Positive collector plate and cylindrical lithium battery

Abstract

The positive collector plate comprises a plate body and a bendable tail body extending from the plate body, the plate body is provided with a first hole located in the middle of the plate body and at least one second hole located in the periphery of the first hole, the outer periphery of the plate body is further provided with at least one notch, the area of the first hole is S1, the sum of the areas of the second holes is S2, and the width of the first hole is S1. The sum of the areas of the notches formed by taking the edge line of the outer periphery of the disc body as the reference is S3, the area of the disc body is S4, the area of the disc body is the area of the disc body when the first hole, the second hole and the notch are not formed, (S1 + S2 + S3) / S4 is larger than or equal to 16% and smaller than or equal to 32%, the notches are formed in the outer periphery so that the exhaust rate and the liquid injection efficiency in the battery can be improved, meanwhile, the (S1 + S2 + S3) / S4 is set to be 16%-32%, and therefore the battery is prevented from being damaged. And the exhaust efficiency and the overall structural strength of the disc body can be balanced.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of lithium ion batteries, in particular to a positive current collecting disc and a cylindrical lithium battery. BACKGROUND

[0002] According to the packaging form, the lithium battery can be divided into three forms of square, cylinder and soft package. The cylindrical lithium battery gradually becomes a research hotspot of lithium battery because of good consistency, high production efficiency, strong heat dissipation ability on the system level and other characteristics. The cylindrical battery is usually packaged with a cylindrical steel shell, and the bare battery core is made by winding process to form a cylindrical winding core. The cap is located at the top of the battery and is connected with the positive electrode in the winding core through the positive current collecting disc.

[0003] In the related art, the positive current collecting disc generally includes a disc body and a bendable tail body extended from the disc body. The cylindrical lithium battery is assembled to form a battery after the positive current collecting disc is welded. In actual use, the disc body of the positive current collecting disc needs to be welded with the winding core, and the tail body of the positive current collecting disc needs to be welded with the cap to realize electrical connection. However, if the battery core has a short circuit or other thermal runaway, a large amount of gas will be generated. The disc body is welded with the positive end of the winding core, which hinders / reduces the exhaust rate of the gas, thereby increasing the safety risk of the battery core. As the capacity and energy density of the battery core are required to be higher, the assembly ratio of the battery is very high in the overall design, which greatly affects the liquid injection efficiency of the battery core, increases the liquid injection time of the battery core, reduces the production efficiency, and increases the manufacturing cost of the battery core. Practical new type content

[0004] The present application provides a positive current collecting disc and a cylindrical lithium battery to at least solve the technical problems of low liquid injection efficiency and exhaust rate of the existing cylindrical lithium battery.

[0005] The first aspect of the present application provides a positive current collecting disc for a cylindrical lithium battery, comprising: a disc body and a bendable tail body extended from the disc body, the disc body is used to connect with the winding core, the tail body is used to connect with the cap, the disc body is provided with a first hole located in the middle and at least one second hole located in the outer periphery of the first hole, and at least one notch is further provided on the outer periphery of the disc body, the area of the first hole is S1, the sum of the areas of the second holes is S2, the sum of the areas of the notches formed with the disc body outer periphery edge line as reference is S3, the area of the disc body is S4, the area of the disc body is the area of the disc body without the first hole, the second hole and the notch, and 16%≤(S1+S2+S3) / S4≤32%.

[0006] The positive current collecting disc according to the present application has at least the following beneficial effects:

[0007] The notch is arranged at the outer periphery of the positive current collector plate, which helps to improve the internal exhaust rate and liquid injection efficiency of the battery, and setting (S1+S2+S3) / S4 at 16% to 32% helps to balance the exhaust efficiency and the overall structural strength of the plate body.

[0008] In a possible implementation, 5%≤S3 / S2≤20%, setting S3 / S2 at 5% to 20% helps to balance the welding effect between the plate body and the winding core and the exhaust efficiency of the plate body.

[0009] In a possible implementation, the outer periphery of the plate body includes an arc-shaped edge, and the notch is arranged at the arc-shaped edge; the radius of the arc-shaped edge is L1, the distance from the deepest part of the notch to the center of the arc-shaped edge is L2, and 85%≤L2 / L1≤95%; setting L2 / L1 at 85% to 95% helps to balance the overall structural strength of the plate body and the liquid injection efficiency and exhaust efficiency of the electrolyte.

[0010] In a possible implementation, the outer periphery of the plate body includes an arc-shaped edge, and the notch is arranged at the arc-shaped edge; the distance from the deepest part of the notch to the center of the arc-shaped edge is L2, the distance from the deepest part of the notch to the edge of the second hole is L3, and 10%≤L3 / L2≤30%; setting L3 / L2 at 10% to 30% helps to balance the overall strength of the plate body and the exhaust efficiency.

[0011] In a possible implementation, the outer periphery of the plate body includes an arc-shaped edge, and the notch is arranged at the arc-shaped edge; the radius of the arc-shaped edge is L1, the distance from the center of the second hole to the center of the first hole is L4, and 50%≤L4 / L1≤60%; setting L4 / L1 at 50% to 60% helps to balance the processing convenience of the second hole and the processing space for multiple second holes.

[0012] In a possible implementation, the notch is in the shape of a sector, and the notch forms an included angle α, and 72°≤α≤95°; setting α at 72° to 95° helps to balance the liquid injection and exhaust efficiency and the welding strength of the plate body and the winding core.

[0013] In a possible implementation, the centers of the first hole, the second hole, and the notch are collinear, and in the process of cutting the second hole and the notch, the positive current collector plate needs to be placed on a grinding tool for positioning, and the positions of the second hole and the notch are corresponded, which helps to realize positioning and cutting; meanwhile, if the notch is not collinear with the second hole and the notch, the notch will occupy the welding area, resulting in a reduction in the welding area and affecting the welding effect.

[0014] In a possible implementation, the number of the notches is 3, the number of the second holes is 3, the 3 second holes are arranged around the first hole, the second holes are arranged at positions corresponding to the notches, and the first hole is arranged at the center of the arc-shaped edge, which is beneficial to balance the overall structural strength and the liquid injection and exhaust efficiency of the disc body.

[0015] In a possible implementation, 8mm≤L1≤10mm, which is beneficial to balance the overall strength and the exhaust efficiency of the disc body.

[0016] The second aspect of the embodiments of the present application provides a cylindrical lithium battery, which comprises any one of the positive current collector discs, the shell, the cap, the roll core and the negative current collector disc provided in the above embodiments. The disc body of the positive current collector disc is connected with the roll core, and the tail body of the positive current collector disc is connected with the cap.

[0017] According to the cylindrical lithium battery of the embodiments of the present application, at least the following beneficial effects are achieved:

[0018] The cylindrical lithium battery of the embodiments of the present application is provided with notches at the outer periphery of the positive current collector disc, which is beneficial to improve the internal exhaust rate and the liquid injection efficiency of the battery. Meanwhile, (S1+S2+S3) / S4 is set to be 16% to 32%, which is beneficial to balance the exhaust efficiency and the overall structural strength of the disc body. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed in the description of the embodiments of the present application will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0020] Figure 1 is a structural schematic diagram of a positive current collector disc provided by the embodiments of the present application;

[0021] Figure 2 is a structural schematic diagram of a positive current collector disc provided by the embodiments of the present application;

[0022] Figure 3 is Figure 1 is a partial schematic diagram of A in FIG. 8;

[0023] Figure 4 is another embodiment of a notch in a positive current collector disc provided by the embodiments of the present application;

[0024] Figure 5 is another embodiment of a notch in a positive current collector disc provided by the embodiments of the present application.

[0025] Reference signs:

[0026] 110 - disc body, 111 - first hole, 112 - second hole, 113 - notch, 114 - arc-shaped rim;

[0027] 120 - tail body. DETAILED DESCRIPTION

[0028] Embodiments of the present embodiment are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference signs represent the same or similar elements or elements having the same or similar functions throughout. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present embodiment and cannot be understood as a limitation of the present embodiment.

[0029] In the description of the present embodiment, it should be understood that the orientation description, such as the orientation or position relationship indicated by the upper, lower, front, rear, left, right, etc. is based on the orientation or position relationship shown in the drawings, and is only for the purpose of facilitating the description of the present embodiment and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present embodiment.

[0030] In the description of the present embodiment, the meaning of several is one or more, and the meaning of multiple is more than two. Greater than, less than, more than, etc. are understood as not including the number, and above, below, etc. are understood as including the number. If the first, second is described, it is only for the purpose of distinguishing technical features, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated or the order of technical features indicated.

[0031] In the description of the present embodiment, unless otherwise explicitly limited, the words such as setting, installing, connecting, etc. should be broadly understood, and those skilled in the art can reasonably determine the specific meaning of the above words in the present embodiment in combination with the specific content of the technical solution.

[0032] Example 1:

[0033] As shown in Figure 1 , Figure 2 , Figure 1 and Figure 2A structure diagram of a positive electrode current collector plate provided by an embodiment of the present application is shown, and two diagrams only differ in the reference numerals, and the essential content is not different. The positive electrode current collector plate provided by the embodiment includes a disc body 110 and a bendable tail body 120 extended from the disc body 110. The disc body 110 is used to be connected with a winding core, and the tail body 120 is used to be connected with a cover cap. The disc body 110 is provided with a first hole 111 located at a middle part and at least one second hole 112 located at an outer periphery of the first hole 111. The disc body 110 is further provided with at least one notch 113 at an outer periphery edge. By providing the notch 113 at the outer periphery edge of the disc body 110, firstly, in the case that short circuit or thermal runaway occurs in the battery and a large amount of gas is generated, the notch 113 can be used to shunt part of the gas, thereby improving the exhaust efficiency and improving the safety of the battery. Secondly, the electrolyte injection efficiency of the battery is improved, the electrolyte injection time is reduced, the production efficiency is improved, and the manufacturing cost of the battery is reduced. The outer periphery edge of the positive electrode current collector plate in the related art is continuous and smooth. In the present application, the notch 113 is provided at the outer periphery edge on the basis of the related art. The way of providing the notch 113 is not limited, for example, mechanical cutting, laser cutting, etc.

[0034] In a possible implementation, the area of the first hole 111 is S1, the sum of the areas of the second holes 112 is S2, the sum of the areas of the notches 113 formed with the disc body 110 outer periphery edge as a reference is S3, and the reference line can refer to the dotted line at the notch 113 in Figure 1 The dotted line is used for illustration, and the dotted line represents the shape of the disc body 110 when the disc body 110 is not cut to form the notch 113, and the dotted line is obtained by extending the outer periphery edge of the disc body 110 according to the original outer periphery edge. The area of the disc body 110 is S4, the area of the disc body 110 is the area of the disc body 110 when the first hole 111, the second hole 112 and the notch 113 are not provided, and 16%≤(S1+S2+S3) / S4≤32%. If (S1+S2+S3) / S4 is too small, in the case that short circuit or other thermal runaway occurs in the battery and a large amount of gas is generated, the gas cannot be discharged in time, which easily causes the battery to be out of control and catch fire and explode, the safety performance is reduced, and in the process of electrolyte injection, the electrolyte cannot flow into the winding core through a large channel, the injection rate is reduced, the injection time is increased, and the production efficiency is reduced. If (S1+S2+S3) / S4 is too large, the overall structural strength of the disc body 110 of the positive electrode current collector plate is reduced, and the positive electrode current collector plate is easily deformed during production and transportation, which causes the positive electrode current collector plate to be scrapped and the manufacturing cost of the positive electrode current collector plate to increase. In the process of manufacturing the battery, the positive electrode current collector plate is also easily deformed, and at this time, when the disc body 110 and the winding core are welded, the welding spatter or virtual welding phenomenon is easily caused, which causes the battery to be scrapped, the production yield is reduced, the manufacturing difficulty is increased, and the manufacturing cost is increased. By setting (S1+S2+S3) / S4 to be 16% to 32%, the exhaust efficiency and the overall structural strength of the disc body 110 can be balanced.

[0035] In some embodiments, 5%≤S3 / S2≤20%. If S3 / S2 is too small, the notch 113 area is too small, which affects the exhaust rate when the battery produces a large amount of gas and the liquid injection rate, increases the safety risk of the battery and reduces the efficiency of liquid injection, increases the liquid injection time, and increases the battery manufacturing cost. If S3 / S2 is too large, the notch 113 area is too large, which will occupy the weldable area on the disc surface, causing the weldable area to decrease, causing the overall current-carrying capacity of the battery to decrease after welding, the heat production temperature of the weldable area is high, and the battery performance is affected. Designing S3 / S2 to be 5%-20% helps to balance the welding effect between the disc body 110 and the winding core and the exhaust efficiency of the disc body 110.

[0036] In some embodiments, please refer to Figure 2 The outer periphery of the disc body 110 includes an arc-shaped edge 114, the notch 113 is arranged on the arc-shaped edge 114, the radius of the arc-shaped edge 114 is L1, and the distance from the deepest part of the notch 113 to the center of the arc-shaped edge 114 is L2, 85%≤L2 / L1≤95%. The deepest part of the notch 113 refers to the position closest to the center of the arc-shaped edge 114. If L2 / L1 is too small, the depth of the notch 113 is too deep, the overall structural strength of the disc surface is reduced, and problems such as distortion and deformation occur during manufacturing, which can cause the positive electrode current collector disc to be scrapped, and problems such as explosion and false welding occur when the positive electrode current collector disc is welded with the winding core positive electrode side, causing the battery to be scrapped, the yield of the battery production is reduced, and the manufacturing cost of the battery is increased. If L2 / L1 is too large, the depth of the notch 113 extends inward too shallow, the flow of electrolyte passing through decreases during liquid injection, the liquid injection time becomes longer, the production efficiency decreases, and it is also not conducive to the exhaust of the gas inside the battery when rapid exhaust is required. Set L2 / L1 to 85%-95%, which helps to balance the overall structural strength of the disc body 110 and the efficiency of electrolyte injection and exhaust rate.

[0037] In some embodiments, the distance from the deepest part of the notch 113 to the edge of the second hole 112 is L3, and 10%≤L3 / L2≤30%. L3 / L2 relates to the positional relationship between the notch 113 and the second hole 112. If L3 / L2 is too small, the linear distance between the outer peripheral notch 113 and the second hole 112 is too close, and the structural strength is low. Since the positive current collector plate is required to be thin as a whole due to welding requirements, the positive current collector plate is prone to distortion during the production of the positive current collector plate, or the connection between the notch 113 and the second hole 112 is broken, resulting in scrap and increased manufacturing cost. During battery manufacturing, the positive current collector plate is welded to the positive side of the core. Due to the low strength of the plate surface, the welding area on the plate surface is bent and deformed, causing the flatness to exceed the range, and problems such as popping, virtual welding, and the like occur during welding, resulting in a decrease in battery manufacturing yield, an increase in manufacturing difficulty, and an increase in cost. When L3 / L2 is too large, the notch 113 on the outer periphery of the disc body 110 is too shallow, and the exhaust rate decreases, which is not conducive to the safety of the battery. At the same time, the depth of the notch 113 is not enough, the flow of electrolyte passing through decreases, the liquid injection time becomes longer, and the production efficiency decreases. Setting L3 / L2 to 10%-30% helps to balance the overall strength of the disc body 110 and the exhaust efficiency.

[0038] In some embodiments, the distance from the center of the second hole 112 to the center of the first hole 111 is L4, and 50%≤L4 / L1≤60%. In the related art, the size of the cylindrical lithium battery is basically fixed, that is, the diameter of the cylindrical lithium battery shell is determined, so the diameter of the disc body 110 of the positive current collector plate assembled into the shell is basically determined. L4 / L1 relates to the distance between the second hole 112 and the first hole 111. Since the first hole 111 is located in the middle of the disc body 110, if L4 / L1 is too large, the distance between the second hole 112 and the first hole 111 is too far, which compresses the cutting operation space of the notch 113. If L4 / L1 is too small, the second hole 112 is closer to the first hole 111, which is not conducive to subsequent processing of multiple second holes 112, and reduces the exhaust and liquid injection efficiency of the second hole 112. Setting L4 / L1 to 50%-60% helps to balance the processing convenience of the second hole 112 and the processing space for multiple second holes 112.

[0039] In some embodiments, as Figure 1 and Figure 3As shown, the notch 113 is in the shape of a sector, and the notch 113 forms an included angle a, 72°≤a≤95°. If the included angle a is too small, the electrolyte will be difficult to pass through during the injection of the electrolyte, the injection flow will be small, the injection time will be long, and the production efficiency will be reduced. If the included angle a is too large, the subsequent welding of the disc surface and the positive side of the core will affect the positioning and compression of the welding tool, the welding tool will need to occupy other disc positions, which will cause the welding area to decrease, the welding flow capacity to decrease, the temperature rise at the welding site to increase, and the overall performance of the battery to be affected. In some embodiments, the sector-shaped notch 113 is symmetrical about the radius of the arc-shaped edge 114. Setting a to 72°-95° helps to balance the injection and exhaust efficiency and the welding strength of the disc body 110 and the core.

[0040] In some embodiments, the notch 113 can also have other shapes, for example, as shown in FIG. 6. Figure 4 、 Figure 5 As shown, the notch 113 can be rectangular, arc-shaped, waist-shaped, etc., which is not limited here.

[0041] In some embodiments, the number of notches 113 is 3, and the number of second holes 112 is 3, the 3 second holes 112 are arranged around the first hole 111, the positions of the second holes 112 correspond to the notches 113, and the first hole 111 is arranged at the center of the arc-shaped edge 114. Corresponding the number of notches 113 and the number of second holes 112, and both are set to 3, which is helpful to balance the overall structural strength of the disc body 110 and the injection and exhaust efficiency.

[0042] In some embodiments, the centers of the first hole 111, the second hole 112, and the notch 113 are collinear. In the process of cutting the second hole 112 and the notch 113, the positive current collecting disc needs to be placed on the grinding tool for positioning, and the positions of the second hole 112 and the notch 113 correspond, which is helpful to realize positioning and cutting. At the same time, if the notch 113 is not collinear with the second hole 112 and the notch 113, the notch 113 will occupy the welding area, resulting in a decrease in the welding area and affecting the welding effect.

[0043] In some possible embodiments, the arc-shaped edge 114 includes at least half a circle, two of the three notches 113 are symmetrically distributed with the center as the center, and the other notch 113 is the same distance from the two notches 113. Distributing the three notches 113 evenly on the arc-shaped edge 114 is helpful to make the injection effect more uniform, and is also helpful to exhaust more quickly and uniformly.

[0044] In some possible embodiments, 8mm≤L1≤10mm, which is helpful to balance the overall strength of the disc body 110 and the exhaust efficiency.

[0045] In some possible embodiments, the first hole 111 and the second hole 112 are both circular holes, facilitating the processing of the disc body 110. In some possible embodiments, the diameter of the first hole 111 is greater than the diameter of the second hole 112, and the center of the first hole 111 is coincident with the center of the arc-shaped edge 114. After the assembly of the positive current collector into the battery, the center of the arc-shaped edge 114 generally corresponds to the core shaft of the winding core. Increasing the diameter of the first hole 111 is conducive to making the electrolyte more rapidly injected into the winding core.

[0046] In some possible embodiments, the tail body 120 includes a bending portion, and the assembly state of the positive current collector in the shell of the battery is that the tail body 120 is bent at the bending portion towards the center of the disc body 110, so that the positive current collector can be assembled into the shell. The disc body 110 of the positive current collector faces the winding core, the bent tail body 120 is away from the winding core and faces the cap, and is used for electrically connecting with the cap.

[0047] In some possible embodiments, the tail body 120 is generally long and rectangular, and the tail body 120 includes two opposite sides along the length of the tail body 120. Corresponding portions of the two opposite sides are both inwardly recessed to form a fuse portion. The length of the fuse portion in the width direction of the tail body 120 is less than the length of other portions of the tail body 120 in the width direction. The fuse portion is conducive to fusing the tail body 120 by the heat generated by the large current when the internal short-circuit current of the battery sharply rises, so as to disconnect the circuit and protect the battery.

[0048] Embodiment Two:

[0049] The cylindrical lithium battery provided in this embodiment includes the positive current collector, the shell, the cap, the winding core and the negative current collector in any of the embodiments provided in the foregoing embodiment one. The disc body 110 of the positive current collector is connected with the winding core, and the tail body 120 of the positive current collector is connected with the cap. Since the notch 113 is arranged at the outer periphery of the disc body 110 of the positive current collector, it is conducive to rapid exhaust and liquid injection. By selecting the areas of the notch 113, the first hole 111 and the second hole 112, it is conducive to ensuring the overall structural strength of the disc body 110 under the premise of meeting the exhaust and liquid injection rate.

[0050] For other related features of this embodiment, please refer to the description of the foregoing embodiment one, which will not be repeated here.

[0051] In the description of the present specification, the description of the terms "one embodiment", "some embodiments", "exemplary embodiment", "example", "specific example", or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present embodiment. In the present specification, the exemplary description of the above terms does not necessarily mean the same embodiment or example. Also, the specific features, structures, materials or characteristics described can be appropriately combined in any one or more embodiments or examples.

[0052] Although the embodiments of the present embodiment have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and variations can be made thereto without departing from the principles and spirit of the present embodiment, and the scope of the present embodiment is defined by the claims and their equivalents.

Claims

1. A positive electrode current collector for a cylindrical lithium battery, characterized in that, include: The disc (110) and the bendable tail (120) extending from the disc (110) are provided. The disc (110) has a first hole (111) located in its middle and at least one second hole (112) located on the outer periphery of the first hole (111). The disc (110) also has at least one notch (113) on its outer periphery. The area of ​​the first hole (111) is S1, the sum of the areas of the second holes (112) is S2, the sum of the areas of the notch (113) formed with reference to the outer periphery edge of the disc (110) is S3, the area of ​​the disc (110) is S4, and the area of ​​the disc (110) is the area of ​​the disc (110) without the first hole (111), the second hole (112) and the notch (113), 16% ≤ (S1 + S2 + S3) / S4 ≤ 32%.

2. The positive current collector according to claim 1, characterized in that, 5% ≤ S3 / S2 ≤ 20%.

3. The positive current collector according to claim 1 or 2, characterized in that, The outer periphery of the disc body (110) includes an arc-shaped edge (114), and the notch (113) is provided on the arc-shaped edge (114). The radius of the arc-shaped edge (114) is L1, and the distance from the deepest part of the notch (113) to the center of the arc-shaped edge (114) is L2, where 85% ≤ L2 / L1 ≤ 95%.

4. The positive current collector according to claim 1 or 2, characterized in that, The outer periphery of the disc body (110) includes an arc-shaped edge (114), and the notch (113) is provided on the arc-shaped edge (114). The distance from the deepest part of the notch (113) to the center of the arc-shaped edge (114) is L2, and the distance from the deepest part of the notch (113) to the edge of the second hole (112) is L3, where 10% ≤ L3 / L2 ≤ 30%.

5. The positive current collector according to claim 1 or 2, characterized in that, The outer periphery of the disc body (110) includes an arc-shaped edge (114), the notch (113) is provided on the arc-shaped edge (114), the radius of the arc-shaped edge (114) is L1, the distance from the center of the second hole (112) to the center of the first hole (111) is L4, and 50% ≤ L4 / L1 ≤ 60%.

6. The positive current collector according to claim 1 or 2, characterized in that, The notch (113) is fan-shaped and forms an included angle α, where 72°≤α≤95°.

7. The positive current collector according to claim 1 or 2, characterized in that, The centers of the first hole (111), the second hole (112), and the notch (113) are collinear.

8. The positive current collector according to claim 3, characterized in that, The number of notches (113) is 3, the number of second holes (112) is 3, the 3 second holes (112) are arranged around the first hole (111), the positions of the second holes (112) are arranged corresponding to the notches (113), and the first hole (111) is located at the center of the arc edge (114).

9. The positive current collector according to claim 3, characterized in that, 8mm≤L1≤10mm.

10. A cylindrical lithium battery, characterized in that, Includes a positive current collector, a housing, a cap, a core, and a negative current collector according to any one of claims 1-9, wherein the disk body (110) of the positive current collector is connected to the core, and the tail body (120) of the positive current collector is connected to the cap.

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