High-magnification cylindrical battery

Abstract

The utility model discloses a high-magnification cylindrical battery, which comprises a shell with at least one open end and a roll core arranged in the shell, a confluence sheet is welded at one end of the roll core facing the open end, and a cover plate is matched on the open end; the bus bar is characterized in that the bus bar is integrally circular, the edge of the bus bar extends in the direction away from the roll core to form a turned edge, the outer diameter of the turned edge is matched with the inner diameter of the shell, and the turned edge is attached to the inner wall of the shell; the side, facing the shell, of the cover plate is provided with a protruding part which is concentrically arranged, the outer diameter of the protruding part is matched with the inner diameter of the turned-over edge, and the turned-over edge is embedded between the protruding part and the shell and connected with the protruding part and the shell in a welded mode. The utility model has the advantages that the structural design is reasonable, the welding area can be increased, and the over-current capability is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, and particularly to a high-rate cylindrical battery. Background Art

[0002] Large cylindrical batteries have larger capacity and energy density than small cylindrical batteries. High-rate batteries occupy the main application fields in consumer and power batteries. At present, the structural components of large cylindrical batteries are connected conductively by welding, but the welding area between the bus bar and the tab is limited, resulting in limited current passing ability. Often, due to small overcurrent, the structural components of the battery heat up, and even the structural components are melted due to high temperature, affecting the service life of the battery. Summary of the Utility Model

[0003] Aiming at the deficiencies of the above-mentioned prior art, the technical problem to be solved by the utility model is: how to provide a high-rate cylindrical battery with reasonable structural design, which can increase the welding area and improve the overcurrent ability.

[0004] To solve the above technical problem, the utility model adopts the following technical scheme:

[0005] A high-rate cylindrical battery includes a housing with at least one open end and a winding core arranged in the housing. A bus bar is welded to one end of the winding core facing the open end, and a cover plate is fitted to the open end. It is characterized in that the bus bar is circular as a whole, and a flanging is formed at the edge extending in the direction away from the winding core. The outer diameter of the flanging matches the inner diameter of the housing and is in contact with the inner wall of the housing. The cover plate has a concentric protrusion on the side facing the housing. The outer diameter of the protrusion matches the inner diameter of the flanging. The flanging is embedded between the protrusion and the housing and is welded to both of them.

[0006] In the above structure, the bus bar is welded to the winding core, and the flanging of the bus bar is embedded in the gap between the cover plate and the housing, so that the cover plate, the bus bar and the housing can have good contact, and the current-carrying area can be increased, thereby reducing heat generation.

[0007] Further, the bus bar is welded to the tab of the winding core, and a strip-shaped welding area is formed between them extending along the radial direction of the bus bar. A plurality of strip-shaped welding areas are arranged circumferentially.

[0008] In this way, the tabs on each layer can be in contact with the back of the bus bar and welded to it, which can not only increase the welding area, but also shorten the current path of each layer of electrode sheets, reduce the resistance, and improve the overcurrent ability.

[0009] Further, the bus bar has a groove extending along the radial direction on the side facing away from the winding core, and the bottom of the groove forms the strip-shaped welding area.

[0010] In this way, the welding area can be thinned to make the welding more reliable, and the welding position can be located at the same time.

[0011] Furthermore, the middle part of the bus bar has a central hole arranged concentrically, and one end of the groove is close to the flanging and the other end is close to the central hole.

[0012] Furthermore, the bottom of the groove protrudes relatively towards the side of the core.

[0013] In this way, the bottom of the groove can better fit the tab. In addition, there is still a gap between the bus bar and the tab between two adjacent grooves, thus facilitating the flow of the electrolyte.

[0014] Furthermore, the bus bar is provided with a pressure relief hole arranged through.

[0015] Furthermore, an explosion-proof valve is arranged on the cover plate, and the explosion-proof valve is arranged opposite to the pressure relief hole.

[0016] Furthermore, the cover plate is provided with an explosion-proof hole arranged through, and the inner end of the explosion-proof hole has a counterbore, and the explosion-proof valve is an explosion-proof sheet welded on the counterbore.

[0017] Furthermore, the inner side of the cover plate has a boss arranged concentrically, and the diameter of the boss matches the diameter of the central hole; a liquid injection hole arranged through is provided in the middle of the boss, and a sealing nail is arranged in cooperation with the liquid injection hole.

[0018] Furthermore, both ends of the housing are open, and an end cover is arranged at the other end, and an insulating pad in the shape of a disc is arranged on the inner side of the end cover; a through hole for accommodation is provided in the middle of the end cover and the insulating pad, and a pole column is riveted insulatively; a bus bar plate is welded on the side of the core facing the end cover, and the pole column is welded and connected to the bus bar plate.

[0019] To sum up, the utility model has the advantages of reasonable structural design, capable of increasing the welding area and improving the overcurrent capacity, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a schematic exploded view of the utility model.

[0021] Figure 2 and Figure 3 is a schematic structural view of the cover plate and the bus bar.

[0022] Figure 4 is another schematic structural view of the bus bar. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The utility model is further described in detail below in conjunction with the embodiments.

[0024] When implementing: Figures 1 to 3 As shown, a high-rate cylindrical battery comprises a shell 1 with open ends and a winding core 2 arranged in the shell 1, one end of the winding core 2 is welded with a busbar 3 and matched with a cover plate 4; the other end of the shell 1 is provided with an end cover 5, and the inner side of the end cover 5 is provided with a disc-shaped insulating pad 6; the middle part of the end cover 5 and the insulating pad 6 has a through-set clearance hole, and a pole 7 is riveted in an insulated manner; the side of the winding core 2 facing the end cover 5 is welded with a busbar 8, and the pole 7 is welded to the busbar 8.

[0025] The busbar 3 is circular in shape as a whole, and the edge extends in the direction away from the winding core 2 to form a flange 31, the outer diameter of the flange 31 matches the inner diameter of the shell 1, and is in contact with the inner wall of the shell 1; the cover plate 4 has a concentrically arranged protrusion 41 on the side facing the shell 1, the outer diameter of the protrusion 41 matches the inner diameter of the flange 31, and the flange 31 is embedded between the protrusion 41 and the shell 1, and is welded to the two. The busbar 3 is welded to the tab of the winding core 2, and there is a strip welding area extending in the radial direction of the busbar 3 between the two, and multiple strip welding areas are arranged along the circumferential direction.

[0026] The flange of the busbar is embedded in the gap between the cover plate and the shell, so that the cover plate, busbar and shell have good contact, and the current flow area can be increased, thereby reducing heat generation. In addition, by arranging the welding area in the radial direction, the tabs on each layer can be in contact with the back of the busbar and welded together, which can increase the welding area, shorten the current path of each layer of pole pieces, reduce resistance, and improve current capacity.

[0027] In specific implementation, the following busbar structure may also be used, such as Figure 4 As shown, the side of the busbar 3 facing away from the winding core 2 has a groove 34 extending in the radial direction, and the bottom of the groove 34 forms the strip-shaped welding area. The welding area can be accurately located by the groove. At the same time, the bottom of the groove 34 is relatively protruding toward the side of the winding core 2. This allows the bottom of the groove to better fit the pole ear. In addition, there is still a gap between the busbar and the pole ear between two adjacent grooves, which facilitates the flow of electrolyte.

[0028] The middle part of the bus bar 3 has a centrally arranged central hole 32, one end of the groove 34 is close to the flanging 31, and the other end is close to the central hole 32. The bus bar 3 is provided with a pressure relief hole 33 penetrating therethrough. The cover plate 4 is provided with an explosion-proof valve 42, and the explosion-proof valve 42 is arranged opposite to the pressure relief hole 33. In this embodiment, the cover plate 4 has an explosion-proof hole penetrating therethrough, and the inner end of the explosion-proof hole has a sink, and the explosion-proof valve 42 is an explosion-proof sheet welded on the sink.

[0029] One side of the cover plate 4 facing inwards has a centrally arranged boss 43, and the diameter of the boss 43 matches the diameter of the central hole; the middle part of the boss 43 has a liquid injection hole penetrating therethrough, and a sealing nail is arranged in cooperation with the liquid injection hole. Through the boss 43, it can cooperate with the central hole on the winding core and the bus bar to ensure coaxial assembly and guarantee the assembly accuracy.

[0030] The above are only the preferred embodiments of the present utility model, and the present utility model is not limited thereto. Any modifications, equivalent replacements, and improvements made within the spirit and principle of the present utility model shall be included within the protection scope of the present utility model.

Claims

1. A high-rate cylindrical battery, comprising a housing (1) with at least one open end and a wound core (2) disposed within the housing (1), a current collector tab (3) is welded to one end of the wound core (2) facing the open end, and a cover plate (4) is fitted to the open end; characterized in that, The bus bar (3) is circular as a whole, and a flanging (31) is formed on the edge extending in the direction away from the core (2). The outer diameter of the flanging (31) matches the inner diameter of the housing (1) and is in contact with the inner wall of the housing (1). On the side of the cover plate (4) facing the housing (1), there are concentrically arranged protrusions (41). The outer diameter of the protrusions (41) matches the inner diameter of the flanging (31). The flanging (31) is embedded between the protrusions (41) and the housing (1) and is welded to both of them.

2. The high-rate cylindrical battery according to claim 1, wherein The bus bar (3) is welded to the tab of the core (2), and there are a plurality of strip-shaped welding areas extending radially along the bus bar (3) and arranged circumferentially.

3. The high-rate cylindrical battery according to claim 2, wherein, On the side of the bus bar (3) facing away from the core (2), there is a groove (34) extending radially. The bottom of the groove (34) forms the strip-shaped welding area.

4. The high-rate cylindrical battery according to claim 3, wherein In the middle of the bus bar (3), there is a concentrically arranged central hole (32). One end of the groove (34) is close to the flanging (31), and the other end is close to the central hole (32).

5. The high-rate cylindrical battery according to claim 3, wherein The bottom of the groove (34) protrudes relatively towards the side of the core (2).

6. The high-rate cylindrical battery according to claim 1, wherein, The bus bar (3) is provided with a vent hole (33) penetrating through it.

7. The high-rate cylindrical battery according to claim 6, wherein, An explosion-proof valve (42) is provided on the cover plate (4), and the explosion-proof valve (42) is arranged directly opposite to the vent hole (33).

8. The high-rate cylindrical battery according to claim 7, wherein There is a through explosion-proof hole on the cover plate (4). The inner end of the explosion-proof hole has a sunk groove, and the explosion-proof valve (42) is an explosion-proof sheet welded to the sunk groove.

9. The high-rate cylindrical battery according to claim 4, wherein, On the inner side of the cover plate (4), there are concentrically arranged bosses (43). The diameter of the bosses (43) matches the diameter of the central hole. A liquid injection hole is provided through the middle of the bosses (43), and a sealing nail is arranged in cooperation with the liquid injection hole.

10. The high-rate cylindrical battery according to claim 1, wherein Both ends of the housing (1) are open, and an end cover (5) is provided at the other end. An insulating pad (6) in the shape of a disc is arranged on the inner side of the end cover (5). A through relief hole is provided in the middle of the end cover (5) and the insulating pad (6), and a pole column (7) is riveted insulatedly. A bus bar plate (8) is welded to the side of the core (2) facing the end cover (5), and the pole column (7) is welded to the bus bar plate (8).

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