A cylindrical lithium-ion battery

Abstract

This utility model relates to the field of cylindrical battery technology, and proposes a cylindrical lithium-ion battery, including a core, a lower end plate, a positive current collector, and a negative current collector. The core has a positive electrode tab and a negative electrode tab respectively at both ends. The positive current collector includes a disk body and a tail body; the radius of the disk body is R. 10 The span of the positive electrode solder mark along its length and width directions are L respectively. 10 and W 10 The radius of the negative current collector is R. 20 The span of the negative electrode solder mark along its length and width directions are L respectively. 20 and W 20 The radius of the lower end plate is R. 30 The span of the cap solder mark along its length and width directions are L respectively. 30 and W 30 , where L 10 / R 10 =42.9% - 56.0%, W 10 / R 10 =26.4% - 35.2%, L 20 / R 20 =37% - 57%, W 20 / R 20 =17%-36%, L 30 / R 30 =56%-76%, W 30 / R 30 =15%-32%. This utility model, by limiting the length and width of the positive electrode solder mark, negative electrode solder mark, and cap solder mark, can take into account the welding quality, structural strength, and current carrying capacity of the welding position, thereby effectively improving the overall performance of the battery.

Description

Technical Field

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

[0002] A cylindrical lithium-ion battery is a lithium-ion battery encapsulated in a cylindrical shell. It consists of components such as a positive electrode, a negative electrode, an electrolyte, a separator, and a shell. It stores and releases electrical energy by moving lithium ions between the positive and negative electrodes and has been widely used in consumer electronics, electric vehicles, and energy storage.

[0003] To reduce the internal resistance of a battery and improve its overall performance, a positive current collector is typically welded between the positive electrode tab and the cap assembly of the core, and a negative current collector is welded between the negative electrode tab and the outer casing to optimize the battery's current path and structural stability. For example, the invention patent CN114473210B discloses a current collector structure and welding method for a circular lithium-ion battery. To enable welding of the positive and negative current collectors to other components, welding areas are provided on both the positive and negative current collectors, allowing them to be welded to other components within these areas.

[0004] The area of ​​the welding region affects the overall performance of the battery. The aforementioned technical solutions do not adequately address the length and width of the welding region. If the welding region is too narrow, it will not only result in insufficient current carrying capacity at the welding point but also reduce the structural strength of the welding area. Furthermore, it can lead to heat concentration during welding, causing welding defects such as bursts. If the welding region is too wide, the welding point may deviate from the weldable area on the current collector, rendering some welds ineffective. This also affects the structural strength of the welding point and the overall performance of the battery. If the welding region is too narrow, the effective current carrying area at the welding point will be smaller, resulting in higher internal resistance, increased rate rise, and reduced structural strength. If the welding region is too long, the welding point may deviate from the weldable area on the current collector, causing the battery to be scrapped. This not only hinders welding efficiency but also increases battery manufacturing costs. Utility Model Content

[0005] In view of this, the present invention proposes a cylindrical lithium-ion battery. By simultaneously and reasonably setting the length and width of the positive electrode solder mark, negative electrode solder mark, and cap solder mark, the welding quality, structural strength, and current carrying capacity of the welding position can be taken into account, thereby effectively improving the overall performance of the battery.

[0006] The technical solution of this utility model is implemented as follows: This utility model provides a cylindrical lithium-ion battery, including a core, a lower end plate, a positive current collector, and a negative current collector. The core has positive and negative electrode tabs respectively at both ends. The positive current collector includes an integrally formed disc body and a tail body.

[0007] The disk body is fixed to the positive electrode tab by positive electrode soldering, the negative electrode current collector is fixed to the negative electrode tab by negative electrode soldering, and the tail body is fixed to the lower end plate by cap soldering.

[0008] The radius of the disk is R. 10 The span of the positive electrode solder mark along its length and width directions are L respectively. 10 and W 10 The radius of the negative current collector is R. 20 The span of the negative electrode solder mark along its length and width directions are L respectively. 20 and W 20 The radius of the lower end plate is R. 30 The span of the cap solder mark along its length and width directions are L respectively. 30 and W 30 , where L 10 / R 10 =42.9%-56%, W 10 / R 10 =26.4% - 35.2%, L 20 / R 20 =37%-57%, W 20 / R 20 =17%-36%, L 30 / R 30 =56%-76%, W 30 / R 30 =15%-32%.

[0009] Based on the above technical solutions, the preferred option is L. 10 =3.9mm-5.1mm, W 10 =2.4mm-3.2mm.

[0010] Further optimized, L 30 =3.5mm-4.5mm, W 30 =1mm-2mm.

[0011] Further optimized, L 20 =3.5mm-5.5mm, W 20 = 1.6mm - 3.4mm.

[0012] Based on the above technical solutions, preferably, the positive electrode solder mark is in the shape of a zigzag line;

[0013] The linewidth of the positive electrode solder mark is W0, and the turning angle of the positive electrode solder mark is A, where W0 = 0.2mm-0.4mm and A = 10°-30°.

[0014] Based on the above technical solutions, preferably, the cap solder mark is in the shape of a zigzag line;

[0015] The line width of the cap solder mark is W. 301 The turning angle of the cap solder mark is E, where W 301 =0.2mm-0.4mm, E=25°-65°.

[0016] Based on the above technical solutions, preferably, the negative electrode solder mark includes multiple negative electrode solder lines, the negative electrode solder lines are in the shape of zigzag lines, and the multiple negative electrode solder lines are arranged in parallel and at intervals;

[0017] The spacing between two adjacent negative electrode bonding wires is W 202 Among them, W 202 = 0.6mm-1.1mm.

[0018] More preferably, the linewidth of the negative electrode bonding wire is W. 203 The difference between the span of the negative electrode bonding wire along its width direction and the linewidth of the negative electrode bonding wire is W. 201 Among them, W 201 =0.15mm-0.35mm, W 203 = 0.1mm - 0.3mm, and W 203 <W 201 .

[0019] More preferably, the turning angle of the negative electrode welding wire is C, where C = 70°-120°.

[0020] Based on the above technical solutions, the preferred option is R. 10 = 8.8mm-9.4mm, R 20 = 8.5mm-10.5mm, R 30 = 5.29mm - 7.29mm;

[0021] The width of the tail body is W6, where W6 = 5mm - 7mm.

[0022] The cylindrical lithium-ion battery of this invention has the following advantages over the prior art:

[0023] (1) By limiting the length and width of the positive electrode solder mark, negative electrode solder mark and cap solder mark, the welding quality, structural strength and current carrying capacity of the welding position can be taken into account, thereby effectively improving the overall performance of the battery.

[0024] (2) By setting up zigzag positive electrode solder marks, negative electrode solder lines and cap solder marks, the welding length per unit area can be increased, thereby further ensuring the current carrying capacity of the welding position. Attached Figure Description

[0025] 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.

[0026] Figure 1 This is a top view of the disk portion of a cylindrical lithium-ion battery according to this utility model.

[0027] Figure 2 This is a top view of the positive electrode solder joint in a cylindrical lithium-ion battery according to the present invention.

[0028] Figure 3 This is a bottom view of the negative electrode current collector in a cylindrical lithium-ion battery according to this utility model.

[0029] Figure 4 This is a bottom view of the negative electrode solder joint in a cylindrical lithium-ion battery according to this utility model.

[0030] Figure 5 This is a front view of the lower end plate of a cylindrical lithium-ion battery according to the present invention.

[0031] Figure 6 This is a front view of the cap solder joint in a cylindrical lithium-ion battery according to the present invention.

[0032] Among them: 1. Positive electrode tab; 2. Negative electrode tab; 3. Lower end plate; 4. Disc body; 41. Positive electrode solder mark; 5. Negative electrode current collector; 51. Negative electrode solder mark; 511. Negative electrode welding wire; 6. Tail body; 61. Cap solder mark. Detailed Implementation

[0033] 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.

[0034] This utility model discloses a cylindrical lithium-ion battery, comprising a casing, a core, a cap assembly, a positive current collector, and a negative current collector.

[0035] The core is set inside the shell. The core includes a positive electrode material, a negative electrode material and a separator. Positive electrode tab 1 and negative electrode tab 2 are respectively provided at both ends of the core. Positive electrode tab 1 is connected to the positive electrode material and negative electrode tab 2 is connected to the negative electrode material.

[0036] The cap assembly is fixedly installed at the opening of the housing and is sealed and insulated from it. The conductor of the cap assembly on one side inside the housing is the lower end plate 3.

[0037] The positive electrode current collector includes a disc body 4 and a tail body 6. The disc body 4 is a disc-shaped structure, and the tail body 6 is a long strip-shaped structure. One end of the tail body 6 is integrally formed on the periphery of the disc body 4. The disc body 4 is welded and fixed to the positive electrode tab 1, and the tail body 6 is welded and fixed to the lower end plate 3, thereby realizing the conduction between the positive electrode material and the cap assembly.

[0038] Among them, the tail body 6 can be bent in order to realize the welding and assembly of the positive current collector.

[0039] The negative electrode current collector 5 is welded and fixed to the negative electrode tab 2 and the shell, so that the negative electrode of the core is connected to the shell.

[0040] The welding position between the disk body 4 and the positive electrode tab 1 is the positive electrode solder mark 41. The positive electrode solder mark 41 is a zigzag line with rounded corners in the curved area. Preferably, multiple positive electrode solder marks 41 are provided and arranged in a circular array around the center point of the disk body 4 to improve the welding firmness and welding stability between the disk body 4 and the positive electrode tab 1.

[0041] The welding position between the negative current collector 5 and the negative electrode tab 2 is the negative electrode solder mark 51. The negative electrode solder mark 51 includes multiple negative electrode welding lines 511, which are zigzag lines with rounded corners in their bending areas. The multiple negative electrode welding lines 511 are arranged parallel and spaced apart to enhance the current carrying capacity and fixing firmness of the negative electrode solder mark 51. Preferably, multiple negative electrode solder marks 51 are provided and arranged in a circumferential array around the center point of the negative current collector 5 to improve the welding firmness and stability between the negative current collector 5 and the negative electrode tab 2.

[0042] The welding position between the tail body 6 and the lower end plate 3 is a cap weld mark 61, which is a zigzag-shaped line with rounded corners in the curved area. Since the connection area between the tail body 6 and the lower end plate 3 is relatively small, only one cap weld mark 61 needs to be provided.

[0043] like Figure 1 and Figure 2 As shown, the radius of disk 4 is R. 10 The span of the positive electrode solder mark 41 along its length and width directions are L respectively. 10 and W 10 The line width of the positive electrode solder mark 41 is W0, and the angle between two adjacent broken lines in the positive electrode solder mark 41 is A, that is, the turning angle of the positive electrode solder mark 41 is A.

[0044] In some embodiments, L 10 / R 10 =42.9%-56%, meaning the span of the positive electrode solder mark 41 along its length is 42.9%, 49%, or 56% of the radius of the disk body 4, respectively. If L 10 / R 10 If L < 42.9%, then the span of the positive electrode solder mark 41 along its length is too small, resulting in a smaller current-carrying area at the soldering position. This leads to excessive internal resistance at the soldering position, which can easily cause problems such as concentrated heat generation and excessive rate-dependent temperature rise. Simultaneously, a small span of the positive electrode solder mark 41 along its length will also reduce the connection strength at the soldering position. If L 10 / R 10 If the ratio is greater than 56%, the span of the positive electrode solder mark 41 along its length is too large, and the welding position is prone to deviating from the weldable area on the disk 4, resulting in battery scrap. This not only hinders the improvement of welding efficiency but also increases the manufacturing cost of the battery.

[0045] In some embodiments, W 10 / R 10 =26.4%-35.2%, meaning the span of the positive electrode solder mark 41 along its width direction is 26.4%, 31%, or 35.2% of the radius of the disk body 4, respectively. If W 10 / R 10 If the width of the positive electrode solder mark 41 is less than 26.4%, the span along its width direction will be too small. This will not only shorten the effective length of the solder wire and reduce the current carrying capacity at the soldering position, but also make the soldering position prone to overheating, affecting the battery performance. Furthermore, it will reduce the connection strength at the soldering position. During the soldering process, excessive concentration of the solder wire at the soldering position can easily lead to soldering defects such as solder bursts due to concentrated heat. If W 10 / R 10If the positive electrode solder mark 41 has a span of too large along its width direction, the welding position is prone to interference with the through hole on the surface of the disk 4, resulting in some solder lines being invalid and the effective welding area being insufficient. This also affects the performance of the battery and reduces the connection strength at the welding point.

[0046] Furthermore, R 10 = 8.8mm-9.4mm, L 10 =3.9mm-5.1mm, W 10 =2.4mm-3.2mm, thus ensuring that the welding position takes into account welding strength, welding efficiency, overcurrent performance and overall battery performance.

[0047] In some embodiments, W0 = 0.2mm-0.4mm, meaning the linewidth of the positive electrode solder mark 41 is 0.2mm, 0.3mm, or 0.4mm, etc. If W0 < 0.2mm, the linewidth of the positive electrode solder mark 41 is too small, resulting in weakened current carrying capacity at the soldering position, increased internal resistance of the battery, and increased temperature rise at the solder line, affecting battery performance. If W0 > 0.4mm, the linewidth of the positive electrode solder mark 41 is too large, resulting in insufficient spacing between adjacent folds in the solder line. During the soldering process, welding defects such as solder bursts are prone to occur due to heat concentration, affecting the welding strength and current carrying capacity at the soldering position.

[0048] In some embodiments, A = 10°-30°, meaning the turning angle of the positive electrode solder mark 41 is 10°, 20°, or 30°, etc. If A < 10°, the turning angle of the positive electrode solder mark 41 is too small, resulting in an insufficient distance between two adjacent broken lines in the solder line. During the soldering process, welding defects such as solder bursts are prone to occur due to heat concentration, affecting the welding strength and current carrying capacity of the soldering position. If A > 30°, the turning angle of the positive electrode solder mark 41 is too large. Within the same welding span, the length of the solder line will be shortened, resulting in a weakened current carrying capacity at the soldering position and an increased current temperature rise at the soldering position, affecting the battery performance.

[0049] like Figure 3 and Figure 4 As shown, the radius of the negative current collector 5 is R. 20 The span of the negative electrode solder mark 51 along its length and width directions are L respectively. 20 and W 20 The spacing between two adjacent negative electrode bonding wires 511 is W. 202 The linewidth of the negative electrode bonding wire 511 is W. 203 The difference between the span of the negative electrode bonding wire 511 along its width direction and the linewidth of the negative electrode bonding wire 511 is W. 201 The turning angle of the negative electrode bonding wire 511 is C.

[0050] In some embodiments, L 20 / R 20=37%-57%, meaning the span of the negative electrode solder mark 51 along its length is 37%, 47%, or 57% of the radius of the negative electrode current collector 5, etc. If L 20 / R 20 If the span is less than 37%, the negative electrode solder mark 51 has too small a span along its length, which weakens the current carrying capacity at the soldering point, leading to increased temperature rise at the soldering point and affecting battery performance. If L 20 / R 20 If the percentage is greater than 57%, then the span of the negative electrode solder mark 51 along its length is too large. This will not improve the battery's internal resistance, but it will increase the risk of soldering failure rate and reduce soldering reliability.

[0051] In some embodiments, W 20 / R 20 =17%-36%, meaning the span of the negative electrode solder mark 51 along its width direction is 17%, 27%, or 36% of the radius of the negative electrode current collector 5, etc. If W 20 / R 20 If the weld density is less than 17%, the span of the negative electrode solder mark 51 along its width direction is too small, and the two adjacent negative electrode solder lines 511 are too concentrated. During the welding process, welding defects such as burn-through and blasting are prone to occur due to heat accumulation, leading to an increase in the welding defect rate. If W 20 / R 20 If the span is greater than 36%, the span of the negative electrode solder mark 51 along its width direction is too large, and the spacing between two adjacent negative electrode solder lines 511 is too large. During the welding process, this leads to an increase in the stroke of the welding laser head, resulting in a decrease in welding efficiency.

[0052] Furthermore, R 20 = 8.5mm-10.5mm, L 20 =3.5mm-5.5mm, W 20 =1.6mm-3.4mm, thus ensuring that the welding position takes into account welding strength, welding efficiency, overcurrent performance and overall battery performance.

[0053] In some embodiments, W 202 =0.6mm-1.1mm, meaning the spacing between two adjacent negative electrode bonding wires 511 is 0.6mm, 0.8mm, or 1.1mm, etc. If W 202 If the distance between two adjacent negative electrode welding wires 511 is less than 0.6mm, the spacing between them is too small, and they are too concentrated. During welding, heat accumulation can easily lead to welding defects such as burn-through and spalling, resulting in an increased welding failure rate. If W 202 If the distance is greater than 1.1mm, the spacing between two adjacent negative electrode welding wires 511 is too large, which will increase the stroke of the welding laser head during the welding process and reduce the welding efficiency.

[0054] In some embodiments, W 203=0.1mm-0.3mm, meaning the linewidth of the negative electrode bonding wire 511 is 0.1mm, 0.2mm, or 0.3mm, etc. If W 203 If the width is less than 0.1mm, the negative electrode bonding wire 511 is too small, resulting in weakened current carrying capacity at the bonding position, increased internal resistance of the battery, and increased temperature rise at the bonding wire, thus affecting battery performance. If W 203 If the width is greater than 0.3mm, the line width of the negative electrode bonding wire 511 is too large, which does not have a better effect on optimizing the internal resistance of the battery. However, the increased welding area will make it easier for welding defects to occur and reduce welding reliability.

[0055] In some embodiments, W 201 = 0.15mm - 0.35mm, and W 203 <W 201 That is, the difference between the span of the negative electrode bonding wire 511 along its width direction and the line width of the negative electrode bonding wire 511 is 0.15mm, 0.25mm, or 0.35mm, etc. If W 201 If the distance is less than 0.15mm, the distance between two adjacent negative electrode welding wires 511 is too close. During the welding process, heat accumulation can easily lead to welding defects such as burn-through and spalling, resulting in an increased welding failure rate. If W 201 If the distance is greater than 0.35mm, the spacing between two adjacent negative electrode welding wires 511 is too large, which will increase the stroke of the welding laser head during the welding process and reduce the welding efficiency.

[0056] In some embodiments, C = 70°-120°, meaning the turning angle of the negative electrode bonding wire 511 is 70°, 95°, or 120°, etc. If C < 70°, the turning angle of the negative electrode bonding wire 511 is too small, resulting in an insufficient distance between two adjacent bends in the bonding wire. During the welding process, welding defects such as welding bursts are easily caused by heat concentration, affecting the welding strength and current carrying capacity of the welding position. The bonding wire needs to meet a certain weldable length to ensure that the actual welding area is sufficient. If C > 120°, the turning angle of the negative electrode bonding wire 511 is too large, resulting in an excessively large welding area required within a certain welding length. This causes the welding area to exceed the negative electrode current collector 5, causing some bonding wires to fail, resulting in weakened current carrying capacity at the welding position, increased current temperature rise, and affecting battery performance.

[0057] like Figure 1 , Figure 5 and Figure 6 As shown, the radius of the lower end plate 3 is R. 30 The width of the tail body 6 is W6, and the span of the cap weld mark 61 along its length and width directions are L respectively. 30 and W 30 The line width of the cap solder mark 61 is W. 301 The turning angle of the cap solder mark 61 is E.

[0058] In some embodiments, L 30 / R 30 =56%-76%, meaning the span of the cap weld mark 61 along its length is 56%, 66%, or 76% of the radius of the lower end plate 3, etc. If L 30 / R 30 If the span of the cap solder mark 61 along its length is less than 56%, the current flow area at the welding position will be smaller, resulting in excessive internal resistance at the welding position. This can easily lead to problems such as concentrated heat generation and excessive rate-dependent temperature rise. Simultaneously, the smaller span of the positive electrode solder mark 41 along its length will also reduce the connection strength at the welding position. If L 30 / R 30 If the weld mark is greater than 76%, the span of the cap weld mark 61 along its length is too large, and the welding position is likely to deviate from the weldable area on the tail body 6, resulting in battery scrap. This not only hinders the improvement of welding efficiency but also increases the manufacturing cost of the battery.

[0059] In some embodiments, W 30 / R 30 =15%-32%, meaning the span of the cap solder mark 61 along its width direction is 15%, 24%, or 32% of the radius of the lower end plate 3, etc. If W 30 / R 30 If the span of the cap solder mark 61 is less than 15%, the effective area of ​​the solder joint is reduced, the current carrying capacity is weakened, the temperature rise at the solder joint is increased, and the battery performance is affected. If W 30 / R 30 If the span of the cap solder mark 61 is greater than 32%, then the span along its width direction is too large. This will not improve the internal resistance of the battery, but it will increase the soldering time, leading to a decrease in soldering efficiency and an increase in the soldering defect rate.

[0060] Furthermore, R 30 =5.29mm-7.29mm, W6=5mm-7mm, L 30 =3.5mm-4.5mm, W 30 =1mm-2mm, thus ensuring that the welding position takes into account welding strength, welding efficiency, overcurrent performance and the overall performance of the battery.

[0061] In some embodiments, W 301 =0.2mm-0.4mm, meaning the line width of the cap solder mark 61 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 cap solder mark 61 is too small, resulting in insufficient effective welding area at the welding position, weakened current carrying capacity, increased temperature rise at the solder line, and negatively impacting battery performance. It also leads to an increase in the battery's internal resistance. If W 301If the line width is greater than 0.4mm, the line width of the cap solder mark 61 is too large. This will not only affect the appearance of the solder line, but also cause the spacing between two adjacent broken lines in the solder line to be too small. During the soldering process, welding defects such as soldering bursts are likely to occur due to heat concentration, leading to an increase in the soldering defect rate.

[0062] In some embodiments, E = 25°-65°, meaning the turning angle of the cap solder mark 61 is 25°, 45°, or 65°, etc. If E < 25°, the turning angle of the cap solder mark 61 is too small, and the distance between two adjacent broken lines in the solder line is too small. During the soldering process, welding defects such as solder bursts are easily caused by heat concentration, leading to an increased soldering failure rate. If E > 65°, the turning angle of the cap solder mark 61 is too large. To achieve the required soldering area, the total length of the cap solder mark 61 needs to be increased, causing the cap solder mark 61 to easily deviate from the tail body 6, reducing the effective soldering area, weakening the current carrying capacity at the soldering position, and affecting the battery performance.

[0063] 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 cylindrical lithium-ion battery, characterized in that: It includes a core, a lower end plate (3), a positive current collector plate, and a negative current collector plate (5). The core has a positive electrode tab (1) and a negative electrode tab (2) at both ends. The positive current collector plate includes an integrally formed plate body (4) and a tail body (6). The disk body (4) is welded and fixed to the positive electrode tab (1) by positive electrode solder stamp (41), the negative electrode current collector (5) is welded and fixed to the negative electrode tab (2) by negative electrode solder stamp (51), and the tail body (6) is welded and fixed to the lower end plate (3) by cap solder stamp (61). The radius of the disk (4) is R. 10 The span of the positive electrode solder mark (41) along its length and width directions are L respectively. 10 and W 10 The radius of the negative current collector (5) is R. 20 The span of the negative electrode solder mark (51) along its length and width directions are L respectively. 20 and W 20 The radius of the lower end plate (3) is R. 30 The span of the cap solder mark (61) along its length and width directions are L respectively. 30 and W 30 , where L 10 / R 10 =42.9%-56%, W 10 / R 10 =26.4% - 35.2%, L 20 / R 20 =37%-57%, W 20 / R 20 =17%-36%, L 30 / R 30 =56%-76%, W 30 / R 30 =15%-32%.

2. A cylindrical lithium-ion battery as described in claim 1, characterized in that: L 10 =3.9mm-5.1mm,W 10 =2.4mm-3.2mm。 3. A cylindrical lithium-ion battery as described in claim 2, characterized in that: L 30 =3.5mm-4.5mm,W 30 =1mm-2mm。 4. A cylindrical lithium-ion battery as described in claim 3, characterized in that: L 20 =3.5mm-5.5mm,W 20 =1.6mm-3.4mm。 5. A cylindrical lithium-ion battery as described in claim 1, characterized in that: The positive electrode solder mark (41) is in the shape of a broken line; The line width of the positive electrode solder mark (41) is W0, and the turning angle of the positive electrode solder mark (41) is A, where W0 = 0.2mm-0.4mm and A = 10°-30°.

6. A cylindrical lithium-ion battery as described in claim 1, characterized in that: The cap solder mark (61) is in the shape of a zigzag line; The line width of the cap solder mark (61) is W. 301 The turning angle of the cap solder mark (61) is E, where W 301 =0.2mm-0.4mm, E=25°-65°.

7. A cylindrical lithium-ion battery as described in claim 1, characterized in that: The negative electrode solder mark (51) includes a plurality of negative electrode solder lines (511), the negative electrode solder lines (511) are in the shape of a broken line, and the plurality of negative electrode solder lines (511) are arranged in parallel and at intervals; The spacing between two adjacent negative electrode bonding wires (511) is W. 202 Among them, W 202 = 0.6mm-1.1mm.

8. A cylindrical lithium-ion battery as described in claim 7, characterized in that: The linewidth of the negative electrode bonding wire (511) is W. 203 The difference between the span of the negative electrode bonding wire (511) along its width direction and the linewidth of the negative electrode bonding wire (511) is W. 201 Among them, W 201 =0.15mm-0.35mm, W 203 = 0.1mm - 0.3mm, and W 203 <W 201 .

9. A cylindrical lithium-ion battery as described in claim 8, characterized in that: The turning angle of the negative electrode bonding wire (511) is C, where C = 70°-120°.

10. A cylindrical lithium-ion battery as described in any one of claims 1-9, characterized in that: R 10 =8.8mm-9.4mm,R 20 =8.5mm-10.5mm,R 30 =5.29mm-7.29mm; The width of the tail body (6) is W6, where W6 = 5mm-7mm.

Images