A double explosion-proof battery shell, cylindrical battery

Abstract

The utility model discloses a kind of double explosion-proof battery shell, cylindrical battery. Cylindrical battery is only composed of end cover, battery cell, shell and current collector plate and adopts double explosion-proof design, not only effectively improve the space utilization of battery cell in the shell, to realize the purpose of battery subsequent capacity and energy density promotion, and additionally, an explosion-proof valve is additionally arranged at the bottom of shell, which can ensure that the battery can normally open pressure relief on the other side while one side explosion-proof fails. It can ensure that the battery can normally open pressure relief on the other side while one side explosion-proof fails, and the safety performance is improved to a certain extent. In addition, the reduction of structural parts also reduces the manufacturing process of the battery, effectively improves the assembly efficiency and yield, while also reduces the manufacturing cost of the battery.

Description

Technical Field

[0001] This utility model belongs to the field of batteries, specifically relating to a double explosion-proof battery shell and a cylindrical battery. Background Technology

[0002] Currently, commercially available 46-series cylindrical lithium-ion batteries typically consist of end caps, sealing studs, bare cells, positive current collectors, negative current collectors, insulating sheets, and a casing. To facilitate current exchange between the battery's internal and external components, the bare cells are generally connected to the casing via positive and negative current collectors. To ensure polarity insulation between the current collectors and the casing, an insulating pad is usually added to one side of either the positive or negative current collector. This results in excessive use of internal space by these structural components, leading to low space utilization of the bare cells and hindering improvements in capacity and energy density. Furthermore, the batteries usually have an explosion-proof structure on one side of the end cap, posing a safety risk of explosion if damaged or malfunctioning. Utility Model Content

[0003] This utility model provides a double explosion-proof battery shell and cylindrical battery, which removes the current collector and insulating sheet on one side, and sets an explosion-proof valve on the sealing nail at the bottom of the shell, forming a double explosion-proof structure with the explosion-proof valve on the end cover, thus solving the problems of low space utilization of bare cells inside the battery and low reliability of explosion-proof pressure relief.

[0004] The technical solution adopted in this utility model is as follows: A dual explosion-proof battery casing includes an end cap and a housing. The end cap has a first explosion-proof valve and electrode terminals. The housing has a cell housing cavity. The end cap is welded to the open end of the cell housing cavity. The closed end of the cell housing cavity has a liquid injection and venting hole and a welding part. The welding part surrounds the liquid injection and venting hole, and a sealing pin is fixed inside the liquid injection and venting hole. The sealing pin includes a second explosion-proof valve. The electrode terminals include a post, a riveting block, an upper plastic, a sealing ring, and a lower plastic. The post passes through the end cap and is riveted to the riveting block. The upper plastic, sealing ring, and lower plastic are fixed together on the end cap. The end of the post facing the cell housing cavity serves as the end to be welded to the current collector. The first and second explosion-proof valves provide dual explosion protection, and only one electrode terminal is used. Correspondingly, when connecting to the cell, only one current collector and insulating sheet are used, reducing the space occupied inside the housing. The dual explosion protection ensures that the battery can be opened normally for pressure relief even if one side fails to provide explosion protection.

[0005] As a preferred embodiment of this invention, the opening pressure of the second explosion-proof valve is 40% to 80% of the opening pressure of the first explosion-proof valve. The second explosion-proof valve will open to release pressure before the first explosion-proof valve. After the first explosion-proof valve opens to release pressure, if the internal pressure of the casing continues to rise and reaches the threshold, the second explosion-proof valve will open to release pressure, ensuring that the battery can open normally to release pressure on the other side while one side fails to prevent explosion.

[0006] In a preferred embodiment of this invention, the welding part is a protrusion on the inner end face of the closed end facing the battery housing cavity, and the protrusion forms a groove structure on the outer end face of the closed end. The welding part is mainly used for welding to the tab end of the battery cell.

[0007] In a preferred embodiment of this utility model, the thickness of the protrusion is greater than the wall thickness of the cell housing cavity and less than the thickness of the closed end; the length of the protrusion is 45% to 90% of the radius of the closed end; and the width of the protrusion is 8 to 28 times the thickness of the closed end.

[0008] In a preferred embodiment of this invention, the sealing nail further includes a protective plate, which is adhered to the outer end face of the second explosion-proof valve. The diameter of the protective plate is smaller than the diameter of the second explosion-proof valve, preventing adverse environmental factors from causing damage or failure to the second explosion-proof valve.

[0009] As a preferred embodiment of this utility model, both the first explosion-proof valve and the second explosion-proof valve include an explosion-proof valve plate. The explosion-proof valve plate has an explosion-proof thinning area at its center, and the explosion-proof thinning area has an explosion-proof groove, which is an explosion-proof groove.

[0010] As a preferred embodiment of this utility model, the thickness of the explosion-proof valve plate of the second explosion-proof valve is 35% to 85% of the wall thickness of the battery cell cavity; the diameter of the protective plate is 70% to 90% of the diameter of the explosion-proof valve plate.

[0011] As a preferred embodiment of this utility model, the end cover includes an end cover plate, an electrode hole is provided in the center of the end cover plate, an electrode terminal is fixed in the electrode hole, an explosion-proof hole is provided at the eccentric position of the end cover plate, and a first explosion-proof valve is fixed in the explosion-proof hole.

[0012] This utility model also provides a cylindrical battery, including a cell, a current collector, and the aforementioned double explosion-proof battery casing. The cell is installed in the cell housing cavity. The current collector is welded to the end of the electrode terminal. One end of the cell is welded to the current collector, and the other end of the cell is welded to the welding part. After the current collector is welded to the end of the end cap, and the cell is welded to the welding part of the casing, the cell is then welded to the current collector. Finally, the end cap is welded to the casing to seal the cell housing cavity.

[0013] As a preferred embodiment of this utility model, the collector plate has a bent structure.

[0014] This novel cylindrical battery consists only of end caps, cells, a casing, and a current collector, and employs a dual explosion-proof design. This not only effectively improves the space utilization of the cells within the battery casing, thereby increasing the battery's capacity and energy density, but also adds an explosion-proof valve at the bottom of the casing. This ensures that even if one side of the battery's explosion-proof mechanism fails, the other side can still open for normal pressure relief, thus enhancing safety. Furthermore, the reduction in structural components also shortens the battery manufacturing process, effectively improving assembly efficiency and yield while lowering manufacturing costs. Attached Figure Description

[0015] 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.

[0016] Figure 1 This is a schematic diagram of the battery casing of this utility model. Figure 1 .

[0017] Figure 2 This is a schematic diagram of the structure of the battery casing of this utility model. Figure 2 .

[0018] Figure 3 This is a cross-sectional view of the battery casing of this utility model.

[0019] Figure 4 This is a schematic diagram of the closed end of the battery casing of this utility model.

[0020] Figure 5 This is a schematic diagram of the end cap structure of this utility model.

[0021] Figure 6 for Figure 4 Sectional view of AA.

[0022] Figure 7 This is a cross-sectional view of the sealing nail of this utility model.

[0023] Figure 8 This is an exploded view of the cylindrical battery of this utility model.

[0024] Figure 9 This is a cross-sectional view of the cylindrical battery of this utility model.

[0025] Figure 10 for Figure 9 A magnified view of a portion of region A in the middle.

[0026] Figure 11 for Figure 9 A magnified view of a portion of region B in the middle. Detailed Implementation

[0027] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0028] This utility model provides a dual explosion-proof battery casing, such as Figure 1 and 2 As shown, it includes an end cap 1 and a housing 2. The end cap 1 is provided with a first explosion-proof valve 11 and an electrode terminal.

[0029] The end cap 1 includes an end cap plate 12. An electrode hole is centrally located on the end cap plate 12, and an electrode terminal is fixed within the electrode hole. An explosion-proof hole is located at an off-center position on the end cap plate 12. A first explosion-proof valve 11 is fixed within the explosion-proof hole. The first explosion-proof valve 11 includes an explosion-proof valve plate 31. An explosion-proof thinning area 32 is located at the center of the explosion-proof valve plate 31. The explosion-proof thinning area 32 has an explosion-proof groove 33, which is an explosion-proof notch. The electrode terminal includes a pole post 13, a riveting block 14, an upper plastic piece 15, a sealing ring 16, and a lower plastic piece 17. The upper plastic piece 15 is disposed on the end cap plate 12. The pole post 13 passes from bottom to top through the lower plastic piece 17, the sealing ring 16, the end cap plate 12, and the upper plastic piece 15 before being riveted to the riveting block 14. Figure 6 and 9 As shown, the upper plastic, sealing ring and lower plastic are fixed together on the end cap, and the end of the pole 13 facing the cell housing cavity is the end to be welded to the current collector.

[0030] like Figure 3 As shown, the housing 2 has a cell receiving cavity 21. After the cell is assembled, the end cap 1 is welded to the open end of the cell receiving cavity 21 to seal the cell receiving cavity. The closed end of the cell receiving cavity 21 has a liquid injection and venting hole 22 and a welding part 23. There are several welding parts, and the welding parts 23 are arranged around the liquid injection and venting hole 22. In this embodiment, the welding part 23 has a protrusion on the inner end face of the closed end facing the battery receiving cavity, and the protrusion has a groove structure on the outer end face of the closed end. The welding part is mainly used to weld to the tab end of the cell.

[0031] The thickness of the protrusion is greater than the wall thickness of the cell housing cavity and less than the thickness of the closed end. The thickness of the protrusion is along the axial direction of the cell housing cavity; the length of the protrusion is 45% to 90% of the radius of the closed end; the length direction of the protrusion is along the radial direction of the closed end; the width of the protrusion is 8 to 28 times the thickness of the closed end. The width direction of the protrusion is perpendicular to the thickness and length directions.

[0032] The electrolyte injection vent 22 serves as both an electrolyte injection channel and a pressure relief channel. A sealing pin 24 is fixed inside the electrolyte injection vent 22. The sealing pin 24 includes a second explosion-proof valve 241 and a protective plate 242. The protective plate 242 is attached to the outer end face of the second explosion-proof valve 241. The diameter of the protective plate is smaller than the diameter of the second explosion-proof valve, preventing adverse environmental factors from damaging or causing the second explosion-proof valve to fail.

[0033] The second explosion-proof valve 241 includes an explosion-proof valve plate 31. An explosion-proof thinning area 32 is provided at the center of the explosion-proof valve plate 31. An explosion-proof groove 33 is provided in the explosion-proof thinning area 32. The explosion-proof groove is an explosion-proof groove.

[0034] Furthermore, the opening pressure of the second explosion-proof valve is 40% to 80% of the opening pressure of the first explosion-proof valve. The thickness of the explosion-proof valve plate of the second explosion-proof valve 241 is 35% to 85% of the wall thickness of the cell housing cavity; the diameter of the protective plate 242 is 70% to 90% of the diameter of the explosion-proof valve plate.

[0035] The second explosion-proof valve will open to release pressure before the first explosion-proof valve. After the first explosion-proof valve opens to release pressure, if the internal pressure of the casing continues to rise and reaches the threshold, the second explosion-proof valve will open to release pressure, ensuring that the battery can open normally to release pressure on the other side while the explosion-proof on one side fails.

[0036] The dual explosion-proof battery casing is mainly used in 46 series cylindrical batteries, but can also be used in other large cylindrical lithium-ion batteries of 46 series and above. It has a cell 4, a current collector 5 and a dual explosion-proof battery casing. The cell has a wound structure, which is formed by stacking and winding the positive electrode sheet, the separator and the negative electrode sheet around the central axis of the winding needle. Polar tabs are set at both ends. In this embodiment, the current collector 5 is welded to the positive tab of the cell. Of course, it can also be welded to the negative tab of the cell. The positive tab of the cell is welded to the welding part.

[0037] First, the current collector 5 is welded to the end of the electrode post facing the cell housing cavity. Then, the current collector is welded to the end cap. Next, the current collector is welded to the positive electrode tab of the cell. Then, the cell is placed into the cell housing cavity. First, the negative electrode tab of the cell is welded to the welding part. Finally, the end cap is welded to the opening end of the cell housing cavity to close the cell housing cavity. In this embodiment, the current collector uses a bent structure.

[0038] The first and second explosion-proof valves provide dual explosion protection, and only one electrode terminal is used. Correspondingly, when connecting to the battery cell, only one current collector and insulating sheet are used, which reduces the space occupied inside the casing. The dual explosion protection ensures that the battery can open normally to release pressure on the other side while the explosion protection on one side fails.

[0039] This utility model's cylindrical battery uses only end caps, cells, a positive or negative current collector, a casing, and a sealing pin with an explosion-proof valve. It eliminates the current collector and insulating sheet on one side, effectively improving the cell's internal space utilization while also promoting improvements in subsequent battery capacity and energy density. Furthermore, the addition of a sealing pin with an explosion-proof valve at the bottom of the casing ensures that even if one side fails to de-explode, the other side can still open for normal pressure relief. This solves the problems of low internal space utilization and unreliable explosion-proof pressure relief. Moreover, the structure is simple to design, easy to manufacture and operate, and can be applied in the cell research and development stage. With improvements, it can be applied to industrial production, showing good prospects for large-scale use.

[0040] In this specification, the terms "an embodiment," "example," "specific example," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the present invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0041] The above description is only a preferred embodiment of the present utility model, but the protection scope of the present utility model is not limited thereto. Any equivalent substitutions or changes made by those skilled in the art within the technical scope disclosed in the present utility model, based on the technical solution and the inventive concept of the present utility model, should be included within the protection scope of the present utility model.

Claims

1. A double explosion-proof battery casing, comprising an end cap (1) and a casing (2), characterized in that: The end cap (1) is provided with a first explosion-proof valve (11) and an electrode terminal. The housing (2) is provided with a cell receiving cavity (21). The end cap (1) is welded to the open end of the cell receiving cavity (21) of the housing (2). The closed end of the cell receiving cavity (21) is provided with a liquid injection vent hole (22) and a welding part (23). The welding part (23) is arranged around the liquid injection vent hole (22). A sealing nail (24) is fixed inside the liquid injection vent hole (22). The sealing nail (24) includes a second explosion-proof valve (241).

2. The dual explosion-proof battery casing according to claim 1, characterized in that: The opening pressure of the second explosion-proof valve is 40% to 80% of the opening pressure of the first explosion-proof valve.

3. The dual explosion-proof battery casing according to claim 1, characterized in that: The welded part (23) is a protrusion with the inner end face of the closed end facing the battery cavity, and the protrusion has a groove structure on the outer end face of the closed end.

4. The dual explosion-proof battery casing according to claim 3, characterized in that: The thickness of the protrusion is greater than the wall thickness of the cell housing cavity and less than the thickness of the closed end; the length of the protrusion is 45% to 90% of the radius of the closed end; the width of the protrusion is 8 to 28 times the thickness of the closed end.

5. The dual explosion-proof battery casing according to any one of claims 1-4, characterized in that: The sealing nail (24) also includes a protective plate (242), which is attached to the outer end face of the second explosion-proof valve (241).

6. The dual explosion-proof battery casing according to claim 5, characterized in that: The first explosion-proof valve (11) and the second explosion-proof valve (241) both include an explosion-proof valve plate (31), and an explosion-proof thinning area (32) is provided at the center of the explosion-proof valve plate (31), and an explosion-proof groove (33) is provided in the explosion-proof thinning area (32).

7. The dual explosion-proof battery casing according to claim 6, characterized in that: The explosion-proof valve plate of the second explosion-proof valve (241) has a thickness of 35% to 85% of the wall thickness of the cell cavity; the diameter of the protective plate (242) is 70% to 90% of the diameter of the explosion-proof valve plate.

8. The dual explosion-proof battery casing according to claim 1, characterized in that: The end cap (1) includes an end cap plate (12), an electrode hole is provided in the center of the end cap plate (12), and an electrode terminal is fixed in the electrode hole; an explosion-proof hole is provided at the eccentric position of the end cap plate (12), and a first explosion-proof valve (11) is fixed in the explosion-proof hole.

9. A cylindrical battery, characterized in that: It includes a battery cell (4), a current collector (5), and a double explosion-proof battery casing as described in any of claims 1-8; the battery cell (4) is installed in the battery cell housing cavity, the current collector (5) is welded to the end of the electrode terminal, one end of the battery cell is welded to the current collector, and the other end of the battery cell is welded to the welding part (23).

10. The cylindrical battery according to claim 9, characterized in that: The aforementioned manifold has a bent structure.

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