Welding printing structure, collector plate welding structure and cylindrical battery

Abstract

The utility model provides a welding mark structure, a collector plate welding structure and a cylindrical battery, which belong to the field of new energy batteries, a plurality of welding mark structures are arranged on the surface of the welding mark structure around the center of a collector plate, each welding mark structure comprises a plurality of welding wires arranged in parallel, and a first gap is reserved between every two adjacent welding wires. The layout direction of the welding wire is used as the width direction of the welding printing structure, and the width of the first gap is 12%-22% of the width of the welding printing structure. Through the design of the bonding wire gap, the current guide path is shortened, the ohmic loss is reduced, the uniform distribution of current is ensured, and the internal resistance of the battery is reduced.

Description

Technical Field

[0001] This utility model relates to the field of new energy battery technology, and in particular to a soldering structure, a current collector welding structure, and a cylindrical battery. Background Technology

[0002] In current cylindrical batteries, the current collector serves to conduct electricity by connecting the positive terminal of the core and the cap via laser welding. Therefore, the current collector typically has four sets of solder marks, each consisting of three individual solder lines. Extensive research and experimentation have revealed that each solder line needs to be maintained within a reasonable distance from the others: if the spacing between the solder lines is too large, the process cannot meet requirements, and the solder lines are prone to deviating from the solderable area of ​​the current collector, resulting in a longer current path, higher internal resistance, uneven current distribution, and insufficient weld strength. Conversely, if the spacing between the solder lines is too small, it can easily lead to weld bursts and other problems, and may also cause concentrated welding heat, resulting in excessive rate rise, and still potentially insufficient weld strength.

[0003] Therefore, designing the spacing of the solder wires on the current collector to ensure the normal charging and discharging capability of the cylindrical battery is a problem that urgently needs to be solved by those skilled in the art. Utility Model Content

[0004] In view of this, this utility model proposes a soldering structure, a current collector welding structure, and a cylindrical battery to solve the problem of how to design the spacing of the solder lines on the current collector to be within a reasonable numerical range.

[0005] The technical solution of this utility model is implemented as follows: This utility model provides a soldering structure, including a plurality of parallel solder lines, with a first gap between adjacent solder lines, the solder line layout direction being the width direction of the soldering structure, and the width of the first gap being 12% to 22% of the width W0 of the soldering structure.

[0006] Based on the above technical solutions, preferably, the width W1 of the solder line is 17% to 27% of the width W0 of the solder mark structure.

[0007] Based on the above technical solutions, preferably, the welding wire includes two sets of arc segments, which are arranged on both sides of the welding wire extension direction. The two sets of arc segments are arranged alternately and connected end to end to form a wave shape. The included angle of the tangents at both ends of the arc segments is 50° to 75°.

[0008] Secondly, this utility model also provides a collector plate welding structure, including a collector plate and the above-mentioned welding stamp structure. Several sets of welding stamp structures are arranged around the center of the collector plate. A central hole is opened in the center of the collector plate. Several vent holes are opened around the central hole on the collector plate. Each vent hole is respectively arranged between adjacent welding stamp structures.

[0009] Based on the above technical solutions, preferably, the collector plate is circular, and a second gap is left between the end of the soldered structure facing the central hole and the central hole, and the width of the second gap is 5% to 15% of the radius R1 of the collector plate.

[0010] Based on the above technical solutions, preferably, a third gap is left between the end of the soldering structure away from the central hole and the outer contour edge of the collector plate, and the width of the third gap is 5% to 15% of the collector plate radius R1.

[0011] Based on the above technical solutions, preferably, the shortest distance between the outermost weld line of the soldering structure and the adjacent vent hole is the fourth gap, and the width of the fourth gap is 7% to 17% of the radius R1 of the manifold.

[0012] Based on the above technical solutions, preferably, the shortest distance between the edge of the exhaust hole and the edge of the center hole is the fifth gap, and the shortest distance between the edge of the exhaust hole and the outer contour edge of the collector plate is the sixth gap. The width of the fifth gap is 5% to 20% of the collector plate radius R1, and the width of the sixth gap is 22% to 32% of the collector plate radius R1.

[0013] Based on the above technical solutions, preferably, the included angle between the axes of two adjacent soldering structures extending in the direction of extension is 75° to 105°.

[0014] Thirdly, this utility model also provides a cylindrical battery that adopts the above-mentioned soldering structure or the above-mentioned current collector welding structure.

[0015] The soldering structure, current collector welding structure, and cylindrical battery of this utility model have the following advantages over the prior art:

[0016] (1) This utility model shortens the current conduction path, reduces ohmic loss, ensures uniform current distribution, and reduces battery internal resistance by designing the soldering structure size and soldering line gap.

[0017] (2) This utility model avoids weld line deviation, burst points and local temperature rise by precisely controlling the distance between the soldering structure and the key structure, thereby improving the welding strength and heat dissipation efficiency.

[0018] (3) The present invention ensures the consistency of exhaust through the isolation design of the exhaust hole and the welding stamp structure, and avoids the welding heat from interfering with the function of the explosion-proof valve; at the same time, the reasonable process tolerance range reduces the manufacturing difficulty and improves the yield. Attached Figure Description

[0019] 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.

[0020] Figure 1 This is a top view of the collector plate of this utility model;

[0021] Figure 2 This is a top view of the solder joint structure of this utility model;

[0022] Figure 3 For the present utility model Figure 2 Enlarged view of point A in the middle.

[0023] In the diagram: 1. Collector plate; 101. Center hole; 102. Vent hole; 2. Welding stamp structure; 21. Weld line; 211. Arc segment; 201. First gap; 202. Second gap; 203. Third gap; 204. Fourth gap; 205. Fifth gap; 206. Sixth gap. Detailed Implementation

[0024] The technical solutions of this utility model will be clearly and completely described below with reference to the embodiments of this utility model. 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 of ordinary skill in the art without creative effort are within the protection scope of this utility model.

[0025] like Figure 1 As shown, combined with Figure 2This utility model discloses a soldering structure comprising several parallel solder lines 21, with a first gap 201 between adjacent solder lines 21. If the width of the first gap 201 is too large, the process cannot meet requirements, and the solder lines 21 are prone to deviating from the solderable area on the current collector 1, increasing ineffective conductive paths and leading to a longer current path, as well as problems such as high internal resistance and uneven current flow. Furthermore, it can easily cause insufficient weld connection strength. Conversely, if the width of the first gap 201 is too small, it can cause localized over-melting due to concentrated welding energy, leading to problems such as weld bursts. It may also cause concentrated heat generation during welding of the current collector 1, resulting in excessive temperature rise, and may still lead to insufficient weld connection strength. Based on the above, with the solder line 21 arrangement direction as the width direction of the soldering structure 2, the width of the first gap 201 is 12% to 22% of the width W0 of the soldering structure 2. For example, in this embodiment, the width W0 of the solder mark structure 2 is 2.3 mm (preferably within the range of 2 mm to 3 mm), and the width of the first gap 201 is 0.4 mm (preferably within the range of 0.3 mm to 0.5 mm). The width of the first gap 201 is 17% of the width W0 of the solder mark structure 2.

[0026] exist Figure 2 In a preferred embodiment shown, the width W1 of the bonding wire 21 is 17% to 27% of the width W0 of the solder mark structure 2. The reason for designing this width range is that if the width W1 of the bonding wire 21 is too large, it will easily deviate from the solderable area on the current collector 1, resulting in a longer current path, leading to higher internal resistance and uneven current distribution in the battery, and also potentially causing insufficient weld strength. Conversely, if the width W1 of the bonding wire 21 is too small, it can easily lead to problems such as weld bursts, and may also cause concentrated heat generation during welding of the current collector 1, resulting in excessive rate rise. Furthermore, it may still cause insufficient weld strength. For example, in this embodiment, the width W0 of the solder mark structure 2 is 2.3 mm (preferably within the range of 2 mm to 3 mm), while the width W1 of the bonding wire 21 is 0.5 mm (preferably within the range of 0.4 mm to 0.6 mm), and the width W1 of the bonding wire 21 is 22% of the width W0 of the solder mark structure.

[0027] exist Figure 3In a preferred embodiment shown, the welding wire 21 includes two sets of arc segments 211, which are arranged on both sides of the extension direction of the welding wire 21. The two sets of arc segments 211 are alternately arranged and connected end to end to form a wave shape. Ideally, the arc segment 211 can be a circular arc with an arc angle of 50° to 75°. However, in actual implementation, the arc segment 211 is usually designed as a non-circular arc, but as a parabola or a triangle with rounded corners. In this case, the included angle of the tangents at both ends of the arc segment 211 is 50° to 75°, and the included angle of the two sets of arc segments 211 is the same. For example, in this embodiment, the included angle of the tangents at both ends of the arc segment 211 is 60°. If the included angle of the tangents at both ends of the arc segment 211 is too large, it will affect the consistency of the current flow of the current collector 1. If the included angle is too small, it will affect the current flow heat dissipation effect of the current collector 1 and weaken the welding strength between the current collector 1 and the core.

[0028] like Figure 1 As shown, this utility model discloses a current collector, more precisely a positive current collector, which is laser-welded between the positive terminal of the core and the cap of a cylindrical battery. Its function is to collect and conduct electricity. Several solder structures 2 are arranged around the center of the current collector 1 on its surface. These solder structures 2 connect the current collector 1 to the core, ensuring sufficient current flow and structural strength. The current collector 1 is circular, with a central hole 101 at its center, serving for liquid injection and venting. Several vent holes 102 are arranged around the central hole 101 on the current collector 1. These vent holes 102 mainly assist in venting the battery cell. Each vent hole 102 is located between adjacent solder structures 2. Generally, the axis of the solder structure 2's extension direction coincides with the radial axis of the current collector 1, but the axis of the solder structure 2's extension direction can also be offset from the radial axis of the current collector 1.

[0029] exist Figure 1In a preferred embodiment shown, the width and length of the solder mark structure 2 are within a reasonable design range. If the overall width or length of the solder mark structure 2 is too large, the solder wire 21 may easily deviate from the solderable area on the current collector 1, making the current guiding path longer, resulting in higher battery internal resistance, uneven current flow, and insufficient weld connection strength. If the overall width or length of the solder mark structure 2 is too small, it may easily lead to problems such as weld bursts, and may also cause concentrated welding heat, resulting in excessive rate rise, and may still cause insufficient weld connection strength. The length of the solder mark structure 2 is actually designed based on the radius of the current collector 1. Therefore, its length must match the radius of the current collector 1 to ensure that the solder mark structure 2 can cover a sufficient solderable area without extending into non-functional areas (e.g., extending to the position of the vent hole 102 or the weak area near the edge of the current collector 1). Therefore, the distance between the end of the solder mark structure 2 and the center hole 101 also needs to be designed to balance the current density and current distribution uniformity, and meet the process feasibility. Typically, a second gap 202 is left between the end of the solder mark structure 2 facing the center hole 101 and the center hole 101. The second gap 202 is a buffer area of ​​the solder mark structure 2 near the center hole 101 of the current collector 1. Its function is to prevent the welding heat from affecting the area of ​​the center hole 101 through metal conduction, and thus affecting the sealing structure or explosion-proof valve of the battery. At the same time, by limiting the distance between the solder mark structure 2 and the center hole 101, the path of current from the welding wire 21 to the current collector 1 is minimized. The width of the second gap 202 is 5% to 15% of the radius of the current collector 1. If the gap is too large, the current conduction path will be longer, resulting in a larger internal resistance of the battery and uneven current flow. In addition, it is also easy to cause insufficient welding connection strength. If the gap is too small, it may cause the welding heat to be concentrated, resulting in excessive rate rise. On the other hand, it will greatly increase the difficulty of process preparation, causing the welding wire 21 to easily deviate from the solderable area on the current collector 1. In addition, it may still cause insufficient welding connection strength. For example, in this embodiment, the width W0 of the solder mark structure 2 is 2.3 mm (preferably within the range of 2 mm to 3 mm), the length is 5 mm (preferably within the range of 4 mm to 6 mm), the disk radius R1 is 9.1 mm (preferably within the range of 8.5 mm to 9.6 mm), the width of the second gap 202 is 0.8 mm (preferably within the range of 0.6 mm to 1 mm), and the width of the second gap 202 is 9% of the radius R1 of the collector disk 1.

[0030] exist Figure 1In a preferred embodiment shown, a third gap 203 is left between the end of the solder mark structure 2 away from the central hole 101 and the outer contour edge of the current collector 1. The function of the third gap 203 is to balance the structural strength of the current collector 1 edge and the current conduction requirements. Since the edge of the current collector 1 is a mechanically weak area, it is necessary to avoid the solder mark structure 2 being too close, which could cause micro-cracks during stamping or welding. At the same time, it optimizes the current conduction efficiency of the current collector 1, avoiding the current having to take a longer path, which would increase the internal resistance. The width of the third gap 203 is 5% to 15% of the radius of the current collector 1. If the distance between the solder mark structure 2 and the edge of the current collector 1 is too large, the current conduction path will be longer, resulting in a larger internal resistance of the battery and uneven current flow. In addition, it is also easy to cause insufficient welding connection strength. If the distance is too small, it may cause concentrated welding heat, resulting in excessive rate rise. On the other hand, it will greatly increase the difficulty of process preparation, causing the solder line 21 to easily deviate from the solderable area on the current collector 1. In addition, it may still cause insufficient welding connection strength. For example, in this embodiment, the width W0 of the solder mark structure 2 is 2.3 mm (preferably within the range of 2 mm to 3 mm), the length is 5 mm (preferably within the range of 4 mm to 6 mm), the disk radius R1 is 9.1 mm (preferably within the range of 8.5 mm to 9.6 mm), the width of the third gap 203 is 0.8 mm (preferably within the range of 0.5 mm to 1.1 mm), and the width of the third gap 203 is 9% of the radius R1 of the collector disk 1.

[0031] exist Figure 1 In a preferred embodiment shown, the distance between the side of the solder mark structure 2 and the vent hole 102 also needs to be designed. If the solder line 21 is too close to the vent hole 102, welding residue (such as metal spatter) may block the vent hole and affect the venting efficiency. The shortest distance between the outermost solder line 21 of the solder mark structure 2 and the adjacent vent hole 102 is the fourth gap 204, and the width of the fourth gap 204 is 7% to 17% of the radius of the current collector 1. If the distance between the solder mark structure 2 and the adjacent vent hole 102 is too large, the current guiding path will be longer, resulting in a larger internal resistance of the battery and uneven current flow. In addition, it is also easy to cause insufficient welding connection strength. If the distance is too small, it may cause concentrated welding heat, resulting in excessive rate rise. On the other hand, it will greatly increase the difficulty of process preparation, causing the solder line 21 to easily deviate from the solderable area on the current collector 1. In addition, it may still cause insufficient welding connection strength. For example, in this embodiment, the width W0 of the solder mark structure 2 is 2.3 mm (preferably within the range of 2 mm to 3 mm), the length is 5 mm (preferably within the range of 4 mm to 6 mm), the disk radius R1 is 9.1 mm (preferably within the range of 8.5 mm to 9.6 mm), the width of the fourth gap 204 is 1 mm (preferably within the range of 0.7 mm to 1.3 mm), and the width of the fourth gap 204 is 11% of the radius R1 of the collector disk 1.

[0032] exist Figure 1In a preferred embodiment shown, the shortest distance between the edge of the vent hole 102 and the edge of the center hole 101 is designated as the fifth gap 205, and the shortest distance between the edge of the vent hole 102 and the outer contour edge of the collector plate 1 is designated as the sixth gap 206. The width of the fifth gap 205 is 5% to 20% of the radius R1 of the collector plate 1, and the width of the sixth gap 206 is 22% to 32% of the radius R1 of the collector plate 1. Optimizing the distance between the vent hole 102 and the center hole 101 is to prevent interference from thermal expansion or mechanical deformation of the center hole 101 and the vent hole 102, and to avoid gas leakage from the center hole due to excessively small distances, instead of being directionally discharged through the explosion-proof valve, thus affecting the safety response speed. Optimizing the distance between the vent hole 102 and the edge of the collector plate 1 provides sufficient mechanical support for the vent hole 102, preventing deformation of the vent hole 102 due to pressure on the edge of the collector plate 1 during battery encapsulation; simultaneously, the sixth gap 206 ensures that gas is discharged uniformly from the vent hole 102, avoiding local pressure accumulation. For example, in this embodiment, the disk radius R1 is 9.1 mm (preferably within the range of 8.5 mm to 9.6 mm), the width of the fifth gap 205 is 1.1 mm (preferably within the range of 0.8 mm to 1.4 mm), and the width of the fifth gap 205 is 12% of the radius R1 of the collector disk 1; the width of the sixth gap 206 is 2.5 mm (preferably within the range of 1.5 mm to 3.5 mm), and the width of the sixth gap 206 is 27.5% of the radius R1 of the collector disk 1.

[0033] exist Figure 1 In a preferred embodiment shown, the included angle between the axes of two adjacent solder structures 2 extending in the direction of extension is 75° to 105°. If the angle is too large, it will cause uneven current distribution, resulting in higher internal resistance of the battery; if the angle is too small, it will cause concentrated welding heat, leading to excessive rate-controlled temperature rise. For example, in... Figure 1 In the embodiment shown, the current collector 1 is designed with four solder pad structures 2. The four solder pad structures 2 are arranged symmetrically in pairs relative to the central axis of the current collector 1. The included angle between the two upper solder pad structures 2 is 75°, and the included angle between the two lower solder pad structures 2 is 105°. The combination of the upper 75° and the lower 105° included angles can achieve dynamic current balance among the multiple solder pad structures 2 and avoid the overlap of the heat-affected zones of adjacent solder pad structures 2.

[0034] like Figure 1 As shown, combined with Figure 2 The cylindrical battery of this utility model adopts a soldering structure of any of the above embodiments, or a current collector welding structure of any of the above embodiments.

[0035] 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 solder print structure, characterized by: The welding line (21) comprises a plurality of parallel welding lines (21), and a first gap (201) is left between adjacent welding lines (21). The welding line (21) is arranged in the width direction of the welding structure (2), and the width of the first gap (201) is 12%-22% of the width W0 of the welding structure (2).

2. A weld bead structure according to claim 1, wherein: The width W1 of the welding line (21) is 17%-27% of the width W0 of the welding structure (2).

3. A weld bead structure according to claim 1, wherein: The welding line (21) comprises two groups of arc segments (211), and the two groups of arc segments (211) are arranged on both sides of the extension direction of the welding line (21). The two groups of arc segments (211) are alternately arranged and connected end to end to form a wave shape, and the included angle of the tangent lines at the two ends of the arc segment (211) is 50°-75°.

4. A current collector plate welding structure characterized by: The welding structure (2) comprises a current collecting plate (1) and any one of the welding structures (2) according to claims 1-3. The current collecting plate (1) is arranged around the center of the surface and comprises a plurality of groups of welding structures (2). The center of the current collecting plate (1) is provided with a center hole (101), and a plurality of exhaust holes (102) are arranged around the center hole (101) on the current collecting plate (1). Each exhaust hole (102) is arranged between adjacent welding structures (2).

5. A current plate welding structure according to claim 4, wherein: The current collecting plate (1) is circular, and a second gap (202) is left between one end of the welding structure (2) facing the center hole (101) and the center hole (101). The width of the second gap (202) is 5%-15% of the radius R1 of the current collecting plate (1).

6. The current plate welding structure of claim 4, wherein: A third gap (203) is left between one end of the welding structure (2) away from the center hole (101) and the outer contour edge of the current collecting plate (1). The width of the third gap (203) is 5%-15% of the radius R1 of the current collecting plate (1).

7. The current plate welding structure of claim 4, wherein: The shortest distance between the welding line (21) located at the outermost side of the welding structure (2) and the adjacent exhaust hole (102) is the fourth gap (204). The width of the fourth gap (204) is 7%-17% of the radius R1 of the current collecting plate (1).

8. The current plate welding structure of claim 4, wherein: The shortest distance between the edge of the exhaust hole (102) and the edge of the center hole (101) is the fifth gap (205), and the shortest distance between the edge of the exhaust hole (102) and the outer contour edge of the current collecting plate (1) is the sixth gap (206). The width of the fifth gap (205) is 5%-20% of the radius R1 of the current collecting plate (1), and the width of the sixth gap (206) is 22%-32% of the radius R1 of the current collecting plate (1).

9. The current plate welding structure of claim 4, wherein: The included angle between the axes of the extension directions of two adjacent welding structures (2) is 75°-105°.

10. A cylindrical battery characterized by comprising: The welding structure according to any one of claims 1-3 or the current collecting plate welding structure according to any one of claims 4-9 is adopted.

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