Helium detection device

Abstract

This utility model relates to the field of airtightness testing technology, and more particularly to a helium detection device, including a cavity and an anti-deformation unit. The cavity houses an aluminum-cased battery to be tested. The battery has two opposing first sidewalls and two opposing second sidewalls, with the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls. The anti-deformation unit is disposed on the sidewall of the cavity and can respectively press against the two first sidewalls and / or the two second sidewalls. By using the anti-deformation unit to press against the two first sidewalls and / or the two second sidewalls, this helium detection device prevents deformation of the sidewalls of the aluminum-cased battery during the helium filling and pressurization process, thereby increasing the helium detection pressure to greater than 10 kPa. This effectively detects defects such as welding defects, dents, and pinholes in the battery, ensuring the quality and safety of the battery cell casing.

Description

Technical Field

[0001] This utility model relates to the field of airtightness testing technology, and in particular to a helium detection device. Background Technology

[0002] Lithium-ion battery cells require helium testing during production, such as after welding around the perimeter of prismatic cells. Laser welding is used for this process, which introduces defects such as craters, pits, and pinholes. These areas have low mechanical strength and can only withstand low pressure. Helium testing requires a pressure greater than 10 kPa to effectively detect these defects. However, with existing helium testing equipment, once the pressure exceeds 10 kPa, the cell casing expands and deforms significantly, altering the position of the gas tube insertion and deforming the insertion hole, making further testing impossible. If these defects cannot be effectively detected in the welded area, the defective cell casing can leak in downstream processes, leading to battery failure at the customer's end. Utility Model Content

[0003] The purpose of this invention is to provide a helium detection device that can detect defects such as blast points, pits, and pinholes in the welding area to ensure the quality and safety of the battery cell casing.

[0004] To achieve this objective, the present invention adopts the following technical solution:

[0005] A helium detection device is provided, comprising:

[0006] A cavity for accommodating an aluminum-cased battery to be tested, the aluminum-cased battery having two first sidewalls and two second sidewalls arranged opposite to each other, the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls;

[0007] An anti-deformation unit is disposed on the side wall of the cavity, and the anti-deformation unit is capable of pressing against the two first side walls and / or the two second side walls respectively.

[0008] Optionally, the anti-deformation unit includes a first driving member and two first pressing plates. The two first pressing plates can press against the two first sidewalls respectively. One of the first pressing plates is connected to the output end of the first driving member. The first driving member can drive the first pressing plate to move closer to or away from the other first pressing plate.

[0009] And / or, the anti-deformation unit includes a second driving member and two second pressing plates, the two second pressing plates being able to press against the two second sidewalls respectively, one of the second pressing plates being connected to the output end of the second driving member, and the second driving member being able to drive the second pressing plate to move closer to or away from the other second pressing plate.

[0010] Optionally, the anti-deformation unit further includes a first connecting rod, which is movably inserted through a first assembly through hole on the side wall of the cavity, and the first connecting rod is sealed to the first assembly through hole; one end of the first connecting rod is connected to the output end of the first driving member, and the other end is connected to a first pressure plate;

[0011] Optionally, the anti-deformation unit further includes a second connecting rod, which is movably inserted through a second assembly through hole on the side wall of the cavity, and the second connecting rod is sealed to the second assembly through hole; one end of the second connecting rod is connected to the output end of the second driving member, and the other end is connected to a second pressure plate.

[0012] Optionally, it also includes a pressure sensor disposed on the anti-deformation unit for measuring the pressure exerted by the anti-deformation unit on the first sidewall and / or on the second sidewall.

[0013] Optionally, the two first sidewalls are arranged opposite each other along a first direction, and along the first direction, the width of the second sidewall is a, and the width of the second pressure plate is b, satisfying a > b;

[0014] And / or, the two second sidewalls are disposed opposite each other along the second direction, and along the second direction, the width of the first sidewall is c, and the width of the first pressure plate is d, satisfying d > c.

[0015] Optionally, the first pressure plate includes a boss structure and a pressing plate, the pressing plate being able to contact and press against the first sidewall, and the boss structure being disposed on the surface of the pressing plate away from the first sidewall.

[0016] Optionally, the area of ​​the boss structure is smaller than the area of ​​the pressing plate, and the height of the boss structure protruding from the pressing plate is e, where 0.3mm≤e≤0.7mm.

[0017] Optionally, the helium detection device further includes a helium detection vacuum unit, which includes a vacuum pumping device and a helium filling device. The cavity has a first passage and a second passage. One end of the first passage and the second passage are both connected to the vent of the aluminum-cased battery to be tested. The other end of the first passage is connected to the vacuum pumping device, and the other end of the second passage is connected to the helium filling device.

[0018] And / or, the cavity is further provided with a third passage, one end of which is connected to the vacuum pumping device and the other end is connected to the inner cavity of the cavity.

[0019] Optionally, the helium detection vacuum unit further includes a detection tube and a helium detector, wherein the detection tube is used to connect the third passage and the vacuum pumping device, and the gas inlet of the helium detector is connected to the detection tube.

[0020] The beneficial effects of this utility model are:

[0021] This invention provides a helium detection device, including a cavity and an anti-deformation unit. The cavity houses an aluminum-cased battery to be inspected. The battery has two opposing first sidewalls and two opposing second sidewalls, with the area of ​​the first sidewalls being larger than the area of ​​the second sidewalls. The anti-deformation unit is disposed on the sidewall of the cavity and can press against the two first sidewalls and / or the two second sidewalls respectively. By using the anti-deformation unit to press against the two first sidewalls and / or the two second sidewalls, this helium detection device prevents deformation of the sidewalls of the aluminum-cased battery during helium filling and pressurization, thereby increasing the helium detection pressure to greater than 10 kPa. This effectively detects defects such as welding defects, dents, and pinholes in the battery, ensuring the quality and safety of the battery cell casing. Attached Figure Description

[0022] Figure 1 This is a top view of a portion of the structure of the helium detection device provided in this embodiment of the present invention;

[0023] Figure 2 This is a partial structural cutaway view of the helium detection device provided in this embodiment of the present invention;

[0024] Figure 3 This is a first-view structural schematic diagram of the first pressure plate provided in this embodiment of the utility model;

[0025] Figure 4 This is a structural schematic diagram of the first pressure plate provided in an embodiment of the present invention from a second perspective.

[0026] In the picture:

[0027] 1. Cavity; 11. Upper cavity; 111. First passage; 112. Second passage; 113. Third passage; 12. Lower cavity;

[0028] 2. First pressure plate; 21. Boss structure; 22. Press plate;

[0029] 3. Second pressure plate; 4. First driving component; 5. Second driving component; 6. First connecting rod; 7. Second connecting rod;

[0030] 8. Helium vacuum detection unit; 81. Detection tube; 82. Helium detector; 83. Helium pressure gauge; 84. First vacuum pressure gauge; 85. Second vacuum pressure gauge; 86. Solenoid valve;

[0031] 9. First fixing block; 10. Second fixing block;

[0032] 100. Aluminum-cased battery to be inspected; 101. First sidewall; 102. Second sidewall; 103. Injection hole. Detailed Implementation

[0033] The technical solution of this utility model will be further described below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely for explaining this utility model and not for limiting it. Furthermore, it should be noted that, for ease of description, only the parts related to this utility model are shown in the drawings, not all of them.

[0034] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections or detachable connections; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0035] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0036] Lithium-ion battery cells require helium testing during production, such as after welding around the perimeter of prismatic cells. Laser welding is used for this process, which introduces defects such as craters, pits, and pinholes. These areas have low mechanical strength and can only withstand low pressure. Helium testing requires a pressure greater than 10 kPa to effectively detect these defects. However, with existing helium testing equipment, once the pressure exceeds 10 kPa, the cell casing expands and deforms significantly, altering the position of the gas tube insertion and deforming the insertion hole, making further testing impossible. If these defects cannot be effectively detected in the welded area, the defective cell casing can leak in downstream processes, leading to battery failure at the customer's end.

[0037] Therefore, this embodiment provides a helium detection device to solve the above problems. The helium detection device can detect whether there are defects such as blast points, pits, and pinholes in the welding area, so as to ensure the quality and safety of the battery cell casing.

[0038] like Figures 1-4 As shown, the helium detection device of this embodiment includes a cavity 1 and an anti-deformation unit. The cavity 1 is used to house an aluminum-cased battery 100 to be tested. The aluminum-cased battery 100 has two opposing first sidewalls 101 and two opposing second sidewalls 102, with the area of ​​the first sidewalls 101 being larger than the area of ​​the second sidewalls 102. The anti-deformation unit is disposed on the sidewall of the cavity 1, and the anti-deformation unit is capable of pressing against the two first sidewalls 101 and / or the two second sidewalls 102 respectively.

[0039] This helium detection device, by setting anti-deformation units to press against the two first sidewalls 101 and / or the two second sidewalls 102, can prevent the sidewalls of the aluminum-cased battery 100 under test from deforming during the process of filling and pressurizing the aluminum-cased battery 100 with helium. This allows the helium detection pressure to be increased to more than 10 kPa, which can effectively detect whether there are defects such as welding craters, pits, and pinholes on the aluminum-cased battery 100 under test, thus ensuring the quality and safety of the battery cell casing.

[0040] Optionally, in this embodiment, the anti-deformation unit includes two first pressing plates 2, which can respectively press against two first sidewalls 101. Optionally, in this embodiment, the anti-deformation unit includes two second pressing plates 3, which can respectively press against two second sidewalls 102. The first pressing plates 2 and the second pressing plates 3 can thus provide anti-deformation function for all four sidewalls of the aluminum-cased battery 100 under inspection.

[0041] In this embodiment, the anti-deformation unit includes two first pressing plates 2 and two second pressing plates 3. In other embodiments, only the first pressing plates 2 or only the second pressing plates 3 may be provided to press against the two relatively weak side walls of the aluminum-cased battery 100 under inspection, preventing severe deformation of the weak side walls.

[0042] To make the distance between the two first pressure plates 2 adjustable to accommodate rectangular housings of different sizes, the anti-deformation unit may optionally include a first driving member 4. One first pressure plate 2 is connected to the output end of the first driving member 4, and the first driving member 4 can drive the first pressure plate 2 to move closer to or away from the other first pressure plate 2. Optionally, the first driving member 4 is a cylinder.

[0043] Since the internal volume of cavity 1 should not be too large to improve vacuuming efficiency, the first driving component 4 is located outside cavity 1. Optionally, the anti-deformation unit also includes a first connecting rod 6, which is movably inserted through a first assembly through hole on the side wall of cavity 1, and the first connecting rod 6 and the first assembly through hole are sealed together. One end of the first connecting rod 6 is connected to the output end of the first driving component 4, and the other end is connected to a first pressure plate 2. Optionally, a sealing bearing is provided between the first connecting rod 6 and the first assembly through hole to ensure a constant seal between them, and the first connecting rod 6 is movable. Alternatively, after the first connecting rod 6 moves to a suitable position to press against the aluminum-cased battery 100 under test, sealing material can be used to seal the gap between the first connecting rod 6 and the first assembly through hole to further ensure the sealing of cavity 1 and prevent the detected helium leakage from being lower than the actual helium leakage.

[0044] To make the distance between the two second pressure plates 3 adjustable to accommodate rectangular housings of different sizes, the anti-deformation unit may optionally include a second driving member 5. One second pressure plate 3 is connected to the output end of the second driving member 5, and the second driving member 5 can drive the second pressure plate 3 to move closer to or away from the other second pressure plate 3. Optionally, the second driving member 5 is a cylinder.

[0045] Since the internal volume of cavity 1 should not be too large to improve vacuuming efficiency, the second driving component 5 is also located outside cavity 1. Optionally, the anti-deformation unit also includes a second connecting rod 7, which is movably inserted through a second assembly through hole on the side wall of cavity 1, and the second connecting rod 7 and the second assembly through hole are sealed together. One end of the second connecting rod 7 is connected to the output end of the second driving component 5, and the other end is connected to a second pressure plate 3. Optionally, a sealing bearing is also provided between the second connecting rod 7 and the second assembly through hole to ensure that they are always sealed, and the second connecting rod 7 is movable. Alternatively, after the second connecting rod 7 moves to a suitable position to press against the aluminum-cased battery 100 under test, sealing material can be used to seal the gap between the second connecting rod 7 and the second assembly through hole to further ensure the sealing of cavity 1 and prevent the detected helium leakage from being lower than the actual helium leakage.

[0046] Optionally, the first pressing plate 2 not connected to the first driving component 4 is connected to the first fixing block 9 via a third connecting rod. The first fixing block 9 can be fixed to the test bench by means of screws or other methods to ensure that the position of this first pressing plate 2 remains unchanged. Optionally, the first fixing block 9 is located outside the cavity 1, and the third connecting rod is movably and sealed through the third assembly through hole of the cavity 1. When the position of one first pressing plate 2 remains unchanged, and the other first pressing plate 2 continuously presses against the first side wall 101 under the drive of the first driving component 4, the pressing action of the two first side walls 101 of the aluminum shell battery 100 under test is consistent.

[0047] Optionally, the helium detection device also includes a pressure sensor disposed on the anti-deformation unit for measuring the pressure exerted by the anti-deformation unit on the first sidewall 101 and / or on the second sidewall 102.

[0048] The pressure sensor includes a first pressure sensor (not shown in the figure), which is used to measure the pressure exerted by the first pressure plate 2 on the first sidewall 101. The detection end of the first pressure sensor can be located between any one of the first pressure plates 2 and the first sidewall 101.

[0049] Optionally, the second pressing plate 3, which is not connected to the second driving member 5, is connected to the second fixing block 10 via a fourth connecting rod. The second fixing block 10 can be fixed to the test bench by means of screws or other methods to ensure that the position of this second pressing plate 3 remains unchanged. Optionally, the second fixing block 10 is located outside the cavity 1, and the fourth connecting rod is movably sealed through the fourth assembly through hole of the cavity 1. When the position of one second pressing plate 3 remains unchanged, and the other second pressing plate 3 continuously presses against the second side wall 102 under the drive of the second driving member 5, the pressing action of the two second side walls 102 of the aluminum shell battery 100 under test is consistent.

[0050] Optionally, the anti-deformation unit also includes a second pressure sensor (not shown in the figure), which is used to measure the pressure exerted by the second pressure plate 3 on the second sidewall 102. The detection end of the second pressure sensor can be located between any one of the second pressure plates 3 and the second sidewall 102.

[0051] Optionally, the two first sidewalls 101 are arranged opposite each other along a first direction. Along the first direction, the width of the second sidewall 102 is a, and the width of the second pressing plate 3 is b, satisfying a > b. This helps to prevent the second pressing plate 3 from being too wide and interfering with the first pressing plate 2. Optionally, the projection of the second pressing plate 3 onto the second sidewall 102 coincides with the centerline of the second sidewall 102 along its width direction.

[0052] Optionally, the two second sidewalls 102 are arranged opposite each other along a second direction. Along the second direction, the width of the first sidewall 101 is c, and the width of the first pressing plate 2 is d, satisfying d > c. This helps to ensure that all parts of the first sidewall 101, which is more prone to deformation, can be pressed down. Optionally, the projection of the first sidewall 101 onto the first pressing plate 2 along its own width direction coincides with the centerline of the first pressing plate 2 along its own width direction.

[0053] like Figure 3 and Figure 4 As shown, optionally, the first pressing plate 2 includes a boss structure 21 and a pressing plate 22. The pressing plate 22 can contact and press against the first sidewall 101, and the boss structure 21 is disposed on the surface of the pressing plate 22 away from the first sidewall 101. The surface of the pressing plate 22 is larger, which can prevent the pressing area of ​​the aluminum-cased battery 100 to be inspected from being too concentrated. Optionally, the area of ​​the boss structure 21 is smaller than the area of ​​the pressing plate 22. The boss structure 21 on one side of the first pressing plate 2 is used to connect to the first fixing block 9, and the boss structure 21 on the other side of the first pressing plate 2 is used to connect to the output end of the first driving member 4. The boss structure 21 can support the pressing plate 22.

[0054] Optionally, the protrusion height of the boss structure 21 is e, where 0.3mm ≤ e ≤ 0.7mm. If the protrusion height e of the boss structure 21 is less than 0.3mm, the thickness of the boss structure 21 itself is insufficient. Under the drive of the first driving member 4, the boss structure 21 is subjected to excessive force and is prone to deformation, resulting in uneven force on the pressing plate 22. If the protrusion height e of the boss structure 21 is greater than 0.7mm, the boss structure 21 is too thick while ensuring structural strength, which is not conducive to cost control and space saving. Preferably, the protrusion height e of the boss structure 21 is 0.5mm.

[0055] like Figure 2As shown, optionally, the helium detection device also includes a helium detection vacuum unit 8, which is used for evacuating, filling with helium, and performing helium detection. The helium detection vacuum unit 8 includes a vacuum evacuation device (not shown in the figure) and a helium filling device (not shown in the figure).

[0056] Optionally, the cavity 1 has a first passage 111 and a second passage 112. One end of the first passage 111 and the second passage 112 are combined and connected to the evacuation port of the aluminum-cased battery 100 under test. Optionally, the evacuation port is the liquid injection port 103 of the aluminum-cased battery 100 under test. Optionally, a connector tube protrudes from the end of the combined passage. The connector tube can be inserted into the liquid injection port 103 to ensure the sealing at this point. The other end of the first passage 111 is connected to a vacuum pump, and the other end of the second passage 112 is connected to a helium filling device.

[0057] Optionally, the other end of the first passage 111 is connected to a vacuum pumping device via a first connecting pipe, and a solenoid valve 86 and a first vacuum pressure gauge 84 are installed on the first connecting pipe. Optionally, the other end of the second passage 112 is connected to a helium filling device via a second connecting pipe, and a solenoid valve 86 and a helium pressure gauge 83 are installed on the second connecting pipe.

[0058] Optionally, a third passage 113 is also provided on the cavity 1, one end of the third passage 113 is connected to a vacuum pumping device, and the other end is connected to the inner cavity of the cavity 1.

[0059] Optionally, the helium detection vacuum unit 8 also includes a detection tube 81 and a helium detector 82. The detection tube 81 is used to connect the third passage 113 and the vacuum pumping equipment, and the gas inlet of the helium detector 82 is connected to the detection tube 81.

[0060] Optionally, the detection tube 81 is also equipped with a solenoid valve 86 and a second vacuum pressure gauge 85. The solenoid valve 86 is used to control the opening and closing of the pipeline.

[0061] Optionally, to facilitate the handling of the aluminum-cased battery 100 to be inspected, the cavity 1 includes an upper cavity 11 and a lower cavity 12, which are sealed together to form a sealed inner cavity. The first passage 111, the second passage 112, and the third passage 113 are all opened in the upper cavity 11, and the first assembly through hole, the second assembly through hole, the third assembly through hole, and the fourth assembly through hole are all opened on the lower cavity 12.

[0062] The helium gas is injected into the inner cavity of the aluminum-cased battery 100 under test via the following pathways: helium gas is output from a helium filling device, passes through a helium pressure gauge 83 and a solenoid valve 86 into the second passage 112, and then enters the aluminum-cased battery 100 under test through a connector tube. Optionally, the helium gas entering the aluminum-cased battery 100 under test can maintain a pressure selectable from 0 kPa to 800 kPa.

[0063] The vacuuming process for the internal cavity of the aluminum-cased battery 100 under test includes: gas inside the aluminum-cased battery 100 enters the first flow pipe through the injection hole 103, the connector pipe, and the first passage 111, then passes through the solenoid valve 86 and the first vacuum pressure gauge 84 to the vacuuming equipment. Optionally, the conventional range of vacuum pressure is -80 kPa to -101 kPa.

[0064] The vacuuming process for the inner cavity of chamber 1 includes: the gas in the inner cavity of chamber 1 enters the detection tube 81 through the third passage 113, passes through the solenoid valve 86 and the second vacuum pressure gauge 85, and then reaches the vacuuming equipment. The helium detection process is that the gas in the inner cavity of chamber 1 enters the detection tube 81 through the third passage 113, passes through the solenoid valve 86 and the second vacuum pressure gauge 85, and then reaches the helium detector 82.

[0065] Using this helium detection device, the battery manufacturing process includes the following steps: After the battery casing and cover plate are welded together, the welded, unfilled casing, serving as the aluminum-cased battery 100 to be inspected, is placed into the lower cavity 121, ensuring that the aluminum-cased battery 100 is in contact with the immovable first and second pressure plates 2 and 3 for positioning. Then, the first driving component 4 is activated to move the movable first pressure plate 2 to press against the first side wall 101, and the second driving component 5 moves the movable second pressure plate 3 to press against the second side wall 102. After pressurizing and constraining the four side walls of the aluminum-cased battery 100, the inner cavity of the aluminum-cased battery 100 is evacuated. The vacuum pressure is maintained for a period of time to check whether the aluminum-cased battery 100 has a large leakage problem. For the aluminum-cased battery 100 under test that does not have a major leakage problem, the inner cavity of chamber 1 is evacuated again, and then helium is filled into the aluminum-cased battery 100 under test, maintaining a positive pressure state of helium, and the helium concentration in the inner cavity of chamber 1 is detected. When the helium pressure is greater than 10 kPa, it can effectively detect whether there are defects such as peripheral weld spatter, dents, and pinholes in the aluminum-cased battery 100 under test, ensuring the quality and safety of the cell casing.

[0066] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make other variations or modifications based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A helium detection device, characterized in that, include: A cavity (1) is used to house an aluminum-cased battery (100) to be tested. The aluminum-cased battery (100) to be tested has two first sidewalls (101) and two second sidewalls (102) arranged opposite to each other. The area of ​​the first sidewalls (101) is larger than the area of ​​the second sidewalls (102). An anti-deformation unit is disposed on the side wall of the cavity (1), and the anti-deformation unit is capable of pressing against the two first side walls (101) and / or the two second side walls (102) respectively.

2. The helium detection device according to claim 1, characterized in that, The anti-deformation unit includes a first driving member (4) and two first pressing plates (2). The two first pressing plates (2) can press against the two first side walls (101) respectively. One first pressing plate (2) is connected to the output end of the first driving member (4). The first driving member (4) can drive the first pressing plate (2) to move closer to or away from the other first pressing plate (2). And / or, the anti-deformation unit includes a second driving member (5) and two second pressing plates (3), the two second pressing plates (3) can press against the two second side walls (102) respectively, one of the second pressing plates (3) is connected to the output end of the second driving member (5), and the second driving member (5) can drive the second pressing plate (3) to move closer to or away from the other second pressing plate (3).

3. The helium detection device according to claim 2, characterized in that, The anti-deformation unit also includes a first connecting rod (6), which is movably inserted through a first assembly through hole on the side wall of the cavity (1), and the first connecting rod (6) is sealed to the first assembly through hole; one end of the first connecting rod (6) is connected to the output end of the first driving member (4), and the other end is connected to a first pressure plate (2).

4. The helium detection device according to claim 2, characterized in that, The anti-deformation unit also includes a second connecting rod (7), which is movably inserted through a second assembly through hole on the side wall of the cavity (1), and the second connecting rod (7) is sealed to the second assembly through hole; one end of the second connecting rod (7) is connected to the output end of the second driving member (5), and the other end is connected to a second pressure plate (3).

5. The helium detection device according to claim 2, characterized in that, The two first sidewalls (101) are arranged opposite each other along the first direction. Along the first direction, the width of the second sidewall (102) is a, and the width of the second pressing plate (3) is b, satisfying a > b. And / or, the two second sidewalls (102) are arranged opposite each other along the second direction, along the second direction, the width of the first sidewall (101) is c, and the width of the first pressure plate (2) is d, satisfying d>c.

6. The helium detection device according to any one of claims 1-5, characterized in that, It also includes a pressure sensor, which is disposed on the anti-deformation unit and is used to measure the pressure exerted by the anti-deformation unit on the first sidewall (101) and / or on the second sidewall (102).

7. The helium detection device according to any one of claims 2-5, characterized in that, The first pressing plate (2) includes a boss structure (21) and a pressing plate (22). The pressing plate (22) can contact and press against the first side wall (101). The boss structure (21) is disposed on the surface of the pressing plate (22) away from the first side wall (101).

8. The helium detection device according to claim 7, characterized in that, The area of ​​the boss structure (21) is smaller than the area of ​​the pressure plate (22), and the height of the boss structure (21) protruding from the pressure plate (22) is e, 0.3mm≤e≤0.7mm.

9. The helium detection device according to any one of claims 1-5, characterized in that, The helium detection device also includes a helium detection vacuum unit (8), which includes a vacuum pumping device and a helium filling device. The cavity (1) is provided with a first passage (111) and a second passage (112). One end of the first passage (111) and the second passage (112) are connected to the air extraction port of the aluminum shell battery (100) to be tested. The other end of the first passage (111) is connected to the vacuum pumping device, and the other end of the second passage (112) is connected to the helium filling device. And / or, a third passage (113) is also provided on the cavity (1), one end of the third passage (113) is connected to the vacuum pumping device, and the other end is connected to the inner cavity of the cavity (1).

10. The helium detection device according to claim 9, characterized in that, The helium detection vacuum unit (8) further includes a detection tube (81) and a helium detector (82). The detection tube (81) is used to connect the third passage (113) and the vacuum pumping device. The gas inlet of the helium detector (82) is connected to the detection tube (81).

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