Battery airtightness detection device and method

Abstract

The present application provides a battery airtightness detection device and method, belonging to the technical field of battery manufacturing. The battery airtightness detection device includes a detection box, an air extraction component, and a first detection component. The detection box has a containing cavity for placing a battery to be tested; the air extraction component is connected to the detection box and is used to extract the gas in the containing cavity; the first detection component is connected to the detection box and is used to detect the content of volatile organic compounds in the gas in the containing cavity before performing airtightness detection on the battery to be tested.

Description

Technical Field

[0001] This application relates to the technical field of battery manufacturing, and particularly relates to a battery airtightness detection device and method. Background Art

[0002] Energy conservation and emission reduction are the keys to the sustainable development of the automotive industry. Electric vehicles have become an important part of the sustainable development of the automotive industry due to their energy-saving and environmental protection advantages. For electric vehicles, battery technology is an important factor related to their development.

[0003] During the use of a battery, the airtightness of the battery has a great impact on the battery life. Therefore, there is an urgent need for a battery airtightness detection device to detect the airtightness of the battery. Summary of the Invention

[0004] This application aims to solve at least one of the technical problems existing in the background art. For this reason, one object of this application is to provide a battery airtightness detection device and method to improve the accuracy of battery airtightness detection.

[0005] An embodiment of the first aspect of this application provides a battery airtightness detection device, including a detection box, an air extraction component, and a first detection component. The detection box has a receiving cavity for placing a battery to be tested; the air extraction component is connected to the detection box and is used to extract the gas in the receiving cavity; the first detection component is connected to the detection box and is used to detect the content of volatile organic compounds in the gas in the receiving cavity before detecting the airtightness of the battery to be tested.

[0006] In the technical solution of the embodiment of this application, by placing the battery to be tested in the receiving cavity of the detection box, using the air extraction component to extract the gas in the receiving cavity, and using the first detection component connected to the detection box to detect the content of volatile organic compounds in the gas in the receiving cavity before detecting the airtightness of the battery to be tested, the content of volatile organic compounds in the gas in the receiving cavity can be effectively detected, so as to determine whether there is electrolyte crystallization blocking the pores in the battery to be tested, thereby reducing the misjudgment rate of airtightness detection caused by electrolyte crystallization blocking the pores during battery airtightness detection and improving the accuracy of battery airtightness detection.

[0007] In some embodiments, the battery airtightness detection device further includes a gas transmission component and a second detection component. The gas transmission component is connected to the detection box and is used to transport a specific gas into the receiving cavity; the second detection component is connected to the detection box and is used to perform mass spectrometry detection on the gas in the receiving cavity. The gas transmission component is used to transport a specific gas into the receiving cavity, and the second detection component is used to perform mass spectrometry detection on the gas in the receiving cavity. Mass spectrometry detection can detect micron-sized leakage holes, so that the airtightness detection device can safely and efficiently detect the sealing performance of the battery to be tested, thereby improving the detection accuracy of the battery airtightness detection device.

[0008] In some embodiments, the battery airtightness detection device further includes a shielding member, which is located in the accommodation cavity and is floatingly arranged above the battery to be tested, and the shielding member is used to shield the top surface of the battery to be tested. By shielding the top surface of the battery to be tested with the shielding member, it is possible to prevent the air extraction component from extracting the gas inside the battery to be tested during the process of extracting the gas in the accommodation cavity, thereby improving the accuracy of the detection result of the battery airtightness detection device.

[0009] In some embodiments, the side of the shielding member facing the top surface of the battery to be tested matches the shape of the top surface of the battery to be tested, so that the shielding member is in sealed contact with the top surface of the battery to be tested. The side of the shielding member facing the top surface of the battery to be tested matches the shape of the top surface of the battery to be tested, so that the shielding member is in sealed contact with the top surface of the battery to be tested, which can completely shield the top surface of the battery to be tested when the battery airtightness detection device is in the gas detection operation, further reducing the probability of extracting the specific gas inside the battery to be tested, thereby further improving the accuracy of the detection result of the battery airtightness detection device.

[0010] In some embodiments, the battery airtightness detection device further includes a driving component, which is connected to the shielding member and at least partially extends out of the detection box to drive the shielding member to approach or move away from the top surface of the battery to be tested. By driving the shielding member to approach or move away from the top surface of the battery to be tested through the driving component, the operation is simple and reliable.

[0011] In some embodiments, the battery airtightness detection device further includes a gas pipeline, which includes a main pipeline communicating with the accommodation cavity and a plurality of branch pipelines communicating with the main pipeline, and each branch pipeline is respectively communicated with different components. The detection box can realize the separate communication between the accommodation cavity and the air extraction component, the first detection component, the gas transmission component and the second detection component only through one pipeline. This structure only needs to set one ventilation hole on the detection box for communicating with the gas pipeline, without additionally setting a plurality of ventilation holes, thereby indirectly enhancing the structural reliability of the detection box and reducing the risk of gas in the external environment entering the accommodation cavity through the gas pipeline.

[0012] In some embodiments, valves are respectively arranged on each branch pipeline. By respectively arranging valves on each branch pipeline, it is possible to flexibly control the communication between each component and the accommodation cavity when the battery airtightness detection device is in different working states.

[0013] In some embodiments, the battery airtightness detection device further includes a pressure detection member, which is arranged on the main pipeline and is used to detect the pressure in the accommodation cavity. By arranging a pressure detection member on the main pipeline to detect the pressure in the accommodation cavity, the structure of the battery gas detection device can be simplified, and the detection process of the pressure in the accommodation cavity can be simplified.

[0014] In some embodiments, there are multiple batteries to be tested. Multiple batteries to be tested can be placed in the accommodating cavity at the same time to improve the detection efficiency of the battery air tightness detection device.

[0015] An embodiment of the second aspect of the present application provides a battery air tightness detection method, which includes: placing a battery to be tested in a receiving chamber of a detection box; extracting the gas in the receiving chamber; and before performing an air tightness test on the battery to be tested, detecting the content of volatile organic compounds in the gas in the receiving chamber.

[0016] In the technical solution of the embodiment of the present application, by placing the battery to be tested in a containing cavity and extracting the gas in the containing cavity, the content of volatile organic compounds in the gas in the containing cavity is detected before the air tightness test of the battery to be tested is performed. The content of volatile organic compounds in the gas in the containing cavity can be effectively detected, thereby determining whether there is electrolyte crystallization blocking the pores in the battery to be tested, thereby reducing the misjudgment rate of the air tightness test caused by electrolyte crystallization blocking the pores during the battery air tightness test, and improving the accuracy of the battery air tightness test.

[0017] In some embodiments, the battery airtightness testing method further includes: delivering a specific gas into the receiving chamber in response to the volatile organic compound content being less than a preset threshold; exhausting the specific gas from the receiving chamber; and performing mass spectrometry on the gas within the receiving chamber. Delivering the specific gas into the receiving chamber and performing mass spectrometry on the gas within the receiving chamber can detect micron-scale leaks. Thus, the battery airtightness testing method can safely and efficiently test the sealing performance of the battery under test, thereby improving the accuracy of battery airtightness testing.

[0018] In some embodiments, discharging the specific gas from the receiving chamber includes: extracting the gas from the receiving chamber; injecting nitrogen or compressed air into the receiving chamber; and further extracting the gas from the receiving chamber. By extracting the gas from the receiving chamber, injecting nitrogen or compressed air into the receiving chamber, and further extracting the gas from the receiving chamber, the specific gas remaining or adhering to the chamber can be better removed, thereby further improving the accuracy of the battery air tightness test.

[0019] In some embodiments, delivering the specific gas into the receiving chamber includes delivering the specific gas into the receiving chamber and maintaining the pressure in the receiving chamber for a preset time period. By delivering the specific gas into the receiving chamber and maintaining the pressure in the receiving chamber for a preset time period, the specific gas can enter the battery under test, thereby improving the accuracy of the battery airtightness test.

[0020] In some embodiments, the battery airtightness detection method further includes: sealing the top surface of the battery under test when discharging the specific gas in the accommodation cavity. By sealing the top surface of the battery under test when discharging the specific gas in the accommodation cavity, the probability of the specific gas in the battery being discharged can be reduced when discharging the specific gas in the accommodation cavity, thereby improving the accuracy of the detection result of the battery airtightness detection device.

[0021] The above description is only an overview of the technical solution of the present application. In order to be able to understand the technical means of the present application more clearly, it can be implemented in accordance with the content of the specification. And in order to make the above and other purposes, features and advantages of the present application more obvious and understandable, the following specifically illustrates the specific embodiments of the present application. Brief Description of the Drawings

[0022] In the drawings, unless otherwise specified, the same reference numerals throughout the several views denote the same or similar components or elements. These drawings are not necessarily drawn to scale. It should be understood that these drawings only depict some embodiments disclosed in accordance with the present application and should not be regarded as limiting the scope of the present application.

[0023] Figure 1 It is a schematic diagram of a battery airtightness detection device according to some embodiments of the present application;

[0024] Figure 2 It is a schematic diagram of a battery under test according to some embodiments of the present application;

[0025] Figure 3 It is a schematic diagram of a driving component according to some embodiments of the present application;

[0026] Figure 4 It is a schematic diagram of a battery airtightness detection device according to some embodiments of the present application;

[0027] Figure 5 It is the flow chart of the battery airtightness detection method according to some embodiments of the present application Figure 1 ;

[0028] Figure 6 It is the flow chart of the battery airtightness detection method according to some embodiments of the present application Figure 2 。

[0029] Description of the Reference Numerals:

[0030] 100, battery airtightness detection device;

[0031] 10, detection box; 11, air extraction component; 12, first detection component; 13, gas transmission component; 14, second detection component; 15, shielding member; 16, driving component; 17, main pipeline; 18, branch pipeline; 19, valve; 30, pressure detection member;

[0032] 20. Battery under test; 21. End cap; 22. Housing; 23. Electrode terminal; 24. Explosion-proof valve; 25. Sealing nail. Detailed implementation manners

[0033] The embodiments of the technical solution of the present application will be described in detail below with reference to the accompanying drawings. The following embodiments are only used to illustrate the technical solution of the present application more clearly, so they are only examples and cannot be used to limit the protection scope of the present application.

[0034] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those skilled in the technical field to which this application belongs; the terms used herein are only for the purpose of describing specific embodiments and are not intended to limit this application; the terms "including" and "having" and any variations thereof in the specification and claims of this application and the above accompanying drawings are intended to cover non-exclusive inclusion.

[0035] In the description of the embodiments of this application, technical terms such as "first" and "second" are only used to distinguish different objects and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity, specific order or primary-secondary relationship of the indicated technical features. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise specifically and clearly defined.

[0036] Referring to "embodiments" herein means that the specific features, structures or characteristics described in connection with the embodiments can be included in at least one embodiment of this application. The phrase appears in various places in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment mutually exclusive with other embodiments. Those skilled in the art explicitly and implicitly understand that the embodiments described herein can be combined with other embodiments.

[0037] In the description of the embodiments of this application, the term "and / or" is only a description of the association relationship of associated objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist simultaneously, and B exists alone. In addition, the character " / " in this article generally represents an "or" relationship between the associated objects before and after.

[0038] In the description of the embodiments of this application, the term "a plurality of" refers to two or more (including two). Similarly, "multiple groups" refers to two or more groups (including two groups), and "multiple pieces" refers to two or more pieces (including two pieces).

[0039] In the description of the embodiments of the present application, the orientation or positional relationship indicated by technical terms such as "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. is based on the orientation or positional relationship shown in the drawings. It is only for the convenience of describing the embodiments of the present application and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, it should not be construed as a limitation on the embodiments of the present application.

[0040] In the description of the embodiments of the present application, unless otherwise clearly specified and limited, technical terms such as "installation", "connection", "connection", "fixation", etc. should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or integrated; it can also be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements or the interaction relationship between two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the embodiments of the present application can be understood according to specific situations.

[0041] Currently, from the perspective of the development of the market situation, the application of power batteries is becoming more and more extensive. Power batteries are not only used in energy storage power systems such as hydropower, thermal power, wind power, and solar power stations, but also widely used in electric transportation such as electric bicycles, electric motorcycles, and electric vehicles, as well as in multiple fields such as military equipment and aerospace. With the continuous expansion of the application fields of power batteries, the market demand is also constantly increasing.

[0042] In the related art, after the electrolyte is injected into the battery, the injection hole is sealed by welding a sealing nail to achieve battery sealing. Air tightness detection is an essential part of battery detection. Specifically, methods such as leak detection are required to determine whether the injection hole of the battery is completely closed. For battery air tightness detection, the helium detection method is commonly used. The helium detection method is to inject helium into the battery and determine whether there is a leak point in the battery by detecting whether the helium leaks from the battery.

[0043] Generally, there are two helium detection methods. Method 1: After injecting the electrolyte into the battery, helium is pressed in, the injection hole is sealed with a sealing nail, and after the sealing nail is welded, the air tightness of the battery is confirmed by helium detection. Method 2: After the sealing nail is welded, helium is pressed into the position of the battery sealing nail to detect the air tightness of the sealing nail area. The above methods all have the problem that when the electrolyte crystallizes and blocks the hole, the air tightness detection will fail.

[0044] Based on this, an embodiment of the present application proposes a battery airtightness detection device. By placing the battery to be tested in the accommodation cavity of the detection box and using an air extraction component to extract the gas in the accommodation cavity, a first detection component connected to the detection box is used to detect the content of volatile organic compounds in the gas in the accommodation cavity before detecting the airtightness of the battery to be tested. The content of volatile organic compounds in the gas in the accommodation cavity can be effectively detected, so as to determine whether there is electrolyte crystallization and blockage of holes in the battery to be tested, thereby reducing the misjudgment rate of airtightness detection caused by electrolyte crystallization and blockage of holes during battery airtightness detection and improving the accuracy of battery airtightness detection.

[0045] The battery airtightness detection device disclosed in the embodiment of the present application can be but is not limited to being used for lithium batteries, sodium batteries, etc.

[0046] An embodiment of the present application provides a battery airtightness detection device 100. Figure 1 It is a schematic diagram of the battery airtightness detection device 100 provided by some embodiments of the present application. Figure 2 It is a schematic diagram of the battery 20 to be tested in some embodiments of the present application. Figure 3 It is a schematic diagram of the driving component 16 in some embodiments of the present application. Figure 4 It is a schematic diagram of the battery airtightness detection device 100 in some embodiments of the present application. As Figures 1 to 4 shown, the battery airtightness detection device 100 includes a detection box 10, an air extraction component 11, and a first detection component 12. The detection box 10 has an accommodation cavity for placing the battery 20 to be tested; the air extraction component 11 is connected to the detection box 10 and is used to extract the gas in the accommodation cavity; the first detection component 12 is connected to the detection box 10 and is used to detect the content of volatile organic compounds in the gas in the accommodation cavity before detecting the airtightness of the battery 20 to be tested.

[0047] In the example, as Figure 2As shown, the battery 20 to be tested may include an end cap 21, a housing 22, electrode terminals 23, an explosion-proof valve 24, and a sealing pin 25. The end cap 21 refers to a component that covers the opening of the housing 22 to isolate the internal environment of the battery 20 to be tested from the external environment. Without limitation, the shape of the end cap 21 may be adapted to the shape of the housing 22 to cooperate with the housing 22. In some embodiments, the end cap 21 may be made of a material with a certain hardness and strength (such as aluminum alloy). In this way, the end cap 21 is not easily deformed when subjected to extrusion and collision, enabling the battery 20 to be tested to have higher structural strength and improved safety performance. The electrode terminals 23 may be provided on the end cap 21. The electrode terminals 23 may be used to electrically connect to the cell assembly for outputting or inputting the electrical energy of the battery 20 to be tested. The explosion-proof valve 24 for releasing the internal pressure when the internal pressure or temperature of the battery 20 to be tested reaches a threshold may also be provided on the end cap 21. The sealing pin 25 may also be provided on the end cap 21, and the sealing pin 25 is used to seal the liquid injection port after the electrolyte injection is completed.

[0048] The housing 22 is a component used to cooperate with the end cap 21 to form the internal environment of the battery 20 to be tested. Among them, the formed internal environment may be used to accommodate the cell assembly, the electrolyte, and other components. The housing 22 and the end cap 21 may be independent components. An opening may be provided on the housing 22, and the end cap 21 is covered on the opening to form the internal environment of the battery 20 to be tested. Without limitation, the end cap 21 and the housing 22 may also be integrated. Specifically, the end cap 21 and the housing 22 may first form a common connection surface before other components are put into the housing. When it is necessary to encapsulate the inside of the housing 22, the end cap 21 is then covered on the housing 22. The housing 22 may have various shapes and sizes, such as rectangular, cylindrical, hexagonal prism-shaped, etc. Specifically, the shape of the housing 22 may be determined according to the specific shape and size of the cell assembly. The material of the housing 22 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc.

[0049] In the example, the detection box 10 has a hollow structure and is in separable contact with the battery 20 to be tested. The detection box 10 has an accommodation cavity inside. Placing the battery 20 to be tested in the accommodation cavity can isolate the battery 20 to be tested from the external environment. The external shape structure of the detection box 10 may be determined according to the size and shape of the battery 20 to be tested, and may be square, arc-shaped, or other irregular shapes, etc.

[0050] Since the electrolyte contains moisture, and some electrolytes in the electrolyte are prone to crystallization when exposed to air, especially at lower ambient temperatures. Therefore, electrolyte crystallization is likely to occur during the battery filling process, and the electrolyte crystallization will block the filling hole of the battery, resulting in the failure of the battery airtightness detection. In order to detect the battery airtightness, it is possible to first detect whether there is electrolyte crystallization blocking the hole in the battery. Since electrolyte crystallization will produce volatile organic compounds (VOCs), the air can contain volatile organic compounds. Thus, by detecting the content of volatile organic compounds in the gas in the cavity accommodating the battery under test 20, it is possible to detect whether there is electrolyte crystallization in the battery under test 20.

[0051] In the example, the air extraction component 11 can be connected to the detection box 10 through pipelines or other means, and is used to extract the gas initially present in the cavity, that is, to discharge the gas in the cavity, so that the cavity forms a vacuum state.

[0052] In the example, the first detection component 12 is connected to the detection box 10 through pipelines or other means, and is used to detect the content of volatile organic compounds in the gas in the cavity before performing the airtightness detection on the battery under test 20. Specifically, when the battery airtightness detection device 100 is working, the air extraction component 11 is used to pre-vacuum the cavity. After the vacuum treatment is completed, the battery under test 20 and the battery airtightness detection device 100 are placed statically. After a certain period of static time, the first detection component 12 works. If there is no electrolyte crystallization blocking the hole in the battery under test 20, the content of volatile organic compounds in the gas in the cavity is extremely low, less than the preset threshold; if the battery under test 20 has electrolyte crystallization blocking the hole, volatile organic compounds will be generated, and at this time, the first detection component 12 can detect that the content of volatile organic compounds detected in the cavity is greater than the preset threshold. Therefore, the first detection component 12 can determine whether there is electrolyte crystallization blocking the hole in the battery under test 20 by detecting the content of volatile organic compounds in the gas in the cavity.

[0053] In the example, the first detection component 12 can be any instrument that can detect volatile organic compounds, such as a photoionization detector (PID), a volatile organic compound detector, etc. Exemplarily, detecting the content of volatile organic compounds can be detecting the content of any one or more volatile organic compounds such as dimethyl carbonate, ethylene carbonate, and ethyl methyl carbonate. If the detection value is greater than or equal to 0.5 parts per million, it can be considered that the battery has electrolyte crystallization.

[0054] In the embodiments of the present application, by placing the battery 20 to be tested in the accommodation cavity of the detection box 10, and using the air extraction assembly 11 to extract the gas in the accommodation cavity, and using the first detection assembly 12 connected to the detection box 10 to detect the content of volatile organic compounds in the gas in the accommodation cavity before performing the airtightness detection on the battery 20 to be tested, the content of volatile organic compounds in the gas in the accommodation cavity can be effectively detected, so as to determine whether there is electrolyte crystallization and blockage of holes in the battery 20 to be tested, thereby reducing the misjudgment rate of the airtightness detection caused by electrolyte crystallization and blockage of holes during the battery airtightness detection, and improving the accuracy of the battery airtightness detection.

[0055] According to some embodiments of the present application, as Figure 1 shown, the battery airtightness detection device 100 further includes a gas transmission assembly 13 and a second detection assembly 14. The gas transmission assembly 13 is connected to the detection box 10 and is used to transport a specific gas into the accommodation cavity; the second detection assembly 14 is connected to the detection box 10 and is used to perform mass spectrometry detection on the gas in the accommodation cavity.

[0056] In the example, after detecting the content of volatile organic compounds in the gas in the accommodation cavity and determining that the content of volatile organic compounds in the gas in the accommodation cavity is less than a preset threshold, that is, when it is determined that there is no electrolyte crystallization and blockage of holes in the battery 20 to be tested, the airtightness detection of the battery 20 to be tested can be further performed.

[0057] In the example, the gas transmission assembly 13 may include a plurality of gas transmission members, and the plurality of gas transmission members may be respectively used to transport different specific gases into the accommodation cavity. For example, one gas transmission member may be used to transport a tracer gas into the accommodation cavity, where the tracer gas may be one of helium, hydrogen, neon, argon, helium-nitrogen mixture, hydrogen-nitrogen mixture, etc.; another gas transmission member may be used to transport nitrogen or compressed air into the accommodation cavity.

[0058] In the example, the second detection assembly 14 may be a mass spectrometer. The second detection assembly 14 is used to perform mass spectrometry detection on the gas in the accommodation cavity, and it can be determined whether the battery 20 to be tested leaks according to whether the tracer is detected. Exemplarily, during mass spectrometry detection, when the detection value is greater than or equal to 1E-7 Pascal times cubic meter per second (Pa m 3 / s), it can be considered that the battery has a leak. Different tracer gases can conform to the following formula during mass spectrometry detection:

[0059]

[0060] where R is the magnetic deflection radius, U is the acceleration voltage, B is the magnetic induction intensity, and m / q is the mass-to-charge ratio of the tracer gas. According to the above formula, different tracer gases can be detected by adjusting the acceleration voltage.

[0061] In the embodiment of the present application, the battery airtightness detection device 100 can detect the airtightness of the end cap 21 solder joints, explosion-proof valves 24, sealing nails 25, electrode terminals 23, etc. of the battery under test 20.

[0062] In the embodiment of the present application, the gas transmission component 13 is used to transport a specific gas into the accommodation cavity, and the second detection component 14 is used to perform mass spectrometry detection on the gas in the accommodation cavity. Mass spectrometry detection can detect micron-sized leakage holes, so that the battery airtightness detection device 100 can safely and efficiently detect the airtightness of the battery under test 20 to improve the detection accuracy of the battery airtightness detection device 100.

[0063] According to some embodiments of the present application, the battery airtightness detection device 100 further includes a shielding member 15. The shielding member 15 is located in the accommodation cavity and is floatingly arranged above the battery under test 20. The shielding member 15 is used to shield the top surface of the battery under test 20.

[0064] In the example, when the air extraction component 11 performs a vacuum pumping process on the accommodation cavity, by controlling the shielding member 15 to shield the top surface of the battery under test 20, the top surface of the battery under test 20 is isolated from the gas environment in the accommodation cavity, thereby forming a protective effect and preventing the subsequent detection accuracy of the second detection component 14 from being affected. Specifically, if the top surface of the battery under test 20 is in a leaky state, while the air extraction component 11 extracts the gas in the accommodation cavity, it will also extract the specific gas in the battery under test 20. When the second detection component 14 works later, even if the battery under test 20 leaks, the second detection component 14 cannot detect the specific gas, and it is easy to obtain an incorrect detection result. The setting of the shielding member 15 isolates the battery under test 20 from the gas environment in the accommodation cavity, so that the second air extraction component 11 can only extract the gas in the accommodation cavity and cannot extract the gas in the battery under test 20, thereby improving the final detection accuracy.

[0065] In the embodiment of the present application, by shielding the top surface of the battery under test 20 with the shielding member 15, it is possible to prevent the air extraction component 11 from extracting the gas inside the battery under test 20 during the process of extracting the gas in the accommodation cavity, thereby improving the accuracy of the detection result of the battery airtightness detection device 100.

[0066] According to some embodiments of the present application, the side of the shielding member 15 facing the top surface of the battery under test 20 matches the shape of the top surface of the battery under test 20, so that the shielding member 15 is in sealing contact with the top surface of the battery under test 20.

[0067] In the example, such as Figure 1 and Figure 3As shown, the side of the shielding member 15 facing the top surface of the battery to be tested 20 matches the shape of the top surface of the battery to be tested 20. During the process of the gas transmission component 13 delivering a specific gas into the accommodating chamber and during the vacuuming process, the shielding member 15 is in sealing contact with the top surface of the battery to be tested 20, that is, the shielding member 15 can completely cover the top surface of the battery to be tested 20.

[0068] In the embodiment of the present application, the side of the shielding member 15 facing the top surface of the battery to be tested 20 matches the shape of the top surface of the battery to be tested 20, so that the shielding member 15 is in sealing contact with the top surface of the battery to be tested 20, and can completely block the top surface of the battery to be tested 20 when the battery air tightness testing device 100 is in gas detection operation, further reducing the probability of extracting specific gases inside the battery to be tested 20, thereby further improving the accuracy of the detection results of the battery air tightness testing device 100.

[0069] According to some embodiments of the present application, the battery air tightness testing device 100 further includes a driving assembly 16 , which is connected to the shielding member 15 and at least partially extends out of the testing box 10 to drive the shielding member 15 toward or away from the top surface of the battery 20 to be tested.

[0070] In the example, Figure 3 As shown, the drive assembly 16 is located on a side of the shielding member 15 facing away from the battery 20 under test and is directly connected to the shielding member 15, and is used to drive the shielding member 15 toward or away from the top surface of the battery 20 under test. At least a portion of the drive assembly 16 extends out of the test box 10, and the shielding member 15 is connected to the exterior of the test box 10 via the drive assembly 16. The drive assembly 16 is capable of sliding relative to the test box 10, thereby driving the shielding member 15 to rise or fall. The drive assembly 16 can control the movement of the shielding member 15 manually or automatically.

[0071] In the embodiment of the present application, the shielding member 15 is driven to move closer to or away from the top surface of the battery to be tested 20 by the driving assembly 16 , and the operation is simple and reliable.

[0072] According to some embodiments of the present application, Figure 1 and Figure 4 As shown, the battery air tightness detection device 100 further includes a gas pipeline, which includes a main pipeline 17 connected to the accommodating cavity, and multiple branch pipelines 18 connected to the main pipeline 17, and each branch pipeline 18 is connected to a different component.

[0073] In the example, the air extraction assembly 11, the first detection assembly 12, the gas transmission assembly 13, and the second detection assembly 14 are all connected to the accommodation cavity through gas pipelines. Among them, the gas pipelines include a main pipeline 17 connected to the accommodation cavity, and a plurality of branch pipelines 18 connected to the main pipeline 17. Each branch pipeline 18 is respectively connected to the air extraction assembly 11, the first detection assembly 12, the gas transmission assembly 13, and the second detection assembly 14.

[0074] In the example, when the battery airtightness detection device 100 is in the vacuum pumping operation, the air extraction assembly 11 works, and the gas in the accommodation cavity enters the branch pipeline 18 connected to the air extraction assembly 11 through the main pipeline 17 and is finally sucked away by the air extraction assembly 11.

[0075] In the example, when the battery airtightness detection device 100 is in the operation of detecting the content of volatile organic compounds, the gas in the accommodation cavity enters the branch pipeline 18 connected to the air extraction assembly 11 through the main pipeline 17, is finally sucked away by the air extraction assembly 11, enters the first detection assembly 12, and is finally detected by the first detection assembly 12.

[0076] In the example, when the battery airtightness detection device 100 is in the mass spectrometry detection operation, the second detection assembly 14 works. If the battery under test 20 leaks air, the specific gas leaks from the battery under test 20 to the accommodation cavity, enters the branch pipeline 18 connected to the second detection assembly 14 through the main pipeline, and is finally detected by the second detection assembly 14.

[0077] In the embodiment of the present application, the detection box 10 can realize the separate connection between the accommodation cavity and the air extraction assembly 11, the first detection assembly 12, the gas transmission assembly 13, and the second detection assembly 14 only through one pipeline. This structure only needs to set one ventilation hole on the detection box 10 for connecting with the gas pipeline, without additionally setting a plurality of ventilation holes, thereby indirectly enhancing the structural reliability of the detection box 10 and reducing the risk of gas in the external environment entering the accommodation cavity through the gas pipeline.

[0078] According to some embodiments of the present application, valves 19 are respectively provided on each branch pipeline 18.

[0079] In the example, the valve 19 is used to control the communication between the air extraction assembly 11, the first detection assembly 12, the gas transmission assembly 13, and the second detection assembly 14 and the accommodation cavity respectively. Specifically, when extracting the gas in the accommodation cavity, the valve 19 on the branch pipeline 18 connected to the air extraction assembly 11 is opened. When detecting the content of volatile organic compounds in the gas in the accommodation cavity, the valve 19 on the branch pipeline 18 connected to the first detection assembly 12 is opened. When delivering a specific gas into the accommodation cavity, the valve 19 on the branch pipeline 18 connected to the gas transmission assembly 13 is opened. When performing mass spectrometry detection on the gas in the accommodation cavity, the valve 19 on the branch pipeline 18 connected to the second detection assembly 14 is opened.

[0080] In the embodiment of the present application, by respectively providing valves 19 on each branch pipeline 18, flexible control of the communication between each component and the accommodation cavity can be achieved when the battery airtightness detection device 100 is in different working states.

[0081] According to some embodiments of the present application, the battery airtightness detection device 100 further includes a pressure detection member 30, and the pressure detection member 30 is arranged on the main pipeline 17 for detecting the pressure in the accommodation cavity.

[0082] In the example, the pressure detection component can be any one of devices such as a liquid barometer, an aneroid barometer, a barometer, a diaphragm box type capacitive pressure sensor, a vibrating cylinder type pressure sensor, etc. that can be used for air pressure detection. The pressure detection member 30 is arranged on the main pipeline 17. Since the main pipeline 17 is communicated with the accommodation cavity, the pressure of the gas in the main pipeline 17 is the same as the pressure of the gas in the accommodation cavity. By arranging the pressure detection member 30 on the main pipeline 17 to detect the pressure in the accommodation cavity.

[0083] In the embodiment of the present application, by arranging the pressure detection member 30 on the main pipeline 17 to detect the pressure in the accommodation cavity, the structure of the battery gas detection device can be simplified, and the detection process of the pressure in the accommodation cavity can be simplified.

[0084] According to some embodiments of the present application, the number of batteries 20 to be tested is multiple.

[0085] In the example, as Figure 4 shown, multiple batteries 20 to be tested can be arranged and placed in the accommodation cavity in a certain order, so that the battery airtightness detection device 100 can simultaneously detect the airtightness of multiple batteries 20 to be tested.

[0086] In the embodiment of the present application, multiple batteries 20 to be tested can be placed in the accommodation cavity simultaneously to improve the detection efficiency of the battery airtightness detection device 100.

[0087] The embodiment of the present application provides a method for detecting the airtightness of a battery. Figure 5Schematic flow chart of the battery airtightness detection method provided by the embodiments of the present application, as Figure 5 shown, the battery airtightness detection method includes: Step S510, placing the battery to be tested in the accommodation cavity of the detection box; Step S520, extracting the gas in the accommodation cavity; Step S530, before detecting the airtightness of the battery to be tested, detecting the content of volatile organic compounds in the gas in the accommodation cavity.

[0088] Since the electrolyte contains moisture, and some electrolytes in the electrolyte are easily crystallized when contacting air, especially in the case of lower ambient temperature, the crystallization phenomenon is particularly common. Therefore, electrolyte crystallization is likely to occur during the liquid injection process of the battery, and the electrolyte crystallization will block the liquid injection hole of the battery, resulting in the failure of the battery airtightness detection. In order to detect whether there is electrolyte crystallization and blockage of the hole in the battery for the battery airtightness detection. Since electrolyte crystallization will produce volatile organic compounds (VOCs), the air can contain volatile organic compounds. Thus, by detecting the content of volatile organic compounds in the gas in the accommodation cavity where the battery to be tested is placed, it is possible to detect whether there is electrolyte crystallization in the battery to be tested.

[0089] In the example, placing the battery to be tested in the accommodation cavity can isolate the battery to be tested from the external environment. Extracting the gas in the accommodation cavity can make the accommodation cavity in a vacuum state. After the vacuum treatment is completed, the battery to be tested is placed statically. After a certain period of static time, the content of volatile organic compounds in the gas in the accommodation cavity is detected. If there is no electrolyte crystallization and blockage of the hole in the battery to be tested, the content of volatile organic compounds in the gas in the accommodation cavity is extremely low, less than the preset threshold; when the battery to be tested has electrolyte crystallization and blockage of the hole, volatile organic compounds will be generated, and at this time, the detection component can detect that the content of volatile organic compounds detected in the accommodation cavity is greater than the preset threshold. Therefore, by detecting the content of volatile organic compounds in the gas in the accommodation cavity, it is possible to determine whether there is electrolyte crystallization and blockage of the hole in the battery to be tested.

[0090] In the embodiments of the present application, by placing the battery to be tested in the accommodation cavity, extracting the gas in the accommodation cavity, and detecting the content of volatile organic compounds in the gas in the accommodation cavity before detecting the airtightness of the battery to be tested, the content of volatile organic compounds in the gas in the accommodation cavity can be effectively detected, so as to determine whether there is electrolyte crystallization and blockage of the hole in the battery to be tested, thereby reducing the misjudgment rate of the airtightness detection caused by electrolyte crystallization and blockage of the hole during the battery airtightness detection, and improving the accuracy of the battery airtightness detection.

[0091] According to some embodiments of the present application, as Figure 5As shown, the battery airtightness detection method further includes: step S540, in response to the content of volatile organic compounds being less than a preset threshold, delivering a specific gas into the accommodation cavity; step S550, discharging the specific gas in the accommodation cavity; step S560, performing mass spectrometry detection on the gas in the accommodation cavity.

[0092] Step S540, in response to the content of volatile organic compounds being less than a preset threshold, delivering a specific gas into the accommodation cavity.

[0093] In the example, after detecting the content of volatile organic compounds in the gas in the accommodation cavity and determining that the content of volatile organic compounds in the gas in the accommodation cavity is less than the preset threshold, that is, when there is no electrolyte crystallization blocking the holes in the battery under test, the airtightness of the battery under test can be further detected.

[0094] In the example, the specific gas may include a tracer gas, and the tracer gas may be one of gases such as helium, hydrogen, neon, argon, helium-nitrogen mixture, hydrogen-nitrogen mixture, etc.

[0095] Step S550, discharging the specific gas in the accommodation cavity.

[0096] In the example, discharging the specific gas in the accommodation cavity may include pumping out the gas in the accommodation cavity. Discharging the specific gas in the accommodation cavity may also include pumping out the gas in the accommodation cavity, injecting nitrogen or compressed air into the accommodation cavity; and pumping out the gas in the accommodation cavity again.

[0097] Step S560, performing mass spectrometry detection on the gas in the accommodation cavity.

[0098] In the example, by performing mass spectrometry detection on the gas in the accommodation cavity, it can be determined whether the battery leaks according to whether the tracer is detected. Exemplarily, during mass spectrometry detection, when the detection value is greater than or equal to 1E-7 Pa m 3 / s, it can be considered that the battery has a leak. Different tracer gases can conform to the following formula during mass spectrometry detection:

[0099]

[0100] In the formula, R is the magnetic deflection radius, U is the acceleration voltage, B is the magnetic induction intensity, and m / q is the mass-to-charge ratio of the tracer gas. According to the above formula, different tracer gases can be detected by adjusting the acceleration voltage.

[0101] In the embodiment of the present application, the battery airtightness detection method can detect the airtightness of the end cap wire welding, explosion-proof valve, sealing nail, electrode terminal, etc. of the battery under test.

[0102] In the embodiments of the present application, a specific gas is transported into the accommodation chamber, and the gas in the accommodation chamber is subjected to mass spectrometry detection. The mass spectrometry detection can detect micron-sized leakage holes, so that the battery airtightness detection method can safely and efficiently detect the sealing performance of the battery to be tested, thereby improving the detection accuracy of the battery airtightness detection.

[0103] According to some embodiments of the present application, discharging the specific gas in the accommodation chamber includes: pumping out the gas in the accommodation chamber; injecting nitrogen or compressed air into the accommodation chamber; and pumping out the gas in the accommodation chamber again.

[0104] In the example, in order to better remove the residual or attached specific gas in the chamber, during the process of discharging the specific gas in the accommodation chamber, the gas in the accommodation chamber can be pumped out first, then nitrogen or compressed air is injected into the accommodation chamber, and the gas in the accommodation chamber is pumped out again.

[0105] In the embodiments of the present application, by pumping out the gas in the accommodation chamber, injecting nitrogen or compressed air into the accommodation chamber, and pumping out the gas in the accommodation chamber again, the residual or attached specific gas in the chamber can be better removed, thereby further improving the detection accuracy of the battery airtightness detection.

[0106] According to some embodiments of the present application, transporting a specific gas into the accommodation chamber includes: transporting a specific gas into the accommodation chamber and maintaining the pressure of the accommodation chamber for a preset duration.

[0107] In the example, in order to enable the specific gas to enter the battery interior, the pressure of the accommodation chamber can be maintained for a preset duration when transporting the specific gas into the accommodation chamber. Exemplarily, the pressure maintaining pressure is 100 kilopascals (Kpa) to 500 Kpa, and the pressure maintaining time is 10 seconds (s) to 240 s.

[0108] In the embodiments of the present application, by transporting a specific gas into the accommodation chamber and maintaining the pressure of the accommodation chamber for a preset duration, the specific gas can enter the battery to be tested, thereby improving the accuracy of the battery airtightness detection.

[0109] According to some embodiments of the present application, the battery airtightness detection method further includes: sealing the top surface of the battery to be tested when discharging the specific gas in the accommodation chamber.

[0110] In the example, when discharging the specific gas in the accommodation cavity, the top surface of the battery under test can be shielded by controlling the shielding member, so that the top surface of the battery under test is isolated from the gas environment in the accommodation cavity, thereby forming a protective effect and preventing subsequent influence on the detection accuracy. Specifically, if the top surface of the battery under test is in a leaky state, when the air extraction component extracts the gas in the accommodation cavity, it will also extract the specific gas in the battery under test. During subsequent detection, even if the battery under test leaks, the specific gas cannot be detected, and it is easy to obtain an incorrect detection result. Sealing the top surface of the battery under test can isolate the battery under test from the gas environment in the accommodation cavity, so that when discharging the specific gas in the accommodation cavity, only the gas in the accommodation cavity can be discharged, and the gas in the battery under test cannot be extracted, thereby improving the final detection accuracy.

[0111] In the embodiment of the present application, by sealing the top surface of the battery under test when discharging the specific gas in the accommodation cavity, when discharging the specific gas in the accommodation cavity, the probability of the specific gas in the battery being discharged can be reduced, thereby improving the accuracy of the detection result of the battery airtightness detection device.

[0112] The technical solution of the present application will be described below through some specific embodiments.

[0113] Such as Figures 1 to 4As shown in the figure, the battery airtightness detection device 100 includes a detection box 10, an air extraction component 11, a first detection component 12, a gas transmission component 13, a second detection component 14, a shielding component 15, a driving component 16, a gas pipeline, and a pressure detection component 30. The detection box 10 has a receiving cavity for placing the battery under test 20, where the number of batteries under test 20 is multiple. The air extraction component 11 is connected to the detection box 10 and is used to extract the gas in the receiving cavity. The first detection component 12 is connected to the detection box 10 and is used to detect the content of volatile organic compounds in the gas in the receiving cavity before detecting the airtightness of the battery under test 20. The gas transmission component 13 is connected to the detection box 10 and is used to transport a specific gas into the receiving cavity. The second detection component 14 is connected to the detection box 10 and is used to perform mass spectrometry detection on the gas in the receiving cavity. The shielding component 15 is located in the receiving cavity and is floatingly arranged above the battery under test 20. The shielding component 15 is used to shield the top surface of the battery under test 20. The side of the shielding component 15 facing the top surface of the battery under test 20 matches the shape of the top surface of the battery under test 20, so that the shielding component 15 is in sealed contact with the top surface of the battery under test 20. The driving component 16 is connected to the shielding component 15 and at least partially extends out of the detection box 10 to drive the shielding component 15 to approach or move away from the top surface of the battery under test 20. The gas pipeline includes a main pipeline 17 communicating with the receiving cavity and a plurality of branch pipelines 18 communicating with the main pipeline 17. Each branch pipeline 18 is respectively connected to different components, and valves 19 are respectively arranged on each branch pipeline 18. The pressure detection component 30 is arranged on the main pipeline 17 and is used to detect the pressure in the receiving cavity.

[0114] Figure 6 The flowchart of the battery airtightness detection method according to some embodiments of the present application Figure 2 , as Figure 6 shown, the battery airtightness detection method includes the following steps:

[0115] Step S610: Battery feeding, cavity closing: Place the battery under test in the receiving cavity of the detection box, and execute step S620.

[0116] Step S620: Evacuate the cavity and synchronously detect VOCs: Extract the gas in the receiving cavity and detect the content of volatile organic compounds in the gas in the receiving cavity. If the content of volatile organic compounds is less than the preset threshold, execute step S630; if the content of volatile organic compounds is greater than the preset threshold, execute step S680.

[0117] Step S630: Inject tracer gas into the cavity and maintain pressure for a certain time: Transport a specific gas into the receiving cavity and maintain the pressure in the receiving cavity for a preset duration, and execute step S640.

[0118] Step S640: Rubber sleeve expands and contracts to press down and cover the battery end face: Seal the top surface of the battery under test, and execute step S650.

[0119] Step S650: Evacuate and remove the residual tracer gas in the cavity: Pump out the gas in the accommodation cavity, inject nitrogen or compressed air into the accommodation cavity, pump out the gas in the accommodation cavity again, and execute Step S660.

[0120] Step S660: Retract the rubber sleeve and perform mass spectrometry detection: Perform mass spectrometry detection on the gas in the accommodation cavity. If the detection result indicates that the battery under test has no leakage, execute Step S670; if the detection result indicates that the battery under test has leakage, execute Step S680.

[0121] Step S670: Unload the material and complete the detection.

[0122] Step S680: Unload the material and re-detect: Re-detect the airtightness of the battery under test.

[0123] Finally, it should be noted that: The above embodiments are only used to illustrate the technical solutions of the present application, and are not intended to limit them; Although the present application has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: They can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; And these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be covered by the scope of the claims and the description of the present application. In particular, as long as there is no structural conflict, the technical features mentioned in each embodiment can be combined in any way. The present application is not limited to the specific embodiments disclosed in the text, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A battery airtightness detection device (100), characterized in that, Comprising: A detection box (10) having a receiving cavity for placing a battery under test (20); An air extraction assembly (11) connected to the detection box (10) for extracting the gas in the receiving cavity; A first detection assembly (12) connected to the detection box (10) for detecting the content of volatile organic compounds in the gas in the receiving cavity before performing an airtightness detection on the top surface of the battery under test (20) to determine the electrolyte crystallization and pore blockage condition of the battery under test (20); A gas transmission assembly (13) connected to the detection box (10) for delivering a specific gas into the receiving cavity; A shielding member (15) located in the receiving cavity and floatingly arranged above the battery under test (20), the shielding member (15) being used to shield and seal the top surface of the battery under test (20) before the air extraction assembly (11) extracts the specific gas in the receiving cavity; A second detection assembly (14) connected to the detection box (10) for performing mass spectrometry detection on the gas in the receiving cavity after the shielding member (15) separates from the top surface; 2. The battery airtightness detection device (100) according to claim 1, wherein, One side of the shielding member (15) facing the top surface of the battery under test (20) matches the shape of the top surface of the battery under test (20) so that the shielding member (15) is in sealing contact with the top surface of the battery under test (20); 3. The battery airtightness detection device (100) according to claim 1, characterized in that, The device further includes a driving assembly (16) connected to the shielding member (15) and at least partially extending out of the detection box (10) to drive the shielding member (15) to approach or move away from the top surface of the battery under test (20); 4. The battery airtightness detection device (100) according to any one of claims 1 to 3, characterized in that, The device further includes a gas pipeline, the gas pipeline including a main pipeline (17) communicating with the receiving cavity and a plurality of branch pipelines (18) communicating with the main pipeline (17), and each of the branch pipelines (18) is respectively communicated with different components; 5. The battery airtightness detection device (100) according to claim 4, wherein, Valves (19) are respectively provided on each of the branch pipelines (18); 6. The battery airtightness detection device (100) according to claim 4, characterized in that, The device further includes a pressure detection member (30) provided on the main pipeline (17) for detecting the pressure in the receiving cavity; 7. The battery airtightness detection device (100) according to any one of claims 1 to 3, characterized in that, The number of the batteries under test (20) is multiple; 8. A method for detecting the airtightness of a battery, characterized in that, Comprising: Placing a battery under test in the receiving cavity of a detection box; Extracting the gas in the receiving cavity; Before performing an airtightness detection on the top surface of the battery under test, detecting the content of volatile organic compounds in the gas in the receiving cavity to determine the electrolyte crystallization and pore blockage condition of the battery under test; In response to the content of the volatile organic compounds being less than a preset threshold, delivering a specific gas into the receiving cavity; Controlling the shielding member to seal the top surface of the battery under test; Discharging the specific gas in the receiving cavity; Controlling the shielding member to separate from the top surface; Performing mass spectrometry detection on the gas in the receiving cavity; 9. The battery airtightness detection method according to claim 8, characterized in that, The discharging the specific gas in the receiving cavity includes: Extracting the gas in the receiving cavity; Injecting nitrogen or compressed air into the receiving cavity; Extracting the gas in the receiving cavity again; 10. The battery airtightness detection method according to claim 8, characterized in that, The delivering a specific gas into the receiving cavity includes: Transport a specific gas into the accommodation cavity and maintain the pressure in the accommodation cavity for a preset duration.

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