Cylindrical battery, battery pack, and electrical apparatus

Abstract

Provided in the embodiments of the present invention are a cylindrical battery, a battery pack, and an electrical apparatus. The cylindrical battery comprises a casing, an electrode assembly and an end cover. The end cover comprises a base body and an end portion, the base body comprises a first portion and a second portion, and in the axial direction, the projection of the first portion surrounds the projection of the second portion. The first portion is insulatingly connected to the casing, and the second portion is connected to the first portion and the end portion. The first portion has a first surface facing the electrode assembly, the second portion has a second surface facing the electrode assembly, and in the axial direction, the second surface is closer to the end portion than the first surface. The second surface of the second portion is closer to the side of the end portion, which helps to provide a larger accommodation space for the electrode assembly in the casing of the cylindrical battery, thereby increasing the volume of the electrode assembly, and increasing the energy density of the cylindrical battery.

Description

Cylindrical battery, battery pack and electric device

[0001] The present application claims priority to the Chinese patent application No. 202411387992.8, filed on September 30, 2024, and entitled "Cylindrical battery, battery pack and electric device", the content of which is incorporated herein by reference in its entirety. TECHNICAL FIELD

[0002] The present application relates to the technical field of energy storage, in particular to a cylindrical battery, a battery pack and an electric device. BACKGROUND

[0003] The cylindrical battery is usually provided with a CID (current interrupt device, CID for short) inside, the CID is electrically connected with the end cover, and when an abnormality occurs in the cylindrical battery, the CID can cut off the current inside the cylindrical battery, so as to improve the safety of the cylindrical battery.

[0004] Among them, the end cover and the CID of the conventional structure limit the space available to the electrode assembly, which is not conducive to the improvement of the energy density of the cylindrical battery. SUMMARY

[0005] The purpose of the embodiments of the present application is to provide a cylindrical battery, a battery pack and an electric device, which are conducive to improving the energy density of the cylindrical battery.

[0006] The first aspect of the present application provides a cylindrical battery, comprising: a shell; an electrode assembly arranged in the shell; an end cover arranged in the shell along the axial direction of the cylindrical battery, the electrode assembly and the end cover being arranged in sequence, the end cover comprising a base body and an end portion, the end portion protruding from the base body along the axial direction of the cylindrical battery, and the projection of the base body surrounding the projection of the end portion along the axial direction of the cylindrical battery; the base body comprising a first part and a second part, the projection of the first part surrounding the projection of the second part along the axial direction of the cylindrical battery, the first part being insulatively connected to the shell, and the second part connecting the first part and the end portion; the first part comprising a first surface facing the electrode assembly, and the second part comprising a second surface facing the electrode assembly, the second surface being closer to the end portion than the first surface along the axial direction of the cylindrical battery. The second surface of the second part is closer to the end portion, so as to provide a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, facilitate the increase of the volume of the electrode assembly, and improve the energy density of the cylindrical battery.

[0007] In one or more embodiments, the second portion is bent away from the electrode assembly relative to the first portion, and forms a first space on a side of the second portion facing the electrode assembly; the cylindrical battery further comprises a rupture disc, a portion of the rupture disc is disposed in the first space. In one aspect, when the pressure in the cylindrical battery housing reaches a first threshold, a valve port of the rupture disc opens, facilitating pressure relief of the cylindrical battery. In another aspect, the second portion is bent away from the electrode assembly relative to the first portion to form the first space, and a portion of the rupture disc is disposed in the first space, thereby facilitating the rupture disc being closer to the end portion, providing more accommodation space for the electrode assembly in the housing of the cylindrical battery, facilitating increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0008] In one or more embodiments, the rupture disc comprises a main body portion, a bent portion, and a connecting portion arranged along the radial direction of the cylindrical battery, the connecting portion is connected with the first portion; at least a portion of the bent portion is disposed in the first space. Thereby, the rupture disc is closer to the end portion, providing more accommodation space for the electrode assembly in the housing of the cylindrical battery, facilitating increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0009] In one or more embodiments, the portion of the main body portion connected with the bent portion has a third surface facing the electrode assembly; the portion of the connecting portion connected with the bent portion has a fourth surface facing the electrode assembly; the distance between the third surface and the fourth surface in the axial direction of the cylindrical battery is not more than 0.1 mm. The connecting portion and the main body portion do not excessively occupy the accommodation space in the housing, the main body portion of the rupture disc is closer to the end portion, providing more accommodation space for the electrode assembly in the housing of the cylindrical battery, facilitating increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0010] In one or more embodiments, the bent portion is bent away from the electrode assembly relative to the connecting portion and the main body portion, and forms a second space on a side of the bent portion facing the electrode assembly; the cylindrical battery further comprises a connecting plate and an insulating piece; the connecting plate is connected with the rupture disc; the insulating piece is disposed between the connecting plate and the rupture disc in the axial direction of the cylindrical battery, and located in the second space. In one aspect, when the pressure in the cylindrical battery housing reaches a second threshold, the rupture disc flips over, such that the connecting plate and the rupture disc are disconnected, facilitating cutting off the current of the cylindrical battery, and improving the safety of the cylindrical battery. In another aspect, the insulating piece is disposed between the connecting plate and the rupture disc, and located in the second space, the insulating piece does not increase the distance between the connecting plate and the rupture disc in the axial direction, thereby facilitating the connecting plate being closer to the end portion, providing more accommodation space for the electrode assembly in the housing of the cylindrical battery, facilitating increasing the volume of the electrode assembly, and improving the energy density of the cylindrical battery.

[0011] In one or more embodiments, the shell comprises a side wall surrounding the electrode assembly, the side wall is provided with a protrusion protruding towards the axis of the cylindrical battery, a portion of the end cover is located on a side of the protrusion away from the electrode assembly; along the axial direction of the cylindrical battery, the protrusion comprises a first proximal end close to the electrode assembly, the end portion comprises a first distal end away from the electrode assembly, the distance between the first proximal end and the first distal end along the axial direction of the cylindrical battery is L1, the connecting plate comprises a second proximal end close to the electrode assembly along the axial direction of the cylindrical battery, the distance between the second proximal end and the first distal end along the axial direction of the cylindrical battery is L2; 60%≤L2 / L1≤80%. The connecting plate is closer to the first distal end relative to the first proximal end of the protrusion along the axial direction of the cylindrical battery, which provides a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, increases the volume of the electrode assembly, and improves the energy density of the cylindrical battery.

[0012] In one or more embodiments, 60%≤L2 / L1≤70%. The connecting plate is closer to the first distal end relative to the first proximal end of the protrusion along the axial direction of the cylindrical battery, which provides a larger accommodation space for the electrode assembly in the shell of the cylindrical battery, increases the volume of the electrode assembly, and improves the energy density of the cylindrical battery.

[0013] In one or more embodiments, 2.5mm≤L2≤3.5mm. The distance between the second proximal end and the first distal end along the axial direction of the cylindrical battery is small, and the connecting plate is closer to the first distal end relative to the first proximal end of the protrusion, which is conducive to 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.

[0014] In one or more embodiments, a portion of the insulating piece extends to a side of the connecting plate away from the axis of the cylindrical battery. The insulating piece is conducive to limiting the position of the connecting plate in the radial direction of the cylindrical battery, improving the position stability of the connecting plate.

[0015] In one or more embodiments, the main body portion comprises a central region protruding towards the connecting plate, and the central region and the connecting plate are welded; the portion of the main body portion connected with the bent portion has a third surface facing the electrode assembly, and the distance between the central region and the third surface in the direction of the end cover facing the electrode assembly is L3, 0.1mm≤L3≤0.2mm. The distance between the central region and the third surface in the direction of the end cover facing the electrode assembly is small, which is conducive to reducing the distance between the third surface of the main body portion 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.

[0016] In one or more embodiments, the connecting plate comprises a fifth surface, the fifth surface being away from the side of the electrode assembly, the fifth surface being a flush surface. The fifth surface of the connecting plate away from the side of the electrode assembly is flush along the axial direction of the cylindrical battery, 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.

[0017] The second aspect of the present application provides a battery pack comprising the cylindrical battery of any of the above embodiments.

[0018] The third aspect of the present application provides a power consumption device comprising the cylindrical battery or the battery pack of any of the above embodiments.

[0019] The embodiments of the present application have the following beneficial effects:

[0020] The cylindrical battery, the battery pack and the power consumption device provided by the embodiments of the present application, the cylindrical battery comprises a shell, an electrode assembly and an end cover. The end cover comprises a base and an end portion, the end portion protrudes from the base along the axial direction of the cylindrical battery, and the projection of the base surrounds the projection of the end portion along the axial direction of the cylindrical battery. The base comprises a first portion and a second portion, and the projection of the first portion surrounds the projection of the second portion along the axial direction of the cylindrical battery. The first portion is insulatedly connected to the shell, and the second portion connects the first portion and the end portion. The first portion comprises a first surface facing the electrode assembly, and the second portion comprises a second surface facing the electrode assembly, and the second surface is closer to the end portion than the first surface along the axial direction of the cylindrical battery. The second surface of the second portion is closer to the end portion, which is conducive to 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. Of course, any product implementing the present application does not necessarily need to achieve all the advantages described above. BRIEF DESCRIPTION OF DRAWINGS

[0021] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings needed to be used in the embodiments or prior art description. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can also be obtained by those skilled in the art based on these drawings.

[0022] FIG. 1 is a schematic structural view of a cylindrical battery according to an embodiment of the present application;

[0023] FIG. 2 is a schematic structural view of a partial cross-section of the cylindrical battery shown in FIG. 1;

[0024] FIG. 3 is an enlarged view of A in FIG. 2;

[0025] FIG. 4 is a schematic structural view of an end cover of the cylindrical battery shown in FIG. 1;

[0026] Fig. 5 is a schematic diagram of an explosion-proof sheet structure of the cylindrical battery shown in Fig. 1;

[0027] Fig. 6 is a schematic diagram of a connecting plate structure of the cylindrical battery shown in Fig. 1;

[0028] Fig. 7 is a schematic diagram of an insulating piece structure of the cylindrical battery shown in Fig. 1;

[0029] Fig. 8 is a schematic diagram of a battery pack structure according to an embodiment of the present application;

[0030] Fig. 9 is a schematic diagram of a first power consuming device structure according to an embodiment of the present application;

[0031] Fig. 10 is a schematic diagram of a second power consuming device structure according to an embodiment of the present application.

[0032] The reference signs are as follows: shell 10, side wall 11, protruding part 111, first proximal end 111a, electrode assembly 20, end cap 30, base 31, first part 311, first surface 311a, second part 312, second surface 312a, end part 32, first distal end 32a, explosion-proof sheet 40, main body 41, central area 411, third surface 41a, bent part 42, connecting part 43, fourth surface 43a, connecting plate 50, second proximal end 50a, fifth surface 50b, insulating piece 60; cylindrical battery 100, battery pack 200, power consuming device 300; radial direction X, axial direction Y, first space K1, second space K2, axis L. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, but not all of the embodiments of the present application.

[0034] In the present application, unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, can be fixedly connected, can be detachably connected, or integrally connected; can be mechanically connected, or electrically connected; can be directly connected, or indirectly connected through an intermediate medium, or can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present 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.

[0035] 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 "a plurality of" is two or more, unless otherwise explicitly specified.

[0036] Reference to "embodiments" herein means that the specific features, structures or properties described in connection with the embodiments can be included in at least one embodiment of the present application. The phrase appears at various places in the specification does not necessarily all refer to the same embodiments, nor is it necessarily independent or alternative embodiments to other embodiments. In the case of no conflict, each embodiment in the present application can be combined with each other.

[0037] In the related art, the base body of the cylindrical battery end cover is a ring-shaped flat plate as a whole, which is easy to limit the space for accommodating the electrode assembly inside the cylindrical battery, and affects the energy density of the cylindrical battery.

[0038] The present application provides a cylindrical battery, a battery pack and an electric device, the main purpose of which is to improve the energy density of the cylindrical battery.

[0039] FIG. 1 is a schematic structural view of a cylindrical battery according to an embodiment of the present application. As shown in FIG. 1, in a first aspect, the present application provides a cylindrical battery 100, which can be a nickel-hydrogen battery, a nickel-cadmium battery, a lead-acid (or lead-acid) 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, which is in a plane perpendicular to the axis L, and X is a direction from the axis L to the outside of the cylindrical battery 100. The axial direction of the cylindrical battery 100 is Y, which is parallel to the axis L of the cylindrical battery 100.

[0040] FIG. 2 is a schematic structural view of a partial cross-section of the cylindrical battery shown in FIG. 1. As shown in FIGS. 1 and 2, the first aspect of the present application provides a cylindrical battery 100, which includes a shell 10, an electrode assembly 20 and an end cover 30.

[0041] The electrode assembly 20 is arranged in the shell 10. The shell 10 has an opening (not shown) at one end, and the end cover 30 is arranged on the shell 10 and covers the opening. Along the axial direction Y of the cylindrical battery 100, the electrode assembly 20 and the end cover 30 are arranged in sequence, and the end cover 30 includes a base body 31 and an end portion 32, the end portion 32 protrudes from the base body 31 along the axial direction Y of the cylindrical battery 100, and the projection of the base body 31 surrounds the projection of the end portion 32 along the axial direction Y of the cylindrical battery 100. The base body 31 includes a first portion 311 and a second portion 312, the projection of the first portion 311 surrounds the projection of the second portion 312 along the axial direction Y of the cylindrical battery 100, the first portion 311 is insulatively connected to the shell 10, and the second portion 312 connects the first portion 311 and the end portion 32. The first portion 311 includes a first surface 311a facing the electrode assembly 20, the second portion 312 includes a second surface 312a facing the electrode assembly 20, and the second surface 312a is closer to the end portion 32 than the first surface 311a along the axial direction Y of the cylindrical battery 100.

[0042] The cylindrical battery 100 provided by the embodiment of the present application has the second surface 312a of the second portion 312 closer to the end portion 32, thereby facilitating to provide a larger accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, facilitating to increase the volume of the electrode assembly 20 and improve the energy density of the cylindrical battery 100.

[0043] In one or more embodiments, the cylindrical battery 100 further includes a CID, the CID is electrically connected to the electrode assembly 20 and the end cover 30, and the CID includes the rupture disc 40. FIG. 3 is an enlarged view of A in FIG. 2, and FIG. 4 is a structural schematic view of the end cover 30 of the cylindrical battery 100 shown in FIG. 1. As shown in FIGS. 3 and 4, in one or more embodiments, the second portion 312 is bent away from the electrode assembly 20 relative to the first portion 311, and a first space K1 is formed on the side of the second portion 312 facing the electrode assembly 20. A part of the rupture disc 40 is arranged in the first space K1.

[0044] The explosion-proof sheet 40 has a valve port, when the cylindrical battery 100 fails and the internal gas pressure reaches a first threshold value, the valve port of the explosion-proof sheet 40 is opened, and the high-pressure gas in the shell 10 is released outward through the valve port of the explosion-proof sheet 40, which is beneficial to the pressure relief of the cylindrical battery 100 and improves the safety of the cylindrical battery 100. On the other hand, the second part 312 is bent relative to the first part 311 to form a first space K1, and a part of the explosion-proof sheet 40 is arranged in the first space K1. In the embodiment of the present scheme, the second part 312 of the end cover 30 is changed from a conventional flat structure to a bent structure protruding upward (along the axial direction Y of the cylindrical battery 100), which drives the explosion-proof sheet 40 to protrude upward (along the axial direction Y of the cylindrical battery 100) as well, reduces the distance between the explosion-proof sheet 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 providing a longer accommodation space in the axial direction Y of the cylindrical battery 100 for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, and is beneficial to increasing the volume of the electrode assembly 20 and improving the energy density of the cylindrical battery 100.

[0045] FIG. 5 is a schematic view of the structure of the explosion-proof sheet 40 of the cylindrical battery 100 shown in FIG. 1. As shown in FIGS. 3 and 5, in one or more embodiments, the explosion-proof sheet 40 includes a main body part 41, a bent part 42, and a connecting part 43 arranged along the radial direction X of the cylindrical battery 100, the connecting part 43 is connected with the first part 311, and at least part of the bent part 42 is arranged in the first space K1. Thus, the explosion-proof sheet 40 is more close to the end part 32, which is beneficial to providing a larger accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, and is beneficial to increasing the volume of the electrode assembly 20 and improving the energy density of the cylindrical battery 100.

[0046] In one or more embodiments, the part where the main body part 41 is connected with the bent part 42 has a third surface 41a facing the electrode assembly 20, and the part where the connecting part 43 is connected with the bent part 42 has a fourth surface 43a facing the electrode assembly 20, and the distance between the third surface 41a and the fourth surface 43a in the axial direction Y of the cylindrical battery 100 is not more than 0.1 mm, but is not limited thereto. The connecting part 43 and the main body part 41 do not occupy too much accommodation space in the shell 10, the main body part 41 of the explosion-proof sheet 40 is more close to the end part 32, which is beneficial to providing a larger accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, and is beneficial to increasing the volume of the electrode assembly 20 and improving the energy density of the cylindrical battery 100.

[0047] In one or more embodiments, along the direction of the end cover 30 pointing to the electrode assembly 20, the third surface 41a exceeds the fourth surface 43a.

[0048] In one or more embodiments, along the direction of the end cover 30 pointing to the electrode assembly 20, the fourth surface 43a exceeds the third surface 41a.

[0049] In one or more embodiments, the CID comprises the connecting plate 50 and the insulation piece 60, the bending portion 42 is bent away from the electrode assembly 20 relative to the connecting portion 43 and the main body portion 41, 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 rupture disc 40. At least part of the insulation piece 60 is arranged between the connecting plate 50 and the rupture disc 40 and located in the second space K2 along the axial direction Y of the cylindrical battery 100. On the one hand, when the pressure in the shell 10 of the cylindrical battery 100 reaches the second threshold value, the rupture disc 40 is turned over, so that the connecting plate 50 and the rupture 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 insulation piece 60 is arranged between the connecting plate 50 and the rupture disc 40 and 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 insulation piece 60 is arranged in the second space K2. The insulation piece 60 does not increase the distance between the connecting plate 50 and the rupture disc 40 along the axial direction Y of the cylindrical battery 100, which is conducive to maintaining a small distance between the rupture disc 40 and the connecting plate 50 to achieve insulation connection, reducing the distance between the rupture disc 40 and the connecting plate 50, so as to facilitate the connecting plate 50 to be closer to the side of the end portion 32, thereby providing a larger accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, facilitating to increase the volume of the electrode assembly 20, and improving the energy density of the cylindrical battery 100.

[0050] In one or more embodiments, the shell 10 comprises a side wall 11 surrounding the electrode assembly 20, the side wall 11 is provided with a protrusion 111 protruding towards the axis L of the cylindrical battery 100, a portion of the end cover 30 is located on the side of the protrusion 111 away from the electrode assembly 20; along the axial direction Y of the cylindrical battery 100, the protrusion 111 comprises a first proximal end 111a close to the electrode assembly 20, the end portion 32 comprises a first distal end 32a away from the electrode assembly 20, along the axial direction Y of the cylindrical battery 100, the distance between the first proximal end 111a and the first distal end 32a is L1, along the axial direction Y of the cylindrical battery 100, the connecting plate 50 comprises 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 between any two of them. Compared with the prior art, the L2 / L1 ratio is small, along the axial direction Y of the cylindrical battery 100, the connecting plate 50 is beneficial to be closer to the first distal end 32a relative to the first proximal end 111a of the protrusion 111, 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.

[0051] The cylindrical battery 100 of the present application is not limited to be a primary battery or a secondary battery. For example, taking the cylindrical battery 100 as a lithium ion secondary battery in one or more embodiments, the electrode assembly 20 comprises a first electrode sheet, a second electrode sheet and a separator, the first electrode sheet and the second electrode sheet are opposite in polarity, and the separator is arranged between the first electrode sheet and the second electrode sheet. In the charging and discharging process of the lithium ion secondary battery, lithium ions are inserted and extracted between the first electrode sheet and the second electrode sheet.

[0052] In one or more embodiments, the first tab includes a first body and a first tab, and the second tab includes a second body and a second tab. The first body includes a first current collector and a first active material layer coated on a surface of the first current collector, and the first tab is connected to the first current collector. The second body includes a second current collector and a second active material layer coated on a surface of the second current collector, and the second tab is connected to the second current collector. The end cap 30 is electrically connected to the first tab of the electrode assembly 20, and the end cap 30 forms a first electrode terminal of the cylindrical battery 100. The shell 10 is electrically connected to the second tab of the electrode assembly 20, and the shell 10 forms a 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. Thus, the shell 10 replaces a conventional one electrode terminal, which is advantageous to simplify the structure of the cylindrical battery 100.

[0053] In one or more embodiments, the first tab and the second tab are both flat tabs, and along the axial direction Y of the cylindrical battery 100, the height of the portion of the electrode assembly 20 pressed by the convex portion 111 is lower than the height of the central portion of the electrode assembly 20, which is advantageous to compact the electrode assembly 20 by the convex portion 111 and improve the positional stability of the electrode assembly 20.

[0054] In one or more embodiments, 3.125 mm≤L1≤5.83 mm, but not limited thereto. For example, L1 can 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 between any two of the values. In one or more embodiments, 2.5 mm≤L2≤3.5 mm, but not limited thereto. For example, L2 can be: 2.5 mm, 2.55 mm, 2.6 mm, 2.65 mm, 2.7 mm, 2.75 mm, 2.8 mm, 2.85 mm, 2.9 mm, 2.95 mm, 3.0 mm, 3.05 mm, 3.1 mm, 3.15 mm, 3.2 mm, 3.25 mm, 3.3 mm, 3.35 mm, 3.4 mm, 3.45 mm, 3.5 mm, or a range between any two of the values. Compared with the prior art, the distance between the second proximal end 50a and the first distal end 32a along the axial direction Y of the cylindrical battery 100 is small, and the connecting plate 50 is closer to the first distal end 32a relative to the first proximal end 111a of the convex portion 111, which is conducive to 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.

[0055] In one or more embodiments, the main body portion 41 includes a central region 411 protruding towards the connecting plate 50, and the central region 411 and the connecting plate 50 are welded; in the direction of the end cover 30 pointing to the electrode assembly 20, the distance of the central region 411 beyond the third surface 41a is L3, and 0.1 mm≤L3≤0.2 mm, but not limited thereto. For example, L3 can be: 0.10 mm, 0.11 mm, 0.12 mm, 0.13 mm, 0.14 mm, 0.15 mm, 0.16 mm, 0.17 mm, 0.18 mm, 0.19 mm, 0.20 mm, or a range between any two of the values. Compared with the prior art, the distance of the central region 411 beyond the third surface 41a in the direction of the end cover 30 pointing to the electrode assembly 20 is small, which is conducive to reducing the distance between the third surface 41a of the main body portion 41 and the connecting plate 50, 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.

[0056] Figure 6 is a schematic diagram of the structure of the connecting plate 50 of the cylindrical battery 100 shown in Figure 1. As shown in Figures 3 and 6, in one or more embodiments, the connecting plate 50 includes a fifth surface 50b, which is away from the side of the electrode assembly 20, and the fifth surface 50b is a flush surface. Among them, the fifth surface 50b is a flush surface, which means that the fifth surface 50b is not provided with concave and convex structures. Compared with the prior art, the fifth surface 50b of the connecting plate 50 away from the electrode assembly 20 is flush, along the axial direction Y of the cylindrical battery 100, which is beneficial to reduce the spacing between the third surface 41a of the main body 41 and the connecting plate 50, provide more accommodation space for the electrode assembly 20 in the shell 10 of the cylindrical battery 100, increase the volume of the electrode assembly 20, and improve the energy density of the cylindrical battery 100.

[0057] Figure 7 is a schematic diagram of the structure of the insulating piece 60 of the cylindrical battery 100 shown in Figure 1. As shown in Figures 3 and 7, in one or more embodiments, a part of the insulating piece 60 extends to the side of the connecting plate 50 away from the axis L of the cylindrical battery 100. This is beneficial to limit the position of the connecting plate 50 in the radial direction X of the cylindrical battery 100 by the insulating piece 60, and improve the position stability of the connecting plate 50.

[0058] 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 according to an embodiment of the present application. As shown in Figure 8, 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, which are connected in series or in parallel, or a combination of series and parallel connection.

[0059] In a third aspect, the present application provides an electric device 300, which includes the cylindrical battery 100 or the battery pack 200 of any of the above embodiments.

[0060] In one or more embodiments, Figure 9 is a schematic diagram of the structure of a first electric device according to an embodiment of the present application. As shown in Figure 9, the electric device 300 includes the battery pack 200 of the above embodiments, and the battery pack 200 includes the cylindrical battery 100 of the above embodiments.

[0061] In one or more embodiments, Figure 10 is a schematic diagram of the structure of a second electric device according to an embodiment of the present application. As shown in Figure 10, the electric device 300 includes the cylindrical battery 100 of the above embodiments.

[0062] The electric device is not particularly limited in the present application, and includes the electric device known in the prior art. For example, the electric device includes but is not limited to a computer, a smart phone, a backup power supply, a two-wheeled vehicle, a drone, a power tool, or an energy storage device, etc.

[0063] The above description is only the preferred embodiment of the application, not intended to limit the protection scope of the application.

Claims

1. A cylindrical battery, characterized by comprising: The cylindrical battery comprises: a shell; an electrode assembly arranged in the shell; an end cover arranged in the shell along an axial direction of the cylindrical battery, the electrode assembly and the end cover being arranged in sequence, the end cover comprising a base and an end portion, the end portion protruding from the base along the axial direction of the cylindrical battery, a projection of the base along the axial direction of the cylindrical battery surrounding a projection of the end portion; the base comprising a first portion and a second portion, a projection of the first portion along the axial direction of the cylindrical battery surrounding a projection of the second portion, the first portion being insulatively connected to the shell, the second portion connecting the first portion and the end portion; the first portion comprising a first surface facing the electrode assembly, the second portion comprising a second surface facing the electrode assembly, the second surface being closer to the end portion than the first surface along the axial direction of the cylindrical battery.

2. The cylindrical battery of claim 1, wherein: the second portion is bent away from the electrode assembly relative to the first portion, and a first space is formed on a side of the second portion facing the electrode assembly; the cylindrical battery further comprises a rupture disc, a portion of the rupture disc being arranged in the first space.

3. The cylindrical battery of claim 2, wherein: the rupture disc comprises a main body portion, a bent portion and a connecting portion arranged along a radial direction of the cylindrical battery, the connecting portion being connected to the first portion; at least a portion of the bent portion is arranged in the first space.

4. The cylindrical battery of claim 3, wherein: a portion of the main body portion connected to the bent portion has a third surface facing the electrode assembly; a portion of the connecting portion connected to the bent portion has a fourth surface facing the electrode assembly; a distance between the third surface and the fourth surface along the axial direction is not more than 0.1 mm.

5. The cylindrical battery of claim 3 or 4, wherein: the bent portion is bent away from the electrode assembly relative to the connecting portion and the main body portion, and a second space is formed on a side of the bent portion facing the electrode assembly; the cylindrical battery further comprises a connecting plate and an insulating member; the connecting plate is connected to the rupture disc; at least a portion of the insulating member is arranged between the connecting plate and the rupture disc along the axial direction of the cylindrical battery, and is located in the second space.

6. The cylindrical battery of claim 5, wherein: the shell comprises a side wall surrounding the electrode assembly, the side wall being provided with a protrusion protruding towards an axial line of the cylindrical battery, a portion of the end cover being located on a side of the protrusion away from the electrode assembly; the protrusion comprises a first proximal end close to the electrode assembly along the axial direction of the cylindrical battery, the end portion comprises a first distal end away from the electrode assembly along the axial direction of the cylindrical battery, a distance between the first proximal end and the first distal end along the axial direction of the cylindrical battery being L1. In the axial direction of the cylindrical battery, the connecting plate includes a second proximal end close to the electrode assembly, and a distance between the second proximal end and the first distal end in the axial direction of the cylindrical battery is L2; 60%≤L2 / L1≤80%. 7.The cylindrical battery of claim 6, wherein, 60%≤L2 / L1≤70%. 8.The cylindrical battery of claim 6, wherein, 2.5mm≤L2≤3.5mm. 9.The cylindrical battery of any one of claims 5 to 8, wherein, a portion of the insulating member extends to a side of the connecting plate away from the axis of the cylindrical battery. 10.The cylindrical battery of claim 5, wherein, the main body portion includes a central region protruding toward the connecting plate, and the central region and the connecting plate are welded; a portion of the main body portion connected to the bent portion has a third surface facing the electrode assembly, and a distance between the central region and the third surface in a direction of the end cover pointing to the electrode assembly is L3, 0.1mm≤L3≤0.2mm. 11.The cylindrical battery of any one of claims 5 to 10, wherein, the connecting plate includes a fifth surface on a side away from the electrode assembly, and the fifth surface is a flush surface.

12. A battery pack, characterized by A battery pack including the cylindrical battery of any one of claims 1 to 11.

13. An electrical device, characterized by A battery pack including the cylindrical battery of any one of claims 1 to 11 or the battery pack of claim 12.

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