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

Abstract

The invention discloses a cylindrical battery (100), a manufacturing method of the cylindrical battery (100) and electric equipment (1000). The cylindrical battery (100) comprises a shell (10), a top cover (20) and an insulating layer (50). The housing (10) comprises a side wall (11), and the side wall (11) comprises a first outer surface (112). The top cover (20) and the side wall (11) are welded to form a bonding wire (102), and the bonding wire (102) is partially located on the first outer surface (112). The insulating layer (50) comprises a first part (51), the first part (51) covers part of the first outer surface (112), the first part (51) is located on one side of the bonding wire (102) in the axial direction of the cylindrical battery (100), and the first part (51) is separated from or connected with the bonding wire (102). The first outer surface (112) of the housing (10) is provided with an insulating layer (50), and the insulating layer (50) does not cover the bonding wire (102), thereby facilitating the reduction of the size of the cylindrical battery (100), and improving the energy density of the cylindrical battery (100).

Description

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. SUMMARY

[0003] 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.

[0004] In a first aspect, the present application provides a cylindrical battery, which 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 with the side wall to form a welding line, and the welding line is partially located on the first outer surface. The insulation layer comprises a first part, the first part covers part of the first outer surface, and the first part is located on one side of the welding line along an axial direction of the cylindrical battery, and the first part is separated from or connected to the welding line.

[0005] 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.

[0006] In one or more of the above embodiments, the thickness of the welding line is H1 along a direction perpendicular to the axial direction and intersecting the axial line of the cylindrical battery, and the thickness of the insulation layer is H2, and H2>H1.

[0007] 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 damage to the welding line, and is beneficial to improving the safety and reliability of the cylindrical battery.

[0008] In one or more of the above embodiments, 0.02mm≤H1≤0.12mm.

[0009] 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.

[0010] In one or more of the above embodiments, 0.03mm≤H2≤0.15mm.

[0011] 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.

[0012] 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.

[0013] 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.

[0014] 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.

[0015] 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 of the insulation layer covering 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.

[0016] In one or more of the above embodiments, the shell further includes a bottom wall and a connecting wall, the connecting wall connects the side wall and the bottom wall, the bottom wall includes 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.

[0017] 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.

[0018] In one or more of the above embodiments, the first portion does not protrude beyond the second outer surface in the axial direction.

[0019] In one or more of the above embodiments, the first portion does not protrude beyond 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.

[0020] In one or more of the above embodiments, the insulation layer comprises 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.

[0021] 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 vertically placed, 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 parallel.

[0022] In one or more of the above embodiments, the insulation layer comprises a third portion, and the top cover comprises 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.

[0023] 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 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 parallel.

[0024] In one or more of the above embodiments, the first outer surface comprises a rough surface, and the first portion covers at least part of the rough surface.

[0025] 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.

[0026] In one or more of the above embodiments, the insulation layer comprises 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.

[0027] In one or more of the above embodiments, the light-cured material comprises one of polyurethane, polyacrylic acid, and polysiloxane.

[0028] In one or more of the above embodiments, the first portion is coated on the first outer surface.

[0029] In the 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.

[0030] In the above embodiment, 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 embodiment, 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 and the side wall, and improving the safety and reliability of the cylindrical battery.

[0031] 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.

[0032] In the above embodiment, the isolation area separates the first part 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.

[0033] In the third aspect, the application provides an electric device comprising the cylindrical battery according to any one of the above embodiments.

[0034] In the above embodiment, the safety and reliability of the cylindrical battery are improved, which is beneficial to improving the safety and reliability of the electric device.

[0035] 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 part, and the first part covers part of the first outer surface. Along the axial direction of the cylindrical battery, the first part is located on one side of the welding line, and the first part 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 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. BRIEF DESCRIPTION OF DRAWINGS

[0036] Figure 1 This is a schematic diagram of the structure of a cylindrical battery provided in an embodiment of this application.

[0037] Figure 2 A partial cross-sectional view of a cylindrical battery provided in an embodiment of this application.

[0038] Figure 3 for Figure 2 A top view of a cylindrical battery.

[0039] Figure 4 for Figure 2 A bottom view of a cylindrical battery.

[0040] Figure 5 A partial cross-sectional view of a cylindrical battery structure provided in another embodiment of this application.

[0041] Figure 6 for Figure 5 A top view of part of the structure of a cylindrical battery.

[0042] Figure 7 for Figure 2 A magnified view of part A in the middle.

[0043] Figure 8 This is a partial cross-sectional view of a portion of the structure of a cylindrical battery provided in another embodiment of this application.

[0044] Figure 9 A cross-sectional view of the top cover and the third part provided in one embodiment of this application.

[0045] Figure 10 This is a schematic diagram of an electrical device provided in an embodiment of this application.

[0046] Explanation of main component symbols

[0047] 100 cylindrical batteries

[0048] Casing 10

[0049] Side wall 11

[0050] First inner surface 111

[0051] First outer surface 112

[0052] Rough surface 113

[0053] Bottom wall 12

[0054] Second inner surface 121

[0055] Second outer surface 122

[0056] Connecting wall 13

[0057] First connecting surface 131

[0058] Second connecting surface 132

[0059] Top cover 20

[0060] Third outer surface 201

[0061] Accommodating cavity 101

[0062] Welding wire 102

[0063] Pole 40

[0064] Insulating layer 50

[0065] First portion 51

[0066] Second portion 52

[0067] Third portion 53

[0068] Axial direction X

[0069] Radial direction Y

[0070] Axis L0

[0071] Device body 200

[0072] Electric device 1000 DETAILED DESCRIPTION

[0073] 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 some of the embodiments of the present application, but not all of the embodiments of the present application.

[0074] It should be noted that unless otherwise explicitly specified and limited, the terms "mounting", "connecting", "connecting", "fixing" and the like should be understood in a broad sense, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be insulatively connected, or it can be electrically connected. When a component is considered to be "connected" to another component, it can be directly connected to another component or a middle component can exist at the same time. When a component is considered to be "provided on" another component, it can be directly provided on another component or a middle component can exist at the same time.

[0075] The terms "top", "bottom" and similar expressions used herein are only for illustrative purposes.

[0076] Unless otherwise specified, the term "multiple" used herein refers to two or more.

[0077] The terms “first”, “second”, etc., are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implying the quantity, specific order, or primary and secondary relationship of the indicated technical features.

[0078] The term "perpendicular" is used to describe an ideal state between two components. In actual production or use, two components can exist in a state that is approximately perpendicular. For example, in numerical terms, perpendicularity can refer to the angle between two straight lines within the range of 90° ± 10°, the dihedral angle between two planes within the range of 90° ± 10°, or the angle between a straight line and a plane within the range of 90° ± 10°.

[0079] It should be noted that when a parameter is greater than, equal to or less than a certain endpoint value, it should be understood that the endpoint value is allowed to have a tolerance of ±5%.

[0080] It should be understood that the dimensions of the structures shown in the accompanying drawings are provided for better understanding and easier description, and this application is not limited to the dimensions shown in the drawings. To make the invention clear, elements unrelated to the description have been omitted from the details of this specification.

[0081] 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 terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application.

[0082] In related technologies, heat shrink film is usually used to insulate and protect the casing of cylindrical batteries. However, heat shrink film is prone to shifting or loosening during transportation / use, which affects the safety and reliability of cylindrical batteries.

[0083] This application provides a cylindrical battery, which includes a casing and an insulating layer. The casing includes interconnected sidewalls and a bottom wall. The sidewalls include a first inner surface and a first outer surface. Viewed axially along the cylindrical battery, the first inner surface is located inside the first outer surface. A top cover and a bottom wall are arranged axially. The top cover is welded to the sidewalls to form a weld line, and the top cover and casing enclose a receiving cavity. The insulating layer includes a first portion disposed on the first outer surface. Along the axial direction, the first portion is located on one side of the weld line, and the first portion is either separate from or connected to the weld line.

[0084] The insulating layer is beneficial to insulating and protecting the shell. The first portion of the insulating layer is axially separated from or connected to the welding wire, so that the insulating layer does not cover the area where the welding wire is formed, thereby reserving more welding space and facilitating the formation of the welding wire. The area where the insulating layer does not cover the welding wire 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 insulating layer is provided, and the first portion of the insulating layer is axially separated from or connected to the welding wire, thereby reducing the possibility of the insulating layer being lifted by the welding wire, improving the adhesion strength of the insulating layer and the side wall, and improving the safety and reliability of the cylindrical battery.

[0085] Some embodiments of the present application will be described below with reference to the accompanying drawings. The following embodiments and features in the embodiments can be combined with each other without conflict.

[0086] Please refer to Figure 1 and Figure 2 , the present 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.

[0087] In some embodiments, please refer to Figures 2 to 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 along the axial direction X of the cylindrical battery 100 (for the sake of convenience, the axial direction X of the cylindrical battery 100 is referred to as the axial direction X hereinafter). The top cover 20 is welded to the side wall 11 and forms a welding wire 102.

[0088] In some embodiments, please refer to Figure 2 , Figure 5 and Figure 6 , the side wall 11 comprises a first inner surface 111 and a first outer surface 112. The first inner surface 111 is located inside the first outer surface 112 when viewed along the axial direction X. The welding wire 102 is partially located on the first outer surface 112.

[0089] In some embodiments, please refer to Figure 2 , Figures 5 to 7 , the bottom wall 12 comprises a second inner surface 121 and a second outer surface 122 arranged opposite to each other. 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.

[0090] In some embodiments, the shell 10 is cylindrical.

[0091] In some embodiments, please refer to 1 and Figure 2 , the cylindrical battery 100 is a cylindrical battery, and the shell 10 is a cylindrical shell.

[0092] 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.

[0093] 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).

[0094] 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).

[0095] 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.

[0096] 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.

[0097] 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.

[0098] 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.

[0099] 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.

[0100] 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.

[0101] 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.

[0102] 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.

[0103] In some embodiments, referring to Figure 1 and Figure 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.

[0104] 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.

[0105] In other embodiments, the first electrode part is connected with the pole post 40, and the second electrode part is connected with the shell 10.

[0106] In some embodiments, the electrode assembly is in a winding structure, and one end of the electrode assembly along the axial direction X can be a positive electrode. 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.

[0107] In some embodiments, one end of the electrode assembly along the axial direction X can be a negative electrode. 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.

[0108] In some embodiments, referring to Figure 1 and Figure 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, 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.

[0109] 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.

[0110] In some embodiments, referring to Figure 2 and Figure 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.

[0111] 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 the direction observed along the axial direction X from the center of the shell 10 to the periphery of the shell 10, or 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.

[0112] 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.

[0113] 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.

[0114] 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.

[0115] 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.

[0116] 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.

[0117] In some embodiments, please refer to Figure 2 and Figure 7 In 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.

[0118] 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.

[0119] 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.

[0120] In some embodiments, referring to Figure 2 and Figure 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 region 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 region 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.

[0121] 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.

[0122] 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.

[0123] In some embodiments, referring to Figure 2 , the housing 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.

[0124] In some embodiments, referring to Figure 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.

[0125] 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.

[0126] 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 housing 10.

[0127] The connecting wall 13 is a corner of the housing 10, which is prone to damage under the working conditions of vibration and falling. The first portion 51 covering at least part of the first connecting surface 131 in the above embodiments is conducive to improving the comprehensiveness of the insulation layer 50 in insulating and protecting the housing 10, improving the anti-vibration and anti-falling performance of the corner of the housing 10, and improving the safety and reliability of the cylindrical battery 100.

[0128] 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 housing 10, and improving the safety and reliability of the cylindrical battery 100.

[0129] In other embodiments, referring to Figure 2The 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.

[0130] 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.

[0131] In some embodiments, referring to Figure 2 The first portion 51 does not exceed the second outer surface 122 in the axial direction X, which is conducive to reducing the space occupied by the insulation layer 50 in the axial direction X and preventing the insulation layer 50 from increasing the height of the cylindrical battery 100 in the axial direction X, thereby improving the energy density of the cylindrical battery 100.

[0132] In some embodiments, the cylindrical battery 100 includes 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 to the bottom wall 12 and seals the liquid injection hole.

[0133] In some other embodiments, referring to Figure 8 The insulation layer 50 includes 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.

[0134] In some embodiments provided with the second portion 52, referring to Figure 8 The cylindrical battery 100 is a cylindrical battery, and in 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 the second portion 52 is in contact with the external member before the bottom wall 12 when the cylindrical battery 100 is placed vertically, 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 facilitating the connection between the bottom wall 12 and the bus bar when multiple battery cells are connected in series and in parallel.

[0135] 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.

[0136] In some embodiments, referring toFigure 9 The insulating layer 50 includes a third portion 53, and the top cover 20 includes a third outer surface 201, the third portion 53 covering an outer periphery of the third outer surface 201, so that the insulating layer 50 covers the partial first outer surface 112, the first connecting surface 131, and part of the top cover 20. The third outer surface 201 is a surface of the top cover 20 located outside the accommodating cavity 101. In some embodiments, part 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 conducive to insulating protection of the outer peripheral region of the top cover 20, further improves the comprehensiveness of the insulating protection of the shell 10, and improves the safety and reliability of the cylindrical battery 100.

[0137] In some embodiments, referring to Figure 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 conducive to further improving the comprehensiveness of the insulating protection of the shell 10 and protecting the top cover 20; on the other hand, the width R2 of the third portion 53 is not too large, which is conducive to reserving a welding area and facilitating the connection between the top cover 20 and the bus bar when the plurality of battery cells are connected in series and in parallel.

[0138] In some embodiments, the third portion 53 and the first portion 51 are spaced apart, which is conducive to preventing the insulating layer 50 from covering the welding wire 102.

[0139] In some embodiments, referring to Figure 2 The first outer surface 112 includes a rough surface 113, and the insulating layer 50 covers at least part of the rough surface 113. The rough surface 113 makes the insulating layer 50 more firmly fixed to the shell 10, which is conducive to reducing the risk of peeling of the insulating layer 50 and improving the stability and reliability of the cylindrical battery 100.

[0140] In some embodiments, the roughness of the rough surface 113 is 1.5-2.5 μm. This is conducive to improving the bonding strength between the insulating layer 50 and the shell 10 and reducing the risk of peeling.

[0141] In some embodiments, the insulating layer 50 includes a light-cured material, which is conducive to using light-cured means to improve the stability of the connection between the insulating layer 50 and the shell 10 or to improve the stability of the connection between the insulating layer 50 and the top cover 20.

[0142] In some embodiments, the light-cured material includes one of polyurethane, polyacrylic acid, and polysiloxane.

[0143] 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.

[0144] In some embodiments, the first portion 51 of the insulation layer 50 is coated on the first connecting surface 131.

[0145] In some embodiments, the second portion 52 of the insulation layer 50 is coated on the second outer surface 122.

[0146] In some embodiments, the third portion 53 of the insulation layer 50 is coated on the partial top cover 20.

[0147] Some embodiments of the present application further provide a manufacturing method of the cylindrical battery 100, comprising the following steps:

[0148] The top cover 20 is welded to the sidewall 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 sidewall 11.

[0149] The first outer surface 112 of the sidewall 11 is processed into a rough surface 113.

[0150] 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.

[0151] The light-curing material is subjected to a curing process to form the insulation layer 50.

[0152] 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.

[0153] 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 making the light-curing material on the rough surface 113 located 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.

[0154] In some embodiments, the welding of the top cover 20 to the side wall 11 is laser welding.

[0155] 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.

[0156] 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.

[0157] 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.

[0158] 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.

[0159] 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.

[0160] In some embodiments, the isolation layer is a single-sided adhesive tape.

[0161] Please refer to Figure 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.

[0162] In some embodiments, please refer to Figure 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.

[0163] 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.

[0164] 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 possessed, which are not listed one by one here.

[0165] In addition, those skilled in the art of the present technology should realize 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 essential scope of the present application fall within the scope of the present disclosure.

Claims

1. A cylindrical battery, characterized in that, include: A housing, including a sidewall, the sidewall including a first outer surface; A top cover is welded to the side wall to form a weld line, a portion of which is located on the first outer surface; An insulating layer includes a first portion that covers a portion of the first outer surface along the axial direction of the cylindrical battery. The first portion is located on one side of the bonding wire and is either separate from or connected to the bonding wire.

2. The cylindrical battery according to claim 1, characterized in that, Along a direction perpendicular to the axial direction and intersecting the axis of the cylindrical battery, the thickness of the bonding wire is H1, and the thickness of the insulating layer is H2, where H2 > H1.

3. The cylindrical battery according to claim 2, characterized in that, 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 in that, Along the axial direction, the height of the weld wire is W, 0.8mm≤W≤1.2mm.

5. The cylindrical battery according to any one of claims 1 to 4, characterized in that, Along the axial direction, the first portion is separated from the weld line, and the distance between the first portion and the weld line is L, 0.5mm≤L≤5mm.

6. The cylindrical battery according to claim 1, characterized in that, The housing further includes a bottom wall and a connecting wall, the connecting wall connecting the side wall and the bottom wall; The bottom wall includes a second outer surface; The connecting wall has a first connecting surface that connects the first outer surface and the second outer surface, and the first portion covers at least a portion of the first connecting surface.

7. The cylindrical battery according to claim 6, characterized in that, Along the axial direction, the first portion does not extend beyond the second outer surface.

8. The cylindrical battery according to claim 6, characterized in that, The insulating layer includes a second portion that covers the outer periphery of the second outer surface; The cylindrical battery is a cylindrical battery, and the width of the second part along the radial direction of the cylindrical battery is R1, where 0 < R1 ≤ 3 mm.

9. The cylindrical battery according to any one of claims 6 to 8, characterized in that, The insulating layer includes a third portion, and the top cover includes a third outer surface, the third portion covering the outer periphery of the third outer surface; The cylindrical battery is a cylindrical battery, and the width of the third part along the radial direction of the cylindrical battery is R2, where 0 < R2 ≤ 3 mm.

10. The cylindrical battery according to any one of claims 1 to 9, characterized in that, The first outer surface includes a rough surface, and the first portion covers at least a portion of the rough surface.

11. The cylindrical battery according to any one of claims 1 to 10, characterized in that, The insulating layer includes a photocurable material.

12. The cylindrical battery according to claim 11, characterized in that, The photocurable material includes one of polyurethane, polyacrylic acid, and polysiloxane.

13. A method for manufacturing a cylindrical battery as described in claim 11 or 12, characterized in that, Includes the following steps: The top cover is welded to the side wall to form the weld line, and a portion of the weld line is located on the first outer surface of the side wall; The first outer surface of the sidewall is roughened. The photocurable material is coated onto the rough surface, and the photocurable material is positioned on one side of the weld line along the axial direction; The photocurable material is cured to form the insulating layer.

14. The method for manufacturing a cylindrical battery according to claim 13, characterized in that, Also includes: An isolation layer is applied along the axial direction on the first outer surface at a position located on one side of the bonding wire; The insulating layer is disposed on the rough surface; Remove the isolation layer to create a gap between the insulating layer and the bonding wire.

15. An electrical appliance, characterized in that, Including the cylindrical battery as described in any one of claims 1 to 12.

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