Battery shell structure and cylindrical battery

Abstract

The utility model discloses a battery shell structure and a cylindrical battery, the battery shell structure comprises a shell, the whole shell is cylindrical, one end of the shell is open, the bottom of the shell is provided with a disc-shaped groove which is formed by recessing inwards, the bottom of the groove is provided with a central hole which is concentrically arranged, and the central hole is communicated with the shell. The outer side of the center hole is provided with a plurality of confluence areas which are evenly distributed in the circumferential direction, and a cut-off groove which extends in the radial direction is formed between every two adjacent confluence areas. A sealing plate is arranged on the groove in a matched mode, and the diameter of the sealing plate is matched with the diameter of the groove. The battery shell structure and the cylindrical battery disclosed by the utility model have the advantages of being reasonable in structural design, capable of simplifying a welding structure between the roll core and the shell, beneficial to reducing resistance and the like.

Description

Technical Field

[0001] The utility model relates to the technical field of lithium batteries, in particular to a battery shell structure 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. The typical cylindrical battery structure mainly includes a shell, a core, and a cover. The core is set in the shell, and the busbars are welded at both ends. The busbars are then welded to the shell and the cover respectively. The current between the core and the shell needs to be conducted through the welding parts between the core and the busbar, and between the busbar and the cover. Multi-stage welding not only increases the welding requirements, but also increases the resistance. 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 battery shell structure and a cylindrical battery with a reasonable structural design, which can simplify the welding structure between the winding core and the shell and is conducive to reducing the resistance.

[0004] In order to solve the above technical problems, the utility model adopts the following technical solutions:

[0005] A battery shell structure, characterized in that it includes a shell that is generally cylindrical and open at one end, the bottom of the shell has a groove that is disc-shaped and inwardly concave, the bottom of the groove has a concentrically arranged center hole, the outer side of the center hole has a plurality of confluence areas evenly distributed along the circumferential direction, and a cutting groove extending radially is provided between two adjacent confluence areas; the groove is matched with a sealing plate, and the diameter of the sealing plate matches the diameter of the groove.

[0006] When in use, after welding the busbar and cover plate at one end of the winding core, place the winding core into the shell, and use penetration welding to weld the other end of the winding core to the busbar area at the bottom of the groove, and then weld the sealing plate to the groove. Since the groove and the shell are integrated, the winding core is directly connected to the shell after being welded to the bottom of the groove, thereby simplifying the welding structure between the two. The current is directly conducted to the shell through the bottom plate of the groove, which is beneficial to reduce the internal resistance.

[0007] Furthermore, the bottom thickness of the groove is smaller than the thickness of the shell.

[0008] In this way, the bottom of the groove can have better deformation ability, so as to fit the pole ear welding, which is beneficial to ensure the welding quality.

[0009] Furthermore, the bottom of the shell has a limiting groove connected with the groove, the diameter of the limiting groove is consistent with the diameter of the sealing plate, and the depth of the limiting groove is consistent with the thickness of the sealing plate.

[0010] In this way, after the sealing plate and the limiting groove are matched, they can be flush with the bottom of the shell.

[0011] Furthermore, the cut-off groove is connected to a weakening groove extending circumferentially toward the confluence area.

[0012] In this way, 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.

[0013] Furthermore, the sealing plate has notches arranged in a ring shape.

[0014] In this way, once the internal pressure of the battery cell is too high, the sealing plate can be broken open through the notch to release the pressure.

[0015] Furthermore, at least two weakening grooves are arranged at intervals along the length direction of the cutting groove.

[0016] 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.

[0017] A cylindrical battery, characterized by comprising the battery casing structure as described above.

[0018] In summary, the battery shell structure and cylindrical battery of the present invention have the advantages of reasonable structural design, being able to simplify the welding structure between the winding core and the shell, and being conducive to reducing resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Schematic diagram of the shell decomposition structure of this embodiment.

[0020] Figure 2 Schematic diagram of the shell structure of this embodiment. DETAILED DESCRIPTION

[0021] The utility model is further described in detail below in conjunction with the embodiments.

[0022] When implementing: Figure 1 and Figure 2 As shown, a battery shell structure includes a shell 1 that is cylindrical as a whole and open at one end, the bottom of the shell 1 has a groove 2 that is formed inwardly concave in a disc shape, the bottom thickness of the groove 2 is less than the thickness of the shell 1, and has a concentrically arranged center hole 3, the outer side of the center hole 3 has a plurality of confluence areas 4 that are evenly distributed along the circumference, and a cutting groove 5 that extends radially is provided between two adjacent confluence areas 4; the groove 2 is matched with a sealing plate 6, and the diameter of the sealing plate 6 matches the diameter of the groove 2. In order to allow the sealing plate to be flush with the bottom surface of the shell 1, the bottom of the shell 1 has a limiting groove 7 that is connected to the groove 2, the diameter of the limiting groove 7 is consistent with the diameter of the sealing plate 6, and the depth is consistent with the thickness of the sealing plate 6. During assembly, the sealing plate 6 is matched with the limiting groove 7 and welded together.

[0023] In this embodiment, there are two cutting grooves 5 between two adjacent confluence areas 4, and one end of the cutting grooves 5 located on both sides of the same confluence area 4 is connected to a connecting groove extending in the circumferential direction. The cutting grooves 5 are connected to a weakening groove 8 extending in the circumferential direction toward the confluence area 4. Figure 1 As shown, at least two weakening grooves 8 are arranged at intervals along the length direction of the cutting groove 5 .

[0024] 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 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.

[0025] Furthermore, the sealing plate 6 has a notch 61 arranged in a ring shape. Once the pressure inside the battery core is too high, the sealing plate can be opened through the notch to release the pressure.

[0026] 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 battery housing structure, characterized in that: The invention comprises a shell (1) which is cylindrical in shape and open at one end, the bottom of the shell (1) having a disc-shaped inwardly concave groove (2), the bottom of the groove (2) having a concentrically arranged center hole (3), the outer side of the center hole (3) having a plurality of circumferentially evenly distributed confluence areas (4), and a radially extending cutting groove (5) between two adjacent confluence areas (4); the groove (2) being matched with a sealing plate (6), the diameter of the sealing plate (6) matching the diameter of the groove (2).

2. The battery housing structure according to claim 1, characterized in that: The bottom thickness of the groove (2) is smaller than the thickness of the shell (1).

3. The battery housing structure according to claim 1, characterized in that: The bottom of the housing (1) has a limiting groove (7) arranged to be connected with the groove (2); the diameter of the limiting groove (7) is consistent with the diameter of the sealing plate (6), and the depth is consistent with the thickness of the sealing plate (6).

4. The battery housing structure according to claim 1, characterized in that: The cut-off groove (5) is connected to a weakening groove (8) extending in the circumferential direction toward the confluence area (4).

5. The battery housing structure according to claim 4, characterized in that: The sealing plate (6) has notches arranged in a ring shape.

6. The battery housing structure according to claim 4, characterized in that: At least two weakening grooves (8) are arranged at intervals along the length direction of the cutting groove (5).

7. The battery housing structure according to claim 4, characterized in that: Two of the cut-off grooves (5) are provided between two adjacent confluence areas (4), and one end of the cut-off grooves (5) located on both sides of the same confluence area (4) is connected to a connecting groove extending in the circumferential direction.

8. A cylindrical battery, characterized in that: The invention comprises a battery casing structure as claimed in any one of claims 1 to 7.

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