Soft package battery cell sealing performance detection method

Abstract

The invention provides a method for detecting the sealing performance of a soft package battery cell. The method for detecting the sealing performance of the soft package battery cell comprises the following steps: vacuumizing the packaged soft package battery cell; filling inert gas into the soft package battery core; sealing the soft package battery cell, and placing the soft package battery cell in the sealing cavity; vacuumizing the sealing cavity, and standing for a preset time; whether inert gas exists in the sealing cavity is detected, and if yes, the air tightness of the soft package battery cell is not qualified; if not, the air tightness of the soft package battery cell is qualified. According to the method for detecting the leakproofness of the soft package battery cell, the leakproofness of the battery cell is effectively and comprehensively detected, the leakproofness of the soft package battery cell can be detected without damaging the soft package battery cell, the overall operation is simple, the safety and the performance stability of the soft package battery cell in the detection process and the later use process are ensured, and the detection efficiency is improved. Therefore, the problems that the detection precision is affected and the battery cell itself is destructed due to the fact that a soft package battery cell air-tight sealing detection method in the prior art cannot perform full detection are solved.

Description

Technical Field

[0001] The present application relates to the technical field of batteries, and in particular to a method for detecting the sealing properties of soft-pack battery cells. Background Art

[0002] As a thin, high-energy-density, and flexible lithium-ion battery packaging form, soft-pack batteries are widely used in consumer electronics, new energy vehicles, and energy storage systems. However, the airtightness of soft-pack batteries is crucial to the performance and safety of batteries. Once a small leak occurs in the battery packaging, it will not only lead to a decline in battery performance, such as capacity loss and increased internal resistance, but also cause safety hazards, such as thermal runaway.

[0003] The detection methods in the prior art mainly include the following:

[0004] Thickness, sol effect and tensile strength of aluminum-plastic film testing: This is the most basic testing method, which determines the airtightness of battery packaging materials by measuring their physical properties. However, this method can only indirectly reflect the quality of packaging, has poor detection effect on tiny airtight defects, and cannot ensure the consistency of all battery cells.

[0005] Destructive testing: This involves placing the battery cells in a simulated usage environment and conditions for testing. Although this testing method can evaluate the airtightness of the battery cells under extreme conditions, its destructive nature means that it can only be used as a sampling test and cannot achieve a full inspection.

[0006] Ultrasonic testing method: Using the principle of ultrasonic transmission and reflection, the integrity of the internal structure of the battery cell and the packaging boundary is detected. However, the cost of ultrasonic testing equipment is high, it cannot achieve full inspection, and it has high technical requirements for operators, making it difficult to apply on a large scale on the production line.

[0007] Temperature cycle test method: By testing the battery cells in high and low temperature environments, the thermal expansion and contraction performance of the packaging material is observed to evaluate its air tightness. This method is also destructive, and the test cycle is long and cannot be fully tested, so it is not suitable for rapid testing on the production line.

[0008] In summary, the prior art method for detecting the airtightness of soft-pack battery cells has the problems of being unable to conduct a full inspection, which affects the detection accuracy and is destructive to the battery cells themselves. Summary of the invention

[0009] The main purpose of the present invention is to provide a method for detecting the sealing of soft-pack battery cells, so as to solve the problems that the airtightness detection method of soft-pack battery cells in the prior art cannot fully detect, which affects the detection accuracy and is destructive to the battery cells themselves.

[0010] In order to achieve the above object, according to one aspect of the present invention, a method for detecting the sealing of a soft-pack battery cell is provided, and the method for detecting the sealing of a soft-pack battery cell comprises the following steps:

[0011] Vacuuming the packaged soft-pack battery cell;

[0012] Filling the interior of the soft-pack battery with an inert gas;

[0013] Sealing the soft-pack battery cell and placing the soft-pack battery cell in the sealed cavity;

[0014] Evacuate the sealed chamber and let it stand for a preset time;

[0015] Check whether there is inert gas inside the sealed cavity. If so, the airtightness of the soft-pack battery cell is unqualified; if not, the airtightness of the soft-pack battery cell is qualified.

[0016] Further, the step of placing the soft-pack battery cell in the sealed cavity includes:

[0017] Forming a plurality of soft-pack battery cells into a battery cell group;

[0018] Place several battery cell groups in the sealed cavity.

[0019] Furthermore, a plurality of soft-pack battery cells are stacked to form a battery cell group; and / or a plurality of battery cell groups are arranged in the sealed cavity at intervals.

[0020] Furthermore, the step of placing the soft-pack battery cell in the sealed cavity also includes: arranging a pressing block of a preset weight on the soft-pack battery cell, and the pressing block applies pressure to the sealed soft-pack battery cell.

[0021] Furthermore, the preset weight is 2 kg.

[0022] Furthermore, the preset time is not less than 4 hours.

[0023] Furthermore, the soft-pack battery cell includes a battery cell body, a shell and an air bag. The air bag and the battery cell body are arranged inside the shell. The air bag is connected to the air bag through a first vacuum generator for vacuuming. The interior of the vacuumed air bag is filled with an inert gas of a preset pressure through an inflation device, and the air bag filled with the inert gas is sealed.

[0024] Further, the airbag is sealed by heat sealing; and / or the interior of the airbag is filled with 0.1 MPa of inert gas.

[0025] Furthermore, in the step of evacuating the sealed cavity, the second vacuum generator is connected to the sealed cavity for evacuation.

[0026] Furthermore, in the step of detecting whether there is an inert gas inside the sealed cavity, an inert gas detector connected to the sealed cavity is used to detect whether there is an inert gas inside the sealed cavity.

[0027] By applying the technical scheme of the present invention, the soft-pack battery cell sealing detection method of the present application adopts the steps of evacuating the soft-pack battery cell, filling it with inert gas, placing it in a sealed cavity, evacuating the sealed cavity and detecting the inert gas inside the sealed cavity, thereby effectively realizing a comprehensive detection of the airtightness of the battery cell. Moreover, the above-mentioned detection method can complete the airtightness detection of the soft-pack battery cell without destroying the soft-pack battery cell. The overall operation is simple, thereby ensuring the safety and performance stability of the soft-pack battery cell during the detection process and during the subsequent use.

[0028] The present application adopts the method of filling the interior of the soft-pack battery cell with inert gas as the detection medium, which can avoid contamination of the interior of the battery cell. At the same time, by performing inert gas detection on the sealed cavity in the vacuum environment, tiny gas leaks can be accurately detected, thereby improving the accuracy and reliability of the detection. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0030] Figure 1 A flowchart of a method for detecting the sealing performance of a soft-pack battery cell according to the present invention is shown;

[0031] Figure 2 A structural schematic diagram of the detection of the soft-pack battery cell of the present invention is shown.

[0032] The above drawings include the following reference numerals:

[0033] 10. Soft-pack battery cell; 20. Press block; 30. Vacuum box; 310. Sealed cavity; 40. First vacuum generator; 50. Second vacuum generator; 60. Inert gas detector. DETAILED DESCRIPTION

[0034] It should be noted that, in the absence of conflict, the embodiments and features in the embodiments of the present application can be combined with each other. The present invention will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0035] It should be noted that, unless otherwise specified, all technical and scientific terms used in this application have the same meanings as commonly understood by ordinary technicians in the technical field to which this application belongs.

[0036] In the present invention, unless otherwise specified, the directional words used, such as "up, down, top, bottom", usually refer to the directions shown in the drawings, or to the components themselves in the vertical, perpendicular or gravity directions; similarly, for ease of understanding and description, "inside and outside" refer to the inside and outside relative to the outline of each component itself, but the above-mentioned directional words are not used to limit the present invention.

[0037] In order to solve the problems in the prior art of air tightness detection methods for soft-pack battery cells that they cannot fully detect, affecting the detection accuracy and are destructive to the battery cells themselves, the present application provides a method for detecting airtightness of soft-pack battery cells, which achieves a comprehensive detection of the soft-pack battery cell 10 without destroying the structure of the soft-pack battery cell 10.

[0038] Among them, the present application performs airtightness detection on the soft-pack battery cell 10 after packaging, that is, the detection object of the present application is the soft-pack battery cell 10 that has been packaged.

[0039] In this embodiment, the soft-pack battery cell sealing detection method of the present application mainly utilizes the air bag inside the soft-pack battery cell 10, which is a part of the soft-pack battery cell 10. The present application utilizes the structure of the soft-pack battery cell 10 itself to complete the entire set of sealing detection methods, and realizes the sealing detection of the soft-pack battery cell 10, without the need to use tools such as battery cell puncture or battery cell destruction, and the overall operation is simple.

[0040] like Figure 1 As shown, the method for detecting the sealing of a soft-pack battery cell includes the following steps:

[0041] Evacuate the packaged soft-pack battery cell 10;

[0042] Filling the interior of the soft-pack battery core 10 with an inert gas;

[0043] Sealing the soft-package battery cell 10 and placing the soft-package battery cell 10 in the sealed cavity 310;

[0044] The sealed cavity 310 is evacuated and left to stand for a preset time;

[0045] It is detected whether there is inert gas inside the sealed cavity 310. If so, the airtightness of the soft-pack battery cell 10 is unqualified; if not, the airtightness of the soft-pack battery cell 10 is qualified.

[0046] Among them, by evacuating the soft-pack battery cell 10 to form a preset vacuum degree inside the soft-pack battery cell 10, the air inside the battery cell can be effectively removed, providing a clean environment for subsequent inert gas injection, thereby improving the accuracy of detection.

[0047] In this embodiment, the preset vacuum degree is -80 kPa. This vacuum degree can ensure that the gas inside the battery cell is fully discharged, creating conditions for the injection of inert gas. In the manufacture of high energy density soft-pack battery cells 10, using this vacuum degree can more effectively detect possible tiny leaks, which is conducive to improving the detection accuracy and the effect of comprehensive detection of the soft-pack battery cells 10.

[0048] Specifically, the soft-pack battery cell sealing detection method of the present application adopts the steps of evacuating the soft-pack battery cell 10, filling it with inert gas, placing it in the sealed cavity 310, evacuating the sealed cavity 310 and detecting the inert gas inside the sealed cavity 310, so as to effectively realize a comprehensive detection of the airtightness of the battery cell. Moreover, the above-mentioned detection method can complete the airtightness detection of the soft-pack battery cell 10 without destroying the soft-pack battery cell 10. The overall operation is simple, thereby ensuring the safety and performance stability of the soft-pack battery cell 10 during the detection process and during the subsequent use.

[0049] In this embodiment, the vacuum box 30 is used to provide a sealed chamber 310 .

[0050] The present application adopts the method of filling the interior of the soft-pack battery cell 10 with inert gas as the detection medium, which can avoid contamination of the interior of the battery cell. At the same time, by performing inert gas detection on the sealed cavity 310 in a vacuum environment, tiny gas leaks can be accurately detected, thereby improving the comprehensiveness and accuracy of the detection.

[0051] Among them, the inert gas is helium or nitrogen, etc. It can be understood that helium and nitrogen are ideal choices for detecting the airtightness of the soft-pack battery cell 10 due to their small molecules, difficulty in reacting with other substances and low cost.

[0052] In this embodiment, the inert gas is introduced at a pressure of 0.1 MPa. This pressure level can ensure that the inert gas fully penetrates into every corner of the battery cell, improving the comprehensiveness and accuracy of the detection. The interior of the soft-pack battery cell 10 used in this application is filled with an inert gas at a pressure of 0.1 MPa, and the detection can effectively avoid detection omissions due to insufficient pressure. At the same time, the 0.1 MPa pressure of this application can ensure the uniform distribution of the inert gas inside the battery cell, which is beneficial to improve the efficiency of the detection during the airtightness detection of the soft-pack battery cell 10.

[0053] In this embodiment, the soft-pack battery cell 10 includes a battery cell body, a shell and an air bag, and the air bag and the battery cell body are arranged inside the shell, wherein the shell is an aluminum-plastic film. The step of vacuuming the packaged soft-pack battery cell 10 in this application refers to vacuuming the inside of the air bag.

[0054] Specifically, the first vacuum generator 40 is connected to the air bag for evacuation, and the air bag is evacuated by the first vacuum generator 40, which is conducive to controlling the vacuum degree inside the air bag, so as to adaptively set the vacuum degree according to different sizes and types of soft-pack battery cells 10.

[0055] Among them, the vacuum degree used in this application is -80kpa.

[0056] In this embodiment, the step of filling the inside of the soft-pack battery cell 10 with inert gas refers to filling the inside of the vacuumed air bag with inert gas of a preset pressure through a gas filling device, wherein the gas filling device is used to provide inert gas, and the preset pressure is 0.1 MPa.

[0057] In the present embodiment, the step of sealing the soft-pack battery cell 10 refers to sealing the air bag filled with the inert gas, specifically adopting a heat sealing process to seal the air bag to form the soft-pack battery cell 10 with the inert gas having a preset pressure.

[0058] In this embodiment, the step of placing the soft-pack battery cell 10 in the sealed cavity 310 includes:

[0059] Forming a plurality of soft-pack battery cells 10 into a battery cell group;

[0060] Several battery cell groups are placed in the sealed cavity 310 .

[0061] Among them, the air-tightness test is carried out with the battery group as the test unit, wherein each battery cell group may include one soft-pack battery cell 10 or may include multiple soft-pack battery cells 10. When the battery cell group includes multiple soft-pack battery cells 10, the multiple soft-pack battery cells 10 are stacked, and each soft-pack battery cell 10 in the structure of the multiple soft-pack battery cells 10 is tested inside the accommodating cavity, which is beneficial to improving the accuracy and detection efficiency of the air-tightness test of the soft-pack battery cells 10.

[0062] Specifically, when there are multiple soft-pack battery cells 10 , if there is leakage in the multiple soft-pack battery cells 10 , more inert gas leaks into the sealed cavity 310 , so as to improve the detection accuracy and detection efficiency.

[0063] In this embodiment, the number of soft-pack battery cells 10 may be 8, 10, 12, etc.

[0064] In this embodiment, one or more battery cell groups may be provided. When multiple battery cell groups are provided, the multiple battery cell groups are arranged inside the sealed cavity 310 in an interval-arranged structure, which not only makes full use of the space, but also avoids mutual influence between the battery cells, ensures the accuracy of the test results, and is suitable for the detection of soft-pack battery cells 10 of various sizes and shapes. By reasonably arranging the battery cell groups, the space of the detection equipment can be maximized, while reducing electromagnetic interference and physical collisions between the battery cells, ensuring that each battery cell can be independently and accurately detected. This layout method is particularly suitable for mixed detection of multi-model and multi-size battery cells, providing battery manufacturers with a flexible and efficient detection solution.

[0065] In this embodiment, the step of placing the soft-pack battery cell 10 in the sealed cavity 310 also includes: arranging a pressure block 20 of a preset weight on the soft-pack battery cell 10, and the pressure block 20 applies pressure to the sealed soft-pack battery cell 10. By applying pressure, the force condition of the soft-pack battery cell 10 in actual use can be simulated to ensure that the battery cell can maintain good sealing under various conditions, which is suitable for battery cell testing that needs to withstand a certain mechanical pressure. And by applying pressure to the soft-pack battery cell 10, pressure is applied to the air bag, which is conducive to improving the efficiency of airtightness testing.

[0066] The preset weight is 2kg, which can simulate the pressure in actual use without causing excessive damage to the battery cell.

[0067] The pressing block 20 is made of metal material, and the pressing block 20 can be a weight made of metal material.

[0068] In this embodiment, the preset standing time is not less than 4 hours, specifically 4-8 hours. Long-term standing can fully detect the air tightness of the battery cell at different time points, ensure the stability of the battery cell in long-term use, and is suitable for testing batteries that require long-term stable operation. Standing time of more than 4 hours can observe the changes in the air tightness of the battery cell in different time periods, which is crucial for evaluating the long-term safety and stability of the battery cell.

[0069] In this embodiment, if Figure 2 As shown, in the step of evacuating the sealed chamber 310 , the second vacuum generator 50 is connected to the sealed chamber 310 for evacuation.

[0070] Specifically, the second vacuum generator 50 can be used to fully evacuate sealed cavities 310 of different sizes. This independent vacuum design avoids the air pressure interference between the soft-pack battery cell 10 and the sealed cavity 310, ensures the accuracy of the test results, and is suitable for soft-pack battery cells 10 that require high-precision testing. The second vacuum generator 50 evacuates the sealed cavity 310, which can eliminate the influence of the air pressure inside the soft-pack battery cell 10 on the sealed cavity 310, ensuring the independence and accuracy of the test process.

[0071] In this embodiment, Figure 2 As shown, in the step of detecting whether there is an inert gas inside the sealed cavity 310, the inert gas detector 60 connected to the sealed cavity 310 detects whether there is an inert gas inside the sealed cavity 310, so that the gas changes in the sealed cavity 310 are monitored in real time through the inert gas detector 60, thereby improving the sensitivity and efficiency of the detection, and being able to quickly respond and accurately detect tiny gas leaks. The inert gas detector 60 may be a sensor, such as a nitrogen sensor or a helium sensor; the inert gas detector 60 may also be a helium mass spectrometer, which has extremely high sensitivity and accuracy, and is able to detect extremely small amounts of helium leaks, and is suitable for detecting soft-pack batteries 10 with extremely high requirements for airtightness.

[0072] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0073] The soft-pack battery cell sealing detection method of the present application adopts the steps of evacuating the soft-pack battery cell 10, filling it with inert gas, placing it in the sealed cavity 310, evacuating the sealed cavity 310 and detecting the inert gas inside the sealed cavity 310, so as to effectively realize a comprehensive detection of the airtightness of the battery cell. Moreover, the above-mentioned detection method can complete the airtightness detection of the soft-pack battery cell 10 without destroying the soft-pack battery cell 10. The overall operation is simple, thereby ensuring the safety and performance stability of the soft-pack battery cell 10 during the detection process and the subsequent use process.

[0074] The present application adopts the method of filling the interior of the soft-pack battery cell 10 with an inert gas as the detection medium, which can avoid contamination of the interior of the battery cell. At the same time, by performing inert gas detection on the sealed cavity 310 in a vacuum environment, tiny gas leaks can be accurately detected, thereby improving the accuracy and reliability of the detection.

[0075] The soft-pack battery cell sealing detection method of the present application is applied in the production process of the soft-pack battery cell 10, which can significantly improve the production efficiency and yield rate of the battery cell, reduce the production cost, and provide strong technical support for the widespread application of the soft-pack battery cell 10.

[0076] Obviously, the above-described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work should fall within the scope of protection of the present invention.

[0077] It should be noted that the terms used herein are only for describing specific embodiments and are not intended to limit the exemplary embodiments according to the present application. As used herein, unless the context clearly indicates otherwise, the singular form is also intended to include the plural form. In addition, it should be understood that when the terms "comprise" and / or "include" are used in this specification, it indicates the presence of features, steps, operations, devices, components and / or combinations thereof.

[0078] It should be noted that the terms "first", "second", etc. in the specification and claims of the present application and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the numbers used in this way can be interchanged where appropriate, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein.

[0079] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A method for detecting the sealing performance of a soft-pack battery cell, characterized in that: The following steps are involved: Evacuating the packaged soft-package battery cell (10); Filling the interior of the soft-pack battery core (10) with an inert gas; Sealing the soft-package battery core (10), and placing the soft-package battery core (10) in a sealed cavity (310); The sealed cavity (310) is evacuated and left to stand for a preset time; Detecting whether the inert gas exists inside the sealed cavity (310); if so, the airtightness of the soft-pack battery cell (10) is unqualified; if not, the airtightness of the soft-pack battery cell (10) is qualified.

2. The method for detecting the sealing performance of a soft-pack battery cell according to claim 1, characterized in that: The step of placing the soft-package battery core (10) in the sealed cavity (310) includes: Forming a plurality of the soft-packaged battery cells (10) into a battery cell group; A plurality of the battery cell groups are placed in the sealed cavity (310).

3. The method for detecting the sealing performance of a soft-pack battery cell according to claim 2, characterized in that: A plurality of the soft-packaged battery cells (10) are stacked to form a battery cell group; and / or A plurality of the battery cell groups are arranged at intervals in the sealed cavity (310).

4. The method for detecting the sealing performance of a soft-pack battery cell according to claim 1, characterized in that: The step of placing the soft-package battery core (10) in the sealed cavity (310) also includes: A pressing block (20) of a preset weight is arranged on the soft-package battery core (10), and the pressing block (20) applies pressure to the sealed soft-package battery core (10).

5. The method for detecting the sealing performance of a soft-pack battery cell according to claim 4, characterized in that: The preset weight is 2 kg.

6. The method for detecting the sealing performance of a soft-pack battery cell according to claim 1, characterized in that: The preset time is not less than 4 hours.

7. The method for detecting the sealing performance of a soft-pack battery cell according to any one of claims 1 to 6, characterized in that: The soft-package battery cell (10) comprises a battery cell body, a shell and an air bag, wherein the air bag and the battery cell body are arranged inside the shell; Connecting the first vacuum generator (40) to the air bag to perform vacuuming; Filling the inert gas with a preset pressure into the interior of the vacuumed air bag through an inflation device; The air bag filled with the inert gas is sealed.

8. The method for detecting the sealing performance of a soft-pack battery cell according to claim 7, characterized in that: The airbag is sealed by heat sealing; and / or The interior of the air bag is filled with the inert gas at 0.1 MPa.

9. The method for detecting the sealing performance of a soft-pack battery cell according to any one of claims 1 to 6, characterized in that: In the step of evacuating the sealed cavity (310), the second vacuum generator (50) is connected to the sealed cavity (310) to evacuate the cavity.

10. The method for detecting the sealing performance of a soft-pack battery cell according to any one of claims 1 to 6, characterized in that: In the step of detecting whether the inert gas exists inside the sealed cavity (310), an inert gas detector (60) connected to the sealed cavity (310) is used to detect whether the inert gas exists inside the sealed cavity (310).

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