cover 300 is insulated and connected to the shell 100, and is arranged along the axial direction Y of the cylindrical battery 10 with the electrode assembly 200; the top cover 300 includes a substrate portion 310, an end face portion 320 and a plurality of connecting portions 330; the substrate portion 310 is insulated and connected to the shell 100, and the plurality of connecting portions 330 are arranged at intervals and surround the end face portion 320, and the plurality of connecting portions 330 connect the end face portion 320 and the substrate portion 310.

[0043] In one or more embodiments, the cylindrical battery 10 further includes a bursting disc 400 , which connects the top cover 300 and the electrode assembly 200 .

[0044] Figure 3 for Figure 1 The top cover 300 of the cylindrical battery 10 is shown in FIG. Figure 3 As shown, when viewed along the axial direction Y, the connection portion 330 extends around the center 321 of the end face portion 320, and the connection portion 330 has a first end 330a and a second end 330b on the radial direction X of the cylindrical battery 10 away from the center 321 of the end face portion 320. The line connecting the first end 330a and the center 321 of the end face portion 320 is the first line 331, and the line connecting the second end 330b and the center 321 of the end face portion 320 is the second line 332. The first line 331 and the second line 332 intersect to form a first angle α, and multiple connection portions 330 form multiple first angles α, and the sum of multiple first angles α is A, 120°≤A≤210°, but not limited thereto. For example, A can be: 120°, 130°, 140°, 150°, 160°, 170°, 180°, 190°, 200°, 210°, or a value between any two values ​​therebetween.

[0045] In one or more embodiments, along the axial direction Y, a portion 410 of the explosion-proof disc 400 is disposed between the end face portion 320 and the electrode assembly 200, and the portion 410 of the explosion-proof disc 400 is configured to flip when the gas pressure in the cylindrical battery 10 reaches a first threshold value P1, and disconnect from the electrode assembly; the explosion-proof disc 400 explodes when the gas pressure in the cylindrical battery 10 reaches a second threshold value P2, so that the gas inside and outside the shell of the cylindrical battery 10 are connected. When the portion 410 of the explosion-proof disc 400 is disconnected from the electrode assembly 200, the internal current path of the cylindrical battery 10 is cut off, which is conducive to reducing the loss caused by the continuous short circuit of the cylindrical battery 10. After the explosion-proof disc 400 explodes, the high-pressure gas in the shell 100 of the cylindrical battery 10 is discharged to the outside and the pressure is relieved, which is conducive to improving the safety of the cylindrical battery 10.

[0046] In one or more embodiments, 1.1 MPa≤P1≤1.3 MPa, but not limited thereto. For example, P1 may be: 1.10 MPa, 1.12 MPa, 1.14 MPa, 1.16 MPa, 1.18 MPa, 1.20 MPa, 1.22 MPa, 1.24 MPa, 1.26 MPa, 1.28 MPa, 1.30 MPa, or a value between any two values.

[0047] In one or more embodiments, 1.9 MPa≤P2≤2.1 MPa, but not limited thereto. For example, P2 may be: 1.90 MPa, 1.92 MPa, 1.94 MPa, 1.96 MPa, 1.98 MPa, 2.00 MPa, 2.02 MPa, 2.04 MPa, 2.06 MPa, 2.08 MPa, 2.10 MPa, or a value between any two values.

[0048] The embodiment of the present scheme increases the sum A of the multiple first angles, thereby increasing the connection range between the connection portion 330 and the end surface portion 320 and the base plate portion 310, which is beneficial to enhancing the structural strength of the top cover 300, improving the deformation resistance of the top cover 300 after being driven by the internal components of the shell 100 (such as the overturning of the explosion-proof disk), reducing the degree of increase in the overturning distance of the explosion-proof disk caused by the deformation of the top cover 300, improving the stability of power-off and pressure relief of the cylindrical battery 10, and improving the safety performance of the cylindrical battery 10.

[0049] In one or more embodiments, the plurality of first angles α are all equal. In one or more embodiments, some of the plurality of first angles α are equal and some are not equal. In one or more embodiments, the plurality of first angles α are not equal.

[0050] In the embodiment of this scheme, by increasing the connection range between the connection portion 330 and the end surface portion 320 and the substrate portion 310, the structural strength of the top cover 300 is enhanced, which is beneficial to improving the deformation resistance of the top cover 300, reducing the degree to which the overturning distance of the explosion-proof plate increases due to the deformation of the top cover 300, improving the stability of the power-off and pressure relief of the cylindrical battery 10, and improving the safety performance of the cylindrical battery 10. In one or more embodiments, 150°≤A≤210°. By further increasing the connection range between the connection portion 330 and the end surface portion 320 and the substrate portion 310, it is beneficial to further enhance the structural strength of the top cover 300, improve the stability of the power-off and pressure relief of the cylindrical battery 10, and improve the safety performance of the cylindrical battery 10.

[0051] In one or more embodiments, 180°≤A≤210°. By further increasing the connection range between the connection portion 330 and the end face portion 320 and the substrate portion 310, A≥180° further enhances the structural strength of the top cover 300, improves the stability of power-off and pressure relief of the cylindrical battery 10, and improves the safety performance of the cylindrical battery 10. A≤210°, by making the connection range between the connection portion 330 and the end face portion 320 and the substrate portion 310 within a certain range, it is beneficial to reduce the obstruction of the connection portion 330 to the pressure relief and exhaust of the cylindrical battery 10 from the inside to the outside, reduce the pressure relief time of the cylindrical battery 10, and improve the safety performance of the cylindrical battery 10.

[0052] In one or more embodiments, when observed along the axial direction Y, the connecting portion 330 includes a first supporting wall 333 and a second supporting wall 334 that are interconnected, and the second supporting wall 334 protrudes from the end surface of the first supporting wall 333 in the radial direction X, which is away from the center 321 of the end surface portion 320, which is beneficial to improve the structural strength of the connecting portion 330, reduce the possibility of deformation of the top cover 300, improve the stability of power-off and pressure relief of the cylindrical battery 10, and improve the safety performance of the cylindrical battery 10.

[0053] In one or more embodiments, observed along the axial direction Y, the second support wall 334 has a third end 330c and a fourth end 330d on the side radially away from the center 321 of the end surface portion 320; the line connecting the third end 330c and the center 321 is the third line 335, and the line connecting the fourth end 330d and the center 321 is the fourth line 336, and the third line 335 and the fourth line 336 intersect to form a second angle β, 1 / 4≤β / α≤1 / 2, but is not limited to this. For example, β / α may be 0.25, 0.26, 0.27, 0.28, 0.29, 0.30, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.40, 0.41, 0.42, 0.43, 0.44, 0.45, 0.46, 0.47, 0.48, 0.49, 0.5, or a value between any two values. In the above β / α ratio range, it is beneficial to improve the structural strength of the connecting portion 330, thereby improving the anti-deformation ability of the top cover 300.

[0054] In one or more embodiments, the plurality of second angles β are all equal. In one or more embodiments, some of the plurality of second angles β are equal and some are not equal. In one or more embodiments, the plurality of second angles β are not equal.

[0055] like Figure 2 and Figure 3As shown, in one or more embodiments, viewed along the axial direction Y, along the radial direction X, the distance that the second support wall 334 protrudes from the end surface of the first support wall 333 away from the center 321 of the end surface 320 is L1; the thickness of the end surface 320 is L2; ​​1≤L1 / L2≤2, but not limited thereto. For example, L1 / L2 can be: 1, 1.05, 1.10, 1.15, 1.20, 1.25, 1.30, 1.35, 1.40, 1.45, 1.50, 1.55, 1.60, 1.65, 1.70, 1.75, 1.80, 1.85, 1.90, 1.95, 2, or a value between any two values. In the above-mentioned ratio range of L1 / L2, the second support wall 334 protrudes a certain distance from the end surface of the first support wall 333 facing away from the center 321 of the end surface portion 320 in the radial direction X, which is beneficial to improve the structural strength of the connecting portion 330 and further improve the deformation resistance of the top cover 300.

[0056] In one or more embodiments, 0.6 mm ≤ L2 ≤ 1 mm, but not limited thereto. For example, L2 may be: 0.6 mm, 0.65 mm, 0.70 mm, 0.75 mm, 0.80 mm, 0.85 mm, 0.90 mm, 0.95 mm, 1 mm, or a value between any two values. Setting the thickness of the end surface portion 320 within the above range is conducive to improving the anti-deformation ability of the top cover 300.

[0057] In one or more embodiments, Figure 2 As shown, a plurality of connection parts 330 are evenly spaced along the circumference of the end face part 320, and a pressure relief hole 340 is provided between two adjacent connection parts 330. The pressure relief hole 340 is used to discharge the gas inside the cylindrical battery 10 for pressure relief, thereby reducing the risk of explosion and fire of the cylindrical battery 10. Specifically, when observed along the axial direction Y, with the center 321 of the end face part 320 as the center of the circle, the center angles of the adjacent connection parts 330 are equal. For example, when the top cover 300 includes three connection parts 330, the sum of the center angles of one connection part 330 and the center angles of the adjacent connection parts 330 is 120°. When the top cover 300 includes four connection parts 330, the sum of the center angles of one connection part 330 and the center angles of the adjacent connection parts 330 is 90°.

[0058] like Figure 3As shown, in one or more embodiments, the radius of the circumscribed circle of the end face portion 320 is r, the radius of the top cover 300 is R, 1 / 3≤r / R≤2 / 3, but not limited thereto. For example, r / R can be: 10 / 30, 11 / 30, 12 / 30, 13 / 30, 14 / 30, 15 / 30, 16 / 30, 17 / 30, 18 / 30, 19 / 30, 20 / 30, or a value between any two values. In the above-mentioned r / R ratio range, it is beneficial to provide a larger turning space for the explosion-proof plate inside the top cover 300, and provide a smooth pressure relief channel for the internal pressure relief of the cylindrical battery 10, thereby improving the stability of the power-off and pressure relief of the cylindrical battery 10 and improving the safety performance of the cylindrical battery 10.

[0059] In one or more embodiments, the number of the connecting parts 330 is three or four. The above number of connecting parts 330 is used to facilitate production and processing, thereby reducing the production cost of the cylindrical battery 10.

[0060] In one or more embodiments, the material of the top cover 300 includes nickel-plated carbon steel. The above material is not easy to rust, which is conducive to improving the durability of the top cover 300. In addition, the nickel-plated carbon steel has a high strength, which is conducive to enhancing the structural strength of the top cover 300, reducing the deformation of the top cover 300 after being impacted by the internal pressure of the shell 100, reducing the degree of increase in the flipping distance of the explosion-proof plate caused by the deformation of the top cover 300, improving the stability of the power-off and pressure relief of the cylindrical battery 10, and improving the safety performance of the cylindrical battery 10.

[0061] In a second aspect, the present application provides a battery pack 20, Figure 4 A schematic diagram of the structure of the battery pack provided in the embodiment of the present application, such as Figure 4 As shown, the battery pack 20 includes the cylindrical battery 10 of any of the above embodiments. There is at least one cylindrical battery 10. In one or more embodiments, there are multiple cylindrical batteries 10, and the multiple cylindrical batteries 10 are connected in series or in parallel, or the multiple cylindrical batteries 10 are combined in series and in parallel.

[0062] In a third aspect, the present application provides an electrical device 30, comprising a cylindrical battery 10 or a battery pack 20 according to any of the above embodiments.

[0063] In one or more embodiments, Figure 5 A schematic diagram of the structure of the first electrical device provided in the embodiment of the present application is shown in FIG. Figure 5 As shown, the electric device 30 includes the battery pack 20 in the above embodiment, and the battery pack 20 includes the cylindrical battery 10 in the above embodiment.

[0064] In one or more embodiments, Figure 6 A schematic diagram of the structure of a second electrical device provided in an embodiment of the present application is shown in FIG. Figure 6As shown, the electric device 30 includes the cylindrical battery 10 in the above embodiment.

[0065] The present application does not specifically limit the electrical device, and the electrical device includes electrical devices known in the prior art. For example, the electrical device includes but is not limited to a backup power supply, a two-wheeled vehicle, an unmanned aerial vehicle, a power tool, or an energy storage device.

[0066] Test method for top cover deformation:

[0067] Industrial CT (Zeiss Xradia 620 Versa) was used to observe the position change of the end face portion 320 of the cylindrical battery before and after the explosion test. Figure 7 FIG. 1 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery before an explosion test according to an embodiment of the present application. Figure 7 As shown, the height H1 from the top 310a of the edge of the substrate portion of the top cover 300 to the lower surface 320a of the edge of the end face portion is measured. Figure 8 FIG. 1 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery after an explosion test according to an embodiment of the present application. Figure 8 As shown, the height H2 from the top 310a of the edge of the substrate portion of the top cover 300 to the lower surface 320a of the edge of the end face portion is measured, and the difference H2-H1 before and after the explosion test is calculated to obtain the deformation size δ of the top cover, δ=H2-H1.

[0068] When measuring heights H1 and H2, 10 points are taken at the top 310a of the edge of the substrate portion of the top cover 300, and the heights from the 10 points to the lower surface 320a of the edge of the end face portion are calculated. The average is taken to obtain the height from the top 310a of the edge of the substrate portion of the top cover 300 to the lower surface 320a of the edge of the end face portion.

[0069] Preparation and testing of the battery cells of each embodiment and comparative example:

[0070] Preparation of cylindrical batteries: groove the empty steel shell according to the production line process, insert the cap including the top cover and the explosion-proof disk, and seal the cylindrical battery. Use drilling equipment to drill a circular hole at the bottom of the cylindrical battery shell. The diameter of the circular hole is 5mm. The design value of the explosion of the explosion-proof disk of the cylindrical battery (i.e., the second threshold) is 2MPa;

[0071] Fixture fixation: Use a fixture (self-made) to fix the cylindrical battery and compress the sealing ring that contacts the bottom of the cylindrical battery shell to seal;

[0072] Explosion test: Use a pneumatic burst tester (model SC-QYBP-10, Xiamen Sanchuang Keyi Testing Equipment Co., Ltd.), open the inflation valve, and inflate the inside of the shell through the circular hole at the bottom of the shell at a speed of 0.1Mpa / s. Maintain the pressure after reaching 1.8Mpa, and end the test after maintaining the pressure for 10 minutes.

[0073] Embodiment 1:

[0074] The cylindrical battery top cover is prepared with three connecting parts, the first angle of each connecting part is equal, and each connecting part is not provided with a second supporting wall. The specific preparation parameters of D, L, α, M, A, r, R, and L2 of the cylindrical battery are shown in Table 1.

[0075] Embodiment 2 to embodiment 4:

[0076] Except for adjusting the relevant preparation parameters according to Table 1, the rest is the same as Example 1.

[0077] Embodiment 5 to embodiment 7:

[0078] Different from Example 1, in this embodiment, each connecting portion is provided with a second supporting wall. The specific data of D, L, α, M, A, r, R, L1, L2, and β of the cylindrical battery are shown in Table 1. Except for adjusting the relevant preparation parameters according to Table 1, the rest is the same as Example 1.

[0079] Embodiment 8 to embodiment 10:

[0080] Except for adjusting the relevant preparation parameters according to Table 1, the rest is the same as Example 1.

[0081] Comparative Example 1

[0082] Except for adjusting the relevant preparation parameters according to Table 1, the rest is the same as Example 1.

[0083] The parameters and performance of each embodiment and comparative example of the present application are described below. The preparation parameters and performance tests of each embodiment and comparative example are shown in Table 1.

[0084] Table 1

[0085]

[0086] The annotations for the parameters in Table 1 are as follows:

[0087] D is the diameter of the cylindrical battery, in mm;

[0088] L is the length of the cylindrical battery, in mm;

[0089] α is the first angle of the connection part, in degrees;

[0090] M is the number of connecting parts, in pieces;

[0091] A is the sum of the first angles of the multiple connecting parts, in degrees;

[0092] r is the radius of the circumscribed circle of the end face, in mm;

[0093] R is the radius of the top cover, in mm;

[0094] L1 is the distance that the second support wall protrudes from the end surface of the first support wall away from the center of the end surface portion, in mm;

[0095] L2 is the thickness of the end face, in mm;

[0096] β is the second angle of the second supporting wall, in degrees;

[0097] δ is the deformation size of the top cover after the explosion test with a pressure of 1.8 MPa, in mm.

[0098] By comparing Examples 1 to 10 with Comparative Example 1, it can be seen that the sum A of the first angles of multiple connecting parts of Examples 1 to 10 is greater than the sum A of the first angles of multiple connecting parts of Comparative Example 1, and the deformation dimensions δ of the top cover before and after the explosion test of Examples 1 to 10 are less than the deformation dimensions δ of the top cover before and after the explosion test of Comparative Example 1. Therefore, increasing the sum A of the first angles of multiple connecting parts is beneficial to enhancing the structural strength of the top cover, reducing the extent to which the flipping distance of the explosion-proof plate increases due to deformation of the top cover, improving the stability of power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0099] By comparing Examples 1 to 4 with Comparative Example 1, it can be seen that the sum A of the first angles of the multiple connecting parts of Examples 1 to 4 gradually increases, and the deformation size δ of the top cover before and after the explosion test of Examples 1 to 4 gradually decreases compared with Comparative Example 1. Therefore, increasing the sum A of the first angles of the multiple connecting parts is conducive to enhancing the structural strength of the top cover, reducing the degree to which the flipping distance of the explosion-proof plate increases due to the deformation of the top cover, improving the stability of the power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0100] By comparing Examples 5 to 7 with Examples 1 to 4, it can be seen that Examples 5 to 7 are provided with a second support wall, and the deformation dimension δ of the top cover before and after the explosion test is smaller than that of Example 1. And the greater the distance that the second support wall protrudes from the end face of the first support wall back to the center of the end face, the smaller the deformation dimension δ of the top cover; the greater the second angle of the second support wall, the smaller the deformation dimension δ of the top cover. Therefore, by providing the second support wall, it is beneficial to enhance the structural strength of the top cover, reduce the degree to which the flipping distance of the explosion-proof plate increases due to the deformation of the top cover, improve the stability of the power-off and pressure relief of the cylindrical battery, and improve the safety performance of the cylindrical battery.

[0101] By comparing Example 8 and Example 9 with Example 1, it can be seen that when the top cover radius R is the same, as the radius of the circumscribed circle of the end face of Example 8, Example 1, and Example 9 gradually increases, the deformation size δ of the top cover before and after the explosion test gradually decreases. Therefore, by increasing the radius of the circumscribed circle of the end face, it is helpful to reduce the degree to which the flipping distance of the explosion-proof plate increases due to the deformation of the top cover, improve the stability of the power-off and pressure relief of the cylindrical battery, and improve the safety performance of the cylindrical battery.

[0102] By comparing Example 10 with Example 1, it can be seen that when the sum A of the first angles of the multiple connecting parts is the same, the increase in the number of connecting parts is beneficial to reducing the extent to which the flipping distance of the explosion-proof plate becomes larger due to the deformation of the top cover, improving the stability of power-off and pressure relief of the cylindrical battery, and improving the safety performance of the cylindrical battery.

[0103] The above description is only a preferred embodiment of the present application and is not intended to limit the protection scope of the present application.

Claims

1. A cylindrical battery, characterized in that: include: case; An electrode assembly is disposed in the housing; A top cover, insulated and connected to the shell, and arranged along the axial direction of the cylindrical battery with the electrode assembly; The top cover comprises a base plate portion, an end surface portion and a plurality of connection portions, wherein the base plate portion is insulated and connected to the housing, the plurality of connection portions are arranged at intervals and surround the end surface portion, and the plurality of connection portions connect the end surface portion and the base plate portion; When observed along the axial direction, the connecting portion extends around the center of the end face portion, and the connecting portion has a first end and a second end on the side away from the center of the end face portion in the radial direction of the cylindrical battery, the line connecting the first end and the center of the end face portion is the first line, and the line connecting the second end and the center of the end face portion is the second line, the first line and the second line intersect to form a first angle α, the sum of multiple first angles α is A, 120°≤A≤210°.

2. The cylindrical battery according to claim 1, characterized in that: 150°≤A ≤210°。 3. The cylindrical battery according to claim 2, characterized in that: 180°≤A ≤210°。 4. The cylindrical battery according to any one of claims 1 to 3, characterized in that: When viewed along the axial direction, the connecting portion includes a first supporting wall and a second supporting wall connected to each other, and the second supporting wall protrudes from an end surface of the first supporting wall facing away from the center of the end surface portion in the radial direction.

5. The cylindrical battery according to claim 4, characterized in that: When viewed along the axial direction, the second support wall has a third end and a fourth end on a side away from the center of the end surface portion in the radial direction; A line connecting the third end and the center of the end face portion is a third line, a line connecting the fourth end and the center of the end face portion is a fourth line, and the third line and the fourth line intersect to form a second angle β, 1 / 4≤β / α≤1 / 2.

6. The cylindrical battery according to claim 4, characterized in that: When viewed along the axial direction, along the radial direction, the second support wall protrudes from the end surface of the first support wall facing away from the center of the end surface portion by a distance L1; The thickness of the end face portion is L2; 1≤L1 / L2≤2.

7. The cylindrical battery according to claim 6, characterized in that: 0.6mm≤L2≤1mm.

8. The cylindrical battery according to any one of claims 1 to 7, characterized in that: The radius of the circumscribed circle of the end surface portion is r, the radius of the top cover is R, and 1 / 3≤r / R≤2 / 3.

9. The cylindrical battery according to claim 8, characterized in that: 15mm≤R≤50mm.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: The cylindrical battery also includes an explosion-proof plate, which connects the top cover and the electrode assembly. Along the axial direction, a portion of the explosion-proof plate is arranged between the end surface portion and the electrode assembly, and the portion is configured to flip over and disconnect from the electrode assembly when the air pressure in the cylindrical battery reaches a first threshold value; the explosion-proof plate explodes when the air pressure in the cylindrical battery reaches a second threshold value, so that the gas inside and outside the shell of the cylindrical battery is connected.

11. The cylindrical battery according to any one of claims 1 to 10, characterized in that: The number of the connecting parts is three or four.

12. The cylindrical battery according to any one of claims 1 to 11, characterized in that: The material of the top cover includes nickel-plated carbon steel.

13. A battery pack, characterized in that: A cylindrical battery comprising any one of claims 1 to 12.

14. An electrical device, characterized in that: The invention comprises the cylindrical battery according to any one of claims 1 to 12 or the battery pack according to claim 13.

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