A busbar and cylindrical battery
By designing a bus disk structure with a cut-off groove and a weakening groove, the problem of the bus disk in a lithium battery that needs to be squeezed out to relieve pressure when the battery fails, reducing the risk of battery thermal runaway and improving the safety of the battery.
Patent Information
- Application Number
- CN202420806915.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2024-04-18
- Publication Date
- 2025-04-01
- Estimated Expiration
- 2034-04-18
AI Technical Summary
In existing lithium batteries, the bus disk needs to be squeezed out to relieve pressure when the battery fails, causing the battery cover to expand or break radially, increasing the risk of thermal runaway from the battery and affecting safety.
A bus disk is designed, which includes a circular bus plate, with a central hole in the middle of the bus plate, and a plurality of bus zones distributed in the circumferential direction outside the central hole. There are cutting grooves and weakening grooves in the adjacent bus zones. The weakening grooves are connected to the cutting grooves, and they all penetrate in the axial direction. When the internal pressure rises, gas flows in the circumferential direction and is ejected from the cut-off groove, forming a larger opening through the weakening groove for rapid pressure relief.
By reducing the local strength of the bus disk, the risk of thermal runaway from the battery is reduced and the safety of the battery is improved.
Smart Images
Figure CN222705767U_ABST
Abstract
Description
Technical Field
[0001] The utility model relates to the technical field of lithium batteries, in particular to a busbar and a cylindrical battery. Background Art
[0002] At present, with the rapid development of the new energy industry, society's requirements for the energy density, safety performance, and fast charging performance of lithium-ion batteries have been further improved. As a highly recognized solution, large cylindrical batteries have ushered in a broad market space. Single cylindrical batteries are usually assembled in the form of battery modules. In the module, the cylindrical batteries are arranged side by side. In order to improve the overall safety of the battery module, the single cylindrical battery is required to release pressure in the axial direction when a fault explodes, to avoid radial expansion or rupture of the battery shell, to reduce the extrusion of adjacent single cylindrical batteries, and to reduce the risk of thermal runaway of the battery. For this reason, an explosion-proof valve is provided on the battery cover. However, the battery cover also has a busbar welded to the winding core. The internal pressure generated when the battery fails needs to squeeze the busbar open before it can be released through the explosion-proof valve. For this reason, how to improve the busbar structure to improve battery safety has become an urgent problem to be solved. 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 busbar and a cylindrical battery with a reasonable structural design, which can reduce the local strength of the busbar and is conducive to improving the safety of the battery.
[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:
[0005] A busbar, characterized in that it includes a circular busbar, wherein the middle part of the busbar has a concentrically arranged center hole, the outer side of the center hole has a plurality of busbar areas evenly distributed along the circumferential direction, and a cutting groove extending radially is provided between two adjacent busbar areas, and the cutting groove is connected to a weakening groove extending circumferentially toward the busbar area, and the cutting groove and the weakening groove both penetrate the busbar axially.
[0006] In the above structure, the weakening groove extending along the circumferential direction is set on the cutting groove between two adjacent confluence areas. Once the internal pressure of the winding core increases, the gas between the two adjacent layers of pole pieces on the winding 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 winding core, thereby preventing the internal pressure of the winding core from causing the winding core to expand radially. The above structure reduces the local strength of the confluence plate through the weakening groove, reduces the risk of thermal runaway of the battery, and is conducive to improving battery safety.
[0007] Furthermore, at least two weakening grooves are arranged at intervals along the length direction of the cutting groove.
[0008] In this way, the overall strength of both sides of the cut-off groove can be further reduced so as to be better blasted.
[0009] Furthermore, the confluence area has a plurality of radially arranged collecting grooves, and the collecting grooves penetrate the confluence area along the axial direction.
[0010] In this way, the electrolyte can be quickly discharged through the collecting trough that is arranged throughout.
[0011] Furthermore, two cutting grooves are provided between two adjacent confluence areas, and one end of the cutting grooves located on both sides of the same confluence area is connected to a connecting groove extending in the circumferential direction.
[0012] In this way, one end of the two cut-off grooves is connected through the connecting groove, so that only one end of the busbar is connected to the busbar body, so that each busbar can be deformed independently to better weld with the winding core ear, thereby improving the welding quality.
[0013] Furthermore, a dividing strip is formed between two adjacent confluence areas, and a middle portion of the dividing strip is bent toward one side to form a spring sheet.
[0014] In this way, the protruding spring pieces enable the spring pieces of the busbar to contact the cover plate of the housing after assembly, thereby increasing the current passing area between the busbar and the cover plate.
[0015] Furthermore, the edge of the central hole protrudes to one side to form an annular boss, and the outer diameter of the annular boss matches the inner diameter of the core hole of the winding core to be assembled.
[0016] 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.
[0017] Furthermore, the height of the annular boss is 1 to 3 mm.
[0018] A cylindrical battery, characterized by comprising the busbar as described above.
[0019] In summary, the busbar and cylindrical battery of the utility model have the advantages of reasonable structural design, being able to reduce the local strength of the busbar, and being beneficial to improving the safety of the battery. BRIEF DESCRIPTION OF THE DRAWINGS
[0020] Figure 1 and Figure 2 This is a schematic diagram of the structure of Example 1.
[0021] Figure 3 and Figure 4 This is a schematic diagram of the structure of Example 2.
[0022] Figure 5 This is a schematic diagram of the structure of Example 3. DETAILED DESCRIPTION
[0023] The utility model is further described in detail below in conjunction with the embodiments.
[0024] Example 1: Figure 1 and Figure 2 As shown, a busbar comprises a circular busbar 1, wherein the middle of the busbar 1 has a concentrically arranged center hole 2, the outer side of the center hole 2 has a plurality of busbar areas 5 evenly distributed along the circumferential direction, and a cutting groove 3 extending radially is provided between two adjacent busbar areas 5, and the cutting groove 3 is connected to a weakening groove 4 extending circumferentially toward the busbar area 5, and the cutting groove 3 and the weakening groove 4 both penetrate the busbar 1 axially.
[0025] One cutting groove 3 is disposed between two adjacent confluence areas 5 , and weakening grooves 4 are disposed on both sides of the cutting groove 3 . Two weakening grooves 4 are disposed at intervals along the length direction of the cutting groove 3 .
[0026] like Figure 2 As shown, the edge of the center hole 2 protrudes to one side to form an annular boss 7, the outer diameter of the annular boss 7 matches the inner diameter of the core hole of the winding core to be assembled, and the height of the annular boss is 1 to 3 mm. In this way, on the one hand, it is convenient for the electrolyte to be discharged from the center hole, and on the other hand, the annular boss can cooperate with the core hole of the winding core to achieve rapid positioning of the collector plate, greatly improving 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.
[0027] In this embodiment, a weakening groove extending in the circumferential direction is set on the cutting groove between two adjacent confluence areas. Once the internal pressure of the winding core increases, the gas between two adjacent layers of pole pieces on the winding 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 winding core, thereby preventing the internal pressure of the winding core from causing the winding core to expand radially. The above structure reduces the local strength of the confluence plate through the weakening groove, reduces the risk of thermal runaway of the battery, and is conducive to improving battery safety.
[0028] Example 2: Figure 3 and Figure 4As shown, a busbar comprises a circular busbar 1, wherein the middle of the busbar 1 has a concentrically arranged center hole 2, the outer side of the center hole 2 has a plurality of busbar areas 5 evenly distributed along the circumferential direction, and a cutting groove 3 extending radially is provided between two adjacent busbar areas 5, and the cutting groove 3 is connected to a weakening groove 4 extending circumferentially toward the busbar area 5, and the cutting groove 3 and the weakening groove 4 both penetrate the busbar 1 axially.
[0029] There are two cutting grooves 3 between two adjacent busbars 5, and the ends of the cutting grooves 3 located on both sides of the same busbar 5 away from the center hole 2 are connected with a connecting groove extending in the circumferential direction. The connecting groove connects one end of the two cutting grooves, so that only one end of the busbar is connected to the busbar body, so that each busbar can be deformed independently, so as to better adhere to the winding core tab for welding, so as to improve the welding quality.
[0030] The edge of the center hole 2 protrudes to one side to form an annular boss 7. The outer diameter of the annular boss 7 matches the inner diameter of the core hole of the winding core to be assembled, and the height of the annular boss is 1 to 3 mm. In this way, on the one hand, it is convenient for the electrolyte to be discharged from the center hole. On the other hand, the annular boss can cooperate with the core hole of the winding core to achieve rapid positioning of the collector plate, greatly improving production efficiency. At the same time, the annular boss supports 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.
[0031] In this embodiment, a weakening groove extending in the circumferential direction is set on the cutting groove between two adjacent confluence areas. Once the internal pressure of the winding core increases, the gas between two adjacent layers of pole pieces on the winding 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 winding core, thereby preventing the internal pressure of the winding core from causing the winding core to expand radially. The above structure reduces the local strength of the confluence plate through the weakening groove, reduces the risk of thermal runaway of the battery, and is conducive to improving battery safety.
[0032] Embodiment 3: Based on Embodiment 2, the confluence area 5 has a plurality of radially arranged collecting grooves 6, and the collecting grooves 6 penetrate the confluence area 5 in the axial direction, so that the electrolyte can be quickly discharged through the penetrating collecting grooves. A dividing strip is formed between two adjacent confluence areas 5, and the middle part of the dividing strip is bent toward one side to form a spring sheet 8, such as Figure 5 The protruding spring piece enables the spring piece of the busbar to contact the cover plate of the housing after assembly, thereby increasing the overcurrent area of the busbar and the cover plate.
[0033] 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 busbar, characterized in that: The invention comprises a circular busbar (1), wherein the middle of the busbar (1) has a concentrically arranged center hole (2), the outer side of the center hole (2) has a plurality of busbar areas (5) evenly distributed along the circumferential direction, and between two adjacent busbar areas (5) there is a cutting groove (3) extending in the radial direction, the cutting groove (3) is connected to a weakening groove (4) extending in the circumferential direction toward the busbar area (5), and the cutting groove (3) and the weakening groove (4) both penetrate the busbar (1) in the axial direction.
2. The busbar according to claim 1, wherein: At least two weakening grooves (4) are arranged at intervals along the length direction of the cutting groove (3).
3. The busbar according to claim 1, wherein: The confluence area (5) has a plurality of radially arranged collecting grooves (6), and the collecting grooves (6) penetrate the confluence area (5) in the axial direction.
4. The busbar according to claim 1, wherein: Two of the cut-off grooves (3) are provided between two adjacent confluence areas (5), and one end of the cut-off grooves (3) located on both sides of the same confluence area (5) is connected to a connecting groove extending in the circumferential direction.
5. The busbar according to claim 4, wherein: A dividing strip is formed between two adjacent confluence areas (5), and a middle portion of the dividing strip protrudes toward one side and is bent to form a spring sheet.
6. The busbar according to claim 1, wherein: The edge of the central hole (2) protrudes to one side to form an annular boss (7), and the outer diameter of the annular boss (7) matches the inner diameter of the core hole of the winding core to be assembled.
7. The busbar according to claim 6, wherein: The height of the annular boss is 1 to 3 mm.
8. A cylindrical battery, characterized in that: The invention comprises a busbar as claimed in any one of claims 1 to 7.