Cylindrical battery and manufacturing method therefor, battery module and electrical device

Abstract

Disclosed in the present application are a cylindrical battery and a manufacturing method therefor, a battery module and an electrical device. The cylindrical battery comprises a casing, an end cover, an electrode assembly, a first insulator, a second insulator and a third insulator. The electrode assembly comprises an electrode main body of a winding structure and a first tab, at least part of the first tab protruding from a first end surface of the electrode main body facing the end cover, and being connected to the end cover. The first insulator is arranged along the outer periphery of the electrode main body and is connected to the electrode main body, and the first insulator covers at least part of the tail end of the electrode main body in a winding direction. The second insulator covers at least part of the end portion of the electrode main body close to the first tab from the outside, part of the first insulator being located between the second insulator and the electrode main body. The third insulator covers the first tab from the outside, at least part of the second insulator being located between the electrode main body and the third insulator, and, in the axial direction of the cylindrical battery, part of the third insulator being located between the first tab and the end cover.

Description

Cylindrical batteries and their manufacturing methods, battery modules and electrical devices

[0001] Cross-references to related applications

[0002] This application claims priority to Chinese Patent Application No. 202411975413.1, filed on December 30, 2024, entitled “Cylindrical Battery and Method for Manufacturing the Same Thereof, Battery Module and Electrical Device,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] This application relates to the field of batteries, and in particular to a cylindrical battery and its preparation method, battery module and electrical device. Background Technology

[0004] Rechargeable batteries are batteries that can be recharged after being discharged to reactivate the active materials and continue to be used. Rechargeable batteries are widely used in electronic devices such as mobile phones, laptops, and drones.

[0005] Electrode components are the parts in a battery where electrochemical reactions occur, and the winding effect of these components has a significant impact on the battery's charge-discharge performance and capacity. Improving the winding effect of electrode components has always been a research focus in the industry. Summary of the Invention

[0006] This application provides a cylindrical battery and its preparation method, battery module and electrical device, which can improve the winding effect of the electrode assembly of the cylindrical battery.

[0007] In a first aspect, this application provides a cylindrical battery, comprising a casing, an end cap, an electrode assembly, a first insulating member, a second insulating member, and a third insulating member. The casing has an opening. The end cap is connected to the casing and closes the opening. The electrode assembly includes an electrode body and a first tab. The electrode body has a wound structure, and at least a portion of the first tab protrudes from a first end face of the electrode body facing the end cap and is connected to the end cap. The first insulating member is disposed along the outer periphery of the electrode body and connected to the electrode body, and the first insulating member covers at least a portion of the tail end of the electrode body along the winding direction. The second insulating member covers at least a portion of the electrode body from the outside near the end of the first tab, and a portion of the first insulating member is located between the second insulating member and the electrode body. The third insulating member covers the first tab from the outside, and at least a portion of the second insulating member is located between the electrode body and the third insulating member. In the axial direction of the cylindrical battery, a portion of the third insulating member is located between the first tab and the end cap. In this embodiment, by sequentially covering the outer side of the electrode body with a first insulating element, a second insulating element, and a third insulating element, the electrode body can be subjected to multiple constraints, which is beneficial to improving the tightness and structural stability of the electrode body winding and improving the winding effect of the electrode assembly.

[0008] In one or more of the above optional embodiments, along the direction of the electrode assembly pointing towards the end cap, the second insulating member extends beyond the first insulating member, and the portion of the second insulating member extending beyond the first insulating member is connected to the electrode body. On the one hand, the second insulating member can cover at least a portion of the end of the first insulating member near the first tab, making it less likely for the end of the first insulating member near the first tab to unravel or loosen; on the other hand, the second insulating member can be directly connected to the electrode body, which helps to reduce the risk of the second insulating member falling off due to the influence of the first insulating member, and further improves the tightness and structural stability of the electrode body winding.

[0009] In one or more of the above optional embodiments, along the direction from the electrode assembly to the end cap, the distance between the end of the first insulating member near the end cap and the first end face is 1mm-3mm. This not only helps to reduce the impact on the radial dimension of the end of the electrode body near the first tab, but also helps to improve the structural stability of the electrode body.

[0010] In one or more of the above optional embodiments, the second insulating member does not extend beyond the first end face along the direction from the electrode assembly to the end cap. This helps to reduce the possibility of interference between the second insulating member and the first tab, and reduces the interference of the second insulating member on the smoothing or flattening operation of the first tab.

[0011] In one or more of the above optional embodiments, portions of the second insulating member are arranged to overlap radially along the cylindrical battery. This strengthens the connection between the second insulating member and the electrode body, as well as the connection with the first insulating member, thereby improving the installation stability of the second insulating member.

[0012] In one or more of the above optional embodiments, a gap is provided between the two ends of the first insulating member along the circumferential direction of the cylindrical battery. The gap can provide expansion space for the electrode assembly, which is beneficial for the electrode assembly to release expansion force and reduce safety risks.

[0013] In one or more of the above optional embodiments, the circumferential dimension of the gap is less than or equal to 1 mm. Therefore, the size of the gap can be minimized while ensuring that the electrode assembly can release expansion force through the gap, which helps to limit the expansion degree of the electrode body and improve the tightness and stability of the winding structure of the electrode body.

[0014] In one or more of the above optional embodiments, the elongation of the first insulating member is greater than that of the second insulating member; and / or, the tensile strength of the second insulating member is greater than that of the first insulating member. This allows only the portion of the electrode body covered by the first insulating member to expand within a suitable range, while also providing greater restraint on the end of the electrode body near the first tab, thus balancing the safety of the cylindrical battery with the tightness of the electrode assembly's winding and its structural stability.

[0015] In one or more of the above optional embodiments, along the direction from the end cap to the electrode assembly, the end of the second insulating member away from the end cap extends beyond the third insulating member. This reduces the likelihood of the third insulating member being directly connected to the first insulating member, lowers the risk of the first insulating member being deformed due to the third insulating member pulling on it, and facilitates a tighter wrapping of the electrode body by the first insulating member.

[0016] In one or more of the above optional embodiments, along the direction from the end cap to the electrode assembly, the end of the second insulating member away from the end cap extends beyond the third insulating member by less than or equal to 1.5 mm. This facilitates both the extension and deformation of the first insulating member and the moderate expansion of the electrode body, while also improving the tightness and stability of the third insulating member covering the electrode body and the second insulating member, reducing the risk of the third insulating member detaching.

[0017] In one or more of the above optional embodiments, the third insulating member includes a first insulating portion and a second insulating portion. The first insulating portion is disposed between the first electrode tab and the end cap and covers a portion of the first electrode tab. The second insulating portion surrounds the first insulating portion, and at least a portion of the second insulating member is located between the electrode body and the second insulating portion. A portion of the first insulating portion overlaps along the axial direction of the cylindrical battery, and a portion of the second insulating portion overlaps along the radial direction of the cylindrical battery. This facilitates strengthening the connection between the third insulating member and the first electrode tab, the electrode body, and the second insulating member, and improves the installation stability of the third insulating member.

[0018] In one or more of the above optional embodiments, the melting point of the third insulating element is greater than that of the second insulating element, and / or the melting point of the third insulating element is greater than that of the first insulating element. The relatively high melting point of the third insulating element allows it to withstand higher temperatures, reducing the risk of insulation failure due to the third insulating element melting under heat.

[0019] In one or more of the above optional embodiments, the thickness of the third insulating member is greater than the thickness of the second insulating member. The greater thickness of the third insulating member reduces the likelihood of it being punctured by burrs on the first tab, thus helping to reduce the risk of short circuits.

[0020] In one or more of the above optional embodiments, both the first and second insulating components are bonded to the electrode body, and the third insulating component is bonded to the second insulating component. The bonding method is simple and the connection is relatively stable.

[0021] In one or more of the above optional embodiments, the first insulating member covers the middle portion of the electrode body along the axial direction. This provides a more balanced covering and confinement effect on the electrode body, reducing the risk of the electrode body spreading out at both ends along the axial direction of the cylindrical battery and improving the covering effect of the first insulating member on the electrode body.

[0022] In one or more of the above optional embodiments, the electrode assembly further includes a second tab, at least a portion of which protrudes from a second end face of the electrode body opposite to the end cap, and the first tab and the second tab have opposite polarities; the cylindrical battery includes a fourth insulating member, which covers at least a portion of the electrode body near the end of the second tab from the outside, and a portion of the first insulating member is located between the fourth insulating member and the electrode body. The fourth insulating member can radially constrain the end of the electrode body near the second tab and the first insulating member of the cylindrical battery, which on the one hand can improve the tightness of the contact interface between the electrode and the separator, which is beneficial to improving the ion transport and intercalation effect; on the other hand, it can also enhance the structural stability of the electrode assembly.

[0023] In one or more of the above optional embodiments, in the direction from the first end face to the second end face, the fourth insulating member extends beyond the first insulating member, and the portion of the fourth insulating member extending beyond the first insulating member is connected to the electrode body. On the one hand, the fourth insulating member can cover at least a portion of the end of the first insulating member near the second tab, making it less likely for the end of the first insulating member near the second tab to unravel or loosen; on the other hand, the fourth insulating member can be directly connected to the electrode body, which helps to reduce the risk of the fourth insulating member falling off due to the influence of the first insulating member, and further improves the tightness and structural stability of the electrode body winding.

[0024] In one or more of the above optional embodiments, along the direction from the first end face to the second end face, the distance between the end of the first insulating member near the second end face and the second end face is 1mm-3mm. This not only helps to reduce the impact on the radial dimension of the end of the electrode body near the second tab, but also helps to improve the structural stability of the electrode body.

[0025] Secondly, embodiments of this application provide a method for fabricating a cylindrical battery. The method includes: providing an electrode assembly with a wound structure, wherein the electrode assembly includes an electrode body and a first tab, at least a portion of the first tab protruding from a first end face of the electrode body along its own axial direction; connecting a first insulating member to the outer periphery of the electrode body, and having the first insulating member cover at least a portion of the tail end of the electrode body along the winding direction; covering the outer side of the electrode body near the end of the first tab and the outer side of a portion of the first insulating member with a second insulating member; and covering the outer side of the first tab and the outer side of at least a portion of the second insulating member with a third insulating member.

[0026] In one or more of the above optional embodiments, before covering the outer side of the first electrode tab and the outer side of at least a portion of the second insulating member with the third insulating member, the preparation method further includes: flattening or patting the first electrode tab; after covering the outer side of the first electrode tab and the outer side of at least a portion of the second insulating member with the third insulating member, the preparation method further includes: folding a portion of the third insulating member to the side of the first electrode tab that is axially away from the electrode body.

[0027] Thirdly, embodiments of this application also provide a battery module comprising a plurality of cylindrical batteries provided according to any embodiment of the first aspect.

[0028] Fourthly, embodiments of this application also provide an electrical device that includes a battery module provided according to any embodiment of the third aspect. Attached Figure Description

[0029] The features, advantages, and technical effects of exemplary embodiments of this application will now be described with reference to the accompanying drawings.

[0030] Figure 1 is a schematic diagram of the structure of a cylindrical battery provided in some embodiments of this application;

[0031] Figure 2 is a cross-sectional view of the cylindrical battery shown in Figure 1.

[0032] Figure 3 is a cross-sectional view of the cylindrical battery shown in Figure 1 after the first insulating component covers the electrode assembly.

[0033] Figure 4 is a cross-sectional view of the cylindrical battery shown in Figure 1 after removing the casing and end caps.

[0034] Figure 5 is an enlarged structural diagram of region A in Figure 4;

[0035] Figure 6 is a schematic diagram of the structure of the electrode assembly of a cylindrical battery provided in some embodiments of this application after being covered with a first insulating member;

[0036] Figure 7 is a schematic diagram of the structure of the electrode assembly of a cylindrical battery provided in some embodiments of this application after being covered with a first insulating member, a second insulating member and a fourth insulating member;

[0037] Figure 8 is a schematic diagram of the structure of the electrode assembly of a cylindrical battery provided in some embodiments of this application after being covered with a first insulating member, a second insulating member, a third insulating member, and a fourth insulating member;

[0038] Figure 9 is a schematic flowchart of a method for preparing a cylindrical battery according to some embodiments of this application;

[0039] Figure 10 is a schematic flowchart of a method for preparing a cylindrical battery according to other embodiments of this application;

[0040] Figure 11 is a schematic diagram of the structure of a battery module provided in some embodiments of this application;

[0041] Figure 12 is a schematic diagram of the structure of electrical equipment provided in some embodiments of this application.

[0042] The reference numerals in the accompanying drawings of the specific embodiments are as follows: Cylindrical battery 1, busbar 2, bracket 3; Housing 10, opening 11, bottom wall 12, side wall 13, end cap 20, electrode assembly 30, first electrode 31, first tab 312, second electrode 32, second tab 322, separator 33, electrode body 34, first part 341, second part 342, third part 343, first end face 34a, tail end 34b, second end face 34c, first insulating member 40, first end 40a, second end 40b, gap 40c, second insulating member 50, first starting end 50a, first ending end 50b, third insulating member 60, second starting end 60a, second ending end 60b, first insulating part 61, second insulating part 62, fourth insulating member 70, central axis a, dimension d1, dimension d2, dimension d3, winding direction V, axial direction X; Battery module 100; 1000 electrical devices. Detailed Implementation

[0043] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly described below with reference to the accompanying drawings. Obviously, the described embodiments are some embodiments of this application, but not all embodiments.

[0044] The terms "first," "second," "third," etc., used in the specification, claims, or accompanying drawings of this application are used to distinguish different objects, not to describe a specific order or hierarchy. In the embodiments of this application, the same reference numerals denote the same components, and for the sake of brevity, detailed descriptions of the same components are omitted in different embodiments.

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

[0046] In the description of this application, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application according to the specific circumstances.

[0047] In the embodiments of this application, "parallel" includes not only the case of absolute parallelism, but also the case of approximate parallelism as commonly understood in engineering; similarly, "perpendicular" also includes not only the case of absolute perpendicularity, but also the case of approximate perpendicularity as commonly understood in engineering. For example, if the angle between two directions is 85°-95°, the two directions can be considered perpendicular; if the angle between two directions is 0°-10°, the two directions can be considered parallel.

[0048] The cylindrical battery, its preparation method, battery module, and electrical device of this application are described below with reference to the accompanying drawings.

[0049] This application provides a cylindrical battery 1, which can be a lithium-ion battery, a sodium-lithium-ion battery, a sodium-ion battery, a magnesium-ion battery, or other types of batteries.

[0050] For example, the cylindrical battery 1 can be a 21700 battery, an 18650 battery, a 46800 battery, a 49480 battery, or other types of cylindrical batteries.

[0051] In some embodiments, the cylindrical battery 1 is a secondary battery. After discharge, the secondary battery can be recharged to activate the active materials and continue to be used.

[0052] In some embodiments, the cylindrical battery 1 includes a housing 10 having an opening 11. The opening 11 may be located at one end of the cylindrical battery 1 along its own axial direction X.

[0053] In some embodiments, the housing 10 further includes a bottom wall 12 and a side wall 13, with the opening 11 disposed opposite to the bottom wall 12 along the axial direction X, the side wall 13 being connected to the bottom wall 12 and enclosing the bottom wall 12 to form a cylindrical space, which is open to the outside through the opening 11.

[0054] The bottom wall 12 and the side wall 13 can be integrally formed or connected by welding, riveting or other suitable methods.

[0055] In some embodiments, the cylindrical battery 1 further includes an end cap 20, which is connected to the housing 10 and covers the opening 11.

[0056] The end cap 20 can close the opening 11, thereby forming a closed cylindrical space between the housing 10 and the end cap 20.

[0057] In some embodiments, the housing 10 and the end cap 20 may be made of steel, aluminum, composite metal, or other conductive materials. The housing 10 and the end cap 20 may be made of the same or different materials.

[0058] In some embodiments, the end cap 20 may be directly connected to the side wall 13 of the housing 10, or it may be indirectly connected to the side wall 13 of the housing 10 through other structures.

[0059] In some embodiments, the cylindrical battery 1 further includes an electrode assembly 30 disposed within the housing 10. The end cap 20 and the electrode assembly 30 may be arranged along the axial direction X of the cylindrical battery 1.

[0060] In some embodiments, the electrode assembly 30 includes a first electrode 31 and a second electrode 32 with opposite polarities. During the charging and discharging process of the cylindrical battery 1, active ions (e.g., lithium ions) are inserted and extracted back and forth between the first electrode 31 and the second electrode 32. One of the first electrode 31 and the second electrode 32 is a positive electrode, and the other is a negative electrode.

[0061] In some embodiments, the electrode assembly 30 includes a diaphragm 33 disposed between a first electrode 31 and a second electrode 32, the diaphragm 33 insulating the first electrode 31 and the second electrode 32. The diaphragm 33 helps reduce the risk of short circuits between the positive and negative electrodes while allowing active ions to pass through.

[0062] In some embodiments, the first electrode 31 includes a first electrode body and a first tab 312, and the second electrode 32 includes a second electrode body and a second tab 322. The first electrode 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 312 is connected to the first current collector. The second electrode 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 322 is connected to the second current collector. The first tab 312 and the second tab 322 have opposite polarities, with one of the first tab 312 and the second tab 322 being a positive tab and the other a negative tab.

[0063] In some embodiments, the first tab 312 and the first current collector are integral components.

[0064] In some embodiments, the second tab 322 and the second current collector are integral components.

[0065] In some embodiments, the electrode assembly 30 includes an electrode body 34, which is a wound structure. At least a portion of a first tab 312 protrudes from the electrode body 34 toward a first end face 34a of the end cap 20 and is connected to the end cap 20.

[0066] The electrode body 34 may include a first electrode body, a second electrode body, and a separator 33 wound together. Along the radial direction of the cylindrical battery 1, a portion of the separator 33 is located between the first and second electrode bodies, and another portion of the separator 33 is located outside the outermost ring of the first or second electrode body. In other words, along the radial direction of the cylindrical battery 1, the outermost structure of the electrode body 34 is the separator 33.

[0067] The electrode body 34 includes a first end face 34a facing the end cap 20. The first tab 312 may protrude entirely from the first end face 34a toward the end cap 20, or only a part of the first tab 312 may protrude from the first end face 34a toward the end cap 20. The other part of the first tab 312 may be inserted into the electrode body 34, for example.

[0068] The first tab 312 is electrically connected to the end cap 20. The end cap 20 can form an electrode terminal of the cylindrical battery 1, which can eliminate the need for a traditional electrode terminal and simplify the structure of the cylindrical battery 1.

[0069] The first tab 312 can be directly connected to the end cap 20, or indirectly connected to the end cap 20 through other structures (such as current collectors).

[0070] In some embodiments, the cylindrical battery 1 further includes a first insulating member 40, which is disposed along the outer periphery of the electrode body 34 and connected to the electrode body 34, and covers at least a portion of the tail end 34b of the electrode body 34 along the winding direction V.

[0071] Along the radial direction of the cylindrical battery 1, the first insulating member 40 can be wound around the outside of the electrode body 34. The first insulating member 40 can be wound around the electrode body 34 less than one turn, or exactly one turn, or more than one turn.

[0072] The first insulating element 40 may be attached to the electrode body 34 by bonding, attaching or other suitable means to reduce the possibility of the first insulating element 40 falling off the electrode body 34.

[0073] The electrode body 34 includes a tail end 34b along the winding direction V, which is the final end during the winding process of the electrode body 34. The electrode body 34 also includes a start end along the winding direction V, which is the starting end during the winding process of the electrode body 34. After the electrode body 34 is unfolded in a direction opposite to the winding direction V, the tail end 34b and the start end are positioned opposite each other.

[0074] The tail end 34b of the electrode body 34 includes at least the tail end of the diaphragm 33 along the winding direction V. In some examples, the tail end of the first electrode body or the second electrode body may be flush with the tail end of the diaphragm 33, and the tail end 34b also includes the tail end of the first electrode body or the second electrode body that is flush with the tail end of the diaphragm 33.

[0075] The tail end 34b can extend along the axial direction X of the cylindrical battery 1. The first insulating member 40 can cover a portion of the tail end 34b along the axial direction X of the cylindrical battery 1, or it can completely cover the tail end 34b.

[0076] For example, the first insulating element 40 can be insulating tape, insulating film, etc.

[0077] The first insulating member 40 is used to tighten the electrode body 34 and restrict the tail end 34b of the electrode body 34 from spreading out, which helps the electrode body 34 maintain its wound structure.

[0078] In some embodiments, the cylindrical battery 1 further includes a second insulating member 50, which covers at least a portion of the end of the electrode body 34 near the first tab 312 from the outside, and a portion of the first insulating member 40 is located between the second insulating member 50 and the electrode body 34.

[0079] The end of the electrode body 34 near the first tab 312 is the end of the electrode body 34 near the first tab 312 in the axial direction X of the cylindrical battery 1.

[0080] Along the radial direction of the cylindrical battery 1, a second insulating member 50 is disposed on the outer side of the electrode body 34. In some examples, the second insulating member 50 may cover the entire end of the electrode body 34 near the first tab 312. In other examples, the second insulating member 50 may only cover a portion of the end of the electrode body 34 near the first tab 312. For example, along the axial direction X of the cylindrical battery 1, the second insulating member 50 is located on the side of the first end face 34a facing away from the end cap 20 and is spaced apart from the first end face 34a.

[0081] Along the radial direction of the cylindrical battery 1, a portion of the first insulating member 40 is located between the second insulating member 50 and the electrode body 34, and the second insulating member 50 covers a portion of the first insulating member 40.

[0082] Along the radial direction of the cylindrical battery 1, the second insulating member 50 may be wound around a portion of the outer side of the electrode body 34 and a portion of the outer side of the first insulating member 40. The second insulating member 50 may be wound around the electrode body 34 and the first insulating member 40 less than one turn, or exactly one turn, or more than one turn.

[0083] Optionally, the second insulating member 50 has a first starting end 50a and a first ending end 50b along its own winding direction, and the portion of the second insulating member 50 near the first starting end 50a and the portion near the first ending end 50b are overlapped.

[0084] The second insulating member 50 can be connected to either the first insulating member 40 or the electrode body 34, or it can be connected to both the first insulating member 40 and the electrode body 34.

[0085] The second insulating element 50 may be attached to the electrode body 34 by bonding, attaching or other suitable means.

[0086] The second insulating element 50 may be attached to the first insulating element 40 by adhesive, attachment or other suitable means.

[0087] For example, the second insulating element 50 can be insulating tape, insulating film, etc.

[0088] The second insulating member 50 can constrain the electrode body 34 near the end of the first tab 312 and the first insulating member 40 along the radial direction of the cylindrical battery 1. On the one hand, it can improve the tightness of the contact interface between the electrode and the separator 33, which is beneficial to improve the ion transport and embedding effect. On the other hand, it can also enhance the structural stability of the electrode assembly 30.

[0089] In some embodiments, the cylindrical battery 1 further includes a third insulating member 60, which covers the first tab 312 from the outside. At least a portion of the second insulating member 50 is located between the electrode body 34 and the third insulating member 60. In the axial direction X of the cylindrical battery 1, a portion of the third insulating member 60 is located between the first tab 312 and the end cap 20.

[0090] In some embodiments, the third insulating member 60 and the first insulating member 40 have a partially overlapping area in the radial direction of the cylindrical battery 1. The third insulating member 60 can indirectly constrain the first insulating member 40 through the second insulating member 50, which is beneficial to further enhance the structural stability of the electrode assembly 30.

[0091] The third insulating member 60 may include a first insulating portion 61 and a second insulating portion 62. The first insulating portion 61 is disposed between the first electrode tab 312 and the end cap 20 and covers a portion of the first electrode tab 312. The second insulating portion 62 is disposed along the outer periphery of the electrode body 34 and the second insulating member 50. At least a portion of the second insulating member 50 is located between the electrode body 34 and the second insulating portion 62.

[0092] In some embodiments, the second insulating portion 62 and the first insulating member 40 have a partially overlapping area in the radial direction of the cylindrical battery 1. This is beneficial for further enhancing the structural stability of the electrode assembly 30.

[0093] The first insulating portion 61 can be bent relative to the second insulating portion 62 toward the central axis a of the cylindrical battery 1.

[0094] Along the axial direction X of the cylindrical battery 1, the first insulating part 61 is located on the side of the first tab 312 facing the end cover 20. The first insulating part 61 can insulate and isolate the first tab 312 from the housing 10, reducing the risk of short circuit.

[0095] Along the radial direction of the cylindrical battery 1, the second insulating portion 62 is located outside the electrode body 34 and the second insulating member 50. The second insulating portion 62 may cover at least a portion of the end of the electrode body 34 near the first tab 312 from the outside, and cover at least a portion of the second insulating member 50 from the outside.

[0096] In some examples, the second insulating portion 62 completely covers the second insulating member 50 from the outside, and the second insulating member 50 is not exposed on the outside of the second insulating portion 62. In other examples, the second insulating portion 62 covers a portion of the second insulating member 50 from the outside, and another portion of the second insulating member 50 may be exposed on the outside of the second insulating portion 62.

[0097] Along the radial direction of the cylindrical battery 1, the second insulating portion 62 may be wound around a portion of the outer side of the electrode body 34 and at least a portion of the outer side of the second insulating member 50. The second insulating portion 62 may be wound around the electrode body 34 and the second insulating member 50 less than one turn, or exactly one turn, or more than one turn.

[0098] The first insulating portion 61 can be an annular structure surrounding the central axis a of the cylindrical battery 1. A portion of the first insulating portion 61 can be overlapped along the axial direction X of the cylindrical battery 1.

[0099] The third insulating member 60 may be connected to part or all of the first tab 312, the second insulating member 50 and the electrode body 34 by adhesive, attachment or other suitable means.

[0100] For example, the third insulating element 60 can be insulating tape, insulating film, etc.

[0101] The third insulating member 60 covers part of the first electrode tab 312 and at least part of the second insulating member 50. The third insulating member 60 can insulate and isolate the first electrode tab 312 from the housing 10, reducing the risk of short circuit. It can also constrain the electrode body 34 and the second insulating member 50 radially along the cylindrical battery 1, which is beneficial to further improve the structural stability of the electrode assembly 30, further improve the tightness of the contact interface between the electrode and the separator 33, and improve the ion transport and embedding effect.

[0102] In this embodiment, by sequentially covering the outer side of the electrode body 34 with a first insulating member 40, a second insulating member 50, and a third insulating member 60, the electrode body 34 can be subjected to multiple constraints, which is beneficial to improving the tightness and structural stability of the winding of the electrode body 34 and improving the winding effect of the electrode assembly 30.

[0103] In some embodiments, along the direction from the electrode assembly 30 to the end cap 20, the second insulating member 50 extends beyond the first insulating member 40, and the portion of the second insulating member 50 extending beyond the first insulating member 40 is connected to the electrode body 34.

[0104] Along the axial direction X of the cylindrical battery 1, the end of the first insulating member 40 near the first tab 312 is located on the side of the first end face 34a away from the end cover 20, and the first insulating member 40 only covers a part of the electrode body 34.

[0105] The electrode body 34 may include a first portion 341 covered by a first insulating member 40, and a second portion 342 disposed between the first portion 341 and the first tab 312. The first insulating member 40 is disposed along the outer periphery of the first portion 341. The second portion 342 is not covered by the first insulating member 40, and the portion of the second insulating member 50 extending beyond the first insulating member 40 is connected to the second portion 342.

[0106] The portion of the second insulating member 50 that extends beyond the first insulating member 40 may be connected to the electrode body 34 by adhesive bonding or other suitable means.

[0107] Along the axial direction X of the cylindrical battery 1, the end of the second insulating member 50 near the first tab 312 is closer to the end cap 20 than the end of the first insulating member 40 near the first tab 312. On one hand, the second insulating member 50 can cover at least a portion of the end of the first insulating member 40 near the first tab 312, making it less prone to unraveling or loosening. On the other hand, the second insulating member 50 can be directly connected to the electrode body 34, which helps reduce the risk of the second insulating member 50 detaching due to the influence of the first insulating member 40. The embodiments of this application further improve the tightness of the winding and the structural stability of the electrode body 34.

[0108] In some embodiments, along the direction from the electrode assembly 30 to the end cap 20, the distance d1 between the end of the first insulating member 40 near the end cap 20 and the first end face 34a is 1mm-3mm.

[0109] Optionally, the distance d1 between the end of the first insulating member 40 near the end cap 20 and the first end face 34a can be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, or any value between any two of these.

[0110] If d1 is too small, too much of the electrode body 34 will be covered by the first insulating member 40, affecting the radial dimension of the end of the electrode body 34 near the first tab 312 and affecting the housing quality; if d1 is too large, too much of the end of the electrode body 34 near the first tab 312 will not be covered by the first insulating member 40, affecting the structural stability of the electrode body 34.

[0111] In this embodiment, the distance d1 between the end of the first insulating member 40 near the end cap 20 and the first end face 34a is set to 1mm-3mm. This is beneficial to reducing the impact on the radial dimension of the end of the electrode body 34 near the first tab 312 and to improving the structural stability of the electrode body 34.

[0112] In some embodiments, the second insulating member 50 does not extend beyond the first end face 34a in the direction from the electrode assembly 30 to the end cap 20.

[0113] In some examples, along the axial direction X of the cylindrical battery 1, the end of the second insulating member 50 near the first tab 312 may be approximately flush with the first end face 34a; in other words, the second insulating member 50 may just cover the entire second portion 342.

[0114] In other examples, along the axial direction X of the cylindrical battery 1, the end of the second insulating member 50 near the first tab 312 is located on the side of the first end face 34a facing away from the end cap 20. A portion of the second portion 342 is not covered by the second insulating member 50.

[0115] The second insulating member 50 does not extend beyond the first end face 34a, which helps to reduce the possibility of interference between the second insulating member 50 and the first tab 312, and reduces the interference of the second insulating member 50 on the flattening or smoothing operation of the first tab 312.

[0116] In some embodiments, portions of the second insulating member 50 are arranged to overlap radially with the cylindrical battery 1.

[0117] The second insulating member 50 can be wound around the outside of the electrode body 34 and the first insulating member 40 along the circumference of the cylindrical battery 1, and the second insulating member 50 is wound around the electrode body 34 and the first insulating member 40 more than one turn. The second insulating member 50 has a starting end and a ending end along its own winding direction, and the portion of the second insulating member 50 near its own starting end and the portion near its own ending end are overlapped.

[0118] The overlapping portions of the second insulating element 50 can be connected to each other by adhesive or other suitable means.

[0119] Along the radial direction of the cylindrical battery 1, the overlapping portion of the second insulating member 50 has a double-layer structure, and the non-overlapping portion has a single-layer structure.

[0120] The partial overlap of the second insulating member 50 strengthens the connection between the second insulating member 50 and the electrode body 34, as well as the connection between the second insulating member 50 and the first insulating member 40, improving the installation stability of the second insulating member 50. Furthermore, the second insulating member 50 can wrap around the electrode body 34 and the first insulating member 40 from the outside, which not only reduces the assembly difficulty of the second insulating member 50, but also constrains the electrode body 34 and the first insulating member 40, helping to tightly wrap them and reducing the possibility of the second insulating member 50 coming apart.

[0121] In some embodiments, a gap 40c is provided between the two ends of the first insulating member 40 along the circumferential direction of the cylindrical battery 1. In other words, there is no overlapping portion of the first insulating member 40 along the radial direction of the cylindrical battery 1, and a portion of the electrode body 34 can be exposed to the outside of the first insulating member 40 through the gap 40c.

[0122] Along the circumference of the cylindrical battery 1, the first insulating member 40 has a first end 40a and a second end 40b, which are spaced apart to form a gap 40c between them.

[0123] The first insulating member 40 can be wound around the outside of the electrode body 34 along the circumference of the cylindrical battery 1. The first end 40a and the second end 40b are the starting end and the ending end of the first insulating member 40 along its own winding direction, respectively. The first insulating member 40 is wound around the electrode body 34 less than one turn.

[0124] During use of the cylindrical battery 1, the electrode assembly 30 will expand. The gap 40c formed between the two ends of the first insulating member 40 can provide expansion space for the electrode assembly 30, which helps the electrode assembly 30 release expansion force and reduces safety risks.

[0125] In some embodiments, the gap 40c has a circumferential dimension of less than or equal to 1 mm along the cylindrical battery 1.

[0126] Optionally, the circumferential dimension of the gap 40c along the cylindrical battery 1 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, or any value between any two of these.

[0127] The gap 40c is an arc-shaped gap extending circumferentially along the cylindrical battery 1, and its dimension along the circumferential direction is the arc length of the gap 40c along the circumferential direction of the cylindrical battery 1. The arc length of the gap 40c can be calculated by calculating the difference between the outer diameter of the electrode body 34 and the unfolded length of the first insulating member 40. Both the outer diameter of the electrode body 34 and the unfolded length of the first insulating member 40 can be obtained by taking the average of five measurements with a micrometer.

[0128] If the gap 40c is too large, the first insulating member 40 will have a weaker effect in covering and constraining the electrode body 34, which is not conducive to limiting the expansion of the electrode body 34 and maintaining the tightness and stability of the winding structure of the electrode body 34. In this embodiment, the gap 40c is set to be less than or equal to 1 mm. This allows the gap 40c to be minimized while ensuring that the electrode assembly 30 can release the expansion force through the gap 40c. This helps to limit the expansion of the electrode body 34 and improves the tightness and stability of the winding structure of the electrode body 34.

[0129] In some embodiments, the elongation of the first insulating member 40 is greater than the elongation of the second insulating member 50.

[0130] Under the same tensile force, the first insulating member 40 is stretched to a greater extent than the second insulating member 50.

[0131] The first insulating member 40 has a relatively large elongation rate. Under the expansion of the electrode body 34, the first insulating member 40 can be appropriately extended within a certain range, so that the electrode body 34 expands within a suitable range, which helps to reduce safety risks.

[0132] The second insulating member 50 can constrain the end of the electrode body 34 near the first tab 312 and the portion of the first insulating member 40 near the first tab 312. The elongation of the second insulating member 50 is relatively small, which can limit the expansion of the end of the electrode body 34 near the first tab 312 and the expansion of the portion of the first insulating member 40 near the first tab 312 to a relatively large extent, which is beneficial to improving the tightness and stability of the end of the electrode body 34 near the first tab 312.

[0133] The combination of the first insulating member 40 and the second insulating member 50 allows the portion of the electrode body 34 covered only by the first insulating member 40 to expand within a suitable range, while also providing greater restriction on the end of the electrode body 34 near the first tab 312. This balances the safety of the cylindrical battery 1 with the tightness of the winding and the structural stability of the electrode assembly 30.

[0134] In some embodiments, the tensile strength of the second insulating member 50 is greater than the tensile strength of the first insulating member 40.

[0135] The second insulating element 50 can withstand a tensile strength greater than that of the first insulating element 40.

[0136] The first insulating component 40 has relatively low tensile strength. Under the expansion of the electrode body 34, the first insulating component 40 is more easily stretched, so that the electrode body 34 expands within a suitable range, which helps to reduce safety risks.

[0137] The second insulating member 50 has relatively high tensile strength and is not easily stretched or deformed. It can limit the expansion of the end of the electrode body 34 near the first tab 312 and the expansion of the part of the first insulating member 40 near the first tab 312 to a relatively large extent, which is beneficial to improving the tightness and stability of the end of the electrode body 34 near the first tab 312.

[0138] The combination of the first insulating member 40 and the second insulating member 50 allows the portion of the electrode body 34 covered only by the first insulating member 40 to expand within a suitable range, while also providing greater restriction on the end of the electrode body 34 near the first tab 312. This balances the safety of the cylindrical battery 1 with the tightness of the winding and the structural stability of the electrode assembly 30.

[0139] In some embodiments, the material of the first insulating member 40 includes polyurethane, which has good insulation and ductility.

[0140] In some embodiments, the material of the second insulating member 50 includes polyethylene terephthalate, which has good insulation and resistance to electrolyte corrosion.

[0141] In some embodiments, along the direction from the end cap 20 to the electrode assembly 30, the end of the second insulator 50 away from the end cap 20 extends beyond the third insulator 60.

[0142] Along the axial direction X of the cylindrical battery 1, the end of the second insulating member 50 away from the end cap 20 is further away from the first end face 34a than the end of the third insulating member 60 away from the end cap 20.

[0143] When assembling the third insulating member 60, the second insulating portion 62 of the third insulating member 60 can first cover the outer side of the end of the second insulating member 50 and the electrode body 34 near the first tab 312, and then the first insulating portion 61 can be bent in the direction close to the central axis a of the cylindrical battery 1, so that the first insulating portion 61 covers the first tab 312. During the bending process of the first insulating portion 61, the third insulating member 60 may exert a pulling force on the structure connected to the second insulating portion 62.

[0144] If the third insulating member 60 is directly connected to the first insulating member 40, the third insulating member 60 may pull on the first insulating member 40, causing the first insulating member 40 to stretch and deform, thus weakening its binding effect on the electrode body 34.

[0145] The end of the second insulating member 50 that is away from the end cap 20 extends beyond the third insulating member 60, which can reduce the possibility of the third insulating member 60 being directly connected to the first insulating member 40, reduce the risk of the first insulating member 40 being deformed due to the third insulating member 60 pulling the first insulating member 40, and help the first insulating member 40 to more tightly cover the electrode body 34.

[0146] In some embodiments, along the direction from the end cap 20 to the electrode assembly 30, the end of the second insulating member 50 away from the end cap 20 extends beyond the third insulating member 60 by a dimension d2 of less than or equal to 1.5 mm.

[0147] The dimension d2 of the end of the second insulating member 50 away from the end cap 20 extending beyond the third insulating member 60 can be 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, or any value between any two of these.

[0148] The dimension d2 can be the distance in the axial direction X of the cylindrical battery 1 between the end of the second insulating member 50 away from the end cap 20 and the end of the third insulating member 60 away from the end cap 20.

[0149] If dimension d2 is too large, the dimension of the second insulating member 50 along the axial direction X of the cylindrical battery 1 will be relatively large, and the area of ​​the second insulating member 50 covering the first insulating member 40 will be relatively large, which is not conducive to the first insulating member 40 releasing the expansion force through extension and deformation; or, if the dimension of the second insulating part 62 of the third insulating member 60 along the axial direction X of the cylindrical battery 1 will be relatively small, the contact area between the second insulating part 62 and the electrode body 34 and the second insulating member 50 will be small, and it will be easy to detach from the electrode body 34 and the second insulating member 50, which is not conducive to tightly wrapping the electrode body 34 and the second insulating member 50.

[0150] In this embodiment, the dimension d2 of the end of the second insulating member 50 away from the end cap 20 extending beyond the third insulating member 60 is set to be less than or equal to 1.5 mm. This is beneficial for the extension and deformation of the first insulating member 40 and the moderate expansion of the electrode body 34, and can also improve the tightness and stability of the third insulating member 60 covering the electrode body 34 and the second insulating member 50, thereby reducing the risk of the third insulating member 60 falling off.

[0151] In some embodiments, the second insulating portion 62 surrounds the first insulating portion 61. A portion of the first insulating portion 61 overlaps along the axial direction X of the cylindrical battery 1, and a portion of the second insulating portion 62 overlaps along the radial direction of the cylindrical battery 1.

[0152] The third insulating member 60 can be wound around the outside of the first tab 312, the electrode body 34, and the second insulating member 50 along the circumference of the cylindrical battery 1. The third insulating member 60 is wound around the first tab 312, the electrode body 34, and the second insulating member 50 more than one turn. The third insulating member 60 has a second starting end 60a and a second ending end 60b along its own winding direction. The portion of the third insulating member 60 near the second starting end 60a and the portion near the second ending end 60b are overlapped.

[0153] The overlapping portions of the third insulating element 60 can be connected to each other by adhesive or other suitable means.

[0154] Along the radial direction of the cylindrical battery 1, the overlapping portion of the third insulating element 60 has a double-layer structure, and the non-overlapping portion has a single-layer structure.

[0155] The partial overlap of the first insulating portion 61 and the partial overlap of the second insulating portion 62 strengthens the connection between the third insulating member 60 and the first tab 312, the electrode body 34, and the second insulating member 50, improving the installation stability of the third insulating member 60. Furthermore, it helps reduce the assembly difficulty of the third insulating member 60. The first insulating portion 61 effectively insulates the first tab 312 and the housing 10, improving the insulation effect. In the radial direction of the cylindrical battery 1, the second insulating portion 62 constrains the electrode body 34 and the second insulating member 50, effectively wrapping the electrode body 34 and the second insulating member 50 tightly, reducing the possibility of the third insulating member 60 coming apart.

[0156] In some embodiments, the melting point of the third insulating member 60 is greater than the melting point of the second insulating member 50.

[0157] In some embodiments, the melting point of the third insulating member 60 is greater than the melting point of the first insulating member 40.

[0158] The melting points of the first insulating element 40 and the second insulating element 50 may be the same or different.

[0159] In some embodiments, the material of the third insulating element 60 includes polyimide, which has good insulation properties, resistance to electrolyte corrosion, and high temperature resistance.

[0160] A portion of the third insulating member 60 is used to cover the first electrode tab 312, and another portion of the third insulating member 60 is close to the first electrode tab 312. The current density of the electrode assembly 30 is relatively high near the first electrode tab 312, resulting in relatively large heat generation and a relatively high temperature. The melting point of the third insulating member 60 is relatively high, which can withstand higher temperatures and reduce the risk of the third insulating member 60 melting due to heat, leading to insulation failure.

[0161] In some embodiments, the thickness of the third insulating member 60 is greater than the thickness of the second insulating member 50.

[0162] The thickness of the third insulating element 60 can be the same as or different from the thickness of the first insulating element 40.

[0163] The thickness of the first insulating element 40 may be greater than the thickness of the second insulating element 50.

[0164] Optionally, the thickness of the third insulating member 60 may be greater than or equal to 0.05 mm. The thickness of the second insulating member 50 may be 0.01 mm to 0.05 mm. The thickness of the first insulating member 40 may be 0.03 mm to 0.07 mm.

[0165] The first tab 312 can be formed by a cutting process, and the cut edges of the first tab 312 may have burrs. The third insulating member 60 has a greater thickness, which can reduce the possibility of the third insulating member 60 being punctured by the burrs on the first tab 312, thus helping to reduce the risk of short circuit.

[0166] In some embodiments, the first insulating member 40 and the second insulating member 50 are both bonded to the electrode body 34, and the third insulating member 60 is bonded to the second insulating member 50. The bonding connection method is simple and the connection is relatively stable.

[0167] Optionally, the second insulating portion 62 of the third insulating member 60 is bonded to the second insulating member 50. The second insulating portion 62 may also be bonded to the electrode body 34.

[0168] The first insulating portion 61 of the third insulating member 60 can be bonded to the first tab 312, or it can be attached only to the first tab 312.

[0169] Optionally, the second insulating member 50 may also be bonded to the first insulating member 40.

[0170] For example, the first insulating member 40 may be insulating adhesive paper, and the inner surface of the first insulating member 40 is provided with adhesive along the radial direction of the cylindrical battery 1.

[0171] For example, the second insulating member 50 may be an insulating tape, and adhesive is provided on the inner surface of the second insulating member 50 along the radial direction of the cylindrical battery 1.

[0172] For example, the third insulating member 60 may be an insulating tape, and adhesive is provided on the inner surface of the third insulating member 60 along the radial direction of the cylindrical battery 1.

[0173] In some embodiments, the first insulating member 40 covers the middle portion of the electrode body 34 along the axial direction X of the cylindrical battery 1.

[0174] The middle part of the electrode body 34 along the axial direction X of the cylindrical battery 1 refers to the middle portion of the electrode body 34 along the axial direction X of the cylindrical battery 1. This middle part of the electrode body 34 includes at least the center of the electrode body 34 along the axial direction X of the cylindrical battery 1.

[0175] The first insulating member 40 covers the first part 341 of the electrode body 34, and the center of the electrode body 34 along the axial direction X of the cylindrical battery 1 is located in the first part 341.

[0176] Optionally, the electrode body 34 further includes a third portion 343, which is located on the side of the first portion 341 opposite to the second portion 342. The third portion 343 is not covered by the first insulating member 40.

[0177] Along the axial direction X of the cylindrical battery 1, the dimensions of the third part 343 and the second part 342 can be the same or different.

[0178] The first insulating member 40 covers the middle part of the electrode body 34, which can provide a more balanced covering and confinement effect on the electrode body 34. This helps to reduce the risk of the electrode body 34 spreading out at both ends along the axial direction X of the cylindrical battery 1 and improves the covering effect of the first insulating member 40 on the electrode body 34.

[0179] In some embodiments, at least a portion of the second tab 322 protrudes from the second end face 34c of the electrode body 34 away from the end cap 20. The cylindrical battery 1 also includes a fourth insulating member 70 that covers at least a portion of the end of the electrode body 34 near the second tab 322 from the outside, and a portion of the first insulating member 40 is located between the fourth insulating member 70 and the electrode body 34.

[0180] The electrode body 34 includes a second end face 34c facing away from the end cap 20. The second tab 322 may protrude entirely from the second end face 34c toward the end cap 20, or only a part of the second tab 322 may protrude from the second end face 34c toward the end cap 20. The other part of the second tab 322 may be inserted into the electrode body 34, for example.

[0181] The second tab 322 can be electrically connected to the bottom wall 12, which can form an electrode terminal of the cylindrical battery 1, eliminating the need for a traditional electrode terminal and simplifying the structure of the cylindrical battery 1.

[0182] The second tab 322 can be directly connected to the bottom wall 12, or indirectly connected to the bottom wall 12 through other structures (such as current collectors).

[0183] The end of the electrode body 34 near the second tab 322 is the end of the electrode body 34 near the second tab 322 along the axial direction X of the cylindrical battery 1.

[0184] Along the radial direction of the cylindrical battery 1, a fourth insulating member 70 is disposed on the outer side of the electrode body 34. In some examples, the fourth insulating member 70 may cover the entire end of the electrode body 34 near the second tab 322. In other examples, the fourth insulating member 70 may only cover a portion of the end of the electrode body 34 near the second tab 322. For example, along the axial direction X of the cylindrical battery 1, the fourth insulating member 70 is located on the side of the second end face 34c facing away from the end cap 20 and is spaced apart from the second end face 34c.

[0185] Along the radial direction of the cylindrical battery 1, a portion of the first insulating member 40 is located between the fourth insulating member 70 and the electrode body 34, and the fourth insulating member 70 covers a portion of the first insulating member 40.

[0186] Along the radial direction of the cylindrical battery 1, the fourth insulating member 70 may be wound around a portion of the outer side of the electrode body 34 and a portion of the outer side of the first insulating member 40. The fourth insulating member 70 may be wound around the electrode body 34 and the first insulating member 40 less than one turn, or exactly one turn, or more than one turn.

[0187] The fourth insulating member 70 can be connected to either the first insulating member 40 or the electrode body 34, or it can be connected to both the first insulating member 40 and the electrode body 34.

[0188] The fourth insulating element 70 may be attached to the electrode body 34 by adhesive, attachment or other suitable means.

[0189] The fourth insulating element 70 may be attached to the first insulating element 40 by adhesive, attachment or other suitable means.

[0190] For example, the fourth insulating element 70 can be insulating tape, insulating film, etc.

[0191] The fourth insulating member 70 can constrain the electrode body 34 near the end of the second tab 322 and the first insulating member 40 along the radial direction of the cylindrical battery 1. On the one hand, it can improve the tightness of the contact interface between the electrode and the separator 33, which is beneficial to improve the ion transport and embedding effect. On the other hand, it can also enhance the structural stability of the electrode assembly 30.

[0192] In some embodiments, in the direction from the first end face 34a to the second end face 34c, the fourth insulating member 70 extends beyond the first insulating member 40, and the portion of the fourth insulating member 70 extending beyond the first insulating member 40 is connected to the electrode body 34.

[0193] Along the axial direction X of the cylindrical battery 1, the end of the first insulating member 40 near the second tab 322 is located on the side of the second end face 34c facing the end cap 20, and the first insulating member 40 only covers a part of the electrode body 34.

[0194] The portion of the fourth insulating member 70 that extends beyond the first insulating member 40 can be connected to the third portion 343 of the electrode body 34.

[0195] The portion of the fourth insulating member 70 that extends beyond the first insulating member 40 may be connected to the electrode body 34 by adhesive bonding or other suitable means.

[0196] Along the axial direction X of the cylindrical battery 1, the end of the fourth insulating member 70 near the second tab 322 is further away from the end cap 20 than the end of the first insulating member 40 near the second tab 322. On one hand, the fourth insulating member 70 can cover at least a portion of the end of the first insulating member 40 near the second tab 322, making it less prone to unraveling or loosening. On the other hand, the fourth insulating member 70 can be directly connected to the electrode body 34, which helps reduce the risk of the fourth insulating member 70 detaching due to the influence of the first insulating member 40. The embodiments of this application further improve the tightness of the winding and the structural stability of the electrode body 34.

[0197] In some embodiments, along the direction from the first end face 34a to the second end face 34c, the distance d3 between the end of the first insulating member 40 near the second end face 34c and the second end face 34c is 1mm-3mm.

[0198] Optionally, the distance d3 between the end of the first insulating member 40 near the second end face 34c and the second end face 34c can be 1 mm, 1.2 mm, 1.4 mm, 1.6 mm, 1.8 mm, 2.0 mm, 2.2 mm, 2.4 mm, 2.6 mm, 2.8 mm, 3 mm, or any value between any two of these.

[0199] If d3 is too small, too much of the electrode body 34 will be covered by the first insulating member 40, affecting the radial dimension of the end of the electrode body 34 near the second tab 322 and affecting the housing fit rate; if d3 is too large, too much of the end of the electrode body 34 near the second end face 34c will not be covered by the first insulating member 40, affecting the structural stability of the electrode body 34.

[0200] In this embodiment, the distance d3 between the end of the first insulating member 40 near the second end face 34c and the second end face 34c is set to 1mm-3mm. This is beneficial to reducing the impact on the radial dimension of the end of the electrode body 34 near the second tab 322 and to improving the structural stability of the electrode body 34.

[0201] In some embodiments, the second insulating member 50 and the fourth insulating member 70 may be symmetrically arranged about the bisecting plane of the cylindrical battery 1 along the axial direction X.

[0202] The fourth insulating member 70 may have the same structure as the second insulating member 50. The positional relationship between the fourth insulating member 70 and the first insulating member 40 is the same as that between the second insulating member 50 and the first insulating member 40, which will not be described again here.

[0203] According to a second aspect of this application, embodiments of this application also provide a method for preparing a cylindrical battery 1. The method for preparing the cylindrical battery 1 includes:

[0204] Step S10, providing an electrode assembly with a wound structure, wherein the electrode assembly 30 includes an electrode body 34 and a first tab 312, at least a portion of the first tab 312 protruding from a first end face 34a of the electrode body 34 along its own axial direction;

[0205] Step S30: Connect a first insulating member 40 to the outer periphery of the electrode body 34 and make the first insulating member 40 cover at least a portion of the tail end 34b of the electrode body 34 along the winding direction V.

[0206] Step S50: Cover the outer side of the end of the electrode body 34 near the first tab 312 and the outer side of a portion of the first insulating member 40 with the second insulating member 50.

[0207] In step S70, the third insulating member 60 is covered on the outside of the first tab 312 and at least a portion of the outside of the second insulating member 50.

[0208] Step S10 may specifically include winding the first electrode 31, the diaphragm 33, and the second electrode 32 to form an electrode assembly 30.

[0209] The first electrode 31 may include a first blank area uncoated with the first active material layer, and the first blank area is wound to form a first electrode tab 312. The first electrode tab 312 may be formed in any step before step S70 or between any two steps.

[0210] In some embodiments, before the third insulating member 60 is covered on the outer side of the first tab 312 and at least a portion of the outer side of the second insulating member 50, the method of preparing the cylindrical battery 1 further includes:

[0211] Step S60, knead or pat the first pole ear 312 flat;

[0212] After wrapping the third insulating member 60 around the outer side of the first electrode 312 and at least a portion of the outer side of the second insulating member 50, the method for manufacturing the cylindrical battery 1 further includes:

[0213] In step S80, a portion of the third insulating member 60 is folded over to the side of the first electrode tab 312 that is axially opposite to the electrode body 34.

[0214] In step S60, flattening the first tab 312 means that the first blank area is formed by winding to form the first tab 312, and then the first tab 312 is flattened. Specifically, the first tab 312 formed by winding the first blank area can be pressed from the outside to the inside along the radial direction of the cylindrical battery 1.

[0215] In step S60, flattening the first tab 312 means that the first blank area is formed into the first tab 312 by winding, and then the first tab 312 is flattened. Specifically, the first tab 312 formed by winding the first blank area can be flattened along the axial direction X of the cylindrical battery 1.

[0216] In the embodiments of this application, there is no particular restriction on the order of step S60 and any of steps S20 to S50. Step S60 can be performed before or after any step after step S10.

[0217] In this embodiment, the first tab 312 is flattened or patted before being covered with the third insulating member 60. This reduces interference or influence between the flattening or patting operations of the third insulating member 60 and the first tab 312, thus improving manufacturing efficiency. After covering the third insulating member 60, a portion of the third insulating member 60 is further folded to the side of the first tab 312 facing away from the electrode body 34 along the axial direction X. This portion of the third insulating member 60 can cover the first tab 312, insulating and isolating it from the housing 10, thus reducing the risk of short circuits.

[0218] According to a third aspect of this application, embodiments of this application also provide a battery module 100, which includes a plurality of cylindrical batteries 1 provided according to any embodiment of this application.

[0219] In some embodiments, the battery module 100 further includes a plurality of busbars 2. The busbars 2 are connected to cylindrical batteries 1. At least two cylindrical batteries 1 can be connected in series or in parallel via the busbars 2.

[0220] In some embodiments, the battery module 100 further includes a support 3 having a receiving cavity in which a plurality of cylindrical batteries 1 are disposed.

[0221] This application also provides an electrical device 1000, which includes a battery module 100 provided in any embodiment of this application. The battery module 100 can provide electrical energy for the operation of the electrical device 1000.

[0222] The electrical device 1000 in this application embodiment can be a portable device, a laptop computer, an electric toy, a drone, a power tool, an energy storage system, etc. Power tools include metal cutting power tools, cleaning tools, etc., such as electric drills, electric wrenches, vacuum cleaners, robot vacuum cleaners, etc. This application embodiment does not impose any special limitations on the above-mentioned electrical device.

[0223] Although this application has been described with reference to preferred embodiments, various modifications can be made thereto and components can be replaced with equivalents without departing from the scope of this application. In particular, the technical features mentioned in the various embodiments can be combined in any manner, provided there is no structural conflict. This 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, comprising: The shell has an opening; End cap, connected to the housing and covering the opening; An electrode assembly includes an electrode body and a first tab, wherein the electrode body has a wound structure and at least a portion of the first tab protrudes from a first end face of the electrode body toward the end cap; A first insulating member is disposed along the outer periphery of the electrode body and connected to the electrode body, the first insulating member covering at least a portion of the tail end of the electrode body along the winding direction; The second insulating member covers at least a portion of the end of the electrode body near the first tab, and a portion of the first insulating member is located between the second insulating member and the electrode body; as well as A third insulating element covers the first tab, at least a portion of the second insulating element is located between the electrode body and the third insulating element, and a portion of the third insulating element is located between the first tab and the end cap in the axial direction of the cylindrical battery.

2. The cylindrical battery according to claim 1, wherein, Along the direction from the electrode assembly to the end cap, the second insulating member extends beyond the first insulating member, and the portion of the second insulating member extending beyond the first insulating member is connected to the electrode body.

3. The cylindrical battery according to claim 1 or 2, wherein, Along the direction from the electrode assembly to the end cap, the distance between the end of the first insulating member near the end cap and the first end face is 1mm-3mm.

4. The cylindrical battery according to any one of claims 1-3, wherein, Along the direction from the electrode assembly to the end cap, the second insulating member does not extend beyond the first end face.

5. The cylindrical battery according to any one of claims 1-4, wherein, A portion of the second insulating member overlaps radially with the cylindrical battery.

6. The cylindrical battery according to any one of claims 1-5, wherein, The first insulating member has a gap between its two ends along the circumference of the cylindrical battery.

7. The cylindrical battery according to claim 6, wherein, The gap is less than or equal to 1 mm along the circumferential direction.

8. The cylindrical battery according to any one of claims 1-7, wherein, The elongation of the first insulating element is greater than the elongation of the second insulating element; and / or, The tensile strength of the second insulating component is greater than that of the first insulating component.

9. The cylindrical battery according to any one of claims 1-8, wherein, Along the direction from the end cap toward the electrode assembly, the end of the second insulator away from the end cap extends beyond the third insulator.

10. The cylindrical battery according to claim 9, wherein, Along the direction from the end cap toward the electrode assembly, the end of the second insulator away from the end cap extends beyond the third insulator by less than or equal to 1.5 mm.

11. The cylindrical battery according to any one of claims 1-10, wherein, The third insulating member includes a first insulating portion and a second insulating portion. The first insulating portion is disposed between the first electrode tab and the end cap and covers a portion of the first electrode tab. The second insulating portion surrounds the first insulating portion. At least a portion of the second insulating member is located between the electrode body and the second insulating portion. A portion of the first insulating portion overlaps along the axial direction of the cylindrical battery, and a portion of the second insulating portion overlaps along the radial direction of the cylindrical battery.

12. The cylindrical battery according to any one of claims 1-11, wherein, The melting point of the third insulating element is greater than that of the second insulating element; and / or the melting point of the third insulating element is greater than that of the first insulating element.

13. The cylindrical battery according to any one of claims 1-12, wherein, The thickness of the third insulating element is greater than the thickness of the second insulating element.

14. The cylindrical battery according to any one of claims 1-13, wherein, The first insulating member and the second insulating member are both bonded to the electrode body, and the third insulating member is bonded to the second insulating member.

15. The cylindrical battery according to any one of claims 1-14, wherein, The first insulating element covers the middle portion of the electrode body along the axial direction.

16. The cylindrical battery according to any one of claims 1-15, wherein, The electrode assembly further includes a second tab, at least a portion of which protrudes from the second end face of the electrode body facing away from the end cap, and the first tab and the second tab have opposite polarities; The cylindrical battery includes a fourth insulating member that covers at least a portion of the end of the electrode body near the second tab, and a portion of the first insulating member is located between the fourth insulating member and the electrode body.

17. The cylindrical battery according to claim 16, wherein, Along the direction from the first end face to the second end face, the fourth insulating member extends beyond the first insulating member, and the portion of the fourth insulating member extending beyond the first insulating member is connected to the electrode body.

18. The cylindrical battery according to claim 16 or 17, wherein, Along the direction from the first end face to the second end face, the distance between the end of the first insulating member near the second end face and the second end face is 1mm-3mm.

19. A method for preparing a cylindrical battery, comprising: An electrode assembly with a wound structure is provided, wherein the electrode assembly includes an electrode body and a first tab, at least a portion of the first tab protruding from a first end face of the electrode body along its own axial direction; A first insulating member is connected to the outer periphery of the electrode body, and the first insulating member covers at least a portion of the tail end of the electrode body along the winding direction; A second insulating member is wrapped around the outer side of the end of the electrode body near the first tab and the outer side of a portion of the first insulating member; A third insulating element is wrapped around the outside of the first tab and at least a portion of the outside of the second insulating element.

20. The preparation method according to claim 19, wherein, Before covering the outer side of the first electrode tab and at least a portion of the outer side of the second insulating member with the third insulating member, the preparation method further includes: flattening or patting the first electrode tab; After wrapping a third insulating member around the outer side of the first electrode tab and at least a portion of the outer side of the second insulating member, the preparation method further includes: A portion of the third insulating member is folded over to the side of the first tab facing away from the electrode body along the axial direction.

21. A battery module comprising a plurality of cylindrical batteries according to any one of claims 1-18.

22. An electrical device comprising the battery module according to claim 21.

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