Cylindrical battery and electronic device

Abstract

The utility model provides a cylindrical battery and an electronic device, the cylindrical battery comprising: a shell, an electrode assembly and an end cap; the shell comprises a side wall, one end of the side wall along the axial direction of the cylindrical battery comprises an opening, and the end face of the side wall on the opening side is a first end face; the electrode assembly is arranged in the shell; the end cap covers the opening and is electrically connected to the electrode assembly; the outer edge of the end cap is welded to the first end face to form a weld mark; wherein the side of the end cap away from the electrode assembly comprises a welding surface for electrical connection to the outside of the cylindrical battery, and along the thickness direction of the end cap, the weld mark is located between the welding surface and the electrode assembly. The cylindrical battery provided by the utility model can improve the problem that when the electrical connectors such as busbars are welded to the end caps, they are easily interfered with the weld marks at the welding positions of the end caps and the shells, thereby affecting the welding quality between the busbars and the end caps.

Description

Technical Field

[0001] The utility model relates to the technical field of batteries, in particular to a cylindrical battery and an electronic device. Background Art

[0002] When the cylindrical battery adopts the method of welding the end cover and the shell to achieve the sealing of the open end, the electrical connection between the end cover and the shell can be achieved, so that when the cylindrical batteries are assembled in groups, the end cover can be used as one of the positive and negative electrodes.

[0003] Therefore, in the prior art, busbars are usually welded on the surface of the end caps to achieve conductive connection between adjacent cylindrical batteries. During the welding process between the busbars and the end caps, the weld marks at the welding position between the end caps and the shell often interfere with the busbars, which in turn causes the busbars to fail to be flush with the surface of the end caps, resulting in a decrease in the welding quality between the busbars and the end caps, thereby affecting the stability of the current conduction of the cylindrical battery. Utility Model Content

[0004] The utility model provides a cylindrical battery and an electronic device to improve the technical problem that the welding of a busbar and an end cover easily interferes with the welding mark at the welding position of the end cover and a shell, thus affecting the welding quality between the busbar and the end cover.

[0005] To achieve the above-mentioned purpose and other related purposes, the utility model provides a cylindrical battery, which includes: a shell, an electrode assembly and an end cover; the shell includes a side wall, and one end of the side wall along the axial direction of the cylindrical battery includes an opening, and the end face of the side wall on the opening side is a first end face; the electrode assembly is arranged in the shell; the end cover covers the opening and is electrically connected to the electrode assembly; the outer edge of the end cover is welded to the first end face to form a weld mark; wherein, the side of the end cover facing away from the electrode assembly includes a welding surface for electrically connecting to the outside of the cylindrical battery; along the thickness direction of the end cover, the weld mark is located between the welding surface and the electrode assembly.

[0006] In an example of a cylindrical battery of the utility model, the end cover includes a first protrusion and a ring body portion, the ring body portion is arranged around the outer circumference of the first protrusion and is welded to the first end face, the weld mark is at least partially located on the ring body portion, the first protrusion protrudes relative to the ring body portion toward the side away from the electrode assembly, and the welding surface is located on the surface of the first protrusion on the side away from the electrode assembly.

[0007] In an example of the cylindrical battery of the present invention, along the thickness direction of the end cover, the surface of the ring body on the side away from the electrode assembly is flush with the first end surface or exceeds the first end surface in the direction away from the electrode assembly.

[0008] In an example of the cylindrical battery of the present invention, along the thickness direction of the end cover, the radial dimension L between the inner edge of the orthographic projection contour of the ring body and the outer edge of the first end face is 0.5-6 mm.

[0009] In an example of the cylindrical battery of the utility model, the end cover also includes a second protrusion, which is arranged on the surface of the first protrusion away from the electrode assembly and protrudes away from the electrode assembly, and the welding surface is located on the surface of the second protrusion away from the electrode assembly.

[0010] In an example of the cylindrical battery of the present invention, the cylindrical battery further includes an electrode terminal insulated and connected to the end cover, the electrode terminal passes through the end cover and is electrically connected to the electrode assembly, and the polarity of the electrode terminal is opposite to that of the end cover.

[0011] In an example of the cylindrical battery of the present invention, along the thickness direction of the end cover, the welding surface is flush with the surface of the electrode terminal on the side away from the electrode assembly.

[0012] In an example of a cylindrical battery of the utility model, the ring body portion includes a recessed portion and a connecting portion, the connecting portion is connected to the outer periphery of the first convex portion around the periphery, and the recessed portion is connected to the outer periphery of the connecting portion around the periphery; along the thickness direction of the end cover, the recessed portion is recessed from the connecting portion toward the electrode assembly side, and the side of the recessed portion facing the electrode assembly includes a third convex portion, and the third convex portion is embedded in the opening.

[0013] In an example of the cylindrical battery of the utility model, the ring body also includes a stopper, which is arranged around the side of the recess away from the connecting portion along the radial direction of the end cover, and the stopper is at least partially overlapped and welded with the first end face.

[0014] In an example of a cylindrical battery of the present invention, the ring body portion includes a first ring portion and a second ring portion, the first ring portion is arranged around the outer circumference of the first protrusion, and the second ring portion is arranged around the outer circumference of the first ring portion; along the thickness direction of the end cover, on the side away from the electrode assembly, the surface of the first ring portion and the surface of the second ring portion are coplanar, and on the side facing the electrode assembly, the first ring portion protrudes toward one side of the electrode assembly relative to the second ring portion to form a step surface between the first ring portion and the second ring portion, and the first end face is at least partially embedded in the step surface.

[0015] In an example of the cylindrical battery of the present invention, the radial inner side of the first end surface includes a positioning notch, and the outer periphery of the ring body is at least partially accommodated in the positioning notch.

[0016] The utility model also provides an electronic device, which includes the cylindrical battery in any of the above examples.

[0017] In the cylindrical battery of the utility model, since the weld mark formed between the outer edge of the end cover and the first end face along the thickness direction of the end cover is located between the welding surface and the electrode assembly, when the electrical connectors such as the bus bar outside the cylindrical battery are in contact with the welding surface for welding, the probability of the bus bar extending to the area above the weld mark contacting the weld mark will be reduced, thereby improving the degree of fit between the bus bar and the welding surface, thereby improving the welding quality between the bus bar and the welding surface and ensuring the stability of the output current on the end cover side of the cylindrical battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the utility model. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying creative work.

[0019] Figure 1 A three-dimensional view of an embodiment of a cylindrical battery of the utility model;

[0020] Figure 2 This is an axial cross-sectional view of an embodiment of a cylindrical battery of the utility model;

[0021] Figure 3 for Figure 2 A partial enlarged view of the middle A area;

[0022] Figure 4 for Figure 3 A partial enlarged view of the welding position of the welding portion and the side wall in the embodiment shown;

[0023] Figure 5 This is a schematic diagram of the structure in which the welding surface of an embodiment of a cylindrical battery of the utility model is located at the second convex part;

[0024] Figure 6 This is a schematic structural diagram of a cylindrical battery in an embodiment of the utility model in which a concave portion is provided at a welding portion;

[0025] Figure 7 for Figure 6 A partial enlarged view of the welding position between the concave portion and the side wall in the illustrated embodiment;

[0026] Figure 8 This is a structural schematic diagram of a cylindrical battery in an embodiment of the utility model in which a stopper is provided at a welding portion;

[0027] Fig. 9 for Figure 8 A partial enlarged view of the welding position between the stopper and the side wall in the embodiment shown;

[0028] Fig.10This is a structural schematic diagram of a cylindrical battery in an embodiment of the utility model in which a positioning platform is provided at a welding portion;

[0029] Fig.11 for Fig.10 A partial enlarged view of the welding position between the positioning platform and the side wall in the embodiment shown;

[0030] Fig.12 This is a schematic diagram of a structure in which a sink is provided at the opening position of the side wall of a cylindrical battery in one embodiment of the utility model;

[0031] Fig.13 for Fig.12 A partial enlarged view of the welding portion and the sink installation position in the embodiment shown;

[0032] Fig.14 This is a schematic diagram of the structure of a cylindrical battery of the utility model installed on a vehicle.

[0033] Component number description

[0034] 100, cylindrical battery; 110, shell; 111, side wall; 112, opening; 113, first end face; 114, positioning notch; 115, end wall; 120, electrode assembly; 121, first pole ear; 122, second pole ear; 123, first current collecting member; 124, second current collecting member; 130, end cover; 1301, terminal hole; 131, welding surface; 132, ring body; 1321, concave portion; 13211, third convex portion ; 1322, stopper portion; 1323, connecting portion; 1324, first ring portion; 1325, second ring portion; 1326, step surface; 133, first convex portion; 134, second convex portion; 140, weld mark; 150, electrode terminal; 151, conductive portion; 152, first fixing portion; 153, second fixing portion; 160, first insulating member; 170, second insulating member; 180, sealing member; 200, electronic device; 210, working portion. DETAILED DESCRIPTION

[0035] The following describes the implementation of the present invention through specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific implementations, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following embodiments and the features in the embodiments can be combined with each other without conflict. It should also be understood that the terms used in the embodiments of the present invention are intended to describe specific implementation schemes, rather than to limit the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are usually carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0036] When numerical ranges are given in the embodiments, it should be understood that unless otherwise specified in the present invention, both endpoints of each numerical range and any value between the two endpoints can be selected. Unless otherwise defined, all technical and scientific terms used in the present invention are in accordance with the prior art mastery of those skilled in the art and the description of the present invention, and any prior art methods, equipment and materials similar or equivalent to the methods, equipment and materials in the embodiments of the present invention can also be used to implement the present invention.

[0037] It should be noted that the terms such as "upper", "lower", "left", "right", "middle" and "one" cited in this specification are only for the convenience of description and are not used to limit the scope of implementation of the present utility model. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present utility model without substantially changing the technical content.

[0038] See also Figures 1 to 14 The utility model provides a cylindrical battery 100 and an electronic device 200, wherein a welding surface 131 for electrically connecting to the outside of the cylindrical battery 100 is provided on the end cap 130, and a welding mark 140 formed by welding the outer edge of the end cap 130 and the side wall 111 is located between the welding surface 131 and the electrode assembly 120, thereby improving the degree of adhesion between external electrical connectors such as bus bars and the welding surface 131, thereby improving the welding quality between external electrical connectors such as bus bars and the welding surface 131, and ensuring the stability of the output current on the end cap 130 side of the cylindrical battery 100.

[0039] See also Figure 1 to Figure 2 , the cylindrical battery 100 includes: a shell 110, an electrode assembly 120 and an end cap 130. A accommodating cavity is formed in the shell 110 for accommodating the electrode assembly 120, an electrolyte (not shown) and other components. The shell 110 can be open at one end or at both ends. Specifically, the size of the shell 110 can be determined according to the specific size of the electrode assembly 120. The material of the shell 110 can be various, such as copper, iron, aluminum, steel, aluminum alloy, etc. In order to prevent the shell 110 from rusting during long-term use, a layer of rust-proof material, such as metal nickel, etc., can also be plated on the surface of the shell 110.

[0040] like Figure 1 and Figure 2As shown, the housing 110 includes an end wall 115 and a side wall 111 surrounding the end wall 115. Along the axial direction of the cylindrical battery 100, the housing 110 is set as a closed end on one side of the end wall 115, and the housing 110 includes an opening 112 at the end opposite to the end wall 115, and the side of the opening 112 is set as an open end. The fixing method of the end wall 115 on the side wall 111 is not limited. For example, the end wall 115 can be integrally formed and connected with the side wall 111, or it can be formed separately and then welded to the side wall 111.

[0041] See also Figure 1 and Figure 2 In an embodiment of the cylindrical battery 100 of the utility model, the shell 110 is a cylindrical structure, the shell 110 includes an end wall 115 and a side wall 111 surrounding the end wall 115, the shell 110 includes a closed end and an open end, the end wall 115 is a closed end, and the opening 112 opposite to the end wall 115 is an open end. The end wall 115 and the side wall 111 can be integrally formed and connected, or they can be formed separately and then welded. Preferably, in this embodiment, the end wall 115 and the side wall 111 are welded.

[0042] like Figure 2 and Figure 3 As shown, the electrode assembly 120 is contained in the housing 110. The electrode assembly 120 is a component in the cylindrical battery 100 where an electrochemical reaction occurs. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is usually provided between the positive electrode sheet and the negative electrode sheet. The positive electrode sheet includes a positive electrode collector and a positive electrode active material layer, and the positive electrode active material layer is coated on the surface of the positive electrode collector; the positive electrode collector includes a positive electrode coating area and a positive electrode ear connected to the positive electrode coating area, the positive electrode coating area is coated with a positive electrode active material layer, and the positive electrode ear is not coated with a positive electrode active material layer. The negative electrode sheet includes a negative electrode collector and a negative electrode active material layer, and the negative electrode active material layer is coated on the surface of the negative electrode collector; the negative electrode collector includes a negative electrode coating area and a negative electrode ear connected to the negative electrode coating area, the negative electrode coating area is coated with a negative electrode active material layer, and the negative electrode ear is not coated with a negative electrode active material layer. Taking lithium-ion batteries as an example, the material of the positive electrode current collector can be aluminum, and the positive electrode active material layer includes the positive electrode active material, which can be lithium cobalt oxide, lithium iron phosphate, ternary lithium or lithium manganese oxide. The material of the negative electrode current collector can be copper, and the negative electrode active material layer includes the negative electrode active material, which can be carbon or silicon. The main matrix material of the diaphragm can be PP or PE. In order to protect and insulate the electrode assembly 120, an insulating film can also be coated on the outside of the electrode assembly 120. The insulating film can be synthesized from PP, PE, PET, PVC or other high molecular polymer materials.

[0043] Please continue reading Figure 2 In an example of the cylindrical battery 100 of the utility model, the electrode assembly 120 is sealed and installed in the housing 110. The electrode assembly 120 is respectively provided with a first pole ear 121 and a second pole ear 122 at both ends of the height direction of the cylindrical battery 100, and the polarities of the first pole ear 121 and the second pole ear 122 are opposite, wherein the first pole ear 121 faces the side of the opening 112, the first pole ear 121 is a positive pole ear, and the second pole ear 122 is a negative pole ear. It should be noted that in other embodiments, the first pole ear 121 can also be a negative pole ear, and the second pole ear 122 can be a positive pole ear.

[0044] See also Figure 3 The end face of the side wall 111 on the side of the opening 112 is the first end face 113, the end cover 130 covers the opening 112, and the outer edge of the end cover 130 is arranged close to the first end face 113, and is welded with the first end face 113 to form a weld mark 140. The structural form of the welding connection between the outer edge of the end cover 130 and the first end face 113 is not limited. For example, the outer edge of the end cover 130 may overlap the first end face 113, and the welding laser may weld the side of the outer edge of the end cover 130 away from the first end face 113, thereby forming a laser penetration weld between the outer edge of the end cover 130 and the first end face 113; or the outer edge of the end cover 130 may abut against the inner wall of the shell 110, and the welding laser may weld the butt joint between the outer edge of the end cover 130 and the first end face 113, thereby forming a butt weld between the first end face 113 and the outer edge of the end cover 130, etc.

[0045] When the end cap 130 is electrically connected to the electrode assembly 120, it can be electrically connected to the first pole ear 121 or the second pole ear 122, which is specifically determined by the polarity requirement of the electrical connection of the end cap 130. In this embodiment, the end cap 130 is electrically connected to the second pole ear 122, that is, the end cap 130 is the negative output terminal. The electrical connection method can be that the second pole ear 122 is directly electrically connected to the shell 110, the end cap 130 is electrically connected to the second pole ear 122 by welding to the shell 110, or the second pole ear 122 is electrically connected to the shell 110 through a current collecting member, and the end cap 130 is electrically connected to the second pole ear 122 by welding to the shell 110. Preferably, please refer to Figure 2 In this embodiment, the electrode assembly 120 is provided with a second current collecting component 124 at the end of the second pole ear 122, and the second pole ear 122 is electrically connected to the shell 110 through the second current collecting component 124, and then the electrical connection between the end cover 130 and the second pole ear 122 is achieved by welding the end cover 130 to the shell 110.

[0046] See also Figures 2 to 4The side of the end cap 130 facing away from the electrode assembly 120 includes a welding surface 131 for external electrical connection with the cylindrical battery 100. Electrical connection refers to the series connection, parallel connection or series-parallel connection between adjacent cylindrical batteries 100 when multiple cylindrical batteries 100 are assembled in groups. The welding surface 131 is usually welded to an external electrical connector such as a bus bar to achieve electrical connection between multiple cylindrical batteries 100. The welding surface 131 can be an annular surface structure, a circular surface structure, a rectangular surface structure or other special-shaped surface structures, etc., to meet the welding strength and flow conduction area requirements between the external bus bar and the end cap 130. Figure 3 and Figure 4 As shown, along the thickness direction of the end cap 130, the weld mark 140 formed by welding the outer edge of the end cap 130 to the first end face 113 is located between the welding surface 131 and the electrode assembly 120. In this way, a height difference h can be formed between the welding surface 131 and the weld mark 140, so that the weld mark 140 does not protrude to the side of the welding surface 131 away from the electrode assembly 120. Therefore, when the external busbar is in contact with the welding surface 131 for welding, the busbar extending to the area above the weld mark 140 will not contact the weld mark 140 below, thereby ensuring that the area of ​​the busbar located at the position of the welding surface 131 can be effectively attached to the welding surface 131, thereby improving the welding quality between the busbar and the welding surface 131, and ensuring the stability of the output current on the end cap 130 side of the cylindrical battery 100.

[0047] In order to facilitate the conduction between the first pole tab 121 end of the electrode assembly 120 and the outside of the cylindrical battery 100, an electrode terminal 150 is generally provided on the end cover 130 or the end wall 115. The electrode terminal 150 is electrically connected to the first pole tab 121. The external busbar can be electrically connected to the first pole tab 121 by welding with the electrode terminal 150. In an example of the cylindrical battery 100 of the present invention, please refer to Figure 2 and Figure 3The cylindrical battery 100 further includes an electrode terminal 150, which is insulated and connected to the end cap 130 and electrically connected to the first pole tab 121. The electrode terminal 150 may be directly electrically connected to the first pole tab 121, or may be indirectly electrically connected to the first pole tab 121 through a current collecting member. Preferably, in this embodiment, the electrode assembly 120 is provided with a first current collecting member 123 at the end of the first pole tab 121, and the electrode terminal 150 is electrically connected to the first pole tab 121 through the first current collecting member 123. Since the first pole tab 121 and the second pole tab 122 have opposite polarities, the polarity of the electrode terminal 150 is also opposite to that of the end cap 130. In this arrangement, since the electrode terminal 150 is arranged on the end cover 130, and the polarity of the electrode terminal 150 is opposite to the polarity of the end cover 130, the positive and negative electrodes of the cylindrical battery 100 can be arranged on the same side, which can simplify the design and manufacturing process of the cylindrical battery 100. When the cylindrical batteries 100 are grouped, since the positive and negative electrodes of adjacent cylindrical batteries 100 are located on the same side, the electrical connection between the cylindrical batteries 100 can be facilitated, and the length of the connecting leads inside the battery module can be reduced.

[0048] Specifically, see Figure 3 , the end cap 130 includes a terminal hole 1301, and the electrode terminal 150 is installed through the terminal hole 1301. The shape of the terminal hole 1301 can be a circular hole, a square hole or other polygonal structures, as long as the fixed connection requirements of the electrode terminal 150 and the end cap 130 are met. The terminal hole 1301 can be set in the central area of ​​the end cap 130, or in the outer peripheral area of ​​the end cap 130, corresponding to the installation position of the electrode terminal 150. In this embodiment, the terminal hole 1301 is a circular hole structure, and the terminal hole 1301 is coaxially arranged with the end cap 130.

[0049] Specifically, see Figure 3 The electrode terminal 150 includes a conductive part 151, a first fixing part 152 and a second fixing part 153. The conductive part 151 is a cylindrical structure and passes through the terminal hole 1301. The first fixing part 152 is arranged in the circumference of the outer end of the conductive part 151 and is clamped on the outer side of the end cover 130. The second fixing part 153 is arranged in the circumference of the inner end of the conductive part 151 and is clamped on the inner side of the end cover 130. The electrode terminal 150 is insulated and isolated from the end cover 130 by the first insulating member 160 and the second insulating member 170, respectively, and the terminal hole 1301 is sealed by the first fixing part 152 pressing the sealing member 180. The first insulating member 160 is disposed between the first fixing portion 152 and the outer wall of the end cover 130 to insulate the electrode terminal 150 from the outer wall of the end cover 130 ; the second insulating member 170 is installed between the second fixing portion 153 and the inner wall of the end cover 130 to insulate the electrode terminal 150 from the inner wall of the end cover 130 .

[0050] In an example of the cylindrical battery 100 of the utility model, the end cap 130 includes a first convex portion 133 and an annular portion 132. The annular portion 132 is arranged around the outer periphery of the first convex portion 133 and welded to the first end face 113. The weld mark 140 formed by welding is at least partially located on the annular portion 132. The first convex portion 133 protrudes toward the side away from the electrode assembly 120 relative to the annular portion 132. The specific shapes of the annular portion 132 and the first convex portion 133 are not limited. For example, the first convex portion 133 can be a cylindrical convex structure, and the annular portion 132 is a circular ring structure arranged around the outer periphery of the first convex portion 133; or the first convex portion 133 can be a rectangular convex structure, and the annular portion 132 is an irregular annular structure arranged around the outer periphery of the first convex portion 133. Preferably, in this embodiment, the first convex portion 133 is an approximately cylindrical convex structure, and the annular portion 132 is a circular ring structure arranged coaxially around the first convex portion 133. Such a configuration facilitates the positioning processing of the first protrusion 133 on the end cover 130 .

[0051] The first protrusion 133 can be formed in any manner, for example, it can be a convex block structure connected to the ring body 132, or a cavity structure stamped in a direction away from the electrode assembly 120 relative to the ring body 132, etc., as long as the first protrusion 133 is protruding in a direction away from the electrode assembly 120 relative to the ring body 132. In order to facilitate the forming process of the first protrusion 133 and reduce the weight of the end cap 130, preferably, refer to Figure 3 and Figure 4 In the present embodiment, the first protrusion 133 is a cavity structure formed by stamping relative to the ring body 132. The welding surface 131 is located on the surface of the first protrusion 133 on the side away from the electrode assembly 120. The welding surface 131 can be a circular surface, an annular surface or other special-shaped surface, etc., which is specifically related to the structural shape of the first protrusion 133. In the present embodiment, the surface of the first protrusion 133 on the side away from the electrode assembly 120 is a circular surface. The welding surface 131 can be a partial area of ​​the surface of the first protrusion 133 on the side away from the electrode assembly 120, or it can be the entire surface area, subject to satisfying the welding area requirement of the welding surface 131. In this embodiment, a first protrusion 133 is provided on the end cover 130, and a welding surface 131 is provided on the surface of the first protrusion 133 on the side away from the electrode assembly 120. This ensures that a height difference H is formed between the welding surface 131 and the ring body 132. By reasonably controlling the size of the height difference H, a height difference h is formed between the weld mark 140 formed by welding the ring body 132 to the first end face 113 and the welding surface 131, so as to ensure that the area of ​​the busbar located at the position of the welding surface 131 can be effectively fitted with the welding surface 131.

[0052] On the end cap 130 side, the electrode terminal 150 can pass through the ring body 132 to be electrically connected to the electrode assembly 120, or pass through the first protrusion 133 to be electrically connected to the electrode assembly 120. Preferably, in an example of the cylindrical battery 100 of the present invention, refer to Figure 3 , the electrode terminal 150 passes through the top wall of the first protrusion 133 and is electrically connected to the electrode assembly 120. The electrode terminal 150 can be coaxially arranged with the first protrusion 133, or can be non-coaxially arranged. The electrode terminal 150 passes through the top wall of the first protrusion 133 and is electrically connected to the first electrode tab 121. In order to facilitate the positioning of the electrode terminal 150 on the first protrusion 133, preferably, in this embodiment, the electrode terminal 150 is coaxially arranged with the first protrusion 133, that is, the electrode terminal 150 passes through the central area of ​​the first protrusion 133. Since a concave cavity is formed on the side of the first protrusion 133 facing the electrode assembly 120, the electrode terminal 150 is arranged to pass through the top wall of the first protrusion 133, so that the portion of the electrode terminal 150 located inside the shell 110 can be partially accommodated in the concave cavity, thereby reducing the internal height space of the shell 110 occupied by the electrode terminal 150, which is beneficial to improving the volume energy density of the cylindrical battery 100; at the same time, the surface of the electrode terminal 150 facing away from the electrode assembly 120 protrudes from the welding surface 131. In this way, when the electrode terminal 150 is welded to the corresponding bus bar, no interference will be formed between the welding surface 131.

[0053] See also Figure 3 and Figure 4 In an example of the cylindrical battery 100 of the utility model, along the thickness direction of the end cover 130, the surface of the ring body 132 away from the electrode assembly 120 is flush with the first end surface 113, so that Figure 4 As shown, the welding quality when the outer periphery of the ring body 132 matches the inner wall of the side wall 111 for welding can be improved. When this welding method is adopted, the weld mark 140 formed is located on the surface of the ring body 132 on the side away from the electrode assembly 120 and the first end face 113, which is conducive to the welding between the ring body 132 and the first end face 113. In other embodiments, the surface of the ring body 132 on the side away from the electrode assembly 120 can also protrude from the first end face 113 in the direction away from the electrode assembly 120. In this way, the ring body 132 can overlap the first end face 113 on the side facing the electrode assembly 120 for welding.

[0054] Preferably, in another embodiment, the height difference H between the surface of the ring body 132 on the side away from the electrode assembly 120 and the welding surface 131 is any value in the range of 0.05 to 2 mm, for example, it can be 0.05 mm, 0.5 mm, 1.0 mm or 2 mm. The height difference H is set to 0.05 to 2 mm, so that the height of the weld mark 140 can be lower than the height of the welding surface 131, and then it can be ensured that there is always a height difference h between the welding surface 131 and the weld mark 140, avoiding contact between the busbar and the weld mark 140, so as to ensure that the area of ​​the busbar located at the position of the welding surface 131 can be effectively attached to the welding surface 131. Further, in another embodiment of the utility model, the height difference H is any value in the range of 0.1 to 0.6 mm, for example, it can be 0.1 mm, 0.3 mm or 0.6 mm, so that it can further ensure that the area of ​​the busbar located at the position of the welding surface 131 can be effectively attached to the welding surface 131.

[0055] In order to ensure the welding strength requirement between the ring body 132 and the side wall 111, the weld mark 140 formed between the ring body 132 and the side wall 111 needs to have a certain radial width. Figure 3 and Figure 4 , along the thickness direction of the end cover 130, the radial dimension L between the inner edge of the orthographic projection contour of the ring body 132 and the outer edge of the first end face 113 is any value within the range of 0.5 to 6 mm, for example, it can be 0.5 mm, 1.0 mm, 3 mm or 6 mm. The inner edge of the orthographic projection contour of the ring body 132 refers to the edge contour at the position where the ring body 132 and the first convex portion 133 are connected, and the outer edge of the first end face 113 refers to the contour of the first end face 113 away from the axis of the shell 110. Along the circumferential direction of the end cover 130, the radial dimension L between the inner edge of the orthographic projection contour of the ring body 132 and the outer edge of the first end face 113 can be set equally or unequally, as long as the radial dimension L between the inner edge of the orthographic projection contour of the ring body 132 and the outer edge of the first end face 113 is within the range of 0.5 to 6 mm. Preferably, along the circumferential direction of the end cap 130, the inner edge of the orthographic projection contour of the ring body 132 and the outer edge of the first end face 113 are coaxially arranged circular contours, so the radial dimension L between the inner edge of the orthographic projection contour of the ring body 132 and the outer edge of the first end face 113 is equal. This arrangement facilitates the control of the dimension L, and also facilitates the control of the forming accuracy of the weld stamp 140 in the radial direction. In this embodiment, by setting the radial dimension L to be greater than or equal to 0.5 to 6 mm, the strength requirements of the welded connection between the end cap 130 and the side wall 111 in most conventional cylindrical batteries 100 can be met.

[0056] Preferably, in another embodiment of the present invention, the radial dimension L is any value within the range of 0.5 to 3 mm, for example, 0.5 mm, 1.0 mm, 2.0 mm or 3 mm, etc. This setting can further limit the size of the radial dimension L, so as to better meet the strength requirements of the welding connection between the end cover 130 and the side wall 111 in the conventional cylindrical battery 100.

[0057] See also Figure 5 In an example of the cylindrical battery 100 of the utility model, the end cap 130 further includes a second protrusion 134, which is disposed on the surface of the first protrusion 133 on the side away from the electrode assembly 120 and protrudes away from the electrode assembly 120, and the welding surface 131 is located on the surface of the second protrusion 134 on the side away from the electrode assembly 120. The second protrusion 134 can be an annular protrusion structure disposed on the surface of the first protrusion 133 on the side away from the electrode assembly 120, or it can be a plurality of dispersed protrusion structures disposed on the surface of the first protrusion 133 on the side away from the electrode assembly 120. The height dimension of the second protrusion 134 protruding from the surface of the first protrusion 133 on the side away from the electrode assembly 120 is not limited, and is subject to the welding height requirement of the welding surface 131. Preferably, in this embodiment, the second protrusion 134 is an annular protrusion structure disposed on the surface of the first protrusion 133 on the side away from the electrode assembly 120. The surface of the second protrusion 134 facing away from the electrode assembly 120 is a toroidal surface structure, and accordingly, the welding surface 131 is also a toroidal surface structure. By setting the second protrusion 134 on the surface of the first protrusion 133 facing away from the electrode assembly 120, and making the welding surface 131 located on the surface of the second protrusion 134 facing away from the electrode assembly 120, not only can the height difference between the welding surface 131 and the ring body 132 be further increased, thereby increasing the height difference between the welding surface 131 and the weld mark 140, but also it is more conducive to avoiding contact between the busbar and the weld mark 140, and better ensuring that the area of ​​the busbar located at the position of the welding surface 131 can be effectively fitted with the welding surface 131. At the same time, the provision of the second protrusion 134 can also enhance the rigidity of the end cover 130, reduce the probability of deformation of the end cover 130 side during the expansion of the cylindrical battery 100, and further improve the reliability of the welding connection of the busbar at the position of the welding surface 131.

[0058] On the premise that both the welding surface 131 and the electrode terminal 150 meet the requirements for welding with external conductive parts, the height relationship between the welding surface 131 and the surface of the electrode terminal 150 facing away from the electrode assembly 120 is not limited in this application, but preferably, refer to Figure 5In this embodiment, along the thickness direction of the end cap 130, the welding surface 131 is flush with the surface of the electrode terminal 150 on the side facing away from the electrode assembly 120. In this embodiment, the surface flushness in the thickness direction of the end cap 130 can allow an error of ±0.5 mm. Since the polarity of the welding surface 131 is the same as that of the end cap 130, and the polarity of the end cap 130 is opposite to that of the electrode terminal 150, the polarity of the welding surface 131 is opposite to that of the electrode terminal 150, and the welding surface 131 is flush with the surface of the side of the electrode terminal 150 facing away from the electrode assembly 120. In this way, when the cylindrical batteries 100 are assembled in groups, the heights of the positive and negative welding surfaces between adjacent cylindrical batteries 100 are in the same plane, so that when the bus bar connects the positive and negative electrodes, there is no need to bend in the height direction. The planar structure can be used to achieve flush welding of the two ends of the bus bar with the surface of the side of the electrode terminal 150 facing away from the electrode assembly 120 and the welding surface 131, thereby simplifying the structure of the bus bar, reducing the processing cost of the bus bar, and also reducing the mass of the bus bar, which is more conducive to improving the mass energy density of the battery module.

[0059] When the ring body 132 is welded to the side wall 111, the tighter the outer periphery of the ring body 132 fits to the inner wall of the side wall 111, the better the welding strength formed at this position, but the ring body 132 is less likely to be clamped into the inside of the side wall 111, which affects the assembly efficiency and assembly quality between the end cap 130 and the side wall 111. In view of this, in an example of the cylindrical battery 100 of the present invention, please refer to Figure 6 and Figure 7 The ring body 132 includes a recessed portion 1321 and a connecting portion 1323. The connecting portion 1323 surrounds and connects to the outer periphery of the first protruding portion 133, and the recessed portion 1321 surrounds and connects to the outer periphery of the connecting portion 1323. Along the thickness direction of the end cap 130, the recessed portion 1321 is recessed from the connecting portion 1323 toward the electrode assembly 120. The side of the recessed portion 1321 facing the electrode assembly 120 includes a third protruding portion 13211. The third protruding portion 13211 matches the opening 112 and is embedded in the opening 112 to achieve the positioning installation of the end cap 130 at the position of the opening 112. At the same time, due to the provision of the recessed portion 1321, the probability of the third protruding portion 13211 being stuck when being embedded in the opening 112 can be reduced during the process of installing the end cap 130 to the opening 112, thereby improving the installation efficiency of the end cap 130.

[0060] See also Figure 8 and Fig. 9In an example of the cylindrical battery 100 of the utility model, the ring body 132 also includes a stopper 1322. Along the radial direction of the end cap 130, the stopper 1322 is arranged around the side of the recess 1321 away from the connecting portion 1323, and the stopper 1322 extends along the circumferential outer edge of the recess 1321 to the side away from the connecting portion 1323. Along the thickness direction of the end cap 130, the side of the stopper 1322 facing the electrode assembly 120 is at least partially overlapped and welded with the first end face 113. The stopper 1322 can be an annular structure arranged around the outer periphery of the recess 1321, or it can be a plurality of dispersed block structures arranged around the outer periphery of the recess 1321, as long as when the end cap 130 is installed at the opening 112, the side of the stopper 1322 facing the electrode assembly 120 can at least partially overlap with the first end face 113. Preferably, in this embodiment, the stopper 1322 is an annular structure arranged around the outer periphery of the recess 1321, and the stopper 1322 and the recess 1321 are arranged coaxially, so as to facilitate the positioning processing between the recess 1321 and the stopper 1322. By providing the stopper 1322, when the end cover 130 is installed at the opening 112, the stopper 1322 at the outer periphery of the end cover 130 can overlap the first end surface 113, thereby limiting the displacement of the end cover 130 in the direction of the electrode assembly 120, and realizing the positioning installation of the end cover 130 in the axial direction of the side wall 111.

[0061] It should be noted that when the ring body 132 is welded to the side wall 111, the welding laser can perform penetration welding on the stopper 1322 and the first end face 113 from above the stopper 1322 to form a Fig. 9 Of course, in other embodiments, the welding laser can also perform butt welding on the butt joint of the stopper 1322 and the first end face 113 from the radial direction of the side wall 111 to form the corresponding weld mark 140, as long as the weld mark 140 is at least partially located on the first end face 113 and the stopper 1322.

[0062] See also Fig.10 and Fig.11In another example of the cylindrical battery 100 of the utility model, the ring body 132 includes a first ring part 1324 and a second ring part 1325, wherein the first ring part 1324 is disposed around the outer periphery of the first protrusion 133, and the second ring part 1325 is disposed around the outer periphery of the first ring part 1324. The first ring part 1324 and the second ring part 1325 may be coaxially disposed circular ring structures, or may be non-coaxially disposed annular structures. Preferably, in the present embodiment, the first ring part 1324 and the second ring part 1325 are annular structures coaxially disposed with the first protrusion 133, and such an arrangement facilitates the positioning processing between the first ring part 1324, the second ring part 1325 and the first protrusion 133. Along the thickness direction of the end cap 130, on the side away from the electrode assembly 120, the surface of the first ring part 1324 and the surface of the second ring part 1325 are coplanar, and such an arrangement can form a larger area of ​​welding area on the side of the ring body 132 away from the electrode assembly 120, and facilitate the forming of the weld stamp 140. When facing the electrode assembly 120, the first ring portion 1324 protrudes toward one side of the electrode assembly 120 relative to the second ring portion 1325 to form a step surface 1326 between the first ring portion 1324 and the second ring portion 1325. The specific height of the step surface 1326 is not limited, as long as the installation relationship between the end cover 130, the side wall 111, and the electrode assembly 120 is satisfied. The first end face 113 is embedded in the step surface 1326. Along the radial direction of the end cover 130, the first end face 113 can be completely embedded in the step surface 1326, or partially embedded in the step surface 1326. In this embodiment, by setting the step surface 1326 on the ring body 132 and embedding the first end face 113 in the step surface 1326, when the end cover 130 is installed to the opening 112, the installation position between the end cover 130 and the side wall 111 can be simultaneously positioned in the axial and radial directions.

[0063] See also Fig.12 and Fig.13 In an example of the cylindrical battery 100 of the utility model, the radial inner side of the first end face 113 includes a positioning notch 114, and the outer periphery of the ring body 132 is at least partially accommodated in the positioning notch 114. There are many ways to accommodate the outer periphery of the ring body 132 in the positioning notch 114. For example, the positioning notch 114 can be an integral annular notch arranged along the circumference of the first end face 113, and the outer periphery of the ring body 132 is accommodated in the positioning notch 114 along the circumference; the positioning notch 114 can also be a plurality of local notch structures dispersedly arranged along the circumference of the first end face 113, and the outer periphery of the ring body 132 is correspondingly provided with a plurality of protrusions, and the protrusions are correspondingly accommodated in the positioning notch 114, so that the outer periphery of the ring body 132 is accommodated in the positioning notch 114. By providing the positioning notch 114 in the side wall 111, the outer periphery of the ring body 132 is accommodated in the positioning notch 114, and the positioning installation between the end cover 130 and the side wall 111 can also be achieved.

[0064] See also Fig.14 In an embodiment of the electronic device 200 of the utility model, the electronic device 200 can be a vehicle, a mobile phone, a portable device, a laptop computer, a ship, a spacecraft, an electric toy, an electric tool, etc., and can also be a battery pack, a battery module, etc. assembled from a plurality of the above cylindrical batteries 100. The vehicle can be a fuel vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle can be a pure electric vehicle, a hybrid vehicle or an extended-range vehicle, etc.; the spacecraft includes an airplane, a rocket, a space shuttle and a spacecraft, etc.; the electric toy includes a fixed or mobile electric toy, such as a game console, an electric car toy, an electric ship toy and an electric airplane toy, etc.; the electric tool includes a metal cutting electric tool, a grinding electric tool, an assembly electric tool and a railway electric tool, such as an electric drill, an electric grinder, an electric wrench, an electric screwdriver, an electric hammer, an impact drill, a concrete vibrator and an electric planer, etc.

[0065] The embodiment of the utility model does not impose any special restrictions on the above-mentioned electronic device 200. In one embodiment of the electronic device 200 of the utility model, the electronic device 200 is a vehicle, and the vehicle includes a working part 210, and the working part 210 includes the cylindrical battery 100 in the above-mentioned embodiment, and the cylindrical battery 100 is fixedly installed on the vehicle body, thereby providing driving force for the vehicle to realize the operation of the vehicle.

[0066] In the cylindrical battery of the utility model, since the weld mark formed between the outer edge of the end cover and the first end face along the thickness direction of the end cover is located between the welding surface and the electrode assembly, when the electrical connectors such as the busbar outside the cylindrical battery contact and weld with the welding surface, the probability of the busbar extending to the area above the weld mark contacting with the weld mark will be reduced, and the degree of fit between the busbar and the welding surface will be improved, thereby improving the welding quality between the busbar and the welding surface and ensuring the stability of the output current on the end cover side of the cylindrical battery. Therefore, the utility model effectively overcomes some practical problems in the prior art and has a high utilization value and use significance. The above embodiments are only illustrative of the principles and effects of the utility model, and are not used to limit the utility model. Anyone familiar with this technology can modify or change the above embodiments without violating the spirit and scope of the utility model. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the relevant technical field without departing from the spirit and technical ideas disclosed by the utility model should still be covered by the claims of the utility model.

Claims

1. A cylindrical battery, characterized in that: include: A shell, comprising a side wall, wherein one end of the side wall along the axial direction of the cylindrical battery comprises an opening, and an end surface of the side wall on the side of the opening is a first end surface; An electrode assembly is disposed in the housing; an end cap, covering the opening and electrically connected to the electrode assembly; an outer edge of the end cap is welded to the first end surface to form a weld mark; The side of the end cap facing away from the electrode assembly includes a welding surface for electrical connection with the outside of the cylindrical battery; along the thickness direction of the end cap, the weld mark is located between the welding surface and the electrode assembly.

2. The cylindrical battery according to claim 1, characterized in that: The end cover includes a first protrusion and a ring body, the ring body is arranged around the outer circumference of the first protrusion and welded to the first end face, the weld mark is at least partially located on the ring body, the first protrusion protrudes relative to the ring body toward a side away from the electrode assembly, and the welding surface is located on the surface of the first protrusion on a side away from the electrode assembly.

3. The cylindrical battery according to claim 2, characterized in that: Along the thickness direction of the end cover, a surface of the ring body portion on a side away from the electrode assembly is flush with the first end surface or exceeds the first end surface in a direction away from the electrode assembly.

4. The cylindrical battery according to claim 3, characterized in that: Along the thickness direction of the end cover, a radial dimension L between an inner edge of the orthographic projection contour of the ring body and an outer edge of the first end surface is 0.5 to 6 mm.

5. The cylindrical battery according to claim 2, characterized in that: The end cap also includes a second protrusion, which is arranged on the surface of the first protrusion away from the electrode assembly and protrudes away from the electrode assembly. The welding surface is located on the surface of the second protrusion away from the electrode assembly.

6. The cylindrical battery according to any one of claims 2 to 5, characterized in that: The cylindrical battery further includes an electrode terminal insulated and connected to the end cap, the electrode terminal penetrates the end cap and is electrically connected to the electrode assembly, and the polarity of the electrode terminal is opposite to that of the end cap.

7. The cylindrical battery according to claim 6, characterized in that: Along the thickness direction of the end cover, the welding surface is flush with the surface of the electrode terminal on a side facing away from the electrode assembly.

8. The cylindrical battery according to claim 6, characterized in that: The annular body includes a recessed portion and a connecting portion, wherein the connecting portion is connected to the outer periphery of the first convex portion in a surrounding manner, and the recessed portion is connected to the outer periphery of the connecting portion in a surrounding manner; along the thickness direction of the end cover, the recessed portion is recessed from the connecting portion toward the electrode assembly side, and the side of the recessed portion facing the electrode assembly includes a third convex portion, and the third convex portion is embedded in the opening.

9. The cylindrical battery according to claim 8, characterized in that: The annular body also includes a stopper, which is disposed around a side of the recess away from the connecting portion along the radial direction of the end cover, and the stopper is at least partially overlapped and welded with the first end surface.

10. The cylindrical battery according to claim 6, characterized in that: The ring body portion includes a first ring portion and a second ring portion, the first ring portion is arranged around the outer circumference of the first protrusion, and the second ring portion is arranged around the outer circumference of the first ring portion; along the thickness direction of the end cover, on the side away from the electrode assembly, the surface of the first ring portion and the surface of the second ring portion are coplanar, and on the side facing the electrode assembly, the first ring portion protrudes toward one side of the electrode assembly relative to the second ring portion to form a step surface between the first ring portion and the second ring portion, and the first end face is at least partially embedded in the step surface.

11. The cylindrical battery according to claim 6, characterized in that: The radial inner side of the first end surface includes a positioning notch, and the outer peripheral edge of the ring body is at least partially accommodated in the positioning notch.

12. An electronic device, characterized in that: A cylindrical battery comprising any one of claims 1 to 11.

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