Collector plate and battery cell comprising same

Abstract

The invention relates to a collector plate for a negative electrode of a battery cell. The collector plate includes: a main body portion formed as a main body of the collector plate; the welding area is arranged at the approximate center of the main body part; and a connecting portion connecting the welding region and the main body portion, in which the welding region is separated from the main body portion by a through opening except for being connected with the connecting portion.

Description

Technical Field

[0001] The present invention belongs to the field of batteries, and more particularly, the present invention relates to a current collecting plate and a battery cell including the current collecting plate. Background Art

[0002] With the development of society, batteries have been developing rapidly in terms of energy ratio and lifespan. New energy devices using batteries, especially secondary batteries, as energy storage devices have gradually gained favor among consumers, and various types of batteries have been widely used in various electronic devices. Batteries with internal cells are a representative of small-volume batteries. They are small in size and can be repeatedly charged and discharged. They are widely used in various consumer and industrial electronic devices, which can significantly improve the user experience of electronic devices.

[0003] Such secondary batteries can be classified into cylindrical secondary batteries, prismatic secondary batteries or pouch-shaped secondary batteries according to their shapes. Cylindrical secondary batteries have the advantages of high volume energy density, simple structure, easy grouping and standardization. With the development of technology, large cylindrical batteries have gradually become the mainstream direction of the market.

[0004] A cylindrical secondary battery generally includes a cylindrical electrode assembly, a cylindrical can to which the electrode assembly is coupled, an electrolyte injected into the can so that lithium ions can move, and a cap assembly coupled to one side of the can to prevent leakage of the electrolyte and separation of the electrode assembly. In the present application, a single cylindrical secondary battery is also referred to as a battery cell.

[0005] Typical cylindrical secondary batteries, especially those without polar sheets, generally include a current collector or busbar, which is used as a bridging component to provide an electrical connection between the electrode assembly and the corresponding battery terminal. The current collector is usually welded to the inside of the battery cell housing. Due to the very limited access to the components of the battery cell, it may be difficult to achieve and / or verify good welding between the current collector and the battery cell housing.

[0006] Therefore, there is still a need in the art for a current collecting plate and a battery cell including the current collecting plate, which can effectively improve the problem of poor welding caused by the current collecting plate, thereby improving the reliability of the battery cell. Summary of the invention

[0007] One of the objectives of the present application is to provide a current collecting plate and a battery cell including the current collecting plate, which can effectively improve the problem of poor welding caused by the current collecting plate, thereby improving the reliability of the battery cell.

[0008] In order to solve the above technical problems, in a first aspect of the present application, a current collecting plate for a negative electrode of a battery cell is provided, characterized in that the current collecting plate comprises:

[0009] a main body portion formed as a main body of the current collecting plate;

[0010] a weld zone disposed approximately at the center of the body portion; and

[0011] A connecting portion connects the welding area and the main body, wherein in addition to being connected to the connecting portion, the welding area is separated from the main body by a through opening.

[0012] In an embodiment of the first aspect of the present application, the through opening is formed in a substantially U-shape surrounding the welding area.

[0013] In an embodiment of the first aspect of the present application, an embossed portion is provided on the welding area for welding to a housing of the battery cell.

[0014] In an embodiment of the first aspect of the present application, the embossed portion is formed by embossing the welding area itself, or the embossed portion is electrically connected to the welding area.

[0015] In an embodiment of the first aspect of the present application, the current collecting plate includes a first side facing the electrode assembly and a second side facing the shell, the embossed portion is located on the second side and includes a plurality of protrusions, wherein a subset of the plurality of protrusions is configured to be welded to the shell.

[0016] In an embodiment of the first aspect of the present application, the plurality of protrusions are formed in a rectangular arrangement, a circular arrangement, a regular polygonal arrangement or a triangular arrangement.

[0017] In an embodiment of the first aspect of the present application, the welding area includes a flat surface to be connected to the housing of the battery cell by laser welding.

[0018] In an embodiment of the first aspect of the present application, a width of the welding area is greater than a width of the connecting portion.

[0019] In an embodiment of the first aspect of the present application, the width of the connecting portion is 50-80% of the width of the welding area.

[0020] In an embodiment of the first aspect of the present application, the current collecting plate is an integral part obtained by stamping a metal plate.

[0021] In a second aspect of the present application, a battery cell is provided, comprising:

[0022] a cylindrical housing including a first end and a second end opposite the first end, wherein the second end is closed;

[0023] an electrode assembly positioned within the housing between the first end and the second end, the electrode assembly comprising a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; and

[0024] According to the current collecting plate for the negative electrode of the battery cell according to the first aspect of the present application, the current collecting plate is electrically connected to the housing.

[0025] In an embodiment of the second aspect of the present application, the negative electrode, the positive electrode and the separator are rolled into concentric layers around a central hole, and the welding area is coaxial with the central hole.

[0026] In an embodiment of the second aspect of the present application, a convex portion is provided on the welding area for welding to the housing of the battery cell, and the convex portion is coaxial with the central hole.

[0027] In an embodiment of the second aspect of the present application, the welding area is larger than the central hole.

[0028] In the embodiments of the present application, the current collecting plate and the battery cell including the current collecting plate according to the present invention can effectively improve the problem of poor welding caused by the current collecting plate, thereby improving the reliability of the battery cell. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Objects and features of the present invention will become apparent from the following detailed description considered in conjunction with the accompanying drawings. It should be understood, however, that the drawings are designed for illustration purposes only and are not intended to limit the present invention.

[0030] Figure 1 is an exploded perspective view of a battery unit according to an embodiment of the present invention.

[0031] Figure 2 According to one embodiment of the present invention, Figure 1 A plan view of the positive electrode, negative electrode and separator in a battery cell.

[0032] Figure 3 According to an embodiment of the present invention Figure 1 Schematic cross-sectional perspective view of a portion of a battery cell.

[0033] Figure 4A According to one embodiment of the present invention, Figure 1 A plan view of a current collecting plate used with a battery cell.

[0034] Figure 4B According to an embodiment of the present invention Figure 4A Side view of the collector plate.

[0035] Figure 5A According to one embodiment of the present invention, Figure 4A and 4B A plan view of the embossed portion of a current collecting plate.

[0036] Figure 5B According to one embodiment of the present invention, Figure 4A and 4B A side view of the embossed portion of a current collecting plate.

[0037] Figure 6 According to one embodiment of the present invention, Figure 1 A perspective view of a current collecting plate used with a battery cell.

[0038] Figure 7 is subjected to a welding operation according to one embodiment of the present invention Figure 4A and 4B The collector plate Figure 1 A cross-sectional view taken at section AA.

[0039] Figure 8 is a flow chart illustrating a method for assembling or connecting electrical components of a battery cell according to one embodiment of the present invention. DETAILED DESCRIPTION

[0040] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0041] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0042] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first" and "second" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present application, "multiple" means two or more, unless otherwise clearly and specifically defined.

[0043] The various specific technical features and embodiments described in the specific implementation methods can be combined in any suitable manner unless there is any contradiction. For example, different implementation methods can be formed by combining different specific technical features / embodiments / implementations. In order to avoid unnecessary repetition, the various possible combinations of the specific technical features / embodiments / implementations in this application will not be described separately.

[0044] Figure 1 A battery cell 10 according to some embodiments is shown. The battery cell 10 includes a housing 14, an electrode assembly 18 located within the housing 14, a first insulating member 22, and a second insulating member 26. The battery cell 10 also includes a first terminal 30 located at a first end 14a of the housing 14, a second terminal 34 located at a second end 14b of the housing 14, a first conductor 38 located between the electrode assembly 18 and the first terminal 30 in the housing 14, and a second conductor 42 located between the electrode assembly 18 and the second terminal 34 in the housing 14. In the illustrated embodiment, the first conductor 38 is a formable (e.g., bendable, ductile, operable, etc.) current collector, busbar, and / or the like configured to electrically connect the electrode assembly 18 to the first terminal 30. Similarly, the second conductor 42 is a formable (e.g., ductile, operable, etc.) current collector, busbar, and / or the like configured to electrically connect the electrode assembly 18 to the second terminal 34.

[0045] like Figure 1As shown, the housing 14 generally provides a housing for the electrical components (e.g., electrode assembly 18, first terminal 30, first conductor 38, second conductor 42, etc.) of the battery cell 10. In some embodiments, some or all of the electrical components are located in the housing 14. In the illustrated embodiment, the housing 14 is made of an insulating material such as plastic or other non-conductive materials. In some embodiments, the housing 14 may be made of a conductive material such as steel, aluminum or other conductive metals. In some embodiments, the second end 14b is closed, and the housing 14 is used as a negative terminal to facilitate external connection of the battery cell 10, for example, the second terminal 34 may be integrated into the housing 14 at the second end 14b to form an integral cylindrical can with one end open. In one or more embodiments, during the assembly process of the secondary battery, the upper portion of the cylindrical can may be open. Therefore, during the assembly process of the secondary battery, the electrode assembly 18 and the second current collecting plate 42, etc. may be connected together first and then inserted into the cylindrical can through the open upper portion.

[0046] Reference now Figure 2 , and briefly refer to Figure 3 , the electrode assembly 18 includes a positive electrode 46, a negative electrode 50, and one or more separators 54 located between the positive electrode 46 and the negative electrode 50. In the illustrated embodiment, the positive electrode 46 includes a positive electrode sheet, the negative electrode 50 includes a negative electrode sheet, and the separator 54 includes a membrane or a separator. Figure 3 As shown, these positive electrodes 46, negative electrodes 50 and separators 54 can be rolled into concentric layers around a central hole 58 of the electrode assembly 18 to form a jelly roll. In some embodiments, the electrode assembly 18 is rolled around a central pin that can be removed after the rolling operation is completed to form the central hole 58.

[0047] Refer again Figure 1 And continue to refer to Figure 3 , once wound, the first end 18a and the second end 18b of the electrode assembly 18 may include exposed or uncoated portions of the positive electrode 46 and the negative electrode 50. The exposed portion at the first end 18a may be flattened into a flat rough surface to form a first flattened portion 62, and the exposed portion at the second end 18b may be flattened into a flat rough surface to form a second flattened portion 66. In some embodiments not shown, the first flattened portion 62 is a negative electrode flattened portion, and the second flattened portion 66 is a positive electrode flattened portion. The first flattened portion 62 provides abutment surface for the first conductor 38 so that the first conductor 38 can be connected (e.g., welded, fixed, adhered, fastened, etc.) to the electrode assembly 18. Similarly, the second flattened portion 66 provides a connection for the second conductor 42, as will be discussed in more detail below. Therefore, the first conductor 38 can be configured to electrically connect the first flattened portion 62 to the first end 14a of the shell 14. The second conductor 42 can be configured to electrically connect the second flattened portion 66 to the second end 14b of the shell 14.

[0048] In some embodiments, the first insulating member 22 is made of plastic and / or rubber. The first insulating member 22 may be provided with a through hole, which allows the first conductor 38 to extend through the first insulating member 22 and make electrical contact with the first terminal 30. The first flattened portion 62 may be provided or disposed in the first insulating member 22 to prevent contact between the first flattened portion 62 and the housing 14. The first terminal 30 may be provided in the second insulating member 26 supported on the first insulating member 22. In some embodiments, once the electrode assembly 18 and other electrical components are disposed in the housing 14, the first insulating member 22 and the second insulating member 26 are crimped onto the first terminal 30.

[0049] Still refer to Figure 1 , the first terminal 30 can provide electrical contact with an external device so as to provide power from the electrode assembly 18 to the external device. In some embodiments, the first terminal 30 can receive power from the external device to recharge the electrode assembly 18. In some embodiments, the first terminal 30 is a positive terminal electrically connected to a positive electrode sheet (e.g., positive electrode 46) within the electrode assembly 18, and the second terminal 34 is a negative terminal connected to a negative electrode sheet (e.g., negative electrode 50). For example, the first terminal 30 can connect the positive electrode 46 of the electrode assembly 18 to the positive terminal of an external device powered by the battery cell 10. In some embodiments, the first terminal 30 is made of metal, such as stainless steel.

[0050] In some embodiments of the present invention, the second conductor 42 is, for example, a negative current collecting plate. Figure 6 According to one embodiment of the present invention, Figure 1 3D view of a current collecting plate 42 used with a battery cell. In one embodiment of the present invention, the second conductor or current collecting plate 42 is an integral piece obtained by stamping a thin metal plate. For example, the second conductor 42 includes a main body 70. Preferably, the main body 70 constitutes the outer contour of the second conductor 42. Figure 6As shown, at the center of the main body 70, a welding area 80 is provided. In one embodiment of the present invention, the welding area has a flat surface so that when it is welded to the shell of the battery cell using laser welding, the flat surface of the welding area contacts the shell, thereby facilitating the operation of the laser welding. In one embodiment of the present invention, the welding area 80 is a current collecting boss 80. In one embodiment of the present invention, a convex portion 82 is provided on the current collecting boss 80 for welding to, for example, the second terminal 34 or the bottom of the shell 14. In one embodiment of the present invention, the convex portion 82 is formed by stamping the current collecting boss 80 itself, that is, the current collecting boss 80 itself can constitute the convex portion 82. In another embodiment of the present invention, the convex portion 82 is formed as a single component independent of the current collecting boss 80, and is electrically connected (e.g., welded) to the current collecting boss 80, and occupies most of the area of ​​the current collecting boss 80. A connecting portion 72 is provided between the current collecting boss 80 and the main body 70 to connect the current collecting boss 80 to the main body 70. In one embodiment of the present invention, the current collecting boss 80 and the connecting portion 72 are formed, for example, by cutting or ablating a portion of a metal plate. For example, this is achieved by forming a through opening or a cutout portion 74 on the metal plate by a laser beam, a cutter and / or a punching device. In one embodiment of the present invention, the through opening 74 may have a substantially C-shaped or U-shaped shape, so that the connecting portion 72 and the current collecting boss 80 together constitute a cantilever beam, and the current collecting boss 80 can move relative to the main plane of the main body 70 or the second conductor 42.

[0051] Reference now Figures 4A-4B , the second conductor 42 includes a first side 76 and a second side 78 opposite the first side 76. The second conductor 42 can be connected to the second end 18B of the electrode assembly 18, so that the first side 76 of the second conductor 42 faces the electrode assembly 18, the second side 78 faces the second end 14B of the shell 14, and is configured to connect the second end 18B of the electrode assembly 18 to the second end 14B of the shell 14. The second side 78 of the second conductor 42 may include a raised portion 82 for improving the welding operation of welding the second conductor 42 to the shell 14. In some embodiments, the raised portion 82 is located at the approximate center of the second side 78 of the second conductor 42 and is coaxial with the center hole 58. In one embodiment of the present invention, as Figure 7 As schematically shown, in terms of projected area, the welding area is larger than the central hole. In one embodiment of the present invention, a projection area is formed on the first side 76 in the direction extending from the connecting portion 72 and the current collecting boss 80 (for example, Figure 1The welding portion is parallel to the AA direction of the electrode assembly 18, and the welding portion is used, for example, to be welded to the electrode assembly 18, especially to the second flattened portion 66 of the electrode assembly 18, such as Figure 1 In an embodiment of the present invention not shown, the welding portion includes two welding portions, such as two protruding ribs, located on the first side 76 of the main body 70 and respectively located on both sides of the current collecting boss 80 to help form a good weld with the second flattened portion 66.

[0052] refer to Figure 5A , the embossed portion 82 may have a plurality of protrusions 86. The embossed portion 82 may also have a plurality of recesses 90. The second conductor 42 may be stamped or otherwise embossed with the protrusions 86 and recesses 90. The protrusions 86 and recesses 90 may be formed on the second conductor 42 such that each recess 90 is defined by the space between adjacent protrusions 86. Each protrusion 86 and recess 90 may have substantially equal dimensions. In some embodiments, the protrusion 86 may be formed by soldering solder onto the second conductor 42. In some embodiments, the embossed portion 82 is a separate component soldered to the second conductor 42. As shown in FIG. Figure 5B As shown, in some embodiments, the embossed portion 82 may have a sawtooth shaped cross-section, however, the cross-section of the embossed portion 82 may be any suitable shape.

[0053] In some embodiments, protrusions 86 may be arranged in rows and columns within embossed portion 82 such that the perimeter of embossed portion 82 is approximately square. Figures 4A-4B and Figure 6 In the illustrated embodiment, the embossed portion 82 includes 49 protrusions 86 arranged in seven rows and seven columns. However, the number of protrusions 86 is not limited to 49, and the number of rows and columns is not limited to seven. Figure 5A-5B As shown, the embossed portion 82 may include 121 convex portions 86 arranged in eleven rows and eleven columns. In other embodiments, the embossed portion 82 may include 16 convex portions 86 arranged in four rows and four columns. In some embodiments, the number of convex portions 86 included in each row or column varies by row or column according to the needs of a given application. In some embodiments of the present invention, the plurality of convex portions may be formed into a rectangular arrangement, a circular arrangement, a regular polygonal arrangement, or a triangular arrangement.

[0054] The protrusion 86 may be formed by a protrusion protruding from the surface of the second conductor 42, and the recess 90 may be formed by the surface of the second conductor 42. The embossed portion 82 may be formed of the same or different material as the second conductor 42. For example, one or both of the second conductor 42 and the embossed portion 82 may be formed of nickel. In some embodiments, one or both of the second conductor 42 and the embossed portion 82 are formed of copper and include a nickel coating.

[0055] Figure 7 A cross-sectional view of a battery cell 10 undergoing a welding operation to electrically couple the second end 18b of the electrode assembly 18 to the second end 14b of the battery cell housing 14 is shown. It is noted that the second conductor 42 has been welded to the electrode assembly 18, and in particular, to the second flattened portion 66 of the electrode assembly 18. That is, the second conductor 42 and the electrode assembly 18 have been welded together to form a single unit. During the welding operation, the electrode assembly 18 and the second conductor 42 are inserted into the battery cell housing 14 from above, and the welding head 94 is inserted through the central hole 58 of the electrode assembly 18 to approach the second end 18b of the electrode assembly 18, so that the welding head 94 contacts the first side 76 of the second conductor 42. A subset or number of the protrusions 86 of the embossed portion 82 on the second side 78 of the second conductor 42 is configured to melt and weld the second conductor 42, in particular the embossed portion 82, to the second end 14b of the battery cell housing 14 in response to the welding head 94 performing the welding operation. The welding operation may include applying a voltage to the first side 76 of the second conductor 42, thereby causing current to flow through the second conductor 42 to the housing 14. In some examples, the welding head 94 is a resistance welding head.

[0056] The number of protrusions 86 configured to melt may depend on a number of factors, such as the duration of the welding operation (e.g., the duration that the current is applied to the first side 76 of the second conductor 42), the magnitude of the current applied to the first side 76 of the second conductor 42, or a combination thereof. However, in some examples, other parameters or factors may affect the melting of the protrusions 86 and / or the overall welding of the second conductor to the second end 14b of the battery cell housing 14. In some embodiments, the subset of protrusions 86 configured to melt includes all of the protrusions 86. In some embodiments, the subset of protrusions 86 configured to melt includes at least half of the protrusions 86. In some embodiments, the subset of protrusions 86 configured to melt includes less than half of the protrusions 86, and the protrusion 86 positioned closest to the approximate center of the second conductor 42 may be configured to melt first during the welding operation. Therefore, when the subset of protrusions 86 configured to melt is less than the total number of protrusions 86 included in the embossed portion 82, the subset includes the most centrally positioned protrusion 86.

[0057] A subset of the protrusions 86 is configured to melt so that the required peel force of the second conductor 42 is increased. In addition, melting of all or a subset of the protrusions reduces the resistance between the housing 14 and the second conductor 42 in the battery cell 10.

[0058] The protrusions 86 formed on the second conductor 42 melt more efficiently than a flat current collecting plate because the protrusions 86 provide a higher resistance between the second conductor 42 and the battery case 14, which in turn generates more heat when current flows through the protrusions 86, thereby reducing the possibility of a failed welding process. In addition, the embossed portion 82 provides reduced resistance in the battery cell 10 because the subset of protrusions 86 configured to melt and the remaining protrusions 86 remain in contact with the battery cell case 14 after the welding process.

[0059] As mentioned above, the connecting portion 72 and the current collecting boss 80 together constitute a cantilever beam suspended from the main body 70 of the second conductor 42. In the present invention, due to the adoption of this design, many advantages are obtained. For example, since the portion of the second conductor 42 for welding to the electrode assembly 18 (e.g., the welding portion) is physically separated from the portion of the second conductor 42 for welding to the battery housing 14 (e.g., the embossed portion 82) by the through opening 74, the thermal deformation generated during the welding of the second conductor 42 with the electrode assembly 18 is not easily conducted to the embossed portion 82, because the through opening 74 that substantially surrounds the current collecting boss 80 releases most of the stress or strain. It can be said that the through opening 74 is formed as a stress release opening. That is, the thermal deformation generated during the welding of the second conductor 42 with the electrode assembly 18 is not easy to cause the embossed portion 82 to deform or curl, thereby overcoming or avoiding the subsequent poor welding of the second conductor 42 with the battery housing 14 that may be caused. Thus, the reliability of the battery is improved. Similarly, during the welding of the embossed portion 82 to the battery case 14, the thermal deformation generated by the welding is not easily conducted to the main body 72, especially the welding portion with the electrode assembly 18, due to the through opening 74, thereby overcoming or avoiding the welding detachment or cracking of the second conductor 42 and the electrode assembly 18 caused during the welding of the battery case 14, and improving the reliability of the welding. In addition, since the embossed portion 82 can move to a certain extent relative to the main body 70, the welding resistance during welding is reduced, and the welding process can be better implemented.

[0060] On the other hand, the current collecting boss 80 or the convex part 82 of the second conductor 42 as a cantilever beam is welded to the battery case 14, and the main body 70 of the second conductor 42 is welded to the electrode assembly 18, and these two different welding locations allow a certain elasticity or relative movement between each other, so as to prevent or substantially prevent the welding area between the electrode assembly 18 and the second conductor or the current collecting plate 42 at the first side 76 and / or the welding area between the battery case 14 and the second conductor or the current collecting plate 42 at the second side 78 from separating when vibration or impact acts on the battery cell 10. In other words, the welding area at the first side 76 located at the periphery and the welding area at the second side 78 located at the center can move freely and elastically / independently from each other, so the separation phenomenon of the welding area can be prevented or substantially prevented. In one embodiment of the present invention, the width of the welding area 80 is greater than the width of the connecting portion 72. That is, the width of the connecting portion 72 is reduced relative to the welding area 80, which helps the welding area at the first side 76 located at the periphery and the welding area at the second side 78 located at the center to move freely and elastically / independently from each other, while also providing a larger through opening 74 to make it easier for the electrolyte to flow through. In one embodiment of the present invention, the width of the connecting portion is 50-80% of the width of the welding area.

[0061] As an optional implementation of this embodiment, the shape and size of the second conductor or current collecting plate 42 can be appropriately adjusted according to the type of battery to which it is applied. Figure 1 Taking the current collecting plate 42 applied to a cylindrical battery as an example, the battery shell 14 can be roughly elliptical, the current collecting plate 42 can be roughly disc-shaped, and the central axis of the current collecting boss 80 in the length direction can coincide with the diameter of the shell 14.

[0062] Reference again Figure 4A and 4B , also shows possible dimensions of the second conductor 42. The second conductor 42 may have a width W1 in the transverse direction. In some embodiments, the width W1 is between about 3.00 mm and about 10.00 mm (e.g., about 6.00 mm). However, for a given application, values ​​less than 3.00 mm and greater than 10.00 mm may also be considered as needed.

[0063] The second conductor 42 can have an overall length L1 in the longitudinal or extension direction. In some embodiments, the length L1 is between about 14.00 mm and about 22.00 mm (e.g., about 18.00 mm). However, values ​​less than 14.00 mm and greater than 22.00 mm may also be considered depending on the needs of a given application.

[0064] The embossed portion 82 may have a total width and a total length. In some embodiments, the total width of the embossed portion 82 is between about 1.50mm and about 4.50mm (e.g., about 3.00mm). However, for a given application, a value less than 1.5mm and greater than 4.50mm may also be considered as needed. In some embodiments, the total length of the embossed portion 82 is between about 1.50mm and about 4.50mm (e.g., about 3.00mm). However, for a given application, a value less than 1.50mm and greater than 4.50mm may also be considered as needed. Therefore, in general, the embossed portion 82 has a larger area, which makes it easier for the second conductor 42 to be automated, such as the second conductor 42 is more easily positioned and grasped by automated equipment to facilitate the assembly and assembly of the battery cell 10.

[0065] Each protrusion 86 may have a diameter D1 ( Figure 5A ). In some embodiments, the diameter D1 is between about 0.15 mm and about 0.45 mm (e.g., about 0.30 mm). However, for a given application, values ​​less than 0.15 mm and greater than 0.45 mm may also be considered as needed.

[0066] like Figure 4B As shown, the second conductor 42 may have a first thickness T1 and a second thickness T2. The first thickness T1 may be the thickness of the second conductor 42 at an area of ​​the conductor 42 that does not include the embossed portion 82, and the second thickness T2 may be the thickness of the second conductor 42 at an area of ​​the conductor 42 that includes the embossed portion 82. In some embodiments, the first thickness T1 is between about 0.05 mm and about 0.15 mm (e.g., about 0.10 mm). However, for a given application, values ​​less than 0.05 mm and greater than 0.15 mm may also be considered as needed. In some embodiments, the second thickness T2 is between about 0.10 mm and 0.30 mm (e.g., about 0.20 mm). However, for a given application, values ​​less than 0.10 mm and greater than 0.30 mm may also be considered as needed. As mentioned above, due to the design with a through opening 74 between the main body 70 and the current collecting boss 80, shrinkage deformation is not easy to occur during the welding of the second conductor 42, which brings or saves about 0.10 mm of height space for the electrode assembly 18 or the battery cell, which is conducive to utilizing this height space to further increase the capacity of the battery cell 10.

[0067] Figure 8 8 is a flow chart showing a method or process 800 for assembling or connecting electrical components of a battery cell 10. Each block in the method 800 is Figure 8804, the positive electrode 46, the negative electrode 50 and the separator 54 are rolled into concentric layers around the central hole 58 of the electrode assembly 18 to form a jelly roll, thereby forming the electrode assembly 18. In box 808, the electrode assembly 18 is flattened to produce the second flattened portion 66, as described in detail above. In box 812, a portion of the second side 78 of the second conductor 42 is molded. In one embodiment, the second side 78 of the second conductor 42 is embossed with a embossed portion 82 by a stamping operation, wherein a force is applied to the first side 76 of the second conductor 42. In some examples, during the stamping process, a mold or press having complementary raised and recessed portions associated with the desired embossed portion can be used. Although process 800 describes the use of a stamping process to form an embossed portion, it is contemplated that other processes and / or techniques can be used to form the embossed portion, depending on the needs of a given application.

[0068] In frame 816, the electrode assembly 18 is electrically connected to the first side 76 of the second conductor 42. For example, the second flattened portion 66 of the electrode assembly 18 is welded to the first side 76 of the second conductor 42, for example, welded to the weld portion of the second conductor 42. In frame 820, a welding head (e.g., welding head 94) is inserted through the central hole 58 of the electrode assembly 18 and contacts the second conductor 42, specifically the first side 76 of the second conductor 42. In frame 824, current is applied to the first side 76 of the second conductor 42 through the welding head to perform a resistance welding operation. However, other welding operations or processes, such as laser welding, arc welding, flattening welding and / or other welding operations, are also contemplated depending on the needs of a given application. In frame 828, based on the applied welding operation, the second side 78 of the second conductor 42 is welded to the battery cell housing 14.

[0069] Although this specification is described in accordance with the implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other implementation modes that can be understood by those skilled in the art. The scope of the present invention is defined by the appended claims rather than the above description, and therefore it is intended that all changes within the meaning and scope of the equivalent elements of the claims are included in the present invention.

[0070] For those skilled in the art, the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, the above embodiments should be regarded as exemplary and non-restrictive.

Claims

1. A current collector for a negative electrode of a battery cell, characterized in that: The current collecting plate comprises: a main body portion formed as a main body of the current collecting plate; a weld zone disposed approximately at the center of the body portion; and A connecting portion connects the welding area and the main body, wherein in addition to being connected to the connecting portion, the welding area is separated from the main body by a through opening.

2. The current collecting plate according to claim 1, wherein: The through opening is formed in a substantially U-shape surrounding the welding area.

3. The current collecting plate according to claim 2, wherein: The welding area is provided with an embossed portion for welding to the housing of the battery cell.

4. The current collecting plate according to claim 3, wherein: The embossed portion is formed by embossing the pad itself, or the embossed portion is electrically connected to the pad.

5. The current collecting plate according to claim 3, wherein: The current collecting plate includes a first side facing the electrode assembly and a second side facing the case, the relief portion is located on the second side and includes a plurality of protrusions, wherein a subset of the plurality of protrusions is configured to be welded to the case.

6. The current collecting plate according to claim 5, wherein: The plurality of protrusions are formed in a rectangular arrangement, a circular arrangement, a regular polygonal arrangement or a triangular arrangement.

7. The current collecting plate according to claim 2, wherein: The welding area includes a flat surface to be connected to the housing of the battery cell by laser welding.

8. The current collecting plate according to any one of claims 1 to 7, wherein: The width of the welding area is greater than the width of the connecting portion.

9. The current collecting plate according to claim 8, wherein: The width of the connecting portion is 50-80% of the width of the welding area.

10. The current collecting plate according to any one of claims 1 to 7, wherein: The current collecting plate is an integral part obtained by punching a metal plate.

11. A battery cell, comprising: a cylindrical housing including a first end and a second end opposite the first end, wherein the second end is closed; an electrode assembly, the electrode assembly being positioned within the housing and between the first end and the second end, the electrode assembly comprising a positive electrode, a negative electrode, and a separator between the positive electrode and the negative electrode; as well as The current collecting plate for the negative electrode of a battery cell according to any one of claims 1 to 10, wherein the current collecting plate is electrically connected to the housing.

12. The battery cell according to claim 11, wherein: The negative electrode, the positive electrode and the separator are rolled into concentric layers around a central hole, and the welding area is coaxial with the central hole.

13. The battery cell according to claim 11 or 12, wherein: The welding area is provided with an embossed portion for welding to the housing of the battery cell, and the embossed portion is coaxial with the central hole.

14. The battery cell according to claim 12, wherein: The welding area is larger than the central hole.

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