Lithium-ion cylindrical battery
By limiting the welding dimensions between the positive electrode current collector and the tab, and between the tail body and the lower end plate of the lithium-ion cylindrical battery, the problem of poor welding was solved, a low-resistance path and enhanced strength were achieved, and the battery performance and stability were improved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- JIANGSU RELIANCE ENERGY TECHNOLOGY CO LTD
- Filing Date
- 2025-07-11
- Publication Date
- 2026-07-07
AI Technical Summary
In the existing technology, the welding dimensions between the positive electrode current collector and the tab, and between the tail body and the lower end plate of the lithium-ion cylindrical battery are not fully defined, resulting in poor welding effect and affecting battery performance.
By defining the dimensions of the first solder mark between the positive current collector and the tab, and the second solder mark between the tail and the lower end plate, the welding area and strength are ensured, including defining the length, width, and included angle of the solder marks, to form a low-resistance path and enhance the connection strength.
It improves the welding effect of lithium-ion cylindrical batteries, reduces the internal resistance of current, enhances the connection strength, avoids problems such as welding bursts, and improves the overall performance and stability of the battery.
Smart Images
Figure CN224472642U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of battery technology, and in particular relates to a lithium-ion cylindrical battery. Background Technology
[0002] The positive electrode current collector of a cylindrical lithium battery typically consists of two parts: the plate body and the tail body. The plate body is welded to the flattened full tab of the core, and the tail body is welded to the lower end plate of the cap.
[0003] The size of the solder mark between the plate and the tab affects the welding effect. Patent CN219717197U discloses a cylindrical battery and an electrical device containing the cylindrical battery. By limiting the distribution area of the solder mark on the radius of the positive current collector, the welding size and welding area between the positive current collector and the tab are defined, thereby improving the stability of the welding connection between the tab and the positive current collector and the battery's current carrying capacity.
[0004] Although patent CN219717197U specifies the welding dimensions and welding area between the positive current collector and the electrode tab, the specifications are not comprehensive enough and still cannot guarantee the welding effect between the plate and the electrode tab.
[0005] Similarly, limiting the weld mark size between the tail section and the lower end plate can ensure the welding effect between the tail section and the lower end plate.
[0006] In view of the above, this application is hereby submitted. Utility Model Content
[0007] To address the shortcomings of related technologies, this utility model provides a lithium-ion cylindrical battery. By limiting the welding dimensions between the positive current collector and the tab, as well as the welding dimensions between the tail and the lower end plate, the connection effect between the positive current collector and the tab and the lower end plate is ensured, thereby guaranteeing the performance of the lithium-ion cylindrical battery.
[0008] This utility model provides a lithium-ion cylindrical battery, including a core and a positive current collector. The core is provided with a tab, and the positive current collector includes a disk body and a tail body. The disk body is welded to the tab, and the tail body is welded to the lower end plate of the cap. The disk body and the tab are welded together to form a first weld mark, and the tail body and the lower end plate are welded together to form a second weld mark.
[0009] The ratio of the length L10 of the first solder mark to the radius R10 of the disk body is greater than or equal to 42.9% and less than or equal to 56.0%.
[0010] The ratio of the width W10 of the first solder mark to the radius R10 of the disk body is greater than or equal to 26.4% and less than or equal to 35.2%;
[0011] The ratio of the length L30 of the second solder mark to the radius R30 of the lower end plate is greater than or equal to 56% and less than or equal to 76%.
[0012] The ratio of the width W30 of the second solder mark to the radius R30 of the lower end plate is greater than or equal to 15% and less than or equal to 32%.
[0013] In some embodiments, the length L10 of the first solder mark is greater than or equal to 3.9 mm and less than or equal to 5.1 mm;
[0014] The width W10 of the first solder mark is greater than or equal to 2.4 mm and less than or equal to 3.2 mm.
[0015] In some embodiments, the length L30 of the second solder mark is greater than or equal to 3.5 mm and less than or equal to 4.5 mm;
[0016] The width W30 of the second solder mark is greater than or equal to 1 mm and less than or equal to 2 mm.
[0017] In some embodiments, the first solder mark includes a first solder line, the width of which is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.
[0018] In some embodiments, the first bonding wire is wavy, and the included angle formed by the first bonding wire at the crest of the wave is denoted as included angle A, which is greater than or equal to 10° and less than or equal to 30°; the included angle formed by the first bonding wire at the trough of the wave is denoted as included angle B, which is greater than or equal to 10° and less than or equal to 30°.
[0019] In some embodiments, the second solder mark includes a second solder line, the width of which, W301, is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.
[0020] In some embodiments, the second bonding wire is wavy, and the included angle formed by the second bonding wire at the crest of the wave is denoted as included angle E, which is greater than or equal to 25° and less than or equal to 65°; the included angle formed by the second bonding wire at the trough of the wave is denoted as included angle F, which is greater than or equal to 25° and less than or equal to 65°.
[0021] In some embodiments, the ratio of the length L30 of the second solder mark to the width L300 of the tail body is greater than or equal to 56% and less than or equal to 76%.
[0022] And / or, the width L300 of the tail body is greater than or equal to 5 mm and less than or equal to 7 mm.
[0023] In some embodiments, the lower end plate includes a boss and vents, the boss being located in the middle portion of the lower end plate, and multiple vents being arranged around the outer periphery of the boss; a second solder mark is located between the boss and the vents.
[0024] And / or, the radius R30 of the lower end plate is greater than or equal to 5.29 mm and less than or equal to 7.29 mm.
[0025] In some embodiments, the disc body further includes a central hole and peripheral holes. The central hole is located in the middle part of the disc body, and multiple peripheral holes are provided, which surround the outer periphery of the central hole. The ratio of the radius R10 of the disc body to the radius R100 of the winding core is greater than or equal to 86.4% and less than or equal to 92.3%.
[0026] And / or, the radius R10 of the disk body is greater than or equal to 8.8 mm and less than or equal to 9.4 mm;
[0027] And / or, the radius R100 of the core is greater than or equal to 9.18 mm and less than or equal to 11.18 mm.
[0028] Based on the above technical solution, in this embodiment of the utility model, the lithium-ion cylindrical battery effectively improves the overall performance of the battery by limiting the relevant dimensions of the first and second solder marks. Attached Figure Description
[0029] The accompanying drawings, which are included to provide a further understanding of the present invention and form part of this application, illustrate exemplary embodiments of the present invention and, together with the description thereof, serve to explain the present invention and do not constitute an undue limitation thereof. In the drawings:
[0030] Figure 1 This is a schematic diagram of the structure of one embodiment of the lithium-ion cylindrical battery of this utility model;
[0031] Figure 2 This is a schematic diagram of the positive electrode current collector in one embodiment of the lithium-ion cylindrical battery of this utility model;
[0032] Figure 3 This is a schematic diagram of the structure of the positive electrode current collector and the winding core during welding in one embodiment of the lithium-ion cylindrical battery of this utility model;
[0033] Figure 4 for Figure 3 Enlarged view of a portion of point A in the middle;
[0034] Figure 5 This is a schematic diagram of the structure of the tail body and the lower end plate being welded in one embodiment of the lithium-ion cylindrical battery of this utility model;
[0035] Figure 6 for Figure 5 Enlarged view of a section at point B in the middle;
[0036] Figure 7 This is a dimensional diagram of the second solder mark and the second solder line in one embodiment of the lithium-ion cylindrical battery of this utility model.
[0037] In the picture:
[0038] 1. Lower end plate; 2. Positive current collector; 3. Housing; 4. Core;
[0039] 11. Pores; 12. Bosses;
[0040] 21. Disc body; 22. Tail body;
[0041] 201, First solder mark; 202, Second solder mark;
[0042] 210, First bonding wire; 220, Second bonding wire;
[0043] 211. Center hole; 212. Outer hole. Detailed Implementation
[0044] The technical solutions in the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this utility model, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this utility model without creative effort are within the scope of protection of this utility model.
[0045] In the description of this utility model, it should be understood that the terms "center", "lateral", "longitudinal", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0046] The terms "first," "second," and "third" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first," "second," or "third" may explicitly or implicitly include one or more of that feature.
[0047] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0048] As attached Figure 1 As shown in an illustrative embodiment of the lithium-ion cylindrical battery of this utility model, the lithium-ion cylindrical battery includes a housing 3 and a core 4. The core 4 is disposed inside the housing 3 and has tabs on it. The core 4 is the main body for energy storage of the battery, and the tabs are necessary components for the current to be discharged from the inside of the core 4. The two are connected by welding process to form a conductive connection, which together constitutes the core electrical performance structure of the battery.
[0049] like Figure 1 and Figure 2 As shown, the lithium-ion cylindrical battery also includes a positive electrode current collector 2, which includes a disk body 21 and a tail body 22. The disk body 21 and the tail body 22 are connected to each other, and the disk body 21 is welded to the electrode tab, and the tail body 22 is welded to the lower end plate 1 of the cap, so that the positive electrode current collector 2 is connected to the core 4 and the cap.
[0050] In some embodiments, the disc body 21 and the tail body 22 are integrally formed and are located on the same metal plate.
[0051] like Figure 3 As shown, the disc body 21 is welded to the electrode tab to form a first weld mark 201, which is located on the side of the disc body 21 away from the winding core 4.
[0052] It should be noted that when current is transferred from the tab to the disk 21 through the first solder mark 201, sufficient contact area is required to ensure a low-resistance path. The actual metal contact area in the first solder mark 201 that participates in current transmission affects the internal resistance of the current and also affects the connection strength between the disk 21 and the tab. In this embodiment, the actual metal contact area in the solder mark that participates in current transmission is referred to as the effective current-carrying area.
[0053] like Figure 4 As shown, the first solder mark 201 includes a first solder line 210, which is wavy. In some embodiments, the length of the first solder mark 201 refers to the straight-line distance between the two ends of the first solder line 210, and the width of the first solder mark 201 refers to the maximum dimension of the first solder line 210 from crest to trough or to the end along the crest to trough direction.
[0054] The first solder line 210 includes several solder line segments, which are arranged along a wavy curve to make the first solder line 210 wavy. The length of the first solder line 210 usually refers to the total length of the solder line segments; therefore, the length of the first solder line 210 is usually greater than the length of the first solder mark 201.
[0055] like Figure 4 As shown, the width W0 of the first bonding line 210 is greater than or equal to 0.2 mm and less than or equal to 0.4 mm, preferably 0.3 mm.
[0056] If the width W0 of the first solder line 210 is too small, the current carrying capacity of the first solder mark 201 will be weakened, the internal resistance of the battery will increase, the overcurrent temperature rise at the first solder line 210 will increase, and the performance of the battery will be affected.
[0057] If the width W0 of the first weld line 210 is too large, the distance between adjacent weld line segments will be too close, and the heat will be concentrated, which will lead to problems such as welding bursts, affecting the strength of the weld and the current carrying capacity.
[0058] like Figure 4 As shown, the included angle formed by the first bonding line 210 at the crest is denoted as included angle A. Included angle A is greater than or equal to 10° and less than or equal to 30°, and included angle A is preferably 18°.
[0059] If the included angle A is too small, the arrangement of several welding segments on the first welding line 210 will be too concentrated, resulting in heat concentration, which may lead to welding bursts and other problems, affecting the connection strength between the disc 21 and the tab and the current carrying capacity of the first solder mark 201.
[0060] If the included angle A is too large, the length of the first solder mark 201 will be shortened while the length of the first solder line 210 remains unchanged. This will weaken the effective current carrying capacity of the first solder mark 201 and increase the current temperature rise at the first solder line 210, thus affecting the performance of the battery.
[0061] The included angle formed by the first weld line 210 at the trough is denoted as included angle B. Included angle B is greater than or equal to 10° and less than or equal to 30°, and included angle B is preferably 18°.
[0062] If the included angle B is too small, the arrangement of several welding segments on the first welding line 210 will be too concentrated, resulting in heat concentration, which may lead to welding bursts and other problems, affecting the connection strength between the disc 21 and the tab and the current carrying capacity of the first solder mark 201.
[0063] If the included angle B is too large, the length of the first solder mark 201 will be shortened while the length of the first solder line 210 remains unchanged. This will weaken the effective current carrying capacity of the first solder mark 201 and increase the current temperature rise at the first solder line 210, thus affecting the performance of the battery.
[0064] The ratio of the length L10 of the first solder mark 201 to the radius R10 of the disk body 21 is greater than or equal to 42.9% and less than or equal to 56.0%.
[0065] If the ratio of the length L10 of the first solder mark 201 to the radius R10 of the disk body 21 is too small, the actual metal contact area participating in current transmission in the first solder mark 201 will be smaller, resulting in a larger internal resistance of the current. This may cause the heating to be concentrated at the welding point between the disk body 21 and the electrode, resulting in an excessively large multiplier temperature rise, and may also cause insufficient welding strength between the disk body 21 and the electrode.
[0066] If the ratio of the length L10 of the first solder mark 201 to the radius R10 of the disc 21 is too large, the disc 21 will easily deviate from the weldable area on the disc 21 when welding with the electrode, resulting in battery scrap. It will also increase the welding time between the disc 21 and the electrode, reduce welding efficiency, and increase the manufacturing cost of the battery.
[0067] In some embodiments, the length L10 of the first solder mark 201 is greater than or equal to 3.9 mm and less than or equal to 5.1 mm, preferably 4.5 mm.
[0068] If the length L10 of the first solder mark 201 is too small, the actual metal contact area involved in current transmission in the first solder mark 201 will be smaller, resulting in a larger internal resistance of the current. This may cause the heating to be concentrated at the welding point between the disc 21 and the electrode, resulting in an excessively large rate temperature rise. It may also cause insufficient welding strength between the disc 21 and the electrode.
[0069] If the length L10 of the first solder mark 201 is too large, the disk 21 will easily deviate from the weldable area on the disk 21 when welding with the electrode, resulting in battery scrap. It will also increase the welding time between the disk 21 and the electrode, reduce welding efficiency, and increase the manufacturing cost of the battery.
[0070] The ratio of the width W10 of the first solder mark 201 to the radius R10 of the disk body 21 is greater than or equal to 26.4% and less than or equal to 35.2%.
[0071] If the ratio of the width W10 of the first solder mark 201 to the radius R10 of the disk 21 is too small, the effective length of the first solder line 210 will be shortened, resulting in insufficient current carrying capacity, heat generation at the solder joint between the disk 21 and the electrode, affecting the performance of the battery, and also causing the first solder line 210 to be too concentrated, leading to problems such as solder burst points, which may result in insufficient solder strength between the disk 21 and the electrode.
[0072] If the ratio of the width W10 of the first solder mark 201 to the radius R10 of the disk body 21 is too large, the first solder line 210 is easily soldered into the outer hole 212, causing a part of the first solder line 210 to be ineffective, resulting in insufficient effective welding area between the disk body 21 and the electrode tab, and the first solder line 210 is prone to heat generation, affecting the performance of the battery, and may also cause insufficient welding strength between the disk body 21 and the electrode tab.
[0073] In some embodiments, the width W10 of the first solder mark 201 is greater than or equal to 2.4 mm and less than or equal to 3.2 mm, preferably 2.8 mm.
[0074] If the width W10 of the first solder mark 201 is too small, the effective length of the first solder line 210 will be shortened, resulting in insufficient current carrying capacity, heat generation at the welding point between the disc 21 and the electrode, affecting the performance of the battery, and also causing the first solder line 210 to be too concentrated, leading to problems such as welding burst points, which may result in insufficient welding strength between the disc 21 and the electrode.
[0075] If the width W10 of the first solder mark 201 is too large, the first solder line 210 is easily soldered into the outer hole 212, causing part of the first solder line 210 to be ineffective, resulting in insufficient effective welding area between the disc body 21 and the electrode tab, and the first solder line 210 is prone to heat generation, affecting the performance of the battery, and may also cause insufficient welding strength between the disc body 21 and the electrode tab.
[0076] In some embodiments, the radius R10 of the disk body 21 is greater than or equal to 8.8 mm and less than or equal to 9.4 mm, preferably 9 mm.
[0077] When the radius R10 of the disk body 21 is 9mm, the length L10 of the first solder mark 201 is 4.5mm, and the width W10 of the first solder mark 201 is 2.8mm, the ratio of the length L10 of the first solder mark 201 to the radius R10 of the disk body 21 is 50%, and the ratio of the width W10 of the first solder mark 201 to the radius R10 of the disk body 21 is 31.1%.
[0078] In some embodiments, such as Figure 2 As shown, the disk body 21 also includes a central hole 211 and peripheral holes 212. The central hole 211 is located in the middle part of the disk body 21, and multiple peripheral holes 212 are provided, with multiple peripheral holes 212 surrounding the outer periphery of the central hole 211.
[0079] The ratio of the radius R10 of the disc body 21 to the radius R100 of the core 4 is greater than or equal to 86.4% and less than or equal to 92.3%.
[0080] If the ratio of the radius R10 of the disc 21 to the radius R100 of the core 4 is too large, the diameter of the disc 21 will be close to the diameter of the core 4. When the core 4 is installed into the battery, the opening of the casing 3 is usually sealed by mechanical sealing with a grooving. During grooving and mechanical sealing, the casing wall of the casing 3 below the groove will deform towards the center of the axis. If the positive current collector 2 is welded to the core 4 and the insulation of the positive current collector 2 is poor, the inner wall of the casing 3 at this point is likely to come into contact with the edge of the positive current collector 2, increasing the risk of short circuit.
[0081] If the ratio of the radius R10 of the disc 21 to the radius R100 of the core 4 is too small, the diameter of the disc 21 will become smaller, the weldable area of the disc 21 and the core 4 will become smaller, the current carrying capacity of the corresponding welding wire will be weakened, the temperature rise at the welding wire will increase, and the performance of the battery will be affected.
[0082] The radius R100 of the core 4 is greater than or equal to 9.18 mm and less than or equal to 11.18 mm, preferably 10 mm. When the radius R100 of the core 4 is 10 mm and the radius R10 of the disc 21 is 9 mm, the ratio of the radius R10 of the disc 21 to the radius R100 of the core 4 is 90%.
[0083] like Figure 5 and Figure 6 As shown, the tail body 22 is welded to the lower end plate 1 to form a second weld mark 202, which is located on the side of the tail body 22 away from the lower end plate 1.
[0084] Similarly, when current is transmitted from tail body 22 to lower end plate 1 through second solder mark 202, sufficient contact area is required to ensure a low resistance path. The actual metal contact area in second solder mark 202 that participates in current transmission will affect the internal resistance of the current and will also affect the connection strength between tail body 22 and lower end plate 1.
[0085] like Figure 7 As shown, the second solder mark 202 includes a second solder line 220, which is wavy. In some embodiments, the length of the second solder mark 202 refers to the straight-line distance between the two ends of the second solder line 220, and the width of the second solder mark 202 refers to the maximum dimension of the second solder line 220 from crest to trough or to the end along the crest to trough direction.
[0086] Similarly, the second solder line 220 includes several solder line segments, which are arranged along a wavy curve to make the second solder line 220 wavy. The length of the second solder line 220 usually refers to the total length of the solder line segments; therefore, the length of the second solder line 220 is usually greater than the length of the second solder mark 202.
[0087] The width W301 of the second bonding line 220 is greater than or equal to 0.2 mm and less than or equal to 0.4 mm, preferably 0.3 mm.
[0088] If the width W301 of the second welding line 220 is too small, the effective welding area between the tail body 22 and the lower end plate 1 will be small, the current carrying capacity will be weakened, the temperature at the second welding line 220 will rise, affecting the performance of the battery, and because the width of a single second welding line 220 is too small, it is easy to cause the internal resistance of the battery to rise.
[0089] If the width W301 of the second weld line 220 is too large, it will not only affect the appearance, but also cause the energy of the second weld line 220 to concentrate at the turning point, which is prone to explosion, changes in the color of the weld line, etc., and will increase the failure rate of welding.
[0090] like Figure 7As shown, the included angle formed by the second bonding line 220 at the crest is denoted as included angle E, which is greater than or equal to 25° and less than or equal to 65°.
[0091] If the included angle E is too small, the arrangement of several welding segments on the second welding line 220 will be too concentrated, resulting in the concentration of energy and heat in the second welding line 220. This can lead to the appearance of explosion points at the second welding line 220, color changes in the second welding line 220, and an increase in the welding defect rate.
[0092] If the included angle E is too large, the length of the second solder mark 202 will increase while the total length of the second solder line 220 remains unchanged. Due to the process deviation of the second solder line 220 itself, the increased straight-line distance between the beginning and end of the second solder line 220 in the lateral direction will make it easier to approach the two sides of the positive current collector 2. Due to the reasonable process deviation, the second solder line 220 is easy to be soldered outside the positive current collector 2, resulting in a reduction in the effective welding area, a weakening of the welding current carrying capacity, and an increase in temperature at the second solder line 220, which will affect the performance of the battery.
[0093] like Figure 7 As shown, the included angle formed by the second weld line 220 at the trough is denoted as included angle F, which is greater than or equal to 25° and less than or equal to 65°.
[0094] If the included angle F is too small, the arrangement of several welding segments on the second welding line 220 will be too concentrated, resulting in the concentration of energy and heat in the second welding line 220. This will cause the second welding line 220 to be prone to explosion points, color changes, and an increase in the welding defect rate.
[0095] If the included angle F is too large, the length of the second solder mark 202 will increase while the total length of the second solder line 220 remains unchanged. Due to the process deviation of the second solder line 220 itself, the increased straight-line distance between the beginning and end of the second solder line 220 in the lateral direction will make it easier to approach the two sides of the positive electrode current collector 2. Due to the reasonable process deviation, the second solder line 220 is easy to be soldered outside the positive electrode current collector 2, resulting in a reduction in the effective welding area, a weakening of the welding current carrying capacity, and an increase in temperature at the second solder line 220, which will affect the performance of the battery.
[0096] The ratio of the length L30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is greater than or equal to 56% and less than or equal to 76%.
[0097] If the ratio of the length L30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is too small, the second solder line 220 will be too short, the effective welding area will be reduced, the current carrying capacity of the second solder line 220 will be weakened, and the temperature at the second solder line 220 will rise, affecting the performance of the battery.
[0098] If the ratio of the length L30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is too large, the second solder line 220 will become longer. This will not only fail to improve the internal resistance of the battery, but also increase the welding time between the tail body 22 and the lower end plate 1, reduce welding efficiency, and increase the risk of welding defects, thus increasing the welding defect rate.
[0099] In some embodiments, the length L30 of the second solder mark 202 is greater than or equal to 3.5 mm and less than or equal to 4.5 mm, preferably 4 mm.
[0100] If the length L30 of the second solder mark 202 is too small, the second solder line 220 will be too short, the effective welding area will be reduced, the current carrying capacity of the second solder line 220 will be weakened, the temperature at the second solder line 220 will rise, and the battery performance will be affected.
[0101] If the length L30 of the second solder mark 202 is too large, the second solder line 220 will become longer. This will not only fail to improve the internal resistance of the battery, but also increase the welding time between the tail body 22 and the lower end plate 1, reduce welding efficiency, and increase the risk of welding defects, thus increasing the welding defect rate.
[0102] The ratio of the width W30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is greater than or equal to 15% and less than or equal to 32%.
[0103] If the ratio of the width W30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is too small, the second solder line 220 will be too short, the effective welding area will be reduced, the current carrying capacity of the second solder line 220 will be weakened, the temperature at the second solder line 220 will rise, and the performance of the battery will be affected.
[0104] If the ratio of the width W30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is too large, the second solder line 220 will become longer. This will not only fail to improve the internal resistance of the battery, but also increase the welding time between the tail body 22 and the lower end plate 1, reduce welding efficiency, and increase the risk of welding defects, thus increasing the welding defect rate.
[0105] In some embodiments, the width W30 of the second solder mark 202 is greater than or equal to 1 mm and less than or equal to 2 mm, preferably 1.5 mm.
[0106] If the width W30 of the second solder mark 202 is too small, the second solder line 220 will be too short, the effective soldering area will be reduced, the current carrying capacity of the second solder line 220 will be weakened, and the temperature at the second solder line 220 will rise, affecting the performance of the battery.
[0107] If the width W30 of the second solder mark 202 is too large, the second solder line 220 will become longer. This will not only fail to improve the internal resistance of the battery, but also increase the welding time between the tail body 22 and the lower end plate 1, reduce welding efficiency, and increase the risk of welding defects, thus increasing the welding defect rate.
[0108] The ratio of the length L30 of the second weld mark 202 to the width L300 of the tail body 22 is greater than or equal to 56% and less than or equal to 76%.
[0109] If the ratio of the length L30 of the second solder mark 202 to the width L300 of the tail body 22 is too small, the second solder line 220 will be too short, the effective welding area will be reduced, the current carrying capacity of the second solder line 220 will be weakened, the temperature at the second solder line 220 will rise, and the performance of the battery will be affected.
[0110] If the ratio of the length L30 of the second solder mark 202 to the width L300 of the tail body 22 is too large, the second solder line 220 will become longer. This will not only fail to improve the internal resistance of the battery, but also increase the welding time between the tail body 22 and the lower end plate 1, reduce welding efficiency, and increase the risk of welding defects, thus increasing the welding defect rate.
[0111] In some embodiments, the width L300 of the tail body 22 is greater than or equal to 5 mm and less than or equal to 7 mm, preferably 6 mm. When the width L300 of the tail body 22 is 6 mm and the length L30 of the second solder mark 202 is 4 mm, the ratio of the length L30 of the second solder mark 202 to the width L300 of the tail body 22 is 66.7%.
[0112] In some embodiments, such as Figure 5 and Figure 7 As shown, the lower end plate 1 includes a boss 12 and vents 11. The boss 12 is located in the middle part of the lower end plate 1, and multiple vents 11 are provided, with multiple vents 11 arranged around the outer periphery of the boss 12; the second solder mark 202 is located between the boss 12 and the vents 11.
[0113] The radius R30 of the lower end plate 1 is greater than or equal to 5.29 mm and less than or equal to 7.29 mm, preferably 6.29 mm.
[0114] When the length L30 of the second solder mark 202 is 4mm, the width W30 of the second solder mark 202 is 1.5mm, and the radius R30 of the lower end plate 1 is 6.29mm, the ratio of the length L30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is 63.6%, and the ratio of the width W30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is 23.8%.
[0115] It should be noted that solder marks generally refer to the overall trace formed after welding, while weld lines refer to specific weld lines. If a solder mark corresponds to an area, then a weld line is a line within that area. This is common knowledge in the field and will not be elaborated further.
[0116] Through the description of several embodiments of the lithium-ion cylindrical battery of this utility model, it can be seen that the embodiments of the lithium-ion cylindrical battery of this utility model have at least one or more of the following advantages:
[0117] 1. By limiting the width and angle of the first bonding wire 210 and the second bonding wire 220, the width of the first bonding wire 210 and the second bonding wire 220 is set to 0.2-0.4mm to ensure a low-resistance current path, while enhancing the connection strength between the disk body 21 and the electrode tab, and between the tail body 22 and the lower end plate 1, thus avoiding insufficient overcurrent capacity or welding defects. Furthermore, the included angle of the first bonding wire 210 at the crest and trough is controlled at 10°.
[0118] -30°, the included angle of the second welding line 220 is controlled between 25° and 65° to balance the welding line length and arrangement density, reduce the welding defect rate, and improve the connection strength and battery performance stability.
[0119] 2. By limiting the ratio of the radius of the disc 21 to the radius of the core 4, the ratio of the radius R10 of the disc 21 to the radius R100 of the core 4 is controlled between 86.4% and 92.3% to reduce the risk of short circuit and ensure the effectiveness of the welding area. This can prevent the inner wall of the shell 3 from contacting the edge of the disc 21, ensure sufficient welding area, avoid the degradation of electrical performance, and balance battery safety and electrical performance.
[0120] 3. By limiting the relevant dimensions of the first solder mark 201, the ratio of the length L10 of the first solder mark 201 to the radius R10 of the disk body 21 is set between 42.9% and 56.0%, and the length L10 of the first solder mark 201 is 3.9-5.1 mm, to ensure low internal resistance current transmission and avoid misalignment between the soldering position of the disk body 21 and the electrode tab. Furthermore, the ratio of the width W10 of the first solder mark 201 to the radius R10 of the disk body 21 is controlled within a certain range.
[0121] 26.4%-35.2%, to balance the effective length of the welding line and the effectiveness of the welding area, thereby improving battery performance and connection strength.
[0122] 4. By limiting the relevant dimensions of the second solder mark 202, the ratio of the length L30 of the second solder mark 202 to the radius R30 of the lower end plate 1 and the width L300 of the tail body 22 are controlled at 56%-76%, and the ratio of the width W30 of the second solder mark 202 to the radius R30 of the lower end plate 1 is optimized to 15%-32%. The second solder mark 202 is set between the boss 12 and the vent 11 to accurately control the effectiveness of the welding area, ensure the current flow capacity and improve the welding efficiency, avoid deviation, and improve the connection strength and battery performance stability.
[0123] Finally, it should be noted that the various embodiments in this specification are described in a progressive manner, with each embodiment focusing on the differences from other embodiments. The same or similar parts between the various embodiments can be referred to each other.
[0124] The above embodiments are only used to illustrate the technical solution of this utility model and not to limit it; although the utility model has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications can still be made to the specific implementation of this utility model or equivalent substitutions can be made to some technical features without departing from the spirit of the technical solution of this utility model, and all such modifications and substitutions should be covered within the scope of the technical solution claimed by this utility model.
Claims
1. A lithium-ion cylindrical battery, comprising a core (4) and a positive electrode current collector (2), wherein the core (4) is provided with tabs, and the positive electrode current collector (2) comprises a disk body (21) and a tail body (22), wherein the disk body (21) is welded to the tabs, and the tail body (22) is welded to the lower end plate (1) of a cap; characterized in that, The disc body (21) is welded to the electrode tab to form a first weld mark (201), and the tail body (22) is welded to the lower end plate (1) to form a second weld mark (202); The ratio of the length L10 of the first solder mark (201) to the radius R10 of the disk body (21) is greater than or equal to 42.9% and less than or equal to 56.0%. The ratio of the width W10 of the first solder mark (201) to the radius R10 of the disk body (21) is greater than or equal to 26.4% and less than or equal to 35.2%; The ratio of the length L30 of the second solder mark (202) to the radius R30 of the lower end plate (1) is greater than or equal to 56% and less than or equal to 76%. The ratio of the width W30 of the second solder mark (202) to the radius R30 of the lower end plate (1) is greater than or equal to 15% and less than or equal to 32%.
2. The lithium-ion cylindrical battery according to claim 1, characterized in that, The length L10 of the first solder mark (201) is greater than or equal to 3.9 mm and less than or equal to 5.1 mm; The width W10 of the first solder mark (201) is greater than or equal to 2.4 mm and less than or equal to 3.2 mm.
3. The lithium-ion cylindrical battery according to claim 1, characterized in that, The length L30 of the second solder mark (202) is greater than or equal to 3.5 mm and less than or equal to 4.5 mm; The width W30 of the second solder mark (202) is greater than or equal to 1 mm and less than or equal to 2 mm.
4. The lithium-ion cylindrical battery according to claim 1, characterized in that, The first solder mark (201) includes a first solder line (210), the width W0 of the first solder line (210) being greater than or equal to 0.2 mm and less than or equal to 0.4 mm.
5. The lithium-ion cylindrical battery according to claim 4, characterized in that, The first bonding line (210) is wavy. The included angle formed by the first bonding line (210) at the crest of the wave is denoted as included angle A, which is greater than or equal to 10° and less than or equal to 30°. The included angle formed by the first bonding line (210) at the trough of the wave is denoted as included angle B, which is greater than or equal to 10° and less than or equal to 30°.
6. The lithium-ion cylindrical battery according to claim 1, characterized in that, The second solder mark (202) includes a second solder line (220), the width W301 of which is greater than or equal to 0.2 mm and less than or equal to 0.4 mm.
7. The lithium-ion cylindrical battery according to claim 6, characterized in that, The second bonding line (220) is wavy. The included angle formed by the second bonding line (220) at the crest of the wave is denoted as included angle E, which is greater than or equal to 25° and less than or equal to 65°. The included angle formed by the second bonding line (220) at the trough of the wave is denoted as included angle F, which is greater than or equal to 25° and less than or equal to 65°.
8. The lithium-ion cylindrical battery according to claim 1, characterized in that, The ratio of the length L30 of the second solder mark (202) to the width L300 of the tail body (22) is greater than or equal to 56% and less than or equal to 76%. And / or, the width L300 of the tail body (22) is greater than or equal to 5 mm and less than or equal to 7 mm.
9. The lithium-ion cylindrical battery according to claim 1, characterized in that, The lower end plate (1) includes a boss (12) and vents (11). The boss (12) is located in the middle part of the lower end plate (1). Multiple vents (11) are provided, and the multiple vents (11) are arranged around the outer periphery of the boss (12). The second solder mark (202) is located between the boss (12) and the vents (11). And / or, the radius R30 of the lower end plate (1) is greater than or equal to 5.29 mm and less than or equal to 7.29 mm.
10. The lithium-ion cylindrical battery according to claim 1, characterized in that, The disc body (21) also includes a central hole (211) and peripheral holes (212). The central hole (211) is located in the middle part of the disc body (21). Multiple peripheral holes (212) are provided, and the multiple peripheral holes (212) surround the outer periphery of the central hole (211). The ratio of the radius R10 of the disc body (21) to the radius R100 of the core (4) is greater than or equal to 86.4% and less than or equal to 92.3%. And / or, the radius R10 of the disk body (21) is greater than or equal to 8.8 mm and less than or equal to 9.4 mm; And / or, the radius R100 of the core (4) is greater than or equal to 9.18 mm and less than or equal to 11.18 mm.