Negative electrode bus assembly and cylindrical battery
By designing the central hole, bus area and guide bar structure on the bus plate of the negative electrode bus assembly, the conductivity of welding heat is reduced, the problems of hot melting of the diaphragm and internal short circuit are solved, and the welding quality and battery safety are improved.
Patent Information
- Application Number
- CN202420807050.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-18
- Publication Date
- 2025-05-13
- Estimated Expiration
- 2034-04-18
AI Technical Summary
Existing negative electrode bus assembly can easily cause the diaphragm to be hot melt during welding, and increasing the flange height to reduce heat conduction efficiency will affect the battery capacity.
A negative electrode bus assembly is designed, with a concentric central hole in the middle of the bus plate and a plurality of bus regions distributed in the circumferential direction. The edge of the bus region has a cut groove and a flow guide bar. The flow guide bar is bent to make the bus region generally depress and reduces the heat conduction efficiency.
It effectively reduces the conductivity of welding heat, avoids the risk of hot melting of the diaphragm and internal short circuit, and improves welding quality and battery safety.
Smart Images
Figure CN222867991U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a negative electrode busbar assembly and a cylindrical battery. Background Art
[0002] The busbar is welded to the pole ear of the winding core and is used to gather current and transmit the current of the pole piece of the winding core. The negative electrode busbar assembly mainly includes a busbar and a cover plate. There are usually two common connection structures between the busbar and the cover plate. One is to weld the cover plate with a conductive handle extending integrally from the busbar, and the other is to set an outward flange on the edge of the busbar, and make the flange contact with the shell. After the cover plate is covered, the cover plate, the shell and the flange are welded together at one time. However, in this structure, once the height of the flange is low, the welding heat is easily conducted to the pole piece through the busbar and causes the diaphragm to melt. Increasing the height of the flange requires shortening the length of the winding core, which affects the battery capacity. Utility Model Content
[0003] In view of the above-mentioned deficiencies of the prior art, the technical problem to be solved by the present invention is: how to provide a negative electrode bus assembly and cylindrical battery with a reasonable structural design that can reduce the heat conduction efficiency of the bus plate, avoid hot melting of the diaphragm, and improve the welding quality.
[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0005] A negative electrode bus assembly, comprising a circular bus plate and a cover plate, characterized in that the middle part of the bus plate has a concentrically arranged center hole, the outer side of the center hole has a plurality of bus areas evenly distributed along the circumferential direction, and the edge of each bus area has a cutting groove, the cutting groove includes two first cutting grooves arranged radially, and the ends of the two first cutting grooves away from the center hole are connected to second cutting grooves arranged circumferentially; a guide bar radially connecting the middle area and the edge area of the bus plate is formed between two adjacent bus areas, the inner end of the guide bar is bent toward one side of the bus plate, and the center hole and the plurality of bus areas are recessed as a whole; the edge of the bus plate has a flange protruding in a recessed direction away from the bus area, and the outer diameter of the flange matches the inner diameter of the battery shell to be assembled; the cover plate has a positioning flange protruding in the direction of the bus plate, the diameter of the positioning flange matches the inner diameter of the flange, and the height is less than the height of the flange.
[0006] In the above structure, since the outer diameter of the flange matches the inner diameter of the shell, and the inner diameter of the flange matches the diameter of the positioning flange of the cover plate, during assembly, the flange of the busbar will be concentrically embedded between the positioning flange of the cover plate and the shell, so that the three can be welded together, which is conducive to ensuring welding efficiency. In addition, since the middle area and the edge area of the busbar are connected by the guide bar, and the guide bar is bent to one side, the busbar area is concave as a whole and forms a height difference with the edge. During welding, the welding heat can only be conducted to the busbar area through the guide bar, thereby greatly reducing the thermal conductivity, thereby reducing the risk of hot melting of the diaphragm and internal short circuit, which is conducive to ensuring the qualified rate.
[0007] Furthermore, an annular boss is formed on the edge of the center hole in a direction away from the flange, and the outer diameter of the annular boss matches the inner diameter of the core hole of the winding core to be assembled.
[0008] In this way, on the one hand, it is convenient for the electrolyte to flow from the center hole, and on the other hand, the annular boss can cooperate with the core hole of the winding core to realize the rapid positioning of the collector plate, greatly improving the production efficiency. At the same time, the annular boss plays a supporting role for the core hole of the winding core to prevent the two ends of the core hole from internal collapse in the later stage of the cycle.
[0009] Furthermore, the height of the annular boss is 1 to 3 mm.
[0010] Furthermore, the first cutting groove is connected to a weakening groove extending circumferentially toward the confluence area.
[0011] In this way, once the pressure inside the core increases, the gas between the two adjacent layers of pole pieces on the core will flow circumferentially to the location of the cutting groove and spray out from the cutting groove. At this time, the cutting groove will be squeezed by the internal pressure and will be expanded along the weakening groove to form a larger opening, so as to quickly relieve the pressure of the core, thereby preventing the core from expanding radially due to the internal pressure of the core. This reduces the risk of thermal runaway of the battery and is conducive to improving battery safety.
[0012] Furthermore, at least two weakening grooves are arranged at intervals along the length direction of the cutting groove.
[0013] Furthermore, the cover plate has a circular recessed portion on one side facing away from the busbar, and the other side of the recessed portion relatively protrudes to form the positioning flange.
[0014] Furthermore, the middle portion of the cover plate has an explosion-proof notch arranged in a C shape.
[0015] In this way, the C-shaped explosion-proof notch can facilitate internal splashes to break through the explosion-proof notch and spray out, while allowing the damaged part to remain connected to the cover plate.
[0016] Furthermore, the central angle corresponding to the explosion-proof notch is 270° to 300°.
[0017] A cylindrical battery, characterized in that it includes a shell, a winding core and the negative electrode busbar assembly as described above, the busbar area is welded to the pole ear of the winding core, the positioning flange of the cover plate is cooperatively covered on one end of the shell, and the flange is concentrically embedded between the positioning flange and the shell; the cover plate, the shell and the flange are welded together.
[0018] In summary, the negative electrode busbar assembly and cylindrical battery of the present invention have the advantages of reasonable structural design, which can reduce the heat conduction efficiency of the busbar, avoid hot melting of the diaphragm, and help improve welding quality. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 Schematic diagram of the overall structure of a cylindrical battery.
[0020] Figure 2 Schematic diagram of the dispersed structure of the negative electrode bus assembly.
[0021] Figure 3 A partial cross-sectional view of a cylindrical battery.
[0022] Figure 4 for Figure 3 Enlarged image of the circle in the middle.
[0023] Figure 5 and Figure 6 It is a structural diagram of the busbar. DETAILED DESCRIPTION
[0024] The utility model is further described in detail below in conjunction with the embodiments.
[0025] When implementing: Figure 1 to Figure 6As shown, a cylindrical battery comprises a negative electrode busbar assembly, a shell 3 and a winding core 4, wherein the negative electrode busbar assembly comprises a circular busbar plate 1 and a cover plate 2, wherein the middle of the busbar plate 1 has a concentrically arranged center hole 11, and the outer side of the center hole 11 has a plurality of busbar areas 12 uniformly arranged along the circumferential direction, and the edge of each busbar area 12 has a cutting groove 13, wherein the cutting groove 13 comprises two first cutting grooves arranged radially, and the ends of the two first cutting grooves away from the center hole 11 are connected to the second cutting grooves arranged circumferentially; a guide bar 14 is formed between two adjacent busbar areas 12 to radially connect the middle area and the edge area of the busbar plate 1, and the inner end of the guide bar 14 is bent toward one side of the busbar plate 1, and the guide bar 14 is bent toward the inner end of the busbar plate 1, so that the guide bar 14 is bent toward the inner end ... The center hole 11 and the plurality of the merging areas 12 are integrally recessed; the edge of the merging plate 1 has a flange 15 protruding in the recessed direction away from the merging area 12, and the outer diameter of the flange 15 matches the inner diameter of the battery shell to be assembled; the cover plate 2 has a positioning flange 21 protruding in the direction of the merging plate 1, and the diameter of the positioning flange 21 matches the inner diameter of the flange 15, and the height is less than the height of the flange 15; the merging area 12 is welded to the pole ear of the winding core 4, and the positioning flange 21 of the cover plate 2 is cooperatively covered on one end of the shell 3, and the flange 15 is concentrically embedded between the positioning flange 21 and the shell 3; the cover plate 2, the shell 3 and the flange 15 are welded to each other.
[0026] The edge of the center hole 11 protrudes in a direction away from the flange 15 to form an annular boss, the outer diameter of the annular boss matches the inner diameter of the core hole to be assembled, and the height of the annular boss is 1-3 mm.
[0027] In this embodiment, the first cutting groove is connected to a weakening groove 16 extending circumferentially toward the confluence area 12 , and two weakening grooves 16 are arranged at intervals along the length direction of the cutting groove 13 .
[0028] In this way, once the pressure inside the core increases, the gas between the two adjacent layers of pole pieces on the core will flow circumferentially to the location of the cutting groove and spray out from the cutting groove. At this time, the cutting groove will be squeezed by the internal pressure and will be expanded along the weakening groove to form a larger opening, so as to quickly relieve the pressure of the core, thereby preventing the core from expanding radially due to the internal pressure of the core. This reduces the risk of thermal runaway of the battery and is conducive to improving battery safety.
[0029] The cover plate 2 has a circular recessed portion on one side away from the busbar 1, and the other side of the recessed portion relatively protrudes to form the positioning flange 21; the middle part of the cover plate 2 has a C-shaped explosion-proof notch 22, and the central angle of the explosion-proof notch 22 is 270° to 300°. The C-shaped explosion-proof notch can facilitate the internal splashes to break through the explosion-proof notch and spray out, and can also keep the damaged part connected to the cover plate.
[0030] In this embodiment, since the outer diameter of the flange matches the inner diameter of the shell, and the inner diameter of the flange matches the diameter of the positioning flange of the cover plate, during assembly, the flange of the busbar will be concentrically embedded between the positioning flange of the cover plate and the shell, so that the three can be welded together, which is conducive to ensuring welding efficiency. In addition, since the middle area and the edge area of the busbar are connected by the guide bar, and the guide bar is bent to one side, the busbar area is concave as a whole and forms a height difference with the edge. During welding, the welding heat can only be conducted to the busbar area through the guide bar, thereby greatly reducing the thermal conductivity, thereby reducing the risk of hot melting of the diaphragm and internal short circuit, which is conducive to ensuring the qualified rate.
[0031] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention shall be included in the protection scope of the present invention.
Claims
1. A negative electrode busbar assembly, comprising a circular busbar plate (1) and a cover plate (2), characterized in that: The central part of the busbar (1) has a concentrically arranged center hole (11), the outer side of the center hole (11) has a plurality of busbar areas (12) uniformly arranged in the circumferential direction, the edge of each busbar area (12) has a cutting groove (13), the cutting groove (13) comprises two first cutting grooves arranged in the radial direction, the ends of the two first cutting grooves away from the center hole (11) are connected to second cutting grooves arranged in the circumferential direction; a guide bar (14) is formed between two adjacent busbar areas (12) to radially connect the central area and the edge area of the busbar (1), the guide bar ( The inner end of the cover plate (14) is bent toward one side of the busbar (1), and the central hole (11) and the plurality of busbar areas (12) are integrally recessed; the edge of the busbar (1) has a flange (15) protruding in a recessed direction away from the busbar area (12), and the outer diameter of the flange (15) matches the inner diameter of the battery housing to be assembled; the cover plate (2) has a positioning flange (21) protruding in a direction toward the busbar (1), and the diameter of the positioning flange (21) matches the inner diameter of the flange (15), and the height is less than the height of the flange (15).
2. The negative electrode bus assembly according to claim 1, characterized in that: An annular boss is formed on the edge of the central hole (11) in a direction away from the flange (15), and the outer diameter of the annular boss matches the inner diameter of the core hole of the winding core to be assembled.
3. The negative electrode bus assembly according to claim 2, characterized in that: The height of the annular boss is 1 to 3 mm.
4. The negative electrode bus assembly according to claim 1, characterized in that: The first cutting groove is connected to a weakening groove (16) extending in the circumferential direction toward the confluence area (12).
5. The negative electrode bus assembly according to claim 4, characterized in that: At least two weakening grooves (16) are arranged at intervals along the length direction of the cutting groove (13).
6. The negative electrode bus assembly according to claim 1, characterized in that: The cover plate (2) has a circular recessed portion on one side facing away from the busbar (1), and the other side of the recessed portion forms the positioning flange (21) in a relatively protruding manner.
7. The negative electrode bus assembly according to claim 6, characterized in that: The middle portion of the cover plate (2) has an explosion-proof notch (22) arranged in a C shape.
8. The negative electrode bus assembly according to claim 7, characterized in that: The central angle corresponding to the explosion-proof notch (22) is 270° to 300°.
9. A cylindrical battery, characterized in that: The invention comprises a shell (3), a winding core (4) and a negative electrode bus assembly as claimed in any one of claims 1 to 8, wherein the bus area (12) is welded to the pole ear of the winding core (4), the positioning flange (21) of the cover plate (2) is cooperatively covered on one end of the shell (3), and the flange (15) is concentrically embedded between the positioning flange (21) and the shell (3); the cover plate (2), the shell (3) and the flange (15) are welded to each other.