Expanding testing device and expanding testing method

Abstract

The present application relates to the technical field of battery, and particularly relates to an expansion testing device and an expansion testing method. The expansion testing device comprises an environment box and a testing part. The environment box is internally provided with a testing cavity. The testing cavity is communicated with a vacuum pump. The testing part is arranged in the testing cavity. The testing part comprises a support assembly, a clamping assembly, an adjusting assembly and a detection assembly. The support assembly comprises a bottom plate. The clamping assembly comprises an end plate. The end plate is arranged in a spaced manner with the bottom plate. A placement position is formed between the end plate and the bottom plate. The placement position can place a to-be-tested battery cell. The end plate is slidably connected with the support assembly. A driving piece is in transmission connection with the end plate. The detection assembly comprises a displacement sensor and a pressure sensor. The displacement sensor is connected with the end plate. The pressure sensor is connected with the end plate. The testing cavity in the environment box can simulate various environmental conditions that the battery cell may encounter in actual use. The testing part allows the expansion testing device to simultaneously test the expansion displacement and the expansion force of the to-be-tested battery cell, and provides a comprehensive expansion characteristic evaluation mode.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to an expansion testing device and an expansion testing method. BACKGROUND

[0002] In the application field of stratospheric airships, the airships can stay in the stratosphere height (≥18km) for a long time, and are powered by a circulating energy system composed of a solar cell system and an energy storage battery system to realize day and night cycle flight. However, due to the inability to charge the energy storage battery system at night and the limited power, the night wind resistance flight ability and load capacity of the airship will be affected by the working capacity of the energy storage battery system. In order to improve the specific energy of the energy storage battery system, using soft pack lithium battery cells with higher specific energy has become an effective solution.

[0003] However, when the stratospheric airship flies in a long-term low-pressure environment (air pressure is about 5-7kpa), the soft pack lithium battery will swell due to the low air pressure, and this swelling will cause the capacity and performance of the battery to decay, so that it cannot exert its actual capacity under normal pressure. Although it can be strengthened and fastened by external restraint structure, the difference in characteristics of different batteries and the unknown nature of the swelling characteristics increase the difficulty of structural design, and are not conducive to the selection of battery cells. SUMMARY

[0004] The purpose of the present application is to at least solve the problem of how to accurately evaluate the swelling characteristics of the battery under low air pressure conditions. The purpose is achieved by the following technical solutions:

[0005] A first aspect of the present application provides an expansion testing device for testing the swelling characteristics of a battery cell to be tested, comprising an environment box and a testing part, wherein the environment box is provided with a testing cavity, the testing cavity is communicated with a vacuum pump, and the testing part is arranged in the testing cavity, and the testing part comprises:

[0006] A support assembly is connected to the inner wall of the testing cavity, and the support assembly comprises a bottom plate;

[0007] A clamping assembly is provided, which comprises an end plate, the end plate is arranged in a spaced manner with the bottom plate, and a placement position is formed between the end plate and the bottom plate, the placement position is used for placing the battery cell to be tested, and the end plate is slidably connected to the support assembly in the direction from the end plate to the bottom plate;

[0008] An adjusting assembly is provided, which comprises a driving member, the driving member is in transmission connection with the end plate, and the driving member drives the end plate to slide;

[0009] A detection assembly comprising a displacement sensor connected to the end plate for testing the expansion displacement and a pressure sensor connected to the end plate for testing the expansion force.

[0010] The expansion testing device according to the present application, firstly, the test cavity in the environmental box can simulate various environmental conditions that the battery cell may encounter in actual use, such as low air pressure state. This is crucial for the reliability and performance testing of battery cells in applications such as stratospheric airships. Secondly, the test part allows the expansion testing device to simultaneously test the expansion displacement and expansion force of the battery cell under test, providing a comprehensive evaluation method for the expansion characteristics, the displacement sensor is directly connected to the end plate, and the displacement data is recorded in real time as the end plate slides, the pressure sensor is also connected to the end plate, which accurately measures the pressure generated by the expansion of the battery cell, allowing the operator to have a comprehensive understanding of the physical response of the battery cell under a certain environmental pressure. The slidable arrangement of the end plate along the support assembly not only adapts to battery cells of different sizes and shapes, but also provides the necessary space for the expansion of the battery cell, which ensures that the battery cell can be in a natural expansion state without external constraint force during the entire test process, thereby improving the authenticity and accuracy of the test. By collecting and analyzing the data of the expansion displacement and the expansion force, the performance of different battery cells under low air pressure conditions can be better understood, thereby providing a scientific basis for the selection of battery cells and the structural design of battery packs.

[0011] In addition, the expansion testing device according to the present application can also have the following additional technical features:

[0012] In some embodiments of the present application, the test part further comprises a guide mechanism comprising a guide plate and at least one guide column, the guide plate is connected to the support assembly, the guide plate is provided with a through hole, the guide column is slidably arranged in the through hole, and one end of the guide column is connected to the end plate.

[0013] In some embodiments of the present application, the support assembly comprises a side plate, and the bottom plate and the guide plate are respectively connected to the side plate.

[0014] In some embodiments of the present application, the guide plate is provided with an opening, the adjustment assembly comprises a pressure displacement adjustment plate, the driving member is connected to the pressure displacement adjustment plate, the pressure displacement adjustment plate is slidably connected to the support assembly in the direction from the end plate to the bottom plate and can pass through the opening, and the pressure sensor is respectively connected to the end plate and the pressure displacement adjustment plate.

[0015] In some embodiments of the present application, the displacement sensor is a telescopic displacement sensor, the telescopic displacement sensor is connected to the guide plate, and a test end of the telescopic displacement sensor abuts against the end plate.

[0016] In some embodiments of the present application, the expansion testing device further comprises a control unit, which is electrically connected to the driving member and the detection assembly respectively.

[0017] In some embodiments of the present application, the expansion testing device further comprises a power unit, which is arranged outside the testing cavity, and is used to charge or discharge the battery under test.

[0018] In some embodiments of the present application, the driving member is an electric motor.

[0019] In some embodiments of the present application, the projection of the end plate on the bottom plate is consistent with the shape and area of the bottom plate in the direction from the end plate to the bottom plate.

[0020] The second aspect of the present application provides an expansion testing method, comprising the following steps:

[0021] S1: driving the end plate to conform to the battery under test placed in the placement position and setting the initial position, in which the value of the pressure sensor is zero;

[0022] S2: adjusting the air pressure in the testing cavity;

[0023] S3: obtaining the first expansion force according to the pressure sensor;

[0024] S4: driving the end plate to slide to the position in which the value of the pressure sensor is zero, and obtaining the first expansion displacement according to the displacement sensor;

[0025] S5: driving the end plate to the initial position;

[0026] S6: adjusting the state of charge of the battery, and obtaining the second expansion force according to the pressure sensor;

[0027] S7: driving the end plate to slide again to the position in which the value of the pressure sensor is zero, and obtaining the second expansion displacement according to the displacement sensor;

[0028] S8: repeating steps S5 to S7, and obtaining multiple sets of expansion force and expansion displacement data. BRIEF DESCRIPTION OF DRAWINGS

[0029] Various other advantages and benefits will become apparent to those of ordinary skill in the art upon reading the following detailed description of the preferred embodiments. The accompanying drawings are included to provide a better understanding of the preferred embodiments, and are not to be considered as limiting of the application. Moreover, in the drawings, like reference numerals refer to similar components, and:

[0030] Figure 1A structural diagram of an expansion testing device according to an embodiment of the present application is schematically shown.

[0031] Figure 2 A flowchart of an expansion testing method according to an embodiment of the present application.

[0032] Reference signs are as follows:

[0033] 100, expansion testing device;

[0034] 10, environmental box;

[0035] 20, testing section; 21, bottom plate; 22, end plate; 23, guide plate; 231, guide column; 24, side plate; 25, displacement sensor; 26, pressure sensor; 27, driving member; 28, pressure displacement adjustment plate;

[0036] 30, power supply section; 40, control section;

[0037] 200, battery cell. DETAILED DESCRIPTION

[0038] Example embodiments of the present disclosure will be described more fully hereinafter with reference to the accompanying drawings. While example embodiments of the present disclosure are shown in the drawings, it is understood that the present disclosure can be embodied in various forms and should not be limited by the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and fully convey the scope of the present disclosure to those skilled in the art.

[0039] It is to be understood that the terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. The terms "comprises", "comprising", "includes", "including" and "has" are inclusive and therefore specify the presence of stated features, steps, operations, elements, and / or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and / or groups thereof. The method steps, processes, and operations described herein are not to be construed as necessarily requiring their performance in the particular order in which they are described, unless specifically identified as an order dependent step. It is also to be understood that additional or alternative steps can be employed.

[0040] Although terms such as first, second, third, etc., may be used in this document to describe multiple elements, components, regions, layers, and / or segments, these elements, components, regions, layers, and / or segments should not be limited by these terms. These terms may be used only to distinguish one element, component, region, layer, or segment from another. Unless the context clearly indicates otherwise, terms such as "first," "second," and other numerical terms used herein do not imply order or sequence. Therefore, the first element, component, region, layer, or segment discussed below may be referred to as the second element, component, region, layer, or segment without departing from the teachings of the exemplary embodiments.

[0041] For ease of description, spatial relative terms may be used in the text to describe the relationship of one element or feature relative to another element or feature, as shown in the figure. These relative terms include, for example, "inside," "outside," "middle," "outer," "below," "below," "above," "over," etc. Such spatial relative terms are intended to include different orientations of the device in use or operation, other than those depicted in the figure. For example, if the device in the figure is flipped, an element described as "below other elements or features" or "below other elements or features" would subsequently be oriented "above other elements or features" or "above other elements or features." Therefore, the example term "below" can include both upper and lower orientations.

[0042] like Figure 1 As shown, according to an embodiment of the present invention, an expansion testing device 100 is provided. This expansion testing device 100 is used to test the expansion characteristics of a battery cell 200 under test. The expansion testing device 100 includes an environmental chamber 10 and a testing section 20. The environmental chamber 10 has a testing cavity connected to a vacuum pump. The testing section 20 is located within the testing cavity and includes a support assembly, a clamping assembly, an adjustment assembly, and a detection assembly. The support assembly is connected to the inner wall of the testing cavity and includes a base plate 21. The clamping assembly includes an end plate 22. The end plate 22 is connected to... The base plate 21 is spaced apart, and a placement position is formed between the end plate 22 and the base plate 21. The placement position is used to place the battery cell 200 to be tested. Along the direction from the end plate 22 to the base plate 21, the end plate 22 is slidably connected to the bracket assembly. The adjustment assembly includes a drive member 27, which is connected to the end plate 22 in a transmission manner. The drive member 27 drives the end plate 22 to slide. The detection assembly includes a displacement sensor 25 and a pressure sensor 26. The displacement sensor 25 is connected to the end plate 22 and is used to test the expansion displacement. The pressure sensor 26 is connected to the end plate 22 and is used to test the expansion force.

[0043] According to the inflation testing device 100 of the present application, firstly, the test cavity inside the environmental chamber 10 can simulate various environmental conditions that the battery cell 200 may encounter in actual use, such as low air pressure state. This is crucial for the reliability and performance testing of the battery cell 200 in applications such as stratospheric airships. Secondly, the test unit 20 allows the inflation testing device 100 to simultaneously test the inflation displacement and inflation force of the battery cell 200 under test, providing a comprehensive evaluation of the inflation characteristics. The displacement sensor 25 is directly connected to the end plate 22 and records displacement data in real time as the end plate 22 slides, while the pressure sensor 26 is also connected to the end plate 22 and accurately measures the pressure generated by the inflation of the battery cell 200, allowing the operator to have a comprehensive understanding of the physical response of the battery cell 200 under specific environmental pressure. The slidable arrangement of the end plate 22 along the bracket assembly not only accommodates battery cells 200 of different sizes and shapes, but also provides the necessary space for the battery cell 200 to expand during the test, which ensures that the battery cell 200 can be in a natural inflation state without external constraint during the entire test, thereby improving the authenticity and accuracy of the test. By collecting and analyzing the data of inflation displacement and inflation force, the performance of different battery cells 200 under low air pressure conditions can be better understood, providing a scientific basis for the selection of battery cells 200 and the structural design of battery packs.

[0044] It can be understood that the test cavity can simulate a low air pressure environment. In order to simulate a low air pressure environment, a vacuum pump is usually used in the prior art. The test cavity is a sealed vacuum chamber that can withstand the pressure difference between the external normal air pressure and the internal low air pressure, ensuring stable air pressure during the test and preventing air infiltration. The vacuum pump is the core equipment for achieving a low air pressure environment, which is used to remove air from the test cavity, thereby reducing the internal air pressure.

[0045] It can be understood that the bracket structure includes a side plate 24 and a bottom plate 21, and the bottom plate 21 and the side plate 24 are connected in an L shape, and the side plate 24 is used to install the end plate 22 or the guide mechanism, etc. The bottom plate 21 is designed as the base of the inflation testing device 100 to support the side plate 24 and other components installed thereon. The side plate 24 is fixed perpendicular to the bottom plate 21 to provide vertical support for the structure. The combination of the bottom plate 21 and the side plate 24 forms an L-shaped bracket structure, which provides a solid foundation and vertical support to ensure that the entire inflation testing device 100 remains stable during operation, especially during continuous and long-term testing.

[0046] In some embodiments, the testing unit 20 further comprises a guiding mechanism, which includes a guiding plate 23 connected to the side plate 24 in the bracket assembly and at least one guiding column 231 with a through hole in the guiding plate 23 and slidably disposed in the through hole, and one end of the guiding column 231 is connected to the end plate 22. The guiding plate 23 is connected to the side plate 24 and has a through hole. The guiding plate 23 can ensure the support of the guiding column 231 and allow the smooth sliding of the guiding column 231, thereby ensuring the linear movement of the end plate 22. The at least one guiding column 231 is disposed in the through hole of the guiding plate 23. The guiding column 231 is slidably disposed to ensure that the end plate 22 can smoothly move linearly during the expansion or contraction of the battery cell 200. One end of the guiding column 231 is fixedly connected to the end plate 22, and the other end passes through the through hole of the guiding plate 23, so that the movement direction of the end plate 22 remains consistent and accurate. The end plate 22 is connected to the guiding plate 23 through the guiding column 231, which ensures its accurate movement along the predetermined path during the test to adapt to the expansion and contraction of the battery cell 200. The design of the guiding column 231 and the through hole ensures that the end plate 22 moves along a fixed linear path, which is very critical for accurately measuring the displacement and force of the expansion of the battery cell 200. This structure reduces the deviation and swing in movement, improves the repeatability and reliability of the test.

[0047] Specifically, the guiding structure includes two guiding columns 231, which are symmetrically disposed with the detection assembly as the midpoint. Both guiding columns 231 are mounted on the guiding plate 23 and are slidably disposed through the through hole. One end of each guiding column 231 is connected to the end plate 22 to ensure the accurate movement of the end plate 22 along the predetermined linear path. The detection assembly (including the displacement sensor 25 and the pressure sensor 26) is installed in the center of the end plate 22, and the two guiding columns 231 are symmetrically disposed on both sides thereof. Such a layout helps to maintain the stability of the end plate 22 during the test, while ensuring that the sensors directly contact the battery cell 200 to be tested, thereby providing accurate data. By symmetrically disposing the two guiding columns 231, the end plate 22 is ensured to remain horizontal and symmetrical when moving, which is very critical for accurately measuring the expansion size and force of the battery cell 200 during the test. The symmetry reduces the potential distortion or tilt, improving the accuracy of the measurement. At the same time, the symmetrical movement of the end plate 22 ensures that the contact between the sensors and the battery cell 200 remains consistent, which helps to obtain more accurate expansion displacement and expansion force data, thereby improving the reliability of the test results.

[0048] Specifically, the guide plate 23 is provided with an opening, the adjusting assembly includes a pressure displacement adjusting plate 28, a driving member 27 is connected to the pressure displacement adjusting plate 28, in the direction from the end plate 22 to the bottom plate 21, the pressure displacement adjusting plate 28 is slidably connected to the support assembly and can pass through the opening, and the pressure sensor 26 is respectively connected to the end plate 22 and the pressure displacement adjusting plate 28. The opening on the guide plate 23 allows the pressure displacement adjusting plate 28 to pass through, thereby realizing controllable movement in the direction from the end plate 22 to the bottom plate 21. This opening layout allows the pressure displacement adjusting plate 28 to move freely when adjusting, ensuring smoothness and accuracy of operation. The pressure displacement adjusting plate 28 is designed to slide in the direction from the end plate 22 to the bottom plate 21 and can pass through the opening on the guide plate 23. This design allows the adjusting plate to slide on the guide plate 23 to adjust the relative position between it and the end plate 22 to cope with the expansion or contraction of the battery cell 200 during the test. The pressure sensor 26 is respectively installed on the end plate 22 and the pressure displacement adjusting plate 28. This configuration of the pressure sensor 26 allows the pressure exerted by the battery cell 200 on the end plate 22 and the adjusting plate to be monitored simultaneously from two different positions, thereby providing comprehensive monitoring of the expansion behavior of the battery cell 200. The driving member 27, such as an electric screw or a hydraulic device, is connected to the pressure displacement adjusting plate 28 and is responsible for its sliding along the opening of the guide plate 23. Precise control of the driving member 27 ensures that the pressure displacement adjusting plate 28 can be accurately moved according to the test requirements.

[0049] Specifically, the pressure sensor 26 can be a strain gauge pressure sensor 26, a piezoelectric pressure sensor 26, a capacitive pressure sensor 26, or an optical fiber pressure sensor 26.

[0050] Specifically, the displacement sensor 25 is a telescopic displacement sensor 25, which is connected to the guide plate 23, and the test end of the telescopic displacement sensor 25 abuts against the end plate 22. The telescopic displacement sensor 25 includes a telescopic rod, allowing the sensor to expand or contract as the end plate 22 moves, thereby measuring the change in distance. The telescopic displacement sensor 25 is connected to the guide plate 23 through its fixed end, ensuring the stability of its reference position. The test end abuts against the end plate 22, so when the battery cell 200 expands and pushes the end plate 22 to move, the telescopic part of the sensor expands or contracts accordingly, recording the displacement data in real time. The displacement sensor 25 converts physical displacement into electrical signals, which are sent to the data processing system through the connected data line, allowing the operator to monitor and record the expansion displacement of the battery cell 200 in real time during the test. The telescopic displacement sensor 25 can measure very small displacement changes very accurately, which is particularly important for scientific research and quality control in battery cell 200 expansion tests. Its high sensitivity ensures that even small expansions can be accurately recorded. Since the telescopic displacement sensor 25 can provide real-time feedback, it allows the tester to obtain the expansion data of the battery cell 200 in real time, so that adjustments can be made quickly or the state of the battery cell 200 can be evaluated.

[0051] In some embodiments, the test part 20 does not have a guide mechanism, and the pressure sensor 26 and the displacement sensor 25 are directly arranged on the side plate 24 of the bracket assembly, and the driving part 27 of the adjusting assembly is directly connected to the end plate 22 to control the up and down movement of the end plate 22. The pressure sensor 26 is used to monitor the pressure exerted by the battery cell 200 on the end plate 22 during the test, and its data helps to evaluate the physical strength and expansion characteristics of the battery cell 200. The displacement sensor 25 (telescopic displacement sensor 25 or other types) is responsible for measuring the specific movement distance of the end plate 22, thereby accurately recording the expansion displacement of the battery cell 200.

[0052] In some embodiments, the swelling test apparatus 100 includes a control unit 40 electrically connected to the driving member 27 and the detection assembly, respectively. The control unit 40 contains one or more microprocessors or controllers responsible for receiving, processing, and sending instructions to the swelling test apparatus 100. The control unit 40 also includes a user interface that enables the operator to set test parameters, start / stop the test, and view real-time data and results. The driving member 27 (such as a motorized screw, hydraulic, or pneumatic system) is responsible for the actual movement of the end plate 22 or other mechanical components. The control unit 40 sends instructions to adjust the operation of the driving member 27 to precisely control the position and speed of the end plate 22, accommodating the swelling and shrinking of the battery cell 200. The detection assembly (including the pressure sensor 26 and displacement sensor 25) converts physical changes (such as pressure and displacement) into electrical signals, which are sent back to the control unit 40 for processing. The control unit 40 performs real-time analysis based on these data and can adjust the test parameters or the behavior of the driving member 27 to optimize the testing process. The automation function of the control unit 40 allows precise testing operations with reduced human error, improving the repeatability and reliability of the test. The operator can easily set up test cycles and automatically execute complex test sequences. Additionally, the control unit 40 can process data from the detection assembly in real-time, providing immediate feedback, allowing the operator or the system itself to quickly respond to changes in the behavior of the battery cell 200, which is crucial for collecting parameters during the test.

[0053] In some embodiments, the swelling test apparatus 100 also includes a power supply unit 30 located outside the test chamber, which is used to charge or discharge the battery cell 200 under test. By charging or discharging the battery cell 200, the battery cell 200 has different states of charge, which will produce different swelling characteristics. If the swelling phenomenon increases, it will affect the charge and discharge characteristics of the battery cell 200. The power supply unit 30 is located outside the test chamber to safely and conveniently manage power supply and control. This part includes a power supply controller, a battery management system (BMS), and necessary circuit protection devices. The power supply unit 30 is responsible for charging and discharging the battery cell 200 under test. This can be achieved through programming to adjust the battery cell 200 to a specific state of charge (such as full charge, partial discharge, or fully discharged state). The power supply unit 30 operates through the control unit 40, which can adjust the charging and discharging strategy based on the data collected by the detection assembly to observe the swelling characteristics of the battery cell 200 under different states of charge. By controlling the state of charge of the battery cell 200, the power supply unit 30 allows the test apparatus to evaluate the swelling behavior of the battery cell 200 at different charge levels. This is crucial for understanding the physical and chemical stability of the battery cell 200. By monitoring the swelling characteristics under different states of charge, it is possible to predict potential problems that the battery cell 200 may encounter during long-term use, such as internal structural damage caused by swelling, which helps to improve the design and manufacturing process of the battery cell 200.

[0054] In some embodiments, the drive element 27 is a motor, which is connected to the pressure displacement adjustment plate 28 via a screw. The pressure displacement adjustment plate 28 is connected to the end plate 22 via a pressure sensor 26. The motor, as the main drive element 27, provides power, which is converted into linear motion via the connected screw. The rotation of the motor is converted into precise linear movement of the pressure displacement adjustment plate 28 via the screw, enabling fine-tuning of the position of the end plate 22. The pressure displacement adjustment plate 28 is directly connected to the motor via the screw, and its movement is controlled by the rotational speed and direction of the motor, allowing for fine-tuning to accommodate the measurement needs of the cell 200 expansion. The pressure sensor 26 is installed between the pressure displacement adjustment plate 28 and the end plate 22 to measure the pressure exerted on the pressure displacement adjustment plate 28 by the end plate 22 due to the expansion of the cell 200. This setup allows for precise monitoring of the force changes caused by the expansion of the cell 200, providing crucial data for testing. The operation of the motor is typically managed by an integrated control unit 40, which can adjust the motor's speed and rotational direction and automatically adjust the position of the pressure displacement adjustment plate 28 based on real-time feedback data to optimize test conditions and results. By combining a motor and a screw, the expansion testing device 100 can achieve extremely high displacement control accuracy, which is crucial for studying the behavior of the battery cell 200 under different low air pressures. Precise control of the position of the pressure displacement adjustment plate 28 helps to accurately simulate and measure the expansion characteristics of the battery cell 200.

[0055] In some embodiments, the projected areas of end plate 22 and base plate 21 are identical along the direction from end plate 22 to base plate 21. End plate 22 and base plate 21 are designed to perfectly match in projected area, meaning their contours completely overlap in the vertical direction. This design ensures that the pressure applied during cell expansion is uniformly distributed across the entire surface of cell 200. Maintaining the structural symmetry of end plate 22 and base plate 21 in the expansion testing apparatus 100 helps reduce or avoid errors caused by non-uniform loading during testing, improving the accuracy and repeatability of the test. Because end plate 22 and base plate 21 have identical areas, the pressure experienced by cell 200 during charging or discharging will be uniformly distributed across its surface. This is crucial for accurately measuring the expansion behavior of cell 200 under different states of charge, especially when examining the uniformity of the internal structure of cell 200 in response to pressure.

[0056] like Figure 2 As shown, this embodiment also provides an expansion test method, including the following steps:

[0057] S1: Place the battery under test 200 in the test position, drive the end plate 22 into contact with the battery under test 200 to the initial position, and the pressure sensor 26 value is zero. Place the battery under test 200 in the test position, ensure that the end plate 22 is in contact with the battery 200 and adjust to the initial position. At this time, the pressure sensor 26 should be calibrated to zero, ensuring that the measurement starts from the no-load state.

[0058] S2: Adjust the air pressure in the test cavity, adjust the air pressure in the test cavity to the required test conditions, simulate the actual use environment that the battery 200 may encounter, such as low air pressure environment in high altitude or sealed space.

[0059] S3: Obtain the first expansion force according to the pressure sensor 26, and record the first expansion force generated by the expansion of the battery 200 under the fixed air pressure through the pressure sensor 26.

[0060] S4: Drive the end plate 22 to slide to the position where the value of the pressure sensor 26 is zero, obtain the first expansion displacement according to the displacement sensor 25, adjust the position of the end plate 22 until the pressure sensor 26 shows that the pressure is zero, and at this time use the displacement sensor 25 to record the first expansion displacement of the battery 200.

[0061] S5: Drive the end plate 22 to the initial position, and drive the end plate 22 back to the initial position to prepare for the next test.

[0062] S6: Adjust the state of charge of the battery 200, obtain the second expansion force according to the pressure sensor 26, adjust the state of charge of the battery 200 (such as charging or discharging to a certain amount of electricity), and then record the second expansion force in this state.

[0063] S7: Drive the end plate 22 to slide again to the position where the value of the pressure sensor 26 is zero, obtain the second expansion displacement according to the displacement sensor 25, adjust the end plate 22 again until the value of the pressure sensor 26 is zero, and use the displacement sensor 25 to measure the second expansion displacement.

[0064] S8: Repeat steps S5 to S7 to obtain multiple sets of expansion force and expansion displacement data under different states of charge and air pressure conditions.

[0065] The expansion test method of the present embodiment allows comprehensive evaluation of the performance of the battery 200 under different environmental and operating conditions, including its physical expansion characteristics under different states of charge. The detailed expansion data collected helps to perform more stringent quality control procedures to ensure that the battery 200 product meets safety and performance standards.

[0066] The above merely describes preferred specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any changes or replacements within the technical scope disclosed by the present application, which can be easily thought by those skilled in the art, should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An expansion testing device for testing the expansion characteristics of a battery cell under test, characterized in that, The system includes an environmental chamber and a testing unit. The environmental chamber contains a testing cavity, which is connected to a vacuum pump. The testing unit is located within the testing cavity and includes: A support assembly, the support assembly being connected to the inner wall of the test chamber, the support assembly including a base plate; A clamping assembly includes an end plate, which is spaced apart from a base plate, and a placement position is formed between the end plate and the base plate for placing the battery cell under test. The end plate is slidably connected to the support assembly along the direction from the end plate to the base plate. An adjustment assembly, the adjustment assembly including a driving member, the driving member being throttledly connected to the end plate, the driving member driving the end plate to slide; The detection component includes a displacement sensor and a pressure sensor. The displacement sensor is connected to the end plate and is used to test the expansion displacement, and the pressure sensor is connected to the end plate and is used to test the expansion force. The expansion test method applied to the expansion test device includes the following steps: S1: Drive the end plate to come into contact with the battery cell to be tested placed in the placement position and set it to the initial position. In the initial position, the value of the pressure sensor is zero. S2: Adjust the air pressure inside the test chamber; S3: Obtain the first expansion force based on the pressure sensor; S4: Drive the end plate to slide to the position where the pressure sensor value returns to zero, and obtain the first expansion displacement based on the displacement sensor; S5: Drive the end plate to the initial position; S6: Adjust the state of charge of the battery cell and obtain the second expansion force based on the pressure sensor; S7: Drive the end plate to slide again to the position where the pressure sensor value returns to zero, and obtain the second expansion displacement based on the displacement sensor; S8: Repeat steps S5 to S7 and obtain multiple sets of expansion force and multiple sets of expansion displacement data.

2. The expansion testing device according to claim 1, characterized in that, The testing unit also includes a guiding mechanism, which includes a guide plate and at least one guide post. The guide plate is connected to the support assembly. The guide plate has a through hole, and the guide post is slidably inserted into the through hole. One end of the guide post is connected to the end plate.

3. The expansion testing device according to claim 2, characterized in that, The support assembly includes a side plate, and the base plate and the guide plate are respectively connected to the side plate.

4. The expansion testing device according to claim 2, characterized in that, An opening is provided on the guide plate. The adjustment assembly includes a pressure displacement adjustment plate. The driving component is connected to the pressure displacement adjustment plate. Along the direction from the end plate to the bottom plate, the pressure displacement adjustment plate is slidably connected to the bracket assembly and can pass through the opening. The pressure sensor is connected to the end plate and the pressure displacement adjustment plate respectively.

5. The expansion testing device according to claim 2, characterized in that, The displacement sensor is a telescopic displacement sensor, which is connected to the guide plate, and the test end of the telescopic displacement sensor abuts against the end plate.

6. The expansion testing apparatus according to any one of claims 1 to 5, characterized in that, The expansion testing device also includes a control unit, which is electrically connected to the drive unit and the detection component.

7. The expansion testing apparatus according to any one of claims 1 to 5, characterized in that, The expansion testing device also includes a power supply unit located outside the testing chamber, which is used to charge or discharge the battery cell under test.

8. The expansion testing apparatus according to any one of claims 1 to 5, characterized in that, The driving component is a motor.

9. The expansion testing apparatus according to any one of claims 1 to 5, characterized in that, Along the direction from the end plate to the base plate, the projection of the end plate onto the base plate is consistent with the shape and area of ​​the base plate.

10. A method for testing expansion, characterized in that, Includes the following steps: S1: Drive the end plate to come into contact with the battery cell to be tested placed in the placement position and set it to the initial position. In the initial position, the value of the pressure sensor is zero. S2: Adjust the air pressure inside the test chamber; S3: Obtain the first expansion force based on the pressure sensor; S4: Drive the end plate to slide to the position where the pressure sensor value returns to zero, and obtain the first expansion displacement based on the displacement sensor; S5: Drive the end plate to the initial position; S6: Adjust the state of charge of the battery cell and obtain the second expansion force based on the pressure sensor; S7: Drive the end plate to slide again to the position where the pressure sensor value returns to zero, and obtain the second expansion displacement based on the displacement sensor; S8: Repeat steps S5 to S7 and obtain multiple sets of expansion force and multiple sets of expansion displacement data.

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