Cylindrical battery and method for manufacturing cylindrical battery

Abstract

The invention provides a cylindrical battery and a manufacturing method of the cylindrical battery, the cylindrical battery comprises a shell, an electrode assembly and an end cover, the shell comprises a side wall with an opening; the electrode assembly is arranged in the shell and is electrically connected with the shell; the end cover covers and seals the opening, and the outer edge of the end cover is in lap joint with the side wall and is welded with the side wall to form a first welding mark; wherein the first welding mark penetrates through the end cover along the arrangement direction of the electrode assembly and the end cover and enters the interior of the side wall. The technical problem that the production efficiency of cylindrical battery manufacturing is low can be solved.

Description

Technical Field

[0001] The present invention relates to the technical field of batteries, and in particular to a cylindrical battery and a method for manufacturing the cylindrical battery. Background Art

[0002] Cylindrical batteries have a high energy density and are therefore widely used in the lithium battery industry. Currently, the main sealing solutions for cylindrical batteries include laser sealing and groove sealing. Laser sealing is the most common method, which involves irradiating the outer shell with a laser along its radial direction during welding, creating a seal on the sidewall of the shell at the opening.

[0003] The adoption of the above-mentioned side laser sealing solution results in the electrode assembly needing to be frequently laid down and stood up during the actual manufacturing process, which can easily cause mechanical damage and wasted movement, thereby reducing the product yield and production efficiency of cylindrical batteries. Summary of the Invention

[0004] The present invention provides a cylindrical battery and a method for manufacturing the cylindrical battery, so as to improve the technical problem of low production efficiency in the manufacture of cylindrical batteries.

[0005] To achieve the above-mentioned objectives and other related objectives, the present invention provides a cylindrical battery in a first aspect, comprising: a shell, an electrode assembly and an end cap, wherein the shell comprises a side wall having an opening; the electrode assembly is disposed in the shell and electrically connected to the shell; the end cap seals the opening, and the outer edge of the end cap overlaps the side wall and is welded to the side wall to form a first weld mark; wherein the first weld mark penetrates the end cap along the arrangement direction of the electrode assembly and the end cap and enters the interior of the side wall.

[0006] In one example of a cylindrical battery of the present invention, the side wall includes a first end face located on the opening side, the end cover includes a cover body portion and a welding portion arranged around the outer periphery of the cover body portion, the welding portion overlaps the first end face and is welded to the first end face to form a first weld mark, and the thickness of the welding portion is less than the thickness of the cover body portion.

[0007] In an example of a cylindrical battery of the present invention, the thickness of the welding portion is A, and 0.2mm≤A≤0.4mm, and along the radial direction of the end cover, the surface width dimension of the welding portion away from the electrode assembly is B, and 0.3mm≤B≤0.5mm.

[0008] In an example of the cylindrical battery of the present invention, along the thickness direction of the end cover, the surface of the cover body facing away from the electrode assembly protrudes from the surface of the welding portion facing away from the electrode assembly, forming a height difference H1, and 0.05mm≤H1≤0.15mm.

[0009] In an example of a cylindrical battery of the present invention, along the thickness direction of the end cover, the cover body extends to the interior of the shell toward the side of the electrode assembly and matches the opening. The dimension of the cover body extending to the interior of the shell is H2, and H2 ≥ 0.2 mm.

[0010] In an example of a cylindrical battery of the present invention, the cylindrical battery further includes a first current collecting member and a pole. The first current collecting member is arranged between the electrode assembly and the end cover and is electrically connected to the electrode assembly. The pole passes through the end cover and is welded to the first current collecting member to form a second weld mark, and the exposed surface of the second weld mark is located in the same direction as the exposed surface of the first weld mark.

[0011] In an example of a cylindrical battery of the present invention, the electrode includes a liquid injection hole, and the cylindrical battery also includes a sealing nail; the sealing nail includes a sealing portion and a nail body portion, the sealing portion is located on the side of the nail body portion facing the electrode assembly, and is at least partially inserted into the liquid injection hole to seal the liquid injection hole; the nail body portion is welded to the electrode to form a third weld mark, and the exposed surface of the third weld mark is located in the same direction as the exposed surface of the first weld mark.

[0012] In one example of a cylindrical battery of the present invention, the side of the side wall away from the opening includes an end wall, and the cylindrical battery also includes a second current collecting member, which is arranged between the electrode assembly and the end wall and electrically connected to the electrode assembly; the end wall includes a recessed portion recessed toward the electrode assembly side, and the recess is welded to the second current collecting member to form a fourth weld mark; the exposed surface of the fourth weld mark is located in the same direction or opposite direction as the exposed surface of the first weld mark.

[0013] In an example of the cylindrical battery of the present invention, the first current collecting member includes a first thickened portion, which is welded to the pole to form a second weld mark; the second current collecting member includes a second thickened portion, which is welded to the recess to form a fourth weld mark.

[0014] The second aspect of the present invention also provides a method for manufacturing a cylindrical battery, which includes: S1: installing the electrode assembly from the opening of the shell into the shell, and the shell includes a side wall; S2: covering the end cover on the opening, and making the outer edge of the end cover overlap the side wall to form an overlapping area; S3: keeping the end cover and the shell in a static state; S4: irradiating the welding laser from the side of the end cover away from the electrode assembly to the overlapping area, and performing penetrating welding on the overlapping area to seal the opening of the end cover.

[0015] In an example of the manufacturing method of the present invention, in steps S1 to S4, the shell always maintains a vertical state with the opening facing the vertical direction.

[0016] In one example of the manufacturing method of the present invention, the cylindrical battery further includes a first current collecting member and a second current collecting member, and a first electrode tab and a second electrode tab are formed at both ends of the electrode assembly, respectively. The manufacturing method further includes: welding the first current collecting member to the first electrode tab; and welding the second current collecting member to the second electrode tab.

[0017] In an example of the manufacturing method of the present invention, the cylindrical battery further includes a pole. Before step S2, the manufacturing method further includes: insulating and fixing the pole to the end cover, and allowing the pole to penetrate the end cover along the thickness direction of the end cover.

[0018] In one example of the manufacturing method of the present invention, the manufacturing method further includes: irradiating a welding laser from the side of the electrode column away from the electrode assembly along the arrangement direction of the electrode assembly and the end cover to weld the electrode column and the first current collecting component and form a second weld mark.

[0019] In one example of the manufacturing method of the present invention, the pole further includes a liquid injection hole, and the cylindrical battery further includes a sealing pin. The manufacturing method further includes: inserting the sealing pin into the liquid injection hole, and making the sealing pin seal the liquid injection hole and the second weld mark; along the arrangement direction of the electrode assembly and the end cover, irradiating the welding laser from the side of the sealing pin away from the electrode assembly to weld the sealing pin to the pole.

[0020] In one example of the manufacturing method of the present invention, the side of the shell away from the opening includes an end wall. After step S1, the manufacturing method further includes: welding the second current collecting component to the end wall on the outside of the shell along the arrangement direction of the electrode assembly and the end cover; or welding the second current collecting component to the end wall on the inside of the shell.

[0021] In one example of the manufacturing method of the present invention, the manufacturing method further includes: irradiating a welding laser from the outside of the shell to the end wall along the arrangement direction of the electrode assembly and the end cover to perform penetration welding on the end wall and the second current collecting member.

[0022] In one example of the manufacturing method of the present invention, the manufacturing method further includes: along the arrangement direction of the electrode assembly and the end cover, the welding head extends from the opening and penetrates the electrode assembly and is pressed against the second current collecting component, so as to perform torque welding on the second current collecting component and the end wall when the welding head is twisted.

[0023] The cylindrical battery provided by the present invention is provided with an end cover at the opening of the shell, the end cover seals the opening, and the outer edge of the end cover overlaps the side wall and is welded to the side wall to form a first weld mark, and the first weld mark penetrates the end cover along the arrangement direction of the electrode assembly and the end cover and enters the interior of the side wall. With this arrangement, when sealing the opening of the shell, the end cover and the side wall can be laser welded along the vertical direction of the shell. Since the welding direction is consistent with the arrangement direction of the electrode assembly and the end cover, that is, consistent with the direction of the electrode assembly entering the shell, when assembling the cylindrical battery, it is only necessary to keep the shell in a vertical state with the opening facing the whole time, so that the electrode assembly can be inserted into the shell, the end cover can seal the opening, and the sealing welding between the end cover and the side wall can be completed in sequence. Therefore, the frequent falling and standing up of the shell during the production and manufacturing process of the cylindrical battery can be reduced, the waste of mechanical action can be reduced, and the production efficiency of the cylindrical battery can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other embodiments can be obtained based on these drawings without paying any creative work.

[0025] Figure 1 A cross-sectional view of the overall structure of an example of a cylindrical battery of the present invention;

[0026] Figure 2 for Figure 1 A partial enlarged view of area A in the middle;

[0027] Figure 3 This is a schematic diagram of the electrode assembly structure of an example of a cylindrical battery of the present invention;

[0028] Figure 4 for Figure 1 A partial enlarged view of the middle B area;

[0029] Figure 5 This is a partial enlarged view of the first weld mark position in an example of a cylindrical battery of the present invention;

[0030] Figure 6 This is a schematic diagram of the installation of the electrode on the end cover in an example of a cylindrical battery of the present invention;

[0031] Figure 7 for Figure 6 A partial enlarged view of the middle D area;

[0032] Figure 8 This is a schematic diagram of the cross-sectional structure of a shell in an example of a cylindrical battery of the present invention;

[0033] Figure 9 for Figure 8 A partial enlarged view of the middle C area;

[0034] Figure 10 This is a schematic structural diagram of a cylindrical battery in which current collecting components are welded to both ends of an electrode assembly in an example of the present invention;

[0035] Figure 11 This is a cross-sectional schematic diagram of a sealing nail in an example of a cylindrical battery of the present invention;

[0036] Figure 12 A schematic diagram of an example of a cylindrical battery according to the present invention when a welding head is inserted into the interior of the shell for welding;

[0037] Figure 13 FIG. 1 is a flow chart of a method for manufacturing a cylindrical battery according to an embodiment of the present invention.

[0038] Component number description

[0039] 100, cylindrical battery; 110, housing; 111, side wall; 1111, first end face; 112, opening; 113, end wall; 1131, second recess; 114, overlap area; 120, electrode assembly; 121, positive electrode sheet; 1211, positive electrode current collector; 1212, first coated area; 1213, first uncoated area; 122, separator; 123, negative electrode sheet; 1231, negative electrode current collector; 1232, second coated area; 1233, second uncoated area; 124, second tab; 125, first tab; 126, winding core through hole; 130, end cap; 131, cover body; 132, welding part; 133, accommodating groove; 134, mounting hole; 135, insulating member; 140, first weld mark; 151, first current collecting component; 1511, opening; 1512, first main body; 1513, first thickened portion; 152, second current collecting component; 1521, fourth weld mark; 1522, second main body; 1523, second thickened portion; 160, pole; 161, thinning area; 162, injection hole; 163, second weld mark; 164, sink; 165, third weld mark; 166, first recess; 170, sealing nail; 171, nail body; 172, sealing portion; 180, channel; 190, welding head. DETAILED DESCRIPTION

[0040] The following describes the embodiments of the present invention through specific examples. 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 embodiments, and the details in this specification can also be modified or changed based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the following examples and the features in the examples can be combined with each other unless they conflict. It should also be understood that the terms used in the examples of the present invention are for the purpose of describing specific embodiments, not for the purpose of limiting the scope of protection of the present invention. The test methods for which specific conditions are not specified in the following examples are generally carried out under conventional conditions or under the conditions recommended by the manufacturers.

[0041] When numerical ranges are given in the examples, it should be understood that unless otherwise specified herein, both endpoints of each numerical range and any value between the two endpoints may be used. Unless otherwise defined, all technical and scientific terms used herein are consistent with the prior art as understood by those skilled in the art and the description of the present invention. Any prior art methods, devices, and materials similar or equivalent to those described in the examples of the present invention may also be used to implement the present invention.

[0042] 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 invention. Changes or adjustments to their relative relationships should be regarded as the scope of implementation of the present invention without substantially changing the technical content.

[0043] See also Figures 1 to 13 The present invention provides a cylindrical battery 100 and a method for manufacturing the cylindrical battery 100. In the cylindrical battery 100, at the opening 112 of the shell 110, the end cap 130 and the side wall 111 are welded to form a first weld mark 140, and the first weld mark 140 penetrates the end cap 130 along the arrangement direction of the electrode assembly 120 and the end cap 130 and enters the interior of the side wall 111. In this arrangement, when the opening 112 of the shell 110 is sealed, the end cap 130 and the side wall 111 can be laser welded along the vertical direction of the shell 110. Therefore, the frequent laying down and standing up of the shell 110 during the production process of the cylindrical battery 100 can be reduced, the waste of mechanical movements is reduced, and the production efficiency of the cylindrical battery 100 is improved.

[0044] See also Figures 1 to 12 The present invention provides a cylindrical battery 100 , which includes a shell 110 , an electrode assembly 120 and an end cover 130 .

[0045] See also Figure 1 The shell 110 includes an end wall 113 and a side wall 111 surrounding the end wall 113. As long as a stable sealing and electrical connection relationship can be formed, the connection between the end wall 113 and the side wall 111 can be achieved in a variety of ways, such as integral stamping, integral casting, or split welding. The side wall 111 is cylindrical and surrounds the outer edge of the end wall 113, and a circular opening 112 is formed at the end of the side wall 111 away from the end wall 113. A accommodating cavity is formed in the shell 110 surrounded by the end wall 113 and the side wall 111, which is used to accommodate the electrode assembly 120, electrolyte and other necessary components of the cylindrical battery 100. Specifically, the diameter of the shell 110 can be determined according to the specific size of the electrode assembly 120, such as 18mm, 21mm, 46mm, etc. The shell 110 can be made of various materials, 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 can be plated on the surface of the shell 110.

[0046] See also Figures 1 to 3The electrode assembly 120 is disposed inside the housing 110. The electrode assembly 120 is the component where the electrochemical reaction occurs in the cylindrical battery 100. The housing 110 may contain one or more electrode assemblies 120. The electrode assembly 120 includes a pole piece and a separator 122, which are wound to form a wound structure. Specifically, in this embodiment, the electrode assembly 120 includes a positive pole piece 121, a separator 122, and a negative pole piece 123 axially wound around the housing 110.

[0047] See also Figure 3 The positive electrode sheet 121 includes a positive electrode current collector 1211 and a positive electrode active material layer coated on the positive electrode current collector 1211. A first coating area 1212 coated with the positive electrode active material layer and a first uncoated area 1213 not coated with the positive electrode active material layer are formed on the positive electrode current collector 1211. The first coating area 1212 and the first uncoated area 1213 are arranged axially along the shell 110. The first uncoated area 1213 extends to the outside of the diaphragm 122 toward one end in the height direction of the cylindrical battery 100, and is bent toward the axis of the shell 110 to form a stacked positive electrode tab.

[0048] Please continue reading Figure 3 The negative electrode sheet 123 includes a negative electrode current collector 1231 and a negative electrode active material layer coated on the negative electrode current collector 1231. A second coating area 1232 coated with the negative electrode active material layer and a second uncoated area 1233 not coated with the negative electrode active material layer are formed on the negative electrode current collector 1231. The second coating area 1232 and the second uncoated area 1233 are arranged axially along the shell 110. The second uncoated area 1233 extends to the outside of the diaphragm 122 toward the other end in the height direction of the cylindrical battery 100, and is bent toward the axis of the shell 110 to form a stacked negative electrode tab.

[0049] Please continue reading Figure 3The separator 122 is disposed between the positive electrode sheet 121 and the negative electrode sheet 123 to separate the positive electrode active material layer from the negative electrode active material layer. Taking the lithium-ion cylindrical battery 100 as an example, the material of the positive electrode current collector 1211 can be aluminum, and the positive electrode active material layer includes a 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 1231 can be copper, and the negative electrode active material layer includes a negative electrode active material, which can be carbon or silicon. The base material of the separator 122 can be polypropylene (PP) or polyethylene (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, polyethylene terephthalate (PET), polyvinyl chloride (PVC), or other high molecular polymer materials.

[0050] Please continue reading Figure 1 、 Figure 2 and Figure 4 In an example of a cylindrical battery 100 according to the present invention, an electrode assembly 120 is sealed and mounted within a housing 110. The electrode assembly 120 is provided with a first tab 125 and a second tab 124 at either end of the cylindrical battery 100 in the height direction. The first tab 125 and the second tab 124 have opposite polarities, with the first tab 125 facing the opening 112. The first tab 125 is the positive tab, while the second tab 124 is the negative tab. It should be noted that in other embodiments, the first tab 125 may be the negative tab, while the second tab 124 may be the positive tab. The electrical connection between the electrode assembly 120 and the shell 110 means that the first pole ear 125 or the second pole ear 124 of the electrode assembly 120 is electrically connected to the shell 110. There can be various ways of electrical connection. The first pole ear 125 or the second pole ear 124 can be directly electrically connected to the end wall 113 of the shell 110, or can be electrically connected to the end wall 113 of the shell 110 through a current collecting component, etc. The specific electrical connection method shall be based on meeting the conductivity requirements of the cylindrical battery 100.

[0051] See also Figure 2 and Figure 5The end face of the side wall 111 on the side of the opening 112 is the first end face 1111. The end cap 130 covers the opening 112. The outer edge of the end cap 130 overlaps the first end face 1111 and forms an overlap region 114 around the outer periphery of the opening 112. The end cap 130 and the side wall 111 are sealed and welded in the overlap region 114 to form a first weld mark 140. The first weld mark 140 penetrates the end cap 130 and the first end face 1111 along the arrangement direction of the electrode assembly 120 and the end cap 130 (i.e., the axial direction of the shell 110) and enters the interior of the side wall 111. Figure 5 As shown, the exposed surface of the first weld mark 140 is located on the side of the end cap 130 facing away from the electrode assembly 120 . With this arrangement, during the manufacturing process of the cylindrical battery 100, when the end cap 130 is covered on the opening 112 and it is necessary to seal-weld the end cap 130 and the side wall 111, the end cap 130 and the side wall 111 can be laser-welded along the vertical direction of the shell 110. Since this welding direction is consistent with the arrangement direction of the electrode assembly 120 and the end cap 130, that is, consistent with the direction in which the electrode assembly 120 is inserted into the shell and the direction in which the end cap 130 is covered on the shell 110, during the manufacturing process of the cylindrical battery 100, it is only necessary to keep the shell 110 in a vertical state with the opening 112 facing the shell, so that multiple processes such as inserting the electrode assembly 120 into the shell, covering the opening 112 with the end cap 130, and sealing welding between the end cap 130 and the side wall 111 can be completed in sequence. Therefore, the frequent laying down and standing up of the shell 110 during the manufacturing process of the cylindrical battery 100 can be reduced, thereby reducing the waste of mechanical movements during the manufacturing process of the cylindrical battery 100, thereby improving the production efficiency of the cylindrical battery 100. At the same time, the probability of collision, damage and mutual displacement between various parts inside the cylindrical battery 100 caused by frequent changes in the shell 110 can also be reduced, thereby improving the product yield of the cylindrical battery 100.

[0052] See also Figure 2 and Figure 5In one example of a cylindrical battery 100 according to the present invention, the end cap 130 includes a cover portion 131 and a welding portion 132. The welding portion 132 is disposed around the outer periphery of the cover portion 131. The welding portion 132 overlaps the first end surface 1111 and is welded thereto to form the aforementioned first weld mark 140. The thickness of the welding portion 132 is less than the thickness of the cover portion 131. Along the thickness direction of the end cap 130, the welding portion 132 can form a height difference with the cover portion 131 at the top (i.e., the side facing away from the electrode assembly 120); it can also form a height difference with the cover portion 131 at the bottom (i.e., the side facing the electrode assembly 120); or it can form a height difference with the cover portion 131 at both the top and bottom of the end cap 130 thickness direction. In this embodiment, the height difference between the welding portion 132 and the cover portion 131 is not limited in direction, as long as the thickness of the welding portion 132 is less than the required thickness of the cover portion 131. By making the thickness of the welding portion 132 thinner than the thickness of the cover portion 131, the laser can more easily penetrate the welding portion 132 during laser welding between the welding portion 132 and the side wall 111, thereby reducing welding power consumption and achieving energy conservation and emission reduction. Furthermore, the welding process at this location can be improved, thereby increasing the welding efficiency of the first weld mark 140.

[0053] See also Figure 5 and Figure 7 In one example of a cylindrical battery 100 according to the present invention, along the thickness direction of the end cap 130, the surface of the cover portion 131 facing away from the electrode assembly 120 protrudes above the surface of the welding portion 132 facing away from the electrode assembly 120, forming a height difference H1, where 0.05 mm ≤ H1 ≤ 0.15 mm. For example, H1 can be 0.05 mm, 0.10 mm, or 0.15 mm. This arrangement allows for a receiving groove 133 to be formed between the cover portion 131 and the welding portion 132 on the side facing away from the electrode assembly 120. When the welding portion 132 is welded to the lower sidewall 111, the receiving groove 133 can accommodate the first weld mark 140, reducing the probability of the first weld mark 140 protruding from the outer surface of the cover portion 131. This facilitates the installation and connection between the external connector and the outer surface of the cover portion 131. Setting the height difference H1 between 0.05 and 0.15 mm satisfies the height requirement of avoiding most weld marks during welding of the end cap 130. At the same time, the provision of the receiving groove 133 can also reduce the probability of welding slag splashing onto the outer surface of the cover body 131 during the welding process, thereby reducing the workload of cleaning the welding slag in the later stage.

[0054] In one example of a cylindrical battery 100 according to the present invention, the thickness of the weld portion 132 is A, and 0.2 mm ≤ A ≤ 0.4 mm. For example, A can be 0.2 mm, 0.3 mm, or 0.4 mm. On the side of the end cap 130 facing away from the electrode assembly 120, a height difference H1 is formed between the cover portion 131 and the weld portion 132. Along the radial direction of the end cap 130, the surface width dimension of the weld portion 132 is B, and 0.3 mm ≤ B ≤ 0.5 mm. For example, width dimension B can be 0.3 mm, 0.4 mm, or 0.5 mm. Setting the thickness dimension A of the weld portion 132 between 0.2 and 0.4 mm ensures that the thickness of the weld portion 132 meets both the thickness requirements for laser penetration welding and the weld strength requirements between the weld portion 132 and the sidewall 111. At the same time, the width dimension B of the welding portion 132 is set between 0.3 and 0.5 mm, so that the width dimension of the welding portion 132 can match the thickness dimension of the conventional side wall 111 in the radial direction, reducing the probability of forming a cold weld or a leaky weld between the welding portion 132 and the side wall 111 during welding, which is conducive to better ensuring the welding quality.

[0055] Further, in order to facilitate the positioning and installation of the end cap 130 at the opening 112, please refer to Figure 5 and Figure 7 In an example of the cylindrical battery 100 of the present invention, along the thickness direction of the end cap 130, the cover body 131 extends toward one side of the electrode assembly 120 to the interior of the shell 110 and matches the opening 112. When the end cap 130 is covered on the opening 112, the displacement of the end cap 130 relative to the shell 110 in the radial direction of the shell 110 is limited, thereby improving the installation and positioning accuracy of the end cap 130 at the opening 112. The dimension of the cover body 131 extending to the interior of the shell 110 is H2, and H2 ≥ 0.2 mm. For example, H2 can be 0.2 mm, 0.5 mm, 1.0 mm, etc. This arrangement ensures that the dimension H2 can meet the installation and positioning requirements of the end cap 130 in the opening 112 without excessively increasing the mass of the end cap 130, thereby facilitating the lightweight design of the cylindrical battery 100.

[0056] In order to facilitate the electrical connection between the electrode assembly 120 and the outside of the shell 110, the cylindrical battery 100 is usually provided with a pole 160 and a current collecting member at the end of the shell 110. The pole 160 can be provided on the side of the end wall 113 of the shell 110, or on the side of the opening 112 of the shell 110, that is, on the end cover 130. The pole 160 can be directly electrically connected to the tab of the electrode assembly 120, or it can be electrically connected to the tab of the electrode assembly 120 through the current collecting member. Optionally, in an example of the cylindrical battery 100 of the present invention, please refer to Figure 2The cylindrical battery 100 also includes a first current collecting member 151 and an electrode post 160. The first current collecting member 151 is disposed between the electrode assembly 120 and the end cap 130. The first current collecting member 151 is electrically connected to the first tab 125 of the electrode assembly 120 to achieve electrical connection with the electrode assembly 120. This electrical connection can be achieved through various methods, such as welding or conductive adhesive bonding. The end cap 130 defines a mounting hole 134, extending in the same direction as the thickness of the end cap 130. The electrode post 160 is secured within the mounting hole 134 via an insulating member 135, thereby achieving insulated and secure mounting of the electrode post 160 on the end cap 130. One end of the electrode post 160 is exposed outside the end cap 130, while the other end extends into the interior of the housing 110 and is welded to the first current collecting member 151, forming a second weld mark 163. The size and specific location of the second weld mark 163 are not limited, and are subject to the flow conduction requirements between the electrode 160 and the electrode assembly 120. Preferably, in this embodiment, the second weld mark 163 is arranged around the axis of the electrode 160, which can facilitate the welding positioning between the electrode 160 and the first current collecting member 151 and improve the welding efficiency. The exposed surface of the second weld mark 163 formed on the electrode 160 is located on the side of the electrode 160 away from the electrode assembly 120, such as Figure 2 That is, along the arrangement direction of the end cap 130 and the electrode assembly 120 , the exposed surface of the second weld mark 163 and the exposed surface of the first weld mark 140 are located in the same direction.

[0057] In this embodiment, since the exposed surface of the second weld mark 163 and the exposed surface of the first weld mark 140 are located in the same direction, during the manufacturing process of the cylindrical battery 100, when the first weld mark 140 and the second weld mark 163 are welded, the shell 110 can be kept in the same placement state, that is, the shell 110 always maintains a vertical state with the opening 112 facing upward. Therefore, the frequency of the shell 110 being laid down and stood up during the manufacturing process of the cylindrical battery 100 can be further reduced, thereby further improving the production efficiency of the cylindrical battery 100.

[0058] Furthermore, in order to facilitate welding between the pole 160 and the first current collecting member 151, in one embodiment of the present invention, please refer to Figure 2 and Figure 6A first recess 166 is provided on the side of the electrode post 160 facing away from the electrode assembly 120. The first recess 166 is recessed toward the side of the electrode assembly 120. The bottom wall of the first recess 166 forms a thinned region 161. The thinned region 161 abuts and welds with the first current collecting member 151 below, forming a second weld mark 163. The exposed surface of the second weld mark 163 is located on the surface of the thinned region 161 facing away from the electrode assembly 120. The specific shape of the first recess 166 can be various, such as a rectangular parallelepiped, a cylindrical shape, or a polygonal shape. To facilitate the positioning and processing of the first recess 166 on the electrode post 160, preferably, in this embodiment, the first recess 166 is a substantially cylindrical structure and is coaxially arranged with the electrode post 160. In this embodiment, a thinned area 161 is provided on the pole 160 so that the thinned area 161 is welded to the first current collecting member 151. This improves the welding process between the pole 160 and the first current collecting member 151 and improves the welding quality. It also reduces the power consumption of the welding laser when penetrating the pole 160, thereby achieving energy conservation and emission reduction.

[0059] In order to further improve the welding quality between the first current collecting member 151 and the thinned area 161 and reduce the probability of the first current collecting member 151 being welded through, in one embodiment of the present invention, please refer to Figure 2 The first current collecting member 151 includes a first main portion 1512 and a first thickened portion 1513, which are fixedly connected to each other. The first main portion 1512 is disposed around the outer periphery of the first thickened portion 1513. The first thickened portion 1513 protrudes relative to the first main portion 1512 toward the thinned region 161 and abuts and welds with the thinned region 161, forming a second weld mark 163. The provision of the first thickened portion 1513 locally increases the thickness of the first current collecting member 151 in the area abutting the thinned region 161, thereby reducing the probability of weld penetration of the first current collecting member 151 during welding of the thinned region 161 to the first current collecting member 151, thereby further improving the weld quality between the first current collecting member 151 and the thinned region 161.

[0060] Considering the injection requirements of the cylindrical battery 100, an injection hole 162 is usually provided on the cylindrical battery 100. There are many options for the location of the injection hole 162. For example, the injection hole 162 can be provided on the end wall 113 of the shell 110, on the end cover 130, or on the terminal 160. Figure 2 and Figure 6The terminal 160 includes an injection hole 162. The injection hole 162 can be a variety of shapes, such as a circular hole or a square hole. The injection hole 162 can be coaxial with the terminal 160 or non-coaxially, depending on the injection position requirements. Preferably, in this embodiment, the injection hole 162 is located at the center of the terminal 160, that is, the injection hole 162 passes through the thinned area 161 on the terminal 160, and the injection hole 162 is a circular hole structure coaxial with the terminal 160.

[0061] See also Figure 2 and Figure 11 The cylindrical battery 100 also includes a sealing nail 170 for sealing the liquid injection hole 162. The sealing nail 170 includes a sealing portion 172 and a nail body 171 that are fixedly connected. The sealing portion 172 and the nail body 171 can be integrally formed, adhesively fixed, or hot-melt fixed. In the actual production process, the fixing method between the sealing portion 172 and the nail body 171 is related to the material of the sealing portion 172 and the nail body 171. The sealing portion 172 is located on the side of the nail body 171 facing the electrode assembly 120, and is at least partially inserted downward into the liquid injection hole 162 to block the liquid injection hole 162. In order to ensure the sealing performance of the liquid injection hole 162, preferably, in this embodiment, the sealing portion 172 is made of rubber material. Preferably, in this embodiment, the sealing portion 172 is specifically made of fluororubber material. The nail body 171 is made of metal, such as aluminum, copper, etc. Specifically, in this embodiment, the material of the nail body 171 is aluminum. In this embodiment, the nail body 171 and the sealing portion 172 are correspondingly formed by hot melt. The side wall of the first recess 166 is processed with a sink 164 on the side away from the thinning area 161, and the side of the nail body 171 away from the sealing portion 172 is connected to the sink 164, and a butt joint is formed on the side of the pole 160 away from the electrode assembly 120. The laser irradiates the butt joint and forms a third weld mark 165 at the position of the butt joint to achieve welding between the nail body 171 and the pole 160, and then presses the sealing portion 172 into the inside of the injection hole 162 to achieve sealing of the injection hole 162, and the exposed surface of the third weld mark 165 is located in the same direction as the exposed surface of the first weld mark 140, that is, both are located on the side of the end cap 130 away from the electrode assembly 120. With this arrangement, during the manufacturing process of the cylindrical battery 100, when the third weld mark 165 is welded, the shell 110 also needs to maintain a vertical state with the opening 112 facing upward. Therefore, after the welding of the first weld mark 140 and the second weld mark 163 is completed, the third weld mark 165 can be directly welded without changing the placement state of the shell 110, thereby further improving the production efficiency of the cylindrical battery 100.

[0062] See also Figure 1 and Figure 4In an example of the cylindrical battery 100 of the present invention, the cylindrical battery 100 further includes a second current collecting member 152. The second current collecting member 152 is disposed between the electrode assembly 120 and the end wall 113. The second current collecting member 152 is welded to the second tab 124 of the electrode assembly 120 to achieve electrical connection between the second current collecting member 152 and the electrode assembly 120. The end wall 113 includes a second recessed portion 1131 that is recessed toward the electrode assembly 120. The second recessed portion 1131 is welded to the second current collecting member 152 to form a fourth weld mark 1521. The location of the second recessed portion 1131 on the end wall 113 is not limited. It can be disposed in the central area of ​​the end wall 113 or in an area eccentric to the center of the end wall 113. The shape of the second recessed portion 1131 is also not limited. It can be a cylindrical, rectangular, or polygonal shape. Preferably, in this embodiment, please refer to Figure 8 and Figure 9 The second recess 1131 is approximately cylindrical and coaxial with the end wall 113. This arrangement facilitates stamping the second recess 1131 on the end wall 113. The fourth weld mark 1521, formed by welding the second recess 1131 to the second current collecting member 152, is also formed in the center of the end wall 113.

[0063] There are many ways to form the fourth weld mark 1521. In this embodiment, Figure 4 and Figure 12 As shown, the first current collecting member 151 is provided with an opening 1511. The electrode assembly 120 has a winding core through-hole 126. The opening 1511 is arranged corresponding to the winding core through-hole 126, and a channel 180 is formed for the welding head 190 to enter. The second current collecting member 152 at least partially blocks the winding core through-hole 126. The welding head 190 extends into the channel 180 from the side of the opening 112, penetrates the electrode assembly 120 in the vertical direction of the housing 110, and then presses the second current collecting member 152 below. This presses the second current collecting member 152 downward, causing a portion of the second current collecting member 152 to press against the second recess 1131 of the end wall 113. The welding head 190 is then twisted to achieve a torque weld between the second current collecting member 152 and the end wall 113. The exposed surface of the fourth weld mark 1521 generated in this manner is located on the surface of the second current collecting member 152 facing away from the end wall 113 , ie, in the same direction as the exposed surface of the first weld mark 140 .

[0064] In another embodiment, a laser welding laser may be used to perform laser penetration welding on the second recess 1131 and the second current collecting member 152 from the outside of the end wall 113 (i.e., the bottom of the housing 110), thereby forming a fourth weld mark 1521. The exposed surface of the fourth weld mark 1521 formed in this manner is located on the side of the end wall 113 facing away from the electrode assembly 120, i.e., in the opposite direction to the exposed surface of the first weld mark 140.

[0065] In the above embodiment, by making the exposed surface of the fourth weld mark 1521 and the exposed surface of the first weld mark 140 located in the same direction or in the opposite direction, in this way, during the manufacturing process of the cylindrical battery 100, when the fourth weld mark 1521 is welded, the shell 110 only needs to maintain a vertical state with the opening 112 facing upward, and this state is exactly the placement state of the shell 110 when the first weld mark 140 is welded and after the welding is completed. Therefore, when welding the first weld mark 140 and the fourth weld mark 1521, the placement state of the shell 110 does not need to be changed, so the shell 110 does not need to be inverted or upright during this process, which can further improve the production efficiency of the cylindrical battery 100.

[0066] When the exposed surface of the fourth weld mark 1521 is located on the side of the end wall 113 away from the electrode assembly 120, that is, in the opposite direction to the exposed surface of the first weld mark 140, in order to improve the welding quality between the end wall 113 and the second current collecting member 152 and reduce the probability of the second current collecting member 152 being welded through, preferably, refer to Figure 4 、 Figure 8 and Figure 9 In one embodiment of the present invention, the second current collecting member 152 includes a second main portion 1522 and a second thickened portion 1523 fixedly connected to each other. The second main portion 1522 is disposed around the outer periphery of the second thickened portion 1523. The second thickened portion 1523 protrudes relative to the second main portion 1522 toward the end wall 113 and abuts and welds with the second recessed portion 1131 on the end wall 113, forming a fourth weld mark 1521. The provision of the second thickened portion 1523 locally increases the thickness of the second current collecting member 152 in the area abutting the second recessed portion 1131. This reduces the probability of weld penetration of the second current collecting member 152 during laser welding of the end wall 113 and the second current collecting member 152 from the outside of the end wall 113, thereby improving the weld quality between the second current collecting member 152 and the end wall 113.

[0067] The second aspect of the present application also provides a method for manufacturing a cylindrical battery 100, see Figure 13 The manufacturing method of the cylindrical battery 100 includes the following steps:

[0068] S1: Install the electrode assembly 120 into the housing 110 through the opening 112 of the housing 110. The housing 110 includes a side wall 111. In this step, optionally, in this embodiment, refer to Figure 12, is to install the electrode assembly 120 into the interior of the shell 110 while the shell 110 is in a vertical state with the opening 112 facing in the direction. This can reduce the probability of scratches between the electrode assembly 120 and the side wall 111 of the shell 110 during the process of being inserted into the shell. In other embodiments, the electrode assembly 120 can also be installed into the interior of the shell 110 when the shell 110 is laid down, that is, when the shell 110 is laid flat. It should be noted that the specific steps of installing the electrode assembly 120 into the interior of the shell 110 in this step can refer to the steps of installing the electrode assembly 120 into the shell 110 in the prior art, and will not be repeated here.

[0069] S2: Cover the end cap 130 on the opening 112, and make the outer edge of the end cap 130 overlap the side wall 111 to form an overlap area 114. In this step, in this embodiment, please refer to Figure 2 and Figure 5 , is to cover the opening 112 from top to bottom with the housing 110 in a vertical state with the opening 112 facing in the direction. In other embodiments, the end cap 130 may be covered with the opening 112 when the housing 110 is in an inverted state, that is, when the housing 110 is laid flat.

[0070] S3: Keep the end cap 130 and the housing 110 in a stationary state. Figure 1 and Figure 2 In this step, the housing 110 is first kept stationary, that is, the housing 110 is fixed to the assembly station by the positioning structure, and the housing 110 is kept stationary. Then, the end cap 130 is pressed against the housing 110 by the pressing device to achieve the stationary state of the end cap 130 relative to the housing 110, thereby achieving the stationary state of both the end cap 130 and the housing 110. It should be noted that the positioning structure and the pressing device are conventional structures set in the manufacturing process of cylindrical batteries 100, which are well known to those skilled in the art and will not be described in detail here.

[0071] S4: Irradiate the welding laser from the side of the end cap 130 away from the electrode assembly 120 to the overlapping area 114, and perform penetration welding on the overlapping area 114 so that the end cap 130 seals the opening 112. In this step, please refer to Figure 2 and Figure 5, while the end cap 130 and the shell 110 remain stationary, the welding laser is irradiated from the side of the end cap 130 away from the electrode assembly 120 to the overlapping area 114, and the welding laser rotates along the circumferential direction of the shell 110, thereby completing the circumferential welding of the entire overlapping area 114, thereby achieving the sealing of the end cap 130 to the opening 112. In this step, the shell 110 can be in a flat state, and the welding laser is irradiated from the side of the end cap 130 away from the electrode assembly 120 to the overlapping area 114, and the overlapping area 114 is welded. Alternatively, the shell 110 can be in a vertical state with the opening 112 facing upward, and the welding laser is irradiated from the side of the end cap 130 away from the electrode assembly 120 to the overlapping area 114, and the overlapping area 114 is welded.

[0072] Using this manufacturing method, when welding end cap 130 to housing 110, both housing 110 and end cap 130 remain stationary. The welding laser only needs to rotate to seal end cap 130 at opening 112 of housing 110. Compared to a welding method in which housing 110 rotates while the welding laser remains stationary, this method improves welding efficiency of end cap 130 at opening 112 and eliminates the need for a rotating drive mechanism for housing 110, thereby reducing procurement costs for the production line.

[0073] In order to further improve the manufacturing efficiency of the cylindrical battery 100, in an example of the manufacturing method of the present invention, in steps S1 to S4, the housing 110 always maintains a vertical state with the opening 112 facing upward, such as Figure 1 and Figure 8As shown. In step S1, while the shell 110 is in a vertical position with the opening 112 facing upward, the electrode assembly 120 is installed into the shell 110 through the opening 112 of the shell 110; in step S2, while the shell 110 is in a vertical position with the opening 112 facing upward, the end cap 130 is covered on the opening 112, and the outer edge of the end cap 130 overlaps the side wall 111 to form an overlapping area 114; in step S3, while the shell 110 is in a vertical position with the opening 112 facing upward, the end cap 130 and the shell 110 are kept in a static state; in step S4, while the shell 110 is in a vertical position with the opening 112 facing upward, a welding laser is irradiated from the side of the end cap 130 facing away from the electrode assembly 120 to the overlapping area 114, and the overlapping area 114 is penetrated and welded, so that the end cap 130 seals the opening 112. With this arrangement, during the execution of steps S1 to S4, since the housing 110 always maintains a vertical position with the opening 112 facing the housing 110, there is no need to change the placement of the housing 110. Therefore, the housing 110 does not need to perform mechanical actions such as laying down or standing up. This can reduce the auxiliary time for positioning the housing 110 between multiple welding processes, thereby improving the manufacturing efficiency of the cylindrical battery 100. At the same time, the positioning accuracy of the housing 110 can be maintained during the transition between various manufacturing steps, which is conducive to improving the stability of the manufacturing accuracy of the cylindrical battery 100.

[0074] In an example of the manufacturing method of the present invention, the cylindrical battery 100 further includes a first current collecting member 151 and a second current collecting member 152, and a first tab 125 and a second tab 124 are formed at both ends of the electrode assembly 120, respectively. Figure 10 As shown, the manufacturing method of the cylindrical battery 100 further includes the following steps:

[0075] The first current collecting member 151 is welded to the first electrode tab 125. In this step, the first electrode tab 125 can be a negative electrode tab or a positive electrode tab. After the electrode assembly 120 is placed in the shell, the first current collecting member 151 can be arranged toward the end wall 113 of the shell 110 or toward the opening 112 of the shell 110. Optionally, in this embodiment, as shown in FIG. Figure 2 As shown, the first tab 125 is the positive electrode tab, and the first current collecting member 151 is disposed toward the opening 112 of the housing 110. The first tab 125 and the first current collecting member 151 can be welded before or after the electrode assembly 120 is placed in the housing. Preferably, in this embodiment, the first tab 125 and the first current collecting member 151 are pre-welded before the electrode assembly 120 is placed in the housing. This reduces the assembly time occupied by the electrode assembly 120 at the housing insertion station, thereby further improving the production efficiency of the cylindrical battery 100.

[0076] The second current collecting member 152 is welded to the second electrode tab 124. In this step, the second electrode tab 124 is the negative electrode tab. After the electrode assembly 120 is placed in the shell, the second current collecting member 152 is placed toward the end wall 113 of the shell 110, as shown in FIG. Figure 1 and Figure 4 The second electrode tab 124 and the second current collecting member 152 are welded before the electrode assembly 120 is placed in the shell, and then when the electrode assembly 120 is placed in the shell, the second current collecting member 152 can be installed in the interior of the shell 110 at the same time.

[0077] In this embodiment, by welding the first and second current collecting members 151 and 152 to the ends of the electrode assembly 120, the electrical connection between the electrode assembly 120 and other components is more secure and reliable, reducing the risk of cold solder joints or loose connections. Furthermore, the provision of the current collecting members can reduce the internal resistance and heat generation of the cylindrical battery 100, thereby improving the overall charge and discharge performance and safety of the cylindrical battery 100.

[0078] In one example of the manufacturing method of the present invention, please refer to Figure 2 The cylindrical battery 100 also includes a terminal 160. Before step S2, the manufacturing method of the cylindrical battery 100 further includes: insulating and fixing the terminal 160 to the end cover 130, and allowing the terminal 160 to penetrate the end cover 130 along the thickness direction of the end cover 130. In this step, there are many ways to fix the terminal 160 to the end cover 130, for example, it can be riveted to the end cover 130, or it can be fixed to the end cover 130 by screwing an insulating sleeve, etc. In this embodiment, there is no specific limitation on this. It can be understood that the insulated fixation of the terminal 160 to the end cover 130 is a conventional setting in the cylindrical battery 100, and will not be repeated in this embodiment. Before step S2, the pole 160 is insulated and installed on the end cover 130. In this way, before the end cover 130 covers the opening 112, the pole 160 can be assembled on the end cover 130 in advance at other stations, thereby reducing the assembly time occupied by the end cover 130 welding station and further improving the production efficiency of the cylindrical battery 100.

[0079] In one example of the manufacturing method of the present invention, please refer to Figure 2The manufacturing method of the cylindrical battery 100 further includes: irradiating a welding laser from the side of the electrode column 160 facing away from the electrode assembly 120 along the arrangement direction of the electrode assembly 120 and the end cap 130, i.e., the vertical direction of the housing 110, so that the welding laser penetrates the electrode column 160 and welds to the first current collecting member 151 below, forming a second weld mark 163. The second weld mark 163 can be welded after the first weld mark 140, before the first weld mark 140, or simultaneously with the first weld mark 140. The second weld mark 163 and the first weld mark 140 can be welded at the same welding station or at two separate welding stations. In actual production, the welding process should be based on meeting the production schedule of the cylindrical battery 100.

[0080] In this embodiment, the electrode 160 is welded to the first current collecting member 151 by irradiating a welding laser from the side of the electrode 160 facing away from the electrode assembly 120. This arrangement allows the shell 110 to be in the same state as when the first weld mark 140 is welded when the second weld mark 163 is performed, that is, the shell 110 is welded in a vertical state with the opening 112 facing upward, thereby eliminating the need for the shell 110 to perform a series of actions such as falling down or standing upside down. Therefore, the positioning preparation time of the shell 110 before the first weld mark 140 or the second weld mark 163 can be shortened, thereby improving the production efficiency of the cylindrical battery 100.

[0081] Considering that the cylindrical battery 100 needs to undergo injection, formation and other processes during the manufacturing process, in an example of the manufacturing method of the present invention, please refer to Figure 2 Hehe Figure 6 , the pole 160 also includes an injection hole 162, and the electrolyte enters the interior of the electrode assembly 120 from the injection hole 162. Specifically, in this embodiment, a first recess 166 is provided on the side of the pole 160 facing away from the electrode assembly 120, and the bottom wall of the first recess 166 forms a thinning area 161, which abuts against the first current collecting member 151 below and is welded to form a second weld mark 163. The exposed surface of the second weld mark 163 is located on the bottom wall of the first recess 166. The injection hole 162 passes through the thinning area 161 on the pole 160, and the injection hole 162 is coaxially arranged with the pole 160. The cylindrical battery 100 also includes a sealing nail 170 for sealing the injection hole 162 after the injection is completed. The manufacturing method of the cylindrical battery 100 also includes the following steps:

[0082] Insert the sealing pin 170 into the liquid injection hole 162, and make the sealing pin 170 seal the liquid injection hole 162 and the second weld mark 163. In this step, please refer to Figure 2 and Figure 11The sealing nail 170 includes a sealing portion 172 and a nail body 171 that are fixedly connected. The sealing portion 172 is located on the side of the nail body 171 facing the electrode assembly 120, and is at least partially inserted downward into the injection hole 162 to seal the injection hole 162, and the sealing portion 172 is made of rubber. A sink 164 is provided on the side of the first recess 166 away from the thinning area 161. The side of the nail body 171 away from the sealing portion 172 cooperates with the sink 164 and forms a joint with the pole 160, and the joint is located on the side of the pole 160 away from the electrode assembly 120. The nail body 171 simultaneously covers the second weld mark 163 and the injection hole 162 below. The nail body 171 is made of metal, such as aluminum, copper, etc. The nail body 171 and the sealing portion 172 are connected as one piece by hot melt.

[0083] Along the arrangement direction of the electrode assembly 120 and the end cap 130, the welding laser is irradiated from the side of the sealing pin 170 away from the electrode assembly 120 to weld the sealing pin 170 and the terminal column 160. In this step, please refer to Figure 2 , from the side of the sealing nail 170 away from the electrode assembly 120 , the joint position in the above step is irradiated to form a third weld mark 165 at the joint to achieve a sealed weld between the nail body 171 and the pole 160 .

[0084] By adopting the above-mentioned manufacturing method, during the manufacturing process of the cylindrical battery 100, when the third weld mark 165 is welded, the shell 110 will be in a vertical state with the opening 112 facing upward. Since the posture of the shell 110 is in a vertical state with the opening 112 facing upward during liquid injection and formation, there is no need to change the posture of the shell 110 after the liquid injection and formation are completed. The sealing pin 170 can be directly inserted and then sealed and welded. Therefore, the positioning preparation time of the shell 110 before the sealing pin 170 is welded can be reduced, which is beneficial to improving the production efficiency of the cylindrical battery 100. At the same time, since the third weld mark 165 is performed after the first weld mark 140 and the second weld mark 163 are welded, and when the first weld mark 140 and the second weld mark 163 are welded, the shell 110 is also in a vertical state with the opening 112 facing upward. Therefore, the shell 110 can simultaneously complete the welding of the first weld mark 140, the second weld mark 163 and the third weld mark 165 while maintaining the vertical state with the opening 112 facing upward, thereby saving the auxiliary time of positioning the shell 110 between multiple welding processes, improving the effective working time of the welding equipment, and thus improving the manufacturing efficiency of the cylindrical battery 100.

[0085] In an example of the manufacturing method of the present invention, after step S1, that is, after the electrode assembly 120 is installed from the opening 112 of the shell 110 to the interior of the shell 110, the manufacturing method of the cylindrical battery 100 further includes: welding the second current collecting member 152 and the end wall 113 on the outside of the shell 110 along the arrangement direction of the electrode assembly 120 and the end cover 130 (that is, the vertical direction of the shell 110). Before this step, after the electrode assembly 120 completes the welding of the second electrode tab 124 and the second current collecting member 152, when entering the interior of the shell 110, the second current collecting member 152 will be pressed against the end wall 113 below, and the welding laser is set on the bottom side of the shell 110, that is, the side of the end wall 113 of the shell 110. The welding laser is irradiated from the outside of the end wall 113 to the abutment area between the end wall 113 and the second current collecting member 152, thereby realizing penetrating welding between the end wall 113 and the second current collecting member 152, and forming a fourth weld mark 1521, and the exposed surface of the fourth weld mark 1521 is located on the surface of the end wall 113 facing away from the electrode assembly 120, that is, on the outer surface of the end wall 113. With this arrangement, when the fourth weld mark 1521 is welded, the shell 110 can be kept in a vertical state with the opening 112 facing upward, without changing the placement state of the shell 110. Therefore, the positioning preparation time of the shell 110 before the fourth weld mark 1521 is welded can be saved, thereby improving the work efficiency of this welding step.

[0086] In one example of the manufacturing method of the present invention, please refer to Figure 12The electrode assembly 120 includes a winding core through-hole 126, and the first current collecting member 151 includes an opening 1511. The opening 1511 is arranged corresponding to the winding core through-hole 126 to form a channel 180 for the welding head 190 to enter and exit. The second current collecting member 152 at least partially blocks the winding core through-hole 126. After step S1, that is, after the electrode assembly 120 is installed into the interior of the housing 110 through the opening 112 of the housing 110, and before the end cap 130 is closed over the opening 112, the manufacturing method of the cylindrical battery 100 further includes: along the arrangement direction of the electrode assembly 120 and the end cap 130 (i.e., the vertical direction of the housing 110), the welding head 190 extends from the side of the opening 112 into the channel 180, penetrates the electrode assembly 120, and then presses against the second current collecting member 152 below, thereby pressing the second current collecting member 152 against the end wall 113. The welding head 190 twists back and forth to achieve torque welding between the second current collecting member 152 and the end wall 113, and form a fourth weld mark 1521. The exposed surface of the fourth weld mark 1521 is located on the side surface of the second current collecting member 152 facing away from the end wall 113. This welding method is also performed with the shell 110 in a vertical state with the opening 112 facing upward. It can also save the positioning auxiliary time of the shell 110 before the fourth weld mark 1521 is welded, thereby improving the manufacturing efficiency of the cylindrical battery 100. At the same time, compared with the previous embodiment, this welding method does not require the welding head 190 to be set below the bottom of the shell 110. It only needs to be set above the opening 112 of the shell 110, so that the installation and maintenance of the welding head 190 can be facilitated.

[0087] The cylindrical battery in the present invention is provided with an end cover at the opening of the shell, the end cover seals the opening, and the outer edge of the end cover overlaps the side wall and is welded to the side wall to form a first weld mark, and the first weld mark penetrates the end cover along the arrangement direction of the electrode assembly and the end cover into the interior of the side wall. With this arrangement, when sealing the opening of the shell, the end cover and the side wall can be laser welded along the vertical direction of the shell. Since the welding direction is consistent with the arrangement direction of the electrode assembly and the end cover, that is, consistent with the direction of the electrode assembly entering the shell, when assembling the cylindrical battery, it is only necessary to keep the shell in a vertical state with the opening facing the whole time, and the electrode assembly can be inserted into the shell, the end cover seals the opening, and the sealing welding between the end cover and the side wall can be completed in sequence. Therefore, the frequent falling and standing up of the shell during the production and manufacturing process of the cylindrical battery can be reduced, the waste of mechanical action can be reduced, and the production efficiency of the cylindrical battery can be improved.

[0088] In summary, the present invention effectively overcomes some practical problems in the prior art and thus has high utilization value and practical significance. The above embodiments are merely illustrative of the principles and effects of the present invention and are not intended to limit the present invention. Anyone familiar with the technology may modify or change the above embodiments without departing from the spirit and scope of the present invention. Therefore, all equivalent modifications or changes made by those with ordinary knowledge in the art without departing from the spirit and technical ideas disclosed by the present invention should still be covered by the claims of the present invention.

Claims

1. A cylindrical battery, characterized in that: include: a housing comprising a side wall having an opening; an electrode assembly, disposed in the housing and electrically connected to the housing; an end cover, covering the opening, wherein the outer edge of the end cover overlaps the side wall and is welded to the side wall to form a first weld mark; The first weld mark penetrates the end cover and enters the interior of the side wall along the arrangement direction of the electrode assembly and the end cover.

2. The cylindrical battery according to claim 1, characterized in that: The side wall includes a first end face located on the opening side, and the end cover includes a cover body and a welding portion arranged around the outer periphery of the cover body. The welding portion overlaps the first end face and is welded to the first end face to form the first weld mark. The thickness of the welding portion is less than the thickness of the cover body.

3. The cylindrical battery according to claim 2, characterized in that: The thickness of the welding portion is A, and 0.2mm≤A≤0.4mm. Along the radial direction of the end cover, the surface width of the welding portion away from the electrode assembly is B, and 0.3mm≤B≤0.5mm.

4. The cylindrical battery according to claim 2, characterized in that: Along the thickness direction of the end cover, the surface of the cover body facing away from the electrode assembly protrudes from the surface of the welding portion facing away from the electrode assembly, forming a height difference H1, and 0.05mm≤H1≤0.15mm.

5. The cylindrical battery according to claim 2, characterized in that: Along the thickness direction of the end cover, the cover body extends to the inside of the shell toward one side of the electrode assembly and matches the opening. The dimension of the cover body extending to the inside of the shell is H2, and H2 ≥ 0.2 mm.

6. The cylindrical battery according to claim 1, characterized in that The cylindrical battery also includes a first current collecting member and an electrode column. The first current collecting member is arranged between the electrode assembly and the end cover and is electrically connected to the electrode assembly. The electrode column passes through the end cover and is welded to the first current collecting member to form a second weld mark, and the exposed surface of the second weld mark is located in the same direction as the exposed surface of the first weld mark.

7. The cylindrical battery according to claim 6, characterized in that: The electrode includes a liquid injection hole, and the cylindrical battery also includes a sealing nail; the sealing nail includes a sealing portion and a nail body portion, the sealing portion is located on the side of the nail body portion facing the electrode assembly, and is at least partially inserted into the liquid injection hole to seal the liquid injection hole; the nail body portion is welded to the electrode to form a third weld mark, and the exposed surface of the third weld mark is located in the same direction as the exposed surface of the first weld mark.

8. The cylindrical battery according to claim 6, characterized in that: The side of the sidewall away from the opening includes an end wall, and the cylindrical battery also includes a second current collecting member, which is arranged between the electrode assembly and the end wall and electrically connected to the electrode assembly; the end wall includes a recessed portion recessed toward the electrode assembly side, and the recess is welded to the second current collecting member to form a fourth weld mark; the exposed surface of the fourth weld mark is located in the same direction or opposite direction as the exposed surface of the first weld mark.

9. The cylindrical battery according to claim 8, characterized in that: The first current collecting member includes a first thickened portion, which is welded to the pole to form the second weld mark; the second current collecting member includes a second thickened portion, which is welded to the recess to form the fourth weld mark.

10. A method for manufacturing a cylindrical battery, characterized in that: The manufacturing method comprises: S1: Installing the electrode assembly into the housing through the opening of the housing, wherein the housing includes a side wall; S2: Covering the end cover on the opening, and making the outer edge of the end cover overlap the side wall to form an overlapping area; S3: Keep the end cover and the housing in a stationary state; S4: irradiating the overlapping area with a welding laser from the side of the end cover facing away from the electrode assembly, and performing penetration welding on the overlapping area, so that the end cover seals the opening.

11. The manufacturing method according to claim 10, characterized in that: In steps S1 to S4 , the housing always maintains a vertical state with the opening facing the vertical direction.

12. The manufacturing method according to claim 11, characterized in that: The cylindrical battery further includes a first current collecting member and a second current collecting member, and a first electrode tab and a second electrode tab are formed at both ends of the electrode assembly, respectively. The manufacturing method further includes: welding the first current collecting member to the first electrode tab; The second current collecting member is welded to the second electrode tab.

13. The manufacturing method according to claim 12, characterized in that: The cylindrical battery further includes a pole. Before step S2, the manufacturing method further includes: insulating and fixing the pole to the end cover, and allowing the pole to penetrate the end cover along the thickness direction of the end cover.

14. The manufacturing method according to claim 13, characterized in that: The manufacturing method further comprises: A welding laser is irradiated from a side of the electrode column away from the electrode assembly along an arrangement direction of the electrode assembly and the end cover to weld the electrode column and the first current collecting member and form a second weld mark.

15. The manufacturing method according to claim 14, characterized in that: The pole further includes a liquid injection hole, the cylindrical battery further includes a sealing nail, and the manufacturing method further includes: Inserting the sealing pin into the liquid injection hole, and allowing the sealing pin to seal the liquid injection hole and the second weld mark; A welding laser is irradiated from a side of the sealing pin away from the electrode assembly along an arrangement direction of the electrode assembly and the end cover to weld the sealing pin to the pole.

16. The manufacturing method according to claim 12, characterized in that: The side of the housing away from the opening includes an end wall. After step S1, the manufacturing method further includes: The second current collecting member is welded to the end wall outside the shell along the arrangement direction of the electrode assembly and the end cover; or the second current collecting member is welded to the end wall inside the shell.

17. The manufacturing method according to claim 16, characterized in that: The manufacturing method further includes: irradiating a welding laser from the outside of the housing to the end wall along an arrangement direction of the electrode assembly and the end cover, so as to perform penetration welding on the end wall and the second current collecting member.

18. The manufacturing method according to claim 16, characterized in that: The manufacturing method further includes: extending the welding head from the opening into and through the electrode assembly along the arrangement direction of the electrode assembly and the end cover, and then pressing and abutting against the second current collecting member, so as to torque weld the second current collecting member to the end wall when the welding head is twisted.

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