Airtightness testing method, airtightness testing apparatus and battery cell manufacturing system

Abstract

An airtightness testing method, an airtightness testing apparatus (10) and a battery cell manufacturing system (1). The airtightness testing method comprises: providing an initial battery (S100); performing a vacuum treatment on the initial battery, and injecting an inert gas into the initial battery to obtain a pre-inspection battery (S200); placing the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery is greater than the air pressure in the sealed cavity (S300); collecting an inert gas parameter in the sealed cavity (S400); when the inert gas parameter meets a preset parameter, confirming that the pre-inspection battery is an acceptable battery (S500); and moving the pre-inspection battery out of the sealed cavity, and extracting the inert gas in the pre-inspection battery (S600). The airtightness testing method can significantly improve the airtightness testing accuracy.

Description

Airtightness detection method, airtightness detection device and battery monomer manufacturing system

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application No. 202311828025.6, filed on December 27, 2023, entitled “Airtightness Detection Method, Airtightness Detection Device, and Battery Cell Manufacturing System,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application relates to the technical field of battery manufacturing, and in particular to an airtightness detection method, an airtightness detection device, and a battery cell manufacturing system. Background Art

[0004] Batteries are widely used due to their reliable performance, pollution-free operation, and zero memory effect. For example, with increasing attention paid to environmental protection and the growing popularity of new energy vehicles, demand for batteries is expected to surge.

[0005] The airtightness of the battery has an important impact on the performance of the battery. Therefore, how to improve the accuracy of battery airtightness detection is an urgent problem that needs to be solved in this field.

[0006] Summary of the Invention

[0007] The embodiments of the present application provide an airtightness detection method, an airtightness detection device, and a battery cell manufacturing system. The airtightness detection method can significantly improve the accuracy of airtightness detection.

[0008] In the first aspect, an embodiment of the present application proposes an airtightness detection method, which includes: providing an initial battery; vacuum-treating the initial battery, filling the initial battery with an inert gas to obtain a pre-inspection battery; placing the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery is greater than the air pressure in the sealed cavity; collecting the inert gas parameters in the sealed cavity; confirming that the pre-inspection battery is a qualified battery when the inert gas parameters meet preset parameters; moving the pre-inspection battery out of the sealed cavity, and extracting the inert gas in the pre-inspection battery.

[0009] According to the airtightness detection method of the embodiment of the present application, an inert gas is pre-filled into an initial battery as a pre-inspection battery, and then the pre-inspection battery is placed in a sealed cavity, and an air pressure difference is set between the inside of the pre-inspection battery and the sealed cavity, so that when the pre-inspection battery has a defect, the inert gas in the pre-inspection battery tends to diffuse into the sealed cavity, so that a certain concentration of inert gas exists in the sealed cavity; then, by detecting the parameters of the inert gas in the sealed cavity, it is determined whether there is an inert gas leakage, thereby determining whether the pre-inspection battery meets the production requirements; reducing the interference of the process of filling with inert gas on the airtightness detection, and improving the accuracy of the airtightness detection; after collecting the inert gas parameters, the pre-inspection battery is removed from the sealed cavity and the inert gas in the pre-inspection battery is extracted, further reducing the interference of the process of extracting inert gas on the airtightness detection, and further improving the accuracy of the airtightness detection.

[0010] In some embodiments, the step of placing the pre-test battery in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity, includes: placing the pre-test battery in the sealed cavity, wherein the air pressure in the pre-test battery satisfies a first battery air pressure value; and vacuuming the sealed cavity so that the air pressure in the sealed cavity satisfies the first cavity air pressure value, wherein the first cavity air pressure value is less than the first battery air pressure value. Vacuuming the sealed cavity creates a pressure difference between the sealed cavity and the pre-test battery, which facilitates detection of inert gas parameters in the sealed cavity.

[0011] In some embodiments, the first battery pressure is between 100 KPa and 140 KPa.

[0012] In some embodiments, the air pressure in the first cavity is 10 Pa to 100 Pa.

[0013] In some embodiments, after the step of collecting the inert gas parameters in the sealed cavity, the method further includes: confirming that the pre-inspected battery is an abnormal battery when the inert gas parameters do not meet preset parameters.

[0014] In some embodiments, the step of placing a pre-test battery in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity, includes: placing the pre-test battery in the sealed cavity, wherein the number of pre-test batteries is at least two, and the air pressure of each pre-test battery is greater than the air pressure in the sealed cavity. Embodiments of the present application can further improve the efficiency of airtightness testing.

[0015] In some embodiments, after the step of collecting the inert gas parameters in the sealed cavity, the method includes: confirming that at least two pre-inspection batteries are abnormal batteries when the inert gas parameters do not meet preset parameters; moving the at least two pre-inspection batteries out of the sealed cavity respectively, and filling inert gas into each pre-inspection battery respectively; placing each pre-inspection battery in a sealed cavity corresponding to each pre-inspection battery respectively, wherein the air pressure in each pre-inspection battery is greater than the air pressure in the sealed cavity corresponding to each pre-inspection battery; and collecting the inert gas parameters in each sealed cavity respectively.

[0016] Therefore, when the embodiment of the present application detects that the inert gas parameters do not meet the preset parameters, it is determined that there is at least one abnormal battery in the sealed cavity, and all batteries in the sealed cavity are further tested to screen for abnormal batteries, thereby improving the accuracy of airtightness detection.

[0017] In some embodiments, before removing the pre-test battery from the sealed chamber and extracting the inert gas from the pre-test battery, the process further includes injecting a first gas into the sealed chamber to adjust the pressure within the sealed chamber to a second chamber pressure. Optionally, the second chamber pressure is between 90 kPa and 110 kPa.

[0018] Therefore, the steps of filling inert gas into or extracting inert gas from the battery in the embodiment of the present application are all carried out outside the sealed cavity, which can reduce the burden on a single workstation, shorten the time required for a single workstation, improve overall equipment utilization, improve production efficiency, and reduce the process cost of a single battery unit.

[0019] In some embodiments, the step of moving the pre-inspection battery out of the sealed cavity and extracting the inert gas in the pre-inspection battery includes: moving the pre-inspection battery out of the sealed cavity and extracting the inert gas in the pre-inspection battery until the air pressure in the pre-inspection battery meets a second battery air pressure value; filling the pre-inspection battery with a second gas so that the air pressure in the pre-inspection battery meets a third battery air pressure value, wherein the materials of the second gas and the inert gas are different; wherein the second battery air pressure value is 2KPa to 10KPa; and / or the third battery air pressure value is 90KPa to 101KPa.

[0020] In some embodiments, the steps of vacuum-treating an initial battery and filling the initial battery with an inert gas to obtain a pre-test battery include: vacuum-treating the initial battery until the air pressure in the initial battery meets a fourth battery air pressure value, wherein the fourth battery air pressure value is 30 KPa to 80 KPa; and filling the initial battery with an inert gas to obtain a pre-test battery.

[0021] Therefore, in the embodiment of the present application, the vacuum treatment of the initial battery allows the interior of the initial battery to have a certain degree of vacuum, which is conducive to filling the initial battery with inert gas.

[0022] In some embodiments, after providing the initial battery, the process further includes providing a sealing member to the initial battery, wherein in a first state, the sealing member seals the initial battery; in a second state, the interior of the initial battery communicates with external equipment. Providing the sealing member facilitates connecting or disconnecting the interior of the initial battery from external equipment, facilitating vacuuming or gas injection into the initial battery.

[0023] In the second aspect, the embodiment of the present application proposes an airtightness detection device, which includes a battery supply module, a first inflation module, a first moving module, an acquisition module, a confirmation module and a second moving module. The battery supply module is used to provide an initial battery; the first inflation module is used to vacuum-treat the initial battery, and fill the initial battery with inert gas to obtain a pre-inspection battery; the first moving module is used to place the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery is greater than the air pressure in the sealed cavity; the acquisition module is used to collect the inert gas parameters in the sealed cavity; the confirmation module is used to confirm that the pre-inspection battery is a qualified battery when the inert gas parameters meet the preset parameters; the second moving module is used to move the pre-inspection battery out of the sealed cavity and extract the inert gas in the pre-inspection battery.

[0024] In some embodiments, the airtightness detection device further includes a second inflation module, configured to inject a first gas into the sealed cavity to make the air pressure in the sealed cavity equal to the external air pressure.

[0025] In some embodiments, the airtightness detection device further includes a sealing providing module for providing a sealing member to the initial battery, wherein the sealing member seals the initial battery in a first state; and in a second state, the interior of the initial battery is connected to an external device.

[0026] In a third aspect, the present application proposes a battery cell manufacturing system, which includes an airtightness detection device according to any embodiment of the second aspect of the present application. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the drawings without creative work.

[0028] FIG1 is a schematic flow chart of an airtightness detection method provided in one embodiment of the present application;

[0029] FIG2 is a schematic structural diagram of an initial battery provided in one embodiment of the present application;

[0030] FIG3 is an exploded schematic diagram of the initial battery shown in FIG2 ;

[0031] FIG4 is a flow chart of step S300 in the airtightness detection method provided in one embodiment of the present application;

[0032] FIG5 is a flow chart of an airtightness detection method provided in another embodiment of the present application;

[0033] FIG6 is a flow chart of an airtightness detection method provided in yet another embodiment of the present application;

[0034] FIG7 is a flow chart of an airtightness detection method provided in another embodiment of the present application;

[0035] FIG8 is a schematic structural diagram of a first sealing member and an initial battery in one state in one embodiment of the present application;

[0036] FIG9 is a schematic structural diagram of another state of the first sealing member and the initial battery in one embodiment of the present application;

[0037] FIG10 is a partial enlarged schematic diagram of the first sealing member and the initial battery at position I shown in FIG9 ;

[0038] FIG11 is a schematic structural diagram of a third sealing member and an initial battery in one state in one embodiment of the present application;

[0039] FIG12 is a schematic structural diagram of another state of the third sealing member and the initial battery in one embodiment of the present application;

[0040] FIG13 is a partial enlarged schematic diagram of the third sealing member and the initial battery at position II shown in FIG12;

[0041] FIG14 is a schematic structural diagram of an airtightness detection device according to an embodiment of the present application;

[0042] FIG15 is a schematic structural diagram of an airtightness detection device according to another embodiment of the present application;

[0043] FIG16 is a schematic structural diagram of an airtightness detection device according to another embodiment of the present application;

[0044] FIG17 is a schematic structural diagram of a battery cell manufacturing system according to an embodiment of the present application.

[0045] The accompanying drawings are marked as follows: 1. Manufacturing system; 10. Airtightness detection device; 11. Battery supply module; 12. First inflation module; 13. First moving module; 14. Acquisition module; 15. Confirmation module; 16. Second moving module; 17. Second inflation module; 18. Sealing supply module; 2. Initial battery; 21. Electrode assembly; 22. Outer shell assembly; 221. End cover assembly; 2211. Electrode terminal; 222. Shell; 220. Liquid filling port; 3. First sealing member; 31. First sealing portion; 32. First connecting portion; 4. Third sealing member; 5. Connecting member. DETAILED DESCRIPTION

[0046] Below, with appropriate reference to the accompanying drawings, the embodiments of the airtightness detection method, airtightness detection device, and battery cell manufacturing system of the present application are described in detail. However, there may be cases where unnecessary detailed descriptions are omitted. For example, there are cases where detailed descriptions of well-known matters and repeated descriptions of actually the same structures are omitted. This is to avoid the following description from becoming unnecessarily lengthy and to facilitate the understanding of those skilled in the art. In addition, the drawings and the following description are provided for those skilled in the art to fully understand the present application and are not intended to limit the subject matter described in the claims.

[0047] " Range " disclosed in this application is limited in the form of lower limit and upper limit, and given range is limited by selecting a lower limit and an upper limit, and the selected lower limit and upper limit define the boundary of special range. The scope limited in this way can be inclusive or exclusive of end values, and can be arbitrarily combined, that is, any lower limit can form a range with any upper limit combination. For example, if the range of 60 to 120 and 80 to 110 is listed for a particular parameter, it is understood that the range of 60 to 110 and 80 to 120 is also expected. In addition, if the minimum range values ​​1 and 2 are listed, and if the maximum range values ​​3,4 and 5 are listed, then the following ranges can all be expected: 1 to 3, 1 to 4, 1 to 5, 2 to 3, 2 to 4 and 2 to 5. In this application, unless otherwise specified, the numerical range "a to b" represents an abbreviation of any real number combination between a and b, wherein a and b are real numbers. For example, a numerical range of "0 to 5" indicates that all real numbers between "0 and 5" are listed herein, and "0 to 5" is merely an abbreviation for a combination of these values. Furthermore, when a parameter is expressed as an integer ≥ 2, this is equivalent to disclosing that the parameter is, for example, an integer of 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, etc.

[0048] Unless otherwise specified, all embodiments and optional embodiments of the present application can be combined with each other to form a new technical solution.

[0049] Unless otherwise specified, all technical features and optional technical features of this application can be combined with each other to form a new technical solution.

[0050] Unless otherwise specified, all steps S of the present application may be performed sequentially or randomly, preferably sequentially. For example, a method includes steps S(a) and (b), which means that the method may include steps S(a) and (b) performed sequentially, or may include steps S(b) and (a) performed sequentially. For example, a method may further include step S(c), which means that step S(c) may be added to the method in any order, for example, the method may include steps S(a), (b) and (c), or may include steps S(a), (c) and (b), or may include steps S(c), (a) and (b, etc.

[0051] In the description of the embodiments of the present application, the technical terms "center", "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc. indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the embodiments of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation. Therefore, they should not be understood as limiting the embodiments of the present application.

[0052] In addition, the technical terms "first," "second," etc. are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. In the description of the embodiments of the present application, the meaning of "plurality" is more than two, unless otherwise specifically defined.

[0053] In the description of the embodiments of the present application, unless otherwise expressly specified or limited, technical terms such as "installed," "connected," "connected," and "fixed" should be understood in a broad sense. For example, they can refer to fixed connections, detachable connections, or integration; mechanical connections or electrical connections; direct connections or indirect connections through an intermediate medium; and internal connections between two components or interactions between two components. Those skilled in the art can understand the specific meanings of the above terms in the embodiments of the present application based on specific circumstances.

[0054] In the embodiments of the present application, the terms "plurality" and "multiple" refer to two or more.

[0055] In the embodiments of the present application, battery cells may include lithium-ion secondary battery cells, lithium-ion primary battery cells, lithium-sulfur battery cells, sodium-lithium-ion battery cells, sodium-ion battery cells, or magnesium-ion battery cells, etc., and the embodiments of the present application do not limit this. Battery cells may be cylindrical, flat, rectangular, or other shapes, etc., and the embodiments of the present application do not limit this. Battery cells are generally divided into three types based on the packaging method: cylindrical battery cells, prismatic battery cells, and soft-pack battery cells, and the embodiments of the present application do not limit this.

[0056] The battery referred to in the embodiments of this application refers to a single physical module that includes one or more battery cells to provide higher voltage and capacity. For example, the battery referred to in this application may include a battery module or a battery pack. A battery generally includes a casing that encloses one or more battery cells. The casing prevents liquids or other foreign matter from affecting the charging or discharging of the battery cells.

[0057] A battery cell consists of a housing assembly, an electrode assembly, and an electrolyte. The electrode assembly includes a positive electrode sheet, a negative electrode sheet, and a separator. A battery cell primarily operates by allowing metal ions to migrate between the positive and negative electrode sheets through the electrolyte.

[0058] The battery cell manufacturing process includes electrode fabrication, assembly, and post-filling. Because battery cells place high demands on the strength, waterproofing, and insulation of their outer shell components, they must undergo sealing tests (i.e., airtightness tests) during manufacturing.

[0059] In related technologies, the battery cell to be tested is typically placed in a sealed chamber. Both the cell and the chamber are simultaneously evacuated. After evacuation, helium is injected into the cell. A helium detector is connected to the chamber. If there are packaging defects in the cell, a certain concentration of helium will be present in the chamber, which the detector can detect. After the test is complete, the helium is extracted from the cell, and the vacuum in both the cell and the chamber is released to atmospheric pressure. The cell is then removed from the chamber and moved to the next step.

[0060] The above detection method has the risk of over-killing. Over-killing refers to the mistaken detection of battery cells that meet the requirements as battery cells that do not meet the requirements. The reason for over-killing is that if there is helium leakage during the helium filling process of the battery cells, the helium detector cannot identify it, and thus these battery cells are regarded as battery cells that do not meet the requirements, resulting in poor accuracy of airtightness detection.

[0061] In view of the above problems, the embodiment of the present application moves the helium filling and helium extraction processes out of the sealed cavity, reducing the risk of interference with air tightness testing caused by helium leakage and improving the accuracy of air tightness testing.

[0062] The embodiment of the present application proposes an airtightness detection method.

[0063] As shown in Figure 1, the air tightness detection method includes:

[0064] Step S100, providing an initial battery;

[0065] Step S200 , vacuum-treating the initial battery and filling the initial battery with an inert gas to obtain a pre-inspected battery;

[0066] Step S300, placing the pre-inspected battery in a sealed cavity, wherein the air pressure in the pre-inspected battery is greater than the air pressure in the sealed cavity;

[0067] Step S400, collecting parameters of the inert gas in the sealed cavity;

[0068] Step S500, confirming that the pre-inspected battery is a qualified battery when the inert gas parameters meet the preset parameters;

[0069] Step S600: Move the pre-inspected battery out of the sealed cavity and extract the inert gas in the pre-inspected battery.

[0070] According to the airtightness detection method of the embodiment of the present application, an inert gas is pre-filled into an initial battery as a pre-inspection battery, and then the pre-inspection battery is placed in a sealed cavity, and an air pressure difference is set between the inside of the pre-inspection battery and the sealed cavity, so that when the pre-inspection battery has a defect, the inert gas in the pre-inspection battery tends to diffuse into the sealed cavity, so that a certain concentration of inert gas exists in the sealed cavity; then, by detecting the parameters of the inert gas in the sealed cavity, it is determined whether there is an inert gas leakage, thereby determining whether the pre-inspection battery meets the production requirements; reducing the interference of the process of filling with inert gas on the airtightness detection, and improving the accuracy of the airtightness detection; after collecting the inert gas parameters, the pre-inspection battery is removed from the sealed cavity and the inert gas in the pre-inspection battery is extracted, further reducing the interference of the process of extracting inert gas on the airtightness detection, and further improving the accuracy of the airtightness detection.

[0071] [Step S100]

[0072] Initial battery supplied.

[0073] In the embodiments of the present application, the initial battery, the pre-inspection battery, etc. are different states of battery cells. For example, the initial battery is a battery cell sample to be tested for air tightness, and the pre-inspection battery is a battery cell filled with inert gas. Although the states of the initial battery and the pre-inspection battery are different, the mechanical structures of the initial battery and the pre-inspection battery are the same. Taking the initial battery as an example, its mechanical structure is explained.

[0074] As shown in Figures 2 and 3, in some embodiments, the initial battery 2 includes an electrode assembly 21 and a shell assembly 22. The electrode assembly 21 is located in the shell assembly 22. The electrode assembly 21 includes a positive electrode sheet, a negative electrode sheet and an isolation member. The isolation member is located between the positive electrode sheet and the negative electrode sheet to isolate the isolation member.

[0075] The housing assembly 22 of the initial battery 2 includes an end cap assembly 221 and a housing 222. The electrode assembly 21 is positioned within the housing 222. The end cap assembly 221 is connected to the housing 222 to cover the electrode assembly 21. The end cap assembly 221 includes functional components such as an end cap and an electrode terminal 2211 disposed thereon. The electrode terminal 2211 can be used to electrically connect to the electrode assembly 21 for inputting or outputting electrical energy from the battery cell. The end cap can be made of a variety of materials, such as copper, iron, aluminum, stainless steel, aluminum alloy, and plastic, but this embodiment of the present application does not impose any particular limitation. The end cap assembly 221 can be provided with a liquid injection port 220 for connecting the interior of the initial battery 2 to external devices. Optionally, the liquid injection port 220 can be combined with a sealing member to seal the liquid injection port 220, isolating the interior of the initial battery 2 from the external environment and reducing the impact of the external environment on the interior of the initial battery 2. For example, when sealed, the air pressure inside the initial battery 2 is substantially unaffected by the external environment.

[0076] [Step S200]

[0077] The initial battery is vacuum treated and an inert gas is filled into the initial battery to obtain a pre-test battery.

[0078] In order to detect the airtightness of the initial battery, an inert gas is filled into the initial battery in advance. Before filling the inert gas, the gas pressure inside the initial battery is reduced, that is, the initial battery is vacuum treated.

[0079] Specifically, in some implementations, step S200 may include:

[0080] Step S210 : vacuum-treating the initial battery until the air pressure in the initial battery meets a fourth battery air pressure value, wherein the fourth battery air pressure value is 30 KPa to 80 KPa.

[0081] The vacuum treatment of the initial battery creates a certain degree of vacuum inside the initial battery, which facilitates the filling of the initial battery with an inert gas. The pressure inside the initial battery satisfies a fourth battery pressure value, which can be 30 kPa, 40 kPa, 50 kPa, 60 kPa, 70 kPa, 80 kPa, or a range consisting of any two of the aforementioned values.

[0082] Step S220 , filling the initial battery with inert gas to obtain a pre-inspected battery.

[0083] Inert gases can include helium, argon, etc., with helium being an option. These inert gases will have virtually no side reactions with components within the initial battery and are largely unaffected by environmental factors such as temperature and humidity, thus reducing interference with airtightness testing caused by external environmental factors. Helium has a relatively small molecular weight and can pass through relatively small pores. When small pores exist in the initial battery's outer shell assembly, helium molecules can diffuse through these small pores into the sealed cavity, thereby improving the accuracy of airtightness testing.

[0084] Optionally, the air pressure value in the pre-inspected battery can meet a first battery air pressure value, which is between 100 kPa and 140 kPa, and can be selected to be greater than 101 kPa and less than or equal to 140 kPa, presenting a positive pressure state, which is conducive to forming a pressure differential with the sealed cavity. For example, the first battery air pressure value is 100 kPa, 110 kPa, 120 kPa, 130 kPa, 140 kPa, or a range consisting of any two of the above values.

[0085] [Step S300]

[0086] The pre-test battery is placed in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity.

[0087] By setting a pressure differential between the pre-inspected battery and the sealed cavity, the inert gas in the pre-inspected battery is motivated to diffuse into the sealed cavity. If the pre-inspected battery has packaging defects, such as pores in the outer shell component, the inert gas can diffuse into the sealed cavity through the pores. The airtightness of the pre-inspected battery can be determined by measuring the parameters of the inert gas in the sealed cavity. Of course, if the pre-inspected battery has virtually no packaging defects, the inert gas is encapsulated within the pre-inspected battery and is unlikely to leak.

[0088] As shown in FIG4 , in some embodiments, step S300 may include:

[0089] Step S310 : placing a pre-inspected battery in a sealed cavity, wherein the air pressure in the pre-inspected battery satisfies a first battery air pressure value.

[0090] Optionally, the first battery air pressure value is 100KPa to 140KPa, and can be selected to be greater than 101KPa and less than or equal to 140KPa.

[0091] In an embodiment of the present application, at least one pre-inspection battery can be tested simultaneously, such as one, two, three, five, or ten pre-inspection batteries. For example, taking at least two pre-inspection batteries as an example, after filling at least two pre-inspection batteries with helium, the at least two pre-inspection batteries are placed in the same sealed cavity; and the air pressure of each pre-inspection battery is greater than the air pressure in the sealed cavity, so that there is a pressure difference between the inside of each pre-inspection battery and the sealed cavity. When multiple pre-inspection batteries are placed in the sealed cavity at the same time, the efficiency of airtightness testing can be further improved. For example, if the detection finds that the inert gas parameters in the sealed cavity meet the preset parameters, then all pre-inspection batteries in the sealed cavity are qualified batteries.

[0092] Step S320 : vacuum-treating the sealed cavity so that the air pressure in the sealed cavity meets a first cavity air pressure value, which is lower than a first battery air pressure value.

[0093] By extracting the gas in the sealed cavity, a certain vacuum degree is created in the sealed cavity, thereby forming a pressure difference between the sealed cavity and the pre-test battery.

[0094] Optionally, the air pressure value of the first cavity is 10 Pa to 100 Pa. Exemplarily, the air pressure value of the first cavity can be 10 Pa, 20 Pa, 30 Pa, 50 Pa, 60 Pa, 70 Pa, 80 Pa, 100 Pa, or a range consisting of any two of the above values.

[0095] [Step S400]

[0096] Collect inert gas parameters in the sealed cavity. The inert gas parameters can be the mass concentration or volume concentration of the inert gas.

[0097] As shown in Figure 5, after collecting the inert gas parameters in the sealed chamber, it is necessary to determine whether the inert gas parameters meet the preset parameters. There are two judgment results: one is that the preset parameters are met, and the other is that the preset parameters are not met. After collecting the inert gas parameters, the pre-inspection battery needs to be removed from the sealed chamber.

[0098] [Step S500]

[0099] When the inert gas parameters meet the preset parameters, the pre-inspected battery is confirmed to be a qualified battery.

[0100] The preset parameter may be a mass concentration range or a volume concentration range of the inert gas. For example, the preset parameter is that the volume concentration of the inert gas is ≤ 1×10 -5 Of course, the preset parameters can also be other numerical ranges, such as volume concentration ≤ 5×10 -5 When the collected inert gas parameters meet the above ranges, it indicates that there is basically no leakage of inert gas in the pre-inspected battery; it can be judged that the airtightness of the pre-inspected battery is excellent and it is regarded as a qualified battery.

[0101] [Step S401]

[0102] When the inert gas parameters do not meet the preset parameters, the pre-inspected battery is confirmed to be an abnormal battery.

[0103] When the collected inert gas parameters are greater than 1×10 -5 , indicating that there is a certain concentration of inert gas in the sealed cavity, and there is leakage of inert gas in the pre-inspected battery. It can be judged that the airtightness of the pre-inspected battery is poor, and it is regarded as an abnormal battery and distinguished from the qualified battery.

[0104] In some embodiments, when a plurality of pre-test batteries are included in the sealed cavity, the following steps may be further included after step S400:

[0105] Step S410 , confirming that at least two pre-inspected batteries are abnormal batteries when the inert gas parameters do not meet the preset parameters;

[0106] If a sealed chamber contains multiple pre-tested cells and at least one of them has a leak, inert gas will be present in the sealed chamber, causing the collected inert gas parameters to not meet the preset parameters. In this case, it is impossible to determine which of the multiple pre-tested cells has an airtightness issue. Retesting all pre-tested cells is necessary to eliminate any leaking cells.

[0107] Step S420, at least two pre-inspected batteries are respectively moved out of the sealed cavity, and an inert gas is respectively filled into each pre-inspected battery;

[0108] After all pre-inspected batteries in the sealed cavity are removed from the sealed cavity, at least one of the multiple pre-inspected batteries may be leaking, so each pre-inspected battery is re-filled with inert gas to ensure that the air pressure in each pre-inspected battery meets the first battery pressure value. Of course, the multiple pre-inspected batteries can also be re-evacuated, and then the inert gas is re-injected after the vacuuming process to ensure that the air pressure in each pre-inspected battery meets the first battery pressure value.

[0109] Step S430 , placing each pre-inspection battery in a sealed cavity corresponding to each pre-inspection battery, wherein the air pressure in each pre-inspection battery is greater than the air pressure in the sealed cavity corresponding to each pre-inspection battery.

[0110] The pre-inspected batteries are placed in different sealed cavities, with one pre-inspected battery placed in each sealed cavity, and each pre-inspected battery is tested in a targeted manner.

[0111] Step S440 , respectively collecting parameters of the inert gas in each sealed cavity.

[0112] The inert gas parameters of each sealed cavity are collected respectively, and the collected parameters are judged and analyzed respectively. If the inert gas parameters meet the preset parameters, the pre-inspected battery is confirmed to be a qualified battery; if the inert gas parameters do not meet the preset parameters, the pre-inspected battery is confirmed to be an abnormal battery, thereby eliminating the abnormal battery.

[0113] Therefore, when the embodiment of the present application detects that the inert gas parameters do not meet the preset parameters, it is determined that there is at least one abnormal battery in the sealed cavity, and all batteries in the sealed cavity are further tested to screen for abnormal batteries, thereby improving the accuracy of airtightness detection.

[0114] [Step S600]

[0115] Move the pre-inspection battery out of the sealed chamber and extract the inert gas in the pre-inspection battery.

[0116] The sealed cavity is mainly used for inert gas leakage detection. The steps of filling inert gas into the battery or extracting inert gas are all carried out outside the sealed cavity. It can reduce the burden of a single workstation, shorten the time required for a single workstation, improve the overall equipment utilization rate, improve production efficiency, and reduce the process cost of a single battery unit.

[0117] Furthermore, after extracting the inert gas, a second gas is introduced into the pre-test battery. The second gas is made of a different material than the inert gas. The second gas can be air, argon, or the like, with air being the preferred gas. By introducing the second gas into the pre-test battery, the pressure inside the pre-test battery is substantially equal to the external pressure, or slightly lower than the external pressure, resulting in a slightly negative pressure state.

[0118] In some implementations, step S600 may include:

[0119] Step S610, moving the pre-inspected battery out of the sealed cavity, and extracting inert gas from the pre-inspected battery until the air pressure in the pre-inspected battery meets a second battery air pressure value;

[0120] Step S620: Fill the pre-inspection battery with the second gas so that the gas pressure in the pre-inspection battery meets the third battery gas pressure value.

[0121] After extracting the inert gas from the pre-test battery, the pre-test battery has a certain degree of vacuum. For example, the pressure inside the pre-test battery satisfies a second battery pressure value, which is 2 kPa to 10 kPa. When the pre-test battery has the aforementioned pressure value, it is convenient to fill the pre-test battery with the second gas. For example, the second battery pressure value can be 2 Pa, 3 Pa, 5 Pa, 6 Pa, 7 Pa, 8 Pa, 10 Pa, or a range consisting of any two of the aforementioned values.

[0122] After the second gas is filled into the pre-test battery, the pressure inside the pre-test battery increases. The pressure inside the pre-test battery satisfies a third battery pressure value, which is 90 kPa to 101 kPa, and can be 90 kPa to 100 kPa. For example, the third battery pressure value can be 90 kPa, 91 kPa, 92 kPa, 93 kPa, 94 kPa, 95 kPa, 96 kPa, 97 kPa, 98 kPa, 99 kPa, 100 kPa, 101 kPa, or a range consisting of any two of the foregoing values.

[0123] As shown in FIG6 , in some embodiments, before step S600 , the airtightness detection method may further include:

[0124] In step S700, a first gas is injected into the sealed cavity so that the air pressure in the sealed cavity meets a second cavity air pressure value. Optionally, the second cavity air pressure value is 90 kPa to 110 kPa, or optionally 102 kPa to 110 kPa. For example, the second cavity air pressure value can be 90 kPa, 91 kPa, 92 kPa, 93 kPa, 94 kPa, 95 kPa, 96 kPa, 97 kPa, 98 kPa, 99 kPa, 100 kPa, 101 kPa, 102 kPa, 103 kPa, 104 kPa, 105 kPa, 106 kPa, 107 kPa, 108 kPa, 109 kPa, 110 kPa, or a range consisting of any two of the above values.

[0125] Before removing the pre-inspected battery from the airtight cavity, a first gas is injected into the sealed cavity to substantially equalize the air pressure within the sealed cavity with the external air pressure, or even to achieve a slightly positive pressure. The first gas can be air, for example. In the embodiments of this application, the external air pressure can refer to the air pressure of the environment in which the sealed cavity is located.

[0126] As shown in FIG7 , in some embodiments, after step S100, the airtightness detection method may further include:

[0127] Step S800 involves providing a sealing member to the initial battery. In a first state, the sealing member seals the initial battery; in a second state, the initial battery interior communicates with external devices. The sealing member facilitates connecting or disconnecting the initial battery interior from external devices, facilitating vacuuming or gas injection into the initial battery.

[0128] Optionally, the initial battery includes a liquid injection port, which can connect the interior of the initial battery to the external environment and be used to extract gas from the initial battery or inject gas. The initial battery can be sealed with a sealant, for example, by sealing the liquid injection port of the initial battery.

[0129] The seal can be constructed in various forms. The seal can be used to create a primary battery that has a first state and a second state. In the first state, the seal seals the primary battery, isolating the battery's interior from the external environment. In the second state, the battery's interior is connected to external equipment, allowing gas to be extracted or injected.

[0130] The seal can achieve initial connection or disconnection between the internal environment of the battery and the external environment by means of external force. When connected, operations such as vacuuming and gas injection can be achieved. In this case, the seal can be a first seal or a second seal.

[0131] As shown in Figures 8 to 10, for example, the first seal 3 can connect the interior of the initial battery 2 with the external environment when subjected to an external force such as lifting; and disconnect the interior of the initial battery 2 from the external environment when subjected to an external force such as downward pressure or when there is no external force, so that the interior of the initial battery 2 is isolated from the external environment.

[0132] Illustratively, the first sealing member 3 includes a first sealing portion 31 and a first connecting portion 32. The first sealing portion 31 is connected to the first connecting portion 32. The first sealing portion 31 is configured to seal the liquid injection port 220. The first connecting portion 32 is located outside the initial battery 2, and the cross-section of the first connecting portion 32 is larger than the cross-section of the liquid injection port 220. The structure of the initial battery 2 is designed accordingly to match the structure of the first sealing member 3. For example, the liquid injection port 220 can be provided on the end cap, with the first sealing portion 31 disposed within the liquid injection port 220. The liquid injection port 220 can be configured to have a stepwise varying cross-sectional area. For example, the cross-sectional size of the liquid injection port 220 decreases stepwise from the end cap toward the electrode assembly, with the cross-sectional area of ​​the liquid injection port 220 being perpendicular to the direction from the end cap toward the electrode assembly. The structure of the first sealing portion 31 can be adapted to the form of the liquid injection port 220. For example, the first sealing portion 31 can also be configured to have a stepwise varying cross-sectional area.

[0133] In this case, a force F is applied to the first sealing member 3, such as by lifting the first sealing member 3 upward, and the first connecting portion 32 drives the first sealing member 31 to move in a direction away from the electrode assembly. A gap is provided between the first sealing member 31 and the cavity wall of the liquid injection port 220, so that the interior of the initial battery 2 is connected to the external environment, which can be used for processes such as injecting gas or extracting a vacuum. When it is necessary to seal the initial battery 2, a force is applied to the first sealing member 3, such as by pressing the first sealing member 3 downward, so that the first sealing member 31 seals the liquid injection port 220. Of course, when it is necessary to seal the initial battery 2, no force can be applied to the first sealing member 3, so that the first sealing member 3 moves downward due to its own gravity, so that the first sealing member 31 seals the liquid injection port 220.

[0134] For another example, the seal may be a second seal. When the internal and external environments of the initial battery need to be connected, a force may be applied, such as pressing down the second seal. When the initial battery needs to be sealed, a force may be applied, such as lifting the second seal, or the second seal may be achieved through its own elastic deformation capability. The second seal may adopt any sealing structure in the art that can achieve this function, and this application no longer limits the structure of the second seal.

[0135] For another example, the seal can be connected or disconnected with the external component to initially connect the inside of the battery to the external environment. When connected, vacuuming, gas injection, etc. can be performed. In this case, the seal can be a third seal, etc.

[0136] As shown in Figures 11 and 12, the third seal 4 can be an elastic member such as a rubber sealing nail. The third seal 4 has a through hole that can connect the interior and external environment of the initial battery 2. However, since the third seal 4 is an elastic member, when the third seal 4 is set at the liquid injection port 220, the through hole in the third seal 4 may be squeezed and blocked. When it is necessary to connect the interior and external environment of the initial battery 2, the through hole of the third seal 4 can be penetrated by a connecting piece 5. The connecting piece 5 can be a rigid member with a hollow structure inside. The connecting piece 5 can connect the interior and external environment of the initial battery 2. When it is necessary to seal the initial battery 2, the connecting piece 5 is removed, and the through hole is squeezed and blocked by the elastic deformation ability of the third seal 4 itself, so that the interior of the initial battery 2 is isolated from the external environment.

[0137] In the case where the sealing member is a first sealing member or a second sealing member, the airtightness detection method may include the following steps:

[0138] Step S100, providing an initial battery;

[0139] Step S801, providing a sealing member to the initial battery;

[0140] Step S201, applying force to the sealing member to connect the interior of the initial battery with the external vacuum equipment, and vacuum-treating the initial battery; after vacuum-treating the initial battery, applying force to the sealing member to disconnect the interior of the initial battery from the external environment;

[0141] Step S202, applying force to the sealing member to connect the interior of the initial battery to the external vacuum equipment, and filling the initial battery with an inert gas; after filling with the inert gas, applying force to the sealing member to disconnect the interior of the initial battery from the external environment to obtain a pre-tested battery;

[0142] Step S300, placing the pre-inspected battery in a sealed cavity, wherein the air pressure in the pre-inspected battery is greater than the air pressure in the sealed cavity;

[0143] Step S400, collecting parameters of the inert gas in the sealed cavity;

[0144] Step S500, confirming that the pre-inspected battery is a qualified battery when the inert gas parameters meet the preset parameters;

[0145] Step S601, removing the pre-inspected battery from the sealed chamber, applying force to the seal to connect the interior of the initial battery to the external vacuum equipment, extracting the inert gas in the pre-inspected battery, and after extracting and processing the initial battery, applying force to the seal to disconnect the interior of the initial battery from the external environment;

[0146] Step S602 , applying force to the seal to connect the interior of the initial battery to the external vacuum equipment, filling the pre-inspected battery with a second gas, and after filling with the second gas, applying force to the seal to disconnect the interior of the initial battery from the external environment.

[0147] In the case where the sealing member is a third sealing member, the airtightness detection method may include the following steps:

[0148] Step S100, providing an initial battery;

[0149] Step S802, providing a sealing member to the initial battery;

[0150] Step S203, providing a connecting piece to the sealing piece so that the connecting piece connects the interior of the initial battery and the external vacuum equipment, and vacuum-treating the initial battery; after the vacuum-treating the initial battery, removing the connecting piece to disconnect the interior of the initial battery from the external environment;

[0151] Step S204, providing a connecting piece to the sealing piece so that the connecting piece connects the interior of the initial battery with the external vacuum equipment, and filling the initial battery with an inert gas; after filling with the inert gas, removing the connecting piece to disconnect the interior of the initial battery from the external environment to obtain a pre-inspected battery;

[0152] Step S300, placing the pre-inspected battery in a sealed cavity, wherein the air pressure in the pre-inspected battery is greater than the air pressure in the sealed cavity;

[0153] Step S400, collecting parameters of the inert gas in the sealed cavity;

[0154] Step S500, confirming that the pre-inspected battery is a qualified battery when the inert gas parameters meet the preset parameters;

[0155] Step S603, removing the pre-inspected battery from the sealed cavity, providing a connecting piece to the sealing piece so that the connecting piece connects the interior of the initial battery with the external vacuum equipment, extracting the inert gas in the pre-inspected battery, and after the initial battery is processed, removing the connecting piece to disconnect the interior of the initial battery from the external environment;

[0156] Step S604: providing a connecting piece to the sealing piece so that the connecting piece connects the interior of the initial battery and the external vacuum equipment, and filling the pre-inspected battery with a second gas. After filling with the second gas, removing the connecting piece to disconnect the interior of the initial battery from the external environment.

[0157] The embodiments of the present application also provide an airtightness detection device, which can be used to implement the airtightness detection method of any of the above embodiments of the present application.

[0158] As shown in Figure 14, the airtightness detection device 10 includes a battery providing module 11, a first inflation module 12, a first moving module 13, a collection module 14, a confirmation module 15 and a second moving module 16. The battery providing module 11 is used to provide an initial battery; the first inflation module 12 is used to vacuum-treat the initial battery and fill the initial battery with an inert gas to obtain a pre-inspection battery; the first moving module 13 is used to place the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery is greater than the air pressure in the sealed cavity; the collection module 14 is used to collect the inert gas parameters in the sealed cavity; the confirmation module 15 is used to confirm that the pre-inspection battery is a qualified battery when the inert gas parameters meet the preset parameters; the second moving module 16 is used to move the pre-inspection battery out of the sealed cavity and extract the inert gas in the pre-inspection battery.

[0159] Optionally, the confirmation module 15 is further configured to confirm that the pre-inspected battery is an abnormal battery when the inert gas parameter does not meet a preset parameter.

[0160] Optionally, the first moving module 13 is used to place the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery meets a first battery air pressure value; and is used to vacuum-treat the sealed cavity so that the air pressure in the sealed cavity meets a first cavity air pressure value, and the first cavity air pressure value is less than the first battery air pressure value.

[0161] Optionally, the first charging module 12 is used to vacuum-treat the initial battery until the air pressure in the initial battery meets a fourth battery air pressure value; and is used to charge the initial battery with an inert gas to obtain a pre-inspected battery.

[0162] As shown in FIG. 15 , in some embodiments, the airtightness detection device 10 further includes a second inflation module 17 for injecting a first gas into the sealed cavity so that the air pressure in the sealed cavity meets a second cavity air pressure value.

[0163] As shown in FIG16 , in some embodiments, the airtightness detection device 10 further includes a sealing providing module 18 for providing a seal to the initial battery, wherein the seal seals the initial battery in a first state; and in a second state, the interior of the initial battery is connected to external equipment.

[0164] Each of the above modules can adopt equipment well known in the art, and its specific structure will not be described in detail here.

[0165] The embodiments of the present application also provide a battery cell manufacturing system.

[0166] As shown in FIG17 , a battery cell manufacturing system 1 includes an airtightness detection device 10 according to any one of the above-mentioned embodiments of the present application. The airtightness detection device 10 is configured to perform airtightness detection on a battery cell.

[0167] In some embodiments, the manufacturing system 1 may further include a pole piece manufacturing device, which is used to manufacture positive pole pieces, negative pole pieces, etc.

[0168] In some embodiments, the manufacturing system 1 may further include an electrode assembly manufacturing device, which is used to wind or stack the positive electrode sheets, separators, and negative electrode sheets into an electrode assembly.

[0169] In some embodiments, the manufacturing system 1 may further include a shell insertion device, which is used to assemble the electrode assembly into the shell.

[0170] In some embodiments, the manufacturing system 1 may further include a sealing device, which is used to seal the shell.

[0171] In some embodiments, the manufacturing system 1 may further include a liquid injection device for injecting electrolyte into the battery cell.

[0172] In some embodiments, the manufacturing system 1 may further include a formation device, which is used to perform a formation operation on the battery cells to activate active materials in the electrode assembly.

[0173] Of course, the manufacturing system 1 may also include, in addition to the devices listed above, other devices that are well known in the art and are essential for manufacturing battery cells, which will not be described in detail here.

[0174] Although illustrative embodiments have been shown and described, those skilled in the art should understand that the above embodiments should not be construed as limitations on the present application, and that changes, substitutions, and modifications may be made to the embodiments without departing from the spirit, principles, and scope of the present application.

Claims

1. A method for detecting air tightness, comprising: Provide initial battery; vacuum treating the initial battery and filling the initial battery with an inert gas to obtain a pre-test battery; Placing the pre-test battery in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity; collecting parameters of the inert gas in the sealed cavity; Confirming that the pre-inspected battery is a qualified battery when the inert gas parameters meet preset parameters; The pre-test battery is moved out of the sealed cavity, and the inert gas in the pre-test battery is extracted.

2. The airtightness detection method according to claim 1, wherein: The step of placing the pre-test battery in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity, comprises: Placing the pre-inspected battery in a sealed cavity, wherein the air pressure in the pre-inspected battery satisfies a first battery air pressure value; The sealed cavity is vacuum treated so that the air pressure in the sealed cavity meets a first cavity air pressure value, and the first cavity air pressure value is less than the first battery air pressure value.

3. The airtightness detection method according to claim 2, wherein: The first battery air pressure value is 100KPa to 140KPa; and / or the first cavity air pressure value is 10Pa to 100Pa.

4. The airtightness detection method according to any one of claims 1 to 3, after the step of collecting the inert gas parameters in the sealed cavity, further comprising: When the inert gas parameter does not satisfy the preset parameter, the pre-inspected battery is confirmed to be an abnormal battery.

5. The airtightness detection method according to any one of claims 1 to 4, wherein: The step of placing the pre-test battery in a sealed cavity, wherein the air pressure in the pre-test battery is greater than the air pressure in the sealed cavity, comprises: The pre-test battery is placed in a sealed cavity, wherein the number of the pre-test batteries is at least two, and the air pressure of each of the pre-test batteries is greater than the air pressure in the sealed cavity.

6. The airtightness detection method according to claim 5, after the step of collecting the inert gas parameters in the sealed cavity, further comprising: confirming that the at least two pre-inspected batteries are abnormal batteries when the inert gas parameters do not meet the preset parameters; Move at least two of the pre-test batteries out of the sealed cavity respectively, and fill each of the pre-test batteries with an inert gas respectively; Placing each of the pre-inspection batteries in the sealed cavity corresponding to each of the pre-inspection batteries, wherein the air pressure in each of the pre-inspection batteries is greater than the air pressure in the sealed cavity corresponding to each of the pre-inspection batteries; The inert gas parameters in each of the sealed cavities are collected respectively.

7. The airtightness detection method according to any one of claims 1 to 6, before the step of moving the pre-inspected battery out of the sealed cavity and extracting the inert gas in the pre-inspected battery, further comprising: A first gas is injected into the sealed cavity so that the air pressure in the sealed cavity meets the second cavity air pressure value.

8. The airtightness detection method according to any one of claims 1 to 7, wherein: The step of moving the pre-test battery out of the sealed cavity and extracting the inert gas in the pre-test battery includes: The pre-test battery is moved out of the sealed cavity, and the inert gas in the pre-test battery is extracted until the gas pressure in the pre-test battery meets the second battery gas pressure value; Filling the pre-test battery with a second gas so that the gas pressure in the pre-test battery meets a third battery gas pressure value, wherein the second gas and the inert gas are made of different materials; in, The second battery air pressure value is 2KPa to 10KPa; and / or the third battery air pressure value is 90KPa to 101KPa.

9. The airtightness detection method according to any one of claims 1 to 8, wherein: The step of vacuum treating the initial battery and filling the initial battery with an inert gas to obtain a pre-test battery comprises: Vacuum-treating the initial battery until the air pressure in the initial battery meets a fourth battery air pressure value, wherein the fourth battery air pressure value is 30 KPa to 80 KPa; The initial battery is filled with an inert gas to obtain a pre-test battery.

10. The airtightness detection method according to any one of claims 1 to 9, after the step of providing an initial battery, further comprising: A sealing member is provided to the initial battery, wherein the sealing member seals the initial battery in a first state and the interior of the initial battery is connected to an external device in a second state.

11. An airtightness detection device, comprising: A battery supply module, used for providing an initial battery; A first gas filling module, used for vacuum processing the initial battery, filling the initial battery with an inert gas to obtain a pre-test battery; A first moving module, used to place the pre-inspection battery in a sealed cavity, wherein the air pressure in the pre-inspection battery is greater than the air pressure in the sealed cavity; A collection module, used for collecting parameters of the inert gas in the sealed cavity; A confirmation module, used for confirming that the pre-inspected battery is a qualified battery when the inert gas parameter meets the preset parameter; and The second moving module is used to move the pre-inspection battery out of the sealed cavity and extract the inert gas in the pre-inspection battery. 12 . The airtightness detection device according to claim 11 , further comprising a second inflation module, configured to inject a first gas into the sealed cavity so that the air pressure in the sealed cavity satisfies a second cavity air pressure value.

13. The airtightness detection device according to claim 11 or 12, further comprising a sealing providing module for providing a sealing member to the initial battery, wherein: The sealing member seals the initial battery in a first state; In the second state, the interior of the initial battery is in communication with an external device. 14 . A battery cell manufacturing system, comprising the airtightness detection device according to claim 11 .

Images