Cylindrical battery, battery pack and power utilization device

Abstract

The embodiment of the invention provides a cylindrical battery, a battery pack and an electric device. The cylindrical battery comprises a shell, an electrode assembly and an end cover, the end cover comprises a base body and an end part, the base body comprises a first part and a second part, and the projection of the first part surrounds the projection of the second part in the axial direction. The first part is in insulated connection with the shell; the second part is connected with the first part and the end part; the first portion includes a first surface facing the electrode assembly, and the second portion includes a second surface facing the electrode assembly, the second surface being closer to the end portion than the first surface in the axial direction. And the second surface of the second part is closer to one side of the end part, so that a larger accommodating space is favorably provided for the electrode assembly in the shell of the cylindrical battery, the volume of the electrode assembly is favorably increased, and the energy density of the cylindrical battery is improved.

Description

Technical Field

[0001] The present invention 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] A CID (current interrupt device, abbreviated as CID, current cut-off device) is usually provided inside the cylindrical battery. The CID is electrically connected to the end cap. When an abnormality occurs in the cylindrical battery, the CID can cut off the internal current of the cylindrical battery to improve the safety of the cylindrical battery.

[0003] Among them, the conventional structure of the end cap and CID limits the available space of the electrode assembly, which is not conducive to improving the energy density of the cylindrical battery. Summary of the invention

[0004] The purpose of the embodiments of the present invention is to provide a cylindrical battery, a battery pack and an electrical device, which are beneficial to improving the energy density of the cylindrical battery.

[0005] The first aspect of the present application provides a cylindrical battery, comprising: a shell; an electrode assembly, arranged in the shell; an end cap, arranged in the shell, along the axial direction of the cylindrical battery, the electrode assembly and the end cap are arranged in sequence, the end cap comprises a base and an end, the end protrudes from the base along the axial direction, and along the axial direction, the projection of the base surrounds the projection of the end; the base comprises a first part and a second part, along the axial direction, the projection of the first part surrounds the projection of the second part, the first part is insulated and connected to the shell, and the second part connects the first part and the end; the first part comprises a first surface facing the electrode assembly, and the second part comprises a second surface facing the electrode assembly, and along the axial direction, the second surface is closer to the end than the first surface. The second surface of the second part is closer to the end, so that it is beneficial to provide a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, which is beneficial to increase the volume of the electrode assembly and improve the energy density of the cylindrical battery.

[0006] In one or more embodiments, the second portion is bent relative to the first portion away from the electrode assembly, and a first space is formed on the side of the second portion facing the electrode assembly; a burst-proof disk, a portion of which is disposed in the first space. On the one hand, when the pressure in the cylindrical battery shell reaches a first threshold, the valve of the burst-proof disk opens, which is beneficial to relieving the pressure of the cylindrical battery. On the other hand, the second portion is bent relative to the first portion away from the electrode assembly to form the first space, and a portion of the burst-proof disk is disposed in the first space, which is beneficial for the burst-proof disk to be close to the end, providing a larger accommodation space for the electrode assembly in the cylindrical battery shell, which is beneficial to increase the volume of the electrode assembly and improve the energy density of the cylindrical battery.

[0007] In one or more embodiments, the explosion-proof disc includes a main body, a bent portion, and a connecting portion arranged along the radial direction of the cylindrical battery, the connecting portion is connected to the first portion, and at least a portion of the bent portion is disposed in the first space. This facilitates the explosion-proof disc to be closer to the end, providing a larger accommodation space for the electrode assembly in the housing of the cylindrical battery, which is conducive to increasing the volume of the electrode assembly and improving the energy density of the cylindrical battery.

[0008] In one or more embodiments, the portion where the main body is connected to the bent portion has a third surface facing the electrode assembly; the portion where the connecting portion is connected to the bent portion has a fourth surface facing the electrode assembly; in the axial direction, the distance between the third surface and the fourth surface does not exceed 0.1 mm. The connecting portion and the main body do not occupy too much accommodation space in the shell, and the main body of the explosion-proof disk is closer to the end, providing a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, which is conducive to increasing the volume of the electrode assembly and improving the energy density of the cylindrical battery.

[0009] In one or more embodiments, the bending portion is bent relative to the connecting portion and the main body, away from the electrode assembly, and a second space is formed on the side of the bending portion facing the electrode assembly; the connecting plate is connected to the explosion-proof disc; the insulating member is axially arranged, and at least part of the insulating member is arranged between the connecting plate and the explosion-proof disc, and is located in the second space. On the one hand, when the pressure in the cylindrical battery shell reaches the second threshold, the explosion-proof disc flips, so that the connecting plate and the explosion-proof disc are disconnected, which is conducive to cutting off the current of the cylindrical battery and improving the safety of the cylindrical battery. On the other hand, at least part of the insulating member is arranged between the connecting plate and the explosion-proof disc, and is located in the second space. The insulating member does not increase the distance between the connecting plate and the explosion-proof disc along the axial direction, which is conducive to the connecting plate being closer to the end, providing a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, which is conducive to increasing the volume of the electrode assembly and improving the energy density of the cylindrical battery.

[0010] In one or more embodiments, the shell includes a side wall surrounding the electrode assembly, the side wall is provided with a convex portion protruding toward the axis of the cylindrical battery, and a portion of the end cap is located on the side of the convex portion facing away from the electrode assembly; along the axial direction, the convex portion includes a first proximal end close to the electrode assembly, and the end portion includes a first distal end away from the electrode assembly, and along the axial direction, the distance between the first proximal end and the first distal end is L1, and along the axial direction, the connecting plate includes a second proximal end close to the electrode assembly, and along the axial direction, the distance between the second proximal end and the first distal end is L2; ​​60%≤L2 / L1≤80%. Along the axial direction, relative to the first proximal end of the convex portion, the connecting plate is conducive to being closer to the first distal end, providing a larger accommodating space for the electrode assembly in the shell of the cylindrical battery, increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0011] In one or more embodiments, 60%≤L2 / L1≤70%. In the axial direction, relative to the first proximal end of the protrusion, the connecting plate is closer to the first distal end, providing a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0012] In one or more embodiments, 2.5 mm ≤ L2 ≤ 3.5 mm. In the axial direction, the distance between the second proximal end and the first distal end is small, and the connecting plate is closer to the first distal end than the first proximal end of the convex portion, which is beneficial to provide a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, increase the volume of the electrode assembly, and improve the energy density of the cylindrical battery.

[0013] In one or more embodiments, a portion of the insulating member extends to a side of the connecting plate away from the axis of the cylindrical battery, which is beneficial for the insulating member to limit the connecting plate in the radial direction of the cylindrical battery and improve the position stability of the connecting plate.

[0014] In one or more embodiments, the main body includes a central area protruding toward the connecting plate, and the central area is welded to the connecting plate; along the direction from the end cap to the electrode assembly, the distance from the central area beyond the third surface is L3, 0.1mm≤L3≤0.2mm. Along the direction from the end cap to the electrode assembly, the distance from the central area beyond the third surface is small, which is conducive to reducing the spacing between the third surface of the main body and the connecting plate, providing a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0015] In one or more embodiments, the connecting plate includes a fifth surface, the fifth surface is on a side away from the electrode assembly, and the fifth surface is a flush surface. The fifth surface of the connecting plate on the side away from the electrode assembly is flush, which is conducive to reducing the distance between the third surface of the main body and the connecting plate along the axial direction, providing a larger accommodating space for the electrode assembly in the shell of the cylindrical battery, increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0016] A second aspect of the present application provides a battery pack comprising a cylindrical battery in any of the above embodiments.

[0017] 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.

[0018] Beneficial effects of the embodiments of the present invention:

[0019] The cylindrical battery, battery pack and electrical device provided by the embodiment of the present invention include a shell, an electrode assembly and an end cap. The end cap includes a base and an end portion, the end portion protrudes from the base portion in the axial direction, and the projection of the base portion surrounds the projection of the end portion in the axial direction; the base includes a first part and a second part, and the projection of the first part surrounds the projection of the second part in the axial direction. The first part is insulated and connected to the shell, and the second part connects the first part and the end portion; the first part includes a first surface facing the electrode assembly, and the second part includes a second surface facing the electrode assembly, and the second surface is closer to the end portion than the first surface in the axial direction. The second surface of the second part is closer to the end portion, which is beneficial to provide a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, which is beneficial to increase the volume of the electrode assembly and improve the energy density of the cylindrical battery. Of course, any product implementing the present invention does not necessarily need to achieve all the advantages described above at the same time. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the embodiments of the present invention 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 invention, and a person skilled in the art can also obtain other drawings based on these drawings.

[0021] Figure 1 A schematic diagram of the structure of a cylindrical battery according to an embodiment of the present application;

[0022] Figure 2 for Figure 1 A schematic diagram of a partial cross-sectional structure of a cylindrical battery shown;

[0023] Figure 3 for Figure 2 A magnified view of middle;

[0024] Figure 4 for Figure 1 Schematic diagram of the end cover structure of the cylindrical battery shown;

[0025] Figure 5 for Figure 1 Schematic diagram of the explosion-proof plate structure of the cylindrical battery shown;

[0026] Figure 6 for Figure 1 Schematic diagram of the connecting plate structure of a cylindrical battery shown;

[0027] Figure 7 for Figure 1 A schematic diagram of the insulating structure of a cylindrical battery shown;

[0028] Figure 8 is a schematic diagram of the structure of a battery pack provided in an embodiment of the present application;

[0029] Fig. 9 It is a structural schematic diagram of a first type of electrical device provided in an embodiment of the present application;

[0030] Fig.10 It is a structural schematic diagram of a second electrical device provided in an embodiment of the present application.

[0031] The reference numerals are as follows:

[0032] Shell 10, side wall 11, convex portion 111, first proximal end 111a, electrode assembly 20, end cap 30, substrate 31, first portion 311, first surface 311a, second portion 312, second surface 312a, end portion 32, first distal end 32a, explosion-proof disk 40, main body 41, central area 411, third surface 41a, bent portion 42, connecting portion 43, fourth surface 43a, connecting plate 50, second proximal end 50a, fifth surface 50b, insulating member 60;

[0033] Cylindrical battery 100, battery pack 200, power-consuming device 300;

[0034] Radial direction X, axial direction Y, first space K1, second space K2, axis line L. DETAILED DESCRIPTION

[0035] The technical solutions in the embodiments of the present application will be clearly and completely 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, rather than all of the embodiments.

[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] In the related art, the base of the cylindrical battery end cap is an annular flat plate as a whole, which easily limits the space inside the cylindrical battery to accommodate the electrode assembly and affects the energy density of the cylindrical battery.

[0040] The present application provides a cylindrical battery, a battery pack and an electrical device, the main purpose of which is to increase the energy density of the cylindrical battery.

[0041] 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 100, 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 100 is L. The radial direction of the cylindrical battery 100 is X, and X is in a plane perpendicular to the axis L, which is the direction from the axis L to the outside of the cylindrical battery 100. The axial direction of the cylindrical battery 100 is Y, and Y is parallel to the axis L of the cylindrical battery 100.

[0042] Figure 2 for Figure 1 The partial cross-sectional structure diagram of the cylindrical battery shown in FIG. Figure 1 and Figure 2 As shown, a first aspect of the present application provides a cylindrical battery 100 , which includes a housing 10 , an electrode assembly 20 , and an end cap 30 .

[0043] The electrode assembly 20 is disposed in the housing 10. One end of the housing 10 has an opening (not shown), and the end cap 30 is disposed in the housing 10 and covers the opening. The electrode assembly 20 and the end cap 30 are disposed in sequence along the axial direction Y of the cylindrical battery 100. The end cap 30 includes a base 31 and an end 32. The end 32 protrudes from the base 31 along the axial direction Y. Along the axial direction Y, the projection of the base 31 surrounds the projection of the end 32. The base 31 includes a first portion 311 and a second portion 312. Along the axial direction Y, the projection of the first portion 311 surrounds the projection of the second portion 312. The first portion 311 is insulated and connected to the housing 10, and the second portion 312 connects the first portion 311 and the end 32. The first portion 311 includes a first surface 311a facing the electrode assembly 20, and the second portion 312 includes a second surface 312a facing the electrode assembly 20. Along the axial direction Y, the second surface 312a is closer to the end 32 than the first surface 311a.

[0044] In the cylindrical battery 100 provided in the embodiment of the present invention, the second surface 312a of the second portion 312 is closer to the end portion 32, thereby facilitating the provision of a larger accommodation space for the electrode assembly 20 within the shell 10 of the cylindrical battery 100, facilitating the increase in the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0045] In one or more embodiments, the cylindrical battery 100 further includes a CID, the CID electrically connecting the electrode assembly 20 and the end cap 30 , and the CID includes a burst disk 40 . Figure 3 for Figure 2 A magnified image of Figure 4 for Figure 1 The end cover 30 structure diagram of the cylindrical battery 100 is shown in FIG. Figure 3 and Figure 4 As shown, in one or more embodiments, the second portion 312 is bent relative to the first portion 311 away from the electrode assembly 20, and a first space K1 is formed on the side of the second portion 312 facing the electrode assembly 20. A portion of the explosion-proof disk 40 is disposed in the first space K1.

[0046] The explosion-proof disc 40 has a valve port. When the cylindrical battery 100 fails and the internal air pressure reaches the first threshold, the valve port of the explosion-proof disc 40 opens, and the high-pressure gas in the housing 10 is released outward through the valve port of the explosion-proof disc 40, which is beneficial to relieve the pressure of the cylindrical battery 100 and improve the safety of the cylindrical battery 100. On the other hand, the second part 312 is bent relative to the first part 311 away from the electrode assembly 20 to form a first space K1, and a part of the explosion-proof disc 40 is arranged in the first space K1. In the embodiment of this scheme, the second part 312 of the end cover 30 is changed from a conventional straight structure to a convex (along the axial direction Y) bending structure, which drives the explosion-proof disc 40 to convex (along the axial direction Y), reduces the distance between the explosion-proof disc 40 and the end cover 30, and increases the space between the end cover 30 and the bottom wall of the cylindrical battery 100, which is beneficial to provide a longer accommodation space in the axial direction Y for the electrode assembly 20 in the housing 10 of the cylindrical battery 100, which is beneficial to increase the volume of the electrode assembly 20 and improve the energy density of the cylindrical battery 100.

[0047] Figure 5 for Figure 1 The schematic diagram of the explosion-proof plate 40 of the cylindrical battery 100 is shown in FIG. Figure 3 and Figure 5 As shown, in one or more embodiments, the explosion-proof disc 40 includes a main body 41, a bent portion 42 and a connecting portion 43 arranged along the radial direction X of the cylindrical battery 100, and the connecting portion 43 is connected to the first portion 311; at least part of the bent portion 42 is disposed in the first space K1. This facilitates the explosion-proof disc 40 to be closer to the end 32, providing a larger accommodation space for the electrode assembly 20 in the housing 10 of the cylindrical battery 100, which is conducive to increasing the volume of the electrode assembly 20 and improving the energy density of the cylindrical battery 100.

[0048] In one or more embodiments, the portion where the main body 41 is connected to the bent portion 42 has a third surface 41a facing the electrode assembly 20; the portion where the connecting portion 43 is connected to the bent portion 42 has a fourth surface 43a facing the electrode assembly 20; in the axial direction Y, the distance between the third surface 41a and the fourth surface 43a does not exceed 0.1 mm, but is not limited thereto. The connecting portion 43 and the main body 41 do not occupy too much accommodation space in the housing 10, and the main body 41 of the explosion-proof disc 40 is closer to the end 32, providing a larger accommodation space for the electrode assembly 20 in the housing 10 of the cylindrical battery 100, which is conducive to increasing the volume of the electrode assembly 20 and improving the energy density of the cylindrical battery 100.

[0049] In one or more embodiments, along the direction from the end cap 30 to the electrode assembly 20 , the third surface 41 a extends beyond the fourth surface 43 a .

[0050] In one or more embodiments, along the direction from the end cap 30 to the electrode assembly 20 , the fourth surface 43 a extends beyond the third surface 41 a .

[0051] In one or more embodiments, the CID includes a connecting plate 50 and an insulating member 60, and the bending portion 42 is bent relative to the connecting portion 43 and the main body 41 away from the electrode assembly 20, and a second space K2 is formed on the side of the bending portion 42 facing the electrode assembly 20. The connecting plate 50 is connected to the explosion-proof disc 40. Along the axial direction Y, at least a portion of the insulating member 60 is disposed between the connecting plate 50 and the explosion-proof disc 40, and is located in the second space K2. On the one hand, when the pressure in the shell 10 of the cylindrical battery 100 reaches the second threshold, the explosion-proof disc 40 flips, so that the connecting plate 50 and the explosion-proof disc 40 are disconnected, which is conducive to cutting off the current of the cylindrical battery 100 and improving the safety of the cylindrical battery 100. On the other hand, at least part of the insulating member 60 is arranged between the connecting plate 50 and the explosion-proof plate 40, and is located in the second space K2. In the embodiment of the present scheme, the second space K2 is formed on the side of the bending portion 42 facing the electrode assembly 20, and at least part of the insulating member 60 is arranged in the second space K2. The insulating member 60 does not increase the distance between the connecting plate 50 and the explosion-proof plate 40 along the axial direction Y, which is beneficial to maintain a smaller spacing between the explosion-proof plate 40 and the connecting plate 50 to achieve an insulating connection, reduce the distance between the explosion-proof plate 40 and the connecting plate 50, and thus facilitate the connecting plate 50 to be closer to the end 32. A larger accommodating space is provided for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, which is beneficial to increase the volume of the electrode assembly 20 and improve the energy density of the cylindrical battery 100.

[0052] In one or more embodiments, the housing 10 includes a side wall 11 surrounding the electrode assembly 20, the side wall 11 is provided with a convex portion 111 protruding toward the axis L of the cylindrical battery 100, and a portion of the end cap 30 is located on the side of the convex portion 111 facing away from the electrode assembly 20; along the axial direction Y, the convex portion 111 includes a first proximal end 111a close to the electrode assembly 20, the end portion 32 includes a first distal end 32a away from the electrode assembly 20, along the axial direction Y, the distance between the first proximal end 111a and the first distal end 32a is L1, along the axial direction Y, the connecting plate 50 includes a second proximal end 50a close to the electrode assembly 20, along the axial direction Y, the distance between the second proximal end 50a and the first distal end 32a is L2; ​​60%≤L2 / L1≤80%, but not limited thereto. Optionally, 60%≤L2 / L1≤70%. For example, L2 / L1 can be: 60%, 61%, 62%, 63%, 64%, 65%, 66%, 67%, 68%, 69%, 70%, 71%, 72%, 73%, 74%, 75%, 76%, 77%, 78%, 79%, 80%, or a range consisting of any two values ​​therebetween. Compared with the prior art, L2 / L1 accounts for a smaller proportion. Along the axial direction Y, relative to the first proximal end 111a of the convex portion 111, the connecting plate 50 is conducive to being closer to the first distal end 32a, providing a larger accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, increasing the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0053] The cylindrical battery 100 of the present application is not limited to being a primary battery or a secondary battery. As an example, the cylindrical battery 100 is a lithium-ion secondary battery. In one or more embodiments, the electrode assembly 20 includes a first pole piece, a second pole piece, and a diaphragm. The first pole piece and the second pole piece have opposite polarities, and the diaphragm is disposed between the first pole piece and the second pole piece. During the charge and discharge process of the lithium-ion secondary battery, lithium ions are inserted and removed back and forth between the first pole piece and the second pole piece.

[0054] In one or more embodiments, the first pole piece includes a first body and a first pole ear, and the second pole piece includes a second body and a second pole ear. The first 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 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. The end cap 30 is electrically connected to the first pole ear of the electrode assembly 20, and the end cap 30 forms the first electrode terminal of the cylindrical battery 100. The shell 10 is electrically connected to the second pole ear of the electrode assembly 20, and the shell 10 forms the second electrode terminal of the cylindrical battery 100. One of the first electrode terminal and the second electrode terminal is a positive electrode, and the other is a negative electrode. As a result, the shell 10 replaces one of the traditional electrode terminals, which is conducive to simplifying the structure of the cylindrical battery 100.

[0055] In one or more embodiments, the first pole ear and the second pole ear are both flattened pole ears. Along the axial direction Y, the height of the part where the protrusion 111 presses down the electrode assembly 20 is lower than the height of the central part of the electrode assembly 20, which is beneficial for the protrusion 111 to compact the electrode assembly 20 and improve the position stability of the electrode assembly 20.

[0056] In one or more embodiments, 3.125 mm ≤ L1 ≤ 5.83 mm, but not limited thereto. For example, L1 may be: 3.125 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4.0 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, 5.0 mm, 5.1 mm, 5.2 mm, 5.3 mm, 5.4 mm, 5.5 mm, 5.6 mm, 5.7 mm, 5.8 mm, 5.83 mm, or a range consisting of any two values ​​therebetween. In one or more embodiments, 2.5 mm ≤ L2 ≤ 3.5 mm, but not limited thereto. For example, L2 can be: 2.5mm, 2.55mm, 2.6mm, 2.65mm, 2.7mm, 2.75mm, 2.8mm, 2.85mm, 2.9mm, 2.95mm, 3.0mm, 3.05mm, 3.1mm, 3.15mm, 3.2mm, 3.25mm, 3.3mm, 3.35mm, 3.4mm, 3.45mm, 3.5mm, or a range of any two values ​​therebetween. Compared with the prior art, along the axial direction Y, the distance between the second proximal end 50a and the first distal end 32a is smaller, and relative to the first proximal end 111a of the protrusion 111, the connecting plate 50 is closer to the first distal end 32a, which is conducive to providing a larger accommodating space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, increasing the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0057] In one or more embodiments, the main body 41 includes a central area 411 protruding toward the connecting plate 50, and the central area 411 is welded to the connecting plate 50; along the direction from the end cap 30 to the electrode assembly 20, the distance of the central area 411 beyond the third surface 41a is L3, 0.1mm≤L3≤0.2mm, but not limited thereto. For example, L3 can be: 0.10mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, 0.15mm, 0.16mm, 0.17mm, 0.18mm, 0.19mm, 0.20mm, or a range consisting of any two values ​​therebetween. Compared with the prior art, along the direction of the end cap 30 pointing to the electrode assembly 20, the distance that the central area 411 exceeds the third surface 41a is smaller, which is beneficial to reducing the distance between the third surface 41a of the main body 41 and the connecting plate 50, providing a larger accommodating space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, increasing the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0058] Figure 6 for Figure 1 The connecting plate 50 of the cylindrical battery 100 is shown in FIG. Figure 3 and Figure 6 As shown, in one or more embodiments, the connecting plate 50 includes a fifth surface 50b, the fifth surface 50b is on a side away from the electrode assembly 20, and the fifth surface 50b is a flat surface. The fifth surface 50b being a flat surface means that no concave or convex structure is provided on the fifth surface 50b. Compared with the prior art, the fifth surface 50b of the connecting plate 50 on the side away from the electrode assembly 20 is flat, along the axial direction Y, which is conducive to reducing the spacing between the third surface 41a of the main body 41 and the connecting plate 50, providing a larger accommodating space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, increasing the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0059] Figure 7 for Figure 1 The insulating member 60 of the cylindrical battery 100 is shown in FIG. Figure 3 and Figure 7 As shown, in one or more embodiments, a portion of the insulating member 60 extends to the side of the connecting plate 50 away from the axis L of the cylindrical battery 100. This is beneficial for the insulating member 60 to limit the connecting plate 50 in the radial direction X of the cylindrical battery 100, thereby improving the position stability of the connecting plate 50.

[0060] In a second aspect, the present application provides a battery pack 200, Figure 8 is a schematic diagram of the structure of the battery pack provided in the embodiment of the present application, such as Figure 8As shown, the battery pack 200 includes the cylindrical battery 100 of any of the above embodiments. There is at least one cylindrical battery 100. In one or more embodiments, there are multiple cylindrical batteries 100, and the multiple cylindrical batteries 100 are connected in series or in parallel, or the multiple cylindrical batteries 100 are combined in series and in parallel.

[0061] In a third aspect, the present application provides an electrical device 300, comprising a cylindrical battery 100 or a battery pack 200 according to any of the above embodiments.

[0062] In one or more embodiments, Fig. 9 is a schematic diagram of the structure of the first electrical device provided in the embodiment of the present application, such as Fig. 9 As shown, the electric device 300 includes the battery pack 200 in the above embodiment, and the battery pack 200 includes the cylindrical battery 100 in the above embodiment.

[0063] In one or more embodiments, Fig.10 is a schematic diagram of the structure of a second electrical device provided in an embodiment of the present application, such as Fig.10 As shown, the electric device 300 includes the cylindrical battery 100 in the above embodiment.

[0064] 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 computers, smart phones, backup power supplies, two-wheeled vehicles, drones, power tools or energy storage devices.

[0065] The above description is only a preferred embodiment of the present invention and is not intended to limit the protection scope of the present invention.

Claims

1. A cylindrical battery, characterized in that: include: case; An electrode assembly is disposed in the housing; An end cap is arranged on the housing, and the electrode assembly and the end cap are arranged in sequence along the axial direction of the cylindrical battery. The end cap includes a base and an end portion, and the end portion protrudes from the base along the axial direction. Along the axial direction, the projection of the base surrounds the projection of the end portion; The base comprises a first part and a second part, wherein along the axial direction, a projection of the first part surrounds a projection of the second part, the first part is insulated and connected to the shell, and the second part connects the first part and the end; The first portion includes a first surface facing the electrode assembly, and the second portion includes a second surface facing the electrode assembly, wherein the second surface is closer to the end portion than the first surface along the axial direction.

2. The cylindrical battery according to claim 1, characterized in that: The second portion is bent relative to the first portion and faces away from the electrode assembly, and a first space is formed on a side of the second portion facing the electrode assembly; An explosion-proof plate, a portion of which is disposed in the first space.

3. The cylindrical battery according to claim 2, characterized in that: The explosion-proof plate comprises a main body portion, a bending portion and a connecting portion arranged along the radial direction of the cylindrical battery, and the connecting portion is connected to the first portion; At least a portion of the bent portion is disposed in the first space.

4. The cylindrical battery according to claim 3, characterized in that: The portion of the main body connected to the bent portion has a third surface facing the electrode assembly; The portion where the connecting portion is connected to the bent portion has a fourth surface facing the electrode assembly; In the axial direction, the distance between the third surface and the fourth surface does not exceed 0.1 mm.

5. The cylindrical battery according to claim 3 or 4, characterized in that: The bent portion is bent relative to the connecting portion and the main body portion and is away from the electrode assembly, and a second space is formed on a side of the bent portion facing the electrode assembly; A connecting plate connected to the explosion-proof disk; An insulating member, along the axial direction, at least a portion of the insulating member is disposed between the connecting plate and the explosion-proof disk and is located in the second space.

6. The cylindrical battery according to claim 5, characterized in that: The housing comprises a side wall surrounding the electrode assembly, the side wall is provided with a convex portion protruding toward the axis of the cylindrical battery, and a portion of the end cap is located on a side of the convex portion facing away from the electrode assembly; Along the axial direction, the convex portion includes a first proximal end close to the electrode assembly, and the end portion includes a first distal end away from the electrode assembly, and along the axial direction, a distance between the first proximal end and the first distal end is L1; Along the axial direction, the connecting plate includes a second proximal end close to the electrode assembly, and along the axial direction, a distance between the second proximal end and the first distal end is L2; ​​60%≤L2 / L1≤80%.

7. The cylindrical battery according to claim 6, characterized in that: 60%≤L2 / L1≤70%.

8. The cylindrical battery according to claim 6, characterized in that: 2.5mm≤L2≤3.5mm.

9. The cylindrical battery according to any one of claims 5 to 8, characterized in that: A portion of the insulating member extends to a side of the connecting plate away from an axis of the cylindrical battery.

10. The cylindrical battery according to claim 4, characterized in that: The main body portion includes a central area protruding toward the connecting plate, and the central area is welded to the connecting plate; Along the direction from the end cap to the electrode assembly, the distance that the central area exceeds the third surface is L3, and 0.1 mm≤L3≤0.2 mm.

11. The cylindrical battery according to any one of claims 5 to 10, characterized in that: The connecting plate includes a fifth surface, the fifth surface is away from the electrode assembly, and the fifth surface is a flush surface.

12. A battery pack, characterized in that: A cylindrical battery comprising any one of claims 1 to 11.

13. An electrical device, characterized in that: The invention comprises the cylindrical battery according to any one of claims 1 to 11 or the battery pack according to claim 12.

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