Cylindrical battery, battery module and electric equipment

Abstract

The invention discloses a cylindrical battery, a battery module and electric equipment. A cylindrical battery includes a housing, an electrode assembly, a collector plate, and an insulator. The housing includes an electrode lead-out portion. The electrode assembly is accommodated in the shell, and the electrode assembly and the electrode leading-out part are arranged along the axial direction of the cylindrical battery. The collector plate comprises a first part, a second part and a bending part, the first part is connected to the electrode leading-out part, the second part is connected to the electrode assembly, the first part and the second part are arranged at an interval along the axial direction of the cylindrical battery, and the bending part is connected with the first part and the second part. The bending part comprises a thinning part, the thickness of the thinning part is smaller than that of the first part, and the thickness of the thinning part is smaller than that of the second part. In the axial direction, at least part of the insulating part is arranged between the first part and the second part.

Description

Technical Field

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

[0002] With the rapid development of the battery industry, the application of batteries in electric vehicles, electric bicycles, electric tools and other fields has become a trend. Cylindrical batteries are favored due to their advantages such as good grouping and high stability, and are gradually used in various complex scenarios.

[0003] How to simplify the safety of cylindrical batteries has always been a research direction in the industry. Summary of the invention

[0004] The present application provides a cylindrical battery, a battery module and an electrical device, which can reduce the risk of fire and explosion and improve safety.

[0005] In a first aspect, the present application provides a cylindrical battery, which includes a shell, an electrode assembly, a current collector and an insulating member. The shell includes an electrode lead-out portion. The electrode assembly is accommodated in the shell, and the electrode assembly and the electrode lead-out portion are arranged along the axial direction of the cylindrical battery. The current collector includes a first part, a second part and a bending portion, the first part is connected to the electrode lead-out portion, the second part is connected to the electrode assembly, the first part and the second part are arranged at intervals along the axial direction of the cylindrical battery, and the bending portion connects the first part and the second part. The bending portion includes a thinning portion, the thickness of the thinning portion is less than the thickness of the first part, and the thickness of the thinning portion is less than the thickness of the second part. In the axial direction, at least part of the insulating member is arranged between the first part and the second part.

[0006] When the current of a cylindrical battery increases sharply due to an accident (such as an external short circuit), the thinning portion can generate heat and melt under the action of the current, thereby cutting off the circuit in time, slowing down the reaction of the cylindrical battery, and reducing the risk of fire and explosion of the cylindrical battery. When the thinning portion melts, the connection between the first part and the second part is disconnected. The insulating member can separate the first part from the second part, reducing the risk of contact and conduction between the first part and the second part. When the cylindrical battery is subjected to external impact, the insulating member can limit the axial movement of the second part, thereby reducing the risk of the residual part of the bent portion being overlapped again, so that the circuit of the cylindrical battery remains cut off, reducing the risk of fire and explosion of the cylindrical battery.

[0007] In one or more of the above optional embodiments, the insulating member and the thinning portion are spaced apart along the radial direction of the cylindrical battery. The embodiment of the present application can reduce the heat conducted to the insulating member when the thinning portion is melted, reduce the risk of melting and deformation of the insulating member at high temperature, improve the insulation effect, and improve the safety performance.

[0008] In one or more optional embodiments above, the insulating member has a first surface and a second surface arranged opposite to each other in the axial direction, the first surface contacts the first part, and the second surface contacts the second part. When the cylindrical battery is subjected to external impact, the insulating member can limit the movement of the second part toward the first part, thereby reducing the risk of the residual part of the bent part being fused and then overlapping again, thereby improving safety performance.

[0009] In one or more optional embodiments above, at least one of the first part and the second part is fixed to the insulating member. When the cylindrical battery is subjected to external impact, the first part or the second part can constrain the insulating member, limit the movement of the insulating member in the radial direction of the cylindrical battery, and improve the insulation effect.

[0010] In one or more optional embodiments above, the melting point of the insulating member is greater than or equal to 500° C. The insulating member has a high melting point, and when the current of the cylindrical battery increases sharply due to an accident, the insulating member is not easily melted under the high temperature of the current collecting plate, thereby effectively supporting and isolating the first part and the second part, reducing the risk of the circuit being turned on again after the thinning part is melted, and improving safety performance.

[0011] In one or more optional embodiments above, the material of the insulating member includes at least one of polyimide, mica and ceramic. Polyimide, mica and ceramic have the advantages of high melting point, high resistivity and good stability. Using these materials to manufacture insulating members can improve the insulation effect and improve the safety performance of cylindrical batteries.

[0012] In one or more of the above optional embodiments, the thickness of the insulating member is greater than the thickness of the first portion; and / or, the thickness of the insulating member is greater than the thickness of the second portion. The insulating member has a greater thickness, which can not only improve the insulation effect, but also increase the distance between the first portion and the second portion, reduce the curvature of the bent portion, and reduce the risk of the thinned portion being torn when the cylindrical battery is impacted.

[0013] In one or more optional embodiments above, the thickness of the insulating member is H0, the thickness of the first portion is H1, the thickness of the second portion is H2, 1.5≤H0 / H1≤4, 1.5≤H0 / H2≤4. Preferably, 2≤H0 / H1≤3, 2≤H0 / H2≤3.

[0014] Limiting H0 / H1 to be greater than or equal to 1.5 and limiting H0 / H2 to be greater than or equal to 1.5 can improve the insulation effect, reduce the curvature of the bent portion, and reduce the risk of tearing of the thinned portion when the cylindrical battery is impacted. Limiting H0 / H1 to be less than or equal to 4 and limiting H0 / H2 to be less than or equal to 4 can limit the space and weight occupied by the insulating member and reduce the impact of the insulating member on the energy density of the cylindrical battery.

[0015] In one or more optional embodiments above, the thickness of the first portion is H1, the thickness of the second portion is H2, and the thickness of the thinned portion is H3. 0.4≤H3 / H1≤0.8; and / or, 0.4≤H3 / H2≤0.8.

[0016] Limiting H3 / H1 to greater than or equal to 0.4 and limiting H3 / H2 to greater than or equal to 0.4 can improve the current capacity of the thinned portion when the cylindrical battery is working normally and reduce the risk of the thinned portion tearing when the cylindrical battery is impacted. Limiting H3 / H1 to less than or equal to 0.8 and limiting H3 / H2 to less than or equal to 0.8 can reduce the flow area of ​​the thinned portion, so that the thinned portion can be melted in time when an external short circuit occurs.

[0017] In one or more optional embodiments above, along the first direction, the first part has a first end, the second part has a second end, and the two ends of the bending portion are connected to the first end and the second end, respectively. In the second direction, the minimum dimension of the thinning portion is less than or equal to the dimension of the first end, and the minimum dimension of the thinning portion is less than or equal to the dimension of the second end. The first direction, the second direction and the axial direction are perpendicular to each other. The thinning portion has a smaller dimension in the second direction, which can reduce the flow area of ​​the thinning portion. When the current of the cylindrical battery increases sharply due to an accident, the thinning portion can be melted in time, thereby cutting off the circuit and reducing the risk of fire and explosion of the cylindrical battery.

[0018] In one or more optional embodiments above, along the second direction, the maximum dimension of the first part is W1, the maximum dimension of the second part is W2, and the maximum dimension of the thinned portion is W3. 0.2≤W3 / W1≤0.5, and / or, 0.2≤W3 / W2≤0.5, and / or, W1<W2.

[0019] Limiting W3 / W1 to be greater than or equal to 0.2 and limiting W3 / W2 to be greater than or equal to 0.2 can enable the thinned portion to meet the requirements for the flow area when the cylindrical battery is working normally, and reduce the risk of the thinned portion being torn when the cylindrical battery is impacted. Limiting W3 / W1 to be less than or equal to 0.5 and limiting W3 / W2 to be less than or equal to 0.5 can reduce the flow area of ​​the thinned portion, so that the thinned portion can be melted in time when an external short circuit occurs.

[0020] The second part needs to be connected to the pole piece of the electrode assembly, and the pole piece is usually wound into multiple turns; compared with the first part, the second part can have a larger size, which is conducive to connecting with pole pieces with more turns, thereby improving the current consistency of the pole piece and improving the cycle performance of the cylindrical battery. Compared with the second part, the first part can have a smaller size, thereby saving space and improving space utilization.

[0021] In one or more of the above optional embodiments, along the bending direction of the bending portion, the size of the thinning portion is V1, 1mm≤V1≤3mm, and the bending direction is perpendicular to the second direction. Limiting V1 to be greater than or equal to 1mm can increase the fusible portion of the thinning portion, increase the spacing between the residual portions after the thinning portion is melted, and reduce the risk of the residual portions of the thinning portion overlapping again. Limiting V1 to be less than or equal to 3mm can reduce the impact of the thinning portion on the overall strength of the collector plate and reduce the risk of the thinning portion tearing when the cylindrical battery is subjected to external impact.

[0022] In one or more optional embodiments above, the bending portion further includes a first connecting segment and a second connecting segment, the two ends of the first connecting segment respectively connect the thinning portion and the first part, and the two ends of the second connecting segment respectively connect the thinning portion and the second part. The thickness of the first connecting segment is greater than the thickness of the thinning portion, and the thickness of the second connecting segment is greater than the thickness of the thinning portion. By providing the first connecting segment and the second connecting segment, the strength of the bending portion can be increased.

[0023] In one or more optional embodiments above, the thickness of the first connecting section gradually decreases along the direction in which the first part points to the thinning portion; and / or, the thickness of the second connecting section gradually decreases along the direction in which the second part points to the thinning portion. The first connecting section has a structure in which the thickness gradually decreases, which can reduce the difficulty of bending the first connecting section, reduce the step at the connection between the first connecting section and the thinning portion, and reduce stress concentration. The second connecting section has a structure in which the thickness gradually decreases, which can reduce the difficulty of bending the second connecting section, reduce the step at the connection between the second connecting section and the thinning portion, and reduce stress concentration.

[0024] In one or more optional embodiments above, a recess is provided inside the bent portion, and the thinned portion is the bottom wall of the recess; and / or a recess is provided outside the bent portion, and the thinned portion is the bottom wall of the recess. The recess is provided to reduce the thickness of the thinned portion.

[0025] In a second aspect, the present application provides a battery module, which includes a cylindrical battery provided by any embodiment of the first aspect.

[0026] In a third aspect, the present application provides an electrical device, which includes a battery module provided in any embodiment of the second aspect. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The features, advantages and technical effects of exemplary embodiments of the present application will be described below with reference to the accompanying drawings.

[0028] Figure 1 A schematic diagram of the structure of a cylindrical battery provided in some embodiments of the present application;

[0029] Figure 2 for Figure 1A schematic cross-sectional view of a cylindrical battery;

[0030] Figure 3 for Figure 2 Enlarged schematic diagram at the box;

[0031] Figure 4 for Figure 3 An enlarged schematic diagram at box A;

[0032] Figure 5 A schematic diagram of a current collecting plate and an insulating member of a cylindrical battery in a separated state provided in some embodiments of the present application;

[0033] Figure 6 A schematic diagram of a current collecting plate of a cylindrical battery provided in some embodiments of the present application in a flattened state;

[0034] Figure 7 for Figure 6 A schematic cross-sectional view taken along the BB direction;

[0035] Figure 8 A partial cross-sectional schematic diagram of a cylindrical battery provided in some other embodiments of the present application;

[0036] Fig. 9 A partial cross-sectional schematic diagram of a cylindrical battery provided in some other embodiments of the present application;

[0037] Fig.10 A partial cross-sectional schematic diagram of a cylindrical battery provided in some other embodiments of the present application;

[0038] Fig.11 A schematic diagram of a battery module provided in some embodiments of the present application;

[0039] Fig.12 Schematic diagram of electrical equipment provided for some embodiments of the present application.

[0040] The reference numerals of the specific embodiments are as follows:

[0041]

[0042] DETAILED DESCRIPTION

[0043] In order to make the purpose, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly described below in conjunction with the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments.

[0044] The terms "first", "second", etc. in the specification and claims of this application or the above-mentioned drawings are used to distinguish different objects, rather than to describe a specific order or a primary and secondary relationship. In the embodiments of this application, the same reference numerals represent the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

[0045] Reference to "embodiment" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiment may be included in at least one embodiment of the present application. The appearance of the phrase in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments.

[0046] In the description of this application, it should be noted that, unless otherwise clearly specified and limited, the terms "installation", "connection", etc. should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a direct connection, or an indirect connection through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in this application can be understood according to specific circumstances.

[0047] In the embodiments of the present application, "parallel" includes not only the absolutely parallel situation, but also the roughly parallel situation conventionally recognized in engineering; at the same time, "perpendicular" also includes not only the absolutely perpendicular situation, but also the roughly perpendicular situation conventionally recognized in engineering. For example, if the angle between two directions is 85°-90°, the two directions can be considered perpendicular; if the angle between two directions is 0°-5°, the two directions can be considered parallel.

[0048] The cylindrical battery, battery module and electrical equipment of the present application are described below with reference to the accompanying drawings.

[0049] Reference Figures 1 to 7 , an embodiment of the present application provides a cylindrical battery 100 .

[0050] The cylindrical battery 100 may be, but is not limited to, a lithium ion battery, a sodium lithium ion battery, a sodium ion battery, or a magnesium ion battery.

[0051] The cylindrical battery 100 may be a cylindrical battery, an elliptical cylindrical battery, or a prismatic battery.

[0052] In some examples, the cylindrical battery 100 is a cylindrical battery. For example, the cylindrical battery may be a 21700 battery, a 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries.

[0053] In other examples, the cylindrical battery 100 is a prismatic battery, for example, a hexagonal prismatic battery, a quadrangular prismatic battery, or an octagonal prismatic battery.

[0054] In some embodiments, the cylindrical battery 100 is a secondary battery. After being discharged, the secondary battery can be charged to activate the active material and continue to be used.

[0055] In some embodiments, the cylindrical battery 100 includes a housing 1 and an electrode assembly 2 contained in the housing 1. Exemplarily, the housing 1 is used to provide a sealed containing space to contain the electrode assembly 2 and an electrolyte.

[0056] In some embodiments, the electrode assembly 2 includes a first electrode sheet and a second electrode sheet with opposite polarities. During the charge and discharge process of the cylindrical battery 100, active ions (such as lithium ions) are inserted and removed back and forth between the first electrode sheet and the second electrode sheet. One of the first electrode sheet and the second electrode sheet is a positive electrode sheet, and the other is a negative electrode sheet.

[0057] In some embodiments, the electrode assembly 2 includes a diaphragm disposed between the first electrode sheet and the second electrode sheet, and the diaphragm insulates the first electrode sheet from the second electrode sheet. The diaphragm can reduce the risk of short circuit between the positive and negative electrode sheets, while allowing active ions to pass through.

[0058] In some embodiments, the first pole piece includes a first pole piece body and a first pole ear connected to the first pole piece body, and the second pole piece includes a second pole piece body and a second pole ear connected to the second pole piece body. The first pole piece body includes a first current collector and a first active material layer coated on the surface of the first current collector, and the first pole ear is connected to the first current collector. The second pole piece body includes a second current collector and a second active material layer coated on the surface of the second current collector, and the second pole ear is connected to the second current collector. One of the first pole ear and the second pole ear is a positive pole ear, and the other is a negative pole ear. In other embodiments, the first pole ear is a first current collector not coated with the first active material layer, that is, in the width direction of the first pole piece, a portion of the first current collector is coated with the first active material layer to form the first pole piece body, and another portion of the first current collector is not coated with the first active material layer to form the first pole ear; the second pole ear is a second current collector not coated with the second active material layer, that is, in the width direction of the second pole piece, a portion of the second current collector is coated with the second active material layer to form the second pole piece body, and another portion of the second current collector is not coated with the second active material layer to form the second pole ear.

[0059] In some embodiments, the housing 1 includes a shell 11 and a cover 12. The shell 11 has an opening at at least one end along the axial direction Z of the cylindrical battery 100, and the cover 12 is connected to the shell 11 and covers the opening of the shell 11. The shell 11 and the cover 12 enclose a receiving space.

[0060] In some examples, the housing 11 is provided with an opening at one end along the axial direction Z. Specifically, the housing 11 includes a bottom wall 111 and a side wall 112, and the side wall 112 is connected to the bottom wall 111 and surrounds the electrode assembly 2. An opening is formed at one end of the side wall 112 away from the bottom wall 111 along the axial direction Z. The cover 12 is connected to the side wall 112. The cover 12 and the bottom wall 111 are arranged along the axial direction Z.

[0061] In other examples, the shell 11 is provided with openings at both ends along the axial direction Z. Specifically, the shell 11 includes a side wall 112 surrounding the electrode assembly 2, and the outer shell 1 includes two covers 12, which are respectively connected to both ends of the side wall 112 along the axial direction Z, and the two covers 12 cover the two openings respectively.

[0062] In some embodiments, the material of the housing 11 and the cover 12 can be steel, aluminum, composite metal or other conductive materials. The material of the housing 11 and the cover 12 can be the same or different.

[0063] In some embodiments, the cover 12 may be directly connected to the side wall 112 of the housing 11 , or may be indirectly connected to the side wall 112 of the housing 11 through other structures. In the axial direction Z, the electrode assembly 2 is located between the cover 12 and the bottom wall 111 .

[0064] In some embodiments, the housing 1 includes an electrode lead-out portion 1 a. The electrode lead-out portion 1 a is used to electrically connect the electrode assembly 2 to an external circuit to achieve charging or discharging of the cylindrical battery 100.

[0065] In some examples, the electrode lead 1a, the housing 11 and the cover 12 are independently formed and assembled together. In other examples, the electrode lead 1a can be at least part of the housing 11, or the electrode lead 1a can be at least part of the cover 12.

[0066] In some embodiments, there are two electrode lead-out portions 1a, and the two electrode lead-out portions 1a are connected to the first electrode tab and the second electrode tab, respectively. The two electrode lead-out portions 1a serve as the positive electrode lead-out portion and the negative electrode lead-out portion of the cylindrical battery 100, respectively, and the positive electrode lead-out portion and the negative electrode lead-out portion are used to be electrically connected to an external circuit to realize charging or discharging of the cylindrical battery 100.

[0067] In some embodiments, the housing 1 includes a shell 11 and a cover 12, and the cover 12 is insulated from the shell 11; the bottom wall 111 of the shell 11 is connected to the first pole ear, and the cover 12 is connected to the second pole ear; the bottom wall 111 of the shell 11 can be used as an electrode lead-out portion 1a, and the cover 12 can be used as another electrode lead-out portion 1a.

[0068] In some embodiments, the housing 1 includes a housing 11, a cover 12 and a pole 13, wherein the pole 13 is disposed on the cover 12. The bottom wall 111 of the housing 11 is connected to the first pole lug, and the pole 13 is connected to the second pole lug. The cover 12 is insulated from the housing 11, and the pole 13 is insulated from the cover 12; or, the cover 12 is electrically connected to the housing 11, and the pole 13 is insulated from the cover 12. The bottom wall 111 of the housing 11 can be used as an electrode lead-out portion 1a, and the pole 13 can be used as another electrode lead-out portion 1a.

[0069] In some embodiments, the housing 1 includes a housing 11, a cover 12 and a pole 13, wherein the pole 13 is disposed on the bottom wall 111 of the housing 11. The cover 12 is connected to the first pole lug, and the pole 13 is connected to the second pole lug. The pole 13 is insulated from the cover 12. The cover 12 can serve as an electrode lead-out portion 1a, and the pole 13 can serve as another electrode lead-out portion 1a.

[0070] In some embodiments, the housing 1 includes a shell 11 and two covers 12, and the two covers 12 are insulated from the shell 11. The two covers 12 are respectively connected to the first electrode tab and the second electrode tab. The two covers 12 serve as two electrode lead-out portions 1a.

[0071] In some embodiments, the housing 1 includes a shell 11, two covers 12 and poles 13, and the poles 13 are arranged on one cover 12. The cover 12 without the pole 13 is connected to the first pole lug, and the pole 13 is connected to the second pole lug. The pole 13 is insulated from the cover 12 without the pole 13. The cover 12 without the pole 13 can be used as an electrode lead-out portion 1a, and the pole 13 can be used as another electrode lead-out portion 1a.

[0072] In some embodiments, the housing 1 includes a shell 11, two covers 12 and two poles 13, and the two poles 13 are respectively arranged on the two covers 12. The two poles 13 are respectively connected to the first pole lug and the second pole lug, wherein the two covers 12 are respectively insulated from the shell 11, or the two poles 13 are respectively insulated from the covers 12. The two poles 13 serve as two electrode lead-out portions 1a.

[0073] In some embodiments, the electrode assembly 2 and the electrode lead-out portion 1 a are arranged along the axial direction Z of the cylindrical battery 100 .

[0074] In some embodiments, the cylindrical battery 100 further includes a current collecting plate 3. The current collecting plate 3 connects the electrode assembly 2 and the electrode lead-out portion 1a.

[0075] During the cycle of the cylindrical battery 100 , the current collecting plate 3 may transmit current between the electrode assembly 2 and the electrode lead-out portion 1 a .

[0076] In some embodiments, the current collecting plate 3 includes a first part 31, a second part 32 and a bending portion 33, the first part 31 is connected to the electrode lead-out portion 1a, the second part 32 is connected to the electrode assembly 2, the first part 31 and the second part 32 are spaced apart along the axial direction Z of the cylindrical battery 100, and the bending portion 33 connects the first part 31 and the second part 32.

[0077] As an example, the first portion 31 may be connected to the electrode lead-out portion 1a by welding, conductive adhesive bonding, etc. For example, the first portion 31 is connected to the electrode lead-out portion 1a by laser welding.

[0078] As an example, the second portion 32 can be connected to the electrode assembly 2 by welding, conductive adhesive bonding, etc. For example, a flattened area is provided at one end of the tab (first tab or second tab) facing the current collecting plate 3, and the second portion 32 is welded to the flattened area.

[0079] By bending the collecting plate 3 , the space occupied by the collecting plate 3 in the axial direction Z can be saved, thereby improving space utilization.

[0080] In some embodiments, the bending portion 33 includes a thinning portion 331 , the thickness of the thinning portion 331 is smaller than the thickness of the first portion 31 , and the thickness of the thinning portion 331 is smaller than the thickness of the second portion 32 .

[0081] The thickness of the first portion 31 and the thickness of the second portion 32 may be the same or different.

[0082] In some examples, the entire bending portion 33 may be the thinning portion 331 , or only a portion thereof may be the thinning portion 331 .

[0083] When the current of the cylindrical battery 100 increases sharply due to an accident (such as an external short circuit), the thinned portion 331 can generate heat and melt under the action of the current, thereby cutting off the circuit in time, slowing down the reaction of the cylindrical battery 100, and reducing the risk of fire and explosion of the cylindrical battery 100.

[0084] In some embodiments, the cylindrical battery 100 further includes an insulating member 4 . Along the axial direction Z, at least a portion of the insulating member 4 is disposed between the first portion 31 and the second portion 32 .

[0085] Along the axial direction Z, the insulating member 4 may be entirely located between the first portion 31 and the second portion 32 , or may be only partially located between the first portion 31 and the second portion 32 .

[0086] As an example, the insulating member 4 may be fixed to the collecting plate 3 , or may be movably placed between the first portion 31 and the second portion 32 .

[0087] When the thinned portion 331 is melted, the connection between the first portion 31 and the second portion 32 is disconnected. The insulating member 4 can separate the first portion 31 from the second portion 32, reducing the risk of contact and conduction between the first portion 31 and the second portion 32. When the cylindrical battery 100 is subjected to external impact, the insulating member 4 can limit the movement of the second portion 32 along the axial direction Z, thereby reducing the risk of the remaining portion of the bent portion 33 being melted and overlapped again, so that the circuit of the cylindrical battery 100 remains in a disconnected state, reducing the risk of fire and explosion of the cylindrical battery 100.

[0088] In the embodiment of the present application, the safety performance of the cylindrical battery 100 can be improved by providing the thinned portion 331 and the insulating member 4 .

[0089] In some embodiments, the collecting plate 3 is an integrally formed structure.

[0090] In some embodiments, along the radial direction of the cylindrical battery 100 , the insulating member 4 is spaced apart from the thinned portion 331 .

[0091] The embodiment of the present application can reduce the heat conducted to the insulating member 4 when the thinning portion 331 is melted, reduce the risk of the insulating member 4 melting and deforming at high temperature, improve the insulation effect, and enhance the safety performance.

[0092] In some embodiments, the insulating member 4 has a first surface 41 and a second surface 42 that are oppositely disposed along the axial direction Z. The first surface 41 contacts the first portion 31 , and the second surface 42 contacts the second portion 32 .

[0093] When the cylindrical battery 100 is subjected to external impact, the insulating member 4 can limit the movement of the second portion 32 toward the first portion 31, thereby reducing the risk of the remaining portion of the bent portion 33 being melted and overlapped again, thereby improving safety performance.

[0094] In some embodiments, at least one of the first portion 31 and the second portion 32 is fixed to the insulating member 4 .

[0095] The insulating member 4 may be fixed to the first portion 31 only, or to the second portion 32 only, or to both the first portion 31 and the second portion 32 at the same time.

[0096] When the cylindrical battery 100 is subjected to external impact, the first portion 31 or the second portion 32 can constrain the insulating member 4 , limit the movement of the insulating member 4 in the radial direction of the cylindrical battery 100 , and improve the insulation effect.

[0097] In some embodiments, the insulating member 4 is bonded to the first surface 41. For example, the insulating member 4 can be bonded to the first surface 41 by injection molding, gluing or other methods.

[0098] In some embodiments, the insulating member 4 can be fixed to the first portion 31 before the current collecting plate 3 is bent. Before the current collecting plate 3 is bent, the insulating member 4 does not cover the second portion 32, so the insulating member 4 does not interfere with the welding of the second portion 32 and the tab of the electrode assembly 2.

[0099] After the collecting plate 3 is bent, the insulating member 4 is in contact with the second surface 42 of the second portion 32 .

[0100] In some embodiments, the melting point of the insulating member 4 is greater than or equal to 500°C.

[0101] As an example, the melting point of the insulating member 4 may be 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1400°C, 1500°C, 1800°C, or 2000°C.

[0102] The insulating member 4 has a relatively high melting point. When the current of the cylindrical battery 100 increases sharply due to an accident, the insulating member 4 is not easily melted under the high temperature of the current collecting plate 3, thereby effectively supporting and isolating the first part 31 and the second part 32, reducing the risk of the circuit being turned on again after the thinning part 331 is melted, and improving safety performance.

[0103] In some embodiments, the material of the insulating member 4 includes at least one of polyimide, mica, and ceramic.

[0104] Polyimide, mica and ceramics have the advantages of high melting point, high resistivity and good stability. Using these materials to manufacture the insulating member 4 can improve the insulation effect and enhance the safety performance of the cylindrical battery 100.

[0105] In some embodiments, the thickness of the insulating member 4 is greater than the thickness of the first portion 31. In other embodiments, the thickness of the insulating member 4 is greater than the thickness of the second portion 32. In yet another embodiment, the thickness of the insulating member 4 is greater than the thickness of the first portion 31, and the thickness of the insulating member 4 is greater than the thickness of the second portion 32.

[0106] The insulating member 4 has a relatively large thickness, which can not only improve the insulation effect, but also increase the distance between the first portion 31 and the second portion 32 , reduce the curvature of the bent portion 33 , and reduce the risk of the thinned portion 331 being torn when the cylindrical battery 100 is impacted.

[0107] In some embodiments, the thickness of the insulating member 4 is H0, the thickness of the first portion 31 is H1, the thickness of the second portion 32 is H2, 1.5≤H0 / H1≤4, 1.5≤H0 / H2≤4.

[0108] As examples, H0 / H1 may be 1.5, 2, 2.5, 3, 3.5, or 4. H0 / H2 may be 1.5, 2, 2.5, 3, 3.5, or 4.

[0109] In the embodiment of the present application, H0 / H1 is limited to be greater than or equal to 1.5, and H0 / H2 is limited to be greater than or equal to 1.5, which can improve the insulation effect, reduce the curvature of the bent portion 33, and reduce the risk of the thinned portion 331 being torn when the cylindrical battery 100 is impacted. H0 / H1 is limited to be less than or equal to 4, and H0 / H2 is limited to be less than or equal to 4, which can limit the space and weight occupied by the insulating member 4, and reduce the effect of the insulating member 4 on the energy density of the cylindrical battery 100.

[0110] In some embodiments, 2≤H0 / H1≤3, 2≤H0 / H2≤3.

[0111] In some embodiments, H1 = H2.

[0112] In some embodiments, the thickness of the first portion 31 is H1, the thickness of the second portion 32 is H2, and the thickness of the thinned portion 331 is H3.

[0113] In some embodiments, 0.4≤H3 / H1≤0.8. As an example, H3 / H1 may be 0.4, 0.5, 0.6, 0.7 or 0.8.

[0114] By limiting H3 / H1 to be greater than or equal to 0.4, the current capacity of the thinned portion 331 can be improved when the cylindrical battery 100 is operating normally, and the risk of the thinned portion 331 being torn when the cylindrical battery 100 is impacted can be reduced. By limiting H3 / H1 to be less than or equal to 0.8, the flow area of ​​the thinned portion 331 can be reduced, so that the thinned portion 331 can be melted in time when an external short circuit occurs.

[0115] In some embodiments, 0.4≤H3 / H2≤0.8. As an example, H3 / H2 may be 0.4, 0.5, 0.6, 0.7 or 0.8.

[0116] By limiting H3 / H2 to be greater than or equal to 0.4, the current capacity of the thinned portion 331 can be improved when the cylindrical battery 100 is operating normally, and the risk of the thinned portion 331 being torn when the cylindrical battery 100 is impacted can be reduced. By limiting H3 / H2 to be less than or equal to 0.8, the flow area of ​​the thinned portion 331 can be reduced, so that the thinned portion 331 can be melted in time when an external short circuit occurs.

[0117] In some embodiments, 0.4≤H3 / H1≤0.8, 0.4≤H3 / H2≤0.8.

[0118] In some embodiments, along the first direction X, the first portion 31 has a first end 311, the second portion 32 has a second end 321, and the two ends of the bent portion 33 are respectively connected to the first end 311 and the second end 321. In the second direction Y, the minimum dimension of the thinned portion 331 is less than or equal to the dimension of the first end 311, and the minimum dimension of the thinned portion 331 is less than or equal to the dimension of the second end 321. The first direction X, the second direction Y, and the axial direction Z are perpendicular to each other.

[0119] Exemplarily, after the current collecting disk 3 is flattened, the first portion 31, the bent portion 33, and the second portion 32 are sequentially arranged along the length direction L of the current collecting disk 3. In the length direction L, the first end 311 is opposite to the second end 321. The dimension of the thinned portion 331 along the second direction Y may be equal to the dimension of the thinned portion 331 along the width direction W of the current collecting disk 3 after the current collecting disk 3 is flattened. The dimension of the first end 311 along the second direction Y may be equal to the dimension of the first end 311 along the width direction W of the current collecting disk 3 after the current collecting disk 3 is flattened. The dimension of the second end 321 along the second direction Y may be equal to the dimension of the second end 321 along the width direction W of the current collecting disk 3 after the current collecting disk 3 is flattened.

[0120] In the embodiment of the present application, the thinning portion 331 has a smaller size in the second direction Y, which can reduce the flow area of ​​the thinning portion 331. When the current of the cylindrical battery 100 increases sharply due to an accident, the thinning portion 331 can be melted in time, thereby cutting off the circuit and reducing the risk of fire and explosion of the cylindrical battery 100.

[0121] In some embodiments, in the second direction Y, the maximum dimension of the first portion 31 is greater than the dimension of the first end 311 .

[0122] In some embodiments, in the second direction Y, the maximum dimension of the second portion 32 is greater than the dimension of the second end 321 .

[0123] In some embodiments, in the second direction Y, the minimum dimension of the thinned portion 331 is smaller than the dimension of the first end 311 , and smaller than the dimension of the second end 321 .

[0124] In some embodiments, along the second direction Y, the maximum dimension of the first portion 31 is W1 , the maximum dimension of the second portion 32 is W2 , and the maximum dimension of the thinned portion 331 is W3 .

[0125] In some embodiments, 0.2≤W3 / W1≤0.5. Limiting W3 / W1 to be greater than or equal to 0.2 allows the thinning portion 331 to meet the requirements for the flow area when the cylindrical battery 100 is working normally, and reduces the risk of the thinning portion 331 being torn when the cylindrical battery 100 is impacted. Limiting W3 / W1 to be less than or equal to 0.5 can reduce the flow area of ​​the thinning portion 331, so that the thinning portion 331 can be melted in time when an external short circuit occurs.

[0126] In some embodiments, 0.2≤W3 / W2≤0.5. Limiting W3 / W2 to be greater than or equal to 0.2 allows the thinning portion 331 to meet the requirements for the flow area when the cylindrical battery 100 is working normally, and reduces the risk of the thinning portion 331 being torn when the cylindrical battery 100 is impacted. Limiting W3 / W2 to be less than or equal to 0.5 can reduce the flow area of ​​the thinning portion 331, so that the thinning portion 331 can be melted in time when an external short circuit occurs.

[0127] In some embodiments, W1<W2. The second portion 32 needs to be connected to the pole piece of the electrode assembly 2, and the pole piece is usually wound into multiple turns; compared with the first portion 31, the second portion 32 can have a larger size, which is conducive to connecting with pole pieces with more turns, thereby improving the current consistency of the pole piece and improving the cycle performance of the cylindrical battery 100. Compared with the second portion 32, the first portion 31 can have a smaller size, thereby saving space and improving space utilization.

[0128] In some embodiments, 0.2≤W3 / W1≤0.5, 0.2≤W3 / W2≤0.5, W1<W2.

[0129] In some embodiments, along the bending direction V of the bending portion 33 , the size of the thinned portion 331 is V1 , 1 mm≤V1≤3 mm, and the bending direction V is perpendicular to the second direction Y.

[0130] As an example, the dimension of the thinned portion 331 along the bending direction V may be equal to the dimension L1 of the thinned portion 331 along the length direction L of the current collecting plate 3 after the current collecting plate 3 is flattened.

[0131] By limiting V1 to be greater than or equal to 1 mm, the fusible portion of the thinned portion 331 can be increased, the spacing between the residual portions of the thinned portion 331 after melting can be increased, and the risk of the residual portions of the thinned portion 331 being overlapped again can be reduced. By limiting V1 to be less than or equal to 3 mm, the influence of the thinned portion 331 on the overall strength of the current collecting plate 3 can be reduced, and the risk of the thinned portion 331 being torn when the cylindrical battery 100 is subjected to external impact can be reduced.

[0132] In some embodiments, the bending portion 33 is provided with a recess 334, and the thinning portion 331 is the bottom wall of the recess 334. By providing the recess 334, the thickness of the thinning portion 331 is reduced.

[0133] As an example, the recess 334 of the collecting plate 3 may be formed by pressing, etching, milling or other methods.

[0134] In some embodiments, the recess 334 is disposed on the inner side of the bending portion 33. Providing the recess 334 on the inner side can increase the distance between the thinning portion 331 and the insulating member 4.

[0135] In some embodiments, the cylindrical battery 100 is a cylindrical battery.

[0136] In some embodiments, the housing 1 includes a shell 11 and a cover 12 , and a bottom wall 111 of the shell 11 serves as an electrode lead-out portion 1 a and is connected to the first portion 31 .

[0137] Reference Figure 8 In some embodiments, the bending portion 33 further includes a first connecting segment 332 and a second connecting segment 333, wherein two ends of the first connecting segment 332 are respectively connected to the thinning portion 331 and the first portion 31, and two ends of the second connecting segment 333 are respectively connected to the thinning portion 331 and the second portion 32.

[0138] The thickness of one end of the first connecting section 332 connected to the first part 31 is greater than the thickness of the thinning portion 331, and the thickness of one end of the first connecting section 332 connected to the thinning portion 331 is greater than or equal to the thickness of the thinning portion 331; the thickness of one end of the second connecting section 333 connected to the second part 32 is greater than the thickness of the thinning portion 331, and the thickness of one end of the second connecting section 333 connected to the thinning portion 331 is greater than or equal to the thickness of the thinning portion 331.

[0139] By providing the first connecting section 332 and the second connecting section 333 , the strength of the bending portion 33 can be increased.

[0140] In addition, the first connecting segment 332 and the second connecting segment 333 both have a relatively large thickness, and the first connecting segment 332 and the second connecting segment 333 are in a bent state; after the thinning portion 331 is melted, the first connecting segment 332 and the second connecting segment 333 can be moved away from each other under the action of the elastic restoring force, thereby reducing the risk of the remaining part of the thinning portion 331 overlapping again.

[0141] In some embodiments, the thickness of one end of the first connecting segment 332 connected to the first portion 31 is equal to the thickness of the first portion 31 .

[0142] In some embodiments, the thickness of one end of the second connecting segment 333 connected to the second portion 32 is equal to the thickness of the second portion 32 .

[0143] In some embodiments, the first connecting segment 332 , the second connecting segment 333 , and the thinned portion 331 define a recess 334 .

[0144] Reference Fig. 9 In some embodiments, along the direction from the first portion 31 to the thinning portion 331 , the thickness of the first connecting segment 332 gradually decreases.

[0145] As an example, the thickness of one end of the first connecting section 332 connected to the thinned portion 331 is equal to the thickness of the thinned portion 331 .

[0146] The first connecting section 332 has a structure with gradually decreasing thickness, which can reduce the difficulty of bending the first connecting section 332 and reduce the step at the connection between the first connecting section 332 and the thinning portion 331, thereby reducing stress concentration.

[0147] In some embodiments, along the direction of the second portion 32 pointing toward the thinning portion 331 , the thickness of the second connecting segment 333 gradually decreases.

[0148] The second connecting section 333 has a structure with gradually decreasing thickness, which can reduce the difficulty of bending the second connecting section 333 and reduce the step at the connection between the second connecting section 333 and the thinning portion 331, thereby reducing stress concentration.

[0149] In some embodiments, after the collecting plate 3 is flattened, the cross section of the first connecting section 332 perpendicular to the width direction W of the collecting plate 3 is trapezoidal, and the cross section of the second connecting section 333 perpendicular to the width direction W of the collecting plate 3 is trapezoidal.

[0150] Reference Fig.10 In some embodiments, a recess 334 is provided on the outer side of the bending portion 33 , and the thinning portion 331 is the bottom wall of the recess 334 .

[0151] In some other embodiments, recesses 334 are disposed on both inner and outer sides of the bending portion 33 , and a portion of the bending portion 33 located between the bottom surfaces of the two recesses 334 is the thinning portion 331 .

[0152] Reference Fig.11 The embodiment of the present application further provides a battery module 200, and the battery module 200 includes a plurality of cylindrical batteries 100 provided according to any embodiment of the present application.

[0153] In some embodiments, the battery module 200 further includes a plurality of busbars (not shown), which connect the plurality of cylindrical batteries 100. For example, the busbars are welded to the electrode lead-out portions 1a of the cylindrical batteries 100.

[0154] Reference Fig.12The embodiment of the present application further provides an electric device 300, which includes the cylindrical battery 100 provided in any embodiment of the present application or the battery module 200 provided in any embodiment of the present application.

[0155] The electric device 300 of the embodiment of the present application may be a portable device, a laptop computer, an electric toy, a drone, an electric tool, an energy storage system, etc. The electric tool includes a metal cutting electric tool, a cleaning tool, etc., for example, an electric drill, an electric wrench, a vacuum cleaner, a sweeping robot, a power-assisted bicycle, etc. The embodiment of the present application does not impose any special restrictions on the above-mentioned electric device 300.

[0156] Although the present application has been described with reference to preferred embodiments, various modifications may be made thereto and parts thereof may be replaced with equivalents without departing from the scope of the present application. In particular, the various technical features mentioned in the various embodiments may be combined in any manner as long as there is no structural conflict. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A cylindrical battery, characterized in that: include: A housing including an electrode lead-out portion; An electrode assembly is contained in the housing, wherein the electrode assembly and the electrode lead-out portion are arranged along the axial direction of the cylindrical battery; A current collecting plate, comprising a first portion, a second portion and a bent portion, wherein the first portion is connected to the electrode lead-out portion, the second portion is connected to the electrode assembly, the first portion and the second portion are spaced apart along the axial direction of the cylindrical battery, the bent portion connects the first portion and the second portion, the bent portion comprises a thinned portion, the thickness of the thinned portion is less than the thickness of the first portion, and the thickness of the thinned portion is less than the thickness of the second portion; An insulating member, along the axial direction, at least a portion of the insulating member is disposed between the first portion and the second portion.

2. The cylindrical battery according to claim 1, characterized in that: Along the radial direction of the cylindrical battery, the insulating member is spaced apart from the thinned portion.

3. The cylindrical battery according to claim 1 or 2, characterized in that: The insulating member has a first surface and a second surface that are opposite to each other along the axial direction, the first surface is in contact with the first portion, and the second surface is in contact with the second portion.

4. The cylindrical battery according to any one of claims 1 to 3, characterized in that: At least one of the first portion and the second portion is fixed to the insulating member.

5. The cylindrical battery according to any one of claims 1 to 4, characterized in that: The melting point of the insulating member is greater than or equal to 500°C.

6. The cylindrical battery according to any one of claims 1 to 5, characterized in that: The material of the insulating member includes at least one of polyimide, mica and ceramic.

7. The cylindrical battery according to any one of claims 1 to 6, characterized in that: The thickness of the insulating member is greater than the thickness of the first portion; and / or the thickness of the insulating member is greater than the thickness of the second portion.

8. The cylindrical battery according to any one of claims 1 to 7, characterized in that: The thickness of the insulating member is H0, the thickness of the first portion is H1, the thickness of the second portion is H2, 1.5≤H0 / H1≤4, 1.5≤H0 / H2≤4; Preferably, 2≤H0 / H1≤3, 2≤H0 / H2≤3.

9. The cylindrical battery according to any one of claims 1 to 8, characterized in that: The thickness of the first portion is H1, the thickness of the second portion is H2, and the thickness of the thinned portion is H3; 0.4≤H3 / H1≤0.8; and / or, 0.4≤H3 / H2≤0.

8.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that: Along a first direction, the first portion has a first end, the second portion has a second end, and two ends of the bent portion are respectively connected to the first end and the second end; In the second direction, the smallest dimension of the thinned portion is smaller than or equal to the dimension of the first end, and the smallest dimension of the thinned portion is smaller than or equal to the dimension of the second end; The first direction, the second direction and the axial direction are perpendicular to each other.

11. The cylindrical battery according to claim 10, characterized in that: Along the second direction, the maximum dimension of the first portion is W1, the maximum dimension of the second portion is W2, and the maximum dimension of the thinned portion is W3; 0.2≤W3 / W1≤0.5, and / or, 0.2≤W3 / W2≤0.5, and / or, W1<W2.

12. The cylindrical battery according to claim 10 or 11, characterized in that: Along the bending direction of the bending portion, the size of the thinned portion is V1, 1mm≤V1≤3mm, and the bending direction is perpendicular to the second direction.

13. The cylindrical battery according to any one of claims 1 to 12, characterized in that: The bending portion further includes a first connecting section and a second connecting section, wherein two ends of the first connecting section are respectively connected to the thinning portion and the first part, and two ends of the second connecting section are respectively connected to the thinning portion and the second part; The thickness of the first connecting section is greater than the thickness of the thinned portion, and the thickness of the second connecting section is greater than the thickness of the thinned portion.

14. The cylindrical battery according to claim 13, characterized in that: Along the direction from the first portion to the thinned portion, the thickness of the first connecting section gradually decreases; and / or, Along the direction of the second portion pointing toward the thinned portion, the thickness of the second connecting section gradually decreases.

15. The cylindrical battery according to any one of claims 1 to 13, characterized in that: A recess is provided on the inner side of the bending portion, and the thinned portion is the bottom wall of the recess; and / or, A concave portion is disposed on the outer side of the bending portion, and the thinned portion is the bottom wall of the concave portion.

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

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

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