A lithium-ion cylindrical battery

Abstract

The utility model relates to a cylindrical battery technical field, put forward a kind of lithium ion cylindrical battery, including roll core, positive current collector, negative current collector and cap end plate;Multiple first weld marks are equipped on the disc surface;The radius of the disc surface is R 10 , the span of the first weld mark along its length direction is L 10 , the span of the first weld mark along its width direction is W 10 , wherein, L 10 / R 10 =48%~62%, W 10 / R 10 =20%~30%;Second weld mark is equipped on the tail body, and the second weld mark is the welding track of the tail body and the cap end plate;The radius of the cap end plate is R 30 , the span of the second weld mark along its length direction is L 30 , the span of the second weld mark along its width direction is W 30 , wherein, L 30 / R 30 =56%~76%, W 30 / R 30 =15%~32%;Multiple third weld marks are equipped on the negative current collector.The utility model can take into account the overcurrent capacity and processing efficiency of battery by the span of first weld mark, second weld mark and third weld mark is reasonably limited, to effectively improve the overall performance of battery.

Description

Technical Field

[0001] This utility model relates to the field of cylindrical battery technology, and in particular to a lithium-ion cylindrical battery. Background Technology

[0002] Lithium-ion cylindrical batteries, as a key component in the field of energy storage, have attracted much attention in recent years due to their high energy density, long cycle life, and good safety performance. These batteries employ a cylindrical design and typically consist of core components such as positive electrode materials, negative electrode materials, electrolyte solution, and separators. Energy storage and release are achieved through the reversible insertion and extraction of lithium ions between the positive and negative electrodes.

[0003] The current collector is located at the connection between the positive and negative electrodes and the tabs of the battery, and it serves as a bridge in the current transmission process. It includes a positive current collector and a negative current collector. In the assembly process of lithium-ion cylindrical batteries, the positive current collector and the negative current collector need to be fixed and connected to the positive and negative tabs at both ends of the core by means of laser welding or ultrasonic welding, so that lithium ions can shuttle between the positive and negative electrodes.

[0004] For example, the utility model disclosed in announcement number CN220895786U discloses a positive current collector, a negative current collector, and a cylindrical battery with all tabs. The positive current collector is configured to include a plate body, a tail body, and a connecting piece. Positive welding patterns are provided on the plate body to achieve welding and fixing of the plate body and the positive tab. Negative welding patterns are provided on the negative current collector to achieve welding and fixing of the negative current collector and the negative tab.

[0005] The area of ​​the weld lines directly affects the overall performance of the battery, but the above-mentioned technical solutions do not reasonably set the area of ​​the weld lines. If the area of ​​the weld lines is too small, the area of ​​the corresponding welding position of the component is reduced, resulting in an increase in the internal resistance of the battery. At the same time, the current carrying capacity of the corresponding welding position is weakened, and the temperature rise at the welding position is increased, affecting the battery performance. If the area of ​​the weld lines is too large, it will not only fail to improve the internal resistance at the welding position, but will also increase the welding time, leading to a decrease in welding efficiency, an increase in the risk of welding defects, and an increase in the manufacturing cost of the battery. Utility Model Content

[0006] In view of this, this utility model proposes a lithium-ion cylindrical battery. By reasonably setting the span of the welding positions of the positive electrode current collector and the negative electrode current collector, the battery's current carrying capacity and processing efficiency can be taken into account, thereby effectively improving the overall performance of the battery.

[0007] The technical solution of this utility model is implemented as follows: This utility model provides a lithium-ion cylindrical battery, including a core, a positive current collector, a negative current collector, and a cap end plate. The positive current collector includes a plate surface and a tail body. The plate surface and the negative current collector are welded and fixed to the positive and negative electrode tabs at both ends of the core, respectively. The tail body is fixedly disposed on the plate surface and welded and fixed to the cap end plate.

[0008] The disk surface has multiple first solder marks, which are the welding paths between the disk surface and the positive electrode tab; the radius of the disk surface is R. 10 The first solder mark has a span of L along its length. 10 The first solder mark has a span of W along its width direction. 10 , where L 10 / R 10 =48%~62%, W 10 / R 10 =20%~30%;

[0009] The tail section has a second weld mark, which is the welding trajectory between the tail section and the cap end plate; the radius of the cap end plate is R. 30 The second solder mark has a span of L along its length. 30 The second solder mark has a span of W along its width direction. 30 , where L 30 / R 30 =56%~76%, W 30 / R 30 =15%~32%;

[0010] The negative electrode current collector has multiple third solder marks, which are the welding paths between the negative electrode current collector and the negative electrode tab; the radius of the negative electrode current collector is R. 20 The span of the third solder mark along its length is L. 20 The span of the third solder mark along its width direction is W. 20 , where L 20 / R 20 =37%~57%, W 20 / R 20 =17% to 36%.

[0011] Based on the above technical solutions, the preferred option is L. 10 =4mm~6mm, W 10 =2mm~3mm.

[0012] Further optimized, L 30 =3.5mm~4.5mm, W 30 =1mm~2mm.

[0013] Further optimized, L 20 =3.5mm~5.5mm, W 20 =1.6mm~3.4mm.

[0014] Based on the above technical solutions, preferably, the first solder mark includes a plurality of parallel and spaced positive electrode solder lines, wherein the positive electrode solder lines are wavy or spiral.

[0015] The distance between the opposite sides of two adjacent positive electrode bonding wires is W. 101 The span of the positive electrode bonding wire along its width direction is W. 102 Among them, W 101 =0.3mm~0.5mm, W 102 = 0.4mm~0.6mm.

[0016] Based on the above technical solution, preferably, the line width of the second solder mark is W. 301 Among them, W 301 =0.2mm~0.4mm.

[0017] More preferably, the third solder mark includes a plurality of parallel and spaced negative electrode solder lines, the negative electrode solder lines being wavy or spiral in shape;

[0018] The spacing between two adjacent negative electrode bonding wires is W 202 Among them, W 202 = 0.6mm~1.1mm.

[0019] More preferably, the difference between the span of the negative electrode bonding wire along its width direction and its wire width is W. 201 The linewidth of the negative electrode bonding wire is W. 203 Among them, W 201 =0.15mm~0.35mm, W 203 = 0.1mm~0.3mm, and W 203 <W 201 .

[0020] More preferably, the positive electrode bonding wire, the negative electrode bonding wire, and the second solder mark all include multiple straight portions and multiple rounded corner portions, which are alternately and continuously arranged to form a wavy line shape;

[0021] In the positive electrode bonding wire, the angles between the straight portion and the two adjacent straight portions are A and B, respectively; in the second solder mark, the angles between the straight portion and the two adjacent straight portions are E and F, respectively; and in the negative electrode bonding wire, the angles between the straight portion and the two adjacent straight portions are C and D, respectively, where A = 50°~75°, B = 50°~75°, C = 70°~120°, D = 70°~120°, E = 25°~65°, and F = 25°~65°.

[0022] Based on the above technical solutions, preferably, the width of the tail body is L. 300 , where L 300 =5mm~7mm, R 10 = 8.5mm~9.6mm, R 20 = 8.5mm~10.5mm, R 30 =5.29mm~7.29mm.

[0023] The lithium-ion cylindrical battery of this invention has the following advantages over the prior art:

[0024] (1) By reasonably limiting the span of the first, second and third solder marks, the overcurrent capacity and processing efficiency of the battery can be balanced, thereby effectively improving the overall performance of the battery.

[0025] (2) By further defining the shape and specifications of the first, second and third solder marks, the overcurrent capacity of the battery can be further improved, the temperature rise of the battery can be reduced, the processing efficiency of the battery can be improved, and the processing cost of the battery can be reduced. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0027] Figure 1 This is a front view of a cylindrical lithium-ion battery according to the present invention.

[0028] Figure 2 This is a top view of the positive electrode current collector in a cylindrical lithium-ion battery according to this utility model.

[0029] Figure 3 This is a top view of the disk surface in a cylindrical lithium-ion battery according to this utility model.

[0030] Figure 4This is a top view of the positive electrode bonding wire in a cylindrical lithium-ion battery according to the present invention.

[0031] Figure 5 This is a front view of the tail section and end cap plate of a cylindrical lithium-ion battery according to this utility model.

[0032] Figure 6 This is a front view of the second solder mark in a cylindrical lithium-ion battery according to the present invention.

[0033] Figure 7 This is a top view of the negative electrode current collector in a cylindrical lithium-ion battery according to this utility model.

[0034] Figure 8 This is a top view of the negative electrode bonding wire in a cylindrical lithium-ion battery according to the present invention.

[0035] Among them: 1. Core; 2. Positive current collector; 21. Plate surface; 22. Tail body; 201. First solder mark; 202. Second solder mark; 2011. Positive welding wire; 3. Negative current collector; 301. Third solder mark; 3011. Negative welding wire; 4. Cap end plate. Detailed Implementation

[0036] The technical solutions of this utility model will be clearly and completely described below with reference to specific embodiments. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0037] This utility model discloses a cylindrical lithium-ion battery, comprising a core 1, a positive current collector 2, a negative current collector 3, and a cap assembly. The core 1 has a positive electrode tab and a negative electrode tab at both ends, respectively. Figure 1 As shown, the positive current collector 2 is fixedly mounted on the positive electrode tab and welded to the cap assembly, while the negative current collector 3 is welded to the negative electrode tab, thereby enabling the core 1 to conduct with the positive current collector 2 and the negative current collector 3.

[0038] The cap assembly consists of multiple components. The cap assembly is located at one end of the battery casing as the cap end plate 4. The positive electrode current collector 2 includes a plate surface 21 and a tail body 22. The plate surface 21 is welded and fixed to the positive electrode tab. The tail body 22 is fixedly set on the plate surface 21 and welded and fixed to the cap end plate 4, thereby realizing the connection between the positive electrode tab and the cap assembly.

[0039] like Figure 3As shown, the disk surface 21 is provided with multiple first solder marks 201. The first solder marks 201 are the welding trajectory between the disk surface 21 and the positive electrode tab. The welding head moves along the path of the first solder marks 201 to realize the welding between the disk surface 21 and the positive electrode tab.

[0040] like Figure 5 As shown, the tail body 22 is provided with a second weld mark 202. The second weld mark 202 is the welding trajectory between the tail body 22 and the cap end plate 4. The welding head moves along the path of the second weld mark 202 to achieve the welding between the tail body 22 and the cap end plate 4.

[0041] like Figure 7 As shown, the negative current collector 3 is provided with multiple third solder marks 301. The third solder marks 301 are the welding trajectory between the negative current collector 3 and the negative electrode tab. The welding head moves along the path of the third solder marks 301 to realize the welding between the negative current collector 3 and the negative electrode tab.

[0042] The areas of the disk 21 and the negative electrode current collector 3 are relatively large. It is preferable to arrange multiple first solder marks 201 and multiple third solder marks 301 in a circumferential array around the axis of the core 1 to improve the fixing firmness and stability of the current collector and the electrode tab.

[0043] like Figure 3 and Figure 4 As shown, the first solder mark 201 includes a plurality of parallel and spaced positive electrode solder lines 2011, such as... Figure 7 and Figure 8 As shown, the third weld mark 301 includes multiple parallel and spaced negative electrode weld lines 3011. The positive electrode weld line 2011, the second weld mark 202 and the negative electrode weld line 3011 can all be set to a wavy or spiral shape or other curved shape. Within the same span, the welding length of the curved weld line is greater, which can not only enhance the connection strength of the relevant components, but also improve the welding quality and ensure the overall performance of the battery.

[0044] like Figure 2 As shown, the radius of disk 21 is R. 10 ,like Figure 3 As shown, the span of the first solder mark 201 along its length direction is L. 10 The first solder mark 201 has a span of W along its width direction. 10 .

[0045] like Figure 5 As shown, the width of the tail body 22 is L. 300 The radius of the cap end plate 4 is R. 30 The span of the second solder mark 202 along its length is L. 30 The span of the second solder mark 202 along its width direction is W. 30 .

[0046] like Figure 7 As shown, the radius of the negative current collector 3 is R. 20 The span of the third solder mark 301 along its length is L. 20 The span of the third solder mark 301 along its width direction is W. 20 .

[0047] In some embodiments, L 10 / R 10 =48%~62%, meaning the span of the first solder mark 201 along its length is 48%, 54%, or 62% of the radius of the disk surface 21, etc. If L 10 / R 10 If the span of the first solder mark 201 along its length is less than 48%, it will reduce the firmness of the fixation between the plate 21 and the positive electrode tab. At the same time, it will also make the internal resistance at the soldering position too large, causing heat to concentrate at the soldering point and resulting in excessive rate-rate temperature rise of the battery; if L 10 / R 10 If the span of the first solder mark 201 is greater than 62%, it will not only lead to a longer process cycle and increased processing costs, but also cause the soldering position to easily deviate from the solderable area on the plate 21.

[0048] In some embodiments, W 10 / R 10 =20%~30%, that is, the span of the first solder mark 201 along its width direction is 20%, 25%, or 30% of the radius of the disk surface 21, etc. If W 10 / R 10 If the span of the first solder mark 201 is less than 20%, the span along its width direction will be too small, which will reduce the firmness of the fixation between the plate 21 and the positive electrode tab. At the same time, it will also make the internal resistance at the soldering position too large, causing heat to concentrate at the soldering point and resulting in excessive rate-rate temperature rise of the battery; if W 10 / R 10 If the span is greater than 30%, the first solder mark 201 will have too large a span along its width direction, which will not only increase the processing difficulty, but also cause the soldering position to easily deviate from the solderable area on the plate 21.

[0049] Furthermore, R is preferred. 10 =8.5mm~9.6mm, L 10 =4mm~6mm, W 10 =2mm~3mm, thus balancing the firmness of the fixing of the plate 21 and the positive electrode tab and the current carrying capacity, and improving the welding efficiency of the plate 21 and the positive electrode tab.

[0050] Furthermore, R 10 =9.1mm, L 10 =5mm, W 10 =2.3mm.

[0051] In some embodiments, W 30 / R 30 =15%~32%, that is, the span of the second weld mark 202 along its width direction is 15%, 24%, or 32% of the radius of the cap end plate 4, etc. If W 30 / R 30 If the span of the second weld mark 202 is less than 15%, the effective welding area between the tail body 22 and the cap end plate 4 will be reduced, the current carrying capacity will be weakened, the temperature rise at the welding position will be increased, and the battery performance will be affected; if W 30 / R 30 If the span of the second weld mark 202 is greater than 32%, then the span along its width direction is too large. It will not provide much improvement to the internal resistance between the tail body 22 and the cap end plate 4, but it will increase the welding time, reduce the welding efficiency, and at the same time, it will increase the risk of welding defects and increase the welding defect rate.

[0052] In some embodiments, L 30 / R 30 =56%~76%, meaning the span of the second weld mark 202 along its length is 56%, 66%, or 76% of the radius of the cap end plate 4, etc. If L 30 / R 30 If the span of the second weld mark 202 along its length is less than 56%, the effective welding area between the tail body 22 and the cap end plate 4 is reduced, the current carrying capacity is weakened, the temperature rise at the welding position is increased, and the battery performance is affected; if L 30 / R 30 If the span of the second weld mark 202 along its length is too large, it will not significantly improve the internal resistance between the tail body 22 and the cap end plate 4, but it will increase the welding time, reduce the welding efficiency, and at the same time, increase the risk of welding defects and increase the welding defect rate.

[0053] Furthermore, L 300 =5mm~7mm, R 30 =5.29mm~7.29mm, L 30 =3.5mm~4.5mm, W 30 =1mm~2mm, thereby balancing the firmness of the fixation between the tail body 22 and the cap end plate 4 and the flow capacity, and improving the welding efficiency and welding quality between the tail body 22 and the cap end plate 4.

[0054] Furthermore, L 300 =6mm, R 30 =6.29mm, L 30 =4mm, W 30 =1.5mm.

[0055] In some embodiments, L 20 / R20 =37%~57%, that is, the span of the third solder mark 301 along its length is 37%, 47%, or 57% of the radius of the negative electrode current collector 3, etc. If L 20 / R 20 If the span of the third solder mark 301 along its length is less than 37%, the current-carrying capacity between the negative electrode current collector 3 and the negative electrode tab will be weakened, resulting in greater heat generation at the soldering position during overcurrent, leading to a higher temperature rise and affecting battery performance; if L 20 / R 20 If the weld length is greater than 57%, then the span of the third weld mark 301 along its length is too large, the welding path is too long, and it will not provide much improvement to the internal resistance between the negative current collector 3 and the negative electrode tab. However, it will increase the welding time, reduce the welding efficiency, and at the same time, it will increase the risk of welding defects, increase the welding defect rate, and reduce the welding reliability between the negative current collector 3 and the negative electrode tab.

[0056] In some embodiments, W 20 / R 20 =17%~36%, that is, the span of the third solder mark 301 along its width direction is 17%, 27%, or 36% of the radius of the negative electrode current collector 3, etc. If W 20 / R 20 If the weld width is less than 17%, the span of the third weld mark 301 along its width direction is too small, and multiple negative electrode weld lines 3011 are too concentrated. This can easily cause heat accumulation during welding, leading to defects such as weld burn-through and spalls, and increasing the welding defect rate. 20 / R 20 If the span is greater than 36%, then the span of the third weld mark 301 along its width direction is too large, and the multiple negative electrode weld lines 3011 are too far apart, which will increase the stroke of the weld head, resulting in a decrease in welding efficiency and welding capacity.

[0057] Furthermore, R 20 = 8.5mm~10.5mm, L 20 =3.5mm~5.5mm, W 20 =1.6mm~3.4mm, thus taking into account both the fixing firmness of the negative electrode current collector 3 and the negative electrode tab and the current carrying capacity, and improving the welding efficiency and welding quality of the negative electrode current collector 3 and the negative electrode tab.

[0058] Furthermore, R 20 =9.5mm, L 20 =4.5mm, W 20 =2.5mm.

[0059] like Figure 4 As shown, the distance between the opposite sides of two adjacent positive electrode bonding wires 2011 is W. 101 The span of the positive electrode bonding wire 2011 along its width direction is W. 102.

[0060] In some embodiments, W 101 =0.3mm~0.5mm, that is, the distance between opposite sides of two adjacent positive electrode bonding wires 2011 is 0.3mm, 0.4mm or 0.5mm, etc. If W 101 If the distance between two adjacent positive electrode bonding wires 2011 is less than 0.3mm, it will lead to defects such as bursts during welding, reducing the connection reliability at the welding position; if W 101 If the distance is greater than 0.5mm, the spacing between two adjacent positive electrode bonding wires 2011 will be too large, which will not only increase the processing difficulty, but also cause the welding position to deviate from the weldable area on the plate surface 21, resulting in uneven current flow and affecting the connection strength of the welding position.

[0061] In some embodiments, W 102 =0.4mm~0.6mm, that is, the span of the positive electrode bonding wire 2011 along its width direction is 0.4mm, 0.5mm or 0.6mm, etc. If W 102 If the span of the positive electrode bonding wire 2011 is less than 0.4mm, it will lead to problems such as welding bursts, affecting the connection reliability at the welding position; if W 102 If the span of the positive electrode bonding wire 2011 is greater than 0.6mm, it will not only increase the processing difficulty, but also cause the welding position to deviate from the weldable area on the plate 21, resulting in uneven current flow and affecting the connection strength of the welding position.

[0062] Furthermore, W 101 =0.4mm, W 102 =0.5mm, to balance the current carrying capacity and welding effect at the welding point between the plate 21 and the positive electrode tab.

[0063] like Figure 6 As shown, the line width of the second solder mark 202 is W. 301 .

[0064] In some embodiments, W 301 =0.2mm~0.4mm, that is, the line width of the second solder mark 202 is 0.2mm, 0.3mm or 0.4mm, etc. If W 301 If the line width is less than 0.2mm, the line width of the second solder mark 202 is small, the effective welding area between the tail body 22 and the cap end plate 4 is insufficient, the current carrying capacity is weakened, the temperature at the welding point rises, and the battery performance is affected; if W 301 If the line width is greater than 0.4mm, the second weld mark 202 will be large, which will not only affect the appearance of the second weld mark 202, but also easily cause the problem of energy concentration at the welding position during the welding process, resulting in welding defects such as explosion points and discoloration.

[0065] Furthermore, W 301=0.3mm, to balance the flow capacity and welding effect at the welding point between the tail body 22 and the cap end plate 4.

[0066] like Figure 8 As shown, the difference between the span of the negative electrode bonding wire 3011 along its width direction and its wire width is W. 201 The spacing between two adjacent negative electrode bonding wires 3011 is W. 202 The linewidth of the negative electrode bonding wire 3011 is W. 203 .

[0067] In some embodiments, W 201 =0.15mm~0.35mm, that is, the difference between the span of the negative electrode bonding wire 3011 along its width direction and its wire width is 0.15mm, 0.25mm or 0.35mm, etc. If W 201 If the span of the negative electrode bonding wire 3011 is less than 0.15mm, the span along its width direction will be too small, reducing the welding path length. This will not only decrease the structural strength of the welding position but also weaken the current carrying capacity. If W 201 If the span is greater than 0.35mm, the span of the negative electrode welding wire 3011 along its width direction is too large, resulting in the distance between two adjacent negative electrode welding wires 3011 being too close, which may lead to defects such as welding explosions.

[0068] In some embodiments, W 202 =0.6mm~1.1mm, meaning the spacing between two adjacent negative electrode bonding wires 3011 is 0.6mm, 0.8mm, or 1.1mm, etc. If W 202 If the weld width is less than 0.6mm, then the two adjacent negative electrode welding wires 3011 are too close together, resulting in concentrated heat during welding, poor heat dissipation, and a high risk of defects such as spalling at the welding point; if W 202 If the distance is greater than 1.1mm, then the two adjacent negative electrode welding wires 3011 are too far apart, which will increase the stroke of the welding head, resulting in a decrease in welding efficiency and production capacity.

[0069] In some embodiments, W 203 = 0.1mm~0.3mm, and W 203 <W 201 That is, the linewidth of the negative electrode bonding wire 3011 is 0.1mm, 0.2mm, or 0.3mm, etc. If W 203 If the linewidth is less than 0.1mm, the negative electrode bonding wire 3011 is too small, reducing the current-carrying area at the bonding position and weakening the current-carrying capacity. This leads to an increase in temperature at the bonding position, affecting battery performance. If W 203 If the width is greater than 0.3mm, the line width of the negative electrode bonding wire 3011 is too large. This will not optimize the internal resistance of the battery, but it will increase the area of ​​the welding position and affect the welding reliability.

[0070] Preferably, the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202 are all wavy in shape, such as... Figure 4 , Figure 6 and Figure 8 As shown, the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202 each include multiple straight portions and multiple rounded corner portions. The multiple straight portions and multiple rounded corner portions are arranged alternately and continuously, thereby forming a wavy line shape around the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202.

[0071] like Figure 4 , Figure 6 and Figure 8 As shown, the angles between the straight portion of the positive electrode bonding wire 2011 and its two adjacent straight portions are A and B, respectively; the angles between the straight portion of the second solder mark 202 and its two adjacent straight portions are E and F, respectively; and the angles between the straight portion of the negative electrode bonding wire 3011 and its two adjacent straight portions are C and D, respectively.

[0072] A, B, C, D, E, and F respectively reflect the degree of bending of the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202.

[0073] In some embodiments, A = 50°–75°, B = 50°–75°, C = 70°–120°, D = 70°–120°, E = 25°–65°, and F = 25°–65°. If A, B, C, D, E, and F are too small, the two adjacent straight sections will be more concentrated, resulting in concentrated heat and poor heat dissipation during welding, which can easily lead to welding defects such as cratering and discoloration. If A, B, C, D, E, and F are too large, the curvature of the welding position will be poor. In order to ensure sufficient welding area, the length of the welding position needs to be increased, which will not only increase the welding difficulty and reduce the welding efficiency, but also make it easy for the welding position to deviate from the weldable area of ​​the relevant component, affecting the battery's overcurrent capacity and overall performance.

[0074] Preferably, A=B, E=F, and C=D to improve the uniformity of the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202, so as to ensure the stability, uniformity, and reliability of the welding position. To ensure the welding efficiency and current carrying capacity of the positive electrode bonding wire 2011, the negative electrode bonding wire 3011, and the second solder mark 202, it is preferable to set A=B=60°, C=D=95°, and E=F=41°.

[0075] The above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A lithium-ion cylindrical battery, characterized in that: The device includes a core (1), a positive current collector (2), a negative current collector (3), and a cap end plate (4). The positive current collector (2) includes a plate surface (21) and a tail body (22). The plate surface (21) and the negative current collector (3) are welded and fixed to the positive and negative electrode tabs at both ends of the core (1), respectively. The tail body (22) is fixedly disposed on the plate surface (21) and welded and fixed to the cap end plate (4). The disk surface (21) is provided with a plurality of first solder marks (201), the first solder marks (201) being the welding trajectory between the disk surface (21) and the positive electrode tab; the radius of the disk surface (21) is R. 10 The first solder mark (201) has a span of L along its length direction. 10 The first solder mark (201) has a span of W along its width direction. 10 , where L 10 / R 10 =48%~62%, W 10 / R 10 =20%~30%; The tail body (22) is provided with a second weld mark (202), which is the welding trajectory between the tail body (22) and the cap end plate (4); the radius of the cap end plate (4) is R. 30 The second solder mark (202) has a span of L along its length direction. 30 The second solder mark (202) has a span of W along its width direction. 30 , where L 30 / R 30 =56%~76%, W 30 / R 30 =15%~32%; The negative electrode current collector (3) is provided with multiple third solder marks (301), which are the welding paths between the negative electrode current collector (3) and the negative electrode tab; the radius of the negative electrode current collector (3) is R. 20 The third solder mark (301) has a span of L along its length direction. 20 The span of the third solder mark (301) along its width direction is W. 20 , where L 20 / R 20 =37%~57%, W 20 / R 20 =17% to 36%.

2. A lithium-ion cylindrical battery as described in claim 1, characterized in that: L 10 =4mm~6mm,W 10 =2mm~3mm。 3. A lithium-ion cylindrical battery as described in claim 1, characterized in that: L 30 =3.5mm~4.5mm,W 30 =1mm~2mm。 4. A lithium-ion cylindrical battery as described in claim 1, characterized in that: L 20 =3.5mm~5.5mm,W 20 =1.6mm~3.4mm。 5. A lithium-ion cylindrical battery as described in claim 1, characterized in that: The first solder mark (201) includes a plurality of parallel and spaced positive electrode solder lines (2011), which are wavy or spiral in shape; The distance between the opposite sides of two adjacent positive electrode bonding wires (2011) is W. 101 The span of the positive electrode bonding wire (2011) along its width direction is W. 102 Among them, W 101 =0.3mm~0.5mm, W 102 = 0.4mm~0.6mm.

6. A lithium-ion cylindrical battery as described in claim 1, characterized in that: The line width of the second solder mark (202) is W. 301 Among them, W 301 =0.2mm~0.4mm.

7. A lithium-ion cylindrical battery as described in claim 5, characterized in that: The third solder mark (301) includes a plurality of parallel and spaced negative electrode solder lines (3011), which are wavy or spiral in shape; The spacing between two adjacent negative electrode bonding wires (3011) is W. 202 Among them, W 202 = 0.6mm~1.1mm.

8. A lithium-ion cylindrical battery as described in claim 7, characterized in that: The difference between the span of the negative electrode bonding wire (3011) along its width direction and its wire width is W. 201 The linewidth of the negative electrode bonding wire (3011) is W. 203 Among them, W 201 =0.15mm~0.35mm, W 203 = 0.1mm~0.3mm, and W 203 <W 201 .

9. A lithium-ion cylindrical battery as described in claim 7, characterized in that: The positive electrode bonding wire (2011), the negative electrode bonding wire (3011), and the second solder mark (202) each include multiple straight portions and multiple rounded corner portions, which are alternately and continuously arranged to form a wavy line shape; The angles between the straight portion of the positive electrode bonding wire (2011) and the two adjacent straight portions are A and B, respectively; the angles between the straight portion of the second solder mark (202) and the two adjacent straight portions are E and F, respectively; and the angles between the straight portion of the negative electrode bonding wire (3011) and the two adjacent straight portions are C and D, respectively, wherein A = 50°~75°, B = 50°~75°, C = 70°~120°, D = 70°~120°, E = 25°~65°, and F = 25°~65°.

10. A lithium-ion cylindrical battery according to any one of claims 1-9, characterized in that: The width of the tail body (22) is L 300 , where L 300 =5mm~7mm, R 10 = 8.5mm~9.6mm, R 20 = 8.5mm~10.5mm, R 30 =5.29mm~7.29mm.

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