Cylindrical battery, battery pack and electric device

Abstract

Provided in the present application are a cylindrical battery, a battery pack and an electric device. The cylindrical battery comprises a case, an electrode assembly, an end cover and a protective member, wherein a side wall of the case comprises a side wall main body and a bent portion which extends from one end of the side wall main body and bends towards the axis of the cylindrical battery; the electrode assembly and the end cover are arranged in the axial direction of the cylindrical battery, the end cover is connected to the side wall in an insulating manner, and in the axial direction, the bent portion is partially located on the side of the end cover facing away from the electrode assembly; the bent portion comprises an inner surface, an outer surface, and a first end surface which faces the axis, the first end surface connecting the inner surface and the outer surface; and the protective member covers at least the first end surface. The protective member protects the first end surface of the bent portion, making the bent portion of the case of the cylindrical battery less susceptible to corrosion, which is conducive to improving the service durability of the cylindrical battery, the battery pack and the electric device.

Description

Cylindrical battery, battery pack and electric device

[0001] The present application claims priority to the Chinese patent application No. 202411342404.9, filed on September 25, 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, and in particular to a cylindrical battery, a battery pack and an electric device. BACKGROUND

[0003] The shell of the cylindrical battery is usually cut and wound from a steel plate, and the inner and outer surfaces of the steel plate are usually provided with a nickel protective layer, so that the shell has good use durability.

[0004] However, after the steel plate is prepared into the shell, the cutting surface generated during the cutting process is directly exposed to the environment, affecting the use durability 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, so as to improve the use durability of the cylindrical battery.

[0006] The first aspect of the present application provides a cylindrical battery, comprising: a shell, the shell comprising a side wall, the side wall comprising a side wall body and a bent portion, the bent portion extending from one end of the side wall body and bending towards an axis of the cylindrical battery; an electrode assembly arranged in the shell; an end cover, the electrode assembly and the end cover being arranged along an axial direction of the cylindrical battery, the end cover being insulatedly connected with the side wall, and in the axial direction of the cylindrical battery, part of the bent portion is located on a side of the end cover away from the electrode assembly; the bent portion comprises an inner surface, an outer surface and a first end surface facing the axis of the cylindrical battery, the first end surface connecting the inner surface and the outer surface; a protective member covering at least the first end surface. In order to protect the first end surface of the bent portion, the bent portion of the cylindrical battery shell is not easy to be exposed to corrosion, which is conducive to improving the use durability of the cylindrical battery.

[0007] In one or more embodiments, the end cover comprises a base and a protrusion, the base is connected to the side wall in an insulated manner, a portion of the bending part is located on a side of the base away from the electrode assembly in the axial direction of the cylindrical battery, the protrusion extends from the base in the axial direction of the cylindrical battery; the rupture disc comprises a main body and a bending part connected to each other, the main body is arranged on a side of the end cover facing the electrode assembly, the bending part wraps around the peripheral surface of the base in the radial direction of the cylindrical battery, and the bending part covers a portion of the surface of the base on the side away from the electrode assembly, the bending part comprises a second end face facing the axis of the cylindrical battery; the protective member also covers the second end face. In order to protect the second end face of the bending part of the rupture disc, the bending part of the rupture disc of the cylindrical battery shell is not easily exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery.

[0008] In one or more embodiments, the cylindrical battery further comprises a first insulating member, the first insulating member comprises a first part and a second part; the first part is arranged between the side wall and the rupture disc, and the second part is connected to the first part and extends in the opposite direction of the radial direction of the cylindrical battery and beyond the bending part; the protective member also covers the second part. In order to protect the first insulating member, the second part of the first insulating member of the cylindrical battery shell is not easily exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery.

[0009] In one or more embodiments, the base comprises a first surface arranged away from the electrode assembly and not covered by the bending part, and the protective member also covers at least a portion of the first surface. In order to protect the base, the first surface of the base not covered by the bending part is not easily exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery.

[0010] In one or more embodiments, the protective member is a one-piece member. In order to improve the integrity of the protective member, which is conducive to improving the overall strength of the cylindrical battery, and facilitating production and processing.

[0011] In one or more embodiments, the cylindrical battery further comprises a second insulating member, which is arranged on a side of the bending part away from the electrode assembly in the axial direction of the cylindrical battery; in the axial direction of the cylindrical battery, the bending part comprises a top end away from the electrode assembly, and the second insulating member is in contact with the top end. In the process of connecting the end cover of the cylindrical battery with the bus bar, the second insulating member is conducive to forming an insulating isolation between the bus bar and the bending part of the shell, reducing the probability of short circuit of the cylindrical battery caused by electrical connection between the bus bar and the shell. The second insulating member is in contact with the top end, which is conducive to reducing the distance between the second insulating member and the bending part, increasing the size ratio of the electrode assembly in the axial direction of the cylindrical battery, and improving the energy density of the cylindrical battery.

[0012] In one or more embodiments, the bending portion includes a first segment and a second segment, the second segment connecting the first segment and the side wall body, the first segment and the second segment being located on two sides of the top end along the radial direction of the cylindrical battery; a first space is formed between the first segment and the second insulating member, and the protective member is further arranged in the first space to facilitate assembly of the protective member. When the protective member includes an adhesive, the bending portion and the second insulating member can be firmly bonded.

[0013] In one or more embodiments, a second space is formed between the second segment and the second insulating member, and the protective member is further arranged in the second space to facilitate assembly of the protective member. When the protective member includes an adhesive, the bending portion and the second insulating member can be firmly bonded.

[0014] In one or more embodiments, the cylindrical battery further includes an insulating film, the insulating film including a third portion and a fourth portion, the third portion extending along the axial direction and covering at least part of the side wall body, the fourth portion extending along the radial direction of the cylindrical battery and covering at least part of the second insulating member in the axial direction of the cylindrical battery; the third portion, the fourth portion, the bending portion and the second insulating member form a third space; and the protective member is further arranged in the third space to facilitate assembly of the protective member. When the protective member includes an adhesive, the bending portion and the insulating film can be firmly bonded.

[0015] In one or more embodiments, the protective member is attached to the outer surface of the bending portion to facilitate protection of the bending portion. The outer surface of the bending portion of the cylindrical battery shell is not easily exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery. During the connection of the end cover and the bus bar of the cylindrical battery, the protective member facilitates the formation of an insulating isolation between the bus bar and the bending portion of the shell, reducing the probability of short circuit of the cylindrical battery caused by electrical connection between the bus bar and the shell.

[0016] In one or more embodiments, along the axial direction of the cylindrical battery, the bending portion includes a top end away from the electrode assembly, and the thickness of the protective member protruding from the top end is D, 10 μm ≤ D ≤ 150 μm. On the one hand, the protective member forms an insulating isolation between the bus bar and the bending portion of the shell, which is conducive to reducing the risk of short circuit of the cylindrical battery; on the other hand, the thickness of the protective member protruding from the top end is not too thick, which is conducive to increasing the size ratio of the electrode assembly in the axial direction of the cylindrical battery and improving the energy density of the cylindrical battery.

[0017] In one or more embodiments, the protective member includes an adhesive or an insulating paint. The protective member includes an adhesive, which is conducive to bonding the protective member and the surrounding parts, thereby improving the overall strength of the cylindrical battery. The protective member includes an insulating paint to facilitate production and processing and reduce production costs.

[0018] In one or more embodiments, the shell and the end cover have different polarities. The shell serves as the positive electrode or the negative electrode of the cylindrical battery, which is conducive to improving the energy density of the cylindrical battery.

[0019] The second aspect of the present application provides a battery pack comprising the cylindrical battery of any of the above embodiments.

[0020] The third aspect of the present application provides an electric device comprising the cylindrical battery or the battery pack of any of the above embodiments.

[0021] The embodiments of the present application have the following beneficial effects:

[0022] The cylindrical battery, the battery pack and the electric device provided by the embodiments of the present application, the side wall of the cylindrical battery shell comprises a side wall main body and a bending portion, the bending portion extends from one end of the side wall main body and bends towards the axis of the cylindrical battery; the electrode assembly and the end cover are arranged along the axis of the cylindrical battery, the end cover is insulatedly connected with the side wall, in the axis direction of the cylindrical battery, part of the bending portion is located on the side of the end cover away from the electrode assembly; the bending portion comprises an inner surface, an outer surface and a first end surface towards the axis of the cylindrical battery, the first end surface connects the inner surface and the outer surface; the protection member covers at least the first end surface, so as to protect the first end surface of the bending portion, the bending portion of the cylindrical battery shell is not easy to be corroded, which is conducive to improving the use durability of the cylindrical battery, the battery pack and the electric device.

[0023] Of course, implementing any product or method of the present application does not necessarily require achieving all the advantages described above at the same time. BRIEF DESCRIPTION OF DRAWINGS

[0024] 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 embodiments can also be obtained by those skilled in the art based on these drawings.

[0025] FIG. 1 is a schematic structural view of a cylindrical battery of an embodiment of the present application;

[0026] FIG. 2 is a schematic partial cross-sectional structural view of the cylindrical battery shown in FIG. 1;

[0027] FIG. 3 is a schematic partial cross-sectional exploded structural view of the cylindrical battery shown in FIG. 1;

[0028] FIG. 4 is a schematic structural view of a protection member of the cylindrical battery shown in FIG. 1;

[0029] FIG. 5 is a schematic partial cross-sectional structural view of the cylindrical battery shown in FIG. 1, omitting the protection member;

[0030] FIG. 6 is an enlarged view of A in FIG. 5;

[0031] FIG. 7 is a schematic partial cross-sectional structural view of two cylindrical batteries connected by a bus bar according to an embodiment of the present application;

[0032] Fig. 8 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery according to another embodiment of the present application;

[0033] Fig. 9 is an enlarged view of B in Fig. 8;

[0034] Fig. 10 is a schematic diagram of a partial cross-sectional structure of two cylindrical batteries connected by a bus bar according to another embodiment of the present application;

[0035] Fig. 11 is a schematic diagram of a structure of a battery pack according to an embodiment of the present application;

[0036] Fig. 12 is a schematic diagram of a structure of a first power consuming device according to an embodiment of the present application;

[0037] Fig. 13 is a schematic diagram of a structure of a second power consuming device according to an embodiment of the present application.

[0038] The reference signs are as follows: housing 10, side wall 11, side wall body 111, bent portion 112, top end 1121, first section 1122, second section 1123, inner surface 112a, outer surface 112b, first end surface 112c, electrode assembly 20, end cap 30, base 31, circumferential surface 31a, first surface 31b, protrusion 32, protective member 40, rupture disc 50, main body 51, bent back portion 52, second end surface 52a, first insulating member 60, first section 61, second section 62, second insulating member 70, insulating film 80, third section 81, fourth section 82, bus bar 90, cylindrical battery 100, battery pack 200, power consuming device 300, axis L, radial direction X, axial direction Y, first space K1, second space K2, third space K3. DETAILED DESCRIPTION

[0039] 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.

[0040] In the present application, unless specifically defined and limited otherwise, the terms "mounting", "connecting", "connecting", "fixing" and the like should be interpreted broadly, 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 connected 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.

[0041] 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.

[0042] 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.

[0043] In the related art, the cutting surface of the steel plate is exposed to the environment, which may be corroded, reducing the strength of the shell of the cylindrical battery and affecting the use durability of the cylindrical battery.

[0044] The present application provides a cylindrical battery, a battery pack and an electric device, the main purpose of which is to improve the use durability of the cylindrical battery.

[0045] FIG. 1 is a schematic structural diagram 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, 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 of the cylindrical battery 100, and is a direction from the axis L of the cylindrical battery 100 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.

[0046] FIG. 2 is a schematic structural diagram of a partial cross-section of the cylindrical battery shown in FIG. 1, and FIG. 3 is a schematic structural diagram of a partial cross-section of the cylindrical battery shown in FIG. 1. As shown in FIGS. 2 and 3, the cylindrical battery 100 includes a shell 10, an electrode assembly 20, an end cover 30 and a protective member 40.

[0047] The shell 10 comprises a side wall 11, the side wall 11 comprising a side wall body 111 and a bent portion 112, the bent portion 112 extending from one end of the side wall body 111 and bending towards the axis L of the cylindrical battery 100; the electrode assembly 20 is arranged in the shell 10; the electrode assembly 20 and the end cover 30 are arranged along the axial direction Y of the cylindrical battery 100, the end cover 30 is insulatedly connected with the side wall 11, and in the axial direction Y of the cylindrical battery 100, part of the bent portion 112 is located on the side of the end cover 30 away from the electrode assembly 20; the bent portion 112 comprises an inner surface 112a, an outer surface 112b and a first end surface 112c facing the axis L of the cylindrical battery 100, the first end surface 112c connecting the inner surface 112a and the outer surface 112b; the protective piece 40 covers at least the first end surface 112c. The protective piece 40 facilitates protection of the first end surface 112c of the bent portion 112, so that the bent portion 112 of the shell 10 of the cylindrical battery 100 is not easily exposed to corrosion, which is conducive to improving the use durability of the cylindrical battery 100.

[0048] The material of the protective piece 40 is not particularly limited in the present application, and in one or more embodiments, the protective piece 40 comprises an adhesive. The protective piece 40 comprises an adhesive, which on the one hand facilitates firm arrangement of the adhesive on the first end surface 112c, and on the other hand facilitates bonding of the protective piece 40 and the surrounding parts, thereby improving the overall strength of the cylindrical battery 100.

[0049] In one or more embodiments, the adhesive comprises one of polypropylene, polyvinyl chloride and acrylic adhesive, which has good insulation, corrosion resistance and bonding properties, so as to form insulation protection and improve the use durability and overall strength of the cylindrical battery 100.

[0050] For the convenience of illustration, in one or more embodiments, the protective piece 40 is taken as an example to further illustrate the embodiments of the cylindrical battery 100.

[0051] The material of the shell 10 is not particularly limited in the present application, and in one or more embodiments, the material of the shell 10 comprises steel, the shell 10 is a steel shell 10, and the inner and outer surfaces of the steel shell 10 are provided with a nickel protective layer. In the production process of the cylindrical battery 100, the shell 10 of the cylindrical battery 100 can be processed from a steel plate with a nickel protective layer on the inner and outer surfaces. The steel plate is wrapped around the axis L of the cylindrical battery 100 to form a substantially cylindrical shell 10, and the first end surface 112c of the bent portion 112 is a cut surface of the steel plate and does not have a nickel protective layer, which is covered by the adhesive for protection.

[0052] The shape of the protective piece 40 is not particularly limited, and in one or more embodiments, FIG. 4 is a schematic view of a protective piece structure of the cylindrical battery shown in FIG. 1, and in combination with FIGS. 2-4, the first end surface 112c is annular, and the protective piece 40 is annular, and the protective piece 40 covers the first end surface 112c around the axis L of the cylindrical battery 100, so as to form good protection for the annular first end surface 112c.

[0053] FIG. 5 is a schematic view of a partial cross-sectional structure of the cylindrical battery shown in FIG. 1 omitting the protective piece, and FIG. 6 is an enlarged view of A in FIG. 5, and in combination with FIGS. 5 and 6, the structure of the end cover 30 is not particularly limited, and in one or more embodiments, the end cover 30 includes a base body 31 and a protrusion 32, the base body 31 is insulatively connected with the side wall 11, and in the axial direction Y of the cylindrical battery 100, part of the bent portion 112 is located on a side of the base body 31 away from the electrode assembly 20, and the protrusion 32 extends from the base body 31 in the axial direction Y of the cylindrical battery 100; the rupture disc 50 includes a main body portion 51 and a bent portion 52 connected with each other, the main body portion 51 is arranged on a side of the end cover 30 facing the electrode assembly 20, the bent portion 52 wraps around the peripheral surface 31a of the base body 31 in the radial direction X of the cylindrical battery 100, and the bent portion 52 covers part of the surface of the base body 31 on the side away from the electrode assembly 20, and the bent portion 52 includes a second end surface 52a facing the axis L of the cylindrical battery 100; the protective piece 40 also covers the second end surface 52a, so as to form protection for the second end surface 52a of the bent portion 52 of the rupture disc 50, and the second end surface 52a of the rupture disc 50 of the shell 10 of the cylindrical battery 100 is not easily exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery 100.

[0054] The material of the rupture disc 50 is not particularly limited, and in one or more embodiments, the material of the rupture disc 50 includes aluminum, and the rupture disc 50 is an aluminum rupture disc 50, and the second end surface 52a of the bent portion 52 of the aluminum rupture disc 50 facing the axis L is covered by the protective piece 40, so that the second end surface 52a of the aluminum rupture disc 50 is not easily in contact with air to cause corrosion, which is conducive to improving the service durability of the cylindrical battery 100.

[0055] The rupture disc 50 is provided with a valve port, when the cylindrical battery 100 has internal short circuit, and the air pressure in the shell 10 increases to a threshold value, the valve port of the rupture disc 50 is opened, and the high-pressure gas in the shell 10 is released outward through the valve port of the rupture disc 50, thereby reducing the risk of explosion of the cylindrical battery 100.

[0056] In one or more embodiments, the cylindrical battery 100 further comprises a first insulating member 60, the first insulating member 60 comprises a first portion 61 and a second portion 62; the first portion 61 is disposed between the sidewall 11 and the rupture disc 50, and the second portion 62 is connected with the first portion 61 and extends in the opposite direction of the radial direction X of the cylindrical battery 100 and beyond the bending portion 112; the protective member 40 further covers the second portion 62, so as to protect the second portion 62 of the first insulating member 60 from being exposed to the air environment and corroded, which is conducive to improving the service durability of the cylindrical battery 100.

[0057] In one or more embodiments, the first insulating member 60 comprises a rubber ring, so as to form good insulation between the sidewall 11 and the rupture disc 50.

[0058] In one or more embodiments, the base body 31 comprises a first surface 31b, the first surface 31b is disposed away from the electrode assembly 20 and is not covered by the bending portion 52, and the protective member 40 further covers at least part of the first surface 31b, so as to protect the base body 31 from being exposed to corrosion, which is conducive to improving the service durability of the cylindrical battery 100.

[0059] The material of the base body 31 is not particularly limited in the present application, and in one or more embodiments, the material of the base body 31 comprises aluminum, the base body 31 is an aluminum base body 31, and the surface of the aluminum base body 31, which is away from the electrode assembly 20 and is not covered by the bending portion 52, is covered by the protective member 40, so that the surface of the base body 31 covered by the protective member 40 is not easily exposed to the air and corroded, which is conducive to improving the service durability of the cylindrical battery 100.

[0060] In one or more embodiments, the protective member 40 is a one-piece member, so as to improve the integrity of the protective member 40, improve the overall strength of the cylindrical battery 100, and facilitate production and processing.

[0061] In one or more embodiments, a second insulating member 70 is further included, and the second insulating member 70 is disposed on the side of the bending portion 112 away from the electrode assembly 20 along the axial direction Y of the cylindrical battery 100; along the axial direction Y of the cylindrical battery 100, the bending portion 112 comprises a top end 1121 away from the electrode assembly 20, and the second insulating member 70 is in contact with the top end 1121.

[0062] In one or more embodiments, the shell 10 and the end cover 30 have different polarities. The end cover 30 serves as the negative electrode of the cylindrical battery 100, and the shell 10 serves as the positive electrode of the cylindrical battery 100, so that the conventional positive electrode terminal can be omitted, which is conducive to simplifying the structure of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100.

[0063] In one or more embodiments, the end cover 30 serves as the positive electrode of the cylindrical battery 100, and the shell 10 serves as the negative electrode of the cylindrical battery 100, so that the conventional negative electrode terminal can be omitted, which is conducive to simplifying the structure of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100.

[0064] The cylindrical battery 100 of the present application is not limited to a primary battery or a secondary battery. For example, in one or more embodiments, the cylindrical battery is a lithium ion secondary battery, the electrode assembly 20 includes 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 into and extracted from the first electrode sheet and the second electrode sheet.

[0065] In one or more embodiments, the first electrode sheet includes a first body and a first tab, and the second electrode sheet includes a second body and a second tab. 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 tab 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 tab is connected to the second current collector. The end cover 30 is electrically connected to the first tab of the electrode assembly 20, and the end cover 30 forms the 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 the second electrode terminal of the cylindrical battery 100. One of the first electrode terminal and the second electrode terminal is positive, and the other is negative. In this way, the shell 10 replaces the conventional one electrode terminal, which is conducive to simplifying the structure of the cylindrical battery 100.

[0066] FIG. 7 is a schematic view of the partial cross-sectional structure of two cylindrical batteries connected by a bus bar according to an embodiment of the present application. As shown in FIG. 7, in the embodiment in which the two cylindrical batteries 100 are connected by the bus bar 90, the end cover 30 of each of the two cylindrical batteries 100 is connected to the bus bar 90. In the process of connecting the end cover 30 of the cylindrical battery 100 to the bus bar 90, the second insulating member 70 is conducive to forming an insulating isolation between the bus bar 90 and the bent portion 112 of the shell 10, thereby reducing the probability of electrical connection between the bus bar 90 and the shell 10, which may cause short circuit of the cylindrical battery 100. The second insulating member 70 is in contact with the top end 1121, which is conducive to reducing the distance between the second insulating member 70 and the bent portion 112, increasing the size ratio of the electrode assembly 20 in the axial direction Y of the cylindrical battery 100, and improving the energy density of the cylindrical battery 100.

[0067] In combination with FIGS. 5 and 6, in one or more embodiments, the bent portion 112 includes a first segment 1122 and a second segment 1123, the second segment 1123 connecting the first segment 1122 and the side wall body 111, the first segment 1122 and the second segment 1123 being located on both sides of the top end 1121 along the radial direction X of the cylindrical battery 100; a first space K1 is formed between the first segment 1122 and the second insulating member 70, and the protective member 40 is further arranged in the first space K1; the protective member 40 includes an adhesive, the assembly of the adhesive is relatively convenient, and the adhesive can firmly bond the bent portion 112 and the second insulating member 70, thereby improving the positional stability of the second insulating member 70.

[0068] In one or more embodiments, a second space K2 is formed between the second segment 1123 and the second insulating member 70, and the protective member 40 is further arranged in the second space K2. The protective member 40 includes an adhesive, the assembly of the adhesive is relatively convenient, and the adhesive can firmly bond the bent portion 112 and the second insulating member 70, thereby improving the positional stability of the second insulating member 70.

[0069] In one or more embodiments, the insulating film 80 further includes a third portion 81 and a fourth portion 82, the third portion 81 extending along the axial direction Y of the cylindrical battery 100 and covering at least part of the side wall body 111, and the fourth portion 82 extending along the radial direction X of the cylindrical battery 100 and covering at least part of the second insulating member 70 in the axial direction Y; the third portion 81, the fourth portion 82, the bent portion 112 and the second insulating member 70 form a third space K3; the protective member 40 is further arranged in the third space K3, so as to facilitate the assembly of the protective member 40. The protective member 40 includes an adhesive, the adhesive can firmly bond the bent portion 112 and the insulating film 80, thereby improving the positional stability of the insulating film 80.

[0070] In one or more embodiments, the insulating film 80 includes a heat-shrinkable film, and the assembly process of the heat-shrinkable film is relatively convenient, thereby facilitating the assembly of the cylindrical battery 100.

[0071] FIG. 8 is a schematic diagram of a partial cross-sectional structure of a cylindrical battery according to another embodiment of the present application, and FIG. 9 is an enlarged view of B in FIG. 8. As shown in FIGS. 8 and 9, in one or more embodiments, the cylindrical battery 100 is different from the above-described cylindrical battery 100 in that the cylindrical battery 100 does not include the second insulating member 70, and the protective member 40 is attached to the outer surface 112b of the bent portion 112. This is to facilitate the protection of the bent portion 112, and the outer surface 112b of the bent portion 112 of the shell 10 of the cylindrical battery 100 is not easily exposed to corrosion, thereby facilitating the improvement of the use durability of the cylindrical battery 100.

[0072] In one or more embodiments, along the axial direction Y of the cylindrical battery 100, the bending portion 112 includes a top end 1121 away from the electrode assembly 20, and the thickness of the protrusion of the protective piece 40 from the top end 1121 is D, 10 μm≤D≤150 μm, but not limited thereto. For example, D can be: 10 μm, 15 μm, 20 μm, 25 μm, 30 μm, 35 μm, 40 μm, 45 μm, 50 μm, 55 μm, 60 μm, 65 μm, 70 μm, 75 μm, 80 μm, 85 μm, 90 μm, 95 μm, 100 μm, 105 μm, 110 μm, 115 μm, 120 μm, 125 μm, 130 μm, 135 μm, 140 μm, 145 μm, 150 μm, or a range between any two of them. On the one hand, the protective piece 40 forms an insulating isolation between the bus bar 90 and the bending portion 112 of the shell 10, which is conducive to reducing the risk of short circuit of the cylindrical battery 100; on the other hand, the thickness of the protrusion of the protective piece 40 from the top end 1121 is not too thick, which is conducive to increasing the size ratio of the electrode assembly 20 in the axial direction Y of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100.

[0073] FIG. 10 is a schematic diagram of a partial cross-sectional structure of two cylindrical batteries connected by a bus bar according to another embodiment of the present application. As shown in FIG. 10, in the embodiment in which the two cylindrical batteries 100 are connected by the bus bar 90, the end covers 30 of the two cylindrical batteries 100 are connected with the bus bar 90, respectively. In the process of connecting the end covers 30 of the cylindrical batteries 100 with the bus bar 90, the protective piece 40 is conducive to forming an insulating isolation between the bus bar 90 and the bending portion 112 of the shell 10, thereby reducing the risk of electrical connection between the bus bar 90 and the shell 10 and causing short circuit of the cylindrical battery 100.

[0074] In addition to the adhesive, the protective piece 40 can also use insulating paint. In one or more embodiments, the protective piece 40 includes insulating paint to facilitate production and processing and reduce production costs.

[0075] In one or more embodiments, the insulating paint includes at least one of UV (Ultra-Violet Ray, abbreviated as UV) ultraviolet paint, polyurethane, and polysiloxane. The UV ultraviolet paint, polyurethane, and polysiloxane have good insulation and corrosion resistance, which is conducive to forming insulating protection and improving the use durability of the cylindrical battery 100.

[0076] In a second aspect, the application provides a battery pack 200. FIG. 11 is a structural schematic diagram of the battery pack according to an embodiment of the application. As shown in FIG. 11, the battery pack 200 includes the cylindrical battery 100 according to any of the above embodiments. The cylindrical battery 100 is at least one. In one or more embodiments, the cylindrical battery 100 is a plurality, and the plurality of cylindrical batteries 100 are connected in series or in parallel, or a combination of series and parallel connection.

[0077] In a third aspect, the application provides an electric device 300 including the cylindrical battery 100 or the battery pack 200 according to any of the above embodiments.

[0078] In one or more embodiments, FIG. 12 is a structural schematic diagram of a first electric device according to an embodiment of the application. As shown in FIG. 12, the electric device 300 includes the battery pack 200 according to any of the above embodiments, and the battery pack 200 includes the cylindrical battery 100 according to any of the above embodiments.

[0079] In one or more embodiments, FIG. 13 is a structural schematic diagram of a second electric device according to an embodiment of the application. As shown in FIG. 13, the electric device 300 includes the cylindrical battery 100 according to any of the above embodiments.

[0080] The electric device is not particularly limited in the 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.

[0081] The above merely provides the preferred embodiments of the application, but not for limiting the protective scope of the application.

Claims

1. A cylindrical battery, characterized by comprising: The cylindrical battery comprises: a shell comprising a side wall, the side wall comprising a side wall body and a bent portion, the bent portion extending from one end of the side wall body and bending towards an axis of the cylindrical battery; an electrode assembly arranged in the shell; an end cover, the electrode assembly and the end cover being arranged along an axial direction of the cylindrical battery, the end cover being insulatively connected with the side wall, and a portion of the bent portion being located on a side of the end cover away from the electrode assembly along the axial direction of the cylindrical battery; the bent portion comprising an inner surface, an outer surface and a first end surface facing the axis of the cylindrical battery, the first end surface connecting the inner surface and the outer surface; a protective member covering at least the first end surface.

2. The cylindrical battery according to claim 1, characterized by , The end cover comprises a base body and a protrusion, the base body being insulatively connected with the side wall, and a portion of the bent portion being located on a side of the base body away from the electrode assembly along the axial direction of the cylindrical battery, the protrusion extending from the base body along the axial direction of the cylindrical battery; the cylindrical battery further comprises a rupture disc, the rupture disc comprising a main body portion and a bent-back portion connected with each other, the main body portion being arranged on a side of the end cover facing the electrode assembly, the bent-back portion wrapping a peripheral surface of the base body along a radial direction of the cylindrical battery, and the bent-back portion covering a portion of a surface of the base body on a side away from the electrode assembly, the bent-back portion comprising a second end surface facing the axis of the cylindrical battery; the protective member further covers the second end surface.

3. The cylindrical battery according to claim 2, characterized by The cylindrical battery further comprises a first insulating member, the first insulating member comprising a first portion and a second portion; the first portion being arranged between the side wall and the rupture disc, the second portion being connected with the first portion and extending in a direction opposite to the radial direction and beyond the bent portion along the axial direction of the cylindrical battery; the protective member further covers the second portion.

4. The cylindrical battery of claim 3, wherein: the base body comprises a first surface arranged away from the electrode assembly and not covered by the bent-back portion, and the protective member further covers at least a portion of the first surface.

5. The cylindrical battery of any one of claims 2 to 4, wherein: the protective member is a one-piece member.

6. The cylindrical battery according to any one of claims 1 to 5, characterized by, The cylindrical battery further comprises a second insulating member, the second insulating member being arranged on a side of the bent portion away from the electrode assembly along the axial direction of the cylindrical battery; the bent portion comprises a top end away from the electrode assembly along the axial direction of the cylindrical battery, and the second insulating member is in contact with the top end.

7. The cylindrical battery of claim 6, wherein: the bent portion comprises a first segment and a second segment, the second segment connecting the first segment and the side wall body, and the first segment and the second segment being located on two sides of the top end along the radial direction of the cylindrical battery; a first space is formed between the first segment and the second insulating member, and the protective member is further arranged in the first space.

8. The cylindrical battery of claim 7, wherein: a second space is formed between the second segment and the second insulating member, and the protective member is further arranged in the second space.

9. The cylindrical battery according to claim 7, characterized by, The cylindrical battery further comprises an insulating film, the insulating film comprising a third portion and a fourth portion, the third portion extending along an axial direction of the cylindrical battery and covering at least a portion of the side wall body, the fourth portion extending along a radial direction of the cylindrical battery and covering at least a portion of the second insulating member in the axial direction of the cylindrical battery; the third portion, the fourth portion, the bent portion and the second insulating member form a third space; the protective member is further arranged in the third space.

10. The cylindrical battery according to any one of claims 1 to 5, wherein the protective member is attached to an outer surface of the bent portion.

11. The cylindrical battery according to claim 10, wherein in the axial direction of the cylindrical battery, the bent portion comprises a top end away from the electrode assembly, and a thickness of the protective member protruding from the top end is D, 10 pm ≤ D ≤ 150 pm.

12. The cylindrical battery according to any one of claims 1 to 11, wherein the protective member comprises an adhesive or an insulating paint.

13. The cylindrical battery according to any one of claims 1 to 12, wherein the shell and the end cap are of different polarities.

14. A battery pack, characterized by A cylindrical battery comprising any one of the above claims 1 to 13.

15. An electrical device, comprising: A battery pack comprising the cylindrical battery of any one of the above claims 1 to 13 or claim 14.

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