Collector plate and battery cell comprising same

Abstract

The present invention relates to a collector plate for a positive electrode of a battery cell, the collector plate comprising: a first connection part formed as a main body part of the collector plate, the first connection part being for welding to the positive electrode of the battery cell; the second connecting part is arranged in the middle of the main body part; and a narrow portion connecting the first connection portion and the second connection portion, the narrow portion extending through a virtual center of the body portion. The collector plate is folded at the narrowed portion during manufacturing of the battery cell, where the first and second connection portions have a first dimension defining a first rated current, and the narrowed portion has a second dimension defining a second rated current less than the first rated current, and where the first and second connection portions have a second dimension defining a second rated current less than the first rated current. The second dimension is smaller than the first dimension.

Description

Technical Field

[0001] The present invention belongs to the field of batteries, and more particularly, 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 electrode sheets, usually 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. For example, the positive current collector is usually welded between the first terminal or cap of the battery cell and the electrode assembly. Due to the small size of the current collector, when the current collector is welded to the first terminal or cap, the heat can be easily conducted to the welding part between the current collector and the electrode assembly, and it may also cause pressure imbalance and cause cold welding and over-welding, which may make it difficult to achieve good welding between the current collector and the electrode assembly and the battery terminals.

[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 positive electrode of a battery cell is provided, characterized in that the current collecting plate comprises:

[0009] a first connection portion, the first connection portion being formed as a main body of the current collecting plate, the first connection portion being used for welding to a positive electrode of a battery cell;

[0010] A second connecting portion disposed substantially at the center of the main body; and

[0011] a narrow portion connecting the first connection portion and the second connection portion, the narrow portion extending through a virtual center of the main body, the current collecting plate being folded at the narrow portion during manufacture of the battery cell, wherein the first connection portion and the second connection portion have a first dimension defining a first rated current, and the narrow portion has a second dimension defining a second rated current less than the first rated current, the second dimension being less than the first dimension.

[0012] 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.

[0013] In an embodiment of the first aspect of the present application, the first connection portion is configured to be electrically connected to an electrode assembly of a battery cell, and the second connection portion is configured to be electrically connected to a cap of the battery cell.

[0014] In an embodiment of the first aspect of the present application, the collecting plate is formed in a shape roughly like the letter E, including a vertically extending portion and an upper lateral extension portion, a middle lateral extension portion and a lower lateral extension portion extending laterally in the same direction from the vertically extending portion, and the middle lateral extension portion is longer than the upper lateral extension portion and the lower lateral extension portion.

[0015] In an embodiment of the first aspect of the present application, the vertically extending portion and the upper lateral extending portion and the lower lateral extending portion are formed as the first connecting portion, and the middle lateral extending portion is formed as the second connecting portion and the narrow portion.

[0016] In an embodiment of the first aspect of the present application, the intermediate laterally extending portion is formed as a laterally extending handle, and the narrow portion is narrower than the second connecting portion.

[0017] In an embodiment of the first aspect of the present application, the second connection portion is formed in a substantially circular shape, and the second connection portion is configured to be welded to the first terminal or the cap of the battery cell on the periphery.

[0018] In an embodiment of the first aspect of the present application, a groove is formed between the upper lateral extension portion and the narrow portion, and a groove is formed between the lower lateral extension portion and the narrow portion.

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

[0020] In an embodiment of the first aspect of the present application, during manufacture of the battery cell, the current collecting plate is bent once at the narrow portion.

[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 a positive electrode of a battery cell according to the first aspect, the current collecting plate is electrically connected between the electrode assembly and the first end.

[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 second connecting portion of the current collecting plate is coaxial with the central hole.

[0026] In an embodiment of the second aspect of the present application, the current collecting plate is bent once at the narrow portion, and a welding area between the second connecting portion and the first end is coaxial with the central hole.

[0027] In an embodiment of the second aspect of the present application, the welding area is located on the outer circumference of the second connecting portion, and the welding area is larger in diameter 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 1is 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 4 is a plan view of a current collecting plate according to another embodiment of the present invention, which can be used Figure 1 A battery cell, wherein the current collecting plate is in an unformed state.

[0034] Figure 5 is a cross-sectional perspective view of a battery cell according to another embodiment of the present invention, showing a battery cell after being formed and positioned in the battery cell Figure 4 The collector plate.

[0035] Figure 6 is a perspective view of a portion of a battery cell according to another embodiment of the present invention, showing the Figure 4 The current collecting plate is welded to the first terminal. DETAILED DESCRIPTION

[0036] 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.

[0037] 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.

[0038] 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.

[0039] 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.

[0040] 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. In one embodiment of the present invention, the first conductor 38 is a positive current collector. 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. In one embodiment of the present invention, the second conductor 42 is a negative current collecting plate.

[0041] In some embodiments, the electrode cell 10 can have a nominal voltage between about 1 V and about 5 V, and a nominal capacity between about 1 Ah and about 5 Ah or greater (e.g., up to about 9 Ah). The electrode cell 10 can employ any rechargeable chemistry type, such as lithium ("Li"), lithium ion ("Li-ion"), other lithium-based chemistries, nickel cadmium ("NiCd"), nickel metal hydride ("NiMH"), etc.

[0042] like Figure 1 As shown, the housing 14 generally provides a housing for the electrical components of the battery cell 10 (e.g., electrode assembly 18, first terminal 30, first conductor 38, second conductor 42, etc.). 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 positive current collector 38 and the negative current collector 42, etc. may be electrically connected together first, and then inserted into the cylindrical can through the open upper portion.

[0043] 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.

[0044] 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.

[0045] Combined with reference Figure 5 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 that allows the first conductor 38 to extend through the first insulating member 22 and to 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 a 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.

[0046] Still refer to Figure 1 , the first terminal 30 and the second terminal 34 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 and the second terminal 34 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.

[0047] In some embodiments of the present invention, the first conductor 38 is, for example, a positive current collecting plate.

[0048] In one embodiment of the present invention, the second conductor 42 may include a connection portion 82 in the form of a welding plate that is connected to the second friction portion 66 to provide electrical communication between the second terminal 34 and the second end 18b of the electrode assembly 18. Similar to the first conductor 38, the second conductor 42 may be formed of aluminum, nickel, copper, and / or other conductive materials.

[0049] Continue to refer Figure 5 , the first conductor 38 also includes a hole 86 coaxially arranged with the central hole 58 of the electrode assembly 18, and a narrow portion 198 located between the first connection portion 174 and the second connection portion 178. The first connection portion 174 and the second connection portion 178 may have a first size defining a first rated current, and the narrow portion 198 may have a second size defining a second rated current. The second size may be smaller than the first size, and the second rated current may be smaller than the first rated current. In one embodiment of the present invention, the width of the narrow portion 198 is 50-80% of the width of the second connection portion 178. In one embodiment of the present invention, the first connection portion 174 is used for welding to the positive electrode of the battery cell 10.

[0050] In one embodiment of the present invention, the narrow portion 198 extends through the virtual center of the main body. The advantage of such a design is that there is no need to open a center hole. After the narrow portion is folded upward, the center hole of the roll core can be exposed, and the electrolyte can be directly injected.

[0051] Figure 4 According to an embodiment of the present invention, Figure 1 3D view of a current collecting plate 138 used with a battery cell. In one embodiment of the present invention, the first conductor or current collecting plate 138 is an integral piece obtained by stamping a thin metal plate. For example, the first conductor or current collecting plate 138 is formed in a shape of a letter E, including a vertical extension portion and a lateral extension portion extending laterally from the vertical extension portion in the same direction, and the middle lateral extension portion is longer than the upper and lower lateral extension portions. Figure 4 As shown, the first conductor 138 includes a first connecting portion 174 as a main body. In one embodiment of the present invention, the first connecting portion 174 is all parts of the letter E shape except the middle lateral extension portion. That is, the first connecting portion 174 includes a vertical extension portion 1741, and an upper lateral extension portion 1742 and a lower lateral extension portion 1743 extending laterally from the vertical extension portion 1741. In addition, the first conductor 138 also includes a middle lateral extension portion or a lateral extension handle. In one embodiment of the present invention, the first connecting portion 174 is connected to the welding area 1740 (reference Figure 6) is welded to the first friction portion 62 by laser welding, spot welding, ultrasonic welding, etc. In one embodiment of the present invention, the laterally extending handle includes a second connection portion 178 and a narrow portion 198 connecting the second connection portion 178 to the first connection portion 174. The second connection portion 178 is configured to be electrically connected to the first terminal 30 by laser welding, spot welding, ultrasonic welding, etc. In one embodiment of the present invention, the narrow portion 198 is narrower than the second connection portion 178, so that the narrow portion 198 provides a current flow limiting member (e.g., a fuse).

[0052] Thus, the narrow portion 198 can be formed as an overcurrent protection device, such as a fuse, formed integrally with the first conductor 138, so that in response to the current exceeding a predetermined value, the narrow portion 98 can interrupt the current between the first friction portion 62 and the first terminal 30. For example, when the current exceeds a predetermined value (e.g., the rated current of the material forming the narrow portion 198), the narrow portion 198 of the first conductor 138 can melt. In one example, the predetermined value can be 120% of the nominal current rating of the battery cell. However, values ​​greater than 120% of the rated rating or less than 120% of the rated rating are also contemplated.

[0053] Reference now Figure 5 , the first connection portion 174 and the second connection portion 178 may be folded to form the first conductor 138 as shown in FIG. Figure 5 The U-shape shown is laid flat. For example, Figure 5 A perspective view of the first conductor 138 is shown, wherein the first conductor 138 is in a formed state.

[0054] During an overcurrent event (e.g., when the current exceeds a predetermined value), as the current increases, the narrow portion 198 and the first and second connecting portions 174, 178 heat up. The first and second connecting portions 174, 178 are rated to reach a higher heat than the narrow portion 198, so that the narrow portion 198 provides a current flow limiting member (e.g., a fuse). That is, the maximum current flowing through the first conductor 138 is equal to the maximum current flowing through the narrow portion 198. Once the current exceeds the maximum current of the narrow portion 198, the narrow portion 198 melts or otherwise separates from the remainder of the first conductor 138 by an air gap and interrupts the current between the first friction portion 62 and the first terminal 30. In other words, the first and second connecting portions 174, 178 of the first conductor 138 have a first size that defines a first rated current, and the narrow portion 198 of the first conductor 138 has a second size that defines a second rated current, so that the second size is smaller than the first size, and the second rated current is smaller than the first rated current.

[0055] refer to Figure 4 The first conductor or current collecting plate 138 also includes a welding portion to be welded to the first friction portion 62, such as Figure 1 In one embodiment of the present invention, a first welding portion 1745 is provided on the vertical extension portion 1741, for example Figure 4 In one embodiment of the present invention, a second welding portion 1745 is provided on the upper lateral extension portion 1742, for example Figure 4 In one embodiment of the present invention, a third welding portion 1747 is provided on the lower lateral extension portion 1743, for example Figure 4 The first welding portion 1745 and / or the second welding portion 1745 and / or the third welding portion 1747 facilitate welding to the first friction portion 62 .

[0056] Continue to refer Figure 4 A groove 202 is formed between the upper lateral extension portion 1742 and the narrow portion 198 to release stress generated during welding. In another embodiment of the present invention, a groove 204 is formed between the lower lateral extension portion 1743 and the narrow portion 198 to release stress generated during welding. Since the first connection portion 174 and the second connection portion 178 are separated from each other by the grooves 202 and 204, this improves the stress release when welding to, for example, the cap or the first terminal 30, and avoids the phenomenon of cold welding and over welding caused by pressure imbalance.

[0057] Figure 5 is a cross-sectional perspective view of a battery cell 10 according to another embodiment of the present invention, showing a battery cell 10 after being formed and positioned in the battery cell 10. Figure 4 The collecting plate 138 is provided. Figure 6 is a perspective view of a portion of a battery cell 10 according to another embodiment of the present invention, showing the battery cell 10 during the assembly process. Figure 4 The current collecting plate 138 in is welded to the first terminal 30. In one embodiment of the present invention, for example, referring to Figure 4 , the second connection portion 178 is formed into a substantially circular shape. That is, for example Figure 6 As shown, the welding area 206 between the second connecting portion 178 and the first end 30 is coaxial with the central hole 58 of the electrode assembly 18. In one embodiment of the present invention, the welding area is located on the outer periphery of the second connecting portion 178, and the welding area 206 is larger in diameter than the central hole 58 of the electrode assembly 18.

[0058] refer to Figure 6, the second connection portion 178 is welded to the first terminal 30 or the cap on the periphery, which avoids the current collecting plate 138 being welded on the periphery, because such welding may be easily eccentric and may easily cause fire. In the present invention, the second connection portion 178 is formed into a circle for welding, so that welding is more reliable and the electrical connection between the current collecting plate 138 and the first terminal 30 is more secure.

[0059] In addition, compared with the current collector adopting an S-shaped structure or a structure with two bends, the current collector 138 according to the present invention adopts a single bend, which saves space in the battery cell, for example, frees up a height of about 0.3 mm, thereby being more helpful in increasing the capacity of the battery cell. In addition, the current collector 138 according to the present invention adopts a single bend, which can better ensure the safety of the battery, because in the case of a secondary bend, for example, after one of the bends is disconnected due to a fuse, the other bend forms, for example, an elastic arm with elasticity, and the elastic arm, when released, may cause the battery cell to be electrically connected to the cap or the first terminal 30 again, thereby causing potential dangers and safety hazards.

[0060] 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.

[0061] 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 positive electrode of a battery cell, It is characterized in that The current collecting plate comprises: a first connection portion, the first connection portion being formed as a main body of the current collecting plate, the first connection portion being used for welding to a positive electrode of a battery cell; A second connecting portion disposed in the middle of the main body; and a narrow portion connecting the first connection portion and the second connection portion, the narrow portion extending through a virtual center of the main body, the current collecting plate being folded at the narrow portion during manufacture of the battery cell, wherein the first connection portion and the second connection portion have a first dimension defining a first rated current, and the narrow portion has a second dimension defining a second rated current less than the first rated current, the second dimension being less than the first dimension.

2. The current collecting plate according to claim 1, in, The current collecting plate is a unitary member obtained by stamping a metal plate.

3. The current collecting plate according to claim 1 or 2, in, The first connection portion is configured to be electrically connected to an electrode assembly of a battery cell, and the second connection portion is configured to be electrically connected to a cap of the battery cell.

4. The current collecting plate according to claim 1 or 2, in, The collecting plate is formed in a substantially letter E shape, including a vertical extension portion and an upper lateral extension portion, a middle lateral extension portion and a lower lateral extension portion extending laterally from the vertical extension portion in the same direction, wherein the middle lateral extension portion is longer than the upper lateral extension portion and the lower lateral extension portion.

5. The current collecting plate according to claim 4, in, The vertically extending portion and the upper and lower lateral extending portions are formed as the first connecting portion, and the middle lateral extending portion is formed as the second connecting portion and the narrow portion.

6. The current collecting plate according to claim 5, in, The intermediate laterally extending portion is formed as a laterally extending shank, and the narrow portion is narrower than the second connecting portion.

7. The current collecting plate according to claim 6, in, The second connection portion is formed in a substantially circular shape, and the second connection portion is configured to be welded to a first terminal or a cap of a battery cell on an outer circumference.

8. The current collecting plate according to claim 7, in, A groove is formed between the upper lateral extension portion and the narrow portion, and a groove is formed between the lower lateral extension portion and the narrow portion.

9. The current collecting plate according to claim 6, in, The width of the narrow portion is 50-80% of the width of the second connecting portion.

10. The current collecting plate according to any one of claims 1 to 9, in, During the manufacture of the battery cell, the current collecting plate is once bent at the narrow portion.

11. A battery cell, include: 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 According to any one of claims 1 to 10, the current collecting plate for the positive electrode of the battery cell is electrically connected between the electrode assembly and the first end.

12. The battery cell according to claim 11, in, The negative electrode, the positive electrode and the separator are rolled into concentric layers around a central hole, and the second connecting portion of the current collecting plate is coaxial with the central hole.

13. The battery cell according to claim 11 or 12, in, The current collecting plate is bent once at the narrow portion, and a welding area between the second connecting portion and the first end is coaxial with the central hole.

14. The battery cell according to claim 13, in, The welding area is located on the outer circumference of the second connecting portion, and the welding area is larger in diameter than the central hole.

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