Cylindrical battery, manufacturing method for cylindrical battery, and electric device

Abstract

A cylindrical battery (100), a manufacturing method for the cylindrical battery (100), and an electric device (1000), wherein the cylindrical battery (100) comprises a housing (10), a top cover (20), and an insulating layer (50). The housing (10) comprises a side wall (11), the side wall (11) comprising a first outer surface (112). The top cover (20) and the side wall (11) are welded to form a weld line (102), and the weld line (102) is partially located on the first outer surface (112). The insulating layer (50) comprises a first portion (51), wherein the first portion (51) covers part of the first outer surface (112); in the axial direction of the cylindrical battery (100), the first portion (51) is located on one side of the weld line (102), and the first portion (51) is separated from or connected to the weld line (102). The insulating layer (50) is arranged on the first outer surface (112) of the housing (10), and the insulating layer (50) does not cover the weld line (102), which is beneficial to reducing the size of the cylindrical battery (100) and improving the energy density of the cylindrical battery (100).

Description

Cylindrical battery, manufacturing method of cylindrical battery, and electric device TECHNICAL FIELD

[0001] The present application relates to the technical field of energy storage, and in particular to a cylindrical battery and an electric device. BACKGROUND

[0002] In the related art, a heat-shrinkable film is usually used to protect the shell of the cylindrical battery. However, the heat-shrinkable film is prone to dislocation or loosening during transportation or use, which affects the safety and reliability of the cylindrical battery.

[0003] SUMMARY

[0004] Therefore, the present application provides a cylindrical battery, a manufacturing method of the cylindrical battery, and an electric device, which are beneficial to improving the safety and reliability.

[0005] In a first aspect, the present application provides a cylindrical battery, which includes a shell, a top cover, and an insulation layer. The shell includes a side wall, and the side wall includes a first outer surface. The top cover is welded to the side wall and forms a welding line, and the welding line is partially located on the first outer surface. The insulation layer includes a first part, the first part covers part of the first outer surface, and along an axial direction of the cylindrical battery, the first part is located on one side of the welding line and is separated from or connected to the welding line.

[0006] In the above embodiment, the insulation layer is beneficial to insulating and protecting the shell. The first part of the insulation layer is separated from or connected to the welding line along the axial direction, so that the insulation layer does not cover the area where the welding line is formed, which is beneficial to reserving more welding space and facilitating the formation of the welding line. The insulation layer not covering the area where the welding line is formed is also beneficial to reducing the size of the cylindrical battery and improving the energy density of the cylindrical battery. In the above embodiment, the insulation layer is provided, and the first part of the insulation layer is separated from or connected to the welding line along the axial direction, which is beneficial to reducing the possibility of the insulation layer being lifted by the welding line, improving the adhesion strength of the insulation layer and the side wall, and improving the safety and reliability of the cylindrical battery.

[0007] In one or more of the above embodiments, along a direction perpendicular to the axial direction and intersecting the axial line of the cylindrical battery, the thickness of the welding line is H1, and the thickness of the insulation layer is H2, and H2>H1.

[0008] In the above embodiment, when the thickness of the insulation layer along the direction perpendicular to the axial direction is H2, which is greater than the thickness H1 of the welding line along the direction perpendicular to the axial direction, the insulation layer is first contacted when the cylindrical battery contacts other components or other cylindrical batteries, which is beneficial to protecting the welding line and reducing the possibility of the welding line being damaged, and is beneficial to improving the safety and reliability of the cylindrical battery.

[0009] In one or more of the above embodiments, 0.02mm≤H1≤0.12mm.

[0010] In the above embodiment, 0.02mm≤H1≤0.12mm, on the one hand, it is conducive to improving the welding strength between the top cover and the side wall, and on the other hand, it does not make the volume of the welding line too large, which is conducive to reducing the occupied space of the cylindrical battery and improving the energy density of the cylindrical battery.

[0011] In one or more of the above embodiments, 0.03mm≤H2≤0.15mm.

[0012] In the above embodiment, 0.03mm≤H2≤0.15mm, on the one hand, it is conducive to improving the thickness of the insulation layer, reducing the risk of damage to the insulation layer and exposing the first outer surface, and also conducive to making the thickness of the insulation layer in the direction perpendicular to the axial direction greater than the thickness of the welding line, which is conducive to improving the safety and reliability of the cylindrical battery; on the other hand, it makes the insulation layer not too thick, which is conducive to reducing the volume and weight of the cylindrical battery and improving the energy density.

[0013] In one or more of the above embodiments, along the axial direction, the height of the welding line is W, and 0.8mm≤W≤1.2mm.

[0014] In the above embodiment, 0.8mm≤W≤1.2mm, on the one hand, it is conducive to improving the welding strength between the top cover and the side wall, and on the other hand, it does not make the volume of the welding line too large, which is conducive to reducing the occupied space of the cylindrical battery and improving the energy density of the cylindrical battery.

[0015] In one or more of the above embodiments, along the axial direction, the first part is away from the welding line, the distance between the first part and the welding line is L, and 0.5mm≤L≤5mm.

[0016] In the above embodiment, 0.5mm≤L≤5mm, on the one hand, it makes the distance between the first part and the area where the welding line is formed not too small, which is conducive to realizing that the first part is away from the welding line, conducive to the processing of the insulation layer and the welding line, and reduces the possibility that the insulation layer covers the welding line due to processing errors and the like; on the other hand, it makes the distance between the first part and the area where the welding line is formed not too large, which is conducive to improving the comprehensiveness of the insulation protection of the insulation layer to the shell.

[0017] In one or more of the above embodiments, the shell further comprises a bottom wall and a connecting wall, the connecting wall connects the side wall and the bottom wall, the bottom wall comprises a second outer surface, the connecting wall has a first connecting surface, the first connecting surface connects the first outer surface and the second outer surface, and the first part covers at least part of the first connecting surface.

[0018] In the above embodiment, the connecting wall is at the corner of the shell, which is easy to be damaged under the working conditions of vibration and falling, and the first part covers at least part of the first connecting surface in the above embodiment, which is conducive to improving the comprehensiveness of the insulation protection of the insulation layer to the shell, improving the anti-vibration and anti-falling performance of the corner of the shell, and improving the safety and reliability of the cylindrical battery.

[0019] In one or more of the above embodiments, the first portion does not exceed the second outer surface in the axial direction.

[0020] In one or more of the above embodiments, the first portion does not exceed the second outer surface in the axial direction, which is conducive to reducing the axial space occupied by the insulation layer, so that the insulation layer does not increase the height of the cylindrical battery in the axial direction, and is conducive to improving the energy density of the cylindrical battery.

[0021] In one or more of the above embodiments, the insulation layer includes a second portion, and the second portion covers an outer periphery of the second outer surface. The cylindrical battery is a cylindrical battery, and in the radial direction of the cylindrical battery, the width of the second portion is R1, and 0 < R1 ≤ 3 mm.

[0022] In one or more of the above embodiments, when 0 < R1 ≤ 3 mm, on the one hand, it is conducive to further improving the comprehensiveness of the insulation protection of the shell, and when the cylindrical battery is placed vertically, the insulation layer is in contact with the external member before the bottom wall, which is conducive to protecting the bottom wall; on the other hand, the width R1 of the second portion is not too large, which is conducive to reserving a welding area and facilitating the connection between the bottom wall and the bus bar when multiple battery cells are connected in series and / or in parallel.

[0023] In one or more of the above embodiments, the insulation layer includes a third portion, and the top cover includes a third outer surface, and the third portion covers an outer periphery of the third outer surface. The cylindrical battery is a cylindrical battery, and in the radial direction of the cylindrical battery, the width of the third portion is R2, and 0 < R2 ≤ 3 mm.

[0024] In one or more of the above embodiments, when 0 < R2 ≤ 3 mm, on the one hand, it is conducive to further improving the comprehensiveness of the insulation protection of the shell, and is conducive to protecting the top cover; on the other hand, the width R2 of the third portion is not too large, which is conducive to reserving a welding area and facilitating the connection between the top cover and the bus bar when multiple battery cells are connected in series and / or in parallel.

[0025] In one or more of the above embodiments, the first outer surface includes a rough surface, and the first portion covers at least part of the rough surface.

[0026] In one or more of the above embodiments, the rough surface allows the insulation layer to be more stably fixed to the shell, which is conducive to reducing the risk of peeling of the insulation layer and improving the stability and reliability of the cylindrical battery.

[0027] In one or more of the above embodiments, the insulation layer includes a light-cured material, which is conducive to using light-cured means to improve the stability of the connection between the insulation layer and the shell or to improve the stability of the connection between the insulation layer and the top cover.

[0028] In one or more of the above embodiments, the light-cured material includes one of polyurethane, polyacrylic acid, and polysiloxane.

[0029] In one or more of the above embodiments, the first portion is coated on the first outer surface.

[0030] In a second aspect, the application provides a manufacturing method of a cylindrical battery, comprising the following steps: welding a top cover to a side wall and forming a welding line, the welding line being partially located on a first outer surface of the side wall; processing the first outer surface of the side wall into a rough surface; coating a light-curing material on the rough surface and making the light-curing material located on one side of the welding line along an axial direction; and performing a curing process on the light-curing material to form an insulation layer.

[0031] In the above embodiments, the insulation layer on the rough surface is located on one side of the welding line along the axial direction, so that the insulation layer does not cover the area where the welding line is formed, which is beneficial to reserving more welding space and facilitating the formation of the welding line. The insulation layer not covering the area where the welding line is formed is also beneficial to reducing the size of the cylindrical battery and improving the energy density of the cylindrical battery. In the above embodiments, the insulation layer on the rough surface is located on one side of the welding line along the axial direction, which is beneficial to reducing the possibility of the insulation layer being lifted by the welding line, improving the adhesion strength of the insulation layer to the side wall, and improving the safety and reliability of the cylindrical battery.

[0032] In one or more of the above embodiments, the manufacturing method of the cylindrical battery further comprises the following steps: attaching an isolation layer on the first outer surface on the side of the welding line along the axial direction; and disposing the insulation layer on the rough surface. The isolation layer is removed to form a gap between the insulation layer and the welding line.

[0033] In the above embodiments, the isolation region separates the first portion from the welding line, which is beneficial to reducing the possibility of the insulation layer covering the welding line due to processing errors and the like.

[0034] In a third aspect, the application provides an electrical equipment comprising the cylindrical battery according to any one of the above embodiments.

[0035] In the above embodiments, the safety and reliability of the cylindrical battery are improved, which is beneficial to improving the safety and reliability of the electrical equipment.

[0036] The cylindrical battery in the application comprises a shell, a top cover, and an insulation layer. The shell comprises a side wall, and the side wall comprises a first outer surface. The top cover is welded to the side wall and forms a welding line, and the welding line is partially located on the first outer surface. The insulation layer comprises a first portion, and the first portion covers part of the first outer surface. Along the axial direction of the cylindrical battery, the first portion is located on one side of the welding line, and the first portion is separated from or connected to the welding line. The insulation layer does not cover the area where the welding line is formed, which is beneficial to reserving more welding space and facilitating the formation of the welding line. The insulation layer not covering the area where the welding line is formed is also beneficial to reducing the size of the cylindrical battery and improving the energy density of the cylindrical battery. The first portion of the insulation layer is separated from or connected to the welding line along the axial direction, which is beneficial to reducing the possibility of the insulation layer being lifted by the welding line, improving the adhesion strength of the insulation layer to the side wall, and improving the safety and reliability of the cylindrical battery. BRIEF DESCRIPTION OF DRAWINGS

[0037] Fig. 1 is a schematic diagram of a structure of a cylindrical battery according to an embodiment of the present application.

[0038] Fig. 2 is a partial cross-sectional view of a structure of a cylindrical battery according to an embodiment of the present application.

[0039] Fig. 3 is a top view of the cylindrical battery of Fig. 2.

[0040] Fig. 4 is a bottom view of the cylindrical battery of Fig. 2.

[0041] Fig. 5 is a partial cross-sectional view of a structure of a cylindrical battery according to another embodiment of the present application.

[0042] Fig. 6 is a top view of the structure of the cylindrical battery of Fig. 5.

[0043] Fig. 7 is an enlarged view of a portion of Fig. 2.

[0044] Fig. 8 is a partial cross-sectional view of a structure of a cylindrical battery according to still another embodiment of the present application.

[0045] Fig. 9 is a cross-sectional view of a top cover and a third portion according to an embodiment of the present application.

[0046] Fig. 10 is a schematic diagram of an electrical device according to an embodiment of the present application.

[0047] Main element symbol explanation Columnar battery 100 Shell 10 Side wall 11 First inner surface 111 First outer surface 112 Rough surface 113 Bottom wall 12 Second inner surface 121 Second outer surface 122 Connecting wall 13 First connecting surface 131 Second connecting surface 132 Top cover 20 Third outer surface 201 Containing cavity 101 Welding line 102 Pole column 40 Insulating layer 50 First part 51 Second part 52 Third part 53 Axial direction X Radial direction Y Axis L0 Device main body 200 Electrical device 1000 DETAILED DESCRIPTION

[0048] The technical solutions in the embodiments of the present application will be described below with reference to 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 the embodiments.

[0049] It should be noted that unless otherwise explicitly specified and limited, the terms "mount", "connect", "connection", "fix", and the like should be understood in a broad sense, for example, can be fixed connection, can also be detachable connection, or integrally connected; can be mechanical connection, can be insulating connection, or can be electrical connection. When a component is considered to be "connected" to another component, it can be directly connected to another component or can exist simultaneously with a middle component. When a component is considered to be "provided" on another component, it can be directly provided on another component or can exist simultaneously with a middle component.

[0050] The terms "top", "bottom" and similar expressions used herein are for illustrative purposes only.

[0051] Unless otherwise specified, the term "a plurality of" used herein refers to two or more.

[0052] The terms "first", "second", and the like are only used to distinguish different objects, and cannot be understood as indicating or implying relative importance or implying the number, specific order or primary and secondary relationship of the indicated technical features.

[0053] The term "vertical" is used to describe the ideal state between two components. In the actual production or use state, there can be an approximate vertical state between the two components. For example, in combination with numerical description, vertical can refer to the included angle between two straight lines within the range of 90°±10°, vertical can also refer to the dihedral angle between two planes within the range of 90°±10°, and vertical can also refer to the included angle between a straight line and a plane within the range of 90°±10°.

[0054] It should be noted that when a parameter is greater than, equal to, or less than an endpoint value, it is understood that the endpoint value allows a tolerance of ±5%.

[0055] It should be noted that the dimensions of the structures shown in the drawings are given for better understanding and more convenient description, and the application is not limited to the dimensions shown in the drawings. In order to make the application clear, the elements irrelevant to the description are omitted from the details of the specification.

[0056] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs. The terms used in the specification of the present application herein are only for the purpose of describing specific embodiments and are not intended to limit the present application.

[0057] In the related art, a heat-shrinkable film is usually used to insulate and protect the shell of the cylindrical battery, but the heat-shrinkable film is prone to dislocation or loosening during transportation / use, etc., affecting the safety and reliability of the cylindrical battery.

[0058] The application provides a cylindrical battery, which comprises a shell and an insulation layer. The shell comprises a side wall and a bottom wall connected to each other, the side wall comprises a first inner surface and a first outer surface, and the first inner surface is located inside the first outer surface in the axial direction of the cylindrical battery. The top cover and the bottom wall are arranged in the axial direction, the top cover is welded to the side wall and forms a welding line, and the top cover and the shell enclose a containing cavity. The insulation layer comprises a first part, the first part is arranged on the first outer surface, the first part is located on one side of the welding line in the axial direction, and the first part is separated from or connected to the welding line.

[0059] The insulation layer is beneficial to insulating and protecting the shell, the first part of the insulation layer is separated from or connected to the welding line in the axial direction, the area where the welding line is formed is not covered by the insulation layer, more welding space is reserved, and the formation of the welding line is facilitated. The area where the welding line is formed is not covered by the insulation layer, and the size of the cylindrical battery is reduced, and the energy density of the cylindrical battery is improved. In the above embodiment, the insulation layer is arranged, and the first part of the insulation layer is separated from or connected to the welding line in the axial direction, the possibility that the insulation layer is lifted by the welding line is reduced, the adhesion strength of the insulation layer and the side wall is improved, and the safety and reliability of the cylindrical battery are improved.

[0060] Some embodiments of the application will be described below in conjunction with the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0061] Please refer to FIG. 1 and FIG. 2, the application provides a cylindrical battery 100, which comprises a shell 10 and a top cover 20, the top cover 20 is connected to the shell 10 and forms a containing cavity 101.

[0062] In some embodiments, please refer to FIG. 2 to FIG. 4, the shell 10 comprises a side wall 11 and a bottom wall 12 connected to each other, the top cover 20 and the bottom wall 12 are arranged in the axial direction X of the cylindrical battery 100 (for the convenience of description, the axial direction X of the cylindrical battery 100 is hereinafter referred to as the axial direction X), and the top cover 20 is welded to the side wall 11 and forms a welding line 102.

[0063] In some embodiments, please refer to FIG. 2, FIG. 5 and FIG. 6, the side wall 11 comprises a first inner surface 111 and a first outer surface 112, and the first inner surface 111 is located inside the first outer surface 112 in the axial direction X. The welding line 102 is partially located on the first outer surface 112.

[0064] In some embodiments, please refer to FIG. 2, FIG. 5 to FIG. 7, the bottom wall 12 comprises a second inner surface 121 and a second outer surface 122 arranged oppositely, the second inner surface 121 is located inside the containing cavity 101, and the second outer surface 122 is located outside the containing cavity 101.

[0065] In some embodiments, the shell 10 is cylindrical.

[0066] In some embodiments, please refer to Figures 1 and 2, the cylindrical battery 100 is a cylindrical battery and the casing 10 is cylindrical.

[0067] In other embodiments, the cylindrical battery 100 is a prismatic battery 100 or a square-cylindrical battery 100. The cross-section of the square-cylindrical battery 100 is approximately "U"-shaped, and the corners are rounded.

[0068] In some embodiments, the housing 10 is an aluminum housing. The housing 10 is made of aluminum, which has good ductility, making it advantageous for manufacturing batteries with longer lengths (e.g., exceeding 80 mm).

[0069] In some embodiments, the housing 10 is a steel housing. The steel housing has high strength, which is beneficial for manufacturing batteries with a thinner housing (e.g., 0.15mm-0.3mm).

[0070] In some embodiments, the cylindrical battery 100 includes an electrode assembly (not shown) and an electrolyte (not shown), both of which are disposed within a receiving cavity 101.

[0071] In some embodiments, the electrode assembly includes a positive electrode, a negative electrode, and a separator between the positive and negative electrodes. The positive electrode, separator, and negative electrode are stacked and then wound to form a wound structure.

[0072] In some embodiments, the positive electrode includes a positive current collector and a positive active material layer disposed on the positive current collector, and the negative electrode includes a negative current collector and a negative active material layer disposed on the negative current collector.

[0073] In some embodiments, both the positive current collector and the negative current collector are metal layers. As an example, the positive current collector may be a metal layer comprising at least one of aluminum, nickel, tantalum, and titanium, such as aluminum foil. The negative current collector may be a metal layer comprising at least one of copper, nickel, tantalum, and titanium, such as copper foil.

[0074] In some embodiments, the positive electrode active material layer includes a positive electrode active material, which may include at least one of lithium cobalt oxide, lithium nickel cobalt manganese oxide, lithium nickel cobalt aluminum oxide, lithium iron phosphate, lithium manganese iron phosphate, or lithium manganese oxide. The negative electrode active material layer includes a negative electrode active material, which may include at least one of graphite, hard carbon, soft carbon, silicon, silicon-oxygen materials, and silicon-carbon materials.

[0075] In some embodiments, the separator includes insulating substrates such as polyethylene film, polypropylene film, polyester film, or polyimide film, to isolate the positive electrode and the negative electrode.

[0076] In some embodiments, the electrolyte contains a lithium salt and a solvent, the lithium salt can be one or more of LiPF, LiBF, LiClO, LiB(CH), LiCHSO, LiCFSO, LiN(SOCF), LiC(SOCF), LiBOB. The solvent can be a carbonate compound, a carboxylate compound, an ether compound, other organic solvents, or a combination thereof.

[0077] In some embodiments, the electrode assembly includes a first electrode part (not shown in the figure) and a second electrode part (not shown in the figure), the second electrode part and the first electrode part are arranged along the axial direction X. One of the first electrode part and the second electrode part is a positive electrode, and the other of the first electrode part and the second electrode part is a negative electrode.

[0078] In some embodiments, referring to FIG. 1 and FIG. 2, the cylindrical battery 100 includes a pole post 40, the pole post 40 is disposed in the top cover 20 and partially exposed from the top cover 20, the pole post 40 is insulatedly connected with the top cover 20, and the pole post 40 is connected with the electrode assembly.

[0079] In some embodiments, the first electrode part is connected with the shell 10, and the second electrode part is connected with the pole post 40.

[0080] In some other embodiments, the first electrode part is connected with the pole post 40, and the second electrode part is connected with the shell 10.

[0081] In some embodiments, the electrode assembly is in a winding structure, and one end of the electrode assembly can be a positive electrode along the axial direction X. A plurality of positive electrode tabs are cut out from the positive electrode tab at one end of the electrode assembly along the axial direction X, and the plurality of positive electrode tabs are flattened to form the first electrode part. A plurality of negative electrode tabs are cut out from the negative electrode tab at the other end of the electrode assembly, and the plurality of negative electrode tabs are flattened to form the second electrode part.

[0082] In some embodiments, one end of the electrode assembly can be a negative electrode along the axial direction X. A plurality of negative electrode tabs are cut out from the negative electrode tab at one end of the electrode assembly along the axial direction X, and the plurality of negative electrode tabs are flattened to form the first electrode part. A plurality of positive electrode tabs are cut out from the positive electrode tab at the other end of the electrode assembly, and the plurality of positive electrode tabs are flattened to form the second electrode part.

[0083] In some embodiments, referring to FIG. 1 and FIG. 2, the cylindrical battery 100 includes an insulating layer 50, the insulating layer 50 includes a first part 51, the first part 51 covers part of the first outer surface 112, and the first part 51 is located on one side of the welding wire 102 along the axial direction X, and the first part 51 is separated from or connected with the welding wire 102.

[0084] The first outer surface 112 of the side wall 11 is provided with an insulation layer 50, which is beneficial to insulate and protect the side wall 11. A first portion 51 of the insulation layer 50 is separated from or connected to the solder wire 102 along the axial direction X, so that the insulation layer 50 does not cover the area where the solder wire 102 is formed, thereby reserving more space for the solder wire 102 and facilitating the formation of the solder wire 102. The area where the insulation layer 50 does not cover the solder wire 102 is also beneficial to reduce the size of the cylindrical battery 100 and improve the energy density of the cylindrical battery 100. Compared with the solution of wrapping the shell 10 with a heat-shrinkable film, the heat-shrinkable film needs to be provided with a flange on the end surface of the cylindrical battery 100 to avoid sliding or loosening, and the heat-shrinkable film is easily damaged or slides after being lifted by the solder wire 102, which affects the safety and reliability of the cylindrical battery 100. In the above embodiment, the insulation layer 50 is provided, and the first portion 51 of the insulation layer 50 is separated from or connected to the solder wire 102 along the axial direction X, which is beneficial to reduce the possibility of the insulation layer 50 being lifted by the solder wire 102, improve the adhesion strength of the insulation layer 50 and the side wall 11, and improve the safety and reliability of the cylindrical battery 100.

[0085] In some embodiments, referring to FIGS. 2 and 7, the thickness of the solder wire 102 along the direction perpendicular to the axial direction X and intersecting the axis L0 of the cylindrical battery is H1, and the thickness of the insulation layer 50 along the direction perpendicular to the axial direction X and intersecting the axis L0 of the cylindrical battery is H2, H2>H1. When the thickness H2 of the insulation layer 50 along the direction perpendicular to the axial direction X is greater than the thickness H1 of the solder wire 102 along the direction perpendicular to the axial direction X, the insulation layer 50 is first contacted when the cylindrical battery 100 is contacted with other components or other cylindrical batteries 100, which is beneficial to protect the solder wire 102, reduce the possibility of damage to the solder wire 102, and improve the safety and reliability of the cylindrical battery 100.

[0086] It should be noted that the axis L0 is a virtual straight line parallel to the axial direction X of the cylindrical battery and passing through the geometric center of the cylindrical battery. The direction perpendicular to the axial direction X and intersecting the axis L0 of the cylindrical battery can be understood as a direction observed along the axial direction X from the center of the shell 10 to the periphery of the shell 10, or a direction from the periphery of the shell 10 to the center of the shell 10. For example, when the cylindrical battery 100 is a cylindrical battery, the direction perpendicular to the axial direction X can be understood as the radial direction Y of the cylindrical battery.

[0087] In some embodiments, 0.02mm≤H1≤0.12mm, which is beneficial to improve the welding strength between the top cover 20 and the side wall 11 on the one hand, and does not make the volume of the solder wire 102 too large on the other hand, thereby reducing the occupied space of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100.

[0088] As an exemplary example, H1 can be any one of 0.02mm, 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, or 0.12mm, or any value between any two of them.

[0089] In some embodiments, 0.03mm≤H2≤0.15mm, on the one hand, it is conducive to increasing the thickness of the insulation layer 50, reducing the risk of the insulation layer 50 being damaged to expose the first outer surface 112, and making the thickness of the insulation layer 50 in the direction perpendicular to the axial direction X greater than the thickness of the welding wire 102; on the other hand, it makes the insulation layer 50 not too thick, which is conducive to reducing the volume and weight of the cylindrical battery 100, and improving the safety and reliability of the cylindrical battery 100.

[0090] As an exemplary example, H2 can be any one of 0.03mm, 0.04mm, 0.05mm, 0.06mm, 0.07mm, 0.08mm, 0.09mm, 0.1mm, 0.11mm, 0.12mm, 0.13mm, 0.14mm, or 0.15mm, or any value between any two of them.

[0091] Test of H1 and H2: 20 acquisition points are evenly taken along the circumference of the side wall 11 of the cylindrical battery 100 by an image size tester (Keyence IM8000), an inscribed circle is fitted through the acquisition points, and the center of the circle is determined. The center of the circle is connected with the 20 acquisition points respectively to form 20 lines. The 20 lines are extended to intersect with the profile of the welding wire 102 and the insulation layer 50, respectively. The distance from the acquisition point to the intersection point of the line and the welding wire 102 is measured, and there are 20 values in total. The average value is taken to obtain the thickness H1 of the welding wire 102. The distance from the acquisition point to the intersection point of the line and the insulation layer 50 is measured, and there are 20 values in total. The average value is taken to obtain the thickness H2 of the insulation layer 50.

[0092] In some embodiments, referring to FIGS. 2 and 7, along the axial direction X, the height of the welding wire 102 is W, and 0.8mm≤W≤1.2mm, on the one hand, it is conducive to improving the welding strength between the top cover 20 and the side wall 11, and on the other hand, it does not make the volume of the welding wire 102 too large, which is conducive to reducing the occupied space of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100.

[0093] Test of W: 20 widths of the welding wire 102 in the axial direction X are evenly taken along the circumference of the welding wire 102 by an image size tester (Keyence IM8000), and the average value is taken to obtain the width W of the welding wire 102.

[0094] As an illustrative example, W can be any one of 0.8 mm, 0.81 mm, 0.82 mm, 0.83 mm, 0.84 mm, 0.85 mm, 0.86 mm, 0.87 mm, 0.88 mm, 0.89 mm, 0.9 mm, 0.91 mm, 0.92 mm, 0.93 mm, 0.94 mm, 0.95 mm, 0.96 mm, 0.97 mm, 0.98 mm, 0.99 mm, 1 mm, 1.01 mm, 1.02 mm, 1.03 mm, 1.04 mm, 1.05 mm, 1.06 mm, 1.07 mm, 1.08 mm, 1.09 mm, 1.1 mm, 1.11 mm, 1.12 mm, 1.13 mm, 1.14 mm, 1.15 mm, 1.16 mm, 1.17 mm, 1.18 mm, 1.19 mm, or 1.2 mm, or any value therebetween.

[0095] In some embodiments, referring to FIG. 2 and FIG. 7, along the axial direction X, the first portion 51 of the insulation layer 50 is spaced apart from the welding line 102, and the distance between the first portion 51 and the welding line 102 is L, 0.5 mm≤L≤5 mm. When the distance L between the first portion 51 and the welding line 102 is within this range, on the one hand, the distance between the first portion 51 and the area where the welding line 102 is formed is not too small, which is conducive to achieving the spacing between the first portion 51 and the welding line 102, facilitating the processing of the insulation layer 50 and the welding line 102, and reducing the possibility of the insulation layer 50 covering the welding line 102 due to processing errors and the like; on the other hand, the distance between the first portion 51 and the area where the welding line 102 is formed is not too large, which is conducive to improving the comprehensiveness of the insulation protection of the shell 10 by the insulation layer 50.

[0096] Test of L: Through an image size tester (Keyence IM8000), 20 distances between the insulation layer 50 and the welding line 102 in the axial direction X are evenly taken along the circumferential direction of the cylindrical battery 100, and the average value is obtained as L.

[0097] As an illustrative example, L can be any one of 0.5 mm, 0.6 mm, 0.7 mm, 0.8 mm, 0.9 mm, 1 mm, 1.1 mm, 1.2 mm, 1.3 mm, 1.4 mm, 1.5 mm, 1.6 mm, 1.7 mm, 1.8 mm, 1.8 mm, 1.9 mm, 2 mm, 2.1 mm, 2.2 mm, 2.3 mm, 2.4 mm, 2.5 mm, 2.6 mm, 2.7 mm, 2.8 mm, 2.9 mm, 3 mm, 3.1 mm, 3.2 mm, 3.3 mm, 3.4 mm, 3.5 mm, 3.5 mm, 3.6 mm, 3.7 mm, 3.8 mm, 3.9 mm, 4 mm, 4.1 mm, 4.2 mm, 4.3 mm, 4.4 mm, 4.5 mm, 4.6 mm, 4.7 mm, 4.8 mm, 4.9 mm, or 5 mm, or any value therebetween.

[0098] In some embodiments, referring to FIG. 2, the shell 10 comprises a connecting wall 13 having a first connecting surface 131 connecting the first outer surface 112 of the side wall 11 and the second outer surface 122 of the bottom wall 12.

[0099] In some embodiments, referring to FIG. 2, the connecting wall 13 has a second connecting surface 132 connecting the first inner surface 111 of the side wall 11 and the second inner surface 121 of the bottom wall 12.

[0100] In some embodiments, the first portion 51 covers part of the first connecting surface 131, which is conducive to reducing the possibility of the first portion 51 contacting other components.

[0101] In other embodiments, the first portion 51 covers the entire first connecting surface 131, which is conducive to improving the comprehensiveness of the insulation layer 50 in insulating and protecting the shell 10.

[0102] The connecting wall 13 is a corner of the shell 10, which is prone to damage under the working conditions of vibration and falling. In the above embodiments, the first portion 51 covers at least part of the first connecting surface 131, which is conducive to improving the comprehensiveness of the insulation layer 50 in insulating and protecting the shell 10, improving the anti-vibration and anti-falling performance of the corner of the shell 10, and improving the safety and reliability of the cylindrical battery 100.

[0103] In some embodiments, the first portion 51 covers part of the first outer surface 112 and part of the first connecting surface 131, which is conducive to improving the comprehensiveness of the insulation layer 50 in insulating and protecting the shell 10, and improving the safety and reliability of the cylindrical battery 100.

[0104] In some embodiments, referring to FIG. 2, the first portion 51 covers part of the first outer surface 112 and the entire first connecting surface 131, which is conducive to further improving the comprehensiveness of the insulation protection of the shell 10 by the insulation layer 50 and further improving the safety and reliability of the cylindrical battery 100.

[0105] In some embodiments, the first portion 51 is provided as a continuous whole, and the first portion 51 covering the first outer surface 112 and the first connecting surface 131 is provided continuously.

[0106] In some embodiments, referring to FIG. 2, the first portion 51 does not exceed the second outer surface 122 along the axial direction X, which is conducive to reducing the space occupied by the insulation layer 50 along the axial direction X, so that the insulation layer 50 does not increase the height of the cylindrical battery 100 along the axial direction X, and is conducive to improving the energy density of the cylindrical battery 100.

[0107] In some embodiments, the cylindrical battery 100 comprises a sealing cover, the bottom wall 12 is provided with a liquid injection hole, the liquid injection hole is in communication with the accommodation cavity 101, and the sealing cover is welded with the bottom wall 12 and seals the liquid injection hole.

[0108] In some other embodiments, referring to FIG. 8, the insulation layer 50 comprises a second portion 52, the second portion 52 covers the outer periphery of the second outer surface 122, so that the insulation layer 50 covers part of the first outer surface 112, the first connecting surface 131 and part of the second outer surface 122. The second portion 52 covers the outer periphery of the second outer surface 122, which is conducive to insulating and protecting the outer peripheral area of the second outer surface 122, further improving the comprehensiveness of the insulation protection of the shell 10, and improving the safety and reliability of the cylindrical battery 100.

[0109] In some embodiments provided with the second portion 52, referring to FIG. 8, the cylindrical battery 100 is a cylindrical battery, along the radial direction Y of the cylindrical battery, the width of the second portion 52 is R1, and 0 < R1 ≤ 3 mm. When 0 < R1 ≤ 3 mm, on the one hand, it is conducive to further improving the comprehensiveness of the insulation protection of the shell 10, and when the cylindrical battery 100 is placed vertically, the second portion 52 contacts the external member before the bottom wall 12, which is conducive to protecting the bottom wall 12; on the other hand, the width R1 of the second portion 52 is not too large, which is conducive to reserving a welding area and connecting the bottom wall 12 and the bus bar when multiple battery cells are connected in series and in parallel.

[0110] In some embodiments, the first portion 51 and the second portion 52 are provided continuously, the first portion 51 covers the first connecting surface 131 and part of the first outer surface 112, and the second portion 52 is connected with the first portion 51 and covers the outer periphery of the second outer surface 122.

[0111] In some embodiments, referring to FIG. 9, the insulation layer 50 comprises a third portion 53, the top cover 20 comprises a third outer surface 201, and the third portion 53 covers the outer periphery of the third outer surface 201, so that the insulation layer 50 covers part of the first outer surface 112, the first connecting surface 131, and part of the top cover 20. The third outer surface 201 is the surface of the top cover 20 located outside the accommodating cavity 101. In some embodiments, part of the area of the third outer surface 201 is a plane perpendicular to the axial direction X. The third portion 53 covers the outer periphery of the third outer surface 201, which is beneficial to insulate and protect the outer peripheral area of the top cover 20, further improve the comprehensiveness of the insulation protection of the shell 10, and improve the safety and reliability of the cylindrical battery 100.

[0112] In some embodiments, referring to FIG. 9, the cylindrical battery 100 is a cylindrical battery, and along the radial direction Y of the cylindrical battery, the width of the third portion 53 is R2, and 0 < R2 ≤ 3 mm. When 0 < R2 ≤ 3 mm, on the one hand, it is beneficial to further improve the comprehensiveness of the insulation protection of the shell 10 and protect the top cover 20; on the other hand, the width R2 of the third portion 53 is not too large, which is beneficial to reserve a welding area and facilitate the connection between the top cover 20 and the bus bar when the plurality of battery cells are connected in series and in parallel.

[0113] In some embodiments, the third portion 53 and the first portion 51 are spaced apart, which is beneficial to prevent the insulation layer 50 from covering the welding wire 102.

[0114] In some embodiments, referring to FIG. 2, the first outer surface 112 comprises a rough surface 113, and the insulation layer 50 covers at least part of the rough surface 113. The rough surface 113 makes the insulation layer 50 more firmly fixed to the shell 10, which is beneficial to reduce the risk of peeling of the insulation layer 50 and improve the stability and reliability of the cylindrical battery 100.

[0115] In some embodiments, the roughness of the rough surface 113 is 1.5-2.5 μm. This is beneficial to improve the bonding strength between the insulation layer 50 and the shell 10 and reduce the risk of peeling.

[0116] In some embodiments, the insulation layer 50 comprises a light-cured material, which is beneficial to use light-cured means to improve the stability of the connection between the insulation layer 50 and the shell 10 or the stability of the connection between the insulation layer 50 and the top cover 20.

[0117] In some embodiments, the light-cured material comprises one of polyurethane, polyacrylic acid, and polysiloxane.

[0118] In some embodiments, the first portion 51 of the insulation layer 50 is coated on the first outer surface 112. The first portion 51 of the insulation layer 50 is disposed on the first outer surface 112 by coating with a fluid comprising a light-curing material. The coating can be spraying or painting, which is not specifically limited herein.

[0119] In some embodiments, the first portion 51 of the insulation layer 50 is coated on the first connecting surface 131.

[0120] In some embodiments, the second portion 52 of the insulation layer 50 is coated on the second outer surface 122.

[0121] In some embodiments, the third portion 53 of the insulation layer 50 is coated on the partial top cover 20.

[0122] Some embodiments of the present application further provide a manufacturing method of the cylindrical battery 100, comprising the following steps:

[0123] The top cover 20 is welded to the side wall 11 to form a welding line 102, and a portion of the welding line 102 is located on the first outer surface 112 of the side wall 11.

[0124] The first outer surface 112 of the side wall 11 is processed into a rough surface 113.

[0125] A light-curing material is coated on the rough surface 113, and the light-curing material on the rough surface 113 is located on one side of the welding line 102 along the axial direction X.

[0126] The light-curing material is subjected to a curing process to form the insulation layer 50.

[0127] In the present embodiment, the insulation layer 50 on the rough surface 113 is located on one side of the welding line 102 along the axial direction X, so that the insulation layer 50 does not cover the area where the welding line 102 is formed, which is beneficial to reserving more welding space and facilitating the formation of the welding line 102. The insulation layer 50 not covering the area where the welding line 102 is formed is also beneficial to reducing the size of the cylindrical battery 100 and improving the energy density of the cylindrical battery 100. Compared with the scheme of wrapping the insulation film on the shell 10, the insulation layer 50 on the rough surface 113 in the above-mentioned embodiments is located on one side of the welding line 102 along the axial direction X, which is beneficial to reducing the possibility of the insulation layer 50 being lifted by the welding line 102, improving the adhesion strength of the insulation layer 50 and the shell 10, and improving the safety and reliability of the cylindrical battery 100.

[0128] It should be noted that the order of the expressions used in the above description of the processing procedure does not represent the actual processing order. When there is no necessary time relationship between two steps, the order of the two steps can be adjusted. For example, the step of welding the top cover 20 to the side wall 11 and forming the welding line 102 can be before the series of steps of forming the insulating layer 50, or after the series of steps of forming the insulating layer 50. Here, the series of steps of forming the insulating layer 50 specifically refer to: treating the first outer surface 112 of the side wall 11 into a rough surface 113, coating a light-curing material on the rough surface 113, and positioning the light-curing material on the rough surface 113 on one side of the welding line 102 along the axial direction X, and performing a curing treatment on the light-curing material to form the insulating layer 50.

[0129] In some embodiments, the welding of the top cover 20 to the side wall 11 is laser welding.

[0130] In some embodiments, the rough surface 113 of the side wall 11 can be obtained by laser treatment, grinding, sandblasting, etc., which are not specifically limited here.

[0131] In some embodiments, the curing treatment of the insulating layer 50 can be ultraviolet light treatment or heat treatment, etc., which are not listed one by one here.

[0132] In some embodiments, the manufacturing method of the cylindrical battery 100 further includes the step of: attaching an isolation layer on the first outer surface 112 along the axial direction X at a position between the welding line 102 and the bottom wall 12. The insulating layer 50 is arranged on the rough surface 113. The isolation layer is removed, and a gap is formed between the insulating layer 50 and the welding line 102.

[0133] The isolation region separates the first portion 51 from the welding line 102, which is beneficial to reduce the possibility of the insulating layer 50 covering the welding line 102 due to processing errors, etc.

[0134] In some embodiments, the width of the isolation region along the axial direction X is equal to the distance L between the first portion 51 and the welding line 102.

[0135] In some embodiments, the isolation layer is a single-sided adhesive tape.

[0136] Referring to FIG. 10, the embodiments in the present application also provide a power-using device 1000, which includes the cylindrical battery 100 in any of the above embodiments.

[0137] In some embodiments, referring to FIG. 10, the power-using device 1000 further includes a device body 200, and the cylindrical battery 100 is installed on the device body 200 and used to supply power to the device body 200.

[0138] In some embodiments, the electric device 1000 can be a drone, an electric scooter, a cleaning robot, an energy storage device, an electric tool, and the like, which are not listed one by one here.

[0139] Since the electric device 1000 adopts the technical solutions of the cylindrical battery 100 in any of the above embodiments, at least the beneficial effects brought by the technical solutions of any of the above embodiments of the cylindrical battery 100 are achieved, which are not listed one by one here.

[0140] In addition, those skilled in the art of the present technology should recognize that the above embodiments are only used to illustrate the present application, and are not used as a limitation on the present application. Any appropriate changes and variations made to the above embodiments within the spirit and scope of the present application fall within the scope of the present disclosure.

Claims

1. A cylindrical battery characterized by comprising: The application relates to a cylindrical battery, comprising: a shell, comprising a side wall, the side wall comprising a first outer surface; a top cover welded with the side wall and forming a welding line, part of the welding line being located on the first outer surface; an insulation layer comprising a first part, the first part covering part of the first outer surface, the first part being located on one side of the welding line along an axial direction of the cylindrical battery and being separated from or connected to the welding line.

2. The cylindrical battery according to claim 1, characterized by Along a direction perpendicular to the axial direction and intersecting an axis of the cylindrical battery, a thickness of the welding line is H1, and a thickness of the insulation layer is H2, H2>H1.

3. The cylindrical battery of claim 2, wherein 0.02mm<=H1<=0.12mm; and / or, 0.03mm<=H2<=0.15mm.

4. The cylindrical battery according to any one of claims 1 to 3, characterized by, Along the axial direction, a height of the welding line is W, 0.8mm<=W<=1.2mm.

5. The cylindrical battery according to any one of claims 1 to 4, characterized by, Along the axial direction, the first part is separated from the welding line, and a distance between the first part and the welding line is L, 0.5mm<=L<=5mm.

6. The cylindrical battery of claim 1, wherein, The shell further comprises a bottom wall and a connecting wall connecting the side wall and the bottom wall; The bottom wall comprises a second outer surface; The connecting wall has a first connecting surface connecting the first outer surface and the second outer surface, and the first part covers at least part of the first connecting surface.

7. The cylindrical battery of claim 6, wherein, Along the axial direction, the first part does not exceed the second outer surface.

8. The cylindrical battery of claim 6, wherein, The insulation layer comprises a second part covering an outer periphery of the second outer surface; The cylindrical battery is a cylindrical battery, and along a radial direction of the cylindrical battery, a width of the second part is R1, 0 9. The cylindrical battery according to any one of claims 6 to 8, characterized by, The insulation layer comprises a third part, and the top cover comprises a third outer surface, and the third part covers an outer periphery of the third outer surface; The cylindrical battery is a cylindrical battery, and along a radial direction of the cylindrical battery, a width of the third part is R2, 0 10. The cylindrical battery according to any one of claims 1 to 9, wherein The first outer surface comprises a rough surface, and the first part covers at least part of the rough surface.

11. The cylindrical battery according to any one of claims 1 to 10, wherein The insulation layer comprises a photocuring material.

12. The cylindrical battery of claim 11, wherein, The photocuring material comprises one of polyurethane, polyacrylic acid and polysiloxane.

13. A method of manufacturing a cylindrical battery as claimed in claim 11 or 12, characterized in that The application further relates to a method for manufacturing the cylindrical battery, comprising the following steps: welding the top cover to the side wall and forming the welding line, part of the welding line being located on the first outer surface of the side wall; processing the first outer surface of the side wall into a rough surface; coating the photocuring material on the rough surface and locating the photocuring material on one side of the welding line along the axial direction; carrying out a curing treatment on the photocuring material to form the insulation layer.

14. The method of manufacturing a cylindrical battery according to claim 13, wherein The application further relates to a cylindrical battery manufacturing method, comprising the following steps: along the axial direction, pasting an isolation layer on the first outer surface on one side of the welding line; arranging the insulation layer on the rough surface; removing the isolation layer to form a gap between the insulation layer and the welding line.

15. An electrical device, characterized by The application relates to a cylindrical battery, comprising any one of claims 1 to 12.

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